Transient expression of Dp140, a product of the Duchenne muscular dystrophy locus, during kidney tubulogenesis

Dystroglycan is a cell surface complex which in muscle links the extracellular matrix protein laminin-2 to the membrane associated cytoskeletal protein dystrophin. Recently it was found that dystroglycan is also expressed in developing epithelial cells. Moreover, antibodies against dystroglycan can perturb epithelial cell development in kidney organ culture. Dystroglycan could provide a link between the basement membrane and the intracellular space also in epithelial cells. However, there is no dystrophin in epithelial cells. By in situ hybridization here we show prominent expression of a shorter isoform of dystrophin, Dp140, in embryonic kidney tubules. In addition, another isoform, Dp71, is expressed by all studied embryonic epithelial cells. Both isoforms share the dystroglycan-binding region of dystrophin but lack the region known to bind to actin. Here we also characterized monoclonal antibodies against different domains of dystrophin and used these to study the distribution of Dp140 protein. In embryonic kidney tubules the dystrophin antibody VIA4(2)A3 stained an intracellular antigen close to the basal cells. In contrast, no staining was observed in adult kidney. We suggest that Dp140 is a structural component during kidney tubulogenesis but it may also be involved in signal transduction.     

Hypofrontality revisited: a high resolution single photon emission computed tomography study in schizophrenia

Hypofrontality or reduced activity in the prefrontal cortex, measured as reduced frontal perfusion or glucose uptake, has gained the status of an established finding in the medical literature on schizophrenia. Many relevant studies, however, have potential sources of bias, such as small subject numbers, or unreliable performance of activation tasks by the patients during the scanning procedure. Seventy patients with non-affective and non-organic psychoses were recruited--most qualifying for DSM III-R schizophrenia or schizophreniform psychosis (n = 60)--together with 20 healthy volunteers. They underwent single photon emission computed tomography with 99mTc-exametazime, carried out at rest. Tracer uptake was normalised to the occipital cortex. Group differences in tracer uptake were predicted in anterior regions of interest (prefrontal cortex and mesial frontal/cingulate cortex). Actively psychotic (including schizophrenic) patients not taking any drugs showed increased uptake in the prefrontal cortex. Reduced tracer uptake occurred in the mesial frontal cortex of schizophrenic patients, particularly if they were taking drugs. Relatively increased prefrontal tracer uptake associated with relatively decreased mesial frontal uptake characterised the patients in comparison with the controls. Generalised hypofrontality is, therefore, not a feature of schizophrenic patients at rest whether taking drugs or not.     

Turn a Blind Eye If You Care: Impacts of Attitude Consistency,Importance, and Credibility on Seeking of Political Information and Implications for Attitudes

Abundant media outlets allow for much diversity of political messages and selective use among citizens. A 2‐session online field study examined impacts of attitude consistency, attitude importance, and source credibility on selective exposure to political messages and subsequent attitude accessibility. The first session assessed attitudes and their accessibility. In the second session, participants browsed online search results that featured attitude‐consistent and attitude‐discrepant messages associated with sources of either high or low credibility; selective reading was tracked. Then attitude accessibility was measured again. Participants spent less time with attitude‐discrepant messages compared to attitude‐consistent messages; this pattern was particularly pronounced among participants with higher attitude importance. Low importance fostered exposure to high‐credibility messages. Exposure to attitude‐discrepant, high‐credibility messages reduced attitude accessibility.