FGF19 as a postprandial, insulin-independent activator of hepatic protein and glycogen synthesis

Fibroblast growth factor (FGF) 19 is an enterokine synthesized and released when bile acids are taken up into the ileum. We show that FGF19 stimulates hepatic protein and glycogen synthesis but does not induce lipogenesis. The effects of FGF19 are independent of the activity of either insulin or the protein kinase Akt and, instead, are mediated through a mitogen-activated protein kinase signaling pathway that activates components of the protein translation machinery and stimulates glycogen synthase activity. Mice lacking FGF15 (the mouse FGF19 ortholog) fail to properly maintain blood concentrations of glucose and normal postprandial amounts of liver glycogen. FGF19 treatment restored the loss of glycogen in diabetic animals lacking insulin. Thus, FGF19 activates a physiologically important, insulin-independent endocrine pathway that regulates hepatic protein and glycogen metabolism.     

成纤维细胞生长因子23与慢性肾病的研究

成纤维细胞生长因子23与人类许多疾病相关,它不仅可以直接调节钙、磷代谢,而且可以间接调节甲状旁腺激素、维生素D代谢。FGF23和klotho蛋白对维持磷酸盐的浓度、血管和骨骼都具有其独特的意义。主要通过与磷酸盐对比,提出了FGF23可以独立预测慢性肾病的不利结果,最后指出FGF23抗体和其C-末端在慢性肾脏疾病的治疗上具有潜力。     

江汉平原杨树人工林连栽对林地土壤质量的影响

采用空间序列代替时间序列的方法,研究了连栽对江汉平原杨树人工林土壤理化性质、微生物数量变化及酶活性的影响.结果表明:与第1代林相比,第2代林土壤物理结构退化,土壤容重增大0.71%,土壤总孔隙度和毛管持水量分别降低0.41%和6.89%,土壤团聚体粒径分布的分形维数增大,土壤平均重量直径减小;土壤有机质、大量元素及微量元素等养分含量均有不同程度下降.连栽导致大量元素下降2.88%～12.20%,其中对N影响最大,K次之,P最小;连栽导致微量元素下降2.27%～53.37%,其中对Zn影响最大,其后依次是Cu、Fe、Mn和S;连栽对土壤微生物数量也有影响,随着连栽代数增加,土壤真菌、放线菌、细菌的数量分别下降34.38%、14.38%、56.63%;第2代林地土壤磷酸酶、脲酶、蔗糖酶、蛋白酶和过氧化氢酶较第1代林分别下降20.00%、11.54%、29.39%、50.00%和1.92%.     

Nucleotide sequence of a bovine clone encoding the angiogenic protein, basic fibroblast growth factor

Basic and acidic fibroblast growth factors (FGF's) are potent mitogens for capillary endothelial cells in vitro, stimulate angiogenesis in vivo, and may participate in tissue repair. An oligonucleotide probe for bovine basic FGF was designed from the nucleotide sequence of the amino-terminal exon of bovine acidic FGF, taking into account the 55 percent amino acid sequence homology between the two factors. With this oligonucleotide probe, a full length complementary DNA for basic FGF was isolated from bovine pituitary. Basic FGF in bovine hypothalamus was shown to be encoded by a single 5.0-kilobase messenger RNA; in a human hepatoma cell line, both 4.6- and 2.2-kilobase basic FGF messenger RNA's were present. Both growth factors seem to be synthesized with short amino-terminal extensions that are not found on the isolated forms for which the amino acid sequences have been determined. Neither basic nor acidic FGF has a classic signal peptide.     

獭兔KAP和FGF5基因的多态性与经济性状的关系

分析獭兔KAP基因和FGF5基因的多态性与经济性状的关系,为獭兔下一步的性状改良提供理论基础.利用PCR-SSCP技术对KAP基因的4个位点进行遗传变异检测,通过SPSS软件下的GLM程序分析150只獭兔KAP基因2个多态位点及FGF5基因2个多态位点不同基因型的最小二乘均值(LSM)、最小二乘效应值(LSE)及其遗传方差;通过标记位点与胴体性状和毛皮性状的遗传相关预测了选择反应.结果表明:獭兔KAP3.2位点可作为胴体深和被毛密度的标记位点,KAP6-1位点可作为獭兔体质量,胴体质量和被毛长度性状的标记基因型的标记位点,FGF5-1位点可作为体质量、胴体质量、皮质量和被毛密度的标记位点.     

菜籽粕芥子碱降压及其对血管内皮因子的影响

为考察油菜籽粕芥子碱氯化盐的降压作用及其对血管内皮因子的影响,采用动脉插管方式记录新西兰大耳白兔的收缩压、舒张压、平均动脉压研究芥子碱氯化盐的降压作用,酶联免疫吸附测定法（ELISA）检测血清中前列环素（PGI2）、血栓素A2（TXA2）、内皮素-1(ET-1)的水平,硝酸还原酶法检测血清中NO的水平。结果表明:芥子碱氯化盐在0.025~12.5 mg/kg浓度范围能够显著降低实验动物收缩压、舒张压及平均压;随其浓度增加,降压率上升,维持时间延长。ELISA实验结果表明芥子碱氯化盐对实验动物血清中PGI2、ET-1水平作用不显著,2.4 mg/kg与9.6 mg/kg芥子碱氯化盐能够显著降低血清中TXA2的水平。上述结果说明油菜籽粕芥子碱氯化盐具有显著的降压作用,其降压机制可能是通过抑制血管收缩因子TXA2的水平实现的。     

黑白花奶牛血压测定及钠钾对血压的影响

本文应用弹簧式血压计测定了144头中国黑白花奶牛尾动脉压,并就添加钠钾对血压的影响作了初步探讨。结果表明,用此型血压计测定奶牛尾动脉压是可行的;成奶牛尾动脉收缩压为137.10+16.32mmHg,舒张压为44.63±14.72mmHg;日粮添加钠钾可使血清钠钾浓度显著升高,尾动脉收缩压显著升高(P<0.05),舒张压极显著升高(P<0.01);建议改血压计气袋为梯形,以减少气袋与尾动脉接触不紧对血压值的影响。     

疏血通对慢性肺心病急性加重期患者的疗效观察

目的观察疏血通注射液对慢性肺心病急性加重期患者的疗效。方法将慢性肺心病急性加重期患者50例随机分为常规治疗组(25例)和疏血通治疗组(25例)。常规治疗组利用常规的综合治疗,疏血通治疗组在综合治疗的基础上加用疏血通治疗。入院时、治疗后第8天停止吸氧30min后均分别测动脉血气分析及血液流变学指标。结果常规治疗组疗效劣于疏血通治疗组(Hc=3.9100,P<0.05)。疏血通治疗组动脉血二氧化碳分压(PaCO2)、血液流变学指标和肺动脉平均压显著低于常规治疗组,动脉血氧分压(PaO2)高于常规治疗组,差异均有统计学意义(P<0.01)。结论疏血通可降低慢性肺心病急性加重期患者血流粘滞度及肺动脉高压,升高PaO2水平,降低PaCO2水平,提高治疗效果。     

牛脑钙调蛋白的纯化及其对小白鼠血糖的影响

以牛脑为材料利用纤维素色谱法纯化钙调蛋白，配制成有活性成分的药物，腹腔注射随机分组的小白鼠，研究钙调蛋白对小白鼠血糖的影响。结果表明，钙调蛋白对采食后小白鼠的血糖具有降低作用。     

铝钙复合作用对杉木幼苗抗氧化能力的影响

采用水培法研究了铝钙复合作用对1年生杉木幼苗叶片丙二醛(MDA)含量和超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)3种抗氧化物酶活性的影响。结果表明:高铝浓度(1.5 mmol·L~(-1))胁迫下,增加钙离子浓度可以明显降低杉木幼苗叶片MDA含量,增强SOD、CAT、POD活性,且增强效应随培养时间的延长而愈加明显;在高钙浓度(4.5 mmol·L~(-1))处理下,随着铝浓度的上升,幼苗叶片MDA含量升高,SOD、CAT活性下降,而POD活性变化却不明显。高铝浓度胁迫下杉木幼苗受毒害程度较大,而在高钙浓度下铝毒对杉木幼苗影响相对减弱;钙离子对杉木幼苗铝毒具有一定程度的缓解作用。     

Chemotransduction in the carotid body: K+ current modulated by PO2 in type I chemoreceptor cells

The ionic currents of carotid body type I cells and their possible involvement in the detection of oxygen tension (Po2) in arterial blood are unknown. The electrical properties of these cells were studied with the whole-cell patch clamp technique, and the hypothesis that ionic conductances can be altered by changes in PO2 was tested. The results show that type I cells have voltage-dependent sodium, calcium, and potassium channels. Sodium and calcium currents were unaffected by a decrease in PO2 from 150 to 10 millimeters of mercury, whereas, with the same experimental protocol, potassium currents were reversibly reduced by 25 to 50 percent. The effect of hypoxia was independent of internal adenosine triphosphate and calcium. Thus, ionic conductances, and particularly the O2-sensitive potassium current, play a key role in the transduction mechanism of arterial chemoreceptors.     

定点突变FGF21提高表达量研究

FGF21是一类具有重要糖脂代谢调节功能因子,是治疗2型糖尿病候选药物。但其在大肠杆菌中表达量低且主要以包涵体形式表达,为此根据FGF21与FGF家族同源序列差异,对FGF21进行定点突变以提高其表达量。以pSUMO-FGF21表达载体为模板,在突变位点两端设计引物,采用定点突变方法,将FGF21141位甘氨酸(G)突变为苯丙氨酸(F),构建突变FGF21表达载体pSUMO-mutFGF21;在大肠杆菌中进行表达,纯化mutFGF21蛋白。利用SDS-PAGE和Western blot鉴定分析突变蛋白,HepG2细胞糖吸收试验检测突变蛋白活性。结果成功对pSUMO-hFGF21进行突变,突变蛋白在大肠杆菌中成功表达,经SDS-PAGE分析,主要以可溶形式表达;与野生型FGF21(hFGF21)相比,表达量提高50%。Western blot表明mutFGF21可与FGF21抗体特异性反应。糖吸收试验显示mutFGF21具有与hFGF21一样生物活性并存在剂量依赖性,相比hFGF21,mutFGF21活性略有提高,说明定点突变FGF21(141位G突变为F)可显著提高FGF21表达量。     

Fibroblast growth factor receptor is a portal of cellular entry for herpes simplex virus type 1

Herpes simplex virus type 1 (HSV-1) is a ubiquitous pathogen responsible for considerable morbidity in the general population. The results presented herein establish the basic fibroblast growth factor (FGF) receptor as a means of entry of HSV-1 into vertebrate cells. Inhibitors of basic FGF binding to its receptor and competitive polypeptide antagonists of basic FGF prevented HSV-1 uptake. Chinese hamster ovary (CHO) cells that do not express FGF receptors are resistant to HSV-1 entry; however, HSV-1 uptake is dramatically increased in CHO cells transfected with a complementary DNA encoding a basic FGF receptor. The distribution of this integral membrane protein in vivo may explain the tissue and cell tropism of HSV-1.     

Common and distinct elements in cellular signaling via EGF and FGF receptors

Signaling pathways that are activated by epidermal growth factor (EGF) or fibroblast growth factor (FGF) receptors have been identified and compared (detailed Connections Maps are available at Science's Signal Transduction Knowledge Environment). Both receptors stimulate a similar complement of intracellular signaling pathways. However, whereas activated EGF receptors (EGFRs) function as the main platform for recruitment of signaling proteins, signaling through the FGF receptors (FGFRs) is mediated primarily by assembly of a multidocking protein complex. Moreover, FGFR signaling is subject to additional intracellular and extracellular control mechanisms that do not affect EGFR signaling. The differential circuitry of the intracellular networks that are activated by EGFR and FGFR may affect signal specificity and physiological responses.     

小鼠FGF9在大肠杆菌中的表达与纯化

为了建立小鼠FGF9的原核表达体系,获得纯化的FGF9重组蛋白,采用PCR技术扩增FGF9,并将其克隆入原核表达载体pET30a(+)中,经测序验证后将该重组质粒转入大肠杆菌BL21(DE3)中进行表达,采用亲和层析技术进行目的蛋白的纯化,并用Western blotting进行了免疫原性验证.测序结果显示插入到载体中的片段与FGF9的天然序列一致,在BL21(DE3)中表达出了可溶性的FGF9重组蛋白,其表达量达到总蛋白的40 %;用镍螯合亲和层析方法获得了纯度大于95 %的FGF9重组蛋白.     

铜、锌离子对凯特杏膜脂过氧化及抗氧化酶活性的影响

对不同铜、锌处理下凯特杏体内的丙二醛（MDA）含量及超氧化物歧化酶（SOD）、过氧化物酶（POD）活性的动态变化进行测定,结果表明：铜离子不利于凯特杏细胞膜的稳定,而锌离子有利于凯特杏细胞膜的稳定。     

Hypertension in the recently weaned Dahl salt-sensitive rat despite a diet deficient in sodium chloride

The Dahl rat is used as a model of hypertension that is "sensitive" to dietary salt (sodium chloride, NaCl). When dietary salt is supplemented in the Dahl rat, the arterial blood pressure of the "salt-sensitive" strain (S) becomes much greater than that of the "salt-resistant" strain (R). It has been widely reported that arterial blood pressure of the young Dahl S rat is not greater than that of the young Dahl R rat before dietary salt is supplemented. In the present study, however, mean arterial pressure directly measured in unanesthetized, unrestrained S rats was greater than in R rats, both when they had been recently weaned and for at least 10 weeks thereafter, despite their having been fed a diet frankly deficient in salt. In weanling S rats, the ratio of heart weight to body weight was also significantly greater than that in weanling R rats, suggesting that the greater blood pressure in the S rat causes cardiac hypertrophy. Thus, biologic differences demonstrated between the S rat and the R rat after weaning, including the phenomenon of salt-sensitivity, could be a consequence of, or be dependent on, an already extant difference in arterial blood pressure between the two strains.     

微囊藻毒素对家兔部分血液生理生化指标的影响

通过腹腔注射微囊藻毒素(microcystins,MCs)对家兔染毒,测定MC对家兔攻毒的LD50值,在不同时间点采样测定血液生理指标(红细胞计数、血红蛋白浓度、红细胞压积等)和血清酶(丙氨酸转氨酶、天门冬氨酸转氨酶、乳酸脱氢酶和碱性磷酸酶)活性变化.结果表明:家兔对微囊藻毒素较为敏感(对MC-LR的LD50为33μ/kg),血清酶活性变化灵敏,随着时间延长而逐渐升高,具有显著的时间效应关系,染毒动物在试验后期出现显著的正常红血球贫血病症.     

重金属铬、铜、汞经不同途径神经毒性的对比研究

[目的]探讨几种重金属通过不同的通路对小鼠行为学的影响。[方法]昆明鼠经LashleyⅢH-W水迷宫筛选后,剔除学习记忆差的小鼠,通过慢性滴鼻给药和灌胃的途径,用水迷宫、洞板、自主活动箱测定小鼠给药前后行为学的改变,并利用同步辐射技术,观察小鼠脑部的形态学改变。对通过2种给药途径所造成的神经毒性进行对比研究,探讨重金属通过不同通路对机体所造成的毒性差异及其相关机制。[结果]重铬酸钾滴鼻组用药前后洞板探索行为有明显变化（P〈0.05）,灌胃组给药前后无明显变化;几组重金属滴鼻给药组前后比较,神经系统的兴奋性有所增加,其中重铬酸钾滴鼻组和硫酸铜滴鼻组较为明显,灌胃组给药前后无明显变化;重铬酸钾滴鼻组小鼠和硫酸铜滴鼻组小鼠上台潜伏期有所增长,靶象限活动时间百分比、穿台次数减少,游泳速度有所减慢,灌胃组给药后潜伏期反有所缩短;HE染色和同步辐射观察显示,重铬酸钾滴鼻组小鼠海马部位神经元肿胀明显,空泡变性,可见胶质水肿,部分细胞坏死,并可见呈筛状的坏死灶,胞质中一些区域透光增加,灌胃组无明显改变。[结论]这几种重金属离子在较低浓度时即可通过嗅觉通路沉积于脑,并能通过嗅觉途径改变小鼠的行为学,灌胃组在此浓度时对小鼠的行为学没有较大的改变,有些金属离子可以作为微量元素参与新陈代谢,对神经系统不造成损害。