Tag: HIV & AIDS

Genetically Engineered T-Cells Rescue Another Leukemia Patient

By Breanna Draxler | December 10, 2012 3:41 pm

Leukemia cells.

A cancer-treating technique being studied at the University of Pennsylvania has had dramatic results for some of the patients involved. Thanks to an experimental leukemia treatment the team first tried last year, 7-year-old Emma Whitehead is now in remission, the scientists have reported at a meeting of the American Society of Hematology this week. She is one of a dozen patients that have undergone the treatment; a third of those patients are now cancer-free.

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CATEGORIZED UNDER: Health & Medicine, Top Posts

Nanofibers: A New Platform for Protecting Against HIV and Pregnancy?

By Breanna Draxler | December 5, 2012 11:21 am

Nanofibers can physically block sperm, as shown here. The fibers can also release spermicide and other chemicals.

In theory, it shouldn’t be too difficult to protect oneself against HIV and other STIs, as well as pregnancy. Condoms, after all, are very effective. But in practice, it’s not so simple. Many of the people at high risk for HIV, for instance, are women who don’t have much control over whether their partners wear protection. Taking daily medication or applying drug-laden gels also have their downsides—people forget, they find it inconvenient, there’s social stigma. So finding ways to provide protection thats get over these hurdles is an important research goal.

Scientists at the University of Washington think a new delivery platform may be a step in the right direction. They’ve created nanofibers embedded with pre-existing drugs against HIV-1, HIV-2, and sperm. Theoretically, these stretchy microfabrics could be inserted into the vagina directly or on the surface of another device, such as a vaginal ring, and act as both a physical and chemical barrier. The real kicker is the fact that the nanofiber can release the drugs slowly, so the device could protect women against STIs for an extended period of time after insertion.

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CATEGORIZED UNDER: Feature, Health & Medicine, Top Posts

A Daily Pill Can Prevent HIV Transmission, Two Studies Show

By Valerie Ross | July 15, 2011 11:15 am

What’s the News: A daily dose of anti-HIV drugs can significantly reduce the likelihood that straight men and women will contract HIV from an infected partner, according to two new clinical studies. These studies add strong evidence to earlier findings that taking HIV drugs can prevent healthy people from contracting the disease, and are the first to show that the drugs reliably lower transmission risk in heterosexuals.

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CATEGORIZED UNDER: Health & Medicine

Promising Drug to Prevent HIV Fails in Trial–But It's Not Out of the Picture

By Veronique Greenwood | April 19, 2011 3:23 pm

UPDATE: The blood tests are in, and it looks like the women instructed to take the pills were not popping them. Only a quarter of those who got infected had any Truvada in their blood. This suggests that the problem isn’t the drug’s effectiveness, but rather compliance on the part of the population.

What’s the News: A much-anticipated trial in African women of an HIV drug found to be effective in preventing infection in men has washed out—researchers announced today that women taking Truvada were no more likely to evade HIV infection than women taking a placebo.

The result is especially disappointing because Truvada, which is an oral pill combining two drugs, emtricitabine and tenofovir disoproxil fumarate, has been shown to be 90% effective in preventing infection in gay men who took it religiously. Read More

CATEGORIZED UNDER: Health & Medicine

Gene Therapy for HIV Resistance Succeeds in Trials—But Hold the "Cure" Talk

By Andrew Moseman | March 3, 2011 4:10 pm

Earlier this week at a scientific conference in Boston, HIV researchers announced a remarkable success in countering the virus’ drain on the immune system. But this early step is far from a cure.

Why it’s exciting:

Carl June and colleagues tested six male patients who already had HIV and were taking a standard antiviral regimen. Like many HIV patients, the drugs helped them, but their counts of immune cells stayed low. June’s team tested a therapy created by Sangamo BioSciences in Richmond, California, that alters a patient’s actual white blood cells to make them more HIV-resistant.

Researchers removed a sample of CD4+ T cells, the type of immune cells affected by HIV, from each man and used Sangamo’s enzyme to disrupt the CCR5 gene, which encodes a protein that HIV uses to enter CD4+ cells. The engineered cells were then infused back into the patients. Immune-cell counts subsequently rose for five of the six patients who received the therapy. “It’s very exciting,” says John Rossi, a molecular biologist at the City of Hope’s Beckman Research Institute in Duarte, California. “If they did this several times in a given patient, you could establish a high percentage of resistant cells.” [Nature]

The idea came from the “Berlin Patient,” who we’ve written about before at 80beats. He became famous after receiving a donation of bone marrow from someone who carried a mutation in CCR5 that made them resistant to HIV.

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CATEGORIZED UNDER: Health & Medicine

Cutting Through the Hype Surrounding One Man's HIV "Cure"

By Andrew Moseman | December 15, 2010 2:08 pm

HIVbuddingPerhaps you’ve seen the story of the 44-year-old American man reportedly “cured” of HIV in Germany–it’s been making the rounds over the past week. What’s actually happening here?

The Procedure

This is a story that dates back a few years; in fact, 80beats blogged about this case years ago when it first made the news. Back in 2007, the man—Timothy Ray Brown—was an HIV-positive patient suffering from acute myeloid leukemia. When standard chemotherapy couldn’t help him, his docs in Germany turned to a bone marrow transplant, with one twist.

Brown’s oncologist decided to look for a bone marrow donor who had a had a special genetic mutation that made the stem cells in it naturally resistant to HIV infection. His physician, Dr. Gero Huetter, was able to find this rare match and Brown got the bone marrow transplant.  He needed a second stem cell transplant because the cancer came back. Today, he appears to be cancer free and doctors can’t find traces of the virus that causes AIDS either. [CNN]

Brown’s treatment made a splash in the news in 2008, when the doctors first reported on it. It has resurfaced this month because the researchers published a new study in the journal Blood updating his condition.

The researchers confirmed that Brown seems to have maintained his resistance to HIV for three years, confounding their expectation that he would become reinfected. They concluded that a “cure of HIV has been achieved in this patient.” [New Scientist]

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CATEGORIZED UNDER: Health & Medicine

Animal Testing Advocate Gets "AIDS-Tainted Razor Blades" in the Mail

By Jennifer Welsh | November 24, 2010 12:01 pm

razor-bladesA neuroscientist who has spoken out in support of animal testing is in the news again after a militant animal rights group sent razor blades and a threatening note to his house. The group claims that the razor blades were contaminated with HIV-infected blood.

The researcher, J. David Jentsch, who studies addiction and schizophrenia at UCLA, explains the incident:

“About a week ago I was going through my mail in my kitchen and I opened a letter and razor blades spilled out on the floor. It was the first sign something was nefarious,” he said. “The letter inside contained quite specific and heinous acts of violence to kill me.” [CNN]

Jentsch made headlines last year when he staged a pro-test rally in support of (humane) animal research after an animal rights group fire-bombed his car in his driveway. The threats and harassment of Jentsch and other department employees have continued, but Jentsch seems undaunted and undeterred.

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CATEGORIZED UNDER: Health & Medicine, Living World

Once-a-Day Pill Reduces HIV Infections—Would People Actually Take It?

By Jennifer Welsh | November 23, 2010 6:59 pm

pillsA drug called Truvada seems to be able to prevent HIV infection from taking hold in the body when taken regularly. The once-a-day pill combines two anti-retroviral drugs, and was found to reduce new HIV infections in a study of 2,500 gay men. But there are two big issues: compliance and cost.

In the study, which was published in the New England Journal of Medicine, men who took the pill were 44 percent less likely to contract the disease than those on placebo. But when the researchers looked only at the men who took the pill faithfully, the number jumped to 90 percent.

“These results represent a major advance in HIV-prevention research,” says physician Kevin Fenton of the Centers for Disease Control and Prevention in Atlanta. “For the first time, we have evidence that a daily pill used to treat HIV is partially effective for preventing HIV among gay and bisexual men at high risk of infection.” Fenton cautions, however, that the results don’t warrant abandoning other proven prevention techniques. [Science News]

While the results are certainly promising, it remains to be seen if at-risk people would take a pill every day.

[M]any men in the study failed to take all their pills, and some clearly lied about it. For example, some who claimed to take them 90 percent of the time had little or no drug in their bloodstreams. Although the pills caused no major side effects in the study, some men disliked the relatively minor ones, like nausea and headaches. [New York Times]

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CATEGORIZED UNDER: Health & Medicine

Evolution Seals the Case Against a Man Who Knowingly Spread HIV

By Andrew Moseman | November 16, 2010 11:53 am

WhitfieldTreeAnthony Eugene Whitfield is currently serving a 178-year prison sentence for, among other things, knowingly infecting several sexual partners with HIV. But how do you prove that the women in question contracted the virus from him?

From Ed Yong:

To demonstrate Whitfield’s guilt, the prosecution had to show that he had wilfully exposed women to HIV, that his five HIV-positive partners contracted their infections from him. Fortunately, David Hillis from the University of Texas and Michael Metzker from Baylor College of Medicine knew exactly how to do that. They had evolutionary biology on their side.

Hillis and Metzker knew that HIV is a hotbed of evolution. The bodies of HIV carriers produce around a billion new virus particles every day, and their genomes change and shuffle at furious speeds. But when infections pass from one person to another, this viral variety plummets. Thousands of genetically distinct viruses might jump into a new host, but usually, only one of these managed to gain a foothold and set up a new infection. Every time it moves from host to host, HIV passes through a genetic bottleneck and that provides a massive clue about who passed an infection to whom.

For great detail on how the scientists built these HIV trees and used them in the case against Whitfield, as well as what it means for the future of prosecution, read the rest of this post at Not Exactly Rocket Science.

Related Content:
Not Exactly Rocket Science: Genetic Study Shows How HIV Controllers Get Their Groove
80beats: HIV’s Primate Precursor Is Very Old. Why Did It Jump To Humans So Recently?
80beats: Good News: Anti-Microbial Gel Cuts HIV Infection Rates for Women
80beats: New HIV Hope? Researchers Find Natural Antibodies That Thwart the Virus

Image: Scaduto et. al / PNAS

CATEGORIZED UNDER: Health & Medicine

AIDS-Fighting "HIV Controllers" Give Up Some of Their Genetic Secrets

By Andrew Moseman | November 5, 2010 12:27 pm

HIVbuddingFrom Ed Yong:

The vast majority of people who are infected with HIV go on to develop AIDS. Their bodies become riddled with the virus, their immune systems falter, and they are besieged by life-threatening infections. But not everyone shares the same fate. Around 1 in every 300 people infected with HIV carry genetic trump cards that allow them to resist and control the virus. These “HIV controllers” can live with the virus for years. They never develop AIDS and they live long, healthy lives, even if they never take any medication. Their genetic secrets are slowly being revealed.

Researchers studying thousands of people with HIV, some with the controllers and some without, found something surprising:

Amazingly, every single one of these variants sits within a specific part of our sixth chromosome, among a set of genes called class I HLA genes. The proteins they produce form part of the internal security checks that defend us from infections. They grab small pieces of other proteins from inside our cells and display them on the outside, waving them under the noses of passing T-cells. If the T-cells recognise these pieces as parts of bacteria, viruses or other foreign invaders, they tell the infected cell to self-destruct and set the immune system on red alert.

Check out the rest of this post at DISCOVER blog Not Exactly Rocket Science.

Related Content:
80beats: HIV’s Primate Precursor Is Very Old. Why Did It Jump To Humans So Recently?
80beats: Good News: Anti-Microbial Gel Cuts HIV Infection Rates for Women
80beats: New HIV Hope? Researchers Find Natural Antibodies That Thwart the Virus
80beats: Gene Therapy Hope for HIV: Engineered Stem Cells Hold Promise
80beats: Did the Eradication of Smallpox Accidentally Help the Spread of HIV?

Image: Wikimedia / HIV Budding

CATEGORIZED UNDER: Health & Medicine
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