Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
1.
JAMA Oncol ; 3(2): 220-226, 2017 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-27930762

RESUMO

IMPORTANCE: The Canadian Cancer Trials Group study HN.6 is the largest randomized clinical trial to date comparing the concurrent administration of anti-epidermal growth factor receptor (EGFR) monoclonal antibodies with radiotherapy (RT) to standard chemoradiotherapy in locoregionally advanced squamous cell carcinoma of the head and neck (LA-SCCHN). OBJECTIVE: To compare progression-free survival (PFS) in patients with LA-SCCHN treated with standard-fractionation RT plus high-dose cisplatin vs accelerated-fractionation RT plus the anti-EGFR antibody panitumumab. DESIGN, SETTING, AND PARTICIPANTS: A randomized phase 3 clinical trial in 17 Canadian centers. A total of 320 patients were randomized between December 2008 and November 2011. INTERVENTIONS: Patients with TanyN+M0 or T3-4N0M0 LA-SCCHN were randomized 1:1 to receive standard-fractionation RT (70 Gy/35 over 7 weeks) plus cisplatin at 100 mg/m2 intravenous for 3 doses (arm A) vs accelerated-fractionation RT (70 Gy/35 over 6 weeks) plus panitumumab at 9 mg/kg intravenous for 3 doses (arm B). MAIN OUTCOMES AND MEASURES: Primary end point was PFS. Due to an observed declining event rate, the protocol was amended to a time-based analysis. Secondary end points included overall survival, local and regional PFS, distant metastasis-free survival, quality of life, adverse events, and safety. RESULTS: Of 320 patients randomized (268 [84%] male; median age, 56 years), 156 received arm A and 159 arm B. A total of 93 PFS events occurred. By intention-to-treat, 2-year PFS was 73% (95% CI, 65%-79%) in arm A and 76% (95% CI, 68%-82%) in arm B (hazard ratio [HR], 0.95; 95% CI, 0.60-1.50; P = .83). The upper bound of the HR 95% CI exceeded the prespecified noninferiority margin. Two-year overall survival was 85% (95% CI, 78%-90%) in arm A and 88% (95% CI, 82%-92%) in arm B (HR, 0.89; 95% CI, 0.54-1.48; P = .66). Incidence of any grade 3 to 5 nonhematologic adverse event was 88% in arm A and 92% in arm B (P = .25). CONCLUSIONS AND RELEVANCE: With a median follow-up of 46 months, the PFS of panitumumab plus accelerated-fractionation RT was not superior to cisplatin plus standard-fractionation RT in LA-SCCHN and noninferiority was not proven. Despite having negative results, HN.6 has contributed important data regarding disease control and toxic effects of these treatment strategies. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00820248.

2.
Euro Surveill ; 20(15)2015 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-25953129

RESUMO

Surveillance data suggest an intensification of the shigellosis epidemic associated with sexual transmissionin men who have sex with men (MSM) in England with separate introductions into the population. In 2014, sexual transmission between MSM might have accounted for 97%, 89%, and 43% of non-travel associated Shigella flexneri 3a and S. flexneri 2a, andS. sonnei diagnoses. Clinicians should sensitively ascertain sexual history for men with enteric infections to facilitate prompt diagnosis and appropriate management.


Assuntos
Disenteria Bacilar/epidemiologia , Epidemias , Homossexualidade Masculina , Infecções Sexualmente Transmissíveis/epidemiologia , Shigella flexneri/isolamento & purificação , Shigella sonnei/isolamento & purificação , Adolescente , Adulto , Idoso , Disenteria Bacilar/diagnóstico , Disenteria Bacilar/transmissão , Inglaterra/epidemiologia , Humanos , Masculino , Pessoa de Meia-Idade , Vigilância da População , Fatores de Risco , Comportamento Sexual , Parceiros Sexuais , Infecções Sexualmente Transmissíveis/microbiologia , Adulto Jovem
3.
Cell Prolif ; 46(1): 45-57, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23279018

RESUMO

OBJECTIVES: The systemic environment and satellite cell dysfunction have been proposed as important contributors in the development of sarcopenia and impaired skeletal muscle regrowth with ageing. In the present study, we investigated effects of serum age on proliferation of muscle precursor cells (MPCs) isolated from skeletal muscles of young and old rats. MATERIALS AND METHODS: We examined proliferation and subsequent differentiation of non-passaged MPCs isolated from skeletal muscles of 1-, 3- and 32-month old rats over a 72-h time course, using a serum cross-over design. RESULTS AND CONCLUSIONS: We found no effect of serum age on MPC proliferation, but we did discover that MPCs isolated from skeletal muscle of 32-month old rats had delayed onset of, and exit from proliferation, compared to MPCs isolated from skeletal muscle of 1-month old rats. Delayed proliferation of MPCs from 32-month old rats was associated with delayed p38 MAPK phosphorylation, and MyoD and p21(Cip1) protein expression. We also demonstrate that MPCs from 32-month old rats exhibited lower levels of muscle creatine kinase mRNA compared to 1-month old rats, but elevated levels of myogenin mRNA, when stimulated to differentiate after 36 h proliferation. These findings suggest that delayed entry and exit of the cell cycle observed in MPCs from 32-month old rats may compromise their ability to respond to differentiation stimuli and subsequently impair myogenic potential of 32-month old skeletal muscle, in this model.


Assuntos
Diferenciação Celular , Músculo Esquelético/citologia , Mioblastos/citologia , Animais , Proliferação de Células , Células Cultivadas , Creatina Quinase/genética , Creatina Quinase/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Masculino , Proteína MyoD/metabolismo , Mioblastos/enzimologia , Mioblastos/metabolismo , Fosforilação , RNA Mensageiro/metabolismo , Ratos , Ratos Endogâmicos F344 , Fatores de Tempo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
4.
Cell Prolif ; 41(2): 193-207, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18336467

RESUMO

OBJECTIVE: While it is common practice to culture cells in the presence of ambient oxygen (approximately 21% O2), O2 level observed in the physiological environment is often much lower. Previous efforts to culture a variety of different stem cells, including muscle precursor cells (MPC), under O2 conditions that better mimic in vivo conditions have resulted in enhanced proliferation. In the present study, we hypothesized that 20% O2 in culture represents a sufficient stimulus to cause increased expression of two key negative regulators of the cell-cycle Cip/Kip family of cyclin-dependent kinase inhibitors, p21(Cip1) and p27(Kip1), in MPCs. MATERIALS AND METHODS: MPCs were isolated from Fischer 344 x Brown Norway F(1) hybrid male rats and O2 was adjusted in culture using a tri-gas incubator. RESULTS: 5-Bromo-2'-deoxyuridine incorporation, cell number and nuclear proliferating cell nuclear antigen expression were all decreased after 48 h culture in 20% O2, compared to 5% O2. Twenty per cent O2 had no effect on either p27(Kip1) promoter activity or protein expression. Although p21(Cip1) promoter activity remained unchanged between 5% and 20% O2, there were significant increases in both p21(Cip1) mRNA and protein expression. Furthermore, 20% O2 caused an increase in p21(Cip1) mRNA stability and p53 transcription factor activity. CONCLUSION: These findings are considered important because they reveal p21(Cip1) as a critical regulatory protein that needs to be considered when interpreting proliferation data from MPCs studied in culture. In addition, O2-dependent regulation of MPC proliferation is relevant to conditions, including sarcopenia, heart failure, cancer and muscular dystrophy, where increased oxidative stress exists.


Assuntos
Inibidor de Quinase Dependente de Ciclina p21/genética , Expressão Gênica/efeitos dos fármacos , Mioblastos Esqueléticos/citologia , Oxigênio/farmacologia , Animais , Bromodesoxiuridina/farmacologia , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Cruzamentos Genéticos , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Relação Dose-Resposta a Droga , Masculino , Mioblastos Esqueléticos/efeitos dos fármacos , Mioblastos Esqueléticos/fisiologia , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/genética , Ratos , Ratos Endogâmicos BN , Ratos Endogâmicos F344 , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo , Proteína Supressora de Tumor p53/efeitos dos fármacos , Proteína Supressora de Tumor p53/metabolismo , Regulação para Cima/efeitos dos fármacos
5.
Nurse Educ Pract ; 1(1): 19-26, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19036239

RESUMO

This paper intends to encourage debate on how evidence-based practice may be achieved through developing an integrated approach to teaching clinical practice skills by using case study as a teaching method. This is achieved by examining societal, social, and political changes as well as the changes that have occurred in nurse education over the past 15 years. What evidence-based nursing is, the processes required to practice it effectively and how case study as a teaching method can support these processes are described. Finally, the paper describes how, as educationalists involved in curriculum development, the introduction of an integrated approach to teaching clinical skills may be a way forward in resolving the concerns highlighted by the recent Department of Health (DoH) publications.

7.
J Cell Physiol ; 174(1): 78-89, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9397158

RESUMO

We previously reported that serine elastase activity is induced in cultured porcine pulmonary artery (PA) smooth muscle cells (SMC) following serum stimulation by a mechanism involving adhesion of elastin to an elastin binding protein and tyrosine kinase activity. The present study demonstrates that a PA endothelial cell factor also promotes a fourfold increase in elastin adhesion to PA SMC and a twofold increase in serine elastase activity. The mechanism involves tethering of the factor to SMC, since [3H]-elastin pre-incubated with serum or endothelial cell (EC)-conditioned medium or SMC pre-treated with serum accelerates binding of elastin and tyrosine-kinase related elastase activity. The serum factor appears to interact with integrins as elastase induction is partially inhibited by RGD peptides. The elastase-inducing properties of serum could not, however, be attributed to several RGD-containing proteins. While a 120 kD fibronectin fragment partially reproduced the effect, it was not found in the serum fraction containing elastase-inducing activity. Instead, a 27 kD serum protein was enriched by elastin affinity chromatography, identified as apolipoprotein (Apo) A1 by microsequence analysis, and found to have about 50% of the elastase-inducing activity of serum. Elastase induction is inhibited by actinomycin and cycloheximide, suggesting a requirement for mRNA transcription and protein synthesis. Our results suggest a novel cell-extracellular matrix interaction whereby a soluble factor, in this case a lipoprotein, binds and tethers a matrix component to the cell surface and induces tyrosine kinase-dependent transcription of mRNA culminating in substrate proteolysis.


Assuntos
Apolipoproteína A-I/metabolismo , Elastina/metabolismo , Músculo Liso Vascular/metabolismo , Elastase Pancreática/metabolismo , Animais , Sítios de Ligação , Proteínas Sanguíneas/metabolismo , Células Cultivadas , Endotélio Vascular/metabolismo , Ativação Enzimática , Ligação Proteica , Transdução de Sinais , Suínos
8.
Arterioscler Thromb Vasc Biol ; 15(12): 2200-6, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-7489243

RESUMO

We investigated the association between tissue elastolytic activity and the development of neointimal formation using a previously described porcine aortic organ culture. Neointimal formation is associated with the presence of intact endothelium (nondenuded cultures) but is markedly reduced if endothelial cells are removed (denuded cultures). In nondenuded organ cultures, elastolytic activity assessed by using [3H]elastin increased sixfold at day 3 after initiation of the culture (P < .01), a time earlier than the previously published increase in intimal smooth muscle cells (ISMCs). Elastolytic activity did not increase from day 3 to day 7 despite doubling of ISMCs but did double by day 14 (P < .01) and remained elevated to day 28, correlating with increases in ISMCs. In denuded organ cultures, elastolytic activity was much lower than in nondenuded organ cultures at day 3 (P < .05) but increased fivefold in the presence of nondenuded organ culture conditioned medium (P < .01). Addition of alpha 1-proteinase inhibitor for 14 days caused a 60% decrease in elastolytic activity in nondenuded organ cultures and a 27% reduction in ISMCs compared with untreated controls (P < .05 for both). The elastolytic activity, resolved as lytic bands on an elastin substrate gel, reflected candidate enzymes, one at 76 kD and perhaps a doublet at 43 and 50 kD. Our study suggests that endothelial cells release a soluble agent that enhances elastin-degrading activity in the aorta and may at least partially account for the initiation of neointimal formation.


Assuntos
Aorta/metabolismo , Aorta/fisiologia , Elastina/metabolismo , Túnica Íntima/fisiologia , alfa 1-Antitripsina/farmacologia , Animais , Eletroforese em Gel de Poliacrilamida , Endotélio Vascular/fisiologia , Músculo Liso Vascular/metabolismo , Técnicas de Cultura de Órgãos , Suínos
9.
J Cell Physiol ; 160(1): 121-31, 1994 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8021292

RESUMO

In previous studies, we related increased elastolytic activity in pulmonary arteries (PA) with endothelial injury to the later development of PA hypertension in rats. As the mechanism causing the increased PA elastase was unknown, we hypothesized that serum factors which are accessible to vascular smooth muscle cells (SMC) following endothelial injury stimulate their elastolytic activity. To test this, we developed an in vitro assay in which we added [3H]-elastin to cultured vascular SMC after 24 h serum starvation and monitored elastolysis following a further 24 h incubation with fetal bovine serum (FBS). We observed that serum induced increased elastolytic activity in both PA and aorta-derived SMC but not in endothelial cells or SMC with low basal levels of elastolytic activity. Maximum stimulation of SMC elastolytic activity occurred with a concentration as low as 1% FBS and despite elastase inhibitors in serum, suggesting that the activity is confined to the immediate pericellular region where enzyme concentration is high. Serum-stimulated elastolytic activity was not reproduced by growth factors or cytokines known to be associated with vascular disease or to induce release of elastases in other cells. The serum inducing elastolytic activity was heat and acid labile. It was associated with increased elastin adhesion to the 67 kD elastin binding protein on SMC surfaces and was prevented by tyrosine kinase inhibitors but not protein kinase C or A inhibitors. Our studies therefore suggest a mechanism whereby serum induction of SMC elastase requires signalling through the elastin binding protein and activation of tyrosine kinase.


Assuntos
Proteínas Sanguíneas/farmacologia , Músculo Liso Vascular/citologia , Músculo Liso Vascular/enzimologia , Elastase Pancreática/metabolismo , Proteínas Tirosina Quinases/análise , Proteínas Tirosina Quinases/fisiologia , Transdução de Sinais/fisiologia , Animais , Adesão Celular/efeitos dos fármacos , Adesão Celular/fisiologia , Células Cultivadas , Elastina/farmacologia , Endotélio Vascular/citologia , Endotélio Vascular/enzimologia , Endotélio Vascular/metabolismo , Humanos , Técnicas In Vitro , Interleucina-1/farmacologia , Músculo Liso Vascular/metabolismo , Fator de Crescimento Derivado de Plaquetas/farmacologia , Ovinos , Transdução de Sinais/efeitos dos fármacos , Suínos , Fator de Necrose Tumoral alfa/farmacologia
10.
Biochem J ; 296 ( Pt 3): 745-51, 1993 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-8280072

RESUMO

A single 42 kDa isoform of mitogen-activated protein (MAP) kinase is expressed in both embryonic and adult chicken gizzard. The gizzard MAP kinase, which cross-reacts with anti-p44mpk antibody, has been purified from adult chicken gizzard and partially characterized. The purification protocol employs phenyl-Sepharose, polylysine-agarose, hydroxyapatite, Mono-Q and phenyl-Superose column chromatography. The purified enzyme phosphorylates myelin basic protein and gizzard high-molecular-mass (h-)caldesmon. Sea-star p44mpk and gizzard MAP kinase phosphorylate h-caldesmon at identical sites at the C-terminal domain, as revealed by tryptic-peptide mapping of the phosphorylated protein. Phosphorylation of h-caldesmon by gizzard MAP kinase abolishes its interaction with polymerized tubulin. The specific activity of the purified gizzard kinase toward myelin basic protein is similar to that of brain tau kinase, but is only a fraction of that of activated sea-star p44mpk. This suggests that, although a large amount of MAP kinase is present in the gizzard, only a small percentage of the enzyme is activated normally. Autophosphorylation of the gizzard kinase, at least in part on tyrosine residues, activates its kinase activity.


Assuntos
Proteínas de Ligação a Calmodulina/metabolismo , Músculo Liso/enzimologia , Proteínas Serina-Treonina Quinases/isolamento & purificação , Proteínas Tirosina Quinases/isolamento & purificação , Sequência de Aminoácidos , Animais , Galinhas , Cromatografia em Gel , Eletroforese em Gel de Poliacrilamida , Ativação Enzimática , Proteína Quinase 1 Ativada por Mitógeno , Dados de Sequência Molecular , Fosforilação , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Tirosina Quinases/metabolismo , Especificidade por Substrato
11.
Biochem Cell Biol ; 71(11-12): 544-55, 1993.
Artigo em Inglês | MEDLINE | ID: mdl-7514882

RESUMO

We have purified 42- and 44-kilodalton (kDa) isoforms of the mitogen-activated protein (MAP) kinase family from bovine brain. The kinases were assayed with myelin basic protein as the substrate and detected by anti-sea star p44mpk antibody. Purification was achieved using phenyl-Sepharose, polylysine-agarose, hydroxylapatite, and Mono-Q column chromatography. Both myelin basic protein and smooth muscle caldesmon, but not histone H1, served as good substrates. Based on chromatographic behaviors and specific activities toward myelin basic protein, it is likely that the 42-kDa brain isoform is similar to that of brain tau kinase. The 44-kDa enzyme, however, is a novel brain MAP kinase isoform not reported previously. Although it has been demonstrated that p44mpk can be activated in vitro through phosphorylation by the tyrosine kinase p56lck, neither of the brain kinases were significantly stimulated by the tyrosine kinases p56lck, p56lyn, or p59fyn. However, based on antibody cross-reactivity, a MAP kinase kinase is present in the crude brain extract. Both brain MAP kinases were capable of autophosphorylation which occurred, at least in part, on tyrosine residues. However, only the 44-kDa isoform showed a significant degree of coincident activation.


Assuntos
Encéfalo/enzimologia , Proteínas Quinases Dependentes de Cálcio-Calmodulina/isolamento & purificação , Isoenzimas/isolamento & purificação , Sequência de Aminoácidos , Animais , Proteínas Quinases Dependentes de Cálcio-Calmodulina/imunologia , Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Proteínas de Ligação a Calmodulina/metabolismo , Bovinos , Diferenciação Celular , Reações Cruzadas , Ativação Enzimática , Isoenzimas/imunologia , Isoenzimas/metabolismo , Proteína Tirosina Quinase p56(lck) Linfócito-Específica , Quinases de Proteína Quinase Ativadas por Mitógeno , Dados de Sequência Molecular , Proteína Básica da Mielina/metabolismo , Fosforilação , Fosfotirosina , Proteínas Quinases/metabolismo , Proteínas Tirosina Quinases/metabolismo , Especificidade por Substrato , Tirosina/análogos & derivados , Tirosina/análise
12.
Am J Surg ; 165(5): 554-7, 1993 May.
Artigo em Inglês | MEDLINE | ID: mdl-7683844

RESUMO

Thirty-one patients underwent limited hepatic resection with Roux-en-Y biliary-enteric anastomosis and placement of biliary stents for cholangiocarcinoma of the hepatic duct bifurcation (Klatskin tumor). Resection included wide tumor excision and bile duct resection at the liver hilum without major hepatic resection and was undertaken in all patients unless precluded by intraoperative evidence of vascular invasion. All patients were operated on by a single surgeon during the 10 years between 1981 and 1991. Similar procedures were performed for both curative (n = 17) and palliative (n = 14) treatment of this disease entity. In this series, the overall mean postoperative survival of these patients was 17 months. The mean postoperative survival of patients undergoing surgery with curative intent was 21 months in contrast to 12 months for those undergoing planned palliation. One patient in this series has been alive for more than 6 years with no evidence of disease. Five patients experienced major postoperative complications (16%), and there were two perioperative deaths (6%). This retrospective review supports an aggressive surgical approach in patients with Klatskin tumor.


Assuntos
Adenoma de Ducto Biliar/cirurgia , Neoplasias dos Ductos Biliares/cirurgia , Ducto Hepático Comum , Adenocarcinoma/mortalidade , Adenocarcinoma/cirurgia , Adenocarcinoma Papilar/mortalidade , Adenocarcinoma Papilar/cirurgia , Adenoma de Ducto Biliar/mortalidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias dos Ductos Biliares/mortalidade , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/cirurgia , Terapia Combinada , Feminino , Humanos , Metástase Linfática , Masculino , Pessoa de Meia-Idade , Cuidados Paliativos , Complicações Pós-Operatórias , Estudos Retrospectivos , Taxa de Sobrevida
13.
J Biol Chem ; 267(32): 22853-9, 1992 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-1331069

RESUMO

Smooth muscle caldesmon was phosphorylated in vitro by sea star p44mpk up to 2.0 mol of phosphate/mol of protein at both Ser and Thr residues. The phosphorylation sites were contained mainly in the COOH-terminal 10-kDa cyanogen bromide fragment which houses the binding sites for calmodulin, tropomyosin, and F-actin. Tryptic peptide maps of 32P-labeled caldesmon by p44mpk and p34cdc2 showed that while both enzymes recognized similar sites of phosphorylation, they have different preferred sites. Phosphorylation of caldesmon attenuated slightly its interaction with actin and had no effect on its binding to calmodulin and tropomyosin. Smooth muscle cell extracts from chicken gizzard and rat aorta contained 42- and 44-kDa proteins, respectively, which were cross-reactive with an antibody to sea star p44mpk. Immunoprecipitates from gizzard and aorta cell extracts, generated with the p44mpk antibody, possessed kinase activities toward myelin basic protein as well as caldesmon. These results suggest that MAP kinase may have functions in the differentiated smooth muscle cells distinct from those involved in the cell cycle.


Assuntos
Proteína Quinase CDC2/metabolismo , Proteínas de Ligação a Calmodulina/metabolismo , Músculo Liso/metabolismo , Proteínas Quinases/metabolismo , Sequência de Aminoácidos , Animais , Sítios de Ligação , Proteína Quinase CDC2/genética , Proteínas Quinases Dependentes de Cálcio-Calmodulina , Proteínas de Ligação a Calmodulina/isolamento & purificação , Galinhas , Cromatografia de Afinidade , Moela das Aves , Células HeLa , Humanos , Cinética , Dados de Sequência Molecular , Moluscos , Fragmentos de Peptídeos/isolamento & purificação , Mapeamento de Peptídeos , Fosforilação , Proteínas Quinases/genética
14.
Biochim Biophys Acta ; 1121(1-2): 41-6, 1992 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-1599949

RESUMO

The interaction between chicken gizzard calponin and tropomyosin was examined using viscosity, light scattering, electron microscopy and affinity chromatography. At neutral pH, 10 mM NaCl and in the absence of Mg2+, calponin induced tropomyosin filaments to form paracrystals thus decreasing the viscosity while increasing dramatically the light scattering of the tropomyosin solution. Electron micrographs of the uranyl acetate stained calponin-tropomyosin complex showed the presence of spindle shaped paracrystals with regular striation patterns and repeating units of about 400 A. Under similar conditions, smooth muscle caldesmon also induced tropomyosin to form paracrystals. To localize the calponin-binding site on tropomyosin, binding of fragments of tropomyosin, generated by chemical and mutational means, to a calponin-affinity column was studied. The COOH-terminal tropomyosin fragment Cn1B(142-281) and the NH2-terminal fragment CSM-beta(1/8/12-227) bound to a calponin-affinity column with an affinity similar to that of intact tropomyosin; while the NH2-terminal fragment, Cn1A(11-127), did not bind, indicating that the calponin-binding site(s) resides within residues 142-227 of tropomyosin. To determine the involvement in calponin binding of the area around Cys-190 of tropomyosin, fragments with cleavage sites near or at Cys-190 were used. Thus, while fragments Cy2(190-284) and CSM-beta(1/8/12-200) bound weakly to the calponin-affinity column, fragment Cy1(1-189) did not. These results demonstrate that calponin binds to tropomyosin between residues 142 and 227, and that the integrity of the region around Cys-190 of tropomyosin is important for strong interaction between the two proteins.


Assuntos
Proteínas de Ligação ao Cálcio/metabolismo , Proteínas Musculares/metabolismo , Tropomiosina/metabolismo , Animais , Proteínas de Ligação ao Cálcio/química , Proteínas de Ligação ao Cálcio/ultraestrutura , Galinhas , Cromatografia de Afinidade , Moela das Aves/metabolismo , Luz , Proteínas dos Microfilamentos , Microscopia Eletrônica , Músculo Liso/metabolismo , Fragmentos de Peptídeos/isolamento & purificação , Fragmentos de Peptídeos/metabolismo , Espalhamento de Radiação , Tropomiosina/química , Tropomiosina/ultraestrutura , Viscosidade , Calponinas
15.
Hypertension ; 16(6): 662-8, 1990 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2147174

RESUMO

Several experimental models involving the development of cardiac hypertrophy in adult rats are characterized by the reexpression of the fetal isoform of myosin heavy chain (V3). To determine whether a similar adult-to-fetal shift in the expression of the thin-filament proteins occurs during cardiac hypertrophy, we have examined the expression of the isoforms of myosin, tropomyosin, and troponin T in the left ventricle of young spontaneously hypertensive rats (SHR) with and without treatment using enalapril, an angiotensin converting enzyme inhibitor. Phosphorylation of tropomyosin, which is predominant in the fetal state, was also analyzed. Twelve-week-old SHR were treated with enalapril for 2, 5, 8, and 9 weeks followed by withdrawal of treatment for 9 weeks. Control SHR, without drug treatment, were weight- and age-matched. After 9 weeks of enalapril treatment, mean arterial blood pressure was reduced (from 166 +/- 11 to 89 +/- 5 mm Hg), and left ventricular weight/body weight ratio was regressed (from 2.53 +/- 0.14 to 1.96 +/- 0.05 g/kg) to normotensive levels. During the 9-week treatment period, the percent V3 decreased in SHR substantially from 35 +/- 3% to 13 +/- 1%. There was a significant correlation between the left ventricular hypertrophy and the percent V3 myosin expression in the SHR during regression (r = 0.697, p less than 0.001). However, only the adult isoforms of tropomyosin and troponin T were detected in the SHR with or without enalapril treatment, and the level of tropomyosin phosphorylation remained constant irrespective of the degree of left ventricular hypertrophy.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Cardiomegalia/patologia , Proteínas Contráteis/metabolismo , Enalapril/farmacologia , Ratos Endogâmicos SHR/fisiologia , Animais , Pressão Sanguínea , Cardiomegalia/etiologia , Cardiomegalia/metabolismo , Ventrículos do Coração , Isoenzimas/metabolismo , Miosinas/metabolismo , Fosforilação , Ratos , Tropomiosina/metabolismo , Troponina/metabolismo , Troponina T
16.
Can Vet J ; 27(5): 224-6, 1986 May.
Artigo em Inglês | MEDLINE | ID: mdl-17422661
17.
Neurosurgery ; 16(6): 754-8, 1985 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-2409471

RESUMO

To assess the quality of long term outcome of civilian gunshot wounds to the head after intensive neurosurgical management, particularly with regard to the possibility of subtle problems due to diffuse injury, we administered neuropsychological tests to six survivors (four adults and two children) at about 1 year after injury. Five patients were moderately disabled, and one patient achieved a good recovery. Residual neurobehavioral sequelae were present in all cases. Defects in long term memory for new information were the most common sequelae, whereas the persistence of linguistic and visuospatial deficits was related to the hemispheric lateralization of injury. In comparison with the outcome reported for patients with closed head injuries who had similar Glasgow coma scale scores, our patients exhibited more severe impairment due to significant focal brain injuries and less evidence of diffuse damage.


Assuntos
Lesões Encefálicas/psicologia , Transtornos Neurocognitivos/psicologia , Testes Neuropsicológicos , Ferimentos por Arma de Fogo/psicologia , Adulto , Afasia/psicologia , Criança , Coma/psicologia , Dominância Cerebral , Feminino , Humanos , Masculino , Prognóstico , Desempenho Psicomotor
18.
Neurosurgery ; 15(1): 34-42, 1984 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-6472592

RESUMO

To try to define the significance of disseminated intravascular coagulation (DIC) in head-injured patients, we correlated clinical, laboratory, and pathological findings in 16 patients with head injury as their main problem who had DIC, who died within 4 days of injury, and who were examined postmortem. Patients were ranked according to the number of abnormal laboratory screening tests for DIC and the severity of these abnormalities. The most frequently abnormal laboratory tests were the fibrinogen degradation products and fibrinogen, followed in order by the activated partial thromboplastin time, prothrombin time, and thrombin time. The platelet count was the least abnormal value. The patients with the fewest abnormalities had the least abnormal computed tomographic scans. Autopsy reports revealed necrosis and bleeding in the brain and in a number of other organs, particularly the lungs. Microthrombi were not reported in the original autopsy reports. However, when these cases were reevaluated and their slides were stained with an immunoperoxidase technique using rabbit anti-human fibrinogen antiserum, microthrombi were seen frequently. Large microthrombi were more common in patients who had died within less than 24 hours, suggesting a relationship to death or to less time for lysis. In order of frequency, the brain/spinal cord, liver, lungs, kidneys, and pancreas were most commonly affected, and the liver, pituitary gland, pancreas, thymus, brain/spinal cord, large intestine, kidneys, and lungs had the greatest density of microthrombi. Pulmonary dysfunction had been a frequent problem in these patients, which may have been related to the high incidence of microthrombi and bleeding found in the lungs.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Lesões Encefálicas/complicações , Encéfalo/patologia , Coagulação Intravascular Disseminada/complicações , Testes de Coagulação Sanguínea , Lesões Encefálicas/sangue , Lesões Encefálicas/patologia , Coagulação Intravascular Disseminada/sangue , Coagulação Intravascular Disseminada/patologia , Produtos de Degradação da Fibrina e do Fibrinogênio/análise , Fibrinogênio/sangue , Humanos
19.
Acta Neurochir (Wien) ; 72(3-4): 197-209, 1984.
Artigo em Inglês | MEDLINE | ID: mdl-6475575

RESUMO

Four per cent (38) of 881 head injured patients developed known subdural hygromas. Their times of onset and course were variable. However, only two large hygromas seemed clinically significant. Hygromas were more frequent when intracranial pressure monitors were placed, possibly due to opening of the arachnoid, particularly if intracranial pressure was low. But, of course, monitors were only inserted in more severely injured patients. The use of Richmond bolts to drain subdural hygromas in a controlled fashion while monitoring intracranial pressure is suggested.


Assuntos
Lesões Encefálicas/complicações , Cistos/cirurgia , Adulto , Lesões Encefálicas/diagnóstico por imagem , Cistos/diagnóstico por imagem , Drenagem , Feminino , Humanos , Pressão Intracraniana , Masculino , Prognóstico , Espaço Subdural , Tomografia Computadorizada por Raios X
20.
J Urol ; 130(3): 440-4, 1983 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-6350614

RESUMO

Digital subtraction angiography was used in 10 renal allograft recipients with sustained hypertension after transplantation to detect transplant renal artery stenosis. Recipients with end-to-end vascular anastomoses were visualized adequately in the anteroposterior projection. Two cases of transplant renal artery stenosis were identified by digital subtraction angiography and then verified by catheter angiography. Patients with end-to-side vascular anastomoses may require additional oblique projections. Digital subtraction angiography is a safe, noninvasive and cost-effective screening procedure to diagnose transplant renal artery stenosis in most recipients. Catheter angiography can be applied more selectively to those recipients with stenosis observed by digital subtraction angiography or when more detailed imaging is required.


Assuntos
Hipertensão Renal/diagnóstico por imagem , Hipertensão Renovascular/diagnóstico por imagem , Transplante de Rim , Obstrução da Artéria Renal/diagnóstico por imagem , Artéria Renal/diagnóstico por imagem , Adolescente , Adulto , Feminino , Humanos , Hipertensão Renovascular/etiologia , Masculino , Métodos , Complicações Pós-Operatórias , Radiografia , Obstrução da Artéria Renal/etiologia , Técnica de Subtração
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...