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Engagement Of Seniors: 'How' And 'Why' Engagement Profiles Change Over Time, Kelly Carr Jan 2014

Engagement Of Seniors: 'How' And 'Why' Engagement Profiles Change Over Time, Kelly Carr

Electronic Theses and Dissertations

This study explored 'how' and 'why' engagement profiles change throughout older adulthood within a framework of successful aging. A convergent parallel mixed methods design was employed. Fifty-four participants (mean age = 79.17, age range = 65-97 years; 21 males, 33 females) completed questionnaires to quantify 'past' and 'present' engagement. Focus groups segmented by decade of life and semi-structured interviews were completed with a subsample of participants (n = 42). Results indicated that participation in productive and active leisure activities decreased with increasing age, while social and passive leisure engagement remained stable. This change in engagement pattern may be a function of the ...


Effectiveness Of Commercial Video Gaming On Fine Motor Recovery In Chronic Stroke Within Community-Level Rehabilitation, Kathleen C. Paquin Jan 2014

Effectiveness Of Commercial Video Gaming On Fine Motor Recovery In Chronic Stroke Within Community-Level Rehabilitation, Kathleen C. Paquin

Electronic Theses and Dissertations

Introduction: Chronic stroke survivors often live with persisting upper extremity deficits that affect their daily life, and are traditionally offered little rehabilitation. Commercial gaming can act as a motivating way to complete rehabilitation. Purpose: To investigate the effectiveness of commercial gaming as an intervention for fine motor recovery in chronic stroke. Methods: Ten chronic phase post-stroke participants completed a 16-session program using the Nintendo Wii for 15 minutes 2x/week with their more affected hand. Measures used at four testing sessions included: Jebsen Hand Function Test (JHFT), Box and Blocks Test (BBT), Nine Hole Peg Test (NHPT), Stroke Impact Scale ...


Exploring New Capacities For Pitx3 During Xenopus Embryogenesis, Lara Nicole Hooker Jan 2012

Exploring New Capacities For Pitx3 During Xenopus Embryogenesis, Lara Nicole Hooker

Electronic Theses and Dissertations

Pitx3 encodes a homeodomain transcription factor that represents the causative locus for the aphakia phenotype in mouse as well as congenital cataracts and anterior segment mesenchymal dysgenesis in humans. Mutations in Pitx3 can also lead to the development of Parkinson's disease. A conserved role for Pitx3 has been established in the terminal differentiation and maintenance of lens fibres and dopaminergic neurons within the midbrain. Pitx3 has also been reported to contribute to skeletal muscle differentiation in mice. Through the use of morpholino-mediated knockdown, the Xenopus model system has allowed further refining of putative roles for pitx3 during embryogenesis. We ...


Novel Targets And Functions For Xenopus Pitx3 During Embryonic Development, Cristine Smoczer Jan 2012

Novel Targets And Functions For Xenopus Pitx3 During Embryonic Development, Cristine Smoczer

Electronic Theses and Dissertations

Pitx3 is a homeodomain transcription factor with an expression pattern conserved across phyla: in the dopaminergic neurons of the midbrain, in the lens during all stages of lens development and in the forming somites. In Xenopus laevis, this gene shows novel expression areas, such as the pituitary gland, the heart and the gut. Morpholino-based knockdown of pitx3 results in phenotypes characterized by small or absent lens, bent dorsal axis and randomized coiling of the heart and gut. Comparing gene expression changes in wild-type versus knockdown embryos by microarray, we generated a vast list of genes possible downstream targets for pitx3 ...


Role Of Mitogen-Activated Kinases In Cd40-Mediated T Cell Activation Of Monocyte/Macrophage And Vascular Smooth Muscle Cell Cytokine/Chemokine Production, Denise M. Milhorn Aug 1999

Role Of Mitogen-Activated Kinases In Cd40-Mediated T Cell Activation Of Monocyte/Macrophage And Vascular Smooth Muscle Cell Cytokine/Chemokine Production, Denise M. Milhorn

Electronic Theses and Dissertations

This dissertation represents efforts to determine the functional consequences acquired by vascular smooth muscle cells (SMC) in response to CD40 ligation by activated CD154+ T cells, and to elucidate components of the signaling pathway(s) activated in response to CD40 signaling in both monocytes and SMC. To study the consequences of CD40 stimulation, primary human monocytes and aortic SMC were treated with plasma membranes purified from CD154 + , CD4+ T cells. The results presented in this dissertation demonstrate that SMC, like monocytes/macrophages, are capable of interacting with T cells in a manner that results in reciprocal activation events. SMC were ...


Signaling Mechanisms For Muscarinic Receptor-Mediated Coronary Vasoconstriction In Isolated Rat Hearts, Yi Zhang Aug 1999

Signaling Mechanisms For Muscarinic Receptor-Mediated Coronary Vasoconstriction In Isolated Rat Hearts, Yi Zhang

Electronic Theses and Dissertations

The signaling mechanisms for muscarinic receptor-mediated vasoconstriction in coronary resistance arteries were studied in KCl-arrested isolated rat hearts perfused at a constant flow rate. The cholinergic agonists acetylcholine and bethanechol were given by bolus injection or constant infusion. The coronary vascular resistance was monitored by measuring the changes in perfusion pressure. The selective muscarinic agonist bethanechol caused a similar vasoconstrictor response as ACh, but with less potency and efficacy. Bolus injection of bethanechol evoked a phasic vasoconstriction in a dose-dependent manner, while infusion of bethanechol evoked a tonic vasoconstriction without producing tachyphylaxis. Coronary vascular responses to bethanechol were further examined ...


In Vitro Assessment Of The Toxicity Of Cocaine And Its Metabolites In The Human Umbilical Artery, Tessa L. Long Aug 1998

In Vitro Assessment Of The Toxicity Of Cocaine And Its Metabolites In The Human Umbilical Artery, Tessa L. Long

Electronic Theses and Dissertations

An in vitro model was used to assess the effect of cocaine and its metabolites on the umbilical artery. Objectives were to pharmacologically confirm the presence of adrenergic innervation using tyramine, evaluate the ability of cocaine, benzoylecgonine, norcocaine and cocaethylene to potentiate vasoconstriction by serotonin and norepinephrine, examine the ability of ketanserin to block the enhanced vasoconstriction produced by cocaine, and determine displacement of 3 H-ketanserin by serotonin, norepinephrine, tyramine and mianserin. The vasoconstrictive effect of tyramine (100 μM) was enhanced in the presence of cocaine by 257%. Vasoconstrictive effects of serotonin and norepinephrine were significantly enhanced by cocaine by ...


Tnf(Alpha)-Dependent And Tnf(Alpha)-Independent Activation Of Macrophage Effector Function, Annette R. Clemons-Miller May 1998

Tnf(Alpha)-Dependent And Tnf(Alpha)-Independent Activation Of Macrophage Effector Function, Annette R. Clemons-Miller

Electronic Theses and Dissertations

Tumor necrosis factor α (TNFα) is a pleiotropic cytokine that is predominantly produced by activated macrophages. The effects of TNFα are as diverse as the cells with which it interacts, e.g., stimulating fibroblast growth, exerting cytotoxic/cytostatic; activity against various human and murine cell lines, promoting inflammation through upregulation of endothelial adhesion molecules and IL-8 production. Yet TNFα is best known, and in fact was originally described, for its role in the bacterial-induced hemorrhagic necrosis of tumors and exacerbation of septic shock in which aberrant TNFα production leads to vascular collapse, cachexia, multiple organ failure, and ultimately death in ...


Cd40-Mediated Signaling Of Interleukin-1(Beta) Synthesis And Rescue From Apoptosis In Monocytes: Modulation By Il-4 And Il-10, Jonathan C. Poe Dec 1997

Cd40-Mediated Signaling Of Interleukin-1(Beta) Synthesis And Rescue From Apoptosis In Monocytes: Modulation By Il-4 And Il-10, Jonathan C. Poe

Electronic Theses and Dissertations

To date, the cellular mechanisms involved in the progression of diseases characterized by chronic inflammation, such as rheumatoid arthritis (RA), remain largely unknown. However, cell-to-cell contact interactions between CD4+ helper T (Th) cells and monocytes have been implicated in the induction and maintenance of pro-inflammatory cytokine synthesis that is characteristic to the pathogenesis of RA. One such cytokine produced during monocyte-Th cell contact is interleukin (IL)-1 β, a mediator directly involved in the characteristic tissue destruction that occurs in the synovia of individuals with RA. Previous studies in our laboratories have shown that ligation of CD40 on monocytes with ...


Comparison Of Beta-Adrenoceptor Coupled Camp Production In Cultured Human Mononuclear Leukocytes And Myometrial Cells, Yu-Li Liu Dec 1997

Comparison Of Beta-Adrenoceptor Coupled Camp Production In Cultured Human Mononuclear Leukocytes And Myometrial Cells, Yu-Li Liu

Electronic Theses and Dissertations

$\beta\sb2$-Adrenoceptor ($\beta\sb2$-AR) agonists, such as terbutaline, are used as tocolytic agents in the treatment of preterm labor. $\beta$-Adrenoceptor stimulation relaxes myometrium through specific receptors coupled through Gs to adenylyl cyclase (AC) that catalyzes the conversion of ATP to cAMP. The purpose of this study was to compare $\beta$-adrenoceptors and cAMP production in cultured human leukocytes and myometrial cells, and to determine the importance of $\beta$-adrenoceptors and cAMP production in isoproterenol-induced myometrial relaxation. $\sp{125}$I-iodopindolol was used to assess $\beta$-adrenoceptor affinity and number cAMP levels were analyzed before and after stimulation by ...


Moraxella (Branhamella) Catarrhalis: A Molecular Epidemiology Study, Lyndell R. Gill May 1995

Moraxella (Branhamella) Catarrhalis: A Molecular Epidemiology Study, Lyndell R. Gill

Electronic Theses and Dissertations

Moraxella (Branhamella) catarrhalis is the third-most-frequently isolated microorganism associated with acute exacerbations of chronic bronchitis in patients during their stay at the Mountain Home VA Medical Center (MHVAMC). In order to develop a practical, epidemiologically-meaningful typing method for M. (B.) catarrhalis, we tested two methods based on analysis of chromosomal DNA for typeability, reproducibility, and ability to differentiate between unrelated strains (discriminatory power, D). M. (B.) catarrhalis isolants from MHVAMC from 7/1/87-6/30/88 were grown overnight in broth and embedded in agarose. DNA was isolated by standard methods. The DNA was subjected to: (1) restriction endonuclease digestion ...


Persistent Oral Dyskinesias Induced By Long-Term Haloperidol Treatment Is Dissociated From Changes In Neostriatal B(Max) And Mrna Content For Dopamine D(2) Receptors, Nuoyu Huang May 1995

Persistent Oral Dyskinesias Induced By Long-Term Haloperidol Treatment Is Dissociated From Changes In Neostriatal B(Max) And Mrna Content For Dopamine D(2) Receptors, Nuoyu Huang

Electronic Theses and Dissertations

Due to the presumed associations of dopamine (DA) receptor supersensitivity phenomena in both long-term neuroleptic-treated tardive dyskinetic rats and neonatal 6-hydroxydopamine (n6-OHDA)-lesioned rats, we studied the influence of haloperidol on n6-OHDA-lesioned rats. At 3 days after birth rats received 6-OHDA-HBr (200 $\mu$g, bilateral intracerebroventricularly; desipramine pretreatment, 20 mg/kg, 1h) or vehicle. Two months later haloperidol (1.5/kg/day $\times$ 2 days/week for 4 weeks, then 1.5 mg/kg/day, every day for 10 months) was added to the drinking water. Spontaneous oral activity of intact and n6-OHDA-lesioned rats receiving haloperidol was reached and maintained ...


Indomethacin Reduces Splenic Red Pulp Macrophage Populations In Female New Zealand White Rabbits, Thane S. Thurmond May 1995

Indomethacin Reduces Splenic Red Pulp Macrophage Populations In Female New Zealand White Rabbits, Thane S. Thurmond

Electronic Theses and Dissertations

In an effort to elucidate the mechanism by which indomethacin (IN) attenuates the stimulatory effect of estradiol (E$\sb2$) on rabbit splenic red pulp macrophages (RPM), thirty-nine female New Zealand White rabbits were divided into 10 groups: ovariectomized (OVX), OVX/IN at 0.1 and 5.0 mg/kg body weight (bw)/day; sham OVX (SOVX), SOVX/IN at 0.1 and 5.0 mg/kg bw/day; OVX/25 mg E2, OVX/25 mg E$\sb2$/IN at 0.1 and 5.0 mg/kg bw/day; intact Control. Quantitative changes in RPM population in response to the treatments ...


Role Of The Cd40-Cd40 Ligand Interaction In Cd4(+) T Cell Activation Of Monocyte Interleukin-1 Synthesis, David H. Wagner Dec 1994

Role Of The Cd40-Cd40 Ligand Interaction In Cd4(+) T Cell Activation Of Monocyte Interleukin-1 Synthesis, David H. Wagner

Electronic Theses and Dissertations

Most studies of the induction of cytokine synthesis in monocytes have used an exogenous triggering agent such as Lipolpoysaccharide (LPS). However, during nonseptic chronic inflammatory responses (e.g., rheumatoid arthritis) monocyte activation occurs as a result of T cell generated signals. This report demonstrated that plasma membranes from anti-CD3 activated peripheral CD4$\sp{+}$ T cells (Tm$\sp{\rm A}$) but not from resting CD4$\sp{+}$ cells (Tm$\sp{\rm R}$) induced monocytes to synthesize IL-1 in the absence of costimulatory cytokines. The expression kinetics of the molecule(s) unique to activated T cells which interact with monocyte receptors to induce ...


Factors Influencing The Oxidation Of Lipoproteins And Plasma Lipids, Yanshan Ma Dec 1994

Factors Influencing The Oxidation Of Lipoproteins And Plasma Lipids, Yanshan Ma

Electronic Theses and Dissertations

The hypothesis that antioxidant vitamins (ascorbate and tocopherols) along with urate protect blood plasma lipids from oxidation was tested. Dietary fat is also an important factor influencing plasma lipid peroxidation. The purpose of this study was to investigate the role of plasma antioxidants and dietary fat on low density lipoprotein (LDL) and plasma lipid oxidation. In the first part of this study, we compared the ability of urate and ascorbate to protect human LDL from in vitro oxidation. LDL oxidation was initiated by 15 mM of a water soluble azo-initiator in the presence or absence of ascorbate or urate. The ...


Characterization Of The Vasoactivity Of Tachykinins In Isolated Rat Kidney: Functional Studies And In Vitro Receptor Autoradiography, Yuejin Chen May 1994

Characterization Of The Vasoactivity Of Tachykinins In Isolated Rat Kidney: Functional Studies And In Vitro Receptor Autoradiography, Yuejin Chen

Electronic Theses and Dissertations

Although tachykinins have potent vascular actions, their effect on renal resistance blood vessels is currently unknown. The vasoactive properties of tachykinins and related analogs were assessed in isolated perfused rat kidney. At a basal perfusion pressure (PP) of 75 $\pm$ 6 mm Hg (n = 5), bolus injections of substance P (SP) had no significant vasoactive effect. Following a sustained increase in baseline PP (134 $\pm$ 10 mm Hg) produced by phenylephrine (1 $\mu$M), SP evoked a dose-dependent increase in PP. The largest dose of SP increased PP by 60 $\pm$ 5 mm Hg. The vasoconstrictor response to SP was ...


Denervation Supersensitivity Of The Rat Vas Deferens: A Role For Protein Kinase C, Sonny T. Abraham May 1994

Denervation Supersensitivity Of The Rat Vas Deferens: A Role For Protein Kinase C, Sonny T. Abraham

Electronic Theses and Dissertations

A role for protein kinase C (PKC) in the denervation-induced supersensitivity of the rat vas deferens was investigated. Chronic, surgical denervation of the rat vas deferens (up to 8 days) resulted in tissues that produced enhanced contractile responses to norepinephrine (NE) in isolated organ baths. Single challenges of NE (10 $\mu$M) produced 0.6 $\pm$ 0.1 g of maximal tension in the control vas whereas in the paired, denervated tissue 2.2 $\pm$ 0.3 g of tension was recorded (n = 6). Cumulative concentration-effect curves to NE produced in the denervated vas deferens were shifted 18-fold to the ...


Differential Role Of The Endothelium In Regulating Microvascular Blood Flow, Tao Tang May 1994

Differential Role Of The Endothelium In Regulating Microvascular Blood Flow, Tao Tang

Electronic Theses and Dissertations

The vascular endothelial cell (EC) plays an important role in regulating vascular tone and local blood flow by sensing chemical and mechanical stimuli on the vascular wall and releasing a host of vasoactive substances upon activations of endogenous or exogenous vasoactive substances. The central hypothesis is that local control of blood now and autoregulatory behavior in the microcirculation is distinctive at different levels of the vasculature and is dependent on the cellular activities of the EC and its interaction with the local environment. The in vivo as well as the ex vivo, flow-controlled preparations of the hamster cheek pouch were ...


Co-Sensitization Of Dopamine And Serotonin Receptors Occurs In The Absence Of A Change In The Dopamine D1 Receptor Complex After A Neonatal 6-Ohda Lesion, Li Gong Dec 1993

Co-Sensitization Of Dopamine And Serotonin Receptors Occurs In The Absence Of A Change In The Dopamine D1 Receptor Complex After A Neonatal 6-Ohda Lesion, Li Gong

Electronic Theses and Dissertations

To test whether SKF 38393 could ontogenetically sensitize dopamine (DA) D$\sb1$ receptors and whether this sensitization would be associated with biochemical changes, intact and neonatal 6-hydroxydopamine (6-OHDA)-lesioned rats (200 $\mu$g i.c.v.) were treated daily from birth with SKF 38393 (3.0 mg/kg i.p. x 28 days) or its vehicle. In DA D$\sb1$ neonatally sensitized 6-OHDA rats, enhanced locomotor responses were observed with the first SKF 38393 challenge dose (3.0 mg/kg i.p.) at 6 weeks. This response increased further with weekly SKF 38393 treatments. Enhanced stereotyped behaviors were seen in ...


Nitric Oxide Production: A Mechanism For Inhibition Of Chlamydia Trachomatis Replication, Bojun Chen Dec 1993

Nitric Oxide Production: A Mechanism For Inhibition Of Chlamydia Trachomatis Replication, Bojun Chen

Electronic Theses and Dissertations

Chlamydia trachomatis (CT) replicates in macrophages, but is inhibited by IFN-$\gamma$ or LPS. IFN-$\gamma$ and/or LPS induced nitrite production in mouse peritoneal macrophages, macrophage cell lines (RAW264.7 and J774A.1) and McCoy cells. Kinetic studies indicated that peak production occurred 48 hours post-treatment. CT infection itself was insufficient to induce nitrite production, but resulted in enhancement of nitrite production in IFN-$\gamma$-treated cells. Treatment with IFN-$\gamma$ or LPS resulted in significant inhibition of CT replication in these cells. Strong correlation between nitrite production and inhibition of CT replication was observed in RAW264.7 and ...


Mechanisms Of T Cell-Mediated Macrophage Activation: Role Of Antigen Specific And Antigen Nonspecific Cognate Interactions, Xiang Tao Jun 1993

Mechanisms Of T Cell-Mediated Macrophage Activation: Role Of Antigen Specific And Antigen Nonspecific Cognate Interactions, Xiang Tao

Electronic Theses and Dissertations

Macrophages play an important role in host antimicrobial immunity and in non-septic inflammatory reactions. Most studies on macrophage activation have focused on the roles of the T cell-produced cytokine, interferon-$\gamma$ (IFN$\gamma)$ and bacterial product, lipopolysaccharide (LPS). T cell-macrophage interaction is a critical step in initiating both specific and nonspecific immune responses to antigenic stimulation. The current study examines the role of cognate T cell-macrophage interaction in activation of macrophage effector functions and induction of macrophage early activation gene expression. Viable resting T$\sb{\rm H}$2 clone cells can activate IFN$\gamma$-primed macrophages to produce reactive nitrogen ...


Probing Protein-Protein Interactions Among Proteins Of A Nonaggregated Fatty Acid Synthetase From Euglena Gracilis Variety Bacillaris, Sande G. Williams May 1993

Probing Protein-Protein Interactions Among Proteins Of A Nonaggregated Fatty Acid Synthetase From Euglena Gracilis Variety Bacillaris, Sande G. Williams

Electronic Theses and Dissertations

Enoyl-acyl carrier protein (ACP) reductase from chloroplast nonaggregated fatty acid synthetase (FAS) of Euglena gracilis variety bacillaris was purified to a single band on a denaturing polyacrylamide gel. The enzyme was partially characterized with respect to substrate specificity, reduced nucleotide requirement, and the effect of ACP and Ca$\sp{++}$ on enzyme activity. Antibodies against the purified protein were raised in hens and isolated from eggs. ACP was purified from Euglena in yields of about 1mg/100g (wet weight) of cells. Antibodies were raised against the purified protein. ACP antibodies inhibited the Euglena chloroplast FAS using Euglena or E. coli ACP ...


The Effect Of Trimethyltin On The Cholinergic System Of The Rat Hippocampus, Richard L. Cannon Dec 1992

The Effect Of Trimethyltin On The Cholinergic System Of The Rat Hippocampus, Richard L. Cannon

Electronic Theses and Dissertations

Trimethyltin (TMT) is a neurotoxin occurring in the environment. Exposure to (TMT) is known to destroy specific neuronal components of the hippocampus in the rat and to cause clinical symptoms in exposed humans, including mnemonic deficits, that indicate hippocampal involvement. In addition to hippocampal cell loss TMT causes significant increases in cholinergic markers such as acetylcholinesterase (AChE) stain density and choline acetyltransferase (ChAT) activity in the hippocampus of rats. However, despite these observations the effect of TMT on hippocampal cholinergic system has not been investigated in detail. The purpose of the present study was to elucidate more fully the consequences ...


Molecular And Cellular Analysis Of Chlamydia Trachomatis: Persistence And Reactivation, Kimberly R. Tau May 1992

Molecular And Cellular Analysis Of Chlamydia Trachomatis: Persistence And Reactivation, Kimberly R. Tau

Electronic Theses and Dissertations

Chlamydia trachomatis (CT) is the most prevalent sexually-transmitted infection in the United States. It has been suggested that CT infections can become latent. This has not been substantiated. CT persistence was examined at the molecular and cellular level in vitro and in vivo. Penicillin treatment of CT in vitro results in abnormal inclusions and reduced recovery of infectious CT. Penicillin did not inhibit initial stages of infection, but did downregulate CT rRNA levels after 25 hours post-inoculation (p.i.). DNA amplification was employed to differentiate between a resolved infection and a persistent one. Utilizing a primer pair that amplified a ...


Nitrogen Dioxide Reaction With Proteins: Evidence For Peptide Bond Cleavage At Lysine Residues, Darryl B. Hood May 1991

Nitrogen Dioxide Reaction With Proteins: Evidence For Peptide Bond Cleavage At Lysine Residues, Darryl B. Hood

Electronic Theses and Dissertations

Nitrogen dioxide (NO$\sb2$), an air pollutant produced by burning fossil fuels and a component of cigarette smoke, is thought to contribute to the pathogenesis of pulmonary diseases, such as emphysema. To gain information on the mechanism by which NO$\sb2$ damages the lung, in vitro exposures of $\alpha\sb1$-proteinase inhibitor ($\alpha\sb1$-PI), elastin, bovine serum albumin (BSA), human serum albumin (HSA) and synthetic poly-L-lysine were performed. A genetic deficiency of $\alpha\sb1$-PI predisposes humans to emphysema and NO$\sb2$ has been hypothesized to damage $\alpha\sb1$-PI, which would leave proteases such as human neutrophil elastase ...


Dopamine Agonists Modify The Development Of Brain D1 And D2 Receptor Responsiveness, Anwar A. Hamdi May 1990

Dopamine Agonists Modify The Development Of Brain D1 And D2 Receptor Responsiveness, Anwar A. Hamdi

Electronic Theses and Dissertations

Dopamine (DA) agonist-induced behavioral supersensitivity in the adult rat has served as the standard model for certain of the motor and behavioral side effects associated with long-term exposure to DA agonists in humans. The mechanisms relating receptor events with behavior mediation, however, remain unclear. The striatum of rats progresses through a prolonged and varied postnatal developmental period. In order to examine the relative contribution of D1 and D2 receptor-mediated mechanisms to behavioral changes which follow chronic dopamine agonist exposure, developing rats were treated daily from birth with a D1 agonist, SKF 38393 hydrochloride (3.0 mg/kg $\times$ 32d, i ...


Dopamine Agonists Modify The Development Of Brain D1 And D2 Receptor Responsiveness, Anwar A. Hamdi May 1990

Dopamine Agonists Modify The Development Of Brain D1 And D2 Receptor Responsiveness, Anwar A. Hamdi

Electronic Theses and Dissertations

Dopamine (DA) agonist-induced behavioral supersensitivity in the adult rat has served as the standard model for certain of the motor and behavioral side effects associated with long-term exposure to DA agonists in humans. The mechanisms relating receptor events with behavior mediation, however, remain unclear. The striatum of rats progresses through a prolonged and varied postnatal developmental period. In order to examine the relative contribution of D1 and D2 receptor-mediated mechanisms to behavioral changes which follow chronic dopamine agonist exposure, developing rats were treated daily from birth with a D1 agonist, SKF 38393 hydrochloride (3.0 mg/kg $\times$ 32d, i ...


Attenuation Of Antagonist-Induced Impairment Of Dopamine Receptors By L-Prolyl - L-Leucyl-Glycinamide, Mohamad I. Saleh Apr 1988

Attenuation Of Antagonist-Induced Impairment Of Dopamine Receptors By L-Prolyl - L-Leucyl-Glycinamide, Mohamad I. Saleh

Electronic Theses and Dissertations

It has been shown by others that the prenatal treatment of rats with haloperidol, a dopamine D2 receptor antagonist, leads to a permanent reduction in the number of striatal dopamine D2 receptors in adulthood. Conversely, postnatal treatment of lactating dams with haloperidol from birth for 21 days, leads to an increase in the number of striatal dopamine D2 receptors in the litters, when assessed as adults. The present study was undertaken in order to determine whether chronic, long-term postnatal challenge of rat pups per se, with specific dopamine D1 and D2 receptor antagonists, would modify the ontogeny of the respective ...


Lung Paraquat Content And Effects On The Lung Glutathione Antioxidant System, Nadph, And Polyamines Resulting From Intravenous Coinfusion Of Paraquat And Putrescine To Rats, Jacob R. Dunbar May 1987

Lung Paraquat Content And Effects On The Lung Glutathione Antioxidant System, Nadph, And Polyamines Resulting From Intravenous Coinfusion Of Paraquat And Putrescine To Rats, Jacob R. Dunbar

Electronic Theses and Dissertations

Paraquat was administered to male, Sprague-Dawley rats via continous infusion, at dosage rates of 250 (LoPQ) or 500 (HiPQ) nmoles/hr for seven days. The purpose was to characterize the effects of prolonged, low blood levels of the herbicide on selected lung biochemical parameters. The efficacy of putrescine as an inhibitor of pulmonary paraquat accumulation, in vivo, was assessed in these animals by I.V. coinfusion of 2500 or 5000 nmoles putrescine/hr. Dose-dependent levels of both paraquat and putrescine were achieved by 18 hours and were maintained throughout the exposure period. Terminal lung paraquat content was also dose-dependent and ...


Cisplatin Ototoxicity In The Guinea Pig: An Electrophysiological, Morphological, And Biochemical Study, Sarah E. Barron Dec 1985

Cisplatin Ototoxicity In The Guinea Pig: An Electrophysiological, Morphological, And Biochemical Study, Sarah E. Barron

Electronic Theses and Dissertations

The purpose of this study was to determine changes induced by cisplatin on hair cell (HC) morphology, compound action potential (CAP), Preyer reflex (PR), and Na,K-ATPase activity in the cochlear lateral wall. Guinea pigs were treated with either 0.42, 0.83, 1.17, 1.50 mg/kg cisplatin, i.p. or sterile water for 12 consecutive days and tested on day 13. HC condition was visualized with scanning electron microscopy (SEM), CAP was initiated with a 1 volt click, and Na,K-ATPase activity was measured by the method of Fiske and SubbaRow. HC damage was linear with dose ...