Monday, September 25, 2006
Tuesday, September 19, 2006
OK, you keep hearing the scary headline about how "viruses" are being used to treat foods in order to kill bacteria that can cause food-borne illness. I wish reporters would stop using the word "virus". Although technically correct, it's causing unnecessary concern.
Let's back up a bit. Listeria Monocytogenes can cause serious bacterial illness in humans, characterized by nausea, vomiting and diarrhea. Each year, there are about 2500 cases of "Listeriosis" in the US, resulting in about 500 deaths. A new approach is being taken as a means to reduce the incidence of Listeriosis. It involves a "bacteriophage", an organism that infects and kills bacteria. Technically, bacteriophages fall within the general category of "viruses", but are incapable of infecting humans.
Recently, a bacteriophage has been designed to infect Listeria through thread-like structures called "flagella" (see photo above). Humans have never had and never will have flagella that could be mistaken for Listeria's appendages. The bacteriophage is made specifically to target Listeria, so as not to harm the "good" bacteria that inhabit our digective tracts. I'm hoping that as the correct information comes to light, people will be less leery of this new approach to food safety.
Thursday, September 14, 2006
Scientists are exploring new stem cell treatments to promote cartilage repair in damaged knees. The cartilage-like meniscus, the knee's shock absorber, is commonly damaged through sports injuries and arthritic disease. Approximately 800,000 people per year in the US have surgery to remove all or part of the meniscus. Fifty-five of these patients are now enrolled in a two-year study at the University of Southern California to determine whether an injection of bone-marrow stem cells can stimulate repair of the meniscus.
Eligible patients, aged 18-60, were enrolled prior to knee surgery. One week after surgery, some patients received a single injection of Chondrogen (a commercial preparation of adult bone marrow stem cells), whereas others received a placebo injection that contained no stem cells. Knees with and without stem cell treatment were examined by MRI (Magnetic Resonance Imaging) to check for meniscus regrowth over time.
This is a double-blind study, meaning that neither the patients nor their doctors will know which injections contained Chondrogen or a placebo until later in the study. The double-blind strategy encourages unbiased interpretation of the results. Early results of the study, funded by Osiris Therapeutics, are expected out in October 2006.
Saturday, September 09, 2006
- "[It] is a judgment of God, sent to punish and humble our sins; and what shall we so evade it, and think to turn it away from us?...God has predetermin'd and fixed the period of every ones life...so that if this time be come inoculation will not save the person's life."
- "[It is] a judgment on the sins of the people...to avert it is but to provoke him more".
- "[It is] an encroachment on the prerogatives of Jehovah", who has the right "to wound and smite".
Do these religious statements sound familiar? I thought so. It turns out that they were spoken by theologians almost 300 years ago in opposition to smallpox innoculation.
An intriguing method of preventing smallpox was being studied to see if material taken from cowpox sores or even smallpox lesions could be used prevent the deadly smallpox disease. Then, just as now, religious zealots tried to impose their own morality on disease; it was a punishment from G-d. To interfere with this punishment, would cause further anguish and death. It took a smallpox epidemic in Montreal to cause a shift in attitude:
In 1885 a smallpox epidemic broke out in Montreal, Canada. Almost everyone was vaccinated except the Catholic population there. When the authorities tried to force vaccination on their Catholic citizens, they were met with opposition that threatened to become violent. Rather than explaining to their parishioners the benefits of vaccination, the catholic clergy tolerated and in some cases even encouraged the behavior of the laity. A priest of St. James Church said in a sermon that, "if we are afflicted with smallpox, it is because we had a carnival last year, feasting with the flesh, which has offended the Lord;...it is to punish our pride that God has sent us smallpox." One religious newspaper even went further, telling the Montreal Catholics to take up arms rather than submit themselves to vaccination. Instead the catholic ecclesiastical authorities in the city called on their people to make certain devotional exercises, to hold a procession with an appeal to the Blessed Virgin and to use the rosary as specified. Needless to say the Catholic population in Montreal suffered many needless deaths from smallpox until the proper measure was finally enforced.
We see this same kind of opposition pattern today in the case of a human papilloma virus vaccine, designed to prevent cervical cancer. Vaccine opponents fear that innoculation will lead to sexual promiscuity. We hear others define AIDS as a punishment for sin. I long for the day when disease is seen by all as a bane of biology rather than measure of morality.
Wednesday, September 06, 2006
The Union of Concerned Scientists has a cartoon contest. All 12 of the finalists will be featured in a 2007 calendar. Vote for your favorite cartoon here: