To examine the effects of decreased food consumption on toxicological parameters in juvenile rats, rats on postnatal day 21 were fed 40%, 50% (only four weeks), and 60% less food, compared to that of controls for four or eight weeks, and clinical observations, measurement of body and organ weights, morphological differentiation analysis, clinical pathology, and macroscopic and microscopic examinations were conducted. The body weight decreased depending on the degree of food restriction (FR). Cleavage of the balano-preputial skinfold was delayed, and cell debris in the epididymal lumen was noted as a related finding after four-week FR.
View Article and Find Full Text PDFBiochem Biophys Res Commun
October 2023
The Matsumoto Eosinophilia Shinshu (MES) is a rat model for hereditary blood eosinophilia. The incidence of eosinophilia is 100% in both female and male MES. The primary cause of the eosinophilia in MES is a loss-of-function mutation in the gene encoding the cytochrome b-245, alpha polypeptide (Cyba mutant allele).
View Article and Find Full Text PDFRecently we provided a new interpretation that increased serum ALP in dogs is not adverse if no hepatotoxic finding coexists in the analysis of toxicity studies of over 200 pesticides evaluated in Japan (Yokoyama et al., 2019). We also proposed a decision tree to evaluate the adversity of the increased ALP.
View Article and Find Full Text PDFEhlers-Danlos syndromes (EDSs) are heterogeneous group of heritable connective tissue disorders characterized by joint and skin hyperextensibility as well as fragility of various organs. Recently, we described a new type of EDS, musculocontractual EDS (mcEDS-CHST14), caused by pathogenic variants of the carbohydrate sulfotransferase 14 (CHST14) gene mutation. B6;129S5-Chst14/Mmucd (B6;129-Chst14 KO) mice are expected to be an animal model of mcEDS-CHST14.
View Article and Find Full Text PDFThe black carbon or elemental carbon (EC) content in ice and snow has been a concern in climate change studies, but time-series records have mostly been obtained from glacier ice-core samples in limited geographical locations, such as the Arctic or high mountains. This is the first study to present decade-long records of EC deposition measured at urban (Sapporo) and background (Rishiri Island) sites in Japan, in the mid-latitude zone of the eastern edge of the Asian continent. By using archived membrane filters from an acid rain study, we retrieved monthly EC deposition records of 1993-2012 in Sapporo and intermittent deposition data in Rishiri.
View Article and Find Full Text PDFIncreased serum alkaline phosphatase (ALP) activity is an indicator of hepatobiliary damage in humans and experimental animals. Practically, increased ALP accompanied by no other hepatotoxic changes is often encountered in toxicity studies of pesticides in dogs. Here, we analyzed the toxicological significance of increased ALP in response to 206 pesticides evaluated by the Food Safety Commission of Japan as toxicological evaluation reports in their risk assessment process.
View Article and Find Full Text PDFLocomotor activity is affected by a range of factors in addition to experimental treatment, including the breeding environment. Appropriate convalescence and acclimation are important for animal experiments, because environmental changes and physical burden can result from surgery, transportation, and cage exchange. However, the duration that locomotor activity is affected by these factors is currently unclear, because it has traditionally been difficult to measure locomotor activity in multiple group-housed animals in any location other than the analysis room.
View Article and Find Full Text PDFAtrazine, a commonly used herbicide, suppresses the luteinizing hormone (LH) surge in female rats, although the underlying mechanism remains unclear. Kisspeptin, encoded by the Kiss1 gene, is a hypothalamic peptide that controls gonadotropin-releasing hormone (GnRH) release from the GnRH neurons. Kisspeptin neurons in the anteroventral periventricular nucleus (AVPV) are involved in regulating pre-ovulatory GnRH and LH surge.
View Article and Find Full Text PDFMethods Mol Biol
February 2019
Recently, a long-term (1-year) dog toxicity study has not been a mandatory toxicity study for application of agricultural chemical in the United States (US) and the European Union (EU). This study was conducted to propose a guide for making science-based judgement on the necessity of long-term dog toxicity study, which is one of required toxicity studies at toxicological evaluation in Japanese pesticide regulation system. In order to carry out the proposal we analyzed the results of toxicity studies including subacute (3-month) toxicity study in dogs or toxicity studies in other species in the pesticide evaluation reports published by the Food Safety Commission of Japan (FSCJ), the responsible regulatory body for toxicological evaluation of pesticides in food.
View Article and Find Full Text PDFCollagen is one of the most important components of the extracellular matrix that is involved in the strength of tissues, cell adhesion and cell proliferation. Mutations in several collagen and post-translational modification enzyme genes cause Ehlers-Danlos syndrome (EDS) characterized by joint and skin hyperextensibility as well as fragility of various organs. Carbohydrate sulfotransferase 14/dermatan 4-O-sulfotransferase-1 (CHST14/D4ST1) is a critical enzyme for biosynthesis of dermatan sulfate, a side chain of various proteoglycans including biglycan that regulates collagen fibrils through their interaction.
View Article and Find Full Text PDFMouse senile amyloidosis is a disorder in which apolipoprotein A-II (APOA2) deposits as amyloid fibrils (AApoAII) in many organs. We previously reported that AApoAII amyloidosis can be transmitted by feces, milk, saliva and muscle originating from mice with amyloid deposition. In this study, the ability of blood components to transmit amyloidosis was evaluated in our model system.
View Article and Find Full Text PDFWe present a near-infrared (NIR) spectrum measurement method using a Schottky photodetector enhanced by surface plasmon resonance (SPR). An Au grating was fabricated on an n-type silicon wafer to form a Schottky barrier and act as an SPR coupler. The resulting photodetector provides wavelength-selective photodetection depending on the SPR coupling angle.
View Article and Find Full Text PDFThis paper describes a theoretical estimation of the geometry of negative epoxy-resist microneedles prepared via inclined/rotated ultraviolet (UV) lithography based on spatially controlled UV exposure doses. In comparison with other methods based on UV lithography, the present method can create microneedle structures with high scalability. When negative photoresist is exposed to inclined/rotated UV through circular mask patterns, a three-dimensional, needle-shaped distribution of the exposure dose forms in the irradiated region.
View Article and Find Full Text PDFSurfaces covered with hydrophobic micro-/nanoscale textures can allow water droplets to slide easily because of low contact angle hysteresis. In contrast to the case of a droplet sliding on a smooth surface, when a droplet slides on a textured surface, it must recede from the textures at its rear edge and the resultant depinning events induce a capillary wave on the surface of the droplet. Although this depinning-induced capillary wave can be observed to some extent through high-speed imaging, important parameters of the wave, such as the wavelength and frequency, and the factors that determine these parameters are not fully understood.
View Article and Find Full Text PDFThis paper reports on a tactile sensor using piezoresistive beams for detection of the coefficient of static friction merely by pressing the sensor against an object. The sensor chip is composed of three pairs of piezoresistive beams arranged in parallel and embedded in an elastomer; this sensor is able to measure the vertical and lateral strains of the elastomer. The coefficient of static friction is estimated from the ratio of the fractional resistance changes corresponding to the sensing elements of vertical and lateral strains when the sensor is in contact with an object surface.
View Article and Find Full Text PDFDoxorubicin (DOX) is one of the best known anticancer drugs, and is used in the treatment of lymphoma, lung cancer, stomach cancer, and a number of other cancers. However, DOX has some serious side effects, the worst being lethal heart failure. Occasionally, its side effects result in the cessation of the anticancer treatment, thus having a serious adverse influence on prognosis.
View Article and Find Full Text PDFWe propose a reconfigurable terahertz (THz) metamaterial that can control the transmittance by out-of-plane actuation with changing the sub-micron gap distance between electrically coupled metamaterial elements. By using the out-of-plane actuation, it was possible to avoid contact between the coupled metamaterial elements across the small initial gap during the adjustment of the gap size. THz spectroscopy was performed during actuation, and the transmission dip frequency was confirmed to be tunable from 0.
View Article and Find Full Text PDFActive modulation of the polarization states of terahertz light is indispensable for polarization-sensitive spectroscopy, having important applications such as non-contact Hall measurements, vibrational circular dichroism measurements and anisotropy imaging. In the terahertz region, the lack of a polarization modulator similar to a photoelastic modulator in the visible range hampers expansion of such spectroscopy. A terahertz chiral metamaterial has a huge optical activity unavailable in nature; nevertheless, its modulation is still challenging.
View Article and Find Full Text PDFWe report a simple technique to measure the free vibration of microlitre-sized droplets using an array of thirteen MEMS-based piezoresistive cantilevers and demonstrate its application for the measurement of viscosity. Because the damping of the free vibration of a liquid droplet is known to be affected by the viscosity of the liquid, measuring the vibration of a droplet allows the viscosity to be estimated from a dilute sample volume. However, conventional methods to measure the droplet vibration require sophisticated apparatuses, which hinder the development of a portable viscometer.
View Article and Find Full Text PDFCongenit Anom (Kyoto)
August 2014
Historical control data on rodent developmental toxicity studies, performed between 1994 and 2010, were obtained from 19 laboratories in Japan, including 10 pharmaceutical and chemical companies and nine contract research organizations. Rats, mice, and hamsters were used for developmental toxicity studies. Data included maternal reproductive findings at terminal cesarean sections and fetal findings including the spontaneous incidences of external, visceral, and skeletal anomalies.
View Article and Find Full Text PDFThalidomide (TM) induces limb defects in humans and some animal species including rabbits. Although the mechanism of TM-induced limb defects has been investigated for a long period, the limb development-related genes expressions have not been vigorously characterized in rabbits. In this study, we investigated the Fgf8, Bmp4 and Hoxa11 expressions in TM-treated JW rabbit embryos on gestation days (GDs) 10, 11 and 12 by whole mount in situ hybridization.
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