Development of protoplasts of Streptomycetes on media favoring the regeneration and formation of L-forms

The protoplasts of three Streptomyces species and their regenerative ability were studied using light microscopy. When Streptomyces lividans and S. erythraeus protoplasts are cultivated on regeneration media, their regeneration is not synchronous during the first day; some protoplasts revert to yield the mycelial form and also L-forms of these cultures are produced. If the protoplasts are transferred to a medium inducing L-forms, they grow and multiply for a long time with the production of L-form colonies. This process is maintained if S. lividans L-form cells are passaged on the medium inducing L-forms, but the protoplasts revert to yield the mycelial form on the regeneration medium.     

Relation between the morphogenesis of Xanthomonas rubrilineans and biosynthesis of aminopeptidase in the process of growth and development of its producer]

The dynamics of growth and development of Xanthomonas rubrilineans, a culture producing intracellular aminopeptidase, was studied. A difference between the growth rate determined by intensity of the total biomass accumulation and the rate of the culture multiplication was found. The difference was due to the presence of two phases in the culture development during the exponential growth: the phase of increasing the linear sizes of the cells and the phase of the culture intensive multiplication. The most intensive synthesis of aminopeptidase was observed during the phase of increasing the linear sizes of the cells. The dynamics of consumption of the main sources of carbon and nitrogen by the culture was investigated.     

Ontogenetic aspects of individual characteristics of functional brain asymmetry in the perception of emotions

Studies have been made on individual variations in perception of speech emotional information by 7-16-year children. Significant differences between subjects from various age groups were found concerning the correct recognition of emotions, the degree of brain asymmetry and domination type. The exactness of emotional recognition increases with age, while the degree of asymmetry becomes lower, the right hemisphere domination becoming more stable in processing of speech emotional information. With age, individual type of asymmetry turns to the specific one, reflecting asymmetry formation during evolution.     

Radioimmunologic and radioreceptor studies of the pharmacokinetics of the enkephalin analog dalargin in man

Pharmacokinetics of dalargin, an opioid hexapeptide, was investigated on 7 males by two approaches. Dalargin radioimmunoassay was performed using a highly specific antiserum reacting only with the whole molecule. In radioreceptor assay lyophilized rat brain membranes containing opiate receptors were used. 2-6 min after intravenous introduction of 1-10 mg dalargin, immunoreactive dalargin blood concentration was lower than 0.5 ng/ml. The results of radioreceptor assay were presented as a biexponential curve with a fast main phase of activity changes (90%, characteristic time 1.5-5.0 min) and a slow "clearance" phase (10% of the substance, characteristic time 85-200 min). Prolonged presence of receptor-active substances in the blood can be attributed to the products of dalargin degeneration, namely its N-terminal penta- and tetrapeptides.     

Individual features of rat behavior: manifestations of anxiety

Motor agitation developing in some white rats during painful stimulation of other individual decreases under the action of phenasepam (the most effective drug used in clinic in cases of neurotic alarm). This effect is accompanied by strengthening of tendency to reside in closed space. After phenasepam injection, increased not goal-directed motor activity developing against the background of reduced alimentary reactions also decreases in a part of grey rats selected by their ability to extrapolate, while their alimentary behaviour intensifies. Thus, initial peculiarities of behaviour i.e. enhanced motor activity not directed to fulfillment of the above forms of inborn behaviour (residing in closed space and eating) may be considered as a manifestation of anxiety. In this case, these forms of behaviour have a defensive function.     

Antibiotic production by variants of Penicillium chrysogenum isolated after protoplast formation and exposure to mutagens at the protoplast stage

A procedure for protoplast formation in the penicillin-producing organism Penicillium chrysogenum was developed. The yield of the protoplasts was high, the protoplasts were stable and capable of regeneration. Two types of the protoplast regeneration were revealed. The spores and protoplasts were treated with UV light and N-nitroso-N'-methyl biuret and their effect on production of the antibiotic by the isolated variants was studied. It was shown that the protoplasts of P. chrysogenum were more liable to the mutagenic effect of UV light and nitroso methyl biuret than the fungus conidia. It is possible to use this specific feature in intensification of selection aimed at isolation of highly productive strains of P. chrysogenum.     

Involvement of endogenous digitalis-like factors in voluntary selection of alcohol by rats.

This study tested the hypothesis that endogenous digitalis-like factor (DLF) is involved in the development of alcohol dependence in rats. In 33 male Wistar rats in conditioned place preference (CPP) experiment, ethanol evoked increase in time spent in the ethanol-associated compartment (702+/-82 in ethanol-treated vs. 426+/-86 sec in the controls). Digoxin pretreatment (125 microg/kg, i/p) did not affect the time spent in the water-associated compartment (476+/-80 sec), but prevented the acquisition of ethanol CPP (385+/-112 sec in ethanol-paired side, P<0.05). In a two bottle choice test, where rats (n=6 per group) chose between drinking water and 9% ethanol, immunization against two putative DLFs, marinobufagenin and ouabain (MBG and OLC) resulted in a 60% increase of ethanol consumption. Acute intragastric administration of 9% ethanol to the rats was associated with increased OLC in cerebrospinal fluid, and stimulated urinary excretion of MBG and OLC. Thus, in rats, digoxin, which mimics the effects of DLFs, suppresses the free choice of alcohol, while immunization against DLFs is associated with alcohol seeking behavior.     

A comparative evaluation of methods of radiologic diagnosis in determining the functional status of the right ventricular myocardium in tetralogy of Fallot

In order to study the informative value of two-dimensional echocardiography (EchoCG) in the assessment of right ventricular function in Fallot's tetrad the results of echocardiography were compared with those of angiocardiography. A total of 40 patients aged 2 to 13 with the cyanotic form of the defect were investigated. Functional indices were calculated using Simpson's rule. The highest correlation in comparing echo- and angiocardiography results was obtained for the end-diastolic volume (r = 0.94), a slightly lower one--for the end-systolic volume (r = 0.92). The mean value of the right ventricular ejection fraction (EF) by the results of echocardiography was 0.62 +/- 0.05 +/- 0.08, by the results of angiocardiography--0.62 +/- 0.05 +/- 0.09. The correlation coefficient characterizing the proximity of EF values, obtained by the above methods, was 0.89. The greatest divergences in the results were noted in the calculation of the minute volume. It can be accounted for by the patients' different state at the time of invasive and non-invasive investigation. A high informative value and accuracy of two-dimensional echocardiography was proved in the assessment of right ventricular function in Fallot's tetrad.