p38丝裂原活化蛋白激酶在糖尿病大鼠神经病理性痛中的作用

目的探讨p38丝裂原活化蛋白激酶（p38MAPK）在链脲菌素诱导的糖尿病大鼠神经病理性痛中的作用。方法雌性Wistar大鼠31只，3月龄，体重180～220g，随机分为3组：对照组（C组，n=10）、糖尿病神经病理性痛组（D组，n=11）和p38MAPK抑制剂组（Ⅰ组，n=10）。D组、Ⅰ组单次腹腔注射链脲菌素65mg／kg制备糖尿病模型。糖尿病模型制备成功后，Ⅰ组尾静脉注射p38MAPK抑制剂SB203580 0．5mg／kg，1次／周，连续4周；C组和D组尾静脉注射等体积的生理盐水。给药4周后，测定机械缩足反应阈值（MWT）、左侧坐骨神经传导速率（NCV）、背根神经节（DRG）和脊髓的磷酸化p38MAPK水平。结果与C组比较，D组、Ⅰ组MWT下降，NCV减慢，伴有脱髓鞘现象，DRG和脊髓的磷酸化p38MAPK水平升高；与D组比较，Ⅰ组MWT升高，NCV增快，脱髓鞘程度减轻，DRG和脊髓的磷酸化p38MAPK水平下降。结论p38MAPK信号转导通路参与了糖尿病大鼠神经病理性痛的形成。     

部分背根切断对备用背根节NT-3表达的影响

目的　探讨部分去背根后备用背根节 (L6 )各类细胞NT 3及其mRNA的含量变化。　方法　对成年雄性猫行单侧部分背根切断术 (切除一侧L1 ～L5,L7～S2 DRG ,保留L6 为备用根 )。取正常组一侧和术后 3d及 7d组手术侧的L6 DRG制作 2 0 μm厚冰冻切片 ,分别用NT 3抗体及NT 3cRNA探针行免疫组织化学及原位杂交染色。观察NT 3及其mRNA在DRG各类细胞的分布 ,测定NT 3及其mRNA在神经元和卫星细胞的光密度值 ,所得数据用q检验进行统计分析。　结果　部分去背根后 ,各时相备用背根节大神经元内NT 3的光密度值较正常者进行性减少 ,(P <0 0 5 ) ,而NT 3mRNA的光密度值术后 3d减少 ,7d回升至近正常者水平。比较之 ,小神经元和卫星细胞NT 3及其mRNA的光密度值进行性增多 (P <0 0 5 )。　结论　部分背根切断对备用背根节各类细胞NT 3表达的影响不同 ,其功能意义可能与NT 3参与脊髓Ⅱ板层可塑性有关     

甲氨喋呤对胶原诱导性关节炎大鼠滑膜骨桥蛋白和整合素αVβ3表达的影响

目的 探讨甲氨喋呤对胶原诱导性关节炎(collagen-induced arthritis,CIA)大鼠滑膜骨桥蛋白(osteopontin,OPN)及其受体整合素αvβ3表达的影响及其作用机制.方法 建立CIA大鼠模型,分为模型组和甲氨喋呤(MTX)组,后者用MTX进行干预治疗;采用免疫组织化学染色技术检测滑膜组织OPN和整合素αvβ3的表达,ELISA方法检测血清TNF-α水平.结果 ① CIA模型组和MTX组大鼠的滑膜OPN、整合素αvβ3表达均明显高于正常大鼠对照组(均为P<0.01);与模型组比较,MTX组OPN和整合素αVβ3的表达减少(均为P<0.01). ②正常对照组和MTX组大鼠血清TNF-α水平显著性低于模型组大鼠(均为P<0.01).结论 滑膜OPN和整合素αvβ3异常表达在CIA发病中具有重要意义.MTX通过下调滑膜OPN和整合素αvβ3的表达,降低血清TNF-α水平从而达到治疗CIA的作用.     

Tyrosine phosphatase-like protein (IA-2) and glutamic acid decarboxylase (GAD65) autoantibodies: a study of Chinese patients with diabetes mellitus

Type 1 diabetes in most Asian populations may not have a salient autoimmune basis when assessed with single determinations of the major markers, islet cell antibodies (ICAs) and glutamic acid decarboxylase antibodies (GAD65ab). With the inclusion of antibodies to tyrosine phosphatase-like protein IA-2 (IA-2ab) as an additional major marker, we re-examined autoimmune diabetes in a group of Chinese patients. We studied 272 subjects at various stages of disease with blood samples procured for biochemical analysis. ICAs were measured by immunofluorescence, GAD65ab and IA-2ab by radioimmunoassay. Sixty-seven patients fulfilled clinical diagnosis of type 1 diabetes and the remaining 205 patients were type 2. Prevalence of single autoantibody type in recent-onset type 1 diabetes ( < 1 year duration; n = 47) showed 10.6% with ICAs, 44.7% GAD65ab and 36.2% IA-2ab. GAD65ab account for more than two-thirds of the markers found in type 1 diabetes. Combined analysis further showed that 51.1% had at least one antibody type, 31.9% with two or more antibodies and 8.5% with all three antibodies. Islet autoimmunity presence in childhood-onset type 1 diabetes improved with the addition of IA-2ab, though less impact was seen in the adult-onset. Similarly, combined analysis for type 2 patients with recent diabetes showed a modest increase to 13% with islet autoimmunity compared to 8% when assessed by GAD65ab alone. Combining IA-2ab and GAD65ab assays results detected slightly more immune-mediated diabetes, compared to using a single GAD65ab determination. Non-autoimmune causes need to be considered in the pathogenesis of type 1 diabetes in Chinese, particularly in adults.     

Human uterine lymphocytes

During the luteal phase and the early months of pregnancy, there is a dense mucosal infiltration of CD56+ natural killer (NK) cells. These uterine NK cells have a phenotype (CD56bright, CD16-, mCD3-) which distinguishes them from peripheral blood NK cells (CD56dim, CD16bright, mCD3-). The uterine NK cells are in close association with extravillous trophoblast (EVT) cells which infiltrate into the decidua and maternal spiral arteries. This subpopulation of trophoblast expresses two human leukocyte antigen (HLA) class I molecules, HLA-G and HLA-C. Circulating NK cells express receptors for HLA class I molecules. We have recently found evidence that similar receptors are present on decidual NK cells belonging to both the Killer Inhibitory Receptor (KIR) and CD94 families. The repertoire of NK receptors expressed varies between different women. The findings indicate that decidual NK cells do have receptors for trophoblast HLA class I molecules. Experiments are underway to determine the effects of this interaction on NK cell function.     

Lack of correlation between expression of Epstein-Barr virus (EBV) latent membrane protein and bcl-2 oncoprotein in vivo.

AIMS--To evaluate whether there is any correlation between the expression of Epstein-Barr virus (EBV) latent membrane protein (LMP) and oncoprotein bcl-2 in the lymph node biopsy specimens of a Chinese patient with EBV-related reactive lymphoproliferation who later developed T cell lymphoma after a short period of time. METHODS--Immunohistochemistry, with a standard alkaline phosphatase antialkaline phosphatase (APAAP) method and New Fuchsin as a chromogen, was used for single staining of bcl-2 or LMP. Double immunostaining combining APAAP and indirect immunofluorescence was performed for dual labelling of LMP and bcl-2. RESULTS--bcl-2 was expressed in 10-30% of cells in the first lymph node biopsy specimen (EBV-associated lymphoproliferative disorder) and 30-50% of cells in the second lymph node biopsy specimen (T cell lymphoma). LMP was expressed in the first biopsy specimen but not in the second. Double immunostaining results showed that around 78% of LMP positive cells were bcl-2 negative and 94% bcl-2 positive cells were LMP negative. Among the very small fraction of LMP and bcl-2 double positive cells, the intensity of bcl-2 staining was heterogeneous and was not always stronger than that observed in LMP negative bcl-2 positive cells. CONCLUSIONS--The expression of bcl-2 protein is independent of LMP protein status in vivo. Several mechanisms may be involved in EBV associated lymphomagenesis, and bcl-2 induction may occur independently of LMP expression.     

肾上腺髓质素对豚鼠心室肌细胞L-型钙通道的作用及其信号转导机制

目的: 研究肾上腺髓质素( adrenomedullin, ADM)抑制豚鼠心室肌细胞L-型钙通道的信号转导机制。方法: 应用全细胞膜片钳技术,记录应用ADM(1-100 nmol·L^-1)前后L-型钙电流(I_Ca,L),以及分别记录应用ADM特异性受体拮抗剂ADM_22-52(100 nmol·L^-1)+ADM(100 nmol·L^-1)、蛋白激酶A (PKA) 特异性拮抗剂H-89(10 μmol·L^-1) + ADM(100 nmol·L^-1)、蛋白激酶C (PKC) 特异性拮抗剂PKC_19-36(10 μmol·L^-1)+ADM(100 nmol·L^-1)、PKC特异性激动剂PMA(1 μmol·L^-1)前后I_Ca,L。结果: ADM(1-100 nmol·L^-1)浓度依赖性地抑制豚鼠心室肌细胞I_Ca,L,并可被ADM_22-52(100 nmol·L^-1)完全阻断;H-89(10 μmol·L^-1)对ADM抑制I_Ca,L的作用无影响。PKC_19-36(10 μmol·L^-1)可完全阻断ADM 对I_Ca,L的抑制效应,且PMA(1 μmol·L^-1)可模拟ADM 对I_Ca,L的抑制效应。结论: ADM作用于特异性ADM受体可浓度依赖性地抑制豚鼠心室肌细胞I_Ca,L,此作用有可能与PKC激活相关。     

Epstein-Barr virus DNA in nasopharyngeal carcinomas from Chinese patients in Hong Kong.

AIMS: To investigate the presence of Epstein-Barr virus (EBV) in cases of nasopharyngeal carcinoma (NPC) in Chinese patients living in Hong Kong. METHODS: Nasopharyngeal biopsy specimens, formalin fixed and paraffin wax embedded, from 24 patients, eight with undifferentiated nasopharyngeal carcinoma, eight with well differentiated squamous carcinoma, and eight showing normal tissue histology, were analysed for the presence of Epstein-Barr virus (EBV) DNA by slot-blot hybridisation on extracted unamplified DNA, and also after amplification of EBV specific sequences by the polymerase chain reaction (PCR). RESULTS: DNA slot-blot analysis showed viral DNA in all the undifferentiated, five of the well differentiated tumours, and none of the normal biopsy specimens. PCR studies confirmed positivity in the eight undifferentiated tumours, but six of the well differentiated tumours and three of the normal biopsy specimens showed viral DNA by this method, illustrating its greater sensitivity. CONCLUSIONS: EBV genome is present in appreciable copy number in most cases of well differentiated NPC in Chinese patients in Hong Kong.     

Wound dressing with sustained anti-microbial capability

Amphiphilic poly(ether ester amide) (PEEA) multiblock copolymers were synthesized by polycondensation in the melt from hydrophilic poly(ethylene glycol) (PEG), 1,4-dihydroxybutane and short bisester-bisamide blocks. These amide blocks were prepared by reaction of 1,4-diaminobutane with dimethyl adipate in the melt. A range of multiblock copolymers were prepared, with PEG contents varying from 23-66 wt %. The intrinsic viscosity of the PEEA polymers varied from 0.58-0.78. Differential scanning calorimetry showed melting transitions for the PEG blocks and for the amide-ester blocks, suggesting a phase separated structure. Both the melting temperature and the crystallinity of the hard amide-ester segments decreased with increasing PEG content of the polymers. The equilibrium swelling ratio in phosphate buffered saline (PBS) increased with increasing amount of PEG in the polymers and varied from 1.7 to 3.7, whereas the polymer that contained 66 wt % PEG was soluble in PBS. During incubation of PEEA films in PBS, weight loss and a continuous decrease in the resulting inherent polymer viscosity was observed. The rate of degradation increased with increasing PEG content. The composition of the remaining matrices did not change during degradation. A preliminary investigation of the protein release characteristics of these PEEA copolymers showed that release of the model protein lysozyme was proportional to the square root of time. The release rate was found to increase with increasing degree of swelling of the polymers.