Purification and substrate specificity of BcmI restriction endonuclease

A strain producing the new specific restriction endonuclease BcmI has been found in the Bacillus generum. The enzyme has been purified by chromatography on the blue sepharose, phosphocellulose PII, heparin sepharose. The analogous purification has been obtained when the blue sepharose has been substituted for the orange sepharose, the home produced sorbent. The BcmI enzyme has been shown by the substrate specificity definition to be an isoschizomer of the restriction endonuclease ClaI.     

Inhibitors of the nitrite oxidation of hemoglobin

Different types of active inhibitors of the reaction of nitrite hemoglobin oxidation have been revealed and studied. The dependence of inhibition of methemoglobin formation, on concentration of inhibitors at pH 5.9 and 7.17 has been determined. Differential absorption spectra of the inhibitors in the presence sodium nitrite in UV and visual light has been studied. The values of oxidation-reduction potentials have been estimated. Possible mechanism of action of the inhibitors has been discussed.     

Construction of recombinant plasmids encoding the biosynthesis of the beta-subunit of cholera toxin

The structure of the cholera toxin operon and the location of A and B toxin subunits have been studied by the Southern blot hybridization on filters. The gene coding for the synthesis of the cholera toxin B-subunit has been cloned in the vector plasmid pBR322. The structural gene of A-subunit has been partially deleted by the restriction endonuclease Bal31 digestion. The size of the 250 b. p. deletion has been defined by electron microscopy. The production of the cholera toxin B-subunit in Escherichia coli K12 cells has been studied.     

Epidemiological assessment of the microbial contamination of the breast milk of healthy women

The qualitative and quantitative composition of the microflora of human milk has been studied. The dynamics of the occurrence of different microorganisms constituting the microflora at different periods of lactation has been established. The connection between the appearance of septic purulent infections in infants and the microbial contamination of milk has been revealed. The presence of Staphylococcus aureus in human milk in an amount of 500 microbial cells/ml has been found to constitute no menace to healthy infants.     

The spatial reorganization of the perinucleolar area of hematopoietic cells in human leukemias]

The structure of perinucleolar zone in nuclei of peripheral blood hemopoietic cells has been studied. The cells of human patient with chronic lympholeukemia, chronic myeloleukemia, various forms of acute leucosis have been investigated. The phenomenon of radial strings and border structures has been found in these cells. The features have been revealed by visualization of ribonucleoproteides and lipoproteins. The same process takes place in human lymphocytes after 6-24 h of 3-phosphoglyceric aldehyde stimulation in vitro. A comparative study of morphologic peculiarities of hemopoietic cell nucleolar apparatus depending on cell cycle phase has been performed. The action of cytostatics upon the structure of nucleus perinucleolar zone has been investigated.     

Mapping of phase response properties of monopolar ECG voltages

In the present investigation an attempt has been made to study the phase response properties of monopolar chest lead ECG voltages. Using a generator model of the heart an equivalent circuit of ECG network has been developed. The equivalent impedance between WCT and probe electrode has been determined by reduction techniques. From this equivalent impedance the phasor characteristics of monopolar ECG voltages have been analysed for change in probe electrode locations. The source of the generated voltage, i.e., the heart, will develop a different voltage for its different condition. There will also be a change in impedances. Thus for the normal subject the distribution of the phasor of the ECG voltages will be different from that of the abnormal one. A software tool has been developed to evaluate the relative phase response of ECG voltages. The data acquisition of monopolar ECG records of chest leads V1 to V6 from chart recorder has been done with the help of AutoCAD application package. The harmonic constituents of ECG voltages have been evaluated at each harmonic plane and the phase characteristics have been studied in polar coordinate for normal subjects as well as for a typical case. An interesting result has been observed in typical cases which are indicated in the paper.     

The effect of ultrasound on the antigenic activity of human erythrocytes

The effect of ultrasound (frequency 0.88 MHz, intensity from 0.05 to 1 W/cm2) on alterations in antigenic activity has been investigated in vitro using ABO antigens of human erythrocytes. The existence of threshold doses of ultrasound influence has been found. These doses are shown to be independent of ultrasound intensity. The dependence of the effect on erythrocyte concentration has been established. Individual and group differences in the antigenic resistance to ultrasonic exposure in donors of groups A and B have been revealed. A drop in antigenic activity equal to 97% has been obtained.     

Localization of the DNA segment coding for the synthesis of fraction I on the pYT plague pathogen plasmid]

Fragmentation of the pYT plasmid of the plague pathogen by ten restriction endonucleases has been studied. The evidence has been obtained in support of the possible presence of the movable genetic element containing a HindIII site within the plasmid pYT. The gene encoding the I fraction of the plague pathogen has been cloned. The physical map of the pYT plasmid has been constructed with the use of restriction endonucleases BamHI, XhoI, BstEII, SmaI, EcoRI, and HindIII. The fragment of the plasmid DNA coding for the synthesis of the plague pathogen fraction I has been mapped.     

Sampling Schemes for Studying Growth of Children

Efficiency of linked cross-sectional scheme has been compared with pure longitudinal schemes for generalised estimation of norm relaxing the condition of constancy of variances. The relevant theory of estimation has been developed and the expression for the optimum estimators alongwith their variances have been derived. The percentage gain in efficiency has been calculated. It has been observed that for higher values of Q, percentage gain in efficiency of proposed scheme over cross-sectional is very high.     

Micrococci in the skin microbiocenosis of the breasts. Ecologic characteristics of the colony

The ecological characteristics of the micrococcal community on the skin of the mammary glands of nulligravidae, pregnant and puerperant women have been studied. The species composition of the community, the population size and occurrence of each species, its participation in the dominant structure of the community have been determined. The comparative evaluation of its types has been made. A decrease in the dominating role of M. luteus in pregnant and puerperant women has been established. The tendency towards the normalization of the structure of the community in the postnatal period has been established.     

Mode of action of intercalators: a theoretical study

Mode of action of some intercalators has been theoretically investigated on the basis of quantum mechanical perturbation method. Energies of H-bond interaction between drug chromophore and base pairs have been calculated in all possible orientations. The stacking energy has also been calculated with the base pairs. The effect of these interactions on specific recognition has also been discussed. On the basis of these studies, a model for the interaction of these drugs has been proposed. This explains the relative activities of acridine intercalators and satisfies the experimental observations.     

Persistence of bacterial pathogens as a physiological phenomenon

The complex ecosystem of humans and microbes has been presented as an associative symbiosis based on a mutual support of symbionts with different consequences for them. Conditions for the persistence of bacteria have been defined: their resistance to environmental factors, antagonism in biocenosis, and stability to withstand host defense mechanisms. The key role of bacterial peptidoglycan has been defined for their survival in an infected organism, and the classification for persistent mechanisms of pathogens has been given. The group of bacterial secreted protease providing microbial resistance to defense factors of the organism has been described. Host colonizing resistance has been presented as a physiological regulatory system controlling bacterial penetration into an organism. Regulatory mechanisms for bacterial persistence have been discussed.     

Study of the interaction of main potato glycoalkaloids in inhibition of immobilized butyryl cholinesterase

The interaction of main potato glycoalkaloids alpha-solanine and alpha-chaconine in inhibition of horse serum butyryl cholinesterases immobilized on the pH-sensitive field-effect transistors has been investigated. The method of isobol diagram of Loewe and Muishnek has been used for interpretation of results. It has been shown the alpha-chaconine inhibits the immobilized bytyryl cholinesterases more strongly than alpha-solanine, and their mixture has the addition effect.     

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.     

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.     

Sensitivity of the rabbit embryonal Leydig cells to the action of different pituitary hormones

Leydig cells reaction of rabbits testis to choriogonin action has been investigated during the prenatal period of ontogenesis. It has been found, that these cells sensitivity to the hormones studied has been detected at the early stages of embryogenesis. The specialization of Leydig cells response to choriogonin, thyrotrophin and prolactin in the process of prenatal period has been shown.     

The organization of capsaicin-sensitive visceral afferent systems

It has become clear that a number of neuropeptides are found in sensory nerves, some of which have been identified in visceral afferents. The best studied peptide is substance P, which has been localized in a population of capsaicin-sensitive visceral afferents. It has been established that there are a varied proportion of substance P-containing afferents in different visceral structures. In general, the peripheral termination of these nerves is around blood vessels. The central terminations of visceral afferents are in laminae I and V in the dorsal horn of the spinal cord. Substance P has been localized in these laminae and appears to be capsaicin-sensitive and therefore of sensory origin. Recently, substance K, which is derived from the same gene as substance P, has been found in visceral structures. Calcitonin gene-related peptide has been found in certain viscera to be contained in capsaicin-sensitive nerves. The contribution that other peptides make to visceral afferent innervation is not known.     

Improving a process of cultivation of bifidobacteria in a bioreactor to obtain lyophilized seed culture

The parameters of the cultivation process and the characteristics of the culture growth have been analyzed. The phases of the population growth have been determined. The existence of short stages differing in the physiological state of the cells, their resistance to damaging factors and metabolic activity within the deceleration phase of the growth of bifidobacteria has been experimentally substantiated. To harvest the biomass, the period of the completion of the cultivation process has been chosen. The lyophilized seed culture in which a high percentage of viable cells is preserved for one year has been obtained.