Transfer of the heritable nonhemolytic jaundice trait from the Gunn rat to the Sprague-Dawley rat

Congenital nonhemolytic jaundice as observed in the Gunn rat was transferred successfully to the Sprague-Dawley rat. This jaundice trait occurs as the result of a deficiency of bilirubin glucuronyltransferase and appeared to transfer by simple Mendelian inheritance. A comparison of jaundiced Gunn with jaundiced Gunn-Sprague-Dawley cross rats for plasma bilirubin level, bilirubin glucuronyltransferase activity and female reproductive performance showed no significant difference between the two jaundiced rat groups. The phenotypic expression of the jaundice trait as viewed by the parameters used in this study appeared to be the same for both the Gunn and Gunn-Sprague-Dawley cross rats. The transfer of the jaundice trait to another rat strain enhances the opportunity to characterize this animal model and to determine the possible influence of a long-term closed mating system.     

Excessive hepatic copper accumulation in jaundiced rats fed a high-copper diet

The response of copper metabolism to dietary copper challenge was investigated in jaundiced rats with elevated plasma concentrations of conjugated bilirubin as a result of impaired canicular transport of bilirubin glucuronides. Control and jaundiced rats were fed purified diets with either normal (64 μmol Cu/kg) or high (640 μmol Cu/kg) concentration of added copper. Copper loading produced a greater increase in hepatic copper concentrations in the jaundiced than in control rats. The greater dietary-copper-induced increase in hepatic copper in the jaundiced rats can be explained by the observed smaller rise in biliary copper excretion and a greater efficiency of dietary copper absorption. In individual rats, there was a positive relationship between hepatic copper concentrations and biliary copper concentrations. It is suggested that not the transport of copper from liver cells to bile but that from plasma to bile is diminished in the jaundiced rats. The elevated plasma copper concentrations in the jaundiced rats may support this suggestion.     

Staphylococcal bacteraemia,fusidic acid,and jaundice.

Fusidic acid was used to treat 131 out of 250 patients with staphylococcal bacteraemia over 10 years. Other antimicrobial agents were given to the 119 remaining patients. Thirty-seven patients were already jaundiced before antibiotic treatment was started. Jaundice developed during treatment in 38 out of 112 patients given fusidic acid (34%) and in two out of 101 patients given other antimicrobials. The incidence of jaundice was higher in patients given fusidic acid intravenously (48%) rather than by mouth (13%). Jaundice appeared within 48 hours after the administration of fusidic acid in 93% of these cases. When the drug was stopped serum bilirubin concentrations fell to normal values within four days in those patients in whom they had been previously normal and who survived the bacteraemic episode. Fusidic acid was associated with increasing jaundice in 13 of 19 patients (68%) already jaundiced before it was given. In six out of 32 patients who developed jaundice while receiving intravenous fusidic acid serum alkaline phosphatase activity was raised suggestive of cholestatic jaundice. The mechanism in the remaining patients was unknown. Fusidic acid, particularly the intravenous preparation, in invaluable in treating severe staphylococcal infection but should be used with caution in patients with abnormal liver function. Patients receiving intravenous fusidic acid should be given the oral form of the drug as soon as their clinical condition permits.     

New mutation causing jaundice in mice

A new mutant causing jaundice in mice is reported. Allelism tests indicate that it is not allelic with known hemolytic anemia mutants in mice [hemolytic anemia (sphha), jaundiced (ja), normoblastic anemia (nb), and spherocytosis (sph and sph2Be)]. The jaundiced condition appears in young mice at about 24 hours postpartum and is due to a major increase in unconjugated bilirubin in serum compared to normal controls. Adult mutant mice are not jaundiced and bilirubin levels do not differ from normal mice. Adult male mutants have reduced testes size and no viable sperm. Female mutants are fertile but overall maternal performance is reduced as indicated by increased mortality and reduced growth rate of pups. Genetic tests indicate that a single autosomal recessive gene is responsible for the condition. We propose that the mutant be designated hyper-unconjugated bilirubinemia, with the gene symbol hub.     

The congenic normal R/APfd and jaundiced R/APfd-j/j rat strains: a new animal model of hereditary non-haemolytic unconjugated hyperbilirubinaemia due to defective bilirubin conjugation

In this paper the production of the R/APfd-j/j strain which is congenic with the R/APfd strain is reported. The R/APfd-j/j completely lacks hepatic bilirubin UDP-glucuronyltransferase activity, as do our GUNNXR/Pfd-j/j rat strain and various other stocks of GUNN rats (j/j) described in the literature. Our recombinant inbred strain GUNNXR/Pfd-j/j was produced from non-inbred GUNN (j/j) rats. This GUNNXR/Pfd-j/j rat was used as a donor of the jaundice gene j, the R/APfd rat serving as the recipient. After eight backcross-intercross cycles (16 generations) the R/APfd-j/j strain was obtained which is congenic with the R/APfd strain. Congenicity was demonstrated by various techniques including transplantation of skin tissue, strain-specific tumour cells and hepatocytes, the mixed lymphocyte reaction, and comparison of biochemical markers. The potential of the novel inbred strain of jaundiced rat, R/APfd-j/j, and the corresponding control strain R/APfd for biochemical and clinical studies of bilirubin metabolism are briefly discussed.     

Use of Computer-assisted Model in Diagnosis of Drug Hypersensitivity Jaundice

Of 374 patients with jaundice seen in the liver unit over a four-year period 21 were finally thought to be hypersensitive to one of seven different drugs. The clinical, laboratory, and histological features were often difficult to distinguish from those of viral hepatitis, tumour of the extrahepatic biliary tree, or primary biliary cirrhosis. A computer-assisted diagnostic model made use of minor differences, and made a correct diagnosis in all patients. Even when information about drug ingestion was left out it was still correct in 81% of patients. Sixty-four other patients gave a history of ingestion of potentially hepatotoxic drugs of whom 62 were correctly diagnosed by the computer. In the complete series of 374 patients only two were incorrectly computed to have drug jaundice when there was no history of drug ingestion.Two additional patients became jaundiced after exposure to drugs, but were found to have primary biliary cirrhosis.     

Degradation of plasma bilirubin by a bilirubin oxidase derivative which has a relatively long half-life in the circulation

To enhance degradation of unconjugated bilirubin in hyperbilirubinemic subjects, we synthesized a bilirubin oxidase (EC 1.3.3.5) (BO) derivative (PEGBO) by covalently linking (2,4-bis[O-methoxy(polyethyleneglycol)]-6-chloro-s-triazine) (PEG) to the enzyme. Intravenously injected BO in rats disappeared from the circulation with a half-life of 2.5 min; the half-life of PEGBO was 190 min. Intravenously injected BO minimally and transiently decreased plasma bilirubin levels in jaundiced Gunn rats and in bile-duct-ligated jaundiced rats. In contrast, PEGBO rapidly and substantially decreased plasma bilirubin levels and the effect persisted for longer than 3 h. Renal dysfunction often occurs in patients with liver diseases. To study the role of bilirubin toxicity for the kidney, functions of transtubular transport for organic anions was measured in bile-duct-ligated jaundiced animals before and after treatment with PEGBO. Bile duct ligation decreased urinary excretion of phenolsulfophthalein (PSP), an organic anion used for renal function test. Treatment of the jaundiced animals with PEGBO increased the rate of PSP disappearance from the circulation and normalized its urinary excretion. Thus, PEGBO might be useful for the study of bilirubin toxicity in jaundiced animals.     

Circulating thyroid hormones in primates with mild or severe hepatitis following liver transplantation

In order to study the effects of acute immunologically mediated liver disease on circulating thyroid hormones, serum levels of thyroxine (T4, total and free) and triiodothyronine (T3) were measured in 8 baboons before and for 60 days after allogeneic liver transplantation. In 3 animals early rejection and jaundice developed; T4 levels declined as liver function deteriorated. In the 5 tolerant animals liver function was only temporarily deranged without jaundice and there was a consistent early rise in T4 (P less than 0.01) followed by a later fall. T3 concentrations were relatively normal in both groups. The T3 resin uptake test remained virtually unchanged in all animals. Serum T4 and T3 responses to exogenously administered bovine thyrotropin (TSH) were similar in the jaundiced and anicteric animals. We conclude that the early rise in T4 in the tolerant animals was caused by transient increases in thyroid binding globulin in (TBG) while the fall in thyroid hormones in these and in the jaundiced animals was related to a decline in TBG levels. Thyroid responsiveness to TSH is not disturbed by moderately deranged liver function.     

An immobilized enzyme reactor for the detoxification of bilirubin

An immobilized enzyme reactor has been developed for the degradation of bilirubin as a potential treatment for neonatal jaundice. It utilizes the enzyme bilirubin oxidase from Myrothecium verrucaria, which in the presence of molecular oxygen converts bilirubin to biliverdin and other products that are much less toxic than bilirubin. Bilirubin oxidase was covalently attached to agarose beads using cyano transfer activation. Forty percent of the specific activity of bilirubin oxidase was retained after immmobilization, and preparations with 20 units of enzymatic activity per gram of drained wet weight of gel were obtained. The stability of bilirubin oxidase at pH 7.4 and 37 degrees C was improved fivefold by immobilization. A 15-mL column containing immobilized bilirubin oxidase, through which a 37 degrees C solution of 332muM bilirubin and 450muM human serum albumin in 0.05M phosphate buffer (pH 7.4) was passed at 1 mL/min, converted more than 60 percent of the bilirubin per pass. The substrate specificity of the enzyme and the small volume of the reactor are important characteristics for this clinical application where it is desirable to remove only one compound from the blood and to minimize the volume of blood in the extracorporeal circuit. This reactor, by detoxifying the jaundiced infant's blood of bilirubin, would eliminate the risks associated with the use of donor blood as is done currently in treating severe neonatal jaundice.     

Renal bilirubin excretion in canine models of jaundice

Renal handling of bilirubin and its relationship to blood bilirubin level were investigated for up to 2 weeks in two models of jaundiced dogs, namely, chronic bile duct ligation (CBDL), which are mildly icteric, and choledococaval anastomosis (CDCA), which develop deep jaundice. The mean (+/- SD) urinary bilirubin excretion in CBDL plateaued at 30.3 +/- 9.3 mg/24 hr whereas in CDCA it continued to increase above the normal bilirubin production rate (56-84 mg/24 hr) up to 130-150 mg/24 hr. The renal clearance of bilirubin in both models was inversely proportional to serum bilirubin concentration. It was approximately twice as high in the CDCA model, which induced also a moderate diuresis. It is suggested that higher serum bilirubin levels in CDCA dogs is due to the increased production of bilirubin which is not compensated by the renal clearance of bilirubin.     

Clinical evidence of hepatoprotection induced by ursodeoxycholic acid.

Ursodeoxycholic-acid (UDCA) was introduced to the clinical practice as an effective agent for the dissolution of gallstones. The efficacy of UDCA was proved recently in the treatment of patients with chronic cholestatic liver disease. We demonstrate the hepatoprotective effect of UDCA in a patient with chronic cholestatic liver disease. A sixty-nine years old male patient was admitted to our department with severe jaundice. The laboratory and radiologic examinations revealed significant cholestasis without any morphological alterations. Among the serological tests the anti-HCV antibody was positive. Based on these findings and anamnestic data (no blood transfusion and/or operation), sporadic chronic C virus hepatitis was assumed with dominant cholestasis. The corticosteroid therapy even in high doses was ineffective, the liver function parameters worsened. Later UDCA (Ursofalk, Falk Pharma) was given at a dose of 250 mg three times daily. Clinical improvement was seen after the first week of UDCA treatment. The patient's complaints relieved parallel with decrease of serum bilirubin, gamma-glutamyl transferase and transaminase levels. These parameters showed further decrease during the treatment.     

Conceptual and ethical problems in the epistemology of genetic information

My thesis will be that the identification of genetic features and their medical interpretation follow at least partially from reductionist premises: “Genes are charging the gun, life(-style) will trigger it.” This simplistic metaphor illustrates a problem of genetic diagnosis: from the viewpoint of philosophy of science, concepts of the gene and the genome are vague and confused. Until now these concepts have not been defined satisfactorily. Partly on account of this there is an additional problem in applying genetic tests in medical diagnostics. The epistemic status of predictive genetic diagnosis in many cases can justifiably be called “opaque.” But a predictive genetic test is designed to reveal genetic knowledge of and for a client on the basis of scientific research. Methodologically the diagnosis of the scientific problem in genetics as a science is developed philosophically as an epistemological argument. The problem of genetics as applied science in medicine and society is the danger of irrationality due to reductionist premises of science. This problem is to be revealed by philosophical analysis. The major result of the argument is that the assessment of applications of basic research in genetics should include considerations from epistemology and philosophy of science. The epistemological status of scientific concepts and reasonableness of advice are interrelated. My thesis is that at the interface between theory of science in genetics and reasonableness of “genetic advice” is the responsibility of the researchers for concepts of their science.     

Two Cases of Thyroid Storm-Associated Cholestatic Jaundice

ObjectiveTo describe the association of the rare and serious complication of jaundice with severe thyrotoxicosis, a potentially lethal endocrine disorder.MethodsWe report the clinical, laboratory, and pathologic findings of 2 cases of severe jaundice (total bilirubin levels: 35.2 mg/dL in case 1 and 42 mg/dL in case 2) associated with thyroid storm in the absence of a history of liver disease, thionamide exposure, or congestive heart failure. We also present other relevant reports available in the literature.ResultsCase 1 was a 38-year-old woman who presented with nausea, vomiting, fatigue, pruritus, and frequent nonbloody diarrhea. She was transferred to our institution because of worsening hyperbilirubinemia. Case 2 was a 35-year-old woman admitted to a community hospital with thyroid storm and jaundice. Upon transfer to our institution, the patient was unconscious, mechanically ventilated, and in atrial fibrillation. In case 2, liver biopsy results revealed diffuse hepatocellular ballooning with intrahepatic cholestasis with mild portal lymphocytic infiltration. Both patients presented with severe cholestatic jaundice in the absence of congestive heart failure; underlying liver disease (infectious or autoimmune); or previous exposure to thionamides, other hepatotoxic agents, or complementary and alternative medications. In both cases, jaundice responded to therapy with antithyroid medications. Both patients eventually underwent thyroidectomy with complete resolution of the jaundice.ConclusionThe data strongly suggest that in these patients, the hepatic dysfunction was primarily due to hyperthyroidism. These cases indicate that the mere presence of hyperbilirubinemia during severe thyrotoxicosis should not per se delay the use of potentially life-saving thionamides once a thorough evaluation for other causes of liver disease has been completed. (Endocr Pract. 2007;13:476-480)     

Liver Dysfunction and Phosphatidylinositol-3-Kinase Signalling in Early Sepsis: Experimental Studies in Rodent Models of Peritonitis

Background

Hepatic dysfunction and jaundice are traditionally viewed as late features of sepsis and portend poor outcomes. We hypothesized that changes in liver function occur early in the onset of sepsis, yet pass undetected by standard laboratory tests.

Methods and Findings

In a long-term rat model of faecal peritonitis, biotransformation and hepatobiliary transport were impaired, depending on subsequent disease severity, as early as 6 h after peritoneal contamination. Phosphatidylinositol-3-kinase (PI3K) signalling was simultaneously induced at this time point. At 15 h there was hepatocellular accumulation of bilirubin, bile acids, and xenobiotics, with disturbed bile acid conjugation and drug metabolism. Cholestasis was preceded by disruption of the bile acid and organic anion transport machinery at the canalicular pole. Inhibitors of PI3K partially prevented cytokine-induced loss of villi in cultured HepG2 cells. Notably, mice lacking the PI3Kγ gene were protected against cholestasis and impaired bile acid conjugation. This was partially confirmed by an increase in plasma bile acids (e.g., chenodeoxycholic acid [CDCA] and taurodeoxycholic acid [TDCA]) observed in 48 patients on the day severe sepsis was diagnosed; unlike bilirubin (area under the receiver-operating curve: 0.59), these bile acids predicted 28-d mortality with high sensitivity and specificity (area under the receiver-operating curve: CDCA: 0.77; TDCA: 0.72; CDCA+TDCA: 0.87).

Conclusions

Liver dysfunction is an early and commonplace event in the rat model of sepsis studied here; PI3K signalling seems to play a crucial role. All aspects of hepatic biotransformation are affected, with severity relating to subsequent prognosis. Detected changes significantly precede conventional markers and are reflected by early alterations in plasma bile acids. These observations carry important implications for the diagnosis of liver dysfunction and pharmacotherapy in the critically ill. Further clinical work is necessary to extend these concepts into clinical practice. Please see later in the article for the Editors'' Summary     

Fatal hepatitis E viral infection in pregnant women in Ghana: a case series

ABSTRACT: BACKGROUND: Viral infections during pregnancy can pose serious threats to mother and fetus from the time of conception to the time of delivery. These lead to congenital defects, spontaneous abortion and even death. The definitive diagnosis and management of pregnancy-related viral infections may be challenging especially in less resourced countries. CASE PRESENTATION: We present clinical and laboratory responses to the diagnosis and management of three cases of fulminant hepatitis secondary to Hepatitis E viral infection in pregnancy.Case 1 was a 31-year-old Ghanaian woman who presented with a week's history of passing dark urine as well as yellowish discoloration of the eyes. She subsequently developed fulminant hepatitis secondary to Hepatitis E viral infection, spontaneously aborted at 24 weeks of gestation and later died.Case 2 was also a 31-year-old Ghanaian woman who was admitted with a four-day history of jaundice. She had low grade fever, but no history of abdominal pain, haematuria, pale stool or pruritus. She next developed fulminant hepatitis secondary to Hepatitis E viral infection. However, she did not miscarry but died at 28 weeks of gestation.Case 3 was a 17-year-old Ghanaian woman who was referred to the tertiary health facility on account of jaundice and anaemia. She had delivered a live male infant at maturity of 32 weeks but noticed she was jaundiced and had a presentation of active disease 3 days prior to delivery. The baby was icteric at birth and on evaluation, had elevated bilirubin (mixed type) with normal liver enzymes. Hepatitis E virus infection was confirmed in both mother and baby. However, the jaundice and the hepatomegaly resolved in mother and baby after 5 and 12 days respectively. CONCLUSION: To the best of our knowledge, these are the first documented cases of fatal fulminant hepatic failures resulting from HEV infection in Ghana.     

Binding of bilirubin with albumin-coupled liposomes: implications in the treatment of jaundice

In the present study, we demonstrated the suitability of liposomes as a method of removing plasma bilirubin in hyperbilirubinemic rats. The liposomes have innate tendency to bind with bilirubin through hydrophobic interaction. Among different types of liposomes, the positively charged liposomes were found to have maximum affinity to free bilirubin. However, the entrapment or coupling of serum albumin on the surface of egg phosphatidylcholine liposomes can render a several-fold increase in their bilirubin binding capacity. The proteoliposomes were able to preferentially bind with bilirubin even in the presence of erythrocytes. Interestingly, these liposomes were found to displace bilirubin bound on the surface of erythrocytes as well. The results of the present study further demonstrate that albumin-bearing liposomes were equally effective in removing plasma bilirubin in experimental jaundiced animals. These observations indicate that liposome-mediated selective homing of excess plasma bilirubin to the liver cells (cf. hepatocytes) may help in the development of safer strategy for the treatment of hyperbilirubinemic conditions in the model animals.     

Binding of bilirubin with albumin-coupled liposomes: implications in the treatment of jaundice

In the present study, we demonstrated the suitability of liposomes as a method of removing plasma bilirubin in hyperbilirubinemic rats. The liposomes have innate tendency to bind with bilirubin through hydrophobic interaction. Among different types of liposomes, the positively charged liposomes were found to have maximum affinity to free bilirubin. However, the entrapment or coupling of serum albumin on the surface of egg phosphatidylcholine liposomes can render a several-fold increase in their bilirubin binding capacity. The proteoliposomes were able to preferentially bind with bilirubin even in the presence of erythrocytes. Interestingly, these liposomes were found to displace bilirubin bound on the surface of erythrocytes as well. The results of the present study further demonstrate that albumin-bearing liposomes were equally effective in removing plasma bilirubin in experimental jaundiced animals. These observations indicate that liposome-mediated selective homing of excess plasma bilirubin to the liver cells (cf. hepatocytes) may help in the development of safer strategy for the treatment of hyperbilirubinemic conditions in the model animals.     

The calcium metabolism problem in space medical science

The currently frustrating problem of discrepancies between the non-significant calcium metabolic balance reports and the radiologic indications of bone loss in astronauts is discussed in reference to clinical data derived from human subjects with their musculoskeletal system immobilized by plaster casts.The pertinent literature is cited, the biochemical profile of environmentally induced osteoporosis is presented, the various concepts of calcium metabolism are reviewed, the clinical chemistry with radiologic findings on the Gemini astronauts are discussed, and the weightlessness syndrome is related to calcium utilization in the body.Hormones are assessed as relatively active in calcium absorption, in bone resorption, and in accelerating metabolic activity. Enzymes are portayed as behaving somewhat passive in calcium metabolism disorders.It is concluded that the results of research now in progress may clear up the problem of whether the densitometric results are in error or whether there occur intra-skeletal transfers of bone mineral not detected by balance investigations.     

Impaired fertility in the jaundiced female (Gunn) rat

The hyperbilirubinemic female Gunn rat has been reported to have impaired fertility. A total of 267 jaundiced (j/j) and 91 nonjaundiced (+/j) female Gunn rats were used in a series of experiments to characterize the nature of this reduced fertility. Sixteen percent of the jaundiced females mated and delivered litters which were characteristically small in number (4.5 pups). A comparison of the gross observations at necropsy of jaundiced and nonjaundiced pregnant rats indicated that the number of implantation sites and live fetuses were significantly lower in the jaundiced females. The number of fetal resorptions in these rats were significantly higher; whereas, the number of corpra lutea was similar for both genotypes. The significantly lower plasma bilirubin levels in the pregnant jaundiced rats compared to the nonpregnant suggested that the observed effect on fertility was related to the concentration of plasma bilirubin.     

Enzymic oxidation of unconjugated bilirubin by rat liver.

The presence of the enzyme bilirubin oxidase, which degrades bilirubin in vitro, was demonstrated in the liver. Subcellular-fractionation experiments indicate that bilirubin oxidase is located in both the inner and outer membranes of the mitochondria. The mean rate of the reaction is 1.57 +/- 0.38 (S.D.) nmol of bilirubin degraded/min per mg of mitochondrial protein (munits/mg of protein). With respect to the overall breakdown of bilirubin, the enzyme has a Km' of 136 microM-bilirubin and a Vmax.' of 9.13 munits/mg of protein. Its activity is influenced by the ionic strength of the media and is inhibited by KCN, thiol reagents, NADH and albumin. The enzyme is aerobic, and between 1 and 1.5 mol of O2 are consumed per mol of bilirubin degraded. The products of the reaction include propentdyopents. The hepatic bilirubin oxidase activity of the jaundiced Gunn-rat liver is not significantly different from that of the Sprague-Dawley rat, and it is not induced by beta-naphthoflavone.