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1.
Elemental distribution in striated muscle and the effects of hypertonicity: Electron probe analysis of cryo sections 总被引:15,自引:4,他引:11 下载免费PDF全文
A method of rapid freezing in supercooled Freon 22 (monochlorodifluoromethane) followed by cryoultramicrotomy is described and shown to yield ultrathin sections in which both the cellular ultrastructure and the distribution of diffusible ions across the cell membrane are preserved and intracellular compartmentalization of diffusabler ions can be quantitated. Quantitative electron probe analysis (Shuman, H., A.V. Somlyo, and A.P. Somlyo. 1976. Ultramicros. 1:317-339.) of freeze-dried ultrathin cryto sections was found to provide a valid measure of the composition of cells and cellular organelles and was used to determine the ionic composition of the in situ terminal cisternae of the sarcoplasmic reticulum (SR), the distribution of CI in skeletal muscle, and the effects of hypertonic solutions on the subcellular composition if striated muscle. There was no evidence of sequestered CI in the terminal cisternae of resting muscles, although calcium (66mmol/kg dry wt +/- 4.6 SE) was detected. The values of [C1](i) determined with small (50-100 nm) diameter probes over cytoplasm excluding organelles over nuclei or terminal cisternae were not significantly different. Mitochondria partially excluded C1, with a cytoplasmic/ mitochondrial Ci ratio of 2.4 +/- 0.88 SD. The elemental concentrations (mmol/kg dry wt +/- SD) of muscle fibers measured with 0.5-9-μm diameter electron probes in normal frog striated muscle were: P, 302 +/- 4.3; S, 189 +/- 2.9;C1, 24 +/- 1.1;K, 404 +/- 4.3, and Mg, 39 +/- 2.1. It is concluded that: (a) in normal muscle the "excess CI" measured with previous bulk chemical analyses and flux studies is not compartmentalized in the SR or in other cellular organelles, and (b) the cytoplasmic C1 in low [K](0) solutions exceeds that predicted by a passive electrochemical distribution. Hypertonic 2.2 X NaCl, 2.5 X sucrose, or 2.2 X Na isethionate produced: (a) swollen vacuoles, frequently paired, adjacent to the Z lines and containing significantly higher than cytoplasmic concentrations of Na and Cl or S (isethionate), but no detectable Ca, and (b) granules of Ca, Mg, and P = approximately (6 Ca + 1 Mg)/6P in the longitudinal SR. It is concluded that hypertonicity produces compartmentalized domains of extracellular solutes within the muscle fibers and translocates Ca into the longitudinal tubules. 相似文献
2.
The article deals with recent research in the field of fundamental knowledge about the mechanisms of information processing in the human brain for the diagnosis of mental disorders performed in the laboratory of neurobiology for action programming of the Bechtereva Institute of the Human Brain of the Russian Academy of Sciences. These studies were connected with the analysis of functional components for cognitive event-related potentials (ERPs) obtained under various behavioral conditions. The main goal of this fundamental approach is the decomposition of multi-channel ERPs into functionally different components. These components are generated in various cortical areas, have different temporal dynamics, and reflect a variety of mental operations. The main methodology we used is the independent component analysis, applied to a large set of ERPs (from hundreds of people) obtained by varying functional conditions in the psychological test. In particular, components related to psychological processes, such as the comparison of sensory signals with a trace in working memory, inhibition of current activity, and monitoring of conflict, were identified in the GO/NOGO test. In the European project, a normative database was constructed for the components described above, and this allowed us to compare the data obtained from large groups of patients (including patients with attention deficit disorder, schizophrenia, obsessive disorders, depression, autism, dyslexia, brain trauma, and dementia) with the healthy subjects. This article presents data from patients with a diagnosis of attention deficit disorder and schizophrenia. 相似文献
3.
AV Shevchenko IG Budzanivska TP Shevchenko VP Polischuk D Spaar 《Archives Of Phytopathology And Plant Protection》2013,46(2):139-146
The work was focused on the investigation of possible dependencies between the development of viral infection in plants and the presence of high heavy metal concentrations in soil. Field experiments have been conducted in order to study the development of systemic tobacco mosaic virus (TMV) infection in Lycopersicon esculentum L. cv. Miliana plants under effect of separate salts of heavy metals Cu, Zn and Pb deposited in soil. As it is shown, simultaneous effect of viral infection and heavy metals in tenfold maximum permissible concentration leads to decrease of total chlorophyll content in experiment plants mainly due to the degradation of chlorophyll a. The reduction of chlorophyll concentration under the combined influence of both stress factors was more serious comparing to the separate effect of every single factor. Plants' treatment with toxic concentrations of lead and zinc leaded to slight delay in the development of systemic TMV infection together with more than twofold increase of virus content in plants that may be an evidence of synergism between these heavy metal's and virus' effects. Contrary, copper although decreased total chlorophyll content but showed protective properties and significantly reduced amount of virus in plants. 相似文献
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I. S. Nikishena V. A. Ponomarev V. A. Grin'-Yatsenko Yu. D. Kropotov 《Human physiology》2004,30(4):392-396
Changes in EEG spectrum power from 19 electrode sites were studied in 19 children with attention disorders during one session of EEG–biofeedback (EEG–BFB). EEG–BFB was aimed at increasing the relative power of the 1 rhythm (15–18 Hz) in sites Fz–C
3 with a bipolar electrode assembly. Comparison of the EEG spectrum powers at relaxation versus training periods in one BFB session revealed significant changes in the left parasagittal frontoparietal area (F
3, Fz, C
3, C
4, P
3). 相似文献
6.
The BCL-xL and ACR-1 genes promote differentiation and reduce apoptosis in muscle fibers of mdx mice
Mikhaĭlov VM Kropotov AV Zelenin AV Krutilina RI Kolesnikov VA Zelenina IA Baranov AN Shteĭn GI Ostapenko OV Tomilin NV Baranov VS 《Genetika》2002,38(11):1445-1450
The effects of the human BCL-xL and ACR-1 genes on dystrophin expression in cross-striated muscle fibers (CSMF) and on CSMF viability were studied in mdx mice after ballistic cotransfection with the human dystrophin minigene. In control mice, the proportion of dystrophin-positive (D(+)) and dying CSMF were 2.1 +/- 0.1 and 2.1 +/- 0.3%, respectively. Introduction of the dystrophin minigene (20 micrograms of the pSG5dys plasmid) increased the proportions of D(+) and dying CSMF to 5.6 +/- 1.4% and 4.5 +/- 0.9%, respectively. When pSG5dys was introduced along with the pSFFV-Neo plasmid carrying the BCL-xL gene (10 micrograms of each plasmid per shot), the death of CSMF decreased to 3.7 +/- 1% and the proportion of D(+) CSMF significantly (P < 0.05) increased to 12.2 +/- 2.2%. Contransfection with the dystrophin minigene and the BCL-xL gene at 20 micrograms of each plasmid per shot did not stimulate generation of D(+) CSMF, but did reduce the CSMF death to 1.5 +/- 0.3%. Introduction of pSG5dys along with the pRc-CMV-10.1 plasmid containing the ACR-1 gene (10 micrograms of each plasmid per shot) reduced the proportion of D(+) CSMF to 1.1 +/- 0.5% and significantly reduced the proportion of dying CSMF to 0.9 +/- 0.3% as compared with the proportions observed in intact mice or in mice subjected to transfection with pSG5dys. Introduction of the pSG5dys plasmid substantially reduced the proportion of CSMF with peripheral nuclei, suggesting disturbed CSMF differentiation. After cotransfection with the human-dystrophin minigene, the BCL-xL and ACR-1 genes did not affect the extent of CSMF differentiation as compared with that observed in the case of the dystrophin minigene alone. Thus, ballistic transfection of mdx mice with the human dystrophin gene used along with the BCL-xL or ACR-1 gene was shown to suppress the death of muscle fibers and to expedite dystrophin synthesis and cell differentiation. 相似文献
7.
V. A. Grin'-Yatsenko Yu. D. Kropotov V. A. Ponomarev L. S. Chutko E. A. Yakovenko 《Human physiology》2001,27(3):259-266
The effects of the EEG–biofeedback (EEG–BFB) procedure, aimed at increasing the sensorimotor (12–15 Hz) and (15–18 Hz) rhythms on the psychological and electrophysiological parameters of attention, were studied using the methods of scalp recording of evoked potentials in the bistimulus paradigm Go/No–Go and a psychological attention test (Test of Variables of Attention; TOVA). Twenty-five children with attention disorders were included in the study. EEG–BFB sessions significantly improved the attention, behavior, and school study results in 19 (76%) children. In these cases, a significant increase in the amplitude of the inhibitory component in the frontocentral leads and improvement of the TOVA parameters were found. 相似文献
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