巨噬细胞源性神经营养因子的初步分离

本文制备了巨噬细胞条件培养基（ＭφＣＭ），并应用快速自动比色微量分析法检测ＭφＣＭ对体外培养的生后７ｄＳＤ大鼠小脑皮质神经元的作用。结果表明，分子量大于１０ｋＤ的ＭφＣＭ对神经元（细胞密度１×１０６／ｍｌ）的作用，与对照组比较有明显的神经营养活性（Ｆ＜０．０５）；用盖玻片培养法表明，该组份有促进神经元突起生长的作用。ＭφＣＭ经ＳｅｐｈａｃｒｙｌＳ－１００－ＨＲ凝胶层析和生物活性鉴定，获得了具有神经营养活性的第二峰洗脱液。此洗脱液经ＳＤＳ－聚丙烯酰胺凝胶电泳分析，证明ＭφＣＭ中神经营养活性成份的蛋白质其分子量为３１ｋＤ－６８ｋＤ之间。     

近代甲状腺功能检查新策略的初步临床评估

本文观察研究了九组共263例循环血TT4、TT3、FT4、TF3，经数理统计和临床综合分析判断，这些测定值生理，病理含义，临床价值不尽雷同。TT4、TT3是现今临床甲状腺功能检验常用，多用、频用的方法，仍不失为一种金试验。FT4、FT3测定方法灵敏，方法学上仍有争论，TT4、TT3留存的临床问题，FT4、FT3亦常存在，且易发生；FT4、FT3试剂盒价贵，在价格论——效益分析上也应商榷。当前我国临床应用策略上似仍以TT4、TT3、FT3、s-TSH；甲状腺疾病；非甲状腺疾病。     

Long-term regulation of N-methyl-D-aspartate receptor subunits and associated synaptic proteins following hippocampal synaptic plasticity

Synaptic plasticity in the dentate gyrus is dependent on activation of the N-methyl-D-aspartate (NMDA)-subtype of glutamate receptors. In this study, we show that synaptic plasticity in turn regulates NMDA receptors, since subunits of the NMDA receptor complex are bidirectionally and independently regulated in the dentate gyrus following activation of perforant synapses in awake animals. Low-frequency stimulation that produced a mild synaptic depression resulted in a decrease in the NMDA receptor subunits NR1 and NR2B 48 h following stimulation. High-frequency stimulation that produced long-term potentiation resulted in an increase in NR1 and NR2B at the same time point. Further investigations revealed that in contrast to NR2B, NR1 levels increased gradually after long-term potentiation induction, reaching a peak level at 48 h, and were insensitive to the competitive NMDA receptor antagonist 3-3(2-carboxypiperazin-4-yl) propyl-1-phosphate. The increased levels of NR1 and NR2B at 48 h were found associated with synaptic membranes and with increased NMDA receptor-associated proteins, postsynaptic density protein 95, neuronal nitric oxide synthase and Ca(2+)/calmodulin-dependent protein kinase II, alpha subunit. These data suggest that the persistence of long-term potentiation is associated with an increase in the number of NMDA receptor complexes, which may be indicative of an increase in synaptic contact area.     

Role of the CCR5 delta 32 allele in resistance to HIV-1 infection in west Africa

OBJECTIVE: To determine the frequency of the mutant CCR5 delta 32 allele in high-risk HIV-seronegative Africans as compared with the general African population, and to assess its in vitro protective efficacy against HIV-1 infection. STUDY DESIGN: In the homozygous form, the CCR5 delta 32 allele confers resistance to macrophage-tropic (M-tropic) strains of HIV-1. Assuming that genetic characteristics favoring HIV resistance would prevail in a high-risk HIV-seronegative population, we examined the CCR5 genotypes of female commercial sex workers (CSWs) from Dakar, Senegal, who have remained uninfected for an elongated period. METHODS: The CCR5 genetic profile of study participants was determined by polymerase chain reaction (PCR) amplification of genomic DNA followed by sequencing. Peripheral blood mononuclear cells (PBMCs) were infected with different strains of HIV-1 and monitored by p24 enzyme-linked immunosorbent assay (ELISA). RESULTS: We confirmed the presence of two CCR5wt/delta 32 genotypes among 139 individuals (1.44%). PBMCs from these 2 heterozygous individuals were also found to be less susceptible to in vitro infection by an M-tropic HIV-1 primary isolate. CONCLUSIONS: Evidence was found of an increased prevalence of the CCR5wt/delta 32 genotype in a high-risk HIV-seronegative cohort in West Africa. Furthermore, reduced susceptibility to HIV-1 infection among heterozygous individuals supports a role for 32-bp CCR5 deletion in HIV-1 resistance.     

大鼠肝抑素纯化及其生物活性的检测

用ＳｅｐｈａｄｅｃＧ－５凝胶过滤层析法，进一步纯化具肝抑素生物活性的大鼠肝蛋白质粗提品，以分离的大鼠再生肝的肝细胞为靶细胞，体外检测各洗脱峰浓缩物对肝细胞增殖的制率结果证明，Ｅ峰浓缩物的抑制作用最强，其活性比为粗提品的２０倍，ＳＤＳ聚丙烯酰胺电泳图及蛋白质迁移率测定表明，该浓缩物的主要成分为分子量１３．５ｋＤ的多肽。本研究对大鼠肝抑素做了初步纯化，验证了该物质在肝再生中起重要调控作用的生物效应。     

Genetic variation screening and association studies of the adenylate cyclase activating polypeptide 1 (ADCYAP1) gene in patients with type 2 diabetes

Adenylate cyclase activating polypeptide 1 (ADCYAP1) is a pancreatic neuropeptide and modulates glucose-stimulated insulin secretion. The ADCYAP1 gene is located on chromosome 18p11 linked to type 2 diabetes. To test whether it is a candidate gene for type 2 diabetes, screening of the gene in Finnish and Swedish type 2 diabetic patients was done. Two novel SNPs, g.9863G>A (G54D) in exon 3 and g.12712C>G in the 3'-UTR of exon 5 of the ADCYAP1 gene (accession number X60435), were found. PCR-RFLP genotyping was then performed in a total of 253 type 2 diabetic patients and 253 non-diabetic control subjects. Transmission disequilibrium test (TDT) was performed in 132 parent-offspring trios. The G allele frequencies of g.9863G>A (G54D) and g.12712C>G of the ADCYAP1 gene were higher in type 2 diabetic patients than in non-diabetic control subjects (21.0% vs 15.8%, P=0.04; 5.3% vs 3.0%, P=0.045). However, no significant differences in clinical variables was seen between the different genotype carriers, and also no transmission distortion of the G allele of SNP g.9863G>A (G54D) was observed in 132 parent-offspring trios. The present study thus suggest that the variants in the ADCYAP1 gene may not be major influence of the susceptibility to type 2 diabetes in Finnish and Swedish Caucasians.     

Heterogeneity of brainstem blood flow response to hypoxia in the anesthetized rat

Cerebral blood flow is strictly regulated during hypoxic stress. Because of the preponderant role of the brainstem in cardiorespiratory controls, blood flow response to hypoxia is stronger in this region than in the cortex. However, the brainstem is made up of various regions which differ in their responsiveness to chemical stimuli. The objective of this study was to evaluate the distribution of blood flow during hypoxia using microsphere deposition methods in three brainstem regions containing key structures in cardiorespiratory controls: the nucleus tractus solitarus (NTS), the ventral respiratory groups (VRG) and the pontine respiratory groups (PRG). Microsphere injections were made during normoxia (FIO2=0.21) and after 15 min of hypoxia (FIO2=0.21). Based on this index, blood flow increase during hypoxia was higher in the VRG than in the dorsal part of the brainstem, containing the NTS and the PRG (P=0.002, n=10). These results suggest that blood flow response to hypoxia favours O(2) delivery in brainstem regions involved in respiratory rhythm generation.     

严重急性呼吸综合征患者尸解肺标本的病理改变和致病机制研究

目的研究严重急性呼吸综合征（SARS）患者尸解肺标本的病理改变和致病机制。方法观察了2003年4-7月期间死于SARS的6例患者的肺标本,并采用光镜、电镜、Masson三色染色和免疫组织化学染色方法（EnVision法）进行研究。结果肺标本的病理形态改变：（1）6例的双肺均可见到弥漫性实变病灶,肺重量明显增加;（2）6例均可见到弥漫性肺泡损伤,包括透明膜形成、肺泡腔内水肿／出血、纤维素沉积和肺泡上皮细胞脱屑,AE1／AE3免疫组织化学染色显示肺泡上皮细胞的完整性明显破坏;（3）Ⅱ型肺泡上皮细胞轻度增生,有一定异型性,细胞体积增大,胞质呈双染性和颗粒状,胞质内可见小脂肪空泡聚集（5／6）;（4）6例中有5例可见巨细胞在肺泡内浸润,巨细胞大多AEl／AE3阳性（5／6）,少数CD68阳性（2／6）;（5）组织学形态和免疫组织化学染色证实肺泡腔内和肺泡间隔内有多量巨噬细胞浸润（6／6）;（6）6例中有5例可见巨噬细胞噬红细胞象;（7）6例中有5例可见肺纤维化,包括肺泡间隔和肺间质增宽（5／6）、肺泡腔内渗出物机化（6／6）和胸膜增厚（4／6）。Masson三色染色证实胶原纤维明显增生,免疫组织化学染色显示大多数为Ⅲ型胶原。光镜和免疫组织化学染色显示5例有明显的成纤维细胞／肌纤维母细胞增生灶;（8）5例可见支气管黏膜鳞状上皮化生;（9）6例患者均可见血栓;（10）2例同时合并其他感染,1例合并细菌感染,另1例合并真菌感染。此外,电镜发现在肺泡上皮细胞和肺血管内皮细胞的胞质内有冠状病毒样颗粒。结论SARS冠状病毒直接损伤肺泡上皮细胞、巨噬细胞明显浸润和成纤维细胞／肌纤维母细胞显著增生在SARS的致病机制中起重要作用。