Microvesicles - potential biomarkers for the interrelations atherosclerosis/type 2 diabetes mellitus.

Microvesicles, also called microparticles or exosomes, are ultrastructural cellular components that have been widely researched in the past as well as present in order to establish their morphology, origin and role in physiological and pathological processes. Advanced techniques show that these microparticles have their clinical implications in the prevention and prediction in pathology and have potential in the discovery of novel therapeutic approaches to metabolic diseases such as diabetes, cardiovascular, autoimmune diseases and cancer.

Electron microscopic study of the arterial wall in the cerebral aneurysms.

The ultrastructural modifications were observed in electron microscopy of the congenital aneurysm of the internal carotid artery with subarachnoid hemorrhage. The tunica intima very enlarged contains in the endothelial cells numerous microvesicles of pinocytosis, and rare cell organelles. The internal elastic lamina presented ruptured or absence zones.

Ultrastructural features of blood cells in atherosclerosis.

Atherosclerosis is a complex process that affects specific tissues of the vasculature, susceptible to developing atherosclerosis. >From 10 patients with atherosclerosis, between 50-70 years, peripheral blood was prelevated and after the technical procedures the blood cells were studied using the electron microscopy. The most characteristic morphological modifications were observed in agranulocytes and platelets.

Atrial natriuretic factor in the ischemic heart.

The synthesis and the release of the atrial natriuretic factor (ANF) were studied by electron microscopy in the atrial cells from an ischemic myocardium. The ANF-containing secretory vesicles of normal atrial cells were present in great number near the Golgi apparatus, and near the sarcolemma. After 30 min.

Histochemical demonstration of folic acid metabolism, some lysosomal activities and NADH2-cytochrome-C-reductase in corpora mammillaria in the ageing process.

In bovine corpora mammillaria of young animals, a folic acid positive reaction was found in the neurons and in the neuroglia, in parallel with high dihydrofolate-reductase activity in the nerve cells. In old animals, folate and lysosome enzymes were different in the lateral and in medial nucleus, the highest amount being observed in the lateral nucleus; in the glial cells the lysosomal enzymes increased and in the nerve cells the concentration of folic acid increased. In the medial nucleus only relatively few enzyme modifications in the process of senescence were noticed.

Ultrastructural localization of Ca2+ in the Golgi apparatus of two different cell types.

The precipitation reaction with potassium oxalate was used to investigate the subcellular localization of Ca2+ in atrial myocardocytes and in Schwann cells of non-myelinated nerve fibers. Chelation with EGTA was used to prove the presence of Ca2+ in the electronoopaque deposits. In both cell types the oxalate reaction was intense in the classically described Ca2+ deposits: the perinuclear cisterna, the endo (sarco) plasmic reticulum, the mitochondrial matrix, but also in a novel localization: the cisternae of the Golgi stack in all cis to trans positions, suggesting that Golgi Apparatus is a major intracellular Ca2+ pool.

Cholinergic innervation of the ventricular myocardium in the human fetal heart.

Specimens of human fetal hearts from the 9th to the 27th week of intrauterine life were processed by the technique of Karnowski and Roots as modified by Lewis for the demonstration of acetylcholinesterase-positive nerve fibers by light microscopy. Cholinergic innervation was present in both atria and ventricles even in the 9th week of intrauterine life. In the ventricles the number of cholinergic fibers augmented with increasing age; they spread in the ventricular wall surrounding the vascular network including capillaries, or following their course in the close proximity of cardiac muscle fibers.

Histochemical localization of folic acid in the motor end plate.

Folic acid investigated in motor end plate by histochemical method appeared in the long nerve terminals of the motor axon, in the cytoplasm of Schwann cell. In muscle fibre opposite to the nerve arborizations, spaced granular lines perpendicular to the sarcolemma were observed.

Calcium cytochemistry and stereological morphometry of the intercalated ductal cells of the pancreas.

Using K-antimonate procedure, Ca2 binding sites in pancreatic small ductal cells were studied. Great precipitates were observed in the lumen of intercalated ducts, on luminal, contraluminal and lateral plasmalemma of centroacinar cells and in some of their organelles especially in mitochondrial matrix as well as on the euchromatin. Fine precipitates were present mainly on the endomembranes of perinuclear cisternae, endoplasmic reticulum, Golgi vesicles, mitochondria, secretory vesicles.

Histochemical and ultrastructural data in the spleen of the copper-intoxicated rat.

By histochemical methods and electron microscopy, the spleen of copper-loaded rat was investigated. Oxidoreducing enzymes (diaphorase, succinate dehydrogenase, lactate dehydrogenase, prolineoxidase, hydroxyproline epimerase) and phosphatases (acid, ATP-ases) were tested. In general, in the intoxicated rat, the oxidases and dehydrogenases were depressed in the splenic cells, except macrophages and endothelial cells.

Estimation of the copper-iron correlation in the liver under experimental conditions. A microscopic and microchemical study.

Liver obtained from copper-intoxicated rats was studied by electron microscopy and electron probe microanalysis. Large ultrastructural disorders in liver cells appeared at the level of lysosomes and mitochondria. Diffuse and aggregate copper granules were observed in the entire cell, but mainly in pericentrolobular and periportal zones.

Folate metabolism in ageing.

Important histochemical observations on the nervous system, obtained in the last years, showed characteristic changes in folic acid and in its main enzyme--dihydrofolate reductase--in the old nerve cells. In neurons, the enzymic activity gradually decreased and folic acid accumulated in ageing. Glial cells preserved or slightly increased the same folate enzyme, but folic acid markedly increased in senescence.

Histochemical localization of folic acid in the cells.

Smears, fresh cryotome sections (dried at 4 degrees C for 24 h), and deparaffinized sections were used for the "in situ" localization of folic acid. After irradiation with ultraviolet light, folic acid breaks down into a pteridine and a diazotizable amine. After oxidation and a brief hydrolysis, glyoxylic acid formed from the pteridine can be vizualized by a coupling agent, indicating the sites of folic acid in the cell.

The kinetics of the histochemical method for dihydrofolate dehydrogenase (dihydrofolate reductase).

The purpose of the present investigation is to report some histochemical and cytospectrophotometric observations providng more objective evidence for the specific activity of the histochemical method for dihydrofolate reductase activity (5.6.7.

Folate metabolism in the superior cervical ganglion histochemical study.

By means of histochemical methods, folic acid, dihydrofolate reductase and NADH2-cytochrome-C-reductase were studied in the bovine superior cervical ganglion, in parallel with quantitative estimations of dihydrofolate reductase activity and in connection with the process of ageing. Various levels of folate metabolism were present in nerve cells and glial cells, as well as in pre or postganglionic nerves. In the process of ageing the activity of dihydrofolate reductase gradually decreased and the folic acid concentration in the nerve cells increased.

Histochemical study of leucine aminopeptidase in leukemia.

By means of a histochemical method, the leucine aminopeptidase activity was studied in human normal and leukemic peripheral blood. Before administration of cytostatics the enzymic activity was high in the cytoplasm of blasts and in the nuclei of segmented cells. After therapy the activity of leucine aminopeptidase in blasts decreased, while in polymorphs it became negative in nuclei and positive in their cytoplasm.

"In situ" variation of folic acid and dihydrofolate reductase in the caudate nucleus in the ageing process.

In bovine caudate nucleus of young animal, a folic acid-positive reaction was found in the perikarya and in the neuroglia in parallel with a high dihydrofolate reductase activity in the nerve cells. In old animals, folic acid increased in neurons, neuroglia and some nerve cell processes; the folate enzyme was markedly decreased in neurons and increased neuroglia NADH2-cytochrom-C-reductase activity was strongly positive in nerve cells in young and old animals.

Histochemical study on the dihydrofolatereductase and folic acid in mammalian brain cortex.

Histochemical and biochemical studies on the folate metabolism (folic acid an its principal enzyme-dihydrofolate-reductase) in bovine cortex - gyrus marginallis in the process of ageing were performed, in parallel with NADH2-cytocrom-C-reductase (diaphorase). Folic acid and folate enzyme, weak positive in neurons in young age, increased in old age in nerve cells and especially in their processes and in capillaries. The diaphorase strongly increased in all cells, glia and vessels, in old age.

Cytochemical demonstration of folic acid in normal and leukemic granulocytes.

By means of an original cytochemical method, folic acid was demonstrated "in situ" in peripheral white blood cells in acute and chronic granulocytic leukemia. In control blood smears folic acid-relevant granules were found predominantly in the nuclei of neutrophils and basophils. Eosinophils were found positive for folic acid reaction both in nuclei and cytoplasm.