在基质材料中生长的许旺细胞：存活、黏附、三维生长和迁移特性

目的:将许旺细胞与细胞外基质凝胶、聚乳酸-羟基乙酸共聚物纤维丝复合培养,观察许旺细胞的存活、黏附、三维生长和迁移等生物学行为。方法:实验于2005-02/2006-03在四川大学完成。①实验材料:3～6月龄SD大鼠40只。16～24周流产胎儿由四川大学华西二医院计划生育科提供,产妇及其家属均签署知情同意书,实验经医学伦理委员会批准。聚乳酸-羟基乙酸共聚物(中国科学院成都分院化学所提供);细胞外基质凝胶(Sigma)。②实验方法:将聚乳酸-羟基乙酸共聚物溶解,旋转抽丝法制成直径为20～40μm的聚乳酸-羟基乙酸共聚物纤维丝。无菌条件下取胎儿坐骨神经,去除神经外膜,胰酶消化 差速贴壁法去除成纤维细胞,达80%融合时行BrdU标记。③实验评估:将许旺细胞离心制成0.1～0.2mm3的微粒,接种在细胞外基质凝胶中,观察许旺细胞在凝胶中的存活、生长和移行。将许旺细胞制成1×1010L-1的30%细胞外基质凝胶后,分别滴加在经过胶原、细胞外基质凝胶预处理的聚乳酸-羟基乙酸共聚物纤维丝的一端,观察许旺细胞在纤维丝上的黏附、生长和迁移。将BrdU标记的许旺细胞复合细胞外基质凝胶后,置入聚乳酸纤维管用以修复大鼠坐骨神经缺损,术后3,6周取材,BrdU免疫组化染色观察许旺细胞的存活情况。结果:①许旺细胞在无血清状态下能在细胞外基质凝胶中存活,并分裂、增殖,相互移行形成类似Bungner带状的许旺细胞柱状结构。②许旺细胞能贴附在聚乳酸-羟基乙酸共聚物纤维丝上生长并沿纤维丝移行,形成多层排列的类似Bungner带状的许旺细胞柱,细胞外基质凝胶能显著增加贴附和移行细胞数量,而胶原作用不显著。③许旺细胞和细胞外基质凝胶复合移植,6周后BrdU阳性细胞数明显低于第3周(t=3.71,P<0.01),成活细胞能在细胞外基质凝胶中移行。结论:许旺细胞与细胞外基质凝胶、聚乳酸-羟基乙酸共聚物纤维丝等生物材料复合培养时,能存活、分裂、增殖,相互移行形成类似Bungner带状的细胞柱,并可贴附在纤维丝上生长迁移,该生物学行为对神经组织工程具有重要作用。     

GABA在摄食和味觉机制中的作用

γ-氨基丁酸(γ-aminobutyric acid,GABA)是哺乳动物中广泛分布的一种抑制性神经递质,GABA及其受体在下丘脑、杏仁核、孤束核等摄食和味觉中枢均有分布．GABA具有A、B和C三种受体,其中A和B受体参与对摄食行为和味觉感知．在不同脑区应用GABA选择性受体拮抗剂可不同程度的促进或抑制摄食,并对味觉的喜好和厌恶发生改变．另外,GABA与调节摄食和味觉的有关物质具有相互作用,他们共同参与摄食和味觉的调控．本文就GABA在摄食和味觉感受与调制中的研究进展进行了回顾．     

Enzyme histochemistry and immunohistochemistry on biopsy specimens of pathologic human bone marrow

We have systematically investigated a variety of fixation and plastic embedding procedures and arrived at a method that allows processing of approximately 2-micron sections of bone marrow biopsies for examination by light microscopy. More importantly, this method permits the use of enzyme histochemical and immunohistochemical procedures that are rapidly becoming mandatory in the diagnosis of hematologic malignancies. Over 200 full-length bone marrow biopsy specimens were fixed in a mixture of paraformaldehyde, glutaraldehyde, and acrolein, dehydrated in acetone, and embedded in a mixture of methyl and glycolmethacrylate. All procedures were carried out at 4 degrees C. Decalcification was unnecessary. Sections 2-micron thick were cut and incubated for peroxidase, naphthol AS-D chloroacetate esterase, alpha- naphthyl butyrate esterase, acid phosphatase (with and without tartrate), or alkaline phosphatase and then examined by light microscopy. Specimens could be prepared for examination within 48 hr. This approach, which provides definitive markers for various hematopoietic cell lines in intact tissues, is invaluable when aspirated material is unavailable. It is also useful in the analysis of focal lesions of bone marrow due to inflammation or neoplasia and shows potential as an investigative tool. For example, we have discovered that early myelofibrosis is accompanied by a marked increase in the number of alkaline-phosphatase-positive reticulum cells.     

Identification and quantitation of protein S in human platelets

Gel filtered human platelets contaminated with less than 0.02% of plasma protein S contained 490 ng of protein S antigen per 3 X 10(8) platelets, equivalent to 2.5% of protein S in whole blood. Three patients with heterozygous plasma protein S deficiency, a congenital disorder associated with venous thrombotic disease, had platelet protein S antigen levels that were 40% of the mean platelet level in ten normal volunteers. In immunoblotting analysis, platelet protein S was indistinguishable from plasma protein S. Thrombin stimulation of platelets caused release of 63% of total protein S antigen and this release was abolished when platelets were preincubated with metabolic inhibitors. Thrombin effected limited proteolysis of platelet protein S and this reaction was inhibited by calcium ions. Immunofluorescent staining of platelets using protein S antibodies demonstrated that protein S colocalized with fibrinogen, an established alpha-granule protein. Thus, human platelets contain protein S in alpha granules that can be released by thrombin stimulation. The released protein S may bind to stimulated platelets and thereby promote and localize the anticoagulant activity of activated protein C on the platelet surface.     

乙肝病毒疫苗的类型及其免疫原性和安全性

乙型肝炎(HB)病毒(HBV)疫苗主要包括血源疫苗、基因工程酵母疫苗、地鼠及仓鼠卵细胞(CHO)疫苗．血源疫苗已被基因重组HBV(rHBV)疫苗所代替,后者现已发展到第3代及第4代,如含Pre-S的CHO疫苗及添加佐剂如寡核苷酸、3抗原(含S,Pre-S1和Pre-S2)的Hepacare疫苗和3’-单磷酸脂A(AS04)疫苗等．近年来又研制成功了肺炎球菌多糖苷蛋白结合rHBV疫苗及可口服和涂抹的DNA疫苗等．目前所应用的rHBV疫苗均具有很好的免疫原性已得到世界公认和肯定,且国内外无明显差别．不良反应普通rHBV疫苗小于2．5％,主要为针刺部位痛、红、肿、胀、痒,一般轻微,日余即消．小于0．5％的人有发热、嗜睡、食欲下降等反应,多见于HB-AS04疫苗,无需处理.     

Donor immunization with Haemophilus influenzae type b (HIB)-conjugate vaccine in allogeneic bone marrow transplantation

Bone marrow transplant patients are at increased risk for infections with polysaccharide encapsulated organisms and respond poorly to polysaccharide vaccines. We evaluated the effect of donor immunization with Haemophilus influenzae type b (HIB) polysaccharide-conjugate vaccine on recipient antibody responses following allogeneic bone marrow transplantation. Thirty-two allogeneic transplant patients and their donors were immunized before transplantation with HIB-conjugate, tetanus toxoid and 23-valent pneumococcal vaccines. Following transplantation, patients received HIB-conjugate and tetanus toxoid vaccines at 3, 6, 12, and 24 months and 23-valent pneumococcal vaccine at 12 and 24 months. Thirty-three patients with unimmunized donors were immunized following transplantation in an identical manner. Patients whose donors were immunized had significantly higher total anti-HIB antibody concentrations at 3 months (P = .0001), 6 months (P = .0001), 12 months (P = .0001), and 24 months (P = .002) after transplant compared with patients whose donors were unimmunized. Higher antitetanus toxoid antibody concentrations were also noted in patients with immunized donors, whereas donor immunization with pneumococcal vaccine had no effect on antibody concentrations following transplantation. Donor immunization with HIB-conjugate vaccine resulted in higher antibody concentrations in patients as early as 3 months after allogeneic transplantation and may be an effective strategy to prevent HIB infections.     

慢性心力衰竭中胃肠系统变化的意义

慢性心力衰竭(chronic hean failure,CHF)是多脏器受累的临床综合征,其中胃肠道系统的变化逐渐引起人们关注．心衰发生后,胃肠道低灌注,胃肠黏膜缺血缺氧,肠道屏障功能障碍, 从而发生肠道细菌移位和肠源性内毒素血症．内毒素激活体内细胞因子和炎性介质的释放, 此过程可进一步引起肠道屏障功能障碍和心肌细胞损害,从而形成恶性循环,引起心衰进展．国内外有研究发现,对心衰胃肠道发生的改变进行干预与治疗,对改善心衰症状,阻止心衰进展具有良好效果．     

HTLV-III infection after bone marrow transplantation

We prospectively documented the development of a fatal, secondarily acquired severe immunodeficiency in a 19-year-old man who underwent uncomplicated bone marrow transplantation. He had no graft v host disease (GVHD) and had normal recovery of his immune system as determined by lymphocyte phenotyping, mitogenic responses of his peripheral blood lymphocytes, and his ability to secrete immunoglobulin. This alteration in immunity was associated with the acquisition of antibody to HTLV-III. His only risk factor for the development of HTLV-III infection was the transfusions he had received during the transplant and recovery period. Two of his 54 transfusions were from an asymptomatic individual at high risk for acquired immunodeficiency syndrome (AIDS), who was subsequently found to be seropositive for anti-HTLV-III and from whom HTLV-III was isolated. The loss of immunocompetence in patients without chronic GVHD disease is unusual, and our data support the view that this patient's immunodeficiency was due to HTLV-III. When bone marrow transplant recipients without chronic GVHD develop late opportunistic infections, consideration should be given to transfusion-associated AIDS.