Search results for "ENZYME"
showing 10 items of 3924 documents
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…
Polyphosphate as a donor of high-energy phosphate for the synthesis of ADP and ATP.
2017
Here, we studied the potential role of inorganic polyphosphate (polyP) as an energy source for ADP and ATP formation in the extracellular space. In SaOS-2 cells, we show that matrix vesicles are released into the extracellular space after incubation with polyP. These vesicles contain both alkaline phosphatase (ALP) and adenylate kinase (AK) activities (mediated by ALPL and AK1 enzymes). Both enzymes translocate to the cell membrane in response to polyP. To distinguish the process(es) of AMP and ADP formation during ALP hydrolysis from the ATP generated via the AK reaction, inhibition studies with the AK inhibitor A(5')P5(5')A were performed. We found that ADP formation in the extracellular …
Cholesterol Content in Human Milk during Lactation: A Comparative Study of Enzymatic and Chromatographic Methods.
2018
This study validates a gas chromatography (GC) method for determining the sterol profile of human milk (HM) and compares it with an enzymatic-spectrophotometric (E-S) method. Good linearity ( r > 0.97) and low limits of detection and quantification were obtained with the GC method (<1.8 and <6 μg/100 g of HM, respectively). Suitable intra- and interassay precisions (all <18%) and satisfactory recovery percentages (80-109%) were obtained for both methods. In addition, both methodologies were used to assess cholesterol evolution in HM during lactation, showing a 50% decrease at 6 months versus colostrum. The E-S method overestimated cholesterol content by <20% versus the GC method. The result…
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 …
Clinical course of sly syndrome (mucopolysaccharidosis type VII).
2016
WOS: 000377110800007
ADMA and arginine derivatives in relation to non-invasive vascular function in the general population.
2015
Nitric oxide produced from l-arginine is central to vascular homeostasis. Little is known about the relationship between arginine derivatives including asymmetric dimethylarginine (ADMA) and non-invasive vascular function measures in the general population.In 5000 individuals (median age 56; 25th/75th percentile: 46, 65; 49% women) taking part in the population-based Gutenberg Health Study (Mainz area, Germany), we measured the relationship between the arginine derivatives asymmetric dimethylarginine (ADMA), N-monomethyl l-arginine (NMMA), symmetric dimethylarginine (SDMA) and l-arginine with flow-mediated dilation (FMD) and peripheral arterial tonometry (PAT). Weak bivariate correlations w…
The JAK2 pathway is activated in idiopathic pulmonary fibrosis
2018
Background: Idiopathic pulmonary fibrosis (IPF) is the most rapidly progressive and fatal fibrotic disorder, with no curative therapies. The signal transducer and activator of transcription 3 (STAT3) protein is activated in lung fibroblasts and alveolar type II cells (ATII), thereby contributing to lung fibrosis in IPF. Although activation of Janus kinase 2 (JAK2) has been implicated in proliferative disorders, its role in IPF is unknown. The aim of this study was to analyze JAK2 activation in IPF, and to determine whether JAK2/STAT3 inhibition is a potential therapeutic strategy for this disease. Methods and results: JAK2/p-JAK2 and STAT3/pSTAT3 expression was evaluated using quantitative …
Boosting effect of IL-7 in interferon gamma release assays to diagnose Mycobacterium tuberculosis infection.
2018
BACKGROUND A quarter of the world's population is estimated to be infected with Myobacterium tuberculosis (Mtb). Infection is detected by immune response to M. tuberculosis antigens using either tuberculin skin test (TST) and interferon gamma release (IGRA's), tests which have low sensitivity in immunocompromised. IL-7 is an important cytokine for T-cell function with potential to augment cytokine release in in-vitro assays. This study aimed to determine whether the addition of IL-7 in interferon-gamma release assays (IGRAs) improves its diagnostic performance of Mtb infection. METHODS 44 cases with confirmed TB and 45 household contacts without TB were recruited and 1ml of blood was stimul…
Impact of immunosuppressive therapy on therapy-neutralizing antibodies in transplanted patients with Fabry disease.
2017
Background Inhibitory antibodies towards enzyme replacement therapy (ERT) are associated with disease progression and poor outcome in affected male patients with lysosomal disorders such as Fabry disease (FD). However, little is known about the impact of immunosuppressive therapy on ERT inhibition in these patients with FD. Methods In this retrospective study, we investigated the effect of long-term immunosuppression on ERT inhibition in male patients with FD (n = 26) receiving immunosuppressive therapy due to kidney (n = 24) or heart (n = 2) transplantation. Results No ERT-naive transplanted patient (n = 8) developed antibodies within follow-up (80 ±72 months) after ERT initiation. Seven (…
Effect of gene-gene and gene-environment interactions associated with antituberculosis drug-induced hepatotoxicity.
2017
This study evaluated the association between environmental factors and genetic variations in enzymes that metabolize antituberculosis (anti-TB) drugs [arylamine N-acetyltransferase 2, cytochrome P450 2E1 (CYP2E1), glutathione S-transferase theta 1 (GSTT1), and glutathione S-transferase mu 1] with antituberculosis drug-induced hepatotoxicity (ATDH). We also investigated the potential gene-gene and gene-environment interactions as well as their association with ATDH development in a population of hospitalized TB patients from Buenos Aires.We investigated 364 TB patients who received anti-TB drugs. Physicians collected demographic and clinical data to identify environmental risk factors for AT…