Adv Healthc Mater
January 2023
Hydrogel-based drug delivery systems typically aim to release drugs locally to tissue in an extended manner. Tissue adhesive alginate-polyacrylamide tough hydrogels are recently demonstrated to serve as an extended-release system for the corticosteroid triamcinolone acetonide. Here, the stimuli-responsive controlled release of triamcinolone acetonide from the alginate-polyacrylamide tough hydrogel drug delivery systems (TADDS) and evolving new approaches to combine alginate-polyacrylamide tough hydrogel with drug-loaded nano and microparticles, generating composite TADDS is described.
View Article and Find Full Text PDFBackground: We evaluated the effects of sleep-study guided multidisciplinary therapy (SGMT) of obstructive sleep apnoea (OSA) in patients presenting with acute coronary syndrome.
Methods: Eligible patients were randomized into (1) SGMT, comprised a sleep study during the index admission and continuous positive airway pressure and behavioral therapy for those with at least mild OSA or (2) standard therapy. The primary end point was the change in the plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) level from baseline to the 7-month follow-up.
The significance of intracellular ApA levels over immune activity of dendritic cells (DCs) has been studied in Nudt2/CD11c-cre mice. The transgenic mice have been generated by crossing floxed NUDT2 gene mice with DC marker CD11c recombinase (cre) mice. The DCs derived from these mice have higher levels of ApA (≈30-fold) compared with those derived from Nudt2 mice.
View Article and Find Full Text PDFObstructive sleep apnea (OSA) is an emerging risk marker for acute coronary syndrome (ACS). This randomized trial aims to determine the effects of sleep study-guided multidisciplinary therapy (SGMT) comprising overnight sleep study, continuous positive airway pressure, and behavioral therapy for OSA during the subacute phase of ACS. We hypothesize that SGMT will reduce (1) the plasma levels of N-terminal pro brain natriuretic peptide and suppression of tumorigenicity 2; (2) the estimated 10-year risk of cardiovascular mortality as measured by the European Systematic Coronary Risk Evaluation (SCORE) algorithm; and (3) the cardiovascular event rate during a 3-year follow-up, compared with standard therapy.
View Article and Find Full Text PDFThere are several selection markers which are suitable for generating stably transfected Chinese hamster ovary (CHO) cell lines. Due to their different modes of action, each selection marker has its own optimal selection stringency in different host cells for obtaining high productivity. Using an internal ribosome entry site (IRES)-mediated tricistronic vector and a set of IRES variants with different strengths, the expression of five antibiotics resistance genes (ARGs) in CHO-K1 cells and dihydrofolate reductase (DHFR) in CHO DG44 cells is optimized to enhance the stringency of selection for high producing cells.
View Article and Find Full Text PDFJ Stroke Cerebrovasc Dis
October 2017
Objective: The aim of this study was to evaluate the effectiveness of mechanical aspiration thrombectomy (MAT) in patients with acute ischemic stroke from calcified cerebral emboli.
Methods: Procedural results were reviewed for acute stroke patients with clinically neurological deficits who underwent recanalization from October 2012 through September 2015. Initial imaging studies and cerebral angiography were analyzed.
Background: Methylated CpG dinucleotides in promoters are associated with the loss of gene expression in recombinant Chinese hamster ovary (CHO) cells during large-scale commercial manufacturing. We evaluated a promoter devoid of CpG dinucleotides, CpGfree, in parallel with a similar CpG containing promoter, CpGrich, for their ability to maintain the expression of recombinant enhanced green fluorescent protein (EGFP) after 8 weeks of culturing.
Results: While the promoters gave similar transient expression levels, CpGfree clones had significantly higher average stable expression possibly due to increased resistance to early silencing during integration into the chromosome.
Maintaining high gene expression level during long-term culture is critical when producing therapeutic recombinant proteins using mammalian cells. Transcriptional silencing of promoters, most likely due to epigenetic events such as DNA methylation and histone modifications, is one of the major mechanisms causing production instability. Previous studies demonstrated that the core CpG island element (IE) from the hamster adenine phosphoribosyltransferase gene is effective to prevent DNA methylation.
View Article and Find Full Text PDFPlasmodium vivax merozoites only invade reticulocytes, a minor though heterogeneous population of red blood cell precursors that can be graded by levels of transferrin receptor (CD71) expression. The development of a protocol that allows sorting reticulocytes into defined developmental stages and a robust ex vivo P vivax invasion assay has made it possible for the first time to investigate the fine-scale invasion preference of P vivax merozoites. Surprisingly, it was the immature reticulocytes (CD71(+)) that are generally restricted to the bone marrow that were preferentially invaded, whereas older reticulocytes (CD71(-)), principally found in the peripheral blood, were rarely invaded.
View Article and Find Full Text PDFThe human cytomegalovirus promoter (hCMV) is susceptible to gene silencing in CHO cells, most likely due to epigenetic events, such as DNA methylation and histone modifications. The core CpG island element (IE) from the hamster adenine phosphoribosyltransferase gene has been shown to prevent DNA methylation. A set of modified hCMV promoters was developed by inserting one or two copies of IE in either forward or reverse orientations either upstream of the hCMV enhancer, between the enhancer and core promoter (CP), or downstream of the CP.
View Article and Find Full Text PDFA set of mutated Encephalomyocarditis virus (EMCV) internal ribosome entry site (IRES) elements with varying strengths is generated by mutating the translation initiation codons of 10(th), 11(th), and 12(th) AUG to non-AUG triplets. They are able to control the relative expression of multiple genes over a wide range in mammalian cells in both transient and stable transfections. The relative strength of each IRES mutant remains similar in different mammalian cell lines and is not gene specific.
View Article and Find Full Text PDFImmunoglobulin G (IgG), the most common class of commercial monoclonal antibodies (mAbs), exists as multimers of two identical light chains (LC) and two identical heavy chains (HC) assembled together by disulfide bridges. Due to the kinetics of mAb assembly, it is suggested that expression of LC and HC in equal amounts is not optimal for IgG production. We designed a set of vectors using internal ribosome entry site (IRES) elements to control LC and HC expression.
View Article and Find Full Text PDFChikungunya virus (CHIKV) is a mosquito-borne arthralgia arbovirus that is reemergent in sub-Saharan Africa and Southeast Asia. CHIKV infection has been shown to be self-limiting, but the molecular mechanisms of the innate immune response that control CHIKV replication remain undefined. Here, longitudinal transcriptional analyses of PBMCs from a cohort of CHIKV-infected patients revealed that type I IFNs controlled CHIKV infection via RSAD2 (which encodes viperin), an enigmatic multifunctional IFN-stimulated gene (ISG).
View Article and Find Full Text PDFNuclear factor of activated T cells (NFAT) comprises a family of transcription factors that regulate T cell development, activation and differentiation. NFAT signalling can also mediate granulocyte and dendritic cell (DC) activation, but it is unknown whether NFAT influences their development from progenitors. Here, we report a novel role for calcineurin/NFAT signalling as a negative regulator of myeloid haematopoiesis.
View Article and Find Full Text PDFChikungunya virus (CHIKV) is an alphavirus responsible for numerous epidemics throughout Africa and Asia, causing infectious arthritis and reportedly linked with fatal infections in newborns and elderly. Previous studies in animal models indicate that humoral immunity can protect against CHIKV infection, but despite the potential efficacy of B-cell-driven intervention strategies, there are no virus-specific vaccines or therapies currently available. In addition, CHIKV has been reported to elicit long-lasting virus-specific IgM in humans, and to establish long-term persistence in non-human primates, suggesting that the virus might evade immune defenses to establish chronic infections in man.
View Article and Find Full Text PDFCurrently, there are no reliable RBC invasion assays to guide the discovery of vaccines against Plasmodium vivax, the most prevalent malaria parasite in Asia and South America. Here we describe a protocol for an ex vivo P vivax invasion assay that can be easily deployed in laboratories located in endemic countries. The assay is based on mixing enriched cord blood reticulocytes with matured, trypsin-treated P vivax schizonts concentrated from clinical isolates.
View Article and Find Full Text PDFThe Cdc42 effector IRSp53 is a strong inducer of filopodia formation and consists of an Src homology domain 3 (SH3), a potential WW-binding motif, a partial-Cdc42/Rac interacting binding region motif, and an Inverse-Bin-Amphiphysins-Rvs (I-BAR) domain. We show that IRSp53 interacts directly with neuronal Wiskott-Aldrich syndrome protein (N-WASP) via its SH3 domain and furthermore that N-WASP is required for filopodia formation as IRSp53 failed to induce filopodia formation in N-WASP knock-out (KO) fibroblasts. IRSp53-induced filopodia formation can be reconstituted in N-WASP KO fibroblasts by full-length N-WASP, by N-WASPDeltaWA (a mutant unable to activate the Arp2/3 complex), and by N-WASPH208D (a mutant unable to bind Cdc42).
View Article and Find Full Text PDFHox genes in vertebrates are clustered, and the organization of the clusters has been highly conserved during evolution. The conservation of Hox clusters has been attributed to enhancers located within and outside the Hox clusters that are essential for the coordinated "temporal" and "spatial" expression patterns of Hox genes in developing embryos. To identify evolutionarily conserved regulatory elements within and outside the Hox clusters, we obtained contiguous sequences for the conserved syntenic blocks from the seven Hox loci in fugu and carried out a systematic search for conserved noncoding sequences (CNS) in the human, mouse, and fugu Hox loci.
View Article and Find Full Text PDFWith about 24,000 extant species, teleosts are the largest group of vertebrates. They constitute more than 99% of the ray-finned fishes (Actinopterygii) that diverged from the lobe-finned fish lineage (Sarcopterygii) about 450 MYA. Although the role of genome duplication in the evolution of vertebrates is now established, its role in structuring the teleost genomes has been controversial.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
February 2003
The Hox genes encode transcription factors that play a key role in specifying body plans of metazoans. They are organized into clusters that contain up to 13 paralogue group members. The complex morphology of vertebrates has been attributed to the duplication of Hox clusters during vertebrate evolution.
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