Osmosis Health Dictionary

Osmosis: From 3 Different Sources


The passage of a solvent from a weaker solution to a more concentrated one through a semipermeable membrane.

All body cells are surrounded by such membranes, which allow water, salts, simple sugars (such as glucose), and amino acids (but not proteins) to pass through.

Therefore, osmosis plays an important part in regulating the distribution of water and other substances in body tissues.

Health Source: BMA Medical Dictionary
Author: The British Medical Association
The passage of ?uids through a semipermeable membrane which separates them, so as to become mixed with one another. Osmotic pressure is a term applied to the strength of the tendency which a ?uid shows to do this, and depends largely upon the amount of solid which it holds in solution.
Health Source: Medical Dictionary
Author: Health Dictionary
n. the passage of a solvent from a less concentrated to a more concentrated solution through a *semipermeable membrane. This tends to equalize the concentrations of the two solutions. In living organisms the solvent is water and cell membranes function as semipermeable membranes, and the process of osmosis plays an important role in controlling the distribution of water. The osmotic pressure of a solution is the pressure by which water is drawn into it through the semipermeable membrane; the more concentrated the solution (i.e. the more solute molecules it contains), the greater its osmotic pressure. —osmotic adj.
Health Source: Oxford | Concise Colour Medical Dictionary
Author: Jonathan Law, Elizabeth Martin

Isotonic

A term applied to solutions which have the same power of di?usion as one another. An isotonic solution used in medicine is one which can be mixed with body ?uids without causing any disturbance. An isotonic saline solution for injection into the blood, so that it may possess the same osmotic pressure (see OSMOSIS) as the blood SERUM, is one of 0·9 per cent strength – that is, containing 9 grams of sodium chloride to 1 litre of water. This is also known as normal or physiological salt solution. An isotonic solution of bicarbonate of soda for injection into the blood is one of 1·35 per cent strength in water. An isotonic solution of glucose for injection into the blood is one of 5 per cent strength in water.

Solutions which are weaker, or stronger, than the ?uids of the body with which they are intended to be mixed are known as hypotonic and hypertonic, respectively.... isotonic

Hypertonic

(1) Referring to one solution which has a greater osmotic pressure (see OSMOSIS) than another. Physiologically it is used to describe solutions which have a greater osmotic pressure than body ?uids.

(2) Muscles with abnormally increased tone

(e.g. following a STROKE).... hypertonic

Hypotonic

(1) Referring to a solution which has a lower osmotic pressure (see OSMOSIS) than another. Physiologically it describes a solution with a lower osmotic pressure than body ?uids.

(2) Muscles with abnormally reduced tone.... hypotonic

Beef

Nutritional Profile Energy value (calories per serving): Moderate Protein: High Fat: Moderate Saturated fat: High Cholesterol: Moderate Carbohydrates: None Fiber: None Sodium: Low Major vitamin contribution: B vitamins Major mineral contribution: Iron, phosphorus, zinc

About the Nutrients in This Food Like fish, pork, poultry, milk, and eggs, beef has high-quality proteins, with sufficient amounts of all the essential amino acids. Beef fat is slightly more highly saturated than pork fat, but less saturated than lamb fat. All have about the same amount of cholesterol per serving. Beef is an excellent source of B vitamins, including niacin, vitamin B6, and vitamin B12, which is found only in animal foods. Lean beef pro- vides heme iron, the organic iron that is about five times more useful to the body than nonheme iron, the inorganic form of iron found in plant foods. Beef is also an excellent source of zinc. One four-ounce serving of lean broiled sirloin steak has nine grams fat (3.5 g saturated fat), 101 mg cholesterol, 34 g protein, and 3.81 mg iron (21 percent of the R DA for a woman, 46 percent of the R DA for a man). One four-ounce serving of lean roast beef has 16 g fat (6.6 g saturated fat), 92 mg cholesterol, and 2.96 mg iron (16 percent of the R DA for a woman, 37 percent of the R DA for a man).

The Most Nutritious Way to Serve This Food With a food rich in vitamin C. Ascorbic acid increases the absorption of iron from meat. * These values apply to lean cooked beef.

Diets That May Restrict or Exclude This Food Controlled-fat, low-cholesterol diet Low-protein diet (for some forms of kidney disease)

Buying This Food Look for: Fresh, red beef. The fat should be white, not yellow. Choose lean cuts of beef with as little internal marbling (streaks of fat) as possible. The leanest cuts are flank steak and round steak; rib steaks, brisket, and chuck have the most fat. USDA grading, which is determined by the maturity of the animal and marbling in meat, is also a guide to fat content. U.S. prime has more marbling than U.S. choice, which has more marbling than U.S. good. All are equally nutritious; the difference is how tender they are, which depends on how much fat is present. Choose the cut of meat that is right for your recipe. Generally, the cuts from the cen- ter of the animal’s back—the rib, the T-Bone, the porterhouse steaks—are the most tender. They can be cooked by dry heat—broiling, roasting, pan-frying. Cuts from around the legs, the underbelly, and the neck—the shank, the brisket, the round—contain muscles used for movement. They must be tenderized by stewing or boiling, the long, moist cooking methods that break down the connective tissue that makes meat tough.

Storing This Food Refrigerate raw beef immediately, carefully wrapped to prevent its drippings from contami- nating other foods. Refrigeration prolongs the freshness of beef by slowing the natural multi- plication of bacteria on the meat surface. Unchecked, these bacteria will convert proteins and other substances on the surface of the meat to a slimy film and change meat’s sulfur-contain- ing amino acids methionine and cystine into smelly chemicals called mercaptans. When the mercaptans combine with myoglobin, they produce the greenish pigment that gives spoiled meat its characteristic unpleasant appearance. Fresh ground beef, with many surfaces where bacteria can live, should be used within 24 to 48 hours. Other cuts of beef may stay fresh in the refrigerator for three to five days.

Preparing This Food Trim the beef carefully. By judiciously cutting away all visible fat you can significantly reduce the amount of fat and cholesterol in each serving. When you are done, clean all utensils thoroughly with soap and hot water. Wash your cutting board, wood or plastic, with hot water, soap, and a bleach-and-water solution. For ultimate safety in preventing the transfer of microorganisms from the raw meat to other foods, keep one cutting board exclusively for raw meats, fish, and poultry, and a second one for everything else. Finally, don’t forget to wash your hands.

What Happens When You Cook This Food Cooking changes the appearance and flavor of beef, alters nutritional value, makes it safer, and extends its shelf life. Browning meat after you cook it does not “seal in the juices,” but it does change the fla- vor by caramelizing sugars on the surface. Because beef’s only sugars are the small amounts of glycogen in the muscles, we add sugars in marinades or basting liquids that may also con- tain acids (vinegar, lemon juice, wine) to break down muscle fibers and tenderize the meat. (Browning has one minor nutritional drawback. It breaks amino acids on the surface of the meat into smaller compounds that are no longer useful proteins.) When beef is cooked, it loses water and shrinks. Its pigments, which combine with oxygen, are denatured (broken into fragments) by the heat and turn brown, the natural color of well-done meat. At the same time, the fats in the beef are oxidized. Oxidized fats, whether formed in cooking or when the cooked meat is stored in the refrigerator, give cooked meat a character- istic warmed-over flavor. Cooking and storing meat under a blanket of antioxidants—catsup or a gravy made of tomatoes, peppers, and other vitamin C-rich vegetables—reduces the oxidation of fats and the intensity of warmed-over flavor. Meat reheated in a microwave oven also has less warmed-over flavor. An obvious nutritional benefit of cooking is the fact that heat lowers the fat content of beef by liquif ying the fat so it can run off the meat. One concrete example of how well this works comes from a comparison of the fat content in regular and extra-lean ground beef. According to research at the University of Missouri in 1985, both kinds of beef lose mass when cooked, but the lean beef loses water and the regular beef loses fat and cholesterol. Thus, while regular raw ground beef has about three times as much fat (by weight) as raw ground extra-lean beef, their fat varies by only 5 percent after broiling. To reduce the amount of fat in ground beef, heat the beef in a pan until it browns. Then put the beef in a colander, and pour one cup of warm water over the beef. Repeat with a second cup of warm water to rinse away fat melted by heating the beef. Use the ground beef in sauce and other dishes that do not require it to hold together. Finally, cooking makes beef safer by killing Salmonella and other organisms in the meat. As a result, cooking also serves as a natural preservative. According to the USDA, large pieces of fresh beef can be refrigerated for two or three days, then cooked and held safely for another day or two because the heat of cooking has reduced the number of bacteria on the surface of the meat and temporarily interrupted the natural cycle of deterioration.

How Other Kinds of Processing Affect This Food Aging. Hanging fresh meat exposed to the air, in a refrigerated room, reduces the moisture content and shrinks the meat slightly. As the meat ages enzymes break down muscle pro- teins, “tenderizing” the beef. Canning. Canned beef does not develop a warmed-over flavor because the high tempera- tures in canning food and the long cooking process alter proteins in the meat so that they act as antioxidants. Once the can is open, however, the meat should be protected from oxygen that will change the flavor of the beef. Curing. Salt-curing preserves meat through osmosis, the physical reaction in which liquids flow across a membrane, such as the wall of a cell, from a less dense to a more dense solution. The salt or sugar used in curing dissolves in the liquid on the surface of the meat to make a solution that is more dense than the liquid inside the cells of the meat. Water flows out of the meat and out of the cells of any microorganisms living on the meat, killing the microor- ganisms and protecting the meat from bacterial damage. Salt-cured meat is much higher in sodium than fresh meat. Freezing. When you freeze beef, the water inside its cells freezes into sharp ice crystals that can puncture cell membranes. When the beef thaws, moisture (and some of the B vitamins) will leak out through these torn cell walls. The loss of moisture is irreversible, but some of the vitamins can be saved by using the drippings when the meat is cooked. Freezing may also cause freezer burn—dry spots left when moisture evaporates from the surface of the meat. Waxed freezer paper is designed specifically to hold the moisture in meat; plastic wrap and aluminum foil are less effective. NOTE : Commercially prepared beef, which is frozen very quickly at very low temperatures, is less likely to show changes in texture. Irradiation. Irradiation makes meat safer by exposing it to gamma rays, the kind of high- energy ionizing radiation that kills living cells, including bacteria. Irradiation does not change the way meat looks, feels or tastes, or make the food radioactive, but it does alter the structure of some naturally occurring chemicals in beef, breaking molecules apart to form new com- pounds called radiolytic products (R P). About 90 percent of R Ps are also found in nonirradiated foods. The rest, called unique radiolytic products (UR P), are found only in irradiated foods. There is currently no evidence to suggest that UR Ps are harmful; irradiation is an approved technique in more than 37 countries around the world, including the United States. Smoking. Hanging cured or salted meat over an open fire slowly dries the meat, kills micro- organisms on its surface, and gives the meat a rich, “smoky” flavor that varies with the wood used in the fire. Meats smoked over an open fire are exposed to carcinogenic chemicals in the smoke, including a-benzopyrene. Meats treated with “artificial smoke flavoring” are not, since the flavoring is commercially treated to remove tar and a-benzopyrene.

Medical Uses and/or Benefits Treating and/or preventing iron deficiency. Without meat in the diet, it is virtually impossible for an adult woman to meet her iron requirement without supplements. One cooked 3.5- ounce hamburger provides about 2.9 mg iron, 16 percent of the R DA for an adult woman of childbearing age. Possible anti-diabetes activity. CLA may also prevent type 2 diabetes, also called adult-onset diabetes, a non-insulin-dependent form of the disease. At Purdue University, rats bred to develop diabetes spontaneously between eight and 10 weeks of age stayed healthy when given CLA supplements.

Adverse Effects Associated with This Food Increased risk of heart disease. Like other foods from animals, beef contains cholesterol and saturated fats that increase the amount of cholesterol circulating in your blood, raising your risk of heart disease. To reduce the risk of heart disease, the National Cholesterol Education Project recommends following the Step I and Step II diets. The Step I diet provides no more than 30 percent of total daily calories from fat, no more than 10 percent of total daily calories from saturated fat, and no more than 300 mg of cholesterol per day. It is designed for healthy people whose cholesterol is in the range of 200 –239 mg/dL. The Step II diet provides 25– 35 percent of total calories from fat, less than 7 percent of total calories from saturated fat, up to 10 percent of total calories from polyunsaturated fat, up to 20 percent of total calories from monounsaturated fat, and less than 300 mg cho- lesterol per day. This stricter regimen is designed for people who have one or more of the following conditions: •  Existing cardiovascular disease •  High levels of low-density lipoproteins (LDLs, or “bad” cholesterol) or low levels of high-density lipoproteins (HDLs, or “good” cholesterol) •  Obesity •  Type 1 diabetes (insulin-dependent diabetes, or diabetes mellitus) •  Metabolic syndrome, a.k.a. insulin resistance syndrome, a cluster of risk fac- tors that includes type 2 diabetes (non-insulin-dependent diabetes) Increased risk of some cancers. According the American Institute for Cancer Research, a diet high in red meat (beef, lamb, pork) increases the risk of developing colorectal cancer by 15 percent for every 1.5 ounces over 18 ounces consumed per week. In 2007, the National Can- cer Institute released data from a survey of 500,000 people, ages 50 to 71, who participated in an eight-year A AR P diet and health study identif ying a higher risk of developing cancer of the esophagus, liver, lung, and pancreas among people eating large amounts of red meats and processed meats. Food-borne illness. Improperly cooked meat contaminated with E. coli O157:H7 has been linked to a number of fatalities in several parts of the United States. In addition, meats con- taminated with other bacteria, viruses, or parasites pose special problems for people with a weakened immune system: the very young, the very old, cancer chemotherapy patients, and people with HIV. Cooking meat to an internal temperature of 140°F should destroy Salmo- nella and Campylobacter jejuni; 165°F, the E. coli organism; and 212°F, Listeria monocytogenes. Antibiotic sensitivity. Cattle in the United States are routinely given antibiotics to protect them from infection. By law, the antibiotic treatment must stop three days to several weeks before the animal is slaughtered. Theoretically, the beef should then be free of antibiotic residues, but some people who are sensitive to penicillin or tetracycline may have an allergic reaction to the meat, although this is rare. Antibiotic-resistant Salmonella and toxoplasmosis. Cattle treated with antibiotics may pro- duce meat contaminated with antibiotic-resistant strains of Salmonella, and all raw beef may harbor ordinary Salmonella as well as T. gondii, the parasite that causes toxoplasmosis. Toxoplasmosis is particularly hazardous for pregnant women. It can be passed on to the fetus and may trigger a series of birth defects including blindness and mental retardation. Both Salmonella and the T. gondii can be eliminated by cooking meat thoroughly and washing all utensils, cutting boards, and counters as well as your hands with hot soapy water before touching any other food. Decline in kidney function. Proteins are nitrogen compounds. When metabolized, they yield ammonia, which is excreted through the kidneys. In laborator y animals, a sustained high-protein diet increases the flow of blood through the kidneys, accelerating the natural age-related decline in kidney function. Some experts suggest that this may also occur in human beings.

Food/Drug Interactions Tetracycline antibiotics (demeclocycline [Declomycin], doxycycline [ Vibtamycin], methacycline [Rondomycin], minocycline [Minocin], oxytetracycline [Terramycin], tetracycline [Achromycin V, Panmycin, Sumycin]). Because meat contains iron, which binds tetracyclines into com- pounds the body cannot absorb, it is best to avoid meat for two hours before and after taking one of these antibiotics. Monoamine oxidase (MAO) inhibitors. Meat “tenderized” with papaya or a papain powder can interact with the class of antidepressant drugs known as monoamine oxidase inhibi- tors. Papain meat tenderizers work by breaking up the long chains of protein molecules. One by-product of this process is tyramine, a substance that constructs blood vessels and raises blood pressure. M AO inhibitors inactivate naturally occurring enzymes in your body that metabolize tyramine. If you eat a food such as papain-tenderized meat, which is high in tyramine, while you are taking a M AO inhibitor, you cannot effectively eliminate the tyramine from your body. The result may be a hypertensive crisis. Theophylline. Charcoal-broiled beef appears to reduce the effectiveness of theophylline because the aromatic chemicals produced by burning fat speed up the metabolism of the- ophylline in the liver.... beef

Game Meat

(Bison, rabbit, venison)

Nutritional Profile Energy value (calories per serving): Moderate Protein: High Fat: Low Saturated fat: High Cholesterol: Moderate Carbohydrates: None Fiber: None Sodium: Low Major vitamin contribution: B vitamins Major mineral contribution: Iron, zinc

About the Nutrients in This Food Like other animal foods, game meat has high-quality proteins with suf- ficient amounts of all the essential amino acids. Some game meat has less fat, saturated fat, and cholesterol than beef. All game meat is an excellent source of B vitamins, plus heme iron, the form of iron most easily absorbed by your body, and zinc. For example, one four-ounce serving of roast bison has 28 g protein, 2.7 g fat (1.04 g saturated fat), 93.7 mg cholesterol, 3.88 mg iron (25.8 percent of the R DA for a woman of childbearing age), and 4.1 mg zinc (27 percent of the R DA for a man). The Nutrients in Roasted Game Meat (4-ounce serving)

The Most Nutritious Way to Serve This Food With a food rich in vitamin C. Vitamin C increases the absorption of iron.

Diets That May Restrict or Exclude This Food Low-protein diet (for kidney disease)

Buying This Food In American markets, game meats are usually sold frozen. Choose a package with no leaks or stains to suggest previous defrosting.

Storing This Food Keep frozen game meat well wrapped in the freezer until you are ready to use it. The packaging protects the meat from oxygen that can change its pigments from reddish to brown. Freezing prolongs the freshness of the meat by slowing the natural multiplication of bacteria that digest proteins and other substances on the surface, converting them to a slimy film. The bacteria also change the meat’s sulfur-containing amino acids methionine and cystine into smelly chemicals called mercaptans. When the mercaptans combine with myoglobin, they produce the greenish pigment that gives spoiled meat its characteristic unpleasant appearance. Large cuts of game meat can be safely frozen, at 0°F, for six months to a year.

Preparing This Food Defrost the meat in the refrigerator to protect it from spoilage. Trim the meat to dispose of all visible fat, thus reducing the amount of fat and cholesterol in each serving. When you are done, clean all utensils thoroughly with hot soap and hot water. Wash your cutting board, wood or plastic, with hot water, soap, and a bleach-and-water solution. For ultimate safety in preventing the transfer of microorganisms from the raw meat to other foods, keep one cutting board exclusively for raw meats, fish, and poultry, and a second one for everything else. Finally, don’t forget to wash your hands.

What Happens When You Cook This Food Cooking changes the way meat looks and tastes, alters its nutritional value, makes it safer, and extends its shelf life. Browning meat before you cook it does not “seal in the juices,” but it does change the flavor by caramelizing proteins and sugars on the surface. Because meat’s only sugars are the Game Meat  

63 small amounts of glycogen in muscle tissue, we add sugars in marinades or basting liquids that may also contain acids (vinegar, lemon juice, wine) to break down muscle fibers and tenderize the meat. (NOTE : Browning has one minor nutritional drawback. It breaks amino acids on the surface of the meat into smaller compounds that are no longer useful proteins.) When meat is heated, it loses water and shrinks. Its pigments, which combine with oxygen, are denatured (broken into fragments) by the heat. They turn brown, the natural color of well-done meat. At the same time, the fats in the meat are oxidized, a reaction that produces a characteristic warmed-over flavor when the cooked meat is refrigerated and then reheated. Cooking and storing the meat under a blanket of antioxidants—catsup or a gravy made of tomatoes, peppers and other vitamin-C rich vegetables—reduces fat oxidation and lessens the warmed-over flavor. Meat reheated in a microwave oven is also less likely to taste warmed-over.

How Other Kinds of Processing Affect This Food Aging. Hanging fresh meat exposed to air in a cold room evaporates moisture and shrinks the meat slightly. At the same time, bacterial action on the surface of the meat breaks down proteins, producing an “aged” flavor. (See below, Food/drug interactions.) Curing. Salt-curing preserves meat through osmosis, the physical reaction in which liquids flow across a membrane, such as the wall of a cell, from a less dense to a more dense solu- tion. The salt or sugar used in curing dissolve in the liquid on the surface of the meat to make a solution that is more dense than the liquid inside the cells of the meat. Water flows out of the meat and out of the cells of any microorganisms living on the meat, killing the micro-organisms and protecting the meat from bacterial damage. Salt-cured meat is higher in sodium than fresh meat. Smoking. Hanging fresh meat over an open fire slowly dries the meat, kills microorgan- isms on its surface, and gives the meat a rich, smoky flavor. The flavor varies with the wood used in the fire. Meats smoked over an open fire are exposed to carcinogenic chemicals in the smoke, including a-benzopyrene. Artificial smoke flavoring is commercially treated to remove tar and a-benzopyrene.

Medical Uses and/or Benefits Treating and/or preventing iron deficiency. Without meat in the diet, it is virtually impossible for an adult woman to meet her iron requirement without supplements.

Adverse Effects Associated with This Food Increased risk of cardiovascular disease. Like all foods from animals, game meats are a source of cholesterol. To reduce the risk of heart disease, the National Cholesterol Education Project recommends following the Step I and Step II diets. The Step I diet provides no more than 30 percent of total daily calories from fat, no more than 10 percent of total daily calories from saturated fat, and no more than 300 mg of cholesterol per day. It is designed for healthy people whose cholesterol is in the range of 200 –239 mg/dL. The Step II diet provides 25– 35 percent of total calories from fat, less than 7 percent of total calories from saturated fat, up to 10 percent of total calories from polyunsaturated fat, up to 20 percent of total calories from monounsaturated fat, and less than 300 mg cho- lesterol per day. This stricter regimen is designed for people who have one or more of the following conditions: •  Existing cardiovascular disease •  High levels of low-density lipoproteins (LDLs, or “bad” cholesterol) or low levels of high-density lipoproteins (HDLs, or “good” cholesterol) •  Obesity •  Type 1 diabetes (insulin-dependent diabetes, or diabetes mellitus) •  Metabolic syndrome, a.k.a. insulin resistance syndrome, a cluster of risk fac- tors that includes type 2 diabetes (non-insulin-dependent diabetes) Food-borne illness. Improperly cooked meat contaminated with E. coli O157:H7 has been linked to a number of fatalities in several parts of the United States. In addition, meat con- taminated with other bacteria, viruses, or parasites poses special problems for people with a weakened immune system: the very young, the very old, cancer chemotherapy patients, and people with HIV. Cooking meat to an internal temperature of 140°F should destroy Salmo- nella and Campylobacter jejuni; to 165°F, E. coli, and to 212°F, Listeria monocytogenes. Decline in kidney function. Proteins are nitrogen compounds. When metabolized, they yield ammonia that is excreted through the kidneys. In laboratory animals, a sustained high-pro- tein diet increases the flow of blood through the kidneys, accelerating the natural age-related decline in kidney function. Some experts suggest that this may also occur in human beings.

Food/Drug Interactions Monoamine oxidase (MAO) inhibitors. Meat “tenderized” with papaya or a papain powder can interact with the class of antidepressant drugs known as monoamine oxidase inhibi- tors. Papain meat tenderizers work by breaking up the long chains of protein molecules. One by-product of this process is tyramine, a substance that constructs blood vessels and raises blood pressure. M AO inhibitors inactivate naturally occurring enzymes in your body that metabolize tyramine. If you eat a food such as papain-tenderized meat, which is high in tyramine, while you are taking an M AO inhibitor, you cannot effectively eliminate the tyramine from your body. The result may be a hypertensive crisis.... game meat

Lactulose

An osmotic laxative (see OSMOSIS; LAXATIVES), lactulose is a semisynthetic disaccharide – a type of carbohydrate – which is not absorbed from the GASTROINTESTINAL TRACT. It reduces the acidity of FAECES.... lactulose

Laxatives

Drugs or other substances used to treat CONSTIPATION. Also called aperients or purgatives, laxatives are classi?ed according to their mode of action. The four main groups are bulk, stimulant, faecal softeners and osmotics. In addition, bowel-cleansing solutions are used before surgery, ENDOSCOPY, or radiological examination of the COLON, to ensure that the bowel is clear of solid matter. However, these are not procedures for treating constipation.

People should be aware that normal bowel habits vary greatly, from twice a day to once every two or even three days. Any change from normal frequency to irregular or infrequent defaecation may signal constipation. Furthermore, before laxatives are prescribed, it is essential to ensure that the constipation is not the result of an underlying condition producing ‘secondary’ constipation. Individuals should not use laxatives too often or indiscriminately; persistent constipation is a reason to seek medical advice.

Bulk laxatives include bran and most high-?bre foods, such as fruit, vegetables and wholemeal foods. These leave a large indigestible residue that holds water in the gut and produces a large soft stool. Isphaghula husk, methyl cellulose and stercula are helpful when bran is ine?ective. Inorganic salts such as magnesium sulphate (Epsom Salts) have a similar e?ect.

Stimulant laxatives – for example, bisacodyl, senna and docusate sodium – stimulate PERISTALSIS, although the action may be accompanied by colicky pains.

Faecal softeners (emollients) There are two groups: surface active agents such as dioctyl sodium and sulphosuccinate which retain water in the stools and are often combined with a stimulant purgative; and liquid para?n which is chemically inert and is said to act by lubrication.

Osmotic laxatives These substances act by holding ?uid in the bowel by OSMOSIS, or by altering the manner in which water is distributed in the FAECES. Magnesium salts are used to produce rapid bowel evacuation, although one of them, magnesium hydroxide, should be used only occasionally. Phosphate or sodium citrate enemas (see ENEMA) can be used for constipation, while the former is used to ensure bowel evacuation before abdominal radiological procedures, endoscopy and surgery.... laxatives

Arthritis – Osteo

Osteo-arthritis. Erosion of cartilage of a joint with pain and stiffness. “Wear and tear” arthritis of the over 50s, affecting hands, knees, spine or hips. Biochemical changes in the cartilage stimulate overgrowth of bone cells (hyperplasia) which is an effort by the body to correct the disturbance.

Common in the elderly and menopausal women. Calcium salts may be laid down in a joint believed to be due to errors of diet. Small crystals of calcium hydroxyapatite have been observed to form in cartilage and synovial fluid. (Research group: St Bartholomew’s Hospital, London)

The aged sometimes suffer from diminished supply of hydrochloric acid in the stomach, and which is necessary for normal calcium metabolism. An effective substitute is 2 teaspoons cider vinegar in a glass of water sipped before or during meals.

Alte rnative s. Black Cohosh and Meadowsweet (natural sources of salicylic acid), Asafoetida (inflammation of connective tissue), Hawthorn (efficient circulation of the blood), Poke root, Bladderwrack, Guaiacum, Devil’s Claw, Bogbean, White Poplar bark, Yucca leaves.

Tea. Celery seeds. 1 teaspoon to each cup boiling water. Infuse 15 minutes. Half-1 cup, 2-3 times daily, before meals. Comfrey tea.

Alternative formulae:– Powders. White Willow 2; Devil’s Claw 1; Black Cohosh half; Guaiacum quarter. Mix. Dose: 500mg (two 00 capsules or one-third teaspoon). Thrice daily in water or Nettle tea. Liquid extracts. White Willow 2; Devil’s Claw 1; Bogbean 1; Fennel 1; Tincture Capsicum quarter. Mix. 1 teaspoon thrice daily in water or Nettle tea.

Tinctures. Bogbean 2; Meadowsweet 2; Black Cohosh 1; Guaiacum quarter; Peppermint quarter. Mix. Dose: 2 teaspoons thrice daily.

Tablets/capsules: Devil’s Claw, Wild Yam, Ligvites.

Cod liver oil. Chief of the iodised oils. Can reach and nourish cartilage by the process of osmosis. Its constituents filter into cartilage, imparting increased elasticity which prevents degeneration. Known to soften-up fibrous tissue. 2 teaspoons once daily. Also helps correct uric acid metabolism.

Topical. Physiotherapy. Osteopathy. Jojoba oil packs. Capsicum Cream. Hot and cold compresses twice daily – followed by a cold compress at night, leaving on when in bed. Hot Epsom salt bath twice weekly. Diet. Oily fish: see entry. Low fat. Low salt. High fibre. Avoid lemons and other citrus fruits. Lemon juice may remove some calculi from the body but later begins to remove calcium from the bones. Supplementation. Pantothenic acid 10mg; Vitamin A 7500iu; Vitamin B6 25mg; Vitamin E 400iu; Zinc 25mg.

General. Warm dry climate often relieves. Surgery may be necessary. Herbs Pleurisy root, Comfrey root and Bryonia, sustain the constitution and promote tissue healing after joint replacements with ceramic substitute after the famous Charnley operation. The condition is disabling but it is possible to manage successfully, maintaining normal activities with minimum difficulty. ... arthritis – osteo

Brain, Diseases Of

These consist either of expanding masses (lumps or tumours), or of areas of shrinkage (atrophy) due to degeneration, or to loss of blood supply, usually from blockage of an artery.

Tumours All masses cause varying combinations of headache and vomiting – symptoms of raised pressure within the inexpansible bony box formed by the skull; general or localised epileptic ?ts; weakness of limbs or disordered speech; and varied mental changes. Tumours may be primary, arising in the brain, or secondary deposits from tumours arising in the lung, breast or other organs. Some brain tumours are benign and curable by surgery: examples include meningiomas and pituitary tumours. The symptoms depend on the size and situation of the mass. Abscesses or blood clots (see HAEMATOMA) on the surface or within the brain may resemble tumours; some are removable. Gliomas ( see GLIOMA) are primary malignant tumours arising in the glial tissue (see GLIA) which despite surgery, chemotherapy and radiotherapy usually have a bad prognosis, though some astrocytomas and oligodendronogliomas are of low-grade malignancy. A promising line of research in the US (in the animal-testing stage in 2000) suggests that the ability of stem cells from normal brain tissue to ‘home in’ on gliomal cells can be turned to advantage. The stem cells were chemically manipulated to carry a poisonous compound (5-?uorouracil) to the gliomal cells and kill them, without damaging normal cells. Around 80 per cent of the cancerous cells in the experiments were destroyed in this way.

Clinical examination and brain scanning (CT, or COMPUTED TOMOGRAPHY; magnetic resonance imaging (MRI) and functional MRI) are safe, accurate methods of demonstrating the tumour, its size, position and treatability.

Strokes When a blood vessel, usually an artery, is blocked by a clot, thrombus or embolism, the local area of the brain fed by that artery is damaged (see STROKE). The resulting infarct (softening) causes a stroke. The cells die and a patch of brain tissue shrinks. The obstruction in the blood vessel may be in a small artery in the brain, or in a larger artery in the neck. Aspirin and other anti-clotting drugs reduce recurrent attacks, and a small number of people bene?t if a narrowed neck artery is cleaned out by an operation – endarterectomy. Similar symptoms develop abruptly if a blood vessel bursts, causing a cerebral haemorrhage. The symptoms of a stroke are sudden weakness or paralysis of the arm and leg of the opposite side to the damaged area of brain (HEMIPARESIS), and sometimes loss of half of the ?eld of vision to one side (HEMIANOPIA). The speech area is in the left side of the brain controlling language in right-handed people. In 60 per cent of lefthanders the speech area is on the left side, and in 40 per cent on the right side. If the speech area is damaged, diffculties both in understanding words, and in saying them, develops (see DYSPHASIA).

Degenerations (atrophy) For reasons often unknown, various groups of nerve cells degenerate prematurely. The illness resulting is determined by which groups of nerve cells are affected. If those in the deep basal ganglia are affected, a movement disorder occurs, such as Parkinson’s disease, hereditary Huntington’s chorea, or, in children with birth defects of the brain, athetosis and dystonias. Modern drugs, such as DOPAMINE drugs in PARKINSONISM, and other treatments can improve the symptoms and reduce the disabilities of some of these diseases.

Drugs and injury Alcohol in excess, the abuse of many sedative drugs and arti?cial brain stimulants – such as cocaine, LSD and heroin (see DEPENDENCE) – can damage the brain; the effects can be reversible in early cases. Severe head injury can cause localised or di?use brain damage (see HEAD INJURY).

Cerebral palsy Damage to the brain in children can occur in the uterus during pregnancy, or can result from rare hereditary and genetic diseases, or can occur during labour and delivery. Severe neurological illness in the early months of life can also cause this condition in which sti? spastic limbs, movement disorders and speech defects are common. Some of these children are learning-disabled.

Dementias In older people a di?use loss of cells, mainly at the front of the brain, causes ALZHEIMER’S DISEASE – the main feature being loss of memory, attention and reasoned judgement (dementia). This affects about 5 per cent of the over-80s, but is not simply due to ageing processes. Most patients require routine tests and brain scanning to indicate other, treatable causes of dementia.

Response to current treatments is poor, but promising lines of treatment are under development. Like Parkinsonism, Alzheimer’s disease progresses slowly over many years. It is uncommon for these diseases to run in families. Multiple strokes can cause dementia, as can some organic disorders such as cirrhosis of the liver.

Infections in the brain are uncommon. Viruses such as measles, mumps, herpes, human immunode?ciency virus and enteroviruses may cause ENCEPHALITIS – a di?use in?ammation (see also AIDS/HIV).

Bacteria or viruses may infect the membrane covering the brain, causing MENINGITIS. Viral meningitis is normally a mild, self-limiting infection lasting only a few days; however, bacterial meningitis – caused by meningococcal groups B and C, pneumococcus, and (now rarely) haemophilus – is a life-threatening condition. Antibiotics have allowed a cure or good control of symptoms in most cases of meningitis, but early diagnosis is essential. Severe headaches, fever, vomiting and increasing sleepiness are the principal symptoms which demand urgent advice from the doctor, and usually admission to hospital. Group B meningococcus is the commonest of the bacterial infections, but Group C causes more deaths. A vaccine against the latter has been developed and has reduced the incidence of cases by 75 per cent.

If infection spreads from an unusually serious sinusitis or from a chronically infected middle ear, or from a penetrating injury of the skull, an abscess may slowly develop. Brain abscesses cause insidious drowsiness, headaches, and at a late stage, weakness of the limbs or loss of speech; a high temperature is seldom present. Early diagnosis, con?rmed by brain scanning, is followed by antibiotics and surgery in hospital, but the outcome is good in only half of affected patients.

Cerebral oedema Swelling of the brain can occur after injury, due to engorgement of blood vessels or an increase in the volume of the extravascular brain tissue due to abnormal uptake of water by the damaged grey (neurons) matter and white (nerve ?bres) matter. This latter phenomenon is called cerebral oedema and can seriously affect the functioning of the brain. It is a particularly dangerous complication following injury because sometimes an unconscious person whose brain is damaged may seem to be recovering after a few hours, only to have a major relapse. This may be the result of a slow haemorrhage from damaged blood vessels raising intracranial pressure, or because of oedema of the brain tissue in the area surrounding the injury. Such a development is potentially lethal and requires urgent specialist treatment to alleviate the rising intracranial pressure: osmotic agents (see OSMOSIS) such as mannitol or frusemide are given intravenously to remove the excess water from the brain and to lower intracranial pressure, buying time for de?nitive investigation of the cranial damage.... brain, diseases of

Arthritis – Rheumatoid

A systemic inflammatory disease of several joints together where erosive changes occur symmetrically, and which may arise from inflammation and thickening of the synovial membrane. Cartilage becomes eroded and fibrous or even bony fusion leads to permanent fixation of a joint, or joints. Polyarthritis. An auto-immune disease.

Symptoms. Morning stiffness and pain wearing off later. Easy fatigue and decline in health. Nodules on surface of bones (elbows, wrists, fingers). Joint fluids (synovia) appear to be the object of attack for which abundant Vitamin C is preventative. Anaemia and muscle wasting call attention to inadequate nutrition, possibly from faulty food habits for which liver and intestine herbs are indicated.

Treatment. Varies in accord with individual needs. May have to be changed many times before progress is made. Whatever treatment is prescribed, agents should have a beneficial effect upon the stomach and intestines to ensure proper absorption of active ingredients. (Meadowsweet)

It is a widely held opinion that the first cause of this condition is a bacterial pathogen. An anti- inflammatory herb should be included in each combination of agents at the onset of the disease. See: ANTI-INFLAMMATORY HERBS. Guaiacum (Lignum vitae) and Turmeric (Curcuma longa) have a powerful anti-inflammatory action and have no adverse effects upon bone marrow cells or suppress the body’s immune system. Breast feeding cuts RA death rate.

Of therapeutic value according to the case. Agrimony, Angelica root, Balmony, Black Cohosh (particularly in presence of low back pain and sciatica), Bogbean, Boldo, Burdock, Celery, Cramp bark, Devil’s Claw, Echinacea (to cleanse and stimulate lymphatic system), Ginseng (Korean), Ginseng (Siberian), Liquorice, Meadowsweet, Poke root, Prickly Ash bark, White Poplar bark, White Willow bark, Wild Yam.

Tea. Formula. Equal parts. Alfalfa, Bogbean, Nettles. 1 heaped teaspoon to each cup boiling water; infuse 5-10 minutes, 1 cup thrice daily.

Decoction. Prickly Ash bark 1; Cramp bark 1; White Willow bark 2. Mix. 1oz to 1 pint water gently simmered 20 minutes. Dose: Half-1 cup thrice daily.

Tablets/capsules. Black Cohosh, Celery, Cramp bark, Devil’s Claw, Feverfew, Poke root, Prickly Ash, Wild Yam, Ligvites.

Alternative formulae:– Powders. White Willow bark 2; Devil’s Claw 1; Black Cohosh half; Ginger quarter. Mix. Dose: 750mg (three 00 capsules or half a teaspoon) thrice daily.

Liquid extracts. White Willow bark 2; Wild Yam half; Liquorice half; Guaiacum quarter. Mix. Dose: 1-2 teaspoons thrice daily.

Tinctures. Cramp bark 1; Bogbean 1; Prickly Ash half; Meadowsweet 1; Fennel half. Mix. Dose: 1-3 teaspoons thrice daily.

Ligvites. (Gerard House)

Cod Liver oil. Contains organic iodine, an important factor in softening-up fibrous tissue, to assist metabolism of uric-acid, help formation of haemoglobin, dilate blood vessels; all related to arthritics. The oil, taken internally, can reach and nourish cartilage by the process of osmosis; its constituents filter into cartilage and impart increased elasticity.

Topical. Evening Primrose oil, Wintergreen lotion, Comfrey poultice. Hydrotherapy: hot fomentations of Hops, Chamomile or Ragwort. Cold water packs: crushed ice or packet of frozen peas in a damp towel applied daily for 10 minutes for stiffness and pain. See: MASSAGE OIL.

Aromatherapy. Massage oils, any one: Cajeput, Juniper, Pine or Rosemary. 6 drops to 2 teaspoons Almond oil.

Supportives: under-water massage, brush baths, sweat packs, Rosemary baths, exposure of joints to sunlight.

Diet. Low salt, low fat, oily fish, Mate tea, Dandelion coffee. On exacerbation of the disease cut out all dairy products.

Supplements. Daily. Evening Primrose capsules: four 500mg; Vitamin C (1-3g); Bromelain 250mg between meals; Zinc 25mg.

General. Residence in a warm climate. Yoga. Disability and deformity may be avoided by a conscientious approach to the subject. ... arthritis – rheumatoid

Albumin

The most abundant protein in the blood plasma. Albumin is made in the liver from amino acids. It helps to retain substances (such as calcium, some hormones, and certain drugs) in the circulation by binding to them to prevent them from being filtered out by the kidneys and excreted. Albumin also regulates the movement of water between tissues and the bloodstream by osmosis. (See also albuminuria.)... albumin

Ion

A particle that carries an electrical charge; positive ions are called cations and negative ions are called anions. Many vital body processes, such as the transmission of nerve impulses, depend on the movement of ions across cell membranes. Sodium is the principal cation in the fluid that bathes all cells (extracellular fluid). It affects the flow of water into and out of cells (see osmosis), thereby influencing the concentration of body fluids.

The acidity of blood and other body fluids depends on the level of hydrogen cations, which are produced by metabolic processes. To prevent the fluids from becoming too acidic, hydrogen cations are neutralized by bicarbonate

anions in the extracellular fluid and blood, and by phosphate anions inside cells (see acid–base balance).... ion

Exosmosis

n. outward osmotic flow. See also osmosis.... exosmosis

Oncotic Pressure

a pressure represented by the pressure difference that exists between the osmotic pressure of blood and that of the lymph or tissue fluid. Oncotic pressure is important for regulating the flow of water between blood and tissue fluid. See also osmosis.... oncotic pressure

Osm

(osmo-) combining form denoting 1. smell or odour. 2. osmosis or osmotic pressure.... osm

Plasmolysis

n. a process occurring in bacteria and plants in which the protoplasm shrinks away from the rigid cell wall when the cell is placed in a *hypertonic solution. Plasmolysis is due to withdrawal of water from the cell by *osmosis.... plasmolysis

Tonicity

n. 1. the normal state of slight contraction, or readiness to contract, of healthy muscle fibres. 2. the effective osmotic pressure of a solution. See hypertonic; hypotonic; osmosis.... tonicity

Water

A simple compound that is essential for all life. Its molecular structure is H2O (2 atoms of hydrogen bonded to 1 of oxygen). Water is the most common substance in the body, accounting for about 99 per cent of all molecules, but a smaller percentage of total body weight. Approximately 2 thirds of the body’s water content is contained within the body cells, and the remaining third is extracellular (found, for example, in the blood plasma, lymph, and cerebrospinal and tissue fluid).

Water provides the medium in which all metabolic reactions take place (see metabolism), and transports substances around the body. The blood plasma carries water to all body tissues, and excess water from tissues for elimination via the liver, kidneys, lungs, and skin. The passage of water in the tissue fluid into and out of cells takes place by osmosis.

Water is taken into the body in food and drink and is lost in urine and faeces, as exhaled water vapour, and by sweating (see dehydration). The amount of water excreted in urine is regulated by the kidneys (see also ADH). Extra water is needed to excrete excess amounts of substances, such as sugar or salt, in the blood, and high water intake is essential in hot climates where a large amount of water is lost in sweat.

In some disorders, such as kidney failure or heart failure, insufficient water is excreted in the urine, resulting in oedema.... water




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