Population Growth and the Ebola Epidemic

The tragic spread of Ebola virus in Africa has been discussed at length as a failure of public health systems resulting from inept governance and from poverty. However, a root cause of the epidemic lies in the rapid and unchecked population growth in Africa.  Unlike developing countries in other parts of the world, African nations currently do not seem to be undergoing the ‘demographic transition’ that associates rising GDPs with falling fertility (1). The rapid increase in population sets the stage for transmission of diseases such as Ebola in two ways. First, by migration of people from overcrowded agricultural land to forest areas where more contact with animal disease vectors is possible. Second, by the ever-increasing populations in congested urban slum area where disease transmission is facilitated. Effective control of infectious disease epidemics in Africa (and elsewhere) must including more aggressive family planning services.

(1)  Dyer, G. (2013) http://www.straight.com/news/394516/gwynne-dyer-world-population-growth-and-african-exception.

New Hope for Age-Related Eye Diseases

The announcement of a clinical trial of induced pluripotent stem cells (iPS cells) in Japan (1) has somewhat of a personal aspect for me.  I have recently been having some retinal problems consequent to a mishandled cataract operation.  This has made me very aware both of how important and how delicate our visual systems are. The Japanese trial will use iPS cells in patients suffering from age related macular degeneration, a common but difficult to treat eye disease. Since the retinal cells to be implanted will derive from the patient's own cells via the iPS approach, hopefully there will be no immune rejection.

As an older person I cheer the push toward stem cell therapies. It will probably come too late for my generation, but  hopefully a combination of stem cell and genetic technologies will eventually be able to attenuate many debilities that accrue with age.

(1)  http://www.nature.com/news/japan-stem-cell-trial-stirs-envy-1.15935

GDF11- the Elixir of Youth??

A feature article in SCIENCE this week (1) summarized some very impressive work from Amy Wagers (Harvard) and other researchers on blood factors that seem able to partially reverse age-related tissue degeneration. Several groups have used a technique termed parabiosis to establish a shared circulation between old and young mice.  This resulted in improved function in muscles, heart, and nerves of the older mice. One possibility is that blood factors from young mice restore the ability of stem cells in older animals to repopulate damaged tissues. In an exciting new development Wagers and colleagues have identified a protein termed GDF11 as the rejuvenating blood factor. GDF11 is a member of the TGB-beta family of growth factors that regulate many aspects of tissue differentiation and growth.

These results would seem to open up new opportunities for clinical approaches that address ageing per se rather than individual diseases associated with ageing. Some strong arguments have been made that this approach would make a much greater contribution to human health and longevity than disease specific therapies (2).

(1)  http://www.sciencemag.org/content/345/6202/1234.full

(2)  Goldman, D. P., et al. (2013), 'Substantial health and economic returns from delayed aging may warrant a new focus for medical research', Health Aff (Millwood), 32 (10), 1698-705.

Re-branding the PhD

This week’s NATURE has a rather bizarre editorial regarding careers for PhDs (1). The editors acknowledge that currently many individuals with PhDs do not find academic positions, or even positions actually doing research, but rather wind up in a variety jobs that really do not require intensive research training, ranging from high school teaching to investment banking. However, rather than viewing this as a problem in PhD supply-demand economics, the editors chose to put a cheerful spin on the situation and brand all of the ‘alternative careers’ as a good thing.

To my mind the American Society for Cell Biology (2) has a more realistic perspective when it states that in the current context, where less than 10% of enrolled biomedical PhD students will become tenure track faculty, “A faculty job is an ‘alternative’ career”. To be sure NATURE has previously discussed the PhD glut from a more balanced perspective (3). However, the current attempt to view a bad situation through rose-colored glasses is not helpful.

As discussed several times on this blog (4,5) the PhD oversupply is the result of self-interested actions on the part of faculty and university administrators. Cheap labor is needed to keep the grants and publications coming.

(1)  http://www.nature.com/news/there-is-life-after-academia-1.15808

(2) go.nature.com/vh1ewm

(3)  nature.com/phdfuture

(4) http://scienceforthefuture.blogspot.com/2010/02/why-are-there-still-too-many-graduate_10.html

(5) http://scienceforthefuture.blogspot.com/2013/03/more-money-fewer-phds.html