Archive for the ‘medicine’ Category

A toxin called fructose?

May 22, 2012

Here is a Q&A on the toxic effects of fructose which has all the information you ever wanted (and more)!

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Complexity of medicine and the capability of individuals

May 31, 2011

The inimitable Atul Gawande (via Swarup):

We are at a cusp point in medical generations. The doctors of former generations lament what medicine has become. If they could start over, the surveys tell us, they wouldn’t choose the profession today. They recall a simpler past without insurance-company hassles, government regulations, malpractice litigation, not to mention nurses and doctors bearing tattoos and talking of wanting “balance” in their lives. These are not the cause of their unease, however. They are symptoms of a deeper condition—which is the reality that medicine’s complexity has exceeded our individual capabilities as doctors.

The core structure of medicine—how health care is organized and practiced—emerged in an era when doctors could hold all the key information patients needed in their heads and manage everything required themselves. One needed only an ethic of hard work, a prescription pad, a secretary, and a hospital willing to serve as one’s workshop, loaning a bed and nurses for a patient’s convalescence, maybe an operating room with a few basic tools. We were craftsmen. We could set the fracture, spin the blood, plate the cultures, administer the antiserum. The nature of the knowledge lent itself to prizing autonomy, independence, and self-sufficiency among our highest values, and to designing medicine accordingly. But you can’t hold all the information in your head any longer, and you can’t master all the skills. No one person can work up a patient’s back pain, run the immunoassay, do the physical therapy, protocol the MRI, and direct the treatment of the unexpected cancer found growing in the spine. I don’t even know what it means to “protocol” the MRI.

Before Elias Zerhouni became director of the National Institutes of Health, he was a senior hospital leader at Johns Hopkins, and he calculated how many clinical staff were involved in the care of their typical hospital patient—how many doctors, nurses, and so on. In 1970, he found, it was 2.5 full-time equivalents. By the end of the nineteen-nineties, it was more than fifteen. The number must be even larger today. Everyone has just a piece of patient care. We’re all specialists now—even primary-care doctors. A structure that prioritizes the independence of all those specialists will have enormous difficulty achieving great care.

A must-read (obviously)!

The “silver-bullet” for infectious diseases

March 3, 2011

An interview with Kary Mullis at Seed:

Seed: Why do we need to rethink the way we treat infectious diseases?

Kary Mullis: Many pathogens are becoming resistant to our antibiotics. Consider penicillin, for example. We took it from a fungus that grew in the soil and killed bacteria for food. Because of this warfare, some bacteria had developed a resistance via DNA, to penicillin. Over time, they passed this resistance via DNA up to the pathogens that infect our bodies. So now many organisms—like Staphylococcus aureu, the cause of Staph infections—are, in large part, unaffected by penicillin. In this way a lot of bacteria have mutated around our antibiotics.

The standard pharmaceutical response is to go stomping through the jungle trying to find extracts of all the organisms and see if one of them will inhibit the growth of particular bacteria. And that of course will get more and more difficult as time goes on. It is clear that we need another solution.

Seed: What is your solution?

KM: A long time ago they used to speculate that there might be what they called a “silver bullet” for cancer. The idea was that if you could find some molecule that would bind to a cancerous cell but not to a non-cancerous cell and attach a radioactive atom—or some sort of poison—to that molecule, you could cure cancer. It turned out cancer didn’t work that way, but you can take a similar approach to fighting infectious diseases.

My work with PCR allowed for the invention by Craig Tuerk of nucleic aptamers, which are tiny binding molecules that can be designed to attach themselves to harmful bacteria. However, instead of attaching a poison to the other end of the aptamer—as the silver-bullet strategy would call for—I put something on there that is a target for our immune system, a chemical compound with which the immune system is already familiar and to which it is very strongly immune. What you end up with is a drug that will drag this thing to which you are highly immune over to some bacteria you don’t want in your body. And your immune system will attack and kill it.

Seed: Do you have any proof that it works?

KM: Yes, we cured anthrax in mice. If you infect a mouse with anthrax and then wait 24 hours and treat it with a penicillin-type drug, you get about a 40 percent survival rate. But using our drug you get a 100 percent survival rate. Of course, it is unlikely that you are going to get anthrax, but that is sort of a model system.

That is only the first half of the interview; go, read the full thing — because it is worth it!

Failures are stepping stones to…

June 14, 2010

Research. In this very interesting article in BioMed Central, Gregory Petsko writes about three phases of drug testing during the development of newer drugs. The first phase is for the assessment of toxicity of the drug to humans and is tested on healthy population. The second phase is for assessing how well the drug works with patients with the disease. The third phase tests are for assessing the effectiveness of the drug in comparison to what is available at the moment in the market.

Apparently, 19 out of 20 drug trails fail. And, most of them fail at phase two. And, the interesting point that Petsko makes is:

My main point is that the Phase II failures represent an enormous, untapped resource for the biomedical sciences – a resource that could go a long way towards solving the problem of low productivity, in terms of cures, that plagues both industry and academic medicine.

You see, the Phase II failures have all passed Phase I, so they have been shown to be safe in humans. They failed for efficacy. They failed because they did not effectively treat the disease they were intended to treat, even though they showed biological activity in assays and model systems. There are hundreds of them – perhaps more than a thousand. I don’t know the number because drug companies bury those failures. They don’t want to release a lot of information about the molecules in question because, among other things, they fear that will give their competitors too much of an insight into what they are working on. But here’s the question I would like you – and them – to ponder. What if those drugs were not tried on the right disease?

We now know that many quite different diseases share common pathways and processes in the cell. Cancer is a disease of abnormal cell survival; in Alzheimer’s disease the survival pathways have failed. Alzheimer’s patients have significantly lower risk of many cancers. What if the cure for Alzheimer’s disease is sitting on some drug company’s shelf, as a potential cancer drug that failed in Phase II? (A biotech company called Link Medicines is currently testing one such failure to find out.) Gaucher disease and Parkinson’s disease both involve lysosomal damage and display aggregates of a protein called alpha-synuclein; Gaucher carriers are at elevated risk for Parkinson’s. What if a drug intended to cure Gaucher disease, one that failed in Phase II, is actually a treatment for Parkinson’s? (Another biotech company, Amicus Therapeutics, is beginning to investigate that possibility.) Recent studies show that people diagnosed with psoriasis are at greater risk of developing heart disease; in fact, in patients with severe psoriasis who are younger than 50 years old, the risk is comparable to that seen in diabetes. How many Phase II-failed psoriasis drugs have ever been tested in heart disease clinical trials?

A very interesting piece!

PS: While you are at it, these two pieces on mammalian pheremones are interesting too:

On the scent of sexual attraction

Darcin: a male pheromone that stimulates female memory and sexual attraction to an individual male’s odour

What have we found out about the influenza A (H1N1) 2009 pandemic virus?

September 19, 2009

S J Turner et al, explain here! A good piece.

In search of Sanjeevani plant

September 10, 2009

In the latest column of Speaking of science, D Balasubramanian talks about this paper from the latest issue of Current science (pdf) and this commentary on it (pdf) from the same journal. Here is the abstract of the paper:

This article reports our attempt to explore the possible plants that could represent Sanjeevani – the mythical herb from the epic Ramayana. Our search was based on a set of criteria developed from the consistent details available from the epic on the names of the herb in different languages, its habitat, medicinal values and the ability to ‘resurrect’ life. Accordingly, from an initial list of potential candidate species, we have filtered two species on which initial studies can be focused. However, our search is not complete and hence not final, as there could be other approaches and accordingly, other suggestions as well for Sanjeevani.

Balasubramanian’s piece is also a nice summary of the work. Take a look!