Stories tagged Life Science

Jun
17
2005

Yesterday, an advisory panel for the Food and Drug Administration (FDA) recommended approval of a drug, BiDil, for heart failure in African-Americans. (The approval was unanimous, although two panel members voted against the racial indication labeling for the drug.) If the FDA follows the panel's advice, BiDil will become the first drug approved for use by patients of a particular race. The drug is a combination of two generic drugs (isosorbide dinitrate-also known as nitroglycerine-and hyrdralazine) that works by increasing the body's concentration of nitric oxide, which widens the arteries and helps the heart function more efficiently. The drug was tested in 1,050 African-Americans last fall. In that study, patients taking BiDil had much better survival rates and were much less likely to be re-hospitalized for congestive heart failure. Dramatic outcomes like this are a good thing, right? Yes. But the idea that a drug be approved for patients of a specific race makes many doctors uncomfortable, and it may also be bad medicine. Jonathan Kahn, a law professor and medical ethicist at Hamline University, said:

"It sends the message that because [the study] was done only in African-Americans that somehow African-Americans are different genetically than everybody else. And that is a very dangerous message to be sending. It's one that doesn't need to be sent in order to bring this drug to market."

Some cardiologists think the reason the drug works so well for many African-Americans may not be a matter of "race" (for which there is no scientific/genetic basis), but is probably related instead to the root cause of their heart failure: African-Americans are more likely to suffer heart failure due to high blood pressure, while whites are more likely to suffer heart failure due to clots caused by heart attacks or atherosclerosis. But some African-American patients do suffer heart failure caused by clots or hardening of the arteries, and some white patients do have heart failure related to high blood pressure. So critics think that the drug should be labeled for use by patients with heart failure caused by hypertension, instead of use by African-American patients. Dr. Gail Christopher, co-chair of the National commission on Health, Genomics and Human Variation, says:

"It would be 'bad science' to label or market this drug as a 'Black' drug. More importantly, race-based claims are not credible in the face of modern genetic medicine."

The New York Times says:

"The drug's maker, NitroMed Inc., says its decision to test and market BiDil as a drug for African-Americans is based on solid science. But BiDil's application [for FDA approval] has engendered controversy, with many scientists convinced that race is too broad and ill-defined a category to be relevant in determining a drug's approval, especially since geneticists have failed to identify a biological divide separating one race from another. Scientists know that different people have different responses to medications, and in some cases these have been linked to race. The FDA, for example, has said that people of Asian ancestry are more likely than others to get serious side effects from the cholesterol-lowering drug Crestor. But research shows that the underlying genetic variations across races are small. [Studies have shown that genetic variation within any racial group exceeds that between two groups.] Scientists believe that genetic markers will someday be found that explain the different reactions to drugs, but for now, race or ethnicity is an imprecise shortcut. By approving BiDil, the FDA would go well beyond where it has in the past in using race as a category to evaluate which patients respond to drugs."

Other doctors feel that failing to take race into account when treating patients is unacceptable. Dr. Jim Kennedy, a spokesman for the Royal College of GPs, told the Times:

"To close one's eyes to colour is tantamount to a neglect of clinical duties. As a practicing professional, I took an oath not to pay any attention to a patient's race, creed, colour or background, and I take this very seriously. But if there is real evidence that because of your genetic inheritance you should be offered a certain drug, I would be negligent in not offering it to you. There may be people of African descent who will benefit from ACE inhibitors, but trying to guess what genes someone has inherited in impossible. So doctors make a reasonable stab at a first-choice drug and if it doesn't work we'll use our second choice. I think it's far worse if, for reasons of political correctness, we chose to ignore real, hard scientific facts."

What do you think about the prospect of race-based medicine? Should drug companies be marketing to specific ethnic groups? How is this harmful or helpful?

Jun
15
2005

This would make a nice companion to Animal Grossology: scientists at the Monterey Bay Aquarium have discovered that a major source of food at the bottom of the ocean is -- are your ready for this? -- giant balls of snot. Apparently, some surface creatures spin webs of mucous, like spider webs. These get filled with debris and sink to the bottom, where they feed bottom-dwelling creatures.

All together now: ewwwww! Ick!

Jun
15
2005

I was once working on an exhibit about insects, and someone joked "You know what no museum has ever done? A fully-immersive, interactive mosquito exhibit!" To which I replied, "I've seen one. It's called July in Minnesota."

But as much as we pride ourselves on the Minnesota State Bird, the common mosquito, it appears Alaska has got it worse this year.

A winter of decent insulating snow, followed by early spring with no late frosts, basically created bug paradise. The jump start has put 2005 about three weeks ahead of schedule

Colder winters than Minnesota. Buggier summers than Minnesota. Who do these Alaskans think they are, anyway?

Jun
10
2005

The Avian Flu, or bird flu, is an infection caused by influenza viruses in birds. Wild birds worldwide carry influenza viruses but do not usually become sick from them. However, the same influenza virus that does not make wild birds sick can make some domesticated birds, such as chickens and turkeys, very sick and can kill them.

Scientists are closely monitoring an outbreak of avian flu in Asia. Avian flu has been found in birds in Cambodia, China, Hong Kong, Indonesia, Japan, Laos, Pakistan, South Korea, Thailand, and Vietnam. Human cases of avian influenza have been reported in Thailand and Vietnam, some of which have lead to deaths.

Organizations such as the World Health Organization and the Center for Disease Control are worried that the avian flu will become the next pandemic — an outbreak of an infectious disease that affects people over a large geographic area.

An influenza pandemic occurs when a new influenza virus emerges in people, causes serious illness, and then spreads easily from person to person worldwide. This is different from seasonal outbreaks of influenza. Seasonal outbreaks are caused by influenza viruses that are already in existence among people, where pandemic outbreaks are caused by new subtypes or by subtypes that have never circulated among people. Past influenza pandemics have been extremely costly. For example, from 1918 — 1919 the "Spanish flu" pandemic caused the deaths of more than 500,000 people in the U.S.

Many scientists and researchers believe it is just a matter of time until the next influenza pandemic. It is unlikely that a vaccine would be available in the early stages of the pandemic, and once a vaccine is developed it takes several months before it becomes widely available.

In order to be as prepared as possible for an influenza pandemic, the US Department of Health and Human Services has developed a Pandemic Influenza Response and Preparedness Plan. To view the plan, and to learn more about the avian flu, visit the US Department of Health and Human Service's web site.

Jun
01
2005

BirdLife International, a global alliance of conservation groups, has released its annual assessment of world-wide bird populations, and the news isn't good. 2,000 different species — more than one-fifth of the world's total — are either endangered or threatened with extinction. Humans are the biggest threat, either through destroying bird habitats, or by bringing pests and predators to new areas where they hunt defenseless birds. But humans are also the birds' best hope, if we can figure out ways to preserve these species before they disappear.

May
25
2005

In recent weeks, scientists have announced the discovery of not one, but two new mammals species:

Scientists describe new species all the time. But usually they're really small, like insects, or live in hard-to-reach places, like under water. New mammals are rare. These two species both come from remote jungle regions, and are shy, timid creatures that avoid humans.

Interestingly, both species were well-known to local people. So these species aren't really "new" — they're just "new to science."

Nov
08
2004

Jacqueline M. Kozisek of the University of New Orleans has been studying the fossil record to understand the history of the tropical honeybee. A specific species of honeybee, Cretotrigona prisca, can be found frozen in amber in rocks dated before and after the impact at the Chixilub that is thought to have wiped out the dinosaurs with a nuclear winter. If the climate changed dramatically enough to kill of the dinosaurs then how was this tropical honeybee able to survive through this time? Want to learn more?