Biomarker profiles in serum and saliva of experimental Sj?gren's syndrome: associations with specific autoimmune manifestations

Introduction  

Sj?gren's syndrome (SS) is a systemic autoimmune disease that mainly targets the exocrine glands. The aim of this study was to investigate the involvement of 87 proteins measured in serum and 75 proteins analyzed in saliva in spontaneous experimental SS. In addition, we intended to compute a model of the immunological situation representing the overt disease stage of SS.     

Identification of aromatic dihydroxy acids in biological fluids

3,5-Dihydroxyphenylpropionic acid, 3,5-dihydroxycinnamic acid and 2,3-dihydroxycinnamic acid were detected for the first time to be components of human urine. In the course of this investigation all constitutional isomers of dihydroxy-benzoic, -phenylpropionic, -phenylacetic and -cinnamic acid were synthesized. Mass spectra and retention indices of methyl and trimethylsilyl (TMS) derivatives were determined. In contrast to many other substituted aromatic compounds the mass spectra of methyl and TMS derivatives of dihydroxy aromatic acids often allow a firm distinction to be made between constitutional isomers: TMS derivatives of aromatic acids containing two hydroxy groups located in the ortho position to each other can be recognized by ions resulting from a primary cleavage reaction mainly in the side chain or ester group, followed by loss of tetramethylsilane. In methyl derivatives of 1,2,3-trisubstituted isomers, methoxy groups are lost much more easily from the ions corresponding to the benzylic cleavage than in other isomers. Methyl derivatives of dihydroxycinnamic acids containing at least one methoxy group in the ortho position to the side chain are characterized by a fragmentation reaction, corresponding to the loss of dimethyl ether. TMS and methyl derivatives of 3,5-dihydroxy aromatic acids show unique structure-specific fragmentation reactions.     

Untersuchungen über die lichtabhängige Carotinoidsynthese

Summary In conidia-free submerged cultures of Neurospora crassa the various steps of light-dependend carotenoid synthesis were studied. The mycelium produces small amounts of pigments even in the dark. The data obtained are in part in good agreement with earlier results of Zalokar and show that the light-induced pigment production starts after a lag-period of 40 min and is finished after 6–8 hours; the photoreaction is saturated by relatively small dosages. In contrast to Zalokar's results we found that for photoinduction the reciprocity law holds true. The photoreaction is saturated by a certain amount of light independently of the light-intensity. Actidion (Cycloheximide) inhibits carotenoid synthesis completely when added before or up to 10 min after the onset of illumination, whereas addition 60 min after illumination already has no effect. Comparison with the results obtained with Fusarium shows that the reaction mechanism is very similar in both organisms, though the various steps seem to proceed faster in Neurospora.

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Herrn Prof. Dr. L. Brauner in Verehrung und Dankbarkeit zum 70. Geburtstag gewidmet.     

The effects of host distributional patterns on parasite transmission: Aedes aegypti larvae and Plagiorchis noblei Cercariae

The effects of distributional patterns of the host on the acquisition of Plagiorchis noblei cercariae by Aedes aegypti larvae were determined. Mosquito larvae that were allowed to disperse were more susceptible to infection than confined larvae. Because these mosquito larvae are known to aggregate in light and disperse in darkness, they are more likely to acquire P. noblei infections at night. The timing of cercarial emergence in relation to the distributional patterns of the mosquito host is discussed.     

The C-terminal domain of eukaryotic protein synthesis initiation factor (eIF) 4G is sufficient to support cap-independent translation in the absence of eIF4E.

The foot and mouth disease virus, a picornavirus, encodes two forms of a cysteine proteinase (leader or L protease) that bisects the EIF4G polypeptide of the initiation factor complex eIF4F into N-terminal (Nt) and C-terminal (Ct) domains. Previously we showed that, although in vitro cleavage of the translation initiation factor, eIF4G, with L protease decreases cap-dependent translation, the cleavage products themselves may directly promote cap-dependent protein synthesis. We now demonstrate that translation of uncapped mRNAs normally exhibits a strong requirement for eIF4F. However, this dependence is abolished when eIF4G is cleaved, with the Ct domain capable of supporting translation in the absence of the Nt domain. In contrast, the efficient translation of the second cistron of bicistronic mRNAs, directed by two distinct Internal Ribosome Entry Segments (IRES), exhibits no requirement for eIF4E but is dependent upon either intact eIF4G or the Ct domain. These results demonstrate that: (i) the apparent requirement for eIF4F for internal initiation on IRES-driven mRNAs can be fulfilled by the Ct proteolytic cleavage product; (ii) when eIF4G is cleaved, the Ct domain can also support cap-independent translation of cellular mRNAs not possessing an IRES element, in the absence of eIF4E; and (iii) when eIF4G is intact, translation of cellular mRNAs, whether capped or uncapped, is strictly dependent upon eIF4E. These data complement recent work in other laboratories defining the binding sites for other initiation factors on the eIF4G molecule.