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Sample records for 1-hour ogtt glucose

  1. 1-Hour OGTT Plasma Glucose as a Marker of Progressive Deterioration of Insulin Secretion and Action in Pregnant Women.

    PubMed

    Ghio, Alessandra; Seghieri, Giuseppe; Lencioni, Cristina; Anichini, Roberto; Bertolotto, Alessandra; De Bellis, Alessandra; Resi, Veronica; Lacaria, Emilia; Del Prato, Stefano; Di Cianni, Graziano

    2012-01-01

    Considering old GDM diagnostic criteria, alterations in insulin secretion and action are present in women with GDM as well as in women with one abnormal value (OAV) during OGTT. Our aim is to assess if changes in insulin action and secretion during pregnancy are related to 1-hour plasma glucose concentration during OGTT. We evaluated 3 h/100 g OGTT in 4,053 pregnant women, dividing our population on the basis of 20 mg/dL increment of plasma glucose concentration at 1 h OGTT generating 5 groups (<120 mg/dL, n = 661; 120-139 mg/dL, n = 710; 140-159 mg/dL, n = 912; 160-179 mg/dL, n = 885; and ≥180 mg/dL, n = 996). We calculated incremental area under glucose (AUC(gluc)) and insulin curves (AUC(ins)), indexes of insulin secretion (HOMA-B), and insulin sensitivity (HOMA-R), AUC(ins)/AUC(gluc). AUC(gluc) and AUC(ins) progressively increased according to 1-hour plasma glucose concentrations (both P < 0.0001 for trend). HOMA-B progressively declined (P < 0.001), and HOMA-R progressively increased across the five groups. AUC(ins)/AUC(gluc) decreased in a linear manner across the 5 groups (P < 0.001). Analysing the groups with 1-hour value <180 mg/dL, defects in insulin secretion (HOMA-B: -29.7%) and sensitivity (HOMA-R: +15%) indexes were still apparent (all P < 0.001). Progressive increase in 1-hour OGTT is associated with deterioration of glucose tolerance and alterations in indexes of insulin action and secretion. PMID:22567007

  2. Maternal 75-g OGTT glucose levels as predictive factors for large-for-gestational age newborns in women with gestational diabetes mellitus.

    PubMed

    Brankica, Krstevska; Valentina, Velkoska Nakova; Slagjana, Simeonova Krstevska; Sasha, Jovanovska Mishevska

    2016-02-01

    Objective Our goal was to investigate which glucose measurement from the 75-g oral glucose tolerance test (OGTT) has more capability of predicting large for-gestational-age (LGA) newborns of mothers with gestational diabetes mellitus (GDM). Subjects and methods The study group consisted of 118 consecutively pregnant women with singleton pregnancy, patients of Outpatients Department of the Endocrinology, Diabetes, and Metabolic Disorders Clinic. All were prospectively screened for GDM between 24th and 28th week of pregnancy and followed to delivery. Outcome measures included: patients' ages, pre-pregnancy BMI, BMI before delivery, FPG, 1 and 2 hour OGTT glucose values, haemoglobin A1c at third trimester, gestational week of delivery, mode of delivery and baby birth weight. Results From 118 pregnancies, 78 (66.1%) women were with GDM, and 40 (33.9%) without GDM. There were statistically significant differences (30.7 versus 5.0%, p < 0.01) between LGA newborns from GDM and control group, respectively. Gestation week of delivery and fasting glucose levels were independent predictors for LGA (Beta = 0.58 and Beta = 0.37 respectively, p < 0.01). Areas under the receiver operator characteristic curve (AUC) were compared for the prediction of LGA (0.782 (0.685-0.861) for fasting, 0.719 (0.607-0.815) for 1-hour and 0.51 (0.392-0.626) for 2-hour OGTT plasma glucose levels). Conclusion Fasting and 1-hour plasma glucose levels from OGTT may predict LGA babies in GDM pregnancies. PMID:26909480

  3. 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 Central

    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

    Objective 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. Design 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. Setting Follow-up of clinical trial. Participants 504 individuals with IGT were followed with yearly evaluations with OGTT, FPG and HbA1c. Main Outcome Measure Relative risk of CVD. Results 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. Conclusions and Relevance 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. PMID:25285769

  4. Post-glucose-load urinary C-peptide and glucose concentration obtained during OGTT do not affect oral minimal model-based plasma indices.

    PubMed

    Jainandunsing, Sjaam; Wattimena, J L Darcos; Rietveld, Trinet; van Miert, Joram N I; Sijbrands, Eric J G; de Rooij, Felix W M

    2016-05-01

    The purpose of this study was to investigate how renal loss of both C-peptide and glucose during oral glucose tolerance test (OGTT) relate to and affect plasma-derived oral minimal model (OMM) indices. All individuals were recruited during family screening between August 2007 and January 2011 and underwent a 3.5-h OGTT, collecting nine plasma samples and urine during OGTT. We obtained the following three subgroups: normoglycemic, at risk, and T2D. We recruited South Asian and Caucasian families, and we report separate analyses if differences occurred. Plasma glucose, insulin, and C-peptide concentrations were analyzed as AUCs during OGTT, OMM estimate of renal C-peptide secretion, and OMM beta-cell and insulin sensitivity indices were calculated to obtain disposition indices. Post-glucose load glucose and C-peptide in urine were measured and related to plasma-based indices. Urinary glucose corresponded well with plasma glucose AUC (Cau r = 0.64, P < 0.01; SA r = 0.69, P < 0.01), S I (Cau r = -0.51, P < 0.01; SA r = -0.41, P < 0.01), Φ dynamic (Cau r = -0.41, P < 0.01; SA r = -0.57, P < 0.01), and Φ oral (Cau r = -0.61, P < 0.01; SA r = -0.73, P < 0.01). Urinary C-peptide corresponded well to plasma C-peptide AUC (Cau r = 0.45, P < 0.01; SA r = 0.33, P < 0.05) and OMM estimate of renal C-peptide secretion (r = 0.42, P < 0.01). In general, glucose excretion plasma threshold for the presence of glucose in urine was ~10-10.5 mmol L(-1) in non-T2D individuals, but not measurable in T2D individuals. Renal glucose secretion during OGTT did not influence OMM indices in general nor in T2D patients (renal clearance range 0-2.1 %, with median 0.2 % of plasma glucose AUC). C-indices of urinary glucose to detect various stages of glucose intolerance were excellent (Cau 0.83-0.98; SA 0.75-0.89). The limited role of renal glucose secretion validates the neglecting of urinary glucose secretion in kinetic models of glucose

  5. Glucose fluxes during OGTT in adolescents assessed by a stable isotope triple tracer method.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Virtually no information is available on glucose fluxes during a meal or glucose ingestion in adolescents. Our study was designed to use a triple tracer approach to measure rates of appearance of ingested glucose (Raogtt), endogenous glucose production (EGP), and glucose disappearance (Rd) following...

  6. Prevalence of Undiagnosed Diabetes in Rheumatoid Arthritis: an OGTT Study.

    PubMed

    Ursini, Francesco; Russo, Emilio; D'Angelo, Salvatore; Arturi, Franco; Hribal, Marta Letizia; D'Antona, Lucia; Bruno, Caterina; Tripepi, Giovanni; Naty, Saverio; De Sarro, Giovambattista; Olivieri, Ignazio; Grembiale, Rosa Daniela

    2016-02-01

    Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by an excess of cardiovascular disease (CVD) risk, estimated to be at least 50% greater when compared to the general population. Although the widespread diffusion of type 2 diabetes mellitus (T2DM) awareness, there is still a significant proportion of patients with T2DM that remain undiagnosed. Aim of this cross-sectional study was to evaluate the prevalence of undiagnosed diabetes and prediabetes in RA patients. For the present study, 100 consecutive nondiabetic RA patients were recruited. Age- and sex-matched subjects with noninflammatory diseases (osteoarthritis or fibromyalgia) were used as controls. After overnight fasting, blood samples were obtained for laboratory evaluation including serum glucose, total cholesterol, high-density lipoprotein (HDL)-cholesterol, low-density lipoprotein (LDL)-cholesterol, triglycerides, uric acid, erythrocyte sedimentation rate (ESR), high sensitivity C-reactive protein (hs-CRP), rheumatoid factor (RF), and anti-Cyclic Citrullinated Peptide Antibodies (ACPA). A standard Oral Glucose Tolerance Test (OGTT) with 75 g of glucose was performed and blood samples were collected at time 0, 30, 60, 90, and 120 minutes, for measurement of plasma glucose concentrations. The prevalence of impaired fasting glucose (IFG) (9/100 vs 12/100, P = 0.49), impaired glucose tolerance (IGT) (19/100 vs 12/100, P = 0.17), and concomitant IFG/IGT (5/100 vs 9/100, P = 0.27) was similar between groups, whereas the prevalence of diabetes was significantly higher in RA patients (10/100 vs 2/100, P = 0.02). In a logistic regression analysis, increasing age (OR = 1.13, 95% CI 1.028-1.245, P = 0.01) and disease duration (OR = 1.90, 95% CI 1.210-2.995, P = 0.005) were both associated with an increased likelihood of being classified as prediabetes (i.e. IFG and/or IGT) or T2DM. A ROC curve was built to evaluate the predictivity of disease duration on the

  7. Glucose tolerance test - non-pregnant

    MedlinePlus

    Oral glucose tolerance test - non-pregnant; OGTT - non-pregnant; Diabetes - glucose tolerance test ... The most common glucose tolerance test is the oral glucose tolerance test (OGTT). Before the test begins, a sample of blood will be taken. You will then ...

  8. Sustained Decrease of Early-Phase Insulin Secretion in Japanese Women with Gestational Diabetes Mellitus Who Developed Impaired Glucose Tolerance and Impaired Fasting Glucose Postpartum

    PubMed Central

    Katayama, Hiroko; Tachibana, Daisuke; Hamuro, Akihiro; Misugi, Takuya; Motoyama, Koka; Morioka, Tomoaki; Fukumoto, Shinya; Emoto, Masanori; Inaba, Masaaki; Koyama, Masayasu

    2015-01-01

    OBJECTIVE The aim of this study was to compare glucose intolerance in the antenatal and the postpartum periods using a 75-g oral glucose tolerance test (OGTT) in the Japanese women with gestational diabetes mellitus (GDM) using a retrospective design. PATIENTS AND METHODS Data were obtained from 85 Japanese women with GDM who delivered from April 2011 through April 2015 and who underwent an OGTT 6–14 weeks postpartum. The women were divided into two groups based on the results of the postpartum OGTT: one group with normal glucose tolerance (NGT) and the other with impaired glucose tolerance (IGT) as well as impaired fasting glucose (IFG). We analyzed the associations between postpartum IGT–IFG and various factors. RESULTS Antenatally, a significant difference was observed between the groups only in the 1-hour plasma glucose level of the 75-g OGTT. Postpartum results of plasma glucose level were significantly higher at 0.5, 1, and 2 hours in the IGT–IFG group than those in the NGT group. Moreover, a significant decrease in the levels of 0.5-hour immunoreactive insulin and insulinogenic index was observed in the IGT–IFG group compared to those in the NGT group. Homeostasis model assessment-insulin resistance and homeostasis model assessment β-cell function of both groups were found to significantly decrease in the postpartum period; however, there was no significant change in the insulinogenic index of either group. CONCLUSIONS Our study clearly showed that the postpartum IGT and IFG levels of Japanese women with GDM are affected by impaired early-phase insulin secretion; however, insulin resistance promptly improves. PMID:26688669

  9. Prevalence of Undiagnosed Diabetes in Rheumatoid Arthritis: an OGTT Study

    PubMed Central

    Ursini, Francesco; Russo, Emilio; D’Angelo, Salvatore; Arturi, Franco; Hribal, Marta Letizia; D’Antona, Lucia; Bruno, Caterina; Tripepi, Giovanni; Naty, Saverio; De Sarro, Giovambattista; Olivieri, Ignazio; Grembiale, Rosa Daniela

    2016-01-01

    Abstract Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by an excess of cardiovascular disease (CVD) risk, estimated to be at least 50% greater when compared to the general population. Although the widespread diffusion of type 2 diabetes mellitus (T2DM) awareness, there is still a significant proportion of patients with T2DM that remain undiagnosed. Aim of this cross-sectional study was to evaluate the prevalence of undiagnosed diabetes and prediabetes in RA patients. For the present study, 100 consecutive nondiabetic RA patients were recruited. Age- and sex-matched subjects with noninflammatory diseases (osteoarthritis or fibromyalgia) were used as controls. After overnight fasting, blood samples were obtained for laboratory evaluation including serum glucose, total cholesterol, high-density lipoprotein (HDL)-cholesterol, low-density lipoprotein (LDL)-cholesterol, triglycerides, uric acid, erythrocyte sedimentation rate (ESR), high sensitivity C-reactive protein (hs-CRP), rheumatoid factor (RF), and anti-Cyclic Citrullinated Peptide Antibodies (ACPA). A standard Oral Glucose Tolerance Test (OGTT) with 75 g of glucose was performed and blood samples were collected at time 0, 30, 60, 90, and 120 minutes, for measurement of plasma glucose concentrations. The prevalence of impaired fasting glucose (IFG) (9/100 vs 12/100, P = 0.49), impaired glucose tolerance (IGT) (19/100 vs 12/100, P = 0.17), and concomitant IFG/IGT (5/100 vs 9/100, P = 0.27) was similar between groups, whereas the prevalence of diabetes was significantly higher in RA patients (10/100 vs 2/100, P = 0.02). In a logistic regression analysis, increasing age (OR = 1.13, 95% CI 1.028–1.245, P = 0.01) and disease duration (OR = 1.90, 95% CI 1.210–2.995, P = 0.005) were both associated with an increased likelihood of being classified as prediabetes (i.e. IFG and/or IGT) or T2DM. A ROC curve was built to evaluate the predictivity of disease

  10. Glucose screening and tolerance tests during pregnancy

    MedlinePlus

    Oral glucose tolerance test - pregnancy (OGTT); Glucose challenge test - pregnancy ... For the glucose screening test: You do not need to prepare or change your diet in any way. You will be asked to drink a ...

  11. Routine OGTT: A Robust Model Including Incretin Effect for Precise Identification of Insulin Sensitivity and Secretion in a Single Individual

    PubMed Central

    De Gaetano, Andrea; Panunzi, Simona; Matone, Alice; Samson, Adeline; Vrbikova, Jana; Bendlova, Bela; Pacini, Giovanni

    2013-01-01

    In order to provide a method for precise identification of insulin sensitivity from clinical Oral Glucose Tolerance Test (OGTT) observations, a relatively simple mathematical model (Simple Interdependent glucose/insulin MOdel SIMO) for the OGTT, which coherently incorporates commonly accepted physiological assumptions (incretin effect and saturating glucose-driven insulin secretion) has been developed. OGTT data from 78 patients in five different glucose tolerance groups were analyzed: normal glucose tolerance (NGT), impaired glucose tolerance (IGT), impaired fasting glucose (IFG), IFG+IGT, and Type 2 Diabetes Mellitus (T2DM). A comparison with the 2011 Salinari (COntinuos GI tract MOdel, COMO) and the 2002 Dalla Man (Dalla Man MOdel, DMMO) models was made with particular attention to insulin sensitivity indices ISCOMO, ISDMMO and kxgi (the insulin sensitivity index for SIMO). ANOVA on kxgi values across groups resulted significant overall (P<0.001), and post-hoc comparisons highlighted the presence of three different groups: NGT (8.62×10−5±9.36×10−5 min−1pM−1), IFG (5.30×10−5±5.18×10−5) and combined IGT, IFG+IGT and T2DM (2.09×10−5±1.95×10−5, 2.38×10−5±2.28×10−5 and 2.38×10−5±2.09×10−5 respectively). No significance was obtained when comparing ISCOMO or ISDMMO across groups. Moreover, kxgi presented the lowest sample average coefficient of variation over the five groups (25.43%), with average CVs for ISCOMO and ISDMMO of 70.32% and 57.75% respectively; kxgi also presented the strongest correlations with all considered empirical measures of insulin sensitivity. While COMO and DMMO appear over-parameterized for fitting single-subject clinical OGTT data, SIMO provides a robust, precise, physiologically plausible estimate of insulin sensitivity, with which habitual empirical insulin sensitivity indices correlate well. The kxgi index, reflecting insulin secretion dependency on glycemia, also significantly differentiates clinically

  12. Routine OGTT: a robust model including incretin effect for precise identification of insulin sensitivity and secretion in a single individual.

    PubMed

    De Gaetano, Andrea; Panunzi, Simona; Matone, Alice; Samson, Adeline; Vrbikova, Jana; Bendlova, Bela; Pacini, Giovanni

    2013-01-01

    In order to provide a method for precise identification of insulin sensitivity from clinical Oral Glucose Tolerance Test (OGTT) observations, a relatively simple mathematical model (Simple Interdependent glucose/insulin MOdel SIMO) for the OGTT, which coherently incorporates commonly accepted physiological assumptions (incretin effect and saturating glucose-driven insulin secretion) has been developed. OGTT data from 78 patients in five different glucose tolerance groups were analyzed: normal glucose tolerance (NGT), impaired glucose tolerance (IGT), impaired fasting glucose (IFG), IFG+IGT, and Type 2 Diabetes Mellitus (T2DM). A comparison with the 2011 Salinari (COntinuos GI tract MOdel, COMO) and the 2002 Dalla Man (Dalla Man MOdel, DMMO) models was made with particular attention to insulin sensitivity indices ISCOMO, ISDMMO and kxgi (the insulin sensitivity index for SIMO). ANOVA on kxgi values across groups resulted significant overall (P<0.001), and post-hoc comparisons highlighted the presence of three different groups: NGT (8.62×10(-5)±9.36×10(-5) min(-1)pM(-1)), IFG (5.30×10(-5)±5.18×10(-5)) and combined IGT, IFG+IGT and T2DM (2.09×10(-5)±1.95×10(-5), 2.38×10(-5)±2.28×10(-5) and 2.38×10(-5)±2.09×10(-5) respectively). No significance was obtained when comparing ISCOMO or ISDMMO across groups. Moreover, kxgi presented the lowest sample average coefficient of variation over the five groups (25.43%), with average CVs for ISCOMO and ISDMMO of 70.32% and 57.75% respectively; kxgi also presented the strongest correlations with all considered empirical measures of insulin sensitivity. While COMO and DMMO appear over-parameterized for fitting single-subject clinical OGTT data, SIMO provides a robust, precise, physiologically plausible estimate of insulin sensitivity, with which habitual empirical insulin sensitivity indices correlate well. The kxgi index, reflecting insulin secretion dependency on glycemia, also significantly differentiates clinically

  13. Association between One-Hour Post-Load Plasma Glucose Levels and Vascular Stiffness in Essential Hypertension

    PubMed Central

    Sciacqua, Angela; Maio, Raffaele; Miceli, Sofia; Pascale, Alessandra; Carullo, Giuseppe; Grillo, Nadia; Arturi, Franco; Sesti, Giorgio; Perticone, Francesco

    2012-01-01

    Objectives Pulse wave velocity (PWV) is a surrogate end-point for cardiovascular morbidity and mortality. A plasma glucose value ≥155 mg/dl for the 1-hour post-load plasma glucose during an oral glucose tolerance test (OGTT) is able to identify subjects with normal glucose tolerance (NGT) at high-risk for type-2 diabetes (T2D) and for subclinical organ damage. Thus, we addressed the question if 1-hour post-load plasma glucose levels, affects PWV and its central hemodynamic correlates, as augmentation pressure (AP) and augmentation index (AI). Methods We enrolled 584 newly diagnosed hypertensives. All patients underwent OGTT and measurements of PWV, AP and AI. Insulin sensitivity was assessed by Matsuda-index. Results Among participants, 424 were NGT and 160 had impaired glucose tolerance (IGT). Of 424 NGT, 278 had 1-h post-load plasma glucose <155 mg/dl (NGT<155) and 146 had 1-h post-load plasma glucose ≥155 mg/dl (NGT≥155). NGT≥155 had a worse insulin sensitivity and higher hs-CRP than NGT<155, similar to IGT subjects. In addition, NGT ≥155 in comparison with NGT<155 had higher central systolic blood pressure (134±12 vs 131±10 mmHg), as well as PWV (8.4±3.7 vs 6.7±1.7 m/s), AP (12.5±7.1 vs 9.8±5.7 mmHg) and AI (29.4±11.9 vs 25.1±12.4%), and similar to IGT. At multiple regression analysis, 1-h post-load plasma glucose resulted the major determinant of all indices of vascular stiffness. Conclusion Hypertensive NGT≥155 subjects, compared with NGT<155, have higher PWV and its hemodynamic correlates that increase their cardiovascular risk profile. PMID:23028545

  14. One-Hour Postload Plasma Glucose Levels Are Associated with Kidney Dysfunction

    PubMed Central

    Succurro, Elena; Arturi, Franco; Lugarà, Marina; Grembiale, Alessandro; Fiorentino, Teresa Vanessa; Caruso, Vittoria; Andreozzi, Francesco; Sciacqua, Angela; Hribal, Marta Letizia; Perticone, Francesco

    2010-01-01

    Background and objectives: A cutoff of 155 mg/dl for 1-hour postload plasma glucose (1hPG) during the oral glucose tolerance test (OGTT) is able to identify patients who are at high risk for type 2 diabetes and vascular atherosclerosis. We aimed to examine whether individuals with 1hPG ≥155 mg/dl are also at increased risk for chronic kidney disease (CKD). Design, setting, participants, & measurements: Atherosclerosis risk factors, OGTT, and estimated GFR by Chronic Kidney Disease Epidemiology Collaboration equation were analyzed in 1075 white individuals without diabetes. Results: The area under the receiver operating characteristic curve for 1hPG was the highest (0.700) compared with the areas under the receiver operating characteristic curve of 0, 30-minute, and 2-hour glucose concentrations. Individuals with 1hPG ≥155 mg/dl had a worse cardiometabolic risk profile, exhibiting significantly higher body mass index, BP, triglycerides, and fasting insulin levels and lower HDL, IGF-1 levels, and insulin sensitivity, than individuals with 1hPG <155 mg/dl. Estimated GFR was significantly lower in individuals with 1hPG ≥155 mg/dl. In a logistic regression model adjusted for age and gender, individuals with 1hPG ≥155 mg/dl showed an increased risk for CKD compared with individuals with 1hPG <155 mg/dl. When the logistic regression analysis was restricted to individuals who had normal glucose tolerance, those with 1hPG ≥155 mg/dl showed a higher risk for CKD compared with individuals with 1hPG <155 mg/dl. Conclusions: These data suggest that a cutoff point of 155 mg/dl for the 1hPG during OGTT may be helpful in the identification of individuals who are at increased risk for CKD. PMID:20595688

  15. Metabolite profiles during oral glucose challenge.

    PubMed

    Ho, Jennifer E; Larson, Martin G; Vasan, Ramachandran S; Ghorbani, Anahita; Cheng, Susan; Rhee, Eugene P; Florez, Jose C; Clish, Clary B; Gerszten, Robert E; Wang, Thomas J

    2013-08-01

    To identify distinct biological pathways of glucose metabolism, we conducted a systematic evaluation of biochemical changes after an oral glucose tolerance test (OGTT) in a community-based population. Metabolic profiling was performed on 377 nondiabetic Framingham Offspring cohort participants (mean age 57 years, 42% women, BMI 30 kg/m(2)) before and after OGTT. Changes in metabolite levels were evaluated with paired Student t tests, cluster-based analyses, and multivariable linear regression to examine differences associated with insulin resistance. Of 110 metabolites tested, 91 significantly changed with OGTT (P ≤ 0.0005 for all). Amino acids, β-hydroxybutyrate, and tricarboxylic acid cycle intermediates decreased after OGTT, and glycolysis products increased, consistent with physiological insulin actions. Other pathways affected by OGTT included decreases in serotonin derivatives, urea cycle metabolites, and B vitamins. We also observed an increase in conjugated, and a decrease in unconjugated, bile acids. Changes in β-hydroxybutyrate, isoleucine, lactate, and pyridoxate were blunted in those with insulin resistance. Our findings demonstrate changes in 91 metabolites representing distinct biological pathways that are perturbed in response to an OGTT. We also identify metabolite responses that distinguish individuals with and without insulin resistance. These findings suggest that unique metabolic phenotypes can be unmasked by OGTT in the prediabetic state. PMID:23382451

  16. 76 FR 61098 - Guidance for 1-Hour SO2

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-03

    ...Notice is hereby given that the EPA has posted its draft non- binding guidance titled, ``Guidance for 1-Hour SO2 NAAQS SIP Submissions'' on its Web site. The EPA invites public comments on this guidance document during the comment period specified below, and plans to issue an updated version of the guidance after reviewing timely submitted...

  17. No differences in metabolic outcomes between nadir GH 0.4 and 1.0 ng/mL during OGTT in surgically cured acromegalic patients (observational study).

    PubMed

    Ku, Cheol Ryong; Choe, Eun Yeong; Hong, Jae Won; Kim, Eui Hyun; Park, Se Hee; Kim, Sun Ho; Lee, Eun Jig

    2016-06-01

    Metabolic impairment is the common cause for mortality in acromegalic patients. In this study, long-term improvements of metabolic parameters were evaluated according to 2 different remission criteria.This was an observational cohort study before and up to 1 year after transsphenoidal adenomectomy (TSA). Participants were 187 patients with acromegaly. At 6 months after TSA, remitted patients with age- and sex-matched normalized IGF-1 were divided into 2 groups: remission 1 (R1), nadir growth hormone (GH) below 0.4 ng/mL; and remission 2 (R2), nadir GH between 0.4 and 1.0 ng/mL in oral glucose tolerance test (OGTT). Metabolic parameters during serial OGTTs were evaluated for 12 months. Remission was achieved in 157 (R1-136; R2-21) patients. Immediate postoperative metabolic parameters including body weight, body mass index, glucose, insulin, and free fatty acid in OGTT were all significantly improved in R1 and R2. HOMA-%β and HOMA-IR scores also improved in both R1 and R2. These improvements persisted for duration (12 months) of this study. However, no difference was present in metabolic parameters between R1 and R2. Although the patients with preoperative adrenal insufficiency presented significantly increased HOMA scores before TSA, there was no difference between classifications of deficient pituitary axes and changes of metabolic parameters after TSA. Remitted patients exhibited rapid restoration of metabolic parameters immediate postoperative period. Long-term improvements in metabolic parameters were not different between the 2 different nadir GH cut-offs, 0.4 and 1.0 ng/mL. PMID:27310957

  18. Genetic polymorphisms of PCSK2 are associated with glucose homeostasis and progression to type 2 diabetes in a Chinese population

    PubMed Central

    Chang, Tien-Jyun; Chiu, Yen-Feng; Sheu, Wayne H-H.; Shih, Kuang-Chung; Hwu, Chii-Min; Quertermous, Thomas; Jou, Yuh-Shan; Kuo, Shan-Shan; Chang, Yi-Cheng; Chuang, Lee-Ming

    2015-01-01

    Proprotein convertase subtilisin/kexin type 2 (PCSK2) is a prohormone processing enzyme involved in insulin and glucagon biosynthesis. We previously found the genetic polymorphism of PCSK2 on chromosome 20 was responsible for the linkage peak of several glucose homeostasis parameters. The aim of this study is to investigate the association between genetic variants of PCSK2 and glucose homeostasis parameters and incident diabetes. Total 1142 Chinese participants were recruited from the Stanford Asia-Pacific Program for Hypertension and Insulin Resistance (SAPPHIRe) family study, and 759 participants were followed up for 5 years. Ten SNPs of the PCSK2 gene were genotyped. Variants of rs6044695 and rs2284912 were associated with fasting plasma glucose, and variants of rs2269023 were associated with fasting plasma glucose and 1-hour plasma glucose during OGTT. Haplotypes of rs4814605/rs1078199 were associated with fasting plasma insulin levels and HOMA-IR. Haplotypes of rs890609/rs2269023 were also associated with fasting plasma glucose, fasting insulin and HOMA-IR. In the longitudinal study, we found individuals carrying TA/AA genotypes of rs6044695 or TC/CC genotypes of rs2284912 had lower incidence of diabetes during the 5-year follow-up. Our results indicated that PCSK2 gene polymorphisms are associated with pleiotropic effects on various traits of glucose homeostasis and incident diabetes. PMID:26607656

  19. The relationship of plasma glucose and electrocardiographic parameters in elderly women with different degrees of glucose tolerance.

    PubMed

    Solini, A; Passaro, A; D'Elia, K; Calzoni, F; Alberti, L; Fellin, R

    2000-08-01

    Plasma glucose has been regarded as a risk factor for macrovascular complications in diabetes, but less is known about its role in the development of cardiac impairment other than coronary heart disease (CHD). The aim of our study was to determine the relationship between basal and post-OGTT (Oral Glucose Tolerance Test) plasma glucose levels and some ECG parameters in a group of elderly women with normal or impaired glucose tolerance (IGT). One-hundred and one women with normal fasting glucose (<6.0 mmol/L) and no familial history or clinical signs of CHD and diabetes underwent an OGTT and a resting ECG. Based on the degree of glucose tolerance, we identified 24 women with a diagnostic OGTT for either IGT or diabetes; the 77 women (age range 52-88 years) with normal glucose tolerance were further divided into two groups according to their post-OGTT area under the curve (AUCG): below and above the median value (32 and 45 women, respectively). Basal plasma glucose and insulin levels, as well as lipid profile and percent of hypertensive patients were similar in the three groups. Mean corrected QT (QTc) was prolonged as a function of progressive worsening of glucose tolerance even after adjustment for possible confounding factors (p=0.03). A similar relationship was apparent when post-OGTT plasma glucose peak (GP) was considered. In a multiple regression analysis, AUCG and GP were the only factors independently related to both QTc and Sokolow index. Our observations suggest that, even in the presence of a normal glucose tolerance, plasma glucose concentrations during an OGTT are associated with peculiar ECG signs potentially combined with an increased risk of sudden death, arrhythmias, or cardiovascular mortality. PMID:11073343

  20. The relationship between glycated hemoglobin and blood glucose levels of 75 and 100 gram oral glucose tolerance test during gestational diabetes diagnosis

    PubMed Central

    Mert, Meral; Purcu, Serhat; Soyluk, Ozlem; Okuturlar, Yildiz; Karakaya, Pinar; Tamer, Gonca; Adas, Mine; Ekin, Murat; Hatipoglu, Sami; Ure, Oznur Sari; Harmankaya, Ozlem; Kumbasar, Abdulbaki

    2015-01-01

    Objective: The diagnosis of gestational diabetes mellitus (GDM) is an important issue in terms of prevention of maternal and fetal complications. In our study we aimed to evaluate the relation of HbA1c and blood glucose levels of 75 and 50-100 gram oral glucose tolerance test (OGTT) in pregnant patients who were screened for GDM. Materials and methods: The parameters of 913 pregnant women screened for GDM are evaluated retrospectively. The two steps screening with 50-100 gram OGTT were used in 576 patients. The remaining 337 patients were screened with 75 gram OGTT. Results: The HbA1c levels of patients having high blood glucose (≥153 mg/dl) levels at 2nd hour in 75 gram OGTT were significantly higher than patients having normal blood glucose levels at 2nd hour of 75 gram OGTT (P=0.038). Correlation analyses showed no significant relation between any blood glucose level of 100 gram OGTT and HbA1c level. Whereas in 75 gram OGTT 1st and 2nd hour blood glucose levels were found to have a significant relation with A1c levels (P=0.001, P=0.001 respectively). Conclusion: HbA1c may be used as an important tool in the diagnosis of GDM. But due to the variation of HbA1c in pregnant women and there is not an absolute cut-off level for A1c, it may be more reliable to evaluate HbA1c level together with the blood glucose levels in OGTT. PMID:26550262

  1. Exercise Intensity Modulates Glucose-Stimulated Insulin Secretion when Adjusted for Adipose, Liver and Skeletal Muscle Insulin Resistance

    PubMed Central

    Malin, Steven K.; Rynders, Corey A.; Weltman, Judy Y.; Barrett, Eugene J.; Weltman, Arthur

    2016-01-01

    Little is known about the effects of exercise intensity on compensatory changes in glucose-stimulated insulin secretion (GSIS) when adjusted for adipose, liver and skeletal muscle insulin resistance (IR). Fifteen participants (8F, Age: 49.9±3.6yr; BMI: 31.0±1.5kg/m2; VO2peak: 23.2±1.2mg/kg/min) with prediabetes (ADA criteria, 75g OGTT and/or HbA1c) underwent a time-course matched Control, and isocaloric (200kcal) exercise at moderate (MIE; at lactate threshold (LT)), and high-intensity (HIE; 75% of difference between LT and VO2peak). A 75g OGTT was conducted 1 hour post-exercise/Control, and plasma glucose, insulin, C-peptide and free fatty acids were determined for calculations of skeletal muscle (1/Oral Minimal Model; SMIR), hepatic (HOMAIR), and adipose (ADIPOSEIR) IR. Insulin secretion rates were determined by deconvolution modeling for GSIS, and disposition index (DI; GSIS/IR; DISMIR, DIHOMAIR, DIADIPOSEIR) calculations. Compared to Control, exercise lowered SMIR independent of intensity (P<0.05), with HIE raising HOMAIR and ADIPOSEIR compared with Control (P<0.05). GSIS was not reduced following exercise, but DIHOMAIR and DIADIPOSEIR were lowered more following HIE compared with Control (P<0.05). However, DISMIR increased in an intensity based manner relative to Control (P<0.05), which corresponded with lower post-prandial blood glucose levels. Taken together, pancreatic insulin secretion adjusts in an exercise intensity dependent manner to match the level of insulin resistance in skeletal muscle, liver and adipose tissue. Further work is warranted to understand the mechanism by which exercise influences the cross-talk between tissues that regulate blood glucose in people with prediabetes. PMID:27111219

  2. 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

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

    PubMed

    Philippe, M; Krüsmann, P J; Mersa, L; Eder, E M; Gatterer, H; Melmer, A; Ebenbichler, C; Burtscher, M

    2016-06-01

    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

  4. Association between blood glucose level derived using the oral glucose tolerance test and glycated hemoglobin level

    PubMed Central

    Kim, Hyoung Joo; Kim, Young Geon; Park, Jin Soo; Ahn, Young Hwan; Ha, Kyoung Hwa; Kim, Dae Jung

    2016-01-01

    Background/Aims: Glycated hemoglobin (HbA1c) is widely used as a marker of glycemic control. Translation of the HbA1c level to an average blood glucose level is useful because the latter figure is easily understood by patients. We studied the association between blood glucose levels revealed by the oral glucose tolerance test (OGTT) and HbA1c levels in a Korean population. Methods: A total of 1,000 subjects aged 30 to 64 years from the Cardiovascular and Metabolic Diseases Etiology Research Center cohort were included. Fasting glucose levels, post-load glucose levels at 30, 60, and 120 minutes into the OGTT, and HbA1c levels were measured. Results: Linear regression of HbA1c with mean blood glucose levels derived using the OGTT revealed a significant correlation between these measures (predicted mean glucose [mg/dL] = 49.4 × HbA1c [%] − 149.6; R2 = 0.54, p < 0.001). Our linear regression equation was quite different from that of the Alc-Derived Average Glucose (ADAG) study and Diabetes Control and Complications Trial (DCCT) cohort. Conclusions: Discrepancies between our results and those of the ADAG study and DCCT cohort may be attributable to differences in the test methods used and the extent of insulin secretion. More studies are needed to evaluate the association between HbA1c and self monitoring blood glucose levels. PMID:26898598

  5. Establishment of a Refined Oral Glucose Tolerance Test in Pigs, and Assessment of Insulin, Glucagon and Glucagon-Like Peptide-1 Responses

    PubMed Central

    Manell, Elin; Hedenqvist, Patricia; Svensson, Anna; Jensen-Waern, Marianne

    2016-01-01

    Diabetes mellitus is increasing worldwide and reliable animal models are important for progression of the research field. The pig is a commonly used large animal model in diabetes research and the present study aimed to refine a model for oral glucose tolerance test (OGTT) in young growing pigs, as well as describing intravenous glucose tolerance test (IVGTT) in the same age group. The refined porcine OGTT will reflect that used in children and adolescents. Eighteen pigs were obtained one week after weaning and trained for two weeks to bottle-feed glucose solution, mimicking the human OGTT. The pigs subsequently underwent OGTT (1.75 g/kg BW) and IVGTT (0.5 g/kg BW). Blood samples were collected from indwelling vein catheters for measurements of glucose and the diabetes related hormones insulin, glucagon and active glucagon-like peptide-1. The study confirmed that pigs can be trained to bottle-feed glucose dissolved in water and thereby undergo an OGTT more similar to the human standard OGTT than previously described methods in pigs. With the refined method for OGTT, oral intake only consists of glucose and water, which is an advantage over previously described methods in pigs where glucose is given together with feed which will affect glucose absorption. Patterns of hormonal secretion in response to oral and intravenous glucose were similar to those in humans; however, the pigs were more glucose tolerant with lower insulin levels than humans. In translational medicine, this refined OGTT and IVGTT methods provide important tools in diabetes research when pigs are used as models for children and adolescents in diabetes research. PMID:26859145

  6. Establishment of a Refined Oral Glucose Tolerance Test in Pigs, and Assessment of Insulin, Glucagon and Glucagon-Like Peptide-1 Responses.

    PubMed

    Manell, Elin; Hedenqvist, Patricia; Svensson, Anna; Jensen-Waern, Marianne

    2016-01-01

    Diabetes mellitus is increasing worldwide and reliable animal models are important for progression of the research field. The pig is a commonly used large animal model in diabetes research and the present study aimed to refine a model for oral glucose tolerance test (OGTT) in young growing pigs, as well as describing intravenous glucose tolerance test (IVGTT) in the same age group. The refined porcine OGTT will reflect that used in children and adolescents. Eighteen pigs were obtained one week after weaning and trained for two weeks to bottle-feed glucose solution, mimicking the human OGTT. The pigs subsequently underwent OGTT (1.75 g/kg BW) and IVGTT (0.5 g/kg BW). Blood samples were collected from indwelling vein catheters for measurements of glucose and the diabetes related hormones insulin, glucagon and active glucagon-like peptide-1. The study confirmed that pigs can be trained to bottle-feed glucose dissolved in water and thereby undergo an OGTT more similar to the human standard OGTT than previously described methods in pigs. With the refined method for OGTT, oral intake only consists of glucose and water, which is an advantage over previously described methods in pigs where glucose is given together with feed which will affect glucose absorption. Patterns of hormonal secretion in response to oral and intravenous glucose were similar to those in humans; however, the pigs were more glucose tolerant with lower insulin levels than humans. In translational medicine, this refined OGTT and IVGTT methods provide important tools in diabetes research when pigs are used as models for children and adolescents in diabetes research. PMID:26859145

  7. [Study of causes of untoward reactions of the glucose tolerance test].

    PubMed

    Fan, L F

    1994-07-01

    The observation of the Side-effects and influent factores after 75g OGTT indioated that the aotal rate of side-effects was 52.43%. After OGTT the commonest side-effect was vomiting. Others were dizzy and palpitation. The side-effects were also related to age, sex, starvation, speed of taking glucose water, water volum of dissolving glucose, gastrointestinal diseases, blood glucose level, etc. It was recommended in this paper that the speed of taking glucose water should be 3-5 minutes, the water temperature below 40 degrees C and starvation about 14 hours. PMID:7614609

  8. Impaired glucose utilization in man during acute exposure to environmental heat.

    PubMed

    Tatár, P; Vigas, M; Jurcovicová, J; Jezová, D; Strec, V; Palát, M

    1985-12-01

    In 6 healthy males the oral glucose tolerance test (OGTT) was performed after the administration of 100 g glucose during the hyperthermic Finnish sauna bath (85 degrees C) of 30 min duration. The lowered insulin response (P less than 0.001) to glucose challenge during heating and the subsequent prolonged hyperglycemia (P less than 0.001) after heating were observed, when compared to OGTT under thermoneutral conditions (23 degrees C). It is suggested that the heat-induced decrease in visceral blood flow and stimulation of sympathoadrenomedullary and pituitary activity may be responsible for this effect. PMID:3910408

  9. The Role of Untimed Blood Glucose in Screening for Gestational Diabetes Mellitus in a High Prevalent Diabetic Population

    PubMed Central

    Cuschieri, Sarah; Craus, Johann; Savona-Ventura, Charles

    2016-01-01

    Global prevalence increase of diabetes type 2 and gestational diabetes (GDM) has led to increased awareness and screening of pregnant women for GDM. Ideally screening for GDM should be done by an oral glucose tolerance test (oGTT), which is laborious and time consuming. A randomized glucose test incorporated with anthropomorphic characteristics may be an appropriate cost-effective combined clinical and biochemical screening protocol for clinical practice as well as cutting down on oGTTs. A retrospective observational study was performed on a randomized sample of pregnant women who required an OGTT during their pregnancy. Biochemical and anthropomorphic data along with obstetric outcomes were statistically analyzed. Backward stepwise logistic regression and receiver operating characteristics curves were used to obtain a suitable predictor for GDM without an oGTT and formulate a screening protocol. Significant GDM predictive variables were fasting blood glucose (p = 0.0001) and random blood glucose (p = 0.012). Different RBG and FBG cutoff points with anthropomorphic characteristics were compared to carbohydrate metabolic status to diagnose GDM without oGTT, leading to a screening protocol. A screening protocol incorporating IADPSG diagnostic criteria, BMI, and different RBG and FBG criteria would help predict GDM among high-risk populations earlier and reduce the need for oGTT test. PMID:26998382

  10. 75 FR 6570 - Approval and Promulgation of Air Quality Implementation Plans; Louisiana; Baton Rouge 1-Hour...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-02-10

    ... and the 1-hour ozone rulemakings cited therein. See 70 FR 71612 (November 29, 2005) and in the cases... its interpretation and practice with respect to the 1-hour ozone standard. See Phase 2 Rule, 70 FR... rulemakings cited in the Phase 2 8-Hour Ozone Implementation Rule, 70 FR 71644-71646 (November 29, 2005)....

  11. Association Between Cardiorespiratory Fitness and the Determinants of Glycemic Control Across the Entire Glucose Tolerance Continuum

    PubMed Central

    Malin, Steven K.; Karstoft, Kristian; Knudsen, Sine H.; Haus, Jacob M.; Laye, Matthew J.; Kirwan, John P.

    2015-01-01

    OBJECTIVE Cardiorespiratory fitness (VO2max) is associated with glycemic control, yet the relationship between VO2max and the underlying determinants of glycemic control is less clear. Our aim was to determine whether VO2max is associated with insulin sensitivity, insulin secretion, and the disposition index, a measure of compensatory pancreatic β-cell insulin secretion relative to insulin sensitivity, in subjects representing the entire range of the glucose tolerance continuum. RESEARCH DESIGN AND METHODS A cohort of subjects (N = 313) with heterogeneous age, sex, BMI, and glycemic control underwent measurements of body composition, HbA1c, fasting glucose, oral glucose tolerance (OGTT), and VO2max. OGTT-derived insulin sensitivity (SiOGTT), glucose-stimulated insulin secretion (GSISOGTT), and the disposition index (DIOGTT) (the product of SiOGTT and GSISOGTT) were measured, and associations between VO2max and these determinants of glycemic control were examined. RESULTS A low VO2max was associated with high HbA1c (r = −0.33), high fasting glucose (r = −0.34), high 2-h OGTT glucose (r = −0.33), low SiOGTT (r = 0.73), and high early-phase (r = −0.34) and late-phase (r = −0.36) GSISOGTT. Furthermore, a low VO2max was associated with low early- and late-phase DIOGTT (both r = 0.41). Interestingly, relationships between VO2max and either glycemic control or late-phase GSISOGTT deteriorated across the glucose tolerance continuum. CONCLUSIONS The association between poor cardiorespiratory fitness and compromised pancreatic β-cell compensation across the entire glucose tolerance continuum provides additional evidence highlighting the importance of fitness in protection against the onset of a fundamental pathophysiological event that leads to type 2 diabetes. PMID:25784661

  12. The "lipid accumulation product" is associated with 2-hour postload glucose outcomes in overweight/obese subjects with nondiabetic fasting glucose.

    PubMed

    Malavazos, Alexis Elias; Cereda, Emanuele; Ermetici, Federica; Caccialanza, Riccardo; Briganti, Silvia; Rondanelli, Mariangela; Morricone, Lelio

    2015-01-01

    "Lipid accumulation product" (LAP) is a continuous variable based on waist circumference and triglyceride concentration previously associated with insulin resistance. We investigated the accuracy of LAP in identifying oral glucose tolerance test (OGTT) abnormalities and compared it to the homeostasis model assessment of insulin resistance (HOMA-IR) in a population of overweight/obese outpatients presenting with nondiabetic fasting glucose. We studied 381 (male: 23%) adult (age: 18-70 years) overweight/obese Caucasians (body mass index: 36.9 ± 5.4 Kg/m(2)) having fasting plasma glucose < 7.0 mmol/L. OGTT was used to diagnose unknown glucose tolerance abnormalities: impaired glucose tolerance (IGT) and type-2 diabetes mellitus (T2-DM). According to OGTT 92, subjects had an IGT and 33 were diagnosed T2-DM. Logistic regression analysis detected a significant association for both LAP and HOMA-IR with single (IGT and T2-DM) and composite (IGT + T2-DM) abnormal glucose tolerance conditions. However, while the association with diabetes was similar between LAP and HOMA-IR, the relationship with IGT and composite outcomes by models including LAP was significantly superior to those including HOMA-IR (P = 0.006 and P = 0.007, resp.). LAP seems to be an accurate index, performing better than HOMA-IR, for identifying 2-hour postload OGTT outcomes in overweight/obese patients with nondiabetic fasting glucose. PMID:25792981

  13. The “Lipid Accumulation Product” Is Associated with 2-Hour Postload Glucose Outcomes in Overweight/Obese Subjects with Nondiabetic Fasting Glucose

    PubMed Central

    Malavazos, Alexis Elias; Cereda, Emanuele; Ermetici, Federica; Caccialanza, Riccardo; Briganti, Silvia; Rondanelli, Mariangela; Morricone, Lelio

    2015-01-01

    “Lipid accumulation product” (LAP) is a continuous variable based on waist circumference and triglyceride concentration previously associated with insulin resistance. We investigated the accuracy of LAP in identifying oral glucose tolerance test (OGTT) abnormalities and compared it to the homeostasis model assessment of insulin resistance (HOMA-IR) in a population of overweight/obese outpatients presenting with nondiabetic fasting glucose. We studied 381 (male: 23%) adult (age: 18–70 years) overweight/obese Caucasians (body mass index: 36.9 ± 5.4 Kg/m2) having fasting plasma glucose < 7.0 mmol/L. OGTT was used to diagnose unknown glucose tolerance abnormalities: impaired glucose tolerance (IGT) and type-2 diabetes mellitus (T2-DM). According to OGTT 92, subjects had an IGT and 33 were diagnosed T2-DM. Logistic regression analysis detected a significant association for both LAP and HOMA-IR with single (IGT and T2-DM) and composite (IGT + T2-DM) abnormal glucose tolerance conditions. However, while the association with diabetes was similar between LAP and HOMA-IR, the relationship with IGT and composite outcomes by models including LAP was significantly superior to those including HOMA-IR (P = 0.006 and P = 0.007, resp.). LAP seems to be an accurate index, performing better than HOMA-IR, for identifying 2-hour postload OGTT outcomes in overweight/obese patients with nondiabetic fasting glucose. PMID:25792981

  14. Detecting Prediabetes and Diabetes: Agreement between Fasting Plasma Glucose and Oral Glucose Tolerance Test in Thai Adults

    PubMed Central

    Aekplakorn, Wichai; Tantayotai, Valla; Numsangkul, Sakawduan; Sripho, Wilarwan; Tatsato, Nutchanat; Burapasiriwat, Tuanjai; Pipatsart, Rachada; Sansom, Premsuree; Luckanajantachote, Pranee; Chawarokorn, Pongpat; Thanonghan, Anek; Lakhamkaew, Watchira; Mungkung, Aungsumalin; Boonkean, Rungnapa; Chantapoon, Chanidsa; Kungsri, Mayuree; Luanseng, Kasetsak; Chaiyajit, Kornsinun

    2015-01-01

    Aim. To evaluate an agreement in identifying dysglycemia between fasting plasma glucose (FPG) and the 2 hr postprandial glucose tolerance test (OGTT) in a population with high risk of diabetes. Methods. A total of 6,884 individuals aged 35–65 years recruited for a community-based diabetes prevention program were tested for prediabetes including impaired fasting glucose (IFG) or impaired glucose tolerance (IGT), and diabetes. The agreement was assessed by Kappa statistics. Logistic regression was used to examine factors associated with missed prediabetes and diabetes by FPG. Results. A total of 2671 (38.8%) individuals with prediabetes were identified. The prevalence of prediabetes identified by FPG and OGTT was 32.2% and 22.3%, respectively. The proportions of diabetes classified by OGTT were two times higher than those identified by FPG (11.0% versus 5.4%, resp.). The Kappa statistics for agreement of both tests was 0.55. Overall, FPG missed 46.3% of all prediabetes and 54.7% of all diabetes cases. Prediabetes was more likely to be missed by FPG among female, people aged <45 yrs, and those without family history of diabetes. Conclusion. The detection of prediabetes and diabetes using FPG only may miss half of the cases. Benefit of adding OGTT to FPG in some specific groups should be confirmed. PMID:26347060

  15. Serum Galanin Levels in Young Healthy Lean and Obese Non-Diabetic Men during an Oral Glucose Tolerance Test.

    PubMed

    Sandoval-Alzate, Héctor Fabio; Agudelo-Zapata, Yessica; González-Clavijo, Angélica María; Poveda, Natalia E; Espinel-Pachón, Cristian Felipe; Escamilla-Castro, Jorge Augusto; Márquez-Julio, Heidy Lorena; Alvarado-Quintero, Hernando; Rojas-Rodríguez, Fabián Guillermo; Arteaga-Díaz, Juan Manuel; Eslava-Schmalbach, Javier Hernando; Garcés-Gutiérrez, Maria Fernanda; Vrontakis, Maria; Castaño, Justo P; Luque, Raul M; Diéguez, Carlos; Nogueiras, Rubén; Caminos, Jorge E

    2016-01-01

    Galanin (GAL) is a neuropeptide involved in the homeostasis of energy metabolism. The objective of this study was to investigate the serum levels of GAL during an oral glucose tolerance test (OGTT) in lean and obese young men. This cross-sectional study included 30 obese non-diabetic young men (median 22 years; mean BMI 37 kg/m(2)) and 30 healthy lean men (median 23 years; mean BMI 22 kg/m(2)). Serum GAL was determined during OGTT. The results of this study include that serum GAL levels showed a reduction during OGTT compared with basal levels in the lean subjects group. Conversely, serum GAL levels increased significantly during OGTT in obese subjects. Serum GAL levels were also higher in obese non-diabetic men compared with lean subjects during fasting and in every period of the OGTT (p < 0.001). Serum GAL levels were positively correlated with BMI, total fat, visceral fat, HOMA-IR, total cholesterol, triglycerides and Leptin. A multiple regression analysis revealed that serum insulin levels at 30, 60 and 120 minutes during the OGTT is the most predictive variable for serum GAL levels (p < 0.001). In conclusion, serum GAL levels are significantly higher in the obese group compared with lean subjects during an OGTT. PMID:27550417

  16. Serum Galanin Levels in Young Healthy Lean and Obese Non-Diabetic Men during an Oral Glucose Tolerance Test

    PubMed Central

    Sandoval-Alzate, Héctor Fabio; Agudelo-Zapata, Yessica; González-Clavijo, Angélica María; Poveda, Natalia E.; Espinel-Pachón, Cristian Felipe; Escamilla-Castro, Jorge Augusto; Márquez-Julio, Heidy Lorena; Alvarado-Quintero, Hernando; Rojas-Rodríguez, Fabián Guillermo; Arteaga-Díaz, Juan Manuel; Eslava-Schmalbach, Javier Hernando; Garcés-Gutiérrez, Maria Fernanda; Vrontakis, Maria; Castaño, Justo P.; Luque, Raul M.; Diéguez, Carlos; Nogueiras, Rubén; Caminos, Jorge E.

    2016-01-01

    Galanin (GAL) is a neuropeptide involved in the homeostasis of energy metabolism. The objective of this study was to investigate the serum levels of GAL during an oral glucose tolerance test (OGTT) in lean and obese young men. This cross-sectional study included 30 obese non-diabetic young men (median 22 years; mean BMI 37 kg/m2) and 30 healthy lean men (median 23 years; mean BMI 22 kg/m2). Serum GAL was determined during OGTT. The results of this study include that serum GAL levels showed a reduction during OGTT compared with basal levels in the lean subjects group. Conversely, serum GAL levels increased significantly during OGTT in obese subjects. Serum GAL levels were also higher in obese non-diabetic men compared with lean subjects during fasting and in every period of the OGTT (p < 0.001). Serum GAL levels were positively correlated with BMI, total fat, visceral fat, HOMA–IR, total cholesterol, triglycerides and Leptin. A multiple regression analysis revealed that serum insulin levels at 30, 60 and 120 minutes during the OGTT is the most predictive variable for serum GAL levels (p < 0.001). In conclusion, serum GAL levels are significantly higher in the obese group compared with lean subjects during an OGTT. PMID:27550417

  17. beta-Cell function and insulin sensitivity in adolescents from an OGTT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Given the increase in the incidence of insulin resistance, obesity, and type 2 diabetes in children and adolescents, it would be of paramount importance to assess quantitative indices of insulin secretion and action during a physiological perturbation, such as a meal or an oral glucose-tolerance tes...

  18. Validation of Point-of-Care Glucose Testing for Diagnosis of Type 2 Diabetes

    PubMed Central

    Božičević, Sandra; Pape-Medvidović, Edita; Ljubić, Spomenka

    2013-01-01

    Point-of-care (POC) glucose technology is currently considered to be insufficiently accurate for the diagnosis of diabetes. The objective of this study was to investigate the diagnostic accuracy of an innovative, interference-resistant POC glucose meter (StatStrip glucose hospital meter, Nova Biomedical, USA) in subjects with a previous history of dysglycaemia, undergoing a 75 g diagnostic oral glucose tolerance test (oGTT). Venous and capillary blood sampling for the reference laboratory procedure (RLP) and POC-glucose measurement was carried out at fasting and 2 h oGTT, and categories of glucose tolerance were classified according to 2006 WHO diagnostic criteria for the respective sample type. We found an excellent between-method correlation at fasting (r = 0.9681, P < 0.0001) and 2 h oGTT (r = 0.9768, P < 0.0001) and an almost perfect diagnostic agreement (weighted Kappa = 0.858). Within a total of 237 study subjects, 137 were diagnosed with diabetes with RLP, and only 6 of them were reclassified as having glucose intolerance with POC. The diagnostic performance of POC-fasting glucose in discriminating between the normal and any category of disturbed glucose tolerance did not differ from the RLP (P = 0.081). Results of this study indicate that StatStrip POC glucose meter could serve as a reliable tool for the diabetes diagnosis, particularly in primary healthcare facilities with dispersed blood sampling services. PMID:24382960

  19. Urinary N-acetyl-β-d-Glucosaminidase Levels are Positively Correlated With 2-Hr Plasma Glucose Levels During Oral Glucose Tolerance Testing in Prediabetes

    PubMed Central

    Ouchi, Motoshi; Suzuki, Tatsuya; Hashimoto, Masao; Motoyama, Masayuki; Ohara, Makoto; Suzuki, Kazunari; Igari, Yoshimasa; Watanabe, Kentaro; Nakano, Hiroshi; Oba, Kenzo

    2012-01-01

    Background Urinary N-acetyl-β-D-glucosaminidase (NAG) excretion is increased in patients with impaired glucose tolerance (IGT). This study investigated when during the oral glucose tolerance test (OGTT) the plasma glucose, urine glucose, and insulin levels correlate most strongly with urinary N-acetyl-β-d-glucosaminidase (NAG) levels in prediabetic subjects. Methods The OGTT was administered to 80 subjects who had not yet received a diagnosis of diabetes mellitus (DM) and in whom HbA1c levels were ≤6.8% and fasting plasma glucose levels were <7.0 mmol/l. Forty-two subjects had normal glucose tolerance (NGT), 31 had impaired glucose tolerance (IGT), and 7 had DM according to World Health Organization criteria. Serum levels of cystatin C, the estimated glomerular filtration rate, the urinary albumin-to-creatinine (Cr) ratio, urinary and serum β2-microglobulin, and urinary NAG were measured as markers of renal function. Results NAG levels were significantly higher in subjects with DM and in subjects with IGT than in subjects with NGT. No significant associations were observed between glycemic status and other markers of renal function. Multiple linear regression analysis showed that the NAG level was positively correlated with plasma glucose levels at 120 min of the OGTT and was associated with the glycemic status of prediabetic patients. Conclusion These results suggest that postprandial hyperglycemia is an independent factor that causes renal tubular damage in prediabetes patients. PMID:23143631

  20. Aerosolized Red Tide Toxins (Brevetoxins) and Asthma: Continued health effects after 1 hour beach exposure

    PubMed Central

    Kirkpatrick, Barbara; Fleming, Lora E; Bean, Judy A; Nierenberg, Kate; Backer, Lorraine C; Cheng, Yung Sung; Pierce, Richard; Reich, Andrew; Naar, Jerome; Wanner, Adam; Abraham, William M; Zhou, Yue; Hollenbeck, Julie; Baden, Daniel G

    2010-01-01

    Blooms of the toxic dinoflagellate, Karenia brevis, produce potent neurotoxins in marine aerosols. Recent studies have demonstrated acute changes in both symptoms and pulmonary function in asthmatics after only 1 hour of beach exposure to these aerosols. This study investigated if there were latent and/or sustained effects in asthmatics in the days following the initial beach exposure during periods with and without an active Florida red tide. Symptom data and spirometry data were collected before and after 1 hour of beach exposure. Subjects kept daily symptom diaries and measured their peak flow each morning for 5 days following beach exposure. During non-exposure periods, there were no significant changes in symptoms or pulmonary function either acutely or over 5 days of follow-up. After the beach exposure during an active Florida red tide, subjects had elevated mean symptoms which did not return to the pre-exposure baseline for at least 4 days. The peak flow measurements decreased after the initial beach exposure, decreased further within 24 hours, and continued to be suppressed even after 5 days. Asthmatics may continue to have increased symptoms and delayed respiratory function suppression for several days after 1 hour of exposure to the Florida red tide toxin aerosols. PMID:21499552

  1. Aerosolized Red Tide Toxins (Brevetoxins) and Asthma: Continued health effects after 1 hour beach exposure.

    PubMed

    Kirkpatrick, Barbara; Fleming, Lora E; Bean, Judy A; Nierenberg, Kate; Backer, Lorraine C; Cheng, Yung Sung; Pierce, Richard; Reich, Andrew; Naar, Jerome; Wanner, Adam; Abraham, William M; Zhou, Yue; Hollenbeck, Julie; Baden, Daniel G

    2011-01-01

    Blooms of the toxic dinoflagellate, Karenia brevis, produce potent neurotoxins in marine aerosols. Recent studies have demonstrated acute changes in both symptoms and pulmonary function in asthmatics after only 1 hour of beach exposure to these aerosols. This study investigated if there were latent and/or sustained effects in asthmatics in the days following the initial beach exposure during periods with and without an active Florida red tide.Symptom data and spirometry data were collected before and after 1 hour of beach exposure. Subjects kept daily symptom diaries and measured their peak flow each morning for 5 days following beach exposure. During non-exposure periods, there were no significant changes in symptoms or pulmonary function either acutely or over 5 days of follow-up. After the beach exposure during an active Florida red tide, subjects had elevated mean symptoms which did not return to the pre-exposure baseline for at least 4 days. The peak flow measurements decreased after the initial beach exposure, decreased further within 24 hours, and continued to be suppressed even after 5 days. Asthmatics may continue to have increased symptoms and delayed respiratory function suppression for several days after 1 hour of exposure to the Florida red tide toxin aerosols. PMID:21499552

  2. Beta-cell function, incretin effect, and incretin hormones in obese youth along the span of glucose tolerance from normal to prediabetes to Type 2 diabetes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Using the hyperglycemic and euglycemic clamp, we demonstrated impaired Beta-cell function in obese youth with increasing dysglycemia. Herein we describe oral glucose tolerance test (OGTT)-modeled Beta-cell function and incretin effect in obese adolescents spanning the range of glucose tolerance. Bet...

  3. Glucose metabolism in obese and lean adolescents with polycystic ovary syndrome.

    PubMed

    Poomthavorn, Preamrudee; Chaya, Weerapong; Mahachoklertwattana, Pat; Sukprasert, Matchuporn; Weerakiet, Sawaek

    2013-01-01

    Data on glucose metabolism in Asian adolescents with polycystic ovary syndrome (PCOS) are limited. Glucose metabolism assessment using an oral glucose tolerance test (OGTT) in obese and lean Thai adolescents with PCOS, and a comparison between the two groups were done. Thirty-one patients (19 obese, 12 lean) were enrolled. Their median (range) age was 14.9 (11.0-21.0) years. Eighteen patients had abnormal glucose metabolism (13 hyperinsulinemia, 4 impaired glucose tolerance, and 1 diabetes). Compared between obese [median (range) BMI Z-score, 1.6 (1.2-2.6)] and lean [median (range) BMI Z-score, 0.1 (-1.4 to 0.6)] patients, the frequencies of each abnormal OGTT category, areas under the curves of glucose and insulin levels, and insulinogenic index were not different; however, insulin resistance was greater in the obese group. In conclusion, a high proportion of our adolescents with PCOS had abnormal glucose metabolism. Therefore, OGTT should be performed in adolescents with PCOS for the early detection of abnormal glucose metabolism. PMID:23314524

  4. Acute Inactivity Impairs Glycemic Control but Not Blood Flow to Glucose Ingestion

    PubMed Central

    Reynolds, Leryn J; Credeur, Daniel P; Holwerda, Seth W; Leidy, Heather J; Fadel, Paul J; Thyfault, John P

    2014-01-01

    Purpose Insulin-stimulated increases in skeletal muscle blood flow play a role in glucose disposal. Indeed, 7 days of aerobic exercise in type 2 diabetes patients increased blood flow responses to an oral glucose tolerance test (OGTT) and improved glucose tolerance. More recent work suggests that reduced daily physical activity impairs glycemic control (GC) in healthy individuals. Herein, we sought to determine if an acute reduction in daily activity (from >10,000 to <5,000 steps/day) for 5 days (RA5) in healthy individuals reduced insulin-stimulated blood flow and GC in parallel and if a 1 day return to activity (RTA1) improved these outcomes. Methods OGTTs were performed as a stimulus to increase insulin in 14 healthy, recreationally active men (24±1.1 yrs) at baseline, RA5, and RTA1. Measures of insulin sensitivity (Matsuda index) and femoral and brachial artery blood flow were made during the OGTT. Free living measures of GC including peak postprandial glucose (peak PPG) were also made via continuous glucose monitoring. Results Femoral and brachial artery blood flow increased during the OGTT but neither was significantly impacted by changes in physical activity (p>0.05). However, insulin sensitivity was decreased by RA5 (11.3±1.5 to 8.0±1.0; p<0.05). Likewise, free living GC measures of peak post prandial blood glucose (113±3 to 123±5 mg/dL; p<0.05) was significantly increased at RA5. Interestingly, insulin sensitivity and GC as assessed by peak PPG were not restored after RTA1 (p>0.05). Conclusions Thus, acute reductions in physical activity impaired GC and insulin sensitivity; however blood flow responses to an OGTT were not affected. Further, a 1 day return to activity was not sufficient to normalize GC following 5 days of reduced daily physical activity. PMID:25207931

  5. Multi-instrument overview of the 1-hour pulsations in Saturn's magnetosphere and auroral emissions (invited)

    NASA Astrophysics Data System (ADS)

    Palmaerts, Benjamin; Roussos, Elias; Radioti, Aikaterini; Krupp, Norbert; Grodent, Denis; Kurth, William S.; Yates, Japheth N.

    2016-04-01

    The in-situ exploration of the magnetospheres of Jupiter and Saturn has revealed different periodic processes which differ from the rotation period. In particular, in the Saturnian magnetosphere, several studies have reported pulsations in the outer magnetosphere with a periodicity of about 1 hour in the measurements of charged particle fluxes, plasma wave, magnetic field strength and auroral emission brightness. We made a 10-year survey of the quasi-periodic 1-hour energetic electron injections observed in the Saturn's outer magnetosphere by the Low-Energy Magnetospheric Imaging Instrument (MIMI/LEMMS) on board Cassini. The signature of these injections is pulsations in the electron fluxes at energies between a hundred keV up to several MeV. We investigated the topology and the morphology of these pulsations, as well as the signatures of the electron injections in the radio emissions and the magnetic field, respectively, measured by the Radio and Plasma Wave Science (RPWS) instrument and the magnetometer (MAG) on board Cassini. The morphology of the pulsations (interpulse period, number of pulsations per event, growth and decay time) shows a weak local time dependence, which suggests a high-latitude source for the pulsed energetic electrons. This suggestion is reinforced by the observation of strong radio bursts in the auroral hiss coincident with the electron pulsations and by the higher growth rate and decay rate magnitudes at high latitudes. Moreover, since the morphological properties of the pulsations are similar at the various locations where the electron injections are observed, the acceleration mechanism of the electrons is likely common for all the events and may be directly or indirectly involving magnetic reconnection. The auroral emissions, which display the ionospheric response to magnetospheric dynamics, exhibit some quasi-periodic 1-hour pulsations as well. Some pulsed auroral brightenings are observed while Cassini detects several electron

  6. Pre-Type 1 Diabetes Dysmetabolism: Maximal sensitivity achieved with Both Oral and Intravenous Glucose Tolerance Testing

    PubMed Central

    Barker, Jennifer M.; McFann, Kim; Harrison, Leonard C.; Fourlanos, Spiros; Krischer, Jeffrey; Cuthbertson, David; Chase, H. Peter; Eisenbarth, George S.; Group, the DPT-1 Study

    2007-01-01

    Objective To determine the relationship of intravenous (IVGTT) and oral (OGTT) glucose tolerance tests abnormalities to diabetes development in a high-risk pre-diabetic cohort and identify an optimal testing strategy for detecting pre-clinical diabetes. Study design Diabetes Prevention Trial Type 1 randomized subjects to oral (n=372) and parenteral (n=339) insulin prevention trials. Subjects were followed with IVGTTs and OGTTs. Factors associated with progression to diabetes were evaluated. Results Survival analysis revealed that higher quartiles of 2-hour glucose and lower quartiles of FPIR at baseline were associated with decreased diabetes-free survival. Cox proportional hazards modeling showed that baseline BMI, FPIR and 2-hour glucose levels were significantly associated with an increased hazard for diabetes. On testing performed within 6 months of diabetes diagnosis, 3% (1/32) had normal first phase insulin response (FPIR) and normal 2-hour glucose on OGTT. The sensitivities for impaired glucose tolerance (IGT) and low FPIR performed within 6 months of diabetes diagnosis were equivalent (76% vs. 73%). Conclusions Most (97%) subjects had abnormal IVGTTs and/or OGTTs prior to the development of diabetes. The highest sensitivity is achieved using both tests. PMID:17188609

  7. Abnormal transient rise in hepatic glucose production after oral glucose in non-insulin-dependent diabetic subjects.

    PubMed

    Thorburn, A; Litchfield, A; Fabris, S; Proietto, J

    1995-05-01

    A transient rise in hepatic glucose production (HGP) after an oral glucosa load has been reported in some insulin-resistant states such as in obese fa/fa Zucker rats. The aim of this study was to determine whether this rise in HGP also occurs in subjects with established non-insulin-dependent diabetes mellitus (NIDDM). Glucose kinetics were measured basally and during a double-label oral glucose tolerance test (OGTT) in 12 NIDDM subjects and 12 non-diabetic 'control' subjects. Twenty minutes after the glucose load, HGP had increased 73% above basal in the NIDDM subjects (7.29 +/- 0.52 to 12.58 +/- 1.86 mumol/kg/min, P < 0.02). A transient rise in glucagon (12 pg/ml above basal, P < 0.004) occurred at a similar time. In contrast, the control subjects showed no rise in HGP or plasma glucagon. HGP began to suppress 40-50 min after the OGTT in both the NIDDM and control subjects. A 27% increase in the rate of gut-derived glucose absorption was also observed in the NIDDM group, which could be the result of increased gut glucose absorption or decreased first pass extraction of glucose by the liver. Therefore, in agreement with data in animal models of NIDDM, a transient rise in HGP partly contributes to the hyperglycemia observed after an oral glucose load in NIDDM subjects. PMID:7587920

  8. Oral Glucose Tolerance Testing identifies HIV+ infected women with Diabetes Mellitus (DM) not captured by standard DM definition

    PubMed Central

    Tian, Fang; Anastos, Kathryn; Cohen, Mardge H; Tien, Phyllis C

    2016-01-01

    Objective HIV-infected (HIV+) individuals may have differential risk of diabetes mellitus (DM) compared to the general population, and the optimal diagnostic algorithm for DM in HIV+ persons remains unclear. We aimed to assess the utility of oral glucose tolerance testing (OGTT) for DM diagnosis in a cohort of women with or at risk for HIV infection. Methods Using American Diabetic Association DM definitions, DM prevalence and incidence were assessed among women enrolled in the Women’s Interagency HIV Study. DM was defined by 2-hour OGTT ≥ 200 mg/dL (DM_OGTT) or a clinical definition (DM_C) that included any of the following: (i) anti-diabetic medication use or self-reported DM confirmed by either fasting glucose (FG) ≥126 mg/dL or HbA1c ≥ 6.5%, (ii) FG ≥ 126 mg/dL confirmed by a second FG ≥ 126 mg/dL or HbA1c 6.5%, or (iii) HbA1c 6.5% confirmed by FG ≥ 126 mg/dL cohort. Results Overall, 390 women (285 HIV+, median age 43 years; 105 HIV−, median age 37 years) were enrolled between 2003-2006. Over half of all women were African American. Using DM_C, DM prevalence rates were 5.6% and 2.8% among HIV+ and HIV− women, respectively. Among HIV+ women, adding DM_OGTT to DM_C increased DM prevalence from 5.6% to 7.4%, a 31% increase in the number of diabetes cases diagnosed (p=0.02). In HIV− women, no additional cases were diagnosed by DM-OGTT. Conclusion In HIV+ women, OGTT identified DM cases that were not identified by a standardized clinical definition. Further investigation is needed to determine whether OGTT should be considered as an adjunctive tool for DM diagnosis in the setting of HIV infection. PMID:27066296

  9. Amino acid mixture acutely improves the glucose tolerance of healthy overweight adults.

    PubMed

    Wang, Bei; Kammer, Lynne M; Ding, Zhenping; Lassiter, David G; Hwang, Jungyun; Nelson, Jeffrey L; Ivy, John L

    2012-01-01

    Certain amino acids have been reported to influence carbohydrate metabolism and blood glucose clearance, as well as improve the glucose tolerance in animal models. We hypothesized that an amino acid mixture consisting of isoleucine and 4 additional amino acids would improve the glucose response of healthy overweight men and women to an oral glucose tolerance test (OGTT). Twenty-two overweight healthy subjects completed 2 OGTTs after consuming 2 different test beverages. The amino acid mixture beverage (CHO/AA) consisted of 0.088 g cystine 2HCl, 0.043 g methionine, 0.086 g valine, 12.094 g isoleucine, 0.084 g leucine, and 100 g dextrose. The control beverage (CHO) consisted of 100 g dextrose only. Venous blood samples were drawn 10 minutes before the start of ingesting the drinks and 15, 30, 60, 120, and 180 minutes after the completion of the drinks. During the OGTT, the plasma glucose response for the CHO/AA treatment was significantly lower than that of the CHO treatment (P < .01), as was the plasma glucose area under the curve (CHO/AA 806 ± 31 mmol/L·3 hours vs CHO 942 ± 40 mmol/L·3 hours). Differences in plasma glucose between treatments occurred at 30, 60, 120, and 180 minutes after supplement ingestion. Plasma glucagon during the CHO/AA treatment was significantly higher than during the CHO treatment. However, there were no significant differences in plasma insulin or C-peptide responses between treatments. These results suggest that the amino acid mixture lowers the glucose response to an OGTT in healthy overweight subjects in an insulin-independent manner. PMID:22260861

  10. 77 FR 34810 - Determination of Failure To Attain by 2005 and Determination of Current Attainment of the 1-Hour...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-12

    ...EPA is issuing two separate and independent final determinations related to the Baltimore 1-hour ozone nonattainment area. First, EPA is determining that the Baltimore area previously failed to attain the 1-hour ozone National Ambient Air Quality Standard (NAAQS) by its applicable attainment deadline of November 15, 2005 (based on complete, quality-assured and certified ozone monitoring data......

  11. 77 FR 64036 - Determination of Attainment of the 1-Hour Ozone National Ambient Air Quality Standards in the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-10-18

    ...EPA is determining that the Sacramento Metro 1-hour ozone nonattainment area (Sacramento Metro Area) has attained the revoked National Ambient Air Quality Standard (1-hour ozone NAAQS or standard), and to exclude certain 2008 data caused by wildfire exceptional events. These air quality determinations were proposed in conjunction with a proposed determination to terminate the State of......

  12. 40 CFR 50.9 - National 1-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... ambient air quality standards for ozone. 50.9 Section 50.9 Protection of Environment ENVIRONMENTAL....9 National 1-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 1-hour primary and secondary ambient air quality standards for ozone measured by...

  13. 40 CFR 50.9 - National 1-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... ambient air quality standards for ozone. 50.9 Section 50.9 Protection of Environment ENVIRONMENTAL....9 National 1-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 1-hour primary and secondary ambient air quality standards for ozone measured by...

  14. 40 CFR 50.9 - National 1-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... ambient air quality standards for ozone. 50.9 Section 50.9 Protection of Environment ENVIRONMENTAL....9 National 1-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 1-hour primary and secondary ambient air quality standards for ozone measured by...

  15. 40 CFR 50.9 - National 1-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... ambient air quality standards for ozone. 50.9 Section 50.9 Protection of Environment ENVIRONMENTAL....9 National 1-hour primary and secondary ambient air quality standards for ozone. (a) The level of the national 1-hour primary and secondary ambient air quality standards for ozone measured by...

  16. Failure of Hyperglycemia and Hyperinsulinemia to Compensate for Impaired Metabolic Response to an Oral Glucose Load

    PubMed Central

    Hussain, M; Janghorbani, M; Schuette, S; Considine, RV; Chisholm, RL; Mather, KJ

    2014-01-01

    Objective To evaluate whether the augmented insulin and glucose response to a glucose challenge is sufficient to compensate for defects in glucose utilization in obesity and type 2 diabetes, using a breath test measurement of integrated glucose metabolism. Methods Non-obese, obese normoglycemic and obese Type 2 diabetic subjects were studied on 2 consecutive days. A 75g oral glucose load spiked with 13C-glucose was administered, measuring exhaled breath 13CO2 as an integrated measure of glucose metabolism and oxidation. A hyperinsulinemic euglycemic clamp was performed, measuring whole body glucose disposal rate. Body composition was measured by DEXA. Multivariable analyses were performed to evaluate the determinants of the breath 13CO2. Results Breath 13CO2 was reduced in obese and type 2 diabetic subjects despite hyperglycemia and hyperinsulinemia. The primary determinants of breath response were lean mass, fat mass, fasting FFA concentrations, and OGTT glucose excursion. Multiple approaches to analysis showed that hyperglycemia and hyperinsulinemia were not sufficient to compensate for the defect in glucose metabolism in obesity and diabetes. Conclusions Augmented insulin and glucose responses during an OGTT are not sufficient to overcome the underlying defects in glucose metabolism in obesity and diabetes. PMID:25511878

  17. Cancerous glucose metabolism in lung cancer-evidence from exhaled breath analysis.

    PubMed

    Feinberg, Tali; Alkoby-Meshulam, Layah; Herbig, Jens; Cancilla, John C; Torrecilla, Jose S; Gai Mor, Naomi; Bar, Jair; Ilouze, Maya; Haick, Hossam; Peled, Nir

    2016-06-01

    Cancer cells prefer hyperglycolysis versus oxidative phosphorylation, even in the presence of oxygen. This phenomenon is used through the FDG-PET scans, and may affect the exhaled volatile signature. This study investigates the volatile signature in lung cancer (LC) before and after an oral glucose tolerance test (OGTT) to determine if tumor cells' hyperglycolysis would affect the volatile signature. Blood glucose levels and exhaled breath samples were analyzed before the OGTT, and 90 min after, in both LC patients and controls. The volatile signature was measured by proton transfer reaction mass spectrometry (PTR-MS). Twenty-two LC patients (age 66.6  ±  12.7) with adenocarcinoma (n  =  14), squamous (n  =  6), small cell carcinoma (n  =  2), and twenty-one controls (age 54.4  ±  13.7; 10 non-smokers and 11 smokers) were included. All LC patients showed a hyperglycolytic state in their FDG-PET scans. Both baseline and post OGTT volatile signatures discriminate between the groups. The OGTT has a minimal effect in LC (a decrease in m/z 54 by 39%, p v  =  0.0499); whereas in the control group, five masses (m/z 64, 87,88, 142 and 161) changed by  -13%, -49%, -40% and  -29% and 46% respectively. To conclude, OGTT has a minimal effect on the VOC signature in LC patients, where a hyperglycolytic state already exists. In contrast, in the control group the OGTT has a profound effect in which induced hyperglycolysis significantly changed the VOC pattern. We hypothesized that a ceiling effect in cancerous patients is responsible for this discrepancy. PMID:27272440

  18. Setting Spacecraft Maximum Allowable Concentrations for 1 hour or 24 hour contingency exposures to airborne chemicals

    NASA Technical Reports Server (NTRS)

    Garcia, Hector D.; Limero, Thomas F.; James, John T.

    1992-01-01

    Since the early years of the manned space program, NASA has developed and used exposure limits called Spacecraft Maximum Allowable Concentrations (SMACs) to help protect astronauts from airborne toxicants. Most of these SMACS are based on an exposure duration of 7 days, since this is the duration of a 'typical' mission. A set of 'contingency SMACs' is also being developed for scenarios involving brief (1-hour or 24- hour) exposures to relatively high levels of airborne toxicants from event-related 'contingency' releases of contaminants. The emergency nature of contingency exposures dictates the use of different criteria for setting exposure limits. The NASA JSC Toxicology Group recently began a program to document the rationales used to set new SMACs and plans to review the older, 7-day SMACs. In cooperation with the National Research Council's Committee on Toxicology, a standard procedure has been developed for researching, setting, and documenting SMAC values.

  19. Effect of a 1-hour single bout of moderate-intensity exercise on fat oxidation kinetics.

    PubMed

    Chenevière, Xavier; Borrani, Fabio; Ebenegger, Vincent; Gojanovic, Boris; Malatesta, Davide

    2009-12-01

    The present study aimed to examine the effects of a prior 1-hour continuous exercise bout (CONT) at an intensity (Fat(max)) that elicits the maximal fat oxidation (MFO) on the fat oxidation kinetics during a subsequent submaximal incremental test (IncrC). Twenty moderately trained subjects (9 men and 11 women) performed a graded test on a treadmill (Incr), with 3-minute stages and 1-km.h(-1) increments. Fat oxidation was measured using indirect calorimetry and plotted as a function of exercise intensity. A mathematical model (SIN) including 3 independent variables (dilatation, symmetry, and translation) was used to characterize the shape of fat oxidation kinetics and to determine Fat(max) and MFO. On a second visit, the subjects performed CONT at Fat(max) followed by IncrC. After CONT performed at 57% +/- 3% (means +/- SE) maximal oxygen uptake (Vo(2max)), the respiratory exchange ratio during IncrC was lower at every stage compared with Incr (P < .05). Fat(max) (56.4% +/- 2.3% vs 51.5% +/- 2.4% Vo(2max), P = .013), MFO (0.50 +/- 0.03 vs 0.40 +/- 0.03 g.min(-1), P < .001), and fat oxidation rates from 35% to 70% Vo(2max) (P < .05) were significantly greater during IncrC compared with Incr. However, dilatation and translation were not significantly different (P > .05), whereas symmetry tended to be greater in IncrC (P = .096). This study showed that the prior 1-hour continuous moderate-intensity exercise bout increased Fat(max), MFO, and fat oxidation rates over a wide range of intensities during the postexercise incremental test. Moreover, the shape of the postexercise fat oxidation kinetics tended to have a rightward asymmetry. PMID:19632694

  20. Validation of 1-hour post-thyroidectomy parathyroid hormone level in predicting hypocalcemia

    PubMed Central

    2014-01-01

    Background Prior work by our group suggested that a single one hour post-thyroidectomy parathyroid hormone (1 hr PTH) level could accurately stratify patients into high and low risk groups for the development of hypocalcemia. This study looks to validate the safety and efficacy of a protocol based on a 1 hr PTH threshold of 12 pg/ml. Study design Retrospective analysis of consecutive cohort treated with standardized protocol. Methods One hundred and twenty five consecutive patients underwent total or completion thyroidectomy and their PTH level was drawn 1-hour post operatively. Based on our previous work, patients were stratified into either a low risk group (PTH < 12 pg/ml) or a high risk group (PTH ≥ 12 pg/ml). Patients in the high risk group were immediately started on prophylactic calcium carbonate (5–10 g/d) and calcitriol (0.5-1.0 mcg/d). The outcomes were then reviewed focusing mainly on how many low risk patients developed hypocalcemia (false negative rate), and how many high risk patients failed prophylactic therapy. Results Thirty one patients (25%) were stratified as high risk, and 94 (75%) as low risk. Five (16%) of the high risk patients became hypocalcemic despite prophylactic therapy. Two of the low risk group became hypocalcemic, (negative predictive value = 98%). None of the hypocalcemic patients had anything more than mild symptoms. Conclusions A single 1-hour post-thyroidectomy PTH level is a very useful way to stratify thyroidectomy patients into high and low risk groups for development of hypocalcemia. Early implementation of oral prophylactic calcium and vitamin D in the high risk patients is a very effective way to prevent serious hypocalcemia. Complex protocols requiring multiple calcium and PTH measurements are not required to guide post-thyroidectomy management. PMID:24476535

  1. Amino Acid and Biogenic Amine Profile Deviations in an Oral Glucose Tolerance Test: A Comparison between Healthy and Hyperlipidaemia Individuals Based on Targeted Metabolomics.

    PubMed

    Li, Qi; Gu, Wenbo; Ma, Xuan; Liu, Yuxin; Jiang, Lidan; Feng, Rennan; Liu, Liyan

    2016-01-01

    Hyperlipidemia (HLP) is characterized by a disturbance in lipid metabolism and is a primary risk factor for the development of insulin resistance (IR) and a well-established risk factor for cardiovascular disease and atherosclerosis. The aim of this work was to investigate the changes in postprandial amino acid and biogenic amine profiles provoked by an oral glucose tolerance test (OGTT) in HLP patients using targeted metabolomics. We used ultra-high-performance liquid chromatography-triple quadrupole mass spectrometry to analyze the serum amino acid and biogenic amine profiles of 35 control and 35 HLP subjects during an OGTT. The amino acid and biogenic amine profiles from 30 HLP subjects were detected as independent samples to validate the changes in the metabolites. There were differences in the amino acid and biogenic amine profiles between the HLP individuals and the healthy controls at baseline and after the OGTT. The per cent changes of 13 metabolites from fasting to the 2 h samples during the OGTT in the HLP patients were significantly different from those of the healthy controls. The lipid parameters were associated with the changes in valine, isoleucine, creatine, creatinine, dimethylglycine, asparagine, serine, and tyrosine (all p < 0.05) during the OGTT in the HLP group. The postprandial changes in isoleucine and γ-aminobutyric acid (GABA) during the OGTT were positively associated with the homeostasis model assessment of insulin resistance (HOMA-IR; all p < 0.05) in the HLP group. Elevated oxidative stress and disordered energy metabolism during OGTTs are important characteristics of metabolic perturbations in HLP. Our findings offer new insights into the complex physiological regulation of metabolism during the OGTT in HLP. PMID:27338465

  2. Amino Acid and Biogenic Amine Profile Deviations in an Oral Glucose Tolerance Test: A Comparison between Healthy and Hyperlipidaemia Individuals Based on Targeted Metabolomics

    PubMed Central

    Li, Qi; Gu, Wenbo; Ma, Xuan; Liu, Yuxin; Jiang, Lidan; Feng, Rennan; Liu, Liyan

    2016-01-01

    Hyperlipidemia (HLP) is characterized by a disturbance in lipid metabolism and is a primary risk factor for the development of insulin resistance (IR) and a well-established risk factor for cardiovascular disease and atherosclerosis. The aim of this work was to investigate the changes in postprandial amino acid and biogenic amine profiles provoked by an oral glucose tolerance test (OGTT) in HLP patients using targeted metabolomics. We used ultra-high-performance liquid chromatography-triple quadrupole mass spectrometry to analyze the serum amino acid and biogenic amine profiles of 35 control and 35 HLP subjects during an OGTT. The amino acid and biogenic amine profiles from 30 HLP subjects were detected as independent samples to validate the changes in the metabolites. There were differences in the amino acid and biogenic amine profiles between the HLP individuals and the healthy controls at baseline and after the OGTT. The per cent changes of 13 metabolites from fasting to the 2 h samples during the OGTT in the HLP patients were significantly different from those of the healthy controls. The lipid parameters were associated with the changes in valine, isoleucine, creatine, creatinine, dimethylglycine, asparagine, serine, and tyrosine (all p < 0.05) during the OGTT in the HLP group. The postprandial changes in isoleucine and γ-aminobutyric acid (GABA) during the OGTT were positively associated with the homeostasis model assessment of insulin resistance (HOMA-IR; all p < 0.05) in the HLP group. Elevated oxidative stress and disordered energy metabolism during OGTTs are important characteristics of metabolic perturbations in HLP. Our findings offer new insights into the complex physiological regulation of metabolism during the OGTT in HLP. PMID:27338465

  3. Risk Factors and Plasma Glucose Profile of Gestational Diabetes in Omani Women

    PubMed Central

    Chitme, Havagiray R; Al Shibli, Sumaiya Abdallah Said; Al-Shamiry, Raya Mahmood

    2016-01-01

    Objectives We sought to conduct a detailed study on the risk factors of gestational diabetes mellitus (GDM) in Omani women to determine the actual and applicable risk factors and glucose profile in this population. Methods We conducted a cross-sectional case-control study using pregnant women diagnosed with GDM. Pregnant women without GDM were used as a control group. We collected information related to age, family history, prior history of pregnancy complications, age of marriage, age of first pregnancy, fasting glucose level, and oral glucose tolerance test (OGTT) results from three hospitals in Oman through face-to-face interviews and hospital records. Results The median age of women with GDM was 33 years old (p < 0.050). A significant risk was noted in women with a history of diabetes (p < 0.001), and those with mothers’ with a history of GDM. A significant (p < 0.010) relationship with a likelihood ratio of 43.9 was observed between the incidence of GDM in women with five or six pregnancies, a history of > 3 deliveries, height < 155 cm, and pregnancy or marriage at age < 18 years (p < 0.010). The mean difference in random plasma glucose, one-hour OGTT, and two-hour OGTT was significantly higher in GDM cases compared to control. Conclusions Glucose profile, family history, anthropometric profile, and age of first pregnancy and marriage should be considered while screening for GDM and determining the care needs of Omani women with GDM. PMID:27602192

  4. Insulin and glucose responses during bed rest with isotonic and isometric exercise

    NASA Technical Reports Server (NTRS)

    Dolkas, C. B.; Greenleaf, J. E.

    1977-01-01

    The effects of daily intensive isotonic (68% maximum oxygen uptake) and isometric (21% maximum extension force) leg exercise on plasma insulin and glucose responses to an oral glucose tolerance test (OGTT) during 14-day bed-rest (BR) periods were investigated in seven young healthy men. The OGTT was given during ambulatory control and on day 10 of the no-exercise, isotonic, and isometric exercise BR periods during the 15-wk study. The subjects were placed on a controlled diet starting 10 days before each BR period. During BR, basal plasma glucose concentration remained unchanged with no exercise, but increased (P less 0.05) to 87-89 mg/100 ml with both exercise regimens on day 2, and then fell slightly below control levels on day 13. The fall in glucose content during BR was independent of the exercise regimen and was an adjustment for the loss of plasma volume. The intensity of the responses of insulin and glucose to the OGTT was inversely proportional to the total daily energy expenditure during BR. It was estimated that at least 1020 kcal/day must be provided by supplemental exercise to restore the hyperinsulinemia to control levels.

  5. β-Cell Function, Incretin Effect, and Incretin Hormones in Obese Youth Along the Span of Glucose Tolerance From Normal to Prediabetes to Type 2 Diabetes

    PubMed Central

    Michaliszyn, Sara F.; Mari, Andrea; Lee, SoJung; Bacha, Fida; Tfayli, Hala; Farchoukh, Lama; Ferrannini, Ele

    2014-01-01

    Using the hyperglycemic and euglycemic clamp, we demonstrated impaired β-cell function in obese youth with increasing dysglycemia. Herein we describe oral glucose tolerance test (OGTT)-modeled β-cell function and incretin effect in obese adolescents spanning the range of glucose tolerance. β-Cell function parameters were derived from established mathematical models yielding β-cell glucose sensitivity (βCGS), rate sensitivity, and insulin sensitivity in 255 obese adolescents (173 with normal glucose tolerance [NGT], 48 with impaired glucose tolerance [IGT], and 34 with type 2 diabetes [T2D]). The incretin effect was calculated as the ratio of the OGTT-βCGS to the 2-h hyperglycemic clamp-βCGS. Incretin and glucagon concentrations were measured during the OGTT. Compared with NGT, βCGS was 30 and 65% lower in youth with IGT and T2D, respectively; rate sensitivity was 40% lower in T2D. Youth with IGT or T2D had 32 and 38% reduced incretin effect compared with NGT in the face of similar changes in GLP-1 and glucose-dependent insulinotropic polypeptide (GIP) in response to oral glucose. We conclude that glucose sensitivity deteriorates progressively in obese youth across the spectrum of glucose tolerance in association with impairment in incretin effect without reduction in GLP-1 or GIP, similar to that seen in adult dysglycemia. PMID:24947360

  6. Hyperbaric Oxygen Therapy Improves Glucose Homeostasis in Type 2 Diabetes Patients: A Likely Involvement of the Carotid Bodies.

    PubMed

    Vera-Cruz, P; Guerreiro, F; Ribeiro, M J; Guarino, M P; Conde, S V

    2015-01-01

    The carotid bodies (CBs) are peripheral chemoreceptors that respond to hypoxia increasing minute ventilation and activating the sympathetic nervous system. Besides its role in ventilation we recently described that CB regulate peripheral insulin sensitivity. Knowing that the CB is functionally blocked by hyperoxia and that hyperbaric oxygen therapy (HBOT) improves fasting blood glucose in diabetes patients, we have investigated the effect of HBOT on glucose tolerance in type 2 diabetes patients. Volunteers with indication for HBOT were recruited at the Subaquatic and Hyperbaric Medicine Center of Portuguese Navy and divided into two groups: type 2 diabetes patients and controls. Groups were submitted to 20 sessions of HBOT. OGTT were done before the first and after the last HBOT session. Sixteen diabetic patients and 16 control individual were included. Fasting glycemia was143.5 ± 12.62 mg/dl in diabetic patients and 92.06 ± 2.99 mg/dl in controls. In diabetic patients glycemia post-OGTT was 280.25 ± 22.29 mg/dl before the first HBOT session. After 20 sessions, fasting and 2 h post-OGTT glycemia decreased significantly. In control group HBOT did not modify fasting glycemia and post-OGTT glycemia. Our results showed that HBOT ameliorates glucose tolerance in diabetic patients and suggest that HBOT could be used as a therapeutic intervention for type 2 diabetes. PMID:26303484

  7. Application of dynamic metabolomics to examine in vivo skeletal muscle glucose metabolism in the chronically high-fat fed mouse

    SciTech Connect

    Kowalski, Greg M.; De Souza, David P.; Burch, Micah L.; Hamley, Steven; Kloehn, Joachim; Selathurai, Ahrathy; Tull, Dedreia; O'Callaghan, Sean; McConville, Malcolm J.; Bruce, Clinton R.

    2015-06-19

    Rationale: Defects in muscle glucose metabolism are linked to type 2 diabetes. Mechanistic studies examining these defects rely on the use of high fat-fed rodent models and typically involve the determination of muscle glucose uptake under insulin-stimulated conditions. While insightful, they do not necessarily reflect the physiology of the postprandial state. In addition, most studies do not examine aspects of glucose metabolism beyond the uptake process. Here we present an approach to study rodent muscle glucose and intermediary metabolism under the dynamic and physiologically relevant setting of the oral glucose tolerance test (OGTT). Methods and results: In vivo muscle glucose and intermediary metabolism was investigated following oral administration of [U-{sup 13}C] glucose. Quadriceps muscles were collected 15 and 60 min after glucose administration and metabolite flux profiling was determined by measuring {sup 13}C mass isotopomers in glycolytic and tricarboxylic acid (TCA) cycle intermediates via gas chromatography–mass spectrometry. While no dietary effects were noted in the glycolytic pathway, muscle from mice fed a high fat diet (HFD) exhibited a reduction in labelling in TCA intermediates. Interestingly, this appeared to be independent of alterations in flux through pyruvate dehydrogenase. In addition, our findings suggest that TCA cycle anaplerosis is negligible in muscle during an OGTT. Conclusions: Under the dynamic physiologically relevant conditions of the OGTT, skeletal muscle from HFD fed mice exhibits alterations in glucose metabolism at the level of the TCA cycle. - Highlights: • Dynamic metabolomics was used to investigate muscle glucose metabolism in vivo. • Mitochondrial TCA cycle metabolism is altered in muscle of HFD mice. • This defect was not pyruvate dehydrogenase mediated, as has been previously thought. • Mitochondrial TCA cycle anaplerosis in muscle is virtually absent during the OGTT.

  8. Internal Oblique and Transversus Abdominis Muscle Fatigue Induced by Slumped Sitting Posture after 1 Hour of Sitting in Office Workers

    PubMed Central

    Waongenngarm, Pooriput; Rajaratnam, Bala S.; Janwantanakul, Prawit

    2015-01-01

    Background Prolonged sitting leads to low back discomfort and lumbopelvic muscle fatigue. This study examined the characteristics of body perceived discomfort and trunk muscle fatigue during 1 hour of sitting in three postures in office workers. Methods Thirty workers sat for 1 hour in one of three sitting postures (i.e., upright, slumped, and forward leaning postures). Body discomfort was assessed using the Body Perceived Discomfort scale at the beginning and after 1 hour of sitting. Electromyographic (EMG) signals were recorded from superficial lumbar multifidus, iliocostalis lumborum pars thoracis, internal oblique (IO)/transversus abdominis (TrA), and rectus abdominis muscles during 1 hour of sitting. The median frequency (MDF) of the EMG power spectrum was calculated. Results Regardless of the sitting posture, the Body Perceived Discomfort scores in the neck, shoulder, upper back, low back, and buttock significantly increased after 1 hour of sitting compared with baseline values (t(9) = −11.97 to −2.69, p < 0.05). The MDF value of the EMG signal of rectus abdominis, iliocostalis lumborum pars thoracis, and multifidus muscles was unchanged over time in all three sitting postures. Only the right and left IO/TrA in the slumped sitting posture was significantly associated with decreased MDF over time (p = 0.019 to 0.041). Conclusion Prolonged sitting led to increased body discomfort in the neck, shoulder, upper back, low back, and buttock. No sign of trunk muscle fatigue was detected over 1 hour of sitting in the upright and forward leaning postures. Prolonged slumped sitting may relate to IO/TrA muscle fatigue, which may compromise the stability of the spine, making it susceptible to injury. PMID:27014491

  9. 40 CFR 50.9 - National 1-hour primary and secondary ambient air quality standards for ozone.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...-hour standards are codified in 40 CFR part 81. (c) EPA's authority under paragraph (b) of this section... ambient air quality standards for ozone. 50.9 Section 50.9 Protection of Environment ENVIRONMENTAL....9 National 1-hour primary and secondary ambient air quality standards for ozone. (a) The level...

  10. 76 FR 28195 - Approval and Promulgation of Air Quality Implementation Plans; New Mexico; Sunland Park 1-Hour...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-16

    ... attainment of the 8-hour ozone National Ambient Air Quality Standard (NAAQS) through the year 2014. The... AGENCY 40 CFR Part 52 Approval and Promulgation of Air Quality Implementation Plans; New Mexico; Sunland Park 1-Hour Ozone Maintenance Plan AGENCY: Environmental Protection Agency (EPA). ACTION: Proposed...

  11. Exhaled breath condensate pH decreases following oral glucose tolerance test.

    PubMed

    Bikov, Andras; Pako, Judit; Montvai, David; Kovacs, Dorottya; Koller, Zsofia; Losonczy, Gyorgy; Horvath, Ildiko

    2015-12-01

    Exhaled breath condensate (EBC) pH is a widely measured non-invasive marker of airway acidity. However, some methodological aspects have not been thoroughly investigated. The aim of the study was to determine the effect of oral glucose tolerance test (OGTT) on EBC pH in attempt to better standardize its measurement. Seventeen healthy subjects (24  ±  2 years, 6 men, 11 women) participated in the study. EBC collection and capillary blood glucose measurements were performed before as well as 0, 30, 60 and 120 min after a standardized OGTT test. The rate of respiratory droplet dilution and pH were evaluated in EBC. Blood glucose significantly increased at 30 min and maintained elevation after 60 and 120 min following OGTT. Compared to baseline (7.99  ±  0.25) EBC pH significantly decreased immediately after OGTT (7.41  ±  0.47); this drop sustained over 30 (7.44  ±  0.72) and 60 min (7.62  ±  0.44) without a significant difference at 120 min (7.78  ±  0.26). No change was observed in the rate of respiratory droplet dilution. There was no relationship between blood glucose and EBC pH values. Sugar intake may significantly decrease EBC pH. This effect needs to be considered when performing EBC pH studies. Further experiments are also warranted to investigate the effect of diet on other exhaled biomarkers. PMID:26669903

  12. Tacrolimus Induces Insulin Resistance and Increases the Glucose Absorption in the Jejunum: A Potential Mechanism of the Diabetogenic Effects

    PubMed Central

    Zhang, Yaohui; Chen, Hao; He, Ningning; Chen, Hui; Song, Penghong; Wang, Yan; Yan, Sheng; Zheng, Shusen

    2015-01-01

    Background The use of the immunosuppressive drug tacrolimus (TAC) is related to new onset diabetes after transplantation. Herein, we examined the effect of intraperitoneal administered TAC on intestinal glucose absorption in mice. Methods Animals received low, medium, or high dose TAC (0.5, 1, or 5 mg/kg/d, respectively), or 0.9% saline solution (control) for 14 days. Oral glucose tolerance test (OGTT), insulin concentration test, and serum TAC concentration measurements was performed after 14 days of TAC exposure. Plasma insulin was assessed and electrogenic glucose absorption were measured by the sodium-dependent increase of the short-circuit current. Expression levels of the glucose transporters sodium glucose co-transporter (SGLT) 1, glucose transporter (GLUT) 2, and GLUT5 were also determined. Results Oral glucose absorption assessed by OGTT was significantly enhanced in the low, medium, and high groups. Serum insulin was elevated in the medium and high group compared with the control. Moreover, glucose-induced Isc was significantly higher in TAC administrated groups, which indicates that SGLT1 activity increased. Transcription levels and protein abundance of SGLT1 in the experimental groups also increased compared with the control. Conclusions TAC induced insulin resistance and strengthened intestinal glucose absorption by increasing the activity and expression of the glucose transporter, SGLT1. PMID:26599323

  13. Plasma Lactate Levels Increase during Hyperinsulinemic Euglycemic Clamp and Oral Glucose Tolerance Test.

    PubMed

    Berhane, Feven; Fite, Alemu; Daboul, Nour; Al-Janabi, Wissam; Msallaty, Zaher; Caruso, Michael; Lewis, Monique K; Yi, Zhengping; Diamond, Michael P; Abou-Samra, Abdul-Badi; Seyoum, Berhane

    2015-01-01

    Insulin resistance, which plays a central role in the pathogenesis of type 2 diabetes (T2D), is an early indicator that heralds the occurrence of T2D. It is imperative to understand the metabolic changes that occur at the cellular level in the early stages of insulin resistance. The objective of this study was to determine the pattern of circulating lactate levels during oral glucose tolerance test (OGTT) and hyperinsulinemic euglycemic clamp (HIEC) study in normal nondiabetic subjects. Lactate and glycerol were determined every 30 minutes during OGTT and HIEC on 22 participants. Lactate progressively increased throughout the HIEC study period (P < 0.001). Participants with BMI < 30 had significantly higher mean M-values compared to those with BMI ≥ 30 at baseline (P < 0.05). This trend also continued throughout the OGTT. In addition, those with impaired glucose tolerance test (IGT) had significantly higher mean lactate levels compared to those with normal glucose tolerance (P < 0.001). In conclusion, we found that lactate increased during HIEC study, which is a state of hyperinsulinemia similar to the metabolic milieu seen during the early stages in the development of T2D. PMID:25961050

  14. The effect of endurance training and subsequent physical inactivity on glycaemic control after oral glucose load and physical exercise in healthy men

    NASA Astrophysics Data System (ADS)

    Radikova, Zofia; Ksinantova, Lucia; Kaciuba-Uscilko, Hanna; Nazar, Krystyna; Vigas, Milan; Koska, Juraj

    2007-02-01

    Physical inactivity during space flight has a profound effect on glucose metabolism. The aim of this study was to test whether endurance training (ET) may improve a negative effect of subsequent -6∘ head-down bed rest (HDBR) on glucose metabolism. Fourteen healthy males completed the study consisting of 6 weeks lasting ET followed by 6 days HDBR. Treadmill exercise at 80% of pre-training VO2max and 75 g oral glucose tolerance test (OGTT) were performed before and after ET as well as after HDBR. ET increased VO2max by 11%. ET significantly lowered while HDBR had no effect on fasting and OGTT plasma glucose levels. ET had no effect while HDBR was followed by an augmentation of insulin and C-peptide response to OGTT. Insulin sensitivity tended to increase after ET and to decrease during HDBR, however, mostly without statistical significance. Plasma glucose, insulin and C-peptide response to exercise were elevated after HDBR only. Our study shows that antecedent physical training could ameliorate a negative effect of simulated microgravity on insulin-mediated glucose metabolism.

  15. Noninvasive blood glucose monitoring with laser diode

    NASA Astrophysics Data System (ADS)

    Zhang, Xiqin; Chen, Jianhong; Ooi, Ean Tat; Yeo, Joon Hock

    2006-02-01

    The non-invasive measurement of blood sugar level was studied by use of near infrared laser diodes. The in vitro and in vivo experiments were carried out using six laser diodes having wavelengths range from 1550 nm to 1750nm. Several volunteers were tested for OGTT (Oral Glucose Tolerance Test) experiment. We took blood from a fingertip and measured its concentration with a glucose meter while taking signal voltage from laser diodes system. The data of signal voltage were processed to do calibration and prediction; in this paper PLS (Partial Least Square) method was used to do modeling. For in vitro experiment, good linear relationship between predicted glucose concentration and real glucose concentration was obtained. For in vivo experiments, we got the blood sugar level distributions in Clarke error grid that is a reference for doctors to do diagnosis and treatment. In the Clarke error grid, 75% of all data was in area A and 25 % was in area B. From the in vitro and in vivo results we know that multiple laser diodes are suitable for non-invasive blood glucose monitoring.

  16. Development and assessment of the disposition index based on the oral glucose tolerance test in subjects with different glycaemic status.

    PubMed

    Santos, J L; Yévenes, I; Cataldo, L R; Morales, M; Galgani, J; Arancibia, C; Vega, J; Olmos, P; Flores, M; Valderas, J P; Pollak, F

    2016-06-01

    Insulin secretion and insulin sensitivity indexes are related by hyperbolic functions, allowing the calculation of the disposition index (DI) as the product of the acute insulin response (AIR) and the insulin sensitivity index (Si) from intravenous glucose tolerance test (IVGTT). Our objective was to develop an oral-DI based on the oral glucose tolerance test (OGTT) and to assess its association with glucose tolerance status. This research is structured in three studies. Study 1: OGTT were performed in 833 non-diabetic Chilean women (18-60 years) without family history of diabetes mellitus. Study 2: an independent group of n = 57 non-diabetic (18-46 years) without family history of diabetes mellitus carried out an OGTT and an abbreviated IVGTT. Study 3: a sample of 1674 Chilean adults (18-60 years) with different glycaemic status performed an OGTT. An adequate statistical fit for a rectangular hyperbola was found between the area under the curve of insulin-to-glucose ratio (AUCI/G-R) and the Matsuda ISI-COMP index (study 1). The oral-DI derived as AUCI/G-R × ISI-COMP was previously termed insulin-secretion-sensitivity index-2 (ISSI-2). ISSI-2 significantly correlated with DI from IVGTT (rho = 0.34; p = 0.009) (study 2). ISSI-2 shows important differences across groups of subjects with different glycaemic status (study 3). We have confirmed that ISSI-2 replicates the mathematical properties of DI, showing significant correlations with DI from the abbreviated MM-IVGTT. These results indicate that ISSI-2 constitutes a surrogate measure of insulin secretion relative to insulin sensitivity and emphasizes the pivotal role of impaired insulin secretion in the development of glucose homeostasis dysregulation. PMID:26660757

  17. Blood levels of branched-chain alpha-keto acids in uremia: effect of an oral glucose tolerance test.

    PubMed

    Schauder, P; Matthaei, D; Henning, H V; Scheler, F; Langenbeck, U

    1981-08-01

    The effect of an oral glucose tolerance test (oGTT) on serum levels of branched-chain keto acids (BCKA), i.e. alpha-keto-isocaproic acid (KICA), alpha-keto-isovaleric acid (KIVA) and alpha-keto-beta methyl-n-valeric acid (KMVA) as well as on serum insulin, C-peptide and blood glucose levels was determined in uremic patients and in healthy control subjects. In controls, blood levels of KICA, KMVA and KIVA declined significantly following oral administration of 100 glucose. In uremic patients no decline of KICA was observed. The fall of KMVA was diminished, while suppression of KIVA blood levels in response to the oGGT remained unimpaired. Although serum insulin and C-peptide levels in uremic patients were not significantly different from the controls before and throughout the oGTT, six out of eight displayed abnormal glucose tolerance. It is suggested that the response of blood BCKA levels to an oGTT is altered in uremia, an abnormality restricted primarily to KICA and possibly explained by insulin antagonism and/or by insufficient insulin secretion. PMID:7021997

  18. The fetal glucose steal: an underappreciated phenomenon in diabetic pregnancy.

    PubMed

    Desoye, Gernot; Nolan, Christopher J

    2016-06-01

    Adverse neonatal outcomes continue to be high for mothers with type 1 and type 2 diabetes, and are far from eliminated in mothers with gestational diabetes mellitus. This is often despite seemingly satisfactory glycaemic control in the latter half of pregnancy. Here we argue that this could be a consequence of the early establishment of fetal hyperinsulinaemia, a driver that exaggerates the fetal glucose steal. Essentially, fetal hyperinsulinaemia, through its effect on lowering fetal glycaemia, will increase the glucose concentration gradient across the placenta and consequently the glucose flux to the fetus. While the steepness of this gradient and glucose flux will be greatest at times when maternal hyperglycaemia and fetal hyperinsulinaemia coexist, fetal hyperinsulinaemia will favour a persistently high glucose flux even at times when maternal blood glucose is normal. The obvious implication is that glycaemic control needs to be optimised very early in pregnancy to prevent the establishment of fetal hyperinsulinaemia, further supporting the need for pre-pregnancy planning and early establishment of maternal glycaemic control. An exaggerated glucose steal by a hyperinsulinaemic fetus could also attenuate maternal glucose levels during an OGTT, providing an explanation for why some mothers with fetuses with all the characteristics of diabetic fetopathy have 'normal' glucose tolerance. PMID:26995651

  19. The role of apolipoprotein E and glucose intolerance in gallstone disease in middle aged subjects

    PubMed Central

    Niemi, M; Kervinen, K; Rantala, A; Kauma, H; Paivansalo, M; Savolainen, M; Lilja, M; Kesaniemi, Y

    1999-01-01

    BACKGROUND—The polymorphism of apolipoprotein E has been suggested to be associated with the cholesterol content of gallstones, the crystallisation rate of gall bladder bile, and the prevalence of gallstone disease (GSD). 
AIMS—To investigate whether apolipoprotein E polymorphism modulates the susceptibility to GSD at the population level and to study the possible associations between impaired glucose tolerance, diabetes, and GSD. 
METHODS—Apolipoprotein E phenotypes were determined in a middle aged cohort of 261 randomly selected hypertensive men, 259 control men, 257 hypertensive women, and 267 control women. All subjects without a documented history of diabetes were submitted to a two hour oral glucose tolerance test (OGTT). GSD was verified by ultrasonography. 
RESULTS—In women with apolipoprotein E2 (phenotypes E2/2, 2/3, and 2/4) compared with women without E2 (E3/3, 4/3, and 4/4), the odds ratio for GSD was 0.28 (95% confidence interval 0.08-0.92). There was no protective effect in men. The relative risk for GSD was 1.2 (0.8-1.7) for hypertensive women and 1.8(1.0-2.7) for hypertensive men. In a stepwise multiple logistic regression model, E2 protected against GSD in women, whereas two hour blood glucose in the OGTT, serum insulin, and plasma triglycerides were risk factors. Elevated blood glucose during the OGTT was also a significant risk factor for GSD in men. 
CONCLUSIONS—The data suggest that apolipoprotein E2 is a genetic factor providing protection against GSD in women. In contrast, impaired glucose tolerance and frank diabetes are associated with the risk of GSD. 

 Keywords: apolipoprotein E; gallstone disease; diabetes; impaired glucose tolerance; cholesterol PMID:10075965

  20. Metabolic Networks and Metabolites Underlie Associations Between Maternal Glucose During Pregnancy and Newborn Size at Birth.

    PubMed

    Scholtens, Denise M; Bain, James R; Reisetter, Anna C; Muehlbauer, Michael J; Nodzenski, Michael; Stevens, Robert D; Ilkayeva, Olga; Lowe, Lynn P; Metzger, Boyd E; Newgard, Christopher B; Lowe, William L

    2016-07-01

    Maternal metabolites and metabolic networks underlying associations between maternal glucose during pregnancy and newborn birth weight and adiposity demand fuller characterization. We performed targeted and nontargeted gas chromatography/mass spectrometry metabolomics on maternal serum collected at fasting and 1 h following glucose beverage consumption during an oral glucose tolerance test (OGTT) for 400 northern European mothers at ∼28 weeks' gestation in the Hyperglycemia and Adverse Pregnancy Outcome Study. Amino acids, fatty acids, acylcarnitines, and products of lipid metabolism decreased and triglycerides increased during the OGTT. Analyses of individual metabolites indicated limited maternal glucose associations at fasting, but broader associations, including amino acids, fatty acids, carbohydrates, and lipids, were found at 1 h. Network analyses modeling metabolite correlations provided context for individual metabolite associations and elucidated collective associations of multiple classes of metabolic fuels with newborn size and adiposity, including acylcarnitines, fatty acids, carbohydrates, and organic acids. Random forest analyses indicated an improved ability to predict newborn size outcomes by using maternal metabolomics data beyond traditional risk factors, including maternal glucose. Broad-scale association of fuel metabolites with maternal glucose is evident during pregnancy, with unique maternal metabolites potentially contributing specifically to newborn birth weight and adiposity. PMID:27207545

  1. No Islet Cell Hyperfunction, but Altered Gut-Islet Regulation and Postprandial Hypoglycemia in Glucose-Tolerant Patients 3 Years After Gastric Bypass Surgery.

    PubMed

    Dirksen, Carsten; Eiken, Aleksander; Bojsen-Møller, Kirstine N; Svane, Maria S; Martinussen, Christoffer; Jørgensen, Nils B; Holst, Jens J; Madsbad, Sten

    2016-09-01

    Postprandial hyperinsulinemia characterizes Roux-en-Y gastric bypass (RYGB) and sometimes leads to reactive hypoglycemia. We prospectively evaluated changes in beta cell function in seven RYGB-operated patients with a median follow-up of 2.9 years with hyperglycemic clamps and oral glucose tolerance tests (OGTTs). Three years after RYGB, weight loss was 26 % and insulin sensitivity had improved. Insulin secretion during clamp experiments was largely unchanged compared to before surgery. In contrast, insulin secretion in response to the OGTTs doubled when evaluated by the disposition index and 2-h plasma glucose declined to a mean of 3.3 ± 0.3 mmol/l postoperatively. Our findings indicate that intrinsic beta cell function remains unchanged in glucose-tolerant patients even years after RYGB, while altered gut-islet regulation drive risk of postprandial hyperinsulinemic hypoglycemia. PMID:27138601

  2. Investigation of the Blood Glucose Lowering Potential of the Jamaican Momordica charantia (Cerasee) Fruit in Sprague-Dawley Rats

    PubMed Central

    Burnett, A; McKoy, M-L; Singh, P

    2015-01-01

    ABSTRACT The Momordica charantia (MC) fruit has been documented to possess antidiabetic properties. However, these studies were not without controversy surrounding the blood glucose-lowering ability and the mechanism of action in diabetes therapy. In an effort to evaluate such claims in the Jamaican MC species known as cerasee, aqueous extracts of the unripe fruit were studied in normal and diabetic rats. Normal male Sprague-Dawley rats were divided into groups (n = 6) orally administered distilled water, 10% dimethyl sulfoxide (DMSO) solution, the aqueous extract (400 mg/kg body weight) and glibenclamide (15 mg/kg body weight), respectively prior to assessment of fasting blood glucose (FBG) concentration. The oral glucose tolerance test (OGTT) was conducted in normoglycaemic rats orally administered distilled water, 10% DMSO solution, glibenclamide (15 mg/kg body weight) or aqueous extracts of the fruit (200 and 400 mg/kg body weight). Blood glucose concentration was also monitored in streptozotocin-induced diabetic rats administered the aqueous extract (250 mg/kg body weight) or water vehicle after an overnight fast. The aqueous extracts showed no hypoglycaemic or antidiabetic activity. However, the administration of the aqueous extracts (200 and 400 mg/kg body weight) resulted in significant improvement in glucose tolerance of glucose-primed normoglycaemic rats during the OGTT. These data suggest that the glucose-lowering mechanism of the Jamaican MC fruit species likely involves altered glucose absorption across the gastrointestinal tract. PMID:26624580

  3. Investigation of the Blood Glucose Lowering Potential of the Jamaican Momordica charantia (Cerasee) Fruit in Sprague-Dawley Rats.

    PubMed

    Burnett, A; McKoy, M L; Singh, P

    2015-09-01

    The Momordica charantia (MC) fruit has been documented to possess antidiabetic properties. However, these studies were not without controversy surrounding the blood glucose-lowering ability and the mechanism of action in diabetes therapy. In an effort to evaluate such claims in the Jamaican MC species known as cerasee, aqueous extracts of the unripe fruit were studied in normal and diabetic rats. Normal male Sprague-Dawley rats were divided into groups (n = 6) orally administered distilled water, 10% dimethyl sulfoxide (DMSO) solution, the aqueous extract (400 mg/kg body weight) and glibenclamide (15 mg/kg body weight), respectively prior to assessment of fasting blood glucose (FBG) concentration. The oral glucose tolerance test (OGTT) was conducted in normoglycaemic rats orally administered distilled water, 10% DMSO solution, glibenclamide (15 mg/kg body weight) or aqueous extracts of the fruit (200 and 400 mg/kg body weight). Blood glucose concentration was also monitored in streptozotocin-induced diabetic rats administered the aqueous extract (250 mg/kg body weight) or water vehicle after an overnight fast. The aqueous extracts showed no hypoglycaemic or antidiabetic activity. However, the administration of the aqueous extracts (200 and 400 mg/kg body weight) resulted in significant improvement in glucose tolerance of glucose-primed normoglycaemic rats during the OGTT. These data suggest that the glucose-lowering mechanism of the Jamaican MC fruit species likely involves altered glucose absorption across the gastrointestinal tract. PMID:26624580

  4. [Amelioration of glucose tolerance and correction of reactive hypoglycemias induced by intravenous calcium infusion cannot be explained by modifications in blood glucagon levels].

    PubMed

    Vexiau, P; Cathelineau, G; Luyckx, A; Lefebvre, P

    1986-08-01

    Glucagon is not involved in intravenous calcium-induced improvement in glucose tolerance nor in correction of reactive hypoglycemia. Recent investigations have shown that intravenous (IV) calcium infusion improved blood glucose values in patients with moderately impaired glucose tolerance, and suppressed hypoglycemia in patients with isolated reactive hypoglycemia. The aim of this study was to investigate the possibility that these changes were secondary to calcium induced alterations in glucagon (IRG) secretion. Four groups of subjects were studied: group 1: normal controls (n = 7); group 2: patients with isolated hypoglycemia (n = 9); group 3: patients with impaired glucose tolerance without reactive hypoglycemia (n = 9) and group 4: patients with impaired glucose tolerance and reactive hypoglycemia (n = 10). All patients were submitted in randomized order to two 5 hour oral glucose tolerance tests (OGTT, 75 g glucose), during a simultaneous infusion, either of saline or of calcium (calcium gluconate 36.3 mEq/5 h.), starting 30 minutes before the OGTT. In none of the groups did calcium infusion influence basal plasma IRG. In group 1 and 3, oral glucose significantly suppressed IRG, and during IV calcium infusion this suppression disappeared. In group 2, glucose ingestion resulted in a paradoxical increase in IRG both during saline and during calcium infusion. In group 4, oral glucose induced a significant drop in plasma IRG and a rebound rise during hypoglycemia, results which were unaffected by IV calcium infusion. These data suggest that glucagon is not involved in the alterations of blood glucose profiles during OGTT observed during intravenous calcium infusion. PMID:3770273

  5. Glucose tolerance status is a better predictor of diabetes and cardiovascular outcomes than metabolic syndrome: a prospective cohort study

    PubMed Central

    2012-01-01

    Backround To evaluate the importance of oral glucose tolerance test (OGTT) in predicting diabetes and cardiovascular disease in patients with and without Metabolic Syndrome from a population treated in a primary care unit. Research design and methods A prospective cohort study was conducted with subjects regularly attending the primary care unit of Hospital de Clínicas de Porto Alegre. Participants underwent a 75 g OGTT. Metabolic syndrome definition was based on the criteria of IDF/AHA/NHLBI-2010. Results Participants mean age was 61 ± 12 years (males: 38%; whites: 67%). Of the 148 subjects included, 127 (86%) were followed for 36 ± 14 months, 21 (14%) were lost. Subjects were classified into four groups based on baseline OGTT: 29% normal (n = 43), 28% impaired fasting glucose (IFG; n = 42), 26% impaired glucose tolerance (IGT; n = 38), and 17% diabetes (n = 25). Metabolic syndrome prevalence was lower in normal group (28%), intermediate in IFG (62%) and IGT (65%) groups, and higher among subjects with diabetes (92%; P <0.001). Incidence of diabetes increased along with the stages of glucose metabolism disturbance (normal: 0%, IFG: 16%, IGT: 28%; P = 0.004). No patient with normal OGTT developed diabetes, regardless metabolic syndrome presence. Diabetes at baseline was the major determinant of cardiovascular disease occurrence (normal: 0%, IFG: 4%, IGT: 0%, diabetes: 24%; P = 0.001). In Cox-regression analysis, only the 2 h OGTT results were associated with diabetes (OR = 1.03; 95%CI 1.01–1.06; P <0.001) and cardiovascular disease development (OR = 1.013; 95%CI 1.002–1.025; P = 0.024). Conclusions In this sample of subjects undergoing diabetes screening, the OGTT predicted diabetes and cardiovascular disease more effectively than the metabolic syndrome status. PMID:22682107

  6. Glucose Intolerance after a Recent History of Gestational Diabetes Based on the 2013 WHO Criteria

    PubMed Central

    Benhalima, Katrien; Jegers, Katleen; Devlieger, Roland; Verhaeghe, Johan; Mathieu, Chantal

    2016-01-01

    Aims Uncertainty exists on the prevalence of glucose intolerance in women with a recent diagnosis of gestational diabetes (GDM) based on a two-step screening strategy and the 2013 World Health Organization (WHO) criteria. Our aim was to evaluate the uptake of postpartum screening, the prevalence and the risk factors for glucose intolerance in women with a recent history of GDM. Methods Retrospective analysis of the medical records of women with a recent history of GDM diagnosed in a universal two-step screening strategy with the 2013 WHO criteria. All women with a history of GDM are advised to undergo a 75g oral glucose tolerance test (OGTT) around 12 weeks postpartum. Indices of insulin sensitivity (the Matsuda index and the reciprocal of the homeostasis model assessment of insulin resistance, 1/HOMA-IR) and an index of beta-cell function, the Insulin Secretion-Sensitivity Index-2 (ISSI-2) were calculated based on the OGTT postpartum. Multivariable logistic regression was used to adjust for confounders such as age, BMI, ethnicity and breastfeeding. Results Of the 191 women with GDM, 29.3% (56) did not attend the scheduled postpartum OGTT. These women had a higher BMI (28.6 ±6.8 vs. 26.2 ± 5.6, p = 0.015), were more often from an ethnic minority (EM) background (41.1% vs. 25.2%, p = 0.029) and smoked more often during pregnancy (14.3% vs. 2.2%, p = 0.001) than women who attended the OGTT postpartum. Of all women (135) who received an OGTT postpartum, 42.2% (57) had prediabetes (11.9% impaired fasting glucose, 24.4% impaired glucose tolerance and 5.9% both impaired fasting and impaired glucose tolerance) and 1.5% (2) had overt diabetes. Compared to women with a normal OGTT postpartum, women with glucose intolerance were older (32.5±4.3 vs. 30.8±4.8 years, p = 0.049), were more often obese (34.5% vs. 17.3%, p = 0.023), were more often from an EM background (33.9% vs. 18.4%, p = 0.040), less often breastfed (69.5% vs. 84.2%, p = 0.041) and had more often an

  7. β-3AR W64R Polymorphism and 30-Minute Post-Challenge Plasma Glucose Levels in Obese Children

    PubMed Central

    Verdi, Hasibe; Tulgar Kınık, Sibel; Yılmaz Yalçın, Yaprak; Muratoğlu Şahin, Nursel; Yazıcı, Ayşe Canan; Ataç, F. Belgin

    2015-01-01

    Objective: In this study, we aimed to investigate the association of W64R polymorphism of the β3-adrenergic receptor gene (β-3AR) with childhood obesity and related pathologies. Methods: β-3AR gene W64R genotyping was carried out in 251 children aged 6-18 years. Of these subjects, 130 were obese (62 boys) and 121 were normal-weight (53 boys). In the obese group, fasting lipids, glucose and insulin levels were measured. Oral glucose tolerance test (OGTT) was performed in 75 of the obese patients. Results: The frequency of W64R genotype was similar in obese and non-obese children. In obese children, relative body mass index, waist-to-hip ratio, serum lipid, glucose and insulin levels, as well as homeostasis model assessment of insulin resistance (HOMA-IR) scores were not different between Arg allele carriers (W64R and R64R) and noncarriers (W64W). In 75 obese children, OGTT results showed that Arg allele carriers had significantly higher 30-minute glucose levels (p=0.027). Conclusion: W64R polymorphism of the β-3AR gene is not associated with obesity and waist-to-hip ratio in Turkish children. Although there were no relationships between the genotypes and lipid, glucose/insulin levels or HOMA-IR, the presence of W64R variant seemed to have an unfavorable influence on early glucose excursion after glucose loading. PMID:25800470

  8. 40 CFR 60.2943 - How do I convert my 1-hour arithmetic averages into the appropriate averaging times and units?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false How do I convert my 1-hour arithmetic... SOURCES Operator Training and Qualification Monitoring § 60.2943 How do I convert my 1-hour arithmetic... emissions at 7 percent oxygen. (b) Use Equation 2 in § 60.2975 to calculate the 12-hour rolling averages...

  9. 40 CFR 60.3042 - How do I convert my 1-hour arithmetic averages into the appropriate averaging times and units?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false How do I convert my 1-hour arithmetic... Construction On or Before December 9, 2004 Model Rule-Monitoring § 60.3042 How do I convert my 1-hour... calculate emissions at 7 percent oxygen. (b) Use Equation 2 in § 60.3076 to calculate the 12-hour...

  10. Decreased insulin secretion and glucose clearance in exocrine pancreas-insufficient pigs.

    PubMed

    Lozinska, Liudmyla; Weström, Björn; Prykhodko, Olena; Lindqvist, Andreas; Wierup, Nils; Ahrén, Bo; Szwiec, Katarzyna; Pierzynowski, Stefan G

    2016-01-01

    The effect of exocrine pancreatic function on the glucose-mediated insulin response and glucose utilization were studied in an exocrine pancreas-insufficient (EPI) pig model. Five 10-week-old EPI pigs after pancreatic duct ligation and 6 age-matched, non-operated control pigs were used in the study. Blood glucose, plasma insulin and C-peptide concentrations were monitored during meal (MGTT), oral (OGTT) and intravenous (IVGTT) glucose tolerance tests. Upon post-mortem examination, the pancreatic remnants of the EPI pigs showed acinar fibrotic atrophy but normal islets and β-cell morphology. The EPI pigs displayed increased fasting glucose concentrations compared with control animals (6.4 ± 0.4 versus 4.8 ± 0.1 mmol l(-1) , P < 0.0001) but unchanged insulin concentrations (2.4 ± 0.6 versus 2.1 ± 0.2 pmol l(-1) ). During the OGTT and IVGTT, the EPI pigs showed slower, impaired glucose utilization, with the disruption of a well-timed insulin response. Plasma C-peptide concentrations confirmed the delayed insulin response during the IVGTT in EPI pigs. Oral pancreatic enzyme supplementation (PES) of EPI pigs improved glucose clearance during IVGTT [AUC(glucose) 1295 ± 70 mmol l(-1) × (120 min) in EPI versus 1044 ± 32 mmol l(-1) × (120 min) in EPI + PES, P < 0.0001] without reinforcing the release of insulin [AUC(C-peptide) 14.4 ± 3.8 nmol l(-1) × (120 min) in EPI versus 6.4 ± 1.3 nmol l(-1) × (120 min) in EPI + PES, P < 0.002]. The results suggest the existence of an acino-insular axis regulatory communication. The presence of pancreatic enzymes in the gut facilitates glucose utilization in an insulin-independent manner, indicating the existence of a gut-derived pancreatic enzyme-dependent mechanism involved in peripheral glucose utilization. PMID:26663041

  11. Improvement of glucose metabolism in patients with type II diabetes after treatment with a hemodialysate.

    PubMed

    Jacob, S; Dietze, G J; Machicao, F; Kuntz, G; Augustin, H J

    1996-03-01

    Insulin resistance of skeletal muscle glucose uptake is a prominent feature of Type II diabetes (NIDDM); therefore, pharmacological intervention should aim to improve insulin sensitivity. Previous studies have shown that Actovegin, a hemodialysate of calf blood, which has been used for treatment of circulatory disorders for many years, improves glucose tolerance in NIDDM without affecting insulin levels; in vitro studies found an improvement of insulin-stimulated glucose uptake in adipocytes. This pilot study was initiated to see whether this compound augments insulin sensitivity after repeated treatment. Ten patients with NIDDM received the hemodialysate (Actovegin 2.000 pro infusions, 500 ml as daily infusions) over a period of 10 days. A hyperinsulinaemic, isoglycaemic glucose-clamp was done on day 0 and day 11; oral glucose tolerance test (oGTT) was done on day -4 and day 12. Parenteral administration of the hemodialysate markedly augmented insulin stimulated glucose disposal (glucose infusion rate and metabolic clearance rate) by more than 80% (p < 0.003 day 11 vs. day 0). Although tested 44 h after the last infusion, oGTT also improved significantly, as documented by the diminished area under the curve (AUC) for glucose, whereas the AUC for insulin remained unchanged. This is the first clinical study to show that parenteral administration of the tested hemodialysate results in a significant increase of insulin-stimulated glucose disposal in NIDDM. The exact mode of action of the hemodialysate in improving insulin sensitivity is currently not known. The hemodialysate possibly acts via a supplementation of inositol-phosphate-oligosaccharides (IPO), as in experimental studies IPOs isolated from the hemodialysate improved glucose uptake in adipocytes in an insulin-independent manner. Further studies are needed to elucidate the underlying mechanisms. PMID:8901147

  12. Reversal of Early Abnormalities in Glucose Metabolism in Obese Youth: Results of an Intensive Lifestyle Randomized Controlled Trial

    PubMed Central

    Savoye, Mary; Caprio, Sonia; Dziura, James; Camp, Anne; Germain, Greg; Summers, Craig; Li, Fangyong; Shaw, Melissa; Nowicka, Paulina; Kursawe, Romy; DePourcq, Fredrick; Kim, Grace; Tamborlane, William V.

    2014-01-01

    OBJECTIVE The childhood obesity epidemic has been accompanied by an increasing prevalence of type 2 diabetes (T2D), particularly in minority children. Twenty to thirty percent of obese youth have “prediabetes,” a precursor to diabetes marked by insulin resistance, β-cell dysfunction, and impaired glucose tolerance. The Diabetes Prevention Program demonstrated that T2D could be prevented/delayed by intensive lifestyle modification in adults with prediabetes, but efficacy of similar interventions in youth has not been established. Therefore, we evaluated the effects of the Bright Bodies (BB) Healthy Lifestyle Program on 2-h oral glucose tolerance test (OGTT) glucose in comparison with adolescents receiving standard of care. RESEARCH DESIGN AND METHODS A parallel-group randomized controlled trial comparing BB with standard clinical care (CC) in obese adolescents (10–16 years old, Tanner stage >2) with elevated OGTT 2-h blood glucose (130–199 mg/dL) from a racially/ethnically diverse population. OGTTs, including cardiovascular and anthropometric assessments, were conducted at baseline and 6 months. Children attended BB twice per week for exercise and nutrition/behavior modification, and the CC group received CC from their pediatrician. Primary outcome was change in 2-h OGTT glucose and percentage conversion from elevated 2-h blood glucose to nonelevated (<130 mg/dL) 2-h blood glucose. Changes in outcomes were compared between groups using an ANCOVA, with adjustment for baseline outcome and multiple imputation for missing data. RESULTS Reductions in 2-h glucose were more favorable in BB compared with CC (−27.2 vs. −10.1 mg/dL; difference = −17.1, 95% CI; P = 0.005). Moreover, greater conversion to <130 mg/dL 2-h glucose occurred in BB than CC (P = 0.003), and other insulin sensitivity indices were significantly improved. CONCLUSIONS Compared with standard of care, the Yale BB Program is a more effective means of reducing the risk of T2D in obese

  13. A Physiology-Based Model Describing Heterogeneity in Glucose Metabolism

    PubMed Central

    Maas, Anne H.; Rozendaal, Yvonne J. W.; van Pul, Carola; Hilbers, Peter A. J.; Cottaar, Ward J.; Haak, Harm R.; van Riel, Natal A. W.

    2014-01-01

    Background: Current diabetes education methods are costly, time-consuming, and do not actively engage the patient. Here, we describe the development and verification of the physiological model for healthy subjects that forms the basis of the Eindhoven Diabetes Education Simulator (E-DES). E-DES shall provide diabetes patients with an individualized virtual practice environment incorporating the main factors that influence glycemic control: food, exercise, and medication. Method: The physiological model consists of 4 compartments for which the inflow and outflow of glucose and insulin are calculated using 6 nonlinear coupled differential equations and 14 parameters. These parameters are estimated on 12 sets of oral glucose tolerance test (OGTT) data (226 healthy subjects) obtained from literature. The resulting parameter set is verified on 8 separate literature OGTT data sets (229 subjects). The model is considered verified if 95% of the glucose data points lie within an acceptance range of ±20% of the corresponding model value. Results: All glucose data points of the verification data sets lie within the predefined acceptance range. Physiological processes represented in the model include insulin resistance and β-cell function. Adjusting the corresponding parameters allows to describe heterogeneity in the data and shows the capabilities of this model for individualization. Conclusion: We have verified the physiological model of the E-DES for healthy subjects. Heterogeneity of the data has successfully been modeled by adjusting the 4 parameters describing insulin resistance and β-cell function. Our model will form the basis of a simulator providing individualized education on glucose control. PMID:25526760

  14. Cassia Cinnamon Supplementation Reduces Peak Blood Glucose Responses but Does Not Improve Insulin Resistance and Sensitivity in Young, Sedentary, Obese Women.

    PubMed

    Gutierrez, Jean L; Bowden, Rodney G; Willoughby, Darryn S

    2016-07-01

    Cassia cinnamon has been suggested to lower blood glucose (BG) and serum insulin (SI) due to an improvement in insulin resistance (IR) and sensitivity (IS). This study compared the effects Cassia cinnamon had on calculated IR and IS values and BG and SI in response to an oral glucose tolerance test (OGTT) in young, sedentary, and obese women. On three separate days, 10 women had a fasted venous blood sample obtained. Participants were given 5 g of encapsulated placebo (PLC) or 5 g of encapsulated Cassia cinnamon bark (CASS). Three hours after the initial blood sample, another blood sample was obtained to calculate values for IS and IR. The participants then completed an OGTT by consuming a 75 g glucose solution. Blood was obtained 30, 60, 90, and 120 min following glucose ingestion. IS and IR were not significantly different between placebo and Cassia (p > .05). The peak BG concentration in response to the OGTT was significantly lower at the 30 min time point for CASS, as compared to PLC (140 ± 5.8 and 156 ± 5.2 mg/dL, p = .025); however, there was no significant difference between treatments for SI (p > .05). The area-under-the-curve responses for BG and SI were not significantly different between PLC and CASS (p > .05). This study suggests that a 5 g dose of Cassia cinnamon may reduce the peak BG response and improve glucose tolerance following an OGTT, but with no improvement in IS and IR in young, sedentary, obese women. PMID:26716656

  15. CD226 reduces endothelial cell glucose uptake under hyperglycemic conditions with inflammation in type 2 diabetes mellitus

    PubMed Central

    Dong, Zilong; Zhang, Jinxue; Sun, Yizheng; Jin, Boquan; Gao, Feng; Guo, Shuzhong; Zhuang, Ran

    2016-01-01

    CD226 is a co-stimulatory adhesion molecule found on immune and endothelial cells. Here, we evaluated a possible role for CD226 in inhibiting glucose uptake in isolated human umbilical vein endothelial cells (HUVECs) and in wild-type (WT) and CD226 knockout (KO) mice with high-fat diet (HFD)-induced type 2 diabetes (T2DM). CD226 expression increased under hyperglycemic conditions in the presence of TNF-α. Furthermore, CD226 knockdown improved glucose uptake in endothelial cells, and CD226 KO mice exhibited increased glucose tolerance. Levels of soluble CD226 in plasma were higher in T2DM patients following an oral glucose tolerance test (OGTT) than under fasting conditions. Our results indicate that low-grade inflammation coupled with elevated blood glucose increases CD226 expression, resulting in decreased endothelial cell glucose uptake in T2DM. PMID:26910838

  16. Short-Term Regulation of Lipocalin-2 but not RBP-4 During Oral Lipid Tolerance Test and Oral Glucose Tolerance Test.

    PubMed

    Schmid, A; Leszczak, S; Ober, I; Schäffler, A; Karrasch, T

    2016-02-01

    The postprandial regulation of lipocalin-2 and retinol binding protein-4 (RBP-4) by oral uptake of lipids and carbohydrates in healthy individuals has not yet been investigated. The regulation of lipocalin-2 and RBP-4 in 2 large cohorts of healthy volunteers during oral lipid tolerance test (OLTT; n=100) and oral glucose tolerance test (OGTT; n=100) was analyzed. One hundred healthy volunteers underwent OLTT and OGTT in an outpatient setting. Venous blood was drawn after 0, 2, 4, and 6 h in OLTT and after 0, 1, and 2 h in OGTT. In order to dissect carbohydrate-induced from lipid-induced effects, a novel OLTT solution completely free of carbohydrates and protein was applied. Subjects were characterized by anthropometric and laboratory parameters. Serum concentrations of lipocalin-2 and RBP-4 were measured by enzyme-linked immunosorbent assay (ELISA). Whereas RBP-4 levels remained unchanged during OGTT, lipocalin-2 concentrations significantly decreased during OGTT. During OLTT, RBP-4 levels were not influenced, whereas lipocalin-2 levels decreased significantly and stepwise. Fasting concentrations of RBP-4 were negatively correlated with BMI and waist-hip ratio, whereas lipocalin-2 levels were positively associated with BMI and waist-hip ratio. Female users of hormonal contraception had higher RBP-4 levels than females not on contraceptives. There is no significant short-term regulation of RBP-4 by orally ingested lipids or carbohydrates. Lipocalin-2 is downregulated after lipid and carbohydrate ingestion and this kind of regulation was not predicted by age, sex, triglycerides, glucose, or insulin levels. PMID:26069091

  17. Impaired glucose metabolism in HIV-infected pregnant women: a retrospective analysis.

    PubMed

    Moore, Rebecca; Adler, Hugh; Jackson, Valerie; Lawless, Mairead; Byrne, Maria; Eogan, Maeve; Lambert, John S

    2016-06-01

    Metabolic complications, including diabetes mellitus, have been increasingly recognised in HIV-infected individuals since the introduction of antiretroviral therapy, particularly protease inhibitors (PIs). Pregnancy is also a risk factor for impaired glucose metabolism, and previous studies have given conflicting results regarding the contribution of PIs to impaired glucose tolerance (IGT) and gestational diabetes mellitus (GDM) in pregnant HIV-infected women. We conducted a retrospective review of all HIV-infected women attending a combined infectious disease and antenatal clinic between 2007 and 2013 who underwent a 100 g oral glucose tolerance test (OGTT) at 24-28 weeks. We grouped the patients based on whether their OGTT result was normal or abnormal, and compared the groups using standard parametric tests (t-test and Fisher's exact test). Of 263 women with HIV who attended the clinic, 142 (53.9%) attended for OGTT and were eligible for inclusion. The mean age was 31 years (SD 5.37), all women were of European or African origin and 33.7% had a body mass index ≥30 kg/m(2) About 93.7% were on PI-based regimens. At delivery, the mean CD4 count was 526 cells/µL, and 13% of patients had a detectable viraemia. The prevalence of IGT was 2.8%, while the prevalence of GDM was 2.1%. Also, 71.4% (n = 5) of women with abnormal glucose metabolism were taking PIs versus 94.8% (n = 128) of normoglycaemic women (p = 0.06). We did not confirm an increased rate of GDM in HIV-infected women in our patient population and found no association between PI use and GDM. PMID:25999164

  18. Neuroendocrine responses to a glucose challenge in substance users with high and low levels of aggression, impulsivity, and antisocial personality.

    PubMed

    Fishbein, D H; Dax, E; Lozovsky, D B; Jaffe, J H

    1992-01-01

    Plasma glucose concentrations, and plasma prolactin and cortisol responses to a 5-hour oral glucose tolerance test (OGTT) in 37 substance abusers, were examined to assess the relationship between varying degrees of antisocial personality, impulsivity, and aggressiveness and measures of endocrine function. Childhood and presenting aggression, impulsivity and antisocial personality features were evaluated by several self-report questionnaires. Those with high scores for psychopathic deviance (MMPI) differed in glucose levels following OGTT from those with low scores. Lower cortisol nadir levels were associated with higher scores on measures of antisocial personality and aggressiveness. Also, prolactin response to glucose was attenuated relative to baseline levels in the more antisocial and aggressive subjects. The results indicate that substance abusers with high levels of self-reported antisocial personality and aggressive behavior have altered neuroendocrine responses to glucose challenge, although there was no evidence of hypoglycemia. No one personality or behavioral trait, as measured by our test battery, more strongly predicted neuroendocrine responses to glucose administration. Thus, our data partially support other reports of altered neuroendocrine responses to stressful challenges in aggressive/antisocial individuals. PMID:1625777

  19. Statistical analysis and multi-instrument overview of the quasi-periodic 1-hour pulsations in Saturn's outer magnetosphere

    NASA Astrophysics Data System (ADS)

    Palmaerts, B.; Roussos, E.; Krupp, N.; Kurth, W. S.; Mitchell, D. G.; Dougherty, M. K.

    2015-10-01

    The in-situ exploration of the magnetospheres of Jupiter and Saturn has revealed different periodic processes. In particular, in the Saturnian magnetosphere, several studies have reported pulsations in the outer magnetosphere with a periodicity of about 1 hour in the measurements of charged particle fluxes, plasma wave, magnetic field strength and auroral emissions brightness. The Low- Energy Magnetospheric Measurement System detector of the Magnetospheric Imaging Instrument (MIMI/LEMMS) on board Cassini regularly detects 1-hour quasi-periodic enhancements in the intensities of electrons with an energy range from a hundred keV to several MeV. We extend an earlier survey of these relativistic electron injections, using 10 years of LEMMS observations in addition to context measurements by several other Cassini magnetospheric experiments. During this period, we identified 720 pulsed events in the outer magnetosphere over a wide range of latitudes and local times, revealing that this phenomenon is common and frequent in Saturn's magnetosphere. However, the distribution of the injection events presents a strong local time asymmetry with ten times more events in the duskside than in the dawnside. In addition to the study of their topology, we present a first statistical analysis of these pulsed events to investigate their properties. This analysis reveals that the mean interpulse period is 68 ± 10 minutes and that the events are made up of less than 9 pulses in general, but they can include up to 19 pulses. The most common shape of these pulses is a fast rise followed by a slow decay. Moreover, the ratio between the rise rate and the decay rate increases with the energy. We have also investigated the signatures of each electron injection event in the observations acquired by the Radio and Plasma Wave Science (RPWS) instrument and the magnetometer (MAG). Correlated pulsed signatures are observed in the plasma wave emissions, especially in the auroral hiss, for 12% of the

  20. An Integrated 0-1 Hour First-Flash Lightning Nowcasting, Lightning Amount and Lightning Jump Warning Capability

    NASA Technical Reports Server (NTRS)

    Mecikalski, John; Jewett, Chris; Carey, Larry; Zavodsky, Brad; Stano, Geoffrey; Chronis, Themis

    2015-01-01

    Using satellite-based methods that provide accurate 0-1 hour convective initiation (CI) nowcasts, and rely on proven success coupling satellite and radar fields in the Corridor Integrated Weather System (CIWS; operated and developed at MIT-Lincoln Laboratory), to subsequently monitor for first-flash lightning initiation (LI) and later period lightning trends as storms evolve. Enhance IR-based methods within the GOES-R CI Algorithm (that must meet specific thresholds for a given cumulus cloud before the cloud is considered to have an increased likelihood of producing lightning next 90 min) that forecast LI. Integrate GOES-R CI and LI fields with radar thresholds (e.g., first greater than or equal to 40 dBZ echo at the -10 C altitude) and NWP model data within the WDSS-II system for LI-events from new convective storms. Track ongoing lightning using Lightning Mapping Array (LMA) and pseudo-Geostationary Lightning Mapper (GLM) data to assess per-storm lightning trends (e.g., as tied to lightning jumps) and outline threat regions. Evaluate the ability to produce LI nowcasts through a "lightning threat" product, and obtain feedback from National Weather Service forecasters on its value as a decision support tool.

  1. Dietary Fatty Acids Differentially Associate with Fasting Versus 2-Hour Glucose Homeostasis: Implications for The Management of Subtypes of Prediabetes

    PubMed Central

    Guess, Nicola; Perreault, Leigh; Kerege, Anna; Strauss, Allison; Bergman, Bryan C.

    2016-01-01

    Over-nutrition has fuelled the global epidemic of type 2 diabetes, but the role of individual macronutrients to the diabetogenic process is not well delineated. We aimed to examine the impact of dietary fatty acid intake on fasting and 2-hour plasma glucose concentrations, as well as tissue-specific insulin action governing each. Normoglycemic controls (n = 15), athletes (n = 14), and obese (n = 23), as well as people with prediabetes (n = 10) and type 2 diabetes (n = 11), were queried about their habitual diet using a Food Frequency Questionnaire. All subjects were screened by an oral glucose tolerance test (OGTT) and studied using the hyperinsulinemic/euglycemic clamp with infusion of 6,62H2-glucose. Multiple regression was performed to examine relationships between dietary fat intake and 1) fasting plasma glucose, 2) % suppression of endogenous glucose production, 3) 2-hour post-OGTT plasma glucose, and 4) skeletal muscle insulin sensitivity (glucose rate of disappearance (Rd) and non-oxidative glucose disposal (NOGD)). The %kcal from saturated fat (SFA) was positively associated with fasting (β = 0.303, P = 0.018) and 2-hour plasma glucose (β = 0.415, P<0.001), and negatively related to % suppression of hepatic glucose production (β = -0.245, P = 0.049), clamp Rd (β = -0.256, P = 0.001) and NOGD (β = -0.257, P = 0.001). The %kcal from trans fat was also negatively related to clamp Rd (β = -0.209, P = 0.008) and NOGD (β = -0.210, P = 0.008). In contrast, the %kcal from polyunsaturated fat (PUFA) was negatively associated with 2-hour glucose levels (β = -0.383, P = 0.001), and positively related to Rd (β = 0.253, P = 0.007) and NOGD (β = 0.246, P = 0.008). Dietary advice to prevent diabetes should consider the underlying pathophysiology of the prediabetic state. PMID:26999667

  2. Dietary Fatty Acids Differentially Associate with Fasting Versus 2-Hour Glucose Homeostasis: Implications for The Management of Subtypes of Prediabetes.

    PubMed

    Guess, Nicola; Perreault, Leigh; Kerege, Anna; Strauss, Allison; Bergman, Bryan C

    2016-01-01

    Over-nutrition has fuelled the global epidemic of type 2 diabetes, but the role of individual macronutrients to the diabetogenic process is not well delineated. We aimed to examine the impact of dietary fatty acid intake on fasting and 2-hour plasma glucose concentrations, as well as tissue-specific insulin action governing each. Normoglycemic controls (n = 15), athletes (n = 14), and obese (n = 23), as well as people with prediabetes (n = 10) and type 2 diabetes (n = 11), were queried about their habitual diet using a Food Frequency Questionnaire. All subjects were screened by an oral glucose tolerance test (OGTT) and studied using the hyperinsulinemic/euglycemic clamp with infusion of 6,62H2-glucose. Multiple regression was performed to examine relationships between dietary fat intake and 1) fasting plasma glucose, 2) % suppression of endogenous glucose production, 3) 2-hour post-OGTT plasma glucose, and 4) skeletal muscle insulin sensitivity (glucose rate of disappearance (Rd) and non-oxidative glucose disposal (NOGD)). The %kcal from saturated fat (SFA) was positively associated with fasting (β = 0.303, P = 0.018) and 2-hour plasma glucose (β = 0.415, P<0.001), and negatively related to % suppression of hepatic glucose production (β = -0.245, P = 0.049), clamp Rd (β = -0.256, P = 0.001) and NOGD (β = -0.257, P = 0.001). The %kcal from trans fat was also negatively related to clamp Rd (β = -0.209, P = 0.008) and NOGD (β = -0.210, P = 0.008). In contrast, the %kcal from polyunsaturated fat (PUFA) was negatively associated with 2-hour glucose levels (β = -0.383, P = 0.001), and positively related to Rd (β = 0.253, P = 0.007) and NOGD (β = 0.246, P = 0.008). Dietary advice to prevent diabetes should consider the underlying pathophysiology of the prediabetic state. PMID:26999667

  3. In vivo interstitial glucose characterization and monitoring in the skin by ATR-FTIR spectroscopy

    NASA Astrophysics Data System (ADS)

    Skrebova Eikje, Natalja

    2011-03-01

    Successful development of real-time non-invasive glucose monitoring would represent a major advancement not only in the treatment and management of patients with diabetes mellitus and carbohydrate metabolism disorders, but also for understanding in those biochemical, metabolic and (patho-)physiological processes of glucose at the molecular level in vivo. Here, ATR-FTIR spectroscopy technique has been challenged not only for in vivo measurement of interstitial glucose levels, but also for their non-invasive molecular qualitative and quantitative comparative characterization in the skin tissue. The results, based on calculated mean values of determined 5 glucose-specific peaks in the glucose-related 1000-1160 cm-1 region, showed intra- and inter-subject differences in interstitial glucose activity levels with their changes at different times and doses of OGTT, while raising questions about the relationships between interstitial and blood glucose levels. In conclusion, the introduction of ATR-FTIR spectroscopy technique has opened up an access to the interstitial fluid space in the skin tissue for interstitial glucose characterization and monitoring in vivo. Though interstitial versus blood glucose monitoring has different characteristics, it can be argued that accurate and precise measurements of interstitial glucose levels may be more important clinically.

  4. Serum progranulin concentrations are not responsive during oral lipid tolerance test and oral glucose tolerance test.

    PubMed

    Schmid, A; Leszczak, S; Ober, I; Schäffler, A; Karrasch, T

    2015-07-01

    The postprandial regulation of progranulin by oral uptake of lipids and carbohydrates in healthy individuals has not yet been investigated. The regulation of progranulin in 2 large cohorts of healthy volunteers during oral lipid tolerance test (OLTT; n=100) and oral glucose tolerance test (OGTT; n=100) was analyzed. One hundred healthy volunteers underwent OLTT and OGTT in an outpatient setting. Venous blood was drawn at 0 hours (h) (fasting) and at 2, 4, and 6 h in OLTT or 1 and 2 h in OGTT. A novel OLTT solution completely free of carbohydrates and protein was applied. Subjects were characterized by anthropometric and laboratory parameters. Serum concentrations of progranulin were measured by enzyme-linked immunosorbent assay (ELISA). Circulating progranulin levels remained unchanged during OLTT and OGTT. Fasting progranulin levels ranged between 31.3±8.7 and 40.6±7.7 ng/ml and were not different in subgroups addressing BMI, gender, family history, smoking habits, and hormonal contraception. There was a reciprocal correlation of progranulin with HDL (negative) and LDL cholesterol levels (positive). In healthy adults, fasting and postprandial circulating progranulin levels are not different in BMI subgroups. Oral uptake of carbohydrates and lipids does not influence circulating progranulin levels in a short-term manner. A postprandial and short-term regulation of this adipokine is absent, at least in healthy subjects. There is a negative correlation of progranulin with HDL cholesterol, but a positive correlation with LDL cholesterol. This reciprocal association might be of physiological importance for an individual's atherosclerotic risk. PMID:25565096

  5. Impaired Glucose Tolerance or Newly Diagnosed Diabetes Mellitus Diagnosed during Admission Adversely Affects Prognosis after Myocardial Infarction: An Observational Study

    PubMed Central

    George, Anish; Bhatia, Raghav T.; Buchanan, Gill L.; Whiteside, Anne; Moisey, Robert S.; Beer, Stephen F.; Chattopadhyay, Sudipta; Sathyapalan, Thozhukat; John, Joseph

    2015-01-01

    Objective To investigate the prognostic effect of newly diagnosed diabetes mellitus (NDM) and impaired glucose tolerance (IGT) post myocardial infarction (MI). Research Design and Methods Retrospective cohort study of 768 patients without preexisting diabetes mellitus post-MI at one centre in Yorkshire between November 2005 and October 2008. Patients were categorised as normal glucose tolerance (NGT n = 337), IGT (n = 279) and NDM (n = 152) on pre- discharge oral glucose tolerance test (OGTT). Primary end-point was the first occurrence of major adverse cardiovascular events (MACE) including cardiovascular death, non-fatal MI, severe heart failure (HF) or non-haemorrhagic stroke. Secondary end-points were all cause mortality and individual components of MACE. Results Prevalence of NGT, impaired fasting glucose (IFG), IGT and NDM changed from 90%, 6%, 0% and 4% on fasting plasma glucose (FPG) to 43%, 1%, 36% and 20% respectively after OGTT. 102 deaths from all causes (79 as first events of which 46 were cardiovascular), 95 non fatal MI, 18 HF and 9 non haemorrhagic strokes occurred during 47.2 ± 9.4 months follow up. Event free survival was lower in IGT and NDM groups. IGT (HR 1.54, 95% CI: 1.06–2.24, p = 0.024) and NDM (HR 2.15, 95% CI: 1.42–3.24, p = 0.003) independently predicted MACE free survival. IGT and NDM also independently predicted incidence of MACE. NDM but not IGT increased the risk of secondary end-points. Conclusion Presence of IGT and NDM in patients presenting post-MI, identified using OGTT, is associated with increased incidence of MACE and is associated with adverse outcomes despite adequate secondary prevention. PMID:26571120

  6. Peptide hormones in saliva. I. Insulin in saliva during the oral glucose tolerance test in female patients.

    PubMed

    Simionescu, L; Aman, E; Muşeţeanu, P; Dinulescu, E; Giurcăneanu, M

    1985-01-01

    The radioimmunoassay (RIA) of insulin was performed in the serum and saliva of 27 female patients during the oral glucose tolerance test (OGTT). The patients were divided into two groups: 19 non-diabetic patients and 8 patients diagnosed as impaired glucose tolerance (IGT) disease. In one patient in each group, the OGTT was performed twice at intervals of 3-5 days. The results show that immunoreactive insulin (IRI) is present in saliva and its concentration increases during the glucose stimulation test from 6.48 +/- 1.13 microU/ml (means +/- SEM) in basal conditions at peak values of 45.46 +/- 10.14 microU/ml at 2 hrs after glucose intake. In patients with IGT salivary IRI increases from 5.18 +/- 1.39 microU/ml in basal conditions to peak values of 83.34 +/- 25.85 microU/ml at 3 hrs after glucose administration. Great response variations were observed either inter-individual or intraindividual in both groups of patients. Some patients had unusual high salivary IRI concentration especially in those with gastrointestinal troubles. Further, some hypotheses and experimental models, are advanced, considered useful for the explanation of the physiologic significance of the salivary IRI or of the IRI-like material. PMID:3901231

  7. Effects of colesevelam on glucose absorption and hepatic/peripheral insulin sensitivity in patients with type 2 diabetes mellitus

    PubMed Central

    Henry, R. R.; Aroda, V. R.; Mudaliar, S.; Garvey, W. T.; Chou, H. S.; Jones, M. R.

    2016-01-01

    Aim Colesevelam lowers glucose and low-density lipoprotein cholesterol levels in patients with type 2 diabetes mellitus. This study examined the mechanisms by which colesevelam might affect glucose control. Methods In this 12-week, randomized, double-blind, placebo-controlled study, subjects with type 2 diabetes and haemoglobin A1c(HbA1c) ≥7.5% on either stable diet and exercise or sulphonylurea therapy were randomized to colesevelam 3.75 g/day (n = 16) or placebo (n = 14). Hepatic/peripheral insulin sensitivity was evaluated at baseline and at week 12 by infusion of 3H-labelled glucose followed by a 2-step hyperinsulinemic–euglycemic clamp. Two 75-g oral glucose tolerance tests (OGTTs) were conducted at baseline, one with and one without co-administration of colesevelam. A final OGTT was conducted at week 12. HbA1c and fasting plasma glucose (FPG) levels were evaluated pre-and post-treatment. Results Treatment with colesevelam, compared to placebo, had no significant effects on basal endogenous glucose output, response to insulin or on maximal steady-state glucose disposal rate. At baseline, co-administration of colesevelam with oral glucose reduced total area under the glucose curve (AUCg) but not incremental AUCg. At week 12, neither total AUCg nor incremental AUCg were changed from pre-treatment values in either group. Post-load insulin levels increased with colesevelam at 30 and 120 min, but these changes in total area under the insulin curve (AUCi) and incremental AUCi did not differ between groups. Both HbA1c and FPG improved with colesevelam, but treatment differences were not significant. Conclusions Colesevelam does not affect hepatic or peripheral insulin sensitivity and does not directly affect glucose absorption. PMID:21831167

  8. Possibility to predict early postpartum glucose abnormality following gestational diabetes mellitus based on the results of routine mid-gestational screening

    PubMed Central

    Bartáková, Vendula; Malúšková, Denisa; Mužík, Jan; Bělobrádková, Jana; Kaňková, Kateřina

    2015-01-01

    Introduction Women with previous gestational diabetes mellitus (GDM) have increased risk of developing glucose abnormality, but current diagnostic criteria are evidence-based for adverse pregnancy outcome. The aims of our study were: (i) to ascertain a frequency of early conversion of GDM into permanent glucose abnormality, (ii) to determine predictive potential of current GDM diagnostic criteria for prediction of postpartum glucose abnormality and (iii) to find optimal cut-off values of oral glucose tolerance test (oGTT) to stratify GDM population according to postpartum risk. Materials and methods Electronic medical records of an ethnically homogenous cohort of women diagnosed and treated for GDM in a single medical centre during the period 2005–2011 who completed postpartum oGTT up to 1 year after the index delivery were retrospectively analysed (N = 305). Results Postpartum glucose abnormality was detected in 16.7% subjects. Mid-trimester oGTT values, respective area under the curve and HbA1c were significantly associated with early postpartum glucose abnormality (P < 0.05, Mann-Whitney) and exhibited significant predictive potential for postpartum glucose abnormality risk assessment. Optimal cut-off values for discrimination of at-risk sub-population were identified using ROC analysis and their comparison with WHO and IADPSG criteria exhibited superiority of IADPSG for risk-stratification of GDM population. Conclusion Risk-based stratification at the time of GDM diagnosis could improve efficiency of the post-gestational screening for diabetes. IADPSG criteria seem to optimally capture both perinatal and maternal metabolic risks and are therefore medically and economically justified. PMID:26526166

  9. GOES Infrared and Reflectance 0-1 hour Lightning Initiation Indicators: Development and Initial Testing within a Convective Nowcasting System

    NASA Astrophysics Data System (ADS)

    Mecikalski, J. R.; Harris, R.; MacKenzie, W.; Durkee, P. A.; Iskenderian, H.; Bickmeier, L.; Nielsen, K. E.

    2010-12-01

    Within cumulus cloud fields that develop in conditionally unstable air masses, only a fraction of the cumuli may eventually develop into deep convection. Identifying which of these convective clouds most likely to generate lightning often starts with little more than a qualitative visual satellite analysis. The goal of this study is to identify the observed satellite infrared (IR) signatures associated with growing cumulus clouds prior to the first lightning strike, so-called lightning initiation (LI). This study quantifies the behavior of ten Geostationary Operational Environmental Satellite (GOES-12) IR interest fields in the 1-hour in advance of LI. A total of 172 lightning-producing storms that occurred during the 2009 convective season are manually tracked and studied over four regions: Northern Alabama, Central Oklahoma, the Kennedy Space Center and Washington D.C. Four-dimensional and cloud-to-ground lightning array data provide a total cloud lightning picture (in-cloud, cloud-to-cloud, cloud-to-air, cloud-to-ground) and thus precise LI points for each storm in both time and space. Statistical significance tests are conducted on observed trends for each of the ten LI fields to determine the unique information each field provides in terms of behavior prior to LI. Eight out of ten LI fields exhibited useful information at least 15 min in advance of LI, with 35 min being the average. Statistical tests on these eight fields are compared for separate large geographical areas. IR temperature thresholds are then determined as an outcome, which may be valuable when implementing a LI prediction algorithm into real-time satellite-based systems. The key LI indicators from GOES IR data (as well as 3.9 μm reflectance) will be presented. Beginning in 2010, the feasibility of using the satellite-based LI indicators found in the above analysis to forecast first lightning will be assessed within the Federal Aviation Administration’s (FAA) CoSPA nowcasting system. The goal

  10. Statistical analysis and multi-instrument overview of the quasi-periodic 1-hour pulsations in Saturn's outer magnetosphere

    NASA Astrophysics Data System (ADS)

    Palmaerts, B.; Roussos, E.; Krupp, N.; Kurth, W. S.; Mitchell, D. G.; Yates, J. N.

    2016-06-01

    The in-situ exploration of the magnetospheres of Jupiter and Saturn has revealed different periodic processes. In particular, in the Saturnian magnetosphere, several studies have reported pulsations in the outer magnetosphere with a periodicity of about 1 h in the measurements of charged particle fluxes, plasma wave, magnetic field strength and auroral emissions brightness. The Low-Energy Magnetospheric Measurement System detector of the Magnetospheric Imaging Instrument (MIMI/LEMMS) on board Cassini regularly detects 1-hour quasi-periodic enhancements in the intensities of electrons with an energy range from a hundred keV to several MeV. We extend an earlier survey of these relativistic electron injections using 10 years of LEMMS observations in addition to context measurements by several other Cassini magnetospheric experiments. The one-year extension of the data and a different method of detection of the injections do not lead to a discrepancy with the results of the previous survey, indicating an absence of a long-term temporal evolution of this phenomenon. We identified 720 pulsed events in the outer magnetosphere over a wide range of latitudes and local times, revealing that this phenomenon is common and frequent in Saturn's magnetosphere. However, the distribution of the injection events presents a strong local time asymmetry with ten times more events in the duskside than in the dawnside. In addition to the study of their topology, we present a first statistical analysis of the pulsed events properties. The morphology of the pulsations shows a weak local time dependence which could imply a high-latitude acceleration source. We provide some clues that the electron population associated with this pulsed phenomenon is distinct from the field-aligned electron beams previously observed in Saturn's magnetosphere, but both populations can be mixed. We have also investigated the signatures of each electron injection event in the observations acquired by the Radio

  11. An Integrated 0-1 Hour First-Flash Lightning Nowcasting, Lightning Amount and Lightning Jump Warning Capability

    NASA Technical Reports Server (NTRS)

    Mecikalski, John; Jewett, Chris; Carey, Larry; Zavodsky, Brad; Stano, Geoffrey

    2015-01-01

    Lightning one of the most dangerous weather-related phenomena, especially as many jobs and activities occur outdoors, presenting risk from a lightning strike. Cloud-to-ground (CG) lightning represents a considerable safety threat to people at airfields, marinas, and outdoor facilities-from airfield personnel, to people attending outdoor stadium events, on beaches and golf courses, to mariners, as well as emergency personnel. Holle et al. (2005) show that 90% of lightning deaths occurred outdoors, while 10% occurred indoors despite the perception of safety when inside buildings. Curran et al. (2000) found that nearly half of fatalities due to weather were related to convective weather in the 1992-1994 timeframe, with lightning causing a large component of the fatalities, in addition to tornadoes and flash flooding. Related to the aviation industry, CG lightning represents a considerable hazard to baggage-handlers, aircraft refuelers, food caterers, and emergency personnel, who all become exposed to the risk of being struck within short time periods while convective storm clouds develop. Airport safety protocols require that ramp operations be modified or discontinued when lightning is in the vicinity (typically 16 km), which becomes very costly and disruptive to flight operations. Therefore, much focus has been paid to nowcasting the first-time initiation and extent of lightning, both of CG and of any lightning (e.g, in-cloud, cloud-to-cloud). For this project three lightning nowcasting methodologies will be combined: (1) a GOESbased 0-1 hour lightning initiation (LI) product (Harris et al. 2010; Iskenderian et al. 2012), (2) a High Resolution Rapid Refresh (HRRR) lightning probability and forecasted lightning flash density product, such that a quantitative amount of lightning (QL) can be assigned to a location of expected LI, and (3) an algorithm that relates Pseudo-GLM data (Stano et al. 2012, 2014) to the so-called "lightning jump" (LJ) methodology (Shultz et al

  12. [Effect of coal tar on cignolin erythema--1 hour treatment of psoriasis with high-dose cignolin with and without tar].

    PubMed

    Schauder, S; Mahrle, G

    1985-06-01

    Coal tar applied simultaneously showed a suppressive effect on anthralin erythema. This effect was demonstrated by an epicutaneous test 24 hours (27 patients) and 1 hour (46 patients) after application of various concentrations of anthralin combined with tar 3%. In a clinical study on 9 patients, anthralin 3% alone or combined with tar 10% were administered in a right and left comparison on symmetrical chronic psoriatic lesions for 1 hour daily. Anthralin plus tar exhibited a stronger anti-psoriatic effect than anthralin alone did. Tar reduced the anthralin erythema in the perilesional skin. These findings favor the combination of coal tar and anthralin in the 1-hour treatment schedule of psoriasis. PMID:3160177

  13. Assessment of incretins in oral glucose and lipid tolerance tests may be indicative in the diagnosis of metabolic syndrome aggravation.

    PubMed

    Kiec-Klimczak, M; Malczewska-Malec, M; Razny, U; Zdzienicka, A; Gruca, A; Goralska, J; Pach, D; Gilis-Januszewska, A; Dembinska-Kiec, A; Hubalewska-Dydejczyk, A

    2016-04-01

    Incretins stimulated by oral meals are claimed to be protective for the pancreatic beta cells, to increase insulin secretion, to inhibit glucagon release, slow gastric emptying (glucagon-like peptide-1) and suppress appetite. Recently it has however been suggested that glucagon-like peptide-1 (GLP-1) is putative early biomarker of metabolic consequences of the obesity associated proinflammatory state. The study was aimed to compare the release of incretins and some of early markers of inflammation at the fasting and postprandial period induced by functional oral glucose as well as lipid load in healthy controls and patients with metabolic syndrome (MS) to see if functional tests may be helpful in searching for the inflammatory status of patients. Fifty patients with MS and 20 healthy volunteers (C) participated in this study. The 3-hour oral glucose (OGTT) and the 8-hour oral lipid (OLTT) tolerance tests were performed. At fasting leptin and adiponectin, as well as every 30 minutes of OGTT and every 2 hours of OLTT blood concentration of GLP-1, glucose-dependent insulinotropic polypeptide (GIP), glucose, insulin, triglycerides, free fatty acids, glutathione peroxidase, interleukin-6, sE-selectin, monocyte chemoattractant protein-1 (MCP1) and visfatin were measured. At fasting and during both OGTT and OLTT the level of incretins did not differ between the MS and the C group. Both glucose and lipids reach food activated incretins secretion. Glucose was the main GLP-1 release activator, while the lipid load activated evidently GIP secretion. A significantly larger AUC-GIP after the lipid-rich meal over the carbohydrate meal was observed, while statistically bigger value of AUC-GLP-1 was noticed in OGTT than in OLTT (P < 0.001) within each of the investigated groups. In patients with the highest fasting plasma GIP concentration (3(rd) tertile), IL-6, MCP-1, sE-selectin and visfatin blood levels were increased and correlated with glutathione peroxydase, leptin

  14. Detailed Physiologic Characterization Reveals Diverse Mechanisms for Novel Genetic Loci Regulating Glucose and Insulin Metabolism in Humans

    PubMed Central

    Ingelsson, Erik; Langenberg, Claudia; Hivert, Marie-France; Prokopenko, Inga; Lyssenko, Valeriya; Dupuis, Josée; Mägi, Reedik; Sharp, Stephen; Jackson, Anne U.; Assimes, Themistocles L.; Shrader, Peter; Knowles, Joshua W.; Zethelius, Björn; Abbasi, Fahim A.; Bergman, Richard N.; Bergmann, Antje; Berne, Christian; Boehnke, Michael; Bonnycastle, Lori L.; Bornstein, Stefan R.; Buchanan, Thomas A.; Bumpstead, Suzannah J.; Böttcher, Yvonne; Chines, Peter; Collins, Francis S.; Cooper, Cyrus C.; Dennison, Elaine M.; Erdos, Michael R.; Ferrannini, Ele; Fox, Caroline S.; Graessler, Jürgen; Hao, Ke; Isomaa, Bo; Jameson, Karen A.; Kovacs, Peter; Kuusisto, Johanna; Laakso, Markku; Ladenvall, Claes; Mohlke, Karen L.; Morken, Mario A.; Narisu, Narisu; Nathan, David M.; Pascoe, Laura; Payne, Felicity; Petrie, John R.; Sayer, Avan A.; Schwarz, Peter E. H.; Scott, Laura J.; Stringham, Heather M.; Stumvoll, Michael; Swift, Amy J.; Syvänen, Ann-Christine; Tuomi, Tiinamaija; Tuomilehto, Jaakko; Tönjes, Anke; Valle, Timo T.; Williams, Gordon H.; Lind, Lars; Barroso, Inês; Quertermous, Thomas; Walker, Mark; Wareham, Nicholas J.; Meigs, James B.; McCarthy, Mark I.; Groop, Leif; Watanabe, Richard M.; Florez, Jose C.

    2010-01-01

    OBJECTIVE Recent genome-wide association studies have revealed loci associated with glucose and insulin-related traits. We aimed to characterize 19 such loci using detailed measures of insulin processing, secretion, and sensitivity to help elucidate their role in regulation of glucose control, insulin secretion and/or action. RESEARCH DESIGN AND METHODS We investigated associations of loci identified by the Meta-Analyses of Glucose and Insulin-related traits Consortium (MAGIC) with circulating proinsulin, measures of insulin secretion and sensitivity from oral glucose tolerance tests (OGTTs), euglycemic clamps, insulin suppression tests, or frequently sampled intravenous glucose tolerance tests in nondiabetic humans (n = 29,084). RESULTS The glucose-raising allele in MADD was associated with abnormal insulin processing (a dramatic effect on higher proinsulin levels, but no association with insulinogenic index) at extremely persuasive levels of statistical significance (P = 2.1 × 10−71). Defects in insulin processing and insulin secretion were seen in glucose-raising allele carriers at TCF7L2, SCL30A8, GIPR, and C2CD4B. Abnormalities in early insulin secretion were suggested in glucose-raising allele carriers at MTNR1B, GCK, FADS1, DGKB, and PROX1 (lower insulinogenic index; no association with proinsulin or insulin sensitivity). Two loci previously associated with fasting insulin (GCKR and IGF1) were associated with OGTT-derived insulin sensitivity indices in a consistent direction. CONCLUSIONS Genetic loci identified through their effect on hyperglycemia and/or hyperinsulinemia demonstrate considerable heterogeneity in associations with measures of insulin processing, secretion, and sensitivity. Our findings emphasize the importance of detailed physiological characterization of such loci for improved understanding of pathways associated with alterations in glucose homeostasis and eventually type 2 diabetes. PMID:20185807

  15. Glucose control.

    PubMed

    Preiser, Jean-Charles

    2013-01-01

    Stress-related hyperglycemia is a common finding in acutely ill patients, and is related to the severity and outcome of the critical illness. The pathophysiology of stress hyperglycemia includes hormonal and neural signals, leading to increased production of glucose by the liver and peripheral insulin resistance mediated by the translocation of transmembrane glucose transporters. In one pioneering study, tight glycemic control by intensive insulin therapy in critically ill patients was associated with improved survival. However, this major finding was not confirmed in several other prospective randomized controlled trials. The reasons underlying the discrepancy between the first and the subsequent studies could include nutritional strategy (amount of calories provided, use of parenteral nutrition), case-mix, potential differences in the optimal blood glucose level (BG) in different types of patients, hypoglycemia and its correction, and the magnitude of glucose variability. Therefore, an improved understanding of the physiology and pathophysiology of glycemic regulation during acute illness is needed. Safe and effective glucose control will need improvement in the definition of optimal BG and in the measurement techniques, perhaps including continuous monitoring of insulin algorithms and closed-loop systems. PMID:23075589

  16. Impaired glucose tolerance after brief heat exposure: a randomized crossover study in healthy young men.

    PubMed

    Faure, Cécile; Charlot, Keyne; Henri, Stéphane; Hardy-Dessources, Marie-Dominique; Hue, Olivier; Antoine-Jonville, Sophie

    2016-06-01

    A high demand on thermoregulatory processes may challenge homoeostasis, particularly regarding glucose regulation. This has been understudied, although it might concern millions of humans. The objective of this project was to examine the isolated and combined effects of experimental short-term mild heat exposure and metabolic level on glucoregulation. Two experimental randomized crossover studies were conducted. Ten healthy young men participated in study A, which comprises four sessions in a fasting state at two metabolic levels [rest and exercise at 60% of maximal oxygen uptake (O2) for 40 min] in two environmental temperatures (warm: 31°C and control: 22°C). Each session ended with an ad libitum meal, resulting in similar energy intake across sessions. In study B, 12 healthy young men underwent two 3 h oral glucose tolerance tests (OGTTs) in warm and control environmental temperatures. Venous blood was sampled at several time points. In study A, repeated measure ANOVAs revealed higher postprandial serum glucose and insulin levels with heat exposure. Glycaemia following the OGTT was higher in the warm temperature compared with control. The kinetics of the serum glucose response to the glucose load was also affected by the environmental temperature (temperature-by-time interaction, P=0.030), with differences between the warm and control conditions observed up to 90 min after the glucose load (all P<0.033). These studies provide evidence that heat exposure alters short-term glucoregulation. The implication of this environmental factor in the physiopathology of Type 2 diabetes has yet to be investigated. PMID:26980346

  17. Glucose Variability

    PubMed Central

    2013-01-01

    The proposed contribution of glucose variability to the development of the complications of diabetes beyond that of glycemic exposure is supported by reports that oxidative stress, the putative mediator of such complications, is greater for intermittent as opposed to sustained hyperglycemia. Variability of glycemia in ambulatory conditions defined as the deviation from steady state is a phenomenon of normal physiology. Comprehensive recording of glycemia is required for the generation of any measurement of glucose variability. To avoid distortion of variability to that of glycemic exposure, its calculation should be devoid of a time component. PMID:23613565

  18. 40 CFR 51.905 - How do areas transition from the 1-hour NAAQS to the 8-hour NAAQS and what are the anti...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... Ambient Air Quality Standard § 51.905 How do areas transition from the 1-hour NAAQS to the 8-hour NAAQS...)(3)(iii) of this section. 40 CFR part 81, subpart C identifies the boundaries of areas and the area... obligations approved into the SIP pursuant to 40 CFR 51.121 and 51.122 may be modified by the State only...

  19. 40 CFR 51.905 - How do areas transition from the 1-hour NAAQS to the 8-hour NAAQS and what are the anti...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Ambient Air Quality Standard § 51.905 How do areas transition from the 1-hour NAAQS to the 8-hour NAAQS...)(3)(iii) of this section. 40 CFR part 81, subpart C identifies the boundaries of areas and the area... obligations approved into the SIP pursuant to 40 CFR 51.121 and 51.122 may be modified by the State only...

  20. 40 CFR 51.905 - How do areas transition from the 1-hour NAAQS to the 1997 8-hour NAAQS and what are the anti...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... National Ambient Air Quality Standard § 51.905 How do areas transition from the 1-hour NAAQS to the 1997 8... requirement to submit a maintenance plan for purposes of paragraph (a)(3)(iii) of this section. 40 CFR part 81.... Control obligations approved into the SIP pursuant to 40 CFR 51.121 and 51.122 may be modified by...

  1. 40 CFR 51.905 - How do areas transition from the 1-hour NAAQS to the 1997 8-hour NAAQS and what are the anti...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... National Ambient Air Quality Standard § 51.905 How do areas transition from the 1-hour NAAQS to the 1997 8... requirement to submit a maintenance plan for purposes of paragraph (a)(3)(iii) of this section. 40 CFR part 81.... Control obligations approved into the SIP pursuant to 40 CFR 51.121 and 51.122 may be modified by...

  2. Response to fifty grams oral glucose challenge test and pattern of preceding fasting plasma glucose in normal pregnant Nigerians

    PubMed Central

    Ajayi, Godwin Olufemi

    2014-01-01

    Background: Diabetes mellitus in pregnancy has profound implications for the baby and mother and thus active screening for this is desirable. Method: Fifty grams oral glucose challenge test was administered after obtaining consent to 222 women in good health with singleton pregnancies without diabetes mellitus at 24 to 28 weeks gestation after an overnight fast. Venous blood sample was obtained before and 1 hour after the glucose load. A diagnostic 3-hour 100 g oral glucose tolerance test was subsequently performed in all. Results: Two hundred and ten women had a normal response to oral glucose tolerance test i.e. venous plasma glucose below these cut-off levels: fasting 95 mg/dl (5.3 mmol/l), 1 hour 180 mg/dl (10.0 mmol/l), 2 hours 155 mg/dl (8.6 mmol/l) and 3 hours 140 mg/dl (7.8 mmol/l), while 12 were found to have gestational diabetes mellitus and were subsequently excluded from the study. They were appropriately managed. The mean maternal age was 30.9 ± 4.1 years (range 19 to 45 years) and the mean parity was 1.2 ± 1.1 (range 0 to 5). The mean fasting plasma glucose was 74.5 ± 11.5 mg/dl (range 42 to 117 mg/dl), while the mean plasma glucose 1 hour after 50 g glucose challenge test was 115.3 ± 19.1 mg/dl (range 56 to 180 mg/dl). Conclusions: The mean fasting plasma glucose in normal pregnant Nigerians was 74.5 ± 11.5 mg/dl (range 42 to 117 mg/dl). There is a need to re-appraise and possibly review downwards the World Health Organization fasting plasma glucose diagnostic criteria in pregnant Nigerians for better detection of gestational diabetes mellitus. Pregnant women with venous plasma glucose greater than 153.5 mg/dl (8.5 mmol/l) 1 hour after 50 g glucose challenge test are strongly recommended for diagnostic test of gestational diabetes mellitus.

  3. Whole-Body Insulin Sensitivity Rather than Body-Mass-Index Determines Fasting and Post-Glucose-Load Growth Hormone Concentrations

    PubMed Central

    Anderwald, Christian-Heinz; Tura, Andrea; Gessl, Alois; Smajis, Sabina; Bieglmayer, Christian; Marculescu, Rodrig; Luger, Anton; Pacini, Giovanni; Krebs, Michael

    2014-01-01

    Background Obese, non-acromegalic persons show lower growth hormone (GH) concentrations at fasting and reduced GH nadir during an oral glucose tolerance test (OGTT). However, this finding has never been studied with regard to whole-body insulin-sensitivity as a possible regulator. Methods In this retrospective analysis, non-acromegalic (NonACRO, n = 161) and acromegalic (ACRO, n = 35), non-diabetic subjects were subdivided into insulin-sensitive (IS) and –resistant (IR) groups according to the Clamp-like Index (CLIX)-threshold of 5 mg·kg−1·min−1 from the OGTT. Results Non-acromegalic IS (CLIX: 8.8±0.4 mg·kg−1·min−1) persons with similar age and sex distribution, but lower (p<0.001) body-mass-index (BMI = 25±0 kg/m2, 84% females, 56±1 years) had 59% and 70%, respectively, higher (p<0.03) fasting GH and OGTT GH area under the curve concentrations than IR (CLIX: 3.5±0.1 mg·kg−1·min−1, p<0.001) subjects (BMI = 29±1 kg/m2, 73% females, 58±1 years). When comparing on average overweight non-acromegalic IS and IR with similar anthropometry (IS: BMI: 27±0 kg/m2, 82% females, 58±2 years; IR: BMI: 27±0 kg/m2, 71% females, 60±1 years), but different CLIX (IS: 8.7±0.9 vs. IR: 3.8±0.1 mg·kg−1·min−1, p<0.001), the results remained almost the same. In addition, when adjusted for OGTT-mediated glucose rise, GH fall was less pronounced in IR. In contrast, in acromegalic subjects, no difference was found between IS and IR patients with regard to fasting and post-glucose-load GH concentrations. Conclusions Circulating GH concentrations at fasting and during the OGTT are lower in non-acromegalic insulin-resistant subjects. This study seems the first to demonstrate that insulin sensitivity rather than body-mass modulates fasting and post-glucose-load GH concentrations in non-diabetic non–acromegalic subjects. PMID:25517727

  4. An acute bout of whole body passive hyperthermia increases plasma leptin, but does not alter glucose or insulin responses in obese type 2 diabetics and healthy adults.

    PubMed

    Rivas, Eric; Newmire, Dan E; Crandall, Craig G; Hooper, Philip L; Ben-Ezra, Vic

    2016-07-01

    Acute and chronic hyperthermic treatments in diabetic animal models repeatedly improve insulin sensitivity and glycemic control. Therefore, the purpose of this study was to test the hypothesis that an acute 1h bout of hyperthermic treatment improves glucose, insulin, and leptin responses to an oral glucose challenge (OGTT) in obese type 2 diabetics and healthy humans. Nine obese (45±7.1% fat mass) type 2 diabetics (T2DM: 50.1±12y, 7.5±1.8% HbA1c) absent of insulin therapy and nine similar aged (41.1±13.7y) healthy non-obese controls (HC: 33.4±7.8% fat mass, P<0.01; 5.3±0.4% HbA1c, P<0.01) participated. Using a randomized design, subjects underwent either a whole body passive hyperthermia treatment via head-out hot water immersion (1h resting in 39.4±0.4°C water) that increased internal temperature above baseline by ∆1.6±0.4°C or a control resting condition. Twenty-four hours post treatments, a 75g OGTT was administered to evaluate changes in plasma glucose, insulin, C-peptide, and leptin concentrations. Hyperthermia itself did not alter area under the curve for plasma glucose, insulin, or C-peptide during the OGTT in either group. Fasting absolute and normalized (kg·fat mass) plasma leptin was significantly increased (P<0.01) only after the hyperthermic exposure by 17% in T2DM and 24% in HC groups (P<0.001) when compared to the control condition. These data indicate that an acute hyperthermic treatment does not improve glucose tolerance 24h post treatment in moderate metabolic controlled obese T2DM or HC individuals. PMID:27264884

  5. Insulin Secretory Defect and Insulin Resistance in Isolated Impaired Fasting Glucose and Isolated Impaired Glucose Tolerance

    PubMed Central

    Aoyama-Sasabe, Sae; Fukushima, Mitsuo; Xin, Xin; Taniguchi, Ataru; Nakai, Yoshikatsu; Mitsui, Rie; Takahashi, Yoshitaka; Tsuji, Hideaki; Yabe, Daisuke; Yasuda, Koichiro; Kurose, Takeshi; Inagaki, Nobuya; Seino, Yutaka

    2016-01-01

    Objective. To investigate the characteristics of isolated impaired glucose tolerance (IGT) and isolated impaired fasting glucose (IFG), we analyzed the factors responsible for elevation of 2-hour postchallenge plasma glucose (2 h PG) and fasting plasma glucose (FPG) levels. Methods. We investigated the relationship between 2 h PG and FPG levels who underwent 75 g OGTT in 5620 Japanese subjects at initial examination for medical check-up. We compared clinical characteristics between isolated IGT and isolated IFG and analyzed the relationships of 2 h PG and FPG with clinical characteristics, the indices of insulin secretory capacity, and insulin sensitivity. Results. In a comparison between isolated IGT and isolated IFG, insulinogenic index was lower in isolated IGT than that of isolated IFG (0.43 ± 0.34 versus 0.50 ± 0.47, resp.; p < 0.01). ISI composite was lower in isolated IFG than that of isolated IGT (6.87 ± 3.38 versus 7.98 ± 4.03, resp.; p < 0.0001). In isolated IGT group, insulinogenic index showed a significant correlation with 2 h PG (r = −0.245, p < 0.0001) and had the strongest correlation with 2 h PG (β = −0.290). In isolated IFG group, ISI composite showed a significant correlation with FPG (r = −0.162, p < 0.0001) and had the strongest correlation with FPG (β = −0.214). Conclusions. We have elucidated that decreased early-phase insulin secretion is the most important factor responsible for elevation of 2 h PG levels in isolated IGT subjects, and decreased insulin sensitivity is the most important factor responsible for elevation of FPG levels in isolated IFG subjects. PMID:26788515

  6. Impaired glucose tolerance in pediatric burn patients at discharge from the acute hospital stay

    PubMed Central

    Fram, Ricki Y.; Cree, Melanie G.; Wolfe, Robert R.; Barr, David; Herndon, David N.

    2013-01-01

    Objective Hyperglycemia, secondary to the hypermetabolic stress response, is a common occurrence after thermal injury. This stress response has been documented to persist up to 9 months post burn. The purpose of this study was to measure insulin sensitivity in severely burned children prior to discharge when wounds are 95% healed. Methods Twenty-four children, aged 4–17 years, with burns ≥ 40% total body surface area (TBSA) underwent a 2 hour oral glucose tolerance test (OGTT) prior to discharge from the acute pediatric burn unit. Plasma glucose and insulin levels, as well as the Homeostasis Model Assessment for Insulin Resistance (HOMAIR) were compared to published OGTT data from healthy, non-burned children. Results There was a significant difference between severely burned children and non-burned, healthy children with respect to the HOMAIR. Severely burned children had a HOMAIR of 3.53±1.62 compared to the value in non-burned healthy children was 1.28±0.16 (p<0.05). Conclusion Insulin resistance secondary to the hypermetabolic stress response persists in severely burned children when burn wounds are at least 95% healed. The results of this study warrant future investigations into therapeutic options for the burned child during the rehabilitative phase of their care after injury. PMID:20634704

  7. Finger temperature controller for non-invasive blood glucose measurement

    NASA Astrophysics Data System (ADS)

    Zhang, Xiqin; Ting, Choon Meng; Yeo, Joon Hock

    2010-11-01

    Blood glucose level is an important parameter for doctors to diagnose and treat diabetes. The Near-Infra-Red (NIR) spectroscopy method is the most promising approach and this involves measurement on the body skin. However it is noted that the skin temperature does fluctuate with the environmental and physiological conditions and we found that temperature has important influences on the glucose measurement. In-vitro and in-vivo investigations on the temperature influence on blood glucose measurement have been carried out. The in-vitro results show that water temperature has significant influence on water absorption. Since 90% of blood components are water, skin temperature of measurement site has significant influence on blood glucose measurement. Also the skin temperature is related to the blood volume, blood volume inside capillary vessels changes with skin temperature. In this paper the relationship of skin temperature and signal from the skin and inside tissue was studied at different finger temperatures. Our OGTT (oral glucose tolerance test) trials results show the laser signals follow the skin temperature trend and the correlation of signal and skin temperature is much stronger than the correlation of signal and glucose concentration. A finger heater device is designed to heat and maintain the skin temperature of measurement site. The heater is controlled by an electronic circuit according to the skin temperature sensed by a thermocouple that is put close to the measurement site. In vivo trials were carried out and the results show that the skin temperature significantly influences the signal fluctuations caused by pulsate blood and the average signal value.

  8. Breed differences in insulin sensitivity and insulinemic responses to oral glucose in horses and ponies of moderate body condition score.

    PubMed

    Bamford, N J; Potter, S J; Harris, P A; Bailey, S R

    2014-04-01

    Breed-related differences may occur in the innate insulin sensitivity (SI) of horses and ponies, an important factor believed to be associated with the risk of laminitis. The aim of this study was to measure the glucose and insulin responses of different breeds of horses and ponies in moderate body condition to a glucose-containing meal and to compare these responses with the indices of SI as determined by a frequently sampled intravenous glucose tolerance test (FSIGT). Eight Standardbred horses, 8 mixed-breed ponies, and 7 Andalusian-cross horses with a mean ± SEM BCS 5.0 ± 0.3 of 9 were used in this study. Each animal underwent an oral glucose tolerance test (OGTT) in which they were fed a fiber-based ration (2.0 g/kg BW) containing 1.5 g/kg BW added glucose, as well as a standard FSIGT with minimal model analysis. The glucose response variables from the OGTT were similar between groups; however, the peak insulin concentration was higher in ponies (94.1 ± 29.1 μIU/mL; P = 0.003) and Andalusians (85.3 ± 18.6; P = 0.004) than in Standardbreds (21.2 ± 3.5). The insulin area under the curve was also higher in ponies (13.5 ± 3.6 IU · min · L(-1); P = 0.009) and Andalusians (15.0 ± 2.7; P = 0.004) than in Standardbreds (3.1 ± 0.6). Insulin sensitivity, as determined by the FSIGT, was lower in Andalusians (0.99 ± 0.18 × 10(-4)/[mIU · min]) than in Standardbreds (5.43 ± 0.94; P < 0.001) and in ponies (2.12 ± 0.44; P = 0.003) than in Standardbreds. Peak insulin concentrations from the OGTT were negatively correlated with SI (P < 0.001; rs = -0.75). These results indicate that there are clear breed-related differences in the insulin responses of horses and ponies to oral and intravenous glucose. All animals were in moderate body condition, indicating that breed-related differences in insulin dynamics occurred independent of obesity. PMID:24308928

  9. Beneficial effect of dietary Ephedra sinica on obesity and glucose intolerance in high-fat diet-fed mice.

    PubMed

    Song, Moon-Koo; Um, Jae-Young; Jang, Hyeung-Jin; Lee, Byung-Cheol

    2012-04-01

    Obesity is a major contributor to both glucose intolerance and metabolic syndrome. In this study, we investigated the anti-obesity and anti-hyperglycemic effects of Ephedra sinica on high-fat diet-fed mice. Male ICR mice were divided into four groups; the normal group, the obese and diabetic control group treated with a high-fat diet, the positive control group treated with a high-fat diet containing acarbose, and the experimental group treated with a high-fat diet containing Ephedra sinica. The effects of Ephedra sinica on obesity and glucose intolerance were measured by an oral glucose tolerance test (OGTT), plasma biochemistry, body and epididymal fat weight; the expression of adiponectin, peroxisome-proliferator-activated receptor α (PPAR-α), tumor necrosis factor α (TNF-α) and leptin was also determined. Ephedra sinica reduced weight gain and epididymal fat accumulation, improved glucose intolerance on the OGTT, decreased triglycerides and increased high-density lipoprotein cholesterol compared to the controls. Moreover, it reduced weight gain and fasting glucose levels and improved HDL-cholesterol levels more than acarbose. Gene expression analysis revealed that Ephedra sinica upregulated the expression of adiponectin and PPAR-α, and downregulated the expression of TNF-α. From these results, we suggest that Ephedra sinica may reduce obesity and hyperglycemia by increasing PPAR-α and adiponectin and reducing TNF-α, and that it may have the potential to be used clinically as an ingredient in food or drugs effective in obesity-related glucose intolerance treatments. PMID:22969956

  10. Synthesized Peptides from Yam Dioscorin Hydrolysis in Silico Exhibit Dipeptidyl Peptidase-IV Inhibitory Activities and Oral Glucose Tolerance Improvements in Normal Mice.

    PubMed

    Lin, Yin-Shiou; Han, Chuan-Hsiao; Lin, Shyr-Yi; Hou, Wen-Chi

    2016-08-24

    RRDY, RL, and DPF were the top 3 of 21 peptides for inhibitions against dipeptidyl peptidase-IV (DPP-IV) from the pepsin hydrolysis of yam dioscorin in silico and were further investigated in a proof-of-concept study in normal ICR mice for regulating glucose metabolism by the oral glucose tolerance test (OGTT). The sample or sitagliptin (positive control) was orally administered by a feeding gauge; 30 min later, the glucose loads (2.5 g/kg) were performed. RRDY, yam dioscorin, or sitagliptin preload, but not DPF, lowered the area under the curve (AUC0-120) of blood glucose and DPP-IV activity and elevated the AUC0-120 of blood insulin, which showed significant differences compared to control (P < 0.05 or 0.001). These results suggested that RRDY and yam dioscorin might be beneficial in glycemic control in normal mice and need further investigations in diabetic animal models. PMID:27499387

  11. Effect of the consumption of β-lactoglobulin and epigallocatechin-3-gallate with or without calcium on glucose tolerance in C57BL/6 mice.

    PubMed

    Carnovale, Valérie; Pilon, Geneviève; Britten, Michel; Bazinet, Laurent; Couillard, Charles

    2016-05-01

    Interactions between β-lactoglobulin (β-lg) and epigallocatechin-3-gallate (EGCG) may modulate their health benefits. The objective of this study was therefore to investigate the synergistic effect of consuming β-lg and EGCG complexes on glucose tolerance of C57BL/6 male mice given an oral glucose tolerance test (OGTT) and randomized to one of the following treatments administered prior to the OGTT: 1) simulated milk ultrafiltrate (SMUF(-)), 2) SMUF(-) + EGCG, 3) SMUF(-) + β-lg, 4) SMUF(-) + EGCG + β-lg, 5) SMUF + calcium (SMUF(+)) and 6) SMUF(+) + EGCG + β-lg. We found no significant between-group difference in postprandial glucose response. However, when mice were separated in those who received β-lg from those who did not, we found that the latter displayed significantly higher postprandial glucose concentrations. Our results support the beneficial impact of β-lg on glycemic control and suggest that concomitant EGCG or calcium consumption does not improve this effect. PMID:26960683

  12. Use of anesthesia dramatically alters the oral glucose tolerance and insulin secretion in C57Bl/6 mice.

    PubMed

    Windeløv, Johanne A; Pedersen, Jens; Holst, Jens J

    2016-06-01

    Evaluation of the impact of anesthesia on oral glucose tolerance in mice. Anesthesia is often used when performing OGTT in mice to avoid the stress of gavage and blood sampling, although anesthesia may influence gastrointestinal motility, blood glucose, and plasma insulin dynamics. C57Bl/6 mice were anesthetized using the following commonly used regimens: (1) hypnorm/midazolam repetitive or single injection; (2) ketamine/xylazine; (3) isoflurane; (4) pentobarbital; and (5) A saline injected, nonanesthetized group. Oral glucose was administered at time 0 min and blood glucose measured in the time frame -15 to +150 min. Plasma insulin concentration was measured at time 0 and 20 min. All four anesthetic regimens resulted in impaired glucose tolerance compared to saline/no anesthesia. (1) hypnorm/midazolam increased insulin concentrations and caused an altered glucose tolerance; (2) ketamine/xylazine lowered insulin responses and resulted in severe hyperglycemia throughout the experiment; (3) isoflurane did not only alter the insulin secretion but also resulted in severe hyperglycemia; (4) pentobarbital resulted in both increased insulin secretion and impaired glucose tolerance. All four anesthetic regimens altered the oral glucose tolerance, and we conclude that anesthesia should not be used when performing metabolic studies in mice. PMID:27255361

  13. Prospective validation of a 1-hour algorithm to rule-out and rule-in acute myocardial infarction using a high-sensitivity cardiac troponin T assay

    PubMed Central

    Reichlin, Tobias; Twerenbold, Raphael; Wildi, Karin; Gimenez, Maria Rubini; Bergsma, Nathalie; Haaf, Philip; Druey, Sophie; Puelacher, Christian; Moehring, Berit; Freese, Michael; Stelzig, Claudia; Krivoshei, Lian; Hillinger, Petra; Jäger, Cedric; Herrmann, Thomas; Kreutzinger, Philip; Radosavac, Milos; Weidmann, Zoraida Moreno; Pershyna, Kateryna; Honegger, Ursina; Wagener, Max; Vuillomenet, Thierry; Campodarve, Isabel; Bingisser, Roland; Miró, Òscar; Rentsch, Katharina; Bassetti, Stefano; Osswald, Stefan; Mueller, Christian

    2015-01-01

    Background: We aimed to prospectively validate a novel 1-hour algorithm using high-sensitivity cardiac troponin T measurement for early rule-out and rule-in of acute myocardial infarction (MI). Methods: In a multicentre study, we enrolled 1320 patients presenting to the emergency department with suspected acute MI. The high-sensitivity cardiac troponin T 1-hour algorithm, incorporating baseline values as well as absolute changes within the first hour, was validated against the final diagnosis. The final diagnosis was then adjudicated by 2 independent cardiologists using all available information, including coronary angiography, echocardiography, follow-up data and serial measurements of high-sensitivity cardiac troponin T levels. Results: Acute MI was the final diagnosis in 17.3% of patients. With application of the high-sensitivity cardiac troponin T 1-hour algorithm, 786 (59.5%) patients were classified as “rule-out,” 216 (16.4%) were classified as “rule-in” and 318 (24.1%) were classified to the “observational zone.” The sensitivity and the negative predictive value for acute MI in the rule-out zone were 99.6% (95% confidence interval [CI] 97.6%–99.9%) and 99.9% (95% CI 99.3%–100%), respectively. The specificity and the positive predictive value for acute MI in the rule-in zone were 95.7% (95% CI 94.3%–96.8%) and 78.2% (95% CI 72.1%–83.6%), respectively. The 1-hour algorithm provided higher negative and positive predictive values than the standard interpretation of highsensitivity cardiac troponin T using a single cut-off level (both p < 0.05). Cumulative 30-day mortality was 0.0%, 1.6% and 1.9% in patients classified in the rule-out, observational and rule-in groups, respectively (p = 0.001). Interpretation: This rapid strategy incorporating high-sensitivity cardiac troponin T baseline values and absolute changes within the first hour substantially accelerated the management of suspected acute MI by allowing safe rule-out as well as accurate

  14. Impact of Reduced Meal Frequency Without Caloric Restriction on Glucose Regulation in Healthy, Normal Weight Middle-Aged Men and Women

    PubMed Central

    Carlson, Olga; Martin, Bronwen; Stote, Kim S.; Golden, Erin; Maudsley, Stuart; Najjar, Samer S.; Ferrucci, Luigi; Ingram, Donald K.; Longo, Dan L.; Rumpler, William V.; Baer, David J.; Egan, Josephine; Mattson, Mark P.

    2007-01-01

    An unresolved issue in the field of diet and health is if and how changes in meal frequency affect energy metabolism in humans. We therefore evaluated the influence of reduced meal frequency without a reduction in energy intake on glucose metabolism in normal weight healthy male and female subjects. The study was a randomized cross-over design, with 2 eight-week treatment periods (with an intervening 11 week off-diet period) in which subjects consumed all of their calories for weight maintenance distributed in either 3 meals or 1 meal per day (consumed between 17:00 and 21:00). Energy metabolism was evaluated at designated time points throughout the study by performing morning oral glucose tolerance tests (OGTT) and measuring levels of glucose, insulin, glucagon, leptin, ghrelin, adiponectin, resistin and brain-derived neurotrophic factor (BDNF). Subjects consuming 1 meal/d exhibited higher morning fasting plasma glucose levels, greater and more sustained elevations of plasma glucose concentrations and a delayed insulin response in the OGTT compared to subjects consuming 3 meal/d. Levels of ghrelin were elevated in response to the 1 meal/d regimen. Fasting levels of insulin, leptin, ghrelin, adiponectin, resistin and BDNF were not significantly affected by meal frequency. Subjects consuming a single large daily meal exhibit elevated fasting glucose levels, and impaired morning glucose tolerance associated with a delayed insulin response, during a 2 month diet period compared to those consuming 3 meals/day. The impaired glucose tolerance was reversible and was not associated with alterations in the levels of adipokines or BDNF. PMID:17998028

  15. Dairy fat intake is associated with glucose tolerance, hepatic and systemic insulin sensitivity, and liver fat but not β-cell function in humans123

    PubMed Central

    Marcovina, Santica; Nelson, James E; Yeh, Matthew M; Kowdley, Kris V; Callahan, Holly S; Song, Xiaoling; Di, Chongzhi; Utzschneider, Kristina M

    2014-01-01

    Background: Plasma phospholipid concentrations of trans-palmitoleic acid (trans-16:1n−7), a biomarker of dairy fat intake, are inversely associated with incident type 2 diabetes in 2 US cohorts. Objective: The objective was to investigate whether the intake of trans-16:1n−7 in particular, or dairy fat in general, is associated with glucose tolerance and key factors determining glucose tolerance. Design: A cross-sectional investigation was undertaken in 17 men and women with nonalcoholic fatty liver disease and 15 body mass index (BMI)- and age-matched controls. The concentrations of trans-16:1n−7 and 2 other biomarkers of dairy fat intake, 15:0 and 17:0, were measured in plasma phospholipids and free fatty acids (FFAs). Liver fat was estimated by computed tomography–derived liver-spleen ratio. Intravenous-glucose-tolerance tests and oral-glucose-tolerance test (OGTT) and hyperinsulinemic-euglycemic clamps were performed to assess β-cell function and hepatic and systemic insulin sensitivity. Results: In multivariate analyses adjusted for age, sex, and BMI, phospholipid 17:0, phospholipid trans-16:1n−7, FFA 15:0, and FFA 17:0 were inversely associated with fasting plasma glucose, the area under the curve for glucose during an OGTT, and liver fat. Phospholipid trans-16:1n−7 was also positively associated with hepatic and systemic insulin sensitivity. None of the biomarkers were associated with β-cell function. The associations between dairy fat intake and glucose tolerance were attenuated by adjusting for insulin sensitivity or liver fat, but strengthened by adjusting for β-cell function. Conclusion: Although we cannot rule out reverse causation, these data support the hypothesis that dairy fat improves glucose tolerance, possibly through a mechanism involving improved hepatic and systemic insulin sensitivity and reduced liver fat. This trial was registered at clinicaltrials.gov as NCT01289639. PMID:24740208

  16. Cigarette Smoking Is Associated with a Lower Prevalence of Newly Diagnosed Diabetes Screened by OGTT than Non-Smoking in Chinese Men with Normal Weight

    PubMed Central

    Chen, Peizhu; Lu, Jun; Ma, Xiaojing; Lu, Juming; Weng, Jianping; Ji, Linong; Shan, Zhongyan; Liu, Jie; Tian, Haoming; Ji, Qiuhe; Zhu, Dalong; Ge, Jiapu; Lin, Lixiang; Chen, Li; Guo, Xiaohui; Zhao, Zhigang; Li, Qiang; Zhou, Zhiguang; Yang, Wenying; Jia, Weiping

    2016-01-01

    Different studies have produced conflicting results regarding the association between smoking and diabetes mellitus, and detailed analysis of this issue in Chinese males based on nationwide samples is lacking. We explored the association between cigarette smoking and newly-diagnosed diabetes mellitus (NDM) in Chinese males using a population-based case-control analysis; 16,286 male participants without previously diagnosed diabetes were included. Prediabetes and NDM were diagnosed using the oral glucose tolerance test. The cohort included 6,913 non-smokers (42.4%), 1,479 ex-smokers (9.1%) and 7,894 current smokers (48.5%). Age-adjusted glucose concentrations (mmol/L) were significantly lower at fasting and 120 min in current smokers than non-smokers (5.25 vs. 5.30, 6.46 vs. 6.55, respectively, both P < 0.01). After adjustment for demographic and behavioral variables (age, region, alcohol consumption status, physical activity, education, and family history of diabetes), logistic regression revealed significant negative associations between smoking and NDM in males of a normal weight (BMI < 25 kg/m2: adjusted odds ratio [AOR] = 0.75, P = 0.007; waist circumference < 90 cm: AOR = 0.71, P = 0.001) and males living in southern China (AOR = 0.75, P = 0.009), but not in males who were overweight/obese, males with central obesity, or males living in northern China. Compared to non-smokers, current smokers were less likely to be centrally obese or have elevated BP (AOR: 0.82 and 0.74, both P < 0.05), and heavy smokers (≥ 20 pack-years) were less likely to have elevated TG (AOR = 0.84, P = 0.012) among males of a normal weight. There were no significant associations between quitting smoking and metabolic disorders either among males of a normal weight or males who were overweight/obese. In conclusion, smokers have a lower likelihood of NDM than non-smokers among Chinese males with a lower BMI/smaller waist. PMID:26954355

  17. Noninvasive blood glucose measurement using multiple laser diodes

    NASA Astrophysics Data System (ADS)

    Ooi, E. T.; Zhang, X. Q.; Chen, J. H.; Soh, P. H.; Ng, K.; Yeo, J. H.

    2007-02-01

    In the event of diabetes clinicians have advocated that frequent monitoring of a diabetic's blood glucose level is the key to avoid future complications (kidney failure, blindness, amputations, premature death, etc.,) associated with the disease. While the test-strip glucose meters available in current consumer markets allow for frequent monitoring, a more convenient technique that is accurate, painless and sample-free is preferable in a diabetic's daily routine. This paper presents a non-invasive blood glucose measurement technique using diffuse reflectance near infrared (NIR) signals. This technique uses a set of laser diodes, each operating at fixed wavelengths in the first overtone region. The NIR signals from the laser diodes are channeled to the measurement site viz., the nail-bed by means of optical fibers. A series of in vivo experiments have been performed on eight normal human subjects using a standard Oral Glucose Tolerance Test (OGTT) protocol. The reflected NIR signals are inputs to a Partial Least Squares (PLS) algorithm for calibration and future predictions. The calibration models used are developed using in vivo datasets and are unique to a particular individual. The 1218 paired points collected from the eight test subjects plotted on the Clarke Error Grid, revealed that 87.3% of these points fall within the A zone while the remainder, within the B zone, both of which, are clinically accepted. The standard error of prediction was +/-13.14mg/dL for the best calibration model. A Bland-Altman analysis of the 1218 paired points yields a 76.3% confidence level for a measurement accuracy of +/-20mg/dL. These results demonstrate the initial potential of the technique for non-invasive blood glucose measurements in vivo.

  18. Study on optical measurement conditions for noninvasive blood glucose sensing

    NASA Astrophysics Data System (ADS)

    Xu, Kexin; Chen, Wenliang; Jiang, Jingying; Qiu, Qingjun

    2004-05-01

    Utilizing Near-infrared Spectroscopy for non-invasive glucose concentration sensing has been a focusing topic in biomedical optics applications. In this paper study on measuring conditions of spectroscopy on human body is carried out and a series of experiments on glucose concentration sensing are conducted. First, Monte Carlo method is applied to simulate and calculate photons" penetration depth within skin tissues at 1600 nm. The simulation results indicate that applying our designed optical probe, the detected photons can penetrate epidermis of the palm and meet the glucose sensing requirements within the dermis. Second, we analyze the influence of the measured position variations and the contact pressure between the optical fiber probe and the measured position on the measured spectrum during spectroscopic measurement of a human body. And, a measurement conditions reproduction system is introduced to enhance the measurement repeatability. Furthermore, through a series of transmittance experiments on glucose aqueous solutions sensing from simple to complex we found that though some absorption variation information of glucose can be obtained from measurements using NIR spectroscopy, while under the same measuring conditions and with the same modeling method, choices toward measured components reduce when complication degree of components increases, and this causes a decreased prediction accuracy. Finally, OGTT experiments were performed, and a PLS (Partial Least Square) mathematical model for a single experiment was built. We can easily get a prediction expressed as RMSEP (Root Mean Square Error of Prediction) with a value of 0.5-0.8mmol/dl. But the model"s extended application and reliability need more investigation.

  19. Glucose test (image)

    MedlinePlus

    ... person with diabetes constantly manages their blood's sugar (glucose) levels. After a blood sample is taken and tested, it is determined whether the glucose levels are low or high. If glucose levels ...

  20. Low Blood Glucose (Hypoglycemia)

    MedlinePlus

    ... Other Dental Problems Diabetic Eye Disease Low Blood Glucose (Hypoglycemia) What is hypoglycemia? Hypoglycemia, also called low ... actions can also help prevent hypoglycemia: Check blood glucose levels Knowing your blood glucose level can help ...

  1. [Neonatal diarrhea due to congenital glucose-galactose malabsorption: report of seven cases].

    PubMed

    Chedane-Girault, C; Dabadie, A; Maurage, C; Piloquet, H; Chailloux, E; Colin, E; Pelatan, C; Giniès, J-L

    2012-12-01

    Congenital glucose-galactose malabsorption (CGGM) is a rare autosomal recessive disorder, which presents as a protracted diarrhea in early neonatal life. We describe the clinical history, diagnostic evaluation, and management of 7 children with CGGM in western France. There were 4 girls and 3 boys from 5 families, born between 1984 and 2010. The principal complaint was a neonatal onset of watery and acidic severe diarrhea complicated by hypertonic dehydration. The diarrhea stopped with fasting. In 2 cases, the family history supported the diagnosis. In the other cases, elimination of glucose and galactose (lactose) from the diet resulted in the complete resolution of diarrhea symptoms. In 2 cases, the H2 breath tests were positive. In 2 cases, the HGPO or oral glucose tolerance test (OGTT) demonstrated an abnormal curve with glucose and a normal curve with fructose. DNA sequencing was not used. When glucose and galactose were eliminated from the diet, the infants had normal growth and development. In conclusion, CGGM is a rare etiology of neonatal diarrhea; however, the diagnosis is easy to make and the prognosis is excellent. PMID:23107089

  2. Personalized Metabolomics for Predicting Glucose Tolerance Changes in Sedentary Women After High-Intensity Interval Training

    PubMed Central

    Kuehnbaum, Naomi L.; Gillen, Jenna B.; Gibala, Martin J.; Britz-McKibbin, Philip

    2014-01-01

    High-intensity interval training (HIIT) offers a practical approach for enhancing cardiorespiratory fitness, however its role in improving glucose regulation among sedentary yet normoglycemic women remains unclear. Herein, multi-segment injection capillary electrophoresis-mass spectrometry is used as a high-throughput platform in metabolomics to assess dynamic responses of overweight/obese women (BMI > 25, n = 11) to standardized oral glucose tolerance tests (OGTTs) performed before and after a 6-week HIIT intervention. Various statistical methods were used to classify plasma metabolic signatures associated with post-prandial glucose and/or training status when using a repeated measures/cross-over study design. Branched-chain/aromatic amino acids and other intermediates of urea cycle and carnitine metabolism decreased over time in plasma after oral glucose loading. Adaptive exercise-induced changes to plasma thiol redox and orthinine status were measured for trained subjects while at rest in a fasting state. A multi-linear regression model was developed to predict changes in glucose tolerance based on a panel of plasma metabolites measured for naïve subjects in their untrained state. Since treatment outcomes to physical activity are variable between-subjects, prognostic markers offer a novel approach to screen for potential negative responders while designing lifestyle modifications that maximize the salutary benefits of exercise for diabetes prevention on an individual level. PMID:25164777

  3. Evaluation of Fasting State-/Oral Glucose Tolerance Test-Derived Measures of Insulin Release for the Detection of Genetically Impaired β-Cell Function

    PubMed Central

    Heni, Martin; Ketterer, Caroline; Guthoff, Martina; Kantartzis, Konstantinos; Machicao, Fausto; Stefan, Norbert; Häring, Hans-Ulrich; Fritsche, Andreas

    2010-01-01

    Background To date, fasting state- and different oral glucose tolerance test (OGTT)-derived measures are used to estimate insulin release with reasonable effort in large human cohorts required, e.g., for genetic studies. Here, we evaluated twelve common (or recently introduced) fasting state-/OGTT-derived indices for their suitability to detect genetically determined β-cell dysfunction. Methodology/Principal Findings A cohort of 1364 White European individuals at increased risk for type 2 diabetes was characterized by OGTT with glucose, insulin, and C-peptide measurements and genotyped for single nucleotide polymorphisms (SNPs) known to affect glucose- and incretin-stimulated insulin secretion. One fasting state- and eleven OGTT-derived indices were calculated and statistically evaluated. After adjustment for confounding variables, all tested SNPs were significantly associated with at least two insulin secretion measures (p≤0.05). The indices were ranked according to their associations' statistical power, and the ranks an index obtained for its associations with all the tested SNPs (or a subset) were summed up resulting in a final ranking. This approach revealed area under the curve (AUC)Insulin(0-30)/AUCGlucose(0-30) as the best-ranked index to detect SNP-dependent differences in insulin release. Moreover, AUCInsulin(0-30)/AUCGlucose(0-30), corrected insulin response (CIR), AUCC-Peptide(0-30)/AUCGlucose(0-30), AUCC-Peptide(0-120)/AUCGlucose(0-120), two different formulas for the incremental insulin response from 0–30 min, i.e., the insulinogenic indices (IGI)2 and IGI1, and insulin 30 min were significantly higher-ranked than homeostasis model assessment of β-cell function (HOMA-B; p<0.05). AUCC-Peptide(0-120)/AUCGlucose(0-120) was best-ranked for the detection of SNPs involved in incretin-stimulated insulin secretion. In all analyses, HOMA-β displayed the highest rank sums and, thus, scored last. Conclusions/Significance With AUCInsulin(0-30)/AUCGlucose(0

  4. Blood Test: Glucose

    MedlinePlus

    ... Things to Know About Zika & Pregnancy Blood Test: Glucose KidsHealth > For Parents > Blood Test: Glucose Print A A A Text Size What's in ... de sangre: glucosa What It Is A blood glucose test measures the amount of glucose (the main ...

  5. The performance of hemoglobin A1c against fasting plasma glucose and oral glucose tolerance test in detecting prediabetes and diabetes

    PubMed Central

    Karakaya, Jale; Akin, Safak; Karagaoglu, Ergun; Gurlek, Alper

    2014-01-01

    Background: In recent years, hemoglobin A1c (HbA1c) is accepted among the algorithms used for making diagnosis for diabetes and prediabetes since it does not require subjects to be prepared for giving a blood sample. The aim of this study is to assess the performance of HbA1c against fasting plasma glucose (FPG) and oral glucose tolerance test (OGTT) in detecting prediabetes and diabetes. Materials and Methods: A total of 315 subjects were included in this study. The success of HbA1c in distinguishing the three diagnostic classes was examined by three-way receiver operating characteristic (ROC) analysis. The best cut-off points for HbA1c were found for discriminating the three disease status. Results: The performance of HbA1c, measured by the volume under the ROC surface (VUS), is found to be statistically significant (VUS = 0.535, P < 0.001). The best cut-off points for discriminating between normal and prediabetes groups and between prediabetes and diabetes groups are c1 = 5.2% and c2 = 6.4% respectively. Conclusion: The performance of HbA1c in distinguishing between the prediabetes and diabetes groups was higher than its ability in distinguishing between healthy and prediabetes groups. This study provides enough information to understand what proportion of diabetes patients were skipped with the HbA1c especially when the test result is healthy or prediabetes. If a subject was diagnosed as healthy or prediabetes by HbA1c, it would be beneficial to verify the status of that subject by the gold standard test (OGTT and FPG). PMID:25657750

  6. Mandatory oral glucose tolerance tests identify more diabetics in stable patients with chronic heart failure: a prospective observational study

    PubMed Central

    2014-01-01

    Background Many patients with chronic heart failure (CHF) are believed to have unrecognized diabetes, which is associated with a worse prognosis. This study aimed to describe glucose tolerance in a general stable CHF population and to identify determinants of glucose tolerance focusing on body composition and skeletal muscle strength. Methods A prospective observational study was set up. Inclusion criteria were diagnosis of CHF, stable condition and absence of glucose-lowering medication. Patients underwent a 2 h oral glucose tolerance test (OGTT), isometric strength testing of the upper leg and dual energy x-ray absorptiometry. Health-related quality of life and physical activity level were assessed by questionnaire. Results Data of 56 participants were analyzed. Despite near-normal fasting glucose values, 55% was classified as prediabetic, 14% as diabetic, and 20% as normal glucose tolerant. Of all newly diagnosed diabetic patients, 79% were diagnosed because of 2 h glucose values only and none because of HbA1c. Univariate mixed model analysis revealed ischaemic aetiology, daily physical activity, E/E’, fat trunk/fat limbs and extension strength as possible explanatory variables for the glucose curve during the glucose tolerance test. When combined in one model, only fat trunk/fat limbs and E/E’ remained significant predictors. Furthermore, fasting insulin was correlated with fat mass/height2 (r = 0.51, p < 0.0001), extension strength (r = -0.33, p < 0.01) and triglycerides (r = 0.39, p < 0.01). Conclusions Our data confirm that a large majority of CHF patients have impaired glucose tolerance. This glucose intolerance is related to fat distribution and left ventricular end-diastolic pressure. PMID:24673860

  7. Knockdown of neuropeptide Y in the dorsomedial hypothalamus reverses high-fat diet-induced obesity and impaired glucose tolerance in rats.

    PubMed

    Kim, Yonwook J; Bi, Sheng

    2016-01-15

    Neuropeptide Y (NPY) in the dorsomedial hypothalamus (DMH) plays an important role in the regulation of energy balance. While DMH NPY overexpression causes hyperphagia and obesity in rats, knockdown of NPY in the DMH via adeno-associated virus (AAV)-mediated RNAi (AAVshNPY) ameliorates these alterations. Whether this knockdown has a therapeutic effect on obesity and glycemic disorder has yet to be determined. The present study sought to test this potential using a rat model of high-fat diet (HFD)-induced obesity and insulin resistance, mimicking human obesity with impaired glucose homeostasis. Rats had ad libitum access to rodent regular chow (RC) or HFD. Six weeks later, an oral glucose tolerance test (OGTT) was performed for verifying HFD-induced glucose intolerance. After verification, obese rats received bilateral DMH injections of AAVshNPY or the control vector AAVshCTL, and OGTT and insulin tolerance test (ITT) were performed at 16 and 18 wk after viral injection (23 and 25 wk on HFD), respectively. Rats were killed at 26 wk on HFD. We found that AAVshCTL rats on HFD remained hyperphagic, obese, glucose intolerant, and insulin resistant relative to lean control RC-fed rats receiving DMH injection of AAVshCTL, whereas these alterations were reversed in NPY knockdown rats fed a HFD. NPY knockdown rats exhibited normal food intake, body weight, glucose tolerance, and insulin sensitivity, as seen in lean control rats. Together, these results demonstrate a therapeutic action of DMH NPY knockdown against obesity and impaired glucose homeostasis in rats, providing a potential target for the treatment of obesity and diabetes. PMID:26561644

  8. Diabetes alters the blood glucose response to ketamine in streptozotocin-diabetic rats

    PubMed Central

    Chen, Huayong; Li, Li; Xia, Hui

    2015-01-01

    Ketamine is a commonly used short-acting anesthetic and recently attempted to treat pain which is a complication of diabetes. In this study we investigated the effect of ketamine on glucose levels of normal rats and diabetic rats. The results showed that no significance between the glucose levels in ketamine treatment group and saline treatment group at all time points was observed in normal rats. Ketamine did not produce hyperglycemia in normal fasted rats. However, ketamine dose dependently elevated glucose in diabetic rats from 80 mg/kg to 120 mg/kg at 1 hour after injection. The glucose did not return to the levels before treatment in streptozotocin (STZ) induced diabetic rats. Insulin revealed a powerful potency in decreasing glucose levels in diabetic rats. Ketamine did not induce acute hyperglycemia any more after diabetic rats pretreated with insulin. Serum corticosterone was significantly increased in all treatment groups including saline group after 1 hour treatment compared with baseline values. Then the corticosterone declined in both saline treatment groups. However, ketamine induced a more significant increase in corticosterone at 1 hour after injection compared with that of saline control group of diabetic rats. And no decline trend of corticosterone was observed after ketamine treatment 2 hours. Insulin did not reduce the elevated corticosterone level induced by ketamine either. The results suggested that the diabetic rats had a risk of hyperglycaemia when they were treated with ketamine. Pretreatment with insulin is a good symptomatic treatment for hyperglycaemia induced by ketamine. PMID:26379948

  9. Diabetes alters the blood glucose response to ketamine in streptozotocin-diabetic rats.

    PubMed

    Chen, Huayong; Li, Li; Xia, Hui

    2015-01-01

    Ketamine is a commonly used short-acting anesthetic and recently attempted to treat pain which is a complication of diabetes. In this study we investigated the effect of ketamine on glucose levels of normal rats and diabetic rats. The results showed that no significance between the glucose levels in ketamine treatment group and saline treatment group at all time points was observed in normal rats. Ketamine did not produce hyperglycemia in normal fasted rats. However, ketamine dose dependently elevated glucose in diabetic rats from 80 mg/kg to 120 mg/kg at 1 hour after injection. The glucose did not return to the levels before treatment in streptozotocin (STZ) induced diabetic rats. Insulin revealed a powerful potency in decreasing glucose levels in diabetic rats. Ketamine did not induce acute hyperglycemia any more after diabetic rats pretreated with insulin. Serum corticosterone was significantly increased in all treatment groups including saline group after 1 hour treatment compared with baseline values. Then the corticosterone declined in both saline treatment groups. However, ketamine induced a more significant increase in corticosterone at 1 hour after injection compared with that of saline control group of diabetic rats. And no decline trend of corticosterone was observed after ketamine treatment 2 hours. Insulin did not reduce the elevated corticosterone level induced by ketamine either. The results suggested that the diabetic rats had a risk of hyperglycaemia when they were treated with ketamine. Pretreatment with insulin is a good symptomatic treatment for hyperglycaemia induced by ketamine. PMID:26379948

  10. Effects of sugar-sweetened beverage intake on the development of type 2 diabetes mellitus in subjects with impaired glucose tolerance: the Mihama diabetes prevention study.

    PubMed

    Teshima, Nobuko; Shimo, Miho; Miyazawa, Kae; Konegawa, Sachi; Matsumoto, Aki; Onishi, Yuki; Sasaki, Ryoma; Suzuki, Toshinari; Yano, Yutaka; Matsumoto, Kazutaka; Yamada, Tomomi; Gabazza, Esteban Cesar; Takei, Yoshiyuki; Sumida, Yasuhiro

    2015-01-01

    In Japan, the incidence of type 2 diabetes mellitus (T2DM) is increasing for several reasons, including increased consumption of sugar-sweetened beverages (SSBs). However, whether SSBs cause T2DM by excess of energy production resulting in obesity remains unclear. Therefore, the present study was designed to evaluate the effects of SSB intake on the development of T2DM in subjects with impaired glucose tolerance (IGT). Ninety-three subjects (30 males and 63 females) with IGT aged 40-69 y and residing in the Mihama district (southern Mie Prefecture, Japan) were included in the study. The mean observational period was 3.6 y. All subjects underwent the 75-g oral glucose tolerance test (OGTT) and completed a lifestyle questionnaire survey related to SSB intake. OGTT results and SSB intake were evaluated before and after the observational period. In addition, the correlation between SSB intake and development of T2DM was investigated. Of the 93 subjects, 20 (21.5%) developed T2DM (T2DM group) and demonstrated a significantly high SSB intake compared with the group that did not develop the disease (non-T2DM group). The odds ratio for the incidence of T2DM based on SSB intake was 3.26 (95% confidence interval, 1.17-9.06). The body mass index (BMI; kg/m(2)) and the homeostasis model assessment for insulin resistance (HOMA-R) values was significantly higher in the T2DM group than in the non-T2DM group, while the insulinogenic indices were significantly lower in the former than in the latter group. The sum of insulin secretion levels during OGTT was not significantly different between groups. SSB intake correlated with the predisposition for developing T2DM, possibly by influencing body weight, insulin resistance, and the ability of the pancreatic beta cells to effectively compensate for the insulin resistance. PMID:25994135

  11. Glucose-6-phosphate dehydrogenase

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003671.htm Glucose-6-phosphate dehydrogenase test To use the sharing features on this page, please enable JavaScript. Glucose-6-phosphate dehydrogenase (G6PD) is a type of ...

  12. Your Glucose Meter

    MedlinePlus

    ... by Audience For Women Women's Health Topics Your Glucose Meter Share Tweet Linkedin Pin it More sharing ... Español Basic Facts 7 Tips for Testing Your Blood Sugar and Caring for Your Meter Glucose meters test ...

  13. Continuous Glucose Monitoring

    MedlinePlus

    ... catalog. Additional Links ​ Alternative Devices for Taking Insulin Children and Diabetes Glucose Meters Juvenile Diabetes (Teens and Diabetes ) Know Your Blood Glucose Numbers Your Guide to Diabetes: Type 1 and Type 2 Contact Us Health Information Center ...

  14. Decrease in the plasma von Willebrand factor concentration following glucose ingestion: the role of insulin sensitivity.

    PubMed

    von Känel, R; Nelesen, R A; Le, D T; Ziegler, M G; Dimsdale, J E

    2001-12-01

    Elevated plasma von Willebrand factor (vWF) concentration is thought to be associated with increased prevalence of cardiovascular events in the insulin resistance syndrome. We examined the effects of oral glucose challenge and accompanying metabolic and hemodynamic changes on vWF levels with respect to insulin sensitivity. Forty normotensive and hypertensive subjects (mean age +/- SD, 40 +/- 5 years) underwent a standard oral glucose tolerance test (OGTT). Plasma vWF antigen, glucose, insulin, catecholamines, and hemodynamics were measured at rest, and at 30, 60, 90, and 120 minutes after glucose intake. Insulin sensitivity was determined by the insulin sensitivity index (ISI(0,120)). Resting plasma vWF concentration was associated with screening systolic blood pressure (BP) (r =.43, P =.005). There were time effects for all variables of interest. While vWF antigen (P =.044), epinephrine (P =.003), and diastolic BP (P =.001) decreased after glucose challenge, norepinephrine (P =.009), systolic BP (P =.022), and heart rate (P <.001) increased. Decline in vWF (area under the curve) was associated with decrease in epinephrine (r =.46, P =.004) and with screening systolic BP (r =.45, P =.004). However, neither resting plasma vWF levels nor vWF decrease following glucose ingestion were significantly associated with the ISI(0,120.) The plasma vWF concentration decreases following glucose ingestion. While mechanisms underlying this phenomenon may relate to sympathetic nervous system function, they seem not related to insulin sensitivity. Endothelial dysfunction such as caused by hypertension rather than metabolic dysregulation per se may underlie the elevated plasma vWF concentration found with insulin resistance. PMID:11735092

  15. Effects of xylitol on carbohydrate digesting enzymes activity, intestinal glucose absorption and muscle glucose uptake: a multi-mode study.

    PubMed

    Chukwuma, Chika Ifeanyi; Islam, Md Shahidul

    2015-03-01

    The present study investigated the possible mechanism(s) behind the effects of xylitol on carbohydrate digesting enzymes activity, muscle glucose uptake and intestinal glucose absorption using in vitro, ex vivo and in vivo experimental models. The effects of increasing concentrations of xylitol (2.5%-40% or 164.31 mM-2628.99 mM) on alpha amylase and alpha glucosidase activity in vitro and intestinal glucose absorption and muscle glucose uptake were investigated under ex vivo conditions. Additionally, the effects of an oral bolus dose of xylitol (1 g per kg BW) on gastric emptying and intestinal glucose absorption and digesta transit in the different segments of the intestinal tract were investigated in normal and type 2 diabetic rats at 1 hour after dose administration, when phenol red was used as a recovery marker. Xylitol exhibited concentration-dependent inhibition of alpha amylase (IC₅₀ = 1364.04 mM) and alpha glucosidase (IC₅₀ = 1127.52 mM) activity in vitro and small intestinal glucose absorption under ex vivo condition. Xylitol also increased dose dependent muscle glucose uptake with and without insulin, although the uptake was not significantly affected by the addition of insulin. Oral single bolus dose of xylitol significantly delayed gastric emptying, inhibited intestinal glucose absorption but increased the intestinal digesta transit rate in both normal and diabetic rats compared to their respective controls. The data of this study suggest that xylitol reduces intestinal glucose absorption via inhibiting major carbohydrate digesting enzymes, slowing gastric emptying and fastening the intestinal transit rate, but increases muscle glucose uptake in normal and type 2 diabetic rats. PMID:25656339

  16. CSF glucose test

    MedlinePlus

    Glucose test - CSF; Cerebrospinal fluid glucose test ... The glucose level in the CSF should be 50 to 80 mg/100 mL (or greater than 2/3 of the blood sugar level). Note: Normal value ranges may vary slightly ...

  17. A physiology-based model describing heterogeneity in glucose metabolism: the core of the Eindhoven Diabetes Education Simulator (E-DES).

    PubMed

    Maas, Anne H; Rozendaal, Yvonne J W; van Pul, Carola; Hilbers, Peter A J; Cottaar, Ward J; Haak, Harm R; van Riel, Natal A W

    2015-03-01

    Current diabetes education methods are costly, time-consuming, and do not actively engage the patient. Here, we describe the development and verification of the physiological model for healthy subjects that forms the basis of the Eindhoven Diabetes Education Simulator (E-DES). E-DES shall provide diabetes patients with an individualized virtual practice environment incorporating the main factors that influence glycemic control: food, exercise, and medication. The physiological model consists of 4 compartments for which the inflow and outflow of glucose and insulin are calculated using 6 nonlinear coupled differential equations and 14 parameters. These parameters are estimated on 12 sets of oral glucose tolerance test (OGTT) data (226 healthy subjects) obtained from literature. The resulting parameter set is verified on 8 separate literature OGTT data sets (229 subjects). The model is considered verified if 95% of the glucose data points lie within an acceptance range of ±20% of the corresponding model value. All glucose data points of the verification data sets lie within the predefined acceptance range. Physiological processes represented in the model include insulin resistance and β-cell function. Adjusting the corresponding parameters allows to describe heterogeneity in the data and shows the capabilities of this model for individualization. We have verified the physiological model of the E-DES for healthy subjects. Heterogeneity of the data has successfully been modeled by adjusting the 4 parameters describing insulin resistance and β-cell function. Our model will form the basis of a simulator providing individualized education on glucose control. PMID:25526760

  18. Prehepatic secretion and disposal of insulin in obese adolescents as estimated by three-hour, eight-sample oral glucose tolerance tests.

    PubMed

    Vogt, Josef A; Domzig, Christian; Wabitsch, Martin; Denzer, Christian

    2016-07-01

    The body compensates for early-stage insulin resistance by increasing insulin secretion. A reliable and easy-to-use mathematical assessment of insulin secretion and disposal could be a valuable tool for identifying patients at risk for the development of type 2 diabetes. Because the pathophysiology of insulin resistance is incompletely understood, assessing insulin metabolism with minimal assumptions regarding its metabolic regulation is a major challenge. To assess insulin secretion and indexes of insulin disposal, our marginalized and regularized absorption approach (MRA) was applied to a sparse sampling oral glucose tolerance test (OGTT) protocol measuring the insulin and C-peptide concentrations. Identifiability and potential bias of metabolic parameters were estimated from published data with dense sampling. The MRA was applied to OGTT data from 135 obese adolescents to demonstrate its clinical applicability. Individual prehepatic basal and dynamic insulin secretion and clearance levels were determined with a precision and accuracy greater than 10% of the nominal value. The intersubject variability in these parameters was approximately four times higher than the intrasubject variability, and there was a strong negative correlation between prehepatic secretion and plasma clearance of insulin. MRA-based analysis provides reliable estimates of insulin secretion and clearance, thereby enabling detailed glucose homeostasis characterization based on restricted datasets that are obtainable during routine patient care. PMID:27143555

  19. To Assess the Association between Glucose Metabolism and Ectopic Lipid Content in Different Clinical Classifications of PCOS

    PubMed Central

    Göbl, Christian S.; Ott, Johannes; Bozkurt, Latife; Feichtinger, Michael; Rehmann, Victoria; Cserjan, Anna; Heinisch, Maike; Steinbrecher, Helmut; JustKukurova, Ivica; Tuskova, Radka; Leutner, Michael; Vytiska-Binstorfer, Elisabeth; Kurz, Christine; Weghofer, Andrea; Tura, Andrea; Egarter, Christian; Kautzky-Willer, Alexandra

    2016-01-01

    Aims There are emerging data indicating an association between PCOS (polycystic ovary syndrome) and metabolic derangements with potential impact on its clinical presentation. This study aims to evaluate the pathophysiological processes beyond PCOS with particular focus on carbohydrate metabolism, ectopic lipids and their possible interaction. Differences between the two established classifications of the disease should be additionally evaluated. Methods A metabolic characterization was performed in 53 untreated PCOS patients as well as 20 controls including an extended oral glucose tolerance test (OGTT, to assess insulin sensitivity, secretion and ß-cell function) in addition to a detailed examination of ectopic lipid content in muscle and liver by nuclear magnetic resonance spectroscopy. Results Women with PCOS classified by the original NIH 1990 definition showed a more adverse metabolic risk profile compared to women characterized by the additional Rotterdam 2003 phenotypes. Subtle metabolic derangements were observed in both subgroups, including altered shapes of OGTT curves, impaired insulin action and hyperinsulinemia due to increased secretion and attenuated hepatic extraction. No differences were observed for ectopic lipids between the groups. However, particularly hepatocellular lipid content was significantly related to clinical parameters of PCOS like whole body insulin sensitivity, dyslipidemia and free androgen index. Conclusions Subtle alterations in carbohydrate metabolism are present in both PCOS classifications, but more profound in subjects meeting the NIH 1990 criteria. Females with PCOS and controls did not differ in ectopic lipids, however, liver fat was tightly related to hyperandrogenism and an adverse metabolic risk profile. PMID:27505055

  20. Effects of stevioside on glucose transport activity in insulin-sensitive and insulin-resistant rat skeletal muscle.

    PubMed

    Lailerd, Narissara; Saengsirisuwan, Vitoon; Sloniger, Julie A; Toskulkao, Chaivat; Henriksen, Erik J

    2004-01-01

    Stevioside (SVS), a natural sweetener extracted from Stevia rebaudiana, has been used as an antihyperglycemic agent. However, little is known regarding its potential action on skeletal muscle, the major site of glucose disposal. Therefore, the purpose of the present study was to determine the effect of SVS treatment on skeletal muscle glucose transport activity in both insulin-sensitive lean (Fa/-) and insulin-resistant obese (fa/fa) Zucker rats. SVS was administered (500 mg/kg body weight by gavage) 2 hours before an oral glucose tolerance test (OGTT). Whereas the glucose incremental area under the curve (IAUC(glucose)) was not affected by SVS in lean Zucker rats, the insulin incremental area under the curve (IAUC(insulin)) and the glucose-insulin index (product of glucose and insulin IAUCs and inversely related to whole-body insulin sensitivity) were decreased (P<.05) by 42% and 45%, respectively. Interestingly, in the obese Zucker rat, SVS also reduced the IAUC(insulin) by 44%, and significantly decreased the IAUC(glucose) (30%) and the glucose-insulin index (57%). Muscle glucose transport was assessed following in vitro SVS treatment. In lean Zucker rats, basal glucose transport in type I soleus and type IIb epitrochlearis muscles was not altered by 0.01 to 0.1 mmol/L SVS. In contrast, 0.1 mmol/L SVS enhanced insulin-stimulated (2 mU/mL) glucose transport in both epitrochlearis (15%) and soleus (48%). At 0.5 mmol/L or higher, the SVS effect was reversed. Similarly, basal glucose transport in soleus and epitrochlearis muscles in obese Zucker rats was not changed by lower doses of SVS (0.01 to 0.1 mmol/L). However, these lower doses of SVS significantly increased insulin-stimulated glucose transport in both obese epitrochlearis and soleus (15% to 20%). In conclusion, acute oral SVS increased whole-body insulin sensitivity, and low concentrations of SVS (0.01 to 0.1 mmol/L) modestly improved in vitro insulin action on skeletal muscle glucose transport in both lean

  1. Polymorphism rs11085226 in the Gene Encoding Polypyrimidine Tract-Binding Protein 1 Negatively Affects Glucose-Stimulated Insulin Secretion

    PubMed Central

    Heni, Martin; Ketterer, Caroline; Wagner, Robert; Linder, Katarzyna; Böhm, Anja; Herzberg-Schäfer, Silke A.; Machicao, Fausto; Knoch, Klaus-Peter; Fritsche, Andreas; Staiger, Harald; Häring, Hans-Ulrich; Solimena, Michele

    2012-01-01

    Objective Polypyrimidine tract-binding protein 1 (PTBP1) promotes stability and translation of mRNAs coding for insulin secretion granule proteins and thereby plays a role in β-cells function. We studied whether common genetic variations within the PTBP1 locus influence insulin secretion, and/or proinsulin conversion. Methods We genotyped 1,502 healthy German subjects for four tagging single nucleotide polymorphisms (SNPs) within the PTBP1 locus (rs351974, rs11085226, rs736926, and rs123698) covering 100% of genetic variation with an r2≥0.8. The subjects were metabolically characterized by an oral glucose tolerance test with insulin, proinsulin, and C-peptide measurements. A subgroup of 320 subjects also underwent an IVGTT. Results PTBP1 SNP rs11085226 was nominally associated with lower insulinogenic index and lower cleared insulin response in the OGTT (p≤0.04). The other tested SNPs did not show any association with the analyzed OGTT-derived secretion parameters. In the IVGTT subgroup, SNP rs11085226 was accordingly associated with lower insulin levels within the first ten minutes following glucose injection (p = 0.0103). Furthermore, SNP rs351974 was associated with insulin levels in the IVGTT (p = 0.0108). Upon interrogation of MAGIC HOMA-B data, our rs11085226 result was replicated (MAGIC p = 0.018), but the rs351974 was not. Conclusions We conclude that common genetic variation in PTBP1 influences glucose-stimulated insulin secretion. This underlines the importance of PTBP1 for beta cell function in vivo. PMID:23077502

  2. Effects of Whey Proteins on Glucose Metabolism in Normal Wistar Rats and Zucker Diabetic Fatty (ZDF) Rats

    PubMed Central

    Gregersen, Soren; Bystrup, Sara; Overgaard, Ann; Jeppesen, Per B.; Sonderstgaard Thorup, Anne C.; Jensen, Erik; Hermansen, Kjeld

    2013-01-01

    BACKGROUND: Beneficial effects of milk protein on glucose metabolism have been reported. OBJECTIVES: We hypothesized that dietary supplementation with specific milk protein fractions could prevent diabetes and differentially alter tissue gene expression. Therefore, we studied the effects of supplementing the diet with whey isolate, whey hydrolysate, Α-lactalbumin, and casein proteins in Zucker Diabetic Fatty rats (ZDF) and normal Wistar rats. A chow diet was included as well. METHODS: Six week old male ZDF (n = 60) and Wistar rats (n = 44) were used in a 13 week study. P-glucose, p-insulin, p-glucagon, HbA1c, total-cholesterol, HDL-cholesterol, and triglycerides were measured. An oral glucose tolerance test (OGTT) was performed. Liver, muscle, and adipose samples were used for RT-PCR. One-way ANOVA and multiple comparison tests were performed. RESULTS: HbA1c increased during intervention, and was significantly lower for all milk protein fractions compared to chow in the ZDF rats (p < 0.05). At week 18, iAUCs during OGTT in the ZDF rats were similar for all milk protein-treated groups and significantly lower than in the chow fed group (p < 0.01). In the chow-fed group of ZDF rats, p-glucagon increased significantly compared to all milk protein fed animals. Total and HDL cholesterol were increased in the milk protein-treated ZDF rats compared with the control group. Expression of liver GYS2 and SREBP-2 were downregulated in the milk protein-fed ZDF groups compared with chow. CONCLUSIONS: We conclude that milk protein fractions improve glycemic indices in diabetic rats. No major differences were seen between the milk protein fractions. However, the fractions had a differential impact on tissue gene expression, most pronounced in ZDF rats. PMID:24841879

  3. [Glucose Metabolism: Stress Hyperglycemia and Glucose Control].

    PubMed

    Tanaka, Katsuya; Tsutsumi, Yasuo M

    2016-05-01

    It is important for the anesthesiologists to understand pathophysiology of perioperative stress hyperglycemia, because it offers strategies for treatment of stress hyperglycemia. The effect of glucose tolerance is different in the choice of the anesthetic agent used in daily clinical setting. Specifically, the volatile anesthetics inhibit insulin secretion after glucose load and affects glucose tolerance. During minor surgery by the remifentanil anesthesia, the stress reaction is hard to be induced, suggesting that we should consider low-dose glucose load. Finally it is necessary to perform the glycemic control of the patients who fell into stress hyperglycemia depending on the individual patient. However, there are a lot of questions to be answered in the future. The prognosis of the perioperative patients is more likely to be greatly improved if we can control stress hyperglycemia. PMID:27319094

  4. Impaired peripheral glucose sensing in F1 offspring of diabetic pregnancy.

    PubMed

    Kamel, Maher A; Helmy, Madiha H; Hanafi, Mervat Y; Mahmoud, Shimaa A; Abo Elfetooh, Hanan

    2014-09-01

    Maternal diabetes can induce permanent changes in glucose homeostasis that can occur pre- and post-natal and leads to type 2 diabetes in adulthood. This study aimed to investigate the effect of maternal diabetes on the F1 offspring peripheral glucose sensing and mitochondrial biogenesis in an attempt to clarify the mechanism of diabetogenic programming. Two groups of female Wistar rats were used (diabetic and control); diabetes was neonatally induced by STZ injection to 5-day old rats. After the pregnancy and delivery, the offspring were weaned to control diet or high-caloric (HCD) diet and followed up for 30 weeks. Every 5 weeks, OGTT was constructed, and serum and tissues were obtained for the assessment of mTFA, mtDNA, UCP2, insulin receptor (IR), phospho-insulin receptor (phospho-IR), and GLUT4. The result indicated impaired glucose tolerance (IGT) and insulin resistance in the offspring under control diet at the 15th week of age and thereafter while those offspring under HCD showed IGT at 10th week, and diabetes was evidenced at the 25th week of age. This defect in glucose metabolism was preceded by impairment in the phosphorylation of IR and decreased IR and Glut4 that cause impaired glucose sensing together with inhibited mitochondrial biogenesis in muscle and adipose tissues. This study indicated that maternal diabetes caused impaired glucose sensing and insulin resistance in the peripheral tissues and caused change in the expression of genes involved in mitochondrial biogenesis and function. Post-natal feeding with HCD may accelerate these changes. Male F1 offspring appears to be more sensitive than females for fetal programming of T2D. PMID:24895245

  5. Retrospective study on the efficacy of a low-carbohydrate diet for impaired glucose tolerance

    PubMed Central

    Maekawa, Satoshi; Kawahara, Tetsuya; Nomura, Ryosuke; Murase, Takayuki; Ann, Yasuyoshi; Oeholm, Masayuki; Harada, Masaru

    2014-01-01

    Background In recent years, the number of people with impaired glucose tolerance (IGT) has increased steadily worldwide. It is clear that the prevention of diabetes is important from the perspective of public health, medical care, and economics. It was recently reported that a low-carbohydrate diet (LCD) is useful for achieving weight loss and glycemic control, but there is no information about the effects of the LCD on IGT. We designed a 7-day in-hospital educational program focused on the LCD for IGT. Methods The subjects were 72 patients with IGT (36 in the LCD group and 36 in the control group) who were enrolled from April 2007–March 2012 and followed for 12 months. We retrospectively compared the LCD group with the control group. Results In 69.4% of the LCD group, blood glucose was normalized at 12 months and the 2-hour plasma glucose level in the oral glucose tolerance test (OGTT) was reduced by 33 mg/dL. In addition, the incidence of diabetes was significantly lower in the LCD group than in the control group at 12 months (0% versus 13.9%, P=0.02). The LCD group showed a significant decrease in fasting plasma glucose, hemoglobin A1c, the homeostasis model of assessment of insulin resistance value, body weight and serum triglycerides (TGs) at 12 months, while there was a significant increase of the serum high-density lipoprotein (HDL) cholesterol level. Conclusion The LCD is effective for normalizing blood glucose and preventing progression to type 2 diabetes in patients with IGT. PMID:24966689

  6. Evaluation of the effects of 80% methanolic leaf extract of Caylusea abyssinica (fresen.) fisch. & Mey. on glucose handling in normal, glucose loaded and diabetic rodents

    PubMed Central

    2012-01-01

    Background The leaves of Caylusea abyssinica (fresen.) Fisch. & Mey. (Resedaceae), a plant widely distributed in East African countries, have been used for management of diabetes mellitus in Ethiopian folklore medicine. However, its use has not been scientifically validated. The present study was undertaken to investigate antidiabetic effects of the hydroalcoholic leaf extract of C. abyssinica extract in rodents. Materials and method Male Animals were randomly divided into five groups for each diabetic, normoglycemic and oral glucose tolerance test (OGTT) studies. Group 1 served as controls and administered 2% Tween-80 in distilled water, (TW80); Group 2 received 5 mg/kg glibenclamide (GL5); Groups 3, 4 and 5 were given 100 (CA100), 200 (CA200) and 300 (CA300) mg/kg, respectively, of the hydroalcoholic extract of C. abyssinica. Blood samples were then collected at different time points to determine blood glucose levels (BGL). Data were analyzed using one way ANOVA followed by Dunnet’s post hoc test and p < 0.05was considered as statistically significant. Results In normal mice, CA200 and GL5 induced hypoglycemia starting from the 2nd h but the hypoglycemic effect of CA300 was delayed and appeared at the 4th h (p < 0.05 in all cases). In diabetic mice, BGL was significantly reduced by CA100 (p < 0.05) and CA300 (p < 0.01) starting from the 3rd h, whereas CA200 (p < 0.001) and GL5 (p < 0.05) attained this effect as early as the 2nd h. In OGTT, TW80 (p < 0.01) and CA100 (p < 0.01) brought down BGL significantly at 120 min, while CA200 (p < 0.001) and GL5 (p < 0.001) achieved this effect at 60 min indicating the oral glucose load improving activity of the extract. By contrast, CA300 was observed to have no effect on OGTT. Acute toxicity study revealed the safety of the extract even at a dose of 2000 mg/kg. Preliminary phytochemical study demonstrated the presence of various secondary metabolites, including, among others

  7. Placental DNA methylation of peroxisome-proliferator-activated receptor-γ co-activator-1α promoter is associated with maternal gestational glucose level.

    PubMed

    Xie, Xuemei; Gao, Hongjie; Zeng, Wanjiang; Chen, Suhua; Feng, Ling; Deng, Dongrui; Qiao, Fu-yuan; Liao, Lihong; McCormick, Kenneth; Ning, Qin; Luo, Xiaoping

    2015-08-01

    Intrauterine exposure to hyperglycaemia may increase the risk of later-life metabolic disorders. Although the underlying mechanism is not fully understood, epigenetic dysregulation in fetal programming has been implicated. With regard to energy homoeostasis, PGC-1α (peroxisome-proliferator-activated receptor γ co-activator-1α, encoded by the PPARGC1A gene) plays a regulatory role in several biochemical processes. We hypothesized that maternal gestational glucose levels would positively correlate with DNA methylation of the PPARGC1A promoter in placental tissue. We undertook a cross-sectional study of 58 mothers who underwent uncomplicated Caesarean delivery in a university hospital. Maternal gestational glucose concentration was determined after a 75-g OGTT (oral glucose tolerance test) at 24-28 weeks of gestation. Placenta tissue and cord blood were collected immediately after delivery. Genomic DNA was extracted and thereafter bisulfite conversion was performed. After PCR amplification, the DNA methylation of the PPARGC1A promoter was quantified using a pyrosequencing technique. The protein level of PGC-1α was evaluated by Western blotting. For all participants as a whole, including the GDM (gestational diabetes mellitus) and normoglycaemia groups, the maternal gestational glucose level was positively correlated with placental DNA methylation, and negatively correlated with cord blood DNA methylation of the PPARGC1A promoter in a CpG site-specific manner. In the GDM group alone, the placental CpG site-specific methylation of the PPARGC1A promoter strongly correlated with gestational 2-h post-OGTT glycaemia. Epigenetic alteration of the PPAGRC1A promoter may be one of the potential mechanisms underlying the metabolic programming in offspring exposed to intrauterine hyperglycaemia. PMID:25875376

  8. Glucose: detection and analysis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Glucose is an aldosic monosaccharide that is centrally entrenched in the processes of photosynthesis and respiration, serving as an energy reserve and metabolic fuel in most organisms. As both a monomer and as part of more complex structures such as polysaccharides and glucosides, glucose also pla...

  9. Monitor blood glucose - slideshow

    MedlinePlus

    ... medlineplus.gov/ency/presentations/100220.htm Monitoring blood glucose - Series—Monitoring blood glucose: Using a self-test meter To use the ... A.M. Editorial team. Related MedlinePlus Health Topics Blood Sugar A.D.A.M., Inc. is accredited by ...

  10. Glucose monitoring during Ramadan.

    PubMed

    Jabbar, Abdul

    2015-05-01

    In patients with diabetes who intend to fast during Ramadan, self-monitoring of blood glucose (SMBG) is an important tool. During this month, a long established treatment regimen, including medications, physical activity and diet plan, is changed to achieve concordance with the rules of fasting. Without proper glucose monitoring, it is not possible to achieve good glycaemic control. PMID:26013788

  11. Poor sleep quality is associated with impaired glucose tolerance in women after gestational diabetes.

    PubMed

    Ferrari, U; Künzel, H; Tröndle, K; Rottenkolber, M; Kohn, D; Fugmann, M; Banning, F; Weise, M; Sacco, V; Hasbargen, U; Hutter, S; Parhofer, K G; Kloiber, S; Ising, M; Seissler, J; Lechner, A

    2015-06-01

    We analyzed the association of sleep quality and glucose metabolism in women after gestational diabetes (pGDM) and in women after normoglycemic pregnancy (controls). Data during pregnancy and a visit within the first 15 months after delivery were collected from 61 pGDM and 30 controls in a prospective cohort study. This included a medical history, physical examination, questionnaires (Pittsburgh Sleep Quality Index (PSQI), and Perceived Stress Scale (PSS)), and 5-point oral glucose tolerance test with insulin measurements to determine indices of insulin sensitivity and insulin secretion. We used Spearman correlation coefficients and multivariate regression models for analysis.9.3 ± 3.2 months after delivery, pGDM had significantly higher fasting and 2 h glucose levels and lower insulin sensitivity than controls. There was no significant difference in age, BMI and sleep quality as assessed with the PSQI between the two groups. The PSQI score correlated with the ogtt-2 h plasma glucose in pGDM (δ = 0.41; p = 0.0012), but not in controls. This association was confirmed with a multivariate linear regression model with adjustment for age, BMI and months post-delivery. Perceived stress was an independent risk factor (OR 1.12; 95% CI 1.02-1.23) for impaired sleep. Our findings suggest that post-delivery sleep quality significantly influences glucose tolerance in women after GDM and that impaired sleep is associated with increased stress perception. Measures to improve of sleep quality and reduce perceived stress should therefore be tested as additional strategies to prevent progression to type 2 diabetes after GDM. PMID:25930074

  12. Novel coumarin modified GLP-1 derivatives with enhanced plasma stability and prolonged in vivo glucose-lowering ability

    PubMed Central

    Han, Jing; Sun, Lidan; Huang, Xun; Li, Zheng; Zhang, Chenyu; Qian, Hai; Huang, Wenlong

    2014-01-01

    Background and Purpose The short biological half-life limits the therapeutic use of glucagon-like peptide-1 (GLP-1) and chemical modification to improve the interaction of peptides with serum albumin represents an effective strategy to develop long-acting peptide analogues. Coumarin, a natural product, is known to bind tightly to plasma proteins and possesses many biological activities. Therefore, we designed and synthesized a series of coumarin-modified GLP-1 derivatives, hypothesizing that conjugation with coumarin would retain the therapeutic effects and prolong the biological half-life of the conjugates. Experimental Approach Four cysteine-modified GLP-1 analogues (1–4) were prepared using Gly8-GLP-1(7–36)-NH2 peptide as a starting point. These analogues were conjugated with two coumarin maleimides to yield eight compounds (conjugates 6–13) for testing. Activation of human GLP-1 receptors, stability to enzymic inactivation in plasma and binding to human albumin were assessed in vitro. In vivo, effects on oral glucose tolerance tests (OGTT) in rats and on blood glucose levels in db/db mice were studied. Key Results Most conjugates showed well preserved receptor activation efficacy, enhanced albumin-binding properties and improved in vitro plasma stability and conjugate 7 was selected to undergo further assessment. In rats, conjugate 7 had a longer circulating t1/2 than exendin-4 or liraglutide. A prolonged antidiabetic effect of conjugate 7 was observed after OGTT in rats and a prolonged hypoglycaemic effect in db/db mice. Conclusions and Implications Cysteine-specific coumarin conjugation with GLP-1 offers a useful approach to the development of long-acting incretin-based antidiabetic agents. Conjugate 7 is a promising long-lasting GLP-1 derivative deserving further investigation. PMID:25039358

  13. The minor C-allele of rs2014355 in ACADS is associated with reduced insulin release following an oral glucose load

    PubMed Central

    2011-01-01

    Background A genome-wide association study (GWAS) using metabolite concentrations as proxies for enzymatic activity, suggested that two variants: rs2014355 in the gene encoding short-chain acyl-coenzyme A dehydrogenase (ACADS) and rs11161510 in the gene encoding medium-chain acyl-coenzyme A dehydrogenase (ACADM) impair fatty acid β-oxidation. Chronic exposure to fatty acids due to an impaired β-oxidation may down-regulate the glucose-stimulated insulin release and result in an increased risk of type 2 diabetes (T2D). We aimed to investigate whether the two variants associate with altered insulin release following an oral glucose load or with T2D. Methods The variants were genotyped using KASPar® PCR SNP genotyping system and investigated for associations with estimates of insulin release and insulin sensitivity following an oral glucose tolerance test (OGTT) in a random sample of middle-aged Danish individuals (n ACADS = 4,324; n ACADM = 4,337). The T2D-case-control study involved a total of ~8,300 Danish individuals (n ACADS = 8,313; n ACADM = 8,344). Results In glucose-tolerant individuals the minor C-allele of rs2014355 of ACADS associated with reduced measures of serum insulin at 30 min following an oral glucose load (per allele effect (β) = -3.8% (-6.3%;-1.3%), P = 0.003), reduced incremental area under the insulin curve (β = -3.6% (-6.3%;-0.9%), P = 0.009), reduced acute insulin response (β = -2.2% (-4.2%;0.2%), P = 0.03), and with increased insulin sensitivity ISIMatsuda (β = 2.9% (0.5%;5.2%), P = 0.02). The C-allele did not associate with two other measures of insulin sensitivity or with a derived disposition index. The C-allele was not associated with T2D in the case-control analysis (OR 1.07, 95% CI 0.96-1.18, P = 0.21). rs11161510 of ACADM did not associate with any indices of glucose-stimulated insulin release or with T2D. Conclusions In glucose-tolerant individuals the minor C-allele of rs2014355 of ACADS was associated with reduced measures of

  14. Effects of different periods of paradoxical sleep deprivation and sleep recovery on lipid and glucose metabolism and appetite hormones in rats.

    PubMed

    Brianza-Padilla, Malinalli; Bonilla-Jaime, Herlinda; Almanza-Pérez, Julio César; López-López, Ana Laura; Sánchez-Muñoz, Fausto; Vázquez-Palacios, Gonzalo

    2016-03-01

    Sleep has a fundamental role in the regulation of energy balance, and it is an essential and natural process whose precise impacts on health and disease have not yet been fully elucidated. The aim of this study was to assess the consequences of different periods of paradoxical sleep deprivation (PSD) and recovery from PSD on lipid profile, oral glucose tolerance test (OGTT) results, and changes in insulin, corticosterone, ghrelin, and leptin concentrations. Three-month-old male Wistar rats weighing 250-350 g were submitted to 24, 96, or 192 h of PSD or 192 h of PSD with 480 h of recovery. The PSD was induced by the multiple platforms method. Subsequently, the animals were submitted to an OGTT. One day later, the animals were killed and the levels of triglycerides, total cholesterol, lipoproteins (low-density lipoprotein, very-low-density lipoprotein, and high-density lipoprotein), insulin, ghrelin, leptin, and corticosterone in plasma were quantified. There was a progressive decrease in body weight with increasing duration of PSD. The PSD induced basal hypoglycemia over all time periods evaluated. Evaluation of areas under the curve revealed progressive hypoglycemia only after 96 and 192 h of PSD. There was an increase in corticosterone levels after 192 h of PSD. We conclude that PSD induces alterations in metabolism that are reversed after a recovery period of 20 days. PMID:26842666

  15. Protein quality and quantity and insulin control of mammary gland glucose utilization during lactation

    SciTech Connect

    Masor, M.L.

    1987-01-01

    Virgin Sprague-Dawley rats were bred, and fed laboratory stock (STOCK), 13% casein plus methionine, 13% wheat gluten, or 5% casein plus methionine through gestation and 4 days of lactation. Diets were switched at parturition to determine the effects of dietary protein quality and quantity fed during gestation and/or lactation on insulin stimulation of mammary glucose utilization. On day 20 of gestation (20G) and day 4 of lactation (4L) the right inguinal-abdominal mammary glands were removed, and acini and tissue slices were incubated in Krebs buffer with or without insulin containing (U-/sup 14/C)-glucose and 5mM glucose for 1 hour at 37/degrees/C. Glucose incorporation into CO/sub 2/, lipid and lactose was determined. Glucose incorporation into CO/sub 2/ and lipid, but not lactose was stimulated by insulin in mammary slices. Diet effects on glucose utilization in acini were confirmed in slices for basal and insulin stimulated levels. Treatment affected the absolute increase of insulin stimulation. Regression analysis significantly correlated pup weight gain with total glucose utilization. Poor dietary protein quality and quantity fed during gestation impaired both overall response of mammary glucose utilization to insulin stimulation, and mammary development during pregnancy. Improving protein value at parturition did not overcome those deficits by 4L.

  16. Vascular Glucose Sensor Symposium

    PubMed Central

    Joseph, Jeffrey I; Torjman, Marc C.; Strasma, Paul J.

    2015-01-01

    Hyperglycemia, hypoglycemia, and glycemic variability have been associated with increased morbidity, mortality, length of stay, and cost in a variety of critical care and non–critical care patient populations in the hospital. The results from prospective randomized clinical trials designed to determine the risks and benefits of intensive insulin therapy and tight glycemic control have been confusing; and at times conflicting. The limitations of point-of-care blood glucose (BG) monitoring in the hospital highlight the great clinical need for an automated real-time continuous glucose monitoring system (CGMS) that can accurately measure the concentration of glucose every few minutes. Automation and standardization of the glucose measurement process have the potential to significantly improve BG control, clinical outcome, safety and cost. PMID:26078254

  17. Recombinant glucose uptake system

    DOEpatents

    Ingrahm, Lonnie O.; Snoep, Jacob L.; Arfman, Nico

    1997-01-01

    Recombinant organisms are disclosed that contain a pathway for glucose uptake other than the pathway normally utilized by the host cell. In particular, the host cell is one in which glucose transport into the cell normally is coupled to PEP production. This host cell is transformed so that it uses an alternative pathway for glucose transport that is not coupled to PEP production. In a preferred embodiment, the host cell is a bacterium other than Z. mobilis that has been transformed to contain the glf and glk genes of Z. mobilis. By uncoupling glucose transport into the cell from PEP utilization, more PEP is produced for synthesis of products of commercial importance from a given quantity of biomass supplied to the host cells.

  18. All about Blood Glucose

    MedlinePlus

    ... Blood Glucose Before meals: 80 to 130 mg/dl My Usual Results My Goals ______ to ______ ______ to ______ 2 ... the start of a meal: below 180 mg/dl below ______ below ______ What’s the best way to keep ...

  19. Blood Glucose Monitoring Devices

    MedlinePlus

    ... Glucose NIH Medline Plus - Diabetes Spotlight FDA permits marketing of first system of mobile medical apps for ... feeds Follow FDA on Twitter Follow FDA on Facebook View FDA videos on YouTube View FDA photos ...

  20. Effects of Averrhoa bilimbi leaf extract on blood glucose and lipids in streptozotocin-diabetic rats.

    PubMed

    Pushparaj, P; Tan, C H; Tan, B K

    2000-09-01

    The present study was designed to investigate the hypoglycemic and hypolipidemic activities of an ethanolic extract of Averrhoa bilimbi Linn. leaves (Oxalidaceae, Common name: Bilimbi) in streptozotocin (STZ)-diabetic rats. The optimal hypoglycemic dose (125 mg kg(-1)) was determined by performing the oral glucose tolerance test (OGTT) in both normal and STZ-diabetic rats. To investigate the effect of repeated administration of an ethanolic extract of Averrhoa bilimbi (ABe) leaves, diabetic rats were treated with vehicle (distilled water), ABe (125 mg kg(-1)) or metformin (500 mg kg(-1)) twice a day for 2 weeks. Like metformin, ABe significantly lowered blood glucose by 50% and blood triglyceride by 130% when compared with the vehicle. ABe also significantly increased the HDL-cholesterol concentrations by 60% compared with the vehicle. ABe thus significantly increased the anti-atherogenic index and HDL-cholesterol/total cholesterol ratio. However, like metformin, ABe did not affect total cholesterol and LDL-cholesterol concentrations, but significantly reduced the kidney lipid peroxidation level. These data show that ABe has hypoglycemic, hypotriglyceridemic, anti-lipid peroxidative and anti-atherogenic properties in STZ-diabetic rats. PMID:10967456

  1. Pre-exercise glucose ingestion at different time periods and blood glucose concentration during exercise.

    PubMed

    Tokmakidis, S P; Volaklis, K A

    2000-08-01

    The purpose of this study was to investigate the effects of glucose ingestion (GI) at different time periods prior to exercise on blood glucose (BG) levels during prolonged treadmill running. Eight subjects (X+/-SD), age 20+/-0.5yr, bodymass 70.7+/-4.1 kg, height 177+/-4 cm, VO2max 52.8+/-7.8 ml x kg(-1) x min(-1) who underwent different experimental conditions ingested a glucose solution (1 g/kg at 350 ml) 30 min (gl-30), 60 min (gl-60), 90 min (gl-90), and a placebo one 60 min (pl-60) prior to exercise in a counterbalanced design. Afterwards they ran at 65% of VO2max for 1 hour and then at 75 % of VO2max till exhaustion. Fingertip blood samples (10 microl) were drawn every 15 min before and during exercise for the determination of BG levels. Oxygen uptake (VO2), heart rate (HR), and blood lactate (La) were also measured every 15 min during exercise. Peak BG values were reached within 30 min after GI but were different (p < 0.01) at the onset of exercise (gl-30: 147+/-22, gl-60: 118+/-25, gl-90: 109+/-22, pl-60: 79+/-5mg/dl). The two-way ANOVA repeated measures and the Tukey post-hoc test revealed a higher BG concentration (p < 0.05) for the gl-30 and the pl-60 as compared to the gl-60 and gl-90 during running (e.g. 15min run: 82+/-11, 68+/-5, 64+/-3, 78+/-7, and 60min run: 98+/-12, 85+/-12, 83+/-11, 94+/-11 mg/dl for gl-30, gl-60, gl-90, and pl-60, respectively). However, this did not significantly affect the duration of treadmill running. The La levels were higher (p < 0.05) after GI as compared to placebo throughout exercise (values at exhaustion: 4.6+/-0.2, 5.0+/-1.5, 4.8+/- 1.7 mmol/l for gl-30, gl-60, gl-90, and 3.5+/-0.8 mmol/l for placebo). The gl-30 and the placebo fluctuated closer to normoglycaemic levels. The glucose ingestion (60 to 90 min) prior to exercise lowered the blood glucose levels without affecting the duration of running performance at 75% VO2max. Thus, in order to maintain normoglycaemic levels, pre-exercise glucose supplementation should

  2. Effect of acute hyperglycemia on potassium (86Rb+) permeability and plasma lipid peroxidation in subjects with normal glucose tolerance.

    PubMed

    Güven, M; Onaran, I; Ulutin, T; Sultuybek, G; Hatemi, H

    2001-04-01

    Hyperglycemia is likely to be one of the important determinants of ion transport as it is known to induce oxidative stress and may thus enhance non-specific permeability of membranes. The aim of the present study was to evaluate the effects of an acute increase in glycemia on 86Rb+ (a marker for K+) influx and lipid peroxidation. We evaluated the 75-g oral glucose tolerance test (OGTT)-induced modification on 86Rb+ influx and plasma lipid peroxidation in 20 subjects with normal glucose tolerance (NGT). After 2-hour glucose loading, the levels of passive 86Rb+ influx and plasma lipid peroxidation were significantly increased, whereas the active influx of 86Rb+ was unchanged. The total and passive influx of 86Rb+ into erythrocytes was significantly correlated with the level of plasma lipid peroxidation. This study demonstrates that acute hyperglycemia induces an increase in the passive influx of 86Rb+ in subjects with NGT, suggesting that acute hyperglycemia may produce an oxidative stress in plasma. These changes may be among the earliest changes occurring in response to hyperglycemia. PMID:11383909

  3. Effect of acute hyperglycemia on potassium (86Rb+) permeability and plasma lipid peroxidation in subjects with normal glucose tolerance.

    PubMed

    Güven, M; Onaran, I; Ulutin, T; Sultuybek, G; Hatemi, H

    2001-01-01

    Hyperglycemia is likely to be one of the important determinants of ion transport as it is known to induce oxidative stress and may thus enhance non-specific permeability of membranes. The aim of the present study was to evaluate the effects of an acute increase in glycemia on 86Rb+ (a marker for K+) influx and lipid peroxidation. We evaluated the 75-g oral glucose tolerance test (OGTT)-induced modification on 86Rb+ influx and plasma lipid peroxidation in 20 subjects with normal glucose tolerance (NGT). After 2-hour glucose loading, the levels of passive 86Rb+ influx and plasma lipid peroxidation were significantly increased, whereas the active influx of 86Rb+ was unchanged. The total and passive influx of 86Rb+ into erythrocytes was significantly correlated with the level of plasma lipid peroxidation. This study demonstrates that acute hyperglycemia induces an increase in the passive influx of 86Rb+ in subjects with NGT, suggesting that acute hyperglycemia may produce an oxidative stress in plasma. These changes may be among the earliest changes occurring in response to hyperglycemia. PMID:11508792

  4. Glucose homoeostasis following injury.

    PubMed Central

    Wright, P. D.

    1979-01-01

    Metabolic changes following injury have been observed for many years, and John Hunter discussed such changes in 1794. Changes in carbohydrate metabolism have been observed for a similar length of time, and glycosuria and hyperglycaemia have been reported by a number of observers. This paper records and quantitates the extent of hyperglycaemia in patients undergoing surgery of different degrees of severity and relates them to changes in blood insulin, growth hormone, cortisol, and catecholamine concentrations. Further animal studies were performed which suggested that a fall in intracellular glucose utilisation may be a contributory factor. The use of isotope labelling of glucose in man has enabled further studies to be done to clarify changes in exchangeable glucose mass, replacement rate, and space both in the normal situation and in the presence of infusions of glucagon, noradrenaline, glucose, and amino-acids. The hyperglycaemia is clearly the result of a complex interaction of changes in the availability and activity of hormones which control glucose metabolism both within and outside the cell. PMID:496234

  5. Impact of Vitamin D Replacement on Markers of Glucose Metabolism and Cardio-Metabolic Risk in Women with Former Gestational Diabetes--A Double-Blind, Randomized Controlled Trial.

    PubMed

    Yeow, Toh Peng; Lim, Shueh Lin; Hor, Chee Peng; Khir, Amir S; Wan Mohamud, Wan Nazaimoon; Pacini, Giovanni

    2015-01-01

    Gestational Diabetes Mellitus (GDM) and vitamin D deficiency are related to insulin resistance and impaired beta cell function, with heightened risk for future development of diabetes. We evaluated the impact of vitamin D supplementation on markers of glucose metabolism and cardio metabolic risk in Asian women with former GDM and hypovitaminosis D. In this double blind, randomized controlled trial, 26 participants were randomized to receive either daily 4000 IU vitamin D3 or placebo capsules. 75 g Oral Glucose Tolerance Test (OGTT) and biochemistry profiles were performed at baseline and 6 month visits. Mathematical models, using serial glucose, insulin and C peptide measurements from OGTT, were employed to calculate insulin sensitivity and beta cell function. Thirty three (76%) women with former GDM screened had vitamin D level of <50 nmol/L at baseline. Supplementation, when compared with placebo, resulted in increased vitamin D level (+51.1 nmol/L vs 0.2 nmol/L, p<0.001) and increased fasting insulin (+20% vs 18%, p = 0.034). The vitamin D group also demonstrated a 30% improvement in disposition index and an absolute 0.2% (2 mmol/mol) reduction in HbA1c. There was no clear change in insulin sensitivity or markers of cardio metabolic risk. This study highlighted high prevalence of vitamin D deficiency among Asian women with former GDM. Six months supplementation with 4000 IU of vitamin D3 safely restored the vitamin D level, improved basal pancreatic beta-cell function and ameliorated the metabolic state. There was no effect on markers of cardio metabolic risk. Further mechanistic studies exploring the role of vitamin D supplementation on glucose homeostasis among different ethnicities may be needed to better inform future recommendations for these women with former GDM at high risk of both hypovitaminosis D and future diabetes. PMID:26057782

  6. How to monitor blood glucose.

    PubMed

    Dunning, Trisha

    2016-01-27

    Rationale and key points Capillary blood glucose monitoring is an essential component of diabetes care. Blood glucose tests provide important information about how the body is controlling blood glucose metabolism, and the effect of glucose-lowering medicines, illness and stress. ▶ The nurse should consider the rationale for testing blood glucose each time they perform a test, and reflect on the result, taking into consideration the patient's blood glucose target range and recommended care guidelines. ▶ Blood glucose testing times and testing frequency should be planned to suit the glucose-lowering medicine regimen and the clinical situation. Reflective activity Clinical skills articles can help update your practice and ensure it remains evidence based. Apply this article to your practice. Reflect on and write a short account of: 1. What you have gained from this article. 2. How this article will influence your practice when monitoring blood glucose. Subscribers can upload their reflective accounts at: rcni.com/portfolio . PMID:26967884

  7. Castration-induced testosterone deficiency increases fasting glucose associated with hepatic and extra-hepatic insulin resistance in adult male rats

    PubMed Central

    2013-01-01

    Background Testosterone deficiency is associated with insulin resistance. However, how testosterone deficiency affects insulin actions remains unclear. The aim of this study was to investigate the influence of castration-induced testosterone deficiency on the metabolic kinetics of glucose and to evaluate the hepatic and extra-hepatic insulin sensitivity, in advanced-age male Sprague–Dawley (SD) rats. Methods Ten-week-old male SD rats were randomly divided into three groups: (1) a control group (n = 10) in which the rats underwent sham castration (2) a castrated group (TD group for testosterone deficiency, n = 10) in which the rats underwent bilateral orchidectomy surgery and (3) a castrated group given testosterone propionate via intraperitoneal injection (25 mg/kg/day) to supplement androgen (TD + TP group, n = 10). At ten weeks after castration in the noted groups, all rats were subjected to an oral glucose tolerance test (OGTT), a pyruvate tolerance test (PTT) and an insulin tolerance test (ITT). Twenty weeks following that treatment, all rats underwent a hyperinsulinemic-euglycemic clamp procedure in conjunction with isotope--labeled glucose and glycerol tracer infusions. The rate of appearance (Ra) of glucose, glycerol and gluconeogenesis (GNG), hepatic glucose production and the rate of glucose disappearance (Rd) were assessed. Glucose uptake was determined by measuring the 2-deoxy-D-14C-glucose in the gastrocnemius muscles. Results Ten weeks after castration in the TD group, the fasting blood glucose and insulin levels were significantly increased (p < 0.01), the glucose-- induced insulin secretion was impaired and ITT revealed a temporarily increased whole body insulin sensitivity compared with the control group; 30 weeks after castration, the Ra of glucose, Ra of glycerol, as well as the HGP and GNG were also increased (p < 0.01), while the exogenous glucose infusion rate and uptake glucose in the muscle markedly decreased (p

  8. Improvements in glucose tolerance and insulin action induced by increasing energy expenditure or decreasing energy intake: a randomized controlled trial.

    PubMed Central

    Weiss, Edward P.; Racette, Susan B.; Villareal, Dennis T.; Fontana, Luigi; Steger-May, Karen; Schechtman, Kenneth B.; Klein, Samuel; Holloszy, John O.

    2006-01-01

    Background Weight loss, through caloric restriction (CR) or increases in exercise energy expenditure (EX), improves glucose tolerance and insulin action. However, EX may further improve glucoregulation through weight-loss independent mechanisms. Objective To assess the hypothesis that weight loss through EX improves glucoregulation and circulating factors involved in insulin action, to a greater extent than does similar weight loss through CR. Design Sedentary 50- to 60-year-old men and women (body mass index=23.5–29.9 kg/m2) were randomized to 12-month EX (n=18) or CR (n=18) weight loss interventions or to a healthy lifestyle (HL) control group (n=10). Insulin sensitivity index (ISI) and the glucose and insulin areas under the curve (AUCs) were assessed by oral glucose tolerance test (OGTT). Adiponectin and tumor necrosis factor-α (TNFα) were assessed in fasting serum. Fat mass was determined by DXA. Results Yearlong energy deficits were not different between EX and CR as evidenced by body weight and fat mass changes. ISI increased, and the glucose and insulin AUCs decreased in the EX and CR groups and remained unchanged in the HL group but did not differ between EX and CR. Marginally significant increases in adiponectin, and decreases in the TNFα-to-adiponectin ratio, occurred in the EX and CR groups but not in the HL group. Conclusions EX- and CR-induced weight losses are both effective for improving glucose tolerance and insulin action in non-obese, healthy, middle-aged men and women; however, it does not appear that exercise training-induced weight loss results in greater improvements than those that result from CR. PMID:17093155

  9. Blood glucose monitoring.

    PubMed

    Davey, Sarah

    2014-06-10

    I found the CPD article on blood glucose monitoring and management in acute stroke care interesting and informative. As I am a mental health nursing student, my knowledge of chronic physical conditions is limited, so I learned a lot. PMID:24894257

  10. Glucose Tolerance and Hyperkinesis.

    ERIC Educational Resources Information Center

    Langseth, Lillian; Dowd, Judith

    Examined were medical records of 265 hyperkinetic children (7-9 years old). Clinical blood chemistries, hematology, and 5-hour glucose tolerance test (GTT) results indicated that hematocrit levels were low in 27% of the Ss, eosinophil levels were abnormally high in 86% of the Ss, and GTT results were abnormal in a maority of Ss. (CL)

  11. Glucose urine test

    MedlinePlus

    ... with a color-sensitive pad. The color the dipstick changes to tells the provider the level of glucose in your urine. If needed, your provider may ask you to collect your urine at home over 24 hours . Your provider will tell you how to do ...

  12. Renal Glucose Handling

    PubMed Central

    Ferrannini, Ele; Veltkamp, Stephan A.; Smulders, Ronald A.; Kadokura, Takeshi

    2013-01-01

    OBJECTIVE Ipragliflozin, a sodium-glucose cotransporter 2 inhibitor, stimulates glycosuria and lowers glycemia in patients with type 2 diabetes (T2DM). The objective of this study was to assess the pharmacodynamics of ipragliflozin in T2DM patients with impaired renal function. RESEARCH DESIGN AND METHODS Glycosuria was measured before and after a single ipragliflozin dose in 8 nondiabetic subjects and 57 T2DM patients (age 62 ± 9 years, fasting glucose 133 ± 39 mg/dL, mean ± SD) with normal renal function (assessed as the estimated glomerular filtration rate [eGFR]) (eGFR1 ≥90 mL · min–1 · 1.73 m−2), mild (eGFR2 ≥60 to <90), moderate (eGFR3 ≥30 to <60), or severe reduction in eGFR (eGFR4 ≤15 to <30). RESULTS Ipragliflozin significantly increased urinary glucose excretion in each eGFR class (P < 0.0001). However, ipragliflozin-induced glycosuria declined (median [IQR]) across eGFR class (from 46 mg/min [33] in eGFR1 to 8 mg/min [7] in eGFR4, P < 0.001). Ipragliflozin-induced fractional glucose excretion (excretion/filtration) was 39% [27] in the T2DM patients (pooled data), similar to that of the nondiabetic subjects (37% [17], P = ns). In bivariate analysis of the pooled data, ipragliflozin-induced glycosuria was directly related to eGFR and fasting glucose (P < 0.0001 for both, r2 = 0.55), predicting a decrement in 24-h glycosuria of 15 g for each 20 mL/min decline in eGFR and an increase of 7 g for each 10 mg/dL increase in glucose above fasting normoglycemia. CONCLUSIONS In T2DM patients, ipragliflozin increases glycosuria in direct, linear proportion to GFR and degree of hyperglycemia, such that its amount can be reliably predicted in the individual patient. Although absolute glycosuria decreases with declining GFR, the efficiency of ipragliflozin action (fractional glucose excretion) is maintained in patients with severe renal impairment. PMID:23359360

  13. Glucose Metabolism in Neisseria gonorrhoeae

    PubMed Central

    Morse, Stephen A.; Stein, Stefanie; Hines, James

    1974-01-01

    The metabolism of glucose was examined in several clinical isolates of Neisseria gonorrhoeae. Radiorespirometric studies revealed that growing cells metabolized glucose by a combination on the Entner-Doudoroff and pentose phosphate pathways. A portion of the glyceraldehyde-3-phosphate formed via the Entner-Doudoroff pathway was recycled by conversion to glucose-6-phosphate. Subsequent catabolism of this glucose-6-phosphate by either the Entner-Doudoroff or pentose phosphate pathways yielded CO2 from the original C6 of glucose. Enzyme analyses confirmed the presence of all enzymes of the Entner-Doudoroff, pentose phosphate, and Embden-Meyerhof-Parnas pathways. There was always a high specific activity of glucose-6-phosphate dehydrogenase (EC 1.1.1.49) relative to that of 6-phosphogluconate dehydrogenase (EC 1.1.1.44). The glucose-6-phosphate dehydrogenase utilized either nicotinamide adenine dinucleotide phosphate or nicotinamide adenine dinucleotide as electron acceptor. Acetate was the only detectable nongaseous end product of glucose metabolism. Following the disappearance of glucose, acetate was metabolized by the tricarboxylic acid cycle as evidenced by the preferential oxidation of [1-14C]acetate over that of [2-14C]acetate. When an aerobically grown log-phase culture was subjected to anaerobic conditions, lactate and acetate were formed from glucose. Radiorespirometric studies showed that under these conditions, glucose was dissimilated entirely by the Entner-Doudoroff pathway. Further studies determined that this anaerobic dissimilation of glucose was not growth dependent. PMID:4156358

  14. Coconut-derived D-xylose affects postprandial glucose and insulin responses in healthy individuals

    PubMed Central

    Bae, Yun Jung; Bak, Youn-Kyung; Kim, Bumsik; Kim, Min-Sun; Lee, Jin-Hee

    2011-01-01

    Metabolic alterations including postprandial hyperglycemia have been implicated in the development of obesity-related diseases. Xylose is a sucrase inhibitor suggested to suppress the postprandial glucose surge. The objectives of this study were to assess the inhibitory effects of two different concentrations of xylose on postprandial glucose and insulin responses and to evaluate its efficacy in the presence of other macronutrients. Randomized double-blind cross-over studies were conducted to examine the effect of D-xylose on postprandial glucose and insulin response following the oral glucose tolerance test (OGTT). In study 1, the overnight-fasted study subjects (n = 49) consumed a test sucrose solution (50 g sucrose in 130 ml water) containing 0, 5, or 7.5 g D-xylose powder. In study 2, the overnight-fasted study subjects (n = 50) consumed a test meal (50 g sucrose in a 60 g muffin and 200 ml sucrose-containing solution). The control meal provided 64.5 g of carbohydrates, 4.5 g of fat, and 10 g of protein. The xylose meal was identical to the control meal except 5 g of xylose was added to the muffin mix. In study 1, the 5 g xylose-containing solutions exhibited significantly lower area under the glucose curve (AUCg) and area under the insulin curve (AUCi) values for 0-15 min (P < 0.0001, P < 0.0001), 0-30 min (P < 0.0001, P < 0.0001), 0-45 min (P < 0.0001, P < 0.0001), 0-60 min (P < 0.0001, P < 0.0001), 0-90 min (P < 0.0001, P < 0.0001) and 0-120 min (P = 0.0071, P = 0.0016). In study 2, the test meal exhibited significantly lower AUCg and AUCi values for 0-15 min (P < 0.0001, P < 0.0001), 0-30 min (P < 0.0001, P < 0.0001), 0-45 min (P < 0.0001, P = 0.0005), 0-60 min (P = 0.0002, P = 0.0025), and 0-90 min (P = 0.0396, P = 0.0246). In conclusion, xylose showed an acute suppressive effect on the postprandial glucose and insulin surges. PMID:22259678

  15. Glucose and Aging

    NASA Astrophysics Data System (ADS)

    Ely, John T. A.

    2008-04-01

    When a human's enzymes attach glucose to proteins they do so at specific sites on a specific molecule for a specific purpose that also can include ascorbic acid (AA) at a high level such as 1 gram per hour during exposure. In an AA synthesizing animal the manifold increase of AA produced in response to illness is automatic. In contrast, the human non-enzymatic process adds glucose haphazardly to any number of sites along available peptide chains. As Cerami clarified decades ago, extensive crosslinking of proteins contributes to loss of elasticity in aging tissues. Ascorbic acid reduces the random non-enyzmatic glycation of proteins. Moreover, AA is a cofactor for hydroxylase enzymes that are necessary for the production and replacement of collagen and other structural proteins. We will discuss the relevance of ``aging is scurvy'' to the biochemistry of human aging.

  16. Effects of simulated acid rain on glucose mineralization and some physicochemical properties of forest soils

    SciTech Connect

    Strayer, R.F.; Alexander, M.

    1981-10-01

    To study the effects of acid rain, samples of forest soils were exposed to a continuous application of 100 cm of simulated acid rain (pH 3.2-4.1) at 5 cm/hour, or to intermittent 1-hour applications of 5 cm of simulated acid rain three times per week for 7 weeks. The major effects of the simulated acid rain were localized at the top of the soil and included lower pH values and glucose mineralization rates, and higher exchangeable Al and total and exchange acidity. The acidity penetrated further in the more acid soils. The mineralization of /sup 14/C-glucose was measured at concentrations of 1.5-54 ..mu..g glucose/g of soil. Glucose mineralization in the test soils (pH values of 4.4-7.1) was inhibited by the continuous exposure to simulated acid rain at pH 3.2 but not a pH 4.1. The extent of inhibition depended on the soil and the initial glucose concentration. Exposure of one soil to 7 weeks of intermittent applications of simulated acid rain at pH 3.2 reduced the mineralization rate at the three glucose concentrations tested. These data suggest that acid rain may have a significant impact on microbial activity.

  17. Glucose-6-phosphate isomerase.

    PubMed

    Achari, A; Marshall, S E; Muirhead, H; Palmieri, R H; Noltmann, E A

    1981-06-26

    Glucose-6-phosphate isomerase (EC 5.3.1.9) is a dimeric enzyme of molecular mass 132000 which catalyses the interconversion of D-glucose-6-phosphate and D-fructose-6-phosphate. The crystal structure of the enzyme from pig muscle has been determined at a nominal resolution of 2.6 A. The structure is of the alpha/beta type. Each subunit consists of two domains and the active site is in both the domain interface and the subunit interface (P.J. Shaw & H. Muirhead (1976), FEBS Lett. 65, 50-55). Each subunit contains 13 methionine residues so that cyanogen bromide cleavage will produce 14 fragments, most of which have been identified and at least partly purified. Sequence information is given for about one-third of the molecule from 5 cyanogen bromide fragments. One of the sequences includes a modified lysine residue. Modification of this residue leads to a parallel loss of enzymatic activity. A tentative fit of two of the peptides to the electron density map has been made. It seems possible that glucose-6-phosphate isomerase, triose phosphate isomerase and pyruvate kinase all contain a histidine and a glutamate residue at the active site. PMID:6115414

  18. Cholecystokinin, glucose dependent insulinotropic peptide and glucagon-like peptide 1 secretion in children with anorexia nervosa and simple obesity.

    PubMed

    Tomasik, Przemyslaw J; Sztefko, Krystyna; Starzyk, Jerzy

    2004-12-01

    Cholecystokinin (CCK), glucose dependent insulinotropic peptide (GIP), and glucagon-like peptide 1 (GLP-1) regulate satiety as enterogastrons and incretins. They also directly affect the satiety centers. Therefore, these peptides may participate in the pathogenesis of eating disorders. CCK, GIP, and GLP-1 secretion were studied in 13 adolescent girls suffering from simple obesity, 13 girls with anorexia nervosa, and 10 healthy girls. Each girl was subjected to an oral glucose tolerance test (OGTT) and standard meal test. Blood was collected before stimulation and at 15, 30, 60, and 120 min. The concentrations of all peptides were determined by RIA commercial kits. Fasting and postprandial levels of these peptides as well as integrated outputs were measured. High postprandial levels of CCK observed in the girls with anorexia may aggravate the course of this disease by intensifying nausea and vomiting. Low postprandial level of GLP-1 in girls with simple obesity may be responsible for excessive ingestion of food and weaker inhibition of gastric emptying, which also leads to obesity. PMID:15645696

  19. Altered glucose metabolism rather than naive type 2 diabetes mellitus (T2DM) is related to vitamin D status in severe obesity

    PubMed Central

    2014-01-01

    Context The last decades have provided insights into vitamin D physiology linked to glucose homeostasis. Uncertainties remain in obesity due to its intrinsic effects on vitamin D and glucose tolerance. Objectives To assess the relationship between vitamin D and glucose abnormalities in severely obese individuals previously unknown to suffer from abnormal glucose metabolism. Setting Tertiary care centre. Patients 524 obese patients (50.3 ± 14.9 yrs; BMI, 47.7 ± 7.3 kg/m2) screened by OGTT, HbA1c and the lipid profile. Vitamin D status was assessed by 25(OH)D3, PTH and electrolyte levels. 25(OH)D3 deficiency/insufficiency were set at 20 and 30 ng/ml, respectively. All comparative and regression analyses were controlled for age, BMI and gender. Results The prevalence of vitamin D deficiency/insufficiency and secondary hyperparathyroidism were 95% and 50.8%, respectively. Normal glucose tolerance (NGT), impaired fasting glucose (IFG) or impaired glucose tolerance (IGT), and type 2 diabetes mellitus (T2DM) were found in 37.8%, 40.5% and 21.7% of cases, respectively. Large variations in metabolic parameters were seen across categories of vitamin D status, but the only significant differences were found for C-peptide, tryglicerides, LDL- and HDL-cholesterol levels (p < 0.05 for all). The prevalence of vitamin D deficiency was documented to be slightly but significantly more frequent in glucose-intolerant patients (IFG + IGT + T2DM) compared to the -normotolerant counterpart (87% vs. 80%, p < 0.05). In partial correlation analyses, there was no association between vitamin D levels and glucose-related markers but for HbA1c (r = −0.091, p < 0.05), and both basal and OGTT-stimulated insulin levels (r = 0.097 and r = 0.099; p < 0.05 for all). Vitamin D levels were also correlated to HDL-cholesterol (r = 0.13, p = 0.002). Multivariate regression analysis inclusive of vitamin D, age, BMI, gender and fat mass as

  20. Silver nanoparticles affect glucose metabolism in hepatoma cells through production of reactive oxygen species

    PubMed Central

    Lee, Mi Jin; Lee, Seung Jun; Yun, Su Jin; Jang, Ji-Young; Kang, Hangoo; Kim, Kyongmin; Choi, In-Hong; Park, Sun

    2016-01-01

    The silver nanoparticle (AgNP) is a candidate for anticancer therapy because of its effects on cell survival and signaling. Although numerous reports are available regarding their effect on cell death, the effect of AgNPs on metabolism is not well understood. In this study, we investigated the effect of AgNPs on glucose metabolism in hepatoma cell lines. Lactate release from both HepG2 and Huh7 cells was reduced with 5 nm AgNPs as early as 1 hour after treatment, when cell death did not occur. Treatment with 5 nm AgNPs decreased glucose consumption in HepG2 cells but not in Huh7 cells. Treatment with 5 nm AgNPs reduced nuclear factor erythroid 2-like 2 expression in both cell types without affecting its activation at the early time points after AgNPs’ treatment. Increased reactive oxygen species (ROS) production was detected 1 hour after 5 nm AgNPs’ treatment, and lactate release was restored in the presence of an ROS scavenger. Our results suggest that 5 nm AgNPs affect glucose metabolism by producing ROS. PMID:26730190

  1. Relationship between HbA1c and Continuous Glucose Monitoring in Chinese Population: A Multicenter Study

    PubMed Central

    Li, Hong; Ran, Xingwu; Yang, Wenying; Li, Qiang; Peng, Yongde; Li, Yanbing; Gao, Xin; Luan, Xiaojun; Wang, Weiqing; Xie, Yun; Jia, Weiping

    2013-01-01

    Objective Since there is a paucity of reference data in the literature to indicate the relationship between HbA1c, and 24 h mean blood glucose (MBG) from continuous glucose monitoring (CGM) in Chinese populations, we described the above relationship in adult Chinese subjects with different glucose tolerance status. Methods Seven-hundred-and-forty-two individuals without history of diabetes were included to the study at 11 hospitals in urban areas across China from 2007–2009 and data of 673 subjects were included into the final analysis. Oral glucose tolerance test (OGTT) classified the participants as nondiabetic subjects, including those with normal glucose regulation (NGR; n = 121) and impaired glucose regulation (IGR; n = 209), or newly diagnosed type 2 diabetes (n = 343). All participants completed testing for HbA1c levels and wore a CGM system for three consecutive days. The 24 h MBG levels were calculated. Spearman correlations and linear regression analyses were applied to quantify the relationship between glucose markers. Results The levels of HbA1c and 24 h MBG significantly increased with presence of glucose intolerance (NGR

  2. How well are pregnant women in Croatia informed about the oral glucose tolerance test?

    PubMed Central

    Kocijancic, Marija

    2015-01-01

    Introduction Preanalytical errors still constitute the largest source of errors in laboratory work. Proper patient preparation and patient’s knowledge about a particular procedure affects its accuracy and reliability. We hypothesized that most of pregnant women are not well enough informed about the proper procedure for the OGTT. The aims of this study were to investigate: (i) how well pregnant women are informed about the OGTT; (ii) the most common way to inform pregnant women about OGTT and (iii) whether pregnant women’s level of knowledge about the OGTT differ regarding source of information. Materials and methods The anonymous questionnaire was conducted across the country in 23 Croatian primary and secondary healthcare centres. The questionnaire contained 9 questions on certain demographic data and familiarity with OGTT procedure. All 343 participants filled the questionnaire before the first blood draw. Results 42% of the participants demonstrated high and 38% adequate level of knowledge about the OGTT procedure. Majority of participants were informed about the procedure by gynaecologist (56%). The level of knowledge differed among participants with different sources of information (P = 0.030). Further analysis showed that the level of knowledge was lower in pregnant women having received information from their gynaecologist compared to pregnant women who received information from the laboratory staff. Conclusions In general, pregnant women are familiar with OGTT procedure, main source of information about the OGTT procedure is their gynaecologist, but the level of knowledge was higher in women who received information about the OGTT procedure from the laboratory staff. PMID:26110035

  3. Morning cortisol levels and glucose metabolism parameters in moderate and severe obstructive sleep apnea patients.

    PubMed

    Bozic, Josko; Galic, Tea; Supe-Domic, Daniela; Ivkovic, Natalija; Ticinovic Kurir, Tina; Valic, Zoran; Lesko, Josip; Dogas, Zoran

    2016-09-01

    Obstructive sleep apnea (OSA) has been associated with dysregulation of the hypothalamic-pituitary-adrenal axis and alterations in glucose metabolism with increased risk for type 2 diabetes. The aim of the current study was to compare morning plasma cortisol levels and glucose metabolism parameters between moderate (apnea-hypopnea index (AHI): 15-30 events/h) and severe OSA patients (AHI >30 events/h), with respective controls. A total of 56 male OSA patients, 24 moderate (AHI = 21.1 ± 5.3) and 32 severe (AHI = 49.7 ± 18.1), underwent a full-night polysomnography, oral glucose tolerance test (OGTT), and measurement of morning plasma cortisol levels. These groups were compared to 20 matched subjects in a control group. Morning plasma cortisol levels were statistically lower in severe OSA group than in moderate OSA and control groups (303.7 ± 93.5 vs. 423.9 ± 145.1 vs. 417.5 ± 99.8 pmol/L, P < 0.001). Significant negative correlations were found between morning plasma cortisol levels and AHI (r = -0.444, P = 0.002), as well as oxygen desaturation index (r = -0.381, P = 0.011). Fasting plasma glucose (5.0 ± 0.5 vs. 5.4 ± 0.7 vs. 4.9 ± 0.6 mmol/L, P = 0.009) was higher in the severe OSA group compared to moderate OSA and controls. Homeostasis model assessment insulin resistance (HOMA-IR) was higher in the severe OSA group compared to moderate OSA and controls (4.6 ± 3.7 vs. 2.7 ± 2.0 and 2.2 ± 1.8, respectively, P = 0.006). In conclusion, our study showed that morning plasma cortisol levels measured at 8 a.m. were significantly lower in severe OSA patients than those in moderate OSA group and controls. Morning plasma cortisol levels showed a negative correlation with AHI and oxygen desaturation index. Additionally, this study confirmed the evidence of glucose metabolism impairment in moderate and severe OSA patients, with more pronounced effect in the severe OSA patients group. PMID:27000083

  4. Glucose repression in Saccharomyces cerevisiae.

    PubMed

    Kayikci, Ömur; Nielsen, Jens

    2015-09-01

    Glucose is the primary source of energy for the budding yeast Saccharomyces cerevisiae. Although yeast cells can utilize a wide range of carbon sources, presence of glucose suppresses molecular activities involved in the use of alternate carbon sources as well as it represses respiration and gluconeogenesis. This dominant effect of glucose on yeast carbon metabolism is coordinated by several signaling and metabolic interactions that mainly regulate transcriptional activity but are also effective at post-transcriptional and post-translational levels. This review describes effects of glucose repression on yeast carbon metabolism with a focus on roles of the Snf3/Rgt2 glucose-sensing pathway and Snf1 signal transduction in establishment and relief of glucose repression. PMID:26205245

  5. Glucose repression in Saccharomyces cerevisiae

    PubMed Central

    Kayikci, Ömur; Nielsen, Jens

    2015-01-01

    Glucose is the primary source of energy for the budding yeast Saccharomyces cerevisiae. Although yeast cells can utilize a wide range of carbon sources, presence of glucose suppresses molecular activities involved in the use of alternate carbon sources as well as it represses respiration and gluconeogenesis. This dominant effect of glucose on yeast carbon metabolism is coordinated by several signaling and metabolic interactions that mainly regulate transcriptional activity but are also effective at post-transcriptional and post-translational levels. This review describes effects of glucose repression on yeast carbon metabolism with a focus on roles of the Snf3/Rgt2 glucose-sensing pathway and Snf1 signal transduction in establishment and relief of glucose repression. PMID:26205245

  6. Optoelectronic Apparatus Measures Glucose Noninvasively

    NASA Technical Reports Server (NTRS)

    Ansari, Rafat R.; Rovati, Luigi L.

    2003-01-01

    An optoelectronic apparatus has been invented as a noninvasive means of measuring the concentration of glucose in the human body. The apparatus performs polarimetric and interferometric measurements of the human eye to acquire data from which the concentration of glucose in the aqueous humor can be computed. Because of the importance of the concentration of glucose in human health, there could be a large potential market for instruments based on this apparatus.

  7. Optical monitoring of glucose concentration

    NASA Astrophysics Data System (ADS)

    Ross, I. N.; Mbanu, A.

    1985-02-01

    A device for the monitoring of blood glucose levels is investigated. It measures the sugar concentration using the effect of the glucose on the optical refractive index. Light is transmitted along an optical fibre, and, as most of the internal rays are incident at the fibre surface at an angle less than the critical angle, the refractive index of the surrounding liquid can be calculated. The device can measure glucose concentrations with a sensitivity of better than 0.1%.

  8. Thermoresponsive amperometric glucose biosensor.

    PubMed

    Pinyou, Piyanut; Ruff, Adrian; Pöller, Sascha; Barwe, Stefan; Nebel, Michaela; Alburquerque, Natalia Guerrero; Wischerhoff, Erik; Laschewsky, André; Schmaderer, Sebastian; Szeponik, Jan; Plumeré, Nicolas; Schuhmann, Wolfgang

    2016-03-01

    The authors report on the fabrication of a thermoresponsive biosensor for the amperometric detection of glucose. Screen printed electrodes with heatable gold working electrodes were modified by a thermoresponsive statistical copolymer [polymer I: poly(ω-ethoxytriethylenglycol methacrylate-co-3-(N,N-dimethyl-N-2-methacryloyloxyethyl ammonio) propanesulfonate-co-ω-butoxydiethylenglycol methacrylate-co-2-(4-benzoyl-phenoxy)ethyl methacrylate)] with a lower critical solution temperature of around 28 °C in aqueous solution via electrochemically induced codeposition with a pH-responsive redox-polymer [polymer II: poly(glycidyl methacrylate-co-allyl methacrylate-co-poly(ethylene glycol)methacrylate-co-butyl acrylate-co-2-(dimethylamino)ethyl methacrylate)-[Os(bpy)2(4-(((2-(2-(2-aminoethoxy)ethoxy)ethyl)amino)methyl)-N,N-dimethylpicolinamide)](2+)] and pyrroloquinoline quinone-soluble glucose dehydrogenase acting as biological recognition element. Polymer II bears covalently bound Os-complexes that act as redox mediators for shuttling electrons between the enzyme and the electrode surface. Polymer I acts as a temperature triggered immobilization matrix. Probing the catalytic current as a function of the working electrode temperature shows that the activity of the biosensor is dramatically reduced above the phase transition temperature of polymer I. Thus, the local modulation of the temperature at the interphase between the electrode and the bioactive layer allows switching the biosensor from an on- to an off-state without heating of the surrounding analyte solution. PMID:26702635

  9. Dietary fructose and glucose differentially affect lipid and glucose homeostasis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Absorbed glucose and fructose differ in that glucose largely escapes first pass removal by the liver, whereas fructose does not, resulting in different metabolic effects of these two monosaccharides. In short-term controlled feeding studies, dietary fructose significantly increases postprandial trig...

  10. Dietary fructose and glucose differentially affect lipid and glucose homeostasis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Absorbed glucose and fructose differ in that glucose largely escapes first-pass removal by the liver, whereas fructose does not, resulting in different metabolic effects of these 2 monosaccharides. In short-term controlled feeding studies, dietary fructose significantly increases postprandial trigly...

  11. Alginate cryogel based glucose biosensor

    NASA Astrophysics Data System (ADS)

    Fatoni, Amin; Windy Dwiasi, Dian; Hermawan, Dadan

    2016-02-01

    Cryogel is macroporous structure provides a large surface area for biomolecule immobilization. In this work, an alginate cryogel based biosensor was developed to detect glucose. The cryogel was prepared using alginate cross-linked by calcium chloride under sub-zero temperature. This porous structure was growth in a 100 μL micropipette tip with a glucose oxidase enzyme entrapped inside the cryogel. The glucose detection was based on the colour change of redox indicator, potassium permanganate, by the hydrogen peroxide resulted from the conversion of glucose. The result showed a porous structure of alginate cryogel with pores diameter of 20-50 μm. The developed glucose biosensor was showed a linear response in the glucose detection from 1.0 to 5.0 mM with a regression of y = 0.01x+0.02 and R2 of 0.994. Furthermore, the glucose biosensor was showed a high operational stability up to 10 times of uninterrupted glucose detections.

  12. Antihypertensive drugs and glucose metabolism

    PubMed Central

    Rizos, Christos V; Elisaf, Moses S

    2014-01-01

    Hypertension plays a major role in the development and progression of micro- and macrovascular disease. Moreover, increased blood pressure often coexists with additional cardiovascular risk factors such as insulin resistance. As a result the need for a comprehensive management of hypertensive patients is critical. However, the various antihypertensive drug categories have different effects on glucose metabolism. Indeed, angiotensin receptor blockers as well as angiotensin converting enzyme inhibitors have been associated with beneficial effects on glucose homeostasis. Calcium channel blockers (CCBs) have an overall neutral effect on glucose metabolism. However, some members of the CCBs class such as azelnidipine and manidipine have been shown to have advantageous effects on glucose homeostasis. On the other hand, diuretics and β-blockers have an overall disadvantageous effect on glucose metabolism. Of note, carvedilol as well as nebivolol seem to differentiate themselves from the rest of the β-blockers class, being more attractive options regarding their effect on glucose homeostasis. The adverse effects of some blood pressure lowering drugs on glucose metabolism may, to an extent, compromise their cardiovascular protective role. As a result the effects on glucose homeostasis of the various blood pressure lowering drugs should be taken into account when selecting an antihypertensive treatment, especially in patients which are at high risk for developing diabetes. PMID:25068013

  13. Glucose oxidase-magnetite nanoparticle bioconjugate for glucose sensing.

    PubMed

    Rossi, Liane M; Quach, Ashley D; Rosenzweig, Zeev

    2004-10-01

    Immobilization of bioactive molecules on the surface of magnetic nanoparticles is of great interest, because the magnetic properties of these bioconjugates promise to greatly improve the delivery and recovery of biomolecules in biomedical applications. Here we present the preparation and functionalization of magnetite (Fe3O4) nanoparticles 20 nm in diameter and the successful covalent conjugation of the enzyme glucose oxidase to the amino-modified nanoparticle surface. Functionalization of the magnetic nanoparticle surface with amino groups greatly increased the amount and activity of the immobilized enzyme compared with immobilization procedures involving physical adsorption. The enzymatic activity of the glucose oxidase-coated magnetic nanoparticles was investigated by monitoring oxygen consumption during the enzymatic oxidation of glucose using a ruthenium phenanthroline fluorescent complex for oxygen sensing. The glucose oxidase-coated magnetite nanoparticles could function as nanometric glucose sensors in glucose solutions of concentrations up to 20 mmol L(-1). Immobilization of glucose oxidase on the nanoparticles also increased the stability of the enzyme. When stored at 4 degrees C the nanoparticle suspensions maintained their bioactivity for up to 3 months. PMID:15448967

  14. Glucose-stat, a glucose-controlled continuous culture.

    PubMed Central

    Kleman, G L; Chalmers, J J; Luli, G W; Strohl, W R

    1991-01-01

    A predictive and feedback proportional control algorithm, developed for fed-batch fermentations and described in a companion paper (G. L. Kleman, J. J. Chalmers, G. W. Luli, and W. R. Strohl, Appl. Environ. Microbiol. 57:910-917, 1991), was used in this work to control a continuous culture on the basis of the soluble-glucose concentration (called the glucose-stat). This glucose-controlled continuous-culture system was found to reach and maintain steady state for 11 to 24 residence times when four different background glucose concentrations (0.27, 0.50, 0.7, and 1.5 g/liter) were used. The predictive-plus-feedback control system yielded very tight control of the continuous nutristat cultures; glucose concentrations were maintained at the set points with less than 0.003 standard error. Acetate production by Escherichia coli B in glucose-stats was found not to be correlated with the level of steady-state soluble-glucose concentration. PMID:2059050

  15. Glucose-stat, a glucose-controlled continuous culture.

    PubMed

    Kleman, G L; Chalmers, J J; Luli, G W; Strohl, W R

    1991-04-01

    A predictive and feedback proportional control algorithm, developed for fed-batch fermentations and described in a companion paper (G. L. Kleman, J. J. Chalmers, G. W. Luli, and W. R. Strohl, Appl. Environ. Microbiol. 57:910-917, 1991), was used in this work to control a continuous culture on the basis of the soluble-glucose concentration (called the glucose-stat). This glucose-controlled continuous-culture system was found to reach and maintain steady state for 11 to 24 residence times when four different background glucose concentrations (0.27, 0.50, 0.7, and 1.5 g/liter) were used. The predictive-plus-feedback control system yielded very tight control of the continuous nutristat cultures; glucose concentrations were maintained at the set points with less than 0.003 standard error. Acetate production by Escherichia coli B in glucose-stats was found not to be correlated with the level of steady-state soluble-glucose concentration. PMID:2059050

  16. The glucose-6-phosphatase system.

    PubMed Central

    van Schaftingen, Emile; Gerin, Isabelle

    2002-01-01

    Glucose-6-phosphatase (G6Pase), an enzyme found mainly in the liver and the kidneys, plays the important role of providing glucose during starvation. Unlike most phosphatases acting on water-soluble compounds, it is a membrane-bound enzyme, being associated with the endoplasmic reticulum. In 1975, W. Arion and co-workers proposed a model according to which G6Pase was thought to be a rather unspecific phosphatase, with its catalytic site oriented towards the lumen of the endoplasmic reticulum [Arion, Wallin, Lange and Ballas (1975) Mol. Cell. Biochem. 6, 75--83]. Substrate would be provided to this enzyme by a translocase that is specific for glucose 6-phosphate, thereby accounting for the specificity of the phosphatase for glucose 6-phosphate in intact microsomes. Distinct transporters would allow inorganic phosphate and glucose to leave the vesicles. At variance with this substrate-transport model, other models propose that conformational changes play an important role in the properties of G6Pase. The last 10 years have witnessed important progress in our knowledge of the glucose 6-phosphate hydrolysis system. The genes encoding G6Pase and the glucose 6-phosphate translocase have been cloned and shown to be mutated in glycogen storage disease type Ia and type Ib respectively. The gene encoding a G6Pase-related protein, expressed specifically in pancreatic islets, has also been cloned. Specific potent inhibitors of G6Pase and of the glucose 6-phosphate translocase have been synthesized or isolated from micro-organisms. These as well as other findings support the model initially proposed by Arion. Much progress has also been made with regard to the regulation of the expression of G6Pase by insulin, glucocorticoids, cAMP and glucose. PMID:11879177

  17. Conversion of glucose to sorbose

    DOEpatents

    Davis, Mark E.; Gounder, Rajamani

    2016-02-09

    The present invention is directed to methods for preparing sorbose from glucose, said method comprising: (a) contacting the glucose with a silica-containing structure comprising a zeolite having a topology of a 12 membered-ring or larger, an ordered mesoporous silica material, or an amorphous silica, said structure containing Lewis acidic Ti.sup.4+ or Zr.sup.4+ or both Ti.sup.4+ and Zr.sup.4+ framework centers, said contacting conducted under reaction conditions sufficient to isomerize the glucose to sorbose. The sorbose may be (b) separated or isolated; or (c) converted to ascorbic acid.

  18. Effect of Low Frequency Neuromuscular Electrical Stimulation on Glucose Profile of Persons with Type 2 Diabetes: A Pilot Study

    PubMed Central

    Belliveau, Lise; Probizanski, David; Newhouse, Ian; McAuliffe, Jim; Jakobi, Jennifer; Johnson, Michel

    2015-01-01

    The purpose of this study was to examine the effect of low-frequency neuromuscular electrical stimulation (NMES) on glucose profile in persons with type 2 diabetes mellitus (T2DM). Eight persons with T2DM (41 to 65 years) completed a glucose tolerance test with and without NMES delivered to the knee extensors for a 1-hour period at 8 Hz. Three blood samples were collected: at rest, and then 60 and 120 minutes after consumption of a glucose load on the NMES and control days. In NMES groups glucose concentrations were significantly lower (P<0.01) than in the control conditions. Moreover, a significant positive correlation (r=0.9, P<0.01) was obtained between the intensity of stimulation and changes in blood glucose. Our results suggest that low-frequency stimulation seem suitable to induce enhance glucose uptake in persons with T2DM. Moreover, the intensity of stimulation reflecting the motor contraction should be considered during NMES procedure. PMID:26124997

  19. [Contribution of the kidney to glucose homeostasis].

    PubMed

    Segura, Julián; Ruilope, Luis Miguel

    2013-09-01

    The kidney is involved in glucose homeostasis through three major mechanisms: renal gluconeogenesis, renal glucose consumption, and glucose reabsorption in the proximal tubule. Glucose reabsorption is one of the most important physiological functions of the kidney, allowing full recovery of filtered glucose, elimination of glucose from the urine, and prevention of calorie loss. Approximately 90% of the glucose is reabsorbed in the S1 segment of the proximal tubule, where glucose transporter-2 (GLUT2) and sodium-glucose transporter-2 (SGLT2) are located, while the remaining 10% is reabsorbed in the S3 segment by SGLT1 and GLUT1 transporters. In patients with hyperglycemia, the kidney continues to reabsorb glucose, thus maintaining hyperglycemia. Most of the renal glucose reabsorption is mediated by SGLT2. Several experimental and clinical studies suggest that pharmacological blockade of this transporter might be beneficial in the management of hyperglycemia in patients with type 2 diabetes. PMID:24444521

  20. Glucose-6-phosphatase deficiency

    PubMed Central

    2011-01-01

    Glucose-6-phosphatase deficiency (G6P deficiency), or glycogen storage disease type I (GSDI), is a group of inherited metabolic diseases, including types Ia and Ib, characterized by poor tolerance to fasting, growth retardation and hepatomegaly resulting from accumulation of glycogen and fat in the liver. Prevalence is unknown and annual incidence is around 1/100,000 births. GSDIa is the more frequent type, representing about 80% of GSDI patients. The disease commonly manifests, between the ages of 3 to 4 months by symptoms of hypoglycemia (tremors, seizures, cyanosis, apnea). Patients have poor tolerance to fasting, marked hepatomegaly, growth retardation (small stature and delayed puberty), generally improved by an appropriate diet, osteopenia and sometimes osteoporosis, full-cheeked round face, enlarged kydneys and platelet dysfunctions leading to frequent epistaxis. In addition, in GSDIb, neutropenia and neutrophil dysfunction are responsible for tendency towards infections, relapsing aphtous gingivostomatitis, and inflammatory bowel disease. Late complications are hepatic (adenomas with rare but possible transformation into hepatocarcinoma) and renal (glomerular hyperfiltration leading to proteinuria and sometimes to renal insufficiency). GSDI is caused by a dysfunction in the G6P system, a key step in the regulation of glycemia. The deficit concerns the catalytic subunit G6P-alpha (type Ia) which is restricted to expression in the liver, kidney and intestine, or the ubiquitously expressed G6P transporter (type Ib). Mutations in the genes G6PC (17q21) and SLC37A4 (11q23) respectively cause GSDIa and Ib. Many mutations have been identified in both genes,. Transmission is autosomal recessive. Diagnosis is based on clinical presentation, on abnormal basal values and absence of hyperglycemic response to glucagon. It can be confirmed by demonstrating a deficient activity of a G6P system component in a liver biopsy. To date, the diagnosis is most commonly confirmed

  1. Glucose regulation of glucagon secretion.

    PubMed

    Gylfe, Erik; Gilon, Patrick

    2014-01-01

    Glucagon secreted by pancreatic α-cells is the major hyperglycemic hormone correcting acute hypoglycaemia (glucose counterregulation). In diabetes the glucagon response to hypoglycaemia becomes compromised and chronic hyperglucagonemia appears. There is increasing awareness that glucagon excess may underlie important manifestations of diabetes. However opinions differ widely how glucose controls glucagon secretion. The autonomous nervous system plays an important role in the glucagon response to hypoglycaemia. But it is clear that glucose controls glucagon secretion also by mechanisms involving direct effects on α-cells or indirect effects via paracrine factors released from non-α-cells within the pancreatic islets. The present review discusses these mechanisms and argues that different regulatory processes are involved in a glucose concentration-dependent manner. Direct glucose effects on the α-cell and autocrine mechanisms are probably most significant for the glucagon response to hypoglycaemia. During hyperglycaemia, when secretion from β- and δ-cells is stimulated, paracrine inhibitory factors generate pulsatile glucagon release in opposite phase to pulsatile release of insulin and somatostatin. High concentrations of glucose have also stimulatory effects on glucagon secretion that tend to balance and even exceed the inhibitory influence. The latter actions might underlie the paradoxical hyperglucagonemia that aggravates hyperglycaemia in persons with diabetes. PMID:24367972

  2. Diet restriction in Ramadan and the effect of fasting on glucose levels in pregnancy

    PubMed Central

    2014-01-01

    Background Maternal diet restriction might be associated with adverse maternal and perinatal outcomes due to metabolic changes. This study aimed to investigate the prevalence of changes in glucose levels due to Ramadan fasting in Emirati pregnant women. We conducted a cross-sectional observational study of 150 women from the United Arab Emirates, (76 during Ramadan and 74 after Ramadan), with uncomplicated pregnancies at a gestational age between 20 and 36 weeks. Results The two groups of pregnant women had similar physiological parameters. Using the oral glucose tolerance test, the mean random blood glucose level after 1 hour of breaking the fast was significantly higher (p = 0.002) in the Ramadan fasting group than in the control group, and this was not affected by the number of fasting days. In 50% of patients after Ramadan and 70.5% during Ramadan, this value was more than 6.7 mmol/l, which is high and not an acceptable postprandial level in pregnancy. Conclusion Caregivers need to consider the 1-hour postprandial glucose level response after fasting in Muslim pregnant women. Research of an interventional design is required to determine remedial actions for this issue. PMID:24962444

  3. A simple index for detection of gestational diabetes mellitus

    PubMed Central

    Perea-Carrasco, Rafael; Pérez-Coronel, Rocio; Albusac-Aguilar, Rogelio; Lombardo-Grifol, Manuel; de León, Elena Bassas-Baena; Romero-Diaz, Carlos

    2002-01-01

    The conventional screening test for gestational diabetes mellitus is measurement of plasma glucose 1 hour after 50 g glucose by mouth. The sensitivity and specificity of this test are lower than desirable; we therefore developed an index including other plasma constituents. In a preliminary study, 138 pregnant women had the standard oral glucose load screening test, and plasma fructosamine and total proteins were measured, in addition to glucose, in the 1-hour samples. An index value (I) was calculated as [fructosamine (μmol/L)÷total proteins (g/L)]×[glucose (mmol/L)÷100]. Cut-off values for I were then assessed in a second prospective study, of 642 pregnant women. Definitive diagnosis of gestational diabetes was by oral glucose tolerance test (OGTT). The index was also assessed in terms of fetal macrosomia (birthweight≥4000 g). With a cut-off value of I=27.2, sensitivity was 98%, specificity 89%, diagnostic efficiency 90%, positive likelihood ratio 8.76. Application of the index would have avoided 42% of the OGTTs demanded by the standard screening test, reducing false positives from about 24% to 10%. Predictive efficacy for macrosomia was 10.3% versus 7.9%. Our index offers an efficient screening test for gestational diabetes, and with more stringent cut-off points may be applicable as a single-step diagnostic procedure. PMID:12205206

  4. Microdegree porlarimetry for glucose concentrations detection

    NASA Astrophysics Data System (ADS)

    Wang, Hong; Wei, Yunlong; Zhou, Qi; Liu, Shenping; Chui, Jianguo

    2005-07-01

    Optical glucose measurement is an attractive research topic for years. One of the goals is to develop a noninvasive monitoring of long term, instantaneous blood glucose for diabetics. The principle of porlarimetry for glucose detection is introduced and several techniques of microdegree porlarimetry for glucose detection are summarized and the facts that effect measurement are discussed. Current and future research is focusing on the elimination of confounding factors such as other optically active substances for precise glucose detection.

  5. Phosphorylation of RS1 (RSC1A1) Steers Inhibition of Different Exocytotic Pathways for Glucose Transporter SGLT1 and Nucleoside Transporter CNT1, and an RS1-Derived Peptide Inhibits Glucose Absorption.

    PubMed

    Veyhl-Wichmann, Maike; Friedrich, Alexandra; Vernaleken, Alexandra; Singh, Smriti; Kipp, Helmut; Gorboulev, Valentin; Keller, Thorsten; Chintalapati, Chakravarthi; Pipkorn, Rüdiger; Pastor-Anglada, Marçal; Groll, Jürgen; Koepsell, Hermann

    2016-01-01

    Cellular uptake adapts rapidly to physiologic demands by changing transporter abundance in the plasma membrane. The human gene RSC1A1 codes for a 67-kDa protein named RS1 that has been shown to induce downregulation of the sodium-D-glucose cotransporter 1 (SGLT1) and of the concentrative nucleoside transporter 1 (CNT1) in the plasma membrane by blocking exocytosis at the Golgi. Injecting RS1 fragments into Xenopus laevis oocytes expressing SGLT1 or CNT1 and measuring the expressed uptake of α-methylglucoside or uridine 1 hour later, we identified a RS1 domain (RS1-Reg) containing multiple predicted phosphorylation sites that is responsible for this post-translational downregulation of SGLT1 and CNT1. Dependent on phosphorylation, RS1-Reg blocks the release of SGLT1-containing vesicles from the Golgi in a glucose-dependent manner or glucose-independent release of CNT1-containing vesicles. We showed that upregulation of SGLT1 in the small intestine after glucose ingestion is promoted by glucose-dependent disinhibition of the RS1-Reg-blocked exocytotic pathway of SGLT1 between meals. Mimicking phosphorylation of RS1-Reg, we obtained a RS1-Reg variant that downregulates SGLT1 in the brush-border membrane at high luminal glucose concentration. Because RS1 mediates short-term regulation of various transporters, we propose that the RS1-Reg-navigated transporter release from Golgi represents a basic regulatory mechanism of general importance, which implies the existence of receptor proteins that recognize different phosphorylated forms of RS1-Reg and of complex transporter-specific sorting in the trans-Golgi. RS1-Reg-derived peptides that downregulate SGLT1 at high intracellular glucose concentrations may be used for downregulation of glucose absorption in small intestine, which has been proposed as strategy for treatment of type 2 diabetes. PMID:26464324

  6. Abnormal oral glucose tolerance and glucose malabsorption after vagotomy and pyloroplasty. A tracer method for measuring glucose absorption rates

    SciTech Connect

    Radziuk, J.; Bondy, D.C.

    1982-11-01

    The mechanisms underlying the abnormal glucose tolerance in patients who had undergone vagotomy and pyloroplasty were investigated by measuring the rates of absorption of ingested glucose and the clearance rate of glucose using tracer methods. These methods are based on labeling a 100-g oral glucose load with (1-/sup 14/C)glucose and measuring glucose clearance using plasma levels of infused (3-/sup 3/H)glucose. The rate of appearance of both ingested and total glucose is then calculated continuously using a two-compartment model of glucose kinetics. It was found that about 30% of the ingested glucose (100 g) failed to appear in the systemic circulation. That this was due to malabsorption was confirmed using breath-hydrogen analysis. The absorption period is short (101 +/- 11 min) compared with normal values but the clearance of glucose is identical to that in control subjects, and it peaks 132 +/- 7 min after glucose loading. The peak plasma insulin values were more than four times higher in patients than in normal subjects, and this may afford an explanation of rates of glucose clearance that are inappropriate for the short absorption period. The combination of glucose malabsorption and this clearance pattern could yield the hypoglycemia that may be observed in patients after gastric surgery.

  7. Breakfast, blood glucose, and cognition.

    PubMed

    Benton, D; Parker, P Y

    1998-04-01

    This article compares the findings of three studies that explored the role of increased blood glucose in improving memory function for subjects who ate breakfast. An initial improvement in memory function for these subjects was found to correlate with blood glucose concentrations. In subsequent studies, morning fasting was found to adversely affect the ability to recall a word list and a story read aloud, as well as recall items while counting backwards. Failure to eat breakfast did not affect performance on an intelligence test. It was concluded that breakfast consumption preferentially influences tasks requiring aspects of memory. In the case of both word list recall and memory while counting backwards, the decline in performance associated with not eating breakfast was reversed by the consumption of a glucose-supplemented drink. Although a morning fast also affected the ability to recall a story read aloud, the glucose drink did not reverse this decline. It appears that breakfast consumption influences cognition via several mechanisms, including an increase in blood glucose. PMID:9537627

  8. Glucose metabolism and cardiac hypertrophy

    PubMed Central

    Kolwicz, Stephen C.; Tian, Rong

    2011-01-01

    The most notable change in the metabolic profile of hypertrophied hearts is an increased reliance on glucose with an overall reduced oxidative metabolism, i.e. a reappearance of the foetal metabolic pattern. In animal models, this change is attributed to the down-regulation of the transcriptional cascades promoting gene expression for fatty acid oxidation and mitochondrial oxidative phosphorylation in adult hearts. Impaired myocardial energetics in cardiac hypertrophy also triggers AMP-activated protein kinase (AMPK), leading to increased glucose uptake and glycolysis. Aside from increased reliance on glucose as an energy source, changes in other glucose metabolism pathways, e.g. the pentose phosphate pathway, the glucosamine biosynthesis pathway, and anaplerosis, are also noted in the hypertrophied hearts. Studies using transgenic mouse models and pharmacological compounds to mimic or counter the switch of substrate preference in cardiac hypertrophy have demonstrated that increased glucose metabolism in adult heart is not harmful and can be beneficial when it provides sufficient fuel for oxidative metabolism. However, improvement in the oxidative capacity and efficiency rather than the selection of the substrate is likely the ultimate goal for metabolic therapies. PMID:21502371

  9. Remote processing of pancreas can restore normal glucose homeostasis in autologous islet transplantation after traumatic whipple pancreatectomy: technical considerations.

    PubMed

    Khan, Aisha; Jindal, Rahul M; Shriver, Craig; Guy, Stephen R; Vertrees, Amy E; Wang, Xiaojing; Xu, Xiumin; Szust, Joel; Ricordi, Camillo

    2012-01-01

    An emergency autologous islet transplant after a traumatic Whipple operation and subsequent total pancreatectomy was performed for a 21-year-old patient who was wounded with multiple abdominal gunshot wounds. After Whipple pancreatectomy, the remnant pancreas (63.5 g), along with other damaged organs, was removed by the surgeons at Walter Reed Army Medical Center (WRAMC) and shipped to Diabetes Research Institute (DRI) for islet isolation. The pancreas was preserved in UW solution for 9.25 h prior to islet isolation. Upon arrival, the organ was visually inspected; the pancreatic head was missing, the rest of the pancreas was damaged and full of blood; the tail looked normal. A 16-gauge catheter was inserted into the main duct and directed towards tail of the pancreas after the dissection of main duct in the midbody of the pancreas. The pancreas was distended with collagenase solution (Roche MTF) through the catheter. During 10 min of intraductal delivery of enzyme, the gland was distended uniformly. No leakage of the solution was observed. The pancreas was transferred to a Ricordi chamber for automated mechanical and enzymatic digestion. Islets were purified using a COBE 2991 cell processor. Islet equivalents (IEQ; 221,250) of 40% purity and 90% viability were recovered during the isolation, which were shipped back to WRAMC and infused by intraportal injection into the patient. Immediate islet function was demonstrated by the rapid elevation of serum C peptide followed by insulin independence with near normal oral glucose tolerance test (OGTT) 1 and 2 months later. It is possible to restore near normal glucose tolerance with autologous islet transplantation after total pancreatectomy even with suboptimal number of islets while confirming that islets processed at a remote site are suitable for transplantation. PMID:21944862

  10. Combining glycosylated hemoglobin A1c and fasting plasma glucose for diagnosis of type 2 diabetes in Chinese adults

    PubMed Central

    2013-01-01

    Background Glycosylated hemoglobin A1c (HbA1c) has been applied to identify type 2 diabetes (T2DM) in the U.S. and European countries. It has not been used in China mainly due to lack of a standardized approach to measure HbA1c, short of knowledge about racial-specific standard and deficiency of an optimal cut-off point. Methods To evaluate combination of HbA1c and fasting plasma glucose (FPG) in diagnosing T2DM in Chinese adults, a multistage sampling cross-sectional study was conducted in Shanghai, China, in 2009. The FPG measurement, HbA1c assay, and oral glucose tolerance test (OGTT) were performed in 6,661 Chinese adults (3057 men, 3604 women) who had no prior history of diabetes to identify the unrecognized T2DM. Results A total of 454 participants were identified as T2DM based on the 1999 World Health Organization (WHO) diagnostic criteria. Of these patients, 239 were detected using an FPG ≥ 7.0 mmol/l and 141 were further identified using an HbA1c ≥ 43 mmol/mol (6.1%), achieving a sensitivity of 83.7% and a specificity of 89.3% for combining use of FPG and HbA1c. In subjects at high risk of diabetes, the combining use of FPG and HbA1c produced a higher sensitivity and an improved positive predictive value (PPV), and had a satisfactory specificity and negative predictive value (NPV). Conclusions The combining use of FPG and HbA1c is a potential screening and diagnosis approach for T2DM in Chinese adults, especially among those at high risk of the disease. PMID:24099651

  11. The Influence of Maternal Weight and Glucose Tolerance on Infant Birthweight in Latino Mother–Infant Pairs

    PubMed Central

    Kieffer, Edith C.; Tabaei, Bahman P.; Carman, Wendy J.; Nolan, George H.; Guzman, J. Ricardo; Herman, William H.

    2006-01-01

    Objectives. We assessed the influence of maternal anthropometric and metabolic variables, including glucose tolerance, on infant birthweight. Methods. In our prospective, population-based cohort study of 1041 Latino mother–infant pairs, we used standardized interviews, anthropometry, metabolic assays, and medical record reviews. We assessed relationships among maternal sociodemographic, prenatal care, anthropometric, and metabolic characteristics and birthweight with analysis of variance and bivariate and multivariate linear regression analyses. Results. Forty-two percent of women in this study entered pregnancy overweight or obese; at least 36% exceeded weight-gain recommendations. Twenty-seven percent of the women had at least some degree of glucose abnormality, including 6.8% who had gestational diabetes. Maternal multiparity, height, weight, weight gain, and 1-hour screening glucose levels were significant independent predictors of infant birthweight after adjustment for gestational age. Conclusion. Studies of birthweight should account for maternal glucose level. Given the increased risk of adverse maternal and infant outcomes associated with excessive maternal weight, weight gain, and glucose intolerance, and the high prevalence of these conditions and type 2 diabetes among Latinas, public health professionals have unique opportunities for prevention through prenatal and postpartum interventions. PMID:17077395

  12. Reengineered glucose oxidase for amperometric glucose determination in diabetes analytics.

    PubMed

    Arango Gutierrez, Erik; Mundhada, Hemanshu; Meier, Thomas; Duefel, Hartmut; Bocola, Marco; Schwaneberg, Ulrich

    2013-12-15

    Glucose oxidase is an oxidoreductase exhibiting a high β-D-glucose specificity and high stability which renders glucose oxidase well-suited for applications in diabetes care. Nevertheless, GOx activity is highly oxygen dependent which can lead to inaccuracies in amperometric β-D-glucose determinations. Therefore a directed evolution campaign with two rounds of random mutagenesis (SeSaM followed by epPCR), site saturation mutagenesis studies on individual positions, and one simultaneous site saturation library (OmniChange; 4 positions) was performed. A diabetes care well suited mediator (quinone diimine) was selected and the GOx variant (T30V I94V) served as starting point. For directed GOx evolution a microtiter plate detection system based on the quinone diimine mediator was developed and the well-known ABTS-assay was applied in microtiter plate format to validate oxygen independency of improved GOx variants. Two iterative rounds of random diversity generation and screening yielded to two subsets of amino acid positions which mainly improved activity (A173, A332) and oxygen independency (F414, V560). Simultaneous site saturation of all four positions with a reduced subset of amino acids using the OmniChange method yielded finally variant V7 with a 37-fold decreased oxygen dependency (mediator activity: 7.4 U/mg WT, 47.5 U/mg V7; oxygen activity: 172.3 U/mg WT, 30.1 U/mg V7). V7 is still highly β-D-glucose specific, highly active with the quinone diimine mediator and thermal resistance is retained (prerequisite for GOx coating of diabetes test stripes). The latter properties and V7's oxygen insensitivity make V7 a very promising candidate to replace standard GOx in diabetes care applications. PMID:23835222

  13. Effect of amiloride, or amiloride plus hydrochlorothiazide, versus hydrochlorothiazide on glucose tolerance and blood pressure (PATHWAY-3): a parallel-group, double-blind randomised phase 4 trial

    PubMed Central

    Brown, Morris J; Williams, Bryan; Morant, Steve V; Webb, David J; Caulfield, Mark J; Cruickshank, J Kennedy; Ford, Ian; McInnes, Gordon; Sever, Peter; Salsbury, Jackie; Mackenzie, Isla S; Padmanabhan, Sandosh; MacDonald, Thomas M

    2016-01-01

    Summary Background Potassium depletion by thiazide diuretics is associated with a rise in blood glucose. We assessed whether addition or substitution of a potassium-sparing diuretic, amiloride, to treatment with a thiazide can prevent glucose intolerance and improve blood pressure control. Methods We did a parallel-group, randomised, double-blind trial in 11 secondary and two primary care sites in the UK. Eligible patients were aged 18–80 years; had clinic systolic blood pressure of 140 mm Hg or higher and home systolic blood pressure of 130 mmHg or higher on permitted background drugs of angiotensin-converting enzyme inhibitors, angiotensin-receptor blockers, β blockers, calcium-channel blockers, or direct renin inhibitors (previously untreated patients were also eligible in specific circumstances); and had at least one component of the metabolic syndrome in addition to hypertension. Patients with known diabetes were excluded. Patients were randomly assigned (1:1:1) to 24 weeks of daily oral treatment with starting doses of 10 mg amiloride, 25 mg hydrochlorothiazide, or 5 mg amiloride plus 12·5 mg hydrochlorothiazide; all doses were doubled after 12 weeks. Random assignment was done via a central computer system. Both participants and investigators were masked to assignment. Our hierarchical primary endpoints, assessed on a modified intention-to-treat basis at 12 and 24 weeks, were the differences from baseline in blood glucose measured 2 h after a 75 g oral glucose tolerance test (OGTT), compared first between the hydrochlorothiazide and amiloride groups, and then between the hydrochlorothiazide and combination groups. A key secondary endpoint was change in home systolic blood pressure at 12 and 24 weeks. This trial is registered with ClinicalTrials.gov, number NCT00797862, and the MHRA, Eudract number 2009-010068-41, and is now complete. Findings Between Nov 18, 2009, and Dec 15, 2014, 145 patients were randomly assigned to amiloride, 146 to

  14. Microwave-Based Biosensor for Glucose Detection

    NASA Astrophysics Data System (ADS)

    Salim, N. S. M.; Khalid, K.; Yusof, N. A.

    2010-07-01

    In this project, microwave-based biosensor for glucose detection has been studied. The study is based on the dielectric properties changes at microwave frequency for glucose-enzyme reaction. Glucose interaction with glucose oxidase (GOD) produced gluconic acid and hydrogen peroxide. The reaction of the glucose solutions with an enzyme was carried out in 1:3 of glucose and enzyme respectively. The measurements were done using the Open Ended Coaxial Probe (OECP) coupled with computer controlled software automated network analyzer (ANA) with frequency range from 200MHz to 20GHz at room temperature (25 °C). The differences of enzyme and glucose-enzyme reaction were calculated and plotted. In the microwave interaction with the glucose-enzyme reaction, ionic conduction and dipole molecules was detected at 0.99GHz and 16.44GHz respectively based on changes of dielectric loss factor.

  15. Genetics Home Reference: glucose phosphate isomerase deficiency

    MedlinePlus

    ... Me Understand Genetics Home Health Conditions GPI deficiency glucose phosphate isomerase deficiency Enable Javascript to view the ... boxes. Download PDF Open All Close All Description Glucose phosphate isomerase (GPI) deficiency is an inherited disorder ...

  16. Glucose Effect in the Acute Porphyrias

    MedlinePlus

    ... You are here Home Diet and Nutrition The glucose effect in acute porphyrias The disorders Acute Intermittent ... are treated initially with the administration of carbohydrate/glucose. This therapy has its basis in the ability ...

  17. 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.

  18. Impact of Maternal Glucose and Gestational Weight Gain on Child Obesity over the First Decade of Life in Normal Birth Weight Infants.

    PubMed

    Hillier, Teresa A; Pedula, Kathryn L; Vesco, Kimberly K; Oshiro, Caryn E S; Ogasawara, Keith K

    2016-08-01

    Objective To determine, among children with normal birth weight, if maternal hyperglycemia and weight gain independently increase childhood obesity risk in a very large diverse population. Methods Study population was 24,141 individuals (mothers and their normal birth weight offspring, born 1995-2003) among a diverse population with universal GDM screening [50-g glucose-challenge test (GCT); 3 h. 100 g oral glucose tolerance test (OGTT) if GCT+]. Among the 13,037 full-term offspring with normal birth weight (2500-4000 g), annual measured height/weight was ascertained between ages 2 and 10 years to calculate gender-specific BMI-for-age percentiles using USA norms (1960-1995 standard). Results Among children who began life with normal birth weight, we found a significant trend for developing both childhood overweight (>85 %ile) and obesity (>95 %ile) during the first decade of life with both maternal hyperglycemia (normal GCT, GCT+ but no GDM, GDM) and excessive gestational weight gain [>40 pounds (18.1 kg)]; p < 0.0001 for both trends. These maternal glucose and/or weight gain effects to imprint for childhood obesity in the first decade remained after adjustment for potential confounders including maternal age, parity, as well as pre-pregnancy BMI. The attributable risk (%) for childhood obesity was 28.5 % (95 % CI 15.9-41.1) for GDM and 16.4 % (95 % CI 9.4-23.2) for excessive gestational weight gain. Conclusions for Practice Both maternal hyperglycemia and excessive weight gain have independent effects to increase childhood obesity risk. Future research should focus on prevention efforts during pregnancy as a potential window of opportunity to reduce childhood obesity. PMID:27154523

  19. Chromanol 293B, an inhibitor of KCNQ1 channels, enhances glucose-stimulated insulin secretion and increases glucagon-like peptide-1 level in mice.

    PubMed

    Liu, Lijie; Wang, Fanfan; Lu, Haiying; Ren, Xiaomei; Zou, Jihong

    2014-01-01

    Glucose-stimulated insulin secretion (GSIS) is a highly regulated process involving complex interaction of multiple factors. Potassium voltage-gated channel subfamily KQT member 1 (KCNQ1) is a susceptibility gene for type 2 diabetes (T2D) and the risk alleles of the KCNQ1 gene appear to be associated with impaired insulin secretion. The role of KCNQ1 channel in insulin secretion has been explored by previous work in clonal pancreatic β-cells but has yet to be investigated in the context of primary islets as well as intact animals. Genetic studies suggest that altered incretin glucagon-like peptide-1 (GLP-1) secretion might be a potential link between KCNQ1 variants and impaired insulin secretion, but this hypothesis has not been verified so far. In the current study, we examined KCNQ1 expression in pancreas and intestine from normal mice and then investigated the effects of chromanol 293B, a KCNQ1 channel inhibitor, on insulin secretion in vitro and in vivo. By double-immunofluorescence staining, KCNQ1 was detected in insulin-positive β-cells and GLP-1-positive L-cells. Administration of chromanol 293B enhanced GSIS in cultured islets and intact animals. Along with the potentiated insulin secretion during oral glucose tolerance tests (OGTT), plasma GLP-1 level after gastric glucose load was increased in 293B treated mice. These data not only provided new evidence for the participation of KCNQ1 in GSIS at the level of pancreatic islet and intact animal but also indicated the potential linking role of GLP-1 between KCNQ1 and insulin secretion. PMID:25437377

  20. 21 CFR 168.120 - Glucose sirup.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Glucose sirup. 168.120 Section 168.120 Food and... § 168.120 Glucose sirup. (a) Glucose sirup is the purified, concentrated, aqueous solution of nutritive... equivalent), expressed as D-glucose, is not less than 20.0 percent m/m calculated on a dry basis. (2)...

  1. 21 CFR 168.120 - Glucose sirup.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Glucose sirup. 168.120 Section 168.120 Food and... § 168.120 Glucose sirup. (a) Glucose sirup is the purified, concentrated, aqueous solution of nutritive... equivalent), expressed as D-glucose, is not less than 20.0 percent m/m calculated on a dry basis. (2)...

  2. A MEMS Dielectric Affinity Glucose Biosensor.

    PubMed

    Huang, Xian; Li, Siqi; Davis, Erin; Li, Dachao; Wang, Qian; Lin, Qiao

    2013-06-20

    Continuous glucose monitoring (CGM) sensors based on affinity detection are desirable for long-term and stable glucose management. However, most affinity sensors contain mechanical moving structures and complex design in sensor actuation and signal readout, limiting their reliability in subcutaneously implantable glucose detection. We have previously demonstrated a proof-of-concept dielectric glucose sensor that measured pre-mixed glucose-sensitive polymer solutions at various glucose concentrations. This sensor features simplicity in sensor design, and possesses high specificity and accuracy in glucose detection. However, lack of glucose diffusion passage, this device is unable to fulfill real-time in-vivo monitoring. As a major improvement to this device, we present in this paper a fully implantable MEMS dielectric affinity glucose biosensor that contains a perforated electrode embedded in a suspended diaphragm. This capacitive-based sensor contains no moving parts, and enables glucose diffusion and real-time monitoring. The experimental results indicate that this sensor can detect glucose solutions at physiological concentrations and possesses good reversibility and reliability. This sensor has a time constant to glucose concentration change at approximately 3 min, which is comparable to commercial systems. The sensor has potential applications in fully implantable CGM that require excellent long-term stability and reliability. PMID:24511215

  3. Glucose Transport Machinery Reconstituted in Cell Models

    PubMed Central

    Hansen, Jesper S.; Elbing, Karin; Thompson, James R.; Malmstadt, Noah

    2015-01-01

    Here we demonstrate the production of a functioning cell model by formation of giant vesicles reconstituted with the GLUT1 glucose transporter and a glucose oxidase and hydrogen peroxidase linked fluorescent reporter internally. Hence, a simplified artificial cell is formed that is able to take up glucose and process it. PMID:25562394

  4. Blood Glucose Levels and Problem Behavior

    ERIC Educational Resources Information Center

    Valdovinos, Maria G.; Weyand, David

    2006-01-01

    The relationship between varying blood glucose levels and problem behavior during daily scheduled activities was examined. The effects that varying blood glucose levels had on problem behavior during daily scheduled activities were examined. Prior research has shown that differing blood glucose levels can affect behavior and mood. Results of this…

  5. Glucose transport machinery reconstituted in cell models.

    PubMed

    Hansen, Jesper S; Elbing, Karin; Thompson, James R; Malmstadt, Noah; Lindkvist-Petersson, Karin

    2015-02-11

    Here we demonstrate the production of a functioning cell model by formation of giant vesicles reconstituted with the GLUT1 glucose transporter and a glucose oxidase and hydrogen peroxidase linked fluorescent reporter internally. Hence, a simplified artificial cell is formed that is able to take up glucose and process it. PMID:25562394

  6. 21 CFR 168.120 - Glucose sirup.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Glucose sirup. 168.120 Section 168.120 Food and... CONSUMPTION SWEETENERS AND TABLE SIRUPS Requirements for Specific Standardized Sweeteners and Table Sirups § 168.120 Glucose sirup. (a) Glucose sirup is the purified, concentrated, aqueous solution of...

  7. 21 CFR 168.120 - Glucose sirup.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Glucose sirup. 168.120 Section 168.120 Food and... CONSUMPTION SWEETENERS AND TABLE SIRUPS Requirements for Specific Standardized Sweeteners and Table Sirups § 168.120 Glucose sirup. (a) Glucose sirup is the purified, concentrated, aqueous solution of...

  8. 21 CFR 168.120 - Glucose sirup.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 2 2012-04-01 2012-04-01 false Glucose sirup. 168.120 Section 168.120 Food and... CONSUMPTION SWEETENERS AND TABLE SIRUPS Requirements for Specific Standardized Sweeteners and Table Sirups § 168.120 Glucose sirup. (a) Glucose sirup is the purified, concentrated, aqueous solution of...

  9. Estimation of liver glucose metabolism after refeeding

    SciTech Connect

    Rognstad, R.

    1987-05-01

    Refeeding or infusing glucose to rats fasted for 24 hr or more causes rapid liver glycogen synthesis, the carbon source now considered to be largely from gluconeogenesis. While substrate cycling between plasma glucose and liver glucose-6P is known to occur, this cycling has apparently been ignored when calculations are made of % contribution of direct and indirect pathways to liver glycogen synthesis, or when hepatic glucose output is calculated from glucose turnover minus the glucose infusion rate. They show that, isotopically, an estimate of the fluxes of liver glucokinase and glucose-6-phosphatase is required to quantitate sources of carbon for liver glycogen synthesis, and to measure hepatic glucose output (or uptake). They propose a method to estimate these fluxes, involving a short infusion of a /sup 14/C labelled gluconeogenic precursor plus (6T)glucose, with determination of isotopic yields in liver glycogen and total glucose. Given also the rate of liver glycogen synthesis, this procedure permits the estimation of net gluconeogenesis and hepatic glucose output or uptake. Also, in vitro evidence against the notion of a drastic zonation of liver carbohydrate metabolism is presented, e.g. raising the glucose concentration from 10 to 25 mM increases the /sup 14/C yield from H/sup 14/CO/sub 3//sup -/ in lactate, with the increased pyruvate kinase flux and decreased gluconeogenesis occurring in the same cell type, not opposing pathways in different hepatocyte types (as has been postulated by some to occur in vivo after refeeding.

  10. Dexamethasone increases glucose cycling, but not glucose production, in healthy subjects

    SciTech Connect

    Wajngot, A.; Khan, A.; Giacca, A.; Vranic, M.; Efendic, S. )

    1990-11-01

    We established that measurement of glucose fluxes through glucose-6-phosphatase (G-6-Pase; hepatic total glucose output, HTGO), glucose cycling (GC), and glucose production (HGP), reveals early diabetogenic changes in liver metabolism. To elucidate the mechanism of the diabetogenic effect of glucocorticoids, we treated eight healthy subjects with oral dexamethasone (DEX; 15 mg over 48 h) and measured HTGO with (2-3H)glucose and HGP with (6-3H)glucose postabsorptively and during a 2-h glucose infusion (11.1 mumol.kg-1.min-1). (2-3H)- minus (6-3H)glucose equals GC. DEX significantly increased plasma glucose, insulin, C peptide, and HTGO, while HGP was unchanged. In controls and DEX, glucose infusion suppressed HTGO (82 vs. 78%) and HGP (87 vs. 91%). DEX increased GC postabsorptively (three-fold) P less than 0.005 and during glucose infusion (P less than 0.05) but decreased metabolic clearance and glucose uptake (Rd), which eventually normalized, however. Because DEX increased HTGO (G-6-Pase) and not HGP (glycogenolysis + gluconeogenesis), we assume that DEX increases HTGO and GC in humans by activating G-6-Pase directly, rather than by expanding the glucose 6-phosphate pool. Hyperglycemia caused by peripheral effects of DEX can also contribute to an increase in GC by activating glucokinase. Therefore, measurement of glucose fluxes through G-6-Pase and GC revealed significant early effects of DEX on hepatic glucose metabolism, which are not yet reflected in HGP.

  11. Comparison of single and combination diuretics on glucose tolerance (PATHWAY-3): protocol for a randomised double-blind trial in patients with essential hypertension

    PubMed Central

    Brown, Morris J; Williams, Bryan; MacDonald, Thomas M; Caulfield, Mark; Cruickshank, J Kennedy; McInnes, Gordon; Sever, Peter; Webb, David J; Salsbury, Jackie; Morant, Steve; Ford, Ian

    2015-01-01

    Introduction Thiazide diuretics are associated with increased risk of diabetes mellitus. This risk may arise from K+-depletion. We hypothesised that a K+-sparing diuretic will improve glucose tolerance, and that combination of low-dose thiazide with K+-sparing diuretic will improve both blood pressure reduction and glucose tolerance, compared to a high-dose thiazide. Methods and analysis This is a parallel-group, randomised, double-blind, multicentre trial, comparing hydrochlorothiazide 25–50 mg, amiloride 10–20 mg and combination of both diuretics at half these doses. A single-blind placebo run-in of 1 month is followed by 24 weeks of blinded active treatment. There is forced dose-doubling after 3 months. The Primary end point is the blood glucose 2 h after oral ingestion of a 75 g glucose drink (OGTT), following overnight fasting. The primary outcome is the difference between 2 h glucose at weeks 0, 12 and 24. Secondary outcomes include the changes in home systolic blood pressure (BP) and glycated haemoglobin and prediction of response by baseline plasma renin. Eligibility criteria are: age 18–79, systolic BP on permitted background treatment ≥140 mm Hg and home BP ≥130 mm Hg and one component of the metabolic syndrome additional to hypertension. Principal exclusions are diabetes, estimated-glomerular filtration rate <45 mL/min, abnormal plasma K+, clinic SBP >200 mm Hg or DBP >120 mm Hg (box 2). The sample size calculation indicates that 486 patients will give 80% power at α=0.01 to detect a difference in means of 1 mmol/L (SD=2.2) between 2 h glucose on hydrochlorothiazide and comparators. Ethics and dissemination PATHWAY-3 was approved by Cambridge South Ethics Committee, number 09/H035/19. The trial results will be published in a peer-reviewed scientific journal. Trial registration numbers Eudract number 2009-010068-41 and clinical trials registration number: NCT02351973. PMID:26253567

  12. Non-invasive glucose monitor

    NASA Technical Reports Server (NTRS)

    Lambert, James L. (Inventor); Borchert, Mark S. (Inventor)

    2001-01-01

    A non-invasive method for determining blood level of an analyte of interest, such as glucose, comprises: generating an excitation laser beam (e.g., at a wavelength of 700 to 900 nanometers); focusing the excitation laser beam into the anterior chamber of an eye of the subject so that aqueous humor in the anterior chamber is illuminated; detecting (preferably confocally detecting) a Raman spectrum from the illuminated aqueous humor; and then determining the blood glucose level (or the level of another analyte of interest) for the subject from the Raman spectrum. Preferably, the detecting step is followed by the step of subtracting a confounding fluorescence spectrum from the Raman spectrum to produce a difference spectrum; and determining the blood level of the analyte of interest for the subject from that difference spectrum, preferably using linear or nonlinear multivariate analysis such as partial least squares analysis. Apparatus for carrying out the foregoing method is also disclosed.

  13. Extraction of Silver by Glucose.

    PubMed

    Baksi, Ananya; Gandi, Mounika; Chaudhari, Swathi; Bag, Soumabha; Gupta, Soujit Sen; Pradeep, Thalappil

    2016-06-27

    Unprecedented silver ion leaching, in the range of 0.7 ppm was seen when metallic silver was heated in water at 70 °C in presence of simple carbohydrates, such as glucose, making it a green method of silver extraction. Extraction was facilitated by the presence of anions, such as carbonate and phosphate. Studies confirm a two-step mechanism of silver release, first forming silver ions at the metal surface and later complexation of ionic silver with glucose; such complexes have been detected by mass spectrometry. Extraction leads to microscopic roughening of the surface making it Raman active with an enhancement factor of 5×10(8) . PMID:27119514

  14. Reimbursement for Continuous Glucose Monitoring

    PubMed Central

    DeVries, J. Hans

    2016-01-01

    Abstract Continuous glucose monitoring (CGM) systems have been available for more than 15 years by now. However, market uptake is relatively low in most countries; in other words, relatively few patients with diabetes use CGM systems regularly. One major reason for the reluctance of patients to use CGM systems is the costs associated (i.e., in most countries no reimbursement is provided by the health insurance companies). In case reimbursement is in place, like in the United States, only certain patient groups get reimbursement that fulfills strict indications. This situation is somewhat surprising in view of the mounting evidence for benefits of CGM usage from clinical trials: most meta-analyses of these trials consistently show a clinically relevant improvement of glucose control associated with a reduction in hypoglycemic events. More recent trials with CGM systems with an improved CGM technology showed even more impressive benefits, especially if CGM systems are used in different combinations with an insulin pump (e.g., with automated bolus calculators and low glucose suspend features). Nevertheless, sufficient evidence is not available for all patient groups, and more data on cost–efficacy are needed. In addition, good data from real-world studies/registers documenting the benefits of CGM usage under daily life conditions would be of help to convince healthcare systems to cover the costs of CGM systems. In view of the ongoing improvements in established needle-type CGM systems, the fact that new CGM technology will come to the market soon (e.g., implantable sensors), that CGM-like systems are quite successfully at least in certain markets (like the flash glucose monitoring systems), and that the first artificial pancreas systems will come to the market in the next few years, there is a need to make sure that this major improvement in diabetes therapy becomes more widely available for patients with diabetes, for which better reimbursement is essential. PMID

  15. Reimbursement for Continuous Glucose Monitoring.

    PubMed

    Heinemann, Lutz; DeVries, J Hans

    2016-02-01

    Continuous glucose monitoring (CGM) systems have been available for more than 15 years by now. However, market uptake is relatively low in most countries; in other words, relatively few patients with diabetes use CGM systems regularly. One major reason for the reluctance of patients to use CGM systems is the costs associated (i.e., in most countries no reimbursement is provided by the health insurance companies). In case reimbursement is in place, like in the United States, only certain patient groups get reimbursement that fulfills strict indications. This situation is somewhat surprising in view of the mounting evidence for benefits of CGM usage from clinical trials: most meta-analyses of these trials consistently show a clinically relevant improvement of glucose control associated with a reduction in hypoglycemic events. More recent trials with CGM systems with an improved CGM technology showed even more impressive benefits, especially if CGM systems are used in different combinations with an insulin pump (e.g., with automated bolus calculators and low glucose suspend features). Nevertheless, sufficient evidence is not available for all patient groups, and more data on cost-efficacy are needed. In addition, good data from real-world studies/registers documenting the benefits of CGM usage under daily life conditions would be of help to convince healthcare systems to cover the costs of CGM systems. In view of the ongoing improvements in established needle-type CGM systems, the fact that new CGM technology will come to the market soon (e.g., implantable sensors), that CGM-like systems are quite successfully at least in certain markets (like the flash glucose monitoring systems), and that the first artificial pancreas systems will come to the market in the next few years, there is a need to make sure that this major improvement in diabetes therapy becomes more widely available for patients with diabetes, for which better reimbursement is essential. PMID:26784130

  16. Central acylated ghrelin improves memory function and hippocampal AMPK activation and partly reverses the impairment of energy and glucose metabolism in rats infused with β-amyloid.

    PubMed

    Kang, Suna; Moon, Na Rang; Kim, Da Sol; Kim, Sung Hoon; Park, Sunmin

    2015-09-01

    Ghrelin is a gastric hormone released during the fasting state that targets the hypothalamus where it induces hunger; however, emerging evidence suggests it may also affect memory function. We examined the effect of central acylated-ghrelin and DES-acetylated ghrelin (native ghrelin) on memory function and glucose metabolism in an experimentally induced Alzheimer's disease (AD) rat model. AD rats were divided into 3 groups and Non-AD rats were used as a normal-control group. Each rat in the AD groups had intracerebroventricular (ICV) infusion of β-amyloid (25-35; 16.8nmol/day) into the lateral ventricle for 3 days, and then the pumps were changed to infuse either acylated-ghrelin (0.2nmol/h; AD-G), DES-acylated ghrelin (0.2nmol/h; AD-DES-G), or saline (control; AD-C) for 3 weeks. The Non-AD group had ICV infusion of β-amyloid (35-25) which does not deposit in the hippocampus. During the next 3 weeks memory function, food intake, body weight gain, body fat composition, and glucose metabolism were measured. AD-C exhibited greater β-amyloid deposition compared to Non-AD-C, and AD-G suppressed the increased β-amyloid deposition and potentiated the phosphorylation AMPK. In addition, AD-G increased the phosphorylation GSK and decreased the phosphorylation of Tau in comparison to AD-C and AD-DES-G. Cognitive function, measured by passive avoidance and water maze tests, was much lower in AD-C than Non-AD-C whereas AD-G but not AD-DES-G prevented the decrease (p<0.021). Body weight gain was lower in AD-C group than Non-AD-C group without changing epididymal fat mass. AD-G reversed the decrease in body weight which was due to increased energy intake and decreased energy expenditure. The AD-G group exhibited a decrease in the second part of serum glucose levels during an oral glucose tolerance test (OGTT) compared to the AD-C and AD-DES-G group (p<0.009). However, area under the curve of insulin during the first part of OGTT was higher in AD-DES-G than other groups

  17. Glucose metabolism in diabetic blood vessels

    SciTech Connect

    Brown, B.J.; Crass, M.F. III

    1986-03-05

    Since glycolysis appears to be coupled to active ion transport in vascular smooth muscle, alterations in glucose metabolism may contribute to cellular dysfunction and angiopathy in diabetes. Uptake and utilization of glucose were studied in perfused blood vessels in which pulsatile flow and perfusion pressure were similar to those measured directly in vivo. Thoracic aortae isolated from 8-wk alloxan diabetic (D) and nondiabetic control rabbits were cannulated, tethered, and perfused with oxygenated buffer containing 7 or 25 mM glucose and tracer amounts of glucose-U/sup -14/ C. Norepinephrine (NE) (10/sup -6/ M) and/or insulin (I) (150 ..mu..U/ml) and albumin (0.2%) were added. NE-induced tension development increased glucose uptake 39% and /sup 14/CO/sub 2/ and lactate production 2.3-fold. With 7 mM glucose, marked decreases in glucose uptake (74%), /sup 14/CO/sub 2/ (68%), lactate (30%), total tissue glycogen (75%), and tissue phospholipids (70%) were observed in D. Addition of I or elevation of exogenous glucose to 25 mM normalized glucose uptake, but had differential effects on the pattern of substrate utilization. Thus, in D, there was a marked depression of vascular glucose metabolism that was partially reversed by addition of low concentrations of insulin or D levels of glucose.

  18. Glucose kinetics in infants of diabetic mothers

    SciTech Connect

    Cowett, R.M.; Susa, J.B.; Giletti, B.; Oh, W.; Schwartz, R.

    1983-08-01

    Glucose kinetic studies were performed to define the glucose turnover rate with 78% enriched D-(U-13C) glucose by the prime constant infusion technique at less than or equal to 6 hours of age in nine infants of diabetic mothers (four insulin-dependent and five chemical diabetic patients) at term. Five normal infants were studied as control subjects. All infants received 0.9% saline intravenously during the study with the tracer. Fasting plasma glucose, insulin, and glucose13/12C ratios were measured during the steady state, and the glucose turnover rate was derived. The average plasma glucose concentration was similar during the steady state in the infants of the diabetic mothers and in the control infants, and the glucose turnover rate was not significantly different among the groups: 2.3 +/- 0.6 mg . kg-1 min-1 in infants of insulin-dependent diabetic patients; 2.4 +/- 0.4 mg . kg-1 min-1 in infants of chemical diabetic patients; and 3.2 +/- 0.3 mg . kg-1 min-1 in the control subjects. Good control of maternal diabetes evidenced by the normal maternal hemoglobin A1c and plasma glucose concentration at delivery and cord plasma glucose concentration resulted in glucose kinetic values in the infants of diabetic mothers that were indistinguishable from those of control subjects. The data further support the importance of good control of the diabetic state in the pregnant woman to minimize or prevent neonatal hypoglycemia.

  19. What is a normal blood glucose?

    PubMed

    Güemes, Maria; Rahman, Sofia A; Hussain, Khalid

    2016-06-01

    Glucose is the key metabolic substrate for tissue energy production. In the perinatal period the mother supplies glucose to the fetus and for most of the gestational period the normal lower limit of fetal glucose concentration is around 3 mmol/L. Just after birth, for the first few hours of life in a normal term neonate appropriate for gestational age, blood glucose levels can range between 1.4 mmol/L and 6.2 mmol/L but by about 72 h of age fasting blood glucose levels reach normal infant, child and adult values (3.5-5.5 mmol/L). Normal blood glucose levels are maintained within this narrow range by factors which control glucose production and glucose utilisation. The key hormones which regulate glucose homoeostasis include insulin, glucagon, epinephrine, norepinephrine, cortisol and growth hormone. Pathological states that affect either glucose production or utilisation will lead to hypoglycaemia. Although hypoglycaemia is a common biochemical finding in children (especially in the newborn) it is not possible to define by a single (or a range of) blood glucose value/s. It can be defined as the concentration of glucose in the blood or plasma at which the individual demonstrates a unique response to the abnormal milieu caused by the inadequate delivery of glucose to a target organ (eg, the brain). Hypoglycaemia should therefore be considered as a continuum and the blood glucose level should be interpreted within the clinical scenario and with respect to the counter-regulatory hormonal responses and intermediate metabolites. PMID:26369574

  20. Genetic Variations in the Kir6.2 Subunit (KCNJ11) of Pancreatic ATP-Sensitive Potassium Channel Gene Are Associated with Insulin Response to Glucose Loading and Early Onset of Type 2 Diabetes in Childhood and Adolescence in Taiwan.

    PubMed

    Jiang, Yi-Der; Chuang, Lee-Ming; Pei, Dee; Lee, Yann-Jinn; Wei, Jun-Nan; Sung, Fung-Chang; Chang, Tien-Jyun

    2014-01-01

    To investigate the role of E23K polymorphism of the KCNJ11 gene on early onset of type 2 diabetes in school-aged children/adolescents in Taiwan, we recruited 38 subjects with type 2 diabetes (ages 18.6 ± 6.6 years; body mass index percentiles 83.3 ± 15.4) and 69 normal controls (ages 17.3 ± 3.8 years; body mass index percentiles 56.7 ± 29.0) from a national surveillance for childhood/adolescent diabetes in Taiwan. We searched for the E23K polymorphism of the KCNJ11 gene. We found that type 2 diabetic subjects had higher carrier rate of E23K polymorphism of KCNJ11 gene than control subjects (P = 0.044). After adjusting for age, gender, body mass index percentiles, and fasting plasma insulin, the E23K polymorphism contributed to an increased risk for type 2 diabetes (P = 0.047). K23-allele-containing genotypes conferring increased plasma insulin level during OGTT in normal subjects. However, the diabetic subjects with the K23-allele-containing genotypes had lower fasting plasma insulin levels after adjustment of age and BMI percentiles. In conclusion, the E23K variant of the KCNJ11 gene conferred higher susceptibility to type 2 diabetes in children/adolescents. Furthermore, in normal glucose-tolerant children/adolescents, K23 allele carriers had a higher insulin response to oral glucose loading. PMID:25309595

  1. The Usefulness of the Glycosylated Hemoglobin Level for the Diagnosis of Gestational Diabetes Mellitus in the Korean Population

    PubMed Central

    Ryu, Ah Jeong; Moon, Hyuk Jin; Na, Joo Ok; Kim, Sang Jin; Mo, Sang Il; Byun, Jeong Ran

    2015-01-01

    Background An oral glucose tolerance test (OGTT) is the current method used for screening and diagnosis of gestational diabetes mellitus (GDM). OGTT is a relatively complicated procedure and is expensive. Thus, new strategies that do not require fasting or more than a single blood draw may improve the diagnosis of GDM and increase the rate of GDM testing. We investigated the utility of monitoring glycosylated hemoglobin (HbA1c) levels for the diagnosis of GDM. Methods The data from 992 pregnant women with estimated gestational ages ranging from 24 to 28 weeks were retrospectively reviewed. There were 367 women with plasma glucose levels ≥140 mg/dL 1 hour after a 50-g OGTT. GDM was diagnosed according to the Carpenter-Coustan criteria for a 3-hour 100 g OGTT. A HbA1c assessment was performed at the same time. Results We enrolled 343 women in this study, and there were 109 women with GDM. The area under the curve the receiver operating characteristic curve for HbA1c detection of GDM was 0.852 (95% confidence interval, 0.808 to 0.897). A HbA1c cutoff value ≥5.35% had maximal points on the Youden index (0.581). The sensitivity was 87.2% and the specificity was 70.9% for diagnosing GDM. A threshold value ≥5.35% indicated that 163 patients had GDM and that 68 (41.7%) were false positive. The positive predictive value was 58.3% at this threshold value. Conclusion Despite substantial progress in methodology, HbA1c values cannot replace OGTT for the diagnosis of GDM. PMID:26616593

  2. A MEMS differential viscometric sensor for affinity glucose detection in continuous glucose monitoring.

    PubMed

    Huang, Xian; Li, Siqi; Davis, Erin; Leduc, Charles; Ravussin, Yann; Cai, Haogang; Song, Bing; Li, Dachao; Accili, Domenico; Leibel, Rudolph; Wang, Qian; Lin, Qiao

    2013-05-01

    Micromachined viscometric affinity glucose sensors have been previously demonstrated using vibrational cantilever and diaphragm. These devices featured a single glucose detection module that determines glucose concentrations through viscosity changes of glucose-sensitive polymer solutions. However, fluctuations in temperature and other environmental parameters might potentially affect the stability and reliability of these devices, creating complexity in their applications in subcutaneously implanted continuous glucose monitoring (CGM). To address these issues, we present a MEMS differential sensor that can effectively reject environmental disturbances while allowing accurate glucose detection. The sensor consists of two magnetically driven vibrating diaphragms situated inside microchambers filled with a boronic-acid based glucose-sensing solution and a reference solution insensitive to glucose. Glucose concentrations can be accurately determined by characteristics of the diaphragm vibration through differential capacitive detection. Our in-vitro and preliminary in-vivo experimental data demonstrate the potential of this sensor for highly stable subcutaneous CGM applications. PMID:23956499

  3. A MEMS differential viscometric sensor for affinity glucose detection in continuous glucose monitoring

    NASA Astrophysics Data System (ADS)

    Huang, Xian; Li, Siqi; Davis, Erin; Leduc, Charles; Ravussin, Yann; Cai, Haogang; Song, Bing; Li, Dachao; Accili, Domenico; Leibel, Rudolph; Wang, Qian; Lin, Qiao

    2013-05-01

    Micromachined viscometric affinity glucose sensors have been previously demonstrated using vibrational cantilever and diaphragm. These devices featured a single glucose detection module that determines glucose concentrations through viscosity changes of glucose-sensitive polymer solutions. However, fluctuations in temperature and other environmental parameters might potentially affect the stability and reliability of these devices, creating complexity in their applications in subcutaneously implanted continuous glucose monitoring (CGM). To address these issues, we present a MEMS differential sensor that can effectively reject environmental disturbances while allowing accurate glucose detection. The sensor consists of two magnetically driven vibrating diaphragms situated inside microchambers filled with a boronic-acid based glucose-sensing solution and a reference solution insensitive to glucose. Glucose concentrations can be accurately determined by characteristics of the diaphragm vibration through differential capacitive detection. Our in vitro and preliminary in vivo experimental data demonstrate the potential of this sensor for highly stable subcutaneous CGM applications.

  4. A MEMS differential viscometric sensor for affinity glucose detection in continuous glucose monitoring

    PubMed Central

    Huang, Xian; Li, Siqi; Davis, Erin; Leduc, Charles; Ravussin, Yann; Cai, Haogang; Song, Bing; Li, Dachao; Accili, Domenico; Leibel, Rudolph; Wang, Qian; Lin, Qiao

    2013-01-01

    Micromachined viscometric affinity glucose sensors have been previously demonstrated using vibrational cantilever and diaphragm. These devices featured a single glucose detection module that determines glucose concentrations through viscosity changes of glucose-sensitive polymer solutions. However, fluctuations in temperature and other environmental parameters might potentially affect the stability and reliability of these devices, creating complexity in their applications in subcutaneously implanted continuous glucose monitoring (CGM). To address these issues, we present a MEMS differential sensor that can effectively reject environmental disturbances while allowing accurate glucose detection. The sensor consists of two magnetically driven vibrating diaphragms situated inside microchambers filled with a boronic-acid based glucose-sensing solution and a reference solution insensitive to glucose. Glucose concentrations can be accurately determined by characteristics of the diaphragm vibration through differential capacitive detection. Our in-vitro and preliminary in-vivo experimental data demonstrate the potential of this sensor for highly stable subcutaneous CGM applications. PMID:23956499

  5. Continuous Glucose Monitoring in Patients with Abnormal Glucose Tolerance during Pregnancy: A Case Series.

    PubMed

    Tonoike, Mie; Kishimoto, Miyako; Yamamoto, Mayumi; Yano, Tetsu; Noda, Mitsuhiko

    2016-01-01

    Abnormal glucose tolerance during pregnancy is associated with perinatal complications. We used continuous glucose monitoring (CGM) in pregnant women with glucose intolerance to achieve better glycemic control and to evaluate the maternal glucose fluctuations. We also used CGM in women without glucose intolerance (the control cases). Furthermore, the standard deviation (SD) and mean amplitude of glycemic excursions (MAGE) were calculated for each case. For the control cases, the glucose levels were tightly controlled within a very narrow range; however, the SD and MAGE values in pregnant women with glucose intolerance were relativity high, suggesting postprandial hyperglycemia. Our results demonstrate that pregnant women with glucose intolerance exhibited greater glucose fluctuations compared with the control cases. The use of CGM may help to improve our understanding of glycemic patterns and may have beneficial effects on perinatal glycemic control, such as the detection of postprandial hyperglycemia in pregnant women. PMID:26949348

  6. Continuous Glucose Monitoring in Patients with Abnormal Glucose Tolerance during Pregnancy: A Case Series

    PubMed Central

    Tonoike, Mie; Kishimoto, Miyako; Yamamoto, Mayumi; Yano, Tetsu; Noda, Mitsuhiko

    2016-01-01

    Abnormal glucose tolerance during pregnancy is associated with perinatal complications. We used continuous glucose monitoring (CGM) in pregnant women with glucose intolerance to achieve better glycemic control and to evaluate the maternal glucose fluctuations. We also used CGM in women without glucose intolerance (the control cases). Furthermore, the standard deviation (SD) and mean amplitude of glycemic excursions (MAGE) were calculated for each case. For the control cases, the glucose levels were tightly controlled within a very narrow range; however, the SD and MAGE values in pregnant women with glucose intolerance were relativity high, suggesting postprandial hyperglycemia. Our results demonstrate that pregnant women with glucose intolerance exhibited greater glucose fluctuations compared with the control cases. The use of CGM may help to improve our understanding of glycemic patterns and may have beneficial effects on perinatal glycemic control, such as the detection of postprandial hyperglycemia in pregnant women. PMID:26949348

  7. Glucose transport in brain - effect of inflammation.

    PubMed

    Jurcovicova, J

    2014-01-01

    Glucose is transported across the cell membrane by specific saturable transport system, which includes two types of glucose transporters: 1) sodium dependent glucose transporters (SGLTs) which transport glucose against its concentration gradient and 2) sodium independent glucose transporters (GLUTs), which transport glucose by facilitative diffusion in its concentration gradient. In the brain, both types of transporters are present with different function, affinity, capacity, and tissue distribution. GLUT1 occurs in brain in two isoforms. The more glycosylated GLUT1 is produced in brain microvasculature and ensures glucose transport across the blood brain barrier (BBB). The less glycosylated form is localized in astrocytic end-feet and cell bodies and is not present in axons, neuronal synapses or microglia. Glucose transported to astrocytes by GLUT1 is metabolized to lactate serving to neurons as energy source. Proinflammatory cytokine interleukin (IL)-1β upregulates GLUT1 in endothelial cells and astrocytes, whereas it induces neuronal death in neuronal cell culture. GLUT2 is present in hypothalamic neurons and serves as a glucose sensor in regulation of food intake. In neurons of the hippocampus, GLUT2 is supposed to regulate synaptic activity and neurotransmitter release. GLUT3 is the most abundant glucose transporter in the brain having five times higher transport capacity than GLUT1. It is present in neuropil, mostly in axons and dendrites. Its density and distribution correlate well with the local cerebral glucose demands. GLUT5 is predominantly fructose transporter. In brain, GLUT5 is the only hexose transporter in microglia, whose regulation is not yet clear. It is not present in neurons. GLUT4 and GLUT8 are insulin-regulated glucose transporters in neuronal cell bodies in the cortex and cerebellum, but mainly in the hippocampus and amygdala, where they maintain hippocampus-dependent cognitive functions. Insulin translocates GLUT4 from cytosol to plasma

  8. Coping with an exogenous glucose overload: glucose kinetics of rainbow trout during graded swimming.

    PubMed

    Choi, Kevin; Weber, Jean-Michel

    2016-03-15

    This study examines how chronically hyperglycemic rainbow trout modulate glucose kinetics in response to graded exercise up to critical swimming speed (Ucrit), with or without exogenous glucose supply. Our goals were 1) to quantify the rates of hepatic glucose production (Ra glucose) and disposal (Rd glucose) during graded swimming, 2) to determine how exogenous glucose affects the changes in glucose fluxes caused by exercise, and 3) to establish whether exogenous glucose modifies Ucrit or the cost of transport. Results show that graded swimming causes no change in Ra and Rd glucose at speeds below 2.5 body lengths per second (BL/s), but that glucose fluxes may be stimulated at the highest speeds. Excellent glucoregulation is also achieved at all exercise intensities. When exogenous glucose is supplied during exercise, trout suppress hepatic production from 16.4 ± 1.6 to 4.1 ± 1.7 μmol·kg(-1)·min(-1) and boost glucose disposal to 40.1 ± 13 μmol·kg(-1)·min(-1). These responses limit the effects of exogenous glucose to a 2.5-fold increase in glycemia, whereas fish showing no modulation of fluxes would reach dangerous levels of 114 mM of blood glucose. Exogenous glucose reduces metabolic rate by 16% and, therefore, causes total cost of transport to decrease accordingly. High glucose availability does not improve Ucrit because the fish are unable to take advantage of this extra fuel during maximal exercise and rely on tissue glycogen instead. In conclusion, trout have a remarkable ability to adjust glucose fluxes that allows them to cope with the cumulative stresses of a glucose overload and graded exercise. PMID:26719305

  9. FRET-based glucose monitoring for bioprocessing

    NASA Astrophysics Data System (ADS)

    Bartolome, Amelita; Smalls-Mantey, Lauren; Lin, Debora; Rao, Govind; Tolosa, Leah

    2006-02-01

    The glucose-mediated conformational changes in the glucose binding protein (GBP) have been exploited in the development of fluorescence based glucose sensors. The fluorescence response is generated by a polarity sensitive dye attached to a specific site. Such fluorescent sensors respond to submicromolar glucose at diffusion-controlled rates mimicking the wild type. However, such sensors have been limited to in vitro glucose sensing because of the preliminary dye-labeling step. In the study described here, the dye-labeling step is omitted by genetically encoding the GBP with two green fluorescent mutants namely, the green fluorescent protein (GFP) and the yellow fluorescent protein (YFP) in the N- and C-terminal ends, respectively. These two GFP mutants comprise a fluorescence resonance energy transfer (FRET) donor and acceptor pair. Thus, when glucose binds with GBP, the conformational changes affect the FRET efficiency yielding a dose-dependent response. A potential application for this FRET-based glucose biosensor is online glucose sensing in bioprocessing and cell culture. This was demonstrated by the measurement of glucose consumption in yeast fermentation. Further development of this system should yield in vivo measurement of glucose in bioprocesses.

  10. Regulation of Blood Glucose by Hypothalamic Pyruvate Metabolism

    NASA Astrophysics Data System (ADS)

    Lam, Tony K. T.; Gutierrez-Juarez, Roger; Pocai, Alessandro; Rossetti, Luciano

    2005-08-01

    The brain keenly depends on glucose for energy, and mammalians have redundant systems to control glucose production. An increase in circulating glucose inhibits glucose production in the liver, but this negative feedback is impaired in type 2 diabetes. Here we report that a primary increase in hypothalamic glucose levels lowers blood glucose through inhibition of glucose production in rats. The effect of glucose requires its conversion to lactate followed by stimulation of pyruvate metabolism, which leads to activation of adenosine triphosphate (ATP)-sensitive potassium channels. Thus, interventions designed to enhance the hypothalamic sensing of glucose may improve glucose homeostasis in diabetes.

  11. [Glucose metabolic changes in stress].

    PubMed

    Foia, L; Costuleanu, N; Trandafirescu, M; Saila, V; Pavel, M

    1999-01-01

    Provision of a better understanding of the pathogenic pathways underlying injured sugar metabolism during stress should ideally translate into a more rational approach to the provision of nutritional support. Patients with burns, trauma, severe injuries or infections commonly develop a hypermetabolic state that is associated with several changes in carbohydrate metabolism. The hypermetabolic state is induced either by the area of injury and by organs involved in the immunologic response to stress; further it determines a glycemic milieu which will be directed toward satisfaction of the requirements for glucose as an energy support. PMID:10756928

  12. Hepatic glucose and lipid metabolism.

    PubMed

    Jones, John G

    2016-06-01

    The liver has a central role in the regulation of systemic glucose and lipid fluxes during feeding and fasting and also relies on these substrates for its own energy needs. These parallel requirements are met by coordinated control of carbohydrate and lipid fluxes into and out of the Krebs cycle, which is highly tuned to nutrient availability and heavily regulated by insulin and glucagon. During progression of type 2 diabetes, hepatic carbohydrate and lipid biosynthesis fluxes become elevated, thus contributing to hyperglycaemia and hypertriacylglycerolaemia. Over this interval there are also significant fluctuations in hepatic energy state. To date, it is not known to what extent abnormal glucose and lipid fluxes are causally linked to altered energy states. Recent evidence that the glucose-lowering effects of metformin appear to be mediated by attenuation of hepatic energy generation places an additional spotlight on the interdependence of hepatic biosynthetic and oxidative fluxes. The transition from fasting to feeding results in a significant re-direction of hepatic glucose and lipid fluxes and may also incur a temporary hepatic energy deficit. At present, it is not known to what extent these variables are additionally modified by type 2 diabetes and/or non-alcoholic fatty liver disease. Thus, there is a compelling need to measure fluxes through oxidative, gluconeogenic and lipogenic pathways and determine their relationship with hepatic energy state in both fasting and fed conditions. New magnetic resonance-based technologies allow these variables to be non-invasively studied in animal models and humans. This review summarises a presentation given at the symposium entitled 'The liver in focus' at the 2015 annual meeting of the EASD. It is accompanied by two other reviews on topics from this symposium (by Kenneth Cusi, DOI: 10.1007/s00125-016-3952-1 , and by Hannele Yki-Järvinen, DOI: 10.1007/s00125-016-3944-1 ) and a commentary by the Session Chair, Michael

  13. Continuous Glucose Monitoring Systems: A Review

    PubMed Central

    Vashist, Sandeep Kumar

    2013-01-01

    There have been continuous advances in the field of glucose monitoring during the last four decades, which have led to the development of highly evolved blood glucose meters, non-invasive glucose monitoring (NGM) devices and continuous glucose monitoring systems (CGMS). Glucose monitoring is an integral part of diabetes management, and the maintenance of physiological blood glucose concentration is the only way for a diabetic to avoid life-threatening diabetic complications. CGMS have led to tremendous improvements in diabetic management, as shown by the significant lowering of glycated hemoglobin (HbA1c) in adults with type I diabetes. Most of the CGMS have been minimally-invasive, although the more recent ones are based on NGM techniques. This manuscript reviews the advances in CGMS for diabetes management along with the future prospects and the challenges involved. PMID:26824930

  14. Modeling Glucose Metabolism in the Kidney.

    PubMed

    Chen, Ying; Fry, Brendan C; Layton, Anita T

    2016-06-01

    The mammalian kidney consumes a large amount of energy to support the reabsorptive work it needs to excrete metabolic wastes and to maintain homeostasis. Part of that energy is supplied via the metabolism of glucose. To gain insights into the transport and metabolic processes in the kidney, we have developed a detailed model of the renal medulla of the rat kidney. The model represents water and solute flows, transmural fluxes, and biochemical reactions in the luminal fluid of the nephrons and vessels. In particular, the model simulates the metabolism of oxygen and glucose. Using that model, we have identified parameters concerning glucose transport and basal metabolism that yield predicted blood glucose concentrations that are consistent with experimental measurements. The model predicts substantial axial gradients in blood glucose levels along various medullary structures. Furthermore, the model predicts that in the inner medulla, owing to the relatively limited blood flow and low tissue oxygen tension, anaerobic metabolism of glucose dominates. PMID:27371260

  15. Roles of the Gut in Glucose Homeostasis.

    PubMed

    Holst, Jens Juul; Gribble, Fiona; Horowitz, Michael; Rayner, Chris K

    2016-06-01

    The gastrointestinal tract plays a major role in the regulation of postprandial glucose profiles. Gastric emptying is a highly regulated process, which normally ensures a limited and fairly constant delivery of nutrients and glucose to the proximal gut. The subsequent digestion and absorption of nutrients are associated with the release of a set of hormones that feeds back to regulate subsequent gastric emptying and regulates the release of insulin, resulting in downregulation of hepatic glucose production and deposition of glucose in insulin-sensitive tissues. These remarkable mechanisms normally keep postprandial glucose excursions low, regardless of the load of glucose ingested. When the regulation of emptying is perturbed (e.g., pyloroplasty, gastric sleeve or gastric bypass operation), postprandial glycemia may reach high levels, sometimes followed by profound hypoglycemia. This article discusses the underlying mechanisms. PMID:27222546

  16. Bioluminescence Imaging of Glucose in Tissue Surrounding Polyurethane and Glucose Sensor Implants

    PubMed Central

    Prichard, Heather L; Schroeder, Thies; Reichert, William M; Klitzman, Bruce

    2010-01-01

    Background The bioluminescence technique was used to quantify the local glucose concentration in the tissue surrounding subcutaneously implanted polyurethane material and surrounding glucose sensors. In addition, some implants were coated with a single layer of adipose-derived stromal cells (ASCs) because these cells improve the wound-healing response around biomaterials. Methods Control and ASC-coated implants were implanted subcutaneously in rats for 1 or 8 weeks (polyurethane) or for 1 week only (glucose sensors). Tissue biopsies adjacent to the implant were immediately frozen at the time of explant. Cryosections were assayed for glucose concentration profile using the bioluminescence technique. Results For the polyurethane samples, no significant differences in glucose concentration within 100 μm of the implant surface were found between bare and ASC-coated implants at 1 or 8 weeks. A glucose concentration gradient was demonstrated around the glucose sensors. For all sensors, the minimum glucose concentration of approximately 4 mM was found at the implant surface and increased with distance from the sensor surface until the glucose concentration peaked at approximately 7 mM at 100 μm. Then the glucose concentration decreased to 5.5–6.5 mM more than 100 μmm from the surface. Conclusions The ASC attachment to polyurethane and to glucose sensors did not change the glucose profiles in the tissue surrounding the implants. Although most glucose sensors incorporate a diffusion barrier to reduce the gradient of glucose and oxygen in the tissue, it is typically assumed that there is no steep glucose gradient around the sensors. However, a glucose gradient was observed around the sensors. A more complete understanding of glucose transport and concentration gradients around sensors is critical. PMID:20920425

  17. Measurement of tear glucose levels with amperometric glucose biosensor/capillary tube configuration.

    PubMed

    Yan, Qinyi; Peng, Bo; Su, Gang; Cohan, Bruce E; Major, Terry C; Meyerhoff, Mark E

    2011-11-01

    An amperometric needle-type electrochemical glucose sensor intended for tear glucose measurements is described and employed in conjunction with a 0.84 mm i.d. capillary tube to collect microliter volumes of tear fluid. The sensor is based on immobilizing glucose oxidase on a 0.25 mm o.d. platinum/iridium (Pt/Ir) wire and anodically detecting the liberated hydrogen peroxide from the enzymatic reaction. Inner layers of Nafion and an electropolymerized film of 1,3-diaminobenzene/resorcinol greatly enhance the selectivity for glucose over potential interferences in tear fluid, including ascorbic acid and uric acid. Further, the new sensor is optimized to achieve very low detection limits of 1.5 ± 0.4 μM of glucose (S/N = 3) that is required to monitor glucose levels in tear fluid with a glucose sensitivity of 0.032 ± 0.02 nA/μM (n = 6). Only 4-5 μL of tear fluid in the capillary tube is required when the needle sensor is inserted into the capillary. The glucose sensor was employed to measure tear glucose levels in anesthetized rabbits over an 8 h period while also measuring the blood glucose values. A strong correlation between tear and blood glucose levels was found, suggesting that measurement of tear glucose is a potential noninvasive substitute for blood glucose measurements, and the new sensor configuration could aid in conducting further research in this direction. PMID:21961809

  18. Parsing glucose entry into the brain: novel findings obtained with enzyme-based glucose biosensors.

    PubMed

    Kiyatkin, Eugene A; Wakabayashi, Ken T

    2015-01-21

    Extracellular levels of glucose in brain tissue reflect dynamic balance between its gradient-dependent entry from arterial blood and its use for cellular metabolism. In this work, we present several sets of previously published and unpublished data obtained by using enzyme-based glucose biosensors coupled with constant-potential high-speed amperometry in freely moving rats. First, we consider basic methodological issues related to the reliability of electrochemical measurements of extracellular glucose levels in rats under physiologically relevant conditions. Second, we present data on glucose responses induced in the nucleus accumbens (NAc) by salient environmental stimuli and discuss the relationships between local neuronal activation and rapid glucose entry into brain tissue. Third, by presenting data on changes in NAc glucose induced by intravenous and intragastric glucose delivery, we discuss other mechanisms of glucose entry into the extracellular domain following changes in glucose blood concentrations. Lastly, by showing the pattern of NAc glucose fluctuations during glucose-drinking behavior, we discuss the relationships between "active" and "passive" glucose entry to the brain, its connection to behavior-related metabolic activation, and the possible functional significance of these changes in behavioral regulation. These data provide solid experimental support for the "neuronal" hypothesis of neurovascular coupling, which postulates the critical role of neuronal activity in rapid regulation of vascular tone, local blood flow, and entry of glucose and oxygen to brain tissue to maintain active cellular metabolism. PMID:25490002

  19. A self-powered glucose biosensing system.

    PubMed

    Slaughter, Gymama; Kulkarni, Tanmay

    2016-04-15

    A self-powered glucose biosensor (SPGS) system is fabricated and in vitro characterization of the power generation and charging frequency characteristics in glucose analyte are described. The bioelectrodes consist of compressed network of three-dimensional multi-walled carbon nanotubes with redox enzymes, pyroquinoline quinone glucose dehydrogenase (PQQ-GDH) and laccase functioning as the anodic and cathodic catalyst, respectively. When operated in 45 mM glucose, the biofuel cell exhibited an open circuit voltage and power density of 681.8 mV and 67.86 µW/cm(2) at 335 mV, respectively, with a current density of 202.2 µA/cm(2). Moreover, at physiological glucose concentration (5mM), the biofuel cell exhibits open circuit voltage and power density of 302.1 mV and 15.98 µW/cm(2) at 166.3 mV, respectively, with a current density of 100 µA/cm(2). The biofuel cell assembly produced a linear dynamic range of 0.5-45 mM glucose. These findings show that glucose biofuel cells can be further investigated in the development of a self-powered glucose biosensor by using a capacitor as the transducer element. By monitoring the capacitor charging frequencies, which are influenced by the concentration of the glucose analyte, a linear dynamic range of 0.5-35 mM glucose is observed. The operational stability of SPGS is monitored over a period of 63 days and is found to be stable with 15.38% and 11.76% drop in power density under continuous discharge in 10mM and 20mM glucose, respectively. These results demonstrate that SPGSs can simultaneously generate bioelectricity to power ultra-low powered devices and sense glucose. PMID:26594885

  20. Is fructose sweeter than glucose for rats?

    PubMed

    Ramirez, I

    1996-11-01

    Because it is generally thought that the intensity of the taste of fructose is greater than that of glucose for rats, it seemed surprising when sham-fed rats drank substantially less of a mixture of 6% fructose plus saccharin than of a mixture of 6% glucose plus saccharin. At least 3 different factors contribute to this effect. First, the taste of fructose is less attractive to rats than is the taste of glucose; sham-fed rats strongly preferred glucose over fructose (no saccharin was used in this experiment). The second factor is experience. Rats having substantial previous experience with glucose, but not with fructose, consistently preferred glucose over fructose. Conversely, rats having substantial previous experience with fructose, but not with glucose, initially showed no consistent preference but subsequently tended to prefer glucose. The third factor is an interaction between saccharin and the type of sugar. Rats given only one solution at a time drink approximately as much fructose as glucose when the solutions contain no saccharin. The addition of 0.25% saccharin to 6% glucose stimulated intake, whereas the addition of the same amount of saccharin to 6% fructose did not stimulate intake. As a result, rats ingested substantially more of a mixture of 0.25% saccharin plus 6% glucose than they did of a comparable mixture of saccharin and fructose, even though rats ingest similar amounts of fructose and glucose without saccharin in single-bottle tests. Because the differential effect of saccharin on intake appeared within 2 h in naive rats, and did not greatly change over a 3-day period, it is probably not attributable to conditioning. These results suggest that these sugars have qualitatively different tastes. PMID:8916185

  1. Pancreatic regulation of glucose homeostasis.

    PubMed

    Röder, Pia V; Wu, Bingbing; Liu, Yixian; Han, Weiping

    2016-01-01

    In order to ensure normal body function, the human body is dependent on a tight control of its blood glucose levels. This is accomplished by a highly sophisticated network of various hormones and neuropeptides released mainly from the brain, pancreas, liver, intestine as well as adipose and muscle tissue. Within this network, the pancreas represents a key player by secreting the blood sugar-lowering hormone insulin and its opponent glucagon. However, disturbances in the interplay of the hormones and peptides involved may lead to metabolic disorders such as type 2 diabetes mellitus (T2DM) whose prevalence, comorbidities and medical costs take on a dramatic scale. Therefore, it is of utmost importance to uncover and understand the mechanisms underlying the various interactions to improve existing anti-diabetic therapies and drugs on the one hand and to develop new therapeutic approaches on the other. This review summarizes the interplay of the pancreas with various other organs and tissues that maintain glucose homeostasis. Furthermore, anti-diabetic drugs and their impact on signaling pathways underlying the network will be discussed. PMID:26964835

  2. Pancreatic regulation of glucose homeostasis

    PubMed Central

    Röder, Pia V; Wu, Bingbing; Liu, Yixian; Han, Weiping

    2016-01-01

    In order to ensure normal body function, the human body is dependent on a tight control of its blood glucose levels. This is accomplished by a highly sophisticated network of various hormones and neuropeptides released mainly from the brain, pancreas, liver, intestine as well as adipose and muscle tissue. Within this network, the pancreas represents a key player by secreting the blood sugar-lowering hormone insulin and its opponent glucagon. However, disturbances in the interplay of the hormones and peptides involved may lead to metabolic disorders such as type 2 diabetes mellitus (T2DM) whose prevalence, comorbidities and medical costs take on a dramatic scale. Therefore, it is of utmost importance to uncover and understand the mechanisms underlying the various interactions to improve existing anti-diabetic therapies and drugs on the one hand and to develop new therapeutic approaches on the other. This review summarizes the interplay of the pancreas with various other organs and tissues that maintain glucose homeostasis. Furthermore, anti-diabetic drugs and their impact on signaling pathways underlying the network will be discussed. PMID:26964835

  3. Sex steroids and glucose metabolism.

    PubMed

    Allan, Carolyn A

    2014-01-01

    Testosterone levels are lower in men with metabolic syndrome and type 2 diabetes mellitus (T2DM) and also predict the onset of these adverse metabolic states. Body composition (body mass index, waist circumference) is an important mediator of this relationship. Sex hormone binding globulin is also inversely associated with insulin resistance and T2DM but the data regarding estrogen are inconsistent. Clinical models of androgen deficiency including Klinefelter's syndrome and androgen deprivation therapy in the treatment of advanced prostate cancer confirm the association between androgens and glucose status. Experimental manipulation of the insulin/glucose milieu and suppression of endogenous testicular function suggests the relationship between androgens and insulin sensitivity is bidirectional. Androgen therapy in men without diabetes is not able to differentiate the effect on insulin resistance from that on fat mass, in particular visceral adiposity. Similarly, several small clinical studies have examined the efficacy of exogenous testosterone in men with T2DM, however, the role of androgens, independent of body composition, in modifying insulin resistance is uncertain. PMID:24457840

  4. Circadian control of glucose metabolism

    PubMed Central

    Kalsbeek, Andries; la Fleur, Susanne; Fliers, Eric

    2014-01-01

    The incidence of obesity and type 2 diabetes mellitus (T2DM) has risen to epidemic proportions. The pathophysiology of T2DM is complex and involves insulin resistance, pancreatic β-cell dysfunction and visceral adiposity. It has been known for decades that a disruption of biological rhythms (which happens the most profoundly with shift work) increases the risk of developing obesity and T2DM. Recent evidence from basal studies has further sparked interest in the involvement of daily rhythms (and their disruption) in the development of obesity and T2DM. Most living organisms have molecular clocks in almost every tissue, which govern rhythmicity in many domains of physiology, such as rest/activity rhythms, feeding/fasting rhythms, and hormonal secretion. Here we present the latest research describing the specific role played by the molecular clock mechanism in the control of glucose metabolism and speculate on how disruption of these tissue clocks may lead to the disturbances in glucose homeostasis. PMID:24944897

  5. Enzyme Analysis to Determine Glucose Content

    NASA Astrophysics Data System (ADS)

    Carpenter, Charles; Ward, Robert E.

    Enzyme analysis is used for many purposes in food science and technology. Enzyme activity is used to indicate adequate processing, to assess enzyme preparations, and to measure constituents of foods that are enzyme substrates. In this experiment, the glucose content of corn syrup solids is determined using the enzymes, glucose oxidase and peroxidase. Glucose oxidase catalyzes the oxidation of glucose to form hydrogen peroxide (H2O2), which then reacts with a dye in the presence of peroxidase to give a stable colored product.

  6. Glucose metabolism in rat retinal pigment epithelium.

    PubMed

    Coffe, Víctor; Carbajal, Raymundo C; Salceda, Rocío

    2006-01-01

    The retinal pigment epithelium (RPE) is the major transport pathway for exchange of metabolites and ions between choroidal blood supply and the neural retina. To gain insight into the mechanisms controlling glucose metabolism in RPE and its possible relationship to retinopathy, we studied the influence of different glucose concentrations on glycogen and lactate levels and CO(2) production in RPE from normal and streptozotocin-treated diabetic rats. Incubation of normal RPE in the absence of glucose caused a decrease in lactate production and glycogen content. In normal RPE, increasing glucose concentrations from 5.6 mM to 30 mM caused a four-fold increase in glucose accumulation and CO(2) yield, as well as reduction in lactate and glycogen production. In RPE from diabetic rats glucose accumulation did not increase in the presence of high glucose substrate, but it showed a four- and a seven-fold increase in CO(2) production through the mitochondrial and pentose phosphate pathways, respectively. We found high glycogen levels in RPE which can be used as an energy reserve for RPE itself and/or neural retina. Findings further show that the RPE possesses a high oxidative capacity. The large increase in glucose shunting to the pentose phosphate pathway in diabetic retina exposed to high glucose suggests a need for reducing capacity, consistent with increased oxidative stress. PMID:16475003

  7. Fabrication of Nanoindented Electrodes for Glucose Detection

    PubMed Central

    Slaughter, Gymama

    2010-01-01

    Background The objective of this article was to design, fabricate, and evaluate a novel type of glucose biosensors based on the use of atomic force microscopy to create nanoindented electrodes (NIDEs) for the selective detection of glucose. Methods Atomic force microscopy nanoindentation techniques were extended to covalently immobilized glucose oxidase on NIDEs via composite hydrogel membranes composed of interpenetrating networks of inherently conductive poly(3,4-ethylenedioxythiophene) tetramethacrylate grown within ultraviolet cross-linked hydroxyethylmethacrylate-based hydrogels to produce an in vitro amperometric NIDE biosensor for the long-term monitoring of glucose. Results The calibration curve for glucose was linear from 0.25 to 20 mM. Results showed that the NIDE glucose biosensor has a much higher detection sensitivity of 0.32 μA/mM and rapid response times (<5 seconds). There was no interference from the competing interferent (fructose) present; the only interference was from species that react with H2O2 (ascorbic acid). The linear equation was Bresponse (μA) = 0.323 [glucose] (mM) + 0.634 (μA); n = 24, r2 = 0.994. Conclusion Results showed that the resultant NIDE glucose biosensor increases the dynamic range, device sensitivity, and response time and has excellent detecting performance for glucose. PMID:20307392

  8. Glucose Transporters in Cardiac Metabolism and Hypertrophy

    PubMed Central

    Shao, Dan; Tian, Rong

    2016-01-01

    The heart is adapted to utilize all classes of substrates to meet the high-energy demand, and it tightly regulates its substrate utilization in response to environmental changes. Although fatty acids are known as the predominant fuel for the adult heart at resting stage, the heart switches its substrate preference toward glucose during stress conditions such as ischemia and pathological hypertrophy. Notably, increasing evidence suggests that the loss of metabolic flexibility associated with increased reliance on glucose utilization contribute to the development of cardiac dysfunction. The changes in glucose metabolism in hypertrophied hearts include altered glucose transport and increased glycolysis. Despite the role of glucose as an energy source, changes in other nonenergy producing pathways related to glucose metabolism, such as hexosamine biosynthetic pathway and pentose phosphate pathway, are also observed in the diseased hearts. This article summarizes the current knowledge regarding the regulation of glucose transporter expression and translocation in the heart during physiological and pathological conditions. It also discusses the signaling mechanisms governing glucose uptake in cardiomyocytes, as well as the changes of cardiac glucose metabolism under disease conditions. PMID:26756635

  9. TLR2 expression doesn’t change in ox-LDL mediated inflammation in Human umbilical vein endothelial cells under high glucose culture

    PubMed Central

    Li, Jilin; Chen, Shuying; Cai, Xiangna; Wang, Huaiwen; Wang, Xin; Wang, Wei

    2015-01-01

    Background: Inflammatory responses induced by ox-LDL play important roles in atherogenesis, and could be promoted in diabetic patients. Toll-like receptor (TLR)2 is an innate inflammatory receptor, and is enhanced in human umbilical vein endothelial cells (HUVECs) under high glucose conditions. Ox-LDL-TLR2 pathway activation and further inflammation in monocytes are involved in the atherosclerosis formation. Objective: What role of TLR2 plays on ox-LDL-induced inflammation in HUVECs remains unclear, especially in high glucose conditions. The purpose of this study is to explore the effect and role of ox-LDL-TLR2 pathway on the inflammatory responses in HUVECs. Methods: 1 hour prior to the treatment, HUVECs were treated with or without neutralizing anti-TLR2 antibody. After that, HUVECs were treated with ox-LDL (20, or 40 μg/ml) or LPS (200 ng/ml) under normal and high glucose conditions. The expressions of ICAM-1 and TLR2 protein were analyzed by immunoblotting, and IL-6 and IL-8 were measured by ELISA. Results: Compared with those in normal glucose condition, IL-6 and IL-8 expression were increased in high glucose condition. The stimulation of ox-LDL and LPS both increased the expression of ICAM-1, IL-6 and IL-8, but did not change TLR2 protein expression in both normal and high glucose conditions. Additionally, the expression of ICAM-1, IL-6 and IL-8 was not changed when TLR2 was knocked out under these two conditions. Conclusion: The inflammatory responses induced by Ox-LDL were not changed with or without TLR2 under both normal and high glucose conditions in HUVECs. Our study indicates TLR2 is not involved in the ox-LDL mediated endothelial injury under high glucose conditions, which is an important step of atherosclerosis formation in diabetes. PMID:26885173

  10. Naked eye detection of glucose in urine using glucose oxidase immobilized gold nanoparticles.

    PubMed

    Radhakumary, Changerath; Sreenivasan, Kunnatheeri

    2011-04-01

    Colloidal gold is extensively used for molecular sensing because of the flexibilities it offers in terms of modification of the gold nanoparticle surface with a variety of functional groups using thiol chemistry. We describe a simple assay that allows the visual detection of glucose in aqueous samples and demonstrates its applicability by estimating glucose in urine. To enable the glucose detection, we functionalized the thiol capped gold nanoparticles with glucose oxidase, the enzyme specific to β-D glucose, using carbodiimide chemistry. The visible color change of the GOD-functionalized gold nanoparticles from red to blue on interaction with glucose is the principle applied here for the sensing of urine glucose level. The solution turns blue when the glucose concentration exceeds 100 μg/mL. The approach depicted here seems to be important, particularly in third world countries where high tech diagnostics aids are inaccessible to the bulk of the population. PMID:21391552

  11. Type 2 Diabetes Risk Allele UBE2E2 Is Associated With Decreased Glucose-Stimulated Insulin Release in Elderly Chinese Han Individuals.

    PubMed

    Xu, Kuanfeng; Jiang, Lin; Zhang, Mei; Zheng, Xuqin; Gu, Yong; Wang, Zhixiao; Cai, Yun; Dai, Hao; Shi, Yun; Zheng, Shuai; Chen, Yang; Ji, Li; Xu, Xinyu; Chen, Heng; Sun, Min; Yang, Tao

    2016-05-01

    Recently, rs163182 in KCNQ1, rs7612463 in UBE2E2, rs7119 in HMG20A, and rs6815464 in MAEA were discovered as type 2 diabetes (T2D) loci unique to Asians, and rs13342692 in SLC16A11 were newly reported as T2D loci in multiethnicities by genome-wide association (GWA) studies. The aim of the present study is to ascertain the potential associations between these variants and T2D risk in the Chinese population, and characterize diabetic-related quantitative traits underlying these variants.A total of 4268 Chinese Han individuals (1754 patients with T2D and 2514 glucose-tolerant health subjects, age ≥40 years) were genotyped for these 5 variants. All the health individuals underwent an oral glucose tolerance test (OGTT), and measures of insulin release and sensitivity were estimated from insulinogenic, BIGTT, Matsuda, and disposition indices. The associations were determined by using logistic regression analysis.After adjustment for age, sex, and BMI, rs163182 in KCNQ1 (P = 0.002) and rs7612463 in UBE2E2 (P = 0.024) were found to be associated with T2D risk in Chinese Han population. The risk C allele of rs7612463 in UBE2E2 is associated with decreased IGI (P = 0.001), BIGTT-AIR (P = 0.002), CIR (P = 0.002), and DI (P = 0.006). The other 4 variants did not associate with insulin release or sensitivity.UBE2E2 rs7612463 may mediate its diabetogenic impact on insulin response, which highly depends on the impairment of β-cell function. PMID:27175665

  12. Interference by acetaminophen in the glucose oxidase-peroxidase method for blood glucose determination.

    PubMed

    Kaufmann-Raab, I; Jonen, H G; Jähnchen, E; Kahl, G F; Groth, U

    1976-10-01

    Acetaminophen, p-aminophenol, and oxyphenbutazone interfere with the glucose oxidase/peroxidase method for glucose. Structurally related compounds that lack a free phenolic hydroxyl group (acetanilide, aniline, and phenylbutazone) do not interfere. During the analytical procedure acetaminophen is consumed. One mole of acetaminophen leads to an apparent loss of four moles of glucose. The hexokinase/glucose-6-phosphate dehydrogenase method (Boehringer Hexokinase method) is not affected by these substances. PMID:975521

  13. Development of a Robust Optical Glucose Sensor

    NASA Astrophysics Data System (ADS)

    Cote, Gerard Laurence

    1990-01-01

    The long term objective of this research was the development of a noninvasive, optically-based, polarimetric sensor to monitor in vivo glucose concentrations. The goal of diabetes therapy is to approximate the 24-hour blood glucose profile of a normal individual. There have been major advances in the development of reliable, versatile, and accurate pumps for the delivery of insulin to diabetic patients and in the development of control algorithms for closed-loop insulin delivery, however, there remain major obstacles to the development of clinically useful, continuous glucose sensors. The development of an accurate noninvasive glucose sensor would have significant application in the diagnosis and management of diabetes mellitis both in conjunction with, and independent of, the glucose pump controller applications. The linear polarization vector of light routes when it interacts with an optically active material such as glucose. The amount of rotation of polarization is directly proportional to the glucose concentration and to the path length. The ability to quantitate blood glucose levels for the limited available path length in our primary sensing site, namely, the anterior chamber of the eye, therefore depends on the signal-to-noise ratio of the polarization detector. Our primary research focused on the development and testing of a prototype optical polarimetry system using D + glucose solution in a test cell, as well as using an enucleated human eye to assess the sensitivity of the system to measure physiologic glucose levels for the approximate one centimeter path length present in the anterior chamber of the eye. Our research has led to the development of a true phase technique in which helium neon laser light was coupled through a rotating linear polarizer along with two stationary linear polarizers and two detectors to produce reference and signal outputs whose amplitudes varied sinusoidally and whose phase was proportional to the rotation of light caused by

  14. Hypothalamic glucose sensing: making ends meet

    PubMed Central

    Routh, Vanessa H.; Hao, Lihong; Santiago, Ammy M.; Sheng, Zhenyu; Zhou, Chunxue

    2014-01-01

    The neuroendocrine system governs essential survival and homeostatic functions. For example, growth is needed for development, thermoregulation maintains optimal core temperature in a changing environment, and reproduction ensures species survival. Stress and immune responses enable an organism to overcome external and internal threats while the circadian system regulates arousal and sleep such that vegetative and active functions do not overlap. All of these functions require a significant portion of the body's energy. As the integrator of the neuroendocrine system, the hypothalamus carefully assesses the energy status of the body in order to appropriately partition resources to provide for each system without compromising the others. While doing so the hypothalamus must ensure that adequate glucose levels are preserved for brain function since glucose is the primary fuel of the brain. To this end, the hypothalamus contains specialized glucose sensing neurons which are scattered throughout the nuclei controlling distinct neuroendocrine functions. We hypothesize that these neurons play a key role in enabling the hypothalamus to partition energy to meet these peripheral survival needs without endangering the brain's glucose supply. This review will first describe the varied mechanisms underlying glucose sensing in neurons within discrete hypothalamic nuclei. We will then evaluate the way in which peripheral energy status regulates glucose sensitivity. For example, during energy deficit such as fasting specific hypothalamic glucose sensing neurons become sensitized to decreased glucose. This increases the gain of the information relay when glucose availability is a greater concern for the brain. Finally, changes in glucose sensitivity under pathological conditions (e.g., recurrent insulin-hypoglycemia, diabetes) will be addressed. The overall goal of this review is to place glucose sensing neurons within the context of hypothalamic control of neuroendocrine function

  15. Responses of Blood Glucose, Insulin, Glucagon, and Fatty Acids to Intraruminal Infusion of Propionate in Hanwoo

    PubMed Central

    Oh, Y. K.; Eun, J. S.; Lee, S. C.; Chu, G. M.; Lee, Sung S.; Moon, Y. H.

    2015-01-01

    This study was carried out to investigate the effects of intraruminal infusion of propionate on ruminal fermentation characteristics and blood hormones and metabolites in Hanwoo (Korean cattle) steers. Four Hanwoo steers (average body wt. 270 kg, 13 month of age) equipped with rumen cannula were infused into rumens with 0.0 M (Water, C), 0.5 M (37 g/L, T1), 1.0 M (74 g/L, T2) and 1.5 M (111 g/L, T3) of propionate for 1 hour per day and allotted by 4×4 Latin square design. On the 5th day of infusion, samples of rumen and blood were collected at 0, 60, 120, 180, and 300 min after intraruminal infusion of propionate. The concentrations of serum glucose and plasma glucagon were not affected (p>0.05) by intraruminal infusion of propionate. The serum insulin concentration at 60 min after infusion was significantly (p<0.05) higher in T3 than in C, while the concentration of non-esterified fatty acid (NEFA) at 60 and 180 min after infusion was significantly (p<0.05) lower in the propionate treatments than in C. Hence, intraruminal infusion of propionate stimulates the secretion of insulin, and decreases serum NEFA concentration rather than the change of serum glucose concentration. PMID:25557815

  16. 21 CFR 862.1345 - Glucose test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Glucose test system. 862.1345 Section 862.1345....1345 Glucose test system. (a) Identification. A glucose test system is a device intended to measure glucose quantitatively in blood and other body fluids. Glucose measurements are used in the diagnosis...

  17. 21 CFR 862.1345 - Glucose test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Glucose test system. 862.1345 Section 862.1345....1345 Glucose test system. (a) Identification. A glucose test system is a device intended to measure glucose quantitatively in blood and other body fluids. Glucose measurements are used in the diagnosis...

  18. Glucose concentration in parotid saliva after glucose/food intake in individuals with glucose intolerance and diabetes mellitus.

    PubMed

    Borg Andersson, A; Birkhed, D; Berntorp, K; Lindgärde, F; Matsson, L

    1998-10-01

    The concentration of glucose in parotid saliva was measured after glucose/food intake in two separate studies (A and B). In Study A, 10 subjects with impaired glucose tolerance (IGT), 10 subjects with newly diagnosed Type 2 diabetes and 12 healthy controls were included. Study B comprised 15 subjects with Type 1 or Type 2 diabetes on insulin treatment, nine subjects with Type 2 diabetes on treatment with oral antidiabetic drugs and 12 healthy controls. After a 10-h overnight fast, the participants in Study A were given a 75 g oral glucose load, while those in Study B received a standardized breakfast. Citric acid-stimulated parotid saliva was collected up to two hours after the intake. Capillary blood and gingival exudate samples were also taken. On the basis of AUC values (area under the curve over baseline), the glucose concentration in parotid saliva increased significantly in individuals with IGT and Type 2 diabetes compared with controls in Study A and in diabetic patients on treatment with insulin and oral antidiabetic drugs compared with controls in Study B. No effect by the glucose/food intake on the glucose concentration in gingival exudate could be demonstrated in any of the studies. The correlation coefficient between the AUC values of glucose in saliva and blood, when all three groups were combined, was 0.38 in Study A and 0.52 in Study B. It is concluded that the concentration of glucose in parotid saliva is elevated at least 2 h after glucose/food intake in individuals with both IGT and manifest diabetes mellitus. PMID:9786322

  19. Glucose-6-Phosphate Dehydrogenase Deficiency.

    PubMed

    Luzzatto, Lucio; Nannelli, Caterina; Notaro, Rosario

    2016-04-01

    G6PD is a housekeeping gene expressed in all cells. Glucose-6-phosphate dehydrogenase (G6PD) is part of the pentose phosphate pathway, and its main physiologic role is to provide NADPH. G6PD deficiency, one of the commonest inherited enzyme abnormalities in humans, arises through one of many possible mutations, most of which reduce the stability of the enzyme and its level as red cells age. G6PD-deficient persons are mostly asymptomatic, but they can develop severe jaundice during the neonatal period and acute hemolytic anemia when they ingest fava beans or when they are exposed to certain infections or drugs. G6PD deficiency is a global health issue. PMID:27040960

  20. Glucose kinetics during prolonged exercise in highly trained human subjects: effect of glucose ingestion

    PubMed Central

    Jeukendrup, Asker E; Raben, Anne; Gijsen, Annemie; Stegen, Jos H C H; Brouns, Fred; Saris, Wim H M; Wagenmakers, Anton J M

    1999-01-01

    The objectives of this study were (1) to investigate whether glucose ingestion during prolonged exercise reduces whole body muscle glycogen oxidation, (2) to determine the extent to which glucose disappearing from the plasma is oxidized during exercise with and without carbohydrate ingestion and (3) to obtain an estimate of gluconeogenesis. After an overnight fast, six well-trained cyclists exercised on three occasions for 120 min on a bicycle ergometer at 50% maximum velocity of O2 uptake and ingested either water (Fast), or a 4% glucose solution (Lo-Glu) or a 22% glucose solution (Hi-Glu) during exercise. Dual tracer infusion of [U-13C]-glucose and [6,6-2H2]-glucose was given to measure the rate of appearance (Ra) of glucose, muscle glycogen oxidation, glucose carbon recycling, metabolic clearance rate (MCR) and non-oxidative disposal of glucose. Glucose ingestion markedly increased total Ra especially with Hi-Glu. After 120 min Ra and rate of disappearance (Rd) of glucose were 51-52 μmol kg−1 min−1 during Fast, 73-74 μmol kg−1 min−1 during Lo-Glu and 117–119 μmol kg−1 min−1 during Hi-Glu. The percentage of Rd oxidized was between 96 and 100% in all trials. Glycogen oxidation during exercise was not reduced by glucose ingestion. The vast majority of glucose disappearing from the plasma is oxidized and MCR increased markedly with glucose ingestion. Glucose carbon recycling was minimal suggesting that gluconeogenesis in these conditions is negligible. PMID:10050023

  1. Thermoinactivation Mechanism of Glucose Isomerase

    NASA Astrophysics Data System (ADS)

    Lim, Leng Hong; Saville, Bradley A.

    In this article, the mechanisms of thermoinactivation of glucose isomerase (GI) from Streptomyces rubiginosus (in soluble and immobilized forms) were investigated, particularly the contributions of thiol oxidation of the enzyme's cysteine residue and a "Maillard-like" reaction between the enzyme and sugars in high fructose corn syrup (HFCS). Soluble GI (SGI) was successfully immobilized on silica gel (13.5 μm particle size), with an activity yield between 20 and 40%. The immobilized GI (IGI) has high enzyme retention on the support during the glucose isomerization process. In batch reactors, SGI (half-life =145 h) was more stable than IGI (half-life=27 h) at 60°C in HFCS, whereas at 80°C, IGI (half-life=12 h) was more stable than SGI (half-life=5.2 h). IGI was subject to thiol oxidation at 60°C, which contributed to the enzyme's deactivation. IGI was subject to thiol oxidation at 80°C, but this did not contribute to the deactivation of the enzyme. SGI did not undergo thiol oxidation at 60°C, but at 80°C SGI underwent severe precipitation and thiol oxidation, which caused the enzyme to deactivate. Experimental results show that immobilization suppresses the destablizing effect of thiol oxidation on GI. A "Maillard-like" reaction between SGI and the sugars also caused SGI thermoinactivation at 60, 70, and 80°C, but had minimal effect on IGI. At 60 and 80°C, IGI had higher thermostability in continuous reactors than in batch reactors, possibily because of reduced contact with deleterious compounds in HFCS.

  2. Master Regulators in Plant Glucose Signaling Networks

    PubMed Central

    Sheen, Jen

    2014-01-01

    The daily life of photosynthetic plants revolves around sugar production, transport, storage and utilization, and the complex sugar metabolic and signaling networks integrate internal regulators and environmental cues to govern and sustain plant growth and survival. Although diverse sugar signals have emerged as pivotal regulators from embryogenesis to senescence, glucose is the most ancient and conserved regulatory signal that controls gene and protein expression, cell-cycle progression, central and secondary metabolism, as well as growth and developmental programs. Glucose signals are perceived and transduced by two principal mechanisms: direct sensing through glucose sensors and indirect sensing via a variety of energy and metabolite sensors. This review focuses on the comparative and functional analyses of three glucose-modulated master regulators in Arabidopsis thaliana, the hexokinase1 (HXK1) glucose sensor, the energy sensor kinases KIN10/KIN11 inactivated by glucose, and the glucose-activated target of rapamycin (TOR) kinase. These regulators are evolutionarily conserved, but have evolved universal and unique regulatory wiring and functions in plants and animals. They form protein complexes with multiple partners as regulators or effectors to serve distinct functions in different subcellular locales and organs, and play integrative and complementary roles from cellular signaling and metabolism to development in the plant glucose signaling networks. PMID:25530701

  3. Fundamental sensing limit of electrochemical glucose sensors.

    PubMed

    Louchis, Kevin; O'Driscoll, Stephen

    2011-01-01

    This paper investigates the inherent sensitivity limit, deactivation of glucose oxidase, of a glucose oxidase based electrochemical glucose sensor for in vivo monitoring of blood glucose concentration. Results in this paper show that the current density sensitivity to glucose decreases from 1200 nA/mm(2)/mM at initial implantation to 100 nA/mm(2)/mM after an implantation time of 2 years, when degradation due to glucose oxidase deactivation only is considered. Even as the sensor signal strength decreases, if the sensing electronics are sufficiently discriminating then a useful measure of blood glucose concentration can be extracted. This work aims to determine both how the glucose oxidase based sensor's signal-to-noise ratio degrades over long time scales and the electronic circuit requirements to achieve multi-year device lifetimes. Two sensing amplifier techniques are presented which can be used to detect the signal generated by the sensor. The noise performance of each technique is compared with the noise performance of the sensor and mutli-year lifetimes are shown to be feasible. PMID:22256115

  4. A Differential Dielectric Affinity Glucose Sensor

    PubMed Central

    Huang, Xian; Leduc, Charles; Ravussin, Yann; Li, Siqi; Davis, Erin; Song, Bing; Li, Dachao; Xu, Kexin; Accili, Domenico; Wang, Qian; Leibel, Rudolph; Lin, Qiao

    2013-01-01

    A continuous glucose monitor with a differential dielectric sensor implanted within the subcutaneous tissue that determines the glucose in the interstitial fluid is presented. The device, created using microelectromechanical systems (MEMS) technology, consists of sensing and reference modules that are identical in design and placed in close proximity. Each module contains a microchamber housing a pair of capacitive electrodes residing on the device substrate and embedded in a suspended, perforated polymer diaphragm. The microchambers, enclosed in semi-permeable membranes, are filled with either a polymer solution that has specific affinity to glucose or a glucose-insensitive reference solution. To accurately determine the glucose concentration, changes in the permittivity of the sensing and the reference solutions induced by changes in glucose concentration are measured differentially. In vitro characterization demonstrated the sensor capable of measuring glucose concentrations from 0 to 500 mg/dL with resolution and accuracy of ∼1.7 μg/dL and ∼1.74 mg/dL, respectively. In addition, device drift was reduced to 1.4% (uncontrolled environment) and 11% (5 °C of temperature variation) of that from non-differential measurements, indicating significant stability improvements. Preliminary animal testing demonstrated that the differential sensor accurately tracks glucose concentration in blood. This sensor can potentially be used clinically as a subcutaneously implanted continuous monitoring device in diabetic patients. PMID:24220675

  5. Ophthalmic glucose monitoring using disposable contact lenses.

    PubMed

    Geddes, Chris

    2004-01-01

    We have developed a range of disposable and colorless tear glucose sensing contact lenses, using off-the-shelf lenses embedded with new water soluble, highly fluorescent and glucose sensitive boronic acid containing fluorophores. The new lenses are readily able to track tear glucose levels and therefore blood glucose levels, which are ideally suited for potential use by diabetics. The fluorescence responses from the lenses can be monitored using simple excitation and emission detection devices. The novelty of our approach is two fold. Firstly, the notion of sensing extremely low glucose concentrations in tears, which track blood levels, by our contact lens approach, and secondly, the unique compatibility of our new glucose signaling probes with the internal mildly acidic contact lens environment. The new lenses are therefore ideal for the noninvasive and continuous monitoring of tear glucose, with a 15 minute response time, and a measured shelf life in excess of 3 months. In this invited article, we show that fluorescence based signaling using plastic disposable lenses, which have already been industrially optimized with regard to vision correction and oxygen / analyte permeability etc, may a notable alternative to invasive and random finger pricking, the most widely used glucose monitoring technology by diabetics. PMID:17271473

  6. A bioluminescent assay for measuring glucose uptake.

    PubMed

    Valley, Michael P; Karassina, Natasha; Aoyama, Natsuyo; Carlson, Coby; Cali, James J; Vidugiriene, Jolanta

    2016-07-15

    Identifying activators and inhibitors of glucose uptake is critical for both diabetes management and anticancer therapy. To facilitate such studies, easy-to-use nonradioactive assays are desired. Here we describe a bioluminescent glucose uptake assay for measuring glucose transport in cells. The assay is based on the uptake of 2-deoxyglucose and the enzymatic detection of the 2-deoxyglucose-6-phosphate that accumulates. Uptake can be measured from a variety of cell types, it can be inhibited by known glucose transporter inhibitors, and the bioluminescent assay yields similar results when compared with the radioactive method. With HCT 116 cells, glucose uptake can be detected in as little as 5000 cells and remains linear up to 50,000 cells with signal-to-background values ranging from 5 to 45. The assay can be used to screen for glucose transporter inhibitors, or by multiplexing with viability readouts, changes in glucose uptake can be differentiated from overall effects on cell health. The assay also can provide a relevant end point for measuring insulin sensitivity. With adipocytes and myotubes, insulin-dependent increases in glucose uptake have been measured with 10- and 2-fold assay windows, respectively. Significant assay signals of 2-fold or more have also been measured with human induced pluripotent stem cell (iPSC)-derived cardiomyocytes and skeletal myoblasts. PMID:27130501

  7. Glucose-Induced Acidification in Yeast Cultures

    ERIC Educational Resources Information Center

    Myers, Alan; Bourn, Julia; Pool, Brynne

    2005-01-01

    We present an investigation (for A-level biology students and equivalent) into the mechanism of glucose-induced extracellular acidification in unbuffered yeast suspensions. The investigation is designed to enhance understanding of aspects of the A-level curriculum that relate to the phenomenon (notably glucose catabolism) and to develop key skills…

  8. Acute Glucose Response Properties Beyond Feeding.

    PubMed

    Burnett, C Joseph; Krashes, Michael J

    2016-05-01

    Hypothalamic AgRP neurons potently coordinate feeding behavior to ensure an organism's viability. However, their acute role in glucose-regulatory function remains to be addressed. Steculorum et al. now report that activation of a specific set of AgRP neurons results in an impairment of insulin-stimulated glucose uptake in brown fat through a myogenic signature program. PMID:27052261

  9. Glucose tolerance test - non-pregnant

    MedlinePlus

    ... have pre-diabetes or diabetes: A 2 hour value between 140 and 200 mg/dL is called impaired glucose tolerance. Your doctor may call this "pre-diabetes." It means you are at increased risk of developing diabetes over time. A glucose level ...

  10. Glucose Disappearance in Biological Treatment Systems

    PubMed Central

    Jeris, John S.; Cardenas, Raul R.

    1966-01-01

    Laboratory scale anaerobic and aerobic treatment units were conditioned with a daily slug-feed of glucose. After a period of acclimation and stabilization, glucose disappearance was monitored continuously after the slug feed. A continuous sampling apparatus is described. Mathematical analysis of the data indicate zero-order reactions for both biological treatment systems. PMID:16349685

  11. Glucose metabolism in patients with Cushing's syndrome.

    PubMed

    Bowes, S B; Benn, J J; Scobie, I N; Umpleby, A M; Lowy, C; Sönksen, P H

    1991-04-01

    Glucose intolerance, sometimes severe enough to cause frank diabetes mellitus, is a frequent feature of Cushing's syndrome. The primary cause of the hyperglycaemia, whether due to glucose over-production or under-utilization, remains unresolved. We therefore measured glucose turnover using an intravenous bolus of 3-3H glucose in 14 normoglycaemic patients with Cushing's syndrome and 14 control subjects. Seven of the patients with Cushing's syndrome were also restudied post-operatively. Plasma glucose concentrations were similar in all three groups whereas glucose metabolic clearance rate (MCR) (1.80 +/- 0.06 ml/min/kg) and glucose turnover rate (9.09 +/- 0.36 mumol/min/kg) were significantly reduced in patients with Cushing's syndrome compared to normal subjects (2.21 +/- 0.1; P less than 0.001; 10.90 +/- 0.50; P less than 0.01) and rose post-operatively to normal values (2.35 +/- 0.14 ml/min/kg; 11.07 +/- 0.48 mumol/min/kg). We conclude from these results that the hyperglycaemia sometimes found in Cushing's syndrome may be primarily due to decreased utilization rather than increased glucose production. PMID:1879061

  12. Glucose Biosensor Based on Immobilization of Glucose Oxidase in Platinum Nanoparticles/Graphene/Chitosan Nanocomposite Film

    SciTech Connect

    Wu, Hong; Wang, Jun; Kang, Xinhuang; Wang, Chong M.; Wang, Donghai; Liu, Jun; Aksay, Ilhan A.; Lin, Yuehe

    2009-09-01

    The bionanocomposite film consisting of glucose oxidase/Pt/functional graphene sheets/chitosan (GOD/Pt/FGS/chitosan) for glucose sensing was described. With the electrocatalytic synergy of FGS and Pt nanoparticles to hydrogen peroxide, a sensitive biosensor with detection limit of 0.6 µM glucose was achieved. The biosensor also had good reproducibility, long term stability and negligible interfering signals from ascorbic acid and uric acid comparing to the response to glucose. The large surface area and good conductivity of graphene suggests that graphene is a potential candidate for sensor material. The hybrid nanocomposite glucose sensor provides new opportunity for clinical diagnosis and point-of-care applications.

  13. Glucose Recognition in Vitro Using Fluorescent Spectroscopy

    SciTech Connect

    Noronha, G; Heiss, A M; Reilly, J R; Vachon, Jr, D J; Cary, D R; Zaitseva, N P; Reibold, R A; Lane, S M; Peyser, T A; Satcher, J H

    2001-04-25

    Diabetes is a disease that affects over 16 million people in the USA at a cost of 100 billion dollars annually. The ability to regulate insulin delivery in people with Type 1 diabetes is imperative as is the need to manage glucose levels in all people with this disease. Our current method for monitoring glucose is a (FDA approved) minimally invasive enzymatic sensor that can measure glucose levels in vivo for three days. We are focused on developing a noninvasive implantable glucose sensor that will be interrogated by an external device. The material must be robust, easy to process, biocompatible and resistant to biofouling. In this Presentation we will discuss the development of a new polymeric matrix that can recognize physiological levels of glucose in vitro using fluorescent spectroscopy.

  14. Glucose-lactose diauxie in Escherichia coli.

    PubMed

    Loomis, W F; Magasanik, B

    1967-04-01

    Growth of Escherichia coli in medium containing glucose, at a concentration insufficient to support full growth, and containing lactose, is diauxic. A mutation in the gene, CR, which determines catabolite repression specific to the lac operon, was found to relieve glucose-lactose but not glucose-maltose diauxie. Furthermore, a high concentration of lactose was shown to overcome diauxie in a CR(+) strain. Studies on the induction of beta-galactosidase by lactose suggested that glucose inhibits induction by 10(-2)m lactose. Preinduction of the lac operon was found to overcome this effect. The ability of glucose to prevent expression of the lac operon by reducing the internal concentration of inducer as well as by catabolite repression is discussed. PMID:5340309

  15. Diurnal Variation in Response to Intravenous Glucose*

    PubMed Central

    Whichelow, Margaret J.; Sturge, R. A.; Keen, H.; Jarrett, R. J.; Stimmler, L.; Grainger, Susan

    1974-01-01

    Intravenous glucose tolerance tests (25 g) were performed in the morning and afternoon on 13 apparently normal persons. The individual K values (rate of decline of blood sugar) were all higher in the morning tests, and the mean values were significantly higher in the morning. Fasting blood sugar levels were slightly lower in the afternoon. There was no difference between the fasting morning and afternoon plasma insulin levels, but the levels after glucose were lower in the afternoon. Growth hormone levels were low at all times in non-apprehensive subjects and unaffected by glucose. The results suggest that the impaired afternoon intravenous glucose tolerance, like oral glucose tolerance, is associated with impaired insulin release and insulin resistance. PMID:4817160

  16. Cell Based Metabolic Barriers to Glucose Diffusion: Macrophages and Continuous Glucose Monitoring

    PubMed Central

    Klueh, Ulrike; Frailey, Jackman; Qiao, Yi; Antar, Omar; Kreutzer, Donald L.

    2014-01-01

    It is assumed that MQ are central to glucose sensor bio-fouling and therefore have a major negative impact on continuous glucose monitoring (CGM) performance in vivo. However to our knowledge there is no data in the literature to directly support or refute this assumption. Since glucose and oxygen (O2) are key to glucose sensor function in vivo, understanding and controlling glucose and O2 metabolic activity of MQ is likely key to successful glucose sensor performance. We hypothesized that the accumulation of MQ at the glucose sensor-tissue interface will act as “Cell Based Metabolic Barriers” (CBMB) to glucose diffusing from the interstitial tissue compartment to the implanted glucose sensor and as such creating an artificially low sensor output, thereby compromising sensor function and CGM. Our studies demonstrated that 1) direct injections of MQ at in vivo sensor implantation sites dramatically decreased sensor output (measured in nA), 2) addition of MQ to glucose sensors in vitro resulted in a rapid and dramatic fall in sensor output and 3) lymphocytes did not affect sensor function in vitro or in vivo. These data support our hypothesis that MQ can act as metabolic barriers to glucose and O2 diffusion in vivo and in vitro. PMID:24461328

  17. Radiometric assays for glycerol, glucose, and glycogen.

    PubMed

    Bradley, D C; Kaslow, H R

    1989-07-01

    We have developed radiometric assays for small quantities of glycerol, glucose and glycogen, based on a technique described by Thorner and Paulus (1971, J. Biol. Chem. 246, 3885-3894) for the measurement of glycerokinase activity. In the glycerol assay, glycerol is phosphorylated with [32P]ATP and glycerokinase, residual [32P]ATP is hydrolyzed by heating in acid, and free [32P]phosphate is removed by precipitation with ammonium molybdate and triethylamine. Standard dose-response curves were linear from 50 to 3000 pmol glycerol with less than 3% SD in triplicate measurements. Of the substances tested for interference, only dihydroxyacetone gave a slight false positive signal at high concentration. When used to measure glycerol concentrations in serum and in media from incubated adipose tissue, the radiometric glycerol assay correlated well with a commonly used spectrophotometric assay. The radiometric glucose assay is similar to the glycerol assay, except that glucokinase is used instead of glycerokinase. Dose response was linear from 5 to 3000 pmol glucose with less than 3% SD in triplicate measurements. Glucosamine and N-acetylglucosamine gave false positive signals when equimolar to glucose. When glucose concentrations in serum were measured, the radiometric glucose assay agreed well with hexokinase/glucose-6-phosphate dehydrogenase (H/GDH)-based and glucose oxidase/H2O2-based glucose assays. The radiometric method for glycogen measurement incorporates previously described isolation and digestion techniques, followed by the radiometric assay of free glucose. When used to measure glycogen in mouse epididymal fat pads, the radiometric glycogen assay correlated well with the H/GDH-based glycogen assay. All three radiometric assays offer several practical advantages over spectral assays. PMID:2817333

  18. Identification of Glucose Transporters in Aspergillus nidulans

    PubMed Central

    dos Reis, Thaila Fernanda; Menino, João Filipe; Bom, Vinícius Leite Pedro; Brown, Neil Andrew; Colabardini, Ana Cristina; Savoldi, Marcela; Goldman, Maria Helena S.; Rodrigues, Fernando; Goldman, Gustavo Henrique

    2013-01-01

    To characterize the mechanisms involved in glucose transport, in the filamentous fungus Aspergillus nidulans, we have identified four glucose transporter encoding genes hxtB-E. We evaluated the ability of hxtB-E to functionally complement the Saccharomyces cerevisiae EBY.VW4000 strain that is unable to grow on glucose, fructose, mannose or galactose as single carbon source. In S. cerevisiae HxtB-E were targeted to the plasma membrane. The expression of HxtB, HxtC and HxtE was able to restore growth on glucose, fructose, mannose or galactose, indicating that these transporters accept multiple sugars as a substrate through an energy dependent process. A tenfold excess of unlabeled maltose, galactose, fructose, and mannose were able to inhibit glucose uptake to different levels (50 to 80 %) in these s. cerevisiae complemented strains. Moreover, experiments with cyanide-m-chlorophenylhydrazone (CCCP), strongly suggest that hxtB, -C, and –E mediate glucose transport via active proton symport. The A. nidulans ΔhxtB, ΔhxtC or ΔhxtE null mutants showed ~2.5-fold reduction in the affinity for glucose, while ΔhxtB and -C also showed a 2-fold reduction in the capacity for glucose uptake. The ΔhxtD mutant had a 7.8-fold reduction in affinity, but a 3-fold increase in the capacity for glucose uptake. However, only the ΔhxtB mutant strain showed a detectable decreased rate of glucose consumption at low concentrations and an increased resistance to 2-deoxyglucose. PMID:24282591

  19. Radiometric assays for glycerol, glucose, and glycogen

    SciTech Connect

    Bradley, D.C.; Kaslow, H.R. )

    1989-07-01

    We have developed radiometric assays for small quantities of glycerol, glucose and glycogen, based on a technique described by Thorner and Paulus for the measurement of glycerokinase activity. In the glycerol assay, glycerol is phosphorylated with (32P)ATP and glycerokinase, residual (32P)ATP is hydrolyzed by heating in acid, and free (32P)phosphate is removed by precipitation with ammonium molybdate and triethylamine. Standard dose-response curves were linear from 50 to 3000 pmol glycerol with less than 3% SD in triplicate measurements. Of the substances tested for interference, only dihydroxyacetone gave a slight false positive signal at high concentration. When used to measure glycerol concentrations in serum and in media from incubated adipose tissue, the radiometric glycerol assay correlated well with a commonly used spectrophotometric assay. The radiometric glucose assay is similar to the glycerol assay, except that glucokinase is used instead of glycerokinase. Dose response was linear from 5 to 3000 pmol glucose with less than 3% SD in triplicate measurements. Glucosamine and N-acetylglucosamine gave false positive signals when equimolar to glucose. When glucose concentrations in serum were measured, the radiometric glucose assay agreed well with hexokinase/glucose-6-phosphate dehydrogenase (H/GDH)-based and glucose oxidase/H2O2-based glucose assays. The radiometric method for glycogen measurement incorporates previously described isolation and digestion techniques, followed by the radiometric assay of free glucose. When used to measure glycogen in mouse epididymal fat pads, the radiometric glycogen assay correlated well with the H/GDH-based glycogen assay. All three radiometric assays offer several practical advantages over spectral assays.

  20. 76 FR 66925 - Guidance for 1-Hour SO2

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-10-28

    ... whose disclosure is restricted by statute. Do not submit information that you consider to be CBI or... boxed information. Instructions: Direct your comments to Docket ID No. EPA-HQ-OAR- 2010-1059. The EPA's... available online at http://www.regulations.gov , including any personal information provided, unless...

  1. Evaluation of Correlation of Blood Glucose and Salivary Glucose Level in Known Diabetic Patients

    PubMed Central

    Singh, Siddharth Kumar; Padmavathi, B.N.; Rajan, S.Y.; Mamatha, G.P.; Kumar, Sandeep; Roy, Sayak; Sareen, Mohit

    2015-01-01

    Introduction Diabetes mellitus is a chronic heterogenous disease in which there is dysregulation of carbohydrates, protein and lipid metabolism; leading to elevated blood glucose levels. The present study was conducted to evaluate the correlation between blood glucose and salivary glucose levels in known diabetic patients and control group and also to evaluate salivary glucose level as a diagnostic tool in diabetic patients. Materials and Methods A total number of 250 patients were studied, out of which 212 formed the study group and 38 formed the control group. Result Among 250 patients, correlation was evaluated between blood glucose and salivary glucose values which on analysis revealed Pearson correlation of 0.073. The p-value was 0.247, which was statistically non significant. Conclusion Salivary glucose values cannot be considered as a diagnostic tool for diabetic individuals. PMID:26155553

  2. Potentiometric measurement of glucose concentration with an immobilized glucose oxidase/catalase electrode.

    PubMed

    Wingard, L B; Liu, C C; Wolfson, S K; Yao, S J; Drash, A L

    1982-01-01

    A series of enzyme electrodes for measurement of glucose have been constructed. The electrodes contain glucose oxidase immobilized on platinum, either with or without co-immobilization of catalase. When placed in buffered glucose, the enzyme electrodes show a potentiometric response to glucose with respect to a Ag/AgCl reference electrode. This response is reproducible in the physiologic range of glucose concentrations. The immobilization technique, some of the environmental variables such as oxygen concentration and pH, and several compounds that might interfere with the selectivity of the enzyme electrodes for glucose have received preliminary study. This direct potentiometric approach is undergoing further evaluation to determine the basic electrochemical mechanism responsible for the potentiometric signal and whether it can be adapted for continuous in vivo monitoring of the glucose concentration in body fluids. PMID:7172983

  3. A glucose oxidase-coupled DNAzyme sensor for glucose detection in tears and saliva.

    PubMed

    Liu, Chengcheng; Sheng, Yongjie; Sun, Yanhong; Feng, Junkui; Wang, Shijin; Zhang, Jin; Xu, Jiacui; Jiang, Dazhi

    2015-08-15

    Biosensors have been widely investigated and utilized in a variety of fields ranging from environmental monitoring to clinical diagnostics. Glucose biosensors have triggered great interest and have been widely exploited since glucose determination is essential for diabetes diagnosis. In here, we designed a novel dual-enzyme biosensor composed of glucose oxidase (GOx) and pistol-like DNAzyme (PLDz) to detect glucose levels in tears and saliva. First, GOx, as a molecular recognition element, catalyzes the oxidation of glucose forming H2O2; then PLDz recognizes the produced H2O2 as a secondary signal and performs a self-cleavage reaction promoted by Mn(2+), Co(2+) and Cu(2+). Thus, detection of glucose could be realized by monitoring the cleavage rate of PLDz. The slope of the cleavage rate of PLDz versus glucose concentration curve was fitted with a Double Boltzmann equation, with a range of glucose from 100 nM to 10mM and a detection limit of 5 μM. We further applied the GOx-PLDz 1.0 biosensor for glucose detection in tears and saliva, glucose levels in which are 720±81 μM and 405±56 μM respectively. Therefore, the GOx-PLDz 1.0 biosensor is able to determine glucose levels in tears and saliva as a noninvasive glucose biosensor, which is important for diabetic patients with frequent/continuous glucose monitoring requirements. In addition, induction of DNAzyme provides a new approach in the development of glucose biosensors. PMID:25863343

  4. Glucose uptake saturation explains glucose kinetics profiles measured by different tests.

    PubMed

    Bizzotto, Roberto; Natali, Andrea; Gastaldelli, Amalia; Muscelli, Elza; Krssak, Martin; Brehm, Attila; Roden, Michael; Ferrannini, Ele; Mari, Andrea

    2016-08-01

    It is known that for a given insulin level glucose clearance depends on glucose concentration. However, a quantitative representation of the concomitant effects of hyperinsulinemia and hyperglycemia on glucose clearance, necessary to describe heterogeneous tests such as euglycemic and hyperglycemic clamps and oral tests, is lacking. Data from five studies (123 subjects) using a glucose tracer and including all the above tests in normal and diabetic subjects were collected. A mathematical model was developed in which glucose utilization was represented as a Michaelis-Menten function of glucose with constant Km and insulin-controlled Vmax, consistently with the basic notions of glucose transport. Individual values for the model parameters were estimated using a population approach. Tracer data were accurately fitted in all tests. The estimated Km was 3.88 (2.83-5.32) mmol/l [median (interquartile range)]. Median model-derived glucose clearance at 600 pmol/l insulin was reduced from 246 to 158 ml·min(-1)·m(-2) when glucose was raised from 5 to 10 mmol/l. The model reproduced the characteristic lack of increase in glucose clearance when moderate hyperinsulinemia was accompanied by hyperglycemia. In all tests, insulin sensitivity was inversely correlated with BMI, as expected (R(2) = 0.234, P = 0.0001). In conclusion, glucose clearance in euglycemic and hyperglycemic clamps and oral tests can be described with a unifying model, consistent with the notions of glucose transport and able to reproduce the suppression of glucose clearance due to hyperglycemia observed in previous studies. The model may be important for the design of reliable glucose homeostasis simulators. PMID:27245333

  5. Noninvasive glucose sensing by transcutaneous Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Shih, Wei-Chuan; Bechtel, Kate L.; Rebec, Mihailo V.

    2015-05-01

    We present the development of a transcutaneous Raman spectroscopy system and analysis algorithm for noninvasive glucose sensing. The instrument and algorithm were tested in a preclinical study in which a dog model was used. To achieve a robust glucose test system, the blood levels were clamped for periods of up to 45 min. Glucose clamping and rise/fall patterns have been achieved by injecting glucose and insulin into the ear veins of the dog. Venous blood samples were drawn every 5 min and a plasma glucose concentration was obtained and used to maintain the clamps, to build the calibration model, and to evaluate the performance of the system. We evaluated the utility of the simultaneously acquired Raman spectra to be used to determine the plasma glucose values during the 8-h experiment. We obtained prediction errors in the range of ˜1.5-2 mM. These were in-line with a best-case theoretical estimate considering the limitations of the signal-to-noise ratio estimates. As expected, the transition regions of the clamp study produced larger predictive errors than the stable regions. This is related to the divergence of the interstitial fluid (ISF) and plasma glucose values during those periods. Two key contributors to error beside the ISF/plasma difference were photobleaching and detector drift. The study demonstrated the potential of Raman spectroscopy in noninvasive applications and provides areas where the technology can be improved in future studies.

  6. Exercising Tactically for Taming Postmeal Glucose Surges

    PubMed Central

    Chacko, Elsamma

    2016-01-01

    This review seeks to synthesize data on the timing, intensity, and duration of exercise found scattered over some 39 studies spanning 3+ decades into optimal exercise conditions for controlling postmeal glucose surges. The results show that a light aerobic exercise for 60 min or moderate activity for 20–30 min starting 30 min after meal can efficiently blunt the glucose surge, with minimal risk of hypoglycemia. Exercising at other times could lead to glucose elevation caused by counterregulation. Adding a short bout of resistance exercise of moderate intensity (60%–80%  VO2max) to the aerobic activity, 2 or 3 times a week as recommended by the current guidelines, may also help with the lowering of glucose surges. On the other hand, high-intensity exercise (>80%  VO2max) causes wide glucose fluctuations and its feasibility and efficacy for glucose regulation remain to be ascertained. Promoting the kind of physical activity that best counters postmeal hyperglycemia is crucial because hundreds of millions of diabetes patients living in developing countries and in the pockets of poverty in the West must do without medicines, supplies, and special diets. Physical activity is the one tool they may readily utilize to tame postmeal glucose surges. Exercising in this manner does not violate any of the current guidelines, which encourage exercise any time. PMID:27073714

  7. Noninvasive glucose sensing by transcutaneous Raman spectroscopy

    PubMed Central

    Shih, Wei-Chuan; Bechtel, Kate L.; Rebec, Mihailo V.

    2015-01-01

    Abstract. We present the development of a transcutaneous Raman spectroscopy system and analysis algorithm for noninvasive glucose sensing. The instrument and algorithm were tested in a preclinical study in which a dog model was used. To achieve a robust glucose test system, the blood levels were clamped for periods of up to 45 min. Glucose clamping and rise/fall patterns have been achieved by injecting glucose and insulin into the ear veins of the dog. Venous blood samples were drawn every 5 min and a plasma glucose concentration was obtained and used to maintain the clamps, to build the calibration model, and to evaluate the performance of the system. We evaluated the utility of the simultaneously acquired Raman spectra to be used to determine the plasma glucose values during the 8-h experiment. We obtained prediction errors in the range of ∼1.5−2  mM. These were in-line with a best-case theoretical estimate considering the limitations of the signal-to-noise ratio estimates. As expected, the transition regions of the clamp study produced larger predictive errors than the stable regions. This is related to the divergence of the interstitial fluid (ISF) and plasma glucose values during those periods. Two key contributors to error beside the ISF/plasma difference were photobleaching and detector drift. The study demonstrated the potential of Raman spectroscopy in noninvasive applications and provides areas where the technology can be improved in future studies. PMID:25688542

  8. Exercising Tactically for Taming Postmeal Glucose Surges.

    PubMed

    Chacko, Elsamma

    2016-01-01

    This review seeks to synthesize data on the timing, intensity, and duration of exercise found scattered over some 39 studies spanning 3+ decades into optimal exercise conditions for controlling postmeal glucose surges. The results show that a light aerobic exercise for 60 min or moderate activity for 20-30 min starting 30 min after meal can efficiently blunt the glucose surge, with minimal risk of hypoglycemia. Exercising at other times could lead to glucose elevation caused by counterregulation. Adding a short bout of resistance exercise of moderate intensity (60%-80%  VO2max) to the aerobic activity, 2 or 3 times a week as recommended by the current guidelines, may also help with the lowering of glucose surges. On the other hand, high-intensity exercise (>80%  VO2max) causes wide glucose fluctuations and its feasibility and efficacy for glucose regulation remain to be ascertained. Promoting the kind of physical activity that best counters postmeal hyperglycemia is crucial because hundreds of millions of diabetes patients living in developing countries and in the pockets of poverty in the West must do without medicines, supplies, and special diets. Physical activity is the one tool they may readily utilize to tame postmeal glucose surges. Exercising in this manner does not violate any of the current guidelines, which encourage exercise any time. PMID:27073714

  9. Taeniid tapeworm responses to in vitro glucose.

    PubMed

    Willms, Kaethe; Presas, Ana María Fernández; Jiménez, José Agustín; Landa, Abraham; Zurabián, Rimma; Ugarte, María Eugenia Juárez; Robert, Lilia

    2005-07-01

    Experimental taeniid strobilae from Taenia solium and T. crassiceps (WFU strain) were incubated for 0-72 h in 0, 5 or 20 mM glucose solutions and further exposed for 15 min to the gap junction fluorochrome Lucifer Yellow. Frozen sections were obtained from each worm and observed under an epifluorescent microscope. Worm sections from strobilae incubated with glucose, revealed intense fluorescence in the base of the tegumentary surface, suggesting that this tissue behaves as a gap junction complex. Fluorescence intensity differences between control worms not exposed to glucose and worms incubated with glucose, were highly significant. The results demonstrate that under in vitro conditions, glucose is taken up along the whole strobilar tegument in both taeniid species, suggesting, that although taeniids attached to the duodenum probably take up most of their nutrients directly from the mucosal wall, the capacity for absorbing glucose along the tegumentary surface is always active and may increase the survival capacity of these intestinal worms by promoting glucose absorption at other points in the intestinal lumen. PMID:15918070

  10. Blood-Brain Glucose Transfer: Repression in Chronic Hyperglycemia

    NASA Astrophysics Data System (ADS)

    Gjedde, Albert; Crone, Christian

    1981-10-01

    Diabetic patients with increased plasma glucose concentrations may develop cerebral symptoms of hypoglycemia when their plasma glucose is rapidly lowered to normal concentrations. The symptoms may indicate insufficient transport of glucose from blood to brain. In rats with chronic hyperglycemia the maximum glucose transport capacity of the blood-brain barrier decreased from 400 to 290 micromoles per 100 grams per minute. When plasma glucose was lowered to normal values, the glucose transport rate into brain was 20 percent below normal. This suggests that repressive changes of the glucose transport mechanism occur in brain endothelial cells in response to increased plasma glucose.

  11. Hepatic Carboxylesterase 1 Is Induced by Glucose and Regulates Postprandial Glucose Levels

    PubMed Central

    Xu, Jiesi; Yin, Liya; Xu, Yang; Li, Yuanyuan; Zalzala, Munaf; Cheng, Gang; Zhang, Yanqiao

    2014-01-01

    Metabolic syndrome, characterized by obesity, hyperglycemia, dyslipidemia and hypertension, increases the risks for cardiovascular disease, diabetes and stroke. Carboxylesterase 1 (CES1) is an enzyme that hydrolyzes triglycerides and cholesterol esters, and is important for lipid metabolism. Our previous data show that over-expression of mouse hepatic CES1 lowers plasma glucose levels and improves insulin sensitivity in diabetic ob/ob mice. In the present study, we determined the physiological role of hepatic CES1 in glucose homeostasis. Hepatic CES1 expression was reduced by fasting but increased in diabetic mice. Treatment of mice with glucose induced hepatic CES1 expression. Consistent with the in vivo study, glucose stimulated CES1 promoter activity and increased acetylation of histone 3 and histone 4 in the CES1 chromatin. Knockdown of ATP-citrate lyase (ACL), an enzyme that regulates histone acetylation, abolished glucose-mediated histone acetylation in the CES1 chromatin and glucose-induced hepatic CES1 expression. Finally, knockdown of hepatic CES1 significantly increased postprandial blood glucose levels. In conclusion, the present study uncovers a novel glucose-CES1-glucose pathway which may play an important role in regulating postprandial blood glucose levels. PMID:25285996

  12. Resistin modulates glucose uptake and glucose transporter-1 (GLUT-1) expression in trophoblast cells

    PubMed Central

    Di Simone, Nicoletta; Di Nicuolo, Fiorella; Marzioni, Daniela; Castellucci, Mario; Sanguinetti, Maurizio; D’lppolito, Silvia; Caruso, Alessandro

    2009-01-01

    Abstract The adipocytokine resistin impairs glucose tolerance and insulin sensitivity. Here, we examine the effect of resistin on glucose uptake in human trophoblast cells and we demonstrate that transplacental glucose transport is mediated by glucose transporter (GLUT)-1. Furthermore, we evaluate the type of signal transduction induced by resistin in GLUT-1 regulation. BeWo choriocarcinoma cells and primary cytotrophoblast cells were cultured with increasing resistin concentrations for 24 hrs. The main outcome measures include glucose transport assay using [3H]-2-deoxy glucose, GLUT-1 protein expression by Western blot analysis and GLUT-1 mRNA detection by quantitative real-time RT-PCR. Quantitative determination of phospho(p)-ERK1/2 in cell lysates was performed by an Enzyme Immunometric Assay and Western blot analysis. Our data demonstrate a direct effect of resistin on normal cytotrophoblastic and on BeWo cells: resistin modulates glucose uptake, GLUT-1 messenger ribonucleic acid (mRNA) and protein expression in placental cells. We suggest that ERK1/2 phosphorylation is involved in the GLUT-1 regulation induced by resistin. In conclusion, resistin causes activation of both the ERK1 and 2 pathway in trophoblast cells. ERK1 and 2 activation stimulated GLUT-1 synthesis and resulted in increase of placental glucose uptake. High resistin levels (50–100 ng/ml) seem able to affect glucose-uptake, presumably by decreasing the cell surface glucose transporter. PMID:18410529

  13. Glucose Homeostatic Law: Insulin Clearance Predicts the Progression of Glucose Intolerance in Humans

    PubMed Central

    Uda, Shinsuke; Kubota, Hiroyuki; Iwaki, Toshinao; Fukuzawa, Hiroki; Komori, Yasunori; Fujii, Masashi; Toyoshima, Yu; Sakaguchi, Kazuhiko; Ogawa, Wataru; Kuroda, Shinya

    2015-01-01

    Homeostatic control of blood glucose is regulated by a complex feedback loop between glucose and insulin, of which failure leads to diabetes mellitus. However, physiological and pathological nature of the feedback loop is not fully understood. We made a mathematical model of the feedback loop between glucose and insulin using time course of blood glucose and insulin during consecutive hyperglycemic and hyperinsulinemic-euglycemic clamps in 113 subjects with variety of glucose tolerance including normal glucose tolerance (NGT), impaired glucose tolerance (IGT) and type 2 diabetes mellitus (T2DM). We analyzed the correlation of the parameters in the model with the progression of glucose intolerance and the conserved relationship between parameters. The model parameters of insulin sensitivity and insulin secretion significantly declined from NGT to IGT, and from IGT to T2DM, respectively, consistent with previous clinical observations. Importantly, insulin clearance, an insulin degradation rate, significantly declined from NGT, IGT to T2DM along the progression of glucose intolerance in the mathematical model. Insulin clearance was positively correlated with a product of insulin sensitivity and secretion assessed by the clamp analysis or determined with the mathematical model. Insulin clearance was correlated negatively with postprandial glucose at 2h after oral glucose tolerance test. We also inferred a square-law between the rate constant of insulin clearance and a product of rate constants of insulin sensitivity and secretion in the model, which is also conserved among NGT, IGT and T2DM subjects. Insulin clearance shows a conserved relationship with the capacity of glucose disposal among the NGT, IGT and T2DM subjects. The decrease of insulin clearance predicts the progression of glucose intolerance. PMID:26623647

  14. Postprandial glucose and insulin profiles following a glucose-loaded meal in cats and dogs.

    PubMed

    Hewson-Hughes, Adrian K; Gilham, Matthew S; Upton, Sarah; Colyer, Alison; Butterwick, Richard; Miller, Andrew T

    2011-10-01

    Data from intravenous (i.v.) glucose tolerance tests suggest that glucose clearance from the blood is slower in cats than in dogs. Since different physiological pathways are activated following oral administration compared with i.v. administration, we investigated the profiles of plasma glucose and insulin in cats and dogs following ingestion of a test meal with or without glucose. Adult male and female cats and dogs were fed either a high-protein (HP) test meal (15 g/kg body weight; ten cats and eleven dogs) or a HP + glucose test meal (13 g/kg body-weight HP diet + 2 g/kg body-weight D-glucose; seven cats and thirteen dogs) following a 24 h fast. Marked differences in plasma glucose and insulin profiles were observed in cats and dogs following ingestion of the glucose-loaded meal. In cats, mean plasma glucose concentration reached a peak at 120 min (10.2, 95 % CI 9.7, 10.8 mmol/l) and returned to baseline by 240 min, but no statistically significant change in plasma insulin concentration was observed. In dogs, mean plasma glucose concentration reached a peak at 60 min (6.3, 95 % CI 5.9, 6.7 mmol/l) and returned to baseline by 90 min, while plasma insulin concentration was significantly higher than pre-meal values from 30 to 120 min following the glucose-loaded meal. These results indicate that cats are not as efficient as dogs at rapidly decreasing high blood glucose levels and are consistent with a known metabolic adaptation of cats, namely a lack of glucokinase, which is important for both insulin secretion and glucose uptake from the blood. PMID:22005400

  15. Single Cell "Glucose Nanosensor" Verifies Elevated Glucose Levels in Individual Cancer Cells.

    PubMed

    Nascimento, Raphael A S; Özel, Rıfat Emrah; Mak, Wai Han; Mulato, Marcelo; Singaram, Bakthan; Pourmand, Nader

    2016-02-10

    Because the transition from oxidative phosphorylation to anaerobic glycolytic metabolism is a hallmark of cancer progression, approaches to identify single living cancer cells by their unique glucose metabolic signature would be useful. Here, we present nanopipettes specifically developed to measure glucose levels in single cells with temporal and spatial resolution, and we use this technology to verify the hypothesis that individual cancer cells can indeed display higher intracellular glucose levels. The nanopipettes were functionalized as glucose nanosensors by immobilizing glucose oxidase (GOx) covalently to the tip so that the interaction of glucose with GOx resulted in a catalytic oxidation of β-d-glucose to d-gluconic acid, which was measured as a change in impedance due to drop in pH of the medium at the nanopipette tip. Calibration studies showed a direct relationship between impedance changes at the tip and glucose concentration in solution. The glucose nanosensor quantified single cell intracellular glucose levels in human fibroblasts and the metastatic breast cancer lines MDA-MB-231 and MCF7 and revealed that the cancer cells expressed reproducible and reliable increases in glucose levels compared to the nonmalignant cells. Nanopipettes allow repeated sampling of the same cell, as cells remain viable during and after measurements. Therefore, nanopipette-based glucose sensors provide an approach to compare changes in glucose levels with changes in proliferative or metastatic state. The platform has great promise for mechanistic investigations, as a diagnostic tool to distinguish cancer cells from nonmalignant cells in heterogeneous tissue biopsies, as well as a tool for monitoring cancer progression in situ. PMID:26752097

  16. Glucose and fructose metabolism in Zymomonas anaerobia

    PubMed Central

    McGill, D. J.; Dawes, E. A.

    1971-01-01

    Isotopic and enzymic evidence indicates that Zymomonas anaerobia ferments glucose via the Entner–Doudoroff pathway. The molar growth yields with glucose (5.89) and fructose (5.0) are lower than those for the related organism Zymomonas mobilis and the observed linear growth suggests that energetically uncoupled growth occurs. A survey of enzymes of carbohydrate metabolism revealed the presence of weak phosphofructokinase and fructose 1,6-diphosphate aldolase activities but phosphoketolase, transketolase and transaldolase were not detected. Fermentation balances for glucose and fructose are reported; acetaldehyde accumulated in both fermentations, to a greater extent with fructose which also yielded glycerol and dihydroxyacetone as minor products. PMID:4259336

  17. Role of glucose signaling in yeast metabolism

    SciTech Connect

    Dam, K. van

    1996-10-05

    The conversion of glucose to ethanol and carbon dioxide by yeast was the first biochemical pathway to be studied in detail. The initial observation that this process is catalyzed by an extract of yeast led to the discovery of enzymes and coenzymes and laid the foundation for modern biochemistry. In this article, knowledge concerning the relation between uptake of and signaling by glucose in the yeast Saccharomyces cerevisiae is reviewed and compared to the analogous process in prokaryotes. It is concluded that (much) more fundamental knowledge concerning these processes is required before rational redesign of metabolic fluxes from glucose in yeast can be achieved.

  18. [Microbial production of glucose/fructose syrups].

    PubMed

    Matur, A; Sağlam, N

    1982-04-01

    With the ever-increasing demand for sugar and the trend in rising price, rapid progress in research on new and/or alternative sweeteners has been inevitable during the past decade or so. Pure glucose, glucose/fructose, glucose/maltose syrups are often called "isosyrups". Isosyrups have been recognized as a good alternative sources of sugar. These are used today in the manufacture of soft drinks, jams and jellies, confectionary, baking fermentation, dietetic and infant food, ice-cream, pharmaceutical processes, etc. Isosyrups are produced by hydrolysis of starch and cellulocis raw materials have been utilized for the production of isosyrups. PMID:7144624

  19. Optimal glucose management in the perioperative period.

    PubMed

    Evans, Charity H; Lee, Jane; Ruhlman, Melissa K

    2015-04-01

    Hyperglycemia is a common finding in surgical patients during the perioperative period. Factors contributing to poor glycemic control include counterregulatory hormones, hepatic insulin resistance, decreased insulin-stimulated glucose uptake, use of dextrose-containing intravenous fluids, and enteral and parenteral nutrition. Hyperglycemia in the perioperative period is associated with increased morbidity, decreased survival, and increased resource utilization. Optimal glucose management in the perioperative period contributes to reduced morbidity and mortality. To readily identify hyperglycemia, blood glucose monitoring should be instituted for all hospitalized patients. PMID:25814110

  20. Designing a highly active soluble PQQ-glucose dehydrogenase for efficient glucose biosensors and biofuel cells

    SciTech Connect

    Durand, Fabien; Stines-Chaumeil, Claire; Flexer, Victoria; Andre, Isabelle; Mano, Nicolas

    2010-11-26

    Research highlights: {yields} A new mutant of PQQ-GDH designed for glucose biosensors application. {yields} First mutant of PQQ-GDH with higher activity for D-glucose than the Wild type. {yields} Position N428 is a key point to increase the enzyme activity. {yields} Molecular modeling shows that the N428 C mutant displays a better interaction for PQQ than the WT. -- Abstract: We report for the first time a soluble PQQ-glucose dehydrogenase that is twice more active than the wild type for glucose oxidation and was obtained by combining site directed mutagenesis, modelling and steady-state kinetics. The observed enhancement is attributed to a better interaction between the cofactor and the enzyme leading to a better electron transfer. Electrochemical experiments also demonstrate the superiority of the new mutant for glucose oxidation and make it a promising enzyme for the development of high-performance glucose biosensors and biofuel cells.

  1. A glucose-centric perspective of hyperglycemia.

    PubMed

    Ramasarma, T; Rafi, M

    2016-02-01

    Digestion of food in the intestines converts the compacted storage carbohydrates, starch and glycogen, to glucose. After each meal, a flux of glucose (> 200 g) passes through the blood pool (4-6 g) in a short period of 2 h, keeping its concentration ideally in the range of 80-120 mg/100 mL. Tissue-specific glucose transporters (GLUTs) aid in the distribution of glucose to all tissues. The balance glucose after meeting the immediate energy needs is converted into glycogen and stored in liver (up to 100 g) and skeletal muscle (up to 300 g) for later use. High blood glucose gives the signal for increased release of insulin from pancreas. Insulin binds to insulin receptor on the plasma membrane and activates its autophosphorylation. This initiates the post-insulin-receptor signal cascade that accelerates synthesis of glycogen and triglyceride. Parallel control by phos-dephos and redox regulation of proteins exists for some of these steps. A major action of insulin is to inhibit gluconeogensis in the liver decreasing glucose output into blood. Cases with failed control of blood glucose have alarmingly increased since 1960 coinciding with changed life-styles and large scale food processing. Many of these turned out to be resistant to insulin, usually accompanied by dysfunctional glycogen storage. Glucose has an extended stay in blood at 8 mM and above and then indiscriminately adds on to surface protein-amino groups. Fructose in common sugar is 10-fold more active. This random glycation process interferes with the functions of many proteins (e.g., hemoglobin, eye lens proteins) and causes progressive damage to heart, kidneys, eyes and nerves. Some compounds are known to act as insulin mimics. Vanadium-peroxide complexes act at post-receptor level but are toxic. The fungus-derived 2,5-dihydroxybenzoquinone derivative is the first one known to act on the insulin receptor. The safe herbal products in use for centuries for glucose control have multiple active principles and

  2. Genetics Home Reference: glucose-galactose malabsorption

    MedlinePlus

    ... mutations in SGLT1 cause glucose-galactose malabsorption by trafficking defects. Biochim Biophys Acta. 1999 Feb 24;1453( ... Accessibility FOIA Viewers & Players U.S. Department of Health & Human Services National Institutes of Health National Library of ...

  3. Glucose loading and dehydration in the camel.

    PubMed

    Yagil, R; Berlyne, G M

    1977-05-01

    Five female bedouin camels were subjected to large infusions of glucose, both when water was readily available and following 10 days of water deprivation. When the camels were hydrated the extra glucose was readily given off in the urine with only a slight increase in blood levels. Following dehydration, the blood glucose levels increased greatly while the urinary excretion was limited. Dehydration led to decreased blood insulin levels, while glucose infusion led to increased levels. The data show that the acclimatization of the camel to dehydration is not only a question of long-term adaption to desert conditions but that even following acute nonphysiological stress, i.e., glucosuria, excess loss of body water was prevented. PMID:863833

  4. Pulmonary glucose transport in the fetal sheep.

    PubMed Central

    Barker, P M; Boyd, C A; Ramsden, C A; Strang, L B; Walters, D V

    1989-01-01

    1. In the chronically catheterized sheep fetus between 122 and 143 days gestation the concentration of D-glucose in lung liquid was very low (usually less than 0.01 mM, the lower limit of detection of the analytical method) whereas the mean plasma concentration was 0.19 mM (S.E.M. 0.4, n = 13). 2. When the lung liquid concentration of D-glucose was raised to 1.67-5.00 mM, rapid uptake was observed until the concentration had fallen to its preceding low level. The uptake showed saturation kinetics (Vmax = 2.29-8.78 mumol/min, increasing with gestation; mean Km = 0.14 +/- 0.02 mM, n = 11, no change with gestation). This active uptake of glucose was blocked by phloridzin (10(-4) M). It was associated with a decrease in lung liquid secretion rate from which a change in net sodium flux could be inferred of an order suggesting one-to-one glucose-sodium co-transport. 3. Radiolabelled 3-O-methyl-D-glucose (3-O-meG) - a monosaccharide which is transported but not metabolized - was taken up rapidly from lung liquid and this rapid uptake was inhibited by D-glucose with 50% inhibition at 0.35 mM (+/- 0.08, n = 9). It was also inhibited by phloridzin (10(-4) M). 4. Radiolabelled 2-deoxy-D-glucose - a monosaccharide which is not a substrate for sodium-coupled transport - was taken up only very slowly from lung liquid; the rate of uptake was appropriate for passive diffusional transport and it was unaffected by the addition of D-glucose or phloridzin to lung liquid. 5. Intravenous infusion of D-glucose caused no detectable increase in the concentration of glucose in lung liquid unless phloridzin was added, when a slow increase was observed. 6. In two experiments with active transport blocked by phloridzin in lung liquid (10(-4) M), the rate of entry of labelled 3-O-meG from plasma to lung liquid was measured during intravenous infusion of this tracer for 29 and 23 h. The rates of entry were similar to the rate of efflux of the tracer from lung liquid when uptake was blocked by

  5. Effects of fasting on plasma glucose and prolonged tracer measurement of hepatic glucose output in NIDDM

    SciTech Connect

    Glauber, H.; Wallace, P.; Brechtel, G.

    1987-10-01

    We studied the measurement of hepatic glucose output (HGO) with prolonged (3-/sup 3/H)glucose infusion in 14 patients with non-insulin-dependent diabetes mellitus (NIDDM). Over the course of 10.5 h, plasma glucose concentration fell with fasting by one-third, from 234 +/- 21 to 152 +/- 12 mg/dl, and HGO fell from 2.35 +/- 0.18 to 1.36 +/- 0.07 mg . kg-1 . min-1 (P less than .001). In the basal state, HGO and glucose were significantly correlated (r = 0.68, P = .03), and in individual patients, HGO and glucose were closely correlated as both fell with fasting (mean r = 0.79, P less than .01). Plasma (3-/sup 3/H)glucose radioactivity approached a steady state only 5-6 h after initiation of the primed continuous infusion, and a 20% overestimate of HGO was demonstrated by not allowing sufficient time for tracer labeling of the glucose pool. Assumption of steady-state instead of non-steady-state kinetics in using Steele's equations to calculate glucose turnover resulted in a 9-24% overestimate of HGO. Stimulation of glycogenolysis by glucagon injection demonstrated no incorporation of (3-/sup 3/H)glucose in hepatic glycogen during the prolonged tracer infusion. In a separate study, plasma glucose was maintained at fasting levels (207 +/- 17 mg/dl) for 8 h with the glucose-clamp technique. Total glucose turnover rates remained constant during this prolonged tracer infusion. However, HGO fell to 30% of the basal value simply by maintaining fasting hyperglycemia in the presence of basal insulin levels.

  6. Acid hydrolysis of cellulose to yield glucose

    DOEpatents

    Tsao, George T.; Ladisch, Michael R.; Bose, Arindam

    1979-01-01

    A process to yield glucose from cellulose through acid hydrolysis. Cellulose is recovered from cellulosic materials, preferably by pretreating the cellulosic materials by dissolving the cellulosic materials in Cadoxen or a chelating metal caustic swelling solvent and then precipitating the cellulose therefrom. Hydrolysis is accomplished using an acid, preferably dilute sulfuric acid, and the glucose is yielded substantially without side products. Lignin may be removed either before or after hydrolysis.

  7. 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.

  8. Glucose as substrate and signal in priming: Results from experiments with non-metabolizable glucose analogues

    NASA Astrophysics Data System (ADS)

    Mason-Jones, Kyle; Kuzyakov, Yakov

    2016-04-01

    Priming of soil organic matter remains the subject of intense research, but a mechanistic explanation of the phenomenon remains to be demonstrated. This is largely due to the multiple effects of easily available carbon on the soil microbial community, and the challenge of separating these influences from one another. Several glucose analogues can be taken up by microbial glucose transporters and have similar regulatory effects on metabolism. These substances are, however, not easily catabolized by the common glycolytic pathway, limiting their energy value. Therefore, they can be used to distinguish between the action of glucose as a metabolic signal, and its influence as an energy source. We incubated an agricultural Haplic Luvisol under controlled conditions for 24 days after addition of: 1) glucose, 2) 3-O-methyl-glucose, 3) α-methylglucoside or 4) 2-deoxyglucose, at three concentration levels, along with a control treatment of water addition. CO2 efflux from soil was monitored by trapping evolved CO2 in NaOH and back-titration with HCl. On the first day after amendment, CO2 efflux from soil increased strongly for glucose and much less for the analogues, relative to the control. Only glucose caused a peak in efflux within the first two days. Peak mineralization of 2-deoxyglucose and α-methylglucoside was delayed until the third day, while CO2 from 3-O-methyl-glucose increased gradually, with a peak delayed by approximately a week. For glucose, the immediate increase in respiration was strongly dependent on the amount of glucose added, but this was not the case for the analogues, indicating that the catabolic potential for these substances was saturated. This is consistent with only a small part of the microbial community being capable of utilizing these carbon sources. In a subsequent experiment, 14C-labelled glucose or 14C-labelled 3-O-methyl-glucose were added to the same soil, enabling quantification of the priming effect. For 3-O-methyl-glucose, priming was

  9. Sodium coupled glucose co-transporters contribute to hypothalamic glucose-sensing

    PubMed Central

    O'Malley, Dervla; Reimann, Frank; Simpson, Anna K; Gribble, Fiona M

    2007-01-01

    Specialised neurons within the hypothalamus have the ability to sense and respond to changes in ambient glucose concentrations. We investigated the mechanisms underlying glucose-triggered activity in glucose-excited (GE) neurons, using primary cultures of rat hypothalamic neurons monitored by fluorescence calcium imaging. 35% (738/2139) of neurons were excited by increasing glucose from 3 to 15mM, but only 9% (6/64) of these GE neurons were activated by tolbutamide, suggesting the involvement of a KATP channel-independent mechanism. α-Methylglucopyranoside (αMDG, 12mM), a non-metabolisable substrate of sodium glucose co-transporters (SGLTs), mimicked the effect of high glucose in 67% of GE neurons, and both glucose and αMDG-triggered excitation were blocked by Na+ removal or by the SGLT inhibitor, phloridzin (100nM). In the presence of 0.5mM glucose and tolbutamide, responses could also be triggered by 3.5mM αMDG, supporting a role for an SGLT-associated mechanism at low as well as high substrate concentrations. By RT-PCR, we detected SGLT1, SGLT3a, SGLT3b in both cultured neurons and adult rat hypothalamus. Our findings suggest a novel role for SGLTs in glucose-sensing by hypothalamic GE neurons. PMID:17130483

  10. A Glucose Sensing Contact Lens: A Non-Invasive Technique for Continuous Physiological Glucose Monitoring

    PubMed Central

    Badugu, Ramachandram; Lakowicz, Joseph R.; Geddes, Chris D.

    2016-01-01

    We have developed a range of glucose sensing contact lenses, using a daily, disposable contact lens embedded with newly developed boronic acid containing fluorophores. Our findings show that our approach may be suitable for the continuous monitoring of tear glucose levels in the range 50–1000 μM, which typically track blood glucose levels, which are ≈5–10 fold higher. Our non-invasive approach may well offer an alternative solution to current invasive glucose monitoring techniques for diabetes, such as “finger pricking.” PMID:27340364

  11. Regulation and biological function of a flagellar glucose transporter in Leishmania mexicana: a potential glucose sensor.

    PubMed

    Rodriguez-Contreras, Dayana; Aslan, Hamide; Feng, Xiuhong; Tran, Khoa; Yates, Phillip A; Kamhawi, Shaden; Landfear, Scott M

    2015-01-01

    In Leishmania mexicana parasites, a unique glucose transporter, LmxGT1, is selectively targeted to the flagellar membrane, suggesting a possible sensory role that is often associated with ciliary membrane proteins. Expression of LmxGT1 is down-regulated ∼20-fold by increasing cell density but is up-regulated ∼50-fold by depleting glucose from the medium, and the permease is strongly down-regulated when flagellated insect-stage promastigotes invade mammalian macrophages and transform into intracellular amastigotes. Regulation of LmxGT1 expression by glucose and during the lifecycle operates at the level of protein stability. Significantly, a ∆lmxgt1 null mutant, grown in abundant glucose, undergoes catastrophic loss of viability when parasites deplete glucose from the medium, a property not exhibited by wild-type or add-back lines. These results suggest that LmxGT1 may function as a glucose sensor that allows parasites to enter the stationary phase when they deplete glucose and that in the absence of this sensor, parasites do not maintain viability when they run out of glucose. However, alternate roles for LmxGT1 in monitoring glucose availability are considered. The absence of known sensory receptors with defined ligands and biologic functions in Leishmania and related kinetoplastid parasites underscores the potential significance of these observations. PMID:25300620

  12. Wireless glucose monitoring watch enabled by an implantable self-sustaining glucose sensor system

    NASA Astrophysics Data System (ADS)

    Rai, Pratyush; Varadan, Vijay K.

    2012-10-01

    Implantable glucose sensors can measure real time blood glucose as compared to conventional techniques involving drawing blood samples and in-vitro processing. An implantable sensor requires energy source for operation with wire inout provision for power and sending signals. Implants capable of generation-transmission of sensory signals, with minimal or no power requirement, can solve this problem. An implantable nanosensor design has been presented here, which can passively detect glucose concentration in blood stream and transmit data to a wearable receiver-recorder system or a watch. The glucose sensitive component is a redox pair of electrodes that generates voltage proportional to glucose concentration. The bio-electrode, made of carbon nanotubes-enzyme nanocluster, has been investigated because of the large surface area for taping electrical signals. This glucose sensor can charge a capacitor, which can be a part of a LCR resonance/inductive coupling based radio frequency (RF) sensor telemetry. Such a system can measure change in glucose concentration by the induced frequency shift in the LCR circuit. A simultaneous power transmission and signal transmission can be achieved by employing two separate LCR oscillating loops, one for each operation. The corresponding coupling LCR circuits can be housed in the wearable receiving watch unit. The data logged in this glucose monitoring watch can be instrumental in managing blood glucose as trigger for an insulin dispensing payload worn on person or implanted.

  13. Noninvasive Continuous Monitoring of Tear Glucose Using Glucose-Sensing Contact Lenses.

    PubMed

    Ascaso, Francisco J; Huerva, Valentín

    2016-04-01

    : The incidence of diabetes mellitus is dramatically increasing in the developed countries. Tight control of blood glucose concentration is crucial to diabetic patients to prevent microvascular complications. Self-monitoring of blood glucose is widely used for controlling blood glucose levels and usually performed by an invasive test using a portable glucometer. Many technologies have been developed over the past decades with the purpose of obtaining a continuous physiological glycemic monitoring. A contact lens is the ideal vehicle for continuous tear glucose monitoring of glucose concentration in tear film. There are several research groups that are working in the development of contact lenses with embedded biosensors for continuously and noninvasively monitoring tear glucose levels. Although numerous aspects must be improved, contact lens technology is one step closer to helping diabetic subjects better manage their condition, and these contact lenses will be able to measure the level of glucose in the wearer's tears and communicate the information to a mobile phone or computer. This article reviews studies on ocular glucose and its monitoring methods as well as the attempts to continuously monitor the concentration of tear glucose by using contact lens-based sensors. PMID:26390345

  14. Okara ameliorates glucose tolerance in GK rats

    PubMed Central

    Hosokawa, Masaya; Katsukawa, Michiko; Tanaka, Hiroshi; Fukuda, Hitomi; Okuno, Sonomi; Tsuda, Kinsuke; Iritani, Nobuko

    2016-01-01

    Okara, a food by-product from the production of tofu and soy milk, is rich in three beneficial components: insoluble dietary fiber, β-conglycinin, and isoflavones. Although isoflavones and β-conglycinin have recently been shown to improve glucose tolerance, the effects of okara have not yet been elucidated. Therefore, we herein investigated the effects of okara on glucose tolerance in Goto-Kakizaki (GK) rats, a representative animal model of Japanese type 2 diabetes. Male GK rats were fed a 10% lard diet with or without 5% dry okara powder for 2 weeks and an oral glucose tolerance test was performed. Rats were then fed each diet for another week and sacrificed. The expression of genes that are the master regulators of glucose metabolism in adipose tissue was subsequently examined. No significant differences were observed in body weight gain or food intake between the two groups of GK rats. In the oral glucose tolerance test, increases in plasma glucose levels were suppressed by the okara diet. The mRNA expression levels of PPARγ, adiponectin, and GLUT4, which up-regulate the effects of insulin, were increased in epididymal adipose tissue by the okara diet. These results suggest that okara provides a useful means for treating type 2 diabetes. PMID:27257347

  15. Okara ameliorates glucose tolerance in GK rats.

    PubMed

    Hosokawa, Masaya; Katsukawa, Michiko; Tanaka, Hiroshi; Fukuda, Hitomi; Okuno, Sonomi; Tsuda, Kinsuke; Iritani, Nobuko

    2016-05-01

    Okara, a food by-product from the production of tofu and soy milk, is rich in three beneficial components: insoluble dietary fiber, β-conglycinin, and isoflavones. Although isoflavones and β-conglycinin have recently been shown to improve glucose tolerance, the effects of okara have not yet been elucidated. Therefore, we herein investigated the effects of okara on glucose tolerance in Goto-Kakizaki (GK) rats, a representative animal model of Japanese type 2 diabetes. Male GK rats were fed a 10% lard diet with or without 5% dry okara powder for 2 weeks and an oral glucose tolerance test was performed. Rats were then fed each diet for another week and sacrificed. The expression of genes that are the master regulators of glucose metabolism in adipose tissue was subsequently examined. No significant differences were observed in body weight gain or food intake between the two groups of GK rats. In the oral glucose tolerance test, increases in plasma glucose levels were suppressed by the okara diet. The mRNA expression levels of PPARγ, adiponectin, and GLUT4, which up-regulate the effects of insulin, were increased in epididymal adipose tissue by the okara diet. These results suggest that okara provides a useful means for treating type 2 diabetes. PMID:27257347

  16. Glucose determination with fiber optic spectrometers

    NASA Astrophysics Data System (ADS)

    Starke, Eva; Kemper, Ulf; Barschdorff, Dieter

    1999-05-01

    Noninvasive blood glucose monitoring is the aim of research activities concerning the detection of small glucose concentrations dissolved in water and blood plasma. One approach for these measurements is the exploitation of absorption bands in the near infrared. However, the strong absorption of water represents a major difficulty. Transmission measurements of glucose dissolved in water and in blood plasma in the spectral region around 1600 nm with one- beam spectrometers and a FT-IR spectrometer are discussed. The evaluation of the data is carried out using a two-layer Lambert-Beer model and neural networks. In order to reduce the dimensions of a potential measuring device, an integrated acousto-optic tunable filter (AOTF) with an Erbium doped fiber amplifier as a radiation source is used. The fiber optic components are examined concerning their suitability. The smallest concentrations of glucose dissolved in water that can be separated are approximately 50 mg/dl. In the range of 50 mg/dl to 1000 mg/dl a correlation coefficient of 0.98 between real and estimated glucose concentrations is achieved using neural networks. In blood plasma so far glucose concentrations of about 100 mg/dl can be distinguished with good accuracy.

  17. Statins impair glucose uptake in human cells

    PubMed Central

    Nowis, Dominika; Malenda, Agata; Furs, Karolina; Oleszczak, Bozenna; Sadowski, Radoslaw; Chlebowska, Justyna; Firczuk, Malgorzata; Bujnicki, Janusz M; Staruch, Adam D; Zagozdzon, Radoslaw; Glodkowska-Mrowka, Eliza; Szablewski, Leszek; Golab, Jakub

    2014-01-01

    Objective Considering the increasing number of clinical observations indicating hyperglycemic effects of statins, this study was designed to measure the influence of statins on the uptake of glucose analogs by human cells derived from liver, adipose tissue, and skeletal muscle. Design Flow cytometry and scintillation counting were used to measure the uptake of fluorescently labeled or tritiated glucose analogs by differentiated visceral preadipocytes, skeletal muscle cells, skeletal muscle myoblasts, and contact-inhibited human hepatocellular carcinoma cells. A bioinformatics approach was used to predict the structure of human glucose transporter 1 (GLUT1) and to identify the presence of putative cholesterol-binding (cholesterol recognition/interaction amino acid consensus (CRAC)) motifs within this transporter. Mutagenesis of CRAC motifs in SLC2A1 gene and limited proteolysis of membrane GLUT1 were used to determine the molecular effects of statins. Results Statins significantly inhibit the uptake of glucose analogs in all cell types. Similar effects are induced by methyl-β-cyclodextrin, which removes membrane cholesterol. Statin effects can be rescued by addition of mevalonic acid, or supplementation with exogenous cholesterol. Limited proteolysis of GLUT1 and mutagenesis of CRAC motifs revealed that statins induce conformational changes in GLUTs. Conclusions Statins impair glucose uptake by cells involved in regulation of glucose homeostasis by inducing cholesterol-dependent conformational changes in GLUTs. This molecular mechanism might explain hyperglycemic effects of statins observed in clinical trials. PMID:25452863

  18. 21 CFR 862.1340 - Urinary glucose (nonquantitative) test system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Urinary glucose (nonquantitative) test system. 862... Test Systems § 862.1340 Urinary glucose (nonquantitative) test system. (a) Identification. A urinary glucose (nonquantitative) test system is a device intended to measure glucosuria (glucose in...

  19. 21 CFR 862.1340 - Urinary glucose (nonquantitative) test system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Urinary glucose (nonquantitative) test system. 862... Test Systems § 862.1340 Urinary glucose (nonquantitative) test system. (a) Identification. A urinary glucose (nonquantitative) test system is a device intended to measure glucosuria (glucose in...

  20. 21 CFR 168.121 - Dried glucose sirup.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Dried glucose sirup. 168.121 Section 168.121 Food... HUMAN CONSUMPTION SWEETENERS AND TABLE SIRUPS Requirements for Specific Standardized Sweeteners and Table Sirups § 168.121 Dried glucose sirup. (a) Dried glucose sirup is glucose sirup from which...

  1. 21 CFR 168.121 - Dried glucose sirup.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Dried glucose sirup. 168.121 Section 168.121 Food... HUMAN CONSUMPTION SWEETENERS AND TABLE SIRUPS Requirements for Specific Standardized Sweeteners and Table Sirups § 168.121 Dried glucose sirup. (a) Dried glucose sirup is glucose sirup from which...

  2. 21 CFR 168.121 - Dried glucose sirup.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 2 2012-04-01 2012-04-01 false Dried glucose sirup. 168.121 Section 168.121 Food... HUMAN CONSUMPTION SWEETENERS AND TABLE SIRUPS Requirements for Specific Standardized Sweeteners and Table Sirups § 168.121 Dried glucose sirup. (a) Dried glucose sirup is glucose sirup from which...

  3. Thermogenic Effect of Glucose in Hypothyroid Subjects

    PubMed Central

    Kozacz, Agnieszka; Grunt, Paulina; Steczkowska, Marta; Mikulski, Tomasz; Dąbrowski, Jan; Górecka, Monika; Sanocka, Urszula; Ziemba, Andrzej Wojciech

    2014-01-01

    The importance of thyroid hormone, catecholamines, and insulin in modification of the thermogenic effect of glucose (TEG) was examined in 34 healthy and 32 hypothyroid subjects. We calculated the energy expenditure at rest and during oral glucose tolerance test. Blood samples for determinations of glucose, plasma insulin, adrenaline (A), and noradrenaline (NA) were collected. It was found that TEG was lower in hypothyroid than in control group (19.68 ± 3.90 versus 55.40 ± 7.32 kJ, resp., P < 0.0004). Mean values of glucose and insulin areas under the curve were higher in women with hypothyroidism than in control group (286.79 ± 23.65 versus 188.41 ± 15.84 mmol/L·min, P < 0.003 and 7563.27 ± 863.65 versus 4987.72 ± 583.88 mU/L·min, P < 0.03 resp.). Maximal levels of catecholamines after glucose ingestion were higher in hypothyroid patients than in control subjects (Amax—0.69 ± 0.08 versus 0.30 ± 0.07 nmol/L, P < 0.0001, and NAmax—6.42 ± 0.86 versus 2.54 ± 0.30 nmol/L, P < 0.0002). It can be concluded that in hypothyroidism TEG and glucose tolerance are decreased while the adrenergic response to glucose administration is enhanced. Presumably, these changes are related to decreased insulin sensitivity and responsiveness to catecholamine action. PMID:24711817

  4. Microfabricated glucose biosensor for culture well operation.

    PubMed

    Pemberton, R M; Cox, T; Tuffin, R; Sage, I; Drago, G A; Biddle, N; Griffiths, J; Pittson, R; Johnson, G; Xu, J; Jackson, S K; Kenna, G; Luxton, R; Hart, J P

    2013-04-15

    A water-based carbon screen-printing ink formulation, containing the redox mediator cobalt phthalocyanine (CoPC) and the enzyme glucose oxidase (GOx), was investigated for its suitability to fabricate glucose microbiosensors in a 96-well microplate format: (1) the biosensor ink was dip-coated onto a platinum (Pt) wire electrode, leading to satisfactory amperometric performance; (2) the ink was deposited onto the surface of a series of Pt microelectrodes (10-500 μm diameter) fabricated on a silicon substrate using MEMS (microelectromechanical systems) microfabrication techniques: capillary deposition proved to be successful; a Pt microdisc electrode of ≥100 μm was required for optimum biosensor performance; (3) MEMS processing was used to fabricate suitably sized metal (Pt) tracks and pads onto a silicon 96 well format base chip, and the glucose biosensor ink was screen-printed onto these pads to create glucose microbiosensors. When formed into microwells, using a 340 μl volume of buffer, the microbiosensors produced steady-state amperometric responses which showed linearity up to 5 mM glucose (CV=6% for n=5 biosensors). When coated, using an optimised protocol, with collagen in order to aid cell adhesion, the biosensors continued to show satisfactory performance in culture medium (linear range to 2 mM, dynamic range to 7 mM, CV=5.7% for n=4 biosensors). Finally, the operation of these collagen-coated microbiosensors, in 5-well 96-well format microwells, was tested using a 5-channel multipotentiostat. A relationship between amperometric response due to glucose, and cell number in the microwells, was observed. These results indicate that microphotolithography and screen-printing techniques can be combined successfully to produce microbiosensors capable of monitoring glucose metabolism in 96 well format cell cultures. The potential application areas for these microbiosensors are discussed. PMID:23265827

  5. Glucose kinases from Streptomyces peucetius var. caesius.

    PubMed

    Ruiz-Villafán, Beatriz; Rodríguez-Sanoja, Romina; Aguilar-Osorio, Guillermo; Gosset, Guillermo; Sanchez, Sergio

    2014-07-01

    Glucose kinases (Glks) are enzymes of the glycolytic pathway involved in glucose phosphorylation. These enzymes can use various phosphoryl donors such as ATP, ADP, and polyphosphate. In several streptomycetes, ATP-glucose kinase (ATP-Glk) has been widely studied and regarded as the main glucose phosphorylating enzyme and is likely a regulatory protein in carbon catabolite repression. In cell extracts from the doxorubicin overproducing strain Streptomyces peucetius var. caesius, grown in glucose, a polyphosphate-dependent Glk (Pp-Glk) was detected by zymogram. Maximum activity was observed during the stationary growth phase (48 h) of cells grown in 100 mM glucose. No activity was detected when 20 mM glutamate was used as the only carbon source, supporting a role for glucose in inducing this enzyme. Contrary to wild-type strains of Streptomyces coelicolor, Streptomyces lividans, and Streptomyces thermocarboxydus K-155, S. peucetius var. caesius produced 1.8 times more Pp-Glk than ATP-Glk. In addition, this microorganism produced five and four times more Pp-Glk and anthracyclines, respectively, than its wild-type S. peucetius parent strain, supporting a role for this enzyme in antibiotic production in the overproducer strain. A cloned 726-bp DNA fragment from S. peucetius var. caesius encoded a putative Pp-Glk, with amino acid identities between 83 and 87 % to orthologous sequences from the above-cited streptomycetes. The cloned fragment showed the polyphosphate-binding sequences GXDIGGXXIK, TXGTGIGSA, and KEX(4)SWXXWA. Sequences for the Zn-binding motif were not detected in this fragment, suggesting that Pp-Glk is not related to the Glk ROK family of proteins. PMID:24687748

  6. 21 CFR 168.121 - Dried glucose sirup.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Dried glucose sirup. 168.121 Section 168.121 Food... Table Sirups § 168.121 Dried glucose sirup. (a) Dried glucose sirup is glucose sirup from which the... equivalent), expressed as D-glucose, is not less than 88.0 percent m/m, calculated on a dry basis; or (2)...

  7. 21 CFR 168.121 - Dried glucose sirup.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Dried glucose sirup. 168.121 Section 168.121 Food... Table Sirups § 168.121 Dried glucose sirup. (a) Dried glucose sirup is glucose sirup from which the... equivalent), expressed as D-glucose, is not less than 88.0 percent m/m, calculated on a dry basis; or (2)...

  8. 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.

  9. A MEMS affinity glucose sensor using a biocompatible glucose-responsive polymer

    PubMed Central

    Huang, Xian; Li, Siqi; Schultz, Jerome S.; Wang, Qian; Lin, Qiao

    2013-01-01

    We present a MEMS affinity sensor that can potentially allow long-term continuous monitoring of glucose in subcutaneous tissue for diabetes management. The sensing principle is based on detection of viscosity changes due to affinity binding between glucose and poly(acrylamide-ran-3-acrylamidophenylboronic acid) (PAA-ran-PAAPBA), a biocompatible, glucose-specific polymer. The device uses a magnetically driven vibrating microcantilever as a sensing element, which is fabricated from Parylene and situated in a microchamber. A solution of PAA-ran-PAAPBA fills the microchamber, which is separated from the surroundings by a semi-permeable membrane. Glucose permeates through the membrane and binds reversibly to the phenylboronic acid moiety of the polymer. This results in a viscosity change of the sensing solution, which is obtained by measuring the damped cantilever vibration using an optical lever setup, allowing determination of the glucose concentration. Experimental results demonstrate that the device is capable of detecting glucose at physiologically relevant concentrations from 27 mg/dL to 324 mg/dL. The glucose response time constant of the sensor is approximately 3 min, which can be further improved with device design optimization. Excellent reversibility and stability are observed in sensor responses, as highly desired for long-term, stable continuous glucose monitoring. PMID:24511207

  10. Non-invasive measurement of glucose uptake of skeletal muscle tissue models using a glucose nanobiosensor.

    PubMed

    Obregón, Raquel; Ahadian, Samad; Ramón-Azcón, Javier; Chen, Luyang; Fujita, Takeshi; Shiku, Hitoshi; Chen, Mingwei; Matsue, Tomokazu

    2013-12-15

    Skeletal muscle tissues play a significant role to maintain the glucose level of whole body and any dysfunction of this tissue leads to the diabetes disease. A culture medium was created in which the muscle cells could survive for a long time and meanwhile it did not interfere with the glucose sensing. We fabricated a model of skeletal muscle tissues in vitro to monitor its glucose uptake. A nanoporous gold as a high sensitive nanobiosensor was then successfully developed and employed to detect the glucose uptake of the tissue models in this medium upon applying the electrical stimulation in a rapid, and non-invasive approach. The response of the glucose sensor was linear in a wide concentration range of 1-50 mM, with a detection limit of 3 μM at a signal-to-noise ratio of 3.0. The skeletal muscle tissue was electrically stimulated during 24 h and glucose uptake was monitored during this period. During the first 3 h of stimulation, electrically stimulated muscle tissue consumed almost twice the amount of glucose than counterpart non-stimulated sample. In total, the glucose consumption of muscle tissues was higher for the electrically stimulated tissues compared to those without applying the electrical field. PMID:23856563

  11. Biosensor based on glucose oxidase-nanoporous gold co-catalysis for glucose detection.

    PubMed

    Wu, Chao; Sun, Huihui; Li, Yufei; Liu, Xueying; Du, Xiaoyu; Wang, Xia; Xu, Ping

    2015-04-15

    Promoting the electrocatalytic oxidation of glucose is crucial in glucose biosensor design. In this study, nanoporous gold (NPG) was selected for glucose oxidase (GOx) immobilization and glucose biosensor fabrication because of its open, highly conductive, biocompatible, and interconnected porous structure, which also facilitates the electrocatalytic oxidation of glucose. The electrochemical reaction on the surface of the resulting GOx/NPG/GCE bioelectrode was attributed to the co-catalysis effect of GOx and NPG. A surface-confined reaction in a phosphate buffer solution was observed at the bioelectrode during cyclic voltammetry experiments. Linear responses were observed for large glucose concentrations ranging from 50μM to 10mM, with a high sensitivity of 12.1μAmM(-1)cm(-2) and a low detection limit of 1.02μM. Furthermore, the GOx/NPG/GCE bioelectrode presented strong anti-interference capability against cholesterol, urea, tributyrin, ascorbic acid, and uric acid, along with a long shelf-life. For the detection of glucose in human serum, the data generated by the GOx/NPG/GCE bioelectrode were in good agreement with those produced by an automatic biochemical analyzer. These unique properties make the GOx/NPG/GCE bioelectrode an excellent choice for the construction of a glucose biosensor. PMID:25463642

  12. A MEMS affinity glucose sensor using a biocompatible glucose-responsive polymer.

    PubMed

    Huang, Xian; Li, Siqi; Schultz, Jerome S; Wang, Qian; Lin, Qiao

    2009-07-16

    We present a MEMS affinity sensor that can potentially allow long-term continuous monitoring of glucose in subcutaneous tissue for diabetes management. The sensing principle is based on detection of viscosity changes due to affinity binding between glucose and poly(acrylamide-ran-3-acrylamidophenylboronic acid) (PAA-ran-PAAPBA), a biocompatible, glucose-specific polymer. The device uses a magnetically driven vibrating microcantilever as a sensing element, which is fabricated from Parylene and situated in a microchamber. A solution of PAA-ran-PAAPBA fills the microchamber, which is separated from the surroundings by a semi-permeable membrane. Glucose permeates through the membrane and binds reversibly to the phenylboronic acid moiety of the polymer. This results in a viscosity change of the sensing solution, which is obtained by measuring the damped cantilever vibration using an optical lever setup, allowing determination of the glucose concentration. Experimental results demonstrate that the device is capable of detecting glucose at physiologically relevant concentrations from 27 mg/dL to 324 mg/dL. The glucose response time constant of the sensor is approximately 3 min, which can be further improved with device design optimization. Excellent reversibility and stability are observed in sensor responses, as highly desired for long-term, stable continuous glucose monitoring. PMID:24511207

  13. 1-deoxynojirimycin inhibits glucose absorption and accelerates glucose metabolism in streptozotocin-induced diabetic mice

    PubMed Central

    Li, You-Gui; Ji, Dong-Feng; Zhong, Shi; Lin, Tian-Bao; Lv, Zhi-Qiang; Hu, Gui-Yan; Wang, Xin

    2013-01-01

    We investigated the role of 1-deoxynojirimycin (DNJ) on glucose absorption and metabolism in normal and diabetic mice. Oral and intravenous glucose tolerance tests and labeled 13C6-glucose uptake assays suggested that DNJ inhibited intestinal glucose absorption in intestine. We also showed that DNJ down-regulated intestinal SGLT1, Na+/K+-ATP and GLUT2 mRNA and protein expression. Pretreatment with DNJ (50 mg/kg) increased the activity, mRNA and protein levels of hepatic glycolysis enzymes (GK, PFK, PK, PDE1) and decreased the expression of gluconeogenesis enzymes (PEPCK, G-6-Pase). Assays of protein expression in hepatic cells and in vitro tests with purified enzymes indicated that the increased activity of glucose glycolysis enzymes was resulted from the relative increase in protein expression, rather than from direct enzyme activation. These results suggest that DNJ inhibits intestinal glucose absorption and accelerates hepatic glucose metabolism by directly regulating the expression of proteins involved in glucose transport systems, glycolysis and gluconeogenesis enzymes. PMID:23536174

  14. Effects of iriflophenone 3-C-β-glucoside on fasting blood glucose level and glucose uptake

    PubMed Central

    Pranakhon, Ratree; Aromdee, Chantana; Pannangpetch, Patchareewan

    2015-01-01

    Background: One of the biological activities of agar wood (Aquilaria sinensis Lour., Thymelaeaceae), is anti-hyperglycemic activity. The methanolic extract (ME) was proven to possess the fasting blood glucose activity in rat and glucose uptake transportation by rat adipocytes. Objective: To determine the decreasing fasting blood glucose level of constituents affordable for in vivo test. If the test was positive, the mechanism which is positive to the ME, glucose transportation, will be performed. Materials and Methods: The ME was separated by column chromatography and identified by spectroscopic methods. Mice was used as an animal model (in vivo), and rat adipocytes were used for the glucose transportation activity (in vitro). Result: Iriflophenone 3-C-β-glucoside (IPG) was the main constituent, 3.17%, and tested for the activities. Insulin and the ME were used as positive controls. The ME, IPG and insulin lowered blood glucose levels by 40.3, 46.4 and 41.5%, respectively, and enhanced glucose uptake by 152, 153, and 183%, respectively. Conclusion: These findings suggest that IPG is active in lowering fasting blood glucose with potency comparable to that of insulin. PMID:25709215

  15. Glucose sensing by time-resolved fluorescence of sol-gel immobilized glucose oxidase.

    PubMed

    Esposito, Rosario; Della Ventura, Bartolomeo; De Nicola, Sergio; Altucci, Carlo; Velotta, Raffaele; Mita, Damiano Gustavo; Lepore, Maria

    2011-01-01

    A monolithic silica gel matrix with entrapped glucose oxidase (GOD) was constructed as a bioactive element in an optical biosensor for glucose determination. Intrinsic fluorescence of free and immobilised GOD was investigated in the visible range in presence of different glucose concentrations by time-resolved spectroscopy with time-correlated single-photon counting detector. A three-exponential model was used for analysing the fluorescence transients. Fractional intensities and mean lifetime were shown to be sensitive to the enzymatic reaction and were used for obtaining calibration curve for glucose concentration determination. The sensing system proposed achieved high resolution (up to 0.17 mM) glucose determination with a detection range from 0.4 mM to 5 mM. PMID:22163807

  16. Glucose-lowering effects of intestinal bile acid sequestration through enhancement of splanchnic glucose utilization.

    PubMed

    Prawitt, Janne; Caron, Sandrine; Staels, Bart

    2014-05-01

    Intestinal bile acid (BA) sequestration efficiently lowers plasma glucose concentrations in type 2 diabetes (T2D) patients. Because BAs act as signaling molecules via receptors, including the G protein-coupled receptor TGR5 and the nuclear receptor FXR (farnesoid X receptor), to regulate glucose homeostasis, BA sequestration, which interrupts the entero-hepatic circulation of BAs, constitutes a plausible action mechanism of BA sequestrants. An increase of intestinal L-cell glucagon-like peptide-1 (GLP-1) secretion upon TGR5 activation is the most commonly proposed mechanism, but recent studies also argue for a direct entero-hepatic action to enhance glucose utilization. We discuss here recent findings on the mechanisms of sequestrant-mediated glucose lowering via an increase of splanchnic glucose utilization through entero-hepatic FXR signaling. PMID:24731596

  17. Attenuation of Diabetic Conditions by Sida rhombifolia in Moderately Diabetic Rats and Inability to Produce Similar Effects in Severely Diabetic in Rats

    PubMed Central

    Chaturvedi, Padmaja; Kwape, Tebogo Elvis

    2015-01-01

    Objectives: This study was done out to evaluate the effects of Sida rhombifolia methanol extract (SRM) on diabetes in moderately diabetic (MD) and severely diabetic (SD) Sprague-Dawley rats. Methods: SRM was prepared by soaking the powdered plant material in 70% methanol and rota evaporating the methanol from the extract. Effective hypoglycemic doses were established by performing oral glucose tolerance tests (OGTTs) in normal rats. Hourly effects of SRM on glucose were observed in the MD and the SD rats. Rats were grouped, five rats to a group, into normal control 1 (NC1), MD control 1 (MDC1), MD experimental 1 (MDE1), SD control 1 (SDC1), and SD experimental 1 (SDE1) groups. All rats in the control groups were administered 1 mL of distilled water (DW). The rats in the MDE1 and the SDE1 groups were administered SRM orally at 200 and 300 mg/kg body weight (BW), respectively, dissolved in 1 mL of DW. Blood was collected initially and at intervals of 1 hour for 6 hours to measure blood glucose. A similar experimental design was followed for the 30-day long-term trial. Finally, rats were sacrificed, and blood was collected to measure blood glucose, lipid profiles, thiobarbituric acid reactive substances (TBARS) and reduced glutathione (GSH). Results: OGTTs indicated that two doses (200 and 300 mg/kg BW) were effective hypoglycemic doses in normal rats. Both doses reduced glucose levels after 1 hour in the MDE1 and the SDE1 groups. A long-term trial of SRM in the MD group showed a reduced glucose level, a normal lipid profile, and normal GSH and TBARS levels. In SD rats, SRM had no statistically significant effects on these parameters. Normal weight was achieved in the MD rats, but the SD rats showed reduced BW. Conclusion: The study demonstrates that SRM has potential to alleviate the conditions of moderate diabetic, but not severe diabetes. PMID:26998385

  18. Multispectral polarimetric system for glucose monitoring

    NASA Astrophysics Data System (ADS)

    Cote, Gerard L.; Gorde, Harshal; Janda, Joseph; Cameron, Brent D.

    1998-05-01

    In this preliminary investigation, a two wavelength optical polarimetric system was used to show the potential of the approach to be used as an in vivo noninvasive glucose monitor. The dual wavelength method is shown as a means of overcoming two of them ore important problems with this approach for glucose monitoring, namely, motion artifact and the presence of other optically chiral components. The use of polarized light is based on the fact that the polarization vector of the light rotates when it interacts with an optically active material such as glucose. The amount of rotation of the light polarization is directly proportional to the optically active molecular concentration and to the sample path length. The end application of this system would be to estimate blood glucose concentrations indirectly by measuring the amount of rotation of the light beam's polarization state due to glucose variations within the aqueous humor of the anterior chamber of the eye. The system was evaluated in vitro in the presence of motion artifact and in combination with albumin, another interfering optical rotatory chemical component. It was shown that the dual wavelength approach has potential for overcoming these problems.

  19. OXIDATIVE ASSIMILATION OF GLUCOSE BY PSEUDOMONAS AERUGINOSA

    PubMed Central

    Duncan, Margaret G.; Campbell, J. J. R.

    1962-01-01

    Duncan, Margaret G. (The University of British Columbia, Vancouver, British Columbia, Canada) and J. J. R. Campbell. Oxidative assimilation of glucose by Pseudomonas aeruginosa. J. Bacteriol. 84:784–792. 1962—Oxidative assimilation of glucose by washed-cell suspensions of Pseudomonas aeruginosa was studied using C14-labeled substrate. At the time of glucose disappearance, only small amounts of radioactivity were present in the cells, and α-ketoglutaric acid accumulated in the supernatant fluid. Most of the material synthesized by the cells during oxidative assimilation was nitrogenous, the ammonia being supplied by the endogenous respiration. The cold trichloroacetic acid-soluble fraction and the lipid fraction appeared to be important during the early stages of oxidative assimilation, and the largest percentage of the incorporated radioactivity was found in the protein fraction. In the presence of added ammonia, assimilation was greatly increased and no α-ketoglutaric acid was found in the supernatant fluid. Sodium azide partially inhibited incorporation into all major cell fractions, and at higher concentrations depressed the rate of glucose oxidation. During oxidative assimilation, chloramphenicol specifically inhibited the synthesis of protein. Oxidative assimilation of glucose by this organism did not appear to involve the synthesis of a primary product such as is found in the majority of bacteria. PMID:16561965

  20. Glucose Oxidation Modulates Anoikis and Tumor Metastasis

    PubMed Central

    Kamarajugadda, Sushama; Stemboroski, Lauren; Cai, Qingsong; Simpson, Nicholas E.; Nayak, Sushrusha; Tan, Ming

    2012-01-01

    Cancer cells exhibit altered glucose metabolism characterized by a preference for aerobic glycolysis or the Warburg effect, and the cells resist matrix detachment-induced apoptosis, which is called anoikis, a barrier to metastasis. It remains largely unclear whether tumor metabolism influences anoikis and metastasis. Here we show that when detached from the matrix, untransformed mammary epithelial cells undergo metabolic reprogramming by markedly upregulating pyruvate dehydrogenase (PDH) kinase 4 (PDK4) through estrogen-related receptor gamma (ERRγ), thereby inhibiting PDH and attenuating the flux of glycolytic carbon into mitochondrial oxidation. To decipher the significance of this metabolic response, we found that depletion of PDK4 or activation of PDH increased mitochondrial respiration and oxidative stress in suspended cells, resulting in heightened anoikis. Conversely, overexpression of PDKs prolonged survival of cells in suspension. Therefore, decreased glucose oxidation following cell detachment confers anoikis resistance. Unlike untransformed cells, most cancer cells demonstrate reduced glucose oxidation even under attached conditions, and thus they inherently possess a survival advantage when suspended. Normalization of glucose metabolism by stimulating PDH in cancer cells restores their susceptibility to anoikis and impairs their metastatic potential. These results suggest that the Warburg effect, more specifically, diminished glucose oxidation, promotes anoikis resistance and metastasis and that PDKs are potential targets for antimetastasis therapy. PMID:22431524

  1. MicroRNA 33 Regulates Glucose Metabolism

    PubMed Central

    Ramírez, Cristina M.; Goedeke, Leigh; Rotllan, Noemi; Yoon, Je-Hyun; Cirera-Salinas, Daniel; Mattison, Julie A.; Suárez, Yajaira; de Cabo, Rafael; Gorospe, Myriam

    2013-01-01

    Metabolic diseases are characterized by the failure of regulatory genes or proteins to effectively orchestrate specific pathways involved in the control of many biological processes. In addition to the classical regulators, recent discoveries have shown the remarkable role of small noncoding RNAs (microRNAs [miRNAs]) in the posttranscriptional regulation of gene expression. In this regard, we have recently demonstrated that miR-33a and miR33b, intronic miRNAs located within the sterol regulatory element-binding protein (SREBP) genes, regulate lipid metabolism in concert with their host genes. Here, we show that miR-33b also cooperates with SREBP1 in regulating glucose metabolism by targeting phosphoenolpyruvate carboxykinase (PCK1) and glucose-6-phosphatase (G6PC), key regulatory enzymes of hepatic gluconeogenesis. Overexpression of miR-33b in human hepatic cells inhibits PCK1 and G6PC expression, leading to a significant reduction of glucose production. Importantly, hepatic SREBP1c/miR-33b levels correlate inversely with the expression of PCK1 and G6PC upon glucose infusion in rhesus monkeys. Taken together, these results suggest that miR-33b works in concert with its host gene to ensure a fine-tuned regulation of lipid and glucose homeostasis, highlighting the clinical potential of miR-33a/b as novel therapeutic targets for a range of metabolic diseases. PMID:23716591

  2. FOXN3 Regulates Hepatic Glucose Utilization.

    PubMed

    Karanth, Santhosh; Zinkhan, Erin K; Hill, Jonathon T; Yost, H Joseph; Schlegel, Amnon

    2016-06-21

    A SNP (rs8004664) in the first intron of the FOXN3 gene is associated with human fasting blood glucose. We find that carriers of the risk allele have higher hepatic expression of the transcriptional repressor FOXN3. Rat Foxn3 protein and zebrafish foxn3 transcripts are downregulated during fasting, a process recapitulated in human HepG2 hepatoma cells. Transgenic overexpression of zebrafish foxn3 or human FOXN3 increases zebrafish hepatic gluconeogenic gene expression, whole-larval free glucose, and adult fasting blood glucose and also decreases expression of glycolytic genes. Hepatic FOXN3 overexpression suppresses expression of mycb, whose ortholog MYC is known to directly stimulate expression of glucose-utilization enzymes. Carriers of the rs8004664 risk allele have decreased MYC transcript abundance. Human FOXN3 binds DNA sequences in the human MYC and zebrafish mycb loci. We conclude that the rs8004664 risk allele drives excessive expression of FOXN3 during fasting and that FOXN3 regulates fasting blood glucose. PMID:27292639

  3. Nanomaterial-mediated Biosensors for Monitoring Glucose

    PubMed Central

    Taguchi, Masashige; Ptitsyn, Andre; McLamore, Eric S.

    2014-01-01

    Real-time monitoring of physiological glucose transport is crucial for gaining new understanding of diabetes. Many techniques and equipment currently exist for measuring glucose, but these techniques are limited by complexity of the measurement, requirement of bulky equipment, and low temporal/spatial resolution. The development of various types of biosensors (eg, electrochemical, optical sensors) for laboratory and/or clinical applications will provide new insights into the cause(s) and possible treatments of diabetes. State-of-the-art biosensors are improved by incorporating catalytic nanomaterials such as carbon nanotubes, graphene, electrospun nanofibers, and quantum dots. These nanomaterials greatly enhance biosensor performance, namely sensitivity, response time, and limit of detection. A wide range of new biosensors that incorporate nanomaterials such as lab-on-chip and nanosensor devices are currently being developed for in vivo and in vitro glucose sensing. These real-time monitoring tools represent a powerful diagnostic and monitoring tool for measuring glucose in diabetes research and point of care diagnostics. However, concerns over the possible toxicity of some nanomaterials limit the application of these devices for in vivo sensing. This review provides a general overview of the state of the art in nanomaterial-mediated biosensors for in vivo and in vitro glucose sensing, and discusses some of the challenges associated with nanomaterial toxicity. PMID:24876594

  4. FOXN3 regulates hepatic glucose utilization

    PubMed Central

    Karanth, Santhosh; Zinkhan, Erin K.; Hill, Jonathon T.; Yost, H. Joseph; Schlegel, Amnon

    2016-01-01

    SUMMARY A SNP (rs8004664) in the first intron of the FOXN3 gene is associated with human fasting blood glucose. We find that carriers of the risk allele have higher hepatic expression of the transcriptional repressor FOXN3. Rat Foxn3 protein and zebrafish foxn3 transcripts are downregulated during fasting, a process recapitulated in human HepG2 hepatoma cells. Transgenic overexpression of zebrafish foxn3 or human FOXN3 increases zebrafish hepatic gluconeogenic gene expression, whole-larval free glucose, and adult fasting blood glucose, and also decreases expression of glycolytic genes. Hepatic FOXN3 overexpression suppresses expression of mycb, whose ortholog MYC is known to directly stimulate expression of glucose-utilization enzymes. Carriers of the rs8004664 risk allele have decreased MYC transcript abundance. Human FOXN3 binds DNA sequences in the human FOXN3 and zebrafish mycb loci. We conclude that the rs8004664 risk allele drives excessive expression of FOXN3 during fasting and that FOXN3 regulates fasting blood glucose. PMID:27292639

  5. Facilitated diffusion of 6-deoxy-D-glucose in bakers' yeast: evidence against phosphorylation-associated transport of glucose.

    PubMed Central

    Romano, A H

    1982-01-01

    6-Deoxy-D-glucose, a structural homomorph of D-glucose which lacks a hydroxyl group at carbon 6 and thus cannot be phosphorylated, is transported by Saccharomyces cerevisiae via a facilitated diffusion system with affinity equivalent to that shown with D-glucose. This finding supports the facilitated diffusion mechanism for glucose transport and contradicts theories of transport-associated phosphorylation which hold that sugar phosphorylation is necessary for high-affinity operation of the glucose carrier. PMID:6754704

  6. The glucose metabolite methylglyoxal inhibits expression of the glucose transporter genes by inactivating the cell surface glucose sensors Rgt2 and Snf3 in yeast

    PubMed Central

    Roy, Adhiraj; Hashmi, Salman; Li, Zerui; Dement, Angela D.; Hong Cho, Kyu; Kim, Jeong-Ho

    2016-01-01

    Methylglyoxal (MG) is a cytotoxic by-product of glycolysis. MG has inhibitory effect on the growth of cells ranging from microorganisms to higher eukaryotes, but its molecular targets are largely unknown. The yeast cell-surface glucose sensors Rgt2 and Snf3 function as glucose receptors that sense extracellular glucose and generate a signal for induction of expression of genes encoding glucose transporters (HXTs). Here we provide evidence that these glucose sensors are primary targets of MG in yeast. MG inhibits the growth of glucose-fermenting yeast cells by inducing endocytosis and degradation of the glucose sensors. However, the glucose sensors with mutations at their putative ubiquitin-acceptor lysine residues are resistant to MG-induced degradation. These results suggest that the glucose sensors are inactivated through ubiquitin-mediated endocytosis and degraded in the presence of MG. In addition, the inhibitory effect of MG on the glucose sensors is greatly enhanced in cells lacking Glo1, a key component of the MG detoxification system. Thus the stability of these glucose sensors seems to be critically regulated by intracellular MG levels. Taken together, these findings suggest that MG attenuates glycolysis by promoting degradation of the cell-surface glucose sensors and thus identify MG as a potential glycolytic inhibitor. PMID:26764094

  7. Stable and flexible system for glucose homeostasis

    NASA Astrophysics Data System (ADS)

    Hong, Hyunsuk; Jo, Junghyo; Sin, Sang-Jin

    2013-09-01

    Pancreatic islets, controlling glucose homeostasis, consist of α, β, and δ cells. It has been observed that α and β cells generate out-of-phase synchronization in the release of glucagon and insulin, counter-regulatory hormones for increasing and decreasing glucose levels, while β and δ cells produce in-phase synchronization in the release of the insulin and somatostatin. Pieces of interactions between the islet cells have been observed for a long time, although their physiological role as a whole has not been explored yet. We model the synchronized hormone pulses of islets with coupled phase oscillators that incorporate the observed cellular interactions. The integrated model shows that the interaction from β to δ cells, of which sign is a subject of controversy, should be positive to reproduce the in-phase synchronization between β and δ cells. The model also suggests that δ cells help the islet system flexibly respond to changes of glucose environment.

  8. [Regulation of bone homeostasis by glucose].

    PubMed

    Fukasawa, Kazuya; Hinoi, Eiichi

    2016-08-01

    Synthesis of type Ⅰ collagen, a major component of the bone matrix, precedes the expression of Runt-related transcription factor 2(Runx2), a master regulator in osteoblast differentiation. Thus, a direct link between osteoblast differentiation and bone formation is seemingly absent, and how these are maintained in a coordinated matter remains unclear. It was recently demonstrated that osteoblasts depend on glucose, which glucose transporter type 1(GLUT1)takes up as an energy source, and it was found that glucose uptake promotes osteoblast differentiation and bone formation via AMP-activated protein kinase. It was also shown that Runx2 upregulates GLUT1 expression, and this Runx2-GLUT1 feedforward regulation integrates and coordinates osteoblast differentiation and bone formation throughout life. These previous findings revealed that the energy metabolism balance in osteoblasts integrates the differentiation and function of osteoblasts, and re-emphasized the importance of crosstalk between bone and sugar metabolism. PMID:27461500

  9. Roles of Glucose in Photoreceptor Survival*

    PubMed Central

    Chertov, Andrei O.; Holzhausen, Lars; Kuok, Iok Teng; Couron, Drew; Parker, Ed; Linton, Jonathan D.; Sadilek, Martin; Sweet, Ian R.; Hurley, James B.

    2011-01-01

    Vertebrate photoreceptor neurons have a high demand for metabolic energy, and their viability is very sensitive to genetic and environmental perturbations. We investigated the relationship between energy metabolism and cell death by evaluating the metabolic effects of glucose deprivation on mouse photoreceptors. Oxygen consumption, lactate production, ATP, NADH/NAD+, TCA cycle intermediates, morphological changes, autophagy, and viability were evaluated. We compared retinas incubated with glucose to retinas deprived of glucose or retinas treated with a mixture of mitochondrion-specific fuels. Rapid and slow phases of cell death were identified. The rapid phase is linked to reduced mitochondrial activity, and the slower phase reflects a need for substrates for cell maintenance and repair. PMID:21840997

  10. Sleep Control, GPCRs, and Glucose Metabolism.

    PubMed

    Tsuneki, Hiroshi; Sasaoka, Toshiyasu; Sakurai, Takeshi

    2016-09-01

    Modern lifestyles prolong daily activities into the nighttime, disrupting circadian rhythms, which may cause sleep disturbances. Sleep disturbances have been implicated in the dysregulation of blood glucose levels and reported to increase the risk of type 2 diabetes (T2D) and diabetic complications. Sleep disorders are treated using anti-insomnia drugs that target ionotropic and G protein-coupled receptors (GPCRs), including γ-aminobutyric acid (GABA) agonists, melatonin agonists, and orexin receptor antagonists. A deeper understanding of the effects of these medications on glucose metabolism and their underlying mechanisms of action is crucial for the treatment of diabetic patients with sleep disorders. In this review we focus on the beneficial impact of sleep on glucose metabolism and suggest a possible strategy for therapeutic intervention against sleep-related metabolic disorders. PMID:27461005

  11. Dynamics of water molecules in glucose solutions.

    SciTech Connect

    Talon, C.; Smith, L. J.; Brady, J. W.; Copley, J. R. D.; Price, D. L.; Saboungi, M. L.; Materials Science Division; Centre de Recherche sur la Matiyre Divisye; Cornell Univ.; NIST; Centre de Recherche sur les Matyriaux y Haute Tempyrature

    2004-04-22

    The effects of the solution of glucose molecules on the dynamics of solvent water have been studied by quasielastic neutron scattering (QENS) measurements on solutions of selectively deuterated glucose in natural water. The data are fitted to two Lorentzians ascribed to pure translational and mixed translational and rotational character, respectively. The addition of the glucose to the water causes a substantial slowing down, by a factor 10 for the translational diffusion and 3-4 for the rotational motion at the highest concentration studied, 1:11 C{sub 6}H{sub 12}O{sub 6}:H{sub 2}O. The values obtained for water diffusion constants are consistent with previous QENS and NMR experiments on monosaccharide solutions but an order of magnitude higher than those derived from a recent molecular dynamics simulation.

  12. Glucose Biosensors: An Overview of Use in Clinical Practice

    PubMed Central

    Yoo, Eun-Hyung; Lee, Soo-Youn

    2010-01-01

    Blood glucose monitoring has been established as a valuable tool in the management of diabetes. Since maintaining normal blood glucose levels is recommended, a series of suitable glucose biosensors have been developed. During the last 50 years, glucose biosensor technology including point-of-care devices, continuous glucose monitoring systems and noninvasive glucose monitoring systems has been significantly improved. However, there continues to be several challenges related to the achievement of accurate and reliable glucose monitoring. Further technical improvements in glucose biosensors, standardization of the analytical goals for their performance, and continuously assessing and training lay users are required. This article reviews the brief history, basic principles, analytical performance, and the present status of glucose biosensors in the clinical practice. PMID:22399892

  13. Electropolymerized Conducting Polymers as Glucose Sensors

    NASA Astrophysics Data System (ADS)

    Sadik, Omowunmi A.; Brenda, Sharin; Joasil, Patrick; Lord, John

    1999-07-01

    Conducting polymers are of considerable interest. Their electrochemical synthesis requires only inexpensive starting materials and low-cost equipment. This paper presents a laboratory-based experiment for possible inclusion in the undergraduate instrumental analysis laboratory curriculum. The objectives are to perform cyclic voltammetry on electropolymerized conducting polymers, to observe the effects of various parameters on the voltammogram obtained, and to perform quantitative analysis of glucose. In a typical experiment, glucose oxidase enzyme (GOx) was immobilized at an electrode surface by the electropolymerization of pyrrole from an aqueous solution containing the enzyme. The chemical activity of the immobilized GOx was evaluated by indirectly monitoring glucose oxidation using the electropolymerized PPy-modified electrode. The amount of glucose present was then determined by observing the rate at which hydrogen peroxide was produced. The magnitude of the current was linearly proportional to the concentration of glucose over the range 1 x 10-3 to 5 x 10-5M. The limit of detection was estimated at 3 times the background noise, 8 x 10-5 M glucose. The Michaelis-Menten parameters, Km and Vmax, were calculated to be approximately 1.5 x 10-3 M and 10-9 m/s, respectively, comparable with values cited in literature. This experiment illustrates the fundamental electrochemical and biosensor concepts. It reinforces the underlying principles of dynamic electrochemistry and illustrates the potential of using conducting polymers for analytical applications. The simple low-cost procedure employed should be attractive for undergraduate research projects, particularly in departments with modest means.

  14. Familial renal glycosuria and modifications of glucose renal excretion.

    PubMed

    Prié, D

    2014-12-01

    Under physiological conditions, the kidneys contribute to glucose homoeostasis by producing glucose by gluconeogenesis and preventing glucose loss in urine. The glucose filtered by the glomeruli is completely reabsorbed in the renal proximal tubule. Renal gluconeogenesis produces 25% of the circulating glucose in the postabsorptive state, while the amount of glucose reabsorbed by the kidneys largely exceeds the quantity synthesized by kidney gluconeogenesis. Sodium-glucose cotransporter type 2 (SGLT-2) and glucose transporter 2 (GLUT2) carry out more than 90% of renal glucose uptake. In diabetes, both gluconeogenesis and renal glucose reabsorption are increased. The augmentation of glucose uptake in diabetes is due to the overexpression of renal glucose transporters SGLT-2 and GLUT2 in response to the increase in expression of transcription activator hepatic nuclear factor 1-alpha (HNF1α). The rise in glucose uptake contributes to hyperglycaemia and induces glomerular hyperfiltration by increasing sodium and water reabsorption in the proximal tubule that, in turn, modifies urine flux at the macula densa. SGLT-2 inhibitors improve glycaemic control and prevent renal hyperfiltration in diabetes. Loss of SGLT-2 transporter function is a benign state characterized by glycosuria. In contrast, mutations of other glucose transporters expressed in the kidney are responsible for severe disorders. PMID:25554066

  15. Nonenzymatic glucose detection using mesoporous platinum.

    PubMed

    Park, Sejin; Chung, Taek Dong; Kim, Hee Chan

    2003-07-01

    Roughness of nanoscopic dimensions can be used to selectively enhance the faradaic current of a sluggish reaction. Using this principle, we constructed mesoporous structures on the surfaces of pure platinum electrodes responding even more sensitively to glucose than to common interfering species, such as L-ascorbic acid and 4-acetamidophenol. Good sensitivities, as high as 9.6 microA cm(-2) mM(-1), were reproducibly observed in the presence of high concentration of chloride ion. The selectivities, sensitivities, and stabilities determined experimentally have demonstrated the potential of mesoporous platinum as a novel candidate for nonenzymatic glucose sensors. PMID:12964749

  16. Glucose transporter expression in rat mammary gland.

    PubMed Central

    Burnol, A F; Leturque, A; Loizeau, M; Postic, C; Girard, J

    1990-01-01

    The expression of different glucose transporter isoforms was measured during the development and differentiation of the rat mammary gland. Before conception, when the mammary gland is mainly composed of adipocytes, Glut 4 and Glut 1 mRNAs and proteins were present. During pregnancy, the expression of Glut 4 decreased progressively, whereas that of Glut 1 increased. In the lactating mammary gland only Glut 1 was present, and was expressed at a high level. The absence of Glut 4 suggests that glucose transport is not regulated by insulin in the lactating rat mammary gland. Images Fig. 1. Fig. 2. PMID:2396989

  17. Limitations of Continuous Glucose Monitor Usage.

    PubMed

    Anhalt, Henry

    2016-03-01

    Much progress has been made in diabetes treatments since the first dose of insulin was administered in 1921. However, a truly transformational moment in diabetes care occurred when urine testing gave way to capillary blood home glucose monitoring. As improvements were made to these devices, continuous glucose monitoring (CGM) was introduced. The advantages of experiential learnings gleaned from seeing continuous real-time data have been borne out in numerous peer-reviewed journals. Limitations to use of CGM include patient's level of numeracy and literacy, development of alarm fatigue, interfering substances leading to erroneous readings, high rates of discontinuation, and poor reimbursement. PMID:26983025

  18. Detection of Trace Glucose on the Surface of a Semipermeable Membrane Using a Fluorescently Labeled Glucose-Binding Protein: A Promising Approach to Noninvasive Glucose Monitoring

    PubMed Central

    Ge, Xudong; Rao, Govind; Kostov, Yordan; Kanjananimmanont, Sunsanee; Viscardi, Rose M.; Woo, Hyung; Tolosa, Leah

    2013-01-01

    Background Our motivation for this study was to develop a noninvasive glucose sensor for low birth weight neonates. We hypothesized that the underdeveloped skin of neonates will allow for the diffusion of glucose to the surface where it can be sampled noninvasively. On further study, we found that measurable amounts of glucose can also be collected on the skin of adults. Method Cellulose acetate dialysis membrane was used as surrogate for preterm neonatal skin. Glucose on the surface was collected by saline-moistened swabs and analyzed with glucose-binding protein (GBP). The saline-moistened swab was also tested in the neonatal intensive care unit. Saline was directly applied on adult skin and collected for analysis with two methods: GBP and high-performance anion-exchange chromatography (HPAEC). Results The amount of glucose on the membrane surface was found (1) to accumulate with time but gradually level off, (2) to be proportional to the swab dwell time, and (3) the concentration of the glucose solution on the opposite side of the membrane. The swab, however, failed to absorb glucose on neonatal skin. On direct application of saline onto adult skin, we were able to measure by HPAEC and GBP the amount of glucose collected on the surface. Blood glucose appears to track transdermal glucose levels. Conclusions We were able to measure trace amounts of glucose on the skin surface that appear to follow blood glucose levels. The present results show modest correlation with blood glucose. Nonetheless, this method may present a noninvasive alternative to tracking glucose trends. PMID:23439155

  19. Effects of Different Proportion of Carbohydrate in Breakfast on Postprandial Glucose Excursion in Normal Glucose Tolerance and Impaired Glucose Regulation Subjects

    PubMed Central

    Kang, Xin; Wang, Chun; Lifang, Lv; Chen, Dawei; Yang, Yanzhi; Liu, Guanjian; Wen, Hu; Chen, Lihong; He, Liping; Li, Xiujun; Tian, Haoming; Jia, Weiping

    2013-01-01

    Abstract Background The variability of postprandial plasma glucose is an independent risk factor for diabetes. The type and amount of carbohydrate may be important determinants of glycemic control. The aim of the study was to compare the effects of different proportions of carbohydrate in breakfast on postprandial blood glucose fluctuations in impaired glucose regulation (IGR) and normal glucose tolerance (NGT) subjects. Subjects and Methods This is a cross-sectional study of two groups including 55 subjects with IGR and 78 individuals with NGT. Their recorded breakfast was sorted into low-carbohydrate (LC) (carbohydrate <45%), medium-carbohydrate (MC) (carbohydrate 45–65%), and high-carbohydrate (HC) (carbohydrate >65%) meals according to the proportion of carbohydrate. Glucose concentrations were continuously measured with a continuous glucose monitoring system, and parameters such as the incremental area under the curve (iAUC) of glucose and postprandial glucose excursion (PPGE) were calculated to evaluate postprandial glucose fluctuations. Results The postprandial fluctuations of glucose increased gradually with increased proportions of carbohydrate in breakfast in both IGR and NGT subjects. For the MC and HC meals, iAUC, PPGE, postprandial glucose spike (PGS), and mean blood glucose were significantly greater than those in the NGT group (P<0.05), respectively. The median time to PGS and the time period in which glucose concentrations decreased to baseline after the MC and HC meals in the IGR group were significantly longer than those in the NGT group (P<0.01), respectively. Compared with the NGT subjects for the HC meal, the IGR subjects consuming the MC meal had greater PGS, range of glucose concentrations, SD, and PPGE (P<0.05). Conclusions The proportion of carbohydrate in breakfast contributes to glucose excursions in the NGT and IGR subjects. In the IGR subjects, a HC meal should be avoided and a LC meal should be recommended to prevent development of

  20. A glucose-sensing contact lens: a new approach to noninvasive continuous physiological glucose monitoring

    NASA Astrophysics Data System (ADS)

    Badugu, Ramachandram; Lakowicz, Joseph R.; Geddes, Chris D.

    2004-06-01

    We have developed a new technology for the non-invasive continuous monitoring of tear glucose using a daily use, disposable contact lens, embedded with sugar-sensing boronic acid containing fluorophores. Our findings show that our approach may be suitable for the continuous monitoring of tear glucose levels in the range 50 - 500 μM, which track blood glucose levels that are typically ~ 5-10 fold higher. We initially tested the sensing concept with well-established, previously published, boronic acid probes and the results could conclude the used probes, with higher pKa values, are almost insensitive toward glucose within the contact lens, attributed to the low pH and polarity inside the lens. Subsequently, we have developed a range of probes based on the quinolinium backbone, having considerably lower pKa values, which enables them to be suitable to sense the physiological glucose in the acidic pH contact lens. Herein we describe the results based on our findings towards the development of glucose sensing contact lens and therefore an approach to non-invasive continuous monitoring of tear glucose using a contact lens.

  1. Glucose oxidase-functionalized fluorescent gold nanoclusters as probes for glucose.

    PubMed

    Xia, Xiaodong; Long, Yunfei; Wang, Jianxiu

    2013-04-15

    Creation and application of noble metal nanoclusters have received continuous attention. By integrating enzyme activity and fluorescence for potential applications, enzyme-capped metal clusters are more desirable. This work demonstrated a glucose oxidase (an enzyme for glucose)-functionalized gold cluster as probe for glucose. Under physiological conditions, such bioconjugate was successfully prepared by an etching reaction, where tetrakis (hydroxylmethyl) phosphonium-protected gold nanoparticle and thioctic acid-modified glucose oxidase were used as precursor and etchant, respectively. These bioconjugates showed unique fluorescence spectra (λ(em max)=650 nm, λ(ex max)=507 nm) with an acceptable quantum yield (ca. 7%). Moreover, the conjugated glucose oxidase remained active and catalyzed reaction of glucose and dissolved O2 to produce H2O2, which quenched quantitatively the fluorescence of gold clusters and laid a foundation of glucose detection. A linear range of 2.0×10(-6)-140×10(-6)M and a detection limit of 0.7×10(-6)M (S/N=3) were obtained. Also, another horseradish peroxidase/gold cluster bioconjugate was produced by such general synthesis method. Such enzyme/metal cluster bioconjugates represented a promising class of biosensors for biologically important targets in organelles or cells. PMID:23540251

  2. Direct electron transfer type disposable sensor strip for glucose sensing employing an engineered FAD glucose dehydrogenase.

    PubMed

    Yamashita, Yuki; Ferri, Stefano; Huynh, Mai Linh; Shimizu, Hitomi; Yamaoka, Hideaki; Sode, Koji

    2013-02-01

    The FAD-dependent glucose dehydrogenase (FADGDH) from Burkholderia cepacia has several attractive features for glucose sensing. However, expanding the application of this enzyme requires improvement of its substrate specificity, especially decreasing its high activity toward maltose. A three-dimensional structural model of the FADGDH catalytic subunit was generated by homology modeling. By comparing the predicted active site with that of glucose oxidase, the two amino acid residues serine 326 and serine 365 were targeted for site-directed mutagenesis. The single mutations that produced the highest glucose specificity were combined, leading to the creation of the S326Q/S365Y double mutant, which was virtually nonreactive to maltose while retaining high glucose dehydrogenase activity. The engineered FADGDH was used to develop a direct electron transfer-type, disposable glucose sensor strip by immobilizing the enzyme complex onto a carbon screen-printed electrode. While the electrode employing wild-type FADGDH provided dangerously flawed results in the presence of maltose, the sensor employing our engineered FADGDH showed a clear glucose concentration-dependent response that was not affected by the presence of maltose. PMID:23273282

  3. Antipsychotics inhibit glucose transport: Determination of olanzapine binding site in Staphylococcus epidermidis glucose/H+ symporter

    PubMed Central

    Babkin, Petr; George Thompson, Alayna M.; Iancu, Cristina V.; Walters, D. Eric; Choe, Jun-yong

    2015-01-01

    The antipsychotic drug olanzapine is widely prescribed to treat schizophrenia and other psychotic disorders. However, it often causes unwanted side effects, including diabetes, due to disruption of insulin-dependant glucose metabolism through a mechanism yet to be elucidated. To determine if olanzapine can affect the first step in glucose metabolism – glucose transport inside cells – we investigated the effect of this drug on the transport activity of a model glucose transporter. The glucose transporter from Staphylococcus epidermidis (GlcPSe) is specific for glucose, inhibited by various human glucose transporter (GLUT) inhibitors, has high sequence and structure homology to GLUTs, and is readily amenable to transport assay, mutagenesis, and computational modeling. We found that olanzapine inhibits glucose transport of GlcPSe with an IC50 0.9 ± 0.1 mM. Computational docking of olanzapine to the GlcPSe structure revealed potential binding sites that were further examined through mutagenesis and transport assay to identify residues important for olanzapine inhibition. These investigations suggest that olanzapine binds in a polar region of the cytosolic part of the transporter, and interacts with residues R129, strictly conserved in all GLUTs, and N136, conserved in only a few GLUTs, including the insulin-responsive GLUT4. We propose that olanzapine inhibits GlcPSe by impeding the alternating opening and closing of the substrate cavity necessary for glucose transport. It accomplishes this by disrupting a key salt bridge formed by conserved residues R129 and E362, that stabilizes the outward-facing conformation of the transporter. PMID:25941630

  4. Antipsychotics inhibit glucose transport: Determination of olanzapine binding site in Staphylococcus epidermidis glucose/H(+) symporter.

    PubMed

    Babkin, Petr; George Thompson, Alayna M; Iancu, Cristina V; Walters, D Eric; Choe, Jun-Yong

    2015-01-01

    The antipsychotic drug olanzapine is widely prescribed to treat schizophrenia and other psychotic disorders. However, it often causes unwanted side effects, including diabetes, due to disruption of insulin-dependant glucose metabolism through a mechanism yet to be elucidated. To determine if olanzapine can affect the first step in glucose metabolism - glucose transport inside cells - we investigated the effect of this drug on the transport activity of a model glucose transporter. The glucose transporter from Staphylococcus epidermidis (GlcPSe) is specific for glucose, inhibited by various human glucose transporter (GLUT) inhibitors, has high sequence and structure homology to GLUTs, and is readily amenable to transport assay, mutagenesis, and computational modeling. We found that olanzapine inhibits glucose transport of GlcPSe with an IC50 0.9 ± 0.1 mM. Computational docking of olanzapine to the GlcPSe structure revealed potential binding sites that were further examined through mutagenesis and transport assay to identify residues important for olanzapine inhibition. These investigations suggest that olanzapine binds in a polar region of the cytosolic part of the transporter, and interacts with residues R129, strictly conserved in all GLUTs, and N136, conserved in only a few GLUTs, including the insulin-responsive GLUT4. We propose that olanzapine inhibits GlcPSe by impeding the alternating opening and closing of the substrate cavity necessary for glucose transport. It accomplishes this by disrupting a key salt bridge formed by conserved residues R129 and E362, that stabilizes the outward-facing conformation of the transporter. PMID:25941630

  5. Localized surface plasmon resonance of silver nanoisland based glucose sensor

    NASA Astrophysics Data System (ADS)

    Venugopal, N.; Mitra, Anirban

    2013-06-01

    Study of optical properties of glucose is an attractive research topic for years. One of the goals is to develop a portable device for simple, reliable, cost effective and non-invasive monitoring of glucose in blood for diabetics. In this work, we study localized surface plasmon resonance (LSPR) of Ag nanoisland based glucose sensor. The progressive shift in LSPR caused by the various concentration of glucose from 2M to 10M has been investigated to monitor the sensing property. We correlate the redshift of LSPR is due to the change in refractive index of surrounding glucose medium. Preliminary results show that this may possibly reveal a new pathway for sensing glucose.

  6. Variability of capillary blood glucose monitoring measured on home glucose monitoring devices

    PubMed Central

    Kotwal, Narendra; Pandit, Aditi

    2012-01-01

    Self monitoring of blood glucose helps achieve glycemic goals. Glucometers must be accurate. Many variables affect blood glucose levels. Factors are analytical variables (intrinsic to glucometer and glucose strips) and pre analytical related to patients. Analytical variables depend on factors like shelf life, amount of blood and enzymatic reactions. Preanalytical variables include pH of blood, hypoxia, hypotension, hematocrit etc. CGMS has the potential to revolutionise diabetes care but accuracy needs to be proven beyond doubt before replacing current glucometer devices. PMID:23565391

  7. Glucose metabolism in pregnant sheep when placental growth is restricted

    SciTech Connect

    Owens, J.A.; Falconer, J.; Robinson, J.S. )

    1989-08-01

    The effect of restricting placental growth on glucose metabolism in pregnant sheep in late gestation was determined by primed constant infusions of D-(U-{sup 14}C)- and D-(2-{sup 3}H)glucose and antipyrine into fetuses of six control sheep and six sheep from which endometrial caruncles had been removed before pregnancy (caruncle sheep). In the latter, placental and fetal weights were reduced, as was the concentration of glucose in fetal arterial blood. Fetal glucose turnover in caruncle sheep was only 52-59% of that in controls, largely because of lower umbilical loss of glucose back to the placenta (38-39% of control) and lower fetal glucose utilization (61-74% of control). However, fetal glucose utilization on a weight-specific basis was similar in control and caruncle sheep. Significant endogenous glucose production occurred in control and caruncle fetal sheep. Maternal glucose production and partition of glucose between the gravid uterus and other maternal tissues were similar in control and caruncle sheep. In conclusion, when placental and fetal growth are restricted, fetal glucose utilization is maintained by reduced loss of glucose back to the placenta and mother and by maintaining endogenous glucose production.

  8. Screening and Diagnosis of Gestational Diabetes Mellitus, Where Do We Stand.

    PubMed

    Rani, P Reddi; Begum, Jasmina

    2016-04-01

    Gestational Diabetes Mellitus (GDM) is defined as any glucose intolerance with the onset or first recognition during pregnancy. This definition helps for diagnosis of unrecognized pre-existing Diabetes also. Hyperglycemia in pregnancy is associated with adverse maternal and prenatal outcome. It is important to screen, diagnose and treat Hyperglycemia in pregnancy to prevent an adverse outcome. There is no international consensus regarding timing of screening method and the optimal cut-off points for diagnosis and intervention of GDM. DIPSI recommends non-fasting Oral Glucose Tolerance Test (OGTT) with 75g of glucose with a cut-off of ≥ 140 mg/dl after 2-hours, whereas WHO (1999) recommends a fasting OGTT after 75g glucose with a cut-off plasma glucose of ≥ 140 mg/dl after 2-hour. The recommendations by ADA/IADPSG for screening women at risk of diabetes is as follows, for first and subsequent trimester at 24-28 weeks a criteria of diagnosis of GDM is made by 75 g OGTT and fasting 5.1mmol/l, 1 hour 10.0mmol/l, 2 hour 8.5mmol/l by universal glucose tolerance testing. Critics of these criteria state that it causes over diagnosis of GDM and unnecessary interventions, the controversy however continues. The ACOG still prefer a 2 step procedure, GCT with 50g glucose non-fasting if value > 7.8mmol/l followed by 3-hour OGTT for confirmation of diagnosis. In conclusion based on Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study as mild degree of dysglycemia are associated with adverse outcome and high prevalence of Type II DM to have international consensus It recommends IADPSG criteria, though controversy exists. The IADPSG criteria is the only outcome based criteria, it has the ability to diagnose and treat GDM earlier, thereby reducing the fetal and maternal complications associated with GDM. This one step method has an advantage of simplicity in execution, more patient friendly, accurate in diagnosis and close to international consensus. Keeping in the mind the

  9. Screening and Diagnosis of Gestational Diabetes Mellitus, Where Do We Stand

    PubMed Central

    Rani, P. Reddi

    2016-01-01

    Gestational Diabetes Mellitus (GDM) is defined as any glucose intolerance with the onset or first recognition during pregnancy. This definition helps for diagnosis of unrecognized pre-existing Diabetes also. Hyperglycemia in pregnancy is associated with adverse maternal and prenatal outcome. It is important to screen, diagnose and treat Hyperglycemia in pregnancy to prevent an adverse outcome. There is no international consensus regarding timing of screening method and the optimal cut-off points for diagnosis and intervention of GDM. DIPSI recommends non-fasting Oral Glucose Tolerance Test (OGTT) with 75g of glucose with a cut-off of ≥ 140 mg/dl after 2-hours, whereas WHO (1999) recommends a fasting OGTT after 75g glucose with a cut-off plasma glucose of ≥ 140 mg/dl after 2-hour. The recommendations by ADA/IADPSG for screening women at risk of diabetes is as follows, for first and subsequent trimester at 24-28 weeks a criteria of diagnosis of GDM is made by 75 g OGTT and fasting 5.1mmol/l, 1 hour 10.0mmol/l, 2 hour 8.5mmol/l by universal glucose tolerance testing. Critics of these criteria state that it causes over diagnosis of GDM and unnecessary interventions, the controversy however continues. The ACOG still prefer a 2 step procedure, GCT with 50g glucose non-fasting if value > 7.8mmol/l followed by 3-hour OGTT for confirmation of diagnosis. In conclusion based on Hyperglycemia and Adverse Pregnancy Outcome (HAPO) study as mild degree of dysglycemia are associated with adverse outcome and high prevalence of Type II DM to have international consensus It recommends IADPSG criteria, though controversy exists. The IADPSG criteria is the only outcome based criteria, it has the ability to diagnose and treat GDM earlier, thereby reducing the fetal and maternal complications associated with GDM. This one step method has an advantage of simplicity in execution, more patient friendly, accurate in diagnosis and close to international consensus. Keeping in the mind the

  10. Regulation of Glucose Homeostasis by GLP-1

    PubMed Central

    Nadkarni, Prashant; Chepurny, Oleg G.; Holz, George G.

    2014-01-01

    Glucagon-like peptide-1(7–36)amide (GLP-1) is a secreted peptide that acts as a key determinant of blood glucose homeostasis by virtue of its abilities to slow gastric emptying, to enhance pancreatic insulin secretion, and to suppress pancreatic glucagon secretion. GLP-1 is secreted from L cells of the gastrointestinal mucosa in response to a meal, and the blood glucose-lowering action of GLP-1 is terminated due to its enzymatic degradation by dipeptidyl-peptidase-IV (DPP-IV). Released GLP-1 activates enteric and autonomic reflexes while also circulating as an incretin hormone to control endocrine pancreas function. The GLP-1 receptor (GLP-1R) is a G protein-coupled receptor that is activated directly or indirectly by blood glucose-lowering agents currently in use for the treatment of type 2 diabetes mellitus (T2DM). These therapeutic agents include GLP-1R agonists (exenatide, liraglutide, lixisenatide, albiglutide, dulaglutide, and langlenatide) and DPP-IV inhibitors (sitagliptin, vildagliptin, saxagliptin, linagliptin, and alogliptin). Investigational agents for use in the treatment of T2DM include GPR119 and GPR40 receptor agonists that stimulate the release of GLP-1 from L cells. Summarized here is the role of GLP-1 to control blood glucose homeo-stasis, with special emphasis on the advantages and limitations of GLP-1-based therapeutics. PMID:24373234

  11. Glucose regulates amyloid β production via AMPK.

    PubMed

    Yang, Ting-Ting; Shih, Yao-Shan; Chen, Yun-Wen; Kuo, Yu-Min; Lee, Chu-Wan

    2015-10-01

    Alzheimer's disease (AD) is the most common form of dementia in the elderly. Accumulation of Aβ peptides in the brain has been suggested as the cause of AD (amyloid cascade hypothesis); however, the mechanism for the abnormal accumulation of Aβ in the brains of AD patients remains unclear. A plethora of evidence has emerged to support a link between metabolic disorders and AD. This study was designed to examine the relationship between energy status and Aβ production. Neuro 2a neuroblastoma cells overexpressing human amyloid precursor protein 695 (APP cells) were cultured in media containing different concentrations of glucose and agonist or antagonist of AMP-activated-protein-kinase (AMPK), a metabolic master sensor. The results showed that concentrations of glucose in the culture media were negatively associated with the activation statuses of AMPK in APP cells, but positively correlated with the levels of secreted Aβ. Modulating AMPK activities affected the production of Aβ. If APP cells were cultured in high glucose medium (i.e., AMPK was inactive), stimulation of AMPK activity decreased the production levels of Aβ. On the contrary, if APP cells were incubated in medium containing no glucose (i.e., AMPK was activated), inhibition of AMPK activity largely increased Aβ production. As AMPK activation is a common defect in metabolic abnormalities, our study supports the premise that metabolic disorders may aggravate AD pathogenesis. PMID:26071020

  12. Clean conversion of cellulose into fermentable glucose.

    PubMed

    Sun, Yong; Zhuang, Junping; Lin, Lu; Ouyang, Pingkai

    2009-01-01

    We studied the process of conversion of microcrystalline-cellulose into fermentable glucose in the formic acid reaction system using cross polarization/magic angle spinning (13)C-nuclear magnetic resonance, X-ray diffraction and Fourier transform infrared spectroscopy. The results indicated that formic acid as an active agent was able to effectively penetrate into the interior space of the cellulose molecules, thus collapsing the rigid crystalline structure and allowing hydrolysis to occur easily in the amorphous zone as well as in the crystalline zone. The microcrystalline-cellulose was hydrolyzed using formic acid and 4% hydrochloric acid under mild conditions. The effects of hydrochloric acid concentration, the ratio of solid to liquid, temperature (55-75 degrees C) and retention time (0-9 h), and the concentration of glucose were analyzed. The hydrolysis velocities of microcrystalline-cellulose were 6.14 x 10(-3) h(-1) at 55 degrees C, 2.94 x 10(-2) h(-1) at 65 degrees C, and 6.84x10(-2) h(-1) at 75 degrees C. The degradation velocities of glucose were 0.01 h(-1) at 55 degrees C, 0.14 h(-1) at 65 degrees C, 0.34 h(-1) at 75 degrees C. The activation energy of microcrystalline-cellulose hydrolysis was 105.61 kJ/mol, and the activation energy of glucose degradation was 131.37 kJ/mol. PMID:19409478

  13. Design of nanostructured-based glucose biosensors

    NASA Astrophysics Data System (ADS)

    Komirisetty, Archana; Williams, Frances; Pradhan, Aswini; Konda, Rajini B.; Dondapati, Hareesh; Samantaray, Diptirani

    2012-04-01

    This paper presents the design of glucose sensors that will be integrated with advanced nano-materials, bio-coatings and electronics to create novel devices that are highly sensitive, inexpensive, accurate, and reliable. In the work presented, a glucose biosensor and its fabrication process flow have been designed. The device is based on electrochemical sensing using a working electrode with bio-functionalized zinc oxide (ZnO) nano-rods. Among all metal oxide nanostructures, ZnO nano-materials play a significant role as a sensing element in biosensors due to their properties such as high isoelectric point (IEP), fast electron transfer, non-toxicity, biocompatibility, and chemical stability which are very crucial parameters to achieve high sensitivity. Amperometric enzyme electrodes based on glucose oxidase (GOx) are used due to their stability and high selectivity to glucose. The device also consists of silicon dioxide and titanium layers as well as platinum working and counter electrodes and a silver/silver chloride reference electrode. Currently, the biosensors are being fabricated using the process flow developed. Once completed, the sensors will be bio-functionalized and tested to characterize their performance, including their sensitivity and stability.

  14. Psoriatic therapeutics and glucose-6-phosphate dehydrogenase.

    PubMed

    Cotton, D W; van Rossum, E

    1975-01-01

    The inhibitory effects of various agents on the enzyme glucose-6-phosphate dehydrogenase have been studied in vitro. Stress is laid on the calculation of kinetic parameters such as true K-I values. The most active inhibitor was methotrexate, closely followed by cGMP. The increase in inhibitory activity after incubation of methotrexate with liver slices is discussed. PMID:167665

  15. Diabetic neuropathy and plasma glucose control.

    PubMed

    Porte, D; Graf, R J; Halter, J B; Pfeifer, M A; Halar, E

    1981-01-01

    Diabetic neuropathy is defined, and theories of its pathogenesis are reviewed. Recent studies designed to investigate the influence of plasma glucose on nerve function in noninsulin-dependent diabetic patients are summarized. Motor nerve conduction velocities in the median and peroneal nerves were measured using a double-stimulus technique, and sensory conduction velocity was measured by conventional methods before and after therapy with oral agents or insulin. The degree of hyperglycemia was assessed by measurement of fasting plasma glucose and glycosylated hemoglobin concentrations. The degree of slowing in motor nerve conduction velocity in untreated patients was found to correlate with the fasting plasma glucose and glycosylated hemoglobin concentrations, but sensory nerve function, although abnormal, did not show such correlation. Reduction of hyperglycemia was associated with improvement in motor nerve conduction velocity in the peroneal and median motor nerves of these patients, but sensory nerve conduction velocity showed no such improvement. Improvement in median motor nerve conduction velocity was directly related to the degree of reduction in fasting plasma glucose concentration. These findings suggest that metabolic factors related to hyperglycemia are important in the impaired motor nerve function seen in noninsulin-dependent patients with maturity-onset diabetes. PMID:7457487

  16. Enzymatic production of hydrogen from glucose

    SciTech Connect

    Woodward, J.; Mattingly, S.M.

    1995-06-01

    The objective of this research is to optimize conditions for the enzymatic production of hydrogen gas from biomass-derived glucose. This new project is funded at 0.5 PY level of effort for FY 1995. The rationale for the work is that cellulose is, potentially, a vast source of hydrogen and that enzymes offer a specific and efficient method for its extraction with minimal environmental impact. This work is related to the overall hydrogen program goal of technology development and validation. The approach is based on knowledge that glucose is oxidized by the NADP{sup +} requiring enzyme glucose dehydrogenase (GDH) and that the resulting NADPH can donate its electrons to hydrogenase (H{sub 2}ase) which catalyzes the evolution of H{sub 2}. Thus hydrogen production from glucose was achieved using calf liver GDH and Pyrococcus furiosus H{sub 2}ase yielding 17% of theoretical maximum expected. The cofactor NADP{sup +} for this reaction was regenerated and recycled. Current and future work includes understanding the rate limiting steps of this process and the stabilization/immobilization of the enzymes for long term hydrogen production. Cooperative interactions with the Universities of Georgia and Bath for obtaining thermally stable enzymes are underway.

  17. Enzymatic production of hydrogen from glucose

    NASA Astrophysics Data System (ADS)

    Woodward, J.; Mattingly, S. M.

    The objective of this research is to optimize conditions for the enzymatic production of hydrogen gas from biomass-derived glucose. This new project is funded at 0.5 PY level of effort for FY 1995. The rationale for the work is that cellulose is, potentially, a vast source of hydrogen and that enzymes offer a specific and efficient method for its extraction with minimal environmental impact. This work is related to the overall hydrogen program goal of technology development and validation. The approach is based on knowledge that glucose is oxidized by the NADP(sup +) requiring enzyme glucose dehydrogenase (GDH) and that the resulting NADPH can donate its electrons to hydrogenase (H2ase) which catalyzes the evolution of H2. Thus hydrogen production from glucose was achieved using calf liver GDH and Pyrococcus furiosus H2ase yielding 17% of theoretical maximum expected. The cofactor NADP(sup +) for this reaction was regenerated and recycled. Current and future work includes understanding the rate limiting steps of this process and the stabilization/immobilization of the enzymes for long term hydrogen production. Cooperative interactions with the Universities of Georgia and Bath for obtaining thermally sta

  18. Glucose Fermentation Pathway of Thermoanaerobium brockii

    PubMed Central

    Lamed, R.; Zeikus, J. G.

    1980-01-01

    Thermoanaerobium brockii was shown to catabolize glucose via the Embden-Meyerhof-Parnas pathway into ethanol, acetic acid, H2-CO2, and lactic acid. Radioactive tracer studies, employing specifically labeled [14C]glucose, demonstrated significant fermentation of 14CO2 from C-3 and C-4 of the substrate exclusively. All extracts contained sufficient levels of activity (expressed in micromoles per minute per milligram of protein at 40°C) to assign a catabolic role for the following enzymes: glucokinase, 0.40; fructose-1,6-diphosphate aldolase, 0.23; glyceraldehyde-3-phosphate dehydrogenase, 1.73; pyruvate kinase, 0.36; lactate dehydrogenase (fructose-1,6-diphosphate activated), 0.55; pyruvate dehydrogenase (coenzyme A acetylating), 0.53; hydrogenase, 3.3; phosphotransacetylase, 0.55; acetaldehyde dehydrogenase (coenzyme A acetylating), 0.15; ethanol dehydrogenase, 1.57; and acetate kinase, 1.50. All pyridine nucleotide-linked oxidoreductases examined were specific for nicotinamide adenine dinucleotide, except ethanol dehydrogenase which displayed both nicotinamide adenine dinucleotide- and nicotinamide adenine dinucleotide phosphate-linked activities. Fermentation product balances and cell growth yields supported the glucose catabolic pathway described. Representative balanced end product yields (in moles per mole of glucose fermented) were: ethanol, 0.94; l-lactate, 0.84; acetate, 0.20; CO2, 1.31; and H2, 0.50. Growth yields of 16.4 g of cells per mole of glucose were demonstrated. Both growth and end product yields varied significantly in accordance with the specific medium composition and incubation time. PMID:6767705

  19. Fabrication of Amperometric Glucose Sensor Using Glucose Oxidase-Cellulose Nanofiber Aqueous Solution.

    PubMed

    Yasuzawa, Mikito; Omura, Yuya; Hiura, Kentaro; Li, Jiang; Fuchiwaki, Yusuke; Tanaka, Masato

    2015-01-01

    Cellulose nanofiber aqueous solution, which remained virtually transparent for more than one week, was prepared by using the clear upper layer of diluted cellulose nanofiber solution produced by wet jet milling. Glucose oxidase (GOx) was easily dissolved in this solution and GOx-immobilized electrode was easily fabricated by simple repetitious drops of GOx-cellulose solution on the surface of a platinum-iridium electrode. Glucose sensor properties of the obtained electrodes were examined in phosphate buffer solution of pH 7.4 at 40°C. The obtained electrode provided a glucose sensor response with significantly high response speed and good linear relationship between glucose concentration and response current. After an initial decrease of response sensitivity for a few days, relatively constant sensitivity was obtained for about 20 days. Nevertheless, the influence of electroactive compounds such as ascorbic acid, uric acid and acetoaminophen were not negletable. PMID:26561252

  20. Increased airway glucose increases airway bacterial load in hyperglycaemia

    PubMed Central

    Gill, Simren K.; Hui, Kailyn; Farne, Hugo; Garnett, James P.; Baines, Deborah L.; Moore, Luke S.P.; Holmes, Alison H.; Filloux, Alain; Tregoning, John S.

    2016-01-01

    Diabetes is associated with increased frequency of hospitalization due to bacterial lung infection. We hypothesize that increased airway glucose caused by hyperglycaemia leads to increased bacterial loads. In critical care patients, we observed that respiratory tract bacterial colonisation is significantly more likely when blood glucose is high. We engineered mutants in genes affecting glucose uptake and metabolism (oprB, gltK, gtrS and glk) in Pseudomonas aeruginosa, strain PAO1. These mutants displayed attenuated growth in minimal medium supplemented with glucose as the sole carbon source. The effect of glucose on growth in vivo was tested using streptozocin-induced, hyperglycaemic mice, which have significantly greater airway glucose. Bacterial burden in hyperglycaemic animals was greater than control animals when infected with wild type but not mutant PAO1. Metformin pre-treatment of hyperglycaemic animals reduced both airway glucose and bacterial load. These data support airway glucose as a critical determinant of increased bacterial load during diabetes. PMID:27273266

  1. Rapid and specific isolation of radioactive glucose from biological samples.

    PubMed

    Mills, S E; Armentano, L E; Russell, R W; Young, J W

    1981-08-01

    An easy, reliable, and specific ion-exchange method is presented for isolating glucose for specific radioactivity determinations from both blood plasma and buffered in vitro incubation media. The use of a glucose binding resin (borate-charged anion resin) combined speed of ion exchange with specificity of derivative formation. Glucose specific radioactivities, determined by ion exchange on protein-free filtrates of plasma containing [carbon-14] glucose, show excellent agreement with those from the popular glucose pentaacetate derivative method and are less variable. Carry-over of labeled acetate, propionate, lactate, glyoxylate, alanine, aspartate, or glutamate into the glucose fraction is less than .2%. Glycerol carryover is 1.2%. Glucose recovery is increased about three times that of the glucose pentaacetate derivative method and averaged 94% from plasma filtrates. PMID:7298970

  2. Increased airway glucose increases airway bacterial load in hyperglycaemia.

    PubMed

    Gill, Simren K; Hui, Kailyn; Farne, Hugo; Garnett, James P; Baines, Deborah L; Moore, Luke S P; Holmes, Alison H; Filloux, Alain; Tregoning, John S

    2016-01-01

    Diabetes is associated with increased frequency of hospitalization due to bacterial lung infection. We hypothesize that increased airway glucose caused by hyperglycaemia leads to increased bacterial loads. In critical care patients, we observed that respiratory tract bacterial colonisation is significantly more likely when blood glucose is high. We engineered mutants in genes affecting glucose uptake and metabolism (oprB, gltK, gtrS and glk) in Pseudomonas aeruginosa, strain PAO1. These mutants displayed attenuated growth in minimal medium supplemented with glucose as the sole carbon source. The effect of glucose on growth in vivo was tested using streptozocin-induced, hyperglycaemic mice, which have significantly greater airway glucose. Bacterial burden in hyperglycaemic animals was greater than control animals when infected with wild type but not mutant PAO1. Metformin pre-treatment of hyperglycaemic animals reduced both airway glucose and bacterial load. These data support airway glucose as a critical determinant of increased bacterial load during diabetes. PMID:27273266

  3. Sodium-Glucose Cotransporter Inhibitors: Effects on Renal and Intestinal Glucose Transport: From Bench to Bedside.

    PubMed

    Mudaliar, Sunder; Polidori, David; Zambrowicz, Brian; Henry, Robert R

    2015-12-01

    Type 2 diabetes is a chronic disease with disabling micro- and macrovascular complications that lead to excessive morbidity and premature mortality. It affects hundreds of millions of people and imposes an undue economic burden on populations across the world. Although insulin resistance and insulin secretory defects play a major role in the pathogenesis of hyperglycemia, several other metabolic defects contribute to the initiation/worsening of the diabetic state. Prominent among these is increased renal glucose reabsorption, which is maladaptive in patients with diabetes. Instead of an increase in renal glucose excretion, which could ameliorate hyperglycemia, there is an increase in renal glucose reabsorption, which helps sustain hyperglycemia in patients with diabetes. The sodium-glucose cotransporter (SGLT) 2 inhibitors are novel antidiabetes agents that inhibit renal glucose reabsorption and promote glucosuria, thereby leading to reductions in plasma glucose concentrations. In this article, we review the long journey from the discovery of the glucosuric agent phlorizin in the bark of the apple tree through the animal and human studies that led to the development of the current generation of SGLT2 inhibitors. PMID:26604280

  4. Glucose oxidase-mediated gelation: a simple test to detect glucose in food products.

    PubMed

    Liu, Yi; Javvaji, Vishal; Raghavan, Srinivasa R; Bentley, William E; Payne, Gregory F

    2012-09-12

    This paper reports a simple, rapid, and sugar-selective method to induce gelation from glucose-containing samples. This method employs glucose oxidase (GOx) to selectively "recognize" and oxidize glucose to generate gluconic acid, which acts to solubilize calcium carbonate and release calcium ions. The release of calcium ions triggers gelation of the calcium-responsive polysaccharide alginate to form a calcium-alginate hydrogel. Rheological measurements confirm that gel formation is triggered by glucose but not fructose or sucrose (consistent with GOx's selectivity). Vial inversion tests demonstrate that gel formation can be readily observed without the need for instrumentation. Proof-of-concept studies demonstrate that this gel-forming method can detect glucose in food/beverage products sweetened with glucose or high-fructose corn syrups. These results indicate that the enzyme-induced gelation of alginate may provide a simple means to test for sweeteners using components that are safe for use on-site or in the home. PMID:22906038

  5. Noninvasive technique for measurement of glucose content in body

    NASA Astrophysics Data System (ADS)

    Agapiou, George; Theofanous, N. G.

    1998-07-01

    This work is focused on the measurement of glucose in various diluted solutions and aims to be implemented in testing the glucose content in the anterior chamber of the eye by means of an electro-optic modulation method. By using solutions containing only glucose concentrations, a calibration curve displaying the dependence of the glucose concentration on a DC field, applied to a modulator, was obtained.

  6. Modeling of glucose pH enzyme electrode

    SciTech Connect

    Sarbolouki, M.N.; Ghoorchian, H.; Mozaffari, S. )

    1990-08-01

    Fabrication of a modified glucose pH enzyme electrode, using cellulose acetate instead of cellophane, and its performance are described. A physico-mathematical model that considers glucose transport across the membrane from the bulk into the enzyme solution layer, subsequent proton generation as a consequence of glucose oxidation by the enzyme glucose oxidase, and proton transport back through the membrane into the bulk solution is developed. Proper rate equations are simultaneously solved. Experimental and theoretical results are compared.

  7. 21 CFR 184.1372 - Insoluble glucose isomerase enzyme preparations.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Insoluble glucose isomerase enzyme preparations... Substances Affirmed as GRAS § 184.1372 Insoluble glucose isomerase enzyme preparations. (a) Insoluble glucose isomerase enzyme preparations are used in the production of high fructose corn syrup described in §...

  8. Glucose cycling in islets from healthy and diabetic rats

    SciTech Connect

    Khan, A.; Chandramouli, V.; Ostenson, C.G.; Loew, H.L.; Landau, B.R.; Efendic, S. )

    1990-04-01

    Pancreatic islets from healthy (control) and neonatally streptozocin-induced diabetic (STZ-D) rats, a model for non-insulin-dependent diabetes mellitus, were incubated with {sup 3}H{sub 2}O and 5.5 or 16.7 mM glucose. At 5.5 mM glucose, no detectable ({sup 3}H)glucose was formed. At 16.7 mM, 2.2 patom.islet-1.h-1 of {sup 3}H was incorporated into glucose by the control islets and 5.4 patom.islet-1.h-1 by STZ-D islets. About 75% of the {sup 3}H was bound to carbon-2 of the glucose. Glucose utilization was 35.3 pmol.islet-1.h-1 by the control and 19.0 pmol.islet-1.h-1 by the STZ-D islets. Therefore, 4.5% of the glucose-6-phosphate formed by the control islets and 15.7% by the STZ-D islets was dephosphorylated. This presumably occurred in the beta-cells of the islets catalyzed by glucose-6-phosphatase. An increased glucose cycling, i.e., glucose----glucose-6-phosphate----glucose, in islets of STZ-D rats may contribute to the decreased insulin secretion found in these animals.

  9. 21 CFR 520.550 - Glucose/glycine/electrolyte.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Glucose/glycine/electrolyte. 520.550 Section 520...) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS ORAL DOSAGE FORM NEW ANIMAL DRUGS § 520.550 Glucose/glycine..., potassium citrate 0.12 gram, aminoacetic acid (glycine) 6.36 grams, and glucose 44.0 grams. (b) Sponsor....

  10. 21 CFR 184.1372 - Insoluble glucose isomerase enzyme preparations.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Insoluble glucose isomerase enzyme preparations... RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS § 184.1372 Insoluble glucose isomerase enzyme preparations. (a) Insoluble glucose isomerase enzyme preparations are used in the production...

  11. 21 CFR 184.1372 - Insoluble glucose isomerase enzyme preparations.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Insoluble glucose isomerase enzyme preparations... RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS § 184.1372 Insoluble glucose isomerase enzyme preparations. (a) Insoluble glucose isomerase enzyme preparations are used in the production...

  12. Glucose utilization rates regulate intake levels of artificial sweeteners

    PubMed Central

    Tellez, Luis A; Ren, Xueying; Han, Wenfei; Medina, Sara; Ferreira, Jozélia G; Yeckel, Catherine W; de Araujo, Ivan E

    2013-01-01

    It is well established that animals including humans attribute greater reinforcing value to glucose-containing sugars compared to their non-caloric counterparts, generally termed ‘artificial sweeteners’. However, much remains to be determined regarding the physiological signals and brain systems mediating the attribution of greater reinforcing value to sweet solutions that contain glucose. Here we show that disruption of glucose utilization in mice produces an enduring inhibitory effect on artificial sweetener intake, an effect that did not depend on sweetness perception or aversion. Indeed, such an effect was not observed in mice presented with a less palatable, yet caloric, glucose solution. Consistently, hungry mice shifted their preferences away from artificial sweeteners and in favour of glucose after experiencing glucose in a hungry state. Glucose intake was found to produce significantly greater levels of dopamine efflux compared to artificial sweetener in dorsal striatum, whereas disrupting glucose oxidation suppressed dorsal striatum dopamine efflux. Conversely, inhibiting striatal dopamine receptor signalling during glucose intake in sweet-naïve animals resulted in reduced, artificial sweetener-like intake of glucose during subsequent gluco-deprivation. Our results demonstrate that glucose oxidation controls intake levels of sweet tastants by modulating extracellular dopamine levels in dorsal striatum, and suggest that glucose utilization is one critical physiological signal involved in the control of goal-directed sweetener intake. PMID:24060992

  13. Glucose utilization rates regulate intake levels of artificial sweeteners.

    PubMed

    Tellez, Luis A; Ren, Xueying; Han, Wenfei; Medina, Sara; Ferreira, Jozélia G; Yeckel, Catherine W; de Araujo, Ivan E

    2013-11-15

    It is well established that animals including humans attribute greater reinforcing value to glucose-containing sugars compared to their non-caloric counterparts, generally termed 'artificial sweeteners'. However, much remains to be determined regarding the physiological signals and brain systems mediating the attribution of greater reinforcing value to sweet solutions that contain glucose. Here we show that disruption of glucose utilization in mice produces an enduring inhibitory effect on artificial sweetener intake, an effect that did not depend on sweetness perception or aversion. Indeed, such an effect was not observed in mice presented with a less palatable, yet caloric, glucose solution. Consistently, hungry mice shifted their preferences away from artificial sweeteners and in favour of glucose after experiencing glucose in a hungry state. Glucose intake was found to produce significantly greater levels of dopamine efflux compared to artificial sweetener in dorsal striatum, whereas disrupting glucose oxidation suppressed dorsal striatum dopamine efflux. Conversely, inhibiting striatal dopamine receptor signalling during glucose intake in sweet-naïve animals resulted in reduced, artificial sweetener-like intake of glucose during subsequent gluco-deprivation. Our results demonstrate that glucose oxidation controls intake levels of sweet tastants by modulating extracellular dopamine levels in dorsal striatum, and suggest that glucose utilization is one critical physiological signal involved in the control of goal-directed sweetener intake. PMID:24060992

  14. 21 CFR 862.1345 - Glucose test system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Glucose test system. 862.1345 Section 862.1345 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... glucose quantitatively in blood and other body fluids. Glucose measurements are used in the diagnosis...

  15. 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

  16. Effects of D-glucose, 2-deoxy-D-glucose and D-xylose on renal function in the rat.

    PubMed Central

    Garland, H O; Singh, H J

    1988-01-01

    1. Standard renal clearance techniques were used to investigate the effects of 2.5, 5 and 10% D-glucose, 2.5% 2-deoxy-D-glucose and 2.5% D-xylose on kidney function in male rats. 2. There was no consistent effect of D-glucose on urinary sodium output except with 10% D-glucose, where sodium excretion was raised compared to controls. 3. An increased urinary calcium output was seen in all D-glucose-infused rats compared to controls. Values obtained for 2.5, 5 and 10% glucose were respectively 32, 61 and 58% above control data. Neither 2-deoxy-D-glucose nor D-xylose produced a calciuresis. 4. The increased urinary calcium excretion in D-glucose rats was the result of a reduction in fractional calcium reabsorption. Glomerular filtration rate (GFR) was unchanged. It was not dependent upon glycosuria or a diuresis. PMID:3418534

  17. High Glucose and Glucose Deprivation Modulate Müller Cell Viability and VEGF Secretion

    PubMed Central

    Vellanki, S; Ferrigno, A; Alanis, Y; Betts-Obregon, BS; Tsin, AT

    2016-01-01

    Purpose Diabetic retinopathy is manifested by excessive angiogenesis and high level of vascular endothelial growth factor (VEGF) in the eye. Methods Human (MIO-M1) and rat (rMC-1) Müller cells were treated with 0, 5.5, or 30mM glucose for 24 hours. Viable cell counts were obtained by Trypan Blue Dye Exclusion Method. ELISA was used to determine VEGF levels in cell medium. Results Compared to 24 hour treatment by 5.5mM glucose, MIO-M1 and rMC-1 in 30mM glucose increased in viable cell number by 38% and 24% respectively. In contrast, viable cells in 0mM glucose decreased by 28% and 50% respectively. Compared to 5.5mM, MIO-M1 and rMC-1 in 30mM glucose had increased levels of VEGF in cell medium (pg/ml by 24% and 20%) and also VEGF concentration in cells held in 0mM increased by 47% and 10% respectively. In both MIO-M1 and rMC-1, the amount of VEGF secreted per cell increased by about 100% when glucose was changed from 5.5 to 0mM but decreased slightly (17% in MIO-M1 and 11% in rMC-1) when glucose was increased from 5.5 to 30mM. Conclusions Our results show that MIO-M1 and rMC-1 are highly responsive to changes in glucose concentrations. 30mM compared to 5.5mM significantly increased cell viability but induced a significant change in VEGF secretion per cell in rMC-1 only. At 0, 5.5, and 30mM glucose, MIO-M1 secreted about 5-7-fold higher level of VEGF (pg/cell) than rMC-1. The mechanism of glucose-induced changes in rMC-1 and MIO-M1 cell viability and VEGF secretion remains to be elucidated. PMID:27347496

  18. Normalization of blood glucose in diabetic rats with phlorizin treatment reverses insulin-resistant glucose transport in adipose cells without restoring glucose transporter gene expression.

    PubMed Central

    Kahn, B B; Shulman, G I; DeFronzo, R A; Cushman, S W; Rossetti, L

    1991-01-01

    Evidence is emerging for a direct role of glucose, independent of changes in insulin, in the regulation of cellular glucose transport and glucose utilization in vivo. In this study we investigate potential cellular and molecular mechanisms for this regulatory effect of glucose by determining how normalization of glycemia without insulin therapy in diabetic rats influences 3-O-methylglucose transport and the expression and translocation of two genetically distinct species of glucose transporters (GTs) in adipose cells. These results are compared with alterations in glucose disposal in vivo measured by euglycemic clamp. In rats rendered diabetic by 90% pancreatectomy, insulin-stimulated glucose transport in adipose cells is decreased 50% in parallel with reduced insulin-mediated glucose disposal in vivo. Levels of adipose/muscle GTs measured by immunoblotting are decreased in adipose cell subcellular membrane fractions, as are the corresponding mRNA levels assessed by Northern blotting of total adipose cell RNA. Normalization of blood glucose in diabetic rats with phlorizin, which impairs renal tubular glucose reabsorption and thus enhances glucose excretion, restores insulin-stimulated glucose transport in adipose cells and insulin-mediated glucose disposal in vivo. Importantly, levels of the adipose/muscle GT protein remain 43% reduced in the low-density microsomes in the basal state and 46% reduced in the plasma membranes in the insulin-stimulated state. Adipose/muscle GT mRNA levels remain approximately 50% depressed. Levels of the HepG2/brain GT protein and mRNA are unaltered by diabetes or phlorizin treatment. Thus, changes in ambient glucose independent of changes in ambient insulin can regulate the glucose transport response to insulin in isolated adipose cells and changes in responsiveness parallel alterations in glucose uptake in vivo. Since this effect can occur without alteration in the expression of the two species of glucose transporters present in

  19. Mitogen-stimulated and rapamycin-sensitive glucose transporter 12 targeting and functional glucose transport in renal epithelial cells.

    PubMed

    Wilson-O'Brien, Amy L; Dehaan, Carrie L; Rogers, Suzanne

    2008-03-01

    We hypothesized that glucose transporter 12 (GLUT12) is involved in regulation of glucose flux in distal renal tubules in response to elevated glucose. We used the Madin-Darby canine kidney polarized epithelial cell model and neutralizing antibodies to analyze GLUT12 targeting and directional GLUT12-mediated glucose transport. At physiological glucose concentrations, GLUT12 was localized to a perinuclear position. High glucose and serum treatment resulted in GLUT12 localization to the apical membrane. This mitogen-stimulated targeting of GLUT12 was inhibited by rapamycin, the specific inhibitor of mammalian target of rapamycin (mTOR). The functional role of GLUT12 was also examined. We constructed a GLUT12 cDNA containing a c-Myc epitope tag in the fifth exofacial loop. Assays of glucose transport at the apical membrane were performed using Transwell filters. By comparing transport assays in the presence of neutralizing anti-c-Myc monoclonal antibody, we specifically measured GLUT12-mediated glucose transport at the apical surface. GLUT12-mediated glucose transport was mitogen dependent and rapamycin sensitive. Our results implicate mTOR signaling in a novel pathway of glucose transporter protein targeting and glucose transport. Activity of the mTOR pathway has been associated with diabetic kidney disease. Our results provide evidence for a link between GLUT12 protein trafficking, glucose transport and signaling molecules central to the control of metabolic disease processes. PMID:18039784

  20. A role for glucose in hypothermic hamsters

    NASA Technical Reports Server (NTRS)

    Resch, G. E.; Musacchia, X. J.

    1976-01-01

    Hypothermic hamsters at a rectal temperature of 7 C showed a fivefold increase in survival times from 20 to 100.5 hr when infused with glucose which maintained a blood level at about 45 mg/100 ml. A potential role for osmotic effects of the infusion was tested and eliminated. There was no improvement in survival of 3-O-methylglucose or dextran 40-infused animals. The fact that death eventually occurs even in the glucose-infused animal after about 4 days and that oxygen consumption undergoes a slow decrement in that period suggests that hypothermic survival is not wholly substrate limited. Radioactive tracer showed that localization of the C-14 was greatest in brain tissue and diaphragm, intermediate in heart and kidney, and lowest in skeletal muscle and liver. The significance of the label at sites important to respiration and circulation was presented.

  1. Design and optimization of a selective subcutaneously implantable glucose electrode based on "wired" glucose oxidase.

    PubMed

    Csöregi, E; Schmidtke, D W; Heller, A

    1995-04-01

    An implantable 0.29 mm o.d. flexible wire electrode was designed for subcutaneous monitoring of glucose. The electrode was formed by sequentially depositing in a 0.09 mm deep shielded recess at the tip of a polyimide-insulated 0.25 mm gold wire a "wired" glucose oxidase (GOX) sensing layer, a mass transport limiting layer, and a nonfouling biocompatible layer. The glucose sensing layer was formed by cross-linking (poly[(1-vinylimidazolyl)osmium(4,4'-dimethylbipyridine)2Cl] )+/2+(PVI13-dme - Os) and GOX with poly(ethylene glycol) diglycidyl ether (PEG). The glucose mass transport restricting layer consisted of a poly(ester sulfonic acid) film (Eastman AQ 29D) and a copolymer of polyaziridine and poly(vinyl pyridine) partially quaternized with methylene carboxylate. The outer biocompatible layer was formed by photo-cross-linking tetraacrylated poly(ethylene oxide). The three layers contained no leachable components and had a total mass less than 2.2 micrograms (approximately 50 ng of Os). When poised at +200 mV vs SCE and operated at 37 degrees C, the 5 x 10(-4) cm2 electrode had in vitro a sensitivity of 1-2.5 nA mM-1. The current increased with the glucose concentration up to 60 mM, and the 10-90% response time was approximately 1 min when the glucose concentration was abruptly raised from 5 to 10 mM. The sensitivity decreased by less than 4% over a test period of 1 week, during which the electrode was operated continuously in a 10 mM glucose physiological buffer solution at 37 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7733469

  2. Evaluation of MOSFET-type glucose sensor using platinum electrode with glucose oxidase

    NASA Astrophysics Data System (ADS)

    Ooe, Katsutoshi; Hamamoto, Yasutaro; Hirano, Yoshiaki

    2005-02-01

    As the population ages, health management will be one of the important issues. The development of a safe medical machine based on MEMS technologies for the human body will be the primary research project in the future. We have developed the glucose sensor, as one of the medical based devices, for use in the Health Monitoring System (HMS). HMS is the device that continuously monitors human health conditions. For example, blood is the monitoring target of HMS. The glucose sensor specifically detects the glucose levels of the blood and monitors the glucose concentration as the blood sugar level. This glucose sensor has a "separated Au electrode", which immobilizes GOx. In our previous work, GOx was immobilized onto Au electrode by the SAMs (Self-Assembled Monolayer) method, and the sensor, using this working electrode, detected the glucose concentration of an aqueous glucose solution. In this report, we used a Pt electrode, which immobilized GOx, as a working electrode. Au electrode, which was used previously, was dissolved by the application of current in the presence of chloride ions. Based on the above-mentioned fact, a new working electrode, which immobilized GOx, was produced using Pt, which did not possess such characteristics. These Pt working electrodes were produced using the covalent binding method and the cross-link method, and both the electrodes displayed a good sensing property. In addition, the electrode using glutaraldehyde (GA) and bovine serum albumin (BSA) as crosslinking agents was produced, and it displayed better characteristics as compared with those displayed by the electrode that used only GA. Based on the above-mentioned techniques, the improvement in performance of the sensor was confirmed.

  3. Metabolism of tritiated D-glucose in rat erythrocytes

    SciTech Connect

    Manuel y Keenoy, B.; Malaisse-Lagae, F.; Malaisse, W.J. )

    1991-09-01

    The metabolism of D-(U-14C)glucose, D-(1-14C)glucose, D-(6-14C)glucose, D-(1-3H)glucose, D-(2-3H)glucose, D-(3-3H)glucose, D-(3,4-3H)glucose, D-(5-3H)glucose, and D-(6-3H)glucose was examined in rat erythrocytes. There was a fair agreement between the rate of 3HOH production from either D-(3-3H)glucose and D-(5-3H)glucose, the decrease in the 2,3-diphosphoglycerate pool, its fractional turnover rate, the production of 14C-labeled lactate from D-(U-14C)glucose, and the total lactate output. The generation of both 3HOH and tritiated acidic metabolites from D-(3,4-3H)glucose indicated incomplete detritiation of the C4 during interconversion of fructose-1,6-bisphosphate and triose phosphates. Erythrocytes unexpectedly generated 3HOH from D-(6-3H)glucose, a phenomenon possibly attributable to the detritiation of (3-3H)pyruvate in the reaction catalyzed by glutamate pyruvate transaminase. The production of 3HOH from D-(2-3H)glucose was lower than that from D-(5-3H)glucose, suggesting enzyme-to-enzyme tunneling of glycolytic intermediates in the hexokinase/phosphoglucoisomerase/phosphofructokinase sequence. The production of 3HOH from D-(1-3H)glucose largely exceeded that of 14CO2 from D-(1-14C)glucose, a situation tentatively ascribed to the generation of 3HOH in the phosphomannoisomerase reaction. It is further speculated that the adjustment in specific radioactivity of D-(1-3H)glucose-6-phosphate cannot simultaneously match the vastly different degrees of isotopic discrimination in velocity at the levels of the reactions catalyzed by either glucose-6-phosphate dehydrogenase or phosphoglucoisomerase. The interpretation of the present findings thus raises a number of questions, which are proposed as a scope for further investigations.

  4. Enzymes of glucose metabolism in Frankia sp.

    PubMed

    Lopez, M F; Torrey, J G

    1985-04-01

    Enzymes of glucose metabolism were assayed in crude cell extracts of Frankia strains HFPArI3 and HFPCcI2 as well as in isolated vesicle clusters from Alnus rubra root nodules. Activities of the Embden-Meyerhof-Parnas pathway enzymes glucokinase, phosphofructokinase, and pyruvate kinase were found in Frankia strain HFPArI3 and glucokinase and pyruvate kinase were found in Frankia strain HFPCcI2 and in the vesicle clusters. An NADP+-linked glucose 6-phosphate dehydrogenase and an NAD-linked 6-phosphogluconate dehydrogenase were found in all of the extracts, although the role of these enzymes is unclear. No NADP+-linked 6-phosphogluconate dehydrogenase was found. Both dehydrogenases were inhibited by adenosine 5-triphosphate, and the apparent Km's for glucose 6-phosphate and 6-phosphogluconate were 6.86 X 10(-4) and 7.0 X 10(-5) M, respectively. In addition to the enzymes mentioned above, an NADP+-linked malic enzyme was detected in the pure cultures but not in the vesicle clusters. In contrast, however, the vesicle clusters had activity of an NAD-linked malic enzyme. The possibility that this enzyme resulted from contamination from plant mitochondria trapped in the vesicle clusters could not be discounted. None of the extracts showed activities of the Entner-Doudoroff enzymes or the gluconate metabolism enzymes gluconate dehydrogenase or gluconokinase. Propionate- versus trehalose-grown cultures of strain HFPArI3 showed similar activities of most enzymes except malic enzyme, which was higher in the cultures grown on the organic acid. Nitrogen-fixing cultures of strain HFPArI3 showed higher specific activities of glucose 6-phosphate and 6-phosphogluconate dehydrogenases and phosphofructokinase than ammonia-grown cultures. PMID:3980434

  5. A glucose biofuel cell implanted in rats.

    PubMed

    Cinquin, Philippe; Gondran, Chantal; Giroud, Fabien; Mazabrard, Simon; Pellissier, Aymeric; Boucher, François; Alcaraz, Jean-Pierre; Gorgy, Karine; Lenouvel, François; Mathé, Stéphane; Porcu, Paolo; Cosnier, Serge

    2010-01-01

    Powering future generations of implanted medical devices will require cumbersome transcutaneous energy transfer or harvesting energy from the human body. No functional solution that harvests power from the body is currently available, despite attempts to use the Seebeck thermoelectric effect, vibrations or body movements. Glucose fuel cells appear more promising, since they produce electrical energy from glucose and dioxygen, two substrates present in physiological fluids. The most powerful ones, Glucose BioFuel Cells (GBFCs), are based on enzymes electrically wired by redox mediators. However, GBFCs cannot be implanted in animals, mainly because the enzymes they rely on either require low pH or are inhibited by chloride or urate anions, present in the Extra Cellular Fluid (ECF). Here we present the first functional implantable GBFC, working in the retroperitoneal space of freely moving rats. The breakthrough relies on the design of a new family of GBFCs, characterized by an innovative and simple mechanical confinement of various enzymes and redox mediators: enzymes are no longer covalently bound to the surface of the electron collectors, which enables use of a wide variety of enzymes and redox mediators, augments the quantity of active enzymes, and simplifies GBFC construction. Our most efficient GBFC was based on composite graphite discs containing glucose oxidase and ubiquinone at the anode, polyphenol oxidase (PPO) and quinone at the cathode. PPO reduces dioxygen into water, at pH 7 and in the presence of chloride ions and urates at physiological concentrations. This GBFC, with electrodes of 0.133 mL, produced a peak specific power of 24.4 microW mL(-1), which is better than pacemakers' requirements and paves the way for the development of a new generation of implantable artificial organs, covering a wide range of medical applications. PMID:20454563

  6. Nonnutritive sweeteners, energy balance and glucose homeostasis

    PubMed Central

    Pepino, M. Yanina; Bourne, Christina

    2012-01-01

    Purpose of review To review recent work on potential mechanisms underlying a paradoxical positive association between the consumption of nonnutritive sweeteners (NNS) and weight gain. Recent findings Several potential mechanism, not mutually exclusive, are hypothesized. First, by dissociating sweetness from calories, NNS could interfere with physiological responses that control homeostasis. Second, by changing the intestinal environment, NNS could affect the microbiota and in turn trigger inflammatory processes that are associated with metabolic disorders. Third, by interacting with novel sweet-taste receptors discovered in the gut, NNS could affect glucose absorptive capacity and glucose homeostasis. This last is the mechanism that has received the most attention recently. Some animal studies, but not all, found that NNS activate gut sweet taste-pathways that control incretin release and up-regulate glucose transporters. Human studies found that, at least for healthy fasted subjects, the sole interaction of NNS with sweet-taste gut receptors is insufficient to elicit incretin responses. The reasons for discrepancy between different studies is unknown but could be related to the species of mammal tested and the dose of NNS used. Summary Whether NNS are metabolically inactive, as previously assumed, is unclear. Further research on the potential effects of NNS on human metabolism is warranted. PMID:21505330

  7. The appropriation of glucose through primate neurodevelopment.

    PubMed

    Bauernfeind, Amy L; Babbitt, Courtney C

    2014-12-01

    The human brain is considerably larger and more energetically costly than that of other primate species. As such, discovering how human ancestors were able to provide sufficient energy to their brains is a central theme in the study of hominin evolution. However, many discussions of metabolism frequently omit the different ways in which energy, primarily glucose, is used once made available to the brain. In this review, we discuss two glucose metabolic pathways, oxidative phosphorylation and aerobic glycolysis, and their respective contributions to the energetic and anabolic budgets of the brain. While oxidative phosphorylation is a more efficient producer of energy, aerobic glycolysis contributes essential molecules for the growth of the brain and maintaining the structure of its cells. Although both pathways occur in the brain throughout the lifetime, aerobic glycolysis is a critical pathway during development, and oxidative phosphorylation is highest during adulthood. We outline how elevated levels of aerobic glycolysis may support the protracted neurodevelopmental sequence of humans compared with other primates. Finally, we review the genetic evidence for differences in metabolic function in the brains of primates and explore genes that may provide insight into how glucose metabolism may differ across species. PMID:25110208

  8. Comparison of Salivary and Serum Glucose Levels in Diabetic Patients

    PubMed Central

    Sandhu, Simarpreet Virk; Bansal, Himanta; Sharma, Deepti

    2014-01-01

    Background: Diabetes mellitus is a noncommunicable disease with a rising prevalence worldwide and in developing countries. The most commonly used diagnostic biofluid for detection of glucose levels is blood, but sample collection is an invasive and painful procedure. Thus, there arises a need for a noninvasive and painless technique to detect glucose levels. Aims and Objectives: The objectives of the present study were to estimate the glucose levels of saliva, to assess if any significant correlation existed between the serum and salivary glucose levels, and to correlate salivary glucose levels with regard to duration of diabetes, age, and gender. In the present study, serum and salivary glucose levels of 200 subjects (100 diabetic subjects and 100 nondiabetic subjects) were estimated by glucose oxidase method. Glycosylated hemoglobin levels were also measured in randomly selected 40 diabetic subjects. Results: The findings of present study revealed a significant correlation between salivary and serum glucose levels in both diabetic and nondiabetic subjects. No significant relationship was observed between salivary glucose levels and gender or age in both diabetics and nondiabetics and between salivary glucose levels and duration of diabetes in diabetics. Conclusion: On the basis of the findings, it was concluded that salivary glucose levels could serve as a potentially noninvasive adjunct to monitor glycemic control in diabetic patients. PMID:25294888

  9. Glucose enhances indolic glucosinolate biosynthesis without reducing primary sulfur assimilation

    PubMed Central

    Miao, Huiying; Cai, Congxi; Wei, Jia; Huang, Jirong; Chang, Jiaqi; Qian, Hongmei; Zhang, Xin; Zhao, Yanting; Sun, Bo; Wang, Bingliang; Wang, Qiaomei

    2016-01-01

    The effect of glucose as a signaling molecule on induction of aliphatic glucosinolate biosynthesis was reported in our former study. Here, we further investigated the regulatory mechanism of indolic glucosinolate biosynthesis by glucose in Arabidopsis. Glucose exerted a positive influence on indolic glucosinolate biosynthesis, which was demonstrated by induced accumulation of indolic glucosinolates and enhanced expression of related genes upon glucose treatment. Genetic analysis revealed that MYB34 and MYB51 were crucial in maintaining the basal indolic glucosinolate accumulation, with MYB34 being pivotal in response to glucose signaling. The increased accumulation of indolic glucosinolates and mRNA levels of MYB34, MYB51, and MYB122 caused by glucose were inhibited in the gin2-1 mutant, suggesting an important role of HXK1 in glucose-mediated induction of indolic glucosinolate biosynthesis. In contrast to what was known on the function of ABI5 in glucose-mediated aliphatic glucosinolate biosynthesis, ABI5 was not required for glucose-induced indolic glucosinolate accumulation. In addition, our results also indicated that glucose-induced glucosinolate accumulation was due to enhanced sulfur assimilation instead of directed sulfur partitioning into glucosinolate biosynthesis. Thus, our data provide new insights into molecular mechanisms underlying glucose-regulated glucosinolate biosynthesis. PMID:27549907

  10. Glucose enhances indolic glucosinolate biosynthesis without reducing primary sulfur assimilation.

    PubMed

    Miao, Huiying; Cai, Congxi; Wei, Jia; Huang, Jirong; Chang, Jiaqi; Qian, Hongmei; Zhang, Xin; Zhao, Yanting; Sun, Bo; Wang, Bingliang; Wang, Qiaomei

    2016-01-01

    The effect of glucose as a signaling molecule on induction of aliphatic glucosinolate biosynthesis was reported in our former study. Here, we further investigated the regulatory mechanism of indolic glucosinolate biosynthesis by glucose in Arabidopsis. Glucose exerted a positive influence on indolic glucosinolate biosynthesis, which was demonstrated by induced accumulation of indolic glucosinolates and enhanced expression of related genes upon glucose treatment. Genetic analysis revealed that MYB34 and MYB51 were crucial in maintaining the basal indolic glucosinolate accumulation, with MYB34 being pivotal in response to glucose signaling. The increased accumulation of indolic glucosinolates and mRNA levels of MYB34, MYB51, and MYB122 caused by glucose were inhibited in the gin2-1 mutant, suggesting an important role of HXK1 in glucose-mediated induction of indolic glucosinolate biosynthesis. In contrast to what was known on the function of ABI5 in glucose-mediated aliphatic glucosinolate biosynthesis, ABI5 was not required for glucose-induced indolic glucosinolate accumulation. In addition, our results also indicated that glucose-induced glucosinolate accumulation was due to enhanced sulfur assimilation instead of directed sulfur partitioning into glucosinolate biosynthesis. Thus, our data provide new insights into molecular mechanisms underlying glucose-regulated glucosinolate biosynthesis. PMID:27549907

  11. Glucose metabolism and hexosamine pathway regulate oncogene-induced senescence.

    PubMed

    Gitenay, D; Wiel, C; Lallet-Daher, H; Vindrieux, D; Aubert, S; Payen, L; Simonnet, H; Bernard, D

    2014-01-01

    Oncogenic stress-induced senescence (OIS) prevents the ability of oncogenic signals to induce tumorigenesis. It is now largely admitted that the mitogenic effect of oncogenes requires metabolic adaptations to respond to new energetic and bio constituent needs. Yet, whether glucose metabolism affects OIS response is largely unknown. This is largely because of the fact that most of the OIS cellular models are cultivated in glucose excess. In this study, we used human epithelial cells, cultivated without glucose excess, to study alteration and functional role of glucose metabolism during OIS. We report a slowdown of glucose uptake and metabolism during OIS. Increasing glucose metabolism by expressing hexokinase2 (HK2), which converts glucose to glucose-6-phosphate (G6P), favors escape from OIS. Inversely, expressing a glucose-6-phosphatase, [corrected] pharmacological inhibition of HK2, or adding nonmetabolizable glucose induced a premature senescence. Manipulations of various metabolites covering G6P downstream pathways (hexosamine, glycolysis, and pentose phosphate pathways) suggest an unexpected role of the hexosamine pathway in controlling OIS. Altogether, our results show that decreased glucose metabolism occurs during and participates to OIS. PMID:24577087

  12. Blood Sugar Measurement in Zebrafish Reveals Dynamics of Glucose Homeostasis

    PubMed Central

    Eames, Stefani C.; Philipson, Louis H.; Prince, Victoria E.

    2010-01-01

    Abstract The adult zebrafish has the potential to become an important model for diabetes-related research. To realize this potential, small-scale methods for analyzing pancreas function are required. The measurement of blood glucose level is a commonly used method for assessing β-cell function, but the small size of the zebrafish presents challenges both for collecting blood samples and for measuring glucose. We have developed methods for collecting microsamples of whole blood and plasma for the measurement of hematocrit and blood glucose. We demonstrate that two hand-held glucose meters designed for use by human diabetics return valid results with zebrafish blood. Additionally, we present methods for fasting and for performing postprandial glucose and intraperitoneal glucose tolerance tests. We find that the dynamics of zebrafish blood glucose homeostasis are consistent with patterns reported for other omnivorous teleost fish. PMID:20515318

  13. Glucose Biosensors Based on Carbon Nanotube Nanoelectrode Ensembles

    SciTech Connect

    Lin, Yuehe ); Lu, Fang; Tu, Yi; Ren, Zhifeng

    2004-02-12

    This paper describes the development of glucose biosensors based on carbon nanotube (CNT) nanoelectrode ensembles (NEEs) for the selective detection of glucose. Glucose oxidase was covalently immobilized on CNT NEEs via carbodiimide chemistry by forming amide linkages between their amine residues and carboxylic acid groups on the CNT tips. The catalytic reduction of hydrogen peroxide liberated from the enzymatic reaction of glucose oxidase upon the glucose and oxygen on CNT NEEs leads to the selective detection of glucose. The biosensor effectively performs selective electrochemical analysis of glucose in the presence of common interferents (e.g. acetaminophen, uric and ascorbic acids), avoiding the generation of an overlapping signal from such interferents. Such an operation eliminates the need for permselective membrane barriers or artificial electron mediators, thus greatly simplifying the sensor design and fabrication.

  14. Fluorescence Intensity- and Lifetime-Based Glucose Sensing Using Glucose/Galactose-Binding Protein

    PubMed Central

    Pickup, John C.; Khan, Faaizah; Zhi, Zheng-Liang; Coulter, Jonathan; Birch, David J. S.

    2013-01-01

    We review progress in our laboratories toward developing in vivo glucose sensors for diabetes that are based on fluorescence labeling of glucose/galactose-binding protein. Measurement strategies have included both monitoring glucose-induced changes in fluorescence resonance energy transfer and labeling with the environmentally sensitive fluorophore, badan. Measuring fluorescence lifetime rather than intensity has particular potential advantages for in vivo sensing. A prototype fiber-optic-based glucose sensor using this technology is being tested.Fluorescence technique is one of the major solutions for achieving the continuous and noninvasive glucose sensor for diabetes. In this article, a highly sensitive nanostructured sensor is developed to detect extremely small amounts of aqueous glucose by applying fluorescence energy transfer (FRET). A one-pot method is applied to produce the dextran-fluorescein isothiocyanate (FITC)-conjugating mesoporous silica nanoparticles (MSNs), which afterward interact with the tetramethylrhodamine isothiocyanate (TRITC)-labeled concanavalin A (Con A) to form the FRET nanoparticles (FITC-dextran-Con A-TRITC@MSNs). The nanostructured glucose sensor is then formed via the self-assembly of the FRET nanoparticles on a transparent, flexible, and biocompatible substrate, e.g., poly(dimethylsiloxane). Our results indicate the diameter of the MSNs is 60 ± 5 nm. The difference in the images before and after adding 20 μl of glucose (0.10 mmol/liter) on the FRET sensor can be detected in less than 2 min by the laser confocal laser scanning microscope. The correlation between the ratio of fluorescence intensity, I(donor)/I(acceptor), of the FRET sensor and the concentration of aqueous glucose in the range of 0.04–4 mmol/liter has been investigated; a linear relationship is found. Furthermore, the durability of the nanostructured FRET sensor is evaluated for 5 days. In addition, the recorded images can be converted to digital images by

  15. Interference Reduction in Glucose Detection by Redox Potential Tuning: New Glucose Meter Development.

    PubMed

    Cho, Seong Je; Cho, Chul-Ho; Kim, Kwang Bok; Lee, Min-Hyoung; Kim, Jae Hong; Lee, Suho; Cho, Jaegeol; Jung, Suntae; Kim, Dong-Min; Shim, Yoon-Bo

    2015-01-01

    A new glucose meter was developed employing a novel disposable glucose sensor strip comprising a nicotinamide adenine dinucleotide-glucose dehydrogenase (NAD-GDH) and a mixture of Fe compounds as a mediator. An iron complex, 5-(2,5-di(thiophen-2-yl)-1H-pyrrol-1-yl)-1,10-phenanthroline iron(III) chloride (Fe-PhenTPy), was synthesized as a new mediator for the NAD-GDH system. Due to the high oxidation potential of the mediator, the detection potential was tuned to be more closely fitted toward the enzyme reaction potential, less than 400 mV (vs. Ag/AgCl), by mixing with an additional iron mediator. The impedance spectrometry for the enzyme sensor containing the mixed mediators showed an enhanced charge transfer property. In addition, a new cartridge-type glucose meter was manufactured using effective aligned-electrodes, which showed an enhanced response compared with conventional electrode alignment. The proposed glucose sensor resulted in a wide dynamic range in the concentration range of 30 - 500 mg dL(-1) with a reduced interference effect and a good sensitivity of 0.57 μA mM(-1). PMID:26165295

  16. Glucose biosensor based on nanohybrid material of gold nanoparticles and glucose oxidase on a bioplatform.

    PubMed

    Zhang, Yan; Jia, Wenjuan; Cui, Miao; Dong, Chuan; Shuang, Shaomin; Kwan, Yuen; Choi, Martin M F

    2011-05-01

    A simple and relatively cheap glucose biosensor based on a combination of gold nanoparticles (Au NPs) and glucose oxidase (GO(x) ) immobilized on a bioplatform eggshell membrane was established. Scanning electron microscopy showed successful immobilization of Au NPs/GO(x) on the eggshell membrane. The effects of pH, phosphate buffer concentration, and temperature on the glucose biosensor were studied in detail. The biosensor shows a linear response at a glucose concentration range of 5-525 μM. The detection limit of the biosensor is 2.5 μM (S/N = 3). The biosensor exhibits good repeatability with RSD = 3.6% (n = 6), good operational stability with over 300 measurements and long-term storage stability with a shelf life of at least 6 months. The response time is less than 60 s. The glucose level in commercial food samples has been successfully determined. The proposed work shows potential to develop cost-effective biosensors for biotechnological, biomedical and industrial use. PMID:21381208

  17. Amperometric glucose biosensor utilizing FAD-dependent glucose dehydrogenase immobilized on nanocomposite electrode.

    PubMed

    Monošík, Rastislav; Streďanský, Miroslav; Lušpai, Karol; Magdolen, Peter; Šturdík, Ernest

    2012-04-01

    Amperometric glucose biosensors utilizing commercially available FAD-dependent glucose dehydrogenases from two strains of Aspergillus species are described. Enzymes were immobilized on nanocomposite electrode consisting of multi-walled carbon nanotubes by entrapment between chitosan layers. Unlike the common glucose oxidase based biosensor, the presented biosensors appeared to be O(2)-independent. The optimal amount of enzymes, working potential and pH value of working media of the glucose biosensors were determined. The biosensor utilizing enzyme isolated from Aspergillus sp. showed linearity over the range from 50 to 960 μM and from 70 to 620 μM for enzyme from Aspergillus oryzae. The detection limits were 4.45 μM and 4.15 μM, respectively. The time of response was found to be 60 s. The biosensors showed excellent operational stability - no loss of sensitivity after 100 consecutive measurements and after the storage for 4 weeks at 4 °C in phosphate buffer solution. When biosensors were held in a dessicator at room temperature without use, they kept the same response ability at least after 6 months. Finally, the results obtained from measurements of beverages and wine samples were compared with those obtained with the enzymatic-spectrophotometric and standard HPLC methods, respectively. Good correlation between results in case of analysis of real samples and good analytical performance of presented glucose biosensor allows to use presented concept for mass production and commercial use. PMID:22418262

  18. Development of an Amperometric-Based Glucose Biosensor to Measure the Glucose Content of Fruit

    PubMed Central

    Ang, Lee Fung; Por, Lip Yee; Yam, Mun Fei

    2015-01-01

    An amperometric enzyme-electrode was introduced where glucose oxidase (GOD) was immobilized on chitosan membrane via crosslinking, and then fastened on a platinum working electrode. The immobilized enzyme showed relatively high retention activity. The activity of the immobilized enzyme was influenced by its loading, being suppressed when more than 0.6 mg enzyme was used in the immobilization. The biosensor showing the highest response to glucose utilized 0.21 ml/cm2 thick chitosan membrane. The optimum experimental conditions for the biosensors in analysing glucose dissolved in 0.1 M phosphate buffer (pH 6.0) were found to be 35°C and 0.6 V applied potential. The introduced biosensor reached a steady-state current at 60 s. The apparent Michaelis-Menten constant (KMapp) of the biosensor was 14.2350 mM, and its detection limit was 0.05 mM at s/n > 3, determined experimentally. The RSD of repeatability and reproducibility of the biosensor were 2.30% and 3.70%, respectively. The biosensor was showed good stability; it retained ~36% of initial activity after two months of investigation. The performance of the biosensors was evaluated by determining the glucose content in fruit homogenates. Their accuracy was compared to that of a commercial glucose assay kit. There was no significance different between two methods, indicating the introduced biosensor is reliable. PMID:25789757

  19. Development of an amperometric-based glucose biosensor to measure the glucose content of fruit.

    PubMed

    Ang, Lee Fung; Por, Lip Yee; Yam, Mun Fei

    2015-01-01

    An amperometric enzyme-electrode was introduced where glucose oxidase (GOD) was immobilized on chitosan membrane via crosslinking, and then fastened on a platinum working electrode. The immobilized enzyme showed relatively high retention activity. The activity of the immobilized enzyme was influenced by its loading, being suppressed when more than 0.6 mg enzyme was used in the immobilization. The biosensor showing the highest response to glucose utilized 0.21 ml/cm2 thick chitosan membrane. The optimum experimental conditions for the biosensors in analysing glucose dissolved in 0.1 M phosphate buffer (pH 6.0) were found to be 35°C and 0.6 V applied potential. The introduced biosensor reached a steady-state current at 60 s. The apparent Michaelis-Menten constant ([Formula: see text]) of the biosensor was 14.2350 mM, and its detection limit was 0.05 mM at s/n > 3, determined experimentally. The RSD of repeatability and reproducibility of the biosensor were 2.30% and 3.70%, respectively. The biosensor was showed good stability; it retained ~36% of initial activity after two months of investigation. The performance of the biosensors was evaluated by determining the glucose content in fruit homogenates. Their accuracy was compared to that of a commercial glucose assay kit. There was no significance different between two methods, indicating the introduced biosensor is reliable. PMID:25789757

  20. Improvement in glucose biosensing response of electrochemically grown polypyrrole nanotubes by incorporating crosslinked glucose oxidase.

    PubMed

    Palod, Pragya Agar; Singh, Vipul

    2015-10-01

    In this paper a novel enzymatic glucose biosensor has been reported in which platinum coated alumina membranes (Anodisc™s) have been employed as templates for the growth of polypyrrole (PPy) nanotube arrays using electrochemical polymerization. The PPy nanotube arrays were grown on Anodisc™s of pore diameter 100 nm using potentiostatic electropolymerization. In order to optimize the polymerization time, immobilization of glucose oxidase (GOx) was first performed using physical adsorption followed by measuring its biosensing response which was examined amperometrically for increasing concentrations of glucose. In order to further improve the sensing performance of the biosensor fabricated for optimum polymerization duration, enzyme immobilization was carried out using cross-linking with glutaraldehyde and bovine serum albumin (BSA). Approximately six fold enhancement in the sensitivity was observed in the fabricated electrodes. The biosensors also showed a wide range of linear operation (0.2-13 mM), limit of detection of 50 μM glucose concentration, excellent selectivity for glucose, notable reliability for real sample detection and substantially improved shelf life. PMID:26117773

  1. A glucose biosensor based on glucose oxidase immobilized on three-dimensional porous carbon electrodes.

    PubMed

    Chen, Jingyi; Zhu, Rong; Huang, Jia; Zhang, Man; Liu, Hongyu; Sun, Min; Wang, Li; Song, Yonghai

    2015-08-21

    A novel glucose biosensor was developed by immobilizing glucose oxidase (GOD) on a three-dimensional (3D) porous kenaf stem-derived carbon (3D-KSC) which was firstly proposed as a novel supporting material to load biomolecules for electrochemical biosensing. Here, an integrated 3D-KSC electrode was prepared by using a whole piece of 3D-KSC to load the GOD molecules for glucose biosensing. The morphologies of integrated 3D-KSC and 3D-KSC/GOD electrodes were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The SEM results revealed a 3D honeycomb macroporous structure of the integrated 3D-KSC electrode. The TEM results showed some microporosities and defects in the 3D-KSC electrode. The electrochemical behaviors and electrocatalytic performance of the integrated 3D-KSC/GOD electrode were evaluated by cyclic voltammetry and electrochemical impedance spectroscopy. The effects of pH and scan rates on the electrochemical response of the biosensor have been studied in detail. The glucose biosensor showed a wide linear range from 0.1 mM to 14.0 mM with a high sensitivity of 1.73 μA mM(-1) and a low detection limit of 50.75 μM. Furthermore, the glucose biosensor exhibited high selectivity, good repeatability and reproducibility, and good stability. PMID:26114193

  2. Sodium-Glucose Cotransporter 2 Inhibitors: Possible Anti-Atherosclerotic Effects Beyond Glucose Lowering.

    PubMed

    Yanai, Hidekatsu; Katsuyama, Hisayuki; Hamasaki, Hidetaka; Adachi, Hiroki; Moriyama, Sumie; Yoshikawa, Reo; Sako, Akahito

    2016-01-01

    The new drug for type 2 diabetes, the sodium-glucose cotransporter 2 (SGLT-2) inhibitor, is reversible inhibitor of SGLT-2, leading to reduction of renal glucose reabsorption and decrease of plasma glucose, in an insulin-independent manner. In addition to glucose control, the management of coronary risk factors is very important for patients with diabetes. Here we reviewed published articles about the possible anti-atherosclerotic effects beyond glucose lowering of the SGLT-2 inhibitors. We searched by using Pubmed, and found 770 published articles about SGLT-2 inhibitors. Among 10 kinds of SGLT-2 inhibitors, the number of published articles about dapagliflozin was the greatest among SGLT-2 inhibitors. Since SGLT-2 inhibitors have similar chemical structures, we concentrated on the published articles about dapagliflozin. SGLT-2 inhibitors are proved to be significantly associated with weight loss and reduction of blood pressure by a relatively large number of studies. The studies investigating effects of dapagliflozin on visceral fat, insulin sensitivity, serum lipids, inflammation and adipocytokines are very limited. An influence of increase in glucagon secretion by SGLT-2 inhibitors on metabolic risk factors remains unknown. PMID:26668677

  3. Effect of endurance training on glucose transport capacity and glucose transporter expression in rat skeletal muscle

    SciTech Connect

    Ploug, T.; Stallknecht, B.M.; Pedersen, O.; Kahn, B.B.; Ohkuwa, T.; Vinten, J.; Galbo, H. )

    1990-12-01

    The effect of 10 wk endurance swim training on 3-O-methylglucose (3-MG) uptake (at 40 mM 3-MG) in skeletal muscle was studied in the perfused rat hindquarter. Training resulted in an increase of approximately 33% for maximum insulin-stimulated 3-MG transport in fast-twitch red fibers and an increase of approximately 33% for contraction-stimulated transport in slow-twitch red fibers compared with nonexercised sedentary muscle. A fully additive effect of insulin and contractions was observed both in trained and untrained muscle. Compared with transport in control rats subjected to an almost exhaustive single exercise session the day before experiment both maximum insulin- and contraction-stimulated transport rates were increased in all muscle types in trained rats. Accordingly, the increased glucose transport capacity in trained muscle was not due to a residual effect of the last training session. Half-times for reversal of contraction-induced glucose transport were similar in trained and untrained muscles. The concentrations of mRNA for GLUT-1 (the erythrocyte-brain-Hep G2 glucose transporter) and GLUT-4 (the adipocyte-muscle glucose transporter) were increased approximately twofold by training in fast-twitch red muscle fibers. In parallel to this, Western blot demonstrated a approximately 47% increase in GLUT-1 protein and a approximately 31% increase in GLUT-4 protein. This indicates that the increases in maximum velocity for 3-MG transport in trained muscle is due to an increased number of glucose transporters.

  4. Amperometric Glucose Biosensor Based on Self-Assembling Glucose Oxidase on Carbon Nanotubes

    SciTech Connect

    Liu, Guodong; Lin, Yuehe

    2006-01-01

    A flow injection amperometric glucose biosensor based on electrostatic self-assembling glucose oxidase (GOx) on a carbon nanotube (CNT)-modified glassy carbon transducer is described. GOx is immobilized on the negatively charged CNT surface by alternatively assembling a cationic polydiallyldimethylammonium chloride (PDDA) layer and a GOx layer. The unique sandwich-like layer structure (PDDA/GOx/PDDA/CNT) formed by self-assembling provides a favorable microenvironment to keep the bioactivity of GOx and to prevent enzyme molecule leakage. The direct electrochemistry behavior of GOx and electrocatalysis of H2O2 on the fabricated PDDA/GOx/PDDA/CNT electrode demonstrated that such a biosensor fabrication method preserves the activity of enzyme molecules and the mechanical and electrocatalytic properties of carbon nanotubes, enabling sensitive determination of glucose. Flow injection amperometric detection of glucose is carried out at -100 mV (vs Ag/AgCl) in 0.05 M phosphate buffer solution (pH 7.4) with wide linear response range of 15 uM- 6 mM and a detection limit of 7 uM. The PDDA/GOx/PDDA/CNT/GC biosensor showed excellent properties for the sensitive determination of glucose with good reproducibility, remarkable stability, and free of interference from other co-existing electroactive species. The present methods can be applied to assemble other enzyme molecules and biological molecules, such as antibody, antigen, and DNA, to the CNT surface for wide biosensor and bioassay applications.

  5. Testing the Glucose Hypothesis among Capuchin Monkeys: Does Glucose Boost Self-Control?

    PubMed

    Parrish, Audrey E; Emerson, Ishara D; Rossettie, Mattea S; Beran, Michael J

    2016-01-01

    The ego-depletion hypothesis states that self-control diminishes over time and with exertion. Accordingly, the glucose hypothesis attributes this depletion of self-control resources to decreases in blood glucose levels. Research has led to mixed findings among humans and nonhuman animals, with limited evidence for such a link between glucose and self-control among closely-related nonhuman primate species, but some evidence from more distantly related species (e.g., honeybees and dogs). We tested this hypothesis in capuchin monkeys by manipulating the sugar content of a calorie-matched breakfast meal following a nocturnal fast, and then presenting each monkey with the accumulation self-control task. Monkeys were presented with food items one-by-one until the subject retrieved and ate the accumulating items, which required continual inhibition of food retrieval in the face of an increasingly desirable reward. Results indicated no relationship between self-control performance on the accumulation task and glucose ingestion levels following a fast. These results do not provide support for the glucose hypothesis of self-control among capuchin monkeys within the presented paradigm. Further research assessing self-control and its physiological correlates among closely- and distantly-related species is warranted to shed light on the mechanisms underlying self-control behavior. PMID:27527225

  6. Carbon nanotube composites for glucose biosensor incorporated with reverse iontophoresis function for noninvasive glucose monitoring.

    PubMed

    Sun, Tai-Ping; Shieh, Hsiu-Li; Ching, Congo Tak-Shing; Yao, Yan-Dong; Huang, Su-Hua; Liu, Chia-Ming; Liu, Wei-Hao; Chen, Chung-Yuan

    2010-01-01

    This study aims to develop an amperometric glucose biosensor, based on carbon nanotubes material for reverse iontophoresis, fabricated by immobilizing a mixture of glucose oxidase (GOD) and multiwalled carbon nanotubes (MWCNT) epoxy-composite, on a planar screen-printed carbon electrode. MWCNT was employed to ensure proper incorporation into the epoxy mixture and faster electron transfer between the GOD and the transducer. Results showed this biosensor possesses a low detection potential (+500 mV), good sensitivity (4 microA/mM) and an excellent linear response range (r(2) = 0.999; 0-4 mM) of glucose detection at +500 mV (versus Ag/AgCl). The response time of the biosensor was about 25 s. In addition, the biosensor could be used in conjunction with reverse iontophoresis technique. In an actual evaluation model, an excellent linear relationship (r(2) = 0.986) was found between the glucose concentration of the actual model and the biosensor's current response. Thus, a glucose biosensor based on carbon nanotube composites and incorporated with reverse iontophoresis function was developed. PMID:20517479

  7. Molecular and industrial aspects of glucose isomerase.

    PubMed Central

    Bhosale, S H; Rao, M B; Deshpande, V V

    1996-01-01

    Glucose isomerase (GI) (D-xylose ketol-isomerase; EC. 5.3.1.5) catalyzes the reversible isomerization of D-glucose and D-xylose to D-fructose and D-xylulose, respectively. The enzyme has the largest market in the food industry because of its application in the production of high-fructose corn syrup (HFCS). HFCS, an equilibrium mixture of glucose and fructose, is 1.3 times sweeter than sucrose and serves as a sweetener for use by diabetics. Interconversion of xylose to xylulose by GI serves a nutritional requirement in saprophytic bacteria and has a potential application in the bioconversion of hemicellulose to ethanol. The enzyme is widely distributed in prokaryotes. Intensive research efforts are directed toward improving its suitability for industrial application. Development of microbial strains capable of utilizing xylan-containing raw materials for growth or screening for constitutive mutants of GI is expected to lead to discontinuation of the use of xylose as an inducer for the production of the enzyme. Elimination of Co2+ from the fermentation medium is desirable for avoiding health problems arising from human consumption of HFCS. Immobilization of GI provides an efficient means for its easy recovery and reuse and lowers the cost of its use. X-ray crystallographic and genetic engineering studies support a hydride shift mechanism for the action of GI. Cloning of GI in homologous as well as heterologous hosts has been carried out, with the prime aim of overproducing the enzyme and deciphering the genetic organization of individual genes (xylA, xylB, and xylR) in the xyl operon of different microorganisms. The organization of xylA and xylB seems to be highly conserved in all bacteria. The two genes are transcribed from the same strand in Escherichia coli and Bacillus and Lactobacillus species, whereas they are transcribed divergently on different strands in Streptomyces species. A comparison of the xylA sequences from several bacterial sources revealed the

  8. Comparison of glucose oxidases from Penicillium adametzii, Penicillium Funiculosum and Aspergillus Niger in the design of amperometric glucose biosensors.

    PubMed

    Ramanavicius, Arunas; Voronovic, Jaroslav; Semashko, Tatiana; Mikhailova, Raisa; Kausaite-Minkstimiene, Asta; Ramanaviciene, Almira

    2014-01-01

    The properties of amperometric glucose biosensors based on three different glucose oxidases and various redox mediators were evaluated. Glucose oxidases (GOx) from Penicillium adametzii, Penicillium funiculosum and Aspergillus niger and artificial redox mediators, such as ferrocene, ferrocenecarboxaldehyde, α-methylferrocene methanol and ferrocenecarboxylic acid, were used for modifying the graphite rod electrode and amperometrical reagent-less glucose detection. The obtained results were compared using N-methylphenazonium methyl sulphate in the solution. Taking into account the experimental kinetic parameters and the stability of the tested enzymatic electrodes, GOx from Penicillium funiculosum proved to be more suitable for glucose biosensor design in comparison with other evaluated enzymes. PMID:25492463

  9. Rice (Oryza sativa japonica) Albumin Suppresses the Elevation of Blood Glucose and Plasma Insulin Levels after Oral Glucose Loading.

    PubMed

    Ina, Shigenobu; Ninomiya, Kazumi; Mogi, Takashi; Hase, Ayumu; Ando, Toshiki; Matsukaze, Narumi; Ogihara, Jun; Akao, Makoto; Kumagai, Hitoshi; Kumagai, Hitomi

    2016-06-22

    The suppressive effect of rice albumin (RA) of 16 kDa on elevation of blood glucose level after oral loading of starch or glucose and its possible mechanism were examined. RA suppressed the increase in blood glucose levels in both the oral starch tolerance test and the oral glucose tolerance test. The blood glucose concentrations 15 min after the oral administration of starch were 144 ± 6 mg/dL for control group and 127 ± 4 mg/dL for RA 200 mg/kg BW group, while those after the oral administration of glucose were 157 ± 7 mg/dL for control group and 137 ± 4 mg/dL for RA 200 mg/kg BW group. However, in the intraperitoneal glucose tolerance test, no significant differences in blood glucose level were observed between RA and the control groups, indicating that RA suppresses the glucose absorption from the small intestine. However, RA did not inhibit the activity of mammalian α-amylase. RA was hydrolyzed to an indigestible high-molecular-weight peptide (HMP) of 14 kDa and low-molecular-weight peptides by pepsin and pancreatin. Furthermore, RA suppressed the glucose diffusion rate through a semipermeable membrane like dietary fibers in vitro. Therefore, the indigestible HMP may adsorb glucose and suppress its absorption from the small intestine. PMID:27228466

  10. Quantifying the Contribution of the Liver to Glucose Homeostasis: A Detailed Kinetic Model of Human Hepatic Glucose Metabolism

    PubMed Central

    König, Matthias; Bulik, Sascha; Holzhütter, Hermann-Georg

    2012-01-01

    Despite the crucial role of the liver in glucose homeostasis, a detailed mathematical model of human hepatic glucose metabolism is lacking so far. Here we present a detailed kinetic model of glycolysis, gluconeogenesis and glycogen metabolism in human hepatocytes integrated with the hormonal control of these pathways by insulin, glucagon and epinephrine. Model simulations are in good agreement with experimental data on (i) the quantitative contributions of glycolysis, gluconeogenesis, and glycogen metabolism to hepatic glucose production and hepatic glucose utilization under varying physiological states. (ii) the time courses of postprandial glycogen storage as well as glycogen depletion in overnight fasting and short term fasting (iii) the switch from net hepatic glucose production under hypoglycemia to net hepatic glucose utilization under hyperglycemia essential for glucose homeostasis (iv) hormone perturbations of hepatic glucose metabolism. Response analysis reveals an extra high capacity of the liver to counteract changes of plasma glucose level below 5 mM (hypoglycemia) and above 7.5 mM (hyperglycemia). Our model may serve as an important module of a whole-body model of human glucose metabolism and as a valuable tool for understanding the role of the liver in glucose homeostasis under normal conditions and in diseases like diabetes or glycogen storage diseases. PMID:22761565

  11. Recommendations for Standardizing Glucose Reporting and Analysis to Optimize Clinical Decision Making in Diabetes: The Ambulatory Glucose Profile

    PubMed Central

    Bergenstal, Richard M.; Ahmann, Andrew J.; Bailey, Timothy; Beck, Roy W.; Bissen, Joan; Buckingham, Bruce; Deeb, Larry; Dolin, Robert H.; Garg, Satish K.; Goland, Robin; Hirsch, Irl B.; Klonoff, David C.; Kruger, Davida F.; Matfin, Glenn; Mazze, Roger S.; Olson, Beth A.; Parkin, Christopher; Peters, Anne; Powers, Margaret A.; Rodriguez, Henry; Southerland, Phil; Strock, Ellie S.; Tamborlane, William; Wesley, David M.

    2013-01-01

    Underutilization of glucose data and lack of easy and standardized glucose data collection, analysis, visualization, and guided clinical decision making are key contributors to poor glycemic control among individuals with type 1 diabetes mellitus. An expert panel of diabetes specialists, facilitated by the International Diabetes Center and sponsored by the Helmsley Charitable Trust, met in 2012 to discuss recommendations for standardizing the analysis and presentation of glucose monitoring data, with the initial focus on data derived from continuous glucose monitoring systems. The panel members were introduced to a universal software report, the Ambulatory Glucose Profile, and asked to provide feedback on its content and functionality, both as a research tool and in clinical settings. This article provides a summary of the topics and issues discussed during the meeting and presents recommendations from the expert panel regarding the need to standardize glucose profile summary metrics and the value of a uniform glucose report to aid clinicians, researchers, and patients. PMID:23567014

  12. Self-assembled graphene platelet-glucose oxidase nanostructures for glucose biosensing.

    PubMed

    Liu, Sen; Tian, Jingqi; Wang, Lei; Luo, Yonglan; Lu, Wenbo; Sun, Xuping

    2011-07-15

    Graphene platelet-glucose oxidase (GP-GOD) nanostructures have been prepared through self-assembly of GOD and chitosan (CS) functionalized GPs by electrostatic attraction in aqueous solution. The stable aqueous dispersion of GPs was prepared by chemical reduction of graphene oxide with the use of CS as a reducing and stabilizing agent. UV-vis spectroscopy, X-ray diffraction, transmission electron microscopy, scanning electron microscopy and X-ray photoelectron spectroscopy were used to characterize the resulting GPs and GP-GOD nanostructures. Furthermore, a glucose biosensor was constructed by deposition of the resultant GP-GOD on the surface of glassy carbon electrode. It was found that the resulting biosensor exhibits good response to glucose. The linear detection range is estimated to be from 2 to 22 mM (r=0.9987), and the detection limit is estimated to be 20 μM at a signal-to-noise ratio of 3. PMID:21652199

  13. Enzymatic growth of quantum dots: applications to probe glucose oxidase and horseradish peroxidase and sense glucose.

    PubMed

    Saa, Laura; Pavlov, Valeri

    2012-11-19

    Three innovative assays are developed for the detection of enzymatic activities of glucose oxidase (GOx) and horseradish peroxidase (HRP) by the generation of CdS quantum dots (QDs) in situ using non-conventional enzymatic reactions. In the first assay, GOx catalyzes the oxidation of 1-thio-β-D-glucose to give 1-thio-β-D-gluconic acid. The latter is spontaneously hydrolyzed to β-D-gluconic acid and H2 S, which in the presence of cadmium nitrate yields fluorescent CdS nanoparticles. In the second assay HRP catalyzes the oxidation of sodium thiosulfate with hydrogen peroxide generating H2 S and consequently CdS QDs. The combination of GOx with HRP, allowed quantification of glucose in plasma by following growth of fluorescent QDs. PMID:22887879

  14. Electrochemical Glucose Biosensor Based on Glucose Oxidase Displayed on Yeast Surface.

    PubMed

    Wang, Hongwei; Lang, Qiaolin; Liang, Bo; Liu, Aihua

    2015-01-01

    The conventional enzyme-based biosensor requires chemical or physical immobilization of purified enzymes on electrode surface, which often results in loss of enzyme activity and/or fractions immobilized over time. It is also costly. A major advantage of yeast surface display is that it enables the direct utilization of whole cell catalysts with eukaryote-produced proteins being displayed on the cell surface, providing an economic alternative to traditional production of purified enzymes. Herein, we describe the details of the display of glucose oxidase (GOx) on yeast cell surface and its application in the development of electrochemical glucose sensor. In order to achieve a direct electrochemistry of GOx, the entire cell catalyst (yeast-GOx) was immobilized together with multiwalled carbon nanotubes on the electrode, which allowed sensitive and selective glucose detection. PMID:26060079

  15. Multifunctional carbon nanotubes for direct electrochemistry of glucose oxidase and glucose bioassay.

    PubMed

    Wang, Yinling; Liu, Lin; Li, Maoguo; Xu, Shudong; Gao, Feng

    2011-12-15

    Polydopamine (Pdop) has recently been shown to adsorb to a wide variety of surfaces and serves as an adhesion layer to immobilize biological molecules. In this work, the multifunctional carbon nanotube (CNT) composites were prepared though the oxidation of dopamine at room temperature and subsequent electroless silver deposition by mildly stirring. The stable immobilization and direct electron transfer of glucose oxidase were achieved on the composite film modified glassy carbon electrode. The resulting electrode gave a well-defined redox peaks with a formal potential of about -482 mV (vs. SCE) in pH 7.0 buffer. The electron transfer rate constant was estimated to be 3.6 s(-1), due to the combined contribution of Pdop, CNTs and Ag nanoparticles with the help of Nafion. Furthermore, the method for detecting of glucose was proposed based on the decrease of oxygen caused by the enzyme-catalyzed reaction between glucose oxidase (GOD) and glucose. The linear response to glucose ranging from 50.0 μM to 1.1 mM (R(2)=0.9958), with a calculated detection limit of 17.0 μM at a signal-to-noise ratio of 3. The low calculated apparent Michaelis-Menten constant (K(M)(app)) was 5.46 mM, implying the high enzymatic activity and affinity of immobilized GOD for glucose. It can reasonably be expected that this observation might hold true for other noble metal nanostructure-electroactive protein systems, providing a promising platform for the development of biosensors and biofuel cells. PMID:21959226

  16. Genetic variation in GIPR influences the glucose and insulin responses to an oral glucose challenge

    PubMed Central

    Saxena, Richa; Hivert, Marie-France; Langenberg, Claudia; Tanaka, Toshiko; Pankow, James S; Vollenweider, Peter; Lyssenko, Valeriya; Bouatia-Naji, Nabila; Dupuis, Josée; Jackson, Anne U; Kao, W H Linda; Li, Man; Glazer, Nicole L; Manning, Alisa K; Luan, Jian’an; Stringham, Heather M; Prokopenko, Inga; Johnson, Toby; Grarup, Niels; Boesgaard, Trine W; Lecoeur, Cécile; Shrader, Peter; O’Connell, Jeffrey; Ingelsson, Erik; Couper, David J; Rice, Kenneth; Song, Kijoung; Andreasen, Camilla H; Dina, Christian; Köttgen, Anna; Le Bacquer, Olivier; Pattou, François; Taneera, Jalal; Steinthorsdottir, Valgerdur; Rybin, Denis; Ardlie, Kristin; Sampson, Michael; Qi, Lu; van Hoek, Mandy; Weedon, Michael N; Aulchenko, Yurii S; Voight, Benjamin F; Grallert, Harald; Balkau, Beverley; Bergman, Richard N; Bielinski, Suzette J; Bonnefond, Amelie; Bonnycastle, Lori L; Borch-Johnsen, Knut; Böttcher, Yvonne; Brunner, Eric; Buchanan, Thomas A; Bumpstead, Suzannah J; Cavalcanti-Proença, Christine; Charpentier, Guillaume; Chen, Yii-Der Ida; Chines, Peter S; Collins, Francis S; Cornelis, Marilyn; Crawford, Gabriel J; Delplanque, Jerome; Doney, Alex; Egan, Josephine M; Erdos, Michael R; Firmann, Mathieu; Forouhi, Nita G; Fox, Caroline S; Goodarzi, Mark O; Graessler, Jürgen; Hingorani, Aroon; Isomaa, Bo; Jørgensen, Torben; Kivimaki, Mika; Kovacs, Peter; Krohn, Knut; Kumari, Meena; Lauritzen, Torsten; Lévy-Marchal, Claire; Mayor, Vladimir; McAteer, Jarred B; Meyre, David; Mitchell, Braxton D; Mohlke, Karen L; Morken, Mario A; Narisu, Narisu; Palmer, Colin N A; Pakyz, Ruth; Pascoe, Laura; Payne, Felicity; Pearson, Daniel; Rathmann, Wolfgang; Sandbaek, Annelli; Sayer, Avan Aihie; Scott, Laura J; Sharp, Stephen J; Sijbrands, Eric; Singleton, Andrew; Siscovick, David S; Smith, Nicholas L; Sparsø, Thomas; Swift, Amy J; Syddall, Holly; Thorleifsson, Gudmar; Tönjes, Anke; Tuomi, Tiinamaija; Tuomilehto, Jaakko; Valle, Timo T; Waeber, Gérard; Walley, Andrew; Waterworth, Dawn M; Zeggini, Eleftheria; Zhao, Jing Hua; Illig, Thomas; Wichmann, H Erich; Wilson, James F; van Duijn, Cornelia; Hu, Frank B; Morris, Andrew D; Frayling, Timothy M; Hattersley, Andrew T; Thorsteinsdottir, Unnur; Stefansson, Kari; Nilsson, Peter; Syvänen, Ann-Christine; Shuldiner, Alan R; Walker, Mark; Bornstein, Stefan R; Schwarz, Peter; Williams, Gordon H; Nathan, David M; Kuusisto, Johanna; Laakso, Markku; Cooper, Cyrus; Marmot, Michael; Ferrucci, Luigi; Mooser, Vincent; Stumvoll, Michael; Loos, Ruth J F; Altshuler, David; Psaty, Bruce M; Rotter, Jerome I; Boerwinkle, Eric; Hansen, Torben; Pedersen, Oluf; Florez, Jose C; McCarthy, Mark I; Boehnke, Michael; Barroso, Inês; Sladek, Robert; Froguel, Philippe; Meigs, James B; Groop, Leif; Wareham, Nicholas J; Watanabe, Richard M

    2010-01-01

    Glucose levels 2 h after an oral glucose challenge are a clinical measure of glucose tolerance used in the diagnosis of type 2 diabetes. We report a meta-analysis of nine genome-wide association studies (n = 15,234 nondiabetic individuals) and a follow-up of 29 independent loci (n = 6,958–30,620). We identify variants at the GIPR locus associated with 2-h glucose level (rs10423928, β (s.e.m.) = 0.09 (0.01) mmol/l per A allele, P = 2.0 × 10−15). The GIPR A-allele carriers also showed decreased insulin secretion (n = 22,492; insulinogenic index, P = 1.0 × 10−17; ratio of insulin to glucose area under the curve, P = 1.3 × 10−16) and diminished incretin effect (n = 804; P = 4.3 × 10−4). We also identified variants at ADCY5 (rs2877716, P = 4.2 × 10−16), VPS13C (rs17271305, P = 4.1 × 10−8), GCKR (rs1260326, P = 7.1 × 10−11) and TCF7L2 (rs7903146, P = 4.2 × 10−10) associated with 2-h glucose. Of the three newly implicated loci (GIPR, ADCY5 and VPS13C), only ADCY5 was found to be associated with type 2 diabetes in collaborating studies (n = 35,869 cases, 89,798 controls, OR = 1.12, 95% CI 1.09–1.15, P = 4.8 × 10−18). PMID:20081857

  17. The Tuberous Sclerosis Complex Regulates Trafficking of Glucose Transporters and Glucose Uptake

    PubMed Central

    Jiang, Xiuyun; Kenerson, Heidi; Aicher, Lauri; Miyaoka, Robert; Eary, Janet; Bissler, John; Yeung, Raymond S.

    2008-01-01

    Human cancers often display an avidity for glucose, a feature that is exploited in clinical staging and response monitoring by using 18F-fluoro-deoxyglucose (FDG) positron emission tomography. Determinants of FDG accumulation include tumor blood flow, glucose transport, and glycolytic rate, but the underlying molecular mechanisms are incompletely understood. The phosphoinositide-3 kinase/Akt/mammalian target of rapamycin complex (mTORC) 1 pathway has been implicated in this process via the hypoxia-inducible factor alpha-dependent expression of vascular endothelial growth factor and glycolytic enzymes. Thus, we predicted that tumors with elevated mTORC1 activity would be accompanied by high FDG uptake. We tested this hypothesis in eight renal angiomyolipomas in which the loss of tuberous sclerosis complex (TSC) 1/2 function gave rise to constitutive mTORC1 activation. Surprisingly, these tumors displayed low FDG uptake on positron emission tomography. Exploring the underlying mechanisms in vitro revealed that Tsc2 regulates the membrane localization of the glucose transporter proteins (Glut)1, Glut2, and Glut4, and, therefore, glucose uptake. Down-regulation of cytoplasmic linker protein 170, an mTOR effector, rescued Glut4 trafficking in Tsc2−/− cells, whereas up-regulation of Akt activity in these cells was insufficient to redistribute Glut4 to the plasma membrane. The effect of mTORC1 on glucose uptake was confirmed using a liver-specific Tsc1- deletion mouse model in which FDG uptake was reduced in the livers of mutant mice compared with wild-type controls. Together, these data show that mTORC1 activity is insufficient for increased glycolysis in tumors and that constitutive mTOR activity negatively regulates glucose transporter trafficking. PMID:18511518

  18. CGM Versus FGM; or, Continuous Glucose Monitoring Is Not Flash Glucose Monitoring.

    PubMed

    Heinemann, Lutz; Freckmann, Guido

    2015-09-01

    It remains to be seen as to what share of the market FGM will achieve if the manufacturer can supply any amount desired.Will a significant portion of the glucose monitoring market then be taken over by FGM? The availability of FGM as anew option for glucose monitoring can basically be evaluated positively and it does indeed clearly show the benefit of“more information” on the glucose trend. The relatively low price for glucose monitoring using FGM and the unusual market introduction (not first via the National Association of Statutory Health Insurance Funds, as was the case with CGM) have given increased attention to the use of more glucose information. It will likely take a certain amount of time before other providers are able to bring different FGM systems to the market.The option of coupling a CGM system with an insulin pump offers the perspective of an automated insulin application,that is, a closed-loop system. Such systems are currently being tested under everyday conditions, although it is not possible to predict when they will actually reach the market.There are, however, such couplings where algorithms are responsible for shutting off insulin delivery when the glucose concentration reaches a defined level or if it will be reached in the foreseeable future. This significantly helps prevent hypoglycemia. These options are only available with CGM. The aim of this commentary is to present the differences between CGM and FGM, including the advantages and disadvantages of both approaches. We see significant benefits in both options based on the different positioning of the approaches and the different user groups. PMID:26330484

  19. Electron-transfer mediator for a NAD-glucose dehydrogenase-based glucose sensor.

    PubMed

    Kim, Dong-Min; Kim, Min-yeong; Reddy, Sanapalli S; Cho, Jaegeol; Cho, Chul-ho; Jung, Suntae; Shim, Yoon-Bo

    2013-12-01

    A new electron-transfer mediator, 5-[2,5-di (thiophen-2-yl)-1H-pyrrol-1-yl]-1,10-phenanthroline iron(III) chloride (FePhenTPy) oriented to the nicotinamide adenine dinucleotide-dependent-glucose dehydrogenase (NAD-GDH) system was synthesized through a Paal-Knorr condensation reaction. The structure of the mediator was confirmed by Fourier-transform infrared spectroscopy, proton and carbon nucler magnetic resonance spectroscopy, and mass spectroscopy, and its electron-transfer characteristic for a glucose sensor was investigated using voltammetry and impedance spectroscopy. A disposable amperometric glucose sensor with NAD-GDH was constructed with FePhenTPy as an electron-transfer mediator on a screen printed carbon electrode (SPCE) and its performance was evaluated, where the addition of reduces graphene oxide (RGO) to the mediator showed the enhanced sensor performance. The experimental parameters to affect the analytical performance and the stability of the proposed glucose sensor were optimized, and the sensor exhibited a dynamic range between 30 mg/dL and 600 mg/dL with the detection limit of 12.02 ± 0.6 mg/dL. In the real sample experiments, the interference effects by acetaminophen, ascorbic acid, dopamine, uric acid, caffeine, and other monosaccharides (fructose, lactose, mannose, and xylose) were completely avoided through coating the sensor surface with the Nafion film containing lead(IV) acetate. The reliability of proposed glucose sensor was evaluated by the determination of glucose in artificial blood and human whole blood samples. PMID:24199942

  20. Chlorogenic acid differentially affects postprandial glucose and glucose-dependent insulinotropic polypeptide response in rats.

    PubMed

    Tunnicliffe, Jasmine M; Eller, Lindsay K; Reimer, Raylene A; Hittel, Dustin S; Shearer, Jane

    2011-10-01

    Regular coffee consumption significantly lowers the risk of type 2 diabetes (T2D). Coffee contains thousands of compounds; however, the specific component(s) responsible for this reduced risk is unknown. Chlorogenic acids (CGA) found in brewed coffee inhibit intestinal glucose uptake in vitro. The objective of this study was to elucidate the mechanisms by which CGA acts to mediate blood glucose response in vivo. Conscious, unrestrained, male Sprague-Dawley rats were chronically catheterized and gavage-fed a standardized meal (59% carbohydrate, 25% fat, 12% protein), administered with or without CGA (120 mg·kg(-1)), in a randomized crossover design separated by a 3-day washout period. Acetaminophen was co-administered to assess the effects of CGA on gastric emptying. The incretins glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP) were measured. GLP-1 response in the presence of glucose and CGA was further examined, using the human colon cell line NCI-H716. Total area under the curve (AUC) for blood glucose was significantly attenuated in rats fed CGA (p < 0.05). Despite this, no differences in plasma insulin or nonesterified fatty acids were observed, and gastric emptying was not altered. Plasma GIP response was blunted in rats fed CGA, with a lower peak concentration and AUC up to 180 min postprandially (p < 0.05). There were no changes in GLP-1 secretion in either the in vivo or in vitro study. In conclusion, CGA treatment resulted in beneficial effects on blood glucose response, with alterations seen in GIP concentrations. Given the widespread consumption and availability of coffee, CGA may be a viable prevention tool for T2D. PMID:21977912

  1. Glucose Supply and Insulin Demand Dynamics of Antidiabetic Agents

    PubMed Central

    Monte, Scott V.; Schentag, Jerome J.; Adelman, Martin H.; Paladino, Joseph A.

    2010-01-01

    Background For microvascular outcomes, there is compelling historical and contemporary evidence for intensive blood glucose reduction in patients with either type 1 diabetes mellitus (T1DM) or type 2 diabetes mellitus (T2DM). There is also strong evidence to support macrovascular benefit with intensive blood glucose reduction in T1DM. Similar evidence remains elusive for T2DM. Because cardiovascular outcome trials utilizing conventional algorithms to attain intensive blood glucose reduction have not demonstrated superiority to less aggressive blood glucose reduction (Action to Control Cardiovascular Risk in Diabetes; Action in Diabetes and Vascular Disease: Preterax and Diamicron Modified Release Controlled Evaluation; and Veterans Affairs Diabetes Trial), it should be considered that the means by which the blood glucose is reduced may be as important as the actual blood glucose. Methods By identifying quantitative differences between antidiabetic agents on carbohydrate exposure (CE), hepatic glucose uptake (HGU), hepatic gluconeogenesis (GNG), insulin resistance (IR), peripheral glucose uptake (PGU), and peripheral insulin exposure (PIE), we created a pharmacokinetic/pharmacodynamic model to characterize the effect of the agents on the glucose supply and insulin demand dynamic. Glucose supply was defined as the cumulative percentage decrease in CE, increase in HGU, decrease in GNG, and decrease in IR, while insulin demand was defined as the cumulative percentage increase in PIE and PGU. With the glucose supply and insulin demand effects of each antidiabetic agent summated, the glucose supply (numerator) was divided by the insulin demand (denominator) to create a value representative of the glucose supply and insulin demand dynamic (SD ratio). Results Alpha-glucosidase inhibitors (1.25), metformin (2.20), and thiazolidinediones (TZDs; 1.25–1.32) demonstrate a greater effect on glucose supply (SD ratio >1), while secretagogues (0.69–0.81), basal insulins (0.77

  2. Contribution of propionate to glucose synthesis in sheep

    PubMed Central

    Leng, R. A.; Steel, J. W.; Luick, J. R.

    1967-01-01

    1. The production rate of propionate in the rumen and the entry rate of glucose into the body pool of glucose in sheep were measured by isotope-dilution methods. Propionate production rates were measured by using a continuous infusion of specifically labelled [14C]propionate. Glucose entry rates were estimated by using either a primed infusion or a continuous infusion of [U-14C]glucose. 2. The specific radioactivity of plasma glucose was constant between 4 and 9hr. after the commencement of intravenous infusion of [U-14C]glucose and between 1 and 3hr. when a primed infusion was used. 3. Infusion of [14C]propionate intraruminally resulted in a fairly constant specific radioactivity of rumen propionate between about 4 and 9hr. and of plasma glucose between 6 and 9hr. after the commencement of the infusion. Comparison of the mean specific radioactivities of glucose and propionate during these periods allowed estimates to be made of the contribution of propionate to glucose synthesis. 4. Comparisons of the specific radioactivities of plasma glucose and rumen propionate during intraruminal infusions of one of [1-14C]-, [2-14C]-, [3-14C]- and [U-14C]-propionate indicated considerable exchange of C-1 of propionate on conversion into glucose. The incorporation of C-2 and C-3 of propionate into glucose and lactate indicated that 54% of both the glucose and lactate synthesized arose from propionate carbon. 5. No differences were found for glucose entry rates measured either by a primed infusion or by a continuous infusion. The mean entry rate (±s.e.m.) of glucose estimated by using a continuous infusion into sheep was 0·33±0·03 (4) m-mole/min. and by using a primed infusion was 0·32±0·01 (4) m-mole/min. The mean propionate production rate was 1·24±0·03 (8) m-moles/min. The conversion of propionate into glucose was 0·36 m-mole/min., indicating that 32% of the propionate produced in the rumen is used for glucose synthesis. 6. It was indicated that a considerable

  3. Dynamics of the reaction glucose-catalase-glucose oxidase-hydrogen peroxide

    NASA Astrophysics Data System (ADS)

    Číp, M.; Schreiberová, L.; Schreiber, I.

    2011-12-01

    Glucose-catalase-glucose oxidase-hydrogen peroxide reaction is one of the few known enzymatic systems studied in vitro in the field of nonlinear chemical dynamics. This reaction belongs to the family of oscillatory enzymatic reactions, which form a natural basis of oscillations in biological systems. A parametric study of dependence on mixing, temperature and initial concentrations of components in a batch stirred reactor was carried out. A newly proposed mathematical model of the reaction conforms to the obtained experimental data. Results of our experiments and simulations hint at further directions of research of non-linear dynamics in this reaction.

  4. [Glucose control in the critically ill. Innovations and contemporary strategies].

    PubMed

    Holzinger, U

    2013-06-01

    Glucose control should be part of standard therapy in intensive care units (ICU) due to the proven association of hyperglycemia with increased morbidity and mortality. Due to the results of the lat