We report a study of intergroup relations in a paper factory in which we examine the utility of three social‐psychological approaches: realistic conflict theory, the contact hypothesis and social identity theory. A sample of 177 shop floor workers from five different departments was interviewed. From them, measures of intergroup differentiation, perceived intergroup conflict, amount of intergroup contact, and strength of workgroup identification were obtained. The latter was assessed using a new scale of group identification developed for this study. Reliability and validity data for this scale are reported. Using multiple regression analyses we attempt to explain variance in respondents' intergroup differentiation using the other measures as predictor variables. The most powerful and reliable predictor was perceived conflict which, as expected, was positively correlated with differentiation. Less consistent was amount of contact which was negatively but only weakly associated with differentiation. Strength of group identification, while generally showing a positive correlation with differentiation as predicted, was also only a weak and inconsistent predictor variable. Noting that these results confirm findings from other studies we discuss their theoretical implications.
Using pH- and voltage-sensitive microelectrodes, as well as the two-electrode voltage-clamp and macropatch techniques, we compared the functional properties of the three NBCe1 variants (NBCe1-A, -B, and -C) with different amino and/or carboxy termini expressed in Xenopus laevis oocytes. Oocytes expressing rat brain NBCe1-B and exposed to a CO2/HCO3 − solution displayed all the hallmarks of an electrogenic Na+/HCO3 − cotransporter: (a) a DIDS-sensitive pHi recovery following the initial CO2-induced acidification, (b) an instantaneous hyperpolarization, and (c) an instantaneous Na+-dependent outward current under voltage-clamp conditions (−60 mV). All three variants had similar external HCO3 − dependencies (apparent KM of 4–6 mM) and external Na+ dependencies (apparent KM of 21–36 mM), as well as similar voltage dependencies. However, voltage-clamped oocytes (−60 mV) expressing NBCe1-A exhibited peak HCO3 −-stimulated NBC currents that were 4.3-fold larger than the currents seen in oocytes expressing the most dissimilar C variant. Larger NBCe1-A currents were also observed in current–voltage relationships. Plasma membrane expression levels as assessed by single oocyte chemiluminescence with hemagglutinin-tagged NBCs were similar for the three variants. In whole-cell experiments (Vm = −60 mV), removing the unique amino terminus of NBCe1-A reduced the mean HCO3 −-induced NBC current 55%, whereas removing the different amino terminus of NBCe1-C increased the mean NBC current 2.7-fold. A similar pattern was observed in macropatch experiments. Thus, the unique amino terminus of NBCe1-A stimulates transporter activity, whereas the different amino terminus of the B and C variants inhibits activity. One or more cytosolic factors may also contribute to NBCe1 activity based on discrepancies between macropatch and whole-cell currents. While the amino termini influence transporter function, the carboxy termini influence plasma membrane expression. Removing the entire cytosolic carboxy terminus of NBCe1-C, or the different carboxy terminus of the A/B variants, causes a loss of NBC activity due to low expression at the plasma membrane.
The hypothesis derived from Social Identity Theory that strength of group identification would be positively correlated with intergroup differentiation is tested. Data was obtained from 55 workers in a bakery using semistructured interviews. Analysis showed clear differentiation between the factory departments by subgroups of workers along dimensions of perceived contribution to the running of the factory and expressed friendliness towards out-groups. However, multiple regression analyses revealed that the relationship between group identification and intergroup differentiation was not consistently positive but varied between subgroup and between attitude dimensions. The most reliable predictor of differentiation, consistent with Realistic Conflict Theory, was perceived conflict between ingroup and outgroups.
Patients with osteoarthritis (OA), a condition characterized by cartilage degradation, are often treated with steroids, nonsteroidal anti-inflammatory drugs (NSAIDs), and cyclooxygenase-2 (COX-2) selective NSAIDs. Due to their inhibition of the inflammatory cascade, the drugs affect the balance of matrix metalloproteinases (MMPs) and inflammatory cytokines, resulting in preservation of extracellular matrix (ECM). To compare the effects of these treatments on chondrocyte metabolism, TNF-α was incubated with cultured chondrocytes to mimic a proinflammatory environment with increasing production of MMP-1 and prostaglandin E2 (PGE2). The chondrocytes were then treated with either a steroid (prednisone), a nonspecific COX inhibitor NSAID (piroxicam), or a COX-2 selective NSAID (celecoxib). Both prednisone and celecoxib decreased MMP-1 and PGE-2 production while the nonspecific piroxicam decreased only the latter. Both prednisone and celecoxib decreased gene expression of MMP-1 and increased expression of aggrecan. Increased gene expression of type II collagen was also noted with celecoxib. The nonspecific piroxicam did not show these effects. The efficacy of celecoxib in vivo was investigated using a posttraumatic OA (PTOA) mouse model. In vivo, celecoxib increases aggrecan synthesis and suppresses MMP-1. In conclusion, this study demonstrates that celecoxib and steroids exert similar effects on MMP-1 and PGE2 production in vitro and that celecoxib may demonstrate beneficial effects on anabolic metabolism in vivo.
The activity of HCO 3 − transporters contributes to the acid-base environment of the nervous system.In the present study, we used in situ hybridization, immunoblotting, immunohistochemistry, and immunogold electron microscopy to localize electrogenic Na/bicarbonate cotransporter NBCe1 splice variants (-A, -B, and -C) in rat brain. The in situ hybridization data are consistent with NBCe1-B and -C, but not -A, being the predominant NBCe1 variants in brain, particularly in the cerebellum, hippocampus, piriform cortex, and olfactory bulb. An antisense probe to the B and C variants strongly labeled granule neurons in the dentate gyrus of the hippocampus, and cells in the granule layer and Purkinje layer (e.g., Bergmann glia) of the cerebellum. Weaker labeling was observed in the pyramidal layer of the hippocampus and in astrocytes throughout the brain. Similar, but weaker labeling was obtained with an antisense probe to the A and B variants. In immunoblot studies, antibodies to the A and B variants (αA/B) and C variant (αC) labeled ~130-kDa proteins in various brain regions. From immunohistochemistry data, both αA/B and αC exhibited diffuse labeling throughout brain, but αA/B labeling was more intracellular and punctate. Based on co-localization Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. studies with antibodies to neuronal or astrocytic markers, αA/B labeled neurons in the pyramidal layer and dentate gyrus of the hippocampus, as well as cortex. αC labeled glia surrounding neurons (and possibly neurons) in the neuropil of the Purkinje cell layer of the cerebellum, the pyramidal cell layer and dentate gyrus of the hippocampus, and the cortex. According to electron microscopy data from the cerebellum, αA/B primarily labeled neurons intracellularly and αC labeled astrocytes at the plasma membrane. In summary, the B and C variants are the predominant NBCe1 variants in rat brain and exhibit different localization profiles. NIH Public Access
Congenital deficiency or acquired laxity of the suspensory ligaments of the spleen may result in extreme splenic mobility. This rare condition, which is termed wandering or ectopic spleen predisposes the elongated splenic pedicle to torsion. We present a case of splenic torsion with a new CT finding consisting of a whorled appearance of the splenic pedicle. To our knowledge this finding has not been described before.
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