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11.
This study examined the possibility that amphetamine-induced stereotypy and facilitation of memory consolidation are both mediated by amphetamine's stimulation of dopaminergic activity in the caudate nucleus. In the first experiment, rats were given pairings of a tone and a shock followed by SC amphetamine (2 mg/kg). The amount of stereotypy and increased locomotor activity produced by the injection were measured immediately. Retention of the tone-shock association was evaluated 48 h later by observing the ability of the tone to suppress drinking. The degree of retention was significantly correlated with the amount of stereotypy but not with the amount of locomotion previously measured. In the second experiment, amphetamine was microinjected into the caudate nucleus (10 g/l) and its ability to produce the same three behavioral effects was examined. These injections produced increased stereotypy and improved retention, but no increase in locomotion. The correlation of memory facilitation with stereotypy and the fact that both were produced by intracaudate amphetamine suggest that they may be mediated by the same neuropharmacological substrate, namely amphetamine-induced release of dopamine in the caudate. 相似文献
12.
Inge Lues Richard Vinke Hans-Joachim Schümann 《Naunyn-Schmiedeberg's archives of pharmacology》1984,326(3):273-277
Summary The interaction between rauwolscine and angiotensin II was investigated in the isolated mesenteric artery of the rabbit. Rauwolscine, known as an antagonist at 2-adrenoceptors, did not induce contraction itself but interacted with angiotensin to produce a facilitated response of the vascular tissue. In the presence of rauwolscine, the contractile response of the tissue to angiotensin was markedly enhanced. The degree of facilitation appeared to be dependent on the rauwolscine concentration used rather than that of angiotensin. Moreover, rauwolscine induced a concentration-dependent increase in tension (pD2=6.8) in the presence of even subcontractile concentrations of angiotensin (10–10 mol/l). This effect was not attributable to an indirect action involving presynaptic catecholamines, as revealed by the use of tissue strips from animals pretreated with reserpine or after chemical sympathectomy. Furthermore, an interaction via the prostaglandin system was excluded by negative results obtained with indomethacin. The agonistic effect of rauwolscine was significantly attenuated by phentolamine (1/2) but not by prazosin (1) or phenoxybenzamine when applied for only a short time. The 2-antagonist BDF 6143 behaved like rauwolscine whereas the 1-antagonist corynanthine, a stereoisomer of rauwolscine, did not. The results indicate that the rauwolscine effect is mediated by a receptor with 2-characteristics. In general, angiotensin appears to interfere with some process which determines the expression of a drug's intrinsic effect.This study was supported by a grant of the Deutsche Forschungsgemeinschaft 相似文献
13.
饮食服务业从业人员乙型肝炎病毒感染动态研究 总被引:1,自引:0,他引:1
目的为了解泰安市饮食服务业从业人员乙型肝炎病毒感染状况。方法应用ELISA方法在1995~1999年对53434名饮食服务业从业人员进行了血清HBsAg、抗-HBc、HBeAg和抗-HBe检测。结果1995~1999年饮食服务业从业人员血清HBsAg、抗-HBc、HBeAg和抗-HBe总阳性率呈逐年下降趋势,依次为4.41%、3.88%、3.46%、2.86%和2.50%,其差异有显著意义(χ 相似文献
14.
21纪我国医药行业的创新与发展 总被引:3,自引:0,他引:3
在分析我国医药行业发展现状及存在问题的基础上,研究了加入WTO后医药行业所面临的机遇与挑战,以及当前医药企业技术创新存在的不足,提出了21世纪我国医药行业创新与发展的对策和建议。 相似文献
15.
Harry T. Whelan Lucy H. Kras Kutlan Ozker Dawn Bajic Meic H. Schmidt Yu Liu Lisa Ann Trembath Fusun Uzum Glenn A. Meyer Annette D. Segura B. David Collier 《Journal of neuro-oncology》1994,22(1):7-13
The use of PHOTOFRIN for photodynamic therapy of human gliomas has been studied by i.v. administration and laser photosensitization. Defining the uptake of PHOTOFRIN in the patient's tumor in comparison with the surrounding normal brain tissue is highly desirable for patient selection and study ofin vivo kinetics. We utilized a non-invasive approach to the detection of PHOTOFRIN uptake in brain tumors with111In-oxine radiolabeled PHOTOFRIN and external imaging and quantitation using a gamma camera. Biodistribution of111In-labeled PHOTOFRIN in 13 organs was determined in four dogs and 15 mice with gliomas.99mTc-DTPA was used as a control for nonspecific uptake. The greatest concentration of111In-PHOTOFRIN in the brain tumor occurred at 24 hours post i.v. administration. The brain tumor PHOTOFRIN uptake was seven times greater than that of normal brain. The decreased blood background at 72 hours made this the optimum time for imaging. Specific tumor tissue uptake of111In-PHOTOFRIN occurred, well beyond that resulting from blood-brain-barrier (BBB) breakdown. 相似文献
16.
We have described the epidemiological analysis of one aspect of the King's College Hospital computerised data base; namely initial intraocular pressure as an indicator of visual field loss. The methods involved the use of the four-fold table to determine sensitivity and specificity at different pressure levels. From these results (1) the changes in the pre and post test probability of field loss are calculated and (2) a sensitivity/specificity trade off curve or decision curve is constructed. In this way the optimal cut-off level or operating point for a population of specific type and composition can be determined. The factors concerned in decision making are always complex but such an approach allows a rational and quantifiable alternative to reliance on clinical impression and intuition. The results have significance in relation to decisions on the management of patients and on population screening programmes for glaucoma. 相似文献
17.
Low doses of oxytocin facilitate social recognition in rats 总被引:7,自引:0,他引:7
Social recognition of juveniles by adult male residents has been shown to be modulated by neurohypophyseal hormones. The decrease of social investigation behavior during a second encounter with the same juvenile serves as index for social recognition. In the present study it was found that low doses (0.09–6.0 ng · kg–1) of oxytocin (OXT) given subcutaneously dose dependently facilitated social recognition. The effect of OXT appeared specific, since no change in social investigation was found when a novel juvenile was tested during the second encounter. No disturbances of social recognition by the low doses of OXT could be detected, in contrast to higher doses of this hormone. Other neurohypophyseal hormones, vasopressin and vasotocin, did not facilitate social recognition when tested in the same range of low doses. 相似文献
18.
19.
Thyroid hormones are critical for the development and maturation of the central nervous system. Insufficiency of thyroid hormones during development impairs performance on tasks of learning and memory that rely upon the hippocampus and impairs synaptic function in young hypothyroid animals. The present study was designed to determine if perturbations in synaptic function persist in adult euthyroid animals exposed developmentally to insufficient levels of hormone. Pre- and postnatal thyroid hormone insufficiency was induced by administration of 3 or 10 ppm propylthiouracil (PTU) to pregnant and lactating dams via the drinking water from gestation day (GD) 6 until postnatal day (PN) 30. This regimen produced a graded level of hormonal insufficiency in the dam and the offspring. Population spike and population excitatory postsynaptic potentials (EPSP) were recorded at the pyramidal cell layer and the stratum radiatum, respectively, in area CA1 of hippocampal slices from adult male offspring. PTU exposure increased baseline synaptic transmission, reduced paired-pulse facilitation, and increased the magnitude of the population spike long-term potentiation (LTP). Phosphorylation of the extracellular signal-regulated kinases (ERK1 and ERK2) was increased as a function of LTP stimulation in slices from PTU-exposed adult animals. On the other hand, no differences in the basal levels of synaptic proteins implicated in synaptic plasticity (total ERK, synapsin, growth-associated protein-43, and neurogranin) were detected. These results reinforce previous findings of persistent changes in synaptic function and, importantly extend these observations to moderate levels of thyroid hormone insufficiency that do not induce significant toxicity to the dams or the offspring. Such alterations in hippocampal synaptic function may contribute to persistent behavioral deficits associated with developmental hypothyroidism. 相似文献
20.