Odontogenic myxoma: review of the literature and report of 30 cases from South Africa.

OBJECTIVE: The purpose of the study was to analyze the clinical and radiographic features of central odontogenic myxomas (OM) of the jaws diagnosed over 23 years in a black South African patient sample. STUDY DESIGN: Records of 30 cases of OMs with radiographs of diagnostic quality were retrieved from 52 cases of histopathologically verified OMs from the archives of the Oral Health Center at the University of Limpopo, South Africa. The age, sex, size, location, and radiographic features were compared with the literature. RESULTS: The study consisted of 21 females and 9 males. The correlation between age and size of the tumor was found to be statistically significant (P = .004). Septa were shown to be either reorientated cortical bone or sheets of dense fibrous connective tissue. Indistinct borders mimicked malignancy. The most common radiographic feature was the tennis-racket appearance. CONCLUSIONS: Variations in radiographic presentation make a radiological differential interpretation of OM challenging because the radiographic features overlap with those of other benign and malignant neoplasms.     

In humans the oxygen uptake slow component is reduced by prior exercise of high as well as low intensity

The aim of the study was to examine to what extent prior high- or low-intensity cycling, yielding the same amount of external work, influenced the oxygen uptake (V˙O₂) slow component of subsequent high-intensity cycling. The 12 subjects cycled in two protocols consisting of an initial 3 min period of unloaded cycling followed by two periods of constant-load exercise separated by 3 min of rest and 3 min of unloaded cycling. In protocol 1 both periods of exercise consisted of 6 min cycling at a work rate corresponding to 90% peak oxygen uptake (V˙O_2peak). Protocol 2 differed from protocol 1 in that the first period of exercise consisted of a mean of 12.1 (SD 0.8) min cycling at a work rate corresponding to 50% V˙O_2peak. The difference between the 3rd min V˙O₂ and the end V˙O₂ (ΔV˙O₂₍₆₋₃₎) was used as an index of the V˙O₂ slow component. Prior high-intensity exercise significantly reduced ΔV˙O₂₍₆₋₃₎. The ΔV˙O₂₍₆₋₃₎ was also reduced by prior low-intensity exercise despite an unchanged plasma lactate concentration at the start of the second period of exercise. The reduction was more pronounced after prior high- than after prior low-intensity exercise (59% and 28%, respectively). The results of this study show that prior exercise of high as well as low intensity reduces the V˙O₂ slow component and indicate that a metabolic acidosis is not a necessary condition to elicit a reduction in ΔV˙O₂₍₆₋₃₎. Accepted: 8 July 2000     

Neural Substrates of Psychotic Depression: Findings From the Global ECT-MRI Research Collaboration

Psychotic major depression (PMD) is hypothesized to be a distinct clinical entity from nonpsychotic major depression (NPMD). However, neurobiological evidence supporting this notion is scarce. The aim of this study is to identify gray matter volume (GMV) differences between PMD and NPMD and their longitudinal change following electroconvulsive therapy (ECT). Structural magnetic resonance imaging (MRI) data from 8 independent sites in the Global ECT-MRI Research Collaboration (GEMRIC) database (n = 108; 56 PMD and 52 NPMD; mean age 71.7 in PMD and 70.2 in NPMD) were analyzed. All participants underwent MRI before and after ECT. First, cross-sectional whole-brain voxel-wise GMV comparisons between PMD and NPMD were conducted at both time points. Second, in a flexible factorial model, a main effect of time and a group-by-time interaction were examined to identify longitudinal effects of ECT on GMV and longitudinal differential effects of ECT between PMD and NPMD, respectively. Compared with NPMD, PMD showed lower GMV in the prefrontal, temporal and parietal cortex before ECT; PMD showed lower GMV in the medial prefrontal cortex (MPFC) after ECT. Although there was a significant main effect of time on GMV in several brain regions in both PMD and NPMD, there was no significant group-by-time interaction. Lower GMV in the MPFC was consistently identified in PMD, suggesting this may be a trait-like neural substrate of PMD. Longitudinal effect of ECT on GMV may not explain superior ECT response in PMD, and further investigation is needed.     

The decrease in VO(2) slow component induced by prior exercise does not affect the time to exhaustion

In previous studies decreases in the VO(2) slow component were observed after prior heavy exercise. The observed effects after prior low-intensity exercise were rather controversial. The purpose of the present study was to more thoroughly examine the effects of prior low-intensity exercise on the VO(2) slow component. Furthermore, it has been suggested that the VO(2) slow component may be a determinant of exercise tolerance. Therefore we tested the hypothesis whether an attenuated VO(2) slow component induced by prior exercise could affect the time to exhaustion. Ten subjects performed four exercise protocols consisting of heavy cycling exercise (95 % VO(2)peak) until exhaustion. This constant-load exercise was performed without prior exercise (protocol NPE), or was preceded by 6 min heavy cycling exercise (protocol 6HPE), 12 min low-intensity cycling exercise (protocol 12LPE) or 6 min low-intensity cycling exercise (protocol 6LPE). The VO(2) slow component quantified as Delta VO(2 (end-2)) (669 +/- 90 ml x min (-1) in NPE) was significantly reduced after heavy as well as low-intensity exercise (respectively 47 %, 29 % and 17 % in 6HPE, 12LPE and 6LPE). This reduction lead to a significantly lower end VO(2) in 6HPE and 12LPE. The time to exhaustion (594 +/- 139 s in NPE), however, was unaffected by prior exercise rejecting our hypothesis that the attenuated VO(2) slow component could improve the capability to sustain exercise performance.     

Electroconvulsive therapy in Belgium: a questionnaire study on the practice of electroconvulsive therapy in Flanders and the Brussels Capital region

OBJECTIVES: We sought to review and describe the practice of electroconvulsive therapy (ECT) in Flanders and the Brussels Capital region, Belgium, in 2003. METHODS: A 30-item questionnaire was sent to all institutions that provided psychiatric care. Besides questions on training and general attitude toward ECT, most questions concerned technical aspects, quality, and organization of this treatment modality. RESULTS: All psychiatric departments offering ECT and 58% of the hospitals that do not conduct ECT replied to the questionnaire. Forty-three percent of the departments offering ECT indicated less than 10 treatment sessions per month. Forty-three percent of hospitals set a fixed number of treatments per course. Maintenance ECT and ECT on an outpatient basis were rather rare, except for a few departments. The major indication for ECT was depression (88%) rather than schizophrenia (8%), mania (3%), or other psychiatric disorders (1%). Propofol was the anesthetic most commonly used (74%). Seven departments (30%) used a sine wave device. Bilateral electrode placement was the preferred option in 91% of all departments and both fixed high dose and dose titration strategy were used equally (both 47.8%). CONCLUSION: The present findings demonstrate that the practice of ECT in Flanders and the Brussels Capital region in 2003 generally was not performed according to the available guidelines. ECT is underused in Flanders and the Brussels Capital region compared with other countries, although it is available in both specialized psychiatric facilities and in the psychiatric departments of general hospitals.     

Influence of DCA on pulmonary (.-)V(O2) kinetics during moderate-intensity cycle exercise

PURPOSE: To test the hypothesis that pharmacological activation of the pyruvate dehydrogenase enzyme complex (PDC) with dichloroacetate (DCA) would speed phase II pulmonary oxygen uptake ((.-)V(O2)) kinetics after the onset of subsequent moderate-intensity (40-45% ((.-)V(O2)) peak) cycle exercise. METHODS: Seven healthy males (mean +/- SD age 25 +/- 4 yr, body mass 75.3 +/- 9.4 kg) performed four "square-wave" transitions from unloaded cycling to a work rate requiring 90% of the predetermined gas exchange threshold either with or without prior infusion of DCA (50 mg x kg body mass in 50 mL saline). Pulmonary ((.-)V(O2)) was measured breath-by-breath in all tests and ((.-)V(O2)) kinetics were determined from the averaged individual response to each condition using nonlinear regression techniques. RESULTS: The blood [lactate] measured immediately before the onset of exercise was significantly reduced in the DCA condition (C: 1.1 +/- 0.3 vs DCA: 0.6 +/- 0.3 mM; P < 0.01) consistent with successful activation of the PDC. However, DCA had no discernible effect on the rate at which ((.-)V(O2)) increased toward the steady state after the onset of exercise as reflected in the phase II time constant (C: 28.5 +/- 11.8 vs DCA: 29.4 +/- 14.9 s). CONCLUSIONS: The results suggest that PDC activation does not represent a principal intramuscular limitation to ((.-)V(O2)) kinetics after the onset of moderate-intensity exercise.     

Propofol in the management of postictal delirium with clozapine-electroconvulsive therapy combination

Postictal delirium is an acute confusional state occurring during the immediate postictal phase in patients receiving electroconvulsive therapy that is characterized by motor agitation, disorientation, clouded consciousness, repetitive stereotyped movements, and poor response to commands. A schizophrenic patient with severe and recurrent postictal delirium is described. The possible role of the clozapine-electroconvulsive therapy combination in the occurrence of postictal delirium is discussed. Several management strategies were tried, with various degrees of success. Propofol proved to be effective in preventing agitation when used as induction agent or when administered at seizure end. However, propofol could not prevent a delirious state when only administered after the first signs of motor restlessness had emerged.