Unilateral hydrocephalus in paediatric patients, a trial of endoscopic fenestration.
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Two uncommon cases of unilateral, asymmetrical hydrocephalus secondary to membranous occlusion of foramen of monro are described. Both the cases presented with clinical features of raised intracranial pressure and their cranial computerized scans (CT) revealed asymmetrical dilatation of lateral ventricles with displacement of septum pellucidum towards the side of smaller ventricle. Neuroendoscopic fenestration of septum pellucidum and foramen of monro was tried in both the cases, which remained successful in first, while the second case required unilateral ventriculoperitoneal shunt, due to failed endoscopic negotiation of narrowed foramen of monro and intraoperative bleeding during endoscopic intervention. (+info)
Developmental toxicity studies in rats and rabbits with 3,5,6-trichloro-2-pyridinol, the major metabolite of chlorpyrifos.
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3,5,6-Trichloro-2-pyridinol (TCP), the primary metabolite of chlorpyrifos and chlorpyrifos-methyl, was evaluated for potential developmental toxicity. Groups of 32-34 bred female Fischer 344 rats were given 0, 50, 100, or 150 mg TCP/kg/day by gavage on gestation days 6-15; the fetuses were evaluated on gestation day 21. Similarly, groups of 16 inseminated female New Zealand White rabbits were given 0, 25, 100, or 250 mg TCP/kg/day by gavage on gestation days 7-19, and fetuses were evaluated on gestation day 28. No clinical signs of toxicity attributed to TCP were noted in either species. In rats, at 150 mg/kg/day, maternal effects included slight decreases in feed consumption, significantly depressed body weight gain (25% relative to controls) resulting in significantly lower maternal terminal body weights, and increased relative liver weight. At 100 mg/kg/day, maternal body weight gain in rats was depressed approximately 22%. Among rabbits, maternal effects were limited to the group given 250 mg/kg/day, which lost an average of approximately 70 g during the treatment period (vs. 140 g in the controls). There were no effects on fetal weight or viability, nor were there significant increases in any fetal alteration in either species. A slightly higher (not statistically significant) than usual incidence of central nervous system anomalies occurred in rabbits, but these anomalies were found in both treated and control groups in this study as well as contemporaneous studies of unrelated compounds. This, and the fact that these anomalies were not seen with the parent compound, chlorpyrifos, suggest that their origin was spontaneous. Thus, TCP was not considered fetotoxic or teratogenic in either rats or rabbits, even at dose levels that produced maternal toxicity. (+info)
Fetal intracranial tumors detected by ultrasound: a report of two cases and review of the literature.
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Two cases of fetal intracranial tumors detected prenatally by ultrasound, together with a review of the literature on this rare disease, are presented. Sonographic features, histopathological type and location of the tumors, sex distribution, associated anomalies and overall prognosis are described as well as obstetric and postnatal therapeutic management. (+info)
Endoscopic aqueductal plasty via the fourth ventricle through the cerebellar hemisphere under navigating system guidance--technical note.
(28/1062)
A 1-year 8-month-old boy presented with isolated fourth ventricle after ventriculoperitoneal shunting for hydrocephalus associated with ventricular and subarachnoid hemorrhage. The therapeutic endoscope was inserted through the thin left cerebellar hemisphere. Endoscopic aqueductal plasty was performed via the enlarged fourth ventricle under guidance from a navigating system. Endoscopic aqueductal plasty via the fourth ventricle under navigating system guidance is a useful procedure enabling less invasive surgery for isolated fourth ventricle associated with slit-like ventricle after shunt placement. (+info)
Antibacterial activity of antibiotic-soaked polyvinylpyrrolidone-grafted silicon elastomer hydrocephalus shunts.
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If shunts, inserted for the relief of hydrocephalus, are pretreated with antimicrobials, the incidence of shunt-associated infections (SAI) may be reduced. The duration of the antibacterial activity of shunts, made from conventional silicon elastomer (SE) or from SE grafted with the hydrogel polyvinylpyrrolidone (SEpvp), which had been soaked in various antibiotics, was assessed in vitro. For any antibiotic or combination, using an arbitrary breakpoint (aBP), SEpvp remained antibacterially active for longer periods than SE. Bacterial adherence to either shunt was prevented during the period of antibacterial activity. Thus, the aBP is a good indicator of the capacity of antimicrobial-treated shunts to prevent bacterial colonization in vitro. Hydrogel-grafting of shunts may be useful in preventing SAI. (+info)
Endoscopic surgery for obstructive hydrocephalus.
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Endoscopic surgery is popular in the neurosurgical field. The purpose of this study was to determine the role of endoscopy in obstructive hydrocephalus. From 1989 to 1999, we performed 81 endoscopic third ventriculostomies and 10 septostomies. Seventy-one of 81 operations were performed with endoscopic third ventriculostomy alone and 10 patients had endoscopic third ventriculostomy and ventriculoperitoneal shunt simultaneously. Age distribution varied from 2 months to 62 years of age. Our selection criteria included aqueductal stenosis (39 patients) and obstructive hydrocephalus due to tumor or cyst (42 patients). The most common candidate for endoscopic septostomy was atresia of the foramen of Monro (4 patients). Endoscopic septostomy was also performed to simplify shunting in patient; with multiseptated ventricle due to shunt infection, germinoma, thalamic tumor, craniopharyngioma, cyst and brain abscess. Sixty-five of 71 patients who were treated with endoscopic third ventriculostomy alone showed successful results (91.5%). However, 6 patients had unsatisfactory results and they needed a ventriculoperitoneal shunt. With no mortality, transient surgical complications were observed in 7 patients: 2 transient diabetes insipidus from electrical injury to the pituitary stalk, 1 epidural hematoma from sudden drainage of CSF, 1 delayed intraventricular hemorrhage. 2 obstruction of fenestration site and 1 transient memory disturbance from injury to the fornix. Endoscopic septostomy was useful in simplifying shunting in all cases with complicated hydrocephalus. Endoscopic surgery is straightforward and effective in appropriately selected cases with obstructive by drocephalus. (+info)
A mouse model for glioma: biology, pathology, and therapeutic opportunities.
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The epidermal growth factor receptor (EGFR) gene is amplified or mutated in 30-50% of human glioblastoma multiforme. These mutations are usually associated with deletions of the INK4a-ARF locus, which encodes 2 gene products (p16INK4a and p19ARF) involved in cell cycle arrest and apoptosis. We have investigated the role of EGFR mutation in gliomagenesis using avian retroviral vectors to transfer a mutant EGFR gene to glial precursors and astrocytes in transgenic mice. These mice express tv-a, a gene encoding the retrovirus receptor TVA, which is under the control of brain cell type-specific promoters. We demonstrate that expression of a constitutively active, mutant form of EGFR in cells in the glial lineage can induce lesions with many similarities to human gliomas, including increased cell density, vascular proliferation, and immunohistochemical staining for glial fibrillary acidic protein (GFAP) and nestin. We also demonstrate that primary astrocytes cultured from transgenic mice expressing tv-a from the GFAP promoter are efficiently infected in culture, and such genetically modified cell cultures can be tumorigenic in nude mice. The combinations of genetic lesions (eg, mutated EGFR, INK4a-/-) leading to tumor formation in these 2 mouse systems are similar to those found in human gliomas. These genetically defined animal models for gliomas will allow for the testing of therapies that are targeted specifically at the gene products involved in the pathogenesis of gliomas. (+info)
Gene dosage affects the cardiac and brain phenotype in nonmuscle myosin II-B-depleted mice.
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Complete ablation of nonmuscle myosin heavy chain II-B (NMHC-B) in mice resulted in cardiac and brain defects that were lethal during embryonic development or on the day of birth. In this paper, we report on the generation of mice with decreased amounts of NMHC-B. First, we generated B(DeltaI)/B(DeltaI) mice by replacing a neural-specific alternative exon with the PGK-Neo cassette. This resulted in decreased amounts of NMHC-B in all tissues, including a decrease of 88% in the heart and 65% in the brain compared with B(+)/B(+) tissues. B(DeltaI)/B(DeltaI) mice developed cardiac myocyte hypertrophy between 7 months and 11 months of age, at which time they reexpressed the cardiac beta-MHC. Serial sections of B(DeltaI)/B(DeltaI) brains showed abnormalities in neural cell migration and adhesion in the ventricular wall. Crossing B(DeltaI)/B(DeltaI) with B(+)/B(-) mice generated B(DeltaI)/B(-) mice, which showed a further decrease of approximately 55% in NMHC-B in the heart and brain compared with B(DeltaI)/B(DeltaI) mice. Five of 8 B(DeltaI)/B(-) mice were born with a membranous ventricular septal defect. Moreover, 5 of 5 B(DeltaI)/B(-) mice developed myocyte hypertrophy by 1 month; B(DeltaI)/B(-) mice also reexpressed the cardiac beta-MHC. More than 60% of B(DeltaI)/B(-) mice developed overt hydrocephalus and showed more severe defects in neural cell migration and adhesion than did B(DeltaI)/B(DeltaI) mice. These data on B(DeltaI)/B(DeltaI) and B(DeltaI)/B(-) mice demonstrate a gene dosage effect of the amount of NMHC-B on the severity and time of onset of the defects in the heart and brain. (+info)