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Sample records for elevated glucose concentrations

  1. Falsely Elevated Glucose Concentrations in Peritoneal Dialysis Patients Using Icodextrin.

    PubMed

    Dogan, Kübra; Kayalp, Damla; Ceylan, Gözde; Azak, Alper; Senes, Mehmet; Duranay, Murat; Yucel, Dogan

    2016-09-01

    Peritoneal dialysis (PD) is used as an alternative to hemodialysis in end-stage renal disease (ESRD). Icodextrin has been used as a hyperosmotic agent in PD. The aim of the study was to assess two different point-of-care testing (POCT) glucose strips, affected and not affected by icodextrin, with serum glucose concentrations of the patients using and not using icodextrin. Fifty-two chronic ambulatory peritoneal dialysis (CAPD) patients using icodextrin (Extraneal®) and 20 CAPD patients using another hyperosmotic fluid (Dianeal®) were included in the study. Duplicate capillary and serum glucose concentrations were measured with two different POCT glucose strips and central laboratory hexokinase method. Assay principles of glucose strips were based on glucose dehydrogenase-pyrroloquinoline quinone (GDH-PQQ) and a mutant variant of GDH (Mut Q-GDH). The results of both strips were compared with those of hexokinase method. Regression equations between POCT and hexokinase methods in icodextrin group were y = 2.55x + 1.12 mmol/l and y = 1.057x + 0.16 mmol/l for the GDH-PQQ and Mut Q-GDH methods, respectively. The mean difference between the results of hexokinase and those of GDH-PQQ and Mut Q-GDH in icodextrin group was 3.41 ± 1.56 and 0.72 ± 0.64 mmol/l, respectively. However, the mean differences were found much lower in the control group; 0.64 mmol/l for GDH-PQQ and 0.52 mmol/l for Mut Q-GDH. Compared to GDH-PQQ, glucose strips of Mut Q-GDH correlated better with hexokinase method in PD patients using icodextrin. © 2015 Wiley Periodicals, Inc.

  2. Elevated glucose concentration changes the content and cellular localization of AMPA receptors in the retina but not in the hippocampus.

    PubMed

    Castilho, A F; Liberal, J T; Baptista, F I; Gaspar, J M; Carvalho, A L; Ambrósio, A F

    2012-09-06

    Diabetic retinopathy and diabetic encephalopathy are two common complications of diabetes mellitus. The impairment of glutamatergic neurotransmission in the retina and hippocampus has been suggested to be involved in the pathogenesis of these diabetic complications. In this study, we investigated the effect of elevated glucose concentration and diabetes on the protein content and surface expression of AMPA receptor subunits in the rat retina and hippocampus. We have used two models, cultured retinal and hippocampal cells exposed to elevated glucose concentration and an animal model of streptozotocin-induced type 1 diabetes. The immunoreactivity of GluA1, GluA2 and GluA4 was evaluated by Western blot and immunocytochemistry. The levels of these subunits at the plasma membrane were evaluated by biotinylation and purification of plasma membrane-associated proteins. Elevated glucose concentration increased the total levels of GluA2 subunit of AMPA receptors in retinal neural cells, but not of the subunits GluA1 or GluA4. However, at the plasma membrane, elevated glucose concentration induced an increase of all AMPA receptor subunits. In cultured hippocampal neurons, elevated glucose concentration did not induce significant alterations in the levels of AMPA receptor subunits. In the retinas of diabetic rats there were no persistent changes in the levels of AMPA receptor subunits comparing to aged-matched control retinas. Also, no consistent changes were detected in the levels of GluA1, GluA2 or GluA4 in the hippocampus of diabetic rats. We demonstrate that elevated glucose concentration induces early changes in AMPA receptor subunits, mainly in GluA2 subunit, in retinal neural cells. Conversely, hippocampal neurons seem to remain unaffected by elevated glucose concentration, concerning the expression of AMPA receptors, suggesting that AMPA receptors are more susceptible to the stress caused by elevated glucose concentration in retinal cells than in hippocampal neurons.

  3. Elevation of blood β-hydroxybutyrate concentration affects glucose metabolism in dairy cows before and after parturition.

    PubMed

    Zarrin, M; Grossen-Rösti, L; Bruckmaier, R M; Gross, J J

    2017-03-01

    Recent studies in mid- and late-lactation dairy cows showed that β-hydroxybutyrate (BHB) infusion had a considerable effect on glucose metabolism and immune response during intramammary lipopolysaccharide challenge. The objective of the present study was to infuse BHB during the dry period and after parturition to investigate the effects of elevated plasma BHB concentrations on metabolism and endocrine changes in transition dairy cows. The hypothesis tested was that regulation of glucose metabolism would change at different physiological stages and an additional elevation of BHB concentration would alter glucose concentration. Multiparous Holstein cows in wk -2 (antepartum, a.p.; n = 6) and wk +2 (postpartum, p.p.; n = 8) relative to calving were infused (4 h from 0800 to 1200 h) with a BHB solution to increase plasma BHB concentration to 1.5 to 2.0 mmol/L (HyperB). The same period the next day without any infusion was considered the control period (CON). Blood samples were taken 1 h before the start of infusion as reference samples and every 30 min during the following 6 h (4 h of infusion and 2 h after infusion) in the HyperB and CON periods, and analyzed for glucose, BHB, insulin, and glucagon concentrations. During the steady state period (the latter 2 h of the 4-h infusion), plasma BHB concentration reached 1.87 ± 0.05 mmol/L (a.p.) and 1.93 ± 0.05 mmol/L (p.p.) in HyperB compared with 0.55 ± 0.06 mmol/L (a.p.) and 0.64 ± 0.04 mmol/L (p.p.) in CON, respectively. The 4-h average BHB infusion rate was 12.4 ± 1.0 and 13.3 ± 0.9 μmol/kg of BW per minute in wk -2 and +2, respectively. Infusion of BHB caused a decrease of plasma glucose concentrations relative to preinfusion levels both before and after parturition, although basal glucose concentrations were different before and after calving. Infusion of BHB increased plasma insulin concentrations a.p. but not p.p., despite a higher basal insulin concentration before than after parturition. These findings

  4. Elevated glucose concentration and natriuretic peptides receptor response on vascular smooth muscle of spontaneously hypertensive rats.

    PubMed

    Yasunari, K; Kohno, M; Kano, H; Hanehira, T; Minami, M; Ikeda, M; Horio, T; Yokokawa, K; Takeda, T

    1995-12-01

    1. Hyperglycaemia is believed to be a major cause of diabetic vascular complications such as accelerated atherosclerosis. In order to elucidate the effect of hyperglycaemia on vascular response in spontaneously hypertensive rats (SHR), the natriuretic peptides receptor responses to vascular smooth muscle cells (VSMC) which are thought to suppress atherosclerosis were studied under high glucose (HG:22.2 mmol/L) conditions. 2. The total number of cells in SHR is higher and natriuretic peptides receptor response is smaller than that of cells in the Wistar-Kyoto (WKY) rat. Membrane bound protein kinase C (PKC) activity in HG or SHR is higher compared to that of cells in normal glucose (NG:5.6 mmol/L) or WKY. Cells cultured in HG for at least 2 passages had higher total cell number and receptor mediated cGMP formation were suppressed compared to cells cultured in NG both in SHR and WKY. Specific PKC inhibitor PKC (19-36) 1 mu mol/L prevented HG induced suppression of natriuretic peptides response. 3. These results show that hyperglycaemia may be linked to suppressed natriuretic peptides receptor response which is caused by increased PKC activity both in WKY and SHR. This suppressed response may cause the accelerated atherosclerosis by hyperglycaemia.

  5. Small elevations of glucose concentration redirect and amplify the synthesis of guanosine 5'-triphosphate in rat islets.

    PubMed Central

    Metz, S A; Meredith, M; Rabaglia, M E; Kowluru, A

    1993-01-01

    Recent studies suggest a permissive requirement for guanosine 5'-triphosphate (GTP) in insulin release, based on the use of GTP synthesis inhibitors (such as myocophenolic acid) acting at inosine monophosphate (IMP) dehydrogenase; herein, we examine the glucose dependency of GTP synthesis. Mycophenolic acid inhibited insulin secretion equally well after islet culture at 7.8 or 11.1 mM glucose (51% inhibition) but its effect was dramatically attenuated when provided at < or = 6.4 mM glucose (13% inhibition; P < 0.001). These observations were explicable by a stimulation of islet GTP synthesis derived from IMP since, at high glucose: (a) total GTP content was augmented; (b) a greater decrement in GTP (1.75 vs. 1.05 pmol/islet) was induced by mycophenolic acid; and (c) a smaller "pool" of residual GTP persisted after drug treatment. Glucose also accelerated GTP synthesis from exogenous guanine ("salvage" pathway) and increased content of a pyrimidine, uridine 5'-triphosphate (UTP), suggesting that glucose augments production of a common regulatory intermediate (probably 5-phosphoribosyl-1-pyrophosphate). Pathway-specific radiolabeling studies confirmed that glucose tripled both salvage and de novo synthesis of nucleotides. We conclude that steep changes in the biosynthesis of cytosolic pools of GTP occur at modest changes in glucose concentrations, a finding which may have relevance to the adaptive (patho) physiologic responses of islets to changes in ambient glucose levels. PMID:8349822

  6. Possible involvement of phospholipase D and protein kinase C in vascular growth induced by elevated glucose concentration.

    PubMed

    Yasunari, K; Kohno, M; Kano, H; Yokokawa, K; Horio, T; Yoshikawa, J

    1996-08-01

    Hyperglycemia is believed to be a major cause of diabetic vascular complications. To elucidate the effect of hyperglycemia on vascular response, we studied hyperproliferation, hypertrophy, and the natriuretic peptide response of vascular smooth muscle cells under high-glucose conditions. We observed that cells cultured in high glucose (22.2 mmol/L) showed hyper-proliferation and hypertrophy and that natriuretic peptide receptor responses were suppressed compared with cells cultured in normal glucose (5.6 mmol/L). We also examined phospholipase D and protein kinase C activities and found that in high-glucose conditions such activities are higher than in cells cultured in normal glucose. The activation of phospholipase D was not prevented by coincubation with 1 mumol/L protein kinase C(19-36), a specific protein kinase C inhibitor, but the activation of protein kinase C was. Protein kinase C(19-36) also markedly attenuated vascular hyperproliferation and hypertrophy as well as glucose-induced suppression of natriuretic peptide receptor response. These results show that hyperglycemia may be linked to vascular hyperproliferation, hypertrophy, and a suppressed natriuretic peptide receptor response, which are caused by increased phospholipase D and protein kinase C activities.

  7. Serum Soluble Transferrin Receptor Concentrations Are Elevated in Congolese Children with Glucose-6-Phosphate Dehydrogenase Variants, but Not Sickle Cell Variants or α-Thalassemia.

    PubMed

    Barker, Mikaela K; Henderson, Amanda M; Naguib, Karimah; Vercauteren, Suzanne M; Devlin, Angela M; Albert, Arianne Y; Bahizire, Esto; Tugirimana, Pierrot L; Akilimali, Pierre Z; Boy, Erick; Green, Tim J; Karakochuk, Crystal D

    2017-09-01

    Background: Anemia is common in Congolese children, and inherited blood disorders may be a contributing cause. The presence of sickle cell variants, X-linked glucose-6-phosphate dehydrogenase (G6PD) deficiency and α-thalassemia, has been previously reported. G6PD A- deficiency is characterized by the co-inheritance of G6PD 376 and 202 variants and is common in sub-Saharan Africa.Objective: We aimed to measure the associations between inherited blood disorders and hemoglobin, ferritin, and soluble transferrin receptor (sTfR) concentrations in Congolese children.Methods: Venous blood was collected from 744 children aged 6-59 mo from 2 provinces. We measured biomarkers of nutritional and inflammation status and malaria. Pyrosequencing was used to detect sickle cell variants. Polymerase chain reaction was used to detect G6PD variants and α-thalassemia deletions.Results: Overall, 11% of children had a sickle cell variant, 19% of boys were G6PD A- hemizygotes, 12% and 10% of girls were G6PD A- hetero- or homozygotes, respectively, and 12% of children had α-thalassemia. Multivariable linear regression models (adjusted for age, province, altitude, malaria, and biomarkers of nutritional and inflammation status) showed that G6PD A- hemizygous boys and G6PD 376 homozygous girls had higher sTfR concentrations [geometric mean ratios (95% CIs): 1.20 (1.03, 1.39) and 1.25 (1.02, 1.53), respectively] than children with no G6PD variants. Hemoglobin and ferritin concentrations were not independently associated with any of the inherited blood disorder genotypes.Conclusions: We found that 2 G6PD variant genotypes were associated with elevated sTfR concentrations, which limits the accuracy of sTfR as a biomarker of iron status in this population. © 2017 American Society for Nutrition.

  8. Glucose elevates ornithine decarboxylase expression in Vero cells.

    PubMed

    Lundgren, D W; Prokay, S L

    1988-12-01

    The addition of Earle's balanced salt solution (EBSS) of amino acids that are transported by a Na+-dependent cotransport system was not required by Vero cells for ornithine decarboxylase (ODC:EC 4.1.1.17) amplification. Vero cell ODC activity was elevated tenfold above basal levels when confluent cells were incubated for 5 hr in EBSS alone. ODC activity increased as a function of the incubation time in EBSS and was not elevated above basal enzyme levels when cells were incubated in EBSS minus glucose. ODC expression increased as a function of the glucose concentration in EBSS, with 20 mM glucose producing a 90-fold increase in ODC activity. ODC expression is more responsive to glucose in high-density quiescent cultures than in low-density growing cultures. Enhanced ODC expression by glucose depended on Na+ and K+ concentrations. The specific activity of ODC was also elevated above basal levels when mannose or fructose replaced glucose in EBSS. The addition of alanine or asparagine to EBSS enhanced ODC activity above levels obtained with EBSS containing standard (5.5 mM) glucose concentrations. In the absence of glucose, alanine was more effective than asparagine in enhancing ODC expression. These results suggest that the transport of amino acids is not an absolute requirement for Vero cell ODC expression and that ODC expression is linked to changes in cellular energetics and/or ion fluxes.

  9. Alterations of intraembryonic metabolites in preimplantation mouse embryos exposed to elevated concentrations of glucose: a metabolic explanation for the developmental retardation seen in preimplantation embryos from diabetic animals.

    PubMed

    Moley, K H; Chi, M M; Manchester, J K; McDougal, D B; Lowry, O H

    1996-06-01

    Preimplantation mouse embryos exposed to hyperglycemia, whether in vivo or in vitro, experience delayed development from the 2-cell to blastocyst stage. By comparing metabolites from embryos exposed to high vs. normal glucose conditions, a metabolic explanation for the delayed growth pattern was sought. Fertilized 1-cell embryos obtained from superovulated B5 x CBA F1 mice were cultured for 96 h in medium containing 2.8 mM glucose (C) or in medium with added glucose to give 10 mM, 30 mM, or 52 mM glucose (HG). After incubation, each embryo was quick-frozen and freeze-dried. Metabolites were assayed by the ultramicrofluorometric technique and enzymatic cycling to obtain measurable levels in single embryos. Embryos cultured in HG exhibited 7-fold higher intracellular glucose levels than those cultured in C (C: 2.25 +/- 0.6 vs. HG: 16.61 +/- 2.4 mmol/kg wet weight; p < 0.001; C, n = 9; HG, n = 16). This accumulation of glucose was dose-related and stage-dependent. Citrate (C: 1.07 +/- 0.14 vs. HG: 1.98 +/- 0.12; p < 0.001), sorbitol (C: 0.41 +/- 0.06 vs. HG: 0.57 +/- 0.03; p < 0.01), malate (C: 0.81 +/- 0.13 vs. HG: 1.72 +/- 0.17; p < 0.001), and fructose (C: 2.1 +/- 0.3 vs. HG: 5.3 +/- 0.6; p < 0.001) were all significantly higher in HG. Also, these metabolites were highest in the most delayed embryos. Glycogen and 6-phosphogluconate levels were not significantly different. In conclusion, intraembryonic levels of glucose, and polyol pathway and Krebs cycle metabolites are elevated and correspond to the degree of developmental delay. These findings suggest that a metabolic abnormality may be responsible for retarded development experienced by embryos exposed to high glucose.

  10. Addition of Orange Pomace to Orange Juice Attenuates the Increases in Peak Glucose and Insulin Concentrations after Sequential Meal Ingestion in Men with Elevated Cardiometabolic Risk.

    PubMed

    Dong, Honglin; Rendeiro, Catarina; Kristek, Angelika; Sargent, Laura J; Saunders, Caroline; Harkness, Laura; Rowland, Ian; Jackson, Kim G; Spencer, Jeremy Pe; Lovegrove, Julie A

    2016-06-01

    Prospective cohort studies show that higher dietary fiber intake is associated with reduced cardiovascular disease risk, yet the impact on postprandial glucose and insulin responses is unclear. This study aims to evaluate the effects of orange beverages with differing fiber concentrations on postprandial glycemic responses (secondary outcome measure) after a sequential breakfast and lunch challenge in men with increased cardiometabolic risk. Thirty-six men (aged 30-65 y; body mass index 25-30 kg/m(2): fasting triacylglycerol or total cholesterol concentrations: 0.8-2.2 or 6.0-8.0 mmol/L, respectively) were provided with a high-fat mixed breakfast and were randomly assigned to consume 240 mL Tropicana (PepsiCo, Inc.) pure premium orange juice without pulp (OJ), OJ with 5.5 g added orange pomace fiber (OPF), juice made from lightly blended whole orange, or an isocaloric sugar-matched control (Control) on 4 occasions separated by 2 wk. A medium-fat mixed lunch was provided at 330 min. Blood samples were collected before breakfast and on 11 subsequent occasions for 420 min (3 time points postlunch) to determine postprandial glucose, insulin, lipid, and inflammatory biomarker responses. Repeated-measures ANOVA was used for data analysis. OPF significantly (P < 0.05) reduced the maximal change in glucose concentrations (1.9 ± 0.21 mmol/L) reached after breakfast compared with other treatments (2.3-2.4 mmol/L) and after lunch (3.0 ± 0.05 mmol/L) compared with OJ (3.6 ± 0.05 mmol/L). The maximal change in insulin concentration (313 ± 25 pmol/L) was also lower compared with Control (387 ± 30 pmol/L) and OJ (418 ± 39 pmol/L) after breakfast. OPF significantly delayed the time to reach the peak glucose concentration compared with Control and OJ, and of insulin compared with Control after breakfast. OPF consumed with breakfast may lower postprandial glycemic and insulinemic responses to typical meal ingestion in men with increased cardiometabolic risk. This trial is

  11. Modeling of relationship between glucose concentration in blood and glucose concentration in interstitial fluid

    NASA Astrophysics Data System (ADS)

    Shi, Ting; Li, Dachao; Ji, Yongjie; Li, Guoqing; Xu, Kexin

    2012-03-01

    In recent years, using the detection of interstitial fluid glucose concentration to realize the real-time continuous monitoring of blood glucose concentration gets more and more attention, because for one person, the relationship between blood glucose concentration and interstitial fluid glucose concentration satisfies specific rules. However, the glucose concentration in interstitial fluid is not entirely equal to the glucose concentration in blood and has a physiological lag because of the physiological difference of cells in blood and interstitial fluid. Because the clinical diagnostic criteria of diabetes are still blood glucose concentration, the evaluation model of the physiological lag parameter between the glucose concentration in blood and the glucose concentration in interstitial fluid should be established. The physiological difference in glucose molecules uptake, utilization, and elimination by cells in blood and interstitial fluid and the diffusion velocity of glucose molecule from blood to interstitial fluid will be induced to the mass transfer model to express the physiological lag parameter. Based on the continuous monitoring of glucose concentration in interstitial fluid, the project had studied the mass transfer model to establish the evaluation model of the physiological lag parameter between the glucose concentration in blood and the glucose concentration in interstitial fluid. We have preliminary achieved to evaluate the physiological lag parameter exactly and predict the glucose concentration in blood through the glucose concentration in interstitial fluid accurately.

  12. Mechanical stress and glucose concentration modulate glucose transport in cultured rat podocytes.

    PubMed

    Lewko, Barbara; Bryl, Ewa; Witkowski, Jacek M; Latawiec, Elzbieta; Angielski, Stefan; Stepinski, Jan

    2005-02-01

    Recent studies show that mechanical stress modifies both morphology and protein expression in podocytes. Ambient glucose is another factor modulating protein synthesis in these cells. In diabetes, podocytes experience elevated glucose concentrations as well as mechanical strain generated by high intracapillary pressures. Both these factors are responsible for podocyte injury, leading to impairment of kidney glomerular function. In the present study, we examined the effects of glucose concentration and mechanical stress on glucose uptake in podocytes. Following a 24 h pre-incubation in low (2.5 mM, LG), normal (5.6 mM, NG) or high (30 mM, HG) glucose media, cultured rat podocytes were exposed to 4 h mechanical stress. We used the labelled glucose analogue, [3H]2-deoxy-D-glucose, to measure glucose uptake. The distribution of facilitative glucose transporters GLUT2 and GLUT4 was assessed by flow cytometry. In the control (static) cells, glucose uptake was similar in the three glucose groups. In mechanically stressed podocytes, glucose uptake increased 2-fold in the LG and NG groups but increased 3-fold in the HG group. In the NG cells, mechanical load increased the membrane expression of GLUT2 and reduced the membrane-bound GLUT4. In stretched HG cells, the membrane expression of both GLUT2 and GLUT4 was decreased. High glucose decreased the plasma membrane GLUT2 content in the stretched cells, whereas both static and stretched podocytes showed an elevation in GLUT4. Mechanical stress potentiated glucose uptake in podocytes and this effect was enhanced by high ambient glucose. The decreased expression of GLUT2 and GLUT4 on the surface of stretched cells suggests that the activity of other glucose transporters may be regulated by mechanical stress in podocytes.

  13. Nonlinear optical measurements of glucose concentration

    NASA Astrophysics Data System (ADS)

    Yakovlev, V. V.

    2008-02-01

    Diabetes mellitus is a metabolic disease that currently affects about 7% of the US population, or roughly about 20 million people. Effectively controlling diabetes requires regular measurements of the blood sugar levels to ensure the one time insulin injection when the concentration of glucose reaches a critical level. In this report, nonlinear Raman microspectroscopy is demonstrated to be a promising new way of continuous and noninvasive way of measuring the glucose concentration.

  14. Postprandial Glucose as a Risk Factor for Elevated Intraocular Pressure

    PubMed Central

    Wu, Chen-Jung; Fang, Wen-Hui; Kao, Tung-Wei; Chen, Ying-Jen; Liaw, Fang-Yih; Chang, Yaw-Wen; Wang, Gia-Chi; Peng, Tao-Chun; Chen, Wei-Liang

    2016-01-01

    The aim of this study was to investigate the association between postprandial glucose and intraocular pressure in a relatively healthy population. We examined 1,439 adults getting a health check-up in a health promotion center at Tri-Service General Hospital (TSGH) in Taiwan between 2012 and 2013. All participants underwent examinations to measure metabolic variables and intraocular pressure. Multiple linear regression analyses were performed to assess the relationship between postprandial glucose and intraocular pressure. The levels of postprandial glucose were divided into quartiles with subjects in the lowest quartile being regarded as the reference group to perform quartile-based analysis. Covariate adjustment was designed for three models for further analysis. Subjects with higher quartiles of postprandial glucose level had a higher systolic blood pressure, a greater waist circumference and an elevated fasting glucose level (all p < 0.001). The β coefficient with adjusted covariates showed a significant positive association between postprandial glucose and intraocular pressure. The trends of intraocular pressure across increasing quartiles of postprandial glucose were statistically significant (all p for trend < 0.001). Thus, higher levels of postprandial glucose positively correlated with elevated intraocular pressure. PMID:27977733

  15. Adrenergic blockade does not abolish elevated glucose turnover during bacterial infection

    SciTech Connect

    Hargrove, D.M.; Bagby, G.J.; Lang, C.H.; Spitzer, J.J. )

    1988-01-01

    Infusions of adrenergic antagonists were used to investigate the role of catecholamines in infection-induced elevations of glucose kinetics. Infection was produced in conscious catheterized rats by repeated subcutaneous injections of live Escherichia coli over 24 h. Glucose kinetics were measured by the constant intravenous infusion of (6-{sup 3}H)- and (U-{sup 14}C)glucose. Compared with noninfected rats, infected animals were hyperthermic and showed increased rates of glucose appearance, clearance, and recycling as well as mild hyperlacticacidemia. Plasma catecholamine concentrations were increased by 50-70% in the infected rats, but there were no differences in plasma glucagon, corticosterone, and insulin levels. Adrenergic blockade was produced by primed constant infusion of both propranolol ({beta}-blocker) and phentolamine ({alpha}-blocker). A 2-h administration of adrenergic antagonists did not attenuate the elevated glucose kinetics or plasma lactate concentration in the infected rats, although it abolished the hyperthermia. In a second experiment, animals were infused with propranolol and phentolamine beginning 1 h before the first injection of E. coli and throughout the course of infection. Continuous adrenergic blockade failed to attenuate infection-induced elevations in glucose kinetics and plasma lactate. These results indicate that the adrenergic system does not mediate the elevated glucose metabolism observed in this mild model of infection.

  16. Red cell distribution width is associated with hemoglobin A1C elevation, but not glucose elevation.

    PubMed

    Bao, Xue; Wan, Min; Gu, Yeqing; Song, Yanqi; Zhang, Qing; Liu, Li; Meng, Ge; Wu, Hongmei; Xia, Yang; Shi, HongBin; Su, Qian; Fang, Liyun; Yang, Huijun; Yu, Fei; Sun, Shaomei; Wang, Xing; Zhou, Ming; Jia, Qiyu; Song, Kun; Wang, Guolin; Yu, Ming; Niu, Kaijun

    2017-10-01

    To investigate the association between red cell distribution width (RDW) and elevation of glucose/glycated hemoglobin (HbA1c). An analysis was conducted using data from a prospective cohort study of adults. People without prediabetes or diabetes (n=7,795) were followed for a mean of 2.90years (range: 1-7years, 95% confidence interval: 2.86-2.94years). Glucose elevation is defined as fasting glucose levels exceeding 5.6mmol/l, or 2-hour glucose values in the oral glucose tolerance test exceeding 7.8mmol/l. HbA1c elevation is defined as a HbA1c value exceeding a normal limit of 39mmol/mol (5.7%). Adjusted Cox proportional hazards regression models were used to assess the association between RDW quartiles and elevation of HbA1c/glucose. The multiple-adjusted hazard ratios (95% confidence interval) of HbA1c elevation for increased quartiles of RDW were 1.00 (reference), 1.08 (0.89, 1.30), 1.28 (1.07, 1.54), and 1.54 (1.29, 1.85) (P for trend<0.0001). However, no significant association was observed between RDW and blood glucose (fasting and postprandial). Elevated RDW is independently related to future HbA1c elevation, but not to glucose elevation. This suggests that RDW may associate with HbA1c through a non-glycemic way, which should be taken into consideration when using HbA1c as a diagnostic criterion of prediabetes or diabetes. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Plasma Efavirenz Concentrations Are Associated With Lipid and Glucose Concentrations

    PubMed Central

    Sinxadi, Phumla Zuleika; McIlleron, Helen Margaret; Dave, Joel Alex; Smith, Peter John; Levitt, Naomi Sharlene; Haas, David William; Maartens, Gary

    2016-01-01

    Abstract Efavirenz-based antiretroviral therapy (ART) has been associated with dyslipidemia and dysglycemia, risk factors for cardiovascular disease. However, the pathogenesis is not well understood. We characterized relationships between plasma efavirenz concentrations and lipid and glucose concentrations in HIV-infected South Africans. Participants on efavirenz-based ART were enrolled into a cross-sectional study. The oral glucose tolerance test was performed after an overnight fast, and plasma drawn for mid-dosing interval efavirenz, fasting total cholesterol, low-density lipoprotein (LDL) and high-density lipoprotein (HDL) cholesterol, and triglycerides concentrations. Among 106 participants (77 women), median age was 38 years, median CD4 + T-cell count was 322 cells/μL, median duration on ART was 18 months, and median (interquartile range) efavirenz concentration was 2.23 (1.66 to 4.10) μg/mL. On multivariable analyses (adjusting for age, sex, body mass index, and ART duration) doubling of efavirenz concentrations resulted in mean changes in mmol/L (95%CI) of: total cholesterol (0.40 [0.22 to 0.59]), LDL cholesterol (0.19 [0.04 to 0.30]), HDL cholesterol (0.14 [0.07 to 0.20]), triglycerides (0.17 [0.03 to 0.33]), fasting glucose (0.18 [0.03 to 0.33]), and 2-h glucose concentrations (0.33 [0.08 to 0.60]). Among 57 participants with CYP2B6 genotype data, associations between slow metabolizer genotypes and metabolic profiles were generally consistent with those for measured efavirenz concentrations. Higher plasma efavirenz concentrations are associated with higher plasma lipid and glucose concentrations. This may have implications for long-term cardiovascular complications of efavirenz-based ART, particularly among populations with high prevalence of CYP2B6 slow metabolizer genotypes. PMID:26765416

  18. Antiproliferative effect of elevated glucose in human microvascular endothelial cells

    NASA Technical Reports Server (NTRS)

    Kamal, K.; Du, W.; Mills, I.; Sumpio, B. E.

    1998-01-01

    Diabetic microangiopathy has been implicated as a fundamental feature of the pathological complications of diabetes including retinopathy, neuropathy, and diabetic foot ulceration. However, previous studies devoted to examining the deleterious effects of elevated glucose on the endothelium have been performed largely in primary cultured cells of macrovessel origin. Difficulty in the harvesting and maintenance of microvascular endothelial cells in culture have hindered the study of this relevant population. Therefore, the objective of this study was to characterize the effect of elevated glucose on the proliferation and involved signaling pathways of an immortalized human dermal microvascular endothelial cell line (HMEC-1) that possess similar characteristics to their in vivo counterparts. Human dermal microvascular endothelial cells (HMEC-1) were grown in the presence of normal (5 mM) or high D-glucose (20 mM) for 14 days. The proliferative response of HMEC-1 was compared under these conditions as well as the cAMP and PKC pathways by in vitro assays. Elevated glucose significantly inhibited (P < 0.05) HMEC-1 proliferation after 7, 10, and 14 days. This effect was not mimicked by 20 mM mannitol. The antiproliferative effect was more pronounced with longer exposure (1-14 days) to elevated glucose and was irreversible 4 days after a 10-day exposure. The antiproliferative effect was partially reversed in the presence of a PKA inhibitor, Rp-cAMP (10-50 microM), and/or a PKC inhibitor, Calphostin C (10 nM). HMEC-1 exposed to elevated glucose (20 mM) for 14 days caused an increase in cyclic AMP accumulation, PKA, and PKC activity but was not associated with the activation of downstream events such as CRE and AP-1 binding activity. These data support the hypothesis that HMEC-1 is a suitable model to study the deleterious effects of elevated glucose on microvascular endothelial cells. Continued studies with HMEC-1 may prove advantageous in delineation of the molecular

  19. Antiproliferative effect of elevated glucose in human microvascular endothelial cells

    NASA Technical Reports Server (NTRS)

    Kamal, K.; Du, W.; Mills, I.; Sumpio, B. E.

    1998-01-01

    Diabetic microangiopathy has been implicated as a fundamental feature of the pathological complications of diabetes including retinopathy, neuropathy, and diabetic foot ulceration. However, previous studies devoted to examining the deleterious effects of elevated glucose on the endothelium have been performed largely in primary cultured cells of macrovessel origin. Difficulty in the harvesting and maintenance of microvascular endothelial cells in culture have hindered the study of this relevant population. Therefore, the objective of this study was to characterize the effect of elevated glucose on the proliferation and involved signaling pathways of an immortalized human dermal microvascular endothelial cell line (HMEC-1) that possess similar characteristics to their in vivo counterparts. Human dermal microvascular endothelial cells (HMEC-1) were grown in the presence of normal (5 mM) or high D-glucose (20 mM) for 14 days. The proliferative response of HMEC-1 was compared under these conditions as well as the cAMP and PKC pathways by in vitro assays. Elevated glucose significantly inhibited (P < 0.05) HMEC-1 proliferation after 7, 10, and 14 days. This effect was not mimicked by 20 mM mannitol. The antiproliferative effect was more pronounced with longer exposure (1-14 days) to elevated glucose and was irreversible 4 days after a 10-day exposure. The antiproliferative effect was partially reversed in the presence of a PKA inhibitor, Rp-cAMP (10-50 microM), and/or a PKC inhibitor, Calphostin C (10 nM). HMEC-1 exposed to elevated glucose (20 mM) for 14 days caused an increase in cyclic AMP accumulation, PKA, and PKC activity but was not associated with the activation of downstream events such as CRE and AP-1 binding activity. These data support the hypothesis that HMEC-1 is a suitable model to study the deleterious effects of elevated glucose on microvascular endothelial cells. Continued studies with HMEC-1 may prove advantageous in delineation of the molecular

  20. Effect of levofloxacin on serum glucose concentration in rats.

    PubMed

    Ishiwata, Yasuyoshi; Itoga, Yoshie; Yasuhara, Masato

    2006-12-03

    To clarify the mechanism of fluoroquinolone-induced abnormalities in blood glucose, the effect of levofloxacin on serum glucose concentration was investigated in rats. Rats received an intravenous injection of levofloxacin and their arterial blood was sampled periodically. The serum glucose concentration decreased after an injection of 100 mg/kg of levofloxacin, while it increased at levofloxacin 300 mg/kg. The serum immunoreactive insulin concentration increased as the dose of levofloxacin increased. The serum epinephrine concentration was rapidly elevated by levofloxacin at 300 mg/kg. The serum histamine concentration increased after injections of levofloxacin, 200 and 300 mg/kg. Diphenhydramine (1 mg/kg) antagonized the hyperglycemia induced by 300 mg/kg of levofloxacin. In an in vitro study, the release of epinephrine from the adrenal medulla in the presence of levofloxacin was determined. Levofloxacin (300 microg/ml) did not affect epinephrine release from the adrenal medulla. Levofloxacin can induce hypoglycemia and hyperglycemia in rats. Levofloxacin can promote histamine release, leading to an increased serum epinephrine concentration and hyperglycemia.

  1. Elevated concentrations of actinides in mono lake.

    PubMed

    Anderson, R F; Bacon, M P; Brewer, P G

    1982-04-30

    Tetravalent thorium, pentavalent protactinium, hexavalent uranium, and plutonium (oxidation state uncertain) are present in much higher concentrations in Mono Lake, a saline, alkaline lake in eastern central California, than in seawater. Low ratios of actinium to protactinium and of americium to plutonium indicate that the concentrations of trivalent actinides are not similarly enhanced. The elevated concentrations of the ordinarily very insoluble actinides are maintained in solution by natural ligands, which inhibit their chemical removal from the water column, rather than by an unusually large rate of supply.

  2. Elevated concentrations of actinides in Mono Lake

    SciTech Connect

    Anderson, R.F.; Bacon, M.P.; Brewer, P.G.

    1982-04-30

    Tetravalent thorium, pentavalent protactinium, hexavalent uranium, and plutonium (oxidation state uncertain) are present in much higher concentrations in Mono Lake, a saline, alkaline lake in eastern central California, than in seawater. Low ratios of actinium to protactinium and of americium to plutonium indicate that the concentrations of trivalent actinides are not similarly enhanced. The elevated concentrations of the ordinarily very insoluble actinides are maintained in solution by natural ligands, which inhibit their chemical removal from the water column, rather than by an unusually large rate of supply.

  3. Determination of Glucose Concentration in Yeast Culture Medium

    NASA Astrophysics Data System (ADS)

    Hara, Seiichi; Kishimoto, Tomokazu; Muraji, Masafumi; Tsujimoto, Hiroaki; Azuma, Masayuki; Ooshima, Hiroshi

    The present paper describes a sensor for measuring the glucose concentration of yeast culture medium. The sensor determines glucose concentration by measuring the yield of hydrogen peroxide produced by glucose oxidase, which is monitored as luminescence using photomultiplier. The present sensor is able to measure low glucose concentration in media in which yeast cells keep respiration state. We herein describe the system and the characteristics of the glucose sensor.

  4. Elevated glucose levels in early puerperium, and association with high cortisol levels during parturition.

    PubMed

    Risberg, Anitha; Sjöquist, Mats; Wedenberg, Kaj; Larsson, Anders

    2016-07-01

    Background Gestational diabetes is one of the commonest metabolic problems associated with pregnancy and an accurate diagnosis is critical for the care. Research has shown that pregnant women have high levels of cortisol during the last stage of parturition. As cortisol is a diabetogenic hormone causing increased glucose levels, we wanted to study the association between cortisol and glucose levels during parturition. Materials and methods Glucose and cortisol were analyzed during parturition in 50 females divided according to slow (n = 11) and normal labors (n = 39). Blood samples were analyzed three times during the parturition and four times in the first day after delivery. Glucose levels were also measured once in each trimester. Results In the normal group, the glucose concentration increased from 6.2 (IQR 5.6-8.0) mmol/L in the latency phase to 11.6 (10.0-13.3) mmol/L at aftercare (p < 0.05). After parturition the glucose concentrations decreased gradually. There were significant Spearman rank correlations between glucose and cortisol values. Conclusions The changes associated with birth cause significant elevations of cortisol and glucose around parturition.

  5. Acute elevation of endogenous prolactin does not influence glucose homeostasis in healthy men.

    PubMed

    Vigas, M; Klimes, I; Jurcovicová, J; Jezová, D

    1993-01-01

    The diabetogenic effect of prolactin observed in patients with pathological hyperprolactinaemia was verified in healthy subjects. Plasma prolactin elevation was induced by administration of a dopamine antagonist drug domperidone (Motilium 10 mg orally, 9 subjects) and 2 h later the oral glucose tolerance test was performed. The influence of dopamine receptor stimulation on glucose homeostasis was tested by dopamine infusion (0.3 mg in saline or 20% glucose, 1 g/min for 60 min, 11 subjects). After the blockade of dopamine receptors, a significant and prolonged increase of prolactin concentration was found. However, the levels of glucose, insulin, and C-peptide either before or after the glucose load were not different from control ones. The decreased number of insulin receptors (1.97 +/- 0.41 vs 0.51 +/- 0.14 pmol per 2.10(9) red blood cells) was compensated by increased affinity (0.51 +/- 0.17 vs 1.00 +/- 0.22 Ke 10(8) mol.-1 per l]) of insulin receptors. The stimulation of dopamine receptors showed a negligible effect on glucose regulation. It may be suggested that an endogenous increase of prolactin concentration in the physiological range does not participate in the regulation of glucose homeostasis in healthy subjects.

  6. Fever is not responsible for the elevated glucose kinetics in sepsis

    SciTech Connect

    Lang, C.H.; Bagby, G.J.; Blakesley, H.L.; Spitzer, J.J.

    1987-09-01

    Previous studies have suggested that alterations in the classical neuroendocrine system may not be responsible for the increased glucose metabolism observed during hypermetabolic sepsis. The purpose of the present study was to determine whether inhibition of the cyclooxygenase pathway with indomethacin, which prevents the production of arachidonic acid metabolites by this pathway and the sepsis-induced increase in body temperature, would abolish the increases in glucose appearance (Ra), recycling, and hyperlactacidemia. Sepsis was induced in chronically catheterized conscious rats by multiple injections of live Escherichia coli via a subcutaneous catheter. Septic animals received iv injections of indomethacin every 6-8 hr to block the cyclooxygenase pathway. Glucose kinetics were assessed in 24-hr fasted rats using a constant iv infusion of (6-/sup 3/H)- and (U-/sup 14/C) glucose. Treatment with indomethacin prevented the 1-2/sup 0/C increase in body temperature observed in septic animals. Septic rats exhibited an elevated plasma lactate concentration and increased rates of glucose appearance and recycling. The sepsis-induced alterations in these variables were not attenuated by indomethacin. These results suggest that neither elevated body temperature nor the generation of arachidonic acid metabolites of the cyclooxygenase pathway is responsible for increasing glucose production in hypermetabolic septic rats.

  7. Glucose concentration regulates freeze tolerance in the wood frog Rana sylvatica.

    PubMed

    Costanzo, J P; Lee, R E; Lortz, P H

    1993-08-01

    In spring, the lowest temperature during freezing that can be survived by wood frogs (Rana sylvatica) from southern Ohio is approximately -3 degrees C. We investigated whether the thermal limit of freeze tolerance in these frogs is regulated by tissue levels of glucose, a putative cryoprotectant that is distributed to tissues during freezing. Frogs receiving exogenous glucose injections prior to freezing showed dose-dependent increases in glucose within the heart, liver, skeletal muscle and blood. Tissue glucose concentrations were further elevated during freezing by the production of endogenous glucose. Most glucose-loaded frogs survived freezing to -5 degrees C, whereas all control (saline-injected) frogs succumbed. Further, we investigated some mechanisms by which glucose might function as a cryoprotectant in R. sylvatica. Organ dehydration, a normal, beneficial response that reduces freezing injury to tissues, occurred independently of tissue glucose concentrations. However, elevated glucose levels reduced both body ice content and in vivo erythrocyte injury. These results not only provided conclusive evidence for glucose's cryoprotective role in R. sylvatica, but also revealed that tissue glucose level is a critical determinant of freeze tolerance capacity in this species.

  8. Enzymatic Glucose Sensor Compensation for Variations in Ambient Oxygen Concentration

    PubMed Central

    Collier, Bradley B.; McShane, Michael J.

    2014-01-01

    Due to the increasing prevalence of diabetes, research toward painless glucose sensing continues. Oxygen sensitive phosphors with glucose oxidase (GOx) can be used to determine glucose levels indirectly by monitoring oxygen consumption. This is an attractive combination because of its speed and specificity. Packaging these molecules together in “smart materials” for implantation will enable non-invasive glucose monitoring. As glucose levels increase, oxygen levels decrease; consequently, the luminescence intensity and lifetime of the phosphor increase. Although the response of the sensor is dependent on glucose concentration, the ambient oxygen concentration also plays a key role. This could lead to inaccurate glucose readings and increase the risk of hyper- or hypoglycemia. To mitigate this risk, the dependence of hydrogel glucose sensor response on oxygen levels was investigated and compensation methods explored. Sensors were calibrated at different oxygen concentrations using a single generic logistic equation, such that trends in oxygen-dependence were determined as varying parameters in the equation. Each parameter was found to be a function of oxygen concentration, such that the correct glucose calibration equation can be calculated if the oxygen level is known. Accuracy of compensation will be determined by developing an overall calibration, using both glucose and oxygen sensors in parallel, correcting for oxygen fluctuations in real time by intentionally varying oxygen, and calculating the error in actual and predicted glucose levels. While this method was developed for compensation of enzymatic glucose sensors, in principle it can also be implemented with other kinds of sensors utilizing oxidases. PMID:26257458

  9. Yeast AMP-activated protein kinase monitors glucose concentration changes and absolute glucose levels.

    PubMed

    Bendrioua, Loubna; Smedh, Maria; Almquist, Joachim; Cvijovic, Marija; Jirstrand, Mats; Goksör, Mattias; Adiels, Caroline B; Hohmann, Stefan

    2014-05-02

    Analysis of the time-dependent behavior of a signaling system can provide insight into its dynamic properties. We employed the nucleocytoplasmic shuttling of the transcriptional repressor Mig1 as readout to characterize Snf1-Mig1 dynamics in single yeast cells. Mig1 binds to promoters of target genes and mediates glucose repression. Mig1 is predominantly located in the nucleus when glucose is abundant. Upon glucose depletion, Mig1 is phosphorylated by the yeast AMP-activated kinase Snf1 and exported into the cytoplasm. We used a three-channel microfluidic device to establish a high degree of control over the glucose concentration exposed to cells. Following regimes of glucose up- and downshifts, we observed a very rapid response reaching a new steady state within less than 1 min, different glucose threshold concentrations depending on glucose up- or downshifts, a graded profile with increased cell-to-cell variation at threshold glucose concentrations, and biphasic behavior with a transient translocation of Mig1 upon the shift from high to intermediate glucose concentrations. Fluorescence loss in photobleaching and fluorescence recovery after photobleaching data demonstrate that Mig1 shuttles constantly between the nucleus and cytoplasm, although with different rates, depending on the presence of glucose. Taken together, our data suggest that the Snf1-Mig1 system has the ability to monitor glucose concentration changes as well as absolute glucose levels. The sensitivity over a wide range of glucose levels and different glucose concentration-dependent response profiles are likely determined by the close integration of signaling with the metabolism and may provide for a highly flexible and fast adaptation to an altered nutritional status.

  10. Yeast AMP-activated Protein Kinase Monitors Glucose Concentration Changes and Absolute Glucose Levels*

    PubMed Central

    Bendrioua, Loubna; Smedh, Maria; Almquist, Joachim; Cvijovic, Marija; Jirstrand, Mats; Goksör, Mattias; Adiels, Caroline B.; Hohmann, Stefan

    2014-01-01

    Analysis of the time-dependent behavior of a signaling system can provide insight into its dynamic properties. We employed the nucleocytoplasmic shuttling of the transcriptional repressor Mig1 as readout to characterize Snf1-Mig1 dynamics in single yeast cells. Mig1 binds to promoters of target genes and mediates glucose repression. Mig1 is predominantly located in the nucleus when glucose is abundant. Upon glucose depletion, Mig1 is phosphorylated by the yeast AMP-activated kinase Snf1 and exported into the cytoplasm. We used a three-channel microfluidic device to establish a high degree of control over the glucose concentration exposed to cells. Following regimes of glucose up- and downshifts, we observed a very rapid response reaching a new steady state within less than 1 min, different glucose threshold concentrations depending on glucose up- or downshifts, a graded profile with increased cell-to-cell variation at threshold glucose concentrations, and biphasic behavior with a transient translocation of Mig1 upon the shift from high to intermediate glucose concentrations. Fluorescence loss in photobleaching and fluorescence recovery after photobleaching data demonstrate that Mig1 shuttles constantly between the nucleus and cytoplasm, although with different rates, depending on the presence of glucose. Taken together, our data suggest that the Snf1-Mig1 system has the ability to monitor glucose concentration changes as well as absolute glucose levels. The sensitivity over a wide range of glucose levels and different glucose concentration-dependent response profiles are likely determined by the close integration of signaling with the metabolism and may provide for a highly flexible and fast adaptation to an altered nutritional status. PMID:24627493

  11. An elevated 1-h post- load glucose level during the oral glucose tolerance test detects prediabetes.

    PubMed

    Buysschaert, Martin; Bergman, Michael; Yanogo, Donald; Jagannathan, Ram; Buysschaert, Benoit; Preumont, Vanessa

    The objective of the study was to compare the diagnosis of dysglycemic states by conventional oral glucose tolerance test (OGTT) criteria (fasting and 2-h plasma glucose) with the 1-h post-load plasma glucose level. 34 individuals (mean age: 55±13years; BMI: 27.7±6.3kg/m(2)) at risk for prediabetes were administered a 75g OGTT. Individuals with normal glucose tolerance (NGT) or prediabetes were identified according to fasting and/or 2-h plasma glucose (PG) concentrations. Subsequently, subjects were divided in 2 groups: group 1 (n=21) with a 1-h PG<155mg/dl and group 2 (n=13) with a 1-h PG≥155mg/dl. HOMA was performed to assess β-cell function and insulin sensitivity. NGT or prediabetes based on conventional criteria correlated with the 1-h PGglucose value ≥155mg/dl is strongly associated with conventional criteria for (pre)diabetes and alterations of β-cell function. Copyright © 2016 Diabetes India. Published by Elsevier Ltd. All rights reserved.

  12. Cutpoints for screening blood glucose concentrations in healthy senior cats.

    PubMed

    Reeve-Johnson, Mia K; Rand, Jacquie S; Vankan, Dianne; Anderson, Stephen T; Marshall, Rhett; Morton, John M

    2017-02-01

    Objectives The objectives of this study were to determine the reference interval for screening blood glucose in senior cats, to apply this to a population of obese senior cats, to compare screening and fasting blood glucose, to assess whether screening blood glucose is predicted by breed, body weight, body condition score (BCS), behaviour score, fasting blood glucose and/or recent carbohydrate intake and to assess its robustness to changes in methodology. Methods The study included a total of 120 clinically healthy client-owned cats aged 8 years and older of varying breeds and BCSs. Blood glucose was measured at the beginning of the consultation from an ear/paw sample using a portable glucose meter calibrated for cats, and again after physical examination from a jugular sample. Fasting blood glucose was measured after overnight hospitalisation and fasting for 18-24 h. Results The reference interval upper limit for screening blood glucose was 189 mg/dl (10.5 mmol/l). Mean screening blood glucose was greater than mean fasting glucose. Breed, body weight, BCS, behaviour score, fasting blood glucose concentration and amount of carbohydrate consumed 2-24 h before sampling collectively explained only a small proportion of the variability in screening blood glucose. Conclusions and relevance Screening blood glucose measurement represents a simple test, and cats with values from 117-189 mg/dl (6.5-10.5 mmol/l) should be retested several hours later. Cats with initial screening blood glucose >189 mg/dl (10.5 mmol/l), or a second screening blood glucose >116 mg/dl (6.4 mmol/l) several hours after the first, should have fasting glucose and glucose tolerance measured after overnight hospitalisation.

  13. Airway glucose concentrations and effect on growth of respiratory pathogens in cystic fibrosis.

    PubMed

    Brennan, Amanda L; Gyi, Khin M; Wood, David M; Johnson, Julie; Holliman, Rick; Baines, Deborah L; Philips, Barbara J; Geddes, Duncan M; Hodson, Margaret E; Baker, Emma H

    2007-04-01

    Pulmonary decline accelerates in cystic fibrosis-related diabetes (CFRD) proportional to severity of glucose intolerance, but mechanisms are unclear. In people without CF, airway glucose (AG) concentrations are elevated when blood glucose (BG)> or =8 mmol L(-1) (airway threshold), and are associated with acquisition of respiratory infection. To determine the relationship between BG and AG, 40 CF patients underwent paired BG and AG (nasal) measurements. Daily time with BG>airway threshold was compared in 10 CFRD, 10 CF patients with normal glucose tolerance (CF-NGT) and 10 healthy volunteers by continuous BG monitoring. The effect of glucose at airway concentrations on bacterial growth was determined in vitro by optical densitometry. AG was present more frequently (85%-vs.-19%, p<0.0001) and at higher concentrations (0.5-3 mmol L(-1)-vs.-0.5-1 mmol L(-1), p<0.0001) when BG was > or =8 mmol L(-1)-vs.-<8 mmol L(-1). Daily time with BG> or =8 mmol L(-1) was CFRD (49+/-25%), CF-NGT (6+/-5%), healthy volunteers (1+/-3%), p<0.0001. Staphylococcus aureus growth increased at > or =0.5 mmol L(-1) (p=0.006) and Pseudomonas aeruginosa growth above 1-4 mmol L(-1) glucose (p=0.039). BG> or =8 mmol L(-1) predicted elevated AG concentrations in CF, at least in nasal secretions. CFRD patients spent approximately 50% day with BG>airway threshold, implying persistently elevated AG concentrations. Further studies are required to determine whether elevated airway glucose concentrations contribute to accelerated pulmonary decline in CFRD.

  14. Effect of different glucose concentrations on proteome of Saccharomyces cerevisiae.

    PubMed

    Guidi, Francesca; Francesca, Guidi; Magherini, Francesca; Francesca, Magherini; Gamberi, Tania; Tania, Gamberi; Borro, Marina; Marina, Borro; Simmaco, Maurizio; Maurizio, Simmaco; Modesti, Alessandra; Alessandra, Modesti

    2010-07-01

    We performed a proteomic study to understand how Saccharomyces cerevisiae adapts its metabolism during the exponential growth on three different concentrations of glucose; this information will be necessary to understand yeast carbon metabolism in different environments. We induced a natural diauxic shift by growing yeast cells in glucose restriction thus having a fast and complete glucose exhaustion. We noticed differential expressions of groups of proteins. Cells in high glucose have a decreased growth rate during the initial phase of fermentation; in glucose restriction and in high glucose we found an over-expression of a protein (Peroxiredoxin) involved in protection against oxidative stress insult. The information obtained in our study validates the application of a proteomic approach for the identification of the molecular bases of environmental variations such as fermentation in high glucose and during a naturally induced diauxic shift.

  15. Continuous detection of glucose concentration by fluorescent indicator

    NASA Astrophysics Data System (ADS)

    Shi, Ting; Li, Dachao; Li, Guoqing; Lu, Lou; Xu, Kexin

    Continuous glucose detection has a great significance for diabetics. On the one hand, it can fully reflect the patient blood glucose change level. On the other hand, it can better guide the insulin dosage, and achieve closed-loop control of insulin pump. A continuous detection method of glucose concentration by borate polymer fluorescent indicator is proposed in the paper. The principle of this method is based on the competing reaction between alizarin, glucose and borate polymer. The borate polymer has high specific reaction with glucose, meanwhile reacts with non fluorescent alizarin. The product of the reaction between borate polymer and alizarin is fluorescent, called as fluorescent indicator. When glucose was introduced, the glucose molecules could react with the borate polymer in fluorescent indicator because of the high specificity. This competing process leads to the decomposition of fluorescent indicator into the non-fluorescent alizarin, and the fluorescent intensity gets loss. Therefore, the change of fluorescent intensity can reflect the glucose concentration level. In this method, the fluorescent indicator can well identify the glucose molecules. According to the experiment, we know that there is a high specific and good linear reaction between glucose and borate polymer. The linear fitting is up to 0.97 and the detection limitation can reach to 10 mg/dL. The fluorescent intensity reaches strongest with the optimal proportion of alizarin: borate polymer as 1:3. The reaction of the fluorescent indicator identifying glucose molecules has a good linear relationship, the linear fitting of which can reach to 0.98. The detection limitation can reach to 30 mg/dL, which fulfills the detection requirements of glucose concentration in vivo.

  16. Modification and evolution of Gluconobacter oxydans for enhanced growth and biotransformation capabilities at low glucose concentration.

    PubMed

    Zhu, Kun; Lu, Leifang; Wei, Liujing; Wei, Dongzhi; Imanaka, Tadayuki; Hua, Qiang

    2011-09-01

    Gluconobacter oxydans is widely used in several biotechnological applications, where sorbitol or mannitol is commonly used as carbon source at high concentration. In this study, a membrane-bound glucose dehydrogenase-deficient strain (GDHK) was constructed to eliminate growth problems on glucose caused by direct oxidation of glucose in the medium. To achieve improved growth properties for the GDHK strain on glucose, a laboratory adaptive evolution experiment was performed with glucose as the sole carbon source. Results indicated evident, albeit modest, improvements in cell growth after a 50-day (about 430 generations) experimental evolution on glucose. The maximum specific growth rate and biomass yield of the resulting GDHE50 strain were increased around 1.35- to 1.4-fold compared with those of the GDHK strain. Meanwhile, two types of biotransformation reactions using resting cells of G. oxydans were investigated. Significant elevations in biotransformation performance of the GHDE50 strain were observed in comparison with that of the wild-type strain. In addition, resting cells of the GDHE50 strain grown on a relatively low concentration of glucose (10 g/l) could catalyze the biotransformation of glycerol to dihydroxyacetone and ethylene glycol to glycolic acid as efficient as the wild-type G. oxydans cultured on higher concentration of sorbitol or other carbon sources. These results suggest very favorable prospects of using glucose to lower production cost in many important industrial biocatalysis and biotransformation processes.

  17. Differential Mueller matrix polarimetry for low concentration of glucose sensing

    NASA Astrophysics Data System (ADS)

    Phan, Quoc-Hung; Lo, Yu-Lung

    2017-04-01

    A novel of glucose sensing method based on differential Mueller matrix polarimetry is proposed. An analytical model is derived for extracting the optical rotation angle (γ) and degree of depolarization properties (Δ) of glucose sample with scattering affects. The practical feasibility of the proposed method is demonstrated by the experimental results for the sensitivity of the γ and Δ with the glucose samples with 2% phantom particles. The results show that the extracted valued of γ and Δ vary linearly with the glucose concentration over the measured range of 0 to 100 mg/dl with lowest increment of 20 mg/dl. In general, the proposed technique provides a reliable and simple method for low concentration of glucose sensing.

  18. Impedance spectroscopy of solutions at physiological glucose concentrations.

    PubMed

    Tura, A; Sbrignadello, S; Barison, S; Conti, S; Pacini, G

    2007-09-01

    Impedance spectroscopy has been proposed as possible approach for non-invasive glycaemia monitoring. However, few quantitative data are reported about impedance variations related to glucose concentration variations, especially below the MHz band. Furthermore, it is not clear whether glucose directly affects the impedance parameters or only indirectly by inducing biochemical phenomena. We investigated the impedance variations in glucose-water, glucose-sodium chloride, and glucose-blood samples, for increasing glucose values (up to 300 mg/dl). In all the frequency range (0.1-10(7) Hz) glucose-water samples showed impedance modulus increases for increasing glucose values (up to 135%). In blood and sodium chloride samples the impedance modulus showed only slight variations (2% and 1.4%), but again in wide frequency ranges. Therefore: i) glucose directly affects the impedance parameters of solutions; ii) effects are more relevant at frequencies below the MHz band; iii) the influence on the impedance is decreased in high conductivity solutions, but still clearly present.

  19. Optoacoustic signal profiles for monitoring glucose concentration in turbid media

    NASA Astrophysics Data System (ADS)

    Larin, Kirill V.; Oraevsky, Alexander A.

    1999-03-01

    Our research project is focused on theoretical and experimental studies into the possibility of in vivo monitoring of blood glucose concentration. Previous experiments demonstrated that the presence of glucose dissolved in aqueous solution of polystyrene microspheres increases the refractive index of this solution due to glucose hydrophilic properties. As a strong osmolyte glucose influences the scattering properties of any particles or fibers suspended in water or biological fluids. We measured profiles of absorbed laser energy distributions as a function of glucose concentration in aqueous solution of polystyrene microspheres colored with potassium chromate. Experiments were performed at the wavelength of the Nd:YAG laser third harmonic, (lambda) equals 355 nm. The results obtained demonstrated a 4.5% decrease in effective optical attenuation coefficient with a 100 mM increase in glucose concentration. These initial results demonstrated that the effect of glucose on optical attenuation of turbid aqueous solutions is small but reliably measurable with the use of the time-resolved optoacoustic technique.

  20. Increased maternal nighttime cortisol concentrations in late gestation alter glucose and insulin in the neonatal lamb

    PubMed Central

    Antolic, Andrew; Feng, Xiaodi; Wood, Charles E; Richards, Elaine M; Keller-Wood, Maureen

    2015-01-01

    Previous studies in our laboratory have shown that a modest chronic increase in maternal cortisol concentrations impairs maternal glucose metabolism and increases the incidence of perinatal stillbirth. The dramatic outcomes prevented our ability to study the effects of maternal hypercortisolemia on neonatal growth, glucose metabolism, and hypothalamo–pituitary–adrenal axis response. Therefore, we developed a model in which pregnant ewes are infused for 12 h/day at 0.5 mg·kg–1·day–1 from day 115 of gestation until delivery (˜145), elevating nighttime plasma cortisol concentrations. This pattern of elevation of cortisol mimics that in patients with elevated evening cortisol concentrations, as in Cushing’s syndrome or chronic depression. Plasma cortisol, glucose, insulin, and electrolytes were measured during pregnancy and postpartum in control and cortisol-infused ewes and their postnatal lambs for the first 14 days after delivery. Neonatal growth and plasma ACTH, aldosterone, renin activity, and electrolytes, and organ weights at 14 days of age were also measured. Infusion of cortisol increased maternal plasma cortisol during pregnancy but not postpartum, and did not alter neonatal ACTH or cortisol. Although maternal glucose and insulin concentrations were not changed by the maternal infusion of cortisol, neonatal plasma glucose was increased and plasma insulin was decreased compared to those in the control group. Neonatal ponderal index and kidney weight were reduced, left ventricular wall thickness was increased, and plasma sodium and creatinine were increased after maternal cortisol infusion. These results suggest that excess maternal cortisol concentrations in late gestation alter growth, glucose and insulin regulation, and organ maturation in the neonate. PMID:26371232

  1. Determination of glucose concentration using Fourier domain optical coherence tomogram

    NASA Astrophysics Data System (ADS)

    El-Sharkawy, Yasser H.

    2009-02-01

    In order to enhance cell culture growth in biosensors such as those for glucose detection must be developed that are capable of monitoring cell culture processes continuously and accurate. Fourier domain optical coherence tomography (FD-OCT) is used to obtain cell images with nanometer level resolution by analyzing the interference pattern by the mixing of reference and objective light to determine glucose concentration in doped double distilled water and create a glucose signature spectrum in salt-sugar solution. We demonstrate ultrahigh-resolution optical coherence tomography (OCT) imaging of in vitro biological cells and an improved deflection angle measurements formal and back projection method is used to reconstruct the two-dimensional glucose concentration performs refractive index distribution. Slopes of OCT signals decreased substantially and almost linearly with the increase of glucose concentration from 2.5 to 15 mg/dl. Phantom studies demonstrated 1% accuracy of scattering- coefficient measurement. Our theoretical and experimental studies suggest that glucose concentration can potentially be measured non-invasively with high sensitivity and accuracy with OCT systems.

  2. Visfatin concentrations in obese patients in relation to the presence of newly diagnosed glucose metabolism disorders.

    PubMed

    Kamińska, Anna; Kopczyńska, Ewa; Bieliński, Maciej; Borkowska, Alina; Junik, Roman

    2015-01-01

    Visfatin, protein secreted by visceral adipose tissue, exerts insulin-mimetic actions. Visfatin concentration increases in patients with longer-standing diabetes type 2 with progressive b-cell dysfunction. Data about the role of visfatin in newly diagnosed glucose metabolism abnormalities are limited. Evaluation of visfatin concentration in patients with obesity, in relation to the presence of newly diagnosed glucose metabolism disorders. The study included 68 subjects with obesity, without a previous diagnosis of abnormal glucose metabolism. In all subjects we performed an oral glucose tolerance test, and according to the results the group was divided into the subgroups: A (n = 31), with glucose metabolism disorders (impaired fasting glucose, impaired glucose tolerance and type 2 diabetes); and B (n = 37), without abnormalities. In all subjects serum lipids, uric acid, C-peptide, glycated haemoglobin (HbA1c), creatinine, and serum visfatin concentrations were measured. The control group comprised 30 lean, healthy individuals with normal glucose tolerance. We found elevated visfatin levels in obese individuals versus the control group (50.0 ± 48 vs. 26.7 ± 22.1 ng/mL; p = 0.01). Visfatin concentrations in both subgroups, A and B, did not differ (40.86 ± 27.84 vs. 57.7 ± 59.79 ng/mL; p = 0.19). In subgroup A visfatin concentration correlated significantly with triglycerides (r = 0.37, p = 0.038), HbA1c (r = -0.43, p = 0.02), C-peptide (r = -0.38,p = 0.048), and waist-hip ratio (r = -0.41, p = 0.036). The presence of newly diagnosed glucose metabolism abnormalities in obese subjects had no influence on the visfatin level, probably due to preserved endogenous insulin secretion and relatively short exposure to hyperglycaemia in patients with prediabetes or at early stage of type 2 diabetes.

  3. Effect of Cinnamon Tea on Postprandial Glucose Concentration

    PubMed Central

    Bernardo, Maria Alexandra; Santos, Elisabeth; Moncada, Margarida Maria; Singh, Jaipaul; de Mesquita, Maria Fernanda

    2015-01-01

    Glycaemic control, in particular at postprandial period, has a key role in prevention of different diseases, including diabetes and cardiovascular events. Previous studies suggest that postprandial high blood glucose levels (BGL) can lead to an oxidative stress status, which is associated with metabolic alterations. Cinnamon powder has demonstrated a beneficial effect on postprandial glucose homeostasis in animals and human models. The purpose of this study is to investigate the effect of cinnamon tea (C. burmannii) on postprandial capillary blood glucose level on nondiabetic adults. Participants were given oral glucose tolerance test either with or without cinnamon tea in a randomized clinical trial. The data revealed that cinnamon tea administration slightly decreased postprandial BGL. Cinnamon tea ingestion also results in a significantly lower postprandial maximum glucose concentration and variation of maximum glucose concentration (p < 0.05). Chemical analysis showed that cinnamon tea has a high antioxidant capacity, which may be due to its polyphenol content. The present study provides evidence that cinnamon tea, obtained from C. burmannii, could be beneficial for controlling glucose metabolism in nondiabetic adults during postprandial period. PMID:26258147

  4. IR spectroscopy vs. Raman scattering by measurement of glucose concentration

    NASA Astrophysics Data System (ADS)

    Abdallah, O.; Hansmann, J.; Bolz, A.; Mertsching, H.

    2010-11-01

    By developing a non-invasive device for glucose concentration measurement, two promising methods were compared for that aim. The Raman scattering using Laser at the wavelength 785 nm and the light scattering in R- and IR-range are demonstrated. An easy accessible and low-cost method for glucose concentration monitoring and management to avoid its complications will be a great help for diabetic patients. Raman Scattering is a promising method for noninvasively measuring of glucose and for the diagnostic of pathological tissue variations. Despite the power and the time of measurement can be reduced using enhanced Raman scattering, it will be difficult to develop a compatible device with low power Laser and low price for a non-invasive method for home monitoring. As using IR-spectroscopy at wavelengths slightly below 10000 nm, the absorption of glucose can be well discriminated from that of water, LED`s or LD's at these wavelengths are very expensive for this purpose. At wavelengths about 6250 and 7700 glucose has a less light absorption than water. Also slightly above 3000 nm glucose has a high absorption. There are also possibilities for the measurement in the NIR at wavelengths between 1400 nm and 1670 nm. Scattering measurements at wavelengths below 900 nm and our measurements with the wavelength about 640 nm give reproducible glucose dependence on the reflected light from a glucose solution at a constant temperature. A multi-sensor with different wavelengths and temperature sensor will be a good choice for in-vivo glucose monitoring.

  5. Elevated Fibroblast Growth Factor-2 Increases Tumor Necrosis Factor-α Induced Endothelial Cell Death in High Glucose

    PubMed Central

    Clyne, Alisa Morss; Zhu, Han; Edelman, Elazer R.

    2010-01-01

    Glucose and tumor necrosis factor-α (TNFα) concentrations are elevated in diabetes. Both of these factors correlate with diabetic vasculopathy and endothelial cell apoptosis, yet their combined effects have not been measured. We have previously shown that the angiogenic growth factor fibroblast growth factor-2 (FGF-2), which is generally protective against endothelial cell death, is similarly elevated in high glucose conditions. We therefore investigated the effect of TNFα on endothelial cell death under normal and elevated glucose conditions, with a particular focus on FGF-2. Porcine aortic endothelial cells were cultured in 5 and 30 mM glucose and stimulated with TNFα, together with FGF-2 or a neutralizing FGF-2 antibody. Cell death was measured via cell counts or an annexin apoptotic assay, and cell cycle phase was determined by propidium iodide labeling. TNFα-induced endothelial cell death increased for cells in high glucose, and cell death was enhanced with increasing FGF-2 exposure and negated by a neutralizing FGF-2 antibody. Endothelial cells were most susceptible to TNFα-induced cell death when stimulated with FGF-2 18 h prior to TNFα, corresponding to cell entry into S phase of the proliferative cycle. The FGF-2 associated increase in TNFα-induced cell death was negated by blocking cell entry into S phase. Endothelial cell release of FGF-2 in high glucose leads to cell cycle progression, which makes cells more susceptible to TNFα-induced cell death. These data suggest that growth factor outcomes in high glucose depend on secondary mediators such as cytokines and stimulation cell cycle timing. PMID:18446810

  6. Influence of glucose concentration on the structure and quantity of biofilms formed by Candida parapsilosis.

    PubMed

    Pereira, Leonel; Silva, Sónia; Ribeiro, Bruno; Henriques, Mariana; Azeredo, Joana

    2015-08-01

    Candida parapsilosis is nowadays an emerging opportunistic pathogen and its increasing incidence is part related to the capacity to produce biofilm. In addition, one of the most important C. parapsilosis pathogenic risk factors includes the organisms' selective growth capabilities in hyperalimentation solutions. Thus, in this study, we investigated the role of glucose in C. parapsilosis biofilm modulation, by studying biofilm formation, matrix composition, and structure. Moreover, the expression of biofilm-related genes (BCR1, FKS1 and OLE1) was analysed in the presence of different glucose percentages. The results demonstrated the importance of glucose in the modulation of C. parapsilosis biofilm. The concentration of glucose had direct implications on the C. parapsilosis transition of yeast cells to pseudohyphae. Additionally, it was demonstrated that biofilm-related genes BCR1, FKS1, and OLE1 are involved in biofilm modulation as a result of glucose. The mechanism by which glucose enhances biofilm formation is not fully understood; however, with this study we were able to demonstrate that C. parapsilosis responds to stress conditions caused by elevated levels of glucose by upregulating genes related to biofilm formation (BCR1, FKS1 and OLE1).

  7. The sweet life: diet sugar concentration influences paracellular glucose absorption.

    PubMed

    Napier, Kathryn R; Purchase, Cromwell; McWhorter, Todd J; Nicolson, Susan W; Fleming, Patricia A

    2008-10-23

    Small birds and bats face strong selection pressure to digest food rapidly in order to reduce digesta mass carried during flight. One mechanism is rapid absorption of a high proportion of glucose via the paracellular pathway (transfer between epithelial cells, not mediated by transporter proteins). Intestinal paracellular permeability to glucose was assessed for two nectarivorous passerines, the Australian New Holland honeyeater (Phylidonyris novaehollandiae) and African white-bellied sunbird (Cinnyris talatala) by measuring the bioavailability of radiolabelled, passively absorbed L-glucose. Bioavailability was high in both species and increased with diet sugar concentration (honeyeaters, 37 and 81% and sunbirds, 53 and 71% for 250 and 1,000 mmoll-1 sucrose diets, respectively). We conclude that the relative contribution of paracellular to total glucose absorption increases with greater digesta retention time in the intestine, and paracellular absorption may also be modulated by factors such as intestinal lumen osmolality and interaction with mediated glucose uptake. The dynamic state of paracellular absorption should be taken into account in future studies.

  8. Fluorescence lifetime measurements of boronate derivatives to determine glucose concentration

    SciTech Connect

    Gable, J H

    2000-06-01

    A novel investigation into the fluorescence lifetimes of molecules, both established and newly designed, was performed. These molecules are the basis of a continuous, minimally invasive, glucose sensor based on fluorescence lifetime measurements. This sensor, if coupled with an automated insulin delivery device, would effectively create an artificial pancreas allowing for the constant monitoring and control of glucose levels in a person with diabetes. The proposed sensor includes a fluorescent molecule that changes its' fluorescence properties upon binding selectively and reversibly to glucose. One possible sensor molecule is N-methyl-N-(9-methylene anthryl)-2-methylenephenylboronic acid (AB). The fluorescence intensity of AB was shown to change in response to changing glucose concentrations. (James, 1994) James proposed that when glucose binds to AB the fluorescence intensity increases due to an enhancement of the N{yields}B dative bond which prevents photoinduced electron transfer (PET). PET from the amine (N) to the fluorophore (anthracene) quenches the fluorescence. The dative bond between the boron and the amine can prevent PET by involving the lone pair of electrons on the amine in interactions with the boron rather than allowing them to be transferred to the fluorophore. Results of this research show the average fluorescence lifetime of AB also changes with glucose concentration. It is proposed that fluorescence is due to two components: (1) AB with an enhanced N{yields}B interaction, and no PET, and (2) AB with a weak N{yields}B interaction, resulting in fluorescence quenching by PET. Lifetime measurements of AB as a function of both the pH of the solvent and glucose concentration in the solution were made to characterize this two component system and investigate the nature of the N{yields}B bond. Measurements of molecules similar to AB were also performed in order to isolate behavior of specific AB constituents. These molecules are 9-(Methylaminomethyl

  9. Proteins altered by elevated levels of palmitate or glucose implicated in impaired glucose-stimulated insulin secretion

    PubMed Central

    Sol, E-ri M; Hovsepyan, Meri; Bergsten, Peter

    2009-01-01

    Background Development of type 2 diabetes mellitus (T2DM) is characterized by aberrant insulin secretory patterns, where elevated insulin levels at non-stimulatory basal conditions and reduced hormonal levels at stimulatory conditions are major components. To delineate mechanisms responsible for these alterations we cultured INS-1E cells for 48 hours at 20 mM glucose in absence or presence of 0.5 mM palmitate, when stimulatory secretion of insulin was reduced or basal secretion was elevated, respectively. Results After culture, cells were protein profiled by SELDI-TOF-MS and 2D-PAGE. Differentially expressed proteins were discovered and identified by peptide mass fingerprinting. Complimentary protein profiles were obtained by the two approaches with SELDI-TOF-MS being more efficient in separating proteins in the low molecular range and 2D-PAGE in the high molecular range. Identified proteins included alpha glucosidase, calmodulin, gars, glucose-6-phosphate dehydrogenase, heterogenous nuclear ribonucleoprotein A3, lon peptidase, nicotineamide adenine dinucleotide hydrogen (NADH) dehydrogenase, phosphoglycerate kinase, proteasome p45, rab2, pyruvate kinase and t-complex protein. The observed glucose-induced differential protein expression pattern indicates enhanced glucose metabolism, defense against reactive oxygen species, enhanced protein translation, folding and degradation and decreased insulin granular formation and trafficking. Palmitate-induced changes could be related to altered exocytosis. Conclusion The identified altered proteins indicate mechanism important for altered β-cell function in T2DM. PMID:19607692

  10. Glucose Recognition Proteins for Glucose Sensing at Physiological Concentrations and Temperatures

    PubMed Central

    2015-01-01

    Advancements in biotechnology have allowed for the preparation of designer proteins with a wide spectrum of unprecedented chemical and physical properties. A variety of chemical and genetic methods can be employed to tailor the protein’s properties, including its stability and various functions. Herein, we demonstrate the production of semisynthetic glucose recognition proteins (GRPs) prepared by truncating galactose/glucose binding protein (GBP) of E. coli and expanding the genetic code via global incorporation of unnatural amino acids into the structure of GBP and its fragments. The unnatural amino acids 5,5,5-trifluoroleucine (FL) and 5-fluorotryptophan (FW) were chosen for incorporation into the proteins. The resulting semisynthetic GRPs exhibit enhanced thermal stability and increased detection range of glucose without compromising its binding ability. These modifications enabled the utilization of the protein for the detection of glucose within physiological concentrations (mM) and temperatures ranging from hypothermia to hyperthermia. This ability to endow proteins such as GBP with improved stability and properties is critical in designing the next generation of tailor-made biosensing proteins for continuous in vivo glucose monitoring. PMID:24841549

  11. Influence of artificial sweetener on human blood glucose concentration.

    PubMed

    Skokan, Ilse; Endler, P Christian; Wulkersdorfer, Beatrix; Magometschnigg, Dieter; Spranger, Heinz

    2007-10-05

    Artificial sweeteners, such as saccharin or cyclamic acid are synthetically manufactured sweetenings. Known for their low energetic value they serve especially diabetic and adipose patients as sugar substitutes. It has been hypothesized that the substitution of sugar with artificial sweeteners may induce a decrease of the blood glucose. The aim of this study was to determine the reliability of this hypothesis by comparing the influence of regular table sugar and artificial sweeteners on the blood glucose concentration. In this pilot-study 16 patients were included suffering from adiposity, pre-diabetes and hypertension. In the sense of a cross-over design, three test trials were performed at intervals of several weeks. Each trial was followed by a test free interval. Within one test trial each patient consumed 150 ml test solution (water) that contained either 6 g of table sugar ("Kandisin") with sweetener free serving as control group. Tests were performed within 1 hr after lunch to ensure conditions comparable to patients having a desert. Every participant had to determine their blood glucose concentration immediately before and 5, 15, 30 and 60 minutes after the intake of the test solution. For statistics an analysis of variance was performed. The data showed no significant changes in the blood glucose concentration. Neither the application of sugar (F(4;60) = 1.645; p = .175) nor the consumption of an artificial sweetener (F(2.068;31.023) = 1.551; p > .05) caused significant fluctuations in the blood sugar levels. Over a time frame of 60 minutes in the control group a significant decrease of the blood sugar concentration was found (F(2.457;36.849) = 4.005; p = .020) as a physiological reaction during lunch digestion.

  12. Effect of transmucosal corn syrup application on postoperative blood glucose concentrations in kittens.

    PubMed

    Cornell, Heather N; Shaver, Stephanie L; Semick, Danielle N; Bradley, Nancy C; Kreisler, Rachael E

    2017-04-01

    Objectives The aim of the study was to determine the effect of a common clinical practice, the transmucosal (TM) application of corn syrup, on postoperative blood glucose concentrations in kittens. Methods This study was designed as a randomized controlled trial. Seventy-five kittens between the age of 8 and 16 weeks scheduled for surgical sterilization by gonadectomy at an animal shelter were enrolled. Kittens were randomly assigned to either a routine treatment group that received the shelter's typical postoperative application of corn syrup immediately following gonadectomy or to a control group that did not receive typical treatment. Three blood glucose measurements were obtained per kitten: baseline reading prior to preoperative examination, immediately postoperatively and 20 mins postoperatively. The median values of the 20 min postoperative blood glucose reading for the control and treatment groups were compared using the Wilcoxon rank-sum test. Results Postoperative application of corn syrup to the oral mucosa of kittens did not result in significant elevations in blood glucose compared with controls. No kitten was hypoglycemic (⩽60 mg/dl) at any point during the study. Conclusions and relevance TM application of corn syrup did not affect postoperative blood glucose concentrations in kittens. Protocols that use routine TM administration of corn syrup in kittens should be re-evaluated.

  13. Growth under elevated atmospheric CO(2) concentration accelerates leaf senescence in sunflower (Helianthus annuus L.) plants.

    PubMed

    de la Mata, Lourdes; Cabello, Purificación; de la Haba, Purificación; Agüera, Eloísa

    2012-09-15

    Some morphogenetic and metabolic processes were sensitive to a high atmospheric CO(2) concentration during sunflower primary leaf ontogeny. Young leaves of sunflower plants growing under elevated CO(2) concentration exhibited increased growth, as reflected by the high specific leaf mass referred to as dry weight in young leaves (16 days). The content of photosynthetic pigments decreased with leaf development, especially in plants grown under elevated CO(2) concentrations, suggesting that high CO(2) accelerates chlorophyll degradation, and also possibly leaf senescence. Elevated CO(2) concentration increased the oxidative stress in sunflower plants by increasing H(2)O(2) levels and decreasing activity of antioxidant enzymes such as catalase and ascorbate peroxidase. The loss of plant defenses probably increases the concentration of reactive oxygen species in the chloroplast, decreasing the photosynthetic pigment content as a result. Elevated CO(2) concentration was found to boost photosynthetic CO(2) fixation, especially in young leaves. High CO(2) also increased the starch and soluble sugar contents (glucose and fructose) and the C/N ratio during sunflower primary leaf development. At the beginning of senescence, we observed a strong increase in the hexoses to sucrose ratio that was especially marked at high CO(2) concentration. These results indicate that elevated CO(2) concentration could promote leaf senescence in sunflower plants by affecting the soluble sugar levels, the C/N ratio and the oxidative status during leaf ontogeny. It is likely that systemic signals produced in plants grown with elevated CO(2), lead to early senescence and a higher oxidation state of the cells of these plant leaves. Copyright © 2012 Elsevier GmbH. All rights reserved.

  14. Carbohydrate Ingestion Before and During Soccer Match Play and Blood Glucose and Lactate Concentrations

    PubMed Central

    Russell, Mark; Benton, David; Kingsley, Michael

    2014-01-01

    Context: The ingestion of carbohydrate (CHO) before and during exercise and at halftime is commonly recommended to soccer players for maintaining blood glucose concentrations throughout match play. However, an exercise-induced rebound glycemic response has been observed in the early stages of the second half of simulated soccer-specific exercise when CHO-electrolyte beverages were consumed regularly. Therefore, the metabolic effects of CHO beverage consumption throughout soccer match play remain unclear. Objective: To investigate the blood glucose and blood lactate responses to CHOs ingested before and during soccer match play. Design: Crossover study. Setting: Applied research study. Patients or Other Participants: Ten male outfield academy soccer players (age = 15.6 ± 0.2 years, height = 1.74 ± 0.02 m, mass = 65.3 ± 1.9 kg, estimated maximal oxygen consumption = 58.4 ± 0.8 mL·kg−1·min−1). Intervention(s): Players received a 6% CHO-electrolyte solution or an electrolyte (placebo) solution 2 hours before kickoff, before each half (within 10 minutes), and every 15 minutes throughout exercise. Blood samples were obtained at rest, every 15 minutes during the match (first half: 0–15, 15–30, and 30–45 minutes; second half: 45–60, 60–75, and 75–90 minutes) and 10 minutes into the halftime break. Main Outcome Measure(s): Metabolic responses (blood glucose and blood lactate concentrations) and markers of exercise intensity (heart rate) were recorded. Results: Supplementation influenced the blood glucose response to exercise (time × treatment interaction effect: P ≤ .05), such that glucose concentrations were higher at 30 to 45 minutes in the CHO than in the placebo condition. However, in the second half, blood glucose concentrations were similar between conditions because of transient reductions from peak values occurring in both trials at halftime. Blood lactate concentrations were elevated above those at rest in the first 15 minutes of exercise

  15. Ozone concentration characteristics at a high-elevation forest site

    Treesearch

    G. Wooldridge; K. Zeller; R. Musselman

    1997-01-01

    Atmospheric ozone concentrations have been monitored at a subalpine forest ecosystem site, 3180m above mean sea level (msl), and at a 2680m msl forest-steppe ecotone site 15km to the southeast. Ozone concentrations were monitored at three heights above the ground on a 30m tower at the higher elevation site, and on a 10m tower in a large meadow downwind of this site....

  16. Elevated glucose levels impair the WNT/β-catenin pathway via the activation of the hexosamine biosynthesis pathway in endometrial cancer.

    PubMed

    Zhou, Fuxing; Huo, Junwei; Liu, Yu; Liu, Haixia; Liu, Gaowei; Chen, Ying; Chen, Biliang

    2016-05-01

    Endometrial cancer (EC) is one of the most common gynecological malignancies in the world. Associations between fasting glucose levels (greater than 5.6mmol/L) and the risk of cancer fatality have been reported. However, the underlying link between glucose metabolic disease and EC remains unclear. In the present study, we explored the influence of elevated glucose levels on the WNT/β-catenin pathway in EC. Previous studies have suggested that elevated concentrations of glucose can drive the hexosamine biosynthesis pathway (HBP) flux, thereby enhancing the O-GlcNAc modification of proteins. Here, we cultured EC cell lines, AN3CA and HEC-1-B, with various concentrations of glucose. Results showed that when treated with high levels of glucose, both lines showed increased expression of β-catenin and O-GlcNAcylation levels; however, these effects could be abolished by the HBP inhibitors, Azaserine and 6-Diazo-5-oxo-l-norleucine, and be restored by glucosamine. Moreover the AN3CA and HEC-1-B cells that were cultured with or without PUGNAc, an inhibitor of the O-GlcNAcase, showed that PUGNAc increased β-catenin levels. The results suggest that elevated glucose levels increase β-catenin expression via the activation of the HBP in EC cells. Subcellular fractionation experiments showed that AN3CA cells had a higher expression of intranuclear β-catenin in high glucose medium. Furthermore, TOP/FOP-Flash and RT-PCR results showed that glucose-induced increased expression of β-catenin triggered the transcription of target genes. In conclusion, elevated glucose levels, via HBP, increase the O-GlcNAcylation level, thereby inducing the over expression of β-catenin and subsequent transcription of the target genes in EC cells.

  17. Elevated Fasting Plasma Glucose before Liver Transplantation is Associated with Lower Post-Transplant Survival

    PubMed Central

    Katsura, Emi; Ichikawa, Tatsuki; Taura, Naota; Miyaaki, Hisamitsu; Miuma, Satoshi; Shibata, Hidetaka; Honda, Takuya; Hidaka, Masaaki; Soyama, Akihiko; Takeshima, Fuminao; Eguchi, Susumu; Nakao, Kazuhiko

    2016-01-01

    Background The risk of liver cirrhosis is higher among individuals with diabetes mellitus, and a cirrhotic patient with diabetes may have a poorer prognosis after liver transplantation compared to a patient without diabetes. Thus, we evaluated whether fasting plasma glucose prior to receiving a liver transplant was a prognostic factor for post-transplant survival. Material/Methods Ninety-one patients received a living donor liver transplant between November 2005 and December 2012. Patients were considered diabetic if they were prescribed diabetes medications or had impaired glucose tolerance as measured by an oral glucose tolerance test. Each patient was monitored through December 31, 2013, to evaluate prognosis. Results Fasting plasma glucose of at least 100 mg/dL significantly decreased survival following transplant (52% in the high FPG group compared to 78% in the control group, p=0.04), while postprandial hyperglycemia had no effect on survival. Additionally, overall mortality and the incidence of vascular disease were significantly higher among patients with uncontrolled plasma glucose. Impaired fasting plasma glucose was significantly and inversely associated with overall survival in the univariate and multivariate analyses, while creatinine (at least 1 mg/dL) was inversely associated with survival in the univariate analysis. Conclusions Elevated fasting plasma glucose prior to liver transplantation was inversely associated with post-transplant survival. This effect may be due to underlying microangiopathy as a result of uncontrolled diabetes before transplantation. Our data demonstrated the importance of controlled blood glucose prior to liver transplantation. PMID:27909287

  18. Elevated Plasma Homocysteine Concentration in Opium-Addicted Individuals

    PubMed Central

    Masoomi, Mohammad; Azdaki, Nahid; Shahouzehi, Beydolah

    2015-01-01

    Background Although the triggering role of both opium use and elevated plasma homocysteine level for progressing atherosclerosis and, therefore, appearing coronary heart disease has been clearly determined, no study are available with respect to the relation between these to risk profiles. In the present study and for the first time, we hypothesized that the opium addiction can be potentially correlated with elevated homocysteine concentration. Methods 217 persons (103 opium-addicted and 114 non-addicted) were randomly selected from the Kerman Coronary Artery Disease Risk Study (KERCADRS), Iran, as a population-based, epidemiological prospective study. In all participants, an enzyme immunoassay kit was used to measure homocysteine in serum samples. Findings The serum level of homocysteine was significantly higher in the opium-addicted ones compared to non-addicted individuals (11.49 ± 7.45 vs. 8.02 ± 3.87 μmol/l) (P < 0.001). In this regard, 21.3% of the opium users and only 3.2% of the non-users had homocysteine concentration > 15 μmol/l (P < 0.001). On the other hand, individuals addicted to opiates exhibited significantly elevated odds of having homocysteine level higher than 15 [odds ratio (OR) = 8.244, 95% confidence interval (CI) = 3.117-21.806]. Multivariable linear regression model showed that the opium addiction could strongly predict elevated homocysteine level in the study individuals [beta = 3.524, standard error (SE) = 0.852] (P < 0.001). Conclusion Opium consumption can be strongly accompanied with the elevation of plasma homocysteine concentration, and thus opium addiction can exhibit elevated odds of having hyperhomocysteinemia. PMID:26885351

  19. Glibenclamide prevents increased extracellular matrix formation induced by high glucose concentration in mesangial cells.

    PubMed

    Giannico, Giovanna; Cortes, Pedro; Baccora, Mohammed H; Hassett, Clare; Taube, David W; Yee, Jerry

    2007-01-01

    Other than stimulation of cell contractility, little is known about the potential metabolic effects induced by sulfonylureas, independently of insulin action. Previous studies from our laboratory demonstrated complete abrogation of glomerulosclerosis in an experimental model of type 1 diabetes chronically (9 mo) treated with low-dose sulfonylureas (Biederman JI, Vera E, Pankhaniya R, Hassett C, Giannico G, Yee J, Cortes P. Kidney Int 67: 554-565, 2005). Therefore, the effects of glibenclamide (Glib) on net collagen I, collagen IV, and fibronectin medium net secretion and cell layer collagen I deposition were investigated in mesangial cells continuously exposed to 25 mM glucose for 8 wk and treated with predetermined increasing concentrations of Glib for the same period. Clinically relevant concentrations (0.01 microM) of Glib fully suppressed the high glucose-enhanced accumulation of collagen I, collagen IV, and fibronectin in the medium and inhibited collagen I deposition in the cell layer. These effects occurred while transforming growth factor (TGF)-beta1 medium concentration remained elevated and glucose uptake was increased to levels above those in 25 mM glucose-incubated cultures. The decreased collagen I accumulation occurred simultaneously with enhanced collagen I mRNA expression in concert with marked suppression of plasminogen inhibitor type-1 (PAI-1) mRNA and protein expression. This strongly suggests an accelerated matrix turnover favoring breakdown. Glib-induced effects demonstrated a biphasic pattern, being absent or reversed in cells treated with higher Glib concentrations (0.1 or 1 microM). Therefore, chronic Glib treatment at low concentrations markedly diminishes the high glucose-induced enhanced accumulation of extracellular matrix components by suppression of steady-state PAI-1 transcriptional activity. These results and those previously reported in vivo suggest that long-term Glib treatment may prevent glomerulosclerosis in insulin

  20. Detection of saliva-range glucose concentrations using organic thin-film transistors

    NASA Astrophysics Data System (ADS)

    Elkington, D.; Belcher, W. J.; Dastoor, P. C.; Zhou, X. J.

    2014-07-01

    We describe the development of a glucose sensor through direct incorporation of an enzyme (glucose oxidase) into the gate of an organic thin film transistor (OTFT). We show that glucose diffusion is the key determinant of the device response time and present a mechanism of glucose sensing in these devices that involves protonic doping of the transistor channel via enzymatic oxidation of glucose. The integrated OTFT sensor is sensitive across 4 decades of glucose concentration; a range that encompasses both the blood and salivary glucose concentration levels. As such, this work acts as a proof-of-concept for low-cost printed biosensors for salivary glucose.

  1. Detection of saliva-range glucose concentrations using organic thin-film transistors

    SciTech Connect

    Elkington, D.; Belcher, W. J.; Dastoor, P. C.; Zhou, X. J.

    2014-07-28

    We describe the development of a glucose sensor through direct incorporation of an enzyme (glucose oxidase) into the gate of an organic thin film transistor (OTFT). We show that glucose diffusion is the key determinant of the device response time and present a mechanism of glucose sensing in these devices that involves protonic doping of the transistor channel via enzymatic oxidation of glucose. The integrated OTFT sensor is sensitive across 4 decades of glucose concentration; a range that encompasses both the blood and salivary glucose concentration levels. As such, this work acts as a proof-of-concept for low-cost printed biosensors for salivary glucose.

  2. Vascular-dependent effects of elevated glucose on postganglionic sympathetic neurons.

    PubMed

    Damon, Deborah H

    2011-04-01

    Perivascular sympathetic nerves are important determinants of vascular function that are likely to contribute to vascular complications associated with hyperglycemia and diabetes. The present study tested the hypothesis that glucose modulates perivascular sympathetic nerves by studying the effects of 7 days of hyperglycemia on norepinephrine (NE) synthesis [tyrosine hydroxylase (TH)], release, and uptake. Direct and vascular-dependent effects were studied in vitro in neuronal and neurovascular cultures. Effects were also studied in vivo in rats made hyperglycemic (blood glucose >296 mg/dl) with streptozotocin (50 mg/kg). In neuronal cultures, TH and NE uptake measured in neurons grown in high glucose (HG; 25 mM) were less than that in neurons grown in low glucose (LG; 5 mM) (P < 0.05; n = 4 and 6, respectively). In neurovascular cultures, elevated glucose did not affect TH or NE uptake, but it increased NE release. Release from neurovascular cultures grown in HG (1.8 ± 0.2%; n = 5) was greater than that from cultures grown in LG (0.37 ± 0.28%; n = 5; P < 0.05; unpaired t-test). In vivo, elevated glucose did not affect TH or NE uptake, but it increased NE release. Release in hyperglycemic animals (9.4 + 1.1%; n = 6) was greater than that in control animals (5.39 + 1.1%; n = 6; P < 0.05; unpaired t-test). These data identify a novel vascular-dependent effect of elevated glucose on postganglionic sympathetic neurons that is likely to affect the function of perivascular sympathetic nerves and thereby affect vascular function.

  3. Adiponectin concentrations increase during acute FFA elevation in humans treated with rosiglitazone.

    PubMed

    Krzyzanowska, K; Mittermayer, F; Krugluger, W; Roden, M; Schernthaner, G; Wolzt, M

    2007-10-01

    The adipocytokine adiponectin is released by adipocytes upon activation of the peroxisome proliferator-activated receptor gamma (PPAR gamma). PPAR gamma has binding sites for thiazolidinediones and free fatty acids (FFAs). To evaluate if adiponectin serum concentrations are synergistically regulated by FFAs and thiazolidinediones IN VIVO plasma FFAs were acutely elevated in healthy subjects pre-treated with rosiglitazone or placebo. Sixteen healthy male subjects (23-37 years) were included in this double-blind, randomized, placebo-controlled parallel-group study. Rosiglitazone 8 mg or placebo was administered daily for 21 days. On the last day plasma FFA concentrations were increased by an intravenous triglyceride/heparin infusion. Blood for determination of adiponectin, C-reactive protein (CRP), leptin, resistin, FFAs, glucose, and insulin was drawn at baseline and on day 21 before and after 5 hours of triglyceride/heparin infusion. Adiponectin concentrations increased and FFA levels decreased in subjects receiving rosiglitazone (all p<0.05 VS. baseline). Lipid infusion significantly increased FFA plasma concentrations, with an attenuated elevation in rosiglitazone-treated subjects. However, adiponectin concentrations were only increased in subjects on rosiglitazone (p=0.018 VS. before lipid infusion), but not in controls. Leptin increased during lipid infusion in subjects receiving placebo but not in those on rosiglitazone. CRP and resistin were not affected by rosiglitazone or FFAs. The acute increase in circulating adiponectin concentrations during acutely elevated FFA depends on PPAR gamma activation in healthy subjects.

  4. Improving storage stability of gasoline using elevated antioxidant concentrations

    SciTech Connect

    Sommer, S.; Luria, D.; Lavie, I.; Sufrin, J.; Weiss, A.; Shuftan, M.

    1995-04-01

    The purpose of this study was to examine the feasibility of increasing storage-stability of gasoline by blending it with elevated concentrations of standard antioxidants, normally added at low concentrations to gasolines. It was thought that, by raising the concentration of these additives in the gasoline from 25 ppm to 100 ppm, the storage stability of the fuel can be improved. In this study, two types of antioxidants (an aromatic diamine type and an alkylphenol type), and a mixture of the two, were added at different concentrations to two different gasoline blends. The various blends were stored in drums, simulating tank storage conditions, for a period of 25 months. Samples were drawn at varying intervals over the test duration and tested for Existent Gum, Potential Gum, Induction Period and other properties (according to standard ASTM test procedures). It was found that raising the concentrations of the aromatic amine antioxidant adversely effected the storage stability of the gasoline blends, whereas elevated concentrations of the alkylphenol antioxidant indeed improved the gasoline`s stability.

  5. A Prospective Analysis of Elevated Fasting Glucose Levels and Cognitive Function in Older People

    PubMed Central

    Euser, Sjoerd M.; Sattar, Naveed; Witteman, Jacqueline C.M.; Bollen, Eduard L.E.M.; Sijbrands, Eric J.G.; Hofman, Albert; Perry, Ivan J.; Breteler, Monique M.B.; Westendorp, Rudi G.J.

    2010-01-01

    OBJECTIVE To investigate the relationship between fasting glucose levels, insulin resistance, and cognitive impairment in old age. Diabetes is associated with cognitive impairment in older people. However, the link between elevated fasting glucose levels and insulin resistance in nondiabetic individuals, and the risk of cognitive impairment is unclear. RESEARCH DESIGN AND METHODS We analyzed data from, in total, 8,447 participants in two independent prospective studies: the PROspective Study of Pravastatin in the Elderly at Risk (PROSPER), 5,019 participants, aged 69–84 years, and the Rotterdam Study, 3,428 participants, aged 61–97 years. Fasting glucose levels were assessed at baseline in both studies; fasting insulin levels were assessed in the Rotterdam Study only. Cognitive function was assessed in both studies at baseline and during follow-up. RESULTS Subjects with diabetes had impaired cognitive function at baseline. In contrast, in people without a history of diabetes, there was no clear association between baseline fasting glucose levels and executive function and memory, nor was there a consistent relationship between elevated baseline fasting glucose levels and the rate of cognitive decline in either cohort. Insulin resistance (homeostasis model assessment index) was also unrelated to cognitive function and decline. CONCLUSIONS Elevated fasting glucose levels and insulin resistance are not associated with worse cognitive function in older people without a history of diabetes. These data suggest either that there is a threshold for effects of dysglycemia on cognitive function or that factors other than hyperglycemia contribute to cognitive impairment in individuals with frank diabetes. PMID:20393152

  6. Effect of specific growth rate and glucose concentration on growth and glucose metabolism of Escherichia coli K-12.

    PubMed

    Hollywood, N; Doelle, H W

    1976-01-01

    Chemostat cultures of E. coli K-12 revealed that the metabolic change from respiration to aerobic fermentation can be obtained with increasing specific growth rate at low glucose input concentration (0.1%), or increasing glucose input concentrations at low specific growth rate (0.1 h-1). Both effects do not affect biomass formation. The metabolic change is not related to a pathway switch of glucose utilization. The increase in specific growth rate causes suppression of succinate dehydrogenase, and NADH oxidase, whereas glucose increases cause suppression of succinate dehydrogenase, cytochrome a and 2-ketoglutarate dehydrogenase. Both phenomena are reflected in the specific oxygen uptake rate, specific carbon dioxide production rate and respiratory quotient values. Growth limitation could be related to a maximal glucose uptake rate of the cell and thus constitutes an entirely different effect caused by high glucose input concentration.

  7. Elevated major ion concentrations inhibit larval mayfly growth and development.

    PubMed

    Johnson, Brent R; Weaver, Paul C; Nietch, Christopher T; Lazorchak, James M; Struewing, Katherine A; Funk, David H

    2015-01-01

    Anthropogenic disturbances, including those from developing energy resources, can alter stream chemistry significantly by elevating total dissolved solids. Field studies have indicated that mayflies (Order Ephemeroptera) are particularly sensitive to high total dissolved solids. In the present study, the authors measured 20-d growth and survivorship of larval Neocloeon triangulifer exposed to a gradient of brine salt (mixed NaCl and CaCl2 ) concentrations. Daily growth rates were reduced significantly in all salt concentrations above the control (363 µS cm(-1) ) and larvae in treatments with specific conductance >812 µS cm(-1) were in comparatively earlier developmental stages (instars) at the end of the experiment. Survivorship declined significantly when specific conductance was >1513 µS cm(-1) and the calculated 20-d 50% lethal concentration was 2866 µS cm(-1) . The present study's results provide strong experimental evidence that elevated ion concentrations similar to those observed in developing energy resources, such as oil and gas drilling or coal mining, can adversely affect sensitive aquatic insect species.

  8. Effects of Intraduodenal Administration of HCl and Glucose on Circulating Immunoreactive Secretin and Insulin Concentrations

    PubMed Central

    Boden, Guenther; Essa, Noorjehan; Owen, Oliver E.; Reichle, Frederick A.; Saraga, Walter

    1974-01-01

    A new radioimmunoassay for secretin was used to investigate (a) serum secretin responses to intraduodenally infused HCl and glucose, (b) the metabolic half-life and the volume of distribution of exogenous secretin and (c) the effect of endogenously released secretin on insulin secretion in 25 anesthetized dogs. Portal and femoral venous blood samples were taken simultaneously before, during, and after intraduodenal infusion of HCl (21 meq/30 min) and glucose (131 ml/30 min). Control experiments were performed with intraduodenal infusion of saline. Mean portal venous immunoreactive secretin concentration of six dogs rose from 313 μU/ml before to 1,060 μU/ml 10 min after initiation of the intestinal acidification (P < 0.005). Femoral venous immunoreactive secretin concentration rose from 220 μU/ml before to 567 μU/ml 15 min after intestinal acidification (P < 0.01). Secretin concentrations remained elevated during the remainder of the infusion. In the same six dogs mean portal venous immunoreactive insulin concentration rose from 38 μU/ml before to 62 μU/ml at the end of the infusion (P < 0.05). Peripheral immunoreactive insulin, glucose, and free fatty acid concentrations, however, did not change significantly. Pancreatic exocrine function was studied in four dogs. The rise in secretin concentration was followed promptly by a highly significant increase in exocrine pancreatic flow rate and bicarbonate secretion, indicating biological activity of the circulating immunoreactive secretin. The effect of intraduodenal infusion of glucose on immunoreactive secretin concentration was studied in 12 dogs. Glucose in concentrations ranging from 2.5% to 10% had no detectable influence on portal or peripheral secretin concentration. Infusion of 50% glucose caused a slight decline in secretin concentration. The metabolic clearance rate, half-life of disappearance, and volume of distribution of exogenous secretin was studied in three dogs by the constant infusion technic

  9. Genistein improves spatial learning and memory in male rats with elevated glucose level during memory consolidation.

    PubMed

    Kohara, Yumi; Kawaguchi, Shinichiro; Kuwahara, Rika; Uchida, Yutaro; Oku, Yushi; Yamashita, Kimihiro

    2015-03-01

    Cognitive dysfunction due to higher blood glucose level has been reported previously. Genistein (GEN) is a phytoestrogen that we hypothesized might lead to improved memory, despite elevated blood glucose levels at the time of memory consolidation. To investigate this hypothesis, we compared the effects of orally administered GEN on the central nervous system in normal versus glucose-loaded adult male rats. A battery of behavioral assessments was carried out. In the MAZE test, which measured spatial learning and memory, the time of normal rats was shortened by GEN treatment compared to the vehicle group, but only in the early stages of testing. In the glucose-loaded group, GEN treatment improved performance as mazes were advanced. In the open-field test, GEN treatment delayed habituation to the new environment in normal rats, and increased the exploratory behaviors of glucose-loaded rats. There were no significant differences observed for emotionality or fear-motivated learning and memory. Together, these results indicate that GEN treatment improved spatial learning and memory only in the early stages of testing in the normal state, but improved spatial learning and memory when glucose levels increased during memory consolidation. Copyright © 2014 Elsevier Inc. All rights reserved.

  10. Elevated fructosamine concentrations caused by IgA paraproteinemia in two dogs

    PubMed Central

    Kleiter, Miriam; Wolfesberger, Birgitt; Schwendenwein, Ilse; Miller, Ingrid

    2010-01-01

    An 8-year-old male Austrian Pinscher and a 14-year-old male Golden Retriever were presented for evaluation due to unexplainable high fructosamine values despite euglycemia and epistaxis in combination with polydipsia/polyuria, respectively. Blood analysis revealed severe hyperglobulinemia, hypoalbuminemia and markedly elevated fructosamine concentrations in both dogs. Multiple myeloma with IgA-monoclonal gammopathy was diagnosed by serum and urine electrophoresis including immunodetection with an anti-dog IgA antibody and bone marrow aspirations. Diabetes mellitus was excluded by repeated plasma and urine glucose measurements. Fructosamine values were positively correlated with globulin, but negatively correlated with albumin concentrations. These cases suggest that, as in human patients, monoclonal IgA gammopathy should be considered as a possible differential diagnosis for dogs with high fructosamine concentrations. PMID:21113108

  11. Measurement of glucose concentration in interstitial fluid by surface plasmon resonance with D-galactose/D-glucose binding protein

    NASA Astrophysics Data System (ADS)

    Li, D. C.; Zhang, J. X.; Wu, P.; Huang, F. X.; Song, B.; Xu, K. X.

    2009-08-01

    A novel minimally invasive way to measure blood glucose concentration is proposed by combining interstitial fluid transdermal extraction and surface plasma resonance (SPR) detecting. 55K Hz low-frequency ultrasound pulse is applied for less than 30 seconds to enhance the skin permeability and then interstitial fluid is extracted out of skin by vacuum. The mathematical model to express the correlation between interstitial fluid glucose and blood glucose is also developed by considering the changes of the skin conductivity. The glucose concentration in the interstitial fluid is determined using an optical SPR biological sensor that measures the refractive index. A protein-glucose binding technology using Dgalactose/ D-glucose Binding Protein for specific absorption of glucose is employed to increase SPR measurement precision. By immobilizing GGBP onto the surface of the SPR sensor, the experimental result indicates the detecting resolution of glucose rises to 1mg/L, the system succeeds in distinguishing glucose from other components in mixture. The feasibility of this method is validated for clinical application with the requirements of bloodless, painless, continuous glucose monitoring and a prototype microfluidic diabetes-monitoring device is under development.

  12. Surface contamination artificially elevates initial sweat mineral concentrations.

    PubMed

    Ely, Matthew R; Kenefick, Robert W; Cheuvront, Samuel N; Chinevere, Troy D; Lacher, Craig P; Lukaski, Henry C; Montain, Scott J

    2011-06-01

    Several sweat mineral element concentrations decline with serial sampling. Possible causes include reduced dermal mineral concentrations or flushing of surface contamination. The purpose of this study was to simultaneously sample mineral concentrations in transdermal fluid (TDF), sweat, and serum during extended exercise-heat stress to determine if these compartments show the same serial changes during repeat sampling. Sixteen heat-acclimated individuals walked on a treadmill (1.56 m/s, 3.0% grade) in a 35°C, 20% relative humidity (RH), 1 m/s wind environment 50 min each hour for 3 h. Mineral concentrations of Ca, Cu, Fe, K, Mg, Na, and Zn were measured each hour from serum, sweat from upper back (sweat pouch) and arm (bag), and TDF from the upper back. Sites were meticulously cleaned to minimize surface contamination. Mineral concentrations were determined by spectrometry. TDF remained stable over time, with exception of a modest increase in TDF [Fe] (15%) and decrease in TDF [Zn] (-18%). Likewise, serum and pouch sweat samples were stable over time. In contrast, the initial arm bag sweat mineral concentrations were greater than those in the sweat pouch, and [Ca], [Cu], [Mg], and [Zn] declined 26-76% from initial to the subsequent samples, becoming similar to sweat pouch. Nominal TDF mineral shifts do not affect sweat mineral concentrations. Arm bag sweat mineral concentrations are initially elevated due to skin surface contaminants that are not removed despite meticulous cleaning (e.g., under fingernails, on arm hair), then decrease with extended sweating and approach those measured from the scapular region.

  13. Olanzapine-induced changes in glucose metabolism are independent of the melanin-concentrating hormone system.

    PubMed

    Girault, Elodie M; Toonen, Pim W; Eggels, Leslie; Foppen, Ewout; Ackermans, Mariëtte T; la Fleur, Susanne E; Fliers, Eric; Kalsbeek, Andries

    2013-11-01

    Atypical antipsychotic drugs such as Olanzapine (Ola) induce weight gain and metabolic changes associated with the development of type 2 diabetes. The mechanisms underlying these undesired side-effects are currently unknown. Chagnon et al. showed that the common allele rs7973796 of the prepro-melanin-concentrating hormone (PMCH) gene is associated with a greater body mass index in Ola-treated schizophrenic patients. As PMCH encodes for the orexigenic neuropeptide melanin-concentrating hormone (MCH), it was hypothesized that MCH is involved in Ola-induced metabolic changes. We have recently reported that the intragastric infusion of Ola results in hyperglycaemia and insulin resistance in male rats. In order to test in vivo the possible involvement of the PMCH gene in the pathogenesis of Ola side-effects, we administered Ola intragastrically in wild-type (WT) and PMCH knock-out (KO) rats. Our results show that glucose and corticosterone levels, as well as endogenous glucose production, are elevated by the infusion of Ola in both WT and KO animals. Thus, the lack of MCH does not seem to affect the acute effects of Ola on glucose metabolism. On the other hand, these effects might be obliterated by compensatory changes in other hypothalamic systems. In addition, possible modulatory effects of the MCH KO on the long term effects of Ola, i.e. increased adiposity, body weight gain, have not been investigated yet.

  14. Apple leaf extract as a potential candidate for suppressing postprandial elevation of the blood glucose level.

    PubMed

    Shirosaki, Miyuki; Koyama, Tomoyuki; Yazawa, Kazunaga

    2012-01-01

    While the industrial value of fruits has long been recognized, only recently have the leaves of fruit trees been considered to have immense and mostly-untapped potential. In the present study, the physiological effects of apple leaf extract in mice were investigated. In addition, we sought to elucidate the active principle(s) and examined its potential for application. Apple leaf extract suppressed postprandial elevation of the blood glucose level and increased the residual amount of glucose in the small intestine in glucose-loaded mice compared with those in control mice. Bioassay-guided fractionation led to an active component that was identified as phloridzin, a known SGLT inhibitor, based on an analysis of its spectral data. With regard to an anti-hyperglycemic effect, extraction with ethanol from leaves of apple tree gave the best results. These effects decreased with heating during the extraction procedure. Since bolus ingestion of the extract did not affect blood glucose levels in normal mice with or without an overnight fast, the inhibitory effects on glucose absorption were not considered to be associated with unspecific gastrointestinal impairment and the extract did not cause hypoglycemia at a normally effective dose. Therefore, the leaf parts of apple tree may be a promising candidate as an industrial resource for maintaining good health in the future.

  15. Ketogenic diets and thermal pain: dissociation of hypoalgesia, elevated ketones, and lowered glucose in rats

    PubMed Central

    Ruskin, David N.; Suter, Tracey A.C.S.; Ross, Jessica L.; Masino, Susan A.

    2013-01-01

    Ketogenic diets are high-fat, low-carbohydrate formulations effective in treating medically-refractory epilepsy, and recently we demonstrated lowered sensitivity to thermal pain in rats fed a ketogenic diet for 3–4 weeks. Regarding anticonvulsant and hypoalgesic mechanisms, theories are divided as to direct effects of increased ketones and/or decreased glucose, metabolic hallmarks of these diets. To address this point, we characterized the time course of ketogenic diet-induced thermal hypoalgesia, ketosis, and lowered glucose in young male rats fed ad libitum on normal chow or ketogenic diets. A strict 6.6:1 (fat:(carbohydrates + protein), by weight), ketogenic diet increased blood ketones and reduced blood glucose by two days of feeding, but thermal hypoalgesia did not appear until 10 days. Thus, ketosis and decreased glucose are not sufficient for hypoalgesia. After feeding a 6.6:1 ketogenic diet for 19 days, decreased thermal pain sensitivity and changes in blood chemistry reversed one day after return to normal chow. Effects on were consistent between two different diet formulations: a more moderate and clinically-relevant ketogenic diet formula (3.0:1) produced hypoalgesia and similar changes in blood chemistry as the 6.6:1 diet, thus increasing translational potential. Furthermore, feeding the 3.0:1 diet throughout an extended protocol (10–11 weeks) revealed that significant hypoalgesia and increased ketones persisted whereas low glucose did not, demonstrating that ketogenic diet-induced hypoalgesia does not depend on reduced glucose. In separate experiments we determined that effects on thermal pain responses were not secondary to motor or cognitive changes. Together, these findings dissociate diet-related changes in nociception from direct actions of elevated ketones or decreased glucose, and suggest mechanisms with a slower onset in this paradigm. Overall, our data indicate that metabolic approaches can relieve pain. PMID:23499319

  16. A study on detection of glucose concentration using changes in color coordinates.

    PubMed

    Kim, Ji-Sun; Oh, Han-Byeol; Kim, A-Hee; Kim, Jun-Sik; Lee, Eun-Suk; Baek, Jin-Young; Lee, Ki Sung; Chung, Soon-Cheol; Jun, Jae-Hoon

    2017-01-02

    Glucose concentration is closely related to the metabolic activity of cells and it is the most important substance as the energy source of a living body which plays an important role in the human body. This paper proposes an optical method that can measure the concentration of glucose. The change in glucose concentration was observed by using CIE diagram, and wavelength and purity values were detected. Also, even small changes in glucose concentration can be evaluated through mathematical modeling. This system is simple, economical, and capable of quantifying optical signals with numerical values for glucose sensing. This method can be applicable to the clinical field that examines diabetes mellitus or metabolic syndrome.

  17. Alteration of Oceanic Nitrification Under Elevated Carbon Dioxide Concentrations

    NASA Astrophysics Data System (ADS)

    Beman, J.; Chow, C. E.; Popp, B. N.; Fuhrman, J. A.; Feng, Y.; Hutchins, D. A.

    2008-12-01

    Atmospheric carbon dioxide (CO2) concentrations are increasing exponentially and expected to double by the year 2100. Dissolution of excess CO2 in the upper ocean reduces pH, alters carbonate chemistry, and also represents a potential resource for autotrophic organisms that convert inorganic carbon into biomass--including a broad spectrum of marine microbes. These bacteria and archaea drive global biogeochemical cycles of carbon and nitrogen and constitute the vast majority of biomass in the sea, yet their responses to reduced pH and increased pCO2 remain largely undocumented. Here we show that elevated pCO2 may sharply reduce nitrification rates and populations of nitrifying microorganisms in the ocean. Multiple experiments were performed in the Sargasso Sea and the Southern California Bight under glacial maximum (193 ppm), present day (390 ppm), and projected (750 ppm) pCO2 concentrations, over time scales from hours to multiple days, and at depths of 45 m to 240 m. Measurement of nitrification rates using isotopically-labeled nitrogen showed 2-5 fold reduction under elevated pCO2--as well as an increase under glacial maximum pCO2. Marine Crenarchaeota are likely involved in nitrification as ammonia-oxidizing archaea (AOA) and are among the most abundant microbial groups in the ocean, yet this group decreased by 40-80% under increased pCO2, based on quantification of both 16S rRNA and ammonia monooxygenase (amoA) gene copies. Crenarchaeota also steadily declined over the course of multiple days under elevated pCO2, whereas ammonia-oxidizing (AOB) and nitrite-oxidizing bacteria (NOB) were more variable in their responses or were not detected. These findings suggest that projected increases in pCO2 and subsequent decreases in pH may strongly influence marine biogeochemistry and microbial community structure in the sea.

  18. [Home monitoring of blood glucose concentrations by owners of diabetic dogs and cats].

    PubMed

    Sieber-Ruckstuhl, N S; Casella, M; Reusch, C E

    2003-11-01

    Generation of blood glucose curves is essential to monitor glycemic control in dogs and cats with diabetes mellitus. Up till now blood collection and blood glucose measurements could only be performed in a hospital. However, glucose concentrations measured in a hospital environment can markedly differ from concentrations measured at home, due to reduced appetite, different activity level and stressful handling. At the Clinic of Small Animal Internal Medicine, University of Zurich, a new method to collect capillary blood from the ear and to measure blood glucose by means of a portable glucose meter has been developed. This method enables owners of diabetic dogs or cats to determine blood glucose concentrations and generate blood glucose curves at home. Three cases demonstrate, how much blood glucose concentrations at home may differ from those in the hospital and how home monitoring can help to establish diabetic control in dogs and cats.

  19. Effects of alcohol abstinence on glucose metabolism in Japanese men with elevated fasting glucose: A pilot study

    PubMed Central

    Funayama, Takashi; Tamura, Yoshifumi; Takeno, Kageumi; Kawaguchi, Minako; Kakehi, Saori; Watanabe, Takahiro; Furukawa, Yasuhiko; Kaga, Hideyoshi; Yamamoto, Risako; Kanazawa, Akio; Fujitani, Yoshio; Kawamori, Ryuzo; Watada, Hirotaka

    2017-01-01

    It has been demonstrated that moderate alcohol consumption provides protection against the development of type 2 diabetes. However, several other reports suggested that moderate alcohol intake may increase the risk of type 2 diabetes in non-obese Japanese. The aim of present study was to investigate the effect of 1-week alcohol abstinence on hepatic insulin sensitivity and fasting plasma glucose (FPG) in non-obese Japanese men. We recruited 8 non-obese Japanese men with mildly elevated FPG and drinking habits alcohol (mean frequency; 5.6 ± 2.5 times/week, mean alcohol consumption; 32.1 ± 20.0 g/day). Before and after the 1-week alcohol abstinence, we used the 2-step hyperinsulinemic-euglycemic clamp to measure endogenous glucose production (EGP) and insulin sensitivity (IS) in muscle and liver. One-week alcohol abstinence significantly reduced both FPG by 7% (from 105.5 ± 11.7 to 98.2 ± 7.8 mg/dl, P < 0.01) and fasting EGP by 6% (from 84.1 ± 4.2 to 77.6 ± 1.6 mg/m2 per min, P < 0.01), respectively. Two–step clamp study showed that alcohol abstinence significantly improved hepatic-IS, but not muscle-IS. In conclusion, one week alcohol abstinence improved hepatic IS and FPG in non-obese Japanese men with mildly elevated FPG and drinking habits alcohol. PMID:28067302

  20. Latinas with Elevated Fasting Plasma Glucose: An Analysis Using NHANES 2009–2010 Data

    PubMed Central

    Strauss, Shiela M.; Vega, Marlena; Clayton-Jeter, Helene D.; Deren, Sherry; Rosedale, Mary; Rindskopf, David M.

    2017-01-01

    For Latinas with fasting plasma glucose (FPG) levels in the pre-diabetes and diabetes ranges, early detection can support steps to optimize their health. Data collected in 2009–2010 indicate that 36.7% of Latinas in the U.S. had elevated FPG levels. Latinas with elevated FPG who were unaware of their diabetes status were significantly less likely than non-Hispanic White and non-Hispanic Black women to have seen a health care provider in the past year (75.8%, 92.9%, and 90.2%, respectively; p = .018). With almost 1 million Latinas in the U.S. with elevated FPG unaware of their diabetes risk, and less likely than other at-risk women to see health care providers, there is an urgent need to establish alternate sites of opportunity for their diabetes screening. PMID:24865436

  1. Elevated Carbon Dioxide Concentration Reduces Alarm Signaling in Aphids.

    PubMed

    Boullis, Antoine; Fassotte, Bérénice; Sarles, Landry; Lognay, Georges; Heuskin, Stéphanie; Vanderplanck, Maryse; Bartram, Stefan; Haubruge, Eric; Francis, Frédéric; Verheggen, François J

    2017-02-01

    Insects often rely on olfaction to communicate with conspecifics. While the chemical language of insects has been deciphered in recent decades, few studies have assessed how changes in atmospheric greenhouse gas concentrations might impact pheromonal communication in insects. Here, we hypothesize that changes in the concentration of atmospheric carbon dioxide affect the whole dynamics of alarm signaling in aphids, including: (1) the production of the active compound (E)-β-farnesene (Eβf), (2) emission behavior when under attack, (3) perception by the olfactory apparatus, and (4) the escape response. We reared two strains of the pea aphid, Acyrthosiphon pisum, under ambient and elevated CO2 concentrations over several generations. We found that an increase in CO2 concentration reduced the production (i.e., individual content) and emission (released under predation events) of Eβf. While no difference in Eβf neuronal perception was observed, we found that an increase in CO2 strongly reduced the escape behavior expressed by an aphid colony following exposure to natural doses of alarm pheromone. In conclusion, our results confirm that changes to greenhouse gases impact chemical communication in the pea aphid, and could potentially have a cascade effect on interactions with higher trophic levels.

  2. Development of a fluorescent method for simultaneous measurement of glucose concentrations in interstitial fluid and blood

    NASA Astrophysics Data System (ADS)

    Shi, Ting; Li, Dachao; Li, Guoqing; Chen, Limin; Lin, Yuan; Xu, Kexin; Lu, Luo

    2013-12-01

    Continuous blood glucose monitoring is of great clinical significance to patients with diabetes. One of the effective methods to monitor blood glucose is to measure glucose concentrations of interstitial fluid (ISF). However, a time-delay problem exists between ISF and blood glucose concentrations, which results in difficulty in indicating real-time blood glucose concentrations. Therefore, we developed a fluorescent method to verify the accuracy and reliability of simultaneous ISF and blood glucose measurement, especially incorporating it into research on the delay relationship between blood and ISF glucose changes. This method is based on a competitive reaction among borate polymer, alizarin and glucose. When glucose molecules combine with borate polymers in alizarin-borate polymer competitively, changes in fluorescence intensity demonstrate changes in glucose concentrations. By applying the measured results to the blood and ISF glucose delay relationship, we were able to calculate the time delay as an average of 2.16 ± 2.05 min for ISF glucose changes with reference to blood glucose concentrations.

  3. Gremlin gene expression in bovine retinal pericytes exposed to elevated glucose.

    PubMed

    Kane, R; Stevenson, L; Godson, C; Stitt, A W; O'Brien, C

    2005-12-01

    To assess the influence of high extracellular glucose on the expression of the bone morphogenetic protein (BMP) antagonist, gremlin, in cultured bovine retinal pericytes (BRPC). BRPC were cultured under conditions of 5 mM and 30 mM d-glucose for 7 days and total RNA was isolated. Gremlin mRNA levels were correlated, by RT-PCR, with other genes implicated in the pathogenesis of diabetic retinopathy and the signalling pathways in high glucose induced gremlin expression were probed using physiological inhibitors. Gremlin expression was also examined in the retina of streptozotocin induced diabetic mice. High glucose stimulated a striking increase in BRPC gremlin mRNA levels in parallel with increases in mRNA for the growth factors vascular endothelial growth factor (VEGF), transforming growth factor beta (TGFbeta), and connective tissue growth factor (CTGF) and changes in other genes including fibronectin and plasminogen activator inhibitor-1 (PAI-1). High glucose triggered gremlin expression was modulated by anti-TGFbeta antibody, by the uncoupler of oxidative phosphorylation, CCCP, and by inhibition of MAP-kinase (MAPK) activation. Striking gremlin expression was observed in the outer retina of diabetic mice and also at the level of the vascular wall. Gremlin gene expression is induced in BRPC in response to elevated glucose and in the retina of the streptozotocin induced diabetic mouse. Its expression is modulated by hyperglycaemic induction of the MAPK, reactive oxygen species, and TGFbeta pathways, all of which are reported to have a role in diabetic fibrotic disease. This implicates a role for gremlin in the pathogenesis of diabetic retinopathy.

  4. Gremlin gene expression in bovine retinal pericytes exposed to elevated glucose

    PubMed Central

    Kane, R; Stevenson, L; Godson, C; Stitt, A W; O’Brien, C

    2005-01-01

    Aim: To assess the influence of high extracellular glucose on the expression of the bone morphogenetic protein (BMP) antagonist, gremlin, in cultured bovine retinal pericytes (BRPC). Methods: BRPC were cultured under conditions of 5 mM and 30 mM d-glucose for 7 days and total RNA was isolated. Gremlin mRNA levels were correlated, by RT-PCR, with other genes implicated in the pathogenesis of diabetic retinopathy and the signalling pathways in high glucose induced gremlin expression were probed using physiological inhibitors. Gremlin expression was also examined in the retina of streptozotocin induced diabetic mice. Results: High glucose stimulated a striking increase in BRPC gremlin mRNA levels in parallel with increases in mRNA for the growth factors vascular endothelial growth factor (VEGF), transforming growth factor β (TGFβ), and connective tissue growth factor (CTGF) and changes in other genes including fibronectin and plasminogen activator inhibitor-1 (PAI-1). High glucose triggered gremlin expression was modulated by anti-TGFβ antibody, by the uncoupler of oxidative phosphorylation, CCCP, and by inhibition of MAP-kinase (MAPK) activation. Striking gremlin expression was observed in the outer retina of diabetic mice and also at the level of the vascular wall. Conclusions: Gremlin gene expression is induced in BRPC in response to elevated glucose and in the retina of the streptozotocin induced diabetic mouse. Its expression is modulated by hyperglycaemic induction of the MAPK, reactive oxygen species, and TGFβ pathways, all of which are reported to have a role in diabetic fibrotic disease. This implicates a role for gremlin in the pathogenesis of diabetic retinopathy. PMID:16299147

  5. Experimental and natural warming elevates mercury concentrations in estuarine fish.

    PubMed

    Dijkstra, Jennifer A; Buckman, Kate L; Ward, Darren; Evans, David W; Dionne, Michele; Chen, Celia Y

    2013-01-01

    Marine food webs are the most important link between the global contaminant, methylmercury (MeHg), and human exposure through consumption of seafood. Warming temperatures may increase human exposure to MeHg, a potent neurotoxin, by increasing MeHg production as well as bioaccumulation and trophic transfer through marine food webs. Studies of the effects of temperature on MeHg bioaccumulation are rare and no study has specifically related temperature to MeHg fate by linking laboratory experiments with natural field manipulations in coastal ecosystems. We performed laboratory and field experiments on MeHg accumulation under varying temperature regimes using the killifish, Fundulus heteroclitus. Temperature treatments were established in salt pools on a coastal salt marsh using a natural temperature gradient where killifish fed on natural food sources. Temperatures were manipulated across a wider range in laboratory experiments with killifish exposed to MeHg enriched food. In both laboratory microcosms and field mesocosms, MeHg concentrations in killifish significantly increased at elevated temperatures. Moreover, in field experiments, other ancillary variables (salinity, MeHg in sediment, etc.) did not relate to MeHg bioaccumulation. Modeling of laboratory experimental results suggested increases in metabolic rate as a driving factor. The elevated temperatures we tested are consistent with predicted trends in climate warming, and indicate that in the absence of confounding factors, warmer sea surface temperatures could result in greater in bioaccumulation of MeHg in fish, and consequently, increased human exposure.

  6. Experimental and Natural Warming Elevates Mercury Concentrations in Estuarine Fish

    PubMed Central

    Dijkstra, Jennifer A.; Buckman, Kate L.; Ward, Darren; Evans, David W.; Dionne, Michele; Chen, Celia Y.

    2013-01-01

    Marine food webs are the most important link between the global contaminant, methylmercury (MeHg), and human exposure through consumption of seafood. Warming temperatures may increase human exposure to MeHg, a potent neurotoxin, by increasing MeHg production as well as bioaccumulation and trophic transfer through marine food webs. Studies of the effects of temperature on MeHg bioaccumulation are rare and no study has specifically related temperature to MeHg fate by linking laboratory experiments with natural field manipulations in coastal ecosystems. We performed laboratory and field experiments on MeHg accumulation under varying temperature regimes using the killifish, Fundulus heteroclitus. Temperature treatments were established in salt pools on a coastal salt marsh using a natural temperature gradient where killifish fed on natural food sources. Temperatures were manipulated across a wider range in laboratory experiments with killifish exposed to MeHg enriched food. In both laboratory microcosms and field mesocosms, MeHg concentrations in killifish significantly increased at elevated temperatures. Moreover, in field experiments, other ancillary variables (salinity, MeHg in sediment, etc.) did not relate to MeHg bioaccumulation. Modeling of laboratory experimental results suggested increases in metabolic rate as a driving factor. The elevated temperatures we tested are consistent with predicted trends in climate warming, and indicate that in the absence of confounding factors, warmer sea surface temperatures could result in greater in bioaccumulation of MeHg in fish, and consequently, increased human exposure. PMID:23554891

  7. Engineered Kluyveromyces marxianus for pyruvate production at elevated temperature with simultaneous consumption of xylose and glucose.

    PubMed

    Zhang, Biao; Zhu, Yelin; Zhang, Jia; Wang, Dongmei; Sun, Lianhong; Hong, Jiong

    2017-01-01

    Xylose and glucose from lignocellulose are sustainable sources for production of pyruvate, which is the starting material for the synthesis of many drugs and agrochemicals. In this study, the pyruvate decarboxylase gene (KmPDC1) and glycerol-3-phosphate dehydrogenase gene (KmGPD1) of Kluyveromyces marxianus YZJ051 were disrupted to prevent ethanol and glycerol accumulation. The deficient growth of PDC disruption was rescued by overexpressing mutant KmMTH1-ΔT. Then pentose phosphate pathway and xylitol dehydrogenase SsXYL2-ARS genes were overexpressed to obtain strain YZB053 which produced pyruvate with xylose other than glucose. It produced 24.62g/L pyruvate from 80g/L xylose with productivity of 0.51g/L/h at 42°C. Then, xylose-specific transporter ScGAL2-N376F was overexpressed to obtain strain YZB058, which simultaneously consumed 40g/L glucose and 20g/L xylose and produced 29.21g/L pyruvate with productivity of 0.81g/L/h at 42°C. Therefore, a platform for pyruvate production from glucose and xylose at elevated temperature was developed.

  8. Exposure to low levels of hydrogen sulfide elevates circulating glucose in maternal rats

    SciTech Connect

    Hayden, L.J.; Goeden, H.; Roth, S.H. )

    1990-09-01

    Although the lethal effect of hydrogen sulfide (H{sub 2}S) has long been known, the results of exposure to low levels of H{sub 2}S have not been well documented. Rat dams and pups were exposed to low levels of H{sub 2}S (less than or equal to 75 ppm) from d 1 of gestation until d 21 postpartum and analyzed for changes in circulating enzymatic activity and metabolites. Blood glucose was significantly elevated in maternal blood on d 21 postpartum at all exposure levels. This increase in glucose was accompanied by a possible decrease in serum triglyceride in the pups and in the dams on d 21 postpartum. There was no evidence of alterations in serum alkaline phosphatase, lactate dehydrogenase, or serum glutamate oxaloacetate transaminase.

  9. Ketogenic diets and thermal pain: dissociation of hypoalgesia, elevated ketones, and lowered glucose in rats.

    PubMed

    Ruskin, David N; Suter, Tracey A C S; Ross, Jessica L; Masino, Susan A

    2013-05-01

    Ketogenic diets (KDs) are high-fat, low-carbohydrate formulations effective in treating medically refractory epilepsy, and recently we demonstrated lowered sensitivity to thermal pain in rats fed a KD for 3 to 4 weeks. Regarding anticonvulsant and hypoalgesic mechanisms, theories are divided as to direct effects of increased ketones and/or decreased glucose, metabolic hallmarks of these diets. To address this point, we characterized the time course of KD-induced thermal hypoalgesia, ketosis, and lowered glucose in young male rats fed ad libitum on normal chow or KDs. A strict 6.6:1 (fat:[carbohydrates + protein], by weight) KD increased blood ketones and reduced blood glucose by 2 days of feeding, but thermal hypoalgesia did not appear until 10 days. Thus, ketosis and decreased glucose are not sufficient for hypoalgesia. After feeding a 6.6:1 KD for 19 days, decreased thermal pain sensitivity and changes in blood chemistry reversed 1 day after return to normal chow. Effects were consistent between 2 different diet formulations: a more moderate and clinically relevant KD formula (3.0:1) produced hypoalgesia and similar changes in blood chemistry as the 6.6:1 diet, thus increasing translational potential. Furthermore, feeding the 3.0:1 diet throughout an extended protocol (10-11 weeks) revealed that significant hypoalgesia and increased ketones persisted whereas low glucose did not, demonstrating that KD-induced hypoalgesia does not depend on reduced glucose. In separate experiments we determined that effects on thermal pain responses were not secondary to motor or cognitive changes. Together, these findings dissociate diet-related changes in nociception from direct actions of elevated ketones or decreased glucose, and suggest mechanisms with a slower onset in this paradigm. Overall, our data indicate that metabolic approaches can relieve pain. Chronic pain is a common and debilitating condition. We show that a KD, a high-fat, very low carbohydrate diet well known

  10. The Importance of Different Frequency Bands in Predicting Subcutaneous Glucose Concentration in Type 1 Diabetic Patients

    DTIC Science & Technology

    2010-02-01

    Maran, A. Facchinetti, and C. Cobelli, ―Glucose concentration can be predicted ahead in time from continuous glucose monitoring sensor time-series...Polonsky, ―Circadian modulation of glucose and insulin responses to meals: relationship to cortisol rhythm,‖ Am. J. Physiol. Endocrinol. Metab., vol

  11. Glucose concentrations in blood and tissue - a pilot study on variable time lag.

    PubMed

    Chlup, Rudolf; Krejci, Jan; O'Connell, Mark; Sebestova, Blanka; Plicka, Robert; Jezova, Lucie; Brozova, Tereza; Doubravova, Blanka; Zalesakova, Hana; Durajkova, Emilia; Vojtek, Jiri; Bartek, Josef

    2015-12-01

    The aim of this pilot study was to acquire insight into the parameters of glycaemic control, especially, (1) the time delay (lag phase) between plasma and tissue glucose concentrations in relation to rise and fall in glucose levels and (2) the rate of glucose increase and decrease. Four healthy people (HP), 4 people with type 1diabetes (DM1) and 4 with type 2 diabetes (DM2) underwent concurrent glucose measurements by means of (1) the continuous glucose monitoring system (CGMS-Medtronic), Medtronic-Minimed, CA, USA, calibrated by the glucometer Calla, Wellion, Austria, and, (2) the Beckman II analyser to measure glucose concentrations in venous plasma. Samples were taken on 4 consecutive days in the fasting state and 4 times after consumption of 50 g glucose. Carelink Personal, MS Excel, Maple and Mat lab were applied to plot the evolution of glucose concentration and analyse the results. The time difference between increase and decrease was calculated for HP, DM 1 and DM 2. In DM1and DM2, glucose tolerance testing (GTT) resulted in slower transport of glucose into subcutaneous tissue than in HP where the lag phase lasted up to 12 min. The maximum increase/decrease rates in DM1 and DM2 vs HP were 0.25 vs < 0.1 mmol/L/min. CGMS is shown to provide reliable plasma glucose concentrations provided the system is calibrated during a steady state. The analysis of glucose change rates improves understanding of metabolic processes better than standard GTT.

  12. Aggregation ability of erythrocytes of patients with coronary heart disease depending on different glucose concentration

    NASA Astrophysics Data System (ADS)

    Malinova, Lidia I.; Simonenko, Georgy V.; Kirichuk, Vyacheslav F.; Denisova, Tatyana P.; Tuchin, Valery V.

    2002-07-01

    The aggregation ability of erythrocytes of patients with coronary heart disease comparing to practically healthy persons and patients with coronary heart disease combined with non insulin dependent diabetes mellitus depending on different glucose concentration in unguentums of blood incubates with the help of computer microphotometer - visual analyzer was studied. Two-phase behavior of erythrocytes size changing of practically healthy persons depending on glucose concentration in an incubation medium and instability erythrocyte systems of a whole blood to the influence of high glucose concentration were revealed. Influence of high glucose concentration on aggregation ability of erythrocytes of patients with coronary heart disease and its combination with non insulin dependent diabetes mellitus was revealed.

  13. Fetal glucose uptake and utilization as functions of maternal glucose concentration.

    PubMed

    Hay, W W; Sparks, J W; Wilkening, R B; Battaglia, F C; Meschia, G

    1984-03-01

    Seventeen studies were performed in 12 pregnant sheep to examine the relationship among simultaneously measured glucose uptake via the umbilical circulation, fetal glucose utilization (mg X min-1 X kg-1), and maternal arterial glucose (Gm, mg/dl). Fetal glucose utilization was measured by means of tracer glucose infused into the fetus or both mother and fetus. By fasting the ewe, Gm was varied in the 62-22 range. A decrease in Gm was accompanied by a significant (P less than 0.001) decrease in umbilical uptake (uptake = 0.09 Gm - 0.96, r = 0.82) and in fetal utilization, measured either by [U-14C]glucose (utilization = 0.062 Gm + 0.91, r = 0.90) or [6-3H]glucose (utilization = 0.065 Gm + 0.51, r = 0.91). At uptake greater than 3 mg X min-1 X kg-1, utilization and uptake were not significantly different. At lower uptakes, utilization did not decline as much as uptake. The results demonstrate that maternal fasting decreases both the umbilical uptake and the fetal utilization of glucose and suggest that fetal glucogenesis increases when the availability of exogenous glucose is markedly reduced.

  14. [Hypoglycaemic coma due to falsely elevated glucose values in a patient with diabetes mellitus and peritoneal dialysis].

    PubMed

    Nienhuis, W A; Bruijns, R H J; Vastenburg, G; Wouters, R S M E

    2006-07-15

    A 45-year-old female diabetes-mellitus patient on peritoneal dialysis was admitted because of vertigo. During her stay in hospital she developed a comatose condition with abnormal head posture and deviation ofthe eyes to the left. Capillary blood from the fingertip showed a glucose value of 15.4 mmol/l. However, the automatically obtained glucose value delivered with a blood-gas analysis was found to be 1.2 mmol/l. The neurological state of the patient normalised fully after intravenous glucose administration. The glucose values were falsely elevated because the patient used a peritoneal dialysis fluid at night which contained icodextrin as an osmotic agent. Metabolites of icodextrin can influence blood-glucose measurements taken using analyzers that depend on the enzyme glucose dehydrogenase. To prevent potentially life-threatening situations, the use of an adequate glucose meter is of paramount importance.

  15. Effects of prolonged elevation of plasma adrenaline concentration in vivo on insulin-sensitivity in soleus muscle of the rat.

    PubMed Central

    Budohoski, L; Challiss, R A; Dubaniewicz, A; Kaciuba-Usciłko, H; Leighton, B; Lozeman, F J; Nazar, K; Newsholme, E A; Porta, S

    1987-01-01

    1. Prolonged elevation of the plasma adrenaline concentration was produced in rats by implantation of adrenaline-releasing retard-tablets. With this technique, a hyperadrenalinaemic state is maintained for at least 5 days. 2. At 6 h after implantation of the retard-tablet it was found that plasma glucose and fatty acid concentrations increased and insulin concentration decreased compared with values obtained from placebo-tablet-implanted rats. Administration of a subcutaneous glucose load demonstrated an impaired glucose tolerance in vivo, and incubation of soleus muscle strips from 6 h-hyperadrenalinaemic rats in vitro demonstrated a decreased sensitivity of the rates of glycolysis and glucose transport to insulin. 3. The sensitivities of the rates of glycolysis, glucose transport and glycogen synthesis to insulin were determined for the incubated soleus muscle preparation isolated from animals after 48 h, 72 h and 120 h duration of hyperadrenalinaemia. At 48 h after retard-tablet implantation, the sensitivity of the processes of glucose transport and glycolysis was decreased; at 72 h, the insulin-sensitivities of the rates of glycolysis and glucose transport in skeletal muscle were similar to those determined for control animals; at 120 h, however, the sensitivities of the processes of glucose transport and glycolysis were both statistically significantly increased. In contrast, no changes in the sensitivity of the process of glycogen synthesis were observed at any of the time intervals studied. 4. The possible biochemical basis for the observed changes in skeletal-muscle insulin-sensitivity with prolonged hyperadrenalinaemia is discussed. PMID:3328612

  16. Performance of two portable meters and a benchtop analyzer for blood glucose concentration measurement in rabbits.

    PubMed

    Selleri, Paolo; Di Girolamo, Nicola; Novari, Gianluca

    2014-07-01

    To evaluate performance of a human portable blood glucose meter (PBGM), a veterinary PBGM, and a veterinary benchtop analyzer for measuring blood glucose concentration in rabbits and to evaluate the effect of sample characteristics on their performance. Observational prospective cross-sectional study. Blood samples from 89 pet rabbits. Blood glucose concentration was measured with a human PBGM (n = 89 rabbits), a veterinary PBGM (89), and a benchtop analyzer (32) and compared with results obtained with plasma in a laboratory analyzer (hexokinase method). The human PBGM underestimated blood glucose concentration, had decreased accuracy at high Hcts, and had the lowest total error observed (11.4%). The veterinary PBGM overestimated blood glucose concentration, had decreased accuracy at low Hcts and at high blood glucose concentrations, and had the highest total error (15.5% and 29.8% for canine and feline settings, respectively). The benchtop analyzer had good accuracy and was not influenced by Hct or glucose concentrations. Clinical errors would have occurred in 0% of cases with the human PBGM and with the benchtop analyzer and in 9% (canine setting) to 6.7% (feline setting) of cases with the veterinary PBGM. Results suggested that use of the human PBGM evaluated in this study would be acceptable for point-of-care testing of blood glucose concentration in rabbits when benchtop analyzers are not available. The use of the veterinary PBGM evaluated in this study may alter both treatment and diagnostic decisions because of the overestimation of glucose concentrations in some rabbits.

  17. Mechanism by which an elevation of extracellular glucide concentration induces pigment aggregation in medaka melanophores.

    PubMed

    Fujii, Ryozo; Goda, Makoto; Oshima, Noriko

    2002-09-15

    An increase in glucide concentration induces pigment aggregation in melanophores in the skin on scales isolated from the medaka, Oryzias latipes. In this study, hexoses (including the common D-isomers of glucose, galactose, fructose, and mannitol) were examined. Denervated melanophores were refractory to such stimuli. An alpha-adrenolytic agent, phentolamine, effectively blocked the responses of normally innervated melanophores. The pigment-aggregating action of glucide was inhibited by withdrawal of Ca(2+) and Mg(2+) ions from the medium. A specific blocker of voltage-dependent N-type Ca(2+) channels, the omega-conotoxin GVIA, also inhibited the glucide action. The conclusion derived is that an elevation of glucide levels acts to open Ca(2+) channels of presynaptic membranes of sympathetic postganglionic fibers, and the consequently released adrenergic transmitter acts on the effector cells to induce the aggregation of their pigmentary organelles. Copyright 2002 Wiley-Liss, Inc.

  18. Astrocyte-elevated gene-1 (AEG-1) induction by hypoxia and glucose deprivation in glioblastoma.

    PubMed

    Noch, Evan; Bookland, Markus; Khalili, Kamel

    2011-01-01

    Glioblastomas continue to carry poor prognoses for patients despite advances in surgical, chemotherapeutic, and radiation regimens. One feature of glioblastoma associated with poor prognosis is the degree of hypoxia and expression levels of hypoxia-inducible factor-1 α (HIF-1α). HIF-1α expression allows metabolic adaptation to low oxygen availability, partly through upregulation of VEGF and increased tumor angiogenesis. Here, we demonstrate an induced level of astrocyte-elevated gene-1 (AEG-1) by hypoxia in glioblastoma cells. AEG-1 has the capacity to promote anchorage-independent growth and cooperates with Ha-ras in malignant transformation. In addition, AEG-1 was recently demonstrated to serve as an oncogene and can induce angiogenesis in glioblastoma. Results from in vitro studies show that hypoxic induction of AEG-1 is dependent on HIF-1α stabilization during hypoxia and that PI3K inhibition abrogates AEG-1 induction during hypoxia through loss of HIF-1α stability. Furthermore, we show that AEG-1 is induced by glucose deprivation and that prevention of intracellular reactive oxygen species (ROS) production prevents this induction. Additionally, AEG-1 knockdown results in increased ROS production and increased glucose deprivation-induced cytotoxicity. On the other hand, AEG-1 overexpression prevents ROS production and decreases glucose deprivation-induced cytotoxicity, indicating that AEG-1 induction is necessary for cells to survive this type of cell stress. These observations link AEG-1 overexpression in glioblastoma with hypoxia and glucose deprivation, and targeting these physiological pathways may lead to therapeutic advances in the treatment of glioblastoma in the future.

  19. High D(+)glucose concentration inhibits RANKL-induced osteoclastogenesis

    PubMed Central

    Wittrant, Y; Gorin, Y; Woodruff, K; Horn, D; Abboud, HE; Mohan, S; Abboud-Werner, SL

    2009-01-01

    Diabetes is a chronic disease associated with hyperglycemia and altered bone metabolism that may lead to complications including osteopenia, increased risk of fracture and osteoporosis. Hyperglycemia has been implicated in the pathogenesis of diabetic bone disease; however, the biologic effect of glucose on osteoclastogenesis is unclear. In the present study, we examined the effect of high D(+)glucose (D-Glc) and L(−)glucose (L-Glc; osmotic control) on RANKL-induced osteoclastogenesis using RAW264.7 cells and Bone Marrow Macrophages (BMM) as models. Cells were exposed to sustained high glucose levels to mimic diabetic conditions. Osteoclast formation was analyzed using tartrate resistant acid phosphatase (TRACP) assay, expression of calcitonin receptor (CTR) and cathepsin K mRNAs, and cultures were examined for reactive oxygen species (ROS) using dichlorodihydrofluorescein diacetate (DCF-DA) fluorescence, caspase-3 and Nuclear Factor kappaB (NF-κB) activity. Cellular function was assessed using a migration assay. Results show, for the first time, that high D-Glc inhibits osteoclast formation, ROS production, caspase-3 activity and migration in response to RANKL through a metabolic pathway. Our findings also suggest that high D-Glc may alter RANKL-induced osteoclast formation by inhibiting redox-sensitive NF-κB activity through an anti-oxidative mechanism. This study increases our understanding of the role of glucose in diabetes-associated bone disease. Our data suggest that high glucose levels may alter bone turnover by decreasing osteoclast differentiation and function in diabetes and provide new insight into the biologic effects of glucose on osteoclastogenesis. PMID:18378205

  20. Manifestations of diabetes mellitus on mouse preimplantation development: effect of elevated concentration of metabolic intermediates.

    PubMed

    Moley, K H; Vaughn, W K; Diamond, M P

    1994-01-01

    The metabolic derangements of pregnancies complicated by diabetes mellitus, specifically hyperglycaemia and hyperketonaemia, are known to be teratogenic during the period of organogenesis in animals. We have shown previously that poorly controlled diabetes mellitus impairs in-vivo and in-vitro mouse preimplantation embryo growth, and that culturing embryos in elevated glucose concentrations only partially recreates this developmental delay. To extend this observation we examined the effect on mouse preimplantation embryo growth of elevated concentrations of other metabolic intermediates, which may be deranged in diabetes mellitus, namely lipids, lactate, glycerol, amino acids, and ketones. Two-cell embryos from ovulation-induced B6C3F1 mice were cultured for 72 h in the presence of added lipids (250 mg/dl), lactate (5 mM), glycerol (160 microM) or mixed amino acids (8.5% travasol, 7 mM) and showed no significant difference in growth over 72 h versus their control groups. However, growth of preimplantation embryos in acetoacetate (10 mM) or in the racemic mixture of DL-beta-hydroxybutyrate (16 and 32 mM) revealed marked retardation versus controls when assessed either by distribution of developmental stages over time (24, 48, 72 h, P < 0.001) or by the difference in the average rank of sums indicating a delay in maturation (P < 0.0001). We conclude that elevated ketone concentrations adversely affect preimplantation embryo development. These findings extend previous studies which correlate uncontrolled diabetes mellitus as well as hyperglycaemia with abnormal organogenesis, and demonstrate that exposure to metabolic derangements may also hinder reproductive performance at even earlier stages in gestation.

  1. Pioglitazone acutely reduces insulin secretion and causes metabolic deceleration of the pancreatic beta-cell at submaximal glucose concentrations.

    PubMed

    Lamontagne, Julien; Pepin, Emilie; Peyot, Marie-Line; Joly, Erik; Ruderman, Neil B; Poitout, Vincent; Madiraju, S R Murthy; Nolan, Christopher J; Prentki, Marc

    2009-08-01

    Thiazolidinediones (TZDs) have beneficial effects on glucose homeostasis via enhancement of insulin sensitivity and preservation of beta-cell function. How TZDs preserve beta-cells is uncertain, but it might involve direct effects via both peroxisome proliferator-activated receptor-gamma-dependent and -independent pathways. To gain insight into the independent pathway(s), we assessed the effects of short-term (glucose-induced insulin secretion (GIIS), AMP-activated protein kinase (AMPK) activation, and beta-cell metabolism in INS 832/13 beta-cells and rat islets. Pio caused a right shift in the dose-dependence of GIIS, such that insulin release was reduced at intermediate glucose but unaffected at either basal or maximal glucose concentrations. This was associated in INS 832/13 cells with alterations in energy metabolism, characterized by reduced glucose oxidation, mitochondrial membrane polarization, and ATP levels. Pio caused AMPK phosphorylation and its action on GIIS was reversed by the AMPK inhibitor compound C. Pio also reduced palmitate esterification into complex lipids and inhibited lipolysis. As for insulin secretion, the alterations in beta-cell metabolic processes were mostly alleviated at elevated glucose. Similarly, the antidiabetic agents and AMPK activators metformin and berberine caused a right shift in the dose dependence of GIIS. In conclusion, Pio acutely reduces glucose oxidation, energy metabolism, and glycerolipid/fatty acid cycling of the beta-cell at intermediate glucose concentrations. We suggest that AMPK activation and the metabolic deceleration of the beta-cell caused by Pio contribute to its known effects to reduce hyperinsulinemia and preserve beta-cell function and act as an antidiabetic agent.

  2. Salivary glucose concentration exhibits threshold kinetics in normal-weight, overweight, and obese children.

    PubMed

    Hartman, Mor-Li; Goodson, J Max; Barake, Roula; Alsmadi, Osama; Al-Mutawa, Sabiha; Ariga, Jitendra; Soparkar, Pramod; Behbehani, Jawad; Behbehani, Kazem; Welty, Francine

    2015-01-01

    Metabolic syndrome in childhood predicts the development of cardiovascular disease and type 2 diabetes (T2D) in adulthood. Testing for features of metabolic syndrome, such as fasting plasma glucose concentration, requires blood sampling which can be difficult in children. Here we evaluated salivary glucose concentration as a surrogate measurement for plasma glucose concentration in 11-year-old US children. Children from Portland, Maine, and Cambridge, Massachusetts, with a mean age of 10.6±0.2 years provided 6-hour fasting samples of both blood and whole saliva. Salivary glucose levels were measured with a high-sensitivity assay (sensitivity =0.002 mg/dL). Plasma glucose levels were determined by a commercial clinical laboratory. Blood pressure, salivary flow rate, height, and weight were also measured. Of the 65 children enrolled, there were two underweight children (3.1%), 30 normal-weight children (46.2%), 12 overweight children (18.4%), and 21 obese children (32.3%). The mean overall glucose concentrations were 0.11±0.02 mg/dL in saliva and 86.3±0.8 mg/dL in plasma, and these did not differ significantly by body-weight groups. By regression analysis, the plasma concentration equaled 13.5 times the saliva concentration, with a threshold level of 84.8 mg/dL. Salivary glucose values less than threshold plasma concentration were essentially zero. Diagnostic analysis indicated a positive predictive value of 50%, a negative predictive value of 90%, and a sensitivity and specificity both of approximately 75%. The salivary glucose concentration did not vary with saliva flow rate. Taking into account the threshold response characteristics of the salivary glucose concentration response, these results suggest that testing salivary glucose levels may be useful as a screening assay for high fasting plasma glucose levels. The low false positive value is important to assure a low fraction of missed diagnoses.

  3. Evaluation of blood glucose concentration measurement using photoacoustic spectroscopy in near-infrared region

    NASA Astrophysics Data System (ADS)

    Namita, Takeshi; Sato, Mitsuki; Kondo, Kengo; Yamakawa, Makoto; Shiina, Tsuyoshi

    2017-03-01

    Diabetes, a typical lifestyle-related disease, is an important disease presenting risks of various complications such as retinopathy, kidney failure, and nervous neuropathy. To treat diabetes, regular and continual self-measurement of blood glucose concentrations is necessary to maintain blood glucose levels and to prevent complications. Usually, daily measurements are taken using invasive methods such as finger-prick blood sampling. Some non-invasive optical techniques have been proposed to reduce pain and infection risk, however, few practical techniques exist today. To realize highly accurate and practical measurement of blood glucose concentrations, the feasibility of a photoacoustic method using near-infrared light was evaluated. A photoacoustic signal from a solution of glucose in water (+0-5 g/dl) or equine blood (+0-400 mg/dl) was measured using a hydrophone (9 mm diameter) at 800-1800 nm wavelengths. We investigated the relation between the glucose solution concentration and the photoacoustic signal intensity or peak position of the received photoacoustic signal (i.e. speed of sound in solutions). Results show that the signal intensity and sound speed of the glucose solution increase with increased glucose concentration for wavelengths at which light absorbance of glucose is high. For quantitative estimation of the glucose solution concentration, the photoacoustic signal intensity ratio between two wavelengths, at which dependence of the signal intensity on glucose concentration is high and low, was calculated. Results confirmed that the signal intensity ratios increase linearly with the glucose concentration. These analyses verified the feasibility of glucose level estimation using photoacoustic measurement in the near-infrared region.

  4. ELEVATED CO2 AND ELEVATED TEMPERATURE AFFECT CARBON AND NITROGEN CONCENTRATIONS BUT NOT ACCUMULATION IN PSEUDOTSUGA MENZIESII SEEDLINGS

    EPA Science Inventory

    To determine the impact of climate change on concentrations and accumulation of C and N in trees, we grew Pseudotsuga menziesii (Mirb.) Franco (Douglas-fir) seedlings treated with ambient or elevated (+180 mol mol-1) CO2, and with ambient or elevated (+3.5 C) temperature for f...

  5. ELEVATED CO2 AND ELEVATED TEMPERATURE AFFECT CARBON AND NITROGEN CONCENTRATIONS BUT NOT ACCUMULATION IN PSEUDOTSUGA MENZIESII SEEDLINGS

    EPA Science Inventory

    To determine the impact of climate change on concentrations and accumulation of C and N in trees, we grew Pseudotsuga menziesii (Mirb.) Franco (Douglas-fir) seedlings treated with ambient or elevated (+180 mol mol-1) CO2, and with ambient or elevated (+3.5 C) temperature for f...

  6. Relationship between glucose oxidation and FFA concentration in septic cancer-bearing patients

    SciTech Connect

    Sauerwein, H.P.; Pesola, G.R.; Groeger, J.S.; Jeevanandam, M.; Brennan, M.F.

    1988-11-01

    Glucose oxidation is inhibited in severely ill patients. The present investigation was designed to study the relationship between glucose tissue uptake, glucose oxidation, and FFA concentration in septic cancer-bearing patients. The influence of glucose infusion alone (3.9 mg x kg-1 x min-1), followed by a euglycemic clamp with the same glucose load, on oxidation of glucose, plasma FFA concentration, and lipid oxidation were measured in eight septic cancer-bearing patients. During infusion of 3.9 mg glucose x kg-1 x min-1 glucose tissue uptake was 4.6 +/- 0.3 mg x kg-1 x min-1, glucose oxidation 0.5 +/- 0.2 mg x kg-1 x min-1, FFA concentration 377 +/- 52 mumol x L-1, and lipid oxidation 2.0 +/- 0.2 mumol x kg-1 x min-1. During the euglycemic clamp glucose tissue uptake was 4.4 +/- 0.3 mg x kg-1 x min-1, glucose oxidation rose to 1.8 mg x kg-1 x min-1 (.001 less than P less than .01), FFA concentration dropped to 202 +/- 23 mumol x L-1 (P less than .001), and lipid oxidation to 1.2 +/- 0.2 mumol x kg-1 x min-1 (.001 less than P less than .01). Nonprotein respiratory quotient rose from 0.73 +/- 0.02 to 0.85 +/- 0.02 (.001 less than P less than .01); 11% +/- 5% of the total amount of glucose taken up by the tissues was oxidized during infusion of glucose alone and increased to 42% +/- 6% during the euglycemic glucose clamp. It is concluded that in septic cancer-bearing patients glucose oxidation is inhibited during infusion of 3.9 mg glucose x kg-1 x min-1, even when expressed as percentage of glucose tissue uptake. With insulin, glucose tissue uptake was not influenced, but glucose oxidation expressed as percentage of glucose tissue uptake was normalized.

  7. Application of transcutaneous diffuse reflectance spectroscopy in the measurement of blood glucose concentration

    NASA Astrophysics Data System (ADS)

    Chen, Wenliang; Liu, Rong; Cui, Houxin; Xu, Kexin; Lv, Lina

    2004-07-01

    In this paper, the propagation characteristics of near-infrared (NIR) light in the palm tissue are analyzed, and the principle and feasibility of using transcutaneous diffuse reflectance spectroscopy for non-invasive blood glucose detection are presented. An optical probe suitable for measuring the diffuse reflectance spectrum of human palm and a non-invasive blood glucose detection system using NIR spectroscopy are designed. Based on this system, oral glucose tolerance tests are performed to measure the blood glucose concentrations of two young healthy volunteers. The partial least square calibration model is then constructed by all individual experimental data. The final result shows that correlation coefficients of the two experiments between the predicted blood glucose concentrations and the reference blood glucose concentrations are 0.9870 and 0.9854, respectively. The root mean square errors of prediction of full cross validation are 0.54 and 0.52 mmol/l, respectively.

  8. Erroneously elevated glucose values due to maltose interference in mutant glucose dehydrogenase pyrroloquinolinequinone (mutant GDH-PQQ) based glucometer.

    PubMed

    Chakraborty, Partha Pratim; Patra, Shinjan; Bhattacharjee, Rana; Chowdhury, Subhankar

    2017-05-12

    Currently available glucose test strip enzymes include glucose oxidase (GOD) and glucose dehydrogenase (GDH). In GDH-based glucometers, glucose oxidation can be catalysed by different cofactors: nicotinamide adenine dinucleotide (GDH-NAD), flavin adenine dinucleotide (GDH-FAD), pyrroloquinolinequinone (GDH-PQQ) and mutant GDH-PQQ. GOD-based and GDH-NAD-based glucometers are substrate-specific and do not react with sugars other than glucose. GDH-FAD reacts with xylose only in addition to glucose. GDH-PQQ is not glucose-specific; in addition to glucose, it reacts with different other sugars and produces falsely high values of capillary glucose in the presence of such substances. There are reports of several deaths associated with usage of GDH-PQQ-based test strips. A modified form of GDH-PQQ, the so-called mutant GDH-PQQ, is supposedly free from such interferences. In this article spuriously high glucose values due to maltose interference in a glucometer using the mutant GDH-PQQ chemistry are being reported. © BMJ Publishing Group Ltd (unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  9. High concentrations of glucose reduce the oxidative metabolism of dog neutrophils in vitro

    PubMed Central

    2013-01-01

    Background Dogs are commonly affected by hyperglycemic conditions. Hyperglycemia compromises the immune response and favors bacterial infections; however, reports on the effects of glucose on neutrophil oxidative metabolism and apoptosis are conflicting in humans and rare in dogs. Considering the many complex factors that affect neutrophil oxidative metabolism in vivo, we investigated in vitro the specific effect of high concentrations of glucose on superoxide production and apoptosis rate in neutrophils from healthy dogs. Results The capacity of the neutrophils to reduce tetrazolium nitroblue decreased significantly in the higher concentration of glucose (15.13 ± 9.73% (8 mmol/L) versus 8.93 ± 5.71% (16 mmol/L)). However, there were no changes in tetrazolium nitroblue reduction at different glucose concentrations when the neutrophils were first activated with phorbol myristate acetate. High concentrations of glucose did not affect the viability and apoptosis rate of canine neutrophils either with or without prior camptothecin stimulation. This study provides the first evidence that high concentrations of glucose inhibit the oxidative metabolism of canine neutrophils in vitro in a manner similar to that which occurs in humans, and that the decrease in superoxide production did not increase the apoptosis rate. Conclusions A high concentration of glucose reduces the oxidative metabolism of canine neutrophils in vitro. It is likely that glucose at high concentrations rapidly affects membrane receptors responsible for the activation of NADPH oxidase in neutrophils; therefore, the nonspecific immune response can be compromised in dogs with acute and chronic hyperglycemic conditions. PMID:23388121

  10. Preliminary validation of an exercise program suitable for pregnant women with abnormal glucose metabolism: inhibitory effects of Tai Chi Yuttari-exercise on plasma glucose elevation

    PubMed Central

    Yamamoto, Sachina; Kagawa, Kyoko; Hori, Naohi; Akezaki, Yoshiteru; Mori, Kohei; Nomura, Takuo

    2016-01-01

    [Purpose] There is insufficient evidence related to exercise programs that are safe and efficacious for pregnant women with abnormal glucose metabolism. Tai Chi Yuttari-exercise is an exercise program with validated safety and efficacy in improving physical function in the elderly. In this study, we investigated this program’s inhibitory effects on plasma glucose elevation when it was adapted to a pregnancy model. [Subjects and Methods] Twelve 18- to 19-year-old females without a history of pregnancy were randomly assorted into two groups: an intervention group, for which six subjects were outfitted with mock-pregnancy suits and asked to perform Tai Chi Yuttari-exercise, and a control group who did not perform exercise. The intervention group had a mean Borg Scale score of 11.1 ± 0.9 during the exercise. [Results] No significant intragroup differences were observed in fasting, baseline, or post-intervention/observation plasma glucose levels. On the other hand, the intergroup change in plasma glucose levels after intervention/observation was significant when comparing the intervention and control groups: −1.66 ± 7.0 and 9.42 ± 6.57 mg/dl, respectively. [Conclusion] Tai Chi Yuttari-exercise appears to effectively inhibit plasma glucose elevation at intensity and movement levels that can be safely applied to pregnant women with abnormal glucose metabolism. PMID:28174463

  11. Measurement of the glucose concentration in human urine with optical refractometer

    NASA Astrophysics Data System (ADS)

    Wu, Rui-Yang; Hsu, Cheng-Chih; Meng, Ching-Tang; Cheng, Chih-Ching; Liao, Yu-Ching

    2015-07-01

    In this paper, a new type of human urine glucose measurement system is proposed. We measured the phase variation of human urine with/without glucose-urine mixture (to simulate diabetes mellitus). We were able to achieve high resolution with the proposed method. The relation curve between the phase difference and glucose concentration can be estimated, and the glucose concentration of a urine sample can be determined by using this relation curve. The proposed method showed that theoretical resolution is approximated of 1.47 mg/dl.

  12. Glucose uptake and transport in contracting, perfused rat muscle with different pre-contraction glycogen concentrations.

    PubMed Central

    Hespel, P; Richter, E A

    1990-01-01

    1. Glucose uptake and transport, muscle glycogen, free glucose and glucose-6-phosphate concentrations were studied in perfused resting and contracting rat skeletal muscle with different pre-contraction glycogen concentrations. Rats were pre-conditioned by a combination of swimming exercise and diet, resulting in either low (glycogen-depleted rats), normal (control rats) or high (supercompensated rats) muscle glycogen concentrations at the time their hindlimbs were perfused. 2. Compared with control rats, pre-contraction muscle glycogen concentration was approximately 40% lower in glycogen-depleted rats, whereas it was 40% higher in supercompensated rats. Muscle glycogen break-down correlated positively (r = 0.76; P less than 0.001) with pre-contraction muscle glycogen concentration. 3. Glucose uptake during contractions was approximately 50% higher in glycogen-depleted hindquarters than in control hindquarters; in supercompensated hindquarters it was 30% lower. When rats with similar muscle glycogen concentrations were compared, glucose uptake in hindquarters from rats that had exercised on the preceding day was approximately 20% higher than in hindquarters from rats that had not exercised on the preceding day. 4. Muscle membrane glucose transport, as measured by the rate of accumulation of 14C-3-O-methylglucose in the contracting muscles, was 25% lower in supercompensated than in glycogen-depleted muscles at the onset as well as at the end of the 15 min contraction period. 5. Intracellular concentrations of free glucose and glucose-6-phosphate were higher at rest and during the entire 15-min stimulation period in supercompensated muscles than in glycogen-depleted muscles, and glucose uptake during contractions correlated negatively with free glucose (r = -0.52; P less than 0.01) as well as with glucose-6-phosphate (r = -0.49; P less than 0.01) concentrations. 6. It is concluded that: (a) The rate of glucose uptake in contracting skeletal muscle is dependent on the

  13. Surface contamination artificially elevates initial sweat mineral concentrations

    USDA-ARS?s Scientific Manuscript database

    During exercise in the heat, sweat is initially concentrated in minerals, but serial sweat samples appear more dilute. Possible causes include reduced dermal mineral concentrations or flushing of surface contamination. PURPOSE: To simultaneously sample mineral concentrations in transdermal fluid (T...

  14. Highly sensitive detection of glucose concentration with opto-fluidics ring resonator

    NASA Astrophysics Data System (ADS)

    Luo, Yunhan; Khaing Oo, Maung Kyaw; Ge, Jia; Chen, Zhe; Fan, Xudong

    2012-06-01

    Noninvasive detection of glucose has been heavily researched in their roles of offering cost-effective, painless, and bloodless monitoring of glucose concentration. In this work, we describe a novel, label-free, and sensitive approach for detecting the glucose concentration in human interstitial fluid samples using the opto-fluidic ring resonator (OFRR). The OFRR incorporates microfluidics and optical ring resonator sensing technology to achieve rapid label-free detection in a small and low-cost platform. In this study, bulk refractive index measurements are presented. Results show that the OFRR is able to detect glucose at medically relevant concentrations in interstitial fluid ranging from 0 to 25 mM, with a detection limit of 0.32 mM, which is lower than clinical requirement by one order of magnitude. Our work is believed to lead to a device that can be used to frequently monitor glucose concentration in a low-cost and painless manner.

  15. Measurement of glucose concentration by image processing of thin film slides

    NASA Astrophysics Data System (ADS)

    Piramanayagam, Sankaranaryanan; Saber, Eli; Heavner, David

    2012-02-01

    Measurement of glucose concentration is important for diagnosis and treatment of diabetes mellitus and other medical conditions. This paper describes a novel image-processing based approach for measuring glucose concentration. A fluid drop (patient sample) is placed on a thin film slide. Glucose, present in the sample, reacts with reagents on the slide to produce a color dye. The color intensity of the dye formed varies with glucose at different concentration levels. Current methods use spectrophotometry to determine the glucose level of the sample. Our proposed algorithm uses an image of the slide, captured at a specific wavelength, to automatically determine glucose concentration. The algorithm consists of two phases: training and testing. Training datasets consist of images at different concentration levels. The dye-occupied image region is first segmented using a Hough based technique and then an intensity based feature is calculated from the segmented region. Subsequently, a mathematical model that describes a relationship between the generated feature values and the given concentrations is obtained. During testing, the dye region of a test slide image is segmented followed by feature extraction. These two initial steps are similar to those done in training. However, in the final step, the algorithm uses the model (feature vs. concentration) obtained from the training and feature generated from test image to predict the unknown concentration. The performance of the image-based analysis was compared with that of a standard glucose analyzer.

  16. Coupling glucose fermentation and homoacetogenesis for elevated acetate production: Experimental and mathematical approaches.

    PubMed

    Ni, Bing-Jie; Liu, He; Nie, Yan-Qiu; Zeng, Raymond J; Du, Guo-Cheng; Chen, Jian; Yu, Han-Qing

    2011-02-01

    Homoacetogenesis is an important potential hydrogen sink in acetogenesis, in which hydrogen is used to reduce carbon dioxide to acetate. So far the acetate production from homoacetogenesis, especially its kinetics, has not been given sufficient attention. In this work, enhanced production of acetate from anaerobic conversion of glucose through coupling glucose fermentation and homoacetogenesis is investigated with both experimental and mathematical approaches. Experiments are conducted to explore elevated acetate production in a coupled anaerobic system. Acetate production could be achieved by homoacetogenesis with a relative high acetate yield under mixed fermentation conditions. With the experimental observations, a kinetic model is formulated to describe such a homoacetogenic process. The maximum homoacetogenic rate (k(m,homo)) is estimated to be 28.5 ± 1.7 kg COD kg⁻¹ COD day⁻¹ with an uptake affinity constant of 3.7 × 10⁻⁵± 3.1 × 10⁻⁶kg COD m⁻³. The improved calculation of homoacetogenic kinetics by our approach could correct the underestimation of homoacetogenesis in anaerobic fermentation processes, as it often occurs in these systems supported by literature analysis. The model predictions match the experimental results in different cases well and provide insights into the dynamics of anaerobic glucose conversion and acetate production. Furthermore, acetate production via homoacetogenesis increases by about 40% through utilizing the fed-batch coupling system, attributed to a balance between the hydrogen production in the acetogenesis phase and the hydrogen consumption in the homoacetogenesis phase. This work provides an effective way for increased anaerobic acetate production, and gives us a better understanding about the homoacetogenic kinetics in the anaerobic fermentation process. © 2010 Wiley Periodicals, Inc.

  17. Disruption of glucose homeostasis and induction of insulin resistance by elevated free fatty acids in human L02 hepatocytes.

    PubMed

    Wan, X-D; Yang, W-B; Xia, Y-Z; Wang, J-F; Lu, T; Wang, X-M

    2009-05-01

    Free fatty acids (FFA) have been implicated as an important causative link between obesity, insulin resistance, and Type 2 diabetes. However, the underlying mechanisms especially for FFA-mediated hepatic insulin resistance are not fully elucidated. Here, we investigated the impaired sites in insulin signaling pathways and mechanisms of insulin resistance induced by elevated FFA in L02 hepatocytes. L02 cells were cultured in Dulbecco's modified eagle medium containing various concentrations of palmitic acid (PA) for 24 h followed by 10(-7) mol/l insulin stimulation. In some experiments, cells were pre-treated with enzymatic inhibitor Wortmannin (10(-6) mol/l). Glucose levels in medium, cytosolic glycogen contents, and phosphoenolpyruvate carboxykinase (PEPCK) activity were measured. Protein level of insulin receptor substrate (IRS)-2 and phosphorylated Akt were detected by Western blot analysis. L02 cells treated with high levels of PA exhibited increased glucose levels, whereas hepatic glycogen contents were decreased in a dose-dependent manner as compared to the control cells. There was a significant attenuation of IRS- 2 protein expression in the cells cultured with PA, and Wortmannin intervention exhibited different IRS-2 protein level with or without PA treatment. In accordance with the reduced IRS-2 level, the insulin-stimulated phosphorylation of Akt was diminished in the PA-treated cells. Basal PEPCK activity and insulin- regulated PEPCK activity were overstimulated in the cells incubated with PA. These data indicate high levels of FFA can disrupt glucose homeostasis, inflict some defects in insulin signaling, and induce insulin resistance in L02 cells.

  18. Peripheral Blood Transcriptomic Signatures of Fasting Glucose and Insulin Concentrations.

    PubMed

    Chen, Brian H; Hivert, Marie-France; Peters, Marjolein J; Pilling, Luke C; Hogan, John D; Pham, Lisa M; Harries, Lorna W; Fox, Caroline S; Bandinelli, Stefania; Dehghan, Abbas; Hernandez, Dena G; Hofman, Albert; Hong, Jaeyoung; Joehanes, Roby; Johnson, Andrew D; Munson, Peter J; Rybin, Denis V; Singleton, Andrew B; Uitterlinden, André G; Ying, Saixia; Melzer, David; Levy, Daniel; van Meurs, Joyce B J; Ferrucci, Luigi; Florez, Jose C; Dupuis, Josée; Meigs, James B; Kolaczyk, Eric D

    2016-12-01

    Genome-wide association studies (GWAS) have successfully identified genetic loci associated with glycemic traits. However, characterizing the functional significance of these loci has proven challenging. We sought to gain insights into the regulation of fasting insulin and fasting glucose through the use of gene expression microarray data from peripheral blood samples of participants without diabetes in the Framingham Heart Study (FHS) (n = 5,056), the Rotterdam Study (RS) (n = 723), and the InCHIANTI Study (Invecchiare in Chianti) (n = 595). Using a false discovery rate q <0.05, we identified three transcripts associated with fasting glucose and 433 transcripts associated with fasting insulin levels after adjusting for age, sex, technical covariates, and complete blood cell counts. Among the findings, circulating IGF2BP2 transcript levels were positively associated with fasting insulin in both the FHS and RS. Using 1000 Genomes-imputed genotype data, we identified 47,587 cis-expression quantitative trait loci (eQTL) and 6,695 trans-eQTL associated with the 433 significant insulin-associated transcripts. Of note, we identified a trans-eQTL (rs592423), where the A allele was associated with higher IGF2BP2 levels and with fasting insulin in an independent genetic meta-analysis comprised of 50,823 individuals. We conclude that integration of genomic and transcriptomic data implicate circulating IGF2BP2 mRNA levels associated with glucose and insulin homeostasis. © 2016 by the American Diabetes Association.

  19. Differential Mueller matrix polarimetry technique for non-invasive measurement of glucose concentration on human fingertip.

    PubMed

    Phan, Quoc-Hung; Lo, Yu-Lung

    2017-06-26

    A differential Mueller matrix polarimetry technique is proposed for obtaining non-invasive (NI) measurements of the glucose concentration on the human fingertip. The feasibility of the proposed method is demonstrated by detecting the optical rotation angle and depolarization index of tissue phantom samples containing de-ionized water (DI), glucose solutions with concentrations ranging from 0~500 mg/dL and 2% lipofundin. The results show that the extracted optical rotation angle increases linearly with an increasing glucose concentration, while the depolarization index decreases. The practical applicability of the proposed method is demonstrated by measuring the optical rotation angle and depolarization index properties of the human fingertips of healthy volunteers.

  20. Photonic crystal based biosensor for the detection of glucose concentration in urine

    NASA Astrophysics Data System (ADS)

    Robinson, Savarimuthu; Dhanlaksmi, Nagaraj

    2017-03-01

    Photonic sensing technology is a new and accurate measurement technology for bio-sensing applications. In this paper, a two-dimensional photonic crystal ring resonator based sensor is proposed and designed to detect the glucose concentration in urine over the range of 0 gm/dl-15 gm/dl. The proposed sensor is consisted of two inverted "L" waveguides and a ring resonator. If the glucose concentration in urine is varied, the refractive index of the urine is varied, which in turn the output response of sensor will be varied. By having the aforementioned principle, the glucose concentration in urine, glucose concentration in blood, albumin, urea, and bilirubin concentration in urine are predicted. The size of the proposed sensor is about 11.4 µm×11.4 µm, and the sensor can predict the result very accurately without any delay, hence, this attempt could be implemented for medical applications.

  1. Photonic crystal based biosensor for the detection of glucose concentration in urine

    NASA Astrophysics Data System (ADS)

    Robinson, Savarimuthu; Dhanlaksmi, Nagaraj

    2016-10-01

    Photonic sensing technology is a new and accurate measurement technology for bio-sensing applications. In this paper, a two-dimensional photonic crystal ring resonator based sensor is proposed and designed to detect the glucose concentration in urine over the range of 0 gm/dl-15 gm/dl. The proposed sensor is consisted of two inverted "L" waveguides and a ring resonator. If the glucose concentration in urine is varied, the refractive index of the urine is varied, which in turn the output response of sensor will be varied. By having the aforementioned principle, the glucose concentration in urine, glucose concentration in blood, albumin, urea, and bilirubin concentration in urine are predicted. The size of the proposed sensor is about 11.4 µm×11.4 µm, and the sensor can predict the result very accurately without any delay, hence, this attempt could be implemented for medical applications.

  2. Production of glucose syrups in highly concentrated systems.

    PubMed

    van der Veen, M E; van der Goot, A J; Boom, R M

    2005-01-01

    We have investigated the hydrolysis of maltodextrins in a high concentration (up to 70%), by means of enzymatic and acid catalysis. The study revealed that the equilibrium compositions of the catalyzed reactions were kinetically determined by the selectivity of the catalyst, the substrate concentration and the reaction time. A model comprising a set of two kinetic equations was used to describe the hydrolysis and condensation reactions of glucoamylase-catalyzed reactions, even to highly concentrated systems. Increased substrate concentration resulted in the formation of more condensation products. The enzyme inhibition was low and was found to be independent of the substrate concentration.

  3. First obtaining of glass solutions and phase diagram of glucose with fully tunable anomeric concentration.

    PubMed

    Dujardin, N; Willart, J F; Dudognon, E; Danède, F; Descamps, M

    2010-03-01

    In this article we show the possibility to form amorphous alpha-glucose/beta-glucose molecular alloys directly in the solid state by comilling crystalline alpha-glucose and crystalline beta-glucose. Contrary to the usual melt quenching process, milling does not induce any mutarotation so that alloys can be obtained for the whole range of anomeric concentration. This offers the unique possibility to explore the phase diagram of this binary system which appears to be a eutectic mixture. The structural and thermodynamic investigations have been performed by powder X-ray diffraction and differential scanning calorimetry. 2009 Wiley-Liss, Inc. and the American Pharmacists Association

  4. Acute effects of concentric and eccentric exercise on glucose metabolism and interleukin-6 concentration in healthy males

    PubMed Central

    Krüsmann, PJ; Mersa, L; Eder, EM; Gatterer, H; Melmer, A; Ebenbichler, C; Burtscher, M

    2016-01-01

    Acute muscle-damaging eccentric exercise (EE) negatively affects glucose metabolism. On the other hand, long-term eccentric endurance exercise seems to result in equal or superior positive effects on glucose metabolism compared to concentric endurance exercise. However, it is not known if acute non-muscle-damaging EE will have the same positive effects on glucose metabolism as acute concentric exercise (CE). Interleukin-6 (IL-6) released from the exercising muscles may be involved in the acute adaptations of glucose metabolism after CE and non-muscle-damaging EE. The aim of this study was to assess acute effects of uphill walking (CE) and non-muscle-damaging downhill walking (EE) on glucose metabolism and IL-6 secretion. Seven sedentary non-smoking, healthy males participated in a crossover trial consisting of a 1 h uphill (CE) and a 1 h downhill (EE) walking block on a treadmill. Venous blood samples were drawn before (pre), directly after (acute) and 24 h after (post) exercise. An oral glucose tolerance test (OGTT) was performed before and 24 h after exercise. Glucose tolerance after 1 and 2 hours significantly improved 24 hours after CE (-10.12±3.22%: P=0.039; -13.40±8.24%: P=0.028). After EE only the 1-hour value was improved (-5.03±5.48%: P=0.043). Acute IL-6 concentration rose significantly after CE but not after EE. We conclude that both a single bout of CE and a single bout of non-muscle-damaging EE elicit positive changes in glucose tolerance even in young, healthy subjects. Our experiment indicates that the overall metabolic cost is a major trigger for acute adaptations of glucose tolerance after exercise, but only the IL-6 production during EE was closely related to changes in glycaemic control. PMID:27274108

  5. Measurement of tissue optical properties with optical coherence tomography: Implication for noninvasive blood glucose concentration monitoring

    NASA Astrophysics Data System (ADS)

    Larin, Kirill V.

    Approximately 14 million people in the USA and more than 140 million people worldwide suffer from diabetes mellitus. The current glucose sensing technique involves a finger puncture several times a day to obtain a droplet of blood for analysis. There have been enormous efforts by many scientific groups and companies to quantify glucose concentration noninvasively using different optical techniques. However, these techniques face limitations associated with low sensitivity, accuracy, and insufficient specificity of glucose concentrations over a physiological range. Optical coherence tomography (OCT), a new technology, is being applied for noninvasive imaging in tissues with high resolution. OCT utilizes sensitive detection of photons coherently scattered from tissue. The high resolution of this technique allows for exceptionally accurate measurement of tissue scattering from a specific layer of skin compared with other optical techniques and, therefore, may provide noninvasive and continuous monitoring of blood glucose concentration with high accuracy. In this dissertation work I experimentally and theoretically investigate feasibility of noninvasive, real-time, sensitive, and specific monitoring of blood glucose concentration using an OCT-based biosensor. The studies were performed in scattering media with stable optical properties (aqueous suspensions of polystyrene microspheres and milk), animals (New Zealand white rabbits and Yucatan micropigs), and normal subjects (during oral glucose tolerance tests). The results of these studies demonstrated: (1) capability of the OCT technique to detect changes in scattering coefficient with the accuracy of about 1.5%; (2) a sharp and linear decrease of the OCT signal slope in the dermis with the increase of blood glucose concentration; (3) the change in the OCT signal slope measured during bolus glucose injection experiments (characterized by a sharp increase of blood glucose concentration) is higher than that measured in

  6. Metabolic alterations in the human erythrocyte produced by increases in glucose concentration

    PubMed Central

    Travis, Susan F.; Morrison, Anthony D.; Clements, Rex S.; Winegrad, Albert I.; Oski, Frank A.

    1971-01-01

    Human erythrocytes incubated in medium containing 50 mM glucose have increased intracellular sorbitol and fructose concentrations as compared with samples incubated with 5 mM glucose. Increased medium glucose concentration did not significantly alter total glucose consumption or lactate production. However, the intracellular lactate:pyruvate ratio rose, the concentrations of fructose diphosphate, and triose phosphates increased, and the 2,3-diphosphoglycerate concentration fell. [14C]O2 production from glucose-1-14C also increased with increased medium glucose concentration. These changes are believed to reflect changes in the redox states of the diphosphopyridine nucleotide/reduced form of diphosphopyridine nucleotide (NAD/NADH) and nicotinamide—adenine dinucleotide phosphate/reduced form of nicotinamide—adenine dinucleotide phosphate (NADP/NADPH) couples resulting from increased activity of the polyol pathway. Addition of pyruvate to the incubation media prevented these changes. These studies illustrate that an increase in the red cell's normal substrate, glucose, can produce changes in red cell metabolism. PMID:4398937

  7. Analysis of Blood Glucose Concentration by Interstitial Fluid Extracted in a Minimally Invasive way

    NASA Astrophysics Data System (ADS)

    Hu, Xiaotang; Xu, Kexin; Cao, Xuejun; Qu, Xinghua; Li, Dachao

    2009-08-01

    A novel minimally invasive way to measure blood glucose concentration is proposed by combining interstitial fluid (ISF) transdermal extraction and surface plasmon resonance (SPR) detection. 55 kHz low-frequency ultrasound pulses are applied for 30 seconds to enhance the skin permeability and then interstitial fluid is extracted out of skin by vacuum. The glucose concentration in the interstitial fluid is determined using an optical SPR sensor that measures the refractive index. A protein-glucose binding technology using D-galactose/D-glucose Binding Protein for specific absorption of glucose is also employed to increase SPR measurement precision. The mathematical model to express the correlation between interstitial fluid glucose and blood glucose is also developed by considering the changes of the skin conductivity. The feasibility of this method is validated for clinical application with the requirements of bloodless, painless, continuous glucose monitoring and a prototype microfluidic diabetes-monitoring device is under development with a current glucose resolution of approximately 1 mg/l.

  8. High-resolution surface plasmon resonance biosensing system for glucose concentration detecting

    NASA Astrophysics Data System (ADS)

    Huang, Xian; Li, Dachao; Yu, Haixia; Huang, Fuxiang; Hu, Xiaotang; Xu, Kexin

    2007-02-01

    Glucose is one of the most important substances widely contained in organism and food, thus people pay much attention in researching and improving the way for the detection of glucose. Traditional ways, although precise and reliable when in high concentration and large amount of sample, have unconvincing performance in detecting mixture and solution with low concentration and micro-volume. As far as the ideal way is concerned, it should not only specifically detect the glucose and exclude other components in solution, but also meet the need of micro-sample (approximately 5μL) and low concentration. We introduced D-galactose/D-glucose Binding Protein (GGBP) - a kind of protein which has the ability to absorb the glucose specifically, to construct a novel surface plasmon resonance measuring system. By immobilizing GGBP onto the surface of the SPR sensor, we develop a new detecting system for glucose testing in mixed solution. The experimental result indicates that compared with 0.1g/L before immobilization of GGBP, the detecting limit or the resolution of glucose testing rises to 1mg/L after the immobilization, the system succeeds in distinguishing glucose from other components in mixture, which reveals a bright future to apply SPR in the minimally invasive diabetes testing and food quality control.

  9. An acute increase in fructose concentration increases hepatic glucose-6-phosphatase mRNA via mechanisms that are independent of glycogen synthase kinase-3 in rats.

    PubMed

    Wei, Yuren; Bizeau, Michael E; Pagliassotti, Michael J

    2004-03-01

    It appears that low amounts of fructose improve, whereas increased concentrations impair glucose tolerance and hepatic glucose metabolism. In this study, we compared directly the effects of low vs. high portal vein fructose concentrations on hepatic glucose metabolism in rats, using glucose-6-phosphatase gene expression as an endpoint. In the control group (C; n = 7), pancreatic clamps were performed using somatostatin and replacement of insulin such that basal glucose levels were maintained. In the experimental groups (n = 8/group), hyperglycemic, hyperinsulinemic pancreatic clamps were performed in which glucose (G) or glucose + fructose was infused into a jejunal vein. Fructose was infused to achieve either low (F1; <0.3 mmol/L) or high (F2; >1.0 mmol/L) portal vein concentrations. Total sugar load to the liver was equalized among the 3 experimental groups. Compared with C, liver glucose-6-phosphatase catalytic subunit mRNA was reduced by approximately 55% in G and F1, whereas it was increased approximately 180% in F2. F2 did not differentially affect glucose-6-phosphate translocase or phosphoenolpyruvate carboxykinase mRNA levels in liver, nor kidney glucose-6-phosphatase catalytic subunit mRNA. Livers from the F2 group were characterized by an accumulation of pentose phosphate intermediates and reduced phosphorylation of glycogen synthase kinase-3 (active form). However, in separate studies (n = 5/group), the infusion of a glycogen synthase kinase-3 inhibitor did not prevent the effects of F2 on glucose-6-phosphatase gene expression. We hypothesize that elevated fructose concentrations, similar to levels achieved after ingestion of sucrose- or fructose-enriched meals, initiate signals within the liver that elicit selective changes in hepatic gene expression.

  10. Wood properties of Scots pines (Pinus sylvestris) grown at elevated temperature and carbon dioxide concentration.

    PubMed

    Kilpeläinen, Antti; Peltola, Heli; Ryyppö, Aija; Sauvala, Kari; Laitinen, Kaisa; Kellomäki, Seppo

    2003-09-01

    Impacts of elevated temperature and carbon dioxide concentration ([CO2]) on wood properties of 15-year-old Scots pines (Pinus sylvestris L.) grown under conditions of low nitrogen supply were investigated in open-top chambers. The treatments consisted of (i) ambient temperature and ambient [CO2] (AT+AC), (ii) ambient temperature and elevated [CO2] (AT+EC), (iii) elevated temperature and ambient [CO2] (ET+AC) and (iv) elevated temperature and elevated [CO2] (ET+EC). Wood properties analyzed for the years 1992-1994 included ring width, early- and latewood width and their proportions, intra-ring wood density (minimum, maximum and mean, as well as early- and latewood densities), mean fiber length and chemical composition of the wood (cellulose, hemicellulose, lignin and acetone extractive concentration). Absolute radial growth over the 3-year period was 54% greater in AT+EC trees and 30 and 25% greater in ET+AC and ET+EC trees, respectively, than in AT+AC trees. Neither elevated temperature nor elevated [CO2] had a statistically significant effect on ring width, early- and latewood widths or their proportions. Both latewood density and maximum intra-ring density were increased by elevated [CO2], whereas fiber length was increased by elevated temperature. Hemicellulose concentration decreased and lignin concentration increased significantly in response to elevated temperature. There were no statistically significant interaction effects of elevated temperature and elevated [CO2] on the wood properties, except on earlywood density.

  11. Salivary glucose concentration exhibits threshold kinetics in normal-weight, overweight, and obese children

    PubMed Central

    Hartman, Mor-Li; Goodson, J Max; Barake, Roula; Alsmadi, Osama; Al-Mutawa, Sabiha; Ariga, Jitendra; Soparkar, Pramod; Behbehani, Jawad; Behbehani, Kazem; Welty, Francine

    2015-01-01

    Background Metabolic syndrome in childhood predicts the development of cardiovascular disease and type 2 diabetes (T2D) in adulthood. Testing for features of metabolic syndrome, such as fasting plasma glucose concentration, requires blood sampling which can be difficult in children. Here we evaluated salivary glucose concentration as a surrogate measurement for plasma glucose concentration in 11-year-old US children. Methods Children from Portland, Maine, and Cambridge, Massachusetts, with a mean age of 10.6±0.2 years provided 6-hour fasting samples of both blood and whole saliva. Salivary glucose levels were measured with a high-sensitivity assay (sensitivity =0.002 mg/dL). Plasma glucose levels were determined by a commercial clinical laboratory. Blood pressure, salivary flow rate, height, and weight were also measured. Results Of the 65 children enrolled, there were two underweight children (3.1%), 30 normal-weight children (46.2%), 12 overweight children (18.4%), and 21 obese children (32.3%). The mean overall glucose concentrations were 0.11±0.02 mg/dL in saliva and 86.3±0.8 mg/dL in plasma, and these did not differ significantly by body–weight groups. By regression analysis, the plasma concentration equaled 13.5 times the saliva concentration, with a threshold level of 84.8 mg/dL. Salivary glucose values less than threshold plasma concentration were essentially zero. Diagnostic analysis indicated a positive predictive value of 50%, a negative predictive value of 90%, and a sensitivity and specificity both of approximately 75%. The salivary glucose concentration did not vary with saliva flow rate. Conclusion Taking into account the threshold response characteristics of the salivary glucose concentration response, these results suggest that testing salivary glucose levels may be useful as a screening assay for high fasting plasma glucose levels. The low false positive value is important to assure a low fraction of missed diagnoses. PMID:25565874

  12. Effect of ground cinnamon on postprandial blood glucose concentration in normal-weight and obese adults.

    PubMed

    Magistrelli, Ashley; Chezem, Jo Carol

    2012-11-01

    In healthy normal-weight adults, cinnamon reduces blood glucose concentration and enhances insulin sensitivity. Insulin resistance, resulting in increased fasting and postprandial blood glucose and insulin levels, is commonly observed in obese individuals. The objective of the study was to compare declines in postprandial glycemic response in normal-weight and obese subjects with ingestion of 6 g ground cinnamon. In a crossover study, subjects consumed 50 g available carbohydrate in instant farina cereal, served plain or with 6 g ground cinnamon. Blood glucose concentration, the main outcome measure, was assessed at minutes 0, 15, 30, 45, 60, 90, and 120. Repeated-measures analysis of variance evaluated the effects of body mass index (BMI) group, dietary condition, and time on blood glucose. Paired t-test assessed blood glucose at individual time points and glucose area under the curve (AUC) between dietary conditions. Thirty subjects between the ages of 18 and 30 years, 15 with BMIs between 18.5 and 24.9 and 15 with BMIs of 30.0 or more, completed the study. There was no significant difference in blood glucose between the two BMI groups at any time point. However, in a combined analysis of all subjects, the addition of cinnamon to the cereal significantly reduced 120-minute glucose AUC (P=0.008) and blood glucose at 15 (P=0.001), 30 (P<0.001), 45 (P<0.001), and 60 (P=0.001) minutes. At 120 minutes, blood glucose was significantly higher with cinnamon consumption (P<0.001). These results suggest cinnamon may be effective in moderating postprandial glucose response in normal weight and obese adults.

  13. Spectrophotometric Analysis of Ethanol and Glucose Concentrations in Yeast Culture Media.

    PubMed

    Caudy, Amy A

    2017-09-01

    Fermentative growth on glucose is one of the most widely studied conditions of yeast growth in the laboratory. The production of ethanol from sugars is relevant to the wine, beer, and bread industries and to production of biofuels. Assaying the levels of glucose and ethanol in yeast growth medium allows the experimenter to determine the consumption of the carbon source glucose and the production of ethanol. This protocol describes enzyme-coupled assays for determination of glucose and ethanol concentrations in a sample of cell-free culture medium. Enzymes convert glucose or ethanol into other compounds through chemical reactions that reduce NAD(P)(+) to NAD(P)H, and the production of NAD(P)H is measured using a spectrophotometer. The methods presented are highly sensitive, with a detection limit of ∼0.4 mg/L of glucose and 50 mg/L of ethanol, and also have the advantage of high specificity. For example, glucose and fructose have identical chemical formulas and thus cannot be distinguished by a mass spectrometer, but the enzyme assay presented here is specific for glucose. The glucose assay can be coupled to other assays to determine the quantity of additional carbohydrates such as fructose, trehalose, and glycogen. © 2017 Cold Spring Harbor Laboratory Press.

  14. Chronic Exposure to Excess Nutrients Left-shifts the Concentration Dependence of Glucose-stimulated Insulin Secretion in Pancreatic β-Cells.

    PubMed

    Erion, Karel A; Berdan, Charles A; Burritt, Nathan E; Corkey, Barbara E; Deeney, Jude T

    2015-06-26

    Hyperinsulinemia (HI) is elevated plasma insulin at basal glucose. Impaired glucose tolerance is associated with HI, although the exact cause and effect relationship remains poorly defined. We tested the hypothesis that HI can result from an intrinsic response of the β-cell to chronic exposure to excess nutrients, involving a shift in the concentration dependence of glucose-stimulated insulin secretion. INS-1 (832/13) cells were cultured in either a physiological (4 mm) or high (11 mm) glucose concentration with or without concomitant exposure to oleate. Isolated rat islets were also cultured with or without oleate. A clear hypersensitivity to submaximal glucose concentrations was evident in INS-1 cells cultured in excess nutrients such that the 25% of maximal (S0.25) glucose-stimulated insulin secretion was significantly reduced in cells cultured in 11 mm glucose (S0.25 = 3.5 mm) and 4 mm glucose with oleate (S0.25 = 4.5 mm) compared with 4 mm glucose alone (S0.25 = 5.7 mm). The magnitude of the left shift was linearly correlated with intracellular lipid stores in INS-1 cells (r(2) = 0.97). We observed no significant differences in the dose responses for glucose stimulation of respiration, NAD(P)H autofluorescence, or Ca(2+) responses between left- and right-shifted β-cells. However, a left shift in the sensitivity of exocytosis to Ca(2+) was documented in permeabilized INS-1 cells cultured in 11 versus 4 mm glucose (S0.25 = 1.1 and 1.7 μm, respectively). Our results suggest that the sensitivity of exocytosis to triggering is modulated by a lipid component, the levels of which are influenced by the culture nutrient environment.

  15. Chronic Exposure to Excess Nutrients Left-shifts the Concentration Dependence of Glucose-stimulated Insulin Secretion in Pancreatic β-Cells*

    PubMed Central

    Erion, Karel A.; Berdan, Charles A.; Burritt, Nathan E.; Corkey, Barbara E.; Deeney, Jude T.

    2015-01-01

    Hyperinsulinemia (HI) is elevated plasma insulin at basal glucose. Impaired glucose tolerance is associated with HI, although the exact cause and effect relationship remains poorly defined. We tested the hypothesis that HI can result from an intrinsic response of the β-cell to chronic exposure to excess nutrients, involving a shift in the concentration dependence of glucose-stimulated insulin secretion. INS-1 (832/13) cells were cultured in either a physiological (4 mm) or high (11 mm) glucose concentration with or without concomitant exposure to oleate. Isolated rat islets were also cultured with or without oleate. A clear hypersensitivity to submaximal glucose concentrations was evident in INS-1 cells cultured in excess nutrients such that the 25% of maximal (S0.25) glucose-stimulated insulin secretion was significantly reduced in cells cultured in 11 mm glucose (S0.25 = 3.5 mm) and 4 mm glucose with oleate (S0.25 = 4.5 mm) compared with 4 mm glucose alone (S0.25 = 5.7 mm). The magnitude of the left shift was linearly correlated with intracellular lipid stores in INS-1 cells (r2 = 0.97). We observed no significant differences in the dose responses for glucose stimulation of respiration, NAD(P)H autofluorescence, or Ca2+ responses between left- and right-shifted β-cells. However, a left shift in the sensitivity of exocytosis to Ca2+ was documented in permeabilized INS-1 cells cultured in 11 versus 4 mm glucose (S0.25 = 1.1 and 1.7 μm, respectively). Our results suggest that the sensitivity of exocytosis to triggering is modulated by a lipid component, the levels of which are influenced by the culture nutrient environment. PMID:25934392

  16. Continuous elevation of blood growth hormone concentrations by beeswax implant.

    PubMed

    Davis, S L; Dodson, M V; Ohlson, D L

    1983-09-01

    We examined constancy of release of purified ovine growth hormone from an implant containing soybean oil and beeswax. Implants contained an amount of growth hormone that was sufficient to increase concentrations in blood plasma by 20 and 40 ng/ml and to maintain those concentrations over 1 wk. Growth hormone in plasma increased to approximately 65 ng/ml in lambs receiving low dose implants the 1st day after implantation, returned to 31 ng/ml on day 2, and remained near this concentration for the remainder of the week. Pulse release of growth hormone was not similiar in the high dose lambs where growth hormone concentration in plasma averaged 45 ng/ml 1 day after implantation, then gradually increased to 60 ng/ml on day 6. Unimplanted control lambs had mean growth hormone concentrations of 2.9 to 3.9 ng/ml throughout the 6-day observation. This approach should interest investigators studying the chronic influence of purified or synthetic growth hormone on dairy cows, beef steers, or lambs.

  17. The Effects of Oxygen Level and Glucose Concentration on the Metabolism of Porcine TMJ Disc Cells

    PubMed Central

    Cisewski, Sarah E.; Zhang, Lixia; Kuo, Jonathan; Wright, Gregory J.; Wu, Yongren; Kern, Michael J.; Yao, Hai

    2015-01-01

    Objective To determine the combined effect of oxygen level and glucose concentration on cell viability, ATP production, and matrix synthesis of temporomandibular joint (TMJ) disc cells. Design TMJ disc cells were isolated from pigs aged 6-8 months and cultured in a monolayer. Cell cultures were preconditioned for 48 hours with 0, 1.5, 5, or 25mM glucose DMEM under 1%, 5%, 10%, or 21% O2 level, respectively. The cell viability was measured using the WST-1 assay. ATP production was determined using the Luciferin-Luciferase assay. Collagen and proteoglycan synthesis were determined by measuring the incorporation of [2, 3-3H]proline and [35S]sulfate into the cells, respectively. Results TMJ disc cell viability significantly decreased (P<0.0001) without glucose. With glucose present, decreased oxygen levels significantly increased viability (P<0.0001), while a decrease in glucose concentration significantly decreased viability (P<0.0001). With glucose present, decreasing oxygen levels significantly reduced ATP production (P<0.0001) and matrix synthesis (P<0.0001). A decreased glucose concentration significantly decreased collagen synthesis (P<0.0001). The interaction between glucose and oxygen was significant in regards to cell viability (P<0.0001), ATP production (P=0.00015), and collagen (P=0.0002) and proteoglycan synthesis (P<0.0001). Conclusions Although both glucose and oxygen are important, glucose is the limiting nutrient for TMJ disc cell survival. At low oxygen levels, the production of ATP, collagen, and proteoglycan are severely inhibited. These results suggest that steeper nutrient gradients may exist in the TMJ disc and it may be vulnerable to pathological events that impede nutrient supply. PMID:26033165

  18. Prognostic value of admission blood glucose concentration and diabetes diagnosis on survival after acute myocardial infarction: results from 4702 index cases in routine practice.

    PubMed

    Squire, Ian B; Nelson, Christopher P; Ng, Leong L; Jones, David R; Woods, Kent L; Lambert, Paul C

    2010-04-01

    The diagnosis of diabetes and admission blood glucose concentration are associated with adverse outcome after acute coronary syndromes. We compared the relative association with survival after ST elevation AMI (acute myocardial infarction) of admission blood glucose concentration and of diabetes diagnosis. We carried out a retrospective cohort study in 4702 consecutive patients with STEMI (ST elevation AMI) occurring from 1 April 1993 to 31 December 2005, assessed for mortality at 30 days and 1 year. Patients were classified according to antecedent diabetes and by blood glucose concentration at admission (quartile 1, <7 mmol/l; quartile 2, 7–8.2 mmol/l;quartile 3, 8.3–10.9 mmol/l; quartile 4, 11 mmol/l). Multivariable models were constructed for determinants of mortality, including year of STEMI and demographic variables, entering blood glucose concentration and antecedent diabetes individually and together. All-cause 30-day and 1-year mortality were 22.8% and 31.3% for patients with antecedent diabetes, compared with 16.3% and 23.0% respectively for those without. For glucose quartiles 1, 2, 3 and 4, crude 30-day mortality was 9.0%, 10.6%, 17.9% and 31.0%. Adjusted 30-day mortality risk was similar in quartile 2, higher by >80% in quartile 3 and by >150% in quartile 4, compared with glucose quartile 1. Antecedent diabetes was associated with an increase in mortality [unadjusted odds ratio (OR)1.52 (95% CI 1.24, 1.86)]. On multivariable analysis (excluding glucose quartile), this reduced to 1.24 (0.98, 1.58) and changed to a small, statistically non-significant reduction in risk when glucose quartile was added to the analysis [adjusted OR 0.87 (0.67, 1.13)]. Inclusion of antecedent diabetes in multivariable models did not add to the predictive value for mortality of glucose quartile(P=0.368). Similar relationships were observed for 1 year mortality. In patients with STEMI, blood glucose concentration shows graded association with risk of 30-day and 1-year

  19. Modelling the growth and ethanol production of Brettanomyces bruxellensis at different glucose concentrations.

    PubMed

    Aguilar-Uscanga, M G; Garcia-Alvarado, Y; Gomez-Rodriguez, J; Phister, T; Delia, M L; Strehaiano, P

    2011-08-01

    To study the effect of glucose concentrations on the growth by Brettanomyces bruxellensis yeast strain in batch experiments and develop a mathematical model for kinetic behaviour analysis of yeast growing in batch culture. A Matlab algorithm was developed for the estimation of model parameters. Glucose fermentation by B. bruxellensis was studied by varying its concentration (5, 9.3, 13.8, 16.5, 17.6 and 21.4%). The increase in substrate concentration up to a certain limit was accompanied by an increase in ethanol and biomass production; at a substrate concentration of 50-138 g l(-1), the ethanol and biomass production were 24, 59 and 6.3, 11.4 g l(-1), respectively. However, an increase in glucose concentration to 165 g l(-1) led to a drastic decrease in product formation and substrate utilization. The model successfully simulated the batch kinetic observed in all cases. The confidence intervals were also estimated at each phase at a 0.95 probability level in a t-Student distribution for f degrees of freedom. The maximum ethanol and biomass yields were obtained with an initial glucose concentration of 138 g l(-1). These experiments illustrate the importance of using a mathematical model applied to kinetic behaviour on glucose concentration by B. bruxellensis. © 2011 The Authors. Letters in Applied Microbiology © 2011 The Society for Applied Microbiology.

  20. Relationship between plasma glucose and insulin concentration, glucose production, and glucose disposal in normal subjects and patients with non-insulin-dependent diabetes.

    PubMed Central

    Chen, Y D; Jeng, C Y; Hollenbeck, C B; Wu, M S; Reaven, G M

    1988-01-01

    The changes in hepatic glucose production (Ra), tissue glucose disposal (Rd), and plasma glucose and insulin concentration that took place over a 16-h period from 10 to 2 p.m. were documented in 14 individuals; 8 with non-insulin-dependent diabetes mellitus (NIDDM) and 6 with normal glucose tolerance. Values for Ra were higher than normal in patients with NIDDM at 10 p.m. (4.73 +/- 0.41 vs. 3.51 +/- 0.36 mg/kg per min, P less than 0.001), but fell at a much faster rate throughout the night than that seen in normal subjects. As a consequence, the difference between Ra in normal individuals and patients with NIDDM progressively narrowed, and by 2 p.m., had ceased to exist (1.75 +/- 0.61 vs. 1.67 +/- 0.47 mg/kg per min, P = NS). Plasma glucose concentration also declined in patients with NIDDM over the same period of time, but they remained quite hyperglycemic, and the value of 245 +/- 27 mg/dl at 2 p.m. was about three times greater than in normal individuals. Plasma insulin concentrations also fell progressively from 10 to 2 p.m., and were similar in both groups throughout most of the 16-h study period. Thus, the progressive decline in Ra in patients with NIDDM occurred despite concomitant falls in both plasma glucose and insulin concentration. Glucose disposal rates also fell progressively in both groups, but the magnitude of the fall was greater in patients with NIDDM. Consequently, Rd in patients with NIDDM was higher at 10 p.m. (3.97 +/- 0.48 vs. 3.25 +/- 0.13 mg/kg per min, P less than 0.001) and lower the following day at 2 p.m. (1.64 +/- 0.21 vs. 1.97 +/- 0.35 mg/kg per min, P less than 0.01). These results indicate that a greatly expanded pool size can exist in patients with NIDDM at a time when values for Ra are identical to those in normal subjects studied under comparable conditions, which suggests that fasting hyperglycemia in NIDDM is not simply a function of an increase in Ra. PMID:3292584

  1. Whey protein concentrate storage at elevated temperature and humidity

    USDA-ARS?s Scientific Manuscript database

    Dairy processors are finding new export markets for whey protein concentrate (WPC), a byproduct of cheesemaking, but they need to know if full-sized bags of this powder will withstand high temperature and relative humidity (RH) levels during unrefrigerated storage under tropical conditions. To answ...

  2. Opto-acoustic monitoring of blood optical properties as a function of glucose concentration

    NASA Astrophysics Data System (ADS)

    Bednov, Andrey A.; Savateeva, Elena V.; Oraevsky, Alexander A.

    2003-06-01

    Time-resolved optoacoustic (OA) method was employed to measure changes in glucose concentration in the whole and diluted blood. An increase of the glucose level in tissue results in a corresponding decrease of optical scattering. Relative changes in tissue optical scattering can be obtained by measuring the effective optical attenuation coefficient, μeff by exponential fitting of the time-resolved optoacoustic profiles. Glucose effects in blood have been investigated using the forward mode of OA detection performed in the visible (at the wavelength, λ=532 nm) and near infrared (λ=1064 nm) spectral ranges. In our previous set of experiments, the OA studies performed in model media in vitro and biological tissue (sclera) in vivo demonstrated gradual reduction of optical scattering with the increase in glucose level. The present study has supported our previous observations. However, one novel effect was observed comprised of a transient increase in μeff during the first 5-10 minutes after injection of glucose. This phenomenon may be explained by changes in erythrocytes shape and size as a result of their adaptation to hyperglycemic conditions. Our observation was supported by light microscopy images of red blood cells under normal and hyperglycemic conditions. With glucose concentration changing rapidly (osmotic shock), any small reduction in ´eff due to the glucose-induced decrease of relative refraction index of blood, can be compensated or even overwhelmed by the increase in ´eff due to erythrocyte shrinkage and/or spherulation. Further cellular adaptation to glucose make erythrocytes return to their normal shape of biconcave disks about 7-μm in diameter. The kinetics of the effective optical attenuation was studies in response to glucose injection in order to better understand the mechanisms of erythrocyte adaptation to osmotic shock and to determine the time course of RBCs adaptation to various glucose concentrations. Finally, Mannitol as alternative

  3. Increasing Glucose Concentrations Interfere with Estimation of Electrolytes by Indirect Ion Selective Electrode Method.

    PubMed

    Goyal, Bela; Datta, Sudip Kumar; Mir, Altaf A; Ikkurthi, Saidaiah; Prasad, Rajendra; Pal, Arnab

    2016-04-01

    The estimation of electrolytes like sodium (Na(+)), potassium (K(+)) and chloride (Cl(-)) using direct and indirect ion-selective electrodes (ISE) is a routine laboratory practice. Interferents like proteins, triglycerides, drugs etc. are known to affect the results. The present study was designed to look into the effect of increasing glucose concentrations on estimation of Na(+), K(+) and Cl(-) by direct and indirect ISE. Pooled sera was mixed with glucose stock solution (20 g/dL) prepared in normal saline to obtain glucose concentrations ranging from ~100 to ~5000 mg/dL. Na(+), K(+) and Cl(-) levels were estimated by direct and indirect ISE analyzers and results were statistically analysed using ANOVA and Pearson's correlation. Similar experiment was also performed in 24 h urine sample from healthy subjects. Significant difference was observed between Na(+) and Cl(-) measurements by direct and indirect ISE, with indirect ISE values being consistently higher than direct ISE. Besides this, significant difference was observed amongst Na(+) and Cl(-) values from baseline values obtained by indirect ISE at glucose concentrations ≥2486 mg/dL. However, no such difference was observed with direct ISE. Na(+) and Cl(-) estimation by indirect ISE showed significant negative correlation with glucose concentration, more so, above ~2000 mg/dL. K(+), however, showed no significant difference with varying glucose. Similar results were observed in 24 h urine samples with a significant difference observed amongst Na(+) and Cl(-) values at ≥2104 mg/dL glucose. Thus we conclude that high glucose concentrations interfere significantly in estimation of Na(+) and Cl(-) by indirect ISE in serum as well as urine.

  4. Elevated Oxygen Consumption Rate in Response to Acute Low- Glucose Stress: Metformin Restores Rate to Normal Level

    PubMed Central

    Williams, Emmanuel D.; Rogers, Steven C.; Zhang, Xiaomin; Azhar, Gohar; Wei, Jeanne Y.

    2015-01-01

    Cardiovascular Disease (CVD) continues to be the leading cause of mortality among all age demographics in the United States, with the highest occurrence in populations aged 65 and older. Glucose levels, particularly hyperglycemia, are associated with the premature onset of age-related diseases including CVD. A major challenge in the treatment of elderly patients with chronically elevated blood glucose is the frequency of hypoglycemic episodes. Molecular mechanisms of hypoglycemia remain unclear, but are associated with premature onset of age-related-diseases. Here we report a mitochondrial metabolic profile assessing short-term (up to six hours) and longer-term (12–24 hours) durations of low-glucose stress. We observed that the antidiabetic biguanide and mitochondrial complex I inhibitor, metformin, can lower and restore the elevated oxygen consumption rate during shorter-term glucose stress to levels similar to that of cells cultured in normal glucose. This effect appears, in part, to involve activation of the 5′ AMP-activated protein kinase (AMPK). PMID:26256471

  5. Artichoke cultivars (var. "Blanca de Tudela") under elevated ozone concentrations.

    PubMed

    Sanz, M J; Porcuna, J L; Calvo, E; Martín, C

    2002-03-26

    Ozone concentrations rise to phytotoxic levels from spring to autumn at western Mediterranean basin coastal sites, where artichoke is one of the most important crops. Simultaneously, from year to year and especially since the early 1980s, resprouting of the stumps has been decreasing in Valencian Community artichoke plantations. To see if ozone might be playing a role in this decrease, a number of plants were exposed to different levels of ozone. Results of the ozone treatments showed reduced biomass in the offshoots of plants exposed to the highest ozone treatment. The exposure to ambient ozone during the stump-establishment period, when compared to filtered-air conditions, resulted in a reduction in yield when plants were transplanted in the field under ambient ozone concentrations. And when plants were exposed to acute short picks, typical ozone visual injury appeared in the older leaves.

  6. High concentration of glucose inhibits glomerular endothelial eNOS through a PKC mechanism.

    PubMed

    Chu, Shaoyou; Bohlen, H Glenn

    2004-09-01

    Kidney glomeruli are important targets of diabetic nephropathy. We hypothesized a high concentration of glucose could suppress glomerular endothelial nitric oxide synthase (eNOS) by a protein kinase C (PKC) mechanism, as has been found in other tissues. Mouse kidney slices (150-200 microm) were bathed in Hanks' solution with 100 microM L-arginine and exposed to either 5 or 20-30 mM D-glucose. Immunofluorescence identified only eNOS in normal mouse glomeruli. Measurements of glomerular NO concentration with NO-sensitive fluorescent dye (4,5-diaminofluorescein diacetate) using confocal microscopy and NO-sensitive microelectrodes verified that resting glomeruli had active production of NO that was inhibited by N(G)-nitro-L-arginine methyl ester. High-concentration (20-30 mM) D-glucose inhibited 60-70% of the NO production within 15-30 min; L-glucose at the same concentration did not have any effect. Inhibition of PKC-beta with 100 nM ruboxistaurin prevented eNOS suppression in high-glucose media. Activation of PKC with 100 nM phorbol ester also suppressed the glomerular NO concentration. We concluded that eNOS in the renal glomerular capillary endothelial cells is suppressed by activity of PKC at high-glucose concentrations comparable to those in diabetic animals and humans. The consequence is a rapid decline in the generation of NO in the glomerular endothelial cells in the presence of a high concentration of glucose.

  7. Jump neural network for real-time prediction of glucose concentration.

    PubMed

    Zecchin, Chiara; Facchinetti, Andrea; Sparacino, Giovanni; Cobelli, Claudio

    2015-01-01

    Prediction of the future value of a variable is of central importance in a wide variety of fields, including economy and finance, meteorology, informatics, and, last but not least important, medicine. For example, in the therapy of Type 1 Diabetes (T1D), in which, for patient safety, glucose concentration in the blood should be maintained in a defined normoglycemic range, the ability to forecast glucose concentration in the short-term (with a prediction horizon of around 30 min) might be sufficient to reduce the incidence of hypoglycemic and hyperglycemic events. Neural Network (NN) approaches are suitable for prediction purposes because of their ability to model nonlinear dynamics and handle in their inputs signals coming from different domains. In this chapter we illustrate the design of a jump NN glucose prediction algorithm that exploits past glucose concentration data, measured in real-time by a minimally invasive continuous glucose monitoring (CGM) sensor, and information on ingested carbohydrates, supplied by the patient himself or herself. The methodology is assessed by tuning the NN on data of ten T1D individuals and then testing it on a dataset of ten different subjects. Results with a prediction horizon of 30 min show that prediction of glucose concentration in T1D via NN is feasible and sufficiently accurate. The average time anticipation obtained is compatible with the generation of preventive hypoglycemic and hyperglycemic alerts and the improvement of artificial pancreas performance.

  8. Elevated cholesterol and bile acid synthesis in an adult patient with homozygous familial hypercholesterolemia. Reduction by a high glucose diet.

    PubMed

    Stacpoole, P W; Grundy, S M; Swift, L L; Greene, H L; Slonim, A E; Burr, I M

    1981-11-01

    Elevated levels of cholesterol synthesis are reported for several young children with homozygous familial hypercholesterolemia (HFH) and are considered to contribute directly to their hypercholesterolemia. In contrast, increased cholesterol production has not previously been found in adult patients with HFH. Using the fecal steroid balance technique, we studied rates of cholesterol and bile acid synthesis in a 24-yr-old man who had severe hypercholesterolemia typical of HFH and who lacked skin fibroblast low density lipoprotein (LDL) receptor activity. On an average diet (45% carbohydrate, 40% fat, 15% protein) mean +/- SEM cholesterol (24.8 +/- 1.4 mg/kg per d) and bile acid (11.1 +/- 1.6 mg/kg per d) excretion were approximately threefold higher than normal. When an isocaloric high carbohydrate, low fat diet (90.5% glucose oligosaccharides, 1.3% safflower oil, 8.2% crystalline amino acids was substituted, mean cholesterol (13.0 +/- 0.5 mg/kg per d) and bile acid (8.6 +/- 0.4 mg/kg per d) fell markedly. The decline in fecal steroid excretion was accompanied by modest reductions in plasma total and LDL cholesterol concentrations and by a softening of cutaneous xanthomata. Although the patient phenotypically and biochemically resembled the HFH state, his family pedigree was not noteable for hypercholesterolemia. While the patient's father had premature cardiovascular disease, his mother had no evidence of heart disease, had normal plasma total and LDL cholesterol levels, and had normal fibroblast LDL receptor activity. Likewise, the plasma cholesterol levels of three other members of the patient's family were normal. Despite the unusual genotypic background of this individual, however, the fecal balance data shows that elevated cholesterol and bile acid synthesis may occur in adult, as well as juvenile, patients with HFH and may be responsive to dietary control.

  9. Non-high-density lipoprotein cholesterol and other lipid indices vs elevated glucose risk in Arab adolescents.

    PubMed

    Al-Daghri, Nasser M; Aljohani, Naji J; Al-Attas, Omar S; Al-Saleh, Yousef; Wani, Kaiser; Alnaami, Abdullah M; Alfawaz, Hanan; Al-Ajlan, Abdulrahman S M; Kumar, Sudhesh; Chrousos, George P; Alokail, Majed S

    2015-01-01

    Non-high-density lipoprotein cholesterol (non-HDL-C) has been identified as a significant predictor of various cardiovascular events in adults. Limited studies have been conducted in the pediatric population with diverse results, depending on ethnic origin. None has been conducted in the Arabic adolescent population so far; this study aims to fill this gap. In this cross-sectional study, 1690 Saudi school adolescents (968 boys [mean age 14.8 ± 1.7] and 722 girls [mean age 14.6 ± 1.7]) were recruited. Anthropometrics were obtained. Fasting blood glucose and lipid profiles were quantified routinely. Non-HDL-C was calculated and screening was done for dyslipidemia using cutoffs obtained from the cohort and elevated fasting glucose. Using the 90th percentile cutoff obtained, the overall prevalence of high non-HDL-C (≥4.26 mmol/L) was 10.1%. Prevalence was slightly higher in girls (10.5%) than boys (9.9%). Non-HDL-C was similar to other lipids in terms of significant associations with anthropometric measures and glucose in both boys and girls. Elevated triglycerides was most predictive of elevated glucose in both girls (odds ratio 2.41; confidence interval 1.43-4.08; P = .001) and boys (odds ratio 2.61; confidence interval 1.70-4.0); P < .001). Non-HDL-C appears to be gender-specific and is cardiometabolically more associated with Saudi boys, despite higher levels in girls. It is inferior compared with triglycerides in assessing elevated glucose risk. Further investigations may provide a more definite value for non-HDL-C use as a biomarker in assessing cardiometabolic risk in the Arab adolescent population. Copyright © 2015 National Lipid Association. Published by Elsevier Inc. All rights reserved.

  10. [Effects of nitrogen fertilization on wheat leaf photosynthesis under elevated atmospheric CO2 concentration].

    PubMed

    Yu, Xian-feng; Zhang, Xu-cheng; Guo, Tian-wen; Yu, Jia

    2010-09-01

    In this paper, the effects of nitrogen (N) fertilization on the wheat leaf photosynthesis under long-term elevated atmospheric CO2 concentration (760 micromol x mol(-1)) was studied, based on the measurements of photosynthetic gas exchange parameters and light intensity-photosynthetic rate response curves at jointing stage. Under the long-term elevated atmospheric CO2 concentration, applying sufficient N could increase the wheat leaf photosynthetic rate (Pn), transpiration rate (Tr), and instantaneous water use efficiency (WUEi). Comparing with those under ambient atmospheric CO2 concentration, the Po and WUEi under the elevated atmospheric CO2 concentration increased, while the stomatal conductance (Gs) and intercellular CO2 concentration (Ci) decreased. With the increase of light flux intensity, the Pn and WUEi under the elevated atmospheric CO2 concentration were higher those under ambient atmospheric CO2 concentration, Gs was in adverse, while Ci and Tr had less change. At high fertilization rate of N, the Gs was linearly positively correlated with Pn, Tr, and WUEi, and the Gs and Ci had no correlation with each other under the elevated atmospheric CO2 concentration but negatively correlated under ambient atmospheric CO2 concentration. At low fertilization rate of N, the Gs had no correlations with Pn and WUEi but linearly positively correlated with Ci and Tr. It was suggested that under the elevated atmospheric CO2 concentration, the wheat leaf Pn at low N fertilization rate was limited by non-stomatal factor.

  11. Adaptive System Identification for Estimating Future Glucose Concentrations and Hypoglycemia Alarms.

    PubMed

    Eren-Oruklu, Meriyan; Cinar, Ali; Rollins, Derrick K; Quinn, Lauretta

    2012-08-01

    Many patients with diabetes experience high variability in glucose concentrations that includes prolonged hyperglycemia or hypoglycemia. Models predicting a subject's future glucose concentrations can be used for preventing such conditions by providing early alarms. This paper presents a time-series model that captures dynamical changes in the glucose metabolism. Adaptive system identification is proposed to estimate model parameters which enable the adaptation of the model to inter-/intra-subject variation and glycemic disturbances. It consists of online parameter identification using the weighted recursive least squares method and a change detection strategy that monitors variation in model parameters. Univariate models developed from a subject's continuous glucose measurements are compared to multivariate models that are enhanced with continuous metabolic, physical activity and lifestyle information from a multi-sensor body monitor. A real life application for the proposed algorithm is demonstrated on early (30 min in advance) hypoglycemia detection.

  12. Elevation of fasting morning glucose relative to hemoglobin A1c in normoglycemic patients treated with niacin and with statins.

    PubMed

    Rajanna, Veena; Campbell, Kristen B; Leimberger, Jeffrey; Mohanty, Bibhu D; Guyton, John R

    2012-01-01

    Niacin increases fasting glucose levels, and statins modestly increase the rate of new-onset diabetes. The clinical importance and mechanisms of these effects are not fully explored. On the basis of anecdotal observations, we hypothesized that elevated morning fasting glucose may be accompanied by relatively normal hemoglobin A1c (HbA1c) in patients treated with niacin and other lipid-modifying drugs. We conducted a retrospective cohort analysis to test this hypothesis. The Duke Lipid Clinic database (1994-2007) was screened for simultaneous determinations of fasting morning glucose and HbA1c, yielding 1483 data pairs among 554 subjects. Subjects with diabetes, by clinical diagnosis, medication, or any HbA1c ≥6.5%, or nondiabetes were analyzed separately. Repeated-measures linear regression featured glucose as dependent variable and included terms for HbA1c, drug(s), and their interaction. Regression lines for glucose on HbA1c had altered slopes in the presence of niacin and/or statin use in normoglycemic subjects. The corresponding interaction terms (drug and HbA1c) were significant (niacin P = .026, statin P = .013). Fibrate use had no effect (interaction P = .49). When modeled together, niacin and statin effects were independent. Regression curves in diabetic patients were not affected by lipid medications. Elevated fasting glucose may be accompanied by relatively normal HbA1c in niacin- and statin-treated patients. HbA1c reflects average daily glucose levels and is likely a better measure of the glycemic effect of lipid medications. Because our data were retrospective, confirmation from randomized trials is needed. Copyright © 2012 National Lipid Association. Published by Elsevier Inc. All rights reserved.

  13. Photoacoustic determination of glucose concentration in whole blood by a near-infrared laser diode

    NASA Astrophysics Data System (ADS)

    Zhao, Zuomin; Myllylae, Risto A.

    2001-06-01

    The near-infrared photoacoustic technique is recognized as a potential method for the non-invasive determination of human glucose, because near-infrared light can incident a few millimeters into human tissue, where it produces an acoustic wave capable of carrying information about the composition of the tissue. This paper demonstrates a photoacoustic glucose measurement in a blood sample as a step toward a non-invasive measurement. The experimental apparatus consists of a near-infrared laser diode operating with 4 micro joules pulse energy at 905 nm, a roller pump connected to a silicon plastic tube and a cuvette for circulating the blood sample. In addition, the apparatus comprises a PZT piezoelectric transducer integrated with a battery-powered preamplifier to receive the photoacoustic signal. During the experiment, a glucose solution is mixed into a human blood sample to change its concentration. Although the absorption coefficient of glucose is much smaller than that of blood in the near-infrared region, the osmotic and hydrophilic properties of glucose decrease the reduced scattering coefficient of blood caused by the dissolved glucose surrounding the blood cells. This changes the distribution of the absorbed optical energy in blood, which, in turn, produces a change in the photoacoustic signal. Our experiment demonstrates that signal amplitudes in fresh and stored blood samples in crease about 7% and 10%, respectively, when the glucose concentration reaches the upper limit of the physiological region (500 mg/dl).

  14. Influence of glucose concentrations on biofilm formation, motility, exoprotease production, and quorum sensing in Aeromonas hydrophila.

    PubMed

    Jahid, Iqbal Kabir; Lee, Na-Young; Kim, Anna; Ha, Sang-Do

    2013-02-01

    Aeromonas hydrophila recently has received increased attention because it is opportunistic and a primary human pathogen. A. hydrophila biofilm formation and its control are a major concern for food safety because biofilms are related to virulence. Therefore, we investigated biofilm formation, motility inhibition, quorum sensing, and exoprotease production of this opportunistic pathogen in response to various glucose concentrations from 0.05 to 2.5% (wt/vol). More than 0.05% glucose significantly impaired (P < 0.05) quorum sensing, biofilm formation, protease production, and swarming and swimming motility, whereas bacteria treated with 0.05% glucose had activity similar to that of the control (0% glucose). A stage shift biofilm assay revealed that the addition of glucose (2.5%) inhibited initial biofilm formation but not later stages. However, addition of quorum sensing molecules N-3-butanoyl-DL-homoserine lactone and N-3-hexanoyl homoserine lactone partially restored protease production, indicating that quorum sensing is controlled by glucose concentrations. Thus, glucose present in food or added as a preservative could regulate acyl-homoserine lactone quorum sensing molecules, which mediate biofilm formation and virulence in A. hydrophila.

  15. Determination of glucose concentrations using photonic crystal LEDs

    NASA Astrophysics Data System (ADS)

    Liao, Yu-Yang; Chen, Yung-Tsan; Chang, Cheng-Yu; Lan, Wen-Yi; Huang, Jian-Jang

    2016-09-01

    As internet of things (IOT) has become a popular topic in current consumer electronics, there is a demand for cost-effective sensors to monitor bio-signals. Traditional optical sensors employ low-dimensional gratings and high-resolution spectrometers to detect the refractive index changes of the solutions. In this work, we develop an alternative approach to correlate the concentration of molecules to the band diagrams of the photonic crystals. A relatively low-resolution spectrum analyzer can be employed, yet achieves higher sensitivity than traditional approaches.

  16. Elevated postmortem ethanol concentrations in an insulin-dependent diabetic.

    PubMed

    Collison, Ines B

    2005-10-01

    A 54-year-old woman (165 cm, 37 kg) was found dead in her home during a welfare check after not having been seen for at least three days. The body showed clear evidence of decomposition. Her head was in what appeared to be a pool of blood. The residence was clean, neat, and showed no evidence of violence. Insulin was found in the refrigerator, and syringes were in the kitchen cabinet. In agreement with these physical findings, her clinical history indicated that she suffered insulin-dependent diabetes mellitus. Autolytic changes were noticed at autopsy, and no obvious cause of death was demonstrated. The autopsy heart blood sample screened negative for cocaine and/or metabolite (benzoylecgonine), phenethylamines, opiates, and barbiturates by radioimmunoassay. The alcohol concentration was 0.51 g/dL in the blood, 0.04 g/dL in the brain, 0.08 g/dL in the liver, and 0.05 g/dL in the urine, and acetone levels were 42 mg/dL, 53 mg/dL, 14 mg/dL, and 19 mg/dL, respectively. Isopropanol was also present in all samples analyzed. The cause of death was ruled as metabolic acidosis due to diabetes mellitus. Possible bacterial postmortem production of ethanol is considered as an explanation for the increased concentration of ethanol found in the postmortem heart blood.

  17. Elevated Vancomycin Trough Concentration: Increased Efficacy and/or Toxicity?

    PubMed Central

    Elyasi, Sepideh; Khalili, Hossein; Dashti-Khavidaki, Simin; Emadi-Koochak, Hamid; Mohammadpour, Amirhooshang; Abdollahi, Alireza

    2014-01-01

    Vancomycin susceptibility of methicillin-resistant Staphylococcus aureus has been changed over time and its average minimum inhibitory concentration increased from 1.5 to 1.75 mg/L.A recently published guideline by the American Society of Health Pharmacist recommended a daily dose of 15-20 mg/Kg every 8 to 12 hours of vancomycin to achieve a trough concentration between 15-20 mg/L for treatment of severe infections. Medical records of 69 patients from infectious ward of Imam Khomeini hospital, with suspected or confirmed gram-positive infection who had at least one trough level of vancomycin, were evaluated regarding vancomycin therapeutic goal; efficacy and renal safety. Most of patients (60.6%) with severe infections did not achieve the recommended vancomycin trough level during treatment course. Time to normalization of the signs and symptoms of infection did not correlate with the patients’ serum vancomycin trough levels. At the end of treatment course, there was no significant correlation between patients’ creatinine clearance and vancomycin trough levels (P=0.32). However, patients’cratinine clearance showed a negatively significant correlation with trough level of vancomycin (P=0.01). Vancomycin induced nephrotoxicity was detected in 4.3% of the patients. These data showed that vancomycin trough level may not necessarily assure treatment success, and also it would not essentially predict the risk of vancomycin induced nephrotoxicity. However, more well designed studies with larger sample size needed for better clinical and practical judgment. PMID:25587313

  18. Elevated methane concentrations in trees of an upland forest

    NASA Astrophysics Data System (ADS)

    Covey, Kristofer R.; Wood, Stephen A.; Warren, Robert J., II; Lee, Xuhui; Bradford, Mark A.

    2012-08-01

    There is intense debate about whether terrestrial vegetation contributes substantially to global methane emissions. Although trees may act as a conduit for methane release from soils to atmosphere, the debate centers on whether vegetation directly produces methane by an uncharacterized, abiotic mechanism. A second mechanism of direct methane production in plants occurs when methanogens - microorganisms in the domain Archaea - colonize the wood of living trees. In the debate this biotic mechanism has largely been ignored, yet conditions that promote anaerobic activity in living wood, and hence potentially methane production, are prevalent across forests. We find average, growing season, trunk-gas methane concentrations >15,000 μL·L-1 in common, temperate-forest species. In upland habitat (where soils are not a significant methane source), concentrations are 2.3-times greater than in lowland areas, and wood cores produce methane in anaerobic, lab-assays. Emission rate estimates from our upland site are 52 ± 9.5 ng CH4 m-2 s-1; rates that are of a similar magnitude to the soil methane sink in temperate forest, and equivalent in global warming potential to ˜18% of the carbon likely sequestered by this forest. Microbial infection of one of the largest, biogenic sinks for carbon dioxide, living trees, might result in substantial, biogenic production of methane.

  19. Associations Between Paternally Transmitted Fetal IGF2 Variants and Maternal Circulating Glucose Concentrations in Pregnancy

    PubMed Central

    Petry, Clive J.; Seear, Rachel V.; Wingate, Dianne L.; Manico, Lucy; Acerini, Carlo L.; Ong, Ken K.; Hughes, Ieuan A.; Dunger, David B.

    2011-01-01

    OBJECTIVE To test the hypothesis that polymorphic variation in the paternally transmitted fetal IGF2 gene is associated with maternal glucose concentrations in the third trimester of pregnancy. RESEARCH DESIGN AND METHODS A total of 17 haplotype tag single nucleotide polymorphisms in the IGF2 gene region were genotyped in 1,160 mother/partner/offspring trios from the prospective Cambridge Baby Growth Study (n = 845 trios) and the retrospective Cambridge Wellbeing Study (n = 315 trios) (3,480 samples in total). Associations were tested between inferred parent-of-origin fetal alleles, z scores of maternal glucose concentrations 60 min. after an oral glucose load performed at week 28 of pregnancy, and offspring birth weights. RESULTS Using the minimum P value test, paternally transmitted fetal IGF2 polymorphisms were associated with maternal glucose concentrations; specifically, paternally transmitted fetal rs6578987 (P = 0.006), rs680 (P = 0.01), rs10770125 (P = 0.0002), and rs7924316 (P = 0.01) alleles were associated with increased maternal glucose concentrations in the third trimester of pregnancy and placental IGF-II contents at birth (P = 0.03). In contrast, there were no associations between maternal glucose concentrations and maternal or maternally transmitted fetal IGF2 genotypes. CONCLUSIONS Polymorphic variation in paternally transmitted fetal IGF2 is associated with increased maternal glucose concentrations in pregnancy and could potentially alter the risk of gestational diabetes in the mother. The association may be at least partially mediated by changes in placental IGF2 expression. PMID:21926269

  20. Elevated 1-h post-challenge plasma glucose levels in subjects with normal glucose tolerance or impaired glucose tolerance are associated with whole blood viscosity.

    PubMed

    Marini, Maria Adelaide; Fiorentino, Teresa Vanessa; Andreozzi, Francesco; Mannino, Gaia Chiara; Perticone, Maria; Sciacqua, Angela; Perticone, Francesco; Sesti, Giorgio

    2017-08-01

    It has been suggested that glucose levels ≥155 mg/dl at 1-h during an oral glucose tolerance test (OGTT) may predict development of type 2 diabetes and cardiovascular events among adults with normal glucose tolerance (NGT 1 h-high). Studies showed a link between increased blood viscosity and type 2 diabetes. However, whether blood viscosity is associated with dysglycemic conditions such as NGT 1 h-high, impaired glucose tolerance (IGT) or impaired fasting glucose (IFG) is unsettled. 1723 non-diabetic adults underwent biochemical evaluation and OGTT. A validated formula based on hematocrit and total plasma proteins was employed to estimate whole blood viscosity. Subjects were categorized into NGT with 1 h glucose <155 mg/dL (NGT-1 h-low), NGT-1 h-high, IFG and/or IGT. Hematocrit and blood viscosity values appeared significantly higher in individuals with NGT 1 h-high, IFG and/or IGT as compared to NGT 1 h-low subjects. Blood viscosity was significantly correlated with age, waist circumference, blood pressure, HbA1c, fasting, 1- and 2-h post-challenge insulin levels, total cholesterol and low-density lipoprotein, triglycerides, fibrinogen, white blood cell, and inversely correlated with high-density lipoprotein and insulin sensitivity. Of the four glycemic parameters, 1-h post-challenge glucose showed the strongest correlation with blood viscosity (β = 0.158, P < 0.0001) in a multivariate regression analysis model including several atherosclerosis risk factors. Our results demonstrate a positive relationship between blood viscosity and 1-h post-challenge plasma glucose. They also suggest that a subgroup of NGT individuals with 1-h post-challenge plasma >155 mg/dl have increased blood viscosity comparable to that observed in subjects with IFG and/or IGT.

  1. Elevated Methane Concentrations in Trees of an Upland Forest

    NASA Astrophysics Data System (ADS)

    Covey, K. R.; Wood, S. A.; Warren, R. J.; Lee, X.; Bradford, M. A.

    2013-12-01

    There is intense debate about whether terrestrial vegetation contributes substantially to global methane emissions. Although trees may act as a conduit for methane release from soils to atmosphere, the debate centers on whether vegetation directly produces methane by an uncharacterized, abiotic mechanism. A second mechanism of direct methane production in plants occurs when methanogens - microorganisms in the domain Archaea - colonize the wood of living trees. In the debate this biotic mechanism has largely been ignored, yet conditions that promote anaerobic activity in living wood, and hence potentially methane production, are prevalent across forests. We find average, growing season, trunk-gas methane concentrations >15,000 mL×L¬-1 in common, temperate-forest species. In upland habitat (where soils are not a significant methane source), concentrations are 2.3-times greater than in lowland areas, and wood cores produce methane in anaerobic, lab-assays. Emission rate estimates from our upland site are 52×9.5 ng CH4 m-2 s-1; rates that are of a similar magnitude to the soil methane sink in temperate forest, and equivalent in global warming potential to ~18% of the carbon likely sequestered by this forest. Additional preliminary results from a multi-authored collaborative study of the role of age-class, forest type, and latitude in driving the magnitude of emissions in the eastern forest will also be discussed. Microbial infection of one of the largest, biogenic sinks for carbon dioxide, living trees, might result in substantial, biogenic production of methane.

  2. Vasopressin activates Akt/mTOR pathway in smooth muscle cells cultured in high glucose concentration

    SciTech Connect

    Montes, Daniela K.; Brenet, Marianne; Muñoz, Vanessa C.; Burgos, Patricia V.; Villanueva, Carolina I.; Figueroa, Carlos D.; González, Carlos B.

    2013-11-29

    Highlights: •AVP induces mTOR phosphorylation in A-10 cells cultured in high glucose concentration. •The mTOR phosphorylation is mediated by the PI3K/Akt pathway activation. •The AVP-induced mTOR phosphorylation inhibited autophagy and stimulated cell proliferation. -- Abstract: Mammalian target of rapamycin (mTOR) complex is a key regulator of autophagy, cell growth and proliferation. Here, we studied the effects of arginine vasopressin (AVP) on mTOR activation in vascular smooth muscle cells cultured in high glucose concentration. AVP induced the mTOR phosphorylation in A-10 cells grown in high glucose, in contrast to cells cultured in normal glucose; wherein, only basal phosphorylation was observed. The AVP-induced mTOR phosphorylation was inhibited by a PI3K inhibitor. Moreover, the AVP-induced mTOR activation inhibited autophagy and increased thymidine incorporation in cells grown in high glucose. This increase was abolished by rapamycin which inhibits the mTORC1 complex formation. Our results suggest that AVP stimulates mTOR phosphorylation by activating the PI3K/Akt signaling pathway and, subsequently, inhibits autophagy and raises cell proliferation in A-10 cells maintained in high glucose concentration.

  3. The effect of treatment on pregnancy outcomes in women with one elevated oral glucose tolerance test value.

    PubMed

    Kokanalı, Mahmut Kuntay; Tokmak, Aytekin; Kaymak, Oktay; Cavkaytar, Sabri; Bilge, Ümit

    2014-10-01

    The aim of the study was to evaluate whether dietary intervention could reduce maternal and perinatal morbidity in pregnancies with one elevated 100 g oral glucose tolerance test (OGTT) value. The study was conducted among patients with positive 50 g glucose challenge test (GCT) and one elevated 100 g OGTT value. Plasma glucose value of 140 mg/dL was used as the threshold to define an abnormal GCT result. Carpenter and Coustan criteria were used to evaluate the OGTT results. Seventy-four women with normal GCT values comprised group I. Ninety-nine women with one elevated 100 g OGTT value who were given a caloric diet and 102 women with one elevated OGTT value in group III who received antenatal care with no special diet were randomly assigned to groups II and III, respectively. All women were followed up until the end of pregnancy. Poor maternal outcome was defined as: cesarean delivery performed due to cephalopelvic disproportion, failure to progress or fetal distress, preeclampsia, and/or preterm labor. Poor perinatal outcome was defined as: small for gestational age, large for gestational age or admission to a neonatal intensive care unit. The groups were compared in terms of maternal and perinatal outcomes. The rates of macrosomia and large for gestational age incidence were significantly higher in group III as compared to groups I and II. When we examined the multivariate effects of the risk factors considered to be predictive of poor maternal outcomes, group III was the only statistically significant risk factor (OR=3.90, 95% CI:1.95- 7.84; p=<0.001). In terms of poor perinatal outcome, one elevated OGTT value (group III) was the only significant risk factor (OR=2.92, 95% CI:1.56-5.46; p=<0.001). Women with one elevated OGTT value benefit from a structured program of diet therapy aimed to reduce adverse maternal and perinatal outcomes.

  4. What Happens to Blood Glucose Concentrations After Oral Treatment for Neonatal Hypoglycemia?

    PubMed

    Harris, Deborah L; Gamble, Greg D; Weston, Philip J; Harding, Jane E

    2017-07-11

    To determine the change in blood glucose concentration after oral treatment of infants with hypoglycemia in the first 48 hours after birth. We analyzed data from 227 infants with hypoglycemia (blood glucose <46.8 mg/dL, 2.6 mmol/L) born at a tertiary hospital who experienced 295 episodes of hypoglycemia. Blood glucose concentrations were measured (glucose oxidase) within 90 minutes after randomization to dextrose or placebo gel plus feeding with formula, expressed breast milk, or breast feeding. The overall mean increase in blood glucose concentration was 11.7 mg/dL (95% CI 10.4-12.8). The increase was greater after buccal dextrose gel than after placebo gel (+3.0 mg/dL; 95% CI 0.7-5.3; P = .01) and greater after infant formula than after other feedings (+3.8 mg/dL; 95% CI 0.8-6.7; P = .01). The increase in blood glucose concentration was not affected by breast feeding (+2.0 mg/dL; 95% CI -0.3 to 44.2; P = .09) or expressed breast milk (-1.4 mg/dL; 95% CI -3.7 to 0.9; P = .25). However, breast feeding was associated with reduced requirement for repeat gel treatment (OR = 0.52; 95% CI 0.28-0.94; P = .03). Treatment of infants with hypoglycemia with dextrose gel or formula is associated with increased blood glucose concentration and breast feeding with reduced need for further treatment. Dextrose gel and breast feeding should be considered for first-line oral treatment of infants with hypoglycemia. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Scots pine responses to elevated temperature and carbon dioxide concentration: growth and wood properties.

    PubMed

    Kilpeläinen, Antti; Peltola, Heli; Ryyppö, Aija; Kellomäki, Seppo

    2005-01-01

    Growth and wood properties of 20-year-old Scots pine (Pinus sylvestris L.) trees were studied for 6 years in 16 closed chambers providing a factorial combination of two temperature regimes (ambient and elevated) and two carbon dioxide concentrations ([CO2]) (ambient and twice ambient). The elevation of temperature corresponded to the predicted effect at the site of a doubling in atmospheric [CO2]. Annual height and radial growth and wood properties were analyzed during 1997-2002. Physical wood properties analyzed included early- and latewood widths and their proportions, intra-ring wood densities, early- and latewood density and mean fiber length. Chemical wood properties analyzed included concentrations of acetone-soluble extractives, lignin, cellulose and hemicellulose. There were no significant treatment effects on height growth during the 6-year study. Elevated [CO2] increased ring width by 66 and 47% at ambient and elevated temperatures, respectively. At ambient [CO2], elevated temperature increased ring width by 19%. Increased ring width in response to elevated [CO2] resulted from increases in both early- and latewood width; however, there was no effect of the treatments on early- and latewood proportions. Mean wood density, earlywood density and fiber length increased in response to elevated temperature. The chemical composition of wood was affected by elevated [CO2], which reduced the cellulose concentration, and by elevated temperature, which reduced the concentration of acetone-soluble extractives. Thus, over the 6-year period, radial growth was significantly increased by elevated [CO2], and some wood properties were significantly affected by elevated temperature or elevated [CO2], or both, indicating that climate change may affect the material properties of wood.

  6. A non-invasive photoacoustic and ultrasonic method for the measurement of glucose solution concentration

    NASA Astrophysics Data System (ADS)

    Zhao, Siwei; Tao, Wei; He, Qiaozhi; Zhao, Hui; Cao, Wenwu

    2017-03-01

    Diabetes mellitus (DM) is a chronic disease affecting nearly 400 million people worldwide. In order to manage the disease, patients need to monitor the blood glucose level by puncturing the finger several times a day, which is uncomfortable and inconvenient. We present here a potential non-invasive monitoring method based on the velocity of ultrasonic waves generated in glucose solution by the photoacoustic principal, which can recognize the glucose concentration down to 20mg/dL. In order to apply this method to warm bodies, we carefully designed the experiment and performed measurements from 30 °C to 50 °C to generate a set of calibration curves, which may be used by engineers to build devices. Most importantly, we have theoretically explained the relationship between the compressibility and the glucose concentration. Our results show that the compressibility of solution decreases with the glucose concentration, which clarified the controversy between theory and experiment results in the literature. The derived formula is generally validity, which can be used to nondestructively measure solution concentration for other types of solutions using photoacoustic principle.

  7. [Adiponectin, insulin and glucose concentrations in overweight and obese subjects after a complex carbohydrates (fiber) diet].

    PubMed

    González Rodríguez, Dora Cristina; Solano R, Liseti; González Martínez, Julio César

    2009-09-01

    Adiponectin one of the cytokines secreted by the adipose tissue that regulates the energetic metabolism through glucose and insulin interactions, stimulates the oxidation of fatty acids, reduces the plasmatic triglycerides and improves glucose metabolism by increasing insulin sensibility. Serum concentrations of adiponectin, insulin and glucose were assessed in order to establish association to weight loss after a dietary regime based on consumption of complex carbohydrates (fiber) during six weeks. Overweight and obese subjects (n=56) were studied by anthropometry. Adiponectin and insulin were measured by ELISA and glucose by Colorimetry. Data was analyzed by non parametric tests to compare independent or related samples. 12 men and 44 women, aged 20 to 55 years, 17 overweight and 39 obese were assessed. Adiponectin concentration was significantly low at basal determination in all the subjects (4,47 +/- 1,64); being higher in women (4,62 +/- 1,57 vs 3,93 +/- 1,86 microU/mL in men), while glucose and insulin values were at normal range (82,46 +/-26,51 mg/dL and 14,12 +/- 10,15 microU/mL) respectively with no significant differences for sex. Overweight subjects had significantly higher adiponectin concentrations than obese participants, at all measurements. Dietary regime promoted significant increase in adiponectin concentration at second and sixth week, with a negative correlation to body mass index and gender as they lost body weight.

  8. The association between HbA1c, fasting glucose, 1-hour glucose and 2-hour glucose during an oral glucose tolerance test and cardiovascular disease in individuals with elevated risk for diabetes.

    PubMed

    Lind, Marcus; Tuomilehto, Jaakko; Uusitupa, Matti; Nerman, Olle; Eriksson, Johan; Ilanne-Parikka, Pirjo; Keinänen-Kiukaanniemi, Sirkka; Peltonen, Markku; Pivodic, Aldina; Lindström, Jaana

    2014-01-01

    To determine the association between HbA1c, fasting plasma glucose (FPG), 1-hour (1 hPG) and 2-hour (2 hPG) glucose after an oral glucose tolerance test (OGTT) and cardiovascular disease in individuals with elevated risk for diabetes. We studied the relationship between baseline, updated mean and updated (last) value of HbA1c, FPG, 1 hPG and 2 hPG after an oral 75 g glucose tolerance test (OGTT) and acute CVD events in 504 individuals with impaired glucose tolerance (IGT) at baseline enrolled in the Finnish Diabetes Prevention Study. Follow-up of clinical trial. 504 individuals with IGT were followed with yearly evaluations with OGTT, FPG and HbA1c. Relative risk of CVD. Over a median follow-up of 9.0 years 34 (6.7%) participants had a CVD event, which increased to 52 (10.3%) over a median follow-up of 13.0 years when including events that occurred among participants following a diagnosis of diabetes. Updated mean HbA1c, 1 hPG and 2 hPG, HR per 1 unit SD of 1.57 (95% CI 1.16 to 2.11), p = 0.0032, 1.51 (1.03 to 2.23), p = 0.036 and 1.60 (1.10 to 2.34), p = 0.014, respectively, but not FPG (p = 0.11), were related to CVD. In analyses of the last value prior to the CVD event the same three glycaemic measurements were associated with the CVD events, with HRs per 1 unit SD of 1.45 (1.06 to 1.98), p = 0.020, 1.55 (1.04 to 2.29), p = 0.030 and 2.19 (1.51 to 3.18), p<0.0001, respectively but only 2 hPG remained significant in pairwise comparisons. Including the follow-up period after diabetes onset updated 2 hPG (p = 0.003) but not updated mean HbA1c (p = 0.08) was related to CVD. Current 2 hPG level in people with IGT is associated with increased risk of CVD. This supports its use in screening for prediabetes and monitoring glycaemic levels of people with prediabetes.

  9. Influence of various carbohydrate sources on postprandial glucose, insulin and NEFA concentrations in obese cats.

    PubMed

    Mori, A; Ueda, K; Lee, P; Oda, H; Ishioka, K; Sako, T

    2016-01-01

    Carbohydrate is an important source of energy, which can significantly affect postprandial blood glucose and insulin levels in cats. In healthy animals, this is not a big concern; however, in obese and diabetic animals, this is an important detail. In the present study, the impact of four different carbohydrate sources (glucose, maltose, corn starch, and trehalose) on short-term post-prandial serum glucose, insulin, and non-esterified fatty acid (NEFA) concentrations was investigated with four obese cats. Each of the carbohydrate sources was added to a commercial wet food diet for feeding the animals. A significant difference was observed in postprandial glucose, insulin, and NEFA area under the curve (AUC) values between each carbohydrate source in obese cats. Furthermore, glucose and maltose induced the highest postprandial glucose and insulin AUC values, whereas trehalose induced the lowest postprandial glucose and insulin AUC value amongst all carbohydrate sources, respectively, in obese cats. However, trehalose has a higher risk of inducing side effects, such as diarrhea, as compared to other carbohydrate sources. As such, different carbohydrate sources appear to have a very significant impact on post-prandial glycemia and subsequent insulin requirement levels in obese cats. These results might be useful when selecting a prescription diet for obese or diabetic cats. In addition, maltose appears to be capable of inducing experimentally evoked postprandial hyperglycemia in obese cats, which may serve as a good tool for use to check the impact and effectiveness of newly developed oral hypoglycemic drugs or supplements for cats in future experiments.

  10. An In-Line Photonic Biosensor for Monitoring of Glucose Concentrations

    PubMed Central

    Al-Halhouli, Ala'aldeen; Demming, Stefanie; Alahmad, Laila; LIobera, Andreu; Büttgenbach, Stephanus

    2014-01-01

    This paper presents two PDMS photonic biosensor designs that can be used for continuous monitoring of glucose concentrations. The first design, the internally immobilized sensor, consists of a reactor chamber, micro-lenses and self-alignment structures for fiber optics positioning. This sensor design allows optical detection of glucose concentrations under continuous glucose flow conditions of 33 μL/h based on internal co-immobilization of glucose oxidase (GOX) and horseradish peroxidase (HRP) on the internal PDMS surface of the reactor chamber. For this design, two co-immobilization methods, the simple adsorption and the covalent binding (PEG) methods were tested. Experiments showed successful results when using the covalent binding (PEG) method, where glucose concentrations up to 5 mM with a coefficient of determination (R2) of 0.99 and a limit of detection of 0.26 mM are detectable. The second design is a modified version of the internally immobilized sensor, where a microbead chamber and a beads filling channel are integrated into the sensor. This modification enabled external co-immobilization of enzymes covalently onto functionalized silica microbeads and allows binding a huge amount of HRP and GOX enzymes on the microbeads surfaces which increases the interaction area between immobilized enzymes and the analyte. This has a positive effect on the amount and rate of chemical reactions taking place inside the chamber. The sensor was tested under continuous glucose flow conditions and was found to be able to detect glucose concentrations up to 10 mM with R2 of 0.98 and a limit of detection of 0.7 mM. Such results are very promising for the application in photonic LOC systems used for online analysis. PMID:25157552

  11. The salivary microbiome is altered in the presence of a high salivary glucose concentration

    PubMed Central

    Hartman, Mor-Li; Shi, Ping; Hasturk, Hatice; Yaskell, Tina; Vargas, Jorel; Song, Xiaoqing; Cugini, Maryann; Barake, Roula; Alsmadi, Osama; Al-Mutawa, Sabiha; Ariga, Jitendra; Soparkar, Pramod; Behbehani, Jawad; Behbehani, Kazem

    2017-01-01

    Background Type II diabetes (T2D) has been associated with changes in oral bacterial diversity and frequency. It is not known whether these changes are part of the etiology of T2D, or one of its effects. Methods We measured the glucose concentration, bacterial counts, and relative frequencies of 42 bacterial species in whole saliva samples from 8,173 Kuwaiti adolescents (mean age 10.00 ± 0.67 years) using DNA probe analysis. In addition, clinical data related to obesity, dental caries, and gingivitis were collected. Data were compared between adolescents with high salivary glucose (HSG; glucose concentration ≥ 1.0 mg/d, n = 175) and those with low salivary glucose (LSG, glucose concentration < 0.1 mg/dL n = 2,537). Results HSG was associated with dental caries and gingivitis in the study population. The overall salivary bacterial load in saliva decreased with increasing salivary glucose concentration. Under HSG conditions, the bacterial count for 35 (83%) of 42 species was significantly reduced, and relative bacterial frequencies in 27 species (64%) were altered, as compared with LSG conditions. These alterations were stronger predictors of high salivary glucose than measures of oral disease, obesity, sleep or fitness. Conclusions HSG was associated with a reduction in overall bacterial load and alterations to many relative bacterial frequencies in saliva when compared with LSG in samples from adolescents. We propose that hyperglycemia due to obesity and/or T2D results in HSG and subsequent acidification of the oral environment, leading to a generalized perturbation in the oral microbiome. This suggests a basis for the observation that hyperglycemia is associated with an increased risk of dental erosion, dental caries, and gingivitis. We conclude that HSG in adolescents may be predicted from salivary microbial diversity or frequency, and that the changes in the oral microbial composition seen in adolescents with developing metabolic disease may the consequence

  12. The Effects of Blood Glucose Concentration on the Shivering Threshold in Rabbits.

    PubMed

    Ino, Hirofumi; Masamune, Taishi; Sato, Hiroaki; Okuyama, Katsumi; Wada, Keiichi; Iwashita, Hironobu; Ishiyama, Tadahiko; Oguchi, Takeshi; Sessler, Daniel I; Matsukawa, Takashi

    2015-08-01

    Hyperglycemia is common in critically ill and surgical patients, as are core temperature disturbances. The effect of hyperglycemia on thermoregulatory defenses remains unknown. We determined the effect of blood glucose concentration on the shivering threshold in rabbits. Twenty-seven rabbits lightly anesthetized with isoflurane were randomly assigned to infusions of (1) saline, (2) insulin titrated to produce blood glucose concentrations 60 to 100 mg/dL, or (3) 50% dextrose titrated to produce blood glucose concentrations 200 to 300 mg/dL. Core temperature was reduced at a rate of 2 to 3°C/h by perfusing water at 10°C through a plastic tube positioned in the colon. Cooling continued until shivering was observed by an investigator blinded to treatment or until esophageal (core) temperature reached 34°C. Core temperatures at the onset of shivering defined the threshold. All analyses were conducted using SAS version 9.3 (SAS Institute Inc., Cary, NC). Rabbits given saline shivered at 37.2 ± 0.5°C (mean ± SD). Rabbits given insulin shivered at 36.3 ± 1.1°C. Rabbits given dextrose shivered at 38.0 ± 0.6°C. The shivering threshold increased as a function of blood glucose concentration: shivering threshold (°C) = 0.009 [blood glucose concentration (mg/dL)] + 35.6, r = 0.53. The shivering threshold thus increased approximately 1°C for each 100 mg/dL increase in blood glucose concentration. Hyperglycemia increases the threshold for shivering, whereas hypoglycemia lowers the threshold on rabbits.

  13. Elevated CO2 concentration effects on reproductive phenology and seed yield among soybean cultivars

    USDA-ARS?s Scientific Manuscript database

    Seed yield increases in soybeans caused by increased growth at elevated carbon dioxide concentrations primarily result from increased numbers of pods. However, reasons for differences among cultivars in the increases in pod number caused by elevated carbon dioxide are not clear. In experiments in ...

  14. Differential Responses of Plasma Adropin Concentrations To Dietary Glucose or Fructose Consumption In Humans.

    PubMed

    Butler, Andrew A; St-Onge, Marie-Pierre; Siebert, Emily A; Medici, Valentina; Stanhope, Kimber L; Havel, Peter J

    2015-10-05

    Adropin is a peptide hormone encoded by the Energy Homeostasis Associated (ENHO) gene whose physiological role in humans remains incompletely defined. Here we investigated the impact of dietary interventions that affect systemic glucose and lipid metabolism on plasma adropin concentrations in humans. Consumption of glucose or fructose as 25% of daily energy requirements (E) differentially affected plasma adropin concentrations (P < 0.005) irrespective of duration, sex or age. Glucose consumption reduced plasma adropin from 3.55 ± 0.26 to 3.28 ± 0.23 ng/ml (N = 42). Fructose consumption increased plasma adropin from 3.63 ± 0.29 to 3.93 ± 0.34 ng/ml (N = 45). Consumption of high fructose corn syrup (HFCS) as 25% E had no effect (3.43 ± 0.32 versus 3.39 ± 0.24 ng/ml, N = 26). Overall, the effect of glucose, HFCS and fructose on circulating adropin concentrations were similar to those observed on postprandial plasma triglyceride concentrations. Furthermore, increases in plasma adropin levels with fructose intake were most robust in individuals exhibiting hypertriglyceridemia. Individuals with low plasma adropin concentrations also exhibited rapid increases in plasma levels following consumption of breakfasts supplemented with lipids. These are the first results linking plasma adropin levels with dietary sugar intake in humans, with the impact of fructose consumption linked to systemic triglyceride metabolism. In addition, dietary fat intake may also increase circulating adropin concentrations.

  15. Increased Accumulation of Carbohydrates and Decreased Photosynthetic Gene Transcript Levels in Wheat Grown at an Elevated CO2 Concentration in the Field.

    PubMed Central

    Nie, G.; Hendrix, D. L.; Webber, A. N.; Kimball, B. A.; Long, S. P.

    1995-01-01

    Repression of photosynthetic genes by increased soluble carbohydrate concentrations may explain acclimation of photosynthesis to elevated CO2 concentration. This hypothesis was examined in a field crop of spring wheat (Triticum aestivum L.) grown at both ambient (approximately 360 [mu]mol mol-1) and elevated (550 [mu]mol mol-1) atmospheric CO2 concentrations using free-air CO2 enrichment at Maricopa, Arizona. The correspondence of steady-state levels of mRNA transcripts (coding for the 83-kD photosystem I apoprotein, sedoheptulose-1,7-bisphosphatase, phosphoribulokinase, phosphoglycerokinase, and the large and small subunits of ribulose-1,5-bisphosphate carboxylase/oxygenase) with leaf carbohydrate concentrations (glucose-6-phosphate, glucose, fructose, sucrose, fructans, and starch) was examined at different stages of crop and leaf development and through the diurnal cycle. Overall only a weak correspondence between increased soluble carbohydrate concentrations and decreased levels for nuclear gene transcripts was found. The difference in soluble carbohydrate concentration between leaves grown at elevated and current ambient CO2 concentrations diminished with crop development, whereas the difference in transcript levels increased. In the flag leaf, soluble carbohydrate concentrations declined markedly with the onset of grain filling; yet transcript levels also declined. The results suggest that, whereas the hypothesis may hold well in model laboratory systems, many other factors modified its significance in this field wheat crop. PMID:12228521

  16. [Glycated haemoglobin may in future be reported as estimated mean blood glucose concentration--secondary publication].

    PubMed

    Borg, Rikke; Nerup, Jørn; Nathan, David M; Kuenen, Judith; Zheng, Hui; Schoenfeld, David; Heine, Robert J

    2009-11-02

    Glycated haemoglobin (HbA 1c ) is widely used to determine levels of chronic glycaemia, to judge the adequacy of diabetes treatment and to adjust therapy. HbA 1c results are expressed as the percentage of HbA that is glycated. Day-to-day management is guided by self-monitoring of capillary glucose concentrations in mmol/l. The ADAG study determined the relationship between HbA 1c and average glucose concentration (AG) and concluded that for most patients with diabetes, HbA 1c can - with reasonable precision - be expressed as an estimated AG in the same units as self-monitoring.

  17. Freeze-thawing behaviour of highly concentrated aqueous alkali chloride-glucose systems.

    PubMed

    Kajiwara, K; Motegi, A; Murase, N

    2001-01-01

    The freeze-thawing behaviour of highly concentrated aqueous alkali chloride-glucose systems was investigated by differential scanning calorimetry (DSC). In the aqueous NaCl-glucose solution system, single or double glass transitions followed by the corresponding devitrification exotherms were observed during rewarming. In the aqueous KCl-glucose solution system, on the other hand, a single glass transition followed by an exotherm was observed during rewarming. The presence of double glass transitions observed for a certain composition of the aqueous NaCl-glucose solution was taken as an evidence for the liquid-liquid immiscibility at low temperatures. Two kinds of crystallisation accompanied by exotherms during rewarming were identified by X-ray diffraction as ice and ice/NaCl x 2H(2)O, or ice/KCl eutectic component.

  18. Severe ascites with hypothyroidism and elevated CA125 concentration: a case report.

    PubMed

    Kimura, Ryosuke; Imaeda, Kenro; Mizuno, Tatsuo; Wakami, Kazuko; Yamada, Kazuhiro; Okayama, Naotsuka; Kamiya, Yoshinobu; Joh, Takashi

    2007-12-01

    Ascites caused by hypothyroidism is rare and the pathogenesis is unclear. Several reports have presented cases of progressive ascites with hypothyroidism and elevated tumor markers. We report a 31-year-old female case with massive ascites and elevated serum CA 125 concentrations. The patient had no typical feature of hypothyroidism except an accumulation of ascitic fluid which showed elevated total protein concentration and a high serum-ascites albumin gradient (SAAG). There was no finding of malignancy. Following thyroid hormone replacement, the ascites was completely resolved accompanied by reduced concentrations of serum CA125. In general, primary hypothyroidism with ascites presents with coexisting massive pericardial or pleural effusion. The massive ascites and increased serum CA125 concentrations may have led us to make the incorrect diagnosis of ovarian malignancy. The evaluation of thyroid function is useful to determine the pathology of high-protein ascites or elevated tumor markers, and ascites may be treatable by thyroid replacement therapy.

  19. Exposure to High Glucose Concentration Decreases Cell Surface ABCA1 and HDL Biogenesis in Hepatocytes.

    PubMed

    Tsujita, Maki; Hossain, Mohammad Anwar; Lu, Rui; Tsuboi, Tomoe; Okumura-Noji, Kuniko; Yokoyama, Shinji

    2017-04-19

    To study atherosclerosis risk in diabetes, we investigated ATP-binding cassette transporter A1 (ABCA1) expression and high-density lipoprotein (HDL) biogenesis in the liver and hepatocytes under hyperglycemic conditions. In streptozotocin-induced diabetic mice, plasma HDL decreased while ABCA1 protein increased without changing its mRNA in the liver, only in the animals that responded to the treatment to show hypoinsulinemia and fasting hyperglycemia but not in the poor responders not showing those. To study the mechanism for this finding, hepatocytes were isolated from the control and diabetic mice, and they showed no difference in expression of ABCA1 protein, its mRNA, and HDL biogenesis in 1 g/l d-glucose but showed decreased HDL biogenesis in 4.5 g/l d-glucose although ABCA1 protein increased without change in its mRNA. Similar findings were confirmed in HepG2 cells with d-glucose but not with l-glucose. Thus, these cell models reproduced the in vivo findings in hyperglycemia. Labeling of cell surface protein revealed that surface ABCA1 decreased in high concentration of d-glucose in HepG2 cells despite the increase of cellular ABCA1 while not with l-glucose. Immunostaining of ABCA1 in HepG2 cells demonstrated the decrease of surface ABCA1 but increase of intracellular ABCA1 with high d-glucose. Clearance of ABCA1 was retarded both in primary hepatocytes and HepG2 cells exposed to high d-glucose but not to l-glucose, being consistent with the decrease of surface ABCA1. It is suggested that localization of ABCA1 to the cell surface is decreased in hepatocytes in hyperglycemic condition to cause decrease of HDL biogenesis.

  20. Effects of sitagliptin on plasma incretin concentrations after glucose administration through an esophagostomy tube or feeding in healthy cats.

    PubMed

    Nishii, N; Takashima, S; Iguchi, A; Murahata, Y; Matsuu, A; Hikasa, Y; Kitagawa, H

    2014-10-01

    We investigated the effect of sitagliptin, a dipeptidyl peptidase 4 inhibitor, on plasma incretin concentrations after glucose administration through an esophagostomy tube or feeding in healthy cats. Six cats were used for the glucose administration experiment and 5 cats were used for the feeding experiment. Glucose administration through an esophagostomy tube increased plasma glucagon-like peptide 1 (GLP-1) concentrations by 6-fold, whereas plasma glucose-dependent insulinotropic polypeptide (GIP) concentrations did not change. Feeding increased both plasma GLP-1 concentrations by 1.5-fold and GIP concentrations by 4.6-fold. Sitagliptin was administered through an esophagostomy tube (25 and 50 mg per cat) in the glucose administration experiment and orally (25 mg per cat) in the feeding experiment. Sitagliptin treatment potentiated the GLP-1 response to glucose by 1.5-fold (P < 0.05). In addition, postprandial plasma GLP-1 concentration was higher by 2-fold when sitagliptin was administered (P < 0.05). In contrast, administration of sitagliptin did not affect plasma GIP concentrations after glucose administration or feeding. Sitagliptin enhanced insulin secretion following glucose administration by 1.5-fold (P < 0.05); however, it did not influence the plasma glucose concentration. Furthermore, sitagliptin had no effect on the postprandial plasma glucose and insulin concentrations. In conclusion, this study provides no evidence that sitagliptin is beneficial for management of feline diabetes mellitus. Copyright © 2014 Elsevier Inc. All rights reserved.

  1. Photoacoustic measurement for glucose solution concentration based on tunable pulsed laser induced ultrasound

    NASA Astrophysics Data System (ADS)

    Ren, Zhong; Liu, Guodong; Huang, Zhen; Zhao, Dengji

    2012-12-01

    Noninvasive measurement of blood glucose concentration (BGC) has become a research hotspot. BGC measurement based on photoacoustic spectroscopy (PAS) was employed to detect the photoacoustic (PA) signal of blood glucose due to the advantages of avoiding the disturbance of optical scattering. In this paper, a set of custom-built BGC measurement system based on tunable optical parametric oscillator (OPO) pulsed laser and ultrasonic transducer was established to test the PA response effect of the glucose solution. In the experiments, we successfully acquired the time resolved PA signals of distilled water and glucose aqueous solution, and the PA peak-to-peak values(PPV) were gotten under the condition of excitated pulsed laser with changed wavelength from 1340nm to 2200nm by increasing interval of 10nm, the optimal characteristic wavelengths of distilled water and glucose solution were determined. Finally, to get the concentration prediction error, we used the linear fitting of ordinary least square (OLS) algorithm to fit the PPV of 1510nm, and we got the predicted concentration error was about 0.69mmol/L via the fitted linear equation. So, this system and scheme have some values in the research of noninvasive BGC measurement.

  2. Measurement of glucose concentration in turbid media by the polarization state of backscattered laser light

    NASA Astrophysics Data System (ADS)

    Kafidova, Galina A.; Aksenov, Evgenii T.; Petrov, Victor M.

    2013-06-01

    Biological tissues, including human skin, are complex objects for optical measurements. Because of its multi-component structure, they are characterized by a combined response to various dynamic changes, both inside and outside of the biological object. Change of glucose concentration in the blood leads to a number of processes, which affect the light scattering properties of the skin and subcutaneous layers, herewith scattering coefficient and the polarization of the scattered light vary. The possibility of non-invasive blood glucose detection by parameters of backscattered laser light was experimentally demonstrated. Degree of polarization of light scattered by human skin and model objects was registered and dependence of the polarization state of backscattered radiation on the glucose concentration in the human blood was shown. A laboratory model of a differential polarimeter, which allows registering the parameters of the polarized radiation scattered by human skin and glucose containing models was developed. Using the developed model, model and full-scale experiments were conducted. In the model experiments, the light scattered in the forward and backwards direction by the following model objects: a 20% solution of milk and a 50% solution of whole human blood was investigated. The ability of the developed sensor to noninvasively detect the concentration of glucose in the blood was demonstrated.

  3. Avian, salamander, and forest floor mercury concentrations increase with elevation in a terrestrial ecosystem.

    PubMed

    Townsend, Jason M; Driscoll, Charles T; Rimmer, Christopher C; McFarland, Kent P

    2014-01-01

    High-elevation ecosystems of the northeastern United States are vulnerable to deposition and environmental accumulation of atmospheric pollutants, yet little work has been done to assess mercury (Hg) concentrations in organisms occupying montane ecosystems. The authors present data on Hg concentrations in ground-foraging insectivorous songbirds, a terrestrial salamander, and forest floor horizons sampled along a forested elevational gradient from 185 m to 1273 m in the Catskill Mountains, New York, USA. Mean Hg concentrations in Catharus thrushes and the salamander Plethodon cinereus increased with elevation, as did Hg concentrations in all forest floor horizons. Mean Hg concentrations in organic soils at approximately 1200 m elevation (503.5 ± 17.7 ng/g, dry wt) were 4.4-fold greater than those at approximately 200 m. Montane ecosystems of the northeastern United States, and probably elsewhere, are exposed to higher levels of atmospheric Hg deposition as reflected in accumulation patterns in the forest floor and associated high-elevation fauna. This information can be used to parameterize and test Hg transport and bioaccumulation models of landscape-specific patterns and may serve as a monitoring tool for decision makers considering future controls on Hg emissions. Further investigation is needed into the potential effects of increased Hg concentrations on high-elevation fauna. © 2013 SETAC.

  4. Effects of rice bran oil on plasma lipid concentrations, lipoprotein composition, and glucose dynamics in mares.

    PubMed

    Frank, N; Andrews, F M; Elliott, S B; Lew, J; Boston, R C

    2005-11-01

    Plasma lipid concentrations, lipoprotein composition, and glucose dynamics were measured and compared between mares fed diets containing added water, corn oil (CO), refined rice bran oil (RR), or crude rice bran oil (CR) to test the hypothesis that rice bran oil lowers plasma lipid concentrations, alters lipoprotein composition, and improves insulin sensitivity in mares. Eight healthy adult mares received a basal diet fed at 1.5 times the DE requirement for maintenance and each of the four treatments according to a repeated 4 x 4 Latin square design consisting of four 5-wk feeding periods. Blood samples were collected for lipid analysis after mares were deprived of feed overnight at 0 and 5 wk. Glucose dynamics were assessed at 0 and 4 wk in fed mares by combined intravenous glucose-insulin tolerance tests. Plasma glucose and insulin concentrations were measured, and estimated values of insulin sensitivity (SI), glucose effectiveness, and net insulin response were obtained using the minimal model. Mean BW increased (P = 0.014) by 29 kg (range = 10 to 50 kg) over 5 wk. Mean plasma concentrations of NEFA, triglyceride (TG), and very low-density lipoprotein (VLDL) decreased (P < 0.001) by 55, 30, and 39%, respectively, and plasma high-density lipoprotein and total cholesterol (TC) concentrations increased (P < 0.001) by 15 and 12%, respectively, over 5 wk. Changes in plasma NEFA (r = 0.58; P < 0.001) and TC (r = 0.44; P = 0.013) concentrations were positively correlated with weight gain over 5 wk. Lipid components of VLDL decreased (P < 0.001) in abundance over 5 wk, whereas the relative protein content of VLDL increased by 39% (P < 0.001). Addition of oil to the basal diet instead of water lowered plasma NEFA and TG concentrations further (P = 0.002 and 0.020, respectively) and increased plasma TC concentrations by a greater magnitude (P = 0.072). However, only plasma TG concentrations and VLDL free cholesterol content were affected (P = 0.024 and 0.009, respectively

  5. Dietary flaxseed lignan extract lowers plasma cholesterol and glucose concentrations in hypercholesterolaemic subjects.

    PubMed

    Zhang, Wei; Wang, Xiaobing; Liu, Yi; Tian, Haimei; Flickinger, Brent; Empie, Mark W; Sun, Sam Z

    2008-06-01

    Lignans, derived from flaxseed, are phyto-oestrogens being increasingly studied for their health benefits. An 8-week, randomised, double-blind, placebo-controlled study was conducted in fifty-five hypercholesterolaemic subjects, using treatments of 0 (placebo), 300 or 600 mg/d of dietary secoisolariciresinol diglucoside (SDG) from flaxseed extract to determine the effect on plasma lipids and fasting glucose levels. Significant treatment effects were achieved (P < 0.05 to < 0.001) for the decrease of total cholesterol (TC), LDL-cholesterol (LDL-C) and glucose concentrations, as well as their percentage decrease from baseline. At weeks 6 and 8 in the 600 mg SDG group, the decreases of TC and LDL-C concentrations were in the range from 22.0 to 24.38 % respectively (all P < 0.005 compared with placebo). For the 300 mg SDG group, only significant differences from baseline were observed for decreases of TC and LDL-C. A substantial effect on lowering concentrations of fasting plasma glucose was also noted in the 600 mg SDG group at weeks 6 and 8, especially in the subjects with baseline glucose concentrations > or = 5.83 mmol/l (lowered 25.56 and 24.96 %; P = 0.015 and P = 0.012 compared with placebo, respectively). Plasma concentrations of secoisolariciresinol (SECO), enterodiol (ED) and enterolactone were all significantly raised in the groups supplemented with flaxseed lignan. The observed cholesterol-lowering values were correlated with the concentrations of plasma SECO and ED (r 0.128-0.302; P < 0.05 to < 0.001). In conclusion, dietary flaxseed lignan extract decreased plasma cholesterol and glucose concentrations in a dose-dependent manner.

  6. Substrate inhibition kinetics of Saccharomyces cerevisiae in fed-batch cultures operated at constant glucose and maltose concentration levels.

    PubMed

    Papagianni, M; Boonpooh, Y; Mattey, M; Kristiansen, B

    2007-04-01

    Fed-batch culture is the mode of operation of choice in industrial baker's yeast fermentation. The particular mode of culture, operated at stable glucose and maltose concentration levels, was employed in this work in order to estimate important kinetic parameters in a process mostly described in the literature as batch or continuous culture. This way, the effects of a continuously falling sugar level during a batch process were avoided and therefore the effects of various (stable) sugar levels on growth kinetics were evaluated. Comparing the kinetics of growth and the inhibition by the substrate in cultures grown on glucose, which is the preferential sugar source for Saccharomyces cerevisiae, and maltose, the most common sugar source in industrial media for baker's yeast production, a milder inhibition effect by the substrate in maltose-grown cells was observed, as well as a higher yield coefficient. The observed sugar inhibition effect in glucostat cultures was taken into account in modeling substrate inhibition kinetics. The inhibition coefficient Ki increased with increasing sugar concentration levels, but it appeared to be unaffected by the type of substrate and almost equal for both substrates at elevated concentration levels.

  7. Effect of Vanadate on Elevated Blood Glucose and Depressed Cardiac Performance of Diabetic Rats

    NASA Astrophysics Data System (ADS)

    Heyliger, Clayton E.; Tahiliani, Arun G.; McNeill, John H.

    1985-03-01

    The trace element vanadium has an unclear biological function. Vanadate, an oxidized form of vanadium, appears to have an insulin-like action. The effect of vanadate on blood glucose and cardiac performance was assessed in female Wistar rats 6 weeks after they were made diabetic with streptozotocin. When vanadate was administered for a 4-week period to the diabetic rats, their blood glucose was not significantly different from that of nondiabetic controls despite a low serum insulin. In contrast, blood glucose was increased about threefold in the diabetic rats that were not treated with vanadate; these rats also had low insulin levels. Cardiac performance was depressed in the untreated diabetic animals, but the cardiac performance of the vanadate-treated diabetic animals was not significantly different from that of nondiabetic controls. Thus vanadate controlled the high blood glucose and prevented the decline in cardiac performance due to diabetes.

  8. Elevated Glucose Oxidation, Reduced Insulin Secretion, and a Fatty Heart May Be Protective Adaptions in Ischemic CAD.

    PubMed

    Hannukainen, J C; Lautamäki, R; Mari, A; Pärkkä, J P; Bucci, M; Guzzardi, M A; Kajander, S; Tuokkola, T; Knuuti, J; Iozzo, P

    2016-07-01

    Insulin resistance, β-cell dysfunction, and ectopic fat deposition have been implicated in the pathogenesis of coronary artery disease (CAD) and type 2 diabetes, which is common in CAD patients. We investigated whether CAD is an independent predictor of these metabolic abnormalities and whether this interaction is influenced by superimposed myocardial ischemia. We studied CAD patients with (n = 8) and without (n = 14) myocardial ischemia and eight non-CAD controls. Insulin sensitivity and secretion and substrate oxidation were measured during fasting and oral glucose tolerance testing. We used magnetic resonance imaging/spectroscopy, positron emission and computerized tomography to characterize CAD, cardiac function, pericardial and abdominal adipose tissue, and myocardial, liver, and pancreatic triglyceride contents. Ischemic CAD was characterized by elevated oxidative glucose metabolism and a proportional decline in β-cell insulin secretion and reduction in lipid oxidation. Cardiac function was preserved in CAD groups, whereas cardiac fat depots were elevated in ischemic CAD compared to non-CAD subjects. Liver and pancreatic fat contents were similar in all groups and related with surrounding adipose masses or systemic insulin sensitivity. In ischemic CAD patients, glucose oxidation is enhanced and correlates inversely with insulin secretion. This can be seen as a mechanism to prevent glucose lowering because glucose is required in oxygen-deprived tissues. On the other hand, the accumulation of cardiac triglycerides may be a physiological adaptation to the limited fatty acid oxidative capacity. Our results underscore the urgent need of clinical trials that define the optimal/safest glycemic range in situations of myocardial ischemia.

  9. Effects of AMPK activation on lipolysis in primary rat adipocytes: studies at different glucose concentrations.

    PubMed

    Szkudelski, Tomasz; Szkudelska, Katarzyna

    2017-02-01

    Adipose tissue plays a key role in energy homeostasis. Adenosine monophosphate (AMP)-activated protein kinase (AMPK) is an important intracellular energy sensor. Effects of activation of AMPK by aminomidazole-4-carboxamide ribonucleotide (AICAR) on lipolysis in the rat adipocytes were determined in the presence of 3 or 12 mM glucose. Response to epinephrine or dibutyryl-cAMP was higher in the presence of 12 mM glucose. AICAR decreased lipolysis, also when glucose was replaced by alanine or succinate and without decrease in cAMP levels. AICAR attenuated epinephrine-induced decrease in adenosine triphosphate (ATP) levels, reduced glucose uptake and lactate release. These results indicate that short-term activation of AMPK by AICAR in the rat adipocytes inhibits lipolysis, due to changes in the final, followed by protein kinase A (PKA), steps of the lipolytic cascade and improves intracellular energy status. Similar effects of AICAR were observed in the presence of 3 and 12 mM glucose, which indicates that the AMPK system is operative at high glucose concentrations.

  10. Production of Mannitol from a High Concentration of Glucose by Candida parapsilosis SK26.001.

    PubMed

    Meng, Qing; Zhang, Tao; Wei, Wenting; Mu, Wanmeng; Miao, Ming

    2017-01-01

    A novel strain, SK26.001, which can produce mannitol from a high concentration of glucose without the addition of fructose, was isolated from sugarcane juice. This strain was identified as Candida parapsilosis based on 18S ribosomal RNA (rRNA) sequence analysis and the morphological and physiological-biochemical characteristics of the strain. Under optimized fermentation conditions, the mannitol concentration in shake flasks reached 68.5 g/L. When batch fermentation was performed, the fed glucose was completely consumed after 72 h, resulting in a final mannitol concentration of 80.3 g/L. Fed-batch fermentation was then performed with glucose feed. During the fed-batch process, ammonia water was added to maintain the pH at 4.0. The mannitol concentration in the fermenter reached 97.1 g/L after 120 h, with a total glucose consumption of 284 g/L.

  11. Biorefining of waste paper biomass: increasing the concentration of glucose by optimising enzymatic hydrolysis.

    PubMed

    Elliston, Adam; Collins, Samuel R A; Faulds, Craig B; Roberts, Ian N; Waldron, Keith W

    2014-04-01

    Waste copier paper is a potential substrate for the production of glucose relevant for manufacture of platform chemicals and intermediates, being composed of 51 % glucan. The yield and concentration of glucose arising from the enzymatic saccharification of solid ink-free copier paper as cellulosic substrate was studied using a range of commercial cellulase preparations. The results show that in all cellulase preparations examined, maximum hydrolysis was only achieved with the addition of beta-glucosidase, despite its presence in the enzyme mixtures. With the use of Accellerase® (cellulase), high substrate loading decreased conversion yield. However, this was overcome if the enzyme was added between 12.5 and 20 FPU g substrate(-1). Furthermore, this reaction condition facilitated continual stirring and enabled sequential additions (up to 50 % w/v) of paper to be made to the hydrolysis reaction, degrading nearly all (99 %) of the cellulose fibres and increasing the final concentration of glucose whilst simultaneously making high substrate concentrations achievable. Under optimal conditions (50 °C, pH 5.0, 72 h), digestions facilitate the production of glucose to much improved concentrations of up to 1.33 mol l(-1).

  12. Self-tuning GMV control of glucose concentration in fed-batch baker's yeast production.

    PubMed

    Hitit, Zeynep Yilmazer; Boyacioglu, Havva; Ozyurt, Baran; Ertunc, Suna; Hapoglu, Hale; Akay, Bulent

    2014-04-01

    A detailed system identification procedure and self-tuning generalized minimum variance (STGMV) control of glucose concentration during the aerobic fed-batch yeast growth were realized. In order to determine the best values of the forgetting factor (λ), initial value of the covariance matrix (α), and order of the Auto-Regressive Moving Average with eXogenous (ARMAX) model (n a, n b), transient response data obtained from the real process wereutilized. Glucose flow rate was adjusted according to the STGMV control algorithm coded in Visual Basic in an online computer connected to the system. Conventional PID algorithm was also implemented for the control of the glucose concentration in aerobic fed-batch yeast cultivation. Controller performances were examined by evaluating the integrals of squared errors (ISEs) at constant and random set point profiles. Also, batch cultivation was performed, and microorganism concentration at the end of the batch run was compared with the fed-batch cultivation case. From the system identification step, the best parameter estimation was accomplished with the values λ = 0.9, α = 1,000 and n a = 3, n b = 2. Theoretical control studies show that the STGMV control system was successful at both constant and random glucose concentration set profiles. In addition, random effects given to the set point, STGMV control algorithm were performed successfully in experimental study.

  13. A system for full Stokes vector measurement for low concentration glucose sensing

    NASA Astrophysics Data System (ADS)

    Phan, Quoc-Hung; Lo, Yu-Lung

    2016-03-01

    A high performance system for full Stokes vector measurements was developed. The proposed system comprised a polarization scanning generator (PSG) and a high accuracy polarization state analyzer (PSA) was proposed. The PSG generated full state of polarization of light by using voltage driven electro-optics modulator without using any mechanical moving parts. The PSA was employed to record the intensity of output polarized lights in a high speed manner. The accuracy of proposed system was 10-4 for all Stokes vector (S0, S1, S2, S3) measurements in the full state of polarization of lights. An application of proposed system for low concentration glucose in aqueous solution sensing with/without scattering effects was demonstrated. The sensitivity of the optical rotation angle of CB property to changes in the concentration of glucose sample was examined over the range from 0 to 0.5g/dl. The results confirm that the proposed system is able to detect glucose at fine concentration of 0.02g/dl. The linear variation of the optical rotation angle and different glucose concentration at different scattering effects was obtained. In general, the new measurement system proposed in this study provided a fast and reliable method to measure all Stokes vectors and its potential applications in biological sensing.

  14. In vitro determination of glucose concentration based on photoacoustic spectroscopy and chemometrics

    NASA Astrophysics Data System (ADS)

    Ren, Zhong; Liu, Guodong; Huang, Zhen

    2014-09-01

    Noninvasive blood glucose level (BGL) monitoring has recently become a research hotspot in the world. Photoacoustic spectroscopy is a well-established, hybrid and promising noninvasive technique, which has already drawn many researchers' attentions in recent years due to the advantage of overcoming the scattering light interference. As the preliminary exploration of photoacoustic BGL monitoring, a photoacoustic BGL monitoring set-up based on nanosecond pulsed laser with repetition rate of 20Hz and ultrasound transducer with central frequency of 9.55MHz was established in this paper. To explore the mechanism of the time resolved BGL photoacoustic signal, a series of in vitro experiments of glucose aqueous solutions were tested, the time resolved photoacoustic signals for different concentrations of glucose solutions under different output wavelengths were captured with the data average of 512 times. The peak-to-peak values of each solution were gotten at the wavelength interval of 10nm. Difference with the peak-to-peak value of pure water via subtractive spectroscopy, the characteristic wavelengths of glucose were gotten, and the optimum characteristic wavelengths were determined via data pre-processing and principle component analysis(PCA) algorithm, the calibration equation between concentration and the peak-to-peak value was gotten via multiple linear regression(MLR), and the calibration root mean square error(CRMSE) and the prediction root mean square error(PRMSE) of glucose level is all less than 10mg/dl under the correction equation.

  15. Elevational Variation in Soil Amino Acid and Inorganic Nitrogen Concentrations in Taibai Mountain, China

    PubMed Central

    Yang, Xin; Zhu, Lianfeng; Zhang, Junhua; Jin, Qianyu; Wu, Lianghuan

    2016-01-01

    Amino acids are important sources of soil organic nitrogen (N), which is essential for plant nutrition, but detailed information about which amino acids predominant and whether amino acid composition varies with elevation is lacking. In this study, we hypothesized that the concentrations of amino acids in soil would increase and their composition would vary along the elevational gradient of Taibai Mountain, as plant-derived organic matter accumulated and N mineralization and microbial immobilization of amino acids slowed with reduced soil temperature. Results showed that the concentrations of soil extractable total N, extractable organic N and amino acids significantly increased with elevation due to the accumulation of soil organic matter and the greater N content. Soil extractable organic N concentration was significantly greater than that of the extractable inorganic N (NO3−-N + NH4+-N). On average, soil adsorbed amino acid concentration was approximately 5-fold greater than that of the free amino acids, which indicates that adsorbed amino acids extracted with the strong salt solution likely represent a potential source for the replenishment of free amino acids. We found no appreciable evidence to suggest that amino acids with simple molecular structure were dominant at low elevations, whereas amino acids with high molecular weight and complex aromatic structure dominated the high elevations. Across the elevational gradient, the amino acid pool was dominated by alanine, aspartic acid, glycine, glutamic acid, histidine, serine and threonine. These seven amino acids accounted for approximately 68.9% of the total hydrolyzable amino acid pool. The proportions of isoleucine, tyrosine and methionine varied with elevation, while soil major amino acid composition (including alanine, arginine, aspartic acid, glycine, histidine, leucine, phenylalanine, serine, threonine and valine) did not vary appreciably with elevation (p>0.10). The compositional similarity of many

  16. Elevational Variation in Soil Amino Acid and Inorganic Nitrogen Concentrations in Taibai Mountain, China.

    PubMed

    Cao, Xiaochuang; Ma, Qingxu; Zhong, Chu; Yang, Xin; Zhu, Lianfeng; Zhang, Junhua; Jin, Qianyu; Wu, Lianghuan

    2016-01-01

    Amino acids are important sources of soil organic nitrogen (N), which is essential for plant nutrition, but detailed information about which amino acids predominant and whether amino acid composition varies with elevation is lacking. In this study, we hypothesized that the concentrations of amino acids in soil would increase and their composition would vary along the elevational gradient of Taibai Mountain, as plant-derived organic matter accumulated and N mineralization and microbial immobilization of amino acids slowed with reduced soil temperature. Results showed that the concentrations of soil extractable total N, extractable organic N and amino acids significantly increased with elevation due to the accumulation of soil organic matter and the greater N content. Soil extractable organic N concentration was significantly greater than that of the extractable inorganic N (NO3--N + NH4+-N). On average, soil adsorbed amino acid concentration was approximately 5-fold greater than that of the free amino acids, which indicates that adsorbed amino acids extracted with the strong salt solution likely represent a potential source for the replenishment of free amino acids. We found no appreciable evidence to suggest that amino acids with simple molecular structure were dominant at low elevations, whereas amino acids with high molecular weight and complex aromatic structure dominated the high elevations. Across the elevational gradient, the amino acid pool was dominated by alanine, aspartic acid, glycine, glutamic acid, histidine, serine and threonine. These seven amino acids accounted for approximately 68.9% of the total hydrolyzable amino acid pool. The proportions of isoleucine, tyrosine and methionine varied with elevation, while soil major amino acid composition (including alanine, arginine, aspartic acid, glycine, histidine, leucine, phenylalanine, serine, threonine and valine) did not vary appreciably with elevation (p>0.10). The compositional similarity of many

  17. False elevation of blood glucose levels measured by GDH-PQQ-based glucometers occurs during all daily dwells in peritoneal dialysis patients using icodextrin.

    PubMed

    Tsai, Chiu-Yeh; Lee, Su-Chu; Hung, Chi-Chih; Lee, Jia-Jung; Kuo, Mei-Chuan; Hwang, Shang-Jyh; Chen, Hung-Chun

    2010-01-01

    False elevation of blood glucose levels measured by glucose dehydrogenase pyrroloquinoline quinone (GDH-PQQ)-based glucose self-monitoring systems; glucometer) in peritoneal dialysis (PD) patients using icodextrin solution has been well documented. However, adverse hypoglycemic events caused by misreadings for blood glucose are still being reported. We aimed to study blood glucose levels measured simultaneously using different methods in PD patients with switching of icodextrin, and throughout daily exchanges either using icodextrin or not. We recruited 100 PD patients, including 40 using icodextrin; 128 hemodialysis patients served as a reference. Fasting serum glucose was measured using our laboratory reference method (LAB) and 2 glucose self-monitoring systems based on glucose dehydrogenase nicotinamide adenine dinucleotide (GDH-NAD) and GDH-PQQ respectively. 80 PD patients had a second follow-up study. A time course study was performed in 16 PD patients through measuring fingertip glucose using the 2 glucose self-monitoring systems during daily exchanges. The differences in measured serum glucose levels in (PQQ minus LAB) versus (NAD minus LAB) were markedly increased in PD patients using icodextrin compared to other patient groups, and was further confirmed by the follow-up study in patients that switched to icodextrin. The high serum glucose levels measured by the GDH-PQQ-based glucose self-monitoring system were present throughout all exchanges during the day in patients using icodextrin solution. False elevation of blood glucose measured by GDH-PQQ-based glucose self-monitoring systems exists in patients using icodextrin. To avoid misinterpretation of hyperglycemia and subsequent over-injection of insulin, GDH-PQQ-based glucose self-monitoring systems should not be used in PD patients.

  18. Clofibrate-induced reduction of plasma branched-chain amino acid concentrations impairs glucose tolerance in rats.

    PubMed

    Kadota, Yoshihiro; Kazama, Shunsuke; Bajotto, Gustavo; Kitaura, Yasuyuki; Shimomura, Yoshiharu

    2012-05-01

    It has been reported that branched-chain amino acid (BCAA) administration stimulates glucose uptake into muscles and whole body glucose oxidation in rats. The authors examined the effect of decreased plasma BCAA concentrations induced by clofibrate treatment on glucose tolerance in rats. Since clofibrate, a drug for hyperlipidemia (high serum triglyceride concentration), is a potent inhibitor of the branched-chain α-keto acid dehydrogenase kinase, clofibrate treatment (0.2 g/kg body weight) activated the hepatic branched-chain α-keto acid dehydrogenase complex, resulting in decreased plasma BCAA concentrations by 30% to 50% from the normal level. An intraperitoneal glucose tolerance test was conducted after clofibrate administration, and the results showed that peak plasma glucose concentration and the area under the curve of glucose concentration during the intraperitoneal glucose tolerance test were significantly higher in clofibrate-treated rats than in control rats. This impaired glucose tolerance in the clofibrate-treated rats was ameliorated by administration of BCAAs (0.45 g/kg body weight, leucine:isoleucine:valine = 2:1:1), which kept plasma BCAA concentrations at normal levels during the intraperitoneal glucose tolerance test. These results suggest that plasma BCAAs play an important role in maintaining normal glucose tolerance in rats.

  19. White coat hyperglycaemia: disparity between diabetes clinic and home blood glucose concentrations.

    PubMed

    Campbell, L V; Ashwell, S M; Borkman, M; Chisholm, D J

    1992-11-14

    To identify patients with discrepantly high clinic blood glucose concentrations compared with self reported values and to assess whether such patients have errors in self monitoring technique. To determine whether, in patients with good technique, the discrepancy is a transient phenomenon related to clinic attendance. Prospective study of diabetes clinic patients recruited over six months. Outpatient diabetes clinic of a teaching hospital. 34 consecutive patients with non-insulin dependent diabetes who had had at least two consecutive clinic blood glucose concentrations more than 5 mmol/l higher than the mean self reported concentration. Assessment of monitoring technique; presence of cognitive or physical impairment; serum fructosamine concentration; home and clinic blood glucose concentrations. 15 of 34 patients had errors in monitoring technique, 12 of whom had cognitive or physical impairment. In the remaining 19, the mean (SD) blood glucose concentrations of capillary and venous samples taken at home (10.2 (0.6) and 12.2 (1.1) mmol/l respectively) were significantly lower than in those taken at the clinic (16.8 (1.6) mmol/l, p < 0.0002). The fructosamine concentration was significantly higher in patients with monitoring errors than those without (2.4 (0.4) v 1.8 (0.4) mmol/l, p < 0.0001). "White coat" hyperglycaemia was detected in about half the patients but errors in technique accounted for the rest of the discrepancies. Patients' ability should be assessed before teaching self monitoring and the technique checked regularly.

  20. Exploration and Practice in Photoacoustic Measurement for Glucose Concentration Based on Tunable Pulsed Laser Induced Ultrasound

    NASA Astrophysics Data System (ADS)

    Ren, Zhong; Liu, Guodong; Huang, Zhen; Zhao, Dengji; Xiong, Zhihua

    2015-07-01

    In this article, a tunable pulsed laser induced photoacoustic measurement setup of monitoring glucose concentration was established in the forward mode. In experiments, the time-resolved photoacoustic signal of glucose aqueous solution with different concentrations of 0-300 mg/dl were captured and averaged 512 times, and the photoacoustic peak-to-peak values were recorded using the wavelength scan in NIR region of 1300-2300 nm. The optimal characteristic wavelengths of glucose were determined via the difference spectral and the first derivative spectral algorithm, and correction models between peak-to-peak values of optimal wavelengths and concentration gradients were established using multivariate linear regression algorithm. Experimental results demonstrated that the profile and logarithm shape of time-resolved photoacoustic signal for glucose solutions were in good agreement with photoacoustic theories. The prediction effect of optimal wavelength of 1510 nm was best, its root-mean-square errors of correction and prediction were 12.14 and 8.45 mg/dl, respectively, the correlation coefficient reached 0.9856.

  1. Real-time estimation of glucose concentration in algae cultivation system using Raman spectroscopy.

    PubMed

    Oh, Se-Kyu; Yoo, Sung Jin; Jeong, Dong Hwi; Lee, Jong Min

    2013-08-01

    This work proposes a soft-sensor design for real-time estimation of glucose concentration under mixotrophic conditions using Raman spectroscopy. The suggested approach applies a Rolling-Circle Filter (RCF), Partial Least Squares (PLS), and a successive Savitzky-Golay (SG) smoothing filter. RCF is used to remove the background effects of Raman spectrum in the pre-processing step. PLS is used to reduce the dimensionality of spectrum data and relate them to the concentration. The SG filter is further employed as a post-processing step in a successive manner to adjust predicted glucose concentrations. Two sets of experiments using artificial assays and samples from a microalgae cultivation system were performed for verification. The proposed approach showed improved prediction performances compared to other data processing and regression techniques.

  2. Glucose concentration measured by the hybrid coherent anti-Stokes Raman-scattering technique

    NASA Astrophysics Data System (ADS)

    Wang, Xi; Zhang, Aihua; Zhi, Miaochan; Sokolov, Alexei V.; Welch, George R.

    2010-01-01

    We investigate the possibility of using a hybrid coherent anti-Stokes Raman scattering technique for noninvasive monitoring of blood glucose levels. Our technique combines instantaneous coherent excitation of several characteristic molecular vibrations with subsequent probing of these vibrations by an optimally shaped, time-delayed, narrowband laser pulse. This pulse configuration mitigates the nonresonant four-wave mixing background while maximizing the Raman-resonant signal and allows rapid and highly specific detection even in the presence of multiple scattering. Under certain conditions we find that the measured signal is linearly proportional to the glucose concentration due to optical interference with the residual background light, which allows reliable detection of spectral signatures down to medically relevant glucose levels.

  3. Assessment of circulating betatrophin concentrations in lean glucose-tolerant women with polycystic ovary syndrome.

    PubMed

    Erol, Onur; Özel, Mustafa Kemal; Ellidağ, Hamit Yaşar; Toptaş, Tayfun; Derbent, Aysel Uysal; Yılmaz, Necat

    2017-03-20

    authors included overweight/obese patients and glucose tolerance was not evaluated before recruitment. What the results of this study add: Our results showed that serum betatrophin levels were significantly higher in lean glucose-tolerant PCOS women than in age- and BMI-matched healthy controls. What are the implications of these findings for clinical practice and/or further research: Elevated betatrophin levels in PCOS women, in the absence of obesity and glucose intolerance, may reflect a compensatory mechanism in order to counteract metabolic syndrome-related risk factors.

  4. Carboxyhemoglobin concentrations in flash fire victims: report of six simultaneous fire fatalities without elevated carboxyhemoglobin.

    PubMed

    Hirsch, C S; Bost, R O; Gerber, S R; Cowan, M E; Adelson, L; Sunshine, I

    1977-09-01

    Eight people died in a traffic accident involving a tractor-trailer and ten autos. The accident caused a series of flash fires from ruptured gas tanks. Complete autopsies established that six of the victims died exclusively from thermal trauma; none showed an elevated blood carboxyhemoglobin concentration. Flash fire victims are exceptions to the axiom that elevation of blood carboxyhemoglobin is a sine qua non for concluding that a decedent recovered from the scene of a conflagration was alive in the fire.

  5. Differential Responses of Plasma Adropin Concentrations To Dietary Glucose or Fructose Consumption In Humans

    PubMed Central

    Butler, Andrew A.; St-Onge, Marie-Pierre; Siebert, Emily A.; Medici, Valentina; Stanhope, Kimber L.; Havel, Peter J.

    2015-01-01

    Adropin is a peptide hormone encoded by the Energy Homeostasis Associated (ENHO) gene whose physiological role in humans remains incompletely defined. Here we investigated the impact of dietary interventions that affect systemic glucose and lipid metabolism on plasma adropin concentrations in humans. Consumption of glucose or fructose as 25% of daily energy requirements (E) differentially affected plasma adropin concentrations (P < 0.005) irrespective of duration, sex or age. Glucose consumption reduced plasma adropin from 3.55 ± 0.26 to 3.28 ± 0.23 ng/ml (N = 42). Fructose consumption increased plasma adropin from 3.63 ± 0.29 to 3.93 ± 0.34 ng/ml (N = 45). Consumption of high fructose corn syrup (HFCS) as 25% E had no effect (3.43 ± 0.32 versus 3.39 ± 0.24 ng/ml, N = 26). Overall, the effect of glucose, HFCS and fructose on circulating adropin concentrations were similar to those observed on postprandial plasma triglyceride concentrations. Furthermore, increases in plasma adropin levels with fructose intake were most robust in individuals exhibiting hypertriglyceridemia. Individuals with low plasma adropin concentrations also exhibited rapid increases in plasma levels following consumption of breakfasts supplemented with lipids. These are the first results linking plasma adropin levels with dietary sugar intake in humans, with the impact of fructose consumption linked to systemic triglyceride metabolism. In addition, dietary fat intake may also increase circulating adropin concentrations. PMID:26435060

  6. The fluctuation of blood glucose, insulin and glucagon concentrations before and after insulin therapy in type 1 diabetes

    NASA Astrophysics Data System (ADS)

    Arif, Idam; Nasir, Zulfa

    2015-09-01

    A dynamical-systems model of plasma glucose, insulin and glucagon concentrations has been developed to investigate the effects of insulin therapy on blood glucose, insulin and glucagon regulations in type 1 diabetic patients. Simulation results show that the normal regulation of blood glucose concentration depends on insulin and glucagon concentrations. On type 1 diabetic case, the role of insulin on regulating blood glucose is not optimal because of the destruction of β cells in pancreas. These β cells destructions cause hyperglycemic episode affecting the whole body metabolism. To get over this, type 1 diabetic patients need insulin therapy to control the blood glucose level. This research has been done by using rapid acting insulin (lispro), long-acting insulin (glargine) and the combination between them to know the effects of insulin therapy on blood glucose, insulin and glucagon concentrations. Simulation results show that these different types of insulin have different effects on blood glucose concentration. Insulin therapy using lispro shows better blood glucose control after consumption of meals. Glargin gives better blood glucose control between meals and during sleep. Combination between lispro and glargine shows better glycemic control for whole day blood glucose level.

  7. Prevalence of Elevated Glycated Hemoglobin Concentrations in the Polycystic Ovary Syndrome: Anthropometrical and Metabolic Relationship in Amazonian Women

    PubMed Central

    de Medeiros, Sebastiao Freitas; Yamamoto, Marcia Marly Winck; Bueno, Herica Bernardes; Belizario, Danilla; Barbosa, Jacklyne Silva

    2014-01-01

    Background To determine the prevalence of elevated glycated hemoglobin (HbA1c) and to examine its relationship with other carbohydrate metabolic parameter among Brazilian women with polycystic ovary syndrome (PCOS). Methods A cross-sectional study including 288 PCOS patients was conducted. Anthropometrical, clinical, biochemical and endocrine parameters were evaluated. Results The mean age was 26.92 ± 5.51 years. HbA1c mean concentration was 5.83±1.34%. In 38.54% of patients, HbA1c was ≥ 5.7%. HbA1c was positively correlated with body weight (r = 0.142, P = 0.017), body mass index (P = 0.000), waist:hip ratio (P = 0.000), fat mass (P = 0.000), conicity index (P = 0.000), triglyceride (P = 0.001), C-peptide (P = 0.000), total testosterone (P = 0.003), free testosterone (P = 0.000), free androgen index (P = 0.006) and fasting insulin (P = 0.025). Using the oral glucose tolerance test, HbA1c showed positive correlation with glucose concentrations at any point in time (P < 0.05). Conclusions HbA1c was elevated in nearly 40% of PCOS patients and it showed positive correlation with several anthropometric and metabolic factors and androgen levels. The current study provides further evidence that HbA1C is higher in PCOS patients and may have a potential role in the prediction of dysglycemic disease in these women. PMID:24883154

  8. Plasma cortisol and glucose concentrations in the striped mullet ( Mugil cephalus L.) subjected to intense handling stress

    NASA Astrophysics Data System (ADS)

    Hong, Wanshu

    1992-03-01

    The plasma cortisol and glucose concentrations were determined in mature female striped mullet ( Mugil cephalus L.) subjected to short term intense handling stress. The results indicated that plasma cortisol levels reached a peak 20 min after stress and declined gradually afterwards. The highest concentration of plasma glucose was observed 30 min after stress. The present study showed that the rise of plasma glucose was associated with the plasma cortisol levels.

  9. Seasonal variations in plasma glucose and insulin concentrations after glucose loading in the edible dormouse (Glis glis L.).

    PubMed

    Castex, C; Donnio, R; Sutter, B C

    1979-01-01

    Glucose tolerance tests made in the Edible dormouse showed annual variations in B cell secretory capacity, associated with glucose tolerance changes. 1. During autumn and winter, the B cell is sensitive to glucose, and insulin regulates the high peripheral consumption of this hexose. 2. At the beginning of spring, insulin secretion decreases and glucose tolerance is impaired. In June, the B cell response si low or absent and a poor tolerance to glucose still persists. 3. The variations in B cell activity can be related to changing energy requirements during the year.

  10. [Effects of elevated atmospheric CO2 concentration on mung bean leaf photosynthesis and chlorophyll fluorescence parameters].

    PubMed

    Hao, Xing-yu; Han, Xue; Li, Ping; Yang, Hong-bin; Lin, Er-da

    2011-10-01

    By using free air CO2 enrichment (FACE) system, a pot experiment under field condition was conducted to study the effects of elevated CO2 concentration (550 +/- 60 micromol mol(-1)) on the leaf photosynthesis and chlorophyll fluorescence parameters of mung bean. Comparing with the control (CO2 concentration averagely 389 +/- 40 micromol mol(-1)), elevated CO2 concentration increased the leaf intercellular CO2 concentration (Ci) and net photosynthesis rate (P(n)) at flowering and pod growth stage by 9.8% and 11.7%, decreased the stomatic conductance (G(s)) and transpiration rate (T(r)) by 32.0% and 24.6%, respectively, and increased the water use efficiency (WUE) by 83.5%. Elevated CO2 concentration had lesser effects on the minimal fluorescence (F0), maximal fluorescence (F(m)), variable fluorescence (F(v)), ratio of variable fluorescence to minimal fluorescence (F(v)/F0), and ratio of variable fluorescence to maximal fluorescence (F(v)/F(m)) at bud stage, but increased the F0 at pod filling stage by 19.1% and decreased the Fm, F(v), F(v)/F0, and F(v)/F(m) by 9.0%, 14.3%, 25.8% , and 6.2%, respectively. These results suggested that elevated CO2 concentration could damage the structure of leaf photosystem II and consequently decrease the leaf photosynthetic capacity in the late growth phase of mung bean.

  11. The Influence of Variation in Time and HCl Concentration to the Glucose Produced from Kepok Banana

    NASA Astrophysics Data System (ADS)

    Widodo M, Rohman; Noviyanto, Denny; RM, Faisal

    2016-01-01

    Kepok banana (Musa paradisiaca) is a plant that has many advantagesfrom its fruit, stems, leaves, flowers and cob. However, we just tend to take benefit from the fruit. We grow and harvest the fruit without taking advantages from other parts. So they would be a waste or detrimental to animal nest if not used. The idea to take the benefit from the banana crop yields, especially cob is rarely explored. This study is an introduction to the use of banana weevil especially from the glucose it contains. This study uses current methods of hydrolysis using HCl as a catalyst with the concentration variation of 0.4 N, 0.6 N and 0.8 N and hydrolysis times variation of 20 minutes, 25 minutes and 30 minutes. The stages in the hydrolysis include preparation of materials, the process of hydrolysis and analysis of test results using Fehling and titrate with standard glucose solution. HCl is used as a catalyst because it is cheaper than the enzyme that has the same function. NaOH 60% is used for neutralizing the pH of the filtrate result of hydrolysis. From the results of analysis, known thatthe biggest yield of glucose is at concentration 0.8 N and at 30 minutes reaction, it contains 6.25 gram glucose / 20 gram dry sampel, and the convertion is 27.22% at 20 gram dry sampel.

  12. Elevated atmospheric CO2 concentration enhances salinity tolerance in Aster tripolium L.

    PubMed

    Geissler, Nicole; Hussin, Sayed; Koyro, Hans-Werner

    2010-02-01

    Our study aimed at investigating the influence of elevated atmospheric CO(2) concentration on the salinity tolerance of the cash crop halophyte Aster tripolium L., thereby focussing on protein expression and enzyme activities. The plants were grown in hydroponics using a nutrient solution with or without addition of NaCl (75% seawater salinity), under ambient (380 ppm) and elevated (520 ppm) CO(2). Under ambient CO(2) concentration enhanced expressions and activities of the antioxidant enzymes superoxide dismutase, ascorbate peroxidase, and glutathione-S-transferase in the salt-treatments were recorded as a reaction to oxidative stress. Elevated CO(2) led to significantly higher enzyme expressions and activities in the salt-treatments, so that reactive oxygen species could be detoxified more effectively. Furthermore, the expression of a protective heat shock protein (class 20) increased under salinity and was even further enhanced under elevated CO(2) concentration. Additional energy had to be provided for the mechanisms mentioned above, which was indicated by the increased expression of a beta ATPase subunit and higher v-, p- and f-ATPase activities under salinity. The higher ATPase expression and activities also enable a more efficient ion transport and compartmentation for the maintenance of ion homeostasis. We conclude that elevated CO(2) concentration is able to improve the survival of A. tripolium under salinity because more energy is provided for the synthesis and enhanced activity of enzymes and proteins which enable a more efficient ROS detoxification and ion compartmentation/transport.

  13. Growth, biofilm formation, antifungal susceptibility and oxidative stress resistance of Candida glabrata are affected by different glucose concentrations.

    PubMed

    Ng, Tzu Shan; Desa, Mohd Nasir Mohd; Sandai, Doblin; Chong, Pei Pei; Than, Leslie Thian Lung

    2016-06-01

    Glucose is an important fuel source to support many living organisms. Its importance in the physiological fitness and pathogenicity of Candida glabrata, an emerging human fungal pathogen has not been extensively studied. The present study aimed to investigate the effects of glucose on the growth, biofilm formation, antifungal susceptibility and oxidative stress resistance of C. glabrata. In addition, its effect on the expression of a putative high affinity glucose sensor gene, SNF3 was also investigated. Glucose concentrations were found to exert effects on the physiological responses of C. glabrata. The growth rate of the species correlated positively to the amount of glucose. In addition, low glucose environments were found to induce C. glabrata to form biofilm and resist amphotericin B. Conversely, high glucose environments promoted oxidative stress resistance of C. glabrata. The expression of CgSNF3 was found to be significantly up-regulated in low glucose environments. The expression of SNF3 gene in clinical isolates was found to be higher compared to ATCC laboratory strains in low glucose concentrations, which may explain the better survivability of clinical isolates in the low glucose environment. These observations demonstrated the impact of glucose in directing the physiology and virulence fitness of C. glabrata through the possible modulation by SNF3 as a glucose sensor, which in turn aids the species to adapt, survive and thrive in hostile host environment. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Blood concentrations of amino acids, glucose and lactate during experimental swine dysentery.

    PubMed

    Jonasson, R; Essén-Gustavsson, B; Jensen-Waern, M

    2007-06-01

    The aim of this study was to examine blood concentrations of amino acids, glucose and lactate in association with experimental swine dysentery. Ten pigs (approximately 23kg) were orally inoculated with Brachyspira hyodysenteriae. Eight animals developed muco-haemorrhagic diarrhoea with impaired general appearance, changes in white blood cell counts and increased levels of the acute phase protein Serum Amyolid A. Blood samples were taken before inoculation, during the incubation period, during clinical signs of dysentery and during recovery. Neither plasma glucose nor lactate concentrations changed during the course of swine dysentery, but the serum concentrations of gluconeogenic non-essential amino acids decreased during dysentery. This was mainly due to decreases in alanine, glutamine, serine and tyrosine. Lysine increased during dysentery and at the beginning of the recovery period, and leucine increased during recovery. Glutamine, alanine and tyrosine levels show negative correlations with the numbers of neutrophils and monocytes. In conclusion, swine dysentery altered the blood concentrations of amino acids, but not of glucose or lactate.

  15. Effects of glucose concentrations on cadmium, copper, mercury, and zinc toxicity to a Klebsiella sp

    SciTech Connect

    Brynhildsen, L.; Lundgren, B.V.; Allard, B.; Rosswall, T.

    1988-07-01

    The influence of glucose concentration on Cd, CU, Hg, and Zn toxicity to a Klebsiella sp. was studied by following the degradation of /sup 14/C-labeled glucose at pH 6.0. Uptake of /sup 14/C into the cells was also determined. The carbon concentrations ranged from 0.01 to 40 mg liter/sup -1/, which are equivalent to soluble C concentrations in natural environments. The toxicity of Cu, Cd, and Zn to a Klebsiella sp. was affected considerably by the C concentration. Copper at 10/sup -5/ M was toxic when the carbon concentration was 10 or 40 mg liter/sup -1/, while at 0.01 to 1.0 mg liter/sup -1/ no toxicity was observed. Cadmium and zinc were toxic at 10/sup -2/ M in media containing 0.01 to 1.0 mg of C liter/sup -1/. At C concentrations greater than 1.0 mg liter/sup -1/, the inhibition of glucose degradation and carbon assimilation was observed at 10/sup -3/ M Cd and Zn. The toxicity of mercury seemed to be independent of the C concentration. Results of this study showed that the nutritional state of an organism may have a profound effect on its sensitivity to metals. Metals taken up by energy-driven transport system may be less toxic under conditions of C starvation. The C concentration should be taken into account when evaluating results from toxicity studies, especially as most microorganisms in nature live under energy-limited conditions.

  16. Evaluation of the agreement among three handheld blood glucose meters and a laboratory blood analyzer for measurement of blood glucose concentration in Hispaniolan Amazon parrots (Amazona ventralis).

    PubMed

    Acierno, Mark J; Mitchell, Mark A; Schuster, Patricia J; Freeman, Diana; Sanchez-Migallon Guzman, David; Tully, Thomas N

    2009-02-01

    To determine the degree of agreement between 3 commercially available point-of-care blood glucose meters and a laboratory analyzer for measurement of blood glucose concentrations in Hispaniolan Amazon parrots (Amazona ventralis). 20 healthy adult Hispaniolan Amazon parrots. A 26-gauge needle and 3-mL syringe were used to obtain a blood sample (approx 0.5 mL) from a jugular vein of each parrot. Small volumes of blood (0.6 to 1.5 microL) were used to operate each of the blood glucose meters, and the remainder was placed into lithium heparin microtubes and centrifuged. Plasma was harvested and frozen at -30 degrees C. Within 5 days after collection, plasma samples were thawed and plasma glucose concentrations were measured by means of the laboratory analyzer. Agreement between pairs of blood glucose meters and between each blood glucose meter and the laboratory analyzer was evaluated by means of the Bland-Altman method, and limits of agreement (LOA) were calculated. None of the results of the 3 blood glucose meters agreed with results of the laboratory analyzer. Each point-of-care blood glucose meter underestimated the blood glucose concentration, and the degree of negative bias was not consistent (meter A bias, -94.9 mg/dL [LOA, -148.0 to -41.7 mg/dL]; meter B bias, -52 mg/dL [LOA, -107.5 to 3.5 mg/dL]; and meter C bias, -78.9 mg/dL [LOA, -137.2 to -20.6 mg/dL]). On the basis of these results, use of handheld blood glucose meters in the diagnosis or treatment of Hispaniolan Amazon parrots and other psittacines cannot be recommended.

  17. Simultaneous detection of pH value and glucose concentrations for wound monitoring applications.

    PubMed

    Jankowska, D A; Bannwarth, M B; Schulenburg, C; Faccio, G; Maniura-Weber, K; Rossi, R M; Scherer, L; Richter, M; Boesel, L F

    2017-01-15

    Aging population and longer life expectancy are the main reasons for an increasing number of patients with wound problems. Although the interest in wound care increases continuously, wound management still remains a challenge mainly due to the higher occurrence of chronic wounds, which require intensive care and constant monitoring. Here, we demonstrate a fluorescent sensing system to monitor the wound status and to distinguish between an autonomously healing and a chronic wound at an early stage. The system allows monitoring two of the most relevant fluctuating wound parameters during the healing process which are pH and glucose concentration. A fluorescent pH indicator dye, carboxynaphthofluorescein, and a metabolite-sensing enzymatic system, based on glucose oxidase and horseradish peroxidase, were immobilized on a biocompatible polysaccharide matrix to develop a functional hydrogel coating for wound monitoring. The changes in metabolite and enzyme concentration in artificial wound extract were converted into a fluorescent signal.

  18. Improved noncontact optical sensor for detection of glucose concentration and indication of dehydration level

    PubMed Central

    Ozana, Nisan; Arbel, Nadav; Beiderman, Yevgeny; Mico, Vicente; Sanz, Martin; Garcia, Javier; Anand, Arun; Javidi, Baharam; Epstein, Yoram; Zalevsky, Zeev

    2014-01-01

    The ability to extract different bio-medical parameters from one single wristwatch device can be very applicable. The wearable device that is presented in this paper is based on two optical approaches. The first is the extraction and separation of remote vibration sources and the second is the rotation of linearly polarized light by certain materials exposed to magnetic fields. The technique is based on tracking of temporal changes of reflected secondary speckles produced in the wrist when being illuminated by a laser beam. Change in skin’s temporal vibration profile together with change in the magnetic medium that is generated by time varied glucose concentration caused these temporal changes. In this paper we present experimental tests which are the first step towards an in vivo noncontact device for detection of glucose concentration in blood. The paper also shows very preliminary results for qualitative capability for indication of dehydration. PMID:24940550

  19. Effects of elevated carbon dioxide concentration on growth and N2 fixation of young Robinia pseudoacacia.

    PubMed

    Feng, Z; Dyckmans, J; Flessa, H

    2004-03-01

    Effects of elevated CO2 concentration ([CO2]) on carbon (C) and nitrogen (N) uptake and N source partitioning (N2 fixation versus mineral soil N uptake) of 1-year-old Robinia pseudoacacia were determined in a dual 13C and 15N continuous labeling experiment. Seedlings were grown for 16 weeks in ambient (350 ppm) or elevated [CO2] (700 ppm) with 15NH4 15NO3 as the only mineral nitrogen source. Elevated [CO2] increased the fraction of new C in total C, but it did not alter C partitioning among plant compartments. Elevated [CO2] also increased the fraction of new N in total N and this was coupled with a shift in N source partitioning toward N2 fixation. Soil N uptake was unaffected by elevated [CO2], whereas N2 fixation was markedly increased by the elevated [CO2] treatment, mainly because of increased specific fixation (mg N mg(-1) nodule). As a result of increased N2 fixation, the C/N ratio of tree biomass tended to decrease in the elevated [CO2] treatment. Partitioning of N uptake among plant compartments was unaffected by elevated [CO2]. Total dry mass of root nodules doubled in response to elevated [CO2], but this effect was not significant because of the great variability of root nodule formation. Our results show that, in the N2-fixing R. pseudoacacia, increased C uptake in response to increased [CO2] is matched by increased N2 fixation, indicating that enhanced growth in elevated [CO2] might not be restricted by N limitations.

  20. Elevated skeletal muscle glucose transporter levels in exercise-trained middle-aged men.

    PubMed

    Houmard, J A; Egan, P C; Neufer, P D; Friedman, J E; Wheeler, W S; Israel, R G; Dohm, G L

    1991-10-01

    Exercise training has been proposed to improve whole body insulin sensitivity through a postreceptor adaptation in skeletal muscle. This study examined if levels of the insulin-responsive muscle glucose transporter protein (GLUT-4) were associated with improved insulin sensitivity in trained vs. sedentary middle-aged individuals. Muscle GLUT-4 levels and oral glucose tolerance test (OGTT) responses were obtained in age-matched trained and sedentary men (n = 11). Plasma insulin levels during the OGTT were significantly lower (P less than 0.01) in the trained men, whereas no differences were seen in plasma glucose responses. GLUT-4 protein content was approximately twofold higher in the trained men (2.41 +/- 0.17 vs. 1.36 +/- 0.11 micrograms standard, P less than 0.001). OGTT responses and GLUT-4 levels were not altered 15-18 h after a standard exercise bout in six representative sedentary subjects. These data suggest that GLUT-4 levels are increased in conjunction with insulin sensitivity in chronically exercise-trained middle-aged men. This finding suggests a possible mechanism for the improved insulin sensitivity observed with exercise training in humans.

  1. Carbohydrate concentrations and freezing stress resistance of silver birch buds grown under elevated temperature and ozone.

    PubMed

    Riikonen, Johanna; Kontunen-Soppela, Sari; Vapaavuori, Elina; Tervahauta, Arja; Tuomainen, Marjo; Oksanen, Elina

    2013-03-01

    The effects of slightly elevated temperature (+0.8 °C), ozone (O3) concentration (1.3 × ambient O3 concentration) and their combination on over-wintering buds of Betula pendula Roth were studied after two growing seasons of exposure in the field. Carbohydrate concentrations, freezing stress resistance (FSR), bud dry weight to fresh weight ratio, and transcript levels of cytochrome oxidase (COX), alternative oxidase (AOX) and dehydrin (LTI36) genes were studied in two clones (clones 12 and 25) in December. Elevated temperature increased the bud dry weight to fresh weight ratio and the ratio of raffinose family oligosaccharides to sucrose and the transcript levels of the dehydrin (LTI36) gene (in clone 12 only), but did not alter the FSR of the buds. Genotype-specific alterations in carbohydrate metabolism were found in the buds grown under elevated O3. The treatments did not significantly affect the transcript level of the COX or AOX genes. No clear pattern of an interactive effect between elevated temperature and O3 concentration was found. According to these data, the increase in autumnal temperatures and slightly increasing O3 concentrations do not increase the risk for freeze-induced damage in winter in silver birch buds, although some alterations in bud physiology occur.

  2. Naturally Elevated Monomethylmercury and Mercury Concentrations of Redwood Trees of Coastal California

    NASA Astrophysics Data System (ADS)

    Rytuba, J. J.

    2014-12-01

    Redwood trees (Sequoia sempervirens) of coastal California acquire up to a third of their annual water through direct foliar uptake from summer coastal fog. Coastal fog contains elevated concentrations of monomethylmercury (MMeHg) up to 9.8 ng/L (Weiss-Penzias et al., Geophys Res Letters, 39). MMeHg introduced by fog is concentrated in old growth redwood trees throughout their distribution along the California coast. High concentrations of MMeHg occur in living redwood needles (0.20 to 3.76 ng/g dry weight basis, dwb) and are about 2 orders of magnitude greater than typical in evergreen needles that do not receive coastal fog water. MMeHg concentration in living redwood needles changes seasonally reaching a maximum at the end of the fog season (October) and a minimum at the beginning of the fog season (March). Hg concentrations in living redwood needles range from 21.7 to 80.5 ng/g (dwb), comparable to reported values for evergreen needles from non-coastal trees. Redwoods planted in the suburban landscape inland from the coastal fog belt have considerably lower MMeHg concentrations (<0.20 ng/g) but similar Hg concentrations to redwoods in their natural coastal environment. Redwood needles die after 3 years and contain comparable concentrations of MMeHg to those in living needles from the same old growth redwoods but Hg concentrations are much higher (up to 142 ng/g) since Hg accumulates throughout the life of the needle. Stream waters in old growth redwood forests under low and high flow conditions have very low concentrations of MMeHg (<.02 ng/L). However, under high flow conditions Hg concentrations are elevated, up to 22 ng/L, compared to low flow conditions (1.3-3.15 ng/L) and in rainwater (5.4 ng/L). MMeHg concentrations in stream waters are not elevated because MMeHg is retained in redwood needles. Hg concentrations in high flow stream waters are elevated because soils developed under old growth redwoods have elevated concentrations of Hg, up to 280 ng/g (3

  3. Effect of elevated CO2 concentration on photosynthetic characteristics of hyperaccumulator Sedum alfredii under cadmium stress.

    PubMed

    Li, Tingqiang; Tao, Qi; Di, Zhenzhen; Lu, Fan; Yang, Xiaoe

    2015-07-01

    The combined effects of elevated CO2 and cadmium (Cd) on photosynthetic rate, chlorophyll fluorescence and Cd accumulation in hyperaccumulator Sedum alfredii Hance were investigated to predict plant growth under Cd stress with rising atmospheric CO2 concentration. Both pot and hydroponic experiments were conducted and the plants were grown under ambient (350 µL L(-1)) or elevated (800 µL L(-1)) CO2 . Elevated CO2 significantly (P < 0.05) increased Pn (105%-149%), Pnmax (38.8%-63.0%) and AQY (20.0%-34.8%) of S. alfredii in all the Cd treatments, but reduced chlorophyll concentration, dark respiration and photorespiration. After 10 days growth in medium with 50 µM Cd under elevated CO2 , PSII activities were significantly enhanced (P < 0.05) with Pm, Fv/Fm, Φ(II) and qP increased by 66.1%, 7.5%, 19.5% and 16.4%, respectively, as compared with ambient-grown plants. Total Cd uptake in shoot of S. alfredii grown under elevated CO2 was increased by 44.1%-48.5%, which was positively correlated with the increase in Pn. These results indicate that elevated CO2 promoted the growth of S. alfredii due to increased photosynthetic carbon uptake rate and photosynthetic light-use efficiency, and showed great potential to improve the phytoextraction of Cd by S. alfredii. © 2014 Institute of Botany, Chinese Academy of Sciences.

  4. Effect of glucose concentration on the rate of fructose consumption in native strains isolated from the fermentation of Agave duranguensis.

    PubMed

    Díaz-Campillo, M; Urtíz, N; Soto, O; Barrio, E; Rutiaga, M; Páez, J

    2012-12-01

    Studies on hexose consumption by Saccharomyces cerevisiae show that glucose is consumed faster than fructose when both are present (9:1 fructose to glucose) in the medium during the fermentation of Agave. The objective of this work was to select strains of S. cerevisiae that consume fructose equal to or faster than glucose at high fructose concentrations by analyzing the influence of different glucose concentrations on the fructose consumption rate. The optimal growth conditions were determined by a kinetics assay using high performance liquid chromatography (HPLC) using 50 g of glucose and 50 g of fructose per liter of synthetic medium containing peptone and yeast extract. Using the same substrate concentrations, strain ITD-00185 was shown to have a higher reaction rate for fructose over glucose. At 75 g of fructose and 25 g of glucose per liter, strain ITD-00185 had a productivity of 1.02 gL(-1) h(-1) after 40 h and a fructose rate constant of 0.071 h(-1). It was observed that glucose concentration positively influences fructose consumption when present in a 3:1 ratio of fructose to glucose. Therefore, adapted strains at high fructose concentrations could be used as an alternative to traditional fermentation processes.

  5. Effect of glucose concentration on formation of AGEs in erythrocytes in vitro.

    PubMed

    Nagai, Ryoji; Deemer, Elizabeth K; Brock, Jonathan W; Thorpe, Suzanne R; Baynes, John W

    2005-06-01

    Posttranslational modifications, such as advanced glycoxidation and lipoxidation end products (AGE/ALEs), are implicated in the pathogenesis of diabetic complications and atherosclerosis. Recent studies have demonstrated that AGE/ALEs are generated not only in extracellular matrix proteins, but also in intracellular proteins from metabolic intermediates. In this study we investigate the effect of glucose concentration on the formation of the AGE/ALEs, Nepsilon-(carboxymethyl)lysine (CML), Nepsilon-(carboxyethyl)lysine (CEL), S-(carboxymethyl)cysteine (CMC), and S-(2-succinyl)cysteine (2SC) in erythrocytes as a function of glucose concentration. Human erythrocytes (10% hematocrit) were incubated in Dulbecco's modified Eagle's medium (DMEM) containing 5 mM or 30 mM glucose for 5 days at 37 degrees C. Globin was recovered by precipitation with 0.25 M HCl in acetone. Following acid hydrolysis, amino acids were converted to their trifluoroacetyl methyl ester derivatives and analyzed by GC/MS/MS. The CML and CEL content of globin increased in a time- and glucose-dependent manner and also increased 1.3- and 1.8-fold, respectively, in incubations containing 30 mM glucose; whereas CMC and 2SC content did not change during the five-day incubations. Furthermore, CEL content of globin in erythrocytes incubated with 30 mM was the highest in the other AGEs, indicating that methylglyoxal may play a major role in AGE formation in erythrocytes. The erythrocyte system should be useful for cellular screening of the efficacy of inhibitors of AGE/ALE formation.

  6. Kinetics of Bacillus thuringiensis var. israelensis growth on high glucose concentrations.

    PubMed

    Berbert-Molina, M A; Prata, A M R; Pessanha, L G; Silveira, M M

    2008-11-01

    The kinetic and general growth features of Bacillus thuringiensis var. israelensis were evaluated. Initial glucose concentration (S0) in fermentation media varied from 10 to 152 g/l. The results afforded to characterize four morphologically and physiologically well-defined culture phases, independent of S0 values: Phase I, vegetative growth; Phase II, transition to sporulation; Phase III, sporulation; and Phase IV, spores maturation and cell lysis. Important process parameters were also determined. The maximum specific growth rates (microX,m) were not affected with S0 up to 75 g/l (1.0-1.1 per hour), but higher glucose concentrations resulted in growth inhibition by substrate, revealed by a reduction in microX,m values. These higher S0 values led to longer Phases III and IV and delayed sporulation. Similar biomass concentrations (Xm=15.2-15.9 g/l) were achieved with S0 over 30.8 g/l, with increasing residual substrate, suggesting a limitation in some other nutrients and the use of glucose to form other metabolites. In this case, with S0 from 30.8 to 152 g/l, cell yield (YX/S) decreased from 0.58 to 0.41 g/g. On the other hand, with S0=10 g/l growth was limited by substrate, and YX/S has shown its maximum value (0.83 g/g).

  7. Carbon fluxes acclimate more strongly to elevated growth temperatures than to elevated CO2 concentrations in a northern conifer.

    PubMed

    Kroner, Yulia; Way, Danielle A

    2016-08-01

    Increasing temperatures and atmospheric CO2 concentrations will affect tree carbon fluxes, generating potential feedbacks between forests and the global climate system. We studied how elevated temperatures and CO2 impacted leaf carbon dynamics in Norway spruce (Picea abies), a dominant northern forest species, to improve predictions of future photosynthetic and respiratory fluxes from high-latitude conifers. Seedlings were grown under ambient (AC, c. 435 μmol mol(-1) ) or elevated (EC, 750 μmol mol(-1) ) CO2 concentrations at ambient, +4 °C, or +8 °C growing temperatures. Photosynthetic rates (Asat ) were high in +4 °C/EC seedlings and lowest in +8 °C spruce, implying that moderate, but not extreme, climate change may stimulate carbon uptake. Asat , dark respiration (Rdark ), and light respiration (Rlight ) rates acclimated to temperature, but not CO2 : the thermal optimum of Asat increased, and Rdark and Rlight were suppressed under warming. In all treatments, the Q10 of Rlight (the relative increase in respiration for a 10 °C increase in leaf temperature) was 35% higher than the Q10 of Rdark , so the ratio of Rlight to Rdark increased with rising leaf temperature. However, across all treatments and a range of 10-40 °C leaf temperatures, a consistent relationship between Rlight and Rdark was found, which could be used to model Rlight in future climates. Acclimation reduced daily modeled respiratory losses from warm-grown seedlings by 22-56%. When Rlight was modeled as a constant fraction of Rdark , modeled daily respiratory losses were 11-65% greater than when using measured values of Rlight . Our findings highlight the impact of acclimation to future climates on predictions of carbon uptake and losses in northern trees, in particular the need to model daytime respiratory losses from direct measurements of Rlight or appropriate relationships with Rdark . © 2016 John Wiley & Sons Ltd.

  8. Intermittent Elevated Radium Concentrations in Coastal Plain Groundwater of South Carolina, U.S.A.

    SciTech Connect

    Denham, Miles; Millings, Margaret; Noonkester, Jay

    2005-09-22

    To learn the cause of intermittent radium concentrations in groundwater of Coastal Plain aquifers, 31 groundwater wells in South Carolina, U.S.A. were sampled for radium and other geochemical parameters. Sediments cored from near the well screens were also sampled to examine any relationship between sediment properties and radium concentration in the groundwater. Elevated radium concentrations only occurred in groundwater with low electrical conductivity and pH values below 6.3. The adsorption edge for radium on hematite--a major surface active mineral in these aquifers--is at a pH value of about 6. Near this value, small changes in pH can result in significant adsorption or desorption of radium. In groundwater with initially low alkalinity, small intermittent decreases in partial pressure of carbon dioxide in groundwater cause decreases in pH and desorption of radium. The result is intermittent elevated radium concentrations.

  9. Modest decrements in plasma glucose concentration cause early impairment in cognitive function and later activation of glucose counterregulation in the absence of hypoglycemic symptoms in normal man.

    PubMed Central

    De Feo, P; Gallai, V; Mazzotta, G; Crispino, G; Torlone, E; Perriello, G; Ventura, M M; Santeusanio, F; Brunetti, P; Bolli, G B

    1988-01-01

    To establish the glycemic threshold for onset of neuroglycopenia (impaired cognitive function, measured by the latency of the P300 wave), activation of hormonal counterregulation and hypoglycemic symptoms, 12 normal subjects were studied either under conditions of insulin-induced, glucose-controlled plasma glucose decrements, or during maintenance of euglycemia. A decrement in plasma glucose concentration from 88 +/- 3 to 80 +/- 1 mg/dl for 150 min did not result in changes in the latency of the P300 wave nor in an activation of counterregulatory hormonal response. In contrast, a greater decrement in plasma glucose concentration from 87 +/- 3 to 72 +/- 1 mg/dl for 120 min caused an increase in the latency of the P300 wave (from 301 +/- 12 to 348 +/- 20 ms, P less than 0.01), a subsequent increase in all counterregulatory hormones but no hypoglycemic symptoms. Finally, when plasma glucose concentration was decreased in a stepwise manner from 88 +/- 2 to 50 +/- 1 mg/dl within 75 min, the increase in the latency of the P300 wave was correlated with the corresponding plasma glucose concentration (r = -0.76, P less than 0.001). The glycemic threshold for hypoglycemic symptoms was 49 +/- 2 mg/dl. Thus, in normal man the glycemic threshold for neuroglycopenia (72 +/- 1 mg/dl) is greater than currently thought; the hormonal counterregulation follows the onset of neuroglycopenia; the hypoglycemic symptoms are a late indicator of advanced neuroglycopenia. PMID:3403713

  10. Effect of chronic hypoglycaemia on glucose concentration and glycogen content in rat brain: a localized 13C NMR study

    PubMed Central

    Lei, Hongxia; Gruetter, Rolf

    2006-01-01

    While chronic hypoglycaemia has been reported to increase unidirectional glucose transport across the blood-brain barrier (BBB) and to increase GLUT1 expression at the endothelium, the effect on steady-state brain d-glucose and brain glycogen content is currently unknown. Brain glucose and glycogen concentrations were directly measured in vivo using localized 13C magnetic resonance spectroscopy (MRS) following 12-14 days of hypoglycaemia. Brain glucose content was significantly increased by 48%, which is consistent with an increase in the maximal glucose transport rate, Tmax, by 58% compared with the sham-treated animals. The localized 13C NMR measurements of brain glucose were directly validated by comparison with biochemically determined brain glucose content after rapid focused microwave fixation (1.4 s at 4 kW). Both in vivo MRS and biochemical measurements implied that brain glycogen content was not affected by chronic hypoglycaemia, consistent with brain glucose being a major factor controlling brain glycogen content. We conclude that the increased glucose transporter expression in chronic hypoglycaemia leads to increased brain glucose content at a given level of glycaemia. Such increased brain glucose concentrations can result in a lowered glycaemic threshold of counter-regulation observed in chronic hypoglycaemia. PMID:16987249

  11. Impact of elevated CO2 concentration under three soil water levels on growth of Cinnamomum camphora.

    PubMed

    Zhao, Xing-zheng; Wang, Gen-xuan; Shen, Zhu-xia; Zhang, Hao; Qiu, Mu-qing

    2006-04-01

    Forest plays very important roles in global system with about 35% land area producing about 70% of total land net production. It is important to consider both elevated CO(2) concentrations and different soil moisture when the possible effects of elevated CO(2) concentration on trees are assessed. In this study, we grew Cinnamomum camphora seedlings under two CO(2) concentrations (350 micromol/mol and 500 micromol/mol) and three soil moisture levels [80%, 60% and 40% FWC (field water capacity)] to focus on the effects of exposure of trees to elevated CO(2) on underground and aboveground plant growth, and its dependence on soil moisture. The results indicated that high CO(2) concentration has no significant effects on shoot height but significantly impacts shoot weight and ratio of shoot weight to height under three soil moisture levels. The response of root growth to CO(2) enrichment is just reversed, there are obvious effects on root length growth, but no effects on root weight growth and ratio of root weight to length. The CO(2) enrichment decreased 20.42%, 32.78%, 20.59% of weight ratio of root to shoot under 40%, 60% and 80% FWC soil water conditions, respectively. And elevated CO(2) concentration significantly increased the water content in aboveground and underground parts. Then we concluded that high CO(2) concentration favours more tree aboveground biomass growth than underground biomass growth under favorable soil water conditions. And CO(2) enrichment enhanced lateral growth of shoot and vertical growth of root. The responses of plants to elevated CO(2) depend on soil water availability, and plants may benefit more from CO(2) enrichment with sufficient water supply.

  12. Impact of elevated CO2 concentration under three soil water levels on growth of Cinnamomum camphora *

    PubMed Central

    Zhao, Xing-Zheng; Wang, Gen-Xuan; Shen, Zhu-Xia; Zhang, Hao; Qiu, Mu-Qing

    2006-01-01

    Forest plays very important roles in global system with about 35% land area producing about 70% of total land net production. It is important to consider both elevated CO2 concentrations and different soil moisture when the possible effects of elevated CO2 concentration on trees are assessed. In this study, we grew Cinnamomum camphora seedlings under two CO2 concentrations (350 μmol/mol and 500 μmol/mol) and three soil moisture levels [80%, 60% and 40% FWC (field water capacity)] to focus on the effects of exposure of trees to elevated CO2 on underground and aboveground plant growth, and its dependence on soil moisture. The results indicated that high CO2 concentration has no significant effects on shoot height but significantly impacts shoot weight and ratio of shoot weight to height under three soil moisture levels. The response of root growth to CO2 enrichment is just reversed, there are obvious effects on root length growth, but no effects on root weight growth and ratio of root weight to length. The CO2 enrichment decreased 20.42%, 32.78%, 20.59% of weight ratio of root to shoot under 40%, 60% and 80% FWC soil water conditions, respectively. And elevated CO2 concentration significantly increased the water content in aboveground and underground parts. Then we concluded that high CO2 concentration favours more tree aboveground biomass growth than underground biomass growth under favorable soil water conditions. And CO2 enrichment enhanced lateral growth of shoot and vertical growth of root. The responses of plants to elevated CO2 depend on soil water availability, and plants may benefit more from CO2 enrichment with sufficient water supply. PMID:16532530

  13. Prochlorococcus can use the Pro1404 transporter to take up glucose at nanomolar concentrations in the Atlantic Ocean

    PubMed Central

    Muñoz-Marín, María del Carmen; Luque, Ignacio; Zubkov, Mikhail V.; Hill, Polly G.; Diez, Jesús; García-Fernández, José Manuel

    2013-01-01

    Prochlorococcus is responsible for a significant part of CO2 fixation in the ocean. Although it was long considered an autotrophic cyanobacterium, the uptake of organic compounds has been reported, assuming they were sources of limited biogenic elements. We have shown in laboratory experiments that Prochlorococcus can take up glucose. However, the mechanisms of glucose uptake and its occurrence in the ocean have not been shown. Here, we report that the gene Pro1404 confers capability for glucose uptake in Prochlorococcus marinus SS120. We used a cyanobacterium unable to take up glucose to engineer strains that express the Pro1404 gene. These recombinant strains were capable of specific glucose uptake over a wide range of glucose concentrations, showing multiphasic transport kinetics. The Ks constant of the high affinity phase was in the nanomolar range, consistent with the average concentration of glucose in the ocean. Furthermore, we were able to observe glucose uptake by Prochlorococcus in the central Atlantic Ocean, where glucose concentrations were 0.5–2.7 nM. Our results suggest that Prochlorococcus are primary producers capable of tuning their metabolism to energetically benefit from environmental conditions, taking up not only organic compounds with key limiting elements in the ocean, but also molecules devoid of such elements, like glucose. PMID:23569224

  14. Prochlorococcus can use the Pro1404 transporter to take up glucose at nanomolar concentrations in the Atlantic Ocean.

    PubMed

    Muñoz-Marín, María del Carmen; Luque, Ignacio; Zubkov, Mikhail V; Hill, Polly G; Diez, Jesús; García-Fernández, José Manuel

    2013-05-21

    Prochlorococcus is responsible for a significant part of CO2 fixation in the ocean. Although it was long considered an autotrophic cyanobacterium, the uptake of organic compounds has been reported, assuming they were sources of limited biogenic elements. We have shown in laboratory experiments that Prochlorococcus can take up glucose. However, the mechanisms of glucose uptake and its occurrence in the ocean have not been shown. Here, we report that the gene Pro1404 confers capability for glucose uptake in Prochlorococcus marinus SS120. We used a cyanobacterium unable to take up glucose to engineer strains that express the Pro1404 gene. These recombinant strains were capable of specific glucose uptake over a wide range of glucose concentrations, showing multiphasic transport kinetics. The Ks constant of the high affinity phase was in the nanomolar range, consistent with the average concentration of glucose in the ocean. Furthermore, we were able to observe glucose uptake by Prochlorococcus in the central Atlantic Ocean, where glucose concentrations were 0.5-2.7 nM. Our results suggest that Prochlorococcus are primary producers capable of tuning their metabolism to energetically benefit from environmental conditions, taking up not only organic compounds with key limiting elements in the ocean, but also molecules devoid of such elements, like glucose.

  15. Paper-based microfluidic biofuel cell operating under glucose concentrations within physiological range.

    PubMed

    González-Guerrero, Maria José; Del Campo, F Javier; Esquivel, Juan Pablo; Leech, Dónal; Sabaté, Neus

    2017-04-15

    This work addresses the development of a compact paper-based enzymatic microfluidic glucose/O2 fuel cell that can operate using a very limited sample volume (≈35µl) and explores the energy generated by glucose at concentrations typically found in blood samples at physiological conditions (pH 7.4). Carbon paper electrodes combined with a paper sample absorption substrate all contained within a plastic microfluidic casing are used to construct the paper-based fuel cell. The anode catalysts consist of glucose dehydrogenase and [Os(4,4'-dimethoxy-2,2'-bipyridine)2(poly-vinylimidazole)10Cl](+) as mediator, while the cathode catalysts were bilirubin oxidase and [Os(2,2'-bipyridine)2(poly-vinylimidazole)10Cl](+) as mediator. The fuel cell delivered a linear power output response to glucose over the range of 2.5-30mM, with power densities ranging from 20 to 90µWcm(-2). The quantification of the available electrical power as well as the energy density extracted from small synthetic samples allows planning potential uses of this energy to power different sensors and analysis devices in a wide variety of in-vitro applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Physical and chemical changes in whey protein concentrate stored at elevated temperature and humidity

    USDA-ARS?s Scientific Manuscript database

    The chemistry of whey protein concentrate (WPC) under adverse storage conditions was monitored to provide information on shelf life in hot, humid areas. WPC34 (34.9 g protein/100 g) and WPC80 (76.8 g protein/100 g) were stored for up to 18 mo under ambient conditions and at elevated temperature and...

  17. Glucose concentration alters dissolved oxygen levels in liquid cultures of Beauveria bassiana and affects formation and bioefficacy of blastospores.

    PubMed

    Mascarin, Gabriel Moura; Jackson, Mark A; Kobori, Nilce Naomi; Behle, Robert W; Dunlap, Christopher A; Delalibera Júnior, Ítalo

    2015-08-01

    The filamentous fungus Beauveria bassiana is an economically important pathogen of numerous arthropod pests and is able to grow in submerged culture as filaments (mycelia) or as budding yeast-like blastospores. In this study, we evaluated the effect of dissolved oxygen and high glucose concentrations on blastospore production by submerged cultures of two isolates of B. bassiana, ESALQ1432 and GHA. Results showed that maintaining adequate dissolved oxygen levels coupled with high glucose concentrations enhanced blastospore yields by both isolates. High glucose concentrations increased the osmotic pressure of the media and coincided with higher dissolved oxygen levels and increased production of significantly smaller blastospores compared with blastospores produced in media with lower concentrations of glucose. The desiccation tolerance of blastospores dried to less than 2.6 % moisture was not affected by the glucose concentration of the medium but was isolate dependent. Blastospores of isolate ESALQ1432 produced in media containing 140 g glucose L(-1) showed greater virulence toward whitefly nymphs (Bemisia tabaci) as compared with blastospores produced in media containing 40 g glucose L(-1). These results suggest a synergistic effect between glucose concentration and oxygen availability on changing morphology and enhancing the yield and efficacy of blastospores of B. bassiana, thereby facilitating the development of a cost-effective production method for this blastospore-based bioinsecticide.

  18. Effect of Food Thickener on the Inhibitory Effect of Mitiglinide Tablets on Post-prandial Elevation of Blood Glucose Levels.

    PubMed

    Tomita, Takashi; Goto, Hidekazu; Sumiya, Kenji; Yoshida, Tadashi; Tanaka, Katsuya; Kudo, Kenzo; Kohda, Yukinao

    2017-03-07

    The aim of this study was to examine the effect of food thickener on the pharmacodynamics of mitiglinide (MGN), a drug belonging to a class of rapid-acting insulin secretagogues. First, MGN tablets were coated by immersion in a xanthan gum-based food-thickening agent. This treatment was shown to delay disintegration rates of MGN tablets in vitro. The pharmacodynamics of MGN after ingestion of a single oral dose of an MGN tablet, with or without food thickener immersion, were then examined in an open-label crossover study comprising 5 healthy participants. It was observed that after administration of 75 g of oral glucose, the area under the blood glucose concentration-time curve was larger for treatment with MGN tablets that had been immersed in the food thickener than for nonimmersed tablets. The maximum blood glucose level was also higher in treatments with MGN tablets that had been immersed in food thickener. The extended time of higher glucose levels associated with thickener-immersed MGN tablets given to human volunteers may be associated with the reduced disintegration rates of immersed MGN tablets as observed in the in vitro experiment. Overall, our study suggests that commercially available food thickeners influence the pharmacodynamics of MGN and that their use should therefore be carefully assessed and monitored in certain clinical situations.

  19. Study on the mechanism of human blood glucose concentration measuring using mid-infrared spectral analysis technology

    NASA Astrophysics Data System (ADS)

    Li, Xiang

    2016-10-01

    All forms of diabetes increase the risk of long-term complications. Blood glucose monitoring is of great importance for controlling diabetes procedure, preventing the complications and improving the patient's life quality. At present, the clinical blood glucose concentration measurement is invasive and could be replaced by noninvasive spectroscopy analytical techniques. The mid-infrared spectral region contains strong characteristic and well-defined absorption bands. Therefore, mid-infrared provides an opportunity for monitoring blood glucose invasively with only a few discrete bonds. Although the blood glucose concentration measurement using mid-infrared spectroscopy has a lot of advantages, the disadvantage is also obvious. The absorption in this infrared region is fundamental molecular group vibration. Absorption intensity is very strong, especially for biological molecules. In this paper, it figures out that the osmosis rate of glucose has a certain relationship with the blood glucose concentration. Therefore, blood glucose concentration could be measured indirectly by measuring the glucose exudate in epidermis layer. Human oral glucose tolerance tests were carried out to verify the correlation of glucose exudation in shallow layer of epidermis layer and blood glucose concentration. As it has been explained above, the mid-infrared spectral region contains well-defined absorption bands, the intensity of absorption peak around 1123 cm-1 was selected to measure the glucose and that around 1170 cm-1 was selected as reference. Ratio of absorption peak intensity was recorded for each set of measurement. The effect and importance of the cleaning the finger to be measured before spectrum measuring are discussed and also verified by experiment.

  20. Acute ingestion of catechin-rich green tea improves postprandial glucose status and increases serum thioredoxin concentrations in postmenopausal women.

    PubMed

    Takahashi, Masaki; Miyashita, Masashi; Suzuki, Katsuhiko; Bae, Seong-Ryu; Kim, Hyeon-Ki; Wakisaka, Takuya; Matsui, Yuji; Takeshita, Masao; Yasunaga, Koichi

    2014-11-14

    Elevated postprandial hyperglycaemia and oxidative stress increase the risks of type 2 diabetes and CVD. Green tea catechin possesses antidiabetic properties and antioxidant capacity. In the present study, we examined the acute and continuous effects of ingestion of catechin-rich green tea on postprandial hyperglycaemia and oxidative stress in healthy postmenopausal women. Participants were randomly assigned into the placebo (P, n 11) or green tea (GT, n 11) group. The GT group consumed a catechin-rich green tea (catechins 615 mg/350 ml) beverage per d for 4 weeks. The P group consumed a placebo (catechins 92 mg/350 ml) beverage per d for 4 weeks. At baseline and after 4 weeks, participants of each group consumed their designated beverages with breakfast and consumed lunch 3 h after breakfast. Venous blood samples were collected in the fasted state (0 h) and at 2, 4 and 6 h after breakfast. Postprandial glucose concentrations were 3 % lower in the GT group than in the P group (three-factor ANOVA, group × time interaction, P< 0·05). Serum concentrations of the derivatives of reactive oxygen metabolites increased after meals (P< 0·05), but no effect of catechin-rich green tea intake was observed. Conversely, serum postprandial thioredoxin concentrations were 5 % higher in the GT group than in the P group (three-factor ANOVA, group × time interaction, P< 0·05). These findings indicate that an acute ingestion of catechin-rich green tea has beneficial effects on postprandial glucose and redox homeostasis in postmenopausal women.

  1. Effects of basswood honey, honey-comparable glucose-fructose solution, and oral glucose tolerance test solution on serum insulin, glucose, and C-peptide concentrations in healthy subjects.

    PubMed

    Münstedt, Karsten; Sheybani, Babak; Hauenschild, Annette; Brüggmann, Dörthe; Bretzel, Reinhard G; Winter, Daniel

    2008-09-01

    Studies suggest that honey has less influence on serum glucose concentrations than monosaccharides and disaccharides. This study aimed to confirm these findings conclusively by comparing directly the effects of honey, an identical sugar solution, and oral glucose tolerance (OGT) test solution on serum glucose, insulin, and C-peptide values in healthy subjects. Twelve healthy men with a mean age of 27.7 years, a mean body mass index of 23.2 kg/m(2), and no history of metabolic disorders participated in the study. Subjects underwent OGT testing to establish values and exclude preclinical diabetes. One week later they were randomly assigned to basswood honey or a glucose-fructose solution (honey-comparable glucose-fructose solution). The following week subjects were given the other solution. All solutions contained 75 g of glucose. Serum glucose was measured before drinking test solutions and every 10 minutes for 120 minutes afterwards. C-peptide and insulin were measured at 60 and 120 minutes. Serum insulin and C-peptide values at 60 minutes were significantly lower for honey. The mean serum glucose concentration was also lower for honey, but direct comparisons at the various times showed no statistically significant differences between solutions. However, the area under the concentration-time profile for glucose response was lower for the honey than the honey-comparable glucose-fructose solution. Honey had less effect on serum glucose, C-peptide, and insulin values than the honey-comparable glucose-fructose solution. Further study to elucidate underlying mechanisms may be worthwhile, as may investigation of the implications of these findings for diabetic patients.

  2. Improvement of embryonic stem cell line derivation efficiency with novel medium, glucose concentration, and epigenetic modifications.

    PubMed

    Kim, Chul; Amano, Tomokazu; Park, Joonghoon; Carter, Mark G; Tian, Xiuchun; Yang, Xiangzhong

    2009-03-01

    Although the first mouse embryonic stem (ES) cell lines were derived 2 decades ago, and standard protocols for ES cell derivation are widely used today, the technical difficulty of these protocols still pose a challenge for many investigators attempting to produce large numbers of ES cell lines, and are limited to only a few mouse strains. Recently, glucose concentration was shown to have a significant effect on the efficiency of ES cell derivation, but the mechanism(s) mediating this effect are still the subject of debate. In this report, we investigated the effect of glucose concentration on ES cell derivation efficiency from blastocysts in the context of a new medium, Minimum Essential Medium alpha (MEMalpha). Furthermore, we propose novel methods to improve mouse ES cell derivation efficiency using in vitro epigenetic modifications during early passages, combined with detection of Oct4-expressing cells. Based on the results reported here, modified MEMalpha containing high glucose improves the efficiency of ES cell derivation remarkably, compared with Knockout Dulbecco's-Modified Eagle Media (KDMEM). Epigenetic modifications are able to improve the efficiency even further.

  3. SGLT1 activity in lung alveolar cells of diabetic rats modulates airway surface liquid glucose concentration and bacterial proliferation

    PubMed Central

    Oliveira, Tales Lyra; Candeia-Medeiros, Návylla; Cavalcante-Araújo, Polliane M.; Melo, Igor Santana; Fávaro-Pípi, Elaine; Fátima, Luciana Alves; Rocha, Antônio Augusto; Goulart, Luiz Ricardo; Machado, Ubiratan Fabres; Campos, Ruy R.; Sabino-Silva, Robinson

    2016-01-01

    High glucose concentration in the airway surface liquid (ASL) is an important feature of diabetes that predisposes to respiratory infections. We investigated the role of alveolar epithelial SGLT1 activity on ASL glucose concentration and bacterial proliferation. Non-diabetic and diabetic rats were intranasally treated with saline, isoproterenol (to increase SGLT1 activity) or phlorizin (to decrease SGLT1 activity); 2 hours later, glucose concentration and bacterial proliferation (methicillin-resistant Sthaphylococcus aureus, MRSA and Pseudomonas aeruginosa, P. aeruginosa) were analyzed in bronchoalveolar lavage (BAL); and alveolar SGLT1 was analyzed by immunohistochemistry. BAL glucose concentration and bacterial proliferation increased in diabetic animals: isoproterenol stimulated SGLT1 migration to luminal membrane, and reduced (50%) the BAL glucose concentration; whereas phlorizin increased the BAL glucose concentration (100%). These regulations were accompanied by parallel changes of in vitro MRSA and P. aeruginosa proliferation in BAL (r = 0.9651 and r = 0.9613, respectively, Pearson correlation). The same regulations were observed in in vivo P. aeruginosa proliferation. In summary, the results indicate a relationship among SGLT1 activity, ASL glucose concentration and pulmonary bacterial proliferation. Besides, the study highlights that, in situations of pulmonary infection risk, such as in diabetic subjects, increased SGLT1 activity may prevent bacterial proliferation whereas decreased SGLT1 activity can exacerbate it. PMID:26902517

  4. Elevated Concentration of Defensins in Hepatitis C Virus-Infected Patients

    PubMed Central

    Mattar, Ehab H.; Almehdar, Hussein A.; AlJaddawi, Abdullah A.; Abu Zeid, Isam ElDin M.; Redwan, Elrashdy M.

    2016-01-01

    Hepatitis C virus (HCV) is the major etiological agent of human non-A and non-B hepatitis, affecting around 180 million people worldwide. Defensins, small cysteine-rich cationic peptides, are shown to have potent antibacterial, antiviral, and antifungal properties. Defensins can be found in both normal and microbial infected patients, at variable concentrations. Notably, viral infections are often associated with elevated concentrations of defensins. The current study aimed to estimate the concentrations of total, α-, and β-defensins in serum taken from normal and HCV-infected patients. 12 healthy (noninfected) and 34 HCV-infected patients were enrolled. Standardized immunoassay kits were used to obtain serum concentrations of defensins. The obtained results were calibrated against kit standard reagents. Total defensin concentrations in HCV-infected patients were significantly higher (2- to 105-fold) compared to healthy individuals. The concentrations of α-defensins were also significantly elevated in the HCV-infected patients (31–1398 ng/50 μL). However, concentrations of β-defensins ranged from 44.5 ng/50 μL to 1056 ng/50 μL. The results did not reveal differences in serum defensin concentration between male and female HCV-infected patients. A-defensin concentration of ≥250 ng/50 μL was found to contain more β-defensins than total defensins and α-defensins. This study concludes, for the first time, that serum defensin levels are elevated in HCV-infected patients. PMID:27413763

  5. Incidental findings of elevated random plasma glucose in the ED as a prompt for outpatient diabetes screening: a retrospective study

    PubMed Central

    Friedman, Steven Marc; Vallipuram, Janaki; Baswick, Brenda

    2013-01-01

    Objective To determine whether random plasma glucose (RPG) collected from patients without known impaired glucose metabolism (IGM) in the emergency department (ED) is a useful screen for diabetes or prediabetes. Design Retrospective cohort study. Setting ED of a Canadian teaching hospital over 1 month. Participants Adult patients in ED with RPG over 7 mmol/L were recruited for participation. Exclusion criteria included known diabetes, hospital admission and inability to consent. Participants were contacted by mail, encouraged to follow-up with their family physician (FP) for further testing and subsequently interviewed. Outcome measures The primary outcome measure was the proportion of patients in the ED with RPG over 7 mmol/L and no previous diagnosis of IGM who were diagnosed with diabetes or prediabetes after secondary testing by FP with oral glucose tolerance test or fasting plasma glucose (FPG). Secondary outcomes included patient characteristics (age, gender, body mass index and language) and (2) compliance with advice to seek an appropriate follow-up care. Results RPG was drawn on approximately one-third (33%, n=1149) of the 3470 patients in the ED in March 2010. RPG over 7 mmol/L was detected in 24% (n=278) of patients, and after first telephone follow-up, 32% (n=88/278) met the inclusion criteria and were advised to seek confirmatory testing. 41% (n=114/278) of patients were excluded for known diabetes. 73% of patients contacted (n=64/88) followed up with their FP. 12.5% (n=11/88) of patients had abnormal FPG, and of these 11% (n=10/88) were encouraged to initiate lifestyle modifications and 1% (n=1/88) was started on an oral hypoglycaemic agent. For 7% (n=6/88) of patients, FP's declined to do follow-up fasting blood work. Conclusions Elevated RPG in the ED is useful for identification of patients at risk for IGM and in need of further diabetic screening. Emergency physicians should advise patients with elevated RPG to consider screening for

  6. Incidental findings of elevated random plasma glucose in the ED as a prompt for outpatient diabetes screening: a retrospective study.

    PubMed

    Friedman, Steven Marc; Vallipuram, Janaki; Baswick, Brenda

    2013-12-18

    To determine whether random plasma glucose (RPG) collected from patients without known impaired glucose metabolism (IGM) in the emergency department (ED) is a useful screen for diabetes or prediabetes. Retrospective cohort study. ED of a Canadian teaching hospital over 1 month. Adult patients in ED with RPG over 7 mmol/L were recruited for participation. Exclusion criteria included known diabetes, hospital admission and inability to consent. Participants were contacted by mail, encouraged to follow-up with their family physician (FP) for further testing and subsequently interviewed. The primary outcome measure was the proportion of patients in the ED with RPG over 7 mmol/L and no previous diagnosis of IGM who were diagnosed with diabetes or prediabetes after secondary testing by FP with oral glucose tolerance test or fasting plasma glucose (FPG). Secondary outcomes included patient characteristics (age, gender, body mass index and language) and (2) compliance with advice to seek an appropriate follow-up care. RPG was drawn on approximately one-third (33%, n=1149) of the 3470 patients in the ED in March 2010. RPG over 7 mmol/L was detected in 24% (n=278) of patients, and after first telephone follow-up, 32% (n=88/278) met the inclusion criteria and were advised to seek confirmatory testing. 41% (n=114/278) of patients were excluded for known diabetes. 73% of patients contacted (n=64/88) followed up with their FP. 12.5% (n=11/88) of patients had abnormal FPG, and of these 11% (n=10/88) were encouraged to initiate lifestyle modifications and 1% (n=1/88) was started on an oral hypoglycaemic agent. For 7% (n=6/88) of patients, FP's declined to do follow-up fasting blood work. Elevated RPG in the ED is useful for identification of patients at risk for IGM and in need of further diabetic screening. Emergency physicians should advise patients with elevated RPG to consider screening for diabetes. For ED screening to be successful, patient education and collaboration with

  7. Sensitive indicators of Stipa bungeana response to precipitation under ambient and elevated CO2 concentration.

    PubMed

    Shi, Yaohui; Zhou, Guangsheng; Jiang, Yanling; Wang, Hui; Xu, Zhenzhu

    2017-09-01

    Precipitation is a primary environmental factor in the semiarid grasslands of northern China. With increased concentrations of atmospheric greenhouse gases, precipitation regimes will change, and high-impact weather events may be more common. Currently, many ecophysiological indicators are known to reflect drought conditions, but these indicators vary greatly among species, and few studies focus on the applicability of these drought indicators under high CO2 conditions. In this study, five precipitation levels (- 30%, - 15%, control, + 15%, and + 30%) were used to simulate the effects of precipitation change on 18 ecophysiological characteristics in Stipa bungeana, including leaf area, plant height, leaf nitrogen (N), and chlorophyll content, among others. Two levels of CO2 concentration (ambient, 390 ppm; 550 ppm) were used to simulate the effects of elevated CO2 on these drought indicators. Using gray relational analysis and phenotypic plasticity analysis, we found that total leaf area or leaf number (morphology), leaf water potential or leaf water content (physiology), and aboveground biomass better reflected the water status of S. bungeana under ambient and elevated CO2 than the 13 other analyzed variables. The sensitivity of drought indicators changed under the elevated CO2 condition. By quantifying the relationship between precipitation and the five most sensitive indicators, we found that the thresholds of precipitation decreased under elevated CO2 concentration. These results will be useful for objective monitoring and assessment of the occurrence and development of drought events in S. bungeana grasslands.

  8. Sensitive indicators of Stipa bungeana response to precipitation under ambient and elevated CO2 concentration

    NASA Astrophysics Data System (ADS)

    Shi, Yaohui; Zhou, Guangsheng; Jiang, Yanling; Wang, Hui; Xu, Zhenzhu

    2017-09-01

    Precipitation is a primary environmental factor in the semiarid grasslands of northern China. With increased concentrations of atmospheric greenhouse gases, precipitation regimes will change, and high-impact weather events may be more common. Currently, many ecophysiological indicators are known to reflect drought conditions, but these indicators vary greatly among species, and few studies focus on the applicability of these drought indicators under high CO2 conditions. In this study, five precipitation levels (- 30%, - 15%, control, + 15%, and + 30%) were used to simulate the effects of precipitation change on 18 ecophysiological characteristics in Stipa bungeana, including leaf area, plant height, leaf nitrogen (N), and chlorophyll content, among others. Two levels of CO2 concentration (ambient, 390 ppm; 550 ppm) were used to simulate the effects of elevated CO2 on these drought indicators. Using gray relational analysis and phenotypic plasticity analysis, we found that total leaf area or leaf number (morphology), leaf water potential or leaf water content (physiology), and aboveground biomass better reflected the water status of S. bungeana under ambient and elevated CO2 than the 13 other analyzed variables. The sensitivity of drought indicators changed under the elevated CO2 condition. By quantifying the relationship between precipitation and the five most sensitive indicators, we found that the thresholds of precipitation decreased under elevated CO2 concentration. These results will be useful for objective monitoring and assessment of the occurrence and development of drought events in S. bungeana grasslands.

  9. Unexpected competitiveness of Methanosaeta populations at elevated acetate concentrations in methanogenic treatment of animal wastewater.

    PubMed

    Chen, Si; Cheng, Huicai; Liu, Jiang; Hazen, Terry C; Huang, Vicki; He, Qiang

    2017-02-01

    Acetoclastic methanogenesis is a key metabolic process in anaerobic digestion, a technology with broad applications in biogas production and waste treatment. Acetoclastic methanogenesis is known to be performed by two archaeal genera, Methanosaeta and Methanosarcina. The conventional model posits that Methanosaeta populations are more competitive at low acetate levels (<1 mM) than Methanosarcina and vice versa at higher acetate concentrations. While this model is supported by an extensive body of studies, reports of inconsistency have grown that Methanosaeta were observed to outnumber Methanosarcina at elevated acetate levels. In this study, monitoring of anaerobic digesters treating animal wastewater unexpectedly identified Methanosaeta as the dominant acetoclastic methanogen population at both low and high acetate levels during organic overloading. The surprising competitiveness of Methanosaeta at elevated acetate was further supported by the enrichment of Methanosaeta with high concentrations of acetate (20 mM). The dominance of Methanosaeta in the methanogen community could be reproduced in anaerobic digesters with the direct addition of acetate to above 20 mM, again supporting the competitiveness of Methanosaeta over Methanosarcina at elevated acetate levels. This study for the first time systematically demonstrated that the dominance of Methanosaeta populations in anaerobic digestion could be linked to the competitiveness of Methanosaeta at elevated acetate concentrations. Given the importance of acetoclastic methanogenesis in biological methane production, findings from this study could have major implications for developing strategies for more effective control of methanogenic treatment processes.

  10. Non-contact optical sensor for detection of glucose concentration using a magneto-optic effect

    NASA Astrophysics Data System (ADS)

    Ozana, Nisan; Beiderman, Yevgeny; Anand, Arun; Javidi, Baharam; Polani, Sagi; Schwarz, Ariel; Shemer, Amir; García, Javier; Zalevsky, Zeev

    2016-03-01

    In this paper we aim to experimentally verify a speckle based technique for non-contact measurement of glucose concentration in blood stream while the vision for the final device aims to contain a single wristwatch-style device containing an AC (alternating) electro-magnet generated by a solenoid, a laser and a camera. The experiments presented in work are performed in-vitro in order to verify the effects that are responsible for the operation principle. When a glucose substance is inserted into a solenoid generating an alternating magnetic field it exhibits Faraday rotation which affects the temporal changes of the secondary speckle patterns distribution. The temporal frequency resulting from the AC magnetic field was found to have a lock-in amplification role which increased the observability of the relatively small magneto-optic effect. Experimental results to support the proposed concept are presented.

  11. Noncontact speckle-based optical sensor for detection of glucose concentration using magneto-optic effect

    NASA Astrophysics Data System (ADS)

    Ozana, Nisan; Beiderman, Yevgeny; Anand, Arun; Javidi, Baharam; Polani, Sagi; Schwarz, Ariel; Shemer, Amir; Garcia, Javier; Zalevsky, Zeev

    2016-06-01

    We experimentally verify a speckle-based technique for noncontact measurement of glucose concentration in the bloodstream. The final device is intended to be a single wristwatch-style device containing a laser, a camera, and an alternating current (ac) electromagnet generated by a solenoid. The experiments presented are performed in vitro as proof of the concept. When a glucose substance is inserted into a solenoid generating an ac magnetic field, it exhibits Faraday rotation, which affects the temporal changes of the secondary speckle pattern distributions. The temporal frequency resulting from the ac magnetic field was found to have a lock-in amplification role, which increased the observability of the relatively small magneto-optic effect. Experimental results to support the proposed concept are presented.

  12. Taurine infused intrastriatally elevates, but intranigrally decreases striatal extracellular dopamine concentration in anaesthetised rats.

    PubMed

    Ruotsalainen, M; Heikkilä, M; Lillsunde, P; Seppälä, T; Ahtee, L

    1996-01-01

    In the present study we infused taurine (50, 150 or 450 mM, 2 microliters/min for 4h) into the dorsal striatum or into the substantia nigra via microdialysis probe and estimated the extracellular concentrations of dopamine and its metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), in the dorsal striatum of anaesthetised rats. Intrastriatal infusion of taurine elevated striatal dopamine at all concentrations studied. At the 450 mM concentration taurine elevated the extracellular dopamine 10-fold, but only in the first 30 min sample after starting the taurine infusion. At 50 and 150 mM taurine elevated dopamine throughout the 4h infusion maximally up to 3-4-fold the control level. Extracellular DOPAC was increased by 150 and 450 mM taurine (up to about 150-160% of the control level), whereas at all three concentrations taurine decreased HVA to about 85% of the control; however, the decrease caused by 450 mM taurine was short-lasting. At all three concentrations taurine infused into the substantia nigra decreased the extracellular dopamine in the ipsilateral striatum to about 40-50% of the control, and increased extracellular DOPAC and HVA maximally to about 150% and 170% of the control, respectively. These results show that the effects of taurine on the concentrations of extracellular dopamine and its metabolites depend on its administration site on nigrostriatal dopaminergic neurons. It elevates the extracellular dopamine when given into the striatum, but when given into the cell body region of the nigrostriatal dopaminergic pathway it decreases the extracellular dopamine in the ipsilateral striatum.

  13. Longitudinal association between fasting blood glucose concentrations and first stroke in hypertensive adults in China: effect of folic acid intervention.

    PubMed

    Xu, Richard B; Kong, Xiangyi; Xu, Benjamin P; Song, Yun; Ji, Meng; Zhao, Min; Huang, Xiao; Li, Ping; Cheng, Xiaoshu; Chen, Fang; Zhang, Yan; Tang, Genfu; Qin, Xianhui; Wang, Binyan; Hou, Fan Fan; Dong, Qiang; Chen, Yundai; Yang, Tianlun; Sun, Ningling; Li, Xiaoying; Zhao, Lianyou; Ge, Junbo; Ji, Linong; Huo, Yong; Li, Jianping

    2017-03-01

    Background: Diabetes is a known risk factor for stroke, but data on its prospective association with first stroke are limited. Folic acid supplementation has been shown to protect against first stroke, but its role in preventing first stroke in diabetes is unknown.Objectives: This post hoc analysis of the China Stroke Primary Prevention Trial tested the hypotheses that the fasting blood glucose (FBG) concentration is positively associated with first stroke risk and that folic acid treatment can reduce stroke risk associated with elevated fasting glucose concentrations.Design: This analysis included 20,327 hypertensive adults without a history of stroke or myocardial infarction, who were randomly assigned to a double-blind daily treatment with 10 mg enalapril and 0.8 mg folic acid (n = 10,160) or 10 mg enalapril alone (n = 10,167). Kaplan-Meier survival analysis and Cox proportionate hazard models were used to test the hypotheses with adjustment for pertinent covariables.Results: During a median treatment duration of 4.5 y, 616 participants developed a first stroke (497 ischemic strokes). A high FBG concentration (≥7.0 mmol/L) or diabetes, compared with a low FBG concentration (<5.0 mmol/L), was associated with an increased risk of first stroke (6.0% compared with 2.6%, respectively; HR: 1.9; 95% CI: 1.3, 2.8; P < 0.001). Folic acid treatment reduced the risk of stroke across a wide range of FBG concentrations ≥5.0 mmol/L, but risk reduction was greatest in subjects with FBG concentrations ≥7.0 mmol/L or with diabetes (HR: 0.66; 95% CI: 0.46, 0.97; P < 0.05). There was a significant interactive effect of FBG and folic acid treatment on first stroke (P = 0.01).Conclusions: In Chinese hypertensive adults, an FBG concentration ≥7.0 mmol/L or diabetes is associated with an increased risk of first stroke; this increased risk is reduced by 34% with folic acid treatment. These findings warrant additional investigation. This trial was registered at clinicaltrials

  14. Monoterpene and herbivore-induced emissions from cabbage plants grown at elevated atmospheric CO 2 concentration

    NASA Astrophysics Data System (ADS)

    Vuorinen, Terhi; Reddy, G. V. P.; Nerg, Anne-Marja; Holopainen, Jarmo K.

    The warming of the lower atmosphere due to elevating CO 2 concentration may increase volatile organic compound (VOC) emissions from plants. Also, direct effects of elevated CO 2 on plant secondary metabolism are expected to lead to increased VOC emissions due to allocation of excess carbon on secondary metabolites, of which many are volatile. We investigated how growing at doubled ambient CO 2 concentration affects emissions from cabbage plants ( Brassica oleracea subsp. capitata) damaged by either the leaf-chewing larvae of crucifer specialist diamondback moth ( Plutella xylostella L.) or generalist Egyptian cotton leafworm ( Spodoptera littoralis (Boisduval)). The emission from cabbage cv. Lennox grown in both CO 2 concentrations, consisted mainly of monoterpenes (sabinene, limonene, α-thujene, 1,8-cineole, β-pinene, myrcene, α-pinene and γ-terpinene). ( Z)-3-Hexenyl acetate, sesquiterpene ( E, E)- α-farnesene and homoterpene ( E)-4,8-dimethyl-1,3,7-nonatriene (DMNT) were emitted mainly from herbivore-damaged plants. Plants grown at 720 μmol mol -1 of CO 2 had significantly lower total monoterpene emissions per shoot dry weight than plants grown at 360 μmol mol -1 of CO 2, while damage by both herbivores significantly increased the total monoterpene emissions compared to intact plants. ( Z)-3-Hexenyl acetate, ( E, E)- α-farnesene and DMNT emissions per shoot dry weight were not affected by the growth at elevated CO 2. The emission of DMNT was significantly enhanced from plants damaged by the specialist P. xylostella compared to the plants damaged by the generalist S. littoralis. The relative proportions of total monoterpenes and total herbivore-induced compounds of total VOCs did not change due to the growth at elevated CO 2, while insect damage increased significantly the proportion of induced compounds. The results suggest that VOC emissions that are induced by the leaf-chewing herbivores will not be influenced by elevated CO 2 concentration.

  15. Extremely high intracellular concentration of glucose-6-phosphate and NAD(H) in Deinococcus radiodurans.

    PubMed

    Yamashiro, Takumi; Murata, Kousaku; Kawai, Shigeyuki

    2017-03-01

    Deinococcus radiodurans is highly resistant to ionizing radiation and UV radiation, and oxidative stress caused by such radiations. NADP(H) seems to be important for this resistance (Slade and Radman, Microbiol Mol Biol Rev 75:133-191; Slade, Radman, Microbiol Mol Biol Rev 75:133-191, 2011), but the mechanism underlying the generation of NADP(H) or NAD(H) in D. radiodurans has not fully been addressed. Intracellular concentrations of NAD(+), NADH, NADP(+), and NADPH in D. radiodurans are also not determined yet. We found that cell extracts of D. radiodurans catalyzed reduction of NAD(P)(+) in vitro, indicating that D. radiodurans cells contain both enzymes and a high concentration of substrates for this activity. The enzyme and the substrate were attributed to glucose-6-phosphate dehydrogenase and glucose-6-phosphate of which intracellular concentration was extremely high. Unexpectedly, the intracellular concentration of NAD(H) was also much greater than that of NADP(H), suggesting some significant roles of NADH. These unusual features of this bacterium would shed light on a new aspect of physiology of this bacterium.

  16. Estimating the Probability of Elevated Nitrate Concentrations in Ground Water in Washington State

    USGS Publications Warehouse

    Frans, Lonna M.

    2008-01-01

    Logistic regression was used to relate anthropogenic (manmade) and natural variables to the occurrence of elevated nitrate concentrations in ground water in Washington State. Variables that were analyzed included well depth, ground-water recharge rate, precipitation, population density, fertilizer application amounts, soil characteristics, hydrogeomorphic regions, and land-use types. Two models were developed: one with and one without the hydrogeomorphic regions variable. The variables in both models that best explained the occurrence of elevated nitrate concentrations (defined as concentrations of nitrite plus nitrate as nitrogen greater than 2 milligrams per liter) were the percentage of agricultural land use in a 4-kilometer radius of a well, population density, precipitation, soil drainage class, and well depth. Based on the relations between these variables and measured nitrate concentrations, logistic regression models were developed to estimate the probability of nitrate concentrations in ground water exceeding 2 milligrams per liter. Maps of Washington State were produced that illustrate these estimated probabilities for wells drilled to 145 feet below land surface (median well depth) and the estimated depth to which wells would need to be drilled to have a 90-percent probability of drawing water with a nitrate concentration less than 2 milligrams per liter. Maps showing the estimated probability of elevated nitrate concentrations indicated that the agricultural regions are most at risk followed by urban areas. The estimated depths to which wells would need to be drilled to have a 90-percent probability of obtaining water with nitrate concentrations less than 2 milligrams per liter exceeded 1,000 feet in the agricultural regions; whereas, wells in urban areas generally would need to be drilled to depths in excess of 400 feet.

  17. High glucose concentrations alter the biomineralization process in human osteoblastic cells.

    PubMed

    García-Hernández, A; Arzate, H; Gil-Chavarría, I; Rojo, R; Moreno-Fierros, L

    2012-01-01

    Diabetes mellitus (DM) may alter bone remodeling, as osteopenia and osteoporosis are among the complications. Moreover, DM increases the risk and severity of chronic inflammatory periodontal disease, in which bone resorption occurs. Broad evidence suggests that chronic inflammation can contribute to the development of DM and its complications. Hyperglycemia is a hallmark of DM that may contribute to sustained inflammation by increasing proinflammatory cytokines, which are known to cause insulin resistance, via toll-like receptor (TLR)-4-mediated mechanisms. However, the mechanisms by which bone-related complications develop in DM are still unknown. Studies done on the effect of high glucose concentrations on osteoblast functions are contradictory because some suggest increases (although others suggest reductions) in the biomineralization process. Therefore, we evaluated the effect of high glucose levels on biomineralization and inflammation markers in a human osteoblastic cell line. Cells were treated with either physiological 5.5 mM or increasing concentrations of glucose up to 24 mM, and we determined the following: i) the quantity and quality of calcium-deposit crystals in culture and ii) the expression of the following: a) proteins associated with the process of biomineralization, b) the receptor activator of nuclear factor kappa-B ligand (RANKL) and osteoprotegerin (OPG), c) cytokines IL1, IL6, IL8, IL10, MCP-1 and TNF alpha, and d) TLR-2, -3, -4 and -9. Our results show that high glucose concentrations (12 mM and particularly 24 mM) alter the biomineralization process in osteoblastic cells and provoke the following: i) a rise in mineralization, ii) an increase in the mRNA expression of RANKL and a decrease of OPG, iii) an increase in the mRNA expression of osteocalcin, bone sialoprotein and the transcription factor Runx2, iv) a diminished quality of the mineral, and v) an increase in the expression of IL1beta, IL6, IL8, MCP-1 and IL10 mRNAs. In addition we

  18. Aqueous Fraction of Beta vulgaris Ameliorates Hyperglycemia in Diabetic Mice due to Enhanced Glucose Stimulated Insulin Secretion, Mediated by Acetylcholine and GLP-1, and Elevated Glucose Uptake via Increased Membrane Bound GLUT4 Transporters

    PubMed Central

    Kabir, Ashraf Ul; Samad, Mehdi Bin; Ahmed, Arif; Jahan, Mohammad Rajib; Akhter, Farjana; Tasnim, Jinat; Hasan, S. M. Nageeb; Sayfe, Sania Sarker; Hannan, J. M. A.

    2015-01-01

    Background The study was designed to investigate the probable mechanisms of anti-hyperglycemic activity of B. Vulgaris. Methodology/Principal Findings Aqueous fraction of B. Vulgaris extract was the only active fraction (50mg/kg). Plasma insulin level was found to be the highest at 30 mins after B. Vulgaris administration at a dose of 200mg/kg. B. Vulgaris treated mice were also assayed for plasma Acetylcholine, Glucagon Like Peptide-1 (GLP-1), Gastric Inhibitory Peptide (GIP), Vasoactive Intestinal Peptide, Pituitary Adenylate Cyclase-Activating Peptide (PACAP), Insulin Like Growth Factor-1 (IGF-1), Pancreatic Polypeptides (PP), and Somatostatin, along with the corresponding insulin levels. Plasma Acetylcholine and GLP-1 significantly increased in B. Vulgaris treated animals and were further studied. Pharmacological enhancers, inhibitors, and antagonists of Acetylcholine and GLP-1 were also administered to the test animals, and corresponding insulin levels were measured. These studies confirmed the role of acetylcholine and GLP-1 in enhanced insulin secretion (p<0.05). Principal signaling molecules were quantified in isolated mice islets for the respective pathways to elucidate their activities. Elevated concentrations of Acetylcholine and GLP-1 in B. Vulgaris treated mice were found to be sufficient to activate the respective pathways for insulin secretion (p<0.05). The amount of membrane bound GLUT1 and GLUT4 transporters were quantified and the subsequent glucose uptake and glycogen synthesis were assayed. We showed that levels of membrane bound GLUT4 transporters, glucose-6-phosphate in skeletal myocytes, activity of glycogen synthase, and level of glycogen deposited in the skeletal muscles all increased (p<0.05). Conclusion Findings of the present study clearly prove the role of Acetylcholine and GLP-1 in the Insulin secreting activity of B. Vulgaris. Increased glucose uptake in the skeletal muscles and subsequent glycogen synthesis may also play a part in

  19. High glucose concentrations attenuate hypoxia-inducible factor-1{alpha} expression and signaling in non-tumor cells

    SciTech Connect

    Dehne, Nathalie; Bruene, Bernhard

    2010-04-15

    Hypoxia-inducible factor (HIF) is the major transcription factor mediating adaption to hypoxia e.g. by enhancing glycolysis. In tumor cells, high glucose concentrations are known to increase HIF-1{alpha} expression even under normoxia, presumably by enhancing the concentration of tricarboxylic acid cycle intermediates, while reactions of non-tumor cells are not well defined. Therefore, we analyzed cellular responses to different glucose concentrations in respect to HIF activation comparing tumor to non-tumor cells. Using cells derived from non-tumor origin, we show that HIF-1{alpha} accumulation was higher under low compared to high glucose concentrations. Low glucose allowed mRNA expression of HIF-1 target genes like adrenomedullin. Transfection of C{sub 2}C{sub 12} cells with a HIF-1{alpha} oxygen-dependent degradation domaine-GFP fusion protein revealed that prolyl hydroxylase (PHD) activity is impaired at low glucose concentrations, thus stabilizing the fusion protein. Mechanistic considerations suggested that neither O{sub 2} redistribution nor an altered redox state explains impaired PHD activity in the absence of glucose. In order to affect PHD activity, glucose needs to be metabolized. Amino acids present in the medium also diminished HIF-1{alpha} expression, while the addition of fatty acids did not. This suggests that glucose or amino acid metabolism increases oxoglutarate concentrations, which enhances PHD activity in non-tumor cells. Tumor cells deprived of glutamine showed HIF-1{alpha} accumulation in the absence of glucose, proposing that enhanced glutaminolysis observed in many tumors enables these cells to compensate reduced oxoglutarate production in the absence of glucose.

  20. Effects of blood glucose concentration on ratings of perceived exertion during prolonged low-intensity physical exercise.

    PubMed

    Tabata, I; Kawakami, A

    1991-01-01

    The purpose of this investigation was to determine the relationship between blood glucose concentration and perceived exertion during prolonged low-intensity exercise. After a 12-h overnight fast, seven young healthy males began bicycle exercise from 0800 h at 50% Vo2max. One hour after initiation of the exercise, 20% glucose was infused by means of an infusion pump, to maintain blood glucose concentration at a level of approximately 6.5 mM for 20 min. This was followed by 20 min of sham infusion (no glucose). This 40-min cycle was repeated until 220 min of exercise. During the first 120 min of exercise, the ratings of perceived exertion (RPE) increased gradually without any effects of the glucose infusion. Thereafter, RPE tended to decrease during glucose infusion, and finally showed a significant decrease from 180 (17 +/- 2) to 190 (16 +/- 2) min. This result showed that an increase in blood glucose concentration has a significant effect on perceived exertion, even if exercise time is prolonged. The different responses of RPE during the two phases of the exercise may be explained by the difference of glycogen concentration in muscle, because glucose infusion had no effect on RPE when muscle glycogen content was presumed to be at normal level, and was effective when glycogen in the exercising muscles was presumed to be depleted.

  1. Concentration of Rutin Model Solutions from Their Mixtures with Glucose Using Ultrafiltration

    PubMed Central

    Wei, Swallow; Hossain, Md. M.; Saleh, Zaid S.

    2010-01-01

    Separation of polyphenolic phytochemical compounds from their mixtures with sugars is necessary to produce an added-value sugar-reduced extract with high biological activity from fruit juice processing industry waste streams. The separation characteristics of a binary mixture of rutin and glucose using a Pellicon-2 regenerated cellulose ultrafiltration membrane with an area of 0.1 m2 having nominal MWCO of 1,000 Da were investigated, to demonstrate the separation of phenolic compounds from sugars. The effects of the operating variables–transmembrane pressure, feed solution temperature and pH, initial feed concentration and feed flow rate–on the permeate flux and enrichment of rutin, were determined. The permeate flux increased with the increase in transmembrane pressure up to a certain limit and after that the flux remained more or less constant. The optimum transmembrane pressure was within 4–5 bar. The flux increased with the increase in feed solution temperature because of reduced feed viscosity, and better solubility. The concentration of rutin was optimum at lower temperature (30°C), with an enrichment factor of 1.3. The effect of pH on permeate flux was less obvious. Lowering the feed solution pH increased the retention of rutin and the optimum separation was obtained within pH 3–4. The permeate flux decreased with the increase in feed concentration of rutin (concentration range 0.1–0.5 g/L). The enrichment of rutin was significant in the glucose concentration range 0.35–0.5 g/L. The feed flow rate had a significant effect on the flux and separation characteristics. Higher cross-flow through the membrane reduced the fouling by providing a shear force to sweep away deposited materials from the membrane surface. At high feed flow rate, more rutin was retained by the membrane with less sugar permeating through. The optimum feed flow rate was 1.5 L/min. For the separation of rutin (in the retentate) and glucose (in the permeate), the best results

  2. Effect of elevated oxygen concentration on bacteria, yeasts, and cells propagated for production of biological compounds.

    PubMed

    Baez, Antonino; Shiloach, Joseph

    2014-12-19

    The response of bacteria, yeast, and mammalian and insects cells to oxidative stress is a topic that has been studied for many years. However, in most the reported studies, the oxidative stress was caused by challenging the organisms with H2O2 and redox-cycling drugs, but not by subjecting the cells to high concentrations of molecular oxygen. In this review we summarize available information about the effect of elevated oxygen concentrations on the physiology of microorganisms and cells at various culture conditions. In general, increased oxygen concentrations promote higher leakage of reactive oxygen species (superoxide and H2O2) from the respiratory chain affecting metalloenzymes and DNA that in turn cause impaired growth and elevated mutagenesis. To prevent the potential damage, the microorganisms and cells respond by activating antioxidant defenses and repair systems. This review described the factors that affect growth properties and metabolism at elevated oxygen concentrations that cells may be exposed to, in bioreactor sparged with oxygen enriched air which could affect the yield and quality of the recombinant proteins produced by high cell density schemes.

  3. [Effects of elevated CO2 concentration on physiological characters of three dwarf ornamental bamboo species].

    PubMed

    Zhuang, Ming-Hao; Chen, Shuang-Lin; Li, Ying-Chun; Guo, Zi-Wu; Yang, Qing-Ping

    2013-09-01

    By using open-top chambers (OTCs) to simulate the scenes of elevated CO2 concentrations [500 micromol x mol(-1) (T1) and 700 micromol x mol(-1) (T2)], and taking ambient atmospheric CO2 concentration as the control (CK), this paper studied the effects of elevated CO2 concentration on the lipid peroxidation and anti-oxidation enzyme system in Indocalamus decorus, Pleioblastus kongosanensis, and Sasa glabra leaves. After 103 days treatment, the O2(-)* and MDA contents, relative electron conduction, and soluble sugar content in the three dwarf ornamental bamboo species leaves in T1 had no obvious change, but the activities of anti-oxidation enzymes (SOD, POD, CAT, and APX) changed to a certain extent. In T2, the MDA content and relative electron conduction had no obvious change, but the O2(-)* and soluble sugar contents and the anti-oxidation enzymes activities changed obviously. The adaptation capacity of the three bamboo species to elevated CO2 concentration was in the order of I. decorus > P. kongosanensis > S. glabra.

  4. Soluble TRAIL Concentration in Serum Is Elevated in People with Hypercholesterolemia

    PubMed Central

    Cheng, Wen; Liu, Fangfang; Wang, Zhe; Zhang, Yun; Zhao, Yu-Xia; Zhang, Qunye; Jiang, Fan

    2015-01-01

    Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a multi-functional cytokine, which is involved in the pathophysiological processes of cardiovascular and metabolic diseases. Previously, we demonstrated that TRAIL stimulated lipid uptake and foam cell formation in macrophages in vitro. Several clinical studies have suggested that the serum concentration of TRAIL may be increased in humans with elevated blood cholesterol; however, the current data appear to be inconclusive in this regard. In the present study, we examined the relationships between the serum TRAIL concentration and cholesterol levels in 352 generally healthy subjects undergoing the routine annual health check. We showed that there were significant correlations between TRAIL concentration and levels of total and low-density lipoprotein cholesterols. The level of TRAIL was significantly elevated in subjects with hypercholesterolemia, although this relationship might be also associated with changes of other metabolic factors. Moreover, we showed that the level of blood cholesterol was significantly higher in subjects in the upper quartile of serum TRAIL. In conclusion, our data demonstrate that the serum TRAIL concentration is elevated in people with hypercholesterolemia. PMID:26633016

  5. The effect of insulin on plasma glucose concentrations, expression of hepatic glucose transporters and key gluconeogenic enzymes during the perinatal period in broiler chickens.

    PubMed

    Franssens, Lies; Lesuisse, Jens; Wang, Yufeng; Willems, Els; Willemsen, Hilke; Koppenol, Astrid; Guo, Xiaoquan; Buyse, Johan; Decuypere, Eddy; Everaert, Nadia

    2016-06-01

    Chickens have blood glucose concentrations that are twofold higher than those observed in mammals. Moreover, the insulin sensitivity seems to decrease with postnatal age in both broiler and layer chickens. However, little is known about the response of insulin on plasma glucose concentrations and mRNA abundance of hepatic glucose transporters 1, 2, 3, 8, 9 and 12 (GLUT1, 2, 3, 8, 9 and 12) and three regulatory enzymes of the gluconeogenesis, phosphoenolpyruvate carboxykinase 1 and 2 (PCK1 and 2) or fructose-1,6-biphosphatase 1 (FBP1) in chicks during the perinatal period. In the present study, broiler embryos on embryonic day (ED)16, ED18 or newly-hatched broiler chicks were injected intravenously with bovine insulin (1μg/g body weight (BW)) to examine plasma glucose response and changes in hepatic mRNA abundance of the GLUTs, PCK1 and 2 and FBP1. Results were compared with a non-treated control group and a saline-injected sham group. Plasma glucose levels of insulin-treated ED18 embryos recovered faster from their minimum level than those of insulin-treated ED16 embryos or newly-hatched chicks. In addition, at the minimum plasma glucose level seven hours post-injection (PI), hepatic GLUT2, FBP1 and PCK2 mRNA abundance was decreased in insulin-injected embryos, compared to sham and control groups, being most pronounced when insulin injection occurred on ED16.

  6. The shape of the glucose concentration curve during an oral glucose tolerance test predicts risk for type 1 diabetes.

    PubMed

    Ismail, Heba M; Xu, Ping; Libman, Ingrid M; Becker, Dorothy J; Marks, Jennifer B; Skyler, Jay S; Palmer, Jerry P; Sosenko, Jay M

    2017-09-27

    We aimed to examine: (1) whether specific glucose-response curve shapes during OGTTs are predictive of type 1 diabetes development; and (2) the extent to which the glucose-response curve is influenced by insulin secretion. Autoantibody-positive relatives of people with type 1 diabetes whose baseline OGTT met the definition of a monophasic or biphasic glucose-response curve were followed for the development of type 1 diabetes (n = 2627). A monophasic curve was defined as an increase in OGTT glucose between 30 and 90 min followed by a decline of ≥ 0.25 mmol/l between 90 and 120 min. A biphasic response curve was defined as a decrease in glucose after an initial increase, followed by a second increase of ≥ 0.25 mmol/l. Associations of type 1 diabetes risk with glucose curve shapes were examined using cumulative incidence curve comparisons and proportional hazards regression. C-peptide responses were compared with and without adjustments for potential confounders. The majority of participants had a monophasic curve at baseline (n = 1732 [66%] vs n = 895 [34%]). The biphasic group had a lower cumulative incidence of type 1 diabetes (p < 0.001), which persisted after adjustments for age, sex, BMI z score and number of autoantibodies (p < 0.001). Among the monophasic group, the risk of type 1 diabetes was greater for those with a glucose peak at 90 min than for those with a peak at 30 min; the difference persisted after adjustments (p < 0.001). Compared with the biphasic group, the monophasic group had a lower early C-peptide (30-0 min) response, a lower C-peptide index (30-0 min C-peptide/30-0 min glucose), as well as a greater 2 h C-peptide level (p < 0.001 for all). Those with biphasic glucose curves have a lower risk of progression to type 1 diabetes than those with monophasic curves, and the risk among the monophasic group is increased when the glucose peak occurs at 90 min than at 30 min. Differences in glucose curve shapes between

  7. Elevated mercury concentrations in the feathers of grey-faced petrels (Pterodroma gouldi) in New Zealand.

    PubMed

    Lyver, P O' B; Aldridge, S P; Gormley, A M; Gaw, S; Webb, S; Buxton, R T; Jones, C J

    2017-04-01

    Our objective was to measure the concentrations of Hg, As, Cd, Co, Cr, Cu, Pb, Sb, V and Zn in the body feathers of grey-faced petrel (Pterodroma gouldi), fluttering shearwater (Puffinus gavia), little shearwater (Puffinus assimilis) and common diving petrel (Pelecanoides urinatrix) from breeding colonies in New Zealand between 2006 and 2013. The mean Hg concentration (36.48ppm; SD=9.59) in grey-faced petrel feathers was approximately 8.5 to 14 times that detected in the other three species sampled. We detected no trend or differences in Hg concentrations in grey-faced petrels over the 8years of this study, but Hg concentrations varied between breeding colonies although there was no strong relationship with latitude. The elevated Hg concentrations detected in grey-faced petrels could pose a risk to the breeding performance of grey-faced petrels and the customary harvest of chicks by Māori (New Zealand's indigenous peoples).

  8. Growth and physiological responses of creeping bentgrass (Agrostis stolonifera) to elevated carbon dioxide concentrations.

    PubMed

    Burgess, Patrick; Huang, Bingru

    2014-01-01

    The atmospheric carbon dioxide level has increased and is predicted to continue increasing, which may affect various aspects of plant growth. The objective of this study was to investigate the effects of doubling the carbon dioxide level on the growth and physiological activities of a widely utilized cool-season turfgrass species, creeping bentgrass (Agrostis stolonifera L. 'Penncross'). 'Penncross' plants were established in fritted clay medium and maintained under well-irrigated and well-fertilized conditions in growth chambers. The plants were exposed to either ambient carbon dioxide concentrations (400±10 µmol L(-1)) or elevated carbon dioxide concentrations (800±10 µmol L(-1)) for 12 weeks. Plants grown under elevated carbon dioxide displayed a significantly faster growth rate of their lateral stems (stolons) and increased shoot and root dry weight but a reduced specific leaf area compared to those plants at ambient carbon dioxide levels. Fast stolon growth is a highly desirable trait for turfgrass establishment and recovery from physical damage. The root length and surface area were also increased due to the elevated CO2, which may facilitate water uptake and serve critical drought-avoidance roles when irrigation water is limited. Elevated carbon dioxide caused an increase in the leaf net photosynthetic rate but a reduction in the stomatal conductance and transpiration rate, contributing to improved water use efficiency in creeping bentgrass. Efficient water use is especially important for turfgrass plant survival when irrigation water is limited. Our results suggested that cool-season turfgrass species may greatly benefit from increasingly elevated carbon dioxide concentrations via growth promotion and increasing water use efficiency.

  9. Growth and physiological responses of creeping bentgrass (Agrostis stolonifera) to elevated carbon dioxide concentrations

    PubMed Central

    Burgess, Patrick; Huang, Bingru

    2014-01-01

    The atmospheric carbon dioxide level has increased and is predicted to continue increasing, which may affect various aspects of plant growth. The objective of this study was to investigate the effects of doubling the carbon dioxide level on the growth and physiological activities of a widely utilized cool-season turfgrass species, creeping bentgrass (Agrostis stolonifera L. ‘Penncross’). ‘Penncross’ plants were established in fritted clay medium and maintained under well-irrigated and well-fertilized conditions in growth chambers. The plants were exposed to either ambient carbon dioxide concentrations (400±10 µmol L−1) or elevated carbon dioxide concentrations (800±10 µmol L−1) for 12 weeks. Plants grown under elevated carbon dioxide displayed a significantly faster growth rate of their lateral stems (stolons) and increased shoot and root dry weight but a reduced specific leaf area compared to those plants at ambient carbon dioxide levels. Fast stolon growth is a highly desirable trait for turfgrass establishment and recovery from physical damage. The root length and surface area were also increased due to the elevated CO2, which may facilitate water uptake and serve critical drought-avoidance roles when irrigation water is limited. Elevated carbon dioxide caused an increase in the leaf net photosynthetic rate but a reduction in the stomatal conductance and transpiration rate, contributing to improved water use efficiency in creeping bentgrass. Efficient water use is especially important for turfgrass plant survival when irrigation water is limited. Our results suggested that cool-season turfgrass species may greatly benefit from increasingly elevated carbon dioxide concentrations via growth promotion and increasing water use efficiency. PMID:26504537

  10. Genotypic variation in physiological and growth responses of Populus tremuloides to elevated atmospheric CO2 concentration.

    PubMed

    Wang, X; Curtis, P S; Pregitzer, K S; Zak, D R

    2000-09-01

    Physiological and biomass responses of six genotypes of Populus tremuloides Michx., grown in ambient t (357 micromol mol(-1)) or twice ambient (707 micromol mol(-1)) CO2 concentration ([CO2]) and in low-N or high-N soils, were studied in 1995 and 1996 in northern Lower Michigan, USA. There was a significant CO2 x genotype interaction in photosynthetic responses. Net CO2 assimilation (A) was significantly enhanced by elevated [CO2] for five genotypes in high-N soil and for four genotypes in low-N soil. Enhancement of A by elevated [CO2] ranged from 14 to 68%. Genotypes also differed in their biomass responses to elevated [CO2], but biomass responses were poorly correlated with A responses. There was a correlation between magnitude of A enhancement by elevated [CO2] and stomatal sensitivity to CO2. Genotypes with low stomatal sensitivity to CO2 had a significantly higher A at elevated [CO2] than at ambient [CO2], but elevated [CO2] did not affect the ratio of intercellular [CO2] to leaf surface [CO2]. Stomatal conductance and A of different genotypes responded differentially to recovery from drought stress. Photosynthetic quantum yield and light compensation point were unaffected by elevated [CO2]. We conclude that P. tremuloides genotypes will respond differentially to rising atmospheric [CO2], with the degree of response dependent on other abiotic factors, such as soil N and water availability. The observed genotypic variation in growth could result in altered genotypic representation within natural populations and could affect the composition and structure of plant communities in a higher [CO2] environment in the future.

  11. Tomato–Pseudomonas syringae interactions under elevated CO2 concentration: the role of stomata

    PubMed Central

    Li, Xin; Sun, Zenghui; Shao, Shujun; Zhang, Shuai; Ahammed, Golam Jalal; Zhang, Guanqun; Jiang, Yuping; Zhou, Jie; Xia, Xiaojian; Zhou, Yanhong; Yu, Jingquan; Shi, Kai

    2015-01-01

    Increasing atmospheric CO2 concentrations ([CO2]) in agricultural and natural ecosystems is known to reduce plant stomatal opening, but it is unclear whether these CO2-induced stomatal alterations are associated with foliar pathogen infections. In this study, tomato plants were grown under ambient and elevated [CO2] and inoculated with Pseudomonas syringae pv. tomato strain DC3000, a strain that is virulent on tomato plants. We found that elevated [CO2] enhanced tomato defence against P. syringae. Scanning electron microscopy analysis revealed that stomatal aperture of elevated [CO2] plants was considerably smaller than their ambient counterparts, which affected the behaviour of P. syringae bacteria on the upper surface of epidermal peels. Pharmacological experiments revealed that nitric oxide (NO) played a role in elevated [CO2]-induced stomatal closure. Silencing key genes involved in NO generation and stomatal closing, nitrate reductase (NR) and guard cell slow-type anion channel 1 (SLAC1), blocked elevated [CO2]-induced stomatal closure and resulted in significant increases in P. syringae infection. However, the SLAC1-silenced plants, but not the NR-silenced plants, still had significantly higher defence under elevated [CO2] compared with plants treated with ambient [CO2]. Similar results were obtained when the stomata-limiting factor for P. syringae entry was excluded by syringe infiltration inoculation. These results indicate that elevated [CO2] induces defence against P. syringae in tomato plants, not only by reducing the stomata-mediated entry of P. syringae but also by invoking a stomata-independent pathway to counteract P. syringae. This information is valuable for designing proper strategies against bacterial pathogens under changing agricultural and natural ecosystems. PMID:25336683

  12. FOXO3a governs early and late apoptotic endothelial programs during elevated glucose through mitochondrial and caspase signaling.

    PubMed

    Hou, Jinling; Chong, Zhao Zhong; Shang, Yan Chen; Maiese, Kenneth

    2010-06-10

    Mechanisms that preserve endothelial cell (EC) integrity remain elusive, but are critical for new strategies directed against endocrine disorders such as diabetes mellitus (DM). Here we demonstrate in primary cerebral ECs with a clinically relevant model of elevated d-glucose that Akt1 and the post-translational modification and subcellular trafficking of the forkhead transcription factor FoxO3a are critical for early apoptotic membrane signaling and subsequent degradation of nuclear DNA. FoxO3a also directly governs apoptotic mitochondrial signal transduction pathways, since gene knockdown of FoxO3a prevents mitochondrial membrane depolarization as well as the release of cytochrome c. Control of this apoptotic cascade extends to the rapid and progressive activation of caspases. The presence of FoxO3a is necessary for cleaved (active) caspase 1 and 3 expression, since loss of FoxO3a abrogates the induction of caspase activity. Our work identifies Akt1, FoxO3a and closely aligned pathways as key therapeutic targets during impaired glucose tolerance and DM.

  13. Effects of Elevated CO2 Concentration on Photosynthesis and Respiration of Populus Deltodies

    NASA Technical Reports Server (NTRS)

    Anderson, Angela M.

    1998-01-01

    To determine how increased atmospheric CO2 will affect the physiology of cottonwood trees, cuttings of the cloned Populus deltodies [cottonwood] were grown in open-top chambers containing ambient or elevated CO2 concentration. The control treatment was maintained at ambient Biosphere 2 atmospheric CO2 (c. 450 +/- 50 micro l/l), and elevated CO2 treatment was maintained at approximately double ambient Biosphere 2 atmospheric CO2 (c. 1000 +/- 50 micro l/l). The effects of elevated CO2 on leaf photosynthesis, and stomatal conductance were measured. The cottonwoods exposed to CO2 enrichment showed no significant indication of photosynthetic down-regulation. There was no significant difference in the maximum assimilation rate between the treatment and the control (P less than 0.24). The CO2 enriched treatment showed a decreased stomatal conductance of 15% (P less than 0.03). The elevated CO2 concentrated atmosphere had an effect on the respiration rates of the plants; the compensation point of the treatment was on average 13% higher than the control (P less than 0.01).

  14. Different responses of invasive and native species to elevated CO 2 concentration

    NASA Astrophysics Data System (ADS)

    Song, Liying; Wu, Jinrong; Li, Changhan; Li, Furong; Peng, Shaolin; Chen, Baoming

    2009-01-01

    Increasing atmospheric CO 2 concentration is regarded as an important factor facilitating invasion. However, the mechanisms by which invasive plants spread at the expense of existing native plants are poorly understood. In this study, three invasive species ( Mikania micrantha, Wedelia trilobata and Ipomoea cairica) and their indigenous co-occurring species or congeners ( Paederia scandens, Wedelia chinensis and Ipomoea pescaprae) in South China were exposed to elevated CO 2 concentration (700 μmol mol -1). The invasive species showed an average increase of 67.1% in photosynthetic rate, significantly different from the native species (24.8%). On average the increase of total biomass at elevated CO 2 was greater for invasive species (70.3%) than for the natives (30.5%). Elevated CO 2 also resulted in significant changes in biomass allocation and morphology of invasive M. micrantha and W. trilobata. These results indicate a substantial variation in response to elevated CO 2 between these invasive and native plant species, which might be a potential mechanism partially explaining the success of invasion with ongoing increase in atmospheric CO 2.

  15. Effects of Elevated CO2 Concentration on Photosynthesis and Respiration of Populus Deltodies

    NASA Technical Reports Server (NTRS)

    Anderson, Angela M.

    1998-01-01

    To determine how increased atmospheric CO2 will affect the physiology of cottonwood trees, cuttings of the cloned Populus deltodies [cottonwood] were grown in open-top chambers containing ambient or elevated CO2 concentration. The control treatment was maintained at ambient Biosphere 2 atmospheric CO2 (c. 450 +/- 50 micro l/l), and elevated CO2 treatment was maintained at approximately double ambient Biosphere 2 atmospheric CO2 (c. 1000 +/- 50 micro l/l). The effects of elevated CO2 on leaf photosynthesis, and stomatal conductance were measured. The cottonwoods exposed to CO2 enrichment showed no significant indication of photosynthetic down-regulation. There was no significant difference in the maximum assimilation rate between the treatment and the control (P less than 0.24). The CO2 enriched treatment showed a decreased stomatal conductance of 15% (P less than 0.03). The elevated CO2 concentrated atmosphere had an effect on the respiration rates of the plants; the compensation point of the treatment was on average 13% higher than the control (P less than 0.01).

  16. The sex of the foetus affects maternal blood glucose concentrations in overweight and obese pregnant women.

    PubMed

    Seneviratne, Sumudu N; Derraik, José G B; Jiang, Yannan; McCowan, Lesley M E; Gusso, Silmara; Cutfield, Wayne S; Hofman, Paul L

    2016-12-26

    There is increasing evidence that the sex of the foetus may alter the maternal metabolic milieu during pregnancy. Following a randomized controlled trial of exercise in overweight and obese pregnant women, we assessed whether the sex of the foetus was associated with changes in maternal metabolism. Data were analysed on 74 randomized participants who completed the trial, including 38 mothers carrying males and 36 mothers carrying females. At 19 weeks of gestation, mothers carrying boys had higher blood glucose concentrations than those carrying girls (5.4 vs 4.9 mmol/l; p = .046). At 36 weeks of gestation, differences were more marked, with blood glucose concentrations 15% higher in mothers carrying females (5.7 vs 5.0 mmol/l; p = .004). In addition, mothers carrying girls had higher concentrations of hs-CRP across pregnancy (5.0 vs 3.6 mg/l; p = .029). Our findings provide further evidence that the sex of the foetus appears to influence maternal metabolism.

  17. Correction of glucose concentration interference on Jaffé kinetic creatinine assay in peritoneal dialysis.

    PubMed

    Da Rin, G; Amici, G; Virga, G; Bardin, C; Calzavara, P; Bocci, C

    1995-01-01

    Overestimation of creatinine measurement using the Jaffé kinetic method in peritoneal dialysis solutions, due to glucose interference, has been quantified and corrected through the elaboration of linear formulas obtained from 110 recovery and 301 biological tests. The added pure powdered creatinine and enzymatic method were considered as references after proven accuracy. Considering creatinine as well as glucose concentration interference, we obtained correction formulas from multiple regression application. All the computed formulas gave satisfactory corrections but different accuracy levels. The best model in biological samples was: Corrected CR = K1JafféCr + K2Glucose (all values in mg/dl) where K1 = 0.973 and K2 = -0.00035 (Rsq = 0.987, F ratio = 10,945, p = 0.00001). Applying formulas to biological samples there was a drop in accuracy, possibly explained by the presence of numerous unidentified substances in peritoneal dialysis biological samples that can amplify scatter. Every laboratory can reduce the error of the Jaffé kinetic assay by calculating their own correction formula in relation to the method and instrument used, because Jaffé kinetic assay gives different results with different kinetic windows. So, especially when applied to peritoneal dialysis fluid measurements, if a creatinine assay reference method is not available, the correction formula can be applied directly as given. Otherwise the method we have described can be followed with a well-structured creatinine recovery fest to identify and quantify assay interferences.

  18. Chickpeas suppress postprandial blood glucose concentration, and appetite and reduce energy intake at the next meal.

    PubMed

    Zafar, Tasleem A; Kabir, Yearul

    2017-03-01

    The current study was designed to explore the beneficial properties of chickpeas consumption on suppressing appetite, excessive blood glucose excursions, and energy intake (EI) from a subsequent meal. Two caloric preloaded foods, chickpeas, and white bread were compared to water control, fed to healthy female subjects at equal energy density, volume, and available carbohydrate content in two experiments spanning over 60 and 120 min. Blood glucose was measured by a portable glucometer and satiety by using a visual analogue scale questionnaire at baseline and every 15 up to 60 min in both experiments and then every 30 until 120 min in Experiment 2 after the preloads ingestion. A test meal was served at the end of both experiments to calculate EI and percent energy compensation (%EC). The results suggest a reduction of 29-36% in blood glucose concentration, and 83-98% EC after the chickpeas in Experiments 1 and 2 respectively compared to white bread. The average appetite showed a positive association with EI. We conclude that the consumption of chickpeas is beneficial on glycemic control and may help in body weight management through suppressing appetite and energy intake.

  19. Heterogeneity in multicell spheroids induced by alterations in the external oxygen and glucose concentration

    SciTech Connect

    Freyer, J.P.

    1981-01-01

    Multicell tumor spheroids are currently being used as in vitro models for investigations of tumor therapy, based on the concept that spheroids exhibit many of the growth characteristics and cell subpopulations of tumors in vivo. At present, the factors which regulate cell proliferation, clonogenicity and viability in spheroids are unknown, as are the effects of alterations in these critical factors on therapeutic results. The symmetrical structure of the EMT6/Ro spheroid and the ease of manipulating the external environment are key features of this spheroid system which are used to investigate the role of oxygen and glucose in the control of spheroid growth and the development of cell subpopulations. A technique is developed for selectivity dissociating a spheroid population into fractions of cells originating from known locations in the spheroid structure. Characterization of these cell subpopulations demonstrates that outer cells are similar to an exponential cell population, while inner region cells are not proliferating and have a reduced cell volume and clonogenic capacity. Oxygen and glucose concentrations at critical depths in the spheroid were determined. It is concluded that the oxygen and glucose supply to cells in spheroids is critical in determining the initial onset of central necrosis. 217 references, 32 figures, 15 tables. (ACR)

  20. Effects of long-term elevated glucose on collagen formation by mesangial cells.

    PubMed

    Baccora, M H A; Cortes, P; Hassett, C; Taube, D W; Yee, J

    2007-11-01

    Glomerulosclerosis is one of the complications of diabetes that occurs after many years of uncontrolled hyperglycemia. Mesangial cells (MCs) exposed to high glucose (HG) for short periods have shown that transforming growth factor-beta (TGF-beta) and activated diacylglycerol-dependent protein kinase C (PKC) mediate increased collagen formation. Our study examined collagen formation by MCs exposed to HG for 8 weeks. Exposure to HG in overnight culture resulted in the activation of all PKC isoforms. In contrast, 8-week exposure to HG resulted in the persistent activation of PKC-delta, did not change PKC-alpha or -beta activity, and decreased PKC-epsilon activity while increasing collagen I and IV gene and protein expression. Collagen IV accumulation was reversed by specific PKC-delta inhibition. Collagen IV gene expression was completely normalized by TGF-beta neutralization; however, this was associated with plasminogen activator inhibitor-1 (PAI-1) overexpression and a modest reduction in collagen protein. Our studies suggest that prolonged exposure to HG results in PKC-delta-driven collagen accumulation by MCs mediated by PAI-1 but independent of TGF-beta.

  1. Effects of pH and elevated glucose levels on the electrochemical behavior of dental implants.

    PubMed

    Tamam, Evsen; Turkyilmaz, Ilser

    2014-04-01

    Implant failure is more likely to occur in persons with medically compromising systemic conditions, such as diabetes related to high blood glucose levels and inflammatory diseases related to pH levels lower than those in healthy people. The aim of this study was to investigate the effects of lower pH level and simulated- hyperglycemia on implant corrosion as these effects are critical to biocompatibility and osseointegration. The electrochemical corrosion properties of titanium implants were studied in four different solutions: Ringer's physiological solution at pH = 7.0 and pH = 5.5 and Ringer's physiological solution containing 15 mM dextrose at pH = 7 and pH = 5.5. Corrosion behaviors of dental implants were determined by cyclic polarization test and electrochemical impedance spectroscopy. Surface alterations were studied using a scanning electron microscope. All test electrolytes led to apparent differences in corrosion behavior of the implants. The implants under conditions of test exhibited statistically significant increases in I(corr) from 0.2372 to 1.007 μAcm(-2), corrosion rates from 1.904 to 8.085 mpy, and a decrease in polarization resistances from 304 to 74 Ω. Implants in dextrose-containing solutions were more prone to corrosion than those in Ringer's solutions alone. Increasing the acidity also yielded greater corrosion rates for the dextrose-containing solutions and the solutions without dextrose.

  2. Rapid activation and nuclear translocation of mitogen-activated protein kinases in response to physiological concentration of glucose in the MIN6 pancreatic beta cell line.

    PubMed

    Benes, C; Roisin, M P; Van Tan, H; Creuzet, C; Miyazaki, J; Fagard, R

    1998-06-19

    MIN6 is one of the few pancreatic beta cell lines that respond to physiological concentrations of glucose by secreting insulin, and little is known about the triggered molecular mechanisms. We report below that the response to glucose in the MIN6 cells includes an activation of the p42 and p44 mitogen-activated protein (MAP) kinases (ERK2 and ERK1). This activation also occurred with the antidiabetic sulfonylurea glibenclamide and kainate, a specific agonist of a subtype of the ionotropic glutamate receptors, which depolarize the cytoplasmic membrane. The requirement for a calcium entry through the L-type voltage-gated channels and other characteristics of the regulation of the MAP kinase activity, such as the effect of the elevation of the cAMP concentration by forskolin, were similar to those of the secretion of insulin. However, the activation of the MAP kinases is not required for the secretion of insulin, inasmuch as this effect of glucose was not abolished when the MAP kinases were prevented from activation by PD098059, an inhibitor of the MAP kinase kinase. However, as the MAP kinases were translocated into the nucleus, they might be implicated in the calcium-dependent transcriptional response of the cells to glucose and thus regulate the expression of the insulin gene.

  3. Effect of trimethoprim-sulfamethoxazole on blood insulin and glucose concentrations of diabetics.

    PubMed Central

    Mihic, M.; Mautner, L. S.; Feness, J. Z.; Grant, K.

    1975-01-01

    Trimethoprim-sulfamethoxazole (TMP-SMX) caused no significant changes in the blood glucose or insulin concentrations of diabetic subjects treated by dietary measures alone or by insulin and diet. In only one of eight subjects receiving oral hypoglycemic agents for the control of diabetes did a significant immediate increase in immunoreactive insulin follow administration of TMP-SMX. In the same patient hypoglycemic symptoms were present after the agent had been taken for 14 days. Images FIG. 1 FIG. 2 FIG. 3 PMID:1137831

  4. Some biochemical and pathophysiological aspects of long-term elevation of brain ornithine concentrations.

    PubMed

    Daune-Anglard, G; Bonaventure, N; Seiler, N

    1993-07-01

    Mice and chicken were given 5-fluoromethylornithine (5FMOrn), a selective inactivator of ornithine aminotransferase (OAT) over extended periods of time. This treatment allowed us to maintain elevated concentrations of ornithine in all tissues. Since gyrate atrophy, an autosomal recessive human disease, is characterized by the absence of OAT, special emphasis was put on the study of the visual system. Ophthalmoscopic and histologic examinations of the eye as well as electroretinograms and locomotor behaviour demonstrated an unimpaired visual system and brain. No toxic effects were observable in the treated mice. Likewise, chick embryo development was normal in spite of highly elevated brain and tissue ornithine concentrations. A likely explanation for the absence of toxic effects of 5FMOrn treatment, disregarding the non-toxicity of ornithine, is the fact that 10-20% of tissue OAT is refractory to inactivation by 5FMOrn. This residual activity may be sufficient to maintain vital functions.

  5. Effects of profound acidemia on the dynamic glucose and insulin response and plasma potassium and phosphorus concentrations during an intravenous glucose tolerance test in neonatal calves.

    PubMed

    Trefz, F M; Lorenz, I; Constable, P D

    2017-09-06

    Acidemia and electrolyte imbalances such as hyperkalemia are common in neonatal calves with diarrhea. Acidemia negatively affects the cellular response to insulin and may therefore result in deranged glucose, potassium, and phosphorus homeostasis. The primary aim of this study was to compare indices that characterize the dynamic glucose and insulin response between acidemic and nonacidemic neonatal diarrheic calves and a healthy control group during an intravenous glucose tolerance test (IVGTT) that consisted of i.v. administration of 0.3 g of glucose per kg of body weight. Secondary aims were to characterize the associated changes in plasma potassium and phosphorus concentrations. The effect of correction of profound acidemia with a sodium bicarbonate containing infusion on these parameters was also assessed. Thirty calves (age ≤21 d) were purposively assigned to one of the following groups: 10 calves with diarrhea and profound acidemia (venous blood pH <7.20) where an IVGTT was performed before and after treatment with sodium bicarbonate, 10 calves with diarrhea and minimal acid-base disturbance (venous blood pH >7.35), and 10 healthy control calves. Profoundly acidemic diarrheic calves (jugular venous blood pH 6.99 ± 0.10) had a similar initial increase in plasma insulin concentration to that in healthy control calves or nonacidemic calves with diarrhea. However, insulin concentrations remained relatively stable in acidemic calves between 15 and 60 min after the start of the IVGTT, whereas a marked decrease in plasma insulin concentrations occurred in all other groups during the same period of time. We conclude that acidemia does not alter cell glucose availability or the dynamic response of glucose, phosphorus, and potassium to insulin; however, acidemia markedly prolongs plasma insulin concentrations following an IVGTT through an unidentified mechanism. Results of this study emphasize the importance of correcting acidemia and metabolic acidosis in neonatal

  6. Acute postexercise effects of concentric and eccentric exercise on glucose tolerance.

    PubMed

    Cook, Matthew David; Myers, Stephen David; Kelly, John Stephen Michael; Willems, Mark Elisabeth Theodorus

    2015-02-01

    Impaired glucose tolerance was shown to be present 48 hr following muscle-damaging eccentric exercise. We examined the acute effect of concentric and muscle-damaging eccentric exercise, matched for intensity, on the responses to a 2-hr 75-g oral glucose tolerance test (OGTT). Ten men (27 ± 9 years, 178 ± 7 cm, 75 ± 11 kg, VO₂max: 52.3 ± 7.3 ml · kg⁻¹ · min⁻¹) underwent three OGTTs after an overnight 12 hr fast: rest (control), 40-min (5 × 8-min with 2-min interbout rest) of concentric (level running, 0%, CON) or eccentric exercise (downhill running, -12%, ECC). Running intensity was matched at 60% of maximal metabolic equivalent. Maximal isometric force of m. quadriceps femoris of both legs was measured before and after the running protocols. Downhill running speed was higher (level: 9.7 ± 2.1, downhill: 13.8 ± 3.2 km · hr⁻¹, p < .01). Running protocols had similar VO₂max (p = .59), heart rates (p = .20) and respiratory exchange ratio values (p = .74) indicating matched intensity and metabolic demands. Downhill running resulted in higher isometric force deficits (level: 3.0 ± 6.7, downhill: 17.1 ± 7.3%, p < .01). During OGTTs, area-under-the-curve for plasma glucose (control: 724 ± 97, CON: 710 ± 77, ECC: 726 ± 72 mmol · L⁻¹ · 120 min, p = .86) and insulin (control: 24995 ± 11229, CON: 23319 ± 10417, ECC: 21842 ± 10171 pmol · L⁻¹ · 120 min, p = .48), peak glucose (control: 8.1 ± 1.3, CON: 7.7 ± 1.2, ECC: 7.7 ± 1.1 mmol · L⁻¹, p = .63) and peak insulin levels (control: 361 ± 188, CON: 322 ± 179, ECC: 299 ± 152 pmol · L⁻¹, p = .30) were similar. It was concluded that glucose tolerance and the insulin response to an OGTT were not changed immediately by muscle-damaging eccentric exercise.

  7. Effects of glucose concentration on in vitro fertilization in BALB/c mice.

    PubMed

    Wu, H T; Chou, C K; Lin, C S; Huang, M C

    2003-12-01

    BALB/c mice are widely used in genetic, tumour and immunological studies. However, the mice demonstrate a lower reproduction rate, low fertility and small litters, because of their highly genetic homozygoisty. Based on in vitro fertilization (IVF), a routine technique for biomedical studies, it is worth to evaluate the effects to BALB/c mice on IVF efficiency. In order to test the genetic factor affecting the IVF efficiency of BALB/c, four reciprocal IVF tests of BALB/cByJ and FVB/NCrl mice were performed. The results showed that the average fertility of IVF sponsored by FVB/NCrl spermatozoa was 69.6%, but only 12.1% was obtained from BALB/cByJ strain. Effect of glucose contained in the culture medium to the IVF efficiency of BALB/cByJ was also evaluated. The results showed that the fertility of BALB/cByJ spermatozoa incubated with 0, 2.7, 5.5, 11.1 and 22.2 mm of glucose in the TYH medium were 6.8, 9.9, 13.9, 32.7 and 22.2%, respectively. It is showed that IVF efficiency of BALB/cByJ spermatozoa could be improved depending on the concentration of glucose in the IVF medium. According to the results, it is beleived that lower IVF of BALB/cByJ mice might be due to the genetic defect in spermatozoa and increasing glucose in the IVF medium which significantly affect the IVF efficiency of BALB/cByl via activating the spermatozoa.

  8. Increased soil salinity causes elevated cadmium concentrations in field-grown potato tubers

    SciTech Connect

    McLaughlin, M.J.; Tiller, K.G.; Beech, T.A.

    1994-09-01

    Elevated Cd concentrations have been observed in potato (Solanum tuberosum L.) tubers from commercial crops in certain regions of southern Australia. Reasons for enhanced Cd uptake by tubers were investigated by a survey of commercial crops and associated soils. Eighty-nine sites were selected and paired tuber and soil samples taken. Concentration of Cd in tubers was compared to potato variety, tuber elemental composition, and chemical-physical characteristics of topsoil (0-150) and subsoil (150-300 mm). Tuber Cd concentrations were positively related to soil electrical conductivity (EC) and extractable Cl (R{sup 2} = 0.62, P < 0.001) in the topsoil, with extractable Cl accounting for more variation than EC. Tuber Cd concentrations were not strongly related (R{sup 2} = 0.23, P < 0.05) to potato variety alone. However, inclusion of variety and EDTA-extractable Zn with water-extractable Cl in a multivariate model resulted in a small but significant improvement in the variance accounted for by the model (R{sup 2} = 0.73, p < 0.001). Tuber Cd was unrelated to tuber concentrations of P or tuber but was positively related to concentrations of major cations in the tuber particularly Na. Soil pH, total C, EDTA-extractable Cd, or particle-size distribution were not correlated to tuber Cd concentrations, either singly or after inclusion in a multivariate model with soil Cl concentrations. As Cl is known to mobilize soil Cd and increase its phytoavailability, elevated Cd concentrations in potato tubers in southern Australia appear to be largely a result of the use of saline irrigation waters. 41 refs., 5 figs., 4 tabs.

  9. Distribution of Elevated Nitrate Concentrations in Ground Water in Washington State

    USGS Publications Warehouse

    Frans, Lonna

    2008-01-01

    More than 60 percent of the population of Washington State uses ground water for their drinking and cooking needs. Nitrate concentrations in ground water are elevated in parts of the State as a result of various land-use practices, including fertilizer application, dairy operations and ranching, and septic-system use. Shallow wells generally are more vulnerable to nitrate contamination than deeper wells (Williamson and others, 1998; Ebbert and others, 2000). In order to protect public health, the Washington State Department of Health requires that public water systems regularly measure nitrate in their wells. Public water systems serving more than 25 people collect water samples at least annually; systems serving from 2 to 14 people collect water samples at least every 3 years. Private well owners serving one residence may be required to sample when the well is first drilled, but are unregulated after that. As a result, limited information is available to citizens and public health officials about potential exposure to elevated nitrate concentrations for people whose primary drinking-water sources are private wells. The U.S. Geological Survey and Washington State Department of Health collaborated to examine water-quality data from public water systems and develop models that calculate the probability of detecting elevated nitrate concentrations in ground water. Maps were then developed to estimate ground water vulnerability to nitrate in areas where limited data are available.

  10. Factors controlling elevated lead concentrations in water samples from aquifer systems in Florida

    SciTech Connect

    Katz, B.G.; Berndt, M.P.; Bullen, T.D.; Hansard, P.

    1999-07-01

    This report presents results of detailed statistical analyses of total and dissolved Pb concentrations in water samples collected from the major aquifer systems in Florida for the FGWQMN [Florida Ground Water Quality Monitoring Network] to determine the influence of anthropogenic factors on elevated Pb concentrations. In addition, Pb isotopic data are presented for water samples collected from a subset of 13 wells in the monitoring network, samples of aquifer material, rainfall, and Pb counterweights. The Pb-isotope data provide a better understanding of the relative contributions of anthropogenic and natural sources of Pb in ground water samples from Florida`s major aquifer systems.

  11. Elevated blood lead concentrations and vitamin D deficiency in winter and summer in young urban children.

    PubMed

    Kemp, Francis W; Neti, Prasad V S V; Howell, Roger W; Wenger, Peter; Louria, Donald B; Bogden, John D

    2007-04-01

    It is widely recognized that blood lead concentrations are higher in the summer than in winter. Although the effects of some environmental factors such as lead in dust on this phenomenon have been studied, relationships to sunlight-induced vitamin D synthesis have not been adequately investigated. Vitamin D status is influenced by the diet, sunlight exposure, age, skin pigmentation, and other factors, and may modify gastrointestinal lead absorption or release of lead stored in bones into the bloodstream. We collected paired blood samples from 142 young, urban African-American and Hispanic children in the winter and summer to study the seasonal increase in blood lead and its relationships to vitamin D nutrition, age, and race. A winter/summer (W/S) increase in blood lead concentrations of 32.4% was found for children 1-3 years of age. There was a smaller W/S increase of 13.0% in children 4-8 years of age. None of the 51 Hispanic children had an elevated blood lead concentration (> or = 10 microg/dL) during the winter, and only one had an elevated summertime concentration. In contrast, elevated blood lead concentrations were frequent in the 91 African-American children, especially those 1-3 years of age. For the latter, the percentage with elevated blood lead levels increased from 12.2% in winter to 22.5% in summer. A 1.2% W/S increase in serum 25-hydroxy-vitamin D (serum 25-OH-D) concentrations was found for children 1-3 years of age. However, in children 4-8 years of age the W/S increase in serum 25-OH-D was much larger-33.6%. The percentages of children with low (< 16 microg/L) serum 25-OH-D concentrations were 12.0% in winter and 0.7% in summer and were consistently greater in African-American than in Hispanic children. The seasonal increases in blood lead and serum 25-OH-D in children 4-8 years of age were significantly associated. The higher summertime serum 25-OH-D concentrations for the 4- to 8-year-old children are likely caused by increased sunlight

  12. Elevated glucose and oligomeric β-amyloid disrupt synapses via a common pathway of aberrant protein S-nitrosylation

    PubMed Central

    Akhtar, Mohd Waseem; Sanz-Blasco, Sara; Dolatabadi, Nima; Parker, James; Chon, Kevin; Lee, Michelle S.; Soussou, Walid; McKercher, Scott R.; Ambasudhan, Rajesh; Nakamura, Tomohiro; Lipton, Stuart A.

    2016-01-01

    Metabolic syndrome (MetS) and Type 2 diabetes mellitus (T2DM) increase risk for Alzheimer's disease (AD). The molecular mechanism for this association remains poorly defined. Here we report in human and rodent tissues that elevated glucose, as found in MetS/T2DM, and oligomeric β-amyloid (Aβ) peptide, thought to be a key mediator of AD, coordinately increase neuronal Ca2+ and nitric oxide (NO) in an NMDA receptor-dependent manner. The increase in NO results in S-nitrosylation of insulin-degrading enzyme (IDE) and dynamin-related protein 1 (Drp1), thus inhibiting insulin and Aβ catabolism as well as hyperactivating mitochondrial fission machinery. Consequent elevation in Aβ levels and compromise in mitochondrial bioenergetics result in dysfunctional synaptic plasticity and synapse loss in cortical and hippocampal neurons. The NMDA receptor antagonist memantine attenuates these effects. Our studies show that redox-mediated posttranslational modification of brain proteins link Aβ and hyperglycaemia to cognitive dysfunction in MetS/T2DM and AD. PMID:26743041

  13. Impact of admission blood glucose levels on prognosis of elderly patients with ST elevation myocardial infarction treated by primary percutaneous coronary intervention.

    PubMed

    Ekmekci, Ahmet; Uluganyan, Mahmut; Tufan, Fatif; Uyarel, Huseyin; Karaca, Gurkan; Kul, Seref; Gungor, Barış; Ertas, Gokhan; Erer, Betul; Sayar, Nurten; Gul, Mehmet; Eren, Mehmet

    2013-12-01

    Admission hyperglycemia in acute myocardial infarction (MI) is related with increased in-hospital and long term mortality and major cardiac adverse events. We aimed to investigate how admission hyperglycemia affects the short and long term outcomes in elderly patients (> 65 years) after primary percutaneous coronary intervention for ST elevation myocardial infarction. We retrospectively analyzed 677 consecutive elderly patients (mean age 72.2 ± 5.4). Patients were divided into two groups according to admission blood glucose levels. Group 1: low glucose group (LLG), glucose < 168 mg/dL; and Group 2: high glucose group (HGG), glucose > 168 mg/dL. In-hospital, long term mortality and in-hospital major adverse cardiac events were higher in the high admission blood glucose group (P < 0.001). Multivariate regression analysis showed: Killip > 1, post-thrombolysis in MI < 3 and admission blood glucose levels were independent predictors of in-hospital adverse cardiac events (P < 0.001). Admission hyperglycemia in elderly patients presented with ST elevation myocardial infarction is an independent predictor of in-hospital major adverse cardiac events and is associated with in-hospital and long term mortality.

  14. Impact of admission blood glucose levels on prognosis of elderly patients with ST elevation myocardial infarction treated by primary percutaneous coronary intervention

    PubMed Central

    Ekmekci, Ahmet; Uluganyan, Mahmut; Tufan, Fatif; Uyarel, Huseyin; Karaca, Gurkan; Kul, Seref; Gungor, Barış; Ertas, Gokhan; Erer, Betul; Sayar, Nurten; Gul, Mehmet; Eren, Mehmet

    2013-01-01

    Objective Admission hyperglycemia in acute myocardial infarction (MI) is related with increased in-hospital and long term mortality and major cardiac adverse events. We aimed to investigate how admission hyperglycemia affects the short and long term outcomes in elderly patients (> 65 years) after primary percutaneous coronary intervention for ST elevation myocardial infarction. Methods We retrospectively analyzed 677 consecutive elderly patients (mean age 72.2 ± 5.4). Patients were divided into two groups according to admission blood glucose levels. Group 1: low glucose group (LLG), glucose < 168 mg/dL; and Group 2: high glucose group (HGG), glucose > 168 mg/dL. Results In-hospital, long term mortality and in-hospital major adverse cardiac events were higher in the high admission blood glucose group (P < 0.001). Multivariate regression analysis showed: Killip > 1, post-thrombolysis in MI < 3 and admission blood glucose levels were independent predictors of in-hospital adverse cardiac events (P < 0.001). Conclusions Admission hyperglycemia in elderly patients presented with ST elevation myocardial infarction is an independent predictor of in-hospital major adverse cardiac events and is associated with in-hospital and long term mortality. PMID:24454322

  15. Responses of Legume Versus Nonlegume Tropical Tree Seedlings to Elevated CO2 Concentration1[OA

    PubMed Central

    Cernusak, Lucas A.; Winter, Klaus; Martínez, Carlos; Correa, Edwin; Aranda, Jorge; Garcia, Milton; Jaramillo, Carlos; Turner, Benjamin L.

    2011-01-01

    We investigated responses of growth, leaf gas exchange, carbon-isotope discrimination, and whole-plant water-use efficiency (WP) to elevated CO2 concentration ([CO2]) in seedlings of five leguminous and five nonleguminous tropical tree species. Plants were grown at CO2 partial pressures of 40 and 70 Pa. As a group, legumes did not differ from nonlegumes in growth response to elevated [CO2]. The mean ratio of final plant dry mass at elevated to ambient [CO2] (ME/MA) was 1.32 and 1.24 for legumes and nonlegumes, respectively. However, there was large variation in ME/MA among legume species (0.92–2.35), whereas nonlegumes varied much less (1.21–1.29). Variation among legume species in ME/MA was closely correlated with their capacity for nodule formation, as expressed by nodule mass ratio, the dry mass of nodules for a given plant dry mass. WP increased markedly in response to elevated [CO2] in all species. The ratio of intercellular to ambient CO2 partial pressures during photosynthesis remained approximately constant at ambient and elevated [CO2], as did carbon isotope discrimination, suggesting that WP should increase proportionally for a given increase in atmospheric [CO2]. These results suggest that tree legumes with a strong capacity for nodule formation could have a competitive advantage in tropical forests as atmospheric [CO2] rises and that the water-use efficiency of tropical tree species will increase under elevated [CO2]. PMID:21788363

  16. Responses of legume versus nonlegume tropical tree seedlings to elevated CO2 concentration.

    PubMed

    Cernusak, Lucas A; Winter, Klaus; Martínez, Carlos; Correa, Edwin; Aranda, Jorge; Garcia, Milton; Jaramillo, Carlos; Turner, Benjamin L

    2011-09-01

    We investigated responses of growth, leaf gas exchange, carbon-isotope discrimination, and whole-plant water-use efficiency (W(P)) to elevated CO(2) concentration ([CO(2)]) in seedlings of five leguminous and five nonleguminous tropical tree species. Plants were grown at CO(2) partial pressures of 40 and 70 Pa. As a group, legumes did not differ from nonlegumes in growth response to elevated [CO(2)]. The mean ratio of final plant dry mass at elevated to ambient [CO(2)] (M(E)/M(A)) was 1.32 and 1.24 for legumes and nonlegumes, respectively. However, there was large variation in M(E)/M(A) among legume species (0.92-2.35), whereas nonlegumes varied much less (1.21-1.29). Variation among legume species in M(E)/M(A) was closely correlated with their capacity for nodule formation, as expressed by nodule mass ratio, the dry mass of nodules for a given plant dry mass. W(P) increased markedly in response to elevated [CO(2)] in all species. The ratio of intercellular to ambient CO(2) partial pressures during photosynthesis remained approximately constant at ambient and elevated [CO(2)], as did carbon isotope discrimination, suggesting that W(P) should increase proportionally for a given increase in atmospheric [CO(2)]. These results suggest that tree legumes with a strong capacity for nodule formation could have a competitive advantage in tropical forests as atmospheric [CO(2)] rises and that the water-use efficiency of tropical tree species will increase under elevated [CO(2)].

  17. Geochemical controls of elevated arsenic concentrations in groundwater, Ester Dome, Fairbanks district, Alaska

    USGS Publications Warehouse

    Verplanck, P.L.; Mueller, S.H.; Goldfarb, R.J.; Nordstrom, D.K.; Youcha, E.K.

    2008-01-01

    Ester Dome, an upland area near Fairbanks, Alaska, was chosen for a detailed hydrogeochemical study because of the previously reported elevated arsenic in groundwater, and the presence of a large set of wells amenable to detailed sampling. Ester Dome lies within the Fairbanks mining district, where gold-bearing quartz veins, typically containing 2-3??vol.% sulfide minerals (arsenopyrite, stibnite, and pyrite), have been mined both underground and in open cuts. Gold-bearing veins on Ester Dome occur in shear zones and the sulfide minerals in these veins have been crushed to fine-grained material by syn- or post-mineralization movement. Groundwater at Ester Dome is circumneutral, Ca-HCO3 to Ca-SO4 type, and ranges from dilute (specific conductance of 48????S/cm) to more concentrated (specific conductance as high as 2070????S/cm). In general, solute concentrations increase down hydrologic gradient. Redox species indicate that the groundwaters range from oxic to sub-oxic (low dissolved oxygen, Fe(III) reduction, no SO4 reduction). Waters with the highest Fe concentrations, as high as 10.7??mg/L, are the most anoxic. Dissolved As concentrations range from < 1 to 1160????g/L, with a median value of 146????g/L. Arsenic concentrations are not correlated with specific conductance or Fe concentrations, suggesting that neither groundwater residence time, nor reductive dissolution of iron oxyhydroxides, control the arsenic chemistry. Furthermore, As concentrations do not covary with other constituents that form anions and oxyanions in solution (e.g., HCO3, Mo, F, or U) such that desorption of arsenic from clays or oxides also does not control arsenic mobility. Oxidation of arsenopyrite and dissolution of scorodite, in the near-surface environment appears to be the primary control of dissolved As in this upland area. More specifically, the elevated As concentrations are spatially associated with sulfidized shear zones and localities of gold-bearing quartz veins. Consistent with

  18. Elevated Atmospheric Carbon Dioxide Concentrations Amplify Alternaria alternata Sporulation and Total Antigen Production

    PubMed Central

    Wolf, Julie; O’Neill, Nichole R.; Rogers, Christine A.; Muilenberg, Michael L.; Ziska, Lewis H.

    2010-01-01

    Background Although the effect of elevated carbon dioxide (CO2) concentration on pollen production has been established in some plant species, impacts on fungal sporulation and antigen production have not been elucidated. Objective Our purpose was to examine the effects of rising atmospheric CO2 concentrations on the quantity and quality of fungal spores produced on timothy (Phleum pratense) leaves. Methods Timothy plants were grown at four CO2 concentrations (300, 400, 500, and 600 μmol/mol). Leaves were used as growth substrate for Alternaria alternata and Cladosporium phlei. The spore abundance produced by both fungi, as well as the size (microscopy) and antigenic protein content (ELISA) of A. alternata, were quantified. Results Leaf carbon-to-nitrogen ratio was greater at 500 and 600 μmol/mol, and leaf biomass was greater at 600 μmol/mol than at the lower CO2 concentrations. Leaf carbon-to-nitrogen ratio was positively correlated with A. alternata spore production per gram of leaf but negatively correlated with antigenic protein content per spore. At 500 and 600 μmol/mol CO2 concentrations, A. alternata produced nearly three times the number of spores and more than twice the total antigenic protein per plant than at lower concentrations. C. phlei spore production was positively correlated with leaf carbon-to-nitrogen ratio, but overall spore production was much lower than in A. alternata, and total per-plant production did not vary among CO2 concentrations. Conclusions Elevated CO2 concentrations often increase plant leaf biomass and carbon-to-nitrogen ratio. Here we demonstrate for the first time that these leaf changes are associated with increased spore production by A. alternata, a ubiquitous allergenic fungus. This response may contribute to the increasing prevalence of allergies and asthma. PMID:20462828

  19. Infiltrated photonic crystal cavity as a highly sensitive platform for glucose concentration detection

    NASA Astrophysics Data System (ADS)

    Arafa, Safia; Bouchemat, Mohamed; Bouchemat, Touraya; Benmerkhi, Ahlem; Hocini, Abdesselam

    2017-02-01

    A Bio-sensing platform based on an infiltrated photonic crystal ring shaped holes cavity-coupled waveguide system is proposed for glucose concentration detection. Considering silicon-on-insulator (SOI) technology, it has been demonstrated that the ring shaped holes configuration provides an excellent optical confinement within the cavity region, which further enhances the light-matter interactions at the precise location of the analyte medium. Thus, the sensitivity and the quality factor (Q) can be significantly improved. The transmission characteristics of light in the biosensor under different refractive indices that correspond to the change in the analyte glucose concentration are analyzed by performing finite-difference time-domain (FDTD) simulations. Accordingly, an improved sensitivity of 462 nm/RIU and a Q factor as high as 1.11х105 have been achieved, resulting in a detection limit of 3.03х10-6 RIU. Such combination of attributes makes the designed structure a promising element for performing label-free biosensing in medical diagnosis and environmental monitoring.

  20. Elevated concentrations of trace elements in soil do not necessarily reflect metals available to plants.

    PubMed

    Antonious, George F; Silitonga, Maifan R; Tsegaye, Teferi D; Unrine, Jason M; Coolong, Timothy; Snyder, John C

    2013-01-01

    Bioaccumulation and entry of trace elements from soil into the food chain have made trace-elements major environmental pollutants. The main objective of this investigation was to study the impact of mixing native agricultural soil with municipal sewage sludge (SS) or SS mixed with yard waste (SS+YW) compost on total concentration of trace elements in soil, metals available to plants, and mobility of metals from soil into peppers and melon fruits. Regardless of soil treatment, the average concentrations of Ni, Cd, Pb, Cr, Cu, Zn, and Mo in melon fruits were 5.2, 0.7, 3.9, 0.9, 34.3, 96.1, and 3.5μg g(-1), respectively. Overall concentrations of Ni, Cd, Pb, and Zn in melon fruits were significantly greater (P < 0.05) than pepper fruits. No significant differences were found in Cr, Cu, and Mo concentrations between pepper and melon fruits at harvest time. Total metal concentrations and metal ions in soil available to melon and pepper plants were also determined. Total concentration of each metal in the soil was significantly greater than concentration of metal ions available to plants. Elevated Ni and Mo bioaccumulation factor (BAF > 1) of melon fruits of plants grown in SS+YW mixed soil is a characteristic that would be less favorable when plants grown on sites having high concentrations of these metals.

  1. The concentration of cyclic AMP and the activity of cyclic AMP dependent protein kinase and an inhibitor in the adipose tissue of rats fed lard or glucose diets.

    PubMed

    Jackowski, M M; Tepperman, H M; Tepperman, J

    1978-08-01

    Measurements of tissue cyclic AMP (cAMP) concentration, the activity of cAMP-dependent protein kinase and the level of the enzyme's thermostable, macromolecular inhibitor were made on preparations of rat epididymal fat pad from animals fed high fat or high carbohydrate diets. The cAMP concentration from rats adapted to a high lard diet for 14-15 days was 153 +/- 17.8 pmoles/mg protein as opposed to 76 +/- 6.0 found with high glucose diet. No significant difference in total cAMP-dependent protein kinase activity was observed among rats fed high glucose, high lard or laboratory chow, although the enzyme's activity ratio (-cAMP)(+cAMP) was significantly elevated with lard feeding (0.49 +/- 0.02) as opposed to glucose feeding (0.43 +/- 0.01). Crude preparations from lard and glucose fed animals were equivalent in inhibitory activity when tested with enzyme from chow fed animals. Agarose column chromatography separated holoenzyme and C subunit forms of the protein kinase when 500 mM NaCl was present in the elution buffer. Absence of the salt allowed subunit reassociation to occur. Direct addition of NaCl greater than or equal to 75 mM significantly inhibited protein kinase activity. The results indicate that the adipose tissue of rats fed a high lard diet has a higher concentration of cAMP and an increased protein kinase activity ratio than tissue from rats fed a fat free, high glucose diet. Total cAMP-dependent protein kinase activity and the level of a thermostable macromolecular inhibitor remained unchanged.

  2. Phytochemical changes in leaves of subtropical grasses and fynbos shrubs at elevated atmospheric CO 2 concentrations

    NASA Astrophysics Data System (ADS)

    Hattas, D.; Stock, W. D.; Mabusela, W. T.; Green, I. R.

    2005-07-01

    The effects of elevated atmospheric CO 2 concentrations on plant polyphenolic, tannin, nitrogen, phosphorus and total nonstructural carbohydrate concentrations were investigated in leaves of subtropical grass and fynbos shrub species. The hypothesis tested was that carbon-based secondary compounds would increase when carbon gain is in excess of growth requirements. This premise was tested in two ecosystems involving plants with different photosynthetic mechanisms and growth strategies. The first ecosystem comprised grasses from a C 4-dominated, subtropical grassland, where three plots were subjected to three different free air CO 2 enrichment treatments, i.e., elevated (600 to 800 μmol mol -1), intermediate (400 μmol mol -1) and ambient atmospheric CO 2. One of the seven grass species, Alloteropsis semialata, had a C 3 photosynthetic pathway while the other grasses were all C 4. The second ecosystem was simulated in a microcosm experiment where three fynbos species were grown in open-top chambers at ambient and 700 μmol mol -1 atmospheric CO 2 in low nutrient acid sands typical of south western coastal and mountain fynbos ecosystems. Results showed that polyphenolics and tannins did not increase in the grass species under elevated CO 2 and only in Leucadendron laureolum among the fynbos species. Similarly, foliar nitrogen content of grasses was largely unaffected by elevated CO 2, and among the fynbos species, only L. laureolum and Leucadendron xanthoconus showed changes in foliar nitrogen content under elevated CO 2, but these were of different magnitude. The overall decrease in nitrogen and phosphorus and consequent increase in C:N and C:P ratio in both ecosystems, along with the increase in polyphenolics and tannins in L. laureolum in the fynbos ecosystem, may negatively affect forage quality and decomposition rates. It is concluded that fast growing grasses do not experience sink limitation and invest extra carbon into growth rather than polyphenolics and

  3. [Effects of elevated ozone concentration on CO2 emission from soil-winter wheat system].

    PubMed

    Hu, Zheng-Hua; Li, Cen-Zi; Chen, Shu-Tao; Li, Han-Mao; Yang, Yan-Ping; Shen, Shuang-He

    2011-01-01

    To investigate the impact of elevated ozone (O3) on CO2 emission from soil-winter wheat system, outdoor experiments with simulating elevated O3 concentration were conducted, and static dark chamber-gas chromatograph method was used to measure CO2 emission fluxes. Results indicated that the elevated O3 did not change the seasonal pattern of CO2 emissions from soil-winter wheat system, but significantly decreased CO2 emission fluxes during turning-green stage and elongation-pregnant stage. From heading to maturity, CO2 emission fluxes were not found to be significant difference under 100 nL x L(-1) O3 treatment compared with the control, while 150 nL x L(-1) O3 treatment significantly declined CO2 emission fluxes. Significant relationships were found between respiration rate and air temperature under the control, 100 nL x L(-1) and 150 nL x L(-1) O3 treatment, and the fitting equation determined coefficients R2 were 0.139, 0.513 and 0.211, respectively. In addition, the Q10 (temperature sensitivity coefficients) for soil-winter wheat system's respiration were 1.13, 1.58 and 1.21, respectively. The results of this study suggested that elevated O3 could reduce CO2 emissions from agroecosystem.

  4. Elevated soil lead concentrations in residential yards in Appleton, WI, a small Midwestern city

    NASA Astrophysics Data System (ADS)

    Clark, J. J.; Knudsen, A. C.

    2010-12-01

    Elevated soil lead concentrations are well documented in large urban areas, having been attributed to a combination of leaded-paint, leaded-gasoline, and industrial emissions. Fewer studies, however, have been conducted in smaller communities. We analyzed 200 surface soils in the neighborhood near Lawrence University’s campus in Appleton, WI (population ~70,000). Like many larger cities Appleton has a historic city-center. However, it is has no high-density housing or commercial districts and has not seen heavy traffic. The socioeconomic pressures that lead to disrepair of inner city neighborhoods have been less prevalent here as well. At each property 3 integrated samples were taken, one adjacent to the front of the house, one in the front lawn, and one between the road and sidewalk. We correlated building and property traits (e.g. structure age, distance from road, exterior type, exterior condition, direction of exposure, and assessed home value) with soil lead concentrations determined by XRF and subsequently, mapped these data for geospatial patterns. Soil lead concentrations in the city park and campus greens were typically less than 100 ppm. The highest lead concentrations are close to campus, which has a number of civil war era buildings and homes. High lead concentrations (averaging over 1,000 ppm near the home, with concentrations as high as 10,000 ppm) were associated with aging, poorly maintained structures as expected. However, a number of well-maintained structures also show substantially elevated concentrations. These soil lead concentrations are not dissimilar to those found in much larger cities such as New Orleans, Milwaukee, and Chicago. Lead levels dropped quickly as distance from the house increased suggesting that the contamination is from lead paint and not from gasoline exhaust. Furthermore, samples taken adjacent to the main arterial through town exhibited relatively low, but slightly elevated lead levels (~250 ppm). Not surprisingly

  5. Glucose tolerance, blood lipid, insulin and glucagon concentration after single or continuous administration of aspartame in diabetics.

    PubMed

    Okuno, G; Kawakami, F; Tako, H; Kashihara, T; Shibamoto, S; Yamazaki, T; Yamamoto, K; Saeki, M

    1986-04-01

    A nutritive sweetener, aspartame (L-aspartyl-L-phenylalanine methylester) was administered orally to normal controls and diabetic patients in order to evaluate effects on blood glucose, lipids and pancreatic hormone secretion. An oral glucose tolerance test was also performed in the same subjects as a control study of aspartame administration. In 7 normal controls and 22 untreated diabetics, a single dose of 500 mg aspartame, equivalent to 100 g glucose in sweetness, induced no increase in blood glucose concentration. Rather, a small but significant decrease in blood glucose was noticed 2 or 3 h after administration. The decrease in blood glucose was found to be smallest in the control and became greater as the diabetes increased in severity. No significant change in blood insulin or glucagon concentration during a 3-h period was observed in either the controls or the diabetics. The second study was designed to determine the effects of 2 weeks' continuous administration of 125 mg aspartame, equal in sweetness to the mean daily consumption of sugar (20-30 g) in Japan, to 9 hospitalized diabetics with steady-state glycemic control. The glucose tolerance showed no significant change after 2 weeks' administration. Fasting, 1 h and 2 h postprandial blood glucose, blood cholesterol, triglyceride and HDL-cholesterol were also unaffected. From these and other published results, aspartame would seem to be a useful alternative nutrient sweetener for patients with diabetes mellitus.

  6. Determination of glucose concentration in a scattering medium based on selected wavelengths by use of an overtone absorption band.

    PubMed

    Yoon, Gilwon; Amerov, Airat K; Jeon, Kye Jin; Kim, Yoen-Joo

    2002-03-01

    A method and device for measuring glucose concentration in a scattering medium have been developed. A spectral range of 800-1800 nm is considered for wavelength selection because of its deeper penetration into biological tissue and the presence of a glucose absorption band. An algorithm based on selected wavelengths is proposed to minimize interference from other components. The optimal distance between the light source and the detector for diffuse reflectance measurement minimizes the influence of medium scattering. The proposed algorithm and measuring device are tested with a solution containing milk with added glucose. Glucose concentrations between 0 and 2000 mg/dl are determined with a correlation coefficient of 0.977. We also investigate the influence of concentration variations of other substances such as water, hemoglobin, albumin, and cholesterol when they are mixed in a scattering medium.

  7. Capillary blood sampling from the ear of dogs and cats and use of portable meters to measure glucose concentration.

    PubMed

    Wess, G; Reusch, C

    2000-02-01

    Two new methods for collection of capillary blood from the ear of dogs and cats for the measurement of blood glucose concentration using portable blood glucose meters (PBGMs) are described. The first method uses a lancing device after pre-warming the ear, while the second employs a vacuum lancing device. Both methods generated blood drops of adequate size, although the latter method was faster and easier to perform. Accuracy of the two PBGMs was evaluated clinically and statistically. Although assessment of statistical accuracy revealed differences between the PBGMs and the reference method, all of the PBGM readings were within clinically acceptable ranges. Measurement of capillary blood glucose concentration is easy to perform, inexpensive and fast. It may be used by owners to determine blood glucose concentrations at home, and could serve as a new tool for monitoring diabetic dogs and cats.

  8. Factors associated with elevated blood lead concentrations in children in Karachi, Pakistan.

    PubMed Central

    Rahbar, Mohammad Hossein; White, Franklin; Agboatwalla, Mubina; Hozhabri, Siroos; Luby, Stephen

    2002-01-01

    OBJECTIVES: To confirm whether blood lead concentrations in Karachi were as high as reported in 1989 and to identify which types of exposure to lead contribute most to elevated blood lead concentrations in children in Karachi. METHODS: A total of 430 children aged 36-60 months were selected through a geographically stratified design from the city centre, two suburbs, a rural community and an island situated within the harbour at Karachi. Blood samples were collected from children and a pretested questionnaire was administered to assess the effect of various types of exposure. Cooked food, drinking-water and house dust samples were collected from households. FINDINGS: About 80% of children had blood lead concentrations 10 g/dl, with an overall mean of 15.6 g/dl. At the 5% level of significance, houses nearer to the main intersection in the city centre, application of surma to children's eyes, father's exposure to lead at workplace, parents' illiteracy and child's habit of hand- to-mouth activity were among variables associated with elevated lead concentrations in blood. CONCLUSION: These findings are of public health concern, as most children in Karachi are likely to suffer some degree of intellectual impairment as a result of environmental lead exposure. We believe that there is enough evidence of the continuing problem of lead in petrol to prompt the petroleum industry to take action. The evidence also shows the need for appropriate interventions in reducing the burden due to other factors associated with this toxic element. PMID:12471396

  9. [Effects of elevated rhizosphere CO2 concentration on the photosynthetic characteristics, yield, and quality of muskmelon].

    PubMed

    Liu, Yi-Ling; Sun, Zhou-Ping; Li, Tian-Lai; Gu, Feng-Ying; He, Yu

    2013-10-01

    By using aeroponics culture system, this paper studied the effects of elevated rhizosphere CO2 concentration on the leaf photosynthesis and the fruit yield and quality of muskmelon during its anthesis-fruiting period. In the fruit development period of muskmelon, as compared with those in the control (350 microL CO2 x L (-1)), the leaf chlorophyll content, net photosynthetic rate (Pn), stomatal conductance (Gs), intercellular CO2 concentration (Ci), and the maximal photochemical efficiency of PS II (Fv/Fm) in treatments 2500 and 5000 microL CO2 x L(-1) decreased to some extents, but the stomatal limitation value (Ls) increased significantly, and the variation amplitudes were larger in treatment 5000 microL CO2 x L(-1) than in treatment 2500 microL CO2 x L(-1). Under the effects of elevated rhizosphere CO2 concentration, the fruit yield per plant and the Vc and soluble sugar contents in fruits decreased markedly, while the fruit organic acid content was in adverse. It was suggested that when the rhizosphere CO2 concentration of muskmelon during its anthesis-fruiting period reached to 2500 microL x L(-1), the leaf photosynthesis and fruit development of muskmelon would be depressed obviously, which would result in the decrease of fruit yield and quality of muskmelon.

  10. Identification of potential source areas for elevated PM2.5, nitrate and sulfate concentrations

    NASA Astrophysics Data System (ADS)

    Heo, Jongbae; McGinnis, Jerome E.; de Foy, Benjamin; Schauer, James J.

    2013-06-01

    Extreme events or episodes of ambient fine particulate matter (PM2.5), in which daily mass concentrations are substantially higher than annual averages, have been frequently observed in southern Wisconsin, US. Determining the cause of events has been a great challenge to local governments responsible for protecting public health and complying with the 24-h PM2.5 standard. This study analyzed air parcel movements originating from emission source areas, and trends in PM2.5 concentrations in order to determine the important factors involved in elevated PM2.5 episodes in the region. A single backward trajectory analysis coupled with PM2.5 concentrations observed at Federal Reference Method Network (FRM) sites in Madison, Milwaukee and Waukesha; and nitrate and sulfate concentrations monitored at a Chemical Speciation Network (CSN) site in Milwaukee, Wisconsin, from 2002 to 2010 were examined. The PM2.5 concentrations from the FRM showed the total PM2.5 mass during the episodes were higher in Madison than in Milwaukee and Waukesha, while annual average concentrations were lower in Madison. However, the temporal trend in frequency of elevated PM2.5 episodes was remarkably similar across sites during the entire study period and high frequency episodes occurring from 2005 to 2007. Residence time analysis of backward trajectories calculated for all recorded data indicated episode changes were mainly driven by year-to-year variations of air mass movements originating in high emissions areas. Potential Source Contribution Function (PSCF) results showed the extreme events of PM2.5 occurred during times when trajectories passed over ammonia emissions hotspots as well as large stationary emissions. Enhanced nitrate and sulfate concentrations which were the major episode components were strongly influenced by air masses trajectories originating from the Ohio River Valley and adjacent states.

  11. Different responses of transgenic Bt rice and conventional rice to elevated ozone concentration.

    PubMed

    Li, Chunhua; Zhu, Jianguo; Zeng, Qing; Luo, Keju; Liu, Biao; Liu, Gang; Tang, Haoye

    2017-03-01

    To assess the different sensitivity to ozone (O3) between transgenic Bt Shanyou63 (Bt-SY63) and its nontransgenic counterpart Shanyou63 (SY63), the leaf gas exchange, yield, grain elements, and antioxidant enzymes were investigated by performing a pot experiment under ambient O3 concentration (A-O3) and elevated O3 concentration (1.5 × A-O3, E-O3). Under A-O3, the chlorophyll content and yield of Bt-SY63 were significantly lower than those of SY63, whereas the stomatal conductance (Gs), cellular CO2 concentration (Ci), and Fe, Zn concentration showed the opposite trends. No significant difference was detected for malondialdehyde (MDA) content between two cultivars, although the antioxidant enzymes including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities in Bt-SY63 tended to be higher than those in SY63. Exposure to E-O3 resulted in significant reduction for photosynthesis (Pn), yield and all grain elements (except for N) concentration in both varieties, and the extents in Bt-SY63 were much greater than those in SY63. Meanwhile, significant increases for MDA content by 30.6 and 23.7% in Bt-SY63 and SY63, respectively, were detected under E-O3. These results demonstrated that insertion of exogenous gene could induce several unintentional changes of Bt-SY63 in physiology and growth progress, compared with SY63 under ambient O3 concentration. On the other hand, the injury of Bt-SY63 caused by elevated O3 concentration was more severe than that of SY63. This study provided valuable baseline information for the commercial release and breeding strategies of Bt-SY63 under the projected future climate.

  12. [Effects of drought stress, high temperature and elevated CO2 concentration on the growth of winter wheat].

    PubMed

    Si, Fu-Yan; Qiao, Yun-Zhou; Jiang, Jing-Wei; Dong, Bao-Di; Shi, Chang-Hai; Liu, Meng-Yu

    2014-09-01

    The impacts of climate change on the grain yield, photosynthesis, and water conditions of winter wheat were assessed based on an experiment, in which wheat plants were subjected to ambient and elevated CO2 concentrations, ambient and elevated temperatures, and low and high water conditions independently and in combination. The CO2 enrichment alone had no effect on the photosynthesis of winter wheat, whereas higher temperature and drought significantly decreased the photosynthetic rate. Water conditions in flag leaves were not significantly changed at the elevated CO2 concentration or elevated temperature. However, drought stress decreased the relative water content in flag leaves, and the combination of elevated temperature and drought reduced the water potential in flag leaves. The combination of elevated CO2 concentration, elevated temperature, and drought significantly reduced the photosynthetic rate and water conditions, and led to a 41.4% decrease in grain yield. The elevated CO2 concentration alone increased the grain yield by 21.2%, whereas the elevated temperature decreased the grain yield by 12.3%. The grain yield was not affected by the combination of elevated CO2 concentration and temperature, but the grain yield was significantly decreased by the drought stress if combined with any of the climate scenarios applied in this study. These findings suggested that maintaining high soil water content might be a vital means of reducing the potential harm caused by the climate change.

  13. [Clinical research on improvement of glucose metabolic marker level by coffee drinking-validity of saliva caffeine concentration measurement].

    PubMed

    Okada, Tomoko; Kobayashi, Daisuke; Kono, Suminori; Shimazoe, Takao

    2010-05-01

    We measured both serum and saliva caffeine concentration using HPLC and assessed the correlation between them in volunteers with mild obesity. Significant correlation was shown between saliva and serum caffeine concentration. It may be necessary to measure caffeine metabolite concentration because its metabolites may also have an improving effect of glucose metabolism. In summary, we found that saliva caffeine concentration measurement was useful to assess caffeine intake level. Moreover, it will be helpful to know whether caffeine has an improving effect of glucose metabolism.

  14. In Vitro Infection of Trypanosoma cruzi Causes Decrease in Glucose Transporter Protein-1 (GLUT1) Expression in Explants of Human Placental Villi Cultured under Normal and High Glucose Concentrations

    PubMed Central

    Mezzano, Luciana; Repossi, Gastón; Fretes, Ricardo E.; Lin, Susana; Sartori, María José; de Fabro, Sofía G. Parisi

    2012-01-01

    Trypanosoma cruzi, the etiologic Chagas' disease agent, induces changes in protein pattern of the human placenta syncytiotrophoblast. The glucose transporter protein-1 (GLUT1) is the primary isoform involved in transplacental glucose transport. We carried out in vitro assays to determine if T. cruzi infection would induce changes in placental GLUT1 protein expression under normal and high concentration of glucose. Using Western blot and immunohistological techniques, GLUT1 expression was determined in normal placental villi cultured under normal or high concentrations of glucose, with or without in vitro T. cruzi infection, for 24 and 48 hours. High glucose media or T. cruzi infection alone reduced GLUT1 expression. A yet more accentuated reduction was observed when infection and high glucose condition took place together. We inform, for the first time, that T. cruzi infection may induce reduction of GLUT1 expression under normal and high glucose concentrations, and this effect is synergic to high glucose concentrations. PMID:21941569

  15. In Vitro Infection of Trypanosoma cruzi Causes Decrease in Glucose Transporter Protein-1 (GLUT1) Expression in Explants of Human Placental Villi Cultured under Normal and High Glucose Concentrations.

    PubMed

    Mezzano, Luciana; Repossi, Gastón; Fretes, Ricardo E; Lin, Susana; Sartori, María José; de Fabro, Sofía G Parisi

    2012-01-01

    Trypanosoma cruzi, the etiologic Chagas' disease agent, induces changes in protein pattern of the human placenta syncytiotrophoblast. The glucose transporter protein-1 (GLUT1) is the primary isoform involved in transplacental glucose transport. We carried out in vitro assays to determine if T. cruzi infection would induce changes in placental GLUT1 protein expression under normal and high concentration of glucose. Using Western blot and immunohistological techniques, GLUT1 expression was determined in normal placental villi cultured under normal or high concentrations of glucose, with or without in vitro T. cruzi infection, for 24 and 48 hours. High glucose media or T. cruzi infection alone reduced GLUT1 expression. A yet more accentuated reduction was observed when infection and high glucose condition took place together. We inform, for the first time, that T. cruzi infection may induce reduction of GLUT1 expression under normal and high glucose concentrations, and this effect is synergic to high glucose concentrations.

  16. Elevated serum concentrations of soluble adhesion molecules in coronary artery disease and acute myocardial infarction.

    PubMed

    Zeitler, H; Ko, Y; Zimmermann, C; Nickenig, G; Glänzer, K; Walger, P; Sachinidis, A; Vetter, H

    1997-09-29

    Adhesion molecules are involved in a number of chronic conditions and diseases like rheumatoid arthritis, tumor growth and wound repair. Soluble adhesion molecules (SAM) play an important role in angiogenesis which is a common aspect of the conditions mentioned above and atherosclerosis. The aim of the present study was to assess the prevalence and the impact of elevated soluble adhesive molecule plasma concentrations in patients with atherosclerosis. In this study, we measured the soluble forms of intercellular adhesive molecule (sICAM), endothelial adhesive molecule (sELAM) and vascular adhesive molecule (sVCAM) using a sandwich ELISA technique in plasma of patients with acute myocardial infarction (AMI), coronary heart disease (CHD) and in healthy subjects (HS). Patients suffering from CHD and AMI showed significant higher plasma concentrations of sICAM (p <0. 05 and p <0.005), sELAM (p <0.01 and p <0.001) and sVCAM (p <0.001 and p <0.005) than HS. In patients with fatal outcome of myocardial infarction the plasma concentrations of sICAM, sELAM and sVCAM were significantly elevated compared to surviving patients (p <0.005; p <0.005; p <0.05). In patients undergoing thrombolytic therapy there were no significant differences of plasma adhesive molecule concentrations. The levels of SAM were not related to other risk factors like diabetes, nicotin abuse, hyperlipidemia, hypertension and a familiary history of cardiovascular disease. Elevated levels of SAMs are found in patients with coronary heart disease. High SAM levels in plasma seem to be a prognostic factor in acute myocardial infarction. This effect is independent from other concomitant risk factors. Our results suggest that SAMs are involved both in acute phase of myocardial infarction and chronic process of atherosclerosis. It seems that similiar to other chronic inflammatory diseases, atherosclerosis seems to be modulated by soluble forms of adhesive molecules.

  17. Elevated white blood cell count is associated with higher risk of glucose metabolism disorders in middle-aged and elderly Chinese people.

    PubMed

    Jiang, Hua; Yan, Wen-Hua; Li, Chan-Juan; Wang, An-Ping; Dou, Jing-Tao; Mu, Yi-Ming

    2014-05-20

    White blood cell (WBC) count has been associated with diabetic risk, but whether the correlation is independent of other risk factors has hardly been studied. Moreover, very few such studies with large sample sizes have been conducted in Chinese. Therefore, we investigated the relationship between WBC count and glucose metabolism in China. We also examined the relevant variables of WBC count. A total of 9,697 subjects (mean age, 58.0 ± 9.1 years) were recruited. The subjects were classified into four groups, including subjects with normal glucose tolerance, isolated impaired fasting glucose, impaired glucose tolerance and type 2 diabetes mellitus (T2DM). We found that WBC count increased as glucose metabolism disorders exacerbated. WBC count was also positively correlated with waist hip ratio, body mass index, smoking, triglycerides, glycosylated haemoglobin A1c (HbA1c) and 2-h postprandial glucose. In addition, high density lipoprotein and the female gender were inversely correlated with WBC levels. In patients with previously diagnosed T2DM, the course of T2DM was not correlated with WBC count. Our findings indicate that elevated WBC count is independently associated with worsening of glucose metabolism in middle-aged and elderly Chinese. In addition, loss of weight, smoking cessation, lipid-modifying therapies, and control of postprandial plasma glucose and HbA1c may ameliorate the chronic low-grade inflammation.

  18. The impairment of glucose-stimulated insulin secretion in pancreatic β-cells caused by prolonged glucotoxicity and lipotoxicity is associated with elevated adaptive antioxidant response.

    PubMed

    Fu, Jingqi; Cui, Qi; Yang, Bei; Hou, Yongyong; Wang, Huihui; Xu, Yuanyuan; Wang, Difei; Zhang, Qiang; Pi, Jingbo

    2017-02-01

    Type 2 diabetes (T2D) is a progressive disease characterized by sustained hyperglycemia and is frequently accompanied by hyperlipidemia. Deterioration of β-cell function in T2D patients may be caused, in part, by long-term exposure to high concentrations of glucose and/or lipids. We developed systems to study how chronic glucotoxicity and lipotoxicity might be linked to the impairment of glucose-stimulated insulin secretion (GSIS) machinery in pancreatic β-cells. INS-1 (832/13) were exposed to glucose and/or palmitate for up to 10 weeks. Chronic high glucose and/or palmitate exposure resulted in impaired GSIS accompanied by a dramatic increase in oxidative stress, as determined by basal intracellular peroxide levels. In addition, the GSIS-associated reactive oxygen species (ROS) signals, assessed as glucose-stimulated peroxide accumulation positively correlated with GSIS in glucose- and/or palmitate-exposed cells, as well as glucose-stimulated reductions in GSH/GSSG ratios. Furthermore, the impairment of GSIS caused by chronic high glucose and/or palmitate exposures were attributed to the induction of adaptive antioxidant response and mitochondrial uncoupling, which negatively regulates glucose-derived ROS generation. Taken together, persistent glucotoxicity- and/or lipotoxicity-mediated oxidative stress and subsequent adaptive antioxidant response impair glucose-derived ROS signaling and GSIS in pancreatic β-cells. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Retrospective Study of Cryptococcal Meningitis With Elevated Minimum Inhibitory Concentration to Fluconazole in Immunocompromised Patients.

    PubMed

    Nasri, Hashem; Kabbani, Sarah; Bou Alwan, Melhim; Wang, Yun F; Rebolledo, Paulina A; Kraft, Colleen S; Nguyen, Minh L; Anderson, Albert M; Rouphael, Nadine

    2016-04-01

    Background.  Mortality for cryptococcal meningitis remains significant, in spite of available treatment. Resistance to first-line maintenance therapy, particularly fluconazole, has been reported. Methods.  A retrospective chart review was performed on immunocompromised patients with cryptococcal meningitis, who had susceptibility testing performed between January 2001 and December 2011, at 3 hospitals in Atlanta, Georgia. Results.  A total of 35 immunocompromised patients with cryptococcal meningitis were identified, 13 (37.1%) of whom had an elevated minimum inhibitory concentration (MIC) to fluconazole (MIC ≥16 µg/mL). Eighty percent of patients were males with African American predominance, the median age was 37 years, and 80% of the patients were human immunodeficiency virus (HIV) positive. Subsequent recurrence of cryptococcal meningitis was more likely in HIV patients compared with solid organ transplant patients (P = .0366). Overall, there was a statistically significant increase in an elevated MIC to fluconazole in patients who had a history of prior azole use (odds ratio, 10.12; 95% confidence interval, 2.04-50.16). Patients with an elevated MIC to fluconazole and those with a high cerebrospinal fluid cryptococcal antigen load (≥1:512) were more likely to have central nervous system complications (P = .0358 and P = .023, respectively). Although no association was observed between an elevated MIC to fluconazole and mortality, those who received voriconazole or high-dose fluconazole (≥800 mg) for maintenance therapy were more likely to survive (P = .0288). Conclusions.  Additional studies are required to further investigate the morbidity and mortality associated with an elevated MIC to fluconazole in cryptococcal meningitis, to determine when it is appropriate to perform susceptibility testing, and to evaluate its cost effectiveness.

  20. Postprandial serum C-peptide to plasma glucose concentration ratio correlates with oral glucose tolerance test- and glucose clamp-based disposition indexes.

    PubMed

    Okuno, Yoko; Komada, Hisako; Sakaguchi, Kazuhiko; Nakamura, Tomoaki; Hashimoto, Naoko; Hirota, Yushi; Ogawa, Wataru; Seino, Susumu

    2013-10-01

    The C-peptide index (CPI), a ratio of serum C-peptide to plasma glucose levels, is a readily measured index of β-cell function. The difference in the physiological features reflected by the index measured under fasting (F-CPI) or postprandial (PP-CPI) conditions has remained unclear, however. We investigated the relationship of the two CPIs to indexes of insulin secretion measured with an oral glucose tolerance test (OGTT) or with hyperglycemic and hyperinsulinemic-euglycemic clamp analyses as well as to disposition indexes (indexes of insulin secretion adjusted for insulin sensitivity) calculated from OGTT- or clamp-based analyses. We also examined the relationship between glucose tolerance and the clamp-based disposition index. The clamp-based disposition index declined progressively from normal glucose tolerance to impaired glucose tolerance to Type 2 diabetes, and it strongly correlated with the 2-h plasma glucose level during an OGTT. For patients with Type 2 diabetes, both F-CPI and PP-CPI correlated with indexes of insulin secretion including HOMA-β, the insulinogenic index, the ratio of the area under the insulin curve to that under the glucose curve during an OGTT, the serum C-peptide level after glucagon challenge, as well as early and total insulin secretion measured with a hyperglycemic clamp. PP-CPI, but not F-CPI, was significantly correlated with clamp-based and OGTT-based disposition indexes. F-CPI was correlated only with unadjusted indexes of insulin secretion, whereas PP-CPI was correlated with such indexes as well as with those adjusted for insulin sensitivity. The better clinical utility of PP-CPI might be attributable to these physiological characteristics. Copyright © 2013 Elsevier Inc. All rights reserved.

  1. Serum fetuin A concentration is elevated in children with non-alcoholic fatty liver disease.

    PubMed

    Lebensztejn, Dariusz M; Białokoz-Kalinowska, Irena; Kłusek-Oksiuta, Monika; Tarasów, Eugeniusz; Wojtkowska, Małgorzata; Kaczmarski, Maciej

    2014-03-01

    To assess the serum fetuin A concentration as a potential marker of subclinical atherosclerosis in obese children with NAFLD. A prospective analysis of 45 obese children initially diagnosed with liver pathology (elevated serum ALT activity and/or ultrasonographic liver brightness and/or hepatomegaly) was conducted. The diagnosis of NAFLD was established in the children with elevated serum ALT activity and liver steatosis on ultrasound examination. Viral hepatitis, autoimmune, metabolic liver diseases (Wilson disease, alpha-1-antitrypsin deficiency, cystic fibrosis) and drug and toxin-induced liver injury were excluded in all children. The degree of liver steatosis was graded according to Saverymuttu scale and the total liver lipids concentration was assessed using proton magnetic resonance spectroscopy ((1)H MRS). Serum fetuin A concentration was significantly higher in examined children compared to the control group (n=30) (p=0.00002). Higher serum fetuin A concentration was also observed in children with NAFLD (n=19) in comparison to the controls (p=0.000026). Additionally, higher BMI values, waist circumferences, ALT and GGT activity, intensity of liver steatosis on ultrasound and total concentration of lipids in the liver in (1)H MRS were found in children with NAFLD compared to the rest of the examined obese patients (n=26). There was not found any correlation of the investigated glycoprotein with any other assessed parameters both in children with NAFLD and obese children without NAFLD. Higher serum fetuin A concentration found in children with NAFLD compared to the control group support the hypothesis that atherosclerotic processes may develop faster in hepatopatic obese patients. Copyright © 2014 Medical University of Bialystok. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  2. Peripheral and central venous blood glucose concentrations in dogs and cats with acute arterial thromboembolism.

    PubMed

    Klainbart, S; Kelmer, E; Vidmayer, B; Bdolah-Abram, T; Segev, G; Aroch, I

    2014-01-01

    Acute limb paralysis because of arterial thromboembolism (ATE) occurs in cats and less commonly in dogs. ATE is diagnosed based on physical examination findings and, occasionally, advanced imaging. Peripheral, affected limb venous glucose concentration is decreased in ATE, whereas its systemic concentration is within or above reference interval. Client-owned cats and dogs were divided into 3 respective groups: acute limb paralysis because of ATE (22 cats and 9 dogs); acute limb paralysis secondary to orthopedic or neurologic conditions (nonambulatory controls; 10 cats and 11 dogs); ambulatory animals presented because of various diseases (ambulatory controls; 10 cats and 9 dogs). Prospective observational, clinical study. Systemic and local (affected limb) blood glucose concentrations were measured. Their absolute and relative differences (ΔGlu and %ΔGlu, respectively) were compared among groups. ΔGlu and %ΔGlu were significantly higher in the ATE cats and dogs groups, compared to both of their respective controls (P < .0001 and P < .001, respectively). No significant differences were observed between the control groups. Receiver operator characteristics analysis of ΔGlu and %ΔGlu as predictors of ATE had area under the curve of 0.96 and 0.99 in cats, respectively, and 1.00 and 1.00, in dogs, respectively. ΔGlu cutoffs of 30 mg/dL and 16 mg/dL, in cats and dogs, respectively, corresponded to sensitivity and specificity of 100% and 90% in cats, respectively, and 100% in dogs. ΔGlu and %ΔGlu are accurate, readily available, diagnostic markers of acute ATE in paralyzed cats and dogs. Copyright © 2014 by the American College of Veterinary Internal Medicine.

  3. Oral green tea catechins transiently lower plasma glucose concentrations in female db/db mice.

    PubMed

    Wein, Silvia; Schrader, Eva; Rimbach, Gerald; Wolffram, Siegfried

    2013-04-01

    Polyphenols, including green tea catechins, are secondary plant compounds often discussed in the context of health-promoting potential. Evidence for such effects is mainly derived from epidemiological and cell culture studies. The aim of the present study was to investigate antidiabetic, antiadipogenic, and anti-inflammatory effects at nonpharmacological doses in an obese diabetic mouse model that exerts early relevant clinical signs of non-insulin-dependent diabetes mellitus. Female db/db mice received a flavonoid-poor diet either without additive, with rosiglitazone (RSG, 0.02 g/kg diet), or with green tea extract (low-dose green tea extract [LGTE] and high-dose green tea extract [HGTE], 0.1 and 1 g/kg diet). Food and water were freely available. The body weight was monitored weekly. Blood was sampled (12-h fasted) from the tail vein on day 28 and analyzed for glucose, cholesterol, triacylglycerol, nonesterified fatty acids, insulin, adiponectin, and soluble intercellular adhesion molecule-1 (sICAM-1). Blood glucose was also analyzed on day 14. Furthermore, sICAM-1 release was investigated in tumor necrosis factor alpha-stimulated EAhy926 cells. After 14 days, fasting glycemia was improved by RSG or HGTE supplementation compared to controls. However, at the end of the study (day 28), only RSG exhibited glucose-lowering effects and induced plasma adiponectin concentrations, paralleled by higher body weight gain and reduced periuterine fat pads compared to controls. However, only GTE treatment reduced sICAM-1 release in vitro and in vivo. Nonpharmacological HGTE supplementation in db/db mice caused (1) no adiponectin-inducing or antiadipogenic effects, (2) reduced sICAM-1 release, thereby potentially exerting anti-inflammatory effects in the progressive diabetic state, and (3) a transient improvement in glycemia.

  4. Elevation of brain glucose and polyol-pathway intermediates with accompanying brain-copper deficiency in patients with Alzheimer’s disease: metabolic basis for dementia

    PubMed Central

    Xu, Jingshu; Begley, Paul; Church, Stephanie J.; Patassini, Stefano; McHarg, Selina; Kureishy, Nina; Hollywood, Katherine A.; Waldvogel, Henry J.; Liu, Hong; Zhang, Shaoping; Lin, Wanchang; Herholz, Karl; Turner, Clinton; Synek, Beth J.; Curtis, Maurice A.; Rivers-Auty, Jack; Lawrence, Catherine B.; Kellett, Katherine A. B.; Hooper, Nigel M.; Vardy, Emma R. L. C.; Wu, Donghai; Unwin, Richard D.; Faull, Richard L. M.; Dowsey, Andrew W.; Cooper, Garth J. S.

    2016-01-01

    Impairment of brain-glucose uptake and brain-copper regulation occurs in Alzheimer’s disease (AD). Here we sought to further elucidate the processes that cause neurodegeneration in AD by measuring levels of metabolites and metals in brain regions that undergo different degrees of damage. We employed mass spectrometry (MS) to measure metabolites and metals in seven post-mortem brain regions of nine AD patients and nine controls, and plasma-glucose and plasma-copper levels in an ante-mortem case-control study. Glucose, sorbitol and fructose were markedly elevated in all AD brain regions, whereas copper was correspondingly deficient throughout (all P < 0.0001). In the ante-mortem case-control study, by contrast, plasma-glucose and plasma-copper levels did not differ between patients and controls. There were pervasive defects in regulation of glucose and copper in AD brain but no evidence for corresponding systemic abnormalities in plasma. Elevation of brain glucose and deficient brain copper potentially contribute to the pathogenesis of neurodegeneration in AD. PMID:27276998

  5. Elevated manganese concentrations in drinking water may be beneficial for fetal survival.

    PubMed

    Rahman, Syed Moshfiqur; Akesson, Agneta; Kippler, Maria; Grandér, Margaretha; Hamadani, Jena Derakhshani; Streatfield, Peter Kim; Persson, Lars-Åke; El Arifeen, Shams; Vahter, Marie

    2013-01-01

    Elevated exposure to the essential element manganese (Mn) can be toxic. Manganese concentrations in ground water vary considerably, and reported associations between Mn and early-life mortality and impaired development have raised concern. We assessed the effects of drinking water Mn exposure during pregnancy upon fetal and infant survival. In this population-based cohort study, we identified the outcomes of pregnancies registered between February 2002 and April 2003 in Matlab, Bangladesh. Using inductively coupled plasma mass spectrometry, we measured the concentrations of Mn and other elements in the pregnant women's drinking water. A total of 1,875 women were included in the analysis of spontaneous abortions (n=158) and 1,887 women in the perinatal mortality analysis (n=70). Water Mn ranged from 3.0-6,550 µg/L (median=217 µg/L). The adjusted odds ratio (OR) for spontaneous abortion was 0.65 (95% CI 0.43-0.99) in the highest water Mn tertile (median=1,292 µg/L) as compared to the lowest tertile (median=56 µg/L). The corresponding OR for perinatal mortality was 0.69 (95% CI 0.28-1.71), which increased to 0.78 (95% CI 0.29-2.08) after adjustment for BMI and place of delivery (home/health facility; n=1,648). Elevated water Mn concentrations during pregnancy appear protective for the fetus, particularly in undernourished women. This effect may be due to the element's role in antioxidant defense.

  6. Effect of acarbose on postprandial blood glucose concentrations in healthy cats fed low and high carbohydrate diets.

    PubMed

    Singh, Ranee; Rand, Jacquie S; Coradini, Marcia; Morton, John M

    2015-10-01

    Feeding a low carbohydrate diet is recommended for diabetic cats; however, some cats may require diets containing moderate-to-high carbohydrate and may benefit from the use of therapeutic agents to improve glycemic control. The aim of the study was to determine the effect of the α-glucosidase inhibitor acarbose on postprandial plasma glucose concentration when combined with commercially available feline diets high and low in carbohydrate. Twelve healthy, adult, non-obese, neutered cats were enrolled. Plasma glucose concentrations were assessed over 24 h after feeding high and low carbohydrate diets, with and without acarbose, during single and multiple meal tests, in a crossover study. Commercially available feline diets were used, which were high and low in carbohydrate (providing 51% and 7% of metabolizable energy, respectively). In cats fed the high carbohydrate diet as a single meal, mean 24 h glucose concentrations were lower when acarbose was administered. Mean glucose concentrations were lower in the first 12 h when acarbose was given once daily, whereas no significant difference was observed in mean results from 12-24 h. Acarbose had little effect in cats eating multiple meals. Compared with consumption of the high carbohydrate diet with acarbose, lower mean 24 h and peak glucose concentrations were achieved by feeding the low carbohydrate diet alone. In healthy cats meal-fed diets of similar composition to the diets used in this study, acarbose has minimal effect when a low carbohydrate diet is fed but reduces postprandial glucose concentrations over 24 h when a high carbohydrate diet is fed. However, mean glucose concentrations over 24 h are still higher when a high carbohydrate diet with acarbose is fed relative to the low carbohydrate diet without acarbose. Future studies in diabetic cats are warranted to confirm these findings. © ISFM and AAFP 2014.

  7. Cocaine use is associated with a higher prevalence of elevated ST2 concentrations.

    PubMed

    van Wijk, Xander M R; Vittinghoff, Eric; Wu, Alan H B; Lynch, Kara L; Riley, Elise D

    2017-09-01

    Cocaine is a well-known risk factor for acute cardiac events, but the effects in users outside of acute events are less clear. We investigated a possible association between cocaine use and the concentration of a novel biomarker for cardiac stress and heart failure, ST2. A case-control study was conducted to compare ST2 concentrations by the presence of cocaine in patients presenting for care, but not cardiac care, at an urban safety net hospital. In samples taken from 100 cocaine-positive and 100 cocaine-negative patients, the presence of cocaine was associated with ST2 concentrations>35ng/mL. Serum concentrations of benzoylecgonine, a major cocaine metabolite, were significantly correlated with ST2 concentrations. Cocaine use is associated with subclinical cardiac stress and damage outside of acute cardiac events. This information could add to better stratification of cocaine users with elevated ST2 concentrations who may be at higher risk for developing heart failure and other cardiac complications. Copyright © 2017 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  8. The impact of seasonality and elevation on dissolved greenhouse gas concentrations in a northeastern Wyoming watershed

    NASA Astrophysics Data System (ADS)

    Kuhn, C.; Bettigole, C.; Raymond, P. A.; Glick, H.; Seegmiller, L.; Oliver, C.; Khadka, A.; Routh, D.

    2014-12-01

    Quantification of river and stream contributions to global carbon emission budgets using field-based measurements is key to understanding how freshwater streams act as conduits between terrestrial and atmospheric carbon pools. In order to better characterize drivers of this process, this study quantifies: a) emissions of carbon dioxide and methane from a semi-arid, high plains riverine system with montaine headwaters in order to establish baseline data for the watershed; b) the impact of stream order, seasonality and elevation on dissolved gas concentrations to better understand the spatial and temporal heterogeneity of dissolved carbon gases. To achieve the latter objective, we conducted field surveys in first and second order streams in the Clear Creek drainage of the Powder River Basin watershed. We took direct measurements of stream gases using headspace sampling at thirty sites along an elevation gradient ranging from 1,203-3,346 meters. We also intensely monitored five transects throughout the descending limb of spring runoff (June 8th-August 12th) to investigate how temperature and discharge volume impact greenhouse gas concentrations. Clear Creek, located in northeastern Wyoming, is approximately 118.4 km long with a drainage area of 2,968 km2. The creek flows east out of Bighorn National Forest where it turns northeast to converge with the Powder River about ten miles before the Montana border. The stream straddles the Middle Rockies and Northwestern Great Plains ecoregions and experiences an abrupt shift in soil type, riparian vegetation, underlying geology and stream geometry as the stream exits the mountains and enters the agricultural alluvial floodplain. These site specific biological and physical changes along the elevation gradient affect dissolved greenhouse gas concentrations.

  9. Regulation of hormonal responses of sweet pepper as affected by salinity and elevated CO2 concentration.

    PubMed

    Piñero, María Carmen; Houdusse, Fabrice; Garcia-Mina, Jose M; Garnica, María; Del Amor, Francisco M

    2014-08-01

    This study examines the extent to which the predicted CO2 -protective effects on the inhibition of growth, impairment of photosynthesis and nutrient imbalance caused by saline stress are mediated by an effective adaptation of the endogenous plant hormonal balance. Therefore, sweet pepper plants (Capsicum annuum, cv. Ciclón) were grown at ambient or elevated [CO2] (400 or 800 µmol mol(-1)) with a nutrient solution containing 0 or 80 mM NaCl. The results show that, under saline conditions, elevated [CO2] increased plant dry weight, leaf area, leaf relative water content and net photosynthesis compared with ambient [CO2], whilst the maximum potential quantum efficiency of photosystem II was not modified. In salt-stressed plants, elevated [CO2 ] increased leaf NO3(-) concentration and reduced Cl(-) concentration. Salinity stress induced ABA accumulation in the leaves but it was reduced in the roots at high [CO2], being correlated with the stomatal response. Under non-stressed conditions, IAA was dramatically reduced in the roots when high [CO2] was applied, which resulted in greater root DW and root respiration. Additionally, the observed high CK concentration in the roots (especially tZR) could prevent downregulation of photosynthesis at high [CO2], as the N level in the leaves was increased compared with the ambient [CO2], under salt-stress conditions. These results demonstrate that the hormonal balance was altered by the [CO2], which resulted in significant changes at the growth, gas exchange and nutritional levels. © 2013 Scandinavian Plant Physiology Society.

  10. Spring leaf flush in aspen (Populus tremuloides) clones is altered by long-term growth at elevated carbon dioxide and elevated ozone concentration.

    PubMed

    McGrath, Justin M; Karnosky, David F; Ainsworth, Elizabeth A

    2010-04-01

    Early spring leaf out is important to the success of deciduous trees competing for light and space in dense forest plantation canopies. In this study, we investigated spring leaf flush and how long-term growth at elevated carbon dioxide concentration ([CO(2)]) and elevated ozone concentration ([O(3)]) altered leaf area index development in a closed Populus tremuloides (aspen) canopy. This work was done at the Aspen FACE experiment where aspen clones have been grown since 1997 in conditions simulating the [CO(2)] and [O(3)] predicted for approximately 2050. The responses of two clones were compared during the first month of spring leaf out when CO(2) fumigation had begun, but O(3) fumigation had not. Trees in elevated [CO(2)] plots showed a stimulation of leaf area index (36%), while trees in elevated [O(3)] plots had lower leaf area index (-20%). While individual leaf area was not significantly affected by elevated [CO(2)], the photosynthetic operating efficiency of aspen leaves was significantly improved (51%). There were no significant differences in the way that the two aspen clones responded to elevated [CO(2)]; however, the two clones responded differently to long-term growth at elevated [O(3)]. The O(3)-sensitive clone, 42E, had reduced individual leaf area when grown at elevated [O(3)] (-32%), while the tolerant clone, 216, had larger mature leaf area at elevated [O(3)] (46%). These results indicate a clear difference between the two clones in their long-term response to elevated [O(3)], which could affect competition between the clones, and result in altered genotypic composition in future atmospheric conditions.

  11. Elevated Glyoxal Concentrations over the Eastern Equatorial Pacific: A Direct Biogenic Source?

    NASA Astrophysics Data System (ADS)

    Zhang, R.; Wang, Y.; Lerot, C.

    2014-12-01

    Elevated atmospheric glyoxal (CHOCHO) was observed over the eastern equatorial Pacific by satellite and ship measurements. We investigated the source contributions through inverse modeling using GOME-2 observations (2007-2012) and the GEOS-Chem model. The observed high glyoxal to HCHO column ratio over the region indicates the potential presence of a direct source of glyoxal rather than secondary production. A bimodal seasonal cycle of glyoxal concentrations was found, providing further evidence for a biogenic origin of glyoxal emission. The estimate of the primary glyoxal emission over the eastern equatorial Pacific is 20-40Tg/yr, which is comparable to the previous estimate of the global continential glyoxal emission.

  12. Reducing dietary fat from a meal increases the bioavailability of exogenous carbohydrate without altering plasma glucose concentration

    PubMed Central

    Knuth, Nicolas D.; Shrivastava, Cara R.; Horowitz, Jeffrey F.

    2009-01-01

    The primary goal of this study was to determine the acute glycemic and endocrine responses to the reduction of fat content from a meal. On three separate occasions, nine overweight subjects (body mass index = 30 ± 1 kg/m2; 5 men, 4 women) consumed 1) a control meal (∼800 kcal; 100 g of carbohydrate, 31 g of fat, and 30 g of protein), 2) a low-fat meal (∼530 kcal; 100 g of carbohydrate, 1 g of fat, and 30 g of protein), or 3) a low-fat meal plus lipid infusion [same meal as low-fat meal, but the total energy provided was the same as control (800 kcal), with the “missing” fat (∼30 g) provided via an intravenous lipid infusion]. All three meals contained [13C]glucose (3 mg/kg body wt) to assess the bioavailability of ingested glucose. During the 5-h period after each meal, we measured the recovery of [13C]glucose in plasma, plasma glucose, and insulin concentrations. We also measured plasma concentration of the gastrointestinal peptides: glucose-dependent insulinotropic polypeptide (GIP), glucagon-like peptide-1 (GLP-1), and peptide YY3-36 (PYY3-36). The recovery of the ingested [13C]glucose in the hour after ingestion was greater (P < 0.05) after the low-fat than after the control meal [area under the curve (AUC): 1,206 ± 252 and 687 ± 161 μM·h, respectively]. However, removing dietary fat from the meal did not affect the plasma concentration of glucose or insulin. Importantly, [13C]glucose recovery was not different during the low-fat and lipid infusion trials (AUC: 1,206 ± 252 and 1,134 ± 247 μM·h, respectively), indicating that the accelerated delivery of exogenous glucose found after removing fat from the meal is due exclusively to the reduction of fat in the gastrointestinal tract. In parallel with these findings, the reduction in fat calories from the meal reduced plasma concentration of GIP, GLP-1, and PYY3-36. In summary, these data suggest that removing fat from the diet expedited exogenous glucose delivery into the systemic circulation

  13. Behavior of plastic and metal ameroid constrictors during in vitro incubation in physiologic solutions of varying glucose concentration.

    PubMed

    Griffin, Maureen A; Hunt, Geraldine B; Epstein, Steven E

    2016-04-01

    The objective of this study was to evaluate the influence of ameroid constrictor (AC) composition as well as glucose concentration in the surrounding fluid on the rate and completeness of AC closure. In a pilot study, four ACs (two metal, two plastic) were incubated in a solution containing 100 mg/dL glucose, and in a follow-up study, two additional ACs (one metal, one plastic) were incubated in a solution of 100 mg/dL glucose and six ACs (three metal, three plastic) were incubated in a solution of 50 mg/dL glucose. Dimensions of the ACs were analyzed weekly for 57 days. No significant difference was found in the rate or overall proportionate closure for either metal versus plastic ACs or ACs incubated in 50 mg/dL versus 100 mg/dL glucose. As there was no statistically significant difference in the proportionate closure of metal and plastic ACs, both types are clinically suitable for gradual attenuation of portosystemic shunts in animal patients. The lack of a significant difference in rate and completeness of closure of ACs incubated in different concentrations of glucose provides evidence that the glucose concentration of the surrounding fluid likely does not have a significant effect on AC closure. However, a significant difference in the proportionate closure of ACs occurred within the first week of the study between constrictors incubated in 50 mg/dL glucose and those incubated in 100 mg/dL glucose, and additional studies are indicated to determine the significance of this early difference in vivo.

  14. Inorganic Geochemistry of Flowback Water from the Montney Formation: Potential Sources of Elevated Ion Concentrations

    NASA Astrophysics Data System (ADS)

    Owen, J.; Bustin, R.

    2016-12-01

    An inorganic geochemical analysis was conducted on flowback water from hydraulically fractured oil and gas wells of the Montney Formation of varying thermal maturity and stratigraphy in the Western Canadian Sedimentary Basin. The results of this study provide insight into potential sources of the elevated ion concentrations and can be used to assist with wastewater management and blending of water for reuse. Samples were obtained from 31 wells across the Montney and include wells completed in the lower, middle, and upper units. Selected fluid samples from each well were analyzed using ICP-OES, ICP-MS, and IC. Oxygen and hydrogen isotope analysis was performed using a liquid-water isotope analyzer. The flowback waters are classified as sodium-chloride type. In addition to Na and Cl, calcium, potassium, magnesium, and strontium are elevated and increase during the flowback period. Barium, iron, and lithium are also elevated at some locations. The early flowback water chemistry varies within the formation: higher initial TDS values of approximately 50,000mg/L in Upper Montney flowback water relative to the initial TDS from both Middle and Lower Montney wells (<25,000mg/L and <15,000mg/L, respectively). However, overall, the maximum TDS attained later in the flowback period does not show a consistent stratigraphic trend (range: 55,000 - 130,000mg/L) except for one region in the Middle Montney where the maximum TDS remains consistently lower than other areas (<50,000mg/L). Barium is notable in Montney flowback due to its high variability, with the lowest concentrations occurring in Middle Montney flowback and the highest in Lower Montney flowback. Comparing closely spaced wells completed on the same pad and in the same zone, the flowback waters generally have similar ion concentrations and consistent ion ratios. The increasing ion concentrations as well as the stable water isotopes support mixing between the hydraulic fracturing fluid, which has relatively low ion

  15. A Low Frequency Electromagnetic Sensor for Indirect Measurement of Glucose Concentration: In Vitro Experiments in Different Conductive Solutions

    PubMed Central

    Tura, Andrea; Sbrignadello, Stefano; Cianciavicchia, Domenico; Pacini, Giovanni; Ravazzani, Paolo

    2010-01-01

    In recent years there has been considerable interest in the study of glucose-induced dielectric property variations of human tissues as a possible approach for non-invasive glycaemia monitoring. We have developed an electromagnetic sensor, and we tested in vitro its ability to estimate variations in glucose concentration of different solutions with similarities to blood (sodium chloride and Ringer-lactate solutions), differing though in the lack of any cellular components. The sensor was able to detect the effect of glucose variations over a wide range of concentrations (∼78–5,000 mg/dL), with a sensitivity of ∼0.22 mV/(mg/dL). Our proposed system may thus be useful in a new approach for non-invasive and non-contact glucose monitoring. PMID:22219665

  16. A low frequency electromagnetic sensor for indirect measurement of glucose concentration: in vitro experiments in different conductive solutions.

    PubMed

    Tura, Andrea; Sbrignadello, Stefano; Cianciavicchia, Domenico; Pacini, Giovanni; Ravazzani, Paolo

    2010-01-01

    In recent years there has been considerable interest in the study of glucose-induced dielectric property variations of human tissues as a possible approach for non-invasive glycaemia monitoring. We have developed an electromagnetic sensor, and we tested in vitro its ability to estimate variations in glucose concentration of different solutions with similarities to blood (sodium chloride and Ringer-lactate solutions), differing though in the lack of any cellular components. The sensor was able to detect the effect of glucose variations over a wide range of concentrations (∼78-5,000 mg/dL), with a sensitivity of ∼0.22 mV/(mg/dL). Our proposed system may thus be useful in a new approach for non-invasive and non-contact glucose monitoring.

  17. Noninvasive monitoring of blood glucose concentration in diabetic patients with optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Lan, Y. T.; Kuang, Y. P.; Zhou, L. P.; Wu, G. Y.; Gu, P. C.; Wei, H. J.; Chen, K.

    2017-03-01

    Optical coherence tomography (OCT) has been used to noninvasively monitor the blood glucose concentration (BGC) in healthy subjects with good accuracy and acceptable specificity. Based on this, the paper further considered the possibility of OCT in noninvasive monitoring BGC in diabetic patients. The OCT signal slope (OCTSS) changed with variation of BGC. The correlation coefficient R between BGC and OCTSS in diabetic patients was 0.91; while the correlation coefficient R in healthy volunteers was 0.78. Thus, a better linear dependence of OCTSS on BGC in diabetic patients was presented in the experiment. The results showed that the capability and accuracy of OCT in noninvasive monitoring BGC of diabetic patients, and the noninvasive monitoring BGC in diabetic patients may be better than the monitoring in the healthy subjects.

  18. A compact photometer based on metal-waveguide-capillary: application to detecting glucose of nanomolar concentration

    NASA Astrophysics Data System (ADS)

    Bai, Min; Huang, Hui; Hao, Jian; Zhang, Ji; Wu, Haibo; Qu, Bo

    2015-05-01

    Trace analysis of liquid samples has wide applications in life science and environmental monitor. In this paper, a compact and low-cost photometer based on metal-waveguide-capillary (MWC) was developed for ultra-sensitive absorbance detection. The optical-path can be greatly enhanced and much longer than the physical length of MWC, because the light scattered by the rippled and smooth metal sidewall can be confined inside the capillary regardless of the incident-angle. For the photometer with a 7 cm long MWC, the detection limit is improved ~3000 fold compared with that of commercial spectrophotometer with 1 cm-cuvette, owing to the novel nonlinear optical-path enhancement as well as fast sample switching, and detecting glucose of a concentration as low as 5.12 nM was realized with conventional chromogenic reagent.

  19. Femtosecond laser micromachining of compound parabolic concentrator fiber tipped glucose sensors

    NASA Astrophysics Data System (ADS)

    Hassan, Hafeez Ul; Lacraz, Amédée; Kalli, Kyriacos; Bang, Ole

    2017-03-01

    We report on highly accurate femtosecond (fs) laser micromachining of a compound parabolic concentrator (CPC) fiber tip on a polymer optical fiber (POF). The accuracy is reflected in an unprecedented correspondence between the numerically predicted and experimentally found improvement in fluorescence pickup efficiency of a Förster resonance energy transfer-based POF glucose sensor. A Zemax model of the CPC-tipped sensor predicts an optimal improvement of a factor of 3.96 compared to the sensor with a plane-cut fiber tip. The fs laser micromachined CPC tip showed an increase of a factor of 3.5, which is only 11.6% from the predicted value. Earlier state-of-the-art fabrication of the CPC-shaped tip by fiber tapering was of so poor quality that the actual improvement was 43% lower than the predicted improvement of the ideal CPC shape.

  20. Polymer optical fiber compound parabolic concentrator tip for enhanced coupling efficiency for fluorescence based glucose sensors.

    PubMed

    Hassan, Hafeez Ul; Nielsen, Kristian; Aasmul, Soren; Bang, Ole

    2015-12-01

    We demonstrate that the light excitation and capturing efficiency of fluorescence based fiber-optical sensors can be significantly increased by using a CPC (Compound Parabolic Concentrator) tip instead of the standard plane-cut tip. We use Zemax modelling to find the optimum CPC tip profile and fiber length of a polymer optical fiber diabetes sensor for continuous monitoring of glucose levels. We experimentally verify the improved performance of the CPC tipped sensor and the predicted production tolerances. Due to physical size requirements when the sensor has to be inserted into the body a non-optimal fiber length of 35 mm is chosen. For this length an average improvement in efficiency of a factor of 1.7 is experimentally demonstrated and critically compared to the predicted ideal factor of 3 in terms of parameters that should be improved through production optimization.

  1. Whole Genome Sequence Analysis of Pig Respiratory Bacterial Pathogens with Elevated Minimum Inhibitory Concentrations for Macrolides.

    PubMed

    Dayao, Denise Ann Estarez; Seddon, Jennifer M; Gibson, Justine S; Blackall, Patrick J; Turni, Conny

    2016-10-01

    Macrolides are often used to treat and control bacterial pathogens causing respiratory disease in pigs. This study analyzed the whole genome sequences of one clinical isolate of Actinobacillus pleuropneumoniae, Haemophilus parasuis, Pasteurella multocida, and Bordetella bronchiseptica, all isolated from Australian pigs to identify the mechanism underlying the elevated minimum inhibitory concentrations (MICs) for erythromycin, tilmicosin, or tulathromycin. The H. parasuis assembled genome had a nucleotide transition at position 2059 (A to G) in the six copies of the 23S rRNA gene. This mutation has previously been associated with macrolide resistance but this is the first reported mechanism associated with elevated macrolide MICs in H. parasuis. There was no known macrolide resistance mechanism identified in the other three bacterial genomes. However, strA and sul2, aminoglycoside and sulfonamide resistance genes, respectively, were detected in one contiguous sequence (contig 1) of A. pleuropneumoniae assembled genome. This contig was identical to plasmids previously identified in Pasteurellaceae. This study has provided one possible explanation of elevated MICs to macrolides in H. parasuis. Further studies are necessary to clarify the mechanism causing the unexplained macrolide resistance in other Australian pig respiratory pathogens including the role of efflux systems, which were detected in all analyzed genomes.

  2. Elevated synovial fluid concentration of adenosine triphosphate in dogs with osteoarthritis or sodium urate-induced synovitis of the stifle.

    PubMed

    Torres, Bryan T; Jimenez, David A; Budsberg, Steven C

    2016-07-19

    Adenosine triphosphate has been shown to stimulate nociceptive nerve terminals in joints. Elevated synovial fluid adenosine triphosphate concentrations as well as a correlation between synovial fluid adenosine triphosphate concentrations and osteoarthritic knee pain has been demonstrated in humans, but not yet in dogs. This study documented elevated synovial fluid adenosine triphosphate concentrations in the stifles of dogs with secondary osteoarthritis and urate-induced synovitis, as compared to normal stifles.

  3. Determination of glucose concentration in tissue-like material using spatially resolved steady-state diffuse reflectance spectroscopy

    NASA Astrophysics Data System (ADS)

    Hjalmarsson, Pär; Thennadil, Suresh N.

    2008-02-01

    An important parameter in medical diagnostic and one of the most frequently determined analyte in the hospitals is blood glucose. Fast and accurate methods of measuring blood glucose concentrations could therefore be significant. We will in this paper investigate the feasibility of using a spatially resolved steady-state diffuse reflectance spectroscopy in the wavelength region 1000-1700nm, where glucose has two absorption peaks at around 1250nm and 1600nm, to quickly determine the concentration of glucose in tissue-like material. This method could later be transferred to estimate the amount of glucose in blood both in vivo e.g. the forearm and in vitro e.g. on blood samples. The novel spatially resolved system that is used for this study is based around a 2D InGaAs detector and a fibre probe with 10 fibres, one as a source and 9 to collect the diffuse reflected light at distances between 0.3-2.7mm from the source. An inversion method using Monte Carlo generated diffuse reflectance profiles is used to estimate the absolute absorption coefficient (μ a) and reduced scattering coefficient (μ s') which could be used to estimate the glucose concentration in the tissue-like phantoms. The method was investigated by performing spatially resolved measurements on turbid gelatin phantoms containing mixtures of water and D IIO as absorbers, Intralipid as a scatterer and glucose. The phantoms were made with four different glucose concentrations spanning the range of 0-5000 mg/dl.

  4. The effect of nitric oxide inhibitors and Snitroso-Nacetylpenicillamine on glucose concentration in an animal model

    PubMed Central

    Bryan, Sophia; Alexander-Lindo, Ruby; Dasgupta, Tara; McGrowder, Donovan

    2011-01-01

    Background: Nitric oxide (NO) is becoming an increasingly important signaling molecule implicated in a growing number of physiological and pathophysiological processes. Research on the effect of NO donors on glucose metabolism in peripheral tissues have grown rapidly in the last decade. This study examined the effects of NGmethyl-L-arginine acetate (L-NMMA) and NGmethyl-L-arginine ester (L-NAME) on fasting and postprandial blood glucose concentrations. The study also investigated if L-NMMA and L-NAME decrease the hyperglycemic effect caused by the NO donor S-nitrosoN-acetylpenicillamine (SNAP) in normoglycemic rats. Results: L-NAME and L-NMMA significantly lowered the postprandial blood glucose concentrations. Mean postprandial blood glucose concentrations in rats treated with L-NAME were 5.04 ± 0.07 mmol/L at 120 min, 4.62 ± 0.19 mmol/L at 150 min and 4.36 ± 0.17 mmol/L at 180 min time points compared with 5.46 ± 0.14 (P = 0.029), 5.20 ± 0.17 mmol/L (P = 0.036), and 4.89 ± 0.14 mmol/L (P = 0.015) at the same time points respectively for saline control. Mean blood glucose concentrations in rats treated with L-NMMA were 4.35 ± 0.23 mmol/L (P = 0.0018) at 120 min, 4.60 ± 0.14 mmol/L (P = 0.090) at 150 min and 3.88 ± 0.16 mmol/L (P 0.001) at 180 min. There were significant differences in mean postprandial blood glucose concentrations in rats treated with SNAP, compared with those treated with L-NAME and SNAP at 90 min (P = 0.012), 180 min (P = 0.013) and 210 min (P < 0.0001). In addition, there were significant differences in mean postprandial blood glucose concentrations in rats treated with SNAP compared with those treated with L-NMMA and SNAP at 90 min (P = 0.0011), 180 min (P = 0.015) and 210 min (P = 0.0077). Conclusion: The nitric oxide synthase [NOS] inhibitors were effective in reducing postprandial blood glucose concentration in rats treated with SNAP. This suggests that although SNAP is an effective antihypertensive agent it decreases glucose

  5. Effect of elevated CO2 concentration on microalgal communities in Antarctic pack ice

    NASA Astrophysics Data System (ADS)

    Coad, Thomas; McMinn, Andrew; Nomura, Daiki; Martin, Andrew

    2016-09-01

    Increased anthropogenic CO2 emissions are causing changes to oceanic pH and CO2 concentrations that will impact many marine organisms, including microalgae. Phytoplankton taxa have shown mixed responses to these changes with some doing well while others have been adversely affected. Here, the photosynthetic response of sea-ice algal communities from Antarctic pack ice (brine and infiltration microbial communities) to a range of CO2 concentrations (400 ppm to 11,000 ppm in brine algae experiments, 400 ppm to 20,000 ppm in the infiltration ice algae experiment) was investigated. Incubations were conducted as part of the Sea-Ice Physics and Ecosystem Experiment II (SIPEX-2) voyage, in the austral spring (September-November), 2012. In the brine incubations, maximum quantum yield (Fv/Fm) and relative electron transfer rate (rETRmax) were highest at ambient and 0.049% (experiment 1) and 0.19% (experiment 2) CO2 concentrations, although, Fv/Fm was consistently between 0.53±0.10-0.68±0.01 across all treatments in both experiments. Highest rETRmax was exhibited by brine cultures exposed to ambient CO2 concentrations (60.15). In a third experiment infiltration ice algal communities were allowed to melt into seawater modified to simulate the changed pH and CO2 concentrations of future springtime ice-edge conditions. Ambient and 0.1% CO2 treatments had the highest growth rates and Fv/Fm values but only the highest CO2 concentration produced a significantly lower rETRmax. These experiments, conducted on natural Antarctic sea-ice algal communities, indicate a strong level of tolerance to elevated CO2 concentrations and suggest that these communities might not be adversely affected by predicted changes in CO2 concentration over the next century.

  6. Physiological response of Polygonum perfoliatum L. following exposure to elevated manganese concentrations.

    PubMed

    Xue, Shengguo; Wang, Jun; Wu, Chuan; Li, Song; Hartley, William; Wu, Hao; Zhu, Feng; Cui, Mengqian

    2016-12-29

    Polygonum perfoliatum L. is a Mn-tolerant plant as considered having the potential to revegetate in manganese mine wasteland. The glasshouse experiments were carried out to evaluate its tolerance and physiological response in different Mn concentrations (5, 500, 1000, 2000, 5000, and 10,000 μmol L(-1)). Absorption bands of P. perfoliatum differed greatly in lipids, proteins, and carbohydrates. With elevated levels of Mn (5-2000 μmol L(-1)), absorbance changed little, which demonstrated that lower Mn concentrations had negligible influence on transport functions. As Mn concentrations in excess of 2000 μmol L(-1), absorbance increased slightly but eventually decreased. Furthermore, a hydroponic culture was carried out in order to study its changes of ultrastructure with the increasing Mn concentrations (5, 1000, and 10,000 μmol L(-1)). Lower Mn levels with 5 and 1000 μmol L(-1) had no breakage function to the ultrastructure of P. perfoliatum. However, as Mn concentration was up to 10,000 μmol L(-1), visible damages began to appear, the quantity of mitochondria in root cells increased, and the granum lamellae of leaf cell chloroplasts presented a disordered state. In comparison with the controls, black agglomerations were found in the cells of P. perfoliatum under the controlling concentration of Mn with 1000 and 10,000 μmol L(-1) for 30 days, which became obvious at higher Mn concentrations. As Mn concentration was 10,000 μmol L(-1), a kind of new acicular substance was developed in leaf cells and intercellular spaces, possibly indicating a resistance mechanism in P. perfoliatum. These results confirm that P. perfoliatum shows potential for the revegetation of abandoned manganese tailings.

  7. Bedside monitoring of subcutaneous interstitial glucose in type 1 diabetic subjects using microdialysis and infrared spectrometry with optimal correlation to blood glucose concentrations

    NASA Astrophysics Data System (ADS)

    Heise, H. Michael; Damm, Uwe; Kondepati, Venkata R.; Mader, J. K.; Ellmerer, M.

    2007-02-01

    Infrared spectroscopy has been successfully employed in multi-component assays for the study of various biomedical samples. Two areas have found particular interest, i.e. in-vitro analysis in the clinical laboratory and point-of-care applications. With regard to the latter field, in-vivo blood glucose monitoring is an important topic for improving glycemic control in critically ill patients with non-adequate blood glucose regulation, similar to the situation faced for diabetic patients. For such application, a continuously operated mid-infrared spectroscopic system in combination with a subcutaneously implanted microdialysis probe and coupled by micro-fluidics has been developed. Using the dialysis process, the interstitial fluid matrix can be significantly simplified, since high molecular mass compounds such as proteins are separated. However, the micro-dialysis recovery rate is variable over time, so that a simultaneous determination of this parameter was implemented using the losses of an acetate marker from the perfusate across the dialysis membrane. Clinical measurements were carried out on type 1 diabetic subjects, with experiments lasting up to 28 hours. The concentrations of glucose, acetate and other components in the dialysates from interstitial body fluids were investigated. Two different multivariate calibration strategies, i.e. partial least squares (PLS) and classical least squares (CLS) regressions were applied. The results led to excellent correlation of the subcutaneous interstitial concentrations with those of laboratory blood glucose readings. Clarke-Error-Grid evaluations were employed for assessing the clinical applicability of the method.

  8. Elevations in gonadotrophin concentrations and milt volumes as a result of spawning behavior in the goldfish.

    PubMed

    Kyle, A L; Stacey, N E; Peter, R E; Billard, R

    1985-01-01

    In many male mammals and birds, exposure to sexual stimuli results in acute elevations of circulating luteinizing hormone (LH) and testosterone (T); a similar phenomemon has now been observed in the male goldfish (Carassius auratus). Mature males placed with either a receptive female or stimulus pairs of spawning goldfish had gonadotrophin (GtH) concentrations and expressible milt (sperm) volumes that were significantly greater than those of males kept in all-male groups. This stimulatory effect lasted from 20 min to at least 2 hr for GtH (20 degrees) and from less than or equal to 1 hr to greater than or equal to 24 hr for milt (14 degrees). When males were separated from the spawning pair by either a solid or perforated clear partition, no elevations of GtH or milt levels occurred. In contrast, these values increased in males placed in contact with a spawning pair, even when that pair contained no female, but a male induced to perform female sexual behavior by treatment with prostaglandin. These results suggest that, in goldfish, access to a spawning situation is necessary for rapid elevations in GtH and milt. Furthermore, it appears that the males must be sexually active in order for these physiological changes to occur, as males that failed to engage in courtship behavior with a spawning pair had GtH and milt values not different from isolated fish. This suggests that male sexual behavior and elevations in milt and GtH are concurrent events that share a common activation pathway in the brain. The increase in milt may be due to both neurally and hormonally mediated events that ensure milt availability for imminent spawning activity.

  9. Temperature insensitive prediction of glucose concentration in turbid medium using multivariable calibration based on external parameter orthogonalization

    NASA Astrophysics Data System (ADS)

    Han, Tongshuai; Zhang, Ziyang; Sun, Cuiying; Guo, Chao; Sun, Di; Liu, Jin

    2016-10-01

    The measurement accuracy of non-invasive blood glucose concentration (BGC) sensing with near-infrared spectroscopy is easily affected by the temperature variation in tissue because it would induce an unacceptable spectrum variation and the consequent prediction deviation. We use a multivariable correction method based on external parameter orthogonalization (EPO) to calibrate the spectral data recorded at different temperature values to reduce the spectral variation. The tested medium is a kind of tissue phantom, the Intralipid aqueous solution. The calibration uses a projection matrix to get the orthogonal spectral space to the variable of external parameter, i.e. temperature, and then the useful spectral information relative to glucose concentration has been reserved. Even more, training the projection matrix can be separated to building the calibration matrix for the prediction of glucose concentration as it only uses the representative samples' data with temperature variation. The method presents a lower complexity than modeling a robust prediction matrix, which can be built from comprehensive spectral data involved the all variables both of BGC and temperature. In our test, the calibrated spectra with the same glucose concentration but different temperature values show a significantly improved repeatability. And then the glucose concentration prediction results show a lower root mean squared error of prediction (RMSEP) than that using the robust calibration model, which has considered the two variables. We also discuss the rationality of the representative samples chosen by EPO. This research may be referenced to the temperature calibration for in vivo BGC sensing.

  10. Elevated atmospheric carbon dioxide concentration affects interactions between Spodoptera exigua (Lepidoptera: Noctuidae) larvae and two host plant species outdoors

    SciTech Connect

    Caulfield, F.; Bunce, J.A. )

    1994-08-01

    Beet armyworm, Spodoptera exigua (Huebner), larvae were placed on sugarbeet (Beta vulgaris L.) and pigweed (Amaranthus hybridus L.) plants in outdoor chambers in which the plants were growing at either the ambient ([approximately] 350 [mu]l liter[sup [minus]1]) or ambient plus 350 [mu]l liter[sup [minus]1] ([approximately] 700 [mu]l liter[sup [minus]1]) carbon dioxide concentration. A series of experiments was performed to determine if larvae reduced plant growth differently at the two carbon dioxide concentrations in either species and if the insect growth or survival differed with carbon dioxide concentration. Leaf nitrogen, water, starch, and soluble carbohydrate contents were measured to assess carbon dioxide concentration effects on leaf quality. Insect feeding significantly reduced plant growth in sugarbeet plants at 350 [mu]l liter[sup [minus]1] but not at 700 [mu]l liter[sup [minus]1] nor in pigweed at either carbon dioxide concentration. Larval survival was greater on sugarbeet plants at the elevated carbon dioxide concentration. Increased survival occurred only if the insects were at the elevated carbon dioxide concentration and consumed leaf material grown at the elevated concentration. Leaf quality was only marginally affected by growth at elevated carbon dioxide concentration in these experiments. The results indicate that in designing experiments to predict effects of elevated atmospheric carbon dioxide concentrations on plant-insect interactions, both plants and insects should be exposed to the experimental carbon dioxide concentrations, as well as to as realistic environmental conditions as possible.

  11. Effect of delayed serum separation and storage temperature on serum glucose concentration in horse, dog, alpaca, and sturgeon.

    PubMed

    Collicutt, Nancy B; Garner, Bridget; Berghaus, Roy D; Camus, Melinda S; Hart, Kelsey

    2015-03-01

    Although delays between blood sample collection and analysis are common in veterinary medicine, the effect of prolonged serum-clot contact time on serum glucose concentration is not well established and species differences have not been elucidated. The objective was to investigate the effect of storage time and temperature on serum glucose concentration in stored whole blood samples from horse, dog, alpaca, and sturgeon. Whole blood specimens were divided into 7 no-additive tubes and serum was separated from one sample within one hour, serving as the reference sample. The remaining samples were stored at 4°C and 25°C, then centrifuged and serum glucose measured by automated analysis at 2, 4, and 8 hours postcollection. Glucose concentrations were compared using linear mixed models. The decline in serum glucose concentration for all samples stored at 4°C was not statistically significant, except for the 8-hour samples from sturgeon and dog. At 25°C, serum glucose concentration was comparable to reference values at 2 hours in sturgeon and alpaca, but significantly lower at 4 and 8 hours in those species, and at all time points in equine and canine specimens, being most prominent after 8 hours of storage in canine specimens. Storage at 4°C limits serum glucose decline for at least 4 hours in all species tested and up to 8 hours in specimens of horse and alpaca. At 25°C, serum-clot contact time should not exceed 1 hour in equine and canine samples, and 2 hours in specimens from alpaca and sturgeon. © 2014 American Society for Veterinary Clinical Pathology.

  12. Effects of elevated temperature and CO2 concentration on photosynthesis of the alpine plants in Zoige Plateau, China

    NASA Astrophysics Data System (ADS)

    Zijuan, Zhou; Peixi, Su; Rui, Shi; Tingting, Xie

    2017-04-01

    Increasing temperature and carbon dioxide concentration are the important aspects of global climate change. Alpine ecosystem response to global change was more sensitive and rapid than other ecosystems. Increases in temperature and atmospheric CO2concentrations have strong impacts on plant physiology. Photosynthesis is the basis for plant growth and the decisive factor for the level of productivity, and also is a very sensitive physiological process to climate change. In this study, we examined the interactive effects of elevated temperature and atmospheric CO2 concentration on the light response of photosynthesis in two alpine plants Elymus nutans and Potentilla anserine, which were widely distributed in alpine meadow in the Zoige Plateau, China. We set up as follows: the control (Ta 20˚ C, CO2 380μmolṡmol-1), elevated temperature (Ta 25˚ C, CO2 380 μmolṡmol-1), elevated CO2 concentration (Ta 20˚ C, CO2 700μmolṡmol-1), elevated temperature and CO2 concentration (Ta 25˚ C, CO2 700μmolṡmol-1). The results showed that compared to P. anserine, E. nutans had a higher maximum net photosynthetic rate (Pnmax), light saturation point (LSP) and apparent quantum yield (AQY) in the control. Elevated temperature increased the Pnmaxand LSP values in P. anserine, while Pnmaxand LSP were decreased in E. nutans. Elevated CO2 increased the Pnmaxand LSP values in E. nutans and P. anserine, while the light compensation point (LCP) decreased; Elevated both temperature and CO2, the Pnmaxand LSP were all increased for E. nutans and P. anserine, but did not significantly affect AQY. We concluded that although elevated temperature had a photoinhibition for E. nutans, the interaction of short-term elevated CO2 concentration and temperature can improve the photosynthetic capacity of alpine plants. Key Words: elevated temperature; CO2 concentration; light response; alpine plants

  13. Species richness and selenium accumulation of plants in soils with elevated concentration of selenium and salinity

    SciTech Connect

    Huang, Z.Z.; Wu, L. )

    1991-12-01

    Field studies were conducted in soils with elevated concentrations of Se and salinity at Kesterson, California. Biomass distribution, species richness, and selenium accumulation of plants were examined for two sites where 15 cm of surface soil was removed and replaced with fill dirt in the fall of 1989, and two sites were native soil cover. The Se concentrations in the top 15 cm of fill dirt ranged from undetectable to 36 ng g-1. For the native soil sites, Se levels ranged from 75 to 550 ng g-1. Soil Se concentrations below 15 cm ranged from 300 to 700 ng g-1 and were comparable between the fill dirt and the native soil sites. At least 20 different plant species were brought into the two fill dirt sites with the top soil. Avena fatua L., Bassia hyssopifolia Kuntze Rev. Gen. Pl., Centaurea solstitialis L., Erysimum officianale L., Franseria acanthicarpa Cav. Icon., and Melilotus indica (L.) All. contributed over 60% of the total biomass. Only 5 species were found in the native soil sites, and salt grass (Distichlis spicata L.) was the predominant species and accounted for over 80% of the total biomass. Between 1989 and 1990, two years after the surface soil replacement, the two fill dirt sites had a 70% reduction in species richness. Plant tissue selenium concentrations were found to be quite variable between plant species and between sites of sampling. At the fill dirt sites, the plant species with deep root systems accumulated greater amounts of selenium than the shallow-rooted species. The soil selenium concentration of the field soil had no negative effect on pollen fertility, seed set, and seed germination for the plant species examined. However, seedling growth was impaired by the soil selenium concentrations. This suggests that a selection pressure of soil Se concentration may have been imposed on plant species such as M. indica in an early stage of its life cycle.

  14. Acute ACTH-induced elevations of circulating cortisol do not affect hair cortisol concentrations in calves.

    PubMed

    Tallo-Parra, O; Lopez-Bejar, M; Carbajal, A; Monclús, L; Manteca, X; Devant, M

    2017-01-01

    In recent times, the detection of cortisol in hair is intended to be used as an animal-based indicator for the assessment of chronic stress. However, the relationship between the ability to report average values of long-term circulating cortisol concentrations and the sensitivity to acute peaks of cortisol is still unclear. To gain insight into this relationship, 24 Holstein-Friesian bull calves under the same management conditions were used in this study. Two injections of ACTH (at D0 and D7) were administrated to twelve animals with the aim to create two acute increases of serum cortisol concentrations. Blood samples were taken in order to determine the duration of serum cortisol peaks and to confirm a mediated response by the administration of ACTH. Cortisol concentrations from 14-day-old white hair samples collected from forehead and hip were analysed separately by EIA and compared with those from the control group. Serum cortisol analyses revealed an acute increase of cortisol concentrations for approximately three hours after each ACTH administration. Concentrations of hair cortisol from forehead and hip locations showed no differences between ACTH-administrated and control animals. Hair cortisol concentrations from 14-day old samples were not altered by two acute elevations of serum cortisol suggesting that hair cortisol is not masked by short and non-recurrent moments of stress. These results are a step forward in the validation of hair cortisol detection as a robust integrative measure of serum cortisol concentrations from an extended period of time. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Elevated Lung Cancer in Younger Adults and Low Concentrations of Arsenic in Water

    PubMed Central

    Steinmaus, Craig; Ferreccio, Catterina; Yuan, Yan; Acevedo, Johanna; González, Francisca; Perez, Liliana; Cortés, Sandra; Balmes, John R.; Liaw, Jane; Smith, Allan H.

    2014-01-01

    Arsenic concentrations greater than 100 µg/L in drinking water are a known cause of cancer, but the risks associated with lower concentrations are less well understood. The unusual geology and good information on past exposure found in northern Chile are key advantages for investigating the potential long-term effects of arsenic. We performed a case-control study of lung cancer from 2007 to 2010 in areas of northern Chile that had a wide range of arsenic concentrations in drinking water. Previously, we reported evidence of elevated cancer risks at arsenic concentrations greater than 100 µg/L. In the present study, we restricted analyses to the 92 cases and 288 population-based controls who were exposed to concentrations less than 100 µg/L. After adjustment for age, sex, and smoking behavior, these exposures from 40 or more years ago resulted in odds ratios for lung cancer of 1.00, 1.43 (90% confidence interval: 0.82, 2.52), and 2.01 (90% confidence interval: 1.14, 3.52) for increasing tertiles of arsenic exposure, respectively (P for trend = 0.02). Mean arsenic water concentrations in these tertiles were 6.5, 23.0, and 58.6 µg/L. For subjects younger than 65 years of age, the corresponding odds ratios were 1.00, 1.62 (90% confidence interval: 0.67, 3.90), and 3.41 (90% confidence interval: 1.51, 7.70). Adjustments for occupation, fruit and vegetable intake, and socioeconomic status had little impact on the results. These findings provide new evidence that arsenic water concentrations less than 100 µg/L are associated with higher risks of lung cancer. PMID:25371173

  16. Elevated lung cancer in younger adults and low concentrations of arsenic in water.

    PubMed

    Steinmaus, Craig; Ferreccio, Catterina; Yuan, Yan; Acevedo, Johanna; González, Francisca; Perez, Liliana; Cortés, Sandra; Balmes, John R; Liaw, Jane; Smith, Allan H

    2014-12-01

    Arsenic concentrations greater than 100 µg/L in drinking water are a known cause of cancer, but the risks associated with lower concentrations are less well understood. The unusual geology and good information on past exposure found in northern Chile are key advantages for investigating the potential long-term effects of arsenic. We performed a case-control study of lung cancer from 2007 to 2010 in areas of northern Chile that had a wide range of arsenic concentrations in drinking water. Previously, we reported evidence of elevated cancer risks at arsenic concentrations greater than 100 µg/L. In the present study, we restricted analyses to the 92 cases and 288 population-based controls who were exposed to concentrations less than 100 µg/L. After adjustment for age, sex, and smoking behavior, these exposures from 40 or more years ago resulted in odds ratios for lung cancer of 1.00, 1.43 (90% confidence interval: 0.82, 2.52), and 2.01 (90% confidence interval: 1.14, 3.52) for increasing tertiles of arsenic exposure, respectively (P for trend = 0.02). Mean arsenic water concentrations in these tertiles were 6.5, 23.0, and 58.6 µg/L. For subjects younger than 65 years of age, the corresponding odds ratios were 1.00, 1.62 (90% confidence interval: 0.67, 3.90), and 3.41 (90% confidence interval: 1.51, 7.70). Adjustments for occupation, fruit and vegetable intake, and socioeconomic status had little impact on the results. These findings provide new evidence that arsenic water concentrations less than 100 µg/L are associated with higher risks of lung cancer. © The Author 2014. Published by Oxford University Press on behalf of the Johns Hopkins Bloomberg School of Public Health. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. Organic phosphorus mineralisation in a temperate grassland soil under elevated atmospheric carbon dioxide concentrations

    NASA Astrophysics Data System (ADS)

    Jarosch, Klaus A.; Andresen, Louise; Gorenflo, André D.; Müller, Christoph; Frossard, Emmanuel; Bünemann, Else K.

    2016-04-01

    Background: Phosphorus (P) is an essential nutrient for all biota and significant proportions of P in soil are present in organic form. Increased atmospheric concentrations of carbon dioxide ([CO2]) have been shown to influence plant P uptake traits, resulting in plant-mediated changes in soil P pools. However, little is known on the effect of elevated [CO2] on organic P mineralisation rates in soil. Study design & hypotheses: A 33P isotopic dilution experiment was performed with soils of the 17-year-old Giessen free air carbon dioxide enrichment (GiFACE) - trial. At the GiFACE, three plots are treated with 20 % elevated [CO2] while three control plots receive ambient air. We hypothesised that i) the observed positive effect of elevated [CO2] on plant growth translates into differences in soil organic P mineralisation rates between treated and untreated plots, resulting in ii) differences in soil organic P pools. Methods: Fresh soil (0-8 cm) was sampled from each plot, labelled with a carrier free 33P solution and incubated for 36 days at 19° C in the dark. On six time points, inorganic P and 33P in soil filtrates, soil microorganisms (by liquid fumigation) and resin extractable P were quantified. The baseline of 33P isotopic dilution was assessed from a short term batch experiment and extrapolated for 36 days. Gross organic P mineralisation rates were determined as the difference between isotopic dilution in the incubated soils (physicochemical + biological processes) minus extrapolated values (physicochemical processes only). Additionally, enzyme addition assays on alkaline soil extracts were performed to quantify different soil organic P classes, using enzymes with a known substrate specificity. Results & Discussion: Gross organic P mineralisation rates were high during the first three days (5.5 - 34.3 mg P kg-1 d-1), possibly due to the soil disturbance at labelling soils with 33P. However, gross organic P mineralisation decreased rapidly to rates between 0

  18. Elevated extracellular glucose and uncontrolled type 1 diabetes enhance NFAT5 signaling and disrupt the transverse tubular network in mouse skeletal muscle

    PubMed Central

    Hernández-Ochoa, Erick O; Robison, Patrick; Contreras, Minerva; Shen, Tiansheng; Zhao, Zhiyong; Schneider, Martin F

    2012-01-01

    The transcription factor nuclear factor of activated T-cells 5 (NFAT5) is a key protector from hypertonic stress in the kidney, but its role in skeletal muscle is unexamined. Here, we evaluate the effects of glucose hypertonicity and hyperglycemia on endogenous NFAT5 activity, transverse tubular system morphology and Ca2+ signaling in adult murine skeletal muscle fibers. We found that exposure to elevated glucose (25–50 mmol/L) increased NFAT5 expression and nuclear translocation, and NFAT-driven transcriptional activity. These effects were insensitive to the inhibition of calcineurin A, but sensitive to both p38a mitogen-activated protein kinases and phosphoinositide 3-kinase-related kinase inhibition. Fibers exposed to elevated glucose exhibited disrupted transverse tubular morphology, characterized by swollen transverse tubules and an increase in longitudinal connections between adjacent transverse tubules. Ca2+ transients elicited by a single, brief electric field stimuli were increased in amplitude in fibers challenged by elevated glucose. Muscle fibers from type 1 diabetic mice exhibited increased NFAT5 expression and transverse tubule disruptions, but no differences in electrically evoked Ca2+ transients. Our results suggest the hypothesis that these changes in skeletal muscle could play a role in the pathophysiology of acute and severe hyperglycemic episodes commonly observed in uncontrolled diabetes. PMID:22966145

  19. Fibroblast growth factor 21, assisted by elevated glucose, activates paraventricular nucleus NUCB2/Nesfatin-1 neurons to produce satiety under fed states

    PubMed Central

    Santoso, Putra; Nakata, Masanori; Shiizaki, Kazuhiro; Boyang, Zhang; Parmila, Kumari; Otgon-Uul, Zesemdorj; Hashimoto, Koshi; Satoh, Tetsurou; Mori, Masatomo; Kuro-o, Makoto; Yada, Toshihiko

    2017-01-01

    Fibroblast growth factor 21 (FGF21), liver-derived hormone, exerts diverse metabolic effects, being considered for clinical application to treat obesity and diabetes. However, its anorexigenic effect is debatable and whether it involves the central mechanism remains unclarified. Moreover, the neuron mediating FGF21’s anorexigenic effect and the systemic energy state supporting it are unclear. We explored the target neuron and fed/fasted state dependence of FGF21’s anorexigenic action. Intracerebroventricular (ICV) injection of FGF21 markedly suppressed food intake in fed mice with elevated blood glucose. FGF21 induced c-Fos expression preferentially in hypothalamic paraventricular nucleus (PVN), and increased mRNA expression selectively for nucleobindin 2/nesfatin-1 (NUCB2/Nesf-1). FGF21 at elevated glucose increased [Ca2+]i in PVN NUCB2/Nesf-1 neurons. FGF21 failed to suppress food intake in PVN-preferential Sim1-Nucb2-KO mice. These findings reveal that FGF21, assisted by elevated glucose, activates PVN NUCB2/Nesf-1 neurons to suppress feeding under fed states, serving as the glycemia-monitoring messenger of liver-hypothalamic network for integrative regulation of energy and glucose metabolism. PMID:28374855

  20. Elevated glucocorticoid concentrations during gestation predict reduced reproductive success in subordinate female banded mongooses.

    PubMed

    Sanderson, J L; Nichols, H J; Marshall, H H; Vitikainen, E I K; Thompson, F J; Walker, S L; Cant, M A; Young, A J

    2015-10-01

    Dominant females in social species have been hypothesized to reduce the reproductive success of their subordinates by inducing elevated circulating glucocorticoid (GC) concentrations. However, this 'stress-related suppression' hypothesis has received little support in cooperatively breeding species, despite evident reproductive skews among females. We tested this hypothesis in the banded mongoose (Mungos mungo), a cooperative mammal in which multiple females conceive and carry to term in each communal breeding attempt. As predicted, lower ranked females had lower reproductive success, even among females that carried to term. While there were no rank-related differences in faecal glucocorticoid (fGC) concentrations prior to gestation or in the first trimester, lower ranked females had significantly higher fGC concentrations than higher ranked females in the second and third trimesters. Finally, females with higher fGC concentrations during the third trimester lost a greater proportion of their gestated young prior to their emergence from the burrow. Together, our results are consistent with a role for rank-related maternal stress in generating reproductive skew among females in this cooperative breeder. While studies of reproductive skew frequently consider the possibility that rank-related stress reduces the conception rates of subordinates, our findings highlight the possibility of detrimental effects on reproductive outcomes even after pregnancies have become established.

  1. Elevated glucocorticoid concentrations during gestation predict reduced reproductive success in subordinate female banded mongooses

    PubMed Central

    Sanderson, J. L.; Nichols, H. J.; Marshall, H. H.; Vitikainen, E. I. K.; Thompson, F. J.; Walker, S. L.; Cant, M. A.; Young, A. J.

    2015-01-01

    Dominant females in social species have been hypothesized to reduce the reproductive success of their subordinates by inducing elevated circulating glucocorticoid (GC) concentrations. However, this ‘stress-related suppression' hypothesis has received little support in cooperatively breeding species, despite evident reproductive skews among females. We tested this hypothesis in the banded mongoose (Mungos mungo), a cooperative mammal in which multiple females conceive and carry to term in each communal breeding attempt. As predicted, lower ranked females had lower reproductive success, even among females that carried to term. While there were no rank-related differences in faecal glucocorticoid (fGC) concentrations prior to gestation or in the first trimester, lower ranked females had significantly higher fGC concentrations than higher ranked females in the second and third trimesters. Finally, females with higher fGC concentrations during the third trimester lost a greater proportion of their gestated young prior to their emergence from the burrow. Together, our results are consistent with a role for rank-related maternal stress in generating reproductive skew among females in this cooperative breeder. While studies of reproductive skew frequently consider the possibility that rank-related stress reduces the conception rates of subordinates, our findings highlight the possibility of detrimental effects on reproductive outcomes even after pregnancies have become established. PMID:26510673

  2. Elevated cerebrospinal fluid neopterin concentration is associated with disease severity in acute Puumala hantavirus infection.

    PubMed

    Hautala, Timo; Partanen, Terhi; Sironen, Tarja; Rajaniemi, Saara-Mari; Hautala, Nina; Vainio, Olli; Vapalahti, Olli; Kauma, Heikki; Vaheri, Antti

    2013-01-01

    Nephropathia epidemica (NE) caused by Puumala hantavirus (PUUV) is the most common hemorrhagic fever with renal syndrome (HFRS) in Europe. The infection activates immunological mechanisms that contribute to the pathogenesis and characteristics of the illness. In this study we measured cerebrospinal fluid (CSF) neopterin concentration from 23 acute-phase NE patients. We collected data on kidney function, markers of tissue permeability, haemodynamic properties, blood cell count, length of hospitalisation, inflammatory parameters, and ophthalmological properties. The neopterin levels were elevated (> 5.8 nmol/L) in 22 (96%) NE-patients (mean 45.8 nmol/L); these were especially high in patients with intrathecal PUUV-IgM production (mean 58.2 nmol/L, P = 0.01) and those with elevated CSF protein concentrations (mean 63.6 nmol/L, P < 0.05). We also observed a correlation between the neopterin and high plasma creatinine value (r = 0.66, P = 0.001), low blood thrombocyte count (r = -0.42, P < 0.05), and markedly disturbed refractory properties of an eye (r = 0.47, P < 0.05). Length of hospitalisation correlated with the neopterin (r = 0.42, P < 0.05; male patients r = 0.69, P < 0.01). Patients with signs of tissue oedema and increased permeability also had high neopterin concentrations. These results reinforce the view that PUUV-HFRS is a general infection that affects the central nervous system and the blood-brain barrier.

  3. Elevated Cerebrospinal Fluid Neopterin Concentration Is Associated with Disease Severity in Acute Puumala Hantavirus Infection

    PubMed Central

    Hautala, Timo; Partanen, Terhi; Sironen, Tarja; Rajaniemi, Saara-Mari; Hautala, Nina; Vainio, Olli; Vapalahti, Olli; Kauma, Heikki; Vaheri, Antti

    2013-01-01

    Nephropathia epidemica (NE) caused by Puumala hantavirus (PUUV) is the most common hemorrhagic fever with renal syndrome (HFRS) in Europe. The infection activates immunological mechanisms that contribute to the pathogenesis and characteristics of the illness. In this study we measured cerebrospinal fluid (CSF) neopterin concentration from 23 acute-phase NE patients. We collected data on kidney function, markers of tissue permeability, haemodynamic properties, blood cell count, length of hospitalisation, inflammatory parameters, and ophthalmological properties. The neopterin levels were elevated (>5.8 nmol/L) in 22 (96%) NE-patients (mean 45.8 nmol/L); these were especially high in patients with intrathecal PUUV-IgM production (mean 58.2 nmol/L, P = 0.01) and those with elevated CSF protein concentrations (mean 63.6 nmol/L, P < 0.05). We also observed a correlation between the neopterin and high plasma creatinine value (r = 0.66, P = 0.001), low blood thrombocyte count (r = −0.42, P < 0.05), and markedly disturbed refractory properties of an eye (r = 0.47, P < 0.05). Length of hospitalisation correlated with the neopterin (r = 0.42, P < 0.05; male patients r = 0.69, P < 0.01). Patients with signs of tissue oedema and increased permeability also had high neopterin concentrations. These results reinforce the view that PUUV-HFRS is a general infection that affects the central nervous system and the blood-brain barrier. PMID:23983770

  4. Elevated Manganese Concentrations in Drinking Water May Be Beneficial for Fetal Survival

    PubMed Central

    Rahman, Syed Moshfiqur; Åkesson, Agneta; Kippler, Maria; Grandér, Margaretha; Hamadani, Jena Derakhshani; Streatfield, Peter Kim; Persson, Lars-Åke; Arifeen, Shams El; Vahter, Marie

    2013-01-01

    Background Elevated exposure to the essential element manganese (Mn) can be toxic. Manganese concentrations in ground water vary considerably, and reported associations between Mn and early-life mortality and impaired development have raised concern. We assessed the effects of drinking water Mn exposure during pregnancy upon fetal and infant survival. Methods In this population-based cohort study, we identified the outcomes of pregnancies registered between February 2002 and April 2003 in Matlab, Bangladesh. Using inductively coupled plasma mass spectrometry, we measured the concentrations of Mn and other elements in the pregnant women’s drinking water. Results A total of 1,875 women were included in the analysis of spontaneous abortions (n=158) and 1,887 women in the perinatal mortality analysis (n=70). Water Mn ranged from 3.0–6,550 µg/L (median=217 µg/L). The adjusted odds ratio (OR) for spontaneous abortion was 0.65 (95% CI 0.43–0.99) in the highest water Mn tertile (median=1,292 µg/L) as compared to the lowest tertile (median=56 µg/L). The corresponding OR for perinatal mortality was 0.69 (95% CI 0.28–1.71), which increased to 0.78 (95% CI 0.29–2.08) after adjustment for BMI and place of delivery (home/health facility; n=1,648). Conclusions Elevated water Mn concentrations during pregnancy appear protective for the fetus, particularly in undernourished women. This effect may be due to the element’s role in antioxidant defense. PMID:24066101

  5. A high isoflavone diet decreases 5' adenosine monophosphate-activated protein kinase activation and does not correct selenium-induced elevations in fasting blood glucose in mice.

    PubMed

    Stallings, Michael T; Cardon, Brandon R; Hardman, Jeremy M; Bliss, Tyler A; Brunson, Scott E; Hart, Chris M; Swiss, Maria D; Hepworth, Squire D; Christensen, Merrill J; Hancock, Chad R

    2014-04-01

    Selenium (Se) has been implicated as a micronutrient that decreases adenosine monophosphate-activated protein kinase (AMPK) signaling and may increase diabetes risk by reducing insulin sensitivity. Soy isoflavones (IF) are estrogen-like compounds that have been shown to attenuate insulin resistance, hyperglycemia, adiposity, and increased AMPK activation. We hypothesized that a high IF (HIF) diet would prevent the poor metabolic profile associated with high Se intake. The purpose of this study was to examine changes in basal glucose metabolism and AMPK signaling in response to an HIF diet and/or supplemental Se in a mouse model. Male FVB mice were divided into groups receiving either a control diet with minimal IF (low IF) or an HIF diet. Each dietary group was further subdivided into groups receiving either water or Se at a dose of 3 mg Se/kg body weight daily, as Se-methylselenocysteine (SMSC). After 5 months, mice receiving SMSC had elevated fasting glucose (P < .05) and a tendency for glucose intolerance (P = .08). The increase in dietary IF did not result in improved fasting blood glucose. Interestingly, after 6 months, HIF-fed mice had decreased basal AMPK activation in liver and skeletal muscle tissue (P < .05). Basal glucose metabolism was changed by SMSC supplementation as evidenced by increased fasting blood glucose and glucose intolerance. High dietary IF levels did not protect against aberrant blood glucose. In FVB mice, decreased basal AMPK activation is not the mechanism through which Se exerts its effect. These results suggest that more research must be done to elucidate the role of Se and IF in glucose metabolism.

  6. Potential ecotoxicological significance of elevated concentrations of strontium in eggshells of passerine birds

    USGS Publications Warehouse

    Mora, Miguel A.; Taylor, Robert J.; Brattin, Bryan L.

    2007-01-01

    We investigated the occurrence and potential ecotoxicological significance of elevated concentrations of strontium (Sr) in eggshells of nine passerine birds from four regions in Arizona. Concentrations of Sr in eggshells ranged from 70 to 1360 µg g−1 dry weight (overall mean  =  684 ± 345 SD µg g−1 dw) for the four regions. 23% of the eggshells had Sr concentrations greater than 1000 µg g−1 dw. To our knowledge, these are among the highest levels of Sr that have been reported in bird eggshells in North America. Of the nine species, Brown-headed Cowbirds (Molothrus ater) had the greatest concentrations of Sr. There was a significant positive correlation between Sr and calcium (Ca), and between barium (Ba) and Ca. Ca, Sr, and Ba interact with each other and can exert similar chemical and pharmacological effects. Mean (n ≥ 3) eggshell∶egg ratios for Sr varied with species and ranged from 6.1∶1 to 40.2∶1; ratios for individual eggs reached 92.7∶1. Mean Sr/Ca values ranged from 1.3 × 10−3 to 3.0 × 10−3 and mean eggshell thickness ranged from 83 ± 6 to 120 ± 9 µm for all species. Eggshell thickness was not significantly correlated with Sr for any species but tended to increase with Sr concentrations. We postulate that high concentrations of Sr in the shell could affect later-stage embryos by possible interference with Ca metabolism and bone growth, resulting in reduced hatching success and potential minor beak deformities.

  7. Portal vein and systemic adiponectin concentrations are closely linked with hepatic glucose and lipoprotein kinetics in extremely obese subjects.

    PubMed

    Magkos, Faidon; Fabbrini, Elisa; Patterson, Bruce W; Eagon, J Christopher; Klein, Samuel

    2011-11-01

    Low systemic plasma adiponectin concentrations are associated with abnormalities in hepatic glucose and lipoprotein metabolism in obese people. However, the relationship between the delivery of adiponectin to the liver via the portal vein and hepatic glucose and lipoprotein metabolism is not known. We examined the relationship between hepatic substrate metabolism (glucose rate of appearance into plasma and hepatic very low-density lipoprotein [VLDL]-triglyceride [TG] and VLDL-apolipoprotein B-100 [apoB-100] secretion rates, determined by using stable isotope-labeled tracer techniques) and portal vein adiponectin concentration, in 8 insulin-resistant, extremely obese subjects (body mass index, 65 ± 7 kg/m(2)). Portal vein adiponectin concentration was inversely associated with basal glucose rate of appearance (r = -0.820, P = .013) and VLDL-TG (r = -0.823, P = .012) and VLDL-apoB-100 (r = -0.787, P = .020) secretion rates. Very similar correlations were obtained for radial artery adiponectin as a result of a mirroring relationship between portal and arterial adiponectin concentrations (r = 0.899, P = .002) and the absence of significant arteriovenous concentration differences (P = .570). Insulin resistance, assessed with the homeostasis model assessment score, was also strongly associated with hepatic glucose and lipid metabolic parameters, as well as with adiponectin concentrations in the portal vein and radial artery. These results suggest that adiponectin delivery to the liver, whether via the portal or the systemic circulation, may be an important regulator of basal hepatic glucose, VLDL-TG, and VLDL-apoB-100 production rates in obese people, possibly through direct effects on the liver or changes in hepatic insulin sensitivity. However, portal vein adiponectin does not appear to be superior to arterial adiponectin as a marker of hepatic metabolic dysregulation. Additional studies are needed to elucidate the mechanism(s) responsible for the strong association

  8. Evaluation of three point-of-care meters and a portable veterinary chemistry analyzer for measurement of blood glucose concentrations in black-tailed prairie dogs (Cynomys ludovicianus).

    PubMed

    Higbie, Christine T; Eshar, David; Bello, Nora M

    2015-06-01

    To compare blood glucose concentrations of black-tailed prairie dogs (Cynomys ludovicianus) measured by use of a variety of portable analyzers with results from a laboratory biochemistry analyzer. Venous blood samples (3 mL) obtained from each of 16 healthy black-tailed prairie dogs. A portion of each blood sample was used to measure glucose concentrations by use of an amperometric human point-of-care glucometer and a colorimetric species-specific portable blood glucose meter designed for veterinary use with both canine (code 5) and feline (code 7) settings. The remainder of each blood sample was placed into 2 tubes (one contained lithium heparin and the other contained no anticoagulant). A portable veterinary chemistry analyzer (PVCA) and a handheld analyzer were used to measure glucose concentration in heparinized blood. Serum glucose concentration was measured in the remaining portion by use of a biochemistry analyzer. A general linear mixed models approach was used to compare glucose concentrations and measurement bias obtained with the various measurement methods. Measurement bias and differences in mean glucose concentrations were apparent with all measurement methods. In particular, the veterinary glucometer, whether used on the canine or feline setting, overestimated mean glucose concentrations, whereas the human glucometer, PVCA, and handheld analyzer underestimated mean glucose concentrations relative to the concentration obtained with the biochemistry analyzer. Results indicated that none of the measurement methods provided consistently accurate blood glucose concentrations of black-tailed prairie dogs, compared with values determined with a biochemistry analyzer.

  9. Glucose, fructose and sucrose increase the solubility of protein-tannin complexes and at high concentration, glucose and sucrose interfere with bisulphite bleaching of wine pigments.

    PubMed

    Harbertson, James F; Yuan, Chunlong; Mireles, Maria S; Hanlin, Rachel L; Downey, Mark O

    2013-05-01

    Wines were modified with increasing sugar concentrations and decreasing tannin concentrations and analysed by a combination of protein precipitation and bisulphite bleaching. Increasing sugar concentration decreased the precipitation of tannin and protein-precipitable polymeric pigments (PPP). The use of a hydrogen bond disruptor (urea) to reduce protein-tannin and protein-pigment complex formation showed that the effect of sugar concentration occurred by increasing the solubility of the tannin-protein complex, not by interfering with protein-tannin complex formation. By increasing the solubility of pigment-protein complexes, non-protein-precipitable polymeric pigments (nPPP) appeared to increase. There was also an increase in total polymeric pigments at each tannin concentration with increasing glucose and sucrose concentration, indicating that sugar concentration might also affect bisulphite bleaching of wine pigments. While a significant effect of sugar concentration on tannin-protein complex solubility was observed, these effects were greatest at sugar concentrations far in excess of normal wine making conditions. Under normal wine making conditions, sugar concentration will have a negligible effect on protein-precipitable tannin, PPP and nPPP concentrations.

  10. Photoacoustic spectroscopy that uses a resonant characteristic of a microphone for in vitro measurements of glucose concentration.

    PubMed

    Joo Yong Sim; Chang-Geun Ahn; Eunju Jeong; Bong Kyu Kim

    2016-08-01

    Glucose measurements using photoacoustic spectroscopy have been highlighted to be a modality for non-invasive glucose monitoring. Previous photoacoustic spectroscopy for glucose measurements have used a resonant acoustic cell with a broadband capacitive microphone to increase sensitivity. However, a resonant characteristic of a microphone has not been investigated yet due to the working frequency range much lower than the resonance frequency of the microphone membrane. We, here, present a photoacoustic spectroscopy system that utilizes an ultrasound resonance of a microphone to increase sensitivity. We found that matching the resonance of a photoacoustic cell with the resonance of a microphone can increase signal-to-noise ratio and our system can distinguish the glucose concentration in liquid.

  11. Blood and urine responses to ingesting fluids of various salt and glucose concentrations. [to combat orthostatic intolerance

    NASA Technical Reports Server (NTRS)

    Frey, Mary A.; Riddle, Jeanne; Charles, John B.; Bungo, Michael W.

    1991-01-01

    To compensate for the reduced blood and fluid volumes that develop during weightlessness, the Space Shuttle crewmembers consume salt tablets and water equivalent to 1 l of normal saline, about 2 hrs before landing. This paper compares the effects on blood, urine, and cardiovascular variables of the ingestion of 1 l of normal (0.9 percent) saline with the effects of distilled water, 1 percent glucose, 0.74 percent saline with 1 percent glucose, 0.9 percent saline with 1 percent glucose, and 1.07 percent saline. It was found that the expansion of plasma volume and the concentration of urine were greater 4 hrs after ingestion of 1.07 percent saline solution than after ingestion of normal saline and that the solutions containig glucose did not enhance any variables as compared with normal saline.

  12. Blood and urine responses to ingesting fluids of various salt and glucose concentrations. [to combat orthostatic intolerance

    NASA Technical Reports Server (NTRS)

    Frey, Mary A.; Riddle, Jeanne; Charles, John B.; Bungo, Michael W.

    1991-01-01

    To compensate for the reduced blood and fluid volumes that develop during weightlessness, the Space Shuttle crewmembers consume salt tablets and water equivalent to 1 l of normal saline, about 2 hrs before landing. This paper compares the effects on blood, urine, and cardiovascular variables of the ingestion of 1 l of normal (0.9 percent) saline with the effects of distilled water, 1 percent glucose, 0.74 percent saline with 1 percent glucose, 0.9 percent saline with 1 percent glucose, and 1.07 percent saline. It was found that the expansion of plasma volume and the concentration of urine were greater 4 hrs after ingestion of 1.07 percent saline solution than after ingestion of normal saline and that the solutions containig glucose did not enhance any variables as compared with normal saline.

  13. Impaired glucose tolerance and elevated blood pressure in low birth weight, nonobese, young south african adults: early programming of cortisol axis.

    PubMed

    Levitt, N S; Lambert, E V; Woods, D; Hales, C N; Andrew, R; Seckl, J R

    2000-12-01

    Low birth weight is associated with increased cardiovascular and metabolic disorders in adult life, although the mechanisms of this effect remain uncertain. There is one report of increased morning plasma cortisol levels in an elderly low birth weight cohort, but whether this is primary or secondary to other aspects of the phenotype is unclear. We investigated the association between low birth weight and glucose intolerance, blood pressure, and dyslipidemia in young, nonobese adults from a community undergoing the health transition with a high prevalence of both noncommunicable diseases and low birth weight. Additionally, we investigated whether altered basal and stimulated cortisol levels as a marker of hypothalamic-pituitary-adrenal responsiveness or cortisol metabolism were associated with low birth weight in these young adults. Twenty-year-old, historically disadvantaged, urbanized South Africans (n = 137) with birth weights either below the 10th percentile [underweight for age (UFA)] or between the 25th and 75th percentiles [appropriate for gestational age (AFA)] had anthropometry, blood pressure, lipid levels, and glucose tolerance measured. In a subset (n = 62), 0900 h plasma cortisol concentrations, cortisol responses to 1 microg ACTH, and urinary glucocorticoid metabolites were measured. The mothers of UFA infants were themselves lighter and had a lower body mass index (P: = 0. 0016). At age 20 yr, although the UFA group was still smaller and lighter, with a lower body mass index, they had higher fasting plasma glucose levels (P: = 0.047), and a greater proportion demonstrated glucose intolerance (11.9% vs. 0%; P: < 0.01). The UFA group also had higher systolic [UFA, 126.0 +/- 13.3 (+/-SD); AFA, 122.0 +/- 11.7 mm Hg; P: = 0.007] and diastolic (72.3 +/- 8.4 vs. 69. 5 +/- 8.7 mm Hg; P: = 0.02) blood pressures, after covarying for current weight and gender. Plasma cortisol levels determined at 0900 h were higher in the UFA group (484.9 +/- 166.3 vs. 418

  14. The economic burden of elevated blood glucose levels in 2012: diagnosed and undiagnosed diabetes, gestational diabetes mellitus, and prediabetes.

    PubMed

    Dall, Timothy M; Yang, Wenya; Halder, Pragna; Pang, Bo; Massoudi, Marjan; Wintfeld, Neil; Semilla, April P; Franz, Jerry; Hogan, Paul F

    2014-12-01

    To update estimates of the economic burden of undiagnosed diabetes, prediabetes, and gestational diabetes mellitus in 2012 in the U.S. and to present state-level estimates. Combined with published estimates for diagnosed diabetes, these statistics provide a detailed picture of the economic costs associated with elevated glucose levels. This study estimated health care use and medical expenditures in excess of expected levels occurring in the absence of diabetes or prediabetes. Data sources that were analyzed include Optum medical claims for ∼4.9 million commercially insured patients who were continuously enrolled from 2010 to 2012, Medicare Standard Analytical Files containing medical claims for ∼2.6 million Medicare patients in 2011, and the 2010 Nationwide Inpatient Sample containing ∼7.8 million hospital discharge records. The indirect economic burden includes reduced labor force participation, missed workdays, and reduced productivity. State-level estimates reflect geographic variation in prevalence, risk factors, and prices. The economic burden associated with diagnosed diabetes (all ages) and undiagnosed diabetes, gestational diabetes, and prediabetes (adults) exceeded $322 billion in 2012, consisting of $244 billion in excess medical costs and $78 billion in reduced productivity. Combined, this amounts to an economic burden exceeding $1,000 for each American in 2012. This national estimate is 48% higher than the $218 billion estimate for 2007. The burden per case averaged $10,970 for diagnosed diabetes, $5,800 for gestational diabetes, $4,030 for undiagnosed diabetes, and $510 for prediabetes. These statistics underscore the importance of finding ways to reduce the burden of prediabetes and diabetes through prevention and treatment. © 2014 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  15. Responses of mature loblolly pine trees to elevated CO[sub 2] concentrations

    SciTech Connect

    Lie, S.; Teskey, R.O. )

    1993-06-01

    The direct responses of mature loblolly pine (Pinus taeda) foliage to increasing atmospheric CO[sub 2] were investigated in six 18-year-old loblolly pine trees using the branch-chamber technique. On each tree, six main branches were randomly selected and each enclosed in one of six chambers. Each branch received one of the following six treatments: ambient CO[sub 2]/ambient temperature (1), 1.5 x ambient CO[sub 2] ambient temperature (2), 2.0 x ambient CO[sub 2]/ambient temperature (3), ambient CO[sub 2]/2.0[degrees]C + ambient temperature (4), 1.5 x ambient CO[sub 2]/2.0[degree]C + ambient temperature (5) and 2.0 x ambient CO[sub 2]/2.0[degree]C + ambient temperature (6). A/C, curves were run and P- (photosynthetic rate at saturating light) of the current year, first flush needles was measured at each respective treatment CO[sub 2] level for treatments 1, 2 and 3 using the Li-cor 6200 photosynthesis system. Both elevated CO[sub 2] concentrations significantly increased the photosynthesis of the foliage of the mature loblolly pine trees. However, comparison of the slopes of the initial linear part of the A/C[sub 1], curves suggested no reduction in the rubisco carboxylation activity. Additionally, there was no indication of photosynthetic acclimation to elevated CO[sub 2].

  16. Effects of long-term elevated atmospheric CO{sub 2} concentrations on Pinus ponderosa

    SciTech Connect

    Surano, K.A.; Kercher, J.R.

    1993-10-01

    This report details the results from an experiment of the effects of long-term elevated atmospheric CO{sub 2} concentrations on ponderosa pine (Pinus ponderosa Laws.) saplings and seedlings. The study began in 1983 as a pilot study designed to explore the feasibility of using open-top chambers for continuous multi-year exposures on sapling-sized trees and to examine possible CO{sub 2} responses so that future research could be adequately designed. however, following the first year of exposure, preliminary results from the study indicated that measurements of CO{sub 2} responses should be intensified. Open-top chambers proved suitable for use in multiyear exposures of mature trees. With respect to the preliminary examination of CO{sub 2} responses, many interesting observations were made. The nature of the preliminary results suggests that future long-term field CO{sub 2} exposures on perennial species may be critical to the understanding and preparation for future environments. Other research reported here attempted to adapt an existing western coniferous forest growth and succession model for use in elevated CO{sub 2} scenarios using differential species responses, and assessed the usefulness of the model in that regard. Seven papers have been processed separately for inclusion in the appropriate data bases.

  17. Changes in root architecture under elevated concentrations of CO₂ and nitrogen reflect alternate soil exploration strategies.

    PubMed

    Beidler, Katilyn V; Taylor, Benton N; Strand, Allan E; Cooper, Emily R; Schönholz, Marcos; Pritchard, Seth G

    2015-02-01

    Predicting the response of fine roots to increased atmospheric CO₂ concentration has important implications for carbon (C) and nutrient cycling in forest ecosystems. Root architecture is known to play an important role in how trees acquire soil resources in changing environments. However, the effects of elevated CO₂ on the fine-root architecture of trees remain unclear. We investigated the architectural response of fine roots exposed to 14 yr of CO₂ enrichment and 6 yr of nitrogen (N) fertilization in a Pinus taeda (loblolly pine) forest. Root traits reflecting geometry, topology and uptake function were measured on intact fine-root branches removed from soil monoliths and the litter layer. CO₂ enrichment resulted in the development of a fine-root pool that was less dichotomous and more exploratory under N-limited conditions. The per cent mycorrhizal colonization did not differ among treatments, suggesting that root growth and acclimation to elevated CO₂ were quantitatively more important than increased mycorrhizal associations. Our findings emphasize the importance of architectural plasticity in response to environmental change and suggest that changes in root architecture may allow trees to effectively exploit larger volumes of soil, thereby pre-empting progressive nutrient limitations. © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.

  18. Observations of the uptake of carbonyl sulfide (COS) by trees under elevated atmospheric carbon dioxide concentrations

    NASA Astrophysics Data System (ADS)

    Sandoval-Soto, L.; Kesselmeier, M.; Schmitt, V.; Wild, A.; Kesselmeier, J.

    2012-02-01

    Global change affects ecosystems to adapt to elevated atmospheric concentrations of carbon dioxide (CO2). We understand that carbonyl sulfide (COS), a trace gas which is involved in building up the stratospheric sulfate aerosol layer, is taken up by vegetation with the same triad of the enzmyes which are metabolizing the CO2, i.e. Ribulose-1,5-bisphosphate Carboxylase-Oxygenase (Rubisco), Phosphoenolpyruvate Carboxylase (PEP-Co) and carbonic anhydrase (CA). Therefore, we discuss a physiological/biochemical adaptation of these enzymes to affect the sink strength of vegetation for COS. We investigated the adaption of two European tree species, Fagus sylvatica and Quercus ilex, grown inside chambers under elevated CO2 and determined the exchange characteristics and the content of CA after a 1-2 yr period of adaption from 350 ppm to 800 ppm CO2. We could demonstrate that the COS compensation point, the CA activity and the deposition velocities may change and cause a decrease of the COS uptake by plant ecosystems. As a consequence, the atmospheric COS level may rise leading to higher input of this trace gas into the stratosphere and causing a higher energy reflection by the stratospheric sulfur aerosol into space, thus counteracting the direct radiative forcing by the tropospheric COS.

  19. Positive Feedback Amplifies the Response of Mitochondrial Membrane Potential to Glucose Concentration in Clonal Pancreatic Beta Cells.

    PubMed

    Gerencser, Akos A; Mookerjee, Shona A; Jastroch, Martin; Brand, Martin D

    2016-10-20

    Analysis of the cellular mechanisms of metabolic disorders, including type 2 diabetes mellitus, is complicated by the large number of reactions and interactions in metabolic networks. Metabolic control analysis with appropriate modularization is a powerful method for simplifying and analyzing these networks. To analyze control of cellular energy metabolism in adherent cell cultures of the INS-1 832/13 pancreatic β-cell model we adapted our microscopy assay of absolute mitochondrial membrane potential (ΔψM) to a fluorescence microplate reader format, and applied it in conjunction with cell respirometry. In these cells the sensitive response of ΔψM to extracellular glucose concentration drives glucose-stimulated insulin secretion. Using metabolic control analysis we identified the control properties that generate this sensitive response. Force-flux relationships between ΔψM and respiration were used to calculate kinetic responses to ΔψM of processes both upstream (glucose oxidation) and downstream (proton leak and ATP turnover) of ΔψM. The analysis revealed that glucose-evoked ΔψM hyperpolarization is amplified by increased glucose oxidation activity caused by factors downstream of ΔψM. At high glucose, the hyperpolarized ΔψM is stabilized almost completely by the action of glucose oxidation, whereas proton leak also contributes to the homeostatic control of ΔψM at low glucose. These findings suggest a strong positive feedback loop in the regulation of β-cell energetics, and a possible regulatory role of proton leak in the fasting state. Analysis of islet bioenergetics from published cases of type 2 diabetes suggests that disruption of this feedback can explain the damaged bioenergetic response of β-cells to glucose.

  20. Evaluation of the relationship between elevated vancomycin trough concentrations and increased efficacy and/or toxicity.

    PubMed

    Ackerman, Bruce H; Guilday, Robert E; Reigart, Cynthia L; Patton, Mary L; Haith, Linwood R

    2013-01-01

    Isolation of Staphylococcus aureus with minimum inhibitory concentrations, 1 to 2 mg/L, suggests increasing vancomycin trough ranges, from 10 to 20 mg/L or even higher. Vancomycin troughs from 604 treatment courses from 560 patients with suspected or actual Gram-positive infection were analyzed with focus on potential toxicity/efficacy. Trough concentrations were required to be drawn within 15 to 45 minutes before the administration of at least the third vancomycin dose. Patients were retrospectively evaluated for their total daily dose and milligrams per kilograms per vancomycin dose. Data on the duration of vancomycin therapy, days to a normal temperature, and white blood cells were obtained. Data were stratified by trough concentration as <5, 5 to 10, and >10 mg/L to determine whether there was any relationship between response and trough concentration. Demographic data were obtained in 560 patients with 604 vancomycin treatment courses. For 361 patients with 379 separate treatment courses of vancomycin therapy no other nephrotoxic antimicrobial agent had been used. The greatest risk of vancomycin nephrotoxicity correlated with the duration of treatment. Using the log time to normal temperature, white blood cell count, heart rate, outcome from vancomycin therapy was assessed and no relationship could be demonstrated for the three vancomycin trough strata using analysis of variance (F < 2.62 for all parameters; p > .05). These data indicate that vancomycin trough elevation may not guarantee treatment success and that there may be no real benefit from higher vancomycin trough concentrations in thermal injury patients with burns <20% TBSA.

  1. Aggregate structure, morphology and the effect of aggregation mechanisms on viscosity at elevated protein concentrations.

    PubMed

    Barnett, Gregory V; Qi, Wei; Amin, Samiul; Neil Lewis, E; Roberts, Christopher J

    2015-12-01

    Non-native aggregation is a common issue in a number of degenerative diseases and during manufacturing of protein-based therapeutics. There is a growing interest to monitor protein stability at intermediate to high protein concentrations, which are required for therapeutic dosing of subcutaneous injections. An understanding of the impact of protein structural changes and interactions on the protein aggregation mechanisms and resulting aggregate size and morphology may lead to improved strategies to reduce aggregation and solution viscosity. This report investigates non-native aggregation of a model protein, α-chymotrypsinogen, under accelerated conditions at elevated protein concentrations. Far-UV circular dichroism and Raman scattering show structural changes during aggregation. Size exclusion chromatography and laser light scattering are used to monitor the progression of aggregate growth and monomer loss. Monomer loss is concomitant with increased β-sheet structures as monomers are added to aggregates, which illustrate a transition from a native monomeric state to an aggregate state. Aggregates grow predominantly through monomer-addition, resulting in a semi-flexible polymer morphology. Analysis of aggregation growth kinetics shows that pH strongly affects the characteristic timescales for nucleation (τn) and growth (τg), while the initial protein concentration has only minor effects on τn or τg. Low-shear viscosity measurements follow a common scaling relationship between average aggregate molecular weight (Mw(agg)) and concentration (σ), which is consistent with semi-dilute polymer-solution theory. The results establish a link between aggregate growth mechanisms, which couple Mw(agg) and σ, to increases in solution viscosity even at these intermediate protein concentrations (less than 3w/v %).

  2. Elevated morphine concentrations determined during infant death investigations: artifacts of withdrawal of care.

    PubMed

    Watterson, James; Peaire, Amy; Hinman, Justin

    2008-07-01

    Three cases are reported of elevated postmortem blood morphine concentrations (189-3036 ng/mL) that were observed during the course of death investigations involving three children ranging in age from 1 week to 2 years, all of whom underwent withdrawal of life support. In all three cases, the presence of opiates in postmortem blood was indicated by immunoassay (ELISA) and quantitative confirmatory analysis of free morphine concentrations in postmortem blood was performed by solid-phase extraction followed by gas chromatography/mass spectrometry (GC/MS) in the selected ion monitoring mode. While the practice of withdrawing life support from terminally ill patients, with the accompanying administration of narcotics/analgesics has been reported in the medical literature, it has not been adequately described in the forensic literature. The implications of this practice on the forensic toxicological interpretation of morphine findings are discussed. To our knowledge, this is the first report of postmortem morphine concentrations arising directly from administration in conjunction with withdrawal of care in pediatric patients.

  3. Effect of elevated carbon dioxide concentration on carbon assimilation under fluctuating light.

    PubMed

    Holišová, Petra; Zitová, Martina; Klem, Karel; Urban, Otmar

    2012-01-01

    Natural fluctuations in light intensity may significantly affect the amount of CO assimilated by plants and ecosystems. Little is known, however, about the interactive effect of dynamic light conditions and atmospheric CO concentrations. The hypothesis that elevated CO concentration (EC; 700 μmol CO mol) increases photosynthetic efficiency in dynamic light environments as compared to ambient CO concentration (AC; 385 μmol CO mol) was tested. Sun leaves of European beech ( L.) and current-year shoots of Norway spruce [ (L). Karst.] were exposed to five dynamic light regimes (LRs) occurring within forest canopies due to variable cloud cover or self-shading of leaves and to a steady-state LR. The LRs differed in the time course of incident irradiance, whereas the overall duration (600 s) and total amount of radiation (35.88 mmol photons m) were the same in all LRs. The EC treatment enhanced the amount of CO assimilated under all LRs tested. While the stimulation was only 37 to 50% in beech, it was 52 to 85% in spruce. The hypothesis that photosynthetic efficiency is stimulated by EC was confirmed in LRs when the leaves were pre-exposed to low light intensity and photosynthetic induction was required. By contrast, only a minor effect of EC treatment was found on the rate of induction loss and postillumination CO fixation in both species studied.

  4. Relationships between body weight, fasting blood glucose concentration, sex and age in tree shrews (Tupaia belangeri chinensis).

    PubMed

    Wu, X; Chang, Q; Zhang, Y; Zou, X; Chen, L; Zhang, L; Lv, L; Liang, B

    2013-12-01

    The tree shrew (Tupaia belangeri chinensis) is a squirrel-like lower primate or a close relative of primates, commonly used as an animal model in biomedical research. Despite more than three decades of usage in research, the clear relationships between body weight, fasting blood glucose concentration, sex and age among tree shrews remain unclear. Based on an investigation of 992 tree shrews (454 males and 538 females) aged between 4 months and 4 years old, we found that male tree shrews have significantly higher body weight and fasting blood glucose concentration than female tree shrews (p < 0.001). The concentration of fasting blood glucose slightly increased with body weight in males (r = 0.152, p < 0.001). Meanwhile, in females, the body weight, concentration of fasting blood glucose and waist circumference positively increased with age (p < 0.001). Additionally, 17 tree shrews with Lee index [body weight (g)*0.33*1000/body length (cm)] above 290 had significantly higher body weight, waist circumference and glycated haemoglobin A1c (HbA1c) than non-obese tree shrews with a Lee index score below 290 (p < 0.001). Interestingly, 6 of 992 tree shrews (three males and three females, 2-4 years old) displayed impaired plasma triglycerides, HbA1c, low-density lipoprotein and oral glucose tolerance test, suggestive of the early symptoms of metabolic syndrome. This study provides the first clear relationships between body weight, fasting blood glucose concentration, sex and age in tree shrews, further improving our understanding of this relationship in metabolic syndrome (MetS). Given the similarity of tree shrews to humans and non-human primates, this finding supports their potential use as an animal model in the research of MetS.

  5. Evaluation of short-term predictors of glucose concentration in type 1 diabetes combining feature ranking with regression models.

    PubMed

    Georga, Eleni I; Protopappas, Vasilios C; Polyzos, Demosthenes; Fotiadis, Dimitrios I

    2015-12-01

    Glucose concentration in type 1 diabetes is a function of biological and environmental factors which present high inter-patient variability. The objective of this study is to evaluate a number of features, which are extracted from medical and lifestyle self-monitoring data, with respect to their ability to predict the short-term subcutaneous (s.c.) glucose concentration of an individual. Random forests (RF) and RReliefF algorithms are first employed to rank the candidate feature set. Then, a forward selection procedure follows to build a glucose predictive model, where features are sequentially added to it in decreasing order of importance. Predictions are performed using support vector regression or Gaussian processes. The proposed method is validated on a dataset of 15 type diabetics in real-life conditions. The s.c. glucose profile along with time of the day and plasma insulin concentration are systematically highly ranked, while the effect of food intake and physical activity varies considerably among patients. Moreover, the average prediction error converges in less than d/2 iterations (d is the number of features). Our results suggest that RF and RReliefF can find the most informative features and can be successfully used to customize the input of glucose models.

  6. Gas diffusion electrode setup for catalyst testing in concentrated phosphoric acid at elevated temperatures.

    PubMed

    Wiberg, Gustav K H; Fleige, Michael; Arenz, Matthias

    2015-02-01

    We present a detailed description of the construction and testing of an electrochemical cell setup allowing the investigation of a gas diffusion electrode containing carbon supported high surface area catalysts. The setup is designed for measurements in concentrated phosphoric acid at elevated temperature, i.e., very close to the actual conditions in high temperature proton exchange membrane fuel cells (HT-PEMFCs). The cell consists of a stainless steel flow field and a PEEK plastic cell body comprising the electrochemical cell, which exhibits a three electrode configuration. The cell body and flow field are braced using a KF-25 vacuum flange clamp, which allows an easy assembly of the setup. As demonstrated, the setup can be used to investigate temperature dependent electrochemical processes on high surface area type electrocatalysts, but it also enables quick screening tests of HT-PEMFC catalysts under realistic conditions.

  7. Gas diffusion electrode setup for catalyst testing in concentrated phosphoric acid at elevated temperatures

    SciTech Connect

    Wiberg, Gustav K. H. E-mail: m.arenz@chem.ku.dk; Fleige, Michael; Arenz, Matthias E-mail: m.arenz@chem.ku.dk

    2015-02-15

    We present a detailed description of the construction and testing of an electrochemical cell setup allowing the investigation of a gas diffusion electrode containing carbon supported high surface area catalysts. The setup is designed for measurements in concentrated phosphoric acid at elevated temperature, i.e., very close to the actual conditions in high temperature proton exchange membrane fuel cells (HT-PEMFCs). The cell consists of a stainless steel flow field and a PEEK plastic cell body comprising the electrochemical cell, which exhibits a three electrode configuration. The cell body and flow field are braced using a KF-25 vacuum flange clamp, which allows an easy assembly of the setup. As demonstrated, the setup can be used to investigate temperature dependent electrochemical processes on high surface area type electrocatalysts, but it also enables quick screening tests of HT-PEMFC catalysts under realistic conditions.

  8. Gas diffusion electrode setup for catalyst testing in concentrated phosphoric acid at elevated temperatures

    NASA Astrophysics Data System (ADS)

    Wiberg, Gustav K. H.; Fleige, Michael; Arenz, Matthias

    2015-02-01

    We present a detailed description of the construction and testing of an electrochemical cell setup allowing the investigation of a gas diffusion electrode containing carbon supported high surface area catalysts. The setup is designed for measurements in concentrated phosphoric acid at elevated temperature, i.e., very close to the actual conditions in high temperature proton exchange membrane fuel cells (HT-PEMFCs). The cell consists of a stainless steel flow field and a PEEK plastic cell body comprising the electrochemical cell, which exhibits a three electrode configuration. The cell body and flow field are braced using a KF-25 vacuum flange clamp, which allows an easy assembly of the setup. As demonstrated, the setup can be used to investigate temperature dependent electrochemical processes on high surface area type electrocatalysts, but it also enables quick screening tests of HT-PEMFC catalysts under realistic conditions.

  9. Supplementation of cheonggukjang and red ginseng cheonggukjang can improve plasma lipid profile and fasting blood glucose concentration in subjects with impaired fasting glucose.

    PubMed

    Shin, Su-Kyung; Kwon, Joong-Ho; Jeong, Yong-Jin; Jeon, Seon-Min; Choi, Ji-Young; Choi, Myung-Sook

    2011-01-01

    This study was conducted to investigate the plasma lipid profile and blood glucose-lowering effects of cheonggukjang (CH) and red ginseng CH (RGCH) in 45 subjects (men:women = 27:18; mean age, 44.9 ± 3.1 years) with impaired fasting glucose (IFG). Subjects were randomly divided into three groups: control (starch, 2 g/day), CH (20 g/day), and RGCH (20 g/day). Each volunteer received his or her daily doses for 8 weeks. The supplementation with CH and RGCH significantly decreased the plasma total cholesterol about 30.0 mg/mL and 37.7 mg/mL, respectively, compared to the initial value. The plasma low-density lipoprotein-cholesterol concentration was also significantly reduced by 29.66% and 23.42% in the CH and RGCH groups, respectively, compared to the initial value. The concentration of plasma non-high-density lipoprotein-cholesterol (107.9 mg/mL) was significantly lowered in the RGCH group compared to the initial value (139.1 mg/mL). The level of erythrocyte thiobarbituric acid-reactive substances was significantly lowered in the CH (6.5 nmol/mL) and RGCH (6.6 nmol/mL) groups compared to the initial value (7.9 nmol/mL and 8.0 nmol/mL, respectively). The ratio of apolipoprotein B and apolipoprotein A-1 concentrations (2.5) was significantly reduced in the CH group compared to the initial value (3.0). The concentration of fasting blood glucose (FBG) was significantly lower in the CH- and RGCH-supplemented groups compared to the initial value. These results suggest that CH and RGCH can lower the FBG concentration and improve the plasma lipid profile in subjects with IFG.

  10. Elevated Homocysteine Concentrations Decrease the Antihypertensive Effect of Angiotensin-Converting Enzyme Inhibitors in Hypertensive Patients.

    PubMed

    Qin, Xianhui; Li, Youbao; Sun, Ningling; Wang, Hong; Zhang, Yan; Wang, Jiguang; Li, Jianping; Xu, Xin; Liang, Min; Nie, Jing; Wang, Binyan; Cheng, Xiaoshu; Li, Nanfang; Sun, Yingxian; Zhao, Lianyou; Wang, Xiaobin; Hou, Fan Fan; Huo, Yong

    2017-01-01

    We aimed to examine whether baseline homocysteine (Hcy) concentrations affect antihypertensive responses to enalapril treatment among previously untreated hypertensive patients (n=10 783) in the CSPPT (China Stroke Primary Prevention Trial). After a 3-week run-in treatment with a daily dose of 10 mg enalapril, eligible hypertensive patients were randomly assigned to a double-blind daily treatment of a tablet of either enalapril (10 mg) and folic acid (0.8 mg) or enalapril (10 mg) alone for a median of 4.5 years. After the 3-week treatment period with enalapril alone, the systolic blood pressure-lowering effect was significantly reduced by 1.39 (95% confidence interval 0.40-2.37) and 3.25 (95% confidence interval 1.98-4.52) mm Hg, respectively, in those with baseline Hcy concentrations of 10 to 15 and ≥15 μmol/L (P for trend <0.001) as compared with those with Hcy concentration of <10 μmol/L. Similar results were observed after a 15-week treatment period with enalapril alone. After a median 4.5-year enalapril-based antihypertensive treatment period, compared with those with Hcy concentration of <10 μmol/L, the systolic blood pressure-lowering effect was still significantly reduced by 0.77 (95% confidence interval 0.01-1.53) and 1.70 (95% confidence interval 0.72-2.68) mm Hg, respectively, in those with Hcy concentrations of 10 to 15 and ≥15 μmol/L (P for trend <0.001). In addition, participants with higher baseline Hcy concentrations had persistently higher systolic blood pressure levels across the entire study treatment period. Similarly, baseline Hcy concentrations were inversely associated with diastolic blood pressure reduction during the short-term enalapril alone treatment. However, the inverse association between baseline Hcy and diastolic blood pressure reduction was attenuated and became insignificant after the long-term enalapril-based treatment period. Elevated Hcy concentrations significantly decreased the antihypertensive effect of the

  11. Serum thyroid hormone, insulin, glucose, triglycerides and protein concentrations in normal horses: association with topical dexamethasone usage.

    PubMed

    Abraham, Getu; Allersmeier, Maren; Schusser, Gerald F; Ungemach, Fritz R

    2011-06-01

    The aim of this study was to determine if topical application of dexamethasone affected the serum concentrations of thyroid hormones (triiodothyronine T(3) and thyroxine T(4)), glucose, triglycerides, total protein and insulin in normal horses. Ten horses were treated twice daily for 10 days with 50 g dexamethasone using an ointment formulation. Thyroid hormones and insulin were assayed using standard radioimmunoassay methods, while glucose, triglycerides and total protein were determined using a standard enzymatic method and the Biuret reaction, respectively. An increase in serum glucose and triglyceride concentrations was accompanied by 2-6-fold increases in serum insulin concentrations, but there was no change in serum total protein concentration. Insulin secretion increased with concomitant hyperglycemia and hypertriglyceridemia. A non-significant decline in T(4) secretion was noted. Serum T(3) and T(4) concentrations declined continuously below baseline values from 48 h. Glucose and insulin levels returned to baseline values 3 days after treatment withdrawal, whereas triglycerides reverted to baseline by 7 days. In contrast, baseline values of serum T(3) and T(4) were not reached by 20 days following drug withdrawal. The results indicated that topical administration of dexamethasone affected thyroid function and physiological metabolic functions, which may have implications for potential doping cases in racing horses.

  12. Responses of Saccharomyces cerevisiae Strains from Different Origins to Elevated Iron Concentrations

    PubMed Central

    Martínez-Garay, Carlos Andrés; de Llanos, Rosa; Romero, Antonia María; Martínez-Pastor, María Teresa

    2016-01-01

    Iron is an essential micronutrient for all eukaryotic organisms. However, the low solubility of ferric iron has tremendously increased the prevalence of iron deficiency anemia, especially in women and children, with dramatic consequences. Baker's yeast Saccharomyces cerevisiae is used as a model eukaryotic organism, a fermentative microorganism, and a feed supplement. In this report, we explore the genetic diversity of 123 wild and domestic strains of S. cerevisiae isolated from different geographical origins and sources to characterize how yeast cells respond to elevated iron concentrations in the environment. By using two different forms of iron, we selected and characterized both iron-sensitive and iron-resistant yeast strains. We observed that when the iron concentration in the medium increases, iron-sensitive strains accumulate iron more rapidly than iron-resistant isolates. We observed that, consistent with excess iron leading to oxidative stress, the redox state of iron-sensitive strains was more oxidized than that of iron-resistant strains. Growth assays in the presence of different oxidative reagents ruled out that this phenotype was due to alterations in the general oxidative stress protection machinery. It was noteworthy that iron-resistant strains were more sensitive to iron deficiency conditions than iron-sensitive strains, which suggests that adaptation to either high or low iron is detrimental for the opposite condition. An initial gene expression analysis suggested that alterations in iron homeostasis genes could contribute to the different responses of distant iron-sensitive and iron-resistant yeast strains to elevated environmental iron levels. PMID:26773083

  13. Effects of Elevated Circulating Cortisol Concentrations on Maternal Behavior in Common Marmoset Monkeys (Callithrix jacchus)

    PubMed Central

    Saltzman, Wendy; Abbott, David H.

    2009-01-01

    Summary Both acute and chronic stress can impair maternal behavior and increase rates of infant abuse in several species. The mechanisms inducing these effects are unknown, but experimental manipulation of circulating corticosterone levels alters maternal behavior in rats, and circulating or excreted cortisol concentrations have been found to correlate either positively or negatively with maternal behavior in humans and nonhuman primates. In this study, therefore, we experimentally tested the hypothesis that both acute and chronic treatment with exogenous glucocorticoids would alter maternal behavior in a primate, the common marmoset (Callithrix jacchus). Multiparous females, approximately 3−5 weeks postpartum, received daily injections of either cortisol (hydrocortisone sodium succinate and hydrocortisone acetate; N = 7) or vehicle (N = 7) for 8 days, and maternal behavior was characterized under baseline conditions as well as during exposure to a noise stressor. Cortisol treatment successfully elevated both morning and afternoon plasma cortisol concentrations and suppressed circulating levels of adrenocorticotropic hormone. In home-cage observations, cortisol-treated females carried their infants significantly less than control mothers, and in noise-stressor tests, several hours after the first cortisol or vehicle treatment, cortisol-treated mothers inspected their infants significantly more often than controls. Aggression towards infants was infrequent and mild, and did not differ between treatment groups. These findings provide the first experimental evidence that cortisol elevations can alter maternal behavior in primates. As these effects were limited in scope, however, they suggest that other stress-responsive hormones or neuropeptides may additionally play a role in mediating the effects of stress on maternal behavior. PMID:19362777

  14. Elevated plasma corticosterone concentrations influence the onset of rigor mortis and meat color in broilers.

    PubMed

    Kannan, G; Heath, J L; Wabeck, C J; Owens, S L; Mench, J A

    1998-02-01

    This experiment was conducted to determine the effect of elevated plasma corticosterone (CORT) levels on meat quality characteristics. Male broilers (Arbor Acres) were either 1) fed a diet containing corticosterone (CORT) prior to processing, 2) transported by truck for 3 h before processing, or 3) processed without either of the above treatments. Six crates of birds (10 birds per crate; two crates per treatment) were stunned or killed using CO2 gas. Six birds per crate were processed and blood samples were collected during exsanguination for plasma CORT analysis. Meat samples were collected from carcasses either at 20 min or at 4 h post-mortem. At each sampling time (ST), Pectoralis superficialis samples were collected and either individually quick frozen (IQF) in liquid nitrogen or aged on ice (AOI) for 24 h prior to pH, ratio of inosine to adenosine nucleotides (R-value), cooking loss, shear value, and color analyses. The IQF Biceps femoris samples were used for pH, R-value, color, and heme pigment analysis. Mean (+/- SEM) CORT concentrations were 12.9+/-2.57, 11.7+/-1.38 and 7.9+/-0.79 ng/mL, respectively, in the CORT, transported, and control groups. There were significant treatment by ST (P < 0.05) and ST (P < 0.001) effects on the R-value of IQF P. superficialis samples. The CORT group had the highest L* value (P < 0.01) and the lowest a* value (P < 0.06). There was also a significant main effect of ST on shear values (P < 0.05) of AOI P. superficialis samples, with the means higher at 4 h than at 20 min post-mortem. The R-value of IQF B. femoris samples was markedly influenced by treatment (P < 0.001) and ST (P < 0.001). The results indicate that artificially elevating circulating CORT concentrations results in lighter meat color in broilers.

  15. Infusion of fluoxetine, a serotonin reuptake inhibitor, in the shell region of the nucleus accumbens increases blood glucose concentrations in rats.

    PubMed

    Diepenbroek, C; Rijnsburger, M; Eggels, L; van Megen, K M; Ackermans, M T; Fliers, E; Kalsbeek, A; Serlie, M J; la Fleur, S E

    2017-01-10

    The brain is well known to regulate blood glucose, and the hypothalamus and hindbrain, in particular, have been studied extensively to understand the underlying mechanisms. Nuclei in these regions respond to alterations in blood glucose concentrations and can alter glucose liver output or glucose tissue uptake to maintain blood glucose concentrations within strict boundaries. Interestingly, several cortico-limbic regions also respond to alterations in glucose concentrations and have been shown to project to hypothalamic nuclei and glucoregulatory organs. For instance, electrical stimulation of the shell of the nucleus accumbens (sNAc) results in increased circulating concentrations of glucose and glucagon and activation of the lateral hypothalamus (LH). Whether this is caused by the simultaneous increase in serotonin release in the sNAc remains to be determined. To study the effect of sNAc serotonin on systemic glucose metabolism, we implanted bilateral microdialysis probes in the sNAc of male Wistar rats and infused fluoxetine, a serotonin reuptake inhibitor, or vehicle after which blood glucose, endogenous glucose production (EGP) and glucoregulatory hormones were measured. Fluoxetine in the sNAc for 1h significantly increased blood glucose concentrations without an effect on glucoregulatory hormones. This increase was accompanied by a higher EGP in the fluoxetine infused rats compared to the controls. These data provide further evidence for a role of sNAc-serotonin in the regulation of glucose metabolism.

  16. Free fatty acids or high-concentration glucose enhances hepatitis A virus replication in association with a reduction in glucose-regulated protein 78 expression.

    PubMed

    Nwe Win, Nan; Kanda, Tatsuo; Nakamura, Masato; Nakamoto, Shingo; Okamoto, Hiroaki; Yokosuka, Osamu; Shirasawa, Hiroshi

    2017-01-29

    Although the interaction between host and hepatitis A virus (HAV) factors could lead to severe hepatitis A, the exact mechanism of acute liver failure caused by HAV infection is not yet fully understood. The effects of metabolic diseases such as dyslipidemia or diabetes mellitus on HAV replication are still unknown. Here, we examined the effects of free fatty acids or high-concentration glucose on HAV replication and the effects on mitogen-activated protein kinase signaling pathway-related genes in human hepatocytes. We discovered a novel effect of free fatty acids or high-concentration glucose on HAV replication in association with a reduction in the expression of glucose-regulated protein 78 (GRP78). We also observed that thapsigargin induced GRP78 expression and inhibited HAV replication. These findings may provide a new interpretation of the relationship between metabolic diseases and severity of hepatitis A and suggest a new understanding of the mechanism of severe HAV infection. Copyright © 2016 Elsevier Inc. All rights reserved.

  17. Growth at elevated ozone or elevated carbon dioxide concentration alters antioxidant capacity and response to acute oxidative stress in soybean (Glycine max)

    SciTech Connect

    Gillespie, K.M.; Rogers, A.; Ainsworth, E. A.

    2011-01-31

    Soybeans (Glycine max Merr.) were grown at elevated carbon dioxide concentration ([CO{sub 2}]) or chronic elevated ozone concentration ([O{sub 3}]; 90 ppb), and then exposed to an acute O{sub 3} stress (200 ppb for 4 h) in order to test the hypothesis that the atmospheric environment alters the total antioxidant capacity of plants, and their capacity to respond to an acute oxidative stress. Total antioxidant metabolism, antioxidant enzyme activity, and antioxidant transcript abundance were characterized before, immediately after, and during recovery from the acute O{sub 3} treatment. Growth at chronic elevated [O{sub 3}] increased the total antioxidant capacity of plants, while growth at elevated [CO{sub 2}] decreased the total antioxidant capacity. Changes in total antioxidant capacity were matched by changes in ascorbate content, but not phenolic content. The growth environment significantly altered the pattern of antioxidant transcript and enzyme response to the acute O{sub 3} stress. Following the acute oxidative stress, there was an immediate transcriptional reprogramming that allowed for maintained or increased antioxidant enzyme activities in plants grown at elevated [O{sub 3}]. Growth at elevated [CO{sub 2}] appeared to increase the response of antioxidant enzymes to acute oxidative stress, but dampened and delayed the transcriptional response. These results provide evidence that the growth environment alters the antioxidant system, the immediate response to an acute oxidative stress, and the timing over which plants return to initial antioxidant levels. The results also indicate that future elevated [CO{sub 2}] and [O{sub 3}] will differentially affect the antioxidant system.

  18. Effects of elevated atmospheric CO2 concentrations, clipping regimen and differential day/night atmospheric warming on tissue nitrogen concentrations of a perennial pasture grass.

    PubMed

    Volder, Astrid; Gifford, Roger M; Evans, John R

    2015-08-13

    Forecasting the effects of climate change on nitrogen (N) cycling in pastures requires an understanding of changes in tissue N. We examined the effects of elevated atmospheric CO2 concentration, atmospheric warming and simulated grazing (clipping frequency) on aboveground and belowground tissue N concentrations and C : N ratios of a C3 pasture grass. Phalaris aquatica L. cv. 'Holdfast' was grown in the field in six transparent temperature gradient tunnels (18 × 1.5 × 1.5 m each), three at ambient atmospheric CO2 and three at 759 p.p.m. CO2. Within each tunnel, there were three air temperature treatments: ambient control, +2.2/+4.0 °C above ambient day/night warming and +3.0 °C continuous warming. A frequent and an infrequent clipping treatment were applied to each warming × CO2 combination. Green leaf N concentrations were decreased by elevated CO2 and increased by more frequent clipping. Both warming treatments increased leaf N concentrations under ambient CO2 concentrations, but did not significantly alter leaf N concentrations under elevated CO2 concentrations. Nitrogen resorption from leaves was decreased under elevated CO2 conditions as well as by more frequent clipping. Fine root N concentrations decreased strongly with increasing soil depth and were further decreased at the 10-60 cm soil depths by elevated CO2 concentrations. The interaction between the CO2 and warming treatments showed that leaf N concentration was affected in a non-additive manner. Changes in leaf C : N ratios were driven by changes in N concentration. Overall, the effects of CO2, warming and clipping treatments on aboveground tissue N concentrations were much greater than on belowground tissue.

  19. Effects of elevated atmospheric CO2 concentrations, clipping regimen and differential day/night atmospheric warming on tissue nitrogen concentrations of a perennial pasture grass

    PubMed Central

    Volder, Astrid; Gifford, Roger M.; Evans, John R.

    2015-01-01

    Forecasting the effects of climate change on nitrogen (N) cycling in pastures requires an understanding of changes in tissue N. We examined the effects of elevated atmospheric CO2 concentration, atmospheric warming and simulated grazing (clipping frequency) on aboveground and belowground tissue N concentrations and C : N ratios of a C3 pasture grass. Phalaris aquatica L. cv. ‘Holdfast’ was grown in the field in six transparent temperature gradient tunnels (18 × 1.5 × 1.5 m each), three at ambient atmospheric CO2 and three at 759 p.p.m. CO2. Within each tunnel, there were three air temperature treatments: ambient control, +2.2/+4.0 °C above ambient day/night warming and +3.0 °C continuous warming. A frequent and an infrequent clipping treatment were applied to each warming × CO2 combination. Green leaf N concentrations were decreased by elevated CO2 and increased by more frequent clipping. Both warming treatments increased leaf N concentrations under ambient CO2 concentrations, but did not significantly alter leaf N concentrations under elevated CO2 concentrations. Nitrogen resorption from leaves was decreased under elevated CO2 conditions as well as by more frequent clipping. Fine root N concentrations decreased strongly with increasing soil depth and were further decreased at the 10–60 cm soil depths by elevated CO2 concentrations. The interaction between the CO2 and warming treatments showed that leaf N concentration was affected in a non-additive manner. Changes in leaf C : N ratios were driven by changes in N concentration. Overall, the effects of CO2, warming and clipping treatments on aboveground tissue N concentrations were much greater than on belowground tissue. PMID:26272874

  20. Impact of admission blood glucose on outcomes of nondiabetic patients with acute ST-elevation myocardial infarction (from the German Acute Coronary Syndromes [ACOS] Registry).

    PubMed

    Naber, Christoph K; Mehta, Rajendra H; Jünger, Claus; Zeymer, Uwe; Wienbergen, Harm; Sabin, Georg V; Erbel, Raimund; Senges, Jochen; Gitt, Anselm

    2009-03-01

    High blood glucose in patients with acute coronary syndromes have been associated with adverse short-term outcomes in patients without diabetes. However, the relation of admission glucose to long-term outcomes in these patients was less well established. Accordingly, consecutive patients with ST-elevation myocardial infarction (STEMI) without diabetes enrolled at 155 sites from July 2000 to November 2002 in the ACOS Registry were evaluated. Patients were categorized into tertiles based on admission blood glucose. Clinical end points of interest were 1-year mortality and composite of death, reinfarction, stroke, or rehospitalization (major adverse cardiac clinical events [MACCEs]) in the hospital and after discharge. Of 5,866 patients with STEMI, 36.9% had blood glucose <120 mg/dl; 33.1%, 120 to 150 mg/dl; and 30.0%, >150 mg/dl. Admission blood glucose was significantly related to increased risk of not only in-hospital events (death, glucose >150 vs <120 mg/dl, adjusted odds ratio [OR] 2.86, 95% confidence interval [CI] 2.13 to 3.82, p <0.0001; and MACCE, >150 vs <120 mg/dl, adjusted OR 1.88, 95% CI 1.52 to 2.33; p <0.0001), but this increased risk persisted beyond the acute phase during 1-year follow-up of a mean 380 days (median 387; death, glucose >150 vs <120 mg/dl, adjusted OR 1.46, 95% CI 1.04 to 2.03, p <0.0001; and MACCE, >150 vs <120 mg/dl, adjusted OR 1.31, 95% CI 1.00 to 1.71, p <0.0001). In conclusion, high blood glucose at admission to the hospital independently correlated with short- and midterm mortality in patients with STEMI.

  1. Activation of the gut calcium-sensing receptor by peptide agonists reduces rapid elevation of plasma glucose in response to oral glucose load in rats.

    PubMed

    Muramatsu, Maya; Hira, Tohru; Mitsunaga, Arimi; Sato, Eri; Nakajima, Shingo; Kitahara, Yoshiro; Eto, Yuzuru; Hara, Hiroshi

    2014-06-15

    The calcium-sensing receptor (CaSR) is expressed in various tissues, including the gastrointestinal tract. To investigate the role of gut CaSR on glycemic control, we examined whether single oral administration of CaSR agonist peptides affected the glycemic response in rats. Glucose tolerance tests were performed under oral or duodenal administration of various CaSR agonist peptides (γGlu-Cys, protamine, and poly-d-lysine hydrobromide) in conscious rats. Involvement of CaSR was determined by using a CaSR antagonist. Signaling pathways underlying CaSR agonist-modified glycemia were investigated using gut hormone receptor antagonists. The gastric emptying rate after the administration of CaSR agonist peptides was measured by the phenol red recovery method. Oral and duodenal administration of CaSR agonist peptides attenuated glycemic responses under the oral glucose tolerance test, but the administration of casein did not. The promotive effect on glucose tolerance was weakened by luminal pretreatment with a CaSR antagonist. Treatment with a 5-HT3 receptor antagonist partially diminished the glucose-lowering effect of peptides. Furthermore, the gastric emptying rate was decreased by duodenal administration of CaSR agonist peptides. These results demonstrate that activation of the gut CaSR by peptide agonists promotes glucose tolerance in conscious rats. 5-HT3 receptor and the delayed gastric emptying rate appear to be involved in the glucose-lowering effect of CaSR agonist peptides. Thus, activation of gut CaSR by dietary peptides reduces glycemic responses so that gut CaSR may be a potential target for the improvement of postprandial glycemia.

  2. Glucose sensing by means of silicon photonics

    NASA Astrophysics Data System (ADS)

    Bockstaele, Ronny; Ryckeboer, Eva; Hattasan, Nannicha; De Koninck, Yannick; Muneeb, Muhammad; Verstuyft, Steven; Delbeke, Danaë; Bogaerts, Wim; Roelkens, Gunther; Baets, Roel

    2014-03-01

    Diabetes is a fast growing metabolic disease, where the patients suffer from disordered glucose blood levels. Monitoring the blood glucose values in combination with extra insulin injection is currently the only therapy to keep the glucose concentration in diabetic patients under control, minimizing the long-term effects of elevated glucose concentrations and improving quality of life of the diabetic patients. Implantable sensors allow continuous glucose monitoring, offering the most reliable data to control the glucose levels. Infrared absorption spectrometers offer a non-chemical measurement method to determine the small glucose concentrations in blood serum. In this work, a spectrometer platform based on silicon photonics is presented, allowing the realization of very small glucose sensors suitable for building implantable sensors. A proof-of-concept of a spectrometer with integrated evanescent sample interface is presented, and the route towards a fully implantable spectrometer is discussed.

  3. Ozone concentrations at a selected high-elevation forest site downwind Mexico City

    NASA Astrophysics Data System (ADS)

    Torres-JArdon, R.

    2013-05-01

    Torres-Jardón, R.*, Rosas-Pérez, I., Granada-Macías, L. M., Ruiz-Suárez, L. G. Centro de Ciencias de la Atmósfera, UNAM, México D. F. México * rtorres@unam.mx For many years, the vegetation of forest species such as Abies religiosa in natural parks located in the southwest mountains of Mexico City has attracted much attention since these parks have been experiencing a severe decline of unclear etiology. The high ozone levels in the area and the observed naked eye macroscopic, histological and cytological injuries on these species, strongly suggest an important contribution of tropospheric ozone to this deterioration process. Apart of historical short monitoring campaigns for measuring ozone levels in these mountains, it is known just a little is known about the present exposure levels at which the local vegetation is exposed. A continuous ozone analyzer has been in operation since 2011 at a high-elevation forest site (Parque Nacional Miguel Hidalgo, PNMH; 3110 m above mean sea level) located downwind of Mexico City Metropolitan Area (MCMA), in order to characterize the local ozone diel amplitude and its seasonal trend, as well as the influence of MCMA on the local O3 concentrations. Hourly average ozone data in PNMH shows that in general, the diel of ozone concentrations in the forest site has a statistical significant correlation with the pattern of ozone levels observed in several monitoring sites (smog receptor sites) within the MCMA, although the high elevation O3 levels are relatively lower than those in the urban area (around 2200 m above mean sea level). It is possible that a part of the oxidants in the air masses are removed by sink deposition processes during the air mass transport across the hills. The diel amplitude of ozone concentrations is small in the cold season, increasing as the seasons advance to June. As in the city, the highest ozone concentrations occur in April or May and the lowest levels during the rainy season, which extends from

  4. Evaluation of Potential pH-Driven Metal Release Due to Elevated Groundwater CO2 Concentrations

    NASA Astrophysics Data System (ADS)

    Tinnacher, R. M.; Varadharajan, C.; Zheng, L.; Spycher, N.; Birkholzer, J. T.; Trautz, R. C.; Pugh, J. D.; Esposito, R.; Nico, P. S.

    2012-12-01

    The injection of carbon dioxide (CO2) emissions from industrial sources into deep geologic formations is a potential option for the control of CO2 concentrations in the atmosphere. While the risk of CO2 migration from the storage reservoir into potable groundwater is low considering the safeguards of site characterization and permitting, it is important to understand what type of potential impacts could occur and how to identify these impacts. Elevated CO2 concentrations may potentially lead to a decrease in groundwater pH and the subsequent release of metals and ions from natural sediments into the groundwater solution. In this risk scenario, potential metal release processes, such as enhanced mineral dissolution, metal desorption and/or ion exchange reactions, may be driven by changes in groundwater pH, the presence of carbonate ligands in solution or a combination of the two. However, a detailed understanding and a distinction of pH-driven and carbonate-driven metal release reactions are important for the development of site monitoring plans and remediation strategies, required by regulations in the unlikely event of a release. Hence, in this study we characterized metal release from natural sediments into synthetic groundwater solutions at two pH conditions in order to mimic the native groundwater pH (pH ~8.5) and the low pH conditions expected in the event of elevated CO2 concentrations (pH~5). In addition, results are compared between tests performed in the presence and absence of elevated CO2. Metal release was investigated in lab-scale sequential leaching experiments using two sediment types with different organic carbon contents over a time-frame of 25 days. Supernatant solutions were monitored for pH and characterized in terms of metal concentrations (ICP-MS), total inorganic carbon (TIC) and anion composition. Furthermore, experimental results were compared with data from a field study involving the controlled release of groundwater containing dissolved

  5. Elevated CO2 concentration around alfalfa nodules increases N2 fixation.

    PubMed

    Fischinger, Stephanie A; Hristozkova, Marieta; Mainassara, Zaman-Allah; Schulze, Joachim

    2010-01-01

    Nodule CO2 fixation via PEPC provides malate for bacteroids and oxaloacetate for N assimilation. The process is therefore of central importance for efficient nitrogen fixation. Nodule CO2 fixation is known to depend on external CO2 concentration. The hypothesis of the present paper was that nitrogen fixation in alfalfa plants is enhanced when the nodules are exposed to elevated CO2 concentrations. Therefore nodulated plants of alfalfa were grown in a hydroponic system that allowed separate aeration of the root/nodule compartment that avoided any gas leakage to the shoots. The root/nodule compartments were aerated either with a 2500 microl l(-1) (+CO2) or zero microl l(-1) (-CO2) CO2-containing N2/O2 gas flow (80/20, v/v). Nodule CO2 fixation, nitrogen fixation, and growth were strongly increased in the +CO2 treatment in a 3-week experimental period. More intensive CO2 and nitrogen fixation coincided with higher per plant amounts of amino acids and organic acids in the nodules. Moreover, the concentration of asparagine was increased in both the nodules and the xylem sap. Plants in the +CO2 treatment tended to develop nodules with higher %N concentration and individual activity. In a parallel experiment on plants with inefficient nodules (fix-) the +CO2 treatment remained without effect. Our data support the thesis that nodule CO2 fixation is pivotal for efficient nitrogen fixation. It is concluded that strategies which enhance nodule CO2 fixation will improve nitrogen fixation and nodule formation. Moreover, sufficient CO2 application to roots and nodules is necessary for growth and efficient nitrogen fixation in hydroponic and aeroponic growth systems.

  6. Elevated blood plasma concentrations of active ghrelin and obestatin in benign ovarian neoplasms and ovarian cancers.

    PubMed

    Markowska, A; Ziółkowska, A; Jaszczyńska-Nowinka, K; Madry, R; Malendowicz, L K

    2009-01-01

    Both ghrelin and obestatin are derived from preproghrelin by post-translational processing. The two peptides are secreted into the blood but circulating levels of these peptides have not been assessed in women with ovarian tumours. Therefore, the purpose of this study was to evaluate peripheral blood concentrations of active and total ghrelin and obestatin in patients with benign ovarian tumours and those with ovarian cancer. The studies were conducted on 22 patients operated due to benign ovarian tumours, and 31 patients operated due to ovarian cancer. A control group consisted of 32 women, 24 to 65 years of age. Both in women with benign ovarian tumours and those with ovarian cancer blood concentrations of active ghrelin and obestatin were higher than in the control group (active ghrelin: 90 +/- 4, 84 +/- 4 and 56 +/- 9 pg/ml, respectively, obestatin: 660 +/- 36; 630 +/- 30 and 538 +/- 31 ng/ml (x +/- SE), respectively). In contrast, total ghrelin concentrations in blood were similar in the studied groups. The alterations resulted in increased values of active to total ghrelin concentration ratio in the peripheral blood of patients with benign ovarian tumours or with ovarian cancer (0.79 +/- 0.02 and 0.93 +/- 0.05, respectively vs 0.58 +/- 0.02 in the control group). Due to the absence of any convincing proof for the presence of a functional GHS-R-1a receptor for ghrelin in human ovaries it did not seem probable that the observed elevated levels of active ghrelin and obestatin were directly linked to development of ovarian tumours.

  7. Comparison of jet injector and insulin pen in controlling plasma glucose and insulin concentrations in type 2 diabetic patients

    PubMed Central

    Guo, Lixin; Xiao, Xinhua; Sun, Xue; Qi, Cuijuan

    2017-01-01

    Abstract This study is conducted to investigate efficacy of an insulin jet injector and an insulin pen in treatment of type 2 diabetic patients. Sixty patients with type 2 diabetes were treated with rapid-acting insulin (regular insulin) and insulin analog (insulin aspart) using the jet injector and the pen in 4 successive test cycles. Postprandial glucose and insulin concentrations in blood were measured over time. Areas under curves of glucose and the insulin were calculated, and efficacy of 2 injection methods in treatment of the diabetes was compared. Regular insulin and insulin aspart administration by the jet injector showed significant decreases in plasma glucose levels as compared to the pen injection (P < 0.05). Postprandial plasma glucose excursions at the time points of 0.5 to 3 hours were obviously lower in the jet-treated patients than the pen-treated ones (P < 0.05). Postprandial plasma insulin levels were markedly higher in the jet-treated patients than the pen-treated ones (P < 0.05). Area under the glucose curve in the pen-treated patients was significantly increased as compared to the jet-treated ones (P < 0.01). Efficacy of the insulin jet injector in treatment of type 2 diabetic patients is obviously superior to the insulin pen in regulating plasma glucose and insulin levels. PMID:28072690

  8. Comparison of jet injector and insulin pen in controlling plasma glucose and insulin concentrations in type 2 diabetic patients.

    PubMed

    Guo, Lixin; Xiao, Xinhua; Sun, Xue; Qi, Cuijuan

    2017-01-01

    This study is conducted to investigate efficacy of an insulin jet injector and an insulin pen in treatment of type 2 diabetic patients. Sixty patients with type 2 diabetes were treated with rapid-acting insulin (regular insulin) and insulin analog (insulin aspart) using the jet injector and the pen in 4 successive test cycles. Postprandial glucose and insulin concentrations in blood were measured over time. Areas under curves of glucose and the insulin were calculated, and efficacy of 2 injection methods in treatment of the diabetes was compared. Regular insulin and insulin aspart administration by the jet injector showed significant decreases in plasma glucose levels as compared to the pen injection (P < 0.05). Postprandial plasma glucose excursions at the time points of 0.5 to 3 hours were obviously lower in the jet-treated patients than the pen-treated ones (P < 0.05). Postprandial plasma insulin levels were markedly higher in the jet-treated patients than the pen-treated ones (P < 0.05). Area under the glucose curve in the pen-treated patients was significantly increased as compared to the jet-treated ones (P < 0.01). Efficacy of the insulin jet injector in treatment of type 2 diabetic patients is obviously superior to the insulin pen in regulating plasma glucose and insulin levels.

  9. Relationship between photosynthesis and leaf nitrogen concentration in ambient and elevated [CO2] in white birch seedlings.

    PubMed

    Cao, Bing; Dang, Qing-Lai; Zhang, Shouren

    2007-06-01

    To study the effects of elevated CO2 concentration ([CO2]) on relationships between nitrogen (N) nutrition and foliar gas exchange parameters, white birch (Betula papyrifera Marsh.) seedlings were exposed to one of five N-supply regimes (10, 80, 150, 220, 290 mg N l(-1)) in either ambient [CO2] (360 micromol mol(-1)) or elevated [CO2] (720 micromol mol(-1)) in environment-controlled greenhouses. Foliar gas exchange and chlorophyll fluorescence were measured after 60 and 80 days of treatment. Photosynthesis showed a substantial down-regulation (up to 57%) in response to elevated [CO2] and the magnitude of the down-regulation generally decreased exponentially with increasing leaf N concentration. When measured at the growth [CO2], elevated [CO2] increased the overall rate of photosynthesis (P(n)) and instantaneous water-use efficiency (IWUE) by up to 69 and 236%, respectively, but decreased transpiration (E) and stomatal conductance (g(s)) in all N treatments. However, the degree of stimulation of photosynthesis by elevated [CO2] decreased as photosynthetic down-regulation increased from 60 days to 80 days of treatment. Elevated [CO2] significantly increased total photosynthetic electron transport in all N treatments at 60 days of treatment, but the effect was insignificant after 80 days of treatment. Both P(n) and IWUE generally increased with increasing leaf N concentration except at very high leaf N concentrations, where both P(n) and IWUE declined. The relationships of P(n) and IWUE with leaf N concentration were modeled with both a linear regression and a second-order polynomial function. Elevated [CO2] significantly and substantially increased the slope of the linear regression for IWUE, but had no significant effect on the slope for P(n). The optimal leaf N concentration for P(n) and IWUE derived from the polynomial function did not differ between the CO2 treatments when leaf N was expressed on a leaf area basis. However, the mass-based optimal leaf N

  10. Pentavalent vanadium at concentration of the underground water level enhances the sweet taste sense to glucose in college students.

    PubMed

    Nagai, Masanori; Saitoh, Junko; Ohno, Hiromi; Hitomi, Chiaki; Wada, Maki

    2006-02-01

    Underground water in volcanic areas contains vanadium when the basalt layer exists among igneous rocks. The concentration of vanadium in drinking water sometimes exceeds 0.8 microM in these areas, however, the physiological effects of vanadium, especially non-toxic effects, at concentrations lower than 1 microM are unknown. In the present experiments, we examined the effect of pentavalent vanadium and tetravalent vanadium at 0.8 and 8.0 microM concentrations on the recognition threshold to taste substances in healthy college students. Pentavalent vanadium, ammonium vanadate, lowered the sweet taste threshold to glucose at 0.8 and 8.0 microM as well. Tetravalent vanadium, vanadium sulfate, did not alter the threshold to glucose either at 8.0 microM or at 0.8 microM. Ammonium vanadate also decreased the sweet taste threshold to L-proline at 8.0 microM. Ammonium vanadate did not influence the sour taste threshold to hydrogen chloride. Neither ammonium sulfate nor ammonium bicarbonate altered the sweet taste threshold to glucose. Therefore, the effect of ammonium vanadate on the sweet taste threshold is attained by vanadium but not by ammonium. It was concluded that pentavalent vanadium at 0.8 microM intensifies the sweet taste sense to glucose rather specifically. We have first shown the physiological effect of vanadium at the concentration of the underground water level.

  11. Impact of estrus expression and conceptus presence on plasma and uterine glucose concentrations up until maternal recognition of pregnancy in beef cattle

    USDA-ARS?s Scientific Manuscript database

    Glucose is an essential component of uterine luminal fluid (ULF), it is a major energy source utilized by the conceptus for growth and development. Previously we reported increased concentrations of glucose in the ULF of cows that exhibited estrus, and observed differences in glucose transporter tr...

  12. Intracranial subdural hematomas with elevated rivaroxaban concentration and subsequently detected spinal subdural hematoma: A case report.

    PubMed

    Yamaguchi, Yoshitaka; Koga, Masatoshi; Matsuki, Takayuki; Hino, Tenyu; Yokota, Chiaki; Toyoda, Kazunori

    2016-07-01

    A 79-year-old lean man with a height of 157cm and weight of 42kg (body mass index, 17.2kg/m(2)) receiving rivaroxaban developed an intracranial subdural hematoma and was treated conservatively. Because he had a reduced creatinine clearance of 44mL/min, his dosage of rivaroxaban was reduced from 15 to 10mg daily according to official Japanese prescribing information. However, he developed bilateral intracranial subdural hematomas 2weeks later. Plasma rivaroxaban concentration on anti-factor Xa chromogenic assay was elevated at 301ng/mL, suggesting excessive accumulation. He underwent burr hole drainage and resumed anticoagulation with warfarin. Subsequently, he developed a lumbosacral hematoma. He was treated conservatively and discharged without neurological sequelae. The main cause of the increased concentration of rivaroxaban was believed to be his older age and low body weight. The etiology of the spinal hematoma was suspected to be the migration of intracranial hematoma to the spinal subdural space.

  13. Physical and chemical changes in whey protein concentrate stored at elevated temperature and humidity.

    PubMed

    Tunick, Michael H; Thomas-Gahring, Audrey; Van Hekken, Diane L; Iandola, Susan K; Singh, Mukti; Qi, Phoebe X; Ukuku, Dike O; Mukhopadhyay, Sudarsan; Onwulata, Charles I; Tomasula, Peggy M

    2016-03-01

    In a case study, we monitored the physical properties of 2 batches of whey protein concentrate (WPC) under adverse storage conditions to provide information on shelf life in hot, humid areas. Whey protein concentrates with 34.9 g of protein/100g (WPC34) and 76.8 g of protein/100g (WPC80) were stored for up to 18 mo under ambient conditions and at elevated temperature and relative humidity. The samples became yellower with storage; those stored at 35 °C were removed from the study by 12 mo because of their unsatisfactory appearance. Decreases in lysine and increases in water activity, volatile compound formation, and powder caking values were observed in many specimens. Levels of aerobic mesophilic bacteria, coliforms, yeast, and mold were <3.85 log10 cfu/g in all samples. Relative humidity was not a factor in most samples. When stored in sealed bags, these samples of WPC34 and WPC80 had a shelf life of 9 mo at 35 °C but at least 18 mo at lower temperatures, which should extend the market for these products.

  14. Effects of elevated CO2 concentration on seed production in C3 annual plants.

    PubMed

    Hikosaka, Kouki; Kinugasa, Toshihiko; Oikawa, Shimpei; Onoda, Yusuke; Hirose, Tadaki

    2011-02-01

    The response of seed production to CO(2) concentration ([CO(2)]) is known to vary considerably among C(3) annual species. Here we analyse the interspecific variation in CO(2) responses of seed production per plant with particular attention to nitrogen use. Provided that seed production is limited by nitrogen availability, an increase in seed mass per plant results from increase in seed nitrogen per plant and/or from decrease in seed nitrogen concentration ([N]). Meta-analysis reveals that the increase in seed mass per plant under elevated [CO(2)] is mainly due to increase in seed nitrogen per plant rather than seed [N] dilution. Nitrogen-fixing legumes enhanced nitrogen acquisition more than non-nitrogen-fixers, resulting in a large increase in seed mass per plant. In Poaceae, an increase in seed mass per plant was also caused by a decrease in seed [N]. Greater carbon allocation to albumen (endosperm and/or perisperm) than the embryo may account for [N] reduction in grass seeds. These differences in CO(2) response of seed production among functional groups may affect their fitness, leading to changes in species composition in the future high-[CO(2)] ecosystem.

  15. Bacteria with dual resistance to elevated concentrations of heavy metals and antibiotics in Nigerian contaminated systems.

    PubMed

    Oyetibo, Ganiyu O; Ilori, Matthew O; Adebusoye, Sunday Adekunle; Obayori, Oluwafemi S; Amund, Olukayode O

    2010-09-01

    Samples of soil, water, and sediments from industrial estates in Lagos were collected and analyzed for heavy metals and physicochemical composition. Bacteria that are resistant to elevated concentrations of metals (Cd(2+), Co(2+), Ni(2+), Cr(6+), and Hg(2+)) were isolated from the samples, and they were further screened for antibiotic sensitivity. The minimum tolerance concentrations (MTCs) of the isolates with dual resistance to the metals were determined. The physicochemistry of all the samples indicated were heavily polluted. Twenty-two of the 270 bacterial strains isolated showed dual resistances to antibiotics and heavy metals. The MTCs of isolates to the metals were 14 mM for Cd(2+), 15 mM for Co(2+) and Ni(2+), 17 mM for Cr(6+), and 10 mM for Hg(2+). Five strains (Pseudomonas aeruginosa, Actinomyces turicensis, Acinetobacter junni, Nocardia sp., and Micrococcus sp.) resisted all the 18 antibiotics tested. Whereas Rhodococcus sp. and Micrococcus sp. resisted 15 mM Ni(2+), P. aeruginosa resisted 10 mM Co(2+). To our knowledge, there has not been any report of bacterial strains resisting such high doses of metals coupled with wide range of antibiotics. Therefore, dual expressions of antibiotics and heavy-metal resistance make the isolates, potential seeds for decommissioning of sites polluted with industrial effluents rich in heavy metals, since the bacteria will be able to withstand in situ antibiosis that may prevail in such ecosystems.

  16. Elevated house dust and serum concentrations of PBDEs in California: unintended consequences of furniture flammability standards?

    PubMed

    Zota, Ami R; Rudel, Ruthann A; Morello-Frosch, Rachel A; Brody, Julia Green

    2008-11-01

    Studies show higher house dust and body burden levels of PBDE flame retardants in North America than Europe; but little is known about exposure variation within North America, where California's furniture flammability standard affects PBDE use. We compared dust samples from 49 homes in two California communities with 120 Massachusetts homes and with other published studies. Dust concentrations [median (range) ng/g] in California homes of BDE-47, -99, and -100 were 2700 (112-107,000), 3800 (102-170,000), and 684 (concentrations were the highest ever reported in indoor dust. We then investigated whether human serum PBDE levels were also higher in California compared to other North American regions by analyzing the 2003-2004 National Health and Nutrition Examination Survey (NHANES), the only data set available with serum from a representative sample of the U.S. population (n=2040). California residence was significantly associated with nearly 2-fold higher sigma PBDE serum levels [least square geometric mean (LSGM) ng/g lipid, 73.0 vs 38.5 (p = 0.002)]. Elevated PBDE exposures in California may result from the state's furniture flammability standards; our results suggest the need for further research in a larger representative sample.

  17. Elevated Endogenous Erythropoietin Concentrations Are Associated with Increased Risk of Brain Damage in Extremely Preterm Neonates

    PubMed Central

    Korzeniewski, Steven J.; Allred, Elizabeth; Logan, J. Wells; Fichorova, Raina N.; Engelke, Stephen; Kuban, Karl C. K.; O’Shea, T. Michael; Paneth, Nigel; Holm, Mari; Dammann, Olaf; Leviton, Alan

    2015-01-01

    Background We sought to determine, in very preterm infants, whether elevated perinatal erythropoietin (EPO) concentrations are associated with increased risks of indicators of brain damage, and whether this risk differs by the co-occurrence or absence of intermittent or sustained systemic inflammation (ISSI). Methods Protein concentrations were measured in blood collected from 786 infants born before the 28th week of gestation. EPO was measured on postnatal day 14, and 25 inflammation-related proteins were measured weekly during the first 2 postnatal weeks. We defined ISSI as a concentration in the top quartile of each of 25 inflammation-related proteins on two separate days a week apart. Hypererythropoietinemia (hyperEPO) was defined as the highest quartile for gestational age on postnatal day 14. Using logistic regression and multinomial logistic regression models, we compared risks of brain damage among neonates with hyperEPO only, ISSI only, and hyperEPO+ISSI, to those who had neither hyperEPO nor ISSI, adjusting for gestational age. Results Newborns with hyperEPO, regardless of ISSI, were more than twice as likely as those without to have very low (< 55) Mental (OR 2.3; 95% CI 1.5-3.5) and/or Psychomotor (OR 2.4; 95% CI 1.6-3.7) Development Indices (MDI, PDI), and microcephaly at age two years (OR 2.4; 95%CI 1.5-3.8). Newborns with both hyperEPO and ISSI had significantly increased risks of ventriculomegaly, hemiparetic cerebral palsy, microcephaly, and MDI and PDI < 55 (ORs ranged from 2.2-6.3), but not hypoechoic lesions or other forms of cerebral palsy, relative to newborns with neither hyperEPO nor ISSI. Conclusion hyperEPO, regardless of ISSI, is associated with elevated risks of very low MDI and PDI, and microcephaly, but not with any form of cerebral palsy. Children with both hyperEPO and ISSI are at higher risk than others of very low MDI and PDI, ventriculomegaly, hemiparetic cerebral palsy, and microcephaly. PMID:25793991

  18. Plasma ET-1 Concentrations are Elevated in Patients with Hypertension - Meta-Analysis of Clinical Studies.

    PubMed

    Xu, Mei; Lu, Yong-Ping; Hasan, Ahmed Abdallah; Hocher, Berthold

    2017-01-01

    A recent study revealed that global overexpression of ET-1 causes a slight reduction in systemic blood pressure. Moreover, heterozygous ET-1 knockout mice are hypertensive. The role of ET-1 in human hypertension was so far not addressed by a strict meta-analysis of published human clinical studies. We included studies published between January 1, 1990 and February 28, 2017. We included case control studies analyzing untreated essential hypertension or hypertensive patients where antihypertensive medication was discontinued for at least two weeks. Based on the principle of Cochrane systematic reviews, case control studies (CCSs) in PubMed (Medline) and Google Scholar designed to identify the role of endothelin-1 (ET-1) in the pathophysiological of hypertension were screened. Review Manager Version 5.0 (Rev-Man 5.0) was applied for statistical analysis. Mean difference and 95% confidence interval (CI) were shown in inverse variance (IV) fixed-effects model or IV random-effects models. Eleven studies fulfilling our in- and exclusion criteria were eligible for this meta-analysis. These studies included 450 hypertensive patients and 328 controls. Our meta-analysis revealed that ET-1 plasma concentrations were higher in hypertensive patients as compared to the control patients [mean difference between groups 1.57 pg/mL, 95%CI [0.47∼2.68, P = 0.005]. These finding were driven by patients having systolic blood pressure higher than 160 mmHg and diastolic blood pressure higher than 100 mmHg. This meta-analysis showed that hypertensive patients do have elevated plasma ET-1 concentrations. This finding is driven by those patients with high systolic/diastolic blood pressure. Given that the ET-1 gene did not appear in any of the whole genome association studies searching for hypertension associated gene loci, it is very likely that the elevated plasma ET-1 concentrations in hypertensive patients are secondary to hypertension and may reflect endothelial cell damage. © 2017 The

  19. Factors controlling elevated lead concentrations in water samples from aquifer systems in Florida

    USGS Publications Warehouse

    Katz, B.G.; Bullen, M.P.; Bullen, T.D.; Hansard, Paul

    1999-01-01

    Concentrations of total lead (Pb) and dissolved Pb exceeded the U.S. Environmental Protection Agency action level of 15 micrograms per liter (mg/L) in approximately 19 percent and 1.3 percent, respectively, of ground-water samples collected during 1991-96 from a statewide network of monitoring wells designed to delineate background water quality of Florida's major aquifer systems. Differences in total Pb concentrations among aquifer systems reflect the combined influence of anthropogenic sources and chemical conditions in each system. A highly significant (p<0.001) difference in median total Pb concentrations was found for water samples from wells with water-level recording devices that contain Pb-counterweights (14 mg/L) compared to non-recorder wells (2 mg/L). Differences between total Pb concentrations for recorder and non-recorder wells are even more pronounced when compared for each aquifer system. The largest differences for recorder status are found for the surficial aquifer system, where median total Pb concentrations are 44 and 2.4 mg/L for recorder wells and non-recorder wells, respectively. Leaching of Pb from metal casing materials is another potential source of Pb in ground water samples. Median total Pb concentrations in water samples from the surficial, intermediate, and Floridan aquifer systems are higher from recorder wells cased with black iron than for recorder wells with steel and PVC casing material. Stable isotopes of Pb were used in this study to distinguish between anthropogenic and natural sources of Pb in ground water, as Pb retains the isotopic signature of the source from which it is derived. Based on similarities between slopes and intercepts of trend lines for various sample types (plots of 206Pb/204Pb versus 208Pb/204Pb and 207Pb/204Pb versus 208Pb/204Pb) the predominant source of total Pb in water samples from the surficial aquifer system is corrosion of Pb counterweights. It is likely that only ground-water samples, not the aquifer

  20. Elevated concentration of secretory leukocyte protease inhibitor in the cervical mucus before delivery.

    PubMed

    Samejima, Taiki; Nagamatsu, Takeshi; Schust, Danny J; Itaoka, Nao; Iriyama, Takayuki; Nakayama, Toshio; Komatsu, Atsushi; Kawana, Kei; Osuga, Yutaka; Fujii, Tomoyuki

    2016-06-01

    odds ratio, 1.28; 95% confidence interval, 1.07-1.61). A cut-off value of cervical secretory leukocyte protease inhibitor/total protein to predict delivery within 7 days was determined to be 1.62 μg/mg (sensitivity, 0.69; specificity, 0.72) using receiver operating characteristic curve-analysis. Secretory leukocyte protease inhibitor concentrations in the cervical mucus elevate progressively before delivery in uncomplicated term pregnancies. Our findings suggest that cervical secretory leukocyte protease inhibitor is a candidate biomarker for delivery prediction. Copyright © 2016 Elsevier Inc. All rights reserved.