Focal degradation of cytoplasmic organelles in cardiomyocytes during regenerative and plastic myocardial insufficiency

2000 ◽  
Vol 130 (6) ◽  
pp. 1190-1195 ◽  
Author(s):  
L. M. Nepomnyashchikh ◽  
E. L. Lushnikova ◽  
D. E. Semenov
Keyword(s):  
Cytoplasmic Organelles ◽  
Myocardial Insufficiency ◽  
Plastic Myocardial Insufficiency

Ultrastructure and Stereology of Cardiomyocytes in the Development of Regenerative and Plastic Myocardial Insufficiency during Ontogeny

2011 ◽  
Vol 151 (1) ◽  
pp. 88-94 ◽  
Author(s):  
L. M. Nepomnyashchikh ◽  
E. L. Lushnikova ◽  
N. A. Molodykh ◽  
M. G. Klinnikova ◽  
O. P. Molodykh
Keyword(s):  
Myocardial Insufficiency ◽  
Plastic Myocardial Insufficiency

The ?disappearing cardiomyocytes? phenomenon in plastic myocardial insufficiency

1984 ◽  
Vol 97 (5) ◽  
pp. 689-694 ◽  
Author(s):  
D. E. Semenov ◽  
L. A. Semenova ◽  
L. M. Nepomnyashchikh ◽  
Yu. G. Tsellarius
Keyword(s):  
Myocardial Insufficiency ◽  
Plastic Myocardial Insufficiency

Spermatogenesis in the Dragonfly with Particular Reference to the Cytoplasmic Organelles

1972 ◽  
Vol 30 ◽  
pp. 110-111
Author(s):  
Sant S. Sekhon
Keyword(s):  
Endoplasmic Reticulum ◽  
Golgi Apparatus ◽  
Mature Sperm ◽  
Electron Microscopic ◽  
Cytoplasmic Organelles ◽  
Microscopic Studies ◽  
Insect Sperm ◽  
Large Round

Although there have been numerous studies concerning the morphogenetic changes accompanying the maturation of insect sperm, only a few deal with the sperm differentiation in the dragonflies. In two recent electron microscopic studies Kessel, has comprehensively treated the erlationship of microtubules to the nucleus and mid-piece structures during spermiogenesis in the dragonfly. The purpose of this study is to follow the sequential nuclear and cytoplasmic changes which accompany the differentiation of spermatogonium into a mature sperm during spermatogenesis in the dragonfly (Aeschna sp.).The dragonfly spermatogonia are characterized by large round nuclei. Loosely organized chromatin is usually unevenly distributed within the spermatogonial nuclei. The scant cytoplasm surrounding the nucleus contains mitochondria, the Golgi apparatus, elements of endoplasmic reticulum and numerous ribosomes (Fig. 1).

Cardiotoxicity with antihypertensive drugs (literature review) Part 1. Calcium channel blockers and beta-blockers

2021 ◽  
pp. 12-19
Author(s):  
A. N. Esaulenko ◽  
A. Yu. Moiseeva ◽  
A. A. Ivannikov ◽  
I. V. Bratischev ◽  
Kh. G. Alidzhanova
Keyword(s):  
Calcium Channel ◽  
Calcium Channel Blockers ◽  
Antihypertensive Drugs ◽  
Beta Blockers ◽  
Research Literature ◽  
Channel Blockers ◽  
Distinctive Features ◽  
Experimental Pharmacology ◽  
Myocardial Insufficiency ◽  
Β Blockers

The effect of hypotensive drugs overdose on cardiovascular system is poorly studied; it should undergo clinical, experimental pharmacology and toxicology together with cardiology. There is too little information about cardiotoxicity of beta-blockers (β-blockers) and calcium channel blockers (CCB) in existing research literature. Intoxication from these groups of drugs causes similar severe hemodynamic abnormalities and myocardial insufficiency, however pathophysiological mechanisms of these abnormalities are not thoroughly studied. The review highlights how difficult it is to identify toxic level and distinctive features of clinical evidence of intoxication. Methods of diagnosis as well as β-blockers and CCB overdose treatment are discussed.

The ultrastructure of oogonia and oocytes in the foetal and neonatal rat

1962 ◽  
Vol 157 (966) ◽  
pp. 99-114 ◽  
Keyword(s):  
Meiotic Prophase ◽  
Developmental Stages ◽  
Post Partum ◽  
Chromatin Condensation ◽  
Complex Form ◽  
Neonatal Rat ◽  
Mitotic Chromosomes ◽  
Thin Sections ◽  
Cytoplasmic Organelles ◽  
Spindle Fibres

Ovaries from eighty foetal and neonatal rats (aged 16·0 days post coitum to 4 days post partum ) were examined under the electron microscope. All the normal developmental stages (oogonia and oocytes in the leptotene, zygotene, pachytene, diplotene and dictyate phases of meiotic prophase) were identified. Patterns of degeneration (‘atretic divisions’, ‘ Z ’ cells and atresia at the diplotene phase), whose histological appearance and incidence have been recorded by Beaumont & Mandl (1962), were also recognized. The nuclei of oocytes at the leptotene phase contain single electron dense threads which become aligned in parallel pairs at the following phase (zygotene). A third finer fibril half-way between them appears at pachytene (tripartite ribbon). The longitudinal segments of threads, visible in ultra-thin sections, become shorter, presumably due to coiling. Nuclei at the diplotene phase contain single threads essentially similar to those seen at leptotene. As the oocyte enters the dictyate or resting phase, electron dense threads disappear from the nucleus. These observations suggest that the threads represent chromosomal ‘cores’. Nucleolus-like components persist throughout meiotic prophase, and at the diplotene phase regain the more complex form typical of oogonia. The cytoplasmic organelles become more numerous and complex as the oocyte approaches the dictyate phase. ‘Atretic divisions’ in oogonia are characterized by the persistence of long segments of nuclear membrane and the appearance of vesicles enveloped by a double membrane resembling the nuclear envelope. The dense masses of ‘chromatin’ (mitotic chromosomes) are more rounded than in normal cells at metaphase, and tend to coalesce. Spindle fibres have not been observed. Cytoplasmic organelles tend to increase in number and complexity. ‘ Z ’ cells (cells degenerating largely at the pachytene phase) show heavy ‘chromatin’ condensation around the tripartite ribbons. The major cytoplasmic changes consist in swelling of the endoplasmic reticulum, vacuolation of mitochondria and increase in incidence of multilamellar bodies. Atretic oocytes at the diplotene phase differ markedly from ‘ Z ’ cells in that ‘chromatin’ condensation around electron dense threads (single) is markedly less prominent. Cytoplasmic changes are similar to those of ‘ Z ’ cells, but also include a rise in the incidence of multivesicular and other complex bodies. All three types of degenerating cells are removed from the ovary by the phagocytic activity of neighbouring somatic cells.

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