884 research outputs found

    Buckling Cascade of Thin Plates: Forms, Constraints and Similarity

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    We experimentally study compression of thin plates in rectangular boxes with variable height. A cascade of buckling is generated. It gives rise to a self-similar evolution of elastic reaction of plates with box height which surprisingly exhibits repetitive vanishing and negative stiffness. These features are understood from properties of Euler's equation for elastica

    Duodenum-Preserving Resection of the Head of the Pancreas: The Significance as a Diagnostic Therapy for the Lesion in the Pancreatic Head

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    A 75-year-old man who was diagnosed as having mucin-producing pancreatic cystic lesion ofthe main pancreatic duct by duodenoscopic examination was reported. Because of the low malignant potential of such lesions, duodenum-preserving resection of the head of the pancreas was performed, and the intra-operative histological examination showed no malig-nancy of the resected pancreatic head and no other surgical procedures, such as lymph-adenectomy nor pancreato-duodenectomy were necessary. The significance of this case report lies in that a less invasive operation should be selected at first to diagnose whether the lesion is malignant or not, and als0 that the selected operation itself must be sufficient to resect an adequate part of the pancreatic tissue involving the cystic lesion, ifnot malignant. Here, we report the process to select the procedure and the surgical technique

    Expression and Localization of the Cell Adhesion Molecule SgIGSF during Regeneration of the Olfactory Epithelium in Mice

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    Spermatogenic immunoglobulin superfamily (SgIGSF) is a cell adhesion molecule originally discovered in mouse testis. SgIGSF is expressed not only in spermatogenic cells but also in lung and liver epithelial cells and in neurons and glia of the central and peripheral nervous systems. In the present study, we examined the expression and localization of SgIGSF in mouse olfactory epithelium before and after transection of the olfactory nerves, by RT-PCR, Western blotting and immunohistochemistry. In normal olfactory mucosa, SgIGSF showed 100 kDa in molecular weight, which was identical with that in the lung but different from that in the brain. SgIGSF was expressed on the membrane of all olfactory, sustentacular and basal cells, but more abundantly in the apical portions of the olfactory epithelium where the dendrites of olfactory cells are in contact with sustentacular cells. After olfactory nerve transection, mature olfactory cells disappeared in 4 days but were regenerated around 7–15 days by proliferation and differentiation of basal cells into mature olfactory cells through the step of immature olfactory cells. During this period, both the mRNA and protein for SgIGSF showed a transient increase, with peak levels at 7 days and 11 days, respectively, after the transection. Immunohistochemistry showed that the enriched immunoreactivity for SgIGSF at 7–11 days was localized primarily to the membrane of immature olfactory cells. These results suggested that, during regeneration of the olfactory epithelium, the adhesion molecule SgIGSF plays physiological roles in differentiation, migration, and maturation of immature olfactory cells

    Freezing of gait and white matter changes: a tract-based spatial statistics study.

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    BACKGROUND: We hypothesized that the integrity of white matter might be related to the severity of freezing of gait in age-related white matter changes. METHODS: Twenty subjects exhibiting excessive hyperintensities in the periventricular and deep white matter were recruited. The subjects underwent the Freezing of Gait Questionnaire, computerized gait analyses, and diffusion tensor magnetic resonance imaging. Images of axial, radial and mean diffusivity, and fractional anisotropy were calculated as indices of white matter integrity and analyzed with tract-based spatial statistics. RESULTS: The fractional anisotropy, mean, axial and radial diffusivity averaged across the whole white matter structure were all significantly correlated with Freezing of Gait Questionnaire scores. Regionally, a negative correlation between Freezing of Gait Questionnaire scores and fractional anisotropy was found in the left superior longitudinal fasciculus beneath the left premotor cortex, right corpus callosum, and left cerebral peduncle. The scores of the Freezing of Gait Questionnaire were positively correlated with mean diffusivity in the left corona radiata and right corpus callosum, and with both axial and radial diffusivity in the left corona radiata. The white matter integrity in these tracts (except the corpus callosum) showed no correlation with cognitive or other gait measures, supporting the specificity of those abnormalities to freezing of gait. CONCLUSION: Divergent pathological lesions involved neural circuits composed of the cerebral cortex, basal ganglia and brainstem, suggesting that freezing of gait has a multifactorial nature

    A Time- and Cost-Saving Method of Producing Rat Polyclonal Antibodies

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    Producing antibodies usually takes more than three months. In the present study, we introduce a faster way of producing polyclonal antibodies based on preparation of the recombinant oligopeptide as antigen followed by immunization of rats. Using this method, we produced antisera against two mouse proteins: ERGIC-53 and c-Kit. An expression vector ligated with a pair of complementary synthetic oligodeoxyribonucleotides encoding the protein was introduced into bacteria, and the recombinant oligopeptide fused with the carrier protein glutathione-S-transferase was purified. Wistar rats were immunized by injecting the emulsified antigen subcutaneously into the hind footpads, followed by a booster injection ­after 2 weeks. One week after the booster, the sera were collected and examined for the antibody titer by immunohistochemistry. Antisera with 1600-fold titer at the maximum were obtained for both antigens and confirmed for their specificity by Western blotting. Anti-­ERGIC-53 antisera recognized acinar cells in the sublingual gland, and anti-c-Kit antisera recognized spermatogenic and Leydig cells in the testis. These antisera were applicable to fluorescent double immunostaining with mouse monoclonal or rabbit polyclonal antibodies. Consequently, this method enabled us to produce specific rat polyclonal antisera available for immunohistochemistry in less than one month at a relatively low cost
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