The vasculature constantly experiences distension/pressure exerted by blood flow and responds to maintain homeostasis. We hypothesized that activation of the stretch sensitive, non-selective cation channel Piezo1 would directly increase vascular contraction in a way that might be modified by perivascular adipose tissue (PVAT). The presence and function of Piezo1 was investigated by RT-PCR, immunohistochemistry, and isolated tissue bath contractility.
View Article and Find Full Text PDFAim: To compare body composition (BC) of premature infants at parenteral nutrition (PN) suspension and at term equivalent age (TEA).
Methods: Body weight, fat mass (FM), fat free mass (FFM) and FM as % of body weight were measured in infants born at <32 gestational weeks by air-displacement plethysmography at PN suspension and at TEA in a tertiary level hospital. Z-scores were calculated for BC and anthropometric measurements.
In this short note we describe the conversion of the widely used fluorescence quenching azo-dyes DABCYL and HABA to fluorophores. The dyes were conjugated to the proteins RNase and human serum albumin (HSA) and subsequently reduced using sodium dithionite (NaSO), thus forming amine-containing fluorophores. Since this chemical reaction can be applied to any azo-containing quencher compound, a great variety of substances can be readily obtained synthetically.
View Article and Find Full Text PDFJ Chromatogr B Analyt Technol Biomed Life Sci
September 2018
Since the importance of the high affinity between avidin and biotin, K = 3 × 10 M, gained universal recognition, numerous chemical, biological and medical avidin-biotin based applications have been developed. However, in some cases the high affinity may be a disadvantage, as this interaction is irreversible under physiological conditions. The dye, 4'-hydroxyazobenzene-2-carboxylic acid (HABA), binds avidin, at the biotin binding site, as determined by X-ray, at a much lower affinity constant, K = 6 × 10 M.
View Article and Find Full Text PDFHuman serum contains natural antibodies against avidin. Affinity purified natural anti-avidin human IgG exhibits affinity constants comparable to those of antibodies produced by active immunization of rabbits. Using a random hexapeptide library displayed on the filamentous M13 phage, and rabbit anti-avidin purified antibodies as a selector, we searched for epitopes shared by both selector and natural human anti-avidin IgG.
View Article and Find Full Text PDFA colorimetric method for determining cyanuric chloride (CC) and for monitoring its polysaccharide gel activation, before and after ligand binding, was developed. The method is based on the reaction of CC or its activated gel with pyridine and barbituric acid or dimethylbarbituric acid. The product formed yields a purple red color with λ max at 595 nm, and an E value of approximately 300,000 after 1 h at room temperature.
View Article and Find Full Text PDFOur objective was to develop a method mimicking the natural process of coherence in marine mollusks, by direct chemical conversion of protein tyrosine residues to DOPA-o-quinones, which consequently generates polymerization and cross-linking. Fremy's salt, (ON(SO3K)2, was used to convert tyrosine residues in peptides and proteins to reactive o-quinones. The conversion of tyrosines to DOPA-o-quinones, and their ability to polymerize or cross-link, was tested on tyramine, peptides, and proteins.
View Article and Find Full Text PDFIn this work, the mild disintegration of the microalgae Chlorella vulgaris for the release of intracellular products has been studied. By means of bead milling the microalgae suspensions were successfully disintegrated at different biomass concentrations (25-145 gDW kg(-1)) over a range of agitator speeds (6-12 m s(-1)). In all cases over 97% of cell disintegration was achieved resulting in a release of water soluble proteins.
View Article and Find Full Text PDFIn this note, we describe a method devised to detect, by means of mass spectrometry (MS), tryptophan-containing peptides and proteins using pyridine-borane. This reagent selectively reduces tryptophan residues, converting them to 2,3-dihydro-tryptophan, thereby enabling quantitation of tryptophans.
View Article and Find Full Text PDFIn this work enzyme-assisted extraction (EAE) and pressurized liquid extraction (PLE) are applied for extraction of natural compounds from lemon balm (Melissa officinalis). Cellulase, endo-β-1,4 xylanase and pectinase were studied in order to degrade cell wall of lemon balm leaves and to release phenolic compounds. On the other hand, in order to compare the performance obtained with EAE, PLE using water and ethanol was employed maintaining 150°C as extraction temperature.
View Article and Find Full Text PDFIn this study, two-dimensional gel electrophoresis (2-DE) and matrix-assisted laser desorption/ionisation-time of flight mass spectrometry (MALDI-TOF-MS) technology was used to examine differentially expressed proteins in oral squamous cell carcinoma (OSCC) tissues from Norway (n=15) and the UK (n=45). Twenty-nine proteins were found to be significantly overexpressed in the OSCCs examined compared to the normal controls. Identified proteins included, family of annexin proteins that play important roles in signal transduction pathways and regulation of cellular growth, keratin-1, heat-shock proteins (HSP), squamous cell carcinoma antigen (SCC-Ag), cytoskeleton proteins, and proteins involved in mitochondrial and intracellular signalling pathways.
View Article and Find Full Text PDFS-allylthio-6-mercaptopurine and its ribose derivative were tested for anti-leukemic activity, using a human- mouse B-CLL model. The novel prodrugs contain two components, a purine analog, which interferes with DNA synthesis, and an S-allylthio, readily engaging in thiol-disulfide exchange reactions. The latter component targets the redox homeostasis which is more sensitive in leukemic cells, than in normal B-cells.
View Article and Find Full Text PDFIn this contribution, pressurized liquid extraction (PLE) has been employed to isolate bioactive compounds from three native Romanian plants, oregano (Origanum vulgare), tarragon (Artemisia dracunculus) and wild thyme (Thymus serpyllum). Different PLE conditions have been tested including extraction with water, ethanol and their mixtures in a wide range of extraction temperatures (50-200°C), and the antioxidant capacity of the extracts was measured using different assays (DPPH radical scavenging, TEAC assay and Folin-Ciocalteau assay to measure total phenols). Moreover, a complete chemical characterization by using LC-MS/MS was carried out to be able to correlate the bioactivity with the particular chemical composition of each extract and plant.
View Article and Find Full Text PDFAllylsulfides from garlic are chemopreventive agents. Entering cells they are expected to initially interact with glutathione. Accordingly, reaction mechanisms of the product, S-allylthio-glutathione, with model proteins and thiols were analyzed in cell free systems.
View Article and Find Full Text PDFAlliinase, an enzyme found in garlic, catalyzes the synthesis of the well-known chemically and therapeutically active compound allicin (diallyl thiosulfinate). The enzyme is a homodimeric glycoprotein that belongs to the fold-type I family of pyridoxal-5'-phosphate-dependent enzymes. There are 10 cysteine residues per alliinase monomer, eight of which form four disulfide bridges and two are free thiols.
View Article and Find Full Text PDFBackground: Allicin in garlic is the primary active compound known to rapidly interact with free thiols.
Aims Of The Study: To examine the effect of allicin on gene expression and glutathione cellular level in vascular endothelial cells.
Methods: Cultured endothelial cells were exposed to allicin; mRNA was prepared and subjected to Micro-array and Real-Time PCR.
Biologically active S-allylthio derivatives of 6-mercaptopurine (6-MP) and 6-mercaptopurine riboside (6-MPR) were synthesized. The products, S-allylthio-6-mercaptopurine (SA-6MP) and S-allylthio-6-mercaptopurine riboside (SA-6MPR) were characterized. The antiproliferative activity of the new prodrugs was tested on human leukemia and monolayer cell lines, and compared to that of their parent reactants.
View Article and Find Full Text PDFIn this article, the effects of allicin, a biological active compound of garlic, on HL60 and U937 cell lines were examined. Allicin induced growth inhibition and elicited apoptotic events such as blebbing, mitochondrial membrane depolarization, cytochrome c release into the cytosol, activation of caspase 9 and caspase 3 and DNA fragmentation. Pretreatment of HL60 cells with cyclosporine A, an inhibitor of the mitochondrial permeability transition pore (mPTP), inhibited allicin-treated cell death.
View Article and Find Full Text PDFObjective: This study aimed to assess 1) the relationship between risk-taking behaviors and exposure to terrorism, 2) the relationship between posttraumatic symptoms and risk-taking behaviors, and 3) gender differences in the type and frequency of risk-taking behaviors and their differential associations with posttraumatic symptoms.
Method: The participants were 409 Israeli adolescents 15 to 18 years of age. Exposure to terrorism was assessed with a questionnaire developed specifically for the Israeli security situation.
Objective: Garlic (Allium sativum) has been suggested to affect several cardiovascular risk factors. Its antiatherosclerotic properties are mainly attributed to allicin that is produced upon crushing of the garlic clove. Most previous studies used various garlic preparations in which allicin levels were not well defined.
View Article and Find Full Text PDFPure allicin, prepared biosynthetically by reacting synthetic alliin with an immobilized alliinase enzyme, is known to possess cardioprotective effects. However, in its pure form, allicin is pharmacologically unstable. S-allylmercaptocaptopril (CPSSA) is a new stable synthetic compound produced by chemical reaction between allicin and the angiotensin converting enzyme inhibitor captopril.
View Article and Find Full Text PDFCancer Genomics Proteomics
November 2005
Antibody microarrays, two-dimensional electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (2-DE/MALDI-TOF-MS) were used to examine protein changes in 56 oral cancers (OCs)/normal controls (NCs) from Sudanese (41 OCs vs. 31 NCs) and Sri Lankan (15 OCs vs. 15 NCs) patients.
View Article and Find Full Text PDFAllicin, a highly active component from freshly crushed garlic, is produced upon the reaction of the small molecular weight molecule alliin, with the enzyme alliinase (EC 4.4.1.
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