Booster Shots

Oddities, musings and news from the health world

Category: blood

Experts debate lifting blood donation ban on gay men in stable relationships

May 27, 2010 |  9:53 am

Men who have sex with men are not permitted to donate blood in the United States, Canada and many other countries. This ban was designed to stop the spread of HIV through blood transfusions and was implemented with broad support in 1983.

Blood But times have changed, and the rule no longer makes sense, say experts in HIV research writing in the current issue of the Canadian Medical Assn. Journal. The ban on donations from gay men was necessary early in the HIV epidemic when there was no way to screen for HIV antibodies in blood and the disease was appearing largely in that group.

But rigorous screening tests now exist, and rules permit people in stable, monogamous relationships to donate blood even though HIV infection now occurs in a broad swath of people, both homosexual and heterosexual. "...donors who have had heterosexual unprotected sex with multiple partners are not necessarily prevented from donating, provided the heterosexual donor claims to be aware of the sexual background of each of his or her sexual partners," the authors wrote.

Similarly, gay men in stable, long-term monogamous relationships should be allowed to donate blood after a deferral period -- a waiting period -- of one year, the editorial states. Allowing this group to donate would increase the blood supply while not significantly endangering it. They estimate that allowing gay men to donate after a one-year deferral period would result in a risk of HIV in one unit of blood for every 11 million units collected.

The ban on donations from gay men is a matter of growing controversy. Both the HIV Medical Assn. in the United States, the American Red Cross and the American Assn. of Blood Banks has expressed support for a change in rules to allow donation after a deferral period.

"The current policy is counterproductive in terms of loss of donors, loss of good will, student protests, donor boycotts and lawsuits, among other negative effects," the authors wrote.

-- Shari Roan

Photo credit: Julie Markes  /  For The Times

Fake blood, real benefits

December 16, 2009 | 11:01 am

Blood drives may someday become a thing of the past.

Scientific efforts to engineer artificial blood components took two big strides forward this week. On Monday, researchers from UC Santa Barbara and the University of Michigan published a study describing their synthetic red blood cells, which are capable of delivering medicine, oxygen or MRI contrast agents throughout the body.

RbcsThe “cells” were made by layering hemoglobin and other proteins on top of doughnut-shaped scaffolds made of a polymer called polylactic acid-co-glycolide, or PLGA. When the researchers were done, they removed the polymer core and found that their new structures were just as flexible as authentic red blood cells, allowing them to squeeze through tiny capillaries.

The fake red blood cells were biodegradable and biocompatible. When the researchers soaked them in a drug called dextran, the “cells” released the drug “in a controlled manner,” according to the study. It also worked for the anti-coagulant heparin.

Meanwhile, another group of researchers is using nanotechnology to develop synthetic blood platelets that could help the body stem blood loss arising from traumatic injuries.

Platelets are instrumental in forming clots, which halt the bleeding from routine cuts and scrapes. But the body doesn’t make enough platelets to counteract the heavy bleeding that can result from car crashes, bomb blasts and other kinds of trauma.

To help out, Erin Lavik of Case Western Reserve University in Cleveland and her colleagues used biodegradable polymers to make fake platelets. When inside the bloodstream, they attach to real platelets, producing bigger clots that stand a better chance of halting bleeding, whether internal or external.

Rats that were injected with the synthetic polymer stopped bleeding faster than untreated rats, according to a study published today in Science Translational Medicine. The degree of improvement depended on how quickly the platelets were administered, but rats that got the platelets before they were even injured stopped bleeding twice as quickly as control rats.

The artificial platelets also outperformed recombinant factor VIIa, which is currently used to control bleeding in operating and emergency rooms, according to the study.

The researchers said their ultimate goal is to design synthetic platelets that can be stored at room temperature and administered through an IV. That would make them especially handy for military medics, who currently have few good options for stemming blood loss due to roadside bombs and other violent attacks.

-- Karen Kaplan

Photo: These synthetic red blood cells are almost as good as the real thing. In some ways, they're even better. Credit: Nishit Doshi/UC Santa Barbara

What, exactly, is Actovegin?

December 15, 2009 |  5:20 pm

The drug made a media debut today when it was reported that Canadian physician Anthony Galea, who has previously treated Tiger Woods, is under investigation by the FBI for giving athletes performance-enhancing drugs.

According to news reports, Galea was arrested Oct. 15 by Canadian authorities – officials said they had earlier found human growth hormone, Actovegin and two other drugs in a medical bag in his assistant’s car. Actovegin, which is essentially calf’s blood extract, has been used in the treatment of circulatory disorders but has not been approved for sale in the U.S. by the Food and Drug Administration.

Actovegin isn’t really one of your known quantities – there’s no mention of it at the FDA website. By contrast, “human growth hormone” turns up more than 2,000 hits. It’s sold by Nycomed, a Swiss-based company. From the product description:
Actovegin® produces an organ-unrelated increase of the cellular energy metabolism. The activity is confirmed by measurement of the increased uptake and of the elevated utilization of glucose and oxygen. These two effects are coupled and they result in a rise of the ATP-turnover and thus in a greater provision of energy in the cell.

“We don’t have it on our books,” said Karen Riley, a media officer with the FDA. “It would have to go through an FDA approval process, and I don’t have any record of that product.”

One might begin to suspect that calf blood extract is another way of saying "snake oil," but wait turns up one hit – a recent trial related to polyneuropathy, or nerve malfunctions in the extremities. It was performed under Russian authority, in Kazakhstan.

Why is it on a U.S. site devoted to clinical trials? “I don't know, I was surprised to see it,” Riley said.

Want to find out if all your prescriptions pass muster? The FDA provides some guidelines here.

-- Amina Khan


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