Biomedical subjects

J Lazar

Publications and source records attributed to J Lazar.

At least 37 records · Page 2Linked to original sources

PubMed1992

[Structural basis of appendiceal function in rabbits].

Enzymo-, immuno- and lactin-histochemical methods were used to study the structure of the rabbit appendix wall. The value of some structural components in the function of this part of the intestine is discussed. Some findings were documented electronmicroscopically. In addition to its resorptive function, the rabbit appendix is equipped with a potent defense mechanism against adverse environmental effects of the appendix content. Individual structures of this defensive barrier are closely characterized with regard to cellular equipment and possibilities of its morphological identification.

Animals↗

PubMed1987

Serum angiotensin converting enzyme activity in evaluation of patients with liver disease.

This study was undertaken to evaluate angiotensin converting enzyme activity in patients with liver disease, and to explore its relationship to thyroid function in patients with liver disease. Serum angiotensin converting enzyme activity and thyroid hormone levels, determined in 79 patients with intrahepatic-type liver disease and 18 patients with extrahepatic biliary obstruction, were compared with values in 129 euthyroid controls. Serum angiotensin converting enzyme activity was higher in intrahepatic disease than in extrahepatic obstruction, but statistically significant only for acute intrahepatic disease. In the patients studied, high serum angiotensin converting enzyme activity (22 units/ml or more) virtually excluded extrahepatic biliary obstruction, with a negative predictive value of 94 percent. Low serum angiotensin converting enzyme activity had a positive predictive value for extrahepatic obstruction of only 67 percent. Increased angiotensin converting enzyme activity could not be explained as a function of enhanced thyroid activity. Serum angiotensin converting enzyme activity may be useful in separating patients with intrahepatic liver disease from those with extrahepatic obstruction.

Cholestasis, Extrahepatic↗

PubMed1985

Liquid-chromatographic assay of cimetidine in plasma and gastric fluid.

In this micro-scale method for liquid-chromatographic measurement of cimetidine in 250-microL volumes of plasma or gastric fluid, a combination of organic- and aqueous-phase extractions, and protonation of the internal standard and cimetidine, enabled us to detect 2.0 ng of cimetidine on the column. We also used a radial compression module, which reduced the retention times for cimetidine and the internal standard to only 2.78 and 2.00 min. The speed and sensitivity of this method facilitates analysis of large numbers of samples.

Chromatography, High Pressure Liquid↗

PubMed1982

Age, response complexity, and target consistency in visual search.

Adult age differences in visual search were examined under manipulations of target set consistency (fixed versus varied), response complexity (2 versus 4 sorting categories), display size (1, 4, or 8 letters/card), and sessions (2). Mean card sorting times of 20 young (mean = 22 years) and 20 elderly (mean = 62 years) adults were compared. Significant main effects of age, complexity, consistency, sessions, and display size were obtained. A consistent target set facilitated search independent of response complexity. As predicted, significant interactions indicated that age differences in search were eliminated under the fixed set procedure but not under the varied set procedure.

Adolescent↗

PubMed1980

An inhibitor of arachidonic acid metabolism stimulates luteinizing hormone (LH) release from cultured pituitary cells.

5, 8, 11, 14 eicosatetraynoic acid ("ETYA", Roche 3-1428) is a competitive inhibitor of arachidonic acid metabolism. It effectively inhibits the action of both the lipoxygenases and the fatty acid cyclooxygenases both of which utilize arachidonic acid as a substrate. In the present work, we have shown that ETYA stimulates luteinizing hormone (LH) release from cultured pituitary cells (ED50 = 10 micrograms/ml). Stimulation is not due to contaminants present in the preparation, since highly purified ETYA (characterized by GC-MS) stimulates release, while contaminants removed by silicic acid chromatography do not. In addition, neither oxidized solutions of ETYA nor arachidonic acid itself stimulate LH release. ETYA stimulated release is dose dependent and is inhibited by ions which antagonize Ca2+ action. The observation that neither indomethecin (10, 100 micrograms/ml) nor meclofenamate (1.0, 10 micrograms/ml) stimulate LH release suggests that the effect of ETYA cannot be explained by an action on cyclooxygenase. The action of ETYA may be mediated either via an effect on lipoxygenase or through some nonspecific action (such as altered membrane fluidity).

5,8,11,14-Eicosatetraynoic Acid↗

PubMed1974