UNT Libraries - 12 Matching Results

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The Fate of Benzo(a)pyrene in Tissues of Mice Exposed to Diesel Exhaust

Description: Mice were exposed to diesel exhaust for 9 months prior to evaluation for benzo(a)pyrene disposition. On the last day of exposure the mice were instilled intratracheally with tritiated-benzo(a)pyrene ([3H]BP). The mice were sacrificed at intervals of 2, 24, and 168 hours. Disappearance of radioactivity from lungs and liver was rapid and essentially linear with time. In lungs, liver, and testes; [3H]BP metabolites were found mainly as conjugates, a form readily excretable. Clearance of the hydroc… more
Date: August 1981
Creator: Loudin, Agnes D.
Item Type: Refine your search to only Thesis or Dissertation
open access

Changes in Body Composition, Plasma Alanine, and Urinary Nitrogen in Rats Subjected to Negative Caloric Balance Through Diet, Diet/Exercise, and Exercise

Description: Male Fischer rats (n=43) were used in a diet-diet/ exercise design to investigate the apparent protein sparing effects of exercise. The animals were divided into five groups: INITIAL (baseline), SEDENTARY (control), DIET, DIET/EXERCISE, and EXERCISE. Carcasses were analyzed for body composition, the blood for plasma alanine concentration and the urine for urea nitrogen concentration. The results showed no significant differences between groups in urinary urea nitrogen, plasma alanine, body weig… more
Date: August 1982
Creator: Ayres, John J. (John Jay)
Item Type: Refine your search to only Thesis or Dissertation
open access

Fluoride-Induced Changes in In Vivo Papillary Cyclic AMP

Description: Two separate experiments were designed to measure urinary cyclic AMP and renal papillary cyclic AMP, respectively, Results suggest that urinary cyclic AMP excretion rate is unchanged and cannot be used as an index of tubular sensitivity to either vasopressin or fluoride. However, renal papillary tissue cyclic AMP increased significantly (p<0.05) at plasma fluoride concentrations which result in polyuric renal failure. Further, it appears that fluoride independently stimulates cyclic AMP in the … more
Date: December 1982
Creator: Maxwell, Jack Allen
Item Type: Refine your search to only Thesis or Dissertation
open access

Mast Cells in the Brains of Mice of Different Genotypes: A Histological Study

Description: Histamine is present in the central nervous system and is believed to be derived from neurons (50 percent) and mast cells (50 percent). This experiment was designed to analyze histologically the numbers and distribution of brain-associated mast cells in normal (+/+), mast cell deficient (W/W^v) and heterozygote (W/+, W^v/+) mice of the WBB6F_1 /J strain. Significant variations in the number and distribution of mast cells between the various genotypes were found. Based on the results, a hypothes… more
Date: May 1983
Creator: Dolce, Angela Kay
Item Type: Refine your search to only Thesis or Dissertation
open access

A Model for Determining Induced Physiological Stress During Respirator Wear

Description: A model was developed to predict the increased physiological effort of wearing a respiratory protective device. Specifically, the model was designed to predict the effects of varying ventilatory demands on eleven respiratory variables of the man-respirator system, breath frequency (f_b), tidal volume (V_t), inspiratory flow (dvi/dt), expiratory flow (dve/dt), inspiratory mask pressure (P_mi), expiratory mask pressure (P_me), inspiratory intrathoracic pressure (P_ii), expiratory intrathoracic pr… more
Date: December 1984
Creator: Meyer, Steve D. (Steve Douglas)
Item Type: Refine your search to only Thesis or Dissertation
open access

Discriminative Stimulus Properties of Cocaine: Tolerance and Cross-Tolerance Characteristics

Description: Rats were trained to discriminate an injection of cocaine, 5.0 mg/kg, from an injection of saline, using a two-lever choice paradigm: one lever was correct after cocaine injection, the other lever was correct after a saline injection. After training, cocaine and methamphetamine were generalized to the cocaine lever, but phenethylamine (PEA) was only partially generalized. Cocaine was injected every 8 hrs, 20.0 mg/kg, and the discriminability of 5.0 mg/kg was tested every other day. Redetermina… more
Date: May 1985
Creator: Wood, Douglas M. (Douglas Michael)
Item Type: Refine your search to only Thesis or Dissertation
open access

Exoprotease Production by Aeromonas hydrophila in a Chemically Defined Medium

Description: Wretlind, Heden, and Wadstrom found ammonium sulfate to be inhibitory for the formation of extracellular protease in Aeromonas hydrophila grown in Brain Heart Infusion medium. They demonstrated by manipulating the iron and zinc content within their medium that it is possible to differentially affect the accumulation of hemolysin and protease by A. hydrophila grown in batch culture. Further manipulation of the composition of this medium was done in the present study to determine the effect of ot… more
Date: May 1985
Creator: Anderson, Paulette S. (Paulette Sue), 1952-
Item Type: Refine your search to only Thesis or Dissertation
open access

The Relationship of Dose to Plasma Concentration with Acute Ingestion of Amitriptyline

Description: The high concentrations of amitriptyline found in blood at autopsy, indicating a large amount of ingested drug, is often contradictory to the prescription available. Using dogs as the animal model it was found that there was a large variance between the dose given and its plasma amitriptyline concentration during the acute phase of absorption. Factors that were found to be important were the amitriptyline to nortriptyline (as metabolite) ratio, the nature of the specimen, and the collection sit… more
Date: May 1985
Creator: Williams, Teresa Lynn
Item Type: Refine your search to only Thesis or Dissertation
open access

An Investigation of the Ratio of Free to Bound Phenytoin in Overdose Cases

Description: An investigation of the ratio of free to bound phenytoin in overdose cases was accomplished by three studies to answer these questions: 1. Will the free to bound ratio change with increasing total phenytoin concentration? 2. Will the free to bound ratio be altered with decreasing total protein concentration? 3. Do these results correlate with overdose cases? The results demonstrated that the ratio of free to bound phenytoin remains constant throughout the therapeutic range as long as a person h… more
Date: August 1985
Creator: Beckman Royder, Mona Lee
Item Type: Refine your search to only Thesis or Dissertation
open access

Muscarinic Receptor Modulation of the Phospholipid Effect in Cardiac Myocytes

Description: The muscarinic agonist carbachol stimulates a rapid increase in ^32Pi incorporation into phosphatidic acid (PA) and phosphatidylinositol (PI) in calcium tolerant myocytes prepared from heart tissue. The density of muscarinic receptors, determined by [^3H]-QNB binding, is greater in the atria than in the ventricles. 250 uM carbachol decreased specific [^3H]-QNB binding to muscarinic receptors on myocyte membranes by fifty percent. Trifluoperazine, also a phospholipase C inhibitor, inhibited the … more
Date: May 1986
Creator: Mattern, Janet
Item Type: Refine your search to only Thesis or Dissertation
open access

Existence of an Alpha One-Adrenoceptor-Mediated Coronary Vasoconstrictor Reflex During Acute Systemic Hypoxia, in Anesthetized, Open-Chest Dogs

Description: The presence of an alpha-adrenoceptor--mediated coronary vasoconstrictor reflex during acute systemic hypoxia was examined in thirteen chloralose-anesthetized dogs. Local vasodilator effects were avoided by perfusing the left common coronary artery (LCC) with normoxic blood, while the dogs were ventilated with 5% 02-95% N2 . Left ventricular afterload was held constant and positive cardiac inotropic responses and beta two-adrenoceptor-mediated coronary vasodilation were blocked by propranolol. … more
Date: December 1987
Creator: Grice, Derald Preston
Item Type: Refine your search to only Thesis or Dissertation
open access

Echocardiographic Assessment of the Left Ventricle in the Spinal Cord Injured Patient

Description: Ten caucasian male quadriplegics were compared with eight sedentary caucasian male controls in regards to left ventricular dimensions and mass obtained from echocardiograrns. The interventricular septum (IVS), left ventricular posterior wall (LVPW) and left ventricular internal diameter (LVII) were within normal limits for both groups. However, the INS in the SCI were significantly thicker than controls (p <0.05). Myocardial thickness was larger in SCI subjects (p <0.05). Absolute left ventricu… more
Date: May 1989
Creator: Nock, Bonnie J. (Bonnie Jean)
Item Type: Refine your search to only Thesis or Dissertation
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