下丘脑外侧区注射TRH对大鼠胃酸分泌的影响

本文采用连续收集胃腔灌流法,观察下丘脑外侧区(LHA)注射促甲状腺激素释放激素(TRH)对大鼠胃酸分泌的影响,并分析TRH在LHA促进胃酸分泌的作用机制。结果表明:(1)LHA注射TRH(1μg)明显地刺激胃酸分泌;(2)预先向LHA注射酚妥拉明(10μg)、美多心安(5μg)及胃泌素抗体1μl(1:640)并不影响TRH的泌酸作用,如预先向LHA注射阿托品(5μg)则可消除TRH的泌酸效应;(3)垂体摘除及肾上腺切除均不影响TRH的泌酸作用;(4)隔下迷走神经切断后,LHA注入TRH的泌酸效应仍然出现,但持续时间显著缩短;腹腔交感神经节摘除后,TRH仍能促进胃酸分泌,但分泌量少而平稳。以上结果提示:LHA是TRH中枢泌酸效应的有关结构之一,其中枢机制是通过胆碱能M受体中介的,腹腔交感神经节和膈下迷走神经是TRH泌酸效应的传出途径。前者引起的泌酸反应出现较早且引起泌酸高峰,但持续时间短;后者则引起低平的持续分泌。     

刺激大鼠下丘脑室旁核激活的中脑中央灰质神经元对躯体传入的反应

电刺激大鼠下丘脑室旁核(PVH),在同侧中脑中央灰质(CG)内寻找逆行及顺行反应单位,然后观察它们对躯体感觉刺激的反应。实验结果表明:CG 及邻近网状结构内有10%(32/318)的单位呈逆行反应。逆行传导速度平均为0.37±0.24m/s(均数±标准差);推测这种CG→PVH 投射纤维属于细有髓或无髓神经纤维。这些单位分布于 CG 的腹外侧及背外侧亚核。50%(14/28)的逆行单位对坐骨(胫)神经的强电刺激和夹尾等损伤性刺激起反应,但对触毛或低强度的神经干刺激无明显反应。以上结果表明:外周躯体感觉,特别是损伤性信息传入 PVH 时,CG 是其中枢驿站之一。电刺激 PVH 还能顺行激活7.55(24/318)、抑制0.7%(2/318)的 CG 单位。有69%(18/26)的顺行反应单位对外周躯体神经强电刺激及夹尾起反应。提示 PVH 可能通过影响 CG神经元的活动而参与中枢痛觉的整合。     

荔枝蝽象卵寄生蜂——平腹小蜂体外培育研究

本文报道用人造寄主卵繁殖平腹小蜂Anastatus japonicus Ashmead^***成功的结果.筛选出最佳卵壳材料为32—36μm的聚丙烯膜,培养基为柞蚕蛹血淋巴44.4%、10%麦乳精33.3%、鸡蛋黄11.1%、尼氏盐11.1%.体外连代培养平腹小蜂的结果表明,除蛹化率(72—83%)外,各代间在寄生率(40—44%)、孵化率(94—96%)、羽化率(91—96%)、展翅率(97—99%)方面无明显的差别,且人造卵育出的各代蜂在身体大小、寿命及繁殖力方面均与柞蚕卵育出蜂基本相似或优于柞蚕卵育出蜂.筛选出的人工培养基的氨基酸种类与蓖麻蚕卵和柞蚕卵相同,但量上差异比较明显.本文还报道了平腹小蜂在人造寄主卵上的产卵过程.     

Inactivation of Giardia lamblia and Giardia canis cysts by combined and free chlorine

Free chlorine and a combined organic N-chloramine (3-chloro-4,4-dimethyl-2-oxazolidinone, compound 1) were compared for efficacy as disinfectants against an admixture of cysts of Giardia lamblia and Giardia canis in water solution under a variety of test conditions; variables were pH, temperature, and water quality. In general, compound 1 was found to reduce the giardial excystation in the solutions at lower concentration or shorter contact time at a given total chlorine concentration than did free chlorine.     

云杉核型的研究兼论云杉属的进化地位

本文分析了我国特产树种云杉Picea asperata的核型,K(2n)=24=20m+4sm,属2A类型,染色体相对长度组成为2n=24=2L+12M_2+SM_1+2S。云杉属植物(22种、变种)的核型全由臂比小于2的中部和近中着丝粒染色体构成,是较为原始的核型。根据松科各属核型的比较,作者讨论了云杉属的亲缘关系和进化地位,并得到形态学、解剖学、孢粉学、植化学、生化学及古植物学等的支持。     

Metacercarial infections of Paragonimus westermani in freshwater crabs sold in markets in Seoul

Status of metacercarial infections of Paragonimus westermani was observed in freshwater crabs, which were purchased at 3 markets in its peak season of 1990. All of 85 crabs were Eriocheir japonicus. No other species of Eriocheir were found. When crushed muscle and viscera was examined individually, the infection rate was 11.8%; and mean number of metacercariae was 2.1 per infected crab. Unless adequately cooked, freshwater crabs are still potential sources of human paragonimiasis.     

Component proteins in crude extract of adult Paragonimus westermani purified by immunoaffinity chromatography using monoclonal antibodies.

The nature of 2 component proteins in crude saline extract of adult Paragonimus westermani was investigated. By immunoaffinity chromatography using monoclonal antibodies (MAb) as ligands, the proteins were purified from the crude extract. Band 1 protein in disc-polyacrylamide gel electrophoresis (PAGE) was purified by PFCK-136 MAb. The protein, known to have molecular mass of 440 kDa, was composed of 23, 46 and 92 kDa subunits when observed by reducing SDS-PAGE and SDS-PAGE/immunoblot. This protein was originated from eggs of the worm as revealed by immunohistochemical staining with PFCK-136 Mab. Another affinity purified protein utilizing PFCK-44 MAb was the band 4 protein of 17 kDa in disc-PAGE. This was a monomer protein in reducing SDS-PAGE and SDS-PAGE/immunoblot. The protein was produced at intestinal epithelium of the worm.     

Evidence for a new Escherichia coli protein resembling a lysyl-tRNA synthetase.

The amino acid sequence deduced from the nucleotide sequence of an open reading frame adjacent to the frdA gene of Escherichia coli shows 30.5% identity with the C terminus of Escherichia coli lysyl-tRNA synthetases. The three motifs characteristic of aminoacyl-tRNA synthetases of class 2 are recognizable within this sequence.     

The kinetics of the first wave of spermatogenesis in the newborn male mouse

A combination of autoradiography and air-dried techniques was used to calculate the duration of the major meiotic stages in the first wave of spermatogenesis in the newborn mouse. The data indicated that the entry into meiosis occurred asynchronously over 2 days, and the time required for each stage and the total cycle was constant. These time intervals were nearly identical with those estimated for adult animals in the present study and by other authors.     

横脊叶蝉属一新种记述(同翅目:横脊叶蝉科)

作者在整理叶蝉标本时,发现横脊叶蝉属(Evacanthus Lepeletier and Serville,1825)一新种,现记述如下。模式标本存放在贵州农学院。 条翅横脊叶蝉 Evacanthus taenlatus 新种(图1—5) 雄虫体连翅长7.0;雌虫体长7.0,连翅长7.3毫米。头冠向前成钝圆角突出,中域凹陷,纵脊明显凸起,纵脊顶端与前缘脊成锚状相连接,横脊短,位于中前域,并与纵脊成十字形相交,头冠基域于中脊两侧各有一圆形凸起;单眼着生于头冠两侧前缘脊与侧脊相接处;颜面额唇基区扁平,中脊明显凸起,两侧有横刻痕,前唇基长大,由基部向端部逐渐收狭,末端超过下颚板端缘;触角脊明显,着生于复眼的后角处。前胸背板比头部宽,前缘弧