I had never heard of CMV so the first step was to find out what it is. My Webster's version of Stedman's Medical Dictionary had this to say: A group of species-specific herpetoviruses infecting man and other animals and causing enlargement of cells of various organs and development of characteristic inclusions (see Note1) in the cytoplasm (see Note 2) or nucleus. Not particularly informative relative to the question, but a reasonable starting point; and the word "enlargement" is modestly suggestive. Step two was obvious, since I had no idea what I was being asked to add to. Read the article. I did and a summary follows:.
Angioplasty, a procedure whereby a slender tube with a deflated balloon at its tip is inserted into a blocked artery, the balloon is inflated, and the blockage is mashed against the artery walls, thereby opening them up to improve blood flow; is a pretty simple procedure. No anesthesia is needed, and the patient can often go home the same day. An angioplasty is obviously much less invasive than a heart bypass (coronary artery bypass graft, or CABG). However, this simple procedure fails 25-50% of the time (typically after a few weeks or months). For some inexplicable reason, the cells that line the artery walls of affected arteries grow at an excessive rate, and the blood flow is diminished again. This process, called restenosis, is much faster than arteriosclerosis itself - much like cancer, where damaged cells reproduce to eventually become cancer.
In 1992, a protein named p53, that affects cell growth, was isolated. It acts in one of two ways: 1) it slows growth of cells whose DNA has been damaged until it is repaired; or 2) it causes a cell with irreversible damage to commit suicide.
Cancer research has discovered that a cancerous cell contains an inordinately high level of p53. It seems that defective p53 can't do its job, so more is recruited. This has led to the conclusion that cancer cells are marked by high levels of p53. However, in some cases of cancer a normal level of p53 has been noted. How can that happen? Further investigation seemed to show that cancer, where there is an excessive but normal amount of p53; had been caused by interaction between the p53 and viruses, which rendered it ineffective.
A few years ago there were vigorous research attempts to link cancer to viruses, but with virtually no causal link found. However, there have been a number of more recent studies that suggested the existence of viral and other microbial links. For example, that Helicobacter pylori bacteria is somehow linked to ulcers, where for years "stress" was thought to be the cause. For some time now, a herpes virus (CMV) has been thought to possibly contribute to the acceleration of atherosclerosis in heart transplant patients, and more recently in atherosclorosis in the elderly who have long been known to carry CMV, but without complications except for those with a compromised immune system (like transplant patients, who receive drugs to suppress their immune systems).
The next discovery in this chain was that where excessive p53 is found in arteries, CMV is also frequently found. But just being present doesn't prove cause-and-affect. What triggers the reproduction of CMV? A heart transplant, for one. Normally, an invading body (CMV in this case) would be attacked by the immune system, but it "hides" inside of cells - undetected by the immune system (which is already degraded anyway). Angioplasty may be another trigger. It injures the artery walls, and in doing so may cause release of the hidden CMV, which is then free to reproduce.
So far, most of the studies have been done on rats - human studies are yet to come. There is; however, a race on among drug companies to develop anti-CMV drugs without serious side-effects, for eventual use against restenosis. But there is much work ahead before we can can even say, without reservation, that CMV causes restenosis, let alone to develop drugs to prevent it.
It is apparently too early to look for additional information on this issue - the existing work seems to be so preliminary that it hasn't been reported in medical journals yet. At least that I could find. And, since no references were provided, I assume that my assumption is correct. I will, however, continue to check the New England Journal of Medicine and JAMA (the Journal of the American Medical Association) for updates. (They are, I think, the most likely sources where data on this subject would be reported.)
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Note 1 - Inclusions - essentially, an invasion of the body - not resulting from trauma.
Note 2 - Cytoplasm - the substance of a cell, excluding the nucleus.
High protein diets, like in the "Zone," which recommends that your diet should contain 30% protein, are popular again, but they are not for everyone.
As reported in the July 1997 PENN STATE SPORTS MEDICINE NEWSLETTER, a new report from the National Cancer Institute suggests that a diet high in protein may cause liver damage. This report can be added to the previous finding that a high protein diet may cause kidney damage. Furthermore, a diet high in protein is likely to also be high in fat, with its plethora of health risks.
Here are some suggestions for healthy amounts of protein intake per day.
| Sedentary Adult | .36 (RDA) |
| Active Adult | .40 - .60 |
| Growing Athlete | .60 - .90 |
| Adult (strength tr) | .70 |
| Endurance Athlete | .90 |
A diet deficient in magnesium was found by a study originating from the Human Nutrition Research Center in North Dakota (the subjects were all women over 50), to have resulted in the finding that the subjects used 10-15% more oxygen to do a task than when their magnesium levels were adequate (as reported in the July 1997, PENN STATE SPORTS MEDICINE NEWSLETTER). It was estimated that 20-35% of the U.S.'s 50 and over population have a diet deficient in magnesium, which participates in the breakdown of fats and sugars. Some sources are green vegetables, legumes, and whole grains - also seafood. One conclusion from the study was that people's exercise levels are retarded on a diet low in magnesium.
On vitamin D and calcium - while it is true that we need vitamin D in order to absorb calcium (that's why milk is typically vitamin D fortified), it isn't necessary to eat only foods that contain both. Yogurt or cheese, for instance, are good calcium sources but contain no vitamin D.
When you eat yogurt, vitamin D already in your body (from other foods, vitamin supplements, or converted from sunshine) helps your body absorb the calcium. When calcium is ingested, the vitamin D in your body causes your intestinal wall to create "calcium-binding protein," which allows calcium absorption. The bottom line is to make sure that your diet includes both calcium and vitamin D, but not necessarily in the same food.
Does your treadmill get enough exercise?
According to the August 1997 issue of the TUFTS UNIVERSITY HEALTH & NUTRITION LETTER, research at the Medical College of Ohio has focused on polyphenols - chemicals in green tea. One (EGCG - you don't want to know what that stands for) inhibits an enzyme (urokinase), which ordinarily assists the growth and spread of malignant tumors. Theoretically, that action will retard the spread of cancer. In mice, urokinase blockage has been shown to decrease tumor size or cause remission altogether.
At Case Western University it has been found that EGCG, in conjunction with ECG (another green tea polyphenol), targets and destroys cancer cells. These two polyphenols, together, send messages for cancer cells to commit suicide.
The preliminary findings make green tea a possibly viable anticancer substance, as well as a possible cancer therapy weapon.
Green tea is common in Asia, but the U.S. has always used a preponderance of black tea - the green variety has not always been easy to find. However, the health claims for green tea have made it more popular, and now it is more commonly available - from Lipton, Twinings, Bigelow, Salada, and Celestial Seasons, among others. It is now available at many super-markets.
No, maybe it's "Antiquity of Fleas."
Adam
Had'm.
No, it must be "Reflection on the Meaning of Existance."
I
Why?
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I didn't realize it before undertaking this article on "fat" (technically called "lipids"), but there are more than one way of classifying them - just changing with the times, perhaps. Here is one. Lipids consist of: 1- Triglycerides (also called triacylglycerol or TAG); 2- Phospholipids; and 3-Sterols/Cholesterol.
Triglycerides are by far the most abundant type of fat, both in our bodies and in food; and are constructed of a glycerol and three fatty acid (FA) components.
An FA is, chemically, a hydrocarbon chain (carbon and hydrogen) with an acid group at the end. A fatty acid may be saturated or unsaturated. The difference, structurally, is that unsaturated indicates that there is still room for some hydrogen atoms in its molecular structure. Saturated FAs, on the other hand, have no room for additional hydrogen atoms. Saturated fats tend to originate from animal sources, but not exclusively - coconut and palm oils are among the exceptions; and they tend to be solid at room temperature. Unsaturated fats mostly come from vegetable sources, and are liquid at room temperature.
A specific type of FA, designated as "omega-3" (called "essential"), which includes EPA (OK, if you must know, it is eicosapentaenoic acid.) and DHA (docasahexaeonic acid). EPA and DHA come from oils in some cold water fish and marine animals, like halibut, cod, Albacore tuna, mackerel, mussels, sardines, salmon, and shrimp; and seems to have a positive effect on the heart.
The American Heart Association recommends a diet that includes two to three servings of fish per week; but not fish oil itself unless prescribed by a physician.
Phospholipids are structurally similar to triglycerides except that the third FA is replaced by a non-lipid compound which contains a phosphate group (a phospholipid). It is a unique fat in that it both attracts and repels water, unlike most fat which only repells water. As a result, phospholipids are an important part of both cell membranes and lipoproteins. They act as emulsifiers (see Note 3) to promote the mixing of fats and water (i.e., as in the bloodstream).
The best known phospholipid is lecithin. It is a natural ingredient in eggs, liver, soybeans, wheat germ, and peanuts. Phospholipids help fat-soluble vitamins and hormones pass in and out of cells. They also act as emulsifiers to help maintain fat suspension in blood, among other things. Lecithin is a major component of cell membranes, and the proper functioning of cells is dependant on the integrity of cell membranes. But no lecithin supplements are needed. The liver builds all that is needed; and it is, after all, fat. And you probably don't want any more of that than necessary.
Sterols (of which Cholesterol may be the most important example) form the third category of lipids. Sterols have a very different structure from other lipids in that they contain no fatty acids. They are, therefore, technically not fats, but act much like them, so they are categorized as such. Cholesterol is essentially the "father" of bile (an important participant in the digestion of dietary fat), vitamin D, and sex hormones (e.g., estrogen and testosterone). All are made from cholesterol.
In reality, we don't need any cholesterol in our diets. Our bodies manufacture, in our liver, all that we need. And, as most of you know, it is found only in animals, so when you see vegetable based foods with a "No Cholesterol" tag, you can be sure that it is just marketing "hype," or reassurance that no cholesterol was added in the manufacturing process.
Now that we have gotten a general introduction to fat/lipids, here are some specific details for discussion.
More on the "Fat Ferry" (lipoproteins) - since fat does not mix well with water, and the bloodstream is mostly water; how do we get fats diffused through the bloodstream into various parts of the body? Lipoproteins are the vehicle, they essentially provide a sack around fats, which allows them to ride through the bloodstream.
There are four types of lipoproteins:
Some people have been trying to eliminate fat from their diets altogether. NOT a good idea. They wreak cosmetic hazzards and health hazzards, but they also serve some very important functions in the body - we in fact, can't live without them. They provide an energy source, insulation and cushioning, they are a factor in vitamin utilization, form part of body membranes, provide satiety, and provide some essential nutrients. Fat as an energy source is explored next, with additional fat facts deferred to next month's Newsletter.
Fat is the primary source of fuel in the human body. Fats and carbohydrates (glucose) burn together at about a 50-50 ratio for most easy to moderate activities (including rest), but as activity (let's make it "exercise," since that is the real focus of this Newsletter) extends to an hour or more, as much as 90% of the fuel used comes from stored fat. Fat is the most used energy source in the body, and I guess that is why the "Designer" gave it a capacity for unlimited storage; unlike glycogen (storage form of carbohydrates), which has definite storage limits; and protein, which makes only a fairly meager contribution to energy production. Fat is energy-dense. Nine calories per gram, as opposed to only four for either carbohydrates or proteins. Clearly, the Designer's scheme is very efficient - too efficient, some would say. Early humans could appreciate the design; but, as life got easier, the idea of unlimited fat storage has gotten much less appreciated. And to add insult to injury, excess intake of carbs or proteins can be converted to and stored as fat, of course.
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Note 3 - Emulsifier - allows mixing of two liquids, like oil and water, that don't ordinarilly mix.
(Q) Should I be worried about dust mites? I hear about them all the time lately, and have seen some blown up pictures of them. They look like monsters from outer space, or prehistoric creatures, at least.
M.N.F., Union City, CA
(A) Unless you have asthma, they are harmless - don't bite or sting, or spread diseases. They can; however, be a major trigger for asthma sufferers, and not so good for those allergic to dust (and maybe not so much dust, but a component of dust mite droppings). This info via the September '97 issue of the U. of C. Berkeley Wellness Letter.
(Q) Does your body ever break down lean body mass to fuel aerobic exercise? If so, how do you prevent this from happening?
D.N., Cupertino,CA
(A) It can, but not if you observe a proper refueling habit. In the absence of glucose, your body can strip amino acids out of muscle protein, and create more glucose out of them. But this, again, takes unusual circumstances. If you eat regularly and include carbs, and refuel after long exercise sessions, your body will not cannibalize itself.
(Q) When I do abdominal exercises, my neck hurts. Any suggestions?
J.A., Los Gatos, CA
(A) For anyone who has neck problems when doing ab exercises, here is an easy solution without one of those ab gadgets that "everyone" is trying to sell these days. Interlock your fingers behind your neck (not behind your head) and crunch away. You still keep your neck in-line-with-your-spine (chin off of your chest). I think this position gives better neck support than the behind-the-head position, and even helps prevent the head rocking movement. Try it, and see if it works for you.
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