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41.
作者对核糖体现有的制备方法进行了部分改进,从黄疸出血群赖型017株钩体中成功地制备了核糖体提取物。该提取物经SPA-ELISA 证实具有免疫原性,对40只受试豚鼠的保护试验结果表明,核糖体提取物对同型毒株的攻击具有明显的保护作用;结果还证明核糖体提取物能诱导机体的体液免疫反应。 相似文献
42.
Hydroxocobalamin is a rapid and powerful antidote in acute cyanide poisoning. The effects of hydroxocobalamin (0.1, 0.3, and 1 mM) on intrinsic myocardial contractility were studied on isolated rat cardiac papillary muscles (n=10). Whatever the concentration, hydroxocobalamin did not modify the active isometric force and a slight increase in maximum unloaded shortening velocity was noted at 1 mM. Only 0.3 mM significantly impaired contraction-relaxation coupling under low load, suggesting a slight decrease in sarcoplasmic reticulum function. No changes in contraction relaxation coupling under heavy load were noted, suggesting the lack of modification of myofilament calcium sensitivity. These results suggest that hydroxocobalamin does not induce noticeable changes in intrinsic myocardial contractility. An indirect mechanism might be involved in the previously reported decrease in cardiac function at supratherapeutic concentrations of hydroxocobalamin. 相似文献
43.
同型半胱氨酸对胚胎海马神经元细胞的影响 总被引:1,自引:1,他引:0
目的 观察同型半胱氨酸(homocysteine,HCY)对海马神经元细胞分化和增殖的作用机理。方法 采用大鼠胚胎海马神经元细胞进行体外培养。观察不同浓度的HCY(0.01、0.1、1.0、10.0、100.0)mmol/L对细胞分化和增殖的影响。结果 随着剂量的增加.同型半胱氨酸对胚胎海马神经元细胞分化和增殖具有抑制作用,并用流式细胞术分析证明对脂质过氧化(LPO)的影响而使得神经元蛋白质含量增高。结论 同型半胱氨酸可抑制胚胎海马神经元细胞分化和增殖的影响,HCY可能在导致神经管畸形的过程起着重要作用。 相似文献
44.
Correlation between sperm penetration into the human zona pellucida and in vitro fertilization rates
L. Yogev PhD R. Gamzu R. Hauser A. Botchan A. Amit J. B. Lessing G. Paz and H. Yavetz 《Andrologia》1997,29(2):71-75
Summary. Sperm penetration into the zona pellucida of unfertilized oocytes, and its correlation with in vitro fertilization rates of the sibling oocytes, were assessed. This was performed in order to evaluate the prediction rate of the sperm penetration test into the zona pellucida. Unfertilized oocytes ( n =1872) from 371 cycles were pipetted through a microcapillary, and the remaining sperm cells penetrating the zona pellucida were counted. The mean (±SD) number of spermatozoa that penetrated the zona pellucida of unfertilized oocytes was 12.9±16.37. A significant correlation was found between the fertilization rate and the mean number of spermatozoa that penetrated into the zona pellucida of the unfertilized sibling oocytes (r = 0.48; P < 0.001), or the percent of unpenetrated zonae pellucidae in a cohort (r= —0.43; P < 0.001). However, a distinct variation in the number of spermatozoa that penetrated into the zona pellucida was detected. A step-wise regression analysis proved the number of spermatozoa penetrating the zona pellucida to be more predictive for fertilization rates than the variable of percent of unpenetrated zonae pellucidae. The results imply that although there is interdependence between penetration into the zona pellucida and fertilization rate, the predictive value of sperm penetration test for prognosis and future management after the first in vitro fertilization attempt, is limited. 相似文献
45.
Abstract: To perform the first experimental tests for validation of a new gear unit concept, the pump chamber, diaphragm, and pusher plate design of an orthotopic electromechanical total artificial heart (TAH) (Helmholtz Labtype) was manufactured. In its early stage of development, it provides some of the most important features of the conceptual final artificial heart. The new gear unit transforms a uniform unidirectional rotational motor movement into translatory pusher plate movements, with resting phase in the end–diastolic position, and the angled pump chamber orientation determines the available space for the motor and gear unit. Furthermore, this labtype provides flexibility with regard to use of different types of structural parts for experimental investigations. The first in vitro test results, obtained with specially designed circulatory mockloops that simulate physiological preload and afterload conditions, are presented. They comprise pressure and flow generation, motor performance, efficiency, and energy consumption. The results prove the feasability of the new gear unit concept for an electromechanical artificial heart and allow a reliable determination of the necessary performance of the future brushless DC motor for the first in vivo TAH model. 相似文献
46.
对天津市新近临床分离的414株细菌进行了甲氟哌酸(Pflx)和氟哌酸(Nflx)体外抗菌活性研究。结果显示Pflx对绝大多数肠杆菌和细菌、不动杆菌有良好抗菌活性,抑菌率>90%。对绿脓杆菌、MSSA及凝固酶阴性葡萄球菌有中度抗菌作用,抑菌率分别为85%、87.5%、87.5%。对MRSA和链球菌抗菌活性稍差,抑菌率在40%~68.42%之间。Nflx体外抗菌活性和Pflx相似。此外,18例药敏试验耐Pflx和Nflx细菌感染患者,经Pflx治疗,肺化脓症1例显效,余17例难治性尿路感染者1例痊愈、9例显效、5例进步、2例无效。 相似文献
47.
Previously, we determined the pattern of stress-induced c-fos mRNA expression throughout the brain in order to gain further insight into the identification of the neural circuits mediating stress-induced regulation of the hypothalamic-pituitary-adrenal axis. In the present study, we determined if rapid effects of increased glucocorticoid levels after stress contribute to changes in c-fos mRNA expression. To this end, stress-induced c-fos expression was characterized in adrenalectomized (ADX) or adrenalectomized and corticosterone replaced (ADX/B) male rats. Animals were sacrificed 30 min post-onset of a 10 min swim stress, and in situ hybridization histochemistry was used to detect c-fos mRNA throughout the brain. The pattern of c-fos induction in the ADX and ADX/B animals was similar to that observed in the sham operated animals. Additionally, densitometric measurements were made to quantify the c-fos response in the paraventricular nucleus of the hypothalamus and the CA1/2 region of the hippocampus. We found that ADX did not alter the magnitude of the c-fos response to stress in these areas, but there was a slight dampening of the response in ADX/B animals. In sum, these results suggest that the pattern of c-fos expression observed 30 min post-stress is independent of stress-induced increases in circulating glucocorticoid concentrations. 相似文献
48.
阴道毛滴虫代谢产物体外对精子活力的影响 总被引:1,自引:0,他引:1
目的 :研究阴道毛滴虫代谢产物体外对人精子活力的影响。 方法 :阴道毛滴虫体外培养 ,除去虫体 ,留取培养液 ,稀释成三个浓度 ;将 10例正常生育男性的优化精子分为等体积的 4份 ,组成以下 4组 :A组加入未培养滴虫的空白培养液 ,B ,C ,D组依次加入前述浓度梯度的培养液 (1.2× 10 9/L、6× 10 8/L、1.2× 10 8/L) ,分别于 30s、1、2、4和 6h时采用计算机辅助精子分析系统 (CASA)分析精子运动参数。 结果 :阴道毛滴虫浓度在 6× 10 8/L以上时 ,精子的活率和活力与对照组相比都显著降低 (P <0 .0 5 ) ,并呈浓度依赖性和时间依赖性。 结论 :阴道毛滴虫代谢产物体外能抑制精子活力 ,可能是造成不孕不育的原因之一。 相似文献
49.
氯喹敏感与抗性株恶性疟原虫对青蒿琥酯、克林霉素及其联用的体外敏感性 总被引:3,自引:0,他引:3
目的 为了解氯喹敏感和抗性株恶性疟原虫对青蒿琥酯、克林霉素及其二联用的敏感性。方法 运用Rieckmann体外微量法测定原虫对药物的敏感性。结果 氯喹敏感株恶性疟原虫对青蒿琥酯、克林霉素及青/克联用的ID50分别为2.8、3784.7及6.4/2046.6nmol/L;抗性株原虫对上述药物的ID50分别为8.1、1652.1及2.35/1409.4nmol/L。结论 抗氯喹恶性疟原虫对克林霉素无交叉抗性。青蒿琥酯与克林霉素联用在体外测定中,其抗疟作用对抗性株明显优于敏感株。 相似文献
50.
N. R. Saunders A. Deal G. W. Knott Z. M. Varga† J. G. Nicholls † 《Clinical and experimental pharmacology & physiology》1995,22(8):518-526
1. Repair and recovery following spinal cord injury (complete spinal cord crush) has been studied in vitro in neonatal opossum (Monodelphis domestica), fetal rat and in vivo in neonatal opossum. 2. Crush injury of the cultured spinal cord of isolated entire central nervous system (CNS) of neonatal opossum (P4–10) or fetal rats (E15–E16) was followed by profuse growth of fibres and recovery of conduction of impulses through the crush. Previous studies of injured immature mammalian spinal cord have described fibre growth occurring only around the lesion, unless implanted with fetal CNS. 3. The period during which successful growth occurred in response to a crush is developmentally regulated. No such growth was obtained after P12 in spinal cords crushed in vitro at the level of C7–8. 4. In vivo, in the neonatal (P4–8) marsupial opossum, growth of fibres through, and restoration of, impulse conduction across the crush was apparent 1–2 weeks after injury. With longer periods of time after crushing a considerable degree of normal locomotor function developed. 5. By the time the operated animals reached adulthood, the morphological structure of the spinal cord, both in the region of the crush and on either side of the site of the lesion, appeared grossly normal. 6. The results are discussed in relation to the eventual longterm possibility of devising effective treatments for patients with spinal cord injuries. 相似文献