锌金属硫蛋白对镉致肝肾损伤的修复作用研究

目的：探讨锌金属硫蛋白（Zn-MT）对镉所导致的肝肾毒性的修复作用。方法：以小鼠为研究对象，建立镉中毒动物模型，然后经口给予不同剂量的Zn-MT,测定并分析肝、肾组织中脂质过氧化代谢产物丙二醛（MDA）水平、超氧化物歧化酶（SOD）、谷胱甘肽过氧化酶（GSH－Px）活性及电镜下观察肝肾组织形态学变化。结果：Zn-MT可明显降低肝、肾组织中MDA水平，使肝、肾组织中SOD、GSH－Px活力有一定程度的恢复，且上述作用呈明显的剂量－反应关系；电镜下观察到给予Zn-MT后，肝、肾组织形态学病变得到一定程度的恢复。结论：Zn-MT可对镉所致的肝肾组织脂质过氧化损伤起到一定的修复作用。     

Embryonic develop-associated gene 1 is overexpressed and acts as a tumor promoter in thyroid carcinoma

Embryonic develop-associated gene 1 (EDAG-1), a hematopoietic tissue-specific protein, is usually highly expressed in the placenta, fetal liver, bone marrow and leukemia cells, but the expression status in normal or solid tumor tissues is rarely reported. In this study, we found that EDAG-1 was up-regulated in thyroid carcinoma tissues and cells. Knockdown of EDAG-1 suppressed proliferation and enhanced cisplatin-induced apoptosis of thyroid carcinoma cells. We also demonstrated that knockdown of EDAG-1 inactivated the phosphatidylinositol-3 kinase (PI3K)/Akt signaling pathway in vitro and in vivo. Moreover, knockdown of EDAG-1 suppressed tumorigenesis of thyroid carcinoma in vivo. Taken together, these results suggest that EDAG-1 regulates the proliferation and apoptosis of thyroid carcinoma via the PI3K/Akt signaling pathway.     

Knowledge and awareness about diabetes and periodontal health among Jordanians

The aim of this study is to evaluate the awareness, perception, sources of information, and knowledge of diabetes mellitus and periodontal health among Jordanians, to examine the factors related to their knowledge, and organize effective education programs. A random sample of 500 diabetic patients was recruited from three hospitals and three comprehensive health centers that represent both urban and rural populations in Jordan between September 25, 2006, and February 20, 2007. Completed questionnaires with the answers were returned by 405 participants (response rate was 81%). Only 28% indicated that they followed up gum diseases with the dentist; 48% were aware that diabetic patients are more prone to gum diseases and oral health complications. About a third (38%) recognized that their periodontal health might affect their glycaemic level. Television and Internet were the main source of knowledge for dentists with the rate of 50%. Knowledge about diabetes and periodontal health among diabetic patients is low, and majority of patients were unaware of the oral health complications of their disease and the need for proper preventive care. Issues on education need to be addressed. Therefore, appropriate educational programs should be planned according to community needs, and the target of these programs should be patients with irregular visits to the dentist and physicians. The clinical implication of our findings is that dentists, physicians, and other health providers should inspect diabetic patients for gum diseases each time they come for care and recommend that diabetic patient see a dentist regularly.     

构建网络教学平台 探索预防医学教学新模式

为了进一步提高预防医学的教学效果,广州医学院构建了预防医学网络教学平台以及基于网络资源的预防医学教学新模式,并对2003级五年制临床医学专业60名学生的预防医学课程采用新教学模式教学。教学结束后的问卷调查结果表明,学生对新教学模式给予了较高的评价,网络教学促进了学生的学习并培养了学生多方面的能力。     

Relationship of impairment induced by intracellular S‐adenosylhomocysteine accumulation with DNA methylation in human umbilical vein endothelial cells treated with 3‐deazaadenosine

The aim of this study was to estimate the relationship of endothelial dysfunction induced by intracellular S-adenosylhomocysteine (SAH) accumulation and DNA methylation in human umbilical vein endothelial cells (HUVEC). The isolated HUVEC were incubated with 3-deazaadenosine (DZA) to induce experimental intracellular SAH accumulation. The impairment of HUVEC function was assessed by changes in morphology and proliferative ability. The expression of DNA methyltransferase-1 (DNMT1) and the atherosclerosis related genes [oestrogen receptor-alpha (ER-α), extracellular superoxide dismutase (EC-SOD) and monocyte chemoattractant protein-1 (MCP-1)] were analysed using quantitative real-time PCR. Global DNA methylated status was measured using the cytosine extension assay. The methylated patterns of ER-α, EC-SOD and MCP-1 genes were determined with methylation-specific PCR. We found that DZA administration increased intracellular SAH levels progressively and simultaneously decreased Hcy content in medium. Moreover, the supplementation induced HUVEC apoptosis, inhibited proliferation ability and DNMT1 mRNA expression (P<0.05) and furthermore reduced global DNA methylation status (P<0.05). Correlation analysis showed the presence of a negative correlation between intracellular SAH concentration, proliferative ability, and expression of ER-α, EC-SOD, and DNMT1 (r = −0.89, −0.86, −0.92 and −0.88 respectively, P<0.001); and a positive correlation with MCP-1 expression and DNA [³H]-dCTP incorporation (r = 0.89 and 0.93 respectively, P<0.001). Our results showed that endothelial dysfunction induced by intracellular SAH accumulation is mediated by regulating the expression of atherosclerosis related genes in HUVEC, which is not related with gene promoter methylated patterns, but may be associated with altered global DNA hypomethylated status. These findings suggest that SAH can act as the potential molecular biological marker in the promotion of atherogenesis.