The Severity of Dependence Scale (SDS) in an adolescent population of cannabis users: reliability, validity and diagnostic cut-off

The Severity of Dependence Scale (SDS) is a five-item scale that has been reported to be a reliable and valid screening instrument for dependence and a measure of dependence severity in adults across several substance classes. To date no data have been reported on its performance in a population of adolescent cannabis users. The current study assessed the psychometric properties of the SDS in a community sample of 14-18-year-old adolescent cannabis users (n=100). Internal consistency (alpha=0.83) and test-retest coefficients (ICC=0.88) were high and a principal components analysis of the scale found all items to load on a single factor. Total SDS score correlated significantly with frequency of cannabis use and number of DSM-IV dependence criteria met, indicating good concurrent validity. Receiver Operating Characteristic curve analysis was used to determine the most appropriate SDS cut-off score for use as an indicator of cannabis dependence, with optimal discrimination at an SDS score of 4. These findings indicate that the SDS is a reliable and valid measure of severity of cannabis dependence among adolescents, has high diagnostic utility, and that an SDS score of 4 may be indicative of cannabis dependence.     

Bilateral occlusion of vertebral artery: clinical patterns and long-term prognosis

We studied 17 patients with atherosclerotic bilateral occlusion of vertebral arteries (VA) identified by angiography. Seven had vertebrobasilar TIAs, eight a brainstem stroke (severe in two), and two had only carotid symptoms. Brainstem strokes were more frequent with bilateral intracranial occlusion (60%) than with at least one extracranial occlusion (28.6%), but long-term prognosis did not differ in these two groups. In follow-up, the mortality rate was 4.5% per year, and the stroke rate was 1.8% per year. Major functional disability was seen in 16.7% of the survivors. Bilateral distal VA occlusion may sometimes have a better prognosis than previously assumed. These findings raise doubts about the value of extra-intracranial surgical bypass procedures in patients with these lesions.     

Splenic "disappearance" during gated exercise nuclear angiocardiography

Decreasing splenic activity occurred during the maximum exercise phase of gated stress testing in 24 patients who underwent 26 such studies. This event was related to increasing exercise, and correlated with the relative increase in heart rate, pulse-pressure product, and cardiac output, but not ejection fraction. A multiple linear regression analysis showed that the combination of increases in pulse-pressure product and cardiac output had the best correlation with decreasing splenic activity at the conclusion of exercise. Redistribution of cardiac output toward muscle and away from splanchnic viscera is a consequence of exercise, and is graphically demonstrated by decreasing splenic visualization, which in some patients was so marked as to result in disappearance of the organ from the video monitor.     

Interferon-gamma can remain on the cell surface during the induction of the antiviral state.

The antiviral activity of cell-associated, non-elutable recombinant human gamma interferon (rHuIFN-gamma) was neutralized by antibody. The neutralization of cell-associated rHuIFN-gamma was maximal through 2 h (60-100%) and declined through 8 h (20-40%). Concomitantly, the antiviral activity of cell-associated [Met-Gln-Asp-Pro]-rHuIFN-gamma was sensitive to trypsin digestion over the same time period. However, the cell-associated antiviral activity of [Cys-Tyr-Cys]-rHuIFN-gamma remained sensitive to trypsin through 8 h. Neutralization of cell-associated rHuIFN-gamma by antibodies to the N-terminal end of HuIFN-gamma suggests that the N-terminal end(s) of cell-associated rHuIFN-gamma is directed outward from the receptor. Further, immunoprecipitation of radio-labelled rHuIFN-gamma by antibody alone suggests that biologically active rHuIFN-gamma is an oligomer. Taken together, these studies suggest that neutralization of cell-associated rHuIFN-gamma is probably due to divalent binding of antibody to or between rHuIFN-gamma in receptors on the cell surface. Also, our studies indicate that rHuIFN-gamma can remain associated with the cell surface during the induction of the antiviral state (AVS) and that binding of antibody to cell-associated rHuIFN-gamma inhibits the molecular events responsible for induction of the AVS.     

Mesial Temporal Sclerosis: Pathogenesis, Diagnosis, and Management

Summary: Mesial temporal sclerosis (MTS) is probably the most common symptomatic pathologic entity–alone or mixed with other pathologic features–for seizures of temporal lobe origin. The pathophysiology of MTS, including any genetic influence, needs clarification. A characteristic ictal expression for seizures of MTS origin appears not to exist. The majority of patients (78%) with postresection MTS who are seizure-free have tightly localized interictal abnormalities restricted to F7/F8, Spl/Sp2, T3/T4, and T5/T6 more than 96% of the time.
MRI abnormalities may be seen in 55% of patients with MTS if both "hard" and "soft" criteria are used or in 20% when only "hard" criteria are used. The neuropsychologic evaluation of patients with MTS, which includes intracarotid amobarbital test (IAT), may prove to be increasingly useful in identifying patterns of cognitive deficit that correlate with enhancement of both lateral-izing and localizing preoperative information.     

From educational philosophy to educational practice: fidelity and the curriculum in context

As part of a higher degree on research methods, exploratory work was undertaken concerning educational philosophy and educational practice using an ethnographic approach. This author discusses, using this exploratory work, the difficulties of attempting fidelity to an educational philosophy, through curriculum practice. Schools of nursing are increasingly adopting a rational approach to education, without considering the wider social context within which education occurs. The attempt to establish and pursue a single philosophy, ignores the plurality of ideological commitments held by nurse teachers. Further research is proposed using naturalistic methods in order to understand the processes of interpretation and implementation of educational philosophy.     

Interhemispheric transfer in patients with incomplete section of the corpus callosum. Anatomic verification with magnetic resonance imaging

Tests of interhemispheric disconnection including visual, somesthetic, kinesthetic, auditory, and complex motor functions were performed on seven patients with chronic epilepsy who had undergone partial surgical section of the corpus callosum, verified by magnetic resonance imaging. Two patients with only one third of the splenium remaining demonstrated disconnection syndromes involving all modalities except vision, which was completely intact. Five patients had lesions involving the rostrum and the anterior two thirds to four fifths of the body of the callosum, with the splenium spared. They demonstrated little evidence of disconnection in the modalities indicated, except for left ear suppression on a dichotic listening task and partial somatosensory disruption in some cases. These results emphasize the importance of the posterior corpus callosum for interhemispheric sensory and sensorimotor transfer, although some discrepancies between current behavioral data and previous anatomic findings remain.