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Biomedical subjects

W Jilg

Publications and source records attributed to W Jilg.

At least 91 records · Page 5Linked to original sources
PubMed1989

Detection of hepatitis B virus in serum using amplification of viral DNA by means of the polymerase chain reaction.

A new assay was developed for the detection of hepatitis B virus (HBV) in human serum using amplification of a short viral DNA sequence by means of the polymerase chain reaction. As little as 0.4 fg viral DNA, corresponding to about 130 genome equivalents, per ml serum could be detected after the amplification procedure. This assay detected viral DNA in a number of patients with proven or suspected chronic HBV infection who were all negative for HBV DNA in the conventional hybridisation assay. We found HBV DNA in all of six HBeAg-positive and in three of eight HBeAg-negative HBsAg carriers, as well as in all of 11 patients with chronic liver disease with antibodies against the HBV core antigen (anti-HBc) as the sole marker for HBV infection, and in three of five apparently healthy individuals showing only anti HBc. Thus, this method is an important improvement for the diagnosis of persistent HBV infections, especially in patients where a definitive serological diagnosis is not possible.

Antibodies, Viral↗
PubMed1989

Modification of HLA expression as a possible factor in the pathogenesis of Burkitt's lymphoma.

Our data show that: Most BL cells express significantly less HLA class I and II than the corresponding LCLs. Lymphoblastoid cell lines have a much higher HLA class I and II density than normal peripheral blood B cells. There are qualitative differences in class I and II expression in most BL/LCL pairs. These qualitative differences are not caused by EBV infection. They might be due to a selective downregulation of HLA specifities by c-myc activation. We conclude that these modifications of HLA expression may well play a role in the reduced specific immune recognition of Burkitt's lymphoma cells.

Burkitt Lymphoma↗
PubMed1989

Vaccination against hepatitis B: comparison of three different vaccination schedules.

Three different hepatitis B vaccination schedules employing injections at months 0, 1, 2, and 12, at months 0, 1, and 6, or at months 0, 1, and 12 were compared in 89 healthy young adults. Concentrations of antibodies to hepatitis B surface antigen (anti-HBs) after the third injection were dependent on the interval between the second and the third dose; geometric mean titers (GMTs) in the three groups were 53 IU/l, 5,846 IU/l, and 19,912 IU/l, respectively, when the third dose was given at month 2, 6, or 12. Whereas the anti-HBs responses to the third dose at month 6 or 12 were typical booster reactions, the kinetics after a third dose given at month 2 resembled those after only two doses but on a significantly higher level. A fourth dose given at month 12 to the individuals vaccinated at months 0, 1, and 2 led to a prompt anti-HBs response similar in height to the response in those vaccinated at months 0, 1, and 12. Thus, for achieving a high anti-HBs concentration guaranteeing its long-lasting persistence, vaccination at months 0, 1, and 12 seems to be preferable to vaccination at months 0, 1, and 6. For individuals at high risk of hepatitis B infection, vaccination at months 0, 1, 2, and 12 might be considered for obtaining an optimal early seroconversion as well as long-term protection.

Adult↗
PubMed1988

Immune response to hepatitis B revaccination.

Two hundred and twelve individuals who failed to respond or responded poorly to hepatitis B vaccination or whose anti-HBs levels had dropped below 10 IU/L at follow-up were revaccinated. Only 18% of initial nonresponders, but 96% of those who responded initially, developed anti-HBs above 10 IU/L after revaccination. In 85% of vaccinees, anti-HBs titres after a fourth immunization were significantly higher than after completion of the first full immunization course, and despite a steeper decline of antibody levels after revaccination, anti-HBs seemed to persist better than after the initial course of three inoculations. All individuals who responded initially and in whom anti-HBs had become undetectable developed antibodies. Response to booster doses was seen after three to five days, and a fifth inoculation given to 23 individuals induced even better responses.

Adult↗
PubMed1988

Persistence of specific antibodies after hepatitis B vaccination.

Antibody levels to hepatitis B surface antigen (anti-HBs) in healthy adults vaccinated with three doses of plasma-derived hepatitis B vaccine, containing 20, 10 or 5 micrograms of antigen, were followed for 4-6 years. After vaccination, 1034 of 1076 individuals had developed anti-HBs and 1016 had antibody concentrations above 10 IU/l. 681 of all initial responders could be tested after 1 year, 520 after 2, 380 after 3 and 213 after 4 years. 72 and 39 individuals, respectively, of the 185 earliest vaccinated volunteers were available for retesting after 5 and 6 years. Four years after the first vaccination, anti-HBs levels in 34% had dropped below 10 IU/l. The persistence of anti-HBs above this value depended on the peak antibody response after the third vaccination. Whereas all vaccinees tested with peak anti-HBs levels above 10,000 IU/l still had levels above 10 IU/l after 6 years, no-one with initial values between 10 and 100 IU/l maintained antibody concentrations above 10 IU/l for longer than 4 years. The rate of decrease in anti-HBs was independent of the peak anti-HBs value, the vaccine dose, and the age and sex of the vaccinees.

Adult↗
PubMed1986

Expression of the Epstein-Barr virus major membrane proteins in Chinese hamster ovary cells.

The gene of the major membrane antigen (gp250/350) of the Epstein-Barr virus (EBV) was isolated and inserted under the control of the SV40 early promoter into a eukaryotic expression vector, which allows selection for dhfr+ phenotype. Following transfection with this vector, Chinese hamster ovary cells express on their surfaces proteins immunologically similar to the major EBV membrane antigen. The transcript encoding gp250/350 is processed by partial splicing similarly but more efficiency than in B95-8 cells from which the DNA originates.

Animals↗
PubMed1986

Expression of the Epstein-Barr virus 138-kDa early protein in Escherichia coli for the use as antigen in diagnostic tests.

We have attempted to produce the 138-kDa early protein (ep 138) of Epstein-Barr virus (EBV) in Escherichia coli. This protein was found, by immunoprecipitation, to be a clinically relevant antigen, especially for the determination of the IgA-titer in patients with nasopharyngeal carcinoma (NPC). Since the expression of the entire ep 138 coding region was unsuccessful, we synthesized only the antigenic parts of this protein. Potential antigenic sites were predicted from the amino acid sequence by combining values for hydrophilicity with calculated estimates of the secondary structure. The two predicted fragments were found to be antigenic, but only one of them was stably expressed in E. coli as a non-fusion protein. This stable protein fragment was, in turn, able to stabilize the second antigenic fragment forming an autologous fusion protein, consisting exclusively of EBV-derived sequences. The resulting product reacts particularly well with IgA antibodies of NPC patients indicating its diagnostic value for NPC.

Antigens, Viral↗
PubMed1986

Results of immunisation with a recombinant yeast-derived hepatitis B vaccine.

Recombinant hepatitis B virus vaccine was used to immunise groups of healthy adults, dialysis patients, staff of dialysis units and newborn infants. Seroconversion rates, mean titres and decay curves were similar to those induced by plasma-derived vaccine, including somewhat lower responses by dialysis patients. Response to recombinant vaccine was slightly delayed compared to plasma-derived vaccine, but otherwise the recombinant vaccine promises to be at least as effective as plasma-derived vaccine.

Adolescent↗
PubMed1986

Immunogenicity of recombinant hepatitis B vaccine in dialysis patients.

Eighty-eight dialysis patients were vaccinated with recombinant hepatitis B vaccine prepared in yeast. Fourty-nine patients were immunized 3 times (months 0, 1, 6) intragluteally with 40 micrograms hepatitis B surface antigen (HBsAg) per dose. Only 32 of them (65.3%) showed anti-HBs concentrations above 10 IU/l with a geometric mean titer (GMT) of 180.7 IU/l after 3 vaccinations, whereas all of the 16 healthy controls, vaccinated 3 times with a 10-micrograms dose of the same vaccine batch, had specific antibodies higher than 10 IU/l (GMT 897.4 IU/l). Responses of patients were slightly higher than those of dialysis patients vaccinated in an earlier study with plasma-derived vaccine according to the same schedule. Results in 20 patients immunized 6 times intragluteally with 40 micrograms HBsAg/dose in monthly intervals were not better (at month 7, 65% showed anti-HBs concentrations greater than 10 IU/l; GMT = 126.6 IU/l), and 19 patients receiving 6 times 20 micrograms HBsAg monthly showed significantly lower responses (anti-HBs greater than 10 IU/l in 42% of vaccinees, GMT = 89.5 IU/l). The vaccine was tolerated well; side-effects were slight, and no serious adverse reactions were observed. In conclusion, recombinant hepatitis B vaccine is comparable to plasma-derived vaccine also in the case of dialysis patients; a 6-dose schedule does not seem to have much advantage compared to the conventional 3-dose regimen.

Adult↗
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↗
PubMed1985

[Persistence of antibodies against hepatitis B surface antigens after vaccination against hepatitis B].

In 195 patients vaccinated against hepatitis B the course of anti-HBs concentration was followed over 4 years. Persistence of anti-HBs proved to be dependent on the level of anti-HBs concentration after basal immunization: in 14 subjects with a maximal anti-HBs level between 10 and 100 IU/l the level had dropped to less than 10 IU/l (considered to be the lowest prophylactic concentration), while 7 were anti-HBs negative. Of those who had 101-1000 IU/l after initial immunization 49% had anti-HBs levels under 10 IU/l after 4 years, while 18% were negative. Among subjects with concentrations 1001-10 000 IU/l after the third immunization only 7% had values below 10 IU/l after 4 years, 4.2% were negative. All those who, after the third immunization, had had anti-HBs levels above 10 000 IU/l, 4 years later still had anti-HBs levels of more than 100 IU/l (mean 581 IU/l). Quantitative anti-HBs determination after triple vaccination against hepatitis B thus makes it possible to predict the duration of protection and to determine the timing of re-vaccination.

Adult↗
PubMed1985

Immune responses to late booster doses of hepatitis B vaccine.

Nineteen healthy young adults were vaccinated with plasma-derived hepatitis B vaccine at months 0, 1, and 12, and their immune responses were compared to those of a similar group of 20 vaccinees immunized at months 0, 1, and 6. Late booster injections at 12 months produced nearly fivefold higher geometric mean anti-HBs levels than those of the control group. The higher anti-HBs values may lead to longer persistence of anti-HBs and thus to longer protection against hepatitis B.

Adult↗
PubMed1985

Detection of hepatitis B virus DNA in serum by a rapid filtration-hybridization assay.

A simple method for detecting hepatitis B virus DNA (HBV DNA) in serum using a filtration step for spotting sera on nitrocellulose paper followed by molecular hybridization is described. This method is rapid, sensitive, requires very small quantities of serum, and can be used for simultaneous testing of up to 96 samples in one filter apparatus. The sera tested for HBV DNA were also assayed for serological markers of HBV infection and comparison of data shows that on average 67% (30 of 45) of HBsAg- and HbeAg-positive sera contain HBV DNA, whereas 13% of HBsAg- and anti-HBe-positive sera contain HBV DNA. In general, there was a statistically significant correlation between the concentration of HBsAg in the serum and the presence or absence of HBV DNA. These results indicate that molecular hybridization is a valuable assay in addition to serological markers for identifying the possible infectivity of sera, and the simple and rapid method reported here makes the use of such hybridization technique easier.

DNA, Viral↗