RESUMEN

Using combined data from the Relativistic Heavy Ion and Large Hadron Colliders, we constrain the shear and bulk viscosities of quark-gluon plasma (QGP) at temperatures of ∼150-350 MeV. We use Bayesian inference to translate experimental and theoretical uncertainties into probabilistic constraints for the viscosities. With Bayesian model averaging we propagate an estimate of the model uncertainty generated by the transition from hydrodynamics to hadron transport in the plasma's final evolution stage, providing the most reliable phenomenological constraints to date on the QGP viscosities.

RESUMEN

Levels of reactive free radicals are elevated in the airway during asthmatic exacerbations, but their roles in the pathophysiology of asthma remain unclear. We have identified subsets of myeloid-derived suppressor-like cells as key sources of nitric oxide and superoxide in the lungs of mice with evolving experimental allergic airway inflammation and established these cells as master regulators of the airway inflammatory response. The profiles of free radicals they produced depended on expression of inducible nitric oxide synthase (iNOS), arginase, and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase. These radicals controlled the pro- and anti-inflammatory potential of these cells, and also regulated the reciprocal pattern of their infiltration into the lung. The nitric oxide-producing cells were Ly-6C(+)Ly-6G(-) and they downmodulated T-cell activation, recruited T(reg) cells, and dramatically downregulated antigen-induced airway hyperresponsiveness. The superoxide-producing cells were Ly-6C(-)Ly-6G(+) and they expressed proinflammatory activities, exacerbating airway hyperresponsiveness in a superoxide-dependent fashion. A smaller population of Ly-6C(+)Ly-6G(+) cells also suppressed T-cell responses, but in an iNOS- and arginase-independent fashion. These regulatory myeloid cells represent important targets for asthma therapy.

Asunto(s)

Hiperreactividad Bronquial/inmunología , Radicales Libres/metabolismo , Células Mieloides/inmunología , Neumonía/inmunología , Traslado Adoptivo , Animales , Arginasa/metabolismo , Asma/inmunología , Asma/metabolismo , Hiperreactividad Bronquial/metabolismo , Quimiocina CCL22/metabolismo , Pulmón/inmunología , Pulmón/patología , Activación de Linfocitos/inmunología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Células Mieloides/metabolismo , Células Mieloides/patología , NADPH Oxidasas/metabolismo , Óxido Nítrico Sintasa de Tipo II/metabolismo , Neumonía/metabolismo , Transducción de Señal/inmunología , Linfocitos T/inmunología , Linfocitos T/metabolismo

Asunto(s)

Anticoagulantes/administración & dosificación , Aspirina/administración & dosificación , Insuficiencia Cardíaca/fisiopatología , Volumen Sistólico , Trombofilia/prevención & control , Función Ventricular Izquierda , Warfarina/administración & dosificación , Medicina Basada en la Evidencia , Femenino , Insuficiencia Cardíaca/complicaciones , Humanos , Masculino , Metaanálisis como Asunto , Persona de Mediana Edad , Infarto del Miocardio/prevención & control , Ensayos Clínicos Controlados Aleatorios como Asunto , Accidente Cerebrovascular/etiología , Accidente Cerebrovascular/prevención & control , Trombofilia/etiología

RESUMEN

These studies provide evidence that cystic fibrosis transmembrane conductance regulator (CFTR) potentiates and accelerates regulatory volume decrease (RVD) following hypotonic challenge by an autocrine mechanism involving ATP release and signaling. In wild-type CFTR-expressing cells, CFTR augments constitutive ATP release and enhances ATP release stimulated by hypotonic challenge. CFTR itself does not appear to conduct ATP. Instead, ATP is released by a separate channel, whose activity is potentiated by CFTR. Blockade of ATP release by ion channel blocking drugs, gadolinium chloride (Gd(3+)) and 4,4'-diisothiocyanatostilbene-2,2'disulfonic acid (DIDS), attenuated the effects of CFTR on acceleration and potentiation of RVD. These results support a key role for extracellular ATP and autocrine and paracrine purinergic signaling in the regulation of membrane ion permeability and suggest that CFTR potentiates ATP release by stimulating a separate ATP channel to strengthen autocrine control of cell volume regulation.

Asunto(s)

Adenosina Trifosfato/metabolismo , Tamaño de la Célula , Regulador de Conductancia de Transmembrana de Fibrosis Quística/fisiología , Ácido 4,4'-Diisotiocianostilbeno-2,2'-Disulfónico/farmacología , Animales , Células COS , Canales de Cloruro/fisiología , Gadolinio/farmacología

RESUMEN

Culturing airway epithelial cells with most of the apical media removed (air-liquid interface) has been shown to enhance cystic fibrosis transmembrane conductance regulator (CFTR)-mediated Cl(-) secretory current. Thus we hypothesized that cellular oxygenation may modulate CFTR expression. We tested this notion using type I Madin-Darby canine kidney cells that endogenously express low levels of CFTR. Growing monolayers of these cells for 4 to 5 days with an air-liquid interface caused a 50-fold increase in forskolin-stimulated Cl(-) current, compared with conventional (submerged) controls. Assaying for possible changes in CFTR by immunoprecipitation and immunocytochemical localization revealed that CFTR appeared as an immature 140-kDa form intracellularly in conventional cultures. In contrast, monolayers grown with an air-liquid interface possessed more CFTR protein, accompanied by increases toward the mature 170-kDa form and apical membrane staining. Culturing submerged monolayers with 95% O(2) produced similar improvements in Cl(-) current and CFTR protein as air-liquid interface culture, while increasing PO(2) from 2.5% to 20% in air-liquid interface cultures yielded graded enhancements. Together, our data indicate that improved cellular oxygenation can increase endogenous CFTR maturation and/or trafficking.

Asunto(s)

Diferenciación Celular/efectos de los fármacos , Células Cultivadas/metabolismo , Regulador de Conductancia de Transmembrana de Fibrosis Quística/metabolismo , Oxígeno/farmacología , Transporte de Proteínas/fisiología , Animales , Técnicas de Cultivo de Célula/métodos , Diferenciación Celular/fisiología , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Polaridad Celular/efectos de los fármacos , Polaridad Celular/fisiología , Células Cultivadas/citología , Células Cultivadas/efectos de los fármacos , Colforsina/metabolismo , Colforsina/farmacología , Medios de Cultivo/farmacología , Fibrosis Quística/metabolismo , Fibrosis Quística/patología , Fibrosis Quística/fisiopatología , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Perros , Hipoxia/metabolismo , Hipoxia/patología , Hipoxia/fisiopatología , ARN Mensajero/metabolismo

RESUMEN

Cytokines produced by activated macrophages and Th2 cells within the lung play a key role in asthma-associated airway inflammation. Additionally, recent studies suggest that the molecule CD40 modulates lung immune responses. Because airway epithelial cells can act as immune effector cells through the expression of inflammatory mediators, the epithelium is now considered important in the generation of asthma-associated inflammation. Therefore, the goal of the present study was to examine the effects of proinflammatory and Th2-derived cytokines on the function of CD40 in airway epithelia. The results show that airway epithelial cells express CD40 and that engagement of epithelial CD40 induces a significant increase in expression of the chemokines RANTES, monocyte chemoattractant protein (MCP-1), and IL-8 and the adhesion molecule ICAM-1. Cross-linking epithelial CD40 had no effect on expression of the adhesion molecule VCAM-1. The proinflammatory cytokines TNF-alpha and IL-1beta and the Th2-derived cytokines IL-4 and IL-13 modulated the positive effects of CD40 engagement on inflammatory mediator expression in airway epithelial cells. Importantly, CD40 ligation enhanced the sensitivity of airway epithelial cells to the effects of TNF-alpha and/or IL-1beta on expression of RANTES, MCP-1, IL-8, and VCAM-1. In contrast, neither IL-4 nor IL-13 modified the effects of CD40 engagement on the expression of RANTES, MCP-1, IL-8, or VCAM-1; however, both IL-4 and IL-13 attenuated the effects of CD40 cross-linking on ICAM-1 expression. Together, these findings suggest that interactions between CD40-responsive airway epithelial cells and CD40 ligand+ leukocytes, such as activated T cells, eosinophils, and mast cells, modulate asthma-associated airway inflammation.

Asunto(s)

Adyuvantes Inmunológicos/fisiología , Bronquios/inmunología , Bronquios/patología , Antígenos CD40/fisiología , Citocinas/fisiología , Mediadores de Inflamación/metabolismo , Células Th2/inmunología , Células Th2/metabolismo , Animales , Bronquios/metabolismo , Antígenos CD40/biosíntesis , Moléculas de Adhesión Celular/biosíntesis , Línea Celular , Quimiocinas/biosíntesis , Células Epiteliales/inmunología , Células Epiteliales/metabolismo , Epitelio/inmunología , Epitelio/metabolismo , Epitelio/patología , Humanos , Inflamación/inmunología , Inflamación/metabolismo , Mediadores de Inflamación/inmunología , Proteínas de la Membrana/biosíntesis , Ratones , Ratones Endogámicos BALB C

RESUMEN

Airway epithelial cells (ECs) form a continuous pseudostratified layer in the lung, creating a tight barrier that protects underlying tissue from the external environment. As such, airway ECs have been described classically as barrier cells that are involved in homeostasis; these cells respond to a variety of environmental stimuli, resulting in the alteration of their cellular functions, such as ion transport and movement of airway secretions. Recent evidence, however, suggests that airway ECs may also act as immune-effector cells, in response to noxious endogenous or exogenous stimuli. Several studies have shown that airway ECs express and secrete various immune molecules, such as lipid mediators, oxygen radicals, adhesion molecules, and a wide variety of cytokines, including chemokines (1). Through the expression and production of these immune molecules, the epithelium is now thought to be important in the initiation and exacerbation of inflammatory diseases of the lung, such as asthma.

RESUMEN

P2X purinergic receptor (P2XR) channels bind ATP and mediate Ca(2+) influx--2 signals that stimulate secretory Cl(-) transport across epithelia. We tested the hypotheses that P2XR channels are expressed by epithelia and that P2XRs transduce extracellular ATP signals into stimulation of Cl(-) transport across epithelia. Electrophysiological data and mRNA analysis of human and mouse pulmonary epithelia and other epithelial cells indicate that multiple P2XRs are broadly expressed in these tissues and that they are active on both apical and basolateral surfaces. Because P2X-selective agonists bind multiple P2XR subtypes, and because P2X agonists stimulate Cl(-) transport across nasal mucosa of cystic fibrosis (CF) patients as well as across non-CF nasal mucosa, P2XRs may provide novel targets for extracellular nucleotide therapy of CF.

Asunto(s)

Células Epiteliales/fisiología , Pulmón/fisiología , Receptores Purinérgicos P2/genética , Receptores Purinérgicos P2/fisiología , Ácido 4,4'-Diisotiocianostilbeno-2,2'-Disulfónico/farmacología , Amilorida/farmacología , Animales , Secuencia de Bases , Bumetanida/farmacología , Línea Celular , Células Cultivadas , Sondas de ADN , ADN Complementario , Células Epiteliales/efectos de los fármacos , Humanos , Mucosa Intestinal/fisiología , Hígado/fisiología , Ratones , Modelos Biológicos , Datos de Secuencia Molecular , Páncreas/fisiología , Técnicas de Placa-Clamp , Isoformas de Proteínas/genética , Isoformas de Proteínas/fisiología , ARN Mensajero/metabolismo , Mucosa Respiratoria/fisiología , Alineación de Secuencia , Homología de Secuencia de Ácido Nucleico , Transcripción Genética

RESUMEN

Extracellular nucleotides regulate NaCl transport in some epithelia. However, the effects of nucleotide agonists on NaCl transport in the renal inner medullary collecting duct (IMCD) are not known. The objective of this study was to determine whether ATP and related nucleotides regulate NaCl transport across mouse IMCD cell line (mIMCD-K2) epithelial monolayers and, if so, via what purinergic receptor subtypes. ATP and UTP inhibited Na(+) absorption [measured via Na(+) short-circuit current (I(Na)(sc))] and stimulated Cl(-) secretion [measured via Cl(-) short-circuit current (I(Cl)(sc))]. Using selective P2 agonists, we report that P2X and P2Y purinoceptors regulate I(Na)(sc) and I(Cl)(sc). By RT-PCR, two P2X receptor channels (P2X(3), P2X(4)) and two P2Y G protein-coupled receptors (P2Y(1), P2Y(2)) were identified. Functional localization of P2 purinoceptors suggest that I(Cl)(sc) is stimulated by apical membrane-resident P2Y purinoceptors and P2X receptor channels, whereas I(Na)(sc) is inhibited by apical membrane-resident P2Y purinoceptors and P2X receptor channels. Together, we conclude that nucleotide agonists inhibit I(Na)(sc) across mIMCD-K2 monolayers through interactions with P2X and P2Y purinoceptors expressed on the apical plasma membrane, whereas extracellular nucleotides stimulate I(Cl)(sc) through interactions with P2X and P2Y purinoceptors expressed on the apical plasma membrane.

Asunto(s)

Túbulos Renales Colectores/metabolismo , Nucleótidos/fisiología , Receptores Purinérgicos P2/fisiología , Cloruro de Sodio/metabolismo , Animales , Secuencia de Bases/genética , Transporte Biológico/fisiología , Línea Celular , Cloruros/metabolismo , Cloruros/fisiología , Conductividad Eléctrica , Médula Renal , Túbulos Renales Colectores/citología , Ratones , Datos de Secuencia Molecular , Receptores Purinérgicos P2/genética , Sodio/metabolismo , Sodio/fisiología

RESUMEN

Chemokines constitute a large family of secreted proteins that function as chemoattractants and activators of leukocytes. Astrocytes, the major glial cell type in the central nervous system (CNS), are a source of chemokine production within diseased brain. As such, we have examined the production of chemokines by human astroglioma cell lines and primary human astrocytes treated with a variety of stimuli, including LPS, TNF-alpha, IFN-gamma and IL-1beta. In addition, IL-6 in conjunction with the soluble IL-6 receptor (sIL-6R), and hybrid IL-6 (H-IL-6), a highly active fusion protein of sIL-6R and IL-6, were tested for their ability to induce chemokine expression. The findings presented herein demonstrate that both human astroglioma cell lines and primary human astrocytes express the CXC chemokines IP-10 and IL-8 and the CC chemokines MCP-1 and RANTES in response to TNF-alpha and IL-1beta. IFN-gamma induced the expression of IP-10, but not of IL-8, MCP-1 or RANTES. Surprisingly, IL-6/sIL-6R and H-IL-6 had little or no effect on chemokine expression in these cells. The effect of TGF-beta on chemokine expression in human astroglioma cell lines and astrocytes was also examined. TGF-beta alone had little or no effect on RANTES, MCP-1 and IL-8 expression; however, TGF-beta synergized with TNF-alpha to enhance MCP-1 expression in both astroglioma cells and primary astrocytes. An inhibitory effect of TGF-beta on TNF-alpha and IL-1beta induced RANTES and IL-8 expression was observed in human astroglioma cells. In contrast, TGF-beta enhanced TNF-alpha and IL-1beta induction ofIL-8 production by human astrocytes. These findings document a complex pattern of chemokine regulation by the pleiotropic cytokine TGF-beta with both enhancing and inhibitory effects.

Asunto(s)

Astrocitos/metabolismo , Quimiocinas/metabolismo , Astrocitos/efectos de los fármacos , Quimiocina CCL2/metabolismo , Quimiocina CCL5/metabolismo , Quimiocina CXCL10 , Quimiocinas/genética , Quimiocinas CXC/metabolismo , Citocinas/farmacología , Humanos , Interferón gamma/metabolismo , Interleucina-1/metabolismo , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Lipopolisacáridos/metabolismo , ARN Mensajero/metabolismo , Receptores de Interleucina-6/metabolismo , Células Tumorales Cultivadas , Factor de Necrosis Tumoral alfa/metabolismo

RESUMEN

To delineate the mechanisms that facilitate leukocyte migration into the cystic fibrosis (CF) lung, expression of chemokines, including interleukin-8 (IL-8), monocyte chemoattractant protein-1 (MCP-1), and RANTES, was compared between CF and non-CF airway epithelia. The findings presented herein demonstrate that, under either basal conditions or tumor necrosis factor-alpha (TNF-alpha)- and/or interferon-gamma (IFN-gamma)-stimulated conditions, a consistent pattern of differences in the secretion of IL-8 and MCP-1 between CF and non-CF epithelial cells was not observed. In contrast, CF epithelial cells expressed no detectable RANTES protein or mRNA under basal conditions or when stimulated with TNF-alpha and/or IFN-gamma (P

Asunto(s)

Bronquios/metabolismo , Quimiocina CCL5/metabolismo , Quimiocinas/metabolismo , Regulador de Conductancia de Transmembrana de Fibrosis Quística/fisiología , Fibrosis Quística/metabolismo , Bronquios/efectos de los fármacos , Bronquios/patología , Quimiocina CCL2/metabolismo , Quimiocina CCL5/genética , Combinación de Medicamentos , Células Epiteliales/efectos de los fármacos , Células Epiteliales/metabolismo , Humanos , Interferón gamma/farmacología , Interleucina-8/metabolismo , Neoplasias Pancreáticas/metabolismo , Neoplasias Pancreáticas/patología , Regiones Promotoras Genéticas/fisiología , ARN Mensajero/metabolismo , Células Tumorales Cultivadas , Factor de Necrosis Tumoral alfa/farmacología

RESUMEN

BACKGROUND AND OBJECTIVES: Despite the increased prominence of family medicine clerkships in required third- and fourth-year clinical rotations in US allopathic medical schools, the content of these clerkships varies markedly among institutions, and there is little in the literature concerning the current or desired content of family medicine clerkships. This study explores the didactic content of a national sample of required family medicine clerkships to assess what and how this important aspect of clerkship curriculum is taught. METHODS: Using an original survey instrument, we surveyed US medical schools through mailings and follow-up phone contacts. We categorized free-form responses using a coding dictionary specific to this study and computed descriptive statistics. RESULTS: Of 127 medical schools contacted, 105 (83%) responded. Among respondents, 86 (82%) had a required family medicine clerkship, 80% of them in the third year. Mean clerkship length was 5.3 weeks (median = 4 weeks), and the mean number of didactic sessions was about 2 per week. Almost 80% of clerkships had sessions in the broad area of family medicine, and prevention was the most frequent individual topic, taught in 32 (37%) of clerkships. Seventy-one percent of sessions used methodologies other than lectures. The mean time devoted to teaching 24 of the top 26 topics identified in the survey was between 1.2 and 3.1 hours/rotation, although case presentations and common problems each averaged more than 7 hours on clerkships teaching these topics. CONCLUSIONS: This survey provided more detailed information than previously available about the didactic content of required US allopathic family medicine clerkships. The survey also documented the lack of agreement among these clerkships on didactic content. Most didactic sessions used interactive rather than lecture format. The information from this first detailed survey provides family medicine clerkship directors with national comparisons of didactic content and methodology as a foundation for further discussion.

Asunto(s)

Prácticas Clínicas/métodos , Curriculum , Medicina Familiar y Comunitaria/educación , Enseñanza/métodos , Recolección de Datos , Humanos , Facultades de Medicina , Estados Unidos

RESUMEN

The cystic fibrosis transmembrane conductance regulator (CFTR) functions as a low-conductance, cAMP-regulated chloride (Cl-) channel in a variety of cell types, such as exocrine epithelial cells. Our results demonstrate that human primary endothelial cells isolated from umbilical vein (HUVEC) and lung microvasculature (HLMVEC) also express CFTR as determined via RT-PCR and immunohistochemical and immunoprecipitation analyses. Moreover, Cl- efflux and whole cell patch-clamp analyses reveal that HUVEC (n = 6 samples, P < 0.05) and HLMVEC (n = 5 samples, P < 0.05) display cyclic nucleotide-stimulated Cl- transport that is inhibited by the CFTR selective Cl- channel blocker glibenclamide but not by the blocker DIDS, indicative of CFTR Cl- channel activity. Taken together, these findings demonstrate that human endothelial cells derived from multiple organ systems express CFTR and that CFTR functions as a cyclic nucleotide-regulated Cl- channel in human endothelia.

Asunto(s)

Canales de Cloruro/fisiología , Regulador de Conductancia de Transmembrana de Fibrosis Quística/metabolismo , Endotelio Vascular/metabolismo , Secuencia de Bases , Células Cultivadas , Regulador de Conductancia de Transmembrana de Fibrosis Quística/genética , Regulador de Conductancia de Transmembrana de Fibrosis Quística/fisiología , Endotelio Vascular/citología , Endotelio Vascular/efectos de los fármacos , Humanos , Inmunohistoquímica , Microcirculación/fisiología , Datos de Secuencia Molecular , Nucleótidos Cíclicos/farmacología , Técnicas de Placa-Clamp , Pruebas de Precipitina , Circulación Pulmonar/fisiología , ARN Mensajero/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Venas Umbilicales/citología , Venas Umbilicales/metabolismo

RESUMEN

Airway epithelium may actively participate in inflammatory responses, such as occur in asthma. The presence and regulation of surface molecules on the airway epithelium, however, is incompletely understood. We have determined the phenotype of the human bronchial epithelial cell line BEAS-2B by flow cytometry. We confirmed previous observations that human bronchial epithelial cells constitutively express CD29, CD44, CD49a, CD49b, CD49c, CD49d, CD49e, CD49f, CD51, CD54 (ICAM-1), CD61, and HLA class 1. BEAS-2B cells were also found to constitutively express CD9, CD13, CD15, CD15s, CD23, CD33, CD36, CD40, CD41b, CD42b, CD48, CD50, CD71, and CD102 (ICAM-2). Culture of BEAS-2B cells with tumor necrosis factor (TNF)-alpha or interleukin (IL)-1beta (1 ng/ml) was found to enhance intercellular adhesion molecule-1 (ICAM-1) expression (several fold) and induce de novo CD106 [vascular cell adhesion molecule-1 (VCAM-1)] expression. TNF-alpha or IL-1beta did not change the expression of CD9, CD13, CD16, CD23, CD29, CD31, CD32, CD35, CD45, CD61, or CD64 in BEAS-2B cells. IL-4 (1 ng/ml) also induced expression of VCAM-1 (1.5-fold) but not ICAM- expression while interferon-gamma (1 ng/ml) enhanced only ICAM-1 expression (2-fold). Maximal VCAM-1 expression was obtained with the combination of TNF-alpha and IL-4 (8-fold). Using Northern blot hybridization analysis, ICAM-1 and VCAM-1 mRNA was detected in BEAS-2B cells stimulated with cytokines. VCAM-1 on stimulated BEAS-2B was functionally active as determined by adhesion of purified eosinophils and blockade with specific antibodies. Primary isolates of bronchial epithelial cells produced detectable levels of VCAM-1 protein and mRNA as detected by enzyme-linked immunosorbent assay and reverse transcription-polymerase chain reaction, respectively. These results suggest that cytokine activation induces expression of ICAM-1 and VCAM-1 on airway epithelium, an event which may influence leukocyte infiltration and activation.

Asunto(s)

Antígenos CD/inmunología , Bronquios/citología , Células Epiteliales/citología , Células Epiteliales/inmunología , Molécula 1 de Adhesión Intercelular/biosíntesis , Interleucina-1/farmacología , Factor de Necrosis Tumoral alfa/farmacología , Molécula 1 de Adhesión Celular Vascular/biosíntesis , Bronquios/inmunología , Adhesión Celular/efectos de los fármacos , Línea Celular , Eosinófilos/citología , Humanos , Inmunofenotipificación

RESUMEN

DNA differential display analysis (DD-PCR) was utilized to identify genes that are expressed in airway epithelium and are relevant to airway inflammation; cytokine-mediated induction of gene expression and inhibition of that induction by glucocorticoids were the criteria for selection. The IB3-1 cell line was cultured in the presence of tumor necrosis factor-alpha (TNF-alpha), dexamethasone, or dimethyl sulfoxide (DMSO) as a control, and analyzed via DD-PCR and Northern blot analyses. With this approach, two TNF-alpha-inducible and dexamethasone (DEX)-sensitive expressed sequence tags (EST8 and EST19) were identified. In IB3-1 cells, TNF-alpha increased messenger RNA (mRNA) expression of EST8 (34%, P < or = 0.005) and EST19 (41%, P < or = 0.01), whereas dexamethasone reduced this expression to resting levels. This pattern of mRNA expression was also observed in normal human bronchial epithelial cells (EST8: 21%, P < or = 0.009; EST19: 11%, P < or = 0.02) and in the basophil leukemia cell line KU812 (EST8: 34%, P < or = 0.01). Through basic local alignment search tool (BLAST) analysis, it was determined that these ESTs exhibited significant homology with the monomeric G protein rhoC (EST8: 100% homology, P = 1.6 x 10(-100)) and the UFO tyrosine kinase receptor (EST19: 86% homology, 5.3 x 10(-28).

Asunto(s)

Bronquios/metabolismo , ADN , Expresión Génica , Reacción en Cadena de la Polimerasa/métodos , Transcripción Genética , Secuencia de Bases , Línea Celular , Clonación Molecular , Citocinas/farmacología , Presentación de Datos , Dexametasona/farmacología , Dimetilsulfóxido/farmacología , Epitelio/metabolismo , Expresión Génica/efectos de los fármacos , Glucocorticoides/farmacología , Humanos , Inflamación , Datos de Secuencia Molecular , ARN Mensajero/biosíntesis , Alineación de Secuencia , Homología de Secuencia de Ácido Nucleico , Lugares Marcados de Secuencia , Transcripción Genética/efectos de los fármacos , Células Tumorales Cultivadas , Factor de Necrosis Tumoral alfa/farmacología

RESUMEN

Multiple major histocompatibility complex (MHC) alleles exist at most class I and II loci. Polymorphism of MHC polypeptides may reflect either different levels of selective pressure operating on each molecule or different mutation rates at different loci. To gain further insight into this issue, we sequenced the non-coding promoter region of the HLA-DRA gene from several Epstein-Barr virus-transformed B cell lines and compared the extent of polymorphism found in this region with the known polymorphism of the HLA-DQB promoter. Our results indicate that the HLA-DRA promoter displays a low level of polymorphism while the promoter of HLA-DQB exhibits a nucleotide substitution rate fivefold greater than that of DRA. Moreover, through phylogenetic analysis, the HLA-DRA promoter was found to have diverged much less than the associated alleles of HLA-DRB1 and -DQA1. Taken together, these results suggest that the HLA-DRA promoter is highly conserved and may be under a stronger functional constraint than the promoter regions of other MHC class II genes.

Asunto(s)

Antígenos HLA-DR/genética , Polimorfismo Genético , Regiones Promotoras Genéticas , Alelos , Línea Celular , Evolución Molecular , Ligamiento Genético , Variación Genética , Antígenos HLA-DQ/genética , Cadenas beta de HLA-DQ , Cadenas alfa de HLA-DR , Humanos , Alineación de Secuencia , Análisis de Secuencia de ADN

RESUMEN

Monocyte chemotactic protein-4 (MCP-4) is a newly identified C-C chemokine with potent eosinophil chemoattractant properties. We describe studies of its biological activity in vitro to induce chemotaxis of peripheral blood eosinophils and to induce histamine release from IL-3-primed peripheral blood basophils. MCP-4 and eotaxin caused a similar rise in eosinophil intracytoplasmic Ca2+ and complete cross-desensitization. MCP-4 also abolished the eosinophil Ca2+ response to MCP-3 and partially desensitized the response to macrophage inflammatory protein-1alpha. MCP-4 activated cell migration via either CCR2b or CCR3 in mouse lymphoma cells transfected with these chemokine receptors. MCP-4 inhibited binding of 125I-eotaxin to eosinophils and CCR3-transfected cells and inhibited 125I-MCP-1 binding to CCR2b-transfectants. MCP-4 mRNA was found in cells collected in bronchoalveolar lavage of asthmatic and nonasthmatic subjects and was prominently expressed in human lung and heart. MCP-4 mRNA was expressed in several human bronchial epithelial cell lines after cytokine stimulation. Pretreatment of BEAS-2B epithelial cells with the glucocorticoid budesonide inhibited MCP-4 mRNA expression. These features make MCP-4 a candidate for playing a role in eosinophil recruitment during allergic respiratory diseases.

Asunto(s)

Quimiocinas CC , Eosinófilos/metabolismo , Eosinófilos/fisiología , Proteínas Quimioatrayentes de Monocitos/metabolismo , Proteínas Quimioatrayentes de Monocitos/fisiología , Secuencia de Aminoácidos , Animales , Basófilos/inmunología , Basófilos/metabolismo , Northern Blotting , Líquido del Lavado Bronquioalveolar/citología , Budesonida , Calcio/metabolismo , Movimiento Celular , Células Cultivadas/metabolismo , Quimiocina CCL11 , Quimiocina CCL4 , Quimiocina CCL5/genética , Quimiocina CCL5/farmacología , Quimiocina CCL5/fisiología , Quimiocina CCL7 , Quimiotaxis , Citocinas/genética , Citocinas/farmacología , Citocinas/fisiología , ADN Complementario/análisis , Eosinófilos/inmunología , Células Epiteliales , Liberación de Histamina , Humanos , Interleucina-3/farmacología , Proteínas Inflamatorias de Macrófagos/farmacología , Ratones , Datos de Secuencia Molecular , Proteínas Quimioatrayentes de Monocitos/genética , Proteínas Quimioatrayentes de Monocitos/farmacología , Neutrófilos/inmunología , Neutrófilos/metabolismo , Reacción en Cadena de la Polimerasa , Pregnenodionas/farmacología , Unión Proteica/efectos de los fármacos , ARN Mensajero/metabolismo , Receptores de Superficie Celular/efectos de los fármacos , Receptores de Superficie Celular/fisiología , Homología de Secuencia de Aminoácido , Transfección , Células Tumorales Cultivadas/metabolismo

RESUMEN

BACKGROUND: Despite the increasing representation of family medicine among required clinical experiences in medical school, relatively little has been written about how students are evaluated on these experiences. This survey reports on evaluation methods used on US family medicine clerkships/ preceptorships and educator satisfaction with these methods. METHODS: Information was obtained by a survey mailed to the directors of all required allopathic family medicine clinical rotations (n = 69). RESULTS: Ninety-one percent of sites contacted returned the survey. Forty-seven percent of family medicine required clinical rotations are 6 weeks or longer, and 71% occur in the third year of medical school. The clinical grade contributes an average of 60% to the final grade, while other assignments contribute 21% to the grade. Fifty-two percent of respondents indicated "moderate or less" overall satisfaction with their current evaluation methodologies. CONCLUSIONS: Among institutions with required family medicine clerkships/preceptorships, this survey documents a trend toward these experiences occurring in the third year of medical school and lasting 6 weeks or more. In addition to traditional evaluation methodologies, other assignments contribute substantially to the overall grade on required family medicine rotations. The overall lack of satisfaction with current evaluation methodologies highlights the need for information sharing and networking among those who develop and implement evaluation methods on family medicine clerkships and preceptorships.

Asunto(s)

Prácticas Clínicas/organización & administración , Evaluación Educacional/métodos , Evaluación Educacional/normas , Medicina Familiar y Comunitaria/educación , Preceptoría/organización & administración , Actitud , Competencia Clínica/estadística & datos numéricos , Recolección de Datos , Docentes Médicos/estadística & datos numéricos , Humanos , Estados Unidos

Asunto(s)

Antiinflamatorios/uso terapéutico , Asma/tratamiento farmacológico , Glucocorticoides/uso terapéutico , Sistema Respiratorio/efectos de los fármacos , Asma/fisiopatología , Hiperreactividad Bronquial/tratamiento farmacológico , Hiperreactividad Bronquial/fisiopatología , Citocinas/metabolismo , Epitelio/efectos de los fármacos , Epitelio/fisiopatología , Humanos , Mediadores de Inflamación/metabolismo , Receptores de Superficie Celular/metabolismo , Receptores de Glucocorticoides/metabolismo , Sistema Respiratorio/fisiopatología , Esteroides

RESUMEN

We believe that there are the following four classes of glucocorticoid-sensitive cytokines that are involved in cell recruitment: (1) those that activate endothelium nonspecifically; (2) those that activate endothelium specifically; (3) those that activate, prime, and prolong the survival of eosinophils; and (4) those that stimulate movement of cells up into the epithelium. Glucocorticoids inhibit the generation of these cytokines and thereby prevent several different aspects of inflammation, including the activation and recruitment of inflammatory cells (eosinophils, basophils, and lymphocytes) and the release of inflammatory mediators. We believe such pleiotropic actions account for the efficacy and widespread use of glucocorticoids in the treatment of asthma.

Asunto(s)

Antialérgicos/farmacología , Citocinas/antagonistas & inhibidores , Glucocorticoides/farmacología , Hipersensibilidad/inmunología , Humanos , Hipersensibilidad/tratamiento farmacológico