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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
751

Structurefunction analysis of the Na,K-ATPase with emphasis on isoform-specific conformational transitions

Segall, Laura January 2003 (has links)
No description available.
752

Firing characteristics of central vestibular neurons in response to angular rotation in the head-restrained rat

Andrei, Ariana R. January 2005 (has links)
No description available.
753

Parturient hormones : cytokine, and oxytocin effects on prostaglandin synthesis

Arslan, Ali January 1997 (has links)
No description available.
754

Interaction of Bacillus spp. and Salmonella enterica Serovar Typhimurium in immune/inflammatory signaling from swine intestinal epithelial cells

Aperce, Celine January 1900 (has links)
Master of Science / Department of Animal Sciences and Industry / J. Ernest Minton / Previous research evaluated a laboratory strain of Bacillus licheniformis (BL) in a model swine epithelium and found it exerted anti-inflammatory effects on Salmonella enterica serovar Typhimurium (S)-induced secretion of interleukin-8 (IL-8). The current investigation evaluated the anti-inflammatory actions of Bacillus bacteria available commercially as feed additives for the swine industry. Three isolates were obtained from the product, two Bacillus subtilis (BS1 and BS3) and one Bacillus licheniformis (BL2). Swine jejunal epithelial IPEC-J2 cells were seeded into wells on permeable membrane supports and allowed to form confluent monolayers. Treatments included apical pretreatment with BL, BS1, BL2, or BS3 for 17 h without S, and the same Bacillus treatments but with 10[superscript]8 CFU S added in the final 1 h of Bacillus incubation. Two additional treatments included negative control wells receiving no bacteria (C) and positive control wells receiving only S. Following bacterial incubation, wells were washed and fresh media containing gentamicin was added. Cells were incubated for an additional 5 h, after which apical and basolateral media were recovered for quantitation of IL-8 and bacitracin. In addition, inserts with epithelial cells that had received S were lysed and lysates cultured to determine treatment effects on S invasion. Exposure to S alone provoked an increase in IL-8 secretion from IPEC-J2 cells compared to C wells (P < 0.001 for both the apical and basolateral directions). Pre-treatment with each Bacillus isolate followed by challenge with S reduced S-induced IL-8 secretion in both apical and basolateral compartments compared to the wells receiving only S (P < 0.001; except for BS3 apical, P < 0.01). Secretion of bacitracin could only be detected in BL2 and BL2+S. Fewer S colonies could be cultured from lysates of BL2+S than S, BS1+S, and BS3+S treatments (P < 0.001). Results suggest that Bacillus subtilis and Bacillus licheniformis have the ability to intervene in secretion of the neutrophil chemoattractant IL-8 from swine intestinal epithelial cells. This effect on chemokine secretion by gastrointestinal epithelial cells in vitro could not be explained solely by production of bacitracin or reduced invasion of epithelial cells by S.
755

Pharmacokinetics of pergolide in normal mares

Wright, Abra M. January 1900 (has links)
Master of Science / Clinical Sciences - Veterinary Medicine / Laurie A. Beard / Objective: To determine the pharmacokinetic properties of oral pergolide in normal mares. Animals: 6 horses, 3-17 years of age, 355-582 kg Procedures: In a randomized, cross over design six healthy adult female horses received pergolide (PO) 0.01mg/kg or placebo after 8 hours of fasting. Samples were taken over a period of 6 day for each portion of the study (treatment or placebo) with a two week minimum wash out period between study periods. Quantification of pergolide concentration was determined by UPLC-MS. Quantification of α-MSH was determined by radioimmunoassay validated for horses. Quantification of ACTH concentration was determined by chemiluminescent enzyme immunoassay. Results: Pergolide was detected in all treated horses. The relatively short time to peak concentration (0.5 hours) indicates a rapid absorption. Mean maximum concentration measured was 4.05 ng/ml + 2.02 with a median time to maximum concentration being 0.415 hours (range:0.33-1.0). The mean half life of pergolide was determined to be 5.86 hours + 3.42. Lower limits of quantitation for the UPLC-MS assay was 0.5 ng/ml. α-MSH results were evaluated using a multiple analysis of variance assay for repeated measures comparing treatment, time, and period. There was a significant treatment to period effect with p=0.02. The effect of period appears to be more significant (p=0.06) compared to the effect of treatment (p=0.77). No effect from pergolide was noted on ACTH concentrations. Conclusions and Clinical Relevance: Horses appear to absorb and eliminate pergolide more rapidly than previously expected. Based on this pharmacokinetic data the dosing strategies of pergolide may need to be altered. However, assay sensitivity does need to be improved prior to recommendations being made.
756

Hormonal regulation of gonadotropin releasing hormone receptor expression in the ewe

Kirkpatrick, Bridgette Lee, 1966- January 1998 (has links)
Endocrine regulation of expression of GnRH receptors is an important step in the control of reproduction. During the early follicular phase of the estrous cycle in the ewe, GnRH receptor expression increases in preparation for the preovulatory surge of LH. The studies described herein were designed to further elucidate the hormonal interactions controlling GnRH receptor expression. In long-term ovariectomized ewes, neither removal of progesterone, nor the presence of estradiol affected the expression of GnRH receptors. However, in ewes ovariectomized during the luteal phase of the estrous cycle and immediately implanted with progesterone and estradiol for 48 hours, low levels of estradiol for 24 hours were required to increase GnRH receptor mRNA following the removal of progesterone. In ovariectomized ewes following hypothalamic-pituitary disconnection, low levels of estradiol and pulsatile GnRH were required to increase GnRH receptor expression within 24 hours of treatment initiation. These results suggest an interaction between estradiol and GnRH is involved in increasing GnRH receptor expression during the periovulatory period. How progesterone, estradiol and, GnRH interact to increase GnRH receptors is unknown, but a possible candidate involved in mediating these interactions may be the cell specific transcription factor, steroidogenic factor-1 (SF-1). SF-1 mRNA increased within 24 hours of treatment of ewes with prostaglandin F₂(α) compared to ewes in the luteal phase of the estrous cycle. This suggests that progesterone may have an inhibitory effect on SF-1 mRNA. SF-1 mRNA was similar between ovariectomized ewes and ovariectomized ewes following hypothalamic-pituitary disconnection treated with estradiol and GnRH. Treatment with estradiol or GnRH alone did not increase SF-1 mRNA. The results of these experiments suggest that progesterone removal as well as the presence of estradiol and GnRH are required to increase GnRH receptor expression during the early follicular phase in the ewe. Further, the transcription factor, SF-1 may be involved in mediating the effects of these hormones on GnRH receptor expression.
757

Substrate specificity of rat liver aldehyde dehydrogenase with chloroacetaldehydes

Sharpe, Amy-Joan Lorna, 1965- January 1991 (has links)
Chlorinated acetaldehydes have recently been the focus of research due to their role as reactive intermediates and their possible occurrence in chlorinated drinking water. The metabolism of these compounds, however, has not been extensively studied. In this study, the in vitro substrate specificity of cytosolic and mitochondrial rat liver aldehyde dehydrogenase toward these compounds was investigated. Both crude and semi-purified preparations of the enzymes were used. Monochloroacetaldehyde was found to be extensively metabolized by this enzyme system. It was metabolized to a greater extent than the standard compound propionaldehyde. Dichloroacetaldehyde was also found to be metabolized by this enzyme, but to a lesser extent than its monochloro-analogue. There was some evidence to suggest, however, that alcohol dehydrogenase and chloral hydrate dehydrogenase may play a significant role in the metabolism of this compound. Chloral hydrate was not metabolized by this enzyme to an appreciable extent.
758

The relationship between axial and appendicular bone mineral density and lifetime leisure physical activity in healthy white males and females, ages 35-85 years

Lyons, Mary Regina, 1964- January 1992 (has links)
This study compared bone mineral density of the radius, ulna, spine, and femur in healthy adults of varying activity levels. The sample included caucasian males (67) and females (82) ranging from 35 to 85 years. Males who were highly active in weight bearing activity had greater bone mineral density of the radius, ulna, femur neck and Ward's triangle of femur than those who were less active. Females who were highly active in high impact weight bearing activity and nonweight bearing activity had greater bone mineral density at the radius than females who were less active in these activities. Multiple regression revealed that weight bearing activity and age were fairly good predictors of radial bone mineral density in males aged 35-64 years, and high impact weight bearing activity and age were fairly good predictors of radial bone mineral density in females aged 35-49 years.
759

Comparative distribution of leucokinin and functionally related peptides in the nervous system of several insects

Chen, Yuetian, 1961- January 1993 (has links)
Antisera against leucokinin IV were used to test for the presence of leucokinin-like peptides in the central nervous systems of Nauphoeta cinerea, Acheta domesticus, Schistocerca americana, Aedes aegypti, Manduca sexta and Apis mellifera. Leucokinin immunoreactive neurosecretory cells were found in the pars intercerebralis and pars lateralis of the brains of N. cinerea, A. domesticus, A. aegypti, but not in the brains of S. americana, M. sexta and A. mellifera. The neurohemal release sites were also very different among species. In contrast, the distribution patterns of leucokinin immunoreactive neurosecretory cells were very similar among abdominal ganglia of all six species. The identity of the leucokinin immunoreactive material in the brain, corpora cardiaca and abdominal ganglia of N. cinerea was shown by HPLC combined with ELISA. In N. cinerea and A. domesticus, leucokinin and vasopressin were found to co-localize in the same neurosecretory cells. In M. sexta, leucokinin and diuretic hormone co-localized in the same neurosecretory cells in abdominal ganglia, but not in the brain.
760

Recording active basilar membrane tuning characteristics using distortion-product otoacoustic emissions

Lizerbram, Jeffrey Kane, 1969- January 1993 (has links)
The objective of this study was to describe ways in which properties of human cochlear travelling waves may be manifested in characteristics of distortion-product otoacoustic emissions (DPOAEs). Four young adults served as subjects. DPOAE magnitude was studied for various frequency-ratio and intensity relationships of the primary stimuli. Results revealed complex relationships between stimulus level (L) and frequency ratios (f). The optimal f2/f1 ratios were highly dependent upon differences between L1 and L2. Maximum distortion product amplitudes were encountered when L2 was smaller than L1 for several stimulus conditions and when f2/f1 ratios were approximately 1.20 (range = 1.05 to 1.25). These observations replicate and extend the findings of prior investigations regarding the optimal parameters associated with the production of DPOAEs, and also provide evidence of the complex, nonlinear events leading to the creation of DPOAEs.

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