Assessing glucose 6-phosphate dehydrogenase activity in children with acute lymphoblastic leukemia and its relationship to disease activity.

Detection of Common Chimeric Fusion Transcripts in Acute Lymphoblastic Leukemia (ALL) Patients Using Multiplex Reverse Transcriptase Polymerase Chain Reaction Assay: A North Indian Tertiary Care Centre Experience

BackgroundScreening for G6PD deficiency in newborns can help prevent severe hemolysis, hyperbilirubinemia, and bilirubin encephalopathy, as recommended by the World Health Organization (WHO). It has been speculated that the presence of a high number of reticulocytes in newborns interferes with the diagnosis of G6PD deficiency since reticulocytes contain higher amounts of G6PD enzyme than mature erythrocytes. Therefore, the purposes of this study were to assess the effect of reticulocytosis in the determination of blood G6PD activity in Thai newborns by using a novel automated UV-based enzymatic assay and to validate the performance of this assay for the detection of G6PD deficiency in newborn samples.MethodsThe levels of reticulocytes and G6PD activity were measured in blood samples collected from 1,015 newborns. G6PD mutations were identified using TaqMan® SNP genotyping assay, PCR–restriction fragment length polymorphism (PCR–RFLP), and direct sequencing. The correlation between the levels of reticulocytes and G6PD activity was examined. The performance of the automated method was compared with that of the fluorescent spot test (FST) and the standard quantitative assay.ResultsThe automated assay detected G6PD deficiency in 6.5% of the total newborn subjects compared to 5.3% and 6.1% by the FST and the standard method, respectively. The minor allele frequencies (MAFs) of G6PD ViangchanG871A, G6PD MahidolG487A, and G6PD UnionC1360T were 0.066, 0.005, and 0.005, respectively. The reticulocyte counts in newborns with G6PD deficiency were significantly higher than those in normal male newborns (p < 0.001). Compared with normal newborns after controlling for thalassemias and hemoglobinopathies, G6PD-deficient patients with the G6PD ViangchanG871A mutation exhibited elevated reticulocyte counts (5.82 ± 1.73%, p < 0.001). In a group of G6PD normal newborns, the percentage of reticulocytes was positively correlated with G6PD activity (r = 0.327, p < 0.001). However, there was no correlation between G6PD activity and the levels of reticulocytes in subjects with G6PD deficiency (r = -0.019, p = 0.881). The level of agreement in the detection of G6PD deficiency was 0.999, while the area under the receiver operating characteristic (AUC) curve demonstrated that the automated method had 98.4% sensitivity, 99.5% specificity, 92.4% positive predictive value (PPV), 99.9% negative predictive value (NPV), and 99.4% accuracy.ConclusionsWe report that reticulocytosis does not have a statistically significant effect on the detection of G6PD deficiency in newborns by both qualitative and quantitative methods.

Clostridium difficile infection (CDI) is a bacterial infection of the digestive tract. Acute infections are accompanied by increased risk for venous thromboembolism (VTE). To date, there have been no studies of the rheological properties of blood during the course of digestive tract infections. The aim of our study was to examine the effects of CDI on red blood cell (RBC) rheology, specifically RBC deformability, RBC aggregation, and plasma viscosity. In addition, the activity of glucose 6 phosphate dehydrogenase (G6PD) and acetylcholinesterase (AChE) in RBC was studied. Our study group included 20 patients with CDI, 20 healthy persons comprised the control group. We examined the effects of CDI on the rheology of RBCs, their deformability and aggregation, using a Laser-assisted Optical Rotational Cell Analyzer (LORCA). Plasma viscosity was determined using a capillary tube plasma viscosymeter. Moreover, we estimated the activity of AChE and G6PD in RBC using spectrophotometric method. A statistically significant increase was found in the aggregation index, viscosity and activity of G6PD whereas the amount of time to reach half of maximum aggregation (t½) and the amplitude of aggregation (AMP) both showed statistically significantly decreases among patients with CDI compared to the control group. We also observed that the Elongation Index (EI) was decreased when shear stress values were low, between 0.3 Pa and 0.58 Pa, whereas EI was increased for shear stress in the range of 1.13-59.97 Pa. These observations were statistically significant. We report for the first time that acute infection of the gastrointestinal tract with Clostridium difficile is associated with abnormalities in rheological properties of blood, increased serum viscosity as well as increased aggregation of RBCs, which correlated with severity of inflammation. These abnormalities may be an additional mechanism causing increased incidence of VTE in CDI.

Effects of nicotine, and nicotine + vitamin E on glucose 6-phosphate dehydrogenase (G-6PD) activity in rat muscle, heart, lungs, testicle, kidney, stomach, brain and liver were investigated in vivo and in vitro on partially purified homogenates. Supplementation period was 3 weeks (n = 8 rats per group): nicotine [0.5 mg/kg/day, intraperitoneal (ip)]; nicotine + vitamin E [75 mg/kg/day, intragastric (ig)]; and control group (receiving only vehicle). The results showed that nicotine (0.5 mg/kg, ip) inhibited G-6PD activity in the lungs, testicle, kidney, stomach and brain by 12.5% (p < 0.001), 48% (p < 0.001), 20.8% (p < 0.001), 13% (p < 0.001) and 23.35% (p < 0.001) respectively, and nicotine had no effects on the muscle, heart and liver G6PD activity. Also, nicotine + vitamin E inhibited G-6PD activity in the testicle, brain, and liver by 32.5% (p < 0.001), 21.5% (p < 0.001), and 16.5% (p < 0.001) respectively, and nicotine + vitamin E activated the muscle, and stomach G-6PD activity by 36% (p < 0.05), and 20% (p < 0.001) respectively. In addition, nicotine + vitamin E did not have any effects on the heart, lungs, and kidney G-6PD activity. In addition, in vitro studies were also carried out to elucidate the effects of nicotine and vitamin E on G-6PD activity, which correlated well with in vivo experimental results in lungs, testicles, kidney, stomach, brain and liver tissues. These results show that vitamin E administration generally restores the inactivation of G-6PD activity due to nicotine administration in various rat tissues in vivo, and also in vitro.

Red blood cells (RBC) of children with terminal renal insufficiency show a reduction of the apparent 51Cr RBC half-life (16.5 +/- 5.5 days). The enzymatic activities of phosphofructokinase (PFK) and glucose 6-phosphate dehydrogenase (G6PD) in the RBC of these patients do not differ from those in health persons. The RBC of uraemic and healthy children were separated by density gradient centrifugation in dextran medium according to maturity and age. RET count, mean cellular Hb concentration (MCHC), PFK and G6PD activities were determined in the separated cell populations. MCHC increases with increasing cell density while the number of RET decreases. There is a distinct decrease in the G6PD activity of low-density cells compared to high-density cells. The extent of the decrease in enzymatic activity is about the same for healthy persons as for uraemic patients. A more rapid decrease in G6PD activity per unit of time can be assumed when the enzymatic activity is plotted against the distinctly shortened life span of the RBC of the uraemic children. There is a possible relationship between G6PD activity in old RBC and the premature destruction of these cells. PFK activity apparently does not decrease with increasing cell age.

In the present study, we investigated the role of glucose-6-phosphate dehydrogenase (G6PDH) in regulating the levels of reduced form of glutathione (GSH) to the tolerance of calli from two reed ecotypes, Phragmites communis Trin. dune reed (DR) and swamp reed (SR), in a long-term salt stress. G6PDH activity was higher in SR callus than that of DR callus under 50-150 mM NaCl treatments. In contrast, at higher NaCl concentrations (300-600 mM), G6PDH activity was lower in SR callus. A similar profile was observed in GSH contents, glutathione reductase (GR) and glutathione peroxidase (GPX) activities in both salt-stressed calli. After G6PDH activity and expression were reduced in glycerol treatments, GSH contents and GR and GPX activity decreased strongly in both calli. Simultaneously, NaCl-induced hydrogen peroxide (H2O2) accumulation was also abolished. Exogenous application of H2O2 increased G6PDH, GR, and GPX activities and GSH contents in the control conditions and glycerol treatment. Diphenylene iodonium (DPI), a plasma membrane (PM) NADPH oxidase inhibitor, which counteracted NaCl-induced H(2)O(2) accumulation, decreased these enzymes activities and GSH contents. Furthermore, exogenous application of H2O2 abolished the N-acetyl-L: -cysteine (NAC)-induced decrease in G6PDH activity, and DPI suppressed the effect of buthionine sulfoximine (BSO) on induction of G6PDH activity. Western-blot analyses showed that G6PDH expression was stimulated by NaCl and H2O2, and blocked by DPI in DR callus. Taken together, G6PDH activity involved in GSH maintenance and H2O2 accumulation under salt stress. And H2O2 regulated G6PDH, GR, and GPX activities to maintain GSH levels. In the process, G6PDH plays a central role.

Diabetes mellitus is a metabolic disease belongs to a group of disparate diseases clinically and genetically characterized by increased blood sugar (hyperglycemia) as a result of defect in insulin metabolism. Glucose-6-Phosphate Dehydrogenase (G6PD) (Oxidoreductase, EC 1.1.1.1-49) is one of the most important enzymes of the metabolite, the main enzyme and the key to the Pentose phosphate path way. Unsuitable control of blood glucose decreases G6PD activity and increases diabetes mellitus complications. the This study evaluated effect of Mediterranean mutation which causes decrease G6PD activity on diabetes patients and evaluated the difference of G6PD activity among diabetic and non-diabetic patients, and the impact of hyperglycemia on the G6PD activity and different in G6PD activity in six and age and relation between Calcium and Magnesium with G6PD activity and Mediterranean mutation and found correlative coefficient(r) between G6PD activity in Patient and Blood sugar, Calcium, Magnesium and G6PD activity in healthy people. Asixteen diabetic and non-diabetic subjects were selected from patients 8 to 60 years old. Demographic data including gender, age, height, weight, duration of diabetes mellitus, type and duration of treatment, medical history (especially fauvism) were recorded. Blood pressure and body mass index were also measured. One blood sample was taken from each subject and 5 elements including G6PD presence and activity, fasting plasma glucose, plasma Calcium, Magnesium and DNA was extraction from whole blood and then amplified by polymerase chain reaction (PCR) and later subjected to digestion by restriction enzyme <i>MboII</i> to create restriction fragment length polymorphism (RFLP) to enable the detection of mutation that caused G6PD deficiency namely Mediterranean (Med). G6PD activity was significantly higher in non-diabetic subjects (P<0.05). Within diabetics, G6PD mean activity was significantly higher in non-group (P<0.05) and in subjects with BMI < 25 (P<0.05). G6PD mean activity was significantly higher in non-diabetics than (P<0.01) and Ca, Mg diabetics patients (P<0.05) the Med-G6PD mutation in diabetes patient was more in non-diabetes patient, (47) diabetes patient have Med-G6PD (78.3%) and (15) non diabetes have the mutation (15%) and the G6PD activity was significantly higher with Med-G6PD mutation in in diabetes patient (P<0.05) and non-significantly higher with non-diabetes patient.<i> The </i>Med-G6PD mutation can be used as molecular marker to diagnosis diabetes, Diabetic hyperglycemia may lead to serious complications and decrease G6PD activity. This issue itself aggravates diabetic injury due to inappropriate anti oxidation process. Simultaneous dyslipidemia and obesity may intensify the effect of hyperglycemia and oxidative stress.

Is it Accurate to Separate Glucose-6-Phosphate Dehydrogenase Activity in Neonatal Hyperbilirubinemia as Deficient and Normal?

Synergistic activation of glucose-6-phosphate dehydrogenase and NAD(P)H oxidase by Src kinase elevates superoxide in type 2 diabetic, Zucker fa/fa, rat liver

Glucose 6-phosphate dehydrogenase (G6PDH) activity was examined in the developing embryonic chick in brachial and lumbar spinal cord and pectoral and leg muscle. Enzyme activity was generally highest at the earliest stage examined, embryonic day 5. The developmental profiles for G6PDH activity in the two muscles were similar: a sharp initial decrease occurred between days 5 and 9, with relatively low levels present by day 18; peaks of G6PDH activity at days 12 and 16 were more prominent in leg muscle. Similar levels of G6PDH were also detected in spinal cord with the developmental profile in the brachial spinal cord resembling that seen in muscle. In lumbar spinal cord, initial G6PDH activity was lower than in brachial spinal cord; the developmental profile, however, resembled that seen in the brachial spinal cord, with an initial drop in enzyme activity seen between days 5 and 7. Neural regulation of G6PDH activity in mature muscle is believed to repress enzyme synthesis. The drop in G6PDH activity observed in embryonic spinal cord and muscle between days 5 and 9 coincides with the initiation of functional neuromuscular contacts. Hence, the normal regulation of G6PDH during embryonic development may involve the repression of G6PDH in spinal cord neurons and muscle, possibly effected by their interaction.

Exposure to chrysotile asbestos causes carbonylation of glucose 6-phosphate dehydrogenase through a reaction with lipid peroxidation products in human lung epithelial cells

Mechanisms of Primaquine Induced Hemolysis in a Novel Humanized Murine Model of Mediterranean G6PD Deficiency

Fetal distress represents a pathophysiological condition in which oxygen is not available to the fetus in sufficient quantities. In cases of glucose 6-phosphate dehydrogenase (G6PD) deficiency, under conditions of oxidative stress, the residual G6PD and complimentary antioxidant mechanisms may become insufficient to neutralize the large amounts of ROS and to prevent severe hemolysis. Alteration in the oxidant-antioxidant profile is also known to occur in neonatal jaundice. The study group included 22 neonates presented with fetal distress during labor and 24 neonates with no evidence of fetal distress (control group). Umbilical cord blood samples were taken immediately after delivery, and the following blood tests were carried out after birth and at discharge from the hospital: erythrocyte count, total bilirubin, G6PD activity, and parameters presenting oxidative status [thiobarbituric acid reactive substances (TBARS), NO, O2 (-), H2O2, SOD, CAT, O2 (-)/SOD, and H2O2/CAT]. There were no significant differences in TBARS and NO values among neonates with or without fetal distress. However, the values of O2 (-), H2O2, SOD, O2 (-)/SOD, and H2O2/CAT among neonates born after fetal distress were significantly higher than in neonates without fetal distress (p<0.01). In neonates with fetal distress, the total number of RBCs at delivery was significantly lower, accompanied with higher bilirubin content. Also neonates with fetal distress had lower activity of G6PD and lower CAT activity. Higher values of oxidative stress parameters in newborns delivered after fetal distress do not indicate strictly what occurred first-oxidative stress or basic lower G6PD activity.

Dietary Fatty Acids and the Control of Glucose-6-Phosphate Dehydrogenase and Malic Enzyme in the Starved-Refed Rat

Index of Suspicion