2,220 research outputs found

    Three novel beta-galactosidase gene mutations in Han Chinese patients with GM1 gangliosidosis are correlated with disease severity

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    <p>Abstract</p> <p>Background</p> <p>GM1 gangliosidosis (GM1) is an autosomal recessive lysosomal storage disease caused by deficiency of acid beta-galactosidase (GLB1; EC3.2.1.23). Here, we identify three novel mutations in the GLB1 gene from two Han Chinese patients with GM1 that appear correlated with clinical phenotype.</p> <p>Methods</p> <p>One of the two Han Chinese patients with GM1 presented with the juvenile form, and the other with the infantile form with cardiac involvement. Sequencing of the entire GLB1 gene revealed three novel mutations (p.H102 D, p.G494V, c.495_497delTCT), which were absent in 94 normal controls. Transient expression of cDNA encoding these variants was performed in COS-1 cells to evaluate β-galactosidase activities.</p> <p>Results</p> <p>The first case (patient 1) with the juvenile form contained two missense mutations, p.H102 D and p.A301V. Patient 2 diagnosed with the infantile form of the disease with cardiac involvement was compound heterozygous for p.G494V and c.495_497delTCT mutations. All mutant beta-galactosidases exhibited significantly reduced activity (12%, 0%, 0%, and 0% for p.H102 D, p.A301V, p.G494V, and c.495_497delTCT), compared with the wild-type beta-galactosidase cDNA clone. The mutations identified in patient 2 with cardiomyopathy were localized in the GLB1 gene region common to both lysosomal beta-galactosidase and elastin binding protein (EBP), and caused a deletion in the elastin-binding domain of EBP.</p> <p>Conclusions</p> <p>All four mutations identified in Han Chinese patients induce significant suppression of β-galactosidase activity, correlating with severity of disease and presence of cardiomyopathy.</p

    Osteoblast-Specific Transcription Factor Osterix Increases Vitamin D Receptor Gene Expression in Osteoblasts

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    Osterix (Osx) is an osteoblast-specific transcription factor required for osteoblast differentiation from mesenchymal stem cells. In Osx knock-out mice, no bone formation occurs. The vitamin D receptor (VDR) is a member of the nuclear hormone receptor superfamily that regulates target gene transcription to ensure appropriate control of calcium homeostasis and bone development. Here, we provide several lines of evidence that show that the VDR gene is a target for transcriptional regulation by Osx in osteoblasts. For example, calvaria obtained from Osx-null embryos displayed dramatic reductions in VDR expression compared to wild-type calvaria. Stable overexpression of Osx stimulated VDR expression in C2C12 mesenchymal cells. Inhibition of Osx expression by siRNA led to downregulation of VDR. In contrast, Osx levels remained unchanged in osteoblasts in VDR-null mice. Mechanistic approaches using transient transfection assays showed that Osx directly activated a 1 kb fragment of the VDR promoter in a dose-dependent manner. To define the region of the VDR promoter that was responsive to Osx, a series of VDR promoter deletion mutants were examined and the minimal Osx-responsive region was refined to the proximal 120 bp of the VDR promoter. Additional point mutants were used to identify two GC-rich regions that were responsible for VDR promoter activation by Osx. Chromatin immunoprecipitation assays demonstrated that endogenous Osx was associated with the native VDR promoter in primary osteoblasts in vivo. Cumulatively, these data strongly support a direct regulatory role for Osx in VDR gene expression. They further provide new insight into potential mechanisms and pathways that Osx controls in osteoblasts and during the process of osteoblastic cell differentiation

    Triple-cation perovskite solar cells fabricated by hybrid PVD/blade coating process using green solvents

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    The scalability of highly efficient organic-inorganic perovskite solar cells (PSCs) is one of the remaining challenges of solar module manufacturing. Various scalable methods have been explored to strive for uniform perovskite films of high crystal quality on large-area substrates. However, each of these methods have individual drawbacks, limiting the successful commercialization of perovskite photovoltaics. Here, we report a fully scalable hybrid process, which combines vapor- and solution-based techniques to deposit high quality uniform perovskite films on large-area substrates. This two-step process does not use toxic solvents, and it further allows facile implementation of passivation strategies and additives. We fabricated PSCs based on this process and used blade coating to deposit both charge transporting layers (SnO2 and Spiro-OMeTAD) without hazardous solvents in ambient air. The fabricated PSCs have yielded open-circuit voltage up to 1.16 V and power conversion efficiency of 18.7 % with good uniformity on 5 cm x 5 cm substrates

    CAPIH: A Web interface for comparative analyses and visualization of host-HIV protein-protein interactions

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    <p>Abstract</p> <p>Background</p> <p>The Human Immunodeficiency Virus type one (HIV-1) is the major causing pathogen of the Acquired Immune Deficiency Syndrome (AIDS). A large number of HIV-1-related studies are based on three non-human model animals: chimpanzee, rhesus macaque, and mouse. However, the differences in host-HIV-1 interactions between human and these model organisms have remained unexplored.</p> <p>Description</p> <p>Here we present CAPIH (Comparative Analysis of Protein Interactions for HIV-1), the first web-based interface to provide comparative information between human and the three model organisms in the context of host-HIV-1 protein interactions. CAPIH identifies genetic changes that occur in HIV-1-interacting host proteins. In a total of 1,370 orthologous protein sets, CAPIH identifies ~86,000 amino acid substitutions, ~21,000 insertions/deletions, and ~33,000 potential post-translational modifications that occur only in one of the four compared species. CAPIH also provides an interactive interface to display the host-HIV-1 protein interaction networks, the presence/absence of orthologous proteins in the model organisms in the networks, the genetic changes that occur in the protein nodes, and the functional domains and potential protein interaction hot sites that may be affected by the genetic changes. The CAPIH interface is freely accessible at <url>http://bioinfo-dbb.nhri.org.tw/capih</url>.</p> <p>Conclusion</p> <p>CAPIH exemplifies that large divergences exist in disease-associated proteins between human and the model animals. Since all of the newly developed medications must be tested in model animals before entering clinical trials, it is advisable that comparative analyses be performed to ensure proper translations of animal-based studies. In the case of AIDS, the host-HIV-1 protein interactions apparently have differed to a great extent among the compared species. An integrated protein network comparison among the four species will probably shed new lights on AIDS studies.</p

    Liposomes prolong the therapeutic effect of anti-asthmatic medication via pulmonary delivery

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    Xiaoyu Chen, Wenhua Huang, Blenda Chi Kwan Wong, Linlin Yin, Yuen Fan Wong, Min Xu, Zhijun YangSchool of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong KongPurpose: The main objective of this study was to develop a novel aerosolized liposome formulation for pulmonary delivery of anti-asthmatic medication and to explore the relationship between the bioavailability and anti-asthmatic efficacy of such a formulation. Asthma treatment usually requires frequent administration of medication for sustained bronchodilating response. Liposomes are known for their capability for sustained drug release and thus would be a suitable delivery system for anti-asthmatic medication for prolonged therapeutic effect. Salbutamol sulfate (SBS) was chosen as the model drug in this study because of its high water solubility and fast absorption after administration.Methods: SBS was efficiently encapsulated into liposomes by the vesicular phospholipid gel technique. SBS permeability across the pulmonary membrane of an Asian toad was determined by in vitro study. Intratracheal administration of liposomes labeled with the fluorescent dye 1,1&amp;#39;-dioctadecyltetramethyl indotricarbocyanine iodide (DiR) in a rat model was assessed by a small animal imaging system and pharmacokinetic analysis. Pharmacodynamic analysis was performed in guinea pigs using the Konzett&amp;ndash;R&amp;ouml;ssler method.Results: SBS was efficiently encapsulated into liposomes with encapsulation efficiency as high as 70%. The particle size of the SBS liposome suspension was approximately 57 &amp;plusmn; 21 nm. In the in vitro study of permeability across the pulmonary membrane of Asian toads, SBS from liposomes demonstrated a slower transport rate compared to free SBS solution. Pulmonary delivery of liposomes in a rat model showed that the liposomes were effectively distributed in the respiratory tract and lungs, and that the release of SBS from liposomes was sustained for at least 48 hours. Pharmacodynamic analysis in a guinea pig model showed that the anti-asthmatic effect of SBS liposomes persisted for up to 18 hours, whereas that of free SBS solution was less than 8 hours.Conclusion: The overall results demonstrated that liposomes could increase the concentration and retention time of SBS in the lungs and therefore prolong its therapeutic effect.Keywords: salbutamol sulfate, asthma, intratracheal administration, sustained releas

    Discovering Chromatin Motifs using FAIRE Sequencing and the Human Diploid Genome

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    Background: Specific chromatin structures are associated with active or inactive gene transcription. The gene regulatory elements are intrinsically dynamic and alternate between inactive and active states through the recruitment of DNA binding proteins, such as chromatin-remodeling proteins. Results: We developed a unique genome-wide method to discover DNA motifs associated with chromatin accessibility using formaldehyde-assisted isolation of regulatory elements with high-throughput sequencing (FAIRE-seq). We aligned the FAIRE-seq reads to the GM12878 diploid genome and subsequently identified differential chromatin-state regions (DCSRs) using heterozygous SNPs. The DCSR pairs represent the locations of imbalances of chromatin accessibility between alleles and are ideal to reveal chromatin motifs that may directly modulate chromatin accessibility. In this study, we used DNA 6-10mer sequences to interrogate all DCSRs, and subsequently discovered conserved chromatin motifs with significant changes in the occurrence frequency. To investigate their likely roles in biology, we studied the annotated protein associated with each of the top ten chromatin motifs genome-wide, in the intergenic regions and in genes, respectively. As a result, we found that most of these annotated motifs are associated with chromatin remodeling, reflecting their significance in biology. Conclusions: Our method is the first one using fully phased diploid genome and FAIRE-seq to discover motifs associated with chromatin accessibility. Our results were collected to construct the first chromatin motif database (CMD), providing the potential DNA motifs recognized by chromatin-remodeling proteins and is freely available at http://syslab.nchu.edu.tw/chromatin

    The value of a novel percutaneous lung puncture clamp biopsy technique in the diagnosis of pulmonary nodules

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    Abstract Background: Computed tomography-guided percutaneous lung biopsy is a crucial method to determine pulmonary anomalies, and is highly accurate in detecting evidence of malignancies, allowing medical practitioners to identify the stage of malignancy and thus help to plan the treatment regimens of patients.Objective: To explore the clinical application of a new computed tomography-guided percutaneous lung puncture clamp biopsy technique in the diagnosis of pulmonary nodules, characterized by ground-glass opacity on chest computed tomography images.Methods: A unique instrument named ‘combined percutaneous lung biopsy forceps’, consisting of a biopsy forceps, a 15-gauge coaxial needle and needle core, was designed. The new tool was used to obtain specimens in nine patients with pulmonary ground-glass opacity. The specimen volumes and the safety of using the instrument were measured. The samples obtained were also assessed to see if they were sufficient for conducting histological tests.Result: Samples were obtained in all nine patients – a success rate of 100%. Consistently, the volume of each specimen was sufficient to make a histological diagnosis. No serious complications, such as pneumothorax – primary spontaneous pneumothorax or secondary spontaneous pneumothorax – occurred during the biopsy.Conclusions: The application of this new tool in obtaining tissue specimens in patients with pulmonary ground-glass opacity under the guidance of chest computed tomography was invaluable in terms of its high accuracy and safety. Moreover, its effect was better compared to using a fine-needle aspiration biopsy or a cutting-needle biopsy. Therefore, this instrument can be used for histological diagnosis. [Ethiop. J. Health Dev. 2021; 35(2):85-90]Key words: Ground-glass opacity; percutaneous lung puncture clamp biopsy; fine-needle aspiration biopsy; cutting-needle biops
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