Poisoning by Amanita phalloides ("deathcap") mushrooms in the Australian Capital Territory

Amanita phalloides ("deathcap") mushrooms are widespread in south-eastern Australia. Seven patients presented to hospital in the Australian Capital Territory with poisoning by this mushroom between 1988 and 1998. Three developed hepatoxicity and one died. Because A. phalloides is becoming more widespread, increased community and medical awareness is needed to reduce the frequency and morbidity of poisoning.

Evidence of continuing bone recovery at a mean of 7 years after liver transplantation

Patients with end-stage liver disease have low bone-turnover osteoporosis, and there is often further bone loss of 20% to 30% after orthotopic liver transplantation (OLT). Bone recovery after OLT has been reported, but data are limited. We undertook studies to determine whether bone recovery continues in the long term. Twenty-eight adult patients alive at least 5 years after OLT were studied (14 men, 14 women). Bone mineral density (BMD), serum parathyroid hormone (PTH), osteocalcin, and vitamin D levels were measured pretransplantation, at 3 months, 12 months, a mean of 46 months, and a mean of 85 months (range, 63 to 117 months) after transplantation. When BMD is expressed as a z score, the results were as follows: x0.82 +/- 0.22 pre-OLT; -2.04 +/- 0.27 at 3 months; -1.68 +/- 0.24 at 12 months; -1.23 +/- 0.24 at a mean of 46 months; and -1.0 +/- 0.26 at a mean of 85 months after OLT. The results at 46 and 85 months were significantly greater than the measurement at 3 months after OLT (P <.05). Furthermore, mean BMD (expressed as a z score) returns to the pre-OLT level at a mean of 85 months. At final follow-up, 9 of 28 patients had elevated PTH levels, and 14 of 27 patients had elevated osteocalcin levels. Five patients had spontaneous fractures in the first 12 months after transplantation, and 5 more patients had fractures by final follow-up. Even at 7 years after OLT, there was a significant increase in BMD (expressed as a z score) compared with 3 months after transplantation. Elevation of serum PTH and osteocalcin levels in some patients suggests continuing bone remodeling.

Effects of liver disease and transplantation on the human prostate

A major determinant of late-life prostate diseases is hormonal exposure during earlier life, but the effects of androgens in midlife on the human prostate have been little studied. In order to identify hormonal effects on the prostate during the long latent period of midlife, we studied the effects of chronic androgen deficiency on the prostate during midlife by examining men with severe liver disease before and after liver transplantation. Patients (n = 15, median 57, range 38-65 years old) with severe liver disease but no known prostate disease being evaluated for liver transplantation underwent 21 prostate ultrasound studies, 12 prior to and 9 after liver transplantation, with six men undergoing both studies. Controls were 42 prostate ultrasound studies (2:1 matching) from age-matched healthy men. Total- and central-prostate volumes were measured with a 7.5-MHz biplane transducer planimetrically at 2.5-mm intervals with a stepper device from base to apex of the prostate. Overall, total- and central-prostate volumes were not significantly different between patients with chronic liver disease before and after liver transplantation and age-matched healthy controls. This appeared to be due to a bimodal distribution, with most men (12 men, 17 studies) having smaller prostate volumes and a minority (3 men, 4 studies) having previously undiagnosed, macroscopic, benign prostatic hyperplasia. The reduction in prostate volume prior to transplantation was significantly correlated with severity of liver disease (Child-Pugh score). Before liver transplantation, prostate-specific antigen (PSA) concentrations were significantly lower and prostatic acid phosphatase increased, and both were normalized after liver transplantation. Plasma testosterone concentrations were decreased before transplantation and remained low after transplantation. Sex hormone-binding globulin level was significantly elevated before and reduced to subnormal after liver transplantation. Estradiol concentrations were unchanged by liver disease or transplantation. We conclude that prostate volumes, particularly that of the central zone, are usually reduced by the functional androgen deficiency of chronic liver disease and tend to be restored toward normal by liver transplantation, depending on the degree of rectification of circulating plasma testosterone concentrations. Prostate glands with established benign prostatic hyperplasia may be less responsive to these hormonal changes.

Fibroblast activation protein: a cell surface dipeptidyl peptidase and gelatinase expressed by stellate cells at the tissue remodelling interface in human cirrhosis

Fibroblast activation protein (FAP) is a cell surface-bound protease of the prolyl oligopeptidase gene family expressed at sites of tissue remodelling. This study aimed to delineate the expression of FAP in cirrhotic human liver and examine its biochemical activities. Seventeen cirrhotic and 8 normal liver samples were examined by immunohistochemistry and reverse-transcriptase polymerase chain reaction (RT-PCR). Hepatic stellate cells (HSC) were isolated and immunostained. Recombinant FAP and immunopurified, natural FAP were analyzed for protease activities and similarities to dipeptidyl peptidase IV (DPPIV), a structurally related enzyme. FAP-specific messenger RNA and immunoreactivity were detected in cirrhotic, but not normal, livers. FAP immunoreactivity was most intense on perisinusoidal cells of the periseptal regions within regenerative nodules (15 of 15 cases); this pattern coincides with the tissue remodelling interface. In addition, human FAP was expressed by cells within the fibrous septa (10 of 15 cases). Cell morphology, location, and colocalization with glial fibrillary acidic protein (GFAP) indicated that FAP is present on HSC in vivo. Similarly, isolated HSC expressed FAP in vitro. Both natural FAP from cirrhotic liver and recombinant FAP were shown to have gelatinase and dipeptidyl peptidase activities. FAP is a cell-bound, dual-specificity dipeptidyl peptidase and gelatinase expressed by activated HSC at the tissue remodelling interface in human cirrhosis. FAP may contribute to the HSC-induced extracellular matrix (ECM) changes of cirrhosis.

Pancreatic stellate cells are activated by proinflammatory cytokines: implications for pancreatic fibrogenesis

BACKGROUND

The pathogenesis of pancreatic fibrosis is unknown. In the liver, stellate cells play a major role in fibrogenesis by synthesising increased amounts of collagen and other extracellular matrix (ECM) proteins when activated by profibrogenic mediators such as cytokines and oxidant stress.

AIMS

To determine whether cultured rat pancreatic stellate cells produce collagen and other ECM proteins, and exhibit signs of activation when exposed to the cytokines platelet derived growth factor (PDGF) or transforming growth factor beta (TGF-beta).

METHODS

Cultured pancreatic stellate cells were immunostained for the ECM proteins procollagen III, collagen I, laminin, and fibronectin using specific polyclonal antibodies. For cytokine studies, triplicate wells of cells were incubated with increasing concentrations of PDGF or TGF-beta.

RESULTS

Cultured pancreatic stellate cells stained strongly positive for all ECM proteins tested. Incubation of cells with 1, 5, and 10 ng/ml PDGF led to a significant dose related increase in cell counts as well as in the incorporation of 3H-thymidine into DNA. Stellate cells exposed to 0.25, 0.5, and 1 ng/ml TGF-beta showed a dose dependent increase in alpha smooth muscle actin expression and increased collagen synthesis. In addition, TGF-beta increased the expression of PDGF receptors on stellate cells.

CONCLUSIONS

Pancreatic stellate cells produce collagen and other extracellular matrix proteins, and respond to the cytokines PDGF and TGF-beta by increased proliferation and increased collagen synthesis. These results suggest an important role for stellate cells in pancreatic fibrogenesis.

Vascular endothelial growth factor expression in human chronic renal allograft rejection

BACKGROUND

Chronic renal allograft rejection is characterized by interstitial fibrosis and vasculopathy. Vascular endothelial growth factor (VEGF) is an endothelial mitogen with increased expression in inflammation and vasculopathy.

METHODS

Renal tissue from 17 patients with chronic rejection was examined for VEGF protein and the presence of CD 68-positive macrophages, and compared to biopsies from patients with temporary allograft dysfunction, acute rejection, and native kidneys with thin membrane disease.

RESULTS

In the chronic rejection group, there was markedly increased expression of VEGF protein in the interstitium (P<0.0001). In serial sections, VEGF colocalized with the expression of CD 68-positive macrophages. Significantly more macrophages were in the tubulointerstitium in tissue with chronic rejection than in those with temporary allograft dysfunction (P<0.005). Additionally, VEGF protein expression in the glomeruli and the vascular compartment of patients with chronic rejection was increased.

CONCLUSION

The up-regulation of VEGF in chronic renal allograft rejection may be important in inflammation and development of fibrosis.

Nonspecificity of monoclonal antibody Tordji-22 for the detection of hepatitis C virus in liver transplant recipients with cholestatic hepatitis

Detection of hepatitis C virus (HCV) antigens in liver tissue provides important diagnostic and pathological information. Limited studies have been performed on tissue taken after liver transplantation for HCV. In this study, serial post-liver transplantation biopsy tissue from patients with recurrent HCV was tested, with particular interest in patients showing severe cholestatic hepatitis. HCV-related antigens were detected using the commercial monoclonal antibody, Tordji-22. Initial results were promising, showing intense positive staining, especially in areas of hepatocyte ballooning. HCV-negative donor tissue was consistently negative by staining. However, as a final control for the level of tissue damage, HCV negative posttransplantation biopsy tissue showing hepatocyte ballooning was examined. These tissues also showed positive staining. All attempts to eliminate this nonspecific interaction failed. In conclusion, Tordji-22 was associated with nonspecificity in this posttransplantation population, and care is warranted when using this monoclonal antibody.

Paradoxical early immune activation during acceptance of liver allografts compared with rejection of skin grafts in a rat model of transplantation

Liver allografts in many animal models are often spontaneously accepted across a complete histocompatibility barrier without requirement for immunosuppression. In contrast, skin allografts are usually rejected, even across minor histocompatibility barriers. To identify the mechanism of liver allograft acceptance we have compared skin rejection with liver acceptance in DA rat strain recipients of PVG donors, a major histocompatibility complex (MHC) class I plus II mismatch. In spite of the established role of draining lymph nodes (LN) in induction of rejection of skin allografts, there was much greater involvement of LN after liver than after skin transplantation. Few donor cells migrated to these organs from transplanted skin but many cells migrated from transplanted liver. There was also a paradoxical increase in interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) mRNA in LN and spleen of liver allograft recipients that greatly exceeded their expression in skin allograft recipients. For example, there were 2. 7+/-1.6x104 molecules of IFN-gamma per 106 molecules of beta-actin mRNA in the LN draining liver allografts 1 day after transplantation compared with 2.0+/-0.3x103 molecules/106 beta-actin in LN draining skin allografts and 8.1+/-1.8x102 molecules/106 beta-actin in LN draining skin isografts. Examination of the graft showed that infiltration and cytokine mRNA up-regulation occurred more slowly in the transplanted skin than in liver but progressed inexorably in skin grafts until rejection. These results show that liver acceptance is associated with a paradoxical marked early activation then subsequent decline of the immune response.

Periacinar stellate shaped cells in rat pancreas: identification, isolation, and culture

BACKGROUND

The pathogenesis of pancreatic fibrosis is unknown. In the liver, stellate cells (vitamin A storing cells) play a significant role in the development of fibrosis.

AIMS

To determine whether cells resembling hepatic stellate cells are present in rat pancreas, and if so, to compare their number with the number of stellate cells in the liver, and isolate and culture these cells from rat pancreas.

METHODS

Liver and pancreatic sections from chow fed rats were immunostained for desmin, glial fibrillary acidic protein (GFAP), and alpha smooth muscle actin (alpha-SMA). Pancreatic stellate shaped cells were isolated using a Nycodenz gradient, cultured on plastic, and examined by phase contrast and fluorescence microscopy, and by immunostaining for desmin, GFAP, and alpha-SMA.

RESULTS

In both liver and pancreatic sections, stellate shaped cells were observed; these were positive for desmin and GFAP and negative for alpha-SMA. Pancreatic stellate shaped cells had a periacinar distribution. They comprised 3.99% of all pancreatic cells; hepatic stellate cells comprised 7.94% of all hepatic cells. The stellate shaped cells from rat pancreas grew readily in culture. Cells cultured for 24 hours had an angular appearance, contained lipid droplets manifesting positive vitamin A autofluorescence, and stained positively for desmin but negatively for alpha-SMA. At 48 hours, cells were positive for alpha-SMA.

CONCLUSIONS

Cells resembling hepatic stellate cells are present in rat pancreas in a number comparable with that of stellate cells in the liver. These stellate shaped pancreatic cells can be isolated and cultured in vitro.

Kinetics of intragraft cytokine expression, cellular infiltration, and cell death in rejection of renal allografts compared with acceptance of liver allografts in a rat model: early activation and apoptosis is associated with liver graft acceptance

BACKGROUND

Liver transplants in the rat strain combination PVG-to-Dark Agouti are spontaneously tolerated, whereas kidney transplants in the same strain combination are rejected in 7-9 days.

METHODS

To identify organ-specific differences that might yield further information about the mechanism of tolerance induction in this strain combination, liver or kidney grafts, spleen, and draining lymph nodes were harvested at days 1, 3, 5, and 7, and examined by immunohistochemistry, terminal deoxynucleotide transferase-mediated dUTP nick end labeling assay, and reverse transcriptase-polymerase chain reaction for interferon-gamma, interleukin (IL)-2, IL-4, and IL-10.

RESULTS

Renal allograft rejection was associated with the progressive development of an intense mononuclear cell infiltrate. Markers of lymphocyte activation and cytokine up-regulation appeared from day 3, and many apoptotic parenchymal cells were noted on days 5-7, at the peak of rejection. Conversely, liver allograft tolerance was associated with more rapid infiltration by activated T cells and earlier increases in cytokine expression, but with a more limited degree of cellular infiltration. Concurrent with the early activation, high levels of apoptosis were found in areas of leukocyte infiltrate, paralleling the disappearance of activated T cells from the graft between days 3 and 5.

CONCLUSIONS

Apoptosis of infiltrating leukocytes in liver allografts may represent an important process in the induction of spontaneous liver transplant tolerance and may underlie the abortive nature of the effector response observed within tolerated livers. In contrast, activated cells in renal allografts in the same strain combination survive and proliferate, express high levels of cytokines, and are efficient in bringing about graft destruction.

Cytochrome P4502E1 is present in rat pancreas and is induced by chronic ethanol administration

BACKGROUND

The mechanisms responsible for the initiation of alcoholic pancreatitis remain elusive. However, there is an increasing body of evidence that reactive oxygen species play a role in both acute and chronic pancreatitis. In the liver, cytochrome P4502E1 (CYP2E1, the inducible ethanol metabolising enzyme) is one of the proposed pathways by which ethanol induces oxidative stress.

AIMS

To determine whether CYP2E1 is present in the pancreas and, if so, whether it is inducible by chronic ethanol feeding.

METHODS

Eighteen male Sprague-Dawley rats were pair fed liquid diets with or without ethanol as 36% of energy for four weeks. CYP2E1 levels were determined by western blotting of microsomal protein from both pancreas and liver. Messenger RNA (mRNA) levels for CYP2E1 were quantified using dot blots of total pancreatic RNA.

RESULTS

CYP2E1 was found in the pancreas. Furthermore, the amount of CYP2E1 was greater in the pancreas of rats fed ethanol compared with controls (mean increase over controls 5.1-fold, 95% confidence intervals 2.4 to 7.7, p < 0.02). In the liver, induction by ethanol of CYP2E1 was similar (mean increase over controls 7.9-fold, 95% confidence intervals 5.2 to 10.6, p < 0.005). Pancreatic mRNA levels for CYP2E1 were similar in ethanol fed and control rats.

CONCLUSIONS

CYP2E1 is present in the rat pancreas and is inducible by chronic ethanol administration. Induction of pancreatic CYP2E1 is not regulated at the mRNA level. The metabolism of ethanol via CYP2E1 may contribute to oxidative stress in the pancreas during chronic ethanol consumption.

Transmission of hepatitis C virus to infants of human immunodeficiency virus-negative intravenous drug-using mothers: rate of infection and assessment of risk factors for transmission

The risk of perinatal transmission of hepatitis C virus (HCV) from a cohort of 95 human immunodeficiency virus (HIV)-negative intravenous drug users (IVDU) is described, 89 of whom were positive for antibodies to HCV (anti-HCV). Infection, defined as the presence of HCV RNA in a serum sample collected from an infant at any time during follow-up, was detected in six of 63 (9.5%) infants born to HCV antibody-positive viraemic mothers. No mother who was HCV RNA negative at delivery transmitted HCV to her infant. Hepatitis C virus antibodies became undetectable in uninfected infants by 15 months, but persisted in all HCV-infected infants throughout follow-up. An abnormal alanine aminotransferase (ALT) level was observed on at least one occasion in all HCV-infected infants and in six occasions in uninfected infants. Two of the six HCV-infected infants became HCV RNA negative during follow-up by 27 and 29 months. Both of these infants had a large ALT elevation (mean peak ALT 398U l-1) at around 12 months of age. Analysis of a range of potential risk factors revealed that maternal HCV RNA load was important in predicting transmission, but suggested that other factors play a role in perinatal transmission from mother to child. No difference was found between mothers who transmitted HCV to their infants and those who did not for HCV genotype, duration of drug use, duration of methadone use, methadone dose, history of alcohol abuse, past hepatitis B virus (HBV) infection, mode of delivery, maternal and gestational age, birth weight and incidence of breast-feeding. Mothers who transmitted HCV to their infants had a longer duration between membrane rupture and delivery than the mothers who did not transmit (P = 0.03). HCV RNA was not detected in breast milk and colostrum samples from 38 viraemic mothers, including two who transmitted HCV to their infant.

Cholestatic hepatitis after liver transplantation is associated with persistently high serum hepatitis C virus RNA levels

Viral recurrence is universal after transplantation for hepatitis C infection. This may lead to difficulties in differentiating allograft dysfunction caused by chronic rejection from hepatitis C virus (HCV) recurrence. Cases of severe cholestatic hepatitis have also been reported in conjunction with reinfection of the graft with HCV. Patients receiving transplants for HCV-related liver disease were studied before and after transplantation by HCV RNA quantitation of serial serum samples. Four major clinical patterns of HCV recurrence could be distinguished posttransplantation: group 1, asymptomatic hepatitis with no significant symptoms; group 2, cholestatic hepatitis with centrilobular ballooning; group 3, hepatitis leading to chronic allograft rejection; and group 4, persistently normal serum aminotransferase levels. Pretransplantation viral load was shown to be an important indicator of disease severity because the group 2 patients had significantly higher pretransplantation viral loads than patients in group 1 (P = 0.01) and group 4 (P = 0.005). The group 2 patients also had persistently significantly higher posttransplantation viral loads than the patients in group 1 (P = 0.01) and group 4 (P = 0.02), whereas patients who developed chronic allograft rejection showed marked decreases in serum HCV RNA before retransplantation. Patients from group 4 had the lowest viral loads after transplantation. These results show that persisting graft cholestasis due to HCV is associated with persistently high HCV RNA levels compared with other etiologies of graft dysfunction. Prospective studies are needed to determine whether such quantitation may be diagnostically helpful in distinguishing the different patterns of HCV-related graft dysfunction observed after liver transplantation.

Sequential increases in the intrahepatic expression of epidermal growth factor, basic fibroblast growth factor, and transforming growth factor beta in a bile duct ligated rat model of cirrhosis

Chronic hepatic regeneration constitutes an important part of the cirrhotic process. The factors regulating chronic hepatic regeneration, however, remain unclear. We therefore analyzed the intrahepatic messenger RNA (mRNA) expression of growth factors (epidermal growth factor [EGF], basic fibroblast growth factor [bFGF], hepatocyte growth factor [HGF], transforming growth factor [TGF]-alpha, and TGF-beta) at progressive time points (postoperative days 2, 7, 14, and 21) in a rat bile duct-ligated (BDL) model of cirrhosis versus sham controls. Intrahepatic growth factor mRNA expression was quantitatively assessed by polymerase chain reaction (PCR) using a dot-blot hybridization technique. Cirrhosis was associated with statistically significant (P < .05) progressive increases in the intrahepatic mRNA expression of bFGF (80-fold), EGF (25-fold), and TGF-beta (fourfold) in BDL animals versus controls. Furthermore, immunohistochemistry of hepatic sections showed a progressive up-regulation of bFGF protein in areas of bile duct proliferation. These areas also showed a dramatic increase in the number of hepatic stellate cells (HSC). In contrast, the intrahepatic expression of hepatocyte growth factor (HGF) mRNA was only significantly increased at postoperative days 7 and 14 in BDL animals before returning to control levels as cirrhosis developed. There were no significant differences found at any timepoint in the expression of TGF-alpha in BDL animals versus controls. In conclusion, the development of cirrhosis in this BDL rat model was associated with a progressive increase in the intrahepatic expression of EGF, bFGF, and TGF-beta. Early increased expression of HGF was not maintained in established cirrhosis. The findings suggest that these growth factors may play important roles in the pathogenesis of chronic hepatic regeneration in cirrhosis.

Systematic review of role of polymerase chain reaction in defining infectiousness among people infected with hepatitis C virus

OBJECTIVE

To assess the role of polymerase chain reaction in defining infectiousness among people infected with hepatitis C virus.

DESIGN

Published studies of hepatitis C transmission were examined. Twenty nine studies with identified sources of hepatitis C infection who were tested for presence of hepatitis C RNA by polymerase chain reaction were reviewed, including studies of vertical transmission (n = 21), transmission after transplantation (n = 3), transfusion of blood components (n = 3), and needlestick exposure (n = 2).

SUBJECTS

All patients identified in studies.

RESULTS

A total of 2022 people who had been exposed to sources positive for antibody to hepatitis C were identified. Among 1148 people exposed to sources positive by polymerase chain reaction 148 cases of transmission occurred compared with no definite case among 874 people exposed to negative sources. Rates of transmission from positive sources were 6.2% for perinatal exposure, 6.1% after needlestick exposure, 78% after solid organ or bone marrow transplantation, and 83% after transfusion of blood components. Other factors influencing risk of vertical transmission were coinfection with HIV and level of hepatitis C viraemia.

CONCLUSIONS

Negative results by polymerase chain reaction indicate an extremely low probability of transmission of hepatitis C from a person with antibody to hepatitis C.