Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 17 de 17
Filtrar
1.
Int J Med Inform ; 92: 1-7, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27318066

RESUMO

BACKGROUND: Multiple users access computer workstations in busy clinical settings, requiring many logins throughout the day as users switch from one computer to another. This can lead to workflow inefficiencies as well as security concerns resulting from users sharing login sessions to save time. Proximity cards and readers have the potential to improve efficiency and security by allowing users to access clinical workstations simply by bringing the card near the reader, without the need for manual entry of a username and password. OBJECTIVES: To assess the perceived impact of proximity cards and readers for rapid user authentication to clinical workstations in the setting of an existing electronic health record with single sign-on software already installed. METHODS: Questionnaires were administered to clinical faculty and staff five months before and three months after the installation of proximity card readers in an inpatient birthing center and an outpatient obstetrics clinic. Open-ended feedback was also collected and qualitatively analyzed. RESULTS: There were 71 and 33 responses to the pre- and post-implementation surveys, respectively. There was a significant increase in the perceived speed of login with the proximity cards, and a significant decrease in the self-reported occurrence of shared login sessions between users. Feedback regarding the system was mostly positive, although several caveats were noted, including minimal benefit when used with an obstetric application that did not support single sign-on. CONCLUSIONS: Proximity cards and readers, along with single sign-on software, have the potential to enhance workflow efficiency by allowing for faster login times and diminish security concerns by reducing shared logins on clinical workstations. The positive feedback was used by our health system leadership to support the expanded implementation of the proximity card readers throughout the clinical setting.


Assuntos
Segurança Computacional/instrumentação , Registros Eletrônicos de Saúde/instrumentação , Sistemas de Informação Hospitalar , Atitude do Pessoal de Saúde , Terminais de Computador , Confidencialidade , Humanos , Inquéritos e Questionários , Interface Usuário-Computador
2.
Phytochemistry ; 112: 139-50, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25108744

RESUMO

We have investigated the cause of the restricted multiplication of hrp mutant bacteria in leaves of Arabidopsis. Our focus was on early interactions leading to differentiation between virulent wild-type and non-pathogenic hrpA mutant strains of Pseudomonas syringae pv. tomato. An initial drop in recoverable bacteria detected 0-4 h after inoculation with either strain was dependent on a functional FLS2 receptor and H2O2 accumulation in challenged leaves. Wild-type bacteria subsequently multiplied rapidly whereas the hrpA mutant was restricted within 6 h. Despite the early restriction, the hrpA mutant was still viable several days after inoculation. Analysis of intercellular washing fluids (IWFs), showed that high levels of nutrients were readily available to bacteria in the apoplast and that no diffusible inhibitors were produced in response to bacterial challenge. Histochemical and immunocytochemical methods were used to detect changes in polysaccharides (callose, two forms of cellulose, and pectin), arabinogalactan proteins (AGPs), H2O2 and peroxidase. Quantitative analysis showed very similar changes in localisation of AGPs, cellulose epitopes and callose 2 and 4 h after inoculation with either strain. However from 6 to 12 h after inoculation papillae expanded only next to the hrp mutant. In contrast to the similar patterns of secretory activity recorded from mesophyll cells, accumulation of H2O2 and peroxidase was significantly greater around the hrpA mutant within the first 4h after inoculation. A striking differential accumulation of H2O2 was also found in chloroplasts in cells next to the mutant. Ascorbate levels were lower in the IWFs recovered from sites inoculated with the hrp mutant than with wild-type bacteria. The critical response, observed at the right time and place to explain the observed differential behaviour of wild-type and hrpA mutant bacteria was the accumulation of H2O2, probably generated through Type III peroxidase activity and in chloroplasts. It is proposed that H2O2 and apoplastic peroxidase cross-link secreted glycoproteins and polysaccharides to agglutinate the hrp mutant. Generation of H2O2 has been identified as a likely target for effector proteins injected into plant cells by the wild-type bacteria.


Assuntos
Arabidopsis/citologia , Arabidopsis/microbiologia , Proteínas de Bactérias/genética , Parede Celular/metabolismo , Mutação , Pseudomonas syringae/genética , Pseudomonas syringae/fisiologia , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Arabidopsis/metabolismo , Arabidopsis/fisiologia , Ácido Ascórbico/metabolismo , Glicoproteínas/metabolismo , Interações Hospedeiro-Patógeno , Peróxido de Hidrogênio/metabolismo , Peroxidase/metabolismo , Fenótipo , Polissacarídeos/metabolismo , Pseudomonas syringae/efeitos dos fármacos
4.
Nat Med ; 18(3): 382-4, 2012 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-22327622

RESUMO

Applying a next-generation sequencing assay targeting 145 cancer-relevant genes in 40 colorectal cancer and 24 non-small cell lung cancer formalin-fixed paraffin-embedded tissue specimens identified at least one clinically relevant genomic alteration in 59% of the samples and revealed two gene fusions, C2orf44-ALK in a colorectal cancer sample and KIF5B-RET in a lung adenocarcinoma. Further screening of 561 lung adenocarcinomas identified 11 additional tumors with KIF5B-RET gene fusions (2.0%; 95% CI 0.8-3.1%). Cells expressing oncogenic KIF5B-RET are sensitive to multi-kinase inhibitors that inhibit RET.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Neoplasias Colorretais/genética , Cinesinas/genética , Neoplasias Pulmonares/genética , Proteínas de Fusão Oncogênica/genética , Proteínas Proto-Oncogênicas c-ret/genética , Receptores Proteína Tirosina Quinases/genética , Quinase do Linfoma Anaplásico , Animais , Biópsia , Transformação Celular Neoplásica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Cinesinas/antagonistas & inibidores , Neoplasias Pulmonares/patologia , Camundongos , Células NIH 3T3 , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-ret/antagonistas & inibidores
5.
Clin Pediatr (Phila) ; 50(6): 543-9, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21565885

RESUMO

The purpose of this study was to examine pediatricians' familiarity with expert committee recommendations on the management of childhood obesity and their use of health information technology for obesity-related care. The authors interviewed 35 pediatricians from 17 primary care practices using an electronic health record; immersion crystallization facilitated analysis of the qualitative data. Nearly all pediatricians were unfamiliar with expert recommendations; however, all participants reported using growth charts and providing nutrition and physical activity counseling. Most participants wanted easy access to educational materials they could print for patients. The majority of participants were in favor of an electronic alert to identify obese patients, remind clinicians of current guidelines, and facilitate ordering, believing it would help standardize care. Concerns included "alert fatigue," distraction, and disruption of workflow. Suggestions for future electronic functions included tailored educational materials and physical activity resources customized by patient address.


Assuntos
Informática Médica , Obesidade/terapia , Pediatria/métodos , Guias de Prática Clínica como Assunto , Atenção Primária à Saúde/métodos , Adulto , Índice de Massa Corporal , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Obesidade/diagnóstico , Médicos de Atenção Primária , Resultado do Tratamento
6.
Plant Physiol ; 147(2): 503-17, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18434605

RESUMO

Receptor-like proteins (RLPs) are cell surface receptors that typically consist of an extracellular leucine-rich repeat domain, a transmembrane domain, and a short cytoplasmatic tail. In several plant species, RLPs have been found to play a role in disease resistance, such as the tomato (Solanum lycopersicum) Cf and Ve proteins and the apple (Malus domestica) HcrVf2 protein that mediate resistance against the fungal pathogens Cladosporium fulvum, Verticillium spp., and Venturia inaequalis, respectively. In addition, RLPs play a role in plant development; Arabidopsis (Arabidopsis thaliana) TOO MANY MOUTHS (TMM) regulates stomatal distribution, while Arabidopsis CLAVATA2 (CLV2) and its functional maize (Zea mays) ortholog FASCINATED EAR2 regulate meristem maintenance. In total, 57 RLP genes have been identified in the Arabidopsis genome and a genome-wide collection of T-DNA insertion lines was assembled. This collection was functionally analyzed with respect to plant growth and development and sensitivity to various stress responses, including susceptibility toward pathogens. A number of novel developmental phenotypes were revealed for our CLV2 and TMM insertion mutants. In addition, one AtRLP gene was found to mediate abscisic acid sensitivity and another AtRLP gene was found to influence nonhost resistance toward Pseudomonas syringae pv phaseolicola. This genome-wide collection of Arabidopsis RLP gene T-DNA insertion mutants provides a tool for future investigations into the biological roles of RLPs.


Assuntos
Proteínas de Arabidopsis/fisiologia , Arabidopsis/genética , Genoma de Planta , Proteínas de Arabidopsis/genética , Mutagênese Insercional
7.
Biochem Biophys Res Commun ; 362(2): 347-53, 2007 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-17719011

RESUMO

Stem cells are being evaluated in numerous human clinical trials and are commercially used in veterinary medicine to treat horses and dogs. Stem cell differentiation, homing to disease sites, growth and cytokine factor modulation, and low antigenicity contribute to their therapeutic success. Bone marrow and adipose tissue are the two most common sources of adult-derived stem cells in animals. We report on the existence of an alternative source of primitive, multipotent stem cells from the equine umbilical cord cellular matrix (Wharton's jelly). Equine umbilical cord matrix (EUCM) cells can be cultured, cryogenically preserved, and differentiated into osteo-, adipo-, chondrogenic, and neuronal cell lineages. These results identify a source of stem cells that can be non-invasively collected at birth and stored for future use in that horse or used as donor cells for treating unrelated horses.


Assuntos
Diferenciação Celular , Células-Tronco Multipotentes/citologia , Cordão Umbilical/citologia , Adipócitos/química , Adipócitos/citologia , Adipócitos/metabolismo , Adipogenia , Fosfatase Alcalina/metabolismo , Animais , Antraquinonas/química , Compostos Azo/química , Ciclo Celular , Proliferação de Células , Células Cultivadas , Condrócitos/química , Condrócitos/citologia , Condrócitos/metabolismo , Condrogênese , Feminino , Citometria de Fluxo , Cavalos , Imuno-Histoquímica , Células-Tronco Multipotentes/química , Células-Tronco Multipotentes/metabolismo , Neurônios/química , Neurônios/citologia , Neurônios/metabolismo , Osteócitos/química , Osteócitos/citologia , Osteócitos/metabolismo , Osteogênese , Cordão Umbilical/metabolismo
8.
Tissue Eng ; 13(8): 2003-10, 2007 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17518722

RESUMO

The temporomandibular joint (TMJ) presents many problems in modern musculoskeletal medicine. Patients who suffer from TMJ disorders often experience a major loss in quality of life due to the debilitating effects that TMJ disorders can have on everyday activities. Cartilage tissue engineering can lead to replacement tissues that could be used to treat TMJ disorders. In this study, a spinner flask was used for a period of 6 days to seed polyglycolic acid (PGA) scaffolds with either TMJ condylar chondrocytes or mesenchymal-like stem cells derived from human umbilical cord matrix (HUCM). Samples were then statically cultured for 4 weeks either in growth medium containing chondrogenic factors or in control medium. Immunohistochemical staining of HUCM constructs after 4 weeks revealed a strong presence of collagen I and minute amounts of collagen II, whereas TMJ constructs revealed little collagen I and no collagen II. The HUCM constructs were shown to contain more GAGs than the TMJ constructs quantitatively at week 0 and histologically at week 4. Moreover, the cellularity of HUCM constructs was 55% higher at week 0 and nearly twice as high after 4 weeks, despite being seeded at the same density. The increased level of biosynthesis and higher cellularity of HUCM constructs clearly demonstrates that the HUCM stem cells outperformed the TMJ condylar cartilage cells under the prescribed conditions. HUCM stem cells may therefore be an attractive alternative to condylar cartilage cells for TMJ tissue engineering applications. Further, given the availability and ease of obtaining HUCM stem cells, these findings may have far-reaching implications, leading to novel developments in both craniofacial and orthopaedic tissue replacement therapies.


Assuntos
Cartilagem Articular/citologia , Condrócitos/citologia , Côndilo Mandibular/citologia , Células-Tronco Multipotentes/citologia , Articulação Temporomandibular/citologia , Engenharia Tecidual , Cordão Umbilical/citologia , Diferenciação Celular/fisiologia , Células Cultivadas , Humanos
9.
Stem Cells ; 25(1): 98-106, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16960128

RESUMO

Potential therapeutic effects of Oct-4-positive rat umbilical cord matrix (RUCM) cells in treating cerebral global ischemia were evaluated using a reproducible model of cardiac arrest (CA) and resuscitation in rats. Animals were randomly assigned to four groups: A, sham-operated; B, 8-minute CA without pretreatment; C, 8-minute CA pretreated with defined media; and D, 8-minute CA pretreated with Oct-4(+) RUCM cells. Pretreatment was done 3 days before CA by 2.5-microl microinjection of defined media or approximately 10(4) Oct-4(+) RUCM cells in left thalamic nucleus, hippocampus, corpus callosum, and cortex. Damage was assessed histologically 7 days after CA and was quantified by the percentage of injured neurons in hippocampal CA1 regions. Little damage (approximately 3%-4%) was found in the sham group, whereas 50%-68% CA1 pyramidal neurons were injured in groups B and C. Pretreatment with Oct-4(+) RUCM cells significantly (p < .001) reduced neuronal loss to 25%-32%. Although the transplanted cells were found to have survived in the brain with significant migration, few were found directly in CA1. Therefore, transdifferentiation and fusion with host cells cannot be the predominant mechanisms for the observed protection. The Oct-4(+) RUCM cells might repair nonfocal tissue damage by an extracellular signaling mechanism. Treating cerebral global ischemia with umbilical cord matrix cells seems promising and worthy of further investigation.


Assuntos
Isquemia Encefálica/terapia , Células-Tronco Embrionárias/metabolismo , Células-Tronco Embrionárias/transplante , Fator 3 de Transcrição de Octâmero/uso terapêutico , Animais , Isquemia Encefálica/patologia , Primers do DNA , Modelos Animais de Doenças , Feminino , Citometria de Fluxo , Parada Cardíaca , Fator 3 de Transcrição de Octâmero/fisiologia , Gravidez , Ratos , Ratos Sprague-Dawley , Ressuscitação , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Cordão Umbilical
10.
Med Sci Sports Exerc ; 38(5): 833-9, 2006 May.
Artigo em Inglês | MEDLINE | ID: mdl-16672834

RESUMO

PURPOSE: Organ transplant patients treated with cyclosporine-A (CsA) often exhibit weight loss and muscle weakness. The cellular target of CsA, calcineurin, has been implicated in maintenance of muscle fiber size and in expression of the type I skeletal muscle phenotype. We hypothesized that CsA treatment would cause fiber atrophy, as well as increase type IIa myosin heavy chain (MHC) content and oxidative enzyme activities in the soleus muscle. METHODS: Rats were treated with CsA for 21 d (20 mg.kg(-1).d(-1); N = 16) and compared with control rats given olive oil vehicle (Veh; N = 16). Soleus muscles were excised bilaterally. MHC content was determined by gel electrophoresis, oxidative enzyme activities by spectrophotometric methods, and fiber type and size by histochemistry. RESULTS: Lymphocyte count was depressed in CsA rats (P < 0.05), indicating treatment efficacy. Type IIa MHC content was increased in the soleus muscle with CsA (Veh, 10.4 +/- 1.7%; CsA, 15.1 +/- 2.0; P < 0.05) at the expense of type I MHC. Soleus muscle oxidative enzyme activities were also increased with CsA treatment (P < 0.05). Soleus muscle atrophy occurred, reflected by a 22% decrease in fiber cross-sectional area (Veh, 3255 +/- 105 microm(2); CsA, 2533 +/- 125; P < 0.05). CONCLUSION: These findings indicate that CsA treatment is associated with changes in skeletal muscle fiber size and phenotype. The former may underlie clinical symptoms of transplant patients treated with CsA.


Assuntos
Ciclosporina/farmacologia , Imunossupressores/farmacologia , Desenvolvimento Muscular , Fibras Musculares Esqueléticas/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Animais , Ciclosporina/uso terapêutico , Eletroforese em Gel de Poliacrilamida , Imunossupressores/uso terapêutico , Masculino , Fibras Musculares Esqueléticas/fisiologia , Músculo Esquelético/enzimologia , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Atrofia Muscular/prevenção & controle , Cadeias Pesadas de Miosina/metabolismo , Ratos , Ratos Sprague-Dawley , Estados Unidos
11.
J Appl Physiol (1985) ; 94(6): 2225-36, 2003 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12562669

RESUMO

The mechanisms responsible for the decrements in exercise performance in chronic heart failure (CHF) remain poorly understood, but it has been suggested that sarcolemmal alterations could contribute to the early onset of muscular fatigue. Previously, our laboratory demonstrated that the maximal number of ouabain binding sites (B(max)) is reduced in the skeletal muscle of rats with CHF (Musch TI, Wolfram S, Hageman KS, and Pickar JG. J Appl Physiol 92: 2326-2334, 2002). These reductions may coincide with changes in the Na(+)-K(+)-ATPase isoform (alpha and beta) expression. In the present study, we tested the hypothesis that reductions in B(max) would coincide with alterations in the alpha- and beta-subunit expression of the sarcolemmal Na(+)-K(+)-ATPase of rats with CHF. Moreover, we tested the hypothesis that exercise training would increase B(max) along with producing significant changes in alpha- and beta-subunit expression. Rats underwent a sham operation (sham; n = 10) or a surgically induced myocardial infarction followed by random assignment to either a control (MI; n = 16) or exercise training group (MI-T; n = 16). The MI-T rats performed exercise training (ET) for 6-8 wk. Hemodynamic indexes demonstrated that MI and MI-T rats suffered from severe left ventricular dysfunction and congestive CHF. Maximal oxygen uptake (Vo(2 max)) and endurance capacity (run time to fatigue) were reduced in MI rats compared with sham. B(max) in the soleus and plantaris muscles and the expression of the alpha(2)-isoform of the Na(+)-K(+)-ATPase in the red portion of the gastrocnemius (gastrocnemius(red)) muscle were reduced in MI rats. After ET, Vo(2 max) and run time to fatigue were increased in the MI-T group of rats. This coincided with increases in soleus and plantaris B(max) and the expression of the alpha(2)-isoform in the gastrocnemius(red) muscle. In addition, the expression of the beta(2)-isoform of the gastrocnemius(red) muscle was increased in the MI-T rats compared with their sedentary counterparts. This study demonstrates that CHF-induced alterations in skeletal muscle Na(+)-K(+)-ATPase, including B(max) and isoform expression, can be partially reversed by ET.


Assuntos
Insuficiência Cardíaca/enzimologia , Músculo Esquelético/enzimologia , Condicionamento Físico Animal/fisiologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Animais , Sítios de Ligação , Doença Crônica , Feminino , Isoenzimas/metabolismo , Ouabaína/metabolismo , Consumo de Oxigênio , Resistência Física , Ratos , Ratos Wistar
12.
Stem Cells ; 21(1): 50-60, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12529551

RESUMO

We have identified an easily attainable source of primitive, potentially multipotent stem cells from Wharton's jelly, the matrix of umbilical cord. Wharton's jelly cells have been propagated in culture for more than 80 population doublings. Several markers for stem cells, including c-kit (CD117), and telomerase activity are expressed in these cells. Treatment with basic fibroblast growth factor overnight and low-serum media plus butylated hydroxyanisole and dimethylsulfoxide induced Wharton's jelly cells to express a neural phenotype. Within several hours of this treatment, Wharton's jelly cells developed rounded cell bodies with multiple neurite-like extensions, similar to the morphology of neural stem cells. Neuron-specific enolase (NSE), a neural stem cell marker, was expressed in these cells, as shown by immunocytochemistry. Immunoblot analysis showed similar levels of NSE expression in both untreated and induced Wharton's jelly cells. After 3 days, the induced Wharton's jelly cells resembled bipolar or multipolar neurons, with processes that formed networks reminiscent of primary cultures of neurons. The neuron-like cells in these cultures stained positively for several neuronal proteins, including neuron-specific class III beta-tubulin, neurofilament M, an axonal growth-cone-associated protein, and tyrosine hydroxylase. Immunoblot analysis showed increasing levels of protein markers for mature neurons over time post induction. Markers for oligodendrocytes and astrocytes were also detected in Wharton's jelly cells. These exciting findings show that cells from the matrix of umbilical cord have properties of stem cells and may, thus, be a rich source of primitive cells. This study shows their capacity to differentiate into a neural phenotype in vitro.


Assuntos
Matriz Extracelular/fisiologia , Neuroglia/citologia , Neurônios/citologia , Cordão Umbilical/citologia , 2',3'-Nucleotídeo Cíclico Fosfodiesterases/biossíntese , 2',3'-Nucleotídeo Cíclico Fosfodiesterases/imunologia , Astrócitos/química , Astrócitos/citologia , Astrócitos/enzimologia , Astrócitos/fisiologia , Biomarcadores , Diferenciação Celular/fisiologia , Células Cultivadas , Proteína Glial Fibrilar Ácida/biossíntese , Proteína Glial Fibrilar Ácida/imunologia , Humanos , Imuno-Histoquímica , Filamentos Intermediários/imunologia , Filamentos Intermediários/metabolismo , Células-Tronco Multipotentes/química , Células-Tronco Multipotentes/citologia , Células-Tronco Multipotentes/enzimologia , Células-Tronco Multipotentes/fisiologia , Proteínas do Tecido Nervoso/biossíntese , Proteínas do Tecido Nervoso/imunologia , Neuroglia/química , Neuroglia/enzimologia , Neuroglia/fisiologia , Neurônios/química , Neurônios/enzimologia , Neurônios/fisiologia , Oligodendroglia/química , Oligodendroglia/citologia , Oligodendroglia/enzimologia , Oligodendroglia/fisiologia , Fosfopiruvato Hidratase/biossíntese , Fosfopiruvato Hidratase/imunologia
13.
Clin Diagn Lab Immunol ; 9(6): 1277-81, 2002 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-12414761

RESUMO

Bovine immunodeficiency virus (BIV) and Jembrana disease virus (JDV) are closely related bovine lentiviruses that are difficult to distinguish by presently available diagnostic methods. Recently, in our laboratory, a monoclonal antibody (MAb; MAb 10H1) against the BIV Gag protein identified a differential epitope, located at the 6.4-kDa N terminus of a 29-kDa Gag capsid protein, which was absent in JDV. To define the essential amino acids of the epitope, a series of primers within the 163 bp of DNA corresponding to the 6.4-kDa protein were designed. The full-length 163-bp DNA fragment and the smaller DNA fragments with deletions were amplified by PCR and then cloned into pQE32 vectors for protein expression studies. The expressed proteins were analyzed with MAb 10H1 by Western blotting. The differential epitope has been narrowed to a 26-amino-acid region (R121 to R146), which includes 6 residues of p16(MA) (where MA represents the matrix protein) and 20 residues of p2L. A synthetic peptide corresponding to the putative 26-amino-acid epitope blocked MAb 10H1 binding to the expressed peptide. These experiments revealed that the epitope spans the cleavage site between p16(MA) and p2L and presumably will be valuable in distinguishing the two viruses.


Assuntos
Mapeamento de Epitopos , Produtos do Gene gag/imunologia , Vírus da Imunodeficiência Bovina/química , Sequência de Aminoácidos , Animais , Bovinos , Clonagem Molecular , Produtos do Gene gag/química , Produtos do Gene gag/genética , Lentivirus Bovinos/química , Dados de Sequência Molecular
14.
Am J Physiol Cell Physiol ; 283(4): C1033-44, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12225967

RESUMO

This study focused on the role of sodium-bicarbonate cotransporter (NBC1) in cAMP-stimulated ion transport in porcine vas deferens epithelium. Ion substitution experiments in modified Ussing chambers revealed that cAMP-mediated stimulation was dependent on the presence of Na(+), HCO, and Cl(-) for a full response. HCO-dependent current was unaffected by acetazolamide, bumetanide, or amiloride but was inhibited by basolateral 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid. Na(+)-driven, HCO-dependent, stilbene-inhibitable anion flux was observed across the basolateral membrane of selectively permeabilized monolayers. Results of radiotracer flux studies suggest a 4,4'-dinitrostilbene-2,2'-disulfonate-sensitive stoichiometry of 2 base equivalents per Na(+). Antibodies raised against rat kidney NBC epitopes (rkNBC; amino acids 338-391 and 928-1035) identified a single band of ~145 kDa. RT-PCR detected NBC1 message in porcine vas deferens epithelia. These results demonstrate that vas deferens epithelial cells possess the proteins necessary for the vectoral transport of HCO and that these mechanisms are maintained in primary culture. Taken together, the results indicate that vas deferens epithelia play an active role in male fertility and have implications for our understanding of the relationship between cystic fibrosis and congenital bilateral absence of the vas deferens.


Assuntos
Células Epiteliais/metabolismo , Simportadores de Sódio-Bicarbonato/metabolismo , Ducto Deferente/metabolismo , Ácido 4,4'-Di-Isotiocianoestilbeno-2,2'-Dissulfônico/farmacologia , Animais , Sequência de Bases , Bicarbonatos/metabolismo , Inibidores da Anidrase Carbônica/farmacologia , Células Cultivadas , Cloretos/metabolismo , Colforsina/farmacologia , AMP Cíclico/metabolismo , Cultura em Câmaras de Difusão , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Epitopos/imunologia , Immunoblotting , Transporte de Íons/efeitos dos fármacos , Transporte de Íons/fisiologia , Masculino , Dados de Sequência Molecular , RNA Mensageiro/análise , RNA Mensageiro/biossíntese , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência de Aminoácidos , Sódio/metabolismo , Simportadores de Sódio-Bicarbonato/efeitos dos fármacos , Simportadores de Sódio-Bicarbonato/genética , Estilbenos/farmacologia , Suínos , Ducto Deferente/citologia
15.
Biochemistry ; 41(23): 7350-8, 2002 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-12044167

RESUMO

Restoration of chloride conductance via the introduction of an anion selective pore, formed by a channel-forming peptide, has been hypothesized as a novel treatment modality for patients with cystic fibrosis (CF). Delivery of these peptide sequences to airway cells from an aqueous environment in the absence of organic solvents is paramount. New highly soluble COOH- and NH(2)-terminal truncated peptides, derived from the second transmembrane segment of the glycine receptor alpha-subunit (M2GlyR), were generated, with decreasing numbers of amino acid residues. NH(2)-terminal lysyl-adducted truncated peptides with lengths of 22, 25, and 27 amino acid residues are equally able to stimulate short circuit current (I(SC)). Peptides with as few as 16 amino acid residues are able to stimulate I(SC), although to a lesser degree. In contrast, COOH-terminal truncated peptides show greatly reduced induced I(SC) values for all peptides fewer than 27 residues in length and show no measurable activity for peptides fewer than 21 residues in length. CD spectra for both the NH(2)- and COOH-truncated peptides have random structure in aqueous solution, and those sequences that stimulated the highest maximal I(SC) are predominantly helical in 40% trifluoroethanol. Peptides with a decreased propensity to form helical structures in TFE also failed to stimulate I(SC). Palindromic peptide sequences based on both the NH(2)- and COOH-terminal halves of M2GlyR were synthesized to test roles of the COOH- and NH(2)-terminal halves of the molecule in solution aggregation and channel forming ability. On the basis of the study presented here, there are distinct, nonoverlapping regions of the M2GlyR sequence that define solution aggregation and membrane channel assembly. Peptides that eliminate solution aggregation with complete retention of channel forming activity were generated.


Assuntos
Canais Iônicos/fisiologia , Fragmentos de Peptídeos/fisiologia , Receptores de Glicina/fisiologia , Sequência de Aminoácidos , Animais , Linhagem Celular , Membrana Celular/química , Membrana Celular/fisiologia , Dicroísmo Circular , Reagentes de Ligações Cruzadas/química , Cães , Eletrofisiologia , Humanos , Canais Iônicos/química , Lisina/química , Modelos Químicos , Dados de Sequência Molecular , Fragmentos de Peptídeos/química , Estrutura Secundária de Proteína , Transporte Proteico , Receptores de Glicina/química , Soluções
16.
Am J Physiol Heart Circ Physiol ; 283(1): H126-38, 2002 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-12063283

RESUMO

In dogs and in humans, potassium channels formed by ether-a-go-go-related gene 1 protein ERG1 (KCNH2) and KCNQ1 alpha-subunits, in association with KCNE beta-subunits, play a role in normal repolarization and may contribute to abnormal repolarization associated with long QT syndrome (LQTS). The molecular basis of repolarization in horse heart is unknown, although horses exhibit common cardiac arrhythmias and may receive drugs that induce LQTS. In horse heart, we have used immunoblotting and immunostaining to demonstrate the expression of ERG1, KCNQ1, KCNE1, and KCNE3 proteins and RT-PCR to detect KCNE2 message. Peptide N-glycosidase F-sensitive forms of horse ERG1 (145 kDa) and KCNQ1 (75 kDa) were detected. Both ERG1 and KCNQ1 coimmunoprecipitated with KCNE1. Cardiac action potential duration was prolonged by antagonists of either ERG1 (MK-499, cisapride) or KCNQ1/KCNE1 (chromanol 293B). Patch-clamp analysis confirmed the presence of a slow delayed rectifier current. These data suggest that repolarizing currents in horses are similar to those of other species, and that horses are therefore at risk for acquired LQTS. The data also provide unique evidence for coassociation between ERG1 and KCNE1 in cardiac tissue.


Assuntos
Miocárdio/metabolismo , Canais de Potássio de Abertura Dependente da Tensão da Membrana , Canais de Potássio/metabolismo , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Animais , Antiarrítmicos/farmacologia , Benzopiranos/farmacologia , Linhagem Celular , Cisaprida/farmacologia , Cricetinae , Canal de Potássio ERG1 , Canais de Potássio Éter-A-Go-Go , Cavalos , Humanos , Immunoblotting , Imuno-Histoquímica , Técnicas In Vitro , Canais de Potássio KCNQ , Canal de Potássio KCNQ1 , Síndrome do QT Longo/etiologia , Miocárdio/citologia , Técnicas de Patch-Clamp , Piperidinas/farmacologia , Potássio/metabolismo , Bloqueadores dos Canais de Potássio , Canais de Potássio/biossíntese , Canais de Potássio/genética , Ligação Proteica/fisiologia , RNA Mensageiro/metabolismo , Suínos
17.
Mol Pharmacol ; 61(1): 201-13, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11752222

RESUMO

The major objective of this study was to elucidate the molecular bases for K(+) current diversity in porcine granulosa cells (GC). Two delayed rectifier K(+) currents with distinct electrophysiological and pharmacological properties were recorded from porcine GC by using whole-cell patch clamp: 1) a slowly activating, noninactivating current (I(Ks)) antagonized by clofilium, 293B, L-735,821, and L-768,673; and 2) an ultrarapidly activating, slowly inactivating current (I(Kur)) antagonized completely by clofilium and 4-aminopyridine and partially by tetraethylammonium, charybdotoxin, dendrotoxin, and kaliotoxin. The molecular identity of the K(+) channel genes underlying I(Ks) and I(Kur) was examined using reverse transcription-polymerase chain reaction and immunoblotting to detect K(+) channel transcripts and proteins. We found that GC could express multiple voltage-dependent K(+) (Kv) channel subunits, including KCNQ1, KCNE1, Kv1.1, Kv1.2, Kv1.3, Kv1.4, Kv1.5, Kv1.6, Kvbeta1.3, and Kvbeta2. Coimmunoprecipitation was used to establish the hetero-oligomeric nature of granulosa cell Kv channels. KCNE1 and KCNQ1 were coassociated in GC, and their expression coincided with the expression of I(Ks). Extensive coassociation of the various Kv alpha- and beta-subunits was also documented, suggesting that the diverse electrophysiological and pharmacological properties of I(Kur) currents may reflect variation in the composition and stoichiometry of the channel assemblies, as well as differences in post-translational modification of contributing Kv channel subunits. Our findings provide an essential background for experimental definition of granulosa K(+) channel function(s). It will be critical to define the functional roles of specific GC K(+) channels, because these proteins may represent either novel targets for assisted reproduction or potential sites of drug toxicity.


Assuntos
Células da Granulosa/fisiologia , Canais de Potássio de Abertura Dependente da Tensão da Membrana , Canais de Potássio/fisiologia , Sequência de Aminoácidos , Animais , Células Cultivadas , Canais de Potássio de Retificação Tardia , Eletrofisiologia , Feminino , Variação Genética , Células da Granulosa/metabolismo , Dados de Sequência Molecular , Canais de Potássio/genética , Canais de Potássio/metabolismo , Homologia de Sequência de Aminoácidos , Suínos , Transcrição Gênica
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...