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F Saji

Publications and source records attributed to F Saji.

At least 145 records · Page 8Linked to original sources
PubMed1988

Clinical evaluation of the enzyme-linked immunosorbent assay (ELISA) kit for antisperm antibodies.

A commercially available enzyme-linked immunosorbent assay (ELISA) kit for the detection of antisperm antibodies in serum was compared with standard sperm immobilization test (SIT) with the use of sera from 83 infertile women and 29 control individuals. For the ELISA, 24% of the infertile patients and 10% of the controls showed positive results, whereas 15% of the patients and none of the control were positive in the SIT. Parallel tests carried out on the same sera indicated that these methods detect a different, though often overlapping, spectrum of antibody activity. The presence and number of motile sperm in cervical mucus during postcoital tests were found to be related to the results of the SIT. On the other hand, the ELISA did not appear to be related to the quality of postcoital tests. These data indicate that care must be employed to interpret the results of this ELISA kit for the detection of antisperm antibodies.

Antibodies↗
PubMed1988

Identification and characterization of a human sperm antigen corresponding to sperm-immobilizing antibodies.

A sperm antigen has been isolated from radiolabeled human sperm cell membrane by detergent solubilization, lectin affinity chromatography, gel filtration, and indirect immune precipitation using sperm-immobilizing antisera from patients with unexplained infertility. Isolated material was characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Among 20 infertile women's sera with sperm-immobilizing antibodies, two were found to react predominantly with a sperm membrane polypeptide having the approximate molecular weight of 15,000 daltons. No significant binding to this molecule was observed in any sera from pregnant women, unmarried women, and normal men. By the absorption with spermatozoa, the antisera lost their binding activity to the molecule, while the sera absorbed with seminal plasma did not lose the activity. The results indicated that the molecule is a genuine sperm antigen and not a sperm-coating seminal plasma antigen. By the indirect immunofluorescence of washed ejaculated spermatozoa with the antisera, strong fluorescence was localized only in an equatorial segment of the acrosome, while no specific staining was observed in the controls. The antigen is relatively unstable against acid, alkali, and heat treatment. Treatment with proteolytic enzymes such as pronase and trypsin inactivated the antigen activity, indicating that the antigen epitope could be a peptide portion of the glycoprotein.

Antigens, Surface↗
PubMed1988

[Sperm-immobilizing antibodies in serum, follicular fluid and ascites].

Antisperm antibodies appear to impair reproduction. Follicular fluids, ascites and sera taken at the time of oocyte recovery from patients undergoing gamete intrafallopian transfer (GIFT) were examined for the presence of sperm immobilizing antibodies and their immunoglobulin classes were determined. Three out of ten patients were found to have sperm immobilizing antibodies in their sera. The immunoglobulin classes of the antibodies were IgG and/or IgM, and no IgA class antibodies were detected. The same classes of antibodies found in sera also existed in follicular fluids and ascites in these patients. Furthermore, titers of the antibodies in follicular fluids and ascites were consistent with those of patients' sera.

Adult↗
PubMed1988

[Identification and characterization of a human sperm coating antigen isolated from sperm cell membrane].

An antigenic spermatozoal polypeptide was identified from nonionic detergent solubilized membrane material of sperm cells by using a human seminal plasma specific rabbit antiserum. The radiolabeled sperm cell membrane preparation was subjected to gel filtration and gel fractions were assayed for the binding activity with antiseminal plasma antiserum. The immune complex of the peak fraction of the binding was applied on SDS-PAGE, and the antigen was estimated to be a single polypeptide of approximately 12,000 daltons. The inhibition assay of the binding revealed that the antigen is present in sperm, seminal plasma, and milk, but is absent from any other organs and tissues except male genital tracts. Seminal plasma showed the largest amount of the activity, suggesting that this antigen is a sperm coating antigen. In seminal plasma, the antigen molecule present in a large form with a molecular weight of approximately 50,000 daltons. The antigenicity was stable when treated with heat, acid, alkali and various protein denaturants. The characteristics of the present antigen are very similar to those of lactoferrin and ferrisplan, the other sperm coating antigens common to milk. However, they are quite different in molecular weight, and no cross reactivity was found between the present antigen and lactoferrin or ferrisplan.

Antigens, Surface↗
PubMed1987

Effect of a soluble factor secreted from cultured human trophoblast cells on in vitro lymphocyte reactions.

The immunoregulatory role of trophoblast cells in cell-mediated immunity was investigated. Trophoblast cells were obtained from 8-10-week human placentae by treatment with collagenase followed by differential centrifugation. The cells were cultured for 48 hr, and the culture supernatant was examined for immunosuppressive activity in vitro. The supernatant when added to cultures of peripheral blood lymphocytes from healthy donors suppressed both their reactivity to different lectins (PHA and PWM) and their activity in one-way mixed lymphocyte reaction. The degree of suppression was dose-dependent. Furthermore, the supernatant was able to reduce the natural killer cell activity against K562 target cells. On the other hand, the supernatant had no inhibitory effect on the effector phase of lymphocyte-mediated cytotoxicity activity against tumor cell lines RPMI 8866 and Daudi. In all cases, the suppression observed was not due to lymphocytotoxicity or tumor cell mortality. The results indicate that trophoblast cells release a soluble suppressive factor that is a potent inhibitor of cell-mediated immunity.

Cytotoxicity, Immunologic↗
PubMed1987

[ELISA for antisperm antibodies in unexplained infertile women].

It is commonly believed that autoimmune or isoimmune responses to human sperm antigens are associated with human infertility. We examined an enzyme linked immunosorbent assay (ELISA) kit used in the detection of antisperm antibodies in the sera of women with unexplained infertility. 1) For the ELISA assay, an absorbance at 405nm greater than 0.300 was considered positive. Of the 83 sera of infertile women studied, 20(24.1%) were positive. This value was significantly higher than that of the control group: 10% of pregnant women, 11.1% of unmarried women and 10% of healthy men (p less than 0.05). 2) The results obtained with ELISA were compared with those of the sperm immobilization test. Comparison of the results of ELISA with those of the sperm immobilization test indicated that these methods detect a different, though often overlapping, spectrum of antibody activity. 3) The results obtained with ELISA did not always correlate with those of the Huhner test. However the ELISA method may be useful in the clinical screening of antisperm antibodies because of its simplicity and rapidity.

Adult↗
PubMed1986

Further characterization of a human sperm coating antigen (gp12).

In our previous paper, we identified a novel sperm-coating antigen with molecular weight of approximately 12,000 daltons that is highly specific to sperm, seminal plasma, and milk from the plasma membrane fraction of human spermatozoa by using rabbit antiseminal plasma antiserum. In the present study, this 12,000-daltons component, termed gp12, has been investigated for its tissue distribution and antigenic stability. The largest amounts of the antigen are found in seminal plasma, although individual variation is rather high. In seminal plasma, the gp12 molecule presents in a large form with a molecular weight of approximately 50,000 daltons. Its antigenicity is stable when treated with acid, alkali, heat, and various protein denaturants.

Antigens, Surface↗
PubMed1986

Immunoregulatory effects of human cord blood T lymphocytes on mixed lymphocyte reaction.

Fetuses of outbred mammalian species can survive despite disparities of participants' histocompatibility antigens. During pregnancy, maternal immune response is supposed to be suppressed by various immune suppressive mechanisms. In order to know whether fetal lymphocytes can suppress the maternal immune reaction, we investigated the suppressive effect of human newborns' T lymphocytes. Newborn T cells were isolated from the umbilical cord blood by means of the sheep red blood cell rosette forming method and treated with mitomycin C. The newborn T cells were added as regulator cells to one way mixed lymphocyte reaction (MLR) using maternal lymphocytes, paternal lymphocytes and unrelated donor's lymphocytes. In a control study, adult T cells were treated in the same manner. In any combination of the MLR, the response was substantially suppressed by the addition of cord T cells in comparison with the response by the addition of normal adult T cells. The suppression was dose-related with an increasing number of regulator cord T cells. The suppressive activity of cord T cells showed radiation resistance until 1,000 rads irradiation. In the kinetics study, cord T cells were found to suppress the recognition phase of MLR. These results suggest that cord T lymphocytes suppress the mother's immunological reaction to the fetal antigens.

Female↗
PubMed1985

A human sperm coating antigen isolated from sperm cell membrane.

A human sperm cell membrane antigen that is highly specific to sperm and seminal plasma was isolated from plasma membrane fraction of spermatozoa using rabbit antiserum against human seminal plasma. In addition to the high specificity to sperm and seminal plasma, the isolated antigen showed the following characteristics: (1) It is a glycoprotein of approximately 12,000 daltons that has an affinity to lentil lectin; (2) it is distributed in human milk other than in sperm and seminal plasma, but is not found in any other organs and tissues including testis; (3) seminal plasma contains the largest amount of the antigen activity, 60-fold greater than spermatozoa and 900-fold greater than milk, suggesting that this antigen could be a sperm-coating seminal plasma antigen.

Antigens↗