HEALTH AND MEDICINE

What are the odds against being struck by lightning?
606,944 to 1 against.

Which direction of impact results in the greatest number of fatalities in automobile crashes?
Frontal crashes are responsible for the largest percentage of fatalities in passenger cars.

What is “good” and “bad” cholesterol?
Chemically a lipid, cholesterol is an important constituent of body cells. This fatty substance, produced mostly in the liver, is involved in bile salt and hormone formation, and in the transport of fats in the bloodstream to the tissue throughout the body. Both cholesterol and fats are transported around as lipoproteins (units having a core of cholesterol and fats in varying proportions, with an outer wrapping of carrier protein [phospholoids and apoproteins]). An overabundance of cholesterol in the bloodstream can be an inherited trait, can be triggered dietary intake, or can be the result of a metabolic disease, such as diabetes mellitus. Dietary fats (from meats, oil, and dairy products) strongly affect the cholesterol level. High cholesterol levels in the blood may lead to a narrowing of the inner lining of the coronary arteries from the build-up of a fatty tissue called atheroma. This increases the risk of coronary heart disease or stroke. However, if most cholesterol in the blood is in the form of high density lipoproteins (“HDL”), then it seems to protect against arterial disease. HDL picks up cholesterol in the arteries and brings it back to the liver for excretion or reprocessing. HDL is referred to as “good cholesterol.” Conversely, if most cholesterol is in the form of low density lipoproteins (“LDL”), or very low density lipoproteins (“VLDL”), then arteries can become clogged. “Bad cholesterol” is a term used to refer to LDL and VLDL.

How long does it take to bleed to death?
If a large blood vessel is severed or lacerated, a person can bleed to death in one minute or less. Rapid loss of one quart or more of the total blood volume often leads to irreversible shock and death.

The deadliest natural toxin:
Botulinal toxin, produced by the bacterium Clostridium botulinum, is the most potent poison for humans. It has an estimated lethal dose in the bloodstream of 10-9 milligrams per kilogram.

The most common disease:
The most common noncontagious disease is periodontal disease, such as gingivitis or inflammation of the gums. The most common contagious disease in the world is coryza, or the common cold.

The deadliest diseases are:
The Black Death of 1347 – 1351, with a mortality rate of 100%. Today, the disease with the highest mortality (almost 100%) is rabies in humans, when it prevents the victim from swallowing water. This disease is not to be confused with the symptoms resulting from being bitten by a rabid animal. With immediate attention after an animal bite, the rabies virus can be prevented from invading the nervous system and the survival rate in this circumstance is 95%. The AIDS virus (acquired immunodeficiency virus), first reported in 1981.

What are the symptoms and signs of AIDS?
The early symptoms (called AIDS-related complex, or ARC, symptoms) of AIDS infection include night sweats, prolonged fevers, severe weight loss, persistent diarrhea, skin rash, persistent cough, and shortness of breath. The diagnosis changes to AIDS (acquired immunodeficiency syndrome) when the immune system is affected and the patient becomes susceptible to opportunistic infections and unusual cancers, such as herpes viruses (herpes simplex, herpes zoster, cytomegalovirus infection), candida albicans (fungus) infection, cryptosporidium enterocolitis (protozoan intestinal infection), pneumocystis carinii pneumonia (PCP, a common AIDS lung infection), toxoplasmosis (protozoan brain infection), progressive multifocal leukoencephalopathy (PML, a central nervous system disease causing gradual brain degeneration), mycobacterium avium intercellulare infection (MAI, a common generalized bacterial infection), and Kaposi’s sarcoma (a malignant skin cancer characterized by blue-red nodules on limbs and body, and internally in the gastrointestinal and respiratory tracts, where the tumors cause severe internal bleeding). More than 75% of AIDS victims die within two years of diagnosis.
The signs of AIDS include generalized swollen glands, emaciation, blue or purple-brown spots on the body, especially on the legs and arms, prolonged pneumonia, and oral thrush.

What is a stroke?
A stroke, or cerebrovascular accident (CVA), is a medical emergency produced by a blood clot that lodges in an artery and blocks the flow of blood to a portion of the brain. Less commonly, a stroke may be the result of bleeding into the substance of the brain. Certain factors increase the risk of stroke, such as high blood pressure (hypertension), which weakens artery walls, and atherosclerosis (thickening of the lining of the artery walls), which narrows arteries.

Dyslexia defined:
Dyslexia covers a wide range of language difficulties. In general, a person with dyslexia cannot group the meaning of sequences of letters, words, or symbols or the concept of direction. Dyslexic children may reverse letter and word order, make bizarre spelling errors, and may not be able to name colors or write from dictation. It may be caused by minor visual defects, emotional disturbance, or failure to train the brain. New evidence shows that a neurological disorder may be the underlying cause. Approximately 90% of dyslexics are male.

Anorexia defined:
Anorexia simply means a loss of appetite. Anorexia nervosa is a psychological disturbance that is characterized by an intense fear of being fat. It usually affects teenage or young adult females. This persistent “fat image,” however untrue in reality, leads the patient to self-imposed starvation and emaciation (extreme thinness) to the point where one-third of the body weight is lost. Symptoms include a 25% or greater weight loss (for no organic reason) coupled with a morbid dread of being fat, an obsession with food, an avoidance or eating, compulsive exercising and restlessness, binge eating followed by induced vomiting, and/or use of laxatives or diuretics.

How is blood pressure measured?
A sphygmomanometer is the device used to measure blood pressure. It consists of a cuff with an inflatable bladder that is wrapped around the upper arm, a rubber bulb to inflate the bladder, and a device that indicates the pressure of blood. Measuring arterial tension (blood pressure) of a person’s circulation is achieved when the cuff is applied to the arm over the artery and pumped to a pressure that occludes or blocks it. This gives the systolic measure, or the maximum pressure of the blood, which occurs during contraction of the ventricles of the heart. Air is them released from the cuff until the blood is first heard passing through the opening artery (called Korotkoff sounds). This gives diastolic pressure, or the minimum value of blood pressure that occurs during the relaxation of the arterial-filling phase of the heart’s activity.

What is the meaning of the numbers in a blood pressure reading?
When blood is forced into the aorta, it exerts a pressure against the walls; this is referred to as blood pressure. In the reading, the upper number, the systolic, measures the pressure during the period of the heart’s ventricular contraction. The lower number, the diastolic, measures the pressure when blood is entering the relaxed chambers of the heart. While these numbers can vary due to age, sex, weight, and other factors, the normal blood pressure is around 115/75 to 140/90 millimeters of mercury.

What are the normal test ranges for total cholesterol, triglycerides, low density lipoproteins (LDL), and high density lipoproteins (HDL)?
Normal blood cholesterol levels can range from 150 to 289 milligrams per deciliter. In order to lower the risk of coronary heart disease, the recommended total cholesterol level is less than 200 milligrams per deciliter. A range of 200 to 239 is considered to be “borderline” and anything above 240 milligrams per deciliter is considered to be high. LDL – cholesterol in the blood seems to encourage the formation of artery-clogging fatty deposits, so its level should be below 130 milligrams per deciliter (130 to 159 is considered borderline and greater than 160 is high risk). However, the average LDL – cholesterol level is around 150 milligrams per deciliter, with the normal range occurring between 100 and 200. The average HDL-cholesterol level is 55 milligrams per deciliter with the normal range being between 30 and 80. Anything less than 35 is considered a risk factor for a heart attack. The ratio of total cholesterol to HDL-cholesterol (which washes out excess cholesterol from the blood) should be 3.5 to 4.5. Triglycerides (fatty substances consisting of fatty acids and glycerol that are usually stored as fat as an energy reserve) range from 30 to 145 milligrams per deciliter.

How many of the medications used today are derived from plants?
Of the more than 250,000 known plant species, less than 1% have been thoroughly tested for medical applications. Yet out of this tiny portion have come 25% of our prescription medicines. The United States National Cancer Institute has identified three thousand plants from which anti-cancer drugs are or can be made. This includes ginseng (Panax quinquefolius), Asian mayapple (Podophyllum hexandrum), western yew (Taxus brevifolia), and rosy periwinkle. 70% of these three thousand come from rain forests, which are also a source of countless other drugs treating diseases and infections. Rain forest plants are rich in so-called secondary metabolites, particularly alkaloids, which biochemists believe the plants produce to protect them from disease and insect attack.

Why anabolic steroids are harmful?
Anabolic (protein-building) steroids are drugs that mimic the effects of testosterone and other male sex hormones. They can build muscle tissue, strengthen bone, and speed muscle recovery following exercise or injury. They are sometimes prescribed to treat osteoporosis in postmenopausal women and some types of anemia. Some athletes use anabolic steroids to build muscle strength and bulk, and to allow a more rigorous training schedule. Weight lifters, field event athletes, and body builders are most likely to use anabolic steroids. The drugs are banned from most organized competitions because of the dangers they pose to health and prevent an unfair advantage. Adverse effects include hypertension, acne, edema, and damage to liver, heart, and adrenal glands. Psychiatric symptoms can include hallucinations, paranoid delusions, and manic episodes. In men, anabolic steroids can cause infertility, impotence, and premature balding. Women can develop masculine characteristics, such as excessive body and facial hair growth, male-pattern balding, disruption of menstruation, and deepening of the voice. Children and adolescents can develop problems in growing bones, leading to short stature.

Does catgut really come from cats?
Catgut, an absorbable sterile strand, is obtained form collagen derived from healthy mammals. It was originally prepared from the submucous layer of the intestines of sheep. It is used as a surgical ligature.

Why are eye transplants are not available?
The eye’s retina is part of the brain, and the retina’s cells are derived from brain tissue. Retinal cells and the cells that connect them to the brain are the least amenable to being manipulated outside the body.

Reflexology defined:
Reflexology – an ancient Chinese and Egyptian therapy – is the application of specific pressures to reflex points in the hands and feet. The reflex points relate to every organ and every part of the body. Massaging of the reflex points is done to prevent or cure diseases.