Retrospective analysis and modifications of retractor systems for anterior odontoid screw fixation.

The authors present an in-depth retrospective analysis of retractor systems for anterior odontoid screw fixation. They discuss various modifications and innovations of such systems and describe their own tubular retractor system, in which a beveled end conformal to the ventral surface of the vertebral column at the C2-3 level is introduced together with an incorporated light source. This new retractor system allows optimal anatomical exposure for controlled odontoid screw placement with improved protection of surrounding vital structures.

The transcriptional activation domain of VP16 is required for efficient infection and establishment of latency by HSV-1 in the murine peripheral and central nervous systems.

The herpes simplex virus (HSV) transactivator VP16 is a structural component of the virion that activates immediate-early viral gene expression. The HSV-1 mutant in1814, which contains a 12-bp insertion that compromises the transcriptional function of VP16, replicated to a low level if at all in the trigeminal ganglia of mice (I. Steiner, J.

Toxicity and neuronal infection of a HSV-1 ICP34.5 mutant in nude mice.

HSV-1 mutants in the RL-1 gene encoding the ICP34.5 protein have been demonstrated to have diminished neurovirulence in brain yet replicate as efficiently as parental virus in transformed tissue culture cells. Thus they have been proposed as candidates viruses for human brain tumor therapies.

Hypertension, small size, and deep venous drainage are associated with risk of hemorrhagic presentation of cerebral arteriovenous malformations.

Objective: To identify clinical and angiographic factors of cerebral arteriovenous malformations (AVMs) associated with hemorrhage to improve the estimation of the risks and help guide management in clinical decision making.

Methods: We conducted a retrospective analysis of 100 consecutive adults who have presented during the past 3 years to our institution with cerebral AVMs. Angiographic and clinical parameters were evaluated using multivariate logistic regression analysis to analyze factors associated with hemorrhagic presentation.

A neuroattenuated ICP34.5-deficient herpes simplex virus type 1 replicates in ependymal cells of the murine central nervous system.

Herpes simplex virus type 1 (HSV-1) variant 1716 is deleted in the gene encoding ICP34.5 and is neuroattenuated after intracranial inoculation of mice. Although the mechanism of attenuation is unclear, this property has been exploited to eliminate experimental brain tumours.

Use of differential display reverse transcription-PCR to reveal cellular changes during stimuli that result in herpes simplex virus type 1 reactivation from latency: upregulation of immediate-early cellular response genes TIS7, interferon, and interferon regulatory factor-1.

The detailed mechanism which governs the choice between herpes simplex virus (HSV) latency and reactivation remains to be elucidated. It is probable that altered expression of cellular factors in sensory neurons leads to induction of HSV gene expression resulting in reactivation. As an approach to identify novel cellular genes which are activated or repressed by stimuli that reactivate HSV from latency and hence may play a role in viral reactivation, RNA from explanted trigeminal ganglia (TG) was analyzed by differential display reverse transcription-PCR (DDRT-PCR).

Clinical evaluation and management of aneurysmal subarachnoid hemorrhage.

As neuroradiologic techniques become more critical to the care of patients suffering from aneurysmal subarachnoid hemorrhage, a thorough understanding of the natural history and medical management of this disorder by neuroradiologists is required to insure appropriate diagnosis and therapy. This article addresses the medical and perioperative management of subarachnoid hemorrhage, with an emphasis on features relevant to neuroradiologic diagnosis and treatment.

Cigarette smoking-induced increase in the risk of symptomatic vasospasm after aneurysmal subarachnoid hemorrhage.

Vasospasm following aneurysmal subarachnoid hemorrhage (SAH) is correlated with the thickness of blood within the basal cisterns on the initial computerized tomography (CT) scan. To identify additional risk factors for symptomatic vasospasm, the authors performed a prospective analysis of 75 consecutively admitted patients who were treated for aneurysmal SAH. Five patients who died before treatment or were comatose postoperatively were excluded from the study.

Gene expression during reactivation of herpes simplex virus type 1 from latency in the peripheral nervous system is different from that during lytic infection of tissue cultures.

Herpes simplex virus (HSV) replicates in peripheral tissues and forms latent infections in neurons of the peripheral nervous system. It can be reactivated from latency by various stimuli to cause recurrent disease. During lytic infection in tissue culture cells, there is a well-described temporal pattern of (i) immediate-early, (ii) early, and (iii) late gene expression.

Multifocal noninfectious granulomatous encephalitis in a child. Case report.

This 9-year-old boy presented with a multifocal, apparently noninfectious granulomatous process involving the central nervous system. Despite gross-total excision of the large left temporal lesion, it recurred after surgery. Serological studies and cultures failed to demonstrate an infectious agent, and histopathological investigation showed a nonspecific granulomatous process without vasculitis.

Therapy of a murine model of pediatric brain tumors using a herpes simplex virus type-1 ICP34.5 mutant and demonstration of viral replication within the CNS.

To develop improved therapies for medulloblastoma, we studied the ability of a neuroattenuated HSV-1 ICP34.5 mutant (variant-1716) to replicate within and destory an authentic medulloblastoma cell line known as Med 283 (D283) using immunohistochemistry, in situ hybridization, and viral titrations. In vitro studies showed that variant-1716 replicates in and destroys monolayers of D283 cells with kinetics similar to wild-type strain 17+.

Lhermitte-Duclos disease and Cowden's syndrome in an adolescent patient. Case report.

Recent reports of seven cases of Lhermitte-Duclos disease occurring in adult patients with Cowden's syndrome (multiple hamartoma syndrome) strongly suggest that Lhermitte-Duclos disease is one of the types of neoplasia that characterize this syndrome. A case of Lhermitte-Duclos disease is reported in a 16-year-old girl with craniomegaly, choroidal hamartoma, and conjunctival papilloma of the right eye, and a history of bilateral multinodular adenomatous goiter and cystic hygroma. These findings strongly suggest a diagnosis of Cowden's syndrome.

Lesions of excitatory pathways reduce hippocampal cell death after transient forebrain ischemia in the gerbil.

Transient forebrain ischemia produces a spatially and temporally selective pattern of neuronal degeneration in the hippocampal formation of the Mongolian gerbil. Ischemic neuronal death has been suggested to depend on the activation of excitatory hippocampal pathways that project to the vulnerable neurons. This idea was tested by examining the effect of a unilateral entorhinal cortical lesion or a unilateral knife cut lesion of intrahippocampal pathways on the neuropathology produced by 5 min of complete forebrain ischemia.