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Biomedical subjects

F Deinhardt

Publications and source records attributed to F Deinhardt.

At least 73 records · Page 4Linked to original sources

Carrier bound synthetic oligopeptides in ELISA test systems for distinction between HIV-1 and HIV-2 infection.

A series of synthetic carrier bound oligopeptides derived from corresponding regions of the core and envelope proteins of HIV-1 and HIV-2 were used in enzyme-linked immunoabsorbent assays (ELISA) for serodiagnosis of HIV-1 and HIV-2 infected individuals. The combination of peptides from regions either conserved or highly variable between the two virus types allowed the identification of HIV infection in general and the differentiation between HIV-1 and HIV-2. No specific reaction was found in seronegative individuals. The use of peptides bound to the same polystyrene carrier as in peptide synthesis allowed the establishment of a highly specific and sensitive test system without the risk of unspecific cross-reaction due to contamination with bacterial or cellular protein material.

Acquired Immunodeficiency Syndrome↗

[The critical 3-day fever-exanthema in young children (exanthema subitum, Zahorsky roseola infantum)--what is new?].

As to the present knowledge the critical rose rash of infants (exanthema subitum, roseola infantum) means to be an exanthematous infectious disease that, occurring preferably in elder babes and younger infants (1st--3rd year of life), is caused by the newly detected herpesvirus (now the sixth one) pathogenic for man. The natural contamination in our latitude is intense (60-75%), and the probably lifelong immunity in the majority of cases is acquired in infancy. Though experts in the clinical subject do stress all the time the exanthema subitum to be the most frequent exanthematous disease in early infancy and infancy, infection chains tested to exanthema, respectively epidemics are observed decidedly seldom. Consequently, most of all infections use to develop clinically inperceptibly or even with other symptoms (and without an exanthema); the exanthema up to now obligatory for establishing the diagnosis uses to appear only in the minority of all cases and in the great majority of them the seroconversion is clinically silent. The prognosis of the exanthema subitum is in force to be good; the disease is the special field of activity for ambulatorily acting physicians (paediatrist, general practitioner). To begin with, the status diagnostically unclear and high-febrile for several days, the central-nervous excitability occurring in many cases, and in some children the appearing of dramatic febrile convulsions, as well as gastroenteric symptoms perpetually give rise to differential diagnostic considerations and sometimes even to a (false) antibiotic therapy. In case of an affection by herpesviruses principally a latency (persistence) of the virus lasting for years (possibly even lasting for life) in human beings is to be taken into account; this condition is also current for HHV 6. On occurring of an immune debility a release and a discharge of herpesviruses--not only by children suffering from an exanthema subitum (!)--are possible so that human beings of each age may come into question to be the source of infection. Double infections of human immune cells (for instance HHV 6 and HIV 1 simultaneously) already have been found. The necessary studies in order to clarify essential clinical and virological problems are world-widely in full activity, and new cognitions (further symptoms of diseases associated with HHV 6, possibly affections in prenatal infections and so on) are soon to be taken into account.

Child, Preschool↗

[New knowledge of Zahorsky exanthema subitum (critical 3-day fever-exanthema, roseola infantum].

A survey is given on the history, characteristic symptoms and recent data of the etiology of exanthem subitum (Zahorsky's disease, sixth disease, roseola infantum). Some cases are presented and modern diagnostic techniques for atypical cases are discussed. The disease is caused by an infection with the human herpesvirus-6 (HHV 6; syn.:, "human B-lymphotropic virus", HBLV). Most babies and small children have an asymptomatic infection usually leading to lifelong immunity. The typical "exanthem subitum" develops only in a minority of the infected and susceptible persons. We suggest that the novel human herpesvirus-6 also has the potential of lifelong persistence in humans and can then be shedd at any age in case of acquired immunodeficiencies. World-wide research in this field is carried out by several working groups and new data will be available in a few years.

Antibodies, Viral↗

[HIV testing in general practice].

In the third quarter of 1987 a questionnaire was sent to 350 consecutive patients of a general practice for the purpose of ascertaining patients' willingness to be tested (if desired, anonymously) without charge for antibodies against human immunodeficiency virus (HIV). They were asked, among other questions, about their reasons for or against wanting the test, previous blood transfusions, drug dependence, homo- or bisexuality, and sexual contact with heroin addicts. Nearly half the questionnaires (162 were completed and returned. Of the responding patients 60% voted for, 40% against the test. The large majority of those for it reported no previous risk factors but wanted to have what they assumed would be a negative test confirmed in writing. In addition to this questionnaire study all clinical and anamnestic indications for HIV testing were documented over a six-month period (16 cases). Two heroin addicts and a homosexual male had a positive anti-HIV test, while all others were negative.

Acquired Immunodeficiency Syndrome↗

The high efficiency, human B cell immortalizing heteromyeloma CB-F7. Production of human monoclonal antibodies to human immunodeficiency virus.

This paper describes the construction of a new heteromyeloma cell line designated CB-F7. The cell line was derived from xenogeneic somatic cell hybridization between normal human B lymphocytes and the murine HAT-sensitive P3X63Ag8/653 cell line. CB-F7 cells were characterized by rapid cell growth (doubling time about 16 h) and high cloning efficiencies in culture medium supplemented with 10% or 5% fetal calf serum, respectively. The karyotype of the cells consists of about 75-78 chromosomes as well as two chromosomal fragments. Fusions of the cells with human peripheral blood cells resulted in approximately 2-6 clones per 10(5) seeded lymphocytes. Furthermore, the cells are ouabain resistant and therefore suitable for fusions with EBV-transformed lymphoblastoid cell lines. Using CB-F7 as the parental cell line a number of specific human mAb producing hybrids were established. For the first time, we describe here the generation of hybrids secreting human monoclonal antibodies to human immunodeficiency virus (HIV). Two monoclonal antibodies of IgG type and one of IgM type reacted with the major core protein p25 and one IgG antibody reacted with the transmembrane protein gp41.

Antibodies, Monoclonal↗

Immunoreactivity of human and rabbit antisera to hepatitis A virus.

Rabbit antibodies produced by immunization with complete hepatitis A virions (HAV) recognized all the viral structural proteins and neutralized HAV infectivity in cell culture. Rabbit antibodies to chromatographically purified individual viral proteins and to synthetic peptides representing epitopes on the structural viral protein VP1 neither recognized whole virus nor neutralized infectivity, indicating that native epitopes on the virus surface are necessary for virus recognition and neutralization. Human anti-HAV-positive sera of the acute and convalescent phase of disease recognized and neutralized viral particles. Analysis of the immunoreactivity of these human sera in immunoblot showed that the IgM antibody preferentially recognizes the structural viral proteins VP0 and VP3 of HAV, whereas IgA and IgG antibodies reacted more strongly with VP1.

Animals↗

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↗

AIDS: no association with the genetic systems GC (D-binding protein), ORM (orosomucoid = alpha-1-acid glycoprotein), and A2HS (alpha-2-HS-glycoprotein).

In a sample of 97 HIV-1 seropositive persons which comprised 34 patients with AIDS, 30 patients with persistent generalized lymphadenopathy or with AIDS related complex and 33 persons who were without symptoms and called "healthy", three genetic marker systems were examined: 1) GC, the group-specific component of serum which is identical with the vitamin D binding protein (DBP) of serum, 2) ORM, the acute phase protein orosomucoid = alpha-1-acid glycoprotein of serum, and 3) A2HS, the alpha-2-AS glycoprotein of serum. The distribution of the genotypes and of the alleles in the sample of AIDS patients and of HIV-1/positive persons was not different from the distribution in control groups. An association between susceptibility and/or resistance for AIDS and these genetic marker systems was not observed.

Acquired Immunodeficiency Syndrome↗

Human parvovirus B19: ELISA and immunoblot assays.

An ELISA for the detection of specific IgM and IgG against human parvovirus B19 (anti-B19 IgM and IgG) and B19 antigen is described. With ELISA anti-B19 IgM could be detected for up to 20 weeks after viraemia. Four to five months after B19 infection anti-B19 IgG titres range between 10(-6) and 10(-7). Nonspecific reactions with rheumatoid factor or IgM against rubella were not found. The ELISA for B19 antigen was shown to be as sensitive as DNA hybridisation. With immunoblotting two viral proteins of 83 kd (VP1) and 58 kd (VP2) were demonstrated. After acute infection antibodies to VP2 appear before antibodies to VP1. Immunoblotting might be used in pregnancy to determine the time of maternal infection. In a survey of a B19 outbreak in a school for medical technology, 6 (28.6%) of 21 non-immune females seroconverted.

Antibodies, Viral↗

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↗

Interferon alpha in hepatitis type B and non-A, non-B. Defective production by peripheral blood mononuclear cells in chronic infection and development of serum interferon in acute disease.

The production in vitro of interferon alpha and gamma by peripheral blood mononuclear cells of 25 patients with chronic hepatitis B and 13 patients with chronic hepatitis non-A, non-B was compared to that of healthy controls. Following induction by Molt 4 leukemia cells (P less than 0.001) and influenza A/X31 virus (P less than 0.01), there was a significantly lower interferon alpha response in patients with chronic hepatitis B and chronic hepatitis non-A, non-B. Yields of interferon gamma in patients with chronic hepatitis were comparable to those of normal individuals. The degree of interferon deficiency did not correlate with severity of liver disease. In patients with chronic hepatitis B, viral replication (presence or absence of HBeAg) was not related to the defect in interferon alpha production. Three of 10 patients with acute hepatitis B had measurable antiviral activity in the serum for 3-5 days after the onset of jaundice.

Acute Disease↗

A new second-generation anti-HIV-1 enzyme immunoassay using recombinant envelope and core proteins.

In a multicenter collaborative study a new second-generation HIV-1 antibody enzyme immunoassay (Abbott recombinant HIV-1 EIA) using Escherichia coli-expressed recombinant p24 and p41 proteins as solid-phase antigens was compared with the first-generation H9 cell-line-based Abbott HIV-1 EIA. The results of the confirmatory assays (Western blot, immunofluorescence), combined with clinical information, were used as the reference standard for the detection of HIV-1 antibodies in 10,676 random blood donor serum specimens, in a panel of 840 specimens from symptomatic and asymptomatic patients and a total of 63 serial blood specimens from 23 people at risk. With fresh blood donor sera, the specificity of the first-generation assay ranged between 99.54 and 99.76% (95% confidence limits, CL) compared with 99.81-99.95% (95% CL) for the second-generation EIA. With panel specimens the recombinant HIV-1 EIA achieved an overall sensitivity of 100% and a specificity range of 98.3-99.7% (95% CL); the corresponding sensitivity and specificity ranges observed for the first-generation EIA were 98.0-99.5% (95% CL) and 94.3-96.8% (95% CL), respectively. The improved sensitivity for the second-generation assay was confirmed by testing serial samples from seroconverting patients. The use of recombinant proteins eliminated non-specific reactions due to class II human leukocyte antigen (HLA)-directed antibodies.

Blood Donors↗