Association of polymorphism of Fc receptor γ chain gene at position-29 in promoter with the susceptibility to systemic lupus erythematosus in southern Chinese

AIM:To detect the association between the polymorphism of Fc receptor γ chain gene at position-29 in promoter and systemic lupus erythematosus(SLE).METHODS:The genotypes at position -29 in promoter of Fc receptor γ chain gene were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method in 180 patients with SLE and 140 ethnically matched controls in southern China.RESULTS:The frequencies of TT genotype(33.3%) and T allele (54.4%) at position -29 in patients with SLE were significantly higher than those in controls (17.2% and 42.9%, respectively), whereas, the frequencies of GG genotype (24.4%) and G allele (45.6%) in patients with SLE were remarkably lower than those in controls (31.4% and 57.1%, respectively) (P＜0.05). The TT genotype and T allele at position -29 were not associated with lupus nephritis in SLE patients (P＞0.05).CONCLUSION:Our results indicate that the T allele at position -29 in promoter of Fc receptor gene probably contributes to the susceptibility to SLE, but does not play a role in the occurrence of lupus nephritis.     

The mechanism of neuronal injury and repair after focal cerebral ischemia

AIM:To explore the mechanism of neuronal injury and repair by investigating the expression of caspase-3 and apurinic/apyrimidinic endonuclease (APE/Ref-1) after focal cerebral ischemia. METHODS:A model of middle cerebral artery occlusion in rats was performed. The expression of caspase-3P₂₀ and APE/Ref-1 was examined by immunohistochemistry staining, TUNEL was applied to detected DNA damage, and double labeling with TUNEL and APE/Ref-1 was used to determine the relationship between APE/Ref-1 and DNA damage. RESULTS:The active subunit P₂₀ of caspase-3 was predominantly expressed within ischemic penumbra. The peak time of caspase-3P₂₀ positive cells preceded the appearance of TUNEL. With aggravation of cerebral ischemia, APE/Ref-1 immunoreactive cells in penumbra were significantly decreased. CONCLUSION:The activation of caspase enzymatic cascade following cerebral ischemia leads to degradation in DNA, meanwhile, decrease in DNA repair molecules or the failure of DNA repair may deteriorate the course.     

Relationship between the intracellular calcium concentration changes and left ventricular hypertrophy and function in the spontaneously hypertensive rats

AIM:To elucidate the relationship between the intracellular calcium concentration changes and left ventricular hypertrophy and function in the spontaneously hypertensive rats (SHR).METHODS:Intracellular free calcium concentrations were measured by Fura 2 methodology and left ventricular function quantitated by cardiac catheterization in 20 SHR aged 10, 22, and 34 weeks and 20 age-matched Wistar-kyoto (WKY) rats.RESULTS:(1) The systolic blood pressure(SBP), intracellular calcium concentrations and left ventricular mass / body weight index (LVM/BW) were significantly higher in all three age groups of SHR than the corresponding groups of WKY; (2) Compared with age-matched WKY groups, the peak left ventricular pressure descending rate(-dp／dt_max) decreased while left ventricular relaxation time constant (τ)increased significantly in SHR aged 22 and 34 weeks. The peak left ventricular pressure ascending rate(dp／dt_max) and the left ventricular contractility index were significantly increased only in the 34 weeks SHR; (3) Intracellular calcium concentrations showed a positive correlation with LVM/BW,SBP,-dp／dt_max and τ(r=0.47-0.83,P<0.01)and a negative correlation with dp／dt_max and the left ventricular contractility index (r=-0.46,P<0.05 and r=-0.81, P<0.01).CONCLUSION:Intracellular calcium overload is one of the potential mechanisms in the induction of left ventricular hypertrophy as well as of systolic and diastolic dysfunction.     

Effects of matrix metalloproteinases on ventricular remodelingfollowing myocardial ischemia in the rat

AIM:To examine the relationship between the activity of matrix metallproteinases(MMPs) and ventricular remodeling following myocardial ischemia in the rat.METHODS:The model of myocardial ischemia(MI) in the rat was established by isoprenaline(ISP). The activity of MMPs was measured by zymography and collagen concentration was assessed by the method of chloramine T, so did I/III collagen ratio by immunohistochemical staining. The microstructure of myocardium was also observed by electron microscope.RESULTS:The activity of MMP-2 in myocardial ischemia group (group M) increased by 5.8 folds at 1 st week(P＜0.01), 2.3 folds at 2 nd week(P＜0.01) and 1.7 flods at 4 th week(P＜0.05) compared with control group (group C) and MMP-9's activity in group M increased by 4.9 folds (P＜0.01), 1.9 flods(P＜0.01) and 1.4 folds(P＜0.05), respectively. Collagen amount and I/III collagen ratio in group M increased compared with that in group C at 2 nd week and 4 th week. It showed that cardiac myocytes in group M were necrosed and collagen grew abundantly in interstitium under electron microscope.CONCLUSION:The activity of MMPs in the myocardial interstitium increased following myocardial ischemia, then collagen amount and I/III collagen ratio increased, which may be the major causes of ventricular remodeling.     

Role of p38MAPK in production of pro-inflammatory cytokines in Kupffer cells from severe acute pancreatitis rats

AIM:To investigate the role of p38 mitogen-activated protein kinase (p38MAPK) signaling pathway in the Kupffer cells (KCs) production of pro-inflammatory cytokines, tumor necrosis factor-α(TNF-α) and interleukin-1β(IL-1β), in severe acute pancreatitis (SAP) rats.METHODS:Sprague-Dwaley rats were randomized into three groups:①sham operation rats, ②SAP rats, ③SAP rats given the p38 MAPK inhibitor CNI-1493(10 mg/kg, iv). The SAP model was induced by the bili-pancreatic duct infusion with 5% sterile soduim taurocholate solution. Rats from each group were killed at 12 h after sham operation or SAP and Kupffer cells (KCs) were isolated. The mRNA expressions of TNF-α and IL-1β (by quantitative real-time RT-PCR) and p38 MAPK activity (by Western blot analysis) in KCs were examined. The levels of TNF-α and IL-1β in plasma were determined by ELISA.RESULTS:There was a significant acvitation of p38 MAPK in KCs harvested from SAP rats than those from sham operation rats. SAP also promoted the mRNA expressions of TNF-α and IL-1β in KCs and the plasma levels of TNF-α and IL-1β. These events were significantly inhibited by treatment with CNI-1493.CONCLUSIONS:p38 MAPK activation is one important aspect of the signaling events that may mediate the KCs production of pro-inflammatory cytokines, TNF-α and IL-1β, in SAP rats. The inhibition of the p38 MAPK may be a potential target in the prevention and treatment of SAP.     

Effects of the juice of Fructus Hippophae (JFH) on thrombocytopenia induced by cyclophosphamide in rats

AIM:To investigate the effects of the juice of fructus hippophae(JFH) on thrombocytopenia in rats.METHODS:Forty-eight wistar rats were divided into control group, model group, Yixuesheng-Jiaonang (YSJN) group and JFH group. Rats were injected intraperitoneally with cyclophosphamide (CTX, 30 mg/kg) or saline once a day for 3 days. And then, Saline, YSJN or JFH was administered (ig) once a day for 11 days. On the second, fouth, sixth and eighth day, the thrombocyte were counted, the mean platelet volume (MPV) and PDW were examined. On the eighth day, the cAMP, cGMP in platelets and platelet aggregation function were also examined.RESULTS:JFH could shorten the time of blood coagulation, increase the count of platelet, and enhance the platelet aggregation function. The experiment also showed that the JFH could decrease cGMP content in platelet.CONCLUSION:JFH could enhance blood coagulation and quality of platelet and prevent thrombocytopenia induced by cyclophosphamide in rats.     

不同地下水位植物蒸腾耗水特性研究

在甘肃省民勤治沙站利用非称量测渗仪研究了梭梭、柠条等 10种沙区植物的蒸腾耗水特征。结果表明 ,各种植物 5a的总蒸腾量由大到小排列为 :沙枣、花棒、沙木蓼、柠条、梭梭、白皮沙拐枣 ;随植物年龄增长 ,蒸腾系数有上升的趋势 ,而蒸散系数有下降的趋势 ;在民勤沙区 6～ 9月是主要蒸腾季节 ,该时段的蒸腾量占全年蒸腾量的80 %～ 90 % ;植物的蒸腾量随年龄的增长而迅速增加 ,但增长幅度随物种不同而异。一般生长快的植物增长快 ,生长慢的植物增长慢。     

Effect of Liucha extract on tumor K562 cell growth

AIM:To investigate the effects of Liucha extract on the growth of tumor cells in vitro and its possible mechanism.METHODS:The capability of colony forming of human leukemia K562 cell in vitro and the cells metabolism were studied by semi-solid agar culture and MTT staining. Then , the changes in morphology in the tumor cells were examined using electronic microscope.RESULTS:Semi-solid agar culture and MTT colorimetric analysis showed that Liucha extrats could significantly inhibit the growth of the tumor cells and their capability of colony forming. Also,under the electronic microscope,it was found that the tumor K562 cell had a narrower perinuclear space,condensation of chromatin and an enlarged mitochondria , in which the cristase disappeared.CONCLUSION:The extract from Liucha possesses an inhibitory effect on K562 cell growth in vitro through affecting the metabolism of the tumor cells.     

Effect of CGRP on level of lung endogenous NO in rabbits with acute lung injury

AIM:To examine whether calcitonin gene-related peptide (CGRP) enhances nitric oxide (NO) level in pulmonary circulation blood and observe the influence of CGRP on mean pulmonary artery pressure (mPAP) in rabbits with acute lung injury (ALI) caused by oleic acid.METHODS: The level of NO was assessed by measuring the presence of nitrite in cervical artery blood by the Griess reaction, mPAP was measured with right ventricular catheter.RESULTS:The level of nitrite in cervical artery blood was significantly increased and the mPAP was markedly reduced after administration of CGRP intravenousely.CONCLUSION:CGRP enhanced the NO level of pulmonary circulation blood and reduces the mPAP significantly in rabbits with ALI.     

Construction and identification of recombinant adenovirus vector containing CTLA4Ig gene

AIM:To construct a recombinant adenovirus expression vector containing CTLA4Ig gene.METHODS:The CTLA4Ig gene derived from the plasmid PCDNA3.0/CTLA4Ig by using polymerase chain reaction (PCR) was inserted into the backward position of cytomegalovirus (CMV) immediate early promoter of the shuttle plasmid (pAdTrack-CMV). After being identified by endonuclease, PCR and sequencing, the recombinant shuttle plasmid pAdTrack-CTLA4Ig was co-transformed into E.coli. BJ5183 cells with the adeoviral backbone plasmid pAdEasyl-1 to obtain the homologous recombination. The adenovirus was generated in 293 cells. A series methods such as PCR and fluorescence microscope was employed to identify the generated recombinant adenovirus.RESULTS:Recombinant CTLA4Ig adenoviruses were constructed and the titer of virus was generally up to 1.65×10¹² phaque forming units per liter (PFU/L).CONCLUSION:Success in constructing recombinant pAdTrack-CTLA4Ig will be the base of the further research on its expression in the mammalian cells, and be potenially used in the prevention of transplant rejection and autoimmunity diseases.