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Biomedical subjects

E Urban

Publications and source records attributed to E Urban.

At least 55 records · Page 3Linked to original sources
PubMed1981

Abnormal visual-evoked responses and opsoclonus.

A 73-year-old woman presented with classic opsoclonus two weeks following an acute febrile illness. Four weeks later a complete clinical recovery was evident. Six weeks after onset of the problem, or 2 weeks after resolution of the abnormal eye movements, a pattern reversal visual evoked response showed a delayed response in both eyes and had an unusually high amplitude. For the next 2 months the patient complained of occasional blurring of vision. A repeat visual evoked response test after 4 months revealed normal latency and amplitude in both eyes. The possible mechanisms for the visual evoked response abnormality are discussed.

Aged↗
PubMed1981

[Viability of chicken Mallophaga following loss of their host].

Eomenacanthus stramineus, Menopon gallinae, and Goniocoles gallinae were found to have a different locomotive ability after losing contact with their host. Speed and character of the locomotion depend on vitality, leg anatomy, locomotive mechanism, and external factors, e.g. roughness of the substrate. Viability and mortality of the three Mallophaga species were investigated on such substrates as are normally found in poultry houses. The results suggest an active infectiosity of Eomenacanthus stramineus amd a passive one of Menopon gallinae and Goniocotes gallinea among hosts.

Animals↗
PubMed1980

Inhibition of testicular organization in vitro by newborn rat ovarian cell supernatants.

Cell reorganization experiments performed with newborn rat gonadal single cell suspensions resulted in organ-like reorganization after 18 h of rotation culture. When, however, testicular cells were incubated in supernatants of newborn rat ovarian cells, testicular organization was suppressed and the architecture of the reorganized gonad was rather feminine. Supernatants of adult rat ovarian cells did not inhibit testicular organization. The possible mechanisms responsible for the failure of the function of H-Y antigen by the presence of ovarian cell supernatants of newborn rats are discussed.

Animals↗
PubMed1980

Mammalian cross-reactive H-Y antigen induces sex reversal in vitro in the avian testis.

Testes of either newborn rats or newly hatched chickens, dissociated into single cell suspensions, reorganize in vitro into their histotypic structures. In birds, the heterogametic female sex is H-Y antigen positive, and not the male as in mammals. Cocultivation of rat and chicken testicular cells results in the reorganization of an ovotestis. A similar result is obtained after cultivation of chicken testicular cells in the supernatant medium of cultured human male Burkitt lymphoma Daudi cells. Rat testicular Sertoli cells as well as Daudi cells are a source of H-Y antigen. The simultaneous application of H-Y antigen and anti-H-Y antiserum prevents ovotestis formation. It is concluded that H-Y antigen which is known to be testis-organizing in mammals, is the ovary-organizing factor in birds.

Animals↗
PubMed1980

Extensive small bowel resection in the rat: lack of effect on serum proteins.

Rats were subjected to serial venesections 3 days prior to and then sequentially for 4 weeks after surgical removal of either the proximal or distal half of the small bowel. Total serum protein concentration and protein electrophoretic patterns were determined on these sera. Both sham-operated and unoperated animals served as controls. The data showed differences in serum proteins in the first week after operation between the three groups of operated rats and the unoperated controls. However, there were no significant differences in serum proteins between the sham-operated and the two types of resected animals. This indicates that the combined effects of laparotomy, anesthesia, pre- and postoperative fasting outweighed any additional early effects of loss of 50% small bowel on serum proteins. The study also demonstrates the necessity of having both unoperated and sham-operated control groups in designing experiments involving surgical extirpation of intestine.

Animals↗
PubMed1978

Calcium transport by the normal rat colon in vivo and in vitro.

We studied calcium transport in vivo and in vitro in large bowel of normally fed young male rats. Solutions containing zero, 1.7, 3.4 and 5.0 mM calcium and isotopic 45Ca as tracer were perfused in vivo through the lumen of cecum and descending colon. In vitro flux studies were also carried out in cecum with 2.0 and 0.2 mM calcium solutions utilizing the technique of Ussing and Zerahn whereby both chemical and electrical gradients across planar sheets of cecal tissues were nulled. The combined findings demonstrated that (i) cecum was more permeable to calcium than descending colon indicating a proximal to distal absorption gradient in large bowel; (ii) the transport of calcium in both segments increased with increasing luminal calcium concentration, and (iii) calcium transport in both cecum and descending colon was passive only. Thus the large bowel appears to play only a minor role in calcium homeostasis in the normally fed rat.

Animals↗
PubMed1977

Failure of lactose and glucose to influence in vivo intestinal calcium transport in normal rats.

The influence of luminal lactose and glucose on intestinal calcium transport was examined in vivo in normal post-weaned young rats. In situ segments of duodenum, midgut and ileum were perfused through the lumen for 1 h with an isotonic solution of 3.4 mM calcium containing radioactive isotopic 45Ca as tracer and additionally either 10 mM lactose or 10 mM glucose, or, for the control group, no saccharide. Net absorption was measured by disappearance of luminal calcium; lumen-to-plasma flux was determined from the disappearance of tracer 45Ca. This concentration of luminal lactose or glucose had no direct effect on calcium transport under these steady state conditions.

Animals↗
PubMed1975

Calcium-binding activity of rat intestinal mucosa after massive small bowel resection.

Male Sprague-Dawley rats underwent resection of 50 cm of either proximal or distal small intestine or sham-operation. 6-7 weeks after operation mucosal calcium-binding activity was measured in segments of duodenum ileum and remaining 'midgut'. Similar measurements were obtained from weight and age-matched unoperated rats. There was no difference in calcium-binding activity between unoperated and sham-operated animals. After proximal resection the binding activity increased significantly in duodenum and midgut but did not change in ileum. After distal resection the binding activity decreased in duodenum but was unchanged in midgut and ileum. These studies show that mucosal calcium-binding activity undergoes changes but alteration of the binding activity in remaining gut varies with the location of the small bowel resection.

Animals↗
PubMed1975

Serum proteins in the rat after extensive proximal or distal small bowel resection.

Rats underwent surgical removal of either the proximal or distal half of the small bowel. 5-6 weeks later, total protein concentrations and electrophoretic patterns were determined in sera from the two groups of resected animals. The data compared to similar measurements from sham-operated and unoperated control groups, showed no differences between resected or control animals. This indicates re-establishment of overall nutritional adequacy by this time interval after substantial loss of either proximal or distal small intestine.

Alpha-Globulins↗