[Atrioventricular nodal reentry tachycardia in children: curative treatment by high frequency catheter ablation]. / AV-Knoten-Reentry-Tachykardien im Kindesalter: Kurative Behandlung durch Hochfrequenzstromablation.

BACKGROUND: Atrioventricular nodal reentrant tachycardia (AVNRT) is one of the most common forms of supraventricular tachycardia in the pediatric population. PATIENTS AND METHODS: 41 children with a mean age of 9.6 (3.7-16) years with recurrent atrioventricular nodal reentrant tachycardia (AVNRT) refractory to medical treatment (n = 38) and recurrent syncope (n = 3) underwent electrophysiologic (EP) study. In all patients dual AV-nodal physiology could be demonstrated during EP study and typical form of AVNRT (mean heart rate 220/min) could be induced by programmed atrial stimulation. A steerable 7 F ablation catheter was placed at the inferoparaseptal region of the tricuspid valve annulus close to the orifice of the coronary sinus with the intention to record a late fractionated local atrial electrogram during sinus rhythm. Starting at this point radiofrequency current (500 kHz) with a target temperature of 70 degrees C was delivered with the intention to ablate the slow pathway. If a slowly accelerated junctional rhythm (< 120/min) occurred during energy discharge, programmed atrial stimulation was repeated. Otherwise radiofrequency current was delivered step by step up to a septal position next to the tricuspid valve annulus. Slow pathway ablation was defined as lack of evidence of dual AV nodal pathways during repeated atrial stimulation. Slow pathway modulation was defined as maximal one atrial echoimpulse after ablation. RESULTS: The number of energy applications ranged from 1-19 (median 6). In 35/41 patients slow pathway ablation could be achieved; in six patients the slow pathway was modulated. In none of the patients permanent high grade AV block was observed. During follow-up (mean 4.1 years) two patients had a recurrent episode of AVNRT after slow pathway modulation. All other patients are still free of AVNRT without medical treatment. CONCLUSION: Selective radiofrequency current ablation/modulation of the slow pathway is a safe and curative treatment of AVNRT in young patients.

The effects of a benzodiazepine receptor antagonist beta-carboline ZK-93426 on scopolamine-induced impairment on attention, memory and psychomotor skills.

The effects of a single dose of scopolamine alone and in combination with ZK 93426 (a beta-carboline antagonist at the GABAA/BZ receptor complex with weak inverse agonist activity) were tested in two studies. In one study (study 1) the emphasis of enquiry was on different stages of information processing measured by a psychometric battery; in the second study (study 2) performance at different stages of memory and psychomotor abilities was tested and electroencephalogram recordings and video-tracking were also performed. Each study consisted of two parts, part I in which scopolamine (0.5 mg; 1 ml) or placebo were administered subcutaneously, and part II in which scopolamine (0.5 mg; 1 ml) was administered subcutaneously followed by an intravenous injection of ZK 93426 (0.04 mg; 0.04 ml/kg) or placebo. Thirty-six volunteers, who were randomly allocated to receive one of the two treatments (n = 18 per treatment), participated in each part. In study 1 attention was measured by a continuous attention task and a rapid information processing task, vigilance was measured by a visual vigilance task, and working memory and reasoning were evaluated by a logical reasoning task. A visual memory task was also included to measure acquisition and retention. In study 2 acquisition and short term storage and retrieval were measured by a word lists-Buschke restricted reminding procedure, and retention was tested by delayed recall and recognition. Psychomotor performance was assessed by measuring tapping speed (related to gross motoric abilities) and a pegboard task (related to fine motoric abilities). A task to measure working memory, the Pauli test, was also included. In study 1 scopolamine significantly impaired performance in the attentional and vigilance tasks (P < 0.05), but there was no effect in the logical reasoning task main measurements of time and accuracy. In study 2, scopolamine also impaired performance in the psychomotor tasks (P < 0.05) and the Pauli test. ZK 93426 partially antagonised most of the effects of scopolamine on memory and attention, suggesting that an interaction between the GABA-ergic and cholinergic systems is reflected in measurements of both attention and memory. In general a dissociation was found in the effects of scopolamine on memory, i.e. scopolamine impaired performance during all acquisition measurements but left retention unaffected.

Analytical approaches relating genetic evolutionary pathways to prognostic factors.

Human solid tumors accumulate multiple genetic abnormalities as they progress to advanced stages. Multiparameter flow cytometry measurements of individual cells within each tumor may be useful in describing the genetic pathways taken by individual tumors during the course of their genetic evolution. In this paper, we analyzed correlated cell-by-cell measurements of cell DNA content, HER-2/neu protein content, and ras protein content obtained by multiparameter flow cytometry studies of primary breast cancers from 92 patients. These laboratory findings were correlated with established clinical prognostic factors for each patient at the time of diagnosis, using a stepwise multiple analysis of variance (MANOVA). The stepwise MANOVA successively splits a group of patients into two mutually exclusive dissimilar groups, selecting the clinical prognostic factor that is most effective in doing so. Using this criterion, formation of the first three groups that were judged most dissimilar on the cytometry parameters was based on the number of positive nodes at the time of diagnosis. We show that ploidy, HER-2/neu protein content, and ras protein content, as measured by multiple parameter flow cytometry, are correlated with nodal status and other known clinical prognostic factors. The cell-by-cell multiparameter data suggest that for some individual tumors there are multiple genetic evolutionary pathways. Multiple genetic evolutionary pathways are also suggested by the MANOVA analysis. Focusing on the identification and analysis of genetic evolutionary pathways within individual tumors and across patients appears to offer a promising approach for defining the prognosis of early cancers.

Measures of memory and information processing in elderly volunteers.

A screening study was carried out in normal elderly volunteers to determine 1. their scores in measures of memory and information processing 2. how the measures correlate with sample characteristics 3. how the measures correlate with each other and with the EEG. We report here on 111 subjects, 56 women and 55 men aged 53-77 years (63.9 +/- 6.8) with average intelligence (Coloured Progressive Matrices CPM 26.7 +/- 5.1). In the C-normed measures of the word list from the Nuremberg Geriatric Inventory (NGI) our sample scored better than average (immediate recall of words C = 7.5, delayed recall of words C = 8.2; mean C = 5). The sample even attained ceiling scores in the test of recognition. The sample likewise had a better than average speed in a color-word test (CWT) of focused attention similar to the Stroop test (e.g., reading C = 7.5, color-naming C = 6.7, interference task C = 6.3) and in the ZVT trail-making test (C = 7.0). In contrast, speed-free focused attention was only average (C = 5.2 and C = 5.5). The following sample characteristics correlated with test measures of memory and information processing (p less than 0.01): age negatively with immediate recall, trail making, incidental episodic memory, focused attention, speed in the CWT; intelligence correlated positively with 10-min adding which relies on working memory (Pauli test) and immediate recall; education correlated positively with delayed recall, visual memory performance in a figures test, immediate recall, and reading speed in the CWT; occupation correlated positively with figures test performance; exercise of profession correlated positively with incidental episodic memory and immediate recall. Age and occupation correlated more with motor measures than with cognitive measures (pegboard, 1 min tapping at maximal speed). Sex had no bearing on memory characteristics, but did on tracking (men better) and color-naming performance in the CWT (women better). Of the semiluxuries, only regular alcohol consumption showed a relationship with the test measures (negatively with color-naming speed, immediate recall, and pegboard performance). Analysis of memory and information processing measures revealed no correlations (r greater than or equal to 0.40) between memory measures from the word list, Pauli test, figures test, and learning. Measures of the CWT correlated with Pauli test and pegboard. ZVT score was the variable with the most correlations (CWT, Pauli test, pegboard). A factor analysis with a reduced set of variables should further clarify the inner structure of our subject's performance.(ABSTRACT TRUNCATED AT 400 WORDS)

Anterograde and retrograde amnesia after lormetazepam and flunitrazepam.

In a pharmacopsychological study, memory impairments after single oral doses of benzodiazepines or placebo were investigated in 40 healthy men aged 20-40 years. The study was designed as a double-blind and placebo-controlled trial. Four independent groups of 10 subjects randomly received either 1 mg lormetazepam, 2 mg lormetazepam, 2 mg flunitrazepam, or placebo. The tests consisted of word lists, picture tests, and syllable pairs (consonant-vowel-consonant trigrams). Tests were performed before drug ingestion, and 1, 2, 3, and 5 h after application. Different test versions were used on each occasion. The target variables were immediate recall (after presentation and a 10-s distraction task) and delayed recall and recognition (after 30 min). Recognition was also tested after 24 h for all five versions. A distinction must be made between anterograde amnesic effects and retrograde amnesic effects. The greatest anterograde memory impairments were observed after 2 mg flunitrazepam (p less than 0.05). Lormetazepam 2 mg produced less marked impairments than flunitrazepam. Results after 1 mg lormetazepam did not differ from those after placebo. Performance in the memory tests was better under benzodiazepines than under placebo as regards material learned before drug ingestion, i.e. the benzodiazepines had not negative retrograde amnestic effects, but rather "promnesic" effects. The results suggest that the extent of the benzodiazepines' amnesic effects--both negative (anterograde) and positive (retrograde)--depends on the dosage and type of substance.