As filaggrin – one of our best atopy genes – is vitamin D dependent, I tried to find out more about epidermal differentiation. The plot here summarizes an earlier review:
There seems to be a clear calcium gradient with the expression of differentiation specific marker in the single strata. So there is some good chance that filaggrin effects may be modified by external vitamin D supply.
For everybody who wants to follow up the most recent discussion about allergy promoting effects of vitamin D here is a short summary. The Harvard group basically wrote three articles that were immediately contradicted. The comment on the first article in JACI was by a NIH researcher Continue reading Vitamania
The central limit theorem states that a sum of independent identically distributed random variables (lets say allele counts in genomewide association scans) of finite variance will be approximately normally distributed. Unfortunately the maximum of the distribution will not reflect the true value … or did I get it wrong?
I am currently playing with MACH and SNPMStat to impute marker based on public datasets. I do not have any opinion about the usefulness of this approach – largely due to the fact that ~10% of my allele coding is different to the public hapmap data. Continue reading How to impute marker genotypes
The appendix of Frey includes a list of errors based on evolutionary psychology (EP) – some acquired during development of our species, some acquired during individual ontogenesis. It is certainly the best what I have read since the famous study biases Continue reading Evolutionary psychology and science: The full error list
There is an interesting new dissertation (“Ulrich Frey. Der blinde Fleck. Kognitive Fehler in der Wissenschaft und ihre evolutionsbiologischen Grundlagen”) that contains a nice game
Continue reading How to do better research
So far, I haven’t seen so much work about epigenetic regulation of vitamin D. There was already a paper in 2005 that showed how treatment with the
methylation inhibitor 5-aza-2′-deoxycytidine together with the deacetylation inhibitor trichostatin A resulted in elevation of both CYP27B1 and CYP24 mRNA expression demonstrating that even in normal human prostate cells expression of Vitamin D hydroxylases may be under epigenetic control
Continue reading Is there any environmental conditioning of vitamin D metabolism?
A report in Biospektrum 07.07/13:762 about the production of endotoxin free ovalbumin by a German company now reveals that nearly all commercially available ovalbumin preparations are highly contaminated with endotoxin. Company A included 723, company B 1038, company C 257 and company D 342 EU/mg LPS. As all mice are usually also on a vitamin D supplement diet, recent mouse studies may have produced largely artifacts if both – agonist and antagonist – are included in an uncontrolled manner, yea, yea.
We probably all agree that a publication bias against negative studies will severely distorts our opinion. To repeat an earlier Nature letter
Why negatives should be viewed as positives … This filtering of results undoubtedly biases the information available to scientists (see, for example “Null and void” Nature 422, 554–555; 2003). And communication is at the heart of science.
Here is an email that I received from the editor Continue reading Bias against negative studies
Science reports that the NEJM is being sued by Pfizer
in various jurisdictions on product liability grounds. Plaintiffs are claiming that its products Celebrex and Bextra cause cardiovascular and other injuries. Pfizer asserts that in some cases plaintiffs are making use of published papers from the New England Journal of Medicine (NEJM). So it wants to dig though the confidential reviews of those papers in search of something to strengthen its defense.
Two giants fighting each other… Continue reading Yes, it is true and and quite right too
A comment on the online Nature website says it all
Phantastic. Moreover, the peer-review system is broken with top PI’s getting away with publishing high impact poorly reviewed rubbish. If more non-peer-reviewed research becomes more prominent it will hardly make a difference to quality and can overall only be a good thing.
commenting on the recent decision at Harvard to automatically publish all papers by its Faculty of Arts and Sciences on the university’s website (except there is a waiver). I am waiting for the first German university to follow; effectively since January 2008 we get all our ordered documents on paper again for copyright reasons.
Current RNA chip technology, although quite advanced, is usually limited to known transcripts. As rare transcripts (N=1 to 5) usually cannot be quantified, current chip technology is probably useless for building realistic virtual cells. Maybe there are there are other options? SAGE – serial analysis of gene expression – has been also around Continue reading SuperSAGE plus highly parallel sequencing
This is the book that I am currently reading – a monologue of the world famous journalist Tiziano Terzani – who describes at the end of his life his view of the “scientific” medical approach at MSKCC, the achievements but also shortcomings. “Un altro giro di giostra”.
A nice study in Hum Genet by Eiberg hit the public press (and the blogosphere 1|2). Although I agree with most commentators that this is a sound study with a bit antiquity dust in the methods, I am unsure if I should believe the main conclusion of a founder mutation Continue reading Blue eyes
I wonder about the title of a new nature medicine editorial
Breathing easier with breast milk
It is not so much the unwanted analogy to aspiration; the paper simply hasn´t to do anything with breathing. It is a poor narrative of a concomittant NM article repeating many of its prejudices. Although the authors would like to let you belief that they have discovered allergen transfer into breast milk, this is known Continue reading Parascience in nature medicine?