Collembola are Unlikely to Cause Human Dermatitis

There have been several unconfirmed case reports of dermatitis caused by Collembola (springtails). We recently investigated two nurses with dermatitis suspected to be caused by Drepanura Schött (Collembola: Entomobryidae). IgE antibodies to Collembola proteins were not detected in sera from the nurses and skin tests with the Collembola extract and crushed whole Collembola were negative in both the nurses and volunteers. This study suggests that the springtail Drepanura may not cause human dermatitis and that other organisms and organic matter that are also found in the moist environment inhabited by Collembola might instead be responsible

Collembola are Unlikely to Cause Human Dermatitis

There have been several unconfirmed case reports of dermatitis caused by Collembola (springtails). We recently investigated two nurses with dermatitis suspected to be caused by Drepanura Schött (Collembola: Entomobryidae). IgE antibodies to Collembola proteins were not detected in sera from the nurses and skin tests with the Collembola extract and crushed whole Collembola were negative in both the nurses and volunteers. This study suggests that the springtail Drepanura may not cause human dermatitis and that other organisms and organic matter that are also found in the moist environment inhabited by Collembola might instead be responsible

Positive Selection of Tyrosine Loss in Metazoan Evolution

John Nash showed that within a complex system, individuals are best off if they make the best decision that they can, taking into account the decisions of the other individuals. Here, we investigate whether similar principles influence the evolution of signaling networks in multicellular animals. Specifically, by analyzing a set of metazoan species we observed a striking negative correlation of genomically encoded tyrosine content with biological complexity (as measured by the number of cell types in each organism). We discuss how this observed tyrosine loss correlates with the expansion of tyrosine kinases in the evolution of the metazoan lineage and how it may relate to the optimization of signaling systems in multicellular animals. We propose that this phenomenon illustrates genome-wide adaptive evolution to accommodate beneficial genetic perturbation

Genotype analyses using SNP (using MALDI-TOF Mass spectrometry) and STR (microsatellite) markers in the determination of zygosity status of Chinese Twins

It has been argued that single nucleotide polymorphisms (SNPs) is a very useful tool complementary to microsatellite analyses in the near future due to its relative ease of automation and interpretation. However, because allele frequencies can vary greatly among populations, it is important to validate and identify the informative SNPs that are useful for sample identification in biomedical and epidemiological studies. We have genotyped 768 individuals (384 pairs of twins) with a panel of SNPs based mostly on the SNPs chosen by an earlier work conducted by Lee et al., 2005 for Koreans, which we hypothesized to be useful for our Chinese subjects. The MALDI-TOF mass spectrometry based iPLEX Gold assay on the MassARRAY® Platform method using Sequenom was used for determination of the zygosity status of the twins. The ABI microsatellite kit (AmpFISTR identifiler PCR amplifcation kit) for measuring 16 loci was used to confirm the zygosity status. We found that some of the SNPs (2/22) used in Lee’s paper were not suitable for our Hong Kong Chinese samples. The zygosity status as determined by the mass spectrometry method can be validated with microsatellite method using 76 samples. In summary, we have studied a panel of 25 SNPs on their effectiveness in distinguishing identical and non-identical twins (768 individuals) for the Hong Kong Chinese population using the iPLEX method of Sequenom. It is important to optimize SNP panels for genotyping depending on the population and the platform used for the studies