Ultra-high-purity iron is a novel and very compatible biomaterial

Metals and alloys are used widely in bone prosthetic materials, stents and dental tissue reconstructions. The most common materials are stainless steels and cobalt-chromium-nickel and titanium alloys. These alloys can be easily deformed but are hard to break. However, their affinity for cells and tissues is very low. In addition, they can sometimes provoke unexpected metal allergies. Iron is an abundant trace element essential for humans. However, excess amounts in particular of Fe2+ ions are toxic. We previously succeeded in obtaining 99.9996% ultra-high-purity iron (ABIKO iron). The chemical properties of ABIKO iron are completely different from that of conventional pure iron. For example, the reaction rate in hydrochloric acid is very slow and there is barely any corrosion. Here, we found that, in the absence of any type of coating, mammalian cells could easily attach to, and normally proliferate and differentiate on, ABIKO iron. On the other hand, cell densities and proliferation rate of the surfaces of plates made from Co–Cr–Mo or Ti–6Al–4V were significantly reduced. In addition, several stress and iron response genes, HSP70, SOD1, ATM and IRP2 did not change in the cells on ABIKO iron, while these genes were induced with exogenous application of FeSO4. Cells also secreted and fastened some organics on ABIKO iron. In vitro collagen binding assay showed that ABIKO iron binds higher amount of collagens. These findings highlight ABIKO iron as a novel biocompatible prosthetic material

A Case of Multicentric Castleman's Disease Having Lung Lesion Successfully Treated with Humanized Anti-interleukin-6 Receptor Antibody, Tocilizumab

This report presents the case of a patient demonstrating multicentric Castleman's disease (MCD) with a lung lesion that was successfully treated with an anti-interleukin-6 receptor antibody, tocilizumab in combination with corticosteroid and tacrolimus. A 43-yr-old female with abnormal shadows on a chest X-ray was referred to the hospital for further examination. She was diagnosed as having MCD based on the characteristic pathology of inguinal lymph node, lung lesions, laboratory data, and undifferentiated arthritis. Corticosteroid and rituximab therapy did not fully ameliorate the symptoms; thus, the therapeutic regimen was changed to include tocilizumab, oral corticosteroid and tacrolimus. This regimen resulted in clinical remission and the dose of tocilizumab and corticosteroid could be tapered. Tocilizumab in combination with corticosteroid and tacrolimus may therefore be a beneficial treatment regimen for lung lesions associated with MCD

Evidence for a companion to BM Gem, a silicate carbon star

Balmer and Paschen continuum emission as well as Balmer series lines of P Cygni-type profile from H_gamma through H_23 are revealed in the violet spectra of BM Gem, a carbon star associated with an oxygen-rich circumstellar shell (`silicate carbon star') observed with the high dispersion spectrograph (HDS) on the Subaru telescope. The blue-shifted absorption in the Balmer lines indicates the presence of an outflow, the line of sight velocity of which is at least 400 km s^-1, which is the highest outflow velocity observed to date in a carbon star. We argue that the observed unusual features in BM Gem are strong evidence for the presence of a companion, which should form an accretion disk that gives rise to both an ionized gas region and a high velocity, variable outflow. The estimated luminosity of ~0.2 (0.03-0.6) L_sun for the ionized gas can be maintained by a mass accretion rate to a dwarf companion of ~10^-8 M_sun yr^-1, while ~10^-10 M_sun yr^-1 is sufficient for accretion to a white dwarf companion. These accretion rates are feasible for some detached binary configurations on the basis of the Bond-Hoyle type accretion process. We concluded that the carbon star BM Gem is in a detached binary system with a companion of low mass and low luminosity. However, we are unable to determine whether this companion object is a dwarf or a white dwarf. The upper limits for binary separation are 210 AU and 930 AU for a dwarf and a white dwarf, respectively. We also note that the observed features of BM Gem mimic those of Mira (omi Cet), which may suggest actual similarities in their binary configurations and circumstellar structures.Comment: 11 pages, 2 figures, 1 table, accepted for publication in Ap

亜鉛欠乏がラット肝薬物代謝酵素に及ぼす影響

Zinc is an essential trace element that plays many important biological roles in the body. In clinical cases and experimental animals, zinc deficiency results in several unfavorable features including growth retardation, hypogonadism, rough skin, and general lethargy. Regarding drug-metabolizing enzymes, there have only been reports that zinc deficiency reduced the content of mRNA and protein of male-specific CYP3A2, CYP3A18 and CYP2C11, and increased the mRNA levels of female-specific CYP2C12 and CYP3A9. We investigated the effects of zinc deficiency on alcohol dehydrogenase (ADH), hydroxysteroid dehydrogenase (HSD) and cytochrome P450s in rats. Cytosolic ADH1 activity was lower in male rats than in female rats. The lower ADH1 activity in male rats was increased to the level of that in female rats by zinc deficiency. Microsomal 20β-HSD activity was detected at a high rate in male rats but was under the limit of quantification (LOQ) in female rats. The high 20β-HSD activity in male rats was decreased to below the LOQ by zinc deficiency. 7-Ethoxycoumarin O-deethylase activity was inhibited by chloramphenicol in female zinc deficiency rats, but not in female control rats and male rats, indicating the induction of CYP2B1 by zinc deficiency in female rats. The mechanisms of changes in enzyme activity in male rats will be discussed based on the impaired testosterone-hypothalamus-pituitary axis originated from hypogonadism caused by zinc deficiency. The mechanisms of CYP2B1 induction in female rats are still unknown