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1.
J Vasc Surg Cases Innov Tech ; 9(4): 101318, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38106355

RESUMO

Tunneled catheters are frequently used in patients with end-stage renal disease who require hemodialysis access. Catheter-related atrial thrombus is a documented complication of prolonged catheter use. The incidence of catheter-related atrial thrombus is 2% to 29%, with a high mortality rate approaching 20%, raising concerns for serious complications and death in the absence of an established universal management plan. This case series demonstrates the successful use of a minimally invasive approach to treat patients with intracardiac thrombus and high perioperative risk factors using mechanical and aspiration thrombectomy with the FlowTriever system (Inari Medical).

3.
Cardiovasc Revasc Med ; 27: 1-6, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33129688

RESUMO

BACKGROUND/PURPOSE: This sub-analysis of the prospective Low Risk TAVR (LRT) trial determined anatomical characteristics associated with hypoattenuated leaflet thickening (HALT), which may contribute to early transcatheter heart valve (THV) degeneration. METHODS/MATERIALS: The LRT trial enrolled 200 low-risk patients between February 2016 and February 2018. All subjects underwent baseline and 30-day CT studies, analyzed by an independent core laboratory. Additional measurements, namely THV expansion, eccentricity, depth, and commissural alignment, were made by consensus of three independent readers. HALT was observed only in the Sapien 3 THV, so Evolut valves were excluded from this analysis. RESULTS: In the LRT trial, 177 subjects received Sapien 3 THVs, of whom 167 (94.3%) had interpretable 30-day CTs and were eligible for this analysis. Twenty-six subjects had HALT (15.6%). Baseline characteristics were similar between groups. There was no difference in THV size implanted and baseline aortic-root geometry between groups. In patients who developed HALT, THV implantation depth was shallower than in patients who did not develop HALT (2.6 ± 1.1 mm HALT versus 3.3 ± 1.8 mm no-HALT, p = 0.03). There were more patients in the HALT group with commissural malalignment (40% vs. 28%; p = 0.25), but this did not reach statistical significance. In a univariable regression model, no predetermined variables were shown to independently predict the development of HALT. CONCLUSIONS: This study did not find anatomical or THV implantation characteristics that predicted the development of HALT at 30 days. This study cannot exclude subtle effects or interaction between factors because of the small number of events.


Assuntos
Estenose da Valva Aórtica , Próteses Valvulares Cardíacas , Substituição da Valva Aórtica Transcateter , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/cirurgia , Estenose da Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/cirurgia , Humanos , Estudos Prospectivos , Desenho de Prótese , Substituição da Valva Aórtica Transcateter/efeitos adversos , Resultado do Tratamento
4.
Cardiovasc Revasc Med ; 21(8): 959-963, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32387217

RESUMO

BACKGROUND: The advent of transcatheter aortic valve replacement (TAVR) has changed which patients undergo surgical aortic valve replacement (SAVR). We sought to understand the impact of TAVR on the characteristics of SAVR patients in the United States. METHODS: A cohort of 2959 patients who underwent isolated SAVR at 11 US hospitals that perform both TAVR and SAVR from 2013 through 2017 were grouped by the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database version (v)2.73 (2011-2014), v2.81 (2014-2017), and v2.9 (2017) to assess temporal trends in patient characteristics. RESULTS: Over time, SAVR patients were younger with fewer preoperative comorbidities. There was a significant decrease in median STS predicted risk of mortality (PROM) score (2.0 vs. 1.8 vs. 1.3, p < 0.001, in v2.73 vs. v2.81 vs. v2.9). Specifically, there were fewer high-risk (STS PROM > 8%: 4.3% vs. 4.7% vs. 1.2%, p = 0.03) and intermediate-risk (STS PROM 4% to 8%: 16.3% vs. 11.7% vs. 4.3%, p < 0.001) patients. The proportion of patients with bicuspid aortic valve disease increased significantly (11.2% vs. 26.9% vs. 36.6%, p < 0.001). There were no differences in operative mortality (1.9% vs. 2.1% vs. 1.4%, p = 0.75). CONCLUSIONS: The introduction of TAVR has already impacted the demographics, clinical characteristics and risk profiles of patients undergoing SAVR in the US. Now that TAVR is approved for low-risk patients, SAVR is likely to be reserved for younger patients who are willing to receive a mechanical valve and for patients with aortopathy, coronary artery disease, or concomitant mitral or tricuspid pathology.


Assuntos
Valva Aórtica/cirurgia , Doenças das Valvas Cardíacas/cirurgia , Implante de Prótese de Valva Cardíaca/tendências , Substituição da Valva Aórtica Transcateter/tendências , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/fisiopatologia , Tomada de Decisão Clínica , Comorbidade , Bases de Dados Factuais , Feminino , Doenças das Valvas Cardíacas/diagnóstico por imagem , Doenças das Valvas Cardíacas/mortalidade , Doenças das Valvas Cardíacas/fisiopatologia , Próteses Valvulares Cardíacas/tendências , Implante de Prótese de Valva Cardíaca/efeitos adversos , Implante de Prótese de Valva Cardíaca/instrumentação , Implante de Prótese de Valva Cardíaca/mortalidade , Humanos , Masculino , Pessoa de Meia-Idade , Medição de Risco , Fatores de Risco , Fatores de Tempo , Substituição da Valva Aórtica Transcateter/efeitos adversos , Substituição da Valva Aórtica Transcateter/instrumentação , Substituição da Valva Aórtica Transcateter/mortalidade , Resultado do Tratamento , Estados Unidos
5.
JACC Cardiovasc Interv ; 13(6): 726-735, 2020 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-32192693

RESUMO

OBJECTIVES: The aim of this study was to evaluate the feasibility of coronary access and aortic valve reintervention in low-risk patients undergoing transcatheter aortic valve replacement (TAVR) with a balloon-expandable transcatheter heart valve (THV). BACKGROUND: Younger, low-risk TAVR patients are more likely than older, higher risk patients to require coronary angiography, percutaneous coronary intervention, or aortic valve reintervention, but their THVs may impede coronary access and cause coronary obstruction during TAVR-in-TAVR. METHODS: The LRT (Low Risk TAVR) trial (NCT02628899) enrolled 200 subjects with symptomatic severe aortic stenosis to undergo TAVR using commercially available THVs. Subjects who received balloon-expandable THVs and who had 30-day cardiac computed tomographic scans were included in this study. In a subgroup, the feasibility of intentional THV crimping on the delivery catheter to pre-determine commissural alignment was tested. RESULTS: In the LRT trial, 168 subjects received balloon-expandable THVs and had 30-day cardiac computed tomographic scans, of which 137 were of adequate image quality for analysis. The most challenging anatomy for coronary access (THV frame above and commissural suture post in front of a coronary ostium) was observed in 9% to 13% of subjects. Intentional THV crimping did not appear to meaningfully affect commissural alignment. The THV frame extended above the sinotubular junction in 21% of subjects, and in 13%, the distance between the THV and the sinotubular junction was <2 mm, signifying that TAVR-in-TAVR may not be feasible without causing coronary obstruction. CONCLUSIONS: TAVR may present challenges to future coronary access and aortic valve reintervention in a substantial number of low-risk patients.


Assuntos
Estenose da Valva Aórtica/cirurgia , Valva Aórtica/cirurgia , Bioprótese , Cateterismo Cardíaco , Estenose Coronária/etiologia , Vasos Coronários , Próteses Valvulares Cardíacas , Substituição da Valva Aórtica Transcateter/instrumentação , Idoso , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/fisiopatologia , Estenose da Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/fisiopatologia , Cateterismo Cardíaco/efeitos adversos , Angiografia por Tomografia Computadorizada , Angiografia Coronária , Estenose Coronária/diagnóstico por imagem , Vasos Coronários/diagnóstico por imagem , Estudos de Viabilidade , Feminino , Humanos , Masculino , Tomografia Computadorizada Multidetectores , Valor Preditivo dos Testes , Estudos Prospectivos , Desenho de Prótese , Retratamento , Fatores de Risco , Índice de Gravidade de Doença , Fatores de Tempo , Substituição da Valva Aórtica Transcateter/efeitos adversos , Resultado do Tratamento , Estados Unidos
6.
Am J Cardiol ; 125(8): 1216-1221, 2020 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-32087995

RESUMO

We aimed to evaluate the burden of coronary artery disease (CAD) using the computed tomography (CT) Leaman score in low-risk transcatheter aortic valve implantation (TAVI) patients. The extent of CAD in low-risk patients with aortic stenosis who are candidates for TAVI has not been accurately quantified. The CT Leaman score was developed to quantify coronary CT angiography (CCTA) atherosclerotic burden and has been validated to evaluate the extent of CAD. CT Leaman score >5 has been associated with an increase in major adverse cardiac events over long-term follow-up. The study population included patients enrolled in the Low Risk TAVI trial who underwent CCTA before the procedure. For the CT Leaman score, we used 3 sets of weighting factors: (1) location of coronary plaques, (2) type of plaque, and (3) degree of stenosis. A total of 200 patients were enrolled in the Low Risk TAVI trial. Excluded were 31 patients who had no analyzable CCTA imaging. For the remaining 169 patients, the mean CT Leaman score was 6.27 ± 0.27, of whom 102 (60.4%) had CT Leaman score >5. Nearly all analyzed patients (97%) had coronary plaques. Furthermore, 33 patients (19.5%) had potentially obstructive coronary plaques (>50% stenosis by CCTA) in proximal segments. Most low-risk TAVI patients have significant CAD burden by CCTA. It should be a priority for future TAVI devices to guarantee unimpeded access to the coronary arteries for selective angiography and interventions.


Assuntos
Estenose da Valva Aórtica/epidemiologia , Doença da Artéria Coronariana/epidemiologia , Estenose Coronária/epidemiologia , Placa Aterosclerótica/epidemiologia , Substituição da Valva Aórtica Transcateter , Idoso , Estenose da Valva Aórtica/cirurgia , Comorbidade , Angiografia por Tomografia Computadorizada/métodos , Doença da Artéria Coronariana/diagnóstico por imagem , Estenose Coronária/diagnóstico por imagem , Feminino , Próteses Valvulares Cardíacas , Humanos , Masculino , Placa Aterosclerótica/diagnóstico por imagem , Cuidados Pré-Operatórios , Prevalência , Ajuste de Prótese , Medição de Risco , Tomografia Computadorizada por Raios X
7.
Circ Cardiovasc Imaging ; 12(12): e009608, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31826675

RESUMO

BACKGROUND: This analysis evaluated echocardiographic predictors of hypoattenuated leaflet thickening (HALT) in low-risk patients undergoing transcatheter aortic valve replacement and assessed 1-year clinical and hemodynamic consequences. HALT by computed tomography may be associated with early valve degeneration and increased neurological events. METHODS: Echocardiograms were performed at baseline, discharge, 30 days, and 1 year post-procedure. Four-dimensional contrast-enhanced computed tomography assessed HALT at 30 days. Independent core laboratories analyzed images. Doppler hemodynamic parameters were tested in a univariable regression model to identify HALT predictors. One-year clinical and hemodynamic outcomes were compared between HALT (+) and (-) patients. RESULTS: Analysis included 170 patients with Sapien 3 valves and diagnostic 30-day computed tomographies, of whom 27 (16%) had HALT. Baseline characteristics were similar between groups. After transcatheter aortic valve replacement, aortic flow was nonsignificantly reduced in patients who developed HALT. Regression analysis did not show significant association between baseline or discharge valve hemodynamics and development of HALT at 30 days. Patients with HALT had smaller aortic valve areas (1.4±0.4 versus 1.7±0.5 cm2; P=0.018) and Doppler velocity index (0.4±0.1 versus 0.5±0.1; P=0.003) than those without HALT at 30 days but not at 1 year. There was no difference in aortic mean gradient at 30 days. There was no difference between the groups in New York Heart Association class, 6-minute walk distance, and mortality at 1 year. CONCLUSIONS: There were no early hemodynamic predictors of HALT. At 30 days, patients with HALT had worse valve hemodynamics than those without HALT, but hemodynamic and clinical outcomes at 1 year were similar. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT02628899.


Assuntos
Estenose da Valva Aórtica/cirurgia , Valva Aórtica/cirurgia , Próteses Valvulares Cardíacas , Hemodinâmica , Trombose/etiologia , Substituição da Valva Aórtica Transcateter/efeitos adversos , Substituição da Valva Aórtica Transcateter/instrumentação , Idoso , Idoso de 80 Anos ou mais , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/fisiopatologia , Estenose da Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/fisiopatologia , Ecocardiografia Doppler , Feminino , Tomografia Computadorizada Quadridimensional , Humanos , Masculino , Valor Preditivo dos Testes , Estudos Prospectivos , Falha de Prótese , Medição de Risco , Fatores de Risco , Trombose/diagnóstico por imagem , Trombose/fisiopatologia , Fatores de Tempo , Resultado do Tratamento , Estados Unidos
8.
JACC Cardiovasc Interv ; 12(10): 901-907, 2019 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-30860059

RESUMO

OBJECTIVES: This study sought to evaluate clinical outcomes and transcatheter heart valve hemodynamics at 1 year after transcatheter aortic valve replacement (TAVR) in low-risk patients. BACKGROUND: Early results from the LRT (Low Risk TAVR) trial demonstrated that TAVR is safe in patients with symptomatic severe aortic stenosis who are at low risk for surgical valve replacement. METHODS: The LRT trial was an investigator-initiated, prospective, multicenter study and was the first Food and Drug Administration-approved Investigational Device Exemption trial to evaluate feasibility of TAVR in low-risk patients. The primary endpoint was all-cause mortality at 30 days. Secondary endpoints included clinical outcomes and valve hemodynamics at 1 year. RESULTS: The LRT trial enrolled 200 low-risk patients with symptomatic severe AS to undergo TAVR at 11 centers. Mean age was 73.6 years and 61.5% were men. At 30 days, there was zero mortality, zero disabling stroke, and low permanent pacemaker implantation rate (5.0%). At 1-year follow-up, mortality was 3.0%, stroke rate was 2.1%, and permanent pacemaker implantation rate was 7.3%. Two (1.0%) subjects underwent surgical reintervention for endocarditis. Of the 14% of TAVR subjects who had evidence of hypoattenuated leaflet thickening at 30 days, there was no impact on valve hemodynamics at 1 year, but the stroke rate was numerically higher (3.8% vs. 1.9%; p = 0.53). CONCLUSIONS: TAVR in low-risk patients with symptomatic severe aortic stenosis appears to be safe at 1 year. Hypoattenuated leaflet thickening, observed in a minority of TAVR patients at 30 days, did not have an impact on valve hemodynamics in the longer term.


Assuntos
Estenose da Valva Aórtica/cirurgia , Valva Aórtica/cirurgia , Substituição da Valva Aórtica Transcateter , Idoso , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/fisiopatologia , Estenose da Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/mortalidade , Estenose da Valva Aórtica/fisiopatologia , Estudos de Viabilidade , Feminino , Hemodinâmica , Humanos , Masculino , Complicações Pós-Operatórias/etiologia , Estudos Prospectivos , Recuperação de Função Fisiológica , Medição de Risco , Fatores de Risco , Fatores de Tempo , Substituição da Valva Aórtica Transcateter/efeitos adversos , Substituição da Valva Aórtica Transcateter/mortalidade , Índices de Gravidade do Trauma , Resultado do Tratamento , Estados Unidos
9.
J Am Coll Cardiol ; 72(18): 2095-2105, 2018 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-30170075

RESUMO

BACKGROUND: Transcatheter aortic valve replacement (TAVR) is now the standard of care for patients with symptomatic severe aortic stenosis who are extreme, high, or intermediate risk for surgical aortic valve replacement (SAVR). OBJECTIVES: The authors sought to evaluate TAVR in a prospective multicenter trial involving low-risk patients. METHODS: The Low Risk TAVR (Feasibility of Transcatheter Aortic Valve Replacement in Low-Risk Patients With Symptomatic, Severe Aortic Stenosis) trial was the first U.S. Food and Drug Administration-approved Investigational Device Exemption trial to enroll in the United States. This investigator-led trial was a prospective, multicenter, unblinded, comparison to historical controls from the Society of Thoracic Surgeons (STS) database. The primary endpoint was all-cause mortality at 30 days. RESULTS: The authors enrolled 200 low-risk patients with symptomatic severe aortic stenosis at 11 centers to undergo TAVR. The authors compared outcomes with an inverse probability weighting-adjusted control cohort of 719 patients who underwent SAVR at the same institutions using the STS database. At 30 days, there was zero all-cause mortality in the TAVR group versus 1.7% mortality in the SAVR group. There was zero in-hospital stroke rate in the TAVR group versus 0.6% stroke in the SAVR group. Permanent pacemaker implantation rates were similar between TAVR and SAVR (5.0% vs. 4.5%). The rates of new-onset atrial fibrillation (3.0%) and length of stay (2.0 ± 1.1 days) were low in the TAVR group. One patient (0.5%) in the TAVR group had >mild paravalvular leak at 30 days. Fourteen percent of TAVR patients had evidence of subclinical leaflet thrombosis at 30 days. CONCLUSIONS: TAVR is safe in low-risk patients with symptomatic severe aortic stenosis, with low procedural complication rates, short hospital length of stay, zero mortality, and zero disabling stroke at 30 days. Subclinical leaflet thrombosis was observed in a minority of TAVR patients at 30 days. (Feasibility of Transcatheter Aortic Valve Replacement in Low-Risk Patients With Symptomatic, Severe Aortic Stenosis [Low Risk TAVR; NCT02628899).


Assuntos
Estenose da Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/cirurgia , Índice de Gravidade de Doença , Substituição da Valva Aórtica Transcateter/métodos , Idoso , Idoso de 80 Anos ou mais , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco
10.
Artigo em Inglês | MEDLINE | ID: mdl-26874705

RESUMO

OPINION STATEMENT: The dilemma of the patient with both AS and LVOTO is now commonly encountered in clinical practice; indeed, physicians must be aware of the complex interaction and coexistent nature of both diseases, especially as both HOCM and TAVR have increased in awareness and prevalence. Importantly, the clinician must be aware of the complex interplay hemodynamically, with the two diseases confusing the TTE imaging and potentially affecting each other anatomically and clinically. There is no set guideline on how to approach this from a surgical or percutaneous approach, but we have outlined a set of recommendations which should serve the clinician and patient well. The three cases that are presented illustrate that methodical diagnosis in addition to the order of treatment do indeed matter. In the first case, there was AS and an underestimated LVOT gradient that was also present. Once the AS was corrected, the true LVOT gradient potential was evidenced and she decompensated, likely because there was a rapid decrease in afterload. Patients with concomitant LVOTO are not able to adjust quickly to the hemodynamic changes created by the rapid decline in afterload, as, for example, in HOCM patients who receive nitroglycerin. The second case demonstrated that when the LVOTO was severe and the AS nonsignificant (mild or moderate), the patient was able to live without symptoms for several years after successful alcohol septal ablation (ASA). She eventually needed an aortic valve and mitral valve replacement but that was postponed for several years until the AS became more significant, and the surgical risk was lowered by the elimination of the need for concomitant myectomy. In the last case, the patient was able to have both an ASA and TAVR within 3 months of each other without hemodynamic compromise. Indeed, this latter therapy sequence may be the best way to treat patients with both diseases in the future, as both ASA and TAVR continue to evolve into intermediate and lower-risk patient populations and the safety of ASA continues to be evident.

11.
Microsurgery ; 33(7): 560-6, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24014308

RESUMO

Reconstruction of bony defects in the surgical management of vertebral osteomyelitis is a challenging endeavor. Our objective is to report the use of intra-abdominal vessels as the recipient vessels for microanastomosis of vascularized bone graft and the use of a spinal cage for fixation. Three patients failed conservative treatment for vertebral osteomyelitis and suffered pathologic fracture. Their treatment consisted of staged posterior irrigation and debridement with segmental fixation, followed by a thoracoabdominal approach multiple-level corpectomy. Reconstruction was performed with a free vascularized fibular graft placed within a custom, expandable cage. The vascularized fibular graft was anastomosed to an intra-abdominal recipient vessel. All patients improved clinically with no neurologic deficits noted. All showed evidence of successful fusion. Free vascularized bone grafts continue to be an excellent option for multi-level spinal defects related to osteomyelitis. Intra-abdominal recipient vessels are appropriate recipient vessels, as their diameter, length, and accessibility allow vascularized bone graft reconstruction of vertebral column defects of the thoracolumbar region. These vessels are also easily accessible and the anastomoses can be performed in the superficial operating incision.


Assuntos
Abdome/irrigação sanguínea , Transplante Ósseo/métodos , Fíbula/irrigação sanguínea , Fíbula/transplante , Osteomielite/cirurgia , Procedimentos de Cirurgia Plástica/métodos , Espondilite/cirurgia , Abdome/cirurgia , Idoso , Antibacterianos/uso terapêutico , Transplante Ósseo/efeitos adversos , Doença Crônica , Desbridamento/métodos , Feminino , Seguimentos , Retalhos de Tecido Biológico/irrigação sanguínea , Retalhos de Tecido Biológico/transplante , Sobrevivência de Enxerto , Humanos , Vértebras Lombares/patologia , Vértebras Lombares/cirurgia , Masculino , Pessoa de Meia-Idade , Osteomielite/tratamento farmacológico , Osteomielite/patologia , Medição de Risco , Estudos de Amostragem , Índice de Gravidade de Doença , Fusão Vertebral/métodos , Espondilite/tratamento farmacológico , Espondilite/microbiologia , Vértebras Torácicas/patologia , Vértebras Torácicas/cirurgia , Resultado do Tratamento
12.
J Invasive Cardiol ; 21(6): e97-100, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19494419

RESUMO

Anaphylaxis during diagnostic catheterization and coronary intervention is a rare and potentially life-threatening complication. Fortunately, with standard intervention, fatality is rare. We report a case of medically refractory anaphylaxis during a coronary intervention that ultimately responded to percutaneous cardiopulmonary bypass (CPB). The proposed mechanics and use of CPB for shock are discussed.


Assuntos
Anafilaxia/etiologia , Anafilaxia/cirurgia , Angioplastia Coronária com Balão/efeitos adversos , Ponte Cardiopulmonar , Meios de Contraste/efeitos adversos , Síndrome Coronariana Aguda/diagnóstico , Síndrome Coronariana Aguda/terapia , Agonistas Adrenérgicos/uso terapêutico , Idoso , Epinefrina/uso terapêutico , Humanos , Hipotensão/induzido quimicamente , Hipotensão/tratamento farmacológico , Masculino , Resultado do Tratamento
13.
J Surg Res ; 103(2): 134-40, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11922726

RESUMO

The nitrate form of the Group III transitional element gallium (GN) increases expression of specific structural components of the provisional wound matrix (i.e., collagen type I, fibronectin) in human dermal fibroblasts. To evaluate the potential of GN as a therapeutic option in management of cutaneous trauma, GN-treated partial thickness porcine wounds and experimentally "injured" human keratinocyte (NHK) monolayer cultures were compared with mirror image control (i.e., saline-treated) sites. GN suppressed cell proliferation in both models, as determined by reduced Ki-67 reactivity and significant lengthening of keratinocyte cell cycle transit times, while effectively promoting reepithelialization. The primary effect of GN was apparently to promote cell migration, as neither epidermal thickness nor epidermal differentiation was altered as a result of GN exposure in vivo or in vitro. Significantly enhanced epidermal reepithelialization was associated with alterations in expression of several keratinocyte integrin subunits. GN induced a significant increase in alpha5 expression. alpha5beta1 switching is a characteristic of the motile phenotype in the setting of cutaneous injury. Concomitantly, GN treatment also induced a dramatic (70%) decrease in the expression of the alpha3 subunit; alpha3beta1 binds laminin 5 and is associated with hemidesmosome formation and reestablishment of a nonmotile phenotype. Taken together, the GN-induced changes in integrin expression favor acellular migration. While the molecular mechanism of GN action on resident cells of the skin remains to be defined, these data suggest that GN administration which represses MMP activity in the wound and increases matrix synthesis also accelerates NHK motility and, thereby, may be a useful therapeutic agent for wound repair.


Assuntos
Movimento Celular/efeitos dos fármacos , Gálio/farmacologia , Integrinas/análise , Queratinócitos/química , Cicatrização/efeitos dos fármacos , Animais , Técnicas de Cultura de Células , Diferenciação Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Colágeno Tipo I/análise , Células Epidérmicas , Fibronectinas/análise , Citometria de Fluxo , Gálio/uso terapêutico , Humanos , Queratinócitos/efeitos dos fármacos , Antígeno Ki-67/análise , Pele/lesões , Suínos
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