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Biomedical subjects

L Theilmann

Publications and source records attributed to L Theilmann.

At least 127 records · Page 7Linked to original sources
PubMed1988

HBV DNA and other hepatitis B virus markers in sera from long-term hemodialysis and kidney transplant patients.

Sera from 191 long-term hemodialysis patients and from 115 renal transplant patients were studied for the presence of HBsAg and other HBV markers. In 19.1% of the hemodialysis patients and 28.7% of the transplant patients, the sera were positive for HBeAg.HBV DNA in sera was detected by molecular hybridization. HBV DNA was present in the sera of 15 out of 16 hemodialysis patients positive for HBeAg, and in one hemodialysis patient positive for anti-HBe. All renal transplant patients positive for HBeAg were also positive for HBV DNA. Twelve transplant patients were positive for HBV DNA, but negative for both HBeAg and anti-HBe. Determination of HBV DNA was the most sensitive marker of infectivity in patients with end-stage renal disease, and in renal transplant patients.

Adult↗
PubMed1988

Detection of antibodies against pre-S1 proteins in sera of patients with hepatitis B virus infection by ELISA using a pre-S fusion protein expressed in E. coli.

To evaluate the importance of antibodies directed against pre-S1 proteins (anti-pre-S1) of hepatitis B virus (HBV) in human sera, an enzyme-linked immunosorbent assay (ELISA) for their detection in human sera was established, using a bacterially synthesized pre-S1 fusion protein. Using this ELISA, it was found that anti-pre-S1 was present in sera from 10 of 11 patients with acute HBV infection who recovered completely, but only present in 1 of 8 patients where the infection was prolonged. In chronic HBV carriers anti-pre-S1 was present in only 3 out of 8 patients and titers were low. In addition, in 5 out of 17 individuals who had recovered from previous HBV infection, anti-pre-S1 was also detected. Individuals immunized with recombinant HBsAg-vaccine and healthy controls were all negative for anti-pre-S1. It is suggested that presence of anti-pre-S1 in sera of patients with acute HBV infection correlates with rapid recovery.

Enzyme-Linked Immunosorbent Assay↗
PubMed1988

Detection of antibodies to proteins encoded by the X-region of hepatitis B virus (HBV) in sera of patients with chronic HBV infection: correlation with other HBV markers.

The genome of hepatitis B virus (HBV) contains a fourth open reading frame (ORF), designated X-region. It was the aim of our study to test sera of patients with chronic HBV infection for the presence of antibodies reactive with a 17 kd gene product of the X-ORF. For this purpose, a 35S-X-ORF-encoded protein, synthesized in vitro, was applied as antigen for the detection of antibodies to HBx proteins in sera of 86 individuals. Antibodies reacting with a gene product of the X-ORF were present in 10 out of 24 HBsAg-positive patients with hepatocellular carcinoma (PLC) or liver cirrhosis and in one out of 8 HBsAg-carriers. In addition, the antibodies could also be detected in 6 out of 35 sera from patients with PLC or cirrhosis negative for HBsAg but positive for anti-HBc and anti-HBs. Antibodies to a gene product of the X-ORF can be detected in sera of patients with chronic HBV-related liver disease, independently of HBsAg and the HBeAg/anti-HBe system.

Genes, Viral↗
PubMed1987

Synthesis of the X-protein of hepatitis B virus in vitro and detection of anti-X antibodies in human sera.

A protein of 154 amino acids, predicted to be encoded by the X-open reading frame of the hepatitis B virus (HBV) genome, was synthesized in an in vitro translation system from SP6 transcripts containing the X-coding sequence. As characterized by SDS-PAGE and immunoprecipitation this X-protein possesses the expected molecular weight of 17 kDa and reacts specifically with rabbit antisera directed against a fusion protein from Escherichia coli that contained 145 of the 154 amino acids from the X-sequence. The X-protein, radiolabeled with [35S]methionine, provided a sensitive and specific antigen to screen for anti-X antibodies in sera from HBV patients. Positive signals were obtained preferentially in subjects suffering from HBV-induced liver cirrhosis or primary hepatocellular carcinoma (PHC), i.e., individuals that had been exposed for an extended time period to HBV gene products. Carefully controlled experiments failed to reveal the presence of X-related proteins specific to liver specimens from HBV patients.

Amino Acid Sequence↗
PubMed1987

Detection of antibodies against pre-S1 proteins in sera of patients with hepatitis B virus (HBV) infection.

Pre-S1 (large S) proteins are components of the envelope of HBV. The presence of pre-S1 proteins is correlated with viral replication. To test sera of patients with HBV infection for the presence of antibodies against pre-S1 proteins (anti-pre-S1), an E. coli extract containing a pre-S fusion protein covering the greater part of the pre-S1 region was subjected to Western blotting and probed with sera of patients. Anti-pre-S1 was present in the sera of all 4 patients with acute self-limited HBV infection and in the sera of 3 patients with a fulminant course. The antibodies could not be detected in the sera of 6 patients with acute HBV infection entering chronicity, in the sera from 10 HBsAg carriers or in the sera of 25 patients with chronic liver disease, positive for HBsAg and antibodies to hepatitis Delta virus. In an additional study, anti-pre-S1 could not be found in 11 sera from 12 patients with previous HBV infection, positive for anti-HBs and anti-HBc. Antibodies to pre-S1 proteins appear at the early stage of acute resolving HBV infection and seem to play a role in the elimination of the virus. The antibodies are absent in the sera of patients with acute HBV infection entering a chronic course and in the sera of chronic HBsAg-carriers.

Acute Disease↗
PubMed1987

Pre-S1 proteins in sera of patients positive for HBsAg and antibodies to hepatitis delta virus.

Infection with the hepatitis Delta virus results in a reduction in hepatitis B virus replication. To study the question as to whether expression of large surface (pre-S1) protein is changed in patients with previous and chronic hepatitis Delta virus infection, sera of 25 HBsAg- and anti-HD-positive patients were analyzed by the Western blot technique using an antibody directed against a pre-S1 fusion protein. Pre-S1 proteins were present only in 3 of the 25 sera. This finding suggests that the expression of pre-S1 proteins and HBsAg is regulated independently, and that pre-S1 proteins are not necessarily required for the envelope of hepatitis Delta virus.

Antibodies, Viral↗
PubMed1987

Rapid procedure for the detection of hepatitis delta virus RNA in sera of HBsAg-positive and anti-delta-positive patients.

A synthetic oligonucleotide duplex of 78 bp corresponding to part of the recently published RNA sequence of hepatitis Delta virus (HDV) was cloned into the plasmid pSBO1 and used for the detection of HDV RNA in sera of patients with chronic HDV infection by molecular hybridization. RNA containing the 78 bp sequence was synthesized in vitro and used as a positive control. For this purpose, a fragment containing the cloned oligonucleotide was transferred into the plasmid pSPT 18. HDV RNA was present in 5 out of 32 hepatitis B surface antigen (HBsAg)- and anti-HD-positive patients. It was neither found in the sera of 19 HBsAg-positive, anti-HD-negative patients, nor in the sera of 26 patients with chronic liver disease negative for both HBsAg and anti-HD. The method appears to be suitable for the detection of viruses of which either only parts of the genome or the entire sequence is known.

Antibodies, Viral↗
PubMed1986

Selective inhibition of long-chain fatty acid uptake in short-term cultured rat hepatocytes by an antibody to the rat liver plasma membrane fatty acid-binding protein.

Uptake of long-chain fatty acids by short-term cultured hepatocytes was studied. Rat hepatocytes, which were cultured for 16 h on plastic dishes (3.6 X 10(6) cells/dish), were incubated with [3H]oleate in the presence of various concentrations of bovine serum albumin as a function of the concentration of unbound [3H]oleate in the medium. At 37 degrees C initial uptake velocity (V0) was saturable (Km = 9 X 10(-8) M; Vmax = 835 pmol/min per mg protein). V0 was temperature dependent with an optimum at 37 degrees C and markedly reduced at 4 degrees C and 70 degrees C. To evaluate the biologic significance of a previously isolated rat liver plasma membrane fatty acid-binding protein as putative carrier protein in the hepatocellular uptake of fatty acids, cultured hepatocytes were treated with a monospecific rabbit antibody (IgG-fraction) to this membrane protein or the IgG-fraction of the pre-immune serum as controls. Uptake kinetics of [3H]oleate in antibody pretreated short-term cultured hepatocytes revealed a depression of Vmax by 70%, while Km was only reduced by 16% compared to controls, indicating a predominant non-competitive type of inhibition. V0 of a variety of long-chain fatty acids (oleic acid, arachidonic acid, palmitic acid, stearic acid) was reduced by 56-69%, while V0 of [35S]sulfobromophthalein, [3H]cholic acid and [14C]taurocholic acid remained unaltered. These data support the concept that in the system of cultured hepatocytes, uptake of long-chain fatty acids is mediated by the rat liver plasma membrane fatty acid-binding protein.

Animals↗
PubMed1986

Putative reverse transcriptase intermediates of human hepatitis B virus in primary liver carcinomas.

Nucleocapsid-pol fusion proteins have been detected by serological screening hepatocellular carcinoma tissues that contain hepatitis B virus (HBV) DNA. The existence of these fusion proteins suggests that HBV may synthesize its reverse transcriptase in a fashion analogous to the way that retroviruses synthesize and process a precursor. The accumulation of HBV reverse transcriptase intermediates in tumorous tissues and not in other tissues may be related to the absence of viral core particles and possibly contributes to tumor development.

Animals↗
PubMed1986

Characterization of large surface proteins of hepatitis B virus by antibodies to preS-S encoded amino acids.

The major surface protein of HBV, the 226-amino-acid HBsAg, is encoded in the 3' proximal segment of the preS-S gene of 389 codons. To identify gene products from the 5' proximal preS sequence, DNA fragments from the preS region were expressed in Escherichia coli as fusion proteins. Antisera prepared against these fusions were used to screen serum proteins of HBV-infected individuals, and found to react specifically with the two large HBV surface proteins of 39 and 42 kDa. The presence of these proteins could be correlated with acute HBV infection. Analysis by Western blotting using the preS sequence-specific antisera and HBV particles separated into spheres, filaments, and Dane particles confirmed that these proteins were associated with the native virus. Dane particles containing active DNA polymerase could be immune precipitated by the preS-specific antibodies, showing that the preS-coded part of these surface proteins is located on the surface of the virion.

DNA, Viral↗
PubMed1986

Epidemiological studies on the prevalence of hepatitis Delta virus infections in the Federal Republic of Germany.

This study evaluated the prevalence of hepatitis Delta virus (HDV) infections in various groups of HBsAg carriers including drug addicts and patients with hemophilia in the Federal Republic of Germany. HDV was found only occasionally (less than 1%) in individuals found HBsAg positive during an examination as potential blood donors or in hemodialysis patients, but in 3% in patients with chronic hepatitis and up to 50% in drug addicts and hemophilia patients. These findings are in agreement with data reported from other European countries. Presence of antibodies to HDV in two hemodialysis patients indicates the presence of HDV in this group and screening for HDV infections in hemodialysis units is indicated to prevent outbreaks of this disease in HBsAg-positive patients with possibly serious consequences.

Blood Donors↗
PubMed1986

Pre-S1 antigens and antibodies early in the course of acute hepatitis B virus infection.

The presence of the two "large" surface proteins of hepatitis B virus (HBV), P39 and GP42 of pre-S1-hepatitis B surface antigen, was assayed in the serum of an experimentally infected chimpanzee by using antibodies to a pre-S1-specific fusion protein synthesized in Escherichia coli. The immune response to pre-S1-hepatitis B surface antigen was monitored by using the pre-S1 fusion protein as an antigen. pre-S1 proteins were detected in the serum early in the course of infection and prevailed as long as hepatitis B surface antigen did, together with hepatitis B e antigen and viral DNA. Thus, the pre-S1 antigen can be considered a novel diagnostic marker for acute HBV infection. Antibodies to pre-S1, both immunoglobulin M and G classes, were also detected early in infection, shortly after the appearance of the pre-S1 antigen, suggesting its strong immunogenicity in vivo. The anti-pre-S1 antibodies therefore also represent an early serological marker for acute HBV infection and, owing to their early appearance and persistence, may play a role in the neutralization of the virus.

Acute Disease↗
PubMed1986

Prevalence of the hepatitis delta virus in Rumania.

Epidemiological data obtained to date show that the delta agent is spread all over the world. In Rumania hepatitis B virus infection is widespread and is associated with a high incidence of chronic liver disease. To determine the prevalence of delta infection, sera from 373 patients with chronic liver disease were tested for HBV markers; 228 were HBsAg positive. Anti-HD was present in 190 sera (83.33%), which reveals a very high incidence and shows a higher frequency of the active forms of the disease. However, in contrast to other studies, we found a high incidence of HDV infection in chronic persistent hepatitis and hepatocellular carcinoma.

Hepatitis B Surface Antigens↗
PubMed1985

[Frequency of delta infections in Heidelberg].

The frequency of delta infection was studied in sera of 203 patients with acute hepatitis B, further 461 hepatitis B virus surface antigen-(HBsAg)-positive patients and 117 HBsAg-negative controls by determination of anti-delta by a competitive enzyme immunoassay. Sera have been collected since 1974. None of the sera of acute hepatitis B was anti-delta-positive whereas seven of the HBsAg-positive carriers were anti-delta-positive. Two of the anti-delta-positive patients had chronic hepatitis, four had liver cirrhosis. One of the anti-delta-positive patients with liver cirrhosis died of liver failure. Risk factors included Italian origin and parenteral routes of infection. All sera of 19 relatives of three anti-delta-positive index cases remained anti-delta-negative.

Antibodies, Viral↗