眼镜王蛇蛇毒的柱层析分离及神经毒组份的研究

用羧甲基葡聚糖C—25和氯化钠直线梯度洗脱方法,对我国广西产眼镜王蛇蛇毒进行了柱层析分离,获得了17个蛋白峰,测定了17个蛋白峰的毒性和生理活性。结果表明有7个毒性峰,其中6个峰具有阻断神经—肌肉接头传递的作用,另一个峰毒性很小,在相同剂量下也不表现上述作用。     

电子显微镜下观察眼镜王蛇毒对小白鼠心肝肾的影响

眼镜王蛇是当今排毒量最大,最毒的一种蛇类,是含神经毒素、血液毒素、细胞毒素,心脏毒素等多种混合毒类的毒蛇,使人致死率很高。关于眼镜王蛇毒致实质性器官组织超微变化的实验,国内至今仍未见有报道。本实验通过给小白鼠注射眼镜王蛇毒致死后,观察小白鼠实质性器官的组织微细结构的改变。     

青龙蛇药抗蛇毒中毒的实验研究

本文总结对青龙蛇药抗蛇毒中毒作用进行研究的买验结果,经动物实验证明,青龙蛇药口服对眼镜蛇毒、眼镜王蛇毒、五毒蛇毒及蝮蛇毒中毒的小白鼠有明显的保护作用,而对银环蛇毒中毒的保护率很低;还证明该药有对抗蛇毒的出血毒性、溶血毒性、毛细血管损伤及组织坏死的作用。     

实验证明三种蛇毒有抗癌作用

中国科学院昆明动物研究所的研究人员近年来将眼镜蜿科的蛇毒对腹水癌细胞的作用进行研究,经过动物体外试验、体内试验和接种率试验观察发现,眼镜王蛇毒、眼镜蛇毒、金环蛇毒有抗癌作用,其中以眼镜王蛇毒、金环蛇毒和金环蛇毒细胞毒素抗癌作用最强,     

普通离子交换剂用于HPLC柱层析法快速分离眼镜王蛇毒

目的　为了经济快速分离眼镜王蛇(Ophiophagushannah,Oh)蛇毒中的毒素成分。　方法　用普通离子交换剂于高效液相色谱柱 (HPLC) TSKgel SP-Toyopearl 65 0 SF (4× 1 5 0 mm)层析法 ,实验取得最佳分离条件后 ,将蛇毒样品上柱后进行梯度洗脱 ,各洗脱峰收集后在 Cosmosil 5 C4-AR-3 0 0柱 (4 .6× 1 5 0 mm)上进行逆相 HPLC分析。非单峰组分再进行 HPLC凝胶过滤柱TSKgel Toyopearl HW-40 Fine(4× 2 5 0 mm)层析 ,层析峰组分再进行 HPLC逆相分析。　结果　眼镜王蛇毒经HPLC离子交换柱层析获得了 1 6个蛋白组分 ,其中有 5个组分经逆相 HPLC分析单一组分 ;另外的复合性组分再进行 HPLC凝胶过滤柱层析后又得到 5个单峰蛋白组分。　结论　HPLC离子交换柱层析对分离蛇毒蛋白很有实用价值 ,特别是蛇毒样品量少的情况下 (1 0 ug)也能较好分离。还具有分离时间短 (1 h左右 ) ,无须低温条件等优点。HPLC凝胶过滤柱层析可进一步使蛋白组分得到提纯     

乙醇对中华眼镜蛇毒毒性的影响

目的为了探索乙醇对眼镜蛇毒毒性的影响。方法将眼镜蛇毒不同浓度致死量经不同浓度乙醇体外处理后,分别于小白鼠皮下注射、口服,将致死量蛇毒皮下注射后的小白鼠立即于局部注射乙醇,观察蛇毒毒性情况。结果小白鼠经皮下注射致死量眼镜蛇毒后,在局部注射50％（或异蛇米酒）、75％乙醇0．1～0．2ml有一定的保护作用;口服100倍皮下注射致死量眼镜蛇毒未发现有毒性表现,口服经50％乙醇处理后的眼镜蛇毒（100倍皮下注射致死量）未增加小鼠死亡率。结论眼镜蛇毒体外经过乙醇处理后毒性有所下降。口服少量的眼镜蛇毒是安全的。眼镜蛇毒与乙醇混合后口服未见蛇毒毒性增加。     

鸡卵黄抗眼镜王蛇毒抗体IgY的理化特性

目的 研制抗眼镜王蛇毒鸡卵黄抗体并研究该抗体的理化特性。方法 拟用减毒后的眼镜王蛇毒免疫母鸡后,从卵黄中制备抗眼镜王蛇毒抗体IgY。采用间接ELISA法对此抗体的理化特性进行研究。结果 ELISA显示免疫后12天开始出现特异性抗体,且抗体滴度逐渐升高,约在免疫后60天左右,最高可达1：100000,此最高滴度可维持30天,以后滴度逐渐降低,至免疫后100～110天,滴度仍可维持在最高滴度的一半(1：50000)。此抗体在10～65℃温度范围内活性保持稳定;在pH为4～12范围内,抗体活性稳定;此抗体经胰蛋白酶处理1h内,活性下降不明显,但1h以后活性迅速下降。结论从卵黄中制备抗眼镜王蛇毒抗体IgY,是可行的,稳定的。     

蛇毒丝氨蛋白酶多样性：底物专一性免疫化学及序列比较研究

本文报道烙铁头蛇毒纤维蛋白原溶酶,眼镜王蛇蛇毒纤维蛋白原溶酶,竹叶青蛇毒专一纤溶酶原激活剂对５种小分子多肽底物的底物专一性,及这些蛇毒丝氨酸蛋白酶对各种凝血因子（第Ｘ因子、凝血酶原、纤溶酶原、蛋白Ｃ）的作用,并和其它蛇毒丝氨酸蛋白酶如矛头蝮蛇毒凝血酶样酶、铜头蝮蛇毒蛋白Ｃ激活剂ＡＣＣ－Ｃ、蝰蛇毒第Ｖ因子激活剂ＲＶＶ－Ｖ进行比较研究。通过酶标偶联免疫反应研究了抗ｓｖ－ＰＡ抗体与各种丝氨酸蛋白酶的免疫     

眼镜王蛇毒柱层析分离及其组份的活性测定和L—氨基酸氧化酶的分离纯化

用ＣＭ—ＳｅｐｈａｄｅｘＣ—２５分离广西产眼镜王蛇毒,得到了１３个蛋白峰,测定了６种酶在这些峰的分布,其中７个峰有酸活性。并对含量高的Ｌ—氨基酸氧化酶进一步纯化,得到聚丙烯酰胺凝胶电泳纯一的Ｌ—氨基酸氧化酶     

广西眼镜王蛇毒酸性磷脂酶A2的肌毒性研究

目的 研究广西眼镜王蛇毒一种酸性磷脂酶A2（命名为APLA2－1）的肌毒性。方法 大鼠注射2.6mg/kg的APLA2－1后,分别于6h、24h取心肌和骨骼肌通过光镜和电镜观察它们的病理改变;或于0h、3h、6h、12h、24h取尾一胸脉血测定血清肌酶的动态变化。结果 光镜检查显示,大鼠注射APLA2－1 24h后,骨骼肌发生变性和轻度坏死,心肌无明显改变;电镜结果显示,骨骼肌在6h、24h,心肌在24h,细胞超微结构均受到不同程度的破坏;血清肌酶检测显示,注射APLA2－1后,肌酶升高显著,12h达到最大值。结论 广西眼镜王蛇毒酸性磷脂酶A2具有肌毒性,骨骼肌比心肌对其更为敏感;与别的肌毒性PLA2相比,它的毒力显得较为缓慢温和。     

Comparison of the Ribonucleic Acid Polymerases of Two Rhabdoviruses, Kern Canyon Virus and Vesicular Stomatitis Virus

A ribonucleic acid (RNA)-dependent RNA polymerase has been demonstrated in Kern Canyon virus (KCV) particles. The RNA product of the KCV polymerase hybridizes to KCV viral RNA. The properties of this viral enzyme have been characterized and compared with those of vesicular stomatitis virus (VSV). RNA polymerases from both viruses require similar conditions of temperature, pH, and detergent and magnesium concentrations for maximal synthesis of RNA. The RNA polymerase contained in the virion of KCV was more dependent on the presence of a sulfhydryl agent than was the VSV enzyme. Under optimal conditions, the specific activity of the VSV polymerase is about twenty-five times as great as that of KCV.     

Klebsiella pneumoniae survives within macrophages by avoiding delivery to lysosomes

Klebsiella pneumoniae is an important cause of community‐acquired and nosocomial pneumonia. Evidence indicates that Klebsiella might be able to persist intracellularly within a vacuolar compartment. This study was designed to investigate the interaction between Klebsiella and macrophages. Engulfment of K. pneumoniae was dependent on host cytoskeleton, cell plasma membrane lipid rafts and the activation of phosphoinositide 3‐kinase (PI3K). Microscopy studies revealed that K. pneumoniae resides within a vacuolar compartment, the Klebsiella‐containing vacuole (KCV), which traffics within vacuoles associated with the endocytic pathway. In contrast to UV‐killed bacteria, the majority of live bacteria did not co‐localize with markers of the lysosomal compartment. Our data suggest that K. pneumoniae triggers a programmed cell death in macrophages displaying features of apoptosis. Our efforts to identify the mechanism(s) whereby K. pneumoniae prevents the fusion of the lysosomes to the KCV uncovered the central role of the PI3K–Akt–Rab14 axis to control the phagosome maturation. Our data revealed that the capsule is dispensable for Klebsiella intracellular survival if bacteria were not opsonized. Furthermore, the environment found by Klebsiella within the KCV triggered the down‐regulation of the expression of cps. Altogether, this study proves evidence that K. pneumoniae survives killing by macrophages by manipulating phagosome maturation that may contribute to Klebsiella pathogenesis.     

Serological Differentiation between HCV Subtypes 1a and 1b by a Recombinant Immunoblot Assay

Until now, no serological assay has been available for the differentiation of HCV subtypes. Since there is evidence that the subtypes differently influence the clinical course of HCV infection and the outcome of interferon therapy, we established a strip immunoblot assay (NS-4 IBA) with recombinant HCV proteins of the nonstructural 4 (NS-4) region propagated in Escherichia coli. Using this NS-4 IBA, we were able to distinguish HCV subtypes la and 1b, which are the most prevalent subtypes in Europe and the U.S.A. The results of the serotyping assay were compared with those obtained by nucleotide sequencing from the NS-5 region. Concordant results were observed to match 94.9% (n = 100) by the NS-4 IBA and nucleotide sequencing. Discrepant results were obtained in only 5.1% (n = 6). These data indicate that HCV subtypes can be serologically distinguished, providing the possibility for easier identification of infection with different KCV subtypes.     

Distinguishable codon usage and amino acid composition patterns among substrates of leaderless secretory pathways from proteobacteria

The combined set of codon usage frequencies (61 sense codons) from the 111 annotated sequences of leaderless secreted type I, type III, type IV, and type VI proteins from proteobacteria were subjected to the forward and backward selection to obtain a combination of most effective predictor variables for classification/prediction purposes. The group of 24 codon frequencies displayed a strong discriminatory power with an accuracy of 100% for originally grouped and 97.3 ± 1.6% for cross-validated (LOOCV) cases and an acceptable error rate (0.062 ± 0.012) in k-fold (k = 6) cross-validation (KCV). The summary frequencies of synonymous codons for ten amino acids as the alternative predictor variables revealed a comparable discriminatory power (92.8 ± 2.5% for LOOCV), however at somewhat lower levels of prediction accuracy (0.106 ± 0.015 of KCV). A number of significant (p < 0.001) differences were found among indices of codon usage and amino acid composition depending on a definite secretion type. About 60% of secretion substrates were characterized as apparently originated from horizontal gene transfer events or putative alien genes and found to be unequally allocated in respect of groups. The proposed prediction approaches could be used to specify secretome proteins from genomic sequences as well as to assess the compatibility between bacterial secretion pathways and secretion substrates.     

Ceasing of epithelisation and deposit formation of unknown origin on the cornea.

The author presents a so far unknown pathological process interrupting permanently the regeneration of the superficially damaged cornea, and its consequences and therapy of the condition as well. The process occurs only in 5.6% of the injured individuals. The occurrence is in no correlation with the quality or extent of the damage. Also it is independent of the form and duration of therapy. The essence of the pathological changes is the slowing of corneal epithelisation within 2-4 days, followed by a complete cessation. After that a thin membrane-like layer develops simultaneously and evenly within 12 days on the area without epithelium, the surface of which is dull, transparent and whitish in colour. Within weeks or months an individually varying thickening of the membrane occurs, but the area does not grow. The surface becomes whitish-grey and is without any epithelium and with no adherence to tear. The deposits are closely and inseparably adherent to their base, their substance is rigid, being brittle only at the margins. The lesion is staining greenish-yellow with Na-fluorescein, and lively blue with toluidine blue. It is staining in small reddish-brown with rose bengal. In vivo the deposits are not measurably influenced by hyaluronidase, trypsin, alpha-chymotrypsin and papain. The microbes play no role in the process. Histological and electron-microscopical examinations suggest the corneal deposit are the product of the necrobiotic process occurring on the corneal surface during regeneration. The specific treatment consists of local application of corticoid-heparin. On the basis of the results of the examinations and literary data the author suggests that the corneal deposition and the similarly rare KCV (keratoconjunctivitis vernalis) plaque formation is the same specific process, i.e. the peculiar manifestation of the atopic state of the organism occurring independently of age.     

Functional properties of the Golgi tendon organs

Golgi tendon organs are encapsulated mechanoreceptors present at the myo-tendinous and myo-aponeurotic junctions of mammalian skeletal muscles. Within the tendon organ capsule, the terminal branches of a large diameter afferent fibre, called Ib fibre, are intertwined with collagen bundles in continuity with tendon or aponeurosis at one end. The other end is connected with a fascicle of 5-25 muscle fibres, contributed by several motor units. The contraction of these fibres, exerting strain on the collagenous bundle and causing deformation of sensory terminals, is the adequate stimulus of the tendon organ. For this stimulus, the tendon organ has a very low threshold, so that a single fibre twitch can elicit a discharge from the receptor. A tendon organ can thus signal the contraction of a single one of the 10-15 motor units which contribute fibres to the fascicle connected with the receptor. The number of tendon organs present in a muscle, taken together with the fact that a given motor unit can activate several tendon organs, strongly suggests that the contraction of every motor unit in this muscle is monitored by at least one tendon organ. The exact nature of the information provided by tendon organs to the central nervous system remains an open question because no simple relation could be established between the discharge frequency of a receptor and the contractile forces of its activating motor units. It is known, however, that, due to their dynamic sensitivity, tendon organs are efficient in signaling rapid variations of contractile force. The dynamic parameters of muscle contraction prevail in the information carried by afferent discharges from tendons organs.     

Prolongation of Life in Anephric Rats following de novo Renal Organogenesis

One solution to the shortage of human organs available for transplantation envisions growing new organs in situ. This can be accomplished by transplantation of developing organ anlagen/primordia. Allotransplantation of embryonic day 15 metanephroi into the omentum of adult hosts is followed by differentiation, growth, vascularization and function of the implants. Here we show that survival of rats with all native renal mass removed can be increased by prior metanephros transplantation and ureteroureterostomy. Excretion of urine formed by metanephroi is prerequisite for enhanced survival. This is the first demonstration that life can be extended following de novo renal organogenesis.     

RELATION BETWEEN METAMORPHOSIS AND OTHER DEVELOPMENTAL PHENOMENA IN AMPHIBIANS

1. The difference in time existing between the first shedding of the skin and the reduction of the gills to mere stubs without fringes is constant and unchangeable, which indicates that the fundamental cause for both is a common one. 2. This common cause is the action of iodine, and consequently both phenomena constitute, or at least are part of, the metamorphosis of the salamanders. 3. The development of the adult skin coloration and of the legs may take place either before or after metamorphosis. Iodine cannot enforce either of these phenomena. 4. The same is true of the development of the sex organs. 5. Development of the tongue and palatal teeth can be checked even in animals in which metamorphosis takes place. 6. Consequently development of the skin coloration, as well as development of the legs, sex organs, tongue, and palatal teeth are all caused by substances not identical with the substances causing metamorphosis and, since they are also all independent of each other in their development, it is probable that special chemical mechanisms exist for the development of each one of these six groups of organs. 7. This assumption is also supported by the fact that the order of development in several of these organ pairs can be changed by a difference in temperature, which would indicate that the development of each of these groups of organs is caused by chemical reactions with different temperature coefficients. 8. That the germ cells can develop in amphibians either before or after metamorphosis does not mean that the germ plasma is opposed as a unit to the somatic plasma, since other organs which are believed to be part of the somatic plasma behave in this respect like the germ cells. 9. The noteworthy feature of the amphibian metamorphosis is that instead of being controlled and kept in harmony by the organic individual the development of at least six groups of organs is controlled separately by the action of probably six different chemical mechanisms, each of which can be stopped or enforced independently either by directly supplying the substances required or by causing an increased formation within the body by suitable temperatures.     

Roundabout 2 regulates migration of sensory neurons by signaling in trans

BACKGROUND: Roundabout (Robo) receptors and their ligand Slit are important regulators of axon guidance and cell migration. The development of Drosophila embryonic sense organs provides a neuronal migration paradigm where the in vivo roles of Slit and Robo can be assayed using genetics. RESULTS: Here we show that Slit-Robo signaling controls migration of Drosophila larval sensory neurons that are part of the Chordotonal (Cho) stretch receptor organs. We used live imaging to show that abdominal Cho organs normally migrate ventrally during development, whereas thoracic Cho organs do not. Robo2 overexpression in cis (in the sensory neurons) or in trans (on neighboring visceral mesoderm) transforms abdominal organs to a thoracic morphology and position by blocking migration, while loss of Slit-Robo signaling produces a reverse transformation in which thoracic organs migrate ectopically. Rescue and tissue-specific knockout experiments indicate that trans signaling by Robo2 contributes to the normal positioning of the thoracic Cho organs. The differential positioning of Cho organs between the thorax and abdomen is known to be regulated by Hox genes, and we show that the essential Hox cofactor Homothorax, represses Robo2 expression in the abdominal visceral mesoderm. CONCLUSIONS: Our results suggest that segment-specific neuronal migration patterns are directed through a novel signaling complex (the "Slit sandwich") in which Robo2 on the thoracic visceral mesoderm binds to Slit and presents it to Robo receptors on Cho neurons. The differential positioning of Cho organs between thorax and abdomen may be determined by Hox gene-mediated repression of robo2.     

Fluorescence of acridine orange in the composition of blood and tissues

The interaction of acridine orange with blood albumins and tissue cells from different organs of white mouse has been studied by the spectral luminescence method. It was shown that acridine orange, by penetrating cells or organelles, is able to intercalate between base pairs in the DNA molecule. It was found that the application of acridine orange as a fluorescent probe can influence the metabolic activity of organs.