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1994

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Articles 1 - 30 of 57

Full-Text Articles in Medical Sciences

Sidedness Of H+ Action On K-Cl Cotransport In Dids Ph(I)-Clamped Low K Sheep Red Blood Cells With Reduced Mg(I), Peter K. Lauf, Norma C. Adragna Dec 1994

Sidedness Of H+ Action On K-Cl Cotransport In Dids Ph(I)-Clamped Low K Sheep Red Blood Cells With Reduced Mg(I), Peter K. Lauf, Norma C. Adragna

Pharmacology and Toxicology Faculty Publications

No abstract provided.


Dependence Of Thiol-Stimulated K-Cl Cotransport On Redox State Of Low K Sheep Red Blood Cells, Peter K. Lauf, Norma C. Adragna, Nihal S. Agar Dec 1994

Dependence Of Thiol-Stimulated K-Cl Cotransport On Redox State Of Low K Sheep Red Blood Cells, Peter K. Lauf, Norma C. Adragna, Nihal S. Agar

Pharmacology and Toxicology Faculty Publications

No abstract provided.


Aids Epidemiology: A Quantitative Approach, Ron Brookmeyer, Mitchell Gail Nov 1994

Aids Epidemiology: A Quantitative Approach, Ron Brookmeyer, Mitchell Gail

Ron Brookmeyer

This comprehensive work confronts the problems that are unique to AIDS research and unites them under a single conceptual framework. It focuses on methods for the design and analysis of epidemiologic studies, the natural history of AIDS and the transmission of HIV, methods for tracking and projecting the course of the epidemic, and statistical issues in therapeutic trials. The various methods of monitoring and forecasting this disease receive comprehensive treatment. These methods include back-calculation, which the authors developed; interpretation of survey data on HIV prevalence; mathematical models for HIV transmission; and approaches that combine different types of epidemiological data. Much …


Progressive Cross-Linking Of Fibrin Gamma Chains Increases Resistance To Fibrinolysis, Kevin R. Siebenlist, Michael W. Mosesson Nov 1994

Progressive Cross-Linking Of Fibrin Gamma Chains Increases Resistance To Fibrinolysis, Kevin R. Siebenlist, Michael W. Mosesson

Biomedical Sciences Faculty Research and Publications

In the presence of plasma transglutaminase (factor XIIIa) fibrin first undergoes intermolecular covalent cross-linking between its gamma chains to create gamma dimers followed by slower cross-linking among its alpha chains to form alpha polymers. Progressive cross-linking of gamma chain dimers occurs at the slowest rate, resulting in gamma trimers and gamma tetramers (“gamma multimers”). Most studies indicate that cross-linked fibrin clots become resistant to fibrinolysis, but the basis for this event is not clear. In this study, we explored the role of gamma chain multimerization compared with alpha polymerization as causal factors in time-dependent development of resistance to fibrinolysis. Fibrin …


Hypoglycemia And Hyperinsulinemia In Rodent Models Of Severe Malaria Infection, Khalid M. Elased, J. H. L. Playfair Nov 1994

Hypoglycemia And Hyperinsulinemia In Rodent Models Of Severe Malaria Infection, Khalid M. Elased, J. H. L. Playfair

Pharmacology and Toxicology Faculty Publications

Severe hypoglycemia developed during nonlethal Plasmodium chabaudi and lethal P. yoelii blood stage malaria infection in mice, always in association with hyperinsulinemia. Supernatants of lethal P. yoelii incubated overnight induced hypoglycemia and hyperinsulinemia in normal mice. In murine malaria, hypoglycemia may be largely secondary to increased insulin secretion.


Alumni News Volume 1 No. 3, Touro College Barry Z. Levine School Of Health Sciences Oct 1994

Alumni News Volume 1 No. 3, Touro College Barry Z. Levine School Of Health Sciences

Yearbooks and Newsletters

No abstract provided.


Update - September 1994, Loma Linda University Center For Christian Bioethics Sep 1994

Update - September 1994, Loma Linda University Center For Christian Bioethics

Update

In this issue:

-- Ritualized Genital Mutilation the Procedure
-- A Cultural Perspective
-- Female Genital Mutilation: A Question of Fundamental Human Rights
-- Ethics When Cultures Clash
-- Ethics Consultation (Review)


Review Of: The Genetic Frontier: Ethics, Law, And Policy (Mark S. Frankel & Albert Teich Eds., American Association For The Advancement Of Science 1994), Suzanne A. Sprunger Sep 1994

Review Of: The Genetic Frontier: Ethics, Law, And Policy (Mark S. Frankel & Albert Teich Eds., American Association For The Advancement Of Science 1994), Suzanne A. Sprunger

RISK: Health, Safety & Environment (1990-2002)

Review of: The Genetic Frontier: Ethics, Law, and Policy (Mark S. Frankel & Albert Teich eds., American Association for the Advancement of Science 1994). Acknowledgments, appendix, contributors, figures, index, introduction, notes, references, tables. LC 93-37230, ISBN 0-87168-526-4. [260 pp. Paper $22.95. 1333 H St., NW, Washington DC 20005.]


Effects Of Natural Sequence Variation On Recognition By Monoclonal Antibodies Neutralize Simian Immunodeficiency Virus Infectivity, Weon Sang Choi, Catherine Collignon, Clotilde Thiriart, Dawn P. Wooley, E. J. Scott, Karen A. Kent, Ronald C. Desrosiers Sep 1994

Effects Of Natural Sequence Variation On Recognition By Monoclonal Antibodies Neutralize Simian Immunodeficiency Virus Infectivity, Weon Sang Choi, Catherine Collignon, Clotilde Thiriart, Dawn P. Wooley, E. J. Scott, Karen A. Kent, Ronald C. Desrosiers

Neuroscience, Cell Biology & Physiology Faculty Publications

The determinants of immune recognition by five monoclonal antibodies (KK5, KK9, KK17, Senv7.1, and Senv101.1) that neutralize simian immunodeficiency virus infectivity were analyzed. These five neutralizing monoclonal antibodies were generated to native SIVmac251 envelope glycoprotein expressed by a vaccinia virus recombinant vector. All five recognize conformational or discontinuous epitopes and require native antigen for optimal recognition. These monoclonal antibodies also recognize SIVmac239 gp120, but they do not recognize gp120 of two natural variants of SIVmac239, 1-12 and 8-22, which evolved during the course of persistent infection in vivo (D.P.W. Burns and R.C. Desrosiers, J. Virol. 65:1843-1854, 1991). Recombinant viruses which …


Peculiar Histopathological Features Of Giardiasis In Distal Duodenal Biopsies, Z Abbas, A A. Qureshi, H Sheikh, S M. Jafri, A H. Khan Sep 1994

Peculiar Histopathological Features Of Giardiasis In Distal Duodenal Biopsies, Z Abbas, A A. Qureshi, H Sheikh, S M. Jafri, A H. Khan

Department of Pathology and Laboratory Medicine

Histological changes in 20 Giardia positive duodenal biopsies (Group A) were compared with 50, Giardia negative duodenal biopsies (Group B), taken during the same period. Stool examinations in Group B were negative for Giardia. Surface epithelium, villous and crypt architecture and cellular infiltrates were examined and compared between the groups. Atrophic changes in the villi were more common in Group A as compared to B(P < 0.0001). Intraepithelial neutrophil infiltration (P < 0.001), infiltration of the lamina propria with plasma cells (P < 0.5), and presence of eosinophils in the lamina propria (P < 0.001) were significant findings in group A. Some of the changes were related to the density of Giardia colonization e.g., the goblet cell depletion (P < 0.05) and the density of plasma cell infiltration in lamina propria (P < 0.01). Erosions and ulcerations were less commonly seen in group A. Thus we conclude that giardiasis manifests its peculiar features in the distal duodenal mucosa and a biopsy of this region is an important diagnostic tool for detection of this disease.


A Randomized Comparison Of Coronary-Stent Placement And Balloon Angioplasty In The Treatment Of Coronary Artery Disease. Stent Restenosis Study Investigators., David L. Fischman, Martin B. Leon, Donald S. Baim, Richard A. Schatz, Michael P. Savage, Ian Penn, Katherine Detre, Lisa Veltri, Donald Ricci, Masakiyo Nobuyoshi, Michael Cleman, Richard Heuser, David Almond, Paul S. Teirstein, R. David Fish, Antonio Colombo, Jeffrey Brinker, Jeffrey Moses, Alex Shaknovich, John Hirshfeld, Stephen Bailey, Stephen Ellis, Randal Rake, Sheldon Goldberg Aug 1994

A Randomized Comparison Of Coronary-Stent Placement And Balloon Angioplasty In The Treatment Of Coronary Artery Disease. Stent Restenosis Study Investigators., David L. Fischman, Martin B. Leon, Donald S. Baim, Richard A. Schatz, Michael P. Savage, Ian Penn, Katherine Detre, Lisa Veltri, Donald Ricci, Masakiyo Nobuyoshi, Michael Cleman, Richard Heuser, David Almond, Paul S. Teirstein, R. David Fish, Antonio Colombo, Jeffrey Brinker, Jeffrey Moses, Alex Shaknovich, John Hirshfeld, Stephen Bailey, Stephen Ellis, Randal Rake, Sheldon Goldberg

Department of Medicine Faculty Papers

BACKGROUND: Coronary-stent placement is a new technique in which a balloon-expandable, stainless-steel, slotted tube is implanted at the site of a coronary stenosis. The purpose of this study was to compare the effects of stent placement and standard balloon angioplasty on angiographically detected restenosis and clinical outcomes.

METHODS: We randomly assigned 410 patients with symptomatic coronary disease to elective placement of a Palmaz-Schatz stent or to standard balloon angioplasty. Coronary angiography was performed at base line, immediately after the procedure, and six months later.

RESULTS: The patients who underwent stenting had a higher rate of procedural success than those who …


Molecular Cloning And Expression Of A Unique Receptor-Like Protein-Tyrosine-Phosphatase In The Leucocyte-Common-Antigen-Related Phosphatase Family, Wei-Ren Zhang, Naotake Hashimoto, Faiyaz Ahmad, Wendi Ding, Barry J. Goldstein Aug 1994

Molecular Cloning And Expression Of A Unique Receptor-Like Protein-Tyrosine-Phosphatase In The Leucocyte-Common-Antigen-Related Phosphatase Family, Wei-Ren Zhang, Naotake Hashimoto, Faiyaz Ahmad, Wendi Ding, Barry J. Goldstein

Department of Medicine Faculty Papers

Protein-tyrosine-phosphatases (PTPases) have been implicated in the regulation of certain tyrosine kinase growth factor receptors in that they dephosphorylate the activated (autophosphorylated) form of the receptors. In order to identify PTPases that potentially act on receptor targets in liver, we used the human leucocyte common antigen-related PTPase (LAR) cDNA [Streuli, Krueger, Hall, Schlossman and Saito (1988) J. Exp. Med. 168, 1523-1530] and isolated two closely related transmembrane PTPase homologues from a rat hepatic cDNA library. Both PTPases had large extracellular domains that contained three immunoglobulin-like repeats and eight type-III fibronectin repeats. Both enzymes had tandem homologous PTPase domains following a …


The Role Of Cd8+T Cells In The Immune Response To Trypanosoma Cruzi In Mice Held At Elevated Environmental Temperature, Zhijan Ming Aug 1994

The Role Of Cd8+T Cells In The Immune Response To Trypanosoma Cruzi In Mice Held At Elevated Environmental Temperature, Zhijan Ming

Masters Theses & Specialist Projects

When maintained at 36°C, T. cruzi infected C3H mice survive an infection that is lethal to mice maintained at room temperature. To study the role of CD8+ T cells in this phenomenon, anti-CD8 monoclonal antibody (MAb) was used to deplete CD8+ T cells in vivo. An IgG2a-producing rat hybridoma (designated 53-6.72) was adapted to serum free medium, and anti-CD8 MAb was purified from culture supernatant by ammonium sulfate precipitation. Mice were injected intraperitoneally with 200(ig of MAb for three consecutive days. On the fifth day, the result of the in vivo depletion of CD8+ T cells was determined by an …


External Locus Of Control And Negative Life Experiences In Persons With Chronic Fatigue And Immune Dysfunction Syndrome, Pamela Thomas Priebe Aug 1994

External Locus Of Control And Negative Life Experiences In Persons With Chronic Fatigue And Immune Dysfunction Syndrome, Pamela Thomas Priebe

Student Dissertations & Theses

A review of related literature indicated a person's perception of negative life experiences may be unusually high prior to the onset of an illness. An external locus of control belief system may also be present prior to the onset of an illness. The present study used the Life Experiences Survey measure to compare the perception of life experiences of a group of people with CFIDS and a group of people without CFIDS. The present study also used the Locus of Control Scale to measure the locus of control belief system for the same two groups of people. The results of …


A Thyroid Hormone-Regulated Gene In Xenopus Laevis Encodes A Type Iii Iodothyronine 5-Deiodinase., Donald L. St Germain, Robert Schwartzman, Walburga Croteau, Akira Kanamori, Zhou Wang, Donald D. Brown, Valerie Galton Aug 1994

A Thyroid Hormone-Regulated Gene In Xenopus Laevis Encodes A Type Iii Iodothyronine 5-Deiodinase., Donald L. St Germain, Robert Schwartzman, Walburga Croteau, Akira Kanamori, Zhou Wang, Donald D. Brown, Valerie Galton

Dartmouth Scholarship

The type III iodothyronine 5-deiodinase metabolizes thyroxine and 3,5,3'-triiodothyronine to inactive metabolites by catalyzing the removal of iodine from the inner ring. The enzyme is expressed in a tissue-specific pattern during particular stages of development in amphibia, birds, and mammals. Recently, a PCR-based subtractive hybridization technique has been used to isolate cDNAs prepared from Xenopus laevis tadpole tail mRNA that represent genes upregulated by thyroid hormone during metamorphosis. Sequence analysis of one of these cDNAs (XL-15) revealed regions of homology to the mRNA encoding the rat type I (outer ring) 5'-deiodinase, including a conserved UGA codon that encodes selenocysteine in …


Comparison Of Micrscan Identification And Susceptibility Testing Methods For Streptococcus Dysgalactiae To Conventional Biochemical Reactions And Kirby-Bauer Susceptibility Testing Methods, Anthony Hatcher Aug 1994

Comparison Of Micrscan Identification And Susceptibility Testing Methods For Streptococcus Dysgalactiae To Conventional Biochemical Reactions And Kirby-Bauer Susceptibility Testing Methods, Anthony Hatcher

Masters Theses & Specialist Projects

A total of 100 isolates of Streptococcus dysgalact iae from bovine mastitis infections was used to evaluate and compare the biochemical reactions of the gram positive Combo Type 6 panel on the MicroScan autoSCANR system to a conventional procedure for identification of streptococci. Of the 100 isolates, 83.3% was identified as "Very Rare Biotype" by the MicroScan and classified as S. dysgalactiae by conventional methods. Of the remaining 16.7%, MicroScan identified 3.3% as Streptococcus morbillorum, 3.3% as Aerococcus viridians, 3.3% as Streptococcus constellatum/milleri, 1.7% as Streptococcus agalactiae, 1.7% as Streptococcus mitis, 1.7% as Streptococcus sanguis, and 1.7% as Streptococcus intermidis/rni …


The Role Of Cd4+T Cells In The Immune Response To Trypanosoma Cruzi In Mice Held At Elevated Environmental Temperature, Qi Guo Aug 1994

The Role Of Cd4+T Cells In The Immune Response To Trypanosoma Cruzi In Mice Held At Elevated Environmental Temperature, Qi Guo

Masters Theses & Specialist Projects

The immune response of mice infected with Trypanosoma cruzi (the causative agent of Chagas' disease) has been extensively studied, and it has been demonstrated that changes in environmental temperature can influence the resistance of infected mice to the parasite. In particular, several investigators have demonstrated an increased resistance to T. cruzi infection when infected mice are maintained at 36°C. This increased resistance is reflected in decreased parasitemias and increased longevity. In addition, this enhanced resistance has been shown to be an immunological phenomenon. CD4+ T cells play a very important role in immune responses to parasitic infections through the secretion …


Impairment Of The Cellular Immune Response In Acute Murine Toxoplasmosis: Regulation Of Interleukin 2 Production And Macrophage-Mediated Inhibitory Effects., Sakhina Haque, Imtiaz Khan, Azizul Haque, Lloyd Kasper Jul 1994

Impairment Of The Cellular Immune Response In Acute Murine Toxoplasmosis: Regulation Of Interleukin 2 Production And Macrophage-Mediated Inhibitory Effects., Sakhina Haque, Imtiaz Khan, Azizul Haque, Lloyd Kasper

Dartmouth Scholarship

Depression of the cellular immune response to Toxoplasma gondii has been reported in both mice and humans. The present study was undertaken to determine the kinetics and mechanism of the observed downregulation of interleukin 2 (IL-2) production during experimental murine toxoplasmosis. For these investigations, the cell-mediated immune response to the wild type (PTg) was compared with that to the less-virulent mutant parasite (PTgB), which is deficient in the major surface antigen, p30 (SAG-1). Spleen cells from infected A/J mice failed to proliferate in response to Toxoplasma antigens during the first week of infection. Both PTg- and PTgB-infected A/J mice exhibited …


Adoptive Transfer Of Polyclonal And Cloned Cytolytic T Lymphocytes (Ctl) Specific For Mouse Aids-Associated Tumors Is Effective In Preserving Ctl Responses: A Measure Of Protection Against Lp-Bm5 Retrovirus-Induced Immunodeficiency., William R. Green, Kathy A. Green, Karen M. Crassi Jul 1994

Adoptive Transfer Of Polyclonal And Cloned Cytolytic T Lymphocytes (Ctl) Specific For Mouse Aids-Associated Tumors Is Effective In Preserving Ctl Responses: A Measure Of Protection Against Lp-Bm5 Retrovirus-Induced Immunodeficiency., William R. Green, Kathy A. Green, Karen M. Crassi

Dartmouth Scholarship

Cytolytic T lymphocytes (CTL) can be raised against C57BL/6 B-cell lymphomas from mice with LP-BM5 murine leukemia virus-induced AIDS (MAIDS). Adoptive transfer of polyclonal anti-MAIDS tumor CTL or two CTL clones specific for the B6-1710 MAIDS lymphoma caused preservation of major histocompatibility complex-restricted and allogeneic CTL responses, which may be interpreted as indices of protection from LP-BM5 murine leukemia virus-induced immunodeficiency.


Polyclonal Infections Due To Mycobacterium Avium Complex In Patients With Aids Detected By Pulsed-Field Gel Electrophoresis Of Sequential Clinical Isolates., Alexander M. Slutsky, Robert D. Arbeit, Thomas W. Barber, Josiah Rich, C Fordham Von Reyn Jul 1994

Polyclonal Infections Due To Mycobacterium Avium Complex In Patients With Aids Detected By Pulsed-Field Gel Electrophoresis Of Sequential Clinical Isolates., Alexander M. Slutsky, Robert D. Arbeit, Thomas W. Barber, Josiah Rich, C Fordham Von Reyn

Dartmouth Scholarship

Invasive infection with organisms of the Mycobacterium avium complex (MAC) is common among patients with advanced human immunodeficiency virus infection. In previous studies, we analyzed multiple individual colonies of MAC isolated from specimens obtained at the same time and observed that 14 to 20% of patients are simultaneously infected with more than one strain. In this study, we examined sequential isolates from 12 patients with AIDS who had two or more MAC isolates available from clinical specimens collected more than 1 week apart; the intervals between the first and last specimens ranged from 8 to 192 (median, 46) days. For …


High Rates Of Frameshift Mutations Within Homo-Oligomeric Runs During A Single Cycle Of Retroviral Replication, Dawn P. Wooley, H. M. Temin Jul 1994

High Rates Of Frameshift Mutations Within Homo-Oligomeric Runs During A Single Cycle Of Retroviral Replication, Dawn P. Wooley, H. M. Temin

Neuroscience, Cell Biology & Physiology Faculty Publications

Homo-oligomeric runs were inserted into a spleen necrosis virus-based retrovirus vector to determine the nature and rate of mutations within runs of 10 to 12 identical nucleotides during a single replication cycle. Clones of helper cells containing integrated copies of retroviral vectors were used to produce virus for infection of target (nonhelper) cells. Proviral sequences from target cell clones were compared with proviral sequences from helper cell clones to study mutations that occurred during a single cycle of replication. In addition to the internal region spanning the homo-oligomeric inserts, a naturally occurring run of 10 T's in the long terminal …


Determination Of Pancreatic And Salivary Amylase By Enzyme Immunoassay And Their Prevalence In Hyperamylasemic Patients, Sabdra Borgens Ward Jul 1994

Determination Of Pancreatic And Salivary Amylase By Enzyme Immunoassay And Their Prevalence In Hyperamylasemic Patients, Sabdra Borgens Ward

Theses and Dissertations in Biomedical Sciences

Currently, amylase determinations are nonspecific for the organ source and are based entirely on the enzymatic properties of amylase to produce a measurable product or byproduct. The determination of pancreatic amylase is important in the diagnosis of acute pancreatitis. Most commercially available tests for amylase employ the measurement of the change in NADH absorbance at 280 nm or of the p-nitrophenol released from a maltotetrose substrate. These are nonspecific measurements of pancreatic amylase and often necessitate other tests to be run such as a serum lipase.

The two predominant isoenzymes of amylase are pancreatic (p-amylase) and salivary (s-amylase); the most …


Evaluation And Comparison Of Environmental Contaminants Present In Two Types Of Swine Rearing Facilities, Carolyn Crowe Jul 1994

Evaluation And Comparison Of Environmental Contaminants Present In Two Types Of Swine Rearing Facilities, Carolyn Crowe

Masters Theses & Specialist Projects

It has been reported that pigs weaned and moved into an isolated nursery have greater growth rates measured on an average daily gain, and thymus gland weights than do their counterparts in a conventional nursery. In this study I explored the association of this biological difference with environmental contaminants. Levels of total and respirable dust and endotoxin, carbon monoxide, carbon dioxide, ammonia, and temperature and percent relative humidity were measured in two types of swine rearing facilities: isolated nursery and nursery within a conventional farm. We found isolated nurseries have significantly (p<0.05) less total and respirable dust and endotoxin and greater growth rates. With few exceptions, our measurements of levels of total and respirable dust and total endotoxin were within published ranges. Levels of respirable endotoxin were higher than published ranges.


Cerebral Microcirculatory Effects Of Maturation, Scott R. Elliott Jun 1994

Cerebral Microcirculatory Effects Of Maturation, Scott R. Elliott

Loma Linda University Electronic Theses, Dissertations & Projects

The present studies demonstrate that in the second (2B) and fourth (4B) branches of newborn and adult sheep middle cerebral arteries, 5-HT2 serotonergic receptors mediate contractile responses to serotonin and that alpha-1 adrenergic receptors mediate contractile responses to norepinephrine. In addition, tissue sensitivity to 5-HT and NE decreases significantly with maturation, but does not vary with branch order. These age-related changes were associated with a decrease in affinity and maximum response in 2B and 4B segments of 5-HT and NE contracted arteries, respectively. Norepinephrine and 5-HT occupancy at the pD2 rose significantly in 2B segments, but did not change …


The Cost Of Arm Autotomy In The Starfish Stichaster-Striatus, John M. Lawrence, A. Larrain Jun 1994

The Cost Of Arm Autotomy In The Starfish Stichaster-Striatus, John M. Lawrence, A. Larrain

Integrative Biology Faculty and Staff Publications

Arm autotomy in asteroids, as tail autotomy in vertebrates, typically occurs when the animal is attacked and appears to facilitate escape. One assumes autotomy has a cost, but it rarely has been demonstrated in the field in vertebrates and never demonstrated in asteroids. The concentration of lipid was 40 % less and the amount of kilojoules 85 % less in the pyloric caeca of the asteroid Stichaster striatus Muller & Troschel (Echinodermata: Asteroidea) with autotomized arms than in those of individuals with intact arms collected in the field. as the pyloric caeca are used as nutrient reserves, individuals with autotomized …


Comparative Toxicities Of Aminonitriles, Timothy Lester Lacy Jun 1994

Comparative Toxicities Of Aminonitriles, Timothy Lester Lacy

Theses and Dissertations - UTB/UTPA

This study examined the comparative toxicities and metabolism of four selected aminonitriles namely aminoacetonitrile, $\beta$-aminopropionitrile, $N,N\sp\prime$-dimethylaminopropionitrile, and $\beta ,\beta\sp\prime$-iminodipropionitrile. Various experiments in this study include time course of the metabolism of these nitriles to cyanide, thiocyanate, and cyanoacetic acid. All of the nitriles studied were metabolized to cyanide and thiocyanate and the levels of these metabolites remained at a significantly high level even 5 days after dosing. Except aminoacetonitrile all the nitriles were metabolized to cyanoacetic acid. Experiments on the role of vehicles on the toxicity and metabolism of nitriles showed that all of the vehicles studied significantly affected nitrile …


Signal Transduction In Bacterial Chemotaxis, Edward Heath Rowsell Jun 1994

Signal Transduction In Bacterial Chemotaxis, Edward Heath Rowsell

Loma Linda University Electronic Theses, Dissertations & Projects

This study investigated the site of ATP utilization in the signal transduction pathway of bacterial chemotaxis and localized the point of convergence of a methylation-independent system of chemotaxis with the methylation-dependent system. The identity of the signal originating from the phosphotransferase system was investigated by substituting the fructose-inducible HPr-like protein FPr for HPr in transport and chemotaxis. In addition, a novel chemoattractant, glycerol, was identified for Salmonella typhimurium. Histidine-auxotrophic S. typhimurium strains ST23 (hisF) and ST171 (hisF cheB) were depleted for ATP. The times required for the bacteria to adapt to a step increase in serine, …


Comparison Of Cytotoxic Properties Of Neonatal And Adult Neutrophils And Monocytes And Enhancement By Cytokines., E . R. Stiehm, R. L. Roberts, B. J. Ank, S. Plaeger-Marshall, N. Salman, L. Shen, M. W. Fanger May 1994

Comparison Of Cytotoxic Properties Of Neonatal And Adult Neutrophils And Monocytes And Enhancement By Cytokines., E . R. Stiehm, R. L. Roberts, B. J. Ank, S. Plaeger-Marshall, N. Salman, L. Shen, M. W. Fanger

Dartmouth Scholarship

We studied cytotoxic capabilities of newborn polymorphonuclear leukocytes (PMNs) and monocytes and their enhancement by cytokines and antibodies. Umbilical cord PMNs were assessed for their ability to kill various target cells spontaneously, after activation with phorbol myristate acetate, in the presence of antiserum (antibody-dependent cellular cytotoxicity), and in the presence of dually specific antibody (heteroantibody-mediated cytotoxicity). Target cells included the K562 cell line (natural killer cell target), chicken erythrocytes (CRBCs), and herpes simplex virus-infected CEM cell lines. Newborn PMNs were equivalent to adult PMNs in their cytotoxic capacity in several cytotoxicity assays. Neither adult nor newborn PMNs lyse tumor cell …


Subunit Dynamics In Escherichia Coli Preprotein Translocase., John C. Joly, Marilyn R. Leonard, William T. Wickner May 1994

Subunit Dynamics In Escherichia Coli Preprotein Translocase., John C. Joly, Marilyn R. Leonard, William T. Wickner

Dartmouth Scholarship

SecY, SecE, and band 1 copurify as the SecY/E integral membrane domain of Escherichia coli preprotein translocase. To measure the in vivo association of these polypeptides and assay possible exchange, plasmid-borne secY and secE genes were placed under control of the ara regulon and fused to DNA encoding the influenza hemagglutinin epitope. Cells were incubated with [35S]methionine, grown for a "chase" period, and then induced with arabinose to express epitope-tagged, nonradioactive SecY and SecE. Both the wild-type and epitope-tagged polypeptides assembled into functional, heterotrimeric SecY/E complex. However, immunoprecipitation with antibody to the epitope tag did not cross-precipitate radiolabeled SecY or …


Interleukin-12 Enhances Murine Survival Against Acute Toxoplasmosis., Imtiaz A. Khan, Tadashi Matsuura, Lloyd H. Kasper May 1994

Interleukin-12 Enhances Murine Survival Against Acute Toxoplasmosis., Imtiaz A. Khan, Tadashi Matsuura, Lloyd H. Kasper

Dartmouth Scholarship

Protective immunity against Toxoplasma gondii is mediated by the host cellular immune response. Interleukin-12 (IL-12), a recently described cytokine that stimulates NK cells to produce gamma interferon (IFN-gamma), is able to enhance host protection against this parasite in SCID mice. Administration of IL-12 to A/J mice significantly increased survival over that of control mice when IL-12 was delivered early in the course of acute infection. If it was administered at day 3 or thereafter, there was no observed difference in mortality between treated and control mice. Antibody depletion of IL-12 increased susceptibility to infection, as measured by mortality, only when …