半胱胺对成年鹅血浆中生长抑素和某些代谢激素的影响

目的:研究半胱胺(CS)对成年鹅生长抑素(SS)和某些代谢激素的影响.方法:14只装有翅静脉瘘管的成年杂交鹅(川白×太湖),经瘘管采取对照期和处理(一次性添喂100 mg/kg bw的半胱胺)后第1、3、5、7 d的血样,用RIA双抗法测定其中激素的含量.结果:实验期第1、3、5和7 d的生长抑素的含量均显著低于对照期(1.89±0.10 μg/L).促甲状腺激素较对照期(2.45±0.31 mIU/L)在第1 d显著下降21.63 %(P<0.05),第3、5 d均降低18.37%(P>0.05),第7 d基本回复正常(P>0.05). 实验期1、3、5和7 d的T4 较对照期(5.41±0.98 μg/L)显著升高(P<0.01);实验期第3 d的T3水平较对照期(1.05±0.06 μg /L)高36.19 %(P<0.01);同样,胰岛素在实验期的第5 d显著高于对照期(P<0.05).结论:CS能够降低成年鹅血液中SS含量,使T4、T3和胰岛素水平升高,提高了机体的代谢水平,同化作用加强,从而有利于生长.     

氯丙嗪对狗胰液分泌的影响

本工作在6只Соловьθв胰瘘狗(其中3只同时带有巴索夫胃瘘)上进行,向十二指肠肠腔内重复注入稀盐酸引起胰液分泌,一共作了78次实验,其主要结果如下:(一)在正常以及颈部迷走封闭与膈上迷走切断的情况下,肠内重复注酸后胰液分泌量一直维持在一个一定高度的水平;脂肪酶与胰蛋白酶活性的变化进程呈现平行关系。(二)在上述三种情况下,静脉注入氯丙嗪(1毫克/公斤)都大幅度地降低胰液分泌量达两小时以上;同时,脂肪酶与胰蛋白酶活性的平行关系发生紊乱。由此说明氯丙嗪对胰腺液体的分泌具有抑制作用,对胰酶活性的平行变化有分离作用,而且不是以迷走神经为其作用的传出途径。(三)文中讨论了氯丙嗪作用的可能机制。     

CO_2浓度升高对不同寄主植物上西花蓟马和花蓟马成虫体内消化酶活性的影响

【目的】为明确大气CO_2浓度升高对入侵昆虫西花蓟马Frankliniella occidentalis及其本地近缘种花蓟马F.intonsa的影响机制。【方法】在CO_2人工气候箱(400和800μL/L)内分别以不同的寄主植物(四季豆、茼蒿、辣椒和黄瓜)饲养西花蓟马和花蓟马3代以后,比较分析两种蓟马成虫体内消化酶(淀粉酶、胰蛋白酶和脂肪酶)活性的差异。【结果】4种寄主植物饲养的西花蓟马和花蓟马成虫体内淀粉酶活性均随着CO_2浓度的升高而降低,其中四季豆、黄瓜、辣椒和茼蒿饲养的西花蓟马成虫体内淀粉酶活性依次降低21.39%,25.33%,44.59%和42.27%;而花蓟马成虫体内淀粉酶活性则分别降低了48.79%,49.47%,38.86%和38.92%。随着CO_2浓度的升高,两种蓟马成虫体内脂肪酶和胰蛋白酶的活性均升高,其中四季豆、黄瓜和辣椒饲养的两种蓟马酶活性均显著升高(P0.05)。高CO_2浓度环境中四季豆饲养的西花蓟马脂肪酶和胰蛋白酶活性分别是对照的2.00和2.49倍,黄瓜饲养的种群其脂肪酶和胰蛋白酶活性分别是对照的2.36和2.27倍,辣椒饲养种群相应的酶活性分别是对照的3.61和3.59倍。而高CO_2浓度环境中四季豆、黄瓜和辣椒饲养的花蓟马脂肪酶活性仅分别是对照的1.76,2.18和2.69倍,胰蛋白酶活性分别为对照的1.72,2.19和2.42倍。【结论】CO_2浓度升高和寄主植物种类是影响两种蓟马成虫体内淀粉酶、胰蛋白酶和脂肪酶活性变化的重要原因,两种蓟马均能通过调节自身的酶活性来适应未来高CO_2浓度的气候环境,其中入侵种西花蓟马对环境的适应性强于本地近缘种花蓟马。     

波叶大黄多糖对胰腺五种酶的抑制作用

 本文报道波叶大黄多糖(Rheum hotaoense polysaccharide,RHP)对胰腺五种酶的抑制作用。结果表明。(1)RHP对胰蛋白酶、胰脂肪酶、胰淀粉酶、胰弹性蛋白酶和胰激肽释放酶均有很明显的抑制作用。IC_(50)分别为250μg/mL、21μg/mL、18μg/mL,189μg/mL和300μg/mL。(2)动力学研究表明,RHP对胰蛋白酶和胰脂肪酶的抑制均是非竞争性的,Km值分别为1.2×10~(-4)μmol/mL和1.2mg/mL,Ki值分别为355.0μg/mL和63.85μg/mL。(3)牛血清白蛋白(BSA)对RHP抑制胰蛋白晦和胰脂肪酶具有拮抗作用。当BSA浓度达72.0mg/mL时,对胰蛋白酶活性的恢复率为71.54％。当BSA浓度达20.0mg/mL时,对胰脂肪酶活性的恢复率为63.64％。上述结果表明,RHP对胰腺五种酶的抑制作用,可能是大黄治疗急性胰腺炎作用的生化机制之一,预示RHP在临床上将有重要应用前景。     

半胱胺对成年鹅糖和蛋白质代谢的影响

经瘘管收集 14只装有翅静脉瘘管的成年杂交鹅 (川白×太湖 )的血样作为对照 ,随后一次性添喂10 0mg/kg·bw的半胱胺 (处理 )。分别用放射免疫和分光光度等方法测定一些与糖和蛋白质代谢有关的激素和生化指标。处理后第 1、 3、 5、 7天分别收集血样。其中 ,4个检测日的血浆尿酸含量降低 ,谷丙转氨酶升高 ;第 5天和第 7天的血糖降低 ;第 5天胰岛素高于对照 ,而胰高血糖素低于对照 ,二者比值最大。这些结果暗示半胱胺促进了鹅机体的同化作用     

胰酶中镉的去除研究

综合对酶活性的影响,研究胰酶中镉的去除条件.在pH为6.0,HCA-1加入量为0.8%,树脂加入量为40 mL(胰脏投料200 g),胰脏活化时用HCA-1络合去除胰酶中的镉,其最高去除率可达54.9%,此时胰蛋白酶、胰脂肪酶、胰淀粉酶的活力几乎没有什么影响.该工艺可以很好地嵌入现有胰酶生产工艺中,几乎不增加生产步骤,具有非常好的工业应用前景.     

电离辐射降低大鼠胰淀粉酶和胰蛋白酶活性机制的一些初步分析

1.丙线照射后胰淀粉酶、胰蛋白酶活性明显降低,胰酶活性降低程度和胰腺重量有关。在一定照射剂量范围内,胰酶活性和腺重量随着照射剂量的增加而下降。2.同样剂量的丙线照射后,胰腺组织匀浆上清液中的胰酶活性无变化。3.丙线照射后胰腺腺泡由M受体激动剂氨甲酰胆碱引起的淀粉酶分泌量明显减少。4.电镜观察表明,丙线照射后大鼠胰腺腺泡内合成及分泌酶原的内质网、线粒体等超微结构紊乱,这可能是电离辐射后胰酶活性降低的主要原因。     

脓毒血症早晚期肝细胞核被膜NTPase活性及poly(A)+mRNA核浆转运的变化

目的和方法 :在盲肠结扎穿孔脓毒血症大鼠模型上 ,研究早晚期脓毒血症肝细胞核被膜核苷三磷酸酶 (NT Pase)活性及 poly(A) mRNA核浆转运的变化。结果 :脓毒血症早期NTPase活性增加而晚期活性降低 ,即早期Vmax与对照组比增加 6 2 % (ATP ,P <0 .0 5 )和 18% (GTP ,P <0 .0 5 ) ;晚期Vmax下降 2 6 % (ATP ,P <0 .0 5 )和5 6 % (GTP ,P <0 .0 5 )。脓毒血症仅晚期NTPase底物亲和力降低 ,即晚期Km与对照组比分别升高 2 6 % (ATP ,P<0 .0 5 )和 37% (GTP ,P <0 .0 5 )。脓毒血症早期 poly(A) mRNA核浆转运速率增加而晚期降低 ,即早期组 10min转运速率较对照组增加 2 7% (ATP ,P <0 .0 5 )和 30 % (GTP ,P <0 .0 5 ) ;晚期组降低 2 1% (P <0 .0 1)和 35 % (P <0 .0 1)。结论 :脓毒血症肝细胞核膜NTPase活性呈早期升高、晚期下降的双相变化与肝细胞核被膜 poly(A) mR NA核浆转运速率的早、晚期变化相平行 ,同时与脓毒血症血糖浓度的早、晚期变化相关。本实验在一定程度上解释了脓毒血症早晚期代谢双相变化发生的分子机理     

蛋白酶抑制剂对绿豆象幼虫中肠蛋白酶活性的影响

为明确蛋白酶抑制剂对绿豆象幼虫中肠蛋白酶活性的影响,采用室内人工接虫和生化测定的方法,研究了在离体条件和饲喂条件下4种蛋白酶抑制剂对绿豆象幼虫中肠蛋白酶的抑制作用,并测定了绿豆象幼虫取食不同含量的绿豆胰蛋白酶抑制剂(MBTI)的人工绿豆后,其中肠内总蛋白酶、类胰蛋白酶和类胰凝乳蛋白酶活性的变化.结果表明:在离体条件下,供试4种蛋白酶抑制剂对绿豆象幼虫总蛋白酶、类胰蛋白酶和类胰凝乳蛋白酶活性均有明显的抑制作用,且浓度越大,抑制效果越显著,其中以20μg·mL^-1的MBTI对3种酶活性的抑制效果最强,3种酶活性分别比对照降低了62.5%、41.2%和38.7%,而卵粘蛋白抑制剂(OI)抑制效果最弱.绿豆象幼虫取食含不同抑制剂的人工绿豆后,中肠内3种酶活性也均受到一定的抑制作用,取食后随龄期的延长,3种酶活性有所升高但仍显著低于对照,且以MBTI的抑制作用最强.当绿豆象幼虫取食不同含量MBTI的人工绿豆后,随MBTI含量的增加,对总蛋白酶活性和类胰蛋白酶活性的抑制作用均逐渐增强,但对类胰凝乳蛋白酶活性的抑制作用并不显著,只有当MBTI含量达20%时,对类胰凝乳蛋白酶活性才表现出明显的抑制作用.     

吗啡和纳洛酮对酸化十二指肠引起狗胰液分泌的影响

本工作用制备 Thomas 胰瘘和胃痿的5条狗进行慢性实验。实验时用0.1N 盐酸灌入十二指肠以刺激胰液分泌,并分別注射吗啡或/和纳洛酮,观察它们对胰液分泌和对胰液中碳酸氢盐和蛋白质浓度的影响。另外我们还观察了吗啡和纳洛酮对6条狗离体胰主导管紧张性的影响。结果表明:(1)吗啡抑制了胰液分泌量,对胰液中碳酸氢盐和蛋白质浓度无影响,由于分泌量减少故两者的排出量显著减少(P<0.05),(2)纳洛酮本身对胰液分泌量和碳酸氢盐及蛋白质浓度均无影响;(3)纳洛酮可以加强吗啡抑制胰液分泌的作用(P<0.01);(4)吗啡能增加狗的离体胰主导管肌条的紧张性,纳洛酮不能阻断或翻转吗啡的这一效应,相反能加强其效应。本工作表明,吗啡抑制酸化十二指肠所引起的胰碳酸氢盐和蛋白质排出量,其机制可能是吗啡刺激胰导管收缩,而纳洛酮则加强吗啡的这种抑制效应。     

Recent advances in the study of Kaposi's sarcoma-associated herpesvirus replication and pathogenesis

It has now been over twenty years since a novel herpesviral genome was identified in Kaposi's sarcoma biopsies. Since then, the cumulative research effort by molecular biologists, virologists, clinicians, and epidemiologists alike has led to the extensive characterization of this tumor virus, Kaposi's sarcoma-associated herpesvirus(KSHV; also known as human herpesvirus 8(HHV-8)), and its associated diseases. Here we review the current knowledge of KSHV biology and pathogenesis, with a particular emphasis on new and exciting advances in the field of epigenetics. We also discuss the development and practicality of various cell culture and animal model systems to study KSHV replication and pathogenesis.     

The structure, reproduction and taxonomy of Vidalia and Osmundaria (Rhodophyta, Rhodomelaceae)

Comprises species occurring mostly in subtidal habitats in tropical, subtropical and warm-temperate areas of the world. An analysis of the type species, V. spiralis (Sonder) Lamouroux ex J. Agardh, a species from Australia, establishes basic characters for distinguishing species in the genus. These characters are (1) branching patterns of thalli, (2) flat blades that may be spiralled on their axis, (3) width of the blade, (4) primary or secondary derivation of sterile and fertile branchlets and (5) position of sterile and fertile branchlets on the thalli. Application of the latter two characters provides an important basic method for separation of species into three major groups. Osmundaria , a genus known only in southern Australia, was studied in relation to Vidalia , and its separation from the Vidalia assemblage is not accepted. Species of Vidalia therefore are transferred to the older genus name, Osmundaria. Two new species, Osmundaria papenfussii and Osmundaria oliveae are described from Natal. Confusion in the usage of the epithet, Vidalia fimbriala Brown ex Turner has been clarified, and Vidalia gregaria Falkenberg, described as an epiphyte on Osmundaria pro/ifera Lamouroux, is revealed to be young branches of the host, Osmundaria prolifera.     

New or rare chromosome counts in Artemisia L. (Asteraceae, Anthemideae) and related genera from Kazakhstan

Fifteen chromosome counts of six Artemisia taxa and one species of each of the genera Brachanthemum, Hippolytia, Kaschgaria, Lepidolopsis and Turaniphytum are reported from Kazakhstan. Three of them are new reports, two are not consistent with previous counts and the remainder are confirmations of very scarce (one to four) earlier records. All the populations studied have the same basic chromosome number, x = 9, with ploidy levels ranging from 2x to 6x. Some correlations between ploidy level, morphological characters and distribution are noted.     

肝癌中HBV和HCV基因和抗原的分布及意义

采用原位分子杂交方法检测HCV RNA及HBV X基因;采用免疫组织化学方法研究HCV核心抗原,非结构区C33c抗原及HBxAg在肝细胞肝癌中的定位及分布.结果表明(1)HCV RNA、HBV X基因在肝细胞肝癌组织检出率分别为40%(55/136)和82%(112/136).HCV RNA定位于癌细胞的胞浆内,阳性细胞呈散在、灶状及弥漫分布三种形式;HBV X基因在肝癌细胞中的分布呈胞浆型、核型及核浆型,阳性细胞也呈上述三种分布形式;(2)HCV C33c抗原、核心抗原在肝细胞肝癌中的阳性率为81%(133/164)及86%(141/164).C33c抗原定位于癌细胞及肝细胞的胞浆内;核心抗原既定位于癌细胞核中,又可定位于胞浆中.C33c抗原阳性细胞以灶状分布为主;而核心抗原阳性细     

Selection with two alleles and complete dominance

For a plant selection model with frequency-independent viabilities, fertilities and selfing rates, it is shown that apart from global fixation, for certain parameter combinations a protected polymorphism and facultative fixation (either allele may become fixed according to initial frequencies) may both occur. Facultative fixation requires different selling rates for the dominant and recessive type. Protection of the polymorphism requires resource allocation for male and female function. In this connection the problem of purely genetically caused population extinction is discussed.
For general frequency dependence and regular segregation, the chances for establishment of a completely recessive gene are compared to those of a completely dominant gene. It is proven that the process of establishment of the recessive gene, despite a fitness advantage, may be considerably endangered by drift effects if random mating prevails. The recessive gene may reach the same effectivity in establishment as a dominant gene, only if the recessive homozygote mates exclusively with its own type during the period of establishment.