Glutamine synthesis in germinating seeds of Cucurbita moschata

During germination, an increase in glutamine and glutamine synthetase[L-glutamate: ammonia ligase (ADP), EC 6.3.1.2 [EC] ] occurred inthe cotyledons reaching a maximum at 4 to 6 days. The enzymehad a Km of 4.5 nun for L-glutamate, and 0.67 mu for hydroxylamine.Hydroxylamine exhibited substrate inhibition kinetics. The enzymewas inhibited by calcium ion, fluoride ion and p-hydroxymercuribenzoatebut not by EDTA, sodium ion or chloride ion. The sulf hydrylinhibition was reversed by dithiothreitol. In vivo synthesisof glutamine-¹⁴C from glutamate-¹⁴C was found to parallel theincrease in glutamine content and the in vitro glutamine synthetaseactivity during germination. ¹ Present address: Department of Biology, Mercyhurst College,Erie, Pennsylvania 16501, U.S.A. (Received June 12, 1971; )     

济南常见蝇类的种类及其季节消长的调查

本文记述了1960年5月至1961年4月在济南市市区及郊区采用臭鱼诱捕及人工不定期采集对蝇类的种类及季节消长的调查结果。济南市蝇类的种类前人先后报告共有22种, 此次调查共发现42种, 其中21种为本地区的首次记录。蝇类季节消长总的情况是:自3—11月份在室外均可捕获到蝇类, 8月为其高峰:最常见种类的高峰如下:大头金蝇、银绿蝇均在8月, 舍蝇在10月, 市蝇为8、10两个月, 格氏丽蝇则在5月。全年诱得的蝇类总数中以大头金蝇为最多(18.06％):银绿蝇次之(16.64％):再次之为舍蝇(15.49％)及市蝇(15.06％)等。不同场所诱得的蝇类中占比例最高的蝇种则各不相同;北郊厕所以大头金蝇为最多(34.6％), 北郊马厩则以舍蝇(30.94％)、市蝇(30.06％)居首位, 市区食堂、酱园及南郊垃圾堆则以银绿蝇为最多(分别为37.54％、27.11％及19.36％)。此外, 对不同场所常见蝇类组成的季节变化本文也进行了分析。     

牛乳中的免疫球蛋白与健康的研究

牛乳是日常生活中不可或缺的营养品,它含有丰富的营养物质,如酪蛋白、乳清蛋白、补体、脂肪和免疫球蛋白等。牛乳中含有的免疫球蛋白主要为IgG,IgA和IgM。其中,IgG含量最高,约为免疫球蛋白总量的80％。母牛分娩后第一天内分泌的初乳中免疫球蛋白含量最高,研究表明,其IgG的平均浓度可达59．80mg/ml。然而,第5-7天的初乳中IgG浓度已接近常乳水平,约为0．7．1．0mg/ml。这些免疫球蛋白不仅对犊牛,而且对新生儿以及普通人群的免疫系统都具有重要的作用。初生的牛犊免疫系统比较脆弱,在其免疫系统功能完善之前,从牛乳中获得免疫球蛋白成为它们抵抗微生物侵袭的重要方式。同样地,婴儿免疫系统功能也不健全,牛乳中的免疫球蛋白能在一定程度上帮助他们抵抗微生物侵袭。在成年人体内,免疫球蛋白具有多种生物活性功能,主要是识别和抵抗入侵的细菌和病毒等病原体,在增强机体的免疫能力、防止细菌和病毒入侵、活化补体、中和毒素、杀死肿瘤细胞等方面发挥着重要作用。经常饮用富含免疫球蛋白的牛乳,可以预防和治疗肠道病原菌引起的感染。牛乳的不同加工过程对其中的免疫球蛋白也有一定的影响。本文就牛乳中免疫球蛋白的成分功能以及各种处理加工过程对其含量的影响进行综述。     

ADAM19在人胎盘组织中的表达及其对滋养层细胞侵润、黏附的影响

去整合素基质金属蛋白酶19（a disintegrin and metalloproteinase 19,ADAM19）是新近发现的ADAMs（a disintegrin and metalloproteinase）家族新成员,在人胎盘组织中有较高水平的表达,但其在胎盘发生过程中母胎界面的时空表达及功能还鲜有报道.本研究首次就ADAM19在正常胎盘中的时空表达进行了研究,并以人绒毛膜癌细胞系JEG-3细胞为体外研究模型分析了ADAM19对滋养层细胞侵润和黏附的影响及其机理.研究结果显示,从空间上看,ADAM19在多种滋养层细胞中有广泛的分布,包括细胞滋养层细胞（vctb）、合体滋养层细胞（stb）和滋养层细胞柱（ct）,绒毛内毛细血管的内皮细胞等.RT-PCR和Western印迹分析显示在孕早期8,9周龄绒毛中ADAM19的表达量较高,但在26周和足月胎盘中其mRNA和蛋白水平均明显下调.在JEG-3细胞中瞬时转染ADAM19可以降低其侵润能力同时增强细胞间的黏附.研究结果提示,ADAM19可能是胎盘发生过程中非常重要的滋养层细胞功能的调节分子.     

蓝细菌断裂DNA聚合酶DnaE的体内/外反式剪接分析

蓝细菌Anabaena PCC7120的DNA聚合酶DnaE由2个断裂基因dnaENI和dnaECI编码.通过纯化它们的部分基因在大肠杆菌中的表达产物DnaENI′和DnaECI′来免疫家兔获得抗体,用于对断裂的DnaE在体内和体外的反式剪接活性进行鉴定.在体外实验中,将2个断裂的DNA聚合酶DnaENI′和DnaECI′混合,进行反应,并利用它们的抗体对反应产物进行鉴定;在体内实验中,利用以上抗体对Anabaena PCC7120细胞总蛋白进行免疫杂交分析.实验结果表明,蓝细菌AnabaenaPCC7120中断裂的2个DnaE多肽在体内和体外均能进行反式剪接.体外实验中,纯化的DnaENI′和DnaECI′的混合反应产生新的蛋白产物,既有成熟的反式剪接产物DnaEN′-,又有剪切了内含肽后的副产物DnaEN′和DnaE,且DTT的存在对剪接反应具有促进作用;此外体内实验中,在Anabaena PCC7120细胞中既能检测到完整的DnaE,也能检测到未作用的DnaENI,但未能检测到DnaECI.     

The effect of pollen competition on maintenance of variation in fertilisation ability

Pollen competition in the pistil does not only give flowering plants the possibility to reduce inbreeding but also provides an opportunity for selection of pollen traits that increase male reproductive success. An objection to the existence of selection on pollen competitive ability is that individual variation should quickly vanish if selection is strong. A balance between selection for local adaptation of sporophytes within sites and pollen flow between sites could maintain variation in pollen competitive ability. A prerequisite is that variation in male competitive ability is condition dependent, i.e., influenced by sporophytic adaptation to a patch. This further means that selection on pollen competitive ability can occur both directly on the gamethophytic level and indirectly on the sporophytic level. Our dynamic model shows that maintenance of variation in male competitive ability is more probable when differences in pollen competitive ability influence male fitness, i.e., in cases with pollen competition, than when differences in this trait only is a side effect of selection for more viable individuals. Since there is a connection between the gamethophytic and sporophytic life-phases, the incidence of pollen competition between donors should make it more probable that variability also in sporophyte fitness is preserved.     

工灰蝶属的修订（鳞翅目：灰蝶科）

工灰蝶属ＧｏｎｅｒｉｌｉａＳｈｉｒｚｕｅｔＹａｍａｍｏｔｏ为线灰蝶亚科Ｔｈｅｃｌｉｎａｅ的１个小属,目前已知４种,本文记述采自陕西秦岭的１个新种,即佩工灰蝶,并对该属各种的寄主植物及地理分布进行了总结,讨论了该属的分类地位。佩工灰蝶Ｇｏｎｅｒｉｌｉａｐｅｓｔｈｉｓ,新种（图１）♂前翅长１４．０ｍｍ,触角长５．５ｍｍ。新种与银线工灰蝶ＧｏｎｅｒｉｌｉａｔｈｅｓｐｉｓＬｅｅｃｈ相近似,主要区别为前翅正面顶角处的黑斑大,前缘黄色;缘毛黑色;翅反面底色黄褐色,较暗;雄性外生殖器抱器基部宽,颚形突镰状。正模♂,陕西省周至县,１９９４－ＶＩ－１４,王敏采。存西北农业大学昆虫博物馆。     

Human immune suppression is inducible by trichosanthin via CD8 cell—mediated pathway

Trichosanthin(Tk),a polypeptide with 249 amino acid residues isolated and purified from a Chinese medicinal herb,showed the capability of inducing abortion and was able to inhibit tumor growth and HIV replication.Owing to sequence homology of the peptide with a ribosomeinactivating protein,the downward activity of Tk was suggested to be related to its cytotoxic property.We report here,however,that Tk could exert potent inhibitory effects on human lymphoproliferative responses in vitro to allogeneic,mitogenic and soluble antigens with 50% inhibition doses ranged between 0.05 and 0.5μg／ml.The lowresponsivenesss caused by Tk was not due to toxic cytolysis.Rather,evidences suggested that,in the dose range adopted,the Tk-induced inhibition was attributable,at least in part,to immune suppression,in view of (1) Tk was more effective in the early stage of alloreactivity;(2)Suppression also occurred if responder cells were pulsetreated with Tk rather than cocultured;(3)Irradiated Tk-pulsed cells were capable of inducing suppression in a Tk-free culture;(4)Suppression could also be transferred by the supernatants of Tk-pulsed cultured cells;(5)Tk-induced immune suppression was diminished by depletion of CD8^ cells from the culture,and,finally;(6)Adding CD8^ cells back to the culture could restore the suppres sion.Thus the possibility that Tk might function as a down-regulator by immunological mechanisms in human immune responses is discussed.     

金翅夜蛾亚科的研究

近年来,我们又获得大量金翅夜蛾亚科的标本。这些标本有的是我们区系组的同志从全国各地采集的,有的是兄弟单位赠送或借给的。 标本共77,085号,我们逐一进行了外部特征的观察,每种作了雌雄生殖器的解剖研究。除前一报告已记载的相同种类外,新增加的种类有36种。如下:     

中国的广翅蜡蝉科附八新种

广翅蜡蝉科的种类,多数为害木本植物,少数为害禾本科草本植物,有的是果树、森林和农作物的害虫。但关于广翅蜡蝉科的研究,过去很不充分,我国的种类、分布与寄主关系,至今还不清楚。1935年胡经甫的昆虫名录中列入11种(包括3种同物异名),1959年《中国果树病虫志》中列了5种。 我们根据三十年来在全国各地的采集调查,和全国兄弟单位提供的标本,共鉴定出26种。本文着重记录它们的分布及其为害植物,并记载新种8种。