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1.
Epilepsia ; 64(9): 2434-2442, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37349955

RESUMEN

OBJECTIVE: Focal cortical dysplasia (FCD) is the most common etiology of surgically-remediable epilepsy in children. Eighty-seven percent of patients with FCD develop epilepsy (75% is pharmacoresistant epilepsy [PRE]). Focal to bilateral tonic-clonic (FTBTC) seizures are associated with worse surgical outcomes. We hypothesized that children with FCD-related epilepsy with FTBTC seizures are more likely to develop PRE due to lesion interaction with restricted cortical neural networks. METHODS: Patients were selected retrospectively from radiology and surgical databases from Children's National Hospital. INCLUSION CRITERIA: 3T magnetic resonance imaging (MRI)-confirmed FCD from January 2011 to January 2020; ages 0 days to 22 years at MRI; and 18 months of documented follow-up. FCD dominant network (Yeo 7-network parcellation) was determined. Association of FTBTC seizures with epilepsy severity, surgical outcome, and dominant network was tested. Binomial regression was used to evaluate predictors (FTBTC seizures, age at seizure onset, pathology, hemisphere, lobe) of pharmacoresistance and Engel outcome. Regression was used to evaluate predictors (age at seizure onset, pathology, lobe, percentage default mode network [DMN] overlap) of FTBTC seizures. RESULTS: One hundred seventeen patients had a median age at seizure onset of 3.00 years (interquartile range [IQR] .42-5.59 years). Eighty-three patients had PRE (71%); 34 had pharmacosensitive epilepsy (PSE) (29%). Twenty patients (17%) had FTBTC seizures. Seventy-three patients underwent epilepsy surgery. Multivariate regression showed that FTBTC seizures are associated with an increased risk of PRE (odds ratio [OR] 6.41, 95% confidence interval [CI] 1.21-33.98, p = .02). FCD hemisphere/lobe was not associated with PRE. Percentage DMN overlap predicts FTBTC seizures. Seventy-two percent (n = 52) overall and 53% (n = 9) of patients with FTBTC seizures achieved Engel class I outcome. SIGNIFICANCE: In a heterogeneous population of surgical and non-operated patients with FCD-related epilepsy, the presence of FTBTC seizures is associated with a tremendous risk of PRE. This finding is a recognizable marker to help neurologists identify those children with FCD-related epilepsy at high risk of PRE and can flag patients for earlier consideration of potentially curative surgery. The FCD-dominant network also contributes to FTBTC seizure clinical expression.


Asunto(s)
Epilepsia , Displasia Cortical Focal , Malformaciones del Desarrollo Cortical , Niño , Humanos , Estudios Retrospectivos , Resultado del Tratamiento , Convulsiones/diagnóstico por imagen , Convulsiones/etiología , Convulsiones/cirugía , Epilepsia/diagnóstico por imagen , Epilepsia/tratamiento farmacológico , Epilepsia/etiología , Imagen por Resonancia Magnética , Malformaciones del Desarrollo Cortical/complicaciones , Malformaciones del Desarrollo Cortical/diagnóstico por imagen , Malformaciones del Desarrollo Cortical/cirugía
4.
Pediatr Radiol ; 46(1): 145-7, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26260203

RESUMEN

Atelencephaly is a rare lethal congenital brain malformation characterized by underdevelopment of the prosencephalon and is often accompanied by the facial features seen in some cases of holoprosencephaly, such as cyclopia. We report a case of atelencephaly in the fetus with characteristic ultrasound findings. In addition, we report the findings on fetal MRI, which have not been previously described in the literature.


Asunto(s)
Anomalías Múltiples/diagnóstico , Anencefalia/diagnóstico , Aumento de la Imagen/métodos , Imagen por Resonancia Magnética/métodos , Prosencéfalo/anomalías , Ultrasonografía Prenatal/métodos , Diagnóstico Diferencial , Ecoencefalografía/métodos , Femenino , Humanos , Masculino , Prosencéfalo/diagnóstico por imagen
5.
J Pediatr ; 167(5): 1018-24, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26384435

RESUMEN

OBJECTIVE: To compare global and regional cerebral perfusion in newborns with congenital heart disease (CHD) and healthy controls using arterial spin labeling (ASL) magnetic resonance imaging (MRI) prior to open heart surgery. STUDY DESIGN: We performed brain MRIs in 101 newborns (58 controls, 43 CHD) using 3-dimensional fast spin echo pseudo-continuous ASL. Cerebral blood flow (CBF) ASL images were linearly coregistered to T2-weighted images for anatomic delineation and selection of regions-of-interest. Anatomic regions included frontal white matter (FWM), occipital white matter (OWM), thalami, and basal ganglia (BG). RESULTS: Newborns with single ventricle CHD demonstrated significantly lower global (P = .044) and regional BG (P = .025) CBF compared with controls. Mean regional CBF in the thalami in cyanotic newborns with CHD was lower compared with controls (P = .004). Mean regional CBF in thalami (P = .02), BG (P = .01), and OWM (P = .03) among newborns with cyanotic CHD was lower than those with acyanotic CHD. Newborns with CHD ventilated prior to MRI had increased global (P = .016) and OWM (P = .013) CBF compared with those not ventilated. CONCLUSIONS: Newborns with uncorrected cyanotic or single ventricle CHD show disturbances in cerebral perfusion compared to healthy controls using ASL. Cardiac physiology and preoperative hemodynamic compromise play an important role in preoperative alterations in global and regional cerebral perfusion. Our data suggest that ASL may be useful for studying cerebral perfusion in newborns at high risk for cerebral ischemia, such as those with complex CHD.


Asunto(s)
Encéfalo/irrigación sanguínea , Circulación Cerebrovascular/fisiología , Cardiopatías Congénitas/sangre , Imagen por Resonancia Magnética , Velocidad del Flujo Sanguíneo , Encéfalo/patología , Isquemia Encefálica/patología , Procedimientos Quirúrgicos Cardíacos , Femenino , Cardiopatías Congénitas/complicaciones , Hemodinámica , Humanos , Imagenología Tridimensional , Lactante , Recién Nacido , Masculino , Edad Materna , Estudios Prospectivos , Riesgo , Marcadores de Spin
6.
Ann Clin Transl Neurol ; 10(11): 2161-2165, 2023 11.
Artículo en Inglés | MEDLINE | ID: mdl-37700505

RESUMEN

To evaluate the role of focal cortical dysplasia co-localization to cortical functional networks in the development of pharmacoresistance. One hundred thirty-six focal cortical dysplasia patients with 3.0 T or 1.5 T MRI were identified from clinical databases at Children's National Hospital. Clinico-radio-pathologic factors and network co-localization were determined. Using binomial logistic regression, limbic network co-localization (odds ratio 4.164 95% confidence interval 1.02-17.08, p = 0.048), and focal to bilateral tonic-clonic seizures (4.82, 1.30-18.03, p = 0.019) predicted pharmacoresistance. These findings provide clinicians with markers to identify patients with focal cortical dysplasia-related epilepsy at high risk of developing pharmacoresistance and should facilitate earlier epilepsy surgical evaluation.


Asunto(s)
Epilepsia , Displasia Cortical Focal , Niño , Humanos , Epilepsia/tratamiento farmacológico , Epilepsia/etiología , Convulsiones , Modelos Logísticos , Oportunidad Relativa
7.
Pediatr Radiol ; 41(3): 287-98; quiz 404-5, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-21267556

RESUMEN

Masses arising in the sella turcica and the suprasellar region are common in children. The type and frequency of the various lesions encountered in childhood differ from the adult presentation. This article reviews the embryology of the pituitary gland and its normal appearance in childhood as well as the imaging and clinical findings of the common and some of the uncommon lesions arising in the sella turcica, the pituitary stalk, the suprasellar cistern and the lower third ventricle in the pediatric population.


Asunto(s)
Hipófisis/diagnóstico por imagen , Neoplasias Hipofisarias/diagnóstico , Silla Turca/patología , Niño , Humanos , Hipófisis/embriología , Hipófisis/patología , Neoplasias Hipofisarias/diagnóstico por imagen , Radiografía , Silla Turca/diagnóstico por imagen
8.
J Clin Oncol ; 39(24): 2685-2697, 2021 08 20.
Artículo en Inglés | MEDLINE | ID: mdl-34110925

RESUMEN

PURPOSE: Children with average-risk medulloblastoma (MB) experience survival rates of ≥ 80% at the expense of adverse consequences of treatment. Efforts to mitigate these effects include deintensification of craniospinal irradiation (CSI) dose and volume. METHODS: ACNS0331 (ClinicalTrials.gov identifier: NCT00085735) randomly assigned patients age 3-21 years with average-risk MB to receive posterior fossa radiation therapy (PFRT) or involved field radiation therapy (IFRT) following CSI. Young children (3-7 years) were also randomly assigned to receive standard-dose CSI (SDCSI; 23.4 Gy) or low-dose CSI (LDCSI; 18 Gy). Post hoc molecular classification and mutational analysis contextualized outcomes according to known biologic subgroups (Wingless, Sonic Hedgehog, group 3, and group 4) and genetic biomarkers. Neurocognitive changes and ototoxicity were monitored over time. RESULTS: Five hundred forty-nine patients were enrolled on study, of which 464 were eligible and evaluable to compare PFRT versus IFRT and 226 for SDCSI versus LDCSI. The five-year event-free survival (EFS) was 82.5% (95% CI, 77.2 to 87.8) and 80.5% (95% CI, 75.2 to 85.8) for the IFRT and PFRT regimens, respectively, and 71.4% (95% CI, 62.8 to 80) and 82.9% (95% CI, 75.6 to 90.2) for the LDCSI and SDCSI regimens, respectively. IFRT was not inferior to PFRT (hazard ratio, 0.97; 94% upper CI, 1.32). LDCSI was inferior to SDCSI (hazard ratio, 1.67%; 80% upper CI, 2.10). Improved EFS was observed in patients with Sonic Hedgehog MB who were randomly assigned to the IFRT arm (P = .018). Patients with group 4 MB receiving LDCSI exhibited inferior EFS (P = .047). Children receiving SDCSI exhibited greater late declines in IQ (estimate = 5.87; P = .021). CONCLUSION: Reducing the radiation boost volume in average-risk MB is safe and does not compromise survival. Reducing CSI dose in young children with average-risk MB results in inferior outcomes, possibly in a subgroup-dependent manner, but is associated with better neurocognitive outcome. Molecularly informed patient selection warrants further exploration for children with MB to be considered for late-effect sparing approaches.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Meduloblastoma/tratamiento farmacológico , Meduloblastoma/radioterapia , Adolescente , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Niño , Preescolar , Femenino , Humanos , Masculino , Adulto Joven
9.
Brain ; 132(Pt 2): 347-56, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19059978

RESUMEN

Neural networks for processing language often are reorganized in patients with epilepsy. However, the extent and location of within and between hemisphere re-organization are not established. We studied 45 patients, all with a left hemisphere seizure focus (mean age 22.8, seizure onset 13.3), and 19 normal controls (mean age 24.8) with an fMRI word definition language paradigm to assess the location of language processing regions. Individual patient SPM maps were compared to the normal group in a voxel-wise comparison; a voxel was considered to be significant if its z-value exceeded mid R:2mid R:. Subsequently, we used principal component analysis with hierarchical clustering of variance patterns from individual difference maps to identify four patient sub-groups. One did not differ from normal controls; one had increased left temporal activation on the margin of regions activated in controls; two others had recruitment in right inferior frontal gyrus, middle frontal gyrus and temporal cortex. Right hemisphere activation in these two groups occurred in homologues of left hemisphere regions that sustained task activation. Our study used novel data driven methods to find evidence for constraints on inter-hemispheric reorganization of language in recruitment of right homologues, and, in a subpopulation of patients, evidence for intra-hemispheric reorganization of language limited to the margins of typical left temporal regional activation. These methods may be applied to investigate both normal and pathological variance in other developmental disorders and cognitive domains.


Asunto(s)
Epilepsia/fisiopatología , Procesamiento de Imagen Asistido por Computador , Lenguaje , Red Nerviosa/fisiopatología , Adolescente , Adulto , Mapeo Encefálico , Estudios de Casos y Controles , Niño , Femenino , Humanos , Imagen por Resonancia Magnética/métodos , Masculino , Persona de Mediana Edad , Plasticidad Neuronal , Pruebas Neuropsicológicas , Análisis de Componente Principal , Adulto Joven
10.
Epilepsia ; 50(9): 2147-53, 2009 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-19389145

RESUMEN

The International League Against Epilepsy (ILAE) Subcommittee for Pediatric Neuroimaging examined the usefulness of, and indications for, neuroimaging in the evaluation of children with newly diagnosed epilepsy. The retrospective and prospective published series with n > or = 30 utilizing computed tomography (CT) and magnetic resonance imaging (MRI) (1.5 T) that evaluated children with new-onset seizure(s) were reviewed. Nearly 50% of individual imaging studies in children with localization-related new-onset seizure(s) were reported to be abnormal; 15-20% of imaging studies provided useful information on etiology or and seizure focus, and 2-4% provided information that potentially altered immediate medical management. A significant imaging abnormality in the absence of a history of a localization-related seizure, abnormal neurologic examination, or focal electroencephalography (EEG) is rare. Imaging studies in childhood absence epilepsy, juvenile absence epilepsy, juvenile myoclonic epilepsy, and benign childhood epilepsy with centrotemporal spikes (BECTS) do not identify significant structural abnormalities. Imaging provides important contributions to establishing etiology, providing prognostic information, and directing treatment in children with recently diagnosed epilepsy. Imaging is recommended when localization-related epilepsy is known or suspected, when the epilepsy classification is in doubt, or when an epilepsy syndrome with remote symptomatic cause is suspected. When available, MRI is preferred to CT because of its superior resolution, versatility, and lack of radiation.


Asunto(s)
Diagnóstico por Imagen/normas , Epilepsia/diagnóstico , Guías de Práctica Clínica como Asunto/normas , Adolescente , Factores de Edad , Encéfalo/diagnóstico por imagen , Niño , Diagnóstico por Imagen/métodos , Electroencefalografía/métodos , Electroencefalografía/normas , Epilepsias Parciales/diagnóstico , Epilepsia/diagnóstico por imagen , Epilepsia Rolándica/diagnóstico , Femenino , Humanos , Imagen por Resonancia Magnética/normas , Masculino , Examen Neurológico , Cintigrafía , Convulsiones/diagnóstico , Tomografía Computarizada por Rayos X
12.
Oncotarget ; 7(27): 42837-42842, 2016 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-27329600

RESUMEN

There is no curative treatment for patients with diffuse intrinsic pontine glioma (DIPG). However, with the recent availability of biopsy and autopsy tissue, new data regarding the biologic behavior of this tumor have emerged, allowing greater molecular characterization and leading to investigations which may result in improved therapeutic options. Treatment strategies must address both primary disease sites as well as any metastatic deposits, which may be variably sensitive to a particular approach.In this case report, we present a patient with DIPG treated with irradiation and serial investigational agents. The clinical, pathological and molecular phenotypes of both the progressive primary tumor as well as concomitant metastatic deposits obtained at autopsy are discussed. While some mRNA differences were demonstrated, all analyzed sites of disease shared similar mutational arrangements, suggesting that targeting the mutations of the primary tumor may be effective for all sites of disease.


Asunto(s)
Neoplasias Encefálicas/patología , Glioma/patología , Autopsia , Biopsia , Neoplasias del Tronco Encefálico/patología , Niño , Progresión de la Enfermedad , Femenino , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Humanos , Procesamiento de Imagen Asistido por Computador , Imagen por Resonancia Magnética , Mutación , Metástasis de la Neoplasia , Fenotipo , Puente/patología , Análisis de Componente Principal , ARN Mensajero/metabolismo , Resultado del Tratamiento
13.
J Clin Oncol ; 16(9): 3037-43, 1998 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9738573

RESUMEN

PURPOSE: The Children's Cancer Group conducted a phase I trial of temozolomide stratified by prior craniospinal irradiation (CSI). PATIENTS AND METHODS: Children and adolescents with recurrent or progressive cancer were enrolled. Temozolomide was administered orally daily for 5 days, with subsequent courses administered every 21 to 28 days after full hematologic recovery. Dose levels tested included 100, 150, 180, 215, 245, and 260 mg/m2 daily. RESULTS: Twenty-seven patients on the non-CSI stratum were assessable for hematologic toxicity. During the first three dose levels (100, 150, and 180 mg/m2 daily), only grades 1 and 2 hematologic toxicity occurred. One patient at 215 mg/m2 daily had grade 3 hematologic toxicity. Three of eight patients (38%) treated at 245 to 260 mg/m2 daily had dose-limiting toxicity (DLT), which included both neutropenia and thrombocytopenia. Twenty-two patients on the CSI stratum were assessable for hematologic toxicity. Hematologic DLT occurred in one of six patients (17%) at 100 mg/m2 daily and in two of four patients (50%) at 215 mg/m2 daily. No nonhematologic DLT occurred; nausea and vomiting occurred in more than half of the patients. After two courses of temozolomide, 10 patients had stable disease (SD), and three patients had a partial response (PR), one of whom subsequently had a complete response (CR) that persists through 24 months of follow-up. CONCLUSION: The maximum-tolerated dose (MTD) of temozolomide for children and adolescents without prior CSI is 215 mg/m2 daily and for those with prior CSI is 180 mg/m2 daily for 5 days, with subsequent courses that begin on day 28. Temozolomide is well tolerated and should undergo phase II testing in children and adolescents.


Asunto(s)
Antineoplásicos Alquilantes/uso terapéutico , Dacarbazina/análogos & derivados , Recurrencia Local de Neoplasia/tratamiento farmacológico , Neoplasias/tratamiento farmacológico , Adolescente , Adulto , Antineoplásicos Alquilantes/efectos adversos , Niño , Preescolar , Dacarbazina/efectos adversos , Dacarbazina/uso terapéutico , Relación Dosis-Respuesta a Droga , Femenino , Humanos , Masculino , Temozolomida
14.
J Clin Oncol ; 17(7): 2127-36, 1999 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10561268

RESUMEN

PURPOSE: Medulloblastoma is the most common malignant brain tumor of childhood. After treatment with surgery and radiation therapy, approximately 60% of children with medulloblastoma are alive and free of progressive disease 5 years after diagnosis, but many have significant neurocognitive sequelae. This study was undertaken to determine the feasibility and efficacy of treating children with nondisseminated medulloblastoma with reduced-dose craniospinal radiotherapy plus adjuvant chemotherapy. PATIENTS AND METHODS: Over a 3-year period, 65 children between 3 and 10 years of age with nondisseminated medulloblastoma were treated with postoperative, reduced-dose craniospinal radiation therapy (23.4 Gy) and 55.8 Gy of local radiation therapy. Adjuvant vincristine chemotherapy was administered during radiotherapy, and lomustine, vincristine, and cisplatin chemotherapy was administered during and after radiation. RESULTS: Progression-free survival was 86% +/- 4% at 3 years and 79% +/- 7% at 5 years. Sites of relapse for the 14 patients who developed progressive disease included the local tumor site alone in two patients, local tumor site and disseminated disease in nine, and nonprimary sites in three. Brainstem involvement did not adversely affect outcome. Therapy was relatively well tolerated; however, the dose of cisplatin had to be modified in more than 50% of patients before the completion of treatment. One child died of pneumonitis and sepsis during treatment. CONCLUSION: These overall survival rates compare favorably to those obtained in studies using full-dose radiation therapy alone or radiation therapy plus chemotherapy. The results suggest that reduced-dose craniospinal radiation therapy and adjuvant chemotherapy during and after radiation is a feasible approach for children with nondisseminated medulloblastoma.


Asunto(s)
Neoplasias Cerebelosas/radioterapia , Irradiación Craneana/métodos , Meduloblastoma/radioterapia , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias Cerebelosas/tratamiento farmacológico , Neoplasias Cerebelosas/mortalidad , Neoplasias Cerebelosas/patología , Quimioterapia Adyuvante , Niño , Preescolar , Cisplatino/administración & dosificación , Irradiación Craneana/efectos adversos , Supervivencia sin Enfermedad , Humanos , Lomustina/administración & dosificación , Meduloblastoma/tratamiento farmacológico , Meduloblastoma/mortalidad , Meduloblastoma/patología , Estadificación de Neoplasias , Dosis de Radiación , Tasa de Supervivencia , Estados Unidos/epidemiología , Vincristina/administración & dosificación
15.
J Clin Oncol ; 20(16): 3431-7, 2002 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-12177103

RESUMEN

PURPOSE: This Children's Cancer Group group-wide phase II trial evaluated the efficacy and toxicity of two chemotherapy arms administered before hyperfractionated external-beam radiotherapy (HFEBRT). PATIENTS AND METHODS: Thirty-two patients with newly diagnosed brainstem gliomas were randomly assigned to regimen A and 31 to regimen B. Regimen A comprised three courses of carboplatin, etoposide, and vincristine; regimen B comprised cisplatin, etoposide, cyclophosphamide, and vincristine. Both arms included granulocyte colony-stimulating factor. Patients were evaluated by magnetic resonance imaging after induction chemotherapy and HFEBRT at a dose of 72 Gy. RESULTS: Ten percent +/- 5% of regimen A patients objectively responded to chemotherapy. For combined induction and radiotherapy, 27% +/- 9% of patients improved. The neuroradiographic response rate for regimen B was 19% +/- 8% for chemotherapy and 23% +/- 9% after HFEBRT. Response rates were not statistically significant between regimens after induction or chemotherapy/HFEBRT. Event-free survival was 17% +/- 5% (estimate +/- SE) at 1 year and 6% +/- 3% at 2 years. Survival was significantly longer among patients who responded to chemotherapy (P <.05). Among patients who received regimen A induction, grades 3 and 4 leukopenia were observed in 50% to 65%, with one toxicity-related death. For regimen B, severe leukopenia occurred in 86% to 100%, with febrile neutropenia in 48% to 60% per course. CONCLUSION: Neither chemotherapy regimen meaningfully improved response rate, event-free survival, or overall survival relative to previous series of patients with brainstem gliomas who received radiotherapy with or without chemotherapy.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias del Tronco Encefálico/tratamiento farmacológico , Glioma/tratamiento farmacológico , Adolescente , Análisis de Varianza , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Neoplasias del Tronco Encefálico/mortalidad , Neoplasias del Tronco Encefálico/radioterapia , Carboplatino/administración & dosificación , Niño , Preescolar , Cisplatino/administración & dosificación , Ciclofosfamida/administración & dosificación , Supervivencia sin Enfermedad , Etopósido/administración & dosificación , Femenino , Glioma/radioterapia , Humanos , Masculino , Terapia Neoadyuvante , Tasa de Supervivencia , Vincristina/administración & dosificación
16.
Plant Physiol ; 102(1): 213-218, 1993 May.
Artículo en Inglés | MEDLINE | ID: mdl-12231812

RESUMEN

Acceleration of membrane deterioration has been observed recently during storage of [gamma]-irradiated cauliflower (Brassica oleracea L., Botrytis group). In the present study, the activity of microsome-associated lipolytic enzymes was investigated in cauliflower florets exposed to 0 or 4 kilograys of [gamma] radiation and stored for 8 d at 13[deg]C. Radiolabeled breakdown products obtained from the metabolism of (16:0/18:2*)-phosphatidylcholine and (16:0/16:0)-phosphatidyl-[N-methyl-3H]choline by microsomal membranes indicated that phospholipase D (EC 3.1.4.4), phosphatidic acid phosphatase (EC 3.1.3.4), and lipolytic acyl hydrolase were associated with the membranes. The rate of phosphatidylcholine catabolism by the membranes increased slowly in control cauliflower during storage. [gamma] irradiation caused an immediate rise in phosphatidylcholine catabolism that remained higher than that of the controls during subsequent storage. Collectively, the data suggest that enhancement of membrane lipolytic activity results from free-radical-induced stress. Rapid increase of the membrane-associated phospholipase D activity may be a key event leading to accelerated membrane deterioration following [gamma] irradiation.

17.
Mol Plant Microbe Interact ; 13(11): 1271-4, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11059495

RESUMEN

P121R25 is a Tn5-induced mutant of the effective Rhizobium leguminosarum bv. phaseoli strain P121R that is unable to use glutamate as the sole carbon and nitrogen source and is defective in symbiotic nitrogen fixation. Enzymatic analysis showed that three enzymes implicated in glutamate metabolism (glutamate dehydrogenase, 2-oxoglutarate dehydrogenase, and glutamate synthase) were affected by this mutation. Sequencing of the chromosomal locus bordering the Tn5 in P121R25 indicated the presence of the dnaK and dnaJ genes in an arrangement similar to that described in R. leguminosarum bv. viciae (GenBank accession number Y14649). The mutation was located in the dnaJ (hsp40) gene.


Asunto(s)
Fabaceae/microbiología , Genes Bacterianos , Proteínas de Choque Térmico/genética , Plantas Medicinales , Rhizobium leguminosarum/fisiología , Simbiosis , Mapeo Cromosómico , Ácido Glutámico/metabolismo , Proteínas del Choque Térmico HSP40 , Datos de Secuencia Molecular , Mutagénesis Insercional , Fijación del Nitrógeno
18.
Biol Psychiatry ; 54(7): 763-8, 2003 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-14512218

RESUMEN

We report two adult patients with succinic semialdehyde dehydrogenase deficiency, manifesting as gamma-hydroxybutyric aciduria. For both, the clinical presentation included significant behavioral disturbances and psychosis (hallucinations, disabling anxiety, aggressive behavior, and sleep disorder), leading to multiple therapeutic attempts. Intervention with benzodiazepines appeared most efficacious, resulting in decreased aggression and agitation and improvement in anxiety. A review of 56 published and unpublished studies of SSADH-deficient patients revealed that 42% manifested behavioral disturbances, whereas 13% (predominantly adults) displayed psychotic symptomatology. To explore the potential biochemical basis of these behavioral abnormalities, we studied cerebrospinal fluid derived from 13 patients, which revealed significantly elevated GHB (65- to 230-fold), high free and total GABA (up to threefold), and low glutamine. Although within the control range, homovanillic and 5-hydroxyindoleacetic acids (end products of dopamine and serotonin metabolism, respectively) showed a significant linear correlation with increasing GHB concentration, suggesting enhanced dopamine and serotonin turnover. We conclude that elevated GABA combined with low glutamine suggest disruption of the glial-neuronal glutamine/GABA/glutamate shuttle necessary for replenishment of neuronal neurotransmitters, whereas altered dopamine and serotonin metabolism may be causally linked to the hyperkinetic movement disorders and behavioral disturbances seen in SSADH-deficient patients.


Asunto(s)
Aldehído Oxidorreductasas/deficiencia , Errores Innatos del Metabolismo/psicología , Oxibato de Sodio/orina , Adulto , Aldehído Oxidorreductasas/líquido cefalorraquídeo , Atrofia/patología , Cerebelo/anatomía & histología , Cromatografía Líquida de Alta Presión , Cromatografía por Intercambio Iónico , Femenino , Globo Pálido/anatomía & histología , Ácido Glutámico/metabolismo , Alucinaciones , Ácido Homovanílico/líquido cefalorraquídeo , Humanos , Ácido Hidroxiindolacético/líquido cefalorraquídeo , Discapacidad Intelectual , Imagen por Resonancia Magnética/instrumentación , Imagen por Resonancia Magnética/métodos , Masculino , Errores Innatos del Metabolismo/líquido cefalorraquídeo , Errores Innatos del Metabolismo/fisiopatología , Estadística como Asunto , Succionato-Semialdehído Deshidrogenasa , Ácido gamma-Aminobutírico/metabolismo
19.
Gene ; 197(1-2): 343-51, 1997 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-9332384

RESUMEN

A genomic clone of RbcS was isolated from an alfalfa (Medicago sativa L. cv. Apica) genomic library and characterized. Although this clone has structural features similar to a functional gene, the second exon is interrupted by a stop codon and thus is not fully translatable in the plant. Sequence analysis of the 5' and 3' noncoding regions of RbcSK-1A showed a high sequence homology to the flanking sequences of the RbcS-3A gene from pea. The regions of homology contain many important cis-regulatory elements shown to be essential for regulation of the RbcS-3A gene in pea. The promoter of this alfalfa rubisco clone was used in a translational fusion to test its ability to control the expression of the GUS reporter gene in an homologous nuclear background. High levels of GUS enzyme activity were recorded. These strong levels are comparable to some exceptionally high levels produced in other studies following the use of photosynthesis gene promoters in fusions with the GUS reporter gene.


Asunto(s)
Medicago sativa/genética , Pisum sativum/genética , Regiones Promotoras Genéticas/genética , Ribulosa-Bifosfato Carboxilasa/genética , Homología de Secuencia de Ácido Nucleico , Secuencia de Bases , Clonación Molecular , Exones/genética , Dosificación de Gen , Regulación de la Expresión Génica de las Plantas/efectos de la radiación , Genes de Plantas/genética , Genes Reporteros/genética , Glucuronidasa/genética , Luz , Medicago sativa/enzimología , Datos de Secuencia Molecular , Plantas Modificadas Genéticamente , ARN Mensajero/análisis , ARN de Planta/análisis , Proteínas Recombinantes de Fusión , Mapeo Restrictivo , Análisis de Secuencia de ADN
20.
Neurology ; 45(10): 1837-40, 1995 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-7477978

RESUMEN

Neurologic sequelae may occur months to years after cranial irradiation. The site of primary damage is probably the vascular endothelium. Over a 2.8-year period, four children with brain tumors, a mean of 11 years of age at diagnosis (range, 6.5 to 15.5 years), had new onset of severe intermittent unilateral headaches associated with nausea, episodic visual loss, hemiparesis, aphasia, or hemisensory loss. The headaches lasted 2 to 24 hours. All patients had previously received whole-brain (2,400 to 3,600 cGy) and additional local boost (1,800 to 3,100 cGy) cranial irradiation, as well as cisplatin-, lomustine-, and vincristine-containing chemotherapy regimens. Symptoms began 1.2 to 2.8 years after the diagnosis, when all had stable disease and were off treatment. MRI studies were unchanged, and CSF cytology, EEGs, echocardiograms, and magnetic resonance angiograms were normal in all. Cerebral angiograms, performed in three children, were normal but led to severe headaches and neurologic deficits (hemiparesis in one and visual loss in two) that resolved after 24 to 48 hours. Response to antimigraine and antiplatelet medications was variable. We conclude that (1) "complicated migraine-like episodes" may occur in children after cranial irradiation and chemotherapy as a sequela of therapy; (2) these headaches may not be the harbinger of impending strokes, severe intracranial vasculitis, or tumor recurrence; and (3) while cerebral angiography may be useful in differential diagnosis, it may cause transient worsening of symptoms.


Asunto(s)
Antineoplásicos/efectos adversos , Neoplasias Encefálicas/terapia , Irradiación Craneana/efectos adversos , Trastornos Migrañosos/etiología , Adolescente , Niño , Femenino , Humanos , Masculino , Factores de Tiempo
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