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Articles 13111 - 13140 of 13206

Full-Text Articles in Medical Sciences

Mechanism Of Escape Of Endogenous Murine Leukemia Virus Emv-14 From Recognition By Anti-Akr/Gross Virus Cytolytic T Lymphocytes., Hillary D. White, Michael D. Robbins, William R. Green Jun 1990

Mechanism Of Escape Of Endogenous Murine Leukemia Virus Emv-14 From Recognition By Anti-Akr/Gross Virus Cytolytic T Lymphocytes., Hillary D. White, Michael D. Robbins, William R. Green

Dartmouth Scholarship

It was previously shown that spleen cells from endogenous ecotropic murine leukemia virus emv-14+ AKXL-5 mice fail to stimulate an anti-AKR/Gross virus cytolytic T-lymphocyte (CTL) response in a mixed lymphocyte culture with primed C57BL/6 responder spleen cells, whereas spleen cells from AKXL strains carrying the very similar emv-11 provirus do stimulate a response (Green and Graziano, Immunogenetics 23:106-110, 1986). We wished to determine whether the lack of response with AKXL-5 spleen cells was at the level of recognition between effector cell and target cell and whether the relevant mutation was within the emv-14 provirus. It is shown here that EMV-negative …


Macrophages But Not B Cells From Aged Mice Are Defective In Stimulating Autoreactive T Cells In Vitro, Aruna Seth, Mitzi Nagarkatti, Prakash S. Nagarkatti, Subbarao Bondada, Venkatachalam Udhayakumar Jan 1990

Macrophages But Not B Cells From Aged Mice Are Defective In Stimulating Autoreactive T Cells In Vitro, Aruna Seth, Mitzi Nagarkatti, Prakash S. Nagarkatti, Subbarao Bondada, Venkatachalam Udhayakumar

Microbiology, Immunology, and Molecular Genetics Faculty Publications

In the present study the effect of aging on the capacity of Ia+ cells to stimulate autoreactive T cells in the syngeneic mixed lymphocyte reaction (SMLR) was investigated. Using young CD4+ T cells as responders, it was observed that unseparated whole spleen cells from aged mice had normal stimulatory activity comparable to that of young spleen cells. Interestingly, however, when purified splenic adherant cells (SAC) enriched for macrophages or splenic B cells were used as stimulators, aged SAC but not aged B cells were found to be defective in stimulating autoreactive T cells. This defect in aged SAC …


Phenotypic And Functional Properties Of B Lymphocytes From Aged Mice, Subbarao Bondada, Joan Morris, Richard J. Kryscio Jan 1990

Phenotypic And Functional Properties Of B Lymphocytes From Aged Mice, Subbarao Bondada, Joan Morris, Richard J. Kryscio

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Phenotypic and functional properties of B lymphocytes from individual young and old mice of different inbred strains were studied. B lymphocyte subpopulation defined by the ratios of the densities of cell surface IgM and IgD were found to be altered with age. However, such alterations in B cell subsets were found only in 30-40% of the old mice. B cell mitogenic responses to anti-μ and anti-Lyb2 antibodies were decreased in a majority of DBA/2 mice. Proliferative responses to LPS and antiμ were reduced only in a minority of CBA/Ca mice but there was a very good correlation in the responsiveness …


Efficacy Of A Cell Extract From Actinobacillus (Haemophilus) Pleuropneumoniae Serotype 1 Against Disease In Swine, P. J. Fedorka-Cray, M.J. Huether, D.L. Stine, G. A. Anderson Jan 1990

Efficacy Of A Cell Extract From Actinobacillus (Haemophilus) Pleuropneumoniae Serotype 1 Against Disease In Swine, P. J. Fedorka-Cray, M.J. Huether, D.L. Stine, G. A. Anderson

School of Veterinary and Biomedical Sciences: Faculty Publications

We partially characterized a cell extract (CE) from Actinobacillus pleuropneumoniae serotype 1 and used the CE to test the efficacy of secreted proteins against disease. Secreted products from 4-h culture supernatants were precipitated with 20% polyethylene glycol. Analysis of the CE indicated the presence of protein, endotoxin, and carbohydrate. Hemolytic activity to bovine erythrocytes and cytotoxic activity to porcine mononuclear leukocytes was also demonstrated. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the CE from a 4-h culture showed a major band at 110 kilodaltons (kDa), while a CE of a 26-h culture indicated the presence of a number of additional …


Methionine Metabolism In Fasciola Hepatica, Carol Theresa Ayer Jan 1990

Methionine Metabolism In Fasciola Hepatica, Carol Theresa Ayer

Dissertations and Theses

5'-Deoxy-5'-methylthioadenosine (MTA) is derived from s-adenosylmethionine (AdoMet) during the synthesis of the polyamines spermidine and spermine. Methionine can be regenerated from MTA by one of two mechanisms. In mammalian cells and some microorganisms, MTA is degraded to adenine and 5-methylthioribose-1-phosphate (MTR-1-P) via MTA phosphorylase. In certain other microbes, however, MTA is catabolized in two steps; first to adenine and 5-methylthioribose (MTR) via MTA nucleosidase followed by conversion of MTR to MTR-1-P via MTR kinase.

This study was to demonstrate the presence of MTA nucleosidase or MTA phosphorylase in both redia containing cercariae and adult Fasciola hepatica Linnaeus, 1758. If MTA …


Progesterone And 17 Α-Hydroxyprogesterone: Novel Stimulators Of Calcium Influx In Human Sperm, Peter F. Blackmore, Stephen J. Beebe, Douglas R. Danforth, Nancy Alexander Jan 1990

Progesterone And 17 Α-Hydroxyprogesterone: Novel Stimulators Of Calcium Influx In Human Sperm, Peter F. Blackmore, Stephen J. Beebe, Douglas R. Danforth, Nancy Alexander

Bioelectrics Publications

Progesterone and 17 alpha-hydroxyprogesterone (but not other steroids such as testosterone, corticosterone, beta-estradiol, estrone, dehydroepiandrosterone, 20 alpha-hydroxypregnen-3-one, androstenedione, and pregnenolone) were shown to cause an immediate increase, in free cytosolic calcium ([Ca2+]i) in both capacitated and noncapacitated human sperm, using the fluorescent indicator fura 2. Significant increases in [Ca2+]i were observed with 10 ng/ml progesterone, while maximum effects were seen with 1 microgram/ml progesterone. Two other steroids 11 beta-hydroxyprogesterone and 5 alpha-pregnane-3,20-dione exhibited significant activity to increase [Ca2+]i. This increase in [Ca2+]i elicited by progesterone was entirely due to Ca2+ influx from the extracellular medium since the increase in [Ca2+]i …


Simian Virus 40 Host Range/Helper Function Mutations Cause Multiple Defects In Viral Late Gene Expression., Terryl Stacy, Michele Chamberlain, Charles N. Cole Dec 1989

Simian Virus 40 Host Range/Helper Function Mutations Cause Multiple Defects In Viral Late Gene Expression., Terryl Stacy, Michele Chamberlain, Charles N. Cole

Dartmouth Scholarship

Simian virus 40 (SV40) deletion mutants dlA2459 and dlA2475 express T antigens that lack the normal carboxy terminus. These mutants are called host range/helper function (hr/hf) mutants because they form plaques at 37 degrees C on BSC-1 and Vero monkey kidney cell lines but not on CV-1p monkey kidney cells. Wild-type SV40 can provide a helper function to permit growth of human adenoviruses in monkey kidney cells; the hr/hf mutants cannot. Progeny yields of hr/hf mutants are also cold sensitive in all cell lines tested. Patterns of viral macromolecular synthesis in three cell lines (Vero, BSC-1, and CV-1) at three …


Significance Of Premature Stop Codons In Env Of Simian Immunodeficiency Virus, Toshiaki Kodama, Dawn P. Wooley, Yathirajulu M. Naidu, Harry W. Kestler Iii, Muthiah D. Daniel, Yen Li, Ronald C. Desrosiers Nov 1989

Significance Of Premature Stop Codons In Env Of Simian Immunodeficiency Virus, Toshiaki Kodama, Dawn P. Wooley, Yathirajulu M. Naidu, Harry W. Kestler Iii, Muthiah D. Daniel, Yen Li, Ronald C. Desrosiers

Neuroscience, Cell Biology & Physiology Faculty Publications

The location of the translational termination codon for the transmembrane protein (TMP) varies in three infectious molecular clones of simian immunodeficiency virus from macaques (SIVmac). The SIVmac251 and SIVmac142 infectious clones have premature stop signals that differ in location by one codon; transfection of these DNAs into human HUT-78 cells yielded virus with a truncated TMP (28 to 30 kilodaltons [kDa]). The SIVmac239 infectious clone does not have a premature stop codon in its TMP-coding region. Transfection of HUT-78 cells with this clone initially yielded virus with a full-length TMP (41 kDa). …


Linker Insertion Mutants Of Simian Virus 40 Large T Antigen That Show Trans-Dominant Interference With Wild-Type Large T Antigen Map To Multiple Sites Within The T-Antigen Gene., Jiyue Y. Zhu, Charles N. Cole Nov 1989

Linker Insertion Mutants Of Simian Virus 40 Large T Antigen That Show Trans-Dominant Interference With Wild-Type Large T Antigen Map To Multiple Sites Within The T-Antigen Gene., Jiyue Y. Zhu, Charles N. Cole

Dartmouth Scholarship

Linker insertion mutants affecting the simian virus 40 (SV40) large tumor (T) antigen were constructed by inserting a 12-base-pair oligonucleotide linker into restriction endonuclease cleavage sites located within the early region of SV40. One mutant, with the insertion at amino acid 5, was viable in CV-1p and BSC-1 cells, indicating that sequences very close to the amino terminus of large T could be altered without affecting the lytic infection cycle of SV40. All other mutants affecting large T were not viable. In complementation assays between the linker insertion mutants and either a late-gene mutant, dlBC865, or a host range/helper function …


The Determination Of Tamoxifen Citrate In Human Blood Serum And Semen, Karimdad Tahmoresi Oct 1989

The Determination Of Tamoxifen Citrate In Human Blood Serum And Semen, Karimdad Tahmoresi

Chemistry & Biochemistry Theses & Dissertations

High performance liquid chromatography (HPLC)methodologies for the determination of tamoxifen and its metabolites 4-hydroxytamoxifen and n-desmethyltamoxifen, and using cis-tamoxifen as an internal standard have been developed.

Clinical analyses of tamoxifen and its metabolites in human serum and semen, were performed as follows: The analytes were extracted from serum and semen with hexane, the hexane evaporated, the dried extract then reconstituted with methanol, followed by reverse phase high performance liquid chromatography.

Between-run coefficients of variation (CV'S) for tamoxifen and n-desmethyltamoxifen for serum sample analyses, (n = 15) were, 4% and 13% at mean (SD) concentration of 140.2 (6.2) and 71.8 (9.8) …


Micronuclear Genome Organization In Euplotes Crassus: A Transposonlike Element Is Removed During Macronuclear Development, Scott Everet Baird, Gina M. Fino, Susan L. Tausta, Lawrence A. Klobutcher Sep 1989

Micronuclear Genome Organization In Euplotes Crassus: A Transposonlike Element Is Removed During Macronuclear Development, Scott Everet Baird, Gina M. Fino, Susan L. Tausta, Lawrence A. Klobutcher

Biological Sciences Faculty Publications

After mating, hypotrichous ciliated protozoa transform a set of their micronuclear chromosomes into thousands of short, linear DNA molecules that form the macronuclear genome. To examine micronuclear genome organization in the hypotrich Euplotes crassus, we have analyzed two cloned segments of micronuclear DNA as well as the macronuclear DNA molecules that are derived from them. E. crassus was found to display a number of features characteristic of other hypotrich genomes, including (i) clustering and close spacing of the precursors of macronuclear DNA molecules, (ii) the frequent occurrence of internal eliminated sequences within macronuclear precursors, (iii) overlapping macronuclear precursors, (iv) lack …


Effect Of Photoperiod On Developmental Morphology And Enolase Isoenzyme Immunohistochemistry In Rat And Djungarian Hamster Superficial Pineal Glands, Chalmer D. Mcclure Aug 1989

Effect Of Photoperiod On Developmental Morphology And Enolase Isoenzyme Immunohistochemistry In Rat And Djungarian Hamster Superficial Pineal Glands, Chalmer D. Mcclure

Loma Linda University Electronic Theses, Dissertations & Projects

The best understood functional activity of the pineal gland is its diurnal production of melatonin in response to environmental lighting cues. Several enzymes of the melatonin pathway respond to daily photoperiod changes, for example hydroxyindole-O-methyltransferase (HIOMT) and serotonin N-acetyltransferase (SNAT). Increased levels of the glycolytic enzyme neuron-specific enolase (NSE) are thought to reflect increased physiological demands placed on neurons and neuroendocrine tissues. Homodimer non-neuronal enolase isoenzyme (NNE) is immunolocalized to cells, and the hybrid enolase (consisting of subunits from NSE and NNE) has been seen in cerebellar stellate and basket cells. Although not rate limiting, concentrations of both NSE and …


In Vitro Evaluation Of Cancer Patient Immune Responses Following Infusion Of Radiolabeled Murine Monoclonal Antibody, Kelly A. King Jun 1989

In Vitro Evaluation Of Cancer Patient Immune Responses Following Infusion Of Radiolabeled Murine Monoclonal Antibody, Kelly A. King

Loma Linda University Electronic Theses, Dissertations & Projects

Several monoclonal antibody (MAb) types derived from mice have been developed specifically for the use of targeting human tumors. The specificity of these murine MAb’s for their respective tumor antigens is very high making them potentially good immunotherapeutic agents for cancer treatment and diagnosis. A limiting factor in using these murine MAb’s in patients is the development of human anti-mouse antibody (HAMA). The presence of HAMA may reduce the effectiveness of MAb for tumor targeting. If patient sensitization could be quickly detected following the initial infusion of MAb, then future infusion could be altered or terminated to prevent further sensitization. …


Autonomic Nervous System And Cholesterol Transport, Yuan-Line Hung Jun 1989

Autonomic Nervous System And Cholesterol Transport, Yuan-Line Hung

Loma Linda University Electronic Theses, Dissertations & Projects

The effect of autonomic nervous system on cholesterol transport is of clinical interest because the relationship between lipoprotein metabolism and atherogenesis is expressed in coronary artery disease.

Generally speaking, beta blockers increase serum VLDL level but decrease both HDL and HDL2 cholesterol levels without affecting the LDL in humans. We are unaware of reports concerning the effects of metoprolol on lipoprotein metabolism nor comparison of the effects of metoprolol and propranolol in the unhandled rat model. In part I we employed the unhandled rats to compared the effects of these 2 drugs administered with the drinking water in order …


Characterization Of Chromosome Fragmentation In Two Protozoans And Identification Of A Candidate Fragmentation Sequence In Euplotes Crassus, Scott Everet Baird, Lawrence A. Klobutcher Jan 1989

Characterization Of Chromosome Fragmentation In Two Protozoans And Identification Of A Candidate Fragmentation Sequence In Euplotes Crassus, Scott Everet Baird, Lawrence A. Klobutcher

Biological Sciences Faculty Publications

Following the sexual cycle, hypotrichous ciliated protozoans fragment a set of their micronuclear chromosomes to generate the thousands of short, linear DNA molecules present in the transcriptionally active macronucleus. We have used a hybrid selection procedure to examine macronuclear DNA molecules for subtelomeric length heterogeneity to determine whether chromosome fragmentation occurs at unique or multiple sites. The results suggest that multiple, but closely spaced, chromosome fragmentation sites are used by Oxytricha nova. In contrast, Euplotes crassus uses unique chromosome fragmentation sites in a reproducible manner to generate the ends of macronuclear DNA molecules. Additional studies compared DNA sequences in …


Isolation And Immunological Characterization Of A Group Of New B Lymphomas From Cba Mice, Venkatachalam Udhayakumar, Peter H. Brodeur, M. S. Rajagopalan, Stephen Zimmer, Karen E. Pollok, Subbarao Bondada Jan 1989

Isolation And Immunological Characterization Of A Group Of New B Lymphomas From Cba Mice, Venkatachalam Udhayakumar, Peter H. Brodeur, M. S. Rajagopalan, Stephen Zimmer, Karen E. Pollok, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

We have isolated and characterized a new series of B lymphomas which occurred spontaneously in a group of CBA N mice that were transferred with spleen or lymph node cells from 24-month-old CBA Ca mice. Tumor cell lines from six CBA N mice that received spleen cells were rescued and designated as BKS-2, BKS-3, BKS-4, BKS-5, BKS-6, and BKS-7. Also, tumor cells from a recipient of lymph node cells were rescued and the resulting cell line was designated BKL. These tumor cells expressed membrane immunoglobulin (μ,κ), major histocompatibility complex Class I and Class II molecules, B220, Lyb8, Fc receptors, J11d, …


A Specific Defect In The Proliferative Capacity Of B Cells From Old Mice Stimulated With Autoreactive T Cells, Prakash S. Nagarkatti, Aruna Seth, Mitzi Nagarkatti, Natarajan Muthusamy, Barbara Rychlik, Subbarao Bondada Jan 1989

A Specific Defect In The Proliferative Capacity Of B Cells From Old Mice Stimulated With Autoreactive T Cells, Prakash S. Nagarkatti, Aruna Seth, Mitzi Nagarkatti, Natarajan Muthusamy, Barbara Rychlik, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

B lymphocytes from aged mice were found to be defective in their ability to proliferate in response to stimulation with an autoreactive T cell clone D1.4. The differentiative response leading to antibody secretion was also impaired in the auto D1.4 T cell-stimulated B cells from old mice in comparison to similarly stimulated B cells from young mice. The B cells from old mice were competent in activating the autoreactive T cells such that the T cells were induced to proliferate. The B cell defect appears to be restricted to a certain phase of B cell activation, since old mouse B …


Duplication And Deletion 11q23-Q24 Recombinants In Two Offspring Of An Intrachromosomal Insertion ("Shift") Carrier, Miriam G. Forsythe, Hugh Walker, Lester Weiss, Jacquelyn R. Roberson, Maria J. Worsham, V. Ramesh Babu, Daniel L. Van Dyke Dec 1988

Duplication And Deletion 11q23-Q24 Recombinants In Two Offspring Of An Intrachromosomal Insertion ("Shift") Carrier, Miriam G. Forsythe, Hugh Walker, Lester Weiss, Jacquelyn R. Roberson, Maria J. Worsham, V. Ramesh Babu, Daniel L. Van Dyke

Henry Ford Hospital Medical Journal

Few examples of intrachromosomal insertions have been described. These usually result from deletion of a segment of chromosome material, with insertion of the deleted material elsewhere on the same chromosome. Previous insertional translocations have been identified through a proband who has either a deletion or a duplication of the inserted segment. We describe a family which has two probands, one with a duplication and one with a deletion of the inserted segment. The unbalanced chromosomes probably resulted from an uneven number of crossovers between the breakpoints in the chromosome 11 of the father, who carries a balanced intrachromosomal insertion of …


Population Amalgamation And Genetic Variation: Observations On Artificially Agglomerated Tribal Populations Of Central And South America, R Chakraborty, P E Smouse, J V Neel Nov 1988

Population Amalgamation And Genetic Variation: Observations On Artificially Agglomerated Tribal Populations Of Central And South America, R Chakraborty, P E Smouse, J V Neel

Faculty, Staff and Student Publications

The interpretation of data on genetic variation with regard to the relative roles of different evolutionary factors that produce and maintain genetic variation depends critically on our assumptions concerning effective population size and the level of migration between neighboring populations. In humans, recent population growth and movements of specific ethnic groups across wide geographic areas mean that any theory based on assumptions of constant population size and absence of substructure is generally untenable. We examine the effects of population subdivision on the pattern of protein genetic variation in a total sample drawn from an artificial agglomerate of 12 tribal populations …


Determination Of Antibody Levels In Periapical Lesions Against Sixteen Oral Microorganisms By The Elisa Technique, Sammee Lee Jones Jun 1988

Determination Of Antibody Levels In Periapical Lesions Against Sixteen Oral Microorganisms By The Elisa Technique, Sammee Lee Jones

Loma Linda University Electronic Theses, Dissertations & Projects

The root canal system, which includes the periapical region of the tooth, may become infected by several types of microorganisms which are normally associated with these tissues. A bacteria-specific antibody response may occur at the local level, where various classes of immunoglobulins have been found and reported in the literature. The purpose of this study was to quantitatively measure locally produced immunoglobulin' levels in periapical lesion abscess materials and to determine the specific reactivity of these antibodies to several microorganisms which are normal flora, as well as being previously associated with the development and pathogenesis of endodontic infections. Periapical lesions …


Parentage Analysis With Genetic Markers In Natural Populations I The Expected Proportion Of Offspring With Unambiguous Paternity, R Chakraborty, T R Meagher, P E Smouse Mar 1988

Parentage Analysis With Genetic Markers In Natural Populations I The Expected Proportion Of Offspring With Unambiguous Paternity, R Chakraborty, T R Meagher, P E Smouse

Faculty, Staff and Student Publications

Recent studies indicate that polymorphic genetic markers are potentially helpful in resolving genealogical relationships among individuals in a natural population. Genetic data provide opportunities for paternity exclusion when genotypic incompatibilities are observed among individuals, and the present investigation examines the resolving power of genetic markers in unambiguous positive determination of paternity. Under the assumption that the mother for each offspring in a population is unambiguously known, an analytical expression for the fraction of males excluded from paternity is derived for the case where males and females may be derived from two different gene pools. This theoretical formulation can also be …


Policy For Identifying And Assessing The Health Risks Of Toxic Substances, Maine Bureau Of Health Feb 1988

Policy For Identifying And Assessing The Health Risks Of Toxic Substances, Maine Bureau Of Health

Maine Collection

Policy for Identifying and Assessing the Health Risks of Toxic Substances

by Norman T. Anderson, Environmental Toxicology Program, Division of Disease Control, Bureau of Health (February, 1988).

Contents: Section I: Introduction / Section II: Methods / Section III: Exposure Assessment / Section IV: Hazard Identification / Section V: Hazard Assessment / Section VI: Risk Characterization / List of Figures / List of Tables


Properties Of Anti-Lyb-2-Mediated B-Cell Activation And The Relationship Between Lyb-2 Molecules And Receptors For B-Cell Stimulatory Factor-1 On Murine B Lymphocytes, Subbarao Bondada, Joan Morris, A. R. Baluyut Jan 1988

Properties Of Anti-Lyb-2-Mediated B-Cell Activation And The Relationship Between Lyb-2 Molecules And Receptors For B-Cell Stimulatory Factor-1 On Murine B Lymphocytes, Subbarao Bondada, Joan Morris, A. R. Baluyut

Microbiology, Immunology, and Molecular Genetics Faculty Publications

The murine B-cell differentiation antigen Lyb-2 has been shown to be involved in B-lymphocyte activation and has been postulated by some to be related to a receptor for B-cell stimulatory factor I (BSF-1) (H. Yakura et al., J. Immunol. 137, 1475, 1986). Here we have demonstrated that monoclonal antibody (mAB) to Lyb-2 resembles BSF-1 in its ability to activate small resting B cells and enhancement of surface Ia. Anti-Lyb-2 antibodies bound B cells with very high avidity and were able to induce mobilization of cytosolic-free calcium. Anti-Lyb-2 mAB differs from BSF-1 in that BSF-1 but not anti-Lyb-2 is able to …


Impaired Autoreactive T Cell-Induced T Cell-T Cell Interaction In Aged Mice, Venkatachalam Udhayakumar, Subbarao Bondada, Aruna Seth, Mitzi Nagarkatti, Prakash S. Nagarkatti Jan 1988

Impaired Autoreactive T Cell-Induced T Cell-T Cell Interaction In Aged Mice, Venkatachalam Udhayakumar, Subbarao Bondada, Aruna Seth, Mitzi Nagarkatti, Prakash S. Nagarkatti

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Self-Ia-reactive (autoreactive) L3T4+ T cell clones have been shown earlier to stimulate the proliferation of syngeneic naive L3T4+ T cells and initiate a T cell-T cell (T-T) interaction leading to the generation of immunoregulatory circuits. Since aging has been shown to be associated with a decline of the immune responsiveness, age-related alterations in the T-T interaction was investigated in the present study. Using several I-Ed-specific autoreactive T cell clones isolated from 2- to 3-month-old (young) DBA/2 mice as stimulators, it was observed that L3T4+ T cells from 22- to 24-month-old (aged) DBA/2 mice, failed to …


Improved Selective Medium For The Isolation Of Treponema Hyodysenteriae, Robert A. Kunkle, J. M. Kinyon Jan 1988

Improved Selective Medium For The Isolation Of Treponema Hyodysenteriae, Robert A. Kunkle, J. M. Kinyon

School of Veterinary and Biomedical Sciences: Faculty Publications

An agar medium with improved selection for Treponema hyodysenteriae was developed. Cultures of T. hyodysenteriae and T. innocens, feces from 11 clinically normal pigs, and colonic contents from 6 pigs with gross lesions consistent with swine dysentery were diluted in phosphate-buffered saline and plated on Trypticase soy agar (BBL Microbiology Systems, Cockeysville, Md.) with 5% citrated bovine blood (TSA), TSA with 400 ,ug of spectinomycin per ml (TSA-S400), TSA-S400 with 25 ,ug each of colistin and vancomycin per ml, and TSA with 5% pig feces extract and five antimicrobial agents (spiramycin, rifampin, vancomycin, colistin, and spectinomycin) (BJ). Viable numbers …


An Identified Histaminergic Neuron Can Modulate The Outputs Of Buccal-Cerebral Interneurons In Aplysia Via Presynaptic Inhibition, Hillel J. Chiel Jan 1988

An Identified Histaminergic Neuron Can Modulate The Outputs Of Buccal-Cerebral Interneurons In Aplysia Via Presynaptic Inhibition, Hillel J. Chiel

Faculty Scholarship

We have identified 2 buccal-cerebral interneurons (BCIs), B17 and B18, that appear to be involved in the coordination of feeding behavior in Aplysia. The BCIs have their cell bodies in the buccal ganglion, but send axons to the cerebral ganglion via the cerebral-buccal connectives. The BCIs appear to make monosynaptic connections with neurons in the cerebral ganglion that modulate extrinsic muscles involved in feeding behavior. B17 and B18 are activated antiphasically during a motor program induced by stimulating the esophageal nerve and appear to 'read out' different phases of the buccal program to different cells in the cerebral ganglion. B17 …


Hyperosmotic Modification Of Brain Extracellular Space And Blood-Brain Barrier In The Rat As Observed By Electron Microscopy, Susan A. Meacham Dec 1987

Hyperosmotic Modification Of Brain Extracellular Space And Blood-Brain Barrier In The Rat As Observed By Electron Microscopy, Susan A. Meacham

Loma Linda University Electronic Theses, Dissertations & Projects

The highly selective permeability of cerebral blood vessels, termed the blood-brain barrier, is due to endothelial tight junctions (zonulae occludentes). Hyperosmotic solutions reversibly open the blood-brain barrier. The purpose of this study is to determine the immediate effect of hyperosmotic arabinose perfusion upon the cerebrovascular endothelium, the morphology of the cerebral cortex, and the cortical extracellular space.

Twelve adult male Sprague-Dawley rats were separated into three groups of four animals each: control, intermediate, and extreme. Controls were perfused with a Tyrode's solution prewash followed by trialdehyde fixative. The intermediate group received a prewash of 740 mmol/kg arabinose followed by the …


Early Events In B-Cell Activation: Anti-Lyb2, But Not Bsf-1, Induces A Phosphatidylinositol Response In Murine B Cells, Stephan A. Grupp, Judith A. K. Harmony, Arthur R. Baluyut, Subbarao Bondada Jan 1987

Early Events In B-Cell Activation: Anti-Lyb2, But Not Bsf-1, Induces A Phosphatidylinositol Response In Murine B Cells, Stephan A. Grupp, Judith A. K. Harmony, Arthur R. Baluyut, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Previous studies have indicated that the murine surface antigen Lyb2 is involved in an activation pathway that apparently does not involve the surface immunoglobulin receptor. As sIg has been shown to transduce its activation signal through the breakdown of phosphatidylinositol (PI), and since activation via Lyb2 does not involve sIg, it was of interest to determine if binding to Lyb2 generates a PI response. We have demonstrated that an allele-specific monoclonal antibody to Lyb2 (anti-Lyb2 mab), which has previously been shown to drive B cells into S, also activated PI metabolism in these cells. This activation occurred in a dose-dependent …


Production From Heifers And First Calvers, G J. Sawyer Jan 1987

Production From Heifers And First Calvers, G J. Sawyer

Journal of the Department of Agriculture, Western Australia, Series 4

Heifers and first calvers present the major problems of the beef breeding herd. Reproduction rates, calf growth and survival of first calvers are generally much poorer than those of adult breeders.

Early successful reproductive performance is important in beef herds because of the high overhead cost of keeping breeding beef heifers or cows, Where possible, beef producers should aim to join heifers at 14 to 15 months of age. To achieve this goal, producers should set production targets for those animals. These targets will differ from farm to farm depending on when calves are turned off and the seasonal feed …


The Effects Of Xanthine Analogs On Neonatal Rat And Adult Mouse Respiration, Susan M. Reynolds Jan 1987

The Effects Of Xanthine Analogs On Neonatal Rat And Adult Mouse Respiration, Susan M. Reynolds

Masters Theses

Apnea, a prolonged cessation of breathing, is commonly seen in premature infants. This condition, in its severest form, can be lethal and is a suspected cause of sudden infant death syndrome (SIDS). Sometimes referred to as apnea of prematurity, recurrent apnea is presently being treated with respiratory stimulants known as methylxanthines (MX) such as theophylline and caffeine. The benefits of MXs are accompanied by central nervous system stimulation and cardiostimulation which may be detrimental to a premature infant. Theophylline (1,3-diMX) has been shown to produce some of its effects by antagonizing endogenous adenosine. Another xanthine, enprofylline (3-propylxanthine), is presently being …