Search results for "POLYMER"

Bifunctional poly(acrylamide) hydrogels through orthogonal coupling chemistries

2019

Biomaterials for cell culture allowing simple and quantitative presentation of instructive cues enable rationalization of the interplay between cells and their surrounding microenvironment. Poly(acrylamide) (PAAm) hydrogels are popular 2D-model substrates for this purpose. However, quantitative and reproducible biofunctionalization of PAAm hydrogels with multiple ligands in a trustable, controlled, and independent fashion is not trivial. Here, we describe a method for bifunctional modification of PAAm hydrogels with thiol- and amine- containing biomolecules with controlled densities in an independent, orthogonal manner. We developed copolymer networks of AAm with 9% acrylic acid and 2% N-(4…

Hybrid Biopolymer and Lipid Nanoparticles with Improved Transfection Efficacy for mRNA

2020

Cells 9(9), 2034 (1-19) (2020). doi:10.3390/cells9092034

Engineering of a DNA Polymerase for Direct m6A Sequencing

2017

Methods for the detection of RNA modifications are of fundamental importance for advancing epitranscriptomics. N6-methyladenosine (m6A) is the most abundant RNA modification in mammalian mRNA and is involved in the regulation of gene expression. Current detection techniques are laborious and rely on antibody-based enrichment of m6A-containing RNA prior to sequencing, since m6A modifications are generally "erased" during reverse transcription (RT). To overcome the drawbacks associated with indirect detection, we aimed to generate novel DNA polymerase variants for direct m6A sequencing. Therefore, we developed a screen to evolve an RT-active KlenTaq DNA polymerase variant that sets a mark for…

Genome-Wide Estimation of the Spontaneous Mutation Rate of Human Adenovirus 5 by High-Fidelity Deep Sequencing

2016

Rates of spontaneous mutation determine the ability of viruses to evolve, infect new hosts, evade immunity and undergo drug resistance. Contrarily to RNA viruses, few mutation rate estimates have been obtained for DNA viruses, because their high replication fidelity implies that new mutations typically fall below the detection limits of Sanger and standard next-generation sequencing. Here, we have used a recently developed high-fidelity deep sequencing technique (Duplex Sequencing) to score spontaneous mutations in human adenovirus 5 under conditions of minimal selection. Based on >200 single-base spontaneous mutations detected throughout the entire viral genome, we infer an average mutatio…

TLR1 and PRKAA1 Gene Polymorphisms in the Development of Atrophic Gastritis and Gastric Cancer.

2018

Background & Aims: Previous genome-wide association studies showed that genetic polymorphisms in toll-like receptor 1 (TLR1) and protein kinase AMP-activated alpha 1 catalytic subunit (PRKAA1) genes were associated with gastric cancer (GC) or increased Helicobacter pylori (H. pylori) infection susceptibility. The aim of this study was to evaluate the association between TLR1 and PRKAA1 genes polymorphisms and H.pylori infection, atrophic gastritis (AG) or GC in the European population.Methods: Single-nucleotide polymorphisms (SNPs) were analysed in 511 controls, 340 AG patients and 327 GC patients. TLR1 C>T (rs4833095) and PRKAA1 C>T (rs13361707) were genotyped by the real-time po…

Re-examining the relationship between active cytomegalovirus (CMV) infection and acute graft-versus-host disease in allogeneic stem cell transplant r…

2015

Hepatitis delta virus infection in a large cohort of chronic hepatitis B patients in Ethiopia.

2017

Background Hepatitis D Virus (HDV)-infection is associated with a more severe outcome in patients with chronic hepatitis B (CHB); however, little is known about the presence of HDV in sub-Saharan Africa. We aimed to determine the prevalence of HDV-infection, as well as its clinical, biological and virological characteristics, in a large CHB cohort in Ethiopia. Methods In total, 1267 HIV-negative CHB patients at St. Paul's Hospital Millennium Medical College in Addis Ababa were screened for anti-HDV antibodies using ELISA assays. Confirmed positive samples were further tested for HDV RNA using a consensus commercial real-time RT-PCR assay. HDV genotypes were also determined for RNA positive …

Fungal DNA is present in tissue specimens of patients with chronic rhinosinusitis.

2004

Background It has been postulated that fungal organisms might represent the immunologic target initiating and maintaining the disease process in patients with chronic rhinosinusitis (CRS). The presence of fungi in nasal mucus has been established by different groups, but so far it has not been shown how the immune system could even recognize such extramucosal—extracorporal—fungal targets. The aim of this study was to determine whether fungal DNA is present in tissue specimens taken from patients with polypoid CRS. Methods Twenty-seven surgical specimens were collected from patients suffering from CRS. Fifteen surgical specimens from healthy ethmoidal mucosa served as controls. A second set …

The Amount of Melanin Influences p16 Loss in Spitzoid Melanocytic Lesions: Correlation With CDKN2A Status by FISH and MLPA.

2019

AIMS The risk assessment of spitzoid lesions is one of the most difficult challenges in dermatopathology practice. In this regard, the loss of p16 expression and the homozygous deletion of CDKN2A, have been pointed in the literature as reliable indicators of high risk. However, these findings are poorly reproducible, and the molecular bases underlying the loss of p16 expression remain unclear. We aimed to identify the underlying events causing loss of CDKN2A/p16 in spitzoid tumors. MATERIALS AND METHODS We evaluated the immunohistochemical expression of p16, and the presence of CDKN2A genetic alterations detected through fluorescence in situ hybridization (FISH) and multiplex ligation-depen…

Centenarians Overexpress Pluripotency-Related Genes.

2018

Abstract Human mesenchymal cells can become pluripotent by the addition of Yamanaka factors OCT3/4, SOX2, c-MYC, KLF4. We have recently reported that centenarians overexpress BCL-xL, which has been shown to improve pluripotency; thus, we aimed to determine the expression of pluripotency-related genes in centenarians. We recruited 22 young, 32 octogenarian, and 47 centenarian individuals and determined the mRNA expression of Yamanaka factors and other stemness-related cell surface marker genes (VIM, BMP4, NCAM, BMPR2) in peripheral blood mononuclear cells by reverse transcription polymerase chain reaction. We found that centenarians overexpress OCT3/4, SOX2, c-MYC, VIM, BMP4, NCAM, and BMPR2…