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At least 1,099 records · Page 61Linked to original sources
PubMed1989

[Transduction and conjugation transfer of the pXO2 plasmid in Bacillus anthracis].

The plasmid pXO2 determining the capsule synthesis has been shown to be transfered into the cells of different strains of Bacillus anthracis (STI-1, Sterne, KM33, KM35) by the transducing bacteriophage CP54ant and by mobilization by pAM beta 1 replicon with the frequencies, consequently, n.10(-8) and n.10(-7). The optimal parameters for the selection of clones having acquired the pXO2 plasmid have been defined. Mobilization for conjugational transfer has been demonstrated for the plasmid pXO1 coding for the production of Bacillus anthracis toxin. The dramatic increase of virulence for white mice has been registered for Bacillus anthracis strains having acquired the pXO2 plasmid replicon.

Animals↗
PubMed1989

[Retinoic acid modification of cell culture used for reproduction of enteropathogenic viruses].

The 0.001-0.005% retinoic acid injection into the growth cultural medium of prime and continue cell cultures 12-24h before inoculation considerably raised the cell sensitivity to animal entero- and coronaviruses. The entero- and coronaviruses concentrations in cultural medium increased by 10(1.58) and 10(1.68)TCID 50/1.0 respectively. The optimized parameters of the cell culture processing for the enteropathogenic viruses reproduction improvement are proposed.

Animals↗
PubMed1989

[The laser therapy of rheumatoid arthritis].

About 300 patients with rheumatoid arthritis (RA) underwent multimodality treatment including laser radiation of varying wavelengths. Use was made of helium-neon, infrared, argon and helium-cadmium lasers. A new method of combined laser therapy by radiation of helium-cadmium and helium-neon lasers is described. A scheme of optimal parameters and types of laser radiation recommended for the treatment of different clinical varieties of RA is provided.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1989

[Damper osteosynthesis using an external perosseous fixation device].

The authors substantiate the expediency of improving osteosynthesis with apparatuses of perosseous external fixation on the basis of electromechanical principles making use of statistically reliable results of 58 chronic experiments on animals, 27 stand studies on the tibia of cadavers and 207 dynamic clinical observations employing quantitative results of clinical, roentgenomorphometric, electrophysiologic, biomechanical and histomorphological studies. Optimal parameters of the rigidity of fixation for early restoration of the properties of elasticity and strength of the injured bone are determined. Dampered external osteosynthesis in the treatment of open comminuted fractures of the bones of the crus reduced the mean periods of in-patient treatment and consolidation of the fractures by 27-34. 5% and the frequency of complications and unsatisfactory outcomes by 75%.

Animals↗
PubMed1989

[Complex laser therapy of bacterial destruction of the lungs in children].

The complex laser therapy with the use of a helium-neon laser was employed in 115 patients with bacterial destruction of the lungs at the age of from 3 mos to 14 years. The indications for endothoracic, external and intravascular laser therapy and their combination are substantiated. The calculations of the optimal parameters of laser influence, depending on the stage of the disease and optical characteristics of the damaged lung surface, are presented.

Adolescent↗
PubMedDate not supplied

[Specific and nonspecific components in the neurohumoral link of the conditioned food-refusal reflex in the edible snail].

On snails, the action was studied of hemolymph of donors with conditioned food refusal reflex on acquisition of the same habit by intact snails-recipients in case of coincidence or of difference of conditioned stimuli in donors and recipients. Specific component of the facilitating effect was distinctly manifest at selection of optimal doze of hemolymph and depended on the season. At non-optimal parameters of the experiment the specific component of the facilitating effect was masked by the non-specific one, or an inhibitory effect took place. The data obtained testify to multicomponent composition of the neurohumoral link in the mechanism of conditioned reflex formation.

Animals↗
PubMed1988

[Isolation and various properties of the lytic enzyme preparation from Streptomyces griseus].

Certain optimal parameters were determined for production of a pure enzyme preparation of the GIOx type from S. griseus by precipitating the enzymes from concentrated fermentation broth filtrate. Antibacterial spectrum of the preparation is comparatively narrow. Still, it showed high lytic activity against streptococci and staphylococci. Investigation of the preparation with the electrofocusing technique revealed that the main lysing component was a protein fraction with its isoelectric point within 8-10.5.

Acetone↗
PubMed1987

[Adsorption of antigens K88 and K99 on aluminum hydroxide gel].

Studied was the effect of the pH value of the medium, of the concentration of the antigen and the adsorbent on the adsorption of K 88 and K 99 on aluminium hydroxide-gel. Use was made of strains O 45:K 88 and O 14:K 99. The optimal parameters of pH and the concentration of aluminium oxide as well as of aluminium hydroxide-gel as an adjuvant, substantiating the maximum adsorption capacity of the latter with regard to the two Escherichia coli antigens used. Established was the maximum amount of the antigens which could be adsorbed by as much as 1 cm3 of aluminium hydroxide-gel. According to the authors such amount could serve to indicate the way how to produce effective preparations to be deposited with the two-antigen adjuvant.

Adsorption↗
PubMed1988

[Optimization of oxytetracycline biosynthesis].

It was shown that rising of temperature up to 30 degrees C at the stage of the oxytetracycline-producing organism growth promoted acceleration of the culture growth rate and increasing of the antibiotic concentration by the 114th hour of the biosynthetic process. For the apparatus used in the study optimal aeration and agitation conditions were developed. To provide optimal parameters during biosynthesis of oxytetracycline, it was recommended to use the aeration rate of 1 v/v.min and the specific mechanical power for mixing of not less than 1 kW/m3.

Aerobiosis↗
PubMed1986

Comparison in rabbits of chole-scintigraphic properties of several 99mTc-IDA derivatives.

Pathways and kinetics of excretion were compared to four 99mTc-IDA derivatives in healthy rabbits of both sexes. Assessment of differences between the compounds was based upon: plasma clearance, characteristics of time-activity curves measured scintigraphically over the liver (time of the peak Tmax; time for decline of activity to half the peak value-T50%), and hepatocytic mean transit time (MTT) as derived after deconvolution of the hepatic time-activity curve. Hepatocyte transit time was short and similar to 99mTc-complexes of Mebrofenin, 2,4-diethyl IDA (HEPIDA) and 3-iodo-2,6-diethylphenylcarbamoylmethyliminodiacetic acid (JODIDA); it was evidently longer for 99mTc-p-butyl-IDA (BIDA). 99mTc-HEPIDA displayed significant urinary elimination; the remaining three compounds were excreted practically completely via the biliary route. It is concluded that optimal parameters were displayed by 99mTc-Mebrofenin and 99mTc-JODIDA.

Aniline Compounds↗
PubMed1985

[Increased transformation ability of Escherichia coli strains carrying the plasmid pLD4].

The effect of resident plasmid pLD4, a derivative of plasmid Hly241, on transformability of the host bacteria cells has been studied. Plasmid pLD4 was transferred into the different strains of E. coli subsequently transformed by the DNA of plasmids pBR322, pBR325, pAL-R2, pMB9. The majority of strains harbouring pLD4 obtain the increased ability to be transformed as compared with the ability of isogenic plasmidless strains. The similar but less expressed effect was conferred by the plasmid Hly241. Another hemolytic plasmid Hly195 and its derivatives, carrying the different transposons, as well as plasmid F' tet Hly did not increase the transformability of host bacteria. The optimal parameters for transformation of the strains harbouring pLD4 and plasmidless strains coincide, but the number of competent cells is considerably higher for plasmid containing strains, due to preliminary results.

Escherichia coli↗
PubMedDate not supplied

[Autonomic correlates of the formation of a functional self-stimulation system].

Capability of intracerebral electrostimulation to serve as an unconditioned reinforcing stimulus in classical conditioning was studied in rabbits. Changes of such vegetative characteristics as respiration frequency and ECG were taken as criterion of conditioned response (CR) elaboration. In preliminary experiments, optimal parameters of stimulation maintaining the highest level of instrumental self-stimulation behaviour were found for each of the animals. Isolated presentation of the unconditioned reinforcing stimulus led to the increase of respiratory rate. Such kind of stimulation induced tachicardia in 5 animals, bradicardia in 3 ones, and in the remaining 6 rabbits a biphasic reaction was observed with initial tachicardia changing for bradicardia. Reactions were taken as CRs if they were similar to those to the unconditioned stimulus and appeared at the moment of omitted reinforcement. After 10 pairings of conditioned sound stimulus with positive reinforcement, CR changes of the two vegetative parameters were observed in 21,4 per cent of cases. After 40 pairings CRs were observed in 87,5 per cent of trials for cardiac and in 78,5 per cent cases for respiratory components. The results obtained confirm the idea of validity and efficiency of intracerebral stimulation of self-stimulation zones as a factor of positive reinforcement.

Animals↗
PubMed1984

[Multiplication of Aujeszky's disease virus MK-25 on chick fibroblast cell cultures].

Attempts were made to produce multilayer cell cultures of chick fibroblasts in a RC-42 roller as well as to replicate in these the Aujezsky's disease virus. Used were fibroblasts of 10-11-day-old chick embryos. The cells were obtained in a closed system after the classic method with an electromagnetic stirrer and a 0.3 percent trypsin in phosphate buffer, having no Ca and Mg ions. Hank's solution was used as a nutrient growth medium, containing 0.5 per cent lactoalbumin hydrolysate and calf serum at pH 7.4-7.6. Both the cell growth and the cytopathic effect of the virus in the stationary and the roller cultures were carried out simultaneously through microscopy, and the evaluation was made after a fourgrade system. It was found that proper cell cultures or chick fibroblasts could be obtained under the following optimal parameters: volume of nutrient medium--200 cm.3; amount of normal inactivated calf sera--10 per cent; and speed of rotation--10 r. p. m. The titer of the virus was found to surpass by 2 logarithms the virus in the stationary cell cultures for a twice shorter period of cultivation.

Animals↗
PubMed1980

[The effect of active substances on nerve fiber regeneration in nerve tissue cultures].

Explants of the ganglion trigeminale from chick embryos and hippocampi from embryonal rats were incubated in maximowchambers with semisynthetic media. The different parts of nervous tissue were influenced experimentally by addition of biological extracts and by substances with known composition. The regeneration of nerve fibers was investigated by the index of growth. The growth index was calculated from the ratio of nerve fibre index of the test cultures to that of the influenced cultures. Under these conditions biological extracts enhanced the growth of nerve fibres. In the same way the growth of nerve fibres was statistically significantly stimulated by substances with known composition of aminoacids, orotic acid, sodium orotate and cyclic monophosphates. A stimulating effect of cyclic guanosinmonophosphate seems to exist only in CNS explants and only in young fetal rats and consists in an increased migration and proliferation of cells as well as in the formation of fibres from neuroblasts. The investigations gave strong evidence for the in vitro testing to be very useful in studies of nerve fibre regeneration. However the choice of suitable reference systems, suitable quantitative parameters, optimal concentration and periods of application of effective substances and the age of the animals are of fundamental importance for the evaluation of the results. Experiments regarding the stimulation of the differentiation of neurons and the growth of nerve fibres are of practical clinical and therapeutical interest.

Animals↗
PubMed1976

[Use of the indirect hemagglutination test in the study of ornithosis. I. Hemosensitizing activity of ornithosis phosphlipid antigen and a method of performing tests with it].

A possibility was shown of using the phospholipid group-specific antigen of the ornitosis causative agent in the capacity of a hemosensitin for conducting the indirect hemagglutination test (IHAT). There was revealed a direct proportional relationship between the sensitizing activity and the complement fixing properties of the antigens obtained. A method of sorption of this antigen on the tannin-treated erythrocytes and the optimal parameters of conducting the test with it were elaborated. A sufficiently high sensitivity and specificity of the IHAT was revealed as a result of parallel titration of hetero-and homologous sera in the complement fixation test and in the IHAT. The suggested test can be successfully used for the diagnosis of ornithosis.

Antigens, Bacterial↗
PubMed1981

[The development of nervous tissue to experimental manipulation in vitro (author's transl)].

Explants of nervous tissue (CNS: hippocampus from fetal rats, telencephalon and PNS: ganglion trigeminale from chick embryos) were cultivated in maximow chambers. Biological extracts (brain and embryo extract) or chemical agents (aminoacid mixtures and peptides with known sequence of amino acids) were tested. Biological extracts and aminoacid mixtures stimulated the differentiation in PNS and CNS cultures. A stimulating effect of peptides seems to exist only on PNS explants. The fundamental importance of suitable reference systems, parameters, optimal concentrations and periods of application of effective substances for the evaluation of the results is discussed.

Amino Acids↗
PubMed1981

Compound action potential reconstructions and predicted fiber diameter distributions.

Electrophysiologic and anatomic studies on cat saphenous nerve were combined with CAP modelling and computer analysis. Myelinated nerve FD histograms were compiled from transverse section photomicrographs using various estimates of diameter, primarily those based on fiber cross-section area. The FD histogram and biophysical parameters were more important in the CAP reconstruction model than the SFAP parameters. The biophysical parameters were optimized to obtain best fits between recorded and reconstructed CAPs. Finally, the inverse of the CAP reconstruction model was used to predict FD histograms from optimized biophysical parameters and recorded CAP waveforms under carefully controlled experimental conditions. The results of these studies provide an empirical basis for relating volume conducted CAPs to the anatomic and physiologic characteristics of nerve fiber bundles. More accurate histologic methods and procedures for estimating biophysical parameters are needed before this approach to the inverse problem can be pursued further. The major advantage of estimating FD distributions rather than CV distributions is that the anatomic data are truly independent reference standards for evaluating the results.

Action Potentials↗