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Biomedical subjects

L Theilmann

Publications and source records attributed to L Theilmann.

At least 19 recordsLinked to original sources

[Angiomyolipoma of the liver].

HISTORY AND ADMISSION FINDINGS: A 66-year-old woman, known for 4 years to have a space-occupying lesion in the liver thought to be a lipoma, was admitted because the increasing size of the mass. She was hypertensive and had recurrent supraventricular tachycardia, but was otherwise asymptomatic and physical examination was unremarkable. INVESTIGATIONS: Laboratory tests were within normal limits. Abdominal ultrasound demonstrated a well-circumscribed, echodense space-occupying lesion. Magnetic resonance imaging revealed a hyperintense encapsulated tumour with contrast-medium enhancement. DIAGNOSIS AND TREATMENT: Because the imaging tests were equivocal, a segmental liver resection was performed to exclude malignancy. Histological examination revealed an angiomyolipoma of the liver. CONCLUSION: Angiolipoma is a benign mixed-cell tumour that very rarely affects the liver but must be included in the differential diagnosis of hepatic space-occupying lesions. Its manifestations may be highly variable and histological examination is required if there is any uncertainty about possible malignancy. If the biopsy is diagnostic of a benign lesion, expectant observation with regular monitoring is indicated.

Aged↗

Replication of subgenomic hepatitis C virus RNAs in a hepatoma cell line.

An estimated 170 million persons worldwide are infected with hepatitis C virus (HCV), a major cause of chronic liver disease. Despite increasing knowledge of genome structure and individual viral proteins, studies on virus replication and pathogenesis have been hampered by the lack of reliable and efficient cell culture systems. A full-length consensus genome was cloned from viral RNA isolated from an infected human liver and used to construct subgenomic selectable replicons. Upon transfection into a human hepatoma cell line, these RNAs were found to replicate to high levels, permitting metabolic radiolabeling of viral RNA and proteins. This work defines the structure of HCV replicons functional in cell culture and provides the basis for a long-sought cellular system that should allow detailed molecular studies of HCV and the development of antiviral drugs.

Carcinoma, Hepatocellular↗

Hepatotropism of GB virus C (GBV-C): GBV-C replication in human hepatocytes and cells of human hepatoma cell lines.

BACKGROUND/AIMS: Recently, GB virus C (GBV-C) has been identified as another virus potentially causing viral hepatitis. However, its hepatotropism and pattern of infection in humans is still unknown. To elucidate the presence and replication of GBV-C in the human liver, we investigated tissue samples of six explanted livers from five GBV-C mono- or GBV-C/HCV co-infected patients for GBV-C RNA plus- and minus-strand RNA. METHODS: These tissues were examined using nested RT-PCR followed by Southern blot hybridization as well as fluorescence in situ hybridization on liver cryosections. To further substantiate susceptibility of liver cells for GBV-C, in vitro infection of human hepatoma cells (HuH7, HepG2) with GBV-C mono-infected serum was performed. RESULTS: By reverse transcription followed by nested PCR (RT-PCR), 5 of 6 liver specimens (4/5 patients) were positive for GBV-C plus-strand RNA, and viral minus-strand RNA could be detected in 4 of 6 liver specimens (4/5 patients). One liver sample was negative for GBV-C RNA. In two specimens we could identify GBV-C infection by in situ hybridization. Virus infection appeared to be restricted to hepatocytes and detection of minus-strand RNA showed viral replication in a few highly infected liver cells. In vitro infection of HepG2 or HuH7 cells confirmed these findings by a release of virions into supernatant. CONCLUSION: In conclusion, our results establish GBV-C as a hepatotropic virus infecting human cells of hepatic origin in vivo and in vitro.

Carcinoma, Hepatocellular↗

Clinical relevance of hepatitis G virus (HGV) infection in heart transplant patients.

To investigate whether the recently discovered hepatitis G virus (HGV) influences the clinical outcome of heart transplant recipients under immunosuppression, we determined the prevalence of HGV infections correlated with liver function and survival in 51 patients. Presence of HGV RNA and anti-E2, a marker for resolved HGV infection, were serially tested in sera from patients before and after heart transplantation (HTX) by nested RT-PCR and ELISA. Four of 51 (7.8%) patients before transplantation, and 22 of 50 patients (44%) after transplantation showed signs of persistent or resolved HGV infection. HGV infection was not associated with impairment of liver function or with patient survival. In summary, presence of HGV infection does not influence the clinical outcome in heart transplant patients.

Enzyme-Linked Immunosorbent Assay↗

Incidence, prevalence, and clinical outcome of hepatitis GB-C virus infection in liver transplant patients.

A novel RNA virus of the Flaviviridae family has been discovered recently and designated hepatitis GB-C virus (GBV-C). Previous studies have reported that GBV-C is associated with posttransfusion hepatitis, chronic viral hepatitis, and cryptogenic hepatitis. However, the clinical significance of GBV-C infection has been questioned increasingly in patients not undergoing transplantation. To investigate whether GBV-C infection under immunosuppression affects the clinical or the histological outcome in liver transplant recipients, we determined the prevalence and incidence of GBV-C infections and the clinical and histological signs in patients after orthotopic liver transplantation (OLT). The presence of GBV-C was tested in sera from patients before and in regular intervals up to 6 years after OLT by nested reverse transcription-polymerase chain reaction using primers derived from the NS3 region. A total of 72 patients were studied. Before OLT, 8 of 72 (11.1%) patients were positive for GBV-C. After OLT, 7 of 8 (87.5%) remained positive. Of 64 patients who were negative for GBV-C before OLT, 23 became positive after OLT, resulting in a de novo rate of GBV-C infection of 35.9%. We could not detect a higher rate of histologically proven hepatitis in GBV-C-positive patients (29.1%) than in GBV-C-negative patients (14.6%, P > 0.057). Comparing GBV-C-positive with GBV-C-negative liver transplant patients, we could not find any differences in age, gender, liver function tests, number of blood transfusions, histological degree of hepatitis, or number of rejection episodes. Survival was not negatively influenced by GBV-C positivity. In conclusion, the presence of GBV-C did not influence the clinical or histological outcome in liver transplant patients.

Adult↗

Extrahepatic and intrahepatic replication and expression of hepatitis C virus.

In order to determine the replication sites of hepatitis C virus, the in situ hybridization and immunohistochemical technique using digoxin-labeled 531 bp plus-strand and minus-strand HCVRNA probes were employed to detect HCVRNA in the liver tissues, bone marrow mononuclear cells and peripheral blood mononuclear cells (PBMCs) from the patients with chronic hepatitis C, and in HCV transfected COS cells. The results showed that both plus-strand and minus-strand HCVRNA were detected in 80% of liver tissues (4/5). Plus-strand HCVRNA could be detected in 90% of PBMCs and bone marrow mononuclear cells (18/20), minus-strand HCVRNA in 25% of PBMCs. In HCV transfected COS cells, plus-strand HCVRNA distributed evenly in 20% cellular nuclei and cytoplasms. No minus-strand HCVRNA was detected in the bone marrow mononuclear cells and HCV transfected COS cells. The positive signal appeared in more cells when the liver tissues, PBMCs and marrow mononuclear cells were hybridized by plus-strand probes than when hybridized by minus-strand probes. Our results suggested that the hepatocytic cytoplasms and PBMC cytoplasms were the replication sites of HCV, but the marrow mononuclear cells were not the replication sites of HCV although they were infected by HCV. HCV infection might be accounted for the pathogenesis of chronic hepatitis and relapse of hepatitis C after liver transplantation.

Animals↗

Establishment of a highly specific detection system for GB virus C (GBV-C) minus-strand RNA.

Although the clinical relevance of GB virus C (GBV-C) is still elusive, this virus has been found with high prevalence in several groups of patients with liver disease. As was shown for hepatitis C virus (HCV), minus-strand RNA is supposed to function as a replicative intermediate. We have established a reliable and sensitive detection system for GBV-C minus-strand RNA based on nested RT-PCR (reverse transcription-polymerase chain reaction) with a tagged primer system. Sensitivity and specificity was extensively tested using in-vitro transcribed GBV-C sequences and genomic viral RNA. Specificity of the amplified fragments was proven by Southern blot hybridization. Using this detection system, we found the presence of GBV-C minus-strand RNA in 6/41 (14.6%) sera of GBV-C infected or GBV-C/HCV coinfected patients. No correlation with virological parameters such as amount of GBV-C plus-strand RNA, genotype or titer of HCV could be detected.

Adult↗

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↗

Induction of tumour necrosis factor (TNF) receptor type p55 and p75 in patients with chronic hepatitis C virus (HCV) infection.

There is evidence that TNF-alpha contributes to the pathogenesis of chronic viral hepatitis. The cellular effects of this cytokine are regulated by two specific receptors, and membranous shedding of these receptors reflects activation of the TNF system. We performed a study of TNF-alpha and functionally active soluble TNF-receptors (TNFR-p55 and -p75) in 105 patients with chronic HCV infection. In HCV RNA-positive patients a significant enhancement of TNF-alpha and both receptor types was observed compared with controls (TNF-alpha 83.8+/-91.7 pg/ml versus 18.8+/-8.4 pg/ml, P<0.001; TNFR-p55 1.4+/-0.4 ng/ml versus 0.9+/-0.2 ng/ml, P<0.0001; TNFR-p75 6.4+/-2.4 ng/ml versus 2.9+/-0.6 ng/ml, P<0.0001, respectively). The enhanced serum levels of TNF-alpha and TNFRs were reflected by a significant expression of TNFR-specific mRNA in peripheral mononuclear cells of HCV-infected patients (P<0.001). Serum aminotransferases correlated with soluble TNFR-p75 (P<0.001) but not with TNFR-p55 and TNF-alpha. We demonstrated an association of the degree of histological inflammation with both TNFRs (P<0.01). Furthermore, enhanced hepatocellular expression of TNF-alpha and TNFRs could be demonstrated by immunohistochemical staining in HCV-infected patients. Sixty-eight out of 105 patients were treated with interferon-alpha (IFN-alpha) (3x10(6)U x 3/week). Pretreatment levels of TNF-alpha and TNFRs did not differ between responders and non-responders. Our results demonstrate that TNF-alpha and TNFRs are enhanced in chronic HCV infection and reflect histological activity of the disease. This up-regulation of TNFRs might modify host response and potentially contribute to liver damage in chronic HCV infection.

Adult↗

Adjuvant treatment with ursodeoxycholic acid may reduce the incidence of acute cardiac allograft rejection.

BACKGROUND: The nontoxic bile acid, ursodeoxycholic acid (UDCA), is an effective drug for the treatment of different cholestatic conditions. Furthermore, an immunomodulatory capacity of UDCA has been reported in vitro, as well as in vivo, in different immune-mediated liver diseases and after liver transplantation. METHODS: In this retrospective study, the influence of UDCA on heart transplant rejection was investigated in 21 cardiac allograft recipients receiving UDCA for cyclosporine-induced cholestasis (500 mg administered twice daily, start of therapy within the first postoperative month, duration >8 weeks). Thirty-one patients not receiving UDCA served as control subjects. All patients received triple-maintenance immunosuppression (cyclosporine, azathioprine, prednisolone). For quantitative comparison of rejection severity, the following score was applied: 0, no specific therapy; 1, temporary increase in oral steroids; 2, intravenous steroids; 3, ATG or OKT3 therapy. RESULTS: During the first 6 postoperative months, the number of acute rejection episodes requiring specific anti-rejection therapy was significantly lower in the UDCA group as compared with control subjects (1.38 +/- 1.36 vs 2.74 +/- 1.83 rejection episodes per patient, p = 0.005). The cumulative score was significantly lower in the UDCA group as compared with control subjects (2.38 +/- 2.29 vs 5.06 +/- 3.61, p = 0.004). CONCLUSIONS: These initial data indicate a beneficial effect of adjuvant UDCA treatment in the early phase after heart transplantation probably related to immunomodulating properties of UDCA, which may be used therapeutically after organ transplantation.

Acute Disease↗

MRI findings in chronic hepatic encephalopathy depend on portosystemic shunt: results of a controlled prospective clinical investigation.

BACKGROUND/AIMS: Deterioration of hepatic encephalopathy is a major concern with the transjugular intrahepatic portosystemic shunt procedure. Symmetric hyperintense globus pallidus on T1-weighted cranial magnetic resonance imaging in patients with liver cirrhosis anticipates hepatocerebral disease. It is hypothesized that hepatic encephalopathy and basal ganglia signal intensity progress in patients with cirrhosis of the liver undergoing transjugular intrahepatic portosystemic shunt. METHODS: Twenty-four patients were randomized to undergo either transjugular intrahepatic portosystemic shunt or elective sclerotherapy. At study entry and 6 months after randomization, neurologic assessment, psychometric tests, standard EEG, and magnetic resonance imaging were performed. The severity of liver failure was graded using Child-Pugh's classification. The signal intensity of the globus pallidus was determined on sagittal T1-weighted magnetic resonance imaging. RESULTS: The T1-weighted signal intensity of the globus pallidus on magnetic resonance imaging significantly increased after transjugular intrahepatic portosystemic shunt placement (p<0.01), but not with elective sclerotherapy. At follow-up, neurological symptoms indicating decline of mental status and motor performance were somewhat more prevalent in transjugular intrahepatic portosystemic shunt patients. Significant deterioration of EEG abnormalities occurred in patients treated with transjugular intrahepatic portosystemic shunt as opposed to elective sclerotherapy (p<0.01). CONCLUSIONS: Transjugular intrahepatic portosystemic shunt procedure increases hyperresonant globus pallidus on magnetic resonance imaging. Neuropsychiatric evaluation shows advancing hepatic encephalopathy, in particular with transjugular intrahepatic portosystemic shunt; however, it does not parallel the augmentation of pallidal signal intensity on magnetic resonance imaging.

Adult↗

Clinical presentation of GB-C virus infection in drug abusers with chronic hepatitis C.

BACKGROUND/AIMS: Recently, the hepatitis GB-C virus (GBV-C) has been identified as another virus potentially causing chronic hepatitis. Although high rates of coinfection are emerging in drug addicts with chronic hepatitis C virus infection, no detailed data on clinical presentation are available. Therefore, co-infection was sought in hepatitis C virus patients to determine the impact of GB-C virus on clinical presentation. METHODS: GBV-C was determined by nested reverse transcriptase-polymerase chain reaction in serum of 70 HIV negative intravenous drug abusers with chronic hepatitis C. Biochemical, histological and virological parameters were compared between patients with or without GBV-C coinfection. RESULTS: Hepatitis C virus and GBV-C coinfection was found in 18 of 70 (25.7%) patients. Cases with coinfection were younger and had shorter duration of disease (31.4+/-6.2 vs. 35.3+/-7.3 (p=0.09) and 9.9+/-6.8 vs. 12.9+/-7.7 (p=0.17) years) than those without coinfection. Neither hepatitis C virus genotype distribution and HCV RNA levels nor serum liver function tests, titers of immunoglobulins or autoantibodies differed between the two groups. Histologically, chronic active hepatitis (16.7 vs. 46.4%, p=0.07), fibrosis (8.3% vs. 21.4%, p=0.3), and cirrhosis (0% vs. 8.2%, p=0.31) were less prevalent in coinfected patients. After interferon treatment, 5/6 coinfected and 11/19 patients with hepatitis C virus infection alone had cleared HCV RNA and 4/6 lost GBV-C RNA from serum. The two patients with GBV-C/HCV infection who persistently cleared hepatitis C virus but not GBV-C from serum had normal transaminases during follow-up despite persistence of GBV-C. CONCLUSIONS: Coinfection of chronic hepatitis C patients with GBV-C does not lead to a significant change in clinical presentation, severity of liver disease, hepatitis C viremia, or response to interferon treatment.

Adult↗

Efficacy of ursodeoxycholic acid treatment and endoscopic dilation of major duct stenoses in primary sclerosing cholangitis. An 8-year prospective study.

BACKGROUND/AIMS: Primary sclerosing cholangitis is characterized by progressive fibrotic inflammation and obliteration of intra- and extrahepatic bile ducts. Ursodeoxycholic acid treatment leads to improvement of biochemical parameters of cholestasis and in part also of liver histology. During treatment, obstruction of major ducts may lead to deterioration of liver function, which may be prevented by endoscopic dilation of the stenoses. Controlled trials for evaluation of the beneficial effects of ursodeoxycholic acid treatment and of endoscopic measures in patients with major duct stenoses have become clinically difficult. Estimation of survival probabilities without treatment allows comparison of actuarial survival with the estimated survival probabilities. METHODS/RESULTS: We studied survival in 65 patients with PSC treated with ursodeoxycholic acid (750 mg/day) and by endoscopic measures whenever necessary. Patients with decompensated cirrhosis in whom transplantation was foreseen were excluded. The study was started in May 1987 and the mean follow-up period was 45.0+/-3.5 (mean+/-SEM) months. Liver histology was performed in each of the patients before entry into the study and revealed that 21% were in stage 1, 37% in stage 2, 21% in stage 3 and 20% in stage 4. Of 65 patients, 12 had major duct stenosis at entry and another 11 developed major duct stenosis during ursodeoxycholic acid treatment, which was successfully treated by repeated endoscopic balloon dilations. The actuarial Kaplan-Meier survival probabilities without liver transplantation after treatment with ursodeoxycholic acid and dilation of major duct stenoses were significantly improved compared to the predicted survival rates with p=0.001. CONCLUSIONS: Ursodeoxycholic acid does not prevent major bile duct occlusion. When ursodeoxycholic acid treatment and endoscopic opening of duct stenoses are combined, survival may be significantly improved.

Adolescent↗

Transjugular intrahepatic portosystemic stent shunt versus sclerotherapy plus propranolol for variceal rebleeding.

BACKGROUND & AIMS: In patients with cirrhosis of the liver, after the first variceal bleeding episode, transjugular intrahepatic portosystemic stent shunting (TIPS) and endoscopic sclerotherapy plus propranolol (ES) were compared regarding prevention of variceal rebleeding and mortality. METHODS: Eighty-three patients with cirrhosis of the liver were randomized to undergo TIPS (n = 42) or ES (n = 41). RESULTS: Median observation time was in 1.6 years in the TIPS group and 1.45 years in the ES group. Cumulative rates of rebleeding were 23% in the TIPS group and 57% in the ES group (P = 0.0001). Hepatic encephalopathy was observed in 29% of the patients in the TIPS group and in 13% of those in the ES group (P = 0.041). Cumulative rates of survival were 69% in the TIPS group and 67% in the ES group (P = 0.62). Mortality rates in both groups were positively correlated with a higher Child's classification. CONCLUSIONS: Although TIPS significantly reduced the rate of rebleeding, survival rates were not improved. Because TIPS is associated with an increased risk of encephalopathy and high rates of shunt dysfunction, which requires reintervention, the procedure cannot be recommended for elective treatment after the first variceal bleeding episode, but it is an effective therapy in patients in whom endoscopic sclerotherapy fails to control bleeding.

Adult↗

Establishment of persistent hepatitis C virus infection and replication in vitro.

Hepatitis C virus (HCV) is a major cause of chronic viral hepatitis. Development of anti-viral strategies has been hampered by the lack of efficient cell systems to propagate HCV in vitro. To establish a long-term culture system, we tested human hepatoma (HuH7, HepG2) and porcine non-hepatoma (PK15, STE) cell lines, as well as several culture and infection conditions. As a marker for virus replication, minus-strand HCV RNA in infected cells was detected by an enhanced detection system using nested RT-PCR followed by hybridization analysis. Short-term efficiency of HCV infection (10 days) was slightly increased by addition of polyethylene glycol (PEG) and/or dimethyl sulfoxide (DMSO) to culture media during inoculation of HuH7, PK15 and STE cells, but no augmentation in long-term culture was achieved, suggesting enhanced attachment of HCV to cells rather than more efficient infection. A stabilizing effect on HCV propagation was observed for 50 days in a serum-free medium with stimulation of the low-density lipoprotein (LDL) receptor expression by lovastatin. Using partially serum-free culture conditions, long-term persistence of HCV in cells and release of virions into supernatant was achieved for up to 130 days. Infectivity of released virions in supernatants after long-term culturing (day 30-80) was shown by successful infection of fresh cells. In conclusion, supplementation with PEG, DMSO and lovastatin during inoculation did not enhance virus replication substantially, but continued stimulation of LDL-receptor expression resulted in infections which persisted for over 4 months. These data support the hypothesis of an LDL-receptor mediated uptake of HCV into cells in vitro.

Aged↗