Life Sciences Commons^™

Coxsackievirus B4 Induced Diabetes In Cd-1 Mice, Mary C. F. Anderson

Theses and Dissertations

Most evidence to date clearly indicates that CB4 virus can affect the pancreas of both man and mice during acute infection. Yet, conflicting evidence exists relative to the consequence of the infection in both man and mice. The study described here attempted to provide definitive evidence on the relative role of the virus isolate (i.e. heterogenous virion populations vs. purified clones) in induction of prolonged diabetes-like disease in mice.

Effects Of Pulsed Electric Fields On Mammalian Cell Membranes, Guy K. Smith

Theses and Dissertations

The effect of pulsed electric fields on cell membranes were studied to investigate the effects of an electric field, per se, on biological systems, without the densometric and other technical problems associated with other forms of nonionizing radiation. Exposure of mouse splenocytes to a high voltage pulse resulted in an increase in membrane permeability to K⁺ that was dependent on both the electric field strength and the pulse duration. Exposure to a 2 μsec, 3.0 kV/cm pulse elicited a 50% loss of intracellular K⁺ indicating that the critical transmembrane potential (V_m) at breakdown was 1.26 volts …

An Evaluation Of The Central Neurotoxic Effects Of Aroclor 1254, A Commercial Mixture Of Polychlorinated Biphenyls, In Mice, Diane L. Rosin

Theses and Dissertations

Polychlorinated biphenyls (PCBs) are industrial compounds whose ubiquitous environmental contamination has been known since the late 1960's. Incidents of human intoxication have been reported, most notably, the "Yusho" incident that affected over 1600 people in Japan in 1968. A broad spectrum of adverse effects are produced by PCBs, including some neurological symptoms. While examination of the toxic effects of PCBs has received much attention, there has been little work on the neurotoxicity of PCBs. The intent of the experiments presented in this thesis is to provide further information on the central neurotoxicity of PCBs in mice.

A commercial mixture of …

Nuclear Envelope Proteins: Chemical Characteristics And Molecular Interactions Of The Lamins, David Lee Cochran

Theses and Dissertations

The lamins are a group of proteins in a residual nuclear envelope fraction derived from the nuclear lamina. The absence of specific functional assays for the two predominant species, lamin A and lamin B, has complicated their biochemical characterization. Initial studies reported in this work involved the enzymic cleavage of isolated lamins A and B and another lamina protein with a molecular weight of 61,000-daltons. The results obtained with each of three enzymes indicated strong similarities between the three nuclear envelope proteins.

Further chemical characterization of the lamins has been achieved. Lamins A, B and C have been separated by …

Enflagellation Of Naegleria Fowleri, Terry Wayne Woodworth

Theses and Dissertations

Organisms of the genus Naegleria differentiate from feeding, dividing amebae into temporary swimming flagellates when deprived of nutrients. Factors critical for enflagellation of the pathogenic species, N. fowleri, were delineated and optimal conditions established for evoking reproducible conversion of N.fowleri populations. N. fowleri enflagellation differed from that of N. gruberi in its dependence upon growth phase, population density during enflagellation and in the timing and extent of the conversion. N. fowleri amebae from stationary phase cultures grown at 37°C, washed free of medium and suspended in nutrient~free ameba saline, acquired flagella and converted to mature flagellates in a synchronous manner …

Multivariate Analyses Of Mid-Winter Fattening In Two Species Of Passerine Birds, Michael Harold Shelor

Theses and Dissertations

Although the adaptive significance of daily and seasonal fattening of birds has been studied by many investigators (see Odum, 1965; King, 1972; Blem, 1976a), surprisingly little is known about the interactions of proximate and ultimate environmental factors regulating avian lipid levels. An exception is the study by Evans (1969). He found that lipid levels in Yellow Buntings (Emberiza citrinella) were more closely correlated with long-term temperature averages than with temperatures of the day of capture, or the days preceding or following capture. This is an indication that temperature may be more important as an ultimate control of fattening, through natural …

Genetic Studies Of Questionnaire Data From A Residential School For The Deaf, Frederick Robert Bieber

Theses and Dissertations

A self-administered thirteen page Hearing Loss Questionnaire (HLQ) was designed in order to systematically collect medical and family history data on deaf children and their families. Data were collected from over 400 families with one or more children enrolled in September 1979 at the Maryland School for the Deaf (MSD). Almost 70% of the parents provided pedigree and family history information by completing the detailed HLQ. Computer analyses of the collected data allowed a thorough examination of almost 200 medical and family history variables, providing useful reference data on the MSD probands. Parental responses to a four-step rating scale of …

Solubilization And Partial Characterization Of An Activity Regulating Complement Activation From Membranes Of Raji And Tonsil Cells, Patricia L. Carlson

Theses and Dissertations

Complement is one of the major innate nonspecific mechanisms for host defense in serum. More than a dozen proteins have been isolated from serum which have a function in either the activation or regulation of complement action. Complement is similar to the coagulation sequence in that it comprises a number of precursor proenzymes in plasma that are sequentially cleaved to generate biologically and enzymatically active proteins.

The Role Of Retained Antigen As An Etiological Agent In Rheumatoid Arthritis, Patricia Liccardi Rice

Theses and Dissertations

The cause(s) of arthritis and many other connective tissue diseases are largely unknown. An infectious agent, either bacterial or viral, has not been unequivocally isolated. Theories on the pathogenesis of arthritis abound. Many of these theories implicate the immune system as the problem.

The early information on animal arthridites implicates retained bacterial cell wall antigens as the basis of the arthritis seen. How-ever, numerous types of antigens, both complex polymers and simple proteins, have been shown to persist in immune animals. The antigens persist in the lymph nodes and spleens playing a role in mediating antibody feedback mechanisms. Antigens also …

Effects Of Glucocorticoid Treatment On The Properties Of Single Notor Units In Cat Hindlinb Huscles, Andrew James Robinson

Theses and Dissertations

The administration of glucocorticoids has been shown to induce atrophy and weakness in whole skeletal muscle. These effects frequently appear to be more pronounced in pale muscle than in red muscle. The present study was undertaken to examine the effects of steroid treatment on the contractile, electrical, and fatigue properties of single meter units in pale and red cat hindlimb muscles. Single motor units in the medial gastrocnemius (MG) and soleus muscles were isolated using techniques developed by McPhedran, et al., (1965). The properties of a large number of motor units were examined in normal animals and were compared to …

The Chronic Effects Of Estradiol Benzoate On Ventricular Myocardial Blood Flow In The Adult Female Rat, Stephen Maurice Ashe

Theses and Dissertations

Clinical and experimental data suggest that humans and some animals are protected from acute myocardial infarction by estrogen. There has been much speculation of the exact role which estrogen plays in the circulation. The mechanism of this hormonally related protection is unclear.

In the present study the chronic effects of estradiol benzoate on coronary blood flow in adult female rats were studied. Female control rats, castrates and castrates receiving estrogen for a period of 16 weeks were used. In vivo tracer microsphere studies of myocardial blood flow allowed the quantification of the effects of estrogen on coronary circulation. Results of …

An Analysis Of The Fit Of The Negative Binomial Distribution To Frequencies Of Episodes Of Illness, Philip Melville Brennan Jr.

Theses and Dissertations

In recent years, much interest has been shown in "modeling," or fitting, primary care data to known statistical distributions. Specifically, much work has been done in studying the distributions of episodes of illness and consultations in family practices. This thesis will examine the utility of the negative binomial distribution's fit to family practice data.

Genetic Heterogeneity In Complementation Groups Of Propionic Acidemia, Catherine Mckeon

Theses and Dissertations

Propionic acidemia is an autosomal recessively inherited disorder of organic acid metabolism caused by deficient activity of propionyl CoA carboxylase. This enzyme is required for the catabolism of the odd-chain fatty acids, the side chain of cholesterol and the amino acids: isoleucine, methionine, and threonine. Although the clinical expression of this disorder is variable, affected children usually develop ketoacidosis and hyperammonemia which may progress to seizures, coma and possibly death. Some patients may exhibit vomiting, lethargy and hypotonia in the first few weeks of life whereas others may remain asymptomatic for months or even years.(1) The degree of residual enzyme …

Psychopharmacological Analysis Of Central Muscarinic And Nicotinic Receptors, Leonard T. Meltzer

Theses and Dissertations

Arecoline and nicotine are two psychoactive cholinergic alkaloids. Arecoline is primarily a muscarinic agonist while nicotine, at low doses, is a nicotinic agonist. The experiments in this dissertation investigated two major areas: (1) the role of different factors in the development of tolerance to the behavioral effects of arecoline and nicotine, and (2) the possible mechanism and site of action of the discriminative stimulus (DS) effects of arecoline and nicotine.

The role of dispositional and physiological factors comfiared to behavioral factors in the development of tolerance to the effects of arecoline and nicotine on operant behavior was assessed in Experiments …

An Interphysiographic Analysis Of Herb And Shrub Vegetation In Virginia Forests, Stephen James Binns

Theses and Dissertations

Thirty upland deciduous stands were sampled from the mid-coastal Plain to the mid-Piedmont in New Kent, Hanover, and Louisa Counties. Density data for herb and shrub species were collected and soil samples were collected in each stand. A cluster analysis of the vegetation data was performed using Euclidean Distance and "furthest-neighbor" clustering. Four clusters of stands were identified. A cluster of six stands with Euonymus americanus as the dominant species was strongly related to the Coastal Plain, but the other clusters were not physiographically associated. Other important species in the analysis were Vaccinium vacillans, Gaylussacia baccata, and Mitchella repens.

The …

Efficacy Of Salinomycin On Infections Of Plasmodium Berghei In Male Icr Mice, Anthony Stephen Tokarz

Theses and Dissertations

The objective of this study was to determine whether or not salinomycin, a drug with proven effectiveness against intestinal sporozoan parasites, has any effect on the survival time of mice infected with P. berghei.

Antiviral Activity Of Peritoneal Exudate Cells Of Mice Against Infection With Herpes Simplex Virus Type 2, Margaret Byrd Mcgeorge

Theses and Dissertations

Within the past decade, there has been increasing evidence which suggests that herpes simplex virus type two (HSV-2) is associated with cervical carcinoma. Because cancer of the cervix ranks as the second most common malignant disease of women, with 35 thousand new cases and 10,000 deaths per year, further investigation is warranted to determine if there is a causal relationship (Goldberg, 1976). Currently, most of the evidence which correlates HSV-2 with cancer of the cervix has been, for the most part, indirect: (i) there is an increased incidence of cervical anaplasia in women with cytologically detectable genital herpes infection, (ii) …

Characterization Of The Bursicon-Mediated Pathway For Membrane Permeability Enhancement In The American Cockroach, Periplaneta Americana, David Alan Compton

Theses and Dissertations

The presence of an adenyl cyclase system within the haemocyte of Periplaneta americana has been confirmed by previous investigations, with corresponding experiments using dibutyryl cyclic AMP to show enhancement of 14c-tyrosine uptake into the cuticle linked to stimulation of the sclerotization process.

In the present studies, American cockroaches held at depressed temperatures were treated with bursicon, revealing an increase in haemocyte cyclic AMP concentrations. The levels declined with progression of time, probably resulting from enzymatic hydrolysis.

When animals which had been held at room temperature were treated with bursicon, the levels of haemocyte cyclic AMP were lowered, with a declination …

The Effects Of Streptozotocin-Induced Diabetes On Responses To Opiates And Other Centrally-Acting Pharmacologic Agents, Glenn Stuart Simon

Theses and Dissertations

Diabetes mellitus affects millions of people. Although diabetics can lead relatively normal lives, all treatments for the disease are symptomatic and not curative. The purpose of this investigation was to determine whether the sensitivity to opiates and other selected centrally-acting drugs in animals is altered by streptozotocin (STZ)-induced diabetes. A second objective was to determine which aspect of the diabetic syndrome primarily was responsible for the altered sensitivity. Other experiments were performed in an attempt to elucidate the mechanism whereby this altered sensitivity occurred.

STZ-induced diabetes or dextrose-induced transient hyperglycemia did not have a significant effect on the duration of …

Oncogenic Transformation By Herpes Simplex Virus, James Christian Burns

Theses and Dissertations

Many lines of evidence exist associating herpes simplex virus (HSV) with the development of carcinoma. Data from human studies includes seroepidemiologic studies of carcinoma patients and the localization of viral markers in human cancers. Experimental studies include in vitro transformation of cultured cells and viral induced alterations of host DNA. Much of this evidence is anecdotal or associative in nature and does not prove a cause and effect. The purpose of this research was to investigate the oncogenic potential of HSV type 2 (HSV-2) in vivo and in vitro.

An in vivo mouse model for lib carcinogenesis was designed to …

The Responsiveness Of Murine Tumors To Maleic Vinyl Ether, Paal Christian Klykken

Theses and Dissertations

Studies were undertaken to characterize the immune status of mice bearing the Lewis lung carcinoma (LLC) and to maximize the cure rate of LLC and Madison l09 carcinoma (Ml09) bearing mice by employing the immunomodulator maleic vinyl ether (MVE) in combination with surgery or radiotherapy.

The pattern of immunodeficiency in mice bearing the LLC appeared to be in contrast to most studies. LLC mice with a minimal tumor burden were found to have a diminished ability to phagocytize sheep erythorcytes (SRBC) or elicit an antibody response to the same antigen. Vascular clearance and phagocytic uptake of ⁵¹Cr-labeled SRBC into …

Intravenous Infection Of Mice With Naegleria Fowleri, Richard G. May

Theses and Dissertations

Primary amebic meningoencephalitis is a fatal disease of man caused by the free-living ameboflagelate Naegleria fowleri. In general, the victims have been active, healthy, young adults with a recent history of swimming or other fresh water-related activity. Infection with N. fowleri is apparently by way of nasal introduction of amebae-containing water. After nasal installation, electron microscopic and histopathologic studies with experimental animals reveal that amebae reside in the olfactory mucosa and then invade and migrate through the submucosal structures into the nerve plexuses. Amebae pass through pores of the cribiform plate and into the subarachnoid space. Subsequently, amebae invade the …

The Biological And Structural Characterization Of Transferable Bacteroides R Plasmids, Rodney A. Welch

Theses and Dissertations

In this literature review I will briefly describe the general biology of transferable antibiotic resistance in bacteria, the genetic elements involved (plasmids) and several specific plasmid associated phenotypes. This will be followed with a review of the general biology of Bacteroides, the information known concerning its plasmid reservoir and finally a review of the information documenting the emergence of transferable clindamycin resistance in Bacteroides. The latter aspect represents the central focus of research described in this thesis.

Temporal Aspects Of Calling Behavior In Oyster Toadfish, Opsanus-Tau, Michael L. Fine

Biology Publications

The oyster toadfish, Opsanus tau (Linnaeus), produces two calls: an agonistic grunt and a boatwhistle associated with courtship (Fish 1954; Tavolga 1958,1960; Gray and Winn 1961). The boatwhistle is produced only by males on nests (Gray and Winn 1961) and is endogenously driven as well as influenced by calling of surrounding males (Winn 1964, 1967, 1972; Fish 1972). A toadfish, not hearing other males, may still boatwhistle for long periods and attract a female. Although toadfish may be influenced to call by the calling of adjacent males, one would assume the circadian patterning of the boatwhistle to be influenced by …

Direct Chemical Evidence For A Supramolecular Protein Structure In The Nuclear Envelope, David Lee Cochran

Theses and Dissertations

Protein subunit structure in the nuclear envelope has not been previously described. Covalent crosslinking of polypeptides provides a method for studying the subunit structure of protein-rich systems. In this study, several polypeptide crosslinking methods have been used to determine associations among polypeptides in isolated chicken erythrocyte nuclear envelope. Interchain associations that exist in the isolated membrane were fixed by crosslinking the polypeptides in the isolated nuclear envelope. Crosslinked and uncrosslinked polypeptides were resolved by electrophoresis in a dissociating detergent system. Each agent caused distinctive alterations in the gel pattern. Certain bands diminished and disappeared while new bands of two or …

A Spectrophotofluorometric Analysis Of Serum Vitamin A Levels In A Defined Population, James Ronald Schroeder

Theses and Dissertations

The objectives of this thesis were to examine serum vitamin A levels in two defined populations. The method of analysis was a spectrophotofluorometric technique with a correction formula to account for interfering fluorescence from an identified carotenoid phytofluene (37).

The first population were infants at time of delivery. Infants were divided into two groups depending upon length of gestation. A premature group was identified as having a length of gestation of less than 36 weeks. Term infants were defined as 36 weeks or greater. The mean value of serum vitamin A of eight premature infants was 10.5 μg/100ml (S.E.M.+.78). The …

Incorporation Of Phosphoproteins And Phenol-Bound Proteins Into The Cuticle Of Periplaneta Americana, Joseph Atchison Florence Iv

Theses and Dissertations

The incorporation of phosphoproteins and phenol-bound proteins into the cuticle of Periplaneta americana was analyzed. Radioactive monosodium phosphate was injected into newly ecdysed cockroaches. Incorporation into haemolymph proteins as well as tanned cuticle was observed. Phosphoproteins were observed to be combined with the cuticle to a greater extent than monosodium phosphate. This suggests that phosphate is being incorporated into the cuticle more readily than monosodium phosphate. The relevance of these observations is discussed in light of phosphate being a possible crosslinking agent between chitin and cuticle protein.

Binding of dopamine metabolites to cuticle proteins was investigated. Specific metabolites studied were …

Food Habits Of The Game Fishes Of Lake Anna, Virginia, Thomas Kenneth Rohrer

Theses and Dissertations

Beginning in May, 1973 and continuing through August, 1974 the food habits of several species of game fishes from Lake Anna, Virginia were investigated via gut content analysis. A variety of collecting methods were employed to secure specimens for examination and stomach contents were reported as percent frequency of occurrence. A total of one hundred and two collections were made yielding 287 largemouth bass, Micropterus salmoides (Lacépède); 166 chain pickerel, Esox; niger LeSueur; 53 bluegill, Lepomis macrochirus Rafinesque; 32 pumpkinseed, Lepomis gibbosus (Linnaeus); and 63 black crappie, Pomoxis nigromaculatus (LeSueur). It was found that M. salmoides and E. niger were …

Distribution And Effects Of Bacterial Endotoxin, Anne Carter Adams

Theses and Dissertations

In this study the distribution and effects of bacterial endotoxin were examined. Adult male BALB/c and adult male DUB/ICR mice were used in all experiments. Endotoxic activity of a number of strains from three genera of bacteria, Pseudomonas, Bacteroides, and Listeria, was detected using vincristine-treated mice as sensitized indicators for endotoxin and resistance to purified endotoxin induced by pretreatment with selected bacteria. Also, the effect of bacterial endotoxin and endotoxin-like substances on the course of primary amebic meningoencephalitis in mice, caused by Naegleria fowleri, was assessed.

Activation Of The Gamma Motor System In The Cat Following Selective Stimulation Of The Motor Cortex And The Pyramidal Tract, James Elliott Forbes

Theses and Dissertations

Until the mid to late 1800's, the cerebral hemispheres were considered to be only the sites of mentation and intellectual activity. On the basis of his observations of epileptic patients, HughIings Jackson (cited from Walshe, l935a) theorized that the cerebral hemispheres were also sites of motor control and sensory experience. The electrical excitability of the cerebrum was first demonstrated by Fritsch and Hitzig in 1870. Since then the motor representation of the various muscles has been mapped out and the types of movement in response to stimulation of the motor cortex and the pyramidal tract have been thoroughly studied.

Mammalian …