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JAMES KEATING CONNIE CHEUNG TIMOTHY J. PETERS ROBERT PRZEMIOSLO ROGER WILLIAMS ROY A. SHERWOOD 《Addiction biology》1998,3(2):205-211
Carbohydrate-deficient transferrin (CDT) was assayed in 105 patients with non-alcohol-related liver diseases, 50 patients with alcohol-induced liver disease and 40 alcohol misusers with minimal hepatic dysfunction. The patients with liver disease were hospitalized for assessment of suitability for orthotopic liver transplantation. CDT was measured by two commercially available micro anion exchange methods; CDTect (Pharmacia) and %CDT (AXIS). Additionally, total transferrin was measured to allow expression of the CDTect results as ‘relative’ measurements. Overall, 41/105 (39%) of patients with non-alcohol-related liver diseases had a raised CDTect result, 13/105 (12%) had a raised %CDT result and 26/105 (25%) an abnormal CDTect/total transferrin ratio. In general, patients with cholestatic liver disease, primary biliary cirrhosis or primary sclerosing cholangitis had more ‘false positive’ results by CDTect than did those with viral or autoimmune hepatitis. The sensitivity of the two methods for the detection of alcohol misuse was similar; CDTect 77%, %CDT 65% and CDTect/total transferrin ratio 70%. This was, however, lower than the sensitivity of the conventional marker GGT (82%). In patients with severe liver disease, where up to 30% of the serum total transferrin concentrations fall outside the reference range, ‘relative’ CDT methods have greater specificity than ‘absolute’ measurements. 相似文献
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LINDA C. IVANY STEPHEN C. PETERS BRUCE H. WILKINSON KYGER C. LOHMANN BETH A. REIMER 《Geobiology》2004,2(2):97-106
A sectioned and polished specimen of the coral Archohelia vicksburgensis from the early Oligocene Byram Formation (~30 Ma) near Vicksburg, Mississippi, reveals 12 prominent annual growth bands. Stable oxygen isotopic compositions of 77 growth‐band‐parallel microsamples of original aragonite exhibit well‐constrained fluctuations that range between ?2.0 and ?4.8. Variation in δ18O of coral carbonate reflects seasonal variation in temperature ranging from 12 to 24 °C about a mean of 18 °C. These values are consistent with those derived from a bivalve and a fish otolith from the same unit, each using independently derived palaeotemperature equations. Mg/Ca and Sr/Ca ratios were determined for 40 additional samples spanning five of the 12 annual bands. Palaeotemperatures calculated using elemental‐ratio thermometers calibrated on modern corals are consistently lower; mean temperature from Mg/Ca ratios are 12.5 ± 1 °C while those from Sr/Ca are 5.8 ± 2.2 °C. Assuming that δ18O‐derived temperatures are correct, relationships between temperature and elemental ratio for corals growing in today's ocean can be used to estimate Oligocene palaeoseawater Mg/Ca and Sr/Ca ratios. Calculations indicate that early Oligocene seawater Mg/Ca was ~81% (4.2 mol mol?1) and Sr/Ca ~109% (9.9 mmol mol?1) of modern values. Oligocene seawater with this degree of Mg depletion and Sr enrichment is in good agreement with that expected during the Palaeogene transition from ‘calcite’ to ‘aragonite’ seas. Lower Oligocene Mg/Ca probably reflects a decrease toward the present day in sea‐floor hydrothermal activity and concomitant decrease in scavenging of magnesium from seawater. Elevated Sr/Ca ratio may record lesser amounts of Oligocene aragonite precipitation and a correspondingly lower flux of strontium into the sedimentary carbonate reservoir than today. 相似文献
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