关中平原小麦产量对气候变化区域响应的评价模型研究

根据关中地区宝鸡、西安、渭南与咸阳 4地 (市 )的 1 949～ 1 999年的逐年小麦单产记录序列以及 4地 (市 )的气象观测站点自建站以来至 2 0 0 0年近 5 0年的气象记录序列 ,对关中地区小麦产量与年均温、年降水作相关分析 ;探讨了关中地区小麦单产对气候变化区域响应的评价模型。结果发现 :关中平原气候具有暖干化趋势 ;随着气温变暖 ,小麦产量增加幅度减小 ;小麦产量对降水波动的响应比对气温波动的响应显著。     

发菜形态特征及其与环境因子的关系

通过野外调查和室内观察分析 ,天然发菜原植体的形态主要有柱状和带状两种 ;群体形态有单丝体、团块状、辫状、束状和网状。原植体的形态特征受环境湿度的影响较大 ,在降水量较大的地区 ,发菜原植体增粗 ,直径在 0 .0 5～ 0 .2 5 mm之间 ,带状发菜的比例较大 ,占 30～ 60 % ,吸水后藻体的颜色一般呈棕褐色 ;在降水量较小或极端干旱地区 ,发菜以细丝状为主 ,直径在 0 .0 2～ 0 .2 2 mm之间 ,带状发菜的比例不足 2 5 % ,吸水后藻体的颜色呈绿色或浅棕褐色。发菜群体形态的形成和发育与自身的生长特性有关外 ,主要与环境因子特别是降雨量、地形及自然外力 (地面径流和空气流动 )有关。     

木那格葡萄的组培快繁试验

以木那格葡萄的茎尖、单芽茎段为外植体，进行组培快繁试验。蛄果看出，适宜茎尖分化的培养基为B5 BA1．0mg／L IBA 0．1mg／L。适宜单芽茎段一次成苗生长的培养基为B3 BA0．05mg/L IBA0．2mg／L。适宜的生根培齐基为1／2MS IBA 0．2mg／L 蔗糖40g／L。健壮生根的试管苗要待4片叶以上移栽，移栽基质以蛭石较好。时间宜在4—5月份。     

Induction of apoptosis with Salvia miltiorrhiza monomer IH764-3 via downregulating focal adhesion kinase in H2O2-stimulated hepatic stellate cells

AIM: To investigate the effect of IH764-3 on the apoptosis of H₂O₂-stimulated hepatic stellate cells(HSCs) and the alteration of focal adhesion kinase (FAK). METHODS: The proliferation of HSCs was examined by direct cell count and the apoptosis was determined by Annexin-V/PI labeling, while the morphological change was observed by light microscopy and transmission electron microscopy. In addition, FAK mRNA was detected by RT-PCR. RESULTS: H₂O₂ promoted the proliferation of HSCs. IH764-3 induced the apoptosis of HSCs in a dose-dependent manner. The HSC apoptotic rates of different groups were 6. 35%,9. 28%,15. 10%,19. 69%,respectively, after treated with different concentrations of IH764-3 for 48 h while H₂O₂ group showed 2. 30%. In 30 mg/L group, the apoptosis rates were 6. 73%、10. 34%、15. 10% for the indicated time periods(12 h, 24 h, 48 h). In the presence of IH764-3, FAK mRNA decreased. The FAK mRNA reduction began at 2 h after adding IH764-3. CONCLUSION: IH764-3 induced the apoptosis of HSCs. Down-regulating the expression of FAK mRNA may be one of its mechanisms.     

Bcl-2 antisense oligodeoxynucleotide increases the sensitivity of HL60 and K562 cells to daunorubicin

AIM:To investigate whether the bcl-2 antisense oligonucleotide increases the sensitivity of HL60 and K562 cell lines to daunorubicin.METHODS:IC50 for HL60 and K562 was determined with MTT method, the expression levels of Bcl-2 protein were assayed by immunofluorescence using fluoresce isothiocyanate labeling. In addition, apoptosis was detected by morphological observation and flow cytometric analysis of DNA fragmentation.RESULTS:It was found that the two oligonucleotides directed against the coding region and the translation initiation of bcl-2 mRNA, combined respectively with daunorubicin, inhibited expression of bcl-2 protein, increased apoptosis in HL60 and K562 cells, and decreased IC50 of daunorubicin significantly (P＜0.05). Compared to the antisense oligonucleotide directed against the translation initiation of bcl-2 mRNA, the antisense oligonucleotide directed against the coding region showed stronger effects in the aspects of increasing the sensitivity of HL60 cells to daunorubicin (P＜0.05).CONCLUSIONS:These two antisense sequences in the translation initiation and the coding region of bcl-2 mRNA increased the sensitivity of HL60 and K562 cell lines to daunorubicin in a sequence-specific manner.     

Effect of cGMP on voltage-gated potassium channel in pulmonary artery smooth muscle cells from rats exposed to chronic hypoxia

AIM: To investigate the effect of cGMP on voltage-gated potassium channel in pulmonary artery smooth muscle cells (PASMCs) from rats exposed to chronic hypoxia. METHODS: (1) Wistar rats were randomly divided into control group (group A) and chronic hypoxia group (group B). Then group B received hypoxia 8 hours per day for 4 consecutive weeks. (2) Single PASMC was obtained via acute enzyme separation method. (3) Conventional whole-cell patch clamp technique was used to record resting membrane potential (Em) and ion currents of voltage-gated potassium channel. The changes of ion currents of voltage-gated potassium channel before and after applying cGMP (1 mmol/L), an agonist of protein kinase G (PKG), and cGMP plus H-8 (1 mmol/L), an inhibitor of PKG were compared between two groups. RESULTS: The Em of group B were significantly lower than that of group A. The ion currents of voltage-gated potassium channel in group A and group B were all significantly inhibited by cGMP [control group: from (118.0±5.0) pA/pF to (89.9±16.5) pA/pF, n=6, P＜0.05;chronic hypoxia group: from (81.0±5.0) pA/pF to (56.8±9.1) pA/pF, n=6, P＜0.05]and these effects were reversed by H-8 [control group: from (119.2±10.3) pA/pF to (117.8±9.1) pA/pF, n=6, P＞0.05;chronic hypoxia group: from (96.8±6.2)　pA/pF to (98.0±2.2)　pA/pF, n=6, P＞0.05]. CONCLUSIONS: The currents of voltage-gated potassium channel was inhibited by chronic hypoxic. The inhibitory effect of cGMP on currents of voltage-gated potassium channel in PASMCs from both normal and chronic hypoxic rats may be probably through the phosphorylation of voltage-gated potassium channel.     

Sca-1+ cells from mouse fetal liver can differentiate into neurons in vitro

AIM: To study whether Sca-1⁺ cells from fetal liver can be induced to differentiate into neuronal cells in vitro. METHODS:Sca-1⁺cells from 14 5-days-old murine fetal liver were isolated with a magnetic cell sorting kit, and were cultured in Dulbecco s modif ied Eagle s medium(DMEM)/F12 supplemented with 10%fetal bovine serum(FBS), and passaged at a rat io of 1 3 when cells reached more than 80%confluence.The 5 passage cells were induced by 10^-3mol/Lβ-mercaptoethanol(β-ME)and 5×10^-7 mol/L all-trans-retinoic acid(RA)for 24 hours, and then incubated in serum-free medium for 5 hours to 5 days.The characteristics of treated cel s were assayed by immunocytochemistry staining analysis at 5 hours, or 5 days.RESULTS: Cells treated with β-ME and RA exhibited neuronal phenotype and expressed neuron-specific protein such as neuron-specific nuclear protein (NeuN), neuronfilament-M, and neuron-specific tubulin-1 (TuJ-1) but not tau, MAP-2, or the astrocyte-specific marker glial fibrillary acidic protein (GFAP).CONCLUSION: Sca-1⁺ cells from fetal liver, of which most are regarded as hematopoietic stem cells, could differentiate into early immature neuronal cells in vitro. These findings suggest that Sca-1⁺ cells from fetal liver may be an alternative source in cell therapy and gene therapy of neural dysfunction.     

Effect of cocaine on caspase-3 in myocardiac cells of male rats in different age

AIM: To study the effect of cocaine on caspase-3 in myocardiac cells of male rats in different age. METHODS: Three-week-old(n=16), six-week-old(n=16) and twelve-week-old (n=16) male Sprague-Dawley rats were all divided into control groups and experiment groups randomly, each group had eight animals, experiment groups were given cocaine hydrochloride (15 mg·kg^-1 body weight) subcutaneously daily for four weeks. The ratio of heart weight to body weight (HW/BW, mg/g) were measured. DNA fragmentation of myocardia cells was determined by gel electrophoresis, and caspase-3 activity in myocardia cells was tested by flow cytometry (FCM). RESULTS: In three experiment groups, the DNA isolated from myocardial cells displayed clear ladder pattern. The HW/BW and the caspase-3 activity were increased significantly than those of control groups (P<0.01). CONCLUSIONS: Cocaine induced apoptosis in rat myocardial cells. The increase in caspase-3 activity may be the one of important pathways related to the induction of apoptosis.     

Biological characteristics of long passaging rat mesenchymal stem cells

AIM:To investigate multi-potential of rat bone marrow mesenchymal stem cells (rBMMSC) and mutation inclination, the rBMMSC were long passaged in vitro. METHODS:Cellular cycles of different passages were assayed by FACSan flow cytometry and karyotypes of passage 6, passage 25 and passage 45 were compared by G-binding analysis. RESULTS:The early passages and long-term passages all showed strong proliferation; passage 6, passage 25 and passage 45 all showed normal karyotype. CONCLUSION:Long-term culture and passage of rBMMSC still remains strong proliferation. With this capability, the mutation inclination is not enhanced.     

Expression of peroxisome proliferator-activated receptor α in rat fatty liver

AIM:To investigate the role of expression of peroxisome proliferator-activated receptor α(PPAR α) in pathogenesis of rat fatty liver.METHODS:The rats were treated with a low dose of carbon terachloride (CCl₄) and fed a high fat diet to produce fatty liver. We determined the concentrations of triglyceride (TG), total cholesterol (TC), free fatty acid (FFA) in liver and the alanine aminotransferase (ALT) activity, tumor necrosis factor-α (TNF-α), FFA in serum and the degree of hepatocytic steatosis. Total RNA of liver was extracted, and the expression of PPAR α were analyzed by semi-quantitative RT-PCR method.RESULTS:In model group, the hepatocytic PPAR α mRNA expression decreased to 0.41±0.28, compared to 1.41±0.29 in the control group (P＜0.01). The contents of TG, TC, FFA in model rat liver were (1.88±0.20) mmol·L^-1, (11.03±1.12) mmol·L^-1 and (1 260.38±151.27) μmol·L^-1, respectively, compared to (0.53±0.10) mmol·L^-1, (1.25±0.25) mmol·L^-1 and (334.30±27.09) μmol·L^-1 in the control group (P＜0.01). The activity of ALT, concentrations of TNF-α and FFA in serum were also increased remarkably in model group.CONCLUSION:Oxidation of fatty acid and utilization of lipids in liver are affected by reducing the expression of PPAR α, which result lipid accumulation in liver.