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931.
932.
Julian Willibald Stefanie Breukers Anjan Patel Christer L. Øpstad Stine Nalum Naess Vassilia Partali 《Chemistry and physics of lipids》2009,161(1):32-37
Stable cationic carotenoid aggregates — predominantly of the J-type — develop when the hydrochlorides of carotenoid aldoximes and ketoximes are exposed to water. The oxime hydrochlorides are obtained by simple syntheses from commercially available food color carotenoids. Bluish-purple, unstable transient compounds were observed during hydrochlorination performed at liquid nitrogen temperature. 相似文献
933.
Employing the techniques of in-vitro lymphocyte transformation (LTF) and using Putnam strain of rubella virus as the antigen, the development of rubella specific cellular immune response was studied in different age groups of rubella seronegative normal subjects at various intervals after subcutaneous administration of HPV=77/DE5 live attenuated rubella vaccine. The rubella specific lymphocyte response in children ranging in age from two to twelve years was characterized by significant LTF activity at two months, followed by a gradual decrease. The response in adult subjects 18 to 35 years of age showed a slight delay initially in the appearance and the maximum LTF activity appeared to be 3--4 fold lower (P less than 0.01) than observed in the children. No difference was observed in the maximum antibody titers to rubella virus between these two groups of subjects. These observations suggest that the age related differences in the lymphoproliferative responses might be associated with adverse effects which are known to occur more frequently in adolescent and older patients than in childhood population after vaccine induced rubella infection. 相似文献
934.
Oligonucleotide phosphorothioates have been synthesized using procaryotic DNA polymerase and oligonucleotide template/primer.
The method facilitates the recovery of DNA polymerase and template/primer and is successful at the milligram scale.
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
935.
A 15-year-old female rhesus monkey was observed to have bilaterally thinned and prominently curved corneas. Slit lamp observations, pachymetry, keratometry, and corneoscopy were consistent with a diagnosis of keratoconus, a relatively common corneal dystrophy in humans heretofore not described in a subhuman primate. 相似文献
936.
937.
938.
Multiple kinases and signal transduction. Phosphorylation of the T cell antigen receptor complex 总被引:19,自引:0,他引:19
Multiple kinases interact at the multicomponent murine T cell antigen receptor. Antigen induces serine phosphorylation of the 21-kDa gamma glycoprotein and tyrosine phosphorylation of p21, a distinct 21-kDa chain. We demonstrate that tyrosine phosphorylation is due to kinase activation, and that all phosphorylated p21 is associated with the antigen receptor. We also show that antigen leads to polyphosphoinositide metabolism and subsequent protein kinase C activation. The two phosphorylation events can be dissociated by protein kinase C depletion, which eliminates phorbol 12-myristate 13-acetate-induced serine but not tyrosine phosphorylation. Activation of a third kinase, cyclic AMP-dependent protein kinase, inhibits both serine and tyrosine events, yet this inhibition can be modulated by addition of the protein kinase C activator, phorbol 12-myristate 13-acetate. Receptor-mediated signal transduction may be understood as the interaction of multiple stimulatory and inhibitory kinase activities. 相似文献
939.
The effect of ochratoxin A on the specific activities of phosphoenolpyruvate carboxykinase, gamma-glutamyl transpeptidase and phosphate-dependent glutaminase were investigated in primary cultures of rat kidney proximal convoluted tubule cells grown in a serum-free medium supplemented with growth factors. Addition of ochratoxin A (25-100 microM) to the medium caused reduction in the specific activities of phosphoenolpyruvate carboxykinase and gamma-glutamyl transpeptidase only. Addition of cAMP caused a four-fold increase in the concentration of phosphoenolpyruvate carboxykinase mRNA in tubule cells within 3 h. This cAMP-mediated increase in phosphoenolpyruvate carboxykinase mRNA content was abolished when ochratoxin A was added simultaneously. 相似文献
940.
Latha Ramakrishnan Hélène Muller-Steffner Christophe Bosc Victor D. Vacquier Francis Schuber Marie-Jo Moutin Leslie Dale Sandip Patel 《The Journal of biological chemistry》2010,285(26):19900-19909
Cyclic ADP-ribose and nicotinic acid adenine dinucleotide phosphate are ubiquitous calcium-mobilizing messengers produced by the same family of multifunctional enzymes, the ADP-ribosyl cyclases. Not all ADP-ribosyl cyclases have been identified, and how production of different messengers is achieved is incompletely understood. Here, we report the cloning and characterization of a novel ADP-ribosyl cyclase (SpARC4) from the sea urchin, a key model organism for the study of calcium-signaling pathways. Like several other members of the ADP-ribosyl cyclase superfamily, SpARC4 is a glycoprotein targeted to the plasma membrane via a glycosylphosphatidylinositol anchor. However, unlike most other members, SpARC4 shows a remarkable preference for producing cyclic ADP-ribose over nicotinic acid adenine dinucleotide phosphate. Mutation of a single residue (tyrosine 142) within a noncanonical active site reversed this striking preference. Our data highlight further diversification of this unusual enzyme family, provide mechanistic insight into multifunctionality, and suggest that different ADP-ribosyl cyclases are fine-tuned to produce specific calcium-mobilizing messengers. 相似文献