Science.gov

Sample records for glucose study phase

  1. Phase modulation of insulin pulses enhances glucose regulation and enables inter-islet synchronization

    PubMed Central

    Lee, Boah; Song, Taegeun; Lee, Kayoung; Kim, Jaeyoon; Han, Seungmin; Berggren, Per-Olof; Ryu, Sung Ho; Jo, Junghyo

    2017-01-01

    Insulin is secreted in a pulsatile manner from multiple micro-organs called the islets of Langerhans. The amplitude and phase (shape) of insulin secretion are modulated by numerous factors including glucose. The role of phase modulation in glucose homeostasis is not well understood compared to the obvious contribution of amplitude modulation. In the present study, we measured Ca2+ oscillations in islets as a proxy for insulin pulses, and we observed their frequency and shape changes under constant/alternating glucose stimuli. Here we asked how the phase modulation of insulin pulses contributes to glucose regulation. To directly answer this question, we developed a phenomenological oscillator model that drastically simplifies insulin secretion, but precisely incorporates the observed phase modulation of insulin pulses in response to glucose stimuli. Then, we mathematically modeled how insulin pulses regulate the glucose concentration in the body. The model of insulin oscillation and glucose regulation describes the glucose-insulin feedback loop. The data-based model demonstrates that the existence of phase modulation narrows the range within which the glucose concentration is maintained through the suppression/enhancement of insulin secretion in conjunction with the amplitude modulation of this secretion. The phase modulation is the response of islets to glucose perturbations. When multiple islets are exposed to the same glucose stimuli, they can be entrained to generate synchronous insulin pulses. Thus, we conclude that the phase modulation of insulin pulses is essential for glucose regulation and inter-islet synchronization. PMID:28235104

  2. Reforming and decomposition of glucose in an aqueous phase

    NASA Technical Reports Server (NTRS)

    Amin, S.; Reid, R. C.; Modell, M.

    1975-01-01

    Exploratory experiments have been carried out to study the decomposition of glucose, a typical carbohydrate, in a high temperature-high pressure water reactor. The objective of the study was to examine the feasibility of such a process to decompose cellulosic waste materials in long-term space missions. At temperatures below the critical point of water, glucose decomposed to form liquid products and char. Little gas was noted with or without reforming catalysts present. The rate of the primary glucose reaction increased significantly with temperature. Partial identification of the liquid phase was made and the C:H:O ratios determined for both the liquid and solid products. One of the more interesting results from this study was the finding that when glucose was injected into a reactor held at the critical temperature (and pressure) of water, no solid products formed. Gas production increased, but the majority of the carbon was found in soluble furans (and furan derivatives). This significant result is now being investigated further.

  3. Familial Aggregation of Metabolic Syndrome With Different Socio-Behavioral Characteristics: The Fourth Phase of Tehran Lipid and Glucose Study

    PubMed Central

    Zarkesh, Maryam; Asghari, Golaleh; Amiri, Parisa; Hosseinzadeh, Nima; Hedayati, Mehdi; Ghanbarian, Arash; Azizi, Fereidoun

    2016-01-01

    Background Since genetic and most environmental factors shape the context of families, some studies have been initiated to investigate the role of familial relationships in metabolic syndrome (MetS). Objectives To estimate the familial aggregation of MetS and its components by identifying both case and control probands among Tehranian adults with different socio-behavioral and reproductive characteristics. Patients and Methods This case-controlled/family-based study was conducted on 1,777 families (635 case probands) who participated in the Tehran Lipid and Glucose Study (TLGS). Socio-demographic and reproductive information including levels of education, marital status, occupation status, age at menarche, number of abortions, number of children, and lifestyle habits such as smoking, physical activity and regular diet were obtained from the TLGS data bank. Metabolic syndrome was defined according to the joint interim statement (JIS) criteria. To estimate the regression co-efficient for familial aggregation and environmental factors, the generalized estimation equation method was used. Results The risk of having MetS among family members for case versus control probands was 2.19 (95% CI: 1.68 - 2.84), which, after adjusting for potential confounders including age, sex, educational level, marital status, occupation, age at menarche and energy, soft drink and starchy vegetable intake, increased to 2.31 (95% CI: 1.81 - 2.94; P < 0.05). Compared to control probands, the risk of having MetS components increased significantly from OR = 1.28 for both high waist circumference (WC) and blood pressure (BP) to OR = 1.72 for high triglycerides in cases. Familial aggregation inherited from the father was significantly observed in all MetS components, from adjusted OR = 1.63 for hyperglycemia to adjusted OR = 2.69 for high WC, except for low HDL, after controlling for potential confounders. Conclusions Considering spouses and siblings, there was a higher risk for MetS components

  4. In vivo glucose utilization in rat tissues during the three phases of starvation

    SciTech Connect

    Cherel, Y.; Burnol, A.F.; Leturque, A.; Le Maho, Y.

    1988-11-01

    Three phases of starvation have been described from changes in protein and lipid utilization in birds and mammals. In the present study, tissue glucose utilization was measured in vivo during these three phases, using a 2-deoxy-(1-3H)glucose technique in the anesthetized rat. According to this technique, the term glucose utilization therefore refers to transport and phosphorylation of glucose in tissues, ie, whatever is the fate of glucose. Whole-body glucose turnover rate, which was determined by a continuous infusion of (3-3H)glucose, decreased by 40% during the first two days of starvation (phase 1); it did not change thereafter, neither in the protein-sparing phase 2 nor in phase 3, which is marked by an increase in net protein breakdown. Two days of starvation caused a marked decrease in the glucose utilization in skeletal muscles; this decrease was higher in oxidative muscles (65% in diaphragm, 66% in soleus) than in glycolytic muscles (31% in extensor digitorum longus, 34% in epitrochlearis). Glucose utilization also decreased in heart atria (75%), heart ventricles (93%), and white adipose tissue (54%); by contrast, there was a two-fold increase in glucose utilization in brown adipose tissue and no change in brain and skin. No variations were observed in glucose utilization in any of the tissues from phase 1 to phase 2. However, phase 3 was marked by a decrease in glucose utilization in extensor digitorum longus (45%), brown adipose tissue (76%), brain (29%), and skin (40%), whereas there was a 2.3- and 3.4-fold increase in glucose utilization in diaphragm and heart ventricles, respectively.

  5. Thermodynamically controlled crystallization of glucose pentaacetates from amorphous phase

    NASA Astrophysics Data System (ADS)

    Wlodarczyk, P.; Hawelek, L.; Hudecki, A.; Wlodarczyk, A.; Kolano-Burian, A.

    2016-08-01

    The α and β glucose pentaacetates are known sugar derivatives, which can be potentially used as stabilizers of amorphous phase of active ingredients of drugs (API). In the present work, crystallization behavior of equimolar mixture of α and β form in comparison to both pure anomers is revealed. It was shown that despite the same molecular interactions and similar molecular dynamics, crystallization from amorphous phase is significantly suppressed in equimolar mixture. Time dependent X-ray diffraction studies confirmed higher stability of the quenched amorphous equimolar mixture. Its tendency to crystallization is about 10 times lower than for pure anomers. Calorimetric studies revealed that the α and β anomers don't form solid solutions and have eutectic point for xα = 0.625. Suppressed crystallization tendency in the mixture is probably caused by the altered thermodynamics of the system. The factors such as difference of free energy between crystalline and amorphous state or altered configurational entropy are probably responsible for the inhibitory effect.

  6. Myo-inositol inhibits intestinal glucose absorption and promotes muscle glucose uptake: a dual approach study.

    PubMed

    Chukwuma, Chika Ifeanyi; Ibrahim, Mohammed Auwal; Islam, Md Shahidul

    2016-12-01

    The present study investigated the effects of myo-inositol on muscle glucose uptake and intestinal glucose absorption ex vivo as well as in normal and type 2 diabetes model of rats. In ex vivo study, both intestinal glucose absorption and muscle glucose uptake were studied in isolated rat jejunum and psoas muscle respectively in the presence of increasing concentrations (2.5 % to 20 %) of myo-inositol. In the in vivo study, the effect of a single bolus dose (1 g/kg bw) of oral myo-inositol on intestinal glucose absorption, blood glucose, gastric emptying and digesta transit was investigated in normal and type 2 diabetic rats after 1 h of co-administration with 2 g/kg bw glucose, when phenol red was used as a recovery marker. Myo-inositol inhibited intestinal glucose absorption (IC50 = 28.23 ± 6.01 %) and increased muscle glucose uptake, with (GU50 = 2.68 ± 0.75 %) or without (GU50 = 8.61 ± 0.55 %) insulin. Additionally, oral myo-inositol not only inhibited duodenal glucose absorption and reduced blood glucose increase, but also delayed gastric emptying and accelerated digesta transit in both normal and diabetic animals. Results of this study suggest that dietary myo-inositol inhibits intestinal glucose absorption both in ex vivo and in normal or diabetic rats and also promotes muscle glucose uptake in ex vivo condition. Hence, myo-inositol may be further investigated as a possible anti-hyperglycaemic dietary supplement for diabetic foods and food products.

  7. Phosphoinositides Are Involved in Control of the Glucose-Dependent Growth Resumption That Follows the Transition Phase in Streptomyces lividans▿

    PubMed Central

    Chouayekh, H.; Nothaft, H.; Delaunay, S.; Linder, M.; Payrastre, B.; Seghezzi, N.; Titgemeyer, F.; Virolle, M. J.

    2007-01-01

    The interruption of the sblA gene of Streptomyces lividans was previously shown to lead to relief of glucose repression of the normally strongly glucose-repressed α-amylase gene. In addition to this relief, an early entry into stationary phase was observed when cells were grown in a minimal medium containing glucose as the main carbon source. In this study, we established that this mutant does not resume growth after the transition phase when cultured in the complex glucose-rich liquid medium R2YE and sporulates much earlier than the wild-type strain when plated on solid R2YE. These phenotypic differences, which were abolished when glucose was omitted from the R2YE medium, correlated with a reduced glucose uptake ability of the sblA mutant strain. sblA was shown to encode a bifunctional enzyme possessing phospholipase C-like and phosphoinositide phosphatase activities. The cleavage of phosphoinositides by SblA seems necessary to trigger the glucose-dependent renewed growth that follows the transition phase. The transient expression of sblA that takes place just before the transition phase is consistent with a regulatory role for this gene during the late stages of growth. The tight temporal control of sblA expression was shown to depend on two operator sites. One, located just upstream of the −35 promoter region, likely constitutes a repressor binding site. The other, located 170 bp downstream of the GTG sblA translational start codon, may be involved in the regulation of the degradation of the sblA transcript. This study suggests that phosphoinositides constitute important regulatory molecules in Streptomyces, as they do in eukaryotes. PMID:17122350

  8. Menstrual cycle phase and sex influence muscle glycogen utilization and glucose turnover during moderate-intensity endurance exercise.

    PubMed

    Devries, Michaela C; Hamadeh, Mazen J; Phillips, Stuart M; Tarnopolsky, Mark A

    2006-10-01

    Numerous studies from our and other laboratories have shown that women have a lower respiratory exchange ratio (RER) during exercise than equally trained men, indicating a greater reliance on fat oxidation. Differences in estrogen concentration between men and women likely play a role in this sex difference. Differing estrogen and progesterone concentrations during the follicular (FP) and luteal (LP) phases of the female menstrual cycle suggest that fuel use may also vary between phases. The purpose of the current study was to determine the effect of menstrual cycle phase and sex upon glucose turnover and muscle glycogen utilization during endurance exercise. Healthy, recreationally active young women (n = 13) and men (n = 11) underwent a primed constant infusion of [6,6-2H]glucose with muscle biopsies taken before and after a 90-min cycling bout at 65% peak O2 consumption. LP women had lower glucose rate of appearance (Ra, P = 0.03), rate of disappearance (Rd, P = 0.03), and metabolic clearance rate (MCR, P = 0.04) at 90 min of exercise and lower proglycogen (P = 0.04), macroglycogen (P = 0.04), and total glycogen (P = 0.02) utilization during exercise compared with FP women. Men had a higher RER (P = 0.02), glucose Ra (P = 0.03), Rd (P = 0.03), and MCR (P = 0.01) during exercise compared with FP women, and men had a higher RER at 75 and 90 min of exercise (P = 0.04), glucose Ra (P = 0.01), Rd (P = 0.01), and MCR (P = 0.001) and a greater PG utilization (P = 0.05) compared with LP women. We conclude that sex, and to a lesser extent menstrual cycle, influence glucose turnover and glycogen utilization during moderate-intensity endurance exercise.

  9. Glucose elicits cephalic-phase insulin release in mice by activating KATP channels in taste cells.

    PubMed

    Glendinning, John I; Frim, Yonina G; Hochman, Ayelet; Lubitz, Gabrielle S; Basile, Anthony J; Sclafani, Anthony

    2017-04-01

    The taste of sugar elicits cephalic-phase insulin release (CPIR), which limits the rise in blood glucose associated with meals. Little is known, however, about the gustatory mechanisms that trigger CPIR. We asked whether oral stimulation with any of the following taste stimuli elicited CPIR in mice: glucose, sucrose, maltose, fructose, Polycose, saccharin, sucralose, AceK, SC45647, or a nonmetabolizable sugar analog. The only taste stimuli that elicited CPIR were glucose and the glucose-containing saccharides (sucrose, maltose, Polycose). When we mixed an α-glucosidase inhibitor (acarbose) with the latter three saccharides, the mice no longer exhibited CPIR. This revealed that the carbohydrates were hydrolyzed in the mouth, and that the liberated glucose triggered CPIR. We also found that increasing the intensity or duration of oral glucose stimulation caused a corresponding increase in CPIR magnitude. To identify the components of the glucose-specific taste-signaling pathway, we examined the necessity of Calhm1, P2X2+P2X3, SGLT1, and Sur1. Among these proteins, only Sur1 was necessary for CPIR. Sur1 was not necessary, however, for taste-mediated attraction to sugars. Given that Sur1 is a subunit of the ATP-sensitive K(+) channel (KATP) channel and that this channel functions as a part of a glucose-sensing pathway in pancreatic β-cells, we asked whether the KATP channel serves an analogous role in taste cells. We discovered that oral stimulation with drugs known to increase (glyburide) or decrease (diazoxide) KATP signaling produced corresponding changes in glucose-stimulated CPIR. We propose that the KATP channel is part of a novel signaling pathway in taste cells that mediates glucose-induced CPIR.

  10. Proposal for study on IR light and glucose phantom interaction for human glucose quantification applications

    NASA Astrophysics Data System (ADS)

    Romo-Cárdenas, Gerardo S.; Sanchez-Lopez, Juan D.; Nieto-Hipolito, Juan I.; Cosio-León, María.; Luque-Morales, Priscy; Vazquez-Briseno, Mabel

    2016-09-01

    It has been established the importance of a constant glucose monitoring in order to keep a regular control for diabetes patients. Several medical studies accept the necessity of exploring alternatives for the traditional digital glucometer, given the pain and discomfort related to this technique, which can lead to a compromised control of the disease. Several efforts based on the application of IR spectroscopy had been done with favorable, yet not conclusive results. Therefore it's necessary to apply a comprehensive and interdisciplinary study based on the biochemical and optical properties of the glucose in the human body, in order to understand the interaction between this substance, its surroundings and IR light. These study propose a comprehensive approach of the glucose and IR light interaction, considering and combining important biochemical, physiological and optical properties, as well as some machine learning techniques for the data analysis. The results of this work would help to define the right parameters aiming to obtain an optical glucose quantification system and protocol.

  11. Peritoneal Dialysate Glucose Load and Systemic Glucose Metabolism in Non-Diabetics: Results from the GLOBAL Fluid Cohort Study

    PubMed Central

    Chess, James; Do, Jun-Young; Noh, Hyunjin; Lee, Hi-Bahl; Kim, Yong-Lim; Summers, Angela; Williams, Paul Ford; Davison, Sara; Dorval, Marc

    2016-01-01

    Background and Objectives Glucose control is a significant predictor of mortality in diabetic peritoneal dialysis (PD) patients. During PD, the local toxic effects of intra-peritoneal glucose are well recognized, but despite large amounts of glucose being absorbed, the systemic effects of this in non-diabetic patients are not clear. We sought to clarify whether dialysate glucose has an effect upon systemic glucose metabolism. Methods and Materials We analysed the Global Fluid Study cohort, a prospective, observational cohort study initiated in 2002. A subset of 10 centres from 3 countries with high data quality were selected (368 incident and 272 prevalent non-diabetic patients), with multilevel, multivariable analysis of the reciprocal of random glucose levels, and a stratified-by-centre Cox survival analysis. Results The median follow up was 5.6 and 6.4 years respectively in incident and prevalent patients. On multivariate analysis, serum glucose increased with age (β = -0.007, 95%CI -0.010, -0.004) and decreased with higher serum sodium (β = 0.002, 95%CI 0.0005, 0.003) in incident patients and increased with dialysate glucose (β = -0.0002, 95%CI -0.0004, -0.00006) in prevalent patients. Levels suggested undiagnosed diabetes in 5.4% of prevalent patients. Glucose levels predicted death in unadjusted analyses of both incident and prevalent groups but in an adjusted survival analysis they did not (for random glucose 6–10 compared with <6, Incident group HR 0.92, 95%CI 0.58, 1.46, Prevalent group HR 1.42, 95%CI 0.86, 2.34). Conclusions In prevalent non-diabetic patients, random glucose levels at a diabetic level are under-recognised and increase with dialysate glucose load. Random glucose levels predict mortality in unadjusted analyses, but this association has not been proven in adjusted analyses. PMID:27249020

  12. Change dynamics of RBC morphology after injection glucose for diabetes by diffraction phase microscope

    NASA Astrophysics Data System (ADS)

    Talaykova, N. A.; Kalyanov, A. L.; Lychagov, V. V.; Ryabukho, V. P.; Malinova, L. I.

    2013-11-01

    Experimental setup of diffraction phase microscope (DPM) with double low-coherence lighting system is presented in the paper. Algorithm of interference picture processing and optical thickness, height, volume and mean cells volume (MCV) of RBC calculating is shown. We demonstrate results of experiments with blood smears and ability of the method to calculate 3D model of the biological cells shape. Investigation change dynamics of RBC morphology after injection glucose for diabetes by DPM is shown in the paper.

  13. Glucose-dependent insulinotropic polypeptide confers early phase insulin release to oral glucose in rats: demonstration by a receptor antagonist.

    PubMed

    Lewis, J T; Dayanandan, B; Habener, J F; Kieffer, T J

    2000-10-01

    A novel GIP receptor antagonist was developed to evaluate the acute role of glucose-dependent insulinotropic polypeptide (GIP) in the insulin response to oral glucose in rats. Antisera to an extracellular epitope of the GIP receptor (GIPR) detected immunoreactive GIPR on rat pancreatic beta-cells. Purified GIPR antibody (GIPR Ab) specifically displaced GIP binding to the receptor and blocked GIP-mediated increases in intracellular cAMP. When delivered to rats by ip injection, GIPR Ab had a half-life of approximately 4 days. Treatment with GIPR Ab (1 microg/g BW) blocked the potentiation of glucose-stimulated insulin secretion by GIP (60 pmol) but not glucagon-like peptide-1 (GLP-1, 60 pmol) in anesthetized rats. The insulin response to oral glucose was delayed in conscious unrestrained rats that were pretreated with GIPR Ab. Plasma insulin levels were approximately 35% lower at 10 min in GIPR Ab treated animals compared with controls. As a result, the glucose excursion was greater in the GIPR Ab treated group. Fasting plasma glucose levels were not altered by GIPR Ab. We conclude that release of GIP following oral glucose may act as an anticipatory signal to pancreatic beta-cells to promote rapid release of insulin for glucose disposal.

  14. Kinetic study of hydrolysis of coconut fiber into glucose

    NASA Astrophysics Data System (ADS)

    Muhaimin, Sudiono, Sri

    2017-03-01

    Kinetic study of hydrolysis of coconut fiber into glucose has been done. The aim of this research was to study of the effect of time and temperature to the glucose as the result of the conversion of coconut fiber. The various temperature of the hydrolysis process were 30 °C, 48 °C, 72 °C and 95 °C and the various time of the hydrolysis process were 0, 15, 30, 60, 120, 180, 240, 300 minutes. A quantitative analysis was done by measured the concentration of the glucose as the result of the conversion of coconut fiber. The result showed that the rate constant from the various temperature were 3.10-4 minute-1; 8.10-4 minutees-1; 84.10-4 minute-1, and 205.10-4 minute-1, and the energy activation was 7,69. 103 kJ/mol.

  15. Density Functional Study of the Infrared Spectrum of Glucose and Glucose Monohydrates in the OH Stretch Region

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Density functional theory (DFT) has been used to calculate the structures and infrared spectra of glucose and glucose monohydrates. Both the alpha and beta anomers were studied, with all possible combinations of hydroxymethyl rotamer (gg, gt, or tg) and hydroxyl orientation (clockwise or counter-cl...

  16. Mechanistic Study of Human Glucose Transport Mediated by GLUT1.

    PubMed

    Fu, Xuegang; Zhang, Gang; Liu, Ran; Wei, Jing; Zhang-Negrerie, Daisy; Jian, Xiaodong; Gao, Qingzhi

    2016-03-28

    The glucose transporter 1 (GLUT1) belongs to the major facilitator superfamily (MFS) and is responsible for the constant uptake of glucose. However, the molecular mechanism of sugar transport remains obscure. In this study, homology modeling and molecular dynamics (MD) simulations in lipid bilayers were performed to investigate the combination of the alternate and multisite transport mechanism of glucose with GLUT1 in atomic detail. To explore the substrate recognition mechanism, the outward-open state human GLUT1 homology model was generated based on the template of xylose transporter XylE (PDB ID: 4GBZ), which shares up to 29% sequence identity and 49% similarity with GLUT1. Through the MD simulation study of glucose across lipid bilayer with both the outward-open GLUT1 and the GLUT1 inward-open crystal structure, we investigated six different conformational states and identified four key binding sites in both exofacial and endofacial loops that are essential for glucose recognition and transport. The study further revealed that four flexible gates consisting of W65/Y292/Y293-M420/TM10b-W388 might play important roles in the transport cycle. The study showed that some side chains close to the central ligand binding site underwent larger position changes. These conformational interchanges formed gated networks within an S-shaped central channel that permitted staged ligand diffusion across the transporter. This study provides new inroads for the understanding of GLUT1 ligand recognition paradigm and configurational features which are important for molecular, structural, and physiological research of the MFS members, especially for GLUT1-targeted drug design and discovery.

  17. Restricted feeding phase shifts clock gene and sodium glucose cotransporter 1 (SGLT1) expression in rats.

    PubMed

    Balakrishnan, Anita; Stearns, Adam T; Ashley, Stanley W; Tavakkolizadeh, Ali; Rhoads, David B

    2010-05-01

    The intestine exhibits striking diurnal rhythmicity in glucose uptake, mediated by the sodium glucose cotransporter (SGLT1); however, regulatory pathways for these rhythms remain incompletely characterized. We hypothesized that SGLT1 rhythmicity is linked to the circadian clock. To investigate this, we examined rhythmicity of Sglt1 and individual clock genes in rats that consumed food ad libitum (AL). We further compared phase shifts of Sglt1 and clock genes in a second group of rats following restricted feeding to either the dark (DF) or light (LF) phase. Rats fed during the DF were pair-fed to rats fed during the LF. Jejunal mucosa was harvested across the diurnal period to generate expression profiles of Sglt1 and clock genes Clock, Bmal1 (brain-muscle Arnt-like 1), ReverbA/B, Per(Period) 1/2, and Cry (Cryptochrome) 1/2. All clock genes were rhythmic in AL rats (P < 0.05). Sglt1 also exhibited diurnal rhythmicity, with peak expression preceding nutrient arrival (P < 0.05). Light-restricted feeding shifted the expression rhythms of Sglt1 and most clock genes (Bmal1, ReverbA and B, Per1, Per2, and Cry1) compared with dark-restricted feeding (P < 0.05). The Sglt1 rhythm shifted in parallel with rhythms of Per1 and ReverbB. These effects of restricted feeding highlight luminal nutrients as a key Zeitgeber in the intestine, capable of simultaneously shifting the phases of transporter and clock gene expression, and suggest a role for clock genes in regulating Sglt1 and therefore glucose uptake. Understanding the regulatory cues governing rhythms in intestinal function may allow new therapeutic options for conditions of dysregulated absorption such as diabetes and obesity.

  18. 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.

  19. Effect of Peripheral Electrical Stimulation (PES) on Nocturnal Blood Glucose in Type 2 Diabetes: A Randomized Crossover Pilot Study

    PubMed Central

    Catalogna, Merav; Doenyas-Barak, Keren; Sagi, Roi; Abu-Hamad, Ramzia; Nevo, Uri; Efrati, Shai

    2016-01-01

    Background Regulation of hepatic glucose production has been a target for antidiabetic drug development, due to its major contribution to glucose homeostasis. Previous pre-clinical study demonstrated that peripheral electrical stimulation (PES) may stimulate glucose utilization and improve hepatic insulin sensitivity. The aim of the present study was to evaluate safety, tolerability, and the glucose-lowering effect of this approach in patients with type 2 diabetes (T2DM). Methods Twelve patients with T2DM were recruited for an open label, interventional, randomized trial. Eleven patients underwent, in a crossover design, an active, and a no-intervention control periods, separated with a two-week washout phase. During the active period, the patients received a daily lower extremity PES treatment (1.33Hz/16Hz burst mode), for 14 days. Study endpoints included changes in glucose levels, number of hypoglycemic episodes, and other potential side effects. Endpoints were analyzed based on continuous glucose meter readings, and laboratory evaluation. Results We found that during the active period, the most significant effect was on nocturnal glucose control (P < 0.0004), as well as on pre-meal mean glucose levels (P < 0.02). The mean daily glucose levels were also decreased although it did not reach clinical significance (P = 0.07). A reduction in serum cortisol (P < 0.01) but not in insulin was also detected after 2 weeks of treatment. No adverse events were recorded. Conclusions These results indicate that repeated PES treatment, even for a very short duration, can improve blood glucose control, possibly by suppressing hepatic glucose production. This effect may be mediated via hypothalamic-pituitary-adrenal axis modulation. Trial registration ClinicalTrials.gov NCT02727790 PMID:27997608

  20. Simulation of oral glucose tolerance tests and the corresponding isoglycemic intravenous glucose infusion studies for calculation of the incretin effect.

    PubMed

    Kim, Myeungseon; Oh, Tae Jung; Lee, Jung Chan; Choi, Karam; Kim, Min Young; Kim, Hee Chan; Cho, Young Min; Kim, Sungwan

    2014-03-01

    The incretin effect, which is a unique stimulus of insulin secretion in response to oral ingestion of nutrients, is calculated by the difference in insulin secretory responses from an oral glucose tolerance test (OGTT) and a corresponding isoglycemic intravenous glucose infusion (IIGI) study. The OGTT model of this study, which is individualized by fitting the glucose profiles during an OGTT, was developed to predict the glucose profile during an IIGI study in the same subject. Also, the model predicts the insulin and incretin profiles during both studies. The incretin effect, estimated by simulation, was compared with that measured by physiologic studies from eight human subjects with normal glucose tolerance, and the result exhibited a good correlation (r > 0.8); the incretin effect from the simulation was 56.5% ± 10.6% while the one from the measured data was 52.5% ± 19.6%. In conclusion, the parameters of the OGTT model have been successfully estimated to predict the profiles of both OGTTs and IIGI studies. Therefore, with glucose data from the OGTT alone, this model could control and predict the physiologic responses, including insulin secretion during OGTTs and IIGI studies, which could eventually eliminate the need for complex and cumbersome IIGI studies in incretin research.

  1. Study of glucose uptake activity of Helicteres isora Linn. fruits in L-6 cell lines

    PubMed Central

    Gupta, R. N.; Pareek, Anil; Suthar, Manish; Rathore, Garvendra S.; Basniwal, Pawan K.; Jain, Deepti

    2009-01-01

    The effect of hot water extract of fruits of Helicteres isora on glucose uptake was studied in rodent skeletal muscle cells (L-6 cells) involved in glucose utilization. H. isora is an antidiabetic medicinal plant being used in Indian traditional medicine. Hot water extracts were analysed for glucose uptake activity and found to be significantly active at 200 μg/ml dose comparable with insulin and metformin. Elevation of glucose uptake by H. isora in association with glucose transport supported the upregulation of glucose uptake. It was concluded that hot water extract of H. isora activate glucose uptake in L-6 cell line of mouse skeletal muscles. PMID:20336200

  2. Study of glucose uptake activity of Helicteres isora Linn. fruits in L-6 cell lines.

    PubMed

    Gupta, R N; Pareek, Anil; Suthar, Manish; Rathore, Garvendra S; Basniwal, Pawan K; Jain, Deepti

    2009-10-01

    The effect of hot water extract of fruits of Helicteres isora on glucose uptake was studied in rodent skeletal muscle cells (L-6 cells) involved in glucose utilization. H. isora is an antidiabetic medicinal plant being used in Indian traditional medicine. Hot water extracts were analysed for glucose uptake activity and found to be significantly active at 200 mug/ml dose comparable with insulin and metformin. Elevation of glucose uptake by H. isora in association with glucose transport supported the upregulation of glucose uptake. It was concluded that hot water extract of H. isora activate glucose uptake in L-6 cell line of mouse skeletal muscles.

  3. Studies on Electrical behavior of Glucose using Impedance Spectroscopy

    NASA Astrophysics Data System (ADS)

    Juansah, Jajang; Yulianti, Wina

    2016-01-01

    In this work we report the electrical characteristics of glucose at different frequencies. We show the correlation between electrical properties (impedance, reactance, resistance and conductance) of glucose and glucose concentration. Electrical property measurements on glucose solution were performed in order to formulate the correlation. The measurements were conducted for frequencies between 50 Hz and 1 MHz. From the measurements, we developed a single-pole Cole-Cole graph as a function of glucose concentration.

  4. Insulin sensitivity and first-phase insulin secretion in obese Chinese with hyperglycemia in 30 and/or 60 min during glucose tolerance tests.

    PubMed

    Hong, Jie; Zhang, Yi-Fei; Gu, Wei-qiong; Zhang, Yu-wen; Su, Yu-xia; Chi, Zhen-ni; Wang, Wei-qing; Li, Xiao-ying; Ning, Guang

    2008-01-01

    The purpose of this study was to investigate insulin sensitivity and first-phase insulin secretion in obesity with hyperglycemia in 30 and/or 60 min during oral glucose tolerance (OGTT, glucose > or = 11.1 mmol/l, post-loading hyperglycemia, PLH) in Chinese population. A total of 196 nondiabetic subjects were included in the present study, among them 99 had normal glucose tolerance (NGT, subdivided into 32 lean NGT and 67 obese NGT), 74 had obesity with impaired glucose tolerance (IGT) and 23 had obesity with PLH. A standard 75-g oral glucose tolerance test was performed after fasting and at 30 min, 1, 2 and 3 h. Insulin sensitivity index (S(I)) was assessed by the Bergman's minimal model method with frequently sampled intravenous glucose tolerance test (FSIGTT), insulin secretion was determined by acute insulin response to glucose (AIRg). The disposition index (DI), the product of AIRg and S(I) was used to determine whether AIRg was adequate to compensate for insulin resistance. S(I) was significantly equally lower in three obese subgroups. AIRg was significantly increased in obese NGT as compared with lean NGT controls, and reduced to the same extent in IGT and PLH subjects. There was no significant difference among lean NGT, IGT and PLH subjects. DI value was reduced from obese NGT individuals, IGT and PLH subjects had a similar lower level of DI. In conclusion, our present results demonstrated that the pathophysiological basis of obese subjects with PLH were clearly insulin resistance and defective in first-phase insulin secretion as that in IGT subjects in Chinese population.

  5. Glucose triggers ATP secretion from bacteria in a growth-phase-dependent manner.

    PubMed

    Hironaka, Ippei; Iwase, Tadayuki; Sugimoto, Shinya; Okuda, Ken-ichi; Tajima, Akiko; Yanaga, Katsuhiko; Mizunoe, Yoshimitsu

    2013-04-01

    ATP modulates immune cell functions, and ATP derived from gut commensal bacteria promotes the differentiation of T helper 17 (Th17) cells in the intestinal lamina propria. We recently reported that Enterococcus gallinarum, isolated from mice and humans, secretes ATP. We have since found and characterized several ATP-secreting bacteria. Of the tested enterococci, Enterococcus mundtii secreted the greatest amount of ATP (>2 μM/10(8) cells) after overnight culture. Glucose, not amino acids and vitamins, was essential for ATP secretion from E. mundtii. Analyses of energy-deprived cells demonstrated that glycolysis is the most important pathway for bacterial ATP secretion. Furthermore, exponential-phase E. mundtii and Enterococcus faecalis cells secrete ATP more efficiently than stationary-phase cells. Other bacteria, including Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus, also secrete ATP in exponential but not stationary phase. These results suggest that various gut bacteria, including commensals and pathogens, might secrete ATP at any growth phase and modulate immune cell function.

  6. No effect of menstrual cycle phase on glucose kinetics and fuel oxidation during moderate-intensity exercise

    PubMed Central

    HORTON, TRACY J.; MILLER, EMILY K.; GLUECK, DEBORAH; TENCH, KATHLEEN

    2009-01-01

    Resting and exercise fuel metabolism was assessed in three different phases of the menstrual cycle, characterized by different levels of estrogen relative to progesterone: early follicular (EF, low estrogen and progesterone), midfollicular (MF, elevated estrogen, low progesterone), and midluteal (ML, elevated estrogen and progesterone). It was hypothesized that exercise glucose utilization and whole body carbohydrate oxidation would decrease sequentially from the EF to the MF to the ML phase. Normal-weight healthy females, experiencing a regular menstrual cycle, were recruited. Subjects were moderately active but not highly trained. Testing occurred after 3 days of diet control and after an overnight fast (12-13 h). Resting (2 h) and exercise (50% maximal O2 uptake, 90 min) measurements of whole body substrate oxidation, tracer-determined glucose flux, and substrate and hormone concentrations were made. No significant difference was observed in whole body fuel oxidation during exercise in the three phases (nonprotein respiratory exchange ratio: EF 0.84 ± 0.01, MF 0.85 ± 0.01, ML 0.85 ± 0.01) or in rates of glucose appearance or disappearance. There were, however, significantly higher glucose (P < 0.05) and insulin (P < 0.001) concentrations during the first 45 min of exercise in the ML phase vs. EF and MF phases. In conclusion, whole body substrate oxidation and glucose utilization did not vary significantly across the menstrual cycle in moderately active women, either at rest or during 90 min of moderate-intensity exercise. During the ML phase, however, this similar pattern of substrate utilization was associated with greater glucose and insulin concentrations. Both estrogen and progesterone are elevated during the ML phase of the menstrual cycle, suggesting that one or both of these sex steroids may play a role in this response. PMID:11882494

  7. Options Study - Phase II

    SciTech Connect

    R. Wigeland; T. Taiwo; M. Todosow; W. Halsey; J. Gehin

    2010-09-01

    The Options Study has been conducted for the purpose of evaluating the potential of alternative integrated nuclear fuel cycle options to favorably address the issues associated with a continuing or expanding use of nuclear power in the United States. The study produced information that can be used to inform decisions identifying potential directions for research and development on such fuel cycle options. An integrated nuclear fuel cycle option is defined in this study as including all aspects of the entire nuclear fuel cycle, from obtaining natural resources for fuel to the ultimate disposal of used nuclear fuel (UNF) or radioactive wastes. Issues such as nuclear waste management, especially the increasing inventory of used nuclear fuel, the current uncertainty about used fuel disposal, and the risk of nuclear weapons proliferation have contributed to the reluctance to expand the use of nuclear power, even though it is recognized that nuclear power is a safe and reliable method of producing electricity. In this Options Study, current, evolutionary, and revolutionary nuclear energy options were all considered, including the use of uranium and thorium, and both once-through and recycle approaches. Available information has been collected and reviewed in order to evaluate the ability of an option to clearly address the challenges associated with the current implementation and potential expansion of commercial nuclear power in the United States. This Options Study is a comprehensive consideration and review of fuel cycle and technology options, including those for disposal, and is not constrained by any limitations that may be imposed by economics, technical maturity, past policy, or speculated future conditions. This Phase II report is intended to be used in conjunction with the Phase I report, and much information in that report is not repeated here, although some information has been updated to reflect recent developments. The focus in this Options Study was to

  8. Iron, Glucose and Intrinsic Factors Alter Sphingolipid Composition as Yeast Cells Enter Stationary Phase

    PubMed Central

    Lester, Robert L.; Withers, Bradley R.; Schultz, Megan A.; Dickson, Robert C.

    2013-01-01

    Survival of Saccharomyces cerevisiae cells, like most microorganisms, requires switching from a rapidly dividing to a non-dividing or stationary state. To further understand how cells navigate this switch, we examined sphingolipids since they are key structural elements of membranes and also regulate signaling pathways vital for survival. During and after the switch to a non-dividing state there is a large increase in total free and sphingolipid-bound long chain-bases and an even larger increase in free and bound C20-long-chain bases, which are nearly undetectable in dividing cells. These changes are due to intrinsic factors including Orm1 and Orm2, ceramide synthase, Lcb4 kinase and the Tsc3 subunit of serine palmitoyltransferase as well as extrinsic factors including glucose and iron. Lowering the concentration of glucose, a form of calorie restriction, decreases the level of LCBs, which is consistent with the idea that reducing the level of some sphingolipids enhances lifespan. In contrast, iron deprivation increases LCB levels and decreases long term survival; however, these phenomena may not be related because iron deprivation disrupts many metabolic pathways. The correlation between increased LCBs and shorter lifespan is unsupported at this time. The physiological rise in LCBs that we observe may serve to modulate nutrient transporters and possibly other membrane phenomena that contribute to enhanced stress resistance and survival in stationary phase. PMID:23286903

  9. Kinetics studies of d-glucose hydrogenation over activated charcoal supported platinum catalyst

    NASA Astrophysics Data System (ADS)

    Ahmed, Muthanna J.

    2012-02-01

    The kinetics of the catalytic hydrogenation of d-glucose to produce d-sorbitol was studied in a three-phase laboratory scale reactor. The hydrogenation reactions were performed on activated charcoal supported platinum catalyst in the temperature range 25-65°C and in a constant pressure of 1 atm. The kinetic data were modeled by zero, first and second-order reaction equations. In the operating regimes studied, the results show that the hydrogenation reaction was of a first order with respect to d-glucose concentration. Also the activation energy of the reaction was determined, and found to be 12.33 kJ mole-1. A set of experiment was carried out to test the deactivation of the catalyst, and the results show that the deactivation is slow with the ability of using the catalyst for several times with a small decrease in product yield.

  10. Interstitial Fluid Glucose Is Not Just a Shifted-in-Time but a Distorted Mirror of Blood Glucose: Insight from an In Silico Study

    PubMed Central

    Schiavon, Michele; Dalla Man, Chiara; Basu, Ananda; Basu, Rita

    2016-01-01

    Abstract Background: Glucose sensors measure glucose concentration in the interstitial fluid (ISF), remote from blood. ISF glucose is well known to be “delayed” with respect to blood glucose (BG). However, ISF glucose is not simply a shifted-in-time version of BG but exhibits a more complex pattern. Methods: To gain insight into this problem, one can use linear systems theory. However, this may lose a more clinical readership, thus we use simulation and two case studies to convey our thinking in an easier way. In particular, we consider BG concentration measured after meal and exercise in 12 healthy volunteers, whereas ISF glucose is simulated using a well-accepted model of blood–ISF glucose kinetics, which permits calculation of the equilibration time, a parameter characterizing the system. Two metrics are defined: blood and ISF glucose difference at each time point and time to reach the same glucose value in blood and ISF. Results: The simulation performed and the two metrics show that the relationship between blood–ISF glucose profiles is more complex than a pure shift in time and that the pattern depends on both equilibration time and BG. Conclusions: In this in silico study, we have illustrated, with simple case studies, the meaning of the of ISF glucose with respect to BG. Understanding that ISF glucose is not just a shifted-in-time version but a distorted mirror of BG is important for a correct use of continuous glucose monitoring for diabetes management. PMID:27253751

  11. Molecular Dynamic Studies of the Complex Polyethylenimine and Glucose Oxidase

    PubMed Central

    Szefler, Beata; Diudea, Mircea V.; Putz, Mihai V.; Grudzinski, Ireneusz P.

    2016-01-01

    Glucose oxidase (GOx) is an enzyme produced by Aspergillus, Penicillium and other fungi species. It catalyzes the oxidation of β-d-glucose (by the molecular oxygen or other molecules, like quinones, in a higher oxidation state) to form d-glucono-1,5-lactone, which hydrolyses spontaneously to produce gluconic acid. A coproduct of this enzymatic reaction is hydrogen peroxide (H2O2). GOx has found several commercial applications in chemical and pharmaceutical industries including novel biosensors that use the immobilized enzyme on different nanomaterials and/or polymers such as polyethylenimine (PEI). The problem of GOx immobilization on PEI is retaining the enzyme native activity despite its immobilization onto the polymer surface. Therefore, the molecular dynamic (MD) study of the PEI ligand (C14N8_07_B22) and the GOx enzyme (3QVR) was performed to examine the final complex PEI-GOx stabilization and the affinity of the PEI ligand to the docking sites of the GOx enzyme. The docking procedure showed two places/regions of major interaction of the protein with the polymer PEI: (LIG1) of −5.8 kcal/mol and (LIG2) of −4.5 kcal/mol located inside the enzyme and on its surface, respectively. The values of enthalpy for the PEI-enzyme complex, located inside of the protein (LIG1) and on its surface (LIG2) were computed. Docking also discovered domains of the GOx protein that exhibit no interactions with the ligand or have even repulsive characteristics. The structural data clearly indicate some differences in the ligand PEI behavior bound at the two places/regions of glucose oxidase. PMID:27801788

  12. Molecular Dynamic Studies of the Complex Polyethylenimine and Glucose Oxidase.

    PubMed

    Szefler, Beata; Diudea, Mircea V; Putz, Mihai V; Grudzinski, Ireneusz P

    2016-10-27

    Glucose oxidase (GOx) is an enzyme produced by Aspergillus, Penicillium and other fungi species. It catalyzes the oxidation of β-d-glucose (by the molecular oxygen or other molecules, like quinones, in a higher oxidation state) to form d-glucono-1,5-lactone, which hydrolyses spontaneously to produce gluconic acid. A coproduct of this enzymatic reaction is hydrogen peroxide (H₂O₂). GOx has found several commercial applications in chemical and pharmaceutical industries including novel biosensors that use the immobilized enzyme on different nanomaterials and/or polymers such as polyethylenimine (PEI). The problem of GOx immobilization on PEI is retaining the enzyme native activity despite its immobilization onto the polymer surface. Therefore, the molecular dynamic (MD) study of the PEI ligand (C14N8_07_B22) and the GOx enzyme (3QVR) was performed to examine the final complex PEI-GOx stabilization and the affinity of the PEI ligand to the docking sites of the GOx enzyme. The docking procedure showed two places/regions of major interaction of the protein with the polymer PEI: (LIG1) of -5.8 kcal/mol and (LIG2) of -4.5 kcal/mol located inside the enzyme and on its surface, respectively. The values of enthalpy for the PEI-enzyme complex, located inside of the protein (LIG1) and on its surface (LIG2) were computed. Docking also discovered domains of the GOx protein that exhibit no interactions with the ligand or have even repulsive characteristics. The structural data clearly indicate some differences in the ligand PEI behavior bound at the two places/regions of glucose oxidase.

  13. Studies of glucose turnover and renal function in an unusual case of hereditary fructose intolerance.

    PubMed

    Steiner, G; Wilson, D; Vranic, M

    1977-01-01

    Examination of glucose kinetics, pancreatic alpha and beta cell function, plasma lipids, urinary acidification and calcium excretion has been undertaken in a patient with hereditary fructose intolerance. This case was unusual as it was associated with insulin-requiring diabetes, type IV hyperlipemia, hypercalciuria and renal calculi. He also demonstrated the previously described fructose-induced defect of urine acidification. Glucagon and C-peptide assays showed that the pancreatic alpha cells were stimulated by fructose and that the beta cells did not respond to fructose. It is not known whether the latter was due to his diabetes or to the lack of a beta cell response to this sugar. Primed 14C-glucose infusions were used for the first time to study nonsteady state glucose kinetics in man. They showed that, 24 hours after the last insulin injection and under basal conditions, the glucose concentrations increased because glucose production exceeded glucose utilization. However, after the administration of sorbitol the plasma glucose concentration decreased because glucose production decreased. After the administration of sorbitol there was no change in the metabolic clearance of glucose. This reflects the lack of a peripheral insulin effect and is consistent with the lack of any measurable C-peptide. Glucose utilization also decreased, but this decrease was less than the decrease in glucose production. Because the metabolic clearance of glucose remained unchanged, it was concluded that the change in glucose utilization was solely due to the decrease in glucose concentration. The absence of C-peptide in the plasma indicated that changes in glucose turnover were not related to any changes in endogenous plasma insulin. Furthermore, the plasma glucagon concentration increased and, hence, changes in this hormone could not account for the decrease in glucose production. Therefore, it was concluded that the sorbitol-induced decline in glucose production was due to a direct

  14. Influence of cholesterol on non-invasive blood glucose sensing studied with NIR spectroscopy

    NASA Astrophysics Data System (ADS)

    Jiang, Jingying; Zhang, Lingling; Gong, Qiliang; Xu, Kexin

    2011-03-01

    There is a growing body of studies suggesting that NIR spectroscopy is feasible to be used to non-invasive blood glucose sensing. However, previous results reported that blood components are very complicated and in which glucose concentration is relatively low. This feature limited the practical application of NIR spectroscopy to in vivo blood glucose detection. This talk aims to elucidate how the cholesterol influences blood glucose sensing. Spectroscopic measurements show that cholesterol appears the similar absorbance peaks to those of glucose within NIR range. Furthermore, PLS modelling results demonstrate that the measurement concentrations of glucose are on the high side while containing cholesterol. For example, when the cholesterol concentration is 200mg/dl, the measurement result of glucose with near-infrared spectroscopy will increase 7.961882mg/dl comparing to cholesterol-free glucose solution. Therefore, it is necessary to take steps to reduce cholesterol's effects.

  15. A high performance three-phase enzyme electrode based on superhydrophobic mesoporous silicon nanowire arrays for glucose detection.

    PubMed

    Xu, Chenlong; Song, Zhiqian; Xiang, Qun; Jin, Jian; Feng, Xinjian

    2016-04-14

    We describe here a high performance oxygen-rich three-phase enzyme electrode based on superhydrophobic mesoporous silicon nanowire arrays for glucose detection. We demonstrate that its linear detection upper limit is 30 mM, more than 15 times higher than that can be obtained on the normal enzyme-electrode. Notably, the three-phase enzyme electrode output is insensitive to the significant oxygen level fluctuation in analyte solution.

  16. Study of dynamics of glucose-glucose oxidase-ferricyanide reaction

    NASA Astrophysics Data System (ADS)

    Nováková, A.; Schreiberová, L.; Schreiber, I.

    2011-12-01

    This work is focused on dynamics of the glucose-glucose oxidase-ferricyanide enzymatic reaction with or without sodium hydroxide in a continuous-flow stirred tank reactor (CSTR) and in a batch reactor. This reaction exhibits pH-variations having autocatalytic character and is reported to provide nonlinear dynamic behavior (bistability, excitability). The dynamical behavior of the reaction was examined within a wide range of inlet parameters. The main inlet parameters were the ratio of concentrations of sodium hydroxide and ferricyanide and the flow rate. In a batch reactor we observed an autocatalytic drop of pH from slightly basic to medium acidic values. In a CSTR our aim was to find bistability in the presence of sodium hydroxide. However, only a basic steady state was found. In order to reach an acidic steady state, we investigated the system in the absence of sodium hydroxide. Under these conditions the transition from the basic to the acidic steady state was observed when inlet glucose concentration was increased.

  17. Is Type 2 Diabetes Really Resolved after Laparoscopic Sleeve Gastrectomy? Glucose Variability Studied by Continuous Glucose Monitoring

    PubMed Central

    Capoccia, D.; Coccia, F.; Guida, A.; Rizzello, M.; De Angelis, F.; Silecchia, G.; Leonetti, F.

    2015-01-01

    The study was carried out on type 2 diabetic obese patients who underwent laparoscopic sleeve gastrectomy (LSG). Patients underwent regular glycemic controls throughout 3 years and all patients were defined cured from diabetes according to conventional criteria defined as normalization of fasting glucose levels and glycated hemoglobin in absence of antidiabetic therapy. After 3 years of follow-up, Continuous Glucose Monitoring (CGM) was performed in each patient to better clarify the remission of diabetes. In this study, we found that the diabetes resolution after LSG occurred in 40% of patients; in the other 60%, even if they showed a normal fasting glycemia and A1c, patients spent a lot of time in hyperglycemia. During the oral glucose tolerance test (OGTT), we found that 2 h postload glucose determinations revealed overt diabetes only in a small group of patients and might be insufficient to exclude the diagnosis of diabetes in the other patients who spent a lot of time in hyperglycemia, even if they showed a normal glycemia (<140 mg/dL) at 120 minutes OGTT. These interesting data could help clinicians to better individualize patients in which diabetes is not resolved and who could need more attention in order to prevent chronic complications of diabetes. PMID:25954762

  18. High prevalence of undiagnosed diabetes and abnormal glucose tolerance in the Iranian urban population: Tehran Lipid and Glucose Study

    PubMed Central

    Hadaegh, Farzad; Bozorgmanesh, Mohammad Reza; Ghasemi, Asghar; Harati, Hadi; Saadat, Navid; Azizi, Fereidoun

    2008-01-01

    Background To estimate the prevalence of diagnosed and undiagnosed diabetes mellitus, impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and combined IFG/IGT in a large urban Iranian population aged ≥ 20 years. Methods The study population included 9,489 participants of the Tehran Lipid and Glucose Study with full relevant clinical data. Age-standardized prevalence of diabetes and glucose intolerance categories were reported according to the 2003 American Diabetes Association definitions. Age-adjusted logistic regression models were used to estimate the numbers needed to screen (NNTS) to find one person with undiagnosed diabetes. Results The prevalence of diagnosed and undiagnosed diabetes, isolated IFG, isolated IGT, and combined IFG/IGT were 8.1%, 5.1%, 8.7%, 5.4% and 4.0% in men and 10%, 4.7%, 6.3%, 7.6%, and 4.5% in women respectively. Participants with undiagnosed diabetes had higher age, body mass index (BMI), waist circumference, systolic and diastolic blood pressures, triglycerides (all p values <0.001) and lower HDL-cholesterol (only in women, p < 0.01) compared to normoglycemic subjects. Undiagnosed diabetes was associated with family history of diabetes, increased BMI (≥ 25 kg/m2), abdominal obesity, hypertriglyceridemia, hypertension and low HDL-cholesterol levels. Among men, a combination of increased BMI, hypertension, and family history of diabetes led to a NNTS of 1.6 (95% CI: 1.57–1.71) and among women a combination of family history of diabetes and abdominal obesity, yielded a NNTS of 2.2 (95% CI: 2.1–2.4). Conclusion In conclusion, about one third of Tehranian adults had disturbed glucose tolerance or diabetes. One- third of total cases with diabetes were undiagnosed. Screening individuals with BMI ≥ 25 kg/m2 (men), hypertension (men), abdominal obesity (women) and family history of diabetes may be more efficient. PMID:18501007

  19. Optical coherence tomography technique for noninvasive blood glucose monitoring: phantom, animal, and human studies

    NASA Astrophysics Data System (ADS)

    Larin, Kirill V.; Ashitkov, Taras V.; Larina, Irina V.; Petrova, Irina Y.; Eledrisi, Mohsen S.; Motamedi, Massoud; Esenaliev, Rinat O.

    2002-06-01

    Continuous noninvasive monitoring of blood glucose concentration can improve management of Diabetes Mellitus, reduce mortality, and considerably improve quality of life of diabetic patients. Recently, we proposed to use the OCT technique for noninvasive glucose monitoring. In this paper, we tested noninvasive blood glucose monitoring with the OCT technique in phantoms, animals, and human subjects. An OCT system with the wavelength of 1300 nm was used in our experiments. Phantom studies performed on aqueous suspensions of polystyrene microspheres and milk showed 3.2% decrease of exponential slope of OCT signals when glucose concentration increased from 0 to 100 mM. Theoretical calculations based on the Mie theory of scattering support the results obtained in phantoms. Bolus glucose injections and glucose clamping experiments were performed in animals (New Zealand rabbits and Yucatan micropigs). Good correlation between changes in the OCT signal slope and actual blood glucose concentration were observed in these experiments. First studies were performed in healthy human subjects (using oral glucose tolerance tests). Dependence of the slope of the OCT signals on the actual blood glucose concentration was similar to that obtained in animal studies. Our studies suggest that the OCT technique can potentially be used for noninvasive blood glucose monitoring.

  20. Distributed phased array architecture study

    NASA Technical Reports Server (NTRS)

    Bourgeois, Brian

    1987-01-01

    Variations in amplifiers and phase shifters can cause degraded antenna performance, depending also on the environmental conditions and antenna array architecture. The implementation of distributed phased array hardware was studied with the aid of the DISTAR computer program as a simulation tool. This simulation provides guidance in hardware simulation. Both hard and soft failures of the amplifiers in the T/R modules are modeled. Hard failures are catastrophic: no power is transmitted to the antenna elements. Noncatastrophic or soft failures are modeled as a modified Gaussian distribution. The resulting amplitude characteristics then determine the array excitation coefficients. The phase characteristics take on a uniform distribution. Pattern characteristics such as antenna gain, half power beamwidth, mainbeam phase errors, sidelobe levels, and beam pointing errors were studied as functions of amplifier and phase shifter variations. General specifications for amplifier and phase shifter tolerances in various architecture configurations for C band and S band were determined.

  1. Noninvasive Polarimetric-Based Glucose Monitoring: An in Vivo Study

    PubMed Central

    Purvinis, Georgeanne; Cameron, Brent D; Altrogge, Douglas M

    2011-01-01

    Background: Since 1990, there has been significant research devoted toward development of a noninvasive physiological glucose sensor. In this article, we report on the use of optical polarimetry for the noninvasive measurement of physiological glucose concentration in the anterior chamber of the eye of New Zealand white (NZW) rabbits. Method: Measurements were acquired using a custom-designed laser-based optical polarimetry system in a total of seven NZW rabbits anesthetized using an isoflurane-only anesthesia protocol. Aqueous humor-based polarimetric measurements were obtained by coupling light through the anterior chamber of the eye. Blood glucose levels were first stabilized and then altered with intravenous dextrose and insulin administration and measured every 3–5 min with a standard glucometer and intermittently with a YSI 2300 glucose analyzer. Acquired polarimetric glucose signals are calibrated to measured blood glucose concentration. Results: Based on a total of 41 data points, Clarke error grid analysis indicated 93% in zone A, 7% in zone B, and 0% in zones C and D, with reference concentrations between 93 and 521 mg/dl. Errors in prediction are shown to be related to gross movement of the rabbit during the procedures, incurring time-varying corneal birefringence effects that directly affect the measured polarimetric signal. These effects can be compensated for with appropriate design modifications. Conclusions: An optical polarimetry technique was used for in vivo physiological glucose monitoring. The technique demonstrated provides a basis for the development of a noninvasive polarimetric glucose monitor for home, personal, or hospital use. PMID:21527109

  2. Correlation of salivary glucose, blood glucose and oral candidal carriage in the saliva of type 2 diabetics: A case-control study

    PubMed Central

    Kumar, Satish; Padmashree, S.; Jayalekshmi, Rema

    2014-01-01

    Objectives: To study the correlation between blood glucose levels and salivary glucose levels in type 2 diabetic patients, to study the relationship between salivary glucose levels and oral candidal carriage in type 2 diabetic patients and to determine whether salivary glucose levels could be used as a noninvasive tool for the measurement of glycemic control in type 2 diabetics. Study Design: The study population consisted of three groups: Group 1 consisted of 30 controlled diabetics and Group 2 consisted of 30 uncontrolled diabetics based on their random nonfasting plasma glucose levels. Group 3 consisted of 30 healthy controls. Two milliliters of peripheral blood was collected for the estimation of random nonfasting plasma glucose levels and glycosylated hemoglobin (HbA1c). Unstimulated saliva was collected for the estimation of salivary glucose. Saliva was collected by the oral rinse technique for the estimation of candidal counts. Results: The salivary glucose levels were significantly higher in controlled and uncontrolled diabetics when compared with controls. The salivary candidal carriage was also significantly higher in uncontrolled diabetics when compared with controlled diabetics and nondiabetic controls. The salivary glucose levels showed a significant correlation with blood glucose levels, suggesting that salivary glucose levels can be used as a monitoring tool for predicting glycemic control in diabetic patients. Conclusion: The present study found that estimation of salivary glucose levels can be used as a noninvasive, painless technique for the measurement of diabetic status of a patient in a dental set up. Increased salivary glucose levels leads to increased oral candidal carriage; therefore, oral diagnosticians are advised to screen the diabetic patients for any oral fungal infections and further management. PMID:25191065

  3. The 13C/12C fractionation by microbial cells immobilized on a solid-phase carrier during the growth on glucose

    NASA Astrophysics Data System (ADS)

    Zyakun, Anatoly; Kochetkov, Vladimir

    2010-05-01

    Problem. In microbiological ecology, the level of basal СО2 respiration and the potential of microbial activity defined as substrate-induced respiration (SIR) are used as criteria of the metabolic state of soil microbiota. The peculiar feature of glucose metabolism in soil is its utilization by microbial cells immobilized on soil particles as a solid-phase carrier. The efficiency of substrate utilization and СО2 production in such cases depend on the rate of microorganisms' growth and colonization of the solid-phase carrier surface, where the substrate is located. The products of microbial metabolism are supposed to inherit the substrate isotope composition correct to the isotopic effects accompanying substrate utilization and metabolic transformations. However, all experiments in carbon isotope fractionation during microbial utilization of glucose as a substrate have been carried out with microorganisms growing in liquid media. Objective: Study of the kinetics of glucose utilization as a test substrate during the growth of soil microorganisms immobilized on a solid-phase carrier and ascertainment of peculiarities of the formation of carbon isotope composition of produced metabolic СО2. The objects of research were Pseudomonas aureofaciens BS1393(pBS216) (culture A) and Rhodococcus sp. 3-30 (culture B) as representatives of pseudomonades and rhodococci, which occur in the soils of different genesis and are of defining value in development and implementation of biotechnological schemes for degradation of toxic organic pollutants in the environment. Results and discussion. The cultures under study had different rates of growth on glucose. Specific rates of СО2 production during the growth of cultures A and B on glucose were 0.34 (± 0.05) and 0.078 (± 0.01) μg С-СО2 h-1, respectively. The lag periods of culture (A and B) growth were about 4.3 and 26 h, respectively. Comparison of the lag periods of these representatives of pseudomonades and rhodococci

  4. Glucose Variability

    PubMed Central

    Le Floch, Jean-Pierre; Kessler, Laurence

    2016-01-01

    Background: Glucose variability has been suspected to be a major factor of diabetic complications. Several indices have been proposed for measuring glucose variability, but their interest remains discussed. Our aim was to compare different indices. Methods: Glucose variability was studied in 150 insulin-treated diabetic patients (46% men, 42% type 1 diabetes, age 52 ± 11 years) using a continuous glucose monitoring system (668 ± 564 glucose values; mean glucose value 173 ± 38 mg/dL). Results from the mean, the median, different indices (SD, MAGE, MAG, glucose fluctuation index (GFI), and percentages of low [<60 mg/dL] and high [>180 mg/dL] glucose values), and ratios (CV = SD/m, MAGE/m, MAG/m, and GCF = GFI/m) were compared using Pearson linear correlations and a multivariate principal component analysis (PCA). Results: CV, MAGE/m (ns), GCF and GFI (P < .05), MAG and MAG/m (P < .01) were not strongly correlated with the mean. The percentage of high glucose values was mainly correlated with indices. The percentage of low glucose values was mainly correlated with ratios. PCA showed 3 main axes; the first was associated with descriptive data (mean, SD, CV, MAGE, MAGE/m, and percentage of high glucose values); the second with ratios MAG/m and GCF and with the percentage of low glucose values; and the third with MAG, GFI, and the percentage of high glucose values. Conclusions: Indices and ratios provide complementary pieces of information associated with high and low glucose values, respectively. The pairs MAG+MAG/m and GFI+GCF appear to be the most reliable markers of glucose variability in diabetic patients. PMID:26880391

  5. Phosphoinositide hydrolysis and insulin release from isolated perifused rat islets. Studies with glucose.

    PubMed

    Zawalich, W S; Zawalich, K C

    1988-09-01

    The ability of glucose to promote the hydrolysis of prelabeled [2-3H]inositol-containing phosphoinositides (PI) was assessed by measuring the efflux of 3H in response to glucose and the accumulation of labeled inositol phosphates. The inclusion of nonradioactive inositol (1 mM) in the perifusion medium dramatically improved our ability to monitor glucose-induced increases in 3H efflux. Efflux studies with this method revealed the following. 1) 3H efflux is significantly greater at 7 than at 2.75 mM glucose, and this parallels a small but significant increase in insulin secretion. 2) D-manno-Heptulose reduces 3H efflux with 7 mM glucose to a level approximating that seen in the presence of 2.75 mM glucose and has no effect on 3H efflux with 2.75 mM glucose. 3) In the presence of 20 mM glucose plus 1 mM inositol, 3H efflux is rapid and biphasic, a response that parallels the timing and amplitude of the biphasic pattern of insulin secretion. Direct measurements of labeled inositol and inositol phosphate levels in islets revealed the following. 4) After 50 min of perifusion with 2.75 or 7 mM glucose, labeled inositol phosphates were significantly greater with 7 mM glucose. 5) In response to 20 mM glucose alone, islet levels of free inositol, inositol monophosphate (IP1), and inositol bisphosphate (IP2) increased. 6) In response to 20 mM glucose plus 1 mM cold inositol, islet levels of free inositol increased, whereas islet levels of IP1, IP2, and inositol trisphosphate (IP3) were reduced compared with values obtained with 20 mM glucose alone.(ABSTRACT TRUNCATED AT 250 WORDS)

  6. Improvements in glucose tolerance with Bikram Yoga in older obese adults: a pilot study.

    PubMed

    Hunter, Stacy D; Dhindsa, Mandeep; Cunningham, Emily; Tarumi, Takashi; Alkatan, Mohammed; Tanaka, Hirofumi

    2013-10-01

    Bikram yoga is an exotic form of physical activity combining hatha yoga and thermal therapy that could positively impact metabolic health. Although this increasingly popular alternative exercise may be ideal for obese adults due to its low impact nature, few studies have elucidated the health benefits associated with it. As an initial step, we determined the effect of Bikram yoga on glucose tolerance. Fourteen young lean and 15 older obese subjects completed an 8-week Bikram yoga intervention in which classes were completed 3 times per week. Glucose tolerance was assessed using a 75 g oral glucose tolerance test. The area under the glucose curve following the oral glucose tolerance test was significantly reduced as a result of the Bikram Yoga intervention in older obese (P < 0.05) but not in young lean subjects. We concluded that a short-term Bikram yoga intervention improved glucose tolerance in older obese, but not in young lean adults.

  7. 77 FR 30016 - Clinical Study Design and Performance of Hospital Glucose Sensors

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-21

    ... Sensors AGENCY: Food and Drug Administration, HHS. ACTION: Notice of public meeting; request for comments... Study Design and Performance of Hospital Glucose Sensors.'' The purpose of this public meeting is to discuss clinical study design considerations and performance metrics for innovative glucose...

  8. Numerical Studies of Topological phases

    NASA Astrophysics Data System (ADS)

    Geraedts, Scott

    The topological phases of matter have been a major part of condensed matter physics research since the discovery of the quantum Hall effect in the 1980s. Recently, much of this research has focused on the study of systems of free fermions, such as the integer quantum Hall effect, quantum spin Hall effect, and topological insulator. Though these free fermion systems can play host to a variety of interesting phenomena, the physics of interacting topological phases is even richer. Unfortunately, there is a shortage of theoretical tools that can be used to approach interacting problems. In this thesis I will discuss progress in using two different numerical techniques to study topological phases. Recently much research in topological phases has focused on phases made up of bosons. Unlike fermions, free bosons form a condensate and so interactions are vital if the bosons are to realize a topological phase. Since these phases are difficult to study, much of our understanding comes from exactly solvable models, such as Kitaev's toric code, as well as Levin-Wen and Walker-Wang models. We may want to study systems for which such exactly solvable models are not available. In this thesis I present a series of models which are not solvable exactly, but which can be studied in sign-free Monte Carlo simulations. The models work by binding charges to point topological defects. They can be used to realize bosonic interacting versions of the quantum Hall effect in 2D and topological insulator in 3D. Effective field theories of ''integer'' (non-fractionalized) versions of these phases were available in the literature, but our models also allow for the construction of fractional phases. We can measure a number of properties of the bulk and surface of these phases. Few interacting topological phases have been realized experimentally, but there is one very important exception: the fractional quantum Hall effect (FQHE). Though the fractional quantum Hall effect we discovered over 30

  9. Two phase detonation studies

    NASA Technical Reports Server (NTRS)

    Nicholls, J. A.; Pierce, T. H.; Miyajima, H.; Oza, R.; Patil, P.

    1974-01-01

    An experimental study of the passage of a shock wave over a burning fuel drop is described. This includes high speed framing photographs of the interaction taken at 500,000 frames per second. A theoretical prediction of the ignition of a fuel drop by a shock wave is presented and the results compared with earlier experimental work. Experimental attempts to generate a detonation in a liquid fuel drop (kerosene)-liquid oxidizer drop (hydrogen peroxide)-inert gas-environment are described. An appendix is included which gives the analytical prediction of power requirements for the drop generator to produce certain size drops at a certain mass rate. A bibliography is also included which lists all of the publications resulting from this research grant.

  10. The interleukin-1 receptor antagonist anakinra improves first-phase insulin secretion and insulinogenic index in subjects with impaired glucose tolerance.

    PubMed

    van Poppel, P C M; van Asseldonk, E J P; Holst, J J; Vilsbøll, T; Netea, M G; Tack, C J

    2014-12-01

    Inflammation at the level of the β cell appears to be involved in progressive β-cell dysfunction in type 2 diabetes. We assessed the effect of blocking interleukin-1 (IL-1) by anakinra [recombinant human interleukin-1 receptor antagonist (IL-1Ra)] on β-cell function. Sixteen participants with impaired glucose tolerance were treated with 150 mg anakinra daily for 4 weeks in a double blind, randomized, placebo-controlled cross-over study with a wash-out period of 4 weeks. At the end of each treatment period, oral glucose tolerance tests (OGTTs) and hyperglycaemic clamps were performed. First-phase insulin secretion improved after anakinra treatment compared with placebo, 148 ± 20 versus 123 ± 14 mU/l, respectively (p = 0.03), and the insulinogenic index was higher after anakinra treatment. These results support the concept of involvement of IL-1β in the (progressive) decrease of insulin secretion capacity associated with type 2 diabetes.

  11. Effect of a glucose-triazole-hydrogenated cardanol conjugate on lipid bilayer membrane organization and thermotropic phase transition

    NASA Astrophysics Data System (ADS)

    Swain, Jitendriya; Kamalraj, M.; Surya Prakash Rao, H.; Mishra, Ashok K.

    2015-02-01

    This work focuses on the membrane perturbation, solubilisation and thermotropic phase transition process of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) MLVs induced by a glucose-triazole-hydrogenated cardanol conjugate (GTHCC). GTHCC is a recently introduced non toxic sugar derivative. Differential scanning calorimetry (DSC) and fluorescence molecular probe based techniques have been used to understand the concentration dependent membrane perturbation, solubilisation and thermotropic phase transition process of DPPC MLVs. The phase transition temperature of DPPC MLVs decreases with increase in mol% of GTHCC. At higher concentration above 10 mol%, GTHCC was significantly perturbed the membrane organization. The intrinsic fluorescence of GTHCC is also found to be sensitive towards phase behaviour and changes in membrane organization of DPPC MLVs.

  12. A critical period of brain development: studies of cerebral glucose utilization with PET.

    PubMed

    Chugani, H T

    1998-01-01

    Studies with positron emission tomography indicate that the human brain undergoes a period of postnatal maturation that is much more protracted than previously suspected. In the newborn, the highest degree of glucose metabolism (representative of functional activity) is in primary sensory and motor cortex, cingulate cortex, thalamus, brain stem, cerebellar vermis, and hippocampal region. At 2 to 3 months of age, glucose utilization increases in the parietal, temporal, and primary visual cortex; basal ganglia; and cerebellar hemispheres. Between 6 and 12 months, glucose utilization increases in frontal cortex. These metabolic changes correspond to the emergence of various behaviors during the first year of life. The measurement of absolute rates of glucose utilization during development indicates that the cerebral cortex undergoes a dynamic course of metabolic maturation that persists until ages 16-18 years. Initially, there is a rise in the rates of glucose utilization from birth until about age 4 years, at which time the child's cerebral cortex uses over twice as much glucose as that of adults. From age 4 to 10 years, these very high rates of glucose consumption are maintained, and only after then is there a gradual decline of glucose metabolic rates to reach adult values by age 16-18 years. Correlations between glucose utilization rates and synaptogenesis are discussed, and the argument is made that these findings have important implications with respect to human brain plasticity following injury as well as to "critical periods" of maximal learning capacity.

  13. [Specific features of studies of glucose in biological fluids (review)].

    PubMed

    Ruvinova, L G; Kirpich, I A; Sidorov, P I; Solov'ev, A G

    1996-01-01

    The review is devoted to the main questions of investigations of the main index of carbohydrate metabolism--glucose in biological liquids of an organism. Detailed analysis of technological principles and interpretation of biochemical results with due regard to the influence of the complex of inner and external physico-chemical, biological and climatic factors is presented.

  14. [Activation of the expression of the microcin C51 operon upon glucose starvation of cells at the exponential growth phase].

    PubMed

    Veselovskiĭ, A M; Metlitskaia, A Z; Lipasova, V A; Bass, I A; Khmel', I A

    2005-01-01

    It was earlier shown that expression of the microcin C51 operon in Escherichia coli cells is activated upon decelerated growth of cells during their transition to the stationary growth phase and depends on the sigmaS subunit of RNA polymerase. Using a single-copy construct containing the cloned promoter region of the microcin C51 operon and a promoterless lac operon (P(mcc)-lac), it was shown that the promoter of the microcin operon was also induced by stress caused by the transition of cells at the exponential growth phase into the medium without glucose as a sole carbon source. Activation of P(mcc)-lac expression upon severe glucose starvation occurred in rpoS+ and rpoS- strains. In cells carrying the rpoD800 mutation that renders the sigma70 subunit of RNA polymerase temperature-sensitive, an activation of P(mcc)-lac expression was observed at nonpermissive temperature, in contrast to its complete inhibition in E. coli cells at the phase of delayed growth. Other stressors-nitrogen starvation, high temperatures, osmotic shock, tetracycline and chloramphenicol-did not activate P(mcc)-lac expression in cells at the exponential growth phase.

  15. Interplay between the static ordering and dynamical heterogeneities determining the dynamics of rotation and ordinary liquid phases in 1,6-anhydro-β-D-glucose

    NASA Astrophysics Data System (ADS)

    Madejczyk, O.; Kaminski, K.; Kaminska, E.; Jurkiewicz, K.; Tarnacka, M.; Burian, A.; Paluch, M.

    2017-02-01

    In this letter, we reported thorough the structural and molecular dynamics studies on 1,6-anhydro-β-D-glucose, the second compound reported so far that is capable to form rotator and supercooled liquid phases. In contrast to the data presented for ethanol, temperature dependences of structural dynamics in both phases are very comparable. On the other hand, X ray measurements revealed unusually long range ordering/correlations between molecules in the ODIC (d ≈ 95 Å) and supercooled phases (d ≈ 30–40 Å) of this carbohydrate. Our consideration clearly demonstrated that the interplay between length scales of static range ordering and dynamical heterogeneities as well as internal molecular arrangement seem to be the key to understanding the molecular dynamics of different materials characterized by varying degree of disorder in the vicinity of the glass transition temperature.

  16. Interplay between the static ordering and dynamical heterogeneities determining the dynamics of rotation and ordinary liquid phases in 1,6-anhydro-β-D-glucose

    PubMed Central

    Madejczyk, O.; Kaminski, K.; Kaminska, E.; Jurkiewicz, K.; Tarnacka, M.; Burian, A.; Paluch, M.

    2017-01-01

    In this letter, we reported thorough the structural and molecular dynamics studies on 1,6-anhydro-β-D-glucose, the second compound reported so far that is capable to form rotator and supercooled liquid phases. In contrast to the data presented for ethanol, temperature dependences of structural dynamics in both phases are very comparable. On the other hand, X ray measurements revealed unusually long range ordering/correlations between molecules in the ODIC (d ≈ 95 Å) and supercooled phases (d ≈ 30–40 Å) of this carbohydrate. Our consideration clearly demonstrated that the interplay between length scales of static range ordering and dynamical heterogeneities as well as internal molecular arrangement seem to be the key to understanding the molecular dynamics of different materials characterized by varying degree of disorder in the vicinity of the glass transition temperature. PMID:28165065

  17. Combination of Peptide YY3–36 with GLP-17–36 amide Causes an Increase in First-Phase Insulin Secretion after IV Glucose

    PubMed Central

    Tan, Tricia M.; Salem, Victoria; Troke, Rachel C.; Alsafi, Ali; Field, Benjamin C. T.; De Silva, Akila; Misra, Shivani; Baynes, Kevin C. R.; Donaldson, Mandy; Minnion, James; Ghatei, Mohammad A.; Godsland, Ian F.

    2014-01-01

    Context: The combination of peptide YY (PYY) and glucagon-like peptide-1 (GLP-1) has been proposed as a potential treatment for diabetes and obesity. However, the combined effects of these hormones, PYY3–36 and GLP-17–36 amide, on glucose homeostasis are unknown. Objective: This study sought to investigate the acute effects of PYY3–36 and GLP-17–36 amide, individually and in combination, on insulin secretion and sensitivity. Setting and Design: Using a frequently sampled iv glucose tolerance test (FSIVGTT) and minimal modeling, this study measured the effects of PYY3–36 alone, GLP-17–36 amide alone, and a combination of PYY3–36 and GLP-17–36 amide on acute insulin response to glucose (AIRg) and insulin sensitivity index (SI) in 14 overweight human volunteers, studied in a clinical research facility. Results: PYY3–36 alone caused a small but nonsignificant increase in AIRg. GLP-17–36 amide alone and the combination of PYY3–36 and GLP-17–36 amide did increase AIRg significantly. No significant differences in SI were observed with any intervention. Conclusions: PYY3–36 lacks any significant acute effects on first-phase insulin secretion or SI when tested using an FSIVGTT. Both GLP-17–36 amide alone and the combination of PYY3–36 and GLP-17–36 amide increase first-phase insulin secretion. There does not seem to be any additive or synergistic effect between PYY3–36 and GLP-17–36 amide on first-phase insulin secretion. Neither hormone alone nor the combination had any significant effects on SI. PMID:25144632

  18. A mechanistic study to increase understanding of titanium dioxide nanoparticles-increased plasma glucose in mice.

    PubMed

    Hu, Hailong; Li, Li; Guo, Qian; Jin, Sanli; Zhou, Ying; Oh, Yuri; Feng, Yujie; Wu, Qiong; Gu, Ning

    2016-09-01

    Titanium dioxide nanoparticle (TiO2 NP) is an authorized food additive. Previous studies determined oral administration of TiO2 NPs increases plasma glucose in mice via inducing insulin resistance. An increase in reactive oxygen species (ROS) has been considered the possible mechanism of increasing plasma glucose. However, persistently high plasma glucose is also a mechanism of increasing ROS. This study aims to explore whether TiO2 NPs increase plasma glucose via ROS. We found after oral administration of TiO2 NPs, an increase in ROS preceded an increase in plasma glucose. Subsequently, mice were treated with two antioxidants (resveratrol and vitamin E) at the same time as oral administration of TiO2 NPs. Results showed resveratrol and vitamin E reduced TiO2 NPs-increased ROS. An increase in plasma glucose was also inhibited. Further research showed resveratrol and vitamin E inhibited the secretion of TNF-α and IL-6, and the phosphorylation of JNK and p38 MAPK, resulting in improved insulin resistance. These results suggest TiO2 NPs increased ROS levels, and then ROS activated inflammatory cytokines and phosphokinases, and thus induced insulin resistance, resulting in an increase in plasma glucose. Resveratrol and vitamin E can reduce TiO2 NPs-increased ROS and thereby inhibit an increase in plasma glucose in mice.

  19. Pulsed addition of HMF and furfural to batch-grown xylose-utilizing Saccharomyces cerevisiae results in different physiological responses in glucose and xylose consumption phase

    PubMed Central

    2013-01-01

    Background Pretreatment of lignocellulosic biomass generates a number of undesired degradation products that can inhibit microbial metabolism. Two of these compounds, the furan aldehydes 5-hydroxymethylfurfural (HMF) and 2-furaldehyde (furfural), have been shown to be an impediment for viable ethanol production. In the present study, HMF and furfural were pulse-added during either the glucose or the xylose consumption phase in order to dissect the effects of these inhibitors on energy state, redox metabolism, and gene expression of xylose-consuming Saccharomyces cerevisiae. Results Pulsed addition of 3.9 g L-1 HMF and 1.2 g L-1 furfural during either the glucose or the xylose consumption phase resulted in distinct physiological responses. Addition of furan aldehydes in the glucose consumption phase was followed by a decrease in the specific growth rate and the glycerol yield, whereas the acetate yield increased 7.3-fold, suggesting that NAD(P)H for furan aldehyde conversion was generated by acetate synthesis. No change in the intracellular levels of NAD(P)H was observed 1 hour after pulsing, whereas the intracellular concentration of ATP increased by 58%. An investigation of the response at transcriptional level revealed changes known to be correlated with perturbations in the specific growth rate, such as protein and nucleotide biosynthesis. Addition of furan aldehydes during the xylose consumption phase brought about an increase in the glycerol and acetate yields, whereas the xylitol yield was severely reduced. The intracellular concentrations of NADH and NADPH decreased by 58 and 85%, respectively, hence suggesting that HMF and furfural drained the cells of reducing power. The intracellular concentration of ATP was reduced by 42% 1 hour after pulsing of inhibitors, suggesting that energy-requiring repair or maintenance processes were activated. Transcriptome profiling showed that NADPH-requiring processes such as amino acid biosynthesis and sulfate and

  20. A prospective study of impaired fasting glucose and type 2 diabetes in China: The Kailuan study.

    PubMed

    Vaidya, Anand; Cui, Liufu; Sun, Lixia; Lu, Bing; Chen, Shuohua; Liu, Xing; Zhou, Yong; Liu, Xiurong; Xie, Xiaobing; Hu, Frank B; Wu, Shouling; Gao, Xiang

    2016-11-01

    The worldwide prevalence and incidence of diabetes and obesity are increasing in pandemic proportions. This is particularly relevant for China, where an extremely large population is growing, aging, and urbanizing. We thus conducted a prospective study to examine the prevalence and incidence of impaired fasting glucose (IFG) and diabetes, the rate at which fasting blood glucose rises, and the major modifiable risk factors associated with these outcomes in a large Chinese population from the Kailuan prospective study.A prospective cohort included 100,279 Chinese participants, aged 18 years or more, who had available information on fasting blood glucose concentrations at the start of the study (2006). Examination surveys were conducted every 2 years in 2008 and 2010. For the analyses of incident diabetes, we included 76,869 participants who were free of diabetes, cardiovascular disease, and cancer at the baseline and participants in the 2008 and/or 2010 follow-up. Diabetes was defined by a fasting blood glucose concentration ≥7 mmol/L, self-reported history, or active treatment with insulin or any oral hypoglycemic agent. IFG was defined by a fasting blood glucose concentration between 5.6 and 6.9 mmol/L.During the 4-year study, the prevalence of diabetes and IFG rose from 6.6% to 7.7%, and 17.3% to 22.6%, respectively. There were 17,811 incident cases of IFG and 4867 incident cases of diabetes. The age-standardized incident rate of IFG and diabetes were 62.6/1000 person-years (51.2/1000 person-years in women and 73.8/1000 person-years in men) and 10.0/1000 person-years (7.8/1000 person-years in women and 12.1/1000 person-years in men), respectively. We observed steady increases in fasting blood glucose with body anthropometrics and in every defined category of body mass index, including in those traditionally considered to be well within the "normal" range.In this large longitudinal study of Chinese adults, we observed a high prevalence and incidence of IFG

  1. Comparison of admission random glucose, fasting glucose, and glycated hemoglobin in predicting the neurological outcome of acute ischemic stroke: a retrospective study

    PubMed Central

    Sung, Jia-Ying; Chen, Chin-I; Hsieh, Yi-Chen; Chen, Yih-Ru; Wu, Hsin-Chiao; Chan, Lung; Hu, Chaur-Jong; Hu, Han-Hwa; Chiou, Hung-Yi

    2017-01-01

    Background Hyperglycemia is a known predictor of negative outcomes in stroke. Several glycemic measures, including admission random glucose, fasting glucose, and glycated hemoglobin (HbA1c), have been associated with bad neurological outcomes in acute ischemic stroke, particularly in nondiabetic patients. However, the predictive power of these glycemic measures is yet to be investigated. Methods This retrospective study enrolled 484 patients with acute ischemic stroke from January 2009 to March 2013, and complete records of initial stroke severity, neurological outcomes at three months, and glycemic measures were evaluated. We examined the predictive power of admission random glucose, fasting glucose, and HbA1c for neurological outcomes in acute ischemic stroke. Furthermore, subgroup analyses of nondiabetic patients and patients with diabetes were performed separately. Results Receiver operating characteristic (ROC) analysis revealed that admission random glucose and fasting glucose were significant predictors of poor neurological outcomes, whereas HbA1c was not (areas under the ROC curve (AUCs): admission random glucose = 0.564, p = 0.026; fasting glucose = 0.598, p = 0.001; HbA1c = 0.510, p = 0.742). Subgroup analyses of nondiabetic patients and those with diabetes revealed that only fasting glucose predicts neurological outcomes in patients with diabetes, and the AUCs of these three glycemic measures did not differ between the two groups. A multivariate logistic regression analysis of the study patients indicated that only age, initial stroke severity, and fasting glucose were independent predictors of poor neurological outcomes, whereas admission random glucose and HbA1c were not (adjusted odds ratio: admission random glucose = 1.002, p = 0.228; fasting glucose = 1.005, p = 0.039; HbA1c = 1.160, p = 0.076). Furthermore, subgroup multivariate logistic regression analyses of nondiabetic patients and those with diabetes indicated that none of the three glycemic

  2. A selectivity study of sodium-dependent glucose cotransporter 2/sodium-dependent glucose cotransporter 1 inhibitors by molecular modeling.

    PubMed

    Xu, Jinxing; Yuan, Haoliang; Ran, Ting; Zhang, Yanmin; Liu, Haichun; Lu, Shuai; Xiong, Xiao; Xu, Anyang; Jiang, Yulei; Lu, Tao; Chen, Yadong

    2015-08-01

    Sodium-dependent glucose cotransporters (SGLTs) play an important role in glucose reabsorption in the kidney and have been identified as promising targets to treat diabetes. Because of the side effects like glucose and galactose malabsorption by targeting SGLT1, highly selective SGLT2 inhibitors are more promising in the treatment of diabetes. To understand the mechanism of selectivity, we conducted selectivity-based three-dimensional quantitative structure-activity relationship studies to highlight the structure requirements for highly selective SGLT2 inhibitors. The best comparative molecular field analysis and comparative molecular similarity indices analysis models showed the noncross-validated coefficient (r(2) ) of 0.967 and 0.943, respectively. The predicted correlation coefficients (r(2) pred ) of 0.974 and 0.938 validated the reliability and predictability of these models. Besides, homology models of SGLT2 and SGLT1 were also constructed to investigate the selective mechanism from structure-based perspective. Molecular dynamics simulation and binding free energy calculation were performed on the systems of a potent and selective compound interacting with SGLT2 and SGLT1 to compare the different binding modes. The simulation results showed that the stretch of the methylthio group on Met241 had an essential effect on the different binding modes between SGLT1 and SGLT2, which was consistent with the three-dimensional quantitative structure-activity relationship analysis. Hydrogen bond analysis and binding free energy calculation revealed that SGLT2 binding complex was more stable and favorable than SGLT1 complex, which was highly correlated with the experimental results. Our obtained results give useful information for the investigation of the inhibitors' selectivity between SGLT2 and SGLT1 and will help for further development of highly selective SGLT2 inhibitors.

  3. A dynamic and stationary rheological study of erythrocytes incubated in a glucose medium.

    PubMed

    Riquelme, Bibiana; Foresto, Patricia; D'Arrigo, Mabel; Valverde, Juana; Rasia, Rodolfo

    2005-02-28

    A higher than normal glucose concentration in a suspending medium may produce non-enzymatic glycosylation of erythrocyte proteins. This process can modify the viscoelastic properties of erythrocytes. In this paper, we studied the possible relationship between glucose concentration in a suspending medium and erythrocyte rheological parameters. Human venous blood was obtained from the antecubital veins of 10 healthy volunteers. Blood samples were anticoagulated with EDTA and centrifuged. Red blood cells (RBCs) were washed and subsequently divided in aliquots, which were incubated in vitro with glucose solutions of different concentrations. Dynamic and stationary viscoelastic parameters of RBCs were determined by laser diffractometry in an Erythrodeformeter. Aggregate shape parameter (ASP) of the RBCs was determined by digital image processing. Significant changes were observed both in ASP and in rheological parameters when the glucose concentration in the medium was increased, demonstrating that a glucose concentration as low as 1% induces alterations in the mechanical properties of RBCs.

  4. Comparative study of different control techniques for the regulation of blood glucose level in diabetic patients.

    PubMed

    Ibbini, Mohammed S

    2009-01-01

    Blood glucose regulation is of a great concern for insulin-dependant patients with excessive glucose in blood (hyperglycaemia), or low glucose profile (hypoglycaemia) due to excess insulin delivery. Both conditions can cause dangerous complications for diabetic patients, and hence glucose regulation in blood is of prime importance. Insulin pumps are used to deliver insulin in small quantities, allowing the glucose level to remain as close as possible to that of non-diabetics (near 100 mg dl(-1)). Different control techniques are used to maintain the glucose level and most of them depend on an exact mathematical or empirical model of insulin-glucose interaction. Recently, we have proposed different controllers that are based on fuzzy logic and so do not use mathematical modelling, which in general is nonlinear, complex and suffers from uncertainties. PI fuzzy controllers are physically related to classical PI and PID controllers, which are extremely popular. The parameter settings of classical and fuzzy logic controllers are based on deep common physical background. In this manuscript, a comparative study is proposed to evaluate the use of fuzzy logic controllers over other conventional controllers such as PI and PID controllers to maintain the blood glucose level within a normoglycaemic average especially when a diabetic patient is subjected to different conditions.

  5. Synthesis of novel glucose-based polymers and their applications as chiral stationary phases for high performance liquid chromatography.

    PubMed

    Ikai, Tomoyuki; Yamada, Takayuki

    2016-01-01

    Two novel polymers containing glucose units as the main-chain that only differ in terms of their regioregularity were synthesized to evaluate their chiral recognition abilities as chiral stationary phases (CSPs) for high performance liquid chromatography (HPLC). The regioregular polymer (poly-5) shows clear resolution ability for the racemate of cobalt (III) acetylacetonate (Co(acac)3), whereas the corresponding regioirregular polymer (poly-3) does not show any chiral recognition for Co (acac)3. The regioregular polymer main-chain seems to play an important role not only in providing an efficient interaction with the racemate but also in expressing the chiral recognition ability as a CSP for HPLC.

  6. Suspension properties of whole blood and its components under glucose influence studied in patients with acute coronary syndrome

    NASA Astrophysics Data System (ADS)

    Malinova, Lidia I.; Simonenko, Georgy V.; Denisova, Tatyana P.; Dovgalevsky, Pavel Y.; Tuchin, Valery V.

    2004-05-01

    The protocol of our study includes men with acute myocardial infarction, stable angina pectoris of II and III functional classes and unstable angina pectoris. Patients with arterial hypertension, disorders in carbohydrate metabolism were excluded from the study. Blood samples taken under standardized conditions, were stabilized with citrate sodium 3,8% (1:9). Erythrocytes and platelets aggregation activity under glucose influence (in vitro) was studied by means of computer aided microphotometer -- a visual analyzer. Erythrocyte and platelets were united in special subsystem of whole blood. Temporal and functional characteristics of their aggregation were analyzed by creation of phase patterns fragments. The received data testify to interrelation of erythrocytes and platelets processes of aggregation under conditions of increasing of glucose concentration of the incubatory environment, which temporal and functional characteristics may be used for diagnostics and the prognosis of destabilization coronary blood flow at an acute coronary syndrome.

  7. The infusion of glucose in ewes during the luteal phase increases the number of follicles but reduces oestradiol production and some correlates of metabolic function in the large follicles.

    PubMed

    Gallet, Claire; Dupont, Joëlle; Campbell, Bruce K; Monniaux, Danielle; Guillaume, Daniel; Scaramuzzi, Rex J

    2011-09-01

    Short-term nutritional supplementation stimulates folliculogenesis in ewes probably by insulin-mediated actions of glucose in the follicle. The aim of this study was to determine the effect of glucose on follicle number and granulosa levels of Aromatase P450 and phosphorylated Akt and AMPK. Twelve Ile-de-France ewes were allocated to two groups; one (n=7) infused with saline and the other (n=5) with glucose (10mM/h) for 72h in the luteal phase. At the end of infusion, ovaries were collected and all follicles >1mm in diameter were dissected to recover granulosa cells. Aromatase P450 and phosphorylated Akt and AMPK were analysed by Western blotting of granulosa cell lysates. Blood plasmas collected before and during the infusions were analysed for progesterone, oestradiol, LH, FSH, glucose, insulin and IGF-I. The infusion of glucose significantly increased follicle number but, significantly reduced Aromatase P450 and phosphorylated Akt and AMPK in granulosa cells. The circulating concentration of glucose rose significantly 3h after the start of the glucose infusion and remained elevated until 27h then fell; the circulating concentration of insulin rose significantly by 3h and remained elevated. The circulating concentration of oestradiol fell significantly by 32h and remained low; the circulating concentrations of LH and FSH were unaffected. These data show that short-term infusion of glucose stimulated follicular growth but decreased Aromatase P450 in granulosa cells. The reduced levels of phosphorylated Akt and AMPK suggest that the phosphatidylinositol 3-kinase pathway has been inhibited by high concentrations of glucose. These data also suggest that there may be functional cross-talk between FSH and insulin signalling in granulosa cells.

  8. Reduced early and late phase insulin response to glucose in isolated spiny mouse (Acomys cahirinus) islets: a defective link between glycolysis and adenylate cyclase.

    PubMed

    Nesher, R; Abramovitch, E; Cerasi, E

    1989-09-01

    The spiny mouse (Acomys cahirinus) exhibits low insulin responsiveness to glucose with a nearly absent early phase release. The alternative fuel-secretagogue glyceraldehyde (10 mmol/l) produced a maximal early insulin response in rat islets but failed to affect early response in Acomys; however, it potentiated the late insulin response in both species alike. Glucagon (1.5 mumol/l) potentiated the early insulin response to intermediate (8.3 mmol/l) glucose in rat and Acomys islets by two- and four-fold, respectively. Glucose doubled cyclic AMP levels in rat islets but no significant response was noted in Acomys islets. Isobutylmethylxanthine (0.1 mmol/l) and forskolin (25 mumol/l) caused a significant rise in islet cyclic AMP levels in both types of islets; however, neither agent restored the glucose stimulation of cyclic AMP in spiny mouse islets. Forskolin and isobutylmethylxanthine potentiated early and late phase insulin release in both species; however, neither augmented the early response in the Acomys to the degree observed in rat islets. Thus: (1) A deficient link exists in Acomys between glycolysis and subsequent signals. (2) These islets contain a glucose-insensitive adenylate cyclase. (3) The early insulin response may be potentiated by direct activation of adenylate cyclase. (4) The glucose effects on early and late phase insulin release are probably mediated by distinct pathways. (5) In the spiny mouse the signals mediating the early response are deranged to a greater extent than those activating the late phase insulin release.

  9. Association between Dietary Acid Load and Insulin Resistance: Tehran Lipid and Glucose Study

    PubMed Central

    Moghadam, Sajjad Khalili; Bahadoran, Zahra; Mirmiran, Parvin; Tohidi, Maryam; Azizi, Fereidoun

    2016-01-01

    In the current study, we investigated the longitudinal association between dietary acid load and the risk of insulin resistance (IR) in the Tehranian adult population. This longitudinal study was conducted on 925 participants, aged 22~80 years old, in the framework of the third (2006~2008) and fourth (2009~2011) phases of the Tehran Lipid and Glucose Study. At baseline, the dietary intake of subjects was assessed using a validated semi-quantitative food frequency questionnaire, and the potential renal acid load (PRAL) and net endogenous acid production (NEAP) scores were calculated at baseline. Fasting serum insulin and glucose were measured at baseline and again after a 3-year of follow-up; IR was defined according to optimal cut-off values. Multiple logistic regression models were used to estimate the risk of IR according to the PRAL and NEAP quartile categories. Mean age and body mass index of the participants were 40.3 years old of 26.4 kg/m2, respectively. Mean PRAL and NEAP scores were −11.2 and 35.6 mEq/d, respectively. After adjustment for potential confounders, compared to the lowest quartile of PRAL and NEAP, the highest quartile was accompanied with increased risk of IR [odds ratio (OR)=2.81, 95% confidence interval (CI)=1.32~5.97 and OR=2.18, 95% CI=1.03 ~4.61, respectively]. Our findings suggest that higher acidic dietary acid-base load, defined by higher PRAL and NEAP scores, may be a risk factor for the development of IR and related metabolic disorders. PMID:27390726

  10. Dielectric spectroscopy study of specific glucose influence on human erythrocyte membranes

    NASA Astrophysics Data System (ADS)

    Hayashi, Yoshihito; Livshits, Leonid; Caduff, Andreas; Feldman, Yuri

    2003-02-01

    Time domain dielectric spectroscopy has been used to study spherical erythrocytes, suspended in diluted phosphate buffered saline (PBS) buffers at varying concentrations of D- and L-glucose at 25°C. The osmolarity for each glucose solution was adapted, equalling that of a 63% PBS (183 mOsm). The strong effect of the electrode polarization was corrected using the fractal approach in time domain. For analysis of the dielectric properties of suspensions of erythrocytes, the Maxwell-Wagner model is used for small volume fractions. Values of the permittivity and conductivity of the cell membrane were obtained from a fitting procedure according to the one-shell model. The non-monotonic and specific response of membrane electric properties on D-glucose concentrations were observed, with a dramatic decrease around 12 mM. No changes of membrane properties have been observed in the presence of increasing concentrations of L-glucose, the biologically inactive enantiomer of D-glucose. The effect is thus specific to D-glucose. The possible mechanism of specific cell reaction to D-glucose is discussed in this paper.

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

    PubMed Central

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

    2017-01-01

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

  12. Rp-cAMPS Prodrugs Reveal the cAMP Dependence of First-Phase Glucose-Stimulated Insulin Secretion.

    PubMed

    Schwede, Frank; Chepurny, Oleg G; Kaufholz, Melanie; Bertinetti, Daniela; Leech, Colin A; Cabrera, Over; Zhu, Yingmin; Mei, Fang; Cheng, Xiaodong; Manning Fox, Jocelyn E; MacDonald, Patrick E; Genieser, Hans-G; Herberg, Friedrich W; Holz, George G

    2015-07-01

    cAMP-elevating agents such as the incretin hormone glucagon-like peptide-1 potentiate glucose-stimulated insulin secretion (GSIS) from pancreatic β-cells. However, a debate has existed since the 1970s concerning whether or not cAMP signaling is essential for glucose alone to stimulate insulin secretion. Here, we report that the first-phase kinetic component of GSIS is cAMP-dependent, as revealed through the use of a novel highly membrane permeable para-acetoxybenzyl (pAB) ester prodrug that is a bioactivatable derivative of the cAMP antagonist adenosine-3',5'-cyclic monophosphorothioate, Rp-isomer (Rp-cAMPS). In dynamic perifusion assays of human or rat islets, a step-wise increase of glucose concentration leads to biphasic insulin secretion, and under these conditions, 8-bromoadenosine-3',5'-cyclic monophosphorothioate, Rp-isomer, 4-acetoxybenzyl ester (Rp-8-Br-cAMPS-pAB) inhibits first-phase GSIS by up to 80%. Surprisingly, second-phase GSIS is inhibited to a much smaller extent (≤20%). Using luciferase, fluorescence resonance energy transfer, and bioluminescence resonance energy transfer assays performed in living cells, we validate that Rp-8-Br-cAMPS-pAB does in fact block cAMP-dependent protein kinase activation. Novel effects of Rp-8-Br-cAMPS-pAB to block the activation of cAMP-regulated guanine nucleotide exchange factors (Epac1, Epac2) are also validated using genetically encoded Epac biosensors, and are independently confirmed in an in vitro Rap1 activation assay using Rp-cAMPS and Rp-8-Br-cAMPS. Thus, in addition to revealing the cAMP dependence of first-phase GSIS from human and rat islets, these findings establish a pAB-based chemistry for the synthesis of highly membrane permeable prodrug derivatives of Rp-cAMPS that act with micromolar or even nanomolar potency to inhibit cAMP signaling in living cells.

  13. Glucose metabolism in completed suicide: a forensic-pathological pilot study

    PubMed Central

    Forsman, Jonas; Keltanen, Terhi; Liberg, Benny; Sajantila, Antti; Masterman, Thomas; Lindroos, Katarina

    2017-01-01

    Aim To determine whether antemortem blood levels of glycated hemoglobin (HbA1c) and glucose predict completed suicide and, by extension, whether markers of glucose metabolism might be associated with a prosuicidal trait or state. Method From consecutively performed autopsies, samples of blood and vitreous humor from 17 suicide victims and 27 non-suicide controls were compared with regard to levels of glucose, lactate, and HbA1c. Results Mean HbA1c was higher and mean estimated blood glucose was lower among suicide victims, although tests revealed no significant differences (P = 0.171 and P = 0.395, respectively). HbA1c levels exceeding 48.0 mmol/mol, which were indicative of persistent hyperglycemia, were twice as common in suicide victims (59% vs 30%; P = 0.068). Conclusion The finding of this pilot study suggest that deranged glucose metabolism may reflect biological events antecedent to, or concomitant with, completed suicide, with the following clinical implications: recurring hyperglycemia due to defective glucose transport, which may give rise to depression and suicidal ideation, and elevated HbA1c levels, which may represent an assayable correlate to neurobiological conditions predisposing to suicide. PMID:28252873

  14. Studies of fatty liver and kidney syndrome in chickens: dynamics of glucose metabolism.

    PubMed

    Balnave, D; Wolfenden, J; Ball, F M; Cumming, R B; Leng, R A

    1977-11-01

    1. Fatty liver and kidney syndrome (FLKS) was induced in a proportion of a group of 4-week-old chickens by giving a diet of meat meal and wheat; inclusion in the diet of animal tallow for 54 h substantially reduced the occurrence of FLKS. 2. Measurements of dynamic aspects of glucose metabolism were made with single injections of [2-3H]glucose which indicated that birds given the 'FLKS-inducing' diet and showing physical symptoms of FLKS had significantly lower rates of synthesis of glucose than birds given either the same diet supplemented with tallow or a commercial diet. 3. In a second series of experiments glucose metabolism was studied in birds (1) with or without physical symptoms that were given the 'FLKS-inducing' diet and (2) birds given the same diet supplemented with tallow or biotin. Affected birds fed the 'FLKS-inducing' diet had significantly lower plasma glucose concentrations, pool sizes and synthesis rates than birds fed the same diet and not showing symptoms, or birds fed the supplemented diets. 4. It is suggested that the cause of death in birds with FLKS is a low rate of gluconeogenesis during periods without feed which results in a lack of glucose to meet essential functions.

  15. Global cerebral glucose utilization is independent of brain size: a PET Study

    SciTech Connect

    Hatazawa, J.; Brooks, R.A.; Di Chiro, G.; Campbell, G.

    1987-07-01

    Cerebral glucose metabolic rates were measured in 80 normal volunteers by studying the uptake of (/sup 18/F)deoxyglucose with positron emission tomography (PET), using three PET scanners. A brain size index was determined from the PET images using either length-width or area measurements of the brain at a standard level. There was a significant negative correlation between glucose metabolism per unit volume and brain size that was well described by an inverse functional relationship, implying that the total glucose consumption of the brain is approximately constant. Analyses of men versus women revealed no sex differences in total brain glucose consumption, although there were differences in brain size and in glucose metabolism per unit volume. Similarly there was no significant correlation of total brain glucose consumption with age. The variation with brain size accounted for 46% of the logarithmic intersubject metabolic variance. When comparing global metabolic rates in different subjects, multiplying the rates by a brain size index has the dual advantage of correcting for differences related to brain size and correcting for differences in cerebrospinal fluid volume.

  16. Brain glucose overexposure and lack of acute metabolic flexibility in obesity and type 2 diabetes: a PET-[18F]FDG study in Zucker and ZDF rats.

    PubMed

    Liistro, Tiziana; Guiducci, Letizia; Burchielli, Silvia; Panetta, Daniele; Belcari, Nicola; Pardini, Silvia; Del Guerra, Alberto; Salvadori, Piero A; Iozzo, Patricia

    2010-05-01

    Brain glucose exposure may complicate diabetes and obesity. We used positron emission tomography with (18)F-fluorodeoxyglucose in Zucker obese, diabetic, and control rats to determine the contributions of blood glucose mass action versus local mechanisms in regulating central glucose disposal in fasted and acutely glucose-stimulated states, and their adaptations in obesity and diabetes. Our study data indicate that brain glucose uptake is dependent on both local and mass action components, and is stimulated by acute glucose intake in healthy rats. In diseased animals, the organ was chronically overexposed to glucose, due to high fasting glucose uptake, almost abolishing the physiologic response to glucose loading.

  17. A new application of electrical impedance spectroscopy for measuring glucose metabolism: a phantom study

    NASA Astrophysics Data System (ADS)

    Dhurjaty, Sreeram; Qiu, Yuchen; Tan, Maxine; Liu, Hong; Zheng, Bin

    2015-03-01

    Glucose metabolism relates to biochemical processes in living organisms and plays an important role in diabetes and cancer-metastasis. Although many methods are available for measuring glucose metabolism-activities, from simple blood tests to positron emission tomography, currently there is no robust and affordable device that enables monitoring of glucose levels in real-time. In this study we tested feasibility of applying a unique resonance-frequency based electronic impedance spectroscopy (REIS) device that has been, recently developed to measure and monitor glucose metabolism levels using a phantom study. In this new testing model, a multi-frequency electrical signal sequence is applied and scanned through the subject. When the positive reactance of an inductor inside the device cancels out the negative reactance of the capacitance of the subject, the electrical impedance reaches a minimum value and this frequency is defined as the resonance frequency. The REIS system has a 24-bit analog-to-digital signal convertor and a frequency-resolution of 100Hz. In the experiment, two probes are placed inside a 100cc container initially filled with distilled water. As we gradually added liquid-glucose in increments of 1cc (250mg), we measured resonance frequencies and minimum electrical signal values (where A/D was normalized to a full scale of 1V). The results showed that resonance frequencies monotonously decreased from 243kHz to 178kHz, while the minimum voltages increased from 405mV to 793mV as the added amount of glucose increased from 0 to 5cc. The study demonstrated the feasibility of applying this new REIS technology to measure and/or monitor glucose levels in real-time in future.

  18. Multisite Study of an Implanted Continuous Glucose Sensor Over 90 Days in Patients With Diabetes Mellitus

    PubMed Central

    Dehennis, Andrew; Mortellaro, Mark A.; Ioacara, Sorin

    2015-01-01

    Background: Continuous glucose monitoring (CGM), which enables real-time glucose display and trend information as well as real-time alarms, can improve glycemic control and quality of life in patients with diabetes mellitus. Previous reports have described strategies to extend the useable lifetime of a single sensor from 1-2 weeks to 28 days. The present multisite study describes the characterization of a sensing platform achieving 90 days of continuous use for a single, fully implanted sensor. Method: The Senseonics CGM system is composed of a long-term implantable glucose sensor and a wearable smart transmitter. Study subjects underwent subcutaneous implantation of sensors in the upper arm. Eight-hour clinic sessions were performed every 14 days, during which sensor glucose values were compared against venous blood lab reference measurements collected every 15 minutes using mean absolute relative differences (MARDs). Results: All subjects (mean ± standard deviation age: 43.5 ± 11.0 years; with 10 sensors inserted in men and 14 in women) had type 1 diabetes mellitus. Most (22 of 24) sensors reported glucose values for the entire 90 days. The MARD value was 11.4 ± 2.7% (range, 8.1-19.5%) for reference glucose values between 40-400 mg/dl. There was no significant difference in MARD throughout the 90-day study (P = .31). No serious adverse events were noted. Conclusions: The Senseonics CGM, composed of an implantable sensor, external smart transmitter, and smartphone app, is the first system that uses a single sensor for continuous display of accurate glucose values for 3 months. PMID:26224762

  19. Imaging phased telescope array study

    NASA Technical Reports Server (NTRS)

    Harvey, James E.

    1989-01-01

    The problems encountered in obtaining a wide field-of-view with large, space-based direct imaging phased telescope arrays were considered. After defining some of the critical systems issues, previous relevant work in the literature was reviewed and summarized. An extensive list was made of potential error sources and the error sources were categorized in the form of an error budget tree including optical design errors, optical fabrication errors, assembly and alignment errors, and environmental errors. After choosing a top level image quality requirment as a goal, a preliminary tops-down error budget allocation was performed; then, based upon engineering experience, detailed analysis, or data from the literature, a bottoms-up error budget reallocation was performed in an attempt to achieve an equitable distribution of difficulty in satisfying the various allocations. This exercise provided a realistic allocation for residual off-axis optical design errors in the presence of state-of-the-art optical fabrication and alignment errors. Three different computational techniques were developed for computing the image degradation of phased telescope arrays due to aberrations of the individual telescopes. Parametric studies and sensitivity analyses were then performed for a variety of subaperture configurations and telescope design parameters in an attempt to determine how the off-axis performance of a phased telescope array varies as the telescopes are scaled up in size. The Air Force Weapons Laboratory (AFWL) multipurpose telescope testbed (MMTT) configuration was analyzed in detail with regard to image degradation due to field curvature and distortion of the individual telescopes as they are scaled up in size.

  20. Obesity Paradox and Recurrent Coronary Heart Disease in a Population-Based Study: Tehran Lipid and Glucose Study

    PubMed Central

    Asgari, Samaneh; Barzin, Maryam; Hosseinpanah, Farhad; Hadaegh, Farzad; Azizi, Fereidoun; Khalili, Davood

    2016-01-01

    Background Although current data shows a positive association between obesity and development of coronary heart disease (CHD) in general population, there is limited data on the important protective role of central or general obesity in patients with prevalent CHD or the “obesity paradox”, from this region. Objectives The objective of the present investigation was to describe the relationship between BMI categories and the recurrence of CHD in patients with a history of CHD using data from a large population-based study, the Tehran lipid and glucose study (TLGS). Patients and Methods The study was conducted on 440 adults, aged ≥ 30 years, with a history of CHD at baseline who attended the first (1999 - 2001) or second (2001 - 2003) phases of the Tehran Lipid and Glucose Study and had at least one year of follow-up until March 31, 2010. Cox proportional hazard models were used to evaluate the association among various BMI groups and recurrent CHD incidence. Results During a median follow-up of 8.44 years, 169 new cases of CHD occurred (incidence density of: 54.53 per 1000 person-years). The incidence of recurrent CHD was higher in the normal BMI compared with overweight and obese categories (68.71, 47.56 and 54.46 per 1000 person-years, respectively). In multivariable models, using the forward stepwise selection approach, compared to the overweight group (0.48 95% CI, 0.30-0.80), the obese group (0.55 95% CI, 0.28-1.06) lost its significant protective effect. Conclusions Results of this study demonstrated an apparently protective effect for overweight in comparison with normal weight against long-term recurrent CHD in patients with history of CHD. PMID:27761144

  1. Study of potential utility of new radiopharmaceuticals based on technetium-99m labeled derivative of glucose

    NASA Astrophysics Data System (ADS)

    Zeltchan, R.; Medvedeva, A.; Sinilkin, I.; Chernov, V.; Stasyuk, E.; Rogov, A.; Il'ina, E.; Larionova, L.; Skuridin, V.

    2016-08-01

    Purpose: to study the potential utility of 1-thio-D-glucose labeled with 99mTc for cancer imaging in laboratory animals. Materials and method: the study was carried out in cell cultures of normal CHO (Chinese hamster ovary cells CHO) and malignant tissues MCF-7 (human breast adenocarcinoma MCF-7). To evaluate the uptake of 99mTc-1-thio-D-glucose in normal and tumor tissue cells, 25 MBq of 1-thio-D-glucose labeled with 99mTc was added to the vials with 3 million cells and incubated for 30 min at room temperature. After centrifugation of the vials with cells, the supernatant was removed. The radioactivity in vials with normal and tumor cells was then measured. In addition, the study included 40 mice of C57B1/6j lines with tumor lesion of the right femur. For neoplastic lesions, Lewis lung carcinoma model was used. Following anesthesia, mice were injected intravenously with 25 MBq of 99mTc-1-thio-D-glucose. Planar scintigraphy was performed 15 minutes later in a matrix of 512x512 pixels for 5 min. Results: when measuring the radioactivity of normal and malignant cells after incubation with 99mTc-1-thio-D-glucose, it was found that the radioactivity of malignant cells was higher than that of normal cells. The mean values of radioactivity levels in normal and malignant cells were 0.3 ± 0.15 MBq and 1.07 ± 0.6 MBq, respectively. All examined animals had increased accumulation of 99mTc-1-thio-D-glucose at the tumor site. The accumulation of 99mTc-1-thio-D-glucose in the tumor was on average twice as high as compared to the symmetric region. Conclusion: The present study demonstrated that 99mTc-1-thio-D-glucose is a prospective radiopharmaceutical for cancer visualization. In addition, high accumulation of 99mTc-1-thio-D-glucose in the culture of cancer cells and in tumor tissue of animals demonstrates tumor tropism of the radiopharmaceutical.

  2. Experimental study of radiopharmaceuticals based on technetium-99m labeled derivative of glucose for tumor diagnosis

    NASA Astrophysics Data System (ADS)

    Zeltchan, R.; Medvedeva, A.; Sinilkin, I.; Bragina, O.; Chernov, V.; Stasyuk, E.; Rogov, A.; Il'ina, E.; Larionova, L.; Skuridin, V.; Dergilev, A.

    2016-06-01

    Purpose: to study the potential utility of 1-thio-D-glucose labeled with 99mTc for cancer imaging in laboratory animals. Materials and method: the study was carried out in cell cultures of normal CHO (Chinese hamster ovary cells CHO) and malignant tissues MCF-7 (human breast adenocarcinoma MCF-7). To evaluate the uptake of 99mTc-1-thio-D-glucose in normal and tumor tissue cells, 25 MBq of 1-thio-D-glucose labeled with 99mTc was added to the vials with 3 million cells and incubated for 30 minutes at room temperature. After centrifugation of the vials with cells, the supernatant was removed. Radioactivity in vials with normal and tumor cells was then measured. In addition, the study included 40 mice of C57B 1/6j lines with tumor lesion of the right femur. For neoplastic lesions, Lewis lung carcinoma model was used. Following anesthesia, mice were injected intravenously with 25MBq of 99mTc-1-thio-D-glucose. Planar scintigraphy was performed 15 minutes later in a matrix of 512x512 pixels for 5 minutes. Results: when measuring the radioactivity of normal and malignant cells after incubation with 99mTc-1-thio-D- glucose, it was found that the radioactivity of malignant cells was higher than that of normal cells. The mean values of radioactivity levels in normal and malignant cells were 0.3±0.15MBq and 1.07±0.6MBq, respectively. All examined animals had increased accumulation of 99mTc-1-thio- D-glucose at the tumor site. The accumulation of 99mTc-1-thio-D-glucose in the tumor was on average twice as high as compared to the symmetric region. Conclusion: The present study demonstrated that 99mTc-1-thio-D-glucose is a prospective radiopharmaceutical for cancer visualization. In addition, high accumulation of 99mTc-1-thio-D-glucose in the culture of cancer cells and in tumor tissue of animals demonstrates tumor tropism of the radiopharmaceutical.

  3. Sputum glucose and glycemic control in cystic fibrosis-related diabetes: a cross-sectional study.

    PubMed

    Van Sambeek, Lindsey; Cowley, Elise S; Newman, Dianne K; Kato, Roberta

    2015-01-01

    Cystic fibrosis-related diabetes affects up to half of cystic fibrosis patients and is associated with increased mortality and more frequent pulmonary exacerbations. However, it is unclear to what degree good glycemic control might mitigate these risks and clinical outcomes have not previously been studied in relation to glucose from the lower airways, the site of infection and CF disease progression. We initially hypothesized that diabetic cystic fibrosis patients with glycosylated hemoglobin (HbA(1c)) > 6.5% have worse pulmonary function, longer and more frequent exacerbations and also higher sputum glucose levels than patients with HbA(1c) ≤ 6.5% or cystic fibrosis patients without diabetes. To test this, we analyzed spontaneously expectorated sputum samples from 88 cystic fibrosis patients. The median sputum glucose concentration was 0.70 mM (mean, 4.75 mM; range, 0-64.6 mM). Sputum glucose was not correlated with age, sex, body mass index, diabetes diagnosis, glycemic control, exacerbation frequency or length, or pulmonary function. Surprisingly, sputum glucose was highest in subjects with normal glucose tolerance, suggesting the dynamics of glycemic control, sputum glucose and pulmonary infections are more complex than previously thought. Two-year mean HbA(1c) was positively correlated with the length of exacerbation admission (p < 0.01), and negatively correlated with measures of pulmonary function (p < 0.01). While total number of hospitalizations for exacerbations were not significantly different, subjects with an HbA(1c) > 6.5% were hospitalized on average 6 days longer than those with HbA(1c) ≤ 6.5% (p < 0.01). Current clinical care guidelines for cystic fibrosis-related diabetes target HbA(1c) ≤ 7% to limit long-term microvascular damage, but more stringent glycemic control (HbA(1c) ≤ 6.5%) may further reduce the short-term pulmonary complications.

  4. Glucose starvation as a selective tool for the study of adaptive mutations in Saccharomyces cerevisiae.

    PubMed

    Heidenreich, Erich; Steinboeck, Ferdinand

    2017-01-01

    Mutations not only arise in proliferating cells but also in resting - thus non-replicating - cells. Such stationary-phase mutations may occasionally enable an escape from growth repression and e.g. contribute to cancerogenesis or development of drug resistance. The most widely used condition for the study of such adaptive mutations in the eukaryotic model organism Saccharomyces cerevisiae is the starvation for a single amino acid. To overcome some limitations of this experimental setup we developed a new adaptive mutation assay that allows a screening for mutagenic processes during a more regular cell cycle arrest induced by the lack of a fermentable carbon source. We blocked one essential step of gluconeogenesis by inactivation of the FBP1 gene. This drives the cells into a cell cycle arrest when glucose is not available in the medium although a non-fermentable carbon source is present. As another component of the new mutation assay, we established a custom-designed test allele that contains a microsatellite sequence as a target for mutations. We demonstrated the feasibility and validity of this novel experimental setup by the observation and characterization of adaptive mutants.

  5. Computational studies of the thermochemistry for conversion of glucose to levulinic acid.

    SciTech Connect

    Assary, R. S.; Redfern, P. C.; Hammond, J. R.; Greeley, J.; Curtiss, L. A.; Northwestern Univ.

    2010-07-15

    The thermochemistry of the conversion of glucose to levulinic acid through fructofuranosyl intermediates is investigated using the high-level ab initio methods G4 and G4MP2. The calculated gas phase reaction enthalpies indicate that the first two steps involving water molecule elimination are highly endothermic, while the other steps, including additional water elimination and rehydration to form levulinic acid, are exothermic. The calculated gas phase free energies indicate that inclusion of entropic effects makes the dehydration steps more favorable, although the elimination of the first water is still endothermic. Elevated temperatures and aqueous reaction environments are also predicted to make the dehydration reaction steps thermodynamically more favorable. On the basis of these enthalpy and free energy calculations, the first dehydration step in conversion of glucose to levulinic acid is likely a key step in controlling the overall progress of the reaction. An assessment of density functional theories and other theoretical methods for the calculation of the dehydration and hydration reactions in the decomposition of glucose is also presented.

  6. Computational Studies of the Thermochemistry for Conversion of Glucose to Levulinic Acid

    SciTech Connect

    Assary, Rajeev S.; Redfern, Paul C; Hammond, Jeffrey; Greeley, Jeffrey P; Curtiss, Larry A

    2010-07-15

    The thermochemistry of the conversion of glucose to levulinic acid through fructofuranosyl intermediates is investigated using the high-level ab initio methods G4 and G4MP2. The calculated gas phase reaction enthalpies indicate that the first two steps involving water molecule elimination are highly endothermic, while the other steps, including additional water elimination and rehydration to form levulinic acid, are exothermic. The calculated gas phase free energies indicate that inclusion of entropic effects makes the dehydration steps more favorable, although the elimination of the first water is still endothermic. Elevated temperatures and aqueous reaction environments are also predicted to make the dehydration reaction steps thermodynamically more favorable. On the basis of these enthalpy and free energy calculations, the first dehydration step in conversion of glucose to levulinic acid is likely a key step in controlling the overall progress of the reaction. An assessment of density functional theories and other theoretical methods for the calculation of the dehydration and hydration reactions in the decomposition of glucose is also presented.

  7. Sleep Disturbances and Glucose Metabolism in Older Adults: The Cardiovascular Health Study

    PubMed Central

    Carnethon, Mercedes; Biggs, Mary Lou; Djoussé, Luc; Kaplan, Robert C.; Siscovick, David S.; Robbins, John A.; Redline, Susan; Patel, Sanjay R.; Janszky, Imre; Mukamal, Kenneth J.

    2015-01-01

    OBJECTIVE We examined the associations of symptoms of sleep-disordered breathing (SDB), which was defined as loud snoring, stopping breathing for a while during sleep, and daytime sleepiness, and insomnia with glucose metabolism and incident type 2 diabetes in older adults. RESEARCH DESIGN AND METHODS Between 1989 and 1993, the Cardiovascular Health Study recruited 5,888 participants ≥65 years of age from four U.S. communities. Participants reported SDB and insomnia symptoms yearly through 1989–1994. In 1989–1990, participants underwent an oral glucose tolerance test, from which insulin secretion and insulin sensitivity were estimated. Fasting glucose levels were measured in 1989–1990 and again in 1992–1993, 1994–1995, 1996–1997, and 1998–1999, and medication use was ascertained yearly. We determined the cross-sectional associations of sleep symptoms with fasting glucose levels, 2-h glucose levels, insulin sensitivity, and insulin secretion using generalized estimated equations and linear regression models. We determined the associations of updated and averaged sleep symptoms with incident diabetes in Cox proportional hazards models. We adjusted for sociodemographics, lifestyle factors, and medical history. RESULTS Observed apnea, snoring, and daytime sleepiness were associated with higher fasting glucose levels, higher 2-h glucose levels, lower insulin sensitivity, and higher insulin secretion. The risk of the development of type 2 diabetes was positively associated with observed apnea (hazard ratio [HR] 1.84 [95% CI 1.19–2.86]), snoring (HR 1.27 [95% CI 0.95–1.71]), and daytime sleepiness (HR 1.54 [95% CI 1.13–2.12]). In contrast, we did not find consistent associations between insomnia symptoms and glucose metabolism or incident type 2 diabetes. CONCLUSIONS Easily collected symptoms of SDB are strongly associated with insulin resistance and the incidence of type 2 diabetes in older adults. Monitoring glucose metabolism in such patients may

  8. Kinetics and isotope patterns of ethanol and acetaldehyde emissions from yeast fermentations of glucose and glucose-6,6-d2 using selected ion flow tube mass spectrometry: a case study.

    PubMed

    Smith, David; Wang, Tianshu; Spanel, Patrik

    2002-01-01

    As a prelude to investigations of the emission of metabolites from human cell lines in vitro, we have conducted a study using selected ion flow tube mass spectrometry (SIFT-MS) of the acetaldehyde and ethanol that appear in the headspace above a fermenting yeast/glucose/water mixture in sealed glass bottles at a temperature of 30 degrees C. A fixed quantity of yeast (10 mg) and varying amounts (2, 4, 8 and 16 mg) of both non-deuterated glucose and glucose-6,6-d2 in 5 mL of water were used and the emission of the acetaldehyde and the ethanol were observed as a function of time. The ethanol and acetaldehyde concentrations in the headspace were obtained from the magnitudes of their characteristic ions on the accumulated SIFT mass spectra and, when the deuterated glucose was used, characteristic singly and doubly deuterated ions were obvious. This study indicates, as expected, that ethanol is the major species generated and that acetaldehyde is a relatively minor component of the headspace and a very minor component of the liquid phase. We estimate that about 10(8) ethanol molecules are produced per minute per cell in this yeast fermentation process. The distribution of the non-deuterated and partially deuterated ethanol under these fermentation conditions is observed to be C2H5OH (66 +/- 4)%, C2H4DOH(6 +/- 1)%, C2H3D2OH(28 +/- 4)%, and the analogous distribution for the acetaldehyde is the same, within error. These results indicate that the D atoms in the glucose-6,6-d2 are mostly retained by the 6-C atom, but the appearance of the singly deuterated ethanol and acetaldehyde indicates that some D/H mixing must be occurring in the enzymatic reactions. The results of this study illustrate the potential and power of on-line SIFT-MS analysis in this area of research.

  9. Membrane potential dye imaging of ventromedial hypothalamus neurons from adult mice to study glucose sensing.

    PubMed

    Vazirani, Reema P; Fioramonti, Xavier; Routh, Vanessa H

    2013-11-27

    Studies of neuronal activity are often performed using neurons from rodents less than 2 months of age due to the technical difficulties associated with increasing connective tissue and decreased neuronal viability that occur with age. Here, we describe a methodology for the dissociation of healthy hypothalamic neurons from adult-aged mice. The ability to study neurons from adult-aged mice allows the use of disease models that manifest at a later age and might be more developmentally accurate for certain studies. Fluorescence imaging of dissociated neurons can be used to study the activity of a population of neurons, as opposed to using electrophysiology to study a single neuron. This is particularly useful when studying a heterogeneous neuronal population in which the desired neuronal type is rare such as for hypothalamic glucose sensing neurons. We utilized membrane potential dye imaging of adult ventromedial hypothalamic neurons to study their responses to changes in extracellular glucose. Glucose sensing neurons are believed to play a role in central regulation of energy balance. The ability to study glucose sensing in adult rodents is particularly useful since the predominance of diseases related to dysfunctional energy balance (e.g. obesity) increase with age.

  10. Tattoo-based noninvasive glucose monitoring: a proof-of-concept study.

    PubMed

    Bandodkar, Amay J; Jia, Wenzhao; Yardımcı, Ceren; Wang, Xuan; Ramirez, Julian; Wang, Joseph

    2015-01-06

    We present a proof-of-concept demonstration of an all-printed temporary tattoo-based glucose sensor for noninvasive glycemic monitoring. The sensor represents the first example of an easy-to-wear flexible tattoo-based epidermal diagnostic device combining reverse iontophoretic extraction of interstitial glucose and an enzyme-based amperometric biosensor. In-vitro studies reveal the tattoo sensor's linear response toward physiologically relevant glucose levels with negligible interferences from common coexisting electroactive species. The iontophoretic-biosensing tattoo platform is reduced to practice by applying the device on human subjects and monitoring variations in glycemic levels due to food consumption. Correlation of the sensor response with that of a commercial glucose meter underscores the promise of the tattoo sensor to detect glucose levels in a noninvasive fashion. Control on-body experiments demonstrate the importance of the reverse iontophoresis operation and validate the sensor specificity. This preliminary investigation indicates that the tattoo-based iontophoresis-sensor platform holds considerable promise for efficient diabetes management and can be extended toward noninvasive monitoring of other physiologically relevant analytes present in the interstitial fluid.

  11. The effect of glucose when added to a fat load on the response of glucagon-like peptide-1 (GLP-1) and apolipoprotein B-48 in the postprandial phase.

    PubMed

    Zemánková, K; Mrázková, J; Piťha, J; Kovář, J

    2015-01-01

    Increased and prolonged postprandial lipemia has been identified as a risk factor of cardiovascular disease. However, there is no consensus on how to test postprandial lipemia, especially with respect to the composition of an experimental meal. To address this question of how glucose, when added to a fat load, affects the selected parameters of postprandial lipemia, we carried out a study in 30 healthy male volunteers. Men consumed an experimental meal containing either 75 g of fat + 25 g of glucose (F+G meal) or 75 g of fat (F meal) in a control experiment. Blood was taken before the meal and at selected time points within the following 8 h. Glucose, when added to a fat load, induced an increase of glycemia and insulinemia and, surprisingly, a 20 % reduction in the response of both total and active glucagon-like peptide-1 (GLP-1) concentration. The addition of glucose did not affect the magnitude of postprandial triglyceridemia and TRL-C and TRL-TG concentrations but stimulated a faster response of chylomicrons to the test meal, evaluated by changes in apolipoprotein B-48 concentrations. The addition of glucose induced the physiological response of insulin and the lower response of GLP-1 to the test meal during the early postprandial phase, but had no effect on changes of TRL-cholesterol and TRL-TG within 8 h after the meal.

  12. Association between Advanced Glycation End Products and Impaired Fasting Glucose: Results from the SALIA Study

    PubMed Central

    Teichert, Tom; Hellwig, Anne; Peßler, Annette; Hellwig, Michael; Vossoughi, Mohammad; Sugiri, Dorothea; Vierkötter, Andrea; Schulte, Thomas; Freund, Juliane; Roden, Michael; Hoffmann, Barbara; Schikowski, Tamara; Luckhaus, Christian; Krämer, Ursula; Henle, Thomas; Herder, Christian

    2015-01-01

    Advanced glycation end products (AGEs) may contribute to the development of type 2 diabetes and related complications, whereas their role in the early deterioration of glycaemia is unknown. While previous studies used antibody-based methods to quantify AGEs, data from tandem mass spectrometry coupled liquid chromatography (LC-MS/MS)-based measurements are limited to patients with known diabetes. Here, we used the LC-MS/MS method to test the hypothesis that plasma AGE levels are higher in individuals with impaired fasting glucose (IFG) than in those with normal fasting glucose (NFG). Secondary aims were to assess correlations of plasma AGEs with quantitative markers of glucose metabolism and biomarkers of subclinical inflammation. This study included on 60 women with NFG or IFG (n = 30 each, mean age 74 years) from the German SALIA cohort. Plasma levels of free metabolites (3-deoxyfructose, 3-deoxypentosone, 3-deoxypentulose), two hydroimidazolones, oxidised adducts (carboxymethyllysine, carboxyethyllysine, methionine sulfoxide) and Nε-fructosyllysine were measured using LC-MS/MS. Plasma concentrations of all tested AGEs did not differ between the NFG and IFG groups (all p>0.05). Associations between plasma levels of AGEs and fasting glucose, insulin and HOMA-IR as a measure of insulin resistance were weak (r between -0.2 and 0.2, all p>0.05). The association between 3-deoxyglucosone-derived hydroimidazolone with several proinflammatory biomarkers disappeared upon adjustment for multiple testing. In conclusion, plasma AGEs assessed by LC-MS/MS were neither increased in IFG nor associated with parameters of glucose metabolism and subclinical inflammation in our study. Thus, these data argue against strong effects of AGEs in the early stages of deterioration of glucose metabolism. PMID:26018950

  13. A kinetics modeling study on the inhibition of glucose on cellulosome of Clostridium thermocellum.

    PubMed

    Zhang, Pengcheng; Wang, Buyun; Xiao, Qunfang; Wu, Shan

    2015-08-01

    A simplified kinetics model was built to study the inhibition of glucose on cellulosome of Clostridium thermocellum. Suitable reaction conditions were adopted to evaluate the model. The model was evaluated at different temperatures and further with various activated carbon additions as adsorbent for glucose. Investigation results revealed that the model could describe the hydrolysis kinetics of cellulose by cellulosome quite well. Glucose was found to be an inhibitor for cellulosome based on the kinetics analysis. Inhibition increased with the increase in temperature. Activated carbon as adsorbent could lower the inhibition. Parameters in the model were further discussed based on the experiment. The model might also be used to describe the strong inhibition of cellobiose on cellulosome. Saccharification of cellulose by both cellulosome and C. thermocellum could be enhanced efficiently by activated carbon addition.

  14. OCT Study of Optical Clearing of Muscle Tissue in vitro with 40% Glucose Solution

    NASA Astrophysics Data System (ADS)

    Genina, E. A.; Bashkatov, A. N.; Kozintseva, M. D.; Tuchin, V. V.

    2016-01-01

    The technique of -optical clearing of biological tissues- is aimed at improving the quality of visualization of structures hidden deep in tissue. In this study, we measured the diffusion coefficient of glucose in bovine skeletal muscle tissue by optical coherence tomography (OCT) in vitro and determined changes that took place in the imaging contrast of muscle fibers, the optical depth of coherent probing, and detection under the influence of aqueous 40% solution of glucose. It was shown that, within 90 min, when the depth of coherent probing increased by 14%, the contrast of OCT images increased fourfold and the depth of coherent detection of structural elements of the tissue increased by 2.4 times. The diffusion coefficient of glucose in the muscle tissue was (2.98 ± 0.94) × 10-6 cm2/s.

  15. [HbA1c is not enough in screening for impaired glucose metabolism. Glucose tolerance tests are also needed, as shown in Swedish prospective epidemiological study].

    PubMed

    Hellgren, Margareta; Daka, Bledar; Larsson, Charlotte

    2015-09-29

    An HbA1c threshold of ≥ 42 mmol/mol has been proposed to diagnose prediabetes. The sensitivity, specificity and positive predictive value of the proposed threshold for detection of individuals with prediabetes was examined in a study of 573 randomly selected individuals from Vara and Skövde. In addition, the utility of the FINDRISC questionnaire and of a fasting glucose test in combination with three short questions concerning BMI, heredity for type 2 diabetes and known hypertension was examined. Results from an oral glucose tolerance test were used as reference. The sensitivity of HbA1c and FINDRISC to detect individuals with IGT was 16 and 26 per cent respectively. Questions regarding BMI, heredity and hypertension together with a fasting glucose test yielded a sensitivity of 50%, but a lower specificity and positive predictive value. We conclude that HbA1c inefficiently detected individuals with impaired glucose tolerance and that oral glucose tolerance tests can still preferably be recommended.

  16. Effects of luseogliflozin, a sodium-glucose co-transporter 2 inhibitor, on 24-h glucose variability assessed by continuous glucose monitoring in Japanese patients with type 2 diabetes mellitus: a randomized, double-blind, placebo-controlled, crossover study.

    PubMed

    Nishimura, R; Osonoi, T; Kanada, S; Jinnouchi, H; Sugio, K; Omiya, H; Ubukata, M; Sakai, S; Samukawa, Y

    2015-08-01

    The aim of the present study was to determine the effects of luseogliflozin on 24-h glucose levels, assessed by continuous glucose monitoring, and on pharmacodynamic variables measured throughout the day. In this double-blind, placebo-controlled, crossover study, 37 patients with type 2 diabetes mellitus inadequately controlled with diet and exercise were randomized into two groups. Patients in each group first received luseogliflozin then placebo for 7 days each, or vice versa. After 7 days of treatment, the mean 24-h glucose level was significantly lower with luseogliflozin than with placebo [mean (95% confidence interval) 145.9 (134.4-157.5) mg/dl vs 168.5 (156.9-180.0) mg/dl; p < 0.001]. The proportion of time spent with glucose levels ≥70 to ≤180 mg/dl was significantly greater with luseogliflozin than with placebo [median (interquartile range) 83.2 (67.7-96.5)% vs 71.9 (46.9-83.3)%; p < 0.001] without inducing hypoglycaemia. The decrease in glucose levels was accompanied by reductions in serum insulin levels throughout the day.

  17. A Human Pilot Study of the Fluorescence Affinity Sensor for Continuous Glucose Monitoring in Diabetes

    PubMed Central

    Dutt-Ballerstadt, Ralph; Evans, Colton; Pillai, Arun P.; Orzeck, Eric; Drabek, Rafal; Gowda, Ashok; McNichols, Roger

    2012-01-01

    Objective We report results of a pilot clinical study of a subcutaneous fluorescence affinity sensor (FAS) for continuous glucose monitoring conducted in people with type 1 and type 2 diabetes. The device was assessed based on performance, safety, and comfort level under acute conditions (4 h). Research Design and Methods A second-generation FAS (BioTex Inc., Houston, TX) was subcutaneously implanted in the abdomens of 12 people with diabetes, and its acute performance to excursions in blood glucose was monitored over 4 h. After 30–60 min the subjects, who all had fasting blood glucose levels of less than 200 mg/dl, received a glucose bolus of 75 g/liter dextrose by oral administration. Capillary blood glucose samples were obtained from the finger tip. The FAS data were retrospectively evaluated by linear least squares regression analysis and by the Clarke error grid method. Comfort levels during insertion, operation, and sensor removal were scored by the subjects using an analog pain scale. Results After retrospective calibration of 17 sensors implanted in 12 subjects, error grid analysis showed 97% of the paired values in zones A and B and 1.5% in zones C and D, respectively. The mean absolute relative error between sensor signal and capillary blood glucose was 13% [±15% standard deviation (SD), 100–350 mg/dl] with an average correlation coefficient of 0.84 (±0.24 SD). The actual average “warm-up” time for the FAS readings, at which highest correlation with glucose readings was determined, was 65 (±32 SD) min. Mean time lag was 4 (±5 SD) min during the initial operational hours. Pain levels during insertion and operation were modest. Conclusions The in vivo performance of the FAS demonstrates feasibility of the fluorescence affinity technology to determine blood glucose excursions accurately and safely under acute dynamic conditions in humans with type 1 and type 2 diabetes. Specific engineering challenges to sensor and instrumentation robustness

  18. Direct Evidence of Acetaminophen Interference with Subcutaneous Glucose Sensing in Humans: A Pilot Study

    PubMed Central

    Basu, Ananda; Veettil, Sona; Dyer, Roy; Peyser, Thomas

    2016-01-01

    Abstract Background: Recent advances in accuracy and reliability of continuous glucose monitoring (CGM) devices have focused renewed interest on the use of such technology for therapeutic dosing of insulin without the need for independent confirmatory blood glucose meter measurements. An important issue that remains is the susceptibility of CGM devices to erroneous readings in the presence of common pharmacologic interferences. We report on a new method of assessing CGM sensor error to pharmacologic interferences using the example of oral administration of acetaminophen. Materials and Methods: We examined the responses of several different Food and Drug Administration–approved and commercially available CGM systems (Dexcom [San Diego, CA] Seven® Plus™, Medtronic Diabetes [Northridge, CA] Guardian®, and Dexcom G4® Platinum) to oral acetaminophen in 10 healthy volunteers without diabetes. Microdialysis catheters were placed in the abdominal subcutaneous tissue. Blood and microdialysate samples were collected periodically and analyzed for glucose and acetaminophen concentrations before and after oral ingestion of 1 g of acetaminophen. We compared the response of CGM sensors with the measured acetaminophen concentrations in the blood and interstitial fluid. Results: Although plasma glucose concentrations remained constant at approximately 90 mg/dL (approximately 5 mM) throughout the study, CGM glucose measurements varied between approximately 85 to 400 mg/dL (from approximately 5 to 22 mM) due to interference from the acetaminophen. The temporal profile of CGM interference followed acetaminophen concentrations measured in interstitial fluid (ISF). Conclusions: This is the first direct measurement of ISF concentrations of putative CGM interferences with simultaneous measurements of CGM performance in the presence of the interferences. The observed interference with glucose measurements in the tested CGM devices coincided temporally with appearance of

  19. Whole body glucose kinetics in type I diabetes studied with (6,6-/sup 2/H) and (U-/sup 13/C)-glucose and the artificial B-cell

    SciTech Connect

    Darmaun, D.; Cirillo, D.; Koziet, J.; Chauvet, D.; Young, V.R.; Robert, J.J.

    1988-05-01

    Dynamic aspects of whole body glucose metabolism were assessed in ten young adult insulin-dependent (type I) diabetic men. Using a primed, continuous intravenous infusion of (6,6-/sup 2/H)glucose and (U-/sup 13/C)glucose, endogenous production, tissue uptake, carbon recycling, and oxidation of glucose were measured in the postabsorptive state. These studies were undertaken after blood glucose had been maintained overnight at 5.9 +/- 0.4 mmol/L (n = 10), and on another night at 10.5 +/- 0.4 mmol/L (n = 4) or 15.2 +/- 0.6 mmol/L (n = 6). In the normoglycemic state, endogenous glucose production averaged 2.15 +/- 0.13 mg x kg-1 x min-1. This value, as well as the rate of glucose carbon recycling (0.16 +/- 0.04 mg x kg-1 x min-1) and glucose oxidation (1.52 +/- 0.16 mg x kg-1 x min-1) are comparable to those found in nondiabetic controls. In the hyperglycemic states at 10 or 15 mmol/L, endogenous glucose production was increased by 11% (P less than .01) and 60% (P less than .01) compared to the normoglycemic states, respectively. Glucose carbon recycling contributed only a small percentage to this variation in glucose production (15% at the 15 mmol/L glucose level). This suggests that if gluconeogenesis participates in the increased glucose output, it is not dependent on a greater systemic supply of three-carbon precursors. The increased rate of glucose production in the hyperglycemic state was quantitatively offset by a rise in urinary glucose excretion. Glucose tissue uptake, as well as glucose oxidation, did not vary between normoglycemic and hyperglycemic states.

  20. A prospective study of impaired fasting glucose and type 2 diabetes in China

    PubMed Central

    Vaidya, Anand; Cui, Liufu; Sun, Lixia; Lu, Bing; Chen, Shuohua; Liu, Xing; Zhou, Yong; Liu, Xiurong; Xie, Xiaobing; Hu, Frank B.; Wu, Shouling; Gao, Xiang

    2016-01-01

    Abstract The worldwide prevalence and incidence of diabetes and obesity are increasing in pandemic proportions. This is particularly relevant for China, where an extremely large population is growing, aging, and urbanizing. We thus conducted a prospective study to examine the prevalence and incidence of impaired fasting glucose (IFG) and diabetes, the rate at which fasting blood glucose rises, and the major modifiable risk factors associated with these outcomes in a large Chinese population from the Kailuan prospective study. A prospective cohort included 100,279 Chinese participants, aged 18 years or more, who had available information on fasting blood glucose concentrations at the start of the study (2006). Examination surveys were conducted every 2 years in 2008 and 2010. For the analyses of incident diabetes, we included 76,869 participants who were free of diabetes, cardiovascular disease, and cancer at the baseline and participants in the 2008 and/or 2010 follow-up. Diabetes was defined by a fasting blood glucose concentration ≥7 mmol/L, self-reported history, or active treatment with insulin or any oral hypoglycemic agent. IFG was defined by a fasting blood glucose concentration between 5.6 and 6.9 mmol/L. During the 4-year study, the prevalence of diabetes and IFG rose from 6.6% to 7.7%, and 17.3% to 22.6%, respectively. There were 17,811 incident cases of IFG and 4867 incident cases of diabetes. The age-standardized incident rate of IFG and diabetes were 62.6/1000 person-years (51.2/1000 person-years in women and 73.8/1000 person-years in men) and 10.0/1000 person-years (7.8/1000 person-years in women and 12.1/1000 person-years in men), respectively. We observed steady increases in fasting blood glucose with body anthropometrics and in every defined category of body mass index, including in those traditionally considered to be well within the “normal” range. In this large longitudinal study of Chinese adults, we observed a high prevalence and

  1. The study of serum vitamin d and insulin resistance in chinese populations with normal glucose tolerance.

    PubMed

    Ding, Lin; Wang, Congcong; Ma, Heliang; Tian, Yuling; Lu, Yong; Pang, Shuguang

    2014-01-01

    Objectives. The aim of this study was to investigate the relationship between serum vitamin D and insulin resistance in Chinese subjects without diabetes mellitus. Methods. Serum 25(OH)D was measured in 897 individuals with normal glucose tolerance (NGT). Oral glucose tolerance tests (OGTTs) were conducted to exclude cases with diabetes, impaired fasting glucose (IFG), and impaired glucose tolerance (IGT). Metabolic parameters were measured and compared between the highest and lowest 25(OH)D quartiles. The relationship between serum 25(OH)D and homeostatic model assessment-insulin resistance (HOMA-IR) was analyzed. Results. Indexes, such as HOMA-IR, FINS, and SBP, were negatively correlated with serum 25(OH)D concentrations. Compared with the lowest quartile, individuals in the highest group had decreased Lg (HOMA-IR), Lg (FINS), and SBP. Pearson correlation analyses showed that serum 25(OH)D was negatively associated with age, BMI, Lg (HOMA-IR), and Lg (FINS). Multivariate linear regression analysis confirmed the negative correlation of Lg (HOMA-IR) and 25(OH)D. Conclusions. This study showed that serum 25(OH)D could be regarded as an independent predictor of insulin resistance for subjects without diabetes mellitus in China. Adequate vitamin D supplementation may improve multiple metabolic disturbances.

  2. Study of the effects of tissue reactions on the function of implanted glucose sensors.

    PubMed

    Dungel, Paul; Long, Nathan; Yu, Bazhang; Moussy, Yvonne; Moussy, Francis

    2008-06-01

    The relationship between tissue reactions to a subcutaneously implanted glucose sensor and the function of the sensor was evaluated over a period of 4-weeks using tubular, porous polyvinyl alcohol (PVA) sponges implanted subcutaneously in rats. The PVA sponges were used as scaffolds in which the foreign body response could develop. Coil-type glucose sensors were then placed in the center of the PVA sponges and tested on day 3, and weekly thereafter. In the first approach, the sensors were placed in the sponges still implanted in the rats and tested. In vivo glucose sensor sensitivity peaked at day 7 and steadily decreased until day 35. In the second approach, the sensors were placed in the explanted sponges and then tested. This test showed no sensor function after day 7, indicating that functional blood vessels are critical in maintaining any function whatsoever. In both cases the sensors themselves were never implanted to eliminate any potential in vivo degradation of the sensors that could have affected the outcome of this study. Sensors were then tested in absence of sponges and found to be working properly with no change from preimplantation sensitivity. Once sensor testing was concluded, the PVA sponge/tissue samples were prepared for quantitative histological analysis. It was determined that the increase in collagen deposition within the sponge correlated with the decrease in sensor sensitivity. It was also observed that natural angiogenesis (peak at day 14) did not overcome the barrier to glucose diffusion created by the fibrous capsule.

  3. A Closed-Loop Artificial Pancreas Using a Proportional Integral Derivative with Double Phase Lead Controller Based on a New Nonlinear Model of Glucose Metabolism

    PubMed Central

    Abbes, Ilham Ben; Richard, Pierre-Yves; Lefebvre, Marie-Anne; Guilhem, Isabelle; Poirier, Jean-Yves

    2013-01-01

    Background Most closed-loop insulin delivery systems rely on model-based controllers to control the blood glucose (BG) level. Simple models of glucose metabolism, which allow easy design of the control law, are limited in their parametric identification from raw data. New control models and controllers issued from them are needed. Methods A proportional integral derivative with double phase lead controller was proposed. Its design was based on a linearization of a new nonlinear control model of the glucose–insulin system in type 1 diabetes mellitus (T1DM) patients validated with the University of Virginia/Padova T1DM metabolic simulator. A 36 h scenario, including six unannounced meals, was tested in nine virtual adults. A previous trial database has been used to compare the performance of our controller with their previous results. The scenario was repeated 25 times for each adult in order to take continuous glucose monitoring noise into account. The primary outcome was the time BG levels were in target (70–180 mg/dl). Results Blood glucose values were in the target range for 77% of the time and below 50 mg/dl and above 250 mg/dl for 0.8% and 0.3% of the time, respectively. The low blood glucose index and high blood glucose index were 1.65 and 3.33, respectively. Conclusion The linear controller presented, based on the linearization of a new easily identifiable nonlinear model, achieves good glucose control with low exposure to hypoglycemia and hyperglycemia. PMID:23759403

  4. Effect of Insulin Feedback on Closed-Loop Glucose Control: A Crossover Study

    PubMed Central

    Ruiz, Jessica L.; Sherr, Jennifer L.; Cengiz, Eda; Carria, Lori; Roy, Anirban; Voskanyan, Gayane; Tamborlane, William V.; Weinzimer, Stuart A.

    2012-01-01

    Background Closed-loop (CL) insulin delivery systems utilizing proportional-integral-derivative (PID) controllers have demonstrated susceptibility to late postprandial hypoglycemia because of delays between insulin delivery and blood glucose (BG) response. An insulin feedback (IFB) modification to the PID algorithm has been introduced to mitigate this risk. We examined the effect of IFB on CL BG control. Methods Using the Medtronic ePID CL system, four subjects were studied for 24 h on PID control and 24 h during a separate admission with the IFB modification (PID + IFB). Target glucose was 120 mg/dl; meals were served at 8:00 AM, 1:00 PM, and 6:00 PM and were identical for both admissions. No premeal manual boluses were given. Reference BG excursions, defined as incremental glucose rise from premeal to peak, and postprandial BG area under the curve (AUC; 0–5 h) were compared. Results are reported as mean ± standard deviation. Results The PID + IFB control resulted in higher mean BG levels compared with PID alone (153 ± 54 versus 133 ± 56 mg/dl; p < .0001). Postmeal BG excursions (114 ± 28 versus 114 ± 47 mg/dl) and AUCs (285 ± 102 versus 255 ± 129 mg/dl/h) were similar under both conditions. Total insulin delivery averaged 57 ± 20 U with PID versus 45 ± 13 U with PID + IFB (p = .18). Notably, eight hypoglycemic events (BG < 60 mg/dl) occurred during PID control versus none during PID + IFB. Conclusions Addition of IFB to the PID controller markedly reduced the occurrence of hypoglycemia without increasing meal-related glucose excursions. Higher average BG levels may be attributable to differences in the determination of system gain (Kp) in this study. The prevention of postprandial hypoglycemia suggests that the PID + IFB algorithm may allow for lower target glucose selection and improved overall glycemic control. PMID:23063039

  5. Dose-response study of sajabalssuk ethanol extract from Artemisia princeps Pampanini on blood glucose in subjects with impaired fasting glucose or mild type 2 diabetes.

    PubMed

    Choi, Ji-Young; Shin, Su-Kyung; Jeon, Seon-Min; Baek, Nam-In; Chung, Hae-Gon; Jeong, Tae-Sook; Lee, Kyung Tae; Lee, Mi-Kyung; Choi, Myung-Sook

    2011-01-01

    Previously we reported that an ethanol extract from Artemisia princeps Pampanini lowered blood glucose in db/db mice. Here we report a preliminary study in which the blood glucose-lowering effects of two different doses of sajabalssuk ethanol extract (SBE), containing eupatilin and jaseocidin, were examined in hyperglycemic subjects with fasting blood glucose (FBG) levels of 100-150 mg/dL. Subjects were randomized into four groups: negative control (2,000 mg of lactose /day), positive control (1,140 mg of pinitol/day), low-dose SBE (2,000 mg of SBE/day), and high-dose SBE (4,000 mg of SBE/day). After 8 weeks of supplementation, FBG and glycosylated hemoglobin levels were significantly lowered in low-and high-dose SBE groups compared to the baseline values; high-dose SBE also resulted in significantly lower plasma free fatty acid levels and systolic blood pressure. This study demonstrated that supplementation of 2 g or 4 g of SBE daily can significantly reduce blood glucose in hyperglycemic subjects, although high-dose SBE seemed to be more effective than low-dose SBE for lowering plasma free fatty acid level and systolic blood pressure.

  6. Centrifuge workers study. Phase II, completion report

    SciTech Connect

    Wooten, H.D.

    1994-09-01

    Phase II of the Centrifuge Workers Study was a follow-up to the Phase I efforts. The Phase I results had indicated a higher risk than expected among centrifuge workers for developing bladder cancer when compared with the risk in the general population for developing this same type of cancer. However, no specific agent could be identified as the causative agent for these bladder cancers. As the Phase II Report states, Phase I had been limited to workers who had the greatest potential for exposure to substances used in the centrifuge process. Phase II was designed to expand the survey to evaluate the health of all employees who had ever worked in Centrifuge Program Departments 1330-1339 but who had not been interviewed in Phase I. Employees in analytical laboratories and maintenance departments who provided support services for the Centrifuge Program were also included in Phase II. In December 1989, the Oak Ridge Associated Universities (ORAU), now known as Oak Ridge Institute for Science and Education (ORISE), was contracted to conduct a follow-up study (Phase II). Phase H of the Centrifuge Workers Study expanded the survey to include all former centrifuge workers who were not included in Phase I. ORISE was chosen because they had performed the Phase I tasks and summarized the corresponding survey data therefrom.

  7. TDRSS telecommunications study, phase 2

    NASA Technical Reports Server (NTRS)

    Cahn, C. R.

    1974-01-01

    Providing an extension to parametric analysis of the telecommunications support capability of the Tracking and Data Relay Satellite System (TDRSS), this phase considers candidate modulation waveforms which could meet the shuttle telecommunications requirements and also be compatible with the TDRSS single access S-band service. In addition, it considers the feasibility of modifying a single access S-band user transponder for operation with conventional STDN signals emanating from remotely located ground stations.

  8. High incidence of abnormal glucose metabolism in acute coronary syndrome patients at a moderate altitude: A sub-Himalayan study

    PubMed Central

    Mokta, Jitender; Kumar, Subash; Ganju, Neeraj; Mokta, Kiran; Panda, Prashant Kumar; Gupta, Swatantra

    2017-01-01

    Background: Abnormal glucose metabolic status at admission is an important marker of future cardiovascular events and long-term mortality after acute coronary syndrome (ACS), whether or not they are known diabetics. Objective: The aims were to study the prevalence of abnormal glucose metabolism in ACS patients and to compare the different methods of diagnosing diabetes in ACS patients. Methods: We did a prospective study. About 250 consecutive nondiabetic patients (200 men and 50 women) with ACS admitted to a tertiary care institute of Himachal Pradesh in 1 year were enrolled. Admission plasma glucose, next morning fasting plasma glucose (FPG), A1C, and a standardized 75-g oral glucose tolerance test (OGTT) 72 h after admission were done. Glucose metabolism was categorized as normal glucose metabolism, impaired glucose metabolism (impaired fasting glucose or impaired glucose tolerance [IGT]), and diabetes. Diabetes was arbitrarily classified further as undiagnosed (HBA1c ≥6.5%) or possibly stress diabetes (HBA1c <6.5%). A repeat OGTT after 3 months in objects with IGT and stress hyperglycemia at a time of admission was done. Results: The mean age was 54 ± 12.46 years. The mean plasma glucose at admission was 124 ± 53.96 mg/dL, and the mean FPG was 102 ± 27.07 mg/dL. The mean 2-h postglucose load concentration was 159.5 ± 56.58 mg/dL. At baseline, 95 (38%) had normal glucose metabolism, 95 (38%) had impaired glucose metabolism (IGT and or IGT) and 60 (24%) had diabetes; 48 (19.2%) were undiagnosed diabetes and 12 (4.8%) had stress hyperglycemia. At follow up 58.66% and 55.55% of patients with impaired glucose tolerance and stress hyperglycemia continued to have impaired glucose tolerance respectively. About 75 gm OGTT has highest sensitivity and specificity to diagnose diabetes, whereas A1C most specific to rule out stress hyperglycemia. Conclusions: In this small hilly state of India, abnormal glucose metabolism (previously undiagnosed diabetes and IGT) is

  9. Isolation of two cell populations from yeast during high-level alcoholic fermentation that resemble quiescent and nonquiescent cells from the stationary phase on glucose.

    PubMed

    Benbadis, Laurent; Cot, Marlène; Rigoulet, Michel; Francois, Jean

    2009-12-01

    High-level production of bioethanol (140 g L(-1) in 45 h) in aerated fed-batch cultures of Saccharomyces cerevisiae was shown to be linked to the length of a production phase uncoupled to the growth. The induction of this phase was characterized by metabolic and morphologic changes reminiscent of those occurring in the stationary phase of growth on glucose. Global transcriptomic analysis of ethanol-stressed yeast cells in the uncoupling phase harboured features similar to those from stationary-phase cells on glucose. Two distinct cellular populations were isolated by Percoll density-gradient centrifugation in this uncoupling phase. The lower fraction was enriched by yeast cells that were mostly uniform in size and opalescent, containing a large amount of glycogen and trehalose, and exhibiting high respiratory activity. In contrast, the upper fraction was characterized by cells heterogeneous in size, with one to several small buds, which did not contain storage carbohydrates and which exhibited a poor respiratory competence while retaining a high relative glycolytic activity. These results are discussed in terms of a possible induction of a state similar to the quiescence state previously observed from yeast stationary-phase cultures, in response to ethanol toxicity, whose acquisition may be critical for performing high-level alcoholic fermentation.

  10. Effect of a high glucose diet on insulin binding and insulin action in rat adipocytes. A longitudinal study.

    PubMed

    Oka, Y; Akanuma, Y; Kasuga, M; Kosaka, K

    1980-11-01

    To elucidate the mechanisms whereby changes in dietary composition affect the action of insulin on glucose metabolism, insulin binding and glucose uptake and oxidation have been studied in epididymal fat pad adipocytes from rats fed high glucose diets for 5 and 10 days. After 5 days, insulin binding was increased, the mainly to an increased number of receptors (3.4 X 10(5) vs. 2.4 X 10(5) sites per cell) in spite of increased plasma insulin levels (3.0 +/- 0.2 vs. 2.1 +/- 0.1 microgram/l; P < 0.05). The maximal response of glucose oxidation to insulin was increased (925 +/- 55 vs. 510 +/- 58 n moles/2 X 10(5) cells/2h; P < 0.01) and the dose-response curve of glucose uptake was shifted to the left. After 10 days, receptor number decreased to the control level and the effect of insulin on glucose uptake and oxidation (% basal) were similar to controls. Thus, in the early stage of high glucose feeding, insulin receptor number, and insulin sensitivity of glucose uptake, and insulin responsiveness of glucose oxidation were increased.

  11. Effect of an Acute Bout of Kettlebell Exercise on Glucose Tolerance in Sedentary Men: A Preliminary Study

    PubMed Central

    GREENWALD, SAMANTHA; SEGER, EDWARD; NICHOLS, DAVID; RAY, ANDREW D.; RIDEOUT, TODD C.; GOSSELIN, LUC E.

    2016-01-01

    Impaired glucose tolerance can have significant health consequences. The purposes of this preliminary study were to examine whether a single session of kettlebell exercise improves acute post-exercise glucose tolerance in sedentary individuals, and whether it was as effective as high-intensity interval running. Six sedentary male subjects underwent a two-hour oral glucose tolerance test following three different conditions: 1) control (no exercise); 2) kettlebell exercise (2 sets of 7 exercises, 15 repetitions per exercise with 30 seconds rest between each exercise); or 3) high-intensity interval running (10 one-minute intervals at a workload corresponding to 90% VO2max interspersed with one-minute active recovery periods). Blood glucose and insulin levels were measured before (0 minutes), and 60 and 120 minutes after glucose ingestion. Both kettlebell and high-intensity interval running exercise significantly lowered blood glucose 60 minutes after glucose ingestion compared with control. However, there was no significant difference in blood glucose between the two exercise conditions at any time point. In addition, there were no significant differences in insulin concentration between high intensity interval running, kettlebell, and control conditions at all time points. Results indicate that an acute bout of kettlebell exercise is as effective as high intensity interval running at improving glucose tolerance in sedentary young men. PMID:27766136

  12. Effect of an Acute Bout of Kettlebell Exercise on Glucose Tolerance in Sedentary Men: A Preliminary Study.

    PubMed

    Greenwald, Samantha; Seger, Edward; Nichols, David; Ray, Andrew D; Rideout, Todd C; Gosselin, Luc E

    2016-01-01

    Impaired glucose tolerance can have significant health consequences. The purposes of this preliminary study were to examine whether a single session of kettlebell exercise improves acute post-exercise glucose tolerance in sedentary individuals, and whether it was as effective as high-intensity interval running. Six sedentary male subjects underwent a two-hour oral glucose tolerance test following three different conditions: 1) control (no exercise); 2) kettlebell exercise (2 sets of 7 exercises, 15 repetitions per exercise with 30 seconds rest between each exercise); or 3) high-intensity interval running (10 one-minute intervals at a workload corresponding to 90% VO2max interspersed with one-minute active recovery periods). Blood glucose and insulin levels were measured before (0 minutes), and 60 and 120 minutes after glucose ingestion. Both kettlebell and high-intensity interval running exercise significantly lowered blood glucose 60 minutes after glucose ingestion compared with control. However, there was no significant difference in blood glucose between the two exercise conditions at any time point. In addition, there were no significant differences in insulin concentration between high intensity interval running, kettlebell, and control conditions at all time points. Results indicate that an acute bout of kettlebell exercise is as effective as high intensity interval running at improving glucose tolerance in sedentary young men.

  13. DFTr optimization and DFTr-MD studies of glucose, ten explicit water molecules enclosed by an implicit solvent, COSMO

    Technology Transfer Automated Retrieval System (TEKTRAN)

    DFTr optimization studies are carried out on alpha/beta-glucose surrounded by ten explicit water molecules and the glucose/water super-molecule completely enclosed by an implicit solvation model, COSMO. Twenty one starting configurations of the explicit waters were first optimized empirically with t...

  14. Response of incretins (GIP and GLP-1) to an oral glucose load in female and male subjects with normal glucose tolerance.

    PubMed

    Matsuo, Toshihiro; Kusunoki, Yoshiki; Katsuno, Tomoyuki; Ikawa, Takashi; Akagami, Takafumi; Murai, Kazuki; Miuchi, Masayuki; Miyagawa, Jun-ichiro; Namba, Mitsuyoshi

    2014-11-01

    The aim of this study was to analyze the blood glucose profile and the response of incretins in healthy young subjects by the 75 g oral glucose tolerance test (OGTT). We first reported that plasma glucose and GIP levels were higher in males during the early phase of the OGTT.

  15. Studies of two phase flow

    NASA Technical Reports Server (NTRS)

    Witte, Larry C.

    1994-01-01

    The development of instrumentation for the support of research in two-phase flow in simulated microgravity conditions was performed. The funds were expended in the development of a technique for characterizing the motion and size distribution of small liquid droplets dispersed in a flowing gas. Phenomena like this occur in both microgravity and normal earth gravity situations inside of conduits that are carrying liquid-vapor mixtures at high flow rates. Some effort to develop a conductance probe for the measurement of liquid film thickness was also expended.

  16. Association between DNA Methylation in Whole Blood and Measures of Glucose Metabolism: KORA F4 Study

    PubMed Central

    Wahl, Simone; Kunze, Sonja; Molnos, Sophie; Volkova, Nadezda; Schramm, Katharina; Carstensen-Kirberg, Maren; Waldenberger, Melanie; Gieger, Christian; Peters, Annette; Illig, Thomas; Prokisch, Holger; Roden, Michael; Grallert, Harald

    2016-01-01

    Epigenetic regulation has been postulated to affect glucose metabolism, insulin sensitivity and the risk of type 2 diabetes. Therefore, we performed an epigenome-wide association study for measures of glucose metabolism in whole blood samples of the population-based Cooperative Health Research in the Region of Augsburg F4 study using the Illumina HumanMethylation 450 BeadChip. We identified a total of 31 CpG sites where methylation level was associated with measures of glucose metabolism after adjustment for age, sex, smoking, and estimated white blood cell proportions and correction for multiple testing using the Benjamini-Hochberg (B-H) method (four for fasting glucose, seven for fasting insulin, 25 for homeostasis model assessment-insulin resistance [HOMA-IR]; B-H-adjusted p-values between 9.2x10-5 and 0.047). In addition, DNA methylation at cg06500161 (annotated to ABCG1) was associated with all the aforementioned phenotypes and 2-hour glucose (B-H-adjusted p-values between 9.2x10-5 and 3.0x10-3). Methylation status of additional three CpG sites showed an association with fasting insulin only after additional adjustment for body mass index (BMI) (B-H-adjusted p-values = 0.047). Overall, effect strengths were reduced by around 30% after additional adjustment for BMI, suggesting that this variable has an influence on the investigated phenotypes. Furthermore, we found significant associations between methylation status of 21 of the aforementioned CpG sites and 2-hour insulin in a subset of samples with seven significant associations persisting after additional adjustment for BMI. In a subset of 533 participants, methylation of the CpG site cg06500161 (ABCG1) was inversely associated with ABCG1 gene expression (B-H-adjusted p-value = 1.5x10-9). Additionally, we observed an enrichment of the top 1,000 CpG sites for diabetes-related canonical pathways using Ingenuity Pathway Analysis. In conclusion, our study indicates that DNA methylation and diabetes-related traits

  17. Effect of transcutaneous auricular vagus nerve stimulation on impaired glucose tolerance: a pilot randomized study

    PubMed Central

    2014-01-01

    Background Impaired glucose tolerance (IGT) is a pre-diabetic state of hyperglycemia that is associated with insulin resistance, increased risk of type II diabetes, and cardiovascular pathology. Recently, investigators hypothesized that decreased vagus nerve activity may be the underlying mechanism of metabolic syndrome including obesity, elevated glucose levels, and high blood pressure. Methods In this pilot randomized clinical trial, we compared the efficacy of transcutaneous auricular vagus nerve stimulation (taVNS) and sham taVNS on patients with IGT. 72 participants with IGT were single-blinded and were randomly allocated by computer-generated envelope to either taVNS or sham taVNS treatment groups. In addition, 30 IGT adults were recruited as a control population and not assigned treatment so as to monitor the natural fluctuation of glucose tolerance in IGT patients. All treatments were self-administered by the patients at home after training at the hospital. Patients were instructed to fill in a patient diary booklet each day to describe any side effects after each treatment. The treatment period was 12 weeks in duration. Baseline comparison between treatment and control group showed no difference in weight, BMI, or measures of systolic blood pressure, diastolic blood pressure, fasting plasma glucose (FPG), 2-hour plasma glucose (2hPG), or glycosylated hemoglobin (HbAlc). Results 100 participants completed the study and were included in data analysis. Two female patients (one in the taVNS group, one in the sham taVNS group) dropped out of the study due to stimulation-evoked dizziness. The symptoms were relieved after stopping treatment. Compared with sham taVNS, taVNS significantly reduced the two-hour glucose tolerance (F(2) = 5.79, p = 0.004). In addition, we found that taVNS significantly decreased (F(1) = 4.21, p = 0.044) systolic blood pressure over time compared with sham taVNS. Compared with the no-treatment control group, patients

  18. Altered cerebral glucose metabolism in an animal model of diabetes insipidus: a micro-PET study.

    PubMed

    Idbaih, Ahmed; Burlet, Arlette; Adle-Biassette, Homa; Boisgard, Raphaël; Coulon, Christine; Paris, Sophie; Marie, Yannick; Donadieu, Jean; Hoang-Xuan, Khê; Ribeiro, Maria-Joao

    2007-07-16

    The Brattleboro rat is an animal model of genetically induced central diabetes insipidus. These rats show cognitive and behavioral disorders, but no neurodegenerative disease has been observed. We studied brain glucose uptake, a marker of neuronal activity, in 6 Brattleboro rats, in comparison with 6 matched Long-Evans (LE) control rats. A group of 3 Brattleboro rats and 3 Long-Evans rats was studied in vivo and another group of animals was studied ex vivo. In vivo studies were performed using fluorodeoxyglucose labeled with fluorine 18 ((18)F-FDG) and a dedicated small-animal PET device. At 30 min and 60 min p.i., (18)F-FDG uptake was significantly higher in the frontal cortex, striatum, thalamus and cerebellum of Brattleboro rats than in LE rats when measured by PET in vivo (p<0.05), but only a trend towards higher values was found ex vivo. Our results show for the first time that brain glucose metabolism is modified in Brattleboro rats. This altered brain glucose metabolism in Brattleboro rats may be related to the observed cognitive and behavioral disorders. Functional analyses of brain metabolism are promising to investigate cognitive behavioral disturbances observed in Brattleboro rats and their link to diabetes insipidus.

  19. Diabetes, impaired glucose tolerance, and metabolic biomarkers in individuals with normal glucose tolerance are inversely associated with lung function: the Jackson Heart Study.

    PubMed

    Hickson, DeMarc A; Burchfiel, Cecil M; Liu, Jiankang; Petrini, Marcy F; Harrison, Kimystian; White, Wendy B; Sarpong, Daniel F

    2011-08-01

    The objectives of this study were to test the hypothesis that diabetes and impaired glucose tolerance (IGT), diabetes control and diabetes duration, and metabolic biomarkers in adults with normal glucose tolerance (NGT) are inversely associated with spirometry-measured lung function. We conducted a cross-sectional observational cohort study that included nonsmoking African American adults (n = 2,945; mean age = 52.5 ± 12.6 years; 69.2% female), who were free of cardiovascular disease, from the Jackson Heart Study. The interventions were diabetes, metabolic biomarkers and lung function. We measured the associations of glycemia with forced expiratory volume (FEV) in 1 s, FEV in 6 s, and vital capacity. Multivariable adjusted mean lung function values were lower among adults with diabetes and IGT (in women only, but not after adjustment for waist circumference) than adults with NGT. Among adults with diabetes, no associations were observed between lung function and diabetes control or duration. In women with NGT, lower lung function was consistently associated with higher glucose levels and less consistently with higher insulin levels and insulin resistance. Lower lung function was consistently associated with higher insulin levels and insulin resistance and less consistently associated with insulin and hemoglobin A1c in men with NGT. Overall, our findings generally support the hypothesis that diabetes, IGT, and increased levels of metabolic biomarkers in individuals with NGT are inversely associated with lung function in African Americans, independent of adiposity.

  20. Sensitive determination of glucose in Dulbecco's modified Eagle medium by high-performance liquid chromatography with 1-phenyl-3-methyl-5-pyrazolone derivatization: application to gluconeogenesis studies.

    PubMed

    Ling, Zhaoli; Xu, Ping; Zhong, Zeyu; Wang, Fan; Shu, Nan; Zhang, Ji; Tang, Xiange; Liu, Li; Liu, Xiaodong

    2016-04-01

    A new pre-column derivative high-performance liquid chromatography (HPLC) method for determination of d-glucose with 3-O-methyl-d-glucose (3-OMG) as the internal standard was developed and validated in order to study the gluconeogenesis in HepG2 cells. Samples were derivatized with 1-phenyl-3-methy-5-pyrazolone at 70°C for 50 min. Glucose and 3-OMG were extracted by liquid-liquid extraction and separated on a YMC-Triart C18 column, with a gradient mobile phase composed of acetonitrile and 20 mm ammonium acetate solution containing 0.09% tri-ethylamine at a flow rate of 1.0 mL/min. The eluate were detected using a UV detector at 250 nm. The assay was linear over the range 0.39-25 μm (R(2) = 0.9997, n = 5) and the lower limit of quantitation was 0.39 μm (0.070 mg/mL). Intra- and inter-day precision and accuracy were <15% and within ±3%, respectively. After validation, the HPLC method was applied to investigate the gluconeogenesis in Dulbecco's modified Eagle medium (DMEM) cultured HepG2 cells. Glucose concentration was determined to be about 1-2.5 μm in this gluconeogenesis assay. In conclusion, this method has been shown to determine small amounts of glucose in DMEM successfully, with lower limit of quantitation and better sensitivity when compared with common commercial glucose assay kits.

  1. Inflammatory Mediators and Glucose in Pregnancy: Results from a Subset of the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) Study

    PubMed Central

    Lowe, Lynn P.; Metzger, Boyd E.; Lowe, William L.; Dyer, Alan R.; McDade, Thomas W.; McIntyre, H. David

    2010-01-01

    Context: Inflammatory mediators are associated with type 2 and gestational diabetes. It is unknown whether there are associations with glucose in pregnant women with lesser degrees of hyperglycemia. Objective: The objective of the study was to examine associations of inflammatory mediators with maternal glucose levels and neonatal size in a subset of participants in the Hyperglycemia and Adverse Pregnancy Outcome (HAPO) Study. Design: Eligible pregnant women underwent a 75-g oral glucose tolerance test between 24 and 32 wk gestation, and levels of C-peptide, adiponectin, plasminogen activator inhibitor type 1 (PAI-1), C-reactive protein (CRP), and resistin were measured in fasting serum samples. Associations of inflammatory mediators with maternal glucose and with birth size were assessed using multiple linear regression analyses, adjusting for maternal body mass index (BMI), fasting C-peptide, and other potential confounders. Results: Mean levels of adiponectin declined, and PAI-1 and CRP increased across increasing levels of maternal glucose, BMI, and C-peptide. For example, for fasting plasma glucose less than 75 mg/dl and fasting plasma glucose of 90 mg/dl or greater, adiponectin was 22.5 and 17.4 μg/ml and PAI-1 was 30.9 and 34.2 ng/ml, respectively. Associations with 1- and 2-h plasma glucose remained significant for adiponectin (P < 0.001), PAI-1 (P < 0.05), and CRP (P < 0.01) after adjustment for BMI and C-peptide. Adiponectin and CRP were inversely associated with birth weight, sum of skinfolds and percent body fat, and PAI-1 with sum of skinfolds (all P < 0.05) after adjustment for confounders. Resistin was not associated with 1- or 2-h glucose or birth size. Conclusion: Levels of inflammatory mediators are associated with levels of maternal glucose in pregnant women without overt diabetes. PMID:20843942

  2. Cyclic voltammetry at TCNQ and TTF-TCNQ modified platinum electrodes: A study of the glucose oxidase/glucose and galactose oxidase/galactose systems

    SciTech Connect

    Hale, P.D.; Skotheim, T.A.

    1988-01-01

    Recent work has shown that the synthetic metal TTF-TCNQ can be used as an electrode material for the oxidation of enzymes containing the prosthetic group flavin adenine dinucleotide (FAD). This direct electron transfer (direct in the sense that oxygen is not a mediator) between reduced enzyme and electrode, a process which does not occur to any measurable extent at a typical metal electrode, is not very well understood. In the present work, electron transfer between reduced glucose oxidase and TTF-TCNQ is investigated using cyclic voltammetry, and it is also shown that TCNQ itself can mediate this electron transfer between the enzyme and a platinum electrode. In addition to the glucose oxidase studies, cyclic voltammetric experiments have been performed on the galactose oxidase system, which contains a copper redox center rather than FAD. The results of these experiments demonstrate that the catalytic ability of TTF-TCNQ in enzyme-based electrochemical sensors is quite general. 15 refs., 4 figs.

  3. Effects of some drugs on human erythrocyte glucose 6-phosphate dehydrogenase: an in vitro study.

    PubMed

    Akkemik, Ebru; Budak, Harun; Ciftci, Mehmet

    2010-12-01

    Inhibitory effects of some drugs on glucose 6-phosphate dehydrogenase from the erythrocytes of human have been investigated. For this purpose, at the beginning, erythrocyte glucose 6-phosphate dehydrogenase was purified 2256 times in a yield of 44.22% by using ammonium sulphate precipitation and 2', 5'-ADP Sepharose 4B affinity gel. Temperature of +4°C was maintained during the purification process. Enzyme activity was determined with the Beutler method by using a spectrophotometer at 340 nm. This method was utilized for all kinetic studies. Ketotifen, dacarbazine, thiocolchicoside, meloxicam, methotrexate, furosemide, olanzapine, methylprednizolone acetate, paricalcitol, ritodrine hydrochloride, and gadobenate-dimeglumine were used as drugs. All the drugs indicated the inhibitory effects on the enzyme. Ki constants for glucose 6-phosphate dehydrogenase were found by means of Lineweaver-Burk graphs. While methylprednizolone acetate showed competitive inhibition, the others displayed non-competitive inhibition. In addition, IC(50) values of the drugs were determined by plotting Activity% vs [I].

  4. Regional Cerebral Glucose Metabolism in Novelty Seeking and Antisocial Personality: A Positron Emission Tomography Study

    PubMed Central

    Park, So Hyeon; Park, Hyun Soo

    2016-01-01

    Novelty seeking (NS) and antisocial personality (ASP) are commonly exhibited by those who suffer from addictions, such as substance abuse. NS has been suggested to be a fundamental aspect of ASP. To investigate the neurobiological substrate of NS and ASP, we tested the relationship between regional cerebral glucose metabolism and the level of NS, determining the differences between individuals with and without ASP. Seventy-two healthy adults (43 males, mean age±SD=38.8±16.6 years, range=20~70 years; 29 females, 44.2±20.1 years, range=19~72 years) underwent resting-state brain positron emission tomography (PET) 40 minutes after 18F-fluorodeoxyglucose (FDG) injection. Within 10 days of the FDG PET study, participants completed Cloninger's 240-item Temperament and Character Inventory (TCI) to determine NS scores. Participants with and without ASP were grouped according to their TCI profiles. Statistical parametric mapping analysis was performed using the FDG PET and TCI profile data. NS scores positively correlated with metabolism in the left anterior cingulate gyrus and the insula on both sides of the brain and negatively correlated with metabolism in the right pallidum and putamen. Participants with ASP showed differences in cerebral glucose metabolism across various cortical and subcortical regions, mainly in the frontal and prefrontal areas. These data demonstrate altered regional cerebral glucose metabolism in individuals with NS and ASP and inform our understanding of the neurobiological substrates of problematic behaviors and personality disorders. PMID:27574485

  5. Glucose transformation to 5-hydroxymethylfurfural in acidic ionic liquid: A quantum mechanical study.

    PubMed

    Arifin; Puripat, Maneeporn; Yokogawa, Daisuke; Parasuk, Vudhichai; Irle, Stephan

    2016-01-30

    Isomerization and transformation of glucose and fructose to 5-hydroxymethylfurfural (HMF) in both ionic liquids (ILs) and water has been studied by the reference interaction site model self-consistent field spatial electron density distribution (RISM-SCF-SEDD) method coupled with ab initio electronic structure theory, namely coupled cluster single, double, and perturbative triple excitation (CCSD(T)). Glucose isomerization to fructose has been investigated via cyclic and open chain mechanisms. In water, the calculations support the cyclic mechanism of glucose isomerization; with the predicted activation free energy is 23.8 kcal mol(-1) at experimental condition. Conversely, open ring mechanism is more favorable in ILs with the energy barrier is 32.4 kcal mol(-1) . Moreover, the transformation of fructose into HMF via cyclic mechanism is reasonable; the calculated activation barriers are 16.0 and 21.5 kcal mol(-1) in aqueous and ILs solutions, respectively. The solvent effects of ILs could be explained by the decomposition of free energies and radial distribution functions of solute-solvent that are produced by RISM-SCF-SEDD.

  6. Effect of Guava in Blood Glucose and Lipid Profile in Healthy Human Subjects: A Randomized Controlled Study

    PubMed Central

    Rakavi, R; Mangaraj, Manaswini

    2016-01-01

    Introduction The fruit of Psidium guajava (P.guajava) is known to contain free sugars yet the fruit juice showed hypoglycaemic effect. Hypoglycaemic activity of guava leaves has been well documented but not for guava fruit. Aim So we aimed to evaluate the effect of ripe guava (with peel and without peel) fruit supplementation on blood glucose and lipid profile in healthy human subjects. Materials and Methods Randomized Controlled study undertaken in: 1) Baseline; 2) 6 weeks supplementation phase. Forty five healthy MBBS students were included and randomly enrolled into Group A, Group B and Group C. In Baseline phase: Fasting Plasma Glucose (FPG) and serum lipid profile was done in all 3 groups. Group A were supplemented with 400g of ripe guava with peel and group B without peel, for 6 weeks. Rest 15 treated as control i.e., Group C. Result Supplementation of ripe guava fruit with peel reduced BMI as well as blood pressure (p<0.05) in group A, whereas the FPG, Total cholesterol, Triglycerides were found significantly increased (p<0.05). Group B registered a significant fall (p<0.05) in BMI as well as blood pressure. Fall in FPG level after guava pulp supplementation was not significant. Serum Total cholesterol, Triglycerides and Low Density Lipoprotein Cholesterol (LDLc) levels decreased significantly (p<0.05) indicating that guava pulp without peel may have a favourable effect on lipid levels and blood sugar as well. Conclusion Guava fruit without peel is more effective in lowering blood sugar as well as serum total cholesterol, triglycerides and LDLc. It increases HDLc levels also. PMID:27790420

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

    PubMed

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

    2010-07-01

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

  8. Nursing Predictors Study, Phase One.

    ERIC Educational Resources Information Center

    Dean, Janet H.; Fischer, Susanne E.

    In an effort to identify the minimum qualifications necessary for an entering student to succeed in a selective admission Nursing Program at Saint Petersburg Junior College in Florida, a study was conducted of 424 generic nursing students who started the program in January 1988, August 1988, January 1989, and August 1989. A successful student was…

  9. School Safety Study: Phase I.

    ERIC Educational Resources Information Center

    Arora, Alka

    This report summarizes findings from a study concerned with Arizona school safety. The survey component highlights safety-related policy information across 300 schools; the interview component highlights school-safety perceptions of 64 staff across 16 schools. Various policies and programs that respond to internal and external threats to school…

  10. Postprandial glucose fluxes and insulin sensitivity during exercise: a study in healthy individuals.

    PubMed

    Schiavon, Michele; Hinshaw, Ling; Mallad, Ashwini; Dalla Man, Chiara; Sparacino, Giovanni; Johnson, Matthew; Carter, Rickey; Basu, Rita; Kudva, Yogish; Cobelli, Claudio; Basu, Ananda

    2013-08-15

    Quantifying the effect size of acute exercise on insulin sensitivity (SI(exercise)) and simultaneous measurement of glucose disappearance (R(d)), endogenous glucose production (EGP), and meal glucose appearance in the postprandial state has not been developed in humans. To do so, we studied 12 healthy subjects [5 men, age 37.1 ± 3.1 yr, body mass index 24.1 ± 1.1 kg/m², fat-free mass (FFM) 50.9 ± 3.9 kg] during moderate exercise at 50% V(O₂max) for 75 min, 120-195 min after a triple-tracer mixed meal consumed at time 0. Tracer infusion rates were adjusted to achieve constant tracer-to-tracee ratio and minimize non-steady-state errors. Glucose turnover was estimated by accounting for the nonstationary kinetics introduced by exercise. Insulin sensitivity index was calculated in each subject both in the absence [time (t) = 0-120 min, SI(rest)] and presence (t = 0-360 min, SI(exercise)) of physical activity. EGP at t = 0 min (13.4 ± 1.1 μM·kg FFM⁻¹·min⁻¹) fell at t = 120 min (2.4 ± 0.4 μM·kg FFM⁻¹·min⁻¹) and then rapidly rose almost eightfold at t = 180 min (18.2 ± 2.6 μM·kg FFM⁻¹·min⁻¹) before gradually falling at t = 360 min (10.6 ± 0.9 μM·kg FFM⁻¹·min⁻¹). R(d) rapidly peaked at t = 120 min at the start of exercise (89.5 ± 11.6 μM·kg FFM⁻¹·min⁻¹) and then gradually declined at t = 195 min (26.4 ± 3.3 μM·kg FFM⁻¹·min⁻¹) before returning to baseline at t = 360 min. SI(exercise) was significantly higher than SI(rest) (21.6 ± 3.7 vs. 12.5 ± 2.0 10⁻⁴ dl·kg⁻¹·min⁻¹ per μU/ml, P < 0.0005). Glucose turnover was estimated for the first time during exercise with the triple-tracer technique. Our results, applying state-of-the-art techniques, show that moderate exercise almost doubles postprandial insulin sensitivity index in healthy subjects.

  11. Effects of exercise and metformin on the prevention of glucose intolerance: a comparative study

    PubMed Central

    Molena-Fernandes, C.; Bersani-Amado, C. A.; Ferraro, Z. M.; Hintze, L. J.; Nardo, N.; Cuman, R. K. N.

    2015-01-01

    We aimed to evaluate the effects of aerobic exercise training (4 days) and metformin exposure on acute glucose intolerance after dexamethasone treatment in rats. Forty-two adult male Wistar rats (8 weeks old) were divided randomly into four groups: sedentary control (SCT), sedentary dexamethasone-treated (SDX), training dexamethasone-treated (DPE), and dexamethasone and metformin treated group (DMT). Glucose tolerance tests and in situ liver perfusion were undertaken on fasting rats to obtain glucose profiles. The DPE group displayed a significant decrease in glucose values compared with the SDX group. Average glucose levels in the DPE group did not differ from those of the DMT group, so we suggest that exercise training corrects dexamethasone-induced glucose intolerance and improves glucose profiles in a similar manner to that observed with metformin. These data suggest that exercise may prevent the development of glucose intolerance induced by dexamethasone in rats to a similar magnitude to that observed after metformin treatment. PMID:26421869

  12. Laser Studies of Gas Phase Radical Reactions.

    DTIC Science & Technology

    1989-01-01

    Acremonium chrysogenum , was prepared according to the published procedure [6]. This fungal enzyme had a specific activity of 0.023 IUmg1, and was estimated to...Dist-lbitionj Avdielbiity Codes jAvail atidjor Dist 6a A-I . p -1- Laser Studies of Gas Phase Radical Reactions G. Hancock Physical Chemistry...some additional experiments concerning the formation of carbene radicals in liquid phase enzyme cleavage studies are described. Keywords Laser

  13. Infrared spectroscopy used to study ice formation: the effect of trehalose, maltose, and glucose on melting.

    PubMed

    Zelent, B; Vanderkooi, J M

    2009-07-15

    We report the use of infrared (IR) spectroscopy to detect ice crystals in biological solutions. The method is based on the temperature dependence of the OH bending and stretch bands of water. By using mixtures of D(2)O and H(2)O, water's absorption bands can be made to be on-scale in transmission mode. Water's stretch band moves to lower frequency and sharpens with freezing, and the bending band goes to higher frequency and becomes less sharp. The technique is demonstrated for the study of the hysteresis of freezing in the presence of glucosyl sugars, namely glucose, maltose, and trehalose.

  14. New-onset diabetes after transplantation--role of oral glucose tolerance test for diagnosis and study of risk factors.

    PubMed

    Sahay, Manisha; Sahay, Rakesh K; Narayan, Girish

    2013-09-01

    To determine the role of the oral glucose tolerance test in the early detection of new-onset diabetes after transplantation (NODAT) and to compare the various risk factors and insulin kinetics in the transplant patients, we studied 41 live-related renal allograft recipients who were not diabetic before transplantation. Immunosuppression included triple drug therapy (cyclosporine, azathioprine and steroids) and rejection episodes were treated with methyl prednisolone (30 mg/kg IV × 3 days). All the study patients were subjected to an oral glucose tolerance test (OGTT) at Day 90 post-transplant and classified as having normal glucose tolerance (NGT), impaired fasting glucose (IFG), impaired glucose tolerance (IGT) and NODAT as per the World Health Organization guidelines. Insulin levels were also determined at 0, ½ hour, 1 hour and 2 hours during OGTT. NODAT was noted in 29.2% of the study patients, IFG in 4.8% of the study patients and NGT in 65.8% of the study patients. All the groups had normal fasting plasma glucose, but higher than normal insulin levels, suggesting insulin resistance. The patients with overt NODAT had, in addition, low fasting insulin (insulin secretory defect). OGTT may be used for the early detection of NODAT. Although insulin resistance is detected in the majority of post-transplant patients, NODAT also reveals also an insulin secretory defect.

  15. Inhibitory action of sphingosine, sphinganine and dexamethasone on glucose uptake: Studies with hydrogen peroxide and phorbol ester

    SciTech Connect

    Murray, D.K.; Hill, M.E.; Nelson, D.H. )

    1990-01-01

    The mechanism of the inhibitory action of glucocorticoids on glucose uptake is incompletely understood. Treatment with corticosteriods of cells in which glucose uptake is stimulated at insulin postbinding and postreceptor sites may clarify the site of the steroid inhibitory action. Hydrogen peroxide, which has been shown to stimulate the insulin receptor tyrosine kinase, and phorbol myristate acetate (PMA) which stimulates protein kinase C were, therefore, used as stimulators of glucose transport in this study. These studies demonstrate that dexamethasone and the sphingoid bases, sphinganine and sphingosine, inhibit glucose uptake that has been stimulated at either the receptor kinase or protein kinase C level in both 3T3-L1 and 3T3-C2 cells. These data confirm glucocorticoid inhibitory action at a post binding level and support the suggestion that some corticosteriod inhibitory effects may be mediated by an action on sphingolipid metabolism.

  16. Study on kinetics of glucose uptake by some species of plankton

    NASA Astrophysics Data System (ADS)

    Li, Wenquan; Wang, Xian; Zhang, Yaohua

    1993-03-01

    The rates of glucose uptake by some species of plankton were determined by3H-glucose tracer method. Experimental results indicated that the observed glucose uptake at natural seawater concentrations by Platymonas subcordiformis and Brachionus plicatilis was principally a metabolic process fitted with the Michaelis-Menten equation in the range of adaptive temperatures. Heterotrophic uptake by Platymonas subcordiformis was mainly dependent on diffusion at high glucose levels. The uptake by Brachionus plicatilis showed active transport even at high glucose levels, indicating its high heterotrophic activity. The uptake rate by Artemia salina was lower, and its V m/K ratio was lower than those of the other two species of plankton.

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

    PubMed

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

    2017-01-02

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

  18. Chronic stress, inflammation, and glucose regulation in U.S. Hispanics from the HCHS/SOL Sociocultural Ancillary Study.

    PubMed

    McCurley, Jessica L; Mills, Paul J; Roesch, Scott C; Carnethon, Mercedes; Giacinto, Rebeca E; Isasi, Carmen R; Teng, Yanping; Sotres-Alvarez, Daniela; Llabre, Maria M; Penedo, Frank J; Schneiderman, Neil; Gallo, Linda C

    2015-08-01

    Diabetes prevalence is rising rapidly, and diabetes disproportionately affects Hispanics and other underserved groups. Chronic stress may contribute to diabetes risk, but few studies have examined this relationship in U.S. Hispanics. We examined associations of chronic stress with fasting glucose, glucose tolerance, and glycosylated hemoglobin (HbA1c) in Hispanics without diabetes, and also assessed indirect effects of stress through inflammation (CRP). Participants were 3,923 men and women, aged 18-74, without diabetes, from the four U.S. field centers (Bronx, NY; Chicago, IL; Miami, FL; San Diego, CA) of the Hispanic Community Health Study/Study of Latinos (HCHS/SOL) Sociocultural Ancillary study. Participants completed a measure of chronic life stress and a physical exam with oral glucose tolerance test. In a multivariate regression analysis with adjustment for demographic and health covariates, higher chronic stress was related to higher fasting glucose (standardized regression coefficient: β = .09, p < .01), postload glucose (β = .07, p < .05), and HbA1c levels (β = .08, p < .01). However, there was no indirect effect of stress through inflammation. Findings suggest that higher chronic stress is associated with poorer glucose regulation in Hispanics, prior to the onset of a clinical diabetes diagnosis.

  19. Two phase detonation studies conducted in 1971

    NASA Technical Reports Server (NTRS)

    Nicholls, J. A.

    1972-01-01

    A report is presented describing the research conducted on five phases: (1) ignition of fuel drops by a shock wave and passage of a shock wave over a burning drop, (2) the energy release pattern of a two-phase detonation with controlled drop sizes, (3) the attenuation of shock and detonation waves passing over an acoustic liner, (4) experimental and theoretical studies of film detonations, and (5) a simplified analytical model of a rotating two-phase detonation wave in a rocket motor.

  20. Study Of Phase Separation In Glass

    NASA Technical Reports Server (NTRS)

    Neilson, George F.; Weinberg, Michael C.; Smith, Gary L.

    1989-01-01

    Report describes an experimental study of effect of hydroxide content on phase separation in soda/silica glasses. Ordinary and gel glasses melted at 1,565 degree C, and melts stirred periodically. "Wet" glasses produced by passing bubbles of N2 saturated with water through melts; "dry" glasses prepared in similar manner, except N2 dried before passage through melts. Analyses of compositions of glasses performed by atomic-absorption and index-of-refraction measurements. Authors conclude hydroxide speeds up phase separation, regardless of method (gel or ordinary) by which glass prepared. Eventually helps material scientists to find ways to control morphology of phase separation.

  1. Multicenter Observational Study of the First-Generation Intravenous Blood Glucose Monitoring System in Hospitalized Patients

    PubMed Central

    Bochicchio, Grant V.; Hipszer, Brian R.; Magee, Michelle F.; Bergenstal, Richard M.; Furnary, Anthony P.; Gulino, Angela M.; Higgins, Michael J.; Simpson, Peter C.; Joseph, Jeffrey I.

    2015-01-01

    Background: Current methods of blood glucose (BG) monitoring and insulin delivery are labor intensive and commonly fail to achieve the desired level of BG control. There is great clinical need in the hospital for a user-friendly bedside device that can automatically monitor the concentration of BG safely, accurately, frequently, and reliably. Methods: A 100-patient observation study was conducted at 6 US hospitals to evaluate the first generation of the Intravenous Blood Glucose (IVBG) System (Edwards Lifesciences LLC & Dexcom Inc). Device safety, accuracy, and reliability were assessed. A research nurse sampled blood from a vascular catheter every 4 hours for ≤ 72 hours and BG concentration was measured using the YSI 2300 STAT Plus Analyzer (YSI Life Sciences). The IVBG measurements were compared to YSI measurements to calculate point accuracy. Results: The IVBG systems logged more than 5500 hours of operation in 100 critical care patients without causing infection or inflammation of a vein. A total of 44135 IVBG measurements were performed in 100 patients with 30231 measurements from the subset of 75 patients used for accuracy analysis. In all, 996 IVBG measurements were time-matched with reference YSI measurements. These pairs had a mean absolute difference (MAD) of 11.61 mg/dl, a mean absolute relative difference (MARD) of 8.23%, 93% met 15/20% accuracy defined by International Organization for Standardization 15197:2003 standard, and 93.2% were in zone A of the Clarke error grid. The IVBG sensors were exposed to more than 200 different medications with no observable effect on accuracy. Conclusions: The IVBG system is an automated and user-friendly glucose monitoring system that provides accurate and frequent BG measurements with great potential to improve the safety and efficacy of insulin therapy and BG control in the hospital, potentially leading to improved clinical outcomes. PMID:26033922

  2. A systems biology approach to study glucose repression in the yeast Saccharomyces cerevisiae.

    PubMed

    Westergaard, Steen Lund; Oliveira, Ana Paula; Bro, Christoffer; Olsson, Lisbeth; Nielsen, Jens

    2007-01-01

    Glucose repression in the yeast Saccharomyces cerevisiae has evolved as a complex regulatory system involving several different pathways. There are two main pathways involved in signal transduction. One has a role in glucose sensing and regulation of glucose transport, while another takes part in repression of a wide range of genes involved in utilization of alternative carbon sources. In this work, we applied a systems biology approach to study the interaction between these two pathways. Through genome-wide transcription analysis of strains with disruption of HXK2, GRR1, MIG1, the combination of MIG1 and MIG2, and the parental strain, we identified 393 genes to have significantly changed expression levels. To identify co-regulation patterns in the different strains we applied principal component analysis. Disruption of either GRR1 or HXK2 were both found to have profound effects on transcription of genes related to TCA cycle and respiration, as well as ATP synthesis coupled proton transport, all displaying an increased expression. The hxk2Delta strain showed reduced overflow metabolism towards ethanol relative to the parental strain. We also used a genome-scale metabolic model to identify reporter metabolites, and found that there is a high degree of consistency between the identified reporter metabolites and the physiological effects observed in the different mutants. Our systems biology approach points to close interaction between the two pathways, and our metabolism driven analysis of transcription data may find a wider application for analysis of cross-talk between different pathways involved in regulation of metabolism.

  3. A comparative study on effect of metformin and metformin-conjugated nanotubes on blood glucose homeostasis in diabetic rats.

    PubMed

    Mirazi, Naser; Shoaei, Jamileh; Khazaei, Ardeshir; Hosseini, Abdolkarim

    2015-09-01

    Diabetes mellitus is one of the most prevalent metabolic disorders. Carbon nanotubes have the advantage to cross the plasma membrane without damaging the cells, improving the biological effect of a drug and reducing its side effects. In the present study, the effect of metformin and metformin-conjugated nanotubes was investigated on blood glucose level in the streptozotocin-induced male diabetic rats. Diabetes in the animals was induced with a single dose of streptozotocin (60 mg/kg; i.p.) and after 3 days the blood glucose was analyzed. Animals showing fasting blood glucose higher than 250 mg/dL were considered as diabetic rats. The animals were treated with metformin and metformin-conjugated nanotubes (150 mg/kg; p.o.) daily and every 48-h for 1 week. Changes in animals' serum blood glucose level were evaluated daily during the treatment period. The results of this study showed that metformin reduced blood glucose levels in diabetic animals. Metformin-conjugated nanotubes significantly reduced the blood glucose levels in diabetic rats (p < 0.01). There was no significant difference in blood glucose level between metformin and metformin-conjugated nanotubes groups (p > 0.05). However, when both formulations of metformin were administered every 48-h, metformin-conjugated nanotubes reduced glycaemia for a longer time than metformin alone (p < 0.001). This study showed that the metformin-conjugated nanotubes would be able to reduce the blood glucose, prolong drug delivery and efficacy duration in animals which were treated with metformin-conjugated nanotubes compared with metformin alone.

  4. A randomised study on the effects of fish protein supplement on glucose tolerance, lipids and body composition in overweight adults.

    PubMed

    Vikøren, Linn A; Nygård, Ottar K; Lied, Einar; Rostrup, Espen; Gudbrandsen, Oddrun A

    2013-02-28

    The popularity of high-protein diets for weight reduction is immense. However, the potential benefits from altering the source of dietary protein rather than the amount is scarcely investigated. In the present study, we examined the effects of fish protein supplement on glucose and lipid metabolism in overweight adults. A total of thirty-four overweight adults were randomised to 8 weeks' supplementation with fish protein or placebo tablets (controls). The intake of fish protein supplement was 3 g/d for the first 4 weeks and 6 g/d for the last 4 weeks. In this study, 8 weeks of fish protein supplementation resulted in lower values of fasting glucose (P< 0·05), 2 h postprandial glucose (P< 0·05) and glucose-area under the curve (AUC) (five measurements over 2 h, P< 0·05) after fish protein supplementation compared to controls. Glucose-AUC was decreased after 8 weeks with fish protein supplement compared to baseline (P< 0·05), concomitant with increased 30 min and decreased 90 min and 2 h insulin C-peptide level (P< 0·05), and reduced LDL-cholesterol (P< 0·05). Body muscle % was increased (P< 0·05) and body fat % was reduced (P< 0·05) after 4 weeks' supplementation. Physical activity and energy and macronutrients intake did not change during the course of the study. In conclusion, short-term daily supplementation with a low dose of fish protein may have beneficial effects on blood levels of glucose and LDL-cholesterol as well as glucose tolerance and body composition in overweight adults. The long-term effects of fish protein supplementation is of interest in the context of using more fish as a protein source in the diet, and the effects of inclusion of fish in the diet of individuals with low glucose tolerance should be evaluated.

  5. Glucose recovery from aqueous solutions by adsorption in metal-organic framework MIL-101: a molecular simulation study

    NASA Astrophysics Data System (ADS)

    Gupta, Krishna M.; Zhang, Kang; Jiang, Jianwen

    2015-08-01

    A molecular simulation study is reported on glucose recovery from aqueous solutions by adsorption in metal-organic framework MIL-101. The F atom of MIL-101 is identified to be the most favorable adsorption site. Among three MIL-101-X (X = H, NH2 or CH3), the parent MIL-101 exhibits the highest adsorption capacity and recovery efficacy. Upon functionalization by -NH2 or -CH3 group, the steric hindrance in MIL-101 increases; consequently, the interactions between glucose and framework become less attractive, thus reducing the capacity and mobility of glucose. The presence of ionic liquid, 1-ethyl-3-methyl-imidazolium acetate, as an impurity reduces the strength of hydrogen-bonding between glucose and MIL-101, and leads to lower capacity and mobility. Upon adding anti-solvent (ethanol or acetone), a similar adverse effect is observed. The simulation study provides useful structural and dynamic properties of glucose in MIL-101, and it suggests that MIL-101 might be a potential candidate for glucose recovery.

  6. Glucose recovery from aqueous solutions by adsorption in metal-organic framework MIL-101: a molecular simulation study.

    PubMed

    Gupta, Krishna M; Zhang, Kang; Jiang, Jianwen

    2015-08-05

    A molecular simulation study is reported on glucose recovery from aqueous solutions by adsorption in metal-organic framework MIL-101. The F atom of MIL-101 is identified to be the most favorable adsorption site. Among three MIL-101-X (X = H, NH2 or CH3), the parent MIL-101 exhibits the highest adsorption capacity and recovery efficacy. Upon functionalization by -NH2 or -CH3 group, the steric hindrance in MIL-101 increases; consequently, the interactions between glucose and framework become less attractive, thus reducing the capacity and mobility of glucose. The presence of ionic liquid, 1-ethyl-3-methyl-imidazolium acetate, as an impurity reduces the strength of hydrogen-bonding between glucose and MIL-101, and leads to lower capacity and mobility. Upon adding anti-solvent (ethanol or acetone), a similar adverse effect is observed. The simulation study provides useful structural and dynamic properties of glucose in MIL-101, and it suggests that MIL-101 might be a potential candidate for glucose recovery.

  7. Boson peak dynamics of glassy glucose studied by integrated terahertz-band spectroscopy

    NASA Astrophysics Data System (ADS)

    Kabeya, Mikitoshi; Mori, Tatsuya; Fujii, Yasuhiro; Koreeda, Akitoshi; Lee, Byoung Wan; Ko, Jae-Hyeon; Kojima, Seiji

    2016-12-01

    We performed terahertz time-domain spectroscopy, low-frequency Raman scattering, and Brillouin light scattering on vitreous glucose to investigate the boson peak (BP) dynamics. In the spectra of α (ν ) /ν2 [ α (ν ) is the absorption coefficient], the BP is clearly observed around 1.1 THz. Correspondingly, the complex dielectric constant spectra show a universal resonancelike behavior only below the BP frequency. As an analytical scheme, we propose the relative light-vibration coupling coefficient (RCC), which is obtainable from the combination of the far-infrared and Raman spectra. The RCC reveals that the infrared light-vibration coupling coefficient CIR(ν ) of the vitreous glucose behaves linearly on frequency which deviates from Taraskin's model of CIR(ν ) =A +B ν2 [S. N. Taraskin et al., Phys. Rev. Lett. 97, 055504 (2006), 10.1103/PhysRevLett.97.055504]. The linearity of CIR(ν ) might require modification of the second term of the model. The measured transverse sound velocity shows an apparent discontinuity with the flattened mode observed in the inelastic neutron scattering study [N. Violini et al., Phys. Rev. B 85, 134204 (2012), 10.1103/PhysRevB.85.134204] and suggests a coupling between the transverse acoustic and flattened modes.

  8. In vitro study of the antioxidative properties of the glucose derivatives against oxidation of plasma components.

    PubMed

    Kolodziejczyk, Joanna; Saluk-Juszczak, Joanna; Wachowicz, Barbara

    2011-06-01

    Oxidative stress has been implicated in the pathogenesis of variety of diseases. Since the endogenous antioxidant defense may be not adequate to counteract the enhanced generation of oxidants, a growing interest in research for exogenous nutrients has been observed. The present study was designed to assess in vitro the antioxidative properties of the glucose derivatives: calcium D-glucarate, D-gluconic acid lactone, and sodium D-gluconate (0.5-3 mM) in the protection of plasma proteins and lipids, against the damage caused by 0.1 mM peroxynitrite (ONOO⁻). Exposure of plasma to ONOO⁻ resulted in carbonyl groups increase, 3-nitrotyrosine (3-NT) formation, reduction in thiol groups, and enhanced lipid peroxidation. D-gluconic acid lactone and sodium D-gluconate effectively decreased 3-NT formation; the antinitrative action of calcium D-glucarate was less effective. In plasma samples incubated with ONOO⁻ and tested compounds, the level of carbonyl groups was decreased in comparison to plasma samples treated only with ONOO⁻. The level of protein -SH groups and glutathione was significantly higher in the presence of glucose derivatives than in plasma samples treated with ONOO⁻ only. All the tested compounds had the inhibitory effect on the peroxynitrite-induced plasma lipids peroxidation. The results obtained from our work indicate that calcium D-glucarate, D-gluconic acid lactone, and sodium D-gluconate may partly protect plasma proteins and lipids against peroxynitrite-induced damages.

  9. Physicochemical studies of glucose, gellan gum, and hydroxypropyl cellulose--inhibition of cast iron corrosion.

    PubMed

    Rajeswari, Velayutham; Kesavan, Devarayan; Gopiraman, Mayakrishnan; Viswanathamurthi, Periasamy

    2013-06-05

    Glucose, gellan gum, and hydroxypropyl cellulose were studied against the acid corrosion of cast iron by means of weight loss, potentiodynamic polarization, and AC impedance spectroscopy techniques. The inhibition efficiency was found to increase with increasing concentration of the inhibitors. The effect of immersion time and temperature were also studied. The addition of potassium iodide to the corrosion-inhibition system showed both antagonism and synergism toward inhibition efficiency. Polarization studies revealed the mixed-type inhibiting nature of the carbohydrates. The adsorption of inhibitors on the cast iron surface obeys Langmuir adsorption isotherm model, both in presence and absence of KI. Physical interaction between the inhibitor molecules and the iron surface was suggested by the thermochemical parameters, rather than chemical interaction.

  10. Glucose Metabolism Effects of Vitamin D in Prediabetes: The VitDmet Randomized Placebo-Controlled Supplementation Study.

    PubMed

    Tuomainen, Tomi-Pekka; Virtanen, Jyrki K; Voutilainen, Sari; Nurmi, Tarja; Mursu, Jaakko; de Mello, Vanessa D F; Schwab, Ursula; Hakumäki, Martti; Pulkki, Kari; Uusitupa, Matti

    2015-01-01

    Epidemiological evidence suggests a role for vitamin D in type 2 diabetes prevention. We investigated the effects of vitamin D3 supplementation on glucose metabolism and inflammation in subjects with prediabetes. A 5-month randomized, double-blind, placebo-controlled intervention with three arms (placebo, 40 μg/d, or 80 μg/d vitamin D3) was carried out among sixty-eight overweight (BMI 25-35) and aging (≥60 years) subjects from Finland, with serum 25-hydroxyvitamin D3 [25(OH)D3] < 75 nmol/L and either impaired fasting glucose or impaired glucose tolerance. Analyses included 66 subjects who completed the trial. Glucose metabolism was evaluated by fasting and 2-hour oral glucose tolerance test-derived indices and glycated hemoglobin. Inflammation was evaluated by high-sensitive C-reactive protein and five cytokines. Although a dose-dependent increase in serum 25(OH)D3 over the supplementation period was observed (P trend < 0.001), there were no other statistically significant differences in changes in the 13 glucose homeostasis indicators between the study groups other than increase in the 120 min glucose concentration (P trend = 0.021) and a decreasing trend both in 30 min plasma insulin (P trend = 0.030) and glycated hemoglobin (P trend = 0.024) concentrations. A borderline statistically significant decreasing trend in interleukin-1 receptor antagonist concentration was observed (P = 0.070). Vitamin D3 supplementation does not improve glucose metabolism in ageing subjects with prediabetes but may have modest anti-inflammatory effects.

  11. Catabolism of Glucose and Lactose in Bifidobacterium animalis subsp. lactis, Studied by 13C Nuclear Magnetic Resonance

    PubMed Central

    González-Rodríguez, Irene; Gaspar, Paula; Sánchez, Borja; Gueimonde, Miguel; Neves, Ana Rute

    2013-01-01

    Bifidobacteria are widely used as probiotics in several commercial products; however, to date there is little knowledge about their carbohydrate metabolic pathways. In this work, we studied the metabolism of glucose and lactose in the widely used probiotic strain Bifidobacterium animalis subsp. lactis BB-12 by in vivo 13C nuclear magnetic resonance (NMR) spectroscopy. The metabolism of [1-13C]glucose was characterized in cells grown in glucose as the sole carbon source. Moreover, the metabolism of lactose specifically labeled with 13C on carbon 1 of the glucose or the galactose moiety was determined in suspensions of cells grown in lactose. These experiments allowed the quantification of some intermediate and end products of the metabolic pathways, as well as determination of the consumption rate of carbon sources. Additionally, the labeling patterns in metabolites derived from the metabolism of glucose specifically labeled with 13C on carbon 1, 2, or 3 in cells grown in glucose or lactose specifically labeled in carbon 1 of the glucose moiety ([1-13Cglucose]lactose), lactose specifically labeled in carbon 1 of the galactose moiety ([1-13Cgalactose]lactose), and [1-13C]glucose in lactose-grown cells were determined in cell extracts by 13C NMR. The NMR analysis showed that the recovery of carbon was fully compatible with the fructose 6-phosphate, or bifid, shunt. The activity of lactate dehydrogenase, acetate kinase, fructose 6-phosphate phosphoketolase, and pyruvate formate lyase differed significantly between glucose and lactose cultures. The transcriptional analysis of several putative glucose and lactose transporters showed a significant induction of Balat_0475 in the presence of lactose, suggesting a role for this protein as a lactose permease. This report provides the first in vivo experimental evidence of the metabolic flux distribution in the catabolic pathway of glucose and lactose in bifidobacteria and shows that the bifid shunt is the only pathway

  12. Characterization of the intravenous glucose tolerance test and the combined glucose-insulin test in donkeys.

    PubMed

    Mendoza, F J; Aguilera-Aguilera, R; Gonzalez-De Cara, C A; Toribio, R E; Estepa, J C; Perez-Ecija, A

    2015-12-01

    Glucose-insulin dynamic challenges such as the intravenous glucose tolerance test (IVGTT) and combined glucose-insulin test (CGIT) have not been described in donkeys. The objectives of this study were (1) to characterize the IVGTT and CGIT in healthy adult donkeys, and (2) to establish normal glucose-insulin proxies. Sixteen donkeys were used and body morphometric variables obtained each. For the IVGTT, glucose (300 mg/kg) was given IV. For the CGIT, glucose (150 mg/kg) followed by recombinant insulin (0.1 IU/kg) were administered IV. Blood samples for glucose and insulin determinations were collected over 300 min. In the IVGTT the positive phase lasted 160.9 ± 13.3 min, glucose concentration peaked at 323.1 ± 9.2 mg/dL and declined at a rate of 1.28 ± 0.15 mg/dL/min. The glucose area under the curve (AUC) was 21.4 ± 1.9 × 10(3) mg/dL/min and the insulin AUC was 7.2 ± 0.9 × 10(3) µIU/mL/min. The positive phase of the CGIT curve lasted 44 ± 3 min, with a glucose clearance rate of 2.01 ± 0.18 mg/dL/min. The negative phase lasted 255.9 ± 3 min, decreasing glucose concentration at rate of -0.63 ± 0.06 mg/dL/min, and reaching a nadir (33.1 ± 3.6 mg/dL) at 118.3 ± 6.3 min. The glucose and insulin AUC values were 15.2 ± 0.9 × 10(3) mg/dL/min and 13.2 ± 0.9 × 10(3) µIU/mL/min. This is the first study characterizing CGIT and IVGTT, and glucose-insulin proxies in healthy adult donkeys. Distinct glucose dynamics, when compared with horses, support the use of species-specific protocols to assess endocrine function.

  13. Glucose utilization by intracranial meningiomas as an index of tumor aggressivity and probability of recurrence: a PET study

    SciTech Connect

    Di Chiro, G.; Hatazawa, J.; Katz, D.A.; Rizzoli, H.V.; De Michele, D.J.

    1987-08-01

    Seventeen patients with intracranial meningiomas were studied with positron emission tomography and fluorine-18-2-fluorodeoxyglucose (PET-FDG) to assess the glucose utilization of these tumors. Four meningiomas followed for 3-5 years after PET-FDG and surgery showed no evidence of recurrence. These tumors had significantly lower glucose utilization rates (1.9 mg/dl/min +/- 1.0) than 11 recurrent or regrowing meningiomas (4.5 mg/dl/min +/- 1.96). The glucose metabolic rates of meningiomas correlated with tumor growth, as estimated from changes in tumor size on repeated computed tomographic scans. Histopathologically, a syncytial (atypical) meningioma had the highest glucose utilization rate, followed by a papillary meningioma and an angioblastic meningioma. Individual transitional and syncytial (typical) meningiomas showed marked differences in glucose metabolism despite similar microscopic appearance. Glucose utilization rate appears to be at least as reliable as histologic classification and other proposed criteria for predicting the behavior and recurrence of intracranial meningiomas.

  14. The impact of continuous glucose monitoring on low interstitial glucose values and low blood glucose values assessed by point-of-care blood glucose meters: results of a crossover trial.

    PubMed

    Hermanns, Norbert; Schumann, Beatrix; Kulzer, Bernhard; Haak, Thomas

    2014-05-01

    In a randomized crossover trial the impact of continuous glucose monitoring (CGM) was tested on the occurrence of low blood glucose values measured by point of care (POC) measurement and on low glucose values measured by CGM in the interstitial fluid. A total of 41 type 1 diabetic patients (age 42.0 ± 11.4 years, diabetes duration 15.3 ± 10.1 years, A1c 8.2 ± 1.4%) used a CGM system (Dexcom SEVEN PLUS system) twice. In first study phase (CGM blind), patients were blind regarding the CGM current glucose levels and were not alerted when critical glucose values were reached. In the second phase (CGM real time), patients had access to current glucose levels and were alerted if critical glucose values were reached. During CGM real time the proportion of hypoglycemic POC blood glucose values were significantly reduced (7.5 ± 5.6% vs 10.1 ± 7.5%; P = .04), whereas the proportion of euglycemic blood glucose values were significantly enhanced (73.7 ± 18.3% vs 68.3 ± 12.1%; P = .01). The duration of low glucose periods in the interstitial fluid was significantly lower in the CGM real time phase (125 ± 89 vs 181 ± 125 minutes per day; P = .005). The time until a low blood glucose was detected by POC measurement was shortened by 33.2 ± 76.1 minutes (P = .03). The study demonstrated that CGM is able to not only reduce duration of hypoglycemia measured by CGM in interstitial fluid, but also reduce the proportion of low POC blood glucose measurements. In addition, hypoglycemia can be detected earlier.

  15. Identification and preliminary SAR studies of (+)-Geodin as a glucose uptake stimulator for rat adipocytes.

    PubMed

    Sato, Seiichi; Okusa, Noriyuki; Ogawa, Akiyo; Ikenoue, Takao; Seki, Tetsuya; Tsuji, Takashi

    2005-09-01

    (+)-Geodin (1) was isolated from Penicillium glabrum AJ117540 with activity that stimulates glucose uptake by rat adipocytes. Unlike insulin it is active in the presence of wortmannin. Dihydrogeodin (2) and sulochrin (3) which are the precursors of (+)-geodin biosynthesis were also isolated from the same fungus. Preliminary SAR studies of 1 showed some analogues had enhanced activity. Especially, the activities of racemic geodin and dibromo analogue (7a) were comparable to that of the natural product. Geodin (1), a known fungal metabolite, was isolated from Penicillium glabrum AJ117540 as an active substance (Fig. 1). Dihydrogeodin (2) and sulochrin (3), the precursors of 1, were also isolated from the same fungal extract. In this study, preliminary mechanistic insight and SAR are reported.

  16. Ethnic Differences in Glucose Homeostasis Markers between the Kyushu-Okinawa Population Study and the Framingham Offspring Study

    PubMed Central

    Ikezaki, Hiroaki; Ai, Masumi; Schaefer, Ernst J.; Otokozawa, Seiko; Asztalos, Bela F.; Nakajima, Katsuyuki; Zhou, Yanhua; Liu, Ching-Ti; Jacques, Paul F.; Cupples, L. Adrienne; Furusyo, Norihiro

    2016-01-01

    We compared markers of glucose homeostasis and their association with diabetes and impaired fasting glucose (IFG) in Fukuoka, Japanese subjects (n = 1108) and age-, gender- and menopausal status-matched participants in the Framingham Offspring Study (n = 1096). The markers examined included fasting glucose, insulin, adiponectin, and glycated albumin, as well as body mass index (BMI), use of medications, and history of diabetes. The results showed that IFG prevalence in Japanese men (15.9%) and women (7.4%) were 50% less than those observed in Framingham men (34.5%) and women (21.4%) (P < 0.001). However, the diabetes prevalence in Japanese men at 13.3% was twice as high (P < 0.01) as the rate in Framingham men at 6.5%, while these rates were similar in women. Median insulin levels in Japanese men (4.6 μIU/mL) and women (4.3 μIU/mL) were about 50% lower (P < 0.001) than those in Framingham men (10.8 μIU/mL) and women (9.9 μIU/mL), as were insulin resistance values (P < 0.001). These population differences were also observed after subjects were stratified by glucose levels. In conclusion, our data indicate that there is significantly less IFG, lower insulin levels, and insulin resistance, but higher diabetes prevalence in Fukuoka men than in Framingham men, indicating that insulin deficiency may be an important cause of diabetes in Japan. PMID:27830830

  17. Direct costs in impaired glucose regulation: results from the population-based Heinz Nixdorf Recall study

    PubMed Central

    Bächle, C; Claessen, H; Andrich, S; Brüne, M; Dintsios, C M; Slomiany, U; Roggenbuck, U; Jöckel, K H; Moebus, S; Icks, A

    2016-01-01

    Objective For the first time, this population-based study sought to analyze healthcare utilization and associated costs in people with normal fasting glycemia (NFG), impaired fasting glycemia (IFG), as well as previously undetected diabetes and previously diagnosed diabetes linking data from the prospective German Heinz Nixdorf Recall (HNR) study with individual claims data from German statutory health insurances. Research design and methods A total of 1709 participants of the HNR 5-year follow-up (mean age (SD) 64.9 (7.5) years, 44.5% men) were included in the study. Age-standardized and sex-standardized healthcare utilization and associated costs (reported as € for the year 2008, perspective of the statutory health insurance) were stratified by diabetes stage defined by the participants' self-report and fasting plasma glucose values. Cost ratios (CRs) were estimated using two-part regression models, adjusting for age, sex, sociodemographic variables and comorbidity. Results The mean total direct healthcare costs for previously diagnosed diabetes, previously undetected diabetes, IFG, and NFG were €2761 (95% CI 2378 to 3268), €2210 (1483 to 4279), €2035 (1732 to 2486) and €1810 (1634 to 2035), respectively. Corresponding age-adjusted and sex-adjusted CRs were 1.53 (1.30 to 1.80), 1.16 (0.91 to 1.47), and 1.09 (0.95 to 1.25) (reference: NFG). Inpatient, outpatient and medication costs varied in order between people with IFG and those with previously undetected diabetes. Conclusions The study provides claims-based detailed cost data in well-defined glucose metabolism subgroups. CRs of individuals with IFG and previously undetected diabetes were surprisingly low. Data are important for the model-based evaluation of screening programs and interventions that are aimed either to prevent diabetes onset or to improve diabetes therapy as well. PMID:27252871

  18. Phased array-fed antenna configuration study

    NASA Technical Reports Server (NTRS)

    Crosswell, W. F.; Ball, D. E.; Taylor, R. C.

    1983-01-01

    The scope of this contract entails a configuration study for a phased array fed transmit antenna operating in the frequency band of 17.7 to 20.2 GHz. This initial contract provides a basis for understanding the design limitations and advantages of advanced phased array and cluster feeds (both utilizing intergral MMIC modules) illuminating folded reflector optics (both near field and focused types). Design parametric analyses are performed utilizing as constraints the objective secondary performance requirements of the Advanced Communications Technology Satellite (Table 1.0). The output of the study provides design information which serves as a data base for future active phased array fed antenna studies such as detailed designs required to support the development of a ground tested breadboard. In general, this study is significant because it provides the antenna community with an understanding of the basic principles which govern near field phased scanned feed effects on secondary reflector system performance. Although several articles have been written on analysis procedures and results for these systems, the authors of this report have observed phenomenon of near field antenna systems not previously documented. Because the physical justification for the exhibited performance is provided herein, the findings of this study add a new dimension to the available knowledge of the subject matter.

  19. Retrospective study on the effect of tight glucose control in postoperative sepsis patients using an artificial pancreas.

    PubMed

    Takahashi, Gaku; Matsumoto, Naoya; Shozushima, Tatsuyori; Onodera, Chiaki; Kan, Shigenori; Akitomi, Shinji; Hoshikawa, Koichi; Kikkawa, Tomohiro; Kojika, Masahiro; Inoue, Yoshihiro; Suzuki, Kenji; Wakabayashi, Go; Endo, Shigeatsu

    2011-12-01

    Tight glucose control (TGC) using a sliding scale based on intermittent blood glucose measurements occasionally can have a fatal outcome as a result of insulin-induced hypoglycemia. The present study was undertaken to examine whether the use of an artificial pancreas to achieve TGC would be possible in postoperative patients with sepsis. The retrospective study was carried out as an exploratory study, focusing on the possibility of precise evaluation of the significance of TGC as a beneficial intervention by serological monitoring of various mediators. TGC was accomplished using an artificial pancreas (STG-22; (Nikkiso, Tokyo, Japan). The patients were divided into two groups: the TGC group (6 patients with sepsis in whom the target blood glucose level set at <150 mg/dl was attempted using the artificial pancreas), and the glucose control (GC) group (6 patients with sepsis in whom glucose control was attempted using a sliding scale; target blood glucose level was set at 200 mg/dl or lower). The mean blood glucose level was 129.7 ± 9.7 mg/dl in the TGC group and 200.9 ± 14.7 mg/dl in the GC group (P < 0.01, ANOVA). No hypoglycemia associated with the artificial pancreas was seen in any of the patients. The serum levels of S100A12 and HMGB-1 tended to decrease, and those of sRAGE tended to increase, in the TGC group. Further data collection from a larger number of cases would be expected to allow a precise assessment of TGC as a potentially beneficial intervention in sepsis patients.

  20. Impact of Randomized Antiretroviral Therapy Initiation on Glucose Metabolism: AIDS Clinical Trials Group Study A5224s

    PubMed Central

    ERLANDSON, Kristine Mace; KITCH, Douglas; TIERNEY, Camlin; SAX, Paul E.; DAAR, Eric S.; MELBOURNE, Kathleen M.; HA, Belinda; MCCOMSEY, Grace A.

    2014-01-01

    Objective Prior studies have found that early HIV protease inhibitors (PIs) contribute to glucose dysregulation. Few randomized trials have evaluated glucose indices in antiretroviral-naïve subjects on newer antiretroviral therapy (ART). Methods A5224s was a substudy of A5202, a prospective trial of 1857 ART-naïve participants randomized to blinded abacavir-lamivudine (ABC/3TC) or tenofovir DF-emtricitabine (TDF/FTC) with open-label efavirenz (EFV) or atazanavir-ritonavir (ATV/r). Analyses used 2-sample t-tests, Spearman correlation coefficients and linear regression. Results A5224s included 269 non-diabetic subjects: 85% male, 47% white non-Hispanic, baseline median age 38 years, HIV-1 RNA 4.6 log10 copies/mL and CD4 233 cells/μL. Overall, significant 96-week increases occurred in fasting glucose, insulin, and the homeostatic model assessment of insulin resistance (HOMA-IR), p≤0.004. Assignment to EFV (vs ATV/r) resulted in significantly greater glucose increase (mean difference 4.4; 95% CI 1.3, 7.5 mg/dL; p=0.006) but not insulin or HOMA-IR (p≥0.72). Glucose indices were not significantly different between ABC/3TC or TDF/FTC arms, p≥0.18. Significant correlations were detected between changes in glucose indices and changes in body mass index; all r≥0.23, p≤0.001. In multivariable analyses, in addition to the EFV effect, higher baseline HIV-1 RNA, and greater BMI change were significant independent factors associated with greater glucose increase. Conclusions Changes in glucose metabolism were not significantly different between TDF/FTC- and ABC/3TC-based regimens. A small but significantly greater increase in glucose was observed in those assigned to EFV. As glucose dysregulation may increase with time on ART, longer term studies will be needed to further clarify the clinical significance of these findings. PMID:24637543

  1. Transparent Analogs for Alloy Phase Studies

    NASA Technical Reports Server (NTRS)

    Frazier, D. O.; Smith, James E., Jr.

    1987-01-01

    Report describes experiments to add information to data base supporting use of transparent, partially miscible liquids and solids as analogs in studies of alloy solidification. Behavior of these materials observed directly while they undergo liquid/liquid and liquid/solid phase transformations. Light-scattering techniques used to determine phase boundaries. Transparent analogs allow observation of both solidification patterns and processes leading to those patterns, whereas metal alloys require tedious post-solidification metallographic analyses because processes not generally observed. Experiments with transparent substances safer and cheaper since conducted at much lower temperatures.

  2. Regional brain glucose metabolism in chronic schizophrenia. A positron emission transaxial tomographic study

    SciTech Connect

    Farkas, T.; Wolf, A.P.; Jaeger, J.; Brodie, J.D.; Christman, D.R.; Fowler, J.S.

    1984-03-01

    Thirteen diagnosed schizophrenics and 11 normal controls were studied with a method using the PETT III positron emission tomograph (PET) and fluorodeoxyglucose labeled with fluorine 18. Each subject also had a computed tomographic (CT) scan. For each subject, two brain levels, one through the basal ganglia and one through the semioval center, were analyzed for the mean regional metabolic glucose rate. Specifically, relationships between frontal and posterior regions were evaluated. The CT scans of matching levels were superimposed on the functional PET images to provide anatomic criteria for region of interest selection. While no whole-slice metabolic differences were apparent between groups, schizophrenics had significantly lower activity in the frontal lobes, relative to posterior regions. The medicated and drug-free groups did not differ from one another in these regards. Trait v state dependency of the phenomenon was analyzed, and several technological limitations were considered.

  3. Study on iron oxide nanoparticles coated with glucose-derived polymers for biomedical applications

    NASA Astrophysics Data System (ADS)

    Herea, D. D.; Chiriac, H.; Lupu, N.; Grigoras, M.; Stoian, G.; Stoica, B. A.; Petreus, T.

    2015-10-01

    This study reports an approach for a facile one-step synthesis of magnetic nanoparticles (MNPs) coated with glucose-derived polymers (GDP) through a mechanochemical hydrothermal process for biomedical applications. Polymer-coated magnetic nanoparticles (Fe2O3/Fe3O4), with sizes below 10 nm, exhibited superparamagnetic behavior, with a specific magnetization saturation value of about 40 emu/g, and a maximum specific absorption rate (SAR) of 30 W/g in AC magnetic fields. Depending on the intensity of the applied AC magnetic field, a temperature of 42 °C can be achieved in 4-17 min. The surface polymerized layer affords functional hydroxyl groups for binding to biomolecules containing carboxyl, thiol, or amino groups, thereby making the coated nanoparticles feasible for bio-conjugation. In vitro cytotoxicity evaluation pointed out that a relatively high concentration of polymer-coated magnetic nanoparticles (GDP-MNPs) did not induce severe cell alteration, suggesting a good biocompatibility.

  4. Positron computed tomography studies of cerebral glucose metabolism in man: theory and application in nuclear medicine.

    PubMed

    Phelps, M E

    1981-01-01

    The capability of positron computed tomography (PCT) to delineate the substructures of the brain and its facility for accurately measuring the local tissue radioactivity concentration allow the application of tracer kinetic models for the study of local cerebral function in man. This principle and an adaptation of the 14C-deoxyglucose (DG) model of Sokoloff et al. with 18F-2-fluoro-deoxy-D-glucose (FDG) is being used at UCLA. Brookhaven National Laboratory, University of Pennsylvania, NIH, and the Massachusetts General Hospital to determine the local cerebral glucose metabolic rate (LCMRGIc) in normal man at rest and during sensory activation and the changes that occur in patients with a variety of cerebral disorders. Kinetic studies with PCT have been employed to measure the rate constants of the model in different gray and white matter structures of the brain in both normal and ischemic states. The precision of the method in normals has been shown to be about +/- 5% for 1.5-2.0 sq cm regions of the brain. Studies in normals have yielded values for hemispheric CMRGIc that are in agreement with measurement using the Kety-Schmidt technique and LCMRGIc values in agreement with values in monkeys using DG autoradiography. Studies in volunteers subjected to visual and auditory stimulation are demonstrating the potential of this technique for investigating the human brain's response to different stimuli. STudies in patients with stroke show excellent correlation between the degree, extent, and particular structures involved and the clinical symptoms. The method consistently detected hypometabolism in cortical, thalamic, and striatal tissues that were dysfunctional due to deactivation or damage but which appeared normal on x-ray CT. Studies in patients with partial epilepsy have shown hypometabolic zones that highly correlated anatomically with interictal EEG spike foci and were associated with normal x-ray CT studies in 77% of the patients studied. The studies on

  5. An Improved Method for Studying the Enzyme-Catalyzed Oxidation of Glucose Using Luminescent Probes

    ERIC Educational Resources Information Center

    Bare, William D.; Pham, Chi V.; Cuber, Matthew; Demas, J. N.

    2007-01-01

    A new method is presented for measuring the rate of the oxidation of glucose in the presence of glucose oxidase. The improved method employs luminescence measurements to directly determine the concentration of oxygen in real time, thus obviating complicated reaction schemes employed in previous methods. Our method has been used to determine…

  6. The Relationship between Physical Activity and Plasma Glucose Level amongst Ellisras Rural Young Adult Males and Females: Ellisras Longitudinal Study

    PubMed Central

    Matshipi, Moloko; Monyeki, Kotsedi Daniel; Kemper, Han

    2017-01-01

    Unhealthy lifestyle characteristics such as low physical activity (PA) and high plasma glucose levels (PGLs) may lead to the development of type 2 diabetes mellitus in adulthood. The aim of this study was to investigate (i) the level of physical activity; (ii) the prevalence of pre-diabetes and (iii) the relationship between PA and plasma glucose level in a rural Ellisras adult population aged 18 to 28 years. A total of 713 young adults (349 males and 364 females) who took part in the Ellisras Longitudinal Study participated in the study. Fasting plasma glucose levels were analysed using Accutrend glucose meters. Physical activity data was collected using a validated questionnaire. Linear regression was used to assess the relationship between PA and pre-diabetes. The prevalence of pre-diabetes was between 45.7% and 50.2% and that of physical inactivity was 67.3% and 71.0% for males and females, respectively. There was no significant (p > 0.05) relationship between PA and pre-diabetes (beta = 1.016; 95% Confidence Interval from 0.352 to 2.777). The health benefits of PA increased with the increasing frequency, duration and intensity of exercise. The prevalence of pre-diabetes was found to be very high in this population. Our results suggest that greater physical activity is associated with low plasma glucose levels. PMID:28212346

  7. The Relationship between Physical Activity and Plasma Glucose Level amongst Ellisras Rural Young Adult Males and Females: Ellisras Longitudinal Study.

    PubMed

    Matshipi, Moloko; Monyeki, Kotsedi Daniel; Kemper, Han

    2017-02-16

    Unhealthy lifestyle characteristics such as low physical activity (PA) and high plasma glucose levels (PGLs) may lead to the development of type 2 diabetes mellitus in adulthood. The aim of this study was to investigate (i) the level of physical activity; (ii) the prevalence of pre-diabetes and (iii) the relationship between PA and plasma glucose level in a rural Ellisras adult population aged 18 to 28 years. A total of 713 young adults (349 males and 364 females) who took part in the Ellisras Longitudinal Study participated in the study. Fasting plasma glucose levels were analysed using Accutrend glucose meters. Physical activity data was collected using a validated questionnaire. Linear regression was used to assess the relationship between PA and pre-diabetes. The prevalence of pre-diabetes was between 45.7% and 50.2% and that of physical inactivity was 67.3% and 71.0% for males and females, respectively. There was no significant (p > 0.05) relationship between PA and pre-diabetes (beta = 1.016; 95% Confidence Interval from 0.352 to 2.777). The health benefits of PA increased with the increasing frequency, duration and intensity of exercise. The prevalence of pre-diabetes was found to be very high in this population. Our results suggest that greater physical activity is associated with low plasma glucose levels.

  8. LST phase A design update study

    NASA Technical Reports Server (NTRS)

    1973-01-01

    An update is presented of the Phase A study of the Large Space Telescope (LST), based on changes in guidelines and new data developed subsequent to the Phase A study. The study defines an LST concept based on the broad mission guidelines provided by the Office of Space Science (OSS), the scientific requirements developed by OSS with the scientific community, and an understanding of long range NASA planning current at the time the study was performed. A low cost design approach was followed. This resulted in the use of standard spacecraft hardware, the provision for maintenance at the black box level, growth potential in systems designs, and sharing of shuttle maintenance flights with other payloads (See N73-18449 through N73-18453)

  9. TDRSS telecommunications study. Phase 1: Final report

    NASA Technical Reports Server (NTRS)

    Cahn, C. R.; Cnossen, R. S.

    1974-01-01

    A parametric analysis of the telecommunications support capability of the Tracking and Data Relay Satellite System (TDRSS) was performed. Emphasis was placed on maximizing support capability provided to the user while minimizing impact on the user spacecraft. This study evaluates the present TDRSS configuration as presented in the TDRSS Definition Phase Study Report, December 1973 to determine potential changes for improving the overall performance. In addition, it provides specifications of the user transponder equipment to be used in the TDRSS.

  10. Effects of glucose limitation on biomass and spiramycin production by Streptomyces ambofaciens.

    PubMed

    Colombié, V; Bideaux, C; Goma, G; Uribelarrea, J L

    2005-11-01

    Spiramycin production by Streptomyces ambofaciens Sp181110 with glucose as the carbon source was studied under a controlled nutritional environment. In a batch culture, the glucose excess after ammonium depletion led to pyruvate and alpha-ketoglutarate accumulation. 85 mg/l of spiramycin were produced in less than 70 h during the stationary and maintenance phase on these acids after glucose exhaustion. Fed-batch strategy was designed to study spiramycin production without by-product formation and glucose accumulation. In these conditions, up to 150 mg/l were produced in less than 80 h during the stationary phase on glucose. The antibiotic titre was found independent of the glucose feeding under carbon limitation and the importance of putative intracellular reserves formed after nutrient exhaustion was suggested. Besides, spiramycin production was not inhibited by the limiting flux of glucose.

  11. Inconsistent blood glucose checking before driving among drivers with type 1 diabetes: Results from the Australian YourSAY: Glucose Monitoring study.

    PubMed

    Trawley, S; Holmes-Truscott, E; Speight, J

    2016-11-01

    In a survey of Australian drivers with type 1 diabetes, three-quarters reported not checking their blood glucose consistently before driving. They reported lack of health professional recommendation of this behaviour, less concern about safety, and preference for consuming fast-acting glucose, which may be less effective for mitigating risk.

  12. A study on phase-noise reduction method in phase-locked loop systems.

    PubMed

    Takagi, Keiji

    2003-09-01

    Experimental studies are carried out on phase noise and the correlation coefficient between the phase and average current noises of voltage-controlled oscillator in phased-locked loop (PLL) systems. The precise phase stabilization technique is discussed, and new methods to reduce the phase noise are described in PLL systems, using the correlation.

  13. Glucose monitoring of patients with diabetes mellitus receiving general anesthesia: a study of the practices of anesthesia providers in a large community hospital.

    PubMed

    Maser, R E; Ellers, J M; DeCherney, G S

    1996-08-01

    Surgical stress causes hyperglycemia with potential complications (e.g., impaired granulocytic function and delayed wound healing) particularly when glucose levels exceed 250 mg/dL. Standards of care for patients with diabetes undergoing surgery may vary by geographic locale, type of surgical procedure, and type of diabetes. We explored whether anesthesia providers monitor glucose levels in patients with diabetes. Records of 100 patients with diabetes who underwent surgery under general anesthesia (length of procedure: range, 1.9-11.8 hours) were reviewed. Demographic information, glucose levels, frequency of glucose monitoring, and treatment used for diabetes management preoperatively, intraoperatively, and postoperatively were recorded. There were 46 males and 54 females, aged 62 +/- 13 years (55% currently treated with insulin). Of the study cohort, 89% had preoperative, 23% had intraoperative, and 54% had postoperative glucose monitoring performed. As expected, postoperative glucose concentrations were significantly higher than preoperative glucose levels (mean difference, 99 mg/dL, P < .01). The mean postoperative glucose level was 262 +/- 89 mg/dL with 30 of the 54 monitored patients having a postoperative glucose level greater than 250 mg/dL. Individuals treated with insulin and those who underwent major surgery were more likely to have glucose levels monitored. These results suggest that better strategies for monitoring glucose levels during the surgical period are needed.

  14. Randomized Pilot Study of Cabergoline, a Dopamine Receptor Agonist: Effects on Body Weight and Glucose Tolerance in Obese Adults

    PubMed Central

    Gibson, Charlisa D.; Karmally, Wahida; McMahon, Donald J.; Wardlaw, Sharon L.; Korner, Judith

    2011-01-01

    Aim Dopaminergic hypofunction and hyperprolactinemia have been implicated in the pathogenesis of obesity and glucose intolerance. The aim of this pilot study was to determine the efficacy of cabergoline, a dopamine receptor agonist, on body weight and glucose tolerance in obese non-diabetic persons with normal plasma prolactin levels. Materials and Methods This 16-week double blind, placebo-controlled pilot study randomized non- diabetic obese adults (BMI 30-42 kg/m2) to placebo or cabergoline (0.25 mg twice weekly for 4 weeks followed by 0.5 mg twice weekly for the next 12 weeks). Of 40 subjects enrolled, 29 completed 16 weeks: 16 randomized to placebo, 13 to cabergoline. All subjects were counseled on a 500 kcal/day calorie deficit diet. A 75 gm oral glucose tolerance test was performed at baseline and at 16 weeks. Results As expected, prolactin levels decreased after cabergoline (P<0.001). Weight loss was similar after placebo compared with cabergoline treatment: 1.0 vs 1.2% body weight, respectively. Fasting glucose levels did not differ between groups after treatment, however, 90 minute post-prandial glucose and insulin decreased in the cabergoline group only (P = 0.029). HOMA-IR increased by 40% after placebo, and 1.5% after cabergoline treatment. Conclusions This pilot study suggests that cabergoline therapy may improve glucose tolerance independent of weight loss, however, a larger, longer term study of dopamine receptor agonist therapy in obese individuals is warranted to confirm this finding. PMID:22074059

  15. Electron-transfer studies with a new flavin adenine dinucleotide dependent glucose dehydrogenase and osmium polymers of different redox potentials.

    PubMed

    Zafar, Muhammad Nadeem; Wang, Xiaoju; Sygmund, Christoph; Ludwig, Roland; Leech, Dónal; Gorton, Lo

    2012-01-03

    A new extracellular flavin adenine dinucleotide (FAD)-dependent glucose dehydrogenase from Glomerella cingulata (GcGDH) was electrochemically studied as a recognition element in glucose biosensors. The redox enzyme was recombinantly produced in Pichia pastoris and homogeneously purified, and its glucose-oxidizing properties on spectrographic graphite electrodes were investigated. Six different Os polymers, the redox potentials of which ranged in a broad potential window between +15 and +489 mV versus the normal hydrogen electrode (NHE), were used to immobilize and "wire" GcGDH to the spectrographic graphite electrode's surface. The GcGDH/Os polymer modified electrodes were evaluated by chronoamperometry using flow injection analysis. The current response was investigated using a stepwisely increased applied potential. It was observed that the ratio of GcGDH/Os polymer and the overall loading of the enzyme electrode significantly affect the performance of the enzyme electrode for glucose oxidation. The best-suited Os polymer [Os(4,4'-dimethyl-2,2'-bipyridine)(2)(PVI)Cl](+) had a potential of +309 mV versus NHE, and the optimum GcGDH/Os polymer ratio was 1:2 yielding a maximum current density of 493 μA·cm(-2) at a 30 mM glucose concentration.

  16. Associations between Dietary Patterns and Impaired Fasting Glucose in Chinese Men: A Cross-Sectional Study

    PubMed Central

    Zhang, Meilin; Zhu, Yufeng; Li, Ping; Chang, Hong; Wang, Xuan; Liu, Weiqiao; Zhang, Yuwen; Huang, Guowei

    2015-01-01

    Few studies have examined the association between Asian dietary pattern and prediabetes, in particular, the Chinese diet. We conducted a cross-sectional study to identify dietary patterns associated with impaired fasting glucose (IFG) which considered a state of prediabetes in Chinese men. The study included 1495 Chinese men aged 20 to 75 years. Information about diet was obtained using an 81-item food frequency questionnaire (FFQ), and 21 predefined food groups were considered in a factor analysis. Three dietary patterns were generated by factor analysis: (1) a vegetables-fruits pattern; (2) an animal offal-dessert pattern; and (3) a white rice-red meat pattern. The multivariate-adjusted odds ratio (OR) of IFG for the highest tertile of the animal offal-dessert pattern in comparison with the lowest tertile was 3.15 (95% confidence intervals (CI): 1.87–5.30). The vegetables-fruits dietary pattern was negatively associated with the risk of IFG, but a significant association was observed only in the third tertile. There was no significant association between IFG and the white rice-red meat pattern. Our findings indicated that the vegetables-fruits dietary pattern was inversely associated with IFG, whereas the animal offal-dessert pattern was associated with an increased risk of IFG in Chinese men. Further prospective studies are needed to elucidate the diet-prediabetes relationships. PMID:26402695

  17. Associations between Dietary Patterns and Impaired Fasting Glucose in Chinese Men: A Cross-Sectional Study.

    PubMed

    Zhang, Meilin; Zhu, Yufeng; Li, Ping; Chang, Hong; Wang, Xuan; Liu, Weiqiao; Zhang, Yuwen; Huang, Guowei

    2015-09-21

    Few studies have examined the association between Asian dietary pattern and prediabetes, in particular, the Chinese diet. We conducted a cross-sectional study to identify dietary patterns associated with impaired fasting glucose (IFG) which considered a state of prediabetes in Chinese men. The study included 1495 Chinese men aged 20 to 75 years. Information about diet was obtained using an 81-item food frequency questionnaire (FFQ), and 21 predefined food groups were considered in a factor analysis. Three dietary patterns were generated by factor analysis: (1) a vegetables-fruits pattern; (2) an animal offal-dessert pattern; and (3) a white rice-red meat pattern. The multivariate-adjusted odds ratio (OR) of IFG for the highest tertile of the animal offal-dessert pattern in comparison with the lowest tertile was 3.15 (95% confidence intervals (CI): 1.87-5.30). The vegetables-fruits dietary pattern was negatively associated with the risk of IFG, but a significant association was observed only in the third tertile. There was no significant association between IFG and the white rice-red meat pattern. Our findings indicated that the vegetables-fruits dietary pattern was inversely associated with IFG, whereas the animal offal-dessert pattern was associated with an increased risk of IFG in Chinese men. Further prospective studies are needed to elucidate the diet-prediabetes relationships.

  18. Salacia Extract Improves Postprandial Glucose and Insulin Response: A Randomized Double-Blind, Placebo Controlled, Crossover Study in Healthy Volunteers

    PubMed Central

    Jeykodi, Shankaranarayanan; Deshpande, Jayant

    2016-01-01

    Thirty-five healthy subjects were randomly assigned to different doses of Salacia chinensis extract (200 mg, 300 mg, and 500 mg SCE) capsules and compared with placebo. It is a placebo controlled randomized crossover design study. Subjects were given oral sucrose solution along with capsules and plasma glucose and insulin responses were analyzed. Blood samples were collected at 0, 30, 60, 90, 120, and 180 minutes after administration. AUC insulin significantly lowered after ingestion of SCE. No significant adverse events were observed. Reducing glucose and insulin is very important in reducing postprandial hyperglycemia. PMID:27803937

  19. A glucose sensor protein for continuous glucose monitoring.

    PubMed

    Veetil, Jithesh V; Jin, Sha; Ye, Kaiming

    2010-12-15

    In vivo continuous glucose monitoring has posed a significant challenge to glucose sensor development due to the lack of reliable techniques that are non- or at least minimally-invasive. In this proof-of-concept study, we demonstrated the development of a new glucose sensor protein, AcGFP1-GBPcys-mCherry, and an optical sensor assembly, capable of generating quantifiable FRET (fluorescence resonance energy transfer) signals for glucose monitoring. Our experimental data showed that the engineered glucose sensor protein can generate measurable FRET signals in response to glucose concentrations varying from 25 to 800 μM. The sensor developed based on this protein had a shelf-life of up to 3 weeks. The sensor response was devoid of interference from compounds like galactose, fructose, lactose, mannose, and mannitol when tested at physiologically significant concentrations of these compounds. This new glucose sensor protein can potentially be used to develop implantable glucose sensors for continuous glucose monitoring.

  20. Antihypertensive drug class and impaired fasting glucose: a risk association study among Chinese patients with uncomplicated hypertension

    PubMed Central

    Wong, Martin CS; Jiang, Johnny Y; Fung, H; Griffiths, Sian; Mercer, Stewart

    2008-01-01

    Background There is a scarcity of studies addressing the factors associated with impaired fasting glucose in Chinese patients with uncomplicated hypertension. We included 1,218 patients newly prescribed a single antihypertensive drug in the public primary healthcare setting in Hong Kong, where their fasting glucose levels were measured 6–7 weeks after the first-ever antihypertensive prescription. Methods The odds ratios of having above borderline (≥ 6.1 mmol/l) and adverse (≥ 7.0 mmol/l) glucose levels, respectively, were studied according to patient age, gender, socioeconomic status, clinic types and antihypertensive drug classes by multivariable regression analyses. Results The fasting glucose levels were statistically similar (p = 0.786) among patients prescribed thiazide diuretics (5.48 mmol/l, 95%, 5.38, 5.59), calcium channel blockers (5.46 mmol/l, 95% C.I. 5.37, 5.54), β-blockers (5.42 mmol/l, 95% C.I. 5.34, 5.51) and drugs acting on the renin angiotensin system (RAS) [5.41 mmol/l, 95% C.I. 5.20, 5.61]. Multivariate analyses reported no significant associations between antihypertensive drug class and impaired fasting glucose. Elderly patients and male gender were significantly more likely to present with above borderline and adverse readings respectively. Conclusion Clinicians should be aware of the increased risk of impaired fasting glucose in these groups, and use of thiazides should not in itself deter its use as a first-line antihypertensive agent among ethnic Chinese patients. PMID:18783618

  1. Glucose Homeostasis and Weight Loss in Morbidly Obese Patients Undergoing Banded Sleeve Gastrectomy: A Prospective Clinical Study

    PubMed Central

    Miguel, Gustavo Peixoto Soares; Azevedo, Joao Luiz Moreira Coutinho; Neto, Carlos Gicovate; Moreira, Cora Lavigne Castelo Branco; Viana, Elaine Cristina; Carvalho, Perseu Seixas

    2009-01-01

    OBJECTIVE To assess glucose homeostasis and weight loss in morbidly obese patients undergoing Silastic® ring sleeve gas-trectomy. METHODS This was a prospective clinical study. Thirty-three female patients with a mean body mass index (BMI) of 42.33 ± 1.50 kg/m2 (range: 40–45 kg/m2), a mean age of 36.7 ± 9.4 years and a mean waist circumference of 118.7 ± 5.98 cm were included in this study. Type 2 diabetes mellitus was observed in 11 patients (33.3%), and glucose intolerance was observed in 4 patients (12.1%). Mean plasma fasting glucose levels were 109.77 ± 44.19 mg/dl (75–320) in the preoperative period. All Silastic® ring sleeve gastrectomy procedures were performed by the same surgical team using the same anesthetic technique. The patients were monitored for at least 12 months after surgery. RESULTS The mean weight of the patients decreased from 107.69 ± 6.57 kg to 70.52 ± 9.36 kg (p < 0.001), the mean BMI decreased to 27.4 ± 2.42 kg/m2 (p < 0.001), and the mean waist circumference decreased to 89.87 cm ± 6.66 (p < 0.001) in the postoperative period. Excess BMI loss was 86.5 ± 14.2%. Fasting glucose levels were reduced to 80.94 ± 6.3 mg/dl (p < 0.001). Remission of diabetes and glucose intolerance was observed in all patients. CONCLUSION Silastic® ring sleeve gastrectomy was effective in promoting weight loss, waist circumference reduction and control of glucose homeostasis in morbidly obese patients. PMID:19936183

  2. Main Facilitators of Smoking Among Young Males in Tehran: Tehran Lipid and Glucose Study

    PubMed Central

    Rostami Dovom, Marzieh; Ramezani Tehrani, Fahimeh; Amiri, Parisa; Amirshekari, Golshan; Farahmand, Maryam; Azizi, Fereidoun

    2014-01-01

    Background: Smoking is the most preventable risk factor for non-communicable diseases and its alarming trend. Objectives: The aim of this study was to explore and determine facilitating factors for smoking in young males, who participated in the Tehran Lipid and Glucose Study (TLGS), from their own perspective. Patients and Methods: This qualitative study was conducted within the framework of the TLGS. Participants were young males with 15 to 25 years of age and various levels of education. The inductive content analysis approach was used to analyze data on the participants’ perceptions with regard to smoking facilitators. Data collection was conducted through discussions by six semi-structured focus groups consisted of five to seven people. All the interviews were transcribed after being recorded and analyzed through constant comparative analysis. Results: Two main categories derived from the analysis of the data: I) personal needs and features; and II) environmental facilitators. The former concept included three subcategories: 1) fulfilling essential needs; 2) search for identity; and 3) lack of life skills. Environmental facilitators were also divided into two subcategories: 1) social patterns; and 2) ease of access. Conclusions: Tendency towards smoking is influenced by different factors. Clarifying these influential factors for smoking from the perspective of young males can be important in designing effective preventive programs. PMID:25593726

  3. FETAX interlaboratory validation study: Phase 2 testing

    SciTech Connect

    Bantle, J.A. . Dept. of Zoology); Burton, D.T. ); Dawson, D.A. . Dept. of Biology and Toxicology)

    1994-10-01

    The Frog Embryo Teratogenesis Assay-Xenopus (FETAX) is a 96-h whole embryo developmental toxicity screening assay that can be used in ecotoxicology and in detecting mammalian developmental toxicants when an in vitro metabolic activation system is employed. A standardized American Society for Testing and Materials (ASTM) guide for the conduct of FETAX has been published along with a companion atlas that helps in embryo staging and identifying malformations. As part of the ASTM process, an interlaboratory validation study was undertaken to evaluate the repeatability and reliability of FETAX. Six different laboratories participated in the study. Each laboratory utilized one technician with the exception of one laboratory, which utilized two independent technicians. In Phase 1, FETAX proved to be more repeatable and reliable than many other bioassays. However, some excessive variation was observed in a few laboratories. Some of this variation may have been due to an initial lack of experience with the assay by some technicians. Phase 2, which is reported here, showed far less intralaboratory and interlaboratory variability than did Phase 1. Nonteratogens such as saccharin and sodium cyclamate showed the most consistent results, whereas more variability was observed for the teratogens caffeine and 5-fluorouracil. Interlaboratory coefficient of variation values for all FETAX end points ranged from 7.3 to 54.7%. The minimum concentration to inhibit growth proved to be the most variable end point for three of the four test chemicals, whereas the LC50 and EC50 (malformation) proved to be less variable.

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

    PubMed

    Szkudelski, Tomasz; Szkudelska, Katarzyna

    2017-02-01

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

  5. A Fluorescence Correlation Spectroscopy Study of the Cryoprotective Mechanism of Glucose on Hemocyanin

    NASA Astrophysics Data System (ADS)

    Hauger, Eric J.

    Cryopreservation is the method of preserving biomaterials by cooling and storing them at very low temperatures. In order to prevent the damaging effects of cooling, cryoprotectants are used to inhibit ice formation. Common cryoprotectants used today include ethylene glycol, propylene glycol, dimethyl sulfoxide, glycerol, and sugars. However, the mechanism responsible for the effectiveness of these cryoprotectants is poorly understood on the molecular level. The water replacement model predicts that water molecules around the surfaces of proteins are replaced with sugar molecules, forming a protective layer against the denaturing ice formation. Under this scheme, one would expect an increase in the hydrodynamic radius with increasing sugar concentration. In order to test this hypothesis, two-photon fluorescence correlation spectroscopy (FCS) was used to measure the hydrodynamic radius of hemocyanin (Hc), an oxygen-carrying protein found in arthropods, in glucose solutions up to 20wt%. FCS found that the hydrodynamic radius was invariant with increasing glucose concentration. Dynamic light scattering (DLS) results verified the hydrodynamic radius of hemocyanin in the absence of glucose. Although this invariant trend seems to indicate that the water replacement hypothesis is invalid the expected glucose layer around the Hc is smaller than the error in the hydrodynamic radius measurements for FCS. The expected change in the hydrodynamic radius with an additional layer of glucose is 1nm, however, the FCS standard error is +/-3.61nm. Therefore, the water replacement model cannot be confirmed nor refuted as a possible explanation for the cryoprotective effects of glucose on Hc.

  6. Crew interface definition study, phase 1

    NASA Technical Reports Server (NTRS)

    Callihan, J. C.; Kraemer, J. W.; Alles, J. A.

    1971-01-01

    The timeline analysis of the Shuttle orbiter missions which was conducted in the Phase I Crew Interface Definition Study and the requirements for the man-in-the-loop simulation study are presented. Mission definitions and objectives are presented as they relate to various Shuttle Orbiter missions. The requirements for crew participation and the information required by the crew are discussed, and finally the rationale behind the display concept and calling procedures is given. The simulation objectives, the simulation mechanization, including a detailed presentation of the display and control concept, the simulator test plan and the results are discussed.

  7. Periodontal Bacteria and Prediabetes Prevalence in ORIGINS: The Oral Infections, Glucose Intolerance, and Insulin Resistance Study.

    PubMed

    Demmer, R T; Jacobs, D R; Singh, R; Zuk, A; Rosenbaum, M; Papapanou, P N; Desvarieux, M

    2015-09-01

    Periodontitis and type 2 diabetes mellitus are known to be associated. The relationship between periodontal microbiota and early diabetes risk has not been studied. We investigated the association between periodontal bacteria and prediabetes prevalence among diabetes-free adults. ORIGINS (the Oral Infections, Glucose Intolerance and Insulin Resistance Study) cross sectionally enrolled 300 diabetes-free adults aged 20 to 55 y (mean ± SD, 34 ± 10 y; 77% female). Prediabetes was defined as follows: 1) hemoglobin A1c values ranging from 5.7% to 6.4% or 2) fasting plasma glucose ranging from 100 to 125 mg/dL. In 1,188 subgingival plaque samples, 11 bacterial species were assessed at baseline, including Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola, Tannerella forsythia, and Actinomyces naeslundii. Full-mouth clinical periodontal examinations were performed, and participants were defined as having no/mild periodontitis vs. moderate/severe periodontitis per the definition of the Centers for Disease Control and Prevention / American Academy of Periodontology. Modified Poisson regression evaluated prediabetes prevalence across bacterial tertiles. Prevalence ratios and 95% confidence intervals for third vs. first tertiles are presented. All analyses were adjusted for cardiometabolic risk factors. All results presented currently arise from the baseline cross section. Prediabetes prevalence was 18%, and 58% of participants had moderate/severe periodontitis. Prevalence ratios (95% confidence intervals) summarizing associations between bacterial levels and prediabetes were as follows: A. actinomycetemcomitans, 2.48 (1.34, 4.58), P = 0.004; P. gingivalis, 3.41 (1.78, 6.58), P = 0.0003; T. denticola, 1.99 (0.992, 4.00), P = 0.052; T. forsythia, 1.95 (1.0, 3.84), P = 0.05; A. naeslundii, 0.46 (0.25, 0.85), P = 0.01. The prevalence ratio for prediabetes among participants with moderate/severe vs. no/mild periodontitis was 1.47 (0.78, 2.74), P

  8. Berberine, a plant alkaloid with lipid- and glucose-lowering properties: From in vitro evidence to clinical studies.

    PubMed

    Pirillo, Angela; Catapano, Alberico Luigi

    2015-12-01

    Berberine (BBR) is an isoquinoline plant alkaloid endowed with several pharmacological activities, including anti-microbial, glucose- and cholesterol-lowering, anti-tumoral and immunomodulatory properties. The main mechanism by which BBR exerts a protective role in atherosclerosis relates to its cholesterol-lowering activity. BBR significantly increases hepatic low density lipoprotein receptor (LDLR) expression and reduces the expression and secretion of the LDLR modulator proprotein convertase subtilisin/kexin type 9 (PCSK9). In addition to this, several other atheroprotective effects have been ascribed to BBR, including anti-inflammatory and anti-oxidant properties, inhibition of vascular smooth muscle cell proliferation and improvement of endothelial dysfunction. BBR also increases glucose utilization in adipocytes and myocytes, while decreases glucose absorption in intestinal cells, resulting in a net hypoglycemic effect. In hypercholesterolemic animals, BBR significantly decreases LDL-C and total cholesterol (TC) levels and reduces aortic lesions, an effect similar to that of statins. In diabetic animals, BBR significantly reduces glucose levels, improves glucose tolerance, reduces body weight gain and adipose tissue mass. Several clinical studies have also tested the efficacy of BBR in humans. In hypercholesterolemic subjects, BBR induces a significant reduction of TC, triglycerides and LDL-C levels and a significant increase of HDL-C levels, without major adverse effects. BBR also reduces glycemia and plasma cholesterol in diabetic patients, improves lipid and glucose profile and decreases body mass index and waist circumference in subjects with metabolic syndrome. These findings, together with the good tolerability, suggest that BBR administration might be considered a potential therapeutic approach for the treatment of hypercholesterolemia or diabetes. Given the level of evidence available to date well-designed randomized controlled trials to test safety

  9. Glucose oxidase incorporated collagen matrices for dermal wound repair in diabetic rat models: a biochemical study.

    PubMed

    Arul, V; Masilamoni, J G; Jesudason, E P; Jaji, P J; Inayathullah, M; Dicky John, D G; Vignesh, S; Jayakumar, R

    2012-05-01

    Impaired wound healing in diabetes is a well-documented phenomenon. Emerging data favor the involvement of free radicals in the pathogenesis of diabetic wound healing. We investigated the beneficial role of the sustained release of reactive oxygen species (ROS) in diabetic dermal wound healing. In order to achieve the sustained delivery of ROS in the wound bed, we have incorporated glucose oxidase in the collagen matrix (GOIC), which is applied to the healing diabetic wound. Our in vitro proteolysis studies on incorporated GOIC show increased stability against the proteases in the collagen matrix. In this study, GOIC film and collagen film (CF) are used as dressing material on the wound of streptozotocin-induced diabetic rats. A significant increase in ROS (p < 0.05) was observed in the fibroblast of GOIC group during the inflammation period compared to the CF and control groups. This elevated level up regulated the antioxidant status in the granulation tissue and improved cellular proliferation in the GOIC group. Interestingly, our biochemical parameters nitric oxide, hydroxyproline, uronic acid, protein, and DNA content in the healing wound showed that there is an increase in proliferation of cells in GOIC when compared to the control and CF groups. In addition, evidence from wound contraction and histology reveals faster healing in the GOIC group. Our observations document that GOIC matrices could be effectively used for diabetic wound healing therapy.

  10. Dietary intake, food pattern, and abnormal blood glucose status of middle-aged adults: a cross-sectional community-based study in Myanmar

    PubMed Central

    Hlaing, Hlaing Hlaing; Liabsuetrakul, Tippawan

    2016-01-01

    Background Lifestyle changes, particularly dietary intake, had resulted in increasing trends of type-2 diabetes mellitus worldwide. However, dietary intake is diverse across country contexts. This study aimed to compare the dietary intake, food patterns, and blood glucose among middle-aged adults living in urban and suburban areas in Mandalay city, Myanmar, and explore their relationships. Methods A cross-sectional community-based study was conducted during June–November 2014. Adults aged 35–64 were randomly selected and requested to record all food they ate in a 4-day diary. Fasting and 2-hour postprandial blood glucose values were measured over two consecutive days. Dietary intakes were calculated in terms of energy, macronutrients, glycemic index, and glycemic load, and food patterns were identified by factor analysis. The relationships between food pattern, dietary intake, and blood glucose were assessed. Results Of 440 participants, dietary intake between urban and suburban residents was significantly different. Six food patterns were identified. There was no difference in fasting and 2-hour postprandial blood glucose between urban and suburban residents, but a strong correlation between fasting blood glucose and 2-hour postprandial blood glucose was found (correlation coefficient=0.8). Identification of abnormal blood glucose status using original fasting and converted 2-hour postprandial values showed substantial agreement (prevalence-adjusted bias-adjusted Kappa=0.8). Relationships between food patterns and blood glucose or abnormal blood glucose status were not found. Conclusion Food patterns were associated with dietary intake, not with abnormal blood glucose status. Two-hour postprandial blood glucose was highly correlated with fasting blood glucose and may be used for identifying abnormal blood glucose status. PMID:27150795

  11. Mulberry-extract improves glucose tolerance and decreases insulin concentrations in normoglycaemic adults: Results of a randomised double-blind placebo-controlled study

    PubMed Central

    2017-01-01

    Background High sugar and refined carbohydrate intake is associated with weight gain, increased incidence of diabetes and is linked with increased cardiovascular mortality. Reducing the health impact of poor quality carbohydrate intake is a public health priority. Reducose, a proprietary mulberry leaf extract (ME), may reduce blood glucose responses following dietary carbohydrate intake by reducing absorption of glucose from the gut. Methods A double-blind, randomised, repeat measure, phase 2 crossover design was used to study the glycaemic and insulinaemic response to one reference product and three test products at the Functional Food Centre, Oxford Brooks University, UK. Participants; 37 adults aged 19–59 years with a BMI ≥ 20kg/m2 and ≤ 30kg/m2. The objective was to determine the effect of three doses of mulberry-extract (Reducose) versus placebo on blood glucose and insulin responses when co-administered with 50g maltodextrin in normoglycaemic healthy adults. We also report the gastrointestinal tolerability of the mulberry extract. Results Thirty-seven participants completed the study: The difference in the positive Incremental Area Under the Curve (pIAUC) (glucose (mmol / L x h)) for half, normal and double dose ME compared with placebo was -6.1% (-18.2%, 5.9%; p = 0.316), -14.0% (-26.0%, -2.0%; p = 0.022) and -22.0% (-33.9%, -10.0%; p<0.001) respectively. The difference in the pIAUC (insulin (mIU / L x h)) for half, normal and double dose ME compared with placebo was -9.7% (-25.8%, 6.3%; p = 0.234), -23.8% (-39.9%, -7.8%; p = 0.004) and -24.7% (-40.8%, -8.6%; p = 0.003) respectively. There were no statistically significant differences between any of the 4 groups in the odds of experiencing one or more gastrointestinal symptoms (nausea, abdominal cramping, distension or flatulence). Conclusions Mulberry leaf extract significantly reduces total blood glucose rise after ingestion of maltodextrin over 120 minutes. The pattern of effect demonstrates a

  12. Serum 25-hydroxyvitamin D levels in subjects with reduced glucose tolerance and type 2 diabetes - the Tromsø OGTT-study.

    PubMed

    Hutchinson, Moira S; Figenschau, Yngve; Almås, Bjørg; Njølstad, Inger; Jorde, Rolf

    2011-09-01

    The relationships between vitamin D concentrations, hyperglycemia, and insulin resistance remain uncertain. During 2008 - 2010, an oral glucose tolerance test was performed in 3520 subjects from Tromsø, Norway. Serum 25-hydroxyvitamin D [25(OH)D] was measured in 1193 subjects with normal glucose tolerance, in 304 with isolated impaired fasting glucose, in 254 with isolated impaired glucose tolerance, in 139 with a combination of the two, and in 194 subjects with type 2 diabetes. Serum 25(OH)D did not differ between subjects with isolated impaired fasting glucose or impaired glucose tolerance, but was lower in all groups of deranged glucose metabolism as compared with normal subjects. These differences could not be explained by differences in intakes of vitamin D from cod liver oil or other supplements and remained statistically significant after adjustment for gender, age, body mass index, physical activity score, and month of examination. When the cohort was divided according to serum 25(OH)D quartiles, there was an improvement in all measures of glucose metabolism (fasting and 2-hour plasma glucose, serum insulin, HbA(1c)) and estimates of insulin resistance (QUICKI , HOMA-IR, ISI(0.120)) with increasing serum 25(OH)D quartile. However, interventional studies are needed to prove a causal relationship between vitamin D and glucose metabolism.

  13. The impact of glucose disorders on cognition and brain volumes in the elderly: the Sydney Memory and Ageing Study.

    PubMed

    Samaras, Katherine; Lutgers, Helen L; Kochan, Nicole A; Crawford, John D; Campbell, Lesley V; Wen, Wei; Slavin, Melissa J; Baune, Bernard T; Lipnicki, Darren M; Brodaty, Henry; Trollor, Julian N; Sachdev, Perminder S

    2014-04-01

    Type 2 diabetes predicts accelerated cognitive decline and brain atrophy. We hypothesized that impaired fasting glucose (IFG) and incident glucose disorders have detrimental effects on global cognition and brain volume. We further hypothesized that metabolic and inflammatory derangements accompanying hyperglycaemia contribute to change in brain structure and function. This was a longitudinal study of a community-dwelling elderly cohort with neuropsychological testing (n = 880) and brain volumes by magnetic resonance imaging (n = 312) measured at baseline and 2 years. Primary outcomes were global cognition and total brain volume. Secondary outcomes were cognitive domains (processing speed, memory, language, visuospatial and executive function) and brain volumes (hippocampal, parahippocampal, precuneus and frontal lobe). Participants were categorised as normal, impaired fasting glucose at both assessments (stable IFG), baseline diabetes or incident glucose disorders (incident diabetes or IFG at 2 years). Measures included inflammatory cytokines and oxidative metabolites. Covariates were age, sex, education, non-English speaking background, smoking, blood pressure, lipid-lowering or antihypertensive medications, mood score, apolipoprotein E genotype and baseline cognition or brain volume. Participants with incident glucose disorders had greater decline in global cognition and visuospatial function compared to normal, similar to that observed in baseline diabetes. Homocysteine was independently associated with the observed effect of diabetes on executive function. Apolipoprotein E genotype did not influence the observed effects of diabetes on cognition. Incident glucose disorders and diabetes were also associated with greater 2-year decline in total brain volume, compared to normal (40.0 ± 4.2 vs. 46.7 ± 5.7 mm(3) vs. 18.1 ± 6.2, respectively, p < 0.005). Stable IFG did not show greater decline in global cognition or brain volumes compared

  14. Comparison of sugar molecule decomposition through glucose and fructose: a high-level quantum chemical study.

    SciTech Connect

    Assary, R. S.; Curtiss, L. A.

    2012-02-01

    Efficient chemical conversion of biomass is essential to produce sustainable energy and industrial chemicals. Industrial level conversion of glucose to useful chemicals, such as furfural, hydroxymethylfurfural, and levulinic acid, is a major step in the biomass conversion but is difficult because of the formation of undesired products and side reactions. To understand the molecular level reaction mechanisms involved in the decomposition of glucose and fructose, we have carried out high-level quantum chemical calculations [Gaussian-4 (G4) theory]. Selective 1,2-dehydration, keto-enol tautomerization, isomerization, retro-aldol condensation, and hydride shifts of glucose and fructose molecules were investigated. Detailed kinetic and thermodynamic analyses indicate that, for acyclic glucose and fructose molecules, the dehydration and isomerization require larger activation barriers compared to the retro-aldol reaction at 298 K in neutral medium. The retro-aldol reaction results in the formation of C2 and C4 species from glucose and C3 species from fructose. The formation of the most stable C3 species, dihydroxyacetone from fructose, is thermodynamically downhill. The 1,3-hydride shift leads to the cleavage of the C-C bond in the acyclic species; however, the enthalpy of activation is significantly higher (50-55 kcal/mol) than that of the retro-aldol reaction (38 kcal/mol) mainly because of the sterically hindered distorted four-membered transition state compared to the hexa-membered transition state in the retro-aldol reaction. Both tautomerization and dehydration are catalyzed by a water molecule in aqueous medium; however, water has little effect on the retro-aldol reaction. Isomerization of glucose to fructose and glyceraldehyde to dihydroxyacetone proceeds through hydride shifts that require an activation enthalpy of about 40 kcal/mol at 298 K in water medium. This investigation maps out accurate energetics of the decomposition of glucose and fructose molecules

  15. Air pollution and fasting blood glucose: A longitudinal study in China.

    PubMed

    Chen, Linping; Zhou, Yong; Li, Shanshan; Williams, Gail; Kan, Haidong; Marks, Guy B; Morawska, Lidia; Abramson, Michael J; Chen, Shuohua; Yao, Taicheng; Qin, Tianbang; Wu, Shouling; Guo, Yuming

    2016-01-15

    Limited studies have examined the associations between air pollutants [particles with diameters of 10 μm or less (PM10), sulphur dioxide (SO2), and nitrogen dioxide (NO2)] and fasting blood glucose (FBG). We collected data for 27,685 participants who were followed during 2006 and 2008. Generalized Estimating Equation models were used to examine the effects of air pollutants on FBG while controlling for potential confounders. We found that increased exposure to NO2, SO2 and PM10 was significantly associated with increased FBG levels in single pollutant models (p<0.001). For exposure to 4 days' average of concentrations, a 100 μg/m(3) increase in SO2, NO2, and PM10 was associated with 0.17 mmol/L (95% CI: 0.15-0.19), 0.53 mmol/L (95% CI: 0.42-0.65), and 0.11 mmol/L (95% CI: 0.07-0.15) increase in FBG, respectively. In the multi-pollutant models, the effects of SO2 were enhanced, while the effects of NO2 and PM10 were alleviated. The effects of air pollutants on FBG were stronger in female, elderly, and overweight people than in male, young and underweight people. In conclusion, the findings suggest that air pollution increases the levels of FBG. Vulnerable people should pay more attention on highly polluted days to prevent air pollution-related health issues.

  16. Stopped-flow kinetic studies of the cellulase - catalyzed conversion of cellulose to glucose

    SciTech Connect

    Banerjee, D.K.; Laidler, K.J.

    1983-10-01

    The kinetics of the cellulase-catalyzed conversion of soluble cellulose into glucose have been studied over a range of substrate concentrations and temperatures, and at pH values ranging from 4.75 to 7.0. Lineweaver-Burk plots were linear and led to V = 6.2..mu..M/s and Km = 13.1mM at pH 5.8 and 25.0 degrees C. The pK values corresponding to the free enzyme are 4.8 and 6.8 and are consistent with carboxyl and imidazole groups as the active ionizing species. These pK values were little changed in the enzyme-substrate intermediate that reacts in the rate-determining step, suggesting that the ionizing groups are still free in this intermediate. The activation energy corresponding to V/Km is 80.6 kJ/mol, and that corresponding to V is 38.7 kJ/mol. The corresponding entropies of activation are 21 J K/sup -1/mol/sup -1/ and -157 J K/sup -1/mol/sup -1/, respectively. 22 references.

  17. Spacelab data management subsystem phase B study

    NASA Technical Reports Server (NTRS)

    1974-01-01

    The Spacelab data management system is described. The data management subsystem (DMS) integrates the avionics equipment into an operational system by providing the computations, logic, signal flow, and interfaces needed to effectively command, control, monitor, and check out the experiment and subsystem hardware. Also, the DMS collects/retrieves experiment data and other information by recording and by command of the data relay link to ground. The major elements of the DMS are the computer subsystem, data acquisition and distribution subsystem, controls and display subsystem, onboard checkout subsystem, and software. The results of the DMS portion of the Spacelab Phase B Concept Definition Study are analyzed.

  18. Association between Physical Activity and Metabolic Risk Factors in Adolescents: Tehran Lipid and Glucose Study

    PubMed Central

    Fam, Bita; Amouzegar, Atieh; Arzhan, Soraya; Ghanbariyan, Arash; Delshad, Maryam; Hosseinpanah, Farhad; Azizi, Fereidoun

    2013-01-01

    Background: Physical activity (PA) is associated with the metabolic syndrome (MetS) and its components. This study aimed to examine the association between PA and MetS and its components among normal weight and overweight/obese adolescent in Tehran Lipid and Glucose Study (TLGS). Methods: This cross-sectional study includes 777 adolescents, aged 12-18 years, who were selected by multi-stage random cluster sampling from among TLGS participants. Subjects were classified as normal weight and overweight/obese based on the age- and sex-specific standardized percentile curves of BMI for Iranian population. Levels of PA were assessed using a standardized and modifiable activity questionnaire (MAQ), and categorized into tertiles. MetS was defined according to the Cook's criteria. Results: Prevalence of the MetS was higher in overweight/obese than normal group (35% vs. 3%; P: 0.02). Normal groups were more physically active (50% vs. 44%); however, difference was not significant. There was a significant association between the light PA and risk of lower level of HDL-C before and after adjustment, in normal weight group (OR: 1.61, CI 95%: 1.11, 2.35; OR: 1.65, CI 95%: 1.12, 2.44, respectively). The overweight/obese group with light and moderate PA had a higher risk of having abdominal obesity than those with vigorous PA, only after adjustment for determined covariates (OR: 1.11, CI 95%: 1.07, 1.21; OR: 1.06, CI 95%: 1.01, 1.08, respectively); the association between MetS and PA was not significant. Conclusions: The results of this study confirm the association between PA and some individual components of MetS such as waist and HDL-C. PMID:24130941

  19. Reconsidering the activation entropy for anomerization of glucose and mannose in water studied by NMR spectroscopy

    NASA Astrophysics Data System (ADS)

    Kosaka, Ami; Aida, Misako; Katsumoto, Yukiteru

    2015-08-01

    The anomerization of monosaccharides is a very important process to understand how their stereoisomers are stabilized in aqueous solutions. For glucose and mannose, it has been known that α- and β-anomers of hexopyranose exist as the major components. In order to examine the anomerization pathway for glucose and mannose in aqueous solutions, it is indispensable to determine the thermodynamic parameters such as the activation energy, the activation Gibbs free energy (ΔG‡), enthalpy (ΔH‡), and entropy (ΔS‡). Although several research groups reported these quantities in aqueous solution, they have still been controversial especially for ΔS‡. In this paper, we employ 1H NMR spectroscopy for monitoring the population of both α- and β-anomers of glucose and mannose. The contribution of ΔS‡ to ΔG‡ for glucose in water is estimated to be ca. 30%, while that for mannose is 8.0%. The large difference in ΔS‡ suggests that the anomerization pathway is not the same for glucose and mannose.

  20. Radiation inactivation studies on the rabbit kidney sodium-dependent glucose transporter.

    PubMed

    Takahashi, M; Malathi, P; Preiser, H; Jung, C Y

    1985-09-05

    Rabbit kidney cortical brush-border membrane vesicles were irradiated in the frozen state with increasing doses of high energy electrons from a Van de Graaff generator. Sodium-dependent D-glucose and L-alanine transport showed a simple exponential loss of activity with increasing radiation dosage. Target size calculation based on these data gives estimates of 1.0 X 10(6) daltons for the glucose transporter and 1.2 X 10(6) daltons for the alanine transporter. A highly purified glucose transport protein extracted from rabbit kidney cortex was similarly irradiated both before and after reconstitution into liposomes. The target size of this purified glucose transporter was 343,000 daltons, based on inactivation of transport. The intensity of the major 165,000-dalton sodium dodecyl sulfate-gel electrophoresis band of this preparation was decreased by radiation. The decrease in staining intensity was dose-dependent, yielding a target size of 298,000 daltons, in situ. We propose that the purified glucose transporter reconstituted into liposomes is a tetramer comprised of 85,000-dalton subunits.

  1. Intelligent Robotic Systems Study (IRSS), phase 4

    NASA Technical Reports Server (NTRS)

    1991-01-01

    Under the Intelligent Robotics Systems Study (IRSS), a generalized robotic control architecture was developed for use with the ProtoFlight Manipulator Arm (PFMA). Based upon the NASREM system design concept, the controller built for the PFMA provides localized position based force control, teleoperation, and advanced path recording and playback capabilities. The PFMA has six computer controllable degrees of freedom (DOF) plus a 7th manually indexable DOF, making the manipulator a pseudo 7 DOF mechanism. Joints on the PFMA are driven via 7 pulse width modulated amplifiers. Digital control of the PFMA is implemented using a variety of single board computers. There were two major activities under the IRSS phase 4 study: (1) enhancement of the PFMA control system software functionality; and (2) evaluation of operating modes via a teleoperation performance study. These activities are described and results are given.

  2. Phase I study of NKT-01.

    PubMed

    Tamura, K; Niitani, H; Oguro, M; Ohno, R; Sanpi, K; Majima, H; Masaoka, T; Kimura, I; Inagaki, J; Suzuoki, Y

    1995-01-01

    A phase I study of NKT-01 (deoxyspergualin), which is a derivative of an antitumor antibiotic, spergualin, was performed by a cooperative study group. NKT-01 was given intravenously by 3-h infusion. The effect of single administration was studied prior to evaluation of daily administration for 5 consecutive days. In all, 5 and 33 patients with various malignancies, including leukemia, were entered into the trials of single and daily administration, respectively. In the single-administration study, all patients were evaluable and no clear adverse effect was observed at doses ranging from 20 to 320 mg/m2. In the daily-administration study, 28 evaluable patients (16 men and 12 women; median age, 55.5 years) were treated with a daily dose of 20-500 mg/m2. Toxicities such as myelosuppression, mild nausea/vomiting, anorexia, alopecia, tongue and perioral numbness, and hypotension were observed dose-dependently during or after the treatment. Grade 2 leukopenia, thrombocytopenia, and anemia were experienced at a dose of 500 mg/m2. These usually recovered to normal values by approximately 3 weeks after treatment. A pharmacokinetic analysis of single administration revealed rapid plasma clearance, with mean half-lives for the alpha and beta phases being 28 min and 6.9 h, respectively. Approximately 12% of the infused dose was excreted into the urine in unmetabolized form. The pharmacokinetic parameters obtained after 5-day administration were similar to those recorded after single administration. Concerning treatment response, a transient but significant reduction in the number of leukemic cells was observed in one patient with adult T-cell leukemia. In this study, perioral numbness, hypotension, and hematological toxicity were concluded to be dose-limiting, with the maximal acceptable dose being 500 mg/m2. The recommended dose for a phase II study of NKT-01 against solid tumors was judged to be 400 mg/m2 given daily by 3-h infusion for 5 days, every 3 weeks. In

  3. Micronutrient Intakes and Incidence of Chronic Kidney Disease in Adults: Tehran Lipid and Glucose Study

    PubMed Central

    Farhadnejad, Hossein; Asghari, Golaleh; Mirmiran, Parvin; Yuzbashian, Emad; Azizi, Fereidoun

    2016-01-01

    The aim of this study was to investigate the associations between micronutrient intakes and the 3.6-year incidence of chronic kidney disease (CKD) in adults. This cohort study was conducted, within the framework of the Tehran Lipid and Glucose Study, on 1692 subjects, aged ≥30 years, without CKD at the baseline. Dietary intakes were collected using a valid and reliable food-frequency questionnaire. Anthropometrics and biochemical measurements were taken. Chronic kidney disease was defined as eGFR < 60 mL/min/1.73 m2. The mean age of participants was 43.3 ± 11.4 years. In the fully adjusted model, individuals in the top quintile of folate (OR: 0.44, 95% CI: 0.24–0.80), cobalamin (OR: 0.57, 95% CI: 0.34–0.93), vitamin C (OR: 0.38, 95% CI: 0.21–0.69), vitamin E (OR: 0.45, 95% CI: 0.22–0.92), vitamin D (OR: 0.39, 95% CI: 0.21–0.70), potassium (OR: 0.47, 95% CI: 0.23–0.97) and magnesium (OR: 0.41, 95% CI: 0.22–0.76) had decreased risk of CKD, and in the top quintile of sodium (OR: 1.64, 95% CI: 1.03–2.61), subjects had increased risk of CKD, in comparison to the bottom quintile. No significant associations were found between the intakes of other micronutrients. High intake of several micronutrients including vitamins C, E, D, cobalamin, folate, magnesium, and potassium was associated with a decreased risk, while sodium was associated with an increased risk of incident CKD. PMID:27104561

  4. Effects of a sodium glucose co-transporter 2 selective inhibitor, ipragliflozin, on the diurnal profile of plasma glucose in patients with type 2 diabetes: A study using continuous glucose monitoring

    PubMed Central

    Yamada, Kentaro; Nakayama, Hitomi; Yoshinobu, Satoko; Kawano, Seiko; Tsuruta, Munehisa; Nohara, Masayuki; Hasuo, Rika; Akasu, Shoko; Tokubuchi, Ichiro; Wada, Nobuhiko; Hirao, Saori; Iwata, Shinpei; Kaku, Hiroo; Tajiri, Yuji

    2015-01-01

    Aims/Introduction To assess the effects of sodium glucose co-transporter 2 inhibitor therapy on the pathophysiology of type 2 diabetes. Materials and Methods We administered ipragliflozin to 21 inpatients with type 2 diabetes for 7 days, and analyzed the diurnal profiles of plasma glucose and 3-hydroxybutyrate. A total of 21 age-, sex- and body mass index-matched diabetic patients served as controls. Results Continuous glucose monitoring showed that the 24-h glucose curve was shifted downward without hypoglycemia by the administration of ipragliflozin. The average glucose level was reduced from 182 ± 54 mg/dL to 141 ± 33 mg/dL (P < 0.0001). The magnitude of the reduction was highly correlated with the baseline average glucose level. Homeostasis model assessment of insulin resistance was decreased, and homeostasis model assessment of β-cell function was increased during the treatment. Urinary glucose excretion was correlated with the average glucose level both on day 0 and on day 7, although the regression line was steeper and shifted leftward on day 7. The ipragliflozin-treated patients lost more weight than the control patients (1.4 ± 0.5 vs 0.5 ± 0.6 kg, P < 0.0001). Plasma levels of 3-hydroxybutyrate were significantly increased with peaks before breakfast and before dinner. Patient age and bodyweight loss were negatively and positively correlated with the peak levels of 3-hydroxybutyrate on day 7, respectively. Conclusions The ipragliflozin treatment improved the 24-h glucose curve without causing hypoglycemia. The close correlation between the magnitude of glucose reduction and the baseline plasma glucose concentration suggests that the risk of hypoglycemia is likely low. It might be prudent to monitor ketone body levels in younger patients and in patients with rapid weight loss. PMID:26543545

  5. Flow reactor studies of the paired electro-oxidation and electroreduction of glucose

    SciTech Connect

    Park, K.; Baizer, M.M.; Nobe, K.; Pintauro

    1985-08-01

    The electrochemical oxidation of glucose to gluconic acid and reduction of glucose to sorbitol hav been paired in an undivided packed-bed electrode flow reactor. A Raney Ni powder electrocatalyst significantly improved the current efficiency for sorbitol production, as compared to a high hydrogen overpotential Zn(Hg) cathode. The optimum operating conditions for the paired syntheses are activity W-2 Raney Ni powder cathode, graphite chip anode, a 1.6M glucose and 0.4M CaBr/sub 2/ initial solution composition, pH 5-7, 60/sup 0/C solution temperature, an applied current of 250-500 mA per 10g of nickel powder cathode and a solution volumetric flow rate of 100 ml-min/sup -1/. Under these conditions, the sorbitol current efficiencies are 80-100%, the gluconic acid efficiencies are 100%, and the product yields are very high.

  6. Type 2 Diabetes-Associated K+ Channel TALK-1 Modulates β-Cell Electrical Excitability, Second-Phase Insulin Secretion, and Glucose Homeostasis.

    PubMed

    Vierra, Nicholas C; Dadi, Prasanna K; Jeong, Imju; Dickerson, Matthew; Powell, David R; Jacobson, David A

    2015-11-01

    Two-pore domain K+ (K2P) channels play an important role in tuning β-cell glucose-stimulated insulin secretion (GSIS). The K2P channel TWIK-related alkaline pH-activated K2P (TALK)-1 is linked to type 2 diabetes risk through a coding sequence polymorphism (rs1535500); however, its physiological function has remained elusive. Here, we show that TALK-1 channels are expressed in mouse and human β-cells, where they serve as key regulators of electrical excitability and GSIS. We find that the rs1535500 polymorphism, which results in an alanine-to-glutamate substitution in the C-terminus of human TALK-1, increases channel activity. Genetic ablation of TALK-1 results in β-cell membrane potential depolarization, increased islet Ca2+ influx, and enhanced second-phase GSIS. Moreover, mice lacking TALK-1 channels are resistant to high-fat diet-induced elevations in fasting glycemia. These findings reveal TALK-1 channels as important modulators of second-phase insulin secretion and suggest a clinically relevant mechanism for rs1535500, which may increase type 2 diabetes risk by limiting GSIS.

  7. Type 2 Diabetes–Associated K+ Channel TALK-1 Modulates β-Cell Electrical Excitability, Second-Phase Insulin Secretion, and Glucose Homeostasis

    PubMed Central

    Vierra, Nicholas C.; Dadi, Prasanna K.; Jeong, Imju; Dickerson, Matthew; Powell, David R.

    2015-01-01

    Two-pore domain K+ (K2P) channels play an important role in tuning β-cell glucose-stimulated insulin secretion (GSIS). The K2P channel TWIK-related alkaline pH-activated K2P (TALK)-1 is linked to type 2 diabetes risk through a coding sequence polymorphism (rs1535500); however, its physiological function has remained elusive. Here, we show that TALK-1 channels are expressed in mouse and human β-cells, where they serve as key regulators of electrical excitability and GSIS. We find that the rs1535500 polymorphism, which results in an alanine-to-glutamate substitution in the C-terminus of human TALK-1, increases channel activity. Genetic ablation of TALK-1 results in β-cell membrane potential depolarization, increased islet Ca2+ influx, and enhanced second-phase GSIS. Moreover, mice lacking TALK-1 channels are resistant to high-fat diet–induced elevations in fasting glycemia. These findings reveal TALK-1 channels as important modulators of second-phase insulin secretion and suggest a clinically relevant mechanism for rs1535500, which may increase type 2 diabetes risk by limiting GSIS. PMID:26239056

  8. Response surface methodology to optimize partition and purification of two recombinant oxidoreductase enzymes, glucose dehydrogenase and d-galactose dehydrogenase in aqueous two-phase systems.

    PubMed

    Shahbaz Mohammadi, Hamid; Mostafavi, Seyede Samaneh; Soleimani, Saeideh; Bozorgian, Sajad; Pooraskari, Maryam; Kianmehr, Anvarsadat

    2015-04-01

    Oxidoreductases are an important family of enzymes that are used in many biotechnological processes. An experimental design was applied to optimize partition and purification of two recombinant oxidoreductases, glucose dehydrogenase (GDH) from Bacillus subtilis and d-galactose dehydrogenase (GalDH) from Pseudomonas fluorescens AK92 in aqueous two-phase systems (ATPS). Response surface methodology (RSM) with a central composite rotatable design (CCRD) was performed to optimize critical factors like polyethylene glycol (PEG) concentration, concentration of salt and pH value. The best partitioning conditions was achieved in an ATPS composed of 12% PEG-6000, 15% K2HPO4 with pH 7.5 at 25°C, which ensured partition coefficient (KE) of 66.6 and 45.7 for GDH and GalDH, respectively. Under these experimental conditions, the activity of GDH and GalDH was 569.5U/ml and 673.7U/ml, respectively. It was found that these enzymes preferentially partitioned into the top PEG-rich phase and appeared as single bands on SDS-PAGE gel. Meanwhile the validity of the response model was confirmed by a good agreement between predicted and experimental results. Collectively, according to the obtained data it can be inferred that the ATPS optimization using RSM approach can be applied for recovery and purification of any enzyme from oxidoreductase family.

  9. Intake of kale suppresses postprandial increases in plasma glucose: A randomized, double-blind, placebo-controlled, crossover study

    PubMed Central

    Kondo, Sumio; Suzuki, Asahi; Kurokawa, Mihoko; Hasumi, Keiji

    2016-01-01

    Kale (Brassica oleracea var. acephala), a vegetable in the family Brassicaceae, has beneficial effects on health, including hypoglycemic effects. In our previous study with a limited number of subjects, intake of kale-containing food at a dose of 14 g decreased postprandial plasma glucose levels. In the present study, the effective dose of kale-containing food was investigated in a randomized, double-blind, placebo-controlled, crossover trial. The trial was conducted on 42 Japanese subjects aged 21–64 years with fasting plasma glucose levels of ≤125 mg/dl and 30-min postprandial plasma glucose levels of 140–187 mg/dl. The subjects consumed placebo or kale-containing food [7 or 14 g; low-dose (active-L) or high-dose (active-H) kale, respectively] together with a high-carbohydrate meal. At 30–120 min after the test meal intake, the plasma levels of glucose and insulin were determined. The postprandial plasma glucose levels in subjects with intake of active-L or active-H were significantly lower than those in subjects with intake of placebo, with the maximum plasma concentration (Cmax; 163±24 mg/dl for active-L and 162±23 mg/dl for active-H compared with 176±26 mg/dl for placebo [values presented as means ± standard deviation (SD); P<0.01]. The area under the plasma glucose concentration-time curve for 0–2 h (AUC0–2 h) values (means ± SD) were significantly lower for active-L (268±43 mg/h/dl) and active-H (266±42 mg/h/dl) than for the placebo (284±43 mg/h/dl; P<0.05). No significant differences were identified in the postprandial plasma insulin levels between the three conditions. No adverse events associated with intake of either dose of kale were observed. Our findings suggest that intake of kale suppresses postprandial increases in plasma glucose levels at a single dose of 7 g, and that a dose as high as 14 g is safe. PMID:27882216

  10. Intake of kale suppresses postprandial increases in plasma glucose: A randomized, double-blind, placebo-controlled, crossover study.

    PubMed

    Kondo, Sumio; Suzuki, Asahi; Kurokawa, Mihoko; Hasumi, Keiji

    2016-11-01

    Kale (Brassica oleracea var. acephala), a vegetable in the family Brassicaceae, has beneficial effects on health, including hypoglycemic effects. In our previous study with a limited number of subjects, intake of kale-containing food at a dose of 14 g decreased postprandial plasma glucose levels. In the present study, the effective dose of kale-containing food was investigated in a randomized, double-blind, placebo-controlled, crossover trial. The trial was conducted on 42 Japanese subjects aged 21-64 years with fasting plasma glucose levels of ≤125 mg/dl and 30-min postprandial plasma glucose levels of 140-187 mg/dl. The subjects consumed placebo or kale-containing food [7 or 14 g; low-dose (active-L) or high-dose (active-H) kale, respectively] together with a high-carbohydrate meal. At 30-120 min after the test meal intake, the plasma levels of glucose and insulin were determined. The postprandial plasma glucose levels in subjects with intake of active-L or active-H were significantly lower than those in subjects with intake of placebo, with the maximum plasma concentration (Cmax; 163±24 mg/dl for active-L and 162±23 mg/dl for active-H compared with 176±26 mg/dl for placebo [values presented as means ± standard deviation (SD); P<0.01]. The area under the plasma glucose concentration-time curve for 0-2 h (AUC0-2 h) values (means ± SD) were significantly lower for active-L (268±43 mg/h/dl) and active-H (266±42 mg/h/dl) than for the placebo (284±43 mg/h/dl; P<0.05). No significant differences were identified in the postprandial plasma insulin levels between the three conditions. No adverse events associated with intake of either dose of kale were observed. Our findings suggest that intake of kale suppresses postprandial increases in plasma glucose levels at a single dose of 7 g, and that a dose as high as 14 g is safe.

  11. Effects of deprivation of oxygen or glucose on the neural activity in the guinea pig hippocampal slice--intracellular recording study of pyramidal neurons.

    PubMed

    Takata, T; Okada, Y

    1995-06-12

    The block of synaptic transmission and neural activity during deprivation of oxygen or glucose has been simply attributed to the lack of energy due to the disorder of energy production. To clarify the interrelation between neural activity and energy metabolism during hypoxia or glucose deprivation, we studied the changes in ATP levels and electrical events of pyramidal neurons in the CA3 region and [Ca2+]i mobilization of the dendritic and cellular region of CA3 area, using guinea pig hippocampal slices. The studies of field potentials and intracellular recording from the pyramidal cell of CA3 area during hypoxia or glucose deprivation revealed that the cessation of synaptic activity and the depolarization of resting potential occurred earlier than during glucose deprivation while the increase of [Ca2+]i was slow during hypoxia but rapid during glucose deprivation although the ATP level of CA3 area was maintained at its original level for 20 min during both conditions. When glucose was replaced by lactate, ATP concentration was not reduced but the electrical activity decayed and [Ca2+]i increased with the similar time course as observed during lack of glucose, only. These results suggest that different mechanisms underlie the block of synaptic transmission in the CA3 pyramidal neurons during hypoxia and glucose deprivation and that lactate cannot substitute for glucose in the maintenance of neural activity.

  12. Auditory adaptation to sound intensity in conscious rats: 2-[F-18]-fluoro-2-deoxy-D-glucose PET study.

    PubMed

    Jang, Dong Pyo; Lee, Kyoung Min; Lee, Sang-Yoon; Oh, Jin-Hwan; Park, Chan-Woong; Kim, In Young; Kim, Young-Bo; Cho, Zang-Hee

    2012-03-07

    Despite the importance of the adaptive process for discriminating the broad range of sound intensity, there have been few systemic investigations targeting the auditory mechanisms. In this study, the adaptation effect of sound intensity on the change in glucose metabolism in rat brains was examined using a PET technique. In the first experiment, broadband white noise sound (40, 60, 80, or 100 dB sound pressure level) was given for 30 min after an 2-[F-18]-fluoro-2-deoxy-D-glucose injection in an awake condition. In the second experiment, sound stimuli with an intensity modulation of 0, 0.5, and 5.0 Hz in frequency and at three intensity levels were used for examining the metabolism change according to the short time scale variation of the sound intensity. As a result, the metabolic activities in the bilateral cochlear nucleus, superior olivary complexes, and inferior colliculus were proportional to the sound intensity level, whereas the bilateral auditory cortical areas unexpectedly decreased as the sound intensity level increased in the first experiment. In the second experiment, the glucose metabolism in the auditory cortex was higher at 0.5 and 5.0 Hz modulation frequency than the 0.0 Hz modulation frequency, while retaining an inverse relationship with the sound intensity. The metabolism in inferior colliculus was higher at 5.0 Hz modulation frequency than 0.0 and 0.5 Hz modulation frequencies. Taken together, the auditory cortex metabolism seemed to be actively adapted to the average sound intensity, which indicates that it plays an important role in processing the broad range to sound intensity more than the other nucleus of the auditory pathway. Especially, this study demonstrated that the sound intensity-dependent glucose metabolism can be seen in a small rodent's brain stem level using 2-[F-18]-fluoro-2-deoxy-D-glucose PET functional neuroimaging.

  13. The association between diabetes mellitus, glucose, and chronic musculoskeletal complaints. Results from the Nord-Trøndelag Health Study

    PubMed Central

    Hoff, Ole M; Midthjell, Kristian; Zwart, John-Anker; Hagen, Knut

    2008-01-01

    Background The relationship between diabetes mellitus (DM) and chronic musculoskeletal complaints (MSCs) is unclear. The aim of this study was to investigate the association between DM, non-fasting glucose and chronic MSCs defined as pain and/or stiffness ≥ 3 months during the past year in the general adult population. Methods The results were based on cross-sectional data from 64,785 men and women (aged ≥ 20 years) who participated in the Nord-Trøndelag Health Survey, which included 1,940 individuals with known DM. Associations were assessed using multiple logistic regression, estimating prevalence odds ratio (OR) with 95% confidence intervals (CIs). Results High non-fasting glucose was associated with a lower prevalence of chronic MSCs compared to a low glucose level. DM was associated with higher prevalence of chronic MSCs, in particular chronic widespread MSCs. In the multivariate analysis, adjusting for glucose level, BMI, age, gender and physical activity, chronic widespread MSCs was 1.6 times more likely (OR = 1.6, 95% CI 1.2–2.2) among individuals < 60 years of age with DM than among those without DM. The association between chronic widespread MSCs and DM was most evident among the group of individuals aged < 60 years with either type 2 DM or unclassified DM (OR = 1.8, 95% CI 1.3–2.5). Conclusion In this cross-sectional study a high non-fasting glucose was associated with lower prevalence of chronic MSCs. Among individuals with known DM chronic widespread MSCs were more likely. PMID:19055732

  14. Space shuttle phase B study plan

    NASA Technical Reports Server (NTRS)

    Hello, B.

    1971-01-01

    Phase B emphasis was directed toward development of data which would facilitate selection of the booster concept, and main propulsion system for the orbiter. A shuttle system is also defined which will form the baseline for Phase C program activities.

  15. Clinical implication of blood glucose monitoring in general dental offices: the Ehime Dental Diabetes Study

    PubMed Central

    Harase, Tadahiro; Nishida, Wataru; Hamakawa, Tomohiro; Hino, Satoshi; Shigematsu, Kenji; Kobayashi, Satoru; Sako, Hirofumi; Ito, Shirou; Murakami, Hajime; Nishida, Kei; Inoue, Hiroshi; Fujisawa, Masahito; Yoshizu, Hiroshi; Kawamura, Ryoichi; Takata, Yasunori; Onuma, Hiroshi; Shimizu, Keita; Hamakawa, Hiroyuki; Osawa, Haruhiko

    2015-01-01

    Objective We examined whether general dentists can contribute to the detection of patients with undiagnosed diabetes and prediabetes by monitoring blood glucose in dental clinics. Research design and methods A total of 716 patients who visited clinics for dental treatment were enrolled and classified into 3 groups (mild, moderate, and severe) according to Kornman's criteria for periodontitis. The correlations between the casual blood glucose level, presence or absence of the history of diabetes, and/or severity of periodontitis were evaluated. Results 68 patients (9.5%) had hyperglycemia (blood glucose ≥200 mg/dL). Of these patients, 20 (29.4%) did not have a history of diabetes. Blood glucose tended to be higher with greater periodontitis severity. Of the 3 groups, the severe periodontitis group had the highest proportion of patients with hyperglycemia (p<0.0001). Conclusions Patients with dental problems could be screened for diabetes, especially undiagnosed diabetes. General dentists could function as practitioners to screen for diabetes. Trial registration number UMIN-CTR 000014877. PMID:26629348

  16. Monitoring of glucose, salt and pure water in human whole blood: An in vitro study.

    PubMed

    Imran, Muhammad; Ullah, Hafeez; Akhtar, Munir; Sial, Muhammad Aslam; Ahmed, Ejaz; Durr-E-Sabeeh; Ahmad, Mukhtar; Hussain, Fayyaz

    2016-07-01

    Designing and implementation of non-invasive methods for glucose monitoring in blood is main focus of biomedical scientists to provide a relief from skin puncturing of diabete patient. The objective of this research work is to investigate the shape deformations and the aggregation of red blood cells (RBCs) in the human blood after addition of three different analytes i) (0mM-400mM: Range) of glucose (C(6)H(12)O(6)), ii) (0mM-400mM: range) of pure salt (NaCl) and iii) (0mM- 350mM: range) of pure water (H(2)O). We have observed that the changes in the shape of individual cells from biconcave discs to spherical shapes and eventually the lysis of the cells at optimum concentration of glucose, salts and pure water. This demonstration also provides a base line to facilitate diabetes during partial diagnosis and monitoring of the glucose levels qualitatively both in research laboratories and clinical environment.

  17. DFTMD Studies of Glucose and Epimers: Anomeric Ratios Rotamer Populations, and Hydration Energies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Results are presented from density functional molecular dynamics (DFTMD) simulations, based on constant energy dynamics, of glucose and its cyclic form of 6-carbon epimers. Both in vacuo and an implicit solvent method (COSMO) were examined including simulations of all low energy conformations of ea...

  18. Small compound inhibitors of basal glucose transport inhibit cell proliferation and induce apoptosis in cancer cells via glucose-deprivation-like mechanisms.

    PubMed

    Liu, Yi; Zhang, Weihe; Cao, Yanyan; Liu, Yan; Bergmeier, Stephen; Chen, Xiaozhuo

    2010-12-08

    Cancer cells depend heavily on glucose as both energy and biosynthesis sources and are found to upregulate glucose transport and switch their main energy supply pathway from oxidative phosphorylation to glycolysis. These molecular and metabolic changes also provide targets for cancer treatment. Here we report that novel small molecules inhibited basal glucose transport and cell proliferation, and induced apoptosis in lung and breast cancer cells without affecting much their normal cell counterparts. Cancer cells survived the compound treatment lost their capability to proliferate. Mechanistic study indicates that the cancer cell inhibition by the test compounds has a component of apoptosis and the induced apoptosis was p53-independent and caspase 3-dependent, similar to those resulted from glucose deprivation. Compound treatment also led to cell cycle arrest in G1/S phase. The inhibition of cancer cell growth was partially relieved when additional glucose was supplied to cells, suggesting that the inhibition was due to, at least in part, the inhibition of basal glucose transport. When used in combination, the test compounds demonstrated synergistic effects with anticancer drugs cisplatin or paclitaxel in inhibition of cancer cell growth. All these results suggest that these glucose transport inhibitors mimic glucose deprivation and work through inhibiting basal glucose transport. These inhibitors have the potential to complement and replace traditional glucose deprivation, which cannot be used in animals, as new tools to study the effects of glucose transport and metabolism on cancer and normal cells.

  19. Second generation biofuels: Thermochemistry of glucose and fructose

    SciTech Connect

    Osmont, A.; Escot Bocanegra, P.; Goekalp, I.; Thollas, B.; Kozinski, J.A.

    2010-06-15

    The energetic conversion of biomass into syngas or biogas is a more and more important topic. In the framework of these studies, improved understanding of glucose and fructose thermal decomposition and oxidation appears crucial. For this task, thermodynamic data are needed to make possible, for instance, the building of a detailed chemical kinetic model of glucose and fructose reactivity at high temperature. A semitheoretical protocol, presented elsewhere, is used for the estimation of the thermodynamic data of glucose and fructose in the gas phase. Five isomers of glucose and five isomers of fructose are considered and the lowest-energy conformers are found to be {beta}-D-glucopyranose for glucose and {beta}-D-fructopyranose for fructose. The data for all 10 isomers are provided in the CHEMKIN-NASA format. (author)

  20. Pre-collapse phase studies before Herschel

    NASA Astrophysics Data System (ADS)

    Tafalla, M.

    2012-03-01

    The role of molecular clouds as factories of stars has been recognized for decades, but understanding how a large cloud of tens of thousands or more solar masses fragments into stellar-sized pockets with an efficiency of only a few percent and an IMF spectrum is still a puzzling mystery. In this talk, I will review how our observational understanding of the stages prior to star formation has evolved with time, from the earliest molecular studies to the pre-Herschel era. Both the large scale of clouds and the small structure of dense cores will be covered, following the results from molecular-line observation and dust emission/extinction studies. Although Herschel observations are clearly revolutionizing our view of cloud and core formation, parallel work on the kinematics of the cloud gas is also shedding new light on the pre-collapse phases. I will end my presentation showing how large-scale kinematics studies, highly complementary to the Herschel continuum data, reveal a sequence of fragmentation that seems responsible for core formation.

  1. Retrobiosynthetic NMR studies with 13C-labeled glucose. Formation of gallic acid in plants and fungi.

    PubMed

    Werner, I; Bacher, A; Eisenreich, W

    1997-10-10

    The biosynthesis of gallic acid was studied in cultures of the fungus Phycomyces blakesleeanus and in leaves of the tree Rhus typhina. Fungal cultures were grown with [1-13C]glucose or with a mixture of unlabeled glucose and [U-13C6]glucose. Young leaves of R. typhina were kept in an incubation chamber and were supplied with a solution containing a mixture of unlabeled glucose and [U-13C6]glucose via the leaf stem. Isotope distributions in isolated gallic acid and aromatic amino acids were analyzed by one-dimensional 1H and 13C NMR spectroscopy. A quantitative analysis of the complex isotopomer composition of metabolites was obtained by deconvolution of the 13C13C coupling multiplets using numerical simulation methods. This approach required the accurate analysis of heavy isotope chemical shift effects in a variety of different isotopomers and the analysis of long range 13C13C coupling constants. The resulting isotopomer patterns were interpreted using a retrobiosynthetic approach based on a comparison between the isotopomer patterns of gallic acid and tyrosine. The data show that both in the fungus and in the plant all carbon atoms of gallic acid are biosynthetically equivalent to carbon atoms of shikimate. Notably, the carboxylic group of gallic acid is derived from the carboxylic group of an early intermediate of the shikimate pathway and not from the side chain of phenylalanine or tyrosine. It follows that the committed precursor of gallic acid is an intermediate of the shikimate pathway prior to prephenate or arogenate, most probably 5-dehydroshikimate. A formation of gallic acid via phenylalanine, the lignin precursor, caffeic acid, or 3,4, 5-trihydroxycinnamic acid can be ruled out as major pathways in the fungus and in young leaves of R. typhina. The incorporation of uniformly 13C-labeled glucose followed by quantitative NMR analysis of isotopomer patterns is suggested as a general method for biosynthetic studies. As shown by the plant experiment, this

  2. The glucose intolerance of acute pancreatitis: hormonal response to arginine.

    PubMed

    Solomon, S S; Duckworth, W C; Jallepalli, P; Bobal, M A; Iyer, R

    1980-01-01

    Patients with acute pancreatitis were studied by arginine infusion at 48--72 h. 7--10 days, and 18--21 days after onset of their illness. Plasma glucose, insulin, and glucagon values were determined. Acute pancreatitis was characterized by fasting hyperglycemia and hyperglucagonemia, associated with relative hyoinsulinemia. Arginine stimulation early in the disease (48--72 h) demonstrated hyperglycemia and hyperglucagonemia, which normalized by 18--21 days. Both phases of the normal biphasic insulin response to arginine were decreased during the initial arginine infusion. By 18--21 days, although the first phase was completely normal, the second phase of insulin secretion remained depressed. Acute pancreatitis is associated with damage to both the endocrine and exocrine pancreas. Glucose intolerance seen with this disease appears to be the result of hyperglucagonemia and relative hypoinsulinemia. Although the healing process at 3 wk is associated with return of plasma glucose and glucagon concentrations to normal, the impaired second phase insulin secretion persists.

  3. Golgi apparatus dis- and reorganizations studied with the aid of 2-deoxy-D-glucose and visualized by 3D-electron tomography.

    PubMed

    Ranftler, Carmen; Meisslitzer-Ruppitsch, Claudia; Neumüller, Josef; Ellinger, Adolf; Pavelka, Margit

    2017-04-01

    We studied Golgi apparatus disorganizations and reorganizations in human HepG2 hepatoblastoma cells by using the nonmetabolizable glucose analogue 2-deoxy-D-glucose (2DG) and analyzing the changes in Golgi stack architectures by 3D-electron tomography. Golgi stacks remodel in response to 2DG-treatment and are replaced by tubulo-glomerular Golgi bodies, from which mini-Golgi stacks emerge again after removal of 2DG. The Golgi stack changes correlate with the measured ATP-values. Our findings indicate that the classic Golgi stack architecture is impeded, while cells are under the influence of 2DG at constantly low ATP-levels, but the Golgi apparatus is maintained in forms of the Golgi bodies and Golgi stacks can be rebuilt as soon as 2DG is removed. The 3D-electron microscopic results highlight connecting regions that interlink membrane compartments in all phases of Golgi stack reorganizations and show that the compact Golgi bodies mainly consist of continuous intertwined tubules. Connections and continuities point to possible new transport pathways that could substitute for other modes of traffic. The changing architectures visualized in this work reflect Golgi stack dynamics that may be essential for basic cell physiologic and pathologic processes and help to learn, how cells respond to conditions of stress.

  4. The space transportation main engine phase A' study

    NASA Technical Reports Server (NTRS)

    1987-01-01

    The Space Transportation Main Engine Phase A prime study was conducted over a 7 month period as an extension to the Phase A study. The Phase A prime program was designed to expand the study effort completed in Phase A, focusing on the baseline engine configuration selected. Analysis and trade studies were conducted to further optimize some of the major engine subsystems. These changes resulted in improvements to the baseline engine. Several options were evaluated for consideration by vehicle contractors.

  5. Flight Phase Status Monitor Study. Phase I. Systems Concepts

    DTIC Science & Technology

    1984-07-10

    analysis Title indepindent altitude monitor &.; --. ods j or aircraft alerting I(Report No.) monitor concept and modes study Ir s~tems data ( FAA -RD-73...168) ( FAA -RO-75-861 ( FAA RD--6-2221 Objectives 0 Identify nature of typical 0 Develop operational alert 0 Tabulate current boerting inadvertent terrain...alerting system ’ for system design(Rpr o)concepts system concept concepts (DOT/ FAA /RD-82-26) ( FAA -RD-Ba-68) evaluations ( FAA -RO-81-38 I & 11) Objectives 0

  6. Metabolic syndrome and the early detection of impaired glucose tolerance among professionals living in Beijing, China: a cross sectional study

    PubMed Central

    2013-01-01

    Background The purpose of this study is to investigate the association of metabolic syndrome (MS) and its components with the risk of impaired glucose tolerance (IGT) in high risk urban professionals. The goal is to improve the selection of candidates who would most benefit from an oral glucose tolerance test (OGTT). Methods This is a cross sectional study in which MS was identified by both the definitions proposed by the National Cholesterol Education Program (NCEP) and the International Diabetes Federation (IDF). Results There were 928 eligible subjects in the study, and 23.9% of them failed in OGTT. The odds ratio of IGT was increased 3.16-fold for MS defined by the NCEP criteria and 2.79-fold for the hyperglycemia factor alone. Both MS and hyperglycemia were shown to be acceptable measures to discriminate subjects with IGT from those with normal glucose tolerance (NGT). The clustering of any 1, 2, or ≥3 metabolic components resulted in increased odds ratios for IGT: i.e., 1.71, 2.38 and 5.92, respectively. Even without hyperglycemia in the cluster, an increased odds ratio was still observed. The risk of IGT increased dramatically when the fasting plasma glucose and waist circumference were both at their highest defined level. Conclusions MS and its components are associated with the increased risk of IGT. People with MS, one of its components, especially hyperglycemia and central obesity, or a cluster of its components are strong candidates for an OGTT in order to achieve early cost-effective detection of IGT. PMID:24499585

  7. Potassium Measures and Their Associations with Glucose and Diabetes Risk: The Multi-Ethnic Study of Atherosclerosis (MESA)

    PubMed Central

    Chatterjee, Ranee; Zelnick, Leila; Mukamal, Kenneth J.; Nettleton, Jennifer A.; Kestenbaum, Bryan R.; Siscovick, David S.; Ix, Joachim H.; Tracy, Russell; Hoofnagle, Andrew N.; Svetkey, Laura P.; Edelman, David; de Boer, Ian H.

    2016-01-01

    Background Recent studies have found low-normal potassium (K) to be associated with increased diabetes risk. We sought to verify these associations in a multi-ethnic US cohort; and to determine if these associations extend to US Hispanics and Asian-Americans. Methods We analyzed data from Multi-Ethnic Study of Atherosclerosis (MESA) participants who were free-of-diabetes at baseline. We examined cross-sectional associations between measures of K—serum, dietary, and urine—with fasting glucose and HOMA-IR. We examined longitudinal associations between K and diabetes risk over 8 years. Findings In multivariable models, compared to those with higher serum K (≥4.5mmol/L), those with lower serum K (<4.0mmol/L) had significantly higher fasting glucose [1.3 mg/dL (95%CI 0.2, 2.4), P-value = 0.03]. Incident diabetes developed in 1281 of 5415 at-risk participants. In minimally-adjusted models, we found inverse associations between serum and dietary K and diabetes risk. Compared to those with higher serum K, those with lower serum K had an HR (95% CI) of incident diabetes of 1.23 (1.04, 1.47), P-value = 0.02. However, these associations were attenuated in fully-adjusted models. We found no significant interaction between potassium and ethnicity. Conclusions In this multi-ethnic cohort, we found a significant inverse association between serum K and fasting glucose but no significant association with longer-term diabetes risk. This inverse association between potassium and glucose must be studied further to understand the physiology and its potential impact on chronic health. PMID:27280455

  8. Incretin effect potentiates beta-cell responsivity to glucose as well as to its rate of change: OGTT and matched intravenous study.

    PubMed

    Campioni, Marco; Toffolo, Gianna; Shuster, Lynne T; Service, F John; Rizza, Robert A; Cobelli, Claudio

    2007-01-01

    The aim of this study is to gain greater insight into the mechanism whereby "incretins" (greater insulinemia after oral than intravenous glucose) enhance insulin secretion. To do so, we use a model of C-peptide secretion to reanalyze data from a previously published study in which glycemic profiles observed following glucose ingestion were matched in the same 10 subjects by means of an intravenous glucose infusion. We report that incretins increase insulin secretion by enhancing both the dynamic (to the rate of increase of glucose) and static (to given glucose concentration) response with an increase of 58% for the static (Phi(s) = 16.4 +/- 1.8 vs. 24.6 +/- 2.0 10(-9) min(-1), P = 0.01) and 63% for the dynamic (Phi(d) = 278 +/- 32 vs. 463 +/- 86 10(-9), P = 0.02) indexes. Since increases in the dynamic response to glucose are believed to be due to an increase in the rate of docking, and exocytosis of insulin containing granules and increases in the static response to glucose are believed to be caused by a shift in the sensitivity of the beta-cell to glucose, these results suggest that incretins may modulate more than one step in the beta-cell insulin secretory cascade.

  9. Diauxic Growth of Azotobacter vinelandii on Galactose and Glucose: Regulation of Glucose Transport by Another Hexose.

    PubMed

    Wong, T Y; Pei, H; Bancroft, K; Childers, G W

    1995-02-01

    The growth curve of Azotobacter vinelandii was biphasic when the organism was grown in a medium containing a mixture of galactose and glucose. Galactose was the primary carbon source; glucose was also consumed, but the rate at which it was consumed was lower than the rate at which galactose was consumed during the first phase of growth. Metabolic pathways for both sugars were induced. Cell cultures exhibited a second lag period as galactose was depleted. The length of this lag phase varied from 2 to 10 h depending on the pregrowth history of the cells. The second log growth phase occurred at the expense of the remaining glucose in the medium and was accompanied by induction of the high-maximum rate of metabolism glucose-induced glucose permease and increases in the levels of glucose metabolic enzymes. The second lag phase of diauxie may have been due to the time required for induction of the glucose-induced glucose permease.

  10. 21 CFR 312.85 - Phase 4 studies.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 5 2013-04-01 2013-04-01 false Phase 4 studies. 312.85 Section 312.85 Food and...-debilitating Illnesses § 312.85 Phase 4 studies. Concurrent with marketing approval, FDA may seek agreement from the sponsor to conduct certain postmarketing (phase 4) studies to delineate additional...

  11. 21 CFR 312.85 - Phase 4 studies.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 5 2010-04-01 2010-04-01 false Phase 4 studies. 312.85 Section 312.85 Food and...-debilitating Illnesses § 312.85 Phase 4 studies. Concurrent with marketing approval, FDA may seek agreement from the sponsor to conduct certain postmarketing (phase 4) studies to delineate additional...

  12. 21 CFR 312.85 - Phase 4 studies.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 5 2014-04-01 2014-04-01 false Phase 4 studies. 312.85 Section 312.85 Food and...-debilitating Illnesses § 312.85 Phase 4 studies. Concurrent with marketing approval, FDA may seek agreement from the sponsor to conduct certain postmarketing (phase 4) studies to delineate additional...

  13. 21 CFR 312.85 - Phase 4 studies.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 5 2011-04-01 2011-04-01 false Phase 4 studies. 312.85 Section 312.85 Food and...-debilitating Illnesses § 312.85 Phase 4 studies. Concurrent with marketing approval, FDA may seek agreement from the sponsor to conduct certain postmarketing (phase 4) studies to delineate additional...

  14. 21 CFR 312.85 - Phase 4 studies.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 5 2012-04-01 2012-04-01 false Phase 4 studies. 312.85 Section 312.85 Food and...-debilitating Illnesses § 312.85 Phase 4 studies. Concurrent with marketing approval, FDA may seek agreement from the sponsor to conduct certain postmarketing (phase 4) studies to delineate additional...

  15. Study on glucose photoacoustic signals denoising based on a modified wavelet shift-invariance thresholding method

    NASA Astrophysics Data System (ADS)

    Ren, Zhong; Liu, Guodong

    2016-11-01

    To improve the denoising effect of the glucose photoacoustic signals, a modified wavelet thresholding combined shift-invariance algorithm was used in this paper. In addition, the shift-invariance method was added into the improved algorithm. To verify the feasibility of modified wavelet shift-invariance threshold denoising algorithm, the simulation experiments were performed. Results show that the denoising effect of modified wavelet shift-invariance thresholding algorithm is better than that of others because its signal-to-noise ratio is largest and the root-mean-square error is lest. Finally, the modified wavelet shift-invariance threshold denoising was used to remove the noises of the photoacoustic signals of glucose aqueous solutions.

  16. Studying Three-Phase Supply in School

    ERIC Educational Resources Information Center

    Singhal, Amit Kumar; Arun, P.

    2009-01-01

    The power distributions of nearly all major countries have accepted three-phase distribution as a standard. With increasing power requirements of instrumentation today even a small physics laboratory requires a three-phase supply. While physics students are given an introduction to this in passing, no experimental work is done with three-phase…

  17. Radiocarbon labeled fully deuterated glucose: Preparation, chromatography and preliminary distribution studies

    SciTech Connect

    Gatley, S.J.; Wess, M.M.; Govoni, P.L.; Wagner, A.; Katz, J.J.; Friedman, A.M.

    1985-05-01

    Since carbon-deuterium bonds are harder to break than carbon-hydrogen bonds, substitution of deuterium into organic molecules often leads to alterations in metabolism; e.g. fully deuterated glucose (d/sup 7/-G or deuterioglucose) is a poorer substrate than (protio) glucose for the bacterial enzyme, glucose oxidase. Radiolabeled d/sup 7/-G was therefore prepared to search for a possible isotope effect in its biodistribution in mammals. Green algae grown in deuterium oxide for many generations were exposed to C-14 CO/sub 2/ in the light, and then boiled in 2N-HCl. After rotary evaporation of the HCl the residue was passed through H/sup +/-form and CO/sub 3//sup =/-form Dowex columns in water and then passed through silica gel and activated charcoal in ethanol. The major component of the final neutral fraction, d/sup 7/-G was further purified by HPLC on a Bio-Rad HPX-87P column eluted with water. The behavior of d/sup 7/-G on HPX-87P, on an NH-column (Alltech) and on 2D cellulose TLC, was identical with that of glucose. However, on silica gel TLC d/sup 7/-G ran more slowly (R/sub Glc./ = 0.93); this result was confirmed with authentic d/sup 7/-G. In later work, pure C-11 and C-14 d/sup 7/-G were rapidly and conveniently obtained by HPX-87P chromatography of an invertase-treated extract obtained by boiling algae in 80% EtOH. Preliminary tissue distributions and metabolite analyses suggest slow transport of d/sup 7/-G than G into the brain. Exploitation of deuterium isotope effects could become a useful aspect of radiopharmaceutical design.

  18. Detection of glycemic abnormalities in adolescents with beta thalassemia using continuous glucose monitoring and oral glucose tolerance in adolescents and young adults with β-thalassemia major: Pilot study

    PubMed Central

    Soliman, Ashraf T.; Yasin, Mohamed; El-Awwa, Ahmed; De Sanctis, Vincenzo

    2013-01-01

    Background: Both insulin deficiency and resistance are reported in patients with β-thalassemia major (BTM). The use of continuous blood glucose monitoring (CGM), among the different methods for early detection of glycemic abnormalities, has not been studied thoroughly in these adolescents. Materials and Methods: To assess the oralglucose tolerance (OGT) and 72-h continuous glucose concentration by the continuous glucose monitoring system (CGMS) and calculate homeostatic model assessment (HOMA), and the quantitative insulin sensitivity check index (QUICKI) was conducted in 16 adolescents with BTM who were receiving regular blood transfusions every 2-4 weeks and iron-chelation therapy since early childhood. Results: Sixteen adolescents with BTM (age: 19.75 ± 3 years) were investigated. Using OGTT, (25%) had impaired fasting blood (plasma) glucose concentration (BG) (>5.6 mmol/L). 2-h after the glucose load, one of them had BG = 16.2 mmol/L (diabetic) and two had impaired glucose tolerance (IGT) (BG > 7.8 and <11.1 mmol/L). Monitoring the maximum (postprandial) BG using CGMS,4 adolescents were diagnosed with diabetes (25%) (BG >11.1 mmol/L) and 9 with IGT (56%). HOMA and QUICKI revealed levels <2.6 (1.6 ± 0.8) and >0.33 (0.36 ± 0.03), respectively, ruling out significant insulin resistance in these adolescents. There was a significant negative correlation between the β-cell function (B%) on one hand and the fasting and the 2-h BG (r=−0.6, and − 0.48, P < 0.01, respectively) on the other hand. Neither fasting serum insulin nor c-peptide concentrations were correlated with fasting BG or ferritin levels. The average and maximum blood glucose levels during CGM were significantly correlated with the fasting BG (r = 0.68 and 0.39, respectively, with P < 0.01) and with the BG at 2-hour after oral glucose intake (r = 0.87 and 0.86 respectively, with P < 0.001). Ferritin concentrations were correlated with the fasting BG and the 2-h blood glucose levels in the OGTT (r

  19. GLUT2, glucose sensing and glucose homeostasis.

    PubMed

    Thorens, Bernard

    2015-02-01

    The glucose transporter isoform GLUT2 is expressed in liver, intestine, kidney and pancreatic islet beta cells, as well as in the central nervous system, in neurons, astrocytes and tanycytes. Physiological studies of genetically modified mice have revealed a role for GLUT2 in several regulatory mechanisms. In pancreatic beta cells, GLUT2 is required for glucose-stimulated insulin secretion. In hepatocytes, suppression of GLUT2 expression revealed the existence of an unsuspected glucose output pathway that may depend on a membrane traffic-dependent mechanism. GLUT2 expression is nevertheless required for the physiological control of glucose-sensitive genes, and its inactivation in the liver leads to impaired glucose-stimulated insulin secretion, revealing a liver-beta cell axis, which is likely to be dependent on bile acids controlling beta cell secretion capacity. In the nervous system, GLUT2-dependent glucose sensing controls feeding, thermoregulation and pancreatic islet cell mass and function, as well as sympathetic and parasympathetic activities. Electrophysiological and optogenetic techniques established that Glut2 (also known as Slc2a2)-expressing neurons of the nucleus tractus solitarius can be activated by hypoglycaemia to stimulate glucagon secretion. In humans, inactivating mutations in GLUT2 cause Fanconi-Bickel syndrome, which is characterised by hepatomegaly and kidney disease; defects in insulin secretion are rare in adult patients, but GLUT2 mutations cause transient neonatal diabetes. Genome-wide association studies have reported that GLUT2 variants increase the risks of fasting hyperglycaemia, transition to type 2 diabetes, hypercholesterolaemia and cardiovascular diseases. Individuals with a missense mutation in GLUT2 show preference for sugar-containing foods. We will discuss how studies in mice help interpret the role of GLUT2 in human physiology.

  20. Socioeconomic inequalities in lipid and glucose metabolism in early childhood in a population-based cohort: the ABCD-Study

    PubMed Central

    2012-01-01

    Background Socioeconomic inequalities in cardiovascular disease are pervasive, yet much remains to be understood about how they originate. The objective of this study was to explore the relations of socioeconomic status to lipid and glucose metabolism as indicators of cardiovascular health in 5–6 year olds. Additionally to explore the explanatory role of maternal factors, birth outcome, and child factors. Methods In 1308 5–6 year old ethnic Dutch children from the ABCD cohort study, lipids (cholesterol, LDL, HDL, triglycerides), glucose and C-peptide were measured after an overnight-fast. Results There were no differences in cholesterol, HDL, LDL, and triglycerides between socioeconomic groups, as indicated by maternal education and income adequacy. However, children of low educated mothers had on average a higher glucose (β = 0.15; 95% confidence interval (CI) 0.03 – 0.27), logC-peptide (β = 0.07; 95% CI 0.04 – 0.09), and calculated insulin resistance (HOMA-IR) (β = 0.15; 95% CI 0.08 – 0.22) compared to children of high educated mothers. Only childhood BMI partly explained these differences (models controlled for age, height, and sex). Conclusions The socioeconomic gradient in cardiovascular risk factors seems to emerge in early childhood. In absence of underlying mechanisms these empirical findings are relevant for public health care and further explanatory research. PMID:22852830

  1. Effects of niacin on glucose levels, coronary stenosis progression, and clinical events in subjects with normal baseline glucose levels (<100 mg/dl): a combined analysis of the Familial Atherosclerosis Treatment Study (FATS), HDL-Atherosclerosis Treatment Study (HATS), Armed Forces Regression Study (AFREGS), and Carotid Plaque Composition by MRI during lipid-lowering (CPC) study.

    PubMed

    Phan, Binh An P; Muñoz, Luis; Shadzi, Pey; Isquith, Daniel; Triller, Michael; Brown, B Greg; Zhao, Xue-Qiao

    2013-02-01

    Although the effect of niacin on the glucose levels in subjects with diabetes mellitus has been investigated, niacin's effects on the glucose levels and atherosclerosis in subjects with normal glucose levels have not been well established. We examined the effect of niacin on the glucose levels, coronary stenosis progression using quantitative coronary angiography, and clinical events in 407 subjects who had a baseline glucose level <100 mg/dl and were enrolled in the Familial Atherosclerosis Treatment Study (FATS), HDL-Atherosclerosis Treatment Study (HATS), Armed Forces Regression Study (AFREGS), or Carotid Plaque Composition by MRI during lipid-lowering (CPC) study testing active niacin therapy. Although the fasting glucose levels increased significantly within 3 years in both subjects treated with niacin (from 85.6 ± 9.5 to 95.5 ± 19.7 mg/dl, p <0.001) and without niacin (from 85.2 ± 9.6 to 90 ± 17.9 mg/dl, p = 0.009), those treated with niacin had a significantly larger increase in glucose levels than those not taking niacin (9.88 vs 4.05 mg/dl, p = 0.002). Overall, 29% of subjects developed impaired fasting glucose within 3 years. Incident impaired fasting glucose was significantly more likely to be observed in subjects treated with niacin than in those who were not. However, the frequency of new-onset diabetes mellitus did not differ significantly between the 2 groups (5.6% vs 4.8%, p = 0.5). Niacin-treated subjects compared to untreated subjects had significantly less change in mean coronary stenosis (0.1 ± 0.3% vs 2 ± 12%, p <0.0001) and less major cardiovascular events (8% vs 21%, p = 0.001). In conclusion, the use of niacin for 3 years in subjects with normal baseline glucose levels was associated with an increase in blood glucose levels and the risk of developing impaired fasting glucose, but not diabetes mellitus, and was associated with a significantly reduced incidence of coronary stenosis progression and major cardiovascular events.

  2. Radiation-inactivation studies on brush-border-membrane vesicles. General considerations, and application to the glucose and phosphate carriers.

    PubMed Central

    Béliveau, R; Demeule, M; Ibnoul-Khatib, H; Bergeron, M; Beauregard, G; Potier, M

    1988-01-01

    Radiation-inactivation studies were performed on brush-border-membrane vesicles purified from rat kidney cortex. No alteration of the structural integrity of the vesicles was apparent in electron micrographs of irradiated and unirradiated vesicles. The size distributions of the vesicles were also similar for both populations. The molecular sizes of two-brush-border-membrane enzymes, alkaline phosphatase and 5'-nucleotidase, estimated by the radiation-inactivation technique, were 104800 +/- 3500 and 89,400 +/- 1800 Da respectively. Polyacrylamide-gel-electrophoresis patterns of membrane proteins remained unaltered by the radiation treatment, except in the region of higher-molecular-mass proteins, where destruction of the proteins was visible. The molecular size of two of these proteins was estimated from their mobilities in polyacrylamide gels and was similar to the target size, estimated from densitometric scanning of the gel. Intravesicular volume, estimated by the uptake of D-glucose at equilibrium, was unaffected by irradiation. Uptake of Na+, D-glucose and phosphate were measured in initial-rate conditions to avoid artifacts arising from a decrease in the driving force caused by a modification of membrane permeability. Na+-independent D-glucose and phosphate uptakes were totally unaffected in the dose range used (0-9 Mrad). The Na+-dependent uptake of D-glucose was studied in irradiated vesicles, and the molecular size of the transporter was found to be 288,000 Da. The size of the Na+-dependent phosphate carrier was also estimated, and a value of 234,000 Da was obtained. Images Fig. 1. Fig. 4. PMID:3421923

  3. Intelligent Robotic Systems Study (IRSS), phase 3

    NASA Technical Reports Server (NTRS)

    1991-01-01

    This phase of the Intelligent Robotic Systems Study (IRSS) examines some basic dynamics and control issues for a space manipulator attached to its worksite through a compliant base. One example of this scenario is depicted, which is a simplified, planar representation of the Flight Telerobotic Servicer (FTS) Development Test Flight 2 (DTF-2) experiment. The system consists of 4 major components: (1) dual FTS arms to perform dextrous tasks; (2) the main body to house power and electronics; (3) an Attachment Stabilization and Positioning Subsystem (ASPS) to provide coarse positioning and stabilization of the arms, and (4) the Worksite Attachment Mechanism (WAM) which anchors the system to its worksite, such as a Space Station truss node or Shuttle bay platform. The analysis is limited to the DTF-2 scenario. The goal is to understand the basic interaction dynamics between the arm, the positioner and/or stabilizer, and the worksite. The dynamics and controls simulation model are described. Analysis and simulation results are presented.

  4. Change in fasting plasma glucose and incident type 2 diabetes mellitus: results from a prospective cohort study

    PubMed Central

    Mozaffary, Amirhossein; Asgari, Samaneh; Tohidi, Maryam; Kazempour-Ardebili, Sara; Azizi, Fereidoun; Hadaegh, Farzad

    2016-01-01

    Objective To investigate the association between changes in fasting plasma glucose (FPG) values and incident type 2 diabetes (T2D) in a cohort of the Iranian population. Design Prospective cohort study. Setting This study was conducted within the framework of the Tehran Lipid and Glucose Study (TLGS) to investigate the association between change in FPG between baseline examination (1999–2001) and the second visit (2002–2005) with incident T2D. Participants A total of 3981 non-diabetic participants aged ≥20 years. Outcome measure T2D was defined if the participant was using antidiabetic drugs or if FPG was ≥7 mmol/L or if the 2 h post-challenge plasma glucose (2-hPCG) was ≥11.1 mmol/L. Results During a median follow-up of 6.17 years, after the second examination, 288 new cases of T2D were identified. In a multivariate Cox proportional hazard analysis using age as timescale, we presented a simple model including FPG change (HR 1.19, 95% CI 1.07 to 1.33) and baseline waist circumference (WC) (HR 1.004, 95% CI 1.001 to 1.008) with a discriminative power (C-index) of 72%. Furthermore, we showed that the highest quartile of FPG change enhanced the T2D risk to 1.65 (95% CI 1.2 to 2.27) compared with the lowest quartile (p for trend=0.004).The independent risk of FPG change resisted further adjustment with 2-hPCG change. Adding the 2-hPCG change only slightly increased the discriminative power of the model including FPG change and baseline value of WC (0.73% vs 0.72%). After the study population had been limited to those with normal fasting glucose/normal glucose tolerance, FPG change remained an independent predictor (HR 1.57, 95% CI 1.31 to 1.88). Conclusions Two measurements of FPG obtained about 3 years apart can help to identify populations at risk of incident T2D independently of important traditional risk factors and their changes, including 2-hPCG change. PMID:27217283

  5. D-glucose derived novel gemini surfactants: synthesis and study of their surface properties, interaction with DNA, and cytotoxicity.

    PubMed

    Kumar, Vikash; Chatterjee, Amrita; Kumar, Nupur; Ganguly, Anasuya; Chakraborty, Indranil; Banerjee, Mainak

    2014-10-09

    Four new D-glucose derived m-s-m type gemini surfactants with variable spacer and tail length have been synthesized by a simple and efficient synthetic methodology utilizing the free C-3 hydroxy group of diisopropylidene glucose. The synthetic route to these gemini surfactants with a quaternary ammonium group as polar head group involves a sequence of simple reactions including alkylation, imine formation, quaternization of amine etc. The surface properties of the new geminis were evaluated by surface tension and conductivity measurements. These gemini surfactants showed low cytotoxicity by MTT assay on HeLa cell line. The DNA binding capabilities of these surfactants were determined by agarose gel electrophoresis, fluorescence titration, and DLS experiments. The preliminary studies by agarose gel electrophoresis indicated chain length dependent DNA binding abilities, further supported by ethidium bromide exclusion experiments. Two of the D-glucose derived gemini surfactants showed effective binding with pET-28a plasmid DNA (pDNA) at relatively low N/P ratio (i.e., cationic nitrogen/DNA phosphate molar ratio).

  6. Cerebral metabolic rate for glucose during the first six months of life: an FDG positron emission tomography study.

    PubMed Central

    Kinnala, A.; Suhonen-Polvi, H.; Aärimaa, T.; Kero, P.; Korvenranta, H.; Ruotsalainen, U.; Bergman, J.; Haaparanta, M.; Solin, O.; Nuutila, P.; Wegelius, U.

    1996-01-01

    AIM: To measure the local cerebral metabolic rate for glucose (LCMRGlc) in neonatal brains during maturation using positron emission tomography (PET) and 2-[18F]fluoro-2-deoxy-D-glucose (FDG). METHODS: Twenty infants were studied using PET during the neonatal period. The postconceptional age ranged from 32.7 to 60.3 weeks. All infants had normal neurodevelopment and were normoglycaemic. The development of the infants was carefully evaluated (follow up 12-36 months) clinically, and by using a method based on Gesell Amatruda's developmental diagnosis. LCMRGlc was quantitated using PET derived from FDG kinetics and calculated in the whole brain and for regional brain structures. RESULTS: LCMRGlc for various cortical brain regions and the basal ganglia was low at birth (from 4 to 16 mumol/100 g/minute). In infants 2 months of age and younger LCMRGlc was highest in the sensorimotor cortex, thalamus, and brain stem. By 5 months, LCMRGlc had increased in the frontal, parietal, temporal, occipital and cerebellar cortical regions. In general, the whole brain LCMRGlc correlated with postconceptional age (r = 0.90; P < 0.001). The change in the glucose metabolic pattern observed in the neonatal brain reflects the functional maturation of these brain regions. CONCLUSION: These findings show that LCMRGlc in infants increases with maturation. Accordingly, when LCMRGlc is measured during infancy, the postconceptional age has to be taken into account when interpretating the results. Images Figure 1 PMID:8777676

  7. Vapor-liquid phase separator studies

    NASA Technical Reports Server (NTRS)

    Yuan, S. W. K.; Lee, J. M.; Kim, Y. I.; Hepler, W. A.; Frederking, T. H. K.

    1983-01-01

    Porous plugs serve as both entropy rejection devices and phase separation components separating the vapor phase on the downstream side from liquid Helium 2 upstream. The liquid upstream is the cryo-reservoir fluid needed for equipment cooling by means of Helium 2, i.e Helium-4 below its lambda temperature in near-saturated states. The topics outlined are characteristic lengths, transport equations and plug results.

  8. Glucose metabolism and hyperglycemia.

    PubMed

    Giugliano, Dario; Ceriello, Antonio; Esposito, Katherine

    2008-01-01

    Islet dysfunction and peripheral insulin resistance are both present in type 2 diabetes and are both necessary for the development of hyperglycemia. In both type 1 and type 2 diabetes, large, prospective clinical studies have shown a strong relation between time-averaged mean values of glycemia, measured as glycated hemoglobin (HbA1c), and vascular diabetic complications. These studies are the basis for the American Diabetes Association's current recommended treatment goal that HbA1c should be <7%. The measurement of the HbA1c concentration is considered the gold standard for assessing long-term glycemia; however, it does not reveal any information on the extent or frequency of blood glucose excursions, but provides an overall mean value only. Postprandial hyperglycemia occurs frequently in patients with diabetes receiving active treatment and can occur even when metabolic control is apparently good. Interventional studies indicate that reducing postmeal glucose excursions is as important as controlling fasting plasma glucose in persons with diabetes and impaired glucose tolerance. Evidence exists for a causal relation between postmeal glucose increases and microvascular and macrovascular outcomes; therefore, it is not surprising that treatment with different compounds that have specific effects on postprandial glucose regulation is accompanied by a significant improvement of many pathways supposed to be involved in diabetic complications, including oxidative stress, endothelial dysfunction, inflammation, and nuclear factor-kappaB activation. The goal of therapy should be to achieve glycemic status as near to normal as safely possible in all 3 components of glycemic control: HbA1c, fasting glucose, and postmeal glucose peak.

  9. Conceptual design study for a teleoperator visual system, phase 1

    NASA Technical Reports Server (NTRS)

    Adams, D.; Grant, C.; Johnson, C.; Meirick, R.; Polhemus, C.; Ray, A.; Rittenhouse, D.; Skidmore, R.

    1972-01-01

    Results are reported for work performed during the first phase of the conceptual design study for a teleoperator visual system. This phase consists of four tasks: General requirements, concept development, subsystem requirements and analysis, and concept evaluation.

  10. Gas-phase intramolecular elimination reaction studies of steviol glycosides in positive electrospray and tandem mass spectrometry.

    PubMed

    Upreti, Mani; Clos, John F; Somayajula, Kasi V; Milanowski, Dennis J; Mocek, Ulla; Dubois, Grant E; Prakash, Indra

    2009-01-01

    This paper reports the first study of the gas-phase intramolecular elimination reaction of steviol glycosides in positive electrospray mass spectrometry. The observed glycosylated product ions are proposed to be formed via an intramolecular elimination of sugar units from the parent molecule ion. It was further proven by MS/MS studies and deuterium labeling experiments with one of the steviol glycosides, rebaudioside A. These mass spectrometric results confirmed that the new glycosylated product ions observed are most likely formed by the combination of glucose moieties (Glu) II-IV and Glu I via a gas-phase intramolecular elimination reaction.

  11. [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.

  12. Integrated design of electrical distribution systems: Phase balancing and phase prediction case studies

    NASA Astrophysics Data System (ADS)

    Dilek, Murat

    Distribution system analysis and design has experienced a gradual development over the past three decades. The once loosely assembled and largely ad hoc procedures have been progressing toward being well-organized. The increasing power of computers now allows for managing the large volumes of data and other obstacles inherent to distribution system studies. A variety of sophisticated optimization methods, which were impossible to conduct in the past, have been developed and successfully applied to distribution systems. Among the many procedures that deal with making decisions about the state and better operation of a distribution system, two decision support procedures will be addressed in this study: phase balancing and phase prediction. The former recommends re-phasing of single- and double-phase laterals in a radial distribution system in order to improve circuit loss while also maintaining/improving imbalances at various balance point locations. Phase balancing calculations are based on circuit loss information and current magnitudes that are calculated from a power flow solution. The phase balancing algorithm is designed to handle time-varying loads when evaluating phase moves that will result in improved circuit losses over all load points. Applied to radial distribution systems, the phase prediction algorithm attempts to predict the phases of single- and/or double phase laterals that have no phasing information previously recorded by the electric utility. In such an attempt, it uses available customer data and kW/kVar measurements taken at various locations in the system. It is shown that phase balancing is a special case of phase prediction. Building on the phase balancing and phase prediction design studies, this work introduces the concept of integrated design, an approach for coordinating the effects of various design calculations. Integrated design considers using results of multiple design applications rather than employing a single application for a

  13. Comparative study of Inula Racemosa and Saussurea Lappa on the glucose level in Albino rats.

    PubMed

    Chaturvedi, P; Shukla, S; Tripathi, P; Chaurasia, S; Singh, S K; Tripathi, Y B

    1995-07-01

    Inula racemosa and Saussurea lappa have been used in ayurvedic system for the management of diabetes. The result of this communication concludes that I. racemosa reduces the blood glucose earlier as compared to S. lappa. Maximum response in case of I. racemosa is noted between 2 to 4 hours after drug administration while for S. lappa while for S. lappa, it is 4 to 8 hours. S. lappa can be used as substitute for I. racemosa for the management of diabetes, but it should not be taken for granted that this substitution should be applicable to all other systems, where I. racemosa has been recommended as a drug of choice.

  14. [Study of regional cerebral glucose metabolism, in man, while awake or asleep, by positron emission tomography].

    PubMed

    Franck, G; Salmon, E; Poirrier, R; Sadzot, B; Franco, G

    1987-03-01

    Measurements of regional cerebral glucose uptake by the 18F-fluorodeoxyglucose technique (18FDG) and positron emission tomography (PET) along with polygraph recordings were made serially during relaxed wakefulness and different stages of nocturnal sleep in two right-handed normal volunteers. During stage III-IV sleep, values declined diffusely in both hemispheric regions (-31%), thalamus (-33%), cerebellum (-33%) and brain stem (-25%). During paradoxical sleep regional values increased diffusely compared with slow wave sleep. Compared to wakefulness, regional metabolic values seemed to increase but the results were more variable from one volunteer to the other. These preliminary data indicate important regional alterations in cerebral metabolism between sleep states.

  15. Blood glucose regulation in diabetics. A flatness based nonlinear control simulation study

    NASA Astrophysics Data System (ADS)

    Cocha, Guillermo; Podestá, Melina; Mazzadi, Alejandro; Amorena, Carlos; D'Atellis, Carlos

    2016-04-01

    Flat systems are a generalization of linear systems, but the techniques used for controlling flat systems are much different than many of the existing techniques for linear systems. In this paper we present the flatness-based control of blood glucose regulation in human system. A non-near model, he Bergman Minimal Model, is used o represent he dynamics of blood regulation in humans and because of the flatness property, he system variables can be expressed as functions of he at output and heir time derivatives and a control aw developed.

  16. Glucose and insulin tolerance throughout the menstrual cycle.

    PubMed

    Fioretti, P; Genazzani, A R; Felber, J P; Facchini, V; Onano, A M; Romagnino, S; Facchinetti, F; Piras, G L

    1975-03-01

    On the basis of the behaviour during menstrual cycle of the pituitary hormones plasma levels, the Authors have studied during the different periods of the cycle (follicular, ovulatory and luteal) the effects of OGTT and ITT's on the plasma levels of Glucose, insulin, HGH and Cortisol. Significantly lower levels of IRI, HGH and Cortisol were found in follicular phase compared to ovulatory period and luteal phase except for Cortisol in luteal phase. A slightly higher glucose tolerance was found in follicular phase as well as a reduced hypoglicemia under insulin load. Reduced HGH response to ITT was found in follicular phase as well as a reduced Cortisol response compared to the results observed in ovulatory and luteal phase. These data sustain the concept that hormonal variations occurring in an ovulatory cycle are also capable of modifying the woman's body response to various stimuli such as OGTT and ITT.

  17. Phase equilibria study of pseudobrookite type minerals

    NASA Technical Reports Server (NTRS)

    Friel, J. J.

    1974-01-01

    Pseudobrookite, is found in volcanic rocks, and the mineral armalcolite ((Fe,Mg)Ti2O5) found in the Apollo 11 and subsequent lunar samples seems to be unique to the moon. In plutonic rocks on the earth, ilmenite and rutile were found with what appears to be an equilibrium liquidus texture, while on the moon armalcolite often appears to be the primary liquidus phase among Ti-oxides. This suggests that total pressure may be a factor in the formation of these minerals, and a knowledge of the phase relations in this system yields information about the pressure under which a given magma crystallized.

  18. Improved Accuracy of Continuous Glucose Monitoring Systems in Pediatric Patients with Diabetes Mellitus: Results from Two Studies

    PubMed Central

    2016-01-01

    Abstract Objective: This study was designed to evaluate accuracy, performance, and safety of the Dexcom (San Diego, CA) G4® Platinum continuous glucose monitoring (CGM) system (G4P) compared with the Dexcom G4 Platinum with Software 505 algorithm (SW505) when used as adjunctive management to blood glucose (BG) monitoring over a 7-day period in youth, 2–17 years of age, with diabetes. Research Design and Methods: Youth wore either one or two sensors placed on the abdomen or upper buttocks for 7 days, calibrating the device twice daily with a uniform BG meter. Participants had one in-clinic session on Day 1, 4, or 7, during which fingerstick BG measurements (self-monitoring of blood glucose [SMBG]) were obtained every 30 ± 5 min for comparison with CGM, and in youth 6–17 years of age, reference YSI glucose measurements were obtained from arterialized venous blood collected every 15 ± 5 min for comparison with CGM. The sensor was removed by the participant/family after 7 days. Results: In comparison of 2,922 temporally paired points of CGM with the reference YSI measurement for G4P and 2,262 paired points for SW505, the mean absolute relative difference (MARD) was 17% for G4P versus 10% for SW505 (P < 0.0001). In comparison of 16,318 temporally paired points of CGM with SMBG for G4P and 4,264 paired points for SW505, MARD was 15% for G4P versus 13% for SW505 (P < 0.0001). Similarly, error grid analyses indicated superior performance with SW505 compared with G4P in comparison of CGM with YSI and CGM with SMBG results, with greater percentages of SW505 results falling within error grid Zone A or the combined Zones A plus B. There were no serious adverse events or device-related serious adverse events for either the G4P or the SW505, and there was no sensor breakoff. Conclusions: The updated algorithm offers substantial improvements in accuracy and performance in pediatric patients with diabetes. Use of CGM with improved performance has

  19. Phase structure of a single urban intersection: a simulation study

    NASA Astrophysics Data System (ADS)

    Ebrahim Foulaadvand, M.; Fukui, M.; Belbasi, S.

    2010-07-01

    We study the phase structure of a cellular automata model proposed by Belbasi and Foulaadvand to describe the vehicular traffic flow at the intersection of two perpendicular streets. A set of traffic lights operating in a fixed-time scheme controls the traffic flow. A closed boundary condition is applied to the streets, each of which conducts a unidirectional flow. Streets are single-lane and cars cannot turn upon reaching the intersection. Via extensive Monte Carlo simulations it is shown that the model phase diagram consists of ten phases. The flow characteristics in each phase are investigated and the types of phase transitions between phases are specified.

  20. Extraction of effective parameters of turbid media utilizing the Mueller matrix approach: study of glucose sensing.

    PubMed

    Pham, Thi-Thu-Hien; Lo, Yu-Lung

    2012-09-01

    An analytical technique based on Stokes polarimetry and the Mueller matrix method is proposed for extracting the effective linear birefringence, linear dichroism, circular birefringence, circular dichroism, linear depolarization, and circular depolarization properties of turbid media. In contrast to existing analytical models, the model proposed extracts the effective parameters in a decoupled manner and considers not only the circular dichroism properties of the sample, but also the depolarization properties. The results show that the proposed method enables all of the effective parameters to be measured over the full range. Moreover, it is shown that the extracted value of the depolarization index is unaffected by the order in which the depolarizing Mueller matrix is decomposed during the extraction procedure. Finally, a method is proposed for calibrating the optical rotation angle of a polystyrene microsphere suspension containing dissolved D-glucose (C6H12O6) powder in accordance with the distance between the sample and the detector. The experimental results show that the sensitivity of the resulting D-glucose measurement is equal to approximately 1.73  deg/M.

  1. Microflora Disturbance during Progression of Glucose Intolerance and Effect of Sitagliptin: An Animal Study

    PubMed Central

    2016-01-01

    Background. Emerging evidences have shown a close interplay between obesity, diabetes, and intestinal flora disturbance. Dipeptidyl peptidase-4 inhibitor, exemplified by sitagliptin, is highly efficacious in treating type 2 diabetes (T2DM), yet little is known if sitagliptin exerts beneficial effects on microbiota associated with obesity and T2DM. We evaluated changes of gut microbiota following the induction of obesity and T2DM in a streptozotocin treated high fat/high carbohydrate fed (HF/HC-STZ) rat model and explored the effect of sitagliptin on gut microbiota for HF/HC-STZ rats. Methods. Sitagliptin was administered via oral gavage to diabetic rats. Fecal DNA extraction and 454 pyrosequencing based on analysis of 16S rRNA genes was utilized to determine the overall structure of microbiota in fecal DNA samples. Results. Results showed that, at the level of phylum, there was higher abundance of Firmicutes and Tenericutes and less abundance of Bacteroidetes in obese rats compared to their lean counterparts. At the level of genus, short-chain fatty acid- (SCFA-) producing bacteria, Blautia, Roseburia, and Clostridium, and probiotics Lactobacillus, Bifidobacterium, and so forth were identified significantly different from each other among conditions. Conclusion. Marked shifts of the gut microbiota structure were observed in the rats during development of glucose intolerance. Intestinal flora changed in the process of glucose intolerance, and treatment of sitagliptin moderately corrected the dysbiosis of microbiota in T2DM. PMID:27631013

  2. Study on the measuring distance for blood glucose infrared spectral measuring by Monte Carlo simulation

    NASA Astrophysics Data System (ADS)

    Li, Xiang

    2016-10-01

    Blood glucose monitoring is of great importance for controlling diabetes procedure and preventing the complications. At present, the clinical blood glucose concentration measurement is invasive and could be replaced by noninvasive spectroscopy analytical techniques. Among various parameters of optical fiber probe used in spectrum measuring, the measurement distance is the key one. The Monte Carlo technique is a flexible method for simulating light propagation in tissue. The simulation is based on the random walks that photons make as they travel through tissue, which are chosen by statistically sampling the probability distributions for step size and angular deflection per scattering event. The traditional method for determine the optimal distance between transmitting fiber and detector is using Monte Carlo simulation to find out the point where most photons come out. But there is a problem. In the epidermal layer there is no artery, vein or capillary vessel. Thus, when photons propagate and interactive with tissue in epidermal layer, no information is given to the photons. A new criterion is proposed to determine the optimal distance, which is named effective path length in this paper. The path length of each photons travelling in dermis is recorded when running Monte-Carlo simulation, which is the effective path length defined above. The sum of effective path length of every photon at each point is calculated. The detector should be place on the point which has most effective path length. Then the optimal measuring distance between transmitting fiber and detector is determined.

  3. EPA GAS PHASE CHEMISTRY CHAMBER STUDIES

    EPA Science Inventory

    Gas-phase smog chamber experiments are being performed at EPA in order to evaluate a number of current chemical mechanisms for inclusion in EPA regulatory and research models. The smog chambers are 9000 L in volume and constructed of 2-mil teflon film. One of the chambers is co...

  4. Phase Diagram Studies of ZnS Systems

    DTIC Science & Technology

    1988-09-01

    mechanical, processing of ZnS-base ’alloys’. Knowledge of the phase equilibria of various ZnS-rich systems is essential to achieve our objectives...initial studies of the solid-state phase equilibria in the ZnS-CdS and ZnS-Ga2s3 phase diagrams.

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

    NASA Astrophysics Data System (ADS)

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

    2002-07-01

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

  6. Preparation, characterization and in vitro release study of BSA-loaded double-walled glucose-poly(lactide-co-glycolide) microspheres.

    PubMed

    Ansary, Rezaul H; Rahman, Mokhlesur M; Awang, Mohamed B; Katas, Haliza; Hadi, Hazrina; Mohamed, Farahidah; Doolaanea, Abd Almonem; Kamaruzzaman, Yunus B

    2016-09-01

    The aim of this study was to prepare a model protein, bovine serum albumin (BSA) loaded double-walled microspheres using a fast degrading glucose core, hydroxyl-terminated poly(lactide-co-glycolide) (Glu-PLGA) and a moderate-degrading carboxyl-terminated PLGA polymers to reduce the initial burst release and to eliminate the lag phase from the release profile of PLGA microspheres. The double-walled microspheres were prepared using a modified water-in-oil-in-oil-in-water (w/o/o/w) method and single-polymer microspheres were prepared using a conventional water-in-oil-in-water (w/o/w) emulsion solvent evaporation method. The particle size, morphology, encapsulation efficiency, thermal properties, in vitro drug release and structural integrity of BSA were evaluated in this study. Double-walled microspheres prepared with Glu-PLGA and PLGA polymers with a mass ratio of 1:1 were non-porous, smooth-surfaced, and spherical in shape. A significant reduction of initial burst release was achieved for the double-walled microspheres compared to single-polymer microspheres. In addition, microspheres prepared using Glu-PLGA and PLGA polymers in a mass ratio of 1:1 exhibited continuous BSA release after the small initial burst without any lag phase. It can be concluded that the double-walled microspheres made of Glu-PLGA and PLGA polymers in a mass ratio of 1:1 can be a potential delivery system for pharmaceutical proteins.

  7. A study of the interactive effects of oral contraceptive use and dietary fat intake on blood pressure, cardiovascular reactivity and glucose tolerance in normotensive women.

    PubMed

    Straznicky, N E; Barrington, V E; Branley, P; Louis, W J

    1998-03-01

    The interactive effects of combined oral contraceptive (OC) use and dietary fat intake on cardiovascular hemodynamics and metabolic parameters were investigated in a comparative study of 16 normotensive OC users from Australia and 16 age- and weight-matched nonuser controls. The 6-week study's crossover design allocated women to consume either a high- or low-fat diet for 2-week periods. Analyses were performed at the end of each diet during the luteal phase of the menstrual cycle. Plasma triglyceride levels were significantly higher in OC users than nonusers in both diet groups; however, responses of lipoprotein levels to the 2 diets did not differ between study groups. Total and low-density lipoprotein cholesterol levels decreased by 15% and 17%, respectively, in OC users, and by 14% each in non-OC users on the low-fat, compared to the high-fat, diet. Fasting plasma insulin levels, the insulin production response to administration of glucose, and resting clinic and night-time systolic blood pressures were all significantly reduced on the low-fat diet, but only in nonusers. In OC users, blood pressure responses to noradrenaline and maximal heart rate response to cold were significantly attenuated by the low-fat diet. During the low-fat diet, resting systolic, 24-hour systolic, and diastolic blood pressures and areas under the curve were significantly higher in the OC group. OC users also demonstrated a greater systolic sensitivity to administration of both noradrenaline and angiotensin II, and had a higher plasma renin activity, regardless of diet. Overall, these findings confirm that OCs can cause adverse effects on blood pressure, cardiovascular reactivity, and the insulin production response to glucose administration, and negate some of the beneficial effects of a low-fat diet.

  8. Electrochemical studies of biocatalytic anode of sulfonated graphene/ferritin/glucose oxidase layer-by-layer biocomposite films for mediated electron transfer.

    PubMed

    Inamuddin; Haque, Sufia Ul; Naushad, Mu

    2016-06-01

    In this study, a bioanode was developed by using layer-by-layer (LBL) assembly of sulfonated graphene (SG)/ferritin (Frt)/glucose oxidase (GOx). The SG/Frt biocomposite was used as an electron transfer elevator and mediator, respectively. Glucose oxidase (GOx) from Aspergillus niger was applied as a glucose oxidation biocatalyst. The electrocatalytic oxidation of glucose using GOx modified electrode increases with an increase in the concentration of glucose in the range of 10-50mM. The electrochemical measurements of the electrode was carried out by using cyclic voltammetry (CV) at different scan rates (20-100mVs(-1)) in 30mM of glucose solution prepared in 0.3M potassium ferrocyanide (K4Fe(CN)6) and linear sweep voltammetry (LSV). A saturation current density of 50±2mAcm(-2) at a scan rate of 100mVs(-1) for the oxidation of 30Mm glucose is achieved.

  9. Fabrication of glucose fiber sensor based on immobilized GOD technique for rapid measurement.

    PubMed

    Lin, Ting-Qian; Lu, Yin-Lin; Hsu, Cheng-Chih

    2010-12-20

    The concentration and pH value of the immobilized glucose oxidase (GOD) are critical parameters in a glucose sensor. In this study, we develop a glucose fiber sensor integrated with heterodyne interferometry to measure the phase difference arising from the chemical reaction between glucose and GOD. Our studies show that the response time and resolution of this sensor will be strongly affected by the pH and concentration properties of GOD. In addition, the results show good linearity between the calibration curve for the glucose solution and serum based sample. The response time of this sensor can be shorter than 3 seconds and best resolutions are 0.1 and 0.136 mg/dl for glucose solution and serum based sample, respectively.

  10. Building Enclosure Hygrothermal Performance Study, Phase 1

    SciTech Connect

    Karagiozis, A.N.

    2002-08-08

    The moisture performance of three different classes of wall systems has been investigated in the context of the preliminary hygrothermal analysis of walls in Seattle. The results reported in this phase specifically address the moisture performance of walls designed with loads that have some unintentional water penetration. The results have been developed in a manner to present the relative performance of the walls in the same climate with similar water penetration effects. The analysis was performed with the best available input data. Several limitations should be recognized within the context of this study. Results showed that selection of wooden sheathing boards on interior vapor-tight assemblies does not significantly influence the performance of stucco-clad walls. A larger effect was observed when the interior vapor control is made vapor open. When continuous cavity ventilation is employed, the effect of the selection of the type of sheathing board on the hygrothermal performance of the wall was found to be negligible. When comparing oriented strand board sheathing performance against the performance of exterior grade gypsum, the differences are very significant in terms of the amount of moisture content present in the walls. Moisture content alone does not indicate their respective durability as durability is directly related to the combination of relative humidity and temperature, mechanical, chemical, and biological properties of the substrates. This study did not investigate the durability performance of either sheathing. In terms of interior vapor control, inhabitant behavior must be considered during the wall hygrothermal design stage. If interior relative humidity is maintained below 60%, then a latex primer and paint may perform better than the use of PVA or even a polyethylene sheet. When the interior environment is maintained at a higher relative humidity, then stricter vapor control is needed. Multilayered building paper was experimentally shown to

  11. Association of Urinary Metal Profiles with Altered Glucose Levels and Diabetes Risk: A Population-Based Study in China

    PubMed Central

    Feng, Wei; Cui, Xiuqing; Liu, Bing; Liu, Chuanyao; Xiao, Yang; Lu, Wei; Guo, Huan; He, Meian; Zhang, Xiaomin; Yuan, Jing; Chen, Weihong; Wu, Tangchun

    2015-01-01

    Background Elevated heavy metals and fasting plasma glucose (FPG) levels were both associated with increased risk of cardiovascular diseases. However, studies on the associations of heavy metals and essential elements with altered FPG and diabetes risk were limited or conflicting. The objective of this study was to evaluate the potential associations of heavy metals and essential trace elements with FPG and diabetes risk among general Chinese population. Methods We conducted a cross-sectional study to investigate the associations of urinary concentrations of 23 metals with FPG, impaired fasting glucose (IFG) and diabetes among 2242 community-based Chinese adults in Wuhan. We used the false discovery rate (FDR) method to correct for multiple hypothesis tests. Results After adjusting for potential confounders, urinary aluminum, titanium, cobalt, nickel, copper, zinc, selenium, rubidium, strontium, molybdenum, cadmium, antimony, barium, tungsten and lead were associated with altered FPG, IFG or diabetes risk (all P< 0.05); arsenic was only dose-dependently related to diabetes (P< 0.05). After additional adjustment for multiple testing, titanium, copper, zinc, selenium, rubidium, tungsten and lead were still significantly associated with one or more outcomes (all FDR-adjusted P< 0.05). Conclusions Our results suggest that multiple metals in urine are associated with FPG, IFG or diabetes risk. Because the cross-sectional design precludes inferences about causality, further prospective studies are warranted to validate our findings. PMID:25874871

  12. Compressed-tube pressure cell for optical studies at ocean pressures: Application to glucose mutarotation kinetics

    NASA Astrophysics Data System (ADS)

    Lamelas, F. J.

    2016-12-01

    A self-contained compressed-tube pressure cell is tested to 25 MPa. The cell is very simple to construct and offers stable pressure control with optical access to fluid samples. The physical path length of light through the cell is large enough to measure optical activity. The entire system is relatively small and portable, and it is vibration-free, since a compressor is not used. Operation of the cell is demonstrated by measuring the mutarotation rate of aqueous glucose solutions at 25 °C. A logarithmic plot of the rate constant vs. pressure yields an activation volume for mutarotation of -22 cm3/mol, approximately twice the value measured previously at higher pressures.

  13. Diabetes, plasma glucose and incidence of pancreatic cancer: A prospective study of 0.5 million Chinese adults and a meta-analysis of 22 cohort studies.

    PubMed

    Pang, Yuanjie; Kartsonaki, Christiana; Guo, Yu; Bragg, Fiona; Yang, Ling; Bian, Zheng; Chen, Yiping; Iona, Andri; Millwood, Iona Y; Lv, Jun; Yu, Canqing; Chen, Junshi; Li, Liming; Holmes, Michael V; Chen, Zhengming

    2017-04-15

    Diabetes is associated with an increased risk of pancreatic cancer (PC) in Western populations. Uncertainty remains, however, about the relevance of plasma glucose for PC among people without diabetes and about the associations of diabetes and high blood glucose with PC in China where the increase in diabetes prevalence has been very recent. The prospective China Kadoorie Biobank (CKB) study recruited 512,000 adults aged 30-79 years from 10 diverse areas of China during 2004-2008, recording 595 PC cases during 8 years of follow-up. Cox regression yielded adjusted hazard ratios (HRs) for PC associated with diabetes (previously diagnosed or screen-detected) and, among those without previously diagnosed diabetes, with levels of random plasma glucose (RPG). These were further meta-analysed with 22 published prospective studies. Overall 5.8% of CKB participants had diabetes at baseline. Diabetes was associated with almost twofold increased risk of PC (adjusted HR = 1.87, 95% CI 1.48-2.37), with excess risk higher in those with longer duration since diagnosis (p for trend = 0.01). Among those without previously diagnosed diabetes, each 1 mmol/L higher usual RPG was associated with a HR of 1.12 (1.04-1.21). In meta-analysis of CKB and 22 other studies, previously diagnosed diabetes was associated with a 52% excess risk (1.52, 1.43-1.63). Among those without diabetes, each 1 mmol/L higher blood glucose was associated with a 15% (1.15, 1.09-1.21) excess risk. In Chinese and non-Chinese populations, diabetes and higher blood glucose levels among those without diabetes are associated with an increased risk of PC.

  14. A study of patient experience using a blood glucose meter with an in-built insulin dose calculator.

    PubMed

    Ramtoola, Shenaz; Jude, Edward; Robinson, Anthony; Malik, Iqbal; Rayman, Gerrard; Dang, Cuong; RossMartin, Graham David; Ali, Amar

    2014-07-01

    Accurate calculation and adjustment of insulin doses is integral to maintaining glycemic control in insulin treated patients. Difficulties with insulin dose calculations may lead to poor adherence to blood glucose monitoring and insulin treatment regimes, resulting in poor metabolic control. The main objective of this study was to evaluate ease of use and user preference of a high specification touch screen blood glucose meter, which has an in-built insulin calculator, compared to patients' usual method of testing blood glucose and deciding insulin doses. Patients with diabetes on a multiple daily injection insulin regime used the Test Meter without the insulin calculator and 1 of 3 comparator meters, each for a 7-day period. They then used the Test Meter with the in-built calculator for 10 days. Patients completed an ease of use questionnaire after each 7-day period, a preference questionnaire after the second 7-day period, and a questionnaire comparing the Test Meter with their usual method after the final 10-day period. Of 164 patients who completed the study, 76% stated a preference for the Test Meter as a diabetes management tool compared to their usual method. A small number of patients preferred familiar methods and/or calculating insulin doses themselves. The log book function of meters was important to most patients. The Test Meter system with in-built insulin calculator supports people to better manage their diabetes and increases their confidence. Patients have different needs and preferences which should be acknowledged and supported in a patient centered health service.

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

    PubMed Central

    Lei, Hongxia; Gruetter, Rolf

    2006-01-01

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

  16. Accuracy of Continuous Glucose Monitoring During Three Closed-Loop Home Studies Under Free-Living Conditions

    PubMed Central

    Thabit, Hood; Leelarathna, Lalantha; Wilinska, Malgorzata E.; Elleri, Daniella; Allen, Janet M.; Lubina-Solomon, Alexandra; Walkinshaw, Emma; Stadler, Marietta; Choudhary, Pratik; Mader, Julia K.; Dellweg, Sibylle; Benesch, Carsten; Pieber, Thomas R.; Arnolds, Sabine; Heller, Simon R.; Amiel, Stephanie A.; Dunger, David; Evans, Mark L.

    2015-01-01

    Abstract Objectives: Closed-loop (CL) systems modulate insulin delivery based on glucose levels measured by a continuous glucose monitor (CGM). Accuracy of the CGM affects CL performance and safety. We evaluated the accuracy of the Freestyle Navigator® II CGM (Abbott Diabetes Care, Alameda, CA) during three unsupervised, randomized, open-label, crossover home CL studies. Materials and Methods: Paired CGM and capillary glucose values (10,597 pairs) were collected from 57 participants with type 1 diabetes (41 adults [mean±SD age, 39±12 years; mean±SD hemoglobin A1c, 7.9±0.8%] recruited at five centers and 16 adolescents [mean±SD age, 15.6±3.6 years; mean±SD hemoglobin A1c, 8.1±0.8%] recruited at two centers). Numerical accuracy was assessed by absolute relative difference (ARD) and International Organization for Standardization (ISO) 15197:2013 15/15% limits, and clinical accuracy was assessed by Clarke error grid analysis. Results: Total duration of sensor use was 2,002 days (48,052 h). Overall sensor accuracy for the capillary glucose range (1.1–27.8 mmol/L) showed mean±SD and median (interquartile range) ARD of 14.2±15.5% and 10.0% (4.5%, 18.4%), respectively. Lowest mean ARD was observed in the hyperglycemic range (9.8±8.8%). Over 95% of pairs were in combined Clarke error grid Zones A and B (A, 80.1%, B, 16.2%). Overall, 70.0% of the sensor readings satisfied ISO criteria. Mean ARD was consistent (12.3%; 95% of the values fall within ±3.7%) and not different between participants (P=0.06) within the euglycemic and hyperglycemic range, when CL is actively modulating insulin delivery. Conclusions: Consistent accuracy of the CGM within the euglycemic–hyperglycemic range using the Freestyle Navigator II was observed and supports its use in home CL studies. Our results may contribute toward establishing normative CGM performance criteria for unsupervised home use of CL. PMID:26241693

  17. Lymphoblastoid Cell Lines as a Tool to Study Inter-Individual Differences in the Response to Glucose

    PubMed Central

    Grassi, Michael A.; Rao, Vidhya R.; Chen, Siquan; Cao, Dingcai; Gao, Xiaoyu; Cleary, Patricia A.; Huang, R. Stephanie; Paterson, Andrew D.; Natarajan, Rama; Rehman, Jalees; Kern, Timothy S.

    2016-01-01

    Background White blood cells have been shown in animal studies to play a central role in the pathogenesis of diabetic retinopathy. Lymphoblastoid cells are immortalized EBV-transformed primary B-cell leukocytes that have been extensively used as a model for conditions in which white blood cells play a primary role. The purpose of this study was to investigate whether lymphoblastoid cell lines, by retaining many of the key features of primary leukocytes, can be induced with glucose to demonstrate relevant biological responses to those found in diabetic retinopathy. Methods Lymphoblastoid cell lines were obtained from twenty-three human subjects. Differences between high and standard glucose conditions were assessed for expression, endothelial adhesion, and reactive oxygen species. Results Collectively, stimulation of the lymphoblastoid cell lines with high glucose demonstrated corresponding changes on molecular, cellular and functional levels. Lymphoblastoid cell lines up-regulated expression of a panel of genes associated with the leukocyte-mediated inflammation found in diabetic retinopathy that include: a cytokine (IL-1B fold change = 2.11, p-value = 0.02), an enzyme (PKCB fold change = 2.30, p-value = 0.01), transcription factors (NFKB-p50 fold change = 2.05, p-value = 0.01), (NFKB-p65 fold change = 2.82, p-value = 0.003), and an adhesion molecule (CD18 fold change = 2.59, 0.02). Protein expression of CD18 was also increased (p-value = 2.14x10-5). The lymphoblastoid cell lines demonstrated increased adhesiveness to endothelial cells (p = 1.28x10-5). Reactive oxygen species were increased (p = 2.56x10-6). Significant inter-individual variation among the lymphoblastoid cell lines in these responses was evident (F = 18.70, p < 0.0001). Conclusions Exposure of lymphoblastoid cell lines derived from different human subjects to high glucose demonstrated differential and heterogeneous gene expression, adhesion, and cellular effects that recapitulated features found in

  18. A study of the effect of diet on glycosylated haemoglobin and albumin levels and glucose tolerance in normal subjects.

    PubMed

    Ryle, A J; Davie, S; Gould, B J; Yudkin, J S

    1990-12-01

    As factors other than the degree of glucose tolerance or ambient blood glucose may determine glycosylated haemoglobin levels, we have investigated the effects of dietary glucose and soluble fibre supplementation on glucose tolerance, glycosylated haemoglobin and glycosylated albumin in non-diabetic subjects. Eleven non-diabetic subjects (7 M, 4 F; age 26.5 +/- 6.5 (+/- SD) yr; BMI 21.6 +/- 3.1 kg m-2) followed a high-soluble-fibre (5 g guar gum thrice daily)/low-glucose diet, or a low-soluble-fibre/high-glucose (500 ml glucose drink providing 100 g glucose per day) diet, each for 6 weeks, in randomized order. A 75 g oral glucose tolerance test was performed at recruitment and after each diet period, and fasting blood was assayed for glycosylated albumin by affinity chromatography, and glycosylated haemoglobin by four different methods. Adherence to guar and glucose supplementation was assessed at 89.5 +/- 7.5% and 97.1 +/- 3.5%, respectively. There was no significant effect of either diet on mean fasting, 1-h or 2-h plasma glucose concentration, or glycosylated haemoglobin levels by any assay. Glycosylated albumin was 1.71 +/- 0.35% at entry, fell to 1.33 +/- 0.30% (p less than 0.01) with high-fibre and rose to 1.95 +/- 0.23% (p less than 0.02) after a high-glucose diet. Insulin, total- and HDL-cholesterol and triglyceride levels were unaffected by either diet. A high-glucose diet increases, and a high-soluble-fibre diet decreases, levels of glycosylated albumin without effects on glucose tolerance or glycosylated haemoglobin.

  19. Membrane lipid phase transitions and phase organization studied by Fourier transform infrared spectroscopy.

    PubMed

    Lewis, Ruthven N A H; McElhaney, Ronald N

    2013-10-01

    Fourier transform infrared (FTIR) spectroscopy is a powerful yet relatively inexpensive and convenient technique for studying the structure and organization of membrane lipids in their various polymorphic phases. This spectroscopic technique yields information about the conformation and dynamics of all regions of the lipid molecule simultaneously without the necessity of introducing extrinsic probes. In this review, we summarize some relatively recent FTIR spectroscopic studies of the structure and organization primarily of fully hydrated phospholipids in their biologically relevant lamellar crystalline, gel and liquid-crystalline phases, and show that interconversions between these bilayer phases can be accurately monitored by this technique. We also briefly discuss how the structure and organization of potentially biologically relevant nonlamellar micellar or reversed hexagonal lipid phases can be studied and how phase transitions between lamellar and nonlamellar phases, or between various nonlamellar phases, can be followed as well. In addition, we discuss the potential for FTIR spectroscopy to yield fairly high resolution structural information about phospholipid packing in lamellar crystalline or gel phases. Finally, we show that many, but not all of these FTIR approaches can also yield valuable information about lipid-protein interactions in membrane protein- or peptide-containing lipid membrane bilayer model or even in biological membranes. This article is part of a Special Issue entitled: FTIR in membrane proteins and peptide studies.

  20. A study of the role of glucose transporter 1 (Glut1) in white spot syndrome virus (WSSV) infection.

    PubMed

    Huang, Huai-Ting; Chan, Hoi-Ling; Shih, Tsai-Yen; Chen, Li-Li

    2015-10-01

    White spot syndrome virus (WSSV) is a large enveloped DNA virus, and it causes a serious disease that has led to severe mortalities of cultured shrimps in many countries. To determine the mechanism of virus entry into the cell and to establish an antiviral strategy, the cell receptor for virus entry and receptor binding protein should be identified. A shrimp cell surface protein, glucose transporter1 (Glut1), was found to interact with WSSV in previous study. In this study, this Glut1 was confirmed to have the ability of transporting glucose, and this gene can also be found in other shrimp species. The interaction between Glut1 and some other WSSV envelope proteins in the infectome structure was verified by far western blot and His pull down assay. In vitro and in vivo neutralization using recombinant partial Glut1 revealed that the large extracellular portion of Glut1 could delay WSSV infection. Also, shrimps which were knocked-down Glut1 gene by treated with dsRNA before WSSV challenge showed decreased mortality. These results indeed provide a direction to develop efficient antiviral strategies or therapeutic methods by using Glut1.

  1. Glucose-6-phosphate dehydrogenase deficiency and risk of colorectal cancer in Northern Sardinia: A retrospective observational study.

    PubMed

    Dore, Maria P; Davoli, Agnese; Longo, Nunzio; Marras, Giuseppina; Pes, Giovanni M

    2016-11-01

    Glucose-6-phosphate dehydrogenase (G6PD) deficiency has been associated with a lower cancer risk, possibly via a reduction of mutagenic oxygen-free radicals and by reducing nicotinamide-adeninedinucleotide-phosphate for replicating cells. In Sardinia, the enzyme defect is frequent as a consequence of selection by malaria in the past. This study investigated the relationship between G6PD deficiency and colorectal cancer (CRC).A retrospective case-control study of 3901 patients from Sardinia, who underwent a colonoscopy between 2006 and 2016, was performed. G6PD phenotype was assessed for each subject. The proportion of pre and malignant colorectal lesions was compared in cases (G6PD-deficient) and controls (G6PD-normal). Data concerning age, sex, family history of CRC, smoking habits, body height, and weight, and also associated diseases were collected.The CRC risk reduction was 43.2% among G6PD-deficient compared with G6PD-normal subjects (odds ratio 0.57, 95% confidence interval 0.37-0.87, P = 0.010). Age, sex, family history of CRC, and also comorbidities such as type 1 diabetes and ischemic heart disease, were significantly associated with CRC risk. The protective effect of G6PD deficiency remained significant after adjusting for all covariates by logistic regression analysis, and was consistently lower across all age groups.Glucose-6-phosphate dehydrogenase enzyme deficiency is associated with a reduced risk of CRC.

  2. Endogenous circadian system and circadian misalignment impact glucose tolerance via separate mechanisms in humans

    PubMed Central

    Morris, Christopher J.; Yang, Jessica N.; Garcia, Joanna I.; Myers, Samantha; Bozzi, Isadora; Wang, Wei; Buxton, Orfeu M.; Shea, Steven A.; Scheer, Frank A. J. L.

    2015-01-01

    Glucose tolerance is lower in the evening and at night than in the morning. However, the relative contribution of the circadian system vs. the behavioral cycle (including the sleep/wake and fasting/feeding cycles) is unclear. Furthermore, although shift work is a diabetes risk factor, the separate impact on glucose tolerance of the behavioral cycle, circadian phase, and circadian disruption (i.e., misalignment between the central circadian pacemaker and the behavioral cycle) has not been systematically studied. Here we show—by using two 8-d laboratory protocols—in healthy adults that the circadian system and circadian misalignment have distinct influences on glucose tolerance, both separate from the behavioral cycle. First, postprandial glucose was 17% higher (i.e., lower glucose tolerance) in the biological evening (8:00 PM) than morning (8:00 AM; i.e., a circadian phase effect), independent of the behavioral cycle effect. Second, circadian misalignment itself (12-h behavioral cycle inversion) increased postprandial glucose by 6%. Third, these variations in glucose tolerance appeared to be explained, at least in part, by different mechanisms: during the biological evening by decreased pancreatic β-cell function (27% lower early-phase insulin) and during circadian misalignment presumably by decreased insulin sensitivity (elevated postprandial glucose despite 14% higher late-phase insulin) without change in early-phase insulin. We explored possible contributing factors, including changes in polysomnographic sleep and 24-h hormonal profiles. We demonstrate that the circadian system importantly contributes to the reduced glucose tolerance observed in the evening compared with the morning. Separately, circadian misalignment reduces glucose tolerance, providing a mechanism to help explain the increased diabetes risk in shift workers. PMID:25870289

  3. Endogenous circadian system and circadian misalignment impact glucose tolerance via separate mechanisms in humans.

    PubMed

    Morris, Christopher J; Yang, Jessica N; Garcia, Joanna I; Myers, Samantha; Bozzi, Isadora; Wang, Wei; Buxton, Orfeu M; Shea, Steven A; Scheer, Frank A J L

    2015-04-28

    Glucose tolerance is lower in the evening and at night than in the morning. However, the relative contribution of the circadian system vs. the behavioral cycle (including the sleep/wake and fasting/feeding cycles) is unclear. Furthermore, although shift work is a diabetes risk factor, the separate impact on glucose tolerance of the behavioral cycle, circadian phase, and circadian disruption (i.e., misalignment between the central circadian pacemaker and the behavioral cycle) has not been systematically studied. Here we show--by using two 8-d laboratory protocols--in healthy adults that the circadian system and circadian misalignment have distinct influences on glucose tolerance, both separate from the behavioral cycle. First, postprandial glucose was 17% higher (i.e., lower glucose tolerance) in the biological evening (8:00 PM) than morning (8:00 AM; i.e., a circadian phase effect), independent of the behavioral cycle effect. Second, circadian misalignment itself (12-h behavioral cycle inversion) increased postprandial glucose by 6%. Third, these variations in glucose tolerance appeared to be explained, at least in part, by different mechanisms: during the biological evening by decreased pancreatic β-cell function (27% lower early-phase insulin) and during circadian misalignment presumably by decreased insulin sensitivity (elevated postprandial glucose despite 14% higher late-phase insulin) without change in early-phase insulin. We explored possible contributing factors, including changes in polysomnographic sleep and 24-h hormonal profiles. We demonstrate that the circadian system importantly contributes to the reduced glucose tolerance observed in the evening compared with the morning. Separately, circadian misalignment reduces glucose tolerance, providing a mechanism to help explain the increased diabetes risk in shift workers.

  4. Normal fasting plasma glucose levels and type 2 diabetes: the high-risk and population strategy for occupational health promotion (HIPOP-OHP) [corrected] study.

    PubMed

    Hayashino, Y; Fukuhara, S; Suzukamo, Y; Okamura, T; Tanaka, T; Ueshima, H

    2007-09-01

    The objective of this study is to ascertain if higher normal fasting glucose levels are also an independent risk of developing diabetes in an Asian population, and we thus analysed data from a cohort of healthy Japanese workers. We used data from the non-randomised trial on health promotion intervention, High-risk and Population Strategy for Occupational Health Promotion (HIPOP-OHP) Study. Diabetes cases and those who had fasting blood glucose levels equal to or greater than 100 mg/dl at baseline were excluded, and the Cox proportional-hazards model was used for the analysis. During the four-year follow-up of 2212 participants, we found 37 diabetes cases. In the multivariable model, people with blood glucose levels in the 4th quartile had a higher risk of diabetes than those in the bottom quartile; the multivariable-adjusted odds ratio was 2.52. The risk of diabetes abruptly rose in persons with blood glucose levels higher than 94 mg/dl (fourth quartile). A significant linear trend was not observed in the 1st to 3rd quartiles (p=0.726). In conclusion, higher fasting glucose level was associated with the risk of diabetes, and we found a threshold in the association between fasting blood glucose levels and risk of diabetes in an Asian population.

  5. Mechanistic study of organometallic vapor phase epitaxy

    SciTech Connect

    Stringfellow, G.B.

    1990-12-31

    Only AsH{sub 3} and PH{sub 3} have been used as the group V source molecules for organometallic vapor phase epitaxy (OMVPE) of III/V semiconductors until recently, since they have been the only precursors yielding device quality materials. This paper reviews recent work on the pyrolysis of individual organometallic molecules, with emphasis on the group V sources, including: (1) the methylarsines, di- and tri-methylarsine, (2) the ethylarsines, mono-, di-, and tri-ethylarsine, and (3) the singly substituted tertiarybutyl arsine and phosphine molecules. The pyrolysis and growth reactions occurring when both group III and group V precursors are present simultaneously, i.e., the reactions occuring during OMVPE growth of several III/V semiconductors, are also briefly reviewed.

  6. Mechanistic study of organometallic vapor phase epitaxy

    SciTech Connect

    Stringfellow, G.B.

    1990-01-01

    Only AsH{sub 3} and PH{sub 3} have been used as the group V source molecules for organometallic vapor phase epitaxy (OMVPE) of III/V semiconductors until recently, since they have been the only precursors yielding device quality materials. This paper reviews recent work on the pyrolysis of individual organometallic molecules, with emphasis on the group V sources, including: (1) the methylarsines, di- and tri-methylarsine, (2) the ethylarsines, mono-, di-, and tri-ethylarsine, and (3) the singly substituted tertiarybutyl arsine and phosphine molecules. The pyrolysis and growth reactions occurring when both group III and group V precursors are present simultaneously, i.e., the reactions occuring during OMVPE growth of several III/V semiconductors, are also briefly reviewed.

  7. Modeling multiple experiments using regularized optimization: A case study on bacterial glucose utilization dynamics.

    PubMed

    Hartmann, András; Lemos, João M; Vinga, Susana

    2015-08-01

    The aim of inverse modeling is to capture the systems׳ dynamics through a set of parameterized Ordinary Differential Equations (ODEs). Parameters are often required to fit multiple repeated measurements or different experimental conditions. This typically leads to a multi-objective optimization problem that can be formulated as a non-convex optimization problem. Modeling of glucose utilization of Lactococcus lactis bacteria is considered using in vivo Nuclear Magnetic Resonance (NMR) measurements in perturbation experiments. We propose an ODE model based on a modified time-varying exponential decay that is flexible enough to model several different experimental conditions. The starting point is an over-parameterized non-linear model that will be further simplified through an optimization procedure with regularization penalties. For the parameter estimation, a stochastic global optimization method, particle swarm optimization (PSO) is used. A regularization is introduced to the identification, imposing that parameters should be the same across several experiments in order to identify a general model. On the remaining parameter that varies across the experiments a function is fit in order to be able to predict new experiments for any initial condition. The method is cross-validated by fitting the model to two experiments and validating the third one. Finally, the proposed model is integrated with existing models of glycolysis in order to reconstruct the remaining metabolites. The method was found useful as a general procedure to reduce the number of parameters of unidentifiable and over-parameterized models, thus supporting feature selection methods for parametric models.

  8. Life and death of proteins: a case study of glucose-starved Staphylococcus aureus.

    PubMed

    Michalik, Stephan; Bernhardt, Jörg; Otto, Andreas; Moche, Martin; Becher, Dörte; Meyer, Hanna; Lalk, Michael; Schurmann, Claudia; Schlüter, Rabea; Kock, Holger; Gerth, Ulf; Hecker, Michael

    2012-09-01

    The cellular amount of proteins not only depends on synthesis but also on degradation. Here, we expand the understanding of differential protein levels by complementing synthesis data with a proteome-wide, mass spectrometry-based stable isotope labeling with amino acids in cell culture analysis of protein degradation in the human pathogen Staphylococcus aureus during glucose starvation. Monitoring protein stability profiles in a wild type and an isogenic clpP protease mutant revealed that 1) proteolysis mainly affected proteins with vegetative functions, anabolic and selected catabolic enzymes, whereas the expression of TCA cycle and gluconeogenesis enzymes increased; 2) most proteins were prone to aggregation in the clpP mutant; 3) the absence of ClpP correlated with protein denaturation and oxidative stress responses, deregulation of virulence factors and a CodY repression. We suggest that degradation of redundant, inactive proteins disintegrated from functional complexes and thereby amenable to proteolytic attack is a fundamental cellular process in all organisms to regain nutrients and guarantee protein homeostasis.

  9. Is a family history of diabetes associated with an increased level of cardiovascular risk factors? Studies in healthy people and in subjects with different degree of glucose intolerance.

    PubMed

    Quatraro, A; Giugliano, D; De Rosa, N; Minei, A; Ettorre, M; Donzella, C; Saccomanno, F; Ceriello, A

    1993-01-01

    In order to evaluate whether the presence of a positive family history of diabetes (PFH) may have a negative impact on both glucose metabolism and cardiovascular risk factors, we studied parameters of carbohydrate metabolism (fasting and 2h-plasma glucose, HbA1c) and beta-cell function (fasting insulin and C-peptide), as well as the levels of some established cardiovascular risk factors (total cholesterol and triglycerides, HDL-cholesterol, blood pressure) in 729 subjects who were seen within the frame of a Regional Health Program in Taranto, South Italy. According to the NDDG criteria, 147 men and 235 women had normal glucose tolerance, 54 men and 66 women non-diagnostic OGTT, 65 men and 79 women impaired glucose tolerance, and 45 men and 58 women newly-diagnosed Type 2 diabetes. There was a continuous increase of PFH across the categories of glucose intolerance (p < 0.001). Subjects with PFH were younger (4 years on the average) than subjects without PFH. After adjustment for age, there was no difference in the clinical and metabolic parameters considered across the categories of glucose tolerance between subjects with or without PFH. Only in OGTT-diagnosed diabetics, was the presence of PFH associated with significantly greater levels of total cholesterol and 2h-plasma glucose, as well as a trend for triglycerides and HbA1c to be higher. There was a continuous increase in fasting glucose, HbA1c, insulin and C-peptide across the categories; however, the C-peptide/insulin molar ratio was lowest in OGTT-diagnosed diabetics. There was a graded and significant increase in the levels of cardiovascular risk factors across the categories.(ABSTRACT TRUNCATED AT 250 WORDS)

  10. A cross-over study of the acute effects of espresso coffee on glucose tolerance and insulin sensitivity in people with type 2 diabetes mellitus.

    PubMed

    Krebs, Jeremy D; Parry-Strong, Amber; Weatherall, Mark; Carroll, Richard W; Downie, Michelle

    2012-09-01

    The objective was to determine the effect of a single dose of espresso caffeinated coffee, decaffeinated coffee, or water on glucose tolerance and insulin sensitivity in people with type 2 diabetes mellitus. Eighteen participants who were habitual coffee drinkers, were studied using a random-order cross-over design. After a fasting blood sample participants consumed either a double-shot black espresso coffee, decaffeinated coffee, or hot water. The main outcomes were area under the curve (AUC) glucose and insulin, and insulin sensitivity (Matsuda index) during a 75 g oral glucose tolerance test (OGTT) performed one hour later. Other outcomes were change in glucose and insulin and also the insulinogenic index (IGI) and disposition index (DI). AUC glucose was marginally different between beverages (P=.06) being greater following caffeinated coffee than water, mean difference 104 mmol/L/180 min (95% CI 0.1 to 198.1, P=.031), or decaffeinated coffee, mean difference 92.1 mmol/L/180 min (95% CI -1.9 to 186.1, P=.055). There was no difference in AUC insulin (P=.87) or insulin sensitivity (P=.47), nor in change in glucose or insulin over the hour following beverage consumption. There was a marginal difference in IGI between beverages (P=.097) with coffee having a lower incremental increase in insulin/glucose than water (P=.037) though no difference between coffee and decaffeinated coffee (P=.54) and no difference in DI (P=.23). Black espresso coffee in people with type 2 diabetes mellitus results in a marginally greater excursion of glucose during a following OGTT compared with water or decaffeinated coffee. This effect does not appear to be mediated by changes in insulin sensitivity.

  11. Sodium-glucose cotransport

    PubMed Central

    Poulsen, Søren Brandt; Fenton, Robert A.; Rieg, Timo

    2017-01-01

    Purpose of review Sodium-glucose cotransporters (SGLTs) are important mediators of glucose uptake across apical cell membranes. SGLT1 mediates almost all sodium-dependent glucose uptake in the small intestine, while in the kidney SGLT2, and to a lesser extent SGLT1, account for more than 90% and nearly 3%, respectively, of glucose reabsorption from the glomerular ultrafiltrate. Although the recent availability of SGLT2 inhibitors for the treatment of diabetes mellitus has increased the number of clinical studies, this review has a focus on mechanisms contributing to the cellular regulation of SGLTs. Recent findings Studies have focused on the regulation of SGLT expression under different physiological/pathophysiological conditions, for example diet, age or diabetes mellitus. Several studies provide evidence of SGLT regulation via cyclic adenosine monophosphate/protein kinase A, protein kinase C, glucagon-like peptide 2, insulin, leptin, signal transducer and activator of transcription-3 (STAT3), phosphoinositide-3 kinase (PI3K)/Akt, mitogen-activated protein kinases (MAPKs), nuclear factor-kappaB (NF-kappaB), with-no-K[Lys] kinases/STE20/SPS1-related proline/alanine-rich kinase (Wnk/SPAK) and regulatory solute carrier protein 1 (RS1) pathways. Summary SGLT inhibitors are important drugs for glycemic control in diabetes mellitus. Although the contribution of SGLT1 for absorption of glucose from the intestine as well as SGLT2/SGLT1 for renal glucose reabsorption has been comprehensively defined, this review provides an up-to-date outline for the mechanistic regulation of SGLT1/SGLT2. PMID:26125647

  12. Study of global transcriptional changes of N-GlcNAc2 proteins-producing T24 bladder carcinoma cells under glucose deprivation.

    PubMed

    Isono, Takahiro; Chano, Tokuhiro; Okabe, Hidetoshi; Suzaki, Masafumi

    2013-01-01

    Increased levels of N-linked (β-N- acetylglucosamine)2 [N-GlcNAc2]-modified proteins have been recognized to be an effective response to glucose deprivation. In the first step of this study, using a next generation sequencer, we investigated the global transcriptional changes induced by glucose deprivation in a T24 bladder carcinoma cell line, producing N-GlcNAc2-modified proteins under glucose deprivation. Our transcriptome analysis revealed significant up-regulation of the UDP-GlcNAc biosynthesis pathway and unfolded protein response genes, and down-regulation of G2/M transition-related genes containing mitotic kinases. Our biological analysis confirmed that N-GlcNAc2-modified proteins were localized with BiP proteins in the ER. G2/M arrest was caused by glucose deprivation in T24 cells. Moreover, the knockdown of unfolded protein response genes induced the expressional recovery of mitotic kinases under glucose deprivation. Taken together, our results suggest N-GlcNAc2-modified proteins produced under glucose deprivation caused unfolded protein response in the ER, and that this response induced G2/M arrest.

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

    NASA Astrophysics Data System (ADS)

    Li, Xiang

    2016-10-01

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

  14. Using the first drop of blood for monitoring blood glucose values in critically ill patients: An observational study

    PubMed Central

    Saini, Sunita; Kaur, Sukhpal; Das, Karobi; Saini, Vikas

    2016-01-01

    Context: Using the first drop or second drop of blood while measuring blood glucose (BG) values. Objective: The study was planned to compare the BG values from the first and second drops of blood. Research Settings: The study was conducted at the Main Intensive Care Unit, PGIMER, Chandigarh, India. Research Design: This study was a comparative study. Materials and Methods: Ninety patients aged 2–93 years were enrolled in this study. BG values from the first and second drops of blood were taken and compared. Statistical Analysis Used: Agreement between two drops was assessed using Bland–Altman analysis. A bias of <10 mg/dl was considered clinically acceptable. Linear regression of the mean difference (bias) with the BG readings was performed. Results: One thousand four hundred and seven pairs of BG readings were taken from the enrolled patients. BG values had a bias of 3.9 ± 14.9 mg/dl. Nearly 96.7% of BG readings were within the limits of agreement. The absolute difference between first and second drops of blood was calculated; nearly 75.4% of the readings had fallen between 0 and 10 mg/dl, i.e. clinically acceptable range. Conclusion: There is no compete concordance of values of blood glucose between the first and the second drops of blood; any of the drops can be used for measuring BG values as the difference is not statistically significant. However, if hands are visibly clean and to decrease the blood loss in the critically ill patients where the BG values are measured frequently, using the first drop of blood is advised. PMID:27994381

  15. Assessment of channeling bias among initiators of glucose-lowering drugs: A UK cohort study

    PubMed Central

    Ankarfeldt, Mikkel Z; Thorsted, Brian L; Groenwold, Rolf HH; Adalsteinsson, Erpur; Ali, M Sanni; Klungel, Olaf H

    2017-01-01

    Background Channeling bias may occur when a newly marketed drug and an established drug, despite similar indications, are prescribed to patients with different prognostic characteristics (ie, confounding). Aim To investigate channeling bias and its impact on relative effectiveness of glucagon-like peptide-1 (GLP-1) analogs versus basal insulin and dipeptidyl peptidase-4 inhibitors (DPP-4i) versus sulfonylurea. Methods In the UK Clinical Practice Research Datalink, patients with type 2 diabetes initiating treatment between 2006 and 2015 were included. Analyses were stratified by years since first prescription of GLP-1 and DPP-4i, respectively. The characteristics of GLP-1 versus insulin and DPP-4i versus sulfonylurea initiators were compared over time. After propensity score matching, the relative effectiveness regarding 6-month changes in glycated hemoglobin (HbA1c) and body weight was estimated. Results In total, 8,398 GLP-1, 14,807 insulin, 24,481 DPP-4i, and 33,505 sulfonylurea initiators were identified. No major channeling was observed. Considerable overlap in distributions of characteristics allowed for propensity score-matched analyses. Relative effectiveness was similar across time. The overall relative effect of GLP-1 versus insulin showed no difference for HbA1c and relative increase in body weight (3.57 kg [95% confidence interval {CI}: 3.21, 3.92]) for insulin. The overall relative effect of DPP-4i versus sulfonylurea showed relative decrease in HbA1c (−0.34% [95% CI: −0.38, −0.30]) and increase in body weight (1.58 kg [95% CI: 1.38, 1.78]) for sulfonylurea. Conclusion No major channeling was identified in the investigated glucose-lowering drugs. Relative effectiveness could be estimated already in the first year after launch and was consistent in the years thereafter. PMID:28176886

  16. Overcoming ecologic bias using the two-phase study design.

    PubMed

    Wakefield, Jon; Haneuse, Sebastien J-P A

    2008-04-15

    Ecologic (aggregate) data are widely available and widely utilized in epidemiologic studies. However, ecologic bias, which arises because aggregate data cannot characterize within-group variability in exposure and confounder variables, can only be removed by supplementing ecologic data with individual-level data. Here the authors describe the two-phase study design as a framework for achieving this objective. In phase 1, outcomes are stratified by any combination of area, confounders, and error-prone (or discretized) versions of exposures of interest. Phase 2 data, sampled within each phase 1 stratum, provide accurate measures of exposure and possibly of additional confounders. The phase 1 aggregate-level data provide a high level of statistical power and a cross-classification by which individuals may be efficiently sampled in phase 2. The phase 2 individual-level data then provide a control for ecologic bias by characterizing the within-area variability in exposures and confounders. In this paper, the authors illustrate the two-phase study design by estimating the association between infant mortality and birth weight in several regions of North Carolina for 2000-2004, controlling for gender and race. This example shows that the two-phase design removes ecologic bias and produces gains in efficiency over the use of case-control data alone. The authors discuss the advantages and disadvantages of the approach.

  17. Prevalence of diabetes and impaired fasting glucose in Peru: report from PERUDIAB, a national urban population-based longitudinal study

    PubMed Central

    Seclen, Segundo N; Rosas, Moises E; Arias, Arturo J; Huayta, Ernesto; Medina, Cecilia A

    2015-01-01

    Objectives We aimed to estimate the prevalences of diabetes and impaired fasting glucose (IFG) in a national sample in Peru and assess the relationships with selected sociodemographic variables. Methods We estimated prevalence in PERUDIAB study participants, a nationwide, stratified urban and suburban population selected by random cluster sampling. Between 2010 and 2012, questionnaires were completed and blood tests obtained from 1677 adults ≥25 years of age. Known diabetes was defined as participants having been told so by a doctor or nurse and/or receiving insulin or oral antidiabetic agents. Newly diagnosed diabetes was defined as fasting plasma glucose ≥126 mg/dL determined during the study and without a previous diabetes diagnosis. IFG was defined as fasting plasma glucose of 100–125 mg/dL. Results The estimated national prevalence of diabetes was 7.0% (95% CI 5.3% to 8.7%) and it was 8.4% (95% CI 5.6% to 11.3%) in metropolitan Lima. No gender differences were detected. Known and newly diagnosed diabetes prevalences were estimated as 4.2% and 2.8%, respectively. A logistic regression response surface model showed a complex trend for an increased prevalence of diabetes in middle-aged individuals and in those with no formal education. Diabetes prevalence was higher in coastal (8.2%) than in highlands (4.5%; p=0.03), and jungle (3.5%; p<0.02) regions. The estimated national prevalence of IFG was 22.4%, higher in males than in females (28.3% vs 19.1%; p<0.001), and higher in coastal (26.4%) than in highlands (17.4%; p=0.03), but not jungle regions (14.9%; p=0.07). Conclusions This study confirms diabetes as an important public health problem, especially for middle-aged individuals and those with no formal education. 40% of the affected individuals were undiagnosed. The elevated prevalence of IFG shows that nearly a quarter of the adult population of Peru has an increased risk of diabetes. PMID:26512325

  18. URe{sub 2}-A compressibility study of allotropic phases

    SciTech Connect

    Shukla, B. Shekar, N. V. Chandra Sahu, P. Ch.

    2014-04-24

    URe{sub 2} compound exists in two phases- orthorhombic and hexagonal. The hexagonal phase has been prepared using arc melting and annealingat 500°C for one week, whereas the orthorhombic phase was achieved by annealing the arc melted sample at a temperature 150°C for the same period. High pressure x-ray diffraction studies on these two allotropic forms of URe{sub 2} have been carried out up to ∼15GPa using a diamond anvil cell. Normal compression was observed without any kind of phase transformation; although there is a probability of transformation from the metastable hexagonal to itsstable orthorhombicphase under pressure.

  19. Small modular biopower initiative Phase 1 feasibility studies executive summaries

    SciTech Connect

    Bain, R.

    2000-03-06

    The Phase 1 objective is a feasibility study that includes a market assessment, resource assessment, preliminary system design, and assessment of relevant environmental and safety considerations, and evaluation of financial and cost issues, and a preliminary business plan and commercialization strategy. Each participating company will share at least 20% of the cost of the first phase.

  20. Final Report on Phase II; Study of Academic Library Consortia.

    ERIC Educational Resources Information Center

    Cuadra, Carlos A.; And Others

    Phase II involves a case-study analysis of 15 selected consortia to help determine the usefulness and effectiveness of academic library consortia. The two major products resulting from the project are the "Directory of Academic Library Consortia" and the "Guidelines for the Development of Academic Library Consortia." The Phase II report presents…

  1. Continuous Glucose Monitoring

    PubMed Central

    Fritschi, Cynthia; Quinn, Laurie; Penckofer, Sue; Surdyk, Patricia M.

    2010-01-01

    Purpose The purpose of this descriptive study was to document the experience of wearing a continuous glucose monitoring (CGM) device in women with type 2 diabetes (T2DM). The availability of CGM has provided patients and clinicians with the opportunity to describe the immediate effects of diet, exercise, and medications on blood glucose levels; however, there are few data examining patients’ experiences and acceptability of using CGM. Methods Thirty-five women with T2DM wore a CGM for 3 days. Semistructured interviews were conducted to capture the self-described experience of wearing a CGM. Three open-ended questions were used to guide the participants’ self-reflection. Interviews were transcribed and analyzed. Results The women verbalized both positive and negative aspects of needing to check their blood glucose more frequently and wearing the monitor. After viewing the results, most women were surprised by the magnitude and frequency of blood glucose excursions. They immediately examined their behaviors during the time they wore the CGM. Independent problem-solving skills became apparent as they attempted to identify reasons for hyperglycemia by retracing food intake, physical activity, and stress experiences during the period of CGM. Most important, the majority of women stated they were interested in changing their diabetes-related self-care behaviors, especially eating and exercise behaviors, after reviewing their CGM results. Conclusions CGM is generally acceptable to women with T2DM and offers patients and their health care practitioners a possible alternative to routine glucose monitoring for assessing the effects of real-life events on blood glucose levels. PMID:20016057

  2. Statistical study of generalized nonlinear phase step estimation methods in phase-shifting interferometry

    NASA Astrophysics Data System (ADS)

    Langoju, Rajesh; Patil, Abhijit; Rastogi, Pramod

    2007-11-01

    Signal processing methods based on maximum-likelihood theory, discrete chirp Fourier transform, and spectral estimation methods have enabled accurate measurement of phase in phase-shifting interferometry in the presence of nonlinear response of the piezoelectric transducer to the applied voltage. We present the statistical study of these generalized nonlinear phase step estimation methods to identify the best method by deriving the Cramér-Rao bound. We also address important aspects of these methods for implementation in practical applications and compare the performance of the best-identified method with other bench marking algorithms in the presence of harmonics and noise.

  3. Statistical study of generalized nonlinear phase step estimation methods in phase-shifting interferometry

    SciTech Connect

    Langoju, Rajesh; Patil, Abhijit; Rastogi, Pramod

    2007-11-20

    Signal processing methods based on maximum-likelihood theory, discrete chirp Fourier transform, and spectral estimation methods have enabled accurate measurement of phase in phase-shifting interferometry in the presence of nonlinear response of the piezoelectric transducer to the applied voltage. We present the statistical study of these generalized nonlinear phase step estimation methods to identify the best method by deriving the Cramer-Rao bound. We also address important aspects of these methods for implementation in practical applications and compare the performance of the best-identified method with other bench marking algorithms in the presence of harmonics and noise.

  4. Neuroscience of glucose homeostasis.

    PubMed

    La Fleur, S E; Fliers, E; Kalsbeek, A

    2014-01-01

    Plasma glucose concentrations are homeostatically regulated and maintained within strict boundaries. Several mechanisms are in place to increase glucose output when glucose levels in the circulation drop as a result of glucose utilization, or to decrease glucose output and increase tissue glucose uptake to prevent hyperglycemia. Although the term homeostasis mostly refers to stable levels, the blood glucose concentrations fluctuate over the day/night cycle, with the highest concentrations occurring just prior to the activity period in anticipation of increased caloric need. In this chapter we describe how the brain, particularly the hypothalamus, is involved in both the daily rhythm of plasma glucose concentrations and acute glucose challenges.

  5. Quantitative study of the encapsulation of glucose oxidase into multilamellar vesicles and its effect on enzyme activity

    NASA Astrophysics Data System (ADS)

    Olea, David; Faure, Chrystel

    2003-09-01

    The encapsulation of glucose oxidase (GOx) into onion-type multilamellar vesicles is studied and compared to that of GOx into liposomes. The enzyme was shown not to be affected by encapsulation as evidenced by the complete recovery of its activity after being freed. An ˜15% increase of GOx activity was conferred by confinement in onions in the 30-50 °C temperature range. Entrapment of GOx in onions was proved to be effective since a maximum of 10% leak was measured after 45 days of encapsulation. The encapsulation yield, which reaches 80%, and the number of encapsulated enzyme molecules per onion (1000 GOx molecules) were found to be much higher than for liposomes. The effect of onion composition on the encapsulation yield was determined and predicted by a thermodynamic model applied to the lipids-GOx-phosphate buffer system.

  6. Multi-path transportation futures study: Results from Phase 1

    SciTech Connect

    Patterson, Phil; Singh, Margaret; Plotkin, Steve; Moore, Jim

    2007-03-09

    This PowerPoint briefing provides documentation and details for Phase 1 of the Multi-Path Transportation Futures Study, which compares alternative ways to make significant reductions in oil use and carbon emissions from U.S. light vehicles to 2050. Phase I, completed in 2006, was a scoping study, aimed at identifying key analytic issues and constructing a study design. The Phase 1 analysis included an evaluation of several pathways and scenarios; however, these analyses were limited in number and scope and were designed to be preliminary.

  7. Duke University Campus Planning Study. Phase I.

    ERIC Educational Resources Information Center

    Caudill, Rowlett and Scott, Architects, Houston, TX.

    The goals of this study are to--(1) analyze the educational program and determine the adequacy of the present physical plant to accommodate that program, (2) identify the basic disparities between program and plant, and point out the physical plant inadequacies, (3) develop several alternative solutions for resolving these disparities, and (4)…

  8. Oak Ridge Health Studies phase 1 report, Volume 1: Oak Ridge Phase 1 overview

    SciTech Connect

    Yarbrough, M.I.; Van Cleave, M.L.; Turri, P.; Daniel, J.

    1993-09-01

    In July 1991, the State of Tennessee initiated the Health Studies Agreement with the United States Department of Energy to carry out independent studies of possible adverse health effects in people living in the vicinity of the Oak Ridge Reservation. The health studies focus on those effects that could have resulted or could result from exposures to chemicals and radioactivity released at the Reservation since 1942. The major focus of the first phase was to complete a Dose Reconstruction Feasibility Study. This study was designed to find out if enough data exist about chemical and radionuclide releases from the Oak Ridge Reservation to conduct a second phase. The second phase will lead to estimates of the actual amounts or the ``doses`` of various contaminants received by people as a result of off-site releases. Once the doses of various contaminants have been estimated, scientists and physicians will be better able to evaluate whether adverse health effects could have resulted from the releases.

  9. The effect of short-term metformin treatment on plasma prolactin levels in bromocriptine-treated patients with hyperprolactinaemia and impaired glucose tolerance: a pilot study.

    PubMed

    Krysiak, Robert; Okrzesik, Joanna; Okopien, Boguslaw

    2015-05-01

    Metformin was found to affect plasma levels of some pituitary hormones. This study was aimed at investigating whether metformin treatment has an impact on plasma prolactin levels in bromocriptine-treated patients with hyperprolactinaemia and impaired glucose tolerance. The study included 27 patients with hyperprolactinaemia, who had been treated for at least 6 months with bromocriptine. Based on prolactin levels, bromocriptine-treated patients were divided into two groups: patients with elevated (group A, n = 12) and patients with normal (group B, n = 15) prolactin levels. The control group included 16 age-, sex- and weight-matched hyperprolactinaemia-free individuals with impaired glucose tolerance (group C).The lipid profile, fasting plasma glucose levels, the homeostatic model assessment of insulin resistance ratio (HOMA-IR), glycated haemoglobin, as well as plasma levels of prolactin, thyrotropin and insulin-like growth factor-1 (IGF-1) were assessed at baseline and after 4 months of metformin treatment (2.55-3 g daily). In all treatment groups, metformin reduced HOMA-IR, plasma triglycerides and 2-h postchallenge plasma glucose. In patients with hyperprolactinaemia, but not in the other groups of patients, metformin slightly reduced plasma levels of prolactin, and this effect correlated weakly with the metabolic effects of this drug. Our study shows that metformin decreases plasma prolactin levels only in patients with elevated levels of this hormone. The obtained results suggest that metformin treatment may bring some benefits to hyperprolactinaemic patients with coexisting glucose metabolism disturbances already receiving dopamine agonist therapy.

  10. Predictive Value of Triglyceride Glucose Index for the Risk of Incident Diabetes: A 4-Year Retrospective Longitudinal Study.

    PubMed

    Lee, Da Young; Lee, Eun Seo; Kim, Ji Hyun; Park, Se Eun; Park, Cheol-Young; Oh, Ki-Won; Park, Sung-Woo; Rhee, Eun-Jung; Lee, Won-Young

    The Triglyceride Glucose Index (TyG index) is considered a surrogate marker of insulin resistance. The aim of this study is to investigate whether the TyG index has a predictive role in identifying individuals with a high risk of incident diabetes and to compare it with other indicators of metabolic health. A total 2900 non-diabetic adults who attended five consecutive annual health check-ups at Kangbuk Samsung Hospital was divided into four subgroups using three methods: (1) baseline TyG index; (2) obesity status (body mass index ≥25 kg/m2) and cutoff value of TyG index; (3) obesity status and metabolic health, defined as having fewer than two of the five components of high blood pressure, fasting blood glucose, triglyceride, low high-density lipoprotein cholesterol, and highest decile of homeostasis model assessment-insulin resistance. The development of diabetes was assessed annually using self-questionnaire, fasting glucose, and glycated hemoglobin. We compared the risk of incident diabetes using multivariate Cox analysis. During 11623 person-years there were 101 case of incident diabetes. Subjects with high TyG index had a high risk of diabetes. For TyG index quartiles, hazard ratios (HRs) of quartiles 3 and 4 were 4.06 (p = 0.033) and 5.65 (p = 0.006) respectively. When the subjects were divided by obesity status and cutoff value of TyG index of 8.8, the subgroups with TyG index ≥ 8.8 regardless of obesity had a significantly high risk for diabetes (HR 2.40 [p = 0.024] and 2.25 [p = 0.048]). For obesity status and metabolic health, the two metabolically unhealthy subgroups regardless of obesity had a significantly high risk for diabetes (HRs 2.54 [p = 0.024] and 2.73 [p = 0.021]). In conclusion, the TyG index measured at a single time point may be an indicator of the risk for incident diabetes. The predictive value of the TyG index was comparable to that of metabolic health.

  11. Laser Studies of Gas Phase Radical Reaction.

    DTIC Science & Technology

    1985-11-30

    1nai Irvest-aator Or.G. Hancock gn; FILE CO, Contr3ctor : Oxford University . Physical Chemistry Laboratory. South Parks Road.AD-A 193 689 Oxfor o~d...HIF spectrum and study of reaction of this and the CCI radical with atoms vi) sea;rchtrr; f(r FC) ’ndlict of the 0 *CF, reaction. OXFORD UNIVERSITY -. - SOUTH...0 Awtilability Codes I Avail ’and/or Dis Spcal0 Spoo OXFORD UNIVERSITY Tt SOUTH PARKS ROAD OXFCRD OXFORD � X3Z U.S. Army Contract DAJA45-85-C-0034

  12. Advanced supersonic propulsion study, phase 4

    NASA Technical Reports Server (NTRS)

    Howlett, R. A.

    1977-01-01

    Installation characteristics for a Variable Stream Control Engine (VSCE) were studied for three advanced supersonic airplane designs. Sensitivity of the VSCE concept to change in technology projections was evaluated in terms of impact on overall installed performance. Based on these sensitivity results, critical technology requirements were reviewed, resulting in the reaffirmation of the following requirements: low-noise nozzle system; a high performance, low emissions duct burner and main burner; hot section technology; variable geometry components; and propulsion integration features, including an integrated electronic control system.

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

    NASA Astrophysics Data System (ADS)

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

    2012-03-01

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

  14. In Vitro Study on Glucose Utilization Capacity of Bioactive Fractions of Houttuynia cordata in Isolated Rat Hemidiaphragm and Its Major Phytoconstituent.

    PubMed

    Kumar, Manish; Prasad, Satyendra K; Hemalatha, Siva

    2016-01-01

    Objective. The whole plant of Houttuynia cordata has been reported to have potent antihyperglycemic activity. Therefore, the present study was undertaken to investigate the glucose utilization capacity of bioactive fractions of ethanol extract of Houttuynia cordata (HC) in isolated rat hemidiaphragm. Methods. All the fractions, that is, aqueous (AQ), hexane (HEX), chloroform (CHL), and ethyl acetate (EA), obtained from ethanol extract of H. cordata were subjected to phytochemical standardization use in quercetin as a marker with the help of HPTLC. Further, glucose utilization capacity by rat hemidiaphragm was evaluated in 12 different sets of in vitro experiments. In the study, different fractions from H. cordata as mentioned above were evaluated, where insulin was used as standard and quercetin as a biological standard. Results. Among all the tested fractions, AQ and EA significantly increased glucose uptake by isolated rat hemidiaphragm compared to negative control. Moreover, AQ fractions enhanced the uptake of glucose significantly (p < 0.05) and was found to be more effective than insulin. Conclusions. The augmentation in glucose uptake by hemidiaphragm in presence of AQ and EA fractions may be attributed to the presence of quercetin, which was found to be 7.1 and 3.2% w/w, respectively, in both the fractions.

  15. External fuel vaporization study, phase 1

    NASA Technical Reports Server (NTRS)

    Szetela, E. J.; Chiappetta, L.

    1980-01-01

    A conceptual design study was conducted to devise and evaluate techniques for the external vaporization of fuel for use in an aircraft gas turbine with characteristics similar to the Energy Efficient Engine (E(3)). Three vaporizer concepts were selected and they were analyzed from the standpoint of fuel thermal stability, integration of the vaporizer system into the aircraft engine, engine and vaporizer dynamic response, startup and altitude restart, engine performance, control requirements, safety, and maintenance. One of the concepts was found to improve the performance of the baseline E(3) engine without seriously compromising engine startup and power change response. Increased maintenance is required because of the need for frequent pyrolytic cleaning of the surfaces in contact with hot fuel.

  16. Space transfer vehicle concepts and requirements study, phase 2

    NASA Technical Reports Server (NTRS)

    Cannon, Jeffrey H.; Vinopal, Tim; Andrews, Dana; Richards, Bill; Weber, Gary; Paddock, Greg; Maricich, Peter; Bouton, Bruce; Hagen, Jim; Kolesar, Richard

    1992-01-01

    This final report is a compilation of the Phase 1 and Phase 2 study findings and is intended as a Space Transfer Vehicle (STV) 'users guide' rather than an exhaustive explanation of STV design details. It provides a database for design choices in the general areas of basing, reusability, propulsion, and staging; with selection criteria based on cost, performance, available infrastructure, risk, and technology. The report is organized into the following three parts: (1) design guide; (2) STV Phase 1 Concepts and Requirements Study Summary; and (3) STV Phase 2 Concepts and Requirements Study Summary. The overall objectives of the STV study were to: (1) define preferred STV concepts capable of accommodating future exploration missions in a cost-effective manner; (2) determine the level of technology development required to perform these missions in the most cost effective manner; and (3) develop a decision database of programmatic approaches for the development of an STV concept.

  17. Western Wind and Solar Integration Study Phase 2 (Fact Sheet)

    SciTech Connect

    Not Available

    2013-09-01

    This is one-page, two-sided fact sheet presents high-level summary results of the Western Wind and Solar Integration Study Phase 2, which examined operational impacts of high penetrations of variable renewable generation in the West.

  18. Phase A design study of microgravity fluoride fiber puller

    NASA Technical Reports Server (NTRS)

    Workman, Gary L.; Smith, Guy A.; Kosten, Susan

    1994-01-01

    Improved transmission properties for fluoride fibers due to space processing has great potential for commercial benefits. Phase A design study will determine conceptual feasibility and provide initial definition of the technical requirements and design issues for space.

  19. Western Wind and Solar Integration Study: Phase 2 (Presentation)

    SciTech Connect

    Lew, D.; Brinkman, G.; Ibanez, E.; Lefton, S.; Kumar, N.; Venkataraman, S.; Jordan, G.

    2013-09-01

    This presentation summarizes the scope and results of the Western Wind and Solar Integration Study Phase 2, which examined operational impacts of high penetrations of variable renewable generation in the West.

  20. External fuel vaporization study, phase 2

    NASA Technical Reports Server (NTRS)

    Szetela, E. J.; Chiappetta, L.

    1981-01-01

    An analytical study was conducted to evaluate the effect of variations in fuel properties on the design of an external fuel vaporizaton system. The fuel properties that were considered included thermal stability, critical temperature, enthalpy a critical conditions, volatility, and viscosity. The design parameters that were evaluated included vaporizer weight and the impact on engine requirement such as maintenance, transient response, performance, and altitude relight. The baseline fuel properties were those of Jet A. The variation in thermal stability was taken as the thermal stability variation for Experimental Referee Broad Specification (ERBS) fuel. The results of the analysis indicate that a change in thermal stability equivalent to that of ERBS would increase the vaporization system weight by 20 percent, decrease oprating time between cleaning by 40 percent and make altitude relight more difficult. An increase in fuel critical temperature of 39 K would require a 40 percent increase in vaporization system weight. The assumed increase in enthalpy and volatility would also increase vaporizer weight by 40 percent and make altitude relight extremely difficult. The variation in fuel viscosity would have a negligible effect on the design parameters.

  1. Time Dependent Studies of Reactive Shocks in the Gas Phase

    DTIC Science & Technology

    1978-11-16

    1 LEVEL NRL Memorandum Report 3W tO Time Dependent Studies of Reactive Shocks in the Gas Phase E.S. ORAN, ’T.R. YOUNG and J.P. BORIS Laboratory for...34-• TIME DEPENDENT STUDIES OF REACTIVE SHOCKS IN THE GAS PHASE I. Introduction This paper presents results obtained from a detailed numerical...chemical kinetics, reaction products, and intermediates produced in reactive gas mixtures ignited by the propagation of a shock front. The model is based

  2. Intelligent Robotic Systems Study (IRSS), phase 2

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Under the Intelligent Robotics System Study (IRSS) contract, a generalized robotic control architecture was developed for use with the ProtoFlight Manipulator Arm (PFMA). The controller built for the PFMA provides localized position based force control, teleoperation and advanced path recording and playback capabilities. Various hand controllers can be used with the system in conjunction with a synthetic time delay capability to provide a realistic test bed for typical satellite servicing tasks. The configuration of the IRSS system is illustrated and discussed. The PFMA has six computer controllable degrees of freedom (DOF) plus a seventh manually indexable DOF, making the manipulator a pseudo 7 DOF mechanism. Because the PFMA was not developed to operate in a gravity field, but rather in space, it is counter balanced at the shoulder, elbow and wrist and a spring counterbalance has been added near the wrist to provide additional support. Built with long slender intra-joint linkages, the PFMA has a workspace nearly 2 meters deep and possesses sufficient dexterity to perform numerous satellite servicing tasks. The manipulator is arranged in a shoulder-yaw, pitch, elbow-pitch, and wrist-pitch, yaw, roll configuration, with an indexable shoulder roll joint. Digital control of the PFMA is implemented using a variety of single board computers developed by Heurikon Corporation and other manufacturers. The IRSS controller is designed to be a multi-rate, multi-tasking system. Independent joint servos run at a 134 Hz rate and position based impedance control functions at 67 Hz. Autonomous path generation and hand controller inputs are processed at a 33 Hz.

  3. Dynamic Particle Growth Testing - Phase I Studies

    SciTech Connect

    Hu, M.Z-C.

    2001-05-17

    , particle growth in the bulk would still affect scale formation by consuming a portion of the scale-forming precursor materials. In either case, solid-particle-formation data must be obtained to understand the problem. Previous and ongoing testing based on the measurement of [Al] and [Si] consumption kinetics have indicated that the format of aluminosilicate may be rapid under evaporator conditions. However, the kinetics of particle formation (both in bulk solution and on surfaces) has not been studied. Conditions that cause extremely rapid particle formation are of particular interest, because in that case the solids-formation reactions in the evaporator would be sensitively dependent on process conditions such as chemical composition, temperature, fluid flow, and heat transfer.

  4. Effects of the Non-Nutritive Sweeteners on Glucose Metabolism and Appetite Regulating Hormones: Systematic Review of Observational Prospective Studies and Clinical Trials

    PubMed Central

    Romo-Romo, Alonso; Aguilar-Salinas, Carlos A.; Brito-Córdova, Griselda X.; Gómez Díaz, Rita A.; Vilchis Valentín, David

    2016-01-01

    Background The effects of non-nutritive sweeteners (NNS) on glucose metabolism and appetite regulating hormones are not clear. There is an ongoing debate concerning NNS use and deleterious changes in metabolism. Objectives The aim of this review is to analyze the scientific available evidence regarding the effects of NNS on glucose metabolism and appetite regulating hormones. Data Sources and Study Eligibility Criteria We identified human observational studies evaluating the relation between NNS consumption and obesity, diabetes, and metabolic syndrome, in addition to clinical trials evaluating the effects of NNS in glucose metabolism and appetite regulating hormones. Results Fourteen observational studies evaluating the association between NNS consumption and the development of metabolic diseases and twenty-eight clinical trials studying the effects of NNS on metabolism were included. Finally, two meta-analyses evaluating the association between the consumption of NNS-containing beverages and the development of type 2 diabetes were identified. Conclusions Some observational studies suggest an association between NNS consumption and development of metabolic diseases; however, adiposity is a confounder frequently found in observational studies. The effects of the NNS on glucose metabolism are not clear. The results of the identified clinical trials are contradictory and are not comparable because of the major existing differences between them. Studies evaluating specific NNS, with an adequate sample size, including a homogeneous study group, identifying significant comorbidities, with an appropriate control group, with an appropriate exposure time, and considering adjustment for confounder variables such as adiposity are needed. PMID:27537496

  5. Experimental study on apoptosis of TNFR1 receptor pro-endothelial progenitor cells activated by high glucose induced oxidative stress

    PubMed Central

    Liu, Yong; Xei, Fei; Xu, Xiong-Fei; Zeng, Hong; He, Hu-Qiang; Zhang, Lei; Zheng, Ying-Qiang; He, Yan-Zheng

    2015-01-01

    Objective: To investigate whether high glucose in vitro activating TNFR1 and further promote rat marrow endothelial progenitor cells (EPCs) apoptosis. Methods: Rat morrow endothelial progenitor cells were cultured and identified by Confocal Microscopy; then were treated with high glucose (5.5, 15, 30, 60 mmol/L), mannitol (15, 30, 60, 90 mmol/L), high glucose + Tempol and high glucose+ MAB430. Apoptosis rate of the above cells were detected by flow cytometry. ROS and MDA level and anti-O2- were detected by colorimetric technique; the expression level of TNFR1 induced signal pathway related proteins were detected by Western blotting. Results: High glucose can induce endothelial progenitor cells apoptosis, which is mostly in the later stage (72 h-96 h) instead of the earlier stage (24 h-48 h); high glucose can also induce oxidative stress reaction and the produces ROS and MDA increase significantly in the later stage (after 72 h), but anti-O2- decrease significantly. TNF apoptosis signal pathway related protein expression level not increase in the earlier stage (before 24 h) but increase significantly in the later stage (after 72 h). Tempol and MAB430 down-regulate TNF apoptosis signal pathway related protein expression and reduce EPCs apoptosis. Conclusion: High glucose activates the TNFR1 of TPCs through oxidative stress reaction and further induces cell apoptosis. PMID:26884909

  6. Whole Grain Products, Fish and Bilberries Alter Glucose and Lipid Metabolism in a Randomized, Controlled Trial: The Sysdimet Study

    PubMed Central

    Lankinen, Maria; Schwab, Ursula; Kolehmainen, Marjukka; Paananen, Jussi; Poutanen, Kaisa; Mykkänen, Hannu; Seppänen-Laakso, Tuulikki; Gylling, Helena; Uusitupa, Matti; Orešič, Matej

    2011-01-01

    Background Due to the growing prevalence of type 2 diabetes, new dietary solutions are needed to help improve glucose and lipid metabolism in persons at high risk of developing the disease. Herein we investigated the effects of low-insulin-response grain products, fatty fish, and berries on glucose metabolism and plasma lipidomic profiles in persons with impaired glucose metabolism. Methodology/Principal Findings Altogether 106 men and women with impaired glucose metabolism and with at least two other features of the metabolic syndrome were included in a 12-week parallel dietary intervention. The participants were randomized into three diet intervention groups: (1) whole grain and low postprandial insulin response grain products, fatty fish three times a week, and bilberries three portions per day (HealthyDiet group), (2) Whole grain enriched diet (WGED) group, which includes principally the same grain products as group (1), but with no change in fish or berry consumption, and (3) refined wheat breads (Control). Oral glucose tolerance, plasma fatty acids and lipidomic profiles were measured before and after the intervention. Self-reported compliance with the diets was good and the body weight remained constant. Within the HealthyDiet group two hour glucose concentration and area-under-the-curve for glucose decreased and plasma proportion of (n-3) long-chain PUFAs increased (False Discovery Rate p-values <0.05). Increases in eicosapentaenoic acid and docosahexaenoic acid associated curvilinearly with the improved insulin secretion and glucose disposal. Among the 364 characterized lipids, 25 changed significantly in the HealthyDiet group, including multiple triglycerides incorporating the long chain (n-3) PUFA. Conclusions/Significance The results suggest that the diet rich in whole grain and low insulin response grain products, bilberries, and fatty fish improve glucose metabolism and alter the lipidomic profile. Therefore, such a diet may have a beneficial effect

  7. Kinetic studies on enzyme-catalyzed reactions: oxidation of glucose, decomposition of hydrogen peroxide and their combination.

    PubMed

    Tao, Zhimin; Raffel, Ryan A; Souid, Abdul-Kader; Goodisman, Jerry

    2009-04-08

    The kinetics of the glucose oxidase-catalyzed reaction of glucose with O2, which produces gluconic acid and hydrogen peroxide, and the catalase-assisted breakdown of hydrogen peroxide to generate oxygen, have been measured via the rate of O2 depletion or production. The O2 concentrations in air-saturated phosphate-buffered salt solutions were monitored by measuring the decay of phosphorescence from a Pd phosphor in solution; the decay rate was obtained by fitting the tail of the phosphorescence intensity profile to an exponential. For glucose oxidation in the presence of glucose oxidase, the rate constant determined for the rate-limiting step was k = (3.0 +/- 0.7) x 10(4) M(-1) s(-1) at 37 degrees C. For catalase-catalyzed H2O2 breakdown, the reaction order in [H2O2] was somewhat greater than unity at 37 degrees C and well above unity at 25 degrees C, suggesting different temperature dependences of the rate constants for various steps in the reaction. The two reactions were combined in a single experiment: addition of glucose oxidase to glucose-rich cell-free media caused a rapid drop in [O2], and subsequent addition of catalase caused [O2] to rise and then decrease to zero. The best fit of [O2] to a kinetic model is obtained with the rate constants for glucose oxidation and peroxide decomposition equal to 0.116 s(-1) and 0.090 s(-1) respectively. Cellular respiration in the presence of glucose was found to be three times as rapid as that in glucose-deprived cells. Added NaCN inhibited O2 consumption completely, confirming that oxidation occurred in the cellular mitochondrial respiratory chain.

  8. Changes of Brain Glucose Metabolism in the Pretreatment Patients with Non-Small Cell Lung Cancer: A Retrospective PET/CT Study

    PubMed Central

    Zhang, Weishan; Ning, Ning; Li, Xianjun; Niu, Gang; Bai, Lijun; Guo, Youmin; Yang, Jian

    2016-01-01

    Objective The tumor-to-brain communication has been emphasized by recent converging evidences. This study aimed to compare the difference of brain glucose metabolism between patients with non-small cell lung cancer (NSCLC) and control subjects. Methods NSCLC patients prior to oncotherapy and control subjects without malignancy confirmed by 6 months follow-up were collected and underwent the resting state 18F-fluoro-D-glucose (FDG) PET/CT. Normalized FDG metabolism was calculated by a signal intensity ratio of each brain region to whole brain. Brain glucose metabolism was compared between NSCLC patients and control group using two samples t-test and multivariate test by statistical parametric maps (SPM) software. Results Compared with the control subjects (n = 76), both brain glucose hyper- and hypometabolism regions with significant statistical differences (P<0.01) were found in the NSCLC patients (n = 83). The hypermetabolism regions (bilateral insula, putamen, pallidum, thalamus, hippocampus and amygdala, the right side of cerebellum, orbital part of right inferior frontal gyrus and vermis) were component parts of visceral to brain signal transduction pathways, and the hypometabolism regions (the left superior parietal lobule, bilateral inferior parietal lobule and left fusiform gyrus) lied in dorsal attention network and visuospatial function areas. Conclusions The changes of brain glucose metabolism exist in NSCLC patients prior to oncotherapy, which might be attributed to lung-cancer related visceral sympathetic activation and decrease of dorsal attention network function. PMID:27529342

  9. Study on the postprandial blood glucose suppression effect of D-psicose in borderline diabetes and the safety of long-term ingestion by normal human subjects.

    PubMed

    Hayashi, Noriko; Iida, Tetsuo; Yamada, Takako; Okuma, Kazuhiro; Takehara, Isao; Yamamoto, Takashi; Yamada, Koji; Tokuda, Masaaki

    2010-01-01

    This clinical study was conducted to investigate the safety and effect of D-psicose on postprandial blood glucose levels in adult men and women, including borderline diabetes patients. A randomized double-blind placebo-controlled crossover experiment of single ingestion was conducted on 26 subjects who consumed zero or 5 g of D-psicose in tea with a standard meal. The blood glucose levels at fasting and 30, 60, 90, and 120 min after the meal were compared. The blood glucose level was significantly lower 30 and 60 min after the meal with D-psicose (p<0.01, p<0.05), and a significant decrease was also shown in the area under the curve (p<0.01). The results suggest that D-psicose had an effect to suppress the postprandial blood glucose elevation mainly in borderline diabetes cases. A randomized double-blind placebo-controlled parallel-group experiment of long-term ingestion was conducted on 17 normal subjects who took 5 g of D-psicose or D-glucose with meals three times a day for 12 continuous weeks. Neither any abnormal effects nor clinical problems caused by the continuous ingestion of D-psicose were found.

  10. Quantitative analysis of drug effects at the whole-body level: a case study for glucose metabolism in malaria patients.

    PubMed

    Snoep, Jacky L; Green, Kathleen; Eicher, Johann; Palm, Daniel C; Penkler, Gerald; du Toit, Francois; Walters, Nicolas; Burger, Robert; Westerhoff, Hans V; van Niekerk, David D

    2015-12-01

    We propose a hierarchical modelling approach to construct models for disease states at the whole-body level. Such models can simulate effects of drug-induced inhibition of reaction steps on the whole-body physiology. We illustrate the approach for glucose metabolism in malaria patients, by merging two detailed kinetic models for glucose metabolism in the parasite Plasmodium falciparum and the human red blood cell with a coarse-grained model for whole-body glucose metabolism. In addition we use a genome-scale metabolic model for the parasite to predict amino acid production profiles by the malaria parasite that can be used as a complex biomarker.

  11. Reduced cerebral glucose metabolism and increased brain capillary permeability following high-dose methotrexate chemotherapy: a positron emission tomographic study

    SciTech Connect

    Phillips, P.C.; Dhawan, V.; Strother, S.C.; Sidtis, J.J.; Evans, A.C.; Allen, J.C.; Rottenberg, D.A.

    1987-01-01

    Regional glucose metabolic rate constants and blood-to-brain transport of rubidium were estimated using positron emission tomography in an adolescent patient with a brain tumor, before and after chemotherapy with intravenous high-dose methotrexate. Widespread depression of cerebral glucose metabolism was apparent 24 hours after drug administration, which may reflect reduced glucose phosphorylation, and the influx rate constant for /sup 82/Rb was increased, indicating a drug-induced alteration in blood-brain barrier function. Associated changes in neuropsychological performance, electroencephalogram, and plasma amino acid concentration were identified in the absence of evidence of systemic methotrexate toxicity, suggesting primary methotrexate neurotoxicity.

  12. Integrated thermal treatment system study -- Phase 2 results. Revision 1

    SciTech Connect

    Feizollahi, F.; Quapp, W.J.

    1996-02-01

    This report presents the second phase of a study on thermal treatment technologies. The study consists of a systematic assessment of nineteen thermal treatment alternatives for the contact-handled mixed low-level waste (MLLW) currently stored in the US Department of Energy complex. The treatment alternatives consist of widely varying technologies for safely destroying the hazardous organic components, reducing the volume, and preparing for final disposal of the MLLW. The alternatives considered in Phase 2 were innovative thermal treatments with nine types of primary processing units. Other variations in the study examined the effect of combustion gas, air pollution control system design, and stabilization technology for the treatment residues. The Phase 1 study examined ten initial thermal treatment alternatives. The Phase 2 systems were evaluated in essentially the same manner as the Phase 1 systems. The alternatives evaluated were: rotary kiln, slagging kiln, plasma furnace, plasma gasification, molten salt oxidation, molten metal waste destruction, steam gasification, Joule-heated vitrification, thermal desorption and mediated electrochemical oxidation, and thermal desorption and supercritical water oxidation. The quantities, and physical and chemical compositions, of the input waste used in the Phase 2 systems differ from those in the Phase 1 systems, which were based on a preliminary waste input database developed at the onset of the Integrated Thermal Treatment System study. The inventory database used in the Phase 2 study incorporates the latest US Department of Energy information. All systems, both primary treatment systems and subsystem inputs, have now been evaluated using the same waste input (2,927 lb/hr). 28 refs., 88 figs., 41 tabs.

  13. Study of stationary phase metabolism via isotopomer analysis of amino acids from an isolated protein.

    PubMed

    Shaikh, Afshan S; Tang, Yinjie J; Mukhopadhyay, Aindrila; Martín, Héctor García; Gin, Jennifer; Benke, Peter I; Keasling, Jay D

    2010-01-01

    Microbial production of many commercially important secondary metabolites occurs during stationary phase, and methods to measure metabolic flux during this growth phase would be valuable. Metabolic flux analysis is often based on isotopomer information from proteinogenic amino acids. As such, flux analysis primarily reflects the metabolism pertinent to the growth phase during which most proteins are synthesized. To investigate central metabolism and amino acids synthesis activity during stationary phase, addition of fully (13)C-labeled glucose followed by induction of green fluorescent protein (GFP) expression during stationary phase was used. Our results indicate that Escherichia coli was able to produce new proteins (i.e., GFP) in the stationary phase, and the amino acids in GFP were mostly from degraded proteins synthesized during the exponential growth phase. Among amino acid biosynthetic pathways, only those for serine, alanine, glutamate/glutamine, and aspartate/asparagine had significant activity during the stationary phase.

  14. Study of Stationary Phase Metabolism Via Isotopomer Analysis of Amino Acids from an Isolated Protein

    SciTech Connect

    Shaikh, AfshanS.; Tang, YinjieJ.; Mukhopadhyay, Aindrila; Martin, Hector Garcia; Gin, Jennifer; Benke, Peter; Keasling, Jay D.

    2009-09-14

    Microbial production of many commercially important secondary metabolites occurs during stationary phase, and methods to measure metabolic flux during this growth phase would be valuable. Metabolic flux analysis is often based on isotopomer information from proteinogenic amino acids. As such, flux analysis primarily reflects the metabolism pertinent to the growth phase during which most proteins are synthesized. To investigate central metabolism and amino acids synthesis activity during stationary phase, addition of fully 13C-labeled glucose followed by induction of green fluorescent protein (GFP) expression during stationary phase was used. Our results indicate that Escherichia coli was able to produce new proteins (i.e., GFP) in the stationary phase, and the amino acids in GFP were mostly from degraded proteins synthesized during the exponential growth phase. Among amino acid biosynthetic pathways, only those for serine, alanine, glutamate/glutamine, and aspartate/asparagine had significant activity during the stationary phase.

  15. The Design of the IGE Evaluation Project Phase IV Comparative Studies. Comparative Study of Phase IV IGE Evaluation Project. Phase IV, Project Paper 80-2.

    ERIC Educational Resources Information Center

    Romberg, Thomas A.; And Others

    This paper outlines the design of two Comparative Studies of Phase IV of the Individually Guided Education (IGE) Evaluation Project. More than 2,000 elementary schools in 25 states use the IGE system. The Evaluation Project was designed to gain a comprehensive view of the system's operation and effectiveness. Phase IV investigated pupil outcomes,…

  16. Solid phases of spatially nanoconfined oxygen: A neutron scattering study

    SciTech Connect

    Kojda, Danny; Wallacher, Dirk; Hofmann, Tommy; Baudoin, Simon; Hansen, Thomas; Huber, Patrick

    2014-01-14

    We present a comprehensive neutron scattering study on solid oxygen spatially confined in 12 nm wide alumina nanochannels. Elastic scattering experiments reveal a structural phase sequence known from bulk oxygen. With decreasing temperature cubic γ-, orthorhombic β- and monoclinic α-phases are unambiguously identified in confinement. Weak antiferromagnetic ordering is observed in the confined monoclinic α-phase. Rocking scans reveal that oxygen nanocrystals inside the tubular channels do not form an isotropic powder. Rather, they exhibit preferred orientations depending on thermal history and the very mechanisms, which guide the structural transitions.

  17. Comparative study viruses with computer-aided phase microscope AIRYSCAN

    NASA Astrophysics Data System (ADS)

    Tychinsky, Vladimir P.; Koufal, Georgy E.; Perevedentseva, Elena V.; Vyshenskaia, Tatiana V.

    1996-12-01

    Traditionally viruses are studied with scanning electron microscopy (SEM) after complicated procedure of sample preparation without the possibility to study it under natural conditions. We obtained images of viruses (Vaccinia virus, Rotavirus) and rickettsias (Rickettsia provazekii, Coxiella burnetti) in native state with computer-aided phase microscope airyscan -- the interference microscope of Linnik layout with phase modulation of the reference wave with dissector image tube as coordinate-sensitive photodetector and computer processing of phase image. A light source was the He-Ne laser. The main result is coincidence of dimensions and shape of phase images with available information concerning their morphology obtained with SEM and other methods. The fine structure of surface and nuclei is observed. This method may be applied for virus recognition and express identification, investigation of virus structure and the analysis of cell-virus interaction.

  18. Antenna evaluation study for the shuttle multispectral radar, phase 2

    NASA Technical Reports Server (NTRS)

    Coffey, E. L., III; Carver, K. R.

    1977-01-01

    The results of the second phase of the Antenna Evaluation Study for the Shuttle Imaging Radar are presented. The objectives of Phase II were (1) to complete the specifications for the subarray test panels, (2) to begin a study of the effects of electrical and mechanical tolerance variations on overall SIRA performance, (3) to initiate the development of a mathematical model which adequately described the array performance and (4) to begin the development of a comprehensive computer program which will eventually simulate the performance characteristics of the antenna in a spaceborne environment. Items (2), (3), and (4) were begun in Phase I (ahead of schedule), and because of this, it has been possible to accelerate the Phase II modeling/simulation objectives to the point where simulations of expected mechanical/electrical errors have already been produced.

  19. Glucose Transport into Everted Sacks of Intestine of Mice: A Model for the Study of Active Transport.

    ERIC Educational Resources Information Center

    Deyrup-Olsen, Ingrith; Linder, Alison R.

    1979-01-01

    Described is a laboratory procedure which uses the small intestines of mice as models for the transport of glucose and other solutes. Demonstrations are suitable for either introductory or advanced physiology courses. (RE)

  20. Studies on pyrazinoylguanidine. 2. Comparative drug and dose effects on glucose and lipid metabolism in streptozotocin-induced diabetic rats.

    PubMed

    A-Rahim, Y I; Beyer, K H; Vesell, E S

    1996-03-01

    In streptozotocin (STZ)-induced diabetic rats, pyrazinoylguanidine (PZG) markedly reduced elevated fasting concentrations of plasma glucose, triglycerides, and cholesterol. In contrast, these parameters were unaffected by a sulfonylurea, glyburide, or by a biguanide, metformin. PZG's glucose- and lipid-lowering effects were dose-dependent. These metabolic effects were also investigated after: (a) pyrazinoic acid (PZA), a metabolite of PZG; (b) 3-amino-PZG, an analog of PZG, and (c) 3-amino-PZA, a hydrolytic product of 3-amino-PZG. PZA moderately reduced elevated fasting glucose and lipid concentrations in STZ-diabetic rats, suggesting partial medication of PZG's antidiabetic actions by PZA. Neither 3-amino-PZG nor 3-amino-PZA exerted any glucose- or lipid-lowering effect in STZ-diabetic rats.

  1. Cardiovascular responses to the ingestion of sugary drinks using a randomised cross-over study design: Does glucose attenuate the blood pressure-elevating effect of fructose?

    PubMed

    Grasser, Erik K; Dulloo, Abdul; Montani, Jean-Pierre

    2014-07-28

    Overconsumption of sugar-sweetened beverages has been implicated in the pathogenesis of CVD. The objective of the present study was to elucidate acute haemodynamic and microcirculatory responses to the ingestion of sugary drinks made from sucrose, glucose or fructose at concentrations similar to those often found in commercial soft drinks. In a randomised cross-over study design, twelve young healthy human subjects (seven men) ingested 500 ml tap water in which was dissolved 60 g of either sucrose, glucose or fructose, or an amount of fructose equivalent to that present in sucrose (i.e. 30 g fructose). Continuous cardiovascular monitoring was performed for 30 min before and at 60 min after ingestion of sugary drinks, and measurements included beat-to-beat blood pressure (BP) and impedance cardiography. Additionally, microvascular endothelial function testing was performed after iontophoresis of acetylcholine and sodium nitroprusside using laser Doppler flowmetry. Ingestion of fructose (60 or 30 g) increased diastolic and mean BP to a greater extent than the ingestion of 60 g of either glucose or sucrose (P< 0.05). Ingestion of sucrose and glucose increased cardiac output (CO; P< 0.05), index of contractility (P< 0.05) and stroke volume (P< 0.05), but reduced total peripheral resistance (TPR; P< 0.05), which contrasts with the tendency of fructose (60 and 30 g) to increase resistance. Microvascular endothelial function did not differ in response to the ingestion of various sugary drinks. In conclusion, ingestion of fructose, but not sucrose, increases BP in healthy human subjects. Although sucrose comprises glucose and fructose, its changes in TPR and CO are more related to glucose than to fructose.

  2. PLCO Ovarian Phase III Validation Study — EDRN Public Portal

    Cancer.gov

    Our preliminary data indicate that the performance of CA 125 as a screening test for ovarian cancer can be improved upon by additional biomarkers. With completion of one additional validation step, we will be ready to test the performance of a consensus marker panel in a phase III validation study. Given the original aims of the PLCO trial, we believe that the PLCO represents an ideal longitudinal cohort offering specimens for phase III validation of ovarian cancer biomarkers.

  3. 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

  4. Study on an improved wavelet shift-invariant threshold denoising for pulsed laser induced glucose photoacoustic signals

    NASA Astrophysics Data System (ADS)

    Wang, Zhengzi; Ren, Zhong; Liu, Guodong

    2015-10-01

    Noninvasive measurement of blood glucose concentration has become a hotspot research in the world due to its characteristic of convenient, rapid and non-destructive etc. The blood glucose concentration monitoring based on photoacoustic technique has attracted many attentions because the detected signal is ultrasonic signals rather than the photo signals. But during the acquisition of the photoacoustic signals of glucose, the photoacoustic signals are not avoid to be polluted by some factors, such as the pulsed laser, electronic noises and circumstance noises etc. These disturbances will impact the measurement accuracy of the glucose concentration, So, the denoising of the glucose photoacoustic signals is a key work. In this paper, a wavelet shift-invariant threshold denoising method is improved, and a novel wavelet threshold function is proposed. For the novel wavelet threshold function, two threshold values and two different factors are set, and the novel function is high order derivative and continuous, which can be looked as the compromise between the wavelet soft threshold denoising and hard threshold denoising. Simulation experimental results illustrate that, compared with other wavelet threshold denoising, this improved wavelet shift-invariant threshold denoising has higher signal-to-noise ratio(SNR) and smaller root mean-square error (RMSE) value. And this improved denoising also has better denoising effect than others. Therefore, this improved denoising has a certain of potential value in the denoising of glucose photoacoustic signals.

  5. Rye-Based Evening Meals Favorably Affected Glucose Regulation and Appetite Variables at the Following Breakfast; A Randomized Controlled Study in Healthy Subjects

    PubMed Central

    Sandberg, Jonna C.; Björck, Inger M. E.; Nilsson, Anne C.

    2016-01-01

    Background Whole grain has shown potential to prevent obesity, cardiovascular disease and type 2 diabetes. Possible mechanism could be related to colonic fermentation of specific indigestible carbohydrates, i.e. dietary fiber (DF). The aim of this study was to investigate effects on cardiometabolic risk factors and appetite regulation the next day when ingesting rye kernel bread rich in DF as an evening meal. Method Whole grain rye kernel test bread (RKB) or a white wheat flour based bread (reference product, WWB) was provided as late evening meals to healthy young adults in a randomized cross-over design. The test products RKB and WWB were provided in two priming settings: as a single evening meal or as three consecutive evening meals prior to the experimental days. Test variables were measured in the morning, 10.5–13.5 hours after ingestion of RKB or WWB. The postprandial phase was analyzed for measures of glucose metabolism, inflammatory markers, appetite regulating hormones and short chain fatty acids (SCFA) in blood, hydrogen excretion in breath and subjective appetite ratings. Results With the exception of serum CRP, no significant differences in test variables were observed depending on length of priming (P>0.05). The RKB evening meal increased plasma concentrations of PYY (0–120 min, P<0.001), GLP-1 (0–90 min, P<0.05) and fasting SCFA (acetate and butyrate, P<0.05, propionate, P = 0.05), compared to WWB. Moreover, RKB decreased blood glucose (0–120 min, P = 0.001), serum insulin response (0–120 min, P<0.05) and fasting FFA concentrations (P<0.05). Additionally, RKB improved subjective appetite ratings during the whole experimental period (P<0.05), and increased breath hydrogen excretion (P<0.001), indicating increased colonic fermentation activity. Conclusion The results indicate that RKB evening meal has an anti-diabetic potential and that the increased release of satiety hormones and improvements of appetite sensation could be beneficial in

  6. DFT studies of carbohydrate solvation: II. MD-DFTr of a super-molecule complex of glucose, explicit waters, and an implicit solvent (COSMO)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MD-DFTr studies are carried out on the super-molecule solvated complexes of glucose described in paper I. Included were ten explicit water molecules and an implicit solvation model, COSMO, superimposed upon the complex. Starting configurations were taken from DFTr optimized complexes resulting from ...

  7. Glucose regulates lipid metabolism in fasting king penguins.

    PubMed

    Bernard, Servane F; Orvoine, Jord; Groscolas, René

    2003-08-01

    This study aims to determine whether glucose intervenes in the regulation of lipid metabolism in long-term fasting birds, using the king penguin as an animal model. Changes in the plasma concentration of various metabolites and hormones, and in lipolytic fluxes as determined by continuous infusion of [2-3H]glycerol and [1-14C]palmitate, were examined in vivo before, during, and after a 2-h glucose infusion under field conditions. All the birds were in the phase II fasting status (large fat stores, protein sparing) but differed by their metabolic and hormonal statuses, being either nonstressed (NSB; n = 5) or stressed (SB; n = 5). In both groups, glucose infusion at 5 mg.kg-1.min-1 induced a twofold increase in glycemia. In NSB, glucose had no effect on lipolysis (maintenance of plasma concentrations and rates of appearance of glycerol and nonesterified fatty acids) and no effect on the plasma concentrations of triacylglycerols (TAG), glucagon, insulin, or corticosterone. However, it limited fatty acid (FA) oxidation, as indicated by a 25% decrease in the plasma level of beta-hydroxybutyrate (beta-OHB). In SB, glucose infusion induced an approximately 2.5-fold decrease in lipolytic fluxes and a large decrease in FA oxidation, as reflected by a 64% decrease in the plasma concentration of beta-OHB. There were also a 35% decrease in plasma TAG, a 6.5- and 2.8-fold decrease in plasma glucagon and corticosterone, respectively, and a threefold increase in insulinemia. These data show that in fasting king penguins, glucose regulates lipid metabolism (inhibition of lipolysis and/or of FA oxidation) and affects hormonal status differently in stressed vs. nonstressed individuals. The results also suggest that in birds, as in humans, the availability of glucose, not of FA, is an important determinant of the substrate mix (glucose vs. FA) that is oxidized for energy production.

  8. Establishment of in vitro model of erectile dysfunction for the study of high-glucose-induced angiopathy and neuropathy.

    PubMed

    Yin, G N; Park, S-H; Song, K-M; Limanjaya, A; Ghatak, K; Minh, N N; Ock, J; Ryu, J-K; Suh, J-K

    2017-03-01

    Penile erection requires complex interaction between vascular endothelial cells, smooth muscle cells, pericytes, and autonomic nerves. Diabetes mellitus is one of the most common causes of erectile dysfunction (ED) and multiple pathogenic factors, such as cavernous angiopathy and autonomic neuropathy, are associated with diabetic ED. Although a variety of animal models of diabetic ED play an important role in understanding pathophysiologic mechanisms of diabetes-induced ED, these animal models have limitations for addressing the exact cellular or molecular mechanisms involved in ED. Therefore, we established an in vitro model of ED for the study of high-glucose-induced angiopathy and neuropathy. We successfully isolated and cultivated mouse cavernous endothelial cells (MCECs) and mouse cavernous pericytes (MCPs). The cells were exposed to the normal-glucose (5 mmoL) or high-glucose (30 mmoL) condition for 48 h. In vitro matrigel assay revealed impairments in tube formation in primary cultured MCECs or MCPs exposed to high-glucose condition. To study cellular interaction between MCECs and MCPs, co-culture systems including indirect contact, indirect non-contact, and direct mixed co-culture system, were established. We observed impaired tube formation and increased permeability in MCECs-MCPs co-culture exposed to high-glucose condition. To evaluate the effect of high-glucose on neurite sprouting, the mouse major pelvic ganglion (MPG) tissue was harvested and cultivated in matrigel. Neurite outgrowth and nNOS-positive nerve fibers were significantly lower in MPG tissues exposed to the high-glucose condition than in the tissues exposed to the normal-glucose condition. We believe that in vitro model of ED will aid us to understand the role of each cellular component in the pathogenesis of diabetic ED, and also be a useful tool for determining the efficacy of candidate therapeutics targeting vascular or neuronal function. This model would present a new avenue for

  9. Intensity and phase fields behind Phase Shifting Masks studied with High Resolution Interference Microscopy

    NASA Astrophysics Data System (ADS)

    Puthankovilakam, Krishnaparvathy; Scharf, Toralf; Herzig, Hans Peter; Weichelt, Tina; Zeitner, Uwe; Vogler, Uwe; Voelkel, Reinhard

    2015-03-01

    The proximity printing industry is in real need of high resolution results and it can be done using Phase Shift Mask (PSM) or by applying Optical Proximity Correction (OPC). In our research we are trying to find out details of how light fields behind the structures of photo masks develop in order to determine the best conditions and designs for proximity printing. We focus here on parameters that are used in real situation with gaps up to 50 μm and structure sizes down to 2 μm. The light field evolution behind the structures is studied and delivers insight in to precisions and tolerances that need to be respected. It is the first time that an experimental analysis of light propagation through mask is presented in detail, which includes information on intensity and phase. The instrument we use is known as High Resolution Interference Microscopy (HRIM). HRIM is a Mach-Zehnder interferometer which is capable of recording three dimensional distributions of intensity and phase with diffraction limited resolution. Our characterization technique allows plotting the evolution of the desired light field and therefore printable structure till the desired proximity gap. In this paper we discuss in detail the evolution of intensity and phase fields of elbow or corner structure at different position behind a phase mask and interpret the main parameters. Of particular interest are tolerances against proximity gap variation and the resolution in printed structures.

  10. Application of capillary enzyme micro-reactor in enzyme activity and inhibitors studies of glucose-6-phosphate dehydrogenase.

    PubMed

    Camara, Mohamed Amara; Tian, Miaomiao; Guo, Liping; Yang, Li

    2015-05-15

    In this study, we present an on-line measurement of enzyme activity and inhibition of Glucose-6-phosphate dehydrogenase (G6PDH) enzyme using capillary electrophoresis based immobilized enzyme micro-reactor (CE-based IMER). The IMER was prepared using a two-step protocol based on electrostatic assembly. The micro-reactor exhibited good stability and reproducibility for on-line assay of G6PDH enzyme. Both the activity as well as the inhibition of the G6PDH enzyme by six inhibitors, including three metals (Cu(2+), Pb(2+), Cd(2+)), vancomycin, urea and KMnO4, were investigated using on-line assay of the CE-based IMERs. The enzyme activity and inhibition kinetic constants were measured using the IMERs which were found to be consistent with those using traditional off-line enzyme assays. The kinetic mechanism of each inhibitor was also determined. The present study demonstrates the feasibility of using CE-based IMERs for rapid and efficient on-line assay of G6PDH, an important enzyme in the pentosephosphate pathway of human metabolism.

  11. Estimating disease prevalence in two-phase studies.

    PubMed

    Alonzo, Todd A; Pepe, Margaret Sullivan; Lumley, Thomas

    2003-04-01

    Disease prevalence is ideally estimated using a 'gold standard' to ascertain true disease status on all subjects in a population of interest. In practice, however, the gold standard may be too costly or invasive to be applied to all subjects, in which case a two-phase design is often employed. Phase 1 data consisting of inexpensive and non-invasive screening tests on all study subjects are used to determine the subjects that receive the gold standard in the second phase. Naive estimates of prevalence in two-phase studies can be biased (verification bias). Imputation and re-weighting estimators are often used to avoid this bias. We contrast the forms and attributes of the various prevalence estimators. Distribution theory and simulation studies are used to investigate their bias and efficiency. We conclude that the semiparametric efficient approach is the preferred method for prevalence estimation in two-phase studies. It is more robust and comparable in its efficiency to imputation and other re-weighting estimators. It is also easy to implement. We use this approach to examine the prevalence of depression in adolescents with data from the Great Smoky Mountain Study.

  12. Regulation of glucose transport in skeletal muscle.

    PubMed

    Barnard, R J; Youngren, J F

    1992-11-01

    The entry of glucose into muscle cells is achieved primarily via a carrier-mediated system consisting of protein transport molecules. GLUT-1 transporter isoform is normally found in the sarcolemmal (SL) membrane and is thought to be involved in glucose transport under basal conditions. With insulin stimulation, glucose transport is accelerated by translocating GLUT-4 transporters from an intracellular pool out to the T-tubule and SL membranes. Activation of transporters to increase the turnover number may also be involved, but the evidence is far from conclusive. When insulin binds to its receptor, it autophosphorylates tyrosine and serine residues on the beta-subunit of the receptor. The tyrosine residues are thought to activate tyrosine kinases, which in turn phosphorylate/activate as yet unknown second messengers. Insulin receptor antibodies, however, have been reported to increase glucose transport without increasing kinase activity. Insulin resistance in skeletal muscle is a major characteristic of obesity and diabetes mellitus, especially NIDDM. A decrease in the number of insulin receptors and the ability of insulin to activate receptor tyrosine kinase has been documented in muscle from NIDDM patients. Most studies report no change in the intracellular pool of GLUT-4 transporters available for translocation to the SL. Both the quality and quantity of food consumed can regulate insulin sensitivity. A high-fat, refined sugar diet, similar to the typical U.S. diet, causes insulin resistance when compared with a low-fat, complex-carbohydrate diet. On the other hand, exercise increases insulin sensitivity. After an acute bout of exercise, glucose transport in muscle increases to the same level as with maximum insulin stimulation. Although the number of GLUT-4 transporters in the sarcolemma increases with exercise, neither insulin or its receptor is involved. After an initial acute phase, which may involve calcium as the activator, a secondary phase of increased

  13. Preliminary Studies of a Phase Modulation Technique for Measuring Chromaticity

    SciTech Connect

    Tan, Cheng-Yang; /Fermilab

    2006-04-01

    The classical method for measuring chromaticity is to slowly modulate the RF frequency and then measuring the betatron tune excursion. The technique that is discussed in this paper modulates instead the phase of the RF and then the chromaticity is obtained by phase demodulating the betatron tune. However, this technique requires knowledge of the betatron frequency in real time in order for the phase to be demodulated. Fortunately, the Tevatron has a tune tracker based on the phase locked loop principle which fits this requirement. A preliminary study with this technique has showed that it is a promising method for doing continuous chromaticity measurement and raises the possibility of doing successful chromaticity feedback with it.

  14. 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 ... Abnormal results include higher and lower glucose levels. Abnormal ... or fungus) Inflammation of the central nervous system Tumor

  15. Blood Test: Glucose

    MedlinePlus

    ... Your 1- to 2-Year-Old Blood Test: Glucose KidsHealth > For Parents > Blood Test: Glucose A A A What's in this article? What ... de sangre: glucosa What It Is A blood glucose test measures the amount of glucose (the main ...

  16. Tools for Studying Quantum Emergence near Phase Transitions

    NASA Astrophysics Data System (ADS)

    Imada, Masatoshi; Onoda, Shigeki; Mizusaki, Takahiro; Watanabe, Shinji

    2003-12-01

    We review recent studies on developing tools for quantum complex phenomena. The tools have been applied for clarifying the perspective of the Mott transitions and the phase diagram of metals, Mott insulators and magnetically ordered phases in the two-dimensional Hubbard model. The path-integral renormalization-group (PIRG) method has made it possible to numerically study correlated electrons even with geometrical frustration effects without biases . It has numerically clarified the phase diagram at zero temperature, T = 0, in the parameter space of the onsite Coulomb repulsion, the geometrical frustration amplitude and the chemical potential. When the bandwidth is controlled at half filling, the first-order transition between insulating and metallic phases is evidenced. In contrast, the filling-control transition shows diverging critical fluctuations for spin and charge responses with decreasing doping concentration. Near the Mott transition, a nonmagnetic spin-liquid phase appears in a region with large frustration effects. The phase is characterized remarkably by gapless spin excitations and the vanishing dispersion of spin excitations. Magnetic orders quantum mechanically melt through diverging magnon mass. The correlator projection method (CPM) is formulated as an extension of the operator projection theory. This method also allows an extension of the dynamical mean-field theory (DMFT) with systematic inclusion of the momentum dependence in the self-energy. It has enabled determining the phase diagram at T > 0, where the boundary surface of the first-order metal-insulator transition at half filling terminates on the critical end curve at T = Tc. The critical end curve is characterized by the diverging compressibility. The single particle spectra show strong renormalization of low-energy spectra, generating largely momentum dependent and flat dispersion. The results of two tools consistently suggest that the strong competitions of various phases with underlying

  17. Western Wind and Solar Integration Study Phase 2 (Presentation)

    SciTech Connect

    Lew, D.; Brinkman, G.; Ibanez, E.; Kumar, N.; Lefton, S.; Jordan, G.; Venkataraman, S.; King, J.

    2013-06-01

    This presentation accompanies Phase 2 of the Western Wind and Solar Integration Study, a follow-on to Phase 1, which examined the operational impacts of high penetrations of variable renewable generation on the electric power system in the West and was one of the largest variable generation studies to date. High penetrations of variable generation can induce cycling of fossil-fueled generators. Cycling leads to wear-and-tear costs and changes in emissions. Phase 2 calculated these costs and emissions, and simulated grid operations for a year to investigate the detailed impact of variable generation on the fossil-fueled fleet. The presentation highlights the scope of the study and results.

  18. Improving 18F-Fluoro-D-Glucose-Positron Emission Tomography/Computed Tomography Imaging in Alzheimer's Disease Studies

    PubMed Central

    Knešaurek, Karin

    2015-01-01

    The goal was to improve Alzheimer's 2-deoxy-2-18F-fluoro-D-glucose (18F FDG)-positron emission tomography (PET)/computed tomography (CT) imaging through application of a novel, hybrid Fourier-wavelet windowed Fourier transform (WFT) restoration technique, in order to provide earlier and more accurate clinical results. General Electric Medical Systems downward-looking sonar PET/CT 16 slice system was used to acquire studies. Patient data were acquired according the Alzheimer's disease Neuroimaging Initiative (ADNI) protocol. Here, we implemented Fourier-wavelet regularized restoration, with a Butterworth low-pass filter, order n = 6 and a cut-off frequency f = 0.35 cycles/pixel and wavelet (Daubechies, order 2) noise suppression. The original (PET-O) and restored (PET-R) ADNI subject PET images were compared using the Alzheimer's discrimination analysis by dedicated software. Forty-two PET/CT scans were used in the study. They were performed on eleven ADNI subjects at intervals of approximately 6 months. The final clinical diagnosis was used as a gold standard. For three subjects, the final clinical diagnosis was mild cognitive impairment and those 13 PET/CT studies were not included in the final comparison, as the result was considered as inconclusive. Using the reminding 29 PET/CT studies (23 AD and 6 normal), the sensitivity and specificity of the PET-O and PET-R were calculated. The sensitivity was 0.65 and 0.96 for PET-O and PET-R, respectively, and the specificity was 0.67 and 0.50 for PET-O and PET-R. The accuracy was 0.66 and 0.86 for PET-O and PET-R, respectively. The results of the study demonstrated that the accuracy of three-dimensional brain F-18 FDG PET images was significantly improved by Fourier-wavelet restoration filtering. PMID:26420987

  19. Quantifying the Contribution of Grape Hexoses to Wine Volatiles by High-Precision [U13C]-Glucose Tracer Studies

    PubMed Central

    Nisbet, Mark A.; Tobias, Herbert J.; Brenna, J. Thomas; Sacks, Gavin L.; Mansfield, Anna Katharine

    2016-01-01

    Many fermentation volatiles important to wine aroma potentially arise from yeast metabolism of hexose sugars, but assessing the relative importance of these pathways is challenging due to high endogenous hexose substrate concentrations. To overcome this problem, gas chromatography combustion isotope ratio mass spectrometry (GC-C-IRMS) was used to measure high-precision 13C/12C isotope ratios of volatiles in wines produced from juices spiked with tracer levels (0.01–1 APE) of uniformly labeled [U-13C]-glucose. The contribution of hexose to individual volatiles was determined from the degree of 13C enrichment. As expected, straight-chain fatty acids and their corresponding ethyl esters were derived almost exclusively from hexoses. Most fusel alcohols and their acetate esters were also majority hexose-derived, indicating the importance of anabolic pathways for their formation. Only two compounds were not derived primarily from hexoses (hexanol and isobutyric acid). This approach can be extended to other food systems or substrates for studying precursor–product relationships. PMID:24960193

  20. Novel phase I study combining G1 phase, S phase, and G2/M phase cell cycle inhibitors in patients with advanced malignancies

    PubMed Central

    Jain, Rajul K; Hong, David S; Naing, Aung; Wheler, Jennifer; Helgason, Thorunn; Shi, Nai-Yi; Gad, Yash; Kurzrock, Razelle

    2015-01-01

    PURPOSE: Cancer is a manifestation of aberrant cellular proliferation, and the cell cycle is one of the most successfully drugged targets in oncology. No prior study has been reported that simultaneously targets the 3 principal cell cycle phases populated by proliferating cells - G1, S, and G2/M. METHODS: Temsirolimus (G1 inhibitor), topotecan (S inhibitor), and bortezomib (G2/M inhibitor) were administered in combination to patients with advanced malignancies using a 3+3 dose escalation schedule to assess the safety and establish the maximum tolerated dose (primary endpoints) of this cell cycle targeting approach. An in silico pharmacodynamic model using established effects of each of these agents on the cell cycle was used to validate the regimen and to guide the dosing regimen. RESULTS: Sixty-two subjects were enrolled. The most common adverse events and dose-limiting toxicities were cytopenias, consistent with the cell cycle targeting approach employed. All cytopenias resolved to baseline values upon holding study drug administration. The maximum tolerated dose was temsirolimus 15 mg/kg IV D1, 8, 15; topotecan 2.8 mg/m2 IV D1, 8; and bortezomib 0.9 mg/m2 IV D1, 4, 8, 11 of a 21-day cycle. In silico modeling suggests the regimen induces cell population shifts from G2/M and S phases to G1 phase and the quiescent G0 phase. Eighteen percent of subjects (11/62) achieved partial response (n = 2, serous ovarian and papillary thyroid) or stable disease for > 6 months (n = 9). CONCLUSION: Combining drugs with inhibitory activity of G1 phase, S phase, and G2/M phase is safe and warrants further evaluation. PMID:26467427

  1. Enhancing the [13C]bicarbonate signal in cardiac hyperpolarized [1-13C]pyruvate MRS studies by infusion of glucose, insulin and potassium.

    PubMed

    Lauritzen, Mette Hauge; Laustsen, Christoffer; Butt, Sadia Asghar; Magnusson, Peter; Søgaard, Lise Vejby; Ardenkjær-Larsen, Jan Henrik; Åkeson, Per

    2013-11-01

    A change in myocardial metabolism is a known effect of several diseases. MRS with hyperpolarized (13)C-labelled pyruvate is a technique capable of detecting changes in myocardial pyruvate metabolism, and has proven to be useful for the evaluation of myocardial ischaemia in vivo. However, during fasting, the myocardial glucose oxidation is low and the fatty acid oxidation (β-oxidation) is high, which complicates the interpretation of pyruvate metabolism with the technique. The aim of this study was to investigate whether the infusion of glucose, insulin and potassium (GIK) could increase the myocardial glucose oxidation in the citric acid cycle, reflected as an increase in the [(13)C]bicarbonate signal in cardiac hyperpolarized [1-(13)C]pyruvate MRS measurements in fasted rats. Two groups of rats were infused with two different doses of GIK and investigated by MRS after injection of hyperpolarized [1-(13)C]pyruvate. No [(13)C]bicarbonate signal could be detected in the fasted state. However, a significant increase in the [(13)C]bicarbonate signal was observed by the infusion of a high dose of GIK. This study demonstrates that a high [(13)C]bicarbonate signal can be achieved by GIK infusion in fasted rats. The increased [(13)C]bicarbonate signal indicates an increased flux of pyruvate through the pyruvate dehydrogenase enzyme complex and an increase in myocardial glucose oxidation through the citric acid cycle.

  2. Experimental study on confined two-phase jets

    SciTech Connect

    Levy, Y.; Albagli, D. )

    1991-09-01

    The basic mixing phenomena in confined, coaxial, particle-laden turbulent flows are studied within the scope of ram combustor research activities. Cold-flow experiments in a relatively simple configuration of confined, coaxial two-phase jets provided both qualitative and quantitative insight on the multiphase mixing process. Pressure, tracer gas concentration, and two-phase velocity measurements revealed that unacceptably long ram combustors are needed for complete confined jet mixing. Comparison of the experimental results with a previous numerical simulation displayed a very good agreement, indicating the potential of the experimental facility for validation of computational parametric studies. 38 refs.

  3. Analysis of kinetic, stoichiometry and regulation of glucose and glutamine metabolism in hybridoma batch cultures using logistic equations

    PubMed Central

    Acosta, María Lourdes; Sánchez, Asterio; García, Francisco; Molina, Emilio

    2007-01-01

    Batch cultures were carried out to study the kinetic, stoichiometry, and regulation of glucose and glutamine metabolism of a murine hybridoma line. Asymmetric logistic equations (ALEs) were used to fit total and viable cell density, and nutrient and metabolite/product concentrations. Since these equations were analytically differentiable, specific rates and yield coefficients were readily calculated. Asymmetric logistic equations described satisfactorily uncontrolled batch cultures, including death phase. Specific growth rate showed a Monod-type dependence on initial glucose and glutamine concentrations. Yield coefficients of cell and lactate from glucose, and cell and ammonium from glutamine were all found to change dramatically at low residual glucose and glutamine concentrations. Under stoichiometric glucose limitation, the glucose-to-cell yield increased and glucose-to-lactate yield decreased, indicating a metabolic shift. Under stoichiometric glutamine limitation the glutamine-to-cell and glutamine-to-ammonium yields increased, but also glucose-to-cell yield increased and the glucose-to-lactate yield decreased. Monoclonal antibody production was mainly non-growth associated, independently of glucose and glutamine levels. PMID:19003011

  4. Differential Effects of Red Meat/Refined Grain Diet and Dairy/Chicken/Nuts/Whole Grain Diet on Glucose, Insulin and Triglyceride in a Randomized Crossover Study.

    PubMed

    Kim, Yoona; Keogh, Jennifer B; Clifton, Peter M

    2016-10-30

    Epidemiological studies suggest that a diet high in processed meat, with a high glycemic index is associated with an increased risk of type 2 diabetes. It is not clear if this is due to altered insulin sensitivity or an enhanced postprandial glucose. We aimed to compare the acute metabolic response of two different types of meals after ingestion of the matching diet for four weeks. The study was a randomized, crossover acute meal study. Volunteers consumed either a red meat/refined grain meal or a dairy/chicken/nuts/wholegrain meal after four weeks of the matching diet. After a three-week washout period and four weeks of the alternate diet, they consumed the matching meal. The diets differed with respect to both protein and carbohydrate sources. Blood samples were taken for 180 min for the measurement of glucose, insulin, C-peptide and triglyceride. Fifty-one participants (age: 35.1 ± 15.6 years; body mass index: 27.7 ± 6.9 kg/m², 17 with normal and 34 with impaired glucose tolerance) completed two meal tests. The area under the curve (p < 0.001) and incremental area under the curve (p = 0.001) for insulin was significantly higher after the red meat/refined grain diet than after the dairy/chicken/nuts/whole grain diet. There was an interaction between meal and glucose tolerance group (p < 0.05) in the area under the curve (AUC) and the incremental area under the curve (iAUC) of glucose; the red meat/refined grain diet increased glucose relative to the dairy/chicken/nuts/whole grain diet only in the normal group (+2.5 mmol/L/3 h). The red meat/refined grain diet increased glucose and insulin responses compared with the dairy/chicken/nuts/whole grain diet. This meal pattern would increase pancreatic stress long term and may account for the increased risk of type 2 diabetes with this diet.

  5. Differential Effects of Red Meat/Refined Grain Diet and Dairy/Chicken/Nuts/Whole Grain Diet on Glucose, Insulin and Triglyceride in a Randomized Crossover Study

    PubMed Central

    Kim, Yoona; Keogh, Jennifer B.; Clifton, Peter M.

    2016-01-01

    Epidemiological studies suggest that a diet high in processed meat, with a high glycemic index is associated with an increased risk of type 2 diabetes. It is not clear if this is due to altered insulin sensitivity or an enhanced postprandial glucose. We aimed to compare the acute metabolic response of two different types of meals after ingestion of the matching diet for four weeks. The study was a randomized, crossover acute meal study. Volunteers consumed either a red meat/refined grain meal or a dairy/chicken/nuts/wholegrain meal after four weeks of the matching diet. After a three-week washout period and four weeks of the alternate diet, they consumed the matching meal. The diets differed with respect to both protein and carbohydrate sources. Blood samples were taken for 180 min for the measurement of glucose, insulin, C-peptide and triglyceride. Fifty-one participants (age: 35.1 ± 15.6 years; body mass index: 27.7 ± 6.9 kg/m2, 17 with normal and 34 with impaired glucose tolerance) completed two meal tests. The area under the curve (p < 0.001) and incremental area under the curve (p = 0.001) for insulin was significantly higher after the red meat/refined grain diet than after the dairy/chicken/nuts/whole grain diet. There was an interaction between meal and glucose tolerance group (p < 0.05) in the area under the curve (AUC) and the incremental area under the curve (iAUC) of glucose; the red meat/refined grain diet increased glucose relative to the dairy/chicken/nuts/whole grain diet only in the normal group (+2.5 mmol/L/3 h). The red meat/refined grain diet increased glucose and insulin responses compared with the dairy/chicken/nuts/whole grain diet. This meal pattern would increase pancreatic stress long term and may account for the increased risk of type 2 diabetes with this diet. PMID:27809219

  6. A Study on Phase Changes of Heterogeneous Composite Materials

    NASA Astrophysics Data System (ADS)

    Hirasawa, Yoshio; Saito, Akio; Takegoshi, Eisyun

    In this study, a phase change process in heterogeneous composite materials which consist of water and coiled copper wires as conductive solid is investigated by four kinds of typical calculation models : 1) model-1 in which the effective thermal conductivity of the composite material is used, 2) model-2 in which a fin metal acts for many conductive solids, 3) model-3 in which the effective thermal conductivities between nodes are estimated and three-dimensional calculation is performed, 4) model-4 proposed by authors in the previous paper in which effective thermal conductivity is not needed. Consequently, model-1 showed the phase change rate considerably lower than the experimental results. Model-2 gave the larger amount of the phase change rate. Model-3 agreed well with the experiment in the case of small coil diameter and relatively large Vd. Model-4 showed a very well agreement with the experiment in the range of this study.

  7. Simulation on how to customize glucose adjustment method for non-invasive blood glucose sensing by NIRS

    NASA Astrophysics Data System (ADS)

    Min, Xiaolin; Jiang, Jingying; Zou, Da; Liu, Rong; Xu, Kexin

    2013-02-01

    Previous studies have shown the limitations of taking OGTT (Oral Glucose Tolerance Test) as the glucose adjustment protocol for non-invasive blood glucose sensing. Previous studies built a mathematical model of glucose metabolism system-IMM (the Integrated Minimal Model) to probe other available adjustment methods. In this talk, a further study would be focused on more detailed combination options of different glucose input types for glucose adjustment projects in non-invasive blood glucose sensing. And predictive models of blood glucose concentration have been established by means of partial least squares (PLS) method, which could be used to evaluate the quality of different glucose adjustment options. Results of PLS modeling suggested that predictive models under combined glucose input types, compared with OGTT, show a great enhancement in the stability. This would finally improve the precision of non-invasive blood glucose sensing.

  8. Comparison of thermochemistry of aspartame (artificial sweetener) and glucose.

    PubMed

    Rashidian, Mohammad; Fattahi, Alireza

    2009-01-05

    We have compared the gas phase thermochemical properties of aspartame (artificial sweetener) and alpha- and beta-glucose. These parameters include metal ion affinities with Li(+)-, Na(+)-, K(+)-, Mg(+2)-, Ca(+2)-, Fe(+2)-, Zn(+2)-ions, and chloride ion affinity by using DFT calculations. For example, for aspartame, the affinity values for the above described metal ions are, respectively, 86.5, 63.2, 44.2, 255.4, 178.4, 235.4, and 300.4, and for beta-glucose are 65.2, 47.3 32.9, 212.9, 140.2, 190.1, and 250.0 kcal mol(-1), respectively. The study shows differences between the intrinsic chemistry of aspartame and glucose.

  9. Mother-daughter correlation of central obesity and other noncommunicable disease risk factors: Tehran Lipid and Glucose Study.

    PubMed

    Heidari, Zahra; Hosseinpanah, Farhad; Barzin, Maryam; Safarkhani, Maryam; Azizi, Fereidoun

    2015-03-01

    This study aimed to investigate the mother-daughter correlation for central obesity and other noncommunicable disease risk factors. The authors used metabolic and anthropometric data from the Tehran Lipid and Glucose Study, enrolling 1041 mother-daughter pairs for the current study. Three age strata were defined: 3 to 9 years for childhood (146 mother-daughter pairs), 10 to 17 years for adolescence (395 mother-daughter pairs), and 18 to 25 years for early adulthood (500 mother-daughter pairs). Familial associations for central obesity and other noncommunicable disease risk factors were assessed. The prevalence of central obesity was 44.7% in mothers and 11.2% in daughters (6.2% in the 3-9, 19.2% in the 10-17, and 6.4% in the 18-25 years groups). Mothers with central obesity were more likely than nonobese mothers to have daughters with central obesity (10.5% and 1.7%, respectively; P = .0001). Central obesity indices among daughters were positively correlated with those of their mothers in all 3 age strata. Correlations for other noncommunicable disease risk factors were analyzed before and after adjusting the risk factor levels for mothers' and daughters' waist circumferences (WCs) within each group to determine whether risk factor correlations were, in part, a result of the central obesity correlations. After the non-communicable disease risk factor levels of participants were adjusted for their WCs, the mother-daughter correlations remained significant. The consistent association of central obesity between mothers and daughters may indicate the key role that could be played by the mother in the primary prevention of central obesity, particularly in high-risk families.

  10. Electrostatic levitation studies of supercooled liquids and metastable solid phases

    NASA Astrophysics Data System (ADS)

    Rustan, Gustav Errol

    been carried out to study the metastable phase formation in an Fe83B17 near eutectic alloy. Initial supercooling measurements using the ISU-ESL identified the formation of three metastable phases: a precipitate phase that shows stable coexistence with the deeply supercooled liquid, and two distinct bulk solidification phases. To identify the structure of the metastable phases, the Washington University Beamline ESL (WU-BESL) has been used to perform in-situ high energy x-ray diffraction measurements of the metastable phases. Based on the x-ray results, the precipitate phase has been identified as bcc-Fe, and the more commonly occurring bulk solidification product has been found to be a two-phase mixture of Fe23B6 plus fcc-Fe, which appears, upon cooling, to transform into a three phase mixture of Fe23B6, bcc-Fe, and an as-yet unidentified phase, with the transformation occurring at approximately the expected fcc-to-bcc transformation temperature of pure Fe. To further characterize the multi-phase metastable alloy, the ISU-ESL has been used to perform measurements of volume thermal expansion via the videographic technique, as well as RF susceptibility via the TDO technique. The results of the thermal expansion and susceptibility data have been found to be sensitive indicators of additional structural changes that may be occurring in the metastable solid at temperatures below 1000 K, and the susceptibility data has revealed that three distinct ferromagnetic phase transitions take place within the multi-phase mixture. Based on these results, it has been hypothesized that there may be an additional transformation taking place that leads to the formation of either bct- or o-Fe3B in addition to the Fe23B6 phase, although further work is required to test this hypothesis.

  11. Non-invasive measurement of blood glucose level by time-resolved transmission spectroscopy: A feasibility study

    NASA Astrophysics Data System (ADS)

    Sun, Meixiu; Chen, Nanguang

    2012-03-01

    An optical spectroscopic method is investigated theoretically for in vivo measurement of blood glucose concentration. This method is based on dynamic dual wavelength (610 nm and 810 nm) time-resolved measurements under a condition of artificial blood flow kinetics in a human finger. The influence of glucose concentration on absorption and reduced scattering coefficients of the whole blood is simulated using the T-matrix method. The scattering centers, RBC aggregation, under the artificial — kinetics condition are modeled as spheroid. The modified parametric slopes were derived from the Laplace transformed data of the time-resolved transmittance. The results show that an appropriate selection of the Laplace parameter can lead to enhanced sensitivity for glucose measurement.

  12. 13C-nuclear magnetic resonance spectroscopy studies of hepatic glucose metabolism in normal subjects and subjects with insulin-dependent diabetes mellitus.

    PubMed Central

    Cline, G W; Rothman, D L; Magnusson, I; Katz, L D; Shulman, G I

    1994-01-01

    To determine the effect of insulin-dependent diabetes mellitus (IDDM) on rates and pathways of hepatic glycogen synthesis, as well as flux through hepatic pyruvate dehydrogenase, we used 13C-nuclear magnetic resonance spectroscopy to monitor the peak intensity of the C1 resonance of the glucosyl units of hepatic glycogen, in combination with acetaminophen to sample the hepatic UDP-glucose pool and phenylacetate to sample the hepatic glutamine pool, during a hyperglycemic-hyperinsulinemic clamp using [1-13C]-glucose. Five subjects with poorly controlled IDDM and six age-weight-matched control subjects were clamped at a mean plasma glucose concentration of approximately 9 mM and mean plasma insulin concentrations approximately 400 pM for 5 h. Rates of hepatic glycogen synthesis were similar in both groups (approximately 0.43 +/- 0.09 mumol/ml liver min). However, flux through the indirect pathway of glycogen synthesis (3 carbon units-->-->glycogen) was increased by approximately 50% (P < 0.05), whereas the relative contribution of pyruvate oxidation to TCA cycle flux was decreased by approximately 30% (P < 0.05) in the IDDM subjects compared to the control subjects. These studies demonstrate that patients with poorly controlled insulin-dependent diabetes mellitus have augmented hepatic gluconeogenesis and relative decreased rates of hepatic pyruvate oxidation. These abnormalities are not immediately reversed by normalizing intraportal concentrations of glucose, insulin, and glucagon and may contribute to postprandial hyperglycemia. PMID:7989593

  13. Mass spectrometric study of glucose and cellobiose produced during enzymatic hydrolysis of alpha-cellulose extracted from oak late-wood annual rings.

    PubMed

    Sensuła, Barbara M; Derrick, Peter J; Bickerton, John C; Pazdur, Anna

    2009-07-01

    We present the first results concerning interannual variations in concentrations of glucose and cellobiose, obtained through enzymatic hydrolysis of alpha-cellulose. The alpha-cellulose was extracted from late-wood of oak. The tree-ring chronologies, wood components and their physical and chemical properties provide information about the ecosystem in which the tree grew, and thus information regarding climate variability and the impact of human activity in the past. The large molecular size and insolubility make it difficult to determine precisely the chemical and physical properties of the intact cellulose polymer. Enzymatic hydrolysis is the principal method of degradation of cellulose. In this study the feasibility has been examined of characterizing alpha-cellulose through analysis by mass spectrometry (MS) of the degradation products from hydrolysis. Degradation of alpha-cellulose was possible without using alkaline or acid buffers. Analysis by MS provided the opportunity to obtain information on the biodegradation of saccharides. The presence of cellobiose and glucose in the degradation product was evidenced by the mass spectra. We have compared the abundances of these glucose and cellobiose ions with carbon isotope ratios, the efficiency of extraction of alpha-cellulose from the wood and tree-ring width indices. The challenge is to establish, with respect to climate changes and environmental conditions, the significance of the variations from one year to another in the observed abundances of glucose and cellobiose ions.

  14. 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.

  15. Inhibition of sweet chemosensory receptors alters insulin responses during glucose ingestion in healthy adults: a randomized crossover interventional study.

    PubMed

    Karimian Azari, Elnaz; Smith, Kathleen R; Yi, Fanchao; Osborne, Timothy F; Bizzotto, Roberto; Mari, Andrea; Pratley, Richard E; Kyriazis, George A

    2017-04-01

    Background: Glucose is a natural ligand for sweet taste receptors (STRs) that are expressed on the tongue and in the gastrointestinal tract. Whether STRs directly contribute to the regulation of glucose homeostasis in response to glucose ingestion is unclear.Objective: We sought to determine the metabolic effects of the pharmacologic inhibition of STRs in response to an oral glucose load in healthy lean participants.Design: Ten healthy lean participants with a body mass index (in kg/m(2)) of 22.4 ± 0.8 were subjected to an oral-glucose-tolerance test (OGTT) on 4 separate days with the use of a randomized crossover design. Ten minutes before the 75-g OGTT, participants consumed a preload solution of either 300 parts per million (ppm) saccharin or water with or without the addition of 500 ppm lactisole, a human-specific inhibitor of STRs. When present, lactisole was included in both the preload and OGTT solutions. We assessed plasma responses of glucose, insulin, C-peptide, glucagon, glucagon-like peptides 1 and 2, gastric inhibitory peptide, acetaminophen, and 3-O-methylglucose. With the use of mathematical modeling, we estimated gastric emptying, glucose absorption, β-cell function, insulin sensitivity and clearance, and the portal insulin:glucagon ratio.Results: The addition of lactisole to the OGTT caused increases in the plasma responses of insulin (P = 0.012), C-peptide (P = 0.004), and the insulin secretory rate (P = 0.020) compared with the control OGTT. The addition of lactisole also caused a slight reduction in the insulin sensitivity index independent of prior saccharin consumption (P < 0.025). The ingestion of saccharin before the OGTT did not alter any of the measured variables but eliminated the effects of lactisole on the OGTT.Conclusion: The pharmacologic inhibition of STRs in the gastrointestinal tract alters insulin responses during an oral glucose challenge in lean healthy participants. This trial was registered at clinicaltrials.gov as NCT

  16. Phase aberration simulation study of MRgFUS breast treatments

    PubMed Central

    Farrer, Alexis I.; Almquist, Scott; Dillon, Christopher R.; Neumayer, Leigh A.; Parker, Dennis L.; Christensen, Douglas A.; Payne, Allison

    2016-01-01

    Purpose: This simulation study evaluates the effects of phase aberration in breast MR-guided focused ultrasound (MRgFUS) ablation treatments performed with a phased-array transducer positioned laterally to the breast. A quantification of these effects in terms of thermal dose delivery and the potential benefits of phase correction is demonstrated in four heterogeneous breast numerical models. Methods: To evaluate the effects of varying breast tissue properties on the quality of the focus, four female volunteers with confirmed benign fibroadenomas were imaged using 3T MRI. These images were segmented into numerical models with six tissue types, with each tissue type assigned standard acoustic properties from the literature. Simulations for a single-plane 16-point raster-scan treatment trajectory centered in a fibroadenoma in each modeled breast were performed for a breast-specific MRgFUS system. At each of the 16 points, pressure patterns both with and without applying a phase correction technique were determined with the hybrid-angular spectrum method. Corrected phase patterns were obtained using a simulation-based phase aberration correction technique to adjust each element’s transmit phase to obtain maximized constructive interference at the desired focus. Thermal simulations were performed for both the corrected and uncorrected pressure patterns using a finite-difference implementation of the Pennes bioheat equation. The effect of phase correction was evaluated through comparison of thermal dose accumulation both within and outside a defined treatment volume. Treatment results using corrected and uncorrected phase aberration simulations were compared by evaluating the power required to achieve a 20 °C temperature rise at the first treatment location. The extent of the volumes that received a minimum thermal dose of 240 CEM at 43 °C inside the intended treatment volume as well as the volume in the remaining breast tissues was also evaluated in the form of

  17. Solution convergence study during launch phase using limited tracking data

    NASA Technical Reports Server (NTRS)

    Premkumar, R. I.

    1988-01-01

    Orbit determination accuracies during critical phases at launch, when data are available from only one station, can be enhanced using angle data with conventional Doppler and range data. A study performed on the forthcoming Japanese ETS-5 mission indicates that this requires correct handling of the angle biases. This was verified using actual tracking data received from the BS-2B launch.

  18. Western Wind and Solar Integration Study Phase 3: Technical Overview

    SciTech Connect

    2015-11-01

    Technical fact sheet outlining the key findings of Phase 3 of the Western Wind and Solar Integration Study (WWSIS-3). NREL and GE find that with good system planning, sound engineering practices, and commercially available technologies, the Western grid can maintain reliability and stability during the crucial first minute after grid disturbances with high penetrations of wind and solar power.

  19. A Study of Structural Phase Transitions Using Light Scattering Techniques.

    DTIC Science & Technology

    1981-12-01

    n.g (a" &"I* L TYPE OF REPORT a PERID COVER=o rinal Report, A Study of structural phase transitions using October 1981 light scattering tenchniques S...SWWJUTY CLPWICATION OP ThIS PAGE (VIM1- Sum • . i i - • .. . . . ’ ’ .... . . . ’ ’ ’ . . L .. .. . ’.. . Table of contents 1) Results Page (a

  20. Nucleation and growth studies of crystalline carbon phases at nanoscale

    NASA Astrophysics Data System (ADS)

    Mani, Radhika C.

    Understanding the nucleation and early stage growth of crystals from the vapor phase is important for realizing large-area single-crystal quality films, controlled synthesis of nanocrystals, and the possible discovery of new phases of materials. Carbon provides the most interesting system because all its known crystalline phases (diamond, graphite and carbon nanotubes) are technologically important materials. Hence, this dissertation is focused on studying the nucleation and growth of carbon phases synthesized from the vapor phase. Nucleation experiments were performed in a microwave plasma chemical vapor deposition (CVD) reactor, and the resulting carbon nanocrystals were analyzed primarily using electron nanodiffraction and Raman spectroscopy. These studies led to the discovery of two new crystalline phases of sp 3 carbon other than diamond: face-centered and body-centered cubic carbon. Nanodiffraction results revealed possible hydrogen substitution into diamond-cubic lattices, indicating that these new phases probably act as intermediates in diamond nucleation. Nucleation experiments also led to the discovery of two new morphologies for sp2 carbon: nanocrystals of graphite and tapered, hollow 1-D structures termed here as "carbon nanopipettes". A Kinetic Monte Carlo (KMC) algorithm was developed to simulate the growth of individual diamond crystals from the vapor phase, starting with small clusters of carbon atoms (or seeds). Specifically, KMC simulations were used to distinguish the kinetic rules that give rise to a star-shaped decahedral morphology compared to decahedral crystals. KMC simulations revealed that slow adsorption on the {111} step-propagation sites compared to kink sites leads to star-decahedral crystals, and higher adsorption leads to decahedral crystals. Since the surfaces of the nanocrystals of graphite and nanopipettes were expected to be composed primarily of edge-plane sites, the electrochemical behavior of both these materials were

  1. Alternating-phase focusing: A model to study nonlinear dynamics

    SciTech Connect

    Sagalovsky, L.; Delayen, J.R.

    1992-09-01

    We discuss a new model to study alternating-phase focusing (APF). Our approach is based on representing the accelerating electric field with a continuous phase modulated traveling wave. The resulting nonlinear equations of motion can be solved analytically to predict the regions of stable APF motion. We also identify the key parameters which adequately describe the physics of APF. The model is believed to be applicable to low-{beta} ion linacs with short independently-controlled superconducting cavities being developed at ANL.

  2. Alternating-phase focusing: A model to study nonlinear dynamics

    SciTech Connect

    Sagalovsky, L.; Delayen, J.R.

    1992-01-01

    We discuss a new model to study alternating-phase focusing (APF). Our approach is based on representing the accelerating electric field with a continuous phase modulated traveling wave. The resulting nonlinear equations of motion can be solved analytically to predict the regions of stable APF motion. We also identify the key parameters which adequately describe the physics of APF. The model is believed to be applicable to low-{beta} ion linacs with short independently-controlled superconducting cavities being developed at ANL.

  3. Gas-Phase Studies of Formamidopyrimidine Glycosylase (Fpg) Substrates.

    PubMed

    Kiruba, G S M; Xu, Jiahui; Zelikson, Victoria; Lee, Jeehiun K

    2016-03-07

    Gas-phase thermochemical properties (tautomerism, acidity, and proton affinity) have been measured and calculated for a series of nucleobase derivatives that have not heretofore been examined under vacuum. The studied species are substrates for the enzyme formamidopyrimidine glycosylase (Fpg), which cleaves damaged nucleobases from DNA. The gas-phase results are compared and contrasted to solution-phase data, to afford insight into the Fpg mechanism. Calculations are also used to probe the energetics of various possible mechanisms and to predict isotope effects that could potentially allow for discrimination between different mechanisms. Specifically, (18) O substitution at the ribose O4' is predicted to result in a normal kinetic isotope effect (KIE) for a ring-opening "endocyclic" mechanism and an inverse KIE for a direct base excision "exocyclic" pathway.

  4. Monte Carlo study of Dirac semimetals phase diagram

    NASA Astrophysics Data System (ADS)

    Braguta, V. V.; Katsnelson, M. I.; Kotov, A. Yu.; Nikolaev, A. A.

    2016-11-01

    In this paper the phase diagram of Dirac semimetals is studied within a lattice Monte Carlo simulation. In particular, we concentrate on the dynamical chiral symmetry breaking which results in a semimetal-insulator transition. Using numerical simulation, we determine the values of the critical coupling constant of the semimetal-insulator transition for different values of the anisotropy of the Fermi velocity. This measurement allows us to draw a tentative phase diagram for Dirac semimetals. It turns out that within the Dirac model with Coulomb interaction both Na3Bi and Cd3As2 , known experimentally to be Dirac semimetals, would lie deep in the insulating region of the phase diagram. This result probably shows a decisive role of screening of the interelectron interaction in real materials, similar to the situation in graphene.

  5. A 220 GHz reflection-type phased array concept study

    NASA Astrophysics Data System (ADS)

    Hedden, Abigail S.; Dietlein, Charles R.; Wikner, David A.

    2011-05-01

    The goal of this project is to enable light-weight, durable, and portable systems capable of performing standoff detection of person-borne improvised explosive devices (PB-IEDs) through the development of millimeter-wave reflection-type phased arrays. Electronic beam steering eliminates the need for complex mechanical scanners that are commonly implemented with millimeter-wave imaging systems and would reduce overall system size and weight. We present a concept study of a 220 GHz reflection-type phased array for the purpose of performing beam scanning of a confocal reflector system. Requirements for effective imaging of the desired target region are established, including spatial resolution, total scan angle, and number of image pixels achievable. We examine the effects of array architecture on beam characteristics as it is scanned off broadside, including Gaussicity and encircled energy. Benchmark requirements are determined and compared with the capabilities of several potential phase shifter technologies, including MEMS-based variable capacitor phase shifters, switches, and varactor diode-based phase shifters.

  6. Enzyme incorporated microfluidic device for in-situ glucose detection in water-in-air microdroplets.

    PubMed

    Piao, Yunxian; Han, Dong Ju; Azad, Mohammad Reza; Park, Minsu; Seo, Tae Seok

    2015-03-15

    Droplet generating microfluidic systems can provide miniaturized bioanalytical tools by using the homogenous and high-throughput droplets as nanoreactors. In this study, we demonstrated a sensitive and in-situ glucose monitoring system using water-in-air droplets in an enzyme incorporated microfluidic device. A thin film structure of a glucose oxidase (GOx) enzyme immobilized hydrogel was constructed in the middle of the microfluidic channel, and nanoliter scaled water-in-air droplets which contain a glucose sample, horseradish peroxidase (HRP), and an Amplex Red substrate were generated by flow focusing of water phase with air. Once the droplets passed through the enzyme trapped hydrogel, the droplets temporarily halted and a GOx mediated catalytic reaction with glucose proceeded, resulting in producing fluorescent resorufin products in the droplets. With optimized conditions such as the thickness of a hydrogel film and the size and flowing rate of droplets, fluorescence intensities of the released droplets linearly increased in proportional to the glucose concentration up to 3mM, and the limit of detection was calculated as 6.64µM. A spiked glucose in a real urine sample was also successfully analyzed, and the functionality of the proposed enzyme immobilized microfluidic chip was maintained for at least two weeks without loss of enzymatic activity and detection sensitivity. Thus, our methodology suggests a novel droplet based glucose sensing chip which can monitor glucose in a real-time and high-throughput manner.

  7. Impact of diabetes duration on achieved reductions in glycated haemoglobin, fasting plasma glucose and body weight with liraglutide treatment for up to 28 weeks: a meta‐analysis of seven phase III trials

    PubMed Central

    Bailey, T.; Barkholt Christensen, S.; Nauck, M. A.

    2016-01-01

    This meta‐analysis of seven randomized, placebo‐controlled studies (total 3222 patients) evaluated whether type 2 diabetes (T2D) duration affects the changes in blood glucose control and body weight that can be achieved with liraglutide and placebo. With liraglutide 1.2 mg, shorter diabetes duration was associated with a significantly greater, but clinically non‐relevant, difference in glycated haemoglobin (HbA1c) reduction (p < 0.05), i.e. a 0.18% (1.96 mmol/mol) reduction in HbA1c per 10 years shorter diabetes duration. With liraglutide 1.8 mg, shorter diabetes duration was associated with a small but statistically significant trend for greater fasting plasma glucose (FPG) reduction (p < 0.05), i.e. a 0.38 mmol/l reduction in FPG per 10 years shorter diabetes duration. Neither the liraglutide 1.8 mg nor placebo results showed a significant association between HbA1c and diabetes duration and neither the liraglutide 1.2 mg nor placebo results showed a significant association between FPG and diabetes duration. Likewise, neither liraglutide nor placebo showed a significant association between change in weight and diabetes duration. These results suggest diabetes duration has a clinically negligible effect on achievable blood glucose control and weight outcomes with liraglutide and placebo in patients with T2D. PMID:26679282

  8. Multiphasic Absorption of Glucose and 3-O-Methyl Glucose by Aged Potato Slices 1

    PubMed Central

    Linask, Juri; Laties, George G.

    1973-01-01

    The isotherm for glucose absorption by aged potato (Solanum tuberosum var. Russet Burbank) discs shows four distinct phases in the concentration ranges 1.0 to 75 μm, 75 μm to 1.5 mm, 1.5 to 15 mm, and 15 to 100 mm, respectively. Each segment of the multiphasic isotherm, when plotted reciprocally by the method of Lineweaver and Burk or of Hofstee, without regard for uptake in earlier phases, indicates absorption rate to be a hyperbolic function of concentration. The observations suggest that glucose uptake is carrier-mediated, and that the transport barrier undergoes a series of all-or-none transformations at critical external concentrations, yielding successive new and higher values for the parameters Km and Vmax 3-O-Methyl glucose, a nonmetabolizable analogue of glucose, shows the same multiphasic absorption isotherm, with Km values essentially similar to those for glucose uptake, and Vmax values somewhat lower than those for glucose absorption. Whereas the first three phases of the absorption isotherm are taken to reflect passage across the plasma membrane, the fourth phase may reflect kinetics of glucose or 3-O-methyl glucose transport to the vacuole. PMID:16658317

  9. A binary phase field crystal study for liquid phase heteroepitaxial growth

    NASA Astrophysics Data System (ADS)

    Lu, Yanli; Peng, Yingying; Chen, Zheng

    2016-09-01

    The liquid phase heteroepitaxial growth on predefined crystalline substrate is studied with binary phase field crystal (PFC) model. The purpose of this paper focuses on changes of the morphology of epitaxial films, influences of substrate vicinal angles on epitaxial growth, characteristics of islands growth on both sides of the substrate as well. It is found that the morphology of epitaxial films undergoes the following transitions: layer-by-layer growth, islands formation, mismatch dislocations nucleation and climb towards the film-substrate interface. Meanwhile, the density of steps and islands has obviously direct ratio relations with the vicinal angles. Also, preferential regions are found when islands grow on both sides of the substrate. For thinner substrate, the arrangement of islands is more orderly and the appearance of preferential growth is more obvious than that of thicker substrate. Also, the existing of preferential regions is much more valid for small substrate vicinal angles in contrast for big substrate vicinal angles.

  10. Laboratory Exercise: Study of Digestive and Regulatory Processes through the Exploration of Fasted and Postprandial Blood Glucose

    ERIC Educational Resources Information Center

    Hopper, Mari K.; Maurer, Luke W.

    2013-01-01

    Digestive physiology laboratory exercises often explore the regulation of enzyme action rather than systems physiology. This laboratory exercise provides a systems approach to digestive and regulatory processes through the exploration of postprandial blood glucose levels. In the present exercise, students enrolled in an undergraduate animal…

  11. The possible relevance of autoxidative glycosylation in glucose mediated alterations of proteins: an in vitro study on myofibrillar proteins.

    PubMed

    Lal, S; Chithra, P; Chandrakasan, G

    1996-01-26

    The present work was carried out to examine the role of glycation and transition metal catalysed autoxidation of sugars in glucose-mediated alterations of myofibrillar proteins. Myofibrils were prepared from rat skeletal muscle and incubated with 1) sugar alone 2) sugar and micromolar concentrations of transition metals (Cu2+ or Fe3+) 3) transition metals alone and the control remained without sugar or transition metals. A significant increase in extent of glycation and decrease in ATPase activity of myofibrils incubated under autoxidative conditions were observed over the other three incubations. Reducing agent 2-mercaptoethanol was highly effective in preventing the alterations induced by glucoxidation, compared to EDTA and aminoguanidine, suggesting the involvement of thiol group oxidation in the reduced function of the protein. Free radical scavengers like catalase, benzoic acid and mannitol were also effective in preventing glucose mediated alterations. Although a high concentration of glucose alone has an insignificant effect on myofibrils in vitro, the results from the present work suggest that glucose in combination with transition metals could lead to functional alterations of myofibrils, and this process by generating free radicals may contribute to the overall complications of diabetes and aging.

  12. Studies of Highly-Ordered Heterodiantennary Mannose/Glucose-Functionalized Polymers and Concanavalin A Protein Interactions Using Isothermal Titration Calorimetry

    PubMed Central

    Nguyen, Hien M.

    2016-01-01

    Preparations of the highly-ordered monoantennary, homofunctional diantennary, and heterofunctional diantennary neoglycopolymers of a-D-mannose and β-D-glucose residues were achieved via ring-opening metathesis polymerization. Isothermal titration calorimetry measurements of these synthetic neoglycopolymers with Concanavalin A, revealed that hetero-functional diantennary architectures bearing both a-mannose and non-binding β-glucose units, poly(Man-Glc), binds to Concanavalin A (Ka = 16.1 × 106 M−1) comparably to homofunctional diantennary neoglycopolymer (Ka = 30 × 106 M−1) bearing only a-mannose unit, poly(Man-Man). In addition, poly(Man-Glc) neoglycopolymer shows a nearly five-fold increasing in binding affinity compared to monoantennary neoglycopolymer, poly(Man). Although the exact mechanism for the high binding affinity of poly(Man-Glc) to Con A is unclear, we hypothesize that the α-mannose bound to Con A might facilitate interaction of β-glucose with the extended binding site of Con A due to the close proximity of β-glucose to α-mannose residues in the designed polymerizable scaffold. PMID:26580410

  13. Study on the effect of sulphur, glucose, nitrogen and plant residues on the immobilization of sulphate-S in soil.

    PubMed

    Shahsavani, S

    2009-02-15

    In order to evaluate the relationship between sulphur (S), glucose (G), nitrogen (N) and plant residues (st), on sulphur immobilization and microbial transformation. Five soil samples from 0-30 cm of Bastam farmer's fields of Shahrood area were collected. Eleven treatments with different levels of S, G, N and plant residues (wheat straw) were applied in a randomized block design with three replications and incubated over 20, 45 and 60 days. The immobilization of SO4(-2)-S presented as a percentage of that added, was inversely related to its addition rate. Additions of glucose and plant residues increased with the C-to-S ratio of the added amendments, irrespective of their origins (glucose and plant residues). In the presence of C sources (glucose or plant residues). N significantly increased the immobilization of SO4(-2)-S, whilst the effect of N was insignificant in the absence of a C amendment. In first few days the amounts of added SO4(-2)-S immobilized were linearly correlated with the amounts of added S recovered in the soil microbial biomass. With further incubation the proportions of immobilized SO4(-2)-S remaining as biomass-S decreased. Decrease in biomass-S was thought to be due to the conversion ofbiomass-S into soil organic-S. Glucose addition increased the immobilization (microbial utilization and incorporation into the soil organic matter) of native soil SO4(-2)-S. However, N addition enhance the mineralization of soil organic-S, increasing the concentration of SO4(-2)-S in soil and the extent to which available-S can be immobilized is determined by both the amount of available-S and the availability of an utilizable C source.

  14. Studies on Phase Shifting Mechanism in Pulse Tube Cryocooler

    NASA Astrophysics Data System (ADS)

    Padmanabhan; Gurudath, C. S.; Srikanth, Thota; Ambirajan, A.; Basavaraj, SA; Dinesh, Kumar; Venkatarathnam, G.

    2017-02-01

    Pulse Tube cryocoolers (PTC) are being used extensively in spacecraft for applications such as sensor cooling due to their simple construction and long life owing to a fully passive cold head. Efforts at ISRO to develop a PTC for space use have resulted in a unit with a cooling capacity of 1W at 80K with an input of 45watts. This paper presents the results of a study with this PTC on the phase shifting characteristics of an Inertance tube in conjunction with a reservoir. The aim was to obtain an optimum phase angle between the mass flow (ṁ) and dynamic pressure (\\tilde p) at the PT cold end that results in the largest possible heat lift from this unit. Theoretical model was developed using Phasor Analysis and Transmission Line Model (TLM) for different mass flow and values of optimum frequency and phase angles were predicted. They were compared with experimental data from the PTC for different configurations of the Inertance tube/reservoir at various frequencies and charge pressures. These studies were carried out to characterise an existing cryocooler and design an optimised phase shifter with the aim of improving the performance with respect to specific power input.

  15. Studies of phase transitions in the aripiprazole solid dosage form.

    PubMed

    Łaszcz, Marta; Witkowska, Anna

    2016-01-05

    Studies of the phase transitions in an active substance contained in a solid dosage form are very complicated but essential, especially if an active substance is classified as a BCS Class IV drug. The purpose of this work was the development of sensitive methods for the detection of the phase transitions in the aripiprazole tablets containing initially its form III. Aripiprazole exhibits polymorphism and pseudopolymorphism. Powder diffraction, Raman spectroscopy and differential scanning calorimetry methods were developed for the detection of the polymorphic transition between forms III and I as well as the phase transition of form III into aripiprazole monohydrate in tablets. The study involved the initial 10 mg and 30 mg tablets, as well as those stored in Al/Al blisters, a triplex blister pack and HDPE bottles (with and without desiccant) under accelerated and long term conditions. The polymorphic transition was not observed in the initial and stored tablets but it was visible on the DSC curve of the Abilify(®) 10 mg reference tablets. The formation of the monohydrate was observed in the diffractograms and Raman spectra in the tablets stored under accelerated conditions. The monohydrate phase was not detected in the tablets stored in the Al/Al blisters under long term conditions. The results showed that the Al/Al blisters can be recommended as the packaging of the aripiprazole tablets containing form III.

  16. Vestibular Function Research (VFR) experiment. Phase B: Design definition study

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The Vestibular Functions Research (VFR) Experiment was established to investigate the neurosensory and related physiological processes believed to be associated with the space flight nausea syndrome and to develop logical means for its prediction, prevention and treatment. The VFR Project consists of ground and spaceflight experimentation using frogs as specimens. The phase B Preliminary Design Study provided for the preliminary design of the experiment hardware, preparation of performance and hardware specification and a Phase C/D development plan, establishment of STS (Space Transportation System) interfaces and mission operations, and the study of a variety of hardware, experiment and mission options. The study consist of three major tasks: (1) mission mode trade-off; (2) conceptual design; and (3) preliminary design.

  17. The Kidney's role in glucose balance following partial hepatectomy.

    PubMed

    Jones, C E; Koshibu, K; DeCambre, M; Gerich, J E; Bessey, P Q; Krusch, D A

    1998-10-01

    It has long been believed that the liver is the major contributor to glucose balance during fasting and stressful situations. Recently, investigators have implicated the kidney as having a significant contribution to systemic glucose appearance. We studied the relative contributions of the kidney and liver to glucose homeostasis in fasted nonoperated, sham-operated, and 70% hepatectomized rats. Systemic glucose appearance, renal glucose release and uptake, and hepatic glucose release were determined by glucose balance and isotopic dilution techniques. Systemic glucose appearance remained unchanged following hepatectomy. There was a significant output of glucose by the kidney in all groups, accounting for >50% of total glucose appearance. Despite the kidney's appreciable contribution to circulating glucose in the postabsorptive state, renal glucose release was not increased in the hepatectomized rats compared to controls. Total glucose appearance was maintained following hepatectomy by an increase in hepatic glucogenesis. There was a significant increase in the rate of hepatic glucose release from resected rats when normalized to gram of remaining liver (P < 0.001). Despite the substantial amount of renal glucose output in the postabsorptive state, preservation of glucose balance following 70% hepatectomy is accomplished by adaptation in hepatic glucose output.

  18. Stigma and Its Impact on Glucose Control Among Youth With Diabetes: Protocol for a Canada-Wide Study

    PubMed Central

    Brazeau, Anne-Sophie; Nakhla, Meranda; Wright, Michael; Panagiotopoulos, Constadina; Pacaud, Daniele; Henderson, Mélanie; Rahme, Elham; Da Costa, Deborah

    2016-01-01

    Background Stigma in chronic disease involves unwarranted rejection, judgement, or exclusion by others based on the chronic disease itself. Objective We aim to determine the prevalence of stigma among youth and young adults with type 1 diabetes in Canada, to assess associations between stigma and glycemic control, and to explore ways to address stigma related to type 1 diabetes. Methods The study includes 3 distinct phases: (1) refinement of survey questions, (2) assessment of test-retest reliability, and (3) a data collection and analysis phase (online survey and mailed-in capillary blood sample to assess hemoglobin A1c). A total of 380 youth and young adults (14 to 24 years old) with type 1 diabetes are being recruited through social media and clinic posters. Results Phases 1 and 2 are complete, and phase 3 is in progress. Thirty participants completed phase 2. The survey includes the Barriers to Diabetes Adherence in adolescent scale (intraclass correlation [ICC]=0.967, 95% CI 0.931-0.984), the Self-Efficacy for Diabetes Self-Management measure (ICC=0.952, 95% CI 0.899-0.977), the World Health Organization-5 Well-Being Index (ICC=0.860, 95% CI 0.705-0.933), 12 closed-ended questions, and an additional 5 open-ended questions to explore challenges and solutions developed by the team of experts, including a patient representative. Conclusions This will be the first large-scale survey to estimate the prevalence of stigma in young people with type 1 diabetes. The results of this study will allow for an appreciation of the magnitude of the problem and the need for developing and implementing solutions. This work is intended to provide an initial understanding of youth perspectives on the challenges of living with type 1 diabetes and will serve as a foundation for future research and action to help youth improve their experience of living with diabetes. Trial Registration ClinicalTrials.gov NCT02796248, https://clinicaltrials.gov/ct2/show/NCT02796248 (Archived at http

  19. Orbit transfer vehicle engine study. Phase A: Continuation (study results)

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Studies included: selection of boost pump designs for low NPSH operation and generation of associated programmatic data; evaluation of OTV engine operation at intermediate thrust levels and impact on programmatics; and assessments of OTV engine operation at idle-mode thrusts under conditions experienced during aerobraking maneuvers of the ABOTV. As a result of the studies, it was recommended that the original OTV boost pump designs be used without change for low NPSH operation. Intermediate thrust operation is feasible for both the expander cycle and staged combustion cycles.

  20. 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. Following your health ...

  1. Blood Glucose Monitoring Devices

    MedlinePlus

    ... the Bar for Blood Glucose Meter Performance Recalls & Alerts Shasta Technologies GenStrip Blood Glucose Test Strips May ... Latest Recalls Report an Adverse Event MedWatch Safety Alerts News Releases Consumer Updates About FDA Contact FDA ...

  2. Use of a two-stage insulin infusion study to assess the relationship between insulin suppression of lipolysis and insulin-mediated glucose uptake in overweight/obese, nondiabetic women.

    PubMed

    McLaughlin, Tracey; Yee, Gail; Glassford, Alec; Lamendola, Cindy; Reaven, Gerald

    2011-12-01

    Differences in insulin regulation of free fatty acids (FFAs) are not readily apparent at the same insulin concentrations used to differentiate relative insulin-mediated glucose disposal. Resistance to insulin-mediated glucose disposal and higher daylong FFA concentrations occur more commonly in obese individuals. However, the relationship between the ability of insulin to suppress FFA release from adipose tissue and stimulate glucose disposal in muscle has not been clearly defined in this population. The current study was initiated to test the hypothesis that these 2 facets of insulin action are related, with greater defects in insulin-mediated glucose disposal associated with less effective insulin inhibition of FFA release from adipose tissue. Subjects included 56 healthy nondiabetic overweight/moderately obese women classified as insulin resistant or insulin sensitive based on whole-body glucose disposal. All underwent a modified 240-minute 2-stage insulin infusion with basal (∼15 µU/mL) and physiologically elevated (∼80 µU/mL) steady-state insulin concentrations. Plasma glucose, insulin, FFA, and glycerol were measured throughout. Whereas plasma glucose differed most during physiological hyperinsulinemia in insulin-resistant vs insulin-sensitive subjects, plasma FFA/glycerol differed most during basal insulin concentrations. The FFA concentrations during the basal insulin steady state correlated highly (r = 0.85, P < .001) with glucose concentrations during the hyperinsulinemic steady state. Overweight/moderately obese women exhibit dramatic differences in the ability of insulin to suppress plasma FFA, which correlate highly with differences in insulin-mediated glucose disposal. Variability in insulin regulation of FFA is most apparent at basal insulin concentrations, whereas differences in glucose disposal are most apparent during physiologic hyperinsulinemia. Both can be quantified using a simple 2-stage insulin infusion study, with first-stage FFA

  3. Thiazolidinediones increase hepatic insulin extraction in African Americans with impaired glucose tolerance and type 2 diabetes mellitus. A pilot study of rosiglitazone.

    PubMed

    Osei, Kwame; Gaillard, Trudy; Schuster, Dara

    2007-01-01

    Peripheral insulin levels are determined by beta-cell secretion, insulin sensitivity, and hepatic insulin extraction (HIE). We have previously shown that whereas sulfonylureas reduce insulin extraction, metformin enhances HIE. However, the effects of thiazolidinediones (TZDs) on HIE remain uncertain. Thus, we investigated the potential contribution of hepatic insulin clearance to peripheral insulin levels during rosiglitazone therapy in African Americans with impaired glucose tolerance (IGT) and type 2 diabetes mellitus (DM). The study was composed of 12 first-degree relatives with IGT and 17 patients with newly diagnosed type 2 DM. Nineteen healthy relatives with normal glucose tolerance served as controls. Serum glucose, insulin, and C-peptide, and HIE (C-peptide-insulin molar ratios) were measured at t = 0 and 120 minutes during oral glucose tolerance test (OGTT) in all the subjects. The OGTT was performed before and after 3 months of rosiglitazone therapy (4 mg/d x 4 weeks and >8 mg/d x 8 weeks) in patients with IGT and type 2 DM. Insulin resistance index and beta-cell function were calculated in each subject using homeostasis model assessment (HOMA). Rosiglitazone therapy improved but did not normalize the overall glycemic control in the IGT and type 2 DM groups. After rosiglitazone therapy, the mean serum insulin and C-peptide levels at fasting remained unchanged. However, the 2-hour serum glucose and insulin were lower, whereas serum C-peptide was unchanged during 3 months of rosiglitazone treatment. Mean insulin resistance index of HOMA was reduced by 30% (4.12 +/- 1.95 vs 6.33 +/- 3.54, P < .05) in the type 2 DM group and by 21% (3.78 +/- 2.45 vs 4.81 +/- 3.49, P = NS) in the IGT group. Mean HIE values were significantly lower (70%) in the type 2 DM and IGT groups when compared with the normal glucose tolerance group. At 3 months, basal HIE was not significantly changed by rosiglitazone therapy in IGT and type 2 DM groups when compared with the baseline (0

  4. The Western Wind and Solar Integration Study Phase 2

    SciTech Connect

    Lew, D.; Brinkman, G.; Ibanez, E.; Hodge, B. M.; Hummon, M.; Florita, A.; Heaney, M.

    2013-09-01

    The electric grid is a highly complex, interconnected machine, and changing one part of the grid can have consequences elsewhere. Adding wind and solar affects the operation of the other power plants and adding high penetrations can induce cycling of fossil-fueled generators. Cycling leads to wear-and-tear costs and changes in emissions. Phase 2 of the Western Wind and Solar Integration Study (WWSIS-2) evaluated these costs and emissions and simulated grid operations for a year to investigate the detailed impact of wind and solar on the fossil-fueled fleet. This built on Phase 1, one of the largest wind and solar integration studies ever conducted, which examined operational impacts of high wind and solar penetrations in the West.

  5. The Western Wind and Solar Integration Study Phase 2

    SciTech Connect

    Lew, Debra; Brinkman, Greg; Ibanez, E.; Florita, A.; Heaney, M.; Hodge, B. -M.; Hummon, M.; Stark, G.; King, J.; Lefton, S. A.; Kumar, N.; Agan, D.; Jordan, G.; Venkataraman, S.

    2013-09-01

    The electric grid is a highly complex, interconnected machine, and changing one part of the grid can have consequences elsewhere. Adding wind and solar affects the operation of the other power plants and adding high penetrations can induce cycling of fossil-fueled generators. Cycling leads to wear-and-tear costs and changes in emissions. Phase 2 of the Western Wind and Solar Integration Study (WWSIS-2) evaluated these costs and emissions and simulated grid operations for a year to investigate the detailed impact of wind and solar on the fossil-fueled fleet. This built on Phase 1, one of the largest wind and solar integration studies ever conducted, which examined operational impacts of high wind and solar penetrations in the West(GE Energy 2010).

  6. Studies in Solid Phase Peptide Synthesis: A Personal Perspective

    SciTech Connect

    Mitchell, A R

    2007-06-01

    By the early 1970s it had became apparent that the solid phase synthesis of ribonuclease A could not be generalized. Consequently, virtually every aspect of solid phase peptide synthesis (SPPS) was reexamined and improved during the decade of the 1970s. The sensitive detection and elimination of possible side reactions (amino acid insertion, N{sup {alpha}}-trifluoroacetylation, N{sup {alpha}{var_epsilon}}-alkylation) was examined. The quantitation of coupling efficiency in SPPS as a function of chain length was studied. A new and improved support for SPPS, the 'PAM-resin', was prepared and evaluated. These and many other studies from the Merrifield laboratory and elsewhere increased the general acceptance of SPPS leading to the 1984 Nobel Prize in Chemistry for Bruce Merrifield.

  7. All about Blood Glucose

    MedlinePlus

    Toolkit No. 15 All About Blood Glucose Keeping your blood glucose (sugar)in your target range can prevent or delay the health problems ... Diabetes Association, Inc. 1/15 Toolkit No.15: All About Blood Glucose continued team about when and ...

  8. The sodium glucose cotransporter 2 inhibitor empagliflozin does not prolong QT interval in a thorough QT (TQT) study

    PubMed Central

    2013-01-01

    Background Empagliflozin is a potent, selective sodium glucose cotransporter 2 (SGLT2) inhibitor in development as an oral antidiabetic treatment. This QT interval study assessed potential effects of empagliflozin on ventricular repolarisation and other electrocardiogram (ECG) parameters. Methods A randomised, placebo-controlled, single-dose, double-blind, five-period crossover study incorporating a novel double-placebo period design to reduce sample size, while maintaining full statistical power. Treatments: single empagliflozin doses of 25 mg (therapeutic) and 200 mg (supratherapeutic), matching placebo and open-label moxifloxacin 400 mg (positive control). Triplicate 12-lead ECGs of 10 second duration were recorded at baseline and during the first 24 hours after dosing. The primary endpoint was mean change from baseline (MCfB) in the population heart rate-corrected QT interval (QTcN) between 1–4 hours after dosing. Results Thirty volunteers (16 male, 14 female, mean [range] age: 34.5 [18–52] years) were randomised. The placebo-corrected MCfB in QTcN 1–4 hours after dosing was 0.6 (90% CI: -0.7, 1.9) ms and -0.2 (-1.4, 0.9) ms for empagliflozin 25 mg and 200 mg, respectively, below the ICH E14 defined threshold of regulatory concern 10 ms. Assay sensitivity was confirmed by a placebo-corrected MCfB in QTcN 2–4 hours post-dose of 12.4 (10.7, 14.1) ms with moxifloxacin 400 mg. Empagliflozin tolerability was good for all volunteers; 23.3% experienced adverse events (AEs) with empagliflozin and 27.6% with placebo. The most frequent AE was nasopharyngitis. Conclusions/interpretation Single doses of empagliflozin 25 mg and 200 mg were not associated with QTcN prolongation and were well tolerated in healthy volunteers. Trial registration ClinicalTrials.gov: NCT01195675 PMID:23617452

  9. Toxicity Evaluation of Engineered Nanomaterials (Phase 1 Studies)

    DTIC Science & Technology

    2012-01-01

    alleviate conditions involving toxic levels of metallic ions such as Wilson’s disease .33,34 In this case, Dynasore’ s polyphenolic structure...AFRL-RH-WP-TR-2013-0078 Toxicity Evaluation of Engineered Nanomaterials (Phase I Studies) Saber Hussain Bioeffects Division...REPORT TYPE Final Tech Report 3. DATES COVERED (From - To) 1-21-2009 to 12-31-2011 4. TITLE AND SUBTITLE Toxicity Evaluation of Engineered

  10. Study of large nonlinear change phase in Hibiscus Sabdariffa

    NASA Astrophysics Data System (ADS)

    Trejo-Durán, M.; Alvarado-Méndez, E.; Andrade-Lucio, J. A.; Rojas-Laguna, R.; Vázquez-Guevara, M. A.

    2015-09-01

    High intensities electromagnetic energy interacting with organic media gives rise to nonlinear optical effects. Hibiscus Sabdariffa is a flower whose concentrated solution presents interesting nonlinear optical properties. This organic material shows an important self-phase modulation with changes bigger than 2π. We present a diffraction ring patterns study of the Hibiscus Sabdariffa solution. Numerical results of transmittance, with refraction and simultaneous absorption, are shown.

  11. Correspondence of continuous interstitial glucose measurement against arterialised and capillary glucose following an oral glucose tolerance test in healthy volunteers.

    PubMed

    Dye, Louise; Mansfield, Michael; Lasikiewicz, Nicola; Mahawish, Lena; Schnell, Rainer; Talbot, Duncan; Chauhan, Hitesh; Croden, Fiona; Lawton, Clare

    2010-01-01

    The aim of the present study was to validate the Glucoday continuous interstitial ambulatory glucose-monitoring device (AGD) against plasma glucose measured from arterialised venous (AV) and glucose from capillary whole blood (finger prick, FP) in non-diabetic subjects in response to an oral glucose tolerance test. Fifteen healthy overweight men (age 30-49 years, BMI 26-31 kg/m2) participated. Glucose levels were measured before, during and after consumption of an oral 75 g glucose load using twelve FP samples and forty-four 1 ml AV blood samples during 180 min. Interstitial glucose was measured via the AGD. Three venous samples for fasting insulin were taken to estimate insulin resistance. Profiles of AGD, AV and FP glucose were generated for each participant. Glucose values for each minute of the measurement period were interpolated using a locally weighted scatterplot smoother. Data were compared using Bland-Altman plots that showed good correspondence between all pairs of measurements. Concordance between the three methods was 0.8771 (Kendall's W, n 15, P < 0.001). Concordance was greater between AV and FP (W = 0.9696) than AGD and AV (W = 0.8770) or AGD and FP (W = 0.8764). Analysis of time to peak glucose indicated that AGD measures lagged approximately 15 min behind FP and AV measures. Percent body fat was significantly correlated with time to peak glucose levels for each measure, while BMI and estimated insulin resistance (homeostatic model assessment, HOMA) were not. In conclusion, AGD shows good correspondence with FP and AV glucose measures in response to a glucose load with a 15 min time lag. Taking this into account, AGD has potential application in nutrition and behaviour studies.

  12. Ambulatory glucose profile: Flash glucose monitoring.

    PubMed

    Kalra, Sanjay; Gupta, Yashdeep

    2015-12-01

    Ambulatory glucose profile (AGP) is a novel way of assessing glycaemic levels on a 24 hour basis, through a minimally invasive method, known as flash glucose monitoring. This review describes the unique features of AGP, differentiates it from existing methods of glucose monitoring, and explains how it helps pursue the glycaemic pentad. The review suggests pragmatic usage of this technology, including pre-test, intra-test, and post-test counselling, and lists specific clinical scenarios where the investigation seems to be of immense benefit.

  13. In vitro studies on radiosensitization effect of glucose capped gold nanoparticles in photon and ion irradiation of HeLa cells

    NASA Astrophysics Data System (ADS)

    Kaur, Harminder; Pujari, Geetanjali; Semwal, Manoj K.; Sarma, Asitikantha; Avasthi, Devesh Kumar

    2013-04-01

    Noble metal nanoparticles are of great interest due to their potential applications in diagnostics and therapeutics. In the present work, we synthesized glucose capped gold nanoparticle (Glu-AuNP) for internalization in the HeLa cell line (human cervix cancer cells). The capping of glucose on Au nanoparticle was confirmed by Raman spectroscopy. The Glu-AuNP did not show any toxicity to the HeLa cell. The γ-radiation and carbon ion irradiation of HeLa cell with and without Glu-AuNP were performed to evaluate radiosensitization effects. The study revealed a significant reduction in radiation dose for killing the HeLa cells with internalized Glu-AuNPs as compared to the HeLa cells without Glu-AuNP. The Glu-AuNP treatment resulted in enhancement of radiation effect as evident from increase in relative biological effectiveness (RBE) values for carbon ion irradiated HeLa cells.

  14. Availability of phosphate for phytoplankton and bacteria and of glucose for bacteria at different pCO2 levels in a mesocosm study

    NASA Astrophysics Data System (ADS)

    Tanaka, T.; Thingstad, T. F.; Løvdal, T.; Grossart, H.-P.; Larsen, A.; Allgaier, M.; Meyerhöfer, M.; Schulz, K. G.; Wohlers, J.; Zöllner, E.; Riebesell, U.

    2008-05-01

    Availability of phosphate for phytoplankton and bacteria and of glucose for bacteria at different pCO2 levels were studied in a mesocosm experiment (PeECE III). Using nutrient-depleted SW Norwegian fjord waters, three different levels of pCO2 (350 μatm: 1×CO2; 700 μatm: 2×CO2; 1050 μatm: 3×CO2) were set up, and nitrate and phosphate were added at the start of the experiment in order to induce a phytoplankton bloom. Despite similar responses of total particulate P concentration and phosphate turnover time at the three different pCO2 levels, the size distribution of particulate P and 33PO4 uptake suggested that phosphate transferred to the >10 μm fraction was greater in the 3×CO2 mesocosm during the first 6-10 days when phosphate concentration was high. During the period of phosphate depletion (after Day 12), specific phosphate affinity and specific alkaline phosphatase activity (APA) suggested a P-deficiency (i.e. suboptimal phosphate supply) rather than a P-limitation for the phytoplankton and bacterial community at the three different pCO2 levels. Specific phosphate affinity and specific APA tended to be higher in the 3×CO2 than in the 2×CO2 and 1×CO2 mesocosms during the phosphate depletion period, although no statistical differences were found. Glucose turnover time was correlated significantly and negatively with bacterial abundance and production but not with the bulk DOC concentration. This suggests that even though constituting a small fraction of the bulk DOC, glucose was an important component of labile DOC for bacteria. Specific glucose affinity of bacteria behaved similarly at the three different pCO2 levels with measured specific glucose affinities being consistently much lower than the theoretical maximum predicted from the diffusion-limited model. This suggests that bacterial growth was not severely limited by the glucose availability. Hence, it seems that the lower availability of inorganic nutrients after the phytoplankton bloom reduced

  15. [Advances of the mechanism study on berberine in the control of blood glucose and lipid as well as metabolism disorders].

    PubMed

    Shen, Ning; Li, Cai-Na; Huan, Yi; Shen, Zhu-Fang

    2010-06-01

    Berberine, an isoquinoline alkaloid isolated from some Chinese medicinal herbs such as Coptidis rhizoma, has been used for the treatment of diarrhea and other gastrointestinal infections as an antibacterial drug in Chinese medicine. In recent years, it was reported to have beneficial effects on the metabolism disorders states of diabetes. The mechanisms involve many aspects of the diabetes, including regulating the blood cholesterol and triglyceride, lowering blood glucose, ameliorating the insulin resistant state and influencing the function of the pancreatic beta cell.

  16. 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.

  17. Critical assessment of the Quartz Crystal Microbalance with Dissipation as an analytical tool for biosensor development and fundamental studies: Metallophthalocyanine-glucose oxidase biocomposite sensors.

    PubMed

    Fogel, R; Mashazi, P; Nyokong, T; Limson, J

    2007-08-30

    One of the challenges in electrochemical biosensor design is gaining a fundamental knowledge of the processes underlying immobilisation of the molecules onto the electrode surface. This is of particular importance in biocomposite sensors where concerns have arisen as to the nature of the interaction between the biological and synthetic molecules immobilised. We examined the use of the Quartz Crystal Microbalance with Dissipation (QCM-D) as a tool for fundamental analyses of a model sensor constructed by the immobilisation of cobalt(II) phthalocyanine (TCACoPc) and glucose oxidase (GOx) onto a gold-quartz electrode (electrode surface) for the enhanced detection of glucose. The model sensor was constructed in aqueous phase and covalently linked the gold surface to the TCACoPc, and the TCACoPc to the GOx, using the QCM-D. The aqueous metallophthalocyanine (MPc) formed a multi-layer over the surface of the electrode, which could be removed to leave a monolayer with a mass loading that compared favourably to the theoretical value expected. Analysis of frequency and dissipation plots indicated covalent attachment of glucose oxidase onto the metallophthalocyanine layer. The amount of GOx bound using the model system compared favourably to calculations derived from the maximal amperometric functioning of the electrochemical sensor (examined in previously-published literature, Mashazi, P.N., Ozoemena, K.I., Nyokong, T., 2006. Electrochim. Acta 52, 177-186), but not to theoretical values derived from dimensions of GOx as established by crystallography. The strength of the binding of the GOx film with the TCACoPc layer was tested by using 2% SDS as a denaturant/surfactant, and the GOx film was not found to be significantly affected by exposure to this. This paper thus showed that QCM-D can be used in order to model essential processes and interactions that dictate the functional parameters of a biosensor.

  18. EXPERIMENTAL RESULTS OF THE NEPHELINE PHASE III STUDY

    SciTech Connect

    Fox, K.; Edwards, T.

    2009-11-09

    This study is the third phase in a series of experiments designed to reduce conservatism in the model that predicts the formation of nepheline, a crystalline phase that can reduce the durability of high level waste glass. A Phase I study developed a series of glass compositions that were very durable while their nepheline discriminator values were well below the current nepheline discriminator limit of 0.62, where nepheline is predicted to crystallize upon slow cooling. A Phase II study selected glass compositions to identify any linear effects of composition on nepheline crystallization and that were restricted to regions that fell within the validation ranges of the Defense Waste Processing Facility (DWPF) Product Composition Control System (PCCS) models. However, it was not possible to identify any linear effects of composition on chemical durability performance for this set of study glasses. The results of the Phase II study alone were not sufficient to recommend modification of the current nepheline discriminator. It was recommended that the next series of experiments continue to focus not only on compositional regions where the PCCS models are considered applicable (i.e., the model validation ranges), but also be restricted to compositional regions where the only constraint limiting processing is the current nepheline discriminator. Two methods were used in selecting glasses for this Phase III nepheline study. The first was based on the relationship of the current nepheline discriminator model to the other DWPF PCCS models, and the second was based on theory of crystallization in mineral and glass melts. A series of 29 test glass compositions was selected for this study using a combination of the two approaches. The glasses were fabricated and characterized in the laboratory. After reviewing the data, the study glasses generally met the target compositions with little issue. Product Consistency Test results correlated well with the crystallization analyses in

  19. Glucose Metabolic Changes in the Brain and Muscles of Patients with Nonspecific Neck Pain Treated by Spinal Manipulation Therapy: A [18F]FDG PET Study

    PubMed Central

    Inami, Akie; Ogura, Takeshi; Watanuki, Shoichi; Masud, Md. Mehedi; Shibuya, Katsuhiko; Miyake, Masayasu; Matsuda, Rin; Hiraoka, Kotaro; Itoh, Masatoshi; Fuhr, Arlan W.; Yanai, Kazuhiko

    2017-01-01

    Objective. The aim of this study was to investigate changes in brain and muscle glucose metabolism that are not yet known, using positron emission tomography with [18F]fluorodeoxyglucose ([18F]FDG PET). Methods. Twenty-one male volunteers were recruited for the present study. [18F]FDG PET scanning was performed twice on each subject: once after the spinal manipulation therapy (SMT) intervention (treatment condition) and once after resting (control condition). We performed the SMT intervention using an adjustment device. Glucose metabolism of the brain and skeletal muscles was measured and compared between the two conditions. In addition, we measured salivary amylase level as an index of autonomic nervous system (ANS) activity, as well as muscle tension and subjective pain intensity in each subject. Results. Changes in brain activity after SMT included activation of the dorsal anterior cingulate cortex, cerebellar vermis, and somatosensory association cortex and deactivation of the prefrontal cortex and temporal sites. Glucose uptake in skeletal muscles showed a trend toward decreased metabolism after SMT, although the difference was not significant. Other measurements indicated relaxation of cervical muscle tension, decrease in salivary amylase level (suppression of sympathetic nerve activity), and pain relief after SMT. Conclusion. Brain processing after SMT may lead to physiological relaxation via a decrease in sympathetic nerve activity. PMID:28167971

  20. Determinants of Cofactor Specificity for the Glucose-6-Phosphate Dehydrogenase from Escherichia coli: Simulation, Kinetics and Evolutionary Studies

    PubMed Central

    Fuentealba, Matias; Muñoz, Rodrigo; Maturana, Pablo; Krapp, Adriana; Cabrera, Ricardo

    2016-01-01

    Glucose 6-Phosphate Dehydrogenases (G6PDHs) from different sources show varying specificities towards NAD+ and NADP+ as cofactors. However, it is not known to what extent structural determinants of cofactor preference are conserved in the G6PDH family. In this work, molecular simulations, kinetic characterization of site-directed mutants and phylogenetic analyses were used to study the structural basis for the strong preference towards NADP+ shown by the G6PDH from Escherichia coli. Molecular Dynamics trajectories of homology models showed a highly favorable binding energy for residues K18 and R50 when interacting with the 2'-phosphate of NADP+, but the same residues formed no observable interactions in the case of NAD+. Alanine mutants of both residues were kinetically characterized and analyzed with respect to the binding energy of the transition state, according to the kcat/KM value determined for each cofactor. Whereas both residues contribute to the binding energy of NADP+, only R50 makes a contribution (about -1 kcal/mol) to NAD+ binding. In the absence of both positive charges the enzyme was unable to discriminate NADP+ from NAD+. Although kinetic data is sparse, the observed distribution of cofactor preferences within the phylogenetic tree is sufficient to rule out the possibility that the known NADP+-specific G6PDHs form a monophyletic group. While the β1-α1 loop shows no strict conservation of K18, (rather, S and T seem to be more frequent), in the case of the β2-α2 loop, different degrees of conservation are observed for R50. Noteworthy is the fact that a K18T mutant is indistinguishable from K18A in terms of cofactor preference. We conclude that the structural determinants for the strict discrimination against NAD+ in the case of the NADP+-specific enzymes have evolved independently through different means during the evolution of the G6PDH family. We further suggest that other regions in the cofactor binding pocket, besides the β1-α1 and β2-α2

  1. Determinants of Cofactor Specificity for the Glucose-6-Phosphate Dehydrogenase from Escherichia coli: Simulation, Kinetics and Evolutionary Studies.

    PubMed

    Fuentealba, Matias; Muñoz, Rodrigo; Maturana, Pablo; Krapp, Adriana; Cabrera, Ricardo

    2016-01-01

    Glucose 6-Phosphate Dehydrogenases (G6PDHs) from different sources show varying specificities towards NAD+ and NADP+ as cofactors. However, it is not known to what extent structural determinants of cofactor preference are conserved in the G6PDH family. In this work, molecular simulations, kinetic characterization of site-directed mutants and phylogenetic analyses were used to study the structural basis for the strong preference towards NADP+ shown by the G6PDH from Escherichia coli. Molecular Dynamics trajectories of homology models showed a highly favorable binding energy for residues K18 and R50 when interacting with the 2'-phosphate of NADP+, but the same residues formed no observable interactions in the case of NAD+. Alanine mutants of both residues were kinetically characterized and analyzed with respect to the binding energy of the transition state, according to the kcat/KM value determined for each cofactor. Whereas both residues contribute to the binding energy of NADP+, only R50 makes a contribution (about -1 kcal/mol) to NAD+ binding. In the absence of both positive charges the enzyme was unable to discriminate NADP+ from NAD+. Although kinetic data is sparse, the observed distribution of cofactor preferences within the phylogenetic tree is sufficient to rule out the possibility that the known NADP+-specific G6PDHs form a monophyletic group. While the β1-α1 loop shows no strict conservation of K18, (rather, S and T seem to be more frequent), in the case of the β2-α2 loop, different degrees of conservation are observed for R50. Noteworthy is the fact that a K18T mutant is indistinguishable from K18A in terms of cofactor preference. We conclude that the structural determinants for the strict discrimination against NAD+ in the case of the NADP+-specific enzymes have evolved independently through different means during the evolution of the G6PDH family. We further suggest that other regions in the cofactor binding pocket, besides the β1-α1 and β2-α2

  2. Glucose screening tests during pregnancy

    MedlinePlus

    Oral glucose tolerance test - pregnancy; OGTT - pregnancy; Glucose challenge test - pregnancy; Gestational diabetes - glucose screening ... first step, you will have a glucose screening test: You DO NOT need to prepare or change ...

  3. Clinical study in phase- contrast mammography: image-quality analysis.

    PubMed

    Longo, Renata; Tonutti, Maura; Rigon, Luigi; Arfelli, Fulvia; Dreossi, Diego; Quai, Elisa; Zanconati, Fabrizio; Castelli, Edoardo; Tromba, Giuliana; Cova, Maria A

    2014-03-06

    The first clinical study of phase-contrast mammography (PCM) with synchrotron radiation was carried out at the Synchrotron Radiation for Medical Physics beamline of the Elettra synchrotron radiation facility in Trieste (Italy) in 2006-2009. The study involved 71 patients with unresolved breast abnormalities after conventional digital mammography and ultrasonography exams carried out at the Radiology Department of Trieste University Hospital. These cases were referred for mammography at the synchrotron radiation facility, with images acquired using a propagation-based phase-contrast imaging technique. To investigate the contribution of phase-contrast effects to the image quality, two experienced radiologists specialized in mammography assessed the visibility of breast abnormalities and of breast glandular structures. The images acquired at the hospital and at the synchrotron radiation facility were compared and graded according to a relative seven-grade visual scoring system. The statistical analysis highlighted that PCM with synchrotron radiation depicts normal structures and abnormal findings with higher image quality with respect to conventional digital mammography.

  4. Dynamic Studies of Lung Fluid Clearance with Phase Contrast Imaging

    SciTech Connect

    Kitchen, Marcus J.; Williams, Ivan; Irvine, Sarah C.; Morgan, Michael J.; Paganin, David M.; Lewis, Rob A.; Pavlov, Konstantin; Hooper, Stuart B.; Wallace, Megan J.; Siu, Karen K. W.; Yagi, Naoto; Uesugi, Kentaro

    2007-01-19

    Clearance of liquid from the airways at birth is a poorly understood process, partly due to the difficulties of observing and measuring the distribution of air within the lung. Imaging dynamic processes within the lung in vivo with high contrast and spatial resolution is therefore a major challenge. However, phase contrast X-ray imaging is able to exploit inhaled air as a contrast agent, rendering the lungs of small animals visible due to the large changes in the refractive index at air/tissue interfaces. In concert with the high spatial resolution afforded by X-ray imaging systems (<100 {mu}m), propagation-based phase contrast imaging is ideal for studying lung development. To this end we have utilized intense, monochromatic synchrotron radiation, together with a fast readout CCD camera, to study fluid clearance from the lungs of rabbit pups at birth. Local rates of fluid clearance have been measured from the dynamic sequences using a single image phase retrieval algorithm.

  5. Orienteering performance and ingestion of glucose and glucose polymers.

    PubMed

    Kujala, U M; Heinonen, O J; Kvist, M; Kärkkäinen, O P; Marniemi, J; Niittymäki, K; Havas, E

    1989-06-01

    The benefit of glucose polymer ingestion in addition to 2.5 per cent glucose before and during a prolonged orienteering competition was studied. The final time in the competition in the group ingesting 2.5 per cent glucose (group G, n = 10) was 113 min 37 s +/- 8 min 11 s, and in the group which had additionally ingested glucose polymer (group G + GP, n = 8) 107 min 18s +/- 4 min 41 s (NS). One fifth (21 per cent) of the time difference between the two groups was due to difference in orienteering errors. Group G + GP orienteered the last third of the competition faster than group G (p less than 0.05). The time ratio between the last third of the competition and the first third of the competition was lower in group G + GP than in group G (p less than 0.05). After the competition, there was statistically insignificant tendency to higher serum glucose and lower serum free fatty acid concentrations in group G + GP, and serum insulin concentration was higher in group G + GP than in group G (p less than 0.05). Three subjects reported that they exhausted during the competition. These same three subjects had the lowest serum glucose concentrations after the competition (2.9 mmol.1(-1), 2.9 mmol.1(-1), 3.5 mmol.1(-1] and all of them were from group G. It is concluded that glucose polymer syrup ingestion is beneficial for prolonged psychophysical performance.

  6. Spectroscopic studies of cold, gas-phase biomolecular ions

    NASA Astrophysics Data System (ADS)

    Rizzo, Thomas R.; Stearns, Jaime A.; Boyarkin, Oleg V.

    While the marriage of mass spectrometry and laser spectroscopy is not new, developments over the last few years in this relationship have opened up new horizons for the spectroscopic study of biological molecules. The combination of electrospray ionisation for producing large biological molecules in the gas phase together with cooled ion traps and multiple-resonance laser schemes are allowing spectroscopic investigation of individual conformations of peptides with more than a dozen amino acids. Highly resolved infrared spectra of single conformations of such species provide important benchmarks for testing the accuracy of theoretical calculations. This review presents a number of techniques employed in our laboratory and in others for measuring the spectroscopy of cold, gas-phase protonated peptides. We show examples that demonstrate the power of these techniques and evaluate their extension to still larger biological molecules.

  7. Adaptive multibeam antennas for spacelab. Phase A: Feasibility study

    NASA Technical Reports Server (NTRS)

    Allen, C. C.; Applebaum, S. P.; Popowsky, W. J.; Wouch, G.

    1976-01-01

    The feasibility was studied of using adaptive multibeam multi-frequency antennas on the spacelab, and to define the experiment configuration and program plan needed for a demonstration to prove the concept. Three applications missions were selected, and requirements were defined for an L band communications experiment, an L band radiometer experiment, and a Ku band communications experiment. Reflector, passive lens, and phased array antenna systems were considered, and the Adaptive Multibeam Phased Array (AMPA) was chosen. Array configuration and beamforming network tradeoffs resulted in a single 3m x 3m L band array with 576 elements for high radiometer beam efficiency. Separate 0.4m x 0.4 m arrays are used to transmit and receive at Ku band with either 576 elements or thinned apertures. Each array has two independently steerable 5 deg beams, which are adaptively controlled.

  8. Effects of Exercise Intensity on Postprandial Improvement in Glucose Disposal and Insulin Sensitivity in Prediabetic Adults

    PubMed Central

    Rynders, Corey A.; Weltman, Judy Y.; Jiang, Boyi; Breton, Marc; Patrie, James; Barrett, Eugene J.

    2014-01-01

    Background: A single bout of exercise improves postprandial glycemia and insulin sensitivity in prediabetic patients; however, the impact of exercise intensity is not well understood. The present study compared the effects of acute isocaloric moderate (MIE) and high-intensity (HIE) exercise on glucose disposal and insulin sensitivity in prediabetic adults. Methods: Subjects (n = 18; age 49 ± 14 y; fasting glucose 105 ± 11 mg/dL; 2 h glucose 170 ± 32 mg/dL) completed a peak O2 consumption/lactate threshold (LT) protocol plus three randomly assigned conditions: 1) control, 1 hour of seated rest, 2) MIE (at LT), and 3) HIE (75% of difference between LT and peak O2 consumption). One hour after exercise, subjects received an oral glucose tolerance test (OGTT). Plasma glucose, insulin, and C-peptide concentrations were sampled at 5- to 10-minute intervals at baseline, during exercise, after exercise, and for 3 hours after glucose ingestion. Total, early-phase, and late-phase area under the glucose and insulin response curves were compared between conditions. Indices of insulin sensitivity (SI) were derived from OGTT data using the oral minimal model. Results: Compared with control, SI improved by 51% (P = .02) and 85% (P < .001) on the MIE and HIE days, respectively. No differences in SI were observed between the exercise conditions (P = .62). Improvements in SI corresponded to significant reductions in the glucose, insulin, and C-peptide area under the curve values during the late phase of the OGTT after HIE (P < .05), with only a trend for reductions after MIE. Conclusion: These results suggest that in prediabetic adults, acute exercise has an immediate and intensity-dependent effect on improving postprandial glycemia and insulin sensitivity. PMID:24243632

  9. New numerical method to study phase transitions and its applications

    SciTech Connect

    Lee, Jooyoung; Kosterlitz, J.M.

    1991-11-01

    We present a powerful method of identifying the nature of transitions by numerical simulation of finite systems. By studying the finite size scaling properties of free energy barrier between competing states, we can identify unambiguously a weak first order transition even when accessible system sizes are L/{xi} < 0.05 as in the five state Potts model in two dimensions. When studying a continuous phase transition we obtain quite accurate estimates of critical exponents by treating it as a field driven first order transition. The method has been successfully applied to various systems.

  10. The Effects of 3 Weeks of Uphill and Downhill Walking on Blood Lipids and Glucose Metabolism in Pre-Diabetic Men: A Pilot Study

    PubMed Central

    Philippe, Marc; Gatterer, Hannes; Eder, Erika Maria; Dzien, Alexander; Somavilla, Matthias; Melmer, Andreas; Ebenbichler, Christoph; Müller, Tom; Burtscher, Martin

    2017-01-01

    The prevention of type 2 diabetes in persons at risk for diabetes is of utmost importance. Physical activity in general and even exercises at moderate intensities such as walking significantly reduce the risk of the development of type 2 diabetes. However, it is still a matter of debate whether lipids and glucose metabolism are differently affected by regular concentric (e.g., uphill walking) and eccentric (e.g., downhill walking) endurance exercise. The aim of this study was to investigate the effects of short-term (3 weeks) uphill and downhill walking on glucose metabolism and blood lipids in pre-diabetic middle-aged men in a real world setting. The study was designed as an investigator-initiated 2 group random selection pre-test post-test trial. Sixteen pre-diabetic men (age: 56.9 ± 5.1 years; BMI: 28.1 ± 2.3 kg·m-2) performed 9 uphill (n = 8) or 9 downhill (n = 8) walking sessions within 3 weeks. The primary outcomes were the markers of glucose metabolism and blood lipids measured before and after the training period. After uphill walking glucose tolerance (area under the curve of the oral glucose tolerance test: -43.25 ± 53.12 mg·dl-1; p = 0.05; effect size: 0.81), triglycerides (-48.75 ± 54.49 mg·dl-1; p = 0.036; effect size: 0.89), HDL-C (+7.86 ± 9.54 mg·dl-1; p = 0.05; effect size: 0.82) and total cholesterol/HDL-C ratio (-0.58 ± 0.41; p = 0.012; effect size: 1.39) had significantly improved. No significant metabolic adaptations were found after downhill walking. However, when adjusted for estimated energy expenditure, uphill and downhill walking had equal effects on almost all metabolic parameters. Moreover, the magnitude of the baseline impairments of glucose tolerance was significantly related to the extent of change in both groups. Depending on the fitness level and individual preferences both types of exercise may be useful for the prevention of type 2 diabetes and disorders in lipid metabolism. Key points In contrast to downhill walking, 3

  11. Blood glucose prediction using neural network

    NASA Astrophysics Data System (ADS)

    Soh, Chit Siang; Zhang, Xiqin; Chen, Jianhong; Raveendran, P.; Soh, Phey Hong; Yeo, Joon Hock

    2008-02-01

    We used neural network for blood glucose level determination in this study. The data set used in this study was collected using a non-invasive blood glucose monitoring system with six laser diodes, each laser diode operating at distinct near infrared wavelength between 1500nm and 1800nm. The neural network is specifically used to determine blood glucose level of one individual who participated in an oral glucose tolerance test (OGTT) session. Partial least squares regression is also used for blood glucose level determination for the purpose of comparison with the neural network model. The neural network model performs better in the prediction of blood glucose level as compared with the partial least squares model.

  12. 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.

  13. Senescence marker protein-30/gluconolactonase deletion worsens glucose tolerance through impairment of acute insulin secretion.

    PubMed

    Hasegawa, Goji; Yamasaki, Masahiro; Kadono, Mayuko; Tanaka, Muhei; Asano, Mai; Senmaru, Takafumi; Kondo, Yoshitaka; Fukui, Michiaki; Obayashi, Hiroshi; Maruyama, Naoki; Nakamura, Naoto; Ishigami, Akihito

    2010-02-01

    Senescence marker protein-30 (SMP30) is an androgen-independent factor that decreases with age. We recently identified SMP30 as the lactone-hydrolyzing enzyme gluconolactonase (GNL), which is involved in vitamin C biosynthesis in animal species. To examine whether the age-related decrease in SMP30/GNL has effects on glucose homeostasis, we used SMP30/GNL knockout (KO) mice treated with L-ascorbic acid. In an ip glucose tolerance test at 15 wk of age, blood glucose levels in SMP30/GNL KO mice were significantly increased by 25% at 30 min after glucose administration compared with wild-type (WT) mice. Insulin levels in SMP30/GNL KO mice were significantly decreased by 37% at 30 min after glucose compared with WT mice. Interestingly, an insulin tolerance test showed a greater glucose-lowering effect in SMP30/GNL KO mice. High-fat diet feeding severely worsened glucose tolerance in both WT and SMP30/GNL KO mice. Morphometric analysis revealed no differences in the degree of high-fat diet-induced compensatory increase in beta-cell mass and proliferation. In the static incubation study of islets, insulin secretion in response to 20 mm glucose or KCl was significantly decreased in SMP30/GNL KO mice. On the other hand, islet ATP content at 20 mm in SMP30/GNL KO mice was similar to that in WT mice. Collectively, these data indicate that impairment of the early phase of insulin secretion due to dysfunction of the distal portion of the secretion pathway underlies glucose intolerance in SMP30/GNL KO mice. Decreased SMP30/GNL may contribute to the worsening of glucose tolerance that occurs in normal aging.

  14. Community-Based Lifestyle Intervention for Reducing Blood Pressure and Glucose among Middle-Aged and Older Adults in China: A Pilot Study

    PubMed Central

    Lin, Aihua; Zhang, Guanrong; Liu, Zhiting; Gu, Jing; Chen, Weiqing; Luo, Futian

    2014-01-01

    Although evidence suggests that lifestyle interventions can reduce blood pressure (BP) and glucose levels, there is little information about the feasibility of such interventions when implemented in community settings. This study evaluated the effectiveness of a community-based lifestyle intervention on BP and glucose in the middle-aged and older Chinese population. By using a cluster randomisation approach, 474 participants from two communities were assigned to the intervention group which received intensive health education and behavioural intervention, or the control group which received conventional education. Linear mixed models were used to compare between-group differences on change in BP and fasting glucose after 6, 12 and 24 months. At the 12-month follow-up, the intervention group experienced significantly reductions in systolic BP (−4.9 vs. 2.4 mmHg; mean difference [MD] −7.3 mmHg; p < 0.001), diastolic BP (−1.9 vs. 1.9 mmHg; MD −3.8 mmHg; p < 0.001) and fasting glucose (−0.59 vs. 0.08 mmol/L; MD −0.67 mmol/L; p < 0.001). These differences were sustained at the 24-month follow-up. With only two communities, it was not possible to adjust for potential clustering by site. This approach of lifestyle interventions conducted through primary care services may be a potential solution for combating hypertension and diabetes in a resource-limited country context in China. PMID:25402562

  15. The elevated preoperative fasting blood glucose predicts a poor prognosis in patients with esophageal squamous cell carcinoma: The Fujian prospective investigation of cancer (FIESTA) study

    PubMed Central

    Hu, Dan; Peng, Feng; Lin, Xiandong; Chen, Gang; Liang, Binying; Li, Chao; Zhang, Hejun; Liao, Xuehong; Lin, Jinxiu; Zheng, Xiongwei; Niu, Wenquan

    2016-01-01

    Diabetes as a latent risk factor for cancer has been extensively investigated, while its postoperative prognosis for esophageal cancer is rarely reported. We therefore sought to assess whether the elevated fasting blood glucose before surgery was associated with poor survival in esophageal cancer patients by eliciting a subset of data from the ongoing Fujian prospective investigation of cancer (FIESTA) study. Over 15-year follow-up, 2535 patients receiving three-field lymphadenectomy were assessable. Only patients with esophageal squamous cell carcinoma (ESCC) (n=2396) were analyzed due to the lower prevalence of the other histological types. In ESCC patients, the follow-up duration ranged from 0.5 to 180 months (median 38.2 months). The median survival time (MST) was remarkably shorter in males than in females (80.7 vs. 180+ months, Log-rank test: P<0.001). In males, the survival was worse in patients with diabetes than those without (MST: 27.9 vs. 111.1 months, Log-rank test: P<0.001). In females, the survivor was improved in patients with diabetes (MST: 71.5 months), but was still worse than patients without diabetes (MST: 180+ months, Log-rank test: P<0.001). The overall multivariate hazard ratio for per unit increment in fasting blood glucose was 1.11 (95% confidence interval or CI: 1.09-1.14, P<0.001) and 1.08 (95% CI: 1.03-1.13, P=0.002) in males and females, respectively. Further survival tree analysis consolidated the discrimination ability of fasting blood glucose for the survival of ESCC patients. Taken together, our findings convincingly demonstrated that the elevated preoperative fasting blood glucose can predict poor survival of ESCC patients, especially in males. PMID:27533454

  16. The elevated preoperative fasting blood glucose predicts a poor prognosis in patients with esophageal squamous cell carcinoma: The Fujian prospective investigation of cancer (FIESTA) study.

    PubMed

    Hu, Dan; Peng, Feng; Lin, Xiandong; Chen, Gang; Liang, Binying; Li, Chao; Zhang, Hejun; Liao, Xuehong; Lin, Jinxiu; Zheng, Xiongwei; Niu, Wenquan

    2016-10-04

    Diabetes as a latent risk factor for cancer has been extensively investigated, while its postoperative prognosis for esophageal cancer is rarely reported. We therefore sought to assess whether the elevated fasting blood glucose before surgery was associated with poor survival in esophageal cancer patients by eliciting a subset of data from the ongoing Fujian prospective investigation of cancer (FIESTA) study. Over 15-year follow-up, 2535 patients receiving three-field lymphadenectomy were assessable. Only patients with esophageal squamous cell carcinoma (ESCC) (n=2396) were analyzed due to the lower prevalence of the other histological types. In ESCC patients, the follow-up duration ranged from 0.5 to 180 months (median 38.2 months). The median survival time (MST) was remarkably shorter in males than in females (80.7 vs. 180+ months, Log-rank test: P<0.001). In males, the survival was worse in patients with diabetes than those without (MST: 27.9 vs. 111.1 months, Log-rank test: P<0.001). In females, the survivor was improved in patients with diabetes (MST: 71.5 months), but was still worse than patients without diabetes (MST: 180+ months, Log-rank test: P<0.001). The overall multivariate hazard ratio for per unit increment in fasting blood glucose was 1.11 (95% confidence interval or CI: 1.09-1.14, P<0.001) and 1.08 (95% CI: 1.03-1.13, P=0.002) in males and females, respectively. Further survival tree analysis consolidated the discrimination ability of fasting blood glucose for the survival of ESCC patients. Taken together, our findings convincingly demonstrated that the elevated preoperative fasting blood glucose can predict poor survival of ESCC patients, especially in males.

  17. The Effect of Tofogliflozin Treatment on Postprandial Glucose and Lipid Metabolism in Japanese Men With Type 2 Diabetes: A Pilot Study

    PubMed Central

    Kakuda, Hirokazu; Kobayashi, Junji; Sakurai, Masaru; Kakuda, Masahiro; Takekoshi, Noboru

    2017-01-01

    Background Postprandial hyperglycemia and hyperlipidemia are highly related to the development of atherosclerosis. Sodium/glucose cotransporter-2 (SGLT2) inhibitors have attracted attention as a new class of anti-diabetic agents for the treatment of type 2 diabetes. We investigated the effect of tofogliflozin on postprandial glucose and lipid metabolism in Japanese male patients with type 2 diabetes. Methods Ten Japanese men with type 2 diabetes (average age 66.3 years) were orally administered tofogliflozin (20 mg per day) for 8 weeks followed by a subsequent 8 weeks of washout of the agent. At 0, 8 and 16 weeks, postprandial metabolic parameters were measured at 0, 60 and 120 min after cookie ingestion. Results There were significant reductions in body weight and body mass index at 8 weeks. There was a reduction in HbA1c at 8 weeks, which returned to pretreatment levels at 16 weeks. Serum insulin levels did not change during the entire study period under either fasting or postprandial state. The area under the curve of plasma glucagon significantly increased at 8 weeks. There were no changes in lipid and lipoprotein levels either in fasting or postprandial state except for tendency toward reduction in postprandial triglycerides at 8 weeks and increase in HDL-C at 16 weeks. Conclusions Tofogliflozin treatment causes an improvement of postprandial glucose metabolism but not considerable postprandial lipid metabolism. PMID:28392860

  18. Interpretation of metabolic memory phenomenon using a physiological systems model: What drives oxidative stress following glucose normalization?

    PubMed Central

    Voronova, Veronika; Zhudenkov, Kirill; Helmlinger, Gabriel; Peskov, Kirill

    2017-01-01

    Hyperglycemia is generally associated with oxidative stress, which plays a key role in diabetes-related complications. A complex, quantitative relationship has been established between glucose levels and oxidative stress, both in vitro and in vivo. For example, oxidative stress is known to persist after glucose normalization, a phenomenon described as metabolic memory. Also, uncontrolled glucose levels appear to be more detrimental to patients with diabetes (non-constant glucose levels) vs. patients with high, constant glucose levels. The objective of the current study was to delineate the mechanisms underlying such behaviors, using a mechanistic physiological systems modeling approach that captures and integrates essential underlying pathophysiological processes. The proposed model was based on a system of ordinary differential equations. It describes the interplay between reactive oxygen species production potential (ROS), ROS-induced cell alterations, and subsequent adaptation mechanisms. Model parameters were calibrated using different sources of experimental information, including ROS production in cell cultures exposed to various concentration profiles of constant and oscillating glucose levels. The model adequately reproduced the ROS excess generation after glucose normalization. Such behavior appeared to be driven by positive feedback regulations between ROS and ROS-induced cell alterations. The further oxidative stress-related detrimental effect as induced by unstable glucose levels can be explained by inability of cells to adapt to dynamic environment. Cell adaptation to instable high glucose declines during glucose normalization phases, and further glucose increase promotes similar or higher oxidative stress. In contrast, gradual ROS production potential decrease, driven by adaptation, is observed in cells exposed to constant high glucose. PMID:28178319

  19. Body mass index, blood pressure, and glucose and lipid metabolism among permanent and fixed-term workers in the manufacturing industry: a cross-sectional study

    PubMed Central

    2014-01-01

    Background Temporary employment, a precarious form of employment, is recognized as social determinant of poor health. However, evidence supporting precarious employment as a risk factor for health is mainly obtained from subjective data. Studies using objective clinical measurement data in the assessment of health status are limited. This study compared body mass index (BMI), lipid and glucose metabolism, and health-related lifestyle factors between permanent workers and fixed-term workers employed in the manufacturing industry. Methods Data of 1,701 male manufacturing industry workers <50 years old in Japan were collected and analyzed. Anthropometric data were BMI, calculated using measured height and weight of study participants, and blood pressure. For lipid metabolism, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and triglyceride levels were determined. For glucose metabolism, fasting plasma glucose and hemoglobin A1c (HbA1c) levels were measured. Multiple regression analysis adjusted for age and lifestyle factors was performed. Results BMI was significantly higher in permanent workers (22.9 kg/m2) compared with fixed-term workers (22.4 kg/m2). The leaner population (BMI < 18.5) was greater among fixed-term workers (8.3%) compared with permanent workers (4.0%), whereas the overweight population (BMI ≥ 25.0) was greater among permanent workers (21.4%) compared with fixed-term workers (18.1%). Although fixed-term workers tended not to be overweight, regression analysis adjusted for age and lifestyle factors suggested that fixed-term employment was significantly associated with higher blood pressure (systolic β = 2.120, diastolic β = 2.793), triglyceride (β = 11.147), fasting blood glucose (β = 2.218), and HbA1c (β = 0.107) compared with permanent workers (all p < 0.01). Conclusions Fixed-term workers showed more health risks, such as poorer blood pressure and lipid and glucose metabolism

  20. Pharmacodynamic Effects of Canagliflozin, a Sodium Glucose Co-Transporter 2 Inhibitor, from a Randomized Study in Patients with Type 2 Diabetes

    PubMed Central

    Sha, Sue; Devineni, Damayanthi; Ghosh, Atalanta; Polidori, David; Hompesch, Marcus; Arnolds, Sabine; Morrow, Linda; Spitzer, Heike; Demarest, Keith; Rothenberg, Paul

    2014-01-01

    Introduction This randomized, double-blind, placebo-controlled, single and multiple ascending-dose study evaluated the pharmacodynamic effects and safety/tolerability of canagliflozin, a sodium glucose co-transporter 2 inhibitor, in patients with type 2 diabetes. Methods Patients (N = 116) discontinued their antihyperglycemic medications 2 weeks before randomization. Patients received canagliflozin 30, 100, 200, or 400 mg once daily or 300 mg twice daily, or placebo at 2 study centers in the United States and Germany, or canagliflozin 30 mg once daily or placebo at 1 study center in Korea, while maintaining an isocaloric diet for 2 weeks. On Days –1, 1, and 16, urinary glucose excretion (UGE), plasma glucose (PG), fasting PG (FPG), and insulin were measured. The renal threshold for glucose (RTG) was calculated from UGE, PG, and estimated glomerular filtration rate. Safety was evaluated based on adverse event (AE) reports, vital signs, electrocardiograms, clinical laboratory tests, and physical examinations. Results Canagliflozin increased UGE dose-dependently (∼80–120 g/day with canagliflozin ≥100 mg), with increases maintained over the 14-day dosing period with each dose. Canagliflozin dose-dependently decreased RTG, with maximal reductions to ∼4–5 mM (72–90 mg/dL). Canagliflozin also reduced FPG and 24-hour mean PG; glucose reductions were seen on Day 1 and maintained over 2 weeks. Plasma insulin reductions with canagliflozin were consistent with observed PG reductions. Canagliflozin also reduced body weight. AEs were transient, mild to moderate in intensity, and balanced across groups; 1 canagliflozin-treated female reported an episode of vaginal candidiasis. Canagliflozin did not cause hypoglycemia, consistent with the RTG values remaining above the hypoglycemia threshold. At Day 16, there were no clinically meaningful changes in urine volume, urine electrolyte excretion, renal function, or routine laboratory test values. Conclusions

  1. Influence of the presence of Zymomonas anaerobia on the conversion of cellobiose, glucose, and xylose to ethanol by Clostridium saccharolyticum

    SciTech Connect

    Asther, M.; Khan, A.W.

    1984-01-01

    To convert sugar mixtures containing cellobiose, glucose, and xylose to ethanol in a single step, the possibility of using a coculture consisting of Clostridium saccharolyticum and Zymomonas anaerobia was studied. In monoculture, C. saccharolyticum utilized all three sugars; however, it preferentially utilized glucose and produced acetic acid in addition to ethanol. The formation of acetic acid from the metabolism of glucose inhibited the growth of C. saccharolyticum and, consequently, the utilization of cellobiose and xylose. In monoculture, Z. anaerobia utilized glucose at a rate of 50 g/L day, but it did not ferment cellobiose or xylose. In coculture, Z. anaerobia converted most of the glucose to ethanol during the lag phase of growth of C. saccharolyticum, which then converted cellobiose and xylose to ethanol. The use of this coculture increased both the rate and the efficiency of the conversion of these three sugars to ethanol, and produced relatively small amounts of acetic acid.

  2. Reactor physics studies in the GCFR Phase III critical assembly

    SciTech Connect

    Morman, J A

    1980-03-01

    The third phase of the gas cooled fast reactor (GCFR) program, ZPR-9 Assembly 30, is based on a multi-zoned core of PuO/sub 2/-UO/sub 2/ with radial and axial blankets of UO/sub 2/. Studies performed in this assembly will be compared to the previous phases of the GCFR program and will help to define parameters in this power-flattened demonstration plant-type core. Measurements in the Phase III program included small sample reactivity worths of various materials, central reaction rates and reaction rate distributions, absorption-to-fission ratios and the central point conversion ratio and the worth of steam entry into a small central zone. The reactivity change associated with the construction of a central pin zone in the core and axial blanket was measured. Reaction rate and steam entry measurements were repeated in the pin environment. Standard analysis methods using ENDF/B-IV data are described and the results are compared to measurements performed during the program.

  3. Density functional theory study of phase IV of solid hydrogen

    NASA Astrophysics Data System (ADS)

    Pickard, Chris J.; Martinez-Canales, Miguel; Needs, Richard J.

    2012-06-01

    We have studied solid hydrogen up to pressures of 300 GPa and temperatures of 350 K using density functional theory methods and have found “mixed structures” that are more stable than those predicted earlier. Mixed structures consist of alternate layers of strongly bonded molecules and weakly bonded graphene-like sheets. Quasiharmonic vibrational calculations show that mixed structures are the most stable at room temperature over the pressure range 250-295 GPa. These structures are stabilized with respect to strongly bonded molecular phases at room temperature by the presence of lower frequency vibrational modes arising from the graphene-like sheets. Our results for the mixed structures are consistent with the experimental Raman data [M. I. Eremets and I. A. Troyan, Nat. Mater.1476-112210.1038/nmat3175 10, 927 (2011) and R. T. Howie , Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.108.125501 108, 125501 (2012)]. We find that mixed phases are reasonable structural models for phase IV of hydrogen.

  4. Amphitropic liquid crystal phases from polyhydroxy sugar surfactants: Fundamental studies

    NASA Astrophysics Data System (ADS)

    Abou Zied, Osama K.; Hashim, Rauzah; Timimi, B. A.

    2015-03-01

    The self-assembly phenomena on a special class of poly-hydroxy sugar surfactant have been studied extensively. This class of material is classified as amphitropic liquid crystals since they exhibit both thermotropic and lyotropic liquid crystalline properties. Hence the potential applications of these non-ionic surfactants are more versatile than those from the conventional lyotropic liquid crystals including those from thermotropic phases, but the latters are yet to be realized. Unfortunately, due to the lack of interest (or even awareness), fundamental studies in thermotropic glycolipids are scanty to support application development, and any tangible progress is often mired by the complexity of the sugar stereochemistry. However, some applications may be pursued from these materials by taking the advantage of the sugar chirality and the tilted structure of the lipid organization which implies ferroelectric behavior. Here, we present our studies on the stereochemical diversity of the sugar units in glycosides that form the thermotropic/lyotropic phases. The structure to property relationship compares different chain designs and other popular polyhydroxy compounds, such as monooleins and alkylpolyglucosides. Different structural properties of these glycosides are discussed with respect to their self-assembly organization and potential applications, such as delivery systems and membrane mimetic study.

  5. A Condensed Phase Study of Ion-molecule Species

    NASA Astrophysics Data System (ADS)

    Tardif, M.; MacTaylor, R. S.

    2001-05-01

    Hydrogen chloride (HCl) plays a key role in a number of chemical reactions relevant to ozone levels in the polar stratosphere. Numerous studies have targeted a greater understanding of the properties of HCl as it reacts with water-ice mimics of Polar Stratospheric Clouds (PSCs). Surface studies have yeilded results that indicate gasseous HCl will dissolve into a solid ice layer. Gas-phase water cluster studies show similar results and propose a model accounting for HCl reactivity on PSC surfaces. This Molecular Activation by Surface Coordination (MASC) model suggests that molecular HCl is coordinated on the cloud surface by interaction with dissolved chloride ions. Molecular dynamics simulations indicate that such a species exists in concentrated hydrochloric acid. The present study seeks to use Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared (FTIR) spectroscopic techniques to provide direct experimental evidence for molecular hydrogen chloride associated with chloride ions in solution.

  6. Uric Acid Is More Strongly Associated with Impaired Glucose Regulation in Women than in Men from the General Population: The KORA F4-Study

    PubMed Central

    Meisinger, Christa; Döring, Angela; Stöckl, Doris; Thorand, Barbara; Kowall, Bernd; Rathmann, Wolfgang

    2012-01-01

    Objective High serum uric acid (UA) levels are associated with the metabolic syndrome, type 2 diabetes and cardiovascular disease. It is largely unknown whether there are gender-specific differences regarding the association between UA and prediabetic states. We examined the possible association between UA levels and known as well as newly diagnosed diabetes (NDD), isolated impaired fasting glucose (i-IFG), isolated impaired glucose tolerance (i-IGT), and combined IFG/IGT in a population-based sample of 32-to-81-year-old men and women. Research Design and Methods An oral glucose tolerance test was carried out in all 2,740 participants without known diabetes of the Cooperative Health Research in the Region of Augsburg (KORA) F4 Study conducted between 2006 and 2008 in Southern Germany. Serum UA was analysed by the uricase method. Results In women after multivariable adjustment the associations between UA and i-IFG (OR 1.57, 95% CI 1.15–2.14), IFG/IGT (OR 1.52, 1.07–2.16), NDD (OR 1.67, 95% CI 1.28–2.17), and known diabetes (OR 1.47, 95% CI 1.18–1.82) remained significant, but the association with i-IGT (OR 1.14, 95% CI 0.95–1.36) lost significance. In contrast in men, after multivariable adjustment there was only a significant association between UA levels and i-IFG (OR 1.49, 95% CI 1.21–1.84), all other associations were non-significant (i-IGT: OR 1.09, IFG/IGT: OR 1.06, NDD: OR 0.91, known diabetes: OR 1.04; all p-values>0.05). Conclusions Serum UA concentrations were associated with different categories of impaired glucose regulation in individuals from the general population, particularly in women. Further studies investigating the role of UA in the development of derangements in glucose metabolism are needed. PMID:22615932

  7. Association between Markers of Fatty Liver Disease and Impaired Glucose Regulation in Men and Women from the General Population: The KORA-F4-Study

    PubMed Central

    Rückert, Ina-Maria; Heier, Margit; Rathmann, Wolfgang; Baumeister, Sebastian E.; Döring, Angela; Meisinger, Christa

    2011-01-01

    Objective To investigate whether the elevated liver enzymes gamma-glutamyltransferase (GGT), glutamate-pyruvate transaminase (GPT), glutamate-oxalacetate transaminase (GOT) and alkaline phosphatase (AP) and non-alcoholic fatty liver disease (NAFLD) respectively are independently associated with pre-diabetic states, namely impaired fasting glucose (IFG) and impaired glucose tolerance (IGT) or known and newly diagnosed diabetes (NDD), in men and women from the general German population. Methods The study was based on 3009 subjects (1556 females, 1453 males) aged 32 to 81 years who participated in the KORA-F4-Study in 2006/2008 in Augsburg, Southern Germany. All non-diabetic participants underwent an oral glucose tolerance test to assess disturbances in glucose metabolism. NAFLD was estimated by liver enzyme concentrations and the Bedogni Fatty Liver Index (FLI). Results 229 participants (7.6%) reported known diabetes, 106 had NDD (3.5%), 107 (3.6%) had IFG, 309 (10.3%) had IGT, 69 (2.3%) were affected with both metabolic disorders (IFG/IGT) and 74 (2.5%) could not be classified. GGT and GPT were significantly elevated in persons with pre-diabetes and diabetes (GGT in diabetic persons OR = 1.76, [1.47–2.09], in IFG OR = 1.79 [1.50–2.13], GPT in diabetic persons OR = 1.51, [1.30–1.74], in NDD OR = 1.77 [1.52–2.06]), GOT and AP only inconsistently in some pre-diabetes groups. The effects were sharpened in models using an increase of two or three out of three enzymes as an estimate of fatty liver and especially in models using the FLI. Overall frequency of NAFLD applying the index was 39.8% (women: 27.3% and men: 53.2%). In participants with fatty liver disease, the OR for NDD adjusted for sex and age was 8.48 [5.13–14.00], 6.70 [3.74–12.01] for combined IFG and IGT and 4.78 [3.47–6.59] for known diabetes respectively. Conclusions Elevated GGT and GPT–values as well as estimates of fatty liver disease are significantly associated with pre

  8. Lifestyle Factors Associated with Type 2 Diabetes and Use of Different Glucose-Lowering Drugs: Cross-Sectional Study

    PubMed Central

    Ulrichsen, Sinna P.; Mor, Anil; Svensson, Elisabeth; Larsen, Finn B.; Thomsen, Reimar W.

    2014-01-01

    Aims To examine the lifestyle profile among persons with and without Type 2 diabetes mellitus (DM) and among users of different glucose-lowering drugs. Methods We used questionnaire data from a Danish health survey and identified presence of Type 2 DM and use of medications through medical databases. We calculated age- and gender-standardized prevalence ratios (PRs) of lifestyle factors according to Type 2 DM and different glucose-lowering drugs. Results Of 21,637 survey participants aged 25–79 years, 680 (3%) had Type 2 DM (median age 63 years) with a median diabetes duration of 5 years. Participants with Type 2 DM had a substantially higher prevalence of obesity (36% vs. 13%, PR: 3.1, 95% confidence interval (CI): 2.8–3.6), yet more reported to eat a very healthy diet (25% vs. 21%, PR: 1.2, 95% CI: 1.0–1.4) and to exercise regularly (67% vs. 53%, PR: 1.3, 95% CI: 1.2–1.4). Also, fewer were current smokers or had high alcohol intake. When compared with metformin users, obesity was substantially less prevalent in users of sulfonylurea (PR: 0.5, 95% CI: 0.4–0-8), and insulin and analogues (PR: 0.4, 95% CI: 0.3–0.7). Tobacco smoking was more prevalent in sulfonylurea users (PR: 1.4, 95% CI: 0.9–2.1) compared with metformin users. We found no material differences in physical exercise, diet or alcohol intake according to type of glucose-lowering drug. Conclusions Type 2 DM patients are substantially more obese than other individuals, but otherwise report to have a healthier lifestyle. Metformin use is strongly associated with obesity, whereas sulfonylurea use tends to be associated with tobacco smoking. PMID:25369331

  9. Inhibition effects of ethanol on the kinetics of glucose metabolism by S. cerevisiae: NMR and modelling study

    NASA Astrophysics Data System (ADS)

    Ricci, Maso; Martini, Silvia; Bonechi, Claudia; Trabalzini, Lorenza; Santucci, Annalisa; Rossi, Claudio

    2004-04-01

    Saccharomyces cerevisiae is an important model to understand the eukaryotic cells control mechanisms. In this Letter, an approach based on in vivo13C NMR and mathematical modelling was presented to develop a basis for a deeper understanding of eukaryotic responses to environmental stresses. Despite the few metabolites included, the model describes correctly the dynamical behaviour of glucose degradation and ethanol production, providing a qualitative and quantitative description of the response of S. cerevisiae metabolism to stressful concentrations of ethanol. The data and the model highlight that an exogenous stress is able to influence the cellular activity and the ethanol production rate constant.

  10. A Prospective Study of Different Types of Dietary Fiber and Risk of Cardiovascular Disease: Tehran Lipid and Glucose Study

    PubMed Central

    Mirmiran, Parvin; Bahadoran, Zahra; Khalili Moghadam, Sajad; Zadeh Vakili, Azita; Azizi, Fereidoun

    2016-01-01

    Background and aim: This study was designed to examine the hypothesis that dietary of intake different types of fiber could modify the risk of cardiovascular disease (CVD) in a large prospective cohort among Iranian adults. Methods: In 2006–2008, we used a validated food frequency questionnaire to assess dietary fiber intake among 2295 health professionals with no previous history of heart disease. Subjects were subsequently followed until 2012 for incidence of CVD events. Multivariate Cox proportional hazard regression models, adjusted for potential confounders were used to estimate the risk of CVD across tertiles of total dietary fiber and different types of fiber. Linear regression models were also used to indicate the association of dietary fiber intakes with changes of cardiovascular risk factors during the follow-up. Results: Mean age of participants (42.8% men) was 38.2 ± 13.4, at baseline. Mean (SD) dietary intake of total fiber was 23.4 (8.9) g/day. After adjustment for cardiovascular risk score and dietary confounders, a significant inverse association was observed between intakes of total, soluble and insoluble dietary fiber and CVD risk, in the highest compared to the lowest tertiles (HR = 0.39, 95% CI = 0.18–0.83, HR = 0.19, 95% CI = 0.09–0.41, and HR = 0.31, 95% CI = 0.14–0.69, respectively). Inverse relations were observed between risk of CVD and dietary fiber from legumes, fruits and vegetables; however, dietary fiber intake from grain and nut sources was not related to risk of CVD. Conclusion: Our findings confirmed that higher intakes of dietary fiber from different sources is associated with CVD events and modify its major risk-related factors. PMID:27827978

  11. Neurotransmitters in the Gas Phase: La-Mb Studies

    NASA Astrophysics Data System (ADS)

    Cabezas, C.; Mata, S.; López, J. C.; Alonso, J. L.

    2011-06-01

    LA-MB-FTMW spectroscopy combines laser ablation with Fourier transform microwave spectroscopy in supersonic jets overcoming the problems of thermal decomposition associated with conventional heating methods. We present here the results on LA-MB-FTMW studies of some neurotransmitters. Six conformers of dopamine, four of adrenaline, five of noradrenaline and three conformers of serotonin have been characterized in the gas phase. The rotational and nuclear quadrupole coupling constants extracted from the analysis of the rotational spectrum are directly compared with those predicted by ab initio methods to achieve the conclusive identification of different conformers and the experimental characterization of the intramolecular forces at play which control conformational preferences.

  12. Study of a splat cooled Cu-Zr-noncrystalline phase.

    NASA Technical Reports Server (NTRS)

    Revcolevschi, A.; Grant, N. J.

    1972-01-01

    By rapid quenching from the melt, using the splat forming gun technique, a noncrystalline phase has been obtained in a Cu-Zr alloy containing 60 at. % Cu. Upon heating, rapid crystallization of the samples takes place at 477 C with a heat release of about 700 cal per mol. The variation of the electrical resistivity of the samples with temperature confirms the transformation. Very high resolution electron microscopy studies of the structural changes of the samples upon heating are presented and show the gradual crystallization of the amorphous structure.

  13. 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

  14. Effect of Portal Glucose Sensing on Systemic Glucose Levels in SD and ZDF Rats

    PubMed Central

    Pal, Atanu; Rhoads, David B.; Tavakkoli, Ali

    2016-01-01

    Background The global epidemic of Type-2-Diabetes (T2D) highlights the need for novel therapeutic targets and agents. Roux-en-Y-Gastric-Bypass (RYGB) is the most effective treatment. Studies investigating the mechanisms of RYGB suggest a role for post-operative changes in portal glucose levels. We investigate the impact of stimulating portal glucose sensors on systemic glucose levels in health and T2D, and evaluated the role of sodium-glucose-cotransporter-3 (SGLT3) as the possible sensor. Methods Systemic glucose and hormone responses to portal stimulation were measured. In Sprague-Dawley (SD) rats, post-prandial state was simulated by infusing glucose into the portal vein. The SGLT3 agonist, alpha-methyl-glucopyranoside (αMG), was then added to further stimulate the portal sensor. To elucidate the neural pathway, vagotomy or portal denervation was followed by αMG+glucose co-infusion. The therapeutic potential of portal glucose sensor stimulation was investigated by αMG-only infusion (vs. saline) in SD and Zucker-Diabetic-Fatty (ZDF) rats. Hepatic mRNA expression was also measured. Results αMG+glucose co-infusion reduced peak systemic glucose (vs. glucose alone), and lowered hepatic G6Pase expression. Portal denervation, but not vagotomy, abolished this effect. αMG-only infusion lowered systemic glucose levels. This glucose-lowering effect was more pronounced in ZDF rats, where portal αMG infusion increased insulin, C-peptide and GIP levels compared to saline infusions. Conclusions The portal vein is capable of sensing its glucose levels, and responds by altering hepatic glucose handling. The enhanced effect in T2D, mediated through increased GIP and insulin, highlights a therapeutic target that could be amenable to pharmacological modulation or minimally-invasive surgery. PMID:27806092

  15. Bentonite-amended soil special study. Phase 1 evaluation report

    SciTech Connect

    Not Available

    1989-12-01

    This special study was conducted to assess the viability of soil with a high percentage of bentonite added as an infiltration barrier in the cover of Uranium Mill Tailings Remedial Action (UMTRA) Project disposal cells. To achieve maximum concentration limits (MCLs) at several UMTRA Project sites, covers with a very low permeability are needed. If alternate concentration limits (ACLs) are the appropriate site groundwater compliance strategy, the US Department of Energy (DOE) is required to demonstrate, among other things, that the infiltration to the disposal cell is as low as reasonably achievable, and hence that the cover has a very low permeability. When the study discussed here was begun, the lowest permeability element available was CLAYMAX{sub R}, a manufactured liner material constructed of natural material (bentonite clay) between two geosynthetics.The strength of soil-bentonite mixes was measured to see if they could be placed on sideslopes and not pose stability problems. Also evaluated were the hydraulic conductivities of soil-bentonite mixes. If the strengths and permeabilities of soils with a high percentage of bentonite are favorable, the soils may be used as infiltration barriers in current cover designs without changing pile geometries. The scope of work for this study called for a literature review and a two-phased laboratory testing program. This report presents the results of the literature review and the first phase of the testing program.

  16. The Study of the Thermoelectric Properties of Phase Change Materials

    NASA Astrophysics Data System (ADS)

    Yin, Ming; Abdi, Mohammed; Noimande, Zibusisu; Mbamalu, Godwin; Alameeri, Dheyaa; Datta, Timir

    We study thermoelectric property that is electrical phenomena occurring in conjunction with the flow of heat of phase-change materials (PCM) in particular GeSbTe (GST225). From given sets of material parameters, COMSOL Multiphysics heat-transfer module is used to compute maps of temperature and voltage distribution in the PCM samples. These results are used to design an apparatus including the variable temperature sample holder set up. An Arbitrary/ Function generator and a circuit setup is also designed to control the alternation of heaters embedded on the sample holder in order to ensure sequential back and forward flow of heat current from both sides of the sample. Accurate values of potential differences and temperature distribution profiles are obtained in order to compute the Seebeck coefficient of the sample. The results of elemental analysis and imaging studies such as XRD, UV-VIS, EDEX and SEM of the sample are obtained. Factors affecting the thermoelectric properties of phase change memory are also discussed. NNSA/ DOD Consortium for Materials and Energy Studies.

  17. 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

  18. Ketones suppress brain glucose consumption.

    PubMed

    LaManna, Joseph C; Salem, Nicolas; Puchowicz, Michelle; Erokwu, Bernadette; Koppaka, Smruta; Flask, Chris; Lee, Zhenghong

    2009-01-01

    The brain is dependent on glucose as a primary energy substrate, but is capable of utilizing ketones such as beta-hydroxybutyrate (beta HB) and acetoacetate (AcAc), as occurs with fasting, prolonged starvation or chronic feeding of a high fat/low carbohydrate diet (ketogenic diet). In this study, the local cerebral metabolic rate of glucose consumption (CMRglu; microM/min/100g) was calculated in the cortex and cerebellum of control and ketotic rats using Patlak analysis. Rats were imaged on a rodent PET scanner and MRI was performed on a 7-Tesla Bruker scanner for registration with the PET images. Plasma glucose and beta HB concentrations were measured and 90-minute dynamic PET scans were started simultaneously with bolus injection of 2-Deoxy-2[18F]Fluoro-D-Glucose (FDG). The blood radioactivity concentration was automatically sampled from the tail vein for 3 min following injection and manual periodic blood samples were taken. The calculated local CMRGlu decreased with increasing plasma BHB concentration in the cerebellum (CMRGlu = -4.07*[BHB] + 61.4, r2 = 0.3) and in the frontal cortex (CMRGlu = -3.93*[BHB] + 42.7, r2 = 0.5). These data indicate that, under conditions of ketosis, glucose consumption is decreased in the cortex and cerebellum by about 10% per each mM of plasma ketone bodies.

  19. Mission Analysis for the Don Quijote Phase-A Study

    NASA Technical Reports Server (NTRS)

    Cano, Juan L.; Sanchez, Mariano; Cornara, Stefania; Carnelli, Ian

    2007-01-01

    The Don Quijote Phase-A study is a definition study funded by ESA and devoted to the analysis of the possibilities to deflect a Near Earth Object (NEO) in the range of 300-800 m diameter. DEIMOS Space S.L. and EADS Astrium have teamed up within this study to form one of the three consortia that have analyzed these aspects for ESA. Target asteroids for the mission are 1989 ML, 2002 AT4 and Apophis. This paper presents the mission analysis activities within the consortium providing: low-thrust interplanetary rendezvous Orbiter trajectories to the target asteroids, ballistic interplanetary trajectories for the Impactor, Orbiter arrival description at the asteroids, Orbiter stable orbits characterization at the asteroid, deflection determination by means of a Radio Science Experiment (RSE) as well as the mission timelines and overall mission scenarios.

  20. A Phase 1 biodistribution study of p-boronophenylalanine

    SciTech Connect

    Coderre, J.A.

    1991-01-01

    The objectives of the Phase I BPA biodistribution study are as follows: Objective 1: To establish the safety of orally administered boronophenylalanine (BPA) as determined by monitoring of patient's vital signs and by clinical analysis of blood before and after BPA administration. Objective 2: To establish BPA pharmacokinetics by monitoring the rates of boron absorption into and clearance from the blood and the rate of urinary excretion of boron. Objective 3: To measure the amount of boron incorporated into human tumors (melanoma, glioma, and breast carcinoma) using samples obtained at surgery or biopsy. This report presents the results obtained from the first thirteen patients entered into the study. Three additional glioblastoma patients have been studied recently at Stony Brook, the tissues are still being analyzed.

  1. A Phase 1 biodistribution study of p-boronophenylalanine

    SciTech Connect

    Coderre, J.A.

    1991-12-31

    The objectives of the Phase I BPA biodistribution study are as follows: Objective 1: To establish the safety of orally administered boronophenylalanine (BPA) as determined by monitoring of patient`s vital signs and by clinical analysis of blood before and after BPA administration. Objective 2: To establish BPA pharmacokinetics by monitoring the rates of boron absorption into and clearance from the blood and the rate of urinary excretion of boron. Objective 3: To measure the amount of boron incorporated into human tumors (melanoma, glioma, and breast carcinoma) using samples obtained at surgery or biopsy. This report presents the results obtained from the first thirteen patients entered into the study. Three additional glioblastoma patients have been studied recently at Stony Brook, the tissues are still being analyzed.

  2. Higher magnesium intake is associated with lower fasting glucose and insulin, with no evidence of interaction with select genetic loci, in a meta-analysis of 15 charge consortium studies

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Favorable associations between magnesium intake and glycemic traits, such as fasting glucose and insulin, are observed in observational and clinical studies, but whether genetic variation affects these associations is largely unknown. We hypothesized that single nucleotide polymorphisms (SNPs) assoc...

  3. Phase behaviour and conductivity study of electrolytes in supercritical hydrofluorocarbons.

    PubMed

    Bartlett, Philip N; Cook, David C; George, Michael W; Ke, Jie; Levason, William; Reid, Gillian; Su, Wenta; Zhang, Wenjian

    2011-01-07

    The purpose of this work was to characterise supercritical hydrofluorocarbons (HFC) that can be used as solvents for electrodeposition. The phase behaviour of CHF(3), CH(2)F(2), and CH(2)FCF(3) containing [NBu(n)(4)][BF(4)], [NBu(n)(4)][B{3,5-C(6)H(3)(CF(3))(2)}(4)] and Na[B{3,5-C(6)H(3)(CF(3))(2)}(4)] was studied and the conditions for forming a single supercritical phase established. Although all three HFCs are good solvents for [NBu(n)(4)][BF(4)] the results show that the CH(2)F(2) system has the lowest p(r) for dissolving a given amount of [NBu(n)(4)][BF(4)]. The solubility of Na[B{3,5-C(6)H(3)(CF(3))(2)}(4)] in CH(2)F(2) was found to be unexpectedly high. Studies of the phase behaviour of CH(2)F(2) containing [NBu(n)(4)][BF(4)] and [Cu(CH(3)CN)(4)][BF(4)] showed that the copper complex was unstable in the absence of CH(3)CN. For CHF(3), [Cu(hfac)(2)] was more soluble and more stable than [Cu(CH(3)CN)(4)][BF(4)] and only increased the phase-separation pressure by a moderate amount. Studies of the conductivity of [NBu(n)(4)][B(C(6)F(5))(4)], [NBu(n)(4)][B{3,5-C(6)H(3)(CF(3))(2)}(4)], [NR(f)Bu(n)(3)][B{3,5-C(6)H(3)(CF(3))(2)}(4)] (R(f) = (CH(2))(3)C(7)F(15)), and Na[B{3,5-C(6)H(3)(CF(3))(2)}(4)] were carried out in scCH(2)F(2). The results show that these salts are more conducting than [NBu(n)(4)][BF(4)] under the same conditions although the increase is much less significant than that reported in previous work in supercritical CO(2) + CH(3)CN. Consequently, either [NBu(n)(4)][BF(4)] or the corresponding BARF salts would be suitable background electrolytes for electrodeposition from scCH(2)F(2).

  4. Glycemic load effect on fasting and post-prandial serum glucose, insulin, IGF-1 and IGFBP-3 in a randomized, controlled feeding study

    PubMed Central

    Runchey, Shauna S.; Pollak, Michael N.; Valsta, Liisa M.; Coronado, Gloria D.; Schwarz, Yvonne; Breymeyer, Kara L.; Wang, Chiachi; Wang, Ching-Yun; Lampe, Johanna W.; Neuhouser, Marian L.

    2012-01-01

    Background/Objectives The effect of a low glycemic load (GL) diet on insulin-like growth factor-1 (IGF-1) concentration is still unknown but may contribute to lower chronic disease risk. We aimed to assess the impact of GL on concentrations of IGF-1 and IGFBP-3. Subjects/Methods We conducted a randomized, controlled crossover feeding trial in 84 overweight-obese and normal weight healthy individuals using two 28-day weight-maintaining high- and low-GL diets. Measures were fasting and post-prandial concentrations of insulin, glucose, IGF-1 and IGFBP-3. 20 participants completed post-prandial testing by consuming a test breakfast at the end of each feeding period. We used paired t-tests for diet-component and linear mixed models for biomarker analyses. Results The 28-day low-GL diet led to 4% lower fasting concentrations of IGF-1 (10.6 ng/mL, p=0.04) and a 4% lower ratio of IGF-1/IGFBP-3 (0.24, p=0.01) compared to the high-GL diet. The low-GL test breakfast led to 43% and 27% lower mean post-prandial glucose and insulin responses, respectively; mean incremental areas under the curve for glucose and insulin, respectively, were 64.3±21.8 (mmol/L/240min) (p<0.01) and 2253±539 (μU/mL/240min) (p<0.01) lower following the low- compared to the high-GL test meal. There was no effect of GL on mean HOMA-IR or on mean integrated post-prandial concentrations of glucose-adjusted insulin, IGF-1 or IGFBP-3. We did not observe modification of the dietary effect by adiposity. Conclusions Low-GL diets resulted in 43% and 27% lower post-prandial responses of glucose and insulin, respectively, and modestly lower fasting IGF-1 concentrations. Further intervention studies are needed to weigh the impact of dietary GL on risk for chronic disease. PMID:22892437

  5. Effect of ovarian suppression with gonadotropin-releasing hormone agonist on glucose disposal and insulin secretion.

    PubMed

    Toth, Michael J; Cooper, Brian C; Pratley, Richard E; Mari, Andrea; Matthews, Dwight E; Casson, Peter R

    2008-06-01

    Several lines of evidence suggest that ovarian hormones influence glucose homeostasis, although their exact role in humans has not been clearly defined. In the present study, we sought to test the hypothesis that ovarian hormones regulate glucose homeostasis by examining the effect of pharmacologically induced ovarian hormone deficiency on glucose disposal and insulin secretion. Young, healthy women with regular menstrual patterns were studied during the follicular and luteal phases of their cycle at baseline and after 2 mo of treatment with gonadotropin-releasing hormone agonist (GnRHa; n = 7) or placebo (n = 6). Using hyperglycemic clamps, in combination with stable isotope-labeled (i.e., (13)C and (2)H) glucose tracers, we measured glucose disposal and insulin secretion. Additionally, we assessed body composition and regional fat distribution using radiologic imaging techniques as well as glucoregulatory hormones. Ovarian hormone suppression with GnRHa did not alter body composition, abdominal fat distribution, or thigh tissue composition. There was no effect of ovarian suppression on total, oxidative, or nonoxidative glucose disposal expressed relative to plasma insulin level. Similarly, no effect of ovarian hormone deficiency was observed on first- or second-phase insulin secretion or insulin clearance. Finally, ovarian hormone deficiency was associated with an increase in circulating adiponectin levels but no change in leptin concentration. Our findings suggest that a brief period of ovarian hormone deficiency in young, healthy, eugonadal women does not alter glucose disposal index or insulin secretion, supporting the conclusion that ovarian hormones play a minimal role in regulating glucose homeostasis. Our data do, however, support a role for ovarian hormones in the regulation of plasma adiponectin levels.

  6. Higher magnesium intake is associated with lower fasting glucose and insulin, with no evidence of interaction with select genetic loci, in a meta-analysis of 15 CHARGE Consortium Studies.

    PubMed

    Hruby, Adela; Ngwa, Julius S; Renström, Frida; Wojczynski, Mary K; Ganna, Andrea; Hallmans, Göran; Houston, Denise K; Jacques, Paul F; Kanoni, Stavroula; Lehtimäki, Terho; Lemaitre, Rozenn N; Manichaikul, Ani; North, Kari E; Ntalla, Ioanna; Sonestedt, Emily; Tanaka, Toshiko; van Rooij, Frank J A; Bandinelli, Stefania; Djoussé, Luc; Grigoriou, Efi; Johansson, Ingegerd; Lohman, Kurt K; Pankow, James S; Raitakari, Olli T; Riserus, Ulf; Yannakoulia, Mary; Zillikens, M Carola; Hassanali, Neelam; Liu, Yongmei; Mozaffarian, Dariush; Papoutsakis, Constantina; Syvänen, Ann-Christine; Uitterlinden, André G; Viikari, Jorma; Groves, Christopher J; Hofman, Albert; Lind, Lars; McCarthy, Mark I; Mikkilä, Vera; Mukamal, Kenneth; Franco, Oscar H; Borecki, Ingrid B; Cupples, L Adrienne; Dedoussis, George V; Ferrucci, Luigi; Hu, Frank B; Ingelsson, Erik; Kähönen, Mika; Kao, W H Linda; Kritchevsky, Stephen B; Orho-Melander, Marju; Prokopenko, Inga; Rotter, Jerome I; Siscovick, David S; Witteman, Jacqueline C M; Franks, Paul W; Meigs, James B; McKeown, Nicola M; Nettleton, Jennifer A

    2013-03-01

    Favorable associations between magnesium intake and glycemic traits, such as fasting glucose and insulin, are observed in observational and clinical studies, but whether genetic variation affects these associa