Extracorporeal albumin dialysis in a patient with primary sclerosing cholangitis: effect on pruritus and bile acid profile.
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Biomedical subjects
Publications and source records attributed to R E Stauber.
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Reduced hepatobiliary transporter expression could explain impaired hepatic uptake and excretion of bile salts and other biliary constituents resulting in cholestasis and jaundice. Because little is known about alterations of hepatobiliary transport systems in human cholestatic liver diseases, it was the aim of this study to investigate such potential changes. Hepatic mRNA levels in hepatobiliary transport systems for bile salts (NTCP, BSEP), organic anions (OATP2, MRP2, MRP3), organic cations (MDR1), phospholipids (MDR3), and aminophospholipids (FIC1) were determined in 37 human liver biopsies and control livers by competitive reverse-transcription polymerase chain reaction (RT-PCR). Transporter tissue distribution was investigated by immunofluorescence microscopy. In patients with inflammation-induced icteric cholestasis (mainly cholestatic alcoholic hepatitis), mRNA levels of NTCP, OATP2, and BSEP were reduced by 41% (P <.001), 49% (P <.005), and 34% (P <.05) compared with controls, respectively. In addition, NTCP and BSEP immunostaining was reduced. MRP2 mRNA levels remained unchanged, but canalicular immunolabeling for MRP2 was also decreased. mRNA expression of MRP3, MDR1, MDR3, and FIC1 remained unchanged. In contrast to the alterations of transporter expression in inflammation-induced icteric cholestasis, transporter expression did not change in anicteric cholestasis caused by primary biliary cirrhosis (PBC) stages I and II. In conclusion, reduced expression of hepatobiliary transport systems for bile salts and other organic anions may contribute to inflammation-induced cholestasis in humans. Reduction of transporter gene expression can occur at the mRNA level as observed for NTCP, OATP2, and BSEP. However, reduced MRP2 immunostaining in the presence of conserved MRP2 mRNA levels suggests an additional role for posttranscriptional/posttranslational mechanisms.
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In this study, we compared serum hepatitis C virus (HCV) RNA concentrations with HCV RNA concentrations in whole blood collection tubes, including two different types of EDTA tubes and nucleic acid stabilization tubes (NASTs). We also investigated the impact of a processing delay on HCV RNA concentration in these tubes. In NASTs, the mean HCV RNA concentration was comparable to the mean serum HCV RNA concentration at "date zero." In EDTA tubes, mean baseline HCV RNA concentrations were higher. Storage at room temperature up to 96 h did not result in a decline of HCV RNA concentration in any of the whole blood collection tubes. In NASTs, HCV RNA concentrations remained stable during the whole study period, whereas a significant increase of HCV RNA was observed in both types of EDTA tubes at 96 h compared to date zero. We concluded that HCV RNA remains stable in NASTs at room temperature for at least 96 h, allowing greater flexibility in sample collection and transport.
Impairments in muscle power production and recovery following short-duration intense activity could lead to decreased performance and risk of injury. We developed a power test for the knee extensor muscles using torque-velocity testing and moderate isotonic loads. Twenty-eight female volunteers performed three maximal efforts at each of four isotonic loads (27.1, 40.6, 54.2 and 67.8 N. m). If the calculated regression line for the torque-velocity data had an r2 >/= 0.95 (i.e. an acceptable test), maximal power (408 +/- 56 W) was computed from the data. Immediately after torque-velocity testing, the subjects repeated maximal effort knee extensions with 33.9 N. m for three bouts of 15 repetitions with 15 s of rest to produce muscle fatigue, defined as a decrease in power output during isotonic exercise. After a 4 min rest, the torque-velocity test was repeated and power calculated (345 +/- 48 W). For the group, the recovery of maximal power after the fatigue protocol was 85%. The extremes were represented by one subject who recovered only 70% of her maximal power and another who recovered completely (>98%). Physiological differences in muscle power following repeated exercise could have an impact on the outcome of therapeutic interventions for sports injuries, fatigue syndromes and occupational over-use conditions.
Portal venous decompression with transjugular intra-hepatic portosystemic shunt (TIPS) is a new approach in the treatment of Budd-Chiari syndrome. We report on a 31-year-old female with Budd-Chiari syndrome due to anti-phospholipid antibodies with compression of the inferior vena cava treated with TIPS and stenting of the inferior vena cava. TIPS was complicated by massive intra-hepatic haematoma which was managed conservatively. Treatment options and pathogenic mechanisms of Budd-Chiari syndrome under the rare coincidence of aplastic anaemia and anti-phospholipid syndrome are discussed. TIPS may be considered for venous decompression in Budd-Chiari syndrome, but physicians should be aware of potential TIPS' complications in these patients.
The level of hepatitis B virus (HBV) DNA in serum reflects the replicative activity of HBV. To compare serum HBV DNA levels in different states of hepatitis B, 47 sera of patients with HBeAg-positive chronic hepatitis B, 4 sera of patients with HBeAg-negative chronic hepatitis B, 40 samples of patients after HBeAg seroconversion during alpha interferon treatment, 57 sera of inactive HBsAg carriers, and 42 sera of patients who had recovered from chronic hepatitis B more than 12 months prior to blood collection were checked for the presence of HBV DNA with the Amplicor HBV Monitor Test. In patients with HBeAg-positive chronic hepatitis B, the median of serum HBV DNA levels (8.3 x 10(8) copies/ml) was significantly higher than that for patients after HBeAg seroconversion (6.2 x 10(3) copies/ml) and than that for inactive HBsAg carriers (5.6 x 10(3) copies/ml). None of the patients who had recovered from hepatitis B had detectable HBV DNA in serum. Quantitative PCR proved to be a valuable tool for identification of different states of HBV infection. This technique was found to be a good method for determination of serum HBV DNA levels both for patients with HBeAg seroconversion and for inactive carriers who showed low viremia not detectable by conventional hybridization assays.
The Cobas Amplicor HBV Monitor test for quantitative determination of hepatitis B virus (HBV) DNA in serum has recently been introduced. To evaluate the performance of this assay in a routine diagnostic laboratory, reproducibility of results was determined with the First European Union Concerted Action HBV Proficiency Panel and the Accurun 325 HBV DNA Positive Control, Series 300. Results for 270 routine serum samples were additionally evaluated. To avoid the retesting of a large number of samples due to titers exceeding the upper limit for the linear range of the assay, sera of patients with chronic hepatitis B (CHB) were diluted prior to the assay to 10(-4) in normal human plasma, which is included in the assay. The mean coefficient of variation was 22.9% for all input HBV DNAs. Of 270 routine serum samples, 182 (150 sera from transplant donors and 32 sera from patients who had recovered from CHB) tested negative. Eighty-six sera were found to be HBV DNA positive; in six sera, HBV DNA levels were found to exceed the upper limit for the linear range of the assay and had to be retested. In the remaining two sera, inhibition occurred. The semiautomated Cobas Amplicor HBV Monitor test showed sufficient reproducibility and helped in avoiding human error. The relatively narrow linear range of detection is a limitation of the new assay.
Hepatic uptake and excretion of bile salts and several nonbile salt organic anions (eg, bilirubin) are mediated by a distinct set of polarized transport systems at the basolateral and apical plasma membrane domains of hepatocytes and bile duct epithelial cells (cholangiocytes). With the increasing availability of molecular probes for these transporters, evidence now exists that decreased or even absent expression of hepatobiliary transport proteins in hepatocytes or cholangiocytes may explain impaired transport function that results in hyperbilirubinemia and cholestasis. This review summarizes the molecular defects in hepatocellular membrane transporters that are associated with hereditary and acquired forms of cholestatic liver disease.
Inflammatory cytokines produced in response to various infectious and non-infectious stimuli are potent inducers of intrahepatic cholestasis (inflammation-induced cholestasis). The cholestatic effect of cytokines results mainly from inhibition of expression and function of hepatocellular transport systems which normally mediate hepatic uptake and biliary excretion of bile salts and various non-bile salt organic anions (e.g. bilirubin). These cytokine effects are reversible and bile secretory function is restored upon disappearance of the inflammatory injury. This review summarizes the clinical, pathophysiological and molecular aspects of inflammation-induced cholestasis.
Hepatic uptake and biliary excretion of bile salts and non-bile salt organic anions (e.g., bilirubin) is mediated by specific transport proteins located at the basolateral and canalicular membranes of hepatocytes. Several hepatobiliary transport systems have been identified and cloned over the past years. This development has facilitated molecular biological and genetic analyses of these transporters in experimental cholestasis and human cholestatic liver diseases. Evidence now exists that decreased or even absent expression of hepatobiliary transport systems may explain impaired transport function resulting in hyperbilirubinemia and cholestasis. This review summarizes the molecular defects in hepatocellular membrane transporters associated with hereditary and acquired forms of cholestatic liver diseases. The increasing information on the molecular regulation of hepatobiliary transport systems should bring new insights into the pathophysiology and treatment of human cholestatic liver diseases.
We recently reported that vasopressin analogues correct the in vitro vascular hyporeactivity to adrenergic vasoconstrictors in portal hypertensive rats. The aim of the present study was to determine whether vasopressin reduces splanchnic blood flow in portal vein-ligated (PVL) rats by restoring vasoconstrictor responsiveness in vivo. The ultrasonic transit time-shift technique was used for blood flow measurements. At basal conditions, blood flow through the superior mesenteric artery was elevated 1.6-fold in PVL rats as compared with sham-operated (SHAM) control rats. PVL rats also exhibited blunted mesenteric constrictor responses to the adrenoceptor agonist, phenylephrine (0.03-1 micromol x min(-1) x kg(-1)). Terlipressin (2-20 microg x k(-1)) and arginine vasopressin (3-300 pmol x min(-1) x kg(-1)) dose-dependently reduced, and at the highest doses, even abolished, the difference in mesenteric blood flow (MBF) between PVL and SHAM rats. When expressed as percent changes relative to baseline, mesenteric arterial responses to terlipressin and arginine vasopressin were found to be enhanced in PVL rats as compared with SHAM rats. Moreover, pretreatment with terlipressin (20 microg x kg(-1)) reversed the mesenteric hyporesponsiveness to phenylephrine of PVL rats. These vasopressin effects were independent of the nitric oxide (NO) pathway, because they were not mimicked by inhibition of NO synthesis with N(G)-nitro-L-arginine methyl ester (L-NAME) (0.1-10 mg x kg(-1)). These data indicate that pharmacological doses of vasopressin reverse the splanchnic hyperemia by restoring the responsiveness to adrenergic vasoconstrictors in portal hypertensive rats.
The vasopressin receptor subtype involved in the enhancement by vasopressin of adrenoceptor-mediated vasoconstriction was investigated in rat isolated perfused mesenteric arteries. [Arg8]vasopressin (1-10 nM) dose-dependently increased the perfusion pressure and enhanced the pressor response to the adrenoceptor agonist methoxamine (40 nmol) or electrical stimulation of periarterial nerves (16 Hz), at the concentration of 10 nM of [Arg8]vasopressin up to 4 and 3 fold, respectively. During prolonged exposure (45 min) the direct vasoconstrictor effect of [Arg8]vasopressin (10 nM) rapidly declined whereas the potentiation of methoxamine-induced vasoconstriction was maintained. The selective vasopressin V1A receptor antagonist SR 49,059 (1-3 nM) and the non-selective V1A/B and oxytocin receptor antagonist [deamino-Pen1,Tyr(Me)2,Arg8]vasopressin (15-45 nM) inhibited the direct vasoconstrictor action of [Arg8]vasopressin but had no effect on the enhancement of the pressor response to methoxamine or electrical stimulation. The V1B receptor agonist [deamino-Cys1,beta-(3-pyridyl)-D-Ala2,Arg8]vasopressin (100-1000 nM) and the V2 receptor agonist [deamino-Cys1,D-Arg8]vasopressin (1-10 nM) were devoid of any pressor activity and did not potentiate methoxamine-evoked vasoconstriction. In contrast, [1-triglycyl,Lys8]vasopressin (100 - 1000 nM) potentiated the methoxamine responses without per se inducing vasoconstriction. In arteries precontracted with methoxamine (7.5 microM) pressor responses to [Arg8]vasopressin (3-10 nM) were not inhibited by a dose of SR 49,059 (3 nM) which abolished the peptide's vasoconstrictor effect under control conditions. These data show that the direct vasoconstrictor effect of [Arg8]vasopressin is mediated by V1A receptors while the enhancement of adrenoceptor-mediated pressor responses is insensitive to V1A, V1B, and oxytocin receptor antagonists and is not mimicked by selective agonists of V1B and V2 receptors. In conclusion, an unusual interaction of vasopressin with V1A receptors, or even the existence of a novel receptor subtype, has to be considered.
Primary biliary cirrhosis (PBC) is an autoimmune disease of the liver frequently associated with extrahepatic autoimmune phenomena. Specific antibodies against platelet glycoproteins may play an important role in the pathogenesis of thrombocytopenia associated with PBC. This is the first report of life-threatening idiopathic thrombocytopenic purpura successfully treated with steroids in a 62-yr-old woman 2 yr after liver transplantation for PBC.
1. Increased production of nitric oxide (NO) has been suggested to underlie both the vascular hyporeactivity to vasoconstrictors and the splanchnic vasodilatation seen in portal hypertension. This study assessed the role of NO in the vasoconstrictor hyporeactivity of portal vein-ligated (PVL) rats in isolated and in situ perfused mesenteric arterial beds. 2. Isolated perfused mesenteric arteries of PVL rats were significantly less reactive to noradrenaline (NA), methoxamine (METH), arginine vasopressin (AVP) and endothelin-1 (ET-1) than those from sham-operated (Sham) rats. 3. Blockade of NO synthesis with NG-nitro-L-arginine methyl ester (L-NAME, 100 microM) in isolated perfused mesenteric arteries from PVL rats restored the reactivity to bolus injections of AVP and ET-1, but had little effect on the hyporeactivity to NA or METH. Cyclo-oxygenase inhibition with indomethacin (5 microM) likewise did not restore reactivity to METH of isolated perfused mesenteric arteries of PVL rats. 4. The hyporeactivity to METH seen in isolated perfused mesenteric arteries from PVL rats was reduced by low concentrations of AVP (20 nM) or ET-1 (1 nM) which per se caused only a slight increase in perfusion pressure. When L-NAME (100 microM) was combined with AVP (20 nM) or ET-1 (1 nM), respectively, reactivity to METH of isolated perfused mesenteric arteries of PVL rats was restored to the level seen in Sham rats. These effects of AVP and ET-1 were not mimicked by precontracting the vessels with 5-hydroxytryptamine (5 microM). 5. The differential effects of L-NAME and AVP on the hyporesponsiveness to methoxamine and AVP were corroborated by experiments performed with the in situ perfused mesenteric vascular bed preparation. 6. These data indicate that both NO-dependent and NO-dependent mechanisms are involved in the vasoconstrictor hyporesponsiveness of mesenteric arteries from portal hypertensive rats. The hyporeactivity to AVP and ET-1 is mediated by NO whereas the reduced responsiveness to adrenoceptor agonists appears to be predominantly NO-independent AVP and ET-1, in addition, seem to inhibit the NO-independent mechanism of vascular hyporeactivity, since the hyporesponsiveness to METH was reduced in the presence of AVP or ET-1 and abolished by the combination of these peptides with L-NAME.
Budd-Chiari syndrome during pregnancy has rarely been reported. This report presents a case of acute hepatic failure in a 20-year-old pregnant woman attributable to Budd-Chiari syndrome with underlying resistance to activated protein C caused by factor V Leiden mutation. The patient delivered a healthy girl by cesarean section in the 31st week of pregnancy. Acute hepatic failure in the 6th week postpartum was successfully treated by emergency liver transplantation, and the patient and her child were doing well at 8-month follow-up. Liver transplantation was lifesaving; normal factor V production by the transplant corrected the underlying coagulopathy. In this patient, latent thrombophilia attributable to activated protein C resistance was apparently aggravated by the hypercoagulable state of pregnancy leading to acute Budd-Chiari syndrome. Activated protein C resistance should be sought as an etiologic factor in patients with Budd-Chiari syndrome.
BACKGROUND/AIMS: Isolated vessels of portal hypertensive rats exhibit decreased responsiveness to vasoconstrictors. The vasopressin analogue terlipressin is used in the treatment of portal hypertension since it is known to reduce portal pressure, an effect that is thought to arise from splanchnic vasoconstriction via stimulation of vasoconstrictor V1 receptors. This study assessed the effect of terlipressin on the in vitro vascular reactivity of portal hypertensive rats to the alpha-adrenoceptor agonist methoxamine. METHODS: Portal hypertension was produced by portal vein ligation. Sham-operated rats served as controls. In isolated perfused mesenteric arteries of portal vein ligated and sham-operated rats pressor responses to methoxamine (3 nmol-3 mumol) were determined in the absence and presence of the nitric oxide synthase inhibitor NG-nitro-L-arginine methyl ester (L-NAME; 100 microM), terlipressin or the selective V2 receptor agonist desmopressin (each 0.5 microM). In addition, the direct pressor properties of terlipressin (3 pmol-100 nmol) were compared to arginine vasopressin (3 pmol-1 nmol) in vessels of normal rats. RESULTS: Mesenteric vessels of portal vein ligated rats were markedly hyporeactive to methoxamine, even in the presence of L-NAME. Terlipressin alone reduced and in combination with L-NAME abolished the difference in reactivity to methoxamine between the portal vein ligated and sham-operated groups, while desmopressin was ineffective. Arginine vasopressin potently contracted vessels of normal rats with a threshold dose of 10 pmol and was maximally effective at 300 pmol. In contrast, terlipressin failed to produce pressor responses up to 100 nmol. CONCLUSIONS: Hyporeactivity of mesenteric vessels of portal vein ligated rats to methoxamine is predominantly independent of nitric oxide. Terlipressin alone ameliorates and in combination with L-NAME abolishes the hyporesponsiveness to methoxamine presumably by inhibiting the nitric oxide-independent mechanism that underlies the reduced responsiveness to methoxamine in portal hypertension. This effect of terlipressin appears to be independent of stimulation of V2 as well as vasoconstrictor V1 receptors.