13C-breath tests in the study of microsomal liver function

Conventional liver tests can be used to estimate a mixture of injury and function but none of these may be regarded as a reliable marker either to quantify functional hepatic reserve or to reflect life-threatening complications of acute and chronic liver diseases. To overcome this limit, many dynamic tests have been developed in order to evaluate the "hepatic functional mass". Among these tests we can include breath tests with 13C-labeled substrates undergoing different metabolic pathways. As concerning the evaluation of microsomal function, two main categories of breath tests have been developed based on the limiting step in the different substrates metabolism. The first group include aminopyrine, caffeine and diazepam, all substrates with a metabolism independent from hepatic blood flow and dependent almost exclusively from the enzymatic activity of different cytochromes P450. The other group is composed of substrates with flow dependent metabolism like methacetin, phenacetin, erythromycin. The aim of this review is to describe the clinical applications of microsomal liver breath tests in different hepatic diseases

Levofloxacin-based triple therapy in first-line treatment for Helicobacter pylori eradication

BACKGROUND: The standard first-line therapies for Helicobacter pylori eradication are based on clarithromycin and amoxicillin or metronidazole. Recent studies suggested levofloxacin as an alternative option for both first-and second-line H. pylori eradication treatment. AIMS: To compare efficacy and tolerability of two different 7-day standard triple therapies versus 7-day levofloxacin-based triple therapy in first-line treatment for H. pylori infection. METHODS: Three hundred consecutive H. pylori positive patients were randomized to receive: clarithromycin, amoxicillin, esomeprazole (Group A: N = 100); clarithromycin, metronidazole, esomeprazole (Group B: N = 100); or clarithromycin, levofloxacin, esomeprazole (Group C: N = 100). H. pylori status was rechecked by (13)C urea breath test 6 wk after the end of therapy. RESULTS: Sixteen out of 300 patients discontinued treatment because of the occurrence of side effects (Group A, 5; Group B, 7; Group C, 4). The eradication rates in intention to treat (ITT) and per protocol (PP) analyses were: Group A, 75% and 79%; Group B, 72% and 77.4%; and Group C, 87% and 90.6%. The eradication rate achieved with levofloxacin-based triple therapy was significantly higher than that with standard therapies in either ITT (87%vs 75%, p <0.05; 87%vs 72%, p <0.01;) or PP analysis (90.6%vs 79%, p <0.05; 90.6 vs 77.4, p <0.05). No difference was found between standard triple therapies. The incidence of side effects was similar among groups. CONCLUSIONS: A 7-day levofloxacin-based triple therapy can achieve higher H. pylori eradication rates than standard regimens. These data suggest levofloxacin-based regimens can be the most effective in first-line anti-H. pylori therapy, at least in the Italian population

13C-breath tests in the study of microsomal liver function

Conventional liver tests can be used to estimate a mixture of injury and function but none of these may be regarded as a reliable marker either to quantify functional hepatic reserve or to reflect life-threatening complications of acute and chronic liver diseases. To overcome this limit, many dynamic tests have been developed in order to evaluate the "hepatic functional mass". Among these tests we can include breath tests with 13C-labeled substrates undergoing different metabolic pathways. As concerning the evaluation of microsomal function, two main categories of breath tests have been developed based on the limiting step in the different substrates metabolism. The first group include aminopyrine, caffeine and diazepam, all substrates with a metabolism independent from hepatic blood flow and dependent almost exclusively from the enzymatic activity of different cytochromes P450. The other group is composed of substrates with flow dependent metabolism like methacetin, phenacetin, erythromycin. The aim of this review is to describe the clinical applications of microsomal liver breath tests in different hepatic diseases

13C-breath tests in the study of microsomial liver function

Conventional liver tests can be used to estimate a mixture of injury and function but none of these may be regarded as a reliable marker either to quantify functional hepatic reserve or to reflect life-threatening complications of acute and chronic liver diseases. To overcome this limit, many dynamic tests have been developed in order to evaluate the "hepatic functional mass". Among these tests we can include breath tests with 13C-labeled substrates undergoing different metabolic pathways. As concerning the evaluation of microsomal function, two main categories of breath tests have been developed based on the limiting step in the different substrates metabolism. The first group include aminopyrine, caffeine and diazepam, all substrates with a metabolism independent from hepatic blood flow and dependent almost exclusively from the enzymatic activity of different cytochromes P450. The other group is composed of substrates with flow dependent metabolism like methacetin, phenacetin, erythromycin. The aim of this review is to describe the clinical applications of microsomal liver breath tests in different hepatic diseases