Search results for " Oxygen"
showing 10 items of 1626 documents
Mitochondria as a Target for Future Diabetes Treatments
2015
Diabetes mellitus is rapidly becoming the world’s most dangerous serial killer. Type 1 diabetes (T1D) is a currently incurable autoimmune disease marked by progressive, and eventually exhaustive, destruction of the insulin-producing pancreatic beta cells. Type 2 diabetes (T2D) describes the combination of insulin resistance in peripheral tissue, insufficient insulin secretion from the pancreatic beta cells, and excessive glucagon secretion from the pancreatic alpha cells. T1D as well as severe cases of T2D are treated with insulin replacement, which can merely be considered as life support for the acute phases of the disease. Islet replacement of insulin-producing pancreatic beta cells repr…
Relationship between maximal fat oxidation and oxygen uptake: comparison between type 2 diabetes patients and healthy sedentary subjects
2014
The contribution of fat oxidation to energy production during exercise is influenced by intensity of exercise. The aim of this study was to assess the relationship between the highest value of fat oxidation rate (FATmax) and the oxygen uptake (VO2) in sedentary type 2 diabetes (T2D) patients vs healthy sedentary subjects. Sedentary T2D patients and healthy sedentary subjects were evaluated to a graded exercise test, and oxygen uptake and fat oxidation rate were detected. Data show that in T2D patients fat oxidation rate is not impaired and the positive linear correlation between FATmax and both VO2 and VO2max suggests that even in T2D patients the muscle oxidative capacity might increase in…
Mitochondrial complex I impairment in leukocytes from polycystic ovary syndrome patients with insulin resistance.
2009
Insulin resistance is a feature of polycystic ovary syndrome (PCOS) and is related to mitochondrial function.Our objective was to assess mitochondrial function by evaluating mitochondrial oxygen (O(2)) consumption, reactive oxygen species (ROS) production, levels of glutathione (GSH), the oxidized glutathione/GSH ratio, TNFalpha levels, and membrane potential. Additionally, we have evaluated mitochondrial complex I as a target of the oxidative stress responsible for PCOS in polymorphonuclear cells.This was a prospective controlled study conducted in an academic medical center.The study population consisted of 20 lean reproductive-age women with PCOS and 20 body composition-matched controls.…
Nitrate therapy: new aspects concerning molecular action and tolerance.
2011
Although the short-term vasodilatory properties of organic nitrates are potent and well known, a number of vascular and extravascular changes have been shown to compromise their hemodynamic effects on long-term administration. Among these changes, systemic phenomena such as neurohormonal activation and intravascular volume expansion1 as well as specific vascular changes such as increased vascular superoxide (O2·−) production,2 increased sensitivity to vasoconstrictors,3 and decreased responsiveness to nitric oxide (NO) donors4,5 have long been identified as playing a role. Several hypotheses have been proposed to explain these abnormalities, and over the last 15 years, our groups have focus…
Therapeutic Advances in Emergency Cardiology: Acute Pulmonary Embolism.
2019
Background Acute pulmonary embolism (PE) requires rapid diagnosis and early and appropriate treatment, often under conditions of hemodynamic instability. The therapeutic strategy should optimally integrate the therapeutic arsenal in a multidisciplinary but unitary approach. Areas of uncertainty The short list of the major uncertainties associated with acute PE should include limited general public awareness on venous thromboembolism, acute hemodynamic support not based on evidence from randomized clinical trials, with few updates lately, mainly linked to extracorporeal membrane oxygenation, thrombolytic therapy having firm indications only in high-risk PE, without clear strategies for parti…
Cardiopulmonary exercise testing in COVID-19 patients at 3 months follow-up☆
2021
Abstract Background Long-term effects of Coronavirus Disease of 2019 (COVID-19) are of utmost relevance. We aimed to determine: 1) the functional capacity of COVID-19 survivors by cardiopulmonary exercise testing (CPET); 2) the characteristics associated with cardiopulmonary exercise testing (CPET) performance; 3) the safety and tolerability of CPET. Methods We prospectively enrolled consecutive patients with laboratory-confirmed COVID-19 from Azienda Sanitaria Locale 3, Genoa. Three months after hospital discharge a complete clinical evaluation, trans-thoracic echocardiography, CPET, pulmonary function tests, and dominant leg extension (DLE) maximal strength measurement were performed. Res…
Managing Persistent Hypoxemia: what is new?
2017
Mechanical ventilation is the standard life-support technique for patients with severe acute respiratory failure. However, some patients develop persistent and refractory hypoxemia because their lungs are so severely damaged that they are unable to respond to the application of high inspired oxygen concentration and high levels of positive end-expiratory pressure. In this article, we review current knowledge on managing persistent hypoxemia in patients with injured lungs.
Mitochondrial complex I impairment in leukocytes from type 2 diabetic patients.
2011
Diabetes is associated with oxidative stress. This study evaluated the rates of oxidative stress and mitochondrial impairment in type 2 diabetes patients. The study population consisted of 182 diabetic patients and 50 body-composition- and age-matched controls. We assessed anthropometric and metabolic parameters and mitochondrial function by evaluating mitochondrial oxygen (O2) consumption, reactive oxygen species (ROS) production, glutathione (GSH) levels, GSH/GSSG ratio, mitochondrial membrane potential, and mitochondrial complex I activity in polymorphonuclear cells from diabetes type 2 patients. We found an increase in waist circumference and augmented serum levels of triglycerides, pro…
Exposure to ototoxic agents and hearing loss: A review of current knowledge
2014
Several experimental and clinical studies have shown that a variety of ototoxic agents (such as drugs, industrial chemicals and noise) can cause sensorineural hearing loss. The most common ototoxic drugs used in clinical practice include: aminoglycoside and macrolide antibiotics, quinoline anti-malarials, platinum analog antineoplastics, loop diuretics, and acetylsalicylic acid. Among chemical agents with potential ototoxic properties are: organic solvents, heavy metals, organotins, nitriles, asphyxiants, and pesticides/herbicides. Acoustic exposure to high intensity and/or prolonged noise can also cause permanent threshold shifts in auditory perception. Ototoxic agents can influence audito…
Unusual oxygen binding behavior of a 24-meric crustacean hemocyanin.
2009
Abstract Hemocyanins from Crustacea usually are found as 1 × 6 or 2 × 6-meric assemblies. An exception is the hemocyanin isolated from thalassinidean shrimps where the main component is a 24-meric structure. Our analysis of oxygen binding data of the thalassinidean shrimp Upogebia pusilla based on a three-state MWC-model revealed that despite the 24-meric structure the functional properties can be described very well based on the hexamer as allosteric unit. In contrast to the hemocyanins from other thalassinidean shrimps the oxygen affinity of hemocyanin from U. pusilla is increased upon addition of l -lactate. A particular feature of this hemocyanin seems to be that l -lactate already enha…