A novel soft-photon amplitude is proposed to replace the conventional Low soft-photon amplitude for nucleon-nucleon bremsstrahlung. Its derivation is guided by the standard meson-exchange model of ...the nucleon-nucleon interaction. The new amplitude provides a superior description of
ppγ cross section data for kinematic conditions where the Low amplitude disagrees with potential-model calculations.
X-linked juvenile retinoschisis(RS) is a recessively inherited vitreo-retinal degeneration characterized by macular pathology and intraretinal splitting of the retina. The RS gene has been localized ...to Xp22.2 to an approximately 1 Mb interval between DXS418 and DXS999/DXS7161. Mapping and expression analysis of expressed sequence tags have identified a novel transcript, designated XLRS1, within the centromeric RS locus that is exclusively expressed in retina. The predicted XLRS1 protein contains a highly conserved motif implicated in cell-cell interaction and thus may be active in cell adhesion processes during retinal development. Mutational analyses of XLRS1 in affected individuals from nine unrelated RS families revealed one nonsense, one frameshift, one splice acceptor and six missense mutations segregating with the disease phenotype in the respective families. These data provide strong evidence that the XLRS1 gene, when mutated, causes RS.
Previously recognized pelagic nemerteans, with the single exception of Korotkevitschia pelagicus, have been polystiliferous hoplonemerteans. The briefly described Amphiporus scoresbyi, later ...transferred to Nipponnemertes, was unrecognized as a pelagic form. Re-examination of the type material and re-evaluation of the collection data reveal that this form represents a second pelagic genus of the Cratenemertidae, and it is here redescribed as Achoronemertes scoresbyi gen. et comb. n. The importance of these findings rests largely in the fact that despite the clearcut family, geographic, and habitat affinities between Korotkevitschia and Achoronemertes gen. n., their numerous differences in morphology are as striking as some of the differences among the polystiliferous pelagic genera and may provide a new perspective for re-evaluation of pelagic forms generally. An English translation of Korotkevich's original description of Korotkevitschia pelagicus is included as an appendix.
Recent reports have suggested that mast cells are capable of producing and releasing a number of pro-inflammatory cytokines. However, these studies have mainly been carried out using murine tissue ...culture derived mast cells and it is known that these cells differ markedly in their functional properties from isolated human mast cells. It was therefore essential to study the release of cytokines from the latter cell type. On immunological stimulation with anti-immunoglobulin E (anti-IgE) or stem cell factor (SCF), purified human lung mast cells released, within 2–10 min, small amounts of tumour necrosis factor-α (10.5±2.9 pg/10
6 mast cells and 17.9±7.9 pg/10
6 mast cells, respectively) and interleukin-4 (5.3±2.5 pg/10
6 mast cells and 8.0±3.2 pg/10
6 mast cells, respectively). After longer periods of activation (30 min–4 h), the amounts of cytokines released from stimulated cells decreased to levels which were below those of the unstimulated cells. This possible degradation of cytokines by mast cells could not be prevented by the addition of protease inhibitors.
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