低氧预处理对缺血性卒中脑保护作用的机制

机体对环境的适应是机体生存的必要条件.机体缺血、缺氧对细胞的损伤程度取决于促进和抑制细胞坏死和(或)凋亡这两个过程的平衡.

Endoplasmic reticulum stress is closely involved in the early stage of diabetic retinopathy. In the present study, a streptozotocin-induced diabetic animal model was given an intraperitoneal injection of tauroursodeoxycholic acid. Results from immunofluorescent co-localization experiments showed that both caspase-12 protein and c-Jun N-terminal kinase 1 phosphorylation levels significantly in-creased, which was associated with retinal ganglion celldeath in diabetic retinas. The C/ERB ho-mologous protein pathway directly contributed to glial reactivity, and was subsequently responsible for neuronal loss and vascular abnormalities in diabetic retinopathy. Our experimental findings in-dicate that endoplasmic reticulum stress plays an important role in diabetes-induced retinal neu-ronal loss and vascular abnormalities, and that inhibiting the activation of the endoplasmic reticulum stress pathway provides effective protection against diabetic retinopathy.

门急诊医务人员对传染病的自身防护

2003春天,SARS的暴发流行给我们带来了巨大的灾难,传染病的暴发流行并不罕见,但很少有一种传染病象SARS一样,使如此众多的医务人员感染,同时很多门急诊、住院病人以及探视家属发生医院内感染,使得治病救人的医院成了SARS的疫源地.因此,了解传染病防护的知识,对于减少传染病传播的机会是十分重要的.门急诊医务人员是接触病人的首诊者,其危险性不言而喻.下面结合传染病的特点,谈谈门急诊医务人员在传染病防护上的注意事项.

Cell-mediated immune responses are crucial in the protection against tuberculosis. In this study, we constructed epitope DNA vaccines (p3-M-38) encoding cytotoxic T lymphocyte (CTL) epitopes of MPT64 and 38 kDa proteins of Mycobacterium tuberculosis. In order to observe the influence of spacer sequence (Ala-Ala-Tyr) or ubiquitin (UbGR) on the efficacy of the two CTL epitopes, we also constructed DNA vaccines, p3-M-S(spacer)-38, p3-Ub (UbGR)-M-S-38 and p3-Ub-M-38. The immune responses elicited by the four DNA vaccines were tested in C57BL/6 (H-2b) mice. The cytotoxicity of T cells was detected by LDH-release method and by enzyme-linked immunospot assay for epitope-specific cells secreting interferon-gamma. The results showed that DNA immunization with p3-M-38 vaccine could induce epitope-specific CD8+ CTL response and that the spacer sequence (AAY) only enhanced M epitope presentation. The protein-targeting sequence (UbGR) enhanced the immunogenicity of the two epitopes. The finding that defined spacer sequences at C-terminus and protein-targeting degradation modulated the immune response of epitope string DNA vaccines will be of importance for the further development of multi-epitope DNA vaccines against tuberculosis.

促炎细胞因子与卒中复发性风险的相关性

有关促炎细胞因子与首发性或复发性卒中风险的报告为数不多.在一项来自培哚普利预防复发性卒中研究(Perindopril Protection Against Recurrent Stroke Study,PROGRESS)的巢式病例对照研究中,英国格拉斯哥大学皇家医院的Welsh等对白细胞介素(interleukin,IL)-6、IL-18和肿瘤坏死因子(tumor necrosis factor,TNF)-α与复发性卒中的相关性进行了研究.

医务人员预防SARS的个人防护

SARS具有较强的传染性,医务人员在治疗或护理SARS病人时,具有较高的感染机会.做好个人防护,是医务人员预防感染SARS的关键.

This study investigated the protection against the ND in chickens by a recombinant DNA vaccine. A plasmid vector encoding NDV F protein, which is reqired for virus cell fusion and is important for vaccine induced immunity, was used as a model to study how DNA vaccines may be modulated by the simulaneous expression of chicken IL-2. The NDV D26 strain F gene with CMV promotor and BGH polyA signal sequence was amplified by PCR from eukaryotic plasmid pcDNA-F, which contains the full-length NDV F gene, and clond into reconstructed eukaryotic plasmid pcDNA-IL2, which contains chicken IL-2 gene. Restriction endonuclease cleavage and PCR amplification showed that a bicistronic plasmid encoding NDV F gene and chicken IL-2 separately was successfully constructed. Two-week-old SPF chickens were intramuscularly innoculated the recombinant plasmid. Antibody and lymphocyte proliferative assay showed that the humoral and cellular immunity of chickens vaccinated the recombinant plasmid greatly increased compared with those innoculated only plasmid expressing NDV F protein. Challenged with the lethal dose of NDV F48E9 strain, 72% chickens vaccinated recombinant plasmid were survived, and 30% chickens vaccinated plasmid expressing F protein were survived. These results proved the adjuvant effect of chicken IL-2, and further showed that the efficacy of a DNA vaccine can be greatly improved by simultaneous expression of IL-2.

HSF1 is the major heat shock transcription factor that binds heat shock element (HSE) in the promoter of heat shock proteins (HSPs) and controls rapid HSP induction in cells subjected to various stresses such as elevated temperature, chemicals, or exposure to toxins. Although at least four members of the vertebrate HSF have been cloned, details of their individual physiological roles remain relatively obscure. To clarify the exact in vivo functions of HSF1 and assess whether HSF1 exhibits redundant or unique roles, we have created homozygous Hsf1-/- mice using standard gene targeting techniques and isolated Hsf1-/- embryonic fibroblasts. Here we demonstrate that heat shock response (HSR) was not attainable in Hsf1-/- embryonic fibroblasts, and this response was required for thermotolerance and protection against heat-induced apoptosis, and that homozygous Hsf1-/- mice, which survived to adulthood according to genetic background, exhibited multiple phenotypes including: (1) placental defects that reduced embryonic viability after late midgestation (day 13.5); (2) growth retardation; (3) female infertility caused by preimplantation lethality, and (4) increased mortality (+/+ vs -/-, P＜0.05) and exaggerated production of proinflammatory cytokine, TNF α (+/-　vs -/-, P＜0.05) after endotoxin challenge. Interestingly, although Hsf1-/- mice exhibited placental defects and embryonic death, basal HSP expression is not appreciably altered during embryonic development by the HSF1 null mutation, suggesting this factor might be involved in regulating some non-HSP genes or signaling pathways which may be important for development. Taken together, our results established direct causal effects for the HSF1 transactivator in regulating diverse physiological and pathophysiological conditions such as developnent, growth, reproduction, apoptosis and sepsis. The present work also provided a useful mammalian model for further investigating the implications of Hsf1 and its target genes (HSPs and other possible non-HSP genes) in various physiological and pathophysiological processes.