The study, to be published in the Jan. 10 issue of the scientific journal Cell, amends 20 years of scientific claims that cGMP acts to prevent platelet aggregation.

While platelet aggregation helps minimize the loss of blood when injury occurs, it can also lead to clotting that blocks a blood vessel - a life-threatening condition called thrombosis that can cause heart attack and stroke.

"Viagra, by itself, probably is not sufficient to cause a heart attack in healthy people, but our research suggests that it may present a risk for patients with preexisting conditions such as atherosclerosis," said Xiaoping Du, associate professor of pharmacology and the study's lead author.

Du said he and his coworkers had not set out to investigate the cause of fatalities in Viagra patients when they began their research about five years ago. Rather, as a basic research scientist, he was hoping to illuminate the highly complex series of molecular steps that control platelet aggregation.

Platelets are disk-shaped cells that freely circulate in the blood. When a blood vessel is injured, the platelets form sticky surfaces, adhering to one another and to the damaged area to plug the hole.

Using recombinant DNA techniques, the researchers forced standard laboratory cells to manufacture two proteins key to platelet aggregation: one that helps the platelets clump together and stick to the surface of broken blood vessels, and another that activates the first. The genetic manipulation enabled the researchers to isolate and study the molecules that trigger these proteins.

Du focused on PKG, or cGMP-dependent protein kinase.

"It was accepted knowledge that cGMP, by stimulating PKG-catalyzed reactions in platelets, inhibits their clumping," said Du. To his astonishment, he and his colleagues found otherwise.

"When we put PKG into the recombinant cells, we found that we actually made the cells more adherent," Du said.

The results were so surprising that the researchers wondered whether there was something special about the laboratory cells that made them react differently. But tests in mouse and human platelets yielded the same results. Moreover, platelets from mice incapable of manufacturing PKG failed to aggregate as well as platelets from normal mice.

Reconciling their findings with earlier scientific evidence that cGMP inhibits platelet aggregation, the UIC researchers believe that cGMP initially causes platelets to clump to seal a wound, but later reverses to stop an excessive buildup of cells that might block a blood vessel. If a person were at risk of thrombosis - if, for instance, a damaged blood vessel were already narrowed - even the initial accumulation of platelets could be sufficient to cause a problem.

Since Viagra is known to work by inhibiting an enzyme that breaks down cGMP, and hence raises its level, Du and his colleagues tested the drug on platelets taken from normal donors. Alone, Viagra did not promote platelet aggregation, but it did so in the presence of a small amount of other compounds typically present when a blood vessel is damaged. In fact, Viagra caused the cells to clump at concentrations well below those achieved in patients prescribed the drug for erectile dysfunction.

An estimated 16 million men worldwide have taken Viagra.

Katherine Esposito, of the Center for Obesity Management in Naples, Italy, and colleagues conducted a study to determine if lifestyle changes designed to obtain a sustained and long-term reduction in body weight and an increase in physical activity would improve erectile function in obese men.

The men involved in the study received detailed advice about how to achieve a loss of 10 percent or more in their total body weight by reducing caloric intake and increasing their level of physical activity.

The researchers said, "Our data demonstrate that lifestyle changes, including a reduced calorie diet and increased exercise, improve erectile function in obese men and resulted in about one-third of men with erectile dysfunction regaining sexual function after treatment. This improvement was associated with amelioration of both endothelial function and markers of systemic vascular inflammation. Interventions focused on modifiable health behaviors may represent a safe strategy to improve erectile function and reduce cardiovascular risk in obese patients."

Christopher S. Saigal of the University of California echoed the researchers views, "At a time in which obesity has become a public health crisis, this study provides evidence of efficacy for what perhaps should be the first-line treatment for obese patients with erectile dysfunction. This treatment strategy produces many benefits for the patient if it is successful and incurs no untoward risk if it is not. Unfortunately, however, this is one treatment for erectile dysfunction that will not be accompanied by free pens, free notepads, and its own Super Bowl commercial."

Cardiologist Melvyn Rubenfire, from the University of Michigan Health System, said that erectile dysfunction can be a sign that someone has heart disease. "Erectile dysfunction is much more common in people who have cardiovascular risk factors. The critical message is that erectile dysfunction may be a very early sign of atherosclerosis or a risk for heart attacks, strokes and other problems," he said.

Rubenfire says that men should take action to prevent both conditions with changes in diet and exercise. "If you take a look at a population of men between 45 and 60, almost half of them may have erectile dysfunction. And if you look at those who have erectile dysfunction, lack of exercise, a high-fat diet and hypertension are all very common," he said. "Prevention is the key." Rubenfire wants to encourage men in this age group to practice a healthy lifestyle that includes regular exercise, a reduction of fat in one's diet, adequate amounts of fruits and vegetables, and receiving a regular health screening.

Rubenfire underscored the importance of seeking medical help for erectile dysfunction issues, saying that men should treat it as a potentially serious medical problem. The quick-fix of buying impotence drugs from the Internet is risky as heart disease may go undiagnosed. "They should talk to their doctors rather than just seeking information from the Internet, and they should never take medication from a friend or that they have bought online without a prescription," he said.

The new study adds weight to the theory that drugs used to treat impotency may be associated with an increased risk of optic nerve damage in men with a history of heart attack or high blood pressure, say the researchers, who added that doctors prescribing these drugs should warn patients of the potential risk.

The new findings were based on men attending a specialist eye clinic in the United States. Half the men had optic nerve damage, diagnosed as non-arteritic anterior ischaemic optic neuropathy (NAION). NAION is the most common form of optic nerve damage in older U.S. adults, with up to 6000 people developing the condition every year.

The patients in the study completed a survey about their lifestyle in which they were asked whether they had been diagnosed with heart disease or high blood pressure and if they had been prescribed Viagra and Cialis for erectile difficulties. The results indicated that men with optic nerve damage were no more likely to have taken impotency drugs, but men who had had a heart attack were 10 times more likely to have optic nerve damage if they had taken Viagra or Cialis. "We found a strong link between use of Viagra or Cialis and NAION in men with a history of heart attack," said researcher Gerald McGwin, from the University of Alabama at Birmingham. "We found similar results in men with hypertension that, while not as dramatic, are substantial enough to indicate that men with a history of heart disease should be warned of the risks of NAION before use of these medications."

The researchers speculate that the drugs may reduce the blood flow to the anterior optic nerve, resulting in tissue damage. The risk of NAION is elevated in those with vascular disease, as they are already more susceptible. The researchers added that any man who has suffered a sudden severe loss of vision, and is prescribed Viagra or Cialis, should inform their doctor immediately.

Pfizer, the company that makes Viagra, may become the target of lawsuits from men with impaired eyesight as a result of NAION. But Pfizer have stated that there were no reports of NAION in the trials of the drug carried out before it was licensed, and that a greater number of cases related to this type of drug would have been reported by now if the association was anything other than coincidental. The researchers believe this may be because doctors are not asking patients diagnosed with NAION whether they take Viagra or Cialis.

"[Looking] at all the different organ systems - the blood, the heart, the lungs, blood flow in the brain - there are hardly any negative side effects. In fact, just the opposite is true. There are beneficial effects for primary pulmonary hypertension, as well as for conditions such as heart failure and lack of oxygen in the heart," said Schwarz. "The only issue is that the data we have are from relatively short-term studies. Viagra has been on the market since 1998 and the other two PDE-5 inhibitors were approved by the FDA in 2003. Therefore, we do not have multi-year follow-up studies. On the other hand, the drugs have been on the market for several years now and there have been no reports of negative long-term effects."

The researchers said that while there were some differences among the three medications; they had many properties in common, working by limiting the activity of the enzyme phosphodiesterase-5, which is found in tissues and vessels of the penis, blood platelets, and smooth muscle of blood vessels. For the treatment of erectile dysfunction, the drugs' constraint of the enzyme's action results in increased levels of cyclic guanosine monophosphate (cGMP) and nitric oxide (NO), biochemicals that promote smooth muscle relaxation and increased blood flow in erectile tissue.

The study found that PDE-5 inhibitors can be effective in treating erectile dysfunction; even for those men who have diabetes, those who are older, and those who have co-existing reduced blood flow to the heart caused by plaque buildup in the arteries. "Since PDE-5 is found in smooth muscles of the systemic arteries and veins throughout the body, use of PDE-5i has been associated with various cardiovascular effects. The original intention was to develop PDE-5 inhibitors as a treatment for angina, chest pain that occurs when the heart is starved for oxygen," Schwarz explained. "As such, their effects on the heart appear to be all beneficial. Nitrates and other substances commonly used to improve blood flow and oxygenation to the heart muscle have a side effect that we call the 'steal phenomenon,' in which blood is taken away from underperfused (flow-restricted) areas to improve blood flow in normal areas. In contrast, PDE-5 inhibitors actually improve blood flow even in areas where there is a blockage of an artery, thereby having a protective effect on the heart muscle."

Whether erectile drugs might cause damage to the optic nerve was a matter of controversy when a suspected link between PDE-5 inhibitors and vision loss led to lawsuits filed last year against the maker of Viagra. According to the article's authors, however, "analysis of clinical trial data in more than 13,000 men and on more than 35,000 patient-years of observation" found occurrence of the visual disorder to be similar to that of the general population. "Even though individual cases have been reported for all PDE-5i, these recently published data do not suggest an increased incidence of non-arteric anterior ischemic optic neuropathy in men who took PDE-5 for ED," said the researchers.

Stroke was another bogeyman that the researchers laid to rest. Stating that, although the enzyme PDE-5 has been found in tissue and arteries of the brain, sildenafil does not appear to dilate cerebral arteries or have an effect on cerebral blood flow or blood flow velocity, an indication that there is no increased risk of stroke or hemorrhage. All up (no pun intended), erectile drugs got a glowing report from the researchers. "Experimental and human studies indicate that PDE-5 inhibitors are effective and well tolerated, and there is evidence that they are not being used to their utmost potential. We suggest that these drugs may prove beneficial in treating a wide variety of [non-erectile dysfunction] disorders," concluded Schwarz.

Writing about their research in the journal Human Gene Therapy, the researchers explained that unlike traditional gene therapy, the gene transfer approach they used does not change the DNA or genetic code of cells. Instead, small pieces of DNA reach the nuclei of cells and this causes them to increase production of particular proteins. These proteins help relax smooth muscle cells, the type of muscle found in the penis. When relaxed, the tissue allows the penis to fill with blood and become erect.

The new technique may provide an important alternative for the estimated 30-40 percent of men with erectile dysfunction who cannot take oral medications like Viagra. Encouragingly, a single gene transfer treatment provided erectile improvement that was maintained through the 6 months of study.

The men in the study ranged from 42 to 80 years of age, with around half suffering from diabetes or cardiovascular disease, both of which can interfere with the ability of smooth muscle cells to relax. The main aim of the study was to determine the safety and tolerability of the new therapy, however, the results also showed that at the highest doses, the men reported significant improvements in erectile function.

The treatment consisted of injecting DNA segments into the corpus cavernosum, the expandable tissue along the length of the penis that fills with blood during erection. The effectiveness of the treatment was measured using the International Index of Erectile Function scale, a questionnaire that is commonly used to measure erectile dysfunction. The men who received the highest doses had apparent sustained improvements in erectile function as measured by the questionnaire.

While the initial results from this small study are very encouraging, the researchers caution that a larger study, that includes a control group treated with a placebo, is needed to confirm the safety and effectiveness of the treatment.

Stanley wanted to have sex. He just couldn't. It was a feeling I understood all too well but at least I had the option of, ahem, taking matters into my own hands. Not so Stanley. Not only did he suffer the loss of masculine stature, he also suffered blue-balls every day of his hellish life. At the age of 19 I hoped and prayed I would not end up like Mr. Roper.

Erectile dysfunction (ED - a more accurate and medically forgiving term than "impotence") has likely been the bane of aging men for as long as we've had dicks. An Egyptian papyrus dated to 1700 BCE recommends a poultice of thorns and honey be applied to the penis as a treatment. King David famously suffered from ED in his declining years as have most men through the ages if they lived long enough. Accurate statistics are hard to come by given the embarrassment and shame associated with "not getting it up" but it's been estimated that by the time they reach Mr. Roper's age (55-60) most men will have had some experience with ED. A sizeable minority are, like Mr. Roper, unable to achieve an erection of any kind... ever.

Then as now, ED was a big problem. Status and sex are probably the two greatest desirables in a man's life and as Mr. Roper learned, "impotence" affects one's prospects for both. Accordingly, through the ages there have been many supposed cures. For the great bulk of human history this has taken the form of aphrodisiacs. Almost every culture at every time has developed some concoction that serves to enhance sexual vigor. Some of these were meant to be ingested, others applied topically. While some were (are) innocuous (various herbs and oils), a number were either disgusting (frog bones, monkey dung, nail clippings, semen, bat blood, menstrual blood etc.) or painful (cayenne peppers swallowed or rubbed directly on the penis). It would seem that the concept of "No-Pain-No-Gain" goes back a long way.

The efficacy of these folk cures is still subject to much debate. In fact, a new field of scientific endeavor called pharmacosexology was brought into existence to study the affects of such concoctions on both sexual interest and erectile function. Generally speaking, aphrodisiacs arose in two ways. The first was primarily associative. Anything that looked like a big raging hard-on (rhinoceros horn - any kind of horn really, carrots, bananas, bones, roots etc.) seemed a logical place to start. Then there were the genitals themselves, both of defeated enemies and of animals. Cave drawings depict prehistoric men munching on testicles and while the point of this practice is obviously speculative, studies of contemporary primitive societies suggest the purpose is at least to some degree, virilization. That is to say, the ingestion of the masculine essence of an animal or foe was thought to make the eater more masculine himself. While this may seem ridiculous to the modern observer it should be noted that the concept is alive and well in many parts of the world; the Far East in particular. In fact, the market for tiger's testicles has driven the South China tiger to the brink of extinction. While these putative aphrodisiacs may have had some nutritional value, by and large, they work about as well as one would expect. Erectile dysfunction is not, and has never been cured by the ingestion of something just because it a) looks like a dick/testicles or b) is in fact a dick/testicles.

Another class of aphrodisiacs was developed out of trial and error and these are likely to have had some physiologic effect. In this group we include such things as chocolate (used by the Incas), aniseed, figs, garlic, fennel, licorice, ginger, nutmeg, oyster, papayas, chili peppers, yohimbe (derived from the bark of a West African evergreen) and of course the infamous Spanish Fly (actually dried cantharide beetles). Research is ongoing into if and how these substances work. Some are thought to contain substances that either mimic the action of sex hormones or trigger their production. Aniseed (favored by the ancient Greeks and Romans), fennel and papaya for instance, have estrogenic effects. Molecules in yohimbe have demonstrated as affinity for androgen receptors and it is thought to stimulate testosterone production. An extract of yohimbe is, in fact, prescribed as a drug to treat erectile dysfunction.

Others like garlic and ginger have been found to stimulate blood flow and still others are believed to work by way of penile irritation. Into the later category we put cayenne pepper and Spanish fly.

Spanish fly is probably the best known aphrodisiac of all time. Ancient Assyrian tablets recommended its ingestion as a treatment for impotence. Nero's wife reportedly administered it to dinner guests in the hope of generating indiscretions which she could then use for blackmail purposes. Henry IV is believed to have taken it and it was reportedly slipped into Louis XIV's food so as to rekindle his interest in his mistress. Marquis de Sade did the same to guests at an orgy. While the sale of Spanish fly is illegal in the US and is restricted in most countries, it's still being sold on Ebay (in name at least).

Spanish fly is made from a beetle that secretes an acidic substance called cantharidin as a defensive agent. This stuff is toxic! When the body digests this beetle, the cantharidin is removed by the kidneys and excreted in the urine as an acid. Cantharidin causes irritation and burning wherever is passes, including the urogenital tract. In small enough doses this takes the form of swelling and itching, sensations associated with arousal. You get hot and bothered all right, just not in a good way. Cantharidin can cause kidney and gastrointestinal inflammation, even death is consumed in high enough quantities. While in proper doses it can induce an erection in both humans and animals, it's a much more effective poison than aphrodisiac. But for the bulk of human history there weren't a lot of options. If ingesting acid was what it took to restake your claim to masculinity, well, then that's what you did. At least until modern medical science jumped into the game. But that's a story for another week.

The supplement, called Prelox, is a blend of two circulation-enhancing ingredients. Pycnogenol (the bark extract), which helps keep blood vessels dilated for optimal blood flow, and L-Arginine, an amino acid.

A study that reviewed the effects of Prelox found that it caused a markedly increased nitric oxide production, the key mediator involved in expanding arteries for elevated blood flow during erections. Conducted by the Medical University of Sofia, Bulgaria, the researchers involved said that by the end of the study, all men taking Prelox experienced almost a 100 percent increase of orgasmic function, sexual desire, intercourse satisfaction and overall satisfaction.

Blood analysis revealed an increased testosterone level during supplementation with Prelox. This is not a direct result of the supplement but is typical for men with increased sexual activity. The men in this trial reported a dramatic increased frequency of morning erections. Moreover, their partners noted a higher interest for sex as well as better performance.

Past research on Prelox indicated its effectiveness in increasing and enhancing sexual performance in three clinical studies in the United States and Europe. In these studies, almost 85 percent of Prelox users said it improved erectile function and more than 70 percent of Prelox users said it was easier to initiate and sustain an erection. In a study at the New York University School of Medicine, more than 80 percent of male subjects rated Prelox as effective in improving their ability to engage in sexual activity.

The exercises are referred to as "natural" as no external devices or equipment are involved. Two hands, some kind of lubricant and some spare time each day are all that is required. The technique has spawned a large number of tutorials, guides and programs - mostly Internet based - designed to assist men in implementing the exercises. Likewise, communities of jelqing devotees exchange messages in forums updating each other on their size gains and their own custom-developed exercises. No doubt because of the low cost involved, jelqing has become the most popular penis enlargement method in America.

The most comprehensive research into the effectiveness of jelqing was carried out in the late 1970s by Dr Brian Richards in the United Kingdom. His research was accepted for publication by the British Journal of Sexual Medicine and showed positive results for 87 percent of the test group. The results from his study showed an increase in penis length of up to 1.4 inches and an increase in penis girth of up to 1 inch.

The workouts themselves are based around a daily jelq session of around 10-30 minutes. The exercises usually start with a penis warm-up, which involves a warm bath or a towel soaked in warm water applied to the penis. The warm-up is to increase blood flow to the penis and prepare it for the jelq exercises. Once the warm-up is completed, the jelq techniques can be commenced. Jelqing should only be attempted with a semi-tumescent (semi-erect) penis, never on an erect penis. Some lubricant should be applied beforehand and the hand-grip should completely encircle the base of the penis thus ensuring that no blood escapes from the penis. The penis is then milked, with the hand moving towards the head and forcing the blood toward the end of the penis. The average workout usually consists of around 100-200 jelq movements.

The exercises can only be carried out in a semi-tumescent state as a flaccid penis will render the exercises useless and an erection will render them impossible. Ejaculation should not be allowed to occur and if the urge becomes apparent then a break from the exercises is recommended. Likewise, jelqing should be ceased should any pain or discomfort become apparent. After several months, penis size increases, both in girth or length should become apparent and long-time practitioners claim gains of several inches in length are possible.

Please note that the above example of a jelqing workout is intended for overview purposes only. To avoid possible injury, men interested in jelqing should review detailed instructions, background information, videos and pictures of the exercises before starting. Like any exercise, it must be done properly.

Most websites offering subscriptions to programs and tutorials about jelqing techniques charge around US$40-US$50. One of the better websites for effective jelqing material is the Penis Advantage website managed by Roger Miller. Miller says the key to his website's success is the range of condensed exercises they offer. "Other penis enlargement websites demand an hour or more a day for exercises. This is why many men fail to complete jelqing programs, there's simply too much time required. One of the options we offer is a condensed jelqing program that requires only 8 minutes per day. Men have no problem allocating 8 minutes per day and that's why our success rate is so good," said Miller. He also stressed the importance of support. "Men always have questions about the exercises. We answer all emails from members within 24 hours, that way, members don't find their exercise program disrupted while they are waiting for an answer."

Using a special transdermal patch is the latest method being promoted to enlarge the penis. Transdermal patches themselves are not a new invention and have been used for delivering all sorts of drugs – from nicotine to testosterone – for years. The advantage of transdermal patches is that the drug is delivered directly to the bloodstream, rather than via the digestive system. Additionally, the drug is released slowly over a longer time period, often several days. This makes transdermal patches an effective way to deliver drugs in controlled amounts in a continuous manner. The drugs or adhesive contained in transdermal patches can cause skin irritation. This can be exacerbated by sweating which may also cause the patch to loosen. Patch location should consequently be varied to avoid problems with skin irritation.

Thanks to : Penis Stretcher