Steroidogenic enzymes in the CP

Peripherally derived steroids affect steroid production in the brain via the blood–brain barrier. However, steroid concentrations are lower in the cerebrospinal fluid than those in the blood, indicating restricted influx of steroids because of their metabolization by choroid plexus (CP) epithelial cells. Here, we analyzed the gene expression of steroidogenic enzymes [cholesterol side-chain cleavage enzyme (P450scc), 17α-hydroxylase/C17-C20 lyase (P450c17), 3β-hydroxysteroid dehydrogenase (3β -HSD), 17β-hydroxysteroid dehydrogenase type 1 (17β -HSD1), aromatase (Cyp19a1), and 5α-reductase type 1 (5α -R1)]. These genes were expressed to a lesser extent in the CP than in the testis and to a similar extent in the cerebral cortex. However, P450scc levels were higher in the CP than in the cerebral cortex, whereas Cyp19a1 levels showed the opposite trend. We also evaluated the effects of orchiectomy and testosterone on the expression of these genes. P450c17 and 5α -R1 levels were unaffected by orchiectomy, whereas P450scc and 3β -HSD levels were increased and decreased, respectively. Cyp19a1 expression increased upon testosterone treatment, whereas that of 17β -HSD decreased upon orchiectomy or administration of testosterone. Immunohistochemistry analysis revealed that 17β -HSD was expressed in the cytoplasm of CP epithelial cells. These results indicate that CP epithelial cells synthesize and convert the certain types of steroids to contribute to the homeostasis of steroids in the brain

ARTIFICIAL BORING ON THE INCISOR ROOT AT THE LATE JOHMON PERIOD

A single hole penetrating tangentially through the middle of the dental root was found in a right central incisor of the mandible. The tooth was excavated from the bottom layer of the late Johmon and early Yayoi periods under the shell mound of Mitani ruin, Tokushima city. The hole is roundly polished to make a cone-like shape on both the mesial and distal sides without crack. There is neither pathological injury nor trace of living response on microscopy and X-ray test. It is strongly suggested that the hole was simply made on the tooth after extraction from the human mandible

キュウキュウ ニオケル ステロイド ゴウセイ コウソ ノ キョクザイ

Neurosteroids are synthesized through mechanism at least partly independent of the peripheral steroidogenic glands, and their neurobiological actions seem to depend on the specific functions of various brain regions. However, little is known about neurosteroids function corresponding to specific structure and functions of the brain regions. Thus the present study analyzed localization of steroid-synthesizing enzymes in the rat and mouse olfactory bulb. RT-PCR and Western-blotting indicated the possible presence of almost all enzymes of steroid synthesis from cholesterol to estradiol, that is, cholesterol side chain cleavage enzyme (P450scc : cholesterol→pregnenolone), 3β-hydroxysteroid dehydrogenase/Δ5 - 4 isomerase (3β-HSD : pregnenolone→progesterone), 17α-hydroxylase/C17-C20lyase (P450c17 : progesterone→ androstenedione), 17β-hydroxysteroid dehydrogenase (17β-HSD : androstenedione→testosterone), 5α-reductase (5αR:testosterone→5α-dihydrotestosterone), and aromatase (testosterone→ estradiol). Immunohistochemistry confirmed that the 5α-reductase was mainly in glial cells with various immunoreactivity and co-localization pattern, but other enzymes were in bulbar neurons, and at least co-localized in mitral/tufted cells. In addition, so far analyzed, enzymatic activities of P450c17 (a key enzyme in sex steroid synthesis) and 17β-HSD were detected biochemically. These enzyme expression and activities were influenced under exposure of 17β-estradiol with various degrees. These findings indicated the presence of steroid-synthesizing activities, and thus of possible neurosteroid metabolism in the olfactory bulb

Light and electron microscopic immunocytochemistry on the localization of 17α-hydroxylase/C17,20-lyase (P450c17) in the rat placenta

The rat placenta is the primary source of androgens during the second half of pregnancy. Androgens are converted to estrogens in the ovaries and contribute to the maintenance of normal pregnancy. We immunocytochemically characterized the cellular and subcellular localization of cytochrome P450 of 17α-hydroxylase/C 17,20-lyase (P450c17), an enzyme responsible for androgen synthesis, in the rat placenta. We also observed the fine structure of the placenta by electron microscopy. The rat placenta had a different structure from the primate, and contained four zones :labyrinth, basal zone, decidua basalis, and metrial gland. The labyrinth had three trophoblastic layers and fetal endothelium, and P450c17 immunoreactivity was homogeneously localized in the three trophoblastic layers but not in the fetal endothelium. In the basal zone, various types of trophoblasts were observed, and the immunoreaction was localized in small basophilic cells and giant cells. The intensity of staining was heterogeneous among these cells. The decidua basalis showed no immunostaining. Subcellular localization of the enzyme was in the cytoplasm, but not in the nucleus or mitochondria. The present study demonstrated a steroidogenic potency in both the labyrinth and the basal zone, although it was shown only in the basal zone in previous studies

Nerve fibers that were not stained with the non-specific acetylcholinesterase (NsAchE) method, and TRPV1- and IB4-positive nerve fibers in the rat cornea

Previously, we noticed the presence of nerve fiber-like structures in a whole mount preparation of the rat cornea that had not been stained with the non-specific acetylcholinesterase (NsAchE) method. These nerve-like fibers were projected into the central area of the cornea, forming a mesh-like pattern. The aim of this study is to examine the properties of these mesh-like fibers using the following two methods : their sensitivity to capsaicin and the detection of isolectin B4 (IB4)- and capsaicin receptor TRPV1 (transient receptor potential vanilloid 1)-reactivities. The mean disappeared area of non-stained fibers after NsAchE treatment was 26% of the total areas in the neonatally capsaicin-treated cornea. Bunches composed of fine IB4-positive nerve fibers were seen in a whole mount preparation. There were connections between the bunches, producing a mesh-like pattern similar to that of the fibers that were not stained with NsAchE. Fine TRPV1-immunoreactive (ir) nerve fibers were also shown to form bunches, with connections between each bunch observed in whole mount preparations. Thus, TRPV1-ir nerve fibers seem to densely innervate the rat corneal subepithelial stroma and are distinct from the NsAchE-positive nerve fibers. The TRPV1-ir fine nerve fibers overlapped with the IB4-positive nerve fibers, suggesting that the mesh-like fibers that were not stained with NsAchE are fine nociceptive sensory nerve fibers because of their sensitivity to capsaicin and similar distribution pattern to IB4- and TRPV1-positive nerve fibers

The ASTRO-H X-ray Observatory

The joint JAXA/NASA ASTRO-H mission is the sixth in a series of highly successful X-ray missions initiated by the Institute of Space and Astronautical Science (ISAS). ASTRO-H will investigate the physics of the high-energy universe via a suite of four instruments, covering a very wide energy range, from 0.3 keV to 600 keV. These instruments include a high-resolution, high-throughput spectrometer sensitive over 0.3-2 keV with high spectral resolution of Delta E < 7 eV, enabled by a micro-calorimeter array located in the focal plane of thin-foil X-ray optics; hard X-ray imaging spectrometers covering 5-80 keV, located in the focal plane of multilayer-coated, focusing hard X-ray mirrors; a wide-field imaging spectrometer sensitive over 0.4-12 keV, with an X-ray CCD camera in the focal plane of a soft X-ray telescope; and a non-focusing Compton-camera type soft gamma-ray detector, sensitive in the 40-600 keV band. The simultaneous broad bandpass, coupled with high spectral resolution, will enable the pursuit of a wide variety of important science themes.Comment: 22 pages, 17 figures, Proceedings of the SPIE Astronomical Instrumentation "Space Telescopes and Instrumentation 2012: Ultraviolet to Gamma Ray

Hitomi (ASTRO-H) X-ray Astronomy Satellite

The Hitomi (ASTRO-H) mission is the sixth Japanese x-ray astronomy satellite developed by a large international collaboration, including Japan, USA, Canada, and Europe. The mission aimed to provide the highest energy resolution ever achieved at E  >  2  keV, using a microcalorimeter instrument, and to cover a wide energy range spanning four decades in energy from soft x-rays to gamma rays. After a successful launch on February 17, 2016, the spacecraft lost its function on March 26, 2016, but the commissioning phase for about a month provided valuable information on the onboard instruments and the spacecraft system, including astrophysical results obtained from first light observations. The paper describes the Hitomi (ASTRO-H) mission, its capabilities, the initial operation, and the instruments/spacecraft performances confirmed during the commissioning operations for about a month