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1.
World J Surg ; 44(11): 3770-3777, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32572525

RESUMEN

BACKGROUND: Prior to thyroidectomy for hyperthyroidism, it is recommended that patients are managed with antithyroid drugs (ATDs) and rendered euthyroid to decrease the risk of thyroid storm. However, not all patients tolerate ATD and the risk of thyroid storm during thyroidectomy in these patients is unclear. Therefore, the aim of this study was to compare the management and outcomes of hyperthyroid patients that were on ATDs prior to surgery to those who were not. STUDY DESIGN: A prospectively maintained, single-institution database was queried for all hyperthyroid patients who were initially treated with ATDs and underwent thyroidectomy from January 1, 2012, to June 18, 2018. Patients were divided into two groups: (1) those on ATDs at surgery (ATD group) and (2) those who could not tolerate and stopped ATDs prior to surgery (no-ATD group). Demographic and clinical data were collected. Primary outcomes were readmissions/emergency department visits and postoperative complications within 30 days of thyroidectomy. RESULTS: Of the 248 patients, 231 were in the ATD group and 17 (7%) were in the no-ATD group. There were no mortalities or thyroid storm events in either group. There was no difference in Clavien-Dindo Grade 2 or 3 complications between the two groups. There were no ED visits or 30-day readmissions in the no-ATD group compared to 17 (7%) events in the ATD group (p = 1.0). CONCLUSION: While it is preferable to render patients euthyroid prior to thyroidectomy for hyperthyroidism, results of this study suggest that when patients cannot tolerate ATDs, it is possible to perform thyroidectomy without increased risk of thyroid storm or intra- and postoperative complications.


Asunto(s)
Antitiroideos/efectos adversos , Enfermedad de Graves/cirugía , Hipertiroidismo/cirugía , Atención Perioperativa , Tiroidectomía/efectos adversos , Adulto , Antitiroideos/uso terapéutico , Femenino , Enfermedad de Graves/tratamiento farmacológico , Humanos , Hipertiroidismo/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/epidemiología , Estudios Prospectivos , Resultado del Tratamiento
2.
J Pediatr Surg ; 55(7): 1265-1269, 2020 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31892477

RESUMEN

BACKGROUND: Hypocalcemia occurs frequently after a total thyroidectomy in pediatric patients. Four hour postoperative PTH monitoring predicts the need for calcium supplementation in the adult thyroidectomy population. We evaluated the role of the 4 h postoperative PTH level in determining the need for calcium supplementation after thyroidectomy in the pediatric population. METHODS: This is a retrospective review of children undergoing total thyroidectomy by a single pediatric surgeon from July 2011 through July 2018. Intact PTH obtained four hours postoperatively determined the need for calcium supplementation for patients beginning in November 2014 onward. Serum total calcium levels were monitored concurrently with serum intact PTH levels. Serum calcium levels were followed in our Multispecialty Pediatric Endocrine Surgery clinic within the month following thyroidectomy. RESULTS: From July 2011 through July 2018, there were a total of 56 total thyroidectomies at our institution. Prior to November 2014, all pediatric total thyroidectomies received calcium supplementation per our institutional protocol. Based on ionized calcium levels, 26.3% (5/19) of children developed hypocalcemia. From November 2014 to July 2018, 37 pediatric patients required total thyroidectomies. 29.7% (11/37) had low 4-h postoperative PTH levels. 72.7% (8/11) patients with low 4-h postoperative PTH levels had corresponding postoperative day 1 total calcium levels less than 8.5 or ionized calcium levels less than 1.12, and five children (45.5%) developed symptomatic hypocalcemia. 70% (26/37) of children had normal 4-h postop PTH levels, with only 5 (19%) ever developing hypocalcemia. No patients with a normal postop PTH level developed symptomatic hypocalcemia or required IV calcium repletion. A single 4-h postoperative PTH <10 pg/dl for identifying hypocalcemia has a sensitivity of 81% and specificity of 91%, with AUC 0.81. CONCLUSION: The 4-h postoperative serum PTH level can help determine the need for calcium supplementation in pediatric patients undergoing total thyroidectomy, thereby reducing unnecessary calcium supplementation and serial lab draws to monitor for postoperative hypocalcemia. LEVEL OF EVIDENCE: Level II.


Asunto(s)
Hipocalcemia/diagnóstico , Hormona Paratiroidea/sangre , Complicaciones Posoperatorias/diagnóstico , Tiroidectomía , Adolescente , Biomarcadores/sangre , Calcio/uso terapéutico , Hormonas y Agentes Reguladores de Calcio/uso terapéutico , Niño , Preescolar , Toma de Decisiones Clínicas/métodos , Femenino , Estudios de Seguimiento , Humanos , Hipocalcemia/sangre , Hipocalcemia/tratamiento farmacológico , Hipocalcemia/etiología , Lactante , Masculino , Complicaciones Posoperatorias/sangre , Complicaciones Posoperatorias/tratamiento farmacológico , Complicaciones Posoperatorias/etiología , Estudios Retrospectivos
3.
Surg Clin North Am ; 99(4): 747-758, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31255204

RESUMEN

Without the overt clinical signs and symptoms associated with Cushing's syndrome, the diagnosis of subclinical Cushing's syndrome (SCS) is primarily based on biochemical evaluation. Despite being labeled as "subclinical," SCS is associated with significant morbidity that can be improved with adrenalectomy. Minimally invasive adrenalectomy is associated with low morbidity in the hands of experienced adrenal surgeons and is recommended as the treatment of choice for SCS patients with SCS-associated comorbidities.


Asunto(s)
Adrenalectomía/métodos , Síndrome de Cushing/cirugía , Toma de Decisiones , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Síndrome de Cushing/diagnóstico , Síndrome de Cushing/metabolismo , Humanos , Hidrocortisona/metabolismo
4.
J Surg Res ; 242: 318-322, 2019 10.
Artículo en Inglés | MEDLINE | ID: mdl-31129240

RESUMEN

BACKGROUND: Laparoscopic intraoperative cholangiogram (IOC) with common bile duct exploration (CBDE) and endoscopic retrograde cholangiopancreatography (ERCP) are two therapeutic techniques for choledocholithiasis. The preferred technique is unclear. MATERIALS AND METHODS: We identified subjects who underwent laparoscopic cholecystectomy (LC) and IOC/CBDE or ERCP from July 1, 2006, to December 31, 2016. We retrospectively reviewed 81 patients (≤ 18 y) who received these interventions for suspected choledocholithiasis. Main outcomes analyzed were success of intervention and complications. RESULTS: Of the 81 patients, 21 ERCPs and three endoscopic ultrasounds (EUSs) were performed before LC. Eighteen of 21 (85.7%) patients had stones or sludge cleared by ERCP, whereas 3 (14.3%) had normal common bile ducts without evidence of stones. Five of 24 (20.8%) had significant post-ERCP complications. Seven of 24 (29.2%) had more than one admission. Sixty of 81 patients underwent LC with IOC ± CBDE. Twenty one of 60 (36.2%) were found to have abnormal IOC. Eight of 15 (53.3%) attempted laparoscopic CBDE were successful. Eleven of 21 (52.4%) patients with abnormal IOC had post-LC ERCP (10) and EUS (1). Patients admitted to the Pediatric Surgery service were more likely to undergo LC first than ERCP/EUS (OR 3.46, 95% CI 1.26 to 9.45, P = 0.016). Patients undergoing LC first had a shorter length of stay (mean LOS 5.13 d versus 4.07, median 5.0 versus 3.0 d, P-value < 0.05). CONCLUSIONS: Successful and safe laparoscopic treatment of choledocholithiasis is possible in the pediatric patient. A laparoscopic-first approach to suspected choledocholithiasis may reduce the number of procedures needed in this patient population.


Asunto(s)
Colangiografía/métodos , Colangiopancreatografia Retrógrada Endoscópica/efectos adversos , Colecistectomía Laparoscópica/métodos , Coledocolitiasis/cirugía , Complicaciones Posoperatorias/prevención & control , Adolescente , Coledocolitiasis/diagnóstico por imagen , Conducto Colédoco/diagnóstico por imagen , Conducto Colédoco/cirugía , Estudios de Factibilidad , Femenino , Humanos , Tiempo de Internación/estadística & datos numéricos , Masculino , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Estudios Retrospectivos , Resultado del Tratamiento
5.
J Pediatr Surg ; 53(4): 629-634, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29173775

RESUMEN

PURPOSE: For the last seven years, our institution has repaired infants with CDH that require ECMO early after cannulation. Prior to that, we attempted to decannulate before repair, but repaired on ECMO if we were unable to wean after two weeks. This study compares those strategies. METHODS: From 2002 to 2016, 65 infants with CDH required ECMO. 67.7% were repaired on ECMO, and 27.7% were repaired after decannulation. Data were compared between patients repaired ≤5days after cannulation ("early protocol", n=30) and >5days after cannulation or after de-cannulation ("late protocol", n=35). We used Cox regression to assess differences in outcomes between groups. RESULTS: Survival for the early and late protocol groups was 43.3% and 68.8%, respectively (p=0.0485). For patients that were successfully decannulated before repair, survival was 94.4%. Moreover, the early repair protocol was associated with prolongation of ECMO (16.8±7.4 vs. 12.6±6.8days, p=0.0216). After multivariate regression, the early repair protocol was an independent predictor of both mortality (HR=3.48, 95% CI=1.28-9.45, p=0.015) and days on ECMO (IRR=1.39, 95% CI=1.07-1.79, p=0.012). All bleeding occurred in patients repaired on ECMO (29.5%, 13/44). CONCLUSIONS: Our data suggest that protocolized CDH repair early after ECMO cannulation may be associated with increased mortality and prolongation of ECMO. However, early repair is not necessarily harmful for those patients who would otherwise be unable to wean from ECMO before repair. Further work is needed to better move towards individualized patient care. TYPE OF STUDY: Treatment Study. LEVEL OF EVIDENCE: Level III.


Asunto(s)
Oxigenación por Membrana Extracorpórea/métodos , Hernias Diafragmáticas Congénitas/cirugía , Herniorrafia/métodos , Femenino , Humanos , Lactante , Recién Nacido , Masculino , Estudios Retrospectivos , Resultado del Tratamiento
6.
J Laparoendosc Adv Surg Tech A ; 28(2): 223-228, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29261090

RESUMEN

INTRODUCTION: Interestingly, the pediatric and adult surgeons perform vastly different operations in similar patient populations. Little is known about long-term recurrence and quality of life (QOL) in adolescents and young adults undergoing inguinal hernia repair. We evaluated long-term patient-centered outcomes in this population to determine the optimal operative approach. METHODS: The medical records of patients 12-25 years old at the time of a primary inguinal hernia repair at our institution from 2000 to 2016 were retrospectively reviewed. Patients then completed a phone survey of their postoperative courses and QOL. Outcomes of high ligation performed by pediatric surgeons were compared to those of mesh repairs by adult general surgeons. The primary outcome was recurrence. Secondary outcomes included time to recurrence, postoperative complications, and patient-centered outcomes. A Cox regression analysis was used to determine associations for recurrence. RESULTS: Of 213 patients identified, 143 (67.1%) were repaired by adult surgeons and 70 (32.9%) repaired by pediatric surgeons. Overall recurrence rate for the entire cohort was 5.7% with a median time to recurrence of 3.5 years (interquartile range 120-2155 days). High ligation and mesh repairs had similar rates of recurrence (6.3 versus 5.8, P = .57) and postoperative complications (17% versus 16%, P = .45). 101/213 (47%) patients completed the phone survey. Of those surveyed, 20% reported postoperative pain, 10% had residual numbness and tingling, and 10% of patients complained of intermittent bulging. Overall, a survey comparison showed no differences among subgroups. CONCLUSIONS: In adolescents and young adults, the long-term recurrence rate after inguinal hernia repair is ∼6% with time to recurrence approaching 4 years. Outcomes of high ligation and mesh repair are similar, highlighting the need for individualized approaches for this unique population.


Asunto(s)
Hernia Inguinal/cirugía , Herniorrafia/métodos , Ligadura/métodos , Mallas Quirúrgicas/efectos adversos , Adolescente , Adulto , Niño , Femenino , Herniorrafia/efectos adversos , Humanos , Ligadura/efectos adversos , Masculino , Evaluación del Resultado de la Atención al Paciente , Complicaciones Posoperatorias/epidemiología , Calidad de Vida , Recurrencia , Estudios Retrospectivos , Resultado del Tratamiento , Adulto Joven
7.
Pediatr Nephrol ; 33(3): 503-510, 2018 03.
Artículo en Inglés | MEDLINE | ID: mdl-28983789

RESUMEN

BACKGROUND: Morbidity and mortality with necrotizing enterocolitis (NEC) remains a significant challenge. Acute kidney injury (AKI) has been shown to worsen survival in critically ill neonates. To our knowledge, this study is the first to evaluate the prevalence of AKI and its impact on outcomes in neonatal NEC. METHODS: We carried out a single-center retrospective chart review of all neonates treated for NEC between 2003 and 2015 (N = 181). AKI is defined as a rise in serum creatinine (SCr) from a previous trough according to neonatal modified KDIGO criteria (stage 1 = SCr rise 0.3 mg/dL or SCr 150 < 200%, stage 2 = SCr rise 200 < 300%, stage 3 = SCr rise ≥300%, SCr 2.5 mg/dL or dialysis). Primary outcome was in-hospital mortality and secondary outcomes were hospital length of stay (LOS) and need for and type of surgery. RESULTS: Acute kidney injury occurred in 98 neonates (54%), with 39 stage 1 (22%), 31 stage 2 (18%), and 28 stage 3 (16%), including 5 requiring dialysis. Non-AKI and AKI groups were not statistically different in age, weight, Bell's NEC criteria, and medication exposure (vasopressors, vancomycin, gentamicin, or diuretic). Neonates with AKI had higher mortality (44% vs 25.6%, p = 0.008) and a higher chance of death (HR 2.4, CI 1.2-4.8, p = 0.009), but the effect on LOS on survivors did not reach statistical significance (79 days, interquartile range [IQR] 30-104 vs 54 days, IQR 30-92, p = 0.09). Overall, 48 (27.9%) patients required surgical intervention. CONCLUSIONS: This study shows that AKI not only occurs in over half of patients with NEC, but that it is also associated with more than a two-fold higher mortality, highlighting the importance of early recognition and potentially early intervention for AKI.


Asunto(s)
Lesión Renal Aguda/epidemiología , Enterocolitis Necrotizante/complicaciones , Lesión Renal Aguda/complicaciones , Lesión Renal Aguda/mortalidad , Bases de Datos Factuales , Enterocolitis Necrotizante/mortalidad , Femenino , Mortalidad Hospitalaria , Humanos , Lactante , Mortalidad Infantil , Recién Nacido , Tiempo de Internación/estadística & datos numéricos , Masculino , Michigan/epidemiología , Prevalencia , Estudios Retrospectivos , Factores de Riesgo
8.
Pediatr Surg Int ; 33(9): 981-987, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28685301

RESUMEN

PURPOSE: Guidelines for diagnosis and treatment of adrenal insufficiency (AI) in newborns with congenital diaphragmatic hernia (CDH) are poorly defined. METHODS: From 2002 to 2016, 155 infants were treated for CDH at our institution. Patients with shock refractory to vasopressors (clinically diagnosed AI) were treated with hydrocortisone (HC). When available, random cortisol levels <10 µg/dL were considered low. Outcomes were compared between groups. RESULTS: Hydrocortisone was used to treat AI in 34% (53/155) of patients. That subset of patients was demonstrably sicker, and mortality was expectedly higher for those treated with HC (37.7 vs. 17.6%, p = 0.0098). Of the subset of patients with random cortisol levels measured before initiation of HC, 67.7% (21/31) had low cortisol levels. No significant differences were seen in survival between the high and low groups, but mortality trended higher in patients with high cortisol levels that received HC. After multivariate analysis, duration of HC stress dose administration was associated with increased risk of mortality (OR 1.11, 95% CI 1.02-1.2, p = 0.021), and total duration of HC treatment was associated with increased risk of sepsis (OR 1.04, 95% CI 1.005-1.075, p = 0.026). CONCLUSION: AI is prevalent amongst patients with CDH, but prolonged treatment with HC may increase risk of mortality and sepsis.


Asunto(s)
Insuficiencia Suprarrenal/tratamiento farmacológico , Antiinflamatorios/uso terapéutico , Hernias Diafragmáticas Congénitas/complicaciones , Hidrocortisona/uso terapéutico , Insuficiencia Suprarrenal/complicaciones , Insuficiencia Suprarrenal/mortalidad , Femenino , Humanos , Hidrocortisona/sangre , Lactante , Recién Nacido , Masculino , Estudios Retrospectivos , Sepsis/etiología
10.
J Neurotrauma ; 27(3): 647-51, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19929186

RESUMEN

Evidence suggests that the gamma-aminobutyric acid (GABA)ergic system may be involved in cognitive dysfunction following traumatic brain injury (TBI). We investigated the effect of flumazenil treatment, a benzodiazepine antagonist approved by the U.S. Food and Drug Administration, on learning and memory in the immature rat following experimental brain injury. Post-natal day 17 rats were injured using controlled cortical impact. Systemic treatment with flumazenil at 1, 5, and 10 mg/kg was initiated on post-injury day 1 and administered for 13 days via daily intraperitoneal injections. Morris water maze (MWM) testing was used to measure latency to find a submerged platform and the results from experimental and control animals were compared. We demonstrated a significant dose-dependent improvement in MWM performance in drug-treated animals. This is the first study demonstrating the efficacy of flumazenil in reducing post-TBI cognitive deficits and we propose that these effects may be related to modulation of the GABA(A) receptor.


Asunto(s)
Química Encefálica/efectos de los fármacos , Lesiones Encefálicas/tratamiento farmacológico , Encéfalo/efectos de los fármacos , Trastornos del Conocimiento/tratamiento farmacológico , Flumazenil/farmacología , Ácido gamma-Aminobutírico/metabolismo , Animales , Encéfalo/patología , Encéfalo/fisiopatología , Química Encefálica/fisiología , Lesiones Encefálicas/complicaciones , Lesiones Encefálicas/fisiopatología , Trastornos del Conocimiento/etiología , Trastornos del Conocimiento/fisiopatología , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Flumazenil/uso terapéutico , Moduladores del GABA/farmacología , Moduladores del GABA/uso terapéutico , Inyecciones Intraperitoneales , Masculino , Aprendizaje por Laberinto/efectos de los fármacos , Aprendizaje por Laberinto/fisiología , Nootrópicos/farmacología , Nootrópicos/uso terapéutico , Ratas , Ratas Sprague-Dawley , Tiempo de Reacción/efectos de los fármacos , Tiempo de Reacción/fisiología , Receptores de GABA-A/efectos de los fármacos , Receptores de GABA-A/metabolismo , Resultado del Tratamiento
11.
J Inflamm (Lond) ; 5: 22, 2008 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-19055838

RESUMEN

BACKGROUND: Evaluate the potential role of p38 inhibitors for the treatment of osteoarthritis using an animal model of joint degeneration (iodoacetate-induced arthritis) and a pain model (Hargraeves assay). METHODS: P38 kinase activity was evaluated in a kinase assay by measuring the amount of phosphorylated substrate ATF2 using a phosphoATF2 (Thr71) specific primary antibody and an alkaline phosphate coupled secondary antibody and measuring the OD at 405 nm. TNFalpha and IL-1beta secretion from LPS stimulated THP-1 monocytic cells and human peripheral blood mononuclear cells were measured by ELISA. Rats treated with vehicle or p38 inhibitor were injected intra-articularly in one knee with iodoacetate and damage to the tibial plateau was assessed from digitized images captured using an image analyzer. The effect of p38 inhibitors on hyperalgesia was evaluated in rats given an intraplantar injection of carrageenan and 4 h later the paw withdrawal time to a radiant heat source was measured. RESULTS: SB-203580 and VX-745 are both potent inhibitors of p38 with IC50s of 136 +/- 64 nM and 35 +/- 14 nM (mean +/- S.D.), respectively. Similarly, SB-203580 and VX-745 potently inhibited TNF release from LPS stimulated human THP-1 cells with IC50s of 72 +/- 15 nM; and 29 +/- 14 nM (mean +/- S.D.) respectively. TNF release from LPS stimulated human peripheral blood mononuclear cells was inhibited with IC50s 16 +/- 6 nM and 14 +/- 8 nM, (mean +/- S.D.) for SB-203580 and VX-745 and IL-1 was inhibited with IC50s of 20 +/- 8 nM and 15 +/- 4 nM (mean +/- S.D.), respectively. SB-203580 and VX-745 administered orally at a dose of 50 mg/kg resulted in the significant (p < 0.05) inhibition of joint degeneration in the rat iodoacetate model of 45% and 31%, respectively. SB-203580 demonstrated a dose related inhibition of joint degeneration of 30, 25, 12 and 8% at 50, 25, 10 and 5 mg/kg p.o. b.i.d. in the rat iodoacetate model. Similarly, both p38 inhibitors significantly (p < 0.05) attenuated the pain response (paw withdrawal time) in the Hargraeves hyperalgesia assay when administered orally at 30, 10 and 3 mg/kg. CONCLUSION: SB203580 and VX-745 demonstrated attenuation of both cartilage degeneration and pain in animal models and suggest that p38 inhibitors may be a useful approach for the treatment of osteoarthritis.

12.
Bioorg Med Chem Lett ; 16(23): 5973-7, 2006 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-16997556
14.
Bioorg Med Chem Lett ; 16(16): 4360-5, 2006 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-16750367

RESUMEN

A series of C-2, C-8, and N-9 trisubstituted purine based inhibitors of TNF-alpha production are described. The most potent analogs showed low nanomolar activity against LPS-induced TNF-alpha production in a THP-1 cell based assay. The SAR of the series was optimized with the aid of X-ray co-crystal structures of these inhibitors bound with mutated p38 (mp38).


Asunto(s)
Purinas/química , Factor de Necrosis Tumoral alfa/química , Línea Celular , Química Farmacéutica , Cristalografía por Rayos X , Diseño de Fármacos , Humanos , Lipopolisacáridos/química , Modelos Químicos , Modelos Moleculares , Proteínas Quinasas p38 Activadas por Mitógenos/química , Proteínas Quinasas p38 Activadas por Mitógenos/genética
15.
Bioorg Med Chem Lett ; 16(14): 3646-50, 2006 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-16682201

RESUMEN

A new class of lymphocyte specific tyrosine kinase (lck) inhibitors based on an N-4,6-pyrimidine-N-alkyl-N'-phenyl urea scaffold is described. Many of these compounds showed low-nanomolar inhibition of lck kinase activity as well as IL-2 synthesis from Jurkat cells. One of these analogs, 7i, was shown to be orally efficacious by in vivo testing in a rat adjuvant-induced arthritis study.


Asunto(s)
Inhibidores Enzimáticos/síntesis química , Proteína Tirosina Quinasa p56(lck) Específica de Linfocito/antagonistas & inhibidores , Compuestos de Fenilurea/síntesis química , Pirimidinas/química , Administración Oral , Animales , Artritis Experimental/tratamiento farmacológico , Artritis Experimental/patología , Inhibidores Enzimáticos/farmacología , Inhibidores Enzimáticos/uso terapéutico , Humanos , Interleucina-2/biosíntesis , Células Jurkat , Estructura Molecular , Compuestos de Fenilurea/farmacología , Ratas
16.
Ann Neurol ; 59(6): 929-38, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16673393

RESUMEN

OBJECTIVE: Early reperfusion after an ischemic stroke can cause blood-brain barrier injury with subsequent cerebral edema and devastating brain hemorrhage. These complications of early reperfusion, which result from excess production of reactive oxygen species, significantly limit the benefits of stroke therapies. In this article, we use a novel animal model that facilitates identification of specific components of the reperfusion injury process, including vascular injury and secondary brain damage, and allows assessment of therapeutic interventions. METHODS: Knock-out (KO) mice containing 50% manganese-superoxide dismutase activity (SOD2-KO) and transgenic mice overexpressing SOD2 undergo transient focal ischemia and reperfusion followed by assessment of infarct, edema, hemorrhage rates, metalloproteinase activation, and microvascular injury. RESULTS: SOD2-KO mice demonstrate delayed (>24h) blood-brain barrier breakdown associated with activation of matrix metalloproteinases, inflammation, and high brain hemorrhage rates. These adverse consequences are absent in wild-type littermates and minocycline-treated SOD2-KO animals. Increased hemorrhage rates also are absent in SOD2 overexpressors, which have reduced vascular endothelial cell death. Finally, we show that the tight junction membrane protein, occludin, is an early and specific target in oxidative stress-induced microvascular injury. INTERPRETATION: This model is ideal for studying ischemia/reperfusion-induced vascular injury and secondary brain hemorrhage and offers a unique opportunity to evaluate antioxidant-based neurovascular protective strategies as potential adjunct treatments to currently approved stroke therapies such as thrombolysis and endovascular clot retrieval.


Asunto(s)
Isquemia Encefálica/fisiopatología , Hemorragia Cerebral/fisiopatología , Modelos Animales de Enfermedad , Daño por Reperfusión/fisiopatología , Superóxido Dismutasa/metabolismo , Animales , Barrera Hematoencefálica/patología , Western Blotting , Encéfalo/irrigación sanguínea , Encéfalo/patología , Encéfalo/fisiopatología , Isquemia Encefálica/complicaciones , Isquemia Encefálica/patología , Hemorragia Cerebral/etiología , Hemorragia Cerebral/patología , Inhibidores Enzimáticos/farmacología , Etiquetado Corte-Fin in Situ , Metaloproteinasa 9 de la Matriz/efectos de los fármacos , Metaloproteinasa 9 de la Matriz/metabolismo , Ratones , Ratones Noqueados , Ratones Transgénicos , Minociclina/farmacología , Estrés Oxidativo/efectos de los fármacos , Estrés Oxidativo/fisiología , Daño por Reperfusión/complicaciones , Daño por Reperfusión/patología , Superóxido Dismutasa/genética
17.
Bioorg Med Chem Lett ; 16(13): 3514-8, 2006 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-16632350

RESUMEN

A new class of tumor necrosis factor alpha (TNF-alpha) synthesis inhibitors based on a N-2,4-pyrimidine-N-phenyl-N'-alkyl urea scaffold is described. Many of these compounds showed low-nanomolar activity against lipopolysaccharide stimulated TNF-alpha production. Two analogs were tested in an in vivo rat iodoacetate model of osteoarthritis and shown to be orally efficacious. X-ray co-crystallization studies with mutated p38alpha showed that these trisubstituted ureas interact with the ATP-binding pocket in a pseudo-bicyclic conformation brought about by the presence of an intramolecular hydrogen bonding interaction.


Asunto(s)
Artritis Experimental/tratamiento farmacológico , Osteoartritis/tratamiento farmacológico , Compuestos de Fenilurea/química , Compuestos de Fenilurea/farmacología , Pirimidinas/química , Pirimidinas/farmacología , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Adenosina Trifosfato/química , Animales , Antiinflamatorios no Esteroideos/química , Antiinflamatorios no Esteroideos/clasificación , Antiinflamatorios no Esteroideos/farmacología , Artritis Experimental/inducido químicamente , Sitios de Unión , Cristalografía por Rayos X , Modelos Animales de Enfermedad , Evaluación Preclínica de Medicamentos , Enlace de Hidrógeno , Yodoacetatos , Lipopolisacáridos/antagonistas & inhibidores , Lipopolisacáridos/farmacología , Modelos Moleculares , Estructura Molecular , Osteoartritis/inducido químicamente , Compuestos de Fenilurea/clasificación , Pirimidinas/clasificación , Ratas , Estereoisomerismo , Relación Estructura-Actividad , Factor de Necrosis Tumoral alfa/biosíntesis
18.
Bioorg Med Chem Lett ; 16(13): 3510-3, 2006 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-16632356

RESUMEN

A new class of tumor necrosis factor alpha (TNF-alpha) synthesis inhibitors based on an N-2,4-pyrimidine-N-phenyl-N'-phenyl urea scaffold is described. Many of these compounds showed low-nanomolar activity against lipopolysaccharide stimulated TNF-alpha production. X-ray co-crystallization studies with mutated p38alpha showed that these trisubstituted ureas interact with the ATP-binding pocket in a pseudo-bicyclic conformation brought about by the presence of an intramolecular hydrogen bonding interaction.


Asunto(s)
Compuestos de Fenilurea/química , Compuestos de Fenilurea/farmacología , Pirimidinas/química , Pirimidinas/farmacología , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Adenosina Trifosfato/química , Sitios de Unión , Cristalografía por Rayos X , Enlace de Hidrógeno , Lipopolisacáridos/antagonistas & inhibidores , Lipopolisacáridos/farmacología , Modelos Moleculares , Estructura Molecular , Compuestos de Fenilurea/clasificación , Pirimidinas/clasificación , Estereoisomerismo , Relación Estructura-Actividad , Factor de Necrosis Tumoral alfa/biosíntesis
19.
Mol Neurobiol ; 31(1-3): 105-16, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15953815

RESUMEN

It has been demonstrated by numerous studies that apoptotic cell death pathways are implicated in ischemic cerebral injury in ischemia models in vivo. Experimental ischemia and reperfusion models, such as transient focal/global ischemia in rodents, have been thoroughly studied and the numerous reports suggest the involvement of cell survival/death signaling pathways in the pathogenesis of apoptotic cell death in ischemic lesions. In these models, reoxygenation during reperfusion provides oxygen as a substrate for numerous enzymatic oxidation reactions and for mitochondrial oxidative phosphorylation to produce adenosine triphosphate. Oxygen radicals, the products of these biochemical and physiological reactions, are known to damage cellular lipids, proteins, and nucleic acids and to initiate cell signaling pathways after cerebral ischemia. Genetic manipulation of intrinsic antioxidants and factors in the signaling pathways has provided substantial understanding of the mechanisms involved in cell death/survival signaling pathways and the role of oxygen radicals in ischemic cerebral injury. Future studies of these pathways could provide novel therapeutic strategies in clinical stroke.


Asunto(s)
Isquemia Encefálica/metabolismo , Neuronas/metabolismo , Estrés Oxidativo/fisiología , Transducción de Señal/fisiología , Animales , Muerte Celular/fisiología , Supervivencia Celular/fisiología , Humanos
20.
Neurobiol Dis ; 20(2): 491-9, 2005 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-15896972

RESUMEN

The serine-threonine kinase Akt is a cell survival signaling pathway that inactivates the proapoptotic BCL-2 family protein Bad and promotes cell survival in cerebral ischemia. Involvement of the Akt/Bad signaling pathway after spinal cord injury (SCI) is, however, uncertain. Our results showed that phospho-Akt (serine-473) and phospho-Bad (serine-136) were significantly upregulated at 1 day after SCI. In addition, phospho-Akt and phospho-Bad were colocalized in motor neurons that survived SCI and inhibition of PI3-K reduced expression of phospho-Akt and phospho-Bad. Dimerization of Bad with 14-3-3 in the cytosol was increased whereas Bad/Bcl-XL binding in the mitochondria was decreased after SCI. We further found that reduced oxidative stress by SOD1 overexpression in rats enhanced the expression of phospho-Akt, phospho-Bad, Bad/14-3-3 binding and reduced Bad/Bcl-XL binding after SCI, as compared to wild-type rats. We conclude that oxidative stress may play a role in modulating Akt/Bad signaling and subsequent motor neuron survival after SCI.


Asunto(s)
Neuronas Motoras/metabolismo , Estrés Oxidativo/fisiología , Proteínas Proto-Oncogénicas c-akt/metabolismo , Traumatismos de la Médula Espinal/metabolismo , Médula Espinal/metabolismo , Proteína Letal Asociada a bcl/metabolismo , Proteínas 14-3-3/metabolismo , Animales , Animales Modificados Genéticamente , Supervivencia Celular/genética , Modelos Animales de Enfermedad , Femenino , Humanos , Neuronas Motoras/patología , Degeneración Nerviosa/genética , Degeneración Nerviosa/metabolismo , Degeneración Nerviosa/fisiopatología , Fosfatidilinositol 3-Quinasas/metabolismo , Fosforilación , Proteínas Proto-Oncogénicas c-akt/genética , Ratas , Ratas Sprague-Dawley , Transducción de Señal/genética , Médula Espinal/patología , Médula Espinal/fisiopatología , Traumatismos de la Médula Espinal/genética , Traumatismos de la Médula Espinal/fisiopatología , Superóxido Dismutasa/genética , Superóxido Dismutasa/metabolismo , Superóxido Dismutasa-1 , Regulación hacia Arriba/genética , Proteína Letal Asociada a bcl/genética , Proteína bcl-X/metabolismo
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