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Biomedical subjects

F Heinz

Publications and source records attributed to F Heinz.

At least 37 records · Page 2Linked to original sources
PubMed1988

On the epidemiology and etiology of pneumonia in adults.

In a group of 74 hospitalized patients with the diagnosis of acute infectious pneumonia, the etiological contribution of viral and bacterial agents is analyzed in cases of clarified etiology and an assessment is made of the relationship between the explained etiology and the overall epidemiological situation. Etiology was clarified in 36 patients (48.6%). Viral and bacterial etiology was confirmed in 13.3% and 39.8% of the entire group respectively. In three cases, mixed viral and bacterial infection was reported. Most prominent among the viral agents were herpes simplex, parainfluenza, respiratory syncytial and influenza type B viruses. As far as the bacterial agents were concerned, the species most frequently isolated were Staphylococcus aureus, Streptococcus pneumoniae and a variety of Enterobacteriaceae. The relationship between the overall epidemiological situation and pneumonia etiology is discussed as well as the relevance of the diagnostic methods employed.

Adult↗
PubMed1986

Influenza activity in Czechoslovakia and the USSR, 1980-1985.

Between 1980 and 1985, Czechoslovakia had experienced 4 and the USSR 3 major influenza outbreaks. Of the 3 epidemic outbreaks in the USSR, 2 were associated with influenza B virus (in the 1980/81 and 1983/84 seasons) and 1 with influenza A virus of the H3N2 subtype. In the USSR, influenza A (H1N1) virus never predominated as a cause of epidemic during the 5 years period. In Czechoslovakia, 2 epidemics (in the 1980/81 and 1983/84 seasons) were due to influenza A (H1N1) virus. The epidemic in the 1981/82 season had two waves of unequal heights and a mixed type B and subtype A (H3N2) etiology; a two-wave epidemic associated with isolates of influenza A (H1N1) and influenza B viruses was also recorded in the 1983/84 season. The influenza A (H3N2) epidemic in 1983 was of explosive character. All influenza viruses circulating in the two countries between 1980 and 1985 were of the same antigenic profile, but were isolated from the epidemics that occurred in different influenza seasons. The virological surveillance revealed strains of virus closely related to drift variants detected from outbreaks in 1977-1979 and the new variants A/Chile 1/83, A/Philippines 2/82, A/Caen 1/84 and B/USSR 100/83.

Czechoslovakia↗
PubMed1984

[Heterogeneity of acetylcholine receptor antibodies in patients with myasthenia gravis].

Antibodies against the nicotinic acetylcholine receptor in sera of 21 myasthenia gravis patients were checked for their ability to block or split binding of alpha-bungarotoxin to the human acetylcholine receptor. Affinity-purified acetylcholine receptors from human skeletal muscle were used in parallel in the common precipitation assay and an inhibition assay. Cross-reactivity of acetylcholine receptor antibodies was analyzed with receptor preparation from different species (calf, rat, Torpedo c. and Electrophorus e.), purified identically to high specific activity. An antibody pattern was set up for each patient and related to the clinical state of the disease. alpha-Bungarotoxin-inhibiting antibodies were demonstrable in 74% of myasthenia gravis patients, alpha-bgt displacing antibodies were found in 39% of the investigated sera. Broad cross-reactivity with acetylcholine receptors from other mammalian muscle was evident (calf 75%, rat 90%) only very few sera reacted with acetylcholine receptors from electric fish (Torpedo c. 14%, Electrophorus e. 38%). Antibody concentrations determined by using xenoantigens were much lower than those obtained by human acetylcholine receptor. The lack of a clear-cut correlation between the amount of serum antibodies and the clinical state of myasthenia gravis can be explained by the established antibody-heterogeneity, shown by a constant antibody pattern characteristic for each patient. However, between this specific antibody pattern and the state of the disease no correlation could be established either.

Adolescent↗
PubMed1984

Physiochemical and immunological properties of acetylcholine receptors from human muscle.

The acetylcholine receptor protein from human muscle was extracted with the non-ionic detergent Triton X-100 and purified by affinity chromatography on alpha-Naja toxin sepharose 4B. Further purification on Dicap-MP sepharose 4B, a choline analog compound, led to ACHR preparations with specific activities of 2-7 nmol/mg protein. The isolated receptor, labeled with 125I-alpha-bungarotoxin was characterized by different methods and compared to ACHRs from Torpedo californica electroplax and rat-denervated skeletal muscle. Gel filtration on Ultrogel AcA 34 resulted in a stokes radius of 70 A for the receptor monomer and 99 A for the dimeric form. Sucrose density gradient centrifugation showed sedimentation coefficients of 9.1 S and 13.5 S. From these data the molecular weight of the ACHR monomer was estimated as 254 000 D and 540 000 D for the receptor dimer. The isoelectric point of the 125I-alpha-bgt-ACHR complex was determined by thin-layer isoelectric focussing to be pH 5. Purified ACHRs were used for immunization of rats and mice which developed an EAMG as verified by clinical observation and electrophysical measurements. Sera from the immunized animals as well as from myasthenia gravis patients were subsequently used to compare the cross-reactivity of ACHR preparations from different sources. While antibodies of rats immunized with Torpedo ACHRs cross-reacted with ACHR preparations from rat and human skeletal muscle, antibodies from mice immunized with rat ACHR only reacted with preparations from rats and mice. Antibodies from mice immunized with ACHR of human origin exhibited a broad cross-reactivity, as did antibodies from MG patients.

Animals↗
PubMed1983

NK cell function in severe combined immunodeficiency (SCID): evidence of a common T and NK cell defect in some but not all SCID patients.

The immunologic work-up of eight infants with the clinical diagnosis of severe combined immunodeficiency (SCID) was performed with special emphasis on natural killer (NK) cell function and ontogeny. Contrary to previous reports, our study shows that not all SCID patients lack NK activity; some may even express very high NK- and antibody-dependent cellular cytotoxicity (ADCC). The present group of eight SCID infants was homogeneous with respect to normal levels of the purine metabolism enzymes adenosine deaminase (ADA) and purine nucleoside phosphorylase (PNP). They all had low serum Ig levels and were defective for specific antibody formation against BSA and diphtheria toxin (DiT). None of the infants' peripheral blood mononuclear cells (PBMC) proliferated significantly upon in vitro stimulation with PHA, concanavalin A (Con A), pokeweed mitogen (PWM), and irradiated allogeneic lymphocytes. Seven of eight patients, however, responded significantly to mitogenic factors present in a lectin-free interleukin 2 (IL 2) preparation, and two exhibited a positive costimulation as well with simultaneous exposure to IL 2 + Con A. The lymphocyte marker analysis revealed high percentages of OKT10+ cells in seven of eight infants, whereas peripheral T cells (OKT3+) with suppressor/killer (OKT8+) or helper/inducer (OKT4+) phenotypes were abnormally low in all infants with one exception. The PBMC of two patients formed low to normal percentages of E rosettes but expressed no B cell markers (B-/SCID). The six other infants had high percentages of B cells (B+/SCID) but lacked E rosette-forming cells. High NK and ADCC activity was found in the two B-/SCID patients. The B+/SCID infants either totally lacked NK and ADCC function (four of six) or expressed low to normal NK activity together with some T cell markers as revealed by monoclonal antibody staining but not by E rosette formation (two of six). From the data presented, an ontogenic model is proposed that assumes the status of an independent cell lineage in between T cells and monocytes for human NK cells, or that places these cells in close proximity to early differentiation steps of the T cell lineage. In any case, NK cell function clearly constitutes an additional parameter of heterogeneity in the immunologic analysis of SCID.

Adenosine Deaminase↗
PubMed1981

Purification and characterisation of the cyclic AMP-dependent protein kinase, the C- and the R-protein from bovine liver.

A cyclic AMP-dependent protein kinase, its regulatory (R) and catalytic (C) protein were isolated from bovine liver, The cyclic AMP-dependent protein kinase showed two protein bands on SDS-polyacrylamide gel electrophoresis with molecular weights of 54 000 and 40 000. They correspond to the data for the separately isolated R-and C-protein. The molecular weight of the holoenzyme ranged from 172 000-179 000, depending on the estimation method. The molecular weight of the R-protein ranged from 97 000-98 000. This, and the results of the SDS-polyacrylamide gel electrophoresis, demonstrates a dimeric structure. The frictional ratios (f/fo) of 1.67-1.7 for the holoenzyme and 1.9 for the R-protein correspond to highly asymmetric shapes. Assuming a prolate form, the axial ratios are 13-14 and 17, respectively. The C-protein is globular (f/fo 1.1-1.26, axial ratio 3-5). The secondary structure with 35% alpha-helix, 19% beta-sheet and 49% aperiodic form of the holoenzyme is similar to the R-protein with 35, 19 and 46%, respectively. The C-protein contains 29% alpha-helix, 21% beta-sheet and 50% aperiodic form. The dimeric R-protein binds 4 mol cyclic AMP and can be phosphorylated in the presence of the C-protein. An absorption coefficient, A280nm 1.0%, of 5.4 was calculated for the R-protein and of 13.6 for C-protein. The data for C-protein, e.g., molecular weight, heterogeneity in isoelectrofocusing, phosphate content, etc., are in good agreement with those found by Sudgen, P.H. and Corbin, J.D. (1976) biochem. J. 159, 423-437.

Amino Acids↗
PubMed1981

Serological diagnosis of acute tick-borne encephalitis by demonstration of antibodies of the IgM class.

A sensitive enzyme immunoassay is described for demonstrating specific antibodies of the IgM class to tick-borne encephalitis virus (anti-TBEV IgM). Anti-mu-coated, flat-bottomed microtiter plates are incubated with diluted patients' serum (2 hr at 37 degrees C), then with purified TBEV, and later with peroxidase-coupled anti-TBEV immunoglobulin for a further 2 hr. After washing the plates, orthophenylenediamine is added and the optical density is measured at 510 nm. At an early stage after onset of illness anti-TBEV IgM could be demonstrated up to serum dilutions of 10(-4). The specificity of the test system was shown by total inhibition of the positive reaction by preincubation of patients' sera with anti-mu. Tick-borne encephalitis (TBE) could be diagnosed serologically in 54 patients by the described method, and anti-TBEV IgM could be demonstrated in sera drawn up to 9 months after onset of illness. A peak in the number of infections occurs in the age group of 31-40 years, and most infections occur from June to October with a small peak in July.

Adolescent↗