Effect of scopolamine on the memory of exploratory behavior in the mouse]

In the present work it has been evaluated the action of scopolamine on the extent of exploration in mice, whose exploring behaviour had been already earlier examined. Such behaviour has been evaluated using a hole-board. The goal has been to detect the influence of the substance on the short-term memory of mice. The method used has shown to be effective. By the exam of the results of this work it can be concluded that the scopolamine at a dose of 1 mg/kg has an evidence effect of short-time memory in mice by causing a hypomnesia.     

铜绿假单胞菌生物降解特性的研究进展

近年来在环境污染物的生物降解研究方面有了很大进展。铜绿假单胞菌(Pseudomon asaeruginosa,PA)作为重要的降解菌株之一,具有较强的降解能力,可降解物质种类广泛,在环境污染物的生物降解中具有重要作用并占据重要地位。本文综述了PA的降解特性、代谢途径、遗传基础与酶系及促降解物质在生物降解方面的研究进展。     

Properties of biocomposites based on lignocellulosic fillers

This paper is focused on the analysis of the thermal and mechanical behaviour of processed biocomposites (biodegradable composites). These materials have been created by extrusion and injection moulding. The matrix, a biodegradable and aromatic copolyester (polybutylene adipate-co-terephthalate), has been fully characterised (NMR, SEC). The lignocellulosic materials used as fillers are a by-product of an industrial fractionation process of wheat straw. Different filler fractions have been selected by successive sieving, and then carefully analysed (granulometry, chemical structure). Cellulose, lignin, and hemicellulose contents have been determined through different techniques. The biocomposites thermal behaviour has been investigated by TGA (thermal degradation) and DSC (transition temperatures, crystallinity). These materials present good mechanical behaviour due to high filler-matrix compatibility. The impacts of filler content, filler size and the nature of each fraction have been analysed. To predict the mechanical behaviour, Takayanagi’s equation seems to provide an accurate answer to evaluate the modulus in a range, 0–30 wt% of fillers.     

Effect of sucrose on the optical properties of dipalmitoylphosphatidylcholine

The gel to liquid crystal phase transition of dipalmitoylphosphatidylcholine (DPPC) has been followed by the change in absorbance at 400 nm; this change is due to the change in lipid light scattering properties during the transition. The effect of sucrose on the change in absorbance during the transition of DPPC has been investigated. It has been shown that the presence of sucrose or glycerol in the multilamellar liposome suspension increases the change in absorbance due to the main transition, decreases the total absorbance, and decreases the change in absorbance due to the pretransition. This effect of sucrose and glycerol is shown to be an optical effect which is correlated with solvent index of refraction.     

Effects of prostaglandins on erythropoiesis

A model has been presented for the role of the kidney in the physiologic and pathophysiologic control of erythropoiesis. It is postulated that an oxygen deficit created by anemia or hypobaric hypoxia results in the release of prostacyclin and its metabolite 6-keto PGE1, and the release of PGE2 with ischemic hypoxia. Prostacyclin, 6-keto-PGE1, or PGE2 activation of adenylate cyclase, an increase in cyclic AMP, activation of a protein kinase and the phosphorylation of hydrolases, which have been released from lysosomes by hypoxia, lead to increased biosynthesis of erythropoietin (Ep). The mechanism of labilization of lysosomes and the release of hydrolases from these cell organelles is postulated to be related to increases in cyclic GMP levels in a renal cell. An Ep-producing human renal carcinoma cell line grown in tissue culture has been demonstrated to produce significant amounts of PGE2. Meclofenamate, an inhibitor of prostaglandins synthesis, was found to inhibit in vitro production of PGE2, Ep, and dome formation in these renal carcinoma cells, giving support to our hypothesis that pathophysiologic production of Ep tumor cells depends upon prostaglandins production. An Ep-producing clone from this renal carcinoma cell line has been developed that contains low electron density (LED) cells after the cells reach confluency, which show a cytoplasm, with abundant and widely dilated endoplasmic reticulum, an oval nucleus, dispersed chromatin, and prominent nucleoli. These are the cells responsible for dome formation and Ep production. Non-EP-producing clones have also been produced from this renal carcinoma cell line, which did not produce domes even at high cell density and had a distinctly different cell type than the Ep-producing clone. Thus, it is postulated that prostacyclin (PGI2) and its metabolite 6-keto PGE1 play a significant role in hypoxic hypoxia stimulation of Ep production and PGE2 is involved in ischemic hypoxia and renal carcinoma cell production of Ep. A modulating effect of PGE2 and PGD2, the two primary bone marrow prostaglandins, has been proposed in Ep stimulation of the erythroid progenitor cell compartment (CFU-E and BFU-E).     

Effect of intensive 24-hour shift work on reliability of operators' activity

Psychophysiological peculiarities of the effect of 24-hour shift work on psychophysiological indices of an operator's efficiency have been considered. It is found that significant manifestations of the fatigue have been developed in servicemen-operators as a result of daily shift-work. The informative psychophysiological characteristics, which can be used as reliable indicators of fatigue level, have been distinguished. A hypothesis has been proposed on the availability of several compensatory mechanisms in maintenance of the work capacity in operators in long-term shift work. An integral index of the reliability of operators' activity has been developed, allowing to assess the quality of work, using a wide range of intensities of the proposed signals as well as to receive data on the overall possibilities of an operator to process information at the given level of reliability.     

Influence of phospholipids on the respiratory activity of embryonal heart cells cultured in vitro in presence of different ethanol concentrations

The influence of phospholipids on respiratory activity of embryonal heart cells, trated with certainly harmful concentrations of ethanol, has been discussed. It has been concluded that when the cell is deeply impaired the administration of phospholipids does not seem to have positive effects. In this condition an irreversible morphological alteration has been induced.     

Effect of the delta-sleep peptide on parasympathetic regulation of the cardiac rhythm

Effect of delta-sleep peptide (60 nM/kg) on the parasympathetic regulation of cardiac activity has been studied in the experiments on rabbits. It has been established that intravenous administration of this peptide to voluntary-behaving animals results in heart rate reduction by an average of 16%, that can be eliminated by atropine. Delta-sleep peptide has been demonstrated to intensify negative chronotropic effect in the case of directly irritated wandering nerve. The data obtained explain a protective effect of delta-sleep peptide on the heart under emotional stress.     

The Action of Ethylenediaminetetra-acetic Acid on Pseudomonas aeruginosa

It has been shown that ethylenediaminetetra-acetic acid (EDTA) has a direct bactericidal action against strains of Pseudomonas aeruginosa and Alcaligenes faecalis . The action against Ps. aeruginosa is considered to take the form of competition for a metal essential to the integrity of the cells: some of the factors influencing this antibacterial action have been discussed. From a study of the release of solutes from cells of Ps. aeruginosa , it was concluded that the action of EDTA takes place at the cell wall of the organism: an effect by EDTA on the isolated walls of sensitive organisms has been demonstrated.     

Inhibitory effects of human cystatin C on plum pox potyvirus proteases

The effect of different protease inhibitors on the proteolytic processing of the plum pox potyvirus (PPV) polyprotein has been analyzed. Human cystatin C, an inhibitor of cysteine proteases, interfered with the outoprocessing of the viral papain-like cysteine protease HCPro. Unexpectedly, it also had an inhibitory effect on the autocatalytic cleavage of the Nla protease which, although it has a Cys residue in its active center, has been described as structurally related to serine proteases. Other protease inhibitors tested had no effect on any of the cleavage events analyzed.     

Inhibition of trypsin-like enzymes on cells with rhodamine-aprotinin

Aprotinin, a polypeptide inhibitor of trypsin-like enzymes, has been labelled with rhodamine. Rhodamine-aprotinin inhibits trypsin in free solution in an identical manner to aprotinin. Rhodamine-aprotinin binds to trypsin-like enzymes on cells in formaldehyde fixed wax embedded sections. This technique has been used to locate cells possessing trypsin-like enzymes by means of fluorescent microscopy. In the present study we have used this technique to locate tumour cells.     

Effect of magnesium ions on heat denaturation of DNA

The dependence of animal DNA denaturation on magnesium ion concentration has been studied in the range (10(-6)--10(-1) M with sodium ion content of 10(-3) and 10(-2) M. Special attention has been given to the effect of multivalent metallic impurities bound to DNA. An increase of DNA thermal stability has been shown to occur in the magnesium concentration rage of 10(-6)--10(-4) M. At concentrations exceeding 10(-3) M the T M begins to decrease. The dependence of the DNA melting range on magnesium ion concentration has a maximum at approximately 10(-5) M Mg2+. At low magnesium and sodium ion concentrations a strong asymmetry of the melting curves has been observed. This effect can be described in terms of the melting theory for DNA complexed with small molecules and is explained by magnesium ion redistribution from the denatured portions of DNA to native ones. The method for calculation of melting curves in the DNA-ligand system has been proposed. Studies of thermal denaturation parameters have been shown to be an effective method for the estimation of binding constants of ligands to native and denatured DNA.     

茶多酚提取方法的研究进展

茶多酚是一种理想的食品天然抗氧化剂,具有抗癌治病、防衰老、防辐射、消除人体自由基等多种生理功效,广泛用于食品、油脂、医药、化工等行业。近年来,对于茶多酚的提取方法多见于报遗,本文就国内外茶多酚提取方法的研究进展情况作以综述。     

Computer assisted screening: effect on the patient and his consultation.

The initial impact of computer assisted preventive screening in general practice consultations has been monitored. The technology has not been found stressful by patients, and the power of the consultation to alleviate low arousal has been increased by computer use. No appreciable increase in the durations of consultation was detected, despite an average computer initiated input of two minutes eight seconds. The computer has successfully prompted preventive screening and health education with a sixfold increase in the number of potentially relevant procedures being mentioned. The actual information presented by the computer has been shown to be crucial, with the terminal''s mere presence an ineffective reminder. The computer terminal was used in 65% of the consultations for which it was available, which, if sustained, represents an effective screening programme for attending patients.     

Calcium-dependent affinity chromatography of calmodulin on an immobilized phenothiazine.

The reversible, calcium-dependent binding of a calmodulin to phenothiazines has been demonstrated using an immobilized chlorpromazine analog. Calmodulin has been purified from crude extracts of bovine brain utilizing calcium-dependent binding to phenothiazine-Sepharose 4B as an initial affinity-based chromatographic procedure. Chromatography of a crude extract of bovine brain, prepared under non-denaturing conditions, yielded calmodulin contaminated with several other minor EGTA-elutable components. These components were removed by calcium-dependent affinity chromatography on calmodulin-Sepharose 4B and ion-exchange chromatography.     

Effect of geographical factors on the biological productivity of Lake ecosystems: Modeling and forecast

The correlation between the lake ecosystem productivity and geographical and climatic factors and the production of terrestrial vegetation in the catchment area has been described in the form of a dynamic mass-balance model using Lake Krivoe (North Karelia) as an example. A model algorithm has been presented. It is concluded that, with natural year-to-year fluctuations of the biogenic load and the absence of anthropogenic impacts, Lake Krivoe has been preserving the status of an oligotrophic water body for more than 40 years (1968–2013).     

Inhibition of Trypsin-Like Enzymes on Cells with Rhodamine-Aprotinin

Abstract

Aprotinin, a polypeptide inhibitor of trypsin-like enzymes, has been labelled with rhodamine. Rhodamine-aprotinin inhibits trypsin in free solution in an identical manner to aprotinin. Rhodamine-aprotinin binds to trypsin-like enzymes on cells in formaldehyde fixed wax embedded sections. This technique has been used to locate cells possessing trypsin-like enzymes by means of fluorescent microscopy. In the present study we have used this technique to locate tumour cells.     

Paleoecology of Sphenothallus on an Upper Ordovician hardground

A hardground from the Upper Ordovician Dillsboro Formation near Dillsboro, Indiana, U.S.A., preserves an assemblage of encrusting and boring fossils on both top and bottom surfaces. The slab is inferred to have been an undercut ledge, and the dominant fossils of the assemblage, holdfasts of the tube-building worm Sphenothallus and trepostome bryozoans, are prevalent on both sides. The clumping of Sphenothallus holdfasts has been statistically demonstrated using a nearest-neighbor technique. Sphenothallus has also been shown to withstand overgrowth in interactions with bryozoans.     

Influence of pressure on growth of Pseudomonas fluorescens

Summary The effect of increased pressure on the growth of the bacterium Pseudomonas fluorescens has been investigated in an airlift-fermenter (10 l) up to 8 bars. It could be established, that increased hydrostatic pressure has a strong effect on the metabolism of the bacterium.     

Recommendations from the Consensus Conference on Hypertension in the Elderly.

Since 1978 there have been dramatic advances in the understanding of the pathophysiologic features of unstable angina pectoris and in the availability of new therapies of proven efficacy. Coronary artery spasm has been shown to be an important mechanism of acute myocardial ischemia in patients with unstable angina, and coronary thrombosis has been established as an early event in the development of acute myocardial infarction and, possibly, sudden death. Intravenous nitrates and oral calcium antagonists have been made available and are now widely used. Acetylsalicylic acid has been shown to be of benefit. Improved techniques of myocardial preservation and the introduction of percutaneous transluminal coronary angioplasty have modified the surgical management of coronary artery disease.