Effects of Pontine Lesions on REM Sleep

Chiasmal dysfunction produces a characteristic clinical picture, regardless of the mechanism. In most cases a compressive lesion is the cause. In occasional cases, however, no such extrinsic mass is found and other possible etiologies must be explored. In some of these cases, the pathologic process is identifiable with appropriate neuroimaging. For example, inflammation, infiltrative tumors, and radiation necrosis produce intrinsic chiasmal enhancement. Chiasmal ischemia may require specialized magnetic resonance (MR) sequences for diagnosis. Chiasmal hemorrhage, trauma and chiasmal herniation typically produce distinctive changes on noncontrasted imaging. In cases of metabolic insult, either toxic or hereditary, radiographic changes are typically absent. In each of these, the correct diagnosis can usually be made with a combination of clinical and radiographic features.     

Assessing Internet Addiction Using the Parsimonious Internet Addiction Components Model—A Preliminary Study

Internet usage has grown exponentially over the last decade. Research indicates that excessive Internet use can lead to symptoms associated with addiction. To date, assessment of potential Internet addiction has varied regarding populations studied and instruments used, making reliable prevalence estimations difficult. To overcome the present problems a preliminary study was conducted testing a parsimonious Internet addiction components model based on Griffiths’ addiction components (Journal of Substance Use, 10, 191–197, 2005), including salience, mood modification, tolerance, withdrawal, conflict, and relapse. Two validated measures of Internet addiction were used (Compulsive Internet Use Scale [CIUS], Meerkerk et al. in Cyberpsychology & Behavior, 12(1), 1–6, 2009, and Assessment for Internet and Computer Game Addiction Scale [AICA-S], Wölfling et al. 2010) in two independent samples (ns?=?3,105 and 2,257). The fit of the model was analysed using Confirmatory Factor Analysis. Results indicate that the Internet addiction components model fits the data in both samples well. The two sample/two instrument approach provides converging evidence concerning the degree to which the components model can organize the self-reported behavioural components of Internet addiction. Recommendations for future research include a more detailed assessment of tolerance as addiction component.     

Using the BOLD MR signal to differentiate the stereoisomers of ketamine in the rat

RATIONALE: Ketamine is a chiral molecule that is reported to model aspects of schizophrenia. OBJECTIVES: To investigate the stereospecificity of the isomers of ketamine using pharmacological magnetic resonance imaging (phMRI) in order to further understand ketamine's pharmacodynamic actions. METHOD: Responses to 25 mg kg-1S(+) isomer, R(-) isomer and racemic ketamine in independent groups of Sprague-Dawley rats were investigated using a prepulse inhibition paradigm, locomotor observations, MRI and 2-deoxyglucose techniques. RESULTS: Racemic ketamine and the S(+) isomer were both capable of disrupting sensorimotor gating as measured using prepulse inhibition and produced a longer period of hyperlocomotion comparative to the R(-) isomer. In contrast, large alterations in the BOLD MR signal were observed with R(-) isomer, whereas S(+) isomer and racemate precipitated more localized BOLD signal changes predominantly in cortical, hippocampal and hindbrain regions. Glucose utilization rates in conscious animals are in agreement with previously published data and verify the BOLD responses in the racemic group. However, no significant changes in glucose utilization were observed in the anesthetized cohort. CONCLUSIONS: Ketamine and its isomers have stereospecific effects on sensorimotor gating and locomotion that correlate with the enantiomer's affinity for the NMDA receptor. It would appear that anesthesia, as required for preclinical MRI procedures, may interact with and potentially attenuate the drug's response. Although analysis of the main effect of isomers in comparison to each other or the racemate offers an alternative analysis method that should be less susceptible to anesthetic interactions, only the R(-) isomer comparative to the racemate offers significant differences of interest.     

Nonredundant roles of antibody,cytokines, and perforin in the eradication of established Her-2/neu carcinomas

Since the mechanisms by which specific immunity destroys Her-2/neu carcinoma cells are highly undetermined, these were assessed in BALB/c mice vaccinated with plasmids encoding extracellular and transmembrane domains of the protein product (p185(neu)) of the rat Her-2/neu oncogene shot into the skin by gene gun. Vaccinated mice rejected a lethal challenge of TUBO carcinoma cells expressing p185(neu). Depletion of CD4 T cells during immunization abolished the protection, while depletion of CD8 cells during the effector phase halved it, and depletion of polymorphonuclear granulocytes abolished all protection. By contrast, Ig mu-chain gene KO mice, as well as Fcgamma receptor I/III, beta-2 microglobulin, CD1, monocyte chemoattractant protein 1 (MCP1), IFN-gamma, and perforin gene KO mice were protected. Only mice with both IFN-gamma and perforin gene KOs were not protected. Although immunization also cured all BALB/c mice bearing established TUBO carcinomas, it did not cure any of the perforin KO or perforin and IFN-gamma KO mice. Few mice were cured that had knockouts of the gene for Ig mu-chain, Fcgamma receptor I/III, IFN-gamma, or beta-2 microglobulin. Moreover, vaccination cured half of the CD1 and the majority of the MCP1 KO mice. The eradication of established p185(neu) carcinomas involves distinct mechanisms, each endowed with a different curative potential.     

Diagnosis of sacroiliac joint pain: validity of individual provocation tests and composites of tests

Previous research indicates that physical examination cannot diagnose sacroiliac joint (SIJ) pathology. Earlier studies have not reported sensitivities and specificities of composites of provocation tests known to have acceptable inter-examiner reliability. This study examined the diagnostic power of pain provocation SIJ tests singly and in various combinations, in relation to an accepted criterion standard. In a blinded criterion-related validity design, 48 patients were examined by physiotherapists using pain provocation SIJ tests and received an injection of local anaesthetic into the SIJ. The tests were evaluated singly and in various combinations (composites) for diagnostic power. All patients with a positive response to diagnostic injection reported pain with at least one SIJ test. Sensitivity and specificity for three or more of six positive SIJ tests were 94% and 78%, respectively. Receiver operator characteristic curves and areas under the curve were constructed for various composites. The greatest area under the curve for any two of the best four tests was 0.842. In conclusion, composites of provocation SIJ tests are of value in clinical diagnosis of symptomatic SIJ. Three or more out of six tests or any two of four selected tests have the best predictive power in relation to results of intra-articular anaesthetic block injections. When all six provocation tests do not provoke familiar pain, the SIJ can be ruled out as a source of current LBP.     

Evaluation of a web-based palliative care pain management module for housestaff

The objectives of this study were to determine internal medicine residents' knowledge of outpatient palliative care pain management, describe the association of level of training with knowledge, and evaluate the impact on knowledge of a web-based, interactive, evidence-based educational module. We developed the module using established educational principles, based on review of other educational materials, guidelines, and the medical literature. The module included pretest and post-test questions, case studies, didactic sections, and web links. Six hundred twelve housestaff in 35 training programs in 19 states completed the module during the 2005–2006 academic year (196 [32.0%] postgraduate year [PGY]-1, 200 [32.7%] PGY-2, and 216 [35.3%] PGY-3). The mean pretest score was 54.4% (range 31.1%–84.6%); scores were lowest for specific pain management knowledge questions, including appropriate titration of breakthrough opioid doses (mean 31.1% correct) and appropriate initial use of opioids (40.7% correct). Pretest scores were not significantly different by level of training (52.2% for PGY-1 and 56.7% for PGY-3). The mean post-test score was 72.8%, a statistically significant increase from the pretest overall (P < 0.001) and for seven of the 10 learning objectives (P < 0.001). These findings indicate that housestaff lacked knowledge in many areas of palliative care pain management, and knowledge did not increase with time spent in residency. The large increase in test scores after the module suggests that this may be an effective component of a comprehensive palliative care curriculum.     

The effects of additive solution pH and metabolic rejuvenation on anaerobic storage of red cells

BACKGROUND: Red cell (RBC) storage can be extended to 9 weeks under anaerobic or alkaline conditions. Simultaneous use of these approaches has not provided additive benefit. Our objective was to determine whether anaerobic storage with acidified additive solution (AS) coupled with metabolic rejuvenation might further improve the benefits of anaerobic storage. STUDY DESIGN AND METHODS: RBC storage in AS with a pH value of 6.5, 7.4, or 8.3 in aerobic or anaerobic conditions was examined using a panel of in vitro biochemical and RBC markers. RBC rejuvenation during cold storage was also evaluated. A randomized crossover radiolabeled recovery study (eight subjects) evaluated anaerobic RBC storage using AS65 with cold rejuvenation for up to 16 weeks of storage. RESULTS: Adenosine triphosphate (ATP) and diphosphoglycerate acid (DPG) were better maintained in anaerobic storage than in aerobic storage. Acidic or neutral AS preserved ATP concentration better, while a neutral or basic pH AS favored maintenance of DPG levels at higher levels for a longer period. AS pH had less of an effect on exposure of phosphatidylserine (PS), vesicle protein release, and hemolysis. Rejuvenation of RBCs during cold, anaerobic storage resulted in increases in ATP and DPG levels and a reversal of PS exposure. Anaerobic storage of RBCs in pH 6.5 AS rejuvenated at 7 weeks of storage yielded RBC 24‐hour recoveries of 77.3 ± 12.5 percent after 10 weeks' storage time. After a second rejuvenation at Week 11, six subjects' units demonstrated a recovery of 75.9 ± 7.3 percent at 12 weeks of storage. CONCLUSION: Extended RBC storage may be achieved using anaerobic conditions combined with low‐pH AS and rejuvenation during storage.