Gender-specific modulation of cocaine-induced place preference by 3,4-methylenedioxymethamphetamine

Due to the character of the original source materials and the nature of batch digitization, quality control issues may be present in this document. Please report any quality issues you encounter to [email protected], referencing the URI of the item.Includes bibliographical references (leaves 28-32).In contemporary North-American culture, two frequently combined drugs possessing abuse liability are cocaine and "ecstasy" (+/- 3,4-methylenedioxy-methamphetamine [MDMA]). Each drug is a stimulant acting on brain dopamine sites, i.e., cocaine acts to block reuptake of dopamine while ecstasy increases voltage-gated release of the neurotransmitter. With recurrent use, disturbances in dopamine regulation may alter the reward properties of these drugs when presented singularly or concurrently. Because an increasing number of drug abusers are female (currently, females comprise nearly one-third of the drug-abusing population), possible differential drug sensitivity in females has emerged as an issue and could affect treatment programs. This is the first study to test for behavioral alterations across gender with concurrent administration of these frequently abused drugs. It was hypothesized that elevated levels of extracellular dopamine associated with a combined exposure regimen would increase CPP relative to the case where each drug was administered alone, and it was predicted this effect would be amplified in females relative to males. Adult male and female rats received one of three doses of cocaine (0 mg/kg, 2.5 mg/kg, 5 mg/kg) followed by MDMA (0 mg/kg, 5 mg/kg, 10 mg/kg) and were then tested in a CPP paradigm. Specifically, conditioned place preference (CPP), a commonly used model for studying the role of contextual cues in drug reward and drug-seeking, was employed in this investigation that sought to explore possible synergism between cocaine and MDMA (ecstasy) in male and female rats. These results, however, suggest a biphasic effect of MDMA reward and a linear correlation between cocaine dose and reward properties. Concurrent administration displays antagonism of each drug. Females displayed less overall sensitivity than males except at the highest level of MDMA. This suggests that chronic drug abuse potential may vary according to both drug dose and gender

The solid-state photo-CIDNP effect

The solid-state photo-CIDNP effect is the occurrence of a non-Boltzmann nuclear spin polarization in rigid samples upon illumination. For solid-state NMR, which can detect this enhanced nuclear polarization as a strong modification of signal intensity, the effect allows for new classes of experiments. Currently, the photo- and spin-chemical machinery of various RCs is studied by photo-CIDNP MAS NMR in detail. Until now, the effect has only been observed at high magnetic fields with 13C and 15N MAS NMR and in natural photosynthetic RC preparations in which blocking of the acceptor leads to cyclic electron transfer. In terms of irreversible thermodynamics, the high-order spin structure of the initial radical pair can be considered as a transient order phenomenon emerging under non-equilibrium conditions and as a first manifestation of order in the photosynthetic process. The solid-state photo-CIDNP effect appears to be an intrinsic property of natural RCs. The conditions of its occurrence seem to be conserved in evolution. The effect may be based on the same fundamental principles as the highly optimized electron transfer. Hence, the effect may allow for guiding artificial photosynthesis

Action Spectroscopy on Dense Samples of Photosynthetic Reaction Centers of Rhodobacter sphaeroides WT Based on Nanosecond Laser-Flash 13C Photo-CIDNP MAS NMR

Photochemically induced dynamic nuclear polarization magic-angle spinning nuclear magnetic resonance (photo-CIDNP MAS NMR) allows for the investigation of the electronic structure of the photochemical machinery of photosynthetic reaction centers (RCs) at atomic resolution. For such experiments, either continuous radiation from white xenon lamps or green laser pulses are applied to optically dense samples. In order to explore their optical properties, optically thick samples of isolated and quinone-removed RCs of the purple bacteria of Rhodobacter sphaeroides wild type are studied by nanosecond laser-flash 13C photo-CIDNP MAS NMR using excitation wavelengths between 720 and 940 nm. Action spectra of both the transient nuclear polarization as well as the nuclear hyperpolarization, remaining in the electronic ground state at the end of the photocycle, are obtained. It is shown that the signal intensity is limited by the amount of accessible RCs and that the different mechanisms of the photo-CIDNP production rely on the same photophysical origin, which is the photocycle induced by one single photon

Defensome against Toxic Diatom Aldehydes in the Sea Urchin Paracentrotus lividus

Many diatom species produce polyunsaturated aldehydes, such as decadienal, which compromise embryonic and larval development in benthic organisms. Here newly fertilized Paracentrotus lividus sea urchins were exposed to low concentration of decadienal and the expression levels of sixteen genes, implicated in a broad range of functional responses, were followed by Real Time qPCR in order to identify potential decadienal targets. We show that at low decadienal concentrations the sea urchin Paracentrotus lividus places in motion different classes of genes to defend itself against this toxic aldehyde, activating hsp60 and two proteases, hat and BP10, at the blastula stage and hsp56 and several other genes (14-3-3ε, p38 MAPK, MTase, and GS) at the prism stage. At this latter stage all genes involved in skeletogenesis (Nec, uni, SM50 and SM30) were also down-expressed, following developmental abnormalities that mainly affected skeleton morphogenesis. Moreover, sea urchin embryos treated with increasing concentrations of decadienal revealed a dose-dependent response of activated target genes. Finally, we suggest that this orchestrated defense system against decadienal represents part of the chemical defensome of P. lividus affording protection from environmental toxicants

Effektivität eines Evidence-based Nursing Trainings im stationären Akutsetting der Urologie

Die Zunahme pflegewissenschaftlicher Studiengänge ermöglicht es immer mehr Pflegenden, sich zu akademisieren und Kompetenzen im wissenschaftlichen Arbeiten zu erlernen. Trotz der Zunahme an Studienangeboten in den letzten Jahren in Deutschland, stellt akademisiertes Pflegepersonal, welches in der direkten Patientenversorgung tätig ist, weiterhin eine Seltenheit dar. Dabei ist längst bekannt, dass Pflege nicht nur ineffizient, sondern auch gefährlich sein kann, beruht sie nicht auf aktueller Evidenz. Der Begriff des Evidence-based Nursings (EBN) gewinnt an immer größerer Bedeutung und muss Einzug in die Pflegepraxis finden. Das Forschungsprojekt untersucht die Effektivität eines EBN-Trainings unter Pflegenden einer urologischen Akutstation und ermittelt, wie sich die Einstellung und das Wissen der Teilnehmenden gegenüber EBN durch die Teilnahme am Training verändern. Bei dem Design handelt es sich um einen Mixed-Method-Ansatz. Dazu wurde ein skalierter Fragebogen aus zwei validierten Instrumenten zusammengefügt, mündliche Befragungen durchgeführt und Gedächtnisprotokolle genutzt. Im Rahmen einer Prätest-Posttest-Befragung wurde der aktuelle Wissensstand der Pflegenden sowie ihre Haltung gegenüber der Nutzung aktueller Forschungsergebnisse in der Pflegepraxis ermittelt. Zwischen den beiden Erhebungsphasen fand ein EBN-Training statt, welches sich in drei Sitzungen gliederte. Bei den Ergebnissen zeigten sich sowohl vor als auch nach der Durchführung des Trainings eine hohe Bereitschaft und Offenheit der Pflegenden, neue Forschungserkenntnisse in der Praxis zu nutzen. Die tatsächliche Umsetzung von Forschungserkenntnissen in der Praxis veränderte sich durch das EBN-Training nicht. Eine deutliche Zunahme konnte dagegen im Austausch der Pflegenden untereinander und der selbstständigen Recherche nach Literatur beobachtet werden. Auch äußerten alle Teilnehmenden nach dem Training, den Begriff EBN zu kennen oder zu verstehen. Nach der Teilnahme am EBN-Training gaben jedoch mehr Pflegende als zuvor an, durch ihre beruflichen Aufgaben keine Zeit für das Lesen wissenschaftlicher Literatur zu haben und wenig Unterstützung durch ihre Vorgesetzten zu erhalten. Durch diese Arbeit konnte gezeigt werden, dass im Team eine große Bereitschaft herrscht, die Praxis weiterzuentwickeln und neue Erkenntnisse in die praktische Arbeit einfließen zu lassen. Jedoch liegen auch viele Faktoren vor, welche die Implementierung einer evidenzbasierten Praxis behindern wie mangelnde zeitliche Ressourcen, fehlende Unterstützungsangebote und unzureichendes Wissen. Nachdem die Pflegenden zum ersten Mal mit dem EBN-Prozess in Berührung gekommen sind, herrscht auch nach dem Projekt noch eine gewisse Unsicherheit. Weitere Workshops und regelmäßige Treffen werden zukünftig nötig sein, um EBN langfristig in den Pflegealltag zu integrieren.The increase in nursing science courses of study enables more and more nurses to become academics and to learn competences in scientific work. Despite the increase in study programmes in Germany in recent years, academically trained nursing staff working in direct patient care is still a rarity. It has long been known that nursing care can be not only inefficient but also dangerous if it is not based on current evidence. The concept of evidence-based nursing (EBN) is becoming increasingly important and must find its way into nursing practice. The research project investigates the effectiveness of EBN training among nurses in an acute urology ward and determines how participants' attitudes and knowledge about EBN change as a result of participating in the training. The design was a mixed-method approach. For this purpose a scaled questionnaire from two validated instruments was combined, oral interviews were conducted and memory protocols were used. A pretest-posttest survey was conducted to de termine the current knowledge of nurses and their attitudes towards the use of current research findings in nursing practice. Between the two survey phases, EBN training took place, which was divided into three sessions. The results show a high willingness and openness among nurses to use new research findings in practice. The actual implementation of research findings in practice did not change as a result of the EBN training. On the other hand a clear increase could be observed in the exchange among the nurses and the independent research for literature. Also, none of the participants said after the training that they did not know or understand the term EBN. After participating in the EBN training, however, more nurses than before stated that they had no time for reading scientific literature due to their professional tasks and that they received little support from their superiors. Although there is a great willingness in the team to further develop the practice and to incorporate new findings into the practical work, there are many factors that hinder the implementation of evidence-based practice. After the nurses have been exposed to the EBN process for the first time, there is still some uncertainty after the project. Further workshops and regular meetings will be necessary in the future to integrate EBN into everyday car

Do H+ ions obscure electrogenic Na+ and K+ binding in the E1 state of the Na,K-ATPase?

In contrast to other P-type ATPases, the Na,K-ATPase binding and release of ions on the cytoplasmic side, to the state called E1, is not electrogenic with the exception of the third Na+. Since the high-resolution structure of the closely related SR Ca-ATPase in state E1 revealed the ion-binding sites deep inside the transmembrane part of the protein, the missing electrogenicity in state E1 can be explained by an obscuring counter-movement of H+ ions. Evidence for such a mechanism is presented by analysis of pH effects of Na+ and K+ binding and by electrogenic H+ movements in the E1 conformation of the Na,K-ATPase

Electrogenic Partial Reactions of the Gastric H,K-ATPase

The fluorescent styryl dye RH421 was used to identify and investigate electrogenic reaction steps of the H,K-ATPase pump cycle. Equilibrium titration experiments were performed with membrane vesicles isolated from hog gastric mucosa, and cytoplasmic and luminal binding of K+ and H+ ions was studied. It was found that the binding and release steps of both ion species in both principal conformations of the ion pump, E1 and P-E2, are electrogenic, whereas the conformation transitions do not contribute significantly to a charge movement within the membrane dielectric. This behavior is in agreement with the transport mechanism found for the Na,K-ATPase and the sarcoplasmic reticulum Ca-ATPase. The data were analyzed on the basis of the Post-Albers reaction cycle. The equilibrium dissociation constants for K1 binding on the cytoplasmic side were 11 and 16 mM. The respective equilibrium dissociation constants on the luminal side were obtained via K+ concentration dependence of the enzyme activity and determined to be 0.11 mM for both luminal binding sites