Comparison of lipase-catalysed esterification in supercritical carbon dioxide and in n-hexane

Summary Oleic acid esterification by ethanol has been performed by an immobilized lipase fromMucor miehei in supercritical carbon dioxide and in n-hexane as solvents. In both media, determination of apparent kinetic constants has been achieved and influence of water content has been shown to be different due to various rates of water solubilities. Stability of the lipase has been proved to be correct and similar in both solvents. Inhibition by ethanol excess has been found but is greater in n-hexane. That can explain the higher initial velocities obtained in supercritical carbon dioxide for the highest ethanol concentrations.     

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.     

Testing of G----A mutation in position 110 of a minor intron of beta-globin genes in patients with thalassemia in Azerbaijan

A point mutation G-A in the 110 position of the beta-globin gene small intron has been revealed by cloning and sequencing from the material of a homozygote beta-thalassemia patient in Azerbaijan. In the present study two allele-specific oligonucleotide probes for testing the mutation have been synthesized. Assessment frequency of the mutation among the beta-thalassemia patients in Azerbaijan has been performed with the use of the amplified beta-globin gene fragments obtained by using the thermostable DNA-polymerase from T. thermophilus with the subsequent dot-hybridization in gel of the amplified material with the oligonucleotide probes. The possibility to test the mutation by hybridization of the oligonucleotide probes with the donors and beta-thalassemia patients restricted genomic DNA has been analyzed. Only one of 50 thalassemia alleles of beta-globin genes under study has been shown to possess the mutation mentioned.     

Dependence of a drop in blood pressure in pulmonary circulation and in the right heart on dosage of isosorbide dinitrate]

An effect of isosorbide dinitrate on blood pressure values in the pulmonary circulation and the right heart has been investigated in 25 patients with a history of the first transmural myocardial infarction. Group I including 12 patients has been given 5 mg isosorbide nitrate in a 60-minute intravenous infusion while group II of 13 patients has been given 10 mg of the drug in the same way. Both groups have been matched in clinical data and blood pressure value in the pulmonary circulation which has been normal. Pulmonary blood pressure has been measured with Swan-Ganz catheter prior to the administration of drug, and 15, 30, 45 and 60 minutes following an infusion. Isosorbide dinitrate in a dose of 5 mg did not decrease blood pressure in the pulmonary circulation statistically significantly. The differences in blood pressure falls did exceed 9%. Filling pressure in the right ventricle did not change either while systolic blood pressure decrease by 16.6%. A double dose of isosorbide dinitrate reduced blood pressure in the pulmonary artery by about 1/3 of the baseline value, and blood pressure in the right ventricle (mean right atrial pressure) by 57.2%. Both systolic and diastolic arterial pressures were reduced. Isosorbide dinitrate reduced blood pressure in the pulmonary circulation in patients who underwent myocardial infarction, and hypotensive effect has been dose-related. A reduction in the right ventricular filling pressure has been a one of important mechanisms decreasing pulmonary pressures.     

Degradation of polysaccharides and lignin in wood ozonation

Ozonation has been considered as a method for the pretreatment of plant biomass to obtain cellulose and monosaccharides. Ozone consumption by aspen wood with various moisture contents has been investigated. We have considered the gradual transformation of the substrate: wood to ozonated wood to cellulose-containing product (CP) to holocelluloze (HC) and to cellulose. Yields of ozonated wood (OW), the (CP), water-soluble ozonation products, HC, and cellulose have been determined. The lignin content in the CP has been estimated. Both HC and cellulose samples have been studied by IR spectroscopy. The degree of polymerization and molecular mass distribution of cellulose obtained from ozonated wood have been determined. It has been shown that wood destruction by ozone is accompanied by degradation of lignin, hemicelluloses, and cellulose.It has been found that physicochemical properties of cellulose obtained from ozonated wood can be regulated by the variation of the initial moisture content in the substrate. Both molecular ozone and radical species, which are generated in the course of ozone reactions with water present in the substrate structure, participate in wood destruction.     

The effect of oligomycin on rat liver mitochondria respiring in state 4

It has been found that oligomycin inhibits up to at least 50% state-4 mitochondrial respiration. A time dependence of oligomycin inhibition has been shown. A titration curve for state-4 respiration of sigmoidal profile has been presented. The possibility of misreading this oligomycin effect, so far never reported, has been excluded by evaluating the quality of mitochondrial preparations used in respect to their morphological, functional and electrochemical properties. The conclusion has therefore been put forward that the most part of respiration in steady-state-4 is driven by ATP synthesis.     

Intake assessment of L-ergothioneine in some European countries and in the United States

L-ergothioneine is an amino acid synthetized by fungi and mycobacteria that cannot be synthesized by other species. It has been detected in plants, animals, and the human body. In the last few years, it has been recognized as a good antioxidant and, recently, it has also been related to other properties besides antioxidant properties. Even though few studies on the toxicity of L-ergothioneine have been carried out, evidence suggests that L-ergothioneine is not harmful to health. Considering that L-ergothioneine has increasingly been linked to positive effects on human health, coupled with the fact that it seems to be safe for human consumption, this molecule may be suitable for use as an ingredient in foods. On the other hand, despite the positive effects reported for this molecule, no estimate of L-ergothioneine intake has been carried out until now. Thus, the aim of this work is to estimate the intake of L-ergothioneine through food consumption of several European countries and the United States. Values were estimated by using the deterministic and probabilistic approach. Results show that the populations with the highest intake of L-ergothioneine correspond to Italian population, both for children and adults.     

Differences in Conformational Behavior of ATA and TAT Sequences in Single Strand DNA Trimer

Abstract

The conformational behavior of single strand (ss) TAT and ATA trimers of DNA have been studied by computational chemistry tools including CICADA software interfaced with AMBER molecular mechanics and dynamics. The Single-Coordinate-Driving (SCD) method has been used in conjunction with molecular dynamics simulated annealing. It has been revealed that the conformational flexibility of each sequence differs substantially from the other one. Four common conformational families have been found for both trimers. These are: helical, reverse-stacked (base 3), half-stacked (base 3), reverse-stacked (base 1). However, the energies of conformers representing the families are different for both the studied systems. An additional conformational family, bulged, has been found for ss(ATA), while ss(TAT) has been found also in half-stacked (base 1) conformation. In general, ss(TAT) exhibits a higher number of low energy conformations while ss(ATA) shows one interesting low energy conformational interconversion between reverse-stacked (A3) family and half-stacked (A3) family. The high conformational variability of the trimers has been confirmed by flexibility analysis and by molecular dynamics simulations, which have also shown the conformational stability of single conformational families. It has been concluded that the methodology used is able to provide a very detailed picture of the conformational space of these molecules.     

Effect of corticosteroids on the fluorescence of aniline naphthalenesulfonate in mitochondria after changes in temperature

The influence of corticosteroid hormones and cholesterol on the anilinonaphthalenesulfonate (ANS-) fluorescence in the rat liver mitochondria at different temperatures has been studied. The fluorescence intensity has been found to decrease by warming and increase by cooling the mitochondrial suspension. The steroids studied in proportion to their hydrophobic nature decreased the ANS- fluorescence at 25 degrees C and increased it at 5 degrees C, i.e. at higher and lower temperatures of the phase transition of the membrane lipids. It has been concluded that steroid hormones influence the fluidity of the mitochondrial membranes.     

Differences in conformational behavior of ATA and TAT sequences in single strand DNA trimer.

The conformational behavior of single strand (ss) TAT and ATA trimers of DNA have been studied by computational chemistry tools including CICADA software interfaced with AMBER molecular mechanics and dynamics. The Single-Coordinate-Driving (SCD) method has been used in conjunction with molecular dynamics simulated annealing. It has been revealed that the conformational flexibility of each sequence differs substantially from the other one. Four common conformational families have been found for both trimers. These are: helical, reverse-stacked (base 3), half-stacked (base 3), reverse-stacked (base 1). However, the energies of conformers representing the families are different for both the studied systems. An additional conformational family, bulged, has been found for ss(ATA), while ss(TAT) has been found also in half-stacked (base 1) conformation. In general, ss(TAT) exhibits a higher number of low energy conformations while ss(ATA) shows one interesting low energy conformational interconversion between reverse-stacked (A3) family and half-stacked (A3) family. The high conformational variability of the trimers has been confirmed by flexibility analysis and by molecular dynamics simulations, which have also shown the conformational stability of single conformational families. It has been concluded that the methodology used is able to provide a very detailed picture of the conformational space of these molecules.     

Identification in various chlorate-resistant mutants of a protein involved in the activation of nitrate reductase in the soluble fraction of a chlA mutant of Escherichia coli K-12

We report some properties of Protein PA which has been isolated from the soluble fraction of a chlB mutant after anaerobic growth in the presence of KNO3. This protein has been identified by its capacity to reactivate nitrate reductase present in the soluble fraction of a chlA mutant by the complementation process. The presence of active Protein PA in the chlB mutant is independent of the presence of oxygen or of nitrate during growth. In contrast, the addition of sodium tungstate to the growth medium leads to the formation of inactive Protein PA which is not able to activate nitrate reductase in the chlA-soluble extract by complementation. Inactive Protein PA has been quantitated immunologically. The partial purification of Protein PA has been achieved from various chlorate-resistant mutants (chlA-chlG). The establishment of particular complementation systems comprising the soluble extracts of chlA or chlB mutants and partially purified Protein PA from soluble fractions of different chlorate-resistant mutants, has allowed the quantitative estimation of this protein. The analysis by 'rocket immunoelectrophoresis' using an antiserum specific for Protein PA has shown that inactive Protein PA is present in approximately equivalent amounts in the chlA, chlE, chlG and chlD mutants.     

Lipid peroxidation of skeletal muscle: an in vitro study

The process of lipid peroxidation of skeletal muscle has been examined in vitro by monitoring the autoxidation of skeletal-muscle homogenates. Skeletal-muscle tissue has been shown to have considerable capacity for autoxidation and the process has been found to be initiated by a free-radical-mediated mechanism, critically dependent on the presence of free iron in the homogenate. The initiating radicals have not been firmly identified, but the results suggest that neither superoxide or hydroxyl radicals are involved. An in vitro technique for assessment of the antioxidant capacity of muscle tissue has also been developed which is capable of demonstrating differences between muscle tissues with differing vitamin E contents.     

Comparative membrane locations and activities of human monoamine oxidases expressed in yeast

A 3 kb cDNA coding for rat liver S-adenosylmethionine (AdoMet) synthetase has been isolated. The M_r of the protein has been unequivocally determined by cDNA sequencing and enzyme purification on a thiopropyl-Sepharose column. The length of the mRNA 5′ non-coding region has been defined by primer-extension analysis. The rat liver cloned cDNA has been also used to detect S-adenosylmethionine synthetase mRNA in human liver.     

Protein crystalloids in the stroma of bean plastids

Summary The formation of protein crystalloids in the stroma of bean plastids has been studied. It has been shown that, besides crystallization of the protein already present induced by water loss (which cannot be inhibited by chloramphenicol), the crystalloids also appear when the leaves are fed — but only in light — with very low concentrations of sucrose or glucose for one or two days. In this case their appearance is completely inhibited by simultaneous treatment of the leaves with chloramphenicol but not with cycloheximide. The process of crystalloid formation and disappearance has also been studied. The possibility of their removal from the plastids into the cell vacuoles has been followed and discussed.     

Determination of Water Stress of Eucalypts in the Field

Abstract

Two methods for determining plant hydrature in the field have been tested on Eucalyptus viminalis Labill. and E. dalrympleana Maiden one-year-old seedlings. The parameters selected are the physico-chemical properties of sap and the diffusion pressure deficit of leaves. Before extracting sap, leaves have been subjected to two different preliminary treatments to improve permeability of cellular membranes, viz. chloroform and liquid nitrogen treatments, the latter being chosen since it was quicker. Sap has been obtained by espressing at 272 Atm., then filtered and analyzed. Diffusion pressure deficit has been determined by equilibration with vapour. A series of samples has been placed in moist chambers with known water potential until equilibrium has been attained. DPD corresponds to the water potential of the chamber where the sample neither gains nor loses water.     

藻红蛋白在微乳液中的增溶溶解

本文研究了藻红蛋白在油包水微乳液的紫外吸收和荧光光谱,结果表明,含藻红蛋白的阳离子表面活性剂的微乳液的光谱与其水溶液的光谱不同,说明藻红蛋白在这样的微环境中变性,与此相反,含藻红蛋白的阴离子表面活性剂的微乳液的光谱与其水溶液的相应光谱的特征峰相同,说明藻红蛋白在阴离子表面活性剂的微乳液中没有变性。本文进一步研究了含藻红蛋白的阴离子表面活性剂的微乳液在不同含水量时蛋白质的稳定性。并根据蛋白质的大小和     

Determination of amylase activity in bovine serum and its association with the Ami and Amll loci

Amylase activity has been estimated in the sera of 213 cattle by an amyloclastic method with potato amylose as the substrate with the addition of CaCl₂. The method has been developed from that of Street and Close to overcome the problems of the high colour of bovine serum which would otherwise interfere with the assay. A relationship has been found between the serum amylase genotype detected on starch-gel and the total enzyme activity. The enzymes AmI-B and AmII-B in homozygous combinations have been found to have the highest activities. Age of animal has no significant effect on the total enzyme activity. Activity has been investigated in sera from three separate cattle populations and it has been found to be a highly heritable character. Heritability estimates of 49 % and 39 % by sib analysis and 75 % by the twin method have been obtained.     

Evaluation of biocompatibility of apatite-wollastonite ceramics in fibroblast cultures

The aim of this work has been to test the biocompatibility of four bioactive, gel derived glass-ceramic materials of CaO-PO2-SiO2 system, modified by addition of boron, aluminum and magnesium compounds. We have examined the growth, collagen synthesis, adhesion and morphology of NRK rat fibroblasts cultured in direct and indirect contact with biomaterials. The growth of cells cultures has been quantified by two methods: [3H]thymidine incorporation and direct counting of cells. The level of collagen synthesis has been used as a parameter describing metabolic activity of cells. Cellular morphology has been assessed following 24 h and 4 days of culturing cells on biomaterials by using SEM and confocal microscopy, respectively. Additionally, in order to obtain information about the attachment of cells to substratum the presence of focal contacts has been examined. The results of all the experiments have demonstrated that none of the materials under study significantly altered cellular functions that were tested. This indicates that additions of MgO, Al2O3 and B2O3 have not induced cytotoxicity of the materials under study. This qualifies them for further in vivo experiments.     

The role of phenylacetic acid in biosynthesis of penicillin amidase in E. coli

For improved biosynthesis of penicillin amidase by E. coli, NCIM 2400, the participation of different carboxylic acids and polyols has been studied in association with the effect of phenylacetic acid. A modified defined medium has been devised for this purpose.