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141.
The subcellular distribution of the blood group antigen A in the transitional epithelium of the urinary tract and its neoplastic growths was studied using transmission immuno-electronmicroscopy. Sixty-five tissue specimens from 50 blood group A1 patients were processed according to an immunogold procedure which was optimized for preservation of both antigen and ultrastructure. The reactions were stronger in the glycocalyx of the luminal surfaces and at the interdigitating cytoplasmic processes of the cells. In the intracellular compartment the reactions were associated with tubulovesicular membrane-bound structures and with the Golgi complexes. Secretory products, intra- or extra-cellular, were also positive. The greatest variability was noted in the cell surface reactions, which were positive in 88% of normal but only 41% of neoplastic urothelial specimens. An inverse correlation was found between malignant behaviour and cell surface, but not intracellular, reactions. We conclude that, in transitional cell carcinomas, there is a quantitative defect in the processing of substance A which affects predominantly the cell surface component and may involve either the transport-insertion steps, the plasma membrane-associated glycosyltransferases or internalization of blood group antigen A. 相似文献
142.
Perfusion is a crucial physiological parameter for tissue function. To obtain perfusion-weighted images and consequently to measure cerebral blood flow (CBF), a newly developed flow-sensitive alternating inversion recovery (FAIR) technique was used. Dependency of FAIR signal on inversion times (TI) was examined; signal is predominantly located in large vessels at short TI, whereas it is diffused into gray matter areas at longer TI. CBF of gray matter areas in the human brain is 71 ± 15 SD ml/100 g/min (n = 6). In fMRI studies, micro- and macrovessel inflow contributions can be obtained by adjusting TIs. Signal changes in large vessel areas including the scalp were seen during finger opposition at a TI of 0.4 s; however, these were not observed at a longer TI of 1.4 s. To compare with commonly used BOLD and slice selective inversion recovery techniques, FAIR and BOLD images were acquired at the same time during unilateral finger opposition. Generally, activation sites determined by three techniques are consistent. However, activation of some areas can be detected only by FAIR, not by BOLD, suggesting that the oxygen consumption increase couples with the CBF change completely. Relative and absolute CBF changes in the contralateral motor cortex are 53 ± 17% SD (n = 9) and 27 ± 11 SD ml/100 g/min (n = 9), respectively. 相似文献
143.
144.
目的 无水茶碱修筛缓释片——优喘平(portheo)治疗可逆性支气管阻塞患者(FEV_1<预计值80%)30例。观察其疗效及安全性,同时监测其STLD(血清浓度),并与氨茶碱片口服后STLD进行比较。结果显示;优喘平治疗哮喘及慢性阻塞性肺病疗效达90.6%,三例有轻微副作用。优喘平服用后4小时STLD即达有效浓度,8小时后STLD多维持在有效水平,峰值多<20ug/ml。氨茶碱0.1/次,3次/日,连服4天后STLD谷值多<5ug/ml,0.2/次,3次/日,连服4天后STLD谷值均>5ug/ml,峰值均>20ug/ml,且多有较重毒付作用。优喘平0.4/次,1次/日与氨茶碱0.1/次,3次/日比较,疗效好,而比氨茶碱0.2/次,3次/日,毒付反应少。优喘平与氨茶碱有显著差异。(P<0.01)。 相似文献
145.
N. Z. Klyueva D. B. Ryzhov S. V. Kulikov S. K. Churina 《Bulletin of experimental biology and medicine》1997,124(2):751-753
Injection of a synthetic analog of parathyroid hypertensive factor to WKY rats considerably increases and prolongs pressor
response to adrenaline. Synthetic analog injected after adrenaline induces a short-term (3–4 min) and potent (to 250%) rise
of arterial pressure. Each subsequent injection of the synthetic analog induces a less pronounced in the amplitude and duration
pressor response. The α-adrenoblocker phentolamine completely abolishes the effects of the parathyroid hypertensive factor
analog.
Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 124, No. 8, pp. 148–150, August, 1997 相似文献
146.
手术联合中药治疗激素性股骨头缺血性坏死的实验研究 总被引:5,自引:0,他引:5
目的 :初步探讨激素性股骨头缺血性坏死的发病机制 ,观察手术 +中药治疗本病的疗效。方法 :通过对新西兰大白兔联合应用马血清 +甲基强的松龙造模及手术处理 ,对正常组、模型组、手术组、手术 +中药组实验兔的血脂、血液流变学、血生化及股骨头标本切片观察 ,分析比较。结果 :手术 +中药治疗本病的疗效优于单纯保髋手术。结论 :手术 +活血化瘀补肾壮骨方法是股骨头缺血性坏死治疗的合理方法 相似文献
147.
Summary A rapid and quantitative method for the determination of benzodiazepines using high-performance liquid chromatography (HPLC)
with diode-array detection (DAD) is reported. The drugs were extracted from serum, blood or post-mortem blood using C18 extraction columns. Brotizolam was used as internal standard. Experiments with spiked serum/blood samples resulted in recoveries
between 75% and 94% for all investigated benzodiazepines. Excellent linearity was obtained over the concentration range 5–1500
ng benzodiazepine/ml. The limit of detection was approximately 2 ng/ml. The detection of low therapeutic serum levels of highly
potent benzodiazepines is also possible.
相似文献
148.
Gerhard Adam Jrg Neuerburg Elmar Spüntrup Andreas Mühler Kira Scherer Vet Surg Rolf W. Günther 《Journal of magnetic resonance imaging : JMRI》1994,4(3):462-466
Gadolinium-DTPA (diethylenetriaminepentaacetic acid)-cascade-polymer, a potential new blood pool contrast agent for magnetic resonance (MR) imaging, was compared with a known blood pool agent, Gd-DTPA-polylysine, in an animal model. The relative signal intensities of liver, renal cortex, pancreas, and trunk muscle were assessed in 12 pigs between 4 seconds and 120 minutes after injection of a 20 μmol/kg dose of each contrast agent, by using a FLASH (fast low-angle shot) sequence. Except for muscle, all tissues showed visible enhancement after injection of either contrast agent. After injection of Gd-DTPA-polymer, enhancement patterns in the liver, renal cortex, and pancreas were similar to those seen after injection of Gd-DTPA-polylysine. No statistically significant differences in enhancement between the two contrast agents were found at any time point. The authors conclude that the contrast kinetics of Gd-DTPA-cascade-polymer are similar to those of Gd-DTPA-polylysine and that this agent may also be used as a blood pool contrast agent for MR imaging. 相似文献
149.
150.
An innocuous sensory event (a prestimulus) that briefly precedes a startle-eliciting stimulus (SES) will reduce the amplitude
of the subsequently elicited reflex. In three experiments brief silent periods in otherwise continuous noise (gaps) were used
as prestimuli to investigate the effects of the D1 dopamine receptor agonist (±)-SKF-38393 (SKF) and the dopamine D2 receptor group agonist (−)-quinpirole hydrochloride on gap inhibition of the rat’s acoustic startle reflex. Gap durations
of 4 and 50 ms were analyzed. Quinpirole (0–1.6 mg/kg) had a biphasic effect on gap inhibition. Lower doses increased gap
inhibition, an effect that peaked at the 0.4 mg/kg dose. For higher doses, inhibition returned to control levels for the 4-ms
long gap, but remained elevated for the 50-ms long gap. SKF had no effect on gap inhibition, and haloperidol (0.2 mg/kg) reversed
the quinpirole-induced increase of gap inhibition. These data implicate the D2 dopamine receptor group in gap inhibition of startle modulation. The results are discussed in terms of the effects of catecholamine
agonists on attention.
Received: 25 July 1995/Final version: 28 April 1997 相似文献