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Articles 7861 - 7890 of 7931

Full-Text Articles in Medicine and Health Sciences

Possible Roles Of Insulin And Insulin-Like Growth Factors In Rat Preimplantation Development: Investigation Of Gene Expression By Reverse Transcription-Polymerase Chain Reaction., X Zhang, G M Kidder, A J Watson, G A Schultz, D T Armstrong Mar 1994

Possible Roles Of Insulin And Insulin-Like Growth Factors In Rat Preimplantation Development: Investigation Of Gene Expression By Reverse Transcription-Polymerase Chain Reaction., X Zhang, G M Kidder, A J Watson, G A Schultz, D T Armstrong

Obstetrics & Gynaecology Publications

The sensitive mRNA phenotyping technique of reverse transcription-polymerase chain reaction was used to demonstrate that insulin receptor mRNA is present in rat embryos during the preimplantation period. In addition, mRNA encoding insulin-like growth factor (IGF) type I and type II receptors have also been detected in rat preimplantation embryos. IGF-I mRNA was not detected in preimplantation embryos but was found in oviducts and uteri of prepubertal and early pregnant rats. IGF-II mRNA was present in both embryos and in oviducts and uteri during the preimplantation period. These findings suggest that insulin and IGF-I could influence early embryo development in endocrine …

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Enhanced Renal Sympathetic And Cardiovascular Responses To Substance P In Hypertension, Gregory W. Lindsay Dec 1993

Enhanced Renal Sympathetic And Cardiovascular Responses To Substance P In Hypertension, Gregory W. Lindsay

Electronic Theses and Dissertations

Blood pressure, heart rate, and renal sympathetic nerve responses were measured in 9-13 week old male spontaneously hypertensive rats (SHR) and compared to those in age and sex-matched Wistar-Kyoto (WKY) rats following intravenous injection of the neuropeptide substance P (SP), the nicotinic stimulant 1,1-dimethyl-4-phenylpiperazinium (DMPP), and the adrenoceptor stimulant norepinephrine (NE). Charles River Sprague-Dawley (CD) rats were used in some studies to develop methodologies. Measurements were made in control rats and also following sinoaortic denervation, pithing, ganglion blockade, or adrenoceptor blockade. Responses were evaluated in order to determine if ganglion stimulation by SP was enhanced in SHR compared to WKY …

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Induction Of Protective Immunity Against Larval Onchocerca Volvulus In A Mouse Model., A. M. Lange, W. Yutanawiboonchai, J. B. Lok, M. Trpis, D. Abraham Dec 1993

Induction Of Protective Immunity Against Larval Onchocerca Volvulus In A Mouse Model., A. M. Lange, W. Yutanawiboonchai, J. B. Lok, M. Trpis, D. Abraham

Department of Microbiology and Immunology Faculty Papers

BALB/cBYJ mice were immunized against larval Onchocerca volvulus by subcutaneous injection of normal, irradiated, or freeze-thaw-killed Onchocerca sp. larvae. The mice received challenge infections of O. volvulus third-stage larva (L3) contained in diffusion chambers implanted subcutaneously. At two-weeks postinfection, the diffusion chambers were removed and larval survival was assessed. When mice were immunized a single time with 35-krad-irradiated or normal O. volvulus L3, there was a significant reduction in the survival of challenge parasites. However, there was little or no reduction in challenge worm survival when mice were immunized a single time with freeze-thaw-killed O. volvulus L3 or fourth-stage larva …

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Reversal Of Age-Associated Decline In Immune Response To Pnu-Imune Vaccine By Supplementation With The Steroid Hormone Dehydroepiandrosterone, Manju Garg, Subbarao Bondada May 1993

Reversal Of Age-Associated Decline In Immune Response To Pnu-Imune Vaccine By Supplementation With The Steroid Hormone Dehydroepiandrosterone, Manju Garg, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

Recently, we reported that murine antibody responses to the 23-valent pneumococcal polysaccharide (Pnu-Imune) vaccine declined with age. Here we present data to support the concept that age-associated immune defects are not only due to intrinsic defects in immune cells but are also due to extrinsic factors emanating from the neuroendocrine system. We found that supplementation with dehydroepiandrosterone, a steroid hormone known to be reduced in the aged, corrects the immune deficiency of aged mice and significantly enhanced their splenic immune responses to the Pnu-Imune vaccine.

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The Tight Skin Mouse: Demonstration Of Mutant Fibrillin-1 Production And Assembly Into Abnormal Microfibrils, Cay M. Kielty, Michael Raghunath, Linda D. Siracusa, Michael J. Sherratt, Reiner Peters, C. Adrian Shuttleworth, Sergio A. Jimenez Mar 1993

The Tight Skin Mouse: Demonstration Of Mutant Fibrillin-1 Production And Assembly Into Abnormal Microfibrils, Cay M. Kielty, Michael Raghunath, Linda D. Siracusa, Michael J. Sherratt, Reiner Peters, C. Adrian Shuttleworth, Sergio A. Jimenez

Selected Works of Sergio Jiménez, MD, MACR

Mice carrying the Tight skin (Tsk) mutation harbor a genomic duplication within the fibrillin-1 (Fbn 1) gene that results in a larger than normal in-frame Fbn 1 transcript. In this study, the consequences of the Tsk mutation for fibrillin-containing microfibrils have been examined. Dermal fibroblasts from Tsk/+ mice synthesized and secreted both normal fibrillin (approximately 330 kD) and the mutant oversized Tsk fibrillin-1 (approximately 450 kD) in comparable amounts, and Tsk fibrillin-1 was stably incorporated into cell layers. Immunohistochemical and ultrastructural analyses of normal and Tsk/+ mouse skin highlighted differences in the gross organization and distribution of microfibrillar arrays. Rotary …

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How To Make A Blastocyst., A J Watson, G M Kidder, G A Schultz Oct 1992

How To Make A Blastocyst., A J Watson, G M Kidder, G A Schultz

Obstetrics & Gynaecology Publications

Several of the new reproductive technologies have been cultivated from our current understanding of the genetic programming and cellular processes that are involved in the major morphogenetic events of mammalian preimplantation development. Research directed at characterizing the patterns of gene expression during early development has shown that the embryo is initially under maternal control and later superseded by new transcriptional activity provided by the activation of the embryonic genome. Several embryonic transcripts encoding: (i) growth factors, (ii) cell junctions, (iii) plasma membrane ion transporters, and (iv) cell adhesion molecules have been identified as contributing directly to the progression of the …

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Changes In Intracellular Chloride During Osmotic Stress And L-Alanine Uptake In Mouse Hepatocytes, Kening Wang Oct 1992

Changes In Intracellular Chloride During Osmotic Stress And L-Alanine Uptake In Mouse Hepatocytes, Kening Wang

Electronic Theses and Dissertations

A stable intracellular ionic environment is necessary for hepatocytes to function normally. Thus, during hypotonic shock or L-alanine uptake, hepatocytes swell and then exhibit a regulatory volume decrease (RVD), which comprises an increase in K$\sp+$ conductance (G$\sb{\rm K}$), an increased K$\sp+$ efflux, and a hyperpolarization of transmembrane potential (V$\sb{\rm m}$). Since hepatocyte intracellular Cl$\sp-$ has been demonstrated to distribute passively with V$\sb{\rm m}$, this study is designed to test the hypothesis that the hypotonic shock- or L-alanine uptake-induced hyperpolarization of V$\sb{\rm m}$ might provide an electromotive force for the efflux of hepatocyte intracellular Cl$\sp-$, which in turn would contribute osmotically …

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On The Mechanism Of Parathyroid Hormone Stimulation Of Calcium Uptake By Mouse Distal Convoluted Tubule Cells, F A. Gesek, A. Friedman Sep 1992

On The Mechanism Of Parathyroid Hormone Stimulation Of Calcium Uptake By Mouse Distal Convoluted Tubule Cells, F A. Gesek, A. Friedman

Dartmouth Scholarship

PTH stimulates transcellular Ca2+ absorption in renal distal convoluted tubules. The effect of PTH on membrane voltage, the ionic basis of the change in voltage, and the relations between voltage and calcium entry were determined on immortalized mouse distal convoluted tubule cells. PTH (10(-8) M) significantly increased 45Ca2+ uptake from basal levels of 2.81 +/- 0.16 to 3.88 +/- 0.19 nmol min-1 mg protein-1. PTH-induced 45Ca2+ uptake was abolished by the dihydropyridine antagonist, nifedipine (10(-5) M). PTH did not affect 22Na+ uptake. Intracellular calcium activity ([Ca2+]i) was measured in cells loaded with fura-2. Control [Ca2+]i averaged 112 +/- 21 nM. …

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Mechanism Of Calcium Transport Stimulated By Chlorothiazide In Mouse Distal Convoluted Tubule Cells., Frank A. Gesek, Peter A. Friedman Aug 1992

Mechanism Of Calcium Transport Stimulated By Chlorothiazide In Mouse Distal Convoluted Tubule Cells., Frank A. Gesek, Peter A. Friedman

Dartmouth Scholarship

Thiazide diuretics inhibit Na+ and stimulate Ca2+ absorption in renal distal convoluted tubules. Experiments were performed on immortalized mouse distal convoluted tubule (MDCT) cells to determine the mechanism underlying the dissociation of sodium from calcium transport and the stimulation of calcium absorption induced by thiazide diuretics. Control rates of 22Na+ uptake averaged 272 +/- 35 nmol min-1 mg protein-1 and were inhibited 40% by chlorothiazide (CTZ, 10(-4) M). Control rates of 36Cl- uptake averaged 340 +/- 50 nmol min-1 mg protein-1 and were inhibited 50% by CTZ. CTZ stimulated 45Ca2+ uptake by 45% from resting levels of 2.86 +/- 0.26 …

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Immune Responses Of Systemic And Mucosal Lymphoid Organs To Pnu-Imune Vaccine As A Function Of Age And The Efficacy Of Monophosphoryl Lipid A As An Adjuvant, Manju Garg, Subbarao Bondada Jun 1992

Immune Responses Of Systemic And Mucosal Lymphoid Organs To Pnu-Imune Vaccine As A Function Of Age And The Efficacy Of Monophosphoryl Lipid A As An Adjuvant, Manju Garg, Subbarao Bondada

Microbiology, Immunology, and Molecular Genetics Faculty Publications

A murine model system was established to study immune responses to the Pnu-Imune vaccine, which is made up of 23 different pneumococcal capsular polysaccharides. In this animal model, antibody-forming cell responses to 21 of 23 individual polysaccharides in the vaccine were detected. The Pnu-Imune vaccine elicited good antibody responses from the spleens and mesenteric lymph nodes (MLN) of young mice, whereas a variety of other peripheral lymph nodes were unresponsive. The immunoglobulin M plaque-forming cell (PFC) response in the spleen to the Pnu-Imune vaccine (given intraperitoneally or subcutaneously) decreased dramatically with increasing age. However, the spleen and MLN differed in …

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Differentiation Of Renal Beta-Intercalated Cells To Alpha-Intercalated And Principal Cells In Culture., Geza Fejes-Tóth, Aniko Náray-Fejes-Tóth Jun 1992

Differentiation Of Renal Beta-Intercalated Cells To Alpha-Intercalated And Principal Cells In Culture., Geza Fejes-Tóth, Aniko Náray-Fejes-Tóth

Dartmouth Scholarship

The renal collecting duct is a heterogenous epithelium consisting of intercalated cells (ICC) and principal cells (PC). The origin of this cellular heterogeneity is not clear. To test the hypothesis that the two cell types might originate from one another, pure populations of ICC (beta subtype) and PC were isolated by fluorescence-activated cell sorting and grown on permeable supports. After the monolayers reached confluence, the expression of ICC- and PC-specific functions and antigens was monitored. Cultures of sorted beta-ICC, in addition to expressing ICC-specific functions (such as an electrogenic H+ secretion) and antigens, progressively acquired PC functions (amiloride-sensitive Na+ transport …

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Differential Regulation Of Collagenase Gene Expression By Retinoic Acid Receptors--Alpha, Beta And Gamma, Luying Pan, Stephen H. Chamberlain, David T. Auble, Constance E. Brinckerhoff Jun 1992

Differential Regulation Of Collagenase Gene Expression By Retinoic Acid Receptors--Alpha, Beta And Gamma, Luying Pan, Stephen H. Chamberlain, David T. Auble, Constance E. Brinckerhoff

Dartmouth Scholarship

The mechanisms involved in retinoic acid (RA)-mediated regulation of the collagenase gene in a rabbit synovial fibroblast cell line (HIG82) were investigated. When HIG82 cells are cotransfected with expression vectors containing cDNAs for retinoic acid receptor (RAR) α1, β2, or γ1 and collagenase promoter-driven CAT reporter constructs, only RAR-γ1 represses basal CAT expression upon RA treatment, while RAR-α1, β2, and γ1 all suppress phorbol-induced CAT expression. Thus, transcriptional regulation of collagenase by RA is mediated by RARs in an RAR-type specific manner. Using mutatlonal and deletional analysis, we find that interaction between elements within 182 bp collagenase promoter plays an …

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Transformation Of A Continuous Rat Embryo Fibroblast Cell Line Requires Three Separate Domains Of Simian Virus 40 Large T Antigen., Jiyue Zhu, Philip W. Rice, Lisa Gorsch, Marina Abate, Charles N. Cole May 1992

Transformation Of A Continuous Rat Embryo Fibroblast Cell Line Requires Three Separate Domains Of Simian Virus 40 Large T Antigen., Jiyue Zhu, Philip W. Rice, Lisa Gorsch, Marina Abate, Charles N. Cole

Dartmouth Scholarship

Mouse C3H 10T1/2 cells and the established rat embryo fibroblast cell line REF-52 are two cell lines widely used in studies of viral transformation. Studies have shown that transformation of 10T1/2 cells requires only the amino-terminal 121 amino acids of simian virus 40 (SV40) large T antigen, while transformation of REF-52 cells requires considerably more of large T antigen, extending from near the N terminus to beyond residue 600. The ability of a large set of linker insertion, small deletion, and point mutants of SV40 T antigen to transform these two cell lines and to bind p105Rb was determined. Transformation …

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Cytolytic T Lymphocytes Specific For Tumors And Infected Cells From Mice With A Retrovirus-Induced Immunodeficiency Syndrome., Jennifer G. Erbe, Kathy A. Green, Karen M. Crassi, Herbert C. Morse, W R. Green May 1992

Cytolytic T Lymphocytes Specific For Tumors And Infected Cells From Mice With A Retrovirus-Induced Immunodeficiency Syndrome., Jennifer G. Erbe, Kathy A. Green, Karen M. Crassi, Herbert C. Morse, W R. Green

Dartmouth Scholarship

LP-BM5 retrovirus complex-infected C57BL/6 mice develop immunodeficiency, somewhat analogous to AIDS, termed murine AIDS (MAIDS). After secondary stimulation with syngeneic B-cell lymphomas from LP-BM5-infected mice, C57BL/6 mice produced vigorous CD8+ cytotoxic T lymphocytes specific for MAIDS-associated tumors. An anti-LP-BM5 specificity was suggested because spleen and lymph node cells from LP-BM5-infected mice served as target cells in competition assays, and cells from LP-BM5, but not ecotropic, virus-infected mice functioned as secondary in vitro stimulators to generate cytotoxic T lymphocytes to MAIDS tumors.

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Adenosine Regulates A Chloride Channel Via Protein Kinase C And A G Protein In A Rabbit Cortical Collecting Duct Cell Line., Erik M. Schwiebert, Katherine H. Karlson, Peter A. Friedman, Paul Dietl, William S. Spielman, Bruce Stanton Mar 1992

Adenosine Regulates A Chloride Channel Via Protein Kinase C And A G Protein In A Rabbit Cortical Collecting Duct Cell Line., Erik M. Schwiebert, Katherine H. Karlson, Peter A. Friedman, Paul Dietl, William S. Spielman, Bruce Stanton

Dartmouth Scholarship

We examined the regulation by adenosine of a 305-pS chloride (Cl-) channel in the apical membrane of a continuous cell line derived from rabbit cortical collecting duct (RCCT-28A) using the patch clamp technique. Stimulation of A1 adenosine receptors by N6-cyclohexyladenosine (CHA) activated the channel in cell-attached patches. Phorbol 12,13-didecanoate and 1-oleoyl 2-acetylglycerol, activators of protein kinase C (PKC), mimicked the effect of CHA, whereas the PKC inhibitor H7 blocked the action of CHA. Stimulation of A1 adenosine receptors also increased the production of diacylglycerol, an activator of PKC. Exogenous PKC added to the cytoplasmic face of inside-out patches also stimulated …

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The Ethical Judgment Of Animal Research, Shelley L. Galvin, Harold A. Herzog Jan 1992

The Ethical Judgment Of Animal Research, Shelley L. Galvin, Harold A. Herzog

Experimentation Collection

One hundred sixty subjects acted as members of a hypothetical Institutional Animal Care and Use Committee and evaluated five proposals in which animals were to be used for research or educational purposes. They were asked to approve or reject the proposals and to indicate what factors were important in reaching their ethical decisions. Gender and differences in personal moral philosophy were related to approval decisions. The reasons given for the decisions fell into three main categories: metacognitive statements, factors related to the animal, and factors related to the design of the experiment.

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Expression Of A Human Cartilage Procollagen Gene (Col2a1) In Mouse 3t3 Cells., Leena Ala-Kokko, James Hyland, Carol Smith, Kari I. Kivirikko, Sergio A. Jimenez, Darwin J. Prockop Aug 1991

Expression Of A Human Cartilage Procollagen Gene (Col2a1) In Mouse 3t3 Cells., Leena Ala-Kokko, James Hyland, Carol Smith, Kari I. Kivirikko, Sergio A. Jimenez, Darwin J. Prockop

Department of Medicine Faculty Papers

Expression in a recombinant system has been difficult to obtain for any of the major fibrillar collagens that require processing by eight or more post-translational enzymes. Here, two DNA constructs were designed so that the promoter region of the gene for the pro-alpha 1(I) chain of human type I procollagen drove expression of the human type II procollagen gene in mouse NIH 3T3 cells, a culture line that normally synthesizes type I procollagen but not any cartilage-specific protein such as type II procollagen. Both constructs were expressed as both mRNA and protein. In clones expressing the construct at high levels, …

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Electrophysiology, Cell Calcium, And Mechanisms Of Hepatocyte Volume Regulation, Walid E. Khalbuss Aug 1990

Electrophysiology, Cell Calcium, And Mechanisms Of Hepatocyte Volume Regulation, Walid E. Khalbuss

Electronic Theses and Dissertations

The electrophysiologic technique (Reuss, L., Proc. Natl. Acad. Sci. USA 82:6014, 1985) was modified to measure changes in steady-state hepatocyte volume during osmotic stress. Hepatocytes in mouse liver slices were loaded with tetramethylammonium ion (TMA$\sp{+}$) during transient exposure of cells to nystatin. Intracellular TMA$\sp{+}$ activity (a$\sp{\rm i}\sb{\rm TMA}$) was measured with TMA$\sp{+}$-sensitive, double-barreled microelectrodes. Loading hepatocytes with TMA$\sp{+}$ did not change their membrane potential (V$\sb{\rm m}$), and under steady-state conditions a$\sp{\rm i}\sb{\rm TMA}$ remained constant over 4 min in single impalements. Hyperosmotic solutions (50, 100, & 150 mM sucrose added to media) and hyposmotic solutions (sucrose in media reduced by …

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The Growth Of Simian Virus 40 (Sv40) Host Range/Adenovirus Helper Function Mutants In An African Green Monkey Cell Line That Constitutively Expresses The Sv40 Agnoprotein., Terryl P. Stacy, Michele Chamberlain, Susan Carswell, Charles N. Cole Jul 1990

The Growth Of Simian Virus 40 (Sv40) Host Range/Adenovirus Helper Function Mutants In An African Green Monkey Cell Line That Constitutively Expresses The Sv40 Agnoprotein., Terryl P. Stacy, Michele Chamberlain, Susan Carswell, Charles N. Cole

Dartmouth Scholarship

The simian virus 40 T-antigen carboxy-terminal mutants, dlA2459 and dlA2475, are cell line and temperature dependent for growth and plaque formation in monkey kidney cells. Although these mutants did form plaques on BSC-1 cells at 37 degrees C, they were about fivefold less efficient for plaque formation than wild-type simian virus 40. These mutants did not grow in CV-1 cells and did not synthesize agnoprotein in those cells. CV-1 cells which constitutively express the agnoprotein were permissive for mutant plaque formation. However, late mRNAs, virion proteins, and progeny virion yields did not accumulate to wild-type levels during mutant infection of …

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Effect Of Dietary Aluminum Sulfate On Calcium And Phosphorus Metabolism Of Broiler Chicks, Akmed S. Hussein, Austin H. Cantor, Thomas H. Johnson, Robert A. Yokel Jun 1990

Effect Of Dietary Aluminum Sulfate On Calcium And Phosphorus Metabolism Of Broiler Chicks, Akmed S. Hussein, Austin H. Cantor, Thomas H. Johnson, Robert A. Yokel

Animal and Food Sciences Faculty Publications

The effect of dietary aluminum sulfate on Ca and P metabolism was studied using 1-day-oldmale broiler chicks. In Experiment 1, practical diets providing .90% Ca plus .45% available P (Pav), .90% Ca plus .78% Pav, 1.80% Ca plus .45% Pav, or 1.80% Ca plus .90% Pav were fed with 0 or .392% Al as aluminum sulfate for 21 days. The control diet (.90% Caplus .45% Pav) without added A1 was fed to all chicks during Days 22 to 49. In general, Al significantly (Pi), tibia breaking strength, tibia weight, percentage of …

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Relationship Of Dietary Aluminum, Phosphorus, And Calcium To Phosphorus And Calcium Metabolism And Growth Performance Of Broiler Chicks, Akmed S. Hussein, Austin H. Cantor, Thomas H. Johnson, Robert A. Yokel Jun 1990

Relationship Of Dietary Aluminum, Phosphorus, And Calcium To Phosphorus And Calcium Metabolism And Growth Performance Of Broiler Chicks, Akmed S. Hussein, Austin H. Cantor, Thomas H. Johnson, Robert A. Yokel

Animal and Food Sciences Faculty Publications

Dietary treatments providing three levels of added Al (0, .196, or .392%) as aluminum sulfate and of available phosphorus (Pav) (.45, .68, or .78%) in a factorial arrangement were administered to day-old chicks in Experiment 1. Plasma inorganic phosphorus (Pi) was significantly (P < .05) elevated by increasing Pav and was decreased by Al. Body weight gain, feed intake, and the gain:feed ratio at Day 21 were significantly decreased by increased concentrations of Al, but were unaffected by the Pav concentrations. Decreases of 39 and 73% in weight gain and of 34 and 66% in feed intake resulted from feeding …

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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 …

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Murine Gamma Interferon Fails To Inhibit Toxoplasma Gondii Growth In Murine Fibroblasts., Joseph D. Schwartzman, Steven L. Gonias, E R. Pfefferkorn Mar 1990

Murine Gamma Interferon Fails To Inhibit Toxoplasma Gondii Growth In Murine Fibroblasts., Joseph D. Schwartzman, Steven L. Gonias, E R. Pfefferkorn

Dartmouth Scholarship

Although treatment of human macrophages or fibroblasts with human gamma interferon results in the inhibition of intracellular Toxoplasma gondii, murine gamma interferon stimulated only murine macrophages, not murine fibroblasts, to inhibit T. gondii. This species difference may be important in understanding the control of acute and chronic toxoplasmosis.

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The Role Of Calcium Ions In Toxic Cell Injury., John L. Farber Mar 1990

The Role Of Calcium Ions In Toxic Cell Injury., John L. Farber

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

Calcium ions have been increasingly implicated as a mediator of the mechanisms generating lethal cell injury under a variety of pathologic circumstances. An overview of the various roles suggested for such alterations in cellular calcium homeostasis is presented. The central role of plasma membrane damage in the genesis of irreversible cell injury is used to divide the postulated roles for calcium ions into two major mechanisms. On the one hand, calcium ions have been proposed as mediators of the functional consequences of plasma membrane injury. An influx of extracellular calcium ions across a damaged permeability barrier and down a steep …

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Susceptibility Of Hepatic Microcirculation To Reperfusion Injury: A Comparison Of Adult And Suckling Rats., Alan M. Yahanda Md, Facs, C N Paidas, M G Clemens Feb 1990

Susceptibility Of Hepatic Microcirculation To Reperfusion Injury: A Comparison Of Adult And Suckling Rats., Alan M. Yahanda Md, Facs, C N Paidas, M G Clemens

Other Specialties

Primary graft failure and vascular thromboses are frequent complications of liver transplantation, yet the mechanisms responsible remain unclear. Previous work from our laboratory has shown that hepatic reperfusion injury results in damage at the microvessel level. The present study was performed to determine whether an increased susceptibility of immature animals to microvascular injury during reperfusion might be a contributing factor in these complications. Suckling (35 to 50 g) or adult (250 to 400 g) rats were subjected to 30 or 60 minutes of hepatic ischemia to the left and median lobes followed by 90 minutes of reperfusion. Control animals were …

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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 Oct 1989

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 …

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Guanine Nucleotide-Binding Protein, Alpha I-3, Directly Activates A Cation Channel In Rat Renal Inner Medullary Collecting Duct Cells., Douglas B. Light, Dennis A. Ausiello, Bruce A. Stanton Jul 1989

Guanine Nucleotide-Binding Protein, Alpha I-3, Directly Activates A Cation Channel In Rat Renal Inner Medullary Collecting Duct Cells., Douglas B. Light, Dennis A. Ausiello, Bruce A. Stanton

Dartmouth Scholarship

We examined whether GTP binding proteins (G proteins) regulate sodium conducting channels in the apical membrane of renal inner medullary collecting duct (IMCD) cells and thereby modulate sodium absorption. Patch clamp studies were conducted on inside-out patches of the apical membrane of IMCD cells grown in primary culture. Guanosine 5'-triphosphate (GTP) and the nonhydrolyzable GTP analogue, GTP gamma S, which activate G proteins, increased the open probability of the cation channel. In contrast, the nonhydrolyzable GDP analogue, GDP beta S, which decreases G protein activity, inhibited the channel. Pertussis toxin also reduced the open probability of the channel. Addition of …

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Immunity To Larval Brugia Malayi In Balb/C Mice: Protective Immunity And Inhibition Of Larval Development., D. Abraham, R. B. Grieve, J. M. Holy, B. M. Christensen Jun 1989

Immunity To Larval Brugia Malayi In Balb/C Mice: Protective Immunity And Inhibition Of Larval Development., D. Abraham, R. B. Grieve, J. M. Holy, B. M. Christensen

Department of Microbiology and Immunology Faculty Papers

The objective of this study was to analyze the immune response of mice to the larval stages of Brugia malayi. Male BALB/c mice were inoculated with 3 doses of irradiated third-stage larvae (L-3) of B. malayi and were subsequently challenged with L-3 implanted ip within diffusion chambers. After 3 weeks, larvae were recovered to determine their viability, length, and stage of development. A significant reduction in parasite survival was observed in immunized mice. Furthermore, larvae recovered from immunized mice were significantly shorter than larvae recovered from control mice. All larvae recovered from immunized mice were L-3, whereas 96% of larvae …

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Aldosterone Stimulates K Secretion Across Mammalian Colon Independent Of Na Absorption, Gerhard Rechkemmer, Dan R. Halm Jan 1989

Aldosterone Stimulates K Secretion Across Mammalian Colon Independent Of Na Absorption, Gerhard Rechkemmer, Dan R. Halm

Neuroscience, Cell Biology & Physiology Faculty Publications

K transport across guinea pig (Cavia porcellus) distal colon was measured in vitro using isotopically determined unidirectional fluxes. Aldosterone stimulated electrogenic Na absorption, as measured by amiloride-sensitive short-circuit current (Isc), and reduced net K absorption from +2.5 ± 0.2 µEq/cm2 per hr to +0.8 ± 0.3 µEq/cm2 per hr (mean ± SEM). Amiloride addition to the mucosal solution did not enhance net K absorption, as expected if inhibiting active Na absorption would reduce active K secretion as in the distal nephron. The amiloride-insensitive Isc was -1.0 ± 0.2 µEq/cm2 per hr (mean ± SEM) …

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Animal Bite Infections., Joel D. Klein, Md Jan 1989

Animal Bite Infections., Joel D. Klein, Md

Department of Pediatrics Faculty Papers

Animal bites have become alarmingly common and may represent a quiet epidemic. It is estimated that between 1 and 3.5 million animal bites occur annually in the United States. The highest incidence has consistently been in 5-to-14-year-old schoolchildren, who have greater contact with animals, especially house pets, on a daily basis. This article discusses the epidemiology, microbiology, clinical findings and management of animal bites infections.

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