短尾猴（Macaca arctoides）和猕猴跟骨的功能形态研究

本文从形态描述和统计入手,对短尾猴(macaca arctoides)和猕猴的跟骨进行了比较研究。结果表明,所研究的跟骨变量无论数值大小还是几何图形结构都存在一定差异。特别是跟骨最大宽、跟长、后距骨连结面长、跟骨高度及相对跟长存在显著性差异水平。猕猴跟骨变量间的相关关系比短尾猴的表现得更为紧密。据其形态与功能的关系,我们认为:与猕猴相较,短尾猴更适应于地栖生活。这似乎与短尾猴具更大的体重有关。     

Monoclonal antibody AA4, which inhibits binding of IgE to high affinity receptors on rat basophilic leukemia cells, binds to novel alpha-galactosyl derivatives of ganglioside GD1b

Mouse monoclonal antibody AA4 inhibits the binding of IgE to high affinity IgE receptors on the rat basophilic leukemia cell line RBL-2H3. As shown by immunostaining of thin layer chromatograms, antibody AA4 binds avidly to two disialogangliosides (antigen I and antigen II) that occur in this cell line. The two antigens were purified by anion exchange chromatography followed by short-bed continuous thin-layer chromatography. About 230 micrograms of antigen I and 60 micrograms of antigen II were obtained from 20 g (wet weight) of leukemia cells. The structures of both purified antigens were determined to be alpha-galactosyl derivatives of the ganglioside GD1b by fast atom bombardment-mass spectrometry, by chemical ionization-mass spectrometry of permethylated samples, by gas chromatography-mass spectrometry of partially methylated alditol acetates, and by treatment with exoglycosidases and mild acid hydrolysis. The structure of antigen I is: (formula; see text) Antigen II has an additional alpha-galactosyl residue as follows: (formula; see text) The ceramide of antigen I contains approximately equal amounts of C24:0, C22:0, C20:0, C18:0, and C16:0 N-acyl fatty acids. The ceramide base is predominantly sphingosine along with a small amount of dihydrosphingosine. In contrast, the ceramide of antigen II contains mainly C24:0 N-acyl fatty acid with much lower amounts of C22:0, C20:0, and C18:0 fatty acids. Moreover, the ceramide base is approximately 55% sphingosine and 45% dihydrosphingosine. No unsaturated N-acyl fatty acids were detected in either antigen.     

Purification and Characterization of an Extracellular Acid Proteinase from the Ectomycorrhizal Fungus Hebeloma crustuliniforme

Hebeloma crustuliniforme produced an extracellular acid proteinase in a liquid medium containing bovine serum albumin as the sole nitrogen source. The proteinase was purified 26-fold with 20% activity recovery and was shown to have a molecular weight of 37,800 (as indicated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis) and an isoelectric point of 4.8 +/- 0.2. The enzyme was most active at 50 degrees C and pH 2.5 against bovine serum albumin and was stable in the absence of substrates at temperatures up to 45 degrees C and pHs between 2.0 and 5.0. Pepstatin A, diazoacetyl-dl-norleucine methylester, metallic ions Fe and Fe, and phenolic acids severely inhibited the enzyme activity, while antipain, leupeptin, N-alpha-p-tosyl-l-lysine chloromethyl ketone, and trypsin inhibitor inhibited the activity moderately. The proteinase hydrolyzed bovine serum albumin and cytochrome c rapidly compared with casein and azocasein but failed to hydrolyze any of the low-molecular-weight peptide derivatives tested.     

The changes of histopathology and serum anti-sparganum IgG in experimental sparganosis of mice

The present study is intended to observe the chronologic changes of experimental sparganosis by histopathological observation and detection of circulating anti-sparganum IgG antibody using ELISA. Each of 25 mice was infected with five spargana, and they were examined after 1, 2, 4, 10 weeks or 6 months from infection. The followings are summarized results. 1. The plerocercoids were detected in the subcutaneous tissue of the trunk, neck or axilla, but a few often extended into the skeletal muscle. The recovery rates were 72% at the first week, 80% at the second week, 95% at the fourth week, 92% at the tenth week and 100% at the sixth month. The larvae grew slowly in both length and weight until 6 months. 2. Histopathologically, most of the larvae were observed alive in the soft tissue or skeletal muscle. Numerous eosinophils, neutrophils, lymphocytes and plasma cells were infiltrated focally around the worms by the second week, but they surrounded the worms to form a layer of inflammatory reaction after 4 weeks of infection. Also histiocytes and fibroblasts began to appear around the inflammatory cells at 4 weeks. After 10 weeks, the worms encircled by a thin fibrous layer were found. After 6 months, the worms were surrounded by either fibrous tissue or active inflammatory cells. The inflammation looked more severe in the tracks left by the worms, rather than around the worms. 3. The level of anti-sparganum IgG antibody in the serum showed an increase by the fourth week, and a rapid and continuous increase was observed thereafter by the tenth week after infection.(ABSTRACT TRUNCATED AT 250 WORDS)     

The effects of gamma irradiation on the survival and development of Clonorchis sinensis metacercariae

The effects of gamma irradiation on the survival and development of C. sinensis metacercariae were studied to evaluate the feasibility of irradiation as a control measure for clonorchiasis. Pseudorasbora parva were collected at an endemic river of clonorchiasis and were used for irradiation of the fluke in three schemes. The first (Scheme 1) was irradiation of the isolated metacercariae from the fish followed by infection to experimental rats. The second (Scheme 2) was irradiation of the fish, and then the metacercariae were isolated and infected to rats. The third (Scheme 3) was irradiation on the rat livers after infection with normal metacercariae. Irradiation doses varied from 5 to 100 Gy for Schemes 1 and 2, and 10 to 25 Gy for Scheme 3. The rats were sacrificed 2 to 6 weeks after infection. In Scheme 1, the metacercariae irradiated at 50 Gy failed to survive in the rats after 2 or 6 weeks. However, 1 to 44% of the metacercariae irradiated at 5-30 Gy survived. The estimated LD50 of Scheme 1 was 16.5 Gy. The flukes irradiated in Scheme 2 survived better than those in Scheme 1. The average worm recovery rate in 50 Gy was 28%(7-39% individually). Increasing the dose up to 100 Gy brought a remarkably low survival rate of an average 1%(0-3% individually). The LD50 of Scheme 2 was 47.5 Gy. Worm recovery rates in the 10 Gy group of Scheme 3 were 21-39%, and those in the 25 Gy group were 2% and 34%. Although the metacercariae were irradiated, all of the recovered worms were morphologically normal.(ABSTRACT TRUNCATED AT 250 WORDS)     

Identification of amino acid residues of rat angiotensin II receptor for ligand binding by site directed mutagenesis.

To determine the specific mechanism of ligand binding to angiotensin (Ang II) receptor AT1, mutagenized rat receptor cDNAs were expressed transiently in COS-7 cells and the effect of the mutations on the binding to peptidic and non-peptidic ligands was analyzed by Scatchard plots. Mutation of Lys199 to Gln in the intramembrane domain strongly reduced the affinity to both [125I] Ang II and [125I]-1Sar, 8Ile-Ang II whereas mutation of two other Lys had little effect, indicating involvement of Lys199 in binding ligands. Replacement of each of four Cys in the extracellular domain markedly reduced binding affinity, indicating the importance of two putative disulfide bridges in the formation of active receptor conformation. Substitution of Asp for Asn in N-glycosylation had no effect on ligand binding or expression of the receptor. These studies indicate mutated receptors are expressed in the plasma membrane and are amenable for further detailed studies.     

西双版纳热带季节雨林植物种类多样性的一种研究方法

一、方法1.样地的选择样地分别选取热带干性季节雨林的典型代表——以箭毒木(Antiaris toxicaria)、龙果(Pouteria grandifolia)为标志的群落,以千果榄仁(Terminalia myriocarpa)、番龙眼     

分离蓝藻原生质球的新方法：青霉素－溶菌酶法

蓝藻原生质球(体)的研究,至今尚未取得决定性突破,成为细胞壁生物之中的唯一例外。这不仅表现在原生质球(体)的再生没有成功,而且分离制备方法亦存在很大问题。从1967年沿用至今的Crespi-Biggins溶菌酶法不仅在质量上不能得到真正理想的原生质球,而且数量上也达不到。由于在分离过程中细胞大量破裂,原生质球的产率很     

中华猕猴桃胚乳植株后代的观察

对438株定植的中华猕猴桃胚乳培.养的试管苗,经四年的田间观察,并进行连续二年结果分析。与对照的母株相比,胚乳植株在株形、叶片大小、果实形态及果实的主要营养成分含量上都有较大的变化。同时还发现,由同一块愈伤组织诱导的胚乳试管苗后代中也有雌、雄性别的分化。胚乳植株后代的多样性,可为中华猕猴桃的选种及品种繁育提供丰富的材料。