中国深圳大学

By Sue Mueller & David Liu from? foodconsumer.org
Nov 15, 2008 – 2:13:45 PM

Why HIV vaccine fails

Dr. A. White of Duke University medical Center A published an article in the Sep 2, 2008 issue of Medical Hypotheses suggests that Merck’s V520 is destined to fail to prevent HIV infection in a recent trial.

Trial sponsored by Merck and the US government showed that the vaccine did not prevent infection in those not previously infected with HIV, nor did the vaccine reduce the virus load in those who did receive the vaccine.

As a matter of fact, those who received the vaccine were actually much more likely to become HIV positive, particularly among men who were also uncircumcised and had pre-existing immunity to adenovirus type 5, which was used as a carrier for the vaccine.

Dr. White said vaccines prior to V520 were intended to evoke strong anti-body-mediated immune response to prevent HIV virus from entering host cells. ? V520 however was meant to evoke a cell-mediated immune response to HIV, allowing HIV entering cells and then trying to conquer it in the infected cells.?

According to Dr. White, these two types immune response, antibody-mediated for extracellular infections and cell-mediated primarily for intracellular infections work in a teeter-totter manner. ? When one is suppressed the other is activated.?

V520 was well intentioned, White said. ? HIV quickly infects host cells right after entering the body, and a strong cell-mediated response is required to defeat the HIV virus.?

The problem, it seems to dr. White, is that the antibody-mediated immune response triggered by V520 suppressed the ability of the body to have the cell-mediated immune response that is needed to protect against HIV creating a window of opportunity for HIV infection. ? This is particularly the case for those who had exposed themselves to the adenovirus vector.

Dr. White acknowledged that the immune system uses antibodies to indentify extracellular pathogens, also said that it uses transfer factors to label infected host cells.

White suggested that “HIV-specific transfer factors could prove extremely useful, far more useful than vaccines, in preventing and treating HIV infections.” as hundred of studies indicated that pathogen -specific transfer factors can be used to stimulate the cell-mediated immune response against viruses. (by David Liu)

Bone marrow transplant cures man of AIDS??

Doctors in Berlin said a man was cured of AIDS after he received bone marrow transplant from a donor naturally resistant to HIV virus. ?? The man had been negative for HIV for nearly two years ever since the treatment.??

But the experts quickly warned that the treatment is not feasible for most AIDS patients or HIV carriers because for one thing donors with the genetic mutation that may be responsible for the miraculous cure are rare. ??? Only one in every 1,000 Europeans and Americans may carry the desirable mutation.

Other obstacles to successfully receiving the procedure are high risk of dying from the procedures itself. ?? Studies showed 20 to 30 percent of patients die from bone marrow transplant because the sick bone marrow needs to be killed by high doses of radiation and or medications.

Even if some people can find a HIV-resistant donor and be able to survive the procedure, bone marrow transplant is too costly for millions of HIV carriers and AIDS patients who live in Africa where the disease is most commonly seen.

The 42-year-old man suffered both leukemia and HIV. ?? Ever since he received the transplant at Berlin’s Charite clinic two years ago, he had been free of HIV virus as tests on the man’s bone marrow, blood and other organ tissues had been all clear.??

Scientists believe the mutated gene of concern, called Delta 32, prevents HIV from attaching itself to cells by blocking a receptor called CCR5.???

But doctors are not so sure if the man was cured because of the genetic mutation in the donated bone marrow. ?? But theoretically, knocking out the receptor by a gene therapy may be a future treatment for AIDS, Professor Andrew Sewell, University of Cardiff, was cited by BBC as saying.

This German case is an exceptional, said a health observer. Previous reports showed that bone marrow transplantation could be more likely to spread HIV than cure AIDS. (by Sue Mueller)

Vitamin C inhibits replication of HIV

S. Harakeh and R. J. Jariwalla at Linus Pauling Institute of Science and Medicine in Palo Alto, CA has done quite some research on the inhibitory effect of vitamin C on HIV replication and found that this vitamin along with other reducing agents may be used as a treatment to reduce the virus titer.

In a report published in the Dec 1991 issue of American Journal of Clinical Nutrition, Harakeh and Jariwalla said they tested calcium ascorbate and two thiol-based reducing agents (glutathione and N-acetyl-L-cysteine (NAC)) for their effect against the human immunodeficiency virus HIV-1 replication in chronically infected T lymphocytes.

They found that calcium ascorbate has the same magnitude of effect at reducing extracellular HIV reverse transcriptase as ascorbic acid or vitamin C does. But chronic exposure to ascorbate was necessary for HIV suppression. ? NAC, but not glutathione caused less than twofold inhibition of HIV reverse transcriptase and rendered a synergistic effect (about 8-fold inhibition) when tested together with vitamin C.

Later in 1994, the researchers published another study in the June 1994 issue of Chem Biol Interact saying that “the activity of an HIV LTR-directed reporter protein made in ascorbate-treated cells was reduced to approximately 11% relative to that of untreated control,” indicating that vitamin C “exerts a posttranslational inhibitory effect on HIV by causing impairment of enzymatic activity.”

In 1995, Harakeh and Jariwalla reported in the Sep-Oct issue of Nutrition that “exposure to 300 micrograms/ml ascorbate resulted in approximately 5- to 10-fold lowering of the extra-cellular RT (reverse transcriptase) titer. In contrast, no significant suppression in extracellular RT levels was seen with concentrations of AZT (an antiviral drug) in the range of 1-5 micrograms/ml.” (By David Liu)

Posted by Desiree Everts? from cnet.com

Reporters were put into a frenzy this week when Google announced it was set to launch version two of its mobile search application for the iPhone which included the addition of voice-powered search, allowing you skip the keyboard altogether. But now the question is, where is it?

My colleague Josh Lowensohn reported on the application on Thursday, and duly noted on Friday afternoon that it still wasn’t available in Apple’s App Store. But as of Saturday afternoon, the application was still MIA. A search on the App Store returned only the older version of the Google Mobile App.

According to The New York Times, Google planned to release the free application through the iTunes Store “as soon as Friday.” The application, an update to Google Mobile App, is meant to allow you to talk into your phone, ask any question, and the results of your query will then be offered up on your iPhone.

One reason for the delay could be that it has been bogged down by Apple’s App Store approval process, which can take days or even months. Indeed, the Google Earth app for the iPhone took several days to appear in the App Store after its release. And Buzzd CEO Nihal Mehta noted that it took three months for his company’s application to arrive in the App Store after it had been submitted. In other words, it’s difficult for third-party developers to determine exactly when the application is going to be made available.

Perhaps from now on, when developers release an iPhone app, they’ll learn to add a caveat that while the application has technically been released, it may take several days or even longer for it to actually show up in the App Store.

Economic summit in Washington is likely only a first step to new rules to prevent financial meltdown and market mayhem.

WASHINGTON?(CNNMoney.com) — World leaders convened Saturday for a second straight day hoping to tackle a financial crisis that has ricocheted across the globe and left the United States and other countries on the brink of deep recessions.

Their goal: to prevent a similar calamity from happening again.

The historic two-day summit meeting, which brought together prime ministers and presidents from Group of 20 countries, was getting in full swing Saturday following an extravagant working dinner at the White House.

“We are here because we share a concern about the impact of the global financial crisis on the people of our nations,” Bush said Friday night. “Billions of hardworking people are counting on us to strengthen our financial systems for the long term.”

Bush said the conference participants would aim to figure out what caused the global crisis and assess government responses to it. The summit would also identify regulatory reforms and launch a “specific action plan” to implement them, he said.

Bush is expected to make a statement at about 3 p.m. ET on the findings of the summit.

Still, the expectations for the talks remain low.

In the days leading up to the summit, speculation abounded that leaders would accomplish little else but narrowing the focus for future talks – likely to be held in the first few months of 2009 after U.S. President-elect Barack Obama is sworn into office.

Bush, who offered to host the meeting nearly a month ago, echoed those exact sentiments in remarks made earlier this week. The imminent change in power at the White House has led many to believe that could also hamper any progress.

Attendees of the summit include leaders from such nations as China, Brazil, Saudi Arabia and Japan.

The pace of the world’s financial problems – rooted in large part in the collapse of housing prices and risky lending and borrowing – have accelerated in recent weeks.

The Organization for Economic Cooperation and Development, an international group based in Paris, said this week that the gross domestic product for its 30 members was likely to fall by 0.3% in 2009.

Major indexes around the globe have fallen off a cliff over the last two months. The Russian stock market has lost 65.5% of its value since the start of the year. Stocks in Japan and the United States have been equally hard hit, falling 42% and 33%, respectively.

Some countries have nearly collapsed under the weight the economic crisis.

In Europe, the pain spans countries of all sizes.

The 15 nations that share a common currency – the euro – said this week that their economies are in recession. Germany, Europe’s largest economy, is suffering.

In Iceland, where the government intervened to save the banking system from total failure, inflation is running at a painful 12.1% while economic growth has nearly flatlined.

Central bankers and government officials, hoping to halt the contagion, have taken unprecedented steps in recent weeks.

Britain, France and the United States have bought ownership stakes in banks and pumped them full of capital in the hopes of unlocking frozen credit markets. Earlier this week, China unveiled a massive, $585 billion economic stimulus package to try to keep its once red-hot economy moving forward.

With the crisis showing no signs of abating, several leaders have been trying to advance an agenda for the talks, which some observers have referred to as “Bretton Woods II” – a nod to a similar global economic summit held in July 1944 to reverse some of the painful trade and foreign exchange policies enacted in the wake of the Great Depression.

There have been calls, for example, to create a global accounting standard to replace the current mark-to-market standard, which some have blamed for the billions of dollars of losses suffered by banks.

Credit rating agencies and hedge funds have also become a target. French President Nicholas Sarkozy, who has embraced a hard-line approach toward regulation, has publicly said he is in favor of greater oversight of both industries.

And there has also been speculation that additional countries could enact economic stimulus packages of their own in the wake of the talks.

But what is expected to remain front and center is the subject of regulation and how to best modernize the global financial system for the 21st century.

One approach could involve granting greater powers to the Financial Stability Forum, which represents central bankers and regulators, or the International Monetary Fund, which has played a large role in recent weeks helping to bail out struggling countries.

Another possibility could involve the creation of a college of regulatory supervisors that would exchange notes about some of the trends and risks they are seeing within their own borders.

Welcome to WordPress. This is your first post. Edit or delete it, then start blogging!