Simultaneous measurement of prednisone, prednisolone and 6β-hydroxyprednisolone in urine by high-performance liquid chromatography coupled with a radioactivity detector

We describe the first method for routine measurement of prednisone, prednisolone and 6β-hydroxyprednisolone concomitantly in urine. Urine (3 ml) is extracted with ethyl acetate, washed with base and separated by high-performance liquid chromatography on a silica column with a solvent system of hexane—diethyl ether—ethanol—tetrahydrofuran—glacial acetic acid (59.9:31:2.3:6.5:0.3, v/v). The steroids are detected at 254 nm. Because no conventional internal standard was found, 6β-[³H]hydroxycortisol and [³H]prednisolone are added to urine prior to extraction; ³H is monitored by a radioactivity detector coupled with the chromatograph. The assay exhibits linearity from 200 to 7500 ng and an inter-day variability of < 11.4% (C.V.).     

On the Phospholipid Metabolism of Glial Cell Primary Cultures: Cell Characterization and Their Utilization of 1-Alkyl-Glycerophosphoethanolamine

Abstract: Primary cultures prepared from newborn rat brain were grown for 16 or 17 days in culture. Addition of brain extract from newborn rats to the medium stimulated the maturation of astrocytes and the development of oligodendrocytes. Both cell types were characterized by morphology and by immunohistochemistry. The phospholipid composition of these cells was estimated. Incubations were performed with l-[³H]alkyl- sn -glycerophosphoethanolamine in varying concentrations for 3 h. About one-third of the substrate supplied was internalized by the cells. Several enzymic reactions were observed. The acylating enzyme system was the most active one—a K _m was determined with 5 nmol intracellular 1-alkyl- sn -glycerophosphoethanolamine/mg cell protein. Plasmalogen formation was rather low. 1-Alkyl- sn -glycerol, a hydrolysis product, was found in small amounts. Some radioactivity was also incorporated into the phosphatidylcholine fraction.     

Simian Immunodeficiency Virus (SIV) from Sun-Tailed Monkeys (Cercopithecus solatus): Evidence for Host-Dependent Evolution of SIV within the C. lhoesti Superspecies

Recently we reported the characterization of simian immunodeficiency virus (SIVlhoest) from a central African l'hoest monkey (Cercopithecus lhoesti lhoesti) that revealed a distant relationship to SIV isolated from a mandrill (SIVmnd). The present report describes a novel SIV (SIVsun) isolated from a healthy, wild-caught sun-tailed monkey (Cercopithecus lhoesti solatus), another member of the l'hoest superspecies. SIVsun replicated in a variety of human T-cell lines and in peripheral blood mononuclear cells of macaques (Macaca spp.) and patas monkeys (Erythrocebus patas). A full-length infectious clone of SIVsun was derived, and genetic analysis revealed that SIVsun was most closely related to SIVlhoest, with an amino acid identity of 71% in Gag, 73% in Pol, and 67% in Env. This degree of similarity is reminiscent of that observed between SIVagm isolates from vervet, grivet, and tantalus species of African green monkeys. The close relationship between SIVsun and SIVlhoest, despite their geographically distinct habitats, is consistent with evolution from a common ancestor, providing further evidence for the ancient nature of the primate lentivirus family. In addition, this observation leads us to suggest that the SIVmnd lineage should be designated the SIVlhoest lineage.     

Novel, Starch-Like Polysaccharides Are Synthesized by an Unbound Form of Granule-Bound Starch Synthase in Glycogen-Accumulating Mutants of Chlamydomonas reinhardtii

We isolated two muskmelon (Cucumis melo) cDNA homologs of the Arabidopsis ethylene receptor genes ETR1 and ERS1 and designated them Cm-ETR1 (C. melo ETR1; accession no. AF054806) and Cm-ERS1 (C. melo ERS1; accession no. AF037368), respectively. Northern analysis revealed that the level of Cm-ERS1 mRNA in the pericarp increased in parallel with the increase in fruit size and then markedly decreased at the end of enlargement. In fully enlarged fruit the level of Cm-ERS1 mRNA was low in all tissues, whereas that of Cm-ETR1 mRNA was very high in the seeds and placenta. During ripening Cm-ERS1 mRNA increased slightly in the pericarp of fruit before the marked increase of Cm-ETR1 mRNA paralleled climacteric ethylene production. These results indicate that both Cm-ETR1 and Cm-ERS1 play specific roles not only in ripening but also in the early development of melon fruit and that they have distinct roles in particular fruit tissues at particular developmental stages.     

A vaccine strategy utilizing a combination of three different chimeric vectors which share specific vaccine antigens

A large number of recombinant of viral and bacterial systems have been engineered as vectors to express foreign genes for vaccination and/or gene therapy. A common problem is the immune response to the vector itself. The presence of anti-vector immune responses may preclude sufficient 'priming' or immunogenicity if pre-existing immune responses are present, or they may impair optimal 'boosting' upon repeated immunization or delivery with the same vector. To circumvent this problem we developed a strategy using different chimeric vectors which share only the expression of common specific antigens desired for immunization. This approach not only has the advantage of avoiding increased anti-vector responses, but allows the use of combinations of vectors which could subsequently present the same or related antigen differently to the immune system as well as at alternative sites to induce the optimal type of immunity against the pathogen of interest.