Low Urinary Free Cortisol as a Risk Factor for Patients with Variceal Bleeding

Background and Objectives: Specificity and reliability issues of the current cortisol assessment methods lead to limitations on the accurate assessment of relative adrenal insufficiency. Although free cortisol provides a more accurate evaluation of adrenal cortisol production, the expense and time-consuming nature of these assays make them impractical for routine use. Research has, thus, focused on alternative methods, such as indirectly measuring free cortisol using Coolens' equation or directly assessing salivary cortisol concentration, which is considered a more favorable approach despite associated challenges like sampling issues and infection risks. The aim of this study was to explore correlations between 24 h urinary free cortisol (UFC), free plasma cortisol, serum total cortisol, and salivary cortisol as potential reliable indices of free cortisol in the setting of variceal bleeding. Additionally, we assessed the predictive value of UFC for 6-week mortality and 5-day treatment failure in patients with liver cirrhosis and variceal bleeding. Materials and Methods: A total of 40 outpatients with liver cirrhosis and variceal bleeding were enrolled. Free cortisol levels in serum, saliva, and urine were assessed using the electrochemiluminescence immunoassay method. For the measurement of plasma-free cortisol, a single quadrupole mass spectrometer was employed. The quantification of free cortisol was fulfilled by analyzing the signal response in the negative ESI-MS mode. Results: UFC was significantly correlated to free plasma cortisol. Negative correlations were demonstrated between UFC, the Child-Pugh (CP) score, and C reactive protein (CRP) levels. In the multivariate analysis, CP stage C was associated with 6-week mortality risk and portal vein thrombosis with 5-day treatment failure using Cox regression and binary logistic regression analyses, respectively. Patients who experienced rebleeding, infection, or death (or any combination of these events) presented with lower levels of UFC. Conclusions: This study suggests that low levels of UFC may impose a risk factor for patients with liver cirrhosis and variceal bleeding. The use of UFC as an index of adrenal cortisol production in variceal bleeding warrants further investigation.

Protein measurement of particulate and solubilized ovine liver membranes

Protein concentration measurements are critical in biochemical work with cellular membranes, including the determination of cell surface receptor concentration in human malignant tissues obtained at surgery or after biopsy. In this study we compared the results of protein concentration measurements in ovine liver cellular membranes using either particulate preparations or membranes solubilized with four different detergents. In all cases protein was determined by two different indirect methods (Lowry's Folin phenol method and Bradford's Coomassie Brilliant Blue dye binding method) and compared to the direct biuret method. Our results indicate that the direct biuret method gives the highest protein concentrations followed by the method of Lowry. Maximal concentrations (approaching those obtained by the direct biuret method) were obtained after membrane solubilization with Triton X-100 (3-5%). It is suggested that either the direct biuret method (whenever protein concentrations permit it) or the method of Lowry after solubilization of membranes with Triton X-100 (3-5%) should be used preferentially for the determination of membrane protein samples.