苦豆子总碱的体外抗菌活性研究

目的：了解苦豆子总碱的体外抗菌活性,方法：以琼脂稀释法、试管稀释法、活菌计数法检测苦豆了总碱的体外最低抑菌浓度（ＭＩＣ）及最低杀菌浓度（ＭＢＣ）等。结果：苦豆子总碱体外对１０余种２０６株试验菌均有抑菌作用,其ＭＩＣ是１０～４０ｍｇ／ｍｌ,大于３～５ＭＩＣ的浓度对上述试验菌有杀菌作用。苦豆子总碱在碱性环境下抑菌作用较强,细菌接种量可影响其ＭＩＣ,血清含量对ＭＩＣ无明显影响。结论：苦豆子总碱有广谱抗菌     

Prefrontal activation in preschool children is associated with maternal adversity and child temperament: A preliminary fNIRS study of inhibitory control

Exposure to adversity is a well-documented risk factor for cognitive, behavioral, and mental health problems. In fact, the consequences of adversity may be intergenerational. A growing body of research suggests that maternal exposures to adversity, including those prior to childbirth, are associated with offspring biobehavioral development. In a sample of 36 mothers and their preschool-age children (mean child age = 4.21 ± 0.92 years), we used functional near-infrared spectroscopy to replicate and extend this work to include brain activation during inhibitory control in young children. We found that measures of maternal exposure to adversity, including cumulative, childhood, and preconception exposures, were significantly and positively associated with activation in the right frontopolar prefrontal cortex (PFC) and in the left temporal and parietal clusters during inhibitory control. In addition, and consistent with previous findings, children's increased negative affect and decreased effortful control were associated with increased right PFC activation during inhibitory control. These findings provide preliminary evidence that maternal and dispositional risk factors are linked to alterations in PFC functioning during the preschool years. Children of mothers with a history of exposure to adversity, as well as children who are less temperamentally regulated, may require increased neural resources to meet the cognitive demands of inhibitory control.     

九头狮子草的抗菌作用研究

采用平板打孔法,分别用九头狮子草全草的乙提取和水浓缩得到的药液药,在营养琼脂培养和基和ＬＢ培养基上筛出敏感细菌。结果表明九头狮子草对金黄色葡萄球菌、溶血性链球菌、、肺炎克雷伯菌有较强的抑制作用。     

Chronic treatment with MK-801 affects the behavioral response to both D1 and D2 dopamine agonist in the one-trial inhibitory avoidance

Post-training administration of theN-methyl-d-aspartate (NMDA) antagonists CPP (0.5 and 1.0 mg/kg) and MK-801 (0.25 and 0.5 mg/kg) impaired, in a dose dependent fashion, the one-trial inhibitory avoidance response in NMRI mice. The D₁ dopamine (DA) agonist SKF 38393 (10 and 20 mg/kg) and the D₂ agonist quinpirole (0.5 and 1.0 mg/kg) instead facilitate the response in the same behavioral paradigm. Sub-chronic blockade of NMDA receptors with MK-801 (0.25 mg/kg once a day for 14 days) did not change the response to both competitive (CPP) and non-competitive (MK-801) NMDA antagonists. The same chronic treatment with MK-801 induced an increased response to both SKF 38393 and quinpirole. These data suggest that repeated administration of MK-801 induce an upregulation of both D₁ and D₂ DA receptors without affecting NMDA receptors.     

LIF对体外培养小鼠孕早期胚胎发育及ICAM-1表达的影响

目的研究白血病抑制因子（ＬＩＦ）在胚胎发育中的作用并探讨其参与胚泡着床的机制。方法收集昆明种小鼠的单细胞受精卵,连续培养１２０ｈ,观察不同浓度ＬＩＦ对胚胎发育的影响;用免疫印迹法测定培养液中细胞间粘附分子（ＩＣＡＭ－１的表达水平。结果ＬＩＦ在０．１～１０ｎｇ／ｍｌ浓度之间对胚胎发育有促进作用,其作用在桑椹胚及胚泡期最明显（Ｐ＜０．０５）;ＬＩＦ增加胚胎ＩＣＡＭ－１的表达,其作用在０．１ｎｇ／ｍｌ浓度时最强,并随着浓度的增加而减弱。结论适应浓度的ＬＩＦ可促进胚胎发育,增加ＩＣＡＭ－１的表达,从而参与胚胎着床过程。     

Role of gonadotrophin releasing hormone baseline concentrations in the control of pituitary gonadotrophin and ovarian steroid secretion in the pseudopregnant rat

To study the effect of moderately elevated gonadotrophin releasinghormone (GnRH) baseline concentrations during the luteal andthe follicular phase, pseudopregnant rats were infused s.c withGnRH at several doses for 5 days. These rats were also treatedwith oestradiol or sham-treated during the last 3 days of GnRHtreatment GnRH infusions started on day 7 or day 3 of the lutealphase of the ovulatory cycle; in the rat, the luteal phase orpseudopregnancy lasts about 10 days. Luteinizing hormone (LH)and follicle stimulating hormone (FSH) responses were inducedby i.v. injection of GnRH on day 12 (after expected luteolysis)or on day 8 (before expected luteolysis). In normal rats theLH and FSH responses induced by GnRH on day 12 were higher thanon day 8 (160 and 50% respectively). In GnRH-infused rats theLH and FSH responses were not increased. In these rats the lutealphase was extended (the plasma progesterone concentrations remainedhigh) and the onset of the follicular phase was postponed (plasmaoestrogen concentrations did not increase). Oestradiol increasedthe day 12 LH and FSH responses; this effect of oestradiol wassuppressed by GnRH infusion. On day 8, exogenous oestradiolalso increased the LH and FSH responses, but again the effectof oestradiol was suppressed when the animals were concomitantlyinfused with GnRH. These data may suggest that in the rat, GnRHbaseline concentrations participate in the neuroendocrine systemcontrolling gonadotrophin secretion and hence the ovulatorycycle.     

Erythromycin succinate in the treatment of acute exacerbations of chronic bronchitis

Summary In 20 patients with an acute exacerbation of chronic respiratory tract infection the effectiveness of oral erythromicin succinate 3×500 mg daily has been tested. The duration of treatment was 10 days in all cases. The criteria of success, in addition to the clinical findings, were the results of bacteriological investigations and assessment of the appearance of the sputum. In all patients sputum and serum concentrations or erythromicin were determined. All pathogens isolated from the sputum of the patients were erythromicin-sensitive. One instance of development of resistance was observed. The drug was well tolerated.     

Variability in behavioral responses to benzodiazepines in the rat

The effects of chlordiazepoxide (10 mg/kg) were assessed in a holeboard by the reductions in head-dipping, rearing and locomotor activity; the correlations among all these measures were significant. Test-retest correlations were significant for all but the time spent head-dipping. On the basis of their behavioral responses to chlordiazepoxide six "strong" and six "weak" responders were identified and used for an in vitro electrophysiological study. There were no differences between the two groups in the extent to which flurazepam potentiated muscimol, but picrotoxin showed a greater antagonism of muscimol in slices from "strong" responders and flurazepam showed a greater reduction of picrotoxin potency. There was a significant correlation between the in vitro picrotoxin shift and the chlordiazepoxide-induced reduction in locomotor activity. The correlations between behavioral responses to chlordiazepoxide and the plasma benzodiazepine concentrations were low and only one (for locomotor activity) reached significance.     

The pharmacokinetics and pharmacodynamics of lisuride in healthy volunteers after intravenous,intramuscular, and subcutaneous injection

Summary The plasma concentration of lisuride and prolactin have been measured in twelve healthy male volunteers after IV, IM or SC injection of 25 g lisuride hydrogen maleate as an aqueous solution.After IV administration the plasma lisuride fell in two phases with half-lives of 14 min and 1.5 h. Total clearance was 13 ml·min^–1·kg^–1. After IM and SC injection the plasma concentrations peaked at 12 to 15 min and the profiles were similar to that found after IV administration. The systemic availabilities were 90% and 94%, respectively. Prolactin concentrations were reduced by a maximum of 60% relative to the normal circadian rhythm after all three routes of administration.The treatments were well tolerated, the only adverse reactions reported by some of the volunteers being mild, transient dizziness, tiredness, and nausea.     

Divalent Cations Modulate the Inhibitory Substrate Properties of Murine Glia-derived J1-160 and J1-180 Extracellular Matrix Glycoproteins for Neuronal Adhesion

J1-160 and J1-180 are developmentally late appearing J1 extracellular matrix glycoproteins derived from oligodendrocytes. They prevent adhesion of neurons (but not of astrocytes or fibroblasts) when offered as a substrate in mixture with laminin (Pesheva et al., J. Cell Biol., 109, 1765 - 1778, 1989). In the present study we have examined the influence of divalent cations on the inhibitory substrate properties of J1-160/180 glycoproteins towards adhesion of neurons. By metal chelate affinity chromatography, we show that J1-180, but not J1-160, binds Ca2+, while both J1 components are capable of binding Zn2+ and other divalent metal ions. Divalent cation binding was observed by gel filtration, aggregation assays with coated latex beads and electron microscopic examination to elicit aggregation of the molecules. Divalent cation binding also affects their non-permissive substrate properties towards neurons from early postnatal mouse cerebellum. Without divalent cations, J1-160 and J1-180 are inhibitory for substrate adhesion of neurons independently of the adhesive substrate present (laminin or poly-l-lysine). This effect is neutralized when J1-180 is preincubated with Ca2+ or Zn2+ prior to coating as substrate. In contrast, preincubation with Ca2+ ions does not affect the inhibitory substrate properties of J1-160 under these conditions. These observations show that J1-160/180 molecules may undergo self-aggregation in a divalent cation-dependent mechanism, which correlates with the neutralization of their inhibitory effect on neuronal adhesion. The aggregation state of the molecules may thus influence the process of myelination by a homophilic binding mechanism and determine the effectiveness of neurite extension during central nervous system development and under traumatic conditions in the adult.