Increased arterial compliance in decompensated cirrhosis.

BACKGROUND/AIMS: In patients with cirrhosis, the systemic circulation is hyperdynamic with low arterial blood pressure and reduced systemic vascular resistance. The present study was undertaken to estimate the compliance of the arterial tree in relation to severity of cirrhosis, circulating level of the vasodilator, calcitonin gene-related peptide (CGRP) and mean arterial blood pressure (MAP). METHODS: Arterial compliance (COMPart=deltaV/deltaP) was determined as the stroke volume relative to pulse pressure (i.e. systolic minus diastolic blood pressure) during a haemodynamic evaluation of portal hypertension in patients with biopsy-verified cirrhosis (Child-Turcotte classes A/B/C=10/15/6). RESULTS: COMPart was significantly higher in cirrhotic patients (n=31) than in controls (n=10) (1.44 vs 1.00 x 10(-3) l/mmHg, p<0.01). It increased significantly through the Child-Turcotte classes A, B, and C (1.02, 1.47, and 2.1 x 10(-3) l/mmHg, respectively, p=0.03). The stroke volume did not change significantly with the severity of the disease, but pulse pressure decreased through class A, B, and C (79, 65, and 50 mmHg, respectively, p<0.01). COMPart was slightly, but significantly correlated to the circulating level of CGRP (r=0.34, p<0.05), and a substantial but inverse correlation was present to MAP (r= -0.63, p<0.002). CONCLUSIONS: Elevated arterial compliance in cirrhosis is directly related to the severity of the disease and to the elevated level of circulating vasodilator peptide CGRP, and inversely related to the level of arterial blood pressure. The altered static and dynamic functions of the arterial wall in cirrhosis may have implications for the circulatory and homoeostatic derangement, and potentially for therapy with vasoactive drugs.     

Gamma‐variate plasma clearance versus urinary plasma clearance of 51Cr‐EDTA in patients with cirrhosis with and without fluid retention

In patients with fluid retention, the plasma clearance of ⁵¹Cr‐EDTA (Cl_exp obtained by multiexponential fit) may overestimate the glomerular filtration rate (GFR). The present study was undertaken to compare a gamma‐variate plasma clearance (Cl_gv) with the urinary plasma clearance of ⁵¹Cr‐EDTA (Cl_u) in patients with cirrhosis with and without fluid retention. A total of 81 patients with cirrhosis (22 without fluid retention, 59 with ascites) received a quantitative intravenous injection of ⁵¹Cr‐EDTA followed by plasma and quantitative urinary samples for 5 h. Cl_gv was determined from the injected dose relative to the plasma concentration‐time area, obtained by a gamma‐variate iterative fit. Cl_exp and Cl_u were determined by standard technique. In patients without fluid retention, Cl_gv, Cl_exp and Cl_u were closely similar. The difference between Cl_gv and Cl_u (Cl_gv – Cl_u = ΔCl) was mean ?0·6 ml min^?1 1·73 m^?2. In patients with ascites, ΔCl was significantly higher (11·8 ml min^?1 1·73 m^?2, P<0·0001), but this value was lower than Cl_exp – Cl_u (17·5 mL min^?1 1·73 m^?2, P<0·01). ΔCl increased with lower values of GFR (P<0·001). In conclusion, in patients with fluid retention and ascites Cl_gv and Cl_exp overestimates GFR substantially, but the overestimation is smaller with Cl_gv. Although Cl_u may underestimate GFR slightly, patients with ascites should collect urine quantitatively to obtain a reliable measurement of GFR.     

Hepatic venous oxygen content in alcoholic cirrhosis and non-cirrhotic alcoholic liver disease

Blood gas analyses and hepatic blood flow were determined during hepatic vein catheterization in order to establish a possible hypoxic component in alcoholic liver disease. Fifty-six patients (9 non-cirrhotic liver disease, 14 cirrhosis Child-Turcotte class A, 23 class B, 10 class C) and 10 control subjects were studied. Mean hepatic venous oxygen saturation and tension were almost the same in all groups, and hepatic blood flow was inversely correlated to the arteriohepatic venous oxygen difference (r = -0.53, P less than 0.01). Splanchnic oxygen uptake was similar in all groups studied. The arterio-hepatic venous difference of base excess was small and of the same size in all groups, indicating no enhanced production of lactic acid in the liver. Our results do not support the concept that hepatic venous oxygen content is low in alcoholic liver disease and thereby contributes to hypoxic liver damage.     

Effect of oral propranolol on circulating catecholamines in cirrhosis: relationship to severity of liver disease and splanchnic haemodynamics

Patients with cirrhosis, especially those with decompensated disease have enhanced sympathetic nervous activity. We have investigated the effect of a single oral dose of 80 mg propranolol on circulating catecholamines and related the effect to splanchnic and systemic haemodynamics in 22 patients with cirrhosis. Plasma noradrenaline (NA) was significantly above normal average (NA: 0.52 vs. 0.23 ng/ml, p less than 0.01) and increased with the severity of the liver disease (p less than 0.01). NA was negatively correlated with liver function as estimated by ICG clearance (r = -0.74, p less than 0.01). Azygos blood flow was increased (0.75 l/min) and positively related to plasma NA (r = 0.57, p = 0.05, n = 12). After propranolol intake, plasma NA increased from 0.52 to 0.59 ng/ml (p less than 0.01). This response was found in all Child-Turcotte classes (A: 0.37 to 0.43; B: 0.49 to 0.56; C: 0.78 to 0.88 ng/ml), and in patients with as well as without ascites. Plasma adrenaline increased in the same way (p less than 0.01). Hepatic blood flow (from 1.10 to 0.93 l/min, p less than 0.01) and azygos blood flow (from 0.75 to 0.55 l/min, n = 9, p less than 0.05) decreased significantly after oral propranolol. A borderline significant correlation was observed between the decrease in azygos blood flow and the increase in NA (r = 0.64, p = 0.06). Our results suggest that besides a relationship to liver function and severity of disease, sympathetic nervous activity, as reflected by circulating NA, will further enhance during beta-adrenergic blockade, probably by a compensatory mechanism.(ABSTRACT TRUNCATED AT 250 WORDS)     

Proliferation of human malignant hematopoietic cells in immunodeficient mice: suppression by antibody to pluripotent K-562 leukemia cells involves direct cytolysis and effector cells

Six human hematopoetic cell lines were successfully heterotransplanted into athymic (nude) and asplenic-athymic (lasat) neonatal mice. The tumors arising from leukemia and lymphoma cells could then be serially transplanted into adult nude mice. Seven days after the fourth serial mouse passage, each mouse was treated with goat immune gamma globulin against K-562 cells. One control group was treated similarly, but with nonimmune (normal) gamma globulin, while another control group was not treated. The goat gamma globulin was not toxic for nude and lasat mice, and the immune, but not the normal, gamma globulin suppressed local subcutaneous growth of myelosarcomas, lymphosarcomas, and Burkitt lymphoma cells. On the other hand, the growth of lung, breast, and prostatic carcinomas and a melanoma of human origin were not altered by the immune gamma globulin. Since suppression of cell growth occurred equally well in decomplemented mice, a complement-mediated cytotoxicity apparently cannot be considered as responsible for the abrogation. The Fab fragment of the immunoglobulin did not suppress the growth of the myelosarcomas. We conclude that antibody suppression of the in vivo proliferation was specific for malignant hematopoietic cells and that the Fc portion of IgG is necessary for in vivo cytolysis of leukemia cells. The most probable mechanisms are direct antibody cytolysis and antibody-dependent macrophage-mediated cytotoxicity.     

Hepatic-Intestinal Disposal of Endogenous Human Alpha Atrial Natriuretic Factor99-126 in Patients with Cirrhosis

Hepatic-intestinal disposal of endogenous human alpha atrial natriuretic factor99-126 (ANF) was assessed in 13 patients with cirrhosis (six Child-Turcotte class A, five class B, and two class C) and eight control subjects. The Fick principle was applied during hepatic vein catheterization. Arterial ANF concentration in patients with cirrhosis [11.1 +/- 1.6 (SEM) pmol/L] was not significantly different from that of the control subjects (14.9 +/- 4.2 pmol/L, NS). Arteriohepatic venous extraction ratio of ANF (0.43 +/- 0.05 in cirrhosis vs 0.37 +/- 0.09 in controls, NS), hepatic-intestinal clearance (274 +/- 46 vs 237 +/- 46 ml/min, NS) and removal rate (2.9 +/- 0.88 vs 3.1 +/- 0.77 pmol/min, NS) were closely similar in patients and controls. The present results give no indication that significantly reduced hepatic-intestinal disposal of ANF has a role in causing altered circulating plasma levels of this peptide in cirrhosis. This is in keeping with the presence of vascular clearance receptors and peptidases for ANF degradation independent of hepatocellular function.     

Pharmacokinetics of Cefuroxime in Porcine Cortical and Cancellous Bone Determined by Microdialysis

Traditionally, the pharmacokinetics of antimicrobials in bone have been investigated using bone biopsy specimens, but this approach suffers from considerable methodological limitations. Consequently, new methods are needed. The objectives of this study were to assess the feasibility of microdialysis (MD) for measuring cefuroxime in bone and to obtain pharmacokinetic profiles for the same drug in porcine cortical and cancellous bone. The measurements were conducted in bone wax sealed and unsealed drill holes in cortical bone and in drill holes in cancellous bone and in subcutaneous tissue. As a reference, the free and total plasma concentrations were also measured. The animals received a bolus of 1,500 mg cefuroxime over 30 min. No significant differences were found between the key pharmacokinetic parameters for sealed and unsealed drill holes in cortical bone. The mean ± standard error of the mean area under the concentration-time curve (AUC) values from 0 to 5 h were 6,013 ± 1,339, 3,222 ± 1086, 2,232 ± 635, and 952 ± 290 min · μg/ml for free plasma, subcutaneous tissue, cancellous bone, and cortical bone, respectively (P < 0.01, analysis of variance). The AUC for cortical bone was also significantly different from that for cancellous bone (P = 0.04). This heterogeneous tissue distribution was also reflected in other key pharmacokinetic parameters. This study validates MD as a suitable method for measuring cefuroxime in bone. Cefuroxime penetration was impaired for all tissues, and bone may not be considered one distinct compartment.