PROTON MAGNETIC RESONANCE SPECTROSCOPY IN DEMENTIA OF ALZHEIMER TYPE

Reduced N-acetyl aspartate (NAA) and increased myo-inositol (MI) levels have been reported in patients with dementia of Alzheimer type (DAT) in comparison with controls. We wished to assess the validity of these findings and to evaluate possible correlations of metabolite proportions with cognitive dysfunction in DAT. Twelve patients with DAT and 10 healthy age-matched controls were included. The severity of dementia was assessed using different scales including the Mini-Mental State Examination. MRS was performed with a conventional 1.5 Tesla scanner in a single voxel in the centrum semi-ovale (TE=30 ms or TE=136 ms TR=1500 ms). The evaluation of MRS results was limited by low interrater, intermeasurement (different echo times) and test–retest reliabilities, by a high interindividual variance and by the failure to measure absolute metabolite concentrations. These problems in mind, it was remarkable that previously reported reductions of NAA levels in patients with DAT could be reproduced in the present sample. The proportion of NAA was diminished in demented subjects in comparison with controls (37% vs 44.90%; short TE). A non-significant trend towards minor reductions of creatine, choline and MI proportions in these subjects might indicate that proportions of other metabolites necessarily increase when NAA is reduced. Cognitive dysfunction of demented subjects was significantly correlated with reductions of NAA, but not with increases of MI. Due to the present technical and methodological problems and to the non-specificity of findings, proton MRS cannot be applied to support the diagnosis of DAT in a clinical setting. © 1997 by John Wiley & Sons, Ltd.     

NUCLEAR p53 OVEREXPRESSION IS AN INDEPENDENT PROGNOSTIC PARAMETER IN NODE-NEGATIVE NON-SMALL CELL LUNG CARCINOMA

The prognosis of operated patients with non-small cell lung cancer (NSCLC) is poor despite thorough pre-operative staging. An improved preselection is needed of patients likely to profit from surgery. This study was undertaken to evaluate the prognostic significance of nuclear p53 overexpression in a cohort of 247 surgically treated patients with NSCLC. It showed that the prevalence of immunohistochemically detectable p53 overexpression varied between different tumour types. p53 overexpression was equally frequent in large cell carcinoma (53 per cent) and in squamous cell carcinoma (54 per cent), but significantly less frequent in adenocarcinoma (34 per cent; P =0·009). p53 overexpression was particularly rare in bronchioloalveolar carcinoma (positivity in 1 of 17 cases). These variations may reflect aetiological differences between the histological subtypes. p53 overexpression was also associated with high tumour grade ( P =0·0157) and the presence of lymph node metastasis ( P =0·0259), but not with advanced tumour stage. Survival analysis showed no difference in clinical outcome between p53-positive and p53-negative tumours within 101 node-positive tumours. In contrast, survival time was significantly better in p53-negative tumours than in p53-positive tumours within the group of 113 node-negative tumours ( P =0·032). Stepwise regression analysis showed that p53 overexpression is an independent prognostic factor in node-negative NSCLC.     

Neonatal rat cartilage has the capacity for tissue regeneration

One of the most relevant issues in future medicine is tissue regeneration. Transplantation medicine alone cannot solve the problem of incurable conditions of vital organs. One approach to this might be the replication of the spontaneous regeneration that is found in embryonic/neonatal tissue. In this study, a tissue model for basic investigation of regeneration mechanisms in vivo was established. We demonstrated by histology and immunohistochemical staining for types I and II collagen that neonatal rat cartilage unlike adult cartilage has the capacity for rapid scarfree regeneration after full-thickness incision. The underlying mechanism was identified in the preserved proliferative capacity of neonatal chondrocytes. This in vivo model should prove useful in further studies of the role of cellular (e.g., GA cell cycle regulators) and extracellular (e.g., cytokines) factors in tissue regeneration and wound healing.     

'Healthy Living is Fun' A creative way of health education

‘Healthy living is fun’ is a health education programmefor pupils aged 8–10 years. It consists of a curriculumcovering seven health topics, and was developed by a team ofa physician and teachers. The programme follows an integrated,cognitive concept of health education. By a creative approachthe pupils learn to appreciate their body and, consequently,to avoid risk factors. A prospective evaluation study is beingcarried out in cooperation with the German Institute for HighBlood Pressure Research, Heidelberg, Federal Republic of Germany.     

Polyurethane Leads: Facts and Controversy

Une comparaison des électrodes de stimulation en polyuréthane et en silicone est présentée. Lorsue ľon compare tes qualités mécaniques et électriques, les qualités de friction et la stabilité hydrolytique, les deux matériaux paraissent capables ďêtre utilisés comme game des sondes ďélectrode. Néanmoins, en raison des craquelures de surface observé'es avecle polyuréthane il est nécessaire ďobtenir des surfaces aussi précises et parfaites que possible. De plus, les manoeuvres de torsion et de courbure doivent être évitées lors de ľimplantation. Enfin, la surveillance à long terme doit être assurée ďune façon routiniere.
A comparison of polyurethane and silicone cardiac pacing leads is presented. In comparing mechanical and electrical properties, friction coefficient and hydrolytic stability, both are highly qualified for use as electrode sheaths. The occurrence of surface cracking of polyurethane leads is examined. Several suggestions are proposed for dealing with the manufacture of new leads, the technique of implantation, and the follow-up required for successful surveillance.     

Risk Assessment for Coronary Interventions

Risk factors associated with a poor acute outcome of coronary interventions changed significantly as a result of the development of interventional techniques and adjunct pharmacological therapies. In the 1980s morphological parameters as classified by the modified AHA/ACC score were predictive of MACE. With advanced experience and technological improvements in the early 1990s only some lesion parameters retained their predictive power for balloon angioplasty. In the era of new devices some of the lesion parameters (bifurcational lesions, calcification) remained associated with a worse acute outcome, but procedure-related parameters (e.g., length of stented segment, remaining dissection) had more impact on the outcome. Some clinical parameters like age, presence of an acute coronary syndrome, and impaired left ventricular function are still predictive of a worse outcome. The impact of thrombocyte activation, which is an essential feature of the acute coronary syndrome, may be modified by application of GP IIb/IIIa inhibitors. Because of the different study designs, reported MACE rates among recently published studies differ significantly. A generalizable scoring system for risk assessment, which takes into account the different and conflicting study results, does not appear to be imminent.     

Clinical Impact of an Open‐Irrigated Radiofrequency Catheter with Direct Force Measurement on Atrial Fibrillation Ablation

Background: Electrode‐tissue contact is crucial for adequate lesion formation in radiofrequency catheter ablation (RFCA). Objective: We assessed the impact of direct catheter force measurement on acute procedural parameters during RFCA of atrial fibrillation (AF). Methods: Fifty consecutive patients (28 male) with paroxysmal AF who underwent their first procedure of circumferential pulmonary vein (PV) isolation (PVI) were assigned to either RFCA using (1) a standard 3.5‐mm open‐irrigated‐tip catheter or (2) a catheter with contact force measurement capabilities. Using the endpoint of PVI with entry and exit block, acute procedural parameters were assessed. Results: Procedural data showed a remarkable decline in ablation time (radiofrequency time needed for PVI) from 50.5 ± 15.9 to 39.0 ± 11.0 minutes (P = 0.007) with a reduction in overall procedure duration from 185 ± 46 to 154 ± 39 minutes (P = 0.022). In parallel, the total energy delivered could be significantly reduced from 70,926 ± 19,470 to 58,511 ± 14,655 Ws (P = 0.019). The number of acute PV reconnections declined from 36% to 12% (P = 0.095). Conclusions: The use of contact force sensing technology is able to significantly reduce ablation and procedure times in PVI. In addition, energy delivery is substantially reduced by avoiding radiofrequency ablation in positions with insufficient surface contact. Procedural efficacy and safety of this new feature have to be evaluated in larger cohorts. (PACE 2012; 35:1312–1318)     

ICD Therapy in Children and Young Adults: Low Incidence of Inappropriate Shock Delivery

Introduction: Implantable cardioverter defibrillator (ICD) therapy of life‐threatening arrhythmias in pediatric patients is feasible; however, recent studies report a high incidence of inappropriate shock deliveries. Methods: The data of all recipients of an ICD at the Charité, Department of Pediatric Cardiology, between January 2001 and November 2007 were retrospectively analyzed regarding underlying cardiac disorders, arrhythmias, medication, ablation procedures, leads and devices, programming, and ICD therapies. Results: A total of 33 patients underwent ICD implantation, with a median age of 16.5 years (range 8–36 years) and a mean weight of 61 ± 20.9 kg. Underlying cardiac disorders were electrical heart disease (27%), cardiomyopathy (30%), congenital heart disease (33%), and others (9%). Eighty‐five percent received antiarrhythmic drugs, and 12 ablation procedures were performed in nine patients (27%). The devices were programmed individually according to the underlying diseases and arrhythmias. During follow‐up, a total of 63 shock therapies were delivered in 11 patients, while a majority of 34 shocks occurred in one patient (no therapies in 22 of 33 patients). Only two such therapies were inappropriate, both delivered for atrial flutter. Conclusions: In children and young adults receiving ICD therapy, the combination of strategies to prevent ventricular arrhythmias using specific drug therapy, ablation procedures, and individual programming with improved devices and leads causes a low incidence of inappropriate shock delivery. (PACE 2010; 33:734–741)