Non-destructively differentiating the roles of creep, wear and oxidation in long-term in vivo exposed polyethylene cups

Wear of polyethylene acetabular cups in patients of total hip arthroplasty is routinely deduced from the penetration of the femoral head into the acetabular liner as observed in the radiographs. However, the linear penetration thus measured represents the cumulative contribution of two components, one due to wear, and the other due to creep or irreversible deformation of the polyethylene structure. The erroneous attribution to wear of the entire penetration displacement of the head in the cup might lead to misinterpretation of the actual performance of acetabular cups. The aim of this study was to quantify the head displacement components due to wear and to creep, as they occur in vivo in acetabular cups, and to relate them to the oxidation state of the material by means of advanced Raman spectroscopy procedures. Throughout the investigation, we compared the behaviors on the molecular scale of acetabular cups subjected to different sterilization methods (i.e., gamma-irradiation and ethylene oxide treatment). (C) Koninklijke Brill NV, Leiden, 201

Circannual Control of Hibernation by HP Complex in the Brain

SummarySeasonal hibernation in mammals is under a unique adaptation system that protects organisms from various harmful events, such as lowering of body temperature (Tb), during hibernation. However, the precise factors controlling hibernation remain unknown. We have previously demonstrated a decrease in hibernation-specific protein (HP) complex in the blood of chipmunks during hibernation. Here, HP is identified as a candidate hormone for hibernation. In chipmunks kept in constant cold and darkness, HP is regulated by an individual free-running circannual rhythm that correlates with hibernation. The level of HP complex in the brain increases coincident with the onset of hibernation. Such HP regulation proceeds independently of Tb changes in constant warmth, and Tb decreases only when brain HP is increased in the cold. Blocking brain HP activity using an antibody decreases the duration of hibernation. We suggest that HP, a target of endogenously generated circannual rhythm, carries hormonal signals essential for hibernation to the brain

Structured triacylglycerol containing behenic and oleic acids suppresses triacylglycerol absorption and prevents obesity in rats

<p>Abstract</p> <p>Background</p> <p>Dietary 1(3)-behenoyl-2,3(1)-dioleoyl-<it>rac</it>-glycerol (BOO) has been reported to inhibit pancreatic lipase activity <it>in vitro </it>and suppress postprandial hypertriacylglycerolemia in humans. In the present study, the anti-obesity activities of BOO and its inhibitory effects on lymphatic triacylglycerol (TAG) absorption were investigated in rats.</p> <p>Methods</p> <p>In Experiment 1, rats were fed either BOO or soybean oil (SO) diet for 6 weeks. In the BOO diet, 20% of SO was replaced with an experimental oil rich in BOO. In Experiments 2 and 3, rats cannulated in the thoracic duct were administered an emulsions containing trioleoylglycerol (OOO) or an oil mixture (OOO:BOO, 9:1). Tri[1-¹⁴C]oleoylglycerol (¹⁴C-OOO) was added to the emulsions administered in Experiment 3.</p> <p>Results</p> <p>No observable differences were detected in food intake or body weight gain between the BOO and SO groups in Experiment 1. Plasma and liver TAG concentrations and visceral fat weights were significantly lower in the BOO group than in the SO group. The apparent absorption rate of fat was significantly lower in the BOO group than in the SO group. In Experiment 2, the lymphatic recovery of oleic and behenic acids was significantly lower at 5 and 6 h after BOO administration than after OOO administration. In Experiment 3, the lymphatic recovery of ¹⁴C-OOO was significantly lower at 5 and 6 h after BOO administration than after OOO administration.</p> <p>Conclusions</p> <p>These results suggest that BOO prevents deposition of visceral fat and hepatic TAG by lowering and delaying intestinal absorption of TAG.</p

イメージ レインボウ ホログラム ノ サクセイ ト ハクショクコウ ニヨル カラー サイセイガゾウ

A unique characteristic of optical holography is an idea of recording the complete wave field, i. e., the amplitude and the phase of the light waves scattered by an object. Holograms are recorded on a flat photosensitive materials, but produce a three-dimensional image when they are illuminated with monochromatic light or white light. A two-step rainbow holographic process of Benton has done a major improvement in the area of arts and displays. In this study, a simplified technology of image and rainbow type color holograms for displays is reviewed with a practical optical setups, and the characteristics of reconstructed images in color, i. e, visual appearance of color holograms capable of reconstructing a bright, sharp, and chromatic image are discussed when illuminated with white light

Inhibitory Role of Inducible cAMP Early Repressor (ICER) in Methamphetamine-Induced Locomotor Sensitization

BACKGROUND: The inducible cyclic adenosine monophosphate (cAMP) early repressor (ICER) is highly expressed in the central nervous system and functions as a repressor of cAMP response element-binding protein (CREB) transcription. The present study sought to clarify the role of ICER in the effects of methamphetamine (METH). METHODS AND FINDINGS: We tested METH-induced locomotor sensitization in wildtype mice, ICER knockout mice, and ICER I-overexpressing mice. Both ICER wildtype mice and knockout mice displayed increased locomotor activity after continuous injections of METH. However, ICER knockout mice displayed a tendency toward higher locomotor activity compared with wildtype mice, although no significant difference was observed between the two genotypes. Moreover, compared with wildtype mice, ICER I-overexpressing mice displayed a significant decrease in METH-induced locomotor sensitization. Furthermore, Western blot analysis and quantitative real-time reverse transcription polymerase chain reaction demonstrated that ICER overexpression abolished the METH-induced increase in CREB expression and repressed cocaine- and amphetamine-regulated transcript (CART) and prodynorphin (Pdyn) expression in mice. The decreased CART and Pdyn mRNA expression levels in vivo may underlie the inhibitory role of ICER in METH-induced locomotor sensitization. CONCLUSIONS: Our data suggest that ICER plays an inhibitory role in METH-induced locomotor sensitization

Molecular evolution of vertebrate sex-determining genes

Y-linked Dmy (also called dmrt1bY) in the teleost fish medaka, W-linked Dm-W in the African clawed frog (Xenopus laevis), and Z-linked Dmrt1 in the chicken are all sex chromosome-linked Dmrt1 homologues required for sex determination. Dmy and Dm-W both are Dmrt1 palalogues evolved through Dmrt1 duplication, while chicken Dmrt1 is a Z-linked orthologue. The eutherian sex-determining gene, Sry, evolved from an allelic gene, Sox3. Here we analyzed the exon–intron structures of the Dmrt1 homologues of several vertebrate species through information from databases and by determining the transcription initiation sites in medaka, chicken, Xenopus, and mouse. Interestingly, medaka Dmrt1 and Dmy and Xenopus Dm-W and Dmrt1 have a noncoding-type first exon, while mouse and chicken Dmrt1 do not. We next compared the 5′-flanking sequences of the Dmrt1 noncoding and coding exons 1 of several vertebrate species and found conservation of the presumptive binding sites for some transcription factors. Importantly, based on the phylogenetic trees for Dmrt1 and Sox3 homologues, it was implied that the sex-determining gene Dmy, Dm-W, and Sry have a higher substitution rate than thier prototype genes. Finally, we discuss the evolutionary relationships between vertebrate sex chromosomes and the sex-determining genes Dmy/Dm-W and Sry, which evolved by neofunctionalization of Dmrt1 and Sox3, respectively, for sex determining function. We propose a coevolution model of sex determining gene and sex chromosome, in which undifferentiated sex chromosomes easily allow replacement of a sex-determining gene with another new one, while specialized sex chromosomes are restricted a particular sex-determining gene