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Biomedical subjects

A Eyquem

Publications and source records attributed to A Eyquem.

At least 19 recordsLinked to original sources
PubMed1987

Co-localization and secretion of parathyrin of Stannius corpuscles (immunoreactive parathyroid hormone) and of secretory glycoproteins including secretory protein-I in the European eel (Anguilla anguilla L.).

Until recently, teleosts were considered to be devoid of parathyroids. We showed recently that the corpuscles of Stannius, that structurally have features in common with the parathyroid gland, produce a molecule resembling mammalian parathyroid hormone (PTH). We refer to this molecule as parathyrin of corpuscles of Stannius (PCS). Parathyroid secretory protein-I (SP-I) is an acidic glycoprotein, probably identical to adrenal chromogranin A, that is co-stored and co-secreted with PTH. In the present study, PCS was localized in secretory granules of fresh water eels by immunocytochemistry. In addition, several glycoproteins were identified in these granules by periodic acid-Schiff staining and/or concanavalin A lectin binding. One of the glycoproteins that was positive with periodic acid-Schiff, but not with concanavalin A, cross-reacted with antisera to bovine parathyroid secretory protein-I. When the eels were made hypercalcemic by injecting calcium or pituitary extract, there was a coincidental translocation of the PCS, immunoreactive SP-I and the glycoproteins, suggestive that these granules were undergoing exocytosis. Immunoblot analysis of saline extract of the corpuscles of Stannius confirmed that immunoreactive SP-I was present in the tissue. It exhibited a molecular mass of about 55 kDa compared to about 70-80 kDa exhibited by mammalian SP-I when analyzed by sodium dodecylsulfate-polyacrylamide gel electrophoresis.

Animals↗
PubMed1986

IgG-subclass expression of anti-DNA and anti-ribonucleoprotein autoantibodies in human malaria.

To understand further the autoimmune phenomena associated with human malaria, we examined the IgG-subclass expression of antibodies to DNA and to ribonucleoproteins (RNP) in the serum of 99 patients with acute malaria. Of the sera, 22% were positive for single-stranded DNA (ssDNA), 18% for double stranded DNA (dsDNA) and 32% for RNP. Using a set of human IgG-subclass-specific murine monoclonal antibodies, we found that autoantibodies to dsDNA were predominantly expressed in the IgG1 subclass. In contrast, anti-ssDNA antibodies were more evenly distributed among the three other isotypes. Antibodies to RNP were essentially of the IgG1 and IgG2 isotypes. However, there was no correlation between these restricted IgG-subclass in the sera. These results are discussed in the context of previous findings of isotype expression of these autoantibodies in patients with the autoimmune disease systemic lupus erythematosus.

Acute Disease↗
PubMed1985

Suppression of murine lupus autoantibodies to DNA by administration of muramyl dipeptide and syngeneic anti-DNA IgG.

We evaluated the effect of repeated subcutaneous administration of syngeneic anti-DNA IgG and muramyl dipeptide, a synthetic immunoadjuvant, to 6-mo-old (NZB X NZW)F1 female mice. This treatment had profound effects on both idiotype expression and anti-DNA antibody levels of morbid mice. It was also associated with appearance of anti-idiotypic antibodies specific for the injected antibody. These findings suggest that this approach with the use of synthetic immunomodulators and syngeneic antibodies may be of potential use in the management of autoimmune diseases.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1985

[Value of the detection of antithyroid antibodies in thyroid pathology].

Antithyroid microsomal hemagglutination antibody (MCHA) and antithyroglobulin hemagglutination antibody (TGHA) were measured in 629 patients with thyroid disease and 100 controls. Thyroid antibodies were present in 4% of control patients, only in women and at low titer. Thyroid antibodies prevalence was 97% in autoimmune thyroiditis (MCHA: 93%; TGHA: 53%), was 55% in Graves disease before treatment (MCHA: 46%; TGHA: 33%) and 90% in the first year following 131I therapy. Antibodies prevalence was 57% in myxoedema (MCHA: 52%; TGHA: 25%). In patients with iodine overload, antibodies prevalence was 29% in euthyroid patients, 25% in iodine-induced hyperthyroidism and 55% in iodine-induced hypothyroidism. Thyroid antibodies detection should be systematically performed in the routine evaluation of any thyroid disorder. Because of discrepancies between TGHA and MCHA positivity, their simultaneous detection should be performed.

Adenoma↗
PubMed1984

Evaluation of auto-antibodies in chronic mucocutaneous candidiasis without endocrinopathy.

Six patients with chronic mucocutaneous candidiasis (CMCC) were investigated for the presence of auto-antibodies during the course of the infection. Sera were tested for antibodies to native DNA (dsDNA) and denatured DNA (ssDNA), mitochondrial and microsomal antigens, smooth muscle, gastric parietal cells, basal membrane and skin intercellular substance, parathyroid glands, thyroglobulin and microsomal antigen, immunoglobulins and for anti-nuclear antibodies. Auto-antibodies were detected by radioimmunoassay, immunofluorescence, hemagglutination and other routine methods. Tests were performed at the end of the observation period, with the same batches of antigens and at the same time for all patients. Organ-specific antibodies (gastric parietal cells and intercellular substance) were found at low titers in five patients. Anti-smooth muscle antibodies were increased in two patients. In four patients antibodies to ssDNA were elevated. Moreover high titers of anti-ssDNA antibodies correlated well with disease activity after treatment with Ketoconazole in four tested patients. The possibility that C. albicans infection may induce auto-antibodies should be considered in assessing their disease activity significance in other chronic infected patients. The mechanisms of appearance of auto-antibodies and their immunopathological significance in CMCC are discussed.

Adolescent↗
PubMed1984

Anti-DNA autoantibody activity and idiotypic relationships of human monoclonal proteins.

Previous studies showed that polyclonal anti-DNA antibodies from patients with systemic lupus erythematosus (SLE) share cross-reactive idiotypes (CRI). In this report, we used human myeloma proteins (HMP), isolated from the serum of patients with multiple myeloma or Waldenström macroglobulinemia, as probes to further explore this idiotypic cross-reactivity. Fourty-four HMP were tested for DNA-binding capacity and for expression of CRI associated with lupus anti-DNA antibodies. Anti-DNA IgG were immunoaffinity purified from the serum of patient TOF with severe SLE. A xenogeneic anti-idiotype antibody to this IgG was raised in rabbit. This anti-idiotype recognized CRI associated with the combining site of anti-DNA IgG from unrelated SLE patients. Using inhibition competitive-immunoassays, we found that these CRI were present on all but one of the DNA-binding HMP. Furthermore, we observed that these CRI were detectable on an IgG2 lambda, a HMP devoid of anti-DNA activity. These findings are in agreement with those previously obtained in similar studies using murine monoclonal anti-DNA antibodies. These converging results suggest that antibodies expressing anti-DNA-related CRI and antibodies exhibiting anti-DNA-binding affinity constitute overlapping molecular subpopulations.

Antibodies, Anti-Idiotypic↗
PubMed1984

Antibodies to heterogeneous nuclear ribonucleoproteins in sera from patients with rheumatic autoimmune diseases.

Ribonucleoprotein (RNP) particles sedimenting at 40 S in sucrose gradients were prepared from calf thymus nuclei. They were identified as heterogeneous nuclear RNP (hnRNP) on the basis of size, electron microscopic examination, buoyant density, and protein electrophoretic patterns. Sera from patients with systemic lupus erythematosus, rheumatoid arthritis, and mixed connective tissue disease were found to interact with hnRNP by counter-immunoelectrophoresis and enzyme-linked immunosorbent assay (ELISA). Small nuclear RNP (snRNP) were purified by immunoaffinity using a monoclonal anti-snRNP antibody immobilized on Sepharose beads. Inhibition of the ELISA assay for snRNP with anti-hnRNP Fab fragments and cross-over experiments revealed that the autoantibodies detected in human sera recognize common epitopes present on snRNP and hnRNP.

Antibodies, Antinuclear↗
PubMed1984

Immunocytochemical detection in eel corpuscles of Stannius of a mammalian parathyroid-like hormone.

Stannius corpuscles of the eel synthesize and secrete a mammalian parathyroid-like hormone called parathyrin of CS (PCS). PCS has been localized in the cytoplasm of all cells in the corpuscles, detection being by indirect immunofluorescence with an antiserum anti-1-84 bovine hormone (PTH). The specificity of the reaction was demonstrated by inhibition of the fluorescent staining with 1-84 bovine PTH and the active fragment 1-34 of human PTH. Variations of the cellular localization of the PCS or a complete depletion of the hormonal content, in all cells, were observed in eels made hypercalcemic by Ca overloading. The secretory activity of the two types of CS cells may be regulated by the plasma Ca2+ concentration.

Animals↗
PubMed1984

Idiotype restriction in human autoantibodies to DNA in systemic lupus erythematosus.

Antibodies (Ab) to double stranded DNA (dsDNA) were immunoaffinity-purified from the serum of patient TOF with active systemic lupus erythematosus (SLE). Anti-idiotypic Ab to TOF anti-DNA were raised in rabbit. They were shown to recognize TOF F(ab')2 fragments, but they did not interact with human Ab of other specificities or with TOF IgG depleted of anti-DNA activity. In addition, their binding to TOF idiotype was specifically inhibited by DNA molecules. These anti-idiotype Ab therefore recognized idiotopes associated with a variable region of TOF anti-DNA-combining site. Thirty-one purified IgG anti-DNA preparations from unrelated SLE sera were able to inhibit this idiotype-anti-idiotype reaction by up to 90%. However, there was no linear correlation between anti-dsDNA Ab levels and idiotype-blocking capacity. These findings suggest that, in SLE, the idiotypic repertoire of autoAb to dsDNA is more restricted than thought previously.

Autoantibodies↗
PubMed1984

Idiotypy of anti-Rh antibodies.

Anti-id sera to Rh antibodies were produced by injecting rabbits with purified Rh antibodies. These sera were shown to agglutinate O Rh+ RBC coated by the immunizing antibody and--in some cases--by other anti-D antibodies. Id and cross-reactive id were shown to be located in the antigen-binding and in the non-antigen binding regions of Rh antibodies. An unique example of evolution of idiotypic specificities on human antibodies has been reported. Lastly, we have demonstrated by rosette assay, presence on some PBL of receptors for Fab'2 anti-Rh coating O Rh+ red cells. Rosettes could not be obtained with lymphocytes of a donor and Fab'2 anti-Rh of another individual. Rosettes appeared at a period of time in which the amount of antibody was decreasing.

Agglutination↗
PubMed1984

Idiotypic interrelationship among human myeloma proteins with distinct antibody-binding specificities.

There have been several reports of human myeloma proteins exhibiting autoantibody activity. Such immunoglobulins represent therefore an appropriate system for investigating idiotypic diversity of human autoantibodies. Using this approach, we confirmed the marked idiotypic restriction of polyclonal anti-DNA autoantibodies and we showed that immunoglobulins without known binding affinity may express autoantibody-related idiotopes. These results are discussed in lights of recent concepts upon autoimmune processes and idiotypic interactions.

Antibody Specificity↗
PubMed1984

[Immunological study of a hemophiliac treated according to the Bonn protocol for 2 1/2 years].

A major haemophiliac A, 27 years old, has been treated during 30 months, with high dosage of imported Factor VIII, in order to reduce the titer of a F VIII antibody. A good clinical result has been obtained. No sign of immunodeficiency has been observed. Normal values were obtained for T4/T8, ratio B2 microglobulin and no antibody was detected against the LAV virus isolated from cases of AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1984

IgG subclass distribution of autoantibodies to DNA and to nuclear ribonucleoproteins in autoimmune diseases.

Fifty-seven serum samples positive for antibodies to double-stranded DNA (dsDNA), single-stranded DNA (ssDNA) or small nuclear ribonucleoproteins (snRNP) selected from patients with systemic lupus erythematosus and mixed connective tissue disease, were examined for the IgG subclass distribution of these autoantibodies. It was shown that antibodies to dsDNA were relatively restricted to IgG1 and IgG3 subclasses whilst antibodies to ssDNA were equally distributed throughout the four subclasses. Antibodies to snRNP were essentially restricted to the IgG2 isotype. These isotype distribution patterns contrasted with that observed for total serum IgG.

Antibodies, Antinuclear↗
PubMed1984

[Ciliary activity of cells of the fallopian tubes (apropos of the sequellae of salpingitis)].

A study was made of ciliary movement in tubal epithelium using microphotooscillography on the tubes of 91 patients who were operated on for tubal, ovarian or uterine pathology. Three groups were classified: 31 with healthy tubes, 47 with tubes that showed the consequences of salpingitis. These patients had been operated on for sterility after much treatment with antibiotics and corticoids. 13 sets of tubes from pregnant women (6 cases had intra-uterine pregnancies and underwent tubal ligation after Caesarean section or after a termination of pregnancy) and 7 cases had extra-uterine pregnancies with salpingectomy. This study has made it possible for us to make several observations: The ciliary activity was not altered by the time in the menstrual cycle. When the tubes were healthy tubal activity was hardly changed when a fibroid was present, nor when an ovarian cyst or endometriosis were present (550 beats a minute). In pregnant women ciliary activity is maintained until the pregnancy becomes intra-uterine. It is always abolished in cases of extra-uterine pregnancy, even if this is at some distance from the site of inflammatory reaction caused by implantation of the oocyte. In cases following salpingitis, ciliary activity in the tubes is often altered and sometimes nil. It therefore seems that if one excludes anatomical lesions such as tubal blocks and ampullary phimosis, salpingitis which is the cause of sterility changes tubal physiology greatly. This is true even at some distance from the site of the infective process as is shown by changes in ciliary activity.

Cilia↗