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191.
Unilateral ureteral obstruction (UUO) is a representative model for investigating the common mechanism of decreasing renal function in chronic renal failure. In this study, we present a new partial UUO model in adult rats and evaluated the effect of beraprost sodium (BPS: stable prostaglandin I2 (PGI2) analog). We could make reproductive and uniform partial UUO by ligating the left ureter together with a 0.5 mm diameter stainless steel wire with nylon thread, and withdrawing the stainless wire. One week later, the ureteral obstruction was released. After 3 weeks from the release of UUO, all animals of control group, without BPS administration, developed basophilic degeneration of tubular epithelium, tubular dilatation and interstitial fibrosis. The areas of tubular degeneration and fibrosis were significantly reduced in the BPS group, orally administered BPS 300 μg/kg twice a day from the next day of the release of obstruction, than in control group.In conclusion, we can established the adult rat partial UUO-release model and revealed that BPS can inhibit renal tubular damage and tubulointerstitial fibrosis.  相似文献   
192.
目的:双侧慢性硬膜下血肿和单侧慢性硬膜下血肿患者的临床比较。方法:将33例双侧慢性硬膜下血肿和119例单侧慢性硬膜下血肿患者的临床表现、诱发因素、CT扫描、术后并发症和疗效进行回顾性对比分析。结果:单侧慢性硬膜下血肿组平均年龄67岁,双侧慢性硬膜下血肿组平均年龄71岁(P>0.05),两组患者均以男性多见(P>0.05)。与单侧慢性硬膜下血肿组相比,双侧慢性硬膜下血肿组头痛/呕吐更常见(P<0.05),使用抗凝/抗血小板药物患者较多(P<0.05),中线移位>5mm少于双侧慢性硬膜下血肿组(P<0.05)。两组患者合并的常见系统疾病、术后并发症和疗效无显著性差异(P>0.05)。结论:双侧慢性硬膜下血肿易发生于使用抗凝/抗血小板药物的老年患者,颅内压增高征更明显。两组大多数患者术后均恢复良好。  相似文献   
193.
Unilateral pollen-pistil incompatibility within the Brassicaceae has been re-examined in a series of interspecific and intergeneric crosses using 13 self-compatible (SC, Sc) species and 12 self-incompatible (SI) species from ten tribes. SC x SC crosses were usually compatible, SI x SC crosses showed unilateral incompatibility, while SI x SI crosses were often incompatible or unilaterally incompatible. Unilateral incompatibility (UI) is shown to be overcome by bud pollination or treating stigmas with cycloheximide — features in common with self-incompatibility. Treating stigmas with pronase prevents pollen tubes from penetrating the stigma in normally compatible intra-and interspecific pollinations. The results presented show that the presence of an incompatibility system is important in predicting the outcome of interspecific and intergeneric crosses and, combined with the physiological similarities between UI and SI, would suggest an involvement of the S-locus in UI.  相似文献   
194.
Summary We present evidence of a difference between a storing and non-storing species in lateralization and transfer of spatial memory processing. Using the technique of monocular occlusion, we compared the performance of a food-storing species, the marsh tit (Parus palustris), with a closely related species that does not store food, the blue tit (P. caeruleus), on a task which relies on one-trial learning for the spatial location of hidden food items. In this one-trial associative learning task, the birds had to return to sites in phase II of a trial where they had been allowed to eat some, but not all, of a piece of peanut in phase I. In the first experiment, in which the birds did not wear eye caps, marsh tits required fewer looks in phase II to find the hidden peanut than blue tits. By categorising the sites as seeded, unseeded or not visited in phase I, further analysis suggested that the two species also differ in the way they behave towards the 3 types of site. Marsh tits appear to distinguish between seeded and other sites, irrespective of whether the other sites were known to be empty (unseeded) or not (not visited); whereas blue tits preferentially returned to those sites that have been visited in phase I, irrespective of whether they contained a seed or not. In the second experiment, all birds wore an eye cap on the left or right eye for phase I and II of each trial. For both species, it was demonstrated that although the visual systems fed by both the right and left eye are involved in short-term storage, the right eye system is associated also with long-term storage. Thus, lateralization was found in both blue tits and marsh tits. However, unilateral transfer of these memories was found only in marsh tits, suggesting that there may be a difference between storers and non-storers in the mechanism of memory processing.  相似文献   
195.
摘要 目的:以血液流变学及男性性功能指标为主要观察指标分析微通道经皮肾镜取石术(MPCNL)与输尿管软镜碎石取石术(FURL)在输尿管上段结石(UUC)中的应用价值。方法:将80例男性UUC患者按简单随机化法分MPCNL组、FURL组各40例;比较两组清石率、血液流变学、性功能指标及不良反应。结果:两组术后1w(82.50% vs 85.00%)、术后1mo(92.50% vs 97.50%)、术后3mo(100.00% vs 100.00%)的清石率无统计学意义(P>0.05)。FURL组术后1天、术后7天的血液流变学指标水平均低于MPCNL组(P<0.05)。两组术后男性性功能指标较术前显著改善,但FURL组术后3mo、6mo的男性性功能指标改善更显著(P<0.05)。结论:对于UUC患者,MPCNL和FURL均能有效清除结石,都是安全有效的方法,但FURL较MPCNL对患者术后血液流变学的影响更小,且更利于术后性功能的恢复。  相似文献   
196.
Summary Unilateral incompatibility was discovered when crossing was attempted between different self-compatible types and subspecies of V. faba. Crossing in the direction female less self-fertile x male more self-fertile failed, whereas the reciprocal-crossing succeeded. Unilateral incompatibility developed with the evolution of less fertile and large seeded field bean types. How a cross fertilized (and self-incompatible) system may develop from a self fertilized one is discussed.The unilateral incompatibility in V. faba and other plant species is compared. The two-power competition hypothesis can explain all kinds of unilateral incompatibility reported so far in the literature. Breeding field beans for improved self-fertility is discussed.  相似文献   
197.
198.
脉冲梯度磁场(峰值磁场0.2~2.0T,梯度10~100T.M-1,脉冲宽度20~200ms,重复频率0.16~1.34HZ)抑制鼠恶性肿瘤的细胞增殖和诱导细胞凋亡,提高宿主细胞免疫功能和抑制肿瘤生长,阻塞供给肿瘤生长的新生血管。虽然进一步的清晰的机理研究是非常需要的,但是上面的发现能够成为治疗恶性肿瘤的一种新方法。  相似文献   
199.
大鼠肾间质纤维化动物模型的实验研究   总被引:24,自引:0,他引:24  
目的 观察单侧输尿管结扎 (UUO)大鼠模型中肾脏病理改变 ,肾组织α 平滑肌肌动蛋白 (α SMA)和纤维连接蛋白 (FN)表达的变化 ,证明UUO方法可快速制作理想的肾脏细胞转分化和间质纤维化动物模型。方法 大鼠随机分为假手术组 (SOR)和UUO组。随机选取各组中的 6只大鼠分别于单侧输尿管结扎术后 3天、 7天、 14天、 2 1天和 2 8天处死 ,收集血清与肾组织供生化及病理分析。结果 ① 2 4小时尿蛋白定量 ,UUO组与假手术组无统计学差异。UUO术后 7~ 14天 ,大鼠出现明显血尿素氮、肌酐值升高 ;术后 2 1~ 2 8天 ,血尿素氮、肌酐值反而下降 ,但 2 8天时血肌酐值仍然高于假手术组 (P <0 0 5 )。②UUO组肾小管间质损伤评分 (TIS)明显高于假手术组。UUO术后 3天 ,肾脏组织出现了早期纤维化的病理改变。随着梗阻时间延长 ,小管间质纤维化程度和间质细胞增殖、炎细胞浸润逐渐加重 ,皮质变薄十分明显。术后 2 8天 ,Masson染色见皮质区、皮髓交界处纤维化明显 ,但肾小球仍无明显病变。③免疫组化结果显示 ,UUO术后 3天肾间质α SMA阳性细胞数和FN表达增加 ,并随时间递增。UUO术后 7天 ,可见少许α SMA阳性的转分化小管上皮细胞 ;术后14天转分化的小管上皮细胞明显增多。α SMA表达与FN表达成正相关 (r=0 996 ,P <  相似文献   
200.
Intraspecific barriers promote outcrossing while interspecific mechanisms may contribute to the isolation of species; both control the exchange of genes between plants. In this paper we establish that post-pollination mechanisms promote outcross and act at different temporal and spatial levels to control seed set and quality in Quercus species. Controlled pollinations were performed to investigate intraspecific crossing barriers in Q. suber and pollen-pistil interactions following interspecific pollinations with some simpatric Quercus species. Cytological data of intraspecific crosses in Q. suber and Q. ilex have shown different kinetics on pollen tube growth after self and outcross pollination, but pollen tubes were able to reach the base of the styles in both species and seed set was successful. Although some pre-zygotic interaction is occurring at the style, the most important interaction takes place at ovary. The cross between Q. ilex and Q. suber is possible only in one direction, revealing a case of unilateral incongruity. We show that the lack of seed set observed in the cross Q. suber×Q. ilex is due to the inability of pollen tubes to penetrate the transmitting tissue after germination. With Q. suber mainly as female parent, pollinations with other simpatric Quercus species have shown different levels of constraint on pollen tube progression at stigma and style levels. Eventual hybridisation between Quercus species will depend on the compatibility of pollen-pistil interactions, on the competitive ability of pollen genotypes, and, most important, on the overlapping of geographical, phenological and ecological factors. Differences in seed set and seed allocation was evident in all crosses, and was particularly outstanding in interspecific and in self intraspecific crosses, determining the ultimate level of seed production and quality in Quercus species. Received: 4 April 2001 / Accepted: 8 May 2001  相似文献   
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