Endothelium-dependent relaxation and vasospasm in the single-hemorrhage canine model

Abstract

We have investigated the relationship between angiographic vasospasm and the ability of spastic vessels to relax in response to agents which promote release of endothelium derived relaxing factor. Vasospasm was induced in dogs by the 'single hemorrhage' technique. Animals received a single intracisternal injection of blood, blood activated with thromboplastin or collagen, or inert material, and angiograms were obtained day 0 and day 7. Vasospasm was estimated by measuring the ratio of the diameter of the vessel before and after treatment. Rings of cerebral artery obtained from these animals were suspended in a standard organ- bath arrangement, contracted with prostaglandin F2(X and then treated with increasing doses of adenosine triphosphate or bradykinin, both of which cause relaxation by an endothelium-dependent process. The arteries from animals with moderate to severe vasospasm showed a response to bradykinin and adenosine- triphosphate which was reduced, absent or converted to a contraction, when compared with normal vessels. Vessels in which vasospasm was mild or absent relaxed as expected to these agents. The reduction in vessel diameter showed a highly significant correlation with the reduction in relaxation to bradykinin or adenosine-triphosphate. These results have demonstrated that impairment of endothelium-dependent vasorelaxation correlates with the existence of vasospasm. [Neurol Res 1996; 18: 553-558]     

Association between antidepressant side effects and functional impairment in patients with major depressive disorders

Patients with depression may not well be aware of antidepressant adverse events (AEs); however, no studies have assessed how these AEs affect their daily function. Therefore, to evaluate the relationship between the quality of AEs and functional impairment, we studied 482 outpatients with depressive disorders who were not receiving any antidepressant treatment prior to the baseline visit and started it thereafter in usual clinical settings. The Quick Inventory for Depressive Symptomatology Self-Report Japanese version and antidepressant AEs for subjective assessment (antiAS) were performed at baseline and 10 days after antidepressant initiation (i.e. second visit). Functional impairment was evaluated with the Sheehan Disability Scale (SDS) on the second visit. As a result, the SDS was positively associated with the number of AEs (β=0.089, p=0.022) in multiple linear regression analysis (adjusted R²=0.357, p<0.001). Subjects who experienced vertigo, nausea and insomnia had significantly more functional impairment than those who did not. Additionally, the number of severe AEs (β=0.151, p<0.001) was associated with a higher SDS score, and those AEs with a negative causal attribution to antidepressants in the antiAS significantly affected the SDS (β=0.105, p=0.008). AEs of antidepressants should be carefully monitored since they could negatively affect their daily function.     

Robert Liston (1794–1847): surgical anatomist and resurrectionist with an interest in hydrocephalus

Introduction

The Scottish surgeon Robert Liston was an accomplished anatomist of the nineteenth century. The study of anatomy during this day was often overshadowed by the so-called resurrectionists. Conclusions: The present historic paper reviews the life and contributions of Robert Liston and discusses his fascination with childhood hydrocephalus.     

Effects of Risperidone and Olanzapine Dose Reduction on Cognitive Function in Stable Patients With Schizophrenia: An Open-Label,Randomized, Controlled,Pilot Study

Impact of dose reduction of atypical antipsychotics on cognitive function has not been investigated in stable patients with schizophrenia. In this open-label, 28-week, randomized controlled trial, stable patients with schizophrenia treated with risperidone or olanzapine were randomly assigned to the reduction group (dose reduced by 50% in 4 weeks and then maintained) or maintenance group (dose kept constant). Assessments at baseline and week 28 included the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS), Positive and Negative Syndrome Scale (PANSS), and Drug-Induced Extrapyramidal Symptoms Scale (DIEPSS). Sixty-one patients were enrolled; 2 of 31 (6.5%) and 5 of 30 (16.7%) patients prematurely withdrew from the study in the reduction and maintenance groups, respectively. While no significant differences in change in the PANSS total score were observed between the 2 groups, the reduction group showed significantly greater improvements in the RBANS and DIEPSS total scores compared with the maintenance group (mean ± SD, +7.0±7.1 vs −0.1±8.0, P < .001; −0.9±1.7 vs +0.1±1.2, P = .010, respectively). This 6-month pilot study suggests that risperidone or olanzapine dose reduction of 50% can improve cognitive function for stable patients with schizophrenia. Due to the open-label design, small sample size, and short study duration, however, there is a need to confirm the finding through double-blind, larger scale trials with longer follow-up periods. Moreover, potential risks of relapse following antipsychotic dose reduction should be thoroughly investigated in longer term studies.Key words: antipsychotics, cognitive function, dose reduction, olanzapine, risperidone, schizophrenia     

Brain perfusion asymmetry in patients with oral somatic delusions

Oral cenesthopathy is a somatic delusion or hallucination involving the oral area and is categorized as a delusional disorder, somatic type. The pathophysiology of this intractable condition remains obscure. In this study, we clarified the pathophysiology of oral cenesthopathy by evaluating regional brain perfusion. We performed single photon emission computed tomography (SPECT) using ^99mTc-ethylcysteinate dimer in 16 subjects (cenesthopathy:control = 8:8). The SPECT images were visually assessed qualitatively, and quantitative analyses were also performed using a three-dimensional stereotactic region-of-interest template. The visual assessment revealed a right > left perfusion asymmetry in broad areas of the brain among the patients. The quantitative analysis confirmed that the regional cerebral blood flow values on the right side were significantly larger than those on the left side for most areas of the brain in the patients. A comparison of the R/(R + L) ratios in both groups confirmed the significant brain perfusion asymmetry between the two sides in the callosomarginal, precentral, and temporal regions in the patients. Qualitative evaluation of the SPECT images revealed right > left brain perfusion asymmetry in broad regions of the brain. Moreover, the quantitative analyses confirmed the perfusion asymmetry between the two sides in the frontal and temporal areas. Those may provide the key for elucidation of the pathophysiology of oral cenesthopathy.