Unilateral adrenal mass due to Mycobacterium kansasii in an AIDS patient

Infection with Mycobacterium kansasii in patients with acquired immunodeficiency syndrome usually involves the lung or disseminated infection. We report a case of infection with M kansasii confined to the adrenal gland and possibly to an adjacent vertebral body that presented as a fever of undetermined origin.     

Distinct UV-B and UV-A/blue light signal transduction pathways induce chalcone synthase gene expression in Arabidopsis cells

UV and blue light control the expression of flavonoid biosynthesis genes in a range of higher plants. To investigate the signal transduction processes involved in the induction of chalcone synthase (CHS) gene expression by UV-B and UV-A/blue light, we examined the effects of specific agonists and inhibitors of known signaling components in mammalian systems in a photomixotrophic Arabidopsis cell suspension culture. CHS expression is induced specifically by these wavelengths in the cell culture, in a manner similar to that in mature Arabidopsis leaf tissue. Both the UV-B and UV-A/blue phototransduction processes involve calcium, although the elevation of cytosolic calcium is insufficient on its own to stimulate CHS expression. The UV-A/blue light induction of CHS expression does not appear to involve calmodulin, whereas the UV-B response does; this difference indicates that the signal transduction pathways are, at least in part, distinct. We provide evidence that both pathways involve reversible protein phosphorylation and require protein synthesis. The UV-B and UV-A/blue light signaling pathways are therefore different from the phytochrome signal transduction pathway regulating CHS expression in other species.     

Comparison of relative risks of urinary stone formation after surgery for ulcerative colitis: conventional ileostomy vs. J-pouch. A comparative study

The main techniques which have been used to study skin microcirculation in patients with peripheral arterial occlusive disease include intravital microscopy with and without the use of fluorescent dyes, laser Doppler fluxmetry and transcutaneous oximetry. In patients with severe ischaemia (rest pain or incipient gangrene) the number of perfused skin capillaries is reduced. Parallel to the decreased number of microvessels containing blood, transcutaneous oxygen tension is low or even approaches the zero level. The tendency to oedema formation is documented by increased leakage of intravenously injected sodium fluorescein at the capillary apex of foot skin ('candlelight phenomenon'). Laser Doppler flux at rest may still be within the normal range even in advanced disease, since the sample volume of these instruments also contains non-nutritive shunt vessels. However, reactive hyperaemia after arterial occlusion is decreased and delayed in peripheral ischaemia. Whereas rhythmic low-frequency vasomotion is significantly enhanced in patients with intermittent claudication, vasoparalysis with no flux fluctuations prevails in patients with critical ischaemia.     

D-(+)-iso-methanocarbathymidine: a high-affinity substrate for herpes simplex virus 1 thymidine kinase

The stereoselective syntheses of the (+)-D and (-)-L enantiomers of iso-methanocarbathymidine (iso-MCT) was achieved through two independent linear approaches that converged on two antipodal enantiomers, common to a key precursor used in the synthesis of racemic iso-MCT. In the study reported herein we identified (+)-3 [D-(+)-iso-MCT] as the active enantiomer that was exclusively recognized by the herpes simplex virus 1 thymidine kinase (HSV1-tk), as was predicted by molecular modeling. For this purpose, a human osteosarcoma (HOS) cell line modified to contain and express HSV1-tk from herpes simplex virus 1 (HSV1) was used to determine the cytotoxicity of the compounds by an assay that measures the level of ATP in the cells. The work demonstrates that changes in the substitution pattern of rigid bicyclo[3.1.0]hexane nucleosides, which, relative to normal nucleosides, appear unconventional, can lead to the spatial optimization of pharmacophores and vastly improved substrate recognition.     

Gas chromatography-mass spectrometry methods for structural analysis of fatty acids

Procedures for structural analysis of fatty acids are reviewed. The emphasis is on methods that involve gas chromatography-mass spectrometry and, in particular, the use of picolinyl ester and dimethyloxazoline derivatives. These should be considered as complementing each other, not simply as alternatives. However, additional derivatization procedures can be of value, including hydrogenation and deuteration, and preparation of dimethyl disulfide and 4-methyl-1,2,4-triazoline-3,5-dione adducts. Sometimes complex mixtures must be separated into simpler fractions prior to analysis by gas chromatography-mass spectrometry. Silver ion and reversed-phase high-performance liquid chromatography are then of special value. In particular, a novel application of the latter technique, involving a base-deactivated stationary phase and acetonitrile as mobile phase, is described that is suited to the separation of fatty acids in the form of picolinyl ester and dimethyloxazoline derivatives, as well as methyl esters.