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1.
Eval Rev ; 34(3): 159-84, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20479211

RESUMEN

OBJECTIVES: Establish metric properties of the Neighborhood Inventory for Environmental Typology (NIfETy). METHOD: A total of 919 residential block faces were assessed by paired raters using the NIfETy. Reliability was evaluated via interrater and internal consistency reliability; validity by comparing NIfETy data with youth self-reported violence, alcohol, and other drug exposure and crime statistics. RESULTS: Validity and reliability metrics were moderate to exemplary for the total scale and subscales. NIfETy data correlated strongly with crime data and youth self-reported exposure. CONCLUSIONS: The NIfETy is valid and reliable. Future investigations will explore its use in other urban centers and association to other health outcomes.


Asunto(s)
Características de la Residencia , Fumar , Medio Social , Trastornos Relacionados con Sustancias , Violencia , Adolescente , Baltimore , Femenino , Humanos , Estudios Longitudinales , Masculino , Encuestas y Cuestionarios/normas , Adulto Joven
2.
Mol Reprod Dev ; 74(1): 88-96, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-16941670

RESUMEN

The ability of synthetic arginine-glycine-aspartic acid (RGD)-containing peptides to induce intracellular calcium transients similar to those observed at fertilization by spermatozoa in the bovine has been reported (Campbell et al., 2000: Biol Reprod 62:1702-1709; Sessions et al., 2006. Mol Reprod Dev). These results also indicated the ability of synthetic RGD-containing peptides to induce activation and subsequent parthenogenetic development to the blastocyst stage, although, at numbers lower than observed with control in vitro fertilization (IVF). Evidence has been provided indicating the important effect of surrounding regions on the biological activity of the RGD sequence (Zhu and Evans, 2002; Sessions et al., 2006). The current experiments were designed to use natural RGD-containing sequences (disintegrins) to understand their effects. A total of three RGD-containing snake venom peptides (Kistrin (K), Elegantin (Ele), and Echistatin (Ech)) and one nonRGD-containing venom (Erabutoxin B (EB; control) were used at three concentrations (0.1, 1, and 10 micro g /ml) to induce parthenogenetic development to the blastocyst stage and in conjunction (1.0, 5.0, and 10 micro g/ml) with spermatozoa to evaluate competitive inhibition of fertilization and subsequent development. A (P < 0.01) higher number of bovine oocytes developed to the blastocyst stage after incubation with K, Ele and Ech at 1.0 micro g/ml, and was not different (P > 0.01) from IVF control. Fertilization was significantly reduced (P < 0.01) at all concentrations of K, Ele and Ech as compared to IVF control. No reduction (P > 0.05) was observed in EB (nonRGD) treated oocytes. These results support the involvement of a disintegrin-integrin interaction at fertilization in the bovine resulting in activation and subsequent development.


Asunto(s)
Bovinos/embriología , Fertilización In Vitro/efectos de los fármacos , Oligopéptidos/farmacología , Oocitos/efectos de los fármacos , Partenogénesis/efectos de los fármacos , Venenos de Serpiente/química , Secuencia de Aminoácidos , Animales , Calcio/farmacología , Cationes Bivalentes/farmacología , Femenino , Magnesio/farmacología , Manganeso/farmacología , Datos de Secuencia Molecular , Oligopéptidos/análisis , Oocitos/crecimiento & desarrollo , Péptidos/síntesis química , Péptidos/química , Péptidos/farmacología , Reacción en Cadena de la Polimerasa
3.
Cloning Stem Cells ; 3(3): 105-13, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11945220

RESUMEN

An arginine-glycine-aspartic acid (RGD)-containing peptide has been reported to generate calcium transients in bovine oocytes similar to those observed at fertilization. The research objective herein was to evaluate the response of bovine oocytes to an RGD peptide after injection with known antagonists of calcium releasing mechanisms in order to determine the initial calcium releasing pathway. Oocytes were injected with either heparin, an inhibitor of inositol 1,4,5-trisphosphate (IP3) induced calcium response, or procaine, which inhibits calcium release through the ryanodine receptor. Oocytes injected with heparin prior to RGD exposure did not display a calcium response. Oocytes injected with procaine prior to RGD exposure did exhibit a calcium response. Electroporation of IP3, caffeine, or exposure to RGD alone elicited a calcium response for each treatment group. Injection of heparin, procaine, vehicle medium (VM), or exposure to a non-RGD-containing peptide alone failed to elicit a calcium response. The data indicates that the RGD peptide is able to induce calcium transients in oocytes inhibited with procaine, but not those inhibited with heparin. These data suggest the pathway whereby the RGD peptide induces the first intracellular calcium transient in bovine oocytes is through IP3-mediated stores.


Asunto(s)
Señalización del Calcio , Calcio/metabolismo , Bovinos/embriología , Oligopéptidos/farmacología , Oocitos/metabolismo , Animales , Cafeína/farmacología , Femenino , Fibrinolíticos/farmacología , Heparina/farmacología , Inosina Trifosfato/farmacología , Oocitos/efectos de los fármacos , Procaína/farmacología , Canal Liberador de Calcio Receptor de Rianodina/metabolismo , Factores de Tiempo
4.
J Pept Res ; 58(6): 515-26, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-12005421

RESUMEN

Four members of the carcinoembryonic antigen family, CEACAM1, CEACAM8, CEACAM6 and CEACAM3, recognized by CD66a, CD66b, CD66c and CD66d monoclonal antibodies (mAb), respectively, are expressed on human neutrophils. CD66a, CD66b, CD66c and CD66d mAb binding to neutrophils triggers an activation signal that regulates the adhesive activity of CD11/CD18, resulting in an increase in neutrophil adhesion to human umbilical vein endothelial cells. Molecular modeling of CEACAM1 using IgG and CD4 as models has been performed, and three peptides from the N-terminal domain were found to increase neutrophil adhesion to human umbilical vein endothelial cell monolayers. The peptides were 14 amino acids in length and were predicted to be present at loops and turns between beta-sheets. To better understand the amino acid sequences critical for this biological activity, in the present study we examined the other neutrophil CEACAMs and the highly homologous CEACAM, CEA. Molecular modeling of the N-terminal domains of human CEACAM8, -6, -3 and CEA was performed. Twenty peptides, each 14 amino acids in length, that were homologous to the previously reported peptides from the N-domains of CEACAM1, were synthesized and tested for their ability to alter neutrophil adhesion. Only one new peptide, from the N-domain of CEA, was found to increase neutrophil adhesion, and this peptide differed from the corresponding CEACAM1 peptide by only a single conservative amino acid substitution. Importantly, minor amino acid differences between active and inactive homologous peptides suggest regions of these peptides that are critical for biological activity. The data suggest that the regions SMPF of peptide CD66a-1, QLFG of peptide CD66a-2 and NRQIV of peptide CD66a-3 are critical for the activities of these peptides, and for the native CEACAMs.


Asunto(s)
Activación Neutrófila/efectos de los fármacos , Péptidos/química , Péptidos/farmacología , Antígenos CD/química , Antígenos CD/metabolismo , Antígenos de Diferenciación/química , Antígenos de Diferenciación/metabolismo , Antígeno Carcinoembrionario/química , Antígeno Carcinoembrionario/metabolismo , Adhesión Celular/efectos de los fármacos , Moléculas de Adhesión Celular/química , Células Cultivadas , Evaluación Preclínica de Medicamentos , Endotelio Vascular/citología , Endotelio Vascular/efectos de los fármacos , Humanos , Selectina L/efectos de los fármacos , Selectina L/metabolismo , Antígeno de Macrófago-1/efectos de los fármacos , Antígeno de Macrófago-1/metabolismo , Neutrófilos/efectos de los fármacos , Neutrófilos/metabolismo , Péptidos/síntesis química , Relación Estructura-Actividad
5.
Biol Reprod ; 62(6): 1702-9, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10819774

RESUMEN

The ability of arginine-glycine-aspartic acid (RGD; a sequence recognized by integrins) or non-RGD-containing peptides to block fertilization, induce intracellular Ca(2+) oscillations, and initiate parthenogenetic development in bovine oocytes was investigated. Addition of a soluble RGD peptide during fertilization at concentrations ranging from 10 to 1000 microg/ml significantly decreased (P<0.05) fertilization as compared to the in vitro-fertilized controls. The addition of non-RGD peptide had no effect on fertilization. Two intracellular Ca(2+) transients 21.5+/- 1.9 min apart were observed in 56 of 60 oocytes incubated in RGD peptide concentrations ranging from 20 to 1000 microg/ml. No intracellular Ca(2+) transients were observed in medium alone, non-RGD treatment groups or in the RGD peptide at 10 microg/ml. The percentage of oocytes activated with ionomycin and 6-dimethylaminopurine (63% cleavage and 34% blastocyst development) was significantly higher (P<0.05) than those activated with the RGD peptide and 6-dimethylaminopurine (35% cleavage and 19% blastocyst development). These groups were significantly higher (P<0.05) than either peptide alone, 6-dimethylaminopurine alone, or the non-RGD peptide and 6-dimethylaminopurine treatment groups. These data provide evidence that ligation of an integrin on bovine oocytes with a soluble RGD peptide is capable of blocking fertilization, inducing intracellular Ca(2+) transients, and initiating parthenogenetic development.


Asunto(s)
Calcio/metabolismo , Fertilización , Integrinas/fisiología , Oocitos/fisiología , Partenogénesis , Adenina/análogos & derivados , Adenina/farmacología , Animales , Bovinos , Membrana Celular/metabolismo , Femenino , Fertilización/efectos de los fármacos , Fertilización In Vitro , Ionomicina/farmacología , Ionóforos/farmacología , Oligopéptidos/administración & dosificación , Oligopéptidos/metabolismo , Oligopéptidos/farmacología , Oocitos/efectos de los fármacos
6.
FEBS Lett ; 469(1): 52-6, 2000 Mar 03.
Artículo en Inglés | MEDLINE | ID: mdl-10708755

RESUMEN

CD63 antibody binding to the neutrophil surface triggers a transient activation signal that regulates the adhesive activity and surface expression of CD11/CD18. Gel permeation chromatography demonstrated that all of the cell surface CD11/CD18 associated with CD63 eluted in the void volume, indicating that they were present in large detergent-resistant complexes. In contrast, the majority of the total cellular CD63, CD11 and CD18, which are largely intracellular, was not present in complexes. The data suggest that intracellular CD11, CD18 and CD63 are not in detergent-resistant complexes, but enter such complexes following translocation to the cell surface.


Asunto(s)
Antígenos CD/metabolismo , Antígenos CD11/metabolismo , Antígenos CD18/metabolismo , Neutrófilos/inmunología , Glicoproteínas de Membrana Plaquetaria/metabolismo , Membrana Celular/inmunología , Cromatografía en Gel , Detergentes , Humanos , Immunoblotting , Pruebas de Precipitina , Tetraspanina 30
7.
J Immunol ; 164(8): 4257-64, 2000 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-10754323

RESUMEN

Four members of the carcinoembryonic Ag family, CD66a, CD66b, CD66c, and CD66d, are expressed on human neutrophils. CD66a, CD66b, CD66c, and CD66d Ab binding to the neutrophil surface triggers an activation signal that regulates the adhesive activity of CD11/CD18, resulting in an increase in neutrophil adhesion to HUVEC. To identify active sites on the CD66a Ag, molecular modeling was performed using IgG and CD4 as models, and 28 peptides of 14 aa in length were synthesized that were predicted to be present at loops and turns between beta-sheets. The peptides were tested for their ability to alter neutrophil adhesion to HUVEC. Three peptides, each from the N-terminal domain, increased neutrophil adhesion to HUVEC monolayers. This increase in neutrophil adhesion caused by CD66a peptides was associated with up-regulation of CD11/CD18 and down-regulation of CD62L on the neutrophil surface. Scrambled versions of these three peptides had no effect on neutrophil adhesion to the endothelial cells. The data suggest that peptide motifs from at least three regions of the N-terminal domain of CD66a are involved in the interaction of CD66a with other ligands and can initiate signal transduction in neutrophils.


Asunto(s)
Antígenos CD/inmunología , Antígenos de Diferenciación/inmunología , Endotelio Vascular/inmunología , Neutrófilos/inmunología , Fragmentos de Péptidos/síntesis química , Fragmentos de Péptidos/inmunología , Antígenos CD/fisiología , Antígenos de Diferenciación/fisiología , Adhesión Celular/inmunología , Moléculas de Adhesión Celular , Línea Celular , Membrana Celular/inmunología , Membrana Celular/metabolismo , Regulación hacia Abajo/inmunología , Endotelio Vascular/citología , Humanos , Selectina L/biosíntesis , Ligandos , Antígeno de Macrófago-1/biosíntesis , Neutrófilos/metabolismo , Fragmentos de Péptidos/farmacología , Regulación hacia Arriba/inmunología
8.
FEBS Lett ; 439(1-2): 97-100, 1998 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-9849886

RESUMEN

CD44 appears to be involved in signal transduction, however, the mechanism of this function is unclear. Protein kinase activity was detected in neutrophils associated with CD44. Most of the protein kinase activity associated with these antigens was tyrosine kinase activity. Src family kinases lyn and hck were found to account for much of the associated tyrosine kinase activity. The data suggest that associated tyrosine kinase activity may play a role in signal transduction from CD44 in neutrophils to regulate other cell functions.


Asunto(s)
Receptores de Hialuranos/metabolismo , Neutrófilos/enzimología , Proteínas Tirosina Quinasas/metabolismo , Transducción de Señal/fisiología , Humanos , Neutrófilos/metabolismo , Proteínas Quinasas/metabolismo , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-hck , Familia-src Quinasas
9.
J Leukoc Biol ; 64(6): 800-2, 1998 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9850163

RESUMEN

CD43 appears to be involved in signal transduction, however, the mechanism of this function is unknown. Protein kinase activity was detected in neutrophils associated with CD43. Most of the protein kinase activity associated with these antigens was tyrosine kinase activity. The src family kinases lyn and hck were found to account for much of the associated tyrosine kinase activity. The data suggest that associated tyrosine kinase activity may play a role in signal transduction via CD43 to regulate other cell functions.


Asunto(s)
Antígenos CD , Neutrófilos/enzimología , Proteínas Tirosina Quinasas/metabolismo , Sialoglicoproteínas/fisiología , Humanos , Leucosialina , Neutrófilos/inmunología , Transducción de Señal/inmunología , Familia-src Quinasas/metabolismo
10.
FEBS Lett ; 426(3): 386-91, 1998 Apr 24.
Artículo en Inglés | MEDLINE | ID: mdl-9600272

RESUMEN

Integrins play a critical role in cell adhesion and mediate cell signaling. This report identifies the association of serine protein kinase activity with the beta 1 integrin by immunoprecipitation and phosphoamino acid analysis techniques. Reprecipitation techniques suggested that the serine kinase activity was not a member of the protein kinase C family. By gel filtration, most of the protein kinase activity associated with beta 1 integrin as well as most of the cell-surface beta 1 integrin was present in large detergent resistant complexes. These results suggest that serine protein kinase activity associated with the beta 1 integrin may play a role in signaling via the beta 1 integrin.


Asunto(s)
Detergentes , Integrina beta1/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Cromatografía en Gel , Activación Enzimática , Humanos , Integrina beta1/biosíntesis , Sustancias Macromoleculares , Proteínas de la Membrana/biosíntesis , Ácidos Fosfoaminos/análisis , Proteína Quinasa C/análisis , Células Tumorales Cultivadas
11.
Curr Microbiol ; 35(4): 207-14, 1997 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-9290060

RESUMEN

The cluster of genes encoding components of the progenitor botulinum neurotoxin complex has been mapped and cloned in Clostridium botulinum type G strain ATCC 27322. Determination of the nucleotide sequence of the region has revealed open reading frames encoding nontoxic components of the complex, upstream of the gene encoding BoNT/G (botG). The arrangement of these genes differs from that in strains of other antigenic toxin types. Immediately upstream of botG lies a gene encoding a protein of 1198 amino acids, which shows homology with the nontoxic-nonhemagglutinin (NTNH) component of the progenitor complex. Further upstream there are genes encoding proteins with homology to hemagglutinin components (HA-17, HA-70) and a putative positive regulator of gene expression (P-21). Sequence comparison has shown that BoNT/G has highest homology with BoNT/B. The sequence of the BoNT-cluster of genes in non-proteolytic C. botulinum type B strain Eklund 17B has been extended to include the complete NTNH and HA-17, and partial HA-70 gene sequences. Comparison of NTNH/G with other NTNHs reveals that it shows highest homology with NTNH/B consistent with the genealogical affinity shown between BoNT/G and BoNT/B genes.


Asunto(s)
Toxinas Botulínicas/genética , Clostridium botulinum/genética , Genes Bacterianos , Familia de Multigenes , Secuencia de Aminoácidos , Secuencia de Bases , Mapeo Cromosómico , Clonación Molecular , Clostridium botulinum/clasificación , Cartilla de ADN/genética , ADN Bacteriano/genética , Evolución Molecular , Hemaglutininas/genética , Datos de Secuencia Molecular , Reacción en Cadena de la Polimerasa , Homología de Secuencia de Aminoácido
12.
J Immunol ; 159(2): 820-8, 1997 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-9218600

RESUMEN

The constitutive high expression of CD50 (ICAM-3) on resting leukocytes, coupled with the observation that CD50 is the primary LFA-1 ligand on resting T cells, suggests that CD50 may be an important LFA-1 ligand in the initiation of the immune/inflammatory response. CD50 mAbs have been reported to increase homotypic adhesion of lymphocytes, and lymphocyte adhesion to HUVEC and extracellular matrix proteins. In this study, the effects of CD50 mAbs on neutrophil activation were examined. CD50 mAbs were found to inhibit neutrophil adhesion induced by FMLP and 12-O-tetradecanoyl-phorbol-13-acetate to resting and TNF-activated HUVEC. CD50 mAbs also inhibited neutrophil adhesion stimulated by CD66a, CD66b, CD66c, and CD66d mAbs to HUVEC. CD50 mAbs inhibited the up-regulation of CD11b/CD18 to the neutrophil surface, and the down-regulation of surface CD62L expression. The potential contribution of src family kinases to the previously described tyrosine kinase activity associated with CD50 in neutrophils was also examined. hck and lyn were found to account for much of the tyrosine kinase activity associated with CD50 in neutrophils. The data indicate that CD50 in neutrophils functions not only as a potential ligand for LFA-1, but also regulates the surface expression and activity of CD11b/CD18 and CD62L. In contrast to the effects in lymphocytes, CD50 appears to function as a negative regulator of neutrophil activation.


Asunto(s)
Anticuerpos Monoclonales/farmacología , Antígenos CD , Antígenos de Diferenciación , Moléculas de Adhesión Celular/inmunología , Activación Neutrófila/efectos de los fármacos , Anticuerpos Monoclonales/inmunología , Antígenos CD18/inmunología , Células Cultivadas , Citometría de Flujo , Humanos , Selectina L/inmunología , Activación Neutrófila/inmunología
13.
Int J Syst Bacteriol ; 46(4): 1105-12, 1996 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-8863443

RESUMEN

The cluster of genes encoding components of the botulinum neurotoxin (BoNT) complex was mapped in proteolytic (group I) Clostridium botulinum strains encoding BoNT types A, B, and F. Two different arrangements of genes were found: type A strain 62A and type B strain NCTC 7273 have similar organizations of genes encoding BoNT, the nontoxic nonhemagglutinin component (NTNH), hemagglutinin components, and P-21; type F strain Langeland has genes encoding BoNT, NTNH, and P-21, and a previously unidentified open reading frame encoding a protein of 416 amino acids. A group of type A strains typified by infant strain Kyoto-F, which is unlike type A strain 62A, lacks genes for hemagglutinin components and exhibits an organization similar to that of type F. Sequencing and pairwise analysis revealed the presence of possible chimeric sequences in some NTNH genes of proteolytic C. botulinum. Discordance in genealogical trees derived from different regions of the NTNH genes was observed which could be symptomatic of recombination and which may indicate that the NTNH gene represents a hot spot for such events within the cluster of genes encoding the BoNT complex. It is also evident that the phylogenetics of the NTNH gene, which is linked to the gene encoding BoNT, does not mirror the evolutionary history of the BoNT, upon which the C. botulinum species complex is defined and subdivided.


Asunto(s)
Toxinas Botulínicas/genética , Clostridium botulinum/genética , Genes Bacterianos , Familia de Multigenes , Secuencia de Aminoácidos , Secuencia de Bases , Datos de Secuencia Molecular , Sistemas de Lectura Abierta , Filogenia
14.
J Immunol ; 157(8): 3617-26, 1996 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-8871662

RESUMEN

As a member of the tetraspan family, it has been hypothesized that CD63 may be associated with signal transduction; however, its role in leukocyte function is unknown. To examine the potential ability of CD63 to activate neutrophils, the effects of five CD63 mAbs, AHN-16, -16.1, -16.2, -16.3, and -16.5, were examined for their ability to alter neutrophil adhesion to HUVEC monolayers. These CD63 Abs increased neutrophil adhesion to resting and TNF-stimulated HUVEC monolayers. This increase in neutrophil adhesion caused by CD63 Abs was blocked by a CD18 Ab and was associated with up-regulation of CD11/CD18 and down-regulation of CD62L on the neutrophil surface. CD11/CD18 was also found to be associated with CD63. This increase in neutrophil adhesion required physiologic extracellular calcium concentrations at or near the time of CD63 Ab binding. The incubation of CD63 Abs with cells in the absence of calcium for 10 min before repletion of calcium resulted in no increase in neutrophil adhesion. Protein kinase activity was detected in neutrophils associated with CD63. Most of the protein kinase activity associated with these Ags was tyrosine kinase activity, with a lesser amount of threonine and serine kinase activities. Src family kinases Lyn and Hck accounted for much of the associated tyrosine kinase activity. The data suggest that CD63 Ab binding to the neutrophil surface triggers a transient activation signal that requires extracellular calcium and regulates the adhesive activity of CD11/CD18. Associated protein kinase activity may play a role in signal transduction by CD63 to regulate other cell functions.


Asunto(s)
Antígenos CD/metabolismo , Antígenos CD11/metabolismo , Antígenos CD18/metabolismo , Neutrófilos/enzimología , Neutrófilos/inmunología , Glicoproteínas de Membrana Plaquetaria/metabolismo , Proteínas Tirosina Quinasas/metabolismo , Animales , Anticuerpos Monoclonales/farmacología , Antígenos CD/inmunología , Antígenos CD/farmacología , Calcio/farmacología , Adhesión Celular , Agregación Celular , Células Cultivadas , Regulación hacia Abajo , Endotelio Vascular/citología , Granulocitos/citología , Granulocitos/inmunología , Humanos , Técnicas In Vitro , Ratones , Neutrófilos/citología , Glicoproteínas de Membrana Plaquetaria/inmunología , Glicoproteínas de Membrana Plaquetaria/farmacología , Transducción de Señal , Tetraspanina 30 , Regulación hacia Arriba
15.
J Leukoc Biol ; 60(1): 106-17, 1996 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-8699114

RESUMEN

Four members of the carcinoembryonic antigen family, CD66a, CD66b, CD66c, and CD66d, are expressed on human neutrophils. In neutrophils these proteins are activation antigens in that their surface expression is increased following stimulation. To examine their potential role in neutrophil signaling, the effects on neutrophil adhesion to human umbilical vein endothelial cells of a panel of well-characterized CD66 mAbs was tested. CD66a, CD66b, CD66c, and CD66d antibodies each increased neutrophil adhesion to human umbilical vein endothelial cell monolayers. This increase in neutrophil adhesion caused by CD66 antibodies was blocked by a CD18 antibody and associated with up-regulation of CD11/CD18 on the neutrophil surface. This increase in neutrophil adhesion required physiological extracellular calcium concentrations at or near the time of CD66 antibody binding to the neutrophil. The incubation of CD66 antibodies with neutrophils in the absence of calcium for 10 min before repletion of calcium resulted in no increase in neutrophil adhesion. The data suggest that CD66a, CD66b, CD66c, and CD66d antibody binding to the neutrophil surface triggers a transient activation signal that requires extracellular calcium and regulates the adhesive activity of CD11/CD18. Sequential desensitization experiments indicated that CD66a, CD66b, CD66c, and CD66d can each independently transmit signals in neutrophils.


Asunto(s)
Antígenos CD/fisiología , Antígenos de Diferenciación/fisiología , Antígenos de Neoplasias , Antígeno Carcinoembrionario/fisiología , Moléculas de Adhesión Celular , Glicoproteínas de Membrana/fisiología , Neutrófilos/fisiología , Anticuerpos Monoclonales/farmacología , Especificidad de Anticuerpos , Antígenos CD/inmunología , Antígenos de Diferenciación/inmunología , Antígenos CD18/inmunología , Antígenos CD18/fisiología , Calcio/farmacología , Antígeno Carcinoembrionario/inmunología , Adhesión Celular/efectos de los fármacos , Células Cultivadas , Endotelio Vascular/fisiología , Proteínas Ligadas a GPI , Humanos , Fragmentos Fab de Inmunoglobulinas , Antígeno de Macrófago-1/inmunología , Antígeno de Macrófago-1/fisiología , Glicoproteínas de Membrana/inmunología , N-Formilmetionina Leucil-Fenilalanina/farmacología , Neutrófilos/efectos de los fármacos , Factor de Necrosis Tumoral alfa/farmacología , Venas Umbilicales
16.
J Immunol ; 155(11): 5382-90, 1995 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-7594554

RESUMEN

The granulocyte activation Ags, CD66a, CD66b, CD66c, and CD66d, are expressed at low levels on resting blood granulocytes, but their surface expression is up-regulated following stimulation. CD66a, in contrast to CD66b and CD66c which are anchored to the membrane via a glycosyl-phosphatidylinositol linkage, is a transmembrane protein with a cytoplasmic domain. We have previously reported that CD66a is phosphorylated in human neutrophils, largely on tyrosine, with a lower level of phosphoserine. We have now found that CD66a undergoes a rapid increase in phosphorylation following stimulation with FMLP, platelet-activating factor, and 12-O-tetradecanoyl-phorbol-13-acetate. This increase in phosphorylation was transient, with maximal phosphorylation observed by 1 min and a return to base line by 5 min following stimulation. Protein kinase activity was detected in neutrophils associated with CD66a, CD66b, and CD66c. Most of the protein kinase activity associated with these Ags was tyrosine kinase activity, with a lesser amount of threonine and serine kinase activities. Lyn and Hck accounted for much of the associated tyrosine kinase activity. The data suggest that phosphorylation of CD66a on tyrosine by an associated tyrosine kinase may play a role in the function of CD66a. In addition, associated tyrosine kinase activity may play a role in signal transduction from CD66a, CD66b, and CD66c to regulate other cell functions.


Asunto(s)
Antígenos CD/metabolismo , Antígenos de Diferenciación/metabolismo , Neutrófilos/enzimología , Proteínas Tirosina Quinasas/metabolismo , Moléculas de Adhesión Celular , Humanos , N-Formilmetionina Leucil-Fenilalanina/farmacología , Neutrófilos/efectos de los fármacos , Fosforilación/efectos de los fármacos , Factor de Activación Plaquetaria/farmacología , Proteínas Proto-Oncogénicas/metabolismo , Proteínas Proto-Oncogénicas c-hck , Transducción de Señal , Acetato de Tetradecanoilforbol/farmacología , Familia-src Quinasas/metabolismo
17.
Nature ; 378(6558): 658, 1995 Dec 14.
Artículo en Inglés | MEDLINE | ID: mdl-7501005
18.
J Immunol ; 154(6): 2888-95, 1995 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-7876557

RESUMEN

CD50 (ICAM-3) is expressed at a high level on resting blood granulocytes, monocytes, and lymphocytes. The constitutive high expression of CD50 on resting leukocytes suggests that it is an important LFA-1 ligand in the initiation of the immune/inflammatory response. Using a radiolabeling technique initially designed to detect ecto-protein kinase activity, we found that CD50 mAbs immunoprecipitated a approximately 125- to 170-kDa phosphoprotein from human neutrophils. Phosphorylation was increased after stimulation with the chemotactic agent FMLP, platelet-activating factor, 12-O-tetradecanoyl-phorbol-13-acetate, and the calcium ionophore A23187. This increase in phosphorylation was transient with the maximal phosphorylation, being observed by 1 min. Phosphoamino acid analysis revealed that CD50 contained predominantly phosphotyrosine. Although this assay system was designed initially to detect ecto-protein kinase activity, subsequent studies have shown that membrane proteins can be phosphorylated on the cytoplasmic domain under these conditions. When CD50 was immunoprecipitated from solubilized neutrophils, protein tyrosine kinase activity associated with CD50 was detected in the immunoprecipitate. The data suggest that phosphorylation of CD50 on tyrosine by an associated tyrosine kinase plays a role in the function of CD50.


Asunto(s)
Antígenos CD , Antígenos de Diferenciación , Moléculas de Adhesión Celular/metabolismo , Neutrófilos/enzimología , Neutrófilos/inmunología , Proteínas Tirosina Quinasas/sangre , Electroforesis en Gel de Poliacrilamida , Humanos , Activación Neutrófila/fisiología , Pruebas de Precipitina , Regulación hacia Arriba/fisiología
19.
J Urol ; 152(2 Pt 2): 593-5, 1994 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8021976

RESUMEN

During the last 5 years we have followed nonoperatively all neonates with unilateral hydronephrosis and suspected ureteropelvic junction obstruction, regardless of the degree of hydronephrosis, shape of the diuretic renogram washout curve or initial degree of functional impairment. Of 104 patients 7 (7%) ultimately required pyeloplasty for obstruction, which was defined as a greater than 10% reduction in differential glomerular filtration rate and/or progression of hydronephrosis. Pyeloplasty returned renal function to pre-deterioration levels in all kidneys. In 16 patients with profound hydronephrosis and initial differential renal function less than or equal to 40% all traditional diagnostic tests for assessing obstruction, including diuretic renography washout pattern, were inaccurate in diagnosing obstruction and predicting which kidney would deteriorate. In 15 of 16 poorly functioning hydronephrotic kidneys rapid improvement in absolute and per cent differential renal function was observed, and the level of initial differential renal function served as a useful guide for timing of further diagnostic studies. Unilateral neonatal hydronephrosis appears to be a relatively benign condition and the risk of developing renal obstruction appears relatively slight. Because of diagnostic inaccuracy, the low risk of developing obstructive injury and the fact that many newborn kidneys with hydronephrosis rapidly improve function and dilation, it appears safe to follow neonatal unilateral hydronephrosis closely and nonoperatively.


Asunto(s)
Hidronefrosis/terapia , Riñón/fisiopatología , Estudios de Seguimiento , Humanos , Hidronefrosis/diagnóstico por imagen , Hidronefrosis/fisiopatología , Recién Nacido , Riñón/diagnóstico por imagen , Renografía por Radioisótopo
20.
Med Sci Sports Exerc ; 26(4): 463-8, 1994 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-8201903

RESUMEN

The purpose of this study was to determine the effect lower body positive pressure (LBPP) has on the cardiovascular/exercise capacities of individuals with spinal cord injury (SCI) during both arm crank exercise (ACE) and wheelchair exercise performed on a treadmill (WCTM). Ten male adults (age = 31.1 +/- 10 yr) with SCI and five male nondisabled (ND) adults (31.2 +/- 10 yr) participated in this study. The ND subjects performed ACE only. For subjects with SCI, significantly higher (P < 0.025) peak VO2 (1042 +/- 212 vs 839 +/- 218 ml.min-1), peak VE (46 +/- 17 vs 35 +/- 9 l.min-1), and work rate (50 +/- 15 vs 40 +/- 13 W) were seen during ACE with LBPP. No significant differences for peak VO2, VE, or work rate were seen for the ND subjects with LBPP during ACE. In addition, significantly higher peak VO2 (960 +/- 322 vs 828 +/- 312 ml.min-1) was recorded with LBPP for the subjects with SCI during WCTM. Cardiac output (Q, l.min-1; CO2 rebreathing method) was measured at 50% peak VO2 for both ND subjects and subjects with SCI during ACE. Subjects with SCI demonstrated significantly higher SV (94 +/- 20 vs 84 +/- 20 ml) with LBPP. No differences were observed in SV at 50% peak VO2 during ACE for the ND subjects with LBPP. The results of this study suggest that for individuals with SCI, LBPP augments exercise capacity by preventing the redistribution of blood to the lower extremities.


Asunto(s)
Tolerancia al Ejercicio/fisiología , Trajes Gravitatorios , Traumatismos de la Médula Espinal/fisiopatología , Adolescente , Adulto , Brazo/fisiología , Presión Sanguínea/fisiología , Dióxido de Carbono/análisis , Gasto Cardíaco/fisiología , Prueba de Esfuerzo , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Persona de Mediana Edad , Consumo de Oxígeno/fisiología , Paraplejía/fisiopatología , Presión , Cuadriplejía/fisiopatología , Respiración/fisiología , Volumen Sistólico/fisiología , Volumen de Ventilación Pulmonar/fisiología
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