Friday, November 16, 2012

A Call for FDA Regulation of Compounding Pharmacies

As I predicted on this blog on Oct. 9, a recent outbreak of fungal meningitis has led to a renewed call for FDA regulatory authority over the burgeoning drug compounding industry. As you may recall, the outbreak was traced to bad batches of a steroid that had been packaged by a drug compounding company in Massachusetts. So far 461 people have been infected and 32 persons have died, according to the CDC.

Drug compounding used to be done by neighborhood pharmacies on a limited basis, primarily for local doctors and patients. Traditionally, pharmacies are regulated by the individual states. But with the rise of the Internet and of large health care systems and hospital chains, compounding pharmacies have become highly specialized, high-volume facilities that sell their products nationwide. And yet like all pharmacies, compounding facilities are still regulated primarily by the pharmacy boards of individual states.

This week the commissioner of the FDA appeared before a congressional committee to ask for increased authority to monitor and regulate compounding pharmacies. According to the commissioner, compounding pharmacies are not even required to give the FDA access to their books, for example. Surprisingly (or perhaps not so surprisingly!) the congressional committee seems to be split along party lines, with republicans arguing that the FDA already has enough authority to regulate compounding pharmacies and democrats arguing that the FDA should be given more regulatory authority. We’ll be watching this one.

Thursday, November 15, 2012

A Home Test for HIV

The first in-home HIV test kit became available last month in retail stores nationwide. The test kit, called OraQuick, was approved by the FDA in July, but it took until October to ramp up production and launch a nationwide sales effort.

The kit is designed to test a sample of oral fluid for antibodies to HIV in under 45 minutes. The kit has a reported false positive rate (identifying a person as HIV-infected when in fact he/she is not) of only 0.02%, or 1 in 5,000 persons. However, it has a false negative rate (failure to identify an HIV-infected person as infected) of 8%, meaning that HIV infection will be missed in 1 in 12 infected persons. The reason for the higher false negative rate is because the test detects the human antibodies that develop in response to HIV infection, not the HIV virus itself, and it takes several months after initial infection for these antibodies to develop.

A similar test has been available in doctors’ offices for some time. Nevertheless, health officials are hailing the home test as an important step forward in the fight against HIV-AIDS. The hope is that the availability of an inexpensive home test will encourage more people to test themselves for HIV infection, and then to seek treatment if they test positive.

Tuesday, November 13, 2012

Curing Mitochondrial-Based Genetic Diseases

As you may know, 37 of our roughly 22,000 genes are located within mitochondria, rather than in the nucleus. Consequently these 37 genes are inherited entirely from the mother, since the female provides the egg (with its haploid number of chromosomes) and all of the egg’s organelles including the mitochondria. The male provides a haploid number of nuclear chromosomes.

A few inherited diseases are due to defects in those 37 mitochondrial genes. In fact the chance is about 1 in 4,000 that a child will develop a mitochondrial-based disease. Researchers think that these diseases could be among the first heritable diseases that could be permanently cured, according to a news report in Nature. How? The potential mother (with the mitochondrial-based genetic disease) and a healthy female donor would each provide an egg. The nucleus of the potential mother’s egg would be removed and inserted into the healthy mother’s enucleated egg. The egg would be fertilized by the potential father’s sperm, allowed to develop into a zygote (an early stage of development), and then inserted into the potential mother for development.

The child would have genes from two women, of course, but not very many from the donor woman - only 37 out of 22,000. And the child and all of its future descendants would be forever free of the disease.

So far, this has not yet been attempted beyond the zygote development stage. For one, genetically engineering a child is currently illegal. For another, the researchers who carried out the experiment to the zygote stage found a disturbing number of abnormalities in the zygotes they created. The researchers believe, however, that with further experimentation these problems could be overcome. The fact that we’re so close to curing a whole class of heritable diseases is likely to stimulate debate over whether such experiments should ever be conducted.

Sunday, November 4, 2012

Austalopithecus afarensis Definitely Climbed Trees

Analysis of the partial skeleton of “Lucy”, the best-known skeleton of Australopithecus afarensis discovered in 1974, revealed that the species was capable of standing and walking upright.  Many scientists presumed, based on the probable shape of her shoulder bones (some bones were missing) that she also still climbed trees, like her ancestors.  Others disagreed, arguing that the shape of her shoulder was just a vestigial retention from her ancestry, no longer of any real functional value.

To resolve this issue, researchers compared the anatomy of the scapula bone of a partial skeleton of a recently-discovered juvenile A. afarensis to the growth patterns of scapula bones of humans and modern apes.  They concluded that A. afarensis, like modern apes, used its upper limbs to climb and move through trees, at least part of the time.  Perhaps they slept in trees as a protective strategy, or climbed trees to harvest food.

The unique shoulder anatomy that permits overhead use of the upper limbs to climb and swing from trees disappeared in Homo erectus, a later transitional species in the human lineage.

Friday, November 2, 2012

Pregnancy Complications Among Women Born Pre-term

Women who were born pre-term are more likely to have pregnancy-related complications during their own pregnancies, according to Canadian researchers.

The authors compared pregnancy complications in over 7,000 women who were born pre-term, to nearly 17,000 women born at full term.  Women who were born before 36 weeks of gestation were 14% more likely to suffer gestational diabetes, gestational hypertension, or preeclampsia during their own pregnancies than women who were born full-term.   Women born before 32 weeks almost twice as likely to suffer these complications.

Fortunately, none of these pregnancy-related complications is terribly common.  In addition, all are tested for during normal prenatal care, and all can generally be managed when detected.  Women who were born pre-term should not be overly concerned, though they may wish to alert their pre-natal caregiver to ensure that follow-up is adequate.