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Biomedical subjects

G L Wright

Publications and source records attributed to G L Wright.

At least 145 records · Page 8Linked to original sources
PubMed1981

Spontaneous hypertension ion cross-suckled rats.

Genetically normotensive Sprague-Dawley rats nursed by spontaneously hypertensive foster mothers develop sustained high blood pressure. Some factor related to the genetically programmed hypertension of the foster mother is probably transmitted to the infant rats through her milk. Alternatively, the hyperkinetic behavior of the mother may activate a hypertensinogen in young having the proper constellation of genes.

Animal Population Groups↗
PubMed1981

Leukocyte migration inhibition assay in patients with prostate adenocarcinoma.

The leukocyte migration inhibition (LMI) assay was used to determine the cell-mediated immune reactivity of prostate cancer patients to putative tumor antigens present in potassium chloride extracts of surgically removed prostate tumor tissue. Using an extract prepared from prostate tumor tissue, inhibition of leukocyte migration was found more frequently in prostate tumor patients (61%) than in patients with benign prostate hyperplasia (37%), patients with nonprostate cancers (26%), or normal donors (10%). Control extracts prepared from normal prostate tissue, benign prostate hyperplasia tissue, and unrelated tumor tissue were statistically less reactive in the LMI assay than the prostate tumor extract when reacted against leukocytes from prostate tumor patients. These results suggest that the LMI assay might be potentially useful for measuring the tumor-directed, cell-mediated immune responses in patients with prostate cancer.

Adenocarcinoma↗
PubMed1981

Corpus luteum function after follicle aspiration for oocyte retrieval.

Follicle aspiration for in vitro fertilization is associated with a statistical disruption of the luteal phase. The severity of the disruption seems to be in relation to the vigorousness and the number of aspirations and therefore the number of granulosa cells that are dislodged from the membrana granulosa layer. Although the statistical importance of this disruption from a biologic point of view does not seem to be significant, as measured by the length of the luteal phase, an analysis of individual cases must be made in order to determine the frequency with which a biologically significant luteal defect may be produced. At the present time, it seems that the fewer the granulosa cells removed at aspiration, the less the luteal disruption will be. The series is discounted as an important factor in inducing luteal dysfunction.

Corpus Luteum↗
PubMed1981

The vascular sensitizing character of plasma from spontaneously hypertensive rats.

Experiments were conducted to examine the effects of plasma from spontaneously hypertensive rats (systolic blood pressure (SBP) = 183 torr; 1 torr = 133.322 Pa) on the contractile properties of aortic strips from normotensive rats. While incubated in plasma from spontaneously hypertensive (SH) rats, the aortic strips of normotensive rats exhibited hyperresponsiveness to norepinephrine (NE) compared with those incubated in plasma obtained from Wistar-Kyoto (SBP = 128 torr) or Sprague - Dawley (SBP = 110 torr) rats. The washout of plasma and perfusion of the aortic strips with Krebs bicarbonate solution abolished the effect of SH plasma on the reactivity to NE but not potassium, suggesting a residual hypersensitivity. The comparison of these findings with results obtained for contractions of aortic strips in Krebs bicarbonate solution containing high and low levels of calcium indicated the effect of SH plasma on vascular tissue sensitivity was not directly related to an alteration in plasma levels of calcium.

Animals↗
PubMed1981

Transport of calcium by duodenum of spontaneously hypertensive rat.

The absorption of calcium by segments of duodenum obtained from spontaneously hypertensive (SH) rats and normotensive Wistar-Kyoto (WKy) rats was measured before and after the development of hypertension. The systolic blood pressure (SBP) of 5-wk-old SH rats (116 +/- 4 Torr) was significantly elevated above that of age-matched WKy rats (103 +/- 3 Torr) but was not at a level generally considered to be hypertensive. Values obtained for calcium transport [ratio of serosal-to-mucosal fluid 45Ca2+ concn (S/M ratio)] from everted duodenal sacs were similar between the two groups at this age. At 12 wk of age, SH rats exhibited a SBP (153 +/- 4 Torr) well above that of WKy controls (127 +/- 3 Torr), and calcium S/M ratios for duodenal sacs were significantly greater than the WKy control values. Similarly, the in vivo uptake of calcium in duodenal segments was significantly elevated in 12-wk-old SH rats compared with WKy controls. The administration of vitamin D3 or its metabolite, 25-hydroxycholecalciferol, had no detectable effect on duodenal transport of calcium in 12-wk-old SH or WKy rats. By comparison, 1,25-dihydroxycholecalciferol produced a significant increase in duodenal calcium transport both in vitro and in vivo in WKy but not in SH rats. The results indicate a distinct abnormality in the transport of calcium in the duodenum of SH rats, suggesting that the decrease in duodenal uptake of calcium that normally occurs with maturation is slow to develop in this rat strain.

Animals↗
PubMed1981

Comparison of countercurrent immunoelectrophoretic assay with commercial radioimmunoassay kits for measuring prostatic acid phosphatase.

We evaluated and compared five commercial radioimmunoassay kits with a standard counter-immunoelectrophoretic assay for the measurement of prostatic acid phosphatase in serum. Four of the five radioimmunoassays performed as described by the supplier with respect to sensitivity, stability, precision, linearity, analytical recovery, and expected values for the normal male population. None of the radioimmunoassays was more clinically sensitive then the counter-immunoelectrophoretic assay for detecting increased prostatic acid phosphatase in serum. Results obtained by counter-immunoelectrophoretic assay agreed with results obtained by radioimmunoassay in 96% of the tests. The proportion of positive results in patients with confirmed prostatic adenocarcinoma increased with disease progression. The fewer positive tests in localized adenocarcinoma (Stages A and B) suggests that neither the counter-immunoelectrophoretic assay nor the radioimmunoassay procedures are useful for screening unselected populations for adenocarcinoma of the prostate. The high percentage of normal values found in those patients clinically free of disease after treatment is encouraging and supports the use of the prostatic acid phosphatase immunoassays in prospectively monitoring the treatment of prostatic cancer patients.

Acid Phosphatase↗
PubMed1981

Prediction of the time of ovulation.

Prediction of ovulation was established by correlation of clinical parameters, follicular development by ultrasound, and estradiol, progesterone, and luteinizing hormone (LH) determination in 71 menstrual cycles. Laparoscopic follicular aspiration was accomplished in 41 of those cycles. A 28-hour interval from the ascending limb of the LH seems to be the "ideal time" for retrieval of a preovulatory oocyte. The variability in the amount of LH to which the follicle is exposed during the LH surge seems to indicate that there is a relatively low specific value necessary for ovulation. Ovulation occurs approximately 10 +/- 5 hours from the LH peak. Progesterone occurs in relation to the LH surge and is helpful for the retrospective analysis of the menstrual cycle.

Adult↗
PubMed1981

Proteolysis and recycling of Mycobacterium tuberculosis culture filtrate tuberculoproteins.

The culture filtrate of Mycobacterium tuberculosis H37Ra has proteolytic enzyme activity which can hydrolyse extracellular tuberculoproteins. Some of the released products are transported into the cells and are incorporated into cell protein, and finally reappear in the culture filtrate as constituents of secondary tuberculoproteins. Continued extracellular proteolysis and utilization of the resultant products could produce a cyclic source of culture filtrate tuberculoproteins.

Bacterial Proteins↗
PubMed1980

Polyvalent antisera to Pseudomonas ribosomal vaccines: protection of mice against clinically isolated strains.

The preparation of polyvalent antisera to ribosomal vaccines from Pseudomonas aeruginosa is described. The ability of these antisera to protect mice by passive immunization against challenge with randomly chosen, clinically isolated strains of P. aeruginosa is reported. Significant protection was achieved against 34 of 40 strains tested (85%). Included among these strains against which protection was achieved were four mucoid strains. In addition, the degree of cross-protection attainable by the ribosomal vaccines was investigated. The results obtained indicated that these vaccines are generally serotype specific.

Animals↗
PubMed1980

Effect of heat exposure on in vitro intestinal transport and utilization of glucose in the rat.

Intestinal transport and utilization of glucose were studied in vitro in chronically heat-exposed (Ta = 34 degrees C) rats. Despite mucosal tissue per centimetre being significantly reduced following 7 and 14 days of exposure, no differences from control values were noted in full serosal to mucosal (S/M) fluid glucose concentrations ratios obtained from everted sac preparations. Measurements on 40-cm jejunal segments perfused in vitro at days 13-15 showed a reduction in the rate of glucose absortpion per centimetre of intestine, while glucose absorption per gram of tissue was unaltered in heat-exposed rats. At the same time, glucose secretion at the serosal surface was unchanged as calculated per centimetre of intestine and increased when calculated per gram of dry tissue. The utilization of glucose by the intestine was found to be significantly reduced whether expressed for intestinal length or for intestinal weight. In addition, the glucose concentration of the tissue water was elevated in intestinal segments of heat-exposed rats after 60 min of perfusion. The decrease in glucose uptake per centimetre of intestine was attributed to the decrease in mucosal tissue. Elevated tissue glucose concentration and enhanced translocation of glucose to the serosal surface were attributed, at least in part, to the decreased rate of glucose metabolism observed in intestines of heat-exposed rats.

Animals↗
PubMed1980

The concentrations of ionic and total calcium in plasma of the spontaneously hypertensive rat.

The levels of ionic calcium in whole blood obtained from male spontaneously hypertensive rats (SHR) were slightly decreased compared with normotensive animals during the early stages of blood pressure elevation and in older (28-32 weeks) animals with established hypertension. During these intervals the total calcium concentrations of plasma were not significantly different although the ratios of ionic to total calcium were similar between SHR and control groups. In contrast with male and female SHR showed ionic calcium levels similar to normotensive control rats whereas total calcium concentrations in plasma increased with age and blood pressure elevation. The addition of calcium to plasma in 4- to 5-week-old SHR and normotensive rats revealed a buffering action in terms of the elevation in ionic calcium concentrations. The buffering capacity of plasma from normotensive animals did not change markedly but appeared to be greatly reduced in SHR by 17-25 weeks of age. Similarly, significant elevations in ionic calcium but not total calcium were observed following the injection of calcium in SHR compared with normotensive controls. The minor reductions in ionic calcium levels in blood seen in male SHR and the lowered ionic:total calcium ratios in female SHR may indicate enhanced binding or complexing of exogenous calcium. In view of these findings, the apparent reduction in in vitro and in vivo binding or complexing of exogenous calcium may reflect a decreased availability of sites for association with the calcium ion. The poor correlation between changes in blood pressure and ionic calcium suggested, however, that the disturbance in ionic or total calcium levels of plasma was not a primary causal factor in the development of hypertension.

Age Factors↗
PubMed1980

Thermoregulatory ability of female rats during pregnancy and lactation.

Thermoregulatory ability of female rats was examined before pregnancy, during gestation, and during lactation. Thermoregulatory pattern, colonic temperature, evaporative water loss, and survival time were monitored during terminal heating (39.5 +/- 0.9 degrees C) designed to allow prolonged survival (3-4 h) with a sustained thermoregulatory effort. Results confirmed our previously reported observation of decreased thermoregulatory ability in lactating dams, with evidence suggesting thermoregulatory impairment during late gestation. Lactating dams displayed a type III thermoregulatory pattern, and established a rate of evaporative water loss effective for thermostasis at an elevated colonic temperature. However, survival time was significantly decreased compared to nonreproducing females. In contrast, prior heat acclimation tended to increase the survival time of lactating dams. It was concluded that the reduction in thermoregulatory ability observed in lactating dams was related to their inability to maintain a rate of evaporative water loss effective for thermostasis at an elevated colonic temperature.

Adaptation, Physiological↗
PubMed1980

Analytical gradient polyacrylamide gel-crossed line immunoelectrophores. A technique for locating species specific Mycobacterium tuberculosis H37RV antigens in polyacrylamide gel columns.

Analytical gradient polyacrylamide gel electrophoresis of antigens from Mycobacterium tuberculosis H37RV was combined with crossed line immunoelectrophoresis to locate the position of antigens in polyacrylamide gel columns that appeared to be specific for M. tuberculosis H37RV. Specificity was established by comparing H37RV with M. kansaii CE in the electrophoretic procedure and the relative mobility (Rm) values are being used in an effort to recover and enrich specific antigens from preparative gel columns. Such fractions should be more suitable in efforts to recover purified monospecific components from M. tuberculosis H37RV.

Antigens, Bacterial↗