2,867 research outputs found
Exploring Asphodelus microcarpus as a source of xanthine oxidase inhibitors: Insights from in silico and in vitro studies
Xanthine oxidase (XO) plays a critical role in purine catabolism, catalyzing the conversion of hypoxanthine to
xanthine and xanthine to uric acid, contributing to superoxide anion production. This process is implicated in
various human diseases, particularly gout. Traditional XO inhibitors, such as allopurinol and febuxostat, while
effective, may present side effects.
Our study focuses on Asphodelus microcarpus, a plant renowned for traditional anti-inflammatory uses. Recent
investigations into its phenolic-rich flowers, notably abundant in luteolin derivatives, reveal its potential as a
natural source of XO inhibitors. In the present research, XO inhibition by an ethanolic flowers extract from
A. microcarpus is reported. In silico docking studies have highlighted luteolin derivatives as potential XO inhibitors,
and molecular dynamics support that luteolin 7-O-glucoside has the highest binding stability compared
to other compounds and controls. In vitro studies confirm that luteolin 7-O-glucoside inhibits XO more effectively
than the standard inhibitor allopurinol, with an IC50 value of 4.8 μg/mL compared to 11.5 μg/mL, respectively.
These findings underscore the potential therapeutic significance of A. microcarpus in managing conditions related
to XO activity. The research contributes valuable insights into the health-promoting properties of A. microcarpus
and its potential application in natural medicine, presenting a promising avenue for further exploration in disease
management
A failure mode and effect analysis (FMEA)-based approach for risk assessment of scientific processes in non-regulated research laboratories
AbstractNowadays, Quality Management tools such as failure mode and effect analysis (FMEA) are widely used throughout the aeronautical, automotive, software, food services, health care and many other industries to sustain and improve quality and safety. The increasing complexity of scientific research makes it more difficult to maintain all activities under control, in order to guarantee validity and reproducibility of results. Even in non-regulated research, scientists need to be supported with management tools that maximize study performance and outcomes, while facilitating the research process. Frequently, steps that involve human intervention are the weak links in the process. Risk analysis therefore gives considerable benefit to analytical validation, assessing and avoiding failures due to human error, potential imprecision in applying protocols, uncertainty in equipment function and imperfect control of materials. This paper describes in detail how FMEA methodology can be applied as a performance improvement tool in the field of non-regulated research, specifically on a basic Life Sciences research process. We chose as "pilot process" the selection of oligonucleotide aptamers for therapeutic purposes, as an example of a complex and multi-step process, suitable for technology transfer. We applied FMEA methodology, seeking every opportunity for error and its impact on process output, and then, a set of improvement actions was generated covering most aspects of laboratory practice, such as equipment management and staff training. We also propose a useful tool supporting the risk assessment of research processes and its outputs and that we named "FMEA strip worksheet." These tools can help scientists working in non-regulated research to approach Quality Management and to perform risk evaluation of key scientific procedures and processes with the final aim to increase and better control efficiency and efficacy of their research
Fibroblastic rheumatism: a case without rheumatological symptoms.
Fibroblastic rheumatism is a rare syndrome characterized by the association of multiple cutaneous nodules with symmetric polyarthritis. We report on a patient who presented a 4-year history of pink to skin-coloured nodular lesions symmetrically localized at para-articular sites without evident rheumatological symptoms. Histopathology of a skin nodule led to the diagnosis of fibroblastic rheumatism showing a poorly circumscribed dermal proliferation of spindle and stellate fibroblast-like cells embedded in thickened collagen bundles with a marked reduction of elastic fibres. X-rays of both hands and feet showed metacarpophalangeal, metatarsalphalangeal and interphalangeal erosions, unexpected by patient history. This case of fibroblastic rheumatism appears unique in view of the absence of any clinical manifestation of polyarthritis at 7 years from appearance of skin lesions
YAP activation is an early event and a potential therapeutic target in liver cancer development
Background and Aims: Although the growth suppressor Hippo pathway has been implicated in hepatocellular carcinoma (HCC) pathogenesis, it is unknown at which stage of hepatocarcinogenesis its dysregulation occurs. We investigated in early rat and human preneoplastic lesions whether overexpression of the transcriptional co-activator Yes-associated protein (YAP) is an early event.
Methods: The experimental model used is the Resistant-Hepatocyte (R-H) rat model. Gene expression was determined by qRT-PCR or immunohistochemistry. Forward genetic experiments were performed in human HCC cells and in murine oval cells.
Results All foci of preneoplastic hepatocytes generated in rats 4 weeks after diethylnitrosamine (DENA) treatment, displayed YAP accumulation. This was associated with down-regulation of the β-TRCP ligase, known to mediate YAP degradation, and of microRNA-375, targeting YAP. YAP accumulation was paralleled by up-regulation of its target genes. Increased YAP expression was also observed in early dysplastic nodules and adenomas in humans. Animal treatment with verteporfin (VP), which disrupts the formation of the YAP–TEAD complex, significantly reduced preneoplastic foci and oval cell proliferation. In vitro experiments confirmed that VP-mediated YAP inhibition impaired cell growth in HCC and oval cells; notably, oval cell transduction with wild type or active YAP conferred tumorigenic properties in vitro and in vivo.
Conclusions: These results suggest that i) YAP overexpression is an early event in rat and human liver tumorigenesis; ii) it is critical for the clonal expansion of carcinogen-initiated hepatocytes and oval cells, and, iii) VP-induced disruption of YAP-TEAD interaction may provide an important approach for the treatment of YAP-overexpressing cancers
A protein kinase a-independent pathway controlling aquaporin 2 trafficking as a possible cause for the syndrome of inappropriate antidiuresis associated with polycystic kidney disease 1 haploinsufficiency.
Renal water reabsorption is controlled by vasopressin (AVP) which binds to V2 receptors resulting in PKA activation, phosphorylation of AQP2 at serine 256 (pS256) and translocation to the plasma membrane. Besides S256, AVP causes dephosphorylation of S261. Recent studies showed that cyclin-dependent kinases can phosphorylate S261 AQP2 peptides in vitro. In an attempt to investigate the possible role of cdks on AQP2 phosphorylation, we identified a new PKA-independent pathway regulating AQP2 trafficking. In ex-vivo kidney slices and MDCK-AQP2 cells, R-roscovitine, a specific cdks inhibitor, increased pS256 and decreased pS261. The changes in AQP2 phosphorylation were paralleled by an increase in cell surface AQP2 expression and osmotic water permeability in the absence of forskolin stimulation. Of note, R-roscovitine didn’t alter cAMP-dependent PKA activity. Because phosphorylation results from the balance between kinase and phosphatase activity, we evaluated the possible contribution of protein phosphatases PP1, PP2A and PP2B. Of these, R-roscovitine treatment specifically reduced PP2A protein expression and activity in MDCK cells. Interestingly, in PKD1+/- mice displaying a syndrome of inappropriate antidiuresis with high level of pS256 despite unchanged AVP and cAMP, we found a reduced PP2A expression and activity and reduced pS261. Similarly to what previously found in PKD1+/- mice, R-roscovitine treatment caused a significant decrease in intracellular calcium in MDCK cells.
Our data indicate that a reduced activity of PP2A, secondary to reduced intracellular Ca2+ levels, promotes AQP2 trafficking independently of the AVP-PKA axis. This pathway may be relevant for explaining pathological states characterized by inappropriate AVP secretion and positive water balance
Experimental apparatus for solar energy storage via methane production
Paper presented to the 3rd Southern African Solar Energy Conference, South Africa, 11-13 May, 2015.Renewable energy production from intermittent sources has seen a large expansion the last decade and has introduced new challenges in the energy system. Problems are related to the non-programmable electric power generated and the production peaks that especially characterize photovoltaic energy. In addition to these issues, the extensive and long-term task of reducing CO2 emissions should be considered. The utilization of CO2 as a feedstock for producing fuels not only contributes to alleviating global climate changes but also provides a new research field for energy development. An innovative process for solar energy storage via methane production seems to be a viable technology to tackle the above-mentioned issues. In this paper an experimental apparatus, formed by PV panels, a pressurized electrolyser and a Sabatier reactor is presented. The Sabatier reaction exothermically combines hydrogen and carbon dioxide to produce methane and water. The produced methane is a carbon neutral gas that fits in with the existing natural gas and allows to overcame issues related to the intermittence and non-programmability of solar power. The paper focuses on the description of the experimental apparatus and the results of a preliminary investigation. An economic evaluation was also carried out on the integration of methanation process with a traditional PV system.cf201
Characterization of a rare variant (c.2635-2A>G) of the MSH2 gene in a family with Lynch syndrome
Abstract
Introduction: Lynch syndrome is caused by germline mutations in one of the mismatch repair genes (MLH1, MSH2, MSH6, and PMS2) or in the EPCAM gene. Lynch syndrome is defined on the basis of clinical, pathological, and genetic findings. Accordingly, the identification of predisposing genes allows for accurate risk assessment and tailored screening protocols. Case Description: Here, we report a family case with three family members manifesting the Lynch syndrome phenotype, all of which harbor the rare variant c.2635-2A>G affecting the splice site consensus sequence of intron 15 of the MSH2 gene. This mutation was previously described only in one family with Lynch syndrome, in which mismatch repair protein expression in tumor tissues was not assessed. In this study, we report for the first time the molecular characterization of the MSH2 c.2635-2A>G variant through in silico prediction analysis, microsatellite instability, and mismatch repair protein expression experiments on tumor tissues of Lynch syndrome patients. The potential effect of the splice site variant was revealed by three splicing prediction bioinformatics tools, which suggested the generation of a new cryptic splicing site. The potential pathogenic role of this variant was also revealed by the presence of microsatellite instability and the absence of MSH2/MSH6 heterodimer protein expression in the tumor cells of cancer tissues of the affected family members. Conclusions: We provide compelling evidence in favor of the pathogenic role of the MSH2 variant c.2635-2A>G, which could induce an alteration of the canonical splice site and consequently an aberrant form of the protein product (MSH2)
Identification of a dna methylation episignature in the 22q11.2 deletion syndrome
The 22q11.2 deletion syndrome (22q11.2DS) is the most common genomic disorder in humans and is the result of a recurrent 1.5 to 2.5 Mb deletion, encompassing approximately 20–40 genes, respectively. The clinical presentation of the typical deletion includes: Velocardiofacial, Di George, Opitz G/BBB and Conotruncalanomaly face syndromes. Atypical deletions (proximal, distal or nested) are rare and characterized mainly by normal phenotype or mild intellectual disability and variable clinical features. The pathogenetic mechanisms underlying this disorder are not completely understood. Because the 22q11.2 region harbours genes coding for transcriptional factors and chromatin remodelers, in this study, we performed analysis of genome‐wide DNA methylation of peripheral blood from 49 patients with 22q11.2DS using the Illumina Infinium Methylation EPIC bead chip arrays. This cohort comprises 43 typical, 2 proximal and 4 distal deletions. We demonstrated the evidence of a unique and highly specific episignature in all typical and proximal 22q11.2DS. The sensitivity and specificity of this signature was further confirmed by comparing it to over 1500 patients with other neurodevelopmental disorders with known episignatures. Mapping the 22q11.2DS DNA methylation episignature provides both novel insights into the molecular pathogenesis of this disorder and an effective tool in the molecular diagnosis of 22q11.2DS
- …