An alternative spelling for ciclosporin.
Nutritional Profile Energy value (calories per serving): Low Protein: Low Fat: Low Saturated fat: Low Cholesterol: None Carbohydrates: High Fiber: Moderate Sodium: Low Major vitamin contribution: Vitamin A, vitamin C Major mineral contribution: Potassium
About the Nutrients in This Food Grapefruit and ugli fruit (a cross between the grapefruit and the tangerine) have moderate amounts of dietary fiber and, like all citrus fruits, are most prized for their vitamin C. Pink or red grapefruits have moderate amounts of vitamin A. One-half medium (four-inch diameter) pink grapefruit has 1.4 g dietary fiber, 1,187 IU vitamin A (51 percent of the R DA for a woman, 40 percent of the R DA for a man), and 44 mg vitamin C (59 percent of the R DA for a woman, 49 percent of the R DA for a man). One half medium (3.75-inch diameter) white grapefruit has 1.3 g dietary fiber, 39 IU vitamin A (2 percent of the R DA for a woman, 1 percent of the R DA for a man), and 39 mg vitamin C (52 percent of the R DA for a woman, 43 percent of the R DA for a man). Pink and red grapefruits also contain lycopene, a red carotenoid (plant pigment), a strong antioxidant that appears to lower the risk of cancer of the prostate. The richest source of lycopene is cooked tom atoes.
The Most Nutritious Way to Serve This Food Fresh fruit or fresh-squeezed juice.
Buying This Food Look for: Firm fruit that is heavy for its size, which means that it will be juicy. The skin should be thin, smooth, and fine-grained. Most grapefruit have yellow skin that, depending on the variety, may be tinged with red or green. In fact, a slight greenish tint may mean that the grapefruit is high in sugar. Ugli fruit, which looks like misshapen, splotched grapefruit, is yellow with green patches and bumpy skin. Avoid: Grapefruit or ugli fruit with puff y skin or those that feel light for their size; the flesh inside is probably dry and juiceless.
Storing This Food Store grapefruit either at room temperature (for a few days) or in the refrigerator. Refrigerate grapefruit juice in a tightly closed glass bottle with very little air space at the top. As you use up the juice, transfer it to a smaller bottle, again with very little air space at the top. The aim is to prevent the juice from coming into contact with oxygen, which destroys vitamin C. (Most plastic juice bottles are oxygen-permeable.) Properly stored and protected from oxygen, fresh grapefruit juice can hold its vitamin C for several weeks.
Preparing This Food Grapefruit are most flavorful at room temperature, which liberates the aromatic molecules that give them their characteristic scent and taste. Before cutting into the grapefruit, rinse it under cool running water to flush debris off the peel. To section grapefruit, cut a slice from the top, then cut off the peel in strips—starting at the top and going down—or peel it in a spiral fashion. You can remove the bitter white membrane, but some of the vitamin C will go with it. Finally, slice the sections apart. Or you can simply cut the grapefruit in half and scoop out the sections with a curved, serrated grapefruit knife.
What Happens When You Cook This Food Broiling a half grapefruit or poaching grapefruit sections reduces the fruit’s supply of vitamin C, which is heat-sensitive.
How Other Kinds of Processing Affect This Food Commercially prepared juices. How well a commercially prepared juice retains its vitamin C depends on how it is prepared, stored, and packaged. Commercial flash-freezing preserves as much as 95 percent of the vitamin C in fresh grapefruit juices. Canned juice stored in the refrigerator may lose only 2 percent of its vitamin C in three months. Prepared, pasteurized “fresh” juices lose vitamin C because they are sold in plastic bottles or waxed-paper cartons that let oxygen in. Commercially prepared juices are pasteurized to stop the natural enzyme action that would otherwise turn sugars to alcohols. Pasteurization also protects juices from potentially harmful bacterial and mold contamination. Following several deaths attributed to unpas- teurized apple juices containing E. coli O157:H7, the FDA ruled that all fruit and vegetable juices must carry a warning label telling you whether the juice has been pasteurized. Around the year 2000, all juices must be processed to remove or inactivate harmful bacteria.
Medical Uses and/or Benefits Antiscorbutic. All citrus fruits are superb sources of vitamin C, the vitamin that prevents or cures scurvy, the vitamin C-deficiency disease. Increased absorption of supplemental or dietary iron. If you eat foods rich in vitamin C along with iron supplements or foods rich in iron, the vitamin C will enhance your body’s ability to absorb the iron. Wound healing. Your body needs vitamin C in order to convert the amino acid proline into hydroxyproline, an essential ingredient in collagen, the protein needed to form skin, ten- dons, and bones. As a result people with scurvy do not heal quickly, a condition that can be remedied with vitamin C, which cures the scurvy and speeds healing. Whether taking extra vitamin C speeds healing in healthy people remains to be proved. Possible inhibition of virus that causes chronic hepatitis C infection. In Januar y 2008, research- ers at Massachusetts General Hospital Center for Engineering in Medicine (Boston) published a report in the medical journal Hepatology detailing the effect of naringenin, a compound in grapefruit, on the behavior of hepatitis viruses in liver cells. In laborator y studies, naringenin appeared to inhibit the ability of the virus to multiply and/or pass out from the liver cells. To date, there are no studies detailing the effect of naringenin in human beings with hepatitis C.
Adverse Effects Associated with This Food Contact dermatitis. The essential oils in the peel of citrus fruits may cause skin irritation in sensitive people.
Food/Drug Interactions Aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, naproxen and others. Taking aspirin or NSAIDs with acidic foods such as grapefruit may intensif y the drug’s ability to irritate your stomach and cause gastric bleeding. Antihistamines, anticoagulants, benzodiazepines (tranquilizers or sleep medications), calcium channel blockers (blood pressure medication), cyclosporine (immunosuppressant drug used in organ transplants), theophylline (asthma drug). Drinking grapefruit juice with a wide variety of drugs ranging from antihistamines to blood pressure medication appears to reduce the amount of the drug your body metabolizes and eliminates. The “grapefruit effect” was first identified among people taking the antihypertensive drugs felodipine (Plendil) and nifedip- ine (Adalat, Procardia). It is not yet known for certain exactly what the active substance in the juice is. One possibility, however, is bergamottin, a naturally occurring chemical in grapefruit juice known to inactivate cytochrome P450 3A4, a digestive enzyme needed to convert many drugs to water-soluble substances you can flush out of your body. Without an effective supply of cytochrome P450 3A4, the amount of a drug circulating in your body may rise to dangerous levels. Reported side effects include lower blood pressure, increased heart rate, headache, flushing, and lightheadedness. Some Drugs Known to Interact with Grapefruit Juice* Drug Class Generic (Brand name) Antianxiety drug Diazepam ( Valium) Antiarrhythmics Amiodarone (Cordarone) Blood-pressure drugs Felodipine (Plendil), nicardipine (Cardene), nimodipine (Nimotop), nisoldipine (Sular), verapamil ( Verelan) Cholesterol-lowering drugs Atorvastatin (Lipitor), lovastatin (Mevacor), simvastatin (Zocor), simvastatin/ezetimibe ( Vytorin) Immune Suppressants Cyclosporine (Neoral), tacrolimus (Prograf ) Impotence Drug Sildenafil ( Viagra) Pain Medication Methadone (Dolophine, Methadose) * This list may grow as new research appears.... grapefruit
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
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