N-硝基-L-精氨酸甲酯对氧惊厥发作的影响

目的:探讨一氧化氮合酶(NOS)抑制剂N-硝基-L-精氨酸甲酯(L-NAME)对脑型氧中毒(氧惊厥)发作的影响。方法:SD大鼠40只,分为氧惊厥组、生理盐水对照组、L-NAME组和氮-氧混合气组。L-NAME在高压氧暴露前10min腹腔注射用药。观察各组大鼠氧惊厥始发时间(ITC)、惊厥严重程度(SOC)和存活时间(ST)。结果:氧惊厥和生理盐水对照组的ITC、SOC、ST无显著性差异,应用L-NAME后,ITC、ST明显延长(P<0.01),SOC显著下降(P<0.01)。结论:高压氧暴露前10min应用L-NAME可延长氧惊厥发作的潜伏期和生存时间,降低氧惊厥的严重程度,具有预防氧惊厥的作用。     

高氧液对急性脑梗死患者甲襞微循环及血液流变学的影响

目的探讨高氧液对脑梗死患者甲襞微循环及血液流变学的影响,评价高氧液对脑梗死的治疗作用.方法脑梗死患者86例,随机分为常规治疗组(Ⅰ组)和常规治疗+高氧液治疗组(Ⅱ组).治疗前后观察患者的甲襞微循环和血液流变学.结果Ⅰ组治疗前后甲襞微循环和血液流变性改变均具有显著性差异(P0．05)，Ⅱ组治疗前后比较具有非常显著性差异(P<0．01)。Ⅱ组较Ⅰ组治疗前后甲襞微循环及血液流变性改善明显，两组间差异显著(P<0．05)。结论高氧液可以改善脑梗死患者甲襞微循环及血液流变性，高氧液静脉输液给氧是治疗脑梗死安全有效的新方法。     

高氧液对急必脑梗死患者甲襞微循环及血液流变学的影响

目的探讨高氧液对脑梗死患者甲襞微循环及血液流变学的影响,评价高氧液对脑梗死的治疗作用.方法脑梗死患者86例,随机分为常规治疗组(Ⅰ组)和常规治疗+高氧液治疗组(Ⅱ组).治疗前后观察患者的甲襞微循环和血液流变学.结果Ⅰ组治疗前后甲襞微循环和血液流变性改变均具有显著性差异(P0．05)，Ⅱ组治疗前后比较具有非常显著性差异(P<0．01)。Ⅱ组较Ⅰ组治疗前后甲襞微循环及血液流变性改善明显，两组间差异显著(P<0．05)。结论高氧液可以改善脑梗死患者甲襞微循环及血液流变性，高氧液静脉输液给氧是治疗脑梗死安全有效的新方法。     

4-对二甲氨基酚和缺氧对犬高铁血红蛋白及心电信号的影响

目的探讨4-对二甲氨基酚（4-DMAP）对常氧和缺氧犬外周血高铁血红蛋白（MHb）、PQ间期（PQd）和QRS间期（QRSd）等参数的作用差别。方法四川杂种家犬12只,随机分为常氧组、缺氧低、中、高剂量组,每组3只。常氧组吸入空气,缺氧组吸入81.8%：18.2%氮-氧混合气体,1 h后为动物肌肉注射4-DMAP,常氧组注射剂量为3.25 mg/kg,缺氧低、中、高剂量组注射剂量分别为1.95、3.25、5.00 mg/kg,取静脉血测定MHb含量,记录Ⅱ导联心电图,测量PQd、QRSd。结果注射等剂量4-对二甲氨基酚（3.25 mg/kg）后,缺氧组血液MHb含量明显高于常氧组（P〈0.05）,且一直维持在较高水平;注射3.25 mg/kg的4-对二甲氨基酚后,动物PQd缩短,QRSd延长,缺氧状态时更为明显。结论缺氧可加强4-对二甲氨基酚形成高铁血红蛋白的能力及其对心脏的副作用。     

桂皮醛对NIH3T3细胞c-Fos、c-Myc表达的影响

目的： 研究肉桂主要成分桂皮醛刺激NIH3T3细胞后c-Fos、c-Myc蛋白在不同时点表达的规律，探讨桂皮醛促进NIH3T3细胞增殖的机制。方法: 采用 MTT法观察不同浓度桂皮醛对NIH3T3细胞增殖的影响；并采用免疫细胞化学法检测桂皮醛对NIH3T3细胞c-Fos、c-Myc蛋白表达的影响。结果: 桂皮醛浓度在（8.8×10^-2）-（8.8×10）μg/L浓度范围内对NIH3T3细胞具有促增殖作用。当其浓度为5.5 μg/L时，促增殖作用最显著。在此浓度下，经桂皮醛刺激后，c-Fos和c-Myc蛋白均在2 h开始表达，3 h时表达明显增加。结论: 桂皮醛可以上调c-Fos、c-Myc蛋白的表达，提示桂皮醛促进细胞增殖可能与其能促进c-Fos、c-Myc快速表达有关。     

检测耐甲氧西林葡萄球菌及其耐药性分析

为了解我院耐甲氧西林葡萄球菌（MRS）的感染情况及其耐药性,为临床治疗MRS感染提供实验室依据和有效的用药措施．用微生物鉴定仪检测了142株葡萄球菌对13种抗生素的MIC,对苯唑青霉素MIC＞2ug／ml的菌株,采用K－B纸片法,补充检测对苯唑青毒素纸片的耐药性,共筛选出80株MPS,其中耐甲氧西林金黄色葡萄球菌（MRSA）20株,耐甲氧西林表皮葡萄球菌（MRSE）33株,其它耐甲氧西林葡萄球菌27株,说明感染我院的MRS种类不断增加,应引起重视．药散结果表明MRS对万古霉素（Van）100％敏感,对其他抗生素的敏感性明显低于对甲氧西林敏感的葡萄球菌（MSS）,因此,临床上应区分MRS与MSS,选择性地用药．     

早期治疗妊娠期甲状腺功能亢进对母婴的身体健康影响分析

目的 探讨妊娠期甲状腺功能亢进妇女早期治疗对母婴健康的影响.方法 回顾性分析我院2011年至2013年收治的88例妊娠期合并轻中度甲亢患者的临床资料,根据患者治疗方案分为甲硫咪唑组(28例)、丙硫氧嘧啶组(28例)和对照组(32例),比较三组妊娠妇女妊娠期间的疾病变化情况及母婴情况.结果 ①治疗后三组患者FT3、FT4、TSH水平差异具有统计学意义(P＜0.05),并且甲硫咪唑治疗组和丙硫氧嘧啶治疗组患者的FT3、FT4、TSH水平差异具有统计学意义(P＜0.05);②三组新生儿FT3、FT4、TSH水平差异具有统计学意义(P＜0.05),并且甲硫咪唑治疗组和丙硫氧嘧啶治疗组新生儿FT3、FT4、TSH水平差异具有统计学意义(P＜0.05);③两治疗组患者妊高症发生率、早产发生率和平均分娩孕周与对照组比较差异均具有统计学意义(P＜0.05),并且甲硫咪唑治疗组和丙硫氧嘧啶治疗组患者的平均分娩孕周差异具有统计学意义(P＜0.05);④甲硫咪唑治疗组和丙硫氧嘧啶治疗组新生儿低体重出生率、胎儿窘迫率和出生体重与对照组比较差异也具有统计学意义(P＜0.05),甲硫咪唑治疗组和丙硫氧嘧啶治疗组新生儿出生体重差异均具有统计学意义(P＜0.05).结论 早期采取甲硫咪唑或丙硫氧嘧啶对妊娠期甲状腺功能亢进妇女进行治疗对母婴健康、提高新生儿出生质量均有积极作用,并且甲硫咪唑作用更佳,可作为妊娠期甲状腺功能亢进的首选治疗.     

黄芪甲苷对氧糖剥夺复氧后星形胶质细胞上TNF-α与AQP-4表达的影响

目的:探索黄芪甲苷(astragaloside IV,ASIV)对氧糖剥夺复氧(oxygen glucose deprivation/reperfusion,OGD/R)后星形胶质细胞上肿瘤坏死因子-α(tumor necrosis facror-alpha,TNF-α)与水通道蛋-4(aquaporin-4,AQP-4)表达的影响。方法:选用第二代第1 d的星形胶质细胞。将星形胶质细胞放入缺氧培养箱(1%O_2、94%N2、5%CO_2),分别干预1、2、3、4 h,复氧24 h后用RT-PCR和Western Blot检测AQP-4和TNF-α的表达情况。将星形胶质细胞分为对照组、OGD/R组、OGD/R+0.001μmol/ml ASIV组、OGD/R+0.01μmol/ml ASIV组,用RT-PCR和免疫荧光检测AQP-4和TNF-α的表达情况。结果:RT-PCR和Western Blot结果显示:氧糖剥夺复氧后AQP-4和TNF-α的表达均增加,且AQP-4在OGD3 h时表达达到高峰,TNF-α在OGD1 h时表达达到高峰(P0.05);OGD3h+0.001μmol/ml ASIV组和OGD3 h+0.01μmol/ml ASIV组的AQP-4基因表达水平较OGD3 h组相比均明显降低(P0.05);与OGD3 h组相比,OGD3 h+0.001μmol/ml ASIV组的AQP-4蛋白表达水平明显降低(P0.05);OGD1 h+0.001μmol/ml ASIV组和OGD1 h+0.01μmol/ml ASIV组的TNF-α基因表达水平与OGD1 h组相比均明显降低(P0.05);与OGD1 h组相比,OGD1 h+0.001μmol/ml ASIV组的TNF-α蛋白表达水平明显降低(P0.05)。结论:氧糖剥夺复氧模型可以诱导星形胶质细胞上TNF-α和AQP-4的表达,且TNF-α的表达先于AQP-4;黄芪甲苷可能是通过下调TNF-α的表达来影响AQP-4的表达,进而影响细胞水肿。     

N-乙酰基-丝氨酰-天门冬酰-赖氨酰-脯氨酸对大鼠心脏成纤维细胞胶原蛋白合成及表达的调节作用

目的：探讨N-乙酰基-丝氨酰-天门冬酰-赖氨酰-脯氨酸(AcSDKP)对血小板衍生生长因子(PDGF)诱导的大鼠心脏成纤维细胞胶原合成的调节作用。方法：建立新生大鼠心脏成纤维细胞系；采用~3H-脯氨酸掺入法检测心脏成纤维细胞胶原蛋白的合成。采用Western印迹法检测心脏成纤维细胞Ⅰ、Ⅲ型胶原蛋白的表达。结果：PDGF对心脏成纤维细胞胶原蛋白合成的促进作用与浓度相关,并以10 ng/ml时最强。AcSDKP对PDGF介导的心脏成纤维细胞胶原合成有抑制作用,并且在10~(-9)mol/L时作用最强。结论：AcSDKP对PDGF介导的心脏成纤维细胞胶原合成有明显抑制作用,可能与其抗心脏纤维化的作用相关。     

草药瑞香狼毒丙酮提取物与低剂量卡马西平或丙戊酸镁配伍的抗惊厥研究

目的:探讨草药瑞香狼毒丙酮提取物(AESC)与西药卡马西平(CBZ)、丙戊酸镁(VPM)配伍使用后抗癫痫效果,并与西药单药进行比较。方法:观察AESC和CBZ、VPM不同的配伍方式和剂量,对大鼠癫痫模型、小鼠电休克惊厥模型、小鼠戊四唑惊厥模型和小鼠印防已毒素惊厥模型的作用,并观察AESC对健康自愿受试者CBZ和VPM血药浓度的影响。结果:AESC 500 mg/kg与CBZ 30 mg/kg及VPM 68 mg/kg配伍后对上述三种模型的抗惊厥效应明显优于单用CBZ、VPM组(P<0.01)。结论:采用AESC与小剂量抗惊厥西药CBZ或VPM合理配伍使用可提高抗惊厥效应及减少抗惊厥西药剂量,从而减少西药剂量相关的副作用,具有抗惊厥效应好、抗癎谱广、减少副作用等优点。     

Inhibition by inositoltetrakisphosphates of calcium- and volume-activated Cl– currents in macrovascular endothelial cells

 We have used the whole-cell patch-clamp technique to study the effects of inositol 1,4,5,6-tetrakisphosphate [Ins(1,4,5,6)P ₄], inositol 3,4,5,6-tetrakisphosphate [Ins(3,4,5,6)P ₄] and inositol 1,3,4,5,6-pentacisphosphate [Ins(1,3,4,5,6)P ₅] on volume-activated Cl^– currents (I _Cl,vol) in cultured endothelial cells from bovine pulmonary artery (CPAE cells). Ins(1,4,5,6)P ₄ and Ins(3,4,5,6)P ₄ were applied intracellularly via the patch pipette at concentrations between 10 and 100 μM. Both tetrakisphosphates inhibited the Cl^– current I _Cl,Ca, which was activated by intracellular loading of the cells with 500 nM Ca²⁺ [for inhibition by Ins(1,4,5,6)P ₄: 58% at 10 μM, 75% at 100 μM; for Ins(3,4,5,6)P ₄: 44% at 10 μM, 65% at 100 μM]. Inhibition of I _Cl,Ca occurred without significant changes in its kinetic properties. The amplitude of I _Cl,vol activated by a 13.5 or 27% hypotonic solution at +100 mV was strongly reduced in cells loaded with either tetrakisphosphate, i.e. a 73% reduction for Ins(3,4,5,6)P ₄ and 89% for Ins(1,4,5,6)P ₄ at 100 μM. Both tetrakisphosphates also inhibited a current probably identical to I _Cl,vol which was activated by dialysing the cell with 100 μM guanosine 5′-O-(3-thiotriphosphate) (GTP[γ-S]). Ins(1,3,4,5,6)P ₅ at a concentration of 30 μM did not significantly reduce I _{Cl, vol}. The effects of Ins(3,4,5,6)P ₄ may represent an inhibitory pathway for the I _Cl,Ca and I _Cl,vol in macrovascular endothelium after sustained receptor-mediated activation of phospholipase C. Received: 8 September 1997 / Received after revision and accepted: 31 October 1997     

Somatic and dendritic actions of gamma-aminobutyric acid agonists and uptake blockers in the hippocampus in vivo

In rats under urethane anaesthesia gamma-aminobutyric acid agonists and uptake blockers were microiontophoretically applied in the pyramidal layer of CA1 and in the apical dendrites using a twin set of multibarrelled micropipettes. Thus, the somatic and dendritic field potentials elicited by commissural stimulation were recorded simultaneously and the effects of iontophoretic applications at either site studied. Somatic applications of gamma-aminobutyric acid, isoguvacine or muscimol produced an inhibition of the somatic population spike; this showed rapid fade and was followed by an "off" response i.e. an enhancement of the population spike discharge and the occurrence of a second (and occasionally third) spike. The order of potency with regard to the "off" response was muscimol greater than isoguvacine much greater than gamma-aminobutyric acid. In contrast, the inhibition of the population spike produced by 4,5,6,7-tetrahydroisoxazolo(5,4-C) pyridin 3-OL showed little fade and no prominent "off" response. The fade and "off" response were not associated with significant changes in the dendritic field excitatory postsynaptic potential concommittantly recorded and were exclusively restricted to the immediate vicinity of the pyramidal layer. Ejection of gamma-aminobutyric acid and its agonists in the stratum radiatum produced a reduction of the field excitatory postsynaptic potential and the somatic spike, this effect however showed no fade (even during prolonged applications of high doses) and no "off" response. Somatic applications of the uptake blockers nipecotic acid or guvacine consistently produced: an increase in the effectiveness of the inhibition produced by gamma-aminobutyric acid and its analogues: a decrease in the latency to peak of the inhibition and an increase in the time to recovery; a full blockade of the fade and the "off" response. All of these effects were rapid and fully reversible without significant changes in either the field excitatory postsynaptic potential or the (control) somatic spikes. The more specific glial uptake blocker, 4,5,6,7-tetrahydroisoxazolo(4,5-C) pyridin 3-OL occasionally blocked the "off" response, however it was less potent and also tended to reduce the spike amplitude. Dendritic applications of the uptake blockers reduced the excitatory postsynaptic potential and the somatic spike but failed to produce prominent changes in the action of gamma-aminobutyric acid and its analogues.(ABSTRACT TRUNCATED AT 400 WORDS)     

Human umbilical cord blood cells express neurotrophic factors

Freshly isolated or culture-expanded human umbilical cord blood mononuclear cells (CBMNCs) have been known to express neural phenotypes in vitro and to differentiate into neural cells and improve neurological function recovery after being administrated into rodent models of neurological diseases. However, the mechanism of action remains unclear. The present study observed that CBMNCs expressed higher level mRNAs of several neurotrophic factors than adult peripheral blood mononuclear cells (PBMCs). In addition, a significantly increase in the levels of brain-derived neurotrophic factor (BDNF) and neurotrophin-4/5 (NT4/5) was found in culture supernatants of CBMNCs compared to that of PBMNCs. These findings indicate that CBMNCs express several neurotrophic factors and suggest that the neurotrophic factors secreted by CBMNCs may be responsible for amelioration of central nervous system deficits in animal models after CBMNC administration.     

Why are there so few key mutant clones? The influence of stochastic selection and blocking on affinity maturation in the germinal center

A small number of key somatic mutations lead to high-affinity binding in the anti-hapten immune responses to 2-phenyl-5-oxazolone (phOx) and (4-hydroxy-3-nitrophenyl)acetyl (NP). Affinity maturation models of the germinal center hold that B cells carrying these key mutations are preferentially selected for expansion within the germinal centers. However, additional factors are required to account for some quantitative aspects of affinity maturation in vivo. Radmacher et al. have shown that key mutants are observed in vivo significantly less frequently than expected by these models. To account for this finding, they propose that selection is a stochastic process where key mutants may be overlooked by positive selection or recruited out of the germinal center. While acknowledging that a minimal amount of stochastic selection is probably unavoidable in the germinal center, we instead propose a structural explanation for this key mutant discrepancy. This model is based on the existence of a large number of blocking mutations whose presence can prevent the ability of key mutations to confer high-affinity binding. Using mathematical modeling and computer simulation, we show that in addition to reconciling the key mutant discrepancy, the blocking model accounts for other aspects of experimental data that are not predicted by the stochastic selection model. In particular, the blocking model is consistent with the observation that key mutants generally exhibit a higher number of mutations per sequence in the phOx response, but a lower number in the NP response.     

Endogenous cannabinoids as an aversive or counter-rewarding system in the rat

Human use of marijuana (Cannabis sativa) is widely assumed to have rewarding properties, a notion supported by its widespread recreational use. However, no study has clearly demonstrated such effects in animal models. The purpose of this study was to test for the presumed rewarding effect of cannabinoids using a conditioned place preference paradigm. The results showed that animals failed to develop place conditioning at a low dose (1.5 mg/kg) and developed a place aversion at a high dose (15 mg/kg) of the active principle in marijuana, Δ⁹-tetrahydrocannabinol (Δ⁹-THC), a finding consistent with most previous studies. Moreover, the administration of the cannabinoid antagonist SR141716A induced a conditioned place preference at both a low (0.5 mg/kg) and a high (5 mg/kg) dose. In summary, cannabinoid antagonism produced place preference while cannabinoid agonism induced place aversion. These results suggest that endogenous cannabinoids serve normally to suppress reward or to induce aversion.     

Polymorphism C in the serotonin transporter gene (SLC6A4) in questionable dementia and Alzheimer's disease

The promoter region of the serotonin transporter gene (SLC6A4) shows a 22-bp tandem repeat polymorphism, indicated as polymorphism C, that has been associated to depression, obsessive-compulsive disorder, memory impairment, and anxiety. Less clear are data regarding its association with Alzheimer's disease (AD). No data were reported regarding its association with questionable dementia (QD). In this study we investigate for polymorphism C in the SLC6A4 gene 302 elderly subjects with a clinical diagnosis of AD (n = 105), QD (n = 88) and no cognitive impairment (n = 114) attending a geriatric ward. A community-dwelling sample of 390 healthy subjects was also included in the analysis. A significant higher prevalence of the C16/C16 genotype in AD than in QD was observed (37.14% vs. 3%; p = 0.041, OR 2.001, 95%CI 1.018–4.024), while no differences in the C16/C14 and C14/C14 genotypes as well as in the estimated allele frequencies were found. No further differences among the three groups of subjects were found, also when they were compared with the community-dwelling sample. These findings suggest that SLC6A4 gene variation may have only a minor role, if any, in AD or QD.     

人白细胞介素4的原核表达、复性、纯化及生物学活性鉴定

用PCR方法从pORF-hIL4质粒中扩增重组人白细胞介素4(hIL-4)的基因,构建PQE60原核表达载体并诱导其目的蛋白的表达。对表达的目的蛋白的可溶性进行鉴定,发现hIL-4基因表达产物在大肠杆菌中主要以不溶性包涵体形式存在,经过超声波破细菌、包涵体提取、洗涤处理后,用5mol/L盐酸胍变性溶解包涵体沉淀,上清稀释复性后透析,再经镍亲和层析进行纯化。纯化后的hIL-4进行TF-1细胞体外增生实验检测其生物学活性后,可用于人外周血树突状细胞的体外诱导培养。     

Stringent regulation of complement lectin pathway C3/C5 convertase by C4b-binding protein (C4BP)

The complement lectin pathway, an essential component of the innate immune system, is geared for rapid recognition of infections as each C4b deposited via this pathway is capable of forming a C3/C5 convertase. In the present study, role of C4b-binding protein (C4BP) in regulating the lectin pathway C3/C5 convertase assembled on zymosan and sheep erythrocytes coated with mannan (E_Man) was examined. While the C4BP concentration for inhibiting 50% (IC₅₀) formation of surface-bound C3 convertase on the two surfaces was similar to that obtained for the soluble C3 convertase (1.05 nM), 3- and 41-fold more was required to inhibit assembly of the C5 convertase on zymosan (2.81 nM) and E_Man (42.66 nM). No difference in binding interactions between C4BP and surface-bound C4b alone or in complex with C3b was observed. Increasing the C4b density on zymosan (14,000–431,000 C4b/Zym) increased the number of C4b bound per C4BP from 2.87 to 8.23 indicating that at high C4b density all seven α-chains of C4BP are engaged in C4b-binding. In contrast, the number of C4b bound per C4BP remained constant (3.79 ± 0.60) when the C4b density on E_Man was increased. The data also show that C4BP regulates assembly and decay of the lectin pathway C3/C5 convertase more stringently than the classical pathway C3/C5 convertase because of a 7- to 13-fold greater affinity for C4b deposited via the lectin pathway than the classical pathway. C4BP thus regulates efficiently the four times greater potential of the lectin pathway than the classical pathway in generating the C3/C5 convertase and hence production of pro-inflammatory products, which are required to fight infections but occasionally cause pathological inflammatory reactions.     

细胞膜电位的动态监测及其在银杏内酯研究中的应用

建立了一种简便、快速的膜电位的测量方法.采用亲脂性阴离子荧光探针DiBAC4(3)标记大鼠脑神经元细胞,以倒置荧光显微镜观察并记录细胞膜电位的变化.用所建方法研究了银杏总内酯,及银杏内酯A、银杏内酯B、银杏内酯C和白果内酯对大鼠脑神经元细胞膜电位的影响.结果显示,加入银杏总内酯及各种银杏内酯后细胞出现去极化,膜电位迅速改变,随后回复至正常水平,银杏总内酯对细胞膜电位的影响大于各单体,其中以银杏内酯B的作用为主.