Aryl Hydrocarbon Receptor Activation Enhances Total IgA Secretion in Leishmania Major-Infected Mice

Secretory IgA (antibody A) plays a critical role in neutralizing microbial toxins, regulating non-pathogenic gut microbe populations, and protecting against infections at mucous membranes, like the airways or gut. Altered IgA levels have been associated with increased risk of allergies, infection, and autoimmunity. The aryl hydrocarbon receptor (AhR) is a regulator of immune function, including IgA levels. Chemicals in food or the environment can affect IgA levels, and this has been proposed as a risk factor for human disease. In mice, activation of the AhR with a single dose of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), an environmental pollutant, has been shown to alter fecal IgA levels. The goal of this study was to investigate a mechanism to explain altered fecal IgA levels after TCDD exposure. Female C57Bl/6 mice were administered TCDD orally at 0 or 40 µg/Kg of body weight one day prior to subcutaneous infection with one million Leishmania major promastigotes. Three weeks later, antibody levels were measured in serum and fecal extract by ELISA. TCDD exposure did not significantly change total IgA, IgM, or IgG1 levels in serum nor did it significantly change L. major-specific IgA levels in serum or fecal extract. However, relative to control animals, TCDD exposure significantly increased total fecal IgA levels by 61% (P = 0.013). Conversely, the level of mRNA for IgA heavy chain (measured by RT-RT-PCR) was significantly reduced by 54% (P = 0.006). These results suggest that AhR activation enhances total IgA secretion in the gut but does not enhance antigen-specific IgA responses following pathogen challenge. One explanation for these results could be relocation of B cells from the spleen, bone marrow, and other tissues to the gut. These findings suggest a potential mechanism by which environmental chemical exposures can dysregulate immunity to the detriment of human health

Impact of tunnel barrier strength on magnetoresistance in carbon nanotubes

We investigate magnetoresistance in spin valves involving CoPd-contacted carbon nanotubes. Both temperature and bias voltage dependence clearly indicate tunneling magnetoresistance as the origin. We show that this effect is significantly affected by the tunnel barrier strength, which appears to be one reason for the variation between devices previously detected in similar structures. Modeling the data by means of the scattering matrix approach, we find a non-trivial dependence of the magnetoresistance on the barrier strength. Furthermore, analysis of the spin precession observed in a nonlocal Hanle measurement yields a spin lifetime of $\tau_s = 1.1\,$ns, a value comparable with those found in silicon- or graphene-based spin valve devices.Comment: 10 pages, 5 figures, 1 tabl

Das betriebliche Eingliederungsmanagement beim Ministerium für Arbeit, Soziales, Gesundheit und Familie in Potsdam

Die Diplomarbeit beinhaltet den Verfahrensablauf zum betrieblichen Eingliederungsmanagement. Wenn Arbeitnehmer länger als 6 erkrankt Wochen sind, solen diese wieder eingegliedert werden. Einzelne Gesichtspunkte werden in diesem Zusammenhang näher erläutert

Invitation to wading in water

Der Katalog ist anlässlich einer Ausstellung in der Universitätsbibliothek Bamberg 2011 erschienen und umfasst Abbildungen von 58 künstlerisch gestalteten Briefumschlägen, die Liesel Metten an Bernd Goldmann versandt hat. Er enthält außerdem einen Orginaltext "Briefe sehen - Bilder sehen" von Anne Duden. Liesel Metten lebt als Künstlerin in Nieder-Olm bei Mainz. Mit ihren witzigen, erfindungsreichen bildhauerischen Arbeiten, die von Tieren und Menschen in der Fabelwelt berichten, ist sie weit über ihren regionalen Wirkungskreis beachtet worden. Ihre Phantasie lässt sie dauernd Grenzen überschreiten, die sie beispielsweise zu einer fast literarischen Konzeptkunst führt. So hat sich Liesel Metten intensiv mit Bacharach und dessen Bedeutung in der Romantik auseinandergesetzt. Seit vielen Jahren erweiterte sie den Begriff Künstlerbrief, der in mehreren Ausstellungen präsentiert wurde, um die Gestaltung von Briefumschlägen. Sie transponiert ihre dreidimensionale Kunst in eine zweidimensionale und erweitert ihre Botschaft mittels Sondermarken der Post

Genetic relationship between predisposition for binge alcohol consumption and blunted sensitivity to adverse effects of alcohol in mice

BACKGROUND: Initial sensitivity to ethanol (EtOH) and the capacity to develop acute functional tolerance (AFT) to its adverse effects may influence the amount of alcohol consumed and may also predict future alcohol use patterns. The current study assessed sensitivity and AFT to the ataxic and hypnotic effects of EtOH in the first replicate of mice (HDID-1) selectively bred for high blood EtOH concentrations (BECs) following limited access to EtOH in the Drinking in the Dark (DID) paradigm. METHODS: Naïve male and female HDID-1 and HS/Npt mice from the progenitor stock were evaluated in 3 separate experiments. In Experiments 1 and 2, EtOH-induced ataxia was assessed using the static dowel task. In Experiment 3, EtOH-induced hypnosis was assessed by using modified restraint tubes to measure the loss of righting reflex (LORR). RESULTS: HDID-1 mice exhibited reduced initial sensitivity to both EtOH-induced ataxia (p < 0.001) and hypnosis (p < 0.05) relative to HS/Npt mice. AFT was calculated by subtracting the BEC at loss of function from the BEC at recovery (Experiments 1 and 3) or by subtracting BEC at an initial recovery from the BEC at a second recovery following an additional alcohol dose (Experiment 2). The dowel test yielded no line differences in AFT, but HS/Npt mice developed slightly greater AFT to EtOH-induced LORR than HDID-1 (p < 0.05). CONCLUSIONS: These results suggest that HDID-1 mice exhibit aspects of blunted ataxic and hypnotic sensitivity to EtOH which may influence their high EtOH intake via DID, but do not display widely different development of AFT. These findings differ from previous findings with the high alcohol-preferring (HAP) selected mouse lines, suggesting that genetic predisposition for binge, versus other forms of excessive alcohol consumption, is associated with unique responses to EtOH-induced motor incoordination

A New Approach to Learning How to Teach: medical students as instructional designers

As students at the David Geffen School of Medicine at UCLA, the student authors were given the opportunity to develop their own creative projects which would be used to teach future medical students. They chose their own topics, planned and researched their projects, and then implemented the projects in interactive digital Adobe Flash files. In the first project they created interactive case-based radiology teaching files. In the second project they integrated photographic images into the existing illustrative anatomy files. Students in subsequent years have learned from these files on computers both at home and in the school's anatomy lab. The experience of creating the files served as an opportunity for hands-on learning for the student authors, both of the material and of the practice of teaching. In this paper they describe why they undertook these projects, what exactly they did, and the impact their creation had on them. The projects demonstrate that student-driven educational materials are both possible and beneficial. Furthermore, their experience has allowed them to conclude that faculty at other medical schools should consider providing students with opportunities to develop their own creative projects that contribute to the curriculum

The Measurement of Language Lateralization with Functional Transcranial Doppler and Functional MRI: A Critical Evaluation

Cerebral language lateralization can be assessed in several ways. In healthy subjects, functional MRI (fMRI) during performance of a language task has evolved to be the most frequently applied method. Functional transcranial Doppler (fTCD) may provide a valid alternative, but has been used rarely. Both techniques have their own strengths and weaknesses and as a result may be applied in different fields of research. Until now, only one relatively small study (n = 13) investigated the correlation between lateralization indices (LIs) measured by fTCD and fMRI and showed a remarkably high correlation. To further evaluate the correlation between LIs measured with fTCD and fMRI, we compared LIs of 22 healthy subjects (12 left- and 10 right-handed) using the same word generation paradigm for the fTCD as for the fMRI experiment. LIs measured with fTCD were highly but imperfectly correlated with LIs measured with fMRI (Spearman's rho = 0.75, p < 0.001). The imperfectness of the correlation can partially be explained by methodological restrictions of fMRI as well as fTCD. Our results suggest that fTCD can be a valid alternative for fMRI to measure lateralization, particularly when costs or mobility are important factors in the study design