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W J Hofmann

Publications and source records attributed to W J Hofmann.

At least 37 records · Page 2Linked to original sources
PubMed1999

Fatal course of veno-occlusive disease of the liver (endophlebitis hepatica obliterans) in a preterm infant.

We describe the fatal course of a preterm infant of 34 weeks' gestation with veno-occlusive disease of the liver and refractory ascites. Despite aggressive medical management, the baby died twenty-two hours post partum because of cerebral haemorrhage before potentially life-saving organ transplantation could take place. At autopsy, paucity of lymphoid tissue in lymph nodes, thymus, spleen, and gastrointestinal tract were also seen. To our knowledge, this is the youngest infant with veno-occlusive disease of the liver reported in the literature.

Adult↗
PubMed1999

CDKN2 mutation is infrequent in german hepatocellular carcinoma.

For hepatocellular carcinoma, only scarce and controversial data on CDKN2 alterations are available. A high rate of mutations in a Chinese study contrasts with a low rate found in Japanese tumors and a CDKN2 germline mutation in 4/26 Swiss tumors examined. We analyzed 23 hepatocellular carcinomas from German patients for homozygous deletions of CDKN2 by coamplification with the human tyrosine hydroxylase (TH) gene and for CDKN2 mutations by PCR-single strand conformation polymorphism analysis and direct DNA sequencing. Our results indicate the lack of homozygous deletions. In one tumor, DNA sequencing showed a GCG-ACG (alanine-threonine) substitution at codon 148, a polymorphism in exon 2 of CDKN2. We conclude that the alteration of CDKN2 by deletion or mutation appears not to be a frequent event in hepatocarcinogenesis in German patients.

Adolescent↗
PubMed1999

Beta-catenin accumulation and mutation of the CTNNB1 gene in hepatoblastoma.

Hepatoblastoma is a rare malignant tumor of the liver that occurs in children at an average age of 2 to 3 years. Epidemiologic studies have shown an increased frequency of this tumor type in families affected by adenomatous polyposis coli. In addition to the epidemiologic data, molecular genetic studies suggest that inactivation of the APC tumor suppressor may be involved in hepatoblastoma tumorigenesis. A major function of APC is the downregulation of beta-catenin, a transcription-activating protein with oncogenic potential. In an ongoing immunohistochemical study of beta-catenin expression in sporadic cases of tumor types that are associated with adenomatous polyposis coli, we observed increased beta-catenin levels in the cytoplasm and in the nuclei of three investigated hepatoblastomas. Sequencing of exon 3 of the beta-catenin gene (CTNNB1) revealed an activating mutation in one of the tumor samples. Our data indicate for the first time that beta-catenin accumulation may play a role in the development of hepatoblastoma and that activating mutations of the beta-catenin gene may substitute biallelic APC inactivation in this tumor type. Genes Chromosomes Cancer 25:399-402, 1999.

Cadherins↗
PubMed1998

Expression of hepatitis B virus X protein in HBV-infected human livers and hepatocellular carcinomas.

Transactivation of cellular genes and functional inactivation of p53 by the hepatitis B virus (HBV) X gene-encoded protein (HBx) are proposed as alternative mechanisms for induction of hepatocellular carcinomas (HCCs) in chronic HBV infection. Using an immunohistochemical approach, we studied the expression of HBx in 39 explanted livers with HBV-associated disease. Because the data reported previously have been inconsistent, possibly due to the application of different antibodies, we compared results with 5 polyclonal and 6 monoclonal anti-HBx antibodies from five laboratories. Ten of the 11 antibodies reacted with recombinant HBx by Western blotting, but only 1 polyclonal and 2 monoclonal antibodies reacted specifically with HBx in tissue, and were thus suitable for immunohistochemistry. Three other polyclonal antibodies reacted with tissue components in addition to HBx. One polyclonal and 4 monoclonal antibodies did not recognize the HBx in the tissue. HBx was demonstrated in 16 of 30 (53.3%) cirrhotic livers and 10 of 18 (58.8%) HCCs by all specific antibodies. The expression of HBx, among three HBV antigens examined, was found to be preferentially maintained in HCC and the surrounding liver parenchyma, including focal or nodular preneoplastic lesions. However, the immunoreactivity was always limited to the cytoplasm of a small number of parenchymal and neoplastic cells. The role of X gene expression in HBV-associated human hepatocarcinogenesis remains to be established.

Animals↗
PubMed1998

The efficacy of N-acetylcysteine as a hepatoprotective agent in liver transplantation.

One of the most common complications after liver transplantation is primary graft dysfunction which results from severe deterioration of the microcirculation. The data obtained from our experimental studies indicate that N-acetylcysteine (NAC) is able to reduce the severity of ischemia/reperfusion injury and improves postoperative graft function after liver transplantation in rats. The aim of this pilot study was to evaluate the efficacy of NAC as a hepatoprotective agent under clinical conditions. A group of 30 liver transplanted patients were treated with NAC, and 30 patients (control group) were treated with a 5% solution of glucose only. In the NAC group we observed a distinct reduction in ischemia/reperfusion injury and improved liver function with less elevated peak transaminases, better macrocirculation, improved liver synthesis function and a lower incidence of primary nonfunction compared with the control group. We conclude that NAC is a very promising substance for reducing graft dysfunction in clinical liver transplantation.

Acetylcysteine↗
PubMed1998

The distribution of HBV, HCV and HGV among livers with fulminant hepatic failure of different aetiology.

BACKGROUND/AIMS: The aim of the study was to assess the impact factor of HCV and HGV in fulminant hepatic failure. METHODS: The 5'-untranslated regions of HCV RNA and HGV RNA and a segment of the core antigen sequence of HBV were amplified after extracting the nucleic acids from snap-frozen tissue aliquots from explanted livers of 26 consecutive patients undergoing orthotopic liver transplantation for fulminant hepatic failure preoperatively diagnosed as either autoimmune (n=2), HAV/HBV (n=8), toxic (n=4) or aetiologically unknown (n=12). RESULTS: HCV RNA was detected in five of 26 (19.2%) livers with fulminant hepatic failure. All five HCV RNA-positive livers belonged to the group of non-toxic, non-autoimmune liver failure (n=20), three of them were found in the group of liver failure with unknown aetiology (n=12) and two in the group of HBV-associated liver failure (n=7), making an HCV incidence of 25%, 25% and 28.6%, in the different groups, respectively. HGV RNA was detected in 10 of 17 (58.8%) explants and in all four groups of fulminant hepatic failure as defined preoperatively. HBV DNA was identified in six livers of 26 patients (23.1%) with fulminant hepatic failure. Neither HCV RNA nor HBV DNA was detected in the livers of patients with toxic or autoimmune fulminant hepatic failure. CONCLUSIONS: These results indicate that HBV and HCV, but not HGV, play an aetiologic role in fulminant hepatic failure. HCV-positive cases were concentrated either in the group of otherwise unexplained fulminant hepatic failure or in the group of HBV fulminant hepatic failure. HGV-positive cases, on the other hand, were found within all four preoperatively defined groups, indicating a role as cofactor rather than as single aetiologic agent.

Adolescent↗
PubMed1998

Hepatic failure and liver cell damage in acute Wilson's disease involve CD95 (APO-1/Fas) mediated apoptosis.

Wilson's disease can result in fulminant liver failure due to hepatic copper overload. The CD95 system mediates apoptosis and has been demonstrated to be involved in liver disease. In this study CD95 mediated apoptosis was investigated in patients with fulminant hepatic failure in the course of Wilson's disease and in an in vitro model of copper treated human hepatoma cells. In patients, hepatic expression of CD95 and CD95L mRNA and apoptosis were detected. Copper overload in vitro resulted in hepatocytic apoptosis which could be reduced with a neutralizing anti-CD95L antibody. Copper treatment of hepatocytes results in activation of the CD95 system and induction of apoptosis which is operative during the course of hepatic failure in acute Wilson's disease.

Acute Disease↗
PubMed1998

Survival and recurrence after liver transplantation versus liver resection for hepatocellular carcinoma: a retrospective analysis.

OBJECTIVE: This study compares the results of liver transplantation (LTx) and liver resection (LR) for hepatocellular carcinoma (HCC) to test the widespread hypothesis that LTx is the preferable approach for small HCCs. SUMMARY BACKGROUND DATA: With respect to scarcity of donor organs and poor results, LTxs for large HCCs are obsolete. Small HCC transplantations have been reported to result in an excellent survival rate. However, the data of comparative studies are controversial. METHODS: Patients who were treated curatively by LTx (n = 50) or LR (n = 52) for HCC were included in this retrospective study. Survival and freedom from recurrence were analyzed. Patients were stratified according to prognostic factors (pT classification, tumor size, number of tumor nodules, vascular infiltration, and cirrhosis). RESULTS: Overall, after LTx and LR the 3-year survival rate and recurrence rate were not significantly different. In the Cox analysis, tumor size (p = 0.02) and vascular infiltration (p = 0.04) were independent variables after LTx, whereas after LR, none of the tested prognostic parameters was significant. With regards to recurrence, tumor size was the only independent factor, after both LTx and LR (p = 0.02, respectively). Directly comparing the two therapeutic approaches, a 3-year survival rate in pT 1/2, oligocentric (1-5 nodules), and oligocentric and small tumors proved to be superior after LTx. The recurrence rate after LTx was superior to LR in pT 1/2 and oligocentric tumors. Remarkably, for small (< or = 5 cm) tumors, LTx and LR resulted in a similar 3-year survival rate and freedom from recurrence. CONCLUSIONS: According to our analysis, the oncological advantage of LTx compared with LR is questionable. This applies especially for small tumors. Superior results of LTx in early stage HCC and particularly in oligocentric tumors may be attributed to incorrect preoperative diagnosis. Nevertheless, LTx is a reasonable treatment for patients with early stage tumors if a LR is impossible because of tumor localization or poor functional hepatic capacity.

Adult↗
PubMed1997

Disrupted IGF2 promoter control by silencing of promoter P1 in human hepatocellular carcinoma.

Previous investigations have supported or indicated a stimulatory role of the insulin-like growth factor II gene (IGF2) in hepatocarcinogenesis. We have studied the transcript levels, promoter usage, and imprinting status of the ICF2 gene and its relationship to H19 in human hepatocellular carcinomas (HCCs) and liver tumor cell lines. The activity of the IGF2 promoter P1 was lost in about 70% of the cases (18 of 25). This is the most prominent abnormality regarding the IGF2 regulation in this study. Total IGF2 as well as promoter P3 transcription were up-regulated in a small group of the tumors. Twenty genetically informative cases were obtained from 26 cases, thus excluding the probability of loss of heterozygosity of the IGF2 gene. Among these, nine showed abnormal monoallelic expression of IGF2. One HCC and one HCC cell line proved loss of functional imprinting of IGF2. H19 and IGF2 were regulated in parallel, and expression levels were variable. Taken together, the disruption of the IGF2 promoter regulation, particularly the loss of P1 activity, is a common feature of human HCCs. The loss of P1 activity explains the frequent loss of biallelic IGF2 expression and may potentially be used as a diagnostic or monitoring marker for human HCC.

Alleles↗
PubMed1997

Drug-induced apoptosis in hepatoma cells is mediated by the CD95 (APO-1/Fas) receptor/ligand system and involves activation of wild-type p53.

Chemotherapeutic drugs are cytotoxic by induction of apoptosis in drug-sensitive cells. We investigated the mechanism of bleomycin-induced cytotoxicity in hepatoma cells. At concentrations present in the sera of patients during therapy, bleomycin induced transient accumulation of nuclear wild-type (wt) p53 and upregulated expression of cell surface CD95 (APO-1/Fas) receptor in hepatoma cells carrying wt p53 (HepG2). Bleomycin did not increase CD95 in hepatoma cells with mutated p53 (Huh7) or in hepatoma cells which were p53-/- (Hep3B). In addition, sensitivity towards CD95-mediated apoptosis was also increased in wt p53 positive HepG2 cells. Microinjection of wt p53 cDNA into HepG2 cells had the same effect. In contrast, bleomycin did not enhance susceptibility towards CD95-mediated apoptosis in Huh7 and in Hep3B cells. Furthermore, bleomycin treatment of HepG2 cells increased CD95 ligand (CD95L) mRNA expression. Most notably, bleomycin-induced apoptosis in HepG2 cells was almost completely inhibited by antibodies which interfere with CD95 receptor/ligand interaction. These data suggest that apoptosis induced by bleomycin is mediated, at least in part, by p53-dependent stimulation of the CD95 receptor/ligand system. The same applies to other anti-cancer drugs such as cisplatin and methotrexate. These data may have major consequences for drug treatment of cancer and the explanation of drug sensitivity and resistance.

Antibodies, Blocking↗
PubMed1997

[The clinical significance of renal cell carcinoma in dialysis dependent patients in comparison with kidney transplant recipients].

The clinical relevance of de novo Renal Cell Cancer was compared in chronic hemodialysis patients and renal allograft recipients. Clinical course of these patients was followed for 15 years. 21 of 788 patients who underwent radical nephrectomy were suffering from renal insufficiency at the time of surgery. Evaluated data included clinical symptoms; tumor histology and clinical course. 19 patients received chronic hemodialysis treatment. 7 patients demonstrated stable function of the allograft. 92% of patients receiving hemodialysis treatment did not show metastasis and none died of renal cell carcinoma. On the contrary, 71% of patients who underwent renal transplantation showed advanced tumor disease or metastasis. 3 patients have died of RCC. Aggressive tumor growth of RCC requires close follow up in patients who received a renal allograft.

Adult↗
PubMed1997

Human hepatic preneoplasia: phenotypes and proliferation kinetics of foci and nodules of altered hepatocytes and their relationship to liver cell dysplasia.

Foci of altered hepatocytes (FAH) represent preneoplastic lesions, as shown in various animal models of hepatocarcinogenesis, but their significance in the human liver has not been established. The cellular composition, size distribution and proliferation kinetics of FAH in 163 explanted and resected human livers with or without hepatocellular carcinoma (HCC) and their possible association with small-cell change of hepatocytes (SCC) were therefore studied. FAH, including glycogen-storing foci, were found in 84 of 111 cirrhotic livers, demonstrating higher incidences in cases with (29/32) than in those without HCC (55/79). FAH were observed more frequently in HCC-free cirrhosis associated with hepatitis B or C virus or chronic alcoholic abuse (high-risk group) (37/47) than in that due to other causes (low-risk group) (12/21). MCF, predominant in cirrhotic livers of the high-risk group, were more proliferative, larger and more often involved in formation of nodules of altered hepatocytes (39.3%) than were GSF (8.5%). The results suggest that the FAH are preneoplastic lesions, MCF being more advanced than GSF. Oncocytic and amphophilic cell foci were also observed, but their significance remains to be clarified. Two types of SCC, namely diffuse and intrafocal SCC, were identified, but only intrafocal SCC was found to be related to increased proliferative activity and more frequent nodular transformation of the FAH involved, suggesting a close association with progression from FAH to HCC.

Adolescent↗
PubMed1997

Recurrent hepatitis C virus infection after liver transplantation--long-term follow-up with respect to the HCV genotypes/subtypes.

BACKGROUND/AIMS: Various factors may affect the postoperative course in recurrent hepatitis C virus (HCV) infection after liver transplantation (OLT). The aim of our study was to evaluate the potential role of HCV genotypes and immunosuppressive treatment. METHODS: 17 liver allograft recipients, HCV-RNA positive prior to OLT, were followed 26-102 months postoperatively. The diagnosis of HCV infection was based on clinical, serological and histological findings and detectable HCV-RNA in serum. The genotypes/subtypes were evaluated by a "reverse line probe" assay. RESULTS: After OLT hepatitis C viremia was evident in 16 of 17 allograft recipients (94%). Two patients acquired HCV infection after transplantation (incidence 0.84%). Clinically eight of 18 viremic patients remained asymptomatic. Ten of 18 had an acute hepatitis (eleven to 27 weeks after OLT), of those nine patients developed chronic hepatitis (hepatic activity indices: grade 1-3) with progression to fibrosis in two patients. One patient subsequently developed cirrhosis. Subtype 1 b was predominant (eleven of 18 patients). After transplantation subtype 1 b was not associated with a higher rate of recurrent hepatitis compared to other genotypes/subtypes (45% in type 1 b vs. 71% in type "non-1 b"; n.s.). CONCLUSION: Identical HCV genotypes/subtypes before and after OLT indicate a recurrent rather than a postoperatively acquired HCV infection of the allograft. Despite viremia most patients had no or mild to moderate hepatitis in the long-term follow-up. Different HCV genotypes were not associated with specific clinical courses of recurrent HCV infection after OLT.

Adolescent↗
PubMed1996

Aspergillus endocarditis, myocarditis and pericarditis complicating necrotizing fasciitis. Case report and subject review.

A patient with Aspergillus endocarditis, myocarditis and pericarditis is described. A 55-year-old man developed necrotizing fasciitis of the lower abdominal wall, pelvis and right thigh. Despite aggressive surgical débridement and antibiotic coverage, the patient died of multisystem organ failure. Autopsy revealed Aspergillus thromboulcerative endocarditis, myocarditis and pericarditis, acute necrotizing fungal bronchopneumonia and mycotic dissemination to brain, kidney and thyroid gland. A review of the literature showed that in the absence of open-heart surgery Aspergillus endocarditis and myocarditis are very uncommon.

Aspergillosis↗
PubMed1996

Lymphocyte apoptosis induced by CD95 (APO-1/Fas) ligand-expressing tumor cells--a mechanism of immune evasion?

The CD95 (APO-1/Fas) system is an important mediator of T-cell cytotoxicity. We investigated this system in 22 hepatocellular carcinomas (HCCs) from patients. All HCCs had partially or completely lost the expression of the CD95 receptor constitutively expressed by normal liver cells and might thus evade CD95-mediated killing. We also considered a new mechanism of immune evasion, namely, the active destruction of T-lymphocytes by tumor cells expressing CD95 ligand (CD95L). CD95L messenger RNA and protein could be detected in the HCCs. In coculture experiments, HepG2 hepatoblastoma cells, expressing CD95L mRNA after treatment with cytostatic drugs, killed CD95+ Jurkat lymphocytes. Our data suggest that tumor cells can evade immune attack by down-regulation of the CD95 receptor and killing of lymphocytes through expression of CD95L.

Antimetabolites, Antineoplastic↗