Physiology Commons^™

Interaction Of Acth And Estradiol In The Regulation Of Growth, Differentiation, And Steroidogenic Maturation Of The Baboon Fetal Adrenal Gland, Maria Gomez Leavitt

Theses and Dissertations in Biomedical Sciences

The present study determined whether the growth of, as well as ACTH receptor and P-450 enzyme messenger ribonucleic acid and/or protein levels in the baboon fetal adrenal are dependent upon fetal pituitary ACTH during mid and late gestation and the mechanism by which placental estrogen modulates ACTH actions. Administration of betamethasone (3mg/day) to baboon mothers on days 60-99 of gestation and to the fetus (0.6 mg/, n = 4) or to the fetus (0.6mg) and mother (6 mg/ml; n = 4) every other day between days 150-164 of gestation (term = 184 days) decreased (P $53β-hydroxysteroid dehydrogenase-isomerase (3β-HSD(+)ctochrome P450 17α-hydroxylase, …

Endothelial Nitric Oxide Synthase And Growth Factor Regulation Of Flow-Mediated Vascular Remodeling, David Anthony Tulis

Theses and Dissertations in Biomedical Sciences

This study was designed to characterize structural remodeling of male Wistar rat mesenteric arteries exposed to elevated blood flow in vivo for 1, 3, or 7 days. A series of arterial ligations induced blood flow increases in ileal and second-order branch arteries compared to same animal control vessels. Neither mean carotid nor local mesenteric arterial pressures changed significantly pre- to post-ligation. The primary flow-mediated force in both vessels was shear stress with possible involvement of acute stretch-induced wall stress in the ileal artery. Significant luminal expansion and medial wall hypertrophy occurred in the ileal and second-order arteries in a time-dependent …

Changes In Spinal Height Supine And Walking In Subjects With And Without Lower Back Pain, Dave Gregory

Rehabilitation Sciences Theses & Dissertations

Purpose: The purpose of this study was to develop and test a device that could be used in clinical situations to measure spinal height in subjects with lower back pain.

Introduction: Spinal height measurement provides information on the impact of spinal loading on the intervertebral disc. The stadiometer is presently the most accurate device for this purpose but users of the device must be trained to be measured. This excludes untrainable subjects such as those with lower back pain. For this study, a new ins1rument was developed combining aspects of the stadiometer and other devices to produce a simpler method …

Differential Endometrial Responses Of Primates Vs Rodents: Screening For Antiproliferative Effects Of Antiprogestins, David Williams Burleigh

Theses and Dissertations in Biomedical Sciences

The antiprogestin, mifepristone, has previously been shown to noncompetitively inhibit estrogen-induced endometrial proliferation in nonhuman primates (van Uem et al., 1989; Wolf et al., 1989b; Neulen et al., 1990; Neulen et al., 1996). For both economical and ethical reasons, we are encouraged to identify comparative laboratory rodent models which can substitute the need to use primate models. In the following study, we compared capabilities of the rat uterine weight bioassay versus a primate uterine bioassay, to identify the noncompetitive antiestrogenic/antiproliferative effects of mifepristone.

Long-term ovariectomized monkeys were exposed to exogenous 17β-estradiol (E2) and mifepristone in doses and regimes already demonstrated …

Arterial Wall Hypertrophy And Pdgf-A Expression In One-Kidney, One-Clip Hypertension And Angiotensin Ii Infusion Are Mediated By Elevated Arterial Pressure, Sheri Blair Parker

Theses and Dissertations in Biomedical Sciences

These studies were designed to characterize the relative roles of angiotensin II (ANG II) and pressure in the structural alterations that occur in experimental hypertension. Two separate studies were performed in order to differentiate these two mechanisms. First, male Wistar rats were subjected to one-kidney, one-clip (1K1C) hypertension or sham operation. Losartan, an AT1 receptor antagonist, was administered chronically to half of each surgical group beginning one day before the operation and continued until the end of the study. In a second experiment, rats were implanted with osmopumps delivering either ANG II or saline. To maintain pressure in the normotensive …

Choline Acetyltransferase And Carnitine Acetyltransferase Activity In Human Spermatozoa During Capacitation, Lisa A. Eccles

Theses and Dissertations in Biomedical Sciences

The regional distribution of ChAT activity in human spermatozoa is altered during in vitro capacitation and it correlates with the fertilizing potential of sperm.

Regional immunoreactivity in human spermatozoa as assessed by fluorescent immunocytochemistry was compared with ChAT and CaAT activity determined by enzymatic methodologies. Increasing proportions of sperm exhibited ChAT immunoreactivity along the equatorial region with a concomitant decrease in ChAT reactivity in the midpiece. Also, competitive studies with unlabeled ChAT blocked the equatorial region labeling; the unlabeled CaAT blocked staining along the midpiece region of the tail, suggesting some cross-reactivity of the ChAT antiserum with the CaAT enzyme. …

The Relationship Of Foot Types To Pressure Distribution Patterns Of The Forefoot During Gait, Hui-Ji Fan

Rehabilitation Sciences Theses & Dissertations

Pressure distribution under the foot has been considered a useful indicator in the treatment of foot problems. The purpose of this study was to determine the relationship between foot types and pressure patterns under the forefoot. Fifty-four healthy subjects (19 males, 35 females, mean age=27 years, S0=4, range=21-39) participated in this study. A BTE pedobarograph was used to record pressure distribution under the foot during barefoot walking. Foot types were classified as neutral, pronated, and supinated. Pressure distribution under the forefoot was classified as medial, central, and lateral patterns. The medial pattern had the highest peak pressure under the first …

The Assessment Of Osteoinductivity Of Human Allograft Demineralized Bone Matrix By In Vivo And In Vitro Assay Models, Min Zhang

Theses and Dissertations in Biomedical Sciences

The osteoinductive potential (osteoinductivity) is a very important aspect of demineralized bone matrix (DBM) as a biomaterial. This study is directed at establishing qualitative and quantitative assays of the osteoinductivity of human DBM. Further aspects of this study include an assessment of the effects of the production process, matrix characterization, and donor related factors on osteoinductivity of the DBM.

Athymic mice were chosen as the animal model for use in the in vivo bioassay. Implantation of DBM in muscle pouches provided for much higher osteoinductivity (remineralization to 10% calcium) than subcutaneous site implantation (remineralization to 1.6% calcium). Histological observations revealed …

A Kinetic Investigation Of The Mechanism Of Muscle Contraction With A Series Of Nucleotides, Wei Jiang

Theses and Dissertations in Biomedical Sciences

Muscle contraction is thought to be accomplished by sliding of myosin filaments along actin filaments. Although actomyosin naturally uses ATP as an energy source, it can also use other nucleoside triphosphates (NTP) as substrates. In this work, the dependence of rate and equilibrium constants of the various steps in the muscle contraction mechanism upon nucleotide structure was investigated to unravel the dependence of the mechanical properties of the muscle upon changes in different biochemical steps of the mechanism.

The experiments measuring the dissociation of actomyosin by NTP (or mant-NTP) shows that both the rate constant of actomyosin-S1 dissociation and second …

Cellular Mechanisms Underlying Myogenic Reactivity In Isolated Arterioles, Hui Zou

Theses and Dissertations in Biomedical Sciences

The myogenic reactivity provides one of the principal mechanisms for blood flow autoregulation. The aims of the performed studies described in this dissertation were to test the role of [Ca²⁺]_i and MLC phosphorylation in arteriolar myogenic reactivity and further examine the source(s) of activator Ca²⁺ required to initiate and maintain myogenic vasoconstriction. In addition, the possible underlying mechanism of contractile protein expression was also addressed.

These studies used male Sprague Dawley rats of 200 ~ 350 grams body weight. Experiments were carried out using rat cremaster first order arterioles and mesenteric vessels. Gel electrophoresis and immunoblotting …

Cardiovascular, Thermoregulatory, Metabolic And Performance Responses To Repeated Ultraendurance Cycling, Bart E. Drinkard

Human Movement Studies & Special Education Theses & Dissertations

The purpose of this study was to describe physiological and performance responses in six highly trained cyclists during four days of repeated ultraendurance cycling. Each subject raced in four consecutive 100 mile per day time trials using their own bicycles mounted to a computerized ergometer. The race course profile consisted of rolling terrain with simulated gradients of minus five to ten percent. Body weight was measured prior to each time trial. Total performance time and fluid intake for each time trial were recorded. All other data were measured at ten mile intervals during each 100 mile time trial. Means for …

A Comparison Of Three Cam Profiles As Measured By Emg And Angular Displacement, Elizabeth Grace Ann Hood

Human Movement Studies & Special Education Theses & Dissertations

The purpose of this study was to determine if variations in cam profiles cause differences in muscle contraction as measured by surface EMG, knee joint angular displacement, and torque. There were seven hypotheses tested. The ten subjects were adult male volunteers (18-24 years) who participated in a counterbalanced treatment design study testing three variously shaped cams over five lifting tests. The results indicated that for the EMG data, the cam and lifts effect had significant Wilk's values. For the cam effect the consistent cam had the highest millivolt value. For the lift effect, the pre 1 rep max had the …

Microzooplankton In The Lower Chesapeake Bay, And The Tidal Elizabeth, James, And York Rivers, Gyung-Soo Park, Harold G. Marshall

Biological Sciences Faculty Publications

Results of a one year study in the lower Chesapeake Bay and three tidal rivers indicate an abundant microzooplankton population, with a mean concentration of 4,231.1/Liter. The most abundant components are the non-loricate ciliates (2,518.2L, 59.5% of the annual total) and tintinnids (1,400.1/L 33.1%). In lesser abundance were the rotifers (191.4/L) and nauplii larvae (121.7/L). Seasonal abundance maxima were highest in summer, followed by fall, spring and winter.

Seasonal Relationships Between Phytoplankton Composition, Abundance, And Primary Productivity In Three Tidal Rivers Of The Lower Chesapeake Bay, Harold G. Marshall, Kneeland K. Nesius

Biological Sciences Faculty Publications

The seasonal abundance and successional patterns of phytoplankton, including autotrophic picoplankton, are compared to spring, summer, and fall primary production maxima that occurred in three tidal rivers. The tidal freshwaters were dominated by diatoms, chlorophytes, and cyanobacteria during a late spring through early fall period of maximum growth. In contrast, downstream assemblages were dominated by estuarine diatoms, dinoflagellates, and cryptomonads which developed spring pulses and a protracted summer-fall maximum. Autotrophic picoplankton produced a major summer pulse at all river stations with reduced abundance during other seasons. The mean annual productivity rates for the tidal James, Rappahannock, and York rivers were …

F Response Frequency For The Median And Ulnar Nerves In A Normal Population, Patricia J. Killea

Rehabilitation Sciences Theses & Dissertations

The F wave or F response results form the recurrent discharge of antidromically activated anterior horn cells. F response latency represents an impulse which travels to and from the spinal cord through the central segment of a nerve. Study of the F wave is commonly done to assess proximal conduction in motor nerves, to measure motor nerve conduction velocity over a longer pathway than in orthodromic motor studies, and to assess motor neuron excitability. F response characteristics less commonly studied include duration, chronodispersion, shape, amplitude, and frequency. The primary purpose of this study was to determine F response frequencies of …

The Effects Of A Commercial Nutritional Supplement Combining Amino Acids, Glutamine, Carnitine And B-Vitamins On The Physiological Responses To Ultraendurance Triathlon Training, Performance And Recovery, Mary V. Mitchell

Human Movement Studies & Special Education Theses & Dissertations

In a placebo, double blind, randomized design, five male triathletes participated in a simulated triathlon which examined the physiological responses of a commercial nutritional supplement. The supplemental protocol included 7.1 gm·d^-1 of an amino acid complex with B-vitamins (AA) and between 2.2-7.3 gm·d^-1 META-MAX™ containing leucine, isoleucine, valine, glutamine and carnitine in which quantities were based on the athletes training volume. A maltodextrin carbohydrate replacement drink was also included in the protocol. The placebo was an isocaloric lactose substance. The supplements were ingested for 14 d prior to the simulated triathlon and then for 3 d after the …

Laminin Potentiates Differentiation Of Pcc4uva Embryonal Carcinoma Into Neurons, T. M. Sweeney, Roy C. Ogle, C. D. Little

School of Medical Diagnostics & Translational Sciences Publications

The embryonal carcinoma PCC4uva differentiates into neurons in response to treatment with retinoic acid and dbcAMP. We used this in vitro model system to study the effects of laminin on early neural differentiation. Laminin substrata markedly potentiate neural differentiation of retinoic acid and dbcAMP-treated cultures. Only laminin induced more rapid neural cell body clustering, neurite growth and neurite fasciculation as compared to type IV collagen, type I collagen, and fibronectin substrata. Exogenous laminin substrata promoted greater cell attachment, cellular spreading and growth to confluence than type IV collagen, type I collagen, fibronectin and glass substrata. Laminin-induced effects were inhibited by …

Morphological And Physiological Examination Of A Demyelinating And Remyelinating Lesion, Paul Anson Felts

Theses and Dissertations in Biomedical Sciences

Multiple sclerosis causes demyelination of central nerve fibers, and it is this pathology which results in most of the symptoms of the disease. The repair of the fibers by remyelination has been advanced as a potential symptomatic therapy, but at present the conduction properties of remyelinated central fibers are not well understood. In this study the conduction properties of Schwannian or oligodendrocyte remyelinated central nerve fibers have been determined. In addition, the status of the blood-brain barrier has been examined in lesions characterized by Schwann cell remyelination. These lesions chronically lack astrocytes, a cell believed to be involved in the …

Embryonic Chicken Fibroblast Collagen Binding Proteins: Distribution, Role In Substratum Adhesion, And Relationship To Integrins, Roy C. Ogle, A. Jeannette Potts, Marchall Yacoe, Charles D. Little

School of Medical Diagnostics & Translational Sciences Publications

Collagen binding proteins (CBP) are hydrophobic, cell surface polypeptides, isolated by collagen affinity chromatography. Antibodies to CBPs inhibit the attachment of embryonic chicken heart fibroblasts to native type I collagen fibrils in a dose-dependent manner. The CBP antibodies also induce rounding and detachment of cells adherent to a planar substratum. This process of antibody-mediated substratum detachment resulted in a clustering of CBP and cell-associated extracellular matrix at the cell surface, and the rearrangement of filamentous actin. Other functional studies showed that cells grown within a three-dimensional gel of type I collagen cannot be immunostained at the cell surface with CBP …

Changes In Caloric Content As A Result Of Sub-Lethal Stress In Neanthes Virens (Sars), Phyllis J. Friello

Biological Sciences Theses & Dissertations

Neanthes virens were subjected to a toxicity test with 1.8, 3.4, 6.7 and 11.0 mg/1 Cd²⁺. Worms were withdrawn on Days 1, 4, 7, 10 and 14 from each of five replicate tanks and their caloric content determined by bomb calorimetry. Analyses of variance and covariance showed no significant differences in worm caloric content with withdrawal day or cadmium concentration.

In a second experimental series, a sediment toxicity test with Neanthes virens was conducted in contaminated sediments from two sites, as well as reference sediments from a control site. Caloric content of the worms was measured by bomb …

Spectroscopic Study Of Decomposition Products Of Gossypol, David Bernard Hankins

Chemistry & Biochemistry Theses & Dissertations

Basic research into reproductive physiology has begun to identify possible new approaches to controlling fertility. Gossypol, a natural polyphenol compound isolated from cottonseed oil, has been shown to be an effective male antifertility agent. The decomposition products of gossypol which are thought to possess more potent antifertility effects than the parent compound gossypol have been studied extensively in more recent research. The purpose of this research is to develop techniques and methods which could be used to identify decomposition products of gossypol. A model decomposition reaction by which a smaller molecule can be isolated in a pure state has been …

Mounting Sex Pheromone: A Novel Pheromone Responsible For Mate Recognition In The Ixodidae, Jgc Hamilton

Theses and Dissertations in Biomedical Sciences

Cholesterol oleate was demonstrated to be the cuticular contact sex pheromone of Dermacentor variabilis. This pheromone which has been termed the Mounting Sex Pheromone (MSP) was also demonstrated to be present on the surface of D. andersoni, Amblyomma maculatum and A. americanum. This contact sex pheromone enables males excited and attracted by 2,6-dichlorophenol to identify the female as a potential mating partner. The MSP is the second in the series of three sex pheromones guiding the hierarchy of behavioral responses which constitute tick courtship behavior. Tests with D. variabilis and D. andersoni showed that this pheromone …

The Effects Of Various Lumbar/Sacral Back Support Systems Upon Human Peak Muscular Force, Total Work, And Average Power, Michael Lee Woodhouse

Theses and Dissertations in Urban Services - Urban Education

The purpose of the present investigation was to study the effects of two lumbar/sacral back supports upon peak muscular force, total work, and average power. Subjects consisted of ten well conditioned male volunteers with an age range of 21-35 years. Each subject volunteered individually to participate and was required to read and sign an inform consent form prior to participating in the investigation.

The investigative design was quasi-experimental with a repeated measures (treatment-by-subjects) methodology. Each subject experienced three testing treatments to include each lumbar/sacral support and one without. The testing protocol consisted of three isokinetic back testing devices developed by …

Quantitation And Identification Of Organic N-Chloramines Formed In Stomach Fluid On Ingestion Of Aqueous Hypochlorite, Frank E. Scully Jr., Katherine Mazina, Daniel E. Sonenshine, Frederick Kopfler

Biological Sciences Faculty Publications

The chemical reactions that hypochlorite undergoes in the body when chlorinated water is ingested have received very little attention. Because amino nitrogen compounds are important components of the average diet, the reactions of hypochlorite with amino compounds in the stomach were investigated. Stomach fluid was recovered from Sprague-Dawley rats that had been fasted for 48 hr and administered 4 mL deionized water. The chlorine demand of the stomach fluid was determined. An average volume-independent demand of 2.7 mg chlorine was measured. At doses below 40 mg/L chlorine reducing reactions appeared to account for reduction of all oxidizing species within 15 …

The Effects Of Varying Doses Of Orally Ingested Bee Pollen Extract Upon Total Exercise Time To Exhaustion Performance Recovery And Ratings Of Perceived Exertion, Michael Lee Woodhouse

Human Movement Studies & Special Education Theses & Dissertations

The purpose of the present investigation was to study the effects of varying doses of orally ingested bee pollen extract upon (1) treadmill run time to exhaustion and (2) initial ratings of perceived exertion (RPE) . Subjects consisted of five male aerobically trained athletes with an age range of 21 - 35 years. The subjects individually volunteered for the study and were active members of a local running club, The Tidewater Striders.

The bee pollen was given in three dosages (0, 1350 mg, 2700 mg). The three test periods on the treadmill consisted of six runs to exhaustion with a …

The Effect Of Blood Infusion Upon Perceived Exertion, Mary Aubert Lindhjem

Human Movement Studies & Special Education Theses & Dissertations

The purpose of this study was to determine the effect of packed RBC infusion upon ratings of perceived exertion (RPE), Three types of RPE were measured: 1) local muscular RFE, 2) cardiopulmonary RPE, and J) general RFE, The subjects, 16 experienced long distance male runners, undertook four treadmill runs to exhaustion, Subjects were matched according to time to exhaustion (ET) on the first trial (T1), and assigned to either an experimental (E) or control (C) group, Both groups had 46o ml blood withdrawn following Tl, T2 served as a baseline test and was administered about two weeks following blood withdrawal, …

The Effect Of Iron Supplementation On The Endurance Capacity Of The Female College Athlete, Barbara B. Sachon

Human Movement Studies & Special Education Theses & Dissertations

The major parameter of interest was the effect of iron supplementation on endurance capacity of female college athletes. Secondary parameters included the evaluation of the effect of iron supplementation on the following hematological variables: white blood cell count, red blood cell count, hemoglobin concentration, and hematocrit. Nineteen volunteer female students enrolled at the College of William and Mary in Williamsburg, Virginia served as subjects, All were members of the swimming team. All test trials and venipunctures were done at the women's gym at the College of William and Mary. There were two test periods.

All nineteen subjects performed a 500 …

The Effect Of Various Doses Of Caffeine Upon The Maximal Muscular Endurance Of College Females, Roberta Jane Perkins

Human Movement Studies & Special Education Theses & Dissertations

A limited number of investigations dealing with the effects of caffeine upon human physical performance have been conducted. Since caffeine is a central nervous system stimulant and it is a constituent of the popularly-consumed beverages - coffee, tea, and cola drinks, it would appear that numerous studies would have been conducted in order to determine the effect of caffeine upon human muscular performance. At any rate, there is a dearth of studies on this topic and the findings of the conducted experiments are equivocal and ambiguous.

The purpose of the present study was to determine the effects of various doses …

A Comparison Of Selected Isokinetic Training Velocities On The Development Of Muscular Power In College Women, Julia P. Knight

Human Movement Studies & Special Education Theses & Dissertations

The purpose of this study was to compare the effects of three different isokinetic velocities on the development of muscular power. Seventy-five college females were matched into four equal groups according to the average of their pre-test scores on the Vertical Power Jump Test and the Power Staircase Test. Group I served as the control group, while all 3 of the experimental groups performed the same isokinetic exercise at different pre-set rates of speed. Groups II, III and IV worked at the selected rates of .8, 2.3 and 3.9 inches per second respectively. All four groups were pre-tested and post-tested …

An Investigation Into The Incidence Of Psychogenic Factors Underlying The Temporomandibular Joint Pain/Dysfunction Syndrome, Ernest William Small

Human Movement Studies & Special Education Theses & Dissertations

No abstract.