柯萨奇B4病毒感染对小鼠胰岛的影响及黄芪对其保护作用

采用我国流行的CB4V亲胰腺株（P－CB4V）感染Swiss小鼠,建立Ⅰ型糖尿病的动物模型,并观察黄芪对CB4V感染引起-Ⅰ型糖尿病的保护作用。结果表明,80％的小鼠在感染后72h出现低血糖,血糖在（90．87±8．26）mg/L范围之内,6～8周全部发展为高血糖,糖刺激的胰岛素释放量在感染后72h增加,但至3～8周明显低于未感染组。在用VB4V感染小鼠的同时给予黄芪,目的在于观察黄芪对CB4V攻击胰岛β细胞的保护作用,结果经黄芪治疗后的感染小鼠,1周80％小鼠血糖在（112.66±5．0）mg／L,范围之内,60％小鼠低糖及高糖刺激的胰岛素释放量与正常对照组无差异,到3～6周全部小鼠血糖在（113．68±6．30）mg/L,范围之内,而低糖与高糖刺激的胰岛素释放量分别在（20．22±285）uIU/ml,（3640±3.05）uIU／ml范围之内,均与正常对照组无差异（P＜0.05）。     

柯萨奇B4病毒在体外对小鼠胰岛素分泌功能的影响

柯萨奇B4病毒（CB4V）感染被认为和胰岛素依赖型糖尿病（IDDM）的发病有关。我们对体外培养的小巴胰岛和胰岛细胞经CB4V感染后,检测其胰岛素分泌功能。结果显示,病毒感染组的胰岛包膜的消失较对照组早;糖刺激的胰岛素释放量明显低于对照组,但CB4V并不引起胰岛细胞的溶解。这表明：（1）CB4V可在体外感染小鼠胰岛和胰岛细胞。（2）CB4V可损害胰岛β－细胞合成胰岛素的功能。     

分别阻断β 1 和β 2 -AR对小鼠胰岛素低血糖休克的影响

分别阻断小鼠 β1 和 β2 AR后进行了加速胰岛素低血糖休克的研究。结果表明 ,对照组的休克率为 4 7 3 % ,潜伏期为 (1 64 8± 3 1 9)min ;阻断 β1 AR组的休克率增加到 74 % (P <0 0 0 5 ) ,潜伏期减少到(1 4 3 8± 4 5 6)min (P <0 0 5 ) ;阻断 β2 AR组的休克率降低到 1 5 3 % (P <0 0 0 5 ) ,潜伏期为 (1 4 9 3±4 9 1 )min (P >0 2 )。证明阻断 β1 AR可加速小鼠的胰岛素低血糖休克 ,而阻断 β2 AR反而延缓了小鼠的胰岛素低血糖休克     

丁酸梭菌影响肠炎沙门氏菌对SPF小鼠致病性的作用

【目的】旨在探究丁酸梭菌影响肠炎沙门氏菌(CVCC3377)对SPF小鼠的致病性及对小鼠的保护作用。【方法】选用72只6周龄SPF级雌性C57BL/6小鼠,按照完全随机区组设计分为阴性对照(CON)、饲喂丁酸梭菌组(CB)、沙门氏菌感染组(SE)和丁酸梭菌保护组(CB+SE)4组,每组18只。CON组和SE组饲喂基础日粮和饮水,CB组和CB+SE组饲喂基础日粮和每天更换添加丁酸梭菌(1×10⁷CFU/mL)的饮水,连续饲喂一周;第8天进行肠炎沙门氏菌感染实验,分别对SE组和CB+SE组灌服0.2mL 1.1×10⁴CFU/只的肠炎沙门氏菌,同时对阴性对照组和丁酸梭菌组灌服0.2mL生理盐水。在感染后第6天处死小鼠并采集肝脏、脾脏和盲肠及内容物样品。采用H.E染色检测肝脏和脾脏组织的病理学变化,免疫组化检测脾脏组织中TLR4、MyD88蛋白的表达水平,荧光定量PCR检测盲肠组织中TNF-α和IL-6的表达水平,并通过高通量测序方法分析其对肠道菌群的影响。【结果】结果显示,丁酸梭菌能够缓解肠炎沙门氏菌感染引起的小鼠体重下降;H.E染色结果显示,丁...     

大肠埃希菌性阴道感染小鼠模型的建立

目的 :建立大肠埃希菌定植的阴道感染小鼠模型。方法 :在阿莫西林溶液 (12 5mg/ml)冲洗小鼠阴道冲洗处理下 ,将致病性大肠埃希菌接种到小鼠阴道内。结果 :各组小鼠阴道冲洗液检出的平均对数值比较 ,经过阿莫西林溶液小鼠阴道冲洗处理后再接种大肠埃希菌的阿莫西林 +大肠埃希菌组 ,阴道内定植的大肠埃希菌数量 (8 18± 1 0 9)较经过生理盐水小鼠阴道冲洗处理后再接种大肠埃希菌组 (5 72± 0 6 8)明显增多 (P <0 0 5 ) ,而且小鼠阴道感染的症状明显 (P <0 0 5 )。结论 :通过抗生素处理后 ,再在小鼠阴道内接种大肠埃希菌 ,大肠埃希菌能够在小鼠阴道内得到定植 ,即建立起大肠埃希菌性阴道感染的小鼠模型。     

CpG ODN对呼吸道合胞病毒诱导的哮喘小鼠动物模型的免疫治疗作用

目的　探讨Cp G ODN对呼吸道合胞病毒诱导的哮喘小鼠动物模型的免疫治疗作用。方法　用紫外线灭活的呼吸道合胞病毒致敏30只BAL B/ c小鼠后,分别注射生理盐水、地塞米松和Cp G ODN,流式细胞仪检测小鼠的外周血T淋巴细胞亚群,EL ISA法检测小鼠的外周血IL - 4、IFN-γ和总Ig E的含量,并观察肺组织病理变化。结果　Cp G组CD4 +T细胞所占百分比为( 6 9.35±6 .15 ) % ,CD4 +/ CD8+的比值为2 .92±0 .35 ,与哮喘模型组相比显著降低( P<0 .0 5 )。Cp G组IL- 4的含量为( 88.96±9.89) pg/ ml,与哮喘模型组相比明显降低( P<0 .0 5 ) ;IFN-γ的含量为( 4 6 .83±8.84 ) pg/ ml,与哮喘模型组相比显著上升( P<0 .0 5 ) ;总Ig E的含量为( 3.72±0 .6 7) IU/ml,与哮喘模型组相比明显降低( P<0 .0 5 )。肺组织炎症反应明显减轻。结论　Cp G ODN对用紫外线灭活的呼吸道合胞病毒诱导的哮喘小鼠动物模型具有较好的免疫治疗作用     

BALB/c小鼠血小板抽样测试与统计分析

调查了BALB c小鼠血液血小板的正常参考值范围。随机抽样BALB c小鼠 98例 ,雄性 5 0只 ,雌性 48只 ,显微镜计数法 ,按统计学原理分析 ,并对总体正常值范围估计。结果表明 ,♂ : X±SD =3 1 7 5 8± 72 0 8,μ±S X =3 1 7 5 8± 1 0 1 9,μ的可信区间估计为 3 0 0 5 0～ 3 3 4 66(90 %可信度 )、2 97 1 1～ 3 3 8 0 5(95 %可信度 )和 2 90 2 9～ 3 44 87(99%可信度 ) ,正常值范围综合估计为 1 94 92～ 41 4 95 (含 90 %总体 )、1 80 87～ 42 5 9(含 95 %总体 )和 1 5 8 67～ 45 9 62 (含 99%总体 ) ;♀ : X±SD =2 85 2 3± 71 71 ,μ±S X =2 85 2 3± 1 0 3 5 ,μ的可信区间估计为 2 67 88～ 3 0 2 5 8(90 %可信度 )、2 64 44～ 3 0 6 0 2 (95 %可信度 )和2 5 7 5 1～ 3 1 2 95 (99%可信度 ) ,正常值范围综合估计为 1 68 64～ 3 81 3 6(含 90 %总体 )、1 5 3 5 9～ 3 93 0 1(含 95 %总体 )和 1 2 8 3 6～ 42 6 65 (含 99%总体 ) ,单位为× 1 0 9 L。性别间有差异 ,P <0 0 5。本结果可为科研、教学工作提供参考。     

隐孢子虫感染与患者免疫功能表达

目的 :探讨隐孢子虫感染与细胞免疫功能的关系。方法 :采用生物素 -链霉亲和素 ( BSA)和EL ISA法对卵囊阳性患者分别进行 T细胞亚群、膜白细胞介素 - 2受体 ( m IL - 2 R)和血清特异性 Ig G、Ig M检测。结果 :隐孢子虫卵囊阳性者 CD+3、CD+4、CD+8和 CD+4/ CD+8阳性百分率分别为 ( 6 5 .83± 6 .5 5 ) %、( 4 3.5 5± 6 .10 ) %、( 2 8.4 3± 4 .32 ) %和 1.5 8± 0 .32 ) % ,静息期与诱导期 m IL- 2 R表达水平分别为 ( 2 .92±1.0 6 ) %和 ( 33.4 5± 2 .31) % ;隐孢子虫卵囊阴性者 CD+3、CD+4、CD+8和 CD+4/ CD+8阳性百分率分别为( 5 5 .87± 7.2 3) %、( 39.2 6± 6 .4 3) %、( 30 .0 4± 5 .6 7) %和 ( 1.36± 0 .4 1) % ,静息期与诱导期 m IL- 2 R表达水平分别为 ( 4 .31± 1.4 7) %和 ( 35 .4 1± 3.12 ) % ,两者相比 ,差异有显著性 ( P<0 .0 5～ P<0 .0 1)。隐孢子虫特异性抗体 Ig G、Ig M、Ig G + Ig M阳性率分别为 6 3.4 1% ( 2 6 / 4 1)、17.0 7% ( 7/ 4 1)、19.5 1% ( 8/ 4 1) ,隐孢子虫感染后的体液免疫以 Ig G为最多见。结论 :隐孢子虫感染以细胞免疫为主 ,体液免疫在隐孢子虫感染中具有一定的局限性。隐孢子虫感染者体内存在一定程度细胞免疫功能紊乱。     

Ⅰ型干扰素受体缺失小鼠体外受精实验研究

目的探索两种I型干扰素受体缺失对于小鼠体外受精的影响并对体外受精条件进行优化。方法对两种I型干扰素受体缺失小鼠(IFN-αR-/-、IFN-α/βR-/-)及背景野生型小鼠(C57BL/6)分别进行体外受精及胚胎移植,每组超排5只小鼠,3次重复,记录相关数据,分析干扰素受体缺失是否对小鼠体外受精存在影响。分别将两种I型干扰素受体缺失小鼠配子与C57BL/6小鼠配子进行体外受精杂交试验,每组5只小鼠,3次重复,探讨I型干扰素受体缺失对雌雄配子体外受精的影响。同时,优化体外受精条件,探索提高受精率技术方法,每组5只小鼠,三次重复。结果两种I型干扰素受体缺失小鼠平均体外受精率低于背景品系C57BL/6小鼠,组间差异具有显著性(P0. 05)。干扰素α受体缺失小鼠体外受精率高于干扰素α、β受体双缺失小鼠体外受精率,组间差异具有显著性(P0. 05)。两种I型干扰素受体缺失小鼠的精子与C57BL/6小鼠卵细胞体外受精率均高于其卵细胞与C57BL/6小鼠精子的体外受精率,组间差异具有显著性(P0. 05)。通过延长精子获能时间至1 h或在获能液及受精液中加入1 mmol/L还原型谷胱甘肽(GSH)能够提高体外体外受精率,相应组间差异具有显著性(P0. 05)。结论 I型干扰素受体缺失可能导致相应品系小鼠体外受精率降低,而且对卵细胞的影响较精子的影响更为显著,通过适当延长精子获能时间或改变获能及受精液成分,能够提高体外受精率。     

草毡寒冻雏形土CO2释放特征

研究了植物生长季节海北高寒草甸生态系统高寒嵩草草甸覆被下草毡寒冻雏形土的 CO2 释放速率。其结果表明 :CO2 释放速率有明显的日变化和季节动态。日最大排放速率多出现在 1 4 :0 0～ 1 6:0 0时 ,最小排放速率在 6:0 0～ 8:0 0时。植物生长季日最大振幅为 797.75mg/m2·h,最小振幅 1 97.33mg/m2·h。CO2 排放白天大于夜晚。不同物候期 CO2 释放速率不同 ,其顺序为草盛期 >枯黄期 >返青期。生长季土壤 CO2 释放速率的范围是 4 41 .72 mg/m2 · h± 1 55.2 9mg/m2· h,最大日均值为 681 .0 6mg/m2 · h( 7月 1 6日 ) ,最低值 1 76.65mg/m2 · h ( 6月 1日 )。退化草地土壤 CO2 释放速率明显低于未退化草地 ,生长季平均日均值低 1 37.4 7mg/m2·h。相关分析表明 :土壤 CO2 排放速率与气温、地表温度、土壤5cm、1 0 cm、1 5cm、2 0 cm、30 cm地温均呈显著和极显著相关关系。温度是影响土壤 CO2 释放速率的主要因子。     

Catabolism of 4-Hydroxyacids and 4-Hydroxynonenal via 4-Hydroxy-4-phosphoacyl-CoAs

4-Hydroxyacids are products of ubiquitously occurring lipid peroxidation (C₉, C₆) or drugs of abuse (C₄, C₅). We investigated the catabolism of these compounds using a combination of metabolomics and mass isotopomer analysis. Livers were perfused with various concentrations of unlabeled and labeled saturated 4-hydroxyacids (C₄ to C₁₁) or 4-hydroxynonenal. All the compounds tested form a new class of acyl-CoA esters, 4-hydroxy-4-phosphoacyl-CoAs, characterized by liquid chromatography-tandem mass spectrometry, accurate mass spectrometry, and ³¹P-NMR. All 4-hydroxyacids with five or more carbons are metabolized by two new pathways. The first and major pathway, which involves 4-hydroxy-4-phosphoacyl-CoAs, leads in six steps to the isomerization of 4-hydroxyacyl-CoA to 3-hydroxyacyl-CoAs. The latter are intermediates of physiological β-oxidation. The second and minor pathway involves a sequence of β-oxidation, α-oxidation, and β-oxidation steps. In mice deficient in succinic semialdehyde dehydrogenase, high plasma concentrations of 4-hydroxybutyrate result in high concentrations of 4-hydroxy-4-phospho-butyryl-CoA in brain and liver. The high concentration of 4-hydroxy-4-phospho-butyryl-CoA may be related to the cerebral dysfunction of subjects ingesting 4-hydroxybutyrate and to the mental retardation of patients with 4-hydroxybutyric aciduria. Our data illustrate the potential of the combination of metabolomics and mass isotopomer analysis for pathway discovery.     

A short path to synthesis of 4-deoxy-4-fluoroglucosaminides: methylumbelliferyl N-acetyl-4-deoxy-4-fluoro-beta-D-glucosaminide

A convenient method of synthesis of 1,6-anhydro-4-deoxy-2-O-tosyl-4-fluoro-beta-D-glucopyranose by fusion of 1,6;3,4-dianhydro-2-O-tosyl-beta-D-galactopyranose with 2,4,6-trimethylpyridinium fluoride was found. By successive action of ammonia, methyl trifluoroacetate, and acetic anhydride, the resulting compound was transformed into 1,6-anhydro-3-O-acetyl-2,4-dideoxy-2-trifluoroacetamido-4-fluoro-beta-D-glucopyranose, which was converted into 3,6-di-O-acetyl-2,4-dideoxy-2-trifluoroacetamido-4-fluoro-alpha-D-glucopyranosyl fluoride by the reaction with HF/Py. The resulting fluoride was further used as a glycosyl donor in the synthesis of methylumbelliferyl N-acetyl-4-deoxy-4-fluoro-beta-D-glucosaminide.     

Structure and stability of sodium and potassium complexes of dT4G4 and dT4G4T.

The ends of eukaryotic chromosomes contain specialized structures that include DNA with multiple tandem repeats of simple sequences containing clusters of G on one strand, together with proteins which synthesize and bind to these sequences. The unit repeat in the protozoan Oxytricha with the cluster dT4G4 can form structures containing tetrads of guanine residues, referred to G4 DNA, in the presence of metal ions such as Na+ or K+. We show here that, in the presence of Na+, dT4G4 forms a tetramer with parallel strands by means of a UV cross-linking assay. In the presence of K+, two further interactions are observed: at low temperature, higher order complexes are formed, provided the 3' end of the strand is G; a single 3'T inhibits this association in dT4G4T. At high temperature, these complexes dissociate, leading to a tetramer with a different ordered structure that melts only at very high temperatures. These results suggest that the cohesive properties of DNA containing G clusters might depend on associative interactions driven by a free 3'G terminus in the presence of K+, as well as by connecting antiparallel G hairpins as has been postulated.     

Hydration pattern of A4T4 and T4A4 DNA: a molecular dynamics study

Hydration pattern and energetics of 'A-tract' containing duplexes have been studied using molecular dynamics on 12-mer self-complementary sequences 5'-d(GCA4T4GC)-3' and 5'-d(CGT4A4CG)-3'. The structural features for the simulated duplexes showed correlation with the corresponding experimental structures. Analysis of the hydration pattern confirmed that water network around the simulated duplexes is more conformation specific rather than sequence specific. The calculated heat capacity change upon duplex formation showed that the process is entropically driven for both the sequences. Furthermore, the theoretical free energy estimates calculated using MMPBSA approach showed a higher net electrostatic contribution for A4T4 duplex formation than for T4A4, however, energetically both the duplexes are observed to be equally stable.     

Non-cross-reactivity of antibodies to murine LDH-C4 with LDH-A4 and LDH-B4

The induction of infertility by immunization with the sperm-specific lactate dehydrogenase, LDH-C4, suggests its use in a contraceptive vaccine. Development of an immunological contraceptive for human use, however, requires that there be no cross-reactions with somatic tissues. We have demonstrated, using enzyme-linked immunoabsorbence, solid-phase radioimmunoassay, and competitive inhibition radioimmunoassay, that antisera to LDH-C4 is specific and does not cross-react with the somatic isozymes, LDH-A4 and LDH-B4.     

Direct interaction of Rab4 with syntaxin 4

In the present study, we examined the possible interaction between Rab4 and syntaxin 4, both having been implicated in insulin-induced GLUT4 translocation. Rab4 and syntaxin 4 were coimmunoprecipitated from the lysates of electrically permeabilized rat adipocytes. The interaction between the two proteins was reduced by insulin treatment and increased by the addition of guanosine 5'-O-(3-thiotriphosphate) (GTPgammaS). An in vitro binding assay revealed that the bacterially expressed Rab4 was bound to a glutathione S-transferase fusion protein containing the cytoplasmic domain of syntaxin 4 (GST-syntaxin 4-(1-273)) but not to syntaxin 1A or vesicle-associated membrane protein-2. The interaction between Rab4 and syntaxin 4 seemed to be regulated by the guanine nucleotide status of Rab4, because 1) GTPgammaS treatment of the cells significantly increased, but guanosine 5'-O-(2-thiodiphosphate) (GDPbetaS) treatment decreased the amount of Rab4 pulled down with GST-syntaxin 4-(1-273) from the cell lysates; 2) GTPgammaS loading on Rab4 caused a marked increase in the affinity of Rab4 to syntaxin 4 whereas GDPbetaS loading had little effect; and 3) a GTPase-deficient mutant of Rab4 (Rab4(Q67L)), but not a GTP-binding-defective mutant (Rab4(S22N)), was bound to GST-syntaxin 4-(1-273). Although insulin stimulated [gamma-(32)P]GTP binding to Rab4 in a time-dependent fashion, its effect on the Rab4 interaction with syntaxin 4 was apparently biphasic; an initial increase in Rab4 associated with syntaxin 4 was followed by a gradual dissociation of the GTPase from syntaxin 4. Finally, the binding of Rab4(Q67L) to GST-syntaxin 4-(1-273) was inhibited by munc-18c in a dose-dependent manner, indicating that GTP-loaded Rab4 binds to syntaxin 4 in the open conformation. These results suggest that 1) Rab4 interacts with syntaxin 4 in a direct and specific manner, and 2) the interaction is regulated by the guanine nucleotide status of Rab4 as well as by the conformational status of syntaxin 4.     

Eosinophil peroxidase-mediated inactivation of leukotrienes B4, C4, and D4

The slow-reacting substance (SRS) bioactivity of leukotrienes C4 (LTC4) and D4 (LTD4) was rapidly decreased by incubation with eosinophil peroxidase (EPO), H2O2, and iodide, bromide, or to a lesser degree, chloride, LTB4 chemotactic activity was also decreased by the EPO-H2-H2-halide system, although at a slower rate. Myeloperoxidase could substitute for EPO in these reactions. Leukotriene inactivation was greatly decreased or abolished by deletion of any of the components of the system or by the addition of the hemeprotein inhibitors, azide, cyanide, or aminotriazole, indicating a requirement for peroxidase. The H2O2 concentration employed in the above studies was 10(-4) M. H2O2 at higher concentrations (5 x 10(-4) to 10(-2) M) inactivated LTC4 and LTD4 in the absence of EPO and a halide but had no effect on the chemotactic activity of LTB4. We have previously shown that horse eosinophils stimulated with the calcium ionophore A23187 generate SRS. In the present study, eosinophils stimulated in this way were found to release extracellularly both H2O2 and EPO. Incubation of eosinophils with azide that inhibits EPO, and catalase that degrades H2O2, significantly increased the amount of SRS activity detected in the extracellular medium after A23187 stimulation. These findings suggests eosinophils may play an important modulating role in hypersensitivity reactions both by the production of leukotrienes and by their inactivation through the release of H2O2 and EPO.     

Macrosatellite epigenetics: the two faces of DXZ4 and D4Z4

Almost half of the human genome consists of repetitive DNA. Understanding what role these elements have in setting up chromatin states that underlie gene and chromosome function in complex genomes is paramount. The function of some types of repetitive DNA is obvious by virtue of their location, such as the alphoid arrays that define active centromeres. However, there are many other types of repetitive DNA whose evolutionary origins and current roles in genome biology remain unknown. One type of repetitive DNA that falls into this class is the macrosatellites. The relevance of these sequences to disease is clearly demonstrated by the 4q macrosatellite (D4Z4), whereupon contraction in the size of the array is associated with the onset of facioscapulohumeral muscular dystrophy. Here, I describe recent findings relating to the chromatin organization of D4Z4 and that of the X-linked macrosatellite DXZ4, highlighting the fact that these enigmatic sequences share more than a similar name.