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Biomedical subjects

H P Lehmann

Publications and source records attributed to H P Lehmann.

7 recordsLinked to original sources
PubMed1992

Tumor-antigen-specific humoral immune response of animals to anti-idiotypic antibodies and comparative serological analysis of patients with small-cell lung carcinoma.

We have previously developed 3 monoclonal anti-idiotypic antibodies (Ab2) of LOU rat origin directed against the binding site of the murine monoclonal IgM LAM8, which recognizes the small-cell lung carcinoma (SCLC)-associated sialoglycoprotein antigen sGP 90-135. The aim of this study was to compare the efficiencies of these 3 Ab2, designated LY8-229, LX8-531 and LX8-632, to induce antigen-specific immunity in different animal species without prior exposure of the recipients to the nominal antigen, and thereby possibly select an Ab2 candidate for active immunotherapy against SCLC in patients. The feasibility of this approach was further evaluated by a serological analysis of patients with SCLC compared with healthy individuals, in whom the spontaneous antibody reactivities against SCLC cell lines and Ab2 were tested. LY8-229 was shown to be the most effective Ab2 in inducing antigen-specific antibodies in BALB/c mice, CBA/J/Zur mice and one NZW rabbit. Furthermore, LY8-229 was the only Ab2 against which significantly elevated idiotype-specific antibody reactivities existed in sera of patients with SCLC. These reactivities correlated positively with binding to antigen-positive tumor cells. Our findings suggest that LY8-229 represents in its reactivity pattern the nominal SCLC antigen in humans also, and therefore may be of diagnostic and possibly therapeutic relevance for patients with SCLC.

Animals↗
PubMed1991

Polyclonal anti-idiotypic antibodies mimicking the small cell lung carcinoma antigen cluster-5A interact with a panel of antibodies and induce specific immune response in animals.

Polyclonal anti-idiotypic antibodies (ab2) were generated by immunising goats with the murine IgG2a monoclonal antibody SWA20 which recognises the SCLC antigen cluster-5A, a tumour-associated sialoglycoprotein. Ab2 was shown to bind specifically to antibody SWA20, but not to isotype matched control antibodies. Pre-incubation with ab2 completely inhibited target cell binding of antibody SWA20 and of four other antibodies to cluster-5A antigen, while no effect was seen with antibodies to cluster-1 and cluster-w4 antigen. By these criteria the ab2 population consists of antibodies resembling in their reactivity pattern the cluster-5A antigen. Ab2 was used for immunisation of rabbits and two strains of mice; control animals received PBS or nonspecific goat IgG. Anti-anti-idiotype sera (ab3) were analysed in a series of radioimmunoassays for reactivity with goat IgG and reactivity with ab2. After blocking the nonspecific anti-goat response, ab3 could be shown to bind specifically to ab2 idiotype. As examined by an indirect cell ELISA with fixed cells, two out of six ab3 sera showed significantly higher binding ratios to antigen-positive SW2 cells as compared to antigen negative control cells. These findings indicate that the goat anti-SWA20 idiotype antibodies functionally represent the SCLC antigen cluster-5A and therefore may have potential for modulating the anti-tumour response through idiotypic network interactions.

Animals↗
PubMed1979

SI units.

The development of the International System of Units (Systeme International d'Unites--SE Units), based on seven fundamental quantities--length, mass, time, electric current, thermodynamic temperature, luminous intensity, and amount of substance is described. Units (coherent and noncoherent) for other measurable quantities that are derived from the seven basic quantities are reviewed. The rationale for the use of SE units in medicine, primarily as applied to clinical laboratory data, is discussed, and arguments are presented for the rigid adoption of SI units in medicine and for exceptions. Tables are given for the basic and derived SI units used in medicine and for conversion factors from the quantities and units in current use to those in SI units.

Blood Chemical Analysis↗
PubMed1976

Automated assay of ceruloplasmin by kinetic analysis of o-dianisidine oxidation.

Automated procedures for the kinetic assay of serum ceruloplasmin activity using a bichromatic and a centrifugal analyzer are described. The method is based on the oxidase activity of ceruloplasmin at pH 5.0 with o-dianisidine as substrate. Enzyme activity is reported in I.U./l, based on the molar absorption coefficient of o-dianisidine consumed. The substrate is stable and is not subject to non-enzymatic oxidation. Comparison with a manual reference end-point assay using the same substrate indicates good correlation of the bichromatic and centrifugal methods. The analytical precision is comparable to the manual assay for both methods.

Autoanalysis↗
PubMed1976

Metrication of clinical laboratory data in SI units.

The development and general concepts of the Système International d'Unités (SI units) are discussed. The basic and derived quantities and units of the SI used for clinical laboratory data are reviewed. Ranges of normal values for a number of body fluid constituents are given in the units in current general use and in SI units, with corresponding conversion factors.

Australia↗
PubMed1976

Micromethod for analysis for chloride in physiological fluids.

A micromethod for the analysis for chloride, based on the chemical precipitation of silver chloride by radial diffusion through agar gel containing silver nitrate, is described. The method is simple to run, requires little or no instrumentation, and requires only 10 mul of sample. Results by coulometric titration (Buchler Cotlove Chloridometer) correlated well for serum (r = 0.961), urine (r = 0.997), cerebrospinal fluid (r = 0.991), and sweat (r = 0.998). Other halide ions or protein do not interfere. Precision studies gave a within-day reproducibility (CV) of 1.3% and a day-to-day variability of 2.1% for a serum sample averaging 115 mmol/liter.

Agar↗