中国沿海养殖牡蛎尼氏单孢子虫感染情况调查

单孢子虫病是严重危害世界贝类养殖业的主要疫病之一。本研究选取中国沿海养殖的牡蛎作为研究对象,采用OIE推荐的PCR方法结合测序技术,对采自中国沿海4个监测点养殖牡蛎的感染情况进行调查,结果表明,这些监测点养殖的牡蛎均不同程度感染了单孢子虫。经PCR测序及序列分析表明感染种类均为尼尔森单孢子虫(Haplosporidium nelsoni)。     

应激诱导对蓝狐自咬症及血清生化指标的影响

本研究模拟蓝狐在饲养管理过程中的不良环境,结合10种血清生化指标研究环境应激对蓝狐自咬症发生的影响。选用体重相近的健康蓝狐90只(公母各半),其中试验组60只,对照组30只。采用摇床、转移栋舍、限制、拥挤、饥饿、休息等6种不同的应激诱导方式对蓝狐进行应激诱导,结果显示,应激诱导持续30 d,试验组血清中GPT、ALP、GSH-Px和CAT活性极显著低于对照组(P＜0.01),MDA含量显著低于对照组(P＜0.05),SOD活性极显著高于对照组(P＜0.01);应激诱导60 d,ALP、CK、GSH-Px、CAT和MDA活性极显著高于对照组(P＜0.01),SOD活性极显著低于对照组(P＜0.01),GPT活性显著低于对照组(P＜0.05);GOT、LDH、GLU活性在整个应激诱导过程中没有显著差异(P＞0.05)。应激诱导组与对照组蓝狐自咬症发病率没有显著差异(P＞0.05),一般的环境应激对蓝狐自咬症的产生没有明显影响。     

Protective role of losartan in reversion of hypertensive calcium overload and glomerular injury

AIM:To investigate the relation between cytosolic calcium and glomerular injury in hypertension.METHODS:The normotensive control (WKY) and spontaneously hypertensive rat group(SHR) with or without treatment (losartan 20 mg·kg^-1·d^-1) were compared. Intralymphocytic free calcium level and ultrastructural changes in glomerulus were observed at three and eight months, respectively.RESULTS: The results demonstrated early impairment in glomerulus and elevation of cytosolic calcium at three months in SHR group, at eight months, aggravation of impairment in glomerulus correlating with calcium elevation was shown. Losartan significantly attenuated the above pathologic changes. CONCLUSION:Calcium-overload state was not only related to blood pressure and vessel impairment, but also associated with glomerular injury, which could be reversed by losartan.     

Inhibitory effect of ATP on proliferative signaling in immortalized human fibroblasts

AIM: To investigate the inhibitory effects of ATP on proliferation signaling in immortalized human fibroblasts. METHODS: Immortalized human fibroblasts were treated with ATP, ATP conbined with calcium or potassium channel antagonists, respectively. The intracelluar-free calcium ([Ca²⁺]i), inositol 1,4,5-trisphosphate(IP₃) levels and cell viability were detected at different time points. RESULTS: ATP significantly increased the [Ca²⁺]i and decreased the IP₃ level in immortalized human fibroblasts, especially at initial stage (P＜0.01) . Compared to ATP alone, the proliferation rates remarkably increased when calcium or potassium channel antagonists were used (P＜0.01, respectively) with ATP. CONCLUSION: The calcium and potassium channels and IP₃ involved in the inhibitory effects of ATP on the proliferative signaling in immortalized human fibroblasts.     

Effect of heterogenic corneal stroma transplantation on peripheral T cells of rats

AIM: To Compare immunogenicity of three kinds of heterogenic corneal stroma. METHODS: 36 SD rats were randomized into 4 groups, each group consisting of 9 rats. Group 1 was control group. Three kinds of heterogenic corneal stroma: porcine, rabbit and chicken corneal stroma were heterotopically transplanted to subcutaneous layer of 27 (group 2-4) SD rats, respectively. The expression of CD4⁺, CD8⁺, CD25⁺, CD71⁺ on peripheral T cells was identified and analyzed by dual fluorescence flow cytometry at 7, 14, 28 days after operation. RESULTS: Compared with control group, the expression of CD4⁺, CD8⁺, CD25⁺, CD71⁺ was no significant change in porcine corneal stroma group(P＞0.05), the expression of CD4⁺ was increased in rabbit corneal stroma (P＜0.05), CD4⁺, CD4⁺ CD71⁺ markedly higher in the chicken corneal stroma (P＜0.01) at 7 days after operation. CONCLUSION: The immunogenicity of porcine stroma is the lowest in three kinds of heterogenic corneal stroma (chicken, rabbit and porcine).     

Dexamethason enhanced aorta-derived CD105+ mesenchymal stem cells to differentiate into adipocytes

AIM: To investigate whether aorta-derived CD₁₀₅⁺ cells show characteristics of mesenchymal stem cells, and if dexamethason enhances this kind of CD₁₀₅⁺ cells to differentiate into adipocytes. METHODS: The distribution of CD105 in aorta was assessed by imunohistochemistry. The aorta wall cells were isolated and immunophenotypes were identified by FACS. CD₁₀₅⁺ cells were sorted using MACS CD105 micromagnetic beads. The differentiation of CD₁₀₅⁺ cells into adipocytes and osteoblasts was induced under different conditions and indicated by staining of Oil red O, detecting of alkaline phosphatase activity, calcium accumulation stained with silver nitrate and transmission electron microscope analysis, respectively. RESULTS: The endothelial cells, a part of medial smooth muscle cells and adventital fibrblasts were CD105 positive. The isolated aortic arch cells were positive for CD105, CD106, CD44, CD29, and negative for CD45, CD11a, CD11b and HLADR. The CD₁₀₅⁺ cells differentiated into adipocytes contained Oil-Red-O-positive lipid droplets, the osteocytes with calcium deposition and alkaline phosphatase activity. Ultrastructurally, it was observed that some needle-shaped crystal calcium deposition similar to bone spicules was inside the cytoplasm of induced osteocytes. When the dexamethason was absent in the adipogenic medium, there were no adipocytes with lipid droplets. CONCLUSION: The results demonstrated that CD₁₀₅⁺ cells showed characters of MSCs reside in aortic wall, and was able to differentiate into adipocytes and osteocytes in vitro. Dexamethason enhanced aorta-derived CD₁₀₅⁺ with characters of MSCs to differentiate into adipocytes. These suggested that MSCs might be related with atherosclerosis.     

Molecular mechanism of Chinese medicine formula (Bushen Bugu Tang) for the treatment of postmenopausal osteoporosis

AIM: To study the molecular mechanism of Chinese medicine formula Bushen Bugu Tang (BSBGT) for the treatment of postmenopausal osteoporosis (PMO). METHODS: Forty female SD rats were divided into four groups: the sham group, OVX group, estrogen treatment group and BSBGT treatment group, ten for each, difference operation and treatment were given. Subsequently, bone mineral density (BMD), bone histomorphometric changes and collagen type I expression in the femur of these rats were examined. In order to position the target of the formula acting on bone, the effect of BSBGT on regulation of mRNA levels of RANKL and OPG, two key factors for regulating osteoclastogenesis, by using rat calvarial-derived stromal cell cultrues, was elucidated. RESULTS: The BSBGT formula was found as effective as estrogen in preventing the reduction of BMD, the trabecular area and trabecular numbers in femora and also the decrease in collagen type I expression following ovariectomy. RT-PCR resulted showed that both estrogen and BSBGT significantly up-regulated OPG mRNA level and down-regulated RANKL mRNA level, resulting in an increased ratio of OPG/RANKL in cultured rat stromal cells. CONCLUSIONS: The ratio of OPG/RANKL within the osseous environment determines whether bone formation predominates bone resorption. We therefore concluded that the BSBGT formula might be as effective as estrogen in prevention of postmenopausal osteoporosis through the mechanism of up-regulating RANKL expression and down-regulating OPG expression in osteoblast/stromal cells.     

Changes of plasma and myocardial calcitonin gene-related peptide in myocardial stunning rats

AIM: To investigate changes of calcitonin gene-related peptide(CGRP) in myocardial stunning rats. METHODS: Rat in vivo myocardial stunning model was used. CGRP content in plasma and myocardium were determined by radioimmunoassay. RESULTS: Plasma level of CGRP increased significantly (P＜0.01), but in left ventricular myocardium CGRP decreased obviously (P＜0.05) in myocardial stunning group compared with the control group. CONCLUSION: CGRP content in the left ventricular myocardium was negatively correlated with plasma CGRP.     

Effect of Ba2+ concentration on L-type Ca2+ channel in hypothalamic neurons

AIM:To investigate the effect of Ba²⁺ concentration on L-type of Ca²⁺ channel in hypothalamic neurons.METHODS:The cell acute isolation technique and cell-attached patch-clamp technique were used.RESULTS:The slope conductance of L-type Ca²⁺ channel were 28.6 pS (110 mmol/L) and 19.1 pS (10 mmol/L), and the open probability (NP₀) obviously different with different Ba²⁺ concentration as carrier. CONCLUSION:Ba²⁺ concentration had the obvious effect on the L-type Ca²⁺ channel.     

Alteration of serum free fatty acids during the carbon tetrachloride-induced fatty liver in rats

AIM: To investigate the alteration of serum free fatty acids in the carbon tetrachloride-induced fatty liver. METHODS: Drug-induced fatty liver rat models were built by injection 40% CCl₄. Serum free fatty acids were analyzed by gas chromatography. RESULTS: In the composition of serun free fatty acids, polyunsaturated fatty acids[oleic acid C18:1,(28.672±7.332/mg·L^-1 vs 41.373±2.180/mg·L^-1),linoleic acid C18:2(16.739±0.871/mg·L^-1 vs 24.959±5.325/mg·L^-1),arachidonic acid C20:4(6.105±2.656/mg·L^-1 vs 9.802±0.779/mg·L^-1),P<0 05], were decreased significantly, but saturated fatty acids [lauric acid C12：0(3.368±0.330/mg·L^-1 vs 2.742 0.351/mg·L^-1),myrist ic acid C14:0(27.136 3.158/mg·L^-1 vs 16.152±0.638/mg·L^-1),palmitic acid C16:0(51.731±9.561/mg·L^-1 vs 34.522±1.401/mg·L^-1),P<0 05] increased. CONCLUSION: Serum polyunsaturated fatty acids were decreased and saturated fatty acids increased in the drug-induced fatty liver.