8 Matching Results

Search Results

Advanced search parameters have been applied.

Metabolism of Hydrocortisone by X-Irradiated Rat Liver Tissue as Determined by the Porter-Silber Chromagen Method

Description: The present study may be considered endocrinological and radiobiological in nature. The endocrinology phase was concerned with studying the changes in endocrine function following the application of a stress agent. X-irradiation was chosen as the stressor in order to determine any difference in effect of this stressor from others which have been studied, e. g. heat, cold, metabolic poisons. Liver slices taken from rats at various time intervals following whole body X-irradiation were tested for their ability to metabolize hydrocortisone from a Krebs-Ringer solution.
Date: August 1959
Creator: Pryor, Nan Webb
Partner: UNT Libraries

Psychological Hardiness and Biochemical Markers of Acute Stress

Description: The establishment of physiological norms for psychologically hardy vs. non-hardy individuals was attempted by examination of levels of salivary cortisol and urinary norepinephrine before and after a mid-term examination stressor. Normative data was collected on the reported frequency of stressors and their severity one week prior to the examination, and self-reported ratings of stress immediately prior to the examination. Performance on the examination as a function of hardiness was explored. Associations between demographic variables and psychological hardiness were also studied. Results from this study were inconclusive in establishing physiological norms for psychologically hardy individuals. Associations were found between: 1) hardiness and frequency of stressors; 2) hardiness and age; and 3) self-reported ratings of stress and anxiety as measured by the State-Trait Anxiety Inventory (STAI).
Date: August 2001
Creator: McCoy, Paula K.
Partner: UNT Libraries

Two distinct phases of apoptosis in mammary gland involution: proteinase-independent and -dependent pathways

Description: Postlactational involution of the mammary gland is characterized by two distinct physiological events: apoptosis of the secretory, epithelial cells undergoing programmed cell death, and proteolytic degradation of the mammary gland basement membrane. We examined the spatial and temporal patterns of apoptotic cells in relation to those of proteinases during involution of the BALB/c mouse mammary gland. Apoptosis was almost absent during lactation but became evident at day 2 of involution, when {beta}-casein gene expression was still high. Apoptotic cells were then seen at least up to day 8 of involution, when {beta}-casein gene expression was being extinguished. Expression of sulfated glycoprotein-2 (SGP-2), interleukin-1{beta} converting enzyme (ICE) and tissue inhibitor of metalloproteinases-1 was upregulated at day 2, when apoptotic cells were seen initially. Expression of the matrix metalloproteinases gelatinase A and stromelysin-1 and the serine proteinase urokinase-type plasminogen activator, which was low during lactation, was strongly upregulated in parallel starting at day 4 after weaning, coinciding with start of the collapse of the lobulo-alveolar structures and the intensive tissue remodeling in involution. The major sites of mRNA synthesis for these proteinases were fibroblast-like cells in the periductal stroma and stromal cells surrounding the collapsed alveoli, suggesting that the degradative phase of involution is due to a specialized mesenchymal-epithelial interaction. To elucidate the functional role of these proteinases during involution, at the onset of weaning we treated mice systemically with the glucocorticoid hydrocortisone, which is known to inhibit mammary gland involution. Although the initial wave of apoptotic cells appeared in the lumina of the gland, the dramatic regression and tissue remodeling usually evident by day 5 was substantially inhibited by systemic treatment with hydrocortisone. mRNA and protein for gelatinase A, stromelysin-1 and uPA were weakly induced, if at all, in hydrocortisonetreated mice. Furthermore, mRNA for membrane-type matrix metalloproteinase decreased after hydrocortisone treatment ...
Date: January 1, 1996
Creator: Lund, Leif R; Romer, John; Thomasset, Nicole; Solberg, Helene; Pyke, Charles; Bissell, Mina J et al.
Partner: UNT Libraries Government Documents Department

Pacific Lamprey Research and Restoration Project : Annual Report 1999.

Description: This report summarizes results of research activities conducted from 1996 through 1999. The findings in these chapters represent the efforts of the Confederated Tribes of the Umatilla Indian Reservation (CTUIR) and collaborative efforts among other researchers working on Pacific lampreys (Lampetra tridentata) under this project. The findings in these chapters will help management and recovery of Pacific lampreys in the Columbia River Basin. Traditional Ecological Knowledge (TEK) of Pacific lampreys from tribal members within the Confederated Tribes of the Umatilla Indian Reservation was useful in gaining baseline life history information. Tribal members described harvesting two types of lampreys from spring through fall, the short brown type and the long dark type. Lamprey spawning distribution was from the mouth to the headwaters in the Umatilla River. Larval lampreys were observed in the mud and sand areas of the river. Tribal members observed major declines in lampreys within the Columbia River basin. Larval Pacific lampreys were distributed throughout the John Day River basin. Larval distribution in the other subbasins was patchy and limited to the lower reaches of the streams. Larval densities were highly variable in the Middle Fork John Day and North Fork John Day rivers, as opposed to the Main stem John Day River. Larval lengths varied little in the Middle Fork John Day and North Fork John Day rivers, but were highly variable in the Main stem John Day River. Larval abundance decreased as we moved upstream in the Columbia and Snake rivers. In addition, we found strong evidence for lack of larval recruitment as distance increased from the mouth of the Columbia River. We identified clinical indicators of stress in adult Pacific lampreys. Plasma glucose became elevated soon after acute stress and remained elevated for one week. Plasma lactate also became elevated by 30 minutes; however, it decreased ...
Date: October 1, 2001
Creator: Close, David A.
Partner: UNT Libraries Government Documents Department

Migratory Characteristics of Spring Chinook Salmon in the Willamette River : Annual Report 1991.

Description: This report documents our research to examine in detail the migration of juvenile and adult spring chinook salmon in the Willamette River. We seek to determine characteristics of seaward migration of spring chinook smolts in relation to oxygen supplementation practices at Willamette Hatchery, and to identify potential sources of adult spring chinook mortality in the Willamette River above Willamette Falls and use this information towards analysis of the study on efficiency of oxygen supplementation. The majority of juvenile spring chinook salmon released from Willamette hatchery in 1991 begin downstream movement immediately upon liberation. They travel at a rate of 1.25 to 3.5 miles per hour during the first 48 hours post-release. Considerably slower than the water velocities available to them. Juveniles feed actively during migration, primarily on aquatic insects. Na{sup +}/K{sup +} gill ATPase and cortisol are significantly reduced in juveniles reared in the third pass of the Michigan series with triple density and oxygen supplementation, suggesting that these fish were not as well developed as those reared under other treatments. Returning adult spring chinook salmon migrate upstream at an average rate of about 10 to 20 miles per day, but there is considerable between fish variation. Returning adults exhibit a high incidence of wandering in and out of the Willamette River system above and below Willamette Falls.
Date: May 1, 1993
Creator: Snelling, John C.
Partner: UNT Libraries Government Documents Department

Mammary tumors and serum hormones in the bitch treated with medroxyprogesterone acetate or progesterone for four years

Description: After four years of a long term contraceptive steroid safety study, the incidence and the histologic type of mammary dysplasia produced is similar in beagles treated with medroxyprogesterone acetate (medroxyprogesterone) or progesterone. Serum insulin, thyroid stimulating hormone (TSH), triiodothyronine, growth hormone, prolactin, 17..beta..-estradiol, progesterone, and cortisol were determined by radioimmunoassay on samples collected after 45 months of treatment. Serum growth hormone and insulin concentrations were elevated in a dose related manner in both treatment groups. Triiodothyronine, cortisol, and estradiol-17..beta.. (medroxyprogesterone only) were lowered. TSH and prolactin concentrations were not changed. Pituitary--gonadal hormone interaction in the pathogenesis of mammary neoplasia of the dog is discussed. Prolonged treatment of the beagle with massive doses of progesterone or medroxyprogesterone results in a dose related incidence of mammary modules.
Date: January 1, 1978
Creator: Frank, D.W.; Kirton, K.T.; Murchison, T.E.; Quinlan, W.J.; Coleman, M.E.; Gilbertson, T.J. et al.
Partner: UNT Libraries Government Documents Department

Interactive radiopharmaceutical facility between Yale Medical Center and Brookhaven National Laboratory. Progress report, November 1, 1980-October 31, 1981

Description: Research conducted in three principal areas is discussed and summarized. (1) Investigation of the influence of antiarrhythmic agents, such as lidocaine and procainamide, on the chemotaxis and nylon fiber adherence of indium-111-labelled human polymorphonulcear leukocytes (PMNs) in vitro revealed that at normal therapeutic levels of lidocaine and procaine, the adherence and chemotactic function of In-111-PMNs remain unaltered. Results with higher therapeutic blood levels are also discussed. (2) An improved method for labeling human platelets with In-111-oxine is outlined, and the influence of centrifugal force, oxine, ethanol, and radiation on platelet function is reported. Results indicate that normal labeling procedures induce no gross changes in platelet function. (3) The chemical preparation of radioiodinated arachidonic acid (AA) and nonradioactive acid ester of AA, and the analysis of metabolites of these compounds following myocardial ischemia were investigated in dogs. The tissue uptake of /sup 131/I-AA was compared to that of thallium-201.
Date: unknown
Creator: Gottschalk, A.
Partner: UNT Libraries Government Documents Department