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991.
The prevalence of Salmonella spp. in nestling common barn-owls was investigated in southwestern New Jersey during the summer of 1985. Of 94 owls sampled by swabbing the cloaca, eight (8.5%) were found to harbor Salmonella spp. Three serotypes--S. thompson, S. tuindorp, and S. typhimurium--were identified. Five (20%) of the 25 nest sites examined (all of them in or near farm buildings or dwellings) contained Salmonella-positive owls.  相似文献   
992.
993.
994.
The effect of interleukin-1 beta on the production of non-prostanoid vasoactive factors by cultured rat aortic smooth muscle cells was investigated. Under bioassay conditions, the perfusate from a column of confluent cells grown on beads and treated with interleukin-1 beta (1 ng/ml for 18 to 24 hr) abolished the contraction of a canine coronary ring without endothelium contracted by phenylephrine (1 microM), while the perfusate from control cells had no effect. The relaxing activity of the perfusate was observed when transit times were increased from 1 sec to 5 min. Nitro L-arginine (100 microM) reversed the relaxations and L-arginine stereoselectively restored the relaxations. Interleukin-1 beta (1 ng/ml) evoked a time-dependent accumulation of cyclic GMP but not cyclic AMP in cultured smooth muscle cells. The transfer of fresh or stored (-70 degrees C) conditioned culture medium from interleukin-1 beta-treated cells but not from control cells, to cultured smooth muscle cells stimulated the production of cyclic GMP. These observations demonstrate that interleukin-1 beta induces the production of transferable factor which relaxes vascular smooth muscle and stimulates the production of cyclic GMP.  相似文献   
995.
996.
997.
Whereas zoospores of six cultures of O. brassicae were immobile after treating in glycine solution at 35–40°C for 10 min, those of a cucurbit culture of O. radicale were immobile only after heating at 45°C. Further, O. radicale multiplied in cucumber at 20°, 30° and 35°C, whereas O. brassicae multiplied at 20°, but not 30° or 35°C. Such differences in reaction to temperature might sometimes be useful in separating mixtures of the two species in common hosts such as cucumber.  相似文献   
998.
Several types of NS cells were identified in Portunus sanguinolentus--five types (A, A', B, C and D) in the brain and thoracic ganglion, four types (A, B, C and D) in the commissural ganglia and four types (alpha, beta, gamma and delta) in the optic ganglia. The distribution of these NS cells is described. Cytochemically, the neurosecretory material in the NS cells has a carbohydrate moiety and is rich in disulphide groups, lipids, phospholipids and RNA. It contains a small amount of sulphydryl groups and protein-bound NH2 groups, but no tyrosine or tryptophan. The NS activity of the brain was found to be closely associated with the reproductive and moult cycles. Just before the initiation of vitellogenesis and moulting the NS cells display secretory hyperactivity. Axonal transport of NS material was also observed in the NS cells.  相似文献   
999.
1000.
The importance of protein phosphorylation at tyrosyl hydroxy groups in the control of cell proliferation has recently been established. For identification of tyrosine-phosphorylated proteins, monoclonal antibodies (Mabs) against artificial immunogens containing O-phosphotyrosine (pTyr) or tripeptide pTyr-Gly-Gly as haptens were generated; the haptens were coupled to carrier proteins (bovine serum albumin, human immunoglobulin, keyhole limpet hemocyanin). After immunization of mice with pTyr coupled to keyhole limpet hemocyanin, Mabs were generated which were highly specific for pTyr and did not cross-react with O-phosphoserine, O-phosphothreonine, tyrosine or nucleoside-5'-monophosphates. The Mabs specifically react with tyrosinephosphorylated proteins in the Rous sarcoma virus-transformed rat XC-cell.  相似文献   
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