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.     

Radioimmunoassay of polypeptide hormones using immunochemically coated plastic tubes

A method has been developed for immobilisation of antisera on fresh plastic tubes through an immunochemical bridge. This type of immobilisation has been shown to be more consistent than direct adsorption on plastic. Such immunochemically coated antisera on plastic tube has been used in the development of a noncentrifugation radioimmunoassay. This assay system has been found to be technically as sound as the conventional method.     

Importance of scaling exponents and other parameters in growth mechanism: an analytical approach

The growth process of a living organism is studied with the help of a mathematical model where a part of the surplus power is assumed to be used for growth. In the present study, the basic mathematical framework of the growth process is based on a pioneering theory proposed by von Bertalanffy and his work is the main intellectual driving force behind the present analysis. Considering the existence of an optimum size for which the surplus power becomes maximum, it has been found that the scaling exponent for the intake rate must be smaller than the exponent for the metabolic cost. A relationship among the empirical constants in allometric scaling has also been established on the basis of the fact that an organism never ceases to generate surplus energy. The growth process is found to continue forever, although with a decreasing rate. Beyond the optimum point the percentage of shortfall in energy has been calculated and its dependence on scaling exponents has been determined. The dependence of optimum mass on the empirical constants has been shown graphically. The functional dependence of mass variation on time has been obtained by solving a differential equation based on the concept of surplus energy. The dependence of the growth process on scaling exponent and empirical constants has been shown graphically.     

Effects of variation on extensor elements and operative procedures in patellofemoral disorders

The influence of both insertion and strength/elasticity of each extensor in patellofemoral disorders was fully investigated through a two-dimensional mathematical model analysis in a horizontal plane, in combination with experimental design theory for analyzing mutually correlated influences. In the model, patellofemoral joint profiles projected on a horizontal plane have been expressed as spline functions. Each muscle of the quadriceps has been represented as a string pulled by the respective force; fascias and tendons have been represented by springs. Nonlinear equations have been constructed to represent the forces involved, and then solved by numerical iteration. An analysis of variance was performed on the data derived from a series of simulations, obtaining the following results. The strength of most extensors has been shown to have an influence on the increase in lateral contact force but not patellar translation. The tibial tubercle position has significant influence on both patellar translation and lateral contact force. The quadriceps' insertion on the femur has no influence on patellar translation. The insertion of each extensor on the patella has been shown to have a strong effect on patellar translation but not on contact force.     

Population dynamics of mitochondria. I. A model for the role to ACTH in the degradation of adrenocortical mitochondria

An allosteric substance has been supposed to be present in the adrenocortical cell and to be involved in the degradation of the adrenocortical mitochondria only when it is present in the cytoplasm as a free form. An allosteric effector has also been assumed to be synthesized in the adrenal cortex strongly depending on the ACTH supply. The allosteric effector combines hypothetically with the allosteric substance to form an association product. In its bound form, the allosteric substance is assumed to be inactive in the degradation reaction of mitochondria. With these assumptions a differential equation has been obtained to describe the decay process of those mitochondria. An algorithm has been developed to compute the dynamical fate of the mitochondria in a simple, iterative way. Experimental results on the mitochondrial decay in the rat adrenal cortex after hypophysectomy have been fitted to the differential equation in a satisfactory manner. It has been stressed that the present hypothesis constitutes in its essence a new working hypothesis on the maintenance of adrenocortical mitochondria under normal physiological conditions.     

Perturbation of the chemotactic tumbling of bacteria

The bacterial sensing system has been studied on three levels. First, a quantitative method has been devised for measuring the “action spectrum” of the bacterium in response to a sudden addition of attractant. Second, a technique has been developed for the rapid isolation of mutants defective in the transmission part of the sensing system. Third, a study of the effects of light on the transmission system reveals two components, one which generates tumbling and another which inhibits it.     

Interaction of glycogen synthase of rabbit skeletal muscles with flavin mononucleotide

The effect of flavin mononucleotide (FMN) on the activity of the I- and D-forms of rabbit skeletal muscle glycogen synthase has been studied for the first time. FMN has been shown to inhibit in a noncompetitive fashion the both forms of the enzyme, the D-form being more sensitive to the effect of the inhibitor. It has been shown also that glycogen synthase has three different sites involved in the interaction with inhibitors, namely, and active site, an adenyl nucleotide binding site and a FMN binding site. FMN binding has been shown to occur mostly via the isoalloxasine ring.     

Effect of intraparticle diffusion resistance on apparent stability of immobilized enzymes

The effect of the intraparticle diffusion resistance on the apparent stability of the immobilized enzyme suffering from the first-order deactivation has been studied quantitatively. A general expression for the relationship between the decreasing observed enzymatic reaction rate and the intrinsic enzyme deactivation rate has been introduced. The method to estimate the intrinsic deactivation rate constant also has been proposed. Using the invertases immobilized on a anion-exchange resin, the theory proposed in this work has been verified experimentally.     

Genetic control of migratory behaviour in birds

Although it has long been suspected that biannual migration in birds has a direct genetic basis, only in the last decade have details of the inheritance of behavioural traits such as migratory activity and directional preferences been demonstrated. A model has now been developed to estimate how inexperienced first-time migrants manage to reach their unknown winter quarters on the basis of inherited spatio-temporal programs. Furthermore, in obligate partial migrants the decision to migrate or not has been shown to have a strong genetic base. Migratoriness and sedentariness in partial migrants have been shown to have a high potential for rapid evolution. A recent set of results has suggested that novel migratory habits can evolve in less than 25 years. A possible consequence is that environmental changes, including 'greenhouse' effects, might considerably alter avian migration systems by acting on genetic variation for migratory tendencies.     

二氧化硫污染对植物影响的研究进展

20多年来 ,关于SO2 污染对植物伤害症状、生长发育、生理生化的影响以及伤害机理的研究获得了长足的发展。研究成果应用于大气SO2 的监测和评价 ,以及抗污树种的筛选。对目前刚开始的SO2 与NOx、O3 等复合污染和酸沉降对植物影响的研究 ,将会成为今后研究的主导方向。     

Comparison of characteristic of smooth pursuit in left-handed and right-handed subjects

In a study on healthy young adults with the use of a stroboscopic stimulation, estimation of the efficiency of smooth pursuit has been performed. The influence of manual function asymmetry on smooth pursuit has been studied. It has been shown that markedly right-handed (“strong right-handed”) persons display a high efficiency of smooth pursuit of stimuli moving horizontally in the rightward and leftward directions with velocities of 20°/s and 25°/s. Left-handed persons track similar stimuli, on average, worse than the “strong right-handed” ones. The influence of manual function asymmetry on the dependence of the smooth pursuit efficiency on the moving stimuli direction (left to right or right to left) has not been observed.     

Use of Ranks in Comparisons of Variability in the Non-Normal Populations

A method of analysis for comparing the variability of two samples drawn from two populations has been developed. The method is also suitable for the nonnumeric form of data. A test based on ordered observations for testing the null hypothesis of equality of two variances has been given. The test statistic is a function of the sum of ranks assigned to smaller size sample. Ranking procedure has been modified to depict the variability in the data by the sum of ranks. The null distribution of the test-statistic has been worked out for small samples and it turns out to be chi-square distribution for large samples. The analytical procedure has been explained by a numerical example on the productivity and production of rice and wheat in India from 1950–51 to 1983–84.     

Adenylate cyclase of the causative agent of plague: its purification and properties

Three forms of adenylate cyclase have been detected in Y. pestis: membrane-bound, cytoplasmic and extracellular. Extracellular adenylate cyclase has been purified so as to achieve a homogeneous state, and some of its physicochemical parameters have been investigated. In the process of purification the initial preparation of this enzyme has been subjected to heating at 100 degrees C for 15 minutes, fractionation with ammonium sulfate, and gel filtration on Sephadex G-100. The homogeneity of adenylate cyclase has been confirmed by electrophoresis in 7.5% polyacrylamide gel and precipitation by the plague agglutinating serum. The enzyme has been found to have a molecular weight of 30,000 daltons and to show the optimum activity at pH 7.0-7.2 and at a temperature between 37 and 40 degrees C. Monospecific rabbit serum to the homogeneous preparation of adenylate cyclase has been obtained.     

New perspectives on photosynthetic phosphorylation in the light of a torsional mechanism of energy transduction and ATP synthesis

New perspectives on photophosphorylation have been offered from the standpoint of the torsional mechanism of energy transduction and ATP synthesis. New experimental data on the involvement of malate anions in ATP synthesis in an acid-base malate bath procedure has been reported on spinach chloroplast thylakoids as the model system. The data cannot be reconciled with the chemiosmotic theory but has been shown to be naturally explained by the torsional mechanism. The path of malic acid in the acid and base stages of the experiment has been traced, offering further strong support to the new paradigm. Classical observations in the field have been re-interpreted in the light of these findings. A new concept of ion translocation, energy transduction and coupling at the overall physiological level in photophosphorylation has been presented and a large number of novel experimentally testable predictions have been made and shown to arise as logical consequences of the new perspectives.     

Effect of ion-binding and chemical phospholipid structure on the nanomechanics of lipid bilayers studied by force spectroscopy

The nanomechanical response of supported lipid bilayers has been studied by force spectroscopy with atomic force microscopy. We have experimentally proved that the amount of ions present in the measuring system has a strong effect on the force needed to puncture a 1,2-dimyristoyl-sn-glycero-3-phosphocholine bilayer with an atomic force microscope tip, thus highlighting the role that monovalent cations (so far underestimated, e.g., Na(+)) play upon membrane stability. The increase in the yield threshold force has been related to the increase in lateral interactions (higher phospholipid-phospholipid interaction, decrease in area per lipid) promoted by ions bound into the membrane. The same tendency has also been observed for other phosphatidylcholine bilayers, namely, 2-dilauroyl-sn-glycero-3-phosphocholine, 1,2-dipalmitoyl-sn-glycero-3-phosphocholine, and 1,2-dioleoyl-sn-3-phosphocholine, and also for phosphatidylethanolamine bilayers such as 1-palmitoyl-2-oleoyl-sn-3-phosphoethanolamine. Finally, this effect has been also tested on a natural lipid bilayer (Escherichia coli lipid extract), showing the same overall tendency. The kinetics of the process has also been studied, together with the role of water upon membrane stability and its effect on membrane nanomechanics. Finally, the effect of the chemical structure of the phospholipid molecule on the nanomechanical response of the membrane has also been discussed.     

Purification of a polyphenol oxidase isoform from potato (Solanum tuberosum) tubers

A different expression pattern of polyphenol oxidases has been observed during storage in cultivars of potato (Solanum tuberosum L.) featuring different length of dormancy: a short-dormant cultivar showed, at the end of the dormancy, both the highest polyphenol oxidase activity and the largest number of enzyme isoforms. An isoform of polyphenol oxidase isolated at the end of the physiological dormancy from a short-dormant cultivar has been purified to homogeneity by means of column chromatography on phenyl Sepharose and on Superdex 200. The purification factor has been determined equal to 88, and the molecular mass of the purified isoform has been estimated to be 69 and 340 kDa by SDS polyacrylamide gel electrophoresis and gel filtration on Superdex 200, respectively, indicating this PPO isoform as a multimer. The corresponding zymogram features a diffused single band at the cathodic region of the gel and the pI of this polyphenol oxidase has been calculated equal to 6.5.     

Diagnostic possibilities of magnetic resonance cholangiopancreatography

Studies for 39 patients have been done with the use of a new non-invasive method of observation--MR cholangiopancreatography,--that enables to get a high contrast-enhanced image of the intrahepatic, extrahepatic and pancreatic ducts without administration of the contrast agents and invasive interventions. High diagnostic efficiency of the method has been proved in patients with diseases of bile ducts and pancreas. The observation technique has been optimized and semiotics has been clarified in cases of various diseases that cause on obstruction of the biliferous tracts. The advantages of this method has been showed as compared to invasive roentgenologic methods of examinations.     

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 characteristics of protein hydrolysis on the digestive-transport surfaces of the cestode Eubothrium rugosum and of the intestines of its host--the burbot]

The functioning of different proteinases hydrolysing proteins in a wide pH range, most of which display activity in the alkaline zone of pH, on the digestive-absorptive surfaces of the parasite and host has been investigated. The dynamics of desorption of these proteinases from the intestine of fishes and tegument of cestodes has been studied. It has been shown that the worms possess less proteolytic activity and less capacity for adsorption of proteinases as compared to the intestines of their hosts. The dependence of proteolytic activity of desorbed fractions on the incubation medium temperature has been noted: with the increase in temperature the enzymes, bound closely with the membranes, increase their capacity to hydrolyse proteins. The predominance in cestodes, as compared to the intestine, of easily desorbed fractions D1 and D2 (in the percent ratio of the total proteolytic activity of all fractions) has been detected.