Medicine on Michael’s Domain

This year's Nobel prizes

Mon, 12 Oct 2015 00:00:00 +0000

Three of this year’s nobel prizes were given for topics we work on: The prize in Medicine was shared by Youyou Tu and William Campbell/Satoshi Ōmura. Campbell and Ōmura received their share for the development of an anti-parasite drug that is effective against roundworms (nematodes), which are the cause of river blindness, lymphatic filariasis and a few other diseases. Nematodes, that cause lymphatic filariasis (like Brugia malayi) are living in the lymphatic system. Many nematodes do express a VEGF-C-like molecule, but the function of this parasite-VEGF-C for the nematode’s life cycle has never been looked at.The prize in Chemistry was shared by Tomas Lindahl, Paul Modrich and Aziz Sancar for their mechanistic studies of DNA repair. We are right now experimenting with such mechanisms, especially the cytidine deamination, which we exploit in order to generate mutations on demand. When cytidine is converted into uracil (which can happen spontaneously or mediated by an enzyme), the enzyme Uracil-DNA glycosylase (UNG) removes the uracil base. Then another enzyme (apurinic/apyrimidinic endonuclease) cleaves the backbone 5’ to the abasic site and DNA polymerase beta excises the abasic sugar phosphate residue and inserts a cytosine thus repairing the damage.The third prize is the one in Economic Sciences, which went to Angus Deaton. “He pioneered the analysis of individual dynamic consumption behavior under idiosyncratic uncertainty and liquidity constraints.” (from the Advanced Information PDF by the Royal Academy. I freely translate: He researched how peoples ‘spending behaviour changes in the face of irregular and insufficient income. That describes quite well our lab’s financial situation and we indeed work on that issue, because science without money doesn’t work.

How much toothpaste is safe to swallow for a 3 year old?

Mon, 22 Dec 2008 00:00:00 +0000

My son doesn’t like to brush teeth and he is probably no exception. In order to protect his teeth, we started to use a fluoride-containing tooth paste when he was about 2 years old. However, we were always careful and didn’t let him swallow the toothpaste in order to avoid overdosing. There are likely still quite a few cases of acute fluoride poisoning in small children every year (Shulman & Wells, 1997) and not surprisingly they are mostly caused by ingestion of large amounts of fluoride containing toothpaste. Just now I made the calculation and my son was probably never in danger of overdosing due to the fact that the water we get here in Helsinki from our local utility supplier Helsingin Vesi is very low in fluoride (0.1 mg/l or 0.1 ppm). He brushes his teeth twice a day and uses each time a pea-sized amount of tooth paste (equaling about 0.15 g). The toothpaste he uses (OralB Stages) contains 0.11% sodium fluoride (equaling 0.05% fluoride). This means that if he swallowed all of his toothpaste he would ingest 0.15 mg of fluoride per day. This is 30% of the daily amount of fluoride supplementation recommended by the American Dental Association for children between 3 and 6 years of age and still less than the daily amount recommended for children of ages between 6 months and 3 years (0.25 mg). I have not encouraged him to swallow the tooth paste although there seems nothing to argue against doing so apart from my parental inconsistency. Daddy probably doesn’t know as he changes his mind all the time… But I guess since he is chewing very avidly his xylitol chewing gum , he should be fine even without much fluoride.

The E-numbers of ADHD-like behaviour inducing food colors and additives

Fri, 28 Nov 2008 00:00:00 +0000

There has been a publication about artificial colors and other food additives influencing children’s behaviour ( McCann, 2007 ), making it more ADHD-like. This is perhaps due to the chemicals’ influence on brain chemistry. This claim is not new, just the methodology (double-blind, randomized). I just checked out this paper and figured out the corresponding E numbers. Unfortunately the research used “cocktails” of these additives and therefore some of these might be harmless. But nevertheless, here is the list: