386 research outputs found

    Genomic Convergence toward Diploidy in Saccharomyces cerevisiae

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    Genome size, a fundamental aspect of any organism, is subject to a variety of mutational and selection pressures. We investigated genome size evolution in haploid, diploid, and tetraploid initially isogenic lines of the yeast Saccharomyces cerevisiae. Over the course of ~1,800 generations of mitotic division, we observed convergence toward diploid DNA content in all replicate lines. This convergence was observed in both unstressful and stressful environments, although the rate of convergence was dependent on initial ploidy and evolutionary environment. Comparative genomic hybridization with microarrays revealed nearly euploid DNA content by the end of the experiment. As the vegetative life cycle of S. cerevisiae is predominantly diploid, this experiment provides evidence that genome size evolution is constrained, with selection favouring the genomic content typical of the yeast's evolutionary past

    Preventive effects of Korean red ginseng on experimentally induced colitis and colon carcinogenesis

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    © 2020 Center for Food and Biomolecules, National Taiwan UniversityKorean Red Ginseng (KRG) exerts chemopreventive effects on experimentally induced carcinogenesis through multiple mechanisms. In this study, we investigated effects of KRG on dextran sulfate sodium (DSS)-induced colitis and azoxymethane (AOM) plus DSS-induced colon carcinogenesis in mice. Male C57BL/6J mice were fed diet containing 1% KRG or a standard diet throughout the experiment. The mouse colitis was induced by administration of 3% DSS in drinking water for 1 week. DSS caused body weight loss, diarrhea, rectal bleeding and colon length shortening, and all these symptoms were ameliorated by KRG treatment. KRG inhibited DSS-induced expression of cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) by suppressing activation of nuclear factor-kappa B (NF-κB) and signal transducer and activation of transcription 3 (STAT3). In another experiment, colon carcinogenesis was initiated by single intraperitoneal injection of AOM (10 mg/kg) and promoted by 2% DSS in drinking water. KRG administration relieved the symptoms of colitis and reduced the incidence, the multiplicity and the size of colon tumor. The up-regulation of COX-2, iNOS, c-Myc and Cyclin D1 by AOM plus DSS was attenuated in KRG fed mice which was associated with suppression of NF-κB and STAT3 activation. These results suggest that KRG is a potential candidate for chemoprevention of inflammation-associated cancer in the colon.

    Background 18F-FDG uptake in positron emission mammography (PEM): Correlation with mammographic density and background parenchymal enhancement in breast MRI

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    AbstractWe aimed to determine whether background 18F-FDG uptake in positron emission mammography (PEM) was related to mammographic density or background parenchymal enhancement in breast MRI.MethodsWe studied a total of 52 patients (mean age, 50.9 years, 26 premenopausal, 26 postmenopausal) with newly diagnosed breast cancer who underwent 18F-FDG PEM (positron emission mammography), conventional mammography and breast MRI. The background mean 18F-FDG uptake value on PEM was obtained by drawing a user-defined region of interest (ROI) in a normal area of the contralateral breast. We reviewed the mammography retrospectively for overall breast density of contralateral breast according to the four-point scale (grade 1–4) of the Breast Imaging Reporting and Data System (BI-RADS) classification. The background parenchymal enhancement of breast MRI was classified as minimal, mild, moderate, or marked. All imaging findings were interpreted by two readers in consensus without knowledge of image findings of other modalities.ResultsMultiple linear regression analysis revealed a significant correlation between background 18F-FDG uptake on PEM and mammographic density after adjustment for age and menopausal status (P<0.01), but not between background 18F-FDG uptake on PEM and background parenchymal enhancement on MRI.ConclusionBackground 18F-FDG uptake on PEM significantly increases as mammographic density increases. Background parenchymal enhancement in breast MRI was not an independent predictor of the background 18F-FDG uptake on PEM unlike mammographic density

    Curcumin induces stabilization of Nrf2 protein through Keap1 cysteine modification

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    The present study was aimed to investigate the effects of curcumin, a representative chemopreventive phytochemical with pronounced antioxidant and anti-inflammatory properties, on activation of Nrf2 and expression of its target protein heme oxygenase-1 (HO-1) in mouse skin in vivo and in cultured murine epidermal cells. Treatment of mouse epidermal JB6 cells with curcumin resulted in the induction of HO-1 expression, and this was abrogated in cells transiently transfected with Nrf2 siRNA. While curcumin treatment increased protein expression of Nrf2, it did not alter the steady-state level of the Nrf2 mRNA transcript. Treatment of cells with curcumin stabilized Nrf2 by inhibiting ubiquitination and subsequent 26S proteasomal degradation of this transcription factor. Tetrahydrocurcumin, a non-electrophilic analogue of curcumin that lacks the alpha,beta-unsaturated carbonyl group, failed to induce HO-1 expression as well as nuclear translocation of Nrf2 and its binding to the antioxidant/electrophile response elements. Cells transfected with a mutant Keap1 protein in which cysteine 151 (Cys151) is replaced by serine exhibited marked reduction in curcumin-induced Nrf2 transactivation. Mass spectrometric analysis revealed that curcumin binds to Keap1 Cys151, supporting that this amino acid is a critical target for curcumin modification of Keap1, which facilitates the liberation of Nrf2. Thus, it is likely that the alpha,beta-unsaturated carbonyl moiety of curcumin is essential for its binding to Keap1 and stabilization of Nrf2 by hampering ubiquitination and proteasomal degradation.

    Funding structures for Build-to-Suit developments in Brazil: advantages and risks

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    Empreendimentos build-to-suit são aqueles em que o locador desenvolve um imóvel sob medida para o locatário, que o ocupará pelo prazo previsto em contrato. Dadas as peculiaridades desse tipo de contrato no contexto do real estate, o objetivo deste artigo é analisar as diferentes origens de recursos (fontes de funding) e a forma como eles são empregados (estruturas de funding) para desenvolver os empreendimentos, e discutir as vantagens e riscos dessas estruturas de funding do ponto de vista do empreendedor, que também é o locador. De forma a desenvolver este estudo e formatar as estruturas de funding apresentadas, parte-se de uma revisão das\ud práticas atuais do mercado imobiliário brasileiro (através de notícias veiculadas\ud na mídia e de prospectos de negócios realizados), da literatura brasileira sobre o tema e do conhecimento gerado no Grupo de Real Estate da Escola Politécnica da USP. De maneira a verificar a validade legal das soluções, é realizada uma checagem com\ud base na legislação brasileira e nas normas da Comissão de Valores Mobiliários.\ud Considera-se fontes de funding aquelas tratadas (1) como equity: capital próprio do empreendedor, capital de parceiros (e sócios) no empreendimento na forma de dinheiro ou imóveis (notadamente, o terreno onde será construído o empreendimento), ou investimento de Fundo de Investimento Imobiliário (FII); e (2) como dívida: financiamento bancário, securitização dos recebíveis de aluguéis com CRI ou debêntures. As estruturas de funding apresentadas serão combinações dessas fontes. A análise evidencia que estruturas com financiamento por securitização e emissão de CRI são as mais adequadas de forma geral para os negócios, assim como o investimento completo por FII para negócios de maior porte e nos quais o FII é proprietário direto do empreendimento. \ud Palavras-chave: real estate, build-to-suit, locação, funding, project financeBuild-to-suit real estate assets are tailor made developments for the tenant purposes, who occupies and operates the property for the duration agreed. Given the peculiarities of these contracts and the specificities of the property, this article aims at analyzing the sources of capital and how these funds are mixed and structured for the developments. The article discusses the risks and benefits of each of these funding\ud structures assuming the role of developer. In order to do this study and establish the funding structures shown, the research starts with a review of the current practices in Brazilian real estate market (based on press releases and prospects of deals), of local research papers, and will use the knowledge created at the Real Estate Research Group at Escola Politécnica at Universidade de São Paulo. Since it’s necessary to validate\ud the solutions proposed, Brazilian laws and Comissão de Valores Mobiliários (CVM) norms\ud are reviewed. Funding sources considered will be treated as (1) equity: developers own funds, partnership (via capital or real state – mainly land – investment), or Fundo de Investimento Imobiliário (Brazilian investment structure comparable to REITs); or as (2) debt: banks traditional credit lines, securitization of receivables with CRI emissions\ud , and debt bond emissions. The funding structures presented are mixes of these sources. The analysis shows that the structures best suited for this purpose are those with debt by securitization with CRI emissions, along with the complete investment by a FII but only with large emissions and having the FII as the sole owner of the real estate. \ud Keywords: real estate, build-to-suit, rent, funding, project financ

    Complete genome sequence of Mycobacterium tuberculosis K from a Korean high school outbreak, belonging to the Beijing family

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    Mycobacterium tuberculosis K, a member of the Beijing family, was first identified in 1999 as the most prevalent genotype in South Korea among clinical isolates of M. tuberculosis from high school outbreaks. M. tuberculosis K is an aerobic, non-motile, Gram-positive, and non-spore-forming rod-shaped bacillus. A transmission electron microscopy analysis displayed an abundance of lipid bodies in the cytosol. The genome of the M. tuberculosis K strain was sequenced using two independent sequencing methods (Sanger and Illumina). Here, we present the genomic features of the 4,385,518-bp-long complete genome sequence of M. tuberculosis K (one chromosome, no plasmid, and 65.59 % G + C content) and its annotation, which consists of 4194 genes (3447 genes with predicted functions), 48 RNA genes (3 rRNA and 45 tRNA) and 261 genes with peptide signals.

    Granulocytic Sarcoma in the Head and Neck: CT and MR Imaging Findings

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    ObjectivesTo evaluate characteristic computed tomography (CT) and magnetic resonance (MR) imaging findings of granulocytic sarcomas of the head and neck.MethodsThe CT (n=11) and MR (n=1) images obtained from 11 patients (7 males and 4 females; mean age, 23.5 yr; age range, 1 to 69 yr) with histologically-proven granulocytic sarcomas of the head and neck were retrospectively reviewed. Histological confirmation was done by bone marrow biopsy in 9 patients, and/or local biopsy in 4 patients. The imaging findings were analyzed with particular attention to location, size, shape, margin, bone destruction, internal architecture, pattern and degree of enhancement, and multiplicity of the lesions.ResultsThe masses were most commonly located in the orbital cavity (n=8); other locations included lymph nodes (n=5) and palatine/pharyngeal/lingual tonsils (n=3). The mass sizes varied from a mean diameter of 1.3 to 5.8 cm (average, 2.6 cm). Multiple lesions were found in 6 patients. The shapes of the tumors were ovoid in 12 patients and irregular in 4 patients. Most lesions had poorly-defined margins (13/16) and invaded adjacent bony structures (5/16). On the pre-contrast CT images, the masses were iso- (5/8) or low-density (3/8) in comparison with muscle. The MRI, which was obtained in one patient in this study, showed that the mass was iso-signal intensity on T1-weighted images and iso-signal intensity on T2-weighted images compared to the gray matter of the brain. On the post-contrast CT images, there was homogenesous (n=12) or heterogeneous (n=4) enhancement, with mild (n=10), moderate (n=4), and marked (n=2) enhancement in the solid portions of the lesions.ConclusionAlthough rare, granulocytic sarcomas arise in various locations in the head and neck area (most commonly in the orbit) in the form of well-demarcated, and mildly- and homogenously-enhancing masses with adjacent bony invasion

    Crystal structure of Helicobacter pylori MinE, a cell division topological specificity factor

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    In Gram-negative bacteria, proper placement of the FtsZ ring, mediated by nucleoid occlusion and the activities of the dynamic oscillating Min proteins MinC, MinD and MinE, is required for correct positioning of the cell division septum. MinE is a topological specificity factor that counters the activity of MinCD division inhibitor at the mid-cell division site. Its structure consists of an anti-MinCD domain and a topology specificity domain (TSD). Previous NMR analysis of truncated Escherichia coli MinE showed that the TSD domain contains a long α-helix and two anti-parallel β-strands, which mediate formation of a homodimeric α/β structure. Here we report the crystal structure of full-length Helicobacter pylori MinE and redefine its TSD based on that structure. The N-terminal region of the TSD (residues 19–26), previously defined as part of the anti-MinCD domain, forms a β-strand (βA) and participates in TSD folding. In addition, H. pylori MinE forms a dimer through the interaction of anti-parallel βA-strands. Moreover, we observed serial dimer–dimer interactions within the crystal packing, resulting in the formation of a multimeric structure. We therefore redefine the functional domain of MinE and propose that a multimeric filamentous structure is formed through anti-parallel β-strand interactions

    Chondrolipoma in the Pelvic Cavity: a Case Report

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    A chondrolipoma is an extremely rare form of a benign mesenchymal tumor containing mature cartilage and fatty tissue. Chondrolipomas may be found in almost any part of the body, particularly in the connective tissue of the breast, head and neck area, as well as in the skeletal muscle. However, to the best of our knowledge, chondrolipomas located in the pelvic cavity have not been reported. In this case report, we describe a case of a chondrolipoma in the pelvis, and show that it has its own characteristic imaging findings, which included the composition of fatty tissue and calcification in most parts, as well as some focal areas of chondroid tissue based on the CT and MR findings

    Variations of the Superficial Brachial Artery in Korean Cadavers

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    The superficial brachial artery (SBA), a branch of the axillary artery, is one of the most common arterial variations in this area. While it is more vulnerable to accidental arterial injection or injury, it could be useful for the nourishment of a medial arm skin free flap. To analyze the relationship between the SBA of axillary origin and segmental variation of the axillary artery, we dissected 304 arms of Korean cadavers. We found an SBA of axillary origin in 12.2% of cadaveric arms. Unilateral occurrence was detected in 16 cadavers and bilateral in 10. SBAs gave rise to radial and ulnar arteries in the cubital fossa (8.9%), continued in the forearm as the radial artery (2.3%), or ended in the upper arm (1.0%). The SBA ended as ulnar artery was not found in any of the cadavers. The bifurcation of the SBA into the radial and ulnar arteries, presence of an SBA that ends in the upper arm, and the lack of continuation as the ulnar artery are characteristics of SBAs in Korean cadavers
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