Fluorimetric determination of d-amino acid oxidase

1. A sensitive fluorimetric procedure for the assay of d-amino acid oxidase has been developed. 2. The method depends on the formation of a fluorescent derivative, 2-hydroxy-3-methylquinoxaline, on condensation of pyruvate with o-phenylenediamine in acid medium. 3. 2-Hydroxy-3-methylquinoxaline fluoresces strongly in 50% (v/v) sulphuric acid after excitation at 375mmu. A single emission peak is observed at 480mmu. 4. Formation of the quinoxaline is dependent on time, temperature, acidity and relative concentration of reactants. 5. A particulate preparation from mouse kidney required FAD for optimum activity at pH8.5; K(m) was 3.8x10(-3)m; K(FAD) was 1.4x10(-7)m and the reaction was strongly inhibited by p-chloromercuribenzoate and phenylmercuric acetate. 6. Subcellular fractionation on a sucrose density gradient confirmed that the d-amino acid oxidase was localized on small granules.     

Failure of spermatozoa from T/t mice to fertilize in vitro is overcome by zona drilling

Failure of epididymal spermatozoa from T/t mutant mice, but not from t/t individuals, to fertilize oocytes in vitro was partially overcome by opening a small aperture in the zona pellucida with acidified Tyrode's solution to permit direct access of the spermatozoon to the vitellus. This study provides a model system to evaluate requirements for successful zona drilling in the treatment of human infertility and further insights into the effects of the t complex on sperm fertility.     

Molecular cloning and characterization of complementary deoxyribonucleic acids corresponding to bovine trophoblast protein-1: a comparison with ovine trophoblast protein-1 and bovine interferon-alpha II

Bovine trophoblast protein-1 (bTP-1) is a secreted glycoprotein that consists of several forms differing slightly in mol wt and isoelectric point. It is produced by bovine conceptuses after about day 15 of pregnancy and is believed to play a key role in signalling the presence of an embryo to the mother. In this study, a series of recombinant cDNA clones corresponding to the mRNA for bTP-1 have been isolated from cDNA libraries representing day 18-19 bovine conceptus poly(A)+ mRNA. Base sequencing of several cDNAs indicated that multiple mRNAs for bTP-1 exist. Northern blotting and primer extension experiments showed that the mRNAs average about 1 kilobase in length. One apparently full-length cDNA clone consisted of 1035 bases up to the beginning of the poly(A) tail. It contained an open reading frame of 195 codons which began at a position 79 bases from the 5' end. Its entire sequence was 85% identical to that of a cDNA for the immunologically related ovine trophoblast protein-1 (oTP-1) and about 79% identical to that for a bovine interferon-alpha II (IFN alpha II). The highest conservation of sequence (greater than 90%) was noted in the 3'-untranslated sequences of the bTP-1 and oTP-1 cDNAs. The deduced amino acid sequence of bTP-1 shared 80% identity with oTP-1, between 45-55% with human, rodent, porcine, and bovine IFNs of the alpha 1 subfamily and about 70% with a bovine IFN alpha II. A single potential site for N-glycosylation was noted at Asn78. These results show that bTP-1, like its ovine counterpart oTP-1, is structurally related to the IFN alpha S. We suggest that these embryonic IFNs play a role in controlling immunoreactions at the trophoblast-uterus interface as well as triggering other maternal responses to pregnancy.     

Trial of support treatment with human chorionic gonadotrophin in the luteal phase after treatment with buserelin and human menopausal gonadotrophin in women taking part in an in vitro fertilisation programme.

OBJECTIVE--To evaluate the effect of support with human chorionic gonadotrophin in the luteal phase in women taking part in an in vitro fertilisation programme after buserelin and human menopausal gonadotrophin were used to hyperstimulate their ovaries. DESIGN--Controlled group comparison. SETTING--Outpatient department of a private hospital. PATIENTS--115 Women with indications for in vitro fertilisation, all of whom had at least one embryo transferred. INTERVENTIONS--After suppression of the pituitary with buserelin the ovaries of all the women were stimulated with human menopausal gonadotrophin on day 4 of the luteal phase. Human chorionic gonadotrophin (10,000 IU) was given to induce ovulation, and oocytes were recovered 34 hours later. Embryos were transferred 46 to 48 hours after insemination. Women who had received the 10,000 IU of human chorionic gonadotrophin on a date that was an uneven number (n = 61) were allocated to receive support doses of 2500 IU human chorionic gonadotrophin three and six days after that date. The remaining 54 women did not receive hormonal support. END POINT--Determination of the rates of pregnancy. MEASUREMENTS and main results--Support with human chorionic gonadotrophin did not significantly alter the progesterone or oestradiol concentrations in the early or mid-luteal phase. The mean (range) progesterone concentrations in the late luteal phase in women who did not become pregnant were, however, significantly higher in those who received support (16(9-110) nmol/l nu 8(4-46) nmol/l), and the luteal phase was significantly longer in this group (14 days nu 12 days). The rate of pregnancy was significantly higher in the women who received support than in those who did not (25/61 nu 8/54). CONCLUSIONS--When buserelin and human menopausal gonadotrophin are used to hyperstimulate ovaries support with human chorionic gonadotrophin in the luteal phase has a beneficial effect on in vitro fertilisation.