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Biomedical subjects

A Erhardt

Publications and source records attributed to A Erhardt.

At least 19 recordsLinked to original sources
PubMed2006

[Transient elastography for diagnosing liver cirrhosis].

BACKGROUND AND OBJECTIVE: Detection of liver cirrhosis has numerous implications because of the potential sequelae of cirrhosis. Transient elastography (Fibroscan), was evaluated as a novel, non-invasive means of assessing cirrhosis by measuring liver stiffness. METHODS: 147 consecutive patients with different forms of liver disease and histologically determined stages of liver fibrosis were prospectively studied by transient elastography. 48 patients had liver cirrhosis. RESULTS: The number of transient elastographic measurements per patient was 12+/-4 (range 6 - 30). Valid elastography measurements were available for 135 out of 147 patients (92 %). The results of transient elastography correlated positively with the histological score of liver fibrosis (r = 0.8; 95 % CI: 0.72 - 0.85; p < 0.001). Areas under the receiver operating characteristic curve (AUROC) were 0.91 for > or = F3 fibrosis (95 % CI: 0.85 - 0.96) and 0.94 for cirrhosis (95 % CI: 0.90 - 0.98). Using a cut-off value of 13 kPa for detection of liver cirrhosis a sensitivity of 90 %, a specificity of 82 %, a positive predictive value of 71 % and a negative predictive value of 95 % were obtained. CONCLUSIONS: Measuring liver stiffness by transient elastography proved to be an easy method to assess liver cirrhosis. In combination with clinical signs, ultrasound and biochemical markers noninvasive diagnosis of liver cirrhosis will be further improved.

Adolescent↗
PubMed2005

[Current treatment of hepatitis C virus infection].

New strategies have led to better results in the treatment of HCV infection during the last few years. At present the recommended treatment for patients with chronic hepatitis C is a combination of pegylated interferon and ribavirin. The sustained virological response rate of this combination therapy is 42 - 48 % for patients with genotype 1 after a course of 48 weeks and 80 % for patients with genotype 2 or 3 after a course of 24 weeks. New nucleoside analogs may lead to a better tolerance and better outcomes. A new approach is the long term monotherapy with pegylated interferon in order to reduce the progression of fibrosis and the incidence of cirrhotic complications. At present the effectivity of protease inhibitors and of a therapeutic immunisation with the E1 envelope protein of the hepatitis C virus are being examined. Because the optimal treatment strategy for patients with an acute hepatitis C infection is still unclear, these patients should be included in clinical studies.

Acute Disease↗
PubMed2005

Response to interferon alfa is hepatitis B virus genotype dependent: genotype A is more sensitive to interferon than genotype D.

BACKGROUND AND AIMS: Current interferon alfa (IFN) treatment of chronic hepatitis B has limited efficacy. The role of hepatitis B virus (HBV) genotypes for response to IFN was investigated. PATIENTS AND METHODS: HBV genotype was determined by direct sequencing of the HBV X gene in 165 consecutive patients with chronic replicative hepatitis B treated with standard IFN. HBV genotype A or D was found in 144 cases. RESULTS: Sustained response (six months after treatment) to standard IFN therapy was higher in HBV genotype A compared with HBV genotype D infected patients (49% v 26%; p<0.005). Sustained response to IFN was 46% versus 24% (p<0.03) in hepatitis B e antigen (HBeAg) positive hepatitis (n = 99) and 59% versus 29% (p<0.05) in HBeAg negative hepatitis (n = 45) for HBV genotype A compared with HBV genotype D. HBeAg status had no negative impact on IFN response. Multivariate logistic regression identified HBV genotype A and high pretreatment alanine aminotransferase levels (>2 x upper limit of normal) as independent positive predictive parameters of IFN response. CONCLUSIONS: The present study indicates that HBV genotypes A and D are important and independent predictors of IFN responsiveness in chronic hepatitis B. HBV genotype adapted treatment regimens may further improve treatment efficacy in chronic hepatitis B.

Adult↗
PubMed2004

In-medium isovector piN amplitude from low-energy pion scattering.

Differential cross sections for elastic scattering of 21.5 MeV positive and negative pions by Si, Ca, Ni, and Zr have been measured as part of a study of the pion-nucleus potential across the threshold. The "anomalous" repulsion in the s-wave term was observed, as is the case with pionic atoms. The extra repulsion can be accounted for by a chiral-motivated model where the pion decay constant is modified in the medium. Unlike in pionic atoms, the anomaly cannot be removed by merely introducing an empirical on-shell energy dependence.

Journal Article↗
PubMed2004

Repetitive transcranial magnetic stimulation increases the release of dopamine in the nucleus accumbens shell of morphine-sensitized rats during abstinence.

Recent studies in rodents have shown that withdrawal from chronic drug abuse is associated with a significant decrease in dopamine (DA) release in mesolimbic structures, especially in the shell region of the nucleus accumbens. Since the DA system is known to play an important role in reward processes, a withdrawal-associated impairment in mesolimbic DA-mediated transmission could possibly implicate reward deficit and thus enhance vulnerability to drug craving and relapse. We have previously demonstrated that acute repetitive transcranial magnetic stimulation (rTMS) has a modulatory effect on DA release in several areas of the rat brain, including dorsal striatum, hippocampus, and nucleus accumbens shell. In the present study, we investigated the possible use of rTMS as a tool in re-establishing the dysregulated DA secretion observed during withdrawal in morphine-sensitized male Sprague-Dawley rats. Using intracerebral microdialysis, we monitored the effects of acute rTMS (20 Hz) on the intra-accumbal release-patterns of DA in freely moving animals that were subjected to a morphine sensitization scheme for a period of 8 days. We provide first evidence that acute rTMS (20 Hz) is able to increase DA concentration in the shell region of the nucleus accumbens in both control animals and morphine-sensitized rats during abstinence. The DA release in morphine-sensitized rats was significantly higher than in controls. rTMS, therefore, might gain a potential therapeutic role in the treatment of dysphoric and anhedonic states during drug withdrawal in humans.

Animals↗
PubMed2003

Socioepidemiological data on hepatitis delta in a German university clinic--increase in patients from Eastern Europe and the former Soviet Union.

BACKGROUND AND AIMS: The relevance of chronic hepatitis delta results from its high morbidity leading frequently to rapid cirrhosis progression. The aim of the present study was the socioepidemiological characterization of patients with hepatitis delta, in order to identify patients at risk for hepatitis delta. PATIENTS AND METHODS: Clinical parameters of 36 consecutive patients with chronic hepatitis delta, seen between 1989 and 2002 at the University Hospital in Düsseldorf, were evaluated for the present study. Socioepidemiological parameters, available in 31 of these patients who returned a questionnaire, were compared to data of the population of Nordrhein-Westfalen (NRW). RESULTS: Liver cirrhosis was found in 33.3% of patients. There was a mean delay of 3 years between the diagnosis of hepatitis B and D. Patients with delta hepatitis were characterized by lower education, were more frequently unemployed, exhibited less qualified work and had less property compared to the population of NRW. 86.1% of hepatitis delta patients were immigrants to Germany. Before 1995 hepatitis delta infections were mainly seen in patients from Southern Europe (75%), whereas after 1996 predominantly patients from Eastern Europe and the former Soviet Union (53.6%; p < 0.04) contributed to the newly diagnosed cases of hepatitis delta. CONCLUSIONS: The present data underline that hepatitis delta is a severe disease. It seems reasonable to intensify screening for hepatitis delta among patients with low socioeconomic status, especially among immigrants of Eastern Europe and the former Soviet Union.

Adolescent↗
PubMed2002

[Hepatocellular carcinoma: rising incidence of hepatitis C virus-associated cases at a university clinic in Germany].

BACKGROUND AND OBJECTIVE: Hepatocellular carcinoma (HCC) ranks eighth among malignant tumors worldwide. Western countries belong to areas of low HCC prevalence, but incidence of HCC is rising. The aim of the present, retrospective study was to determine changes in the incidence rates and risk factors for HCC in Germany based on the data of a single center. PATIENTS AND METHODS: Epidemiological data of 205 consecutive patients with HCC (163 males, 42 females, mean age 64+/-1 years), admitted to the University clinic Düsseldorf between January 1988 and December 2001, were evaluated. For comparison this time period was divided into two equal intervals (1988 - 1994 and 1995 - 2001). RESULTS: The number of newly diagnosed HCC has more than doubled in the years 1995 - 2001 compared to the years 1988 - 1994. Chronic hepatitis C (HCV), hepatitis B (HBV), and chronic alcohol abuse accounted for almost 80 % of HCC. The number of HCV-associated HCC increased from 31.0 % in the years 1990 - 1995 to 44.6 % (p < 0.04) in the years 1996 - 2001, whereas the proportion of HBV-associated HCC decreased. There were no changes in the Okuda tumor stage, tumor diameter and alpha-fetoprotein levels at the time of HCC diagnosis throughout the years 1988 - 2001. More than 65 % of HCC were non-resectable at the time of HCC diagnosis due to tumor diameter or number of tumor lesions. CONCLUSION: Screening for HCC, possibly rising in its incidence, should be further improved, taking into account that chronic HCV infection is the major risk factor for HCC in Germany.

Adult↗
PubMed2002

Repetitive transcranial magnetic stimulation increases the release of dopamine in the mesolimbic and mesostriatal system.

Repetitive transcranial magnetic stimulation (rTMS) is suggested to be a potentially useful treatment in major depression. In order to optimize rTMS for therapeutic use, it is necessary to understand the neurobiological mechanisms involved, particularly the nature of the neurochemical changes induced. Using intracerebral microdialysis in urethane-anesthetized and conscious adult male Wistar rats, we monitored the effects of acute rTMS (20 Hz) on the intrahippocampal, intraaccumbal and intrastriatal release patterns of dopamine and its metabolites (homovanillic acid, 3,4-dihydroxyphenylacetic acid). The stimulation parameters were adjusted according to the results of accurate MRI-based computer-assisted reconstructions of the current density distributions induced by rTMS in the rat brain, ensuring stimulation of frontal brain regions. In the dorsal hippocampus, the shell of the nucleus accumbens and the dorsal striatum the extracellular concentration of dopamine was significantly elevated in response to rTMS. Taken together, these data provide the first in vivo evidence that acute rTMS of frontal brain regions has a modulatory effect on both the mesolimbic and the mesostriatal dopaminergic systems. This increase in dopaminergic neurotransmission may contribute to the beneficial effects of rTMS in the treatment of affective disorders and Parkinson's disease.

Analysis of Variance↗
PubMed2001

Combination therapy of active HBsAg vaccination and interferon-alpha in interferon-alpha nonresponders with chronic hepatitis B.

Treatment with interferon-alpha leads to cessation of viral replication in 30-40% of patients with chronic hepatitis B. Preliminary data suggest that therapeutic vaccination in patients with chronic HBV infection may be beneficial. The present trial was conducted to assess the efficacy of combination therapy of interferon-alpha with HBsAg vaccination in patients who previously failed to respond to interferon-alpha alone. Eighteen patients positive for HBsAg and HBeAg were included. Mean ALT was 81+/-23 units/liter and 7 (39%) patients had HBV-DNA levels >2000 pg/ml. Patients received 5 million IU interferon-alpha 2b (Intron A) thrice weekly for six months and recombinant HBsAg (Gen H-B-Vax) at the beginning and 4 and 12 weeks after initiation of interferon therapy. No serious side effects were seen during the trial period. Loss of HBeAg was seen in 39% (7/18), HBV DNA was undetectable in 50% (9/18), and ALT was normal in 56% 10/18) of patients six months after completion of therapy. Simultaneous administration of interferon-a and HBsAg vaccination in patients previously not responding to interferon alone appears to be safe, well-tolerated, and it achieved response rates similar to or even higher than interferon in treatment naive patients. This combination therapy seems to offer a new and promising approach for patients with chronic hepatitis B virus infection.

Adult↗
PubMed2000

Mutations of the core promoter and response to interferon treatment in chronic replicative hepatitis B.

In chronic replicative hepatitis B the significance of mutations in the basic core promoter (BCP), core upstream regulatory sequences (CURS) and negative regulatory element (NRE) for response to interferon (IFN) is unknown. A sequence analysis of the NRE, CURS, BCP, and precore region was performed from sera of 96 patients with chronic replicative hepatitis B (64 hepatitis B e antigen [HBeAg]-positive patients and 32 HBeAg-negative patients) treated with alfa-IFN (IFN-alpha). The overall sustained response (SR) rate to IFN was 30% with no significant difference between HBeAg-positive and HBeAg-negative patients. IFN responsiveness correlated to hepatitis B virus (HBV)-DNA levels, hepatitis B surface antigen (HBsAg) levels, the number of mutations in the complete BCP, especially nucleotide (nt) region 1753 to 1766 and mutations at nt 1762 and 1764. In HBeAg-positive hepatitis, SR to IFN was associated with a high number of mutations in the BCP (P <.04) and nucleotide region 1753 to 1766 (P <.015) as well as mutations at nucleotide 1764 (P <.007). In HBeAg-negative hepatitis, SR to IFN correlated with a low number of mutations in the BCP (P <.04) and nucleotide region 1753 to 1766 (P <.02) and a wild-type sequence at nt 1764 (P <.003). Prediction of IFN response was possible on the basis of nt 1764 in 77% of HBeAg-positive patients and 78% of HBeAg-negative patients. IFN response did not correlate with the occurrence of the 1896 mutation, mutations in the CURS or NRE, disease duration, ethnic origin of the patient, alanine transaminase (ALT) levels and HBV genotype. Our data suggest that HBV genome mutations located within the BCP are determinants of a response to IFN therapy.

Adult↗
PubMed2000

Successful treatment of hepatitis B virus associated polyarteritis nodosa with a combination of prednisolone, alpha-interferon and lamivudine.

Therapy of hepatitis B virus (HBV)-associated poly-arteritis nodosa is still evolving. Here we report a successful treatment with a short-term steroid administration in combination with a-interferon and lamivudine and a complete sequence analysis of the HBV genome. A 58-year-old man presented with the symptoms of mononeuritis multiplex associated in time with the onset of highly replicative hepatitis B. Polyarteritis nodosa was confirmed by biopsy. During an initial course with alpha-interferon and prednisolone no clinical improvement or hepatitis B virus seroconversion was observed. After addition of lamivudine to the protocol with fast tapering of prednisolone, HBV DNA fell to undetectable levels within 1 month and liver transaminases normalized. After 6 months of treatment HBeAg seroconversion took place, followed by HBsAg seroconversion 2 months later. Clinical symptoms of polyarteritis improved. No relapse of polyarteritis or hepatitis B was seen during the follow up of 9 months. Complete sequence analysis of the HBV genome revealed 6 nucleotide mutations but none in a relevant antigenic epitope. The present protocol of short-term prednisolone administration combined with alpha-interferon and lamivudine was effective for the treatment of HBV-related polyarteritis nodosa and may be a promising new therapeutic approach.

Antiviral Agents↗
PubMed2000

[New developments in therapy of chronic hepatitis B. When are nucleoside analogs indicated?].

Nucleoside analogues are promising agents for the treatment of chronic hepatitis B infection (HBV-DNA-positive by hybridization assay). The drug being studied most intensively is Lamivudine (Zeffix) which has recently been approved in Germany. When given orally once daily (100 mg) Lamivudine is well-tolerated and suppresses HBV-DNA to undetectable levels in the majority of patients. Since relapse is frequent when medication is stopped long-term treatment (at least until seroconversion of HBeAg) is warranted. Indications for lamivudine monotherapy are patients with chronic hepatitis B in which interferon (IFN) is contraindicated or patients who did not respond to a previous course of interferon. Further indications are the HBV-DNA-positive cirrhosis prior to liver transplantation (OLT) and the HBV-reinfection after OLT. The main problem of long-term monotherapy with lamivudine is viral resistance. The clinical impact of the resistant mutants is often not clear. Withdrawal or even continuation of the medication may be acceptable approaches. Other nucleoside analogues like Entecavir or Adefovir are currently being tested in clinical studies. Famciclovir was investigated preferably in patients with decompensated liver disease or HBV-reinfection after OLT. Because of conflicting results the drug should only be used under study conditions. In IFN-naive patients with chronic hepatitis B (and compensated liver disease) alpha-interferon is still the first-line therapy. With a standard course of interferon 30-40% of the patients become seronegative for HBeAg as compared with 16-17% when treated with lamivudine for twelve months. Combination of lamivudine and interferon is not more effective than IFN alone. In the future combined antiviral treatment is likely to replace monotherapy.

Adenine↗
PubMed2000

[Antiviral therapy of hepatitis C].

Hepatitis C is one of the world's leading infectious diseases. The interferon-ribavirin combination therapy is the new standard for the treatment of hepatitis C in naive and relapse patients. Virological sustained response rates can be more than doubled by the IFN-ribavirin combination therapy compared to IFN-monotherapy and treatment duration can be reduced to six months in many cases. The IFN-ribavirin combination therapy has a high relative benefit in patients with unfavorable predictive parameters like high viral load, HCV genotype-1 infection and compensated liver cirrhosis. Anemia is the most important side effect of the guanosin analogue ribavirin. There are no official therapeutic recommendations for non-responder patients at present. These patients should be treated within controlled clinical trials. Monotherapy with PEG(pegylated)-interferons and combination therapies with PEG-interferons and ribavirin are the most promising future therapeutic options.

Antiviral Agents↗