see thrombophilia.
The diagnosis of certain disorders can be helped by measuring the concentrations of various enzymes in the blood. After a heart attack (myocardial infarction – see HEART, DISEASES OF), raised levels of heart enzymes occur as a result of damage to the cells of the heart muscle. Some inherited diseases such as GALACTOSAEMIA and PHENYLKETONURIA are the result of de?ciencies of certain enzymes.
Enzymes can be a useful part of treatment for some disorders. STREPTOKINASE, for example, is used to treat THROMBOSIS; wound-dressings containing papain from the pawpaw fruit – this contains protein-digesting enzymes – assist in the healing process; and pancreatic enzymes can be of value to patients with malabsorption caused by disorders of the PANCREAS.... enzyme
Ichthyosis vulgaris Common and inherited as a dominant trait. Beginning in early childhood, it is often associated with atopic eczema (see DERMATITIS). The limb ?exures and face are spared.
X-linked ichthyosis is much less common, more severe and appears earlier than ichthyosis vulgaris. The ?sh-like scales are larger and darker and do not spare the ?exures and face.
Ichthyosiform erythroderma Of two types and very rare: in the recessive form, the appearance at birth is of the so-called ‘collodion baby’; in the dominant form the baby is born with universally red, moist and eroded skin with an unpleasant smell. Gradually, over several months, thick scales replace the ERYTHEMA.
Treatment Minor forms are helped by constant use of EMOLLIENTS and moisturising applications. Cream containing UREA can be valuable. The rare erythrodermic patterns in the neonate require skilled intensive care as thermoregulation is disturbed and massive ?uid loss occurs through the skin. Later in childhood, oral RETINOIDS are useful.... ichthyosis
Aneurysms generally arise in the elderly, with men affected more commonly than women. The most common cause is degenerative atheromatous disease, but other rarer causes include trauma, inherited conditions such as MARFAN’S SYNDROME, or acquired conditions such as SYPHILIS or POLYARTERITIS NODOSA. Once formed, the pressure of the circulating blood within the aneurysm causes it to increase in size. At ?rst, there may be no symptoms or signs, but as the aneurysm enlarges it becomes detectable as a swelling which pulsates with each heartbeat. It may also cause pain due to pressure on local nerves or bones. Rupture of the aneurysm may occur at any time, but is much more likely when the aneurysm is large. Rupture is usually a surgical emergency, because the bleeding is arterial and therefore considerable amounts of blood may be lost very rapidly, leading to collapse, shock and even death. Rupture of an aneurysm in the circle of Willis causes subarachnoid haemorrhage, a life-threatening event. Rupture of an aneurysm in the abdominal aorta is also life-threatening.
Treatment Treatment is usually surgical. Once an aneurysm has formed, the tendency is for it to enlarge progressively regardless of any medical therapy. The surgery is often demanding and is therefore usually undertaken only when the aneurysm is large and the risk of rupture is therefore increased. The patient’s general ?tness for surgery is also an important consideration. The surgery usually involves either bypassing or replacing the affected part of the artery using a conduit made either of vein or of a man-made ?bre which has been woven or knitted into a tube. Routine X-ray scanning of the abdominal aorta is a valuable preventive procedure, enabling ‘cold’ surgery to be performed on identi?ed aneurysms.... aneurysm
Cancers are classi?ed according to the type of cell from which they are derived as well as the organ of origin. Hence cancers arising within the bronchi, often collectively referred to as ‘lung cancer’, include both adenocarcinomas, derived from epithelium (surface tissue), and carcinomas from glandular tissue. Sarcomas are cancers of connective tissue, including bone and cartilage. The behaviour of cancers and their response to therapy vary widely depending on this classi?cation as well as on numerous other factors such as how large the cancer is, how fast the cells grow and how well de?ned they are. It is entirely wrong to see cancer as a single disease entity with a universally poor prognosis. For example, fewer than one-half of women in whom breast cancer (see BREASTS, DISEASES OF) is discovered will die from the disease, and 75 per cent of children with lymphoblastic LEUKAEMIA can be cured.
Incidence In most western countries, cancer is the second most important cause of death after heart disease and accounts for 20–25 per cent of all deaths. In the United Kingdom in 2003, more than 154,000 people died of malignant disease. There is wide international variation in the most frequently encountered types of cancer, re?ecting the importance of environmental factors in the development of cancer. In the UK as well as the US, carcinoma of the BRONCHUS is the most common. Since it is usually inoperable at the time of diagnosis, it is even more strikingly the leading cause of cancer deaths. In women, breast cancer was for a long time the most common malignant disease, accounting for a quarter of all cancers, but ?gures for the late 1990s show that lung cancer now heads the incidence list – presumably the consequence of a rising incidence of smoking among young women. Other common sites are as follows: males – colon and rectum, prostate and bladder; females – colon and rectum, uterus, ovary and pancreas.
In 2003, of the more than 154,000 people in the UK who died of cancer, over 33,000 had the disease in their respiratory system, nearly 13,000 in the breast, over 5,800 in the stomach and more than 2,000 in the uterus or cervix, while over 4,000 people had leukaemia. The incidence of cancer varies with age; the older a person is, the more likely it is that he or she will develop the disease. The over-85s have an incidence about nine times greater than those in the 25–44 age group. There are also di?erences in incidence between sexes: for example, more men than women develop lung cancer, though the incidence in women is rising as the effects of smoking work through. The death rate from cancer is falling in people under 75 in the UK, a trend largely determined by the cancers which cause the most deaths: lung, breast, colorectal, stomach and prostate.
Causes In most cases the causes of cancer remain unknown, though a family history of cancer may be relevant. Rapid advances have, however, been made in the past two decades in understanding the di?erences between cancer cells and normal cells at the genetic level. It is now widely accepted that cancer results from acquired changes in the genetic make-up of a particular cell or group of cells which ultimately lead to a failure of the normal mechanisms regulating their growth. It appears that in most cases a cascade of changes is required for cells to behave in a truly malignant fashion; the critical changes affect speci?c key GENES, known as oncogenes, which are involved in growth regulation. (See APOPTOSIS.)
Since small genetic errors occur within cells at all times – most but not all of which are repaired – it follows that some cancers may develop as a result of an accumulation of random changes which cannot be attributed to environmental or other causes. The environmental factors known to cause cancer, such as radiation and chemicals (including tar from tobacco, asbestos, etc.), do so by increasing the overall rate of acquired genetic damage. Certain viral infections can induce speci?c cancers (e.g. HEPATITIS B VIRUS and HEPATOMA, EPSTEIN BARR VIRUS and LYMPHOMA) probably by inducing alterations in speci?c genes. HORMONES may also be a factor in the development of certain cancers such as those of the prostate and breast. Where there is a particular family tendency to certain types of cancer, it now appears that one or more of the critical genetic abnormalities required for development of that cancer may have been inherited. Where environmental factors such as tobacco smoking or asbestos are known to cause cancer, then health education and preventive measures can reduce the incidence of the relevant cancer. Cancer can also affect the white cells in the blood and is called LEUKAEMIA.
Treatment Many cancers can be cured by surgical removal if they are detected early, before there has been spread of signi?cant numbers of tumour cells to distant sites. Important within this group are breast, colon and skin cancer (melanoma). The probability of early detection of certain cancers can be increased by screening programmes in which (ideally) all people at particular risk of development of such cancers are examined at regular intervals. Routine screening for CERVICAL CANCER and breast cancer (see BREASTS, DISEASES OF) is currently practised in the UK. The e?ectiveness of screening people for cancer is, however, controversial. Apart from questions surrounding the reliability of screening tests, they undoubtedly create anxieties among the subjects being screened.
If complete surgical removal of the tumour is not possible because of its location or because spread from the primary site has occurred, an operation may nevertheless be helpful to relieve symptoms (e.g. pain) and to reduce the bulk of the tumour remaining to be dealt with by alternative means such as RADIOTHERAPY or CHEMOTHERAPY. In some cases radiotherapy is preferable to surgery and may be curative, for example, in the management of tumours of the larynx or of the uterine cervix. Certain tumours are highly sensitive to chemotherapy and may be cured by the use of chemotherapeutic drugs alone. These include testicular tumours, LEUKAEMIA, LYMPHOMA and a variety of tumours occurring in childhood. These tend to be rapidly growing tumours composed of primitive cells which are much more vulnerable to the toxic effects of the chemotherapeutic agents than the normal cells within the body.
Unfortunately neither radiotherapy nor currently available chemotherapy provides a curative option for the majority of common cancers if surgical excision is not feasible. New e?ective treatments in these conditions are urgently needed. Nevertheless the rapidly increasing knowledge of cancer biology will almost certainly lead to novel therapeutic approaches – including probably genetic techniques utilising the recent discoveries of oncogenes (genes that can cause cancer). Where cure is not possible, there often remains much that can be done for the cancer-sufferer in terms of control of unpleasant symptoms such as pain. Many of the most important recent advances in cancer care relate to such ‘palliative’ treatment, and include the establishment in the UK of palliative care hospices.
Families and patients can obtain valuable help and advice from Marie Curie Cancer Care, Cancer Relief Macmillan Fund, or the British Association of Cancer United Patients.
www.cancerbacup.org.uk
www.mariecurie.org.uk... cancer
Anticoagulant therapy will also cause a fall in prothrombin levels.... hypoprothrombinaemia
Haemophilia affects approximately 1:4,000 of the UK population but only 1:20,000 is severely affected. Severity of the disease depends upon the percentage, compared with normal, of factor VIII activity present. Less than 1 per cent and there will be spontaneous bleeding into joints and muscles; 1–5 per cent and there will be occasional spontaneous bleeding and severe bleeding after minor injury; 5–25 per cent and there will only be severe bleeding after major injury. Before treatment was available, severe haemophiliacs suffered from acute pain and deformity from bleeds into joints and muscles. Bleeding also occurred into the gut, kidneys and brain, and few survived past adolescence.
Freeze-dried factor VIII may be kept in domestic refrigerators. Haemophiliacs can use it to abort minor bleeds by reconstituting it and injecting it intravenously. More major bleeding or preparation for surgery involves raising factor VIII levels to 30–100 per cent by giving cryoprecipitate.
With treatment, most haemophiliacs lead normal lives, although obviously dangerous or contact sports should be avoided. Before donors of blood were screened for HEPATITIS B and C or for HIV infection (see AIDS/HIV), some individuals with haemophilia receiving factor VIII were unwittingly infected with those diseases. Today’s screening procedures make such infections very unlikely.
There is a National Haemophilia Register and each registered sufferer carries a card with details about his or her condition. Information may also be obtained from NHS haemophilia centres and the Haemophilia Society.... haemophilia
Dominant genes A dominant characteristic is an e?ect which is produced whenever a gene or gene defect is present. If a disease is due to a dominant gene, those affected are heterozygous – that is, they only carry a fault in the gene on one of the pair of chromosomes concerned. A?ected people married to normal individuals transmit the gene directly to one-half of the children, although this is a random event just like tossing a coin. HUNTINGTON’S CHOREA is due to the inheritance of a dominant gene, as is neuro?bromatosis (see VON RECKLINGHAUSEN’S DISEASE) and familial adenomatous POLYPOSIS of the COLON. ACHONDROPLASIA is an example of a disorder in which there is a high frequency of a new dominant mutation, for the majority of affected people have normal parents and siblings. However, the chances of the children of a parent with the condition being affected are one in two, as with any other dominant characteristic. Other diseases inherited as dominant characteristics include spherocytosis, haemorrhagic telangiectasia and adult polycystic kidney disease.
Recessive genes If a disease is due to a recessive gene, those affected must have the faulty gene on both copies of the chromosome pair (i.e. be homozygous). The possession of a single recessive gene does not result in overt disease, and the bearer usually carries this potentially unfavourable gene without knowing it. If that person marries another carrier of the same recessive gene, there is a one-in-four chance that their children will receive the gene in a double dose, and so have the disease. If an individual sufferer from a recessive disease marries an apparently normal person who is a heterozygous carrier of the same gene, one-half of the children will be affected and the other half will be carriers of the disease. The commonest of such recessive conditions in Britain is CYSTIC FIBROSIS, which affects about one child in 2,000. Approximately 5 per cent of the population carry a faulty copy of the gene. Most of the inborn errors of metabolism, such as PHENYLKETONURIA, GALACTOSAEMIA and congenital adrenal hyperplasia (see ADRENOGENITAL SYNDROME), are due to recessive genes.
There are characteristics which may be incompletely recessive – that is, neither completely dominant nor completely recessive – and the heterozygotus person, who bears the gene in a single dose, may have a slight defect whilst the homozygotus, with a double dose of the gene, has a severe illness. The sickle-cell trait is a result of the sickle-cell gene in single dose, and sickle-cell ANAEMIA is the consequence of a double dose.
Sex-linked genes If a condition is sex-linked, affected males are homozygous for the mutated gene as they carry it on their single X chromosome. The X chromosome carries many genes, while the Y chromosome bears few genes, if any, other than those determining masculinity. The genes on the X chromosome of the male are thus not matched by corresponding genes on the Y chromosome, so that there is no chance of the Y chromosome neutralising any recessive trait on the X chromosome. A recessive gene can therefore produce disease, since it will not be suppressed by the normal gene of the homologous chromosome. The same recessive gene on the X chromosome of the female will be suppressed by the normal gene on the other X chromosome. Such sex-linked conditions include HAEMOPHILIA, CHRISTMAS DISEASE, DUCHENNE MUSCULAR
DYSTROPHY (see also MUSCLES, DISORDERS OF – Myopathy) and nephrogenic DIABETES INSIPIDUS.
If the mother of an affected child has another male relative affected, she is a heterozygote carrier; half her sons will have the disease and half her daughters will be carriers. The sister of a haemophiliac thus has a 50 per cent chance of being a carrier. An affected male cannot transmit the gene to his son because the X chromosome of the son must come from the mother; all his daughters, however, will be carriers as the X chromosome for the father must be transmitted to all his daughters. Hence sex-linked recessive characteristics cannot be passed from father to son. Sporadic cases may be the result of a new mutation, in which case the mother is not the carrier and is not likely to have further affected children. It is probable that one-third of haemophiliacs arise as a result of fresh mutations, and these patients will be the ?rst in the families to be affected. Sometimes the carrier of a sex-linked recessive gene can be identi?ed. The sex-linked variety of retinitis pigmentosa (see EYE, DISORDERS OF) can often be detected by ophthalmoscopic examination.
A few rare disorders are due to dominant genes carried on the X chromosome. An example of such a condition is familial hypophosphataemia with vitamin-D-resistant RICKETS.
Polygenic inheritance In many inherited conditions, the disease is due to the combined action of several genes; the genetic element is then called multi-factorial or polygenic. In this situation there would be an increased incidence of the disease in the families concerned, but it will not follow the Mendelian (see MENDELISM; GENETIC CODE) ratio. The greater the number of independent genes involved in determining a certain disease, the more complicated will be the pattern of inheritance. Furthermore, many inherited disorders are the result of a combination of genetic and environmental in?uences. DIABETES MELLITUS is the most familiar of such multi-factorial inheritance. The predisposition to develop diabetes is an inherited characteristic, although the gene is not always able to express itself: this is called incomplete penetrance. Whether or not the individual with a genetic predisposition towards the disease actually develops diabetes will also depend on environmental factors. Diabetes is more common in the relatives of diabetic patients, and even more so amongst identical twins. Non-genetic factors which are important in precipitating overt disease are obesity, excessive intake of carbohydrate foods, and pregnancy.
SCHIZOPHRENIA is another example of the combined effects of genetic and environmental in?uences in precipitating disease. The risk of schizophrenia in a child, one of whose parents has the disease, is one in ten, but this ?gure is modi?ed by the early environment of the child.... genetic disorders
There are also more than 200 identi?ed disorders described as inborn errors of metabolism. Some cause few problems; others are serious threats to an individual’s life. Individual disorders are, fortunately, rare – probably one child in 10,000 or 100,000; overall these inborn errors affect around one child in 1,000. Examples include GALACTOSAEMIA, PHENYLKETONURIA, porphyrias, TAY SACHS DISEASE and varieties of mucopolysaccharidosis, HOMOCYSTINURIA and hereditary fructose (a type of sugar) intolerance.... metabolic disorders
Characteristic white streaks appear on the optic fundi (see EYE). Molecular genetic testing can identify up to 90 per cent of individuals with a tuberin gene. Genetic counselling of families is helpful. Relatives of those with this condition can obtain help and guidance from the Tuberous Sclerosis Association of Great Britain.... tuberous sclerosis
Symptoms of ataxia depend on the site of damage, although a lurching, unsteady gait is common to most forms. In addition, damage to certain parts of the brain may cause nystagmus and slurred speech. CT scanning or MRI may be used to determine the cause of ataxia. Treatment of the condition depends on the cause.... ataxia
Loss of sex drive and a reduction in the size of the testes are often the first signs. Excess iron over a period of time causes liver enlargement and cirrhosis, and can lead to diabetes mellitus, bronzed skin coloration, cardiac arrhythmia, and, eventually, liver failure and liver cancer.
Diagnosis is based on blood tests and a liver biopsy. Treatment is by regular venesection. (See also haemosiderosis.)... haemochromatosis
The chorea usually affects the face, arms, and trunk, resulting in random grimaces and twitches, and clumsiness. Dementia takes the form of irritability, personality and behavioural changes, memory loss, and apathy.
At present, there is no cure for Huntington’s disease, and treatment is aimed at reducing symptoms with drugs.... huntington’s disease
There are 3 main types. In hypertrophic cardiomyopathy, which is usually inherited, the heart muscle is abnormally thickened. In dilated cardiomyopathy, metabolism of the heart muscle cells is abnormal and the walls of the heart tend to balloon out under pressure. Restrictive cardiomyopathy is caused by scarring of the endocardium (the inner lining of the heart) or by amyloidosis.
Symptoms of cardiomyopathy include fatigue, chest pain, and palpitations. The condition may lead to heart failure, symptoms of which include breathing difficulty and oedema. A chest X-ray may show enlargement of the heart, and echocardiography may show thickened heart muscle. A biopsy of heart muscle may reveal muscle cell abnormalities.
Symptoms may be treated with diuretic drugs to control heart failure and antiarrhythmic drugs to correct abnormal heart rhythm. In many cases, heart muscle function deteriorates, and the only remaining option is a heart transplant.... cardiomyopathy
A myopathy may be an inherited disorder, such as muscular dystrophy; it may also be caused by chemical poisoning, a chronic disorder of the immune system, or a metabolic disorder.... myopathy
The most common type of motor neuron disease is amyotrophic lateral sclerosis ( or Lou Gehrig’s disease). It usually affects people over the age of 50 and is more common in men. Some cases run in families. Usually, symptoms start with weakness in the hands and arms or legs, and muscle wasting. There may be irregular muscle contractions, and muscle cramps or stiffness. All four extremities are soon affected.
Progressive muscular atrophy and progressive bulbar palsy both start with patterns of muscle weakness different from but usually develop into.There are 2 types of motor neuron disease that first appear in childhood or adolescence. In most cases, these conditions are inherited. Werdnig–Hoffman disease affects infants at birth or soon afterwards. In almost all cases, progressive muscle weakness leads to death within several years. Chronic spinal muscular atrophy begins in childhood or adolescence, causing progressive weakness but not always serious disability.
There are no specific tests for motor neuron disease. Diagnosis is based on careful clinical examination by a neurologist. Tests including EMG, muscle biopsy, blood tests, myelography, CT scanning, or MRI may be performed.
The disease typically goes on to affect the muscles involved in breathing and swallowing, leading to death within 2–4 years. However, about 10 per cent of sufferers survive for 10 years.
Nerve degeneration cannot be slowed down, but physiotherapy and the use of various aids may help to reduce disability. The drug riluzole is used to extend life (or the time until mechanical ventilation is required).... motor neuron disease
The most common and severe form of muscular dystrophy is Duchenne muscular dystrophy. This is caused by a recessive gene carried on the X chromosome (see sex-linked inheritance). Boys only have one X chromosome, so if they inherit a copy of the defective gene from their mother they develop the disorder. Girls (with two X chromosomes) are not affected but become carriers of the defective gene. Affected boys walk with a waddle, find climbing difficult, and may have curvature of the spine. The disorder progresses rapidly: the ability to walk is lost by the age of 12, and few boys survive beyond the teenage years.
Becker’s muscular dystrophy starts later in childhood and progresses more slowly. Myotonic dystrophy affects the
muscles of the hands, face, neck, and feet, and causes learning difficulties. Limb-girdle muscular dystrophy mainly affects muscles in the hips and shoulders, and facioscapulohumeral muscular dystrophy affects muscles in the upper arms, shoulder girdle, and face. In this last form, severe disability is rare.
A diagnosis for Duchenne muscular dystrophy can be made with gene testing before symptoms develop. Once muscle weakness develops other tests become useful, including measurement of muscle enzymes and an EMG.
There is no cure, and physiotherapy is the main treatment. Remaining as active as possible keeps healthy muscles in good condition. Surgery to the
heel tendons may assist walking in some cases. The long-term outlook depends on the particular form.
Families in which a child or adult has developed any form of muscular dystrophy should receive genetic counselling.... muscular dystrophy
Most treatments for osteopetrosis aim to reduce the severity of symptoms. Bone marrow transplants of cells from which healthy bone cells might develop are undertaken in some cases.... osteopetrosis
Surgical removal of neurofibromas is necessary only if there are complications.
Anyone with this disorder, and parents of an affected child, should seek genetic counselling if planning a pregnancy.... neurofibromatosis
Phenylalanine is found in most proteincontaining foods and in artificial sweeteners.
A specially modified diet is generally recommended throughout life, (and especially during pregnancy, because high phenylalanine levels in the mother can damage the fetus).... phenylketonuria
These abnormal red cells are readily broken up when blood passes through the spleen.
At times, the rate of red cell destruction exceeds the rate at which new cells can be made in the bone marrow, leading to symptoms of anaemia.
Other symptoms include jaundice and enlargement of the spleen.
Occasionally, crises occur (usually triggered by infection) in which all symptoms worsen.
Gallstones are a frequent complication.
Splenectomy usually leads to permanent improvement.... hereditary
The disease is diagnosed by bloodclotting tests and measurement of blood levels of von Willebrand factor. Bleeding episodes can be prevented or controlled by desmopressin (a substance resembling ADH). Factor or concentrated von Willebrand factor may also be used to treat bleeding.... von willebrand’s disease
The group of arthropod insects that include the parasitic MITES and TICKS.... acanthosis nigricans
When virilisation is noted at birth, great care must be taken to determine genetic sex by karyotyping: parents should be reassured as to the baby’s sex (never ‘in between’). Blood levels of adrenal hormones are measured to obtain a precise diagnosis. Traditionally, doctors have advised parents to ‘choose’ their child’s gender on the basis of discussing the likely condition of the genitalia after puberty. Thus, where the phallus is likely to be inadequate as a male organ, it may be preferred to rear the child as female. Surgery is usually advised in the ?rst two years to deal with clitoromegaly but parent/ patient pressure groups, especially in the US, have declared it wrong to consider surgery until the children are competent to make their own decision.
Other treatment requires replacement of the missing hormones which, if started early, may lead to normal sexual development. There is still controversy surrounding the ethics of gender reassignment.
See www.baps.org.uk... adrenogenital syndrome
In Britain, anaemia is much more common among women than men. Thus, around 10 per cent of girls have anaemia at the age of 15, whilst in adult life the incidence is over 30 per cent between the ages of 30 and 40, around 20 per cent at 50, and around 30 per cent at 70. Among men the incidence is under 5 per cent until the age of 50; it then rises to 20 per cent at the age of 70. Ninety per cent of all cases of anaemia in Britain are microcytic, 7 per cent are macrocytic, and 3 per cent are haemolytic or aplastic. Inherited anaemias include sickle-cell anaemia and THALASSAEMIA.... anaemia
Disorders that can be helped or even cured include certain types of LEUKAEMIA and many inherited disorders of the immune system (see IMMUNITY).... bone marrow transplant
Nutritional Profile Energy value (calories per serving): Moderate to high Protein: Moderate to high Fat: Low to high Saturated fat: High Cholesterol: Low to high Carbohydrates: Low Fiber: None Sodium: High Major vitamin contribution: Vitamin A, vitamin D, B vitamins Major mineral contribution: Calcium
About the Nutrients in This Food Cheese making begins when Lactobacilli and/or Streptococci bacteria are added to milk. The bacteria digest lactose (milk sugar) and release lactic acid, which coagulates casein (milk protein) into curds. Rennet (gastric enzymes extracted from the stomach of calves) is added, and the mixture is put aside to set. The longer the curds are left to set, the firmer the cheese will be. When the curds are properly firm, they are pressed to squeeze out the whey (liquid) and cooked. Cooking evaporates even more liquid and makes the cheese even firmer.* At this point, the product is “fresh” or “green” cheese: cottage cheese, cream cheese, farmer cheese. Making “ripe” cheese requires the addition of salt to pull out more moisture and specific organisms, such as Penicil- lium roquefort for Roquefort cheese, blue cheese, and Stilton, or Penicillium cambembert for Camembert and Brie. The nutritional value of cheese is similar to the milk from which it is made. All cheese is a good source of high quality proteins with sufficient amounts of all the essential amino acids. Cheese is low to high in fat, mod- erate to high in cholesterol. * Natural cheese is cheese made direct ly from milk. Processed cheese is natural cheese melted and combined wit h emulsifiers. Pasteurized process cheese foods contain ingredients t hat allow t hem to spread smoot hly; t hey are lower in fat and higher in moisture t han processed cheese. Cholesterol and Saturated Fat Content of Selected Cheeses Mozzarella Source: USDA, Nutritive Value of Foods, Home and Garden Bullet in No. 72 (USDA, 1989). All cheeses, except cottage cheese, are good sources of vitamin A. Orange and yellow cheeses are colored with carotenoid pigments, including bixin (the carotenoid pigment in annatto) and synthetic beta-carotene. Hard cheeses are an excellent source of calcium; softer cheeses are a good source; cream cheese and cottage cheese are poor sources. The R DA for calcium is 1,000 mg for a woman, 1,200 mg for a man, and 1,500 mg for an older woman who is not on hormone- replacement therapy. All cheese, unless otherwise labeled, is high in sodium.
| Calcium Content of Cheese | ||
| Cheese | Serving | Calcium (mg) |
| Blue | oz. | 150 |
| Camembert | wedge | 147 |
| Cheddar | oz. | 204 |
| Cottage cheese | ||
| creamed | cup | 135 |
| uncreamed | cup | 46 |
| Muenster | oz. | 203 |
| Pasteurized processed American | oz. | 174 |
| Parmesan grated | tbsp. | 69 |
| Provolone | oz. | 214 |
| Swiss | oz. | 272 |
The Most Nutritious Way to Serve This Food With grains, bread, noodles, beans, nuts, or vegetables to add the essential amino acids miss- ing from these foods, “complete” their proteins, and make them more nutritionally valuable.
Diets That May Restrict or Exclude This Food Antiflatulence diet Controlled-fat, low-cholesterol diet Lactose- and galactose-free diet (lactose, a disaccharide [double sugar] is composed of one unit of galactose and one unit of glucose) Low-calcium diet (for patients with kidney disease) Sucrose-free diet (processed cheese)
Buying This Food Look for: Cheese stored in a refrigerated case. Check the date on the package. Avoid: Any cheese with mold that is not an integral part of the food.
Storing This Food Refrigerate all cheese except unopened canned cheeses (such as Camembert in tins) or grated cheeses treated with preservatives and labeled to show that they can be kept outside the refrigerator. Some sealed packages of processed cheeses can be stored at room temperature but must be refrigerated once the package is opened. Wrap cheeses tightly to protect them from contamination by other microorganisms in the air and to keep them from drying out. Well-wrapped, refrigerated hard cheeses that have not been cut or sliced will keep for up to six months; sliced hard cheeses will keep for about two weeks. Soft cheeses (cottage cheese, ricotta, cream cheese, and Neufchatel) should be used within five to seven days. Use all packaged or processed cheeses by the date stamped on the package. Throw out moldy cheese (unless the mold is an integral part of the cheese, as with blue cheese or Stilton).
Preparing This Food To grate cheese, chill the cheese so it won’t stick to the grater. The molecules that give cheese its taste and aroma are largely immobilized when the cheese is cold. When serving cheese with fruit or crackers, bring it to room temperature to activate these molecules.
What Happens When You Cook This Food Heat changes the structure of proteins. The molecules are denatured, which means that they may be broken into smaller fragments or change shape or clump together. All of these changes may force moisture out of the protein tissue, which is why overcooked cheese is often stringy. Whey proteins, which do not clump or string at low temperatures, contain the sulfur atoms that give hot or burned cheese an unpleasant “cooked” odor. To avoid both strings and an unpleasant odor, add cheese to sauces at the last minute and cook just long enough to melt the cheese.
How Other Kinds of Processing Affect This Food Freezing. All cheese loses moisture when frozen, so semisoft cheeses will freeze and thaw better than hard cheeses, which may be crumbly when defrosted. Drying. The less moisture cheese contains, the less able it is to support the growth of organ- isms like mold. Dried cheeses keep significantly longer than ordinary cheeses.
Medical Uses and/or Benefits To strengthen bones and reduce age-related loss of bone density. High-calcium foods protect bone density. The current recommended dietary allowance (R DA) for calcium is still 800 mg for adults 25 and older, but a 1984 National Institutes of Health (NIH) Conference advisory stated that lifelong protection for bones requires an R DA of 1,000 mg for healthy men and women age 25 to 50 ; 1,000 mg for older women using hormone replacement therapy; and 1,500 mg for older women who are not using hormones, and these recommendations have been confirmed in a 1994 NIH Consensus Statement on optimal calcium intake. A diet with adequate amounts of calcium-rich foods helps protect bone density. Low-fat and no-fat cheeses provide calcium without excess fat and cholesterol. Protection against tooth decay. Studies at the University of Iowa (Iowa City) Dental School confirm that a wide variety of cheeses, including aged cheddar, Edam, Gouda, Monterey Jack, Muenster, mozzarella, Port Salut, Roquefort, Romano, Stilton, Swiss, and Tilsit—limit the tooth decay ordinarily expected when sugar becomes trapped in plaque, the sticky film on tooth surfaces where cavity-causing bacteria flourish. In a related experiment using only cheddar cheese, people who ate cheddar four times a day over a two-week period showed a 20 percent buildup of strengthening minerals on the surface of synthetic toothlike material attached to the root surfaces of natural teeth. Protection against periodontal disease. A report in the January 2008 issue of the Journal of Periodontology suggests that consuming adequate amounts of dairy products may reduce the risk of developing periodontal disease. Examining the dental health of 942 subjects ages 40 to 79, researchers at Kyushu University, in Japan, discovered that those whose diets regularly included two ounces (55 g) of foods containing lactic acid (milk, cheese, and yogurt) were significantly less likely to have deep “pockets” (loss of attachment of tooth to gum) than those who consumed fewer dairy products.
Adverse Effects Associated with This Food Increased risk of heart disease. Like other foods from animals, cheese is a source of choles- terol and saturated fats, which increase the amount of cholesterol circulating in your blood and raise your risk of heart disease. To reduce the risk of heart disease, the USDA /Health and Human Services Dietary Guidelines for Americans recommends limiting the amount of cholesterol in your diet to no more than 300 mg a day. The guidelines also recommend limit- ing the amount of fat you consume to no more than 30 percent of your total calories, while holding your consumption of saturated fats to more than 10 percent of your total calories (the calories from saturated fats are counted as part of the total calories from fat). Food poisoning. Cheese made from raw (unpasteurized) milk may contain hazardous microorganisms, including Salmonella and Listeria. Salmonella causes serious gastric upset; Lis- teria, a flulike infection, encephalitis, or blood infection. Both may be life-threatening to the very young, the very old, pregnant women, and those whose immune systems are weakened either by illness (such as AIDS) or drugs (such as cancer chemotherapy). In 1998, the Federal Centers for Disease Control (CDC) released data identif ying Listeria as the cause of nearly half the reported deaths from food poisoning. Allergy to milk proteins. Milk is one of the foods most frequently implicated as a cause of allergic reactions, particularly upset stomach. However, in many cases the reaction is not a true allergy but the result of lactose intolerance (see below). Lactose intolerance. Lactose intolerance—the inability to digest the sugar in milk—is an inherited metabolic deficiency that affects two thirds of all adults, including 90 to 95 percent of all Orientals, 70 to 75 percent of all blacks, and 6 to 8 percent of Caucasians. These people do not have sufficient amounts of lactase, the enzyme that breaks the disaccharide lactose into its easily digested components, galactose and glucose. When they drink milk, the undi- gested sugar is fermented by bacteria in the gut, causing bloating, diarrhea, flatulence, and intestinal discomfort. Some milk is now sold with added lactase to digest the lactose and make the milk usable for lactase-deficient people. In making cheese, most of the lactose in milk is broken down into glucose and galactose. There is very little lactose in cheeses other than the fresh ones—cottage cheese, cream cheese, and farmer cheese. Galactosemia. Galactosemia is an inherited metabolic disorder in which the body lacks the enzymes needed to metabolize galactose, a component of lactose. Galactosemia is a reces- sive trait; you must receive the gene from both parents to develop the condition. Babies born with galactosemia will fail to thrive and may develop brain damage or cataracts if they are given milk. To prevent this, children with galactosemia are usually kept on a protective milk- free diet for several years, until their bodies have developed alternative pathways by which to metabolize galactose. Pregnant women who are known carriers of galactosemia may be advised to give up milk and milk products while pregnant lest the unmetabolized galactose in their bodies cause brain damage to the fetus (damage not detectable by amniocentesis). Genetic counseling is available to identif y galactosemia carriers and assess their chances of producing a baby with the disorder. Penicillin sensitivity. People who experience a sensitivity reaction the first time they take penicillin may have been sensitized by exposure to the Penicillium molds in the environment, including the Penicillium molds used to make brie, blue, camembert, roquefort, Stilton, and other “blue” cheeses.
Food/Drug Interactions Tetracycline. The calcium ions in milk products, including cheese, bind tetracyclines into insoluble compounds. If you take tetracyclines with cheese, your body may not be able to absorb and use the drug efficiently. Monoamine oxidase (MAO) inhibitors. Monoamine oxidase inhibitors are drugs used to treat depression. They inactivate naturally occurring enzymes in your body that metabolize tyra- mine, a substance found in many fermented or aged foods. Tyramine constricts blood ves- sels and increases blood pressure. If you eat a food such as aged or fermented cheese which is high in tyramine while you are taking an M AO inhibitor, your body may not be able to eliminate the tyramine. The result may be a hypertensive crisis.
Tyramine Content of Cheeses High Boursault, Camembert, Cheddar, Emmenthaler, Stilton Medium to high Blue, brick, Brie, Gruyère, mozzarella, Parmesan, Romano, Roquefort Low Processed American cheese Very little or none Cottage and cream cheese Sources: The Medical Letter Handbook of Adverse Drug Interactions (1985); Handbook of Clinical Dietetics ( The A merican Dietet ic Associat ion, 1981). False-positive test for pheochromocytoma. Pheochromocytomas (tumors of the adrenal glands) secrete adrenalin that is converted by the body to vanillyl-mandelic acid ( VM A) and excreted in the urine. Tests for this tumor measure the level of VM A in the urine. Since cheese contains VM A, taking the test after eating cheese may result in a false-positive result. Ordinarily, cheese is prohibited for at least 72 hours before this diagnostic test.... cheese
Astigmatism (See ASTIGMATISM.)
Blepharitis A chronic in?ammation of the lid margins. SEBORRHOEA and staphylococcal infection are likely contributors. The eyes are typically intermittently red, sore and gritty over months or years. Treatment is di?cult and may fail. Measures to reduce debris on the lid margins, intermittent courses of topical antibiotics, steroids or systemic antibiotics may help the sufferer.
Blepharospasm Involuntary closure of the eye. This may accompany irritation but may also occur without an apparent cause. It may be severe enough to interfere with vision. Treatment involves removing the source of irritation, if present. Severe and persistent cases may respond to injection of Botulinum toxin into the orbicularis muscle.
Cataract A term used to describe any opacity in the lens of the eye, from the smallest spot to total opaqueness. The prevalence of cataracts is age-related: 65 per cent of individuals in their sixth decade have some degree of lens opacity, while all those over 80 are affected. Cataracts are the most important cause of blindness worldwide. Symptoms will depend on whether one or both eyes are affected, as well as the position and density of the cataract(s). If only one eye is developing a cataract, it may be some time before the person notices it, though reading may be affected. Some people with cataracts become shortsighted, which in older people may paradoxically ‘improve’ their ability to read. Bright light may worsen vision in those with cataracts.
The extent of visual impairment depends on the nature of the cataracts, and the ?rst symptoms noticed by patients include di?culty in recognising faces and in reading, while problems watching television or driving, especially at night, are pointers to the condition. Cataracts are common but are not the only cause of deteriorating vision. Patients with cataracts should be able to point to the position of a light and their pupillary reactions should be normal. If a bright light is shone on the eye, the lens may appear brown or, in advanced cataracts, white (see diagram).
While increasing age is the commonest cause of cataract in the UK, patients with DIABETES MELLITUS, UVEITIS and a history of injury to the eye can also develop the disorder. Prolonged STEROID treatment can result in cataracts. Children may develop cataracts, and in them the condition is much more serious as vision may be irreversibly impaired because development of the brain’s ability to interpret visual signals is hindered. This may happen even if the cataracts are removed, so early referral for treatment is essential. One of the physical signs which doctors look for when they suspect cataract in adults as well as in children is the ‘red re?ex’. This is observable when an ophthalmoscopic examination of the eye is made (see OPHTHALMOSCOPE). Identi?cation of this red re?ex (a re?ection of light from the red surface of the retina –see EYE) is a key diagnostic sign in children, especially young ones.
There is no e?ective medical treatment for established cataracts. Surgery is necessary and the decision when to operate depends mainly on how the cataract(s) affect(s) the patient’s vision. Nowadays, surgery can be done at any time with limited risk. Most patients with a vision of 6/18 – 6/10 is the minimum standard for driving – or worse in both eyes should
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bene?t from surgery, though elderly people may tolerate visual acuity of 6/18 or worse, so surgery must be tailored to the individual’s needs. Younger people with a cataract will have more demanding visual requirements and so may opt for an ‘earlier’ operation. Most cataract surgery in Britain is now done under local anaesthetic and uses the ‘phaco-emulsi?cation’ method. A small hole is made in the anterior capsule of the lens after which the hard lens nucleus is liqui?ed ultrasonically. A replacement lens is inserted into the empty lens bag (see diagram). Patients usually return to their normal activities within a few days of the operation. A recent development under test in the USA for children requiring cataract operations is an intra-ocular ?exible implant whose magnifying power can be altered as a child develops, thus precluding the need for a series of corrective operations as happens now.
Chalazion A ?rm lump in the eyelid relating to a blocked meibomian gland, felt deep within the lid. Treatment is not always necessary; a proportion spontaneously resolve. There can be associated infection when the lid becomes red and painful requiring antibiotic treatment. If troublesome, the chalazion can be incised under local anaesthetic.
Conjunctivitis In?ammation of the conjunctiva (see EYE) which may affect one or both eyes. Typically the eye is red, itchy, sticky and gritty but is not usually painful. Redness is not always present. Conjunctivitis can occasionally be painful, particularly if there is an associated keratitis (see below) – for example, adenovirus infection, herpetic infection.
The cause can be infective (bacteria, viruses or CHLAMYDIA), chemical (e.g. acids, alkalis) or allergic (e.g. in hay fever). Conjunctivitis may also be caused by contact lenses, and preservatives or even the drugs in eye drops may cause conjunctival in?ammation. Conjunctivitis may addtionally occur in association with other illnesses – for example, upper-respiratory-tract infection, Stevens-Johnson syndrome (see ERYTHEMA – erythema multiforme) or REITER’S SYNDROME. The treatment depends on the cause. In many patients acute conjunctivitis is self-limiting.
Dacryocystitis In?ammation of the lacrimal sac. This may present acutely as a red, painful swelling between the nose and the lower lid. An abscess may form which points through the skin and which may need to be drained by incision. Systemic antibiotics may be necessary. Chronic dacryocystitis may occur with recurrent discharge from the openings of the tear ducts and recurrent swelling of the lacrimal sac. Obstruction of the tear duct is accompanied by watering of the eye. If the symptoms are troublesome, the patient’s tear passageways need to be surgically reconstructed.
Ectropion The lid margin is everted – usually the lower lid. Ectropion is most commonly associated with ageing, when the tissues of the lid become lax. It can also be caused by shortening of the skin of the lids such as happens with scarring or mechanical factors – for example, a tumour pulling the skin of the lower lid downwards. Ectropion tends to cause watering and an unsightly appearance. The treatment is surgical.
Entropion The lid margin is inverted – usually the lower lid. Entropion is most commonly associated with ageing, when the tissues of the lid become lax. It can also be caused by shortening of the inner surfaces of the lids due to scarring – for example, TRACHOMA or chemical burns. The inwardly directed lashes cause irritation and can abrade the cornea. The treatment is surgical.
Episcleritis In?ammation of the EPISCLERA. There is usually no apparent cause. The in?ammation may be di?use or localised and may affect one or both eyes. It sometimes recurs. The affected area is usually red and moderately painful. Episcleritis is generally not thought to be as painful as scleritis and does not lead to the same complications. Treatment is generally directed at improving the patient’s symptoms. The in?ammation may respond to NON-STEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDS) or topical CORTICOSTEROIDS.
Errors of refraction (Ametropia.) These will occur when the focusing power of the lens and cornea does not match the length of the eye, so that rays of light parallel to the visual axis are not focused at the fovea centralis (see EYE). There are three types of refractive error: HYPERMETROPIA or long-sightedness. The refractive power of the eye is too weak, or the eye is too short so that rays of light are brought to a focus at a point behind the retina. Longsighted people can see well in the distance but generally require glasses with convex lenses for reading. Uncorrected long sight can lead to headaches and intermittent blurring of vision following prolonged close work (i.e. eye strain). As a result of ageing, the eye becomes gradually long-sighted, resulting in many people needing reading glasses in later life: this normal process is known as presbyopia. A particular form of long-sightedness occurs after cataract extraction (see above). MYOPIA(Short sight or near sight.) Rays of light are brought to a focus in front of the retina because the refractive power of the eye is too great or the eye is too short. Short-sighted people can see close to but need spectacles with concave lenses in order to see in the distance. ASTIGMATISMThe refractive power of the eye is not the same in each meridian. Some rays of light may be focused in front of the retina while others are focused on or behind the retina. Astigmatism can accompany hypermetropia or myopia. It may be corrected by cylindrical lenses: these consist of a slice from the side of a cylinder (i.e. curved in one meridian and ?at in the meridian at right-angles to it).
Keratitis In?ammation of the cornea in response to a variety of insults – viral, bacterial, chemical, radiation, or mechanical trauma. Keratitis may be super?cial or involve the deeper layers, the latter being generally more serious. The eye is usually red, painful and photophobic. Treatment is directed at the cause.
Nystagmus Involuntary rhythmic oscillation of one or both eyes. There are several causes including nervous disorders, vestibular disorders, eye disorders and certain drugs including alcohol.
Ophthalmia In?ammation of the eye, especially the conjunctiva (see conjunctivitis, above). Ophthalmia neonatorum is a type of conjunctivitis that occurs in newborn babies. They catch the disease when passing through an infected birth canal during their mother’s labour (see PREGNANCY AND LABOUR). CHLAMYDIA and GONORRHOEA are the two most common infections. Treatment is e?ective with antibiotics: untreated, the infection may cause permanent eye damage.
Pinguecula A benign degenerative change in the connective tissue at the nasal or temporal limbus (see EYE). This is visible as a small, ?attened, yellow-white lump adjacent to the cornea.
Pterygium Overgrowth of the conjunctival tissues at the limbus on to the cornea (see EYE). This usually occurs on the nasal side and is associated with exposure to sunlight. The pterygium is surgically removed for cosmetic reasons or if it is thought to be advancing towards the visual axis.
Ptosis Drooping of the upper lid. May occur because of a defect in the muscles which raise the lid (levator complex), sometimes the result of ageing or trauma. Other causes include HORNER’S SYNDROME, third cranial nerve PALSY, MYASTHENIA GRAVIS, and DYSTROPHIA MYOTONICA. The cause needs to be determined and treated if possible. The treatment for a severely drooping lid is surgical, but other measures can be used to prop up the lid with varying success.
Retina, disorders of The retina can be damaged by disease that affects the retina alone, or by diseases affecting the whole body.
Retinopathy is a term used to denote an abnormality of the retina without specifying a cause. Some retinal disorders are discussed below. DIABETIC RETINOPATHY Retinal disease occurring in patients with DIABETES MELLITUS. It is the commonest cause of blind registration in Great Britain of people between the ages of 20 and 65. Diabetic retinopathy can be divided into several types. The two main causes of blindness are those that follow: ?rst, development of new blood vessels from the retina, with resultant complications and, second, those following ‘water logging’ (oedema) of the macula. Treatment is by maintaining rigid control of blood-sugar levels combined with laser treatment for certain forms of the disease – in particular to get rid of new blood vessels. HYPERTENSIVE RETINOPATHY Retinal disease secondary to the development of high blood pressure. Treatment involves control of the blood pressure (see HYPERTENSION). SICKLE CELL RETINOPATHY People with sickle cell disease (see under ANAEYIA) can develop a number of retinal problems including new blood vessels from the retina. RETINOPATHY OF PREMATURITY (ROP) Previously called retrolental ?broplasia (RLF), this is a disorder affecting low-birth-weight premature babies exposed to oxygen. Essentially, new blood vessels develop which cause extensive traction on the retina with resultant retinal detachment and poor vision. RETINAL ARTERY OCCLUSION; RETINAL VEIN OCCLUSION These result in damage to those areas of retina supplied by the affected blood vessel: the blood vessels become blocked. If the peripheral retina is damaged the patient may be completely symptom-free, although areas of blindness may be detected on examination of ?eld of vision. If the macula is involved, visual loss may be sudden, profound and permanent. There is no e?ective treatment once visual loss has occurred. SENILE MACULAR DEGENERATION (‘Senile’ indicates age of onset and has no bearing on mental state.) This is the leading cause of blindness in the elderly in the western world. The average age of onset is 65 years. Patients initially notice a disturbance of their vision which gradually progresses over months or years. They lose the ability to recognise ?ne detail; for example, they cannot read ?ne print, sew, or recognise people’s faces. They always retain the ability to recognise large objects such as doors and chairs, and are therefore able to get around and about reasonably well. There is no e?ective treatment in the majority of cases. RETINITIS PIGMENTOSAA group of rare, inherited diseases characterised by the development of night blindness and tunnel vision. Symptoms start in childhood and are progressive. Many patients retain good visual acuity, although their peripheral vision is limited. One of the characteristic ?ndings on examination is collections of pigment in the retina which have a characteristic shape and are therefore known as ‘bone spicules’. There is no e?ective treatment. RETINAL DETACHMENTusually occurs due to the development of a hole in the retina. Holes can occur as a result of degeneration of the retina, traction on the retina by the vitreous, or injury. Fluid from the vitreous passes through the hole causing a split within the retina; the inner part of the retina becomes detached from the outer part, the latter remaining in contact with the choroid. Detached retina loses its ability to detect light, with consequent impairment of vision. Retinal detachments are more common in the short-sighted, in the elderly or following cataract extraction. Symptoms include spots before the eyes (?oaters), ?ashing lights and a shadow over the eye with progressive loss of vision. Treatment by laser is very e?ective if caught early, at the stage when a hole has developed in the retina but before the retina has become detached. The edges of the hole can be ‘spot welded’ to the underlying choroid. Once a detachment has occurred, laser therapy cannot be used; the retina has to be repositioned. This is usually done by indenting the wall of the eye from the outside to meet the retina, then making the retina stick to the wall of the eye by inducing in?ammation in the wall (by freezing it). The outcome of surgery depends largely on the extent of the detachment and its duration. Complicated forms of detachment can occur due to diabetic eye disease, injury or tumour. Each requires a specialised form of treatment.
Scleritis In?ammation of the sclera (see EYE). This can be localised or di?use, can affect the anterior or the posterior sclera, and can affect one or both eyes. The affected eye is usually red and painful. Scleritis can lead to thinning and even perforation of the sclera, sometimes with little sign of in?ammation. Posterior scleritis in particular may cause impaired vision and require emergency treatment. There is often no apparent cause, but there are some associated conditions – for example, RHEUMATOID ARTHRITIS, GOUT, and an autoimmune disease affecting the nasal passages and lungs called Wegener’s granulomatosis. Treatment depends on severity but may involve NON-STEROIDAL ANTI-INFLAMMATORY DRUGS (NSAIDS), topical CORTICOSTEROIDS or systemic immunosuppressive drugs.
Stye Infection of a lash follicle. This presents as a painful small red lump at the lid margin. It often resolves spontaneously but may require antibiotic treatment if it persists or recurs.
Sub-conjunctival haemorrhage Haemorrhage between the conjunctiva and the underlying episclera. It is painless. There is usually no apparent cause and it resolves spontaneously.
Trichiasis Inward misdirection of the lashes. Trichiasis occurs due to in?ammation of or trauma to the lid margin. Treatment involves removal of the patient’s lashes. Regrowth may be prevented by electrolysis, by CRYOTHERAPY to the lid margin, or by surgery.
For the subject of arti?cial eyes, see under PROSTHESIS; also GLAUCOMA, SQUINT and UVEITIS.... eye, disorders of
Specific remedial teaching can help the child develop “tricks” to overcome the deficit.
Avoidance of pressure from parents combined with praise for what the child can do is equally important.... dyslexia
Atopic eczema is a chronic, superficial inflammation that occurs in people with an inherited tendency towards allergy. The condition is common in babies. An intensely itchy rash occurs, usually on the face, in the elbow creases, and behind the knees. The skin often scales, and small red pimples may appear. For mild cases, emollients help keep the skin soft. In severe cases, corticosteroid ointments may be used. Antihistamine drugs may reduce itching. Excluding certain foods from the diet may be helpful. Atopic eczema often clears up on its own as a child grows older.
Nummular eczema usually occurs in adults. The cause is unknown. It produces circular, itchy, scaling patches anywhere on the skin, similar to those of tinea (ringworm). Topical corticosteroids may reduce the inflammation, but the disorder is often persistent.
Hand eczema is usually caused by irritant substances such as detergents, but may occur for no apparent reason. Itchy blisters develop, usually on the palms, and the skin may become scaly and cracked. Hand eczema usually improves if emollients are used and cotton gloves with rubber gloves over them are wornwhen coming into contact with irritants. If the eczema is severe, corticosteroids may be prescribed.
Stasis eczema occurs in people with varicose veins. The skin on the legs may become irritated, inflamed, and discoloured. The most important factor is swelling of the legs, which may be controlled with compression bandages or stockings. Ointments containing corticosteroids may give temporary relief.... eczema
Lactation is initiated by a rise in the level of prolactin, a hormone produced by the pituitary gland. Galactorrhoea is caused by excessive secretion of prolactin due to a pituitary tumour or otherendocrine disease, such as hypothyroidism. Some antipsychotic drugs may also cause excessive secretion. Treatment with bromocriptine suppresses prolactin production, but the underlying cause may also need treatment. galactosaemia A rare, inherited condition in which the body is unable to convert the sugar galactose into glucose due to the absence of a liver enzyme. It causes no symptoms at birth, but jaundice, diarrhoea, and vomiting soon develop and the baby fails to gain weight. Untreated, the condition results in liver disease, cataract, and learning difficulties. The diagnosis is confirmed by urine and blood tests. The major source of galactose is the milk sugar lactose. Lactosefree milk must be used throughout life. gallbladder A small, pear-shaped sac situated under the liver that stores bile. Bile, produced by the liver, passes into the gallbladder via the hepatic and cystic ducts. It is released into the intestine via the common bile duct.... galactorrhoea
The that makes up genes consists of 2 long intertwined strands, each consisting of a sequence of 4 different chemicals called nucleotide bases. These 4 bases are adenine, thymine, cytosine, and guanine (often abbreviated to A, T, C, and G). The sequence of these bases along the strands makes up the genetic code.... genetic code
History Child health services were originally designed, before the NHS came into being, to ?nd or prevent physical illness by regular inspections. In the UK these were carried out by clinical medical o?cers (CMOs) working in infant welfare clinics (later, child health clinics) set up to ?ll the gap between general practice and hospital care. The services expanded greatly from the mid 1970s; ‘inspections’ have evolved into a regular screening and surveillance system by general practitioners and health visitors, while CMOs have mostly been replaced by consultant paediatricians in community child health (CPCCH).
Screening Screening begins at birth, when every baby is examined for congenital conditions such as dislocated hips, heart malformations, cataract and undescended testicles. Blood is taken to ?nd those babies with potentially brain-damaging conditions such as HYPOTHYROIDISM and PHENYLKETONURIA. Some NHS trusts screen for the life-threatening disease CYSTIC FIBROSIS, although in future it is more likely that ?nding this disease will be part of prenatal screening, along with DOWN’S (DOWN) SYNDROME and SPINA BIFIDA. A programme to detect hearing impairment in newborn babies has been piloted from 2001 in selected districts to ?nd out whether it would be a useful addition to the national screening programme. Children from ethnic groups at risk of inherited abnormalities of HAEMOGLOBIN (sickle cell disease; thalassaemia – see under ANAEMIA) have blood tested at some time between birth and six months of age.
Illness prevention At two months, GPs screen babies again for these abnormalities and start the process of primary IMMUNISATION. The routine immunisation programme has been dramatically successful in preventing illness, handicap and deaths: as such it is the cornerstone of the public health aspect of child health, with more potential vaccines being made available every year. Currently, infants are immunised against pertussis (see WHOOPING COUGH), DIPHTHERIA, TETANUS, POLIOMYELITIS, haemophilus (a cause of MENINGITIS, SEPTICAEMIA, ARTHRITIS and epiglottitis) and meningococcus C (SEPTICAEMIA and meningitis – see NEISSERIACEAE) at two, three and four months. Selected children from high-risk groups are o?ered BCG VACCINE against tuberculosis and hepatitis vaccine. At about 13 months all are o?ered MMR VACCINE (measles, mumps and rubella) and there are pre-school entry ‘boosters’ of diphtheria, tetanus, polio, meningococcus C and MMR. Pneumococcal vaccine is available for particular cases but is not yet part of the routine schedule.
Health promotion and education Throughout the UK, parents are given their child’s personal health record to keep with them. It contains advice on health promotion, including immunisation, developmental milestones (when did he or she ?rst smile, sit up, walk and so on), and graphs – called centile charts – on which to record height, weight and head circumference. There is space for midwives, doctors, practice nurses, health visitors and parents to make notes about the child.
Throughout at least the ?rst year of life, both parents and health-care providers set great store by regular weighing, designed to pick up children who are ‘failing to thrive’. Measuring length is not quite so easy, but height measurements are recommended from about two or three years of age in order to detect children with disorders such as growth-hormone de?ciency, malabsorption (e.g. COELIAC DISEASE) and psychosocial dwar?sm (see below).
All babies have their head circumference measured at birth, and again at the eight-week check. A too rapidly growing head implies that the infant might have HYDROCEPHALUS – excess ?uid in the hollow spaces within the brain. A too slowly growing head may mean failure of brain growth, which may go hand in hand with physically or intellectually delayed development.
At about eight months, babies receive a surveillance examination, usually by a health visitor. Parents are asked if they have any concerns about their child’s hearing, vision or physical ability. The examiner conducts a screening test for hearing impairment – the so-called distraction test; he or she stands behind the infant, who is on the mother’s lap, and activates a standardised sound at a set distance from each ear, noting whether or not the child turns his or her head or eyes towards the sound. If the child shows no reaction, the test is repeated a few weeks later; if still negative then referral is made to an audiologist for more formal testing.
The doctor or health visitor will also go through the child’s developmental progress (see above) noting any signi?cant deviation from normal which merits more detailed examination. Doctors are also recommended to examine infants developmentally at some time between 18 and 24 months. At this time they will be looking particularly for late walking or failure to develop appropriate language skills.... child health
Abnormal prion proteins accumulate in the brain and the spinal cord, damaging neurones (see NEURON(E)) and producing small cavities. Diagnosis can be made by tonsil (see TONSILS) biopsy, although work is under way to develop a diagnostic blood test. Abnormal prion proteins are unusually resistant to inactivation by chemicals, heat, X-RAYS or ULTRAVIOLET RAYS (UVR). They are resistant to cellular degradation and can convert normal prion proteins into abnormal forms. Human prion diseases, along with scrapie in sheep and BSE in cattle, belong to a group of disorders known as transmissible spongiform encephalopathies. Abnormal prion proteins can transfer from one animal species to another, and variant CJD has occurred as a result of consumption of meat from cattle infected with BSE.
From 1995 to 1999, a scienti?c study of tonsils and appendixes removed at operation suggested that the prevalence of prion carriage may be as high as 120 per million. It is not known what percentage of these might go on to develop disease.
One precaution is that, since 2003, all surgical instruments used in brain biopsies have had to be quarantined and disposable instruments are now used in tonsillectomy.
Measures have also been introduced to reduce the risk of transmission of CJD from transfusion of blood products.
In the past, CJD has also been acquired from intramuscular injections of human cadaveric pituitary-derived growth hormone and corneal transplantation.
The most common form of CJD remains the sporadic variety, although the eventual incidence of variant CJD may not be known for many years.... creutzfeldt-jakob disease (cjd)
The presentation of dystonia may be focal (usually in adults) causing blepharospasm (forceful eye closure), oromandibular dystonia (spasms of the tongue and jaw), cranial dystonia/Meige syndrome/Brueghel’s syndrome (eyes and jaw both involved), spastic or spasmodic dysphonia/laryngeal dystonia (strained or whispering speech), spasmodic dysphagia (di?culty swallowing), spasmodic torti/latero/ ante/retrocollis (rotation, sideways, forward or backward tilting of the neck), dystonic writer’s cramp or axial dystonia (spasms deviating the torso). Foot dystonia occurs almost exclusively in children and adolescents. In adults, the condition usually remains focal or involves at most an adjacent body part. In children, it may spread to become generalised. The condition has always been considered rare, but commonly is either not diagnosed or mistakenly thought to be of psychological origin. It may, in fact, be half as common as MULTIPLE SCLEROSIS (MS). Similar features can occur in some subjects treated with major tranquillising drugs, in whom a predisposition to develop dystonia may be present.
One rare form, called dopa-responsive dystonia, can be largely abolished by treatment with LEVODOPA. Particularly in paediatric practice this drug will often be tried on a child with dystonia.... dystonia
Since the BSE epidemic in cattle developed in the UK in the 1980s, however, a new variant of CJD has been identi?ed and is believed to be the result of consumption of the meat of BSE-infected cattle. Studies in transgenic mice have con?rmed that BSE caused variant CJD. The new variant has affected younger people and may have a shorter incubation period. If this incubation period turns out to be the same as for the other types of CJD, however, it could be 2005– 2010 before the peak of this outbreak is reached. Over 148 people had died, or were dying, from variant CJD in the UK by the year 2005.
The appearance of BSE in cattle is believed to have been caused by a gene mutation (see GENETIC DISORDERS), although whether this mutation ?rst occurred in cattle or in some other animal remains uncertain. Although the ?rst case of BSE was o?cially reported in 1985, the ?rst cattle are thought to have been infected in the 1970s. BSE spread to epidemic proportions because cattle were fed meat and bone meal, made from the o?al of cattle suffering from or incubating the disease. Mother-to-calf transfer is another likely route of transmission, although meat and bone meal in cattle feed were the main cause of the epidemic. The epidemic reached its peak in 1992 when the incidence of newly diagnosed cases in cattle was 37,545.
A two-year UK government inquiry into the BSE epidemic concluded that BSE had caused a ‘harrowing fatal disease in humans’, and criticised o?cials for misleading the public over the risk to humans from BSE. Consequently, a compensation package for patients and relatives was made available. Meanwhile, a ban on the export of UK beef and restrictions on the type of meat and products made from beef that can be sold to the public were put in place. Although initially thought to be a problem primarily con?ned to the UK, several other countries – notably France, Germany, Spain, Switzerland and the United States – have also discovered BSE in their cattle.... encephalopathy (bse)
Arrhythmias An abnormal rate or rhythm of the heartbeat. The reason is a disturbance in the electrical impulses within the heart. Sometimes a person may have an occasional irregular heartbeat: this is called an ECTOPIC beat (or an extrasystole) and does not necessarily mean that an abnormality exists. There are two main types of arrhythmia: bradycardias, where the rate is slow – fewer than 60 beats a minute and sometimes so slow and unpredictable (heartblock) as to cause blackouts or heart failure; and tachycardia, where the rate is fast – more than 100 beats a minute. A common cause of arrhythmia is coronary artery disease, when vessels carrying blood to the heart are narrowed by fatty deposits (ATHEROMA), thus reducing the blood supply and damaging the heart tissue. This condition often causes myocardial infarction after which arrhythmias are quite common and may need correcting by DEFIBRILLATION (application of a short electric shock to the heart). Some tachycardias result from a defect in the electrical conduction system of the heart that is commonly congenital. Various drugs can be used to treat arrhythmias (see ANTIARRHYTHMIC DRUGS). If attacks constantly recur, the arrhythmia may be corrected by electrical removal of dead or diseased tissue that is the cause of the disorder. Heartblock is most e?ectively treated with an arti?cial CARDIAC PACEMAKER, a battery-activated control unit implanted in the chest.
Cardiomyopathy Any disease of the heart muscle that results in weakening of its contractions. The consequence is a fall in the e?ciency of the circulation of blood through the lungs and remainder of the body structures. The myopathy may be due to infection, disordered metabolism, nutritional excess or de?ciency, toxic agents, autoimmune processes, degeneration, or inheritance. Often, however, the cause is not identi?ed. Cardiomyopathies are less common than other types of heart diseases, and the incidence of di?erent types of myopathy (see below) is not known because patients or doctors are sometimes unaware of the presence of the condition.
The three recognised groups of cardiomyopathies are hypertrophic, dilated and restrictive.
•Hypertrophic myopathy, a familial condition, is characterised by great enlargement of the muscle of the heart ventricles. This reduces the muscle’s e?ciency, the ventricles fail to relax properly and do not ?ll suf?ciently during DIASTOLE.
In the dilated type of cardiomyopathy, both ventricles overdilate, impairing the e?ciency of contraction and causing congestion of the lungs.
In the restrictive variety, proper ?lling of the ventricles does not occur because the muscle walls are less elastic than normal. The result is raised pressure in the two atria (upper cavities) of the heart: these dilate and develop FIBRILLATION. Diagnosis can be di?cult and treatment is symptomatic, with a poor prognosis. In suitable patients, heart TRANSPLANTATION may be considered. Disorders of the heart muscle may also be
caused by poisoning – for example, heavy consumption of alcohol. Symptoms include tiredness, palpitations (quicker and sometimes irregular heartbeat), chest pain, di?culty in breathing, and swelling of the legs and hands due to accumulation of ?uid (OEDEMA). The heart is enlarged (as shown on chest X-ray) and ECHOCARDIOGRAPHY shows thickening of the heart muscle. A BIOPSY of heart muscle will show abnormalities in the cells of the heart muscle.
Where the cause of cardiomyopathy is unknown, as is the case with most patients, treatment is symptomatic using DIURETICS to control heart failure and drugs such as DIGOXIN to return the heart rhythm to normal. Patients should stop drinking alcohol. If, as often happens, the patient’s condition slowly deteriorates, heart transplantation should be considered.
Congenital heart disease accounts for 1–2 per cent of all cases of organic heart disease. It may be genetically determined and so inherited; present at birth for no obvious reason; or, in rare cases, related to RUBELLA in the mother. The most common forms are holes in the heart (atrial septal defect, ventricular septal defect – see SEPTAL DEFECT), a patent DUCTUS ARTERIOSUS, and COARCTATION OF THE AORTA. Many complex forms also exist and can be diagnosed in the womb by fetal echocardiography which can lead to elective termination of pregnancy. Surgery to correct many of these abnormalities is feasible, even for the most severe abnormalities, but may only be palliative giving rise to major diffculties of management as the children become older. Heart transplantation is now increasingly employed for the uncorrectable lesions.
Coronary artery disease Also known as ischaemic heart disease, this is a common cause of symptoms and death in the adult population. It may present for the ?rst time as sudden death, but more usually causes ANGINA PECTORIS, myocardial infarction (heart attack) or heart failure. It can also lead to a disturbance of heart rhythm. Factors associated with an increased risk of developing coronary artery disease include diabetes, cigarette smoking, high blood pressure, obesity, and a raised concentration of cholesterol in the blood. Older males are most affected.
Coronary thrombosis or acute myocardial infarction is the acute, dramatic manifestation of coronary-artery ischaemic heart disease – one of the major killing diseases of western civilisation. In 1999, ischaemic heart disease was responsible for about 115,000 deaths in England and Wales, compared with 153,000 deaths in 1988. In 1999 more than 55,600 people died of coronary thrombosis. The underlying cause is disease of the coronary arteries which carry the blood supply to the heart muscle (or myocardium). This results in narrowing of the arteries until ?nally they are unable to transport su?cient blood for the myocardium to function e?ciently. One of three things may happen. If the narrowing of the coronary arteries occurs gradually, then the individual concerned will develop either angina pectoris or signs of a failing heart: irregular rhythm, breathlessness, CYANOSIS and oedema.
If the narrowing occurs suddenly or leads to complete blockage (occlusion) of a major branch of one of the coronary arteries, then the victim collapses with acute pain and distress. This is the condition commonly referred to as a coronary thrombosis because it is usually due to the affected artery suddenly becoming completely blocked by THROMBOSIS. More correctly, it should be described as coronary occlusion, because the ?nal occluding factor need not necessarily be thrombosis.
Causes The precise cause is not known, but a wide range of factors play a part in inducing coronary artery disease. Heredity is an important factor. The condition is more common in men than in women; it is also more common in those in sedentary occupations than in those who lead a more physically active life, and more likely to occur in those with high blood pressure than in those with normal blood pressure (see HYPERTENSION). Obesity is a contributory factor. The disease is more common among smokers than non-smokers; it is also often associated with a high level of CHOLESTEROL in the blood, which in turn has been linked with an excessive consumption of animal, as opposed to vegetable, fats. In this connection the important factors seem to be the saturated fatty acids (low-density and very low-density lipoproteins [LDLs and VLDLs] – see CHOLESTEROL) of animal fats which would appear to be more likely to lead to a high level of cholesterol in the blood than the unsaturated fatty acids of vegetable fats. As more research on the subject is carried out, the arguments continue about the relative in?uence of the di?erent factors. (For advice on prevention of the disease, see APPENDIX 2: ADDRESSES: SOURCES OF INFORMATION, ADVICE, SUPPORT AND SELFHELP.)
Symptoms The presenting symptom is the sudden onset, often at rest, of acute, agonising pain in the front of the chest. This rapidly radiates all over the front of the chest and often down over the abdomen. The pain is frequently accompanied by nausea and vomiting, so that suspicion may be aroused of some acute abdominal condition such as biliary colic (see GALLBLADDER, DISEASES OF) or a perforated PEPTIC ULCER. The victim soon goes into SHOCK, with a pale, cold, sweating skin, rapid pulse and dif?culty in breathing. There is usually some rise in temperature.
Treatment is immediate relief of the pain by injections of diamorphine. Thrombolytic drugs should be given as soon as possible (‘rapid door to needle time’) and ARRHYTHMIA corrected. OXYGEN is essential and oral ASPIRIN is valuable. Treatment within the ?rst hour makes a great di?erence to recovery. Subsequent treatment includes the continued administration of drugs to relieve the pain; the administration of ANTIARRHYTHMIC DRUGS that may be necessary to deal with the heart failure that commonly develops, and the irregular action of the heart that quite often develops; and the continued administration of oxygen. Patients are usually admitted to coronary care units, where they receive constant supervision. Such units maintain an emergency, skilled, round-the-clock sta? of doctors and nurses, as well as all the necessary resuscitation facilities that may be required.
The outcome varies considerably. The ?rst (golden) hour is when the patient is at greatest risk of death: if he or she is treated, then there is a 50 per cent reduction in mortality compared with waiting until hospital admission. As each day passes the prognosis improves with a ?rst coronary thrombosis, provided that the patient does not have a high blood pressure and is not overweight. Following recovery, there should be a gradual return to work, care being taken to avoid any increase in weight, unnecessary stress and strain, and to observe moderation in all things. Smoking must stop. In uncomplicated cases patients get up and about as soon as possible, most being in hospital for a week to ten days and back at work in three months or sooner.
Valvular heart disease primarily affects the mitral and aortic valves which can become narrowed (stenosis) or leaking (incompetence). Pulmonary valve problems are usually congenital (stenosis) and the tricuspid valve is sometimes involved when rheumatic heart disease primarily affects the mitral or aortic valves. RHEUMATIC FEVER, usually in childhood, remains a common cause of chronic valvular heart disease causing stenosis, incompetence or both of the aortic and mitral valves, but each valve has other separate causes for malfunction.
Aortic valve disease is more common with increasing age. When the valve is narrowed, the heart hypertrophies and may later fail. Symptoms of angina or breathlessness are common and dizziness or blackouts (syncope) also occur. Replacing the valve is a very e?ective treatment, even with advancing age. Aortic stenosis may be caused by degeneration (senile calci?c), by the inheritance of two valvular leaflets instead of the usual three (bicuspid valve), or by rheumatic fever. Aortic incompetence again leads to hypertrophy, but dilatation is more common as blood leaks back into the ventricle. Breathlessness is the more common complaint. The causes are the same as stenosis but also include in?ammatory conditions such as SYPHILIS or ANKYLOSING SPONDYLITIS and other disorders of connective tissue. The valve may also leak if the aorta dilates, stretching the valve ring as with HYPERTENSION, aortic ANEURYSM and MARFAN’S SYNDROME – an inherited disorder of connective tissue that causes heart defects. Infection (endocarditis) can worsen acutely or chronically destroy the valve and sometimes lead to abnormal outgrowths on the valve (vegetations) which may break free and cause devastating damage such as a stroke or blocked circulation to the bowel or leg.
Mitral valve disease leading to stenosis is rheumatic in origin. Mitral incompetence may be rheumatic but in the absence of stenosis can be due to ISCHAEMIA, INFARCTION, in?ammation, infection and a congenital weakness (prolapse). The valve may also leak if stretched by a dilating ventricle (functional incompetence). Infection (endocarditis) may affect the valve in a similar way to aortic disease. Mitral symptoms are predominantly breathlessness which may lead to wheezing or waking at night breathless and needing to sit up or stand for relief. They are made worse when the heart rhythm changes (atrial ?brillation) which is frequent as the disease becomes more severe. This leads to a loss of e?ciency of up to 25 per cent and a predisposition to clot formation as blood stagnates rather than leaves the heart e?ciently. Mitral incompetence may remain mild and be of no trouble for many years, but infection must be guarded against (endocarditis prophylaxis).
Endocarditis is an infection of the heart which may acutely destroy a valve or may lead to chronic destruction. Bacteria settle usually on a mild lesion. Antibiotics taken at vulnerable times can prevent this (antibiotic prophylaxis) – for example, before tooth extraction. If established, lengthy intravenous antibiotic therapy is needed and surgery is often necessary. The mortality is 30 per cent but may be higher if the infection settles on a replaced valve (prosthetic endocarditis). Complications include heart failure, shock, embolisation (generation of small clots in the blood), and cerebral (mental) confusion.
PERICARDITIS is an in?ammation of the sac covering the outside of the heart. The sac becomes roughened and pain occurs as the heart and sac rub together. This is heard by stethoscope as a scratching noise (pericardial rub). Fever is often present and a virus the main cause. It may also occur with rheumatic fever, kidney failure, TUBERCULOSIS or from an adjacent lung problem such as PNEUMONIA or cancer. The in?ammation may cause ?uid to accumulate between the sac and the heart (e?usion) which may compress the heart causing a fall in blood pressure, a weak pulse and circulatory failure (tamponade). This can be relieved by aspirating the ?uid. The treatment is then directed at the underlying cause.... heart, diseases of
K
Diagram of glomerulus (Malpighian corpuscle).
Fortunately the body has two kidneys and, as most people can survive on one, there is a good ‘functional reserve’ of kidney tissue.
Symptoms Many patients with kidney disorders do not have any symptoms, even when the condition is quite advanced. However,
others experience loin pain associated with obstruction (renal colic) or due to infection; fevers; swelling (oedema), usually of the legs but occasionally including the face and arms; blood in the urine (haematuria); and excess quantities of urine (polyuria), including at night (nocturia), due to failure of normal mechanisms in the kidney for concentrating urine. Patients with chronic renal failure often have very di?use symptoms including nausea and vomiting, tiredness due to ANAEMIA, shortness of breath, skin irritation, pins and needles (paraesthesia) due to damage of the peripheral nerves (peripheral neuropathy), and eventually (rarely seen nowadays) clouding of consciousness and death.
Signs of kidney disease include loin tenderness, enlarged kidneys, signs of ?uid retention, high blood pressure and, in patients with end-stage renal failure, pallor, pigmentation and a variety of neurological signs including absent re?exes, reduced sensation, and a coarse ?apping tremor (asterixis) due to severe disturbance of the body’s normal metabolism.
Renal failure Serious kidney disease may lead to impairment or failure of the kidney’s ability to ?lter waste products from the blood and excrete them in the urine – a process that controls the body’s water and salt balance and helps to maintain a stable blood pressure. Failure of this process causes URAEMIA – an increase in urea and other metabolic waste products – as well as other metabolic upsets in the blood and tissues, all of which produce varying symptoms. Failure can be sudden or develop more slowly (chronic). In the former, function usually returns to normal once the underlying cause has been treated. Chronic failure, however, usually irreparably reduces or stops normal function.
Acute failure commonly results from physiological shock following a bad injury or major illness. Serious bleeding or burns can reduce blood volume and pressure to the point where blood-supply to the kidney is greatly reduced. Acute myocardial infarction (see HEART, DISEASES OF) or pancreatitis (see PANCREAS, DISORDERS OF) may produce a similar result. A mismatched blood transfusion can produce acute failure. Obstruction to the urine-?ow by a stone (calculus) in the urinary tract, a bladder tumour or an enlarged prostate can also cause acute renal failure, as can glomerulonephritis (see below) and the haemolytic-uraemia syndrome.
HYPERTENSION, DIABETES MELLITUS, polycystic kidney disease (see below) or AMYLOIDOSIS are among conditions that cause chronic renal failure. Others include stone, tumour, prostatic enlargement and overuse of analgesic drugs. Chronic failure may eventually lead to end-stage renal failure, a life-threatening situation that will need DIALYSIS or a renal transplant (see TRANSPLANTATION).
Familial renal disorders include autosomal dominant inherited polycystic kidney disease and sex-linked familial nephropathy. Polycystic kidney disease is an important cause of renal failure in the UK. Patients, usually aged 30–50, present with HAEMATURIA, loin or abdominal discomfort or, rarely, urinary-tract infection, hypertension and enlarged kidneys. Diagnosis is based on ultrasound examination of the abdomen. Complications include renal failure, hepatic cysts and, rarely, SUBARACHNOID HAEMORRHAGE. No speci?c treatment is available. Familial nephropathy occurs more often in boys than in girls and commonly presents as Alport’s syndrome (familial nephritis with nerve DEAFNESS) with PROTEINURIA, haematuria, progressing to renal failure and deafness. The cause of the disease lies in an absence of a speci?c ANTIGEN in a part of the glomerulus. The treatment is conservative, with most patients eventually requiring dialysis or transplantation.
Acute glomerulonephritis is an immune-complex disorder due to entrapment within glomerular capillaries of ANTIGEN (usually derived from B haemolytic streptococci – see STREPTOCOCCUS) antibody complexes initiating an acute in?ammatory response (see IMMUNITY). The disease affects children and young adults, and classically presents with a sore throat followed two weeks later by a fall in urine output (oliguria), haematuria, hypertension and mildly abnormal renal function. The disease is self-limiting with 90 per cent of patients spontaneously recovering. Treatment consists of control of blood pressure, reduced ?uid and salt intake, and occasional DIURETICS and ANTIBIOTICS.
Chronic glomerulonephritis is also due to immunological renal problems and is also classi?ed by taking a renal biopsy. It may be subdivided into various histological varieties as determined by renal biospy. Proteinuria of various degrees is present in all these conditions but the clinical presentations vary, as do their treatments. Some resolve spontaneously; others are treated with steroids or even the cytotoxic drug CYCLOPHOSPHAMIDE or the immunosuppressant cyclosporin. Prognoses are generally satisfactory but some patients may require renal dialysis or kidney transplantation – an operation with a good success rate.
Hydronephrosis A chronic disease in which the kidney becomes greatly distended with ?uid. It is caused by obstruction to the ?ow of urine at the pelvi-ureteric junction (see KIDNEYS – Structure). If the ureter is obstructed, the ureter proximal to the obstruction will dilate and pressure will be transmitted back to the kidney to cause hydronephrosis. Obstruction may occur at the bladder neck or in the urethra itself. Enlargement of the prostate is a common cause of bladder-neck obstruction; this would give rise to hypertrophy of the bladder muscle and both dilatation of the ureter and hydronephrosis. If the obstruction is not relieved, progressive destruction of renal tissue will occur. As a result of the stagnation of the urine, infection is probable and CYSTITIS and PYELONEPHRITIS may occur.
Impaired blood supply may be the outcome of diabetes mellitus and physiological shock, which lowers the blood pressure, also affecting the blood supply. The result can be acute tubular necrosis. POLYARTERITIS NODOSA and SYSTEMIC LUPUS ERYTHEMATOSUS (SLE) may damage the large blood vessels in the kidney. Treatment is of the underlying condition.
Infection of the kidney is called pyelonephritis, a key predisposing factor being obstruction of urine ?ow through the urinary tract. This causes stagnation and provides a fertile ground for bacterial growth. Acute pyelonephritis is more common in women, especially during pregnancy when bladder infection (CYSTITIS) spreads up the ureters to the kidney. Symptoms are fever, malaise and backache. Antibiotics and high ?uid intake are the most e?ective treatment. Chronic pyelonephritis may start in childhood as a result of congenital deformities that permit urine to ?ow up from the bladder to the kidney (re?ux). Persistent re?ux leads to recurrent infections causing permanent damage to the kidney. Specialist investigations are usually required as possible complications include hypertension and kidney failure.
Tumours of the kidney are fortunately rare. Non-malignant ones commonly do not cause symptoms, and even malignant tumours (renal cell carcinoma) may be asymptomatic for many years. As soon as symptoms appear – haematuria, back pain, nausea, malaise, sometimes secondary growths in the lungs, bones or liver, and weight loss – urgent treatment including surgery, radiotherapy and chemotherapy is necessary. This cancer occurs mostly in adults over 40 and has a hereditary element. The prognosis is not good unless diagnosed early. In young children a rare cancer called nephroblastoma (Wilm’s tumour) can occur; treatment is with surgery, radiotherapy and chemotherapy. It may grow to a substantial size before being diagnosed.
Cystinuria is an inherited metabolic defect in the renal tubular reabsorption of cystine, ornithine, lysine and arginine. Cystine precipitates in an alkaline urine to form cystine stones. Triple phosphate stones are associated with infection and may develop into a very large branching calculi (staghorn calculi). Stones present as renal or ureteric pain, or as an infection. Treatment has undergone considerable change with the introduction of MINIMALLY INVASIVE SURGERY (MIS) and the destruction of stone by sound waves (LITHOTRIPSY).... kidneys, diseases of
In hemiplegia, or PARALYSIS down one side of the body following a STROKE, the person drags the paralysed leg.
Steppage gait occurs in certain cases of alcoholic NEURITIS, tertiary SYPHILIS (tabes) and other conditions where the muscles that raise the foot are weak so that the toes droop. The person bends the knee and lifts the foot high, so that the toes may clear obstacles on the ground. (See DROP-FOOT.)
In LOCOMOTOR ATAXIA or tabes dorsalis, the sensations derived from the lower limbs are blunted, and consequently the movements of the legs are uncertain and the heels planted upon the ground with unnecessary force. When the person tries to turn or stands with the eyes shut, he or she may fall over. When they walk, they feel for the ground with a stick or keep their eyes constantly ?xed upon it.
In spastic paralysis the limbs are moved with jerks. The foot ?rst of all clings to the ground and then leaves it with a spasmodic movement, being raised much higher than is necessary.
In PARKINSONISM the movements are tremulous, and as the person takes very short steps, he or she has the peculiarity of appearing constantly to fall forwards, or to be chasing themselves.
In CHOREA the walk is bizarre and jerky, the affected child often seeming to leave one leg a step behind, and then, with a screwing movement on the other heel, go on again.
Psychologically based idiosyncracies of gait are usually of a striking nature, quite di?erent from those occuring in any neurological conditions. They tend to draw attention to the patient, and are worse when he or she is observed.... gait
Gene therapy is currently used to treat disorders caused by a fault in a single recessive gene, when the defect can remedied by introducing a normal ALLELE. Treating disorders caused by dominant genes is more complicated. CYSTIC FIBROSIS is an example of a disease caused by a recessive gene, and clinical trials are taking place on the e?ectiveness of using LIPOSOMES to introduce the normal gene into the lungs of someone with the disorder. Trials are also underway to test the e?ectiveness of introducing tumour-suppressing genes into cancer cells to check their spread.
Gene therapy was ?rst used in 1990 to treat an American patient. Eleven European medical research councils (including the UK’s) recommended in 1988 that gene therapy should be restricted to correcting disease or defects, and that it should be limited to somatic cells. Interventions in germ-line cells (the sperm and egg) to e?ect changes that would be inherited, though technically feasible, is not allowed (see CLONING; HUMAN GENOME).... gene therapy
Psychiatrists like to categorise mental illnesses because mental signs and symptoms do occur together in clusters or syndromes, each tending to respond to certain treatments. The idea that illnesses can be diagnosed simply by recognising their symptom patterns may not seem very scienti?c in these days of high technology. For most common mental illnesses, however, this is the only method of diagnosis; whatever is going wrong in the brain is usually too poorly understood and too subtle to show up in laboratory tests or computed tomography scans of the brain. And symptom-based definitions of mental illnesses are, generally, a lot more meaningful than the vague lay term ‘nervous breakdown’, which is used to cover an attack of anything from AGORAPHOBIA to total inability to function.
There is still a lot to learn about the workings of the brain, but psychiatry has developed plenty of practical knowledge about the probable causes of mental illness, ways of relieving symptoms, and ways of aiding recovery. Most experts now believe that mental illnesses generally arise from di?erent combinations of inherited risk and psychological STRESS, sometimes with additional environmental exposure – for example, viruses, drugs or ALCOHOL.
The range of common mental illnesses includes anxiety states, PHOBIA, DEPRESSION, alcohol and drug problems, the EATING DISORDERS anorexia and bulimia nervosa, MANIC DEPRESSION, SCHIZOPHRENIA, DEMENTIA, and a group of problems related to coping with life that psychiatrists call personality disorders.
Of these mental illnesses, dementia is the best understood. It is an irreversible and fatal form of mental deterioration (starting with forgetfulness and eventually leading to severe failure of all the brain’s functions), caused by rapid death of brain cells and consequent brain shrinkage. Schizophrenia is another serious mental illness which disrupts thought-processes, speech, emotions and perception (how the brain handles signals from the ?ve senses). Manic depression, in which prolonged ‘highs’ of extremely elevated mood and overexcitement alternate with abject misery, has similar effects on the mental processes. In both schizophrenia and manic depression the sufferer loses touch with reality, develops unshakeable but completely unrealistic ideas (delusions), and hallucinates (vividly experiences sensations that are not real, e.g. hears voices when there is nobody there). This triad of symptoms is called psychosis and it is what lay people, through fear and lack of understanding, sometimes call lunacy, madness or insanity.
The other mental illnesses mentioned above are sometimes called neuroses. But the term has become derogatory in ordinary lay language; indeed, many people assume that neuroses are mild disorders that only affect weak people who cannot ‘pull themselves together’, while psychoses are always severe. In reality, psychoses can be brief and reversible and neuroses can cause lifelong disability.
However de?ned and categorised, mental illness is a big public-health problem. In the UK, up to one in ?ve women and around one in seven men have had mental illness. About half a million people in Britain suffer from schizophrenia: it is three times commoner than cancer. And at any one time, up to a tenth of the adult population is ill with depression.
Treatment settings Most people with mental-health problems get the help they need from their own family doctor(s), without ever seeing a psychiatrist. General practictitioners in Britain treat nine out of ten recognised mental-health problems and see around 12 million adults with mental illness each year. Even for the one in ten of these patients referred to psychiatrists, general practitioners usually handle those problems that continue or recur.
Psychiatrists, psychiatric nurses, social workers, psychologists, counsellors and therapists often see patients at local doctors’ surgeries and will do home visits if necessary. Community mental-health centres – like general-practice health centres but catering solely for mental-health problems – o?er another short-cut to psychiatric help. The more traditional, and still more common, route to a psychiatrist for many people, however, is from the general practititioner to a hospital outpatient department.
Specialist psychiatric help In many ways, a visit to a psychiatrist is much like any trip to a hospital doctor – and, indeed, psychiatric clinics are often based in the outpatient departments of general hospitals. First appointments with psychiatrists can last an hour or more because the psychiatrist – and sometimes other members of the team such as nurses, doctors in training, and social workers – need to ask lots of questions and record the whole consultation in a set of con?dential case notes.
Psychiatric assessment usually includes an interview and an examination, and is sometimes backed up by a range of tests. The interview begins with the patient’s history – the personal story that explains how and, to some extent, why help is needed now. Mental-health problems almost invariably develop from a mixture of causes – emotional, social, physical and familial – and it helps psychiatrists to know what the people they see are normally like and what kind of lives they have led. These questions may seem unnecessarily intrusive, but they allow psychiatrists to understand patients’ problems and decide on the best way to help them.
The next stage in assessment is the mental-state examination. This is how psychiatrists examine minds, or at least their current state. Mental-state examination entails asking more questions and using careful observation to assess feelings, thoughts and mental symptoms, as well as the way the mind is working (for example, in terms of memory and concentration). During ?rst consultations psychiatrists usually make diagnoses and explain them. The boundary between a life problem that will clear up spontaneously and a mental illness that needs treatment is sometimes quite blurred; one consultation may be enough to put the problem in perspective and help to solve it.
Further assessment in the clinic may be needed, or some additional tests. Simple blood tests can be done in outpatient clinics but other investigations will mean referral to another department, usually on another day.
Further assessment and tests
PSYCHOLOGICAL TESTS Psychologists work in or alongside the psychiatric team, helping in both assessment and treatment. The range of psychological tests studies memory, intelligence, personality, perception and capability for abstract thinking. PHYSICAL TESTS Blood tests and brain scans may be useful to rule out a physical illness causing psychological symptoms. SOCIAL ASSESSMENT Many patients have social diffculties that can be teased out and helped by a psychiatric social worker. ‘Approved social workers’ have special training in the use of the Mental Health Act, the law that authorises compulsory admissions to psychiatric hospitals and compulsory psychiatric treatments. These social workers also know about all the mental-health services o?ered by local councils and voluntary organisations, and can refer clients to them. The role of some social workers has been widened greatly in recent years by the expansion of community care. OCCUPATIONAL THERAPY ASSESSMENT Mental-health problems causing practical disabilities – for instance, inability to work, cook or look after oneself – can be assessed and helped by occupational therapists.
Treatment The aims of psychiatric treatment are to help sufferers shake o?, or at least cope with, symptoms and to gain or regain an acceptable quality of life. A range of psychological and physical treatments is available.
COUNSELLING This is a widely used ‘talking cure’, particularly in general practice. Counsellors listen to their clients, help them to explore feelings, and help them to ?nd personal and practical solutions to their problems. Counsellors do not probe into clients’ pasts or analyse them. PSYCHOTHERAPY This is the best known ‘talking cure’. The term psychotherapy is a generalisation covering many di?erent concepts. They all started, however, with Sigmund Freud (see FREUDIAN THEORY), the father of modern psychotherapy. Freud was a doctor who discovered that, as well as the conscious thoughts that guide our feelings and actions, there are powerful psychological forces of which we are not usually aware. Applying his theories to his patients’ freely expressed thoughts, Freud was able to cure many illnesses, some of which had been presumed completely physical. This was the beginning of individual analytical psychotherapy, or PSYCHOANALYSIS. Although Freud’s principles underpin all subsequent theories about the psyche, many di?erent schools of thought have emerged and in?uenced psychotherapists (see ADLER; JUNGIAN ANALYSIS; PSYCHOTHERAPY). BEHAVIOUR THERAPY This springs from theories of human behaviour, many of which are based on studies of animals. The therapists, mostly psychologists, help people to look at problematic patterns of behaviour and thought, and to change them. Cognitive therapy is very e?ective, particularly in depression and eating disorders. PHYSICAL TREATMENTS The most widely used physical treatments in psychiatry are drugs. Tranquillising and anxiety-reducing BENZODIAZEPINES like diazepam, well known by its trade name of Valium, were prescribed widely in the 1960s and 70s because they seemed an e?ective and safe substitute for barbiturates. Benzodiazepines are, however, addictive and are now recommended only for short-term relief of anxiety that is severe, disabling, or unacceptably distressing. They are also used for short-term treatment of patients drying out from alcohol.
ANTIDEPRESSANT DRUGS like amitriptyline and ?uoxetine are given to lift depressed mood and to relieve the physical symptoms that sometimes occur in depression, such as insomnia and poor appetite. The side-effects of antidepressants are mostly relatively mild, when recommended doses are not exceeded – although one group, the monoamine oxidase inhibitors, can lead to sudden and dangerous high blood pressure if taken with certain foods.
Manic depression virtually always has to be treated with mood-stabilising drugs. Lithium carbonate is used in acute mania to lower mood and stop psychotic symptoms; it can also be used in severe depression. However lithium’s main use is to prevent relapse in manic depression. Long-term unwanted effects may include kidney and thyroid problems, and short-term problems in the nervous system and kidney may occur if the blood concentration of lithium is too high – therefore it must be monitored by regular blood tests. Carbamazepine, a treatment for EPILEPSY, has also been found to stabilise mood, and also necessitates blood tests.
Antipsychotic drugs, also called neuroleptics, and major tranquillisers are the only e?ective treatments for relieving serious mental illnesses with hallucinations and delusions. They are used mainly in schizophrenia and include the short-acting drugs chlorpromazine and clozapine as well as the long-lasting injections given once every few weeks like ?uphenazine decanoate. In the long term, however, some of the older antipsychotic drugs can cause a brain problem called TARDIVE DYSKINESIA that affects control of movement and is not always reversible. And the antipsychotic drugs’ short-term side-effects such as shaking and sti?ness sometimes have to be counteracted by other drugs called anticholinergic drugs such as procyclidine and benzhexol. Newer antipsychotic drugs such as clozapine do not cause tardive dyskinesia, but clozapine cannot be given as a long-lasting injection and its concentration in the body has to be monitored by regular blood tests to avoid toxicity. OTHER PHYSICAL TREATMENTS The other two physical treatments used in psychiatry are particularly controversial: electroconvulsive therapy (ECT) and psychosurgery. In ECT, which can be life-saving for patients who have severe life-threatening depression, a small electric current is passed through the brain to induce a ?t or seizure. Before the treatment the patient is anaesthetised and given a muscle-relaxing injection that reduces the magnitude of the ?t to a slight twitching or shaking. Scientists do not really understand how ECT works, but it does, for carefully selected patients. Psychosurgery – operating on the brain to alleviate psychiatric illness or di?cult personality traits – is extremely uncommon these days. Stereo-tactic surgery, in which small cuts are made in speci?c brain ?bres under X-ray guidance, has super-seded the more generalised lobotomies of old. The Mental Health Act 1983 ensures that psychosurgery is performed only when the patient has given fully informed consent and a second medical opinion has agreed that it is necessary. For all other psychiatric treatments (except another rare treatment, hormone implantation for reducing the sex drive of sex o?enders), either consent or a second opinion is needed – not both. TREATMENT IN HOSPITAL Psychiatric wards do not look like medical or surgical wards and sta? may not wear uniforms. Patients do not need to be in their beds during the day, so the beds are in separate dormitories. The main part of most wards is a living space with a day room, an activity and television room, quiet rooms, a dining room, and a kitchen. Ward life usually has a certain routine. The day often starts with a community meeting at which patients and nurses discuss issues that affect the whole ward. Patients may go to the occupational therapy department during the day, but there may also be some therapy groups on the ward, such as relaxation training. Patients’ symptoms and problems are assessed continuously during a stay in hospital. When patients seem well enough they are allowed home for trial periods; then discharge can be arranged. Patients are usually followed up in the outpatient clinic at least once.
TREATING PATIENTS WITH ACUTE PSYCHIATRIC ILLNESS Psychiatric emergencies – patients with acute psychiatric illness – may develop from psychological, physical, or practical crises. Any of these crises may need quick professional intervention. Relatives and friends often have to get this urgent help because the sufferer is not ?t enough to do it or, if psychotic, does not recognise the need. First, they should ring the person’s general practitioner. If the general practitioner is not available and help is needed very urgently, relatives or friends should phone the local social-services department and ask for the duty social worker (on 24-hour call). In a dire emergency, the police will know what to do.
Any disturbed adult who threatens his or her own or others’ health and safety and refuses psychiatric help may be moved and detained by law. The Mental Health Act of 1983 authorises emergency assessment and treatment of any person with apparent psychiatric problems that ful?l these criteria.
Although admission to hospital may be the best solution, there are other ways that psychiatric services can respond to emergencies. In some districts there are ‘crisis intervention’ teams of psychiatrists, nurses, and social workers who can visit patients urgently at home (at a GP’s request) and, sometimes, avert unnecessary admission. And research has shown that home treatment for a range of acute psychiatric problems can be e?ective.
LONG-TERM TREATMENT AND COMMUNITY CARE Long-term treatment is often provided by GPs with support and guidance from psychiatric teams. That is ?ne for people whose problems allow them to look after themselves, and for those with plenty of support from family and friends. But some people need much more intensive long-term treatment and many need help with running their daily lives.
Since the 1950s, successive governments have closed the old psychiatric hospitals and have tried to provide as much care as possible outside hospital – in ‘the community’. Community care is e?ective as long as everyone who needs inpatient care, or residential care, can have it. But demand exceeds supply. Research has shown that some homeless people have long-term mental illnesses and have somehow lost touch with psychiatric services. Many more have developed more general long-term health problems, particularly related to alcohol, without ever getting help.
The NHS and Community Care Act 1990, in force since 1993, established a new breed of professionals called care managers to assess people whose long-term illnesses and disabilities make them unable to cope completely independently with life. Care managers are given budgets by local councils to assess people’s needs and to arrange for them tailor-made packages of care, including services like home helps and day centres. But co-ordination between health and social services has sometimes failed – and resources are limited – and the government decided in 1997 to tighten up arrangements and pool community-care budgets.
Since 1992 psychiatrists have had to ensure that people with severe mental illnesses have full programmes of care set up before discharge from hospital, to be overseen by named key workers. And since 1996 psychiatrists have used a new power called Supervised Discharge to ensure that the most vulnerable patients cannot lose touch with mental-health services. There is not, however, any law that allows compulsory treatment in the community.
There is ample evidence that community care can work and that it need not cost more than hospital care. Critics argue, however, that even one tragedy resulting from inadequate care, perhaps a suicide or even a homicide, should reverse the march to community care. And, according to the National Schizophrenia Fellowship, many of the 10–15 homicides a year carried out by people with severe mental illnesses result from inadequate community care.
Further information can be obtained from the Mental Health Act Commission, and from MIND, the National Association for Mental Health. MIND also acts as a campaigning and advice organisation on all aspects of mental health.... mental illness
Cramp Painful spasm of a muscle usually caused by excessive and prolonged contraction of the muscle ?bres. Cramps are common, especially among sportsmen and women, normally lasting a short time. The condition usually occurs during or immediately following exercise as a result of a build-up of LACTIC ACID and other chemical by-products in the muscles
– caused by the muscular e?orts. Cramps may occur more frequently, especially at night, in people with poor circulation, when the blood is unable to remove the lactic acid from the muscles quickly enough.
Repetitive movements such as writing (writer’s cramp) or operating a keyboard can cause cramp. Resting muscles may suffer cramp if a person sits or lies in an awkward position which limits local blood supply to them. Profuse sweating as a result of fever or hot weather can also cause cramp in resting muscle, because the victim has lost sodium salts in the sweat; this disturbs the biochemical balance in muscle tissue.
Treatment is to massage and stretch the affected muscle – for example, cramp in the calf muscle may be relieved by pulling the toes on the affected leg towards the knee. Persistent night cramps sometimes respond to treatment with a drug containing CALCIUM or QUININE. If cramp persists for an hour or more, the person should seek medical advice, as there may be a serious cause such as a blood clot impeding the blood supply to the area affected.
Dystrophy See myopathy below.
In?ammation (myositis) of various types may occur. As the result of injury, an ABSCESS may develop, although wounds affecting muscle generally heal well. A growth due to SYPHILIS, known as a gumma, sometimes forms a hard, almost painless swelling in a muscle. Rheumatism is a vague term traditionally used to de?ne intermittent and often migratory discomfort, sti?ness or pain in muscles and joints with no obvious cause. The most common form of myositis is the result of immunological damage as a result of autoimmune disease. Because it affects many muscles it is called POLYMYOSITIS.
Myasthenia (see MYASTHENIA GRAVIS) is muscle weakness due to a defect of neuromuscular conduction.
Myopathy is a term applied to an acquired or developmental defect in certain muscles. It is not a neurological disease, and should be distinguished from neuropathic conditions (see NEUROPATHY) such as MOTOR NEURONE DISEASE (MND), which tend to affect the distal limb muscles. The main subdivisions are genetically determined, congenital, metabolic, drug-induced, and myopathy (often in?ammatory) secondary to a distant carcinoma. Progressive muscular dystrophy is characterised by symmetrical wasting and weakness, the muscle ?bres being largely replaced by fatty and ?brous tissue, with no sensory loss. Inheritance may take several forms, thus affecting the sex and age of victims.
The commonest type is DUCHENNE MUSCULAR DYSTROPHY, which is inherited as a sex-linked disorder. It nearly always occurs in boys.
Symptoms There are three chief types of myopathy. The commonest, known as pseudohypertrophic muscular dystrophy, affects particularly the upper part of the lower limbs of children. The muscles of the buttocks, thighs and calves seem excessively well developed, but nevertheless the child is clumsy, weak on his legs, and has di?culty in picking himself up when he falls. In another form of the disease, which begins a little later, as a rule at about the age of 14, the muscles of the upper arm are ?rst affected, and those of the spine and lower limbs become weak later on. In a third type, which begins at about this age, the muscles of the face, along with certain of the shoulder and upper arm muscles, show the ?rst signs of wasting. All the forms have this in common: that the affected muscles grow weaker until their power to contract is quite lost. In the ?rst form, the patients seldom reach the age of 20, falling victims to some disease which, to ordinary people, would not be serious. In the other forms the wasting, after progressing to a certain extent, often remains stationary for the rest of life. Myopathy may also be acquired when it is the result of disease such as thyrotoxicosis (see under THYROID GLAND, DISEASES OF), osteomalacia (see under BONE, DISORDERS OF) and CUSHING’S DISEASE, and the myopathy resolves when the primary disease is treated.
Treatment Some myopathies may be the result of in?ammation or arise from an endocrine or metabolic abnormality. Treatment of these is the treatment of the cause, with supportive physiotherapy and any necessary physical aids while the patient is recovering. Treatment for the hereditary myopathies is supportive since, at present, there is no cure – although developments in gene research raise the possibility of future treatment. Physiotherapy, physical aids, counselling and support groups may all be helpful in caring for these patients.
The education and management of these children raise many diffculties. Much help in dealing with these problems can be obtained from Muscular Dystrophy Campaign.
Myositis ossi?cans, or deposition of bone in muscles, may be congenital or acquired. The congenital form, which is rare, ?rst manifests itself as painful swellings in the muscles. These gradually harden and extend until the child is encased in a rigid sheet. There is no e?ective treatment and the outcome is fatal.
The acquired form is a result of a direct blow on muscle, most commonly on the front of the thigh. The condition should be suspected whenever there is severe pain and swelling following a direct blow over muscle. The diagnosis is con?rmed by hardening of the swelling. Treatment consists of short-wave DIATHERMY with gentle active movements. Recovery is usually complete.
Pain, quite apart from any in?ammation or injury, may be experienced on exertion. This type of pain, known as MYALGIA, tends to occur in un?t individuals and is relieved by rest and physiotherapy.
Parasites sometimes lodge in the muscles, the most common being Trichinella spiralis, producing the disease known as TRICHINOSIS (trichiniasis).
Rupture of a muscle may occur, without any external wound, as the result of a spasmodic e?ort. It may tear the muscle right across – as sometimes happens to the feeble plantaris muscle in running and leaping – or part of the muscle may be driven through its ?brous envelope, forming a HERNIA of the muscle. The severe pain experienced in many cases of LUMBAGO is due to tearing of one of the muscles in the back. These conditions are usually relieved by rest and massage. Partial muscle tears, such as occur in sport, require more energetic treatment: in the early stages this consists of the application of an ice or cold-water pack, ?rm compression, elevation of the affected limb, rest for a day or so and then gradual mobilisation (see SPORTS MEDICINE).
Tumours occur occasionally, the most common being ?broid, fatty, and sarcomatous growths.
Wasting of muscles sometimes occurs as a symptom of disease in other organs: for example, damage to the nervous system, as in poliomyelitis or in the disease known as progressive muscular atrophy. (See PARALYSIS.)... muscles, disorders of
Half of a person’s genes come from the father and half from the mother, and this mix determines the o?spring’s characteristics. (A quarter of a person’s genes come from each of the four grandparents.) Genes ful?l their functions by controlling the manufacture of particular proteins in the body. The power that genes have to in?uence the body’s characteristics varies: broadly, some are dominant (more powerful); others are recessive (less powerful) whose functions are overridden by the former. Genes are also liable to change or mutate, giving the potential for the characteristics of individuals or their o?spring to be altered. (See GENETIC CODE; GENETIC DISORDERS; GENE THERAPY; HUMAN GENOME.)... genes
Already genetic engineering is contributing to easing the problems of diagnosis. DNA analysis and production of MONOCLONAL ANTIBODIES are other applications of genetic engineering. Genetic engineering has signi?cantly contributed to horticulture and agriculture with certain characteristics of one organism or variant of a species being transfected (a method of gene transfer) into another. This has given rise to higher-yield crops and to alteration in colouring and size in produce. Genetic engineering is also contributing to our knowledge of how human genes function, as these can be transfected into mice and other animals which can then act as models for genetic therapy. Studying the effects of inherited mutations derived from human DNA in these animal models is thus a very important and much faster way of learning about human disease.
Genetic engineering is a scienti?c procedure that could have profound implications for the human race. Manipulating heredity would be an unwelcome activity under the control of maverick scientists, politicians or others in positions of power.... genetic engineering
Genetic screening is proving to be a controversial subject. Arguments are developing over whether the results of such screenings should be made available to employers and insurance companies – a move that could have adverse consequences for some individuals with potentially harmful genetic make-ups. (See GENES; GENETIC DISORDERS.)... genetic screening
It is also the name given to the treatment of disease by the arti?cial production of FEVER. This can be achieved by various methods, such as radiation heat cabinets boosted with radio frequency (RF); immersion in a hot wax bath; heated suits or blankets; techniques using electromagnetic waves (e.g. RF, MICROWAVES); and ULTRASOUND of appropriate frequencies. Hyperthermia is sometimes of help as an adjunct to surgery, CHEMOTHERAPY, or RADIOTHERAPY in the treatment of cancer.... hyperthermia
Treatment Hypochondriacal patients may also develop physical illness, and any new symptoms must always be carefully evaluated. In most patients the condition is secondary, and treatment should be directed to the underlying depression or schizophrenia. In the rare cases of primary hypochondriasis, supportive measures are the mainstay of treatment.... hypochondriasis
In recent years, however, the position has been altered by the introduction of the so-called fertility drugs, such as CLOMIPHENE, and human menopausal gonadotrophin which, through the medium of the PITUITARY GLAND, stimulate the production of ova (see OVUM). Their wide use in the treatment of INFERTILITY has resulted in an increase in the number of multiple births, a recognised hazard of giving too large a dose.
Twins may be binovular or uniovular. Binovular, or fraternal, twins are the result of the mother’s releasing two ova within a few days of each other and both being fertilised by separate spermatozoa (see SPERMATOZOON). They both develop separately in the mother’s womb and are no more alike than is usual with members of the same family. They are three times as common as uniovular, or identical, twins, who are developed from a single ovum fertilised by a single spermatozoon, but which has split early in development. This is why they are usually so remarkably alike in looks and mental characteristics. Unlike binovular twins, who may be of the same or di?erent sex, they are always of the same sex.
So far as fraternal, or binovular, twins are concerned, multiple pregnancy may be an inherited tendency; it certainly occurs more often in certain families, but this may be partly due to chance. A woman who has already given birth to twins is ten times more likely to have another multiple pregnancy than one who has not previously had twins. The statistical chance of a third pair of twins is 1:512,000. Identical twins do not run in families.
The relative proportion of twins of each type varies in di?erent races. Identical twins have much the same frequency all over the world: around 3 per 1,000 maternities. Fraternal twins are rare in Mongolian races: less than 3 per 1,000 maternities. In Caucasians they occur two or three times as often as identical twins: between 7 (Spain and Portugal) and 10 (Czech and Slovak Republics and Greece) per 1,000 maternities. They are more common in Afro-Caribbeans, reaching 30 per 1,000 maternities in certain West African populations.
Rarely, uniovular twins may not develop as separate individuals, being physically joined in some way. They are called conjoined or (traditionally) Siamese twins. Depending on the extent of common structures shared by the infants – this ranges from a common umbilical cord to twins with conjoined heads or a common liver – the infants may be successfully separated by surgery. (See CONJOINED TWINS.)
Parents of twins, triplets, etc. can obtain advice and help from the Twins and Multiple Births Association (TAMBA).... multiple births
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