Search results for "Assay"
showing 10 items of 2241 documents
Encapsulation of Alcohol Dehydrogenase in Mannitol by Spray Drying
2014
The retention of the enzyme activity of alcohol dehydrogenase (ADH) has been studied in various drying processes such as spray drying. The aim of this study is to encapsulate ADH in mannitol, either with or without additive in order to limit the thermal denaturation of the enzyme during the drying process. The retention of ADH activity was investigated at different drying temperatures. When mannitol was used, the encapsulated ADH was found inactive in all the dried powders. This is presumably due to the quick crystallization of mannitol during spray drying that resulted in the impairment of enzyme protection ability in comparison to its amorphous form. Maltodextin (dextrose equivalent = 11)…
A bioluminescence technique for quantitative and structure-associated imaging of pyruvate
2006
A novel bioluminescence assay has been developed for measuring pyruvate within sections of snap-frozen tissue in a quantitative manner as well as with a spatial resolution on a microscopical level. The assay was verified via HPLC and two independent photometric tests. The novel assay makes it possible to determine pyruvate concentrations in cryosections in the range of 0-5.0 micromol/g tissue (dry weight). Based on the analysis of samples of given pyruvate concentrations, the assay exhibits a recovery with a deviationor =15%. The minimal detectable amount was 0.02 pmol based on a 20 microm thick tissue section with an area of 1 cm(2). Combination of the already established imaging biolumine…
Detection of enteric adenoviruses 40 and 41 in stool specimens by monoclonal antibody-based enzyme immunoassays
1996
To examine the role of enteric adenoviruses (Ad40 and Ad41) in children with acute gastroenteritis, we evaluated 273 children with diarrhoea and 137 without enteric symptoms in Palermo, Italy, during an 8-month period. Stools were tested by two home-made monoclonal-based ELISAs to detected genus-specific adenovirus antigen and to type Ad40 and Ad41. Twenty-five samples (6.1%) were found to contain adenovirus, 18 of which were grown in Graham 293 and in HEp-2 cells. Ad40 and Ad41 were detected in 2.6% of children with diarrhoea and in none in the control group, while non-enteric adenoviruses were obtained from both patients (3.2%) and controls (6.5%). Samples containing Ad40 and Ad41 were po…
Diclofenac sodium and cyclosporin A inhibit human lens epithelial cell proliferation in culture.
1997
• Purpose: To investigate the effect of diclofenac sodium salt and cyclosporin A (CsA) on human lens epithelial cell (HLEC) growth in culture. • Methods: Cultures of HLEC were obtained from anterior capsules from extracapsular cataract surgery. Third-passage cells were seeded in 96-well plates in 0.1 ml culture medium. Cytotoxicity was estimated by the tetrazolium test in confluent monolayers after 24 h exposure to a wide range of concentrations of diclofenac and CsA. The effect of subcytotoxic concentrations of diclofenac and CsA on HLEC proliferation in subconfluent cultures was evaluated after 24 and 72 h of exposure. To investigate the relationship between PGEZ synthesis and the inhibit…
Chitin synthetase activity in Candida albicans: subcellular distribution in yeast cells and protoplasts
1991
Chitin synthetase activity was detected in a partly zymogenic form in cell-free homogenates obtained from C. albicans yeast cells and protoplasts of the same type of cells. By isopycnic centrifugation on sucrose gradients of the cell-free homogenates two fractions with chitin synthetase activity were obtained: one was associated with the plasma membrane (labelled with [ 3 H]concanavalin A (con A) and buoyant density 1·195 g ml −1 ) in a partly active state, and the second was in the cytoplasm, where the enzyme was in a particulate fully zymogenic form, lacking affinity to con A. The buoyant density of the enzyme found in this location depended on the method of cell breakage. Lysis of partly…
Metal ions modify DNA-protecting and mutagen-scavenging capacities of the AV-153 1,4-dihydropyridine.
2019
Abstract 1,4-Dihydropyridines (1,4-DHP) possess important biochemical and pharmacological properties, including antioxidant and antimutagenic activities. AV-153-Na, an antimutagenic and DNA-repair enhancing compound was shown to interact with DNA by intercalation. Here we studied DNA binding of several AV-153 salts to evaluate the impact of AV-153 modifications on its DNA binding capacity, the ability to scavenge the peroxynitrite, to protect HeLa and B-cells cells against DNA damage. Affinity of the AV-153 salts to DNA measured by a fluorescence assay was dependent on the metal ion forming a salt in position 4 of the 1,4-DHP, and it decreased as follows: Mg > Na > Ca > Li > Rb > K. AV-153-…
Effects of escitalopram on the regulation of brain-derived neurotrophic factor and nerve growth factor protein levels in a rat model of chronic stres…
2009
Escitalopram (ES-CIT) is a widely used, highly specific antidepressant. Until now there has been very little evidence on how this drug under pathological conditions affects an important feature within the pathophysiology of stress-related disorders such as depression: the endogenous neurotrophins. By using a well-characterized rat model in which chronic stress induces depressive-like behavior, the levels of neurotrophins brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) were determined in representative brain regions and serum using a highly sensitive improved fluorometric two-site ELISA system. There was a significant increase of BDNF in the left and right cortices aft…
Studies on a new potential dopaminergic agent: in vitro BBB permeability, in vivo behavioural effects and molecular docking evaluation.
2015
2-Amino-N-[2-(3,4-dihydroxy-phenyl)-ethyl]-3-phenyl-propionamide (DA-PHEN) has been previously synthesized to obtain a potential prodrug capable of release dopamine (DA) into CNS. However, DA-PHEN could act per se as a dopaminergic drug. In this study, the permeability transport (Pe), obtained by parallel artificial permeability assay (PAMPA), indicated a low passive transcellular transport (Pe = 0.32 ± 0.01 × 10(-6 )cm/s). Using the Caco-2 cell system, the Papp AP-BL in absorptive direction (3.36 ± 0.02 × 10(-5 )cm/s) was significantly higher than the Papp BL-AP in secretive direction (1.75 ± 0.07 × 10(-5 )cm/s), suggesting a polarized transport. The efflux ratio (Papp AP-BL/Papp BL-AP = 0…
Chronic cocaine exposure impairs progenitor proliferation but spares survival and maturation of neural precursors in adult rat dentate gyrus
2006
Recent observations indicate that drugs of abuse, including alcohol and opiates, impair adult neurogenesis in the hippocampus. We have studied in rats the impact of cocaine treatment (20 mg/kg, daily, i.p.) on cell proliferation, survival and maturation following short-term (8-day) and long-term (24-day) exposure. Using 5'-bromo-2-deoxyuridine (BrdU) and Ki-67 as mitotic markers at the end of the drug treatments, we found that both short- and long-term cocaine exposures significantly reduced cell proliferation in the dentate gyrus (DG) of the hippocampus. By labelling mitotic cells with BrdU pulses before or during the early stages of the drug treatment, we determined that long-term cocaine…
Synthesis of N-acyl Derivatives of Aminocombretastatin A-4 and Study of their Interaction with Tubulin and Downregulation of c-Myc.
2021
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