Diagnostic Value of Synchronized Transesophageal Atrial Pacing

Synchronized transesophageal atrial pacing (single and double extrastimuli) was used in 137 patients with various tachycardias inducible by atrial pacing during transesophageal electrophysiological study (EPS). This pacing mode in five patients initiated atrioventricular tachycardias with ipsilateral bundle branch block not seen when using other pacing modes. During the tachycardia, single or double extrastimuli caused ipsilateral bundle branch block disappearance in two patients with atrioventricular tachycardia, and changed AV activation ratio in one patient with atrioventricular junctional reentrant tachycardia. This pacing mode causes very little discomfort, what is important in children, and enhances diagnostic abilities of transesophageal EPS. So, this pacing mode should be used routinely as one of the steps of transesophageal EPS.     

Electrical Termination of Tachyarrhythmias by Discrete Pulses

Reentrant tachycardias can often be terminated by discrete pacing stimuli that penetrate the reentrant circuit. The ability of discrete stimuli to terminate an arrhythmia depends on the timing of the stimulus, the distance from the site of reentry where the stimulus is applied, the electrophysiologic properties of the myocardium between the site of stimulation and the site of reentry, and the size of the reentrant circuit.
Modes of pacing used to terminate tachycardia have included single or multiple timed extrastimuli, overdrive pacing, burst pacing and competitive asynchronous (underdrive) pacing. Patient-triggered devices that deliver asynchronous pacing stimuli are routinely available. Newer devices have been developed that automatically sense the onset of tachycardia and respond with pacing stimuli. These devices have been highly effective in selected patients with supraventricular tachycardia. The seriousness of occasional pacing-induced acceleration of ventricular tachycardia or conversion to ventricular fibrillation has limited the application of these devices in patients with ventricular arrhythmias. Pre-implantations electrophysiologic studies are necessary to document arrhythmia mechanisms and to determine the feasibility of various pacing modalities in treating the tachycardia. The potential for complicating arrhythmias (atrial fibrillation/flutter or ventricular fibrillation) must also be tested.
Future devices designed for terminating tachycardias with discrete pulses should be capable of being programmed to respond with one or more of the various modalities available. These devices should automatically and reliably sense both tachycardia onset and termination, and should adjust their responses appropriately if initial stimulation sequences fail to terminate the arrhythmia.     

A Marrow Chromosomal Abnormality Preceding Clinical Leukemia in Down's Syndrome

During a routine diagnostic cytogenetic study of the marrow of a child withDown’s syndrome, a minor line of cells with a complement of 50 chromosomeswas discovered. The predominant cell in marrow and blood had 47 chromosomes with the standard trisomy in Group 21-22. Although anemia and thrombocytopenia were present, other diagnostic criteria of leukemia did not appearuntil several weeks later. It is proposed that careful cytogenetic studies combined with serial clinical evaluation may disclose important relationships between chromosomal mutation, aneuploid stemlines, and the production andevolution of neoplasms.

Submitted on December 29, 1965 Accepted on September 14, 1966     

Treatment of psoriasis with fumaric acid esters: results of a prospective multicentre study

Systemic treatment of psoriasis with fumaric acid esters (FAE) has been found effective by empirical means. In recent years clinical studies have confirmed the antipsoriatic activity of a defined mixture of different FAE. The aim of the present prospective multicentre study was to investigate further the efficacy and safety of FAE therapy in a large number of patients with severe psoriasis vulgaris. From 101 patients included in the study 70 completed the treatment period of 4 months. Discontinuation was due to adverse events in seven, lack of efficacy in two, and other reasons, such as non-attendance for scheduled visits, in 22 patients. Evaluation of overall efficacy showed a decrease in psoriasis area and severity index of 80% after 4 months of FAE therapy. Laboratory investigations revealed a slight overall decrease of lymphocytes during the treatment period which was more than 50% below baseline in 10 patients. During weeks 4 and 8 mean eosinophil counts were above the normal range. At the end of FAE therapy elevated eosinophil counts had returned to normal values. None of the patients showed changes in renal function parameters throughout the study. Adverse events were reported in 69% of the patients mainly consisting of gastrointestinal complaints (56%) and flushing (31%). In five patients gastrointestinal complaints and in two patients flushing led to withdrawal from the study. Taken together the results of this multicentre study showed in a large number of patients that systemic FAE treatment is effective in severe psoriasis vulgaris. Transient eosinophilia seems to be a characteristic feature of FAE therapy, while lymphocytopenia is usually mild. Adverse effects are dose-related and consist mainly of gastrointestinal complaints and flushing.     

bcl-1 REARRANGEMENT AND CYCLIN D1 PROTEIN EXPRESSION IN MANTLE CELL LYMPHOMA

Centrocytic lymphoma, or mantle cell lymphoma (MCL), is characterized by a chromosomal translocation t(11;14) (q13;q32) involving the bcl-1 locus on chromosome 11. Cyclin D1 is a cell-cycle regulatory protein essential for G1–S transition and has been identified as a potential transforming gene affected by the translocation. In this study, 32 cases of MCL were analysed for the bcl-1 rearrangement and cyclin D1 protein expression. In 17 cases, a rearrangement at the major translocation cluster of bcl-1 could be detected. Twenty-four cases exhibited nuclear cyclin D1 expression that was not detectable in other B-cell lymphomas ( n =40) or in normal B-cells. In nine MCL samples, cyclin D1 was expressed without a detectable bcl-1 rearrangement. The detection of a t(11;14) by means of classical cytogenetics in one of these cases, however, may suggest that this discrepancy could be due to chromosomal breakages outside the typical translocation cluster region. In two cases, a bcl-1 rearrangement was not accompanied by cyclin D1 expression. This study provides further evidence that cyclin D1 is involved in the pathogenesis of MCL and can be exploited as a diagnostic marker in the differential diagnosis of B-cell lymphomas and in the identification of MCL.