Immunophotoaffinity labeling of binders of 1-methyladenine, the oocyte maturation-inducing hormone of starfish.

Starfish oocytes are arrested at the prophase stage of the first meiotic division in the ovary and resume meiosis by the stimulus of 1-methyladenine (1-MeAde), the oocyte maturation-inducing hormone of starfish. Putative 1-MeAde receptors on the oocyte surface have been suggested, but not yet been biochemically characterized. Immunophotoaffinity labeling, i.e., photoaffinity labeling combined with immunochemical detection, was attempted to detect unknown 1-MeAde binders including putative maturation-inducing hormone receptors in starfish oocytes. When the oocyte crude membrane fraction or its Triton X-100/EDTA extract was incubated with N6-[6-(5-azido-2-nitrobenzoyl)aminohexyl]carboxamidomethyl-1-methyladenine and then photo-irradiated, followed by western blotting with antibody that was raised against a 1-MeAde hapten, a single band with Mr of 47.5 K was detected. The band was lost when extract was heated at 100 °C. A similar 47.5 K band was detected in the crude membrane fraction of testis as well. Upon labeling with whole cells, this band was detected in immature and maturing oocytes, but only faintly in mature oocytes. As judged from these results, this 1-MeAde binder might be a possible candidate of the starfish maturation-inducing hormone receptors.

Immunophotoaffinity labeling of the binding proteins for 1-methyladenine, an oocyte maturation-inducing hormone of starfish.

Starfish oocytes are naturally arrested at the prophase stage of the first meiotic division and resume meiosis in response to 1-methyladenine (1-MeAde), the oocyte maturation-inducing hormone of starfish. Putative receptors for 1-MeAde have not yet been characterized biochemically, although the specific binding of 1-MeAde to the isolated cortices of starfish oocytes was reported so far. Based on the structure-activity relationship of 1-MeAde analogs, we have designed a photoaffinity labeling reagent. The photoaffinity labeling of oocyte membrane fractions, followed by immunoblotting analysis with anti-1-MeAde antibody, results in the detection of an almost single protein band. This 1-MeAde-binding protein might be a possible candidate of the maturation-inducing hormone receptor of starfish.

Urinary calreticulin in the diagnosis of bladder urothelial carcinoma.

OBJECTIVES: To evaluate the potential suitability of calreticulin (CRT) as a urinary marker for bladder cancer. METHODS: Urine specimens were collected from patients with histologically confirmed bladder urothelial carcinoma (Group 1; n = 109), urological patients without urothelial carcinoma (Group 2; n = 60), and non-urological patients (Group 3; n = 40). We developed an enzyme-linked immunosorbent assay (ELISA) procedure using commercially available anti-CRT mono/polyclonal antibodies, and then measured the concentration of urinary CRT. RESULTS: Urinary CRT concentration of group 1 was significantly higher than group 2 and 3 (Mann-Whitney U-test, P < 0.001). Groups 2 and 3 were joined together and considered as a non-bladder cancer group (n = 100), and a cutoff value (2.85 ng/mL) was determined using receiver operating characteristic (ROC) analysis. The sensitivity, specificity, and the area under the curve were 67.9%, 80.0%, and 0.742, respectively. The overall sensitivity of voided urine cytology (VUC) was 39.0% (n = 105), and the sensitivity of urinary CRT was significantly superior to VUC (McNemar test, P < 0.001). Higher sensitivity was observed especially in Ta, G1-2, and

Determination of procalcitonin concentration using the SphereLight 180 clinical auto-analyzer.

BACKGROUND: Procalcitonin (PCT) is a biomarker for the diagnosis of sepsis and bacterial infection diseases. METHODS: A new fully automated SphereLight PCT (SL-PCT) assay system for PCT concentration in human serum or plasma by using SphereLight 180 (SL180, Olympus Corp.) analyzer was developed. The SL-PCT assay is based on chemiluminescent enzyme immunoassay. RESULTS: A linear dose response relationship was observed up to 200 ng/ml PCT concentration. The detection limit of PCT concentration was 0.06 ng/ml. Endogenous substances, anticoagulants, sodium fluoride and drugs did not interfere with assay results. There was a good correlation between the present method and the manual method in serum and plasma samples. CONCLUSIONS: These results indicate that the SL-PCT assay showed good performance in terms of the linearity, detection limit and precision. Use of this PCT measurement may improve the detection of sepsis and infectious disease.