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At least 865 records · Page 48Linked to original sources
PubMed1991

Use of sperm viability and acrosomal status assays in combination with immunofluorescence technique to ascertain surface expression of sperm antigens.

Sperm antigens are being sought for the development of prototype contraceptive vaccines. For vaccine-induced antisperm antibodies to inhibit the function of viable sperm, target antigens must be expressed on the sperm surface before, during or after the acrosome reaction. The purpose of this study was to develop an approach to detect accurately surface binding of antibodies to viable acrosome-intact or acrosome-reacted sperm, and to confirm sperm surface binding characteristics of a panel of antisperm monoclonal antibodies submitted to the World Health Organization Antifertility Vaccines Task Force. Monoclonal antibodies were tested using a combination of carboxyl-fluorescein diacetate (CoFDA) sperm viability, and rhodamine immunofluorescence assays to ascertain surface binding to viable membrane-intact human sperm, and, in parallel studies, with a combination of fluorescein isothiocyanate (FITC) conjugated Pisum sativum agglutinin (PSA) and rhodamine immunofluorescence assays to ascertain the acrosomal status of antibody-positive sperm. Only 14 out of 32 antibodies that were previously considered to be surface-reactive were confirmed to be positive with these methods. Five were positive on unfixed viable (CoFDA-labelled) fresh sperm in this study, and 9 different antibodies were positive on unfixed acrosome-reacted sperm. We conclude that this multifaceted approach is more accurate and informative than previous techniques used for detection of sperm surface antigens such as radioimmunoassay, standard immunofluorescence, sperm agglutination assays and enzyme-linked immunosorbent assays, which can give false positive results due to the presence of contaminating non-sperm cells, insoluble seminal plasma material, or permeabilized non-viable sperm. Furthermore, the combination of assays employed in this study does not depend on sperm motility, as do the immunobead and sperm immobilization assays, and provides information about the acrosomal status of antibody-positive cells.

Acrosome↗
PubMed1981

Reversal of vasectomy: the effects of sperm antibodies on subsequent fertility.

Antisperm antibodies were measured in serum and seminal plasma in 130 males before and after vasectomy reversal and the occurrence of pregnancy was analysed in the partners of 77 who were followed for more than one year. Sperm-agglutinating antibodies were found in the serum of 79% of patients; seminal plasma antibodies were present in only 9.5% before reversal and this rose to 26% afterwards. Pregnancies occurred in the partners of 53% of those men who were trying to produce children. A pregnancy was significantly less likely when the pre-operative serum antisperm antibody titre was 512 or more, but no decrease in fertility was seen with titres below this. Several pregnancies were produced by patients with seminal plasma antibodies, but numbers and follow-up are too small to permit detailed analysis. A randomised controlled trial of per-operative steroids showed that they produced no benefit. The antisperm antibodies associated with vasectomy reversal appear to differ fundamentally from those occurring in naturally subfertile males.

Agglutination Tests↗
PubMed1992

Future perspectives for vaccine development.

The successful development of an anti-fertility vaccine necessitates overcoming obstacles in eliciting an immune response to self species body constituents. The feasibility of accomplishing this task has been demonstrated for certain antigens described in this workshop; however, additional vaccine candidate antigens may yet be revealed from the application of recent advances in molecular biology. Improvements in vaccine design are likely to occur from discovery of more appropriate epitopes on targeting antigens, new carrier molecules for terminating immunological tolerance, expression of vaccine antigens in suitable live vectors, the co-immunization with more than one antigen, the use of safer and/or more effective adjuvants and vehicles, more efficient immunization by targeting antigens to specific lymphoid cells, and the development of superior vaccine delivery systems. Research directed to restricting the immune response to the genital tract and to intentionally reverse the effects of immunization will likely be pursued in the future. All of these areas need to be addressed if vaccines are to be developed that are not only safe and effective but also highly acceptable as birth control methods.

Animals↗
PubMed1991

Accelerated intracranial occlusive disease, oral contraceptives, and cigarette use.

We report clinical and angiographic features of accelerated intracranial occlusive disease resembling moyamoya vasculopathy in five young women who used oral contraceptives (OCs) and smoked cigarettes, but generally had no other obvious risk factors for cerebrovascular disease. Three women had been on OCs for at least 4 years, one woman each had been on OCs for 3 months and for 2 weeks. All five women had smoked cigarettes for at least eight pack-years. Intermittent and progressive multifocal cognitive, visual, motor, or sensory hemispheric symptoms and signs developed in all. All patients developed strokes, four preceded by transient ischemic attacks. Cerebral angiography demonstrated bilateral supraclinoid internal carotid artery stenosis in four patients and proximal posterior cerebral artery stenosis in one. Additional features included rete mirabile, telangiectasias, prominent lenticulostriate collaterals, and multifocal distal cerebral branch occlusions. Three had mild abnormalities of serum fibrinogen, antinuclear antibody, erythrocyte sedimentation rate, or CSF IgG. After discontinuing OCs and reducing cigarette use, four women have not had further strokes over a mean follow-up of approximately 5 years. In certain young women, clinical and angiographic features resembling moyamoya may develop with the use of OCs and cigarettes. We speculate that an immunologically mediated vasculopathy may explain, in part, this unusual cerebrovascular syndrome in otherwise healthy young women.

Adult↗
PubMed1983

Properties of the phosphorylated beta subunit of human choriogonadotropin.

The beta subunit of human choriogonadotropin (hCG) was previously shown to be phosphorylated by beef skeletal muscle cAMP-dependent protein kinase (Keutmann, H. T., Ratanabanangkoon, K., Pierce, M. W., Kitzmann, K., and Ryan, R. J. (1983) J. Biol. Chem. 258, 14522-14527). The phosphorylation site was primarily at Thr 97, located within the "determinant loop" region proposed by Ward and Moore (Ward, D. N., and Moore, W. T. (1979) Animal Models for Research in Fertility and Contraception (Alexander, N. J., ed) pp. 151-164, Harper and Row, Baltimore, MD) to be important for hormonal activity and specificity. Biological and immunological studies were carried out to determine the effect of this modification on the activity of hCG. The phosphorylated hCG beta recombined with hCG alpha to form phosphorylated hCG (*hCG). The recombined *hCG retained full immunological activity in a radioimmunoassay using anti-hCG serum and 125I-hCG. The biological activities of the *hCG on appropriate rat gonadal cells, as studied by hCG radioreceptor assay, follitropin radioreceptor assay, and adenylate cyclase assay, were 0.29 +/- 0.04, 0.29 +/- 0.07, and 0.69 +/- 0.13 times as potent as hCG, respectively. The reduced receptor binding activity of *hCG was not due to dissociation of the hormone into its subunits. The far ultraviolet CD spectrum of the *hCG showed no gross conformational change induced by phosphorylation. We conclude the following: 1) Thr 97 is not involved in subunit-subunit interaction and is not part of the hCG antigenic site recognized by this particular antiserum; 2) Thr 97 does appear to participate in the hCG-receptor interactions; 3) modification of Thr 97 does not result in an enhancement of follitropin-like activity.

Adenylyl Cyclases↗
PubMedDate not supplied

[Hyperhomocysteinemia-related cerebral venous thrombosis].

INTRODUCTION: Moderate hyperhomocysteinemia is a causal risk factor for atherosclerosis and venous thromboembolism. Recent researches have tried to find out a causal relationship. However, only a small number of cases have been reported on hyperhomocysteinemia and cerebral venous thrombosis in the world medical literature. CASE REPORT: We present the case of a 21 years old woman, and oral contraceptives taker, who consulted for a one week clinical picture of biparietal headache, nausea and vomiting. Examination revealed bilateral papilledema, and subsequent CT scan, MRI and MR angiography showed thrombosis of the left lateral sinus. Immunologic tests (antinuclear antibodies, antiphospholipid antibodies) were negative. Hypercoagulability studies showed persistent homocysteine high levels. The patient improved and was discharged after treatment with anticoagulants and therapeutic measures against brain edema. DISCUSSION: The 70 percent of the patients with thrombosis of the cerebral venous sinuses present hypercoagulable states, including moderate hyperhomocysteinemia. Several mechanisms are proposed for venous thrombosis in hyperhomocysteinemia, homocysteine induced endothelial dysfunction between others. Otherwise, oral contraceptives can increase the risk of venous thrombosis in other prothrombotic conditions. Folic acid and vitamins supplementation therapy are commented.

Adult↗
PubMed1991

The association between pregnancy and human papilloma virus prevalence.

This study examined the effects of pregnancy on the prevalence of HPV infection, comparing 69 pregnant and 54 nonpregnant age-frequency matched female patients. HPV prevalence was detected by DNA hybridization using the ViraPap/ViraType dot blot procedure. The prevalence of HPV among pregnant women increased with gestational age from 8.0% in the first trimester, to 16.7% in the second, and 23.1% in the third trimester. This finding suggests that HPV infection may be activated by hormonal or other effects of pregnancy and may explain why number of pregnancies is known to be associated with increased risk of cervical dysplasia and cancer. Oncogenic HPV types 16/18 and 31/33/35 were identified with almost equal frequency in the study population whereas HPV 6/11 was seen rarely. The logistic regression models indicate that there were no significant differences between HPV positive and HPV negative groups by age, income, number of sex partners, age of first intercourse, average frequency of intercourse per month, number of pregnancies, oral contraceptive duration, or pregnancy status. There were no interaction effects. A current Pap result of cervical dysplasia (OR = 8.9; 95% confidence interval: 2.1, 38.8), oral contraceptive use (OR = 0.1; 0.03, 0.6), and education (OR = 1.4; 1.1, 1.8) were significant predictors of HPV status.

Adolescent↗
PubMed1981

The results of intermittent high dose steroid therapy for male infertility due to antisperm antibodies.

Forty-five males who had been infertile for 2 to 10 (average 5.3) years, with significantly positive antisperm antibody tests (serum spermagglutination titers more than 32) and demonstrably improved sperm penetration of cervical mucus, were treated with repeated 7-day courses of methylprednisolone (MP) 32 mg three times a day from days 21 to 28 (in a few cases days 1 to 7) of their wives' menstrual cycles. Antisperm antibody tests were repeated after treatment and related to the occurrence of pregnancy in the wife. Fourteen wives (31%) became pregnant in a cycle following treatment of the husband. The production of pregnancy was always associated with a marked drop in sperm immobilizing titer and usually with disappearance of antibodies from seminal plasma; both of these effects were sometimes observed without a significant change in serum spermagglutination titers. Three patients (6%) had transient severe side effects, and 14 (26%) have had mild side effects, out of 54 patients treated so far.

Adult↗
PubMed1996

Characterisation of a sperm coating auto-antigen reacting with antisperm antibodies of infertile males using monoclonal antibodies.

OBJECTIVE: In a previous study a number of sperm-specific antigens were identified which reacted with antisperm antibodies from both infertile and vasovasostomised males. To investigate the localisation and distribution of these antigens and their role in male fertility, monoclonal antibodies were raised against them; immunoblotting techniques were used to select only those antibodies which competed with human antisperm antibodies for these human auto-antigens. DESIGN: One antibody, NW21, reacted with an 18 kDa auto-antigen present on epididymal sperm but absent from testicular sperm. Immunohistochemical studies showed that the antigen is produced in small basal cells between the columnar epithelium of the corpus epididymis, passes up into the tubule and then coats sperm passing along the epididymis. Sperm stored in the cauda epididymis and ductus deferens stain strongly for this sperm coating glycoprotein. CONCLUSIONS: The localisation of this antigen supports the suggestion that auto-immune infertility may represent a response to epididymal rather than testicular sperm. Monoclonal antibodies raised to unique and immunologically accessible sperm coating proteins, produced in the epididymis rather than in the testis, would seem to present an excellent theoretical solution to male contraception.

Aged↗
PubMed1976

[Immunological dtermination of at. III (author's transl)].

We have effectuated immunologically determination of At. III in serum and plasma into two groups of patients: 1) constituted of 10 subjects which never take oral hormone contraceptives; 2) constituted of 22 subjects who are taking OHC; for various time period. The results indicating that a difference exist between serum and plasma At. III concentration, ad this difference reaches to 30%. In this series of data the At. III levels was normals.

Adult↗
PubMedDate not supplied

[A preclinical study of the embryotoxic properties of cucumarioside and its effect on adult generative function].

The preclinical study of embryotoxicity of a new immunomodulator cucumariosid was carried out. Cucumariosid at long-term use exerts no effect on the generative function of rats, the general condition of pregnant females and the postnatal development of the offspring, possesses no teratogenic action. The use of the drug in the preimplantation period of pregnancy and the implantation period produces the contraceptive effect.

Abnormalities, Drug-Induced↗