734 research outputs found

    Repression of FLOWERING LOCUS T Chromatin by Functionally Redundant Histone H3 Lysine 4 Demethylases in Arabidopsis

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    FLOWERING LOCUS T (FT) plays a key role as a mobile floral induction signal that initiates the floral transition. Therefore, precise control of FT expression is critical for the reproductive success of flowering plants. Coexistence of bivalent histone H3 lysine 27 trimethylation (H3K27me3) and H3K4me3 marks at the FT locus and the role of H3K27me3 as a strong FT repression mechanism in Arabidopsis have been reported. However, the role of an active mark, H3K4me3, in FT regulation has not been addressed, nor have the components affecting this mark been identified. Mutations in Arabidopsis thaliana Jumonji4 (AtJmj4) and EARLY FLOWERING6 (ELF6), two Arabidopsis genes encoding Jumonji (Jmj) family proteins, caused FT-dependent, additive early flowering correlated with increased expression of FT mRNA and increased H3K4me3 levels within FT chromatin. Purified recombinant AtJmj4 protein possesses specific demethylase activity for mono-, di-, and trimethylated H3K4. Tagged AtJmj4 and ELF6 proteins associate directly with the FT transcription initiation region, a region where the H3K4me3 levels were increased most significantly in the mutants. Thus, our study demonstrates the roles of AtJmj4 and ELF6 as H3K4 demethylases directly repressing FT chromatin and preventing precocious flowering in Arabidopsis

    Cutaneous Schwannoma Presented as a Pedunculated Protruding Mass

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    Schwannoma is a benign neoplasm of the nerve sheath origin. It arises from the nerve sheath of large peripheral or cranial nerves and occurs at the level of the subcutaneous fat layer or deeper layer. Cutaneous schwannoma occurs more superficially and usually presents as a solitary dermal or subcutaneous nodule. We describe a case of cutaneous schwannoma that presented as an erythematous pedunculated protruding mass on the left flank of a 19-year-old female. It was clinically diagnosed as a granuloma pyogenicum. Shaving biopsy was conducted and histological examination revealed an encapsulated tumor mass containing dense, spindle-shaped cells whose nuclei are arranged back to back representing Verocay body, and a diagnosis of schwannoma was made. This is an unusual case of cutaneous schwannoma that presented as a pedunculated protruding mass

    Infantile Marfan syndrome in a Korean tertiary referral center

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    PurposeInfantile Marfan syndrome (MFS) is a rare congenital inheritable connective tissue disorder with poor prognosis. This study aimed to evaluate the cardiovascular manifestations and overall prognosis of infantile MFS diagnosed in a tertiary referral center in Korea.MethodsEight patients diagnosed with infantile MFS between 2004 and 2014 were retrospectively evaluated.ResultsTheir median age at the time of diagnosis was 2.5 months (range, 0โ€“20 months). The median follow-up period was 25.5 months (range, 0โ€“94 months). The median length at birth was 50.0 cm (range, 48โ€“53 cm); however, height became more prominent over time, and the patients were taller than the 97th percentile at the time of the study. None of the patients had any relevant family history. Four of the 5 patients who underwent DNA sequencing had a fibrillin 1 gene mutation. All the patients with echocardiographic data of the aortic root had a z score of >2. All had mitral and tricuspid valve prolapse, and various degrees of mitral and tricuspid regurgitation. Five patients underwent open-heart surgery, including mitral valve replacement, of whom two required multiple operations. The median age at mitral valve replacement was 28.5 months (range, 5โ€“69 months). Seven patients showed congestive heart failure before surgery or during follow-up, and required multiple anti-heart failure medications. Four patients died of heart failure at a median age of 12 months.ConclusionThe prognosis of infantile MFS is poor; thus, early diagnosis and timely cautious treatment are essential to prevent further morbidity and mortality

    Insufficiency of Laboratory Data in Reflecting Allergic Rhinitis Severity Based on the Allergic Rhinitis and Its Impact on Asthma Guideline in Korean Patients

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    Background and Objectives This retrospective study, conducted at a single tertiary medical center, aimed to investigate the correlation between the severity of allergic rhinitis (AR) based on subjective symptoms and the severity assessed through laboratory data. Methods In total, 584 patients who were diagnosed with AR by a multiple-allergen simultaneous test were included. Patients were classified into four groups according to the Allergic Rhinitis and its Impact on Asthma (ARIA) classification guideline. The visual analog scale (VAS) score for overall discomfort and laboratory parameters, including the serum total immunoglobulin E (IgE) level and peripheral blood eosinophil count, were evaluated in all patients. An analysis was conducted to examine the differences in VAS scores and laboratory findings among the four groups. Additionally, the correlations between the laboratory findings and VAS score were analyzed. Results The serum total IgE level and the percentage and count of peripheral blood eosinophils showed no significant differences among the groups. However, the VAS score for overall discomfort exhibited notable between-group differences. The average VAS score was 6.14 (95% confidence interval 5.94โ€“6.34) in the overall group. The mean scores of each group showed a noticeable increasing trend from the mild intermittent group to the mild persistent, moderate to severe intermittent, and moderate to severe persistent groups (p<0.001), although there was no clear correlation between the increase in VAS scores and laboratory parameters. Conclusion Neither the symptom-based ARIA guideline nor the VAS score correlated with the AR laboratory test measurements. The current laboratory data alone may not be sufficient to reflect the severity of AR based on subjective symptoms

    Selective Regional Loss of Cortical Synapses Lacking Presynaptic Mitochondria in the 5xFAD Mouse Model

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    Synaptic loss in Alzheimer&apos;s disease (AD) is strongly correlated with cognitive impairment. Accumulating evidence indicates that amyloid pathology leads to synaptic degeneration and mitochondrial damage in AD. However, it remains unclear whether synapses and presynaptic mitochondria are differentially affected in various cortical regions of the AD brain at the ultrastructural level. Using serial block-face scanning electron microscopy, we assessed synaptic structures in the medial prefrontal cortex (mPFC) and primary visual cortex (V1) of the 5xFAD mouse model of AD. At 6 months of age, 5xFAD mice exhibited significantly elevated levels of amyloid deposition in layer 2/3 of the mPFC but not V1. Accordingly, three-dimensional reconstruction of synaptic connectivity revealed a significant reduction in excitatory synaptic density in layer 2 of the mPFC, but not V1, of male transgenic mice. Notably, the density of synapses lacking presynaptic mitochondria was selectively decreased in the mPFC of 5xFAD mice, with no change in the density of mitochondria-containing synapses. Further classification of spines into shape categories confirmed a preferential loss of thin spines whose presynaptic boutons were largely devoid of mitochondria in the 5xFAD mPFC. Furthermore, the number of mitochondria per bouton in spared mitochondria-containing boutons was reduced in the mPFC, but not V1, of 5xFAD mice. Collectively, these results highlight region-specific vulnerability of cortical synapses to amyloid deposition and suggest that the presence of presynaptic mitochondria may affect synaptic degeneration in AD.1

    Tuning orbital-selective phase transitions in a two-dimensional Hund's correlated system

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    Hund's rule coupling (J\textit{J}) has attracted much attention recently for its role in the description of the novel quantum phases of multi orbital materials. Depending on the orbital occupancy, J\textit{J} can lead to various intriguing phases. However, experimental confirmation of the orbital occupancy dependency has been difficult as controlling the orbital degrees of freedom normally accompanies chemical inhomogeneities. Here, we demonstrate a method to investigate the role of orbital occupancy in J\textit{J} related phenomena without inducing inhomogeneities. By growing SrRuO3_3 monolayers on various substrates with symmetry-preserving interlayers, we gradually tune the crystal field splitting and thus the orbital degeneracy of the Ru \textit{t_2_g$}$ orbitals. It effectively varies the orbital occupancies of two-dimensional (2D) ruthenates. Via in-situ angle-resolved photoemission spectroscopy, we observe a progressive metal-insulator transition (MIT). It is found that the MIT occurs with orbital differentiation: concurrent opening of a band insulating gap in the $\textit{d$_x_y} band and a Mott gap in the \textit{d_xz_z_/y_y_z} bands. Our study provides an effective experimental method for investigation of orbital-selective phenomena in multi-orbital materials

    Predicting Mechanical Complications After Adult Spinal Deformity Operation Using a Machine Learning Based on Modified Global Alignment and Proportion Scoring With Body Mass Index and Bone Mineral Density

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    Objective This study aimed to create an ideal machine learning model to predict mechanical complications in adult spinal deformity (ASD) surgery based on GAPB (modified global alignment and proportion scoring with body mass index and bone mineral density) factors. Methods Between January 2009 and December 2018, 238 consecutive patients with ASD, who received at least 4-level fusions and were followed-up for โ‰ฅ2 years, were included in the study. The data were stratified into training (n=167, 70%) and test (n=71, 30%) sets and input to machine learning algorithms, including logistic regression, random forest gradient boosting system, and deep neural network. Results Body mass index, bone mineral density, the relative pelvic version score, the relative lumbar lordosis score, and the relative sagittal alignment score of the global alignment and proportion score were significantly different in the training and test sets (p<0.05) between the complication and no complication groups. In the training set, the area under receiver operating characteristics (AUROCs) for logistic regression, gradient boosting, random forest, and deep neural network were 0.871 (0.817โ€“0.925), 0.942 (0.911โ€“0.974), 1.000 (1.000โ€“1.000), and 0.947 (0.915โ€“0.980), respectively, and the accuracies were 0.784 (0.722โ€“0.847), 0.868 (0.817โ€“0.920), 1.000 (1.000โ€“1.000), and 0.856 (0.803โ€“0.909), respectively. In the test set, the AUROCs were 0.785 (0.678โ€“0.893), 0.808 (0.702โ€“0.914), 0.810 (0.710โ€“0.910), and 0.730 (0.610โ€“0.850), respectively, and the accuracies were 0.732 (0.629โ€“0.835), 0.718 (0.614โ€“0.823), 0.732 (0.629โ€“0.835), and 0.620 (0.507โ€“0.733), respectively. The random forest achieved the best predictive performance on the training and test dataset. Conclusion This study created a comprehensive model to predict mechanical complications after ASD surgery. The best prediction accuracy was 73.2% for predicting mechanical complications after ASD surgery. This information can be used to prevent mechanical complications during ASD surgery
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