Search results for "Assay"
showing 10 items of 2241 documents
Influence of the functionalisation of mesoporous silica material UVM-7 on polyphenol oxidase enzyme capture and enzymatic browning
2020
Polyphenol oxidase (PPO), also known as tyrosinase and catechol oxidase, is the enzyme responsible for enzymatic browning in foods. It causes undesirable organoleptic, nutritional and colour changes. Here, we report the preparation of five nanomaterials and a study of their ability to modulate PPO enzyme activity. The materials consist of UVM-7 supports (a mesoporous silica material) modified with diverse functional groups (i.e. amine, carboxylic acid, isocyanate, alkane and pyridine). We also studied the PPO immobilisation capability of the materials. All the materials, except the carboxylic acid functionalised one, offer high PPO loading capabilities and the immobilisation speed increases…
Acute exercise activates nuclear factor (NF)-kappaB signaling pathway in rat skeletal muscle.
2004
Two studies were performed to investigate the effects of an acute bout of physical exercise on the nuclear protein kappaB (NF-kappaB) signaling pathway in rat skeletal muscle. In Study 1, a group of rats (n=6) was run on the treadmill at 25 m/min, 5% grade, for 1 h or until exhaustion (Ex), and compared with a second group (n=6) injected with two doses of pyrrolidine dithiocarbamate (PDTC, 100 mg/kg, i.p.) 24 and 1 h prior to the acute exercise bout. Three additional groups of rats (n=6) were injected with either 8 mg/kg (i.p.) of lipopolysaccharide (LPS), 1 mmol/kg (i.p.) t-butylhydroperoxide (tBHP), or saline (C) and killed at resting condition. Ex rats showed higher levels of NF-kappaB b…
Three-dimensional invasion of human glioblastoma cells remains unchanged by X-ray and carbon ion irradiation in vitro.
2012
Purpose Cell invasion represents one of the major determinants that treatment has failed for patients suffering from glioblastoma. Contrary findings have been reported for cell migration upon exposure to ionizing radiation. Here, the migration and invasion capability of glioblastoma cells on and in collagen type I were evaluated upon irradiation with X-rays or carbon ions. Methods and Materials Migration on and invasion in collagen type I were evaluated in four established human glioblastoma cell lines exposed to either X-rays or carbon ions. Furthermore, clonogenic radiation survival, proliferation (5-bromo-2-deoxyuridine positivity), DNA double-strand breaks (γH2AX/53BP1-positive foci), a…
Plasma calprotectin levels in patients suffering from acute pancreatitis
2006
Calprotectin (Cal) concentration is elevated in acute inflammatory reactions and its increase in the plasma suggests a diagnostic potential for Cal assay. This study aimed (a) to evaluate the Cal plasma levels in patients suffering from acute pancreatitis (AP) and (b) to assess whether early assay of Cal plasma levels can be helpful in assessment of the severity of AP. Forty-six consecutive patients, median age 45 years, suffering from a first attack of AP were recruited at two medical centers. Data collected on admission included age, sex, delay between pain onset and admission, and Glasgow score. A severe outcome was defined according to the Atlanta criteria. AP was defined as edematous o…
Comparative study assessing effects of sonic hedgehog and VEGF in a human co-culture model for bone vascularisation strategies.
2011
The morphogen sonic hedgehog (Shh) seems to mediate adult repair processes in bone regeneration and vascularisation. In this study we investigated the effects of Shh on co-cultures consisting of human primary osteoblasts and outgrowth endothelial cells in terms of angiogenic activation and vessel maturation in comparison to the treatment with the commonly used proangiogenic factor, VEGF. Both, stimulation with VEGF or Shh, leads to an increase in the formation of microvessel-like structures compared to untreated controls. In contrast to VEGF, proangiogenic effects by Shh could already be observed after 24 h of treatment. Nevertheless, after 14 days the angiogenic activity of OEC was compara…
Tartrate-Resistant Acid Phosphatase 5b: A Novel Serum Marker of Bone Resorption
2000
Human serum contains two forms of tartrate-resistant acid phosphatase (TRAP), 5a and 5b. Of these, 5a contains sialic acid and 5b does not. We show here that antigenic properties and pH optimum of TRAP purified from human osteoclasts are identical to those of serum TRAP 5b and completely different from those of serum TRAP 5a, suggesting that 5b would be derived from osteoclasts and 5a from some other source. We developed a novel immunoassay specific for 5b using a monoclonal antibody O1A as capture antibody. O1A did not bind acid phosphatase derived from platelets and erythrocytes. Western analysis showed that O1A was specific for TRAP in both human bone and serum. We measured bound TRAP ac…
Organotypic rat cerebellar slice culture as a model to analyze the molecular pharmacology of GABAA receptors
2002
The preservation of the neuronal circuitry in rat cerebellar slice cultures provides an advantage in monitoring the development and characterizing the pharmacology of GABA(A) receptor subtypes. Sprague-Dawley rats, 8-11 days of age, were decapitated, their cerebella were cut into 400-microm slices and transferred into culture dishes. Cell viability and organotypic cerebellar organization of the culture remained well preserved up to 3 weeks. Autoradiographic procedures were introduced in these advanced culture technique and employed [(3)H]Ro 15-4513 in the absence and presence of 10 microM diazepam to visualize all benzodiazepine (BZD) and diazepam-insensitive (DIS) binding sites, respective…
Multiple changes induced by fibroblasts on breast cancer cells.
2010
It is now widely recognised that the cross-talk between cancer and stromal cells may play a crucial role in cancer progression. However little is known about the complex underlying molecular mechanisms that occur within the tumor microenvironment. Fibroblasts are the major stromal cells with multiple roles, especially towards both the extracellular matrix and the neighbouring cell population, including neoplastic cells. Consequently, proteomic analyses would provide a wider resource for a better understanding of the potential modulating effects exerted by fibroblasts on cancer cells. In this report we describe the effects of fibroblast stimulation on the breast cancer cell line (8701-BC) pr…
Longitudinal Analysis of Serum Autoantibody-Reactivities in Patients with Primary Open Angle Glaucoma and Optic Disc Hemorrhage.
2015
Background The aim of our current investigation was to analyze the autoantibody-reactivities of primary open angle glaucoma patients with optic disc hemorrhage as possibly correlated to disease progression by means of a protein microarray approach. Methods Sera of patients with primary open angle glaucoma and optic disc hemorrhage (n = 16) were collected directly after study inclusion (0 weeks) and after 2 weeks, 4 weeks and 12 weeks. As a control group patients with primary open angle glaucoma (n = 18) were used (0 weeks and 12 weeks). Microarrays were incubated and occurring antibody-antigen-reactions were visualized with fluorescence labeled anti-human-IgG secondary antibodies. To detect…
Phenotypic Heterogeneity of the Insect Pathogen Photorhabdus luminescens: Insights into the Fate of Secondary Cells
2019
Photorhabdus luminescens is a Gram-negative bacterium that lives in symbiosis with soil nematodes and is simultaneously highly pathogenic toward insects. The bacteria exist in two phenotypically different forms, designated primary (1°) and secondary (2°) cells. Yet unknown environmental stimuli as well as global stress conditions induce phenotypic switching of up to 50% of 1° cells to 2° cells. An important difference between the two phenotypic forms is that 2° cells are unable to live in symbiosis with nematodes and are therefore believed to remain in the soil after a successful infection cycle. In this work, we performed a transcriptomic analysis to highlight and better understand the rol…