No-observed-adverse-effect-level (NOAEL) clothianidin, a neonicotinoid pesticide, impairs hippocampal memory and motor learning associated with alteration of gene expression in cerebellum.

Neonicotinoid pesticides (NNs) have been associated with numerous neurobehavioral effects in rodents, raising concerns about their impact on cognitive function. Clothianidin (CLO), a type of NN, was orally administered to male mice (10 weeks old, C57BL/6N) at the no-observed-adverse-effect level (NOAEL) of 50 mg/kg/day as indicated in the pesticide risk assessment report. Behavioral tests (novel location recognition and rotarod tests) evaluated hippocampal memory and cerebellar motor learning. After each test, plasma monoamines (3-methoxytyramine, histamine, serotonin, tryptamine) were measured by LC-ESI/MS/MS (Liquid chromatography-electrospray ionization/tandem mass spectrometry), and cerebellar mRNA expression was quantified by microarray and qRT-PCR analyses. The NOAEL of CLO was found to impair hippocampal memory, leading to decreased spontaneous locomotor activity and motor function. We reported, for the first time, multiple alterations of gene expression in the cerebellum associated with motor dysfunction.

Effect of clothianidin exposure at the no-observed-adverse-effect level (NOAEL) in a mouse model of atopic dermatitis.

The effects of exposure to clothianidin (CLO), a neonicotinoid pesticide (NN), on the thymus and intestinal microbiota were recently revealed. Immune cells express nicotinic acetylcholine receptors (nAChRs), an NN target, suggesting CLO may disrupt the immune system. However, the relationship between CLO and atopic dermatitis (AD) is unknown. We administered a no-adverse-effect-level (NOAEL) dose of CLO to male NC/Nga mice with induced AD and measured, at three time points, key AD symptom indicators: epidermal thickening, mast cell number, total plasma IgE, and histamine levels. CLO increased total plasma IgE levels but reduced epidermal thickening, mast cell number, and plasma histamine levels in the early stages of AD. This demonstrates for the first time that CLO exposure inhibits AD's early symptoms.

Simultaneous Visualization of Microscopic Conductivity and Deformation in Conductive Elastomers.

Conductive elastomers are promising for a wide range of applications in many fields due to their unique mechanical and electrical properties, and an understanding of the conductive mechanisms of such materials under deformation is crucial. However, revealing the microscopic conduction mechanism of conductive elastomers is a challenge. In this study, we developed a method that combines in situ deformation nanomechanical atomic force microscopy (AFM) and conductive AFM to successfully and simultaneously characterize the microscopic deformation and microscopic electrical conductivity of nanofiller composite conductive elastomers. With this approach, we visualized the conductive network structure of carbon black and carbon nanotube composite conductive elastomers at the nanoscale, tracked their microscopic response under different compressive strains, and revealed the correlation between microscopic and macroscopic electrical properties. This technique is important for understanding the conductive mechanism of conductive elastomers and improving the design of conductive elastomers.

Effects of exposure to the neonicotinoid pesticide clothianidin on α-defensin secretion and gut microbiota in mice.

The mechanism by which the neonicotinoid pesticide clothianidin (CLO) disrupts the intestinal microbiota of experimental animals is unknown. We focused on α-defensins, which are regulators of the intestinal microbiota. Subchronic exposure to CLO induced dysbiosis and reduced short-chain fatty acid-producing bacteria in the intestinal microbiota of mice. Levels of cryptdin-1 (Crp1, a major α-defensin in mice) in feces and cecal contents were lower in the CLO-exposed groups than in control. In Crp1 immunostaining, Paneth cells in the jejunum and ileum of the no-observed-adverse-effect-level CLO-exposed group showed a stronger positive signal than control, likely due to the suppression of Crp1 release. Our results showed that CLO exposure suppresses α-defensin secretion from Paneth cells as part of the mechanism underlying CLO-induced dysbiosis.

Insights into Mechanical Dynamics of Nanoscale Interfaces in Epoxy Composites Using Nanorheology Atomic Force Microscopy.

Interfacial polymer layers with nanoscale size play critical roles in dissipating the strain energy around cracks and defects in structural nanocomposites, thereby enhancing the material's fracture toughness. However, understanding how the intrinsic mechanical dynamics of the interfacial layer determine the toughening and reinforcement mechanisms in various polymer nanocomposites remains a major challenge. Here, by means of a recently developed nanorheology atomic force microscopy method, also known as nanoscale dynamic mechanical analysis (nDMA), we report direct mapping of dynamic mechanical responses at the interface of a model epoxy nanocomposite under the transition from a glassy to a rubbery state. We demonstrate a significant deviation in the dynamic moduli of the interface from matrix behavior. Interestingly, the sign of the deviation is observed to be reversed when the polymer changes from a glassy to a rubbery state, which provides an excellent explanation for the difference in the modulus reinforcement between glassy and rubbery epoxy nanocomposites. More importantly, nDMA loss tangent images unambiguously show an enhanced viscoelastic response at the interface compared to the bulk matrix in the glassy state. This observation can therefore provide important insights into the nanoscale toughening mechanism that occurs in epoxy nanocomposites due to viscoelastic energy dissipation at the interface.

In Situ Nanostress Visualization Method to Reveal the Micromechanical Mechanism of Nanocomposites by Atomic Force Microscopy.

An in situ atomic force microscopy (AFM) nanomechanical technique was used to directly visualize the micromechanical behaviors of polymer nanocomposites during compressive strain. We obtained a stress distribution image of carbon black (CB)-filled rubber at the nanoscale for the first time, and we traced the microscopic deformation behaviors of CB particles. Through this experiment, we directly revealed the microscopic reinforcement mechanisms of rubber composites. We found that CB-filled rubbers exhibited heterogeneous local microscopic deformations, which were related to the dispersion of CB particles in rubber matrices. The local stress distributions of the rubber composites showed heterogeneity, and the stresses were concentrated in the regions near the CB particles during compression. The area of stress concentration gradually expanded with increasing strain and eventually formed a stress network structure. This stress network bore most of the macroscopic stress and was considered the key reinforcement mechanism of CB-filled rubber. The stress transfer process in the rubber matrix was visualized in real space for the first time. Based on the image data from the AFM experiments, we used finite-element method (FEM) simulations to reproduce the microscopic deformation process of CB-filled rubber. The stress distribution images simulated by FEM showed heterogeneity consistent with AFM. In this study, an in situ visualization of material deformation confirmed the predictions of microscopic deformation behavior from previous theories and models; it also provided new insights into the microscopic reinforcement mechanisms of CB-filled rubber composites based on microscopic stress distribution images.

Direct Visualization of Interfacial Regions between Fillers and Matrix in Rubber Composites Observed by Atomic Force Microscopy-Based Nanomechanics Assisted by Electron Tomography.

In order to explain or predict the macroscopic mechanical properties of polymer composites with complex nanostructures, atomic force microscopy (AFM)-based nanomechanics is one of the most appropriate tools because the local mechanical properties can be obtained by it. However, automatic force curve analysis based on contact mechanics would mislead us to the wrong conclusion. The purpose of this study is to elucidate this point by applying AFM nanomechanics on a carbon black (CB)-reinforced isoprene rubber (IR). The CB aggregates underneath the rubber surface prevent us from quantitatively evaluating the ratio of CB and interfacial polymer region (IPR), which is an important parameter to determine the macroscopic mechanical properties. In order to overcome this problem, transmission electron microtomography was incorporated to investigate the 3D structure in the same field of view as AFM nanomechanics. As a result, it was found that there are buried structures that do not appear in the AFM topographic image. In addition, we were able to reveal the existence of a force curve with an inflection point, which is characteristic of such "false" IPRs. To put it another way, we evidenced the existence of true IPRs for the first time by combining these state-of-the-art techniques.

Reinforcement Mechanism of Carbon Black-Filled Rubber Nanocomposite as Revealed by Atomic Force Microscopy Nanomechanics.

In this study, atomic force microscopy (AFM) nanomechanics were used to visualize the nanoscale stress distribution in carbon black (CB)-reinforced isoprene rubber (IR) vulcanizates at different elongations and quantitatively evaluate their volume fractions for the first time. The stress concentrations in the protofibrous structure (stress chains) that formed around the CB filler in CB-reinforced IR vulcanizates were directly observed at the nanoscale. The relationship between the local nanoscale stress distribution and macroscopic tensile properties was revealed based on the microscopic stress distribution and microscopic spatial structure. This study can help us gain insight into the microscopic reinforcement mechanism of carbon black-containing rubber composites.

Genetic diversity of two populations of the tufted puffin Fratercula cirrhata (Pallas, 1769).

The tufted puffin Fratercula cirrhata (Charadriiformes: Alcidae) is distributed throughout the boreal and low Arctic areas of the North Pacific, from California, USA to Hokkaido, Japan. Few studies have investigated the genetic diversity of this species. Therefore, we analyzed the genetic diversity of two captive populations using nucleotide sequences of two mitochondrial loci (COX1 and D-loop) and one nuclear locus (RHBG). We sequenced these loci for birds from Tokyo Sea Life Park (Kasai Rinkai Suizokuen), originally from Alaska, and birds from Aqua World Oarai, originally from far eastern Russia. We found five COX1 haplotypes and 17 D-loop haplotypes for the mitochondrial loci, and obtained 14 predicted haplotypes for the nuclear RHBG locus. The major haplotypes of all three loci occurred in individuals from both populations. Thus, there were no clear genetic differences between the populations with respect to these three loci. Although the breeding range of the tufted puffin covers the boreal and low Arctic from California to Hokkaido, our results suggest that the species has not genetically diverged within its breeding range.

Identification and Characterization of 3-epi-Rotundone, a Novel Stereoisomer of Rotundone, in Several Kinds of Fruits.

A novel stereoisomer of rotundone, 3-epi-rotundone, was identified in the aroma of grapefruit, orange, apple, and mango. 3-epi-Rotundone was prepared by the isomerization of rotundone, and its structural elucidation was confirmed by comparing the 1D and 2D nuclear magnetic resonance and nuclear Overhauser effect spectroscopy spectra with those of rotundone. The odor thresholds of rotundone and 3-epi-rotundone in water were determined by a triangle test as 5 and 19100 ng/kg, respectively. The odor of 3-epi-rotundone was evaluated as woody, spicy, peppery, citrus, grapefruit-like, powdery, and celery-like, which was a greater range of odor characteristics than that for rotundone. Results of odor evaluation of 3-epi-rotundone revealed that its unique organoleptic properties, which were odor description (woody, spicy, and peppery), anosmic properties in neat form, and strong adaptation, were similar to those of rotundone. 3-epi-Rotundone might be a valuable substance to apply new types of woody, peppery, and spicy notes.

Three cases of rhegmatogenous retinal detachment associated with regressed retinoblastoma after conservative tumor therapy.

PURPOSE: To report three cases of rhegmatogenous retinal detachment associated with regressed retinoblastoma after conservative therapy. METHODS: Three eyes of three patients with rhegmatogenous retinal detachment, in which retinal breaks were present at the edge of the tumor scar, were treated with vitrectomy and scleral buckling. RESULTS: In two eyes, in which cryopexy and silicone oil injection were performed, a preretinal membrane was formed that was comprised primarily of glial cells. Additional vitrectomy and membrane peeling reattached the retina. In one eye, in which photocoagulation and gas injection were performed, an initial vitrectomy and scleral buckling reattached the retina without postoperative membrane formation. CONCLUSION: Vitrectomy and scleral buckling contributed to closure of the irregularly shaped retinal tear at the edge of the tumor scar. Photocoagulation and gas injection instead of cryopexy and silicone oil injection may avoid postoperative glial proliferation from the tumor scar.

Nano-palpation AFM and its quantitative mechanical property mapping.

We review nano-palpation atomic force microscopy, which offers quantitative mechanical property mapping especially for soft materials. The method measures force-deformation curves on the surfaces of soft materials. The emphasis is placed on how both Hertzian and Derjaguin-Muller-Toporov contact mechanics fail to reproduce the experimental curves and, alternatively, how the Johnson-Kendall-Roberts model does. We also describe the force-volume technique for obtaining a two-dimensional map of mechanical properties, such as the elastic modulus and adhesive energy, based on the above-mentioned analysis. Finally, we conclude with several counterpart measurements, which describe the viscoelastic nature of soft materials, and give examples, including vulcanized isoprene rubber and the current status of ISO standardization.

Visual outcomes after early vitreous surgery for aggressive posterior retinopathy of prematurity.

IMPORTANCE: Aggressive posterior retinopathy of prematurity (AP-ROP) rapidly progresses to retinal detachment despite application of photocoagulation. Early vitreous surgery might achieve prompt regression of neovascular activity and a high incidence of retinal reattachment. OBJECTIVE: To evaluate visual outcomes in eyes with AP-ROP after early vitreous surgery. DESIGN: Retrospective nonrandomized study of patients who underwent early vitreous surgery with lensectomy when retinal detachment developed despite photocoagulation. Aphakic correction with spectacles or contact lenses and the use of orthoptics were continued postoperatively. The best-corrected visual acuity (VA) was measured in eyes with a total retinal reattachment using the preferential looking technique in patients ranging in age from 8 months to no more than 3 years and a VA chart with Landolt rings or pictures for older children. The VA findings were converted to Snellen lines. SETTING: Institutional ophthalmology practice. PARTICIPANTS: Of the 103 eyes (57 patients) that underwent early vitreous surgery for AP-ROP, the VA was measured in 58 (32 patients) at a corrected age ranging from 8 months to 4 years. INTERVENTIONS: Early vitreous surgery and VA measurement using the preferential looking technique and a VA chart. MAIN OUTCOMES AND MEASURES: Postoperative VA, ROP stage, extent of fibrovascular tissue (FT) growth, and laterality of the eyes that underwent surgery. RESULTS: The VAs ranged from 20/2000 to 20/40. The VA may not be related to the preoperative ROP stage 4A or 4B but may depend on the preoperative extent of FT growth. In 39 of 58 eyes (67.2%), the FT had not reached the vitreous base preoperatively, and foveal formation occurred postoperatively with nearly age-appropriate VA (range, 20/250 to 20/40). In 17 of 58 eyes (29.3%), the FT had reached the vitreous base, and no fovea formed (VA range, 20/2000 to 20/250). Two of 58 eyes (3.4%) had deprivation amblyopia with a VA worse than 20/1600. The difference in VA between both eyes of patients who underwent bilateral vitreous surgery depended on ROP progression; patients who underwent a unilateral procedure in which the fellow eyes with ROP stabilized after photocoagulation tended to have poor vision because of deprivation amblyopia. CONCLUSIONS AND RELEVANCE: Early vitreous surgery may be beneficial for AP-ROP and should be performed before the FT reaches the vitreous base to facilitate foveal formation and good VA outcomes. The roles of photocoagulation, vitreous surgery, and anti-vascular endothelial growth factor therapy in the treatment of AP-ROP should be investigated in randomized trials regarding efficacy, safety, convenience, and cost.

O-linked-N-acetylglucosamine modification of mammalian Notch receptors by an atypical O-GlcNAc transferase Eogt1.

O-linked-ß-N-acetylglucosamine (O-GlcNAc) modification is a unique cytoplasmic and nuclear protein modification that is common in nearly all eukaryotes, including filamentous fungi, plants, and animals. We had recently reported that epidermal growth factor (EGF) repeats of Notch and Dumpy are O-GlcNAcylated by an atypical O-GlcNAc transferase, EOGT, in Drosophila. However, no study has yet shown whether O-GlcNAcylation of extracellular proteins is limited to insects such as Drosophila or whether it occurs in other organisms, including mammals. Here, we report the characterization of A130022J15Rik, a mouse gene homolog of Drosophila Eogt (Eogt 1). Enzymatic analysis revealed that Eogt1 has a substrate specificity similar to that of Drosophila EOGT, wherein the Thr residue located between the fifth and sixth conserved cysteines of the folded EGF-like domains is modified. This observation is supported by the fact that the expression of Eogt1 in Drosophila rescued the cell-adhesion defect caused by Eogt downregulation. In HEK293T cells, Eogt1 expression promoted modification of Notch1 EGF repeats by O-GlcNAc, which was further modified, at least in part, by galactose to generate a novel O-linked-N-acetyllactosamine structure. These results suggest that Eogt1 encodes EGF domain O-GlcNAc transferase and that O-GlcNAcylation reaction in the secretory pathway is a fundamental biochemical process conserved through evolution.

Investigation of the feasibility of a simple method for verifying the motion of a binary multileaf collimator synchronized with the rotation of the gantry for helical tomotherapy.

In this paper, we suggest a new method for verifying the motion of a binary multileaf collimator (MLC) in helical tomotherapy. For this we used a combination of a cylindrical scintillator and a general-purpose camcorder. The camcorder records the light from the scintillator following photon irradiation, which we use to track the motion of the binary MLC. The purpose of this study is to demonstrate the feasibility of this method as a binary MLC quality assurance (QA) tool. First, the verification was performed using a simple binary MLC pattern with a constant leaf open time; secondly, verification using the binary MLC pattern used in a clinical setting was also performed. Sinograms of simple binary MLC patterns, in which leaves that were open were detected as "open" from the measured light, define the sensitivity which, in this case, was 1.000. On the other hand, the specificity, which gives the fraction of closed leaves detected as "closed", was 0.919. The leaf open error identified by our method was -1.3 ± 7.5%. The 68.6% of observed leaves were performed within ± 3% relative error. The leaf open error was expressed by the relative errors calculated on the sinogram. In the clinical binary MLC pattern, the sensitivity and specificity were 0.994 and 0.997, respectively. The measurement could be performed with -3.4 ± 8.0% leaf open error. The 77.5% of observed leaves were performed within ± 3% relative error. With this method, we can easily verify the motion of the binary MLC, and the measurement unit developed was found to be an effective QA tool.

O-linked-N-acetylglucosamine on extracellular protein domains mediates epithelial cell-matrix interactions.

The O-linked-N-acetylglucosamine (O-GlcNAc) modification of cytoplasmic and nuclear proteins regulates basic cellular functions and is involved in the aetiology of diabetes and neurodegeneration. This intracellular O-GlcNAcylation is catalyzed by a single O-GlcNAc transferase, OGT. Here we report a novel OGT, EOGT, responsible for extracellular O-GlcNAcylation. Although both OGT and EOGT are regulated by hexosamine flux, EOGT localizes to the lumen of the endoplasmic reticulum and transfers GlcNAc to epidermal growth factor-like domains in an OGT-independent manner. Loss of Eogt gives phenotypes similar to those caused by defects in the apical extracellular matrix. Dumpy (Dp), a membrane-anchored extracellular protein, is O-GlcNAcylated, and EOGT is required for Dp-dependent epithelial cell-matrix interactions. Thus, O-GlcNAcylation of secreted and membrane glycoproteins is a novel mediator of cell-cell or cell-matrix interactions at the cell surface.

Transition processes from the lamellar to the onion state with increasing temperature under shear flow in a nonionic surfactant/water system studied by Rheo-SAXS.

In a previous paper, we reported for the first time the lamellar-to-onion transition with increasing temperature at around 67 °C under a constant shear rate (0.3-10 s(-1)) in a nonionic surfactant C(16)E(7)/water system. In this study, the first temperature-shear rate diagram has been constructed in a wider range of shear rate (0.05-30 s(-1)) than in our previous study based on the temperature dependence of the shear stress at constant shear rate. The results suggest that the critical temperature above which the transition begins does not depend on the shear rate very much, although it takes a very shallow minimum. Then we have performed simultaneous measurements of small-angle X-ray scattering/shear stress (rheo-SAXS) with a stepwise increase in temperature of 0.1 K per 15 min at a constant shear rate of 3 s(-1) near the transition temperature. When the temperature exceeds 67 °C, just before the increase in the shear stress, the intensity of the Bragg peak for the velocity gradient direction (approximately proportional to the number of lamellae with their normal along this direction) is suddenly increased. As the temperature increases by 0.2 K, the shear stress begins to increase. At the same time, the peak intensity in the velocity gradient direction rapidly decreases and instead the intensity in the neutral direction increases. As the temperature increases further, the intensities in both the neutral and gradient directions decrease whereas the intensity in the flow direction increases, corresponding to the formation of onions. We have also performed rheo-SAXS experiments with a stepwise increase in shear rate at 72 °C. The sequence of the change in the intensity in each direction is almost the same in the temperature scan experiments at constant shear rate, suggesting that the transition mechanisms along these two paths are similar. The abrupt enhancement of the lamellar orientation with the layer normal along the velocity gradient direction just before the transition is the first finding and strongly supports the coherent buckling mechanism in the lamellar-to-onion transition proposed by Zilman and Granek (Zilman, A. G.; Granek, R. Eur. Phys. J. B 1999, 11, 593).

Variability in bladder volumes of full bladders in definitive radiotherapy for cases of localized prostate cancer.

BACKGROUND AND PURPOSE: To evaluate variation in bladder volume of full bladders in definitive radiotherapy for localized prostate cancer and to investigate potential predictors of increased bladder volume variations. PATIENTS AND METHODS: In 40 patients, the bladder volume was measured with megavoltage computed tomography (MVCT) imaging performed just before irradiation during the administration of the 1st fraction (#1), the 10th fraction (#10), the 20th fraction (#20), and the 30th fraction (#30). Patients were instructed to avoid urinating for 60-90 minutes before the planning CT (pln-CT) scan and before daily irradiation. Patients were also encouraged to drink an unspecified volume of liquid that would result in a clear but tolerable urge to urinate. RESULTS: The population-mean bladder volume (±1SD) was 219 ml (±83 ml) at the planning CT scan (pln-CT), 186 ml (±96 ml) at #1, 149 ml (±73 ml) at #10, 137 ml (±59 ml) at #20, and 136 ml (±60 ml) at #30. The mean intrapatient variation in bladder volume (1 SD relative to the mean bladder volume of each patient) was 38% (range: 10-84%). The bladder volume at the pln-CT was correlated with the intrapatient variance in bladder volume with a correlation coefficient of 0.54 and p <0.001. CONCLUSION: We observed a significant decline in bladder volumes during the course of radiotherapy. The bladder volume at the pln-CT was a significant predictor of increased bladder volume variations.

Lamellar-to-onion transition with increasing temperature under shear flow in a nonionic surfactant/water system.

Simultaneous measurements of small-angle light scattering/shear stress (Rheo-SALS) and small-angle X-ray scattering/shear stress (Rheo-SAXS) have been performed in the lamellar phase of the C(16)E(7)/D(2)O system. As the temperature is increased and exceeds 67 degrees C at constant shear rates (at 1 and 3 s(-1)), the shear stress increases abruptly and a four-lobe pattern is observed in the depolarized SALS. These results suggest that the lamellar-to-onion transition occurs with increasing temperature, which has not yet been reported. The diameter of onions obtained from the depolarized SALS pattern at 3 s(-1) increases with increasing temperature. The transition is reversible against the change in temperature. The Rheo-SALS measurements have also been made with a stepwise increase in shear rate at constant temperature. The results are consistent with the above temperature-scan experiments at constant shear rate, suggesting that the transition does not depend on the path. The variation of the SAXS pattern at 3 s(-1) indicates that the orientation of lamellae becomes isotropic as the temperature is increased from 67 to 69 degrees C, which also supports the lamellar-to-onion transition. The transition temperature at constant shear rate (at 3 s(-1)) increases rapidly with a slight increase in surfactant concentration. From this, together with the SAXS results at rest in our previous study, we deduce that an increase in the water-layer thickness is necessary for the lamellar-to-onion transition with increasing temperature.