Thursday, December 7, 2017

First U.S. Baby Born After a Uterine Transplant

It was bound to happen sooner or later. A U.S. woman who was born without a uterus has just given birth to healthy baby after doctors at Baylor University transplanted a uterus into her last year, according to an ABC news report.

Transplant doctors see it as a significant advance, and indeed it may be. Once perfected, the technique could offer hope to women who for whatever reason do not have a functioning uterus and so cannot experience pregnancy and childbirth. However, it is important to note that the technique is still in the research stage. Several of the very few uterine transplants performed so far have had to be removed because they failed.

I've written about some of the ethical and financial issues related to uterine transplants before (see this blog, Nov. 23, 2015 and Feb. 29, 2016). What do you think?

Sunday, December 3, 2017

A More Effective Shingles Vaccine

Shingles is a condition characterized by an itchy, painful rash that can last for weeks. It's caused by the same virus that causes chickenpox in children. In adults who had chickenpox as children, the virus can re-emerge later in life, causing shingles. Nearly a third of all untreated adults over 50 are likely to develop shingles at some time in their life.

There has been a vaccine against shingles, called Zostavax, since 2006. However, Zostavax has proven to be only 51% effective in preventing shingles. Consequently, many people who were vaccinated with Zostavax still came down with shingles.

Now there's a new, improved vaccine against shingles, according to a press release from GlaxoSmithKline. Last month the Advisory Committee on Immunization Practices recommended the new vaccine, called Shingrix, even for adults who have already been vaccinated with Zostavax.

Shingrix is reported to be 97% effective; nearly twice as effective as Zostavax.  Shingrix may be better in another way, too. Whereas the older vaccine consisted of live but attenuated (weakened) viruses, Shingrix consists of just a subunit of the virus, making it much less likely that the body will have a negative reaction to it.

Tuesday, November 14, 2017

The American Heart Association Redefines High Blood Pressure

The popular press (an NBC News report is an example) was full of the news yesterday that the American Heart Association (AHA) has come out with new recommendations for the treatment of high blood pressure (hypertension). According to the AHA, hypertension should now be defined as blood pressure above 130/80 mmHg. I'm sure the AHA has its reasons, but I'd be more comfortable with their recommendation if it wasn't the AHA's members (heart doctors) who stand to gain the most from the recommendations. The new recommendations summarily define nearly half the adult population as potential patients!

The new AHA recommendations are different from the recommendations of the Eighth Joint National Committee (JNC 8), an independent, unbiased group chosen from over 400 experts to examine the evidence and provide guidance to clinicians concerning the treatment of hypertension. The JNC 8 recommendations came only after an exhaustive review of the literature and were submitted to peer review by additional experts not on the panel before they were published.  JNC 8 recommends treatment of hypertension to the goal of lowering pressure to below 140/90, not 130/80.

The AHA argues that blood pressure above 130/80 doubles your relative risk of heart disease, compared to pressures below that level. That may be so, but there's a big difference between relative risk and absolute risk. A doubling of relative risk can be as little as an increase in absolute risk from one in a million to two in a million. Think about that before you commit yourself to a lifetime of antihypertensive medication.

Sunday, November 12, 2017

Aaron Hernandez Suffered From CTE

Remember Aaron Hernandez, the standout football player at the University of Florida who played for the New England Patriots from 2010 to 2012? He was convicted of murder in 2015 and later hanged himself in his prison cell.

Now neuropathologists at Boston University have released his autopsy report. According to CNN News, the report indicates that Hernandez had the worst case of chronic traumatic encephalopathy (CTE) ever seen by BU pathologists in someone of his age. He was only 27 years old at the time of his death. Whether his behavior in the last few years of his life was related to the CTE is unknown.

There has been a lot of discussion lately about the effects of repeated head trauma, and how it might lead to CTE. The association between head trauma and CTE is so strong now that the NFL has set up a fund to provide up to five million dollars per retired player for medical expenses related to CTE. And there have been changes to the rules of football to try to reduce incidences of head trauma in current players. Nevertheless, CTE is likely to remain a problem for football for some time to come; Boston University pathologists have found evidence of CTE in nearly all of the brains of former NFL players that have been examined so far.

According to a USAToday news report, retired sportscaster Bob Costas predicts a decline in interest in the sport of football unless something is done to make it safe. It will be interesting to see whether he is right or wrong.

Saturday, November 11, 2017

Alcohol and Cancer Risk

The American Society of Clinical Oncology, the professional society comprised of cancer doctors, has issued a statement to the effect that alcohol consumption is a risk factor for cancer. The society says that no amount of alcohol is completely safe; even small amounts can contribute to esophageal cancer, as well as breast cancer in women.

A suspicion that alcohol can contribute to a variety of cancers is not new, but this is the first time that clinical oncologists have issued an official statement on the subject. In preparing for their statement, the group reviewed published studies on alcohol consumption and cancer and came to the conclusion that 5-6% of all new cancers and cancer deaths are due to alcohol consumption. That's not nearly the risk associated with smoking, for example, but it is significant. Higher levels of alcohol consumption are associated with higher cancer risk.

No one is saying categorically, "Don't drink". It's just something that one should be aware of if or when one chooses to drink.

Wednesday, November 8, 2017

A New Species of Great Ape

Scientists have confirmed that a group of great apes discovered nearly 20 years ago is indeed a different species from all the other known great apes, according to a BBC news report. It's the first documented new ape species in more than 100 years.

First discovered in 1997 in remote forests of Sumatra, the Tapanuli orangutan (genus/species Pongo tapanuliensis) is distinctly different from Bornean and Sumatran orangutan species. DNA evidence indicates that it split from a common ancestor of the Sumatran orangutan about 700,000 years ago. In addition, its skull structure is different from either of the other two orangutan species, and it vocalizes differently. A research paper documenting the new species is published in the journal Current Biology.

Now for the bad news. There are only an estimated 800 individuals of this new species, meaning that it is in danger of extinction.

Monday, November 6, 2017

Coronary Artery Stents Don't Reduce Angina Pain

For decades, cardiologists have been inserting stents into their patients' partially blocked coronary arteries in order to improve blood flow to the heart. Stents are particularly effective in patients who have already suffered a heart attack. But stents are also used to improve coronary blood flow in patients who have not had a heart attack but are suffering from angina, the chest pain that some patients feel when coronary blood flow is compromised. It makes sense, right? It's always a good idea to improve coronary blood flow.....isn't it?

Cardiologists generally think so. And it's a big business for them; more than 500,000 stents are performed every year at $14,000 - $40,000 a pop, according to some estimates. But now a new study by British researchers questions whether the patients are actually improved by the procedure.

The study is unusual in that it is a true double-blind study with a control group. Two hundred patients suffering from angina due to a severely blocked coronary artery were recruited. Half of them got a stent, and the other half underwent the same surgical procedure, but the stent was just inserted and then removed. It's hard to get approval for this kind of study in humans, because if you can show that a treatment works, you can't ethically withhold it from some patients just to prove a point! In fact, the stents did improve coronary blood flow in the patients that received them. But more to the point, there were no differences between the two groups in the ability to do exercise six weeks later or in their self-reported pain.

Cardiologists are busy assessing what it all means, according to an article in The New York Times. In all likelihood the clinical guidelines for the use of stents in patients with angina will have to be revised, or at least re-examined. And additional studies will probably be needed to try to determine whether there might be some other benefit of the stents, such as a reduced risk of heart attacks further down the road.