Search results for "Glucose-6-Phosphate"
showing 10 items of 17 documents
Modulating Oxidant Levels to Promote Healthy Aging
2020
Significance: Free radicals although originally thought of as damaging molecules, inevitable side effects of the utilization of oxygen by cells, are now considered as signals that by modifying, among others, the thiol-disulfide balance regulate many cell processes from metabolism to cell cycle. Recent Advances: This review discusses the importance of the modulation of the oxidant levels through physiological strategies such as physical exercise or genetic manipulations such as the overexpression of antioxidant enzymes, in the promotion of healthy aging. Critical Issues: We have divided the review into five different sections. In the first two sections of the article "Oxidants are signals" a…
Overexpression of glucose 6 phosphate dehydrogenase preserves mouse pancreatic beta cells function until late in life.
2021
NAD(P)H donates electrons for reductive biosynthesis and antioxidant defense across all forms of life. Glucose-6- phosphate dehydrogenase (G6PD) is a critical enzyme to provide NADPH. G6PD deficiency is present in more than 400 million people worldwide. This enzymopathy provides protection against malaria but sensitizes cells to oxidative stressors. Oxidative stress has been involved in the pathogenesis of the diabetic complications and several studies have provided evidences of a link between G6PD deficiency and type 2 diabetes (T2D). We hypothesized that a moderate overexpression of G6PD (G6PD-Tg) could protect β-cells from age-associated oxidative stress thus reducing the risk of develop…
Safe neoadjuvant trastuzumab-based treatment in HER2 + inflammatory early breast cancer in a glucose 6-phosphate dehydrogenase-deficient postmenopaus…
2019
Introduction Glucose 6-phosphate dehydrogenase (G6PD) is a basic antioxidant pathway for erythrocytes, being its deficiency the most common gene mutation worldwide. As breast cancer is one of the most frequent tumors, many of these patients may present with G6PD deficiency prior treatment without notice. Case report We present the case of a woman deficient for G6PD with the diagnosis of Stage IIIB (cT4d cN1 cM0) HER2-enriched early breast cancer. Management and outcome The patient underwent neoadjuvance with trastuzumab and anthracycline-free chemotherapy, based on docetaxel (75 mg/m2, 120 mg) and carboplatin (AUC 5, 560 mg). She did not present hemolytic crisis and no blood transfusions we…
Influence of Software Tool and Methodological Aspects of Total Metabolic Tumor Volume Calculation on Baseline [18F]FDG PET to Predict Survival in Hod…
2015
Aim To investigate the respective influence of software tool and total metabolic tumor volume (TMTV0) calculation method on prognostic stratification of baseline 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography ([18F]FDG-PET) in newly diagnosed Hodgkin lymphoma (HL). Methods 59 patients with newly diagnosed HL were retrospectively included. [18F]FDG-PET was performed before any treatment. Four sets of TMTV0 were calculated with Beth Israel (BI) software: based on an absolute threshold selecting voxel with standardized uptake value (SUV) >2.5 (TMTV02.5), applying a per-lesion threshold of 41% of the SUVmax (TMTV041) and using a per-patient adapted threshold based on SUVmax of the…
Augmented glucose-6-phosphate dehydrogenase activity and normal penetration and metabolism of dehydroepiandrosterone in mononuclear leukocytes in pso…
1986
The aim of the study was to determine a biochemical basis for the augmented oxidative metabolism found in mononuclear leukocytes (MNL) of patients with active psoriasis. Dehydroepiandrosterone (DHEA) is known to inhibit glucose-6-phosphate dehydrogenase (G-6-PDH). We determined the activity of G-6-PDH as well as the penetration and metabolism of DHEA - diminished plasma concentrations of which have been found in psoriatics previously - in 16 patients with active psoriasis and 16 controls. MNL in patients with psoriasis possessed 52% more (p less than 0.05) G-6-PDH activity, based on cell number, and 34% more (p less than 0.05) activity, based on soluble protein. No difference in DHEA penetr…
Heterodimerization of Two Pathological Mutants Enhances the Activity of Human Phosphomannomutase2
2015
The most frequent disorder of glycosylation is due to mutations in the gene encoding phosphomannomutase2 (PMM2-CDG). For this disease, which is autosomal and recessive, there is no cure at present. Most patients are composite heterozygous and carry one allele encoding an inactive mutant, R141H, and one encoding a hypomorphic mutant. Phosphomannomutase2 is a dimer. We reproduced composite heterozygosity in vitro by mixing R141H either with the wild type protein or the most common hypomorphic mutant F119L and compared the quaternary structure, the activity and the stability of the heterodimeric enzymes. We demonstrated that the activity of R141H/F119L heterodimers in vitro, which reproduces t…
The effect of mixing on glucose fermentation by Zymomonas mobilis continuous culture
2003
Abstract The influence of mixing (in the range from 300 to 1100 rpm) on the performance of Zymomonas mobilis anaerobic continuous culture was studied. Biomass yield and ethanol productivity were improved at higher stirring intensities, in parallel with a decrease in byproduct synthesis. A mixing-dependent formation of minor amounts of fructose was first demonstrated in Z. mobilis anaerobic culture on glucose. The rate of fructose synthesis and the specific activity of the key enzyme in the pathway to fructose, phosphoglucose isomerase (EC 5.3.1.9), had a maximum at 700 rpm.
Chemo-enzymatic Conversion of Glucose in 5-Hydroxymethylfurfural: The Joint Effect of Ionic Liquids and Ultrasound
2020
For the valorization of lignocellulosic biomass, a key step is unlocking the conversion of glucose to suitable chemical platforms. To this aim, we herein describe the sequential chemo-enzymatic conversion of glucose into 5-hydroxymethylfurfural (5-HMF), in two steps: glucose isomerization to fructose, catalyzed by glucose isomerase (GI) and fructose dehydration to 5-HMF promoted by Amberlyst 15. The novelty of our approach lies in the use of crude cell extracts of Streptomyces coelicolor showing GI activity, as isomerization catalysts, along with a commercial immobilized GI. Under optimized reaction conditions, we obtained a conversion to 5-HMF (C5‑HMF) from glucose of 50% in the H2O/[bmim]…
Untersuchungen �ber den Hemmfaktor der Phosphoglucose-Isomerase in Erythrocyten von Kranken mit florider Psoriasis vulgaris
1967
Die Untersuchungen uber Herkunft und Beschaffenheit des Hemmkorpers der PGI von Kranken mit florider Psoriasis vulgaris haben ergeben, das es sich um ein nur in der Zelle, in diesem Falle im Erythrocyten, nicht aber im Serum solcher Kranker vorliegendes Protein handelt.
The desert gerbil Psammomys obesus as a model for metformin-sensitive nutritional type 2 diabetes to protect hepatocellular metabolic damage: Impact …
2017
Introduction While metformin (MET) is the most widely prescribed antidiabetic drug worldwide, its beneficial effects in Psammomys obesus (P. obesus), a rodent model that mimics most of the metabolic features of human diabetes, have not been explored thoroughly. Here, we sought to investigate whether MET might improve insulin sensitivity, glucose homeostasis, lipid profile as well as cellular redox and energy balance in P. obesus maintained on a high energy diet (HED). Materials and methods P. obesus gerbils were randomly assigned to receive either a natural diet (ND) consisting of halophytic plants (control group) or a HED (diabetic group) for a period of 24 weeks. MET (50 mg/kg per os) was…