Search results for "VITRO"
showing 10 items of 2786 documents
RNA marker modifications reveal the necessity for rigorous preparation protocols to avoid artifacts in epitranscriptomic analysis
2021
Abstract The accurate definition of an epitranscriptome is endangered by artefacts resulting from RNA degradation after cell death, a ubiquitous yet little investigated process. By tracing RNA marker modifications through tissue preparation protocols, we identified a major blind spot from daily lab routine, that has massive impact on modification analysis in small RNAs. In particular, m6,6A and Am as co-varying rRNA marker modifications, appeared in small RNA fractions following rRNA degradation in vitro and in cellulo. Analysing mouse tissue at different time points post mortem, we tracked the progress of intracellular RNA degradation after cell death, and found it reflected in RNA modific…
Targeted delivery of siRNAs against hepatocellular carcinoma-related genes by a galactosylated polyaspartamide copolymer
2021
Given the lack of effective treatments for Hepatocellular carcinoma (HCC), the development of novel therapeutic approaches is very urgent. Here, siRNAs were delivered to HCC cells by a synthetic polymer containing α,β-poly-(N-2-hydroxyethyl)-D,L-aspartamide-(PHEA) derivatized with diethylene triamine (DETA) and bearing in the side chain galactose (GAL) linked via a polyethylene glycol (PEG) to obtain (PHEA-DETA-PEG-GAL, PDPG). The GAL residue allows the targeting to the asialo-glycoprotein receptor (ASGPR), overexpressed in HCC cells compared to normal hepatocytes. Uptake studies performed using a model siRNA or a siRNA targeted against the enhanced green fluorescence protein, demonstrated …
In vitro contamination of hair by marijuana smoke.
2004
Abstract Background: The deposition of cannabinoids on/into hair from environmental smoke can be considered as a potential source of drug findings in hair. We studied external uptake of cannabinoids from marijuana smoke, investigating possible influencing factors on drug uptake and the efficiency of decontamination procedures. Methods: Strands of a natural hair sample were moistened with water, greased with sebum or sebum/sweat, or bleached or permed. Treated and untreated samples were exposed to marijuana smoke for 60 min. Aliquots of each hair strand were either kept unwashed or were washed with methanol, dichloromethane, or 5 g/L dodecyl sulfate in water. Cannabinoid concentrations in un…
Bonding efficacy of an acetone/based etch-and-rinse adhesive after dentin deproteinization
2012
Objectives: to evaluate the effect of sodium hypochlorite (NaOCl) treatment on dentin bonding by means of shear bond strength (SBS) measurements when using Prime&Bond NT (PB NT) adhesive. Ultrastructure of the interfaces was examined by scanning electron microscopy (SEM). Study design: Extracted human third molars were sectioned and ground to expose flat surfaces of superficial or deep dentin. Specimens were randomly assigned to two equal groups, and bonded as follows: (1) according to the manufacturers’ directions, after 35% H3PO4 etching, (2) 5% NaOCl treated for 2 minutes, after 35% H3PO4 etching. Each sample was embedded in a Watanabe shear test assembly for a single plane lap shear. Af…
Nanostructural changes in dentine caused by endodontic irrigants
2013
Objective: To study nanostructural dentinal changes produced by endodontic irrigants. Study Design: Experimental study. Nanoindentations were performed on peritubular (PD) and intertubular dentine (ID) with an atomic force microscopy. Stiffness and adhesion force were determined before and after application of 5.25% sodium hypochlorite (NaOCl) and 17% ethylenediaminetetraacetic acid (EDTA). Normalized differences before and after treatment for stiffness and adhesion forces were calculated. A paired T-test was used to compare stiffnes and adhesion force before and after irrigants application. Results: After treatment with EDTA there was a 29.80% reduction in stiffness in ID and a 63.53% redu…
Effect of postbleaching application of an antioxidant on enamel bond strength of three different adhesives
2010
Objectives: The aim of this study was to compare the shear bond strength (sbs) of three different adhesives on bleached enamel immmmediately after bleaching, bleached/delayed for 1 week, and bleached/applied antioxidizing agent. Study Design: The enamel surfaces of 144 freshly extracted incisors without any caries and restorations were flattened and divided into 12 groups. The following adhesives were investigated: Optibond FL (OFL) (three-step etch&rinse), Optibond Solo Plus (OSP) (two-step etch&rinse), Optibond All-in-One (OA) (one-step self-etch), (Kerr, Orange, USASA). Unbleached enamel groups were prepared as negative controls. The remainder surfaces were bleached with 20% Opalescent P…
Mechanisms of endothelial cell swelling from lactacidosis studied in vitro
2000
One of the early sequelae of ischemia is an increase of circulating lactic acid that occurs in response to anaerobic metabolism. The purpose of the present study was to investigate whether lactic acidosis can induce endothelial swelling in vitro under closely controlled extracellular conditions. Cell volume of suspended cultured bovine aortic endothelial cells was measured by use of an advanced Coulter technique employing the “pulse area analysis” signal-processing technique (CASY1). The isosmotic reduction of pH from 7.4 to 6.8 had no effect on cell volume. Lowering of pH to 6.6, 6.4, or 6.0, however, led to significant, pH-dependent increases of cell volume. Swelling was more pronounced …
Effect of the dissolution time into an acid hydrolytic solvent to tailor electrospun nanofibrous polycaprolactone scaffolds
2017
[EN] The hydrolysis of the polycaprolactone (PCL) as a function of the dissolution time in a formic/acetic acid mixture was considered as a method for tailoring the morphology of nanofibrous PCL scaffolds. Hence the aim of this research was to establish a correlation between the dissolution time of the polymer in the acid solvent with the physicochemical properties of the electrospun nanofibrous scaffolds and their further service life behaviour. The physico-chemical properties of the scaffolds were assessed in terms of fibre morphology molar mass and thermal behaviour. A reduction of the molar mass and the lamellar thickness as well as an increase of the crystallinity degree were observed …
Aberrant methylation patterns at the two-cell stage as an indicator of early developmental failure
2002
The fertilized mouse egg actively demethylates the paternal genome within a few hours after fertilization, whereas the maternal genome is only passively demethylated by a replication-dependent mechanism after the two-cell stage. This evolutionarily conserved assymetry in the early diploid mammalian embryo may have a role in methylation reprogramming of the two very different sets of sperm and egg chromatin for somatic development and formation of totipotent cells. Immunofluorescence staining with an antibody against 5-methylcytosine (MeC) showed that the incidence of abnormal methylation patterns differs between mouse two-cell embryos from superovulated females, nonsuperovulated matings, an…
Molecular mechanism of T-cell protein tyrosine phosphatase (TCPTP) activation by mitoxantrone.
2013
T-cell protein tyrosine phosphatase (TCPTP) is a ubiquitously expressed non-receptor protein tyrosine phosphatase. It is involved in the negative regulation of many cellular signaling pathways. Thus, activation of TCPTP could have important therapeutic applications in diseases such as cancer and inflammation. We have previously shown that the α-cytoplasmic tail of integrin α1β1 directly binds and activates TCPTP. In addition, we have identified in a large-scale high-throughput screen six small molecules that activate TCPTP. These small molecule activators include mitoxantrone and spermidine. In this study, we have investigated the molecular mechanism behind agonist-induced TCPTP activation.…