Biomedical subjects
Publications and source records attributed to Y Manuel.
A protein of about 13,000 daltons was isolated from mouse CBA urine after inducing a tubular renal dysfunction. This protein was demonstrated similar to human Post Gamma globulin by electrophoresis, aminoacid content and immunochemical criteria.
24 h urinary alanine-amino-peptidase (AAP) and gamma-glutamyl transferase (GGT) activities were studied from the 3rd-7th month of life in male Wistar rats. A close relationship was found between AAP and GGT activity, except at the beginning and at the end of this period. At the end there appear 2 subgroups, the larger (70%) showing a strong correlation between AAP and GGT activity and the other (30%), demonstrating no correlation at all. A good correlation between AAP and GGT activities, creatinine, 24 h urine volume and 24 h creatinine output was found.
Four anti-human beta 2-microglobulin monoclonal antibodies were produced against whole lymphoid cells or against urinary beta 2-microglobulin. Their reactivity was fully inhibited by purified soluble beta 2-microglobulin. The B1.1G6, C23.24.2, and B2.62.2 antibodies bound either to free or to HLA-complexed beta 2m. They recognized the same or very close determinants, since they achieved mutual blocking. In contrast, the C21.48A1 antibody did not bind to the cell surface and did not recognize the same determinant on the purified beta 2-microglobulin molecule as the others. It was able to bind and to form a specific complex with membrane beta 2-microglobulin only, once separated from the HLA heavy chain. These data strongly suggest that the C21.48A1 antigenic determinant might be hidden when the beta 2-microglobulin is complexed with the HLA heavy chains at the cell surface.
Ten monkeys (Macacus Irus) were given 0--15 mg of lead acetate (in drinking water) 6 days a week for 9 months. Two of the monkeys were also put on a low calcium diet with 6 mg of lead acetate/day. The blood lead level usually increased from the third month according to the dose of lead ingested and more quickly in monkeys deprived of calcium. Some of the monkeys showed signs of alteration in protein glomerular filtration and/or proximal tubular reabsorption. Studies using optical and electron microscopy showed distinct pathological changes in the proximal tubular epithelium where heavy deposits of lead were seen in the nuclei.
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In the monkey, the action of four renal toxics : lead acetate, sodium maleate, cadmium chloride and sodium chromate was compared. Tubulopathies were obtained only with cadmium chloride and sodium chromate with in the best cases about 16 mg/l of beta2-microglobulin (beta2m) in the urine. Monkey and human beta2m have the same molecular weight and are antigenically similar. However, they differed in electrophoretic mobility, the monkey beta2m being slightly more cathodic.
The expression of human beta2-microglobulin (beta2m) on human spermatozoa cell surface was investigated by cytotoxicity and immunofluorescence tests. beta2m was also found in human seminal fluid by use of immunochemical techniques. Seminal fluids obtained from couples with infertility problems were tested for beta2m, albumin and total proteins concentration. A higher level of beta-2m was found in azoospermia compared with that of normal sperms.
Post gamma-globulin, first described as a constant component of protein of cerebrospinal fluid and urine from patients with tubular disorders has also been found in other biological fluids. Post gamma-globulin from a single individual always migrated as several bands after storage. Three electrophoretic forms, immunochemically identical, have been isolated by gel chromatography, preparative continuous flow electrophoresis and ion-exchange chromatography. Their molecular weight was found to be approximately between 11 000 to 12 000. No difference between the three forms could be detected. The N-terminal amino acids were found to be Lys, Arg and Leu respectively for the three forms of post gamma-globulin. The "slow" and "fast" forms of post gamma-globulin seemed to differ by elimination of small basic peptides or amino acids from the N-terminal end of the protein. No enzymatic activity of post gamma-globulin was found, but this requires further investigations.
Chromosomes in cultured lymphocytes from the following groups were analyzed: 16 workers from a smelting plant for storage batteriers in Lyon, France; 7 workers from a factory where tin dishes are made at Nerem, Belgium; and 20 controls. The choice of the workers was made on the basis of either elevated blood lead (Lyon) or elevated urinary delta-aminolevulinic acid (Nerem). An increased number of severe aberrations--rings and dicentrics--were detected in the persons from Lyon, whereas no such aberrations but an increased number of fragments were seen in those from Nerem.
Immunological nephelometric analysis has been shown to be a more sensitive method than either immunoelectrophoresis or gel-diffusion for testing the gel-filtration method of human immunoglobulins sera. This method has the advantages of facility, rapidity and sensitivity. We have compared this method to radial immunodiffusion. This method can be applied to locate with precision any antigens after gel-filtration or ion-exchange chromatography.
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Six beta2-microglobulins were isolated from the urine of six patients with renal tubular dysfunction. Cross-reactivity between these beta2-microglobulins and antigenic determinants of different IgG allotypes and subclasses was investigated. No evidence of cross-reactivity was found. Some hypotheses are discussed concerning these results.
The authors propose a convenient method for the separation of low molecular weight proteins, present in tubular urines. In particular, the method is used for the purification of beta2 microglobulin, after one recycling, and also for the isolation of the various post-gamma globulins which can later be separated on DEAE Sephadex.
Low molecular weight (LMW) proteinurias vary widely in their microprotein composition. In general, there is little correlation between a given microprotein composition and a defined clinical disease (with the exception of the predominant beta-2-microglobulin in Wilson's disease). Free immunoglobulin light chains are a practically invariable component of, and may be the only detectable LMW protein in, 'tubular' proteinuria. The origins and significance of some frequently occurring urinary LMW proteins are discussed.
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The antibody-induced redistribution of beta2-microglobulin (beta2-micro) and HL-A antigens on the surface of living lymphocytes was studied by immunofluorescence. When all beta2-micro was redistributed on the lymphocyte membrane by specific rabbit antibodies and goat antirabbit Ig conjugates, the HL-A antigens were no more detectable with anti-HL-A conjugates outside the beta2-micro caps already formed. However, the redistribution of HL-A antigens fails to provoke the redistribution of all detectable beta2-micro molecules. These results suggest that HL-A antigens may be associated with beta2-micro at the cell surface, but that all beta2-micro molecules are not bound to HL-A antigens.
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