Biomedical subjects

I Sils

Publications and source records attributed to I Sils.

3 recordsLinked to original sources

PubMed1999

Flow cytometric method using fluorescent microspheres to measure reticuloendothelial function or particulate translocation.

The reticuloendothelial system (RES) influences the outcome of vascular shock and environmental stress. We describe a procedure that employs flow cytometry and 1 microm fluorescent microspheres (FM) to study RES function. FM (2 x 10(10) beads/kg) were administered via a jugular cannula in Sprague-Dawley rats. After 15 min, blood and tissues were collected and digested in 15% KOH. Phycoerythrin 1 microm beads were added to each sample as an internal standard and analyzed by flow cytometry. FM were preferentially cleared by the spleen, liver and lung. Clearance was confirmed by fluorescent photomicroscopy. Addition of the internal standard to determine accurately aspiration volume enhanced precision. This procedure offers advantages over other RES clearance methods including bacterial, radioactive or carbon clearance assays. Moreover, this method could enhance accuracy, reproducibility and speed of data collection in particulate transport studies that are based on manual microscopic scanning and FM counting.

Animals↗

PubMed1987

Urinary and hematologic indexes of hypohydration.

As part of a large-scale field feeding system test we were able to collect and study hundreds of aliquots of overnight urine samples obtained immediately prior to a fasting blood sample on days 1, 20, and 44 of the field test. The large number of experimental samples (greater than 650) and concomitant collection of blood and urine aliquots along with data on body weights gave us the opportunity to assess and quantitate the sensitivity of commonly used criteria of hypohydration. Urine aliquots for all test days were initially categorized by specific gravity (SG) greater than or equal to 1.03 (n = 124) or less than 1.03 (n = 540). Creatinine levels were elevated (P less than 0.001) in the concentrated urine samples, but a decreased trend in sodium-to-potassium ratios in these samples failed to achieve statistical significance (P greater than 0.05). However, when individuals with high SG urine were subclassified by a criterion of weight loss greater than 3% from original body weight, then creatinine concentrations were elevated (P = 0.05), whereas sodium-to-potassium ratios were decreased (P = 0.05) when subjects also with high SG but weight loss less than 3% were compared. Because of the moderate altitude (2,000 m) of the field site and the time of sojourn (44 days), there occurred a slight, but significant (P less than 0.001), erythropoietic response. Hematocrit and serum osmolality were not significantly different when examined by the criteria of high or low SG urine and weight loss greater than or less than 3% original body weight.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Urea Nitrogen↗

PubMed1978

Role of physical effort in the etiology of rat heatstroke injury and mortality.

A total of 171 untrained, unacclimatized, and unanesthetized rats were used to evaluate the effects of sedentary and work-induced hyperthermia on the incidence of mortality and cellular injury, 24 h postexposure. Cellular injury was defined as serum transaminase activity (SGPT and SGOT) exceeding 1,000 IU/l (heatstroke levels). Both the percent mortality and the percentage of 24-h survivors with transaminase levels above 1,000 IU/l were plotted against maximum core temperatures. Exertion-induced hyperthermia produced a significantly higher incidence of cellular injury and heatstroke death at lower core temperatures than hyperthermia alone. With hyperthermia only, the SGPT and SGOT dose-response curves were identical. When work was combined with hyperthermia, there was a greater incidence of elevated SGOT at lower core temperatures. These curves bore a striking resemblance to curves reflecting heat- and/or work-induced mortality in humans. The results suggest a direct role of physical effort in causing heatstroke injury and mortality.

Alanine Transaminase↗