Toward a formal theory of proactivity.

Beyond merely reacting to their environment and impulses, people have the remarkable capacity to proactively set and pursue their own goals. The extent to which they leverage this capacity varies widely across people and situations. The goal of this article is to propose and evaluate a model of proactivity and reactivity. We proceed in three steps. First, we model proactivity in a widely used cognitive control task known as the AX Continuous Performance Task (AX-CPT). Our theory formalizes an important aspect of proactivity as meta-control over proactive and reactive control. Second, we perform a quantitative model comparison to identify the number and nature of meta-control decisions that are involved in the regulation of proactive behavior. Our findings suggest that individual differences in proactivity are governed by two independent meta-control decisions, namely deciding whether to set an intention for what to do in a future situation and deciding whether to recall one's intentions when the situation occurs. Third, we test the assumptions and qualitative predictions of the winning model against data from numerous experiments varying the incentives, cognitive load, and statistical structure of the task. Our results suggest that proactivity can be understood in terms of computational models of meta-control. Future work will extend our models from proactive control in the AX-CPT to proactive goal creation and goal pursuit in the real world.

[Clinical practice of systemic lysis in prehospital resuscitation. Success and complication rates]. / Klinische Praxis der systemischen Lyse unter prähospitaler Reanimation. Erfolgs- und Komplikationsraten.

BACKGROUND: Systemic thrombolysis was introduced as the sole prehospital treatment option in patients with cardiac arrest in the setting of acute myocardial ischemia or pulmonary embolism; however, it remains the subject of discussion. PATIENTS AND METHODS: A total of 194 patients with sudden prehospital cardiac arrest were included in this retrospective case control study. Of these patients, 96 in whom circulatory arrest due to cardiac disease (pulmonary artery embolism or myocardial ischemia) was suspected underwent thrombolytic treatment and were compared to the remaining 98 patients that did not undergo thrombolytic therapy. In addition to the circumstances of circulatory arrest, the course and success of resuscitation, as well as in-hospital course (including bleeding complications), overall survival and neurological outcomes were compared. RESULTS: There were no significant differences between patients with or without thrombolysis in terms of the circumstances of cardiac arrest. Patients that received thrombolytic treatment were significantly younger and were more frequently treated with anticoagulants, platelet aggregation inhibitors and amiodarone. They also received higher doses of epinephrine and arrived at hospital under ongoing resuscitation significantly more frequently. A trend toward more prehospital return of spontaneous circulation (ROSC) following thrombolytic treatment was seen in the entire cohort. However, patients pre-treated with acetylsalicylic acid and heparin did not show better prehospital ROSC rates as a result of additional thrombolytic therapy. Significant differences in terms of bleeding complications or the need for blood transfusion could not be seen due to the small number of patients. DISCUSSION: The indication for systemic thrombolysis in the context of prehospital resuscitation should remain restricted to patients with clear symptoms of acute pulmonary embolism or recurrent episodes of ventricular fibrillation in the setting of acute myocardial infarction. Due to a lack of evidence, systemic thrombolysis should not be used as a treatment of last resort in younger patients with persistent ventricular fibrillation.

Effect of transcoronary ablation of septal hypertrophy on clinical outcome in hypertrophic obstructive cardiomyopathy associated with atrial fibrillation.

BACKGROUND: Relatively few reports on the clinical impact of atrial fibrillation (AF) in hypertrophic obstructive cardiomyopathy (HOCM) are available. The aims of our study are to report the effect of transcoronary ablation of septal hypertrophy (TASH) on clinical outcome in HOCM associated with AF and to evaluate the influence of AF on symptoms and quality of life in HOCM. PATIENT AND METHODS: In 80 consecutive patients (38 f, mean age 56 +/- 17 years) with severely symptomatic HOCM referred for interventional treatment, we analyzed the prevalence of AF based on 240 Holter ECG recordings and patients' history, retrospectively. Symptoms, quality of life, number of hospital admissions and hemodynamic performance were obtained in all patients before and after TASH. Mortality was additionally investigated by letter and telephone contact. RESULTS: The overall prevalence of AF was 29%. Paroxysmal AF was detected in 17 pts (21.3%), persistent AF in 5 pts (6.3%). Only 1 pt (1.3%) suffered from permanent AF. Symptoms due to AF were present in 52.6% of the AF patients. Quality of life score was markedly improved after TASH (15.9 +/- 3.8 vs. 20.7 +/- 3.8, p < 0.001) with no difference between sinus rhythm and atrial fibrillation. However, hospital admissions were more frequent in the AF group (0.85 +/- 1.84 vs. 0.28 +/- 0.81, p = 0.03) in 32 +/- 13 months. AF patients suffered more often from syncope before TASH (30 +/- 70% vs. 10 +/- 30%, p = 0.008). Two patients with sinus rhythm at baseline died after 32 +/- 13 months from cardiovascular cause. CONCLUSIONS: Atrial fibrillation is the major cardiac arrhythmia in severe HOCM. The majority of AF patients demonstrate AF specific symptoms. The paroxysmal type of atrial fibrillation dominates by far. Both patients with and without atrial fibrillation showed similar quality of life with marked improvement after TASH.

Transcoronary ablation of septal hypertrophy (TASH): a new treatment option for hypertrophic obstructive cardiomyopathy.

In 1991, our group started to develop a catheter interventional therapy for hypertrophic obstructive cardiomyopathy (HOCM). The new concept was proposed in 1994. It is based on the conventional PTCA technique with the aim of inducing an artificial myocardial infarction by instillation of 96% ethanol into the most proximally situated septal branch of the left anterior descending coronary artery. This leads to a subaortic contraction disorder with subsequent decrease of the intraventricular pressure gradient, shrinkage of the hypertrophied septal bulge and widening of the outflow tract ("therapeutic remodeling"). The subaortic defect is small and well demarcated as assessed by left ventricular angiography, transesophageal echocardiography and 18 F-glucose positron emission tomography. The term transcoronary ablation of septum hypertrophy (TASH) was suggested. Our patient cohort that now comprises 215 therapeutic procedures in 187 patients underwent a large variety of prospective studies (maximum follow-up 4.5 years) including invasive controls at regular intervals, investigation of hemodynamics at rest and at exercise, transesophageal and transthoracic echocardiography, Doppler echocardiography during bicycle exercise, electrophysiologic testing, Holter monitoring and measurement of myocardial metabolism and perfusion, assessment of microembolic events by transcranial Doppler sonography and histological examinations. This article gives an overview and reports our increasing experience in applying TASH. The following post-TASH findings were obtained: significant hemodynamic and clinical improvement at rest and at exercise, decrease of septum thickness, increase of outflow tract area and decrease of induced ventricular tachycardia. There were well-demarcated, histologically atypical subaortic myocardial defects, no microembolic events, abnormal early peak of infarct related enzymes, and no change of baroreflex sensitivity. Pre-/post-TASH evaluations of the patients should be based in particular on clinical symptoms correlated to the intraventricular gradient measured by bicycle exercise Doppler echocardiography and to outflow tract area as assessed by transesophageal echocardiography. Since 1994, as a roughly estimate, worldwide 1000 patients in 20 countries have been treated. According to published articles, abstract presentations and workshops, TASH consistently leads to a pronounced clinical and hemodynamic benefit for patients with HOCM. TASH has become an established technique. At least in centers with a high level of expertise, it is no longer experimental but a routinely performed alternative to surgical treatment for HOCM, i.e., the previous gold standard of therapy. Of course, patient outcome needs further careful clinical and prognostic evaluation. With respect to complications, TASH appears to be superior to surgery (transaortic septal myectomy) for HOCM. Like surgical treatment, TASH is currently indicated in critically ill patients with typical HOCM (subaortic form), who exhibit with drug refractory symptoms, including patients, who preferred DDD pacemaker therapy as a first therapeutic step but in whom this produced no subsequent clinical benefit.

[Methanol, isopropanol, n-propanol--endogenous formation affected by alcohol?]. / Methanol, Isopropanol, n-Propanol--endogene Bildung unter Athanoleinfluss?

Methanol, isopropanol and n-propanol are detected usually in blood samples during the determination of congeners. The ethanol-induces formation of methanol and isopropanol has been described formerly. Also little amount of n-propanol were detected in blood, which could not be reduced to the alcoholic beverages.

[Ethanol and isopropanol consumption]. / Athanol- und Isopropanolkonsum.

Drinking tests with isopropanol or isopropanol and ethanol, in which blood levels were measured over some hours, have not yet been described in literature. Pharmacokinetic parameters like decomposition rate, distribution volume or distribution factor were calculated. The results of these tests are discussed also in their reliance to clinical treatment of intoxications.

Urinary excretion of mutagens in smokers of cigarettes with various tar and nicotine yields, black tobacco, and cigars.

Frameshift mutagens were isolated and concentrated from smokers' urine employing a method recently described. Urine concentrates of the habitual smokers and non-smokers who smoked cigarettes with low-, medium-, and high tar/nicotine yields, RCN (Reduced Condensate and Nicotine; artificial cigarettes containing cotobacco materials), black tobacco, and cigars were tested for mutagenicity in the Salmonella/mammalian microsome assay using Salmonella typhimurium TA98. Non-smokers who smoked 5 and habitual smokers who smoked 10 cigarettes of various tar and nicotine yields excreted more mutagens in urine with low-tar cigarettes than with medium- or high-tar cigarettes. Consuming more than 10 cigarettes a day resulted in a higher urinary excretion of mutagens with medium-tar cigarettes than with high-tar cigarettes. Smoking 5 RCN cigarettes a day by habitual smokers resulted in a higher urinary excretion of mutagens than smoking 5 commercial brand of cigarettes. In contrast, smoking 10 RCN cigarettes resulted in a lower urinary excretion of mutagens than smoking 10 commercial brand of cigarettes. The highest mutagenic activity was found with the urine of a habitual black tobacco smoker. Smoking cigars by non-smokers resulted in a very weak mutagenic activity of urine.

Piracetam in alcoholic organic mental disorder: a placebo controlled study comparing two dosages.

The following paper presents an investigation of the efficacy of piracetam in alcoholic organic mental disorder. A double-blind placebo-controlled study design was used to compare 2 dosages of the substance (2 X 3 g vs. 2 X 12 g). Cognitive function was assessed on days 0, 7, 14, 28, 42. Analysis of the results from 24 patients showed a clear-cut amelioration of cognitive functions in all 3 treatment groups. No difference could be demonstrated between the administration of placebo and the lower dose of piracetam. Patients on the higher dose showed an earlier improvement on one of the tests, but the final scores were similar in all three treatment groups.

Isolation of frameshift mutagens from smokers' urine: experiences with three concentration methods.

Frameshift mutagens were isolated and concentrated from cigarette smokers' urine by the use of three different extraction methods; XAD-2 resin chromatography, chloroform and blue cotton extraction systems. The extracts were tested for mutagenicity in the Salmonella/mammalian microsome test employing Salmonella typhimurium TA98. By the use of XAD-2 resin chromatography, no clear correlation was found between urine mutagenicity versus number of cigarettes smoked and no detectable mutagenic activity was observed when fewer than four cigarettes a day were consumed. A clear correlation was found between urine mutagenicity versus number of cigarettes smoked when urine samples were extracted by the use of chloroform or blue cotton. Interference of free histidine in mutagenicity assays could be excluded.