Atropine effects on delayed discrimination performance of rats

The effects of atropine sulfate (ATS) and atropine methyl nitrate (ATM) on the conditional discrimination behavior of rats were investigated in eight-hour experimental sessions. Responding of rats was reinforced on either a lighted or a darkened lever depending on whether lights over both levers had been on during the preceding sample portion of the trial. Zero-delay and four-second-delay trials were randomly interspersed. Quality of performance was analyzed using the A' sensitivity measure of signal detection theory. Both drugs reduced both sensitivity and the percentage of trials on which responding occurred (percent response) below saline treatment levels. The two drugs did not reliably differ from each other in their effects on sensitivity during the zero-delay condition, but reliable differences between the two drugs emerged during the four-second-delay condition at doses above 0.8 mg/kg. Percent response recovered more rapidly for animals treated with ATS than responding occurred (percent response) below saline treatment levels. The two drugs did not reliably differ from each other in their effects on sensitivity during the zero-delay condition, but reliable differences between the two drugs emerged during the four-second-delay condition at doses above 0.8 mg/kg.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of chronic stress on plasma corticosterone, ACTH and prolactin

Rats were placed in a stressful environment for 24 hr per day and levels of plasma hormones were measured after varying numbers of days in the environment. Rats were habituated to operant chambers placed in sound-attenuated enclosures. Food pellets were available by lever press on a FR1 schedule. After 3 days of habituation, rats in the “stressed” group were trained to pull a ceiling chain to avoid or escape shock. Following training, stress trials, consisting of a consecutive sequence of 5 sec each of a warning light, warning tone and 0.16, 0.32, 0.65, 1.3 and 2.6 mA of footshock, occurred approximately once per 5 min around-the-clock. For the first day, the sequence was terminated when the ceiling chain was pulled. On subsequent days, 90% of all shock presentations could be avoided or escaped by chain pull; the remaining 10% of trials were inescapable and the entire sequence was presented. Control rats lived in identical chambers without presentation of shock. Rats were sacrificed after 1, 2, 3, 4, 7 or 14 days in this environment and levels of plasma corticosterone, ACTH and prolactin were determined. Levels of plasma corticosterone were elevated during the first 7 days in the stressful environment, but returned to control values by day 14. Levels of plasma ACTH and prolactin were similar in stressed and control rats at all time points measured. These data suggest that stress-induced changes in glucocorticoids but not in ACTH or prolactin might mediate some of the physiological changes that occur as the result of chronic stress.     

Evidence for microvascular thrombosis obtained by intravital fluorescence videomicroscopy

A pattern of enlarged capillaries densely packed with red cells and not filled by the intravital dye Na-fluorescein for 10-20 min is described. Probably it corresponds to microvascular thrombosis. Alternative explanations like prolonged stasis appear unlikely. Up to now the pattern has been detected in severe chronic venous incompetence, collagen vascular disease and essential thrombocytosis.     

Ultrastructural morphology of early cellular changes in the synovium of primary synovial chondromatosis.

Synovial tissues taken from 13 cases of synovial chondromatosis (SC) were examined by light and electron microscopy. In three of the 13 cases, early cellular changes were observed by electron microscopy. Most of the foci were independently situated within an accumulation of fine, homogenous chondroid matrix in the sublining area of the synovium. Basal laminalike material was observed in these cells. Because this material was not apparent in the mature cartilage cells, the authors postulate that the basilaminar material affects cellular cytodifferentiation in SC during the initial phase of the disease. Ultrastructurally, these cells are morphologically similar to myofibroblasts. However, proliferation of paravascular cells with distinct basal laminae and activated secretory abilities was observed around some of the vessels. These paravascular cells may be the precursor cells of the prechondroblastic cells with basal laminalike material seen in SC.     

Formation of a tablet: a site and bond percolation phenomenon.

The concepts of percolation theory are used to elucidate the formation of a tablet by compression of particulate matter. The process of compaction can be considered as a combination of site and bond percolation phenomena. Because of effects of different particle size and shape of the particles in a powder bed and effects of brittle fracture and plastic flow, moisture content of the powder, and finite size of the tablet, no sharp percolation thresholds are expected. Thus, it is interesting to test the validity of the fundamental equation of percolation theory: the power law X = S(p - pc)q, where X is the system property, S is the scaling factor, p is the site occupation or bond formation probability, and q is the critical exponent. This model is, in certain cases, only rigorously valid close to the percolation threshold (range, [+/- 0.1 pc]). Combination of the Heckel equation with an equation derived earlier for the properties (X) of tensile strength (sigma t) and deformation hardness (P) yields a power law with q = 1, S'(sigma t) = sigma tmax/(1 - pc), and S(P) = Pmax/(1 - pc). With respect to the simplifying assumptions made, the power law agrees well with the experimental results obtained. Substantial improvements in the interpretation of the compression-compaction process are possible with these findings, and some interpretations differ from previous ones in earlier publications.     

Microencapsulated pancreatic islets: a pathologic study.

Dog pancreatic islets isolated by an enzymatic digestion method were encapsulated in an alginate-poly L-lysine-alginate membrane. These microencapsulated pancreatic islets were cultured in vitro to study their ability of insulin secretion. Portions of these in vitro-cultured microencapsulated pancreatic islets were taken out for a viability dye exclusion study as well as for pathologic studies to correlate them with insulin secretion ability. We found that there was a strong correlation between them. Good insulin-secreting microcapsules showed well-preserved cell membranes and beta-cell granules. An in vitro culture for one to two days in RPMI-1640 made the islets more stable, the cellular surface became smoother and the beta-granules were in better shape. The microencapsulated pancreatic islets were also injected into the peritoneum of streptozotocin-induced diabetic CDF1 mice. Blood glucose levels dropped and stayed low for up to 60 days. But, when non-encapsulated dog pancreatic islets were used, the blood glucose levels remained low for only about 14 days. A small portion of the injected microcapsules were washed out at specific times for pathologic study. Up to 28 days after injection, only a few of the injected microcapsules showed pericapsular cellular infiltrate. However, after 56 days, most of the microcapsules showed dense pericapsular cellular infiltrate. Immunohistochemical analysis of these infiltrates showed that the majority of cells were fibroblasts and macrophages. Most of the cells located in the inner portion of the infiltrate were fibroblasts, while the macrophages were located mainly on the outer portion. Both scanning and transmission electron microscopy showed that the surface of the microcapsule outer wall was much smoother than the inner wall. The size of the microcapsules was approximately 0.6-0.8 mm and the thickness of the wall measured around 10 nm. The smaller the microcapsule is, the less chance there is of rupture with release of the xenographic islets. Once the wall of the transplanted microcapsules was ruptured, the inner surface showed more increased inflammatory cell and fibroblast infiltration than the outer surface.     

α_1肾上腺素能受体阻滞剂萘哌地尔治疗慢性非细菌性前列腺炎的临床研究

目的:探讨α1肾上腺素能受体阻滞剂萘哌地尔(Naftopidil)治疗慢性非细菌性前列腺炎的有效性及安全性。方法:采用开放、自身对照、多中心的临床试验方法,应用萘哌地尔25mg,每日1次,对106例慢性非细菌性前列腺炎(NBP)患者进行了为期4周的治疗。以美国国立卫生院慢性前列腺炎症状评分(NIHCPSI)、前列腺液(EPS)WBC计数及最大尿流率(MFR)为疗效指标,对其有效性及安全性进行观察。结果:服药4周后,可评价病例105例。全组患者NIHCPSI总评分治疗前后平均减低12.0分(P<0.001),症状评分平均减低7.9分(P<0.001),生活质量评分平均减低4.1分(P<0.001)。EPS中WBC计数治疗前及治疗后分别为(15.2±15.1)、(9.5±12.0)个/HP(P<0.01)。MFR治疗前及治疗后分别为(19.2±4.8)、(22.7±4.9)ml/s(P<0.01)。按症状改善评价,治愈2例(1.9%),显效32例(30.5%),有效55例(52.4%),无效16例(15.2%)。总显效率为32.4%,总有效率为84.8%。3例有轻度头晕,1例食欲不佳,不良事件发生率3.81%。结论:萘哌地尔治疗慢性非细菌性前列腺炎安全、有效。     

北方汉族人群维生素D受体基因Bsm I位点多态性与前列腺癌易感性的相关性分析

目的 :研究低发病的中国汉族人群维生素D受体基因 (VDRG)BsmⅠ 位点单核苷酸多态性 (SNP)与前列腺癌的关系 ,探讨不同种族前列腺癌发病的基因差异。　方法 :收集中国北方地区汉族人群 10 3例前列腺癌病人及10 6例健康对照者外周血标本 ,应用变性高效液相色谱 (DHPLC)检测VDRG第 8内含子BsmⅠ多态位点 ,并对该位点SNP分布进行分析。　结果 :BsmⅠ 多态位点bb、Bb、BB基因型和等位基因在北方地区汉族前列腺癌病人及对照者中的分布频率差异无显著性 (P >0 .0 5 ) ,基因型分布频率分别为 92 .2 3%、7.77%、0和 94.34 %、5 .6 6 %、0 ;等位基因B、b分别为 3.88%、96 .12 %和 2 .91%、97.0 9%,而与高发病人群的分布相比有显著不同。　结论 :VDRGBsmⅠ多态性在低发病的中国汉族人群与前列腺癌无相关 ,其分布与高发病人群有明显差异 ,提示VDRGBsmⅠ多态性可能是前列腺癌发病种族差异的原因之一。