Modelling HA protein-mediated interaction between an influenza virus and a healthy cell: pre-fusion membrane deformation.

We present a mathematical model for pre-fusion interaction between an influenza virus and a healthy cell. Our model describes the role played by hemagglutinin (HA) protein clusters in bringing the viral membrane into close contact with the host cell membrane as a first step of the fusion process between the two membranes. The viral membrane is modelled as a lipid bilayer with bending rigidity. Using the calculus of variations, we compute the deformation of the viral membrane under the influence of HA protein clusters. Our numerical results support the hypothesis of dimple formation in the fusion site proposed in the literature. The asymmetric nature of the protein molecules due to various reasons such as tilting is the primary cause for the dimple formation. We discuss the effects of spontaneous curvature, the protein cluster radius, fusion-site size and the bending moment exerted by the protein cluster. We also examine the effects of membrane tension and the presence of a host cell on the dimple shape. Our results support previous experimental observations.     

重度烫伤小鼠血清及去补体后血清诱导巨噬细胞凋亡作用的体外实验研究

目的　探讨重度烫伤小鼠血清及去补体血清在体外诱导腹腔巨噬细胞 (pMФs)凋亡及其机制。方法　采用小鼠 30 %TBSAⅢ度烫伤模型 ,分为正常对照组、烫伤组、去补体烫伤组 ,检测各组伤后 6h血清对体外培养的pMФs分泌超氧阴离子 (O2- )和一氧化氮 (NO)产量的影响 ,碘化丙锭 (PI)染色流式细胞术及凋亡电泳试验测定pMФs的凋亡情况。结果　与正常对照测值比较 ,烫伤血清诱导pMФs分泌较多的O2- 和NO ,去补体后烫伤血清诱导O2- 和NO的分泌量显著降低。烫伤血清诱导pMФs凋亡明显增加 ,去补体后烫伤血清和活性氧阻断剂PDTC及NO阻断剂AG能阻断绝大部分pMФs的凋亡。结论　重度烫伤小鼠血清补体能在体外诱导pMФs凋亡 ,O2- 和NO等炎性介质在其中发挥了重要作用     

人胚胎干细胞系HUES4的培养和染色体核型分析

目的建立人胚胎干细胞无动物源性饲养层培养方法,同时对长时间体外培养的人胚胎干细胞核型变化进行分析。方法人胚胎干细胞系HUES4细胞分别培养于小鼠胚胎成纤维细胞和人包皮成纤维细胞饲养层,并对其干细胞特性进行鉴定;在培养传代过程中,收获P27、P34、P41和P44细胞进行染色体核型分析,P27细胞还进行DNA短串联重复序列多态性分析。结果生长于人包皮成纤维细胞饲养层的HUES4细胞碱性磷酸酶染色以及SSEA-4、TRA-1-60和TRA-1-81抗原阳性,SSEA-1抗原阴性。所检测的4代细胞中均见46,XY/46,XY,t（9;15）（q22;q26）核型嵌合现象,且异常核型百分比随传代次数增加有上升的趋势。结论培养人胚胎干细胞的饲养层细胞可由无动物源性的饲养层细胞替代;长期体外培养有增加细胞染色体核型异常的风险。     

骨髓基质细胞和壳聚糖/明胶共混材料生物相容性研究

目的:研究壳聚糖/明胶共混材料对离体培养的骨髓基质细胞粘附及增殖的影响,寻找骨髓基质细胞新的载体材料。方法:取2周龄幼兔的长骨采集骨髓,培养骨髓基质细胞,体外扩增1周后,种植于纯壳聚糖和壳聚糖/明胶共混材料的表面。在倒置光学显微镜、扫描电镜的辅助下,观察细胞的粘附和生长情况,种植7d后用透射电镜观察细胞功能状况,用MTT方法检测种植后2d、4d、6d、8d细胞的增殖情况。结果:壳聚糖/明胶共混材料和纯壳聚糖能促进骨髓基质细胞在材料表面粘附并保持其在机体内的形态。壳聚糖/明胶共混材料表面的骨髓基质细胞功能活跃。在材料表面和培养板表面培养的骨髓基质细胞均能持续增殖,而壳聚糖/明胶共混材料能显著促进骨髓基质细胞的增殖(P<0.01)。结论:壳聚糖/明胶共混材料保持了壳聚糖的某些生物活性,同时由于加入明胶,能促进骨髓基质细胞的增殖,可作为骨髓基质细胞的载体应用于组织工程。     

老年与中青年癌症病人心理健康状况比较研究

癌症是一种心身疾病 ,心理社会因素在癌症的发生、发展及预后中均起着重要作用。反过来 ,癌症对病人来说又是一种恶性刺激 ,会给病人带来沉重的心理负担 ,影响疾病的康复和生活质量 ,并可加速癌症的恶性进展 ,造成不良后果。有研究表明 ,老年与中青年癌症病人因社会地位、社会经验及社会责任的不同而各具特点[1] 。了解不同年龄癌症病人的心理状况 ,并采取相应的处理策略 ,对癌症的治疗和康复具有积极作用。我们对 1999年 7月～ 2 0 0 0年 8月收治的 12 6例老年和 96例中青年癌症病人的心理健康状况进行了对比分析 ,结果总结如下。1　材料和…     

成年大鼠基底前脑隔-斜角带复合体的巢蛋白免疫阳性神经元至海马的纤维投射

目的 观察大鼠基底前脑巢蛋白(nestin)免疫阳性神经元的纤维投射。方法 先用荧光素逆行追踪法显示基底前脑内投射至海马的荧光素标记神经元，观察摄片后再进行nestin免疫组织化学染色。对比荧光照片和免疫组织化学染色照片，辨认荧光素和nestin双标神经元。结果 在基底前脑注射侧的内侧隔核(MS)和斜角带核的垂直支(vDB)和水平支(hDB)均存在荧光素标记细胞，其中一部分为nestin免疫阳性。在MS、vDB和hDB，双标细胞占逆行标记细胞的比例分别为21．3％、25％和20．6％；占nestin阳性细胞的比例分别为26．6％、15．7％和16．3％。结论 大鼠基底前脑的nestin免疫阳性神经元发出神经纤维向海马投射。提示在基底前脑有一个平行于隔-海马胆碱能投射和GABA能投射的第3条通路。     

溶酶体在实验性心肌肥大过程中的作用

本实验用大鼠主动脉结扎的心肌肥大模型,结合电镜酶细胞化学技术,观察心肌肥大发展过程中溶酶体的变化。结果表明:心肌肥大发展时,溶酶体参与心肌细胞改建;到心肌肥大后期,出现大量自噬现象,造成心肌不可逆损伤。     

多种金属离子与单宁酸反应媒染微血管的对比研究

目的　镜下观察单宁酸与金属盐溶液中Ca2 + 、Au+ 、Ag+ 、Pb2 + 、Cu2 + 、Al3 + 、U6+ 、K+ 联用显示大脑微血管的效果。方法　用单宁酸媒染固定液灌流大鼠 ,取脑切片 ,入氯化钙、氯化金、硝酸银、硝酸铅、硫酸铜、硫酸铝钾、醋酸双氧铀、高锰酸钾和重铬酸钾等溶液中呈色。结果　单宁酸与Ca2 + 、Cu2 + 、Ag+ 、Al3 + 结合显示血管清晰 ,与Au+ 、U6+ 、Pb2 + 、K+ 联用媒染血管效果欠佳。结论　含Ca2 + 、Cu2 + 、Ag+ 、Al3 + 的金属盐类可替代氯化铁媒染微血管 ,氯化金、醋酸双氧铀、硝酸铅、重铬酸钾和高锰酸钾不宜与单宁酸联用来显示血管     

Concentrations of endometrial protein PP 14 and CA-125 in uterine flushings performed in natural and stimulated cycles

BACKGROUND: Impaired implantation in assisted reproduction cycles with high serum estradiol (E(2)) concentrations may be attributed to abnormal endometrial development. This study compared concentrations of endometrial proteins in uterine flushings of infertile patients between natural and stimulated cycles. METHODS: Patients received a standard regimen of ovarian stimulation. Seven days after the LH surge in natural cycles or the hCG injection in stimulated cycles, uterine flushings were performed by slowly injecting and aspirating normal saline through a paediatric Foley catheter. Natural cycles were considered as group A whereas stimulated cycles with serum E(2) <20 000 pmol/l and serum E(2) >20 000 pmol/l were classified as groups B and C respectively. PP 14 and CA-125 in uterine flushings were measured and expressed per total protein content. RESULTS: Concentrations of the total protein, PP 14 and CA-125 in the uterine flushings were similar among the three groups. PP 14 per total protein in the uterine flushings was significantly correlated with serum E(2) on the day of hCG (r = 0.459; P = 0.009) in natural cycles only but not in stimulated cycles. CONCLUSION: There was no significant difference between natural and stimulated cycles in concentrations of PP 14 and CA-125 in uterine flushings performed in the mid-luteal phase.     

The effectors of killer activity induced by interferon-alpha and gamma in peripheral blood mononuclear cells

The nature of effectors of interferon (IFN)-alpha or IFN-gamma-induced killer cell activity remains unclear. The aim of this study was to examine killer cell activity induced by IFN-alpha alone, IFN-gamma alone or a combination of both in patients with renal cell carcinoma (RCC) and to determine the phenotypic patterns of these effectors. The study group included 14 patients (12 men and 2 women, median age 64 years, range 36-77) with confirmed RCC. Peripheral blood mononuclear cells (PBMC) from RCC patients or normal volunteers were cultured with IFN-alpha alone, IFN-gamma alone or a combination of both. Cytotoxic activity was assayed against ACHN cells. Subpopulations of effector cells in IFN-induced killer cell activity were characterized by cell sorting. The most effective type of IFN and the optimal concentration of IFN necessary to induce the maximal killer cell activity varied among RCC patients. The killer activity induced by a combination of IFN-alpha and IFN-gamma was significantly greater than that induced by IFN-alpha or IFN-gamma alone. The greatly increased killer activity induced by IFN-alpha and IFN-gamma was seen in the subpopulations CD3(-) CD16(+), CD3(-) CD56(+) and subpopulation CD3(+)CD4(-), CD3(-)CD16(+), CD3(-)CD56(+), CD57(+)CD16(-), respectively. An optimal type of IFN and optimal concentration of IFN seem to increase the effective rate of treatment of RCC. In addition, the role of IFN-alpha seems to be different from that of IFN-gamma in host defense against RCC. A combination treatment with IFN-alpha and IFN-gamma seems to be suitable to increase the effective rate if we could reduce the side effects of IFNs.