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1.
Bone Joint J ; 100-B(2): 197-204, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29437062

RESUMO

AIMS: The aims of this study were to compare the mid-term outcomes of patients with late-stage arthritis of the wrist treated with proximal row carpectomy (PRC) and dorsal capsular interposition (DCI) arthroplasty with a matched cohort treated with routine PRC alone. PATIENTS AND METHODS: A total of 25 arthritic wrists (24 patients) with pre-existing degenerative changes of the proximal capitate and/or the lunate fossa of the radius were treated with PRC + DCI over a ten-year period. This group of patients were matched 1:2 with a group of 50 wrists (48 patients) without degenerative changes in the capitate or lunate fossa that were treated with a routine PRC alone during the same period. The mean age of the patients at the time of surgery was 56.8 years (25 to 81), and the demographics and baseline range of movement of the wrist, grip strength, Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score, and Patient-Rated Wrist Evaluation (PRWE) score were similar in both groups. RESULTS: At a mean follow-up of 5.9 years (1.8 to 11.8), significant improvements in mean grip strength, the flexion-extension arc of movement of the wrist, QuickDASH, and PRWE scores were seen in both groups. There was no diifference between the groups for any of the outcomes. One patient in the PRC + DCI group required additional surgery for a deep infection, while two in the PRC group had complications (one wound dehiscence requiring revision closure, one transient radial sensory neuritis). One patient in each group required total arthrodesis of the wrist for progressive degenerative radiocarpal changes. A total of 70 patients (93%) were satisfied with the outcomes. CONCLUSION: PRC with DCI is an effective form of treatment for late-stage arthritis of the wrist involving the capitolunate joint, with mid-term outcomes that are similar to those in patients without degenerative changes affecting the capitate or lunate fossa who are treated with a routine PRC alone. Cite this article: Bone Joint J 2018;100-B:197-204.


Assuntos
Artroplastia/métodos , Ossos do Carpo/cirurgia , Osteoartrite/cirurgia , Articulação do Punho/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Avaliação da Deficiência , Feminino , Seguimentos , Força da Mão , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação do Paciente , Amplitude de Movimento Articular , Retalhos Cirúrgicos , Resultado do Tratamento
2.
Eur J Vasc Endovasc Surg ; 52(2): 173-8, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27346445

RESUMO

OBJECTIVE: Total arch transposition (TAT) during hybrid endovascular repair for aortic arch disease is believed to allow a better landing zone, but also to be associated with higher peri-operative mortality than partial arch transposition (PAT). Information on this issue is limited. METHOD: This study was a retrospective analysis. All 53 consecutive patients with aortic arch disease (41 males, mean age 65.0 years) who underwent hybrid endovascular repair with TAT (zone 0, n=20) or PAT (zone 1 or 2, n=33) from 2008 to 2014 were analyzed retrospectively. The peri-operative and late outcomes of these two groups were compared. RESULTS: Baseline characteristics, including EuroSCORE II results, were similar in the two groups. After procedures, peri-operative mortalities and stroke rates were similar in the two groups (5.0% vs. 9.1%, p=1.000, and 10.0% vs. 6.1%, p=.627). Interestingly, all four strokes occurred in patients with a type III aortic arch irrespective of transposition type. Primary success rates (80.0% vs. 69.7%, p=.527) and type I endoleak incidences (20.0% vs. 27.3%, p=.744) were not significantly different. During follow up (mean duration 36.9 months), overall survival (89.7% vs. 87.4% at 1 year and 89.7% vs. 79.3% at 3 years; p=.375) and re-intervention free survival rates (78.6% vs. 92.0% at 1 year; 72.0% vs. 62.2% at 3 years, p=.872) were similar in the two groups. CONCLUSION: Morbidity and mortality were high within the first year of hybrid endovascular therapy for aortic arch disease, implying that candidates for hybrid procedures need to be selected carefully. Hybrid endovascular repair with TAT was found to have peri-operative mortality, stroke, and long-term survival rates comparable with PAT, so hybrid endovascular repair may be considered, irrespective of type of arch reconstruction, when clinically indicated.


Assuntos
Aorta Torácica/cirurgia , Síndromes do Arco Aórtico/cirurgia , Idoso , Síndromes do Arco Aórtico/mortalidade , Prótese Vascular , Endoleak/etiologia , Procedimentos Endovasculares , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reoperação , Estudos Retrospectivos , Stents , Acidente Vascular Cerebral/etiologia , Enxerto Vascular/efeitos adversos , Enxerto Vascular/métodos , Enxerto Vascular/mortalidade
3.
Eur J Clin Invest ; 39(9): 819-27, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19549173

RESUMO

BACKGROUND: Celastrol, a quinone methide triterpenoid isolated from the Celastraceae family, exhibits various biological properties, including chemopreventive, antioxidant and neuroprotective effects. In this study, we showed that celastrol inhibits inflammatory reactions in macrophages and protects mice from skin inflammation. MATERIALS AND METHODS: Anti-inflammatory effects of celastrol (0-1 microM) were examined in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophages. To investigate the effects of celastrol (0-50 microg per mice) in vivo, activation of myeloperoxidase (MPO) and histological assessment were examined in the 12-O-tetradecanoyl-phorbol-13-acetate (TPA)-induced mouse ear oedema model. RESULTS: Our in vitro experiments showed that celastrol suppressed not only LPS-stimulated generation of nitric oxide and prostaglandin E(2), but also expression of inducible nitric oxide synthase and cyclooxygenase-2 in RAW264.7 cells. Similarly, celastrol inhibited LPS-induced production of inflammatory cytokines, including tumour necrosis factor-alpha and interleukin-6. In an animal model, celastrol protected mice from TPA-induced ear oedema, possibly by inhibiting MPO activity and production of inflammatory cytokines. CONCLUSIONS: Our data suggest that celastrol inhibits the production of inflammatory mediators and is a potential target for the treatment of various inflammatory diseases.


Assuntos
Indolquinonas/metabolismo , Mediadores da Inflamação/metabolismo , Macrófagos/efeitos dos fármacos , Receptores de Prostaglandina E/efeitos dos fármacos , Triterpenos/metabolismo , Animais , Terapias Complementares , Edema/tratamento farmacológico , Imuno-Histoquímica , Indolquinonas/administração & dosagem , Camundongos , NF-kappa B/efeitos dos fármacos , NF-kappa B/metabolismo , Óxido Nítrico/metabolismo , Triterpenos Pentacíclicos , Receptores de Prostaglandina E Subtipo EP2 , Triterpenos/administração & dosagem , Proteínas Quinases p38 Ativadas por Mitógeno/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
4.
Heart ; 95(12): 970-5, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18772180

RESUMO

OBJECTIVE: We compared the degree of systemic inflammation and its relation to the angiographic outcomes after drug-eluting stent (DES) implantations. METHODS: We implanted a single DES in 79 stable angina patients (50 men; 60.4 (9.5) years of age; sirolimus-eluting stent (SES), n = 38; paclitaxel-eluting stent (PES), n = 41). The high-sensitivity C-reactive protein (hs-CRP) and interleukin 6 (IL-6) levels were determined before and at 24 hours, 72 hours, and 4 weeks after the percutaneous coronary intervention (PCI). An angiography and intravascular ultrasound (IVUS) were performed. RESULTS: The hs-CRP and IL-6 levels at baseline did not differ between the two groups. The hs-CRP increased significantly from baseline at 24 hours and 72 hours after the PCI in both groups and there was a significant increase in the IL-6 level at 24 hours after the PCI in both groups. However, there was no significant difference between the two groups in any of the hs-CRP or IL-6 measurements. At follow-up, the late lumen loss was significantly higher in the PES group than in the SES group (0.57 (0.56) mm vs 0.28 (0.58) mm, respectively, p = 0.020). The neointimal hyperplasia (NIH) volume in the PES group was significantly higher than that in the SES group (23.1 (22.7) vs 3.8 (7.1) mm(3), respectively, p = 0.000). The percentage luminal volume reduction was higher in the PES group than in the SES group (18.9 vs 3.9%, p = 0.002). The absolute values or change in the inflammatory markers did not correlate with the NIH or stent volume reduction. CONCLUSIONS: Our study showed that the benefits obtained from the SES, which reduce neointimal proliferation, are not probably mediated by the attenuation of the systemic inflammatory markers hs-CRP or IL-6.


Assuntos
Angioplastia Coronária com Balão/instrumentação , Stents Farmacológicos , Paclitaxel/uso terapêutico , Sirolimo/uso terapêutico , Síndrome de Resposta Inflamatória Sistêmica/prevenção & controle , Idoso , Angioplastia Coronária com Balão/efeitos adversos , Angioplastia Coronária com Balão/métodos , Biomarcadores/sangue , Proteína C-Reativa/metabolismo , Angiografia Coronária , Reestenose Coronária/sangue , Reestenose Coronária/prevenção & controle , Estenose Coronária/diagnóstico por imagem , Estenose Coronária/terapia , Feminino , Seguimentos , Humanos , Mediadores da Inflamação/sangue , Interleucina-6/sangue , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Síndrome de Resposta Inflamatória Sistêmica/sangue , Síndrome de Resposta Inflamatória Sistêmica/etiologia , Resultado do Tratamento , Moduladores de Tubulina/uso terapêutico , Ultrassonografia
5.
J Bone Joint Surg Br ; 88(2): 255-60, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16434534

RESUMO

We have evaluated the clinical outcomes of simple excision, ulnar lengthening and the Sauvé-Kapandji procedure in the treatment of deformities of the forearm in patients with multiple hereditary osteochondromas. The medical records of 29 patients (33 forearms) were reviewed; 22 patients (22 forearms) underwent simple excision (four with ulnar lengthening) and seven the Sauvé-Kapandji procedure. Simple excision increased the mean supination of the forearm from 63.2 degrees to 75.0 degrees (p = 0.049). Ulnar lengthening did not significantly affect the clinical outcome. The Sauvé-Kapandji technique improved the mean pronation from 33.6 degrees to 55.0 degrees (p = 0.047) and supination from 70.0 degrees to 81.4 degrees (p = 0.045). Simple excision may improve the range of movement of the forearm but will not halt the progression of disease, particularly in younger patients. No discernable clinical or radiological improvement was noted with ulnar lengthening. The Sauvé-Kapandji procedure combined with simple excision of osteochondromas can improve stability of the wrist, movement of the forearm and the radiological appearance.


Assuntos
Exostose Múltipla Hereditária/cirurgia , Antebraço/cirurgia , Adolescente , Adulto , Criança , Pré-Escolar , Exostose Múltipla Hereditária/diagnóstico por imagem , Exostose Múltipla Hereditária/fisiopatologia , Antebraço/diagnóstico por imagem , Humanos , Procedimentos Ortopédicos/métodos , Pronação/fisiologia , Radiografia , Rádio (Anatomia)/anormalidades , Rádio (Anatomia)/cirurgia , Amplitude de Movimento Articular/fisiologia , Reoperação , Supinação/fisiologia , Resultado do Tratamento , Ulna/anormalidades , Ulna/cirurgia
6.
Int J Cardiol ; 81(1): 43-50, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11690664

RESUMO

BACKGROUND: Vascular inflammation plays an important role in the pathogenesis of atherosclerosis. We investigated the effect of hormone replacement therapy (HRT) on vasomotor function and monocyte chemoattractant protein (MCP)-1 levels, an important serological marker of inflammation. METHODS: We administered micronized progesterone (MP) 200 mg for 10 days with conjugated equine estrogen (CEE) 0.625 mg for 25 days and remaining 5 days off cyclically during 2 months to 20 healthy postmenopausal women (PMW). We measured NO bioactivity and plasma levels of MCP-1 before and after HRT in 20 PMW. And we measured plasma levels of MCP-1 in each 20 subjects of premenopausal women, men <50, and men >50 years, respectively. RESULTS: MP combined with CEE significantly improved the percent flow-mediated dilator response to hyperemia relative to baseline measurements (P<0.001). PMW receiving HRT had lower levels of MCP-1 than those not receiving HRT (121+/-38 versus 146+/-44 pg/ml, P<0.001). In all comparisons, subjects with high estrogen status had significantly lower MCP-1 levels than subjects with low estrogen status (P<0.001 by ANOVA). Premenopausal women had lower levels of MCP-1 than men of a similar age (106+/-14 versus 164+/-40 pg/ml, P<0.001). PMW not receiving HRT had similar levels of MCP-1 compared with men of a similar age (146+/-44 versus 143+/-29 pg/ml, P=0.816). Premenopausal women had markedly lower levels of MCP-1 than PMW not receiving HRT (106+/-14 versus 146+/-44 pg/ml, P=0.001). PMW receiving HRT had similar levels of MCP-1 compared with premenopausal women (121+/-38 versus 106+/-14 pg/ml, P=0.323). CONCLUSION: These findings might provide at least a partial explanation for the protection against cardiovascular disease experienced by premenopausal women, and the loss of that protection following menopause.


Assuntos
Doenças Cardiovasculares/metabolismo , Quimiocina CCL2/sangue , Estrogênios Conjugados (USP)/metabolismo , Terapia de Reposição Hormonal , Óxido Nítrico/metabolismo , Progesterona/metabolismo , Fatores Etários , Análise de Variância , Artéria Braquial/diagnóstico por imagem , Artéria Braquial/metabolismo , Doenças Cardiovasculares/diagnóstico por imagem , Endotélio Vascular/diagnóstico por imagem , Endotélio Vascular/metabolismo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pós-Menopausa/metabolismo , Pré-Menopausa/metabolismo , Fatores Sexuais , Ultrassonografia
7.
Coron Artery Dis ; 12(4): 305-11, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11428539

RESUMO

BACKGROUND: Results of clinical trials of statin therapy demonstrate that an improvement in incidence of cardiovascular end points and coronary stenosis can be achieved. The beneficial effects of statins on clinical events may involve nonlipid mechanisms that affect endothelial function, such as inflammatory responses, formation of thrombi, and stabilization of plaque. OBJECTIVE: To investigate levels of serologic markers, which may be useful surrogates for activity of vascular disease after administration of statin. METHODS: We administered 20-40 mg simvastatin daily for 14 weeks to 13 patients established to have coronary artery disease who remained hypercholesterolemic during step-II diet therapy. RESULTS: Administration of simvastatin significantly lowered lipoprotein levels and the low: high-density lipoprotein cholesterol level ratio and apolipoprotein B:A-I level ratio compared with pretreatment values (P < 0.01). Administration of simvastatin significantly lowered plasma levels of matrix metalloproteinase-9 (MMP-9) and monocyte chemoattractant protein-I [33+/-46 and 13+/-19%, respectively (P = 0.027 and 0.020, respectively)]. Furthermore, administration of simvastatin tended to lower plasma levels of plasminogen activator inhibitor type-1 and tumor necrosis factor-alpha [by 20+/-44 and 13+/-29%, respectively (P= 0.066 and 0.110, respectively)]. There were significant inverse correlations between pretreatment levels of MMP-9 and the degree of change in those levels after administration of simvastatin (r = -0.714, P= 0.005). However, there was no significant correlation between levels of lipoprotein and levels of MMP-9, monocyte chemoattractant protein-I, and plasminogen activator inhibitor type-1 during administration of simvastatin. CONCLUSIONS: Our current data support the hypothesis that nonlipid mechanisms elicited by administration of simvastatin contribute to the decrease in incidence of cardiovascular events and explain the early clinical benefit observed in clinical trials, independent of changes in levels of lipoprotein.


Assuntos
Anticolesterolemiantes/farmacologia , Arteriosclerose/sangue , Colesterol/sangue , Doença da Artéria Coronariana/sangue , Hipercolesterolemia/tratamento farmacológico , Sinvastatina/farmacologia , Triglicerídeos/sangue , Idoso , Biomarcadores/sangue , Quimiocina CCL2/sangue , HDL-Colesterol/sangue , LDL-Colesterol/sangue , Interpretação Estatística de Dados , Endotélio Vascular/efeitos dos fármacos , Humanos , Hipercolesterolemia/sangue , Metaloproteinase 9 da Matriz/sangue , Pessoa de Meia-Idade , Fator de Necrose Tumoral alfa/metabolismo
8.
Yale J Biol Med ; 74(2): 101-5, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11393261

RESUMO

A 66-year-old female presented with a large abdominal mass and accompanying systemic complaints of abdominal pain, constipation. and fever. On exploratory laparotomy, the mass was found to be a moderately differentiated adenocarcinoma of the sigmoid colon with metastasis to the left ovary. A primary colorectal carcinoma that has metastasized to the ovaries can be difficult to distinguish clinically from an advanced primary ovarian tumor. Histology and tumor markers are currently the most useful tools available in making an accurate diagnosis. If the nature of the primary tumor is uncertain and the initial response to chemotherapy is poor, the patient's prognosis will also he poor. Though controversy exists regarding the role of prophylactic bilateral oophorectomy during resection for primary colorectal cancer, later confusion can be avoided by performing this procedure when the colorectal carcinoma is first diagnosed. However the possibility of a concurrent primary ovarian tumor must not be overlooked.


Assuntos
Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/cirurgia , Neoplasias Ovarianas/secundário , Ovariectomia , Neoplasias do Colo Sigmoide/tratamento farmacológico , Neoplasias do Colo Sigmoide/cirurgia , Adenocarcinoma/patologia , Idoso , Feminino , Humanos , Neoplasias Ovarianas/prevenção & controle , Neoplasias do Colo Sigmoide/patologia
9.
Yale J Biol Med ; 74(2): 107-10, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11393262

RESUMO

A patient presented with deep venous thrombosis and an elevated CA-125 level, but normal pelvic ultrasound and abdominal and pelvic CT scans. Laparoscopy revealed diffuse carcinomatosis and a diagnosis of stage IIIc, poorly differentiated epithelial ovarian carcinoma was made. Laparoscopy may provide an alternative means of diagnosis when conventional imaging fails, and may facilitate the placement of catheters for subsequent intraperitoneal therapy.


Assuntos
Carcinoma/diagnóstico , Carcinoma/terapia , Neoplasias Peritoneais/diagnóstico , Neoplasias Peritoneais/terapia , Antineoplásicos/uso terapêutico , Carcinoma/secundário , Feminino , Humanos , Laparoscopia , Pessoa de Meia-Idade , Neoplasias Ovarianas/patologia , Neoplasias Peritoneais/secundário
10.
Circulation ; 103(15): 1961-6, 2001 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-11306524

RESUMO

BACKGROUND: Synthetic, not natural, progestagen may negate the favorable effects of estrogen. Nonetheless, observational studies report no differences in risk for clinical cardiovascular events between users of unopposed estrogen and users of estrogen combined with synthetic progestin. METHODS AND RESULTS: In a double-blind study, we randomly assigned 20 healthy postmenopausal women to micronized progesterone (MP) 200 mg or medroxyprogesterone acetate (MPA) 10 mg for 10 days with conjugated equine estrogen (CEE) 0.625 mg for 25 days and the remaining 5 days off cyclically during 2 months, followed by crossover to the alternate therapy. CEE+MP and CEE+MPA significantly improved the percent flow-mediated dilator response to hyperemia relative to baseline measurements (P=0.004 by ANOVA) by a similar degree (P=0.863). Both therapies significantly decreased E-selectin, intercellular adhesion molecule (ICAM)-1, and vascular cell adhesion molecule (VCAM)-1 levels from baseline values (P<0.001, P=0.048, and P=0.016 by ANOVA, respectively) by a similar degree (P=0.977 for ICAM-1 and P=0.541 for VCAM-1, respectively). CEE+MPA decreased E-selectin levels more than CEE+MP did (P=0.040). Both therapies significantly decreased monocyte chemoattractant protein-1 levels from baseline values (P<0.005 by ANOVA) by a similar degree (P=0.194). Both therapies significantly decreased tissue factor antigen and increased tissue factor activity levels from baseline values (P=0.003 and P<0.001 by ANOVA, respectively) by a similar degree (P=0.652 for antigen and P=0.173 for activity). Both therapies significantly lowered plasma plasminogen activator inhibitor-1 levels from baseline values (P<0.001 by ANOVA) by a similar degree (P=0.533). CONCLUSIONS: CEE+MP and CEE+MPA provide similar improvement in endothelium-dependent vasodilator responsiveness and effects on markers of inflammation, hemostasis, and fibrinolysis inhibition in healthy postmenopausal women.


Assuntos
Estrogênios Conjugados (USP)/administração & dosagem , Acetato de Medroxiprogesterona/administração & dosagem , Progesterona/administração & dosagem , Vasodilatação/efeitos dos fármacos , Quimiocina CCL2/sangue , Estudos Cross-Over , Método Duplo-Cego , Esquema de Medicação , Quimioterapia Combinada , Selectina E/sangue , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/metabolismo , Estrogênios Conjugados (USP)/síntese química , Feminino , Fibrinólise/efeitos dos fármacos , Hemostasia/efeitos dos fármacos , Humanos , Molécula 1 de Adesão Intercelular/sangue , Pessoa de Meia-Idade , Inibidor 1 de Ativador de Plasminogênio/sangue , Pós-Menopausa , Congêneres da Progesterona/administração & dosagem , Progestinas/administração & dosagem , Tromboplastina/metabolismo , Molécula 1 de Adesão de Célula Vascular/sangue
11.
J Invasive Cardiol ; 11(5): 301-4, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10745536

RESUMO

Direct surgical angioplasty or coronary artery bypass graft has been done in patients who have left main coronary ostial stenosis. Recent reports have demonstrated that stenting of unprotected left main coronary artery stenosis has been attempted as an alternative to bypass surgery in selected patients with normal LV function. We report two patients with isolated left main coronary ostial stenosis who are undergoing primary and elective stenting, respectively. Major cardiac events did not occur during a 3-month follow-up. This study suggests that stenting of isolated left main coronary ostial stenosis in acute coronary syndrome is feasible and results in excellent outcomes.


Assuntos
Angioplastia Coronária com Balão , Estenose Coronária/terapia , Stents , Doença Aguda , Adulto , Angiografia Coronária , Estenose Coronária/complicações , Estenose Coronária/diagnóstico por imagem , Feminino , Humanos , Masculino , Isquemia Miocárdica/complicações , Síndrome
12.
Int J Cardiol ; 65(3): 295-300, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9740488

RESUMO

We report a patient with Takayasu's arteritis who had recurrent restenosis following intracoronary bifurcation stenting of proximal left anterior descending and first diagonal arteries, and rotational atherectomy for in-stent restenosis. After all, the patient underwent coronary artery bypass grafts (CABG) and has remained asymptomatic during 3 months without damaging myocardium. We suggest that endoluminal stenting or rotational atherectomy may be an alternative treatment for the patients with coronary artery stenosis due to active Takayasu's arteritis as a therapy to postpone CABG.


Assuntos
Aterectomia Coronária , Doença das Coronárias , Stents , Arterite de Takayasu/complicações , Adulto , Angioplastia Coronária com Balão , Aterectomia Coronária/efeitos adversos , Aterectomia Coronária/métodos , Ponte de Artéria Coronária , Doença das Coronárias/etiologia , Doença das Coronárias/cirurgia , Feminino , Seguimentos , Humanos , Recidiva , Stents/efeitos adversos , Resultado do Tratamento
13.
J Biol Chem ; 271(21): 12261-8, 1996 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-8647824

RESUMO

Because of its expression in numerous cells, the herpes simplex virus thymidine kinase promoter (HSV-TK) is one of the best characterized promoters. Using the HSV-TK promoter as a model system, we have defined a new mode of E2F-1 transcriptional activation which utilizes the N-terminal region of E2F-1. We demonstrate that E2F-1 strongly activated HSV-TK, but in the absence of consensus E2F DNA elements. Nonetheless, E2F-1 could bind to GC-rich elements, which were conclusively identified in classic studies of HSV-TK as SP-1 sites. Second, the transcriptional activation of HSV-TK required the entire E2F-1 protein, including the N-terminal 89 amino acids. In contrast, the N-terminal 89 amino acids of E2F-1 were dispensable for transcriptional activation through consensus E2F sites. Third, we demonstrated that S phase entry is not sufficient for activation of HSV-TK by E2F-1, while the activation through consensus E2F sites is strictly linked to the cell cycle. Taken together, the activation of HSV-TK by E2F-1 proceeds by a different mechanism directed in part through the N-terminal region of E2F-1 and may be uncoupled from the known cell cycle regulatory role.


Assuntos
Proteínas de Transporte , Proteínas de Ciclo Celular , Proteínas de Ligação a DNA , Regiões Promotoras Genéticas , Fatores de Transcrição/metabolismo , Ativação Transcricional , Sequência de Bases , Ciclo Celular , Sequência Consenso , DNA , Fatores de Transcrição E2F , Fator de Transcrição E2F1 , Ativação Enzimática , Humanos , Dados de Sequência Molecular , Proteína 1 de Ligação ao Retinoblastoma , Simplexvirus/enzimologia , Simplexvirus/genética , Timidina Quinase/genética , Timidina Quinase/metabolismo , Fator de Transcrição DP1 , Células Tumorais Cultivadas
14.
Mol Cell Biol ; 15(4): 2252-62, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7891719

RESUMO

We have examined regulation of the E2F transcription factor during differentiation of muscle cells. E2F regulates many genes involved in growth control and is also the target of regulation by diverse cellular signals, including the RB family of growth suppressors (e.g., the retinoblastoma protein [RB], p107, and p130). The following aspects of E2F function and regulation during muscle differentiation were investigated: (i) protein-protein interactions, (ii) protein levels, (iii) phosphorylation of the E2F protein, and (iv) transcriptional activity. A distinct E2F complex was present in differentiated cells but not in undifferentiated cells. The p130 protein was a prominent component of the E2F complex associated with differentiation. In contrast, in undifferentiated cells, the p107 protein was the prominent component in one of three E2F complexes. In addition, use of a differentiation-defective muscle line provided genetic and biochemical evidence that quiescence and differentiation are separable events. Exclusive formation of the E2F-p130 complex did not occur in this differentiation-defective line; however, E2F complexes diagnostic of quiescence were readily apparent. Thus, sole formation of the E2F-p130 complex is a necessary event in terminal differentiation. Other changes in E2F function and regulation upon differentiation include decreased phosphorylation and increased repression by E2F. These observations suggest that the regulation of E2F function during terminal differentiation may proceed through differential interaction within the RB family and/or phosphorylation.


Assuntos
Proteínas de Transporte , Proteínas de Ciclo Celular , Proteínas de Ligação a DNA , Músculos/fisiologia , Fosfoproteínas , Fatores de Transcrição/metabolismo , Diferenciação Celular , Células Cultivadas , Fatores de Transcrição E2F , Regulação da Expressão Gênica , Substâncias Macromoleculares , Modelos Biológicos , Músculos/citologia , Proteínas Nucleares/metabolismo , Fosforilação , Ligação Proteica , Proteínas/metabolismo , Proteínas Recombinantes de Fusão/biossíntese , Proteína do Retinoblastoma/metabolismo , Proteína 1 de Ligação ao Retinoblastoma , Proteína p130 Retinoblastoma-Like , Fator de Transcrição DP1 , Fatores de Transcrição/química , Fatores de Transcrição/genética , Transcrição Gênica
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