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Biomedical subjects

R Masseyeff

Publications and source records attributed to R Masseyeff.

At least 37 records · Page 2Linked to original sources
PubMed1982

Transfer, tissue localization and proliferation of fetal cells in pregnant mice.

Matings between Rb7-Rb7 male mice, possessing the Rb7 chromosomal marker, with CBA, C57/B1, Swiss or F1 BALB/SJL females were carried out to determine whether fetal cells transferred into maternal tissues. Rb7 cells undergoing spontaneous mitosis were sought in maternal blood, bone marrow, thymus, para-aortic lymph nodes, Peyer's patches and liver. Proliferation fetal cells were unequivocally demonstrated in maternal spleen and bone marrow, 12-21 days after mating.

Animals↗
PubMed1982

Improvement of the demonstration of A, B, H surface antigens in bladder tumors by a simple immunofluorescence technique.

The presence of A, B and H blood group antigens in paraffin-embedded tissue sections was demonstrated with a routine direct and indirect immunofluorescence technique. Natural and human antisera were used for 102 biopsy specimens of the various blood groups, including normal mucosa and vesical tumors. This technique allows a more precise description than the specific red cell adherence reaction of the differentiation pattern of the tumor itself and of the surrounding and distant mucosa. It may prove useful in suggesting a revised classification system, with more diagnostic and prognostic significance.

ABO Blood-Group System↗
PubMed1982

Role of alpha-fetoprotein (AFP) in the regulation of ovarian activity during hepatocarcinogenesis and post-natal development.

N-fluorenylacetamide produces an augmentation of serum AFP which is accompanied by a drastic decrease of ovarian activity. A passive augmentation of the AFP level of adult rats, produced by injection of this protein provokes the same phenomenon: i.e. a decrease of follicular maturation, a decrease number of corpora lutea and finally a drop in the plasma progesterone level. The study of ovarian post-natal development shows that ovarian maturity occurs on the 35th day of life when AFP level reaches its adult serum concentration. These facts support the hypothesis that AFP plays a role in the regulation of ovaries during the sexual maturation of the female rat.

Animals↗
PubMed1981

In vivo regulation of ovarian activity by alpha-fetoprotein.

Adult female rats, each injected with 760 microgram alpha-fetoprotein (AFP) weekly, presented after the third week a decrease of ovarian activity evidenced by a decreased number of maturing follicles, corpora lutea, and a drop in ovarian weight. The level of progesterone was low and agreed with the decreased number of corpora lutea. Conversely, total and free estradiol-17 beta levels remained normal despite the known ability of AFP to bind estrogenic hormones. A regulatory role of AFP during the postnatal stage of sexual maturation is proposed.

Animals↗
PubMed1981

Complement fixing activity and immunoglobulin classes of antinuclear antibodies occurring in systemic lupus erythematosus and rheumatoid arthritis.

The sera of 88 patient suffering from systemic lupus erythematosus (SLE) or rheumatoid arthritis (RA) containing antinuclear antibodies (ANA) were studied for: I) the complement fixing capacity of these ANAs: II) their immunoglobulin class. The results showed that: I) ANAs bind complement to a significant extent in 2 patients with SLE out of 3, but not in RA; II) the ANAs which bind complement belong partially or totally to the IgG class, while most of the ANAs from SLE not fixing complement belong to other classes; III) the ANAs from RA were most often from the IgM class and, surprisingly, they did not bind complement; IV) the occurrence of IgM ANA in SLE patients seems to be associated with clinical manifestations of arthritis. This double test (identification of ANA class and complement binding capacity), appears to be a valuable aid in the cases where diagnosis between RA and SLE is questionable.

Antibodies, Antinuclear↗
PubMed1981

Purification and characterization of a haptoglobin-hemoglobin complex isolated from human fetuses.

A haptoglobin-hemoglobin complex was purified from human fetuses (10-week-old pregnancies). The yield was 12% and the purification factor was about 450. The purified complex appears to have a molecular weight of 850,000 daltons. It cross-reacts with human adult haptoglobins. Its electrophoretic mobility was reduced from alpha 2- to beta-globulin when compared with the adult molecule.

Female↗
PubMed1980

A sandwich method of enzyme immunoassay. III. Assay for human beta-2 microglobulin compared with radioimmunoassay.

A sandwich enzyme immunoassay has been developed to measure human beta-2 microglobulin (beta 2m) in bilogical fluids. beta 2m is first bound by specific antibody covalently coupled to microcrystalline cellulose. The solid phase is washed and reincubated with glucose oxidase-labeled anti-beta 2m antibody. After washing, the enzymic activity of the solid phase is measured by incubation with the appropriate chromogenic substrate. The OD is directly related to the quantity of beta 2m to be measured. A second sandwich assay has also been developed which uses plastic microplates coated with the IgG fraction of rabbit anti-beta 2m serum. Reproducible results are obtained in the range 2-150 and 0.75-48 microgram/l respectively. These tests detect 17 fmoles of beta 2m. Assays of 27 sera showed good agreement between these two enzyme immunoassay methods and two radioimmunoassays.

Beta-Globulins↗
PubMed1980

Study of an enzyme immunoassay kit for carcinoembryonic antigen.

We evaluated a commercial enzyme immunoassay kit for carcinoembryonic antigen (CEA) based on a non-competitive "sandwich principle" method (Abbott Laboratories). The serum sample is treated with an acid buffer and the supernate is incubated with an anti-CEA coated polystyrene bead. After washing, the bead is incubated with an anti-CEA/peroxidase conjugate. After a second washing, the activity of the enzyme bound to the solid phase is assayed after addition of a chromogenic substrate. This activity is proportional to the concentration of CEA in the serum sample. The characteristics of the assay are: (a) good sensitivity (around 0.25 microgram/L) and (b) satisfactory reproducibility (CV < 11% within assay). There is little cross reactivity between CEA and molecules such as nonspecific cross-reacting antigens that are known for their high potential of cross reactivity. No nonspecific interference was encountered with anti-globulin factors. We compared results with this enzyme immunoassay kit with those by a radioimmunoassay provided by the Commissariat à l'Energie Atomique. The correlation (r) was 0.95 (p < 0.001). The distribution of CEA values obtained for 1020 normal subjects is given. We conclude that the kit provides a simple and reliable procedure.

Carcinoembryonic Antigen↗
PubMed1980

[Study of a kit for the search for HBs antigen by an enzymo-immunological method (author's transl)].

The authors present a kit marketed by Abbott for searching HBs antigen by an immunological method. This technic of sandwich type included 3 stages. During a first stage, the HBs antigen eventually present was extracted from the biological fluid by a specific antibody adsorbed on a polystyrène bead. After washing, a second specific antibody labelled with peroxidase was added. After incubation and washing, the peroxidase activity of the bead was revealed by adding a chromogenic substrate. The development of a colour indicated the presence of HBs antigen in the biological fluid under study. Very simple to use, this kit permits specific detection of HBs antigen with a sensitivity comparable to that of radio-immunoassay. A good correlation was obtained with the radio-immunological kit Austria II and with the enzymo-immunological kit Hepanostika.

Antibody Specificity↗
PubMed1980

Rheumatoid factor in the elderly. New methodology.

Many authors have shown a progressive incidence of auto-antibodies in the elderly as age increases. Among the auto-antibodies found, the highest incidence concerns the Rheumatoid Factor (RF). Using an original enzyme-immunoassay of RF (RF-EIA), we were surprised to find a low incidence of RF in a sample of 100 healthy persons aged from 65 to 98 years (8%). Moreover, the finding of other auto-antibodies confirms this frequency inferior to other workers results. On the other hand, the level of present auto-antibodies is generally low, far below those usually found in auto-immune diseases. These results confirm a disturbance of the immune system in the elderly, but the levels observed make this disturbance more an humoral stigma of aging than a proof of a subjacent dysimmune disease.

Aged↗
PubMed1980

[Clinical applications of enzyme-immunoassay of rheumatoid factor].

The authors describe a method of enzymo-immunological estimation of rheumatoid factor. This estimation, of non-competitive type, includes 3 stages : the rheumatoid factor is first extracted from the serum by fixation on the aggregated IgG linked to cellulose powder; then its presence is revealed by fixation of an oxidase IgG glucose conjugate on the solid phase; finally, the enzyme activity linked to the solid phase is measured. This activity is directly related to the concentration of rheumatoid factor present. The estimation, carried out on 2 050 patients including 114 with rheumatoid arthritis, is well correlated with technic of the Rose-Waaler reaction. Furthermore, the greater sensitivity, the better reproducibility and the quantitative character of this method might improve the supervision of patients with rheumatoid arthritis.

Arthritis, Rheumatoid↗