nuclear envelope, the endoplasmic reticulum and the organelle of camillo golgi classical or diverse pathways for cellular membrane flow

I have suggested a new technique for the transformation of grey scale electron micrographs into colored homologue copies; based on a color - substitution software computer program. In the present study, I have used this technique to study the cellular endomembrane structural connections inside blood monocytes. In addition, the structure of Golgi apparatus was re-interpreted in those cells and in epididymis of adult albino rat. Analysis of thin section photographs revealed diverse locations of biomembrane fusion between the nuclear envelope and the membranes of other organelles; including endoplasmic reticulum cisternae, Golgi apparatus multivesicular bodies, in addition to the cell membrane itself These anatomical relations probably reflected the existence of a junction with remarkably stable ultrastructure. Functionally, this association may orchestrate nucleo-cytoplasmic exchanges and/or add new data that reinforce the view of "membrane flow" hypothesis. This work provides four major new insights. Firstly, membrane flow among members of the cellular endomembrane system probably follows diverse pathways instead of a single route. Secondly, the Golgi apparatus is a dynamic organelle; the change in its position during cell living state may serve the function to antegrade and retrograde transport of molecules as well as membrane constituents to different parts of the cell including the nuclear envelope at different times. Thirdly, whenever present, the "trans-Golgi" network [TGM] at its early stages of formation is continuous with the saccules of the Golgi stack and therefore do not necessarily form a separate compartment. Fourthly the structural features of the TGN suggest that it continuously undergoes renewal, intact TGN cisternae apparently peel-of from the Golgi stacks and persist for some time in the cytosol, and ultimately dissociates from the trans-face of the Golgi stack

Phagocytosis and translocatjon of black carbon particles in the pulmonary alveoli following intra-tracheal instillation to the albino rat lung

Increasing levels of ambient particulate matter resulting from fossil fuel combustion are associated with an increased prevalence of respiratory symptoms. However, it is unknown whether, and to what extent, these pollutant particles penetrate the lower airway. For that reason, the capacity of pulmonary alveolar structures of normal rats to deal with intra-trachealy instilled black carbon was used to assess lung exposure to foreign particles. Intra-trachealy instilled carbon particles reached the distal airway as they were found to be engulfed primarily by wondering macrophages in the alveolar spaces. Incorporation of these particles into the lysosomes of such cells had resulted in their fragmentation into fine and ultrafine particles in addition to particles of the nanometer range size. Probable routes for carbon translocation into the alveolar wall interstifium included; penetration of alveolar wall by non-particulate carbonaceous material; passive transport of particulate carbon through both alveolar epithelium and large sized gaps that might be formed between the alveolar epithelial cells; beside disintegration of carbon-laden macrophages. The translocated carbon excited macrophages and fibroblasts to induce immunological responses and increased collagen deposition respectively. In addition to that, carbonaceous particles of different sizes were found to aggregate inside the cells composing the alveolar epithelium which might impair their normal functions. Our present study expands the understanding of the pathogenesis of carbon particles on lung; such particles were translocated and could cross cellular membranes to exert cumulative toxic effects. These changes might mimic pulmonary inflammation and fibrosis caused by environmental pollution due to incomplete fuel combustion, industrialization and habitual smoking

Protective effect of vitamin E from cisplatin induced hepatotoxicity in albino rats

Cisplatin is a potent drug which is commonly used in treatment of many tumors; however, its high toxicity limits its use. This work was undertaken to study the histo-chemical and ultrastructural changes in the liver of adult albino rats after injection of cisplatin alone and in association with vitamin E. In rats administrated cisplatin alone, the histochemical study showed a significant decrease in both Periodic acid Schiff's reaction and succinic dehydrogenase activity accompanied with an elevation of acid phosphatase reaction in hepatocytes all over the hepatic lobules. In respect to these light microscopic observations, concomitant electron microscopic study revealed deficiency of glycogen aggregates, mitochondrial changes including; decrease in the number, deformity in shape, and loss of some aristae, beside an increase in the number of lysosomes. In addition, nuclear chromatin condensation and widening of the perinuclear cisternae were commonly observed. On the other hand, administration of vitamin E prior to cisplatin led to relief of these histochemical and ultrastructural abnormalities probably owing to the protective anti-oxidant nature of vitamin E. It would be concluded that the use of cisplatin drug alone is highly hepatotoxic, so it is better to prescribe Vitamin-E together with cisplatin to limit its toxic effects