人血管能抑素基因的克隆、表达及其表达产物的纯化和生物活性测定

以人胎盘脐带组织为材料,提取组织总RNA,用netRTPCR方法合成人血管能抑素cDNA基因,将该cDNA克隆进pSP72载体获得重组质粒pSP72C, DNA序列分析结果与预期序列一致。用BamHⅠ和NdeⅠ双酶切,切下pSP72C上的血管能抑素cDNA,插入pET3c载体的相应位点获得重组表达质粒pETC, 转化E. coli BL21(DE3), SDSPAGE分析显示：在IPTG诱导下,血管能抑素基因获得了高效表达,表达量约占菌体总蛋白的 27.9 %,主要以包涵体形式存在。包涵体经过洗涤、裂解、蛋白复性以及Sephadex G75凝胶过滤层析等步骤后,获得了纯度达91.4 %的人血管能抑素。CAM实验证明10 μg纯化蛋白就能显著抑制鸡胚新生血管生成。     

壳聚糖酶的克隆表达与壳寡糖的制备分析

目的:克隆壳聚糖酶基因于大肠杆菌中实现高表达,制备壳寡糖。方法:以枯草芽孢杆菌总DNA为模板扩增壳聚糖酶基因(CSN),克隆至载体pET23a(+)上,转化菌株BL21(DE3)。重组子经0.5 mmol/L IPTG诱导后,SDS-PAGE和质谱检测与鉴定重组酶。酶纯化后水解壳聚糖,薄层色谱分析其水解产物。结果:质谱证明壳聚糖酶(31.5kDa)成功表达,表达量占菌体总蛋白的45%左右。纯化后重组酶浓度为900 mg/L,纯度95%、回收率85%,酶活力为10 000 U/mg。壳聚糖降解产物为壳二糖至壳四糖。结论:原核表达载体pET23a(+)-CSN构建正确,壳聚糖酶表达量与活性高,适用于水解壳聚糖制备壳寡糖。     

Liquid chromatographic assay of phenothiazine, thioxanthene and butyrophenone neuroleptics and antihistamines in blood and plasma with conventional and radial compression columns and UV and electrochemical detection

An assay strategy for determining a wide range of phenothiazine, thioxanthene and butyrophenone neuroleptics and antihistamines both alone and in combination in blood and plasma is described. The general method employs liquid chromatography with both conventional and radial compression nitrile bonded columns. Detection is by ultraviolet absorption spectrophotometry or by amperometry depending on the concentrations to be measured. Ultraviolet absorption is suitable down to 10 ng/ml. Below this level amperometry is preferable. The various compounds are used as internal standards for each other. The lower limit of detection is approximately 0.1 ng ml⁻¹ with a 10-ml sample. The within-run coefficient of variation is a maximum of 7.3%.     

Form and function of arabinogalactans and arabinogalactan-proteins

The occurrence, isolation, chemistry and physico-chemistry of plant arabino-3,6-galactans and arabino-3,6-galactan-proteins is reviewed. The structural relationships between arabino-3,6-galactans from gymnosperm wood, gum exudates of Acacia and other trees, and from plant callus cells and whole tissues are discussed. The nature of these proteoglycans is compared with the arabinose and galactose containing cell wall glycoproteins. Interactions of the arabino-3,6-galactan proteoglycans with carbohydrate binding proteins and with Yariv antigens are described. The utility of these reactions for both cellular and subcellular localization of the proteoglycans is discussed. The possible biological roles of the arabinogalactans and the arabinogalactan-proteins are reviewed.     

Synthesis and Antioxidant Activity of Carane and Pinane Based Sulfenimines and Sulfinimines

The synthesis of sulfenimines and sulfinimines has been carried out with 10‐hydroxyisocamphylthiol. The configuration of the compounds has been deduced by methods of NMR, DFT calculations and X‐ray diffraction analysis. The cytotoxic, antioxidant and membrane‐protective activity of the synthesized compounds as well as of the previously obtained sulfenimines and sulfinimines based on 4‐caranethiol have been determined.     

Synthesis and turnover of cerebrosides and phosphatidylserine of myelin and microsomal fractions of adult and developing rat brain.

The synthesis and turnover of cerebrosides and phospholipids was followed in microsomal and myelin fractions of developing and adult rat brains after an intracerebral injection of [U-14C]serine. The kinetics of incorporation of radioactivity into microsomal and myelin cerebrosides indicate the possibility of a precursor-product relationship between cerebrosides of these membranes. The specific radioactivity of myelin cerebrosides was corrected for the deposition of newly formed cerebrosides in myelin. Multiphasic curves were obtained for the decline in specific radioactivity of myelin and microsomal cerebrosides, suggesting different cerebroside pools in these membranes. The half-life of the fast turning-over pool of cerebrosides of myelin was 7 and 22 days for the developing and adult rat brain respectively. The half-life of the slowly turning-over pool of myelin cerebrosides was about 145 days for both groups of animals. The half-life of the rapidly turning-over microsomal cerebrosides was calculated to be 20 and 40 h for the developing and adult animals respectively. The half-life of the intermediate and slowly turning-over microsomal cerebrosides was 11 and 60 days respectively, for both groups of animals. The amount of incorporation of radioactivity into microsomal cerebrosides from L-serine was greatly decreased in the adult animals, and greater amounts of the precursor were directed towards the synthesis of phosphatidylserine. In the developing animals, considerable amounts of cerebrosides were synthesized from L-serine, besides phosphatidylserine. The time-course of incorporation indicated that a precursor-product relationship exists between microsomal and myelin phosphatidylserine. The half-life of microsomal phosphatidylserine was calculated to be about 8 h for the fast turning-over pool in both groups of animals.     

Pleasure and disgust: memories and associations of pleasant and unpleasant odours in Germany and Japan

The question of whether odour experiences have a function inthe cultures of the technically industrialized world was investigatedby interviews with German (166) and Japanese (88) subjects.They were asked to name pleasant and unpleasant odours frommemory and to give associations regarding them. The participantsenumerated 2040 odours and 3520 associations. Although Japanesesubjects in general gave less information than the Germans,the results for both cultures were very similar in quality aswell as quantity. The odour memories included the whole physicaland social environment and the associations showed the far-reachingeffect of odour experiences. Both pleasant and unpleasant odourswere remembered to an equal extent. Most of the odours recalledwere assessed similarly by the subjects, as either pleasantor unpleasant. Obviously, individual likings or aversions aredominated by underlying evaluations common to all subjects ofboth cultures. Uniformly judged odours were, for example, odoursof plants (pleasant) and odours of rotten and decomposed things(unpleasant). It is discussed whether this finding reflectspreprogrammed survival strategies. The few cultural differenceswhich were found seemed to reflect different life habits, normsand values in the two countries.     

Conformation and proteolysis of glucagon and insulin in surfactant and lipid solutions

The effects of micelles of nonionic, zwitterionic, anionic and cationic surfactants and lipids on the conformation of glucagon and insulin have been investigated by circular dichroism and intrinsic protein fluorescence. The influence of these amphipathic compounds on the hydrolysis, monitored by HPLC, of glucagon and insulin by trypsin and chymotrypsin has also been studied. The alpha-helix content of glucagon was increased to a similar extent by all the micelles, irrespective of their charge and of whether they were synthetic surfactants or phospholipids. The amphipathic compounds always induced a blue-shift in the wavelength of maximum emission of fluorescence of glucagon of about 9 nm, whereas the fluorescence intensity was increased in some cases and decreased in others. The circular dichroism of insulin was also modified in some cases. Some amphipathic compounds protected glucagon against proteolysis by trypsin and chymotrypsin very markedly, whereas others did not protect at all or only slightly protected the hormone. Two hypotheses have been formulated to explain the different results. Hydrolysis of insulin was generally not influenced by surfactants and lipids.     

Cinnamoyl- and hydroxycinnamoyl amides of glaucine and their antioxidative and antiviral activities

The aporphine alkaloid glaucine has been converted into 3-aminomethylglaucine and its free amino group has been linked to cinnamic, ferulic, sinapic, o-, and p-coumaric acids. The antioxidative potential of the synthesized amides was studied against DPPH(*) test. All of the tested compounds demonstrated higher radical scavenging activity than glaucine and 3-aminomethylglaucine, and lower antioxidative effect than the free hydroxycinnamic acids. The newly synthesized compounds were tested in vitro for antiviral activity against viruses belonging to different taxonomic groups.     

Prenatal ages and stages-measures and errors

BACKGROUND: The confusing term "gestational age" is generally either not defined or is used for menstrual "age," postovulatory age, or postfertilizational age. The designation (post)menstrual weeks and/or days is very useful in obstetrics but, because prenatal age extends from fertilization to birth, menstrual "age" is a misnomer. The term "stage" has a specific morphological meaning in embryology and should not be used either for ages or for lengths. METHODS: Embryonic age is best assessed, when possible, from the 23 internationally recognized morphological stages. A morphological staging system is not available for the fetal period, and fetal age is assessed mainly from measurements. RESULTS: Among these, the unsatisfactory designation crown-rump length (CRL) should be replaced, in ultrasonic biometry as well as in embryology, by the greatest length (GL), exclusive of the lower limbs. These points are discussed in detail, and justification for the views expressed is provided. CONCLUSIONS: The continuing confusion concerning prenatal age is shown to be unnecessary once the ambiguous and superfluous term "gestational age" is abandoned.     

Glycosidase and phosphatase activities in U-937 and some clones and sublines

1. The activities of nine glycosidases, lysozyme and acid and alkaline phosphatases were compared in the histiocytic lymphoma cell line U-937 and a set of clones and sublines derived from this line. 2. The patterns of the different enzyme activities and selected enzyme ratios have been used as a method to distinguish between different clones and sublines. 3. Sublines with high lysozyme levels were rich in most cell-bound glycosidases. 4. During long-term growth distinct enzyme patterns of individual lines were preserved. 5. The enzyme pattern during a cell culture growth cycle was basically stable.     

Astrocytes and Synaptosomes Transport and Metabolize Lactate and Acetate Differently

Astrocytes transport the monocarboxylate acetate, but synaptosomes do not. The reason for this is unknown, because both preparations express monocarboxylate transporters (MCT). The transport and metabolism of lactate, another monocarboxylate, was examined in these two preparations, and the results were compared to those for acetate. Lactate transport is more rapid in astrocytes than in synaptosomes, but of lower affinity (Kms of 17 and 4 mM, respectively). Lactate (0.2 mM) is metabolized to CO2 more rapidly in synaptosomes than in astrocytes (rates of 0.37 and 0.07 nmol x mg protein(-1) x min(-1), respectively). The reason for this is unclear, but cellular differences in lactate dehydrogenase isotype expression may be involved. Acetate is metabolized to CO2 more rapidly in astrocytes than in synaptosomes (rates of 0.43 and 0.02 nmol x mg protein(-1) x min(-1), respectively). This is likely due to cellular differences in the expression of monocarboxylate transporter subtypes.     

Carnitine and creatine content of tissues of normal and alloxan-diabetic sheep and rats

The concentration of carnitine in liver increased 28-fold and urinary carnitine excretion 5-fold in alloxan-diabetic sheep. In contrast there were no similar increases in alloxan-diabetic rats. The creatine content of liver decreased 3-fold and creatine excretion decreased 2-fold in diabetic sheep. In contrast the creatine content of liver increased nearly 4-fold in diabetic rats with no change in creatine excretion. The marked increased in production of carnitine by the liver of the diabetic sheep appears possible because of decreased production and excretion of creatine.     

Knowledge and opinions about tissue donation and transplantation among Polish students and physicians

The idea of transplantation seems to be commonly identified by lay and professional people only with transplantation of vascularized organs like kidney or heart. The question arises whether there is any awareness of tissue transplantation among the public. A survey was therefore undertaken to assess awareness of and approaches to tissue donation and transplantation among selected social groups. A questionnaire on donation and transplantation issues was administered to respondents from the following groups: secondary school students, non-medical university students, medical university students, physicians. On the whole, 441 non-randomly sampled respondents were surveyed. The awareness of tissue transplantation is narrower than the awareness of organ transplantation. The support for tissue transplantation is weaker than for organ transplantation. This study shows that there is an acute need for education in the legal aspects of transplantation and that ways of motivating healthcare professionals to promote transplantation should be developed.     

Chiral discrimination by HPLC and CE and antifungal activity of racemic fenticonazole and its enantiomers

Fenticonazole is a chiral antifungal agent, used in therapy as the racemic mixture. The investigation on the chirality of fenticonazole is reported in this study. rac-Fenticonazole was resolved by HPLC and by capillary electrophoresis (CE). The chiral stationary phase (CSP), used in HPLC, was Daicel OD-H, a commercial phase, which allowed the separate collection of the two enantiomers. The chiral selectors used for CE were some cyclodextrin derivatives. The analysis time required from CE was about the half the HPLC enantioseparation time. The biological activity of the rac-mixture and each individual enantiomer was tested against Cryptococcus neoformans and two Aspergillus nidulans strains. The minimum inhibitory concentration (MIC) evaluation showed that the eutomer was the enantiomer chromatographically more retained and had a longer migration time in the electrophoretic enantioseparation. The CD spectrum of the eutomer showed a positive Cotton effect.     

Obstetrics and gynecology: AIDS and pregnancy

The Scientific Board of the California Medical Association presents the following inventory of items of progress in obstetrics and gynecology. Each item, in the judgment of a panel of knowledgeable physicians, has recently become reasonably firmly established, both as to scientific fact and important clinical significance. The items are presented in simple epitome and an authoritative reference, both to the item itself and to the subject as a whole, is generally given for those who may be unfamiliar with a particular item. The purpose is to assist busy practitioners, students, research workers, or scholars to stay abreast of these items of progress in obstetrics and gynecology that have recently achieved a substantial degree of authoritative acceptance, whether in their own field of special interest or another.The items of progress listed below were selected by the Advisory Panel to the Section on Obstetrics and Gynecology of the California Medical Association and the summaries were prepared under its direction.     

翦股颖和高羊茅对铜、铅吸收及耐受性

测定了高羊茅和翦股颖两种草坪植物在Cu、Pb污染下发芽率、叶绿素、净光合速率和SOD的变化,以及两种草对Cu、Pb的吸收.结果表明, 重金属污染对高羊茅种子的萌发产生显著影响.高浓度Pb污染以及Pb、Cu复合污染对高羊茅的叶绿素影响很大,Cu单独污染对高羊茅叶绿素的抑制作用较小.翦股颖的叶绿素变化不显著.在3个Pb处理及350 mg·kg^-1 Cu处理下,翦股颖的SOD活性均高于对照,而只有在700 mg·kg^-1Pb 和350 mg·kg^-1 Cu+1 100 mg·kg^-1 Pb处理下高羊茅的SOD活性才升高.高羊茅的净光合速率受Cu污染影响较小,而受Pb污染影响较大.在Cu、Pb单独污染条件下,翦股颖净光合速率均呈下降趋势.从生理角度来看,翦股颖对Cu、Pb污染的耐受性强于高羊茅,而高羊茅对Cu污染的耐受性强于Pb.高羊茅Cu吸收量大,但Cu吸收量不随污染浓度升高而升高.翦股颖对土壤Pb的吸收能力较强, 且Pb吸收量随污染浓度的增加而增加.翦股颖和高羊茅可分别用于Pb和Cu污染土壤的治理.     

Protein synthesis by isolated etioplasts and chloroplasts from pea and wheat and the effects of chloramphenicol and cycloheximide

Etioplasts capable of incorporating ¹⁴C-leucine into protein have been isolated from dark-grown pea and wheat plants. The requirements for leucine incorporation for etioplasts were similar to those for chloroplasts. An ATP-generating system, Mg²⁺, and GTP were required. The amino-acid-incorporation activity of etioplasts from wheat was comparable to that of chloroplasts on an RNA basis, whereas the activity of pea etioplasts was about 50% of the activity of pea chloroplasts. The incorporation of leucine into protein by etioplasts and chloroplasts from pea and wheat was inhibited by chloramphenicol, and to a slight extent by cycloheximide.     

Adsorption of Adenine and Thymine on Zeolites: FT-IR and EPR Spectroscopy and X-Ray Diffractometry and SEM Studies

The interactions of adenine and thymine with and adsorption on zeolites were studied using different techniques. There were two main findings. First, as shown by X-ray diffractometry, thymine increased the decomposition of the zeolites (Y, ZSM-5) while adenine prevented it. Second, zeolite Y adsorbed almost the same amount of adenine and thymine, thus both nucleic acid bases could be protected from hydrolysis and UV radiation and could be available for molecular evolution. The X-ray diffractometry and SEM showed that artificial seawater almost dissolved zeolite A. The adsorption of adenine on ZSM-5 zeolite was higher than that of thymine (Student-Newman-Keuls test-SNK p<0.05). Adenine was also more greatly adsorbed on ZSM-5 zeolite, when compared to other zeolites (SNK p<0.05). However the adsorption of thymine on different zeolites was not statistically different (SNK p>0.05). The adsorption of adenine and thymine on zeolites did not depend on pore size or Si/Al ratio and it was not explained only by electrostatic forces; rather van der Waals interactions should also be considered.