Progesterone: its occurrence in plants and involvement in plant growth.

Progesterone is a mammalian gonadal hormone. In the current study, we identified and quantified progesterone in a range of higher plants by using GC-MS and examined its effects on the vegetative growth of plants. The growth of Arabidopsis (Arabidopsis thaliana) seedlings was promoted by progesterone at low concentrations but suppressed at higher concentrations under both light and dark growth conditions. The growth of the gibberellin-deficient mutant lh of pea (Pisum sativum) was also promoted by progesterone. An earlier study demonstrated that progesterone binds to MEMBRANE STEROID BINDING PROTEIN 1 (MSBP1) of Arabidopsis. In this work, we cloned the homologous genes of Arabidopsis, MSBP2 and STEROID BINDING PROTEIN (SBP), as well as of rice (Oryza sativa), OsMSBP1, OsMSBP2 and OsSBP and examined their expression in plant tissues. All of these genes, except OsMSBP1, were expressed abundantly in plant tissues. The roles of progesterone in plant growth were also discussed.

Hormonal and histological study on irregular genital bleeding in patients with endometriosis during treatment with dienogest, a novel progestational therapeutic agent.

Aim: Dienogest, a novel progestational 19-norsteroid, has been shown to have a therapeutic effect on endometriosis with its major side-effect being irregular genital bleeding. This study aimed to investigate the mechanism responsible for the bleeding seen during dienogest therapy. Methods: For this multicenter, single-dose, open-label study, dienogest at a daily oral dose of 2 mg was administered for 16 weeks to nine patients with endometriosis showing regular menstrual cycles. Weekly determinations of serum endocrine hormone levels during the course of the treatment period and histological endometrial biopsies at the onset of genital bleeding were undertaken. Results: All cases showed genital bleeding irregularly during the treatment period. Endometrial histological findings at the time of presentation of the bleeding revealed a secretory, inert or atrophic appearance of the epithelium, pseudo-decidualization in the stroma, and local hemorrhage around the regions of desquamation of epithelium and lysis in the subepithelial stromal tissue, which are characteristics of breakthrough bleeding known to occur with progestational agents. In contrast, no association with the course of genital bleeding was found with respect to changes in serum estradiol, progesterone, follicle stimulating hormone and luteinizing hormone concentrations, plasma dienogest concentration, endometrial thickness or follicular diameter. Conclusion: These results suggest that the genital bleeding seen in the period of medication with dienogest originated from breakthrough bleeding from the pseudodecidua, which reflects a direct progestational effect of dienogest on the endometrium. (Reprod Med Biol 2007; 6: 223-228).

Blue light-promoted rice leaf bending and unrolling are due to up-regulated brassinosteroid biosynthesis genes accompanied by accumulation of castasterone.

In this study the relationship between blue light- and brassinosteroid-enhanced leaf lamina bending and unrolling in rice was investigated. Twenty-four hours (h) irradiation with white or blue light increased endogenous brassinosteroid levels, especially those of typhasterol and castasterone, in aerial tissues of rice seedlings. There was an accompanying up-regulation of transcript levels of CYP85A1/OsDWARF, encoding an enzyme catalyzing C-6 oxidation, after 6h under either white or blue light. These effects were not observed in seedlings placed under far-red or red light regimes. It was concluded that blue light up-regulates the levels of several cytochrome P450 enzymes including CYP85A1, thereby promoting the synthesis of castasterone, a biologically active brassinosteroid in rice. Based on these findings, it is considered that blue light-mediated rice leaf bending and unrolling are consequences of the enhanced biosynthesis of endogenous castasterone. In contrast to aerial tissues, brassinosteroid synthesis in roots appeared to be negatively regulated by white, blue and red light but positively controlled by far-red light.

Neuromagnetic responses in silence after musical chord sequences.

Neuromagnetic responses in silence after chord sequences ending in three kinds of musical cadences were investigated. The magnetoencephalographic signals of musically trained participants showed clear peaks around the bilateral temporal areas during the period of silence when the cadences were musically premature. Maximum global moment during the silent period was estimated in the auditory cortices. The time course of the source activities revealed two components, first around 80 ms and second around 150 or 200 ms, the latency of which differed depending on the cadence. These auditory cortical activities, particularly the second components, are suggested to reflect the participants' internal generation of a sound image associated with temporal or temporal-spectral expectations induced as a function of musical cadence.