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Biomedical subjects

A J Pesce

Publications and source records attributed to A J Pesce.

At least 73 records · Page 4Linked to original sources
PubMed1983

Pitfalls and errors in drug monitoring: analytical aspects.

Drug analyses, whether for purposes of evaluating new drug products or as part of clinical monitoring programs, have become frequently requested tests in both clinical and industrial laboratories. From the time of phlebotomy, throughout the transportation, processing and storage of the specimen, during the actual analytical procedure and throughout the clerical reporting of the data, certain potential errors and limitations in the system exist which should be fully recognized for proper evaluation of the laboratory data.

Humans↗
PubMed1982

Immunochemical cross-reactivity between cyanogen bromide fragments of human serum albumin.

The antigenic structure of human albumin was investigated in order to establish whether or not there was any similarity between its antigenic sites. Using immunoadsorbent columns prepared with cyanogen bromide fragments of human serum albumin, antibodies directed against different portions of the albumin molecules were isolated. Measurement of the amount of the antibodies isolated and study of their specificity by inhibition techniques show that these subpopulations of antibodies reacted not only with the fragment used for their isolation (homologous) but also with the other fragments (heterologous). Heterologous fragments were inhibiting only at a very high concentration with regard to the homologous ones. These results show that there is a weak cross-reactivity between different portions of the albumin molecule. This reaction is most probably due to the homology existing in the sequence of the human albumin molecule which has arisen by gene duplication. The same type of behavior can be predicted to extent to other molecules which have evolved by similar mechanisms.

Cross Reactions↗
PubMed1982

Evaluation of the peroxidase-antiperoxidase method for demonstrating cell membrane B2-microglobulin.

The peroxidase-antiperoxidase (PAP) immunohistochemical technic was evaluated for its usefulness in studying B2-microglobulin (B2m) expression in the cell membrane of human tumor lines grown in athymic mice. Eleven human tumor xenograft lines expressing various amounts of B2m were used. B2m was assessed by three methods: PAP technic on formalin-fixed, paraffin-embedded tissue; indirect immunofluorescence on frozen sections; and radioimmunoassay on soluble tumor extracts. The three technics gave comparable results, and the PAP technic proved to be useful in evaluating B2m.

Animals↗
PubMed1981

Specificity of two anti-human albumin monoclonal antibodies.

We have studied the reaction of two monoclonal anti-human albumin antibodies with various fragments of albumin comprising the entire molecule. Using solid phase assay, inhibition of enzyme immunoassay and of passive hemagglutination, they were shown to be specific for a fragment F1, of 6000 dalton, located near the C terminus of human albumin. In addition, these antibodies reacted weakly with fragment D which corresponds to the N terminal half of the molecule.

Antibodies, Monoclonal↗
PubMed1981

Heterogeneity of beta 2-microglobulin in human breast carcinoma.

beta 2-microglobulin (beta 2m) content and distribution in human benign and malignant breast tissues have been investigated by immunohistologic means, and wide differences in the expression of this protein have been observed. The distribution of beta 2m as determined by indirect immunofluorescence was uniform throughout normal human and benign breast tumor tissues, as well as in human tumor xenografts grown in athymic mice, but marked difference in beta 2m content was demonstrated between individual tumors. In breast carcinomas, heterogeneity in beta 2m expression was found to exist within individual tumors. This heterogeneity was evident mainly in moderately well-differentiated tumors; the majority of poorly differentiated tumors did not express beta 2m at all. It is suggested that the expression of surface beta 2m is an indicator of tumor cell differentiation or maturation.

Animals↗
PubMed1981

Immunoenzymometric assays for simultaneous quantitation and distribution of erythrocyte antigen.

We describe an adaptation and modification of the enzyme-labeled immunosorbent assay (ELISA), which yields information on the quantity and distribution of surface antigens on erythrocytes. The distribution assay, named "ELADA" (for Enzyme-Linked Antigen Distribution Assay), involves use of an alkaline phosphatase-immunoglobulin conjugate with alpha-naphthol phosphate and a diazonium salt as substrate. The insoluble reaction product forms a complex on the cell surface at the location of the antigen. Antigens in aliquots from the same enzyme-immunoglobulin conjugate are quantified with the soluble substrate p-nitrophenyl phosphate. One can thus establish whether the distribution of erythrocyte antigens is random by examining the ELADA-stained cells with a scanning electron microscope. Combining the quantitative ELISA with measurements of cell numbers makes it possible to estimate the number of antibody molecules-and thus the number of antigenic sites per cell. By using various modified antisera, substituted naphthol phosphates with higher avidities, and reaction conditions designed to optimize the kinetic reaction, we have been able to resolve the enzyme product deposited on the antigenic site to within 20 nm. It is not always possible to decide whether each deposit represents a cluster of antigenic determinants or a single determinant; however, if the number of antibody sites is known from ELISA quantitation, information about the number of antibody sites per deposit can be ascertained.

Adult↗
PubMed1980

Immune complexes in transitional cell carcinoma.

Bladder cancer patients from 2 different medical centers were examined to establish whether such patients have circulating immune complexes. Four methods of analysis were used: 1) polyethylene glycol precipitation, 2) double crossed immunoelectrophoresis, 3) Raji cell and 4) Clq binding assays. In the first group of 24 patients 17 had positive results on cystoscopy for pathologically defined tumors at the time of the serum sample. Two tested positive for the presence of circulating immune complexes by all 4 techniques and an additional 1 tested positive by 3 of the 4 techniques. In the second group of 54 patients (41 of whom had pathologically definable tumors at sample date) 9 were judged possibly positive by the Raji cell assay, the polyethylene glycol and double crossed immunoelectrophoresis techniques. When tested by the Clq binding assay 8 of the 9 patients were positive, most being in the range of 260 to 320 microgram/ml. immune complex. Combining all data from the 78 patients with bladder cancer the results in 10 cases definitely were positive by all 4 techniques and an additional 2 were positive by 3 techniques. Our data indicate that a low percentage (13 to 15 per cent) of patients with bladder cancer has circulating immune complexes. Of interest is that the complexes, as judged by our assay procedures, bind Clq, contain aggregated IgG and can be dissociated into antigen and antibody. Thus, the immune complexes are similar to those found in immune complex diseases.

Aged↗
PubMed1980

Occupational exposure to lead: effects on renal function.

Although nephrotoxicity is common following exposure to lead, the dose-response relationship in adults with occupational exposure is not well understood because information is lacking on early nephrotoxic effects. By the time serum urea nitrogen and creatinine levels are elevated, renal damage may be advanced and not fully reversible. Detailed investigations of renal glomerular and tubular function were performed in six adults with occupational exposure to lead. In all patients, the serum creatinine and urea nitrogen concentrations were within the normal range. GFR was decreased in all but two. Glucose reabsorptive capacity (TmG) was decreased in all, and this decrease was disproportionately greater than expected from the reduced GFR in all but one. Normal values for renal plasma flow (RFP) were observed in four of the six, and for rho-aminohippurate (PAH) secretory capacity (TmPAh) in all but one. Bicarbonate reabsorptive capacity (TmHCO3) and urinary excretion of beta2-microglobulin were normal in all. Routine clinical laboratory tests are insensitive for the detection of early renal effects of heavy metal exposure. Measurements of renal tubular reabsorptive capacity for glucose appears to be a sensitive method for the early detection of renal effect of lead.

Adult↗
PubMed1980

ELISA assay for measurement of human hemoglobin A and hemoglobin F.

An enzyme-linked immunosorbent assay (ELISA) for the measurement of nanogram quantities of hemoglobin A and hemoglobin F is described. The assay employs hemoglobin bound to polystyrene test tubes. The antigen is quantitated by the addition of rabbit antibody specific for the hemoglobin type, followed by a second antibody of goat antirabbit gamma globulin coupled to alkaline phosphatase. Quantitation of the reaction is achieved by incubating the coated tubes with p-nitrophenyl phosphate. The binding characteristics, the linearity, the ability of the assay to discriminate between hemoglobin A and hemoglobin F, the ability to discriminate between native and denatured gamma globin, and the comparison of this assay with a previously described immunoradiometric (IRMA) assay are discussed.

Adult↗