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Glycerol To Glucose

Formation Of Glycerol From Glucose In Rat Brain And Cultured Brain Cells. Augmentation With Kainate Or Ischemia

Formation Of Glycerol From Glucose In Rat Brain And Cultured Brain Cells. Augmentation With Kainate Or Ischemia

Ischemic stroke and neonatal hypoxic-ischemic encephalopathy are two of the leading causes of disability in adults and infants. The energy demands of the brain are provided by mitochondrial oxidative phosphorylation. Ischemia/reperfusion (I/R) affects the production of ATP in brain mitochondria, leading to energy failure and death of the affected tissue. Among the enzymes of the mitochondrial respiratory chain, mitochondrial complex I is the most sensitive to I/R; however, the mechanisms of its inhibition are poorly understood. This article reviews some of the existing data on the mitochondria impairment during I/R and proposes two distinct mechanisms of complex I damage emerging from recent studies. One mechanism is a reversible dissociation of natural flavin mononucleotide cofactor from the enzyme I after ischemia. Another mechanism is a modification of critical cysteine residue of complex I involved into the active/deactive conformational transition of the enzyme. I describe potential effects of these two processes in the development of mitochondrial I/R injury and briefly discuss possible neuroprotective strategies to ameliorate I/R brain injury. Reactive oxygen species (ROS) are byproducts of physiological mitochondrial metabolism that are involved in several cellular signaling pathways as well as tissue injury and pathophysiological processes, including brain ischemiareperfusion injury. The mitochondrial respiratory chain is considered a major source of ROS; however, there is little agreement on how ROS release depends on oxygen concentration.The rate of H2O2 release by intact brain mitochondria was measured with an Amplex UltraRed assay using a highresolution respirometer (Oroboros) equipped with a fluorescent optical module and a system of controlled gas flow f Continue reading >>

Fat To Glycerol To Glucose

Fat To Glycerol To Glucose

Fat to Glycerol to Glucose , 08-26-2009 11:18 PM ! ! ! I have been pursuing a low card woe for 8 months and have maintained the same weight basically since just after the first 2 weeks. Maintain carbs at 20 grams per day. Getting desperate. Got the book The metabolism Miracle by Diane Kress. She says basically that you body will use dietary fat for energy before it will use it's own fat stores. I'm confused. So I have done some reading online. Learning that dietary fat is turned into glycerol and then turned into glucose. So this tells me that dietary fat should be carefully controlled or at the very least you won't lose weight. I know there are some really smart people on this discussion board and I would really appreciate any information you can share. RE: Fat to Glycerol to Glucose , 08-27-2009 10:23 AM I'm confused. So I have done some reading online. Learning that dietary fat is turned into glycerol and then turned into glucose. So this tells me that dietary fat should be carefully controlled or at the very least you won't lose weight. I know there are some really smart people on this discussion board and I would really appreciate any information you can share. Your body's main energy "currency" is glucose. Even if you never ingested a carb, your body makes its own glucose, and if your BG gets much below 70 you'll feel the symptoms of low BG (shaky, weak, etc.) Fats (ingested and stored) are triglycerides. Glycerol is the small backbone connecting 3 fatty acids. Our bodies use the fatty acids for energy by oxidizing them (serially lopping off carbon fragments to form acyl CoA). For every gram of fat, the glycerol is a teeeeeeeeeny part -- kind of like the an artificial sweetener amount of grams if that makes any sense. I would not worry at all about regulating fat Continue reading >>

Cory Cycle , Glucose-alanine Cycle And Glycerol-glucose Cycle

Cory Cycle , Glucose-alanine Cycle And Glycerol-glucose Cycle

... cortisol, growth hormone, thyreoid hormones (T3 and T4) and many others. The proper functions of these hormones is precise control of glucose concentration in the blood. Insulin and glucagon are two major hormones involved in regulation of blood glucose level. They are both secreted in response to blood sugar levels, but in opposite fashion. At the same time, enhanced insulin secretion induced increased glucagon secretion. Insulin has a hypoglycemic effect. Secretion of insulin is a response to increased glucose level in the blood. In addition to the direct effects of hyperglycemia in enhancing the uptake of glucose into both the liver and peripheral tissues, the hormon insulin plays a central role in the regulation of the blood glucose concentration. Similarly, as blood glucose falls, the amount of insulin secreted by the pancreatic islets goes down. Glucagon, as a direct antagonist of insulin, has a hyperglycemic effect. Secretion of glucagon is a response to decreased glucose level in the blood (Chattoraj & Watts,1986; Ginsberg, 1990 a, 1990b; Mayes,1975; King, 2011). Insulin is a small protein consisting of an alpha chain of 21 amino acids linked by two disulfide (SS) bridges to a beta chain of 30 amino acids. The precursor of insulin is a proinsulin, which contains C peptide (conective peptide). The conversion of proinsulin to insulin requires biologic proteolysis (Ginsberg,1990; Bowen, 2010; Harper, 1975; Chattoraj & Watts,1986). The stimulus for insulin secretion is a high blood glucose. Insulin is produced by cells of Langerhans islets in pancreas and is secreted into the blood as a direct response to hyperglycemuia. Beta cells have channels in their plasma membrane that serve as glucose detectors. When blood glucose levels rise (after a meal), insulin is s Continue reading >>

Formation Of Glycerol From Glucose In Rat Brain And Cultured Brain Cells. Augmentation With Kainate Or Ischemia

Formation Of Glycerol From Glucose In Rat Brain And Cultured Brain Cells. Augmentation With Kainate Or Ischemia

Formation of glycerol from glucose in rat brain and cultured brain cells. Augmentation with kainate or ischemia Address correspondence and reprint requests to Bjrnar Hassel, Norwegian Defence Research Establishment, P.O. Box 25, N2027 Kjeller, Norway. Email: [email protected] This paper is dedicated to the memory of Professor Herman S. Bachelard, who inspired this work. Please review our Terms and Conditions of Use and check box below to share full-text version of article. I have read and accept the Wiley Online Library Terms and Conditions of Use. Use the link below to share a full-text version of this article with your friends and colleagues. Learn more. An increase in the concentration of glycerol in the ischemic brain is assumed to reflect degradation of phospholipids of plasma membranes. However, glycerol could, theoretically, be formed from glucose, which after glycolytic conversion to dihydroxyacetone phosphate, could be converted to glycerol3phosphate and hence to glycerol. We show here that 13Clabeled glycerol accumulate in incubation media of cultured cerebellar granule cells and astrocytes incubated with [13C]glucose, 3 mmol/L, demonstrating the formation of glycerol from glucose. Coincubation of cerebellar granule cells with kainate, 50 mol/L, led to increased glucose metabolism and increased accumulation of [13C]glycerol. Accumulation of [13C]glycerol and its precursor, [13C]glycerol3phosphate, was evident in brain, but not in serum, of kainatetreated rats that received [U13C]glucose, 5 mol/g bodyweight, intravenously and survived for 5 min. Global ischemia induced by decapitation also caused accumulation of [13C]glycerol and [13C]glycerol3phosphate. These results show that glycerol can be formed from glucose in brain; they also demonstrate the existen Continue reading >>

Glycerol Is Synthesized And Secreted By Adipocytes To Dispose Of Excess Glucose, Via Glycerogenesis And Increased Acyl-glycerol Turnover

Glycerol Is Synthesized And Secreted By Adipocytes To Dispose Of Excess Glucose, Via Glycerogenesis And Increased Acyl-glycerol Turnover

Article | Open Glycerol is synthesized and secreted by adipocytes to dispose of excess glucose, via glycerogenesis and increased acyl-glycerol turnover Scientific Reportsvolume7, Articlenumber:8983 (2017) White adipose tissue (WAT) produces large amounts of lactate and glycerol from glucose. We used mature epididymal adipocytes to analyse the relative importance of glycolytic versus lipogenic glycerol in adipocytes devoid of external stimuli. Cells were incubated (24/48 h) with 7/14 mM glucose; half of the wells contained 14C-glucose. We analysed glucose label fate, medium metabolites, and the expression of key genes coding for proteins controlling glycerol metabolism. The effects of initial glucose levels were small, but time of incubation increased cell activity and modified its metabolic focus. The massive efflux of lactate was uniform with time and unrelated to glucose concentration; however, glycerol-3P synthesis was higher in the second day of incubation, being largely incorporated into the glycerides-glycerol fraction. Glycerophosphatase expression was not affected by incubation. The stimulation of glycerogenic enzymes expression was mirrored in lipases. The result was a shift from medium glycolytic to lipolytic glycerol released as a consequence of increased triacylglycerol turnover, in which most fatty acids were recycled. Production of glycerol seems to be an important primary function of adipocytes, maintained both by glycerogenesis and acyl-glycerol turnover. Production of 3C fragments may also contribute to convert excess glucose into smaller, more readily usable, 3C metabolites. Intact white adipose tissue (WAT) (and isolated adipocytes) secrete significant amounts of glycerol 1 . It has been long assumed that this glycerol is a by-product of lipolysis, r Continue reading >>

Glucose Can Be Synthesized From Noncarbohydrate Precursors - Biochemistry - Ncbi Bookshelf

Glucose Can Be Synthesized From Noncarbohydrate Precursors - Biochemistry - Ncbi Bookshelf

Glucose is formed by hydrolysis of glucose 6-phosphate in a reaction catalyzed by glucose 6-phosphatase. We will examine each of these steps in turn. 16.3.2. The Conversion of Pyruvate into Phosphoenolpyruvate Begins with the Formation of Oxaloacetate The first step in gluconeogenesis is the carboxylation of pyruvate to form oxaloacetate at the expense of a molecule of ATP . Then, oxaloacetate is decarboxylated and phosphorylated to yield phosphoenolpyruvate, at the expense of the high phosphoryl-transfer potential of GTP . Both of these reactions take place inside the mitochondria. The first reaction is catalyzed by pyruvate carboxylase and the second by phosphoenolpyruvate carboxykinase. The sum of these reactions is: Pyruvate carboxylase is of special interest because of its structural, catalytic, and allosteric properties. The N-terminal 300 to 350 amino acids form an ATP -grasp domain ( Figure 16.25 ), which is a widely used ATP-activating domain to be discussed in more detail when we investigate nucleotide biosynthesis ( Section 25.1.1 ). The C -terminal 80 amino acids constitute a biotin-binding domain ( Figure 16.26 ) that we will see again in fatty acid synthesis ( Section 22.4.1 ). Biotin is a covalently attached prosthetic group, which serves as a carrier of activated CO2. The carboxylate group of biotin is linked to the -amino group of a specific lysine residue by an amide bond ( Figure 16.27 ). Note that biotin is attached to pyruvate carboxylase by a long, flexible chain. The carboxylation of pyruvate takes place in three stages: Recall that, in aqueous solutions, CO2 exists as HCO3- with the aid of carbonic anhydrase (Section 9.2). The HCO3- is activated to carboxyphosphate. This activated CO2 is subsequently bonded to the N-1 atom of the biotin ring to Continue reading >>

Gluconeogenesis

Gluconeogenesis

Not to be confused with Glycogenesis or Glyceroneogenesis. Simplified Gluconeogenesis Pathway Gluconeogenesis (GNG) is a metabolic pathway that results in the generation of glucose from certain non-carbohydrate carbon substrates. From breakdown of proteins, these substrates include glucogenic amino acids (although not ketogenic amino acids); from breakdown of lipids (such as triglycerides), they include glycerol (although not fatty acids); and from other steps in metabolism they include pyruvate and lactate. Gluconeogenesis is one of several main mechanisms used by humans and many other animals to maintain blood glucose levels, avoiding low levels (hypoglycemia). Other means include the degradation of glycogen (glycogenolysis)[1] and fatty acid catabolism. Gluconeogenesis is a ubiquitous process, present in plants, animals, fungi, bacteria, and other microorganisms.[2] In vertebrates, gluconeogenesis takes place mainly in the liver and, to a lesser extent, in the cortex of the kidneys. In ruminants, this tends to be a continuous process.[3] In many other animals, the process occurs during periods of fasting, starvation, low-carbohydrate diets, or intense exercise. The process is highly endergonic until it is coupled to the hydrolysis of ATP or GTP, effectively making the process exergonic. For example, the pathway leading from pyruvate to glucose-6-phosphate requires 4 molecules of ATP and 2 molecules of GTP to proceed spontaneously. Gluconeogenesis is often associated with ketosis. Gluconeogenesis is also a target of therapy for type 2 diabetes, such as the antidiabetic drug, metformin, which inhibits glucose formation and stimulates glucose uptake by cells.[4] In ruminants, because dietary carbohydrates tend to be metabolized by rumen organisms, gluconeogenesis occurs Continue reading >>

Glycerol Production From Glucose And Fructose By 3t3-l1 Cells: A Mechanism Of Adipocyte Defense From Excess Substrate

Glycerol Production From Glucose And Fructose By 3t3-l1 Cells: A Mechanism Of Adipocyte Defense From Excess Substrate

Click through the PLOS taxonomy to find articles in your field. For more information about PLOS Subject Areas, click here . Glycerol Production from Glucose and Fructose by 3T3-L1 Cells: A Mechanism of Adipocyte Defense from Excess Substrate Affiliations Department of Nutrition and Food Science, Faculty of Biology, University of Barcelona, Av.Diagonal 643, 08028, Barcelona, Spain, Institute of Biomedicine, University of Barcelona, Barcelona, Spain, CIBER Obesity and Nutrition, Barcelona, Spain Affiliation Department of Nutrition and Food Science, Faculty of Biology, University of Barcelona, Av.Diagonal 643, 08028, Barcelona, Spain Affiliations Department of Nutrition and Food Science, Faculty of Biology, University of Barcelona, Av.Diagonal 643, 08028, Barcelona, Spain, Institute of Biomedicine, University of Barcelona, Barcelona, Spain, CIBER Obesity and Nutrition, Barcelona, Spain Affiliations Department of Nutrition and Food Science, Faculty of Biology, University of Barcelona, Av.Diagonal 643, 08028, Barcelona, Spain, Institute of Biomedicine, University of Barcelona, Barcelona, Spain, CIBER Obesity and Nutrition, Barcelona, Spain Continue reading >>

Propionic Acid Fermentation Of Glycerol And Glucose By Propionibacterium Acidipropionici And Propionibacterium Freudenreichii Ssp.shermanii

Propionic Acid Fermentation Of Glycerol And Glucose By Propionibacterium Acidipropionici And Propionibacterium Freudenreichii Ssp.shermanii

A comparative study was carried out in anaerobic batch cultures on 20 g/l of either glycerol or glucose using two propionibacteria strains, Propionibacterium acidipropionici and Propionibacterium freudenreichii ssp. shermanii. In all cases, fermentation end-products were the same and consisted of propionic acid as the major product, acetic acid as the main by-product and two minor metabolites, n-propanol and succinic acid. Evidence was provided that greater production of propionic acid by propionibacteria was obtained with glycerol as carbon and energy sources. P. acidipropionici showed higher efficiency in glycerol conversion to propionic acid with a faster substrate consumption (0.64 g l1 h1) and a higher propionic acid production (0.42 g l1 h1 and 0.79 mol/mol). The almost exclusive production of propionic acid from glycerol by this bacterium suggested an homopropionic tendency of this fermentation. Acetic acid final concentration was two times lower on glycerol (2 g/l) than on glucose (4 g/l) for both micro-organisms. P. freudenreichii ssp. shermanii exhibited a glycerol fermentation pattern typical of non-associated glycerol-consumption-product formation. This could indicate a particular metabolism for P. freudenreichii ssp. shermanii oriented towards the production of other specific components. These results tend to show that glycerol could be an excellent alternative to conventional carbon sources such as carbohydrates for propionic acid production. FermentationPropionic AcidSuccinic AcidGlycerol ConversionExclusive Production These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves. Received: 21 May 1999 / Accepted: 1 November 1999 This is a preview of subscripti Continue reading >>

Glycerol Diffusion In Skin At Glucose Impact On Tissue

Glycerol Diffusion In Skin At Glucose Impact On Tissue

Glycerol diffusion in skin at glucose impact on tissue Abstract: In this paper we present results of experimental study of glucose impact on skin tissue by testing tissue structure alteration at glycerol diffusivity. The measurements have been performed using Ocean Optics spectrometer USB4000 in transmittance mode. In the in vitro experiments twenty samples of intact rat skin were used. Transmittance of ten samples was measured immediately after obtaining the samples concurrently with administration of 58% aqueous glycerol solution in the spectral range 400-1000 nm. The second group of the rat skin samples (ten samples) was incubated during 24 hours in 40%-glucose solution and during 24 hours in physiological solution. After that transmittance of the ten samples was measured concurrently with administration of the 58%- glycerol solution. Special computer program has been developed for processing of the experimental data and estimation of the glycerol diffusion rate. Degree of optical clearing of intact skin samples and skin samples previously immersed in glucose solution were estimated and compared. As a result we found that the optical clearing of intact skin increases about 3 times faster in comparison with skin immersed in the glucose solution. Continue reading >>

Glycerol Kinase Interacts With Nuclear Receptor Nr4a1 And Regulates Glucose Metabolism In The Liver

Glycerol Kinase Interacts With Nuclear Receptor Nr4a1 And Regulates Glucose Metabolism In The Liver

Glycerol kinase interacts with nuclear receptor NR4A1 and regulates glucose metabolism in the liver *Beijing Institute of Radiation Medicine, Beijing, China; Graduate School, Anhui Medical University, Hefei, China; 1These authors contributed equally to this work. Institute of AcuMoxibustion, China Academy of Chinese Medical Sciences, Beijing, China; State Key Laboratory of Proteomics, Beijing Proteome Research Center, National Center for Protein Sciences, Beijing Institute of Lifeomics, Beijing, China; and 1These authors contributed equally to this work. *Beijing Institute of Radiation Medicine, Beijing, China; Department of Pharmaceutical Engineering, Tianjin University, Tianjin, China *Beijing Institute of Radiation Medicine, Beijing, China; Graduate School, Anhui Medical University, Hefei, China; State Key Laboratory of Proteomics, Beijing Proteome Research Center, National Center for Protein Sciences, Beijing Institute of Lifeomics, Beijing, China; and Department of Pharmaceutical Engineering, Tianjin University, Tianjin, China *Beijing Institute of Radiation Medicine, Beijing, China; Graduate School, Anhui Medical University, Hefei, China; Glycerol kinase (Gyk), consisting of 4 isoforms, plays a critical role in metabolism by converting glycerol to glycerol 3-phosphate in an ATP-dependent reaction. Only Gyk isoform b is present in whole cells, but its function in the nucleus remains elusive. Previous studies have shown that nuclear orphan receptor subfamily 4 group A member (NR4A)-1 is an important regulator of hepatic glucose homeostasis and lipid metabolism in adipose tissue. We aimed to elucidate the functional interaction between nuclear Gyk and NR4A1 during hepatic gluconeogenesis in the unfed state and diabetes. We identified nuclear Gyk as a novel corepress Continue reading >>

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An Error Occurred Setting Your User Cookie

An Error Occurred Setting Your User Cookie This site uses cookies to improve performance. If your browser does not accept cookies, you cannot view this site. There are many reasons why a cookie could not be set correctly. Below are the most common reasons: You have cookies disabled in your browser. You need to reset your browser to accept cookies or to ask you if you want to accept cookies. Your browser asks you whether you want to accept cookies and you declined. To accept cookies from this site, use the Back button and accept the cookie. Your browser does not support cookies. Try a different browser if you suspect this. The date on your computer is in the past. If your computer's clock shows a date before 1 Jan 1970, the browser will automatically forget the cookie. To fix this, set the correct time and date on your computer. You have installed an application that monitors or blocks cookies from being set. You must disable the application while logging in or check with your system administrator. This site uses cookies to improve performance by remembering that you are logged in when you go from page to page. To provide access without cookies would require the site to create a new session for every page you visit, which slows the system down to an unacceptable level. This site stores nothing other than an automatically generated session ID in the cookie; no other information is captured. In general, only the information that you provide, or the choices you make while visiting a web site, can be stored in a cookie. For example, the site cannot determine your email name unless you choose to type it. Allowing a website to create a cookie does not give that or any other site access to the rest of your computer, and only the site that created the cookie can read it. Continue reading >>

Effects Of Insulin, Glucose And Glycerol On Fat Metabolism In Alloxan-diabetic Sheep

Effects Of Insulin, Glucose And Glycerol On Fat Metabolism In Alloxan-diabetic Sheep

EFFECTS OF INSULIN, GLUCOSE AND GLYCEROL ON FAT METABOLISM IN ALLOXAN-DIABETIC SHEEP The effects of insulin, glucose injection and oral glycerol on blood or plasma levels of glucose, free fatty acids (FFA), acetic acid and ketone bodies have been studied in alloxan-diabetic sheep. Insulin (05 i.u./kg.) lowered glucose levels only slightly, but induced a prompt and marked fall in FFA and acetate levels; ketones declined steadily after the first hour. The rate of utilization of injected glucose was considerably slower in diabetic than in non-diabetic sheep. FFA levels did not decline after glucose injection, while acetate levels declined slowly. Ketone levels were not affected significantly. Glycerol (180 ml.) per os reduced acetate and ketone levels, while tending to increase FFA values. Blood glucose also increased considerably. These data are consistent with present knowledge of the metabolic lesions in severe diabetes. However, it is concluded that there is impairment of acetate and, probably, ketone oxidation in severe diabetic ketosis. Finally, the metabolic changes recorded are compared with those which occur after insulin, glucose or glycerol administration to ewes showing clinical signs of ovine pregnancy toxaemia following severe and prolonged undernourishment in late pregnancy. Continue reading >>

Assessment Of Bio-hydrogen Production From Glycerol And Glucose By Fermentative Bacteria | Dimanta | Energetika

Assessment Of Bio-hydrogen Production From Glycerol And Glucose By Fermentative Bacteria | Dimanta | Energetika

Assessment of bio-hydrogen production from glycerol and glucose by fermentative bacteria I. Dimanta, V. Nikolajeva, A. Gruduls, I. Muinieks, J. Kleperis Microorganisms are capable to produce hydrogen during fermentation of organic substrates and industrial waste products can be used as feedstock for hydrogen producing bacteria. One of the substrates that can be effectively used for microbial hydrogen production is glycerol, which is a by-product from the process of biodiesel production, but glucose is mainly used as a model substrate. Different bacterial isolates were tested for hydrogen gas production rates from glucose and glycerol with test-systems constructed in our laboratory. Test-systems were optimised to allow adequate substrate and bacterial strain hydrogen productivity estimation in the liquid and gaseous phases. It was concluded that several of the isolated bacterial strains are suitable for bio-hydrogen production using glycerol as a substrate. Assessment was developed to establish whether microbial conversion of glycerol is an economically and environmentally viable possibility for bio-hydrogen production. The raw material cost noticeably decreases because of large quantities of available crude glycerol after biodiesel production and the highly reduced nature of carbon in glycerol perse. Continue reading >>

Glyceroneogenesis And The Source Of Glycerol For Hepatic Triacylglycerol Synthesis In Humans*

Glyceroneogenesis And The Source Of Glycerol For Hepatic Triacylglycerol Synthesis In Humans*

[2H]water, 99.9%2H, and [1,2,3-13C3]glycerol, 99% 13C, were obtained from Isotech, Inc. (Miamisburg, OH). The respective contributions of plasma glycerol and pyruvate were quantified in two separate groups of nonpregnant and pregnant women. Written informed consent was obtained from each woman and her spouse (when available) after fully explaining the procedure. The protocol was approved by the Institutional Review Board of the University Hospitals of Cleveland. Glycerol Incorporation in Triacylglycerol [1,2,3-13C]Glycerol (over 99%13C) was infused in five normal nonpregnant women after an overnight fast. They were physically healthy and had a negative history of diabetes or other metabolic disorders in their family. The tracer glycerol was dissolved in normal saline, sterilized by Millipore filtration, and tested for pyrogenicity and sterility. All subjects reported to the Clinical Research Center at University of Hospitals of Cleveland following a 12-h fast. The tracer was infused at a constant rate of 0.03 mg/kg of body weight/min for a period of 5 h, following a priming dose of 0.5 mg/kg. Arterialized blood samples were obtained in heparinized syringes from the opposite arm at 30-min intervals starting at 1 h. Blood samples were centrifuged immediately, and the plasma samples were stored at 70 C until analysis. Pyruvate Incorporation into Triacylglycerol The contribution of pyruvate to glycerol in triacylglycerol was evaluated using the total body water labeling method described for determining the rate of gluconeogenesis in vivo ( 12 , 13 ). The volunteers had been studied previously, and the details of the experimental design and the data on glucose turnover and gluconeogenesis have been reported previously ( 12 ). Plasma samples for the quantification of glycero Continue reading >>

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