Saturday, September 26, 2009

Does morphine cause bowel cancer?

Blocking signal molecule can prevent growth of large intestine and colon cancer. This is of relevance to heroin addicts. Don't laugh, but heroin (diamorphine) was orginally devised as a non-addictive form of morphine -- and that was achieved to some extent. It is not strongly physically addictive. The addiction is mainly psychological. But most heroin users will die of other things before they get bowel cancer

By seeing what substances and molecules affect the development of our diseases, we can develop drugs that prevent or cure diseases. In her dissertation at Kalmar University in Sweden, Ann Novotny has found that the signal molecule acetylcholine (ACh) is important for the progress of cancer of the large intestine and colon, knowledge that is important to factor in when developing drugs that block the effects of Ach on tumor cells.

Cancer of the large intestine and colon is the third most common cancer form in the Western world. Survival over a five-year period in Sweden is roughly 56 percent, but depends on how far the cancer has spread when it is discovered. It is known that the cancer has developed ways to signal in order to be able grow and spread independently of the regulatory systems of normal cells. In order to increase the number of survivors, it is important to map this signaling so that new forms of treatment for the cancer can be devised.

Ann Novotny studied the signaling used by the cancer in a portion of large intestinal and colon cancer. She found that there are receptors for opioids, such as morphine, on tumor cells. If morphine is supplied to these cells the protein urokinase is released, which the cancer cells can use to enhance their capacity to spread.

She also studied the nerve signaling molecule acetylcholine (ACh) and discovered that the cancer cells both build up and degrade the molecule. The study shows that the molecule is constantly released from the tumor cells and binds to a special receptor on the same cells, which leads to increased cell production as well as increased production of urokinase, which enhances the ability of the cancer cells to spread. These receptors can also be activated by nicotine, but also by the peptide SLURP-1 (secreted mammalian Ly-6/urokinase plasminagen activator receptor-related protein-1).

The levels of several enzymes, receptors, and the peptide SLURP-1 differ in early and late cancer of the large intestine and in healthy and diseased colons. This knowledge should help us develop drugs that block the effects of acetylcholine on tumor cells, which should be able to keep this cancer from developing further.


Small AIDS breakthrough: vaccine combination cuts HIV incidence a little

But useless for two thirds of the at-risk population. Full details of the research have yet to be released but the statistical significance of the difference reported looks dubious to me -- and we don't know if the study was double blind, though I assume it was

The experimental drug cut the risk of becoming infected with HIV by more than 31 per cent in the world's largest Aids trial of more than 16,000 volunteers in Thailand, researchers have announced. It is the first time in human trials that a vaccine has stopped the virus, which infects 7,500 worldwide every day.

Dr. Anthony Fauci, director of the United States National Institute of Allergy and Infectious Diseases, warned the development was "not the end of the road," but said he was surprised and very pleased by the outcome. "It gives me cautious optimism about the possibility of improving this result" and developing a more effective Aids vaccine, he said. "This is something that we can do."

"Today marks a historic milestone," said Mitchell Warren, executive director of the Aids Vaccine Advocacy Coalition, an international group that has worked toward developing a vaccine. "It will take time and resources to fully analyse and understand the data, but there is little doubt that this finding will energise and redirect the Aids vaccine field.

Even a partially effective vaccine could have a big impact. In 2007, two million died of Aids according to the United Nations agency UNAIDS.

Colonel Jerome Kim, who helped lead the study for the U S Army, which was also involved in the trial, said: "It is the first evidence that we could have a safe and effective preventive vaccine."

The Thailand Ministry of Public Health conducted the study, which used strains of HIV common in Thailand. Scientists stressed it is not clear whether the vaccine would work against other strains in the United States, Africa or elsewhere. The study tested a two-vaccine combination in a "prime-boost" approach, where the first injection primes the immune system to attack HIV and the second strengthens the response.

The vaccines are ALVAC, from Sanofi Pasteur, the vaccine division of French drugmaker Sanofi-Aventis; and AIDSVAX, originally developed by VaxGen Inc. and now held by Global Solutions for Infectious Diseases, a non-profit founded by some former VaxGen employees. ALVAC uses canarypox, a bird virus altered so it can't cause human disease, to ferry synthetic versions of three HIV genes into the body. AIDSVAX contains a genetically engineered version of a protein on HIV's surface. The vaccines are not made from whole virus — dead or alive — and cannot cause HIV.

Neither vaccine in the study prevented HIV infection when tested individually in earlier trials, and dozens of scientists had called the new one futile when it began in 2003. "I really didn't have high hopes at all that we would see a positive result," Dr Fauci confessed. The study tested the combination in HIV-negative Thai men and women ages 18 to 30 at average risk of becoming infected. Half received four "priming" doses of ALVAC and two "boost" doses of AIDSVAX over six months. The others received dummy shots.

All were given condoms, counselling and treatment for any sexually transmitted infections, and were tested every six months for HIV. Any who became infected were given free treatment with antiviral medicines. Participants were followed for three years after vaccination ended.

The results were that new infections occurred in 51 of the 8,197 given vaccine and in 74 of the 8,198 who received dummy shots. That worked out to a 31 per cent lower risk of infection for the vaccine group. The vaccine had no effect on levels of HIV in the blood of those who did become infected, providing "one of the most important and intriguing findings" of the trial, according to Dr Fauci, giving scientists important clues in identifying whether treatment drugs are actually make a difference by giving protection to the immune system. Full details of the $105 million study will be given at a vaccine conference in Paris in October.

This is the third big vaccine trial since 1983, when HIV was identified as the cause of Aids. In 2007, Merck & Co. stopped a study of its experimental vaccine after seeing it did not prevent HIV infection. Later analysis suggested the vaccine might even raise the risk of infection in certain men. The vaccine itself did not cause infection. In 2003, AIDSVAX failed in two large trials — the first late-stage tests of any Aids vaccine at the time.

It is unclear whether vaccine makers will seek to license the two-vaccine combination in Thailand. Before the trial began, the United States Food and Drug Administration said other studies would be needed before the vaccine could be considered for public use. Also unclear is whether Thai volunteers who received dummy shots will now be offered the vaccine. Researchers had said they would do so if the vaccine showed clear benefit — defined as reducing the risk of infection by at least 50 per cent.

The study was done in Thailand because US Army scientists did pivotal research in that country when the Aids epidemic emerged there, isolating virus strains and providing genetic information on them to vaccine makers. The Thai government also strongly supported the idea of doing the study.


Food crazies harassing businesses

Chicken, fake and real, looks to be a target of several consumer and nutrition groups. The Center for Science in the Public Interest is acting as co-counsel on a lawsuit filed Thursday by an Arizona woman accusing Quorn Foods Inc. of not disclosing on labels the fact that some people have serious allergic reactions to the main ingredient in its Quorn line of meat substitutes. Quorn is derived from a protein-rich fungus, which the company grows in large vats.

The fungus, Fusarium venenatum, was discovered growing in a field in Buckinghamshire, England, in the late 1960s and developed as a food product. "In the 1960s, people were concerned that we would run out of protein and started a search for new protein sources that could feed the world and discovered this fungus that grows naturally in soil. It makes a delicious and nutritious meat alternative. It has as much protein as eggs and as much fiber as broccoli on an ounce-per-ounce basis," said David Wilson, managing director of Quorn, which is a division of Marlow Foods, a British company.

He said the lawsuit was frivolous and unwarranted. "Quorn has been in the U.S. market since 2002 and has been enjoyed by millions of Americans. We have developed our labeling with the Food and Drug Administration, and it is accurate and fair," Wilson said.

But the center, a Washington-based nonprofit food safety and nutrition watchdog group and a vocal critic of restaurant chains that offer salt- and fat-laden foods, disagrees. It said that more than 1,000 people have reported suffering from nausea, vomiting and diarrhea after eating Quorn's products, which include Chik'n Nuggets, Chik'n Patties, Chik'n Tenders and various Chik'n cutlets.

According to the lawsuit, Kathy Cardinale, a 43-year-old advertising executive, ate Quorn's Chik'n Patties on three occasions in 2008 and became "violently ill" each time. The lawsuit, which seeks class-action status, was filed in Superior Court in Stamford, Conn. The British company has its U.S. offices in Westport, Conn.

Meanwhile, the vegan-oriented Physicians Committee for Responsible Medicine says it is readying a lawsuit against the giant KFC fast-food chain under California law for failing to warn consumers that the chain's new grilled chicken product contains a carcinogen. [Lots of things are carcinogenic if you consume enough of them. The toxicity is in the dose. And giving rats huge doses of stuff is a common but scientifically disreputable way of branding something as a carcinogen. The food freaks commonly use that tactic]

The anti-meat advocacy group said that it commissioned independent laboratory tests that show that KFC's grilled chicken contains PhIP, a chemical that it said can increase a person's risk of developing cancer even if consumed in small amounts.

Not disclosing the presence of the chemical violates California's public health law, known as Proposition 65, the group contends. It plans to file the lawsuit next week in San Francisco County Superior Court.

Earlier this year, the group sued hot dog makers, alleging that their products increase cancer risk and should carry a warning label similar to those on tobacco products.


1 comment:

John A said...

"Center for Science in the Public Interest" - little or no science, and as for the public...

Hey CSPI, I am allergic to peas, how about warning labels on all products containing them?