Preparation and properties of specifically labeled radiochemically stable 3H-bilirubin.
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Animals↗
Biomedical subjects
J R Bloomer
Publications and source records attributed to J R Bloomer.
Studies of bilirubin kinetics in normal adults.
This report describes studies of bilirubin kinetics in 13 healthy young adults. The plasma content of unconjugated bilirubin-(14)C was determined at frequent intervals for 24-30 hr after the intravenous injection of a tracer dose of unconjugated isotopic bilirubin. Fecal and urinary radioactivity were measured for 7 days. During this time cumulative recovery averaged 96% of the injected dose. The plasma curves were processed by digital computer. For the 30 hr experimental period, a sum of three exponentials, with average half-times of 18, 81, and 578 min, was required to describe the data. Using the plasma curve integral method, the hepatic bilirubin clearance (47 +/-10 ml/min, mean +/-SD), the bilirubin production rate (3.8 +/-0.6 mg/kg per day), and the mean red blood cell life span (101 +/-13 days) were calculated directly from the parameters of this function. To gain further insight into the metabolism of unconjugated bilirubin, the data were also used to determine the parameters of a multicompartmental model. In the model proposed, plasma unconjugated bilirubin exchanges with two additional pools one of which is thought to represent extrahepatic extravascular, and the other intrahepatic unconjugated bilirubin. Bilirubin is eliminated from the system via the proposed intrahepatic pool. From the data and the model, pool sizes and exchange rates between compartments were calculated, and the liver: plasma concentration gradient estimated. These studies provide a detailed analysis of the kinetics of unconjugated bilirubin in a healthy normal population and are intended to serve as a reference point for studies of abnormal states.
Adult↗
Effect of hematin administration to patients with protoporphyria and liver disease.
Hepatic damage in protoporphyria appears to be caused by a toxic effect of excess protoporphyrin. Therapy which reduces the formation of excess protoporphyrin may, therefore, be helpful. We examined the effects of hematin administered i.v. to two patients with protoporphyria and decompensated cirrhosis. Neither patient had side effects from the compound or manifested signs of toxicity. The vascular disappearance of hematin in one patient was similar to that in patients with porphyria who do not have structural liver disease. In both patients, biochemical changes occurred that were compatible with a reduced rate of protoporphyrin formation. Thus, hematin administration may be useful in treating patients with protoporphyria who develop liver disease.
Adult↗
Orthotopic liver transplantation: a pathological study of 63 serial liver biopsies from 17 patients with special reference to the diagnostic features and natural history of rejection.
The histopathological features of orthotopic liver transplants were evaluated in 63 serial biopsy specimens from 17 patients. Biopsies were taken at the time of insertion of the liver (six biopsies), at the time of development of liver function abnormalities (11 biopsies) and as follow-up to previously abnormal biopsies (46 biopsies). The biopsies taken at the time of insertion all showed diffuse hepatocellular ballooning with confluent areas of necrosis in one case. Biopsies taken at the time of onset of rejection (nine cases) all showed a mixed portal inflammatory infiltrate, bile duct damage and central or portal vein endothelialitis (i.e., attachment of lymphocytes to the vein endothelium). Follow-up biopsies showed several patterns including: (i) resolution of changes of acute rejection with subsequent development of recurrent acute or chronic rejection (four cases); (ii) prolonged acute rejection simulating extrahepatic biliary obstruction (four cases); (iii) prolonged acute rejection with predominance of eosinophils simulating a drug reaction (one case); and (iv) rapidly progressive acute rejection leading to death (one case). Biopsy of the transplanted liver at the time of transplantation is useful to provide a baseline for comparison with later biopsies. Biopsy at the time of onset of changes in liver function is essential to confirm the presence of rejection prior to alteration of immunosuppression.
Adolescent↗
The liver in Crigler-Najjar syndrome, protoporphyria, and other metabolic disorders.
The liver may be involved in metabolic disorders in two ways. (i) Due to its critical role in several metabolic pathways, the liver may be the major site of expression of a biochemical abnormality. For example, in Type I Crigler-Najjar syndrome, absence of hepatic bilirubin glucuronyl transferase activity causes severe unconjugated hyperbilirubinemia which invariably leads to death from kernicterus. (ii) The liver may also be structurally damaged by the metabolic disorder. Several patients with protoporphyria have died in hepatic failure due to liver damage caused by protoporphyrin deposition. Numerous other metabolic disorders can be sited in which significant liver involvement occurs. In many of these disorders, there is no effective medical therapy.
Animals↗
Liver in disorders of porphyrin metabolism.
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Carcinoma, Hepatocellular↗
Review of support systems used in the management of fulminant hepatic failure.
Fulminant hepatic failure has an exceedingly high mortality. Liver transplantation is the treatment option of choice. Unfortunately, one-third of patients with fulminant hepatic failure die awaiting a donor liver. For over 35 years attempts to remove or dilute putative toxins in the blood have been unsuccessful in improving survival rates. The use of biocompatible interfaces with blood or plasma and current hepatocyte culture techniques have led to the development of new support systems. This generation of bioartificial livers will hopefully provide the necessary hepatic functions and prevent many of the complications associated with fulminant hepatic failure. This paper will review the support systems tried and currently under investigation, with an emphasis on bioartificial livers.
Cells, Cultured↗
Comparison of human and bovine protoporphyria.
Protoporphyria (PP) is an inherited disorder of porphyrin metabolism in man in which there is excessive accumulation and excretion of protoporphyrin. Recently, a similar disorder has been described in cattle. In this report, the clinical, biochemical, and genetic features of bovine and human PP are compared. Human and bovine PP are characterized by photosensitivity and elevation of erythrocyte and fecal protoporphyrin levels. In both disorders, a deficiency of heme synthase activity is present in all tissues which have been examined. The diseases differ clinically in that hepatobiliary disease has been found thus far only in human PP. They also have different inheritance patterns. Human PP is an autosomal dominant disease, while initial studies strongly suggest that there is an autosomal recessive pattern of inheritance in bovine PP.
Animals↗
Chronic hepatitis associated with drug abuse: significance of hepatitis B virus.
One hundred and seventy-seven former heroin addicts, consisting of 85 who were newly admitted to a methadone maintenance program and 92 who had received methadone for a mean period of 30 months, were prospectively studied for up to 2 years in order to determine: (1) the effect of heroin withdrawal on the hepatic abnormalities, and (2) the incidence of HBsAg, anti-HBs, and anti-HCc as indices of the frequency of hepatitis B virus infection. Our study indicates that (1) hepatic abnormalities persist when heroin is discontinued and are not temporally related to drug and/or needle usage, and (2) that 71% of subjects had either HBsAg or anti-HBs; anti-HBc was tested for in 16 patients and was present in 100%, although 9 of the 16 were both HBsAg- and anti-HBs-negative. This study suggests that hepatitis B is largely responsible for the liver dysfunction. It is proposed that an abnormality in immune function, induced by heroin, is responsible for the high incidence of chronic hepatitis. Attention is drawn to the similarity between former drug addicts and hemophiliacs, since both develop chronic hepatitis in spite of anti-HBs in the serum.
Adult↗
Pathogenesis and therapy of liver disease in protoporphyria.
Protoporphyria is an inherited disorder in man characterized by the overproduction of protoporphyrin, a compound that is excreted by the liver. Hepatobiliary disease may occur in protoporphyria, and several cases have been reported in which death was due to liver disease. Based on the histological evaluation of liver biopsy specimens from 18 patients, 6 of whom died with cirrhosis and liver failure, we speculate that liver disease in this condition is caused by protoporphyrin deposits in hepatobiliary structures. These deposits are composed of crystals and have a characteristic birefringence when examined by polarization microscopy.One patient with early liver damage was given cholestyramine and vitamin E in an attempt to reduce the amount of protoporphyrin which the liver excreted daily. Liver function tests returned to normal, and red cell and plasma protoporphyrin levels decreased. A repeat liver biopsy after one year of therapy showed healing, with decrease of the protoporphyrin deposits.Liver disease in protoporphyria may be treated by directing therapy toward the metabolic abnormality.
5-Aminolevulinate Synthetase↗
Itch in liver disease: facts and speculations.
Pruritus in hepatobiliary disease is commonly believed to be caused by retention of bile acids with their sequestration in the skin. HOwever, we have recently demonstrated that skin levels of bile acids in patients with cholestasis correlate poorly with pruritus. In this report, we present additional data concerning the relationship of pruritus to bile acid retention: (1) the urinary excretion of sulfated and nonsulfated bile acids was not significantly different in patients with cholestasis who itched compared to those who did not; (2) one patient with itch associated with a liver abscess had normal levels of bile acids in serum, skin, and urine; (3) patients with primary biliary cirrhosis who itched had lower serum bile acid levels than patients with mechanical biliary obstruction who did not itch.These studies support our premise that pruritus in hepatobiliary diseases is not directly related to bile acid retention. They suggest that the type of cholestatic disorder, and not simply the magnitude of the cholestasis, as estimated by the elevation of serum bile acids, is important. We propose that the agent responsible for pruritus is produced in response to cholestasis, possibly through activation of the alternate pathway of bile acid synthesis. Properties of the hypothetical pruritogen are discussed.
Adult↗
Hepatic protoporphyrin metabolism in patients with advanced protoporphyric liver disease.
Protoporphyria is a genetic disorder in which liver damage is caused by the toxic effect of protoporphyrin accumulation in the liver. In this study protoporphyrin was measured in the resected livers of 7 patients who had liver transplantation and an additional patient from whom liver tissue was obtained post mortem. Comparison of liver, erythrocyte and serum protoporphyrin levels demonstrated a marked gradient between these compartments: erythrocyte, 5781 +/- 655 micrograms/dl; serum, 384 +/- 102 micrograms/dl; liver 377,238 +/- 55,568 micrograms/100 gm wet weight, (mean +/- SE). Protoporphyrin levels in bile of 3 patients were 55,559, and 1,153 micrograms/dl, indicating a gradient between liver and bile as well. Examination of the livers by polarization microscopy and electron microscopy demonstrated protoporphyrin pigment crystals. In one patient who had recurrent liver disease after transplantation, the protoporphyrin concentration in the graft at the time of death was similar to that in the resected liver. These data indicate that liver protoporphyrin levels in patients with advanced protoporphyric liver disease are much higher than levels in blood and bile, in part because protoporphyrin forms crystalline deposits in liver tissue. Thus, progressive hepatic accumulation of protoporphyrin occurs in the face of impaired biliary excretion. An intrinsic defect in hepatic excretion of protoporphyrin is probably not necessary for this condition to develop because liver disease can occur in the graft following transplantation.
Adolescent↗