Asthma und asthmatypische Beschwerden bei Schulkindern: Vergleich von Gebieten in Deutschland und Osterreich

Conclusion

Geographical differences in morbidity of asthma and asthmalike complaints were ascertained and remained stable after adjustment for potential confounders. However, the choice of the way of presentation (relative risk versus deviation from the weighted mean of the prevalences) can provoke different suggestive effects.     

Intrathecal midazolam reduces isoflurane MAC and increases the apnoeic threshold in rats

Canadian Journal of Anesthesia/Journal canadien d'anesthésie - The purpose of this study was to examine the anaesthetic requirement of intrathecal midazolam in a dose-response fashion in...     

Alternatives to Autogenous Bone Graft: Efficacy and Indications

Bone grafting is frequently used to augment bone healing with the numerous approaches to reconstructing or replacing skeletal defects. Autologous cancellous bone graft remains the most effective grafting material because it provides the three elements required for bone regeneration: osteoconduction, osteoinduction, and osteogenic cells. Autologous cortical bone graft provides these three components to a limited extent as well and also provides the structural integrity important in reconstruction of larger defects. However, because autogenous grafting is associated with several shortcomings and complications, including limited quantities of bone for harvest and donor-site morbidity, alternatives have been used in a wide range of orthopaedic pathologic conditions. Grafting substitutes currently available include cancellous and cortical allograft bone, ceramics, demineralized bone matrix, bone marrow, and composite grafts. No single alternative graft material provides all three components for bone regeneration. The clinical applications for each type of material are dictated by its particular structural and biochemical properties. Composite grafts consisting of several materials are often used to maximize bone healing, especially where the grafting site is compromised.     

Dosimetric verification of a commercial inverse treatment planning system

A commercial three-dimensional (3D) inverse treatment planning system, Corvus (Nomos Corporation, Sewickley, PA), was recently made available. This paper reports our preliminary results and experience with commissioning this system for clinical implementation. This system uses a simulated annealing inverse planning algorithm to calculate intensity-modulated fields. The intensity-modulated fields are divided into beam profiles that can be delivered by means of a sequence of leaf settings by a multileaf collimator (MLC). The treatments are delivered using a computer-controlled MLC. To test the dose calculation algorithm used by the Corvus software, the dose distributions for single rectangularly shaped fields were compared with water phantom scan data. The dose distributions predicted to be delivered by multiple fields were measured using an ion chamber that could be positioned in a rotatable cylindrical water phantom. Integrated charge collected by the ion chamber was used to check the absolute dose of single- and multifield intensity modulated treatments at various spatial points. The measured and predicted doses were found to agree to within 4% at all measurement points. Another set of measurements used a cubic polystyrene phantom with radiographic film to record the radiation dose distribution. The films were calibrated and scanned to yield two-dimensional isodose distributions. Finally, a beam imaging system (BIS) was used to measure the intensity-modulated x-ray beam patterns in the beam's-eye view. The BIS-measured images were then compared with a theoretical calculation based on the MLC leaf sequence files to verify that the treatment would be executed accurately and without machine faults. Excellent correlation (correlation coefficients > or = 0.96) was found for all cases. Treatment plans generated using intensity-modulated beams appear to be suitable for treatment of irregularly shaped tumours adjacent to critical structures. The results indicated that the system has potential for clinical radiation treatment planning and delivery and may in the future reduce treatment complexity.     

Gamma Knife Radiosurgery of the Glomus Jugulare Tumour – Early Multicentre Experience

Leksell Gamma Knife was used to treat 66 patients with glomus jugulare tumour at 6 European sites between 1992-1998. The age of the patients ranged between 18-80 years (median 54 years). Gamma Knife radiosurgery was a primary treatment in 30 patients (45. 5%). Open surgery preceded radiosurgery in 24 patients (36.4%), embolisation in 14 patients (21.2%) and fractionated radiotherapy in 5 patients (7.6%). The volume of the tumour ranged 0.5-27 cm(3) (median 5,7 cm(3)). The minimal dose to the tumour margin ranged between 10-30 Gy (median 16.5 Gy). After radiosurgery 52 patients were followed, the follow up period was 3-70 months (median 24 months). Neurological deficit improved in 15 patients (29%) and deteriorated in 3 patients (5,8%), one transient and two persistant. Neuroradiological follow up using MRI or CT was performed in 47 patients 4-70 months (median 24 months) after radiosurgery. Tumour size decreased in 19 patients (40%) while in the remaining 28 patients (60%) no change in the tumour volume was observed. None of the tumours increased in volume during the observation period. Control angiography was performed in 6 patients. Pathological vascularisation completely disappeared in one patient, reduced in two and there was no change in the remaining three. Radiosurgery proves to be a safe treatment for glomus jugulare tumour with no mortality and no acute morbidity. Because of its naturally slow growth rate, up to 10 years of follow up will be necessary to establish a cure rate after radiosurgery for these lesions.     

Rape attitudes amongst British medical students

OBJECTIVES: To examine the rape attitudes of a sample of 252 British medical students. DESIGN: A 20-item questionnaire was used. SETTING: A London medical school. SUBJECTS: Fourth-year medical students. RESULTS: In general, students were well informed on legal and factual issues regarding rape and sexual assault. However, significant differences were found in the attitudes to rape between males and females. Female students were significantly more positive in their responses to victims. CONCLUSIONS: These results support findings from previous studies of rape attitudes in other professional groups. Better knowledge and enlightened attitudes amongst health care staff can have a significant impact on the management of sexual assault and influence the likelihood of victims presenting for treatment. In conclusion, this study emphasizes the importance of teaching about sexual violence in British medical schools.     

Learning and memory-enhancing effects of Ro 15-4513: a comparison with flumazenil.

Synthetic benzodiazepines produce an anterograde amnesia, which can be reversed by selective benzodiazepine antagonists or inverse agonists. It has therefore been suggested that the memory-enhancing effects of the antagonists are due to antagonism of an endogenous "benzodiazepine-like" endocoid. If the memory-enhancing effects of the benzodiazepine antagonists are determined predominantly by the antagonism of such endogenous benzodiazepine-ligands, then it could be hypothesized that administration of an inverse agonist, which produces effects functionally opposite to those of benzodiazepine agonists, may also mimic the effects of benzodiazepine antagonists but not produce effects greater than those of the pure antagonists. The purpose of the present study was therefore to investigate the memory-enhancing effects of the benzodiazepine inverse agonist, ethyl-8-amido-5,6-dihydro-5-methyl-6-oxo-4H-imidazo [1,5a] [1,4] benzodiazepine-3-carboxylate (Ro 15-4513) in young HSD:(ICR)BR mice and to compare these effects with those of the benzodiazepine antagonist, flumazenil. Pretraining injections of flumazenil and Ro 15-4513 (2.5 and 10.0 mg/kg) enhanced equally, both the acquisition and the retention of a task for 1 week requiring mice to discriminate the correct arm of a T-maze, to avoid a mild electric shock. Pretreatment with Ro 15-4513 also dose-dependently protected the animals from experimental amnesia, induced by the cholinergic receptor antagonist, scopolamine in a second model of memory, in which mice were required to passively avoid a dark chamber after shock. In contrast, Ro 15-4513, injected prior to daily active avoidance sessions, failed to significantly improve either the acquisition or retention performance.(ABSTRACT TRUNCATED AT 250 WORDS)     

Within-subject behavioral analysis of recent memory in aging mice

Two experiments addressed the utility of a T-maze, delayed reversal paradigm for assessment of recent memory impairment in aging C57BL/6NNia mice. This paradigm involved acquisition of a learning set for identification of the correct arm choice in a daily multiple-trial discriminated avoidance session. During each session, the correct arm was always opposite that entered on an initial "information trial" and maximal performance thus required a reversal (or "lose-shift") strategy. Once the learning set had been acquired, retention performance was examined following delays of varying length which were introduced following the information trial during each session. In the first experiment, acquisition and retention components of delayed reversal were considered in a cross-sectional study involving separate groups of mice aged 7, 10, 15, or 27 months. Analysis of acquisition components suggested that relative to young mice, the old mice were slower to acquire both the first reversal and the learning set. Analysis of the retention phase suggested that memory decay gradients for goal arm discrimination became more pronounced with increasing age, whereas decay gradients for the avoidance response were similar among the age groups. Correlational analysis of data for the old mice suggested independence of age-related deficits in the acquisition and recent memory components of the delayed reversal paradigm. In the second experiment, survivors from the previous 7- and 10-month-old groups were retested when 27 months of age. The cross-sectional and longitudinal data led to the same conclusions with regard to the effect of age on recent memory function. Overall, these results suggest that the delayed reversal paradigm will be a valuable tool in the analysis and evaluation of interventions potentially affecting age-related cognitive impairment.     

Neurobehavioral biomarkers of aging: influence of genotype and dietary restriction

Because of the importance of central nervous system (CNS) functions to productive capacity and quality of life, biomarkers of these functions will play a key role in evaluating the success of interventions targeting aging processes. The CNS biomarkers may also be useful for predicting aging in other systems and in the organism as a whole. Age-related behavioral changes, the products of CNS aging, have content and predictive validity with respect to human functional capacities and may, therefore, represent important "neurobehavioral" markers of functional aging. This article presents a discussion of some behavioral paradigms which are currently being considered as neurobehavioral biomarkers of aging in mice and the experimental approaches being employed in the assessment of their validity. Studies conducted in the authors' laboratory using dietary restriction and genetic comparisons to evaluate the validity of neurobehavioral biomarkers have revealed several methodological concerns, and hypothetical and empirical examples of these pitfalls are described and discussed. In spite of those concerns, it is concluded that approaches to validity using genetic comparisons and dietary restriction can be successfully implemented and should ultimately lead to identification of valid and useful neurobehavioral biomarkers of aging.