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Biomedical subjects

L Z Pevzner

Publications and source records attributed to L Z Pevzner.

At least 19 recordsLinked to original sources
PubMed1987

The white blood cell differential. Evaluation of rapid impression scanning versus the routine manual count.

A quick, one and a half-minute qualitative microscopic scan was investigated as an alternative approach to the more labor-intensive 100-cell differential white blood cell count. The scanning results of 400 randomly selected hospital cases were compared with the on-line results of the 100-cell counts. Additionally, 50 cases selected to have a high percentage of abnormal results were each scanned and manually counted by four different readers. The results indicate that the scanning differential is equivalent to the 100-cell manual count in the detection of the presence of abnormal cell types such as immature granulocytes and blasts. Its ability to properly estimate the relative proportions of normal cells, especially lymphocytes, however, does not appear as reliable as the manual count. Most importantly, the analysis demonstrates that the scanning differential count exhibits a set of advantages and disadvantages that is complementary to those of the "three-part differential" technic provided by the newer generation automated hematologic analyzers. The authors therefore propose that these two procedures used in combination offer a suitable alternative to the manual 100-cell differential count.

Basophils↗
PubMed1979

Autoradiographic comparison of neuronal and glial protein metabolism in rat hippocampus after food-motivated or footshock-motivated conditioning.

Quantitative autoradiography has shown that initial food-motivated conditioning results in an increase in 3H-phenylalanine incorporation into cytoplasmic proteins of rat hippocampal neurons. After 3 daily conditioning trials, the incorporation returned to an active control (pseudoconditioning) level while after 6 daily trials, the incorporation was decreased. No changes were revealed in the cells of hippocampal perineuronal glia. Four hours after a footshock-motivated passive avoidance trial, incorporation of 3H-phenylalanine was increased both in the neurons and in their perineuronal glia of rat hippocampus. By the time of a consolidation of this conditioning, such increase still remained perineuronal glia. An importance of the emotional background is outlined for a participation of glial cells in learning-induced metabolic changes in the nervous system.

Animals↗
PubMed1979

Procedure of RNA extraction which does not extract DNA and proteins from nervous tissue cells.

Several schemes of acidic extraction of RNA taken from biochemical or cytochemical literature were compared by means of ultraviolet and visible cytospectrophotometry. Basing on the data obtained an extraction scheme has been recommended which consists in the treatment of nervous tissue sections with 16 per cent perchloric acid at 4 degrees C for 48 h. This extraction has been shown to extract completely cellular RNA without extracting DNA and proteins from the nervous tissue cells. Using this scheme, ultraviolet cytospectrophotometry of neurons and glial cells was performed twice, before and after the selective RNA extraction, which enabled a calculation of RNA concentration by the difference of the absorption values. In mice, after 3 h-swimming, and in cats, after 2-week daily injections of adrenaline, a number of quantitative and qualitative RNA changes were found out in nerve and glial cell of mouse spinal cord and cat sympathetic ganglion with the aid of the recommended scheme of RNA extraction.

Animals↗
PubMed1979

Cytospectrophotometric evaluation of Amido Black staining of proteins in nervous tissue cells.

Cytospectrophotometry of agar films soaked with serum albumin and of nervous tissue cells has shown that the histochemical colour reaction of proteins with Amido Black 10 B obeys Beer's law and that the spectral characteristics of this reaction are not significantly changed after fixation and histological procedure of nervous tissue. In cats, after in situ electrostimulation, and in rats, after anticipation stress, quantitative changes in the total protein content per cell were revealed in nerve and glial cells of cat sympathetic ganglion and rat spinal cord with the aid of cytospectrophotometry of Amido Black-stained sections. Staining with Amido Black 10B is recommended for cytospectrophotometric determinations of total protein and of separate protein fractions in nervous system cells.

Amido Black↗
PubMed1978

Does visual deprivation in adult animals affect macromolecular metabolism in visual neurons?

Two-wave-length visible cytospectrophotometry of gallocyanin-stained sections has shown that 30-day-long visual deprivation in adult rats results in an augmentation of RNA content per cell in the neurons of all cell layers in visual cortex. Light stimulation which in normally reared rats brought about an accumulation of RNA in visual cortex neurons gave rise in light-deprived animals to a disappearance of the deprivation-induced increase of neuronal RNA content. In retina ganglion neurons, RNA content per cell was not changed after the visual deprivation as well as after the illumination of the deprived rats although in normal animals this stimulation evoked an increase of RNA content in the retina neurons. The conclusion is made about marked alterations in macromolecular metabolism induced by a long-term hypoactivity in central and peripheral visual neurons of adult animals.

Animals↗
PubMed1978

Constant and flickering light stimulations produce similar effects on RNA content in visual cells.

Adult male rats were illuminated for 2 h with a constant or flickering light of 40 Lx intensity; frequency of flickering was 2 Hz. By means of two-wave-length visible cytospectrophotometry of gallocyanin-stained sections, it was shown that the light stimulation resulted in a marked RNA accumulation in retina ganglion neurons and in the neurons of all the cell layers of visual cortex (with the only exception of the layer VI). In the cells of perineuronal glia, a decrease of the RNA content per cell was found in the retina while no changes were observed in the visual cortex. Effects of constant and flickering light stimulations were qualitatively and quantitatively similar.

Animals↗
PubMed1978

Circadian oscillations of nucleic acid and protein content in functionally different neuron-neuroglia units of rat central nervous system.

Scanning integrating visible cytospectrophotometry of gallocyanin-, amido black-, fast green- or ammoniacal silver-stained sections of various areas of the central nervous system of adult rats sacrificed at 4 h intervals has demonstrated the presence of circadian changes in RNA, total protein and total histone content as well as in arginine-rich to lysine-rich histone ratio in the neurons and in their perineuronal satellite neuroglia. The peak of the content per cell of the macromolecular components studied was in some cases elevated above their lowest level up to 1.7-fold. The zenith in the content of neuronal RNA coincided as a rule with the nadir in the content of glial RNA whereas no such opposition was observed with respect to the protein or histone content as well as to the arginine- to lysine-rich ratio in the neurons and in their glial satellite cells. The data obtained have confirmed earlier observations that under changed conditions of neuron functioning, the changes in the nervous system metabolism occur which are localized not only in the neurons but also in the neuroglia, the metabolic response in the glial cells being characterized, depending on peculiarities of the particular neuron activity, both by similarity and by some differences as compared with the neuronal metabolic response. A synchronizing effect of environmental and/or internal factors on the macromolecular metabolism within various cell populations of the central nervous system is discussed.

Animals↗
PubMed1978

[Protein concentration in the neuron--neuroglia system of the anterior horns of the spinal cord in rats following exposure to the tranquilizer diazepam against a background of anticipation stress].

Anticipation stress was induced in 16 day-old male rats by placing the animals daily for 7 days into individual cells for 45 min. In the end of each 45 min session, an electric stimulation of paws of the animals was done for 2 min. It was shown by visible cytospectrophotometry of amido black-stained spinal cord sections that the anticipation stress for 7 days resulted in an accumulation of the nuclear and cytoplasmic total proteins in the motoneurons of spinal cord anterior horns, with no changes in the body (in fact, in the nuclei) of the glial cells adjacent to the neurons. Intraperitoneal injection of the tranquilizer diazepam (10 mg per kg) 40 min. before the beginning of the last anticipation stress session gave rise to the return to the normal of the protein content per cell in the motoneuron nucleus and cytoplasm while inducing an increase in the quantity of neuroglia cell protein. Differences in the protein metabolism between the neurons and the neuroglia are discussed.

Animals↗
PubMed1978

[Concentration of acid proteins in the nuclei of rat hypothalamic neuron and glial cell nuclei during cold adaptation].

By means of two-wave length cytospectrophotometry the acid protein content per cell was determined in the nuclei of the neurons and their glial satellite cells of the medial peroptic area and the supraoptic nucleus of the hypothalamus of rats kept at 2--4 degrees C for 1, 3, 7, or 15 days (adaptation to cold). This colling resulted in an initial decrease in the nuclear acid protein content in the whole neuron-neuroglia system of the medail preoptic area with a gradual restoration to the normal by the 15th day of constant cooling. In the glial cells of this area the acid protein content increased temporarily above the control level before the restoration to the normal. A gradual accumulation of acid proteins and its following restoration to the control level was revealed in the neuron-neuroglia system of the supraoptic nucleus. By the 15th day of the adaptation to cold the content of neuronal and glial acid proteins of this nucleus became somewhat lower than in the control.

Acclimatization↗
PubMed1978

[Elaboration of a conditioned alimentary reflex and protein turnover in hippocampal neurons and neuroglia].

A single session of the food conditioning in rats entailed an increase of labelled phenylalanine incorporation into the proteins of the nuclei and, particularly, of the cytoplasm of CA3 hippocampal neurons. In the trained animals, as compared with active control group, a session repeated in 3 days returned the turnover of neuronal proteins to the control level, while the same session in 6 days of decreased the protein turnover below the control level. No changes occurred in the course of the experiment in the perineuronal neuroglial cells. Predominant involvement of neuronal protein metabolism is outlined in the metabolic reconstruction within the whole neuron-neuroglia unit in the course of conditioning.

Animals↗
PubMed1978

Analysis of some histochemical colour reactions for cytospectrophotometry of basic and acidic proteins in nervous tissue cells.

Cytospectrophotometric analysis of model systems and of single cells in Carnoy-fixed paraffin sections of the nervous tissue has shown two histochemical colour reactions for basic proteins and two reactions for acidic proteins to obey Bouger-Lambert-Beer's law. Basic proteins can be stoichiometrically stained either with Fast Green FCF, pH 8.2, or with heparin-Alcian Blue; acidic proteins either with Fast Green, FCF, pH 2.6, or with Toluidine Blue o. basing on better reproducibility of cytochemical results and sufficiently good preservation of cell structure, heparine-Alcian Blue is recommended for cytospectrophotometric determinations of basic proteins. To stain acidic proteins both Fast Green, pH 2.6, and Toluidine Blue O are recommended, each of the dyes being characterized by its own advantages and disadvantages.

Animals↗
PubMed1978

Quantitative microspectral evaluation of the ratio of arginine-rich to lysine-rich histones in neurons and neuroglial cells.

Staining of nervous tissue sections with ammoniacal silver according to Black et al. has been confirmed to be a reliable histochemical colour reaction for quantitative evaluation of arginine-rich and lysine-rich histones in cell structures on the basis of determinations of the position of spectral curve maximum. Neurons of several brain nuclei which differed in predominating neurotransmitter did not differ in the ratio of arginine-rich to lysine-rich histones while some differences in this ratio were found out in the glial satelite cells adjacent to the corresponding neurons of these nuclei. Moderate circadian fluctuations were observed in the arginine-rich to lysine-rich histone ratio, these fluctuations being rather similar in the neurons studied and in the cells of perineuronal neuroglia.

Animals↗