Search results for "HYPOXIA"
showing 10 items of 508 documents
Pathophysiological approaches to identifying tumor hypoxia in patients
1991
The present report summarizes observations of the authors on tumor oxygenation and on techniques for characterizing tumor hypoxia in patients. Cryospectrophotometric measurements of HbO2 saturations in tumor microvessels allow for estimates of the proportion of well oxygenated tissue regions. Labeling of tissue areas at oxygen (O2) tensions (pO2) less than 10 mm Hg with misonidazole may be used for a general characterization of the oxygenation status in patient tumors rather than for the determination of the radiobiologically hypoxic cell fraction. Quantitative bioluminescence and single photon imaging make it possible to determine ATP concentrations in absolute terms with a spatial resolut…
Synthesis, physicochemical characterization, cytotoxicity, antimicrobial, anti-inflammatory and psychotropic activity of new N-[1,3-(benzo)thiazol-2-…
2012
Abstract A series of new N-[(benzo)thiazol-2-yl]-2/3-[3,4-dihydroisoquinolin-2(1H)-yl]ethan/propanamide derivatives was synthesized and characterized by 1H, 13C NMR and IR spectroscopy and mass-spectrometry. A single crystal X-ray study of N-(1,3-benzothiazol-2-yl)-2-[3,4-dihydroisoquinolin-2(1H)-yl]ethanamide is reported to determine its conformational feature. The investigated compounds were found to be active in psychotropic in vivo, anti-inflammatory in vivo and cytotoxicity in vitro screening. They possess marked sedative action, reveal high anti-inflammatory activity, have selective cytotoxic effects and NO-induction ability concerning tumour cell lines. Some of the compounds synthesi…
Inhibition of tumor lactate oxidation: consequences for the tumor microenvironment.
2011
Abstract Background and purpose Tumor cells are recognized as being highly glycolytic. However, recently it was suggested that lactate produced in hypoxic tumor areas may be taken up by the monocarboxylate transporter MCT1 and oxidized in well-oxygenated tumor parts. Furthermore, it was shown that inhibition of lactate oxidation using the MCT1 inhibitor α-cyano-hydroxycinnamate (CHC) can radio-sensitize tumors possibly by forcing a switch from lactate oxidization to glycolysis in oxygenated cells, which in turn improves tumor oxygenation and indirectly kills radio-resistant hypoxic tumor cells from glucose starvation. Material and methods To provide direct evidence for the existence of a ta…
Redox signaling in acute pancreatitis
2015
Acute pancreatitis is an inflammatory process of the pancreatic gland that eventually may lead to a severe systemic inflammatory response. A key event in pancreatic damage is the intracellular activation of NF-κB and zymogens, involving also calcium, cathepsins, pH disorders, autophagy, and cell death, particularly necrosis. This review focuses on the new role of redox signaling in acute pancreatitis. Oxidative stress and redox status are involved in the onset of acute pancreatitis and also in the development of the systemic inflammatory response, being glutathione depletion, xanthine oxidase activation, and thiol oxidation in proteins critical features of the disease in the pancreas. On th…
Hypoxia induces proinflammatory cytokines production in alpha-1 antitrypsin deficiency patients
2021
Introduction: Alpha-1 antitrypsin deficiency (AATD) is a rare respiratory condition characterized by abnormal inflammation, where neutrophils play a key role. Excessive neutrophil activation leads to an increase in the oxygen (O2) intake, causing local hypoxia and increased tissue-injury capacity. Tissue hypoxia is part of the inflammatory process so neutrophils can function effectively under these conditions. However, the mechanisms by which neutrophils mediate tissue damage under hypoxia remain unclear. The study aimed to determine whether hypoxia modifies the cytokine profile in AATD patients. Methods: Neutrophils from 22 AATD patients (6 MZ; 9 SZ; 7 ZZ) and 7 controls (MM) were exposed …
Identification of a novel recurrent 1q42.2-1qter deletion in high risk MYCN single copy 11q deleted neuroblastomas
2012
Neuroblastoma is an aggressive embryonal tumor that accounts for similar to 15% of childhood cancer deaths. Hitherto, despite the availability of comprehensive genomic data on DNA copy number changes in neuroblastoma, relatively little is known about the genes driving neuroblastoma tumorigenesis. In this study, high resolution array comparative genome hybridization (CGH) was performed on 188 primary neuroblastoma tumors and 33 neuroblastoma cell lines to search for previously undetected recurrent DNA copy number gains and losses. A new recurrent distal chromosome 1q deletion (del(1)(q42.2qter)) was detected in seven cases. Further analysis of available array CGH datasets revealed 13 additio…
Reduction of olfactory sensitivity during normobaric hypoxia.
2018
Abstract Objective Acute mountain sickness (AMS) is caused by a low partial pressure of oxygen and may occur above 2500 m. The aim of this research was to evaluate olfactory and gustatory abilities of healthy subjects during baseline conditions and after seven hours of normobaric hypoxia. Methods Sixteen healthy subjects were assessed using the Sniffin’ Sticks, as well as intensity and pleasantness ratings. Gustatory function was evaluated utilizing the Taste Strips. Experiments were carried out under baseline conditions (518 m altitude) followed by a second testing session after seven hours of normobaric hypoxia exposure (comparable to 4000 m altitude). Results During normobaric hypoxia ol…
Effects of Recombinant Human Erythropoietin (rHuEPO) on Tumor Control in Patients with Cancer-Induced Anemia
2005
It is well recognized that anemia-induced tumor hypoxia is associated with a reduced sensitivity of tumors to radiation and some forms of chemotherapy. Thus, the correction of lower hemoglobin (Hb) concentrations with recombinant human erythropoietin (rHuEPO) can play an essential role by improving tumor oxygenation. Based on evidence from a number of trials, treatment with rHuEPO will effectively ameliorate anemia and improve quality of life. However, one of the most essential prerequisites for achieving this benefit is the use of rHuEPO in agreement with the evidence-based ASCO/ASH-guidelines recommending a target Hb concentration of 12 g/dl (7.44 mmol/l).
Hypoxia and Aggressive Tumor Phenotype: Implications for Therapy and Prognosis
2008
Abstract Tumor hypoxia, mostly resulting from poor perfusion and anemia, is one of the key factors in inducing the development of cell clones with an aggressive and treatment-resistant phenotype that leads to rapid progression and poor prognosis. Studies in patients with solid tumors suggest that there is a range of hemoglobin (Hb) concentrations that is optimum for tumor oxygenation. When used to achieve an Hb level within this range, erythropoiesis-stimulating agents (ESAs) can be expected to increase tumor oxygenation, and this may favorably influence sensitivity to treatment as well as quality of life. There is no robust evidence that ESAs, when used as indicated, have a negative effect…
Microregional expression of glucose transporter-1 and oxygenation status: lack of correlation in locally advanced cervical cancers.
2005
Abstract Purpose: Glucose transporter-1 (GLUT-1), a target gene of hypoxia-inducible factor-1, has been considered a candidate endogenous marker of tumor hypoxia. Expression of GLUT-1 may also serve as an indicator for the induction of the transcriptional response to hypoxia, which has been linked to enhanced proliferation, resistance to therapy, and metastatic propagation of cancer cells. Overexpression of GLUT-1 has been shown to correlate with poor prognosis in several tumor entities, among them cancers of the uterine cervix. The validity of these hypotheses is investigated. Experimental Design: The expression of GLUT-1 was assessed in 80 biopsies of Eppendorf oxygenation measurement tra…