测定肿瘤细胞内外5-氟尿嘧啶含量的方法研究

目的建立了高效液相色谱法测定A549组胞内外5-氟尿嘧啶含量的方法,为探索5-氟尿嘧啶的作用机理奠定基础。方法色谱柱采用Hypersil ODS柱（4．6mm×250mm,5μm）;流动相为甲醇·水=2：98（V／V）;流速：0．8ml／min;柱温：30℃;检测波长：265nm;进样量为5μl。结果细胞内液中5-氟尿嘧啶在0.1～50．0μg/ml范围内线性关系良好（r=0．9996）,平均回收率为97．65％,RSD为0．40％,日内和日间精密度分别为1．30％,1．04％;细胞跨液中5-氟尿嘧啶在1．0～250．0μg/ml范围内线性关系良好（r=0.9999）,平均回收率为102.34％,RSD为2．11％,日内和日间精密度分别为1．32％,1．06％。结论该色谱方法简便易行,准确度高,重现性好,可用于细胞内外5-氟尿嘧啶浓度的动态变化规律研究。     

Novel and sensitive noncompetitive enzyme immunoassay for kassinin in rat plasma

A novel and sensitive noncompetitive enzyme immunoassay for kassinin is described. Kassinin was biotinylated using sulfosuccinimidyl-6-(biotinamido)hexanoate. The biotinylated kassinin was trapped on anti-kassinin IgG-coated polystyrene balls and, after washing to eliminate other biotinylated substances, was eluted with HCl. The biotinylated kassinin eluted was reacted with anti-kassinin Fab'-peroxidase conjugate and trapped onto streptavidin-coated polystyrene balls. Peroxidase activity bound to the polystyrene balls was assayed by fluorimetry. The detection limit of kassinin was 0.13 pg (0.1 fmol)/tube or 0.065 microgram/l of rat plasma, which was 750-fold or 15-fold lower than that for competitive radioimmunoassay.     

加替沙星-壳聚糖纳米粒胶联羊膜药膜的制备及体外实验研究

目的制备一种新型生物多功能复合材料——加替沙星．壳聚糖纳米粒胶联羊膜药膜,并观察其体外缓释性能及抑菌作用。方法采用离子胶联法制备加替沙星－壳聚糖纳米粒并检测其表征,然后将栽药纳米粒加入到纤维蛋白胶中,混匀后再与羊膜胶联制成加替沙星－壳聚糖纳米粒胶联羊膜药膜,光镜及扫描电镜下观察其形态学特征,高效液相色谱法测定其中加替沙星的浓度,微量肉汤稀释法检测其体外抑菌活性。结果加替沙星纳米粒的粒径为291±33nm,载药量为10．46％,包封率为61．32％。载有纳米药物的纤维蛋白胶与羊膜基底面粘合紧密,呈圆形的加替沙星纳米粒附着在胶原纤维的网状结构上。在体外,加替沙星－壳聚糖纳米粒胶联羊膜药膜可持续释药达15天,对金黄色葡萄球菌和铜绿假单胞菌的最低抑菌浓度分别为0．05μg／ml和0．42μg／ml。结论加替沙星－壳聚糖纳米粒胶联羊膜药膜在体外具有良好的缓释性能及抑茵作用。     

Y型明渠交汇水流分离区的数值分析

针对Y型明渠交汇口的水流特性，应用三维各向异性的雷诺应力模型，采用交错网格上的有限体积法离散控制方程，用SIMPLE算法求解压力-速度场。数值计算结果与物理模型试验结果吻合较好，并据此重点探讨了不同交汇角条件下交汇口分离区尺寸的变化规律，提出Y型交汇水流分离区的定义和分离区尺寸与汇流比的函数关系。     

Frederick Pavy (1829-1911) and his opposition to the glycogenic theory of Claude Bernard

For more than 50 years the Guy's Hospital physician Frederick Pavy (1829-1911) attempted to discredit the theory of his erstwhile teacher, Claude Bernard, that liver glycogen was broken down to supply sugar to the systemic circulation. His opposition was driven by his clinical perceptions and was based on two assumptions: the first was that the kidney was a simple filter through which small molecules would diffuse, so that sugar had to be prevented from reaching the systemic circulation. For Pavy, the liver was the barrier. The second was teleological: he could not believe that nature would operate in what he saw as a defective way, i.e. converting sugar into glycogen and then back again. At the beginning of his long working life Pavy regarded himself as a physiologist and was critical of the stagnancy of English physiology which was kept afloat by amateurs like himself in whatever time they could spare from busy private practice. At the end he came to see his own view of carbohydrate metabolism as symbolic of the schism between responsible clinicians (himself) and irresponsible daydreaming physiologists (his opponents).     

Collagenolytic activity of eosinophilic granuloma in vitro.

Lytic activity of eosinophilic granuloma and other tumours was studied in vitro on collagen substrate. Collagen degradation was measured through the release of hydroxyproline-rich peptides into the medium. The in vitro lytic action was at a maximum in the case of EG and was correlated with the presence of histiocytic cells.     

Differential alterations in branched-chain amino acid decarboxylation in liver of hypophysectomized rats

Summary Valine decarboxylation was significantly increased and leucine decarboxylation was significantly decreased in rat liver slices following hypophysectomy. In both normal and hypophysectomized rats decarboxylation of leucine exceeded that of valine in slices whereas the reverse was observed with the respective keto acids and mitochondria.Acknowledgments. This study was supported by the National Institutes of Health and the Samuel A. Berger Foundation.     

Peroxidase activity in mitochondria of Prototheca moriformis

Summary Peroxidase activity was investigated by the use of diaminobenzidine method in fixed cells of Prototheca moriformis. A strong peroxidase activity was observed in the mitochondria. DAB staining was unaffected by KCN, aminotriazole and antimycin A, but it was completely inhibited by methanol-nitroferricyanide.     

Growth and longevity of Wistar rats receiving a diet whose protein content is rapidly lowered in relation to aging]

Growth and longevity of the Rats were the same when: (i) the diet was rich in casein (21%), from weaning to death: (ii) the casein content of this diet (without B12) was progressively lowered from weaning to 200 days of age, and thereafter was 7%. When the casein level had been too rapidly lowered, inducing retardation of growth after 75 days, maximal growth was lowered and life span was increased.     

近距离薄煤层回采巷道布置及护巷方式研究

为了确定大安山矿＋680m水平9槽近距离薄煤层回采巷道合理的布置方式及护巷方式,根据理论分析和数值模拟,确定了单一煤层开采的开采方案,提出了9槽回采巷道留3～5m窄小煤柱护巷的无煤柱护巷方式,及9上和9下煤层回采巷道采用外错式和内错式的相结合的布置方式,并研究了相应的支护形式。数值模拟结果表明选择无煤柱护巷方式是合理的,留煤柱护巷方_式支承压力的影响范围比无煤柱护巷大2．5倍,煤柱上垂直应力比无煤柱护巷大2．5～7．5MPa。     

溧阳市沙河水库东副坝溃坝生命损失估算

应用溃坝洪水软件BREACH和FLDWAV分析溧阳市沙河水库东副坝在100年一遇设计洪水位23．17m时下游坡高程点8．40m处管涌诱发溃坝的洪水状况,确定大致的淹没范围,计算了溃坝洪水的严重性,估算了风险人口,应用Graham法定量地估算了生命损失,重点研究了生命损失与警报时间的关系,提出了确保2h警报时间的建议,加强非工程措施,避免生命损失。     

振孔高压旋喷施工技术

针对普通高压旋喷施工防渗墙工序繁琐、质量稳定性不高等情况,研究出一种振孔高压旋喷技术,该技术凭借高桅杆,用振管浆管合一和振动回转的方法高速成孔,当振动成孔达到设计深度后上提即构成二管法的旋喷,成为一种新的施工方法。使用该技术后,施工中可不间断连贯作业,施工效率高出普通高压旋喷2倍左右。同时可以根据工程需要采用不同工艺,修筑厚1．2m或0．2m的防渗墙。该技术施工参数大,喷射影响半径远,墙体连续性与防渗性好,在三峡三期围堰防渗墙与三峡电源电站围堰防渗墙的施工中均收到很好的效果。     

Novel and sensitive noncompetitive enzyme immunoassay for kassinin in rat plasma

Summary A novel and sensitive noncompetitive enzyme immunoassay for kassinin is described. Kassinin was biotinylated using sulfosuccinimidyl-6-(biotinamido)hexanoate. The biotinylated kassinin was trapped on antikassinin IgG-coated polystyrene balls and, after washing to eliminate other biotinylated substances, was eluted with HCl. The biotinylated kassinin eluted was reacted with anti-kassinin Fab'-peroxidase conjugate and trapped onto streptavidin-coated polystyrene balls. Peroxidase activity bound to the polystyrene balls was assayed by fluorimetry. The detection limit of kassinin was 0.13 pg (0.1 fmol)/tube or 0.065 g/l of rat plasma, which was 750-fold or 15-fold lower than that for competitive radioimmunoassay.     

Inactivation of N-assimilating enzymes and proteolytic activities in wheat leaf extracts: Effect of pyridine nucleotides and of adenylates

Summary Nitrate reductase was protected from inactivation in wheat leaf extracts by NADH, while NADPH was less effective. NAD, NADP or adenylates did not affect nitrate reductase inactivation in vitro. Glutamine synthetase was more stable than nitrate reductase and was protected from inactivation by ATP. ADP, AMP or pyridine nucleotides had no or only a minor effect on the decrease of glutamine synthetase activity in extracts. The caseolytic activity extracted from senescing leaves was slightly decreased by NADH and NADPH but this effect was not sufficient to explain the stabilization of nitrate reductase by NADH. Oxidized pyridine nucleotides and adenylates had no major effect on the caseolytic activity under the conditions used.This work was supported by grant 3.067-0.81 from the Swiss National Science Foundation. Author for correspondence: U.F.     

Effect of estrogen administration on the induction of the plasma prolactin afternoon surge and on anterior pituitary prolactin concentration extracted at different pHs

Ovariectomized (OVX) rats were injected with various doses of polyestradiol phosphate (PEP); the anterior pituitary (AP) prolactin (PRL) concentration and the plasma afternoon surge of PRL were observed 1 week later by radioimmunoassay. AP PRL was extracted using carbonate and phosphate buffers at either pH 7.6 or 10.6. The AP concentration of PRL was greater when the AP was extracted with buffers at pH 10.6 and the phosphate buffer was the most efficient. The concentration of PRL in the AP more closely reflected the magnitude of the estrogen-induced afternoon surge when the AP was extracted at pH 10.6 and this was especially so when the higher levels of estrogen were administered.     

Phaeomelanic pigments from a human melanoma

Summary The pigments in melanomas from 2 patients were studied with regard to solubility and chemical composition. Melanoma pigment from a patient with red-blonde hair was alkali-soluble and contained 9 or 10% sulfur and was thus of phaeomelanic type. Melanoma pigment from a patient with red-brown hair was insoluble in 0.2N NaOH. Its sulfur content was 6%. This pigment was eumelanic with regard to solubility characteristics but the sulfur content was higher than previously observed for eumelanin.Supported by grants from the Swedish Cancer Society (No. 626-B75-04XA), the Swedish Medical Research Council (No. B76-04X-00056-12), and the Walter, Ellen, and Lennart Hesselman Foundation for Scientific Research. ProfessorProta was a visiting scientist of the Swedish Cancer Society (No. 626-B75-04U).     

Cyto-immunochemical detection of gamma endorphin in swine adenohypophysis]

An immunserum was prepared from gamma endorphin and its specifity was checked by the indirect method. It was tested on hypophysis which were taken from Pigs since birth till 3 months old. The anterior lobe as well as the intermediate lobe have reacted. The same cells were positive in the anterior lobe and recognized the anti-ACTH, anti-beta MSH and anti-beta LPH immunserums. However, the reaction was more labile than with these last immunserums and it was varying with the delay of fixation after the death and the penetration in the gland by the fixator.     

Biodegradation of nitrilotriacetic acid (NTA) in the absence of oxygen

Summary A microbiol culture able to grow in the absence of oxygen with nitrilotriacetate (NTA) as the sole source of carbon and energy was enriched from river sediment. Growth was strictly dependent on the presence of nitrate and the results indicate that nitrate was exclusively used as the electron acceptor and was reduced to dinitrogen (N₂). The stoichiometry of anaerobic NTA degradation by the enrichment culture was determined.     

Inhibition of collagen synthesis by interleukin-1 in three-dimensional collagen lattice cultures of fibroblasts

Interleukin-1 (Il-1) was added to collagen lattice cultures of human skin fibroblasts. No cell division was induced, the ability of fibroblasts to contract the lattices was decreased and a dose-related inhibition of collagen synthesis without effect on non-collagen proteins was found. Indomethacin had no influence on these effects.     

Preferential neurotoxicity of pentobarbital on nerve and glial cells in culture

The effect of pentobarbital was studied in a mixed population of nerve and glial cells dissociated from brains of 7-day chick embryos and maintained in culture. Pentobarbital-Na was added in various concentrations ranging from 5 X 10(-5) M to 1 X 10(-3) M. The neuronal density was monitored by counting the neurons, neuronal identity was established by staining for Nissl Bodies and acetylcholinesterase. Over a culture period of 3 weeks, it was found that the barbiturate exerts a preferential dose-dependent cytotoxic effect on neurons.