Treatment of intervention sites of malignant pleural mesothelioma with radiotherapy: a Dutch-Belgian survey.

A survey was performed on the radiotherapy practice of malignant pleural mesothelioma in The Netherlands and Belgium in 2002. Thirty-eight out of 47 centres (81%) responded. Prophylactic radiotherapy to intervention sites is given by 32/38 (84%) centres, with all centres offering palliative radiation. For both prophylactic and palliative indications, all centres use hypo-fractionated schedules. The present study shows that in the radiotherapy community in The Netherlands and in Belgium, a de facto consensus exists that both prophylactic and symptomatic radiotherapy to intervention sites of malignant pleural mesothelioma are effective and that hypo-fractionated schedules should be used.     

Improved Performance of Hip DXA Using a Novel Region of Interest in the Upper Part of the Femoral Neck: In Vitro Study Using Bone Strength as a Standard of Reference

We tested the hypothesis that bone mineral density (BMD) and bone mineral content (BMC) in proximal human femur specimens in the upper neck region of interest (ROI) and femoral neck axis length (FNAL) provide a significantly better prediction of femoral bone strength than standard ROIs in vitro. BMD and BMC were measured in 110 proximal femur specimens using a standard dual-energy X-ray absorptiometry (DXA) scanner. The analysis included a new ROI in the upper neck as well as the standard ROIs. FNAL was obtained from the scan images. The specimens' failure-load was measured in a mechanical loading device, simulating a fall on the greater trochanter. For the standard ROIs, correlations between failure-load and BMD ranged from R2 = 0.64 (shaft ROI) to R2 = 0.70, p < 0.001 (femoral neck). Prediction of strength by BMD did not significantly differ from those of BMC (R2 ranging from 0.65 to 0.75, p < 0.001). In the upper neck ROI, for both BMD and BMC correlations with failure-load were higher (R2 = 0.76 and 0.81, respectively; p < 0.001). A lower, yet still significant, correlation was found between FNAL and bone strength (R2 = 0.23, p < 0.001). Normalization of failure-load with respect to FNAL did not significantly increase the correlations with densitometric measures. This study provides in vitro evidence indicating that among the ROIs of the proximal femur the newly defined upper neck ROI provides the best prediction of bone strength. Only a weak association was observed between failure load and FNAL.     

Classic Benzodiazepines Modulate the Open-Close Equilibrium in α1β2γ2L γ-Aminobutyric Acid Type A Receptors

Background: Classic benzodiazepine agonists induce their clinical effects by binding to a site on [gamma]-aminobutyric acid type A (GABAA) receptors and enhancing receptor activity. There are conflicting data regarding whether the benzodiazepine site is allosterically coupled to [gamma]-aminobutyric acid binding versus the channel open-close (gating) equilibrium. The authors tested the hypothesis that benzodiazepine site ligands modulate [alpha]1[beta]2[gamma]2L GABAA receptor gating both in the absence of orthosteric agonists and when the orthosteric sites are occupied.

Methods: GABAA receptors were recombinantly expressed in Xenopus oocytes and studied using two-microelectrode voltage clamp electrophysiology. To test gating effects in the absence of orthosteric agonist, the authors used spontaneously active GABAA receptors containing a leucine-to-threonine mutation at residue 264 on the [alpha]1 subunit. To examine effects on gating when orthosteric sites were fully occupied, they activated wild-type receptors with high concentrations of a partial agonist, piperidine-4-sulfonic acid.

Results: In the absence of orthosteric agonists, the channel activity of [alpha]1L264T[beta]2[gamma]2L receptors was increased by diazepam and midazolam and reduced by the inverse benzodiazepine agonist FG7142. Flumazenil displayed very weak agonism and blocked midazolam from further activating mutant channels. In wild-type receptors activated with saturating concentrations of piperidine-4-sulfonic acid, midazolam increased maximal efficacy.     

Highly resolved in vivo 1H NMR spectroscopy of the mouse brain at 9.4 T.

An efficient shim system and an optimized localization sequence were used to measure in vivo 1H NMR spectra from cerebral cortex, hippocampus, striatum, and cerebellum of C57BL/6 mice at 9.4 T. The combination of automatic first- and second-order shimming (FASTMAP) with strong custom-designed second-order shim coils (shim strength up to 0.04 mT/cm2) was crucial to achieve high spectral resolution (water line width of 11-14 Hz). Requirements for second-order shim strengths to compensate field inhomogeneities in the mouse brain at 9.4 T were assessed. The achieved spectral quality (resolution, S/N, water suppression, localization performance) allowed reliable quantification of 16 brain metabolites (LCModel analysis) from 5-10-microL brain volumes. Significant regional differences (up to 2-fold, P < 0.05) were found for all quantified metabolites but Asp, Glc, and Gln. In contrast, 1H NMR spectra measured from the striatum of C57BL/6, CBA, and CBA/BL6 mice revealed only small (<13%, P < 0.05) interstrain differences in Gln, Glu, Ins, Lac, NAAG, and PE. It is concluded that 1H NMR spectroscopy at 9.4 T can provide precise biochemical information from distinct regions of the mouse brain noninvasively that can be used for monitoring of disease progression and treatment as well as phenotyping in transgenic mice models.     

Detection of microemboli in the subclavian vein of patients undergoing haemodialysis and haemodiafiltration using pulsed Doppler ultrasound.

BACKGROUND: The pathophysiology leading to pulmonary side effects during haemodialysis and haemodiafiltration is not yet fully understood. Chronic microembolization, which can be demonstrated by pulsed Doppler ultrasound, may be one cause. METHODS: The study cohort consisted of 24 long-term dialysis patients undergoing haemodialysis (n=21) and online-haemodiafiltration (n=3), respectively. The subclavian vein downstream to the venous access was investigated during different phases of the procedure using a 2-MHz pulsed ultrasound device. RESULTS: In all periods investigated (connection, dialysis, disconnection), numerous microembolic signals (MES) were found in the subclavian vein. The numbers of MES detected during haemodiafiltration (314-709 MES per 10 min) were higher than during haemodialysis (0-81 MES per 10 min). CONCLUSIONS: The composition (gaseous or solid) and origin (pump, tubing system or shunt) of the microemboli detected remains unclear. Chronic microembolization may be one cause of pulmonary complications of haemodialysis and haemodiafiltration. The detection method described in this article will help us to better understand this process and to determine what role microemboli might play in pulmonary and central nervous system disorders. It may also help to optimize the devices and techniques used.     

Remote-controlled catheter ablation of accessory pathways: results from the magnetic laboratory.

AIMS: This study evaluates feasibility, safety, and efficacy of magnetic remote-controlled accessory pathway (AP) ablation. METHODS AND RESULTS: The novel magnetic navigation system (MNS) (Niobe, Stereotaxis) creates a steerable magnetic field (0.08 T) controlling the distal magnetic tip of an ablation catheter. In conjunction with a catheter advancer system (Cardiodrive, Stereotaxis) remote catheter ablation is enabled. Conventional electrophysiology study identified AP conduction in 59 patients (37 males, 36+/-14 years, 60 APs). First generation 1-magnet tip (1-M) (group I, n=18), second generation bipolar 3-magnet tip (3-M) (group II, n=27), and third generation quadripolar 3-magnet tip catheters (3-M quad.) (group III, n=14) were used for magnetic remote-controlled ablation. Successful AP ablation was achieved in 67% (group I), 85% (group II), and 92% (group III). A significant decrease of median [IQR: Q1-Q3] fluoroscopy time and dosage was observed: 21.2 [12.1-33.8] min, 1110 [395-3234] microGym2 (group I); 6.5 [4.4-15.4] min, 290 [129-489] microGym2 (group II), and 4.9 [3.4-8.0] min, 129 [74-270] microGym2 (group III). Mean procedure time (217+/-67 min; 182+/-68 min, and 172+/-90 min) significantly decreased in group III. Median number [Q1-Q3] of radiofrequency current applications in groups I, II, and III was 4 [2-9], 4 [2-6], and 2 [2-4], respectively. No complications occurred. CONCLUSION: Remote AP ablation is safe and feasible using the novel MNS. Introduction of the 3-magnet quadripolar ablation catheter significantly improved the efficacy of the procedure.     

Meta-analysis of randomized controlled comparisons of psychopharmacological and psychological treatments for anxiety disorders.

BACKGROUND: A number of meta-analyses have led to contradictory results regarding the efficacy of the psychological and pharmacological treatment of anxiety disorders. The main reasons for these inconsistent results seem to be the inclusion of heterogeneous studies and influences of selection biases. We performed a meta-analysis, which only included studies using a direct comparison of pharmacological, psychological, or combined treatments. METHOD: Sixteen studies on panic disorder, six studies on social anxiety disorder, and two studies on generalized anxiety disorder have been analyzed. Effect sizes for differences between the different treatment modalities were calculated. Also, the effect sizes of the pre-post differences were calculated. RESULTS: Pharmacological treatment, cognitive-behavioural treatment, and the combination of both treatment modalities all led to substantial improvement between pre- and post-treatment. Combined pharmacological and psychological treatment was superior to the monotherapies for panic disorder. For social anxiety disorder, there is only preliminary support for combined treatment. Due to lack of sufficient data, no final conclusions can be drawn for generalized anxiety disorder. CONCLUSIONS: While drug treatment and CBT showed equal efficacy, only in panic disorder the combination of pharmacological and psychological treatment was superior to either treatment alone. For the other anxiety disorders, the evidence for greater efficacy of combination treatment is still not sufficient due to lack of studies.