Comparison between peroxidase-conjugated antigen or antibody and peroxidase-anti-peroxidase complex in a postembedding procedure.

The staining efficiency of peroxidase labeled immunoglobulin conjugate, used either as antigen or as antibody, has been compared with that of peroxidase-anti-peroxidase complex (PAP) on ultrathin sections of araldite embedded material. The conjugate gave positive results in a two layer method as well as in a three layer method when used as antibody. No staining was observed when it was used as antigen. The conjugation seemed to impair the antigenic reactivity of immunoglobulin. The conjugate when used as antibody in the three layer method gave approximately the same staining efficiency as PAP.     

Immunocontraception par la prévention de l’interaction gamétique

The paper summarize the main data relevant to the obtention of contraceptive vaccines based on spermatozoa as well as zona pellucida antigens. The development of novel forms of contraception is one way in which this global population problems can be tackled. The sperm as well as the oocyte antigens are studied as possible contraceptive vaccine candidates are the subject of this review.     

黑翅土白蚁纤维素酶纯化及其特性研究(英文)

利用DuoFlow层析系统阴离子交换柱UNOsphere Q,从黑翅土白蚁工蚁体内分离出内切葡聚糖酶。以羧甲基纤维素和水杨苷为底物,测得纯化酶的活性分别是原酶液的807.5和14.4倍。经变性聚丙烯酰胺凝胶电泳分析,获得单一的蛋白条带,其分子量大小为80kDa。经双向电泳图谱分析,其等电点为6.4。     

PURIFICATION AND SOME PROPERTIES OF CELLULASE FROM ODONTOTERMES FORMOSANUS (ISOPTERA: TERMITIDAE)

Abstract  The purification of the cellulase from Odontotermes formosanus workers was achieved by using anion-exchange column of UNOsphere Q, BioLogic DuoFlow chromatography system. The purified cellulase was identified as an endoglucanase and some of its properties were investigated. The EGase activity was 807.5-fold as high as the initial enzyme activity using CMC as substrate and 14.4-fold using salicin as substrate. The enzyme preparations were homogeneous as judged by SDS-PAGE electrophoresis, molecular weight of which was 80 kDa and confirmed by 2-DE zymogram analysis. The enzyme was isoelectric at pH 6.4, which was active on CMC substrate.     

The action of beta-galactosidase (Escherichia coli) on allolactose.

The parameters involved in the action of beta-galactosidase (EC 3.2.1.23) (Escherichia coli) on allolactose, the natural inducer of lac operon in E. coli, were studied. At low allolactose concentrations only galactose and glucose were formed, while at high allolactose concentrations transgalactolytic oligosaccharides were also produced. Detectable amounts of lactose were not formed. The V and Km values (49.6 U/mg and 0.00120 M, respectively) indicated that allolactose is as good if not a better substrate of beta-galactosidase as lactose. The pH optimum with allolactose (7.8-7.9) as well as its activation by K+ (as compared to activation by Na+) were similar to the case with lactose as substrate. The alpha-anomer of allolactose was hydrolyzed about two times as rapidly as was the beta-anomer.     

Advances in nonimplantable electrical stimualtors for correction of urinary incontinence.

The nonimplantable electrical stimulators are widely used as rehabilitation aids for correction of urinary incontinence. The advances in the field of the design of nonimplantable electrical stimulators such as automatic vaginal electrical stimulator VAGICON-X and anal pressure controlled electrical stimulator are described. The evaluation of VAGICON-X in patients suffering from stress and urge incontinence as well as preliminary results of acute application of anal pressure electrical stimulation in patients with stress incontinence as presented.     

Development of biochemistry in the Biology Department of Kharkhov State University. Formation of a new direction--physiology and biochemistry of aging

The article presents some data on teaching Biochemistry at the Nature Department of Kharkiv Imperial University Physico-Mathematical Faculty, as well as restoration of biochemical education and scientific researches as a result of the University reorganization in the Soviet period and foundation of the Biochemistry Chair at the Biological Faculty in the renovated Kharkiv State University. The analysis of scientific biochemical investigations conducted in the Kharkiv University till now is revealed. The special attention is paid to development of such a scientific trend as age physiology and biochemistry. The article deals with the comprehensive information on scientific and pedagogical activity of the outstanding scientists such as O. V. Nagorny and I. M. Bulankin as founders of the Kharkiv school of age physiology and biochemistry. The work has utilized some archive data.     

Crystal structure of cathepsin X: a flip-flop of the ring of His23 allows carboxy-monopeptidase and carboxy-dipeptidase activity of the protease

BACKGROUND: Cathepsin X is a widespread, abundantly expressed papain-like mammalian lysosomal cysteine protease. It exhibits carboxy-monopeptidase as well as carboxy-dipeptidase activity and shares a similar activity profile with cathepsin B. The latter has been implicated in normal physiological events as well as in various pathological states such as rheumatoid arthritis, Alzheimer's disease and cancer progression. Thus the question is raised as to which of the two enzyme activities has actually been monitored. RESULTS: The crystal structure of human cathepsin X has been determined at 2.67 A resolution. The structure shares the common features of a papain-like enzyme fold, but with a unique active site. The most pronounced feature of the cathepsin X structure is the mini-loop that includes a short three-residue insertion protruding into the active site of the protease. The residue Tyr27 on one side of the loop forms the surface of the S1 substrate-binding site, and His23 on the other side modulates both carboxy-monopeptidase as well as carboxy-dipeptidase activity of the enzyme by binding the C-terminal carboxyl group of a substrate in two different sidechain conformations. CONCLUSIONS: The structure of cathepsin X exhibits a binding surface that will assist in the design of specific inhibitors of cathepsin X as well as of cathepsin B and thereby help to clarify the physiological roles of both proteases.     

单菌落PCR法直接快速鉴定重组克隆

利用单菌落PCR法直接筛选含有GFP、LTB-ST外源基因的重组克隆,阳性克隆可以扩增出目的条带,和质粒PCR扩增的结果一致。同时,单菌落PCR法也可应用于重组质粒转化后的农杆菌的筛选,单菌落PCR法的扩增结果和农杆菌液扩增的结果一致。结果表明,单菌落PCR法是一个有效简便的鉴定重组阳性克隆的方法。     

柑桔园土壤脲酶活性年周期变化及脲酶抑制剂氢醌的效应

本研究初步探明南亚热带赤红壤柑桔园土壤脲酶活性的年周期变化:冬季最低,春季升至高峰,夏季开始下降,直至秋季仍处于较低水平。室内模拟试验表明:氢醌对柑桔园土壤脲酶活性有明显抑制作用,其抑制率随浓度提高而增加,且随着培养时间的延长而逐渐下降;添加氢醌处理的尿素水解持续时间,比不加氢醌的延长约1倍。     

Genetic toxicology: Findings and challenges

The review highlights the history of genetic toxicology as a distinct research area, as well as the issues of genetic toxicology and development of its methodology. The strategies and testing patterns of genotoxic compounds are discussed with the purpose of identifying potential human carcinogens, as well as compounds capable of inducing heritable mutations in humans. The main achievements of genetic toxicology in the 20th century are summarized and the challenges of the 21st century are discussed.     

THE PHAGOCYTOSIS OF SOLID PARTICLES : III. CARBON AND QUARTZ.

1. The rates of ingestion of quartz and carbon particles by leucocytes, when both are in suspension in serum, was compared with the availability of the two particles as predicted from the calculated chances of collision with the leucocytes, and it was shown that carbon is ingested about 4 times as readily as quartz. 2. The greater ease of ingestion of carbon was verified by a new method of measuring phagocytosis, described as the film method in which the cells ingest particles as they creep about on a slide. 3. The relative rates of ingestion of carbon and quartz depend upon the condition of the cells, the difference increasing as the phagocytic activity of the cells decreases. 4. Sponge cells also ingest carbon about 3 times as readily as quartz. 5. The hypothesis is suggested that the cause of the more rapid ingestion of carbon may be identical with the cause of the greater instability of the carbon suspensions. 6. An inorganic analogy to this selective phagocytic action is offered. 7. The application to opsonins and agglutinins is discussed.     

生物化学教学中实用素材的推荐

本文旨在与从事生物化学教学的教师分享几个实用素材,正在学习生物化学的学生亦可直接使用.素材包括多媒体类例如绪论导入歌曲"Biochemistry",ATP合酶工作原理的视频,RCSB PDB蛋白质结构数据库,RasMol分子图像观察软件等;实物类例如DNA双螺旋结构的纸质模型,tRNA一二三级结构的纸质模型等.侧重素材...     

Phylogeny of Ephemeroptera (mayflies) based on molecular evidence

This study represents the first molecular phylogeny for the Order Ephemeroptera. The analyses included 31 of the 37 families, representing approximately 24% of the genera. Fifteen families were supported as being monophyletic, five families were supported as nonmonophyletic, and 11 families were only represented by one species, and monophyly was not testable. The suborders Furcatergalia and Carapacea were supported as monophyletic while Setisura and Pisciforma were not supported as monophyletic. The superfamilies Ephemerelloidea and Caenoidea were supported as monophyletic while Baetoidea, Siphlonuroidea, Ephemeroidea, and Heptagenioidea were not. Baetidae was recovered as sister to the remaining clades. The mayfly gill to wing origin hypothesis was not supported nor refuted by these data. Mandibular tusks were supported as having at least one loss in Behningiidae and, together with the burrowing lifestyle, possibly two origins. The fishlike body form was supported as plesiomorphic for mayflies with multiple secondary losses. Topological sensitivity analysis was used as a tool to examine patterns concerning the stability of relationships across a parameter landscape, providing additional information that may not have been acquired otherwise.     

Growth and enzyme synthesis during continuous culture of Trichosporon cutaneum on phenol

The soil yeast Trichosporon cutaneum was grown in continuous culture with phenol as the sole carbon source. The cultures were operated as carbon-limited chemostats or as steady-state continuous cultures without carbon limitation. Selected comparative runs were also conducted on glucose or acetate as carbon source. In addition to growth parameters, the activities of several intracellular enzymes were determined, comprising those directly involved in the degradation of phenol as well as auxiliary enzymes required for the generation of reducing power. All enzymes were assayed in detergent-permea-bilized cells. Phenol was found to serve as an excellent carbon source, comparable to glucose or acetate. The utilization of phenol in T. cutaneum is very efficient as indicated by a low maintenance requirement (0.01 g phenol/g cells.h). The cell yields obtained were on the order of 0.8 g cells/g phenol. Although the phenol-limited chemostats were run with fully phenol-induced cells, a further increase in the activities of isocitrate DH(NADP(+)), maleate DH and the phenol-degrading enzymes occurred after transition to nonlimiting condition. Enzyme activities increased in parallel with increasing phenol levels in the effluent, as well as with increasing toxicity. The significance of this phenomenon is discussed. The significance of this phenomenon is discussed. This elevation in enzyme activities in not related to an increase in specific growth rate.     

Histochemical investigations on the localization of the purple acid phosphatase in the bovine spleen

The localization of the purple tartrate-resistant, iron-containing acid phosphatase in the bovine spleen was studied by enzyme histochemistry at the light and electron microscopic levels as well as by immunohistochemistry. The purple phosphatase was localized only in lysosome-like-organelles of cells belonging to the reticulo-phagocytic system. The same cells were identified as containing large iron(III)-deposits as ferritin in homogeneously granular accumulations and freely in the cytoplasm, or as hemosiderin in siderosomes. The phagocytosing cells containing purple phosphatase and ferritin often had close contact with clusters of aged and deformed erythrocytes. A possible catabolic role of the purple enzyme as a phosphatase degrading phosphoproteins of the erythrocyte membrane and the cytoskeleton was assumed.     

"Aachen 3-D-finger". Development of a 3-D-digitizer for use in dental, oral and maxillary treatment

The "AACHEN 3D Finger" is a three-dimensional measuring system for use in all fields of dentistry. The system can equally as well be installed on a plane table, as fixed to the head of a patient. The measuring device is computer-assisted, and is able to localize, register and calculate any combination of points in the oral and maxillofacial area. The reference system can be changed at any time. The "AACHEN 3D Finger" can be used as a computer-a ded system in dentistry as well as in implantology or dental and maxillofacial surgery.     

Histochemical investigations on the localization of the purple acid phosphatase in the bovine spleen

Summary The localization of the purple tartrate-resistant, iron-containing acid phosphatase in the bovine spleen was studied by enzyme histochemistry at the light and electron microscopic levels as well as by immunohistochemistry. The purple phosphatase was localized only in lysosome-like organelles of cells belonging to the reticulo-phagocytic system. The same cells were identified as containing large iron(III)-deposits as ferritin in homogeneously granular accumulations and freely in the cytoplasm, or as hemosiderin in siderosomes. The phagocytosing cells containing purple phosphatase and ferritin often had close contact with clusters of aged and deformed erythrocytes.A possible catabolic role of the purple enzyme as a phosphatase degrading phosphoproteins of the erythrocyte membrane and the cytoskeleton was assumed.     

Cytochemical study of the DNA and histone in the tissues of the lily anther in the course of microsporo- and gametogenesis]

The DNA and histone content in the microsporocytes, microspores, generative and vegetative cells of the pollen grain of Lilium candidum L., as well as in the anther wall tissues, was estimated by double wavelength cytophotometry. The lack of histone, as compared with DNA content, was demonstrated in the microsporocytes at the late premeiotic interphase and early meiotic prophase, as well as in the young microspores and anther wall tissues. The analysis of hydrolysis curves suggests the increase of non-condensed chromatin during endothelial cell differentiation.     

An application of Berman's work on pool-model invariants in analyzing indistinguishable models for whole-body cholesterol metabolism

Berman and Schoenfeld used matrix transformations to study unidentifiable pool models. It is possible to use the method to examine if two models are output-indistinguishable, that is, if given the nature of tracer injections and observations, the two models have the same responses. The method is applied to two three-pool models for whole-body cholesterol metabolism. The indistinguishability of a mammillary model from a catenary model is proved using matrix transformations. The method is used in two ways, directly as well as after simplifying the problem. The two ways, as well as an analysis of the converse, help to show how the method is to be applied as well as the strengths and weaknesses of the method.