国内首起本地感染甲型H1N1流感疫情的流行病学分析

目的 分析周内首起甲型H1N1流感输入性传染源引发本地二代病例疫情,探讨发病规律和流行特征.方法 设计统一调查表,采用面对面病例个案调查和现场调查,以指示病例为起点进行追踪,描述传播过程及各因素与发病之间的关系,分析疫情的流行病学特征.结果 发现指示病例后,密切接触者中有2人出现发热和上呼吸道症状且咽拭子甲型H1N1流感病毒核酸检测阳性,被确诊为国内首起本地感染甲型H1N1流感病例.2名密切接触者未采取任何防护措施与指爪病例多次近距离接触,且现场通风不良;发病潜伏期37～57 h,临床表现均较指示病例轻.经采取严格防疫措施,未见新发病例.结论 此次事件为由输人性传染源引起的本地感染疫情,无防护近距离空气及飞沫传播为主要传播方式,空气流通不良的密闭空间是高危场所.     

眼用环孢霉素A缓释超微粒的制备及眼内分布研究

目的探讨壳聚糖-胆固醇双亲性聚合物包载环孢霉素A的缓释性及超微粒制备及眼内分布.方法壳聚糖-胆固醇双亲性聚合物与环孢霉素A共溶于溶剂中,对水透析形成超微载药微粒,37℃条件下测试超微粒体外释放状态.以放射性99锝标记壳聚糖超微粒,制成滴眼剂,以SPECT测试超微粒在兔眼中的滞留时间.结果壳聚糖载药超微粒可在6小时内缓释环孢霉素A,超微粒在给药后4小时在眼表具有良好的滞留性.结论以壳聚糖双亲性聚合物包载环孢霉素A对干眼症的治疗具有潜在的应用价值.     

正交试验优化超高压提取人参中人参皂苷的工艺研究

目的　研究超高压提取人参中人参皂苷的最佳工艺。方法　采用超高压技术常温提取,正交试验优化,分光光度法检测人参总皂苷的含量。结果　超高压提取人参皂苷的最佳提取工艺参数为:提取溶剂为5 0 %乙醇,固液比为1∶75 ,提取压力为5 0 0 MPa,提取时间2 m in,人参皂苷的得率高达7.76 %。结论　超高压提取工艺具有提取效率高、时间短、能耗低、杂质含量少等优点。     

Inhibition of embryonic development by microcystin-LR in zebrafish, Danio rerio.

Microcystin-LR (MC-LR), a cyanobacterial toxin, is a potent inhibitor of protein phosphatase 1 (PP1) and protein phosphatase 2A (PP2A). PP1 and PP2A are critical regulators in embryonic development. However, the effects of MC-LR in embryonic development have been controversial. MC-LR has been demonstrated to be highly toxic in medaka, but not in zebrafish or rabbit embryos. The causes of difference may be due to membrane impermeability that impaired the delivery of MC-LR into cytoplasm of zebrafish and rabbit embryos. Therefore, we microinjected MC-LR directly into developing zebrafish embryos and investigated the effects of MC-LR on embryonic development. We demonstrated that MC-LR induced the lethality of zebrafish embryos in a dose- and time-dependent manner. MC-LR also induced the loss of blastomere coherence via the interference of beta-catenin and cadherins distributions. Furthermore, the MC-LR treated fry revealed various developmental defects. These results suggested that MC-LR might affect the phosphorylation equilibrium of signaling molecules, including beta-catenin and cadherins, required early in zebrafish embryonic development.     

Salinity effect on growth and toxin production of four tropical Alexandrium species (Dinophyceae).

Four tropical PSP toxins-producing dinoflagellates, Alexandrium minutum, Alexandrium tamiyavanichii, Alexandrium tamarense and Alexandrium peruvianum from Malaysian waters were studied to investigate the influences of salinity on growth and toxin production. Experiments were conducted on constant temperature 25 degrees C, 140 microE mol m(-2) s(-1) and under 14:10 light:dark photo-cycle with salinity ranged from 2 to 30 psu. The PSP-toxin congeners, GTX 1-6, STX, dcSTX, NEO and C1-C2 were analysed by high performance liquid chromatography. Salinity tolerance of the four species in decreasing order is A. minutum>A. peruvianum>A. tamarense>A. tamiyavanichii. Specific growth rates and maximum densities varied among these species with A. minutum recorded as the highest, 0.5 day(-1) and 6 x 10(4) cells L(-1). Toxin content decreased with elevated salinities in A. minutum, the highest toxin content was about 12 fmole cell(-1) at 5 psu. In A. tamiyavanichii, toxin content peaked at optimal growth salinity (20 and 25 psu). Toxin content of A. tamarense, somehow peaked at sub-optimal growth salinity (15 and 30 psu). Results of this study implied that salinity fluctuation not only influenced the growth physiology but also toxin production of these species.     

土槿皮乙酸体外诱导A375-S2细胞凋亡

目的 :研究土槿皮乙酸 (pseudolaricacidB)诱导A375 S2细胞凋亡的作用 ,探讨其抗癌作用机制。方法 :采用噻唑蓝 (MTT)法、形态学观察、DNA凝胶电泳及Westernblot检测法。结果 :土槿皮乙酸可剂量 时间依赖性的诱导A375 S2细胞凋亡 ,5 μmol·L^-1土槿皮乙酸处理 36h的细胞 ,Hoechst 332 5 8荧光染色后有明显的凋亡小体出现 ;凝胶电泳法显示有明显的DNAladder出现。细胞内抑制凋亡蛋白Bcl 2 ,Bcl xL和caspase激活的DNA酶抑制物(ICAD)表达量时间依赖性地减少 ,而促凋亡蛋白Bax表达量增加。结论 :土槿皮乙酸对A375 S2细胞的杀伤作用主要通过诱导细胞凋亡 ,降低Bcl 2 ,Bcl xL和ICAD蛋白的表达 ,增加Bax蛋白表达为其诱发A375 S2细胞凋亡的机制之一。     

川芎内酯A预处理对大鼠离体心脏缺血再灌注所致血管内皮细胞损伤的保护作用

目的:观察川芎内酯A预处理对大鼠离体心脏缺血再灌注所致血管内皮细胞损伤的保护作用。方法:采用Langendorff离体心脏灌流方法,在恒温恒压条件下,以0.5mL.min^-1的灌流速度给药,剂量分别为0.05,0.025,0.0125g.L^-1与K-H灌流液同时灌流心脏10min;全心停灌30min,再灌60min。结果:川芎内酯A预处理能提高大鼠离体心脏停灌再灌期的冠脉流量;降低冠脉流出液中IL-1β浓度和TXB₂/6-Keto-PGF_1α的比值;室性心动过速(VT)和心室颤动(VF)的发生率降低,VT,VF持续时间缩短;心肌匀浆液乳酸脱氢酶、丙二醛的含量降低,超氧化物歧化酶活性提高。结论:川芎内酯A预处理对大鼠离体心脏停灌再灌注损伤所致的血管内皮细胞损伤可能具有保护作用。     

Brainstem catecholaminergic neurons activated by hypoxemia express GR and are coordinately activated with fetal sheep hypothalamic paraventricular CRH neurons

In late gestation, challenges to fetal homeostasis are accompanied by increases in adrenocorticotropin (ACTH) concentrations in fetal peripheral plasma and Fos (c-fos protein) activation in corticotropin-releasing hormone (CRH) neurons of the fetal hypothalamic paraventricular nucleus (PVN). In adults, ventrolateral brainstem catecholaminergic (CA) neurons (A1/C1, A2/C2) project to the parvocellular neurons of the PVN, possess glucocorticoid receptors (GR) and are Fos activated in parallel with CRH neurons of the PVN during hypoxia. Such observations suggest a role for the aforementioned medullary neurons in the function of the hypothalamo-pituitary-adrenal axis. The present study utilized late gestation fetal sheep, stereotaxic methodology and retrograde axon tracing and immunocytochemical techniques to investigate the relationship between activation of fetal brainstem CA neurons and activation of fetal PVN CRH immunopositive neurons in response to hypoxemia. Results indicated that: (1) the largest brainstem CA projection to PVN CRH neurons is from A1/C1 neurons, (2) brainstem neurons exhibit GR immunostaining and (3) brainstem CA neurons show a strong correlation (A1/C1 - r(2)=0.894, P<0.005; A2/C2 - r(2)=0. 848; P<0.002) of Fos activation with Fos activation in PVN CRH cells. We conclude that in late gestation the brainstem A1/C1 and A2/C2 areas are in position to influence the function of the hypothalamo-pituitary-adrenal axis during hypoxemic challenges to homeostasis in a fashion similar to that which has been demonstrated in the adult rat.     

Postnatal development of NR1, NR2A and NR2B immunoreactivity in the visual cortex of the rat

N-Methyl-D-aspartate receptors (NMDARs) are critically involved in some types of synaptic plasticity. The NMDAR subunits NR1, NR2A and NR2B are developmentally regulated, and it has been proposed that developmental changes in their expression may underlie developmental changes in cortical plasticity. Age-dependent change in cortical plasticity is most commonly measured by the monocular deprivation effect, which occurs during a critical period between P22 and P50 in the rat. Although the development of NMDAR subunits has been studied from birth through the fourth postnatal week, there is only meager information from older ages when visual plasticity ends. We hypothesized that there will be significant age-dependent change in expression of NR1, NR2A or NR2B between P22, when the cortex is plastic, and P90, when it is not. We applied specific antibodies recognizing NR1, NR2A and NR2B to the primary visual cortex at P14, P22, P30, P45 and P90. We found age-dependent changes in NR1-IR that were negatively correlated with changes in NR2A-IR; these subunits are not regulated in unison. In contrast, NR2A-IR and NR2B-IR were positively correlated. NR2A-IR and NR2B-IR both passed through a developmental minimum around P45, then recovered to approximately their P22 level. NR1-IR passed through a maximum at P45. There were no significant differences between P22 and P90. These results do not support the simple hypothesis that the loss of plasticity corresponds to a simple transition from juvenile levels of NMDAR subunit proteins to new adult levels. On the other hand, the results do confirm the hypothesis that there are significant changes in processing of NMDAR proteins during the time that plasticity is lost. How these changes of IR relate to synaptic transmission and plasticity needs to be clarified.     

乙型肝炎病毒前C区A83突变检测及临床研究

目的　应用扩增抗拒突变系统 (AmplificationrefractorymutationssystemARMS)检测乙型肝炎病毒前C区A83突变 ,同时应用基因测序法评价其可行性 ,并探讨乙型肝炎病毒前C区A83突变与患者临床病情及血清中HBeAg表达的关系。　方法　采用ARMS对 13 9例乙型肝炎病毒感染者血清中HBVDNA前C区nt1896位点进行检测 ,并对其中 62例标本采用巢式PCR扩增HBVDNA前C区基因片段后直接测序。　结果　 62例标本中 ,ARMS检测出A83突变3 5例 ,基因测序法检测出A83突变 41例 ,A83突变例数差异无显著性 ( χ2 =1.2 3 ,P >0 .0 5 ) ;在ARMS检测的 13 9例标本中 ,HBeAg阳性标本 5 7例 ,有 5例A83突变 ,占 8.8% ,HBeAg阴性的 82例标本中有 5 6例A83突变 ,占 68.3 % ( χ2 =48.4,P <0 .0 1) ;2 2例急性肝炎 (AH )患者未检测到A83位点突变 ,79例慢性肝炎患者 (CH )有 3 1例A83位点突变( 3 9.2 % ) ,2 9例肝硬化患者 (HLC)中有 2 1例A83位点突变 ( 72 .4% ) ,9例肝癌患者 (HCC)均有A83位点突变 ( 10 0 % )。　结论　HBeAg阴性患者病毒前C区A83突变率明显高于HBeAg阳性患者 ;前C区A83突变与患者感染乙型肝炎病毒后的慢性化有关 ;ARMS检测方法简单、快速、结果可靠 ,可以满足临床对乙肝病毒前C区A83突变分析的需要。