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Biomedical subjects

B Flehmig

Publications and source records attributed to B Flehmig.

At least 73 records · Page 4Linked to original sources
PubMed1984

Persistent infection of human fibroblasts by hepatitis A virus.

Infection of human embryo fibroblasts with hepatitis A virus (HAV), a picornavirus, leads to an inapparent, persistent infection; cultures can be passed serially with consistent recovery of the virus in the supernatant. All of the cells of a HAV carrier culture are infected and proliferate. Subcultivation under HAV-immune serum cannot achieve a cure or even a reduction in the number of infected cells in HAV carrier cultures. No interferon activity can be detected during HAV infection and persistence. Addition of exogenous interferon eliminates HAV infection in vitro. Persistence of HAV in vitro appears to contradict the clinical course of HAV infection in vivo. The system presented offers the possibility of evaluating the role of immunological injury of HAV-infected cells, an injury which may lead to damage of these cells and to elimination of HAV during an HAV infection in vivo.

Carrier State↗
PubMed1983

Proteases of Pseudomonas aeruginosa in patients with cystic fibrosis.

Radioimmunoassays were used to determine titers of antibody to alkaline protease (AP) and elastase (Ela) produced by Pseudomonas aeruginosa in sera and bronchial secretions, in vitro production of AP and Ela by P. aeruginosa isolates, and occurrence of these enzymes in bronchial secretions from patients with cystic fibrosis. Titers of serum antibodies to AP ranging from 1:10 to 1:545 and to Ela ranging from 1:10 to 1:725 were found in 83%-88% of patients with cystic fibrosis and chronic lung infections due to P. aeruginosa. Antibody titers in liquified bronchial secretions were approximately 10% of the serum titers. Thirty-one (93%) of 34 isolates produced both proteases in vitro in comparable amounts (concentration of protease in culture supernatant: AP, 0.01-480 micrograms/ml; Ela, 0.02-490 micrograms/ml). AP and Ela were detected in vivo when antibodies to the enzymes were absent. The results suggest that specific immune responses in patients with cystic fibrosis neutralize proteases of P. aeruginosa.

Adolescent↗
PubMed1983

Is the use of the term 'posttransfusion hepatitis type B' in its conventional sense still justifiable?

We have investigated 8 cases of clinically manifest hepatitis type B said to be posttransfusion hepatitis that have become known in the years 1978-1981. Paired samples of serum from all 54 blood donors implicated have been drawn at the time of the donation in question as well as a few months later. Only 1 donor, negative for HBsAg but positive with high titer for anti-HBc, could have been a possible source of infection. There is strong evidence that this person is a chronic low level carrier. In the case of 2 other patients transmission of hepatitis by clotting factors from pooled plasma cannot be denied. Regarding the remaining 5 cases, there is no hint whatsoever for a causal connection between blood transfusion and hepatitis type B.

Hepatitis B↗
PubMed1982

[Results from the hepatitis A-virus diagnostic of the hygiene-institut in Tübingen].

The age-specific and seasonal distribution of serologically confirmed hepatitis A-cases in the area of Tübingen in southern Germany is reported. During 1978-1980 most of the hepatitis A-cases diagnosed by high anti-HAV-IgM titers occurred from September to December. The age distribution of patients with German names showed two age-related peaks, the first one in young children 5-10 years of age and a second one in young adults between 20-30 years. In patients with names suggesting mediterranean origin there is only one age-related peak in early childhood. A comparison of German children with children of foreign parents born and grown up in Germany shows an earlier infection and higher infection rate in the latter. The parents of these children are almost exclusively immigrant workers from mediterranean countries. Visits of the children to the home countries of their parents in which hepatitis A is very common are supposed to be of prime importance for the high prevalence and early occurrence of hepatitis A in this group.

Adolescent↗
PubMed1981

Interferon-neutralizing antibodies in a patient treated with human fibroblast interferon.

During recent years clinical trials have shown that human leukocyte interferon (HuIFN-alpha) may be useful in the treatment of cancer, but very little has been done concerning the possible use of human fibroblast interferon (HuIFN-beta). Treuner et al. recently reported the successful treatment of a nasopharyngeal carcinoma with HuIFN-beta: in the course of IFN-therapy a HuIFN-beta neutralizing activity appeared in the serum of this patient. We report here that such activity is due to IgG antibodies--this study is the first to present evidence for antigenicity of IFN in a homologous system.

Antibody Formation↗
PubMed1981

Hepatitis A virus in cell culture. II. Growth characteristics of hepatitis A virus in Frhk-4/R cells.

The propagation of hepatitis A virus (HAV) is shown in a rapidly growing fetal rhesus monkey kidney cell line (Frhk-4/R). In the course of ten passages through Frhk-4/R cells the HAV, which was released in the supernatants of the cell cultures, was adapted to these cells. In the tenth passage 6 days after infection, it was possible to detect low amounts of HAV in the supernatants by radioimmunoassay (RIA). With indirect immunofluorescence 3 days after infection, a specific granular fluorescence was demonstrated in the cytoplasm of cells infected with HAV from the tenth passage. A persistent infection of Frhk-4/R cells appeared with a main peak at a density of 1.32 g/cm(3) in CsCl density gradients. In the 1.32 g/cm(3) fractions, typical HAV particles are shown by electron microscopy. Furthermore the HAV produced in Frhk-4/R cells is shown to be a useful antigen for diagnostic tests.

Animals↗
PubMed1981

Hepatitis A virus in cell culture. III. Propagation of hepatitis A virus in human embryo kidney cells and human embryo fibroblast strains.

The propagation and adaptation of hepatitis A virus (HAV) in human embryo kidney cells (HKC) is shown. The growth curve of HAV in the first passage through HKC is compared to the growth curve in the tenth passage through HKC. It is shown that in the course of 18 passages through HKC, HAV adapted to these cells causing the virus to grow much more rapidly. The cell-bound HAV is compared to the HAV released in the cell-culture supernatant during the ninth passage through HKC. The HAV from the tenth passage through HKC is shown to be able to replicate also in a human embryo fibroblast strain (HFS). Furthermore, adaptation of the HAV to HFS is demonstrated.

Adaptation, Physiological↗
PubMed1980

[Epidemiology and clinical aspects of non-A, non-B hepatitis (author's transl)].

Among 288 patients with acute viral hepatitis investigated between 1970 and 1976 29 (10%) had non-A, non-B hepatitis. In 9 of these 29 patients posttransfusion hepatitis was proven, the remaining 20 patients had sporadic infections. The incubation period of posttransfusion hepatitis was 2--8 weeks in 7 patients and 12 and 16 weeks in the two other patients. Transaminases changed monophasically in 22 patients, bi- or multiphasic in 7. The disease took a subicteric course in a quarter of all cases. Out of the 29 patients 17 were followed up for 2 to 7 years, one or more recurrence occurred in 9 patients, usually within the first two years after onset of the disease. Five of these 9 patients had a biphasic rise of transaminases during the acute stage. The almost complete absence of autoantibodies in the course of the acute phase might be evidence of increased suppressor cell activity favouring a chronic course. Non-organ-specific autoantibodies were only rarely observed and were completely absent in patients with posttransfusion hepatitis.

Acute Disease↗
PubMed1980

Hepatitis A-virus in cell culture: I. propagation of different hepatitis A-virus isolates in a fetal rhesus monkey kidney cell line (Frhk-4).

A fetal rhesus monkey kidney cell line (Frhk-4) was infected with different hepatitis A-virus (HAV) isolates GBG, GBM, GJA. The time-dependent absorption of the HAV isolates of Fhrk-4 cells was measured. Replication of all three isolates in these cells could be demonstrated intracellularly 8--10 weeks after infection, and release of HAV into the supernatant some 10--15 weeks after infection could be shown. The specificity of the virus determination by RIA from supernatants of HAV-infected cells from passages 1, 2, and 3 in Frhk-4 cells was shown with sera that were collected from a chimpanzee infected with MS-1 both before infection as well as during convalescence. These results were subsequently compared with sera collected from human patients before the onset of hepatitis as well as during convalescence. With immunofluorescence microscopy a cytoplasmic fluorescence could be shown in HAV-infected Frhk-4 cells and finally the release of 27 nm HAV particles into the supernatant of HAV-infected Frhk-4 cells could be demonstrated by immune electron microscopy.

Animals↗
PubMed1980

Detection of IgM antibodies to cytomegalovirus (CMV) using an enzyme-labelled antigen (ELA).

We have applied a peroxidase enzyme-labelled antigen (ELA) for the detection of IgM antibodies to cytomegalovirus: microtitre plates were coated with anti-IgM immunoglobulin. The IgM fraction of human serum was selectively bound to the precoated plates and the virus-specific IgM antibody was then detected by the enzyme-labelled antigen. A very efficient technique for the labelling of virus antigen is described. The IgM antibody was detected simply and specifically, Rheumatoid factor IgM did not interfere with this test.

Antibodies, Viral↗
PubMed1979

A solid-phase radioimmunoassay for detection of IgM antibodies to hepatitis A virus.

The conditions for a sensitive and specific solid-phase radioimmunoassay (RIA) for the detection of IgM antibodies to hepatitis A virus (HAV) were optimized, and the RIA was used to assay sera from patients with hepatitis. IgM antibodies to HAV reached highest concentrations between one and three weeks after onset of icterus and were measurable in follow-up sera for at least 12 months after infection. To prove the specificity, the IgG antibodies were separated from patient sera by sucrose density-gradient centrifugation. The remaining IgM antibodies, after treatment with beta-mercaptoethanol, did not bind in the RIA, and, when the anti-IgM antibody bound to the solid phase was replaced with anti-IgG, a negative result was obtained with incubation of IgM antibody to HAV. Also, the presence of IgG was shown not to interfere with measurement of IgM antibody to HAV. Finally, as a further specificity control, 50 sera positive for rheumatoid factor or from patients infected with hepatitis B virus, cytomegalic inclusion disease, infectious mononucleosis, influenza A virus, rubella, or measles were tested, and all of these sera were negative for IgM antibody to HAV.

Antibodies, Anti-Idiotypic↗
PubMed1979

Influenza virus: appearance of high mouse-neurovirulent recombinants.

Recombinants from two influenza A strains that lacked mouse neurovirulence were tested, along with their parent strains, for mouse neurovirulence and for the ability to propagate in dissociated mouse embryo brain cells. The parents used were (i) strain A/Rostock/34 (FPV) (Hav1N1), with a high chicken neurovirulence, and (ii) the mouse-lung-adapted human strain Engl/1/61 (H2N2), lacking neurovirulence. In some of the recombinants high mouse neurovirulence could be detected after intracerebral inoculation of low virus doses. There was neither a correlation between surface antigen and neurovirulence nor between neurovirulence and mouse lung virulence in our system, although neurovirulence was only found in strains with Hav1 hemagglutinin. There was an association between replication in mouse embryo brain cells in culture and high mouse neurovirulence.

Animals↗
PubMed1978

Application of a solid-phase radioimmunoassay and immune electron microscopy for hepatitis A in diagnosis and research.

With crude virus suspensions from stool and antibodies from hepatitis-A patients, a solid-phase radioimmunoassay (RIA) for detection of hepatitis virus A (HVA) had antibodies against hepatitis virus A (anti-HVA) has been developed. Examples for the application of this test are demonstrated. Virus particles from the stools of the two patients were further characterized. Serologically, they were identical or very similar to the MS-1 strain. Isopycnic CsCl-gradient centrifugation of both strains revealed two peaks, but the particles of different densities did not differ in size or serologically. A modification of the RIA was also useful for determination of IgM antibodies in patients' sera fractionated by sucrose-density centrifugation. The application of the RIA method for serologic epidemiology is demonstrated by a comparison of anti-HVA prevalence in German and non-German women residing in Germany.

Adolescent↗