Search results for "Biological Factor"
showing 10 items of 74 documents
Evolution of Carotenoid Content, Antioxidant Activity and Volatiles Compounds in Dried Mango Fruits (Mangifera Indica L.)
2020
The aim of this research was to study the evolution of carotenoid compounds, antioxidant &beta
All-trans retinoic acid for treatment of chronic hepatitis C
2008
Background/Aims: In vitro studies in the subgenomic hepatitis C virus (HCV) replicon system have identified all-trans retinoic acid (ATRA) as a potential therapeutic against hepatitis C. Thus, the antiviral potential of this drug should be assessed in vivo. Methods: Twenty highly treatment experienced serotype 1 patients with non-response to conventional or pegylated interferon-α (Peg-/IFN-α) and ribavirin were randomly assigned to 12 weeks of monotherapy with ATRA (group A) or a combination of ATRA and PegIFN-α2a (group B). HCV RNA was assessed by bDNA assay and if negative by highly sensitive polymerase chain reaction. Results: During treatment, five of 10 patients in group A had a drop o…
MUC1-CT mediates corticosteroid responses in COPD
2016
Background: Corticosteroid resistance is an acquired condition in chronic obstructive pulmonary disease (COPD) patients and a challenge to develop new anti-inflammatory therapies. In previous reports we showed that cytoplasmic tail of the membrain tethered mucin 1 (MUC1-CT) interacts with glucocorticoid receptor (GR) mediating corticosteroid anti-inflammatory efficacy. Objectives: To analyze the role of MUC1-CT as a key marker of corticosteroid efficacy in COPD Methods: The expression of MUC1-CT and the anti-inflammatory role of dexamethasone were evaluated in neutrophils and bronchial epithelial cells from healthy and COPD patients. Anti-inflammatory effects of dexamethasone and glucocorti…
Prevention and reversal of superantigen-induced anergy by contact allergen exposure
1995
The superantigen Staphylococcal enterotoxin B (SEB) and the contact allergen 2,4-dinitrofluorbenzene (DNFB) both react with V beta 8+ T-cells delivering distinct signals. Pre-treatment with DNFB painted onto the same skin site where SEB was to be injected, prevented the induction of anergy in V beta + T-cells that was otherwise induced after SEB had been injected intradermally over a period of 2 weeks. Application of the irritant sodium dodecyl sulfate (SDS) instead of DNFB did not exert this effect. Application of DNFB at a site distant from the site where SEB was injected resulted in a much weaker inhibitory influence on the induction of anergy by SEB. Established anergy of V beta 8+ T-ce…
Obesity, type 2 diabetes and risk of digestive cancer.
2010
The frequency of obesity has been increasing worldwide for 20 years. Many epidemiological studies support a correlation between obesity and increased risk of cancer, particularly digestive cancers in both genders, and gynaecological cancer in women. Currently, about 5% of cancers could be directly related to overweight. Carcinogenesis mechanisms induced by obesity involve insulin resistance, adipokine and angiogenic factor secretions, and inflammation. Experimental and clinical evidence suggest that insulin resistance plays a major role in carcinogenesis. Insulin and non-protein banded IGF-1, whose levels are increased in type 2 diabetes, stimulate cellular growth and inhibit apoptosis. Abn…
An experimental test of the dose-dependent effect of carotenoids and immune activation on sexual signals and antioxidant activity.
2004
Carotenoid‐based sexual traits are thought to be reliable indicators of male quality because they might be scarce and therefore might indicate the ability of males to gather high‐quality food and because they are involved in important physiological functions (as immune enhancers and antioxidants). We performed an experiment where male and female zebra finches (Taeniopygia guttata) were provided with increasing carotenoid doses in the drinking water during 4 weeks (bill color of this species is a carotenoid‐based sexual signal). Simultaneously, birds were split into two groups: one receiving weekly injections of Escherichia coli lipopolysaccharide in order to activate the immune system, the …
Biochemical and Immunological implications of Lutein and Zeaxanthin
2021
Throughout history, nature has been acknowledged for being a primordial source of various bioactive molecules in which human macular carotenoids are gaining significant attention. Among 750 natural carotenoids, lutein, zeaxanthin and their oxidative metabolites are selectively accumulated in the macular region of living beings. Due to their vast applications in food, feed, pharmaceutical and nutraceuticals industries, the global market of lutein and zeaxanthin is continuously expanding but chemical synthesis, extraction and purification of these compounds from their natural repertoire e.g., plants, is somewhat costly and technically challenging. In this regard microbial as well as microalga…
Modulation of Contact Sensitivity Responses by Bacterial Superantigen
1995
Superantigens are potent modulators of the immune system, especially T cells. Therefore, we determined the influence of superantigens on the T-cell-mediated immune response, contact sensitivity. We chose the combination of staphylococcal enterotoxin B (SEB) as superantigen and 2,4-dinitrofluorbenzene (DNFB) as the contact sensitizer, because in BALB/c mice SEB reacts almost exclusively with V beta 8+ T cells, and these cells are capable of transferring contact sensitivity to DNFB from sensitized donors to naive syngeneic recipients. Pretreatment with a single intradermal injection of 50 ng SEB 24 h before DNFB exposure at the same site on the lower abdomen enhanced the induction of contact …
Dental stem cell signaling pathway activation in response to hydraulic calcium silicate-based endodontic cements: A systematic review of in vitro stu…
2020
Abstract Objective To present a qualitative synthesis of in vitro studies which analyzed human dental stem cell (DSC) molecular signaling pathway activation in response to hydraulic calcium silicate-based cements (HCSCs). Methods A systematic electronic search was performed in Medline, Scopus, Embase, Web of Science and SciELO databases on January 20 and last updated on March 20, 2020. In vitro studies assessing the implication of signaling pathways in activity related marker (gene/protein) expression and mineralization induced by HCSCs in contact with human DSCs were included. Results The search identified 277 preliminary results. After discarding duplicates, and screening of titles, abstr…
Granulocyte-macrophage colony-stimulating factor induces cytokine secretion by human polymorphonuclear leukocytes.
1989
Granulocyte-macrophage colony-stimulating factor (GM-CSF) is known as an inducer of proliferation and functional activation of myeloid cells. This study was carried out to characterize the effects of GM-CSF on polymorphonuclear leukocytes (PMN) more extensively. Using Northern blot analysis, we show that PMN are able to accumulate mRNAs for different cytokines, including tumor necrosis factor-alpha (TNF-alpha); G-CSF, and M-CSF, all of which are involved in inflammation and hematopoiesis. Biological assays and immunoassays demonstrate that PMN translate these mRNAs, except TNF-alpha, into secretory proteins. However, the expression of these cytokines is dependent on stimulation by exogenous…