THE PROTEOGLYCAN DSD-1-PG OCCURS IN PERINEURONAL NETS AROUND PARVALBUMIN-IMMUNOREACTIVE INTERNEURONS OF THE RAT CEREBRAL CORTEX

Proteoglycans involved in the shaping of the developing brain are often preserved in the adult brain in more restricted locations. We have studied the fate of DSD-1-PG, a chondroitin sulfate proteoglycan containing the hybrid epitope DSD-1. DSD-1-PG exerts neurite outgrowth promoting activity and has been shown to occur in the developing brain during late brain development and into adulthood. In the adult rat brain, monoclonal and polyclonal antibodies against DSD-1-PG labelled only the circumference of a selected subpopulation of neurons. These nerve cells invariably expressed the calcium-binding protein parvalbumin. The label occupied the extracellular space in close vicinity to the cell body, surrounding axon terminals and glial end feet, but was absent from synaptic clefts. DSD-1-PG is thus shown to be an additional representative of the growing list of substances found in perineuronal locations in the adult mammalian brain. Copyright © 1996 ISDN. Published by Elsevier Science Ltd.     

Patient Acceptance of the Implantable Cardioverter Defibrillator in Ventricular Tachyarrhythmias

Besides surgical problems, recipierifs of implantable cardioverter defibrillators (ICDs) are faced with psychological and social adjustments. Successful ICD therapy is influenced by the patients' perceived concerns regarding device, discharge, changes in life style, and complications. In order to assess patients' acceptance of the ICD, the psychological profile of 57 consecutive patients was evaluated using a specifically designed questionnaire and the State Trait Anxiety Inventory (STAI). The results showed that 20 patients staled fear of ICD discharge, 12 patients revealed physical discomfort due to the device, and limited quality-of-life occurred in 8 patients. Fifty-five of 57 patients answered that it was worth having an ICD device implanted, 30 (53%) patients returned to active life, and 56 (98%) would advise another patient to undergo implantation if necessary. Overall, there was only a slight, but insignificant, decrease in the level of anxiety within the total patient population after ICD implantation. However, a comparison of two subgroups indicated that the state of anxiety was significantly higher in patients < 50 years of age as well as in patients having received > 5 shocks versus those > 50 years of age and having experienced < 5 shocks. In general, the acceptance of the ICD as a tool in managing life-threatening ventricular tachyarrhythmias is high. Besides the increased survival rate, quality-of-life and patient acceptance are important criteria for successful ICD therapy.     

Congenital Myocardial Sympathetic Dysinnervation (CMSD)—A Structural Defect of Idiopathic Long QT Syndrome

Concerning the pathogenetic mechanism of idiopathic long QT syndrome (LQTS), the hypothesis of a specific sympathetic imbalance has gained general acceptance, but its validity has never been proven. To test this hypothesis I-123-MIBG, an analogue of norepinephrine and guanethidine, was used to provide scintigraphic display of the efferent cardiac sympathetic innervation. Twelve members of four LQTS families (mean age 38.2 +/- 17.2 years, eight males) and eight healthy volunteers (mean age 48.2 +/- 13.3 years, five males) were studied by means of I-123-MIBG single photon emission computed tomography (SPECT). A quantitative analysis of all scans was performed. All scans of the healthy volunteers show a uniform tracer uptake with sometimes slightly decreased activity in the apex. (1) All patients with QTc greater than 440 msec (n = 5); (2) all, who had suffered from at least one episode of torsade de pointes, ventricular fibrillation (VF) or syncope (n = 5); and (3) all symptomatic patients with QTc prolongation (n = 4) have reduced or abolished (P less than 0.02) MIBG uptakes in the inferior and inferior septal parts of the left ventricle (congenital myocardial sympathetic dysinnervation [CMSD]). Additionally, one female without symptoms or QTc prolongation (LQT) shows an abnormal MIBG SPECT similar to the one of her daughter, who has LQT and symptoms. One male without LQT, who had suffered from VF shows CMSD similar to his father, who has LQT, but no symptoms. All members of the families with normal MIBG SPECTs have neither LQT nor symptoms. In all families CMSD fulfills the criteria of autosomal-dominant inheritance. Normal QTc-interval predicted only in 57% normal cardiac sympathetic innervation in the present LQTS families. Therefore, quantitative I-123-MIBG SPECT enables to identify myocardial sympathetic dysinnervation as structural defect in LQTS. CMSD is associated with and without LQT and presents a pattern of autosomal-dominant inheritance. LQT at rest or during exercise was specific (100%), but less sensitive (63%) in the assessment of CMSD than I-123-MIBG SPECT.     

Inhibitory activity of IL-6 on malaria hepatic stages

Addition of recombinant interleukin-6 (IL-6) to Plasmodium yoelii hepatic cultures resulted in a specific dose-dependent inhibition of parasite development. Time course experiments showed that, without any direct effect on free sporozoites, IL-6 exerts its action during both the early phase of infection and during the subsequent maturation of the schizonts. Elicitation of the oxidative burst appears to be one mechanism by which IL-6 interferes with the development of hepatic phase. Catalase and superoxide dismutase, two scavengers of hydrogen peroxide and superoxide anions, reversed the IL-6 mediated parasiticidal activity.     

Asymptomatic Left Ventricular Malposition of a Transvenous Pacemaker Lead Through a Sinus Venosus Defect: Follow-up Over 17 Years

The case of a woman with an asymptomatic transvenous left ventricular endocardial pacemaker lead is presented. The chest X ray and the electrocardiogram suggested pacemaker catheter malposition. By two-dimensional echocardiography, the pacemaker lead was shown to cross from the left atrium through the mitral valve and implant in the left ventricular endocardium. The underlying sinus venosus defect and the passage of the electrode through this interatrial communication were directly visualized by transesophageal echocardiography. No thrombotic material attached to the lead was detected corresponding to the patient's uneventful course for surprisingly more than 17 years without evidence of past or present neurological deficiencies or of peripheral embolic phenomena. Thus, no operative correction was performed. Warfarin sodium therapy, however, was initiated.     

Transesophageal Echocardiography in Candidates for Percutaneous Balloon Mitral Valvuloplasty

Prior to percutaneous balloon mitral valvuloplasty (PBMV), mitral valve morphology and the presence of left atrial thrombi are usually evaluated by transthoracic two-dimensional and Doppler echocardiography (TTE). This study analyzes the impact of transesophageal echocardiography (TEE) in addition to TTE on the selection of candidates considered for PBMV for mitral stenosis. Seventy-five patients with severe mitral stenosis who were considered as appropriate candidates for PBMV based on TTE findings were studied. In 19 (25%) patients, TEE revealed findings that were essential for PBMV but were missed by TTE: left atrial thrombi (n = 14; including 13 in left atrial appendage), right atrial thrombus (n = 1), incomplete cor triatriatum (n = 1) and mitral valve vegetation (n = 1). In two other patients, a left atrial thrombus had been suspected by TTE but could be excluded by TEE. TEE and TTE revealed similar scores of thickening, calcification, and mobility of the mitral valve. Compared to TTE, thickening of the subvalvular apparatus was graded lower using horizontal plane TEE due to shadowing by the mitral valve (echo score 1.8 ± 0.8 vs 1.4 ± 0.7; P < 0.05) whereas results from longitudinal plane TEE were similar to TTE findings. The data show that due to the high prevalence of left atrial thrombi, TEE should be performed in addition to TTE in all patients prior to PBMV.     

Splenogonadal fusion: Report of a case and review of the literature

We report a case of splenogonadal fusion masquerading as a testicular tumor and review the etiology, the pathogenesis and the management of this rare disease. A 20-year-old male patient presented with clinical and radiological findings of a left testicular mass for which he underwent a left radical inguinal orchidectomy. Histopathology of the removed testicle revealed no tumor. The gonad was fused to ectopic splenic tissue, the later forming a distinct encapsulated mass attached to the lower pole of the testicle inside the tunica vaginalis. Splenogonadal fusion, although a rare condition, may account for a non-malignant testicular mass and should be suspected in young patients with other congenital anomalies.     

Influence of Body Position on Defibrillation Thresholds of Nonthoracotomy Implantable Defibrillators:

DFT of Nonthoracotomy Defibrillators. Introduction : Defibrillation thresholds (DFTs) usually are determined with the patient in the supine position. However, patients may be in the upright position when a shock is delivered during follow-up, which may explain some first shock failures observed clinically. This study investigated whether body posture affects defibrillation energy requirements of nonthoracotomy implantable cardioverter defibrillators with biphasic shocks.
Methods and Results : Using a step up-down protocol, DFTs were compared intraindividually in 52 patients ("active-can" systems in 41 patients, two-lead systems in II patients) for the supine and upright positions as achieved by a tilt table. The mean DFT was 7.3 ± 4.2 J in the supine versus 9.2 ± 4.8 J in the upright position (P = 0.002). Repeated comparison in reversed order 3 months after implantation in 22 patients revealed thresholds of 6.2 ± 2.5 J (supine) versus 8.4 ± 3.7 J (upright; P < 0.03) 1 week and 4.4 ± 2.4 J (supine) versus 6.2 ± 4.1 J (upright; P < 0.04) 3 months after implantation. DFTs decreased significantly for both body positions from 1 week to 3 months after implantation (P < 0.04).
Conclusion :(I) DFTs for biphasic shocks delivered by nonthoracotomy defibrillators are higher in the upright compared to the supine body position. (2) Differences remain significant 3 months after implantation. For both body positions, DFT decreases significantly from 1 week to 3 months after implantation. These findings have important implications for programming first shock energy to lower than maximal values or for development of devices with lower maximal stored energy.     

Cryoballoon Pulmonary Vein Isolation with Real-Time Recordings from the Pulmonary Veins

Introduction: Cryoballoon (CB) ablation represents a novel technology for pulmonary vein isolation (PVI). We investigated feasibility and safety of CB-PVI, utilizing a novel spiral catheter (SC), thereby obtaining real-time PV potential registration.
Methods: Following double transseptal puncture, a Lasso catheter (Biosense Webster, Diamond Bar, CA, USA) and the 28 mm CB were positioned within the left atrium. A novel SC (Promap, ProRhythm Inc., Ronkonkoma, NY, USA) was inserted through the lumen of the CB allowing PV signal registration during treatment. Time to PV conduction block was analyzed. If no stable balloon position was obtained, the SC was exchanged for a regular guide wire and PV conduction was assessed after treatment by Lasso catheter.
Results: In 18 patients, 39 of 72 PVs (54%) were successfully isolated using the SC. The remaining 33 PVs were isolated switching to the regular guide wire. Time to PV conduction block was significantly shorter in PVs in which sustained PVI was achieved as compared to PVs in which PV conduction recovered within 30 minutes (33 ± 21 seconds vs 99 ± 65 seconds). In 40 PVs, time to PV conduction block was not obtained because of: (1) PVI not being achieved during initial treatment; (2) a distal position of the SC; or (3) isolation with regular guide wire. No procedural complications occurred.
Conclusion: Visualization of real-time PV conduction during CB PVI is safe, feasible, and allows accurate timing of PVI onset in a subset of PVs. Time to PV conduction block predicts sustained PVI. However, mechanical properties of the SC need to be improved to further simplify CB PVI.