BDNF increases release probability and the size of a rapidly recycling vesicle pool within rat hippocampal excitatory synapses

Exerting its actions pre-, post- and peri-synaptically, brain-derived neurotrophic factor (BDNF) is one of the most potent modulators of hippocampal synaptic function. Here, we examined the effects of BDNF on a rapidly recycling pool (RRP) of vesicles within excitatory synapses. First, we estimated vesicular release in hippocampal cultures by performing FM4-64 imaging in terminals impinging on enhanced green fluorescent protein (eGFP)-labelled dendritic spines – a hallmark of excitatory synapses. Consistent with a modulation of the RRP, BDNF increased the evoked destaining rate of FM4-64 only during the initial phase of field stimulation. Multiphoton microscopy in acute hippocampal slices confirmed these observations by selectively imaging the RRP, which was loaded with FM1-43 by hyperosmotic shock. Slices exposed to BDNF showed an increase in the evoked and spontaneous rates of FM1-43 destaining from terminals in CA1 stratum radiatum, mostly representing excitatory terminals of Schaffer collaterals. Variance-mean analysis of evoked EPSCs in CA1 pyramidal neurons further confirmed that release probability is increased in BDNF-treated slices, without changes in the number of independent release sites or average postsynaptic quantal amplitude. Because BDNF was absent during dye loading, imaging, destaining and whole-cell recordings, these results demonstrate that BDNF induces a long-lasting enhancement in the probability of transmitter release at hippocampal excitatory synapses by modulating the RRP. Since the endogenous BDNF scavenger TrkB-IgG prevented the enhancement of FM1-43 destaining rate caused by induction of long-term potentiation in acute hippocampal slices, the modulation of a rapidly recycling vesicle pool may underlie the role of BDNF in hippocampal long-term synaptic plasticity.     

Variation of the immune response to sheep erythrocytes in several strains of mice and their crosses

Summary There is a continuous variation in the immune response to sheep erythrocytes in inbred and outbred strains of mice. In animals of equal age strain-specific differences are the most important cause of the variation. Female animals are on the average superior to the male ones. Especially in the 7 S response the crossbreds showed positive deviations from the mid-parent values, thus suggesting the existence of non-additive gene effects. In one crossing experiment maternal influences could be shown.

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Zusammenfassung Die Stärke der Immunantwort nach Injektion einer konstanten Dosis Schaferythrocyten variiert kontinuierlich in verschiedenen Mäusestämmen. Bei gleichaltrigen Tieren stellen stammbedingte Unterschiede eine wichtigere Varianzursache dar als das Geschlecht der Tiere. Trotzdem waren die weiblichen Tiere in der Mehrzahl der durchgeführten Tests den männlichen überlegen. Kreuzungstiere zeigten einen Hybrideffekt, der vor allem die Zahl der indirekten plaquebildenden Zellen in der Milz und den Titer der merkaptoäthanolresistenten Hämagglutinine im Serum betraf. In einem Kreuzungsexperiment konnte ein mütterlicher Effekt beobachtet werden.

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This investigation was supported by the Deutsche Forschungsgemeinschaft.     

The influence of carcinoma growth on diamine oxidase activity in human gastrointestinal tract

The distribution of diamine oxidase (DAO) activity was studied in patients having no carcinoma disease. Besides in gut DAO occurred in high activity only in kidney and mesenteric lymph nodes.In patients with adenocarcinoma of the large bowel or of the stomach the enzymic activity was reduced in the tumour tissue itself as compared with the adjacent mucosa in which part the highest activities were observed. In stomach it seemed most important that the enzymic activity was enhanced in the whole mucosa, also in a 10 cm distance from tumour where no histological alterations were found. This fact should be checked for significance in early tumour diagnosis.Supported by A. v. Humboldt Stiftung.Supported by a grant from Deutsche Forschungsgemeinschaft (Lo 199/7).     

Antibiotics from Algae XXXIII1: Phlorotannins of the Brown Alga Himanthalia elongata2,3

It is possible to obtain approximately 0.2% (relative to dry weight) phenols soluble in ethyl acetate from HIMANTHALIA ELONGATA. After removal of a fraction containing high-molecular weight substances, a total of 17 oligomeric phlorotannins with 2 to 8 aromatic rings can be isolated from the mixture of the acetylated phenol fraction. Apart from 2 derivatives belonging to the fucol group, diphlorethol and a tetraphlorethol not yet fully identified, all the other substances are fucophlorethols. Amongst these substances, a phenoxylated therphenyl derivative and several fucophlorethols with two-fold phenoxy-substituted biphenyl moieties were identified for the first time.     

Untersuchungen zum Synergismus von Ciprofloxacin mit β-Laktam-Antibiotika,Gentamicin, Minozyklin und Pipemidsäure

Zusammenfassung In der Studie wurde untersucht, inwieweit durch Zugabe von Ciprofloxacin die antibakterielle Wirkung der Pipemidsäure sowie von Minozyklin, Gentamicin, Cefazolin, Mezlocillin oder Ampicillin gegenüber resistenten bzw. mäßig empfindlichen Testkeimen der SpeziesEscherichia coli, Klebsiella pneumoniae/Klebsiella oxytoca, Pseudomonas aeruginosa undStaphylococcus aureus beeinflußt wird. Die Untersuchungen ergaben eine synergistische Wirkung mit Pipemidsäure bei allen geprüften Spezies. Die Kombination mit Gentamicin ließ beiE. coli undK. pneumoniae/K. oxytoca Synergismus, beiP. aeruginosa undS. aureus additive Wirkung erkennen. Auch Minozyklin hatte mit Ciprofloxacin eine synergistische Wirkung, jedoch nur beiS. aureus. Bei den anderen Spezies und Antibiotikakombinationen war weder ein Synergismus noch ein Antagonismus festzustellen.

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Studies on the synergism of ciprofloxacin with -lactam antibiotics, gentamicin, minocycline and pipemidic acid

Summary UsingEscherichia coli, Klebsiella pneumoniae/Klebsiella oxytoca, Pseudomonas aeruginosa andStaphylococcus aureus strains, we examined a possible influence of pipemidic acid, minocycline, gentamicin, cefazolin, mezlocillin and ampicillin on the antibiotic activity of ciprofloxacin. We found in all bacterial species synergistic influence by pipemidic acid. When ciprofloxacin was combined with gentamicin, synergism was observed inE. coli and inK. pneumoniae/oxytoca, additive effects inP. aeruginosa andS. aureus. In combination with minocycline we demonstrated synergism inS. aureus only. In all other bacterial species and antibiotic combinations we found neither synergism nor antagonism.

     

Wissenstranslation am Beispiel Bewegungsförderung von älteren Menschen: Wie gelangen wissenschaftliche Erkenntnisse in die kommunale Praxis?

Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz - Wissenschaftliche Ergebnisse können eine Wissensquelle für kommunale Akteurinnen und Akteure der...     

Aufbau von Interventionsdatenbanken für mehr Evidenzbasierung in Prävention und Gesundheitsförderung – methodische Überlegungen

Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz - Kommunale AkteurInnen erfahren bei der Entwicklung und Auswahl von Maßnahmen der Prävention und...     

Sexualisierte Gewalt in der Erfahrung Jugendlicher: Ergebnisse einer repräsentativen Befragung

Bundesgesundheitsblatt - Gesundheitsforschung - Gesundheitsschutz - Seit 1998 erhebt die Bundeszentrale für gesundheitliche Aufklärung (BZgA) im Rahmen ihrer Repräsentativbefragung...     

Meta-analysis of epigenome-wide association studies of carotid intima-media thickness

Common carotid intima-media thickness (cIMT) is an index of subclinical atherosclerosis that is associated with ischemic stroke and coronary artery disease (CAD). We undertook a cross-sectional epigenome-wide association study (EWAS) of measures of cIMT in 6400 individuals. Mendelian randomization analysis was applied to investigate the potential causal role of DNA methylation in the link between atherosclerotic cardiovascular risk factors and cIMT or clinical cardiovascular disease. The CpG site cg05575921 was associated with cIMT (beta?=??0.0264, p value?=?3.5?×?10^–8) in the discovery panel and was replicated in replication panel (beta?=??0.07, p value?=?0.005). This CpG is located at chr5:81649347 in the intron 3 of the aryl hydrocarbon receptor repressor gene (AHRR). Our results indicate that DNA methylation at cg05575921 might be in the pathway between smoking, cIMT and stroke. Moreover, in a region-based analysis, 34 differentially methylated regions (DMRs) were identified of which a DMR upstream of ALOX12 showed the strongest association with cIMT (p value?=?1.4?×?10^–13). In conclusion, our study suggests that DNA methylation may play a role in the link between cardiovascular risk factors, cIMT and clinical cardiovascular disease.