Chemical synthesis and immunological properties of a cyclic eicosapeptide (Gly88,90) 82-101 of the beta subunit of human chorionic gonadotrophin.

The eicosapeptide (Gly88,90) 82-101 hCG-beta was synthesized by the fragment condensation of the nonapeptide (Gly88,90) 82-90 and the undecapeptide 91-101 followed by iodine oxidation to make the disulfide loop. Intramolecularity of the disulfide linking cysteines at 93 and 100 was confirmed. Antipeptide antibodies were elicited in rabbits upon immunization with a conjugate of the peptide with tetanus toxoid.

A dot enzyme immunoassay for detection of IgM antibodies against phenolic glycolipid-I in sera from leprosy patients.

A visual dipstick dot enzyme immunoassay (EIA) for diagnosis of leprosy is described. The assay is based on detection of IgM antibodies against phenolic glycolipid (PGL-I) in sera from leprosy patients. The antigen (PGL-I or synthetic disaccharide of PGL-I) was dotted on a nitrocellulose pad stuck on a plastic strip (dipstick).

Lack of Mycobacterium leprae-specific uptake in Schwann cells.

Among mycobacteria, Mycobacterium leprae have a unique property to infect peripheral nerves, which is the cause of a variety of debilities seen in leprosy. The possibility of selective uptake of M. leprae by Schwann cells was studied using a rat Schwannoma cell line 33B and rat sciatic nerve-derived Schwann cells.

Pregnancy interfering action of LHRH and anti-LHRH.

Until recently LHRH was believed to be a product of the hypothalamic origin whose primary function was to regulate the secretion of gonadotropin from the pituitary. In the last few years, a large body of experimental evidence has emerged for the existence of the releasing hormone at extrahypothalamic sites. The placenta is one such organ in which the hormone is made and probably has a role in stimulation of the secretion of chorionic gonadotropin as suggested by both in vivo and in vitro experiments.

The dominant role of amide group at C-terminus for recognition by antibody in primates against gonadotropin releasing hormone.

A monkey and a baboon immunized with GnRH-tetanus toxoid conjugate developed high anti-GnRH antibody titres which resulted in disruption of cyclicity and low estradiol and progesterone levels indicative of the inhibition of follicular development and ovulation. Sera of both animals reacted with GnRH(NH2) but were devoid of reactivity with peptide sequences, 4-6, 7-10 and 4-10 of GnRH as well as GnRH free acid. Both sera were however reactive with GnRH-Lys-muramyl dipeptide analogue and GnRH-Ala-Ala-Thr-Lys-Pro-Arg-OH.

Immunobiology of gonadotropin-releasing hormone.

This article will review methods successful in inducing antibody responses against gonadotropin releasing hormone without the use of Freund's complete adjuvant (FCA), the characteristics of the antibodies produced, and will describe the dominant antigenic determinant(s) of the decapeptide and the use of monoclonal antibodies for suppression of estrus and of sex steroid production. The potential application of such immunological approaches in veterinary species, in management of precocious puberty in humans, and in hormone dependent cancers, is indicated.

Solid-phase sandwich enzyme immunoassays of human chorionic gonadotropin using monoclonal antibodies.

A two-site sandwich enzyme immunoassay for human chorionic gonadotropin (hCG) employing monoclonal antibodies directed against beta- and alpha-subunits is described. Monoclonal anti-beta-hCG antibody was used for coating microtitration plates and monoclonal anti-alpha-hCG antibody labelled with 1 of the 3 enzymes namely horseradish peroxidase, alkaline phosphatase or beta-galactosidase was used as tracer. The assay is able to detect up to 1 ng hCG/ml.

A dot enzyme-linked immunosorbent assay for detection of antibodies against Entamoeba histolytica.

A visual micro-dot enzyme-linked immunosorbent assay (ELISA) based on detection of antibodies against soluble antigens of axenically grown cultures of Entamoeba histolytica is described. The antigen was spotted on a nitrocellulose sheet, the unsaturated sites blocked with bovine serum albumin (BSA) and incubated with 3-fold dilutions of patient sera followed by incubation with protein A conjugated to peroxidase. Enzymic activity was evidenced using the substrate 4-chloro-1-naphthol.

Sandwich enzyme immunoassay of human chorionic gonadotropin using polystyrene beads as solid support.

A solid-phase sandwich enzyme immunoassay for human chorionic gonadotropin (hCG) employing monoclonal antibodies directed against beta- and alpha-subunits is described. Polystyrene beads used as solid support were coated with monoclonal anti-beta-hCG antibody. Monoclonal anti-alpha-hCG antibody was labelled with the enzyme, horseradish peroxidase.

Solid-phase competitive and sandwich-type erythro-immunoassays for human chorionic gonadotropin.

A simple '1-step' competitive erythro-immunoassay for human chorionic gonadotropin (hCG) employing V-shaped well microtitration plates coated with monoclonal anti-beta-hCG antibody has been described. hCG of the test sample competes with the antigen-coupled sheep erythrocytes for binding to the antibody on the solid surface. The assay is able to detect up to 31.

Characteristics and bioefficacy of monoclonal antigonadotropin releasing hormone antibody.

Mouse hybrid cell clones secreting antigonadotropin releasing hormone monoclonal antibody were developed by fusion of SP2/O-Ag 1.4 myeloma cells with splenocytes of mouse immunized with gonadotropin releasing hormone (GnRH) tagged to tetanus toxoid. The product of hybrid cell clones obtained as ascites fluid from mouse peritoneal cavity had a titre of 10(6) (30-40% binding of 125I-GnRH) in radioimmunoassay.

Bioeffective monoclonal antibody against the decapeptide gonadotropin-releasing hormone: reacting determinant and action on ovulation and estrus suppression.

A monoclonal antibody generated against the decapeptide gonadotropin-releasing hormone (GnRH) was effective in intercepting the bioactivity of the hormone; it blocked ovulation in rats. The antibody reacted optimally with the native hormone. Substitution of amide at the COOH terminus by a carboxyl group decreased immunoreactivity by a factor of 200.

Characterization of antibodies to a placenta-specific antigen cross-reacting with a choriocarcinoma cell line.

Antibodies were raised in rabbits to purified human term placental villous plasma membrane. These were cytotoxic to human peripheral blood lymphocytes and manifested cross-reactivity to kidney and liver. After absorption with these tissues, reactivity was retained with placental villous plasma membrane.

Effects on pregnancy in mice of passive immunization against ovine LH and human chorionic gonadotrophin.

Mice given daily i.p. injections of immunoglobulins against ovine LH on Days 3-7 of pregnancy were devoid of implantation sites on Day 8 whereas mice treated with antibodies to hCG had embryos of normal number and appearance on Day 8.

Autoantibodies to zona pellucida in tubectomized women.

khe study was conducted to detect autoantibodies to zona pellucida by indirect immunofluorescence technique. A total of 60 human sera was examined, which included 15 tubectomized , 15 pregnant, 15 nonpregnant fertile women, and 15 fertile men. In the unabsorbed sera, anti-zona activity was observed in 53.

Paradoxical effect of antibodies against chorionic gonadotropin on BeWo choriocarcinoma cells in vitro and in vivo: evidence for heterogeneity of cell types.

Antisera raised in monkey or baboon against purified beta-subunit of human chorionic gonadotropin (beta-hCG) coupled to tetanus toxoid exert complement-dependent cytotoxic effects on BeWo choriocarcinoma cells maintained in tissue culture. The cytotoxic effect is manifested morphologically as well as by incorporation of radioactive thymidine and leucine. However, in the presence of saturating amounts of anti-beta-hCG antibodies and complement, antibodies failed to kill all of the BeWo choriocarcinoma cells.