精索静脉曲张致男性不育机制的研究进展

精索静脉曲张(VC)是男性泌尿生殖系统中最常见的疾病之一,近年来其对男性生育的影响越来越受到重视,WHO已把VC列为男性不育的首要原因。目前对VC致男性不育的机制已进行了不少的实验研究,但其机制至今仍未完全阐明,因此探讨VC致男性不育的机制具有重要意义。现对近几年的研究成果予以综述。     

PUVA therapy damages psoriatic and normal lymphoid cells within milliseconds

Summary Results of previous investigations have indicated that photochemotherapy (PUVA) attacks membranes of target cells. Using the combination of a stopped-flow technique and laser irradiation we were able to prove that the fast PUVA effect is explainable solely by the membrane damage. Lymphoid cells of healthy persons or psoriatics were taken, within 1 ms mixed with 8-methoxy-psoralen (8-MOP) at concentrations of 1.0, 0.1, and 0.05 g/ml, and then irradiated by a 337-nm laser pulse (0.5 mJ/cm²) lasting some picoseconds. Approximately 1 ms after administration of 8-MOP to the cell surface at least 10% of the cells were damaged, as could be judged using the standard trypan blue exclusion test. This happened at 8-MOP concentrations of 1.0 or 0.1 g/ml plus laser irradiation, but a concentration of 0.05 g/ml 8-MOP plus laser exposure did not cause any effect within 8 ms after mixing. There was no difference between using lymphoid cells from healthy persons or from psoriatics. The fact that only a very short time is necessary before cell damage occurs means that, as far as the fast PUVA effect is concerned, a photochemical reaction involving nuclear DNA can be discounted.     

Isolation and characterization of yeast mutants with thermoconditional sensitivity to the bifunctional alkylating agent nitrogen mustard

Summary Selection of mutants of Saccharomyces cerevisiae sensitive to the DNA cross-linking agent nitrogen mustard (HN2) at two temperatures (23 °C and 36 °C) yielded two isolates with thermoconditionally enhanced (ts) sensitivity to the mutagen. Both were due to single recessive nuclear genes. Mutant allele snm1–2 ^ts showed mainly ts-sensitivity to HN2, whereas mutant allele snm2-1 ^ts conferred ts-sensitivity to HN2, half mustard (HN1) and UV. In temperature-shift experiments it was determined that the functions of SNM1 and SNM2 are needed for recovery within 6 to 7 h. after mutagen exposure during incubation at 23 °C on YEPD when HN2 and UV are applied. After HN1 treatment the SNM2 coded function is required for recovery for about 14 hrs. This possibly indicates a handling of UV- and HN2-induced lesions different from that of HN1-induced lesions.     

隔山消对功能性消化不良大鼠一氧化氮和胆碱酯酶的影响

目的　探讨隔山消对功能性消化不良 (FD)大鼠胃窦一氧化氮 (NO)和血清胆碱酯酶 (AchE)的影响。方法　采用夹尾刺激法制造FD模型 ,以多潘立酮作为对照 ,用不同剂量的隔山消进行治疗后 ,检测各组大鼠胃窦NO和血清AchE含量。结果　 0 .88g/kg剂量隔山消能使造模大鼠胃窦NO含量明显降低 ,血清中AchE活性升高。结论　隔山消治疗FD的机制可能与其降低大鼠胃窦NO含量有关。     

党参保质储藏包装材料和充气包装技术研究

为了探讨防止党参储藏过程中的虫蛀霉变方法,本文从用抽真空、充氮、充二氧化碳气体以及选用不同的包装材料,模拟不同的水分含温和温度条件筛选研究最佳的保质储藏包装材料和充气包装技术。结果表明:把党参含水量保持在15％,采用真空包装袋、充氮气或二氧化碳,或者直接用抽真空来降低氧浓度,进行密封储藏,保质时间最长,效果最好。     

0.7 MPa氮氧混合气对中枢γ-氨基丁酸能神经功能的影响

目的 观察0.7 Mpa氮氧混合气对中枢γ-氨基丁酸(GABA)能神经活动的影响.方法 采用液体闪烁技术,检测了0.7 Mpa氮氧混合气作用下SK-N-SH神经细胞GABA释放与摄取情况及GABA受体亲和力的变化.并采用半定量RT-PCR检测了GABA受体的mRNA表达变化.结果 0.7MPa氮氧混合气作用下,SK-N-SH神经细胞释放GABA增强,摄取减少,GABA受体亲和力下降,GABA受体mRNA表达无明显变化.结论 0.7 Mpa氮氧混合气作用下,中枢GABA能神经功能减弱.     

Dentate gyrus and spatial behaviour

This article reviews evidence from studies employing colchicine-induced granule cell loss in the adult rat brain, and irradiation-induced hypoplasia of the neonatal dentate gyrus, on the performance of spatial and non-spatial behavioral tasks. The general picture emerging from this analysis reveals that the dentate gyrus granule cells are critically involved in spatial behavior, particularly when this requires the adoption of place strategies. This notion also provides an explanation for the behavioral effects of dentate gyrus granule cell loss seen in apparently non-spatial tasks.     

Effect of fat proportion to glucose in peripheral parenteral nutrition on nutritional status in normal rats

The purpose of this study was to determine the optimal fat proportion to glucose in peripheral parenteral nutrition (PPN). PPN solutions consisting of dextrose + amino acids + fat (0%, 10%, 20%, 30%, 40% or 50% of total energy as fat) were administered parenterally at a rate of 120 kcal/kg/day for 5 days to normal rats, after which the effects on the nutritional status were assessed. Body weight change and cumulative nitrogen balance during the 5 day PPN period tended to increase with increasing fat dose until the 40% fat group. Serum triglyceride (TG), phospholipid (PL), free fatty acid (FFA) and total cholesterol (T-CHO) levels increased with increasing fat dose. Specifically, PL, T-CHO and FFA levels in the 50% fat group were especially higher than that in the normal group. Although the rats were administered with the same composition and dose of amino acid, serum Thr, Trp, Ala and Pro levels tended to decrease with increasing fat dose, with serum Ala and Pro levels in the 50% fat group being lower than that in the normal group. Hepatic glycogen content also tended to decrease with increasing fat dose. These results suggest that gluconeogenesis in the liver is increased in the 50% fat group due to low dextrose dose. In the 40% fat group, although serum PL and T-CHO levels were significantly higher, hepatic glycogen content and serum Ala levels were not significantly different compared with 0% fat group. It was therefore concluded that the optimal fat proportion in the rats receiving an energy intake below the basal energy requirements is 40% of total energy as fat.     

0.7MPa 高气压下中枢神经甘氨酸能神经元功能的变化

目的 研究0．7MPa氮氧混合气对中枢神经甘氨酸能神经元活动的影响。方法用液体闪烁技术检测了0．7MPa氮氧混合气作用下SK—N—SH神经细胞甘氨酸释放摄取情况，以及甘氨酸受体亲和力的变化。用半定量RT-PCR检测了甘氨酸受体的mRNA表达情况。结果在0．7MPa氮氧混合气作用下，SK—N—SH神经细胞释放甘氨酸增强，摄取减少，甘氨酸受体亲和力下降，甘氨酸受体mRNA表达无明显变化。结论在0．7MPa氮氧混合气作用下，中枢神经甘氨酸能神经元功能减弱。     

Effects of Nitrate and Ammonium on Larvae of <Emphasis Type="Italic">Rana temporaria</Emphasis> from the Pyrenees

In order to investigate the effects of nitrate and ammonium on the amphibians in a pasture zone of the Catalonian Pyrenees, larvae of Rana temporaria from several ponds were exposed to different concentrations of nitrate (0–500 mg/L) and ammonium (0–1.2 mg/L). High concentrations of nitrate in the water caused mortality and reduced larval size of R. temporaria, whereas no effects on larvae were observed in ammonium conditions. The results suggest that, if the levels of nitrate reach about 100 mg/L, the possibility of survival of R. temporaria larvae may be reduced.