Thesis (Ph.D.). / Written for the Dept. of Pharmacology and Therapeutics. Title from title page of PDF (viewed 2009/06/05). Includes bibliographical references.

Thesis (Ph.D.)--Virginia Commonwealth University, 2009. / Prepared for: Dept. of Pharmacology and Toxicology. Title from resource description page. Includes bibliographical references.

Thesis (Ph.D.)--Uniformed Services University of the Health Sciences, 2006 / Typescript (photocopy)

Thesis (M.S.)--Uniformed Services University of the Health Sciences, 2006 / Typescript (photocopy)

The purpose of this study was to examine the effects of cortical spreading depression on neuronal activity in the rat motor (M1) cortex. It is known that cortical spreading depression causes widespread neuronal and glial activity in the cortex, but the degree to which it exerts its effects is unclear. Cortical spreading depression was induced in eight Sprague-Dawley male rats. After two hours, animals were euthanized and immunohistochemistry was performed on the brain to stain for the presence of c-Fos, an immediate early gene that is a well-known marker of neuronal activity. Sections were counterstained for Nissl substance to reveal two populations of cells: Nissl-stained neurons that were c-Fos positive, activated cells and Nissl-stained neurons that were c-Fos negative, non-activated cells. Three sections for each animal were examined and 20-30% of the total M1 cortex was analyzed. Cells were counted using systematic random sampling for each of the six cortical layers. Our results show that the cortical spreading depression did not produce an activation of all neurons. When layers were individually examined, there was a main effect of layer on neuronal activation. This confirmed previous findings that cortical spreading depression had the strongest effect on superficial layers of the cortex

This study investigated nicotine place conditioning in early postweanling and adolescent male and female rats neonatally treated with quinpirole, a dopamine D(2)/D(3) agonist. Previous research has shown that neonatal quinpirole treatment results in an increase of dopamine D(2)-like receptor sensitivity that persists throughout the animal's lifetime, relevant to psychosis. Rats were neonatally treated with quinpirole or saline from postnatal day (P)1-21, and animals were conditioned with nicotine or saline daily from P23-30 as early postweanlings or P32-39 as adolescents in a two- or three-chambered place conditioning apparatus. A drug free test was given on P31 for early postweanlings, and P40 for adolescents. Results on the two chamber apparatus revealed that nicotine increased time spent in the drug-paired context at both ages tested. Neonatal quinpirole treatment resulted in less time spent in the drug-paired context in early postweanling males and increased time spent in the drug-paired context in adolescent females conditioned with nicotine. Adolescent females neonatally treated with saline and conditioned with nicotine on the two chamber apparatus did not differ from controls. On the three-chambered apparatus, nicotine increased time spent in the drug-paired context in both ages tested, which was blocked by neonatal quinpirole in early postweanling males, but enhanced by neonatal quinpirole treatment in adolescents. These results demonstrate both age and sex differences in the effects of nicotine and point to significant differences in performance depending on the apparatus used. Additionally, neonatal quinpirole enhanced the effects of nicotine, but this is true only in adolescents and task-dependent.

No description available.

Ultrasound measurement of change in kidney volume is a sensitive indicator of severity of renal parenchymal injury. Am J Physiol Renal Physiol 319: F447–F457, 2020. First published July 20, 2020; doi:10.1152/ajprenal.00221.2020.—Noninvasive determination of the severity of parenchymal injury in acute kidney injury remains challenging. Edema is an early pathological process following injury, which may correlate with changes in kidney volume. The goal of the present study was to test the hypothesis that “increases in kidney volume measured in vivo using ultrasound correlate with the degree of renal parenchymal injury.” Ischemia-reperfusion (IR) of varying length was used to produce graded tissue injury. We first determined 1) whether regional kidney volume in rats varied with the severity (0, 15, 30, and 45 min) of warm bilateral IR and 2) whether this correlated with tubular injury score. We then determined whether these changes could be measured in vivo using three-dimensional ultrasound. Finally, we evaluated cumulative changes in kidney volume up to 14 days post-IR in rats to determine whether changes in renal volume were predictive of latent tubular injury following recovery of filtration. Experiments concluded that noninvasive ultrasound measurements of change in kidney volume over 2 wk are predictive of tubular injury following IR even in animals in which plasma creatinine was not elevated. We conclude that ultrasound measurements of volume are a sensitive, noninvasive marker of tissue injury in rats and that the use of three-dimensional ultrasound measurements may provide useful information regarding the timing, severity, and recovery from renal tissue injury in experimental studies.

Human milk contains ~ 25 µg/mL of soluble cluster of differentiation 14 (sCD14) protein, a pattern recognition receptor (PRR) that triggers the innate immune system to respond to bacterial lipopolysaccharide (LPS). To date, the role of CD14 in the digestive tract of breast fed infants has not been well characterized and is the subject of this thesis. To investigate the biodistribution of proteins such as CD14 in vivo, a novel method for 14C radiolabeling of proteins to high specific radioactivity was developed using in vacuo methylation. Bovine serum albumin (BSA) and casein were used as test proteins to determine the following: 1) The efficacy of the in vacuo radiolabeling procedure; 2) The extent of incorporation of the 14C-label into the organs of oro-gastric gavaged 10 day old Sprague Dawley rats. [14C]BSA, [14C]casein and [14C]CD14 were prepared with specific radioactivities of 10 400, 10 800 and 163 000 dpm/µg, respectively. After feeding 6.25 µg of 14C-labeled proteins, quantifiable levels of 14C were found in the stomach, jejunum, duodenum, ileum, large intestine, intestinal luminal flushes, blood, liver, spleen and kidneys of rats. The accumulation of radiolabel in the organs of [14C]CD14 fed rats was temporally and spatially distinct from [14C]BSA and [14C]casein. Most notably, the label persisted in the stomach 480 min post-gavage. To design a neonate animal model for biodistribution, the segmental and total gastrointestinal transit times (GItt) were measured in two litters of 10 and 15 day old Sprague Dawley rat pups using barium sulfate. Ten day old rat pups that remained with and without the dam had a total gastrointestinal transit time of 13.8 ± 0.9 hr and 9.3 ± 0.7 hr, respectively. This decrease (p<0.05) in total gastrointestinal transit time in the absence of the dam was age dependent, as it was not observed (p>0.05) in the 15 day old rat pup litter. The immunological impact of an exogenous sCD14 source was examined in human peripheral blood mononuclear cells (PBMC). Pre-treatment of CD14+ monocytes with sCD14 had a protective effect, one of reducing the production of proinflammatory cytokines (TNF-α, IL-6, IL-8, IL-1β) when challenged with LPS. 14C was absorbed by neonate rats upon ingestion of [14C]CD14 and exposure to relatively high concentrations of rCD14 led to a reduction in inflammation. This may be beneficial to initial gut colonization in breast-fed newborns. / Alexander Graham Bell NSERC CGS M scholarship. Japan Society for the Promotion of Sciences, Summer in Japan Fellowship. Funded by the Canadian Institutes of Health Research, Institute of Nutrition Metabolism and Diabetes Grant #82816 “Fate and function of breast milk and recombinant human CD14 at mammary and newborn gastrointestinal mucosal epithelia”.

No description available.