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1.
We have developed a procedure for Vibratome (Oxford Laboratories) sections that is particularly valuable for providing uniformly thick, well preserved CNS tissue sections for morphometric applications. 相似文献
2.
Diazepam (5 mg/kg, ip) and tracazolate (40 mg/kg, ip), a nonbenzodiazepine anxiolytic, blocked electrically-induced head-turning without producing sedation. Bicuculline and picrotoxin, GABA antagonists, at doses not affecting head-turning (2 mg/kg, ip) antagonized the effects of diazepam and tracazolate on head-turning. However, at the same dose, bicuculline was more effective as an antagonist of diazepam whereas picrotoxin was more effective as an antagonist of tracazolate. These results suggest that benzodiazepine as well as nonbenzodiazepine anxiolytics possess GABAmimetic activity. The difference in potency between bicuculline and picrotoxin as antagonists of diazepam and tracazolate may be related to their reported differences as GABA antagonists (e.g., site of receptor interaction). 相似文献
3.
4.
Chandan J. Gurusinghe Michael J. Hickey John V. Hurley Bernard McC. O'Brien 《The Histochemical journal》1993,25(2):140-143
Summary An immunohistochemical method using formalin-fixed, paraffin wax-embedded sections is described for detecting strain-specific major histocompatibility complex class I antigens in knee-joint tissue from DA and Lewis strains of rat. The fixed osteochondral tissues were additionally decalcified in formic acid before processing for paraffin wax embedding. For immunohistochemistry, two monoclonal antibodies, one specific for DA class I allele RT1Aa and the other for Lewis class I allele RT1A1, were used together with the avidin-biotin immunoperoxidase procedure. It was necessary to use strain-specific normal rat serum as a diluent for the antibodies to suppress cross-strain recognition. DA-specific antibody stained positively only on DA rat sections, not on Lewis rat sections, and Lewis-specific antibody stained positively only on Lewis rat sections, and not on DA. Positive staining was localized in the bone marrow, osteochondral cells and endothelium. We propose that the use of a decalcification medium may have enhanced the immunoreactivity of the tissue. The method described can be used on sections of allografts from the two strains of rat to assess morphologically the extent of cellular replacement of the graft by the host's cells. 相似文献
5.
A simple neural network model is proposed for kindling — the phenomenon of generating epilepsy by means of repeated electrical stimulation. The model satisfies Dale's hypothesis, incorporates a Hebb-like learning rule and has low periodic activity in absence of shocks. Many of the experimental observations are reproduced and some new experiments are suggested. It is proposed that the main reason for kindling is the formation of a large number of excitatory synaptic connections due to learning. 相似文献
6.
Linda E. Malick Anna Tompa Charles Kuszynski Parviz Pour Robert Langenbach 《In vitro cellular & developmental biology. Plant》1981,17(11):947-955
Summary The maintenance of primary cultures of adult hamster pancreatic cells on layers of irradiated C3H/10T1/2 cells was studied.
Various types of pancreatic cells, acinar, islet and ductular cells could be identified in the cultures by light and electron
microscopy. Morphologically the various pancreatic cells retained many differentiated characteristics of their respective
in vivo cell types. Insulin production was maintained at near Day 1 levels for the 16 d in culture for which it was measured.
Colonies of epithelial cells continued to grow during a 20 d culture period. It is believed that this procedure for maintaining
functional and growing pancreas cells in culture may be a useful in vitro model for studying the initiation of pancreatic
carcinogenesis.
Supported by Grant R01 CA 20022 and Contract N01 CP33278 from the National Cancer Institute, National Institutes of Health,
Bethesda, Maryland. 相似文献
7.
Methionine- and leucine-enkephalin were found to be potent, short-acting analgesics in the tail flick test in rats following intracerebral administration, via chronically indwelling cannulae, into the midbrain periaqueductal gray. Morphine sulfate was approximately 4 times as potent as the enkephalins when infused into this same brain site. The analgesia produced by the enkephalins and by morphine was inhibited by pretreatment with naloxone. 相似文献
8.
The incorporation of [35S]methionine into ovalbumin, a protein containing NH2-terminal N-acetylglycine, has been studied in chicken oviduct magnum cells. The purification of [35S]methionine-labeled ovalbumin from total oviduct proteins was accomplished by dialysis of a crude extract at pH 3.6 followed by chromatography on carboxymethyl cellulose. The radioactive ovalbumin eluted from the column in three peaks (P0, P1, and P2-containing 0, 1, and 2 moles of phosphate, respectively, per mole of ovalbumin). The kinetics of labeling of peaks P0 and P1 showed that the ratio of radioactivity in NH2-terminal methionine to total incorporation was greater at 2 min of labeling than at later times. The transient labeling of the NH2-terminus of ovalbumin with methionine indicates that methionine is the initiator amino acid for the synthesis of this protein, which in its mature form contains NH2-terminal N-acetylglycine. 相似文献
9.
Substance P was found to be a potent, long-lasting analgesic in the tail flick test in rats following intracerebral administration, via chronically indwelling cannulae, into the midbrain periaqueductal gray. Substance P was approximately five times as potent as morphine sulfate on a weight basis; however, it was 25 times more potent than morphine on a molar basis. The analgesic activity produced by Substance P was significantly antagonized by pretreatment with naloxone, a narcotic antagonist. The analgesic activity of Substance P exhibited a rapid onset (1 min.), peaked by 3 minutes post infusion and its duration of activity was between 30 and 60 minutes. Thus, Substance P may be yet another endogenous analgesic peptide. 相似文献
10.