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A R Chirculescu

Publications and source records attributed to A R Chirculescu.

17 recordsLinked to original sources
PubMed1982

Elements of structure and ultrastructure of the blood-thymus barrier in ACTH involuted thymus.

The ACTH influence upon the thymus may be a reliable model for stress involution. In this case, the cortical lymphocytic depletion is accompanied by mast cell accumulation and increased caliber of the blood vessels. The blood-thymus barrier which has an active role in involution shows an enriched transport activity of the endothelial cells, great enlargement of the basement membrane, increased macrophage activity within the perivascular space with elevated values of acid phosphatase activity, and thickening of the fibrillar network. The epithelioreticular cells show plenty of vacuoles in their cytoplasm, the mitochondria undergo swelling processes, and their cristae are diminished. The ultrastructural data show that lymphocyte depletion is carried out by macrophage-mediated lymphocytolysis. But by counting the peripheral blood cells an earlier mechanism is revealed; i.e. migration through the enlarged but more permeable blood-thymus barrier. The epithelioreticular cells do not seem to have an active, direct implication in any of the phenomena.

Adrenocorticotropic Hormone↗
PubMed1975

Dynamic aspects of the liver ATP-ase and its functional involvement in propranolol treated rat.

High doses of propranolol give rise to a liver disenzymic injury by depression of its clearance and colloidopexic functions, but without any histological change. The molecular target responsible for this disturbance seems to lie at the level of ATP-ase, because propranolol stimulates the membrane activity and supresses the citochondrial one. There are described some effects of this drug and its pharmocological opposite, isopropylenorepinephrine, on the liver cell enzymes, which may serve as a morphological proof of the antagonism between the mitochondrial and plasmalemal ATP-ase activity, on the one hand, and of the membrane ATP-ase and AMP-cyclase, on the other hand.

Adenosine Triphosphatases↗
PubMedDate not supplied

A microspectrophotometric study of the periodic acid-Schiff reaction product in the rat central nervous system.

The comparison of microspectrophotometric curves recorded from PAS-stained brain slices reveals clear-cut differences concerning the fixation method and the age of the animal, namely the colour is weaker in Carnoy-fixed tissue and in perinatal rats as referred to Bouin mixture and adult animals, respectively. It seems that the PAS-positive reaction in the rat brain is mainly due to glycolipids rather than to complex polysaccharides.

Animals↗
PubMedDate not supplied

Thymus quantitative morphological changes during CCl4-induced liver cirrhosis.

The dynamics of the thymus cell densities was studied during CCl4-induced cirrhogenic hepatopathy. The results show that all thymus compartments take part in immune phenomena occurring in the whole lymphatic system. The maximal intensity of thymus participation is attained in precirrhosis and evolutive cirrhosis. Within the cortical zone, the cell density pyroninophilia and blast-transformed cells increase during the first two months. After two months, there is a decrease of the pyroninophilic elements within the cortical zone, concomitantly with their increase at the medullary level, thus suggesting a migration process of the cells, which change the cortical-medullary ratio.

Animals↗
PubMedDate not supplied

Morphological aspects of the rat kidney preserved by cold storage. III. Ultrastructural aspects.

The ultrastructural changes of the white Wistar rat kidney, preserved by cold storage into two preservation media (Sacks and Plasmagel) are reported. For each medium two groups of kidney were used; for one of them the medium was used without additives and for the other stabilizing additives were added. The results showed the favourable effects of additives on the maintenance of the cellular ultrastructure during preservation, and more important the damages incurred when Plasmagel was used.

Aminocaproic Acid↗
PubMedDate not supplied

Morphological aspects of the rat kidney preserved by cold storage. I. Glomerular morphometric changes.

The absolute density of glomeruli in the microscopic field was determined in the rat kidney preserved by cold storage for 24, 48, 72 and 96 hrs in two different media: Sacks (hyperosmolar electrolytic solution of intracellular type) and Plasmagel (gelatin solution 4%). Progressive, statistically significant (p less than 0.01) decrease of glomerular density at 24 and 48 hrs was followed by return to initial values at 96 hrs. Decrease of the glomerular density was greater with Plasmagel.

Animals↗
PubMedDate not supplied

Morphological aspects of the rat kidney preserved by cold storage. II. The juxtaglomerular apparatus.

The present paper reports on the changes occurring in the juxtaglomerular apparatus during preservation of the rat kidney by cold storage, using two media: Sacks and Plasmagel, to which a membrane stabilizing "cocktail" was added (hydrocortisone, chlorpromazine, epsilonaminocaproic acid - EACA, propranolol). Evident alterations appeared at 48 hours more accentuated at 72 and 96 hours, and more intense when preserved in Plasmagel. The most affected structure in the juxtaglomerular apparatus was the macula densa, the epithelial cells having a more stable structure.

Aminocaproic Acid↗
PubMedDate not supplied

Morphological aspects of the rat kidney preserved by cold storage. IV. Histoenzymological changes. V. Endopeptidase activity.

Rat kidneys were preserved by initial washing and cooling perfusion, followed by cold storage at 6 degrees C for 24, 48, 72 and 96 hours, in two different media: Sacks (hyperosmolar electrolytic solution of intracellular type) and Plasmagel (gelation solution 4%). Evidence was found of DPNH-diaphorase, lactate dehydrogenase (LDH), leucylaminopeptidase (LAP) and adenosine-triphosphatase (ATPase) (pH 9.4) activities. Histoenzymological determination showed various levels of enzymatic activities in different segments of the nephron, levels relatively well maintained during storage, even at 72 and 96 hours. At the same time, cathepsin B and D and neutral proteinase activities were determined as parameters of maintained cellular enzymatic activity; different aspects were observed with the two preservation media used.

Adenosine Triphosphatases↗
PubMedDate not supplied

Cytochrome-oxidase and succinate dehydrogenase activity in the rat kidney preserved by cold storage, correlated with the study of mitochondrial suspension.

Succinate dehydrogenase (SDH) and cytochrome-oxidase (CO) activities were determined biochemically in the white rat kidneys after 24, 48, 72 hours preservation by cold storage. The investigations also included the study of infrastructural alterations in mitochondrial suspensions, separately for the medulla and the cortex. The comparison of the enzymatic activity curves showed a mirror-like aspect with a maximum at 24 hours for CO and a minimum for SDH, and a constantly more intense activity in the medulla.

Animals↗
PubMedDate not supplied

Gastric haemangiopericytoma with glomus-like pattern and review of the literature.

A case of gastric haemangiopericytoma with glomus-like pattern is reported. The patient, a 42-year-old man was admitted in surgery for acute circulatory failure after a penetrating bleeding cut wound of the abdomen. In the peritoneal cavity a small tumor was discovered on the lesser curvature of the stomach and was removed. This revealed a proliferation of relatively homogeneous pericytic elements, which delimited conspicuous vascular spaces. Some cells, individual or clustered, lay in an amorphous, myxomatous or hyaline matrix (glomus-like pattern). A review of the literature and histogenetic hypotheses are discussed.

Adult↗