This article concerns the effects of learner control in computer-assisted instruction (CAI). After reviewing previous reviews of research on the topic, twenty-four studies of learner control were subjected to meta-analysis. The results of both the review and meta-analysis are equivocal. Several reviews indicate that learner control works less well with younger, less able students. Other reviews indicate that, given optimal conditions, learner control can work with any students. The meta-analysis, however, yielded an average effect size that was small and negative suggesting that the average student would be slightly better off without it. Although learner control has theoretical appeal, its effects on learning seem neither powerful nor consistent.

These results indicate that adenosine is a major component of the biochemical changes that occur after retinal ischemia. Long-lasting increases in xanthine concentration during reperfusion after ischemia could be a source of oxygen free radicals that may contribute to delayed injury of the retina, attempts to decrease xanthine concentration would ideally be initiated within one hour after the end of ischemia.

Based on a proposed pathophysiology of slit ventricle syndrome (SVS), we have hypothesized that lumboperitoneal shunting exerts effects in SVS patients by increasing the buffering capacity for raised intracranial pressure (ICP) via an increase in cerebrospinal fluid drainage from the cerebral subarachnoid space (SAS). We describe 3 SVS patients with patent lumbar subarachnoid drainage but under-functioning ventriculoperitoneal shunts (VPS) who presented with ventriculomegaly (not SVS), and persistence of shunt malfunction like symptoms. Revision of the VPS resulted in complete resolution of symptoms despite a finding of low pressure in the ventricular space. This supports the hypothesis that lumboperitoneal shunting preferentially drains the SAS over the intraventricular space and in these cases allows the ‘SVS’ ventricles to enlarge by creating a pressure gradient from ventricles to SAS through the cortical mantle.

Traditional therapies for the treatment of malignant glioma have failed to make appreciable gains regarding patient outcome in the last decade. Therefore, immunotherapeutic approaches have become increasingly popular in the treatment of this cancer. This article reviews general immunology of the central nervous system and the immunobiology of malignant glioma to provide a foundation for understanding the rationale behind current glioma immunotherapies. A review of currently implemented immunological treatments is then provided with special attention paid to the use of vaccines, gene therapy, cytokines, dendritic cells and viruses. Insights into future and developing avenues of glioma immunotherapy, such as novel delivery systems, are also discussed.

Optimal treatment for hydrocephalus related to Dandy-Walker syndrome (DWS) remains elusive. Patients with DWS-related hydrocephalus often require combinations of shunting systems to effectively drain both the supratentorial ventricles and posterior fossa cyst. We describe an endoscopic technique, whereby a frontally placed, single-catheter shunting system effectively drained the supratentorial and infratentorial compartments. This reduces the complexity and potential risk associated with the combined shunting systems required by so many with DWS-related hydrocephalus.