Coding haplotype analysis supports HCR as the putative susceptibility gene for psoriasis at the MHC PSORS1 locus

PSORS1, near HLA-C, is the major genetic determinant of psoriasis. We present genetic and structural evidence suggesting a major role for the HCR gene at the PSORS1 locus. Genotyping of 419 families from six populations revealed that coding single-nucleotide polymorphisms of HCR formed a conserved allele HCR*WWCC that associated highly significantly with psoriasis and with the HLA-Cw6 allele in all populations. Because of strong linkage disequilibrium between HLA-Cw6 and HCR*WWCC, the two genes could not be genetically distinguished by this sample size. However, the variant HCR allele was predicted to differ in secondary structure from the wild-type protein. HCR protein expression in lesional psoriatic skin differed considerably from that observed in normal skin. These results provide strong evidence for the HCR*WWCC allele as a major genetic determinant for psoriasis, probably by a mechanism impacting on keratinocyte proliferation.     

Spectral discrimination of Cerenkov radiation in scintillating dosimeters

Radiation therapy accelerators require highly accurate dose deposition and the output must be monitored frequently and regularly. Ionization chambers are the primary tool for this control, but their size, their high voltage needed, and the correction needed for electrons make them unsuitable for use during patient treatment. We have developed a small (1-mm-diam and 1-mm-long active part), flexible, and water-equivalent dosimeter. It is suitable for photon and electron beams without corrections, and performs on line dose measurements. This detector is based on only one scintillating fiber and a CCD camera. A new signal processing is used to remove the effect of Cerenkov radiation background, which only requires a preliminary calibration. Central-axis depth-dose distribution comparisons have been achieved with standard ionization chambers, over a range from 8 to 25 MV photons and from 6 to 21 MeV electrons in order to validate this calibration. Results show a very good agreement, with less than 1% difference between the two detectors.     

Multilocus sequence typing for studying genetic relationships among Yersinia species

The intra- and interspecies genetic relationships of 58 strains representing all currently known species of the genus Yersinia were examined by multilocus sequence typing (MLST), using sequence data from 16S RNA, glnA, gyrB, recA, and Y-HSP60 loci. Yersinia aldovae, Y. bercovieri, Y. intermedia, Y. pestis, Y. pseudotuberculosis, Y. rohdei, and Y. ruckeri were genetically more homogeneous than were Y. enterocolitica, Y. frederiksenii, Y. kristensenii, and Y. mollaretii. The MLST data concerning the genetic relatedness within and among various species of Yersinia support the idea that Y. pestis and Y. pseudotuberculosis are two lineages within the same species rather than two distinct species. Y. ruckeri is the genetically most distant species within the genus. There was evidence of O-antigen switching and genetic recombination within and among various species of Yersinia. The genetic relatedness data obtained by MLST of the four housekeeping genes and 16S RNA agreed in most, but not all, instances. MLST was better suited for determining genetic relatedness among yersiniae than was 16S RNA analysis. Some strains of Y. frederiksenii and Y. kristensenii are genetically less related to other strains within those species, compared to strains of all other species within the genus. The taxonomic standing of these strains should be further examined because they may represent currently unrecognized Yersinia species.     

The cytoplasmic domain of tissue factor contributes to leukocyte recruitment and death in endotoxemia

Tissue factor (TF) is an integral membrane protein that binds factor VIIa and initiates coagulation. The extracellular domain of TF is responsible for its hemostatic function and by implication in the dysregulation of coagulation, which contributes to death in endotoxemia. The role of the cytoplasmic domain of tissue factor in endotoxemia was studied in mice, which lack the cytoplasmic domain of TF (TF(deltaCT/deltaCT)). These mice develop normally and have normal coagulant function. Following i.p injection with 0.5 mg of lipopolysaccharide (LPS), TF(deltaCT/deltaCT) mice showed significantly greater survival at 24 hours compared to the wt mice (TF(+/+)). The serum levels of TNF-alpha and IL-1beta were significantly lower at 1 hour after LPS injection and IL-6 levels were significantly lower at 24 hours in TF(deltaCT/deltaCT) mice compared to TF(+/+)mice. Neutrophil recruitment into the lung was also significantly reduced in TF(deltaCT/deltaCT) mice. Nuclear extracts from tissues of endotoxemic TF(deltaCT/deltaCT) mice also showed reduced NFkappaB activation. LPS induced leukocyte rolling, adhesion, and transmigration in post-capillary venules assessed by intravital microscopy was also significantly reduced in TF(deltaCT/deltaCT) mice. These results indicate that deletion of the cytoplasmic domain of TF impairs the recruitment and activation of leukocytes and increases survival following endotoxin challenge.     

Primary Amine‐Initiated Polymerizations of Alanine‐NCA and Sarcosine‐NCA

Summary: Sarcosine‐N‐carboxyanhydride (Sar‐NCA), L ‐alanine‐NCA and D,L ‐alanine‐NCA were polymerized with benzylamine as initiator in three different solvents: dichloromethane (CH₂Cl₂), 1,4‐dioxane and dimethylformamide (DMF). The isolated polyaminoacids were characterized by ¹H NMR spectroscopy and MALDI‐TOF mass spectrometry. High conversions and degrees of polymerization s close to the monomer‐initiator (M/I) ratios were found for all polypeptides. For polysarcosine which was soluble under the given reaction conditions a narrow monomodal frequency distribution was found. In contrast, a broad frequency distribution was observed, when L ‐alanine NCA was polymerized in dioxane and DMF. These results were attributed to a partial precipitation of oligopeptides in the β‐sheet structure, which reduces the reactivity of endgroups for steric reasons. The polymerizations of D,L ‐alanine‐NCA showed features in between the extremes of Sar‐NCA and L ‐Ala‐NCA.

Schematic illustration of the secondary structures formed in a primary amine initiated polymerization of L ‐Ala‐NCA.     

The obstetric outcome of singleton pregnancies following in-vitro fertilization/gamete intra-Fallopian transfer

The present study compares 465 singleton live deliveries fromin-vitro fertilization/gamete intra-Fallopian transfer (IVF/GIFT)pregnancies with a large control population to evaluate theincidence of pre-term delivery and small for gestational age(SGA) or very small for gestation age (VSGA) babies resultingfrom IVF/GIFT pregnancies. Overall the incidence of SGA or VSGAfrom an IVF/GIFT pregnancy is higher than from the normal obstetricpopulation (SGA odds ratio 1.76, 95% confidence interval (CI):1.38–2.25 and VSGA odds ratio 1.61, 95% CI: 1.05–2.46)particularly among primiparous women (SGA odds ratio 1.99, 95%CI: 1.25–3.16 and VSGA odds ratio 1.97, 95% CI: 1.49–2.62).After stratifying by the cause of infertility, only women withunexplained infertility had a significantly higher proportionof SGA/VSGA babies. There was a significantly higher incidenceof pre-term deliveries among the young primiparae (odds ratio5.02, 95% CI: 3.09–8.13). Thus the excess risk of deliveringa SGA/VSGA baby and pre-term delivery from an IVF/GIFT pregnancyseems to be largely confined to women with unexplained infertilityand young primiparae.     

PHI+], a novel Sup35-prion variant propagated with non-Gln/Asn oligopeptide repeats in the absence of the chaperone protein Hsp104

BACKGROUND: The [PSI+] element of the budding yeast is an aggregated form of the translation release factor Sup35 that is propagated and transmitted cytoplasmically in a manner analogous to that of mammalian prions. The N-terminal of Sup35, necessary for [PSI+], contains oligopeptide repeats and multiple Gln/Asn residues. RESULTS: We replaced the Gln/Asn-rich prion repeats of Sup35 with non-Gln/Asn repeats from heterologous yeast strains. These non-Gln/Asn repeat Sup35s propagated a novel [PSI+] variant, [PHI+], that appeared de novo 103 times more frequent than [PSI+]. [PHI+] was stably inherited in a non-Mendelian fashion, but not eliminated upon the inactivation of Hsp104, unlike known [PSI+] elements. In vitro, non-Gln/Asn repeat domains formed amyloid fibres that were shorter and grew more slowly than did Gln/Asn-rich prion domains, while [PHI+] aggregates were smaller than [PSI+] aggregates in vivo. CONCLUSIONS: These findings suggest the existence of an alternative, Hsp104-independent pathway to replicate non-Gln/Asn variant Sup35 prion seeds.     

Production of Specific Antisera to Human B Lymphocytes

Antisera have been prepared, in mice and rabbits, to membrane and sub-membrane fractions of human B lymphocyte derived lymphoid lines. Antisera to a protein subfraction were, after only minimal absorption, specific for human peripheral B lymphocytes, monocytes and B cell derived lymphoid lines. The antigen(s) recognised by these antisera were not the same as the previously described B-cell markers; immunoglobulin, Fc receptor, complement receptor and Ia antigens. The antigen(s) could not be removed from cells by lysostrip with anti- β₂ microglobulin.