Search Results - (Author, Cooperation:P. Leonard)

2018-01-30

Wiley-Blackwell

0007-1048

1365-2141

Medicine

2018-09-11

American Chemical Society (ACS)

0002-7863

1520-5126

Chemistry and Pharmacology

2013-08-30

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Adiposity ; Adult ; Bacteria/classification/genetics/*isolation & purification ; Biomarkers/*metabolism ; Body Mass Index ; Case-Control Studies ; Diet ; Dyslipidemias/microbiology ; Energy Metabolism ; Europe/ethnology ; European Continental Ancestry Group ; Female ; Gastrointestinal Tract/*microbiology ; Genes, Bacterial ; Humans ; Inflammation/microbiology ; Insulin Resistance ; Male ; *Metagenome/genetics ; Obesity/metabolism/microbiology ; Overweight/metabolism/microbiology ; Phylogeny ; Thinness/microbiology ; Weight Gain ; Weight Loss

2014-08-01

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Case-Control Studies ; Chronic Disease ; Diabetes Mellitus, Type 2/microbiology ; Feces/microbiology ; Gastrointestinal Tract/*microbiology ; Genetic Markers/genetics ; Health ; Humans ; Inflammatory Bowel Diseases/microbiology ; Liver Cirrhosis/*diagnosis/*microbiology ; *Metagenomics ; Microbiota/*genetics/*physiology ; Mouth/microbiology ; Phylogeny ; Reproducibility of Results

1749-6632

Blackwell Publishing Journal Backfiles 1879-2005

Natural Sciences in General

Electronic Resource

2024-10-21

Background: Alcohol consumption to facilitate social interaction is an important drinking motive. Here, we tested whether alcohol influences trust in others via modulation of oxytocin and/or androgens. We also aimed at confirming previously shown alcohol effects on positive affect and risk-taking, because of their role in facilitating social interaction. Methods: This randomized, controlled, within-subject, parallel group, alcohol-challenge experiment investigated the effects of alcohol (versus water, both mixed with orange juice) on perceived trustworthiness via salivary oxytocin (primary and secondary endpoint) as well as testosterone, dihydrotestosterone, positive affect, and risk-taking (additional endpoints). We compared 56 male participants in the alcohol condition (1.07 ± 0.18 per mille blood alcohol concentration) with 20 in the control condition. Results: The group (alcohol versus control condition) × time (before [versus during] versus after drinking) interactions were not significantly associated with perceived trustworthiness (η2 〈 0.001) or oxytocin (η2 = 0.003). Bayes factors provided also substantial evidence for the absence of these effects (BF01 = 3.65; BF01 = 7.53). The group × time interactions were related to dihydrotestosterone (η2 = 0.018 with an increase in the control condition) as well as positive affect and risk-taking (η2 = 0.027 and 0.007 with increases in the alcohol condition), but not significantly to testosterone. Discussion: The results do not verify alcohol effects on perceived trustworthiness or oxytocin in male individuals. However, they indicate that alcohol (versus control) might inhibit an increase in dihydrotestosterone and confirm that alcohol amplifies positive affect and risk-taking. This provides novel mechanistic insight into social facilitation as an alcohol-drinking motive.

Psychologie ; Psychology ; Trustworthiness; Oxytocin; Positive affect; Risk-taking; Social facilitation; Deutsche Version der Positive and Negative Affect Schedule PANAS (GESIS Panel) (ZIS 242) ; psychische Störungen, Behandlung und Prävention ; Psychological Disorders, Mental Health Treatment and Prevention ; Alkoholkonsum ; Trinkverhalten ; Vertrauen ; soziales Verhalten ; Risiko ; soziale Faktoren ; Interaktion ; Affektivität ; alcohol consumption ; alcohol consumption habits ; confidence ; social behavior ; risk ; social factors ; interaction ; affectivity

Zeitschriftenartikel, journal article

article

2004

Empirische Untersuchung ; Vergleich ; Kommunikation ; Lernforschung ; Lernprozess ; Unterricht ; Sprache ; Naturwissenschaften

Science education, Bd. 88 (2004) H. 3, S. 420-442, 0036-8326

English

book

1984

Sozialer Wert ; Soziale Norm ; Lehrerfortbildung ; Programmierung ; Unterrichtstechnologie ; Datenverarbeitung

English

book

1984

Programmierung ; Unterrichtstechnologie ; Mikrocomputer

English

article

1996

Erwachsenenbildung ; Frauenbildung ; Eswatini

Adult education and development, (1996) H. 47, S. 317-330, 0342-7633

English

article

2000

Schüler-Schüler-Interaktion ; Lernerfolg ; Schreiben ; Arbeitsauftrag ; Diskussion

Science education, Bd. 84 (2000) H. 5, S. 566-593, 0036-8326

English

article

1987

Soziale Bewegung ; Erwachsenenbildung ; Politische Erwachsenenbildung ; Konferenzschrift ; Internationale Konferenz ; Argentinien ; Buenos Aires ; Lateinamerika

Convergence, Bd. 20 (1987) H. 1, S. 40-50, 0010-8146

English

book

1987

Arbeitsgruppe ; Erwachsenenbildung

English

2018-08-04

MDPI Publishing

1424-8220

Chemistry and Pharmacology

Electrical Engineering, Measurement and Control Technology

1471-4159

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Abstract: We investigated the ability of N6-cyclohexyladenosine (CHA), a potent and selective agonist of the adenosine A1 receptor, to attenuate elevations of levels of extracellular hippocampal glutamate and glycine that result from episodes of transient global cerebral ischemia (TGCI). A total of 30 New Zealand white rabbits were randomly assigned to receive O (n = 5), 0.1 (n = 8), 1.0 (n = 6), 10 (n = 6), or 100 (n = 5) γM CHA. The drug was dissolved in artificial CSF (vehicle) and administered via a microdialysis probe placed stereotactically into the dorsal hippocampus. A second microdialysis probe placed into the contralateral hippocampus of each animal was perfused with vehicle alone. Ten minutes of TGCI was induced by neck tourniquet inflation and deliberate hypotension from O to 10 min. Microdialysissamples were collected as follows: every 20 min preischemia (at -80, -60, -40, -20, and 0 min); every 5 min during ischemia and in the immediate reperfusion period (at 5, 10, 15, and 20 min); and every 20 min for the remainder of the reperfusion period (at 40, 60, and 80 min). Samples were then analyzed for their concentration of glutamate and glycine by HPLC. Following 10 min of ischemia, glutamate levels increased to a peak of 3.28 pmn 0.55 times baseline and returned to preischemic levels by 40 min, i.e., during reperfusion. Glycine concentrations increased to 5.41 pmn 0.91 times over baseline and remained elevated for the duration of the study. Glutamate and glycine levels were converted to a release index, which was defined as the fractional increase (relative to levels just before ischemia) in amino acid concentration multiplied by time during ischemia and reperfusion. Regression analysis revealed a significant dose-dependent reduction in the glycine release index (p= 0.03) on the CHA-treated side. The contralateral side showed no such attenuation (p= 0.5). For glutamate, there was a nonsignificant tendency for CHA to reduce dose-dependently glutamate levels (p= 0.054), whereas the contralateral (vehicletreated) side showed no such tendency (p= 0.2). These results indicate that CHA (0.1–100 μM) has a dose-dependent attenuating effect on the periischemic increase in extracellular glycine levels. Elevated glycine levels may contribute to glutamate's neurotoxicity. It is uncertain to what degree this decrease in glycine levels by CHA may contribute to previously reported cerebral protection.

Electronic Resource

1471-4159

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Abstract: The present investigation using labeled pyruvate describes the regional distribution and kinetics of the monocarboxylic acid carrier at the blood–brain barrier of conscious rats. The experimental procedure involved the arterial injection of a single bolus of 200 μ1 containing [1-14C]pyruvate, [3H]water, and varying concentrations of unlabeled pyruvate into the common carotid via an indwelling externalized catheter. The hemisphere ipsi-lateral to the injection and rostral to the midbrain was removed and dissected into five regions. A kinetic analysis revealed no significant regional differences in Km values with an overall average of 1.37 mM. However, there was regional variation in the density of the monocarboxylic acid carrier as indicated by varied levels of the kinetic constant Vmax. The cortex showed the highest Vmax value of 0.42 ± 0.08 μmol/min/g whereas values for the caudate/putamen, thalamus/hypothalamus, and remaining portion of hemisphere ranged significantly lower at 0.22–0.27 μmol/min/g. The Vmax for the hippocampus was intermediate at 0.37 ± 0.12 μmol/min/g. The nonsaturable carrier described kinetically by KD had an overall average of 0.034 ml/min/g. The present study confirms quantitatively previous results suggesting a variable regional distribution of the monocarboxylic acid carrier.

Electronic Resource

1471-4159

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Abstract: Alterations in aspects of neurotransmission utilizing -γ-aminobutyric acid (GABA) are associated with in vivo exposure of rats to lead at doses that do not produce convulsions, but sensitize animals to convulsant agents. These effects are observed regionally and include: decreased GABA levels in cerebellum; increased activity of glutamate decarboxylase (GAD) in caudate; and decreased GABA release (both resting and K+-stimulated) in cortex, caudate, cerebellum and substantia nigra. Sodium-dependent uptake of GABA by synaptosomes of cerebellum, substantia nigra and caudate was also affected: in these regions, affinity (Km) was increased and maximal velocity (Vmax) was reduced. Sodium-independent binding of GABA to synaptic membranes was increased in cerebellum, but was observed only when tissue was Tritonized and prepared without freezing and washing. No effects on GAD or on GABA uptake, release, or binding were observed when lead was added to brain tissue in vitro in concentrations as high as 100 μM. The results suggest that lead may produce chronic inhibition of presynaptic GABAergic function, notably in the cerebellum, which is associated with supersensitivity of postsynaptic GABA receptors. Failure of lead to affect GABAergic function in vitro may indicate that these effects are secondary to another neurotoxic action of lead in the CNS or are consequent to a nonneuronal metabolic action of lead.

Electronic Resource

1471-4159

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Abstract— The level of saturation of glutamate decarboxylase (GAD) by cofactor, pyridoxal-5′-phosphate (pyridoxal-P), determined in synaptosomes prepared from substantia nigra tissue, was reduced from 45 to 28%; when ATP was included in the homogenizing medium to prevent nonspecific activation of GAD by endogenous pyridoxal-P. When the synaptosomes were incubated for 5–20 min at 37°C in Krebs-Ringer phosphate buffer (KRP), the level of saturation of GAD by cofactor decreased further, from 28 to 20%. Depolarization of the nigral synaptosomes by either high K+ (55 mM) or veratridine resulted in a significant increase in the level of GAD saturation by cofactor, to 32 and 41%. respectively. Omitting Ca2+ from the incubation medium blocked the depolarization-induced rise in the level of saturation. Depolarization with high K+ and veratridine also caused a significant decrease in the ATP concentration in the synaptosomes. No difference in ATP concentration was observed when the samples were incubated at 37°C for 5–20min or incubated in the absence of added Ca2+ with high K+. Results provide further evidence that in vivo brain GAD is largely unsaturated by cofactor and support the possibility that increased release and utilization of GABA may be associated with increases in the amount of pyridoxal-P endogenously bound to GAD in nerve terminals.

Electronic Resource

1471-0528

Blackwell Publishing Journal Backfiles 1879-2005

Medicine

Electronic Resource

1749-6632

Blackwell Publishing Journal Backfiles 1879-2005

Natural Sciences in General

Electronic Resource