Victor Reyes - Academia.edu (original) (raw)

Papers by Victor Reyes

Research paper thumbnail of Highly restricted distributions of hydrophobic and charged amino acids in longitudinal quadrants of alpha-helices

Highly restricted distributions of hydrophobic and charged amino acids in longitudinal quadrants of alpha-helices

Journal of Biological Chemistry

Research paper thumbnail of Number and placement of hydrophobic residues in a longitudinal strip governs helix formation of peptides in the presence of lipid vesicles

Number and placement of hydrophobic residues in a longitudinal strip governs helix formation of peptides in the presence of lipid vesicles

Journal of Biological Chemistry

Research paper thumbnail of AbsTaylor: upper bounding with inner regions in nonlinear continuous global optimization problems

AbsTaylor: upper bounding with inner regions in nonlinear continuous global optimization problems

Journal of Global Optimization

Research paper thumbnail of A GRASP-based scheme for the set covering problem

A GRASP-based scheme for the set covering problem

Operational Research

Research paper thumbnail of NEIL2 plays a critical role in limiting inflammation and preserving genomic integrity in H. pylori-infected gastric epithelial cells

The accumulation of Helicobacter pylori infection-induced oxidative DNA damage in gastric epithel... more The accumulation of Helicobacter pylori infection-induced oxidative DNA damage in gastric epithelial cells is a risk factor for developing gastric cancer (GC); however, the underlying mechanisms remain poorly understood. Here we report that the suppression of NEIL2, an oxidized base-specific mammalian DNA glycosylase, is one such mechanism via which H. pylori infection may fuel the accumulation of DNA damage during the initiation and progression of GC. Using a combination of cultured cell lines and primary cells, we show that expression of NEIL2 is significantly down-regulated after H. pylori infection; such down-regulation was also seen in human gastric biopsies. The H. pylori infection-induced down-regulation of NEIL2 is specific, as Campylobacter jejuni has no such effect. Using gastric organoids isolated from the murine stomach in co-culture studies with live bacteria mimicking the infected stomach lining, we found that H. pylori infection was associated with IL-8 production; th...

Research paper thumbnail of Enhancing interval constraint propagation by identifying and filtering n-ary subsystems

Enhancing interval constraint propagation by identifying and filtering n-ary subsystems

Journal of Global Optimization

Research paper thumbnail of AbsTaylor: Finding inner regions for nonlinear constraint systems with linearizations and absolute values

AbsTaylor: Finding inner regions for nonlinear constraint systems with linearizations and absolute values

Research paper thumbnail of {"__content__"=>"Expression of Programmed Death-Ligand 1 by Human Colonic CD90 Stromal Cells Differs Between Ulcerative Colitis and Crohn's Disease and Determines Their Capacity to Suppress Th1 Cells.", "sup"=>{"__content__"=>"+"}}

Frontiers in immunology, 2018

The role of programmed cell death protein 1 (PD-1) and its ligands in the dysregulation of T help... more The role of programmed cell death protein 1 (PD-1) and its ligands in the dysregulation of T helper immune responses observed in the inflammatory bowel disease (IBD) is unclear. Recently, a novel concept emerged that CD90 colonic (myo)fibroblasts (CMFs), also known as stromal cells, act as immunosuppressors, and are among the key regulators of acute and chronic inflammation. The objective of this study was to determine if the level of the PD-1 ligands is changed in the IBD inflamed colonic mucosa and to test the hypothesis that changes in IBD-CMF-mediated PD-1 ligand-linked immunosuppression is a mechanism promoting the dysregulation of Th1 cell responses. Tissues and cells derived from Crohn's disease (CD), ulcerative colitis (UC), and healthy individuals (N) were studied , and in culture. A significant increase in programmed death-ligand 1 (PD-L1) was observed in the inflamed UC colonic mucosa when compared to the non-inflamed matched tissue samples, CD, and healthy controls. ...

Research paper thumbnail of Reacción de la pulpa dentaria ante la presencia de la caries y los tratamientos dentales

Odontología Sanmarquina, 2014

Este artículo revisa las diferentes reacciones de la pulpa dentaria ante las injurias provocadas ... more Este artículo revisa las diferentes reacciones de la pulpa dentaria ante las injurias provocadas por la caries dental y por los diferentes tratamientos restauradores que se realizan sobre ella, de donde se deduce como objetivo principal el dar a conocer al odontólogo de práctica general, los conocimientos pertinentes para orientar, prevenir y conservar la salud de la pulpa dentaria.

Research paper thumbnail of Abordaje quirúrgico de los dientes supernumerarios

Odontología Sanmarquina, 2014

Este reporte de caso clínico presenta la secuencia clínica del tratamiento quirúrgico de un dient... more Este reporte de caso clínico presenta la secuencia clínica del tratamiento quirúrgico de un diente supernumerario en posición transversal. El tratamiento quirúrgico (exodoncia) de los dientes supernumerarios están indicados en piezas incluidas y que están además dentro de las arcadas dentarias; esta patología odontogénica suele ser encontrada de manera esporádica durante los exámenes complementarios; sin embargo, el no abordarlo y tratarlo pueden devenir en otra patología dentaria que involucre piezas adyacentes a la lesión. Se presenta la secuencia clínica del abordaje quirúrgico para extraer una pieza dentaria supernumeraria en posición transversal.

Research paper thumbnail of Tratamiento pulpar en la apexificación del diente inmaduro mediante agregado de trióxido mineral

Odontología Sanmarquina, 2014

Este artículo revisa las publicaciones sobre el Agregado Trióxido Mineral (MTA) para el uso y apl... more Este artículo revisa las publicaciones sobre el Agregado Trióxido Mineral (MTA) para el uso y aplicación en los tratamientos pulpares de los dientes permanentes jóvenes (ápices inmaduros), como la apexificación. Inicialmente el cemento de MTA fue empleado para resolver complicaciones de perforaciones radiculares, así como obturaciones retrógradas, además de poseer características que lo diferencian del cemento Portland. En la elección del tipo de tratamiento de lesiones pulpares de dientes vitales y no vitales, se revisa el proceso de rizogénesis desde el punto de vista embriológico, los diferentes estadios de desarrollo radicular y apical del diente inmaduro, comparándolo con la clasificación de calcificación del estadio de Nolla. Por lo que, la apexificación es una alternativa de tratamiento muy usada para la pulpa no vital, siendo el Hidróxido de calcio y el MTA los materiales comúnmente usados y que posteriormente, cuando exista formación del nuevo tejido para el cierre apical, ...

Research paper thumbnail of Síndrome de dolor miofascial. Epidemiologia, fisiopatología, diagnóstico y tratamiento

Revista De Especialidades Medico Quirurgicas, 2013

El síndrome de dolor miofascial se define por la manifestación de puntos gatillo miofasciales en ... more El síndrome de dolor miofascial se define por la manifestación de puntos gatillo miofasciales en una banda tensa y palpable que produce dolor y sensibilidad en el músculo o en su fascia. Es una causa común de dolor musculoesquelético que se asocia, en la mayoría de los casos, con otras afecciones y que aumenta las comorbilidades de estas enfermedades primarias. Entender la fisiopatología de este síndrome y conocer los tratamientos farmacológicos y no farmacológicos le proporciona al clínico herramientas para mejorar la calidad de vida de los pacientes que sufren dolor. En México es una enfermedad subdiagnosticada, aunque tiene alta prevalencia. Se revisa la epidemiología, fisiopatología, diagnóstico y tratamiento de esta afección.

Research paper thumbnail of Prediction of alpha helices and T cell-presented sequences in proteins with algorithms based on strip-of-helix hydrophobicity index

Prediction of alpha helices and T cell-presented sequences in proteins with algorithms based on strip-of-helix hydrophobicity index

Methods in Enzymology, Feb 1, 1991

Recurrent aliphatic hydrophobic amino acids which occur in the sequence of a protein or a peptide... more Recurrent aliphatic hydrophobic amino acids which occur in the sequence of a protein or a peptide at positions which form an axial, hydrophobic strip when the sequence is coiled as an alpha helix might stabilize coiling against hydrophobic surfaces. That effect can lead to helix formation against hydrophobic cores of nascent proteins or excised T cell-presented peptides and to protease protection and scavenging for presentation by MHC molecules. Such consensus sequences of recurrent hydrophobicity creating a scavenger "S" site might overlap to varying degrees the T cell-presented "T" epitope which actually sits in the antigen-binding site of a MHC molecules, as long as a cleavage "C" site does not fall between them when they are relatively separated. Cooperatively among the residues in an axial, hydrophobic strip to stabilize helix formation is reflected in the SOHHI, which is the mean hydrophobicity of residues in such potential strips. Algorithms based on the SOHHI, with additional considerations related to length and caps, lead to sensitive and efficient predictions of structural helices and of T cell-presented epitopes. In experimental tests of these ideas, the SOHHI was found to correlate to helical coiling of amphiphilic peptides in the presence of lipid vesicles. These principles lead to hypotheses to alter the potency and range of MHC restriction of peptide vaccines or to decrease the immunogenicity of therapeutic proteins.

Research paper thumbnail of Colloid Cysts of the Third Ventricle: Report of Seven Cases

Colloid Cysts of the Third Ventricle: Report of Seven Cases

Jns, 1953

1. J Neurosurg. 1953 May;10(3):242-63. Colloid cysts of the third ventricle; report of seven case... more 1. J Neurosurg. 1953 May;10(3):242-63. Colloid cysts of the third ventricle; report of seven cases. POPPEN JL, REYES V, HORRAX G. PMID: 13053254 [PubMed - OLDMEDLINE]. MeSH Terms: Cysts*.

Research paper thumbnail of Multi/many-core programming: Where are we standing?

Multi/many-core programming: Where are we standing?

2015 Design Automation Test in Europe Conference Exhibition, Mar 1, 2015

Research paper thumbnail of Adsorption and Helical Coiling of Amphipathic Peptides on Lipid Vesicles Leads to Negligible Protection from Cathepsin B or Cathepsin D

Adsorption and Helical Coiling of Amphipathic Peptides on Lipid Vesicles Leads to Negligible Protection from Cathepsin B or Cathepsin D

The processing of antigenic peptides for presentation by MHC molecules to T cells, may depend upo... more The processing of antigenic peptides for presentation by MHC molecules to T cells, may depend upon the function of a second, consensus sequence in or near the T cell-presented epitope. One such processing-regulating sequence appears to be composed of amino acids Leu, Ile, Val, Phe, and Met recurring in a fashion to form a longitudinal, hydrophobic strip when the excised peptide is coiled as an alpha-helix. Such a hydrophobic strip-of-helix may: (a) scavenge peptides from lumens onto lipid membranes of digestion vesicles, (b) stabilize peptides there as protease-resistant helices, (c) specify recognition by the antigenic peptide-binding sites of chaperonin proteins, transmembranal transporters, or MHC molecules. By circular dichroism and electron paramagnetic resonance, we demonstrated that peptides with recurrent hydrophobic residues potentially forming longitudinal strips adsorbed to, and partially coiled as helices on, di-O-hexadecyl, D-L-alpha-phosphatidylcholine (DHPC) vesicles. Cathepsin B or cathepsin D cleavages of three such peptides were identified. With either enzyme, it made no significant difference whether a peptide substrate was in solution or bound to vesicles in terms of efficiency and specificity of peptide bond cleavages. We conclude that protease resistance, per se, of membrane-adsorbed, helically coiled peptides is not a major factor in the selection for T cell presentation of epitopes in peptides which have a motif with a longitudinal hydrophobic strip.

Research paper thumbnail of Interferon alpha/beta synthesis during acute graft-versus-host disease

Interferon alpha/beta synthesis during acute graft-versus-host disease

Transplantation, Apr 1, 1987

Graft-versus-host disease (GVHD) is a major obstacle to successful bone marrow transplantation. T... more Graft-versus-host disease (GVHD) is a major obstacle to successful bone marrow transplantation. The role of interferon (IFN) in GVHD is currently unclear. We have previously shown that interferon (IFN) is produced in vitro by alloantigen-stimulated murine bone marrow cells. This study was initiated to examine whether IFN production occurs in vivo during GVHD. Lethally irradiated mice were given bone marrow (10(7)) and/or spleen cells (2 X 10(7)) from either allogeneic or syngeneic mice. Mice given allogeneic spleen cells or bone marrow and spleen cells showed signs of GVHD within 10 days and usually died within 20 days of transplantation. Mice undergoing GVHD were found to have significant levels of IFN activity in their sera. Serum IFN was detected early (day 3) after transplantation with optimal IFN activity (greater than or equal to 80 units) occurring at 5-6 days. The IFN activity present in the sera obtained from mice with GVHD was identified as IFN alpha/beta by using specific antisera against IFN alpha/beta and IFN gamma. In contrast, irradiated mice given T-cell-depleted allogeneic bone marrow and spleen cells failed to develop GVHD and had no detectable serum IFN activity. Irradiated mice given syngeneic bone marrow and spleen cells or only allogeneic bone marrow cells did not develop GVHD and did not produce detectable IFN activity in their sera. These results show that serum IFN activity correlates well with GVHD and opens for speculation the possibility that IFN may be involved in the pathogenesis associated with GVHD.

Research paper thumbnail of Solving Manufacturing Cell Design Problems by Using a Bat Algorithm Approach

Solving Manufacturing Cell Design Problems by Using a Bat Algorithm Approach

Lecture Notes in Computer Science, 2016

Research paper thumbnail of Helicobacter pylori CagA-Dependent Macrophage Migration Inhibitory Factor Produced by Gastric Epithelial Cells Binds to CD74 and Stimulates Procarcinogenic Events1

The Journal of Immunology, Jun 1, 2006

Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine that has recently been... more Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine that has recently been implicated in carcinogenesis. Helicobacter pylori, which is closely linked to gastric cancer, induces the gastric epithelium to produce proinflammatory cytokines, including MIF. MIF can bind to CD74, which we have previously shown to be highly expressed on the surface of gastric epithelial cells (GEC) during H. pylori infection. In this study, we sought to investigate the role of the H. pylori-induced MIF on epithelial proliferation and procarcinogenic events. Upon establishing a role for the H. pylori CagA virulence factor in MIF production, MIF binding to CD74 on GEC was confirmed. rMIF and H. pylori were shown to increase GEC proliferation, which was decreased when cagA ؊ strains were used and when CD74 was blocked by mAbs. Apoptosis was also decreased by MIF, but increased by cagA ؊ strains that induced much lower amounts of MIF than the wild-type bacteria. Furthermore, MIF binding to CD74 was also shown to decrease p53 phosphorylation and up-regulate Bcl-2 expression. This data describes a novel system in which an H. pylori virulence factor contributes to the production of a host factor that in turn up-regulates procarcinogenic events by the gastric epithelium.

Research paper thumbnail of Exploring the mind-body connection in patients with diabetes and hypertension

Exploring the mind-body connection in patients with diabetes and hypertension

Research paper thumbnail of Highly restricted distributions of hydrophobic and charged amino acids in longitudinal quadrants of alpha-helices

Highly restricted distributions of hydrophobic and charged amino acids in longitudinal quadrants of alpha-helices

Journal of Biological Chemistry

Research paper thumbnail of Number and placement of hydrophobic residues in a longitudinal strip governs helix formation of peptides in the presence of lipid vesicles

Number and placement of hydrophobic residues in a longitudinal strip governs helix formation of peptides in the presence of lipid vesicles

Journal of Biological Chemistry

Research paper thumbnail of AbsTaylor: upper bounding with inner regions in nonlinear continuous global optimization problems

AbsTaylor: upper bounding with inner regions in nonlinear continuous global optimization problems

Journal of Global Optimization

Research paper thumbnail of A GRASP-based scheme for the set covering problem

A GRASP-based scheme for the set covering problem

Operational Research

Research paper thumbnail of NEIL2 plays a critical role in limiting inflammation and preserving genomic integrity in H. pylori-infected gastric epithelial cells

The accumulation of Helicobacter pylori infection-induced oxidative DNA damage in gastric epithel... more The accumulation of Helicobacter pylori infection-induced oxidative DNA damage in gastric epithelial cells is a risk factor for developing gastric cancer (GC); however, the underlying mechanisms remain poorly understood. Here we report that the suppression of NEIL2, an oxidized base-specific mammalian DNA glycosylase, is one such mechanism via which H. pylori infection may fuel the accumulation of DNA damage during the initiation and progression of GC. Using a combination of cultured cell lines and primary cells, we show that expression of NEIL2 is significantly down-regulated after H. pylori infection; such down-regulation was also seen in human gastric biopsies. The H. pylori infection-induced down-regulation of NEIL2 is specific, as Campylobacter jejuni has no such effect. Using gastric organoids isolated from the murine stomach in co-culture studies with live bacteria mimicking the infected stomach lining, we found that H. pylori infection was associated with IL-8 production; th...

Research paper thumbnail of Enhancing interval constraint propagation by identifying and filtering n-ary subsystems

Enhancing interval constraint propagation by identifying and filtering n-ary subsystems

Journal of Global Optimization

Research paper thumbnail of AbsTaylor: Finding inner regions for nonlinear constraint systems with linearizations and absolute values

AbsTaylor: Finding inner regions for nonlinear constraint systems with linearizations and absolute values

Research paper thumbnail of {"__content__"=>"Expression of Programmed Death-Ligand 1 by Human Colonic CD90 Stromal Cells Differs Between Ulcerative Colitis and Crohn's Disease and Determines Their Capacity to Suppress Th1 Cells.", "sup"=>{"__content__"=>"+"}}

Frontiers in immunology, 2018

The role of programmed cell death protein 1 (PD-1) and its ligands in the dysregulation of T help... more The role of programmed cell death protein 1 (PD-1) and its ligands in the dysregulation of T helper immune responses observed in the inflammatory bowel disease (IBD) is unclear. Recently, a novel concept emerged that CD90 colonic (myo)fibroblasts (CMFs), also known as stromal cells, act as immunosuppressors, and are among the key regulators of acute and chronic inflammation. The objective of this study was to determine if the level of the PD-1 ligands is changed in the IBD inflamed colonic mucosa and to test the hypothesis that changes in IBD-CMF-mediated PD-1 ligand-linked immunosuppression is a mechanism promoting the dysregulation of Th1 cell responses. Tissues and cells derived from Crohn's disease (CD), ulcerative colitis (UC), and healthy individuals (N) were studied , and in culture. A significant increase in programmed death-ligand 1 (PD-L1) was observed in the inflamed UC colonic mucosa when compared to the non-inflamed matched tissue samples, CD, and healthy controls. ...

Research paper thumbnail of Reacción de la pulpa dentaria ante la presencia de la caries y los tratamientos dentales

Odontología Sanmarquina, 2014

Este artículo revisa las diferentes reacciones de la pulpa dentaria ante las injurias provocadas ... more Este artículo revisa las diferentes reacciones de la pulpa dentaria ante las injurias provocadas por la caries dental y por los diferentes tratamientos restauradores que se realizan sobre ella, de donde se deduce como objetivo principal el dar a conocer al odontólogo de práctica general, los conocimientos pertinentes para orientar, prevenir y conservar la salud de la pulpa dentaria.

Research paper thumbnail of Abordaje quirúrgico de los dientes supernumerarios

Odontología Sanmarquina, 2014

Este reporte de caso clínico presenta la secuencia clínica del tratamiento quirúrgico de un dient... more Este reporte de caso clínico presenta la secuencia clínica del tratamiento quirúrgico de un diente supernumerario en posición transversal. El tratamiento quirúrgico (exodoncia) de los dientes supernumerarios están indicados en piezas incluidas y que están además dentro de las arcadas dentarias; esta patología odontogénica suele ser encontrada de manera esporádica durante los exámenes complementarios; sin embargo, el no abordarlo y tratarlo pueden devenir en otra patología dentaria que involucre piezas adyacentes a la lesión. Se presenta la secuencia clínica del abordaje quirúrgico para extraer una pieza dentaria supernumeraria en posición transversal.

Research paper thumbnail of Tratamiento pulpar en la apexificación del diente inmaduro mediante agregado de trióxido mineral

Odontología Sanmarquina, 2014

Este artículo revisa las publicaciones sobre el Agregado Trióxido Mineral (MTA) para el uso y apl... more Este artículo revisa las publicaciones sobre el Agregado Trióxido Mineral (MTA) para el uso y aplicación en los tratamientos pulpares de los dientes permanentes jóvenes (ápices inmaduros), como la apexificación. Inicialmente el cemento de MTA fue empleado para resolver complicaciones de perforaciones radiculares, así como obturaciones retrógradas, además de poseer características que lo diferencian del cemento Portland. En la elección del tipo de tratamiento de lesiones pulpares de dientes vitales y no vitales, se revisa el proceso de rizogénesis desde el punto de vista embriológico, los diferentes estadios de desarrollo radicular y apical del diente inmaduro, comparándolo con la clasificación de calcificación del estadio de Nolla. Por lo que, la apexificación es una alternativa de tratamiento muy usada para la pulpa no vital, siendo el Hidróxido de calcio y el MTA los materiales comúnmente usados y que posteriormente, cuando exista formación del nuevo tejido para el cierre apical, ...

Research paper thumbnail of Síndrome de dolor miofascial. Epidemiologia, fisiopatología, diagnóstico y tratamiento

Revista De Especialidades Medico Quirurgicas, 2013

El síndrome de dolor miofascial se define por la manifestación de puntos gatillo miofasciales en ... more El síndrome de dolor miofascial se define por la manifestación de puntos gatillo miofasciales en una banda tensa y palpable que produce dolor y sensibilidad en el músculo o en su fascia. Es una causa común de dolor musculoesquelético que se asocia, en la mayoría de los casos, con otras afecciones y que aumenta las comorbilidades de estas enfermedades primarias. Entender la fisiopatología de este síndrome y conocer los tratamientos farmacológicos y no farmacológicos le proporciona al clínico herramientas para mejorar la calidad de vida de los pacientes que sufren dolor. En México es una enfermedad subdiagnosticada, aunque tiene alta prevalencia. Se revisa la epidemiología, fisiopatología, diagnóstico y tratamiento de esta afección.

Research paper thumbnail of Prediction of alpha helices and T cell-presented sequences in proteins with algorithms based on strip-of-helix hydrophobicity index

Prediction of alpha helices and T cell-presented sequences in proteins with algorithms based on strip-of-helix hydrophobicity index

Methods in Enzymology, Feb 1, 1991

Recurrent aliphatic hydrophobic amino acids which occur in the sequence of a protein or a peptide... more Recurrent aliphatic hydrophobic amino acids which occur in the sequence of a protein or a peptide at positions which form an axial, hydrophobic strip when the sequence is coiled as an alpha helix might stabilize coiling against hydrophobic surfaces. That effect can lead to helix formation against hydrophobic cores of nascent proteins or excised T cell-presented peptides and to protease protection and scavenging for presentation by MHC molecules. Such consensus sequences of recurrent hydrophobicity creating a scavenger "S" site might overlap to varying degrees the T cell-presented "T" epitope which actually sits in the antigen-binding site of a MHC molecules, as long as a cleavage "C" site does not fall between them when they are relatively separated. Cooperatively among the residues in an axial, hydrophobic strip to stabilize helix formation is reflected in the SOHHI, which is the mean hydrophobicity of residues in such potential strips. Algorithms based on the SOHHI, with additional considerations related to length and caps, lead to sensitive and efficient predictions of structural helices and of T cell-presented epitopes. In experimental tests of these ideas, the SOHHI was found to correlate to helical coiling of amphiphilic peptides in the presence of lipid vesicles. These principles lead to hypotheses to alter the potency and range of MHC restriction of peptide vaccines or to decrease the immunogenicity of therapeutic proteins.

Research paper thumbnail of Colloid Cysts of the Third Ventricle: Report of Seven Cases

Colloid Cysts of the Third Ventricle: Report of Seven Cases

Jns, 1953

1. J Neurosurg. 1953 May;10(3):242-63. Colloid cysts of the third ventricle; report of seven case... more 1. J Neurosurg. 1953 May;10(3):242-63. Colloid cysts of the third ventricle; report of seven cases. POPPEN JL, REYES V, HORRAX G. PMID: 13053254 [PubMed - OLDMEDLINE]. MeSH Terms: Cysts*.

Research paper thumbnail of Multi/many-core programming: Where are we standing?

Multi/many-core programming: Where are we standing?

2015 Design Automation Test in Europe Conference Exhibition, Mar 1, 2015

Research paper thumbnail of Adsorption and Helical Coiling of Amphipathic Peptides on Lipid Vesicles Leads to Negligible Protection from Cathepsin B or Cathepsin D

Adsorption and Helical Coiling of Amphipathic Peptides on Lipid Vesicles Leads to Negligible Protection from Cathepsin B or Cathepsin D

The processing of antigenic peptides for presentation by MHC molecules to T cells, may depend upo... more The processing of antigenic peptides for presentation by MHC molecules to T cells, may depend upon the function of a second, consensus sequence in or near the T cell-presented epitope. One such processing-regulating sequence appears to be composed of amino acids Leu, Ile, Val, Phe, and Met recurring in a fashion to form a longitudinal, hydrophobic strip when the excised peptide is coiled as an alpha-helix. Such a hydrophobic strip-of-helix may: (a) scavenge peptides from lumens onto lipid membranes of digestion vesicles, (b) stabilize peptides there as protease-resistant helices, (c) specify recognition by the antigenic peptide-binding sites of chaperonin proteins, transmembranal transporters, or MHC molecules. By circular dichroism and electron paramagnetic resonance, we demonstrated that peptides with recurrent hydrophobic residues potentially forming longitudinal strips adsorbed to, and partially coiled as helices on, di-O-hexadecyl, D-L-alpha-phosphatidylcholine (DHPC) vesicles. Cathepsin B or cathepsin D cleavages of three such peptides were identified. With either enzyme, it made no significant difference whether a peptide substrate was in solution or bound to vesicles in terms of efficiency and specificity of peptide bond cleavages. We conclude that protease resistance, per se, of membrane-adsorbed, helically coiled peptides is not a major factor in the selection for T cell presentation of epitopes in peptides which have a motif with a longitudinal hydrophobic strip.

Research paper thumbnail of Interferon alpha/beta synthesis during acute graft-versus-host disease

Interferon alpha/beta synthesis during acute graft-versus-host disease

Transplantation, Apr 1, 1987

Graft-versus-host disease (GVHD) is a major obstacle to successful bone marrow transplantation. T... more Graft-versus-host disease (GVHD) is a major obstacle to successful bone marrow transplantation. The role of interferon (IFN) in GVHD is currently unclear. We have previously shown that interferon (IFN) is produced in vitro by alloantigen-stimulated murine bone marrow cells. This study was initiated to examine whether IFN production occurs in vivo during GVHD. Lethally irradiated mice were given bone marrow (10(7)) and/or spleen cells (2 X 10(7)) from either allogeneic or syngeneic mice. Mice given allogeneic spleen cells or bone marrow and spleen cells showed signs of GVHD within 10 days and usually died within 20 days of transplantation. Mice undergoing GVHD were found to have significant levels of IFN activity in their sera. Serum IFN was detected early (day 3) after transplantation with optimal IFN activity (greater than or equal to 80 units) occurring at 5-6 days. The IFN activity present in the sera obtained from mice with GVHD was identified as IFN alpha/beta by using specific antisera against IFN alpha/beta and IFN gamma. In contrast, irradiated mice given T-cell-depleted allogeneic bone marrow and spleen cells failed to develop GVHD and had no detectable serum IFN activity. Irradiated mice given syngeneic bone marrow and spleen cells or only allogeneic bone marrow cells did not develop GVHD and did not produce detectable IFN activity in their sera. These results show that serum IFN activity correlates well with GVHD and opens for speculation the possibility that IFN may be involved in the pathogenesis associated with GVHD.

Research paper thumbnail of Solving Manufacturing Cell Design Problems by Using a Bat Algorithm Approach

Solving Manufacturing Cell Design Problems by Using a Bat Algorithm Approach

Lecture Notes in Computer Science, 2016

Research paper thumbnail of Helicobacter pylori CagA-Dependent Macrophage Migration Inhibitory Factor Produced by Gastric Epithelial Cells Binds to CD74 and Stimulates Procarcinogenic Events1

The Journal of Immunology, Jun 1, 2006

Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine that has recently been... more Macrophage migration inhibitory factor (MIF) is a proinflammatory cytokine that has recently been implicated in carcinogenesis. Helicobacter pylori, which is closely linked to gastric cancer, induces the gastric epithelium to produce proinflammatory cytokines, including MIF. MIF can bind to CD74, which we have previously shown to be highly expressed on the surface of gastric epithelial cells (GEC) during H. pylori infection. In this study, we sought to investigate the role of the H. pylori-induced MIF on epithelial proliferation and procarcinogenic events. Upon establishing a role for the H. pylori CagA virulence factor in MIF production, MIF binding to CD74 on GEC was confirmed. rMIF and H. pylori were shown to increase GEC proliferation, which was decreased when cagA ؊ strains were used and when CD74 was blocked by mAbs. Apoptosis was also decreased by MIF, but increased by cagA ؊ strains that induced much lower amounts of MIF than the wild-type bacteria. Furthermore, MIF binding to CD74 was also shown to decrease p53 phosphorylation and up-regulate Bcl-2 expression. This data describes a novel system in which an H. pylori virulence factor contributes to the production of a host factor that in turn up-regulates procarcinogenic events by the gastric epithelium.

Research paper thumbnail of Exploring the mind-body connection in patients with diabetes and hypertension

Exploring the mind-body connection in patients with diabetes and hypertension