Search results for "oxygen"

Delivery of siHIF‐1α to Reconstruct Tumor Normoxic Microenvironment for Effective Chemotherapeutic and Photodynamic Anticancer Treatments

2021

The tumor hypoxic microenvironment not only induces genetic and epigenetic changes in tumor cells, immature vessels formation for oxygen demand, but also compromises the efficiency of therapeutic interventions. On the other hand, conventional therapeutic approaches which kill tumor cells or destroy tumor blood vessels to block nutrition and oxygen supply usually facilitate even harsher microenvironment. Thus, simultaneously relieving the strained response of tumor cells and blood vessels represents a promising strategy to reverse the adverse tumor hypoxic microenvironment. In the present study, an integrated amphiphilic system (RSCD) is designed based on Angiotensin II receptor blocker cand…

Differential regulation of hexameric and dodecameric hemocyanin from A. leptodactylus

2013

The oxygen binding properties of hemocyanins are regulated on a short time scale by effectors such as l-lactate, urate and protons, and on longer time scales by expression of the different types of subunits. For Astacus leptodactylus it was shown previously that acclimation to higher temperatures leads to increased levels of a 6-meric hemocyanin species, whereas at lower temperatures the 12-meric form prevails. Here we show that the temperature dependence of the two forms supports the idea, that the maintenance of high affinity towards oxygen is the driving force for the differential expression of these hemocyanins. Furthermore, the two different types of hemocyanin differ not only in the a…

Production and characterization of the recombinant Sphingomonas chlorophenolica pentachlorophenol 4-monooxygenase.

2001

Abstract Pentachlorophenol 4-monooxygenase (PCP4MO) from Sphingomonas chlorophenolica is a flavoprotein that hydroxylates PCP in the presence of NADPH and oxygen. In order to investigate the structure and function of active site, recombinant PCP4MO (rePCP4MO) was produced in Escherichia coli as a glutathione S-transferase (GST) fusion protein. Moreover, a tobacco etch virus (TEV) protease cleavage site (EKLYFQG) was introduced into GST-PCP4MO and a his-tagged TEV protease was employed. Hence, a two-step purification protocol was developed which allowed obtaining 15–20 mg of rePCP4MO from 1 L culture. The rePCP4MO revealed identity with native enzyme by SDS–PAGE and N-terminal sequence analy…

Evaluation of the Oxiris Membrane in Cardiogenic Shock Requiring Extracorporeal Membrane Oxygenation Support: Study Protocol for a Single Center, Sin…

2021

Background: Veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is the rescue treatment proposed to patients with refractory cardiogenic shock. The VA-ECMO implantation promotes inflammation and ischemia-reperfusion injuries through the VA-ECMO flow, causing digestive mucosa barrier disrupture and inducing translocation of bacterial wall components—Lipopolysaccharides (LPS) with further inflammation and circulatory impairment. LPS is a well-studied surrogate indicator of bacterial translocation. Oxiris membrane is a promising and well-tolerated device that can specifically remove LPS. The main study aim is to compare the LPS elimination capacity of Oxiris membrane vs. a non-absorban…

Heart rate recovery after exercise and maximal oxygen uptake in sedentary patients with type 2 diabetes

2015

Aims: Heart rate recovery after exercise (HRR) is an estimate of autonomic modulation of the heart, and has been shown to be inversely associated with insulin resistance, metabolic syndrome, and type 2 diabetes [1]. Type 2 diabetes is associated with poor exercise tolerance and maximal aerobic capacity (VO2max) [2]. Aim of our study was to assess the relationship between HRR and VO2max in sedentary patients with type 2 diabetes. Methods: Maximal treadmill exercise testing using standard or modified Bruce protocol was performed in 16 (8 males and 8 females) sedentary patients with type 2 diabetes (T2D), and in 16 (9 males and 7 females) age-matched sedentary non-diabetic controls (ND). HRR (…

Scanning Tunneling Spectroscope Use in Electrocatalysis Testing

2010

Published version of an article from the journal: Materials (1996-1944). Also available from publisher: http://dx.doi.org/10.3390/ma3063675 The relationship between the electrocatalytic properties of an electrode and its ability to transfer electrons between the electrode and a metallic tip in a scanning tunneling microscope (STM) is investigated. The alkaline oxygen evolution reaction (OER) was used as a test reaction with four different metallic glasses, Ni78Si8B14, Ni70Mo20Si5B5, Ni58Co20Si10B12, and Ni25Co50Si15B10, as electrodes. The electrocatalytic properties of the electrodes were determined. The electrode surfaces were then investigated with an STM. A clear relationship between the…

Mutacje w mitochondrialnym DNA i reaktywne formy tlenu jako czynniki wpływające na procesy starzenia się komórek i organizmów

2016

Oxygen Atom Transfer Catalysis by Dioxidomolybdenum(VI) Complexes of Pyridyl Aminophenolate Ligands

2021

A series of new cationic dioxidomolybdenum(VI) complexes [MoO2(Ln)]PF6 (2-5) with the tripodal tetradentate pyridyl aminophenolate ligands HL2-HL5 have been synthesized and characterized. Ligands HL2-HL4 carry substituents in the 4-position of the phenolate ring, viz. Cl, Br and NO2, respectively, whereas the ligand HL5, N-(2-hydroxy-3,5-di-tert-butylbenzyl)-N,N-bis(2-pyridylmethyl)amine, is a derivative of 3,5-di-tert-butylsalicylaldehyde. X-ray crystal structures of complexes 2, 3 and 5 reveal that they have a distorted octahedral geometry with the bonding parameters around the metal centres being practically similar. Stoichiometric oxygen atom transfer (OAT) properties of 5 with PPh3 wer…

Deficiency of Nrf2 accelerates the effector phase of arthritis and aggravates joint disease

2011

14 páginas, 8 figuras, 1 tabla.-- et al.

COX-2 expression in chondrosarcoma: A role for celecoxib treatment?

2010

Chondrosarcomas are resistant to conventional chemo- and radiotherapy. A subset of chondrosarcomas arises secondarily in the benign tumour syndromes enchondromatosis (EC) and multiple osteochondromas (MO), and prevention of tumour development would greatly improve prognosis. We therefore investigated the effect of selective COX-2 inhibition on chondrosarcoma growth. COX-2 expression was studied in central- and peripheral cartilaginous tumours. The effect of COX-2 inhibition was assessed in four high-grade chondrosarcoma cell lines using celecoxib and NS-398 treatment. COX-2 activity (prostaglandin E-2 (PGE(2)) ELISA) and cell viability were measured. The (prophylactic) effect of celecoxib o…