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George Jallo

Publications and source records attributed to George Jallo.

6 recordsLinked to original sources
PubMed2006

Adjustable vs set-pressure valves decrease the risk of proximal shunt obstruction in the treatment of pediatric hydrocephalus.

INTRODUCTION: The use of programmable shunt valves has increased dramatically in the practice of pediatric hydrocephalus. Despite theoretical advantages, it remains unclear if the use of programmable vs set-pressure valves affects shunt outcome. MATERIALS AND METHODS: The clinical and radiological records of all pediatric patients undergoing ventriculoperitoneal (VP), ventriculopleural (VPl), and ventriculoatrial (VA) shunt surgery from 2001 to 2004 at an academic institution were reviewed. The association of programmable vs set-pressure valves with subsequent shunt revision was assessed by Kaplan-Meier shunt survival plots and log-rank analysis. RESULTS: A total of 279 VP, VPl, and VA shunt surgeries were performed on patients with median (interquartile range) age of 4 (1-14) years (161 male, 118 female; 158 communicating, 122 obstructive hydrocephalus). Programmable valves were used in 76 (27%) cases and set-pressure valves in 203 (73%). At mean+/-SD follow-up of 17 +/- 13 months, programmable vs set-pressure valves were associated with reduced risk of both overall shunt revision [26 (35%) vs 109 (54%); relative risk (RR) (95% CI); 0.61 (0.41-0.91), p = 0.016] and proximal obstruction [9 (12%) vs 58 (28%); RR (95% CI); 0.39 (0.27-0.80), p = 0.006]. There was no difference in distal obstruction [3 (4%) vs 11 (5%) cases], infection [6 (8%) vs 12 (6%) cases], valve obstruction [0 (0%) vs 4 (2%)], or shunt disconnection [2 (3%) vs 1 (1%)] between adjustable and set-pressure valves, respectively. CONCLUSION: In our experience, the use of programmable vales was associated with a decreased risk of proximal shunt obstruction and shunt revision. Programmable valves may be preferred in patients frequently experiencing proximal shunt failure. A prospective, controlled study is warranted to evaluate the potential value of adjustable vs set-pressure valve systems.

Adolescent↗
PubMed2006

Brainstem gliomas.

Explore the source record for details and available documents.

Brain Stem Neoplasms↗
PubMed2006

A novel model of intramedullary spinal cord tumors in rats: functional progression and histopathological characterization.

OBJECTIVE: Intramedullary spinal cord tumors are difficult lesions to treat given their recurrence rate and limited treatment options. The absence of an adequate animal model, however, has hindered the development of new treatment paradigms. In this study, we describe the technique for intramedullary injection of two experimental rodent gliomas (9L and F98) and present the methodology for functional and histopathological analysis of tumor progression. METHODS: F344 rats (n = 24) were randomized into three groups. Group 1 (n = 8) received a 5 microl intramedullary injection of Dulbecco's modified Eagle medium, Group 2 received a 5 microl intramedullary injection of 9L gliosarcoma (100,000) cells, and Group 3 received a 5 microl intramedullary injection of F98 glioma (100,000) cells. The animals were anesthetized, a 2 cm incision was made in the dorsal mid-thoracic region, and the spinous process of the T5 vertebrae was removed to expose the intervertebral space. The ligamentum flavum was removed, and an intramedullary injection was made into the spinal cord. The animals were evaluated daily for signs of paralysis using the Basso, Beattie, and Bresnahan scale and sacrificed after the onset of deficits for histopathological analysis. RESULTS: Animals injected with 9L-gliosarcoma had a median onset of hind limb paresis at 12 +/- 2.9 days. Animals injected with F98 glioma had a median onset of hind limb paresis at 19 +/- 3 days. Animals injected with Dulbecco's modified Eagle medium did not show neurological deficits. Hematoxylin-eosin cross sections confirmed the presence of intramedullary 9L and F98 tumor invading the spinal cord. Control animals had no significant histopathological findings. CONCLUSION: Animals injected with 9L or F98 consistently developed hind limb paresis in a reliable and reproducible manner. The progression of neurological deficits is similar to that seen in patients with intramedullary spinal cord tumors. These findings suggest that this model mimics the behavior of intramedullary spinal cord tumors in humans and may be used to examine the efficacy of new treatment options for both low- and high-grade intramedullary tumors.

Animals↗
PubMed2005

Diagnosis and management of vein of galen aneurysmal malformations.

Vein of Galen aneurysmal malformations (VGAM) are rare intracranial vascular anomalies typically found in children. The anatomic landmark of a VGAM is the presence of multiple arteriovenous shunts draining into a dilated median prosencephalic vein, an embryonic vessel normally absent at the adult stage. This article reviews the developmental anatomy, the clinical presentation, and the current management of VGAM.

Bioethical Issues↗
PubMed2005

A novel intramedullary spinal cord tumor model: functional, radiological, and histopathological characterization.

OBJECT: Survival rates for high-grade intramedullary spinal cord tumors (IMSCTs) are approximately 30%, and optimal therapy has yet to be determined. Development of a satisfactory intramedullary tumor model is necessary for testing new therapeutic paradigms that may prolong survival. The authors report the technique, functional progression, radiological appearance, and histopathological features of a novel intramedullary model in rabbits. METHODS: Ten New Zealand white rabbits were randomized to receive an intramedullary injection of either 25 microl of VX2 carcinoma cells (500,000 cells; six rabbits) or 25 microl of medium (Dulbecco modified Eagle medium; four rabbits) into the midthoracic spinal cord. Postoperatively the rabbits were evaluated twice daily for neurological deficits. High-resolution magnetic resonance (MR) images were acquired preoperatively and weekly postoperatively until onset of paraparesis, at which point the animals were killed, and the midthoracic spines were processed for histopathological examination. The VX2-carcinoma cells grew in 100% of animals injected and resulted in a statistically significant mean onset of paraparesis of 16.8 +/- 1.7 days (p = 0.0035, log-rank test), compared with animals in the control group in which neurological deficits were absent by Day 45. Contrast-enhanced T1-weighted MR imaging best demonstrated space-occupying intramedullary lesions and histopathological findings confirmed the intramedullary location of the tumor. Animals in the control group exhibited no functional, radiographic, or pathological signs of tumor. CONCLUSIONS: Progression to paraparesis was consistent in all the VX2-injected animals, with predictable onset of paraparesis occurring approximately 17 days postinjection. Histopathological and radiological characteristics of the VX2 intramedullary tumor are comparable with those of aggressive primary human IMSCTs. Establishment of this novel animal tumor model will facilitate the testing of new therapeutic paradigms for the treatment of IMSCTs.

Animals↗