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1.
Ann Thorac Surg ; 97(6): 2193-6, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24882307

RESUMEN

A 44-year-old man with a type A dissection repair 5 years earlier presented with progressive enlargement of the residual arch and thoracic aorta. Flow into the false lumen from the distal aortic suture line was evident on contrast-enhanced computed tomography. Through a redo hemisternotomy, the false lumen was accessed directly. An Amplatzer plug was deployed within the narrowed neck of the false lumen proximal to the enlarged false lumen within descending aorta. Interlocking coils were deployed proximal to the Amplatzer plug, resulting in thrombosis of the false lumen.


Asunto(s)
Aorta Torácica/cirugía , Aneurisma de la Aorta Torácica/cirugía , Disección Aórtica/cirugía , Implantación de Prótesis Vascular/métodos , Embolización Terapéutica , Adulto , Humanos , Masculino
2.
Ann Vasc Surg ; 26(3): 344-52, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22285349

RESUMEN

BACKGROUND: The purpose of this study was to evaluate the 10-year outcome of patients presenting with asymptomatic moderate carotid artery stenosis, and to determine which factors correlate with progression of disease to stroke or revascularization. METHODS: A retrospective review of all new patients presenting with asymptomatic moderate carotid artery stenosis from July 1998 to December 2001 was undertaken. Patients were consecutively identified and included by using duplex ultrasonography to identify moderate carotid disease. Variables were recorded for all patient encounters through June 2010. The primary end point was occurrence of ipsilateral cerebrovascular stroke or revascularization event (SORE). Statin therapy and angiotensin blockade (STAB) were categorized as follows: STAB(0)-medical treatment with neither statin therapy nor angiotensin blockade, STAB(1)-treatment with only one of the two, STAB(2)-treatment with both. An amortized cost model analyzed the cost of SORE-free survival. RESULTS: Over a 42-month period, 468 carotids in 366 patients with an average age of 69.0 ± 8.7 years were evaluated. Over a mean follow-up of 6.6 ± 2.7 years, SORE occurred in 150 (32.1%) carotid arteries. Hyperlipidemia was predictive of SORE (hazard ratio [HR]: 1.543, 95% confidence interval [CI]: 1.053-2.262, P = 0.03). Medical therapies protective against SORE were beta-blockade (HR: 0.612, 95% CI: 0.435-0.861, P < 0.05), STAB(1) (HR: 0.487, 95% CI: 0.336-0.706, P < 0.01), and STAB(2) (HR: 0.149, 95% CI: 0.089-0.248, P < 0.01). At 10 years, SORE-free survival in STAB(2) was 82.7% ± 4.6%, STAB(1) was 56.3% ± 5.0%, and STAB(0) was 29.3% ± 5.4% (P < 0.01). The cost per SORE-free year in STAB(2) was $1,695.40 ± $275.60, STAB(1) was $3,916.80 ± $605.44, and STAB(0) was $4,126.40 ± $427.23 (P < 0.01). CONCLUSION: These data demonstrate the clinical and financial advantage of using both statin therapy and angiotensin pathway blockage in patients with asymptomatic moderate carotid artery stenosis.


Asunto(s)
Bloqueadores del Receptor Tipo 1 de Angiotensina II/uso terapéutico , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Estenosis Carotídea/tratamiento farmacológico , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Anciano , Angioplastia , Bloqueadores del Receptor Tipo 1 de Angiotensina II/efectos adversos , Bloqueadores del Receptor Tipo 1 de Angiotensina II/economía , Inhibidores de la Enzima Convertidora de Angiotensina/efectos adversos , Inhibidores de la Enzima Convertidora de Angiotensina/economía , Enfermedades Asintomáticas , Estenosis Carotídea/complicaciones , Estenosis Carotídea/diagnóstico , Estenosis Carotídea/economía , Estenosis Carotídea/mortalidad , Estenosis Carotídea/cirugía , Análisis Costo-Beneficio , Progresión de la Enfermedad , Supervivencia sin Enfermedad , Costos de los Medicamentos , Quimioterapia Combinada , Endarterectomía Carotidea , Femenino , Costos de la Atención en Salud , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/efectos adversos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/economía , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Modelos Económicos , North Carolina , Estudios Retrospectivos , Índice de Severidad de la Enfermedad , Accidente Cerebrovascular/etiología , Accidente Cerebrovascular/prevención & control , Factores de Tiempo , Resultado del Tratamiento , Ultrasonografía Doppler Dúplex
3.
J Vasc Surg ; 54(6): 1629-36, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21944918

RESUMEN

INTRODUCTION: Thoracic endovascular aortic repair (TEVAR) devices are increasingly being utilized to treat aortic pathologies outside of the original Food & Drug Administration (FDA) approval for nonruptured descending thoracic aorta aneurysms (DTAs). The objective of this study was to evaluate the outcomes of patients undergoing TEVAR, elucidating the role of surgical and pathologic variables on morbidity and mortality. METHODS: National Surgical Quality Improvement Program (NSQIP) data were reviewed for all patients undergoing endovascular thoracic aorta repair from 2005 to 2007. The patients' operative indication and surgical complexity were used to divide them into study and control populations. Comorbid profiles were assessed utilizing a modified Charlson Comorbidity Index (CCI). Thirty-day occurrences of mortality and serious adverse events (SAEs) were used as study endpoints. Univariate and multivariate models were created using demographic and clinical variables to assess for significant differences in endpoints (P ≤ .05). RESULTS: A total of 440 patients undergoing TEVAR were identified. When evaluating patients based on operative indication, the ruptured population had increased mortality and SAE rates compared to the nonruptured DTA population (22.6% vs 6.2%;P < .01 and 35.5% vs 9.1%;P < .01, respectively). Further analysis by surgical complexity revealed increased mortality and SAE rates when comparing the brachiocephalic aortic debranching population to the noncovered left subclavian artery population (23.1% vs 6.5%; P = .02 and 30.8% vs 9.1%; P < .01, respectively). Multivariate analysis demonstrated that operative indication was not a correlate of mortality or SAEs (odds ratio [OR], 0.95; P = .92 and OR, 1.42; P = .39, respectively); however, brachiocephalic aortic debranching exhibited a deleterious effect on mortality (OR, 8.75; P < .01) and SAE rate (OR, 6.67; P = .01). CONCLUSION: The operative indication for a TEVAR procedure was not found to be a predictor of poor patient outcome. Surgical complexity, specifically the need for brachiocephalic aortic debranching and aortoiliac conduit, was shown to influence the occurrence of SAEs in a multivariate model. Comparative data, such as these, illustrate real-world outcomes of patients undergoing TEVAR outside of the original FDA-approved indications. This information is of paramount importance to various stakeholders, including third-party payers, the device industry, regulatory agencies, surgeons, and their patients.


Asunto(s)
Aorta Torácica , Enfermedades de la Aorta/patología , Enfermedades de la Aorta/cirugía , Implantación de Prótesis Vascular , Procedimientos Endovasculares , Anciano , Anciano de 80 o más Años , Enfermedades de la Aorta/mortalidad , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Uso Fuera de lo Indicado , Selección de Paciente , Mejoramiento de la Calidad , Resultado del Tratamiento , Estados Unidos
4.
Surgery ; 150(2): 332-8, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21719058

RESUMEN

BACKGROUND: The objective of this study is to evaluate morbidity and mortality rates in surgical patients at the beginning of the academic year. METHODS: The National Surgical Quality Improvement Program database was utilized to gather data on the 10 most common inpatient operative procedures from 2005-2007. Study end points included mortality, serious adverse events (SAE), and all morbidities. Statistical analysis of outcomes was conducted examining the total population, and then stratified by operation to assess for significant differences in end points (P < .05). RESULTS: A total of 89,473 patients were identified. During the first academic quarter, the mortality rate was no different in the study group than the control group (2.0% vs 2.2%, P = .793). Overall SAE and morbidity rates were similar between populations (11.5% vs 11.4%, P = .697 and 18.3% vs 17.8%, P = .076, respectively). When stratified by operation, "artery bypass graft" (3.7% vs 2.9%, P = .039) and "repair bowel opening" (1.1% vs 0.6%, P = .033) subsets had increases in mortality rate. Multivariate analysis confirmed the deleterious effect of first quarter admission in only the "artery bypass graft" subset (OR = 1.35, CI 1 = .023-1.774). CONCLUSION: By in large, these data refute the "July Phenomenon." Multivariate analysis revealed patient disease to have a greater impact than timing of operation in the "repair bowel opening" subset. The "artery bypass graft" population was affected by timing of operation and the very small effect on mortality (<1%) may reflect new surgery residents being unfamiliar with the management of complex cardiovascular disease.


Asunto(s)
Centros Médicos Académicos/estadística & datos numéricos , Internado y Residencia/estadística & datos numéricos , Procedimientos Quirúrgicos Operativos/estadística & datos numéricos , Adulto , Anciano , Bases de Datos Factuales , Femenino , Mortalidad Hospitalaria , Humanos , Masculino , Persona de Mediana Edad , Evaluación de Resultado en la Atención de Salud , Resultado del Tratamiento
5.
J Vasc Surg ; 52(4): 884-9; discussion 889-90, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20655683

RESUMEN

INTRODUCTION: Traumatic aortic injury (TAI) is a rare yet highly lethal injury associated with blunt force deceleration injury. The adoption of thoracic endovascular aortic repair (TEVAR) has become a safer option than traditional open repair. The purpose of this study is to review a rural trauma center experience with TAI. METHODS: A retrospective analysis was performed, reviewing all patients who presented with TAI between 2000 and 2009. Clinical, anatomical, and procedural variables of all cases were systematically reviewed. Clinical endpoints included mortality, and aortic-related mortality, and hospital length of stay. The study population was stratified by those that underwent surgical repair (SR) and those managed medically (MM). RESULTS: Fifty-six patients presented with blunt TAI; 35 patients (62.5%) were surgically repaired (22 open, 13 TEVAR), while 21 (37.5%) were MM. The only difference in comorbidities was a higher rate of coronary artery disease in MM. Mean hospital arrival time (SR, 188.6 ± 30.3 minutes, MM, 253 ± 65.3 minutes), aortic injury grade (SR, 2.7 ± 0.1; MM, 2.3 ± 0.2), and injury severity score were not significantly different between the groups. Head Abbreviated Injury Score (AIS) was worse in the MM group, while chest AIS was worse in the SR group (P < .05). There were nine (42.9%) deaths in the MM group, while there were only two (5.7%) in the SR group (P < .001). There was no significant difference in aortic-related mortality. Mean follow-up time was not statistically different. CONCLUSION: These data provide a group of stable patients to examine the management of TAI in the endovascular era. The low aortic-related mortality in the MM group demonstrates that there is time for a thorough evaluation in patients sustaining TAI who arrive without hemodynamic instability.


Asunto(s)
Aorta/cirugía , Hospitales Rurales , Centros Traumatológicos , Procedimientos Quirúrgicos Vasculares , Heridas no Penetrantes/terapia , Adulto , Aorta/lesiones , Aorta/fisiopatología , Distribución de Chi-Cuadrado , Femenino , Hemodinámica , Hospitales Rurales/estadística & datos numéricos , Humanos , Estimación de Kaplan-Meier , Tiempo de Internación , Masculino , Persona de Mediana Edad , North Carolina , Sistema de Registros , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Índice de Severidad de la Enfermedad , Factores de Tiempo , Centros Traumatológicos/estadística & datos numéricos , Resultado del Tratamiento , Procedimientos Quirúrgicos Vasculares/efectos adversos , Procedimientos Quirúrgicos Vasculares/mortalidad , Heridas no Penetrantes/diagnóstico , Heridas no Penetrantes/mortalidad , Heridas no Penetrantes/fisiopatología , Heridas no Penetrantes/cirugía
6.
J Vasc Surg ; 52(3): 600-6; discussion 606-7, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20598840

RESUMEN

INTRODUCTION: Within the context of healthcare system reform, the cost efficacy of lower extremity revascularization remains a timely topic. The impact of an individual patient's socioeconomic status represents an under-studied aspect of vascular care, especially with respect to longitudinal costs and outcomes. The purpose of this study is to examine the relationship between socioeconomic status and clinical outcomes as well as inpatient hospital costs. METHODS: A retrospective femoropopliteal revascularization database, which included socioeconomic factors (household income, education level, and payor status), in addition to standard demographic, clinical, anatomical, and procedural variables were analyzed over a 3-year period. Patients were stratified by income level (low income [LI] <200% federal poverty level [$42,400 for a household of 4], and higher income [HI] >200% federal poverty level) and revascularization technique (open vs endovascular) and analyzed for the endpoints of primary assisted patency, amortized cost-per-day of patency, and limb salvage. Data were analyzed with univariate and multivariate techniques. RESULTS: A total of 187 cases were identified with complete data for analysis, 146 in the LI and 41 in the HI cohorts. LI patients differed from HI patients by mean age (66.2 +/- 1.0 vs 61.8 +/- 1.5 years, P = .04), high school graduate rate (51.4% vs 85.4%, P < .001), presence of tissue loss (30.1% vs 14.6%, P = .05), female gender (43.7% vs 22.0%, P = .01) and preoperative statin use (45.8% vs 75.6%, P < .001). There were no differences with respect to other comorbidities including smoking status, presence of diabetes, renal insufficiency, anatomic factors or treatment modality (open vs endovascular). Ninety-seven patients underwent endovascular revascularization. The following outcomes were noted in the endovascular subset of LI and HI patients respectively: primary assisted patency (66% vs 71%, P = NS) and 12-month cost-per-day of patency ($166.30 +/- 77.40 vs $22.45 +/- 12.45, P = .05). Ninety-eight patients underwent open revascularization, with the following outcomes in LI and HI patients respectively: primary assisted patency (78% vs 86%, P = NS) and 12-month cost-per-day of patency ($319.43 +/- 225.44 vs $40.47 +/- 4.63, P = .07). Of the 77 patients with critical limb ischemia, 19 underwent eventual amputation. Multivariate analysis demonstrated that income above 100% of the federal poverty line was protective against limb loss (odds ratio 0.06, 95% confidence interval 0.01-0.51, P < .001). CONCLUSION: Income level correlates with advanced presentation, advanced age, and lack of statin use. Although primary assisted patency rate is not affected by income status, an increased cost-per-day of patency and inferior limb salvage is found in lower income patients.


Asunto(s)
Arteriopatías Oclusivas/economía , Arteriopatías Oclusivas/cirugía , Arteria Femoral/cirugía , Disparidades en Atención de Salud/economía , Costos de Hospital , Evaluación de Procesos y Resultados en Atención de Salud/economía , Arteria Poplítea/cirugía , Factores Socioeconómicos , Procedimientos Quirúrgicos Vasculares/economía , Anciano , Arteriopatías Oclusivas/fisiopatología , Bases de Datos como Asunto , Femenino , Humanos , Renta , Estimación de Kaplan-Meier , Recuperación del Miembro/economía , Masculino , Persona de Mediana Edad , Modelos Económicos , North Carolina , Oportunidad Relativa , Pobreza , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento , Grado de Desobstrucción Vascular
7.
J Vasc Surg ; 51(6): 1390-6, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-20382494

RESUMEN

INTRODUCTION: This study hypothesized that preoperative statin therapy would have a protective effect on patients undergoing elective abdominal aortic aneurysm (AAA) repair and that the risk-reduction effect of these agents would result in a reduction in subsequent total hospital costs. METHODS: All patients who underwent an elective endovascular AAA repair (EVAR) or open AAA repair (OAR) between 2004 and 2007 were retrospectively reviewed. Clinical end points included postoperative days, length of hospital stay, postoperative complications (myocardial infarction, stroke, renal failure, hemorrhage, pneumonia, urinary tract infection, wound infection), and 30-day mortality. The financial end point was total hospital cost associated with the procedure. RESULTS: We identified 401 patients, consisting of 173 EVAR patients (43%) and 228 OAR (57%). Despite a higher Society for Vascular Surgery risk score, the EVAR statin cohort had significantly reduced postoperative days (1.9 +/- 0.2 vs 2.3 +/- 0.3, P < .05) and hospital length of stay (2.3 +/- 0.3 vs 2.8 +/- 0.4, P < .05) compared with the nonstatin EVAR cohort. Postoperative complications (4.4% vs 14.7%, P < .05) and the mortality rate (0.0% vs 5.9%, P < .05) were significantly decreased in the OAR statin cohort compared with the nonstatin OAR cohort and trended to be decreased in the EVAR statin group. Statin therapy translated into a lower total cost per patient of $3,205 for EVAR and $3,792 for OAR (P < .05). CONCLUSION: With respect to both clinical outcome measures and subsequent resource utilization, statin therapy is associated with a beneficial effect in patients undergoing elective AAA repair. These data suggest that preoperative statin therapy should be an integral part of the risk optimization for patients undergoing AAA repair.


Asunto(s)
Aneurisma de la Aorta Abdominal/cirugía , Implantación de Prótesis Vascular , Atención a la Salud/estadística & datos numéricos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Evaluación de Procesos y Resultados en Atención de Salud , Anciano , Aneurisma de la Aorta Abdominal/economía , Aneurisma de la Aorta Abdominal/mortalidad , Implantación de Prótesis Vascular/efectos adversos , Implantación de Prótesis Vascular/economía , Implantación de Prótesis Vascular/mortalidad , Distribución de Chi-Cuadrado , Atención a la Salud/economía , Costos de los Medicamentos , Procedimientos Quirúrgicos Electivos , Femenino , Costos de Hospital , Mortalidad Hospitalaria , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/economía , Tiempo de Internación , Modelos Logísticos , Masculino , Evaluación de Procesos y Resultados en Atención de Salud/economía , Estudios Retrospectivos , Medición de Riesgo , Factores de Riesgo , Factores de Tiempo , Resultado del Tratamiento
8.
Vasc Endovascular Surg ; 41(2): 158-60, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17463210

RESUMEN

Arteritis and mycotic aneurysms have been well described for more than 100 years. The authors report a case of bacterial arteritis that presented with pneumatosis of the aortic wall and that evolved over 1 week into an infected abdominal aortic aneurysm. This case documents the rapid progression from arteritis to mycotic aneurysm, highlighting the need for close radiologic follow-up and aggressive medical and surgical management.


Asunto(s)
Aneurisma Infectado/microbiología , Aneurisma de la Aorta Abdominal/microbiología , Arteritis/complicaciones , Infecciones por Enterobacteriaceae/complicaciones , Aneurisma Infectado/diagnóstico por imagen , Aneurisma Infectado/cirugía , Aneurisma de la Aorta Abdominal/diagnóstico por imagen , Aneurisma de la Aorta Abdominal/cirugía , Arteritis/diagnóstico por imagen , Arteritis/microbiología , Arteritis/cirugía , Citrobacter koseri , Infecciones por Enterobacteriaceae/microbiología , Humanos , Aneurisma Ilíaco/microbiología , Masculino , Persona de Mediana Edad , Tomografía Computarizada por Rayos X , Procedimientos Quirúrgicos Vasculares
9.
Vasc Endovascular Surg ; 41(2): 161-4, 2007.
Artículo en Inglés | MEDLINE | ID: mdl-17463211

RESUMEN

Presented is a patient with an iatrogenic hepatic artery pseudoaneurysm that was treated by endovascular stent grafting. Endovascular stent grafting of a hepatic artery pseudoaneurysm offers a safe and potentially less morbid alternative to an open repair. The report stresses the necessity of careful preoperative evaluation with angiography to determine the feasibility of the procedure. An aggressive approach to treating hepatic artery pseudoaneurysms is advocated because of the poor correlation between size and their tendency to rupture. With an increasing rate of diagnosis of visceral artery aneurysms in elderly, debilitated patients, endovascular repair is anticipated to have an increasing role and should be considered a first-line therapy in anatomically suitable candidates.


Asunto(s)
Aneurisma Falso/cirugía , Implantación de Prótesis Vascular/métodos , Arteria Hepática/cirugía , Stents , Anciano , Aneurisma Falso/diagnóstico por imagen , Implantación de Prótesis Vascular/instrumentación , Femenino , Arteria Hepática/diagnóstico por imagen , Humanos , Arteria Esplénica/diagnóstico por imagen , Arteria Esplénica/cirugía , Tomografía Computarizada por Rayos X
10.
Exp Lung Res ; 30(8): 653-71, 2004 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-15700545

RESUMEN

Bacterial lipopolysaccharide (LPS) causes acute lung injury (ALI) and contributes to inflammation in the acute respiratory distress syndrome (ARDS) and sepsis, making mechanisms of resistance to LPS critically important in clinical settings. The authors postulated that intratracheal administration of a plasmid (pcDNA3. 0-rTNFalpha) encoding rat tumor necrosis factor-alpha (TNF-alpha) would increase resistance of mice to LPS-induced ALI or mortality. They investigated the time course and dose-response for development of LPS-induced ALI in C57/BL6 mice and sought possible protective effects of 100 microg pcDNA3.0-rTNFalpha intratracheally 1, 2, or 3 weeks before LPS challenge. Lung myeloperoxidase (MPO) activity and alveolar lavage fluid (BALF) cell counts increased significantly 48 hours after intraperitoneal (IP) LPS challenges. After pcDNA3.0-rTNFalpha pretreatment, mice challenged with LPS had lower lung/body weight ratios than mice treated with pcDNA3.0; however, other indices of lung injury did not differ. Survival of mice challenged with lethal IP LPS 2 weeks after intratracheal pcDNA3.0-rTNFalpha vector improved significantly, compared to mice pretreated with the control vector, pcDNA3.0. However, pcDNA3.0-pretreated mice tolerated LPS challenge less well than saline-pretreated controls. LPS causes neutrophilic lung injury and mortality, but pcDNA3.0-TNFalpha does not prevent ALI due to LPS. Intratracheal pcDNA3.0-rTNFalpha pretreatment significantly improves survival of mice after LPS challenge, compared to those pretreated with pcDNA3.0.


Asunto(s)
Endotoxinas/toxicidad , Lipopolisacáridos/toxicidad , Pulmón/efectos de los fármacos , Síndrome de Dificultad Respiratoria/tratamiento farmacológico , Factor de Necrosis Tumoral alfa/uso terapéutico , Animales , Líquido del Lavado Bronquioalveolar/citología , Recuento de Células , Citocinas/metabolismo , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Escherichia coli/inmunología , Vectores Genéticos/genética , Inyecciones Intraperitoneales , Intubación Intratraqueal , Lipopolisacáridos/administración & dosificación , Longevidad/efectos de los fármacos , Pulmón/enzimología , Pulmón/patología , Masculino , Ratones , Ratones Endogámicos C57BL , Tamaño de los Órganos/efectos de los fármacos , Peroxidasa/metabolismo , Plásmidos/genética , Síndrome de Dificultad Respiratoria/mortalidad , Síndrome de Dificultad Respiratoria/patología , Tasa de Supervivencia , Factor de Necrosis Tumoral alfa/administración & dosificación , Factor de Necrosis Tumoral alfa/genética
11.
Am J Physiol Lung Cell Mol Physiol ; 286(4): L826-33, 2004 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-14672918

RESUMEN

Lung epithelial cells produce increased reactive oxygen species (ROS) after hypoxia exposure, and they are more susceptible after hypoxia to injury by agents that generate superoxide [O2-; e.g., 2,3-dimethoxy-1,4-naphthoquinone (DMNQ)]. Cellular GSH and MnSOD both decrease in hypoxic lung epithelial cells, altering the redox state. Because ROS participate in signaling pathways involved in cell death or survival, we tested the hypothesis that mitogen-activated protein kinases (MAPK) were involved in a protective response against cellular injury during reoxygenation. Human lung epithelial A549 cells were incubated in hypoxia (<1% O2 for 24 h) and then reoxygenated by return to air. p38mapk and MKK3 phosphorylation both decreased after hypoxia. During reoxygenation, cells were incubated with DMNQ (0-50 microM), a redox cycling quinone that produces O2-. Hypoxia preexposure significantly increased epithelial cell lysis resulting from DMNQ. Addition of the p38mapk inhibitors SB-202190 or SB-203580 markedly increased cytotoxicity, as did the mitogen/extracellular signal-regulated kinase (MEK) 1/2 inhibitor PD-98059 (all 10 microM), suggesting a protective effect of downstream molecules activated by the kinases. Transfection of A549 cells with a dominant active MKK3 plasmid (MKK3[Glu]) partially inhibited cytolysis resulting from DMNQ, whereas the inactive MKK3 plasmid (MKK3[Ala]) had less evident protective effects. Stress-related signaling pathways in epithelial cells are modulated by hypoxia and confer protection from reoxygenation, since hypoxia and chemical inhibition of p38mapk and MEK1/2 similarly increase cytolysis resulting from O2-.


Asunto(s)
Hipoxia/metabolismo , Quinasas de Proteína Quinasa Activadas por Mitógenos/antagonistas & inhibidores , Proteínas Quinasas Activadas por Mitógenos/metabolismo , Estrés Oxidativo/fisiología , Mucosa Respiratoria/metabolismo , Western Blotting , Células Cultivadas , Inhibidores Enzimáticos/farmacología , Humanos , MAP Quinasa Quinasa 1 , MAP Quinasa Quinasa 2 , MAP Quinasa Quinasa 3 , Sistema de Señalización de MAP Quinasas/fisiología , Quinasas de Proteína Quinasa Activadas por Mitógenos/genética , Quinasas de Proteína Quinasa Activadas por Mitógenos/metabolismo , Proteínas Quinasas Activadas por Mitógenos/genética , Fosforilación , Proteínas Tirosina Quinasas/antagonistas & inhibidores , Proteínas Tirosina Quinasas/genética , Proteínas Tirosina Quinasas/metabolismo , Mucosa Respiratoria/citología , Ribonucleasas , Transfección , Proteínas Quinasas p38 Activadas por Mitógenos
13.
Am J Physiol Lung Cell Mol Physiol ; 285(1): L189-98, 2003 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12665464

RESUMEN

Both NADH dehydrogenase (complex I) and aconitase are inactivated partially in vitro by superoxide (O2-.) and other oxidants that cause loss of iron from enzyme cubane (4Fe-4S) centers. We tested whether hypoxia-reoxygenation (H-R) by itself would decrease lung epithelial cell NADH dehydrogenase, aconitase, and succinate dehydrogenase (SDH) activities and whether transfection with adenoviral vectors expressing MnSOD (Ad.MnSOD) would inhibit oxidative enzyme inactivation and thus confirm a mechanism involving O2-. Human lung carcinoma cells with alveolar epithelial cell characteristics (A549 cells) were exposed to <1% O2-5% CO2 (hypoxia) for 24 h followed by air-5% CO2 for 24 h (reoxygenation). NADH dehydrogenase activity was assayed in submitochondrial particles; aconitase and SDH activities were measured in cell lysates. H-R significantly decreased NADH dehydrogenase, aconitase, and SDH activities. Ad.MnSOD increased mitochondrial MnSOD substantially and prevented the inhibitory effects of H-R on enzyme activities. Addition of alpha-ketoglutarate plus aspartate, but not succinate, to medium prevented cytotoxicity due to 2,3-dimethoxy-1,4-naphthoquinone. After hypoxia, cells displayed significantly increased dihydrorhodamine fluorescence, indicating increased mitochondrial oxidant production. Inhibition of NADH dehydrogenase, aconitase, and SDH activities during reoxygenation are due to excess O2-. produced in mitochondria, because enzyme inactivation can be prevented by overexpression of MnSOD.


Asunto(s)
Mitocondrias/enzimología , Daño por Reperfusión/metabolismo , Mucosa Respiratoria/enzimología , Superóxido Dismutasa/metabolismo , Aconitato Hidratasa/metabolismo , Adenocarcinoma Papilar , Adenoviridae/genética , Ácido Aspártico/farmacología , Ditiotreitol/farmacología , Complejo I de Transporte de Electrón , Activación Enzimática/efectos de los fármacos , Activación Enzimática/efectos de la radiación , Células Epiteliales/citología , Células Epiteliales/enzimología , Regulación Enzimológica de la Expresión Génica , Vectores Genéticos , Humanos , Ácidos Cetoglutáricos/farmacología , Luz , NADH Deshidrogenasa/metabolismo , NADH NADPH Oxidorreductasas/metabolismo , Estrés Oxidativo/efectos de los fármacos , Estrés Oxidativo/fisiología , Estrés Oxidativo/efectos de la radiación , Oxígeno/farmacología , Protectores contra Radiación/farmacología , Especies Reactivas de Oxígeno/metabolismo , Mucosa Respiratoria/citología , Rodaminas , Succinato Deshidrogenasa/metabolismo , Ácido Succínico/farmacología , Superóxido Dismutasa/genética , Transfección , Células Tumorales Cultivadas
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