Acute alcohol does not impair attentional inhibition as measured with Stroop interference scores but impairs Stroop performance.

RATIONALE: Inhibition is a core executive function and refers to the ability to deliberately suppress attention, behavior, thoughts, and/or emotions and instead act in a specific manner. While acute alcohol exposure has been shown to impair response inhibition in the stop-signal and Go/NoGo tasks, reported alcohol effects on attentional inhibition in the Stroop task are inconsistent. Notably, studies have operationalized attentional inhibition variably and there has been intra- and inter-individual variability in alcohol exposure. OBJECTIVE: This study aimed to examine the acute effects of alcohol on attentional inhibition, considering previous limitations. METHODS: In a single-blind, cross-over design, 40 non-dependent participants with a medium-to-high risk drinking behavior performed a Counting Stroop task (CST) under a baseline and an arterial blood alcohol concentration (aBAC) clamp at 80 mg%. Attentional inhibition was assessed as the alteration of reaction times (RT), error rates (ER), and inverse efficiency scores (IES) between incongruent and congruent trials (interference score). Stroop performance was also assessed regardless of trial-type. RESULTS: Compared to saline, acute alcohol exposure via an aBAC clamp did not affect CST interference scores but increased RTs and IES in both incongruent and congruent trials. CONCLUSIONS: Attentional inhibition (Stroop interference score) was not impaired by clamped moderate alcohol exposure. Acute alcohol impaired Stroop performance evidenced by a general increase in response times. Our findings suggest that response and attentional inhibition do not share the same neurocognitive mechanisms and are affected differently by alcohol. Results could also be explained by automated behaviors known to be relatively unaffected by acute alcohol.

Interconnected electrocatalytic Pt-metal networks by plasma treatment of nanoparticle-peptide fibril assemblies.

Noble metal catalysts possess outstanding catalytic behaviors in organic reactions, photocatalysis, electrocatalysis and many other applications. Peptide fibrils are used for the controllable nanostructuring of metal nanoparticles with specific sizes, shapes and high-surface area structures. The degradation of these fibrils with O2-plasma yields interconnected networks of nanoparticles, similar to metallic nanowires. Herein, platinum nanoparticles (Pt-NPs) were synthesized by reduction using VUV excimer radiation. The particle size was characterized by dynamic light scattering (DLS). Due to agglomeration, the metal nanoparticles were stabilized using poly(vinyl pyrrolidone) (PVP) and the same synthesis procedure. The influence of the polymer PVP molecular weight (M wt), PVP concentration (C p) and VUV irradiation time on platinum nanoparticle size was investigated. Small (2-3 nm) Pt-NPs are formed in the case of PVP with M wt = 10 000 g mol-1. With increasing PVP M wt, decreasing PVP concentration and shorter irradiation times, larger sized nanoparticles appear. The applicability of templated platinum nanoparticles, both the PVP-stabilized and non-stabilized Pt-NPs, immobilized via electrostatic interactions on the solid phase-synthesized aniline-GGAAKLVFF (AFP) peptide fibrils was investigated to serve as possible electrode material. The plasma treatment of the nanoparticle-fibril-assemblies was also studied as a novel technique. The Pt-NPs-AFP fibrils and the PVP-stabilized-Pt-NPs-AFP fibrils nanohybrids were employed to modify electrodes and then subjected to O2-plasma treatment. These O2-plasma treated/modified electrodes exhibited high electrocatalytic activities towards oxygen reduction in cyclic voltammetry measurements. Thus, the aforementioned nanocomposites hold great potential for polymer electrolyte fuel cells and other electrochemical applications in miniature devices and microfluidic chips.

[MALDI mass spectrometry of the meniscus. Objectification of morphological findings]. / MALDI-Massenspektrometrie am Meniskus. Objektivierung morphologischer Befunde.

BACKGROUND: The classification of meniscal lesions requires correlation with clinical data. For the standardization of histopathology reports a discrimination between normal, low-grade lesions and high-grade lesions is feasible. This classification can be further specified using other methods. MATERIAL AND METHODS: Formalin-fixed, paraffin-embedded specimens of meniscal tissue from 68 patients were analyzed by matrix-assisted laser desorption ionization (MALDI) imaging. RESULTS: The classification of meniscal lesions and differentiation between low-grade and high-grade and acute versus non-acute degeneration is possible by determination of the differential expression of mass-to-charge ratios by statistical comparisons using the P-value from combined Wilcoxon and Kruskal-Wallis (PWKW) tests and a predefined average two-fold difference in intensity. CONCLUSION: The concept of a "meniscus report" is introduced for documentation of meniscus tissue specimens integrating histological, histochemical and proteomic data, thereby specifying the degree of degeneration and the assessment of acute or non-acute lesions. Mass spectrometry contributes to an objective histopathology report. An advisory opinion should always be based on close correlation of clinical and morphological evaluations.

Spatial integration in polarization-sensitive interneurones of crickets: a survey of evidence, mechanisms and benefits.

Many insects exploit the polarization pattern of the sky for compass orientation in navigation or cruising-course control. Polarization-sensitive neurones (POL1-neurones) in the polarization vision pathway of the cricket visual system have wide visual fields of approximately 60 degrees diameter, i.e. these neurones integrate information over a large area of the sky. This results from two different mechanisms. (i) Optical integration; polarization vision is mediated by a group of specialized ommatidia at the dorsal rim of the eye. These ommatidia lack screening pigment, contain a wide rhabdom and have poor lens optics. As a result, the angular sensitivity of the polarization-sensitive photoreceptors is very wide (median approximately 20 degrees ). (ii) Neural integration; each POL1-neurone receives input from a large number of dorsal rim photoreceptors with diverging optical axes. Spatial integration in POL1-neurones acts as a spatial low-pass filter. It improves the quality of the celestial polarization signal by filtering out cloud-induced local disturbances in the polarization pattern and increases sensitivity.

Succinylcholine metabolite succinic acid alters steady state activation in muscle sodium channels.

BACKGROUND: Animal experiments revealed that succinylcholine produced masseter muscle rigidity and activated myotonic discharges despite neuromuscular blockade with a nondepolarizing blocker. These results suggest that either succinylcholine or its metabolites might interfere directly with voltage-operated ion channels of the sarcolemma. The aim of this study was to examine effects of one product of succinylcholine hydrolysis, succinic acid, on voltage-gated muscle sodium (Na+) channels. METHODS: Alpha subunits of human muscle sodium channels were heterologously expressed in HEK293 cells. Activation of Na+ currents was examined applying standard whole-cell voltage-clamp protocols in the absence (control and washout) and presence of succinic acid in different concentrations (0.05-10 mm). RESULTS: Succinic acid shifted the midpoints of steady state activation plots in the direction of more negative test potentials, indicating that channels open during smaller depolarizations in the presence of the drug. The maximum amount of the negative shift in 10 mm succinic acid was -6.3 +/- 1.7 mV; the EC50 for this effect was 0.39 mm. In addition, succinic acid (10 mm) significantly enhanced maximum currents after depolarizations with respect to a series of control experiments. CONCLUSION: Succinic acid facilitates voltage-dependent activation in muscle sodium channels in vitro. This might lead to muscle hyperexcitability in vivo.

[Psychotherapy in general practice of physicians and psychologists]. / Psychotherapie in der Praxis niedergelassener Arzte und Psychologen.

This study tries to reveal the epidemiology of outpatient psychotherapy in practices in a defined northern area of Germany (Schleswig-Holstein, 2.66 Mill. inhabitants) by a postal questioning of all medical (n = 242) and psychological (n = 45) psychotherapists registered. Psychotherapy was defined as enclosing at least 10 meetings. 54.7% of the questionnaires were returned to us. An analysis on this database showed that 8310 adult patients were psychotherapeutically treated within one year (0.3% of the population). On the base of different epidemiological studies the treatment prevalence widely differed from 3.9 to 31.9%. The majority of diagnoses were reactive disorders or neuroses (52.8%) and psychosomatic disorders (24.3%). Patients out of middle and upper social classes, with higher educational levels, and from urban areas (> 100 000 inhabitants) were more likely to be treated than others. This trend was significantly more apparent in psychologists than in physicians.

[Relation of uteroplacental hemodynamics and fetal respiratory behavior in pregnancy with threatened premature labor or intrauterine retardation]. / Beziehungen zwischen uteroplazentarer Hämodynamik und fetalem respiratorischem Verhalten bei Schwangerschaft mit drohender Frühgeburt oder intrauteriner Retardierung.

The results of uteroplacental hemodynamics obtained by nuclear medicine were correlated with the corresponding antepartal and intrapartal cardiotocographic findings in 52 patients with preterm labor and in 53 patients with intrauterine-growth-retarded fetuses. With the existence of continued disturbance in pregnancy the relationship between primary maternal hemodynamic disorders and decreased fetal respiratory performance is already evident antepartum and unambiguously intrapartum. The dependence of the antepartal cardiotocographic findings on therapeutical improvements in perfusion is of clinical relevance.

A new method for the classification of subvigil stages, using the Fourier transform, and its application to sleep apnea.

An online classification for two-second segments of the EEG is developed. Based on the calculation of a norm and three characteristic frequencies the automatic classification shows satisfactory agreement with visual classification. The influence of the Fourier phase spectra is discussed. Trajectories in the parameter space are introduced. The automatic classification was applied to patients with a pronounced sleep-wake disorder and proved to be valuable in the diagnosis of a disturbed sleep structure.

[Therapy of suspected intrauterine fetal retardation]. / Zur Therapie bei Verdacht auf intrauterine fetale Retardierung.

In a randomized prospective study, performed on 45 pregnancies with clinical and sonographic suspicion for intrauterine fetal growth retardation, examinations were done to evaluate the therapeutic effect of bed rest and of additional daily administered glucose infusions or oral galactose applications respectively on the fetal growth, the hemodynamic, respiratory and endocrine insufficiency of the materno-feto-placental unit as well as selected biochemical parameters of the umbilical blood. There is no positive therapeutic effect, either on the impaired endocrine partial function nor on the reduced respiratory function of the feto-placental unit. It is obvious, that despite the improvement of the nutritional supply of the fetus and the revival of the regular fetal growth, the previous lack of fetal growth can not be altered. This can be demonstrated in all three therapeutic groups due to the fact of a resulting high hypotrophy-rate of the newborns. The results prove that the additional supply of the fetus with glucose or galactose does not remarkably improve the therapeutic effectivity as opposed by strict bed rest alone.

[Hyperlactacidemia in intestinal ischemia. II. Experimental principles]. / Hyperlactatämie bei Darmischämie. II. Experimentelle Grundlagen.

Looking for an early laboratory parameter in diagnosis of acute bowel ischemia, we caused an acute ischemia of the rabbit bowel by clamping the superior mesenteric artery. The blood tests showed a significant increase of lactate during 80 min of ischemia. This lactate excess continued nearly 40 min after revascularization of the bowel, but disappeared nearly completely after 90 min. Neither the laparotomy without clamping the superior mesenteric artery, nor the experimental clamping of the a. femoralis communis led to a lactacidemia. The lactacidemia in our experiments is compared with clinical observations in acute bowel diseases and vascular surgery with clamping of the aorta. The reasons of the specific high lactate excess of bowel ischemia are discussed. The fast increase of the lactate following mesenteric vascular occlusion and the rapid normalisation of lactate after recovery demonstrate a sensitive method in the diagnosis and controlling the treatment of acute bowel diseases with an insufficient blood supply.

[Premature labor in gestosis]. / Frühgeburtlichkeit bei Gestose.

796 pregnancies complicated by preeclampsia and 1,299 pregnancies without toxemia of the years 1981 to 1985 have been compared with regard to prematurity. Prematurity rates were 12.4 respectively 13.8 per cent, hypotrophy rates were 20 resp. 13 per cent, acidosis morbidity was 75 resp. 20 per cent and Apgar values below 8 were 63 resp. 24 per cent. Morbidity rate of respiratory distress syndrome was 8 resp. 12 per cent, of sepsis 2 resp. 7 per cent, intrauterine death rate 5 resp. 2 per cent, but survival rate overall was 93 resp. 90 per cent. Prematurity was influenced by severity of preeclampsia, time of onset and prenatal care. Prolongation of pregnancy by tocolysis is possible principally, but influenced in its effect by maternal and fetal symptoms and the necessity of termination of pregnancy by these factors.

[Hemodynamic placental insufficiency and its therapeutic modification in threatened premature labor]. / Hämodynamische Plazentainsuffizienz und ihre therapeutische Beeinflussung bei drohender Frühgeburt.

The authors are involved in a study in the field of nuclear medicine aimed at further clarifying the connection between premature delivery and placental insufficiency. They are particularly concerned with uteroplacental perfusion at the time when a trend is emerging toward premature birth, and with ways of treating this by exclusive therapy using betamimetics and/or additional maternal oxygen inhalation/additional maternal transcutaneous dorsal nerve stimulation (TNS). The significantly longer half-life periods of activity increase found at the time of hospitalization similar to pregnancies with intra-uterine fetal retardation, as compared with a normal control group, are interpreted as expressing a hemodynamic placental insufficiency and a risk of premature delivery. In contrast to exclusive betamimetic therapy, additional O2 inhalation/additional TNS significantly shorten the half-life period both in short-time and long-time tests. The better therapeutic effect on uteroplacental perfusion in cases of imminent premature delivery which is thus demonstrated can be seen also in an improved respiratory condition of the fetus as shown in a cardiotocogram. From a clinical point of view, the authors call attention to the clearly prolonged pregnancy periods regardless of the duration of gestation, at the time when a trend is emerging toward premature birth, as compared with exclusive betamimetic therapy, the duration of tocolysis/amount of betamimetic applied being the same.

[Therapeutic efforts and prenatal modification of selected disordered fetomaternal relations]. / Therapeutische Bemühungen um präpartale Beeinflussung ausgewählter gestörter fetomaternaler Beziehungen.

Based on the current view about disturbances of the feto-materno-placental unit we examined 37 women with suspected intrauterine fetal growth retardation and 12 women with threatened premature labor and looked for possibilities of antenatal therapeutic influence of nutritive, respiratory, endocrine and hemodynamic insufficiency. In a randomized study we can prove a normal increase of the distance between symphysis pubis and fundus as well, as the biparietal diameter not only following bedrest but also following bedrest with additional intravenous infusion of glucose respectively oral application of galactose. The high rate of hypotrophic babies is no argument against a positive influence on nutritive insufficiency, but the acquired retardation can not be compensated totally. Neither a positive influence on the endocrine insufficiency nor the moderate respiratory one could be found. As well by maternal transcutaneous nerval stimulation as by maternal oxygen inhalation an oral long-term tocolysis we can demonstrate a considerable improvement of the uteroplacental perfusion measured with isotopes. These positive aspects are basis for further investigations. An important supposition to a successful therapy remains an early diagnosis.

[Methodologic observations on the quantitative determination of uteroplacental perfusion]. / Methodische Betrachtungen zur quantitativen Bestimmung der uteroplazentaren Perfusion.

The determination of utero-placental perfusion by isotop methods is examined. Possible errors are discussed. The determination of placentaperfusion on the basis of the activity maximum is proposed as an alternative to evaluation methods used until now.