Health related information and news from around the world.

HEART SURGERY: TRANSPLANTS

admin — Wed, 27 Jul 2011 17:29:08 +0000

The patient-controlled treatment prescribed for clogged arteries includes regular checkups, a low-fat diet, exercise, relaxation, and no smoking. Success depends on the patients’ willingness and determination to trade in their harmful old habits for healthful new ones that will enable them to enjoy longer lives. The heart transplant – the most dramatic surgery of all-probably pays off best in the number of years of life gained.A transplant replaces the failed heart that, weakened by heart attack or infection, produces a blood flow that has declined to a trickle. While anywhere from 11,000 to 20,000 patients are eligible for heart transplants, on average, only about 2,000 hearts are available yearly in the United States. It becomes a waiting game.To maximize the survival chances of those who wait for a heart transplant, these choices are offered:• The use of new mechanical hearts to sustain the patient waiting for a donor heart. These machines, intended for temporary use, are working increasingly well and may prove equal to or better than transplants, which have a 5-year survival rate of 50 percent.• The use of animal hearts with medications to prevent rejection. This technique has been tried four times, but the recipients rejected the organs and died.• Heart-strengthening medications to help transplant candidates’ survive while on the waiting list for a new heartBut a crisis is emerging.”If we continue to list so many [non-critical] patients for transplantation as we now do,” says Dr. Stevenson, “in 4 years’ time we will reach a point where none of the unhospitalized patients will have a chance for a transplant. People have to wait too long. They deteriorate, making their chance for survival poor.”One heart transplant recipient, Brenda Butler Hamiett, then 48, of Jamaica Plain, Massachusetts, says, “Before my transplant, I was too tired to blink.” Now, Mrs. Hamiett reports, she happily exercises, watches her diet, and keeps track of her blood pressure.Dr. Adrian Kantrowitz, professor of surgery at Wayne State University College of Medicine in Detroit, was the first to implant a human heart in the United States, at Maimonides Hospital in Brooklyn, New York, 3 days after the world’s first human heart transplant by Dr. Barnard in 1967. Dr. Kantrowitz cites good results from heart surgeries for infants, too.”We repair congenital defects extremely well,” says Dr. Kantrowitz, “and we successfully operate on infants born with impaired connections between the heart arteries.” He places the mortality rate for that surgery at less than a tenth of 1 percent. For valve replacement surgery, when using plastic or stainless-steel devices or valves taken from pigs, the rate is 2 percent, he says.The final verdict on the effectiveness of these procedures is not yet in, but all heart disease must be treated-by you as well as your doctor.*16/266/5*

WHY YOU CAN’T STAY AWAKE: SUDDEN INFANT DEATH SYNDROME

admin — Thu, 14 Jul 2011 17:22:53 +0000

Before leaving the subject of sleep apnea, I want to discuss briefly the problem of sudden infant death syndrome—SIDS, also known as crib death. Each year this tragic affliction strikes as many as 10,000 to 18,000 babies between the ages of one and seven months. The exact cause of SIDS, unfortunately, is not yet known. Many experts believe it is a form of sleep apnea during which the re not yet fully developed, may stop breathing long whose central nervous system and respiratory drive enough to result in death. In some cases the infant is found to have a mild case of upper respiratory tract infection, or some mucus plugging the nose—seemingly a minor problem, until you realize that babies don’t learn to breathe through their mouths until the age of four months. Yet most normal infants commonly experience short spells of apnea; we don’t yet know how to identify those who may be at greater risk of SIDS so as to intervene and prevent its occurrence.If you are concerned about your child, some approaches to SIDS management are available: monitors attached to the crib may detect a breathing stoppage; alarms will wake the baby, causing it to begin breathing normally, and will alert others in the house as well. One psychologist reports some success in training infants to react vigorously to a breathing obstruction, such as a light cloth placed over the mouth for a short time.*149\226\8*

NATURAL MEN’S HEALTH: HOW TO EAT IN A HEALTHY WAY – COOKING AT HOME

admin — Thu, 07 Jul 2011 17:16:34 +0000

Although all recommendations for cooking sounds very simple I am always amazed how many men ask me how to throw together a protein and vegetable meal without much cooking.I would advise keeping pasta and noodles to a minimum. So many men eat pasta with a tomato sauce, which only sustains energy for a short time. If you feel like this once a week, then have it, but eat a healthy salad with tuna or eggs on the side for more nutrition.Some schools of thought advocate no protein foods in the evenings. It is true that red meat is very heavy, so I would suggest you try to have white meats, fish and vegetarian proteins such as legumes more often in the evenings as they are easier to digest.If you have eaten protein for breakfast and lunch and are not exercising greatly, then a plate of steamed vegetables in the evening is better. The only problem with this sort of evening meal is that you may be hungry within a few hours. Then there is a temptation to eat a lot of chocolate or ice-cream to satisfy your hunger. This is okay occasionally, but if you eat like this regularly then you will overload your system with sugar before bed and have restless sleep and an acid stomach.*101\28\8*

LIFE AFTER A HEART ATTACK

admin — Sun, 26 Jun 2011 10:40:34 +0000

Congratulations on your wonderful recovery from a heart attack. You are now up and about after the convalescent period. It takes about six months for nature’s repair processes to take full effect. Your doctor would have assessed the amount of damage suffered by your heart muscle, its repair and progress, the present status of the heart and its exercise tolerance. There is now no reason for despondency. People have lived for 25 years or more after a heart attack and have lived well. Only a bit of care and some precautions are necessary to ensure longevity and a trouble-free life in the future.Q. Can my heart function as long as it would have done had there been no heart attack ?A. Certainly; it is not only possible, but you can make it happen. Let me tell you a true story first.Thirty years ago I purchased a shaving mirror, a small beautiful round piece, and I loved it very much. Unfortunately my small son cracked a corner soon after purchase. I felt unhappy, repaired it with araldite and started reusing it. Since I loved the piece, I became doubly cautious in handling it. I still have the mirror and it is useful today as it was 30 years ago. I am sure, if it had not been damaged, I would not have given it the extra care that I did and it would have long ago disappeared.Similarly, your heart has survived an injury. Nature has healed it. With due care and by observing some precautions you can make it last for a long period probably longer than if nothing had happened to it. These precautions, mentioned here and in the following chapters, are simple and easy to follow.*86\328\8*

PAIN TREATMENT: WHOLE-PERSON THERAPIES

admin — Tue, 14 Jun 2011 10:33:45 +0000

Classical acupunctureAccording to ancient Chinese medicine, health is created and preserved by the flow of yin and yang, which are conflicting energies distributed to all parts of the body in defined channels, the meridians, which peak at points. The flow of energy can, it is claimed, be adjusted by inserting needles into the channels at these points. Chinese acupuncture investigators were unable to find the channels and now state that the effect is caused by the stimulation of special sensory nerve fibres. Most people think that acupuncture arrived in the West in recent times once China was opened up after the Nixon agreements. In fact, acupuncture was well known in the West in Elizabethan times, beginning with a text book by Ten Rhijne in 1683. The European enthusiasm for acupuncture faded until it was reintroduced in the eighteenth century by the French from Indochina. It again faded until mid nineteenth century, when Admiral Perry returned from Japan with a Japanese government delegation. Acupuncture arrived and faded four times in four centuries. Its use is fading again both here and in China. A therapy whose popularity fluctuates depends on social belief. Double-blind testing of which point to needle has shown no specificity.However, there is a variation of acupuncture that ignores the classical points and needles only painful spots of the type described in fibromyalgia. Janet Travell, who was White House physician to President Kennedy and treated his painful back, had been following the established practice of injecting local anaesthetics into these painful spots. She discovered that it was not necessary to inject the local anaesthetic as the penetrating needle was enough by itself. The needling produces a stab of pain followed by relaxation of the taut muscle band, followed in turn by some general soreness and then by relief, which may last for days. We see here again, as was suspected in some of the reactions to surgery, that generalized damage in a painful area may be followed by relief.YogaYoga was overtly intended to change the subjects’ attitude to themselves and to the world, and yet puts muscles, tendons and joints in highly unusual positions. The Alexander technique has similar aims and effects.*58\219\2*

GOALS OF DIABETES CONTROL

admin — Thu, 02 Jun 2011 10:25:39 +0000

Diabetes treatment programs are aimed at keeping the level of sugar in the blood normal. This will help prevent problems that result from uncontrolled blood sugar levels. In children, the treatment program must also provide for normal growth and development.Control requires balancing food intake, the amount of exercise, and insulin levels. Generally, food makes glucose levels rise; exercise and insulin make glucose levels fall. When the body is not producing enough effective insulin, it may have to be supplied by injections, or its production may be stimulated by oral hypoglycemic drugs.Just how tight a control is needed? Until 1993, that question was open to debate. Some diabetes specialists believed it wasn’t realistic to expect the average person with diabetes to be able to keep to the kind of strict routine necessary to keep the blood sugar level normal at all times. They thought that fluctuations were not too significant—as long as they didn’t reach the range that might result in ketoacidosis or a hypoglycemic reaction—and all the extra tests and injections that might be necessary to maintain tight control would not be worth the effort. But the report on the ten-year Diabetes Control and Complications Trial (DCCT) changed the diabetes picture dramatically.*28\268\2*

THE MOST CANCER-CAUSING OF THE HUMAN PAPILLOMAVIRUS

admin — Wed, 25 May 2011 10:17:25 +0000

The most cancer-causing of the human papillomavirus types create havoc by using proteins called E6 and E7. These proteins neutralize our bodies, safeguards against cancer. E6 binds to a protein called p53, which guards against cancer by arresting cell division. If E6 fails to take out p53, however, the human papillomavirus can still neutralize p53′s protective effects using E7, which binds to a second anticancer sentry stimulated by p53. E6 also interferes with the cell’s self-destruct mechanism, which can protect the rest of the body from pathogens in an infected cell. By these means the papillomavirus is able to keep the cells working in the interest of the virus rather than in the interest of the person. The lethality of cancer is as devastating to the virus as it is to the person, but the path leading to cancer is a clever solution to a difficult problem. Being sexually transmitted, the human papillomavirus has to deal with the fundamental constraint of sexual transmission: it has to be sufficiently persistent in sufficient numbers to capitalize on future opportunities for transmission. It needs to hide out from a primed and vigilant immune system. The clever solution of the papillomavirus is to keep the cell multiplying and then multiply right along with it. The more the cell divides, the more the virus can replicate itself with little exposure to the surveillance of the immune system. But how much of the racketeering is too much even for the virus? That depends on the opportunities for transmission. Little exposure to the immune system does not mean no exposure because even a small amount of exposure can make the virus vulnerable to the immune system’s sophisticated virus detection technology. When a virus is clandestinely active within a cell, the cell will post fragments of the virus on its outside walls. It’s like the warning sign posted on the walls of a quarantined house to notify the rest of the community. But the actions taken inside our bodies are not tempered by a liberal mind-set—extremism in defense of the body is no vice. When members of the immune system see the sign, they do not just stay away from the cell; they blow it up. The notice does not read keep out! but rather kill me! By posting this notice of infection, the cell is committing suicide to protect the other cells in the body from infection. For the most cancer-causing of the papillomavirus types, parts of the viruses’ E6 and E7 proteins are posted on the outside of the cell to attract the friendly fire of the immune system. These extreme responses by the body help control the infection in most women before it develops into cervical cancer. So even a papillomavirus that is clandestinely reproducing as the cells are reproducing may not be clandestine enough. Those viruses programmed for less of this manipulative reproduction may be less likely to attract the immunological attack. By keeping an extremely low profile, such viruses might increase the chances of their being around in the reproductive tract when a new sexual partner is selected. The suppressed activity of the virus translates into a lower probability of infection per instance of sexual contact, but a sexually active person who is not changing sex partners frequently will tend to have more sex with each partner; the sex is just spread out over a long period of time. So the virus’s low profile may still yield a high probability of infection per partner—if the partner is not infected today, then maybe next week, next month, or next year. That strategy is better for us because a virus that keeps a very low profile is a virus that is very unlikely to cause cancer. On the other hand, if people change partners frequently, then a virus with such self-restraint pays the price of missing transmission opportunities. In a promiscuous society, the papillomaviruses that trigger more rapid reproduction would tend to spread more effectively to new hosts. The more rapid reproduction may make the viruses less cryptic and hence more vulnerable to the immunological defenses of the current host, and more likely to cause a cancerous death or to fall victim to surgical excision, but the reduced tenancy in any single person is offset by the increase in transmission to new people. When opportunities for sexual transmission are high, the virus reaps a high return on its high rate of replication. The dividend is increased representation of the nasty types of papillomavirus in the overall papillomavirus population. When opportunities for sexual transmission abound, human papillomaviruses should evolve toward high virulence. This is not the kind of statement that can be tested with controlled experimentation. It would be a no-brainer for an NIH ethics committee. But human behavior, being what it is, gives us “natural experiments” that would be unethical had they been planned and executed. One of the most horrific of these situations occurred during the war in what was until recently Yugoslavia. Opportunities for venereal transmission typically increase during wartime, but in that war the opportunities were even greater because rape was used systematically as a weapon. If human papillomaviruses evolve increased harmfulness when the opportunities for transmission increase, they should have done so over the course of the war. Evidence indicates that they did. Just before the war researchers found that among sexually active women in the region, the most lethal papillomaviruses were less common than the milder types. But by the end of the war these lethal types outnumbered the more benign types by three to one. The vicious viruses increased tenfold over the two years of the war; the benign types remained close to their prewar level. By the third year after the war, the lethal types had begun to recede. Wartime conditions are extreme. Is there any evidence that the harmfulness of human papillomaviruses depends on sexual behavior in peacetime? Women who have more sexual partners do tend to have more papillomavirus infections. This trend holds from Sweden to Brazil to Colorado. But the risk is not the same for all types of papillomaviruses. The details are still unclear because sufficiently sensitive techniques have been applied only during the past few years, but the current evidence indicates that having more sexual partners increases disproportionately the risk of acquiring the most dangerous papillomaviruses. In Brazil during the mid-1990s, for example, the risks of acquiring the harmful and benign viruses were similar among women who had no more than five sexual partners during their lifetime. Women who had more than five but not more than ten were almost twice as likely to harbor the most dangerous types. Of the women who had more than ten partners, one third were infected with the most dangerous types, three times as many as among the women who had no more than five partners during their lifetime. The broader implication of these trends is clear: if people start having sex with more people or with less protection, venereal pathogens will not only spread but will evolve to become more harmful. This point makes clear why the threat of disease emergence is largely a homegrown problem. The raw materials for harmful and mild infections are already globally distributed; they are continually being re-seeded by rapid air travel as well as by biological mutations and recombinations, but these processes only provide the raw material. Whether we have a grave problem will depend on whether our local soil—our own behavior—favors the harmful forms over the mild forms.*35\225\2*

SMART DRUGS FOR MAXIMUM MENTAL PERFORMANCE: ERGOLOID MESYLATES (HYDERGINE)

admin — Sat, 14 May 2011 10:00:57 +0000

Of the 20,000 new substances that are produced annually in the pharmaceutical research laboratories of the world, the vast majority are modifications of a few types of active compounds that are already in use. Chemists employed by drug companies attempt these chemical modifications to produce new, patentable (thus profitable) compounds with similar and perhaps improved activity over existing pharmaceuticals. Smart drugs are no exception.In 1950, Dr. Albert Hofmann, a research scientist employed by the Swiss drug corporation Sandoz Pharmaceuticals, discovered a drug based on an existing molecule found in nature (a fungus that grows on grains) that he named Hydergine. Hofmann, a pioneer in the area of drags based on molecules in plants, would become more famous for another drug he synthesized, based on the same fungus, the “smart” drag of the 1960s known as LSD25. It is Hydergine, of course, that is the more important and safer smart drug.Hydergine is the most widely used smart drug available in the United States today. It acts in many ways to enhance mental capabilities and to slow down or reverse the aging processes in the brain. Among the major effects of this cognitive-enhancing drug are these:It prevents free-radical damage in the brain.It increases the blood supply to the brain.It enhances brain metabolism.It increases the delivery of oxygen to the brain.It protects against brain damage during periods of insufficient oxygen supply, such as during a stroke or asphyxiation.It slows the depositing of age pigment (lipofuscin, the stuff of which “age spots” are made) in the brain.It improves memory and recall.
Hydergine is actually a mixture of three fungus-derived chemicals (all derived from Claviceps purpurea). The Sandoz Pharmaceutical Company harvests Claviceps purpurea from rye fields in Europe and then extracts the fungi and chemically modifies them into the form used in the Hydergine formula. Hydergine is thus not a completely natural drug but, rather, a semisynthetic one because of the chemical steps necessary to change the natural fungus molecules into their final form.Sandoz originally introduced Hydergine as a treatment for senility (senile dementia). Since many of the symptoms of senility are caused by atherosclerosis and calcification of the arteries in the brain (which deprives brain cells of vital oxygen), Hydergine, which can improve the delivery of oxygen to brain neurons, was a likely candidate for an anti-senility drug. Accordingly, the FDA approved the use of Hydergine for the treatment of senility and related circulatory problems.Research published over the past fifteen years has shown Hydergine to be a safe and effective treatment for senility. Most people who were studied showed the greatest improvement with higher doses of Hydergine (4.5 to 6 milligrams per day), although the FDA has specifically limited the approved dosage of Hydergine to 3 milligrams per day (in Europe the approved dosage is 9 milligrams per day). Studies of humans have shown that the higher dosage levels are more effective. It is important to note that even at the higher dosage, there were no serious side effects.Although Hydergine produces significant cognitive improvements in people who are suffering from senility, it does not produce miracles. Many people experience only a small amount of improvement in mental function, especially those with advanced senility. Hydergine is of greater benefit to people with mild to moderate mental deterioration, especially when Hydergine therapy is initiated soon after a medical diagnosis has been made.Even though the FDA has approved Hydergine for the treatment of senility and cerebrovascular insufficiency (poor blood circulation to the brain), physicians in many other countries prescribe it for use in healthy people to increase intelligence, memory, and recall and to prevent the free-radical damage to the brain that can lead to senility. Since the FDA prohibits drug manufacturers from disseminating this information to physicians, many health care professionals in the United States are unaware of the manifold uses of this marvelous smart drug.Hydergine is also good news for cigarette smokers. People who smoke more than 20 cigarettes a day experience a decline of at least 7 percent of the normal blood flow to the brain. This oxygen deprivation causes an increase in the number of free radicals and subsequent damage to brain neurons. Hydergine, a potent free-radical scavenger, may be just what the doctor ordered for tobacco addicts. In addition to neutralizing the toxic molecules that are created when tobacco burns, it may also help lessen the severity of damage to arteries to the brain, a problem caused and aggravated by smoking cigarettes. Of course, it’s better not to start smoking in the first place, and it’s advisable to quit immediately if you already smoke, but for people who are unwilling or unable to stop smoking, Hydergine(and antioxidant smart nutrients, such as beta-carotene, vitamin E, selenium, L-glutathione, and vitamin C) may provide a large measure of protection against the brain damage that smoking causes.How Hydergine Works. Hydergine helps increase the delivery of oxygen to the brain (by increasing blood flow) and neutralizes the free radicals that can cause permanent brain damage. Recent research indicates that Hydergine may also stimulate the synthesis of a substance called nerve growth factor that induces the growth of protein filamentous connections between neurons. These connections, called dendrites, facilitate communication throughout the central nervous system and are required for the storage and retrieval of memories. Hydergine also reduces the rate at which lipofuscin accumulates in the brain. Lipofuscin accretion has been implicated as a causative factor in the decline of cognitive functioning as we age.Since the Sandoz patent on Hydergine has expired, generic brands of dihydrogenated ergot alkaloids or ergoloid mesylates (the chemical names of the brand name Hydergine) are now available from a variety of companies in the United States and Europe. Keep in mind that in the United States, the FDA has approved a dosage of only 3 milligrams per day. The recommended daily dosage for Hydergine in Europe is 9 milligrams—3 milligrams taken three times daily.Many of the scientific research studies have used dosages closer to or higher than the European dosages, and several have shown that higher dosages of Hydergine produce significantly better results. Some researchers think that it may be best to start with a low dose and work up to larger doses to avoid any uncomfortable side effects, mild as they may be.
PRECAUTIONS: Hydergine is relatively nontoxic. Studies testing four times the FDA-allowed dosage revealed no measurable toxic effects in humans. Hydergine does not cause serious side effects, although there have been occasional reports of mild gastrointestinal discomfort and headaches in a small number of people who use it. These side effects are uncommon and have occurred in individuals who took large doses to start, rather than gradually increased the dosage. Hydergine is essentially nontoxic, even at dosage levels four times higher than those authorized by the FDA. However, people who have chronic or acute psychoses should be advised against it because it could lead to a worsening of the condition. Hydergine is a prescription drug that is currently approved by the FDA only for the treatment of senility; however your physician may legally prescribe it to prevent this condition.Dosage commonly used: 3 mg per day (United States); 9 mg in three divided doses (Europe).Sources: Hydergine is available as a prescription drug in the United States. Your physician may not yet be familiar with the cognition-enhancing and antiaging effects of Hydergine because the FDA prohibits drug companies from telling physicians about new (FDA unapproved) uses for drugs. There are a wide variety of generic forms of Hydergine, although some generics may not be identical to the original Sandoz formulation (because of a degree of latitude by the FDA in the structural requirements for the generic drug). Some researchers insist that the original Sandoz brand of Hydergine provides superior results than do the generic equivalents.*53\244\2*

DO YOU ADVISE PARENTS TO BE VERY CAREFUL AND STRICT IN PRESENCE OF CHILDREN?

admin — Fri, 06 May 2011 09:54:33 +0000

No, for instance those maturing young children who have bath with their mother or father and who see their parents hugging and kissing each others are much less likely to feel inhibited about their own bodies and feelings than those children whose parents behaviour instil the idea that sex is somehow dirty and shameful.
How parents should react knowing about masturbation of their child?
In general parents who discover their child masturbating get worried, embarassed and disapproving. If these views are openly expressed child will revolt and practice in privacy keeping the frequency of mastrubation the same. Hence parents taking in confidence should try to make them understand about the plus and minus points of involving in masturbation.
What is sexual rivalry between parent and child?Male child may feel jealous of his father because mother loves husband more and does not give sufficient attention to the child. Sometimes it may take the form of competition. This usually expresses itself as an attempt by the young child to prove that he or she loves the parent more than his rival does. A girl will try to look more beautiful than her mother and will help father in day to day work. Male child may go out of way to help his mummy in kitchen to gain her favour. Upto some extent it is natural and children should be made to understand that parents also have a right to care for each other.
When vagina is so small then how child comes out through it?Vagina is a flexible stretchy passage way about 3-5 inches long. During sexual arousal the vagina widens and lengthens by about two inches. If need arises during delivery it opens to a diameter of about five inches to accomodate the child.*98\301\2*

INFECTIONS: THEY’RE HERE

admin — Wed, 27 Apr 2011 09:45:51 +0000

Some infections will not peter out on their own even with all the infrastructure money can buy: infections transmitted by sex. But almost all the venereal diseases that are important in one geographic region have already spread globally. This global spread happened long ago because sexually transmitted pathogens tend to have prolonged periods of infectiousness, and people the world over are having sex. People infected with sexually transmitted organisms can carry them across oceans and mountains and around the world, whenever the people themselves can make such voyages. Could an early warning system work against these truly dangerous globe-trotting pathogens? Some experts imagine massive investments in surveillance and interdiction, but that proposal sounds disturbingly like the efforts directed against drug smuggling. Surely it would be an act of desperation. Surveillance and interdiction might provide an effective barrier against pathogens that pose little threat of spread, such as the Ebola virus, but that would be like building two cages around a dangerous animal when one cage would do. How could such containment work for the more serious threats, such as a new sexually transmitted pathogen, a new AIDS virus? Such pathogens are generally asymptomatic or cryptically symptomatic during much of their infectiousness. Are we going to test each of the millions of international travelers for venereal infection and make them wait with immigration services until the results of their tests are available? The complete failure to control the spread of HIV into new countries during the last decade in spite of the clearest signs of the impending disaster reveals how hopeless such an approach would be. Experts on AIDS are currently arguing about whether HIV arose naturally through transfer from chimpanzees to humans, or whether medical activities, such as vaccination or reuse of contaminated syringes, played a critical role. If HIV arose naturally, it serves as a warning of the kinds of things that could happen naturally in the future. Yet even if HIV did arise from a chimpanzee virus without any help from medicine, there is a bright side: few new AIDS-like pathogens are likely to invade from some isolated group of humans because there are hardly any isolated groups of humans left on the planet. The recognition of the exaggerated threat from far-off places does come with a few caveats, however. One caveat involves the historical recognition that germs have entered human populations primarily from two sources. The first source is domesticated animals. Unless we start introducing pathogens from domesticated animals in new ways—such as through the transplanting of their organs—the threat from domesticated animals probably holds few new surprises. The second source is other primates. Our biological machinery has diverged evolutionarily from that of other primates more recently than it has from more distantly related species. If a germ enters a human from another primate, especially from another ape, the barriers to setting up shop will be relatively low. At the time of the transfer, the germ’s characteristics will have evolved to take advantage of that other primate; but because that primate is more similar biochemically to humans than, say, lions, we can expect a greater proportion of these transfers to take hold. The process is much like the differential settlement of North America. Immigrants did not settle the continent randomly but rather settled in places where the climate and topography was similar to their homeland. Scandinavians tended to settle in Minnesota, and Germans in Wisconsin. Those from the British Isles settled more heavily along the Atlantic coast. To some extent these differences depended on what was available, but that cannot be the whole story. Who would be more likely to say that Minnesota winters are not so harsh—an immigrant from England or an immigrant from Norway? Germs, of course, do not have the option of forethought; still, one can ask whether a germ that enters a human from a chimpanzee will find life in humans more harsh than would a germ from a lion. It’s no surprise that although African cats and African primates have retroviruses, we humans have gotten our retroviruses, the HIVs and the HTLVs, from other primates rather than from cats. It is not just the ability to infect and grow in humans that is important. It is also the ability to get out of a human and into the next human. Many germs have passed the first test but failed the second. The track record indicates that here, too, germs from other primates are more likely to become successfully established in humans. The vector-borne diseases that can perpetuate themselves indefinitely in humans—the malarias, yellow fever, dengue—have come disproportionately from other primates. Other vertebrates have made an occasional contribution—sleeping sickness from ungulates, Chagas’ disease from opossums, plague from rats—but these contributions are vastly less than would be expected if the contributions were proportional to the numbers of these other species. The greatest pool of closely related primates is in Africa, which also has its share of other potential sources, such as ungulates and rodents. We can therefore expect the dribble of germs that will enter and become established in humans to do so in sub-Saharan Africa more often than in other geographic areas. Rodents do seem to be sending pathogens our way, but many of these rodent pathogens do not persist in humans. Two examples familiar to North Americans are the bacterium that causes Lyme disease and the hantaviruses that cause Four Corners disease. Rodents are probably common sources for such diseases because they live in such close association with us and in such great numbers. Occasionally they cause terrible damage, as occurred with the black plague, but even that disease fizzled out in the human population. That the threat from far-off places is only minor does not mean, however, that we have nothing to fear but fear itself.*33\225\2*