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1.
Bioresour Bioprocess ; 11(1): 25, 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38647931

RESUMEN

Monoclonal antibodies (mAbs) require a high level of purity for regulatory approval and safe administration. High-molecular weight (HMW) species are a common impurity associated with mAb therapies. Hydrophobic interaction chromatography (HIC) resins are often used to remove these HMW impurities. Determination of a suitable HIC resin can be a time and resource-intensive process. In this study, we modeled the chromatographic behavior of seven mAbs across 13 HIC resins using measurements of surface hydrophobicity, surface charge, and thermal stability for mAbs, and hydrophobicity and zeta-potential for HIC resins with high fit quality (adjusted R2 > 0.80). We identified zeta-potential as a novel key modeling parameter. When using these models to select a HIC resin for HMW clearance of a test mAb, we were able to achieve 60% HMW clearance and 89% recovery. These models can be used to expedite the downstream process development for mAbs in an industry setting.

2.
J Biol Inorg Chem ; 29(2): 169-176, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38472487

RESUMEN

Variants in the gene encoding human cytochrome c (CYCS) cause mild autosomal dominant thrombocytopenia. Despite high sequence conservation between mouse and human cytochrome c, this phenotype is not recapitulated in mice for the sole mutant (G41S) that has been investigated. The effect of the G41S mutation on the in vitro activities of cytochrome c is also not conserved between human and mouse. Peroxidase activity is increased in both mouse and human G41S variants, whereas apoptosome activation is increased for human G41S cytochrome c but decreased for mouse G41S cytochrome c. These apoptotic activities of cytochrome c are regulated at least in part by conformational dynamics of the main chain. Here we use computational and in vitro approaches to understand why the impact of the G41S mutation differs between mouse and human cytochromes c. The G41S mutation increases the inherent entropy and main chain mobility of human but not mouse cytochrome c. Exclusively in human G41S cytochrome c this is accompanied by a decrease in occupancy of H-bonds between protein and heme during simulations. These data demonstrate that binding of cytochrome c to Apaf-1 to trigger apoptosome formation, but not the peroxidase activity of cytochrome c, is enhanced by increased mobility of the native protein conformation.


Asunto(s)
Citocromos c , Activación Enzimática , Mutación , Conformación Proteica , Citocromos c/metabolismo , Citocromos c/genética , Citocromos c/química , Humanos , Animales , Ratones , Especificidad de la Especie , Simulación de Dinámica Molecular , Caspasas/metabolismo , Caspasas/genética , Caspasas/química
3.
BMJ Open Sport Exerc Med ; 7(1): e001006, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33768962

RESUMEN

OBJECTIVES: To determine professional footballers' level of understanding of the purpose of the precompetition medical assessment (PCMA) and to evaluate their knowledge of potential outcomes following a PCMA, including disqualification. METHODS: Professional footballers from the Australasian A-League and Westfield W-League were asked to complete a 25-question survey. The relationship between dichotomised outcomes and explanatory variables was analysed with multivariate logistic regression; p<0.05 was considered statistically significant. RESULTS: A total of 212 players participated (response rate=48.8%). Most respondents selected 'To detect medical conditions that may affect performance' and 'To detect current injuries' (n=137, 64.6%; n=130, 61.3%) as the purpose of a PCMA. Approximately one-third (n=74, 38.1%) were neutral or believed that a normal PCMA prevented cardiac arrest. Receiving more PCMAs (p<0.0003) and receiving an explanation during their PCMA (p=0.0175) led to greater awareness of the assessment's limitations. Most participants did not know the definitions of syncope (n=181, 93.3%) or Marfan syndrome (n=183, 94.3%). Fifty players (28.1%) did not know that disqualification was a possible outcome of a PCMA, and younger players were less aware of this possible outcome (p=0.0216). CONCLUSION: Professional footballers appear to have a limited understanding of the purpose of a PCMA, emphasising the musculoskeletal system and performance. They also appear unfamiliar with the components of the PCMA and medical terms. Finally, many are unaware that disqualification can result from an abnormal PCMA. Player health knowledge must be improved; the informed consent process appears an ideal time to provide this education.

4.
Int J Infect Dis ; 101: 74-82, 2020 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-32947055

RESUMEN

OBJECTIVES: To develop: (1) two validated risk prediction models for coronavirus disease-2019 (COVID-19) positivity using readily available parameters in a general hospital setting; (2) nomograms and probabilities to allow clinical utilisation. METHODS: Patients with and without COVID-19 were included from 4 Hong Kong hospitals. The database was randomly split into 2:1: for model development database (n = 895) and validation database (n = 435). Multivariable logistic regression was utilised for model creation and validated with the Hosmer-Lemeshow (H-L) test and calibration plot. Nomograms and probabilities set at 0.1, 0.2, 0.4 and 0.6 were calculated to determine sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). RESULTS: A total of 1330 patients (mean age 58.2 ± 24.5 years; 50.7% males; 296 COVID-19 positive) were recruited. The first prediction model developed had age, total white blood cell count, chest x-ray appearances and contact history as significant predictors (AUC = 0.911 [CI = 0.880-0.941]). The second model developed has the same variables except contact history (AUC = 0.880 [CI = 0.844-0.916]). Both were externally validated on the H-L test (p = 0.781 and 0.155, respectively) and calibration plot. Models were converted to nomograms. Lower probabilities give higher sensitivity and NPV; higher probabilities give higher specificity and PPV. CONCLUSION: Two simple-to-use validated nomograms were developed with excellent AUCs based on readily available parameters and can be considered for clinical utilisation.


Asunto(s)
COVID-19/diagnóstico , SARS-CoV-2 , Adulto , Anciano , Anciano de 80 o más Años , Área Bajo la Curva , COVID-19/etiología , Femenino , Hospitales , Humanos , Modelos Logísticos , Masculino , Persona de Mediana Edad , Nomogramas , Probabilidad
5.
J Thorac Imaging ; 35(6): 369-376, 2020 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-32969949

RESUMEN

PURPOSE: To evaluate the performance of a deep learning (DL) algorithm for the detection of COVID-19 on chest radiographs (CXR). MATERIALS AND METHODS: In this retrospective study, a DL model was trained on 112,120 CXR images with 14 labeled classifiers (ChestX-ray14) and fine-tuned using initial CXR on hospital admission of 509 patients, who had undergone COVID-19 reverse transcriptase-polymerase chain reaction (RT-PCR). The test set consisted of a CXR on presentation of 248 individuals suspected of COVID-19 pneumonia between February 16 and March 3, 2020 from 4 centers (72 RT-PCR positives and 176 RT-PCR negatives). The CXR were independently reviewed by 3 radiologists and using the DL algorithm. Diagnostic performance was compared with radiologists' performance and was assessed by area under the receiver operating characteristics (AUC). RESULTS: The median age of the subjects in the test set was 61 (interquartile range: 39 to 79) years (51% male). The DL algorithm achieved an AUC of 0.81, sensitivity of 0.85, and specificity of 0.72 in detecting COVID-19 using RT-PCR as the reference standard. On subgroup analyses, the model achieved an AUC of 0.79, sensitivity of 0.80, and specificity of 0.74 in detecting COVID-19 in patients presented with fever or respiratory systems and an AUC of 0.87, sensitivity of 0.85, and specificity of 0.81 in distinguishing COVID-19 from other forms of pneumonia. The algorithm significantly outperforms human readers (P<0.001 using DeLong test) with higher sensitivity (P=0.01 using McNemar test). CONCLUSIONS: A DL algorithm (COV19NET) for the detection of COVID-19 on chest radiographs can potentially be an effective tool in triaging patients, particularly in resource-stretched health-care systems.


Asunto(s)
COVID-19/diagnóstico por imagen , Aprendizaje Profundo , Pulmón/diagnóstico por imagen , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Radiografía Torácica/métodos , Adulto , Anciano , Algoritmos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , SARS-CoV-2 , Sensibilidad y Especificidad , Adulto Joven
6.
Radiology ; 296(2): E72-E78, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32216717

RESUMEN

Background Current coronavirus disease 2019 (COVID-19) radiologic literature is dominated by CT, and a detailed description of chest radiography appearances in relation to the disease time course is lacking. Purpose To describe the time course and severity of findings of COVID-19 at chest radiography and correlate these with real-time reverse transcription polymerase chain reaction (RT-PCR) testing for severe acute respiratory syndrome coronavirus 2, or SARS-CoV-2, nucleic acid. Materials and Methods This is a retrospective study of patients with COVID-19 confirmed by using RT-PCR and chest radiographic examinations who were admitted across four hospitals and evaluated between January and March 2020. Baseline and serial chest radiographs (n = 255) were reviewed with RT-PCR. Correlation with concurrent CT examinations (n = 28) was performed when available. Two radiologists scored each chest radiograph in consensus for consolidation, ground-glass opacity, location, and pleural fluid. A severity index was determined for each lung. The lung scores were summed to produce the final severity score. Results The study was composed of 64 patients (26 men; mean age, 56 years ± 19 [standard deviation]). Of these, 58 patients had initial positive findings with RT-PCR (91%; 95% confidence interval: 81%, 96%), 44 patients had abnormal findings at baseline chest radiography (69%; 95% confidence interval: 56%, 80%), and 38 patients had initial positive findings with RT-PCR testing and abnormal findings at baseline chest radiography (59%; 95% confidence interval: 46%, 71%). Six patients (9%) showed abnormalities at chest radiography before eventually testing positive for COVID-19 with RT-PCR. Sensitivity of initial RT-PCR (91%; 95% confidence interval: 83%, 97%) was higher than that of baseline chest radiography (69%; 95% confidence interval: 56%, 80%) (P = .009). Radiographic recovery (mean, 6 days ± 5) and virologic recovery (mean, 8 days ± 6) were not significantly different (P = .33). Consolidation was the most common finding (30 of 64; 47%) followed by ground-glass opacities (21 of 64; 33%). Abnormalities at chest radiography had a peripheral distribution (26 of 64; 41%) and lower zone distribution (32 of 64; 50%) with bilateral involvement (32 of 64; 50%). Pleural effusion was uncommon (two of 64; 3%). The severity of findings at chest radiography peaked at 10-12 days from the date of symptom onset. Conclusion Findings at chest radiography in patients with coronavirus disease 2019 frequently showed bilateral lower zone consolidation, which peaked at 10-12 days from symptom onset. © RSNA, 2020.


Asunto(s)
Betacoronavirus , Infecciones por Coronavirus/diagnóstico por imagen , Neumonía Viral/diagnóstico por imagen , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , COVID-19 , Prueba de COVID-19 , Vacunas contra la COVID-19 , Técnicas de Laboratorio Clínico/métodos , Infecciones por Coronavirus/complicaciones , Infecciones por Coronavirus/diagnóstico , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pandemias , Neumonía Viral/complicaciones , Neumonía Viral/virología , Interpretación de Imagen Radiográfica Asistida por Computador/métodos , Reproducibilidad de los Resultados , Estudios Retrospectivos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa/métodos , SARS-CoV-2 , Índice de Severidad de la Enfermedad , Tomografía Computarizada por Rayos X/métodos , Adulto Joven
7.
Blood Adv ; 3(14): 2218-2229, 2019 07 23.
Artículo en Inglés | MEDLINE | ID: mdl-31332045

RESUMEN

The investigation of extracorporeal photopheresis (ECP) plus standard of care (SoC) (SoC+ECP) in chronic graft-versus-host disease (cGVHD) within prospective, randomized clinical studies is limited, despite its frequent clinical use. This phase 1/pilot study was the first randomized, prospective study to investigate ECP use as first-line therapy in cGVHD, based on the 2015 National Institutes of Health (NIH) consensus criteria for diagnosis and response assessment. Adult patients with new-onset (≤3 years of hematopoietic stem cell transplantation) moderate or severe cGVHD were randomized 1:1 to 26 weeks of SoC+ECP vs SoC (corticosteroids and cyclosporine A/tacrolimus) between 2011 and 2015. The primary endpoint was overall response rate (ORR), defined as complete or partial response, at week 28 in the intention-to-treat population (ITT). Other outcomes included quality of life (QoL) measures and safety. Sixty patients were randomized; ITT included 53 patients (SoC+ECP: 29; SoC: 24). Week 28 ORR was 74.1% (SoC+ECP) and 60.9% (SoC). Investigator-assessed ORR was 56.0% (SoC+ECP) and 66.7% (SoC). Patients treated with SoC experienced a decline in QoL over the 28-week study period; QoL remained unchanged in SoC+ECP patients. Most frequent treatment-emergent adverse events (TEAEs) in SoC+ECP patients were hypertension (31.0%), cough (20.7%), dyspnea (17.2%), and fatigue (17.2%). Seventeen patients (SoC+ECP: 8; SoC: 9) experienced 35 serious adverse events (SAEs). No TEAEs or SAEs were considered related to the ECP instrument or methoxsalen. The encouraging short-term results of this study could inform the design of subsequent studies. This trial was registered at www.clinicaltrials.gov as #NCT01380535.


Asunto(s)
Enfermedad Injerto contra Huésped/diagnóstico , Enfermedad Injerto contra Huésped/terapia , Metoxaleno/administración & dosificación , Fotoféresis , Adulto , Anciano , Femenino , Enfermedad Injerto contra Huésped/etiología , Trasplante de Células Madre Hematopoyéticas/efectos adversos , Humanos , Masculino , Metoxaleno/farmacología , Persona de Mediana Edad , Fotoféresis/métodos , Calidad de Vida , Índice de Severidad de la Enfermedad , Resultado del Tratamiento , Adulto Joven
8.
World J Pediatr Congenit Heart Surg ; 9(5): 550-556, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-30157737

RESUMEN

BACKGROUND: In patients with trisomy 18, congenital heart surgery is controversial due to anticipated poor patient outcome. Data are lacking regarding clinical outcomes and family opinions about care received. METHODS: A retrospective chart review of patients with trisomy 18 and congenital heart disease from 2005 to 2017 was performed. Patients were grouped into those receiving cardiac intervention (surgery or cardiac catheterization) versus medical management. A telephone survey was used to assess completeness of family counseling provided prior to treatment selection and parental opinions on the care received. RESULTS: Seventeen infants were assessed. In the medical management group (n = 7), there were five deaths at a median age of 1.5 months (range: 1.2-4.1 months) and two survivors aged 29 and 44 months at latest follow-up. In the intervention group (n = 10), cardiac surgery was performed in nine patients at a median age of 4.3 months (0.2-23.4 months) and weight of 3.2 kg (1.5-12.2 kg); catheter intervention was performed in one patient at one week of age. At latest follow-up, seven intervention patients are alive at a median age of 50 months (5-91 months). Survey respondents (n = 12) unanimously stated that their child's quality of life was improved by their specific treatment strategy, that the experience of the parents was enhanced, and that they would choose the same treatment course again. CONCLUSIONS: Surgical repair may be associated with favorable early outcomes and may be judiciously offered in selected circumstances. In this limited experience, parental perceptions were positive regarding the quality of care and overall experience independent of the chosen treatment strategy or eventual outcome.


Asunto(s)
Procedimientos Quirúrgicos Cardíacos/métodos , Padres/psicología , Síndrome de la Trisomía 18/cirugía , Femenino , Humanos , Lactante , Masculino , Calidad de Vida , Estudios Retrospectivos , Encuestas y Cuestionarios , Resultado del Tratamiento
9.
Clin Transplant ; 31(4)2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-28135781

RESUMEN

BACKGROUND: Traditionally, living donor kidney transplant (LDKT) rate has been calculated as a percentage of total kidney transplant volume. We believe this calculation to be inherently flawed because the number of deceased donor kidney transplants has no bearing on the number of LDKT performed. We propose an alternative calculation of LDKT rate as a percentage of the number of new waitlist registrants. METHODS: We evaluated 192 adult transplant centers in the United States with respect to their LDKT rate according to both the traditional and proposed calculations, using data from the scientific registry of transplant recipients between July 2014 and June 2015. RESULTS: The median LDKT rate for every 100 new waitlist registrants was 12.3, compared to 27.9 for every 100 total kidney transplants. Based on our proposed calculation of LDKT rate, 16.7% of transplant centers were misevaluated when compared to the national mean using the traditional method. CONCLUSIONS: A new calculation of LDKT rate based on new waitlist registrants, and not total kidney transplants, is necessary to eliminate the bias associated with the traditional method, allowing for the identification of centers for improvement as well as each individual center's true potential based on their patient demographics.


Asunto(s)
Trasplante de Riñón , Donadores Vivos , Sistema de Registros/estadística & datos numéricos , Obtención de Tejidos y Órganos , Listas de Espera , Adolescente , Adulto , Anciano , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Receptores de Trasplantes , Adulto Joven
10.
Catheter Cardiovasc Interv ; 89(3): 495-498, 2017 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-26332842

RESUMEN

For appropriate patients with severe symptomatic aortic stenosis with a prohibitively high surgical risk, trans-catheter aortic valve replacement (TAVR) is now established as a viable option. Thrombosis on the intra-ventricular guide-wire during TAVR is a recognized complication (Wiper et al., Cardiovasc Revasc Med 2014). There is an obvious potential for embolization with particular concern for stroke in this situation. We describe a case in which a >1cm thrombus was noted on the intra-ventricular guide-wire by trans-esophageal echocardiogram (TEE) during a TAVR procedure. Balloon aortic valvuloplasty was still performed and an Edwards Sapien valve was deployed. After valve deployment a multi-purpose guiding catheter was advanced with continuous suction. The guide-wire and thrombus were withdrawn inside the guiding catheter. The guide-wire and catheter were removed as a single unit, allowing the thrombus to be safely retrieved. We believe that this is a novel technique of aspiration thrombectomy in this potentially hazardous clinical circumstance. As our experience with TAVR increases, so does our experience with the complications. In the PARTNER trial there was a higher rate of neurological events in TAVR patients than those who had open aortic valve replacement (Smith et al. N Engl J Med 2011;364:2187-2198.). This may be related to peri-procedural formation of thrombus and subsequent embolization. We report a case where a large guide-wire thrombus identified during TAVR was successfully removed using a novel approach, preventing a potentially major stroke in this high-risk patient. © 2015 Wiley Periodicals, Inc.


Asunto(s)
Estenosis de la Válvula Aórtica/terapia , Válvula Aórtica , Cateterismo Cardíaco/instrumentación , Catéteres Cardíacos , Implantación de Prótesis de Válvulas Cardíacas/instrumentación , Trombectomía , Trombosis/terapia , Anciano de 80 o más Años , Válvula Aórtica/diagnóstico por imagen , Válvula Aórtica/fisiopatología , Estenosis de la Válvula Aórtica/diagnóstico por imagen , Estenosis de la Válvula Aórtica/fisiopatología , Valvuloplastia con Balón , Cateterismo Cardíaco/efectos adversos , Cateterismo Cardíaco/métodos , Ecocardiografía Transesofágica , Diseño de Equipo , Femenino , Implantación de Prótesis de Válvulas Cardíacas/efectos adversos , Implantación de Prótesis de Válvulas Cardíacas/métodos , Humanos , Índice de Severidad de la Enfermedad , Trombosis/diagnóstico por imagen , Trombosis/etiología , Resultado del Tratamiento
11.
Pediatr Cardiol ; 37(5): 919-24, 2016 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-27033242

RESUMEN

Left ventricular hypertrabeculation/noncompaction (LVHT) is a cardiac abnormality of unknown etiology. Prenatal diagnosis of LVHT can be established by fetal echocardiography. A review of 106 published cases showed that 46 cases with prenatally diagnosed LVHT were alive 0.5-120 months after birth. Since the course of cases with prenatally LVHT after publication is unknown, we aimed to collect follow-up-information. Information regarding vital status, cardiac and extracardiac morbidity was gathered by contacting the authors of the 46 cases. Fourteen of the 28 authors answered and gave information about 18 cases (six females, seven males, five gender-unknown, age 18 months to 10 years, mean follow-up 60 months). No differences were found between the 18 cases with follow-up and the 28 cases without follow-up regarding age, gender, cardiac or extracardiac comorbidities, and interventions. Three of the 18 cases had died subsequently from heart failure, osteosarcoma, and enterocolitis, respectively. Mutations or chromosomal abnormalities were found in six of the seven examined patients, extracardiac abnormalities in nine patients. Three patients received a pacemaker because of complete AV block, and two patients underwent heart transplantation. Cardiac surgical or interventional procedures were carried out in four patients. None suffered from malignant arrhythmias or had a cardioverter-defibrillator implanted. Based on the limited information, there are indications that cases with fetal diagnosis of LVHT have a continuing morbidity and mortality, even if they receive appropriate care. Since fetal LVHT is frequently associated with genetic abnormalities, further research about survival and underlying genetic causes is needed.


Asunto(s)
Cardiopatías Congénitas , Arritmias Cardíacas , Niño , Preescolar , Ecocardiografía , Electrocardiografía , Femenino , Humanos , Lactante , Masculino , Enfermedades Neuromusculares
12.
Hosp Pract (1995) ; 43(4): 235-44, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26414594

RESUMEN

New postoperative atrial fibrillation (POAF) is the most common perioperative arrhythmia and its reported incidence ranges from 0.4 to 26% in patients undergoing non-cardiac non-thoracic surgery. The incidence varies according to patient characteristics such as age, presence of structural heart disease and other co-morbidities, as well as the type of surgery performed. POAF occurs as a consequence of adrenergic stimulation, systemic inflammation, or autonomic activation in the intra or postoperative period (e.g. due to pain, hypotension, infection) in the setting of a susceptible myocardium and other predisposing factors (e.g. electrolyte abnormalities). POAF develops between day 1 and day 4 post-surgery and it is often considered a self-limited entity. Its acute management involves many of the same strategies used in non-surgical patients but the optimal long-term management is challenging because of the limited available evidence. Several studies have shown an association between occurrence of POAF and in-hospital morbidity, mortality, and length of stay. Although, traditionally, POAF was considered to have a generally favorable long-term prognosis, recent data have shown an association with an increased risk of stroke at 1 year after hospitalization. It is unknown, however, whether strategies to prevent POAF or for rate/rhythm control when it does occur, lead to a reduction in morbidity or mortality. This suggests the need for future studies to better understand the risks associated with POAF and to determine optimal strategies to minimize long-term thromboembolic risks. In this article, we summarize the current knowledge on epidemiology, pathophysiology, and short- and long-term management of POAF after non-cardiac non-thoracic surgery with the goal of providing a practical approach to managing these patients for the non-cardiologist clinician.


Asunto(s)
Fibrilación Atrial/epidemiología , Fibrilación Atrial/fisiopatología , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/fisiopatología , Factores de Edad , Antiarrítmicos/uso terapéutico , Fibrilación Atrial/etiología , Fibrilación Atrial/terapia , Comorbilidad , Fibrinolíticos/uso terapéutico , Médicos Hospitalarios , Humanos , Incidencia , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/terapia , Estudios Retrospectivos , Factores de Riesgo , Procedimientos Quirúrgicos Operativos/clasificación , Factores de Tiempo
13.
Clin Cancer Res ; 19(11): 3050-8, 2013 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-23536435

RESUMEN

PURPOSE: Testing of promising drug combinations is crucial in the treatment of diffuse intrinsic pontine glioma (DIPG). As the VEGF and platelet-derived growth factor (PDGF) pathways are critical in gliomas, we evaluated the safety, maximum tolerated dose (MTD), pharmacokinetics, and pharmacodynamics of vandetanib, a VEGFR-2 inhibitor, combined with dasatinib, a potent PDGFR inhibitor, during and after radiotherapy in children with newly diagnosed DIPG. EXPERIMENTAL DESIGN: Dasatinib was started concurrently with radiotherapy. Vandetanib was started 8 days later. We tested increasing doses of vandetanib (65 and 85 mg/m(2) once daily) and dasatinib (65 and 85 mg/m(2) twice daily). Dose-limiting toxicities were evaluated during the first 6 weeks of therapy. Plasma pharmacokinetics was obtained on days 8 and 42 ± 3 in all patients and concomitantly with cerebrospinal fluid (CSF) when possible. Inhibition of targets of dasatinib in peripheral blood mononuclear cells (PBMC) was evaluated. RESULTS: Twenty-five patients were treated. Treatment was well tolerated. The median duration of treatment was 184 days. Diarrhea was the most significant toxicity. Three patients experienced substantial myelosuppression. The steady-state plasma pharmacokinetics of vandetanib was comparable with previous studies. Although the plasma exposure to dasatinib decreased from days 8 to 42, it remained similar to adult studies. CSF to plasma exposure of vandetanib and dasatinib were approximately 2% in 2 patients. Phosphorylated 70S6K decreased during therapy in PBMCs. CONCLUSIONS: The MTD of vandetanib and dasatinib in combination was 65 mg/m(2) for each drug. Other studies are underway to test dasatinib and other PDGFR inhibitors alone or in combination for this deadly cancer.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias del Tronco Encefálico/tratamiento farmacológico , Glioma/tratamiento farmacológico , Adolescente , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Neoplasias del Tronco Encefálico/mortalidad , Niño , Preescolar , Dasatinib , Femenino , Glioma/mortalidad , Humanos , Masculino , Piperidinas/administración & dosificación , Piperidinas/farmacocinética , Pirimidinas/administración & dosificación , Pirimidinas/farmacocinética , Quinazolinas/administración & dosificación , Quinazolinas/farmacocinética , Tiazoles/administración & dosificación , Tiazoles/farmacocinética , Resultado del Tratamiento
15.
Artículo en Inglés | MEDLINE | ID: mdl-23192801

RESUMEN

This paper reports on direct thermal to electrical energy conversion by performing the Olsen cycle on 9.5/65/35 lead lanthanum zirconate titanate (PLZT). The Olsen cycle consists of two isothermal and two isoelectric field processes in the electric displacement versus electric field diagram. It was performed by alternatively dipping the material in hot and cold dielectric fluid baths under specified electric fields. The effects of applied electric field, sample thickness, electrode material, operating temperature, and cycle frequency on the energy and power densities were investigated. A maximum energy density of 637 ± 20 J/L/cycle was achieved at 0.054 Hz with a 250-µm-thick sample featuring Pt electrodes and coated with a silicone conformal coating. The operating temperatures varied between 3°C and 140°C and the electric field was cycled between 0.2 and 6.0 MV/m. A maximum power density of 55 ± 8 W/L was obtained at 0.125 Hz under the same operating temperatures and electric fields. The dielectric strength of the material, and therefore the energy and power densities generated, increased when the sample thickness decreased from 500 to 250 µm. Furthermore, the electrode material was found to have no significant effect on the energy and power densities for samples subject to the same operating temperatures and electric fields. However, samples with electrode material possessing thermal expansion coefficients similar to that of PLZT were capable of withstanding larger temperature swings. Finally, a fatigue test showed that the power generation gradually degraded when the sample was subject to repeated thermoelectrical loading.

16.
World J Pediatr Congenit Heart Surg ; 3(4): 459-62, 2012 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-23804909

RESUMEN

OBJECTIVES: Incisions in the left ventricle have previously been associated with increased mortality and morbidity, particularly in infants. In order to determine whether this assumption is still true in the current era, we reviewed our recent experience with apical left ventriculotomy in neonates and infants. METHODS: The records of five consecutive patients requiring a left ventriculotomy between 2007 and 2010 were reviewed. Weight and age ranged from 2.6 to 16 kilograms and 5 days to 2 years. The diagnoses were three multiple ventricular septal defects, one rhabdomyoma, and one apical aneurysm. The primary end point was left ventricular ejection fraction, with other end points being intensive care unit length of stay, time to extubation, inotrope requirement, arrhythmias, and mitral valve function. RESULTS: There were no early or late deaths. Although lower than their preoperative values, early postoperative ejection fractions were greater than 50% in all patients. Two patients required no inotropes, and 3 required only minimal support. Hospital length of stay was 9 ± 7 days for multiple ventricular septal defect patients, with intensive care unit stays of 2 to 5 days. There were no postoperative arrhythmias requiring pharmacological therapy, and one patient had a significant reduction in mitral insufficiency postoperatively. CONCLUSIONS: Based on our experience, we believe that an apical left ventriculotomy does not significantly impair left ventricular function even in small infants, and is not associated with significant morbidity, based on short-term follow-up. Although the long-term effects are still unknown, early results suggest that a left ventriculotomy may safely be used when alternative approaches are inadequate for complex cardiac defects.

17.
J Thorac Cardiovasc Surg ; 141(5): 1163-9, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21353250

RESUMEN

OBJECTIVE: The purpose of this study was to review the long-term outcome of patients with Ebstein anomaly who underwent complete repair as neonates and young infants. METHODS: Between March 1994 and May 2010, 32 patients (23 neonates and 9 young infants) underwent surgery for Ebstein anomaly. Mean weight was 3.9 ± 2.0 kg (range, 1.9-8.6 kg). The Great Ormond Street Echocardiography score was greater than 1.5 in 22 of the 23 neonates and greater than 1.0 in all infants. All associated cardiac defects were repaired including pulmonary atresia in 15 and ventricular septal defect in 4. Primary outcome measures included (1) early and late survival, (2) freedom from reoperation, (3) durability of tricuspid valve repair, and (4) functional status. RESULTS: Early survival was 78.1% (25/32). There was 1 late death. Fifteen-year survival estimate was 74% ± 8%. For patients with pulmonary atresia, early and late survival was 60% ± 12% (9/15) versus 94.1% (16/17) (P < .05), respectively; for those without pulmonary atresia, early and late survival was 60% ± 12% versus 85% ± 10 (P = .06), respectively. The mean follow-up was 5.9 ± 4.5 years (0.1-16 years). A biventricular repair was achieved in 90.6% (29/32) patients. Median preoperative tricuspid regurgitation was 4/4 and at late follow-up, 1/4. Freedom from reoperation at 15 years was 74% ± 10% for patients undergoing biventricular repair. All survivors are in New York Heart Association class I or II. CONCLUSIONS: Biventricular repair of Ebstein anomaly in symptomatic neonates is feasible with good early and late survival, especially in those without pulmonary atresia. Tricuspid valve repair is durable, and functional status is excellent.


Asunto(s)
Procedimientos Quirúrgicos Cardíacos , Anomalía de Ebstein/cirugía , Procedimientos Quirúrgicos Cardíacos/efectos adversos , Procedimientos Quirúrgicos Cardíacos/mortalidad , Anomalía de Ebstein/diagnóstico por imagen , Anomalía de Ebstein/mortalidad , Anomalía de Ebstein/fisiopatología , Estudios de Seguimiento , Mortalidad Hospitalaria , Humanos , Lactante , Recién Nacido , Estimación de Kaplan-Meier , Reoperación , Medición de Riesgo , Factores de Riesgo , Tasa de Supervivencia , Factores de Tiempo , Resultado del Tratamiento , Ultrasonografía , Estados Unidos
18.
World J Pediatr Congenit Heart Surg ; 2(4): 554-7, 2011 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-23804467

RESUMEN

BACKGROUND: The optimal management strategy for neonates with Ebstein's anomaly is unknown. This analysis was undertaken to assess current trends in the management and prognosis of neonates born with Ebstein's anomaly in the United States, as reflected in an administrative database. METHODS: The Pediatric Health Information System database (40 children's hospitals) was used to review the reported incidence and available data on neonates with Ebstein's anomaly treated in the United States between 2003 and 2007. Primary outcome was hospital survival. Of the 415 patients identified, 257 (62%) did not undergo initial surgical intervention as neonates. Aortopulmonary shunt only was done on 63 patients (15%), single-ventricle palliation on 36 (9%), two-ventricle repair on 16 (4%), heart transplantation in 3 (1%), and a catheter-based intervention or a hybrid palliative approach was applied in 40 (10%). Intergroup comparisons were done using chi-square analyses. RESULTS: Mortality for the entire cohort was 24% (100 of 415). For medically treated patients, this was 22% (56 of 257). For surgically treated and hybrid patients, this was 30% and 23%, respectively (P = NS). CONCLUSIONS: The majority of patients born with Ebstein's anomaly currently do not undergo surgical intervention as neonates. Significant early mortality in this group suggests that certain subsets of patients may benefit from earlier surgical intervention. Among the severely symptomatic neonates who do undergo early surgical intervention, the mortality remains high, irrespective of the surgical approach taken. A multicenter trial may be appropriate to identify strategies to optimize care for these critically ill neonates. Further analysis of risk factors for early mortality is warranted.

19.
J Clin Oncol ; 28(31): 4762-8, 2010 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-20921456

RESUMEN

PURPOSE: To evaluate the safety, maximum-tolerated dose, pharmacokinetics, and pharmacodynamics of vandetanib, an oral vascular endothelial growth factor receptor 2 (VEGFR2) and epidermal growth factor receptor inhibitor, administered once daily during and after radiotherapy in children with newly diagnosed diffuse intrinsic pontine glioma. PATIENTS AND METHODS: Radiotherapy was administered as 1.8-Gy fractions (total cumulative dose of 54 Gy). Vandetanib was administered concurrently with radiotherapy for a maximum of 2 years. Dose-limiting toxicities (DLTs) were evaluated during the first 6 weeks of therapy. Pharmacokinetic studies were obtained for all patients. Plasma angiogenic factors and VEGFR2 phosphorylation in mononuclear cells were analyzed before and during therapy. RESULTS: Twenty-one patients were administered 50 (n = 3), 65 (n = 3), 85 (n = 3), 110 (n = 6), and 145 mg/m(2) (n = 6) of vandetanib. Only one patient developed DLT (grade 3 diarrhea) at dosage level 5. An expanded cohort of patients were treated at dosage levels 4 (n = 10) and 5 (n = 4); two patients developed grade 4 hypertension and posterior reversible encephalopathy syndrome while also receiving high-dose dexamethasone. Despite significant interpatient variability, exposure to vandetanib increased with higher dosage levels. The bivariable analysis of vascular endothelial growth factor (VEGF) before and during therapy showed that patients with higher levels of VEGF before therapy had a longer progression-free survival (PFS; P = .022), whereas patients with increases in VEGF during treatment had a shorter PFS (P = .0015). VEGFR2 phosphorylation was inhibited on day 8 or 29 of therapy compared with baseline (P = .039). CONCLUSION: The recommended phase II dose of vandetanib in children is 145 mg/m(2) per day. Close monitoring and management of hypertension is required, particularly for patients receiving corticosteroids.


Asunto(s)
Antineoplásicos/administración & dosificación , Antineoplásicos/farmacocinética , Neoplasias del Tronco Encefálico/tratamiento farmacológico , Neoplasias del Tronco Encefálico/radioterapia , Glioma/tratamiento farmacológico , Glioma/radioterapia , Piperidinas/administración & dosificación , Piperidinas/farmacocinética , Quinazolinas/administración & dosificación , Quinazolinas/farmacocinética , Adolescente , Antineoplásicos/efectos adversos , Neoplasias del Tronco Encefálico/diagnóstico , Quimioterapia Adyuvante , Niño , Preescolar , Supervivencia sin Enfermedad , Fraccionamiento de la Dosis de Radiación , Esquema de Medicación , Femenino , Glioma/diagnóstico , Humanos , Estimación de Kaplan-Meier , Imagen por Resonancia Magnética , Masculino , Dosis Máxima Tolerada , Piperidinas/efectos adversos , Quinazolinas/efectos adversos , Radioterapia Adyuvante , Resultado del Tratamiento , Adulto Joven
20.
J Pediatr ; 156(5): 848-9, 849.e1, 2010 May.
Artículo en Inglés | MEDLINE | ID: mdl-20304430

RESUMEN

Intrapericardial teratomas often present as life-threatening problems when diagnosed during fetal life. They are large lesions that compress the heart and lungs and can result in tamponade if not treated expeditiously. We present a case of a large teratoma that was managed by prenatal pericardiocentesis followed by surgical resection.


Asunto(s)
Enfermedades Fetales/cirugía , Neoplasias Cardíacas/cirugía , Teratoma/cirugía , Femenino , Enfermedades Fetales/diagnóstico por imagen , Feto/cirugía , Neoplasias Cardíacas/diagnóstico por imagen , Humanos , Recién Nacido , Pericardiocentesis , Teratoma/diagnóstico por imagen , Ultrasonografía Prenatal
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