Parathyroid hormone-related protein of malignancy: active synthetic fragments

Peptides corresponding to the amino-terminal region of the parathyroid hormone-related protein (PTHrP) of humoral hypercalcemia of malignancy were synthesized. A 34-amino acid peptide, PTHrP(1-34), was two to four times more potent than bovine or human PTH(1-34) in bioassays promoting the formation of adenosine 3',5'-monophosphate (cAMP) and plasminogen activator activity in osteogenic sarcoma cells and adenylate cyclase activity in chick kidney membranes. Like parathyroid hormone itself, in which the activity resides in the first 34 residues, PTHrP peptides of less than 30 residues from the amino terminus showed substantially reduced activity. PTHrP(1-34) had only 6% of the potency of bovine PTH(1-34) in promoting bone resorption in vitro. PTHrP(1-34) strongly promoted the excretion of cAMP and phosphorus and reduced the excretion of calcium in the isolated, perfused rat kidney consistent with the symptoms seen in malignant hypercalcemia.     

A parathyroid hormone-related protein implicated in malignant hypercalcemia: cloning and expression

Humoral hypercalcemia of malignancy is a common complication of lung and certain other cancers. The hypercalcemia results from the actions of tumor factors on bone and kidney. We report here the isolation of full-length complementary DNA clones of a putative hypercalcemia factor, and the expression from the cloned DNA of the active protein in mammalian cells. The clones encode a prepro peptide of 36 amino acids and a mature protein of 141 amino acids that has significant homology with parathyroid hormone in the amino-terminal region. This previously unrecognized hormone may be important in normal as well as abnormal calcium metabolism.     

A parathyroid hormone-like protein from cultured human keratinocytes

Parathyroid hormone-like factors have been found in extracts of tumors associated with humoral hypercalcemia of malignancy, many of which are of squamous epithelial origin. Cultured, nonmalignant human keratinocytes were examined for the production of similar factors. Keratinocyte-conditioned medium from ten cultures stimulated the production of cyclic adenosine monophosphate in clonally derived rat osteosarcoma cells sensitive to parathyroid hormone. Bovine [Nle8,18, Tyr34]PTH-(3-34)NH2, a competitive inhibitor of parathyroid hormone, stopped the adenylate cyclase production stimulated by keratinocyte-conditioned medium, but antisera to parathyroid hormone had no effect on such adenylate cyclase activity. The active component of keratinocyte-conditioned medium has a molecular weight exceeding that of native parathyroid hormone. These characteristics are shared by the parathyroid hormone receptor agonists associated with humoral hypercalcemia of malignancy, which suggests that normal human keratinocytes may produce a factor related to that produced by malignant tumors associated with humoral hypercalcemia of malignancy.     

Stimulation of bone resorption in vitro by synthetic transforming growth factor-alpha

Experiments were conducted to test the hypothesis that tumor-derived transforming growth factor-alpha (TGF-alpha) is responsible for the increased bone resorption and hypercalcemia seen in some malignant diseases. Homogeneous synthetic TGF-alpha prepared by the solid-phase synthesis method stimulated bone resorption directly in vitro in a concentration-dependent manner. Incubation times of 72 hours or more were required to stimulate resorption, which is similar to the time course of bone resorption by epidermal growth factor.     

槐耳颗粒配合肺叶切除术治疗原发性支气管肺癌的临床研究

目的 研究槐耳颗粒配合胸腔镜肺叶切除术对原发性支气管肺癌患者的影响。方法 选取2013年7月-2016年7月我院及承德医学院附属医院收治的原发性支气管肺癌患者96例,采用随机数字表法分为观察组与对照组,对照组患者采用胸腔镜肺叶切除术治疗,观察组患者采用槐耳颗粒配合胸腔镜肺叶切除术治疗,对比两组患者临床疗效、高血钙发生情况、血清钙水平、胰岛素样生长因子1（IGF-1）、白细胞介素-8（IL-8）和癌胚抗原（CEA）水平。结果 观察组患者治疗总有效率100.0%,显著高于对照组87.5%（P<0.05）;治疗后两组高血钙发生率及血清钙水平较治疗前均降低（P<0.05或P<0.01）;观察组患者治疗后高血钙发生率2.1%显著低于对照组18.8%（P<0.01）,血清钙水平明显低于对照组（P<0.05）;两组患者治疗后IGF-1、IL-8和CEA水平均明显低于治疗前（P<0.01）,且观察组显著低于对照组（P<0.01）。结论 槐耳颗粒配合胸腔镜肺叶切除术能够有效提高原发性支气管肺癌患者治疗效果,降低IGF-1、血清钙、IL-8、CEA水平。     

Expression of a calcium-mobilizing parathyroid hormone-like peptide in lactating mammary tissue

A survey of rat tissues by RNA analysis, aimed at uncovering the physiological function of the parathyroid hormone-like peptide (PTH-LP) associated with hypercalcemia of malignancy, revealed the presence of a 1.5-kilobase messenger RNA encoding this peptide in lactating mammary glands. PTH-LP messenger RNA is expressed in mammary tissue only during lactation; it appears and disappears rapidly (2 to 4 hours) as a function of the sucking stimulus. The identity of this messenger RNA was confirmed by cloning the rat PTH-LP complementary DNA, which predicts a peptide with strong similarity to the human homolog. Moreover, extracts from lactating mammary tissue stimulated parathyroid hormone-dependent adenylate cyclase. These findings suggest that PTH-LP plays a physiological role in lactation, possibly as a hormone for the mobilization or transfer (or both) of calcium to the milk.     

不同钙磷水平对新扬州(蛋)鸡生产性能、蛋壳质量及骨代谢的影响

选用36周龄新扬州(蛋)鸡600只,按2×2因子安排的完全随机设计分为4组(高钙低磷组、高钙高磷组、低钙低磷组、低钙高磷组),每组5个重复,分别饲喂不同钙磷水平的玉米-豆粕型日粮,饲养42d,研究饲粮不同钙磷水平对新扬州(蛋)鸡生产性能、蛋壳质量、内分泌、胫骨质量的影响。高钙高磷组平均产蛋率显著高于两低钙组,试验期体增重显著高于其他3组(P<0.05),蛋比重、蛋壳强度、蛋壳厚度、蛋壳比例等蛋壳质量指标也均显著高于其他3组(P<0.05),高钙高磷组E2水平显著高于低钙低磷组(P<0.05),BGP、PTH、CT各组间差异不显著,各组间胫骨系数及密度差异不显著。研究结果表明,饲粮钙磷水平分别为3.5%、0.32%,二者比例约11∶1时,蛋鸡生产性能、蛋壳质量最佳,内分泌及骨代谢最为理想。     

Thyrocalcitonin: evidence for physiological function

A calcium salt given by stomach tube in modest amounts, such as might be ingested in a normal meal, produced hypercalcemia in acutely thyroidectomized fasted rats, whereas in rats with intact thyroid glands the same dose of calcium had little or no detectable effect, presumably because of release of thyrocalcitonin. Thyrocalcitonin apparently protects against hypercalcemia during feeding after deprivation.     

太湖猪种质基因特征研究

采用PCRRFLPs、PCRSSCPs和PCRDSCPs分析方法,对我国太湖猪(二花脸猪和梅山猪)18个功能基因特征进行了研究,并与大白猪进行了比较。18个功能基因是:乌头酸酶2(ACO2)、缩胆囊素肠促胰酶肽(CCK)、17β雌二醇脱氢酶(ED)、雌激素受体(ESR)、血纤维蛋白原(FGG)、生长激素(GH)、黏合素(HXB)、促黄体素释放激素受体(LHRHR)、白血病抑制因子(LIF)、莫洛尼鼠肉瘤病毒致肿瘤基因同系物(MOS)、黏病毒抗性1(MX1)、甲状旁腺激素(PTH)、磷酸葡萄糖酸脱氢酶(PGD)、维生素A结合蛋白2(RBP2)、T细胞受体α(TCRA)、T细胞受体β簇(TCRB)、转化生长因子β3(TGFB3)和甲状腺素运载蛋白(TTR)。研究结果表明,CCK、FGG、LHRHR、LIF和RBP2基因位点所扩增片段在两品种群内均呈单态性,而其他位点则呈多态性变异。太湖猪在ACO2、ED、ESR和TTR基因所扩增区域均已纯合固定,表现出保守性的一面;而在HXB、PGD和PTH位点上则出现多个等位基因,表现出变异性的一面。除在TGFB3基因位点外,太湖猪与大白猪在其他所有基因位点等位基因频率均有显著差异(P<0.01)。中国太湖猪的保守性与变异性在猪的基因定位、QTL定位及标记辅助选择中将起重要的作用。     

不同磷水平对老龄笼养蛋鸡内分泌及骨密度的影响

选用58周龄罗曼蛋鸡300只,随机分为3组,分别饲喂有效磷水平为0.35%(对照)、0.25%和0.15%的玉米-豆粕型日粮,每组5次重复,探讨日粮磷水平对老龄蛋鸡甲状旁腺素(PTH)、降钙素(CT)、雌二醇(E2)、骨钙素(BGP)及骨密度(BMD)的影响.结果显示:各组间PTH、CT 差异不显著(P＞0.05);0.15%组E2、BMD极显著低于对照组(P＜0.01);0.15%组BGP极显著高于对照组(P＜0.01).表明随日粮磷水平降低老龄蛋鸡骨质疏松发病风险增加.日粮有效磷水平为0.35%有助于延缓老龄蛋鸡骨质流失,日粮有效磷含量低于0.15%时,则会显著升高BGP、降低E2水平,且骨质流失严重.     

生物钟在蛋鸡排卵-产蛋过程中的调控作用

生物体内源性的昼夜节律使其能够预测周边环境周期性的变化,使机体的内在代谢和周边环境保持一致。在禽类卵泡的成熟、排卵和蛋的形成过程中,不同生理进程在时间上的吻合显示了机体自身以及机体与环境之间的协调统一。动物对营养物质的摄入、内分泌激素的生成、能量代谢等一系列的行为和生理过程都有生物钟参与调控。文章从光照和营养两种因素入手,综述了生物钟在神经内分泌、能量摄入和能量代谢中的调控作用,揭示了蛋鸡的排卵和产蛋机制。1.光信号通过调控生物钟影响下丘脑-垂体-性腺轴(HPG轴),从而调控机体的繁殖活动。在光信号刺激下,位于禽类视交叉上核(SCN)和松果体的中枢生物钟作用于下丘脑,使下丘脑定时性释放促性腺激素释放激素(Gn RH)和促性腺激素抑制激素(Gn IH),Gn RH和Gn IH继而作用于垂体调节释放促性腺激素-促黄体生成素(LH)和促卵泡激素(FSH),卵巢中存在的外周生物钟接受中枢的同步化信号来维持生物节律,促使禽类的卵泡成熟和定时排卵;2.除了受到HPG的神经内分泌调控之外,蛋鸡的排卵-产蛋过程还受到机体能量代谢的影响。中枢和外周的生物钟基因能够调控食欲调节系统,从而影响能量摄入;生物钟能够通过调控代谢过程中重要限速酶的表达、整合核受体和营养信号蛋白、调节代谢感受器和代谢物、影响肠道微生物等途径来调节能量代谢,影响卵黄前体物质的合成、转运和沉积;禽类松果体分泌的褪黑素可通过介导降钙素、甲状旁腺素(PTH)及雌激素分泌,节律性地调节体内钙代谢,影响蛋壳的形成。能量摄入的时间和行为、机体能量代谢和能量状态也可以通过腺苷酸活化蛋白激酶(AMPK)、过氧化物酶体增殖物激活受体α(PPARα)等一些与食欲调控和能量代谢相关的细胞因子反过来调控生物钟。营养-生物钟-能量代谢三者之间相互作用,使生物体适应环境的能力增强,能量利用达到最优。因此,通过调整进食时间和食物组分(如饲料能量水平和钙水平),能够改变能量代谢从而调节生物钟的功能。将环境(光照管理)和营养(饲喂时间、饲料配方)综合研究并加以运用,使机体生物钟成为连接外部环境信号和内部能量代谢的纽带,既能响应外界环境刺激,又能同时调控机体能量代谢进程,从而使各项生理功能得到更好地发挥,这将为蛋鸡的产蛋调控机制研究提供新的视角。     

基于水量平衡原理的畦灌下渗水形状系数变化规律研究

以往水量平衡模型应用中,通常认为在同一次灌水过程中的下渗水形状系数为恒定值,使模型精度受到一定影响。基于此,本试验以水量平衡原理为基础,结合量纲分析,研究了畦灌过程中的下渗水形状系数变化规律并提出了估算其值的经验计算式。结果表明,同一次畦灌过程中下渗水形状系数并非恒定值,而是随灌水时间和水流推进距离等因素变化的。结合已有文献资料验证,结果表明采用水量平衡模型模拟畦灌水流运动过程,同时考虑动态的地表储水形状系数和下渗水形状系数取值,可有效提高模型的计算精度。同时也表明采用本文所建经验计算式估算畦灌下渗水形状系数值是可靠的。     

碳排放约束下河南省农业全要素生产率增长与分解

传统的农业全要素生产率测算方法很少兼顾环境约束,因而无法反映出农业经济增长的真实绩效。文章采用Malmquist Luenberger指数分析了2000-2012年碳排放约束下河南省18个地市的农业全要素生产率及其分解成分。研究结果表明,碳排放约束下河南省农业全要素生产率呈增长趋势,但表现出较大的波动性,其动力主要来源于技术进步;分地区来看,河南省各地市之间农业全要素生产率差异显著,其中,豫北地区农业全要素生产率增长最高。     

转基因抗虫棉数量性状的典型相关和主成分分析

运用典型相关和主成分分析方法,对转基因抗虫棉的13个数量性状进行了研究,结果表明:转基因抗虫棉的生育性状与产量性状间典型相关极显著,产量性状与品质性状间典型相关达显著水平,生育性状与品质性状间典型相关不显著。前5个主成分因子:产量因子、品质因子、子指铃重因子、早熟因子及伸长率因子可代表一个转基因抗虫棉品种的基本特征,它们的累计贡献率达87.23%。各性状间相互联系,相互影响。在转基因抗虫棉育种中,应注意各性状间的动态平衡,有利于育成优质高产抗虫棉品种。     

Aetiology and Pathogenesis Studies on Osteoporosis in Bactrian Camel

A disease characterized by emaciation, pica, lameness and liability to fracture in bactrian camelfrom gravel desert pasture was described. Analyses of mineral elements in soil, water and forage from the af-fected and normal areas as well as in blood, hair and parts of tissues from normal and diseased camel, togetherwith a pathological study were carried out to define the nature and major causes of the disease. The relatedblood indices were also measured. The result indicated that copper and phosphorus in the soil and forage fromthe affected area were significantly lower than those of the normal area (P＜0.01). The levels of phosphorusin the blood, hair and rib reduced significantly in affected camels. The concentrations of PTH, T3, T4, creat-inine(Crt) and the activities of alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) in serum rosemarkedly (P＜0.01). Bone injury was characterized by osteoporosis. The degenerative and necrotic lesions ofliver and kidney were common. In addition, slight demylination of brains and spinal cords were showed byhistopathological and ultrastructural studies. It is concluded that the disease is caused mainly by phosphorusdeficiency in the food chain.     

气候生态因子对南昌县水稻产量的影响

通过对南昌县27年的日平均气温、积温、降水量、日照时数和实测产量进行5年滑动平均以及利用最小二乘法进行回归分析,得出气候生态因子与气象产量的关系。     

小城镇用地外延扩张的动力因素探析

处于城市化开发初期，小城镇存在着大中型城市无法获取的优惠的土地使用条件和低廉的土地价格，具有丰富的自然资源、廉价的劳动力资源和广阔的市场等，容易成为企业投资者和经营者的首选地，所以小城镇用地外延扩张十分严重。本文探讨小城镇用地外延扩张动力因素，主要来自于自然、经济、制度、科技、人文与环境等六大因素，旨在引导小城镇用地有序扩展。     

证券投资1g函数风险度量方法应用研究

将1g函数风险理论引入到证券投资领域,提出适用于中国股票市场的1g函数风险度量方法。该方法将股票收益区间均分成若干子区间,计算收益率落在各子区间中的频数求1g函数风险值。同时选取上海证券交易所股票数据对度量方法进行实证检验。检验结果表明,1g函数风险值随区间密度的增加而增长,为使1g函数风险值被限定在固定范围内,文中引入调节因子使1g函数风险值标准化,标准化后的1g函数风险值在子区间数目达到320时趋于稳定。1g函数风险度量方法能有效评估股票风险。     

农村互联网发展对中国玉米全要素生产率的影响

采用DEA-mamlquist指数测算2004—2019年中国17个玉米主产省(区)的全要素生产率,运用联立方程组模型实证检验农村互联网发展对玉米全要素生产率的影响及其作用机理,并分区域探讨其差异性。结果显示:2004—2019年中国玉米全要素生产率年均增长0.2%,主要依靠技术进步的单轨模式驱动。农村互联网的发展显著(P<0.01)提升玉米全要素生产率,主要依靠技术进步和技术效率的协同作用驱动。分区域来看,农村互联网发展对玉米全要素生产率均具有显著(P<0.01)的促进作用,其影响程度由高到低依次为北方春播玉米区>黄淮海平原夏播玉米区>西北灌溉玉米区>西南山地玉米区。建议进一步提高农村互联网的配套设施建设,发挥互联网“连接经济”的优势,应用多元化互联网技术,促进不同生态类型区玉米生产效率的提升。