Biomedical subjects

Sergio Cavalheiro

Publications and source records attributed to Sergio Cavalheiro.

8 recordsLinked to original sources

PubMed2006

Metaphase and array comparative genomic hybridization: unique copy number changes and gene amplification of medulloblastomas in South America.

Tumors of the central nervous system are the second most frequent malignancy of childhood, accounting for the majority of cancer-related deaths in this age group. Among these tumors, medulloblastomas (MB) remain in need of further genomic characterization toward understanding of pathogenesis and outcome predictors. Eight pediatric embryonal brain tumors were analyzed: five MB (one being desmoplastic), one PNET, one medulloepithelioma, and one ependymoblastoma. Analyses identified genomic imbalances, including the gain of 16p and the nonsyntenic coamplification of MYCN and TERT loci. More detailed FISH analysis showed that coamplification of MYCN and TERT in one of the MBs manifested as dispersed nuclear speckling, consistent with the presence of double minute chromosomes. There was considerable cell-to-cell copy number heterogeneity present, but it was clear that both genes were amplified concordantly. The amplification of oncogenes seems to play an important role in the pathogenesis of MB, and the association between MYCN and TERT amplifications and poor prognosis has not been well recognized. The uncharacteristic pattern of genomic imbalances detected in MB tumors may be a reflection of the characteristics of these tumors occurring in South America.

Adolescent↗

PubMed2006

Pre-surgical evaluation and surgical treatment in children with extratemporal epilepsy.

INTRODUCTION: This review summarizes some patterns of pre-surgical evaluation and surgical treatment of extratemporal epilepsy in pediatric patients with medically refractory seizures, whose ictal behavior is variable. The most effective treatment for intractable partial epilepsy is a focal cortical resection with excision of the epileptogenic zone (the area of ictal onset and initial seizure propagation). This might be risky, though, in the case of a widespread lesion, sometimes encroaching one or more lobes, given the risk to the functional cerebral cortex. An anterior temporal lobectomy might prove more effective then in preventing seizures with fewer potential complications. If partial extratemporal epilepsy is associated with pharmaco-resistant seizures, the preoperative evaluation and operative strategy are determined according to the epileptogenic zone and to the relationship between a substrate-directed disorder and eloquent areas. The pediatric treatment of extratemporal epilepsy is aimed at controlling the seizures, avoiding morbidity, and improving the patient's quality of life through psychosocial integration. Since the immature brain is more plastic than when mature, the recovery of functions after surgery is greater in children than in adults. RECOMMENDATION: Early surgery is recommended for children with intractable epilepsy, and is now accepted as an important therapeutic modality also for children with chronic epilepsy. CONCLUSION: Technological advances in the last two decades, mainly in neuroimaging, have led many medical centers to consider surgical treatment of epilepsy, accuracy being granted by MRI-based neuronavigation systems-an interface between the lesion seen in the preoperative magnetic resonance imaging (MRI) and the operative field, often invisible to the surgeon.

Electroencephalography↗

PubMed2004

Endoscopic third ventriculostomy in children younger than 1 year of age.

OBJECT: The authors analyzed data obtained in 36 patients younger than 1 year of age who were treated with endoscopic third ventriculostomy (ETV) for obstructive hydrocephalus at their institution. METHODS: There were 17 boys and 19 girls who ranged in age from 3 days to 11 months (mean 4.7 months). The causes of the hydrocephalus were Chiari Type II malformation (11 cases), aqueductal stenosis (11 cases), and other (14 cases). The success rate was 64% (p < 0.05, confidence interval 0.48-0.8) and there were four complications, mainly meningitis. The follow-up period ranged from 22 to 69 months (mean 47.4 months). CONCLUSIONS: Based on the 64% success rate in children younger than 1 year of age, ETV should be the treatment of choice for obstructive hydrocephalus in this age group, although larger studies involving specific causes of hydrocephalus are needed.

Endoscopy↗

PubMed2004

Comparative genomic hybridization analysis of pediatric adamantinomatous craniopharyngiomas and a review of the literature.

OBJECT: The purpose of this study was to examine chromosomal gains and losses in 11 pediatric adamantinomatous craniopharyngiomas by using comparative genomic hybridization (CGH), as well as to review the cytogenetic literature that has contributed to the characterization of these tumors. One source of confusion in the cytogenetic and CGH literature concerning craniopharyngioma is that the authors of most studies fail to distinguish between pediatric and later-onset forms of the disease. Thus, this study was focused on pediatric craniopharyngioma. METHODS: To determine an overview of the genetic events leading to the development of these tumors, 10 adamantinomatous craniopharyngiomas were analyzed using CGH; none of the tumor specimens demonstrated gains or losses of DNA sequence. CONCLUSIONS: In view of these findings as well as those published in the majority of previous cytogenetic studies of craniopharyngiomas, the authors conclude that the recurrent acquisition of chromosomal imbalances does not play a major role in tumorigenesis and that chromosomal gains and losses are a relatively rare event in primary tumors of pediatric origin.

Adolescent↗

PubMed2003

Fetal brain tumors.

INTRODUCTION: Fetal intracranial tumors are rare and their evolution is usually poor. With routine use of antenatal ultrasound imaging, a larger number of such tumors have been diagnosed. METHODS: During the period from January 1992 to January 2002, 18 cases diagnosed as intracranial tumors in the fetal stage were treated in the Neurosurgery and Obstetrics Departments of the Federal University of São Paulo and in the Fetal Medicine Service of the Maternity Hospital Santa Joana. RESULTS: The tumors most frequently found were those of the choroid plexus and teratomas. Out of those 18 cases, 11 patients presented with fetal hydrocephalus, and 5 of them, who were less than 34 weeks old (gestational age), underwent repeated cephalocenteses while awaiting better conditions for delivery. Two fetuses died while in utero before any intervention had taken place and 16 underwent craniotomy after birth. Twelve of those patients are still alive, 9 of whom are considered normal. The 3 others are slightly or moderately retarded.

Amniocentesis↗

PubMed2003

Fetal hydrocephalus--prenatal treatment.

PATIENTS AND METHODS: From January 1986 to January 2001, 85 cases of hydrocephalus were referred to the Pediatric Neurosurgery and Fetal Medicine Sections of the São Paulo Federal University and the Santa Joana Maternity Hospital in São Paulo, Brazil. Thirty-nine of these cases concerned fetuses ranging from 24 to 32 weeks' gestation, who underwent intrauterine treatment. The hydrocephalus etiologies consisted of: aqueduct stenosis (18 cases), intraventricular hemorrhage (8 cases), Dandy-Walker malformation (4 cases), Chiari type II (4 cases), and other diverse etiologies (5 cases). Twenty fetuses underwent repeated cephalocentesis: 18 received a ventriculo-amniotic shunt and in 1 case endoscopic third ventriculostomy was performed. The follow-up period varied between 1 and 14 years (median 5 years). Out of 39 patients, 26 have been considered as normal (IQ above 70), 6 have mild or moderate handicaps (IQ from 35 to 70), and 7 are severely handicapped (IQ below 35). After birth, 38 patients underwent ventriculoperitoneal shunting with low-pressure valves. CONCLUSION: In the absence of chromosomopathies, when the gestational age ranges between 24 and 32 weeks, progressive fetal hydrocephalus of a non-infectious origin can obtain benefit from intraventricular decompression performed during the fetal period. New methods of diagnosis and treatment should be developed, especially in those countries where interruption of gestation is not permitted by law, for the benefit of those families who, due to social or religious factors, do not accept abortion.

Adolescent↗

PubMed2003

Cervical epidural haematoma with clivus fracture: case report.

Clivus fractures are rare and severe entities, usually associated with vascular or cranial nerve lesions and frequently diagnosed postmortem. Cervical epidural haematomas can be traumatic or spontaneous, manifested in acute or chronic form, and are treated surgically in the majority of cases, although the conservative treatment also can be indicated to patients with incomplete and non-progressive deficits. The authors report the case of a female patient, 8 years old, victim of trampling in public way by a high velocity motorized vehicle, admitted in Glasgow 7, anisocoric pupils (left pupil midriatic), whose radiological investigation showed a transverse fracture of the clivus, cervical epidural haematoma and diffuse axonal injury. The patient was submitted to intracranial pressure monitorization, sedation and conservative treatment with dexamethasone, with good outcome. The authors also present a literature review.

Accidents, Traffic↗

PubMed2002

Fetal meningeal hemangiopericytoma. Case report.

The authors present the case of a 34-week-old fetus with a meningeal hemangiopericytoma that was diagnosed in utero by using abdominal magnetic resonance imaging. After birth, the neonate underwent transfontanelle ultrasonography and computerized tomography scanning of the head, which confirmed the presence of an extradural hyperdense lesion. Six hours after birth the neonate underwent a craniotomy, which resulted in complete resection of the mass. The postoperative period was uneventful and the newborn was discharged 7 days later. At 2-year follow-up examination there was no evidence of recurrence of the lesion. The authors have found no mention in the literature of this entity diagnosed in the prenatal period.

Adult↗