Membrane phosphorylation is involved in the inhibitory effect of micromolar Ca2+ on rat myometrial Na+K+-ATPase.
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Animals↗
Biomedical subjects
J Somogyi
Publications and source records attributed to J Somogyi.
Trends and patterns in lung cancer incidence in four cities of Eastern Europe, 1971-1980.
The trends of age-adjusted and age-specific lung cancer incidence rates showed over the period of 1971-1980 substantial differences in four selected towns of Eastern Europe. The downward age-adjusted trends in males coincided in Berlin with the possible beginning of their downturn in the whole country, while their decline in both sexes in Bratislava could be related to the change of demographis factors. In the other two towns studied--Cracow and Tallinn--the substantial increase of lung cancer incidence in males corresponded with the similar evolution in both respective countries (Poland and Estonia). The rising trends in females in both mentioned towns could be more or less compared with their dramatic increase in some developed countries. The rising trends of age-specific rates in younger age groups of males do not indicate meanwhile the positive influence of low-tar or filter-tipped cigarettes on lung cancer incidence in males observed recently in some countries.
Adult↗
Comparison of the maximum capacity for active sodium-potassium transport in the left and right ventricle of mammalian heart.
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Animals↗
The tumor promoter tetradecanoyl-phorbol-acetate (TPA) elicits the redistribution of zinc in subcellular fractions of rabbit thymocytes measured by X-ray fluorescence.
Prolonged (90 minutes) incubation with tumor promoter 12-O-tetradecanoyl-phorbol-13-acetate (TPA) elicits the redistribution of zinc from the nuclear fraction and mitochondria to the cytosol and microsomes in rabbit thymocytes. The zinc redistribution might play a role in the TPA-caused desensitization of T lymphocytes towards calcium and in the TPA-induced inhibition of Gl----S phase transition and cytotoxicity of T lymphocytes.
Animals↗
A quantitative study of morphological reorganization following chronic optic deafferentation in the adult cat dorsal lateral geniculate nucleus.
Neuronal and synaptic reorganization in the lateral geniculate nucleus (dLGN) of adult cats following chronic visual deafferentation has been investigated with the aid of GABA immunocytochemistry and quantitative electron microscopy. The main purpose of this study was to establish the morphological counterpart of the functional plasticity of dLGN relay cells after total visual deafferentation (Eysel: Brain Res. 166:259-271, '79). The results provide evidence that the regained excitability of relay cells is not the result of disinhibition (caused hypothetically by the selective loss of GABAergic cells) since the proportion of GABA-positive and GABA-negative cells as well as the inhibitory synaptic density did not change. The alternative suggestion that the enhanced excitability could be the result of compensatory axonal sprouting by corticothalamic fibers had also to be dropped: the absolute number of corticothalamic axons to the deafferented dLGN remains unchanged. Because of shrinkage of the dendritic trees of dLGN neurons, however, the density of cortical synaptic input at dLGN cells becomes elevated by almost 60%. It is suggested that the regained excitability of relay neurons is the consequence of the combined effects of adaptive (structural) reduction in size ("atrophy") of retinally denervated nerve cells, and, as a consequence, increase of input resistance, reduced shunting effects, and relative increase in density of the excitatory cortical input per neuron.
Animals↗
The possible pitfalls of the measurement of intracellular calcium concentration of lymphocytes with the fluorescent indicator quin2.
The measurement of intracellular calcium concentration of small cells became feasible and relatively easily accomplishable following the development of the fluorescent calcium chelating dye, quin2, by R. Y. Tsien and his co-workers. The present paper gives an experimental survey of the major possible pitfalls of the method such as: 1) the improper choosing of the concentration of quin2/AM, 2) the misinterpretation of the calibration procedure, 3) the accidental heavy metal traces in the medium, and 4) the uneven distribution of quin2 among the individual cells or within a certain cell. We report some original data on: 1) the distorting effect of heavy metal ions on the measurement and the use of chelex 100 resin to eliminate heavy metal traces from the mediums, 2) the negligible contribution of dead cells to the overall fluorescence signal demonstrated by flow-cytometry, and 3) fluorescence polarization of quin2 in lymphocytes.
Aminoquinolines↗
The tumor promoter tetradecanoylphorbol-13-acetate elicits the redistribution of heavy metals in subcellular fractions of rabbit thymocytes as measured by plasma emission spectroscopy.
Prolonged (90 min) incubation with the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) causes no significant changes in the elemental composition of whole rabbit thymocytes (25 elements included). The only exception is the amount of magnesium, where a significant increase can be detected. However TPA preincubation elicits the redistribution of heavy metals (mainly Zn and to a much lesser extent Fe and Cu) from the nuclear and large granular (mitochondrial-lysosomal) fraction to the cytosol and microsomes. A significant translocation of calcium and phosphorus from the large granular fraction mainly to the nucleus can also be observed. The TPA-induced heavy metal depletion of the nucleus might play a role in the antiproliferative activity of TPA, the arrest of G1----S phase transition. On the other hand the increased amount of heavy metals in the cytosol might be linked to the TPA-induced block of intercellular communication and the desensitization of TPA-treated cells towards extracellular calcium which are well-known properties of neoplastic cells.
Animals↗
Morphological alterations in subcortical vibrissal relays following vibrissal follicle destruction at birth in the mouse.
Morphological modifications of two subcortical vibrissal relays were analyzed, following destruction of vibrissal follicles in newborn mice. The volume of the nucleus interpolaris (NI) of the trigeminal nuclear complex in the brainstem decreased by 33%, while the number of its neuronal perikarya decreased only moderately. Vibrissal deafferentation caused no shrinkage of the ventrobasal complex (VB). In the damaged medial vibrissal part of VB (VBm), however, neuronal density was higher than normal, indicating the prevention or retardation of physiologically programmed cell death in the afferentation deprived thalamic somatosensory relay station. It is suggested that the difference in neuron density produced by deafferentation is related to the states of maturation at birth of the two subcortical vibrissal relays. Following vibrissal deafferentation the basic organization of the synaptic neuropil appeared to be similar to the control. Quantitative electron microscopic (EM) analysis revealed, however, an increased number of axon terminals with ovoid synaptic vesicles in both deafferented relay stations. The increased density of gamma-aminobutyric acid (GABA)-immunostained boutons observed in the VBm following vibrissal deprivation suggested a compensatory increase most probably of the inhibitory axon endings. Quantitative EM analysis also provided evidence that many or most of the specific afferent terminals in the damaged VBm were not identical with but were substitutes for the original "vibrissal" specific afferents. Forty percent of all "specific" afferents were shown to be modified corticothalamic terminals. The modification and the resemblence of some cortical endings to specific afferents demonstrated the morphogenetic plasticity of synaptogenesis in these terminals during development as well as the importance and inductive potential of the postsynaptic target in the differentiation of presynaptic axon terminals.
Animals↗
[Current levels and trends in the total incidence and mortality of malignant tumors in Czechoslovakia].
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Czechoslovakia↗
GABA-immunoreactive neurons in the rat cerebellum: a light and electron microscope study.
An antibody raised against gamma - amino-butyric acid (GABA) coupled to bovine serum albumin with glutaraldehyde (Hodgson et al: J. Histochem. Cytochem. 33:229-239, '85) was used to localise immunocytochemically the presumptive GABAergic neuronal elements in the cerebellar cortex of the adult rat. employing the unlabelled antibody enzyme method with pre- and post-embedding immunocytochemical procedures, the following cellular structures were observed to be GABA-immunopositive in both the light and electron microscopes: the somata, dendrites, and axonal processes (including axon terminals) of stellate, basket, and Golgi neurons. In immunopositive neuronal somata and dendrites, the reaction product was found to be associated with all intracellular organelles and with the postsynaptic densities of synaptic junctions. Specific GABA-like immunoreactivity was also seen around outer mitochondrial membranes, microtubules, and neurofilaments, and coating synaptic vesicles in presynaptic axon terminals. In the pre-embedding procedure with dilutions of the antiserum between 1:1,000 and 1:2,000, the perikarya and dendrites of Purkinje cells were GABA-immunonegative, whereas at an antiserum dilution of 1:500 the somata of Purkinje cells were mildly GABA-immunoreactive. Purkinje cell axon terminals in the infra- and supraganglionic plexuses and in the deep cerebellar nuclei were always strongly immunopositive. Neuroglia were invariably GABA-immunonegative, as were the dendrites, axons (parallel fibres), and somata of granule cells. Mossy fibre and climbing fibre afferents were also immunonegative. The pattern of immunoreactivity obtained with this antiserum directed against the inhibitory neurotransmitter GABA was found to resemble closely the immunocytochemical distribution of GABA and of the GABA-synthesizing enzyme glutamic acid decarboxylase (GAD) as reported previously in other immunocytochemical investigations (Oertel et al. and Wu et al: Cytochemical Methods in Neuroanatomy. New York: A. R. Liss, '82; Seguela et al: Neuroscience 16:865-874, '85; Mugnaini and Oertel: GABA and Neuropeptides in the CNS. Handbook of Chemical Neuroanatomy, Vol. 4, Part I. Amsterdam: Elsevier, '85.
4-Aminobutyrate Transaminase↗
Light- and electron-microscopic visualization of gamma-aminobutyric acid and GABA-transaminase in the oviduct of rats. Predominant occurrence in epithelium.
The distribution in the rat oviduct of gamma-aminobutyric acid and its catabolic enzyme GABA-transaminase was studied by the use of immunocytochemical and enzyme-histochemical techniques. At the light-microscopic level, both GABA immunoreactivity and GABA-transaminase enzyme reactivity were found primarily in the tubal epithelium while in the muscle layers of the organ only a faint GABA and GABA-transaminase positive staining could be detected. Electron-microscopic evaluation of the GABA immunoreactivity revealed a heavy labelling of the basal bodies (kinetosomes) and a moderate staining of the cilia. These findings indicate that the role of GABA in the oviduct is not related to neurotransmission but may be related to ciliary functions.
4-Aminobutyrate Transaminase↗
GABA-immunoreactive neurons in the dorsal lateral geniculate nucleus of the rat: characterisation by combined Golgi-impregnation and immunocytochemistry.
Identified neurons in the dorsal lateral geniculate nucleus (dLGN) of the rat were studied using a Golgi/EM procedure in combination with post-embedding GABA immunocytochemistry. The results of this investigation identify clearly the GABA-immunoreactive nature of the two morphologically distinct neuronal populations found within the rat dLGN--thalamocortical relay cells are GABA-immunonegative whilst the putative 'interneurons' are GABA-immunopositive. This immunocytochemical evidence strongly suggests that 'interneurons' synthesize and use GABA to mediate their local inhibitory synaptic mechanisms within the dLGN of the rat.
Animals↗
A quantitative investigation of the neuronal composition of the rat dorsal lateral geniculate nucleus using GABA-immunocytochemistry.
The proportion of neurons immunoreactive for gamma-aminobutyric acid (GABA), and their rostrocaudal distribution in the dorsal lateral geniculate nucleus of the rat, were determined quantitatively using post-embedding GABA-immunochemistry on semithin resin embedded coronal sections followed by stereological analysis. The mean total volume numerical density of neurons (total number of neurons per mm3) in the dLGN was 67,077 +/- 4412 mm-3 (mean +/- SEM; n = 5), comprising a mean volume numerical density for GABA-immunopositive neurons of 14,584 +/- 1324 mm-3, and a mean volume numerical density of GABA-immunonegative neurons of 52,493 +/- 3419 mm-3, GABA-immunopositive neurons constituted 21.7 +/- 0.5% of the total neuronal composition of the rat dorsal lateral geniculate nucleus. Although no rostrocaudal variation was detected in the total volume numerical density of neurons, the relative proportion of GABA-immunopositive neurons was significantly lower in the caudal segment (18.1 +/- 0.6%) compared with the middle (24.9 +/- 0.9%) and the rostral segments (22.1%). Furthermore, on the basis of somatic size distributions, GABA-immunonegative neurons were seen to be significantly smaller in the caudal segment than in the more anterior two segments. The somatic size of GABA-immunopositive neurons showed no rostrocaudal variation through the dorsal lateral geniculate nucleus. These data provide a morphological correlate for the structural and functional subdivision of the dorsal lateral geniculate nucleus described previously in electrophysiological and morphological studies.
Animals↗
Quantification of immunogold labelling reveals enrichment of glutamate in mossy and parallel fibre terminals in cat cerebellum.
The glutamate immunoreactivity of different cell populations was compared quantitatively in the cerebellar cortex of cat, using an antiserum raised against glutamate coupled to bovine serum albumin by glutaraldehyde. Neuronal and glial processes were identified on serial electron microscopic sections which were processed by a postembedding immunogold procedure. The surface density of colloidal gold particles was used for statistical comparison of the relative levels of glutamate in cell populations, or in different parts of the same population. The terminals of mossy and parallel fibres had significantly higher levels of glutamate immunoreactivity than Golgi cell terminals, granule cell dendritic digits, Purkinje cell dendrites or dendritic spines. Golgi cell terminals were identified by their position and GABA immunoreactivity as revealed by immunogold in serial sections. The dendritic digits of the putative glutamatergic granule cells had significantly higher glutamate immunoreactivity than did Purkinje cell dendrites and dendritic spines. Glial cell processes in the molecular layer had lower level of glutamate immunoreactivity than any of the neuronal processes. The results demonstrate that the highest levels of glutamate immunoreactivity occur in mossy and parallel fibre presynaptic terminals that are known to have an excitatory effect. This supports previous suggestions that glutamate may be a transmitter at these synapses. The measurement of the levels of putative amino acid transmitters in identified neuronal populations, or in different parts of the same population, could have wide applications in studies on the chemical neuroanatomy of the nervous system.
Animals↗
[The role of the registry in the fulfillment of the oncology program in Slovakia].
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Czechoslovakia↗
Parity and cancer risk in Slovakia.
Mortality data from women aged 45-74 who died between 1968 and 1977 in Slovakia, Czechoslovakia, were used to examine the effect of parity (number of live-born children) on risk of dying from each of 20 common cancers. After controlling for the effects of age and year of death, the effect of parity on risk was statistically significant at the p less than 0.001 level, for cancers of the stomach, liver, gall-bladder, breast, cervix, and ovary; and at the p less than 0.01 level for uterine corpus and brain. No effect of parity was seen for cancer of the colon or rectum. Among parous women the trend relating risk to level of parity was significant at the p less than 0.001 level for cancers of the breast, uterine corpus, ovary and brain; and at the p less than 0.01 level for stomach cancer. The findings relating parity to cancers of the breast and reproductive organs are consistent with previous reports. The associations of parity with cancers of the digestive tract deserve further study.
Age Factors↗
GABA-immunoreactive neurons in the rat dorsal lateral geniculate nucleus: light microscopical observations.
The dorsal lateral geniculate nucleus (dLGN) of the rat was investigated immunocytochemically using an antiserum against the inhibitory neurotransmitter gamma-aminobutyric acid (GABA). The appearance of GABA-immunopositive dendrites, dendritic appendages, and the size and shape of neuronal somata closely resembled the putative intrinsic neurons described previously in Golgi-impregnation studies of the rat dLGN.
Animals↗
Numerical estimation of gamma-aminobutyric acid (GABA)-containing neurons in three thalamic nuclei of the cat: direct GABA immunocytochemistry.
The percentage of neurons that are immunoreactive for the inhibitory neurotransmitter, gamma-aminobutyric acid (GABA) was determined within: (1) the lateral geniculate nucleus (LGN), (2) the ventrobasal complex (VB) and (3) the antero-ventral nucleus (AV) of the thalamus in the cat. An antiserum to GABA was used to stain GABA-containing perikarya in 1.0 micrometer thick Araldite-embedded sections. Immunostained somata in all three nuclei were invariably smaller than the immuno-negative nerve cells. 27% of all neurons in the LGN, 33% in the VB and 25% in the AV were immunoreactive for GABA.
Animals↗