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Biomedical subjects

V Popescu

Publications and source records attributed to V Popescu.

At least 19 recordsLinked to original sources
PubMed1979

The effects of short-term exposure to crowding stress on the pancreatic islets morphology and glycemia in mice.

Behavior, pancreatic islets morphology and plasma glucose levels of male mice exposed for 2, 4, 24 and 48 hours to crowding stress were investigated. The crowding induced an intense turmoil state associated with enhanced irritability and aggressiveness among the specimens of all experimental groups. Violent fights occurred especially in the first 4--6 hours, generally with the death of 1--2 individuals from each group. The changes recorded in the pancreatic islets affected first (2 hours) exclusively the insulin-producing cells, and in subsequent intervals they progressively expanded over all cell types. The changes occurred during the experiment in all islet cell types; however the B-cells showed by far the most pronounced alterations irrespective of the studied time interval. Most changes suggested the stimulation of the entire gland secretory activity, but particularly of B-cells, which was also proved by low glycemia values recorded at 3 of the 4 crowding time intervals. On the other hand, some alterations, occurring first at 24 hours, were regarded as signs of a moderate B-cells secretory hypoactivity; they may partly support the slight hyperglycemia obtained at this time interval. The significance of the above short-term observations in the induction of glycoregulation disturbances, diabetes included, as well as the presumably mediation role of adrenal-cortex and -medulla hormones under stress conditions are discussed and correlated with findings reported in literature.

Animals↗
PubMed1978

The effects of crowding stress on the pancreatic islets morphology in golden hamsters.

Behavior and the pancreatic islets morphology of golden hamsters exposed for different periods (24 h, 15 and 30 d) to crowding stress were investigated. The crowding induced an intensive turmoil and enhanced irritability and aggressiveness, particularly among the female specimens. Within a week, a rank hierarchy seemed to establish and therefore, later the fighting incidence was more reduced. Marked morphological alterations were recorded in the endocrine pancreas, affecting in various degrees all cell types, but especially the insulin-producing cells. The B-cells showed increased sizes, higher incidence of mitotic divisions, a drastical reduction of secretory granules amounts, enlargement of GOLGI complexes, mitochondria swelling and extension of the ergastoplasm. On the other hand, after 30 d, part of these cells displayed pycnotic nuclei, large cytoplasmic vacuoles and increased number of lasosomes and lipid inclusions. Due to the B-cell hyperplasia, the relative number of both A1- and A2-cells per islet occurred diminished and their typical localization modified. The islets of 15 and 30 d crowded specimens showed enlarged sinusoids and clear peri-insular spaces. The above morphological modifications, which suggest as a whole the global stimulation of gland secretory activity, are presented in relation with other authors findings. The presumably involvements of adrenal-cortex and -medulla hormones in the mediation of stress-induced glycemic and pancreatic alterations are discussed.

Animals↗
PubMed1977

Effects of cerebral lateral, ventricular infusions of phloridzin on feeding and body weight in Gallus domesticus (L.).

Contrary to earlier findings in rats, cerebral lateral ventricular infusions of 1 X 10(-3) M or 2 X 10(-3) M solutions of phloridzin at a rate of 2.5 micronl/min for 90 min had no significant stimulating effects on food intake and weight gain in hens and cocks. These different responses to intraventricular phloridzin might reflect a difference of sensitivity to the inhibitory action of phloridzin on glucose transport in cerebral cells or certain peculiarities of mechanisms controlling food intake in chickens.

Animals↗
PubMed1977

On the carbohydrate metabolism of pectoral muscle in the ontogeny of chicken.

1. Immediately after hatching, the pectoral muscle has a low glycogen content, and exhibits very low glycogen and high glucose and oxygen consumptions. 2. Drastic metabolic changes occur during the second day and again during the second week of life ("critical periods of the ontogenesis"); the above metabolic pattern is reversed. 3. The insulin sensitivity of the muscle is very low during these critical periods, and high between them. 4. The overall trend of metabolic ontogenesis in the pectoral muscle of the domestic fowl (non-flying bird) seems to have no functional but genetical determination.

Animals↗
PubMed1977

Treatment of temporo-mandibular ankylosis with particular reference to the interposition of full-thickness skin autotransplant.

In the treatment of the temporo-mandibular ankylosis, the maintainance of separation between the temporal and mandibular raw surfaces, after osteotomy of the bony fusion, constitutes the key to the prevention of recurrence; the great potential of bone to reform is acknowledged by all those who are experienced in this problem. Analysing 168 temporo-mandibular arthoplasties in which different methods have been used in order to maintain the newly created joint space, the causes of failures have been brought out and the difficulties studied. The conclusion is reached that the best results were obtained by the interposition of autogenous full thickness skin. The surgical technique is briefly presented as well as the records regarding the cases followed-up for a period of 2 to 19 years, illustrating the anatomical and functional conservation of the new joints. The experimental investigations concerning the behaviour and fate of the buried skin autotransplants complete the clinical studies, proving the qualities and the value of full thickness skin as an interposition material in arthroplasties.

Adolescent↗
PubMed1976

[Etiopathogenesis of varicocele and therapeutic conclusions].

The many pathogenic theories for varicocele, mostly hypothetic, have shown the uncertainty of the cause of the disease including the use of the word "essential". Anatomical, phlebomanometric and phlebographic studies determined the main cause of varicocele, the short course of the aorto-mesenteric artery which, by stricture of the left renal vein in the standing position, produces reno-spermatic venous reflux producing varicose dilatation of the left spermatic plexus and, thus, varicocele. In addition to this main cause, the vascular background with a qualitative deficiency of the connective tissue and prolonged standing during work, are the main factors which favour the onset of varicocele. An active, early therapeutic attitude and high ligature of the left spermatic vein give the best results.

Humans↗
PubMed1975

Vertical osteotomy of the ascending rami in mandibular retrognathism.

The authors present their experience and conclusions regarding surgical lengthening of the mandible in retrognathism due to bone hypo-development. Thus, in hypotrophies of the ascending ramus, especially in temporo-mandibular ankylosis, they use a longitudinal osteotomy (Popescu 1949); various technical adaptations of this method, in different situations, are described, as well as their association with osteoplasty, utilizing iliac bone grafts or the hypertrophic chin prominence. In retrognathism due to hypo-development of the mandible, when the ascending rami have a good conformation, sagittal osteotomy (Obwegeser 1957, Dal Pont 1961) is preferred.

Ankylosis↗