Sixth annual conference on alaskan placer mining

An abridged format of papers, presentations and addresses given during the 1984 conference held on March 28-29, 1984, compiled and edited by Daniel E. Walsh and M. Susan Wray

Gestation changes sodium pump isoform expression, leading to changes in ouabain sensitivity, contractility, and intracellular calcium in rat uterus.

Developmental and tissue-specific differences in isoforms allow Na+, K+-ATPase function to be tightly regulated, as they control sensitivity to ions and inhibitors. Uterine contraction relies on the activity of the Na+, K+ATPase, which creates ionic gradients that drive excitation-contraction coupling. It is unknown whether Na+, K+ATPase isoforms are regulated throughout pregnancy or whether they have a direct role in modulating uterine contractility. We hypothesized that gestation-dependent differential expression of isoforms would affect contractile responses to Na+, K+ATPase α subunit inhibition with ouabain. Our aims were therefore: (1) to determine the gestation-dependent expression of mRNA transcripts, protein abundance and tissue distribution of Na+, K+ATPase isoforms in myometrium; (2) to investigate the functional effects of differential isoform expression via ouabain sensitivity; and (3) if changes in contractile responses can be explained by changes in intracellular [Ca2+]. Changes in abundance and distribution of the Na+, K+ATPase α, β and FXYD1 and 2 isoforms, were studied in rat uterus from nonpregnant, and early, mid-, and term gestation. All α, β subunit isoforms (1,2,3) and FXYD1 were detected but FXYD2 was absent. The α1 and β1 isoforms were unchanged throughout pregnancy, whereas α2 and α3 significant decreased at term while β2 and FXYD1 significantly increased from mid-term onwards. These changes in expression correlated with increased functional sensitivity to ouabain, and parallel changes in intracellular Ca2+, measured with Indo-1. In conclusion, gestation induces specific regulatory changes in expression of Na+, K+ATPase isoforms in the uterus which influence contractility and may be related to the physiological requirements for successful pregnancy and delivery

Atherosclerosis affects calcium signalling in endothelial cells from apolipoprotein E knockout mice before plaque formation

AbstractLittle is known about how hypercholesterolaemia affects Ca2+ signalling in the vasculature of ApoE−/− mice, a model of atherosclerosis. Our objectives were therefore to determine (i) if hypercholesterolaemia alters Ca2+ signalling in aortic endothelial cells before overt atherosclerotic lesions occur, (ii) how Ca2+ signals are affected in older plaque-containing mice, and (iii) whether Ca2+ signalling changes were translated into contractility differences. Using confocal microscopy we found agonist-specific Ca2+ changes in endothelial cells. ATP responses were unchanged in ApoE−/− cells and methyl-β-cyclodextrin, which lowers cholesterol, was without effect. In contrast, Ca2+ signals to carbachol were significantly increased in ApoE−/− cells, an effect methyl-β-cyclodextrin reversed. Ca2+ signals were more oscillatory and store-operated Ca2+ entry decreased as mice aged and plaques formed. Despite clearly increased Ca2+ signals, aortic rings pre-contracted with phenylephrine had impaired relaxation to carbachol. This functional deficit increased with age, was not related to ROS generation, and could be partially rescued by methyl-β-cyclodextrin. In conclusion, carbachol-induced calcium signalling and handling are significantly altered in endothelial cells of ApoE−/− mice before plaque development. We speculate that reduction in store-operated Ca2+ entry may result in less efficient activation of eNOS and thus explain the reduced relaxatory response to CCh, despite the enhanced Ca2+ response

Atherosclerosis differentially affects calcium signalling in endothelial cells from aortic arch and thoracic aorta in Apolipoprotein E knockout mice

Apolipoprotein-E knockout (ApoE-/-) mice develop hypercholesterolemia and are a useful model of atherosclerosis. Hypercholesterolemia alters intracellular Ca2+ signalling in vascular endothelial cells but our understanding of these changes, especially in the early stages of the disease process, is limited. We therefore determined whether carbachol-mediated endothelial Ca2+ signals differ in plaque-prone aortic arch compared to plaque-resistant thoracic aorta, of wild-type and ApoE-/- mice, and how this is affected by age and the presence of hypercholesterolemia. The extent of plaque development was determined using en-face staining with Sudan IV. Tissues were obtained from wild-type and ApoE-/- mice at 10 weeks (pre-plaques) and 24 weeks (established plaques). We found that even before development of plaques, significantly increased Ca2+ responses were observed in arch endothelial cells. Even with aging and plaque formation, ApoE-/- thoracic responses were little changed, however a significantly enhanced Ca2+ response was observed in arch, both adjacent to and away from lesions. In wild-type mice of any age, 1-2% of cells had oscillatory Ca2+ responses. In young ApoE-/- and plaque-free regions of older ApoE-/-, this is unchanged. However a significant increase in oscillations (~13-15%) occurred in thoracic and arch cells adjacent to lesions in older mice. Our data suggest that Ca2+ signals in endothelial cells show specific changes both before and with plaque formation, that these changes are greatest in plaque-prone aortic arch cells, and that these changes will contribute to the reported deterioration of endothelium in atherosclerosis

Psychological and Emotional Responses to Climate Change among Young People Worldwide: Differences Associated with Gender, Age, and Country

Recent research has described concern and anxiety about climate change, especially among young people, but limited data are available looking at the responses of adolescents. Based on further analysis of an existing dataset that obtained survey responses from young people aged 16–25 in 10 different countries, this paper examines differences associated with gender and age, which are important predictors of vulnerability to the impacts of climate change. Gender differences were small but consistent, with female respondents expressing greater levels of concern and negative emotions, while male respondents were more optimistic and expressed greater faith in the government. Within this narrow age group, there were small but significant positive correlations showing that concern and negative emotions about climate change were higher among older respondents. There were complex differences among countries; in general, respondents in the Philippines, India, and Nigeria reported a stronger psychological impact of climate change than respondents in the United States and Finland. These results help to describe the extent and patterns of climate anxiety in multiple locations around the world in an age range that is relatively understudied

A Model for Collaborative Evaluation and Selection of Electronic Resources

A presentation at the Medical Library Association Annual Conference, Chicago, Illinois, May 17, 1999Purpose: This presentation will report on the establishment of an electronic resources committee including problems and issues requiring resolution, the steps to formation, configuration of personnel and the accomplishments of the committee since formation. An assessment of the strengths of the model will be discussed. Setting/Participants/Resources: Himmelfarb Health Sciences Library, The George Washington University Medical Center is a medium-sized academic health sciences library in an urban setting. Brief Description: Through a strategic planning initiative begun in September 1997, it was determined that the library needed to become more efficient in providing its patrons with access to electronic resources. The process for evaluation and selection of electronic resources needed revision. Lack of formal communication between collection development staff and other pertinent areas of the library and Medical Center, including systems and public services, hampered these efforts. In spring 1998, an electronic resources committee was formed to improve and direct the process of evaluation, selection, and implementation of electronic resources. Members of the committee include staff from technical services, systems, and reference. An Electronic Resources Coordinator position was developed to spearhead this activity. Since formation, the committee has developed a web links criteria policy, an electronic collection development policy, and a form to track electronic resources and licensing information. Electronic product selection moved from one or two individuals to a collaborative process. The committee has been allocated specific funds from the library collections budget to make purchases. The committee supports management in their negotiations with departments regarding selection and acquisition of electronic resources. Results/Outcome: Better, more informed selection decisions are being made: duplicative content and incompatible technologies are identified prior to expenditure of funds. This model (the committee) has yielded better exchange of information within the library and more effective responses to patron suggestions. The library has made strides toward greater integration of services and resources and increased access to health science information. The formation of the committee is a vital step toward this goal. Evaluation Method: Anecdotal patron comments regarding new resources and new availability of resources have been extremely favorable. A survey or needs assessment of library staff and patrons is planned