ABSTRACT
On the basis of previous ground-based and fly-by information, we knew that Titan's atmosphere was mainly nitrogen, with some methane, but its temperature and pressure profiles were poorly constrained because of uncertainties in the detailed composition. The extent of atmospheric electricity ('lightning') was also hitherto unknown. Here we report the temperature and density profiles, as determined by the Huygens Atmospheric Structure Instrument (HASI), from an altitude of 1,400 km down to the surface. In the upper part of the atmosphere, the temperature and density were both higher than expected. There is a lower ionospheric layer between 140 km and 40 km, with electrical conductivity peaking near 60 km. We may also have seen the signature of lightning. At the surface, the temperature was 93.65 +/- 0.25 K, and the pressure was 1,467 +/- 1 hPa.
ABSTRACT
Total serum bile acids measured by enzymatic fluorometry and routine liver function tests were determined in a large population including 97 healthy subjects, 138 patients free of hepatobiliary diseases but affected by other diseases, and 344 patients with mild or severe hepatobiliary diseases. In order to define the diagnostic value and some operational characteristics of serum bile acids, sensitivity, specificity, and several predictive value tables for increasing cutoff levels of serum bile acids were calculated by means of a computer program. Serum bile acids and aspartate aminotransferase were found to be similar in sensitivity, specificity, and predictive value. Serum aspartate aminotransferase was found to be more suitable than serum bile acids in detecting mild hepatobiliary diseases, whereas serum bile acids were more sensitive than routine liver tests in the evaluation of severe hepatobiliary diseases. In view of its ability to detect severe hepatobiliary diseases, serum bile acids test may play a decisive role in clinical practice (eg, decision to perform a liver biopsy).
Subject(s)
Bile Acids and Salts/blood , Biliary Tract Diseases/diagnosis , Liver Diseases/diagnosis , Liver Function Tests , Adolescent , Adult , Aspartate Aminotransferases/blood , Female , Humans , Male , Middle AgedABSTRACT
Sequential measurement of postprandial serum levels of bile acids was carried out in ten healthy controls and in four patients with different impairment of bile acids enterohepatic circulation. An enzymathic fluormetric method was used for SBA analysis. The peak of increase above fasting baseline in normal subjects was 11.8 +/- 1.2 microM/1 (mean +/- SD). In a cholecystectomized subject no SBA peak was observed. Two patients with mild and severe liver impairment (i.e. alcoholic steatosis and Summerskill-Walshe disease during an acute attack of jaundice) had postprandial SBA increase of 20 microM/1 and 70 microM/1 respectively. In a patient affected by Crohn's disease, with proved bile acids malabsorption, a negligible postprandial SBA increase was noted (6.65 microM/1). It is concluded that meal stimulated response of SBA levels might be useful index of altered hepatobiliary and intestinal function.
