Antiproliferative effect of c-myc antisense oligonucleotide in rat thymus lymphocytes

AIM: To observe the antiproliferative effect of c-myc antisense oligonucleotide in rat thymus lymphocytes. METHODS: Rat thymus lymphocytes were separated by Ficoll-Urografin density gradient centrifugation. Lipofectin was used to introduce antisense, sense and mismatched oligonucleotides for c-myc to rat thymus lymphocytes. The antiproliferative effect was assayed by incorporation of [³H]-TdR and MTS cell proliferation assay. TR-PCR was used to detect the expression of c-myc mRNA. RESULTS: c-myc antisense oligonucleotide inhibited ratthymus lymphocytes proliferation[(0.14±0.03)A vs(0.32±0.16)A,P<0.05],but this ef ect had no relationship with the concentration of c-myc antisense oligonucleot ide.c-myc antisense oligonucleotide decreased the expression of c-myc mRNA in rat thymus lymphocytes. CONCLUSION: c-myc antisense oligonucleotide inhibited rat thymus lymphocyte proliferation.     

Taurine reduced oxygen free radical production induced by homocysteine in electron transport chain and homocysteine inhibites taurine transporter in mitochondria membrane

AIM: To observe effects of homocysteine and antagonized effects of taurine on electronic leakage and free radical production in myocardial mitochondria. METHODS: Myocardial mitochondria of rat heart was isolated, and was broken by supersonic wave to prepare submitochondria. Recombinant of succinic acid cytochrome c reductase was prepared with mitochondria of porcine heart. They were co-incubated with homocysteine and/or taurine with various concentration. The H₂O₂ and O₂^- were determined by chemiluminescence methods. The taurine transporter of heart mitochondria and its propert, and effects of homocysteine on its function were studied with glass filter. RESULTS: Homocysteine stimulated oxygen free radical production in heart mitochondria, submitochondria, and succinic acid cytochrome c in a concentration-dependent manner. Although taurine itself did not affect oxygen free radical production, taurine did inhibit oxygen free radical production in mitochondria, submitochondria and succinic acid cytochrome c in a concentration-dependent manner. Taurine transporters of Na⁺-dependent were existed in mitochondria membrane. Homocysteine inhibited taurine transtport in mitochondria in a concentration-dependent manner. CONCLUSIONS: Taurine inhibited electronic leakage and oxygen free radical production induced by homocysteine in electron transport chain. There were taurine transporters in mitochondria membrane, and transport functions of taurine transporter were inhibited by homocysteine.     

Effects of glycine on intracellular of free calcium and tumor necrosis factor-α of cardiomyocytes during hypoxia/reoxygenation

AIM: To observe the influence of glycine on intracellular free calcium, the concentration of tumor necrosis factor-α and the survival rate of myocardial cells during hypoxia/reoxygenation (H/R). METHODS: The simulated model of myocardial ischemia-reperfusion with the primary cultured cardiomyocytes of neonatal rats was established, and the cultured cardiomyocytes were divided into seven groups, control group, hypoxia/reoxygenation group, glycine (0.5 mmol/L) plus hypoxia/reoxygenation group, glycine (1.0 mmol/L) plus hypoxia/reoxygenation group, glycine (2.0 mmol/L) plus hypoxia/reoxygenation group, glycine (4.0 mmol/L) plus hypoxia/reoxygenation group, 4.0 mmol/L glycine group. RESULTS: Within certain concentration (0.5-2.0 mmol/L), the glycine could inhibit the calcium overload resulting from hypoxia/reoxygenation injury in cells in a dose-dependent manner with the optimal inhibitory effect at 2.0 mmol/L. Glycine inhibited the secretion of tumor necrosis factor-α from myocardial cells and increased the survival rate of myocardial cells. CONCLUSION: Glycine has a protective effect on hypoxia/reoxygenation myocardial cells, which may be related to inhibiting calcium overload and decreasing the production of tumor necrosis factor-α.     

The molecular mechanism of inhibition of murine Lewis lung carcinoma metastasis by weimaining in vivo

AIM: To investigate the anti-metastasis effect of weimaining, extracted from fragopyrum cymosum meissn, a Chinese medicine, on murine Lewis lung carcinoma (3LL). METHODS: The anti-metastasis effect of weimaining in vivo was detected in the grafting lung metastasis model of murine Lewis lung carcinoma. The effects of the drug on the expression of CD34 and E-cadherin were investigated by immunohistochemical staining and RT-PCR. RESULTS: Weimaining effectively inhibited the lung metastasis of 3LL at a concentration of 250 mg·kg^-1·d^-1, significantly suppressed the expression of CD34 and increased the expression levels of E-cadherin protein and mRNA in 3LL cells. CONCLUSIONS: Weimaining inhibits the metastasis of murine Lewis lung carcinoma (3LL) in vivo via increasing the expression of E-cadherin and decreasing microvessel density of tumor tissue.     

Effect of atrial natriuretic peptide on acute lung injury induced by lipopolysaccharide

AIM: To investigate effect of atrial natriuretic peptide (ANP) on acute lung injury (ALI) induced by lipopolysaccharide (LPS) in rat. METHODS: Mean arterial blood pressure (MAP) was recorded with model 6280 physiology intelligentialize grapher, nitric oxide (NO) and endothelin (ET) concentrations in plasma were measured after lipopolysaccharide (LPS) or following LPS ,ANP was injected into vein in rats. After experiment,lung water as well as pulmonary histopathological changes was measured and observed, respectively. RESULTS: Administration of LPS elicited a persistence decrease in MAP (8.1 kPa±2.6 kPa,at 4 h,P<0.01 vs control); NO and ET concentration in plasma was evident higher than that in control group, respectively (P<0.01); Wet-dry ratio of lung was higher than that in control group (5.15±0.43,at 4 h) (P<0.05); Alveolus detelectasis was observed and pulmonary mesenchyme was thicker than that in control group. No erythrocyte and leukocytes in alveolus,which show an interstitial pulmonary edema, was observed in LPS+ANP group, ANP maintained MAP at higher levels (13.35 kPa±2.93 kPa, at 4 h, P<0.05 vs LPS) after an transient decline when LPS was injected; NO and ET concentration of plasma had all significantly decrease, respectively (P<0.05 vs LPS, at 4 h); Wet-dry ratio of lung was lower than LPS group (4.57±0.35, P<0.05). Compared with control group the ratio was not evident difference (P>0.05); The histopathological of lung displayed markedly improved. CONCLUSION: ANP attenuates ALI induced by LPS in the rat. The effect of ANP may be via decreasing secretion of ET,NO and regulation arterial blood pressure.     

Effects of fosinopril,captopril and valsartan on the expressionof tissue factor in human monocytes

AIM: To investigate the effects of angiotensin-converting enzyme inhibitors (ACEI), fosinopril, captopril and angiotensin II AT₁ antagonists, valsartan on tissue factor (TF) expression on monocytes induced by lipopolysaccharide (LPS). METHODS: Mononuclear leukocytes from normal delivered female umbilical veins were incubated with bacterial LPS in presence or absence of different ACE inhibitors .At the end of incubation, the cells were disrupted by 3 freeze-thaw cycles. TF procoagulant activity was assessed by a one-stage clotting assay. RT-PCR was used to check TF mRNA expression, and GAPDH mRNA was used for parallel assay. RESULTS and CONCLUSION: The results showed that increased expression of TF mRNA induced by LPS was inhibited by fosinopril, captopril and valsartan, respectively, and the procoagualant activity of monocytes was also reduced.     

Recent advances in molecular mechanisms of oncosis

Oncosis is another form of cell death, which is different from apoptosis. The review will discuss the recent advances of oncosis on pathological morphology, nuclear biochemical changes and molecular mechanisms.     

尿素水平对青山羊血液生化指标的影响

应用饲养试验与氮平衡试验,研究了不同尿素水平的日粮对青山羊血清总蛋白(STP)、血清清蛋白(ALB)、血清球蛋白(GLB)、血清清球蛋白比值(A/G)、血清尿素氮(SUN)及血清谷丙转氨酶的含量变化的影响。试验采用4×4拉丁方试验设计,试验分4个阶段,在基础日粮一致的情况下,采用4、9、14、0(对照)g/kg·DM4种不同的处理,试验结果表明:不同尿素水平极显著影响ALB、SUN浓度和GPT活性浓度(P<0.01),对血清清球比(A/G)无显著差异(P>0.05),尿素水平与STP、GLB浓度存在负相关;血清含氮生化指标STP、ALB、GLB、A/G、GPT、SUN随时间呈动态变化,出现高峰的时间比瘤胃氨浓度出现的时间平均推迟1～2h。进食尿素后,血液生化指标由平稳逐渐缓慢升高到高峰,随后又下降并趋于平衡。     

贺兰山西坡不同海拔梯度草地土壤氮特征

以阿拉善左旗境内贺兰山中段(西坡)及山前地带不同海拔下的草地为研究对象,分析不同海拔梯度下草地土壤全氮的分布特征及其与气候因子、植被特征和土壤特性的关系.结果表明,土壤全氮含量随海拔的降低而逐渐降低,在典型草原中沿土壤垂直剖面依次降低,在高寒草甸、荒漠化草原和草原化荒漠0～20与20～40 cm土层中差异不显著,但高于40～60 cm土层.在海拔1 360～1 380 m草原化荒漠的5个样地上,由于放牧利用程度和植被类型的不同,0～20 cm土层土壤氮的含量变幅在0.022 8%～0.034 7%.0～20,20～40和40～60 cm土层土壤全氮含量与年降水量、植被盖度、草地生产力、土壤含水量、有机碳含量和<0.05 mm颗粒含量呈极显著正相关,与年均温、土壤pH值呈极显著负相关(P<0.001).偏相关分析显示,影响0～20 cm土层全氮(TN)含量最主要的因素是植被盖度(C)和年降水量(AP),相关方程是TN%=0.002 040 C 0.000 585 AP-0.076 800;而影响20～40 cm土层全氮含量的最主要因素是草地生产力(B),与土壤全氮回归方程为TN%=0.001 6 B 0.024 7.而各环境因素中影响土壤全氮含量最主要的因素,0～20 cm土层为土壤有机碳和年降水量,20～40 cm土层主要受土壤有机碳的影响.     

β_2兴奋剂莱克多巴胺及其检测技术研究进展

莱克多巴胺(RCT) 属苯酚胺类β肾上腺素激动剂, 因能增强运动员、动物运动肌肉, 提高运动成绩, 被国际奥委会列为禁用兴奋剂药物。同时RCT因具有营养再分配、促进蛋白质合成, 增加酮体瘦肉率, 提高饲料转化率的作用, 有可能作为饲料添加剂用于畜产品的生产, 而其残留对人类健康存在潜在的危害, 被禁止或限定在畜产品生产中使用。因此, 研究RCT的分析测定方法, 对于畜产品的安检和兴奋剂的检测都具有实际意义。本文对兴奋剂莱克多巴胺的药理、毒理性质以及检测方法和国内外研究状况进行了较详细的阐述及讨论。