UNT Theses and Dissertations - 649 Matching Results

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The Effect of N, N Bis (ethylene)-P (1-adamantyl) Phosphonic Diamide on Rous Sarcoma Virus

Description: The drug, N,N bis (ethylene)-P (1-adamantyl) phosphonic diamide inhibits focus formation of Rous Sarcoma Virus in tissue culture. Transformation of chick cells was inhibited when the drug was added to chick cells prior to infection. The drug did not inhibit the transformation of Normal Rat Kidney Cells infected with RSV, when the cells were grown at non-permissive temperatures and shifted to permissive temperatures upon addition of the drug. Nor did the drug revert cells transformed at permissive temperatures. These studies indicated that the inhibition of RSV is in the early stage of viral growth, possible penetration or uncoating.
Date: March 1988
Creator: McGraw, Thomas L. (Thomas Lee)
Partner: UNT Libraries

Effect of Operant Behavior on the Metabolism of 5-Hydroxytryptamine

Description: The role of operant behavior in the metabolism of brain 5-hydroxytryptamine (5-HT) turnover was investigated. Two and one-half hours following the administration of 150 mg/kg of para-chlorophenylalanine (PCPA), a specific inhibitor of tryptophan hydroxylase, levels of 5-HT were compared in sedentary and performing rats. Whole brain levels of serotonin were reduced in both responding and sedentary animals; however, differences between these groups were not statistically significant. The drug induced decrease in 5-HT levels was accompanied by a significant decrease in session responding. The degree of suppressed responding could be correlated with the level of 5-HT following PCPA, suggesting that the metabolism of serotonin is in part modulated by the rate of responding as maintained by the operant schedule.
Date: August 1979
Creator: Shepard, Paul
Partner: UNT Libraries

The Effect of Post-exercise Ethanol Consumption on the Acute Hormonal Response to Heavy Resistance Exercise in Women

Description: The purpose of this study was to examine the hormonal response to acute ethanol ingestion following a bout of heavy resistance exercise in women. Eight resistance trained women completed two identical acute heavy resistance exercise tasks (AHRET). From 10-20 minutes post-AHRET, participants consumed either a grain ethanol or a placebo beverage. Blood was collected before (PRE) and immediately after the AHRET (IP) and then every 20 minutes for five hours. Blood collected after beverage ingestion was pooled into 3 batches (phases: 20-40 minutes, 60-120 minutes, and 140-300 minutes post-exercise) and analyzed for serum total testosterone (TT), free testosterone (FT), insulin-like growth factor-I (IGF-I), human growth hormone (GH), cortisol (COR), and estradiol (E2) concentrations. Circulating concentrations of TT were significantly greater at P20-40 than at PRE, P60-120, and P140-300. Circulating concentrations of FT were significantly greater at P20-40 than at all other times. Circulating concentrations of GH were significantly greater at IP than at PRE, P60-120, and P140-300. Circulating concentrations of COR were significantly greater at P20-40 than at all other times. Additionally, COR concentrations at P140-300 were significantly lower than at all other times. Circulating concentrations of IGF-1 were significantly greater at P20-40 than at P60-120 and P140-300. Circulating concentrations of E2 were significantly greater at P20-40 than at all other times. In summary, the present study demonstrated an acute modulation of the neuroendocrine milieu following a heavy resistance exercise bout in women. Ethanol ingestion appeared to have no significant effect on the characteristics of acute hormonal augmentation in TT, FT, GH, COR, IGF-1, or E2.
Date: December 2015
Creator: Budnar, Jr., Ronald G.
Partner: UNT Libraries

The Effect of Repeated Antigen Injections on the C' and C'4 Titers in Guinea Pig Serum

Description: In this study the effects of repeated antigen injections on total complement (C') and C'4 of guinea pig serum were investigated to determine if constant antigenic stimulation would show changes in the C' and C'4 titers. Attempts were also made to correlate any changes with variations in antibody titers during the repeated antigen injections.
Date: June 1961
Creator: Teague, Perry Owen
Partner: UNT Libraries

The Effect of Sodium Salicylate on the Ultrastructure of Trypanosoma lewisi

Description: This study examines ultrastructural changes occurring in seven- and fourteen-day populations of Trypanosorfa lewisi when 60 mg sodium salicylate is administered to the host. These changes were related to the host-immune response. Seven-day trypanosomes showed approximately 10 posterior volutin granules. Seven-day trypanosomes whose host had received salicylate exhibited. 30 to 40 volutin granules, and their posterior tip exhibited volutin granules in high numbers sometimes excluding other cellular elements. Fourteen-day trypanosones showed fewer volutin granules than seven-day, salicylate-treated ones. Salicylate treatment caused no additional ultrastructural alterations. Thus the volutin granules are not linked to the reproduction inhibiting antibody (ablast in) but may be involved in the formation of the trypanocidal antibodies.
Date: August 1974
Creator: Beck, Charles F.
Partner: UNT Libraries

The Effectiveness of Hybrid Problem-Based Learning versus Manual-Based Learning in the Microbiology Laboratory

Description: Promising results from the use of problem-based learning (PBL) as a teaching method in medical programs have encouraged many institutions to incorporate PBL into their curricula. This study investigates how applying hybrid-PBL (H-PBL) in a microbiology laboratory impacts students' higher-order thinking as compared to applying a lecture-based pedagogy. The experimental design compared the learning outcomes of two groups of students: the control group and the H-PBL group, for whom PBL cases comprised 30% of the curriculum. Both groups were taught basic skills for the microbiology lab by the same instructor. Using the traditional teaching style for the control group, the instructor offered each student what they needed for their experiments. The H-PBL group practiced experimental design, data analysis, theory proposal, and created research questions by using six study cases that were closely linked to the area of study. The outcome was measured using a pre- and post- assessment consisting of 24 questions that was designed by following Bloom's taxonomy of learning levels. A one-way ANOVA was used to analyze the data. The results showed that for the first three levels of Bloom's taxonomy— knowledge, comprehension, and application—there were no statistically significant differences between the H-PBL and control group gain scores as determined by a one-way ANOVA. For the knowledge level, f (1, 78) = .232, and p = .632; for the comprehension level, f (1, 78) = .004, and p = .951; and for the application level f (1, 78) =. 028, and p =.863. On the other hand, the gain scores for the three higher levels—analysis, evaluation, and creativity—improved for the H-PBL group. The analysis level showed statistically significant differences, with f (1, 78) = 4.012, and p = .049. Also, there were statistically significant differences in students' performance at the evaluation level, with f (1, 78) = 11.495, ...
Date: May 2017
Creator: Alharbi, Najwa
Partner: UNT Libraries

Effector Response of the Aspartate Transcarbamoylase From Wild Type Pseudomonas Putida and a Mutant with 11 Amino Acids Deleted at the N-terminus of PyrB.

Description: Like its enteric counterpart, aspartate transcarbamoylase (ATCase) from Pseudomonas putida is a dodecamer of two different polypeptides. Unlike the enterics, the Pseudomonas ATCase lacks regulatory polypeptides but employs instead inactive dihydroorotases for an active dodecamer. Previous work showed that PyrB contains not only the active site but also the effector binding sites for ATP, UTP and CTP at its N-terminus. In this work, 11 amino acids were deleted from the N-terminus of PyrB and the ATCase with the truncated protein was expressed in E. coli pyrB- and purified. The wild type enzyme was similarly treated. Velocity-substrate plots without effectors gave Michaelis-Menten kinetics in all cases. Deleting 11 amino acids did not affect dodecameric assembly but altered effector responses. When carbamoylphosphate was varied, the mutant enzyme was inhibited by UTP while the wild type enzyme was activated 2-fold. When the aspartate was varied, CTP had no effect on the mutant enzyme but strongly inhibited the wild type enzyme.
Date: May 2002
Creator: AsFour, Hani
Partner: UNT Libraries

The Effects of 3-Deazaguanine on Chick Embryo Fibroblasts and Rat Kidney Cells Infected with Temperature-Sensitive Mutant and Wild-Type Rous Sarcoma Viruses

Description: Chick embryo fibroblasts and rat kidney cells infected in vitro with Rous Sarcoma viruses were treated with 3-deazaguanine (3-DG). The findings revealed that 3-DG inhibited virus-induced cellular transformation. Degree of inhibition is dependent on concentration and frequency of media change. 3-DG at the concentrations tested will not reverse transformed cells to the untransformed state and does not have marked effect on replication of viruses. Upon removal of 3-DG, its effect was shown to be reversible. Cell growth was generally retarded in medium containing 3-DG. When xanthosine and inosine were added to the medium, cell growth was unaffected, but it increased in guanosine.
Date: December 1979
Creator: Fadare, Samuel O.
Partner: UNT Libraries

Effects of Airway Pressure, Hypercapnia, and Hypoxia on Pulmonary Vagal Afferents in the Alligator (Alligator Misssissippiensis)

Description: The American alligator (Alligator mississippiensis) is an aquatic diving reptile with a periodic breathing pattern. Previous work has identified pulmonary stretch receptors (PSR), both rapidly- and slowly-adapting, and intrapulmonary chemoreceptors (IPCs) that modulate breathing patterns in alligators. The purpose of the present study was to identify the effects of prolonged lung inflation and deflation (simulated dives) on PSR and/or IPC firing characteristics in the alligator. The effects of airway pressure, hypercapnia, and hypoxia on dynamic and static responses of pulmonary stretch receptors (PSR) were studied in juvenile alligators (mean mass = 246 g) at 24°C. Receptor activity appeared to be a mixture of slowly-adapting PSRs (SARs) and rapidly-adapting PSRs (RARs) with varying thresholds and degrees of adaptation, but no CO2 sensitivity. Dives were simulated in order to character receptor activity before, during, and after prolonged periods of lung inflation and deflation. Some stretch receptors showed a change in dynamic response, exhibiting inhibition for several breaths after 1 min of lung inflation, but were unaffected by prolonged deflation. For SAR, the post-dive inhibition was inhibited by CO2 and hypoxia alone. These airway stretch receptors may be involved in recovery of breathing patterns and lung volume during pre- and post-diving behavior and apneic periods in diving reptiles. These results suggest that inhibition of PSR firing following prolonged inflation may promote post-dive ventilation in alligators.
Date: December 2013
Creator: Marschand, Rachel E.
Partner: UNT Libraries

Effects of Altitude on Pressure-Flow Relationships in the Vascular Bed of the Hind Limb of the Dog

Description: The purpose of this investigation was to study the effects of decreasing barometric pressure upon the pressure-flow relationships in a peripheral vascular bed in an attempt at better delineation of the autoregulatory mechanisms. A decrease in barometric pressure does influence the transmural pressure and could theoretically affect smooth muscle tone. An evaluation of the extent of the transmural effect is essential to understanding vascular dynamics at altitudes.
Date: August 1966
Creator: Roberts, Donald E.
Partner: UNT Libraries

Effects of an Acute Bout of Near-Maximal Intensity Exercise on the Cardiac Enzymes in Human Sera

Description: The Cardiac Profile, a pattern of serum enzyme changes seen within seventy-two hours after an AMI, is diagnostic aid for detecting occurrence of infarcts. The effects of exercise stress on the Cardiac Profile aid clinicians in avoiding diagnostic errors in patients immediately after exercise. Five male volunteers ran from six to ten miles. Serum enzyme levels were monitored serially three days before and five days after stress. Enzyme activity was determined spectrophotometrically and electrophoretically. Significant increases in total CPK and LDH were seen. An LDH 'one-two flip' occurred eight hours after exercise. No MB-CPK was found following the run.
Date: May 1979
Creator: Goheen, Bernadette A.
Partner: UNT Libraries

Effects of Antigen Injection on Titer of C'3 and C'4 Complement Components of Rat Serum

Description: This work attempts to establish some phenomenon of a rise in titer of C'3 and C'4 due to antigenic stimulation. Normal level of complement is established and compared to other workers as well as against guinea pig levels. Young rats were bled to establish normal levels of complement. The animals were then injected with an antigenic substance and after a period of seven days were bled again to determine the level of complement. Various antigenic and non-antigenic substances were used as well as normal saline injections for control.
Date: August 1957
Creator: Whalen, Paul Lorrance
Partner: UNT Libraries

Effects of Brain Brain Injury on Primary Cilia of Glial Cells and Pericytes

Description: Glial cells maintain homeostasis that is essential to neuronal function. Injury to the nervous system leads to the activation and proliferation of glial cells and pericytes, which helps to wall off the damaged region and restore homeostatic conditions. Sonic hedgehog is a mitogen which is implicated in injury-induced proliferation of glial cells and pericytes. The mitogenic effects of sonic hedgehog require primary cilia, but the few reports on glial or pericyte primary cilia do not agree about their abundance and did not address effects of injury on these cilia. Primary cilia are microtubule-based organelles that arise from the centrosome and are retracted before cells divide. Depending on cell type, proteins concentrated in cilia can transduce several mitotic, chemosensory, or mechanosensory stimuli. The present study investigated effects of stab wound injury on the incidence and length of glial and pericyte primary cilia in the area adjacent to the injury core. Astrocytes, polydendrocytes and pericytes were classified by immunohistochemistry based on cell-type markers. In normal adult mice, Arl13b immunoreactive primary cilia were present in a majority of each cell type examined: astrocytes, 98±2%; polydendrocytes, 87±6%; and pericytes, 79±13% (mean ± SEM). Three days post-injury, cilium incidence decreased by 24% in astrocytes (p< 0.008) and 41% in polydendrocytes (p< 0.002), but there was no significant effect in pericytes. Polydendrocytes labeled with the cell cycle marker Ki67 were less likely to have cilia compared to resting, Ki67- polydendrocytes. Considering post-injury rates of proliferation for astrocytes and polydendrocytes, it appears that resorption of cilia due to cell cycle entry may account for much of the loss of cilia in polydendrocytes but was not sufficient to account for the loss of cilia in astrocytes. Under normal conditions, astrocytes rarely divide, and they maintain non-overlapping territories. However, three days after injury, there was a 7-fold increase in ...
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Date: December 2016
Creator: Coronel, Marco Vinicio
Partner: UNT Libraries

Effects of Carbaryl (1-Naphthyl-n-methylcarbamate) on Trichocorixa Reticulata (Hemiptera: Corixidae) and Glyptotendipes Barbipes (Diptera: Chironomidae)

Description: My study of the effects of carbaryl in aquatic systems under controlled laboratory conditions emphasized four major objectives: (1) to determine the acute toxicity of carbaryl to the herbivorous adult and immature Trichocorixa reticulata (Guerin)(Hemiptera: Corixidae), and to the omnivorous larvae of Glyptotendipes barbipes (Staeger) (Diptera: Chironomidae) under static bioassay; (2) to adapt a quantitative method of analysis for carbaryl in water and whole insect tissue extract; (3) to measure the accumulation of the insecticide by G. barbipes under static exposure; and (4) to quantify the uptake and loss of carbaryl by G. barbipes under daily-renewed sublethal dosages.
Date: December 1971
Creator: Gash, Stephen L.
Partner: UNT Libraries

Effects of CFT Legumine™ Rotenone on Macroinvertebrates in Four Drainages of Montana and New Mexico

Description: Rotenone is considered essential in the restoration of native fish populations; however, the technique is contentious and criticized, specifically concerning impacts to invertebrates. Knowledge of effects to non-target organisms is important for the management and conservation of fish populations. This thesis has two general objectives: (1) demonstrate the influence CFT Legumine™ rotenone has on benthic macroinvertebrates for restoration projects in Montana and New Mexico and (2) evaluate the immediate response by means of invertebrate drift. Chapters 2 and 4 incorporate results from four different restoration projects that examine benthic macroinvertebrate response. Results indicate treatment effects are minimal for Specimen and Cherry Creek projects in Montana. New Mexico projects, Comanche and Costilla Creek suggest a greater influence. Potassium permanganate used to neutralize rotenone, influenced communities in three of the four projects. Regardless, invertebrates in all four projects recovered one-year after treatment. Chapter 3 examines macroinvertebrate drift during rotenone treatment. Results suggest a delayed response compared to previous literature. Rotenone appears to have the greatest immediate influence on the early life stages of Ephemeroptera and Plecoptera. To reduce impacts of rotenone to invertebrates, managers should apply CFT Legumine and use the minimal dosage and duration to complete the projects goal of removing non-indigenous fish species.
Date: August 2011
Creator: Skorupski, Joseph A., Jr.
Partner: UNT Libraries

The Effects of Common Electrolytes on Growth and Development of Selected Species of Aquatic Actinomycetes

Description: The role that aquatic actinomycetes play, in the production of tastes and odors in water supplies has been investigated since 1948. The ability of these organisms to produce by-products in lakes and streams, which renders the water unpalatable, is of considerable public health importance. It is desirable that the waterworks industry has as much information as possible concerning the factors that contribute to the growth of these organisms. Since it appears that the aquatic actinomycetes may be isolated from most fresh-water sources, the problem of diversified environments and nutritional requirements offers an excellent field of investigation. The fresh-waters of the world contain variable quantities of electrolytes that may determine in part the biological activity of these organisms. The unsolved questions in this instance are concerned with the electrolytes present and their quantitative effects on the growth and development of these forms.
Date: August 1959
Creator: Sissom, Stanley L.
Partner: UNT Libraries

Effects of Copper on Immune Responses of Largemouth Bass, Micropterus salmoides

Description: Copper exposures of 400 μg/L for 5,10 and 15 days resulted in no significant differences in antibody titers of largemouth bass, Micropterus salmoides injected with Aeromonas hydrophila compared to control-injected bass. Twenty days of exposure did significantly increase titers. The control group had significantly lower antibody titers than either control-injected or copper-exposed.
Date: August 1994
Creator: Connell, Patrice M. (Patrice Michelle)
Partner: UNT Libraries

Effects of Daily Oral Injections of Quercetin on Implanted Colon-25 Tumor Growth in Balb-C Mice

Description: The effects of three oral dosages (0.4 mg, 0.8 mg, and 1.6 mg) of quercetin on Colon-25 tumors implanted in Balb-c mice were studied. The data in this study show that: (1) certain dosages of quercetin in alcohol solutions, reduces the weight, and size of implanted Colon-25 tumors in Balb-c mice, (2) these same dosages of quercetin all produce a profound neutrophilia combined with a significant lymphopenia at day 20 post-implantation, and (3) there was relatively little evidence of histological changes in the quercetin-treated tumor section which would indicate that the action(s) of quercetin is primarily at the subcellular level probably within the nuclei of the tumor cells.
Date: May 2000
Creator: Hayashi, Adam
Partner: UNT Libraries

Effects of Exogenous Steroids on the Adrenal Plasma Membrane Alteration of Steroidogenesis and Cell Morphology

Description: Using cultured Y-1 mouse adrenal tumor cells which produce the steroid 20(-hydroxypregn-4-en-3-one (20-DHP), it was found that 10-5 M corticosterone and deoxycorticosterone increased basal and inhibited ACTH-induced 20-DHP production. The steroid effects were concentration-dependent, reversible, and specific since six other steroids did not stimulate steroidogenesis and varied in their ability to inhibit ACTH-induced steroidogenesis. Cytochalasin D inhibited steroid-stimulated 20-DHP production, suggesting a mechanism of steroid stimulation similar to that of ACTH. Steroidogenesis stimulated by cholera toxin, (Bu) 2 cAMP, or pregnenolone was not inhibited by exogenous steroid; corticosterone increased basal and inhibited ACTH-induced intracellular cAMP production. Steroids altered cell surface morphology. These findings suggest that steroids alter adrenal steroidogenesis by acting within the plasma membrane.
Date: August 1982
Creator: Mattson, Mark Paul
Partner: UNT Libraries

Effects of External Electric Fields on Light Transmittance in Isolated Crayfish Nerves

Description: Acute effects of a pulsed external electric field (PEEF) at 20 V/cm and a d.c. EEF at 90 V/cm on light transmittance in an isolated compound crayfish nerve was measured. In a third series, the nerve was pre-treated with the Na+ channel blocker tetrodotoxin (TTX). A PEEF produced an irreversible increase in the variation of light transmittance in normal nerves but a reversible increase in TTX treated nerves. This data was statistically insignificant. The d.c. EEFs produced a reversible and statistically significant enhancement of variation in light transmittance in both untreated and TTX-treated nerves. The findings may be due to either (1) an alteration in the ion/fluid flux within the nerve or (2) a physical alteration of protein molecules in the membranes.
Date: December 1995
Creator: Northcutt, Brian S. W.
Partner: UNT Libraries

The Effects of Heparin on the Development of Resistance to Antibiotics by Staphylococcus Aureus

Description: Since heparin combines with some antibiotics to decrease the toxicity of the antibiotic to the patient, the purpose of this investigation is to determine whether it has any effect upon the development of resistance to antibiotics by Staphylococcus aureus.
Date: August 1959
Creator: Blanton, William George
Partner: UNT Libraries