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Variable Sensitivities (variable + sensitivity)
Selected AbstractsVariable sensitivity of plant communities in Iceland to experimental warmingGLOBAL CHANGE BIOLOGY, Issue 4 2005Ingibjörg S. Jónsdóttir Abstract Facing an increased threat of rapid climate change in cold-climate regions, it is important to understand the sensitivity of plant communities both in terms of degree and direction of community change. We studied responses to 3,5 years of moderate experimental warming by open-top chambers in two widespread but contrasting tundra communities in Iceland. In a species-poor and nutrient-deficient moss heath, dominated by Racomitrium lanuginosum, mean daily air temperatures at surface were 1,2°C higher in the warmed plots than the controls whereas soil temperatures tended to be lower in the warmed plots throughout the season. In a species-rich dwarf shrub heath on relatively rich soils at a cooler site, dominated by Betula nana and R. lanuginosum, temperature changes were in the same direction although more moderate. In the moss heath, there were no detectable community changes while significant changes were detected in the dwarf shrub heath: the abundance of deciduous and evergreen dwarf shrubs significantly increased (>50%), bryophytes decreased (18%) and canopy height increased (100%). Contrary to some other studies of tundra communities, we detected no changes in species richness or other diversity measures in either community and the abundance of lichens did not change. It is concluded that the sensitivity of Icelandic tundra communities to climate warming varies greatly depending on initial conditions in terms of species diversity, dominant species, soil and climatic conditions as well as land-use history. [source] Comparison of simple tests for the non-invasive diagnosis of clinically silent cirrhosis in chronic hepatitis CALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 5 2006G. BORRONI Summary Background Biopsy is the gold standard for assessing cirrhosis in patients with chronic hepatitis C virus infection, but it is expensive and at risk of complications. Alternative non-invasive methods have been developed but their usefulness remains uncertain. Aim To compare the accuracy of five non-invasive scores in detecting cirrhosis. Methods We reviewed the charts and liver biopsies of 228 consecutive, treatment-naïve, hepatitis C virus-positive patients, 13.2% of whom with histological diagnosis of cirrhosis. The five alternative scores were age-platelet index, cirrhosis discriminant score, aspartate transaminases to platelet ratio index, Pohl's index, and aspartate transaminases/alanine transaminases ratio. Results The specificities of the scores were good (87,100%), but not so their sensitivities (17,67%). Accordingly positive likelihood ratios were generally good but negative likelihood ratios were suboptimal. Combinations of the scores independently related to cirrhosis only slightly change this diagnostic accuracy. Using double cut-offs to exclude/diagnoses cirrhosis, cirrhosis discriminant score classified 21% of patients without misdiagnoses and aspartate transaminases to platelet ratio index classified 85% of case with 9% of misdiagnoses. Conclusions The five scores showed variable sensitivities and specificities in detecting liver cirrhosis, both individually and in combination. The use of double cut-off points may make the cirrhosis discriminant score and aspartate transaminases to platelet ratio index useful to reduce the number of patients submitted to liver biopsy. [source] Fifty years of antineutrophil cytoplasmic antibodies (ANCA) testing: do we need to revise the international consensus statement on testing and reporting on ANCA?APMIS, Issue 2009JAN WILLEM COHEN TERVAERT During the first international workshop on antineutrophil cytoplasmic antibodies (ANCA), Copenhagen 25 and 26 January 1988, ANCA, as detected by the indirect immunofluorescence (IIF) technique, was extensively discussed. Cytoplasmic fluorescence pattern was found in patients with vasculitis. In contrast, perinuclear fluorescence pattern was found in vasculitis but also in many other inflammatory disorders. At the workshop, it was stated that IIF should be combined with an antigen-specific technique and capture and direct enzyme-linked immunosorbent assay techniques were discussed. In 1999/2003, an international consensus statement on testing and reporting on ANCA was published. For vasculitis, IIF was advocated as a screening assay, followed by an antigen-specific assay. In other non-vasculitic inflammatory diseases, only IIF on ethanol-fixed granulocytes was advocated. Recently, it was demonstrated that antigen-specific tests could be used as screening tests. Furthermore, it became clear that antigen-specific tests, in which antigens are directly coated to the solid phase, demonstrate highly variable sensitivities and specificities, whereas when capture or anchor technologies are used, more reproducible results are obtained. Based on these studies, we propose that the international consensus statement on ANCA should be revised. [source] Cluster analysis of immunohistochemical markers in leiomyosarcoma delineates specific anatomic and gender subgroupsCANCER, Issue 18 2009Jason C. Carvalho MD Abstract BACKGROUND: Leiomyosarcoma (LMS) can be categorized into uterine, retroperitoneal, nonretroperitoneal soft tissue, cutaneous, visceral, and osseous anatomic subtypes. The differential expression of smooth muscle markers, estrogen receptor (ER), progesterone receptor (PR), and Wilms tumor-1 protein (WT1) by anatomic subtype and gender was explored. METHODS: A total of 78 LMS comprised of 30 uterine and 48 nonuterine tumors were studied. Nonuterine tumors were comprised of 17 soft tissue, 16 retroperitoneal, 7 cutaneous, 5 visceral, and 3 osseous subtypes. Immunohistochemical staining intensity on tissue microarray slides was scored as 0, 1+, or 2+, and cluster analysis was performed on the data. RESULTS: Smooth muscle actin was the most sensitive antibody (95%), followed by muscle-specific actin (91%), calponin (88%), desmin (73%), caldesmon (66%), and myosin (64%). Caldesmon and myosin were usually coexpressed, and were highest in retroperitoneal tumors (94%). There was no discernable correlation noted between histologic differentiation and smooth muscle marker expression. ER was much more common in women, with the highest frequencies noted in female retroperitoneal (86%) and uterine (63%) tumors. Nuclear WT1 was expressed in 11% of all tumors, and was limited to ER-positive uterine and female retroperitoneal tumors. Cluster analysis segregated 4 groups, most notably 1 driven by ER and PR, with the vast majority being uterine and female retroperitoneal tumors. CONCLUSIONS: Smooth muscle markers demonstrated variable sensitivities in LMS, with a tendency for anatomic subtypes to segregate based on expression patterns of these markers. ER defined a subgroup of uterine and female retroperitoneal tumors, and WT1 was limited to such tumors, suggesting a common line of differentiation as well as potential therapeutic targets. Cancer 2009. © 2009 American Cancer Society. [source] | ||||||||||