A rapid microassay for detecting hepatitis B surface antigen by dot enzyme immunoassay

This study describes a dot enzyme immunoassay (Dot-EIA) for detecting hepatitis B surface antigen (HBsAg). The results demonstrated that the detection level of this assay for HBsAg was 1.5 ng/ml; no false-positive or -negative readings were observed. Also, this Dot-EIA had some advantages over standard EIA: (1) antiserum could be directly and immediately bound on nitrocellulose paper set into microfiltration apparatus, (2) the paper could be easily washed under reduced pressure using a water aspirator, (3) all assay steps could be performed at room temperature within 2 h, (4) the well-defined brown spots could be evaluated by both visual observation and densitometric reading. The Dot-EIA reported here may be useful for rapid diagnosis and screening of HBsAg in serum.     

Physical,behavioral, and hormonal changes in the resumption of sexual receptivity during postpartum infertility in female bonobos at Wamba

Primates - The operational sex ratio (OSR) is used as a predictor for the intensity of mating competition. While many factors affect the OSR, there tends to be a high male bias in primate species...     

Intracellular localization of histone deacetylase HDA6 in plants

Journal of Plant Research - Histone modification is an important epigenetic mechanism in eukaryotes. Histone acetyltransferase and deacetylase regulate histone acetylation levels antagonistically,...     

A new class of pentapeptide KISS1 receptor agonists with hypothalamic–pituitary–gonadal axis activation

The kisspeptin (Kp, Kp-54, metastin)/KISS1R system plays crucial roles in regulating the secretion of gonadotropin-releasing hormone. Continuous administration of nonapeptide Kp analogs caused plasma testosterone depletion, whereas bolus administration caused strong plasma testosterone elevation in male rats. To develop a new class of small peptide drugs, we focused on stepwise N-terminal truncation of Kp analogs and discovered potent pentapeptide analogs. Benzoyl-Phe-azaGly-Leu-Arg(Me)-Trp-NH₂ (16) exhibited high agonist activity for KISS1R and excellent metabolic stability in rat serum. A single injection of a 4-pyridyl analog (19) at the N-terminus of 16 into male Sprague Dawley rats caused a robust increase in plasma luteinizing hormone levels, but unlike continuous administration of nonapeptide Kp analogs, continuous administration of 19 maintained moderate testosterone levels in rats. These results indicated that small peptide drugs can be successfully developed for treating sex hormone deficiency.     

Thrombopoietin/MPL signaling regulates hematopoietic stem cell quiescence and interaction with the osteoblastic niche

Maintenance of hematopoietic stem cells (HSCs) depends on interaction with their niche. Here we show that the long-term (LT)-HSCs expressing the thrombopoietin (THPO) receptor, MPL, are a quiescent population in adult bone marrow (BM) and are closely associated with THPO-producing osteoblastic cells. THPO/MPL signaling upregulated beta1-integrin and cyclin-dependent kinase inhibitors in HSCs. Furthermore, inhibition and stimulation of THPO/MPL pathway by treatments with anti-MPL neutralizing antibody, AMM2, and with THPO showed reciprocal regulation of quiescence of LT-HSC. AMM2 treatment reduced the number of quiescent LT-HSCs and allowed exogenous HSC engraftment without irradiation. By contrast, exogenous THPO transiently increased quiescent HSC population and subsequently induced HSC proliferation in vivo. Altogether, these observations suggest that THPO/MPL signaling plays a critical role of LT-HSC regulation in the osteoblastic niche.