Study of the structure of colonies of active and inactive Actinomyces parvullus variants using luminescence and scanning microscopy]

The colony structure of the active and inactive proactinomycete-like variants of Actinomyces parvullus producing actinomycin D was studied with luminescent and scanning microscopy. Clear differentiation of the colony profile was shown by the structure and functions of the mycelium layers. A zone of active synthesis and accumulation of the antibiotic was observed in the colonies of the active variant in the upper part of the substrate mycelium with reddish-yellow self luminescence in UV light and characteristic close hyphae "cemented" by the intracellular substance. Formations of the granule type were often noted on the hyphae of that layer. The layer of the aerial mycelium was loosely connected with the substrate mycelium and consisted of sporophores and spore chains partially broken into single spores. The colonies of the inactive proactinomycete-like variant had a slightly differentiated profile with a sponge-like structure, no zones of the antibiotic synthesis being found. The presence of the intracellular substance was observed in the upper part of the colony supersubstrate mycelium.     

An analysis of cedar of Lebanon (Cedrus libani A. Rich.) pollen grain development in cultural plantings]

A cytological study of the Cedrus libani mature pollen from 3 culture areas (Italy, France, USSR) has shown that 69-71% of pollen grains have two-celled protallium and antheridial cell. About 5% of pollen grains are characterized by accelerated of delayed development, otherwise apparently normal. The pollen sterility (up to 30% of grains) is due to the abortive spore development. Anomalous cenocyte and multinuclear pollen grains were found thus suggesting that multicellular haploid structures capable of further growth and development may arise in the course of natural anther development.     

An Informational Approach to the Analysis of the Low-Frequency Neuronal Impulse Activity in the Rostral Hypothalamus

Statistical analysis of the low-frequency (1.0 sec^-1 and lower) neuronal impulse activity (IA) meets a few fundamental difficulties. Among them, the most significant is the small number of measurements (interspike intervals) recorded within an acceptable analysis epoch. In our study, we examined the possibility of using the normalized (by its maximum value) informational entropy (Hn) for estimation of the significance of changes in the IA generated by low-frequency neurons of the rostral hypothalamus after electrical stimulation of the prefrontal cortex. We compared the efficiencies of using the U-test (Kolmogorov–Mann–Whitney) and Hn estimate for the analysis of the same samples of neuronal responses. The results allow us to conclude that Hn is a significantly more acceptable estimate for detection of stimulation-induced modifications of the IA generated by low-frequency neurons, as compared with the U-test. The direction of shifts in the Hn value makes it possible to estimate the pattern of neuronal response. This value reflects the state of the neuron and correlates with the type of neuronal responses.     

Effect of an interferon preparation on increasing bacterial sensitivity to antibiotics

Under the effect of human leukocytic alpha-interferon-II for injections there was observed an increase in sensitivity of bacteria to benzylpenicillin, ristomycin, novobiocin, streptomycin, kanamycin, monomycin and erythromycin. A higher antibacterial effect of the penicillin and erythromycin was recorded only with respect to initially resistant strains of staphylococci. For the antibiotic resistant strains of staphylococci the MICs of the penicillin and erythromycin decreased on the average 17.8 and 208 times (p less than 0.001) respectively. The interferon had no effect on sensitivity of bacteria to chloramphenicol.     

Effect of vacuolization on the sodium concentration in an isolated muscle fiber]

Using the Perkin Elmer flame photometer sodium and potassium concentrations have been measured in muscle fibers from the m. ileofibularis of Rana temporaria. After 30 minutes preincubation in the Ringer solution, made hypertonic by the addition of 0.22M glycerol, the muscle fibers were incubated in the normal Ringer solution for 30 min. These fibers showed a vacuolation and an increase in total fiber sodium up to 37.2 mmol/l +/- 5.9 S. E., or 45.8 mmol/kg H2O +/- 7.3 S. E. No significant changes in potassium concentration were observed. Then, the fibers were exposed again to the Ringer solution containing 0.22 M glycerol. This procedure caused the disappearance of vacuoles and decrease in fiber sodium concentration down to 17.7 mmol/l +/- 1.6 S. E., or 21.8 mmol/kg H2O +/- 2.0 S. E. The effect of vacuolation was not blocked by ouabain (1.10(-4) M). It is suggested that the vacuoles have a high NaCl concentration. A model for NaCl and water accumulation in T-tubules is presented.