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Sample records for glucose analogs measured

  1. PET measurement of glucose membrane transport using labeled analogs: Distinction of transport from metabolic processes

    International Nuclear Information System (INIS)

    Carrier mediated glucose transport rates across brain capillary and myocardial cell membranes are many times higher than those expected for simple diffusion, and transport regulation can be an important determinant of tissue metabolic status. The authors have investigated the use of glucose analogs and dynamic positron tomography for the non-invasive measurement of unidirectional membrane transport rates. If analog extraction is sufficiently low, transport rates can be inferred directly from fitted kinetic rate constants. Fitting calculations were seen to be sensitive to the difficult to measure rapid components of the arterial input curves, to contributions from blood-borne label in the early data points, and to interference from other chemical forms in cases of significant phosphorylation. This last uncertainty was studied using serial scans of normal brain after venous injection of the well-transported but poorly phosphorylated analog 3-deoxy-3-fluoroglucose. Transport rate constants derived from 4-parameter fits of three hours of data were compared to those derived from 2-parameter fits of the first 12-20 minutes of data. Errors due to trapped label were absorbed primarily into the apparent distribution volume, allowing accurate estimation of transport rate constants from a brief data acquisition period. The study of the distinction of transport from phosphorylation also bears on the important question of the significance of the individual rate constants in the foof the individual rate constants in the four-parameter fitting of brief dynamic scan sequences in studies of metabolic rate using 2-deoxy-2-fluoroglucose

  2. Alternative approach to single-scan estimation of cerebral glucose metabolic rate using glucose analogs, with particular application to ischemia

    International Nuclear Information System (INIS)

    In the glucose analog method for determining local glucose utilization rates, time courses of tissue and plasma radioactivity are measured and then analyzed in terms of first-order exchange of label between tissue compartments. The rate of glucose utilization is assumed to have a fixed, linear relationship to the analog phosphorylation rate calculated from the fitted rate constants. Accurate estimation of the rate constants requires many hours of dynamic data acquisition. Therefore, techniques assuming a linear relationship between analog phosphorylation rate and total tissue concentration of label were developed to predict glucose utilization rates from a single scan. Previously reported linearizations differ in their sensitivity to differences between current and average kinetic rate constants, and thus in their accuracy. We have developed a method that is insensitive to the presumed value of the blood flow-capillary wall transport parameter k1. This new single-scan approach has been validated by comparison of the single-scan metabolic rate values with the values calculated from the dynamic measurements

  3. A Comparative Study on the Antioxidant and Glucose-lowering Effects of Curcumin and Bisdemethoxycurcumin Analog through in vitro Assays

    Directory of Open Access Journals (Sweden)

    S. Sivabalan

    2010-01-01

    Full Text Available Type 2 diabetes has emerged as an epidemic affecting millions of people all over the world. Several research findings suggest that oxidative stress is the triggering factor for the development of type 2 diabetes. Hyperglycemia and oxidative stress go hand in hand to accelerate the disease progression in a vicious cycle. In India, the medicinal herb Curcuma longa is used as a culinary food additive and also as a therapeutic agent for diabetes. Recent research evidenced that the curcuminoids present in Curcuma longa have several medicinal properties including anti-diabetic property. However, the bioavailability of curcumin is very less compared to its derivatives and its synthetic analogs. The synthetic analog of bisdemethoxycurcumin is reported to have increased bioavailability and stability but its effect on controlling oxidative stress, glucose absorption and gluconeogenesis have not yet been explored. The aim of this study was to evaluate the anti-oxidant and glucose lowering effects of bisdemethoxycurcumin analog (BDMCA in comparison with curcumin. Anti-oxidant activity of BDMCA and curcumin was evaluated by measuring the rate of inhibition of iron-ascorbate induced lipid peroxidation in liver homogenate in vitro. Effect of these drugs on intestinal glucose absorption in Wistar rats and on gluconeogenesis in liver homogenate in vitro was evaluated to know their glucose lowering effects. We found that both the BDMCA and curcumin lower the gluconeogenesis in the hepatocytes and function as antioxidants in vitro in a similar manner. Both BDMCA and curcumin delays the intestinal glucose absorption but BDMCA delays the intestinal glucose absorption more effectively compared to curcumin.

  4. Challenges of inpatient blood glucose monitoring: standards, methods, and devices to measure blood glucose.

    Science.gov (United States)

    Hermayer, Kathie L; Loftley, Aundrea S; Reddy, Sumana; Narla, Satya Nandana; Epps, Nina A; Zhu, Yusheng

    2015-03-01

    Glucose control in the hospital setting is very important. There is a high incidence of hyperglycemia, hypoglycemia, and glycemic variability in hospitalized patients. Safe insulin delivery and glucose control is dependent on reliable glucose meters and monitoring systems in the hospital. Different glucose monitoring systems use arterial, venous, central venous, and capillary blood samples. It is important for clinicians to be aware that there are limitations of specific point-of-care (POC) glucose meters and that situations exist whereby POC glucose meters as the sole measurement device should be avoided. POC meter devices are not approved by the Food and Drug Administration for use in critical care, although POC meter devices are commonly used in critical care settings and elsewhere. This review focuses on glucose assay principles, instrument technology, influences on glucose measurement, standards for glucose measurement, and an evaluation of different methods to measure blood glucose in the hospital setting. PMID:25644818

  5. Non-Invasive Optical Blood Glucose Measurement

    Directory of Open Access Journals (Sweden)

    Megha C.Pande

    2013-07-01

    Full Text Available The method for noninvasively blood glucose monitoring system is discussed in this paper. Lot of research work has been done in developing the device which is completely noninvasive to avoid the pros & cons because of frequent pricking. In this paper we are trying to analyze the noninvasive blood glucose measurement study in the near infrared region which is the most suitable region for blood glucose measurement. For this purpose we use a technique which is similar to pulseoximetry based on near infrared spectrometry .An infrared light of particular wavelength is passed through fingertip containing an arterial pulse component are derived,thus minimizing influences of basal components such as resting blood volume,skin, muscle and bone.

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

    International Nuclear Information System (INIS)

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

  7. Clinical Experience of an Iontophoresis Based Glucose Measuring System

    OpenAIRE

    Rhee, Sang Youl; Chon, Suk; Koh, Gwanpyo; Paeng, Jeong Ryung; Oh, Seungjoon; Woo, Jeong-taek; Kim, Sung Woon; KIM, Jin-Woo; Kim, Young Seol

    2007-01-01

    Currently finger pricking is the common method of blood glucose measurement in patients with diabetes mellitus. However, diabetes patients have proven to be reluctant to check their glucose profiles regularly because of the discomfort associated with this technique. Recently, a non-invasive and continuous Reverse Iontophoresis based Glucose Monitoring Device (RIGMD) was developed in Korea. The study was conducted during the period November 2003-January 2004 on 19 in-patients. Glucose measurem...

  8. [Noninvasive continuous measurement of blood glucose concentration via animal skin].

    Science.gov (United States)

    Wang, Jian; Li, Fang; Zhang, Wei; Wang, Jie; Gao, Haiyan; Wei, Suping; Zhang, Shibi; Ran, Junguo; Gou, Li; Zhou, Song

    2003-12-01

    In this study we deliberated over the principles and methods and then took the noninvasive continuous measurement of blood glucose concentration through the skin of rabbits. The glucose oxidase sensor was made by covalent immobilization. The best making method of sensor and stable working condition were sifted. Ten female and 10 male adult white rabbits were allocated into the groups of the ante-ultrasound and post-ultrasound, the injection of glucose, and the high and low frequency ultrasounds. After the skin surface was treated by high or low frenquency ultrasound for 5 minutes on the rabbits, obvious changes (P microcurrent apparatus. After application of ultrasound to the skin of rabbits, the penetration of glucose through the rabbit skin increased obviously. The change of microcurrent signal that was exchanged by the glucose sensor correlated positively with the concentration of glucose of rabbit body. The blood glucose can be tested by the glucose sensor on the skin surface of living animal. PMID:14716859

  9. Microcalorimetric Measurements of Glucose Metabolism by Marine Bacterium Vibrio alginolyticus

    OpenAIRE

    Gordon, Andrew S.; Millero, Frank J.; Gerchakov, Sol M.

    1982-01-01

    Microcalorimetric measurements of heat production from glucose by Vibrio alginolyticus were made to assess the viability of calorimetry as a technique for studying the metabolism of marine bacteria at organic nutrient concentrations found in marine waters. The results show that the metabolism of glucose by this bacterium can be measured by calorimetry at submicromolar concentrations. A linear correlation between glucose concentration and total heat production was observed over a concentration...

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

    International Nuclear Information System (INIS)

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

  11. Activity of P536, a UDP-glucose analog, against Trypanosoma cruzi

    International Nuclear Information System (INIS)

    P536, a UDP-glucose analog which was previously described as an antiviral agent, has a potent and selective activity against the intracellular and extracellular stages of Trypanosoma cruzi in vitro. It had a 50% inhibitory concentration of less than 5 micrograms/ml for T. cruzi extracellular cultured forms (epimastigote) and of 25 micrograms/ml for T. cruzi intracellular forms (amastigote) growing inside J774G8 macrophage-like cells. In contrast, the 50% inhibitory concentration was 100 micrograms/ml or greater for cultured mammalian cells and 180 micrograms/ml for the proliferation of mouse spleen lymphocytes. Furthermore, the addition of P536 (50 micrograms/ml) to T. cruzi-infected J774G8 cells cured the infected macrophages, making them able to grow and function normally. Studies on the mechanism of action of this drug indicated that it inhibited incorporation of [35S]methionine, [3H]thymidine, [3H]mannose, [14C]-N-acetylglucosamine, and [3H]uridine into macromolecules by T. cruzi epimastigotes, the last being the most sensitive

  12. Interaction of uridine diphosphate glucose analogs with calf liver uridine diphosphate glucose dehydrogenase. Influence of substituents at C-5 of pyrimidine nucleus.

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    Shibaev, V N; Eliseeva, G I; Kochetkov, N K

    1975-09-22

    The interaction of alpha-D-glucopyranosyl pyrophosphates of 5-X-uridines (X = CH3, NH2, CH3O, I, Br, Cl, OH) with uridine diphosphate glucose (UDPGlc) dehydrogenase (EC 1.1.1.22) from calf liver has been studied. All the derivatives investigated were able to serve as substrates for the enzyme. The apparent Michaelis constants for UDPGlc-analogs were dependent both on electronic and steric factors. Increase of substituent negative inductive effect lead to decrease of pKa for ionization of the NH-group in the uracil nucleus and, consequently, to a diminishing of the proportion of the active analog species under the conditions of assay. After correction for the ionization effect, the Km values were found to depend on the van der Waals radius of the substituent. The value of 1.95 A seems to be critical, as the analogs with bulkier substituents at C-5 showed a decreased affinity to the enzyme. The maximal velocity values of the analogs were also dependent on nature of the substituent. Good linear correlation between log V and substituent hydrophobic phi-constant was observed for a number of the analogs, although V values for the nucleotides with X = H, OH or NH2 were higher than would be expected on the basis of the correlation. The significance of the results for understanding of the topography of UDPGlc dehydrogenase active site is discussed. PMID:1174552

  13. Prediction of Glucose Concentration by Impedance Phase Measurements

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    Guevara, Edgar; González, Francisco Javier

    2008-08-01

    In recent years researchers have explored non-invasive techniques for glucose testing such as near infrared spectroscopy, light scattering, photoacoustic spectroscopy, and electrical impedance measurements, without achieving the accuracy of the traditional invasive method. In this paper, measurements in the 1-13 MHz band show that glucose directly affects the impedance parameters of solutions and the effect is more evident in the phase angle; therefore, these impedance phase measurements can be employed to predict the concentration of glucose in vitro, obtaining a smaller error of prediction than previous techniques.

  14. Expression of Human Globular Adiponectin-Glucagon-Like Peptide-1 Analog Fusion Protein and Its Assay of Glucose-Lowering Effect In Vivo

    OpenAIRE

    Tongfeng Zhao, Jing Lv

    2011-01-01

    In this study, human globular adiponectin-glucagon-like peptide-1 analog (gAd-GLP-1-A) fusion protein was expressed and its glucose-lowering effect was measured in vivo. We constructed a prokaryotic expression vector PET28a-gAd-GLP-1-A and transformed the vector into Escherichia coli BL21 (DE3). A recombinant fusion protein of about 25KD was expressed from BL21 (DE3) cells after isopropylthio-?-D-galactoside induction. This protein was N-terminal His-tagged gAd-GLP-1-A fusion protein. Mo...

  15. In vitro measurements with electrocatalytic glucose sensor in blood.

    Science.gov (United States)

    Preidel, W; Saeger, S

    1989-01-01

    The principle of measurement with electrocatalytic glucose sensor is based on the direct electrochemical oxidation of glucose at an active and membrane-covered noble metal electrode. The objective is to measure glucose in the range of diffusion limiting current, since the glucose concentration in front of the membrane is proportional to the oxidative current. The determination of glucose concentration is realized by considering the electrode processes taking place at different potentials, and by measuring the impedance of the electrode/membrane system using the conventional three-electrode arrangement. Performance and long-term stability of the sensor are mainly dependent on the properties of the membrane and on the poisoning reactions at the electrode. Using this method, measurements were carried out in defibrinated sheep blood at 37 degrees C. After reproducible in vitro measurements could be made with the sensor over up to 3 weeks with an error of 20%, experiments were conducted in sheep using an extracorporeal circulation system. The correlation between the electrode signal and the glucose concentration in blood could be confirmed during glucose tolerance tests. PMID:2636834

  16. Blood Sugar Measurement in Zebrafish Reveals Dynamics of Glucose Homeostasis

    OpenAIRE

    Eames, Stefani C.; Philipson, Louis H.; Prince, Victoria E.; Kinkel, Mary D.

    2010-01-01

    The adult zebrafish has the potential to become an important model for diabetes-related research. To realize this potential, small-scale methods for analyzing pancreas function are required. The measurement of blood glucose level is a commonly used method for assessing ?-cell function, but the small size of the zebrafish presents challenges both for collecting blood samples and for measuring glucose. We have developed methods for collecting microsamples of whole blood and plasma for the meas...

  17. Portal glucose infusion-glucose clamp measures hepatic influence on postprandial systemic glucose appearance as well as whole body glucose disposal

    OpenAIRE

    Zheng, Dan; Ionut, Viorica; Mooradian, Vahe; Stefanovski, Darko; Bergman, Richard N

    2009-01-01

    The full impact of the liver, through both glucose production and uptake, on systemic glucose appearance cannot be readily studied in a classical glucose clamp because hepatic glucose metabolism is regulated not only by portal insulin and glucose levels but also portal glucose delivery (the portal signal). In the present study, we modified the classical glucose clamp by giving exogenous glucose through portal vein, the “portal glucose infusion (PoG)-glucose clamp”, to determine the net hepati...

  18. Clinical Experience of an Iontophoresis Based Glucose Measuring System

    Science.gov (United States)

    Rhee, Sang Youl; Chon, Suk; Koh, Gwanpyo; Paeng, Jeong Ryung; Oh, Seungjoon; Woo, Jeong-taek; Kim, Sung Woon; Kim, Jin-Woo

    2007-01-01

    Currently finger pricking is the common method of blood glucose measurement in patients with diabetes mellitus. However, diabetes patients have proven to be reluctant to check their glucose profiles regularly because of the discomfort associated with this technique. Recently, a non-invasive and continuous Reverse Iontophoresis based Glucose Monitoring Device (RIGMD) was developed in Korea. The study was conducted during the period November 2003-January 2004 on 19 in-patients. Glucose measurements were performed using RIGMD between 10 a.m. and 4 p.m. Concurrent plasma glucose levels were checked hourly and subsequently compared with RIGMD data. The mean error of RIGMD measurements was -3.45±52.99 mg/dL with a mean absolute relative error of 20±15.16%. Measurements obtained by RIGMD were correlated with plasma glucose levels (correlation coefficient; 0.784 (p<0.05)) and this correlation was independent of time of data collection. However, after excluding confounding variables this correlation coefficient exhibited a tendency to increase. 98.9% of the results were clinically acceptable by Clarke error grid analysis. We concluded that RIGMD does not have the reliability and accuracy required to wholly replace conventional methods. However, further technical advancements that reduce its shortcomings would make this device useful for the management of diabetes. PMID:17297254

  19. Relationship between fluctuations in glucose levels measured by continuous glucose monitoring and vascular endothelial dysfunction in type 2 diabetes mellitus

    OpenAIRE

    Torimoto Keiichi; Okada Yosuke; Mori Hiroko; Tanaka Yoshiya

    2013-01-01

    Abstract Background Fluctuations in blood glucose level cause endothelial dysfunction and play a critical role in onset and/or progression of atherosclerosis. We hypothesized that fluctuation in blood glucose levels correlate with vascular endothelial dysfunction and that this relationship can be assessed using common bedside medical devices. Methods Fluctuations in blood glucose levels were measured over 24?hours by continuous glucose monitoring (CGM) on admission day 2 in 57 patients with...

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

    Science.gov (United States)

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

    2009-08-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Gable, J H

    2000-06-01

    A novel investigation into the fluorescence lifetimes of molecules, both established and newly designed, was performed. These molecules are the basis of a continuous, minimally invasive, glucose sensor based on fluorescence lifetime measurements. This sensor, if coupled with an automated insulin delivery device, would effectively create an artificial pancreas allowing for the constant monitoring and control of glucose levels in a person with diabetes. The proposed sensor includes a fluorescent molecule that changes its' fluorescence properties upon binding selectively and reversibly to glucose. One possible sensor molecule is N-methyl-N-(9-methylene anthryl)-2-methylenephenylboronic acid (AB). The fluorescence intensity of AB was shown to change in response to changing glucose concentrations. (James, 1994) James proposed that when glucose binds to AB the fluorescence intensity increases due to an enhancement of the N{yields}B dative bond which prevents photoinduced electron transfer (PET). PET from the amine (N) to the fluorophore (anthracene) quenches the fluorescence. The dative bond between the boron and the amine can prevent PET by involving the lone pair of electrons on the amine in interactions with the boron rather than allowing them to be transferred to the fluorophore. Results of this research show the average fluorescence lifetime of AB also changes with glucose concentration. It is proposed that fluorescence is due to two components: (1) AB with an enhanced N{yields}B interaction, and no PET, and (2) AB with a weak N{yields}B interaction, resulting in fluorescence quenching by PET. Lifetime measurements of AB as a function of both the pH of the solvent and glucose concentration in the solution were made to characterize this two component system and investigate the nature of the N{yields}B bond. Measurements of molecules similar to AB were also performed in order to isolate behavior of specific AB constituents. These molecules are 9-(Methylaminomethyl)-anthracene (MAMA), and N-benzyl-N-methyl-N-methyl anthracene (AB-B). Fluorescence lifetime measurements confirmed the two species of AB, with and without PET. Fluorescence lifetimes were approximately 11 nsec without PET and 3 nsec with PET. The degree of the interaction between the N and the B atoms was also determined by fluorescence lifetime measurements. Electron transfer rates of AB were measured to be on the order of 10{sup 8} sec{sup -1}. Analysis of AB as a glucose sensor shows it has the potential for measuring glucose concentrations in solution with less than 5% error. Two novel glucose sensing molecules, Chloro-oxazone boronate (COB) and Napthyl-imide boronate (NIB), were synthesized. Both molecules have a N{yields}B dative bond similar to AB, but with longer wavelength fluorophores. COB and NIB were found to be unacceptable for use as glucose sensor molecules due to the small changes in average fluorescence lifetime.

  2. Noninvasive blood glucose measurement using multiple laser diodes

    Science.gov (United States)

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

    2007-02-01

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

  3. Contribution to a decision making model for analogical measurement validation

    International Nuclear Information System (INIS)

    In limits of studies taken on validity of analogic measures in nuclear power plant's operation, the present thesis takes aim at establishment of a model to reaching a decision on the indice of probability on measures obtained by preliminary validation system. In a first step, it is proposed to retain a system made by redundant measures in which the calcul of measures is based on the coherence between measures themselves and logic vote. In the second step, one equation is proposed to compute the index of probability of measures taken in account, the characteristics of the system

  4. Tunable laser diode system for noninvasive blood glucose measurements.

    Science.gov (United States)

    Olesberg, Jonathon T; Arnold, Mark A; Mermelstein, Carmen; Schmitz, Johannes; Wagner, Joachim

    2005-12-01

    Optical sensing of glucose would allow more frequent monitoring and tighter glucose control for people with diabetes. The key to a successful optical noninvasive measurement of glucose is the collection of an optical spectrum with a very high signal-to-noise ratio in a spectral region with significant glucose absorption. Unfortunately, the optical throughput of skin is low due to absorption and scattering. To overcome these difficulties, we have developed a high-brightness tunable laser system for measurements in the 2.0-2.5 microm wavelength range. The system is based on a 2.3 microm wavelength, strained quantum-well laser diode incorporating GaInAsSb wells and AlGaAsSb barrier and cladding layers. Wavelength control is provided by coupling the laser diode to an external cavity that includes an acousto-optic tunable filter. Tuning ranges of greater than 110 nm have been obtained. Because the tunable filter has no moving parts, scans can be completed very quickly, typically in less than 10 ms. We describe the performance of the present laser system and avenues for extending the tuning range beyond 400 nm. PMID:16390586

  5. Laser-based measurement of glucose in the ocular aqueous humor: an efficacious portal for determination of serum glucose levels.

    Science.gov (United States)

    Steffes, P G

    1999-01-01

    The potential for the noninvasive measurement of blood glucose concentration to improve the level of blood sugar control and the quality of life of diabetic patients has been recognized for nearly 3 decades. Because of the many challenges involved in directly sensing glucose in the bloodstream noninvasively, the approach of noninvasive measurement of glucose concentration in the ocular aqueous humor, which reflects blood glucose concentration, has been likewise pursued over those 3 decades. Moreover, studies of the dynamic relationship between blood glucose concentration and ocular glucose concentration in both animals and humans suggest minimal latency between variations in blood glucose and those in ocular glucose. In a review of technological approaches to such measurements, the most promising techniques appear to be laser-based, and include laser polarimetry and Raman spectroscopy. Results for techniques such as multiwavelength polarimetry and Raman spectroscopy have been quite good, and it is likely that one or both of these techniques, possibly combined with refractive index measurement, will yield a useful instrument for both clinical use and patient self-monitoring. PMID:11475284

  6. Expression of Human Globular Adiponectin-Glucagon-Like Peptide-1 Analog Fusion Protein and Its Assay of Glucose-Lowering Effect In Vivo

    Directory of Open Access Journals (Sweden)

    Tongfeng Zhao, Jing Lv, Jiangpei Zhao, Xiao Huang, Haijuan Xiao

    2011-01-01

    Full Text Available In this study, human globular adiponectin-glucagon-like peptide-1 analog (gAd-GLP-1-A fusion protein was expressed and its glucose-lowering effect was measured in vivo. We constructed a prokaryotic expression vector PET28a-gAd-GLP-1-A and transformed the vector into Escherichia coli BL21 (DE3. A recombinant fusion protein of about 25KD was expressed from BL21 (DE3 cells after isopropylthio-?-D-galactoside induction. This protein was N-terminal His-tagged gAd-GLP-1-A fusion protein. Most of the protein was expressed in inclusion body. The fusion protein in inclusion body was purified by using High-Affinity Nickel Iminodiacetic Acid Resin and refolded in urea gradient refolding buffer. The refolded protein was incubated with enterokinase to remove the N-terminal His-tag. The fusion protein without His-tag is gAd-GLP-1-A fusion protein, which exhibited significant glucose-lowering effect in diabetic mice.

  7. Historical perspectives in clinical pathology: a history of glucose measurement.

    Science.gov (United States)

    Moodley, Nareshni; Ngxamngxa, Unathi; Turzyniecka, Magdalena J; Pillay, Tahir S

    2015-04-01

    This is the second in the series of historical articles dealing with developments in clinical pathology. As one of the most commonly measured analytes in pathology, the assessment of glucose dates back to the time of the ancient Egyptians. It was only in the 19th century that advances in chemistry led to the identification of the sugar in urine being glucose. The following century witnessed the development of more chemical and enzymatic methods which became incorporated into the modern analysers and point-of-care instruments which are as ubiquitous as the modern day cellphones. Tracking the milestones in these developments shows the striking paradigms and the many parallels in the development of other clinical chemistry methods. PMID:25568429

  8. Continuous measurement of glucose utilization in heart myoblasts.

    Science.gov (United States)

    Wiley, Carmen; Beeson, Craig

    2002-05-15

    Understanding quantitative aspects of cell energy metabolism and how it is influenced by environment is central to biology, medicine, and biotechnology. Most methods used for measuring metabolic fluxes associated with energy metabolism require considerable personnel effort or high maintenance instrumentation. The microphysiometer is a commercially available instrument that measures acid extrusion rates, which are commonly used for drug screening. With the addition of oxygen sensors, the instrument can also be used to measure cell oxygen consumption rates and thereby calculate glycolytic fluxes. In the work described here, oxygen consumption and acid extrusion rates were used to measure glucose utilization by the H9c2 rat heart myoblast cell line and these results are compared with fluxes measured with a radiometric assay. Both assays were used to investigate changes in H9c2 energy metabolism due to cell stimulation with carbachol and insulin. The results demonstrate the utility of the microphysiometer method for measuring both transient and sustained changes in partitioning of glucose utilization between glycolysis and oxidation in live cells. PMID:12009689

  9. AMPLITUDE AND TIME MEASUREMENT ASIC WITH ANALOG DERANDOMIZATION

    International Nuclear Information System (INIS)

    We describe a new ASIC for accurate and efficient processing of high-rate pulse signals from highly segmented detectors. In contrast to conventional approaches, this circuit affords a dramatic reduction in data volume through the use of analog techniques (precision peak detectors and time-to-amplitude converters) together with fast arbitration and sequencing logic to concentrate the data before digitization. In operation the circuit functions like a data-driven analog first-in, first-out (FIFO) memory between the preamplifiers and the ADC. Peak amplitudes of pulses arriving at any one of the 32 inputs are sampled, stored, and queued for readout and digitization through a single output port. Hit timing, pulse risetime, and channel address are also available at the output. Prototype chips have been fabricated in 0.35 micron CMOS and tested. First results indicate proper functionality for pulses down to 30 ns peaking time and input rates up to 1.6 MHz/channel. Amplitude accuracy of the peak detect and hold circuit is 0.3% (absolute). TAC accuracy is within 0.3% of full scale. Power consumption is less than 2 mW/channel. Compared with conventional techniques such as track-and-hold and analog memory, this new ASIC will enable efficient pulse height measurement at 20 to 300 times higher rates

  10. Effects of gamma-rays and glucose analogs on the energy metabolism of a cell line derived from human cerebral glioma

    International Nuclear Information System (INIS)

    Effects of gamma-rays and glucose analogs, 2-deoxy-D-glucose (2-DG), 5-thio-D-glucose (5-TG) and 3-O-methyl glucose (3-O-MG) on cellular energy metabolism have been studied in a cell line, derived from a human cerebral glioma, by analysing intermediates of glycolysis and some important nucleotides (ATP, NAD etc.) using the technique of isotachophoresis. Gamma-irradiation induced a transient decrease in the nucleotide levels accompanied by an accumulation of sugar phosphates, the nucleotide levels recovering in a few hours post-irradiation. 2-DG inhibited glycolysis and reduced the nucleotide levels of irradiated as well as unirradiated cells in a concentration-dependent manner both in presence and absence of respiration, whereas 5-TG and 3-OMG did not show significant effects in the presence of respiration. Reduced energy status observed with 2-DG under respiratory proficient conditions was completely reversed in 2 hr following its removal, whereas such a recovery was not observed in the absence of respiration. These results have important implications in the energy-linked modifications of tumor radiation response using glucose analogs. (author). 36 refs., 6 figs., 4 tabs

  11. Variability of capillary blood glucose monitoring measured on home glucose monitoring devices

    OpenAIRE

    Kotwal, Narendra; Pandit, Aditi

    2012-01-01

    Self monitoring of blood glucose helps achieve glycemic goals. Glucometers must be accurate. Many variables affect blood glucose levels. Factors are analytical variables (intrinsic to glucometer and glucose strips) and pre analytical related to patients. Analytical variables depend on factors like shelf life, amount of blood and enzymatic reactions. Preanalytical variables include pH of blood, hypoxia, hypotension, hematocrit etc. CGMS has the potential to revolutionise diabetes care but accu...

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

    International Nuclear Information System (INIS)

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

  13. Effect of delay on measurement of blood glucose levels in young subjects with type 1 diabetes.

    Science.gov (United States)

    Elleri, Daniela; Acerini, Carlo L; Allen, Janet M; Larsen, Anne-Mette F; Wilinska, Malgorzata E; Dunger, David B; Hovorka, Roman

    2009-11-01

    We investigated the effect of a 3-h time-lag between blood sampling and glucose measurement in type 1 diabetes. Blood glucose decreased by 0.47 mmol/L despite samples being collected in fluoride tubes and placed on ice. The extent of reduction differs among subjects, prevailing blood glucose and time-of-day of sample withdrawal. PMID:19643507

  14. Glucose measurement in interstitial fluid by microdialysis for the calibration of minimally invasive blood glucose monitoring

    Science.gov (United States)

    Li, Dachao; Wang, Ridong; Chong, Hao; Liu, Yu; Xu, Kexin

    2013-03-01

    According to the requirement of the calibration in minimally invasive blood glucose monitoring, a method based on microdialysis was presented to monitor glucose level in interstitial fluid continuously. An experimental system simulating the continuous change of glucose concentration in vivo was built. The influences on recovery of microdialysis caused by flow rate, glucose concentration, and temperature etc. were studied. The results led to the conclusion that the recovery fell by 71.7% when perfusion rate increased from 0.3 ?L/min to 3.0 ?L/min, while the different concentrations of glucose solutions scarcely contribute to the recovery instead, and the temperatures from 25 to 58 °C caused the recovery to increase by 34.6%.

  15. Relationship between fluctuations in glucose levels measured by continuous glucose monitoring and vascular endothelial dysfunction in type 2 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    Torimoto Keiichi

    2013-01-01

    Full Text Available Abstract Background Fluctuations in blood glucose level cause endothelial dysfunction and play a critical role in onset and/or progression of atherosclerosis. We hypothesized that fluctuation in blood glucose levels correlate with vascular endothelial dysfunction and that this relationship can be assessed using common bedside medical devices. Methods Fluctuations in blood glucose levels were measured over 24?hours by continuous glucose monitoring (CGM on admission day 2 in 57 patients with type 2 diabetes mellitus. The reactive hyperemia index (RHI, an index of vascular endothelial function, was measured using peripheral arterial tonometry (EndoPAT on admission day 3. Results The natural logarithmic-scaled RHI (L_RHI correlated with SD (r=?0.504; PPP=0.001 and percentage of time ?200?mg/dl (r=?0.292; P=0.028. In 12 patients with hypoglycemia, L_RHI also correlated with the percentage of time at hypoglycemia (r=?0.589; P=0.044. L_RHI did not correlate with HbA1c or fasting plasma glucose levels. Furthermore, L_RHI did not correlate with LDL cholesterol, HDL cholesterol, and triglyceride levels or with systolic and diastolic blood pressures. Finally, multivariate analysis identified MAGE as the only significant determinant of L_RHI. Conclusions Fluctuations in blood glucose levels play a significant role in vascular endothelial dysfunction in type 2 diabetes. Trial registration UMIN000007581

  16. Effects of hyperglycemia on glucose production and utilization in humans. Measurement with (3H)-2-, (3H)-3-, and (14C)-6-glucose

    Energy Technology Data Exchange (ETDEWEB)

    Bell, P.M.; Firth, R.G.; Rizza, R.A.

    1986-06-01

    Studies with tritiated isotopes of glucose have demonstrated that hyperglycemia per se stimulates glucose utilization and suppresses glucose production in humans. These conclusions rely on the assumption that tritiated glucose provides an accurate measure of glucose turnover. However, if in the presence of hyperglycemia the isotope either loses its label during futile cycling or retains its label during cycling through glycogen, then this assumption is not valid. To examine this question, glucose utilization and glucose production rates were measured in nine normal subjects with a simultaneous infusion of (/sup 3/H)-2-glucose, an isotope that may undergo futile cycling but does not cycle through glycogen; (/sup 14/C)-6-glucose, an isotope that may cycle through glycogen but does not futile cycle; and (/sup 3/H)-3-glucose, an isotope that can both undergo futile cycling and cycle through glycogen. In the postabsorptive state at plasma glucose concentration of 95 mg X dl-1, glucose turnover determined with (/sup 14/C)-6-glucose (2.3 +/- 0.1 mg X kg-1 X min-1) was greater than that determined with (3/sup 3/H)glucose (2.1 +/- 0.1 mg X kg-1 X min-1, P = 0.002) and slightly less than that determined with (/sup 3/H)-2-glucose (2.7 +/- 0.2 mg X kg-1 X min-1, P = 0.08). Plasma glucose was then raised from 95 to 135 to 175 mg X dl-1 while insulin secretion was inhibited, and circulating insulin, glucagon, and growth hormone concentrations were maintained constant by infusion of these hormones and somatostatin. Glucose production and utilization rates determined with (/sup 14/C)-6-glucose continued to be less than those determined with (/sup 3/H)-2-glucose and greater than those seen with (/sup 3/H)-3-glucose.

  17. Novel method to differentiate 3T3 L1 cells in vitro to produce highly sensitive adipocytes for a GLUT4 mediated glucose uptake using fluorescent glucose analog

    OpenAIRE

    Vishwanath, Divya; Srinivasan, Harini; Patil, Manjunath S.; Seetarama, Sowmya; Agrawal, Sachin Kumar; Dixit, M. N.; Dhar, Kakali

    2013-01-01

    Adipocytes play a vital role in glucose metabolism. 3T3 L1 pre adipocytes after differentiation to adipocytes serve as excellent in vitro models and are useful tools in understanding the glucose metabolism. The traditional approaches adopted in pre adipocyte differentiation are lengthy exercises involving the usage of IBMX and Dexamethasone. Any effort to shorten the time of differentiation and quality expression of functional differentiation in 3T3 L1 cells in terms of enhanced Insulin sensi...

  18. Development of an amperometric-based glucose biosensor to measure the glucose content of fruit.

    Science.gov (United States)

    Ang, Lee Fung; Por, Lip Yee; Yam, Mun Fei

    2015-01-01

    An amperometric enzyme-electrode was introduced where glucose oxidase (GOD) was immobilized on chitosan membrane via crosslinking, and then fastened on a platinum working electrode. The immobilized enzyme showed relatively high retention activity. The activity of the immobilized enzyme was influenced by its loading, being suppressed when more than 0.6 mg enzyme was used in the immobilization. The biosensor showing the highest response to glucose utilized 0.21 ml/cm2 thick chitosan membrane. The optimum experimental conditions for the biosensors in analysing glucose dissolved in 0.1 M phosphate buffer (pH 6.0) were found to be 35°C and 0.6 V applied potential. The introduced biosensor reached a steady-state current at 60 s. The apparent Michaelis-Menten constant ([Formula: see text]) of the biosensor was 14.2350 mM, and its detection limit was 0.05 mM at s/n > 3, determined experimentally. The RSD of repeatability and reproducibility of the biosensor were 2.30% and 3.70%, respectively. The biosensor was showed good stability; it retained ~36% of initial activity after two months of investigation. The performance of the biosensors was evaluated by determining the glucose content in fruit homogenates. Their accuracy was compared to that of a commercial glucose assay kit. There was no significance different between two methods, indicating the introduced biosensor is reliable. PMID:25789757

  19. Development of an Amperometric-Based Glucose Biosensor to Measure the Glucose Content of Fruit

    Science.gov (United States)

    Ang, Lee Fung; Por, Lip Yee; Yam, Mun Fei

    2015-01-01

    An amperometric enzyme-electrode was introduced where glucose oxidase (GOD) was immobilized on chitosan membrane via crosslinking, and then fastened on a platinum working electrode. The immobilized enzyme showed relatively high retention activity. The activity of the immobilized enzyme was influenced by its loading, being suppressed when more than 0.6 mg enzyme was used in the immobilization. The biosensor showing the highest response to glucose utilized 0.21 ml/cm2 thick chitosan membrane. The optimum experimental conditions for the biosensors in analysing glucose dissolved in 0.1 M phosphate buffer (pH 6.0) were found to be 35°C and 0.6 V applied potential. The introduced biosensor reached a steady-state current at 60 s. The apparent Michaelis-Menten constant (KMapp) of the biosensor was 14.2350 mM, and its detection limit was 0.05 mM at s/n > 3, determined experimentally. The RSD of repeatability and reproducibility of the biosensor were 2.30% and 3.70%, respectively. The biosensor was showed good stability; it retained ~36% of initial activity after two months of investigation. The performance of the biosensors was evaluated by determining the glucose content in fruit homogenates. Their accuracy was compared to that of a commercial glucose assay kit. There was no significance different between two methods, indicating the introduced biosensor is reliable. PMID:25789757

  20. Glucose and glycerol concentrations and their tracer enrichment measurements using liquid chromatography tandem mass spectrometry

    DEFF Research Database (Denmark)

    BornØ, Andreas; Foged, Lene

    2014-01-01

    The present study describes a new liquid chromatography tandem mass spectrometry method for high-throughput quantification of glucose and glycerol in human plasma using stable isotopically labeled internal standards and is suitable for simultaneous measurements of glucose and glycerol enrichments in connection to in vivo metabolic studies investigating glucose turnover and lipolytic rate. Moreover, in order to keep up with this new fast analysis, simple derivatization procedures have been developed. Prior to analysis, glucose and glycerol were derivatized using benzoyl chloride in order to form benzoylated derivatives via new simplified fast procedures. For glucose, two internal standards were evaluated, [U-(13) C(6)]glucose and [U-(13) C(6), D(7)]glucose, and for glycerol, [U-(13) C(3), D(8)]glycerol was used. The method was validated by means of calibration curves, quality control samples, and plasma samples spiked with [6,6-D(2)]glucose, [U-(13) C(6)]glucose, and [1,1,2,3,3-D(5)]glycerol in order to test accuracy, precision, and recovery of the method. Moreover, post preparative and freeze-thaw sample stability were tested. The correlation of calibration curves for the glucose concentration were r(2) =?0.9998 for [U-(13) C(6)]glucose and r(2) =?0.9996 for [U-(13) C(6), D(7)]glucose, and r(2) =?0.9995 for the glycerol concentration. Interday accuracy for glucose using [U-(13) C(6)]glucose and glycerol determined in spiked plasma were respectively 103.5% and 106.0%, and the coefficients of variation were 2.0% and 9.7%, respectively. After derivatization, plasma samples were stable for at least 14?days. In conclusion, we have developed and validated a novel, accurate, and sensitive high-throughput liquid chromatography tandem mass spectrometry method for simultaneous determination of glucose and glycerol concentrations and enrichment of infused tracers most commonly used in human metabolic kinetic studies.

  1. Measurement of the glucose transport time delay between the blood and aqueous humor of the eye for the eventual development of a noninvasive glucose sensor.

    Science.gov (United States)

    Cameron, B D; Baba, J S; Coté, G L

    2001-01-01

    In the recent past, several noninvasive optically based methods have been proposed for physiologic glucose sensing. One proposed optical sensing site has been the eye, which, due to its unique optical properties, can be considered as a transparent optical window into the body. In particular, the aqueous humor within the anterior chamber of the eye has been shown to contain glucose levels correlated to those of blood. Concern, however, has been expressed that using the aqueous humor solution as a measure of blood glucose may be problematic due to the potential transport time delay between the blood and the aqueous humor glucose concentrations. This investigation was performed to measure the transport time delay in a rabbit model. The time delay between the blood and aqueous humor glucose concentrations was measured invasively in five New Zealand White rabbits over a series of weeks. An anesthesia protocol containing the drug Xylazine was used to elevate the blood glucose levels to a level commonly seen in diabetic patients. The difference between the glucose peak location times occurring in the blood and aqueous humor glucose response was measured and defined as the transport time delay. The average transport time lag was measured to be under 5 min. This measured time delay indicates that, indeed, the eye could potentially be used as a sensing site for indirect blood glucose measurements and may eventually aid the development of a noninvasive glucose sensor due to its unique optical properties compared to other biological tissues. PMID:11478325

  2. Investigation of [18F]2-fluoro-2-deoxyglucose for the measure of myocardial glucose metabolism

    International Nuclear Information System (INIS)

    Fluorine-18-labeled 2-deoxyglucose (FDG) was studied as a glucose analog for the measure of myocardial glucose metabolism. Myocardial uptake and retention, blood clearance, species dependence (dog, monkey, man), and effect of diet on uptake were investigated. Normal myocardial uptake of FDG was 3 to 4% of injected dose in dog and monkey, and 1 to 4% in man, compared with brain uptakes of 1.5 to 3% in dog, 5 to 6% in monkey, and 4 to 8% in man. The myocardial metabolic rate (MR) for glucose in the nonfasting (glycolytic) state was 2.8 times that in the fasting (ketogenic) state. Human subjects showed higher myocardial uptake after a normal meal than after a meal containing mostly free fatty acids (FFA). Blood clearance was rapid with initial clearance t/sub 1/2/ of 0.2 to 0.3 min, followed by a t/sub 1/2/ of 8.4 +- 1.2 min in dog and 11.6 +- 1.1 min in man. A small third component had half-times of 59 +- 10 min and 88 +- 4 min in dog and man, respectively. With the ECAT positron tomograph, high image-contrast ratios were found between heart and blood (dog 3.5/1, man 14/1), heart and lung (dog 9/1, man 20/1), and heart and liver (dog 15/1, man 10/1). The FDG was taken up rapidly by the myocardium without any significant tissue clearance over a 4-hr period. The FDG exhibited excellent imaging properties. Average counting rates of 12K, 20K, and 40K c/min-mCi injected are obtained in human subjects with high, medium, and low resolutions of the ECAT tomograph. Determinationtions of the ECAT tomograph. Determination of glucose and FFA MR in vivo with EACT provides a method for investigation and assessment of changing aerobic and anaerobic metabolic rates in ischemic heart disease in man

  3. Differential half-maximal effects of human insulin and its analogs for in situ glucose transport and protein synthesis in rat soleus muscle

    Science.gov (United States)

    Weinstein, Randi B.; Eleid, Noura; LeCesne, Catherine; Durando, Bianca; Crawford, Julie T.; Heffner, Michelle; Layton, Christle; O'Keefe, Matthew; Robinson, Jennifer; Rudinsky, Suzy; Henriksen, Erik J.; Tischler, Marc E.

    2002-01-01

    Analogs of human insulin have been used to discriminate between responses of metabolic and mitogenic (growth-related) pathways. This study compared the stimulatory effects of human insulin (HI) and 2 analogs (X2, B-Asp(9), B-Glu(27) and H2, A-His(8),B-His(4),B-Glu(10), B-His(27)) on glucose uptake and protein synthesis in rat soleus muscle in situ. Glucose uptake, estimated by intramuscular (IM) injection of 2-deoxy[1,2-3H]glucose with or without insulin, was maximally increased at 10(-6) mol/L for HI and X2 and 10(-7) mol/L for H2. HI had a larger effect (318%) than either X2 (156%) or H2 (124%). The half-maximal effect (ED(50)) values for HI, X2, and H2 were 3.3 x10(-8) mol/L, 1.7 x 10(-7) mol/L, and 1.6 x 10(-9) mol/L, respectively. Protein synthesis, estimated by protein incorporation of [(3)H]phenylalanine injected into muscles with or without insulin, was maximally increased at 10(-5) mol/L for HI and 10(-6) for X2 and H2. HI had a larger effect in stimulating protein synthesis (34%) than either X2 (25%) or H2 (19.8%). The ED(50) values for HI, X2, and H2 were 3.0 x 10(-7) mol/L, 3.2 x 10(-7) mol/L, and 1.0 x 10(-9) mol/L, respectively. The biological potency of each analog (ED(50)insulin/ED(50)analog) showed X2 to be less potent than HI for both glucose uptake (0.2) and protein synthesis (0.9), whereas H2 is more potent than HI with ratios of 20 and 300, respectively. These data suggest that this approach for studying insulin responsiveness in a single muscle in situ may be a useful tool for investigating insulin signaling in muscle in vivo. Copyright 2002, Elsevier Science (USA). All rights reserved.

  4. Detection accuracy of three glucose meters estimated by capillary blood glucose measurements compared with venous blood evaluated by the diabetes unit of the Hospital Evangélico de Curitiba, Brazil

    Directory of Open Access Journals (Sweden)

    Camacho SL

    2012-05-01

    Full Text Available Mirnaluci Paulino Ribeiro Gama, Camile Fiorese Cruzeta, Ana Carolina Ossowski, Marina Rech Bay, Mariella Muller Michaelis, Stênio Lujan CamachoEndocrinology and Diabetes Service, Hospital Universitário Evangélico de Curitiba, BrazilObjective: To compare capillary blood glucose measurements between three different glucose meters and with the serum glucose values of inpatients at the diabetes unit of Hospital Universitário Evangélico de Curitiba, Brazil.Materials and methods: A total of 132 non-intensive care unit patients admitted for medical and surgical pathologies were evaluated. All patients reported a previous diagnosis of diabetes mellitus, were under 60 years of age, had no hematocrit alterations, remained hemodynamically stable during the time of data collection, and were given no ascorbic acid, acetaminophen, dopamine, or mannitol during follow-up. Capillary and serum blood glucose samples were collected simultaneously by finger-stick and venipuncture 2 hours after lunch, by the same observer, who was blinded to the serum glucose results. First, between July and November 2009, capillary glucose levels were measured using the blood glucose meters OneTouch SureStep® and MediSense Optium®. Between November 2009 and February 2010, capillary blood glucose levels were measured on the glucose meters OneTouch SureStep and Optium Xceed®. The capillary glucose readings were analyzed between meters and also in relation to the serum blood glucose values by the t-test for paired samples and the Mood two-sample test.Results: The patients’ mean age was 50.45 years. The blood glucose means obtained using the meters OneTouch SureStep, MediSense Optium, and Optium Xceed were, respectively, 183.87 mg/dL, 178.49 mg/dL, and 192.73 mg/dL, and the mean for the serum glucose values was 174.58 mg/dL. A significant difference was found between the capillary measurements taken by the glucose meters and the serum glucose measurements (P < 0.05, and no significant interdevice difference was found. After stratification of the serum blood glucose values into two groups, below and above 180 mg/dL, the variance found for the glucose meter OneTouch SureStep was statistically greater (P = 0.03 in relation to the serum glucose levels above 180 mg/dL, which was not the case with the glucose meters MediSense Optium (P = 0.06 and Optium Xceed (P = 0.12. The percentage of capillary blood glucose values showing a variation of less than 20% compared with serum values was 64.94% for OneTouch SureStep, 47.83% for Medisense Optium, and 51.61% for Optium Xceed, when serum glucose was greater than 75 mg/dL.Conclusion: The glucose meters tested showed an adequate interdevice correlation in their capillary glucose readings, in addition to correlating with the serum glucose values (ie, if a blood glucose reading is high or low in one test, it is likely to be respectively high or low in another. The means for the capillary blood glucose readings, however, were significantly different from the mean serum glucose. When serum glucose was above 180 mg/dL, there was a greater variance in the capillary measurements on the glucose meter OneTouch SureStep, with less correlation with the serum blood glucose (P < 0.05, which did not occur significantly with the two other glucose meters. On the other hand, OneTouch SureStep had the highest accuracy in relation to serum glucose when the whole sample of serum glucose values above 75 mg/dL was analyzed, considering a variation of less than 20% in the measurements. The three glucose meters provide readings that correlate with the serum glucose values of hospitalized patients. However, one should bear in mind that capillary measurements quite often show more than a 20% variation in relation to serum glucose values, and caution should be exercised in interpreting the readings when serum glucose levels are elevated.Keywords: capillary blood glucose, serum glucose, glucose meters, hospitalized patients

  5. Constrained optimization of Drude's equations eliminates effects of confounding molecules for the polarimetric measurement of glucose.

    Science.gov (United States)

    Güçlü, Burak; Engbretson, Gustav A; Bolanowski, Stanley J

    2004-01-01

    Common confounding factors for polarimetric concentration measurements include additional optical rotations from unknown optically active molecules, linear birefringence of the medium, and path length variability. We show that by approximating Drude's equation and taking several measurements from the same sample at different wavelengths, the error due to confounding rotations in the measurements can theoretically be canceled. The analysis is developed with regard to glucose sensing in aqueous humor. First, we show that the optical rotatory dispersions of the known molecules in bovine aqueous humor could be represented by Drude's equations. Then, the total optical rotation is approximated by a function combining Drude's equations for the major contributors in the sample, i.e., glucose, glutamine, fructose, and phenylalanine. The concentration-related unknown coefficients in the approximating function are found by constrained nonlinear optimization of the function at different wavelengths. This technique is tested on a published data set and four alterations of those data: (1) concentrations randomly varied within narrow limits, (2) similar to alteration 1 but with significantly elevated glucose concentration, (3) similar to alteration 1 but with significantly decreased glucose concentration, and (4) concentrations randomly varied within wider limits than alteration 1. The method produces very accurate glucose-concentration estimates in all of these data sets. The relative error was smaller than 1% in all except the low-glucose sample (1.4%). This method may prove useful in noninvasive glucose measurement in humans. PMID:15447018

  6. Non Invasive Blood Glucose Measurement using NIR technique based on occlusion spectroscopy

    Directory of Open Access Journals (Sweden)

    Prof..Mrs.A.A.Shinde

    2011-12-01

    Full Text Available Diabetes is considered to be one of the major health care epidemics of modern era. The determination of blood glucose concentration using the self monitoring blood glucose devices involves the chemical analysis of blood samples taken by pricking the finger or extracting blood from forearm. The pain, discomfort and inconvenience in the current invasive method has led to the feasibility study of noninvasive measurement techniques. In this paper, an optical method using NIR technique based on occlusion spectroscopy is used whichshows that it can be possible to measure glucose concentration in blood non invasively.

  7. Adaptive Blood Glucose Monitoring and Insulin Measurement Devices for Visually Impaired Persons.

    Science.gov (United States)

    Petzinger, R. A.

    1993-01-01

    This article describes devices that people with visual impairments and diabetes can use to monitor blood glucose levels and measure insulin. A table lists devices, their manufacturers (including address and telephone number), and comments about the devices. (DB)

  8. Design of a mechanical-tunable filter spectrometer for noninvasive glucose measurement.

    Science.gov (United States)

    Saptari, Vidi; Youcef-Toumi, Kamal

    2004-05-01

    The development of an accurate and reliable noninvasive near-infrared (NIR) glucose sensor hinges on the success in addressing the sensitivity and the specificity problems associated with the weak glucose signals and the overlapping NIR spectra. Spectroscopic hardware parameters most relevant to noninvasive blood glucose measurement are discussed, which include the optical throughput, integration time, spectral range, and the spectral resolution. We propose a unique spectroscopic system using a continuously rotating interference filter, which produces a signal-to-noise ratio of the order of 10(5) and is estimated to be the minimum required for successful in vivo glucose sensing. Using a classical least-squares algorithm and a spectral range between 2180 and 2312 nm, we extracted clinically relevant glucose concentrations in multicomponent solutions containing bovine serum albumin, triacetin, lactate, and urea. PMID:15130007

  9. A high sensitivity MEA probe for measuring real time rat brain glucose flux.

    Science.gov (United States)

    Wei, Wenjing; Song, Yilin; Shi, Wentao; Lin, Nansen; Jiang, Tingjun; Cai, Xinxia

    2014-05-15

    The mammalian central nervous system (CNS) relies on a constant supply of external glucose for its undisturbed operation. This article presents an implantable Multi-Electrode Array (MEA) probe for brain glucose measurement. The MEA was implemented on Silicon-On-Insulator (SOI) wafer using Micro-Electro-Mechanical-Systems (MEMS) methods. There were 16 platinum recording sites on the probe and enzyme glucose oxidase (GOx) was immobilized on them. The glucose sensitivity of the MEA probe was as high as 489 µA mM(-1) cm(-2). 1,3-Phenylenediamine (mPD) was electropolymerized onto the Pt recording surfaces to prevent larger molecules such as ascorbic acid (AA), 3,4-dihydroxyphenylacetic acid (DOPAC), serotonin (5-HT), and dopamine (DA) from reaching the recording sites surface. The MEA probe was implanted in the anesthetized rat striatum and responded to glucose levels which were altered by intraperitoneal injection of glucose and insulin. After the in vivo experiment, the MEA probe still kept sensitivity to glucose, these suggested that the MEA probe was reliable for glucose monitoring in brain extracellular fluid (ECF). PMID:24362080

  10. The measurement of the nigrostriatal dopaminergic function and glucose metabolism in patients with movement disorders

    International Nuclear Information System (INIS)

    The nigrostriatal dopaminergic function and glucose metabolism were evaluated in 34 patients with various movement disorders by using positron emission tomography with 18F-Dopa and 18F-FDG respectively. The 18F-Dopa uptake in the striatum (the caudate head and the putamen) decreased in patients with Parkinson's disease but was relatively unaffected in the caudate. The cerebral glucose metabolism was normal in patients with Parkinson's disease. The 18F-Dopa uptake in the striatum also decreased in cases of atypical parkinsonism and in cases of progressive supranuclear palsy, but there was no difference in the uptake between the caudate and the putamen. The glucose metabolism decreased in the cerebral hemisphere including the striatum; this finding was also different from those of Parkinson's disease. A normal 18F-Dopa uptake in the striatum with a markedly decreased striatal glucose metabolism and a mildly decreased cortical glucose metabolism was observed in cases of Huntington's disease and Wilson's disease. The 18F-Dopa uptake in the striatum increased and the glucose metabolism was normal in cases of idiopathic dystonia. Various patterns of 18F-Dopa uptake and glucose metabolism were thus observed in the various movement disorders. These results suggest that the measurements of the 18F-Dopa uptake and the cerebral glucose metabolism would be useful for the evaluation of the strid be useful for the evaluation of the striatal function in various movement disorders. (author)

  11. Continuous Glucose Monitoring

    Science.gov (United States)

    ... or thigh. What is continuous glucose monitoring? Continuous glucose monitoring (CGM) systems use a tiny sensor inserted under the skin ... before making a change in treatment. 2 Continuous Glucose Monitoring CGM systems provide glucose measurements as often as once per ...

  12. Factors Affecting Blood Glucose Monitoring: Sources of Errors in Measurement

    OpenAIRE

    Ginsberg, Barry H

    2009-01-01

    Glucose monitoring has become an integral part of diabetes care but has some limitations in accuracy. Accuracy may be limited due to strip manufacturing variances, strip storage, and aging. They may also be due to limitations on the environment such as temperature or altitude or to patient factors such as improper coding, incorrect hand washing, altered hematocrit, or naturally occurring interfering substances. Finally, exogenous interfering substances may contribute errors to the system eval...

  13. Measurement delay associated with the Guardian® RT continuous glucose monitoring system

    Science.gov (United States)

    Wei, C; Lunn, D J; Acerini, C L; Allen, J M; Larsen, A M; Wilinska, M E; Dunger, D B; Hovorka, R

    2010-01-01

    Aims Using compartment modelling, we assessed the time delay between blood glucose and sensor glucose measured by the Guardian® RT continuous glucose monitoring system in young subjects with Type 1 diabetes (T1D). Methods Twelve children and adolescents with T1D treated by continuous subcutaneous insulin infusion (male/female 7/5; age 13.1 ± 4.2 years; body mass index 21.9 ± 4.3 kg/m2; mean ± sd) were studied over 19 h in a Clinical Research Facility. Guardian® RT was calibrated every 6 h and sensor glucose measured every 5 min. Reference blood glucose was measured every 15 min using a YSI 2300 STAT Plus Analyser. A population compartment model of sensor glucose–blood glucose kinetics was adopted to estimate the time delay, the calibration scale and the calibration shift. Results The population median of the time delay was 15.8 (interquartile range 15.2, 16.5) min, which was corroborated by correlation analysis between blood glucose and 15-min delayed sensor glucose. The delay has a relatively low intersubject variability, with 95% of individuals predicted to have delays between 10.4 and 24.3 min. Population medians (interquartile range) for the scale and shift are 0.800 (0.777, 0.823) (unitless) and 1.66 (1.47, 1.84) mmol/l, respectively. Conclusions In young subjects with T1D, the total time delay associated with the Guardian® RT system was approximately 15 min. This is twice that expected on physiological grounds, suggesting a 5- to 10-min delay because of data processing. Delays above 25 min are rarely to be observed. PMID:20121899

  14. Quantitative measurement of glucose utilization in dog brain using positron emission tomogram and 18FDG

    International Nuclear Information System (INIS)

    Recent development of positron emission tomography and fluorine-18 labeled deoxy-glucose has enabled us to observe in vivo metabolism of glucose. For the application to human study, the method originally developed by Sokoloff et al. in rat brain was performed in dog brain using ECAT II in order to measure cerebral metabolic rate of glucose. Cross calibration between ECAT II and well counter was performed using phantom imaging and positron emmiter (Ga-68). Plasma 18-FDG was measured in well counter and calibrated. Cerebral metabolic rate of glucose (mg/100g brain.min) was calculated using ECAT images of 18-FDG and integrated activity of plasma 18-FDG from injection time (zero) to imaging time (t). 14.5mg/100g brain.min and 14.2mg/100g brain.min were obtained in frontal cortex and occipital cortex in anesthetized dog. (author)

  15. Ex vivo optical measurements of glucose diffusion kinetics in native and diabetic mouse skin.

    Science.gov (United States)

    Tuchina, Daria K; Shi, Rui; Bashkatov, Alexey N; Genina, Elina A; Zhu, Dan; Luo, Qingming; Tuchin, Valery V

    2015-04-01

    The aim of this study was to estimate the glucose diffusion coefficients ex vivo in skin of mice with diabetes induced in vivo by alloxan in comparison to non-diabetic mice. The temporal dependences of collimated transmittance of tissue samples immersed in glucose solutions were measured in the VIS-NIR spectral range to quantify the glucose diffusion/permeability coefficients and optical clearing efficiency of mouse skin. The average thickness of intact healthy and diabetic skin was 0.023 ± 0.006 cm and 0.019 ± 0.005 cm, respectively. Considerable differences in optical and kinetic properties of diabetic and non-diabetic skin were found: clearing efficiency was 1.5-fold better and glucose diffusivity was 2-fold slower for diabetic skin. Experimental Setup for measuring collimated transmittance spectra of mouse skin samples. PMID:25760425

  16. Amplitude and time measurement ASIC with analog derandomization

    International Nuclear Information System (INIS)

    A versatile 32-channel ASIC has been developed for accurate processing of high-rate pulse signals from highly segmented detectors. In contrast to conventional approaches, this circuit affords a dramatic reduction in data volume through the use of analog techniques (precision peak detectors and time-to-amplitude converters) together with fast arbitration and sequencing logic to concentrate the data before digitization. In operation the circuit functions like a data-driven analog first-in, first-out (FIFO) memory between the preamplifiers and the ADC. Peak amplitudes of pulses arriving at any one of the 32 inputs are sampled, stored, and queued for readout and digitization through a single output port. Hit timing, pulse risetime, and channel address are also available at the output. Prototype chips have been fabricated in 0.35 ?m CMOS and tested. Amplitude accuracy of the peak detect and hold circuit is 0.2% (absolute) and 0.04% (nonlinearity) for signals within 0.3 V of either supply rail. Time walk is below 5 ns, droop rate is 250 mV/s, and power consumption is less than 2 mW/channel at pulse rates up to 500 kHz per channel

  17. In vitro measurements of physiological glucose concentrations in biological fluids using mid-infrared light

    OpenAIRE

    Liakat, Sabbir; Bors, Kevin A.; Huang, Tzu-Yung; Michel, Anna P. M.; Zanghi, Eric; Gmachl, Claire F.

    2013-01-01

    Mid-infrared transmission spectroscopy using broadband mid-infrared or Quantum Cascade laser sources is used to predict glucose concentrations of aqueous and serum solutions containing physiologically relevant amounts of glucose (50-400 mg/dL). We employ partial least squares regression to generate a calibration model using a subset of the spectra taken and to predict concentrations from new spectra. Clinically accurate measurements with respect to a Clarke error grid were made for concentrat...

  18. Insulin analogs

    Directory of Open Access Journals (Sweden)

    Emily Chu

    2012-06-01

    Full Text Available The fear of hypoglycemia that people with diabetes experience is a factor in non-adherence to insulin therapy, which can adversely affect glycemic control and increase the risk of diabetes-associated complications. Insulin analogs are modified forms of human insulin designed to mimic endogenous insulin secretion, and may therefore help to reduce the risk and severity of hypoglycemia. While much evidence exists to demonstrate the efficacy of insulin analogs in blood glucose control, the effects on the incidence of severe hypoglycemia are less clear. This treatment review presents recent studies investigating the effects of insulin analogs on the frequency of hypoglycemia.

  19. Wavelength-modulated differential laser photothermal radiometry for blood glucose measurements

    Energy Technology Data Exchange (ETDEWEB)

    Guo, X; Mandelis, A; Matvienko, A; Sivagurunathan, K [Department of MIE, University Toronto, 5 King' s College Road, Toronto, ON M5S 3G8 (Canada); Zinman, B, E-mail: guox@mie.utoronto.c [Samuel Luenfeld Research Institute, Mount Sinai Hospital, University of Toronto, 60 Murray Street, Toronto, ON M5T 3L9 (Canada)

    2010-03-01

    A Wavelength-Modulated Differential Laser Photothermal Radiometer (WM-DPTR) technique was used for non-invasive blood glucose monitoring in the mid-IR range, where the prominent absorption peak is glucose specific and isolated from other interfering peaks in human blood. The WM-DPTR method consists of the out-of-phase modulated excitation at two discrete wavelengths 9.5 {mu}m and 10.4 {mu}m (near the peak and the baseline of glucose absorption), generated from two quantum cascade lasers (QCL) and the differential emission detection through a thermal-wave upconversion process via a HgCdZnTe (MCZT) detector (2-5 {mu}m). The differential method suppresses the background signal and reduces source-detection interference, thus enhancing glucose detection sensitivity. The results from aqueous glucose phantom (0-440 mg/dl) measurements demonstrate that both amplitude and phase of the WM-DPTR signal can be used for glucose detection. The dynamic range and the sensitivity of the glucose detection are influenced greatly by the laser intensity ratio and modulation frequency. The optimal intensity ratio for high sensitivity is {approx}1. Other laser intensity ratios increase dynamic range but reduce sensitivity. Sensitivity increases with frequency.

  20. Wavelength-modulated differential laser photothermal radiometry for blood glucose measurements

    International Nuclear Information System (INIS)

    A Wavelength-Modulated Differential Laser Photothermal Radiometer (WM-DPTR) technique was used for non-invasive blood glucose monitoring in the mid-IR range, where the prominent absorption peak is glucose specific and isolated from other interfering peaks in human blood. The WM-DPTR method consists of the out-of-phase modulated excitation at two discrete wavelengths 9.5 ?m and 10.4 ?m (near the peak and the baseline of glucose absorption), generated from two quantum cascade lasers (QCL) and the differential emission detection through a thermal-wave upconversion process via a HgCdZnTe (MCZT) detector (2-5 ?m). The differential method suppresses the background signal and reduces source-detection interference, thus enhancing glucose detection sensitivity. The results from aqueous glucose phantom (0-440 mg/dl) measurements demonstrate that both amplitude and phase of the WM-DPTR signal can be used for glucose detection. The dynamic range and the sensitivity of the glucose detection are influenced greatly by the laser intensity ratio and modulation frequency. The optimal intensity ratio for high sensitivity is ?1. Other laser intensity ratios increase dynamic range but reduce sensitivity. Sensitivity increases with frequency.

  1. Noninvasive optical polarimetric glucose sensing using a true phase measurement technique.

    Science.gov (United States)

    Coté, G L; Fox, M D; Northrop, R B

    1992-07-01

    The focus of this paper was to describe the development and testing of a noninvasive true phase optical polarimetry sensing system to monitor in vivo glucose concentrations. To demonstrate the applicability of this optical sensor for glucose measurement, we first calibrated the system and then tested it in vitro using both a glass test cell filled with glucose solution in the physiologic range, with a path length of 0.9 cm to approximate one centimeter path length present in the anterior chamber of the eye, and then on an excised human eye. Our technique used helium neon laser light which was coupled through a rotating linear polarizer along with two stationary linear polarizers and two detectors to produce reference and signal outputs whose amplitudes varied sinusoidally with a frequency of twice the angular velocity of the rotating polarizer, and whose phase was proportional to the rotation of the linear polarization vector passing through the glucose solution. PMID:1516942

  2. Simulation study of in vitro glucose measurement by NIR spectroscopy and a method of error reduction

    Science.gov (United States)

    Tarumi, Masatoshi; Shimada, Mitsunori; Murakami, Tomoya; Tamura, Mamoru; Shimada, Miho; Arimoto, Hidenobu; Yamada, Yukio

    2003-08-01

    The effects of some important factors on the blood glucose measurements by NIR spectroscopy are investigated by numerical simulation, and a method is proposed to significantly reduce the prediction errors induced by these effects. The changes in the absorbance spectra with the changes in the glucose concentration, temperature and scattering characteristics of background tissue are obtained by a Monte Carlo simulation of light propagation for the wavelength range from 1200 nm to 1800 nm. The glucose concentration is predicted by applying a multivariate analysis to the numerically simulated spectra. This process estimates the errors in the prediction of the glucose concentration induced by the temperature and scattering changes. It has been found that only 1 °C change in the temperature or only 1% change in the scattering coefficient induces about 500 mg dl-1 or 300 mg dl-1 errors, respectively, in the prediction of the glucose concentration. These errors can be significantly reduced to less than 20 mg dl-1 of the glucose concentration by incorporating the effects of the temperature and scattering characteristics on the spectra to the multivariate analysis.

  3. Measurement of the incretin hormones : glucagon-like peptide-1 and glucose-dependent insulinotropic peptide

    DEFF Research Database (Denmark)

    Kuhre, Rune Ehrenreich; Wewer Albrechtsen, Nicolai Jacob

    2015-01-01

    The two incretin hormones, glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP), are secreted from the gastrointestinal tract in response to meals and contribute to the regulation of glucose homeostasis by increasing insulin secretion. Assessment of plasma concentrations of GLP-1 and GIP is often an important endpoint in both clinical and preclinical studies and, therefore, accurate measurement of these hormones is important. Here, we provide an overview of current approaches for the measurement of the incretin hormones, with particular focus on immunological methods.

  4. Measurement of the Incretin Hormones: Glucagon-Like Peptide-1 and Glucose-Dependent Insulinotropic Peptide

    DEFF Research Database (Denmark)

    Kuhre, Rune Ehrenreich; Wewer Albrechtsen, Nicolai Jacob

    2015-01-01

    The two incretin hormones, glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic peptide (GIP), are secreted from the gastrointestinal tract in response to meals and contribute to the regulation of glucose homeostasis by increasing insulin secretion. Assessment of plasma concentrations of GLP-1 and GIP is often an important endpoint in both clinical and preclinical studies and, therefore, accurate measurement of these hormones is important. Here, we provide an overview of current approaches for the measurement of the incretin hormones, with particular focus on immunological methods.

  5. Evaluation of measurement sites for noninvasive blood glucose sensing with near-infrared transmission spectroscopy.

    Science.gov (United States)

    Burmeister, J J; Arnold, M A

    1999-09-01

    Six putative measurement sites were evaluated for noninvasive sensing of blood glucose by first-overtone near-infrared spectroscopy. The cheek, lower lip, upper lip, nasal septum, tongue, and webbing tissue between the thumb and forefinger were examined. These sites were evaluated on the basis of their chemical and physical properties as they pertain to the noninvasive measurement of glucose. Critical features included the effective optical pathlength of aqueous material within the tissue and the percentage of body fat within the optical path. Aqueous optical paths of 5 mm are required to measure clinically relevant concentrations of glucose in the first-overtone region. All of the tested sites met this requirement. The percentage of body fat affects the signal-to-noise ratio of the measurement and must be minimized for reliable glucose sensing. The webbing tissue contains a considerable amount of fat tissue and is clearly the worse measurement site. All other sites possess substantially less fat, with the least amount of fat in tongue tissue. For this reason, the tongue provides spectra with the highest signal-to-noise ratio and is, therefore, the site of choice on the basis of spectral quality. PMID:10471677

  6. Development of reconfigurable analog and digital circuits for plasma diagnostics measurement systems

    International Nuclear Information System (INIS)

    In long pulse discharge tokamak, a large number of diagnostic channels are being used to understand the complex behavior of plasma. Different diagnostics demand different types of analog and digital processing for plasma parameters measurement. This leads to variable requirements of signal processing for diagnostic measurement. For such types of requirements, we have developed hardware with reconfigurable electronic devices, which provide flexible solution for rapid development of measurement system. Here the analog processing is achieved by Field Programmable Analog Array (FPAA) integrated circuit while reconfigurable digital devices (CPLD/FPGA) achieve digital processing. FPAA's provide an ideal integrated platform for implementing low to medium complexity analog signal processing. With dynamic reconfigurability, the functionality of the FPAA can be reconfigured in-system by the designer or on the fly by a microprocessor. This feature is quite useful to manipulate the tuning or the construction of any part of the analog circuit without interrupting operation of the FPAA, thus maintaining system integrity. The hardware operation control logic circuits are configured in the reconfigurable digital devices (CPLD/FPGA) to control proper hardware functioning. These reconfigurable devices provide the design flexibility and save the component space on the board. It also provides the flexibility for various setting through software. The circuit controlling commands are eitheThe circuit controlling commands are either issued by computer/processor or generated by circuit itself. (author)

  7. Classification of diabetes and measurement of blood glucose concentration noninvasively using near infrared spectroscopy

    Science.gov (United States)

    Li, Zhe; Li, Gang; Yan, Wen-Juan; Lin, Ling

    2014-11-01

    Developing noninvasive blood glucose monitoring method is an to immense need to alleviate the pain and suffering of diabetics associated with the frequent pricking of skin for taking blood sample. A hybrid algorithm for multivariate calibration is proposed to improve the prediction performance of classification of diabetes and measurement of blood glucose concentration by near infrared (NIR) spectroscopy noninvasively. The algorithm is based on wavelet prism modified uninformative variable elimination approach (WP-mUVE) combined with least squares support vector machine (LSSVM), named as WP-mUVE-LSSVM. The method is successfully applied to diabetic classification experiment (in vivo) and blood glucose concentration measurement experiment (in vivo) respectively. Human tongue is selected as the measuring site in this study. To evaluate effectiveness of pretreatment method and quality of calibration models, several usually used pretreatment methods and kernel functions of LSSVM are introduced comparing with our method. Higher quality data is obtained by our pretreatment method owing to the elimination of varying background and noise of spectra data simultaneously. Better prediction accuracy and adaptability are obtained by LSSVM model with radial basis kernel function. The results indicate that WP-mUVE-LSSVM holds promise for the classification of diabetes and measurement of blood glucose concentration noninvasively based on human tongue using NIR spectroscopy.

  8. Measure and category a survey of the analogies between topological and measure spaces

    CERN Document Server

    Oxtoby, John C

    1980-01-01

    In this edition, a set of Supplementary Notes and Remarks has been added at the end, grouped according to chapter. Some of these call attention to subsequent developments, others add further explanation or additional remarks. Most of the remarks are accompanied by a briefly indicated proof, which is sometimes different from the one given in the reference cited. The list of references has been expanded to include many recent contributions, but it is still not intended to be exhaustive. John C. Oxtoby Bryn Mawr, April 1980 Preface to the First Edition This book has two main themes: the Baire category theorem as a method for proving existence, and the "duality" between measure and category. The category method is illustrated by a variety of typical applications, and the analogy between measure and category is explored in all of its ramifications. To this end, the elements of metric topology are reviewed and the principal properties of Lebesgue measure are derived. It turns out that Lebesgue integration is not es...

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

    Science.gov (United States)

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

    2013-06-01

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

  10. Evaluation of the Efficacy and Correlation between Blood Glucose Measured Using Glucometers and Enzymatic Laboratory Methods

    Directory of Open Access Journals (Sweden)

    Rasouli R

    2012-01-01

    Full Text Available Background and Objectives: Diabetes Mellitus (DM is the most common chronic metabolic disease, with many complications including renal failure, blindness and non-traumatic amputation, so it is important to monitor and regulate blood glucose. Considering how easy home blood glucose monitoring is, we decided to evaluate the performance of two available glucometers for detection of blood glucose compared with standard laboratory methods.Methods: In this analytical study, we compared the capillary blood glucose levels of 60 volunteers with mean age of 32.8±9.6 years in Tabriz Mehr Laboratory as determined by test strips (two different Glucometers with venous blood glucose levels’ measurements by the enzymatic method (the standard laboratory kit. Data were analyzed using one way-ANOVA test, T-test, Pearson correlation and Bland and Altman plot.Results: The mean differences of No: 1 and No: 2 Glucometers with enzymatic laboratory method were 20.78±11.61 and 4.5±3.76mg/dl respectively. The one way ANOVA test indicated significant differences between three methods (p<0.05. Further Duncan's test revealed significant differences between two devices (p=0.001 and device No.1 and laboratory method (p=0.001; however, the differences between device No.2 and laboratory method were not statistically significant (p=0.83. Conclusion: According to the results, calibrating the devices with laboratory instruments in order to make major clinical decisions is recommended.

  11. Glucose transport in human erythrocytes measured using 13C NMR spin transfer

    International Nuclear Information System (INIS)

    The authors present the results of a new NMR-based procedure for measuring the fast transmembrane exchange of D-[1-13C]glucose in human erythrocytes. The method relies on different rates of exchange between the ?- and ?-anomers of glucose inside and outside the cells; the rate outside the cells is greatly increased by the addition of mutarotase to the suspension. Theory is developed to describe nuclear-spin transfer in the present system and is used to analyse the data to yield estimates of transmembrane-exchange rate constants and their statistical uncertainties. For a total glucose concentration of 25.5 mmol/l at 400C the first order efflux rate constants for the ?- and ?-anomers were 1.20 ± 0.40 s-1 and 0.71 ± 0.30 s-1, respectively. 17 refs.; 4 figs

  12. Precision magnetic measurements by the floating wire analog technique

    International Nuclear Information System (INIS)

    Two SuperHILAC magnetic spectrometers were calibrated by means of current-carrying, floating wires. An effective radius-of-curvature as a function of single position measurements of magnetic-induction was determined with a probable error of +-0.02% over the range of rigidity: 0.3 less than or equal to B rho less than or equal to 2.4 (Tesla-meters). Employed in the calibrations were: optical detectors for determining wire position, an eddy-current jiggler for reducing pulley stiction, a vacuum re-entrant tube for allowing calibration under spectrometer operating conditions, two-axis gradient correction coils for operating an NMR magnetometer in gradients of 70 Gauss/cm, a calculator program for facilitating data collection, and a computer program for data reduction and presentation

  13. Measurement of glucose utilization by Pseudomonas fluorescens that are free-living and that are attached to surfaces

    International Nuclear Information System (INIS)

    The assimilation and respiration of glucose by attached and free-living Pseudomonas fluorescens were compared. The attachment surfaces were polyvinylidene fluoride, polyethylene, and glass. Specific uptake of [1C]glucose was determined after bacterial biomass was measured by (1) microscopic counts or (2) prelabelling of cells by providing [3H]leucine as substrate, followed by dual-labelling scintillation counting. The glucose concentration was 1.4, 3.5, 5.5, 7.6, or 9.7 ?M. Glucose assimilation by cells which became detached from the surfaces during incubation with glucose was also measured after the detached cells were collected by filtration. The composition of the substratum had no effect on the amount of glucose assimilated by attached cells. Glucose assimilation by attached cells exceeded that by free-living cells by a factor of between 2 and 5 or more, and respiration of glucose by surface-associated cells was greater than that by free-living bacteria. Glucose assimilation by detached cells was greater than that by attached bacteria. Measurements of biomass by microscopic counts gave more consistent results than those obtained with dual-labelling, but in general, results obtained by both methods were corroborative

  14. Development of portable health monitoring system for automatic self-blood glucose measurement

    Science.gov (United States)

    Kim, Huijun; Mizuno, Yoshihumi; Nakamachi, Eiji; Morita, Yusuke

    2010-02-01

    In this study, a new HMS (Health Monitoring System) device is developed for diabetic patient. This device mainly consists of I) 3D blood vessel searching unit and II) automatic blood glucose measurement (ABGM) unit. This device has features such as 1)3D blood vessel location search 2) laptop type, 3) puncturing a blood vessel by using a minimally invasive micro-needle, 4) very little blood sampling (10?l), and 5) automatic blood extraction and blood glucose measurement. In this study, ABGM unit is described in detail. It employs a syringe type's blood extraction mechanism because of its high accuracy. And it consists of the syringe component and the driving component. The syringe component consists of a syringe itself, a piston, a magnet, a ratchet and a micro-needle whose inner diameter is about 80?m. And the syringe component is disposable. The driving component consists of body parts, a linear stepping motor, a glucose enzyme sensor and a slider for accurate positioning control. The driving component has the all-in-one mechanism with a glucose enzyme sensor for compact size and stable blood transfer. On designing, required thrust force to drive the slider is designed to be greater than the value of the blood extraction force. Further, only one linear stepping motor is employed for blood extraction and transportation processes. The experimental result showed more than 80% of volume ratio under the piston speed 2.4mm/s. Further, the blood glucose was measured successfully by using the prototype unit. Finally, the availability of our ABGM unit was confirmed.

  15. Investigation of 18F-2-deoxyglucose for the measure of myocardial glucose metabolism

    International Nuclear Information System (INIS)

    18F labeled 2-deoxyglucose (18FDG) was studied as a glucose analog. Myocardial uptake and retention, blood clearance, species (dog, monkey, man) dependence and effect of diet on uptake were investigated. Normal myocardial uptake of 18FDG was 3 to 4% in dog and monkey and 1 to 4% of injected dose in man compared to brain uptake of 2% in dog, 5 to 6% in monkey and 4 to 8% in man. The metabolic rate (MR) for glucose in non-fasting (glycolytic state) was 2.8 times greater than in fasting (ketogenic state). Human subjects showed higher myocardial uptake after a normal meal than after meal containing mostly free fatty acids (FFA). Blood clearance was rapid with initial clearance t1/2 of 0.2 to 0.3 min followed by a t1/2 of 8.4 +- 1.2 min in dog and 11.6 +- 1.1 min in man. A small third component had a t1/2 of 59 +- 10 min and 88 +- 4 min in dog and man, respectively. High image contrast ratios between heart and blood (dog 3.5/1; man 14/1), heart and lung (dog 9/1; man 20/1), heart and liver (dog 15/1; man 10/1) were found with the ECAT positron tomograph. 18FDG was found to be rapidly taken up by the myocardium without any significant tissue clearance over a 4 hour period. 18FDG is transported, phosphorylated to 18FDG-6-PO4 and trapped in myocardial cells in the same manner as has been found for brain and exhibits excellent imaging properties. Determination of glucose and FFA MR in vivo with ECT provides a method for investigation and assessment of changing aerobic and anaerobic metabolic rates in ischemic heart disease in man

  16. H-2g, a glucose analog of blood group H antigen, mediates monocyte recruitment in vitro and in vivo via IL-8/CXCL8

    Directory of Open Access Journals (Sweden)

    Rabquer BJ

    2012-09-01

    Full Text Available Bradley J Rabquer,1,2 Yong Hou,1 Jeffrey H Ruth,1 Wei Luo,1 Daniel T Eitzman,1 Alisa E Koch,3,1 Mohammad A Amin11University of Michigan Medical School, Department of Internal Medicine, Ann Arbor, MI, USA; 2Albion College, Biology Department, Albion, MI, USA; 3VA Medical Service, Department of Veterans Affairs, Ann Arbor, MI, USAObjective: Monocyte (MN recruitment is an essential inflammatory component of many autoimmune diseases, including rheumatoid arthritis (RA. In this study we investigated the ability of 2-fucosyllactose (H-2g, a glucose analog of blood group H antigen to induce MN migration in vivo and determined if H-2g-induced interleukin-8 (IL-8/CXCL8 plays a role in MN ingress in RA.Methods: Sponge granuloma and intravital microscopy assays were performed to examine H-2g-induced in vivo MN migration and rolling, respectively. MNs were stimulated with H-2g, and the production of IL-8/CXCL8 was assessed by enzyme-linked immunosorbent assay and quantitative polymerase chain reaction. Lastly, in vitro MN migration assays and an in vivo RA synovial tissue severe combined immunodeficiency mouse model were used to determine the role of IL-8/CXCL8 in H-2g-induced MN migration.Results: In vivo, H-2g induced significantly greater MN migration compared to phosphate buffered saline. Intravital microscopy revealed that H-2g mediates MN migration in vivo by inducing MN rolling. In addition, H-2g induced MN production of IL-8/CXCL8, a process that was dependent on Src kinase. Moreover, we found that H-2g mediated MN migration in vitro, and in vivo migration was inhibited by a neutralizing anti-IL-8/CXCL8 antibody.Conclusion: These findings suggest that H-2g mediates MN recruitment in vitro and in vivo (in part via IL-8/CXCL8.Keywords: inflammation, rheumatoid arthritis, chemokine, migration

  17. Noninvasive measurement of regional myocardial glucose metabolism by positron emission computed tomography

    International Nuclear Information System (INIS)

    While the results of regional myocardial glucose metabolism measurements using positron emission computed tomography (13N-ammonia) are promising, their utility and value remains to be determined in man. If this technique can be applied to patients with acute myocardial ischemia or infarction it may permit delineation of regional myocardial segments with altered, yet still active metabolism. Further, it may become possible to evaluate the effects of interventions designed to salvage reversibly injured myocardium by this technique

  18. Angular measurements of light scattered by the glucose containing biological tissues and their phantoms

    Science.gov (United States)

    Domnin, K. G.; Cherevatenko, G. A.; Aksenov, E. T.

    2014-10-01

    Method of optical polarimetry is well known, but earlier it was mainly used to low scattering media. In this paper we consider the possibility of measuring the glucose concentration by detecting polarization of the backscattered laser light. Dependencies of the degree of polarization and of the optical rotation on the registration angle were received. Furthermore, the significant impact of the wavelength and the power of probing beam on the degree of polarization was shown.

  19. Evaluation of the Efficacy and Correlation between Blood Glucose Measured Using Glucometers and Enzymatic Laboratory Methods

    Directory of Open Access Journals (Sweden)

    R Rasouli

    2012-05-01

    Full Text Available

    Background and Objectives: Diabetes Mellitus (DM is the most common chronic metabolic disease, with many complications including renal failure, blindness and non-traumatic amputation, so it is important to monitor and regulate blood glucose. Considering how easy home blood glucose monitoring is, we decided to evaluate the performance of two available glucometers for detection of blood glucose compared with standard laboratory methods.

     

    Methods: In this analytical study, we compared the capillary blood glucose levels of 60 volunteers with mean age of 32.8±9.6 years in Tabriz Mehr Laboratory as determined by test strips (two different Glucometers with venous blood glucose levels’ measurements by the enzymatic method (the standard laboratory kit. Data were analyzed using one way-ANOVA test, T-test, Pearson correlation and Bland and Altman plot.

     

    Results: The mean differences of No: 1 and No: 2 Glucometers with enzymatic laboratory method were 20.78±11.61 and 4.5±3.76mg/dl respectively. The one way ANOVA test indicated significant differences between three methods (p<0.05. Further Duncan's test revealed significant differences between two devices (p=0.001 and device No.1 and laboratory method (p=0.001; however, the differences between device No.2 and laboratory method were not statistically significant (p=0.83.

     

    Conclusion: According to the results, calibrating the devices with laboratory instruments in order to make major clinical decisions is recommended.

  20. The characteristic time of glucose diffusion measured for muscle tissue at optical clearing

    International Nuclear Information System (INIS)

    The study of agent diffusion in biological tissues is very important to understand and characterize the optical clearing effects and mechanisms involved: tissue dehydration and refractive index matching. From measurements made to study the optical clearing, it is obvious that light scattering is reduced and that the optical properties of the tissue are controlled in the process. On the other hand, optical measurements do not allow direct determination of the diffusion properties of the agent in the tissue and some calculations are necessary to estimate those properties. This fact is imposed by the occurrence of two fluxes at optical clearing: water typically directed out of and agent directed into the tissue. When the water content in the immersion solution is approximately the same as the free water content of the tissue, a balance is established for water and the agent flux dominates. To prove this concept experimentally, we have measured the collimated transmittance of skeletal muscle samples under treatment with aqueous solutions containing different concentrations of glucose. After estimating the mean diffusion time values for each of the treatments we have represented those values as a function of glucose concentration in solution. Such a representation presents a maximum diffusion time for a water content in solution equal to the tissue free water content. Such a maximum represents the real diffusion time of glucose in the muscle and with this value we could calculate the corresponding diffusion coefficient. (paper)

  1. Estimation of utility values from visual analog scale measures of health in patients undergoing cardiac surgery

    DEFF Research Database (Denmark)

    Oddershede, Lars; Andreasen, Jan Jesper

    2014-01-01

    In health economic evaluations, mapping can be used to estimate utility values from other health outcomes in order to calculate quality adjusted life-years. Currently, no methods exist to map visual analog scale (VAS) scores to utility values. This study aimed to develop and propose a statistical algorithm for mapping five dimensions of health, measured on VASs, to utility scores in patients suffering from cardiovascular disease.

  2. Research and development of a differential laser polarimeter to measure the glucose concentration in turbid media

    Science.gov (United States)

    Cherevatenko, Galina A.; Aksenov, Evgenii T.

    2014-01-01

    Method of optical polarimetry is well known, but earlier it was mainly used to low scattering media. In this paper we consider the possibility of measuring the glucose concentration by detecting polarization of the backscattered laser light. As object of research a human finger have been chosen. The optimal parameters of the probing light were identified, degree of polarization of light scattered by human skin and model objects was registered. A laboratory model of a differential polarimeter, which allows to register the parameters of the polarized radiation scattered by human skin and glucose containing models, was developed. Using the developed polarimeter, model and full-scale experiments were carried out. In the model experiments we investigated the light backscattered by the following objects: a 20% solution of milk and a 50% suspension of human blood. During experiments it was shown, that the amount of optical rotation is also dependent on the angle of registration and, hence, photodetectors position in space is important. The ability of the developed sensor to noninvasively detect the concentration of glucose in the blood was demonstrated. However, its sensitivity to the structure of human skin and the individual characteristics of the organism was identified. This suggests that in order to achieve maximum accuracy it is necessary to carry out individual adjustment and calibration of measuring equipment.

  3. Simultaneous measurement of blood flow and glucose metabolism by autoradiographic techniques

    Energy Technology Data Exchange (ETDEWEB)

    Mies, G.; Niebuhr, I.; Hossmann, K.A.

    A double tracer autoradiographic technique using 131I-iodo-antipyrine and 14C-deoxyglucose is presented for the simultaneous measurement of blood flow and cerebral glucose utilization in the same animal. 131I is a gamma emitting isotope with a half life of 8.06 days and can be detected with adequate resolution on standard autoradiographic films. Autoradiograms are made before and after decay of 131I; the time interval between the 2 exposures and the concentration of the 2 tracers is adjusted to avoid significant cross-contamination. In this way, 2 film exposures are obtained which can be processed quantitatively like single tracer autoradiograms. The validity of the method for the investigation of local coupling of flow and metabolism was tested under various physiological and pathophysiological conditions. Coupling was tight in barbiturate-anesthetized healthy animals, but not under halothane anesthesia where uncoupling occurred in various subcortical structures. Focal seizures induced by topical application of penicillin on the cortical surface led to a coupled increase of metabolism and flow in thalamic relay nuclei but not at the site of penicillin administration where increased glucose utilization was not accompanied by similar increase in blood flow. Both coupled and uncoupled increases in local glucose utilization were observed in spreading depression and in circumscribed areas of experimental brain tumors. The results obtained demonstrate that double tracer autoradiography allows allows the very precise local assessment of cerebral blood flow and glucose utilization, and, therefore, is particularly suited to the study of regional coupling processes under various experimental conditions.

  4. Simultaneous measurement of blood flow and glucose metabolism by autoradiographic techniques

    International Nuclear Information System (INIS)

    A double tracer autoradiographic technique using 131I-iodo-antipyrine and 14C-deoxyglucose is presented for the simultaneous measurement of blood flow and cerebral glucose utilization in the same animal. 131I is a gamma emitting isotope with a half life of 8.06 days and can be detected with adequate resolution on standard autoradiographic films. Autoradiograms are made before and after decay of 131I; the time interval between the 2 exposures and the concentration of the 2 tracers is adjusted to avoid significant cross-contamination. In this way, 2 film exposures are obtained which can be processed quantitatively like single tracer autoradiograms. The validity of the method for the investigation of local coupling of flow and metabolism was tested under various physiological and pathophysiological conditions. Coupling was tight in barbiturate-anesthetized healthy animals, but not under halothane anesthesia where uncoupling occurred in various subcortical structures. Focal seizures induced by topical application of penicillin on the cortical surface led to a coupled increase of metabolism and flow in thalamic relay nuclei but not at the site of penicillin administration where increased glucose utilization was not accompanied by similar increase in blood flow. Both coupled and uncoupled increases in local glucose utilization were observed in spreading depression and in circumscribed areas of experimental brain tumors. The results obtained demonstrate that double tracer auobtained demonstrate that double tracer autoradiography allows allows the very precise local assessment of cerebral blood flow and glucose utilization, and, therefore, is particularly suited to the study of regional coupling processes under various experimental conditions

  5. Method for measurement of glucose enrichment in serum using isotope dilution mass spectrometry and its application for measurement of glucose kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Dan, P.; Clemons, P.M.; Sperling, M.I.; Gelfand, M.J.; Chen, I.W.; Sperling, M.A.; Norman, E.J.

    1983-01-01

    An isotope dilution mass spectrometric method has been developed for kinetic studies of D-glucose in humans, using 6,6-dideuteroglucose as the internal standard. Glucose in plasma samples was purified by anion and cation exchange column chromatography after deproteinization and derivatized to ..cap alpha..-D-glucofuranose cyclic 1,2:3,5-bis (butylboronate)-6-acetate.

  6. Performance Measurement of a Multi-Level/Analog Ferroelectric Memory Device Design

    Science.gov (United States)

    MacLeod, Todd C.; Phillips, Thomas A.; Ho, Fat D.

    2007-01-01

    Increasing the memory density and utilizing the unique characteristics of ferroelectric devices is important in making ferroelectric memory devices more desirable to the consumer. This paper describes the characterization of a design that allows multiple levels to be stored in a ferroelectric based memory cell. It can be used to store multiple bits or analog values in a high speed nonvolatile memory. The design utilizes the hysteresis characteristic of ferroelectric transistors to store an analog value in the memory cell. The design also compensates for the decay of the polarization of the ferroelectric material over time. This is done by utilizing a pair of ferroelectric transistors to store the data. One transistor is used a reference to determinethe amount of decay that has occurred since the pair was programmed. The second transistor stores the analog value as a polarization value between zero and saturated. The design allows digital data to be stored as multiple bits in each memory cell. The number of bits per cell that can be stored will vary with the decay rate of the ferroelectric transistors and the repeatability of polarization between transistors. This paper presents measurements of an actual prototype memory cell. This prototype is not a complete implementation of a device, but instead, a prototype of the storage and retrieval portion of an actual device. The performance of this prototype is presented with the projected performance of the overall device. This memory design will be useful because it allows higher memory density, compensates for the environmental and ferroelectric aging processes, allows analog values to be directly stored in memory, compensates for the thermal and radiation environments associated with space operations, and relies only on existing technologies.

  7. Precision analog signal processor for beam position measurements in electron storage rings

    International Nuclear Information System (INIS)

    Beam position monitors (BPM) in electron and positron storage rings have evolved from simple systems composed of beam pickups, coaxial cables, multiplexing relays, and a single receiver (usually a analyzer) into very complex and costly systems of multiple receivers and processors. The older may have taken minutes to measure the circulating beam closed orbit. Today instrumentation designers are required to provide high-speed measurements of the beam orbit, often at the ring revolution frequency. In addition the instruments must have very high accuracy and resolution. A BPM has been developed for the Advanced Light Source (ALS) in Berkeley which features high resolution and relatively low cost. The instrument has a single purpose; to measure position of a stable stored beam. Because the pickup signals are multiplexed into a single receiver, and due to its narrow bandwidth, the receiver is not intended for single-turn studies. The receiver delivers normalized measurements of X and Y position entirely by analog means at nominally 1 V/mm. No computers are involved. No software is required. Bergoz, a French company specializing in precision beam instrumentation, integrated the ALS design m their new BPM analog signal processor module. Performance comparisons were made on the ALS. In this paper we report on the architecture and performance of the ALS prototype BPM

  8. Low power analog readout front-end electronics for time and energy measurements

    International Nuclear Information System (INIS)

    We report on the design and measurements of an analog front-end readout electronics dedicated for silicon microstrip detectors with relatively large capacitance of the order of tens pF for time and energy measurements of incoming pulses. The front-end readout electronics is required to process input pulses with an average rate of 150 kHz/channel with low both power consumption and noise at the same time. In the presented solution the single channel is built of two different parallel processing paths: fast and slow. The fast path includes the fast CR–RC shaper with the peaking time tp=40 ns and is optimized to determine the input charge arrival time. The slow path, which consists of the slow CR–(RC)2 shaper with the peaking time tp=80 ns, is dedicated for low noise accurate energy measurement. The analog front-end electronics was implemented in UMC 180 nm CMOS technology as a prototype ASIC AFE. The AFE chip contains 8 channels with the size of 58 ?m×1150 ?m each. It has low power dissipation Pdiss=3.1 mW per single channel. The article presents the details of the front-end architecture and the measurement results

  9. Low power analog readout front-end electronics for time and energy measurements

    Energy Technology Data Exchange (ETDEWEB)

    Kleczek, R., E-mail: rafal.kleczek@agh.edu.pl; Grybos, P.; Szczygiel, R.

    2014-06-01

    We report on the design and measurements of an analog front-end readout electronics dedicated for silicon microstrip detectors with relatively large capacitance of the order of tens pF for time and energy measurements of incoming pulses. The front-end readout electronics is required to process input pulses with an average rate of 150 kHz/channel with low both power consumption and noise at the same time. In the presented solution the single channel is built of two different parallel processing paths: fast and slow. The fast path includes the fast CR–RC shaper with the peaking time t{sub p}=40 ns and is optimized to determine the input charge arrival time. The slow path, which consists of the slow CR–(RC){sup 2} shaper with the peaking time t{sub p}=80 ns, is dedicated for low noise accurate energy measurement. The analog front-end electronics was implemented in UMC 180 nm CMOS technology as a prototype ASIC AFE. The AFE chip contains 8 channels with the size of 58 ?m×1150 ?m each. It has low power dissipation P{sub diss}=3.1 mW per single channel. The article presents the details of the front-end architecture and the measurement results.

  10. Precision analog signal processor for beam position measurements in electron storage rings

    International Nuclear Information System (INIS)

    Beam position monitors (BPM) in electron and positron storage rings have evolved from simple systems composed of beam pickups, coaxial cables, multiplexing relays, and a single receiver (usually a analyzer) into very complex and costly systems of multiple receivers and processors. The older may have taken minutes to measure the circulating beam closed orbit. Today instrumentation designers are required to provide high-speed measurements of the beam orbit, often at the ring revolution frequency. In addition the instruments must have very high accuracy and resolution. A BPM has been developed for the Advanced Light Source (ALS) in Berkeley which features high resolution and relatively low cost. The instrument has a single purpose; to measure position of a stable stored beam. Because the pickup signals are multiplexed into a single receiver, and due to its narrow bandwidth, the receiver is not intended for single-turn studies. The receiver delivers normalized measurements of X and Y posit ion entirely by analog means at nominally 1 V/mm. No computers are involved. No software is required. Bergoz, a French company specializing in precision beam instrumentation, integrated the ALS design m their new BPM analog signal processor module. Performance comparisons were made on the ALS. In this paper we report on the architecture and performance of the ALS prototype BPM

  11. Associations between insulin and glucose concentrations and anthropometric measures of fat mass in Australian adolescents

    Directory of Open Access Journals (Sweden)

    Denney-Wilson Elizabeth

    2010-08-01

    Full Text Available Abstract Background One of the most serious, yet common co-morbidities of obesity is insulin resistance, which if untreated may progress to type 2 diabetes. This paper describes the insulin and glucose concentration distributions, the prevalence of elevated insulin, the associations between insulin and body mass index (BMI, waist circumference, waist-to-height ratio (WHtR and fat mass index in a representative sample of Australian adolescents. Methods Cross-sectional population-based study of adolescent boys and girls (N = 496, mean age 15.3 years attending schools in metropolitan Sydney, Australia. Fasting venous blood collected and analysed for insulin and glucose concentrations. Height, weight, waist circumference measured, BMI and waist-to-height ratio calculated. Pubertal status self-reported. Results Glucose concentrations were normally distributed and were not associated with adiposity. Insulin concentrations were distributed logarithmically, were higher among girls than boys overall and within the same ranges of BMI and waist circumference, but were lower among girls than boys within the same ranges of fat mass adjusted for height. The prevalence of elevated insulin concentration (defined as > 100 pmol/L was 15.9% and 17.1% among boys and girls, respectively. Correlations between insulin concentration and BMI, waist circumference, WHtR and fat mass adjusted for height were 0.53, 0.49, 0.51 and 0.55, among boys, respectively, and 0.35, 0.40, 0.42 and 0.34, among girls, respectively. Conclusions Elevated insulin is highly correlated with adiposity in adolescents. BMI and WHtR are simple measures that can be used to identify young people who should be screened for insulin resistance and other co-morbidities.

  12. Measurement of proliferation and disappearance of rapid turnover cell populations in human studies using deuterium-labeled glucose.

    OpenAIRE

    Macallan, DC; Asquith, B; Zhang, Y.; Lara, C; Ghattas, H.; Defoiche, J; Beverley, PC

    2009-01-01

    Cell proliferation may be measured in vivo by quantifying DNA synthesis with isotopically labeled deoxyribonucleotide precursors. Deuterium-labeled glucose is one such precursor which, because it achieves high levels of enrichment for a short period, is well suited to the study of rapidly dividing cells, in contrast to the longer term labeling achieved with heavy water ((2)H(2)O). As deuterium is non-radioactive and glucose can be readily administered, this approach is suitable for clinical s...

  13. Regional cerebral glucose consumption measured by positron emission tomography in patients with Wilson's disease

    International Nuclear Information System (INIS)

    Using positron emission tomography (PET), the regional cerebral metabolic rate of glucose consumption (rCMRGlc) was measured in 14 patients with Wilson's disease (WD) and 23 normal subjects. In WD patients, cerebellar, striatal and - to a lesser extent - cortical and thalamic rCMRGlc were significantly decreased compared with controls. Striatal rCMRGlc was significantly reduced in those 4 patients who had recently started decoppering therapy as compared with striatal rCMRGlc measured in those 10 patients with longer duration of medication. Caudate rCMRGlc correlated significantly with various signs of extrapyramidal dysfunction. Cerebellar, thalamic and cortical rCMRGlc correlated significantly with the severity of pyramidal signs. These data indicate that the PET measurement of rCMRGlc may be a useful tool to evaluate cerebral involvement in WD and to monitor the response to treatment. (orig.)

  14. Harmonical oscillator and electro-mechanical analogy: an interdiscinary experiment to high precision mass variation measurements

    Scientific Electronic Library Online (English)

    Ailton M., Watanabe; Adriano dos, Santos; Paulo R., Bueno.

    Full Text Available De forma geral, os cursos de física clássica oferecidos nas universidades carecem de exemplos de aplicações nas áreas de química e biologia, o que por vezes desmotivam os alunos de graduação destas áreas a estudarem os conceitos físicos desenvolvidos em sala de aula. Neste texto, a analogia entre os [...] osciladores elétrico e mecânico é explorada visando possívies aplicações em química e biologia, mostrando-se de grande valia devido ao seu uso em técnicas de medição de variação de massa com alta precisão, tanto de forma direta como indireta. Estas técnicas são conhecidas como técnicas eletrogravimétricas e são de especial importância em aplicações que envolvem biossensores. Desta forma, o texto explora o estudo da analogia eletromecânica de forma interdisciplinar envolvendo as áreas de física, química e biologia. Baseado nessa analogia é proposto um experimento que permite a sua aplicação em diferentes níveis conceituais dessas disciplinas, tanto em abordagem básica como mais profunda. Abstract in english In general, the traditional Physics courses needs examples of the aplications of the Physics concepts in other areas such as Chemistry and Biology. This lacks tend to demotivate Chemistry and Biology students regarding to deal with Physical concepts developed in classroom. In this work, the analogy [...] among mechanic and electric oscillators is investigated to be applied in Chemistry and Biology areas, showing to be valuable due to its aplication in techniques that aims to measure mass variation with high precision. This measure could be made in a direct or indirect way. These techniques are known as electrogravimetric techniques and they are important in biosensor aplications. Thus, this paper explores the electromechanic analogy in an interdisciplinary way involving areas like Physics, Chemistry and Biology. Based on this analogy, it is proposed an experiment that can be applied in different ways, i.e. by an basic approach or more deeper, depending on the students specific formation, in other words, Physics, Chemistry or Biology.

  15. Detecting analogies unconsciously

    Directory of Open Access Journals (Sweden)

    Katharina Henke

    2014-01-01

    Full Text Available Analogies may arise from the conscious detection of similarities between a present and a past situation. In this functional magnetic resonance imaging study, we tested whether young volunteers would detect analogies unconsciously between a current supraliminal (visible and a past subliminal (invisible situation. The subliminal encoding of the past situation precludes awareness of analogy detection in the current situation. First, participants encoded subliminal pairs of unrelated words in either one or nine encoding trials. Later, they judged the semantic fit of supraliminally presented new words that either retained a previously encoded semantic relation (‘analog’ or not (‘broken analog’. Words in analogs versus broken analogs were judged closer semantically, which reflects unconscious analogy detection. Hippocampal activity associated with subliminal encoding correlated with the behavioral measure of unconscious analogy detection. Analogs versus broken analogs were processed with reduced prefrontal but enhanced medial temporal activity. We conclude that analogous episodes can be detected even unconsciously drawing on the episodic memory network.

  16. Are Tubes Containing Sodium Fluoride Still Needed for the Measurement of Blood Glucose in Hospital Laboratory Practice?

    Directory of Open Access Journals (Sweden)

    Amira Al-Kharusi

    2014-11-01

    Full Text Available Objectives: To compare glucose values obtained using sodium flouride (NaF tubes and serum separation tubes (SST in a tertiary care hospital laboratory setting.? Methods: This study was conducted at the Clinical Biochemistry Laboratory, Royal Hospital, Oman. During the study period (1 September–30 November 2013, 50 pairs (one NaF tube and one SST of patient’s blood specimens were randomly collected. Following separation of plasma (NaF tubes and serum (SST, glucose concentrations were measured by hexokinase assay using the Architect c8000. Fifteen pairs of these tubes were kept in the refrigerator at 4°C and plasma/serum glucose concentrations were measured daily up to seven days after collection.? Results: Comparing plasma (NaF and serum (SST results of glucose values (n=50 showed an average difference of 0.00mmol/L (range -0.60 to +0.60mmol/L. Bland Altman analysis gave a non-significant constant bias of 0.10 ±0.195mmol/L (bias ±SD. Pearson correlation between plasma (NaF and serum (SST glucose concentrations revealed a significant correlation approaching unity with r2= 0.9991. No significant differences in glucose values were noted for both plasma and serum in 15 pairs of NaF and SST tubes when analyzed seven days following refrigeration. Hemolysis was observed in five (10% NaF tubes compared with two (4% SST.? Conclusion: There is no difference in glucose values collected from plasma NaF tubes or serum SST, and so SST can be used in hospital laboratory settings as there are practical advantages, including cost-effectiveness and reduction in blood volume drawn when utilizing these tubes for glucose and other tests from a single blood collection tube.

  17. Are Tubes Containing Sodium Fluoride Still Needed for the Measurement of Blood Glucose in Hospital Laboratory Practice?

    Science.gov (United States)

    Al-Kharusi, Amira; Al-Lawati, Nuha; Al-Kindi, Manal; Mula-Abed, Waad-Allah

    2014-01-01

    Objectives To compare glucose values obtained using sodium flouride (NaF) tubes and serum separation tubes (SST) in a tertiary care hospital laboratory setting. Methods This study was conducted at the Clinical Biochemistry Laboratory, Royal Hospital, Oman. During the study period (1 September–30 November 2013), 50 pairs (one NaF tube and one SST) of patient’s blood specimens were randomly collected. Following separation of plasma (NaF tubes) and serum (SST), glucose concentrations were measured by hexokinase assay using the Architect c8000. Fifteen pairs of these tubes were kept in the refrigerator at 4°C and plasma/serum glucose concentrations were measured daily up to seven days after collection. Results Comparing plasma (NaF) and serum (SST) results of glucose values (n=50) showed an average difference of 0.00mmol/L (range -0.60 to +0.60mmol/L). Bland Altman analysis gave a non-significant constant bias of 0.10 ±0.195mmol/L (bias ±SD). Pearson correlation between plasma (NaF) and serum (SST) glucose concentrations revealed a significant correlation approaching unity with r2= 0.9991. No significant differences in glucose values were noted for both plasma and serum in 15 pairs of NaF and SST tubes when analyzed seven days following refrigeration. Hemolysis was observed in five (10%) NaF tubes compared with two (4%) SST. Conclusion There is no difference in glucose values collected from plasma NaF tubes or serum SST, and so SST can be used in hospital laboratory settings as there are practical advantages, including cost-effectiveness and reduction in blood volume drawn when utilizing these tubes for glucose and other tests from a single blood collection tube. PMID:25584156

  18. Bi-functionalization of a patterned Prussian blue array for amperometric measurement of glucose via two integrated detection schemes.

    Science.gov (United States)

    Zhang, Na; Wilkop, Thomas; Lee, Soohyun; Cheng, Quan

    2007-02-01

    A novel amperometric sensor that integrates two independent measurement schemes into a single chip for detection of glucose is fabricated. The sensor uses micro-patterned Prussian blue (PB) and ferrocene modified glucose oxidase covered by a thin Nafion membrane. We have developed an amperometric sensor for the detection of glucose that integrates two measurement schemes into a single chip. For fabrication of the sensing interface, micro-contact printing was used to transfer a self-assembled monolayer template onto a gold substrate, allowing selective electrochemical deposition of a PB array. The protective layer of the PB array was subsequently removed and replaced with a layer of redox-functionalized glucose oxidase (GOx), while the entire surface was finally covered with a perm-selective GOx-Nafion membrane. A variety of surface analytical techniques, including atomic force microscopy, surface plasmon resonance imaging and spectroscopic ellipsometry were employed to characterize the composite PB array electrode. The hybrid sensing interface allowed amperometric measurements of glucose to be carried out with two independent schemes at different potentials. The cathodic current was obtained with the PB array functioning as the electrocatalyst, while the anodic current was measured at a higher potential via a mediation mechanism using the ferrocene-modified GOx. For the quantitative detection of glucose, flow-injection analysis was used, and both the operating conditions and the design parameters were optimized. Linear responses were obtained for both anodic and cathodic signals over a concentration range from 0.1 to 50 mM, with a detection limit of 75 microM. The specificity of the sensor was demonstrated with respect to ascorbic and lactic acid. The implementation of integrated detection mechanisms allows the independent measurement of amperometric signals at two separate potentials. This improves the information gathering and opens up new avenues for developing novel methods that potentially eliminate false signal readings. PMID:17260077

  19. Working Memory and Dynamic Measures of Analogical Reasoning as Predictors of Children's Math and Reading Achievement

    Science.gov (United States)

    Stevenson, Claire E.; Bergwerff, Catharina E.; Heiser, Willem J.; Resing, Wilma C. M.

    2014-01-01

    Working memory and inductive reasoning ability each appear related to children's achievement in math and reading. Dynamic measures of reasoning, based on an assessment procedure including feedback, may provide additional predictive value. The aim of this study was to investigate whether working memory and dynamic measures of analogical

  20. IN SITU MEASUREMENTS OF THE SIZE AND DENSITY OF TITAN AEROSOL ANALOGS

    Energy Technology Data Exchange (ETDEWEB)

    Hoerst, S. M.; Tolbert, M. A, E-mail: sarah.horst@colorado.edu [Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO (United States)

    2013-06-10

    The organic haze produced from complex CH{sub 4}/N{sub 2} chemistry in the atmosphere of Titan plays an important role in processes that occur in the atmosphere and on its surface. The haze particles act as condensation nuclei and are therefore involved in Titan's methane hydrological cycle. They also may behave like sediment on Titan's surface and participate in both fluvial and aeolian processes. Models that seek to understand these processes require information about the physical properties of the particles including their size and density. Although measurements obtained by Cassini-Huygens have placed constraints on the size of the haze particles, their densities remain unknown. We have conducted a series of Titan atmosphere simulation experiments and measured the size, number density, and particle density of Titan aerosol analogs, or tholins, for CH{sub 4} concentrations from 0.01% to 10% using two different energy sources, spark discharge and UV. We find that the densities currently in use by many Titan models are higher than the measured densities of our tholins.

  1. In Situ Measurements of the Size and Density of Titan Aerosol Analogs

    Science.gov (United States)

    Horst, Sarah; Tolbert, M. A.

    2013-10-01

    The organic haze produced from complex CH4/N2 chemistry in the atmosphere of Titan plays an important role in processes that occur in the atmosphere and on its surface. The haze particles act as condensation nuclei and are therefore involved in Titan’s methane hydrological cycle. They also may behave like sediment on Titan’s surface and participate in both fluvial and aeolian processes. Models that seek to understand these processes require information about the physical properties of the particles including their size and density. Although measurements obtained by Cassini-Huygens have placed constraints on the size of the haze particles, their densities remain unknown.We have conducted a series of Titan atmosphere simulation experiments and measured the size, number density, and particle density of Titan aerosol analogs, or tholins, for CH4 concentrations from 0.01% to 10% using two different energy sources, spark discharge and UV. We find that the densities currently in use by many Titan models are higher than the measured densities of our tholins.

  2. High Precision Dielectric Permittivity Measurements of Planetary Regolith analogs Using A Split-Cylinder Resonator

    Science.gov (United States)

    Tsai, C. A.; Boivin, A.; Ghent, R. R.; Daly, M. G.; Bailey, R. C.

    2014-12-01

    Complex relative permittivity is essential for quantitative interpretation of radar data in remote sensing of planetary surfaces. The real part determines the speed of the electromagnetic waves, while the imaginary part is related to the penetration depth. This project is part of NASA's OSIRIS-REx asteroid sample return mission. Radar is an important tool for asteroid investigation, particularly for detecting and characterizing regolith; but without robust knowledge of dielectric properties, these data cannot be used to their greatest advantage. Here, we present preliminary measurements of complex relative permittivity using the split-cylinder resonator method at 10 GHz. Resonant cavity methods utilize the difference in resonant frequency between an empty cavity and a cavity containing a sample to calculate relative permittivity and loss tangent of the sample, at higher precision than is possible with other methods. We use these split-cylinder measurements of solid samples at a single frequency in conjunction with companion broadband (300 MHz to 14 GHz) measurements of powders. Our goal is to establish a "parameter space" that characterize the effects of various factors such as water content, frequency, and the relative abundances of mineralogical and elemental constituents such as iron and titanium on complex relative permittivity of geological materials that might represent good analogs for the regolith of Bennu, OSIRIS-REx's target asteroid. Our results will also provide a database for future asteroid exploration with radar.

  3. In vitro glucose measurement using tunable mid-infrared laser spectroscopy combined with fiber-optic sensor

    OpenAIRE

    Yu, SongLin; Li, Dachao; Chong, Hao; Sun, Changyue; Yu, Haixia; Xu, Kexin

    2013-01-01

    Because mid-infrared (mid-IR) spectroscopy is not a promising method to noninvasively measure glucose in vivo, a method for minimally invasive high-precision glucose determination in vivo by mid-IR laser spectroscopy combined with a tunable laser source and small fiber-optic attenuated total reflection (ATR) sensor is introduced. The potential of this method was evaluated in vitro. This research presents a mid-infrared tunable laser with a broad emission spectrum band of 9.19 to 9.77?m(1024~...

  4. Photoacoustic blood glucose and skin measurement based on optical scattering effect

    Science.gov (United States)

    Zhao, Zuomin; Myllyla, Risto A.

    2002-07-01

    Non-invasive blood glucose determination has been investigated by more than 100 research groups in the world during the past fifteen years. The commonly optical methods are based on the capacity of near-IR light to penetrate a few hundreds micrometers or a few millimeters into human tissue where it interacts with glucose. A change of glucose concentration may modify the optical parameters in tissue, with the result that its glucose concentration can be extracted by analyzing the received optical signals. This paper demonstrates that glucose affects on the scattering coefficient of human blood, by applying the streak camera and pulsed photoacoustic techniques; and drinking water seems also affecting on PA signal from skin surface.

  5. A Novel Analog Integrated Circuit Design Course Covering Design, Layout, and Resulting Chip Measurement

    Science.gov (United States)

    Lin, Wei-Liang; Cheng, Wang-Chuan; Wu, Chen-Hao; Wu, Hai-Ming; Wu, Chang-Yu; Ho, Kuan-Hsuan; Chan, Chueh-An

    2010-01-01

    This work describes a novel, first-year graduate-level analog integrated circuit (IC) design course. The course teaches students analog circuit design; an external manufacturer then produces their designs in three different silicon chips. The students, working in pairs, then test these chips to verify their success. All work is completed within…

  6. Analog earthquakes

    Energy Technology Data Exchange (ETDEWEB)

    Hofmann, R.B. [Center for Nuclear Waste Regulatory Analyses, San Antonio, TX (United States)

    1995-09-01

    Analogs are used to understand complex or poorly understood phenomena for which little data may be available at the actual repository site. Earthquakes are complex phenomena, and they can have a large number of effects on the natural system, as well as on engineered structures. Instrumental data close to the source of large earthquakes are rarely obtained. The rare events for which measurements are available may be used, with modfications, as analogs for potential large earthquakes at sites where no earthquake data are available. In the following, several examples of nuclear reactor and liquified natural gas facility siting are discussed. A potential use of analog earthquakes is proposed for a high-level nuclear waste (HLW) repository.

  7. Intracellular Glucose Concentration in Derepressed Yeast Cells Consuming Glucose Is High Enough To Reduce the Glucose Transport Rate by 50%

    OpenAIRE

    Teusink, Bas; Diderich, Jasper A.; Westerhoff, Hans V.; van Dam, Karel; Walsh, Michael C.

    1998-01-01

    In Saccharomyces cerevisiae cells exhibiting high-affinity glucose transport, the glucose consumption rate at extracellular concentrations above 10 mM was only half of the zero trans-influx rate. To determine if this regulation of glucose transport might be a consequence of intracellular free glucose we developed a new method to measure intracellular glucose concentrations in cells metabolizing glucose, which compares glucose stereoisomers to correct for adhering glucose. The intracellular gl...

  8. Effects of Zinc Supplementation on the Anthropometric Measurements, Lipid Profiles and Fasting Blood Glucose in the Healthy Obese Adults

    Directory of Open Access Journals (Sweden)

    Sepide Mahluji

    2013-02-01

    Full Text Available Purpose: The aim of this study was to assess the effects of zinc supplementation on anthropometric measures, improving lipid profile biomarkers, and fasting blood glucose level in obese people. Methods: This randomized, double- blind clinical trial was carried out on 60 obese participants in the 18-45 age range for one month. The participants were randomly divided into the intervention group, who received 30 mg/d zinc gluconate, and the placebo group who received 30mg/d starch. Anthropometric measurements (body mass index (BMI, weight and waist circumference were recorded before and at the end of study. Lipid profile biomarkers and fasting blood glucose were determined using enzymatic procedure. Analysis of Covariance (ANCOVA test was run to compare the post-treatment values of the two groups, and t-test was conducted to compare within group changes. Results: Serum zinc concentration was increased significantly in intervention group (p=0.024. BMI and body weight was significantly decreased (p=0.030 and p=0.020, respectively. Lipid profile biomarkers and fating blood glucose did not change significantly but triglyceride level was significantly decreased (p=0.006 in the intervention group. Conclusion: The obtained results indicate that zinc supplementation improves BMI, body weight, and triglyceride concentration without considerable effects on lipid profile and glucose level. Zinc can be suggested as a suitable supplementation therapy for obese people, but more studies are needed to verify the results.

  9. Measurement of glucose metabolism in patients with dilated cardiomyopathy using positron emission tomography with 18F-FDG: Initial Experience

    International Nuclear Information System (INIS)

    Introduction: Fluorine18 deoxyglucose (18F-FDG) has been used in numerous studies to determine the cardiac rate of glucose metabolism in normal and pathological conditions. It is known that during heart failure the metabolic pattern is altered. Patlack's graphical analysis allows the assessment of heart muscle glucose consumption in patients with non-ischaemic heart failure and normal subjects. Methods: Standardized measurement of glucose metabolism was performed in four patients with dilated cardiomyopathy and three healthy subjects. All subjects received an oral load of carbohydrates (75gr) previous to scanning. Dynamic images of the thorax were acquired. Myocardial uptake was estimated from time-activity curves in the atrium and left ventricle using Patlack's graphical analysis. Results: All subjects studied were male. 18F-FDG uptake rate for the group with dilated cardiomyopathy was 1.31±0.2, versus 1.26±0.37 ml/100gr/min in the control group. Conclusion: Measurement of cardiac glucose metabolism by 18F-FDG PET is feasible in a clinical service, allowing impact evaluation of physiologic and metabolic changes in the myocardium in different pathologic scenarios in addition to therapy assessment

  10. Measurement of regional cerebral glucose utilization in man by positron emission tomography

    International Nuclear Information System (INIS)

    The various methods available for the study of regional cerebral glucose consumption in man by positron emission tomography are described and their applications, limitations and principal physiopathological results are presented

  11. Correlation Between Analog Noise Measurements and the Expected Bit Error Rate of a Digital Signal Propagating Through Passive Components

    Science.gov (United States)

    Warner, Joseph D.; Theofylaktos, Onoufrios

    2012-01-01

    A method of determining the bit error rate (BER) of a digital circuit from the measurement of the analog S-parameters of the circuit has been developed. The method is based on the measurement of the noise and the standard deviation of the noise in the S-parameters. Once the standard deviation and the mean of the S-parameters are known, the BER of the circuit can be calculated using the normal Gaussian function.

  12. Self-monitoring of blood glucose measurements and glycaemic control in a managed care paediatric type 1 diabetes practice

    Scientific Electronic Library Online (English)

    B, Davey; D G, Segal.

    2015-05-01

    Full Text Available BACKGROUND: Intensive diabetes management requires intensive insulin treatment and self-monitoring of blood glucose (SMBG) measurements to obtain immediate information on the status of the blood glucose level and to obtain data for pattern analysis on which meal planning, insulin and lifestyle adjus [...] tments can be made. The value and optimal frequency of SMBGs are often questioned OBJECTIVES: To document the relationship between SMBG frequency and glycaemic control in a managed care paediatric type 1 diabetes practice METHODS: A retrospective analysis was performed on 141 managed care paediatric and adolescent patients over a 1-year period from 1 February 2010 to 30 January 2011. The patients were stratified according to their insulin regimen. The frequency of SMBG was analysed and glycaemic control measured by glycated haemoglobin (HbA1c RESULTS: A highly significant decrease (p

  13. Inhibition of JNK phosphorylation by a novel curcumin analog prevents high glucose-induced inflammation and apoptosis in cardiomyocytes and the development of diabetic cardiomyopathy.

    Science.gov (United States)

    Pan, Yong; Wang, Yi; Zhao, Yunjie; Peng, Kesong; Li, Weixin; Wang, Yonggang; Zhang, Jingjing; Zhou, Shanshan; Liu, Quan; Li, Xiaokun; Cai, Lu; Liang, Guang

    2014-10-01

    Hyperglycemia-induced inflammation and apoptosis have important roles in the pathogenesis of diabetic cardiomyopathy. We recently found that a novel curcumin derivative, C66, is able to reduce the high glucose (HG)-induced inflammatory response. This study was designed to investigate the protective effects on diabetic cardiomyopathy and its underlying mechanisms. Pretreatment with C66 significantly reduced HG-induced overexpression of inflammatory cytokines via inactivation of nuclear factor-?B in both H9c2 cells and neonatal cardiomyocytes. Furthermore, we showed that the inhibition of Jun NH2-terminal kinase (JNK) phosphorylation contributed to the protection of C66 from inflammation and cell apoptosis, which was validated by the use of SP600125 and dominant-negative JNK. The molecular docking and kinase activity assay confirmed direct binding of C66 to and inhibition of JNK. In mice with type 1 diabetes, the administration of C66 or SP600125 at 5 mg/kg significantly decreased the levels of plasma and cardiac tumor necrosis factor-?, accompanied by decreasing cardiac apoptosis, and, finally, improved histological abnormalities, fibrosis, and cardiac dysfunction without affecting hyperglycemia. Thus, this work demonstrated the therapeutic potential of the JNK-targeting compound C66 for the treatment of diabetic cardiomyopathy. Importantly, we indicated a critical role of JNK in diabetic heart injury, and suggested that JNK inhibition may be a feasible strategy for treating diabetic cardiomyopathy. PMID:24848068

  14. Experimental study for cancer diagnosis with positron-labeled fluorinated glucose analogs: [18F]-2-fluoro-2-deoxy-D-mannose

    International Nuclear Information System (INIS)

    18F-2-fluoro-2-deoxy-D-glucose (18F-FDG) and 18F-2-fluoro-2-deoxy-D-mannose (18F-FDM) were tested as tumor diagnostic agents in a transplantable rat tumor and rabbit tumors. Tissue distribution studies in rats showed high tumor uptakes of both radiopharmaceuticals. The tumor uptake reached 2.65+-0.61% dose 18F-FDG/g and 2.65+-0.81% dose 18F-FDM/g at 60 min and remained relatively constant until 120 min. Blood clearance of both 18F-FDG and 18F-FDM was very rapid and tumor-to-blood ratios reached 22.1 and 29.4 at 60 min, respectively. Tumor-to-tissue ratios of both radiopharmaceuticals were very high in most organs, especially in the liver, kidney, and pancreas. Positron emission tomography (PET) of rabbit tumor with 18F-FDM clearly delineated the main tumor, central necrosis, and lymph node metastases. These data suggested that 18F-FDM, which is a by-product of 18F-FDG synthesis, was also an excellent cancer diagnostic agent as well as 18-F-FDG. This is not only a new feature of 18F-FDM, but also an economical improvement on cancer diagnosis by PET. (orig.)

  15. Brain metabolism in autism. Resting cerebral glucose utilization rates as measured with positron emission tomography

    International Nuclear Information System (INIS)

    The cerebral metabolic rate for glucose was studied in ten men (mean age = 26 years) with well-documented histories of infantile autism and in 15 age-matched normal male controls using positron emission tomography and (F-18) 2-fluoro-2-deoxy-D-glucose. Positron emission tomography was completed during rest, with reduced visual and auditory stimulation. While the autistic group as a whole showed significantly elevated glucose utilization in widespread regions of the brain, there was considerable overlap between the two groups. No brain region showed a reduced metabolic rate in the autistic group. Significantly more autistic, as compared with control, subjects showed extreme relative metabolic rates (ratios of regional metabolic rates to whole brain rates and asymmetries) in one or more brain regions

  16. Brain metabolism in autism. Resting cerebral glucose utilization rates as measured with positron emission tomography

    Energy Technology Data Exchange (ETDEWEB)

    Rumsey, J.M.; Duara, R.; Grady, C.; Rapoport, J.L.; Margolin, R.A.; Rapoport, S.I.; Cutler, N.R.

    1985-05-01

    The cerebral metabolic rate for glucose was studied in ten men (mean age = 26 years) with well-documented histories of infantile autism and in 15 age-matched normal male controls using positron emission tomography and (F-18) 2-fluoro-2-deoxy-D-glucose. Positron emission tomography was completed during rest, with reduced visual and auditory stimulation. While the autistic group as a whole showed significantly elevated glucose utilization in widespread regions of the brain, there was considerable overlap between the two groups. No brain region showed a reduced metabolic rate in the autistic group. Significantly more autistic, as compared with control, subjects showed extreme relative metabolic rates (ratios of regional metabolic rates to whole brain rates and asymmetries) in one or more brain regions.

  17. Developmental expression of the glucose transporter in brain microvessels

    International Nuclear Information System (INIS)

    Brain microvessels were isolated from late gestation fetal (55-68 days), newborn (5-9 day old) and adult guinea pigs. Glucose transport was assessed by measuring the initial uptake of [3H]-2-deoxy-D-glucose, a glucose analog that is transported and phosphorylated but not further metabolized. At 22C and substrate concentrations of 40 mM, uptakes were linear for 8 minutes. The data reported here were uptakes over the first 2 minutes. 2-deoxy-D-glucose uptake was 3.5 fold higher in newborn microvessels, 99.5±18.4 (SEM) fmols/mg protein/2 minutes, compared to fetal, 27.8±7.9. The number of glucose transporters was estimated using the [3H] cytochalasin B which can be displaced by D-glucose (250 mM). Binding at 35 nM cytochalasin B was higher in newborn brain microvessels (8.2±1.6 pmole/mg protein) than in fetal (3.4±1.1) or adult (2.8±0.6) brain microvessels. Initial RNA blot experiments using a cDNA for the brain/erythrocyte (HepG2) glucose transporter show increased expression in newborn microvessels compared to the fetus or the adult. The authors conclude that the brain microvessel glucose transporter is increased in the newborn period

  18. Preliminary Broadband Measurements of Dielectric Permittivity of Planetary Regolith Analog Materials Using a Coaxial Airline

    Science.gov (United States)

    Boivin, A.; Tsai, C. A.; Ghent, R. R.; Daly, M. G.

    2014-12-01

    When considering radar observations of airless bodies containing regolith, the radar backscatter coefficient is dependent upon the complex dielectric permittivity of the regolith materials. In many current applications of imaging radar data, uncertainty in the dielectric permittivity precludes quantitative estimates of such important parameters as regolith thickness and depth to buried features (e.g., lava flows on the Aristarchus Plateau on the Moon and the flows that surround the Quetzalpetlatl Corona on Venus). For asteroids, radar is an important tool for detecting and characterizing regoliths. Many previous measurements of the real and/or complex parts of the dielectric permittivity have been made, particularly for the Moon (on both Apollo samples and regolith analogues). However, no studies to date have systematically explored the relationship between permittivity and the various mineralogical components such as presence of FeO and TiO2. For lunar materials, the presence of the mineral ilmenite (FeTiO3), which contains equal portions FeO and TiO2, is thought to be the dominant factor controlling the loss tangent (tan?, the ratio of the imaginary and real components of the dielectric permittivity). Ilmenite, however, is not the only mineral to contain iron in the lunar soil and our understanding of the effect of iron on the loss tangent is insufficient. Beyond the Moon, little is known about the effects on permittivity of carbonaceous materials. This is particularly relevant for missions to asteroids, such as the OSIRIS-REx mission to (101955) Bennu, a carbonaceous asteroid whose regolith composition is largely unknown. Here we present preliminary broadband (300 Mhz to 14 GHz) measurements on materials intended as planetary regolith analogs. Our ultimate goal is to establish a database of the effects of a wide range mineralogical components on dielectric permittivity, in support of the OSIRIS REx mission and ongoing Earth-based radar investigation of the Moon. In addition to facilitating quantitative interpretation of lunar radar data, our results will provide context into which samples returned by OSIRIS REx will fit, and will therefore inform future remote exploration of asteroids.

  19. Development of a passive air sampler to measure airborne organophosphorus pesticides and oxygen analogs in an agricultural community.

    Science.gov (United States)

    Armstrong, Jenna L; Yost, Michael G; Fenske, Richard A

    2014-09-01

    Organophosphorus pesticides are some of the most widely used insecticides in the US, and spray drift may result in human exposures. We investigate sampling methodologies using the polyurethane foam passive air sampling device to measure cumulative monthly airborne concentrations of OP pesticides chlorpyrifos, azinphos-methyl, and oxygen analogs. Passive sampling rates (m(3)d(-1)) were determined using calculations using chemical properties, loss of depuration compounds, and calibration with side-by-side active air sampling in a dynamic laboratory exposure chamber and in the field. The effects of temperature, relative humidity, and wind velocity on outdoor sampling rates were examined at 23 sites in Yakima Valley, Washington. Indoor sampling rates were significantly lower than outdoors. Outdoor rates significantly increased with average wind velocity, with high rates (>4m(3)d(-1)) observed above 8ms(-1). In exposure chamber studies, very little oxygen analog was observed on the PUF-PAS, yet substantial amounts chlorpyrifos-oxon and azinphos methyl oxon were measured in outdoor samples. PUF-PAS is a practical and useful alternative to AAS because it results in little artificial transformation to the oxygen analog during sampling, it provides cumulative exposure estimates, and the measured sampling rates were comparable to rates for other SVOCs. It is ideal for community based participatory research due to low subject burden and simple deployment in remote areas. PMID:24997910

  20. Estimation of utility values from visual analog scale measures of health in patients undergoing cardiac surgery

    Directory of Open Access Journals (Sweden)

    Oddershede L

    2014-01-01

    Full Text Available Lars Oddershede,1,2 Jan Jesper Andreasen,1 Lars Ehlers2 1Department of Cardiothoracic Surgery, Center for Cardiovascular Research, Aalborg University Hospital, Aalborg, Denmark; 2Danish Center for Healthcare Improvements, Faculty of Social Sciences and Faculty of Health Sciences, Aalborg University, Aalborg East, Denmark Introduction: In health economic evaluations, mapping can be used to estimate utility values from other health outcomes in order to calculate quality adjusted life-years. Currently, no methods exist to map visual analog scale (VAS scores to utility values. This study aimed to develop and propose a statistical algorithm for mapping five dimensions of health, measured on VASs, to utility scores in patients suffering from cardiovascular disease. Methods: Patients undergoing coronary artery bypass grafting at Aalborg University Hospital in Denmark were asked to score their health using the five VAS items (mobility, self-care, ability to perform usual activities, pain, and presence of anxiety or depression and the EuroQol 5 Dimensions questionnaire. Regression analysis was used to estimate four mapping models from patients' age, sex, and the self-reported VAS scores. Prediction errors were compared between mapping models and on subsets of the observed utility scores. Agreement between predicted and observed values was assessed using Bland–Altman plots. Results: Random effects generalized least squares (GLS regression yielded the best results when quadratic terms of VAS scores were included. Mapping models fitted using the Tobit model and censored least absolute deviation regression did not appear superior to GLS regression. The mapping models were able to explain approximately 63%–65% of the variation in the observed utility scores. The mean absolute error of predictions increased as the observed utility values decreased. Conclusion: We concluded that it was possible to predict utility scores from VAS scores of the five dimensions of health used in the EuroQol questionnaires. However, the use of the mapping model may be inappropriate in more severe conditions. Keywords: coronary artery bypass grafts, mapping, cross-walk, quality of life, outcomes research

  1. Continuous and simultaneous electrochemical measurements of glucose, lactate, and ascorbate in rat brain following brain ischemia.

    Science.gov (United States)

    Lin, Yuqing; Yu, Ping; Hao, Jie; Wang, Yuexiang; Ohsaka, Takeo; Mao, Lanqun

    2014-04-15

    Developing new tools and technologies to enable recording the dynamic changes of multiple neurochemicals is the essence of better understanding of the molecular basis of brain functions. This study demonstrates a microfluidic chip-based online electrochemical system (OECS) for in vivo continuous and simultaneous monitoring of glucose, lactate, and ascorbate in rat brain. To fabricate the microfluidic chip-based detecting system, a microfluidic chip with patterned channel is developed into an electrochemical flow cell by incorporating the chip with three surface-modified indium-tin oxide (ITO) electrodes as working electrodes, a Ag/AgCl wire as reference electrode, and a stainless steel tube as counter electrode. Selective detection of ascorbate is achieved by the use of single-walled carbon nanotubes (SWNTs) to largely facilitate the electrochemical oxidation of ascorbate, while a dehydrogenase-based biosensing mechanism with methylene green (MG) adsorbed onto SWNTs as an electrocatalyst for the oxidation of dihydronicotiamide adenine dinucleotide (NADH) is employed for biosensing of glucose and lactate. To avoid the crosstalk among three sensors, the sensor alignment is carefully designed with the SWNT-modified electrode in the upstream channel and paralleled glucose and lactate biosensors in the downstream channels. With the microfluidic chip-based electrochemical flow cell as the detector, an OECS is successfully established by directly integrating the microfluidic chip-based electrochemical flow cell with in vivo microdialysis. The OECS exhibits a good linear response toward glucose, lactate, and ascorbate with less crosstalk. This property, along with the high stability and selectivity, enables the OECS for continuously monitoring three species in rat brain following brain ischemia. PMID:24621127

  2. Nucleic Acid Base Analog FRET-Pair Facilitating Detailed Structural Measurements in Nucleic Acid Containing Systems

    DEFF Research Database (Denmark)

    Börjesson, Karl; Preus, SØren

    2009-01-01

    We present the first nucleobase analog fluorescence resonance energy transfer (FRET)-pair. The pair consists of tCO, 1,3-diaza-2-oxophenoxazine, as an energy donor and the newly developed tC(nitro), 7-nitro-1,3-diaza-2-oxophenothiazine, as an energy acceptor. The FRET-pair successfully monitors distances covering up to more than one turn of the DNA duplex. Importantly, we show that the rigid stacking of the two base analogs, and consequently excellent control of their exact positions and orientations, results in a high control of the orientation factor and hence very distinct FRET changes as the number of bases separating tCO and tC(nitro) is varied. A set of DNA strands containing the FRET-pair at wisely chosen locations will, thus, make it possible to accurately distinguish distance- from orientation-changes using FRET. In combination with the good nucleobase analog properties, this points toward detailed studies of the inherent dynamics of nucleic acid structures. Moreover, the placement of FRET-pair chromophores inside the base stack will be a great advantage in studies where other (biomacro)molecules interact with the nucleic acid. Lastly, our study gives possibly the first truly solid experimental support to the dependence of energy transfer efficiency on orientation of involved transition dipoles as predicted by the Forster theory.

  3. Glucose Sensing

    CERN Document Server

    Geddes, Chris D

    2006-01-01

    Topics in Fluorescence Spectroscopy, Glucose Sensing is the eleventh volume in the popular series Topics in Fluorescence Spectroscopy, edited by Drs. Chris D. Geddes and Joseph R. Lakowicz. This volume incorporates authoritative analytical fluorescence-based glucose sensing reviews specialized enough to be attractive to professional researchers, yet also appealing to the wider audience of scientists in related disciplines of fluorescence. Glucose Sensing is an essential reference for any lab working in the analytical fluorescence glucose sensing field. All academics, bench scientists, and industry professionals wishing to take advantage of the latest and greatest in the continuously emerging field of glucose sensing, and diabetes care & management, will find this volume an invaluable resource. Topics in Fluorescence Spectroscopy Volume 11, Glucose Sensing Chapters include: Implantable Sensors for Interstitial Fluid Smart Tattoo Glucose Sensors Optical Enzyme-based Glucose Biosensors Plasmonic Glucose Sens...

  4. Comparative measurement of regional blood flow, oxygen and glucose utilisation in soft tissue tumour of rabbit with positron imaging

    International Nuclear Information System (INIS)

    C15O2 and 15O2 steady state techniques were used to measure regional blood flow (RBF) and regional oxygen utilisation (ROU) in a rabbit tumour model. RBF values were 4.6+-0.6 ml min/100 cc for normal muscle tissue and 11.0+-3.0 ml/min/100 cc for tumour surface. Corresponding values for ROU were 18.3+-3.5 ?mol/min/100 cc for normal tissue and 39.7+-20.1 ?mol/min/100 cc for tumour surface. 18F-2-fluoro-2-deoxy-D-glucose (2FDG) was used in the same model to measure glucose metabolic rate. The values obtained were 4.3+-2.1 ?mol/min/100 cc for normal muscle and 53.8+-18.3 ?mol/min/100 cc for tumour tissue. Tumour-to-muscle ratios increased more rapidly with time for 2FDG than for oxygen utilisation and blood flow. The effect of radiation on tumour and normal tissue was followed by measurements of RBF and ROU. RBF values increased both in tumour and normal muscle tissue during radiation and decreased during one week after radiation. ROU-values decreased (30%) in tumour and increased (45%) in normal muscle tissue during radiation. One week after radiation, ROU-values were 30% lower in tumour and 45% higher in normal muscle tissue. (U.K.)

  5. Non-steady Force Measurement in an Orpheous Gas Turbine Engine Using Hydraulic Analogy

    Directory of Open Access Journals (Sweden)

    J. S. Rao

    1985-10-01

    Full Text Available Determination of non-steady forces in a real turbine stage is difficult due to local flow conditions e.g. high pressure, high temperature and inaccessibility to the region etc. Experimentation in a real turbine is also prohibitive due to the costs involved. Recently, an alternative method of arriving at these non-steady forces through use of hydraulic analogy has been tried on flat plates. The paper describes the simulation of an orpheous gas turbine engine stage on the rotating water table. It discusses the modelling aspects and presents a comparison of the experimental and theoretical results obtained.

  6. Glucose Tests

    Science.gov (United States)

    ... Insulin overdose Tumors that produce insulin ( insulinomas) Starvation Deliberate use of glucose-lowering products Urine Glucose Low ... online through http://www.merck.com . ADA Clinical Practice Recommendations. Diabetes Care 28:S37-S42, 2005. Available ...

  7. GLUCOSE ELECTROOXIDATION

    OpenAIRE

    Pasta, Mauro

    2010-01-01

    The electrooxidation of glucose has attracted a lot of interest due to its applications in blood glucose sensors and biological fuel cells. Glucose sensors optimization is highly necessary to improve the treatment of Diabetes Mellitus, a chronic disease affecting millions of people around the world, while biological fuel cells have been studied in order to explore new, renewable energy sources alternative to fossil fuels. There are three main ways to perform glucose electrooxidation, depen...

  8. A MEMS Dielectric Affinity Glucose Biosensor

    OpenAIRE

    Xian HUANG; Li, Siqi; Davis, Erin; Li, Dachao; Wang, Qian; Qiao LIN

    2013-01-01

    Continuous glucose monitoring (CGM) sensors based on affinity detection are desirable for long-term and stable glucose management. However, most affinity sensors contain mechanical moving structures and complex design in sensor actuation and signal readout, limiting their reliability in subcutaneously implantable glucose detection. We have previously demonstrated a proof-of-concept dielectric glucose sensor that measured pre-mixed glucose-sensitive polymer solutions at various glucose concent...

  9. Associations between Ultrasound Measures of Abdominal Fat Distribution and Indices of Glucose Metabolism in a Population at High Risk of Type 2 Diabetes: The ADDITION-PRO Study

    DEFF Research Database (Denmark)

    Philipsen, Annelotte; JØrgensen, Marit E

    2015-01-01

    AIMS: Visceral adipose tissue measured by CT or MRI is strongly associated with an adverse metabolic risk profile. We assessed whether similar associations can be found with ultrasonography, by quantifying the strength of the relationship between different measures of obesity and indices of glucose metabolism in a population at high risk of type 2 diabetes. METHODS: A cross-sectional analysis of 1342 participants of the ADDITION-PRO study. We measured visceral adipose tissue and subcutaneous adipose tissue with ultrasonography, anthropometrics and body fat percentage by bioelectrical impedance. Indices of glucose metabolism were derived from a three point oral glucose tolerance test. Linear regression of obesity measures on indices of glucose metabolism was performed. RESULTS: Mean age was 66.2 years, BMI 26.9kg/m2, subcutaneous adipose tissue 2.5cm and visceral adipose tissue 8.0cm. All measures of obesity were positively associated with indicators of glycaemia and inversely associated with indicators of insulin sensitivity. Associations were of equivalent magnitude except for subcutaneous adipose tissue and the visceral/subcutaneous adipose tissue ratio, which showed weaker associations. One standard deviation difference in BMI, visceral adipose tissue, waist circumference, waist/height ratio and body fat percentage corresponded approximately to 0.2mmol/l higher fasting glucose, 0.7mmol/l higher 2-hr glucose, 0.06-0.1% higher HbA1c, 30 % lower HOMA index of insulin sensitivity, 20% lower Gutt's index of insulin sensitivity, and 100 unit higher Stumvoll's index of beta-cell function. After adjustment for waist circumference visceral adipose tissue was still significantly associated with glucose intolerance and insulin resistance, whereas there was a trend towards inverse or no associations with subcutaneous adipose tissue. After adjustment, a 1cm increase in visceral adipose tissue was associated with ~5% lower insulin sensitivity (p?0.0004) and ~0.18mmol/l higher 2-hr glucose (p?0.001). CONCLUSION: Visceral and subcutaneous adipose tissue assessed by ultrasonography are significantly associated with glucose metabolism, even after adjustment for other measures of obesity.

  10. Associations between Ultrasound Measures of Abdominal Fat Distribution and Indices of Glucose Metabolism in a Population at High Risk of Type 2 Diabetes: The ADDITION-PRO Study

    Science.gov (United States)

    Philipsen, Annelotte; Jørgensen, Marit E.; Vistisen, Dorte; Sandbaek, Annelli; Almdal, Thomas P.; Christiansen, Jens S.; Lauritzen, Torsten; Witte, Daniel R.

    2015-01-01

    Aims Visceral adipose tissue measured by CT or MRI is strongly associated with an adverse metabolic risk profile. We assessed whether similar associations can be found with ultrasonography, by quantifying the strength of the relationship between different measures of obesity and indices of glucose metabolism in a population at high risk of type 2 diabetes. Methods A cross-sectional analysis of 1342 participants of the ADDITION-PRO study. We measured visceral adipose tissue and subcutaneous adipose tissue with ultrasonography, anthropometrics and body fat percentage by bioelectrical impedance. Indices of glucose metabolism were derived from a three point oral glucose tolerance test. Linear regression of obesity measures on indices of glucose metabolism was performed. Results Mean age was 66.2 years, BMI 26.9kg/m2, subcutaneous adipose tissue 2.5cm and visceral adipose tissue 8.0cm. All measures of obesity were positively associated with indicators of glycaemia and inversely associated with indicators of insulin sensitivity. Associations were of equivalent magnitude except for subcutaneous adipose tissue and the visceral/subcutaneous adipose tissue ratio, which showed weaker associations. One standard deviation difference in BMI, visceral adipose tissue, waist circumference, waist/height ratio and body fat percentage corresponded approximately to 0.2mmol/l higher fasting glucose, 0.7mmol/l higher 2-hr glucose, 0.06-0.1% higher HbA1c, 30 % lower HOMA index of insulin sensitivity, 20% lower Gutt’s index of insulin sensitivity, and 100 unit higher Stumvoll’s index of beta-cell function. After adjustment for waist circumference visceral adipose tissue was still significantly associated with glucose intolerance and insulin resistance, whereas there was a trend towards inverse or no associations with subcutaneous adipose tissue. After adjustment, a 1cm increase in visceral adipose tissue was associated with ~5% lower insulin sensitivity (p?0.0004) and ~0.18mmol/l higher 2-hr glucose (p?0.001). Conclusion Visceral and subcutaneous adipose tissue assessed by ultrasonography are significantly associated with glucose metabolism, even after adjustment for other measures of obesity. PMID:25849815

  11. Measurement of cerebral oxidative glucose consumption in patients with type 1 diabetes and hypoglycemia unawareness using 13C nuclear magnetic resonance spectroscopy

    Science.gov (United States)

    Henry, Pierre-Gilles; Criego, Amy B.; Kumar, Anjali; Seaquist, Elizabeth R.

    2009-01-01

    The aim of the present study was to use 13C NMR to measure the cerebral oxidative metabolic rate of glucose (CMRglc(ox)) in patients with diabetes and to compare these measurements with those collected from matched controls. We elected to study a group with type 1 diabetes and hypoglycemia unawareness, since we had previously found such patients to have higher brain glucose concentrations than normal volunteers under steady state conditions. We sought to determine if this difference in steady-state brain concentrations could be explained by a difference in CMRglc(ox). Time courses of 13C label incorporation in brain amino acids were measured in occipital cortex during infusion of [1-13C]glucose. These time courses were fitted using a one-compartment metabolic model to determine CMRglc(ox). Our results show that the TCA cycle rate (VTCA, which is twice CMRglc(ox)) in subjects with type 1 diabetes was not significantly different from normal controls (0.84 ± 0.03 vs 0.79 ± 0.03 ?mol/gm/min, n=5 in each group, mean ± SEM). We conclude that the changes in steady-state brain glucose concentrations that we observed in patients with type 1 diabetes in a previous study (1) cannot be explained by changes in oxidative glucose consumption PMID:19766263

  12. Measurement of local glucose transport rate constant and free glucose pool in human brain using PET and CMG: First result in normals and Huntington patients

    International Nuclear Information System (INIS)

    Even in images reconstructed with the method of filtered backprojection it is possible to perform parametric images on a pixel by pixel base with use of appropriate stable algorithms. There is no doubt, that these analytical procedures are less efficient than the iterative ones, but they are doing well when relative values between pixels are of interest. The approach using a Lookup-Table was determined to be best and used in normals and Huntington patients. The first results show that in Huntington patients the transport of glucose is not regional affected, but globally reduced. Following studies on a large patient pool will challenge and proceed further this presented technique. (orig.)

  13. The influence of image resolution on the positron emission tomographic measurement of caudate glucose consumption

    International Nuclear Information System (INIS)

    The aim of this study was to investigate the influence of image resolution on (a) relative and absolute values of caudate glucose consumption (rCMRGlc) determined by positron emission tomography (PET), and (b) the detection of significant differences in these metabolic values between groups of subjects. For this purpose, raw data of cerebral accumulation of fluorine-18 fluorodeoxyglucose (FDG) obtained in 11 normal subjects and in nine patients with unilateral thalamic infarction were reconstructed using filtered backprojection with four different cut-off frequencies (CFs), yielding images with a transaxial resolution of 5.7, 7.1, 8.9 and 11 mm (full-width at half-maximum; FWHM). Absolute values of candate rCMRGls decreased significantly by more than 30% over the range of image resolutions studied. Bilateral ratios of caudate rCMRGls were insensitive to variations in image resolution. Levels if significance assessing the differences in mean metabolic values between patients and controls were all below 0.01. They were, however, slightly better at image resolutions of 7,1 and 8.9 mm than at a resolution of 5.7 mm. These data indicate (a) that relative values of rCMRGls are better suited to compare quantitative results from different PET cameras than are absolute values, and (b) that th CF used for the filtered backprojection exerts a small but not negligible influence on levels of significance assessing differences in metabolic values between groups of subjects. (orig.)values between groups of subjects. (orig.)

  14. Serum leptin levels in acromegalic patients before and during somatostatin analogs therapy.

    Science.gov (United States)

    Baldelli, R; Durante, C; D'Amico, E; Diacono, F; Tamburrano, G; Casanueva, F F

    2003-12-01

    GH excess is characterized by alterations of body composition such as decreased body fat mass; however, scant data are present regarding its effect on serum leptin levels. To better elucidate this topic, leptin secretion was studied in 20 acromegalic patients, before and after 6 months of treatment with somatostatin analogs (SR-lanreotide 30 mg and octreotide LAR). Basal GH, IGF-I, insulin, blood glucose and lipid levels were measured and the area under the curve (AUC) for insulin and glucose and oral glucose insulin sensitivity (OGIS) during oral glucose tolerance test (OGTT) were calculated. After 6 months of somatostatin analogs therapy, a significant reduction in GH and IGF-I plasma levels was observed (p<0.0005, both) with a significant increase of leptin levels (7.4+/-1.3 vs 13.2+/-1.6 ng/ml; p<0.05). Interestingly, the typical correlation of leptin with body mass index (BMI) was not present in active acromegaly, whereas it was restored after somatostatin analogs treatment; moreover, the gender difference in leptin secretion between men and women was preserved in active and controlled acromegaly. In conclusion, the gender-based leptin differences are preserved and leptin secretion/BMI ratio is normalized in acromegalic patients after somatostatin analogs therapy. PMID:15055476

  15. Analog computing

    CERN Document Server

    Ulmann, Bernd

    2013-01-01

    This book is a comprehensive introduction to analog computing. As most textbooks about this powerful computing paradigm date back to the 1960s and 1970s, it fills a void and forges a bridge from the early days of analog computing to future applications. The idea of analog computing is not new. In fact, this computing paradigm is nearly forgotten, although it offers a path to both high-speed and low-power computing, which are in even more demand now than they were back in the heyday of electronic analog computers.

  16. Utility and validity of a single-item visual analog scale for measuring dental anxiety in clinical practice.

    Science.gov (United States)

    Appukuttan, Devapriya; Vinayagavel, Mythreyi; Tadepalli, Anupama

    2014-01-01

    We evaluated whether a visual analog scale (VAS) was comparable to the multi-item Modified Dental Anxiety Scale (MDAS) in assessing dental anxiety in clinical practice. In total, 200 consecutive patients aged 20-70 years who presented at the dental outpatient department of SRM Dental College, Chennai were enrolled. The test-retest value for the VAS was 0.968. The Spearman rank correlations between the VAS and MDAS items and total score were significant (P MDAS accounted for 74% of the variation. The regression coefficient was statistically significant (P MDAS and the VAS in identifying patients with and without dental anxiety at cut-offs of 13 and 4.75, respectively. The VAS was found to be a valid measure and was comparable to the multi-item MDAS. PMID:24930752

  17. Electric Field Measurements in Terrestrial Dust Devils and Dust Storms, as an Analog to Mars

    Science.gov (United States)

    Estrin, C. R.; Elliott, H. M.; Szocik, M. A.; Kim, S.; Renno, N. O.; Williams, E. R.; Nathou, N.; Pathare, A.; Metzger, S.; Balme, M.

    2011-12-01

    Dust devils and dust storms are important contributors to the atmospheric dust content on Earth and Mars. The electric fields resulting from a dust charging mechanism [Renno and Kok, 2008] are thought to play an important role in the lofting and suspension of these dust particles. To understand this mechanism, a new type of isolated electric field sensor has been designed and fabricated to make accurate measurements of the electric field when subjected to the impact of charged dust particles. Here we present the results of these measurements and discuss their implications for atmospheric chemistry, in particular their significance to Mars, where dust plays a key role.

  18. Measurement of regional cerebral metabolic rate for glucose in the human subject with (F-18)-2-deoxy-2-fluoro-d-glucose and emission computed tomography: validation of the method

    International Nuclear Information System (INIS)

    Tracer techniques and models of in vitro quantitative autoradiography and tissue counting for the measure of regional metabolic rates (rMR) are combined with emission computed tomography (ECT). This approach, Physiologic Tomography (PT), provides atraumatic and analytical measurements of rMR. PT is exemplified with the regional measurement of the cerebral metabolic rate for glucose (CMRGlu) in man with (18F)-2-deoxy-2-fluoro-D-glucose (FDG) and positron ECT. Our model incorporates a k4* mediated hydrolysis of FDG-6-PO4 to FDG which then competes with phosphorylation (k3*) of FDG back to FDG-6-PO4 and reverse transport (k2*) back to blood. Although small, k4* is found to be significant. The ECAT positron tomograph was used to measure the rate constants (k1*?k4*), lumped constant (LC), stability, and reproducibility of the model in man. Since these parameters have not been measured for FDG in any species, comparisons are made to values for DG in rat and monkey. Compartmental concentrations of FDG and FDG-6-PO4 were determined and show that cerebral FDG-6-PO4 steadily accumulates for about 100 mins, plateaus and then slowly decreases due to hydrolysis. Cerebral blood FDG concentration was determined to be a minor contribution to tissue activity after 10 min. Regional CMRGlu measurements are reproducible to +- 5.5% over 5 hrs. PT allows the in vivo study ofregional biochemistry and physiology in normal and pathophysiologic states in man with a unique and fundamental capability

  19. Laser spectroscopic real time measurements of methanogenic activity under simulated Martian subsurface analog conditions

    Science.gov (United States)

    Schirmack, Janosch; Böhm, Michael; Brauer, Chris; Löhmannsröben, Hans-Gerd; de Vera, Jean-Pierre; Möhlmann, Diedrich; Wagner, Dirk

    2014-08-01

    On Earth, chemolithoautothrophic and anaerobic microorganisms such as methanogenic archaea are regarded as model organisms for possible subsurface life on Mars. For this reason, the methanogenic strain Methanosarcina soligelidi (formerly called Methanosarcina spec. SMA-21), isolated from permafrost-affected soil in northeast Siberia, has been tested under Martian thermo-physical conditions. In previous studies under simulated Martian conditions, high survival rates of these microorganisms were observed. In our study we present a method to measure methane production as a first attempt to study metabolic activity of methanogenic archaea during simulated conditions approaching conditions of Mars-like environments. To determine methanogenic activity, a measurement technique which is capable to measure the produced methane concentration with high precision and with high temporal resolution is needed. Although there are several methods to detect methane, only a few fulfill all the needed requirements to work within simulated extraterrestrial environments. We have chosen laser spectroscopy, which is a non-destructive technique that measures the methane concentration without sample taking and also can be run continuously. In our simulation, we detected methane production at temperatures down to -5 °C, which would be found on Mars either temporarily in the shallow subsurface or continually in the deep subsurface. The pressure of 50 kPa which we used in our experiments, corresponds to the expected pressure in the Martian near subsurface. Our new device proved to be fully functional and the results indicate that the possible existence of methanogenic archaea in Martian subsurface habitats cannot be ruled out.

  20. Measurement of Faraday rotation in twisted optical fiber using rotating polarization and analog phase detection

    International Nuclear Information System (INIS)

    We demonstrated phase modulation of rotating linearly polarized light by current-induced Faraday rotation in a single mode optical fiber and used the technique to measure the current in ZT-40M, a Reversed-Field Pinch. We have also demonstrated the practicality of using twisted sensing fiber to overcome the problems associated with linear birefringence

  1. Recent Advances in Continuous Glucose Monitoring: Biocompatibility of Glucose Sensors for Implantation in Subcutis

    OpenAIRE

    Kvist, Peter H; Jensen, Henrik E.

    2007-01-01

    Tight glycemic control slows or prevents the development of short- and long-term complications of diabetes mellitus. Continuous glucose measurements provide improved glycemic control and potentially prevent these diabetic complications. Glucose sensors, especially implantable devices, offer an alternative to classical self-monitored blood glucose levels and have shown promising glucose-sensing properties. However, the ultimate goal of implementing the glucose sensor as the glucose-sensing par...

  2. High glucose concentrations partially release hexokinase from inhibition by glucose 6-phosphate.

    OpenAIRE

    Fujii, S.; Beutler, E.

    1985-01-01

    The phosphorylation of glucose by human erythrocyte hexokinase follows classical Michaelis-Menten kinetics; hexokinase manifests maximum activity at 5 mM glucose, and no further increase in activity can be measured at higher glucose concentrations. However, the erythrocytes of diabetics and normal erythrocytes incubated with high concentrations of glucose contain increased concentrations of glucose 6-phosphate. To elucidate the mechanism of accumulation of glucose 6-phosphate when erythrocyte...

  3. An Implantable RFID Sensor Tag toward Continuous Glucose Monitoring.

    Science.gov (United States)

    Xiao, Zhibin; Tan, Xi; Chen, Xianliang; Chen, Sizheng; Zhang, Zijian; Zhang, Hualei; Wang, Junyu; Huang, Yue; Zhang, Peng; Zheng, Lirong; Min, Hao

    2015-05-01

    This paper presents a wirelessly powered implantable electrochemical sensor tag for continuous blood glucose monitoring. The system is remotely powered by a 13.56-MHz inductive link and utilizes an ISO 15693 radio frequency identification (RFID) standard for communication. This paper provides reliable and accurate measurement for changing glucose level. The sensor tag employs a long-term glucose sensor, a winding ferrite antenna, an RFID front-end, a potentiostat, a 10-bit sigma-delta analog to digital converter, an on-chip temperature sensor, and a digital baseband for protocol processing and control. A high-frequency external reader is used to power, command, and configure the sensor tag. The only off-chip support circuitry required is a tuned antenna and a glucose microsensor. The integrated chip fabricated in SMIC 0.13-?m CMOS process occupies an area of 1.2 mm ×2 mm and consumes 50 ?W. The power sensitivity of the whole system is -4 dBm. The sensor tag achieves a measured glucose range of 0-30 mM with a sensitivity of 0.75 nA/mM. PMID:25823049

  4. Analog multivariate counting analyzers

    CERN Document Server

    Nikitin, A V; Armstrong, T P

    2003-01-01

    Characterizing rates of occurrence of various features of a signal is of great importance in numerous types of physical measurements. Such signal features can be defined as certain discrete coincidence events, e.g. crossings of a signal with a given threshold, or occurrence of extrema of a certain amplitude. We describe measuring rates of such events by means of analog multivariate counting analyzers. Given a continuous scalar or multicomponent (vector) input signal, an analog counting analyzer outputs a continuous signal with the instantaneous magnitude equal to the rate of occurrence of certain coincidence events. The analog nature of the proposed analyzers allows us to reformulate many problems of the traditional counting measurements, and cast them in a form which is readily addressed by methods of differential calculus rather than by algebraic or logical means of digital signal processing. Analog counting analyzers can be easily implemented in discrete or integrated electronic circuits, do not suffer fro...

  5. Glucose allostasis

    DEFF Research Database (Denmark)

    Stumvoll, Michael; Tataranni, P Antonio

    2003-01-01

    In many organisms, normoglycemia is achieved by a tight coupling of nutrient-stimulated insulin secretion in the pancreatic beta-cell (acute insulin response [AIR]) and the metabolic action of insulin to stimulate glucose disposal (insulin action [M]). It is widely accepted that in healthy individuals with normal glucose tolerance, normoglycemia can always be maintained by compensatorily increasing AIR in response to decreasing M (and vice versa). This has been mathematically described by the hyperbolic relationship between AIR and M and referred to as glucose homeostasis, with glucose concentration assumed to remain constant along the hyperbola. Conceivably, glucose is one of the signals stimulating AIR in response to decreasing M. Hypothetically, as with any normally functioning feed-forward system, AIR should not fully compensate for worsening M, since this would remove the stimulus for the compensation. We provide evidence from cross-sectional, longitudinal, and prospective data from Pima Indians (n = 413) and Caucasians (n = 60) that fasting and postprandial glucose concentrations increase with decreasing M despite normal compensation of AIR. For this physiologic adaptation to chronic stress (insulin resistance), we propose to use the term "glucose allostasis." Allostasis (stability through change) ensures the continued homeostatic response (stability through staying the same) to acute stress at some cumulative costs to the system. With increasing severity and over time, the allostatic load (increase in glycemia) may have pathological consequences, such as the development of type 2 diabetes.

  6. Regulation of glucose metabolism in oral streptococci through independent pathways of glucose 6-phosphate and glucose 1-phosphate formation.

    OpenAIRE

    Keevil, C. W.; Marsh, P. D.; Ellwood, D. C.

    1984-01-01

    In vivo rates of glucose uptake and acid production by oral streptococci grown in glucose- or nitrogen-limited continuous culture and batch culture were compared with the glucose phosphorylation activities of harvested, decryptified cells. The strains examined contained significant phosphoenolpyruvate-phosphotransferase system (PTS) activity, measured by a glucose 6-phosphate (G6P) dehydrogenase-linked assay procedure, but this activity was insufficient to account for the in vivo glucose upta...

  7. Foregut exclusion disrupts intestinal glucose sensing and alters portal nutrient and hormonal milieu.

    Science.gov (United States)

    Pal, Atanu; Rhoads, David B; Tavakkoli, Ali

    2015-06-01

    The antidiabetes effects of Roux-en-Y gastric bypass (RYGB) are well-known, but the underlying mechanisms remain unclear. Isolating the proximal small intestine, and in particular its luminal glucose sensors, from the nutrient stream has been proposed as a critical change, but the pathways involved are unclear. In a rodent model, we tested the effects of isolating and then stimulating a segment of proximal intestine using glucose analogs to examine their impact on glucose absorption (Gabsorp) and hormone secretion after a glucose bolus into the distal jejunum. Analogs selective for sodium-glucose cotransporter (SGLT) family members and the sweet taste receptor were tested, and measurements of the portosystemic gradient were used to determine Gabsorp and hormone secretion, including GLP-1. Proximal intestinal isolation reduced Gabsorp and GLP-1 secretion. Stimulation of the glucose-sensing protein SGLT3 increased Gabsorp and GLP-1 secretion. These effects were abolished by vagotomy. Sweet taste receptor stimulation only increased GLP-1 secretion. This study suggests a novel role for SGLT3 in coordinating intestinal function, as reflected by the concomitant modulation of Gabsorp and GLP-1 secretion, with these effects being mediated by the vagus nerve. Our findings provide potential mechanistic insights into foregut exclusion in RYGB and identify SGLT3 as a possible antidiabetes therapeutic target. PMID:25576062

  8. Troubleshooting analog circuits

    CERN Document Server

    Pease, Robert A

    1991-01-01

    Troubleshooting Analog Circuits is a guidebook for solving product or process related problems in analog circuits. The book also provides advice in selecting equipment, preventing problems, and general tips. The coverage of the book includes the philosophy of troubleshooting; the modes of failure of various components; and preventive measures. The text also deals with the active components of analog circuits, including diodes and rectifiers, optically coupled devices, solar cells, and batteries. The book will be of great use to both students and practitioners of electronics engineering. Other

  9. On-line measurements of oscillating mitochondrial membrane potential in glucose-fermenting Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Andersen, Ann Zahle; Poulsen, Allan K

    2007-01-01

    We employed the fluorescent cyanine dye DiOC(2)(3) to measure membrane potential in semi-anaerobic yeast cells under conditions where glycolysis was oscillating. Oscillations in glycolysis were studied by means of the naturally abundant nicotinamide adenine dinucleotide (NADH). We found that the mitochondrial membrane potential was oscillating, and that these oscillations displayed the same frequency and duration as the NADH oscillations. It was confirmed that DiOC(2)(3) localizes itself in the mitochondrial membrane and thus reports qualitative changes solely in mitochondrial membrane potential. Our studies showed that glycolytic oscillations perturb the mitochondrial membrane potential and that the mitochondria do not have any controlling effect on the dynamics of glycolysis under these conditions. Depolarization of the mitochondrial membrane by addition of FCCP quenched mitochondrial membrane potential oscillations and delocalized DiOC(2)(3), while glycolysis continued to oscillate unaffected.

  10. A Low Frequency Electromagnetic Sensor for Indirect Measurement of Glucose Concentration: In Vitro Experiments in Different Conductive Solutions

    Directory of Open Access Journals (Sweden)

    Andrea Tura

    2010-05-01

    Full Text Available In recent years there has been considerable interest in the study of glucose-induced dielectric property variations of human tissues as a possible approach for non-invasive glycaemia monitoring. We have developed an electromagnetic sensor, and we tested in vitro its ability to estimate variations in glucose concentration of different solutions with similarities to blood (sodium chloride and Ringer-lactate solutions, differing though in the lack of any cellular components. The sensor was able to detect the effect of glucose variations over a wide range of concentrations (~78–5,000 mg/dL, with a sensitivity of ~0.22 mV/(mg/dL. Our proposed system may thus be useful in a new approach for non-invasive and non-contact glucose monitoring.

  11. Glucose Dependency of the Metabolic Pathway of HEK 293 Cells Measured by a Flow-through Type pH/CO2 Sensor System Using ISFETs

    Science.gov (United States)

    Yamada, Akira; Mohri, Satoshi; Nakamura, Michihiro; Naruse, Keiji

    Our group previously reported the application of a flow-through type pH/CO2 sensor system designed to evaluate the metabolic activity of cultured cells. The sensor system consists of two ion-sensitive field effect transistors (ISFETs), an ISFET to measure the total pH change and an ISFET enclosed within a gas-permeable silicone tube to measure the pH change attributable to CO2. In that study, we used the system to quantitatively analyze metabolic switching induced by glucose concentration changes in three cultured cell types (bovine arterial endothelium cell (BAEC), human umbilical vein endothelium cell (HUVEC), and rat cardiomuscle cell (RCMC)), and to measure the production rates of total carbonate and free lactic acid in the cultured cells. In every cell type examined, a decrease in the glucose concentration led to an increase in total carbonate, a product of cellular respiration, and a decrease of free lactic acid, a product of glycolysis. There were very significant differences among the cell types, however, in the glucose concentrations at the metabolic switching points. We postulated that the cell has a unique switching point on the metabolic pathway from glycolysis to respiration. In this paper we use our sensor system to evaluate the metabolic switching of human embryonic kidney 293 cells triggered by glucose concentration changes. The superior metabolic pathway switched from glycolysis to respiration when the glucose concentration decreased to about 2 mM. This result was very similar to that obtained in our earlier experiments on HUVECs, but far different from our results on the other two cells types, BAECs and RCMCs. This sensor system will be useful for analyzing cellular metabolism for many applications and will yield novel information on different cell types.

  12. Estimating Plasma Glucose from Interstitial Glucose: The Issue of Calibration Algorithms in Commercial Continuous Glucose Monitoring Devices

    OpenAIRE

    Paolo Rossetti; Josep Vehí; Jorge Bondia; Fanelli, Carmine G.

    2010-01-01

    Evaluation of metabolic control of diabetic people has been classically performed measuring glucose concentrations in blood samples. Due to the potential improvement it offers in diabetes care, continuous glucose monitoring (CGM) in the subcutaneous tissue is gaining popularity among both patients and physicians. However, devices for CGM measure glucose concentration in compartments other than blood, usually the interstitial space. This means that CGM need calibration against blood glucose va...

  13. Measurement of muscle and whole body (WB) glucose metabolism (GM) in vivo by combined stable isotope (SI) and PET techniques - Validation in an animal model

    International Nuclear Information System (INIS)

    Aim/Background: Primed-constant infusion of SI labeled tracers is a classic technique for studying metabolism at the WB level, however, without invasive A-V difference data it provides no information about the metabolism of specific tissues. In contrast PET provides primarily tissue specific data. The aim of this study is to apply PET in combination with SI methods in an animal to simultaneously quantify substrate metabolism in specific tissues and the WB. Methods and materials: Animals: Seven white New Zealand rabbits (Mean ± SE 3.7 ± 0.1 kg;) were studied. After 14 hours of fast, they were surgically prepared by tracheotomy and implantation of catheters into carotid artery (Ca), jugular vein (Jv), and right femoral vein (Fv) under anesthesia. PET Imaging: The animal was placed in supine position in the gantry of a PC-4096 PET camera. Transmission images (5 min.) with a rotating pin source containing fib 68Ge were acquired with the central tomographic slice positioned to include both hind limbs (HLs). Each animal received C15O2 inhalation and was imaged for blood flow (BE) rate in HL muscles. Then, 18FDG (? 8 mCi) was injected into the animal through jugular vein, followed by serial PET images of muscle glucose metabolism (GM) for 90 min. Primed constant infusion of [6,6, 2H]-glucose (0.8?mol/kg/min, priming 64umol/kg) was conducted simultaneously. Plateau level blood samples were taken from the Cl blood samples were taken from the Ca and Fv for WB and HL GM. Stable Isotope Measurements: The whole body glucose metabolic rate and the plasma glucose kinetics are calculated according to the conventional stable isotope steady state kinetics model. Q=i(E,/EP-l) where i is the infusion rate of stable isotope labeled [6,6, 2H2]-glucose, E1 and EP are the isotopic enrichments of [6,6, 2H2]-glucose in infusate and plasma under steady state conditions. The hind limb glucose metabolism was also measured using stable isotope tracer and tracee difference across the hind limb. WB GM determined by SI was 2.54 ± 0.22 mg/kg/min and GM in the right HL measured by A-V difference of ST was 0.77 ± 0.12 mg/leg/min. Based on muscle mass in HL (199 ± 7.8 g), LM GM (?g/g tissue/min) was calculated to be 3.40 ± 0.46 by St and 3.64 ± 0.22 by PET (N.S; paired t-test). BF to HL muscle determined by C15O2 inhalation was 0.059 ± 0.01 ml/g tissue/min. Discussion: The two in vivo methods provided comparable quantitative information on muscle protein metabolism. PET measurements have the advantage of less invasive than A-V difference methods using SI, but it does not provide the information on whole body glucose disposal rate. Therefore combined SI and PET would provide more complete picture of whole body and regional glucose metabolism in vivo. Conclusions: PET-ST is a non-invasive approach to simultaneously quantify WB and muscle GM without biopsy, hence a powerful tool for human studies under various physio-pathophysiological conditions. (author)

  14. Glucose urine test

    Science.gov (United States)

    ... condition in which glucose is released from the kidneys into the urine, even when blood glucose level is normal. ... condition in which glucose is released from the kidneys into the ... glucose levels are normal (renal glycosuria) Pregnancy -- Up to ...

  15. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... In this section Living With Diabetes Treatment and Care Blood Glucose Testing Checking Your Blood Glucose A1C and eAG Hypoglycemia (Low blood glucose) Hyperglycemia (High blood glucose) Dawn ...

  16. Employment of Item Response Theory to measure change in Children's Analogical Thinking Modifiability Test / Emprego da Teoria de Resposta do Item para medida de mudança no Children's Analogical Thinking Modifiability Test

    Scientific Electronic Library Online (English)

    Odoisa Antunes de, Queiroz; Ricardo, Primi; Lucas de Francisco, Carvalho; Sônia Regina Fiorim, Enumo.

    2013-12-01

    Full Text Available Provas assistidas, com fase intermediária de ensino, medem mudanças entre pré-teste e pós-teste pressupondo uma métrica comum entre eles. Para testar este pressuposto, aplicou-se a Teoria de Resposta ao Item nas respostas de 69 crianças à prova cognitiva assistida Children's Analogical Thinking Modi [...] fiability Test adaptada, com 12 itens, totalizando 828 respostas, para verificar se a escala original produzia os mesmos resultados em termos de quantificação de mudança que a escala equalizada obtida via Teoria de Resposta ao Item. Seguiram-se os passos: 1) ancoragem dos itens de pré e pós-teste, por uma análise cognitiva, encontrando-se três itens em comum; 2) estimação do parâmetro de dificuldade dos itens e comparação destes; 3) equalização dos itens e estimação dos "thetas"; 4) comparação das escalas. A métrica do Children's Analogical Thinking Modifiability Test foi semelhante à estimada pela Teoria de Resposta ao Item, mas é preciso diferenciar a dificuldade dos itens de pré e pós-teste, adequando-o a amostras com alto e baixo desempenho. Abstract in english Dynamic testing, with an intermediate phase of assistance, measures changes between pretest and post-test assuming a common metric between them. To test this assumption we applied the Item Response Theory in the responses of 69 children to dynamic cognitive testing Children's Analogical Thinking Mod [...] ifiability Test adapted, with 12 items, totaling 828 responses, with the purpose of verifying if the original scale yields the same results as the equalized scale obtained by Item Response Theory in terms of "changes quantifying". We followed the steps: 1) anchorage of the pre and post-test items through a cognitive analysis, finding 3 common items; 2) estimation of the items' difficulty level parameter and comparison of those; 3) equalization of the items and estimation of "thetas"; 4) comparison of the scales. The Children's Analogical Thinking Modifiability Test metric was similar to that estimated by the TRI, but it is necessary to differentiate the pre and post-test items' difficulty, adjusting it to samples with high and low performance.

  17. Mitochondrial membrane potential measurement of H9c2 cells grown in high-glucose and galactose-containing media does not provide additional predictivity towards mitochondrial assessment.

    Science.gov (United States)

    Rana, Payal; Nadanaciva, Sashi; Will, Yvonne

    2011-03-01

    Drug-induced mitochondrial toxicity is a contributing factor to many organ toxicities. The fact that some, but not all members of a particular drug class can induce mitochondrial dysfunction has necessitated the need for predictive screens within the drug development process. One of these screens is a cell viability assay done in two types of media, one containing high-glucose, the other, galactose. Since galactose-grown cells are more susceptible to mitochondrial toxicants than high-glucose-grown cells, this assay distinguishes compounds that cause toxicity primarily through mitochondrial targets from those that cause multifactorial toxicity. However, the assay does not show if compounds that cause multifactorial toxicity cause impairment on mitochondria. To address this problem, we investigated if multiplexing the assay with mitochondrial membrane potential measurements using the fluorescent dye, JC-1, could provide further information. We tested 28 drugs in the multiplexed assay and found that, although mitochondrial toxicants could be detected, no additional information was revealed about compounds that caused multifactorial toxicity. Hence, measurements with JC-1 did not provide additional information beyond what was detected using the cell viability assay. We conclude that even though the multiplexed assay is useful for HTS applications, it provides no additional value over the high-glucose-galactose cell viability assay. PMID:21126567

  18. Addressing glucose sensitivity measured by F-18 FDG PET in lung cancers for radiation treatment planning and monitoring

    International Nuclear Information System (INIS)

    Purpose: To address glucose sensitivity in lung cancers before and after radiation treatment (Tx). Methods and Materials: Twelve patients were each studied with two pre-Tx positron emission tomography (PET) scans and 3 patients each with one post-Tx PET scan, with glucose concentration [Glc] and maximum standard uptake value (SUV) recorded. The pre-Tx glucose sensitivity, g from SUV1/SUV2 = {[Glc]1/[Glc]2}g and Tx index, ? from SUVpost-Tx/SUVpre-Tx = {[Glc]post-Tx/[Glc]pre-Tx}? was calculated by linear regression. Pre-Tx SUVs were corrected to post-Tx Glc with g (SUV'pre-Tx) for a pure Tx effect, R ln(SUVpost-Tx/SUV'pre-Tx). Results: There were no significant differences in SUV but [Glc] were different (96.4 ± 10.9 vs. 88.3 ± 10.5, p = 0.015) between two pre-Tx PET scans. Linear regression yielded g -0.79 and ? = -1.78 to -2.41 (p < 0.0005 in all). The %?SUV after Tx for 3 patients without vs. with g correction were different by -12%, 0%, and + 7%, suggesting varying effects from glucose. R values were also different and mean R (-0.81 ± 0.38) was significantly different from zero (p = 0.03), consistent with successful Tx as confirmed by clinico-radiologic follow-up. Conclusions: The extra dimension of glucose sensitivity, g besides SUV incorporated in the combined Tx-derived ? may be a useful global Tx evaluation index useful global Tx evaluation index even with differing [Glc

  19. Noninvasive glucose sensing.

    Science.gov (United States)

    Arnold, Mark A; Small, Gary W

    2005-09-01

    The ability to measure glucose noninvasively in human subjects is a major objective for many research groups. Success will revolutionize the treatment of diabetes by providing a means to improve glycemic control, thereby delaying the onset of the medical complications associated with this disease. This article focuses on the current state of the art and attempts to identify the principal areas of research necessary to advance the field. Two fundamentally different approaches are identified for the development of noninvasive glucose sensing technology. The indirect approach attempts to measure glucose on the basis of its effect on a secondary process. The direct approach is based on the unique chemical structure of the glucose molecule. Advances for each approach are limited by issues of selectivity. Several critical parameters are discussed for the direct approach, including issues related to the optical path length, wavelength range, dimensionality of the multivariate calibration model, net analyte signal, spectral variance, and assessment of the chemical basis of measurement selectivity. A set of publication standards is recommended as a means to enhance progress toward a successful noninvasive monitor. PMID:16131049

  20. In vivo measurements of whole body (WB) and skeletal muscle glucose metabolism under basal and euglycemic insulin clamp (Clamp) by combined PET and stable isotope (SI) tracer studies

    International Nuclear Information System (INIS)

    Aim/Background: Primed-constant infusion of SI labeled tracers is a classic technique for studying metabolism at the WB level, however, this procedure provides no information about the metabolism of specific tissues. In contrast PET provides primarily tissue specific data. In this study, we combined PET with SI techniques to measure glucose metabolism in WB and lower limb skeletal muscle (LLM) of humans under Basal and Clamp conditions. Methods and Materials: Four healthy volunteers (73.0 ± 6.0 kg, mean ± sem) were studied. After fasting overnight, each subject was injected with 10 mCi of 18FDG and serial 1.0 min. PET images of the mid-thigh region were acquired over 90 min. Arterial blood samples were collected in parallel. Glucose metabolic rate (GM) was calculated with a 3-compartment / 4 rate constant model; LC assumed to be 1.0. A primed constant infusion of [6,6, 2H2]glucose was performed in parallel with the PET measurements. On another day, the PET and SI measurements were repeated under clamp conditions. All results are expressed as mean ± sem. Results: The glucose kinetics in whole body and in low limb skeletal muscles are shown. Under in vivo conditions, Clamp caused: 1) a 10.2 ± 2.3 fold increase in GM by LLM but only a 4.7 ± 0.4 fold increase in GM by MB. 2) Increased contribution of LLM to WB GM, indicating that LLM GM is more sensitive to insulin compared with anterior LLM (extensors). Discussion: The study demonstrsors). Discussion: The study demonstrated the unique advantages of using PET to study substrate metabolism in specific tissues in human subjects: i) It is less invasive than the conventional A-V difference and muscle biopsy method. ii) It provides a more detailed picture of substrate metabolism in different parts of the muscle in the same limb, as compared to one spot muscle biopsy. Data in demonstrated that GM in posterior LLM is more sensitive to insulin than that in anterior LLM. iii) It can detect substrate metabolism in deep muscles which cannot be reached by biopsy technique. Therefore PET combined with stable isotope tracer can non-invasively provide a more complete in vivo picture of glucose metabolism in WB and in different parts of the skeletal muscles in human subjects. Conclusions: 1. Euglycemic insulin clamp (EGIC) caused a significant suppress of endogenous glucose production, either released from glycogenolysis or gluconeogenesis in the fasting condition. 2. Glucose metabolism in LLM is more sensitively regulated by insulin than other tissues. 3. On the same lower limb, glucose metabolism posterior muscle group is more sensitively regulated by insulin than those in the anterior. (author)

  1. A Tale of Two Compartments: Interstitial Versus Blood Glucose Monitoring

    OpenAIRE

    Cengiz, Eda; Tamborlane, William V

    2009-01-01

    Self-monitoring of blood glucose was described as one of the most important advancements in diabetes management since the invention of insulin in 1920. Recent advances in glucose sensor technology for measuring interstitial glucose concentrations have challenged the dominance of glucose meters in diabetes management, while raising questions about the relationships between interstitial and blood glucose levels. This article will review the differences between interstitial and blood glucose and...

  2. Continuous glucose monitoring with glucose sensors: calibration and assessment criteria.

    Science.gov (United States)

    Lodwig, Volker; Heinemann, Lutz

    2003-01-01

    Continuous glucose monitoring (CM) by means of minimally invasive or noninvasive glucose sensors can help to further optimize metabolic control in patients with diabetes without need for frequent capillary blood glucose measurements. Most glucose sensors measure glucose concentration in the interstitial fluid (ISF). Because of the varying conditions in this compartment, a general in vitro calibration ( = factory calibration) by the manufacturer appears not to be possible. Therefore, calibration of the sensor signal must be performed by the patient himself repeatedly. The calibration procedure can be performed by means of conventional capillary blood glucose measurements in order to transform the sensor signals obtained from the specific compartment (e.g., ISF) into "blood" glucose values. A number of aspects can influence the validity of this procedure. The relationship between changes in blood glucose and in ISF glucose, in both time and concentration dimensions, is not well understood, especially during dynamic changes. The physical lag time, which critically depends on the glucose sensor technology used, can also introduce a systematic calibration error. After the first calibration, usually performed some hours after the application of a given glucose sensor, recalibration at certain intervals is necessary. Therefore, patients should critically assess the values displayed by a CM system. In the case of implausible glucose values they should verify the results by means of a conventional capillary glucose measurement. Up to now there is no consensus on assessment criteria to be used for evaluation of CM system performance and calibration quality. Existing methods of displaying CM values against corresponding reference values, including linear regression analysis and error grid analysis, as well as numeric criteria such as System Error, Predicted Error Sum of Squares (in %), and Mean Absolute Deviation are not generally applicable to CM. It appears as if they do not allow sufficient description of data obtained with CM systems. There is a pressing need to develop novel adequate assessment criteria enabling a better characterization of CM system performance. If these were used uniformly by all manufacturers and scientists assessing CM systems, this would allow a fair comparison of the performance of different systems. PMID:14511412

  3. Water and glucose gradients in the substrate measured with NMR imaging during solid-state fermentation with Aspergillus oryzae

    OpenAIRE

    Nagel, F.J.; As, H (Henk) van; Tramper, J.; Rinzema, A

    2002-01-01

    Gradients inside substrate particles cannot be prevented in solid-state fermentation. These gradients can have a strong effect on the physiology of the microorganisms but have hitherto received little attention in experimental studies. We report gradients in moisture and glucose content during cultivation of Aspergillus oryzae on membrane-covered wheat-dough slices that were calculated from 1H-NMR images. We found that moisture gradients in the solid substrate remain small when evaporation is...

  4. Comparison of polyurethane foam and XAD-2 sampling matrices to measure airborne organophosphorus pesticides and their oxygen analogs in an agricultural community

    Science.gov (United States)

    Armstrong, Jenna L.; Fenske, Richard A.; Yost, Michael G.; Tchong-French, Maria; Yu, Jianbo

    2013-01-01

    Side-by-side active air sampling for the organophosphorus (OP) pesticide, chlorpyrifos (CPF) and its oxygen analog, chlorpyrifos-oxon (CPF-O) was conducted with two recommended air sampling matrices: OSHA Versatile Sampling (OVS) tubes with XAD-2 resin, polyurethane foam (PUF) tubes, and passive PUF deposition disks. The study compared the proportion of artificially transformed CPF-O in the laboratory and in the field during a tree fruit application in Washington State. Lab results demonstrated that the NIOSH-recommended OVS tubes artificially transformed up to 32% of CPF to CPF-O during the sampling process, whereas PUF tubes had little to no artificial transformation (? 0.1%). In the field, the proportion of CPF-O in the sample was significantly higher on OVS tubes than on PUF tubes (p < 0.001), confirming that OVS tubes were converting a significant portion of CPF to CPF-O. In addition, PUF tubes reported measurable levels CPF-O in the field even when no artificial transformation was expected. We conclude that the PUF matrix is the superior sampling medium for OP oxygen analogs when compared to XAD-2 resin. Community-located PUF tube samples 24 hours post-application had considerably higher levels CPF-O (16–21 ng/m3) than near field samples during application (2–14 ng/m3), suggesting that the oxygen analog is volatile and formed during atmospheric transport. It is recommended that worker and community risk assessments begin to take into consideration the presence of the more toxic oxygen analogs when measuring for OP pesticide mixtures. PMID:23466277

  5. Glucose and fructose 6-phosphate cycle in humans

    International Nuclear Information System (INIS)

    We have determined the rate of glucose cycling by comparing turnovers of [2-3H]- and [6-3H]glucose under basal conditions and during a glucose infusion. Moreover, the activity of the fructose 6-phosphate cycle was assessed by comparing [3-3H]- and [6-3H]glucose. The study included eight lean subjects with normal glucose tolerance. They participated in two randomly performed investigations. In one experiment [2-3H]- and [6-3H]glucose were given simultaneously, while in the other only [3-3H]glucose was given. The basal rate of glucose cycling was 0.32 +/- 0.08 mg X kg-1 X min-1 or 17% of basal glucose production (P less than 0.005). During glucose infusion the activity of endogenous glucose cycling did not change but since glucose production was suppressed it amounted to 130% of glucose production. The basal fructose 6-phosphate cycle could be detected only in three subjects and was suppressed during glucose infusion. In conclusion, the glucose cycle is active in healthy humans both in basal conditions and during moderate hyperglycemia. In some subjects, the fructose 6-phosphate cycle also appears to be active. Thus it is preferable to use [6-3H]glucose rather than [3-3H]glucose when measuring glucose production and particularly when assessing glucose cycle

  6. POF based glucose sensor incorporating grating wavelength filters

    DEFF Research Database (Denmark)

    Hassan, Hafeez Ul; Aasmul, SØren

    2014-01-01

    Medtronic has already developed a plastic fiber based optical sensor to detect the concentration of glucose both in vivo and in-vitro. The glucose sensor is based on a competitive glucose binding affinity assay consisting of a glucose receptor and glucose analog (ligand) contained in a compartment made up of permeable membrane for exchanging of only small molecules such as glucose, salts etc. (Fig 1). The binding between the glucose binding protein labeled with flourophore and glucose like molecules labelled with dye, is reversible. In the presence of glucose, the glucose analog competes with the glucose on binding to the protein. The system reaches an equilibrium, which correlates with the glucose concentration.The assay chemistry makes donor and acceptor pair for FRET (Förster Resonance Energy Transfer). FRET results in decrease in donor emission intensity. Higher the concentration of glucose, more donor acceptor pairs got separated resulting in high intensity and vice versa. This change in optical signal is correlated to glucose concentration. (Fig.1) Medtronic Diabetes and DTU FOTONIK has been working together under the consortium of Marie Curie Research Framework called TRAINING AND RESEARCH IN POLYMER OPTICAL DEVICES; TRIPOD. Within the domain of TRIPOD, research is conducted on "Plastic Optical Fiber based Glucose Sensors Incorporating Grating Wavelength Filters". Research will be focused to optimized fiber tips for better coupling efficiency, reducing the response time of sensor, improve the mechanical stabilization of assay compartment by exploring the side excitation and side coupling method, ease of manufacturing and feasibility of Polymer Fiber Bragg gratings as filters. During the project, fibers will be drawn and fiber bragg gratings will be inscribed at DTU Fotonik and they will be characterized for glucose sensor at Medtronic Diabetes.

  7. Effects of 5 Thio-D-Glucose on cellular adenosine triphosphate levels and deoxyribonucleic acid rejoining in hypoxic and aerobic Chinese hamster cells

    International Nuclear Information System (INIS)

    Intracellular adenosine triphosphate (ATP) levels were measured in both hypoxic and aerobic cultures of V79 Chinese hamster cells treated with 5-thio-D-glucose (5-SH-D-Glc). This glucose analog, a known inhibitor of D-glucose transport and metabolism, reduced ATP in cell cultures allowed to become hypoxic by cell metabolism, but not in aerobic cultures treated similarly. Cells depleted of ATP were unable to rejoin x-ray induced deoxyribonucleic acid (DNA) strand breaks as measured by the alkaline sucrose gradient sedimentation technique. The inference for radiation therapy is that inhibition of glucose metabolism selectively depletes energy reserves in hypoxic cells, rendering these cells more radiosensitive and leading to a more effective tumor treatment

  8. A MEMS Dielectric Affinity Glucose Biosensor.

    Science.gov (United States)

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

    2013-06-20

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

  9. Fructose, Glucose and Hunger

    Medline Plus

    Full Text Available ... Videos & Tools You Are Here: Home ? Latest Health News ? Fructose, Glucose and Hunger URL of this page: http://www.nlm.nih.gov/medlineplus/videos/news/Fructose_Glucose_051615.html Fructose, Glucose and Hunger ...

  10. Fructose, Glucose and Hunger

    Science.gov (United States)

    ... medlineplus/videos/news/Fructose_Glucose_051615.html Fructose, Glucose and Hunger HealthDay News Video - May 6, 2015 ... this page, please enable JavaScript. Play video: Fructose, Glucose and Hunger For closed captioning, click the CC ...

  11. CSF glucose test

    Science.gov (United States)

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

  12. Blood Glucose Log

    Science.gov (United States)

    ... here ¢ cut here ¢ If you have high blood glucose , make notes in your log and talk with ... physical activity, or diabetes medicines. Having low blood glucose means that your blood glucose level is too ...

  13. A luminol electrochemiluminescence aptasensor based on glucose oxidase modified gold nanoparticles for measurement of platelet-derived growth factor BB.

    Science.gov (United States)

    Zhang, Jing-Jing; Cao, Jun-Tao; Shi, Gui-Fang; Huang, Ke-Jing; Liu, Yan-Ming; Ren, Shu-Wei

    2015-01-01

    A sandwich-type luminol electrochemiluminescence (ECL) aptasensor for highly sensitive and selective detection of platelet-derived growth factor BB (PDGF-BB) is fabricated. For this proposed ECL aptasensor, a multilayered AuNPs-electrochemically reduced graphene (AuNPs-EG) nanocomposite film was formed on the GCE surface as the base of the aptasensor through a co-electrodeposition method. The AuNPs-EG composites possess high conductivity to promote the electron transfer at the electrode interface and good biocompatibility and large surface area to capture large amounts of primary aptamer (Apt1), thus amplifying the detection response. Moreover, glucose oxidase (GOD) functionalized AuNPs labeled secondary aptamer (GOD-Apt2-AuNPs) was designed as the signal probe for the sandwiched aptasensor. Enhanced sensitivity was obtained by in situ generation of H2O2 from reaction between GOD and glucose and the excellent catalytic behavior of AuNPs to the ECL of the luminol-H2O2 system. Under the optimal conditions, the as-prepared ECL aptasensor exhibited excellent analytical property for the detection of PDGF-BB in the range from 1.0×10(-13) to 5.0×10(-10) mol L(-1) with a detection limit of 1.7×10(-14) mol L(-1) (S/N=3). The application of the present protocol was demonstrated by analyzing PDGF-BB in human serum and human urine samples with the recoveries from 85.0% to 110%. PMID:25476280

  14. Impact of Glucose Tolerance Status, Sex, and Body Size on Glucose Absorption Patterns During OGTTs

    DEFF Research Database (Denmark)

    Faerch, K.; Pacini, G.

    2013-01-01

    OBJECTIVEWe studied whether patterns of glucose absorption during oral glucose tolerance tests (OGTTs) were abnormal in individuals with impaired glucose regulation and whether they were related to sex and body size (height and fat-free mass). We also examined how well differences in insulin sensitivity and -cell function measured by gold-standard tests were reflected in the corresponding OGTT-derived estimates.RESEARCH DESIGN AND METHODSWith validated methods, various aspects of glucose absorption were estimated from 12-point, 3-h, 75-g OGTTs in 66 individuals with normal glucose tolerance (NGT), isolated impaired fasting glucose (i-IFG), or isolated impaired glucose tolerance (i-IGT). Insulin sensitivity and -cell function were measured with the euglycemic-hyperinsulinemic clamp and intravenous glucose tolerance tests, respectively. Surrogate markers of both conditions were calculated from OGTTs.RESULTSMore rapid glucose absorption (P 0.036) and reduced late glucose absorption (P 0.039) were observed in thei-IFG group relative to NGT and i-IGT groups. Women with i-IGT had a lower early glucose absorption than did men with i-IGT (P = 0.041); however, this difference did not persist when differences in body size were taken into account (P > 0.28). Faster glucose absorption was related to higher fasting (P = 0.001) and lower 2-h (P = 0.001) glucose levels and to greater height and fat-free mass (P <0.001). All OGTT-derived measures of insulin sensitivity, but only one of three measures of -cell function, reflected the differences for these parameters between those with normal and impaired glucose regulation as measured by gold-standard tests.CONCLUSIONSGlucose absorption patterns during an OGTT are significantly related to plasma glucose levels and body size, which should be taken into account when estimating -cell function from OGTTs in epidemiological studies.

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

    Science.gov (United States)

    Kiyatkin, Eugene A; Wakabayashi, Ken T

    2015-01-21

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

  16. Glucose kinetics in infants of diabetic mothers

    International Nuclear Information System (INIS)

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

  17. Glucose metabolism in diabetic blood vessels

    Energy Technology Data Exchange (ETDEWEB)

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

    1986-03-05

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

  18. Glucose metabolism in diabetic blood vessels

    International Nuclear Information System (INIS)

    Since glycolysis appears to be coupled to active ion transport in vascular smooth muscle, alterations in glucose metabolism may contribute to cellular dysfunction and angiopathy in diabetes. Uptake and utilization of glucose were studied in perfused blood vessels in which pulsatile flow and perfusion pressure were similar to those measured directly in vivo. Thoracic aortae isolated from 8-wk alloxan diabetic (D) and nondiabetic control rabbits were cannulated, tethered, and perfused with oxygenated buffer containing 7 or 25 mM glucose and tracer amounts of glucose-U-14 C. Norepinephrine (NE) (10-6 M) and/or insulin (I) (150 ?U/ml) and albumin (0.2%) were added. NE-induced tension development increased glucose uptake 39% and 14CO2 and lactate production 2.3-fold. With 7 mM glucose, marked decreases in glucose uptake (74%), 14CO2 (68%), lactate (30%), total tissue glycogen (75%), and tissue phospholipids (70%) were observed in D. Addition of I or elevation of exogenous glucose to 25 mM normalized glucose uptake, but had differential effects on the pattern of substrate utilization. Thus, in D, there was a marked depression of vascular glucose metabolism that was partially reversed by addition of low concentrations of insulin or D levels of glucose

  19. Noise-Enhanced Measurement of Weak Doublet Spectra with a Fourier-Transform Spectrometer and a 1-Bit Analog-to-Digital Converter.

    Science.gov (United States)

    Lim, M; Saloma, C

    2001-04-10

    We demonstrate an efficient noise dithering procedure for measuring the power spectrum of a weak spectral doublet with a Fourier-transform spectrometer in which the subthreshold interferogram is measured by a 1-bit analog-to-digital converter without oversampling. In the absence of noise, no information is obtained regarding the doublet spectrum because the modulation term s(x) of its interferogram is below the instrumental detection limit B, i.e., |s(x)| resonant frequencies of s(x) could be located with high accuracy over a wide range of ?f? and beta values. Signal-to-noise ratios as high as 50 are also gained for the recovered power spectra. The performance of the procedure is also analyzed with respect to another method that recovers the amplitude values of s(x) directly. PMID:18357174

  20. The determination of solubility and diffusion coefficient for solids in liquids by an inverse measurement technique using cylinders of amorphous glucose as a model compound

    Science.gov (United States)

    Hu, Chengyao; Huang, Pei

    2011-05-01

    The importance of sugar and sugar-containing materials is well recognized nowadays, owing to their application in industrial processes, particularly in the food, pharmaceutical and cosmetic industries. Because of the large numbers of those compounds involved and the relatively small number of solubility and/or diffusion coefficient data for each compound available, it is highly desirable to measure the solubility and/or diffusion coefficient as efficiently as possible and to be able to improve the accuracy of the methods used. In this work, a new technique was developed for the measurement of the diffusion coefficient of a stationary solid solute in a stagnant solvent which simultaneously measures solubility based on an inverse measurement problem algorithm with the real-time dissolved amount profile as a function of time. This study differs from established techniques in both the experimental method and the data analysis. The experimental method was developed in which the dissolved amount of solid solute in quiescent solvent was investigated using a continuous weighing technique. In the data analysis, the hybrid genetic algorithm is used to minimize an objective function containing a calculated and a measured dissolved amount with time. This is measured on a cylindrical sample of amorphous glucose in methanol or ethanol. The calculated dissolved amount, that is a function of the unknown physical properties of the solid solute in the solvent, is calculated by the solution of the two-dimensional nonlinear inverse natural convection problem. The estimated values of the solubility of amorphous glucose in methanol and ethanol at 293 K were respectively 32.1 g/100 g methanol and 1.48 g/100 g ethanol, in agreement with the literature values, and support the validity of the simultaneously measured diffusion coefficient. These results show the efficiency and the stability of the developed technique to simultaneously estimate the solubility and diffusion coefficient. Also the influence of the solution density change and the initial concentration conditions on the dissolved amount was investigated by the numerical results using the estimated parameters. It is found that the theoretical assumption to simplify the inverse measurement problem algorithm is reasonable for low solubility.

  1. The determination of solubility and diffusion coefficient for solids in liquids by an inverse measurement technique using cylinders of amorphous glucose as a model compound

    International Nuclear Information System (INIS)

    The importance of sugar and sugar-containing materials is well recognized nowadays, owing to their application in industrial processes, particularly in the food, pharmaceutical and cosmetic industries. Because of the large numbers of those compounds involved and the relatively small number of solubility and/or diffusion coefficient data for each compound available, it is highly desirable to measure the solubility and/or diffusion coefficient as efficiently as possible and to be able to improve the accuracy of the methods used. In this work, a new technique was developed for the measurement of the diffusion coefficient of a stationary solid solute in a stagnant solvent which simultaneously measures solubility based on an inverse measurement problem algorithm with the real-time dissolved amount profile as a function of time. This study differs from established techniques in both the experimental method and the data analysis. The experimental method was developed in which the dissolved amount of solid solute in quiescent solvent was investigated using a continuous weighing technique. In the data analysis, the hybrid genetic algorithm is used to minimize an objective function containing a calculated and a measured dissolved amount with time. This is measured on a cylindrical sample of amorphous glucose in methanol or ethanol. The calculated dissolved amount, that is a function of the unknown physical properties of the solid solute in the solvent, is calculated by the solution of the two-dimensional nonlinear inverse natural convection problem. The estimated values of the solubility of amorphous glucose in methanol and ethanol at 293 K were respectively 32.1 g/100 g methanol and 1.48 g/100 g ethanol, in agreement with the literature values, and support the validity of the simultaneously measured diffusion coefficient. These results show the efficiency and the stability of the developed technique to simultaneously estimate the solubility and diffusion coefficient. Also the influence of the solution density change and the initial concentration conditions on the dissolved amount was investigated by the numerical results using the estimated parameters. It is found that the theoretical assumption to simplify the inverse measurement problem algorithm is reasonable for low solubility

  2. Alternations in salivary glucose during ramadan fasting

    OpenAIRE

    Ali Erfani; Reyhaneh Sariri; Abdolali Varasteh

    2010-01-01

    During the holly month of Ramadan, Muslims fast every day from dawn to sunset. Although the effect of Ramadan fasting on general health has been widely studied, the impact of fasting on oral health and possible changes in salivary biochemicals, such as glucose, has not received much attentiom. The aim of our study was to evaluate the influence of fasting on the level of glucose in the saliva of healthy individuals. Salivary glucose was measured using an enzymatic method based on oxidation of ...

  3. The Impact of Melatonin on Glucose Homeostasis

    OpenAIRE

    Zeynep Arzu Ye?in; Rüya Mutluay; ?ehri Elbeg; Resul Karaku?; Nuri Çak?r

    2009-01-01

    Objective: Melatonin is a pineal product mainly charged with the maintenance of antioxidant conditions in human. This study is performed to identify the short-term effect of melatonin on glucose homeostasis in diabetic patients. Materials and Methods: Melatonin and placebo were given perorally to sixty patients. Blood glucose and insulin levels were measured with constant intervals. Results: No significant correlation was found among the levels of glucose, insulin and HOMA-IR index at any ti...

  4. 21 CFR 864.7360 - Erythrocytic glucose-6-phosphate dehydrogenase assay.

    Science.gov (United States)

    2010-04-01

    ...Erythrocytic glucose-6-phosphate dehydrogenase assay. 864.7360 Section 864.7360 Food...Erythrocytic glucose-6-phosphate dehydrogenase assay. (a) Identification. An erythrocytic glucose-6-phosphate dehydrogenase assay is a device used to measure the...

  5. Analog filters in nanometer CMOS

    CERN Document Server

    Uhrmann, Heimo; Zimmermann, Horst

    2014-01-01

    Starting from the basics of analog filters and the poor transistor characteristics in nanometer CMOS 10 high-performance analog filters developed by the authors in 120 nm and 65 nm CMOS are described extensively. Among them are gm-C filters, current-mode filters, and active filters for system-on-chip realization for Bluetooth, WCDMA, UWB, DVB-H, and LTE applications. For the active filters several operational amplifier designs are described. The book, furthermore, contains a review of the newest state of research on low-voltage low-power analog filters. To cover the topic of the book comprehensively, linearization issues and measurement methods for the characterization of advanced analog filters are introduced in addition. Numerous elaborate illustrations promote an easy comprehension. This book will be of value to engineers and researchers in industry as well as scientists and Ph.D students at universities. The book is also recommendable to graduate students specializing on nanoelectronics, microelectronics ...

  6. Fluorescence Intensity- and Lifetime-Based Glucose Sensing Using Glucose/Galactose-Binding Protein

    OpenAIRE

    Pickup, John C; Khan, Faaizah; Zhi, Zheng-liang; Coulter, Jonathan; Birch, David J. S.

    2013-01-01

    We review progress in our laboratories toward developing in vivo glucose sensors for diabetes that are based on fluorescence labeling of glucose/galactose-binding protein. Measurement strategies have included both monitoring glucose-induced changes in fluorescence resonance energy transfer and labeling with the environmentally sensitive fluorophore, badan. Measuring fluorescence lifetime rather than intensity has particular potential advantages for in vivo sensing. A prototype fiber-optic-bas...

  7. Four grams of glucose

    OpenAIRE

    Wasserman, David H

    2008-01-01

    Four grams of glucose circulates in the blood of a person weighing 70 kg. This glucose is critical for normal function in many cell types. In accordance with the importance of these 4 g of glucose, a sophisticated control system is in place to maintain blood glucose constant. Our focus has been on the mechanisms by which the flux of glucose from liver to blood and from blood to skeletal muscle is regulated. The body has a remarkable capacity to satisfy the nutritional need for glucose, while ...

  8. Enzyme Analysis to Determine Glucose Content

    Science.gov (United States)

    Carpenter, Charles; Ward, Robert E.

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

  9. Alternations in salivary glucose during ramadan fasting

    Directory of Open Access Journals (Sweden)

    Ali Erfani

    2010-07-01

    Full Text Available During the holly month of Ramadan, Muslims fast every day from dawn to sunset. Although the effect of Ramadan fasting on general health has been widely studied, the impact of fasting on oral health and possible changes in salivary biochemicals, such as glucose, has not received much attentiom. The aim of our study was to evaluate the influence of fasting on the level of glucose in the saliva of healthy individuals. Salivary glucose was measured using an enzymatic method based on oxidation of glucose by glucoseoxidase followed by determination of resulting H2O2 in the presence of peroxidase. A reduction in mean concentration of glucose was observed in the saliva of all fasting subjects as compared to the control group. It was concluded that reduction in salivary glucose is mostly due to reduced food intake and may be beneficial to dental health.

  10. Evidence that humans can taste glucose polymers.

    Science.gov (United States)

    Lapis, Trina J; Penner, Michael H; Lim, Juyun

    2014-11-01

    The sense of taste is essential for identifying potential nutrients and poisons. Accordingly, specialized taste receptor cells are activated by food-derived chemicals. Because of its importance in the human diet, oral detection of starch, or its degradation products, would presumably be highly beneficial. Yet, it has long been assumed that simple sugars are the only class of carbohydrates that humans can taste. There is, however, considerable evidence that rodents can taste starch degradation products (i.e., glucose polymers composed of maltooligosaccharides with 3-10 glucose units and maltopolysaccharides with >10 glucose units) and that their detection is independent of the sweet taste receptor, T1R2/T1R3. The present study was designed 1) to measure individual differences in human taste perception of glucose polymers, 2) to understand individual differences in the activity of salivary ?-amylase, and 3) to investigate the role that salivary ?-amylase may play in the taste perception of glucose polymers. In the first experiment, subjects rated taste intensity of glucose, sucrose, NaCl, and glucose polymers of various chain lengths, while their noses were clamped. Saliva samples from the subjects were also collected and their salivary ?-amylase activity was assayed. Results showed that the perceived intensities of glucose, sucrose, and NaCl were significantly correlated (r = 0.75-0.85, P amylase activity among subjects, responsiveness to glucose polymers did not significantly differ between individuals with high and low ?-amylase activity. A follow up experiment was conducted to quantify the concentrations of glucose and maltose that were inherently present in the glucose polymer stimuli and to determine whether the amounts were within a perceptually detectable range. Results revealed that the amounts of simple sugars present in the test stimuli were trivial and were mostly at an undetectable level. These data together provide strong evidence that humans can taste glucose polymers and that the responsiveness to glucose polymers is independent of that to simple sugars. PMID:25326592

  11. Insulin Analogs: Impact on Treatment Success, Satisfaction, Quality of Life, and Adherence

    OpenAIRE

    Hartman, Israel

    2008-01-01

    A growing body of medical research has demonstrated that intensive control of serum glucose levels can minimize the development of diabetes-related complications. Success with insulin management ultimately depends on how closely a given regimen can mimic normal physiologic insulin release patterns. The new insulin analogs, including the rapid-acting analogs (aspart, lispro, glulisine), the long-acting basal analogs (glargine, detemir), and the premixed insulin analog formulations (75% neutral...

  12. Radiometric assays for glycerol, glucose, and glycogen

    International Nuclear Information System (INIS)

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

  13. Strategies for built-in characterization testing and performance monitoring of analog RF circuits with temperature measurements

    International Nuclear Information System (INIS)

    This paper presents two approaches to characterize RF circuits with built-in differential temperature measurements, namely the homodyne and heterodyne methods. Both non-invasive methods are analyzed theoretically and discussed with regard to the respective trade-offs associated with practical off-chip methodologies as well as on-chip measurement scenarios. Strategies are defined to extract the center frequency and 1 dB compression point of a narrow-band LNA operating around 1 GHz. The proposed techniques are experimentally demonstrated using a compact and efficient on-chip temperature sensor for built-in test purposes that has a power consumption of 15 µW and a layout area of 0.005 mm2 in a 0.25 µm CMOS technology. Validating results from off-chip interferometer-based temperature measurements and conventional electrical characterization results are compared with the on-chip measurements, showing the capability of the techniques to estimate the center frequency and 1 dB compression point of the LNA with errors of approximately 6% and 0.5 dB, respectively

  14. Spectral Reflectance Measurements of Sulfides at the Planetary Emissivity Laboratory — Analogs for Hollow-Forming Material on Mercury?

    Science.gov (United States)

    Helbert, J.; Maturilli, A.; D'Amore, M.; Vaughan, W. M.; Head, J. W.; Klima, R. L.; Blewett, D. T.; McCoy, T. J.

    2012-03-01

    We present spectral reflectance measurements at visible and near-infrared wavelengths of fresh and heated samples of MnS, CaS, and MgS, as well as elemental sulfur. We infer that sulfides display a diagnostic feature at or near 0.6 µm.

  15. Glucose effectiveness and insulin sensitivity measurements derived from the non-insulin-assisted minimal model and the clamp techniques are concordant

    DEFF Research Database (Denmark)

    Henriksen, Jan Erik; Alford, Frank

    2010-01-01

    We investigated the concordance between glucose effectiveness (SG) and insulin sensitivity (SI), derived from the unmodified dynamic non-insulin-assisted intravenous glucose tolerance test (IVGTT) implemented by SG(MM) and SI(MM); simulation analysis and modelling/conversational interaction (SAAM/CONSAM) versus the eu/hyperglycaemic basal insulinaemic and the euglycaemic hyperinsulinaemic clamp (SG(CLAMP) and SI(CLAMP)).

  16. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Blood Pressure Physical Activity High Blood Glucose My Health Advisor Tools To Know Your Risk Alert Day ... DKA (Ketoacidosis) & Ketones Kidney Disease (Nephropathy) Gastroparesis Mental Health Treatment & Care Blood Glucose Testing Medication Doctors, Nurses & ...

  17. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Risk Test Lower Your Risk Healthy Eating Overweight Smoking High Blood Pressure Physical Activity High Blood Glucose ... Care Blood Glucose Testing Medication Doctors, Nurses & More Oral Health & Hygiene Women A1C Insulin Pregnancy 8 Tips ...

  18. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... often. Ask your doctor how often you should check and what your blood glucose levels should be. ... your blood glucose is above 240 mg/dl, check your urine for ketones. If you have ketones, ...

  19. Isolation of a Mutant of Kluyveromyces marxianus Resistant to Glucose Repression

    Directory of Open Access Journals (Sweden)

    Moeini Hassan

    2006-01-01

    Full Text Available In this study, we isolated a mutant of Kluyveromyces marxianus resistance to glucose repression. To screen for depression mutants, the strains were treated with UV rays. Fifteen resistant mutant strains were isolated. The mutants were further screened for glucose-repression-resistant mutants in the presence of 2-deoxy-D-glucose, an analog to glucose and lactose as the sole carbon source. In this condition, one glucose-repression-resistant mutant was isolated. The enzyme activity in this mutant strain and the wild type strain was compared using different mediums containing 4% of each lactose and glucose and 2% glucose+2% lactose. The results demonstrated significant decreasing in glucose repression in the mutant strain as compared to the wild type. This mutant was unable to grow anaerobically on glucose in present of antimycin A, the property of rag1 mutants. This mutant is, therefore, capable of constitutive expression of ?-galactosidase, which makes it suitable for industrial purposes.

  20. Cell based metabolic barriers to glucose diffusion: macrophages and continuous glucose monitoring.

    Science.gov (United States)

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

    2014-03-01

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

  1. The BIGTT test : a novel test for simultaneous measurement of pancreatic beta-cell function, insulin sensitivity, and glucose tolerance

    DEFF Research Database (Denmark)

    Hansen, Torben; Drivsholm, Thomas

    2007-01-01

    Insulin resistance and impaired beta-cell function are key elements in the pathogenesis of type 2 diabetes. We aimed to develop valid algorithms for estimation of the insulin sensitivity index (S(I)) and acute insulin response (AIR) derived from simple and cheap physiological measurements that could be used in large-scale metabolic, genetic, and epidemiological studies.

  2. Fructose, Glucose and Hunger

    Medline Plus

    Full Text Available ... medlineplus/videos/news/Fructose_Glucose_051615.html Fructose, Glucose and Hunger HealthDay News Video - May 6, 2015 ... this page, please enable JavaScript. Play video: Fructose, Glucose and Hunger For closed captioning, click the CC ...

  3. Intuitive analog circuit design

    CERN Document Server

    Thompson, Marc

    2013-01-01

    Intuitive Analog Circuit Design outlines ways of thinking about analog circuits and systems that let you develop a feel for what a good, working analog circuit design should be. This book reflects author Marc Thompson's 30 years of experience designing analog and power electronics circuits and teaching graduate-level analog circuit design, and is the ideal reference for anyone who needs a straightforward introduction to the subject. In this book, Dr. Thompson describes intuitive and ""back-of-the-envelope"" techniques for designing and analyzing analog circuits, including transistor amplifi

  4. The analog readout of the LHCb vertex detector and study of the measurement of the B$_s$ oscillation frequency

    CERN Document Server

    Borel, J

    2008-01-01

    The LHCb detector is one of the four experimental setups built to detect high-energy proton collisions to be produced by the Large Hadron Collider (LHC). Located at CERN (Geneva, Switzerland), the LHC machine and the LHCb experiment are expected to start in 2008, and will then operate for several years. Being the largest collider of its kind, the LHC will open the way to new investigations, in the very-high energies, but also in terms of statistics for the study of rare-phenomena and flavor physics. In this framework LHCb is dedicated to precise measurements of CP-violating and rare decays of beauty hadrons, in order to test (or over-constrain) the Standard Model of particle physics. From the hardware point of view, the construction of such detectors represents several challenges; one of them is the routing at a very high frequency of many signals in a harsh radiation environment. We designed to this purpose a hardware setup and a software filter which together reduce the cross-talk present in the readout of ...

  5. Performance of response scales of activity and functional measures of ankylosing spondylitis: numerical rating scale versus visual analog scale.

    Science.gov (United States)

    Akad, Kivanc; Solmaz, Dilek; Sari, Ismail; Onen, Fatos; Akkoc, Nurullah; Akar, Servet

    2013-10-01

    The aim of this study was to compare the performance characteristics of two answer modalities for BASDAI and BASFI in patients with AS and to show validity and reliability of NRS in Turkish version. BASDAI and BASFI were simultaneously employed with a 10-cm VAS and an 11-point NRS. Internal consistency was assessed by using Cronbach's alpha coefficients. Testing was performed on baseline and next day under standardized conditions. Construct validity was determined by association of these measures with ASDAS, DFI, global disease activity, pain scores, ASQOL, HAQ, and SF-36. We also tested the ability of NRS version of BASDAI and BASFI to detect changes. A total 114 patients with AS according to the modified New York criteria were included. There was a good agreement between the total scores of each instrument on day 0 (ICC values were 0.894-0.934). Scores of the both answering modality of each instrument were correlated with ASDAS-CRP, and the scores of DFI, patient global assessment of disease activity and patient-reported pain, ASQOL, HAQ. Response time for BASDAI and BASFI was significantly shorter in NRS answer modality (P < 0.001). Our patients found NRS modality more comprehensible and easier to understand (P < 0.001). Our results showed the validity of NRS version of BASDAI and BASFI and provided an evidence for using these questionnaires in 11-point NRS answer modality in Turkish AS patients. PMID:23736275

  6. Glucose turnover, gluconeogenesis from glycerol, and estimation of net glucose cycling in cancer patients

    International Nuclear Information System (INIS)

    A double isotope method was used in patients with progressive malignancy and in control patients to measure: glucose turnover, conversion rate of carbon skeleton of glycerol into glucose, and the interorgan cycling of glucose carbons (Cori-cycle plus alanine-glucose cycle). [U-14C]glycerol and [6-3H]glucose were given intravenously as a single dose injection. The time course of the specific radioactivities of [6-3H] and [U-14C]glucose was followed in blood. The pool size and the turnover rate of glucose were increased in the cancer group as compared with the control patients. The net recycling of glucose carbons was not increased in the cancer group, despite the increased turnover of glucose. The alterations in the metabolism of glucose did not correlate with the plasma levels of insulin or thyroid hormones (T4, T3, rT3) neither in the entire cancer group nor in those cancer patients who were repeatedly investigated at different intervals of time. The turnover rate of glucose in the cancer patients correlated inversely to their body weight index. The gluconeogenesis rate, given as the fractional conversion rate of the injected radioactive dose of [14C]glycerol, or as mol glucose . kg body weight-1 . day-1, was increased in the cancer group, but still contributed only 3% of the glucose turnover rate in both cancer and control patients. We conclude that an increased gluconeogenesis from glycerol is not significant igenesis from glycerol is not significant in terms of energy expenditure in patients with progressive malignancy, as has previously been concluded for the gluconeogenesis from alanine. It seems that increased turnover of glucose may contribute to inappropriately high energy expenditure in cancer patients

  7. Prognostic significance of the Complex "Visceral Adiposity Index" vs. simple anthropometric measures: Tehran lipid and glucose study

    OpenAIRE

    Mohammadreza Bozorgmanesh; Farzad Hadaegh; Davoud Khalili; Prof Azizi

    2012-01-01

    Abstract Background Visceral adiposity index (VAI) has recently been suggested to be used as a surrogate of visceral adiposity. We examined if VAI could improve predictive performances for CVD of the Framingham's general CVD algorithm (a multivariate model incorporating established CVD risk factors). We compared the predictive abilities of the VAI with those of simple anthropometric measures i.e. BMI, waist-to-height ratio (WHtR) or waist-to-hip ratio (WHpR). Design and methods In a nine-year...

  8. Comparison of daily glucose excursion by continuous glucose monitoring between type 2 diabetic patients receiving preprandial insulin aspart or postprandial insulin glulisine.

    Science.gov (United States)

    Ohta, Akio; Arai, Kaori; Nishine, Ami; Sada, Yoshiyuki; Kato, Hiroyuki; Fukuda, Hisashi; Asai, Shiko; Nagai, Yoshio; Katabami, Takuyuki; Tanaka, Yasushi

    2013-01-01

    Insulin glulisine (Glu) is a rapidly-acting insulin analog with a faster onset of action than the other insulin analogs of its class, which are insulin aspart (Asp) and insulin lispro (Lisp). While insulin Glu is usually injected just before meals, postprandial injection may help to avoid unexpected postprandial hypoglycemia or hyperglycemia by adjusting the insulin dosage according to food intake. However, the effect of postprandial insulin Glu on the glucose profile has not been evaluated. The aim of this study was to compare daily glucose excursion by continuous glucose monitoring (CGM) between multiple daily doses of preprandial insulin Asp or postprandial insulin Glu. In a randomized cross-over trial, we performed CGM to evaluate the 48-hour glucose profile during treatment with the same dosage of insulin Asp just before each meal in 12 hospitalized patients with type 2 diabetes. Patients also received the same dosage of long-acting insulin glargine at bedtime. The average glucose level, standard deviation of the glucose level, mean amplitude of glucose excursion, and daily glucose profile did not differ between preprandial Asp and postprandial Glu. The incidence of hypoglycemic episodes (glucose level<70 mg/dL with or without symptoms) and the area under the curve of glucose<70 mg/dL also did not differ between the two insulin regimens. Multiple daily injections of preprandial Asp and postprandial Glu achieved the same daily glucose excursion profile. Postprandial injection of Glu may provide greater flexibility for patients who require insulin therapy. PMID:23047542

  9. Are polymers suitable rock analogs?

    Science.gov (United States)

    ten Grotenhuis, Saskia M.; Piazolo, Sandra; Pakula, T.; Passchier, Cees W.; Bons, Paul D.

    2002-05-01

    To evaluate if a polymer is suitable for analog modeling, it is essential to know the rheological properties of the material. Polymers used in analog modeling exhibit a complex rheological behavior; only part of which has been taken into account in most modeling studies. The mechanical behavior is strongly dependent on strain rate and temperature, and is characterized by specific dependencies of the storage and loss moduli, related to the elasticity and viscosity, on the deformation rate (frequency). We have measured the storage and loss moduli at a broad range of strain rates and strains, using an oscillatory parallel-disk rheometer. Investigated materials are polydimethylsiloxane (PDMS), mixtures of PDMS and BaSO 4 (filler), Rhodorsil Gomme and mixtures of Rhodorsil Gomme and plastilina, all commonly used in analog experiments. Our measurements show that the rheological properties of mixtures of plastilina and Rhodorsil Gomme depend on its deformation history. Therefore, these mixtures are problematic for analog modeling. For mixtures of PDMS and BaSO 4, the significance of the elastic component increases with increasing filler content, and accordingly, these mixtures have a limited application for modeling of viscous deformation. Pure PDMS and Rhodorsil Gomme exhibit Newtonian flow behavior at strain rates commonly used in analog modeling.

  10. Glucose-dependent Insulinotropic Polypeptide : Blood Glucose Stabilizing Effects in Patients With Type 2 Diabetes

    DEFF Research Database (Denmark)

    Christensen, Mikkel B; Calanna, Salvatore

    2014-01-01

    CONTEXT: Patients with type 2 diabetes mellitus (T2DM) have clinically relevant disturbances in the effects of the hormone glucose-dependent insulinotropic polypeptide (GIP). OBJECTIVE: We aimed to evaluate the importance of the prevailing plasma glucose levels for the effect of GIP on responses of glucagon and insulin and glucose disposal in patients with T2DM. DESIGN AND SETTING: We performed a single center, placebo-controlled, cross-over, experimental study. PATIENTS: We studied twelve patients with T2DM (age: 62 ± 1 years [mean ± SEM], body mass index: 29 ± 1 kg/m(2); glycosylated hemoglobin A1c: 6.5 ± 0.1% [48 ± 2 mmol/mol]). INTERVENTION: We infused physiological amounts of GIP (2 pmol × kg(-1) × min(-1)) or saline. MAIN OUTCOME MEASURES: We measured plasma concentrations of glucagon, glucose, insulin, C-peptide, intact GIP, and amounts of glucose needed to maintain glucose clamps. RESULTS: During fasting glycemia (plasma glucose ?8 mmol/L), GIP elicited significant increments in both insulin andglucagon levels, resulting in neutral effects on plasma glucose. During insulin-induced hypoglycemia (plasma glucose ?3 mmol/L), GIP elicited a minor early-phase insulin response and increased glucagon levels during the initial 30 minutes, resulting in less glucose needed to be infused to maintain the clamp (29 ± 8 vs 49 ± 12 mg × kg(-1), P < .03). During hyperglycemia (1.5 × fasting plasma glucose ?12 mmol/L), GIP augmented insulin secretion throughout the clamp, with slightly less glucagon suppression compared with saline, resulting in more glucose needed to maintain the clamp during GIP infusions (265 ± 21 vs 213 ± 13 mg × kg(-1), P < .001). CONCLUSIONS: In patients with T2DM, GIP counteracts insulin-induced hypoglycemia, most likely through a predominant glucagonotropic effect. In contrast, during hyperglycemia, GIP increases glucose disposal through a predominant effect on insulin release.

  11. Optical coherence tomography and noninvasive blood glucose monitoring: a review

    Science.gov (United States)

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

    2004-08-01

    Effective treatment and management of diabetic disease require frequent or continuous monitoring of blood glucose concentration. Currently used methods for monitoring of the blood glucose are invasive and, therefore, are not suitable for the frequent measurements. In this paper we review our recent results on development of Optical Coherence Tomography technique for noninvasive monitoring of glucose concentration in skin.

  12. Imaging atherosclerosis in the carotid arteries with F-18-Fluoro-2-deoxy-D-glucose positron emission tomography: effect of imaging time after injection on quantitative measurement

    Energy Technology Data Exchange (ETDEWEB)

    Oh, Min Young; Kim, Ji Young; Shin, Kwang Ho; Park, Seol Hoon; Ryu, Jin Sook; Kim, Jae Seung; Kim, Hye Jin; Kang, Dong Wha; Moon, Dae Hyuk [University of Ulsan College of Medicine, Asan Medical Center, Seoul (Korea, Republic of)

    2010-12-15

    To compare F-18-fluoro-2-deoxy-D-glucose (F-18 FDG) positron emission tomography/computed tomography (PET/CT) imaging at two different circulation times after injection of F-18 FDG in order to measure atherosclerosis in carotid arteries. We assessed 12 patients with recent symptomatic plaques in the carotid arteries. F-18 FDG PET/CT carotid plaque imaging was performed for 20 min at 2 h after F-18 FDG injection in five patients and at 3 h in seven patients. We measured vessel wall uptake using the maximal standardized uptake value (SUV), and the mean and maximal blood target-to-background ratios (TBR) of the symptomatic carotid arteries. Blood pool activity (BPA) was measured as the mean SUV of the superior vena cava (SVC) and jugular vein of these 12 patients, and in 14 age-and gender-matched patients who underwent whole-body F-18 FDG PET/CT examinations 1 h after injection. F-18 FDG PET/CT revealed visible F-18 FDG uptake in all patients with symptomatic carotid plaques. Maximal SUV did not differ between groups evaluated at 2 h and 3 h (2.62{+-}0.45 vs 3.00{+-}0.85, p=0.335). However mean (2.04{+-}0.22 vs 3.54{+-}0.62, p<0.05) and maximal (1.65{+-}0.15 vs 2.70{+-}0.42, p<0.05) TBR values that were normalized to BPA in the SVC differ significantly. Symptomatic carotid plaques are visualized for a relatively short period of imaging time on {>=}1-h PET/CT images. Quantitative parameters of atherosclerotic carotid arteries are preserved or even increased over time, whereas those of blood pools are decreased

  13. Detecting early kidney damage in horses with colic by measuring matrix metalloproteinase -9 and -2, other enzymes, urinary glucose and total proteins

    Directory of Open Access Journals (Sweden)

    Salonen Hanna

    2007-01-01

    Full Text Available Abstract Background The aim of the study was to investigate urine matrix metalloproteinase (MMP-2 and -9 activity, alkaline phosphatase/creatinine (U-AP/Cr and gamma-glutamyl-transpeptidase/creatinine (U-GGT/Cr ratios, glucose concentration, and urine protein/creatinine (U-Prot/Cr ratio and to compare data with plasma MMP-2 and -9 activity, cystatin-C and creatinine concentrations in colic horses and healthy controls. Horses with surgical colic (n = 5 were compared to healthy stallions (n = 7 that came for castration. Blood and urine samples were collected. MMP gelatinolytic activity was measured by zymography. Results We found out that horses with colic had significantly higher urinary MMP-9 complex and proMMP-9 activities than horses in the control group. Colic horses also had higher plasma MMP-2 activity than the control horses. Serum creatinine, although within reference range, was significantly higher in the colic horses than in the control group. There was no significant increase in urinary alkaline phosphatase, gamma-glutamyltranspeptidase or total proteins in the colic horses compared to the control group. A human cystatin-C test (Dako Cytomation latex immunoassay® based on turbidimetry did not cross react with equine cystatin-C. Conclusion The results indicate that plasma MMP-2 may play a role in the pathogenesis of equine colic and urinary MMP-9 in equine kidney damage.

  14. Prognostic significance of the Complex "Visceral Adiposity Index" vs. simple anthropometric measures: Tehran lipid and glucose study

    Directory of Open Access Journals (Sweden)

    Mohammadreza Bozorgmanesh

    2012-03-01

    Full Text Available Abstract Background Visceral adiposity index (VAI has recently been suggested to be used as a surrogate of visceral adiposity. We examined if VAI could improve predictive performances for CVD of the Framingham's general CVD algorithm (a multivariate model incorporating established CVD risk factors. We compared the predictive abilities of the VAI with those of simple anthropometric measures i.e. BMI, waist-to-height ratio (WHtR or waist-to-hip ratio (WHpR. Design and methods In a nine-year population-based follow-up, 6 407 (2 778 men participants, free of CVD at baseline, aged ? 30 years were eligible for the current analysis. The risk of CVD was estimated by incorporating VAI, BMI, WHpR, and WHtR, one at a time, into multivariate accelerated failure time models. Results We documented 534 CVD events with the annual incidence rate (95%CIs being 7.3 (6.4-8.3 among women and 13.0 (11.7-14.6 among men. Risk of future CVD increased with increasing levels of VAI among both men and women. VAI was associated with multivariate-adjusted increased risk of incident CVD among women. However, the magnitude of risk conferred by VAI was not significantly higher than those conferred by BMI, WHpR, or WHtR. Among men, after adjustment for established CVD risk factors, VAI was no longer associated with increased risk of CVD. VAI failed to add to the predictive ability of the Framingham general CVD algorithm. Conclusions Using VAI instead of simple anthropometric measures may lead to loss of much information needed for predicting incident CVD.

  15. Total and high molecular weight (HMW) adiponectin levels and measures of glucose and lipid metabolism following pioglitazone treatment in a randomized placebo-controlled study in polycystic ovary syndrome

    DEFF Research Database (Denmark)

    Glintborg, D.; Frystyk, J.

    2008-01-01

    OBJECTIVE: Recent studies suggested that the effect of adiponectin on insulin-stimulated glucose metabolism is mediated primarily by the high molecular weight (HMW) form of adiponectin. In the present study we evaluated total and HMW adiponectin in polycystic ovary syndrome (PCOS) patients and controls and examined possible mechanisms for increased insulin sensitivity during pioglitazone treatment. STUDY SUBJECTS: Thirty PCOS patients randomized to pioglitazone, 30 mg/day, or placebo for 16 weeks and 14 weight-matched healthy females were studied. DESIGN: Total and HMW adiponectin levels were measured, and euglycaemic hyperinsulinaemic clamps and indirect calorimetry were performed. Delta-values denoted changes during pioglitazone treatment (16 weeks--basal). RESULTS: Pretreatment adiponectin levels were decreased in PCOS patients vs. controls (P < 0.05), whereas no significant differences were found in HMW adiponectin levels. Following pioglitazone treatment, total and HMW adiponectin increased (all P < 0.05), whereas no significant changes were observed with placebo. Delta-total adiponectin levels correlated positively with the rate of Delta-insulin-stimulated glucose disposal (R(d)) (r = 0.89) and Delta-oxidative glucose metabolism (r = 0.71) and inversely with Delta-fasting free fatty acid (FFA) levels (r = -0.69) and Delta-lipid oxidation (r = -0.73) during insulin stimulation (all P < 0.01). Weaker correlations were found between Delta-HMW adiponectin levels and Delta-measures of glucose and lipid metabolism during insulin stimulation than with Delta-total adiponectin. CONCLUSION: A close correlation between increased total adiponectin levels and increased insulin-stimulated glucose metabolism during pioglitzone treatment supports the hypothesis that the insulin-sensitizing effect of pioglitazone in PCOS is, at least in part, mediated by adiponectin. Measures of changes in HMW adiponectin did not add further information to this relationship Udgivelsesdato: 2008/2

  16. Overview of a Novel Sensor for Continuous Glucose Monitoring

    OpenAIRE

    Schmelzeisen-Redeker, Günther; Staib, Arnulf; Strasser, Monika; Müller, Ulrich; Schoemaker, Michael

    2013-01-01

    The core element of a continuous glucose monitoring (CGM) system is the glucose sensor, which should enable reliable CGM readings in the interstitial fluid in subcutaneous tissue for a period of several days. The aim of this article is to describe the layout and constituents of a novel glucose sensor and the rationale behind the measures that were used to optimize its performance. In order to achieve a stable glucose sensor signal, special attention was paid to the sensor materials and archit...

  17. Glucose-dependent Insulinotropic Polypeptide : Blood Glucose Stabilizing Effects in Patients with Type 2 diabetes

    DEFF Research Database (Denmark)

    Christensen, Mikkel; Calanna, Salvatore

    2013-01-01

    Context. Patients with type 2 diabetes mellitus (T2DM) have clinically relevant disturbances in the effects of the hormone glucose-dependent insulinotropic polypeptide (GIP). Objective. To evaluate the importance of the prevailing plasma glucose levels for the effect of GIP on responses of glucagon and insulin and glucose disposal in patients with T2DM. Design. A placebo-controlled, cross-over, experimental study. Settings. Copenhagen University hospital Gentofte. Patients. Twelve patients with T2DM (age: 62±1 years (mean±SEM), BMI: 29±1 kg/m(2); HbA1c: 6.5±0.1% (48±2 mmol/mol)). Intervention. Iv infusions of physiological amounts of GIP (2 pmol×kg(-1)×min(-1)) or saline. Main Outcome Measures. Plasma concentrations of glucagon, glucose, insulin, C-peptide, intact GIP and amounts of glucose needed to maintain glucose clamps. Results. During fasting glycemia (plasma glucose ?8 mmol/l), GIP elicited significant increments in both insulin and glucagon levels resulting in neutral effects on plasma glucose. Duringinsulin-induced hypoglycemia (plasma glucose ?3 mmol/l), GIP elicited a minor early-phase insulin response and increased glucagon levels during the initial 30 minutes resulting in less glucose needed to be infused to maintain the clamp (29±8 vs. 49±12 mg×kg(-1), p

  18. New Insights into Cytosolic Glucose Levels during Differentiation of 3T3-L1 Fibroblasts into Adipocytes*

    OpenAIRE

    Kovacic, Petra Brina; Chowdhury, Helena H.; Velebit, Jelena; Kreft, Marko; Jensen, Jørgen; Zorec, Robert

    2011-01-01

    Cytosolic glucose concentration reflects the balance between glucose entry across the plasma membrane and cytosolic glucose utilization. In adipocytes, glucose utilization is considered very rapid, meaning that every glucose molecule entering the cytoplasm is quickly phosphorylated. Thus, the cytosolic free glucose concentration is considered to be negligible; however, it was never measured directly. In the present study, we monitored cytosolic glucose dynamics in 3T3-L1 fibroblasts and adipo...

  19. Associations between features of glucose exposure and A1C : the A1C-Derived Average Glucose (ADAG) study

    DEFF Research Database (Denmark)

    Borg, Rikke; Kuenen, Judith C

    2010-01-01

    OBJECTIVE: Various methods are used to quantify postprandial glycemia or glucose variability, but few have been compared and none are standardized. Our objective was to examine the relationship among common indexes of postprandial glycemia, overall hyperglycemia, glucose variability, and A1C using detailed glucose measures obtained during everyday life and to study which blood glucose values of the day provide the strongest prediction of A1C. RESEARCH DESIGN AND METHODS: In the A1C-Derived Average Glucose (ADAG) study, glucose levels were monitored in 507 participants (268 type 1 diabetic, 159 type 2 diabetic, and 80 nondiabetic subjects) with continuous glucose monitoring (CGM) and frequent self-monitoring of blood glucose (SMBG) during 16 weeks. We calculated several indexes of glycemia and analyzed their intercorrelations. The association between glucose measurements at different times of the day (pre- and postprandial) and A1C was examined using multiple linear regression. RESULTS: Indexes of glucose variability showed strong intercorrelation. Among postprandial indexes, the area under the glucose curve calculated from CGM 2 h after a meal correlated well with the 90-min SMBG postprandial measurements. Fasting blood glucose (FBG) levels were only moderately correlated with indexes of hyperglycemia and average or postprandial glucose levels. Indexes derived with SMBG strongly correlated with those from CGM. Some SMBG time points had a stronger association with A1C than others. Overall, preprandial glucose values had a stronger association with A1C than postprandial values for both diabetes types, particularly for type 2 diabetes. CONCLUSIONS: Indexes of glucose variability and average and postprandial glycemia intercorrelate strongly within each category. Variability indexes are weakly correlated with the other categories, indicating that these measures convey different information. FBG is not a clear indicator of general glycemia. Preprandial glucose values have a larger impact on A1C levels than postprandial values.

  20. Statins impair glucose uptake in tumor cells.

    Science.gov (United States)

    Malenda, Agata; Skrobanska, Anna; Issat, Tadeusz; Winiarska, Magdalena; Bil, Jacek; Oleszczak, Bozenna; Sinski, Maciej; Firczuk, Ma?gorzata; Bujnicki, Janusz M; Chlebowska, Justyna; Staruch, Adam D; Glodkowska-Mrowka, Eliza; Kunikowska, Jolanta; Krolicki, Leszek; Szablewski, Leszek; Gaciong, Zbigniew; Koziak, Katarzyna; Jakobisiak, Marek; Golab, Jakub; Nowis, Dominika A

    2012-04-01

    Statins, HMG-CoA reductase inhibitors, are used in the prevention and treatment of cardiovascular diseases owing to their lipid-lowering effects. Previous studies revealed that, by modulating membrane cholesterol content, statins could induce conformational changes in cluster of differentiation 20 (CD20) tetraspanin. The aim of the presented study was to investigate the influence of statins on glucose transporter 1 (GLUT1)-mediated glucose uptake in tumor cells. We observed a significant concentration- and time-dependent decrease in glucose analogs' uptake in several tumor cell lines incubated with statins. This effect was reversible with restitution of cholesterol synthesis pathway with mevalonic acid as well as with supplementation of plasma membrane with exogenous cholesterol. Statins did not change overall GLUT1 expression at neither transcriptional nor protein levels. An exploratory clinical trial revealed that statin treatment decreased glucose uptake in peripheral blood leukocytes and lowered (18)F-fluorodeoxyglucose ((18)F-FDG) uptake by tumor masses in a mantle cell lymphoma patient. A bioinformatics analysis was used to predict the structure of human GLUT1 and to identify putative cholesterol-binding motifs in its juxtamembrane fragment. Altogether, the influence of statins on glucose uptake seems to be of clinical significance. By inhibiting (18)F-FDG uptake, statins can negatively affect the sensitivity of positron emission tomography, a diagnostic procedure frequently used in oncology. PMID:22577346

  1. Statins Impair Glucose Uptake in Tumor Cells

    Directory of Open Access Journals (Sweden)

    Agata Malenda

    2012-04-01

    Full Text Available Statins, HMG-CoA reductase inhibitors, are used in the prevention and treatment of cardiovascular diseases owing to their lipid-lowering effects. Previous studies revealed that, by modulating membrane cholesterol content, statins could induce conformational changes in cluster of differentiation 20 (CD20 tetraspanin. The aim of the presented study was to investigate the influence of statins on glucose transporter 1 (GLUT1-mediated glucose uptake in tumor cells. We observed a significant concentration- and time-dependent decrease in glucose analogs' uptake in several tumor cell lines incubated with statins. This effect was reversible with restitution of cholesterol synthesis pathway with mevalonic acid as well as with supplementation of plasma membrane with exogenous cholesterol. Statins did not change overall GLUT1 expression at neither transcriptional nor protein levels. An exploratory clinical trial revealed that statin treatment decreased glucose uptake in peripheral blood leukocytes and lowered 18F-fluorodeoxyglucose (18F-FDG uptake by tumor masses in a mantle cell lymphoma patient. A bioinformatics analysis was used to predict the structure of human GLUT1 and to identify putative cholesterol-binding motifs in its juxtamembrane fragment. Altogether, the influence of statins on glucose uptake seems to be of clinical significance. By inhibiting 18F-FDG uptake, statins can negatively affect the sensitivity of positron emission tomography, a diagnostic procedure frequently used in oncology.

  2. Fast multichannel analog storage system

    International Nuclear Information System (INIS)

    A Multichannel Analog Storage System based on a commercial 32-channel parallel in/serial out (PISO) analog shift register is described. The basic unit is a single width CAMAC module containing 512 analog cells and the associated logic for data storage and subsequent readout. At sampling rates of up to 30 MHz the signals are strobed directly into the PISO. At higher rates signals are strobed into a fast presampling stage and subsequently transferred in block form into an array of PISO's. Sampling rates of 300 MHz have been achieved with the present device and 1000 MHz are possible with improved signal drivers. The system is well suited for simultaneous handling of many signal channels with moderate numbers of samples in each channel. RMS noise over full scale signal has been measured as 1:3000 (approx. = 11 bit). However, nonlinearities in the response and differences in sensitivity of the analog cells require an elaborate calibration system in order to realize 11 bit accuracy for the analog information

  3. Wireless glucose monitoring watch enabled by an implantable self-sustaining glucose sensor system

    Science.gov (United States)

    Rai, Pratyush; Varadan, Vijay K.

    2012-10-01

    Implantable glucose sensors can measure real time blood glucose as compared to conventional techniques involving drawing blood samples and in-vitro processing. An implantable sensor requires energy source for operation with wire inout provision for power and sending signals. Implants capable of generation-transmission of sensory signals, with minimal or no power requirement, can solve this problem. An implantable nanosensor design has been presented here, which can passively detect glucose concentration in blood stream and transmit data to a wearable receiver-recorder system or a watch. The glucose sensitive component is a redox pair of electrodes that generates voltage proportional to glucose concentration. The bio-electrode, made of carbon nanotubes-enzyme nanocluster, has been investigated because of the large surface area for taping electrical signals. This glucose sensor can charge a capacitor, which can be a part of a LCR resonance/inductive coupling based radio frequency (RF) sensor telemetry. Such a system can measure change in glucose concentration by the induced frequency shift in the LCR circuit. A simultaneous power transmission and signal transmission can be achieved by employing two separate LCR oscillating loops, one for each operation. The corresponding coupling LCR circuits can be housed in the wearable receiving watch unit. The data logged in this glucose monitoring watch can be instrumental in managing blood glucose as trigger for an insulin dispensing payload worn on person or implanted.

  4. Ophthalmic glucose monitoring using disposable contact lenses.

    Science.gov (United States)

    Geddes, Chris

    2004-01-01

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

  5. Detecção de trombose venosa em retalhos livres por medidas de glicemia capilar Detection of venous thrombosis in free flaps by measurement of capillary blood glucose

    Directory of Open Access Journals (Sweden)

    Lincoln Saito Millan

    2012-12-01

    Full Text Available INTRODUÇÃO: A monitorização do retalho livre após a cirurgia é de vital importância, especialmente nas primeiras horas de pós-operatório, pois o momento de reabordagem pode ser o definidor entre o salvamento ou a perda do retalho. Até o momento, não existe trabalho na literatura estudando a decisão de abordagem do retalho baseada em medidas objetivas ou a comparação da glicemia entre retalhos que evoluíram bem com os que sofreram sofrimento vascular. O objetivo deste estudo é avaliar a validade da medida da glicemia capilar do retalho como método de monitorização de retalhos microcirúrgicos comparando com a avaliação clínica. MÉTODO: Foram estudados prospectivamente 16 pacientes portadores de retalhos livres, realizados de maio de 2012 a julho de 2012. A glicemia capilar foi avaliada por equipe formada por profissionais não envolvidos com a cirurgia realizada. A avaliação clínica do retalho foi realizada no pós-operatório imediato, na chegada à UTI, a cada 3 horas e sempre que necessário. RESULTADOS: Dos 16 pacientes, 5 (31,3% apresentaram complicações nas primeiras 24 horas. Todas as complicações observadas foram trombose venosa. Foi observada diferença estatisticamente significante na glicemia capilar de portadores de retalhos que apresentaram trombose venosa em comparação àqueles que não tiveram a complicação, nas medidas realizadas 6 horas, 9 horas e 12 horas após a operação (P BACKGROUND: Monitoring of free flaps after surgery is vitally important, especially in the first few hours because the timing of reoperation can determine flap salvage or loss. To date, no study has examined the decision to reoperate on a flap based on the objective measure of glycemia or a comparison between flaps that showed good outcomes and those that showed vascular damage. The objective of this study was to evaluate the validity of blood glucose measurements within the flap as a method for monitoring free flaps and to compare the efficacy of this method with that of clinical assessments. METHODS: The study was prospective, included 16 patients with free flaps, and was conducted from May 2012 to July 2012. A team of professionals not involved in the surgery evaluated capillary glycemia. Flaps were clinically evaluated during the immediate postoperative period, on ICU admission, at every 3 hours, and as needed. RESULTS: Of the 16 patients, 5 (31.3% had venous thrombosis in the first 24 hours. Statistically significant differences were noted in capillary glycemia in patients with or without venous thrombosis in measurements obtained 6, 9, and 12 hours after surgery (P < 0.05. CONCLUSIONS: The measurement of capillary glycemia was not superior to clinical evaluation by an experienced professional for the detection of venous thrombosis within free flaps.

  6. Glucose-Insulin

    Science.gov (United States)

    Maryland Virtual High School

    Glucose is the vehicle by which energy gets from digested food to the cells of the body. In Type I diabetes mellitus, insufficient insulin is available to help get glucose out of the blood and into the cells of the body. This activity has been designed so that students can investigate the negative feedback loop between blood glucose and insulin, one of the mechanisms designed to maintain homeostasis in the human body.

  7. Glucose metabolism in a rat mammary adenocarcinoma

    International Nuclear Information System (INIS)

    Full text: Tumor hypoxia, which decreases therapy response is common in tumors. Glucose metabolism is closely tied to tumor oxygenation and alteration of its metabolism could improve tumor oxygenation. The objective of the study was to compare tissue pharmacokinetics of 14C-2-deoxyglucose (14C2DG) and 14C-glucose in an adenocarcinoma (R3230Ac) and normal control tissue (subcutis:SQ) using a novel fiberoptic scintillation detector. Fischer 344 rats with R3230Ac tumors were anesthetized with Isoflurane and detectors were inserted. Baseline data was acquired for 45 minutes, then 14C2DG or 14C-glucose (i.v.) was injected and data was acquired for 3 hours. After 100mCi of 14C2DG both tissues reached peaks (R3230Ac, 0.4mCi/g; SQ, 0.75mCi/g) 20 minutes post-injection that remained stable for 3 hours. With 200mCi 14C2DG R3230Ac peaked and plateaued at 1.75mCi/g by 50 minutes. SQ peaked (2.25mCi/g) at 20 minutes and decreased to a stable plateau (0.75mCi/g) at 50 minutes. Kinetics of 14C-glucose were different from 14C2DG. R3230Ac and SQ increased over 20 minutes, reaching peaks of 2.4mCi/g and 1.5mCi/g, respectively. A slow decrease followed, but tumor signal (1.25mCi/g) remained higher than SQ (0.5mCi/g). Kinetics of 14C2DG and 14C-glucose were distinctly different. In SQ a wash-in/wash-out effect was observed at 200mCi of 14C2DG. In tumor 00mCi of 14C2DG. In tumor 14C2DG accumulated to a plateau (1.75mCi/g) that persisted out to 3 hours. 14C-glucose signal declined below 14C2DG signal in both tissues, suggesting they both metabolize 14C-glucose and excrete 14C-containing metabolites. PET can assess flouride-deoxyglucose uptake in tumors, which is analogous to our 14C2DG studies. However, PET cannot provide data on glucose metabolism and excretion because there is not a metabolizable fluorinated-glucose analogue that is imageable by PET. In summary, this novel detector has the unique capability to evaluate real-time accumulation, metabolism, and excretion of radiolabeled glucose in tissues before and after metabolic manipulation

  8. Detecção de trombose venosa em retalhos livres por medidas de glicemia capilar / Detection of venous thrombosis in free flaps by measurement of capillary blood glucose

    Scientific Electronic Library Online (English)

    Lincoln Saito, Millan; Luiz Carlos, Ishida; Esther Mihwa Oh, Choi; Enio Cesar, Giacchetto Junior; Teng Hsiang, Wei; Rames, Mattar Júnior; Marcus Castro, Ferreira.

    2012-12-01

    Full Text Available INTRODUÇÃO: A monitorização do retalho livre após a cirurgia é de vital importância, especialmente nas primeiras horas de pós-operatório, pois o momento de reabordagem pode ser o definidor entre o salvamento ou a perda do retalho. Até o momento, não existe trabalho na literatura estudando a decisão [...] de abordagem do retalho baseada em medidas objetivas ou a comparação da glicemia entre retalhos que evoluíram bem com os que sofreram sofrimento vascular. O objetivo deste estudo é avaliar a validade da medida da glicemia capilar do retalho como método de monitorização de retalhos microcirúrgicos comparando com a avaliação clínica. MÉTODO: Foram estudados prospectivamente 16 pacientes portadores de retalhos livres, realizados de maio de 2012 a julho de 2012. A glicemia capilar foi avaliada por equipe formada por profissionais não envolvidos com a cirurgia realizada. A avaliação clínica do retalho foi realizada no pós-operatório imediato, na chegada à UTI, a cada 3 horas e sempre que necessário. RESULTADOS: Dos 16 pacientes, 5 (31,3%) apresentaram complicações nas primeiras 24 horas. Todas as complicações observadas foram trombose venosa. Foi observada diferença estatisticamente significante na glicemia capilar de portadores de retalhos que apresentaram trombose venosa em comparação àqueles que não tiveram a complicação, nas medidas realizadas 6 horas, 9 horas e 12 horas após a operação (P Abstract in english BACKGROUND: Monitoring of free flaps after surgery is vitally important, especially in the first few hours because the timing of reoperation can determine flap salvage or loss. To date, no study has examined the decision to reoperate on a flap based on the objective measure of glycemia or a comparis [...] on between flaps that showed good outcomes and those that showed vascular damage. The objective of this study was to evaluate the validity of blood glucose measurements within the flap as a method for monitoring free flaps and to compare the efficacy of this method with that of clinical assessments. METHODS: The study was prospective, included 16 patients with free flaps, and was conducted from May 2012 to July 2012. A team of professionals not involved in the surgery evaluated capillary glycemia. Flaps were clinically evaluated during the immediate postoperative period, on ICU admission, at every 3 hours, and as needed. RESULTS: Of the 16 patients, 5 (31.3%) had venous thrombosis in the first 24 hours. Statistically significant differences were noted in capillary glycemia in patients with or without venous thrombosis in measurements obtained 6, 9, and 12 hours after surgery (P

  9. Interaction of ZnS nanoparticles with flavins and glucose oxidase: A fluorimetric investigation

    International Nuclear Information System (INIS)

    Interactions of luminescence, water soluble ZnS nanoparticles (NPs) with flavins and glucose oxidase have been thoroughly investigated through optical spectroscopy. The photoluminescence of ZnS nanoparticles was quenched severely (?60%) by riboflavin while other flavins such as flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD) show quenching to different extents under analogous conditions. However, interestingly no effect in luminescence intensity of ZnS NPs was observed with protein bound flavins such as in glucose oxidase. Fluorescence lifetime measurement confirmed the quenching to be static in nature. Scavenging of photo-generated electron of ZnS nanoparticles by the flavin molecules may be attributed to the decrease in luminescence intensity. Quenching of ZnS nanoparticles with flavins follows the linear Stern–Volmer plot. The Stern–Volmer constants decreased in the following order: KS?V (Riboflavin)> KS?V (FAD)> KS?V (FMN). This interaction study could generate useful protocol for the fluorimetric determination of riboflavin (vitamin B2) content and also riboflavin status in biological systems. - Highlights: ? Unique interaction specificity of ZnS nanoparticles with flavins has been explored. ? Unlike protein-bound flavin, fluorescence of free flavins was quenched by ZnS nanoparticles. ? FMN and FAD show quenching to different extents under analogous conditions. ? Fluorescence lifeti ? Fluorescence lifetime measurement confirmed the quenching to be static in nature. ? This study is useful for probing riboflavin in biological systems.

  10. Classical analog of entanglement

    International Nuclear Information System (INIS)

    We show that quantum entanglement has a very close classical analog, namely, secret classical correlations. The fundamental analogy stems from the behavior of quantum entanglement under local operations and classical communication and the behavior of secret correlations under local operations and public communication. A large number of derived analogies follow. In particular, teleportation is analogous to the one time pad, the concept of 'pure state' exists in the classical domain, entanglement concentration and dilution are essentially classical secrecy protocols, and single-copy-entanglement manipulations have such a close classical analog that the majorization results are reproduced in the classical setting. This analogy allows one to import questions from the quantum domain into the classical one, and vice versa, helping to get a better understanding of both. Also, by identifying classical aspects of quantum entanglement, it allows one to identify those aspects of entanglement that are uniquely quantum mechanical

  11. Uptake and release of glucose by the human kidney. Postabsorptive rates and responses to epinephrine.

    OpenAIRE

    Stumvoll, M.; Chintalapudi, U.; Perriello, G.; Welle, S.; Gutierrez, O.; Gerich, J.

    1995-01-01

    Despite ample evidence that the kidney can both produce and use appreciable amounts of glucose, the human kidney is generally regarded as playing a minor role in glucose homeostasis. This view is based on measurements of arteriorenal vein glucose concentrations indicating little or no net release of glucose. However, inferences from net balance measurements do not take into consideration the simultaneous release and uptake of glucose by the kidney. Therefore, to assess the contribution of rel...

  12. Brain Glucose Metabolism Controls Hepatic Glucose and Lipid Production

    OpenAIRE

    Lam, Tony K.T.

    2007-01-01

    Brain glucose-sensing mechanisms are implicated in the regulation of feeding behavior and hypoglycemic-induced hormonal counter-regulation. This commentary discusses recent findings indicating that the brain senses glucose to regulate both hepatic glucose and lipid production.

  13. Analog circuit design

    CERN Document Server

    Dobkin, Bob

    2012-01-01

    Analog circuit and system design today is more essential than ever before. With the growth of digital systems, wireless communications, complex industrial and automotive systems, designers are being challenged to develop sophisticated analog solutions. This comprehensive source book of circuit design solutions aids engineers with elegant and practical design techniques that focus on common analog challenges. The book's in-depth application examples provide insight into circuit design and application solutions that you can apply in today's demanding designs. <

  14. Glucose monitoring during Ramadan.

    Science.gov (United States)

    Jabbar, Abdul

    2015-05-01

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

  15. Continuous glucose monitoring

    OpenAIRE

    Pandit, Kaushik

    2012-01-01

    Continuous glucose monitoring (CGM) technology with its recent development in the real-time feedback has got the potential to revolutionize diabetes care in the near future in the arena of the rapeutic interventions and flexibility in variations in lifestyle or dietary intake. CGM has made the attainment of near-normal blood glucose concentrations, a practical goal for most patients with diabetes.

  16. Radiopharmaceuticals. XXVII. 18F-labeled 2-deoxy-2-fluoro-D-glucose as a radiopharmaceutical for measuring regional myocardial glucose metabolism in vivo: tissue distribution and imaging studies in animals

    International Nuclear Information System (INIS)

    18F-2-Deoxy-2-fluoro-D-glucose (18FDG) is rapidly extracted by the mouse heart, and the radioactivity in heart (3 to 4% per organ) remains relatively constant for 2 hr post injection. The brain uptake (2 to 3% per organ) remained relatively constant throughout the time course of the study. Liver, lungs, kidneys, small intestine, and blood all showed a rapid clearance of radioactivity after injection of 18FDG. At 120 min the heart-to-lung ratio was 12 and heart-to-liver ratio was 32. Urinary excretion of activity was approximately 16% of the injected dose at 60 min. The uptake of radioactivity by dog heart following the intravenous administration of 18FDG was 2.8 to 4.1% at 60 min and 2.4% at 135 min; it was regionally distributed, the areas of highest activity being the left ventricle and the interventricular septum. The brain activity was 2.1 to 3.5% at 120 min, with a ratio of gray matter-to-white matter of 2 to 3:1. Urinary excretion in dogs was 16% and 50% of the injected dose at 60 and 135 min. The chemical form of the activity in the urine, although unidentified, was not 18F-. Cross-sectional images of the mycardium of the dog after intravenous injection of 18FDG were obtained using emission tomography

  17. Appetite sensations, appetite signaling proteins, and glucose in obese adolescents with subclinical binge eating disorder.

    Science.gov (United States)

    Adamo, Kristi B; Wilson, Shanna L; Ferraro, Zachary M; Hadjiyannakis, Stasia; Doucet, Eric; Goldfield, Gary S

    2014-01-01

    Objective. This study aimed to investigate potential differences in appetite sensations, ghrelin, peptide YY, and glucose and their relationship with energy and macronutrient intake in obese adolescents with subclinical binge eating disorder. Methods. Fifteen obese adolescents (six and nine individuals with and without subclinical binge eating disorder, resp.) qualified for this study. Visual analog scales and Three-Factor Eating Questionnaires were used to assess eating behaviours. Circulating ghrelin, peptide YY, and glucose were measured after fasting and at multiple time points postprandially following a standardized breakfast meal. Energy and macronutrient intake were measured with an ad libitum lunch buffet. Results. Emotional eating scores were significantly higher in obese adolescents with subclinical binge eating disorder. Hunger levels rose and satiety levels fell significantly over the course of the monitoring period but there was no difference between the two groups. Obese adolescents with subclinical binge eating disorder did not have significantly different levels of appetite signaling proteins or glucose. Obese adolescents with subclinical binge eating disorder had a nonsignificantly higher energy and macronutrient intake. Conclusions. A significant difference between the two groups in terms of their emotional eating scores highlights the important role that psychological factors play in relation to eating behaviours. PMID:25006530

  18. FASTING GLUCOSE AND INSULIN AND MEASURES OF INSULIN RESISTANCE OF MEN AFTER CONSUMPTION OF WHOLE WHEAT/BROWN RICE OR BARLEY.

    Science.gov (United States)

    Soluble fiber has been recognized as beneficial in decreasing blood glucose levels and other cardiovascular risk factors. Barley has high amounts of soluble fiber but has not been utilized extensively in the US diet. This study investigated whether consumption of barley would reduce cardiovascular r...

  19. Application of time gating in the measurement of glucose level in a three-layer biotissue model by using ultrashort laser pulses

    Science.gov (United States)

    Kirillin, M. Yu; Bykov, A. V.; Priezzhev, A. V.; Myllylä, R.

    2008-05-01

    The efficiency of using the time-of-flight (TOF) method at a wavelength of 820 nm for detecting the changes in the optical properties of multilayer light scattering medium in connection with the problem of the glucose level detection in the human tissue is discussed. Pulses scattered from a three-layer biotissue phantom consisting of two skin layers and a blood layer between them, are calculated with the help of a program code based on the Monte Carlo algorithm for different glucose concentrations. Relative changes in the recorded signals caused by variations in the glucose content are analysed for different source - detector separations. It is shown that the maximum relative change in the total pulse energy is 7.2% and 4.8% for the anisotropy factor of the layer mimicking skin g = 0.9 and 0.7, respectively, and the change in the glucose concentration from 0 up to 500 mg dL-1. The use of time gating leads to the increase in these values up to 12% and 8.5%, respectively. The sensitivity maps are obtained which can be used to determine the optimal duration and the time delay of the time gate relative to the probe pulse for five values of the source - detector separations.

  20. The immediate effects of a single bout of aerobic exercise on oral glucose tolerance across the glucose tolerance continuum

    DEFF Research Database (Denmark)

    Knudsen, Sine H; Karstoft, Kristian

    2014-01-01

    We investigated glucose tolerance and postprandial glucose fluxes immediately after a single bout of aerobic exercise in subjects representing the entire glucose tolerance continuum. Twenty-four men with normal glucose tolerance (NGT), impaired glucose tolerance (IGT), or type 2 diabetes (T2D; age: 56 ± 1 years; body mass index: 27.8 ± 0.7 kg/m(2), P > 0.05) underwent a 180-min oral glucose tolerance test (OGTT) combined with constant intravenous infusion of [6,6-(2)H2]glucose and ingestion of [U-(13)C]glucose, following 1 h of exercise (50% of peak aerobic power) or rest. In both trials, plasma glucose concentrations and kinetics, insulin, C-peptide, and glucagon were measured. Rates (mg kg(-1) min(-1)) of glucose appearance from endogenous (RaEndo) and exogenous (oral glucose; Ra OGTT) sources, and glucose disappearance (Rd) were determined. We found that exercise increased RaEndo, RaOGTT, and Rd (all P < 0.0001) in all groups with a tendency for a greater (~20%) peak RaOGTT value in NGT subjects when compared to IGT and T2D subjects. Accordingly, following exercise, the plasma glucose concentration during the OGTT was increased in NGT subjects (P < 0.05), while unchanged in subjects with IGT and T2D. In conclusion, while a single bout of moderate-intensity exercise increased the postprandial glucose response in NGT subjects, glucose tolerance following exercise was preserved in the two hyperglycemic groups. Thus, postprandial plasma glucose responses immediately following exercise are dependent on the underlying degree of glycemic control.

  1. Hydraulic Capacitor Analogy

    Science.gov (United States)

    Baser, Mustafa

    2007-01-01

    Students have difficulties in physics because of the abstract nature of concepts and principles. One of the effective methods for overcoming students' difficulties is the use of analogies to visualize abstract concepts to promote conceptual understanding. According to Iding, analogies are consistent with the tenets of constructivist learning…

  2. Changes in Glucose Homeostasis after Roux-en-Y Gastric Bypass Surgery for Obesity at Day Three, Two Months, and One Year after Surgery : Role of Gut Peptides

    DEFF Research Database (Denmark)

    Falkén, Y; Hellström, P M

    2011-01-01

    Context: Endocrine effects of gastric bypass (GBP) surgery for obesity on glucose homeostasis are not fully understood. Main Objective: The main objective of the study was to assess the changes in plasma glucose, insulin, glucagon-like peptide-1 (GLP-1), leptin, somatostatin, glucose-dependent insulinotropic peptide, enteroglucagon, and glucagon early after GBP. Method: Twelve obese subjects (body mass index 45.3 ± 1.9 kg/m2) were subjected to a liquid meal without lipids before and 3 d, 2 months, and 1 yr after GBP. Plasma concentrations of glucose, insulin, leptin, and gut peptide hormones were assessed before and for 180 min after the meal. Satiety was measured with visual analog scales. The absorption rate of acetaminophen added to the liquid meal was measured. Insulin resistance was measured by the homeostasis model assessment of insulin resistance. Results: All subjects lost weight (body mass index 30.3 ± 1.8 kg/m2 at 1 yr). Fasting glucose was significantly lower on d 3 (P < 0.05). There was a progressive decrease in the homeostasis model assessment of insulin resistance after 2 months postoperatively. Postprandially, there was a progressive rise of GLP-1 and enteroglucagon and a transient increase in pancreatic glucagon release over the study period. There was a leftward shift of the time course of plasma glucose and insulin. Somatostatin release was lower on d 3 (P < 0.05) but then unchanged. The absorption rate of acetaminophen was twice as fast after GBP compared with before surgery and did not change over time. Satiety scores increased markedly postoperatively. Conclusion: Both enhanced insulin sensitivity and incretin hormones, such as GLP-1, contribute to the early control of glucose homeostasis. Progressively increasing postprandial levels of enteroglucagon (oxyntomodulin) and GLP-1 facilitate weight loss and enhance insulin effectiveness.

  3. On the role of glucose-dependent insulintropic polypeptide in postprandial metabolism in humans

    DEFF Research Database (Denmark)

    Asmar, Meena; Tangaa, Winnie

    2010-01-01

    We investigated the role of glucose-dependent insulintropic polypeptide (GIP) in the regulation of gastric emptying (GE), appetite, energy intake (EI), energy expenditure (EE), plasma levels of triglycerides (TAG), and free fatty acids (FFA) in humans. First, 20 healthy males received intravenous infusion of GIP (0.8 pmol.kg(-1).min(-1)) or saline for 300 min during and after a fixed meal (protocol 1). GE was measured using paracetamol, appetite sensations using visual analog scales, EE using indirect calorimetry, and EI during a subsequent ad libitum meal (at 300 min). Next, 10 healthy males received intravenous infusions of Intralipid, glucose, or Intralipid plus glucose, with and without GIP (1.5 pmol.kg(-1).min(-1)) for 300 min (protocol 2). In protocol 1, GIP did not have any effect on GE, EI, EE, removal of TAG, or FFA and did not influence the subjective feeling of hunger, satiety, fullness or prospective food consumption compared with saline. In protocol 2, no difference was seen in the plasma TAG on Intralipid + GIP/saline and Intralipid + glucose + GIP/saline days. FFA concentrations were lower on Intralipid + glucose + GIP/saline days (P <0.05) compared with Intralipid + GIP/saline days and on Intralipid + GIP day (P <0.004) compared with Intralipid + saline day. Insulin increased on all GIP days compared with saline days (P <0.05). In conclusion, while confirming its insulinotropic effects, these data suggest that GIP does not affect GE, appetite, energy intake, EE, or the clearance rate of the applied TAG formulation in humans. However, both insulin and GIP lower post-Intralipid FFA concentration, GIP probably via stimulation of insulin secretion, increasing FFA reesterification.

  4. Analog vs. Digital

    Science.gov (United States)

    Mrs. Allen, STS

    2007-10-09

    As you all know, the reading of analog clocks is fast becoming old-fashioned and out of date. I remember a young junior high schooler tell the principal one time, \\"I can\\'t read that kind of clock! I don\\'t know what time it is.\\" Let\\'s not end up like her. Try to practice your skills telling time with analog clocks. Move the hands of the clock to show the correct time. Time Clock See if you can match the analog time with the digital time. Match Analog and Digital When you get to this page, click the random button and then practice telling the analog time. If level one is too easy, then try levels ...

  5. Discrete LIBOR Market Model Analogy

    CERN Document Server

    Hula, Andreas

    2011-01-01

    This paper provides a discrete time LIBOR analog, which can be used for arbitrage-free discretization of Levy LIBOR models or discrete approximation of continuous time LIBOR market models. Using the work of Eberlein and Oezkan as an inspiration, we build a discrete forward LIBOR market model by starting with a discrete exponential martingale. We take this pure jump process and calculate the appropriate measure change between the forward measures. Next we prove weak convergence of the discrete analog to the continuous time LIBOR model, provided the driving process converges weakly to the continuous time one and the driving processes are PII's. This especially implies the weak convergence of the model to a Levy LIBOR market model if the driving process variables are infinitely divisible distributions. This also relates our model to an Euler discretization.

  6. Kidney transplantation improves arterial function measured by pulse wave analysis and endothelium-independent dilatation in uraemic patients despite deterioration of glucose metabolism

    DEFF Research Database (Denmark)

    Hornum, Mads; Clausen, Peter

    2011-01-01

    BACKGROUND: The aim of this study is to investigate the effect of kidney transplantation on arterial function in relation to changes in glucose metabolism. METHODS: Included were 40 kidney recipients (Tx group, age 38 ± 13 years) and 40 patients without known diabetes remaining on the waiting list for kidney transplantation (uraemic control group, age 47 ± 11 years). Arterial function was estimated by the pulse wave velocity (PWV) of the carotid-femoral pulse wave, aortic augmentation index (AIX), flow-mediated (FMD) and nitroglycerin-induced vasodilatation (NID) of the brachial artery performed before transplantation and after 12 months. PWV recorded sequentially at the carotid and femoral artery is an estimate of arterial stiffness; AIX is an integrated index of vascular and ventricular function. FMD and NID are the dilatory capacities of the brachial artery after increased flow (endothelium dependent) and after nitroglycerin administration (endothelium independent). The insulin resistance was estimated by the insulin sensitivity index (ISI). RESULTS: AIX was reduced from 27% (17-33) to 14% (7-25) (P = 0.01) after 1 year in the Tx group and remained stable in uraemic controls (P = 0.001, between groups), and NID increased from 11% (7-16) to 18% (12-23) (P = 0.0005). At baseline, carotid-femoral PWV was similar in the Tx group, uraemic controls and healthy controls and it did not change significantly after transplantation. ISI deteriorated in the Tx group from 7.2 ± 4.0 to 5.0 ± 3.0 (P = 0.005) and remained stable in uraemic controls (7.9 ± 5.1 vs 8.5 ± 4.9, NS). Mean arterial blood pressure decreased from 105 ± 13 to 96 ± 11 mmHg (P = 0.005) in the Tx group despite a 20% lower use of antihypertensive agents. CONCLUSIONS: Arterial function measured by AIX and NID was improved 1 year after kidney transplantation. This was associated with a decline in blood pressure and seen inspite of an increase in insulin resistance.

  7. Evolution of insulin: from human to analog.

    Science.gov (United States)

    Tibaldi, Joseph M

    2014-10-01

    The development of insulin analogs has made improved treatment of type 2 diabetes possible. In this article, structural alterations, pharmacokinetics and pharmacodynamics, clinical end points, and safety issues are reviewed for the currently available basal insulins, rapid-acting insulins, and premixes. The flatter activity profiles of insulin glargine and insulin detemir translate into good clinical efficacy with a lower risk of hypoglycemia relative to neutral protamine Hagedorn insulin. Weight gain is consistently lower with insulin detemir than with neutral protamine Hagedorn insulin. Insulin degludec, licensed in Europe and Japan but not yet in the United States, has a mean half-life of 25.4 hours, a duration of action of >42 hours, and low variability. In trials in type 2 diabetes, rates of nocturnal hypoglycemia were lower with insulin degludec than with insulin glargine, and more flexible; once-daily dose timing was shown to be possible. Insulin lispro, insulin aspart, and insulin glulisine are rapidly absorbed after injection and thus provide better coverage of the post-prandial glucose surge compared with human insulin. Trials and meta-analyses show that reductions in glycated hemoglobin are similar and control of postprandial glucose is better with the rapid-acting analogs versus human insulin. Convenience is greater for patients because the analogs can be injected just before a meal. In premix or biphasic insulins, a proportion of the rapid-acting analog is protaminated, providing both rapid-acting and intermediate-acting components in one formulation, thus reducing the number of injections required. Alterations to human insulin have resulted in improvements in safety, efficacy, tolerability, and convenience for patients. PMID:25282010

  8. Analogical Dissimilarity: Definition, Algorithms and Two Experiments in Machine Learning

    OpenAIRE

    Miclet, Laurent; Bayoudh, Sabri; Delhay, Arnaud

    2014-01-01

    This paper defines the notion of analogical dissimilarity between four objects, with a special focus on objects structured as sequences. Firstly, it studies the case where the four objects have a null analogical dissimilarity, i.e. are in analogical proportion. Secondly, when one of these objects is unknown, it gives algorithms to compute it. Thirdly, it tackles the problem of defining analogical dissimilarity, which is a measure of how far four objects are from being in ana...

  9. Specificity of noninvasive blood glucose monitoring with optical coherence tomography

    Science.gov (United States)

    Larin, Kirill V.; Ashitkov, Taras V.; Motamedi, Massoud; Esenaliev, Rinat O.

    2003-07-01

    Management of diabetic disease requires frequent monitoring of blood glucose concentration. Development of a noninvasive technique capable of reliable and sensitive monitoring of blood glucose concentration would considerably improve quality of life of diabetic patients and reduce mortality associated with this disease. Recently, we proposed to use Optical Coherence Tomography (OCT) technique for noninvasive glucose monitoring. In this paper, we tested in animals several aspects of specificity of noninvasive blood glucose monitoring with the OCT technique. Influence of temperature and tissue heterogeneity on the OCT signal profile is experimentally studied in this paper. We also theoretically investigated the changes in tissue scattering induced by variation of concentration of glucose and other osmolytes. Obtained results suggest that although several physical and chemical agents could potentially interfere with blood glucose concentration measurements using the OCT technique, their effect is smaller compared to that of glucose under normal physiological conditions.

  10. Use of glycosylated dendrimer macromolecules to fluorescently monitor glucose concentration

    Science.gov (United States)

    Beier, Hope T.; Ibey, Bennett L.; Pishko, Michael V.; Coté, Gerard L.

    2007-02-01

    A minimally invasive biosensor is undergoing development to detect physiological concentrations of glucose within interstitial fluid. The sensor is based on a chemical assay consisting of Alexa Fluor 647 labeled concanavalin A lectin and dendrimer macromolecules functionalized to contain peripheral glucose moieties. The two components form large cross-linked particles that result in loss of fluorescent emission through shielding of interior fluorophores. As glucose is introduced into the assay, it competes with the glycodendrimers for binding to concanavalin A to disrupt the cross-linked complex and produce a reversible change in fluorescence intensity that is dependent on glucose concentration. Chemical analogs of the original glycodendrimer have been created and analyzed with the purpose of creating more stable and consistent dendrimers in order to maximize the response of the assay so that its signal can be better detected through dermal tissue and provide a better understanding of the sensor binding mechanics.

  11. Mechanism for underestimation of isotopically determined glucose disposal

    International Nuclear Information System (INIS)

    Use of [3H]glucose and a one-compartment model to determine glucose kinetics frequently underestimates the rate of glucose production (Ra). To assess to what extent an isotope effect, a tracer contaminant, or inadequacy of the model was responsible, we measured glucose Ra and forearm clearance of tracer and unlabeled glucose at various concentrations of plasma insulin (approximately 50, approximately 160, and approximately 1800 microU/ml) and plasma glucose (approximately 90, approximately 160, approximately 250, and approximately 400 mg/dl) under steady-state and non-steady-state conditions. Under isotopic steady-state conditions, the clearances of tracer and unlabeled glucose across the forearm were identical, and exogenous glucose infusion rates did not differ significantly from the isotopically determined glucose Ra (10.0 +/- 1.3 vs. 10.5 +/- 1.0 mg.kg-1 fat-free mass.min-1, respectively). However, under isotopic non-steady-state conditions, the isotopically determined Ra was significantly lower than the glucose infusion rate (11.5 +/- 1.3 vs. 13.7 +/- 1.5 mg.kg-1 fat-free mass.min-1, respectively, P less than .001), and the underestimation was related to the deviation from the isotopic steady state. When [3H]glucose specific activity of plasma samples from experiments with the greatest underestimation of Ra was determined by high-performance liquid chromatography, less than 7% of the underestimation could be accounted for by a contaminant. These results indicate by a contaminant. These results indicate that inadequacy of the one-compartment model is responsible for underestimation of glucose Ra under non-steady-state conditions and that there is no detectable isotopic effect or appreciable contaminant of [3-3H]glucose. We conclude that under isotopic steady-state conditions, [3-3H]glucose is a reliable tracer for glucose kinetic studies in humans

  12. The Impact of Melatonin on Glucose Homeostasis

    Directory of Open Access Journals (Sweden)

    Zeynep Arzu Ye?in

    2009-12-01

    Full Text Available Objective: Melatonin is a pineal product mainly charged with the maintenance of antioxidant conditions in human. This study is performed to identify the short-term effect of melatonin on glucose homeostasis in diabetic patients. Materials and Methods: Melatonin and placebo were given perorally to sixty patients. Blood glucose and insulin levels were measured with constant intervals. Results: No significant correlation was found among the levels of glucose, insulin and HOMA-IR index at any time after melatonin/placebo administration.Conclusions: Prospective studies with long-term use of melatonin are needed to define the exact role of melatonin in glucose homeostasis. Turk Jem 2009; 13: 52-5

  13. Meat analog: a review.

    Science.gov (United States)

    Malav, O P; Talukder, S; Gokulakrishnan, P; Chand, S

    2015-01-01

    The health-conscious consumers are in search of nutritious and convenient food item which can be best suited in their busy life. The vegetarianism is the key for the search of such food which resembles the meat in respect of nutrition and sensory characters, but not of animal origin and contains vegetable or its modified form, this is the point when meat analog evolved out and gets shape. The consumers gets full satisfaction by consumption of meat analog due to its typical meaty texture, appearance and the flavor which are being imparted during the skilled production of meat analog. The supplement of protein in vegetarian diet through meat alike food can be fulfilled by incorporating protein-rich vegetative food grade materials in meat analog and by adopting proper technological process which can promote the proper fabrication of meat analog with acceptable meat like texture, appearance, flavor, etc. The easily available vegetables, cereals, and pulses in India have great advantages and prospects to be used in food products and it can improve the nutritional and functional characters of the food items. The various form and functional characters of food items are available world over and attracts the meat technologists and the food processors to bring some innovativeness in meat analog and its presentation and marketability so that the acceptability of meat analog can be overgrown by the consumers. PMID:24915320

  14. Predicting Plasma Glucose From Interstitial Glucose Observations Using Bayesian Methods

    DEFF Research Database (Denmark)

    Hansen, Alexander Hildenbrand; Duun-Henriksen, Anne Katrine

    2014-01-01

    One way of constructing a control algorithm for an artificial pancreas is to identify a model capable of predicting plasma glucose (PG) from interstitial glucose (IG) observations. Stochastic differential equations (SDEs) make it possible to account both for the unknown influence of the continuous glucose monitor (CGM) and for unknown physiological influences. Combined with prior knowledge about the measurement devices, this approach can be used to obtain a robust predictive model. A stochastic-differential-equation-based gray box (SDE-GB) model is formulated on the basis of an identifiable physiological model of the glucoregulatory system for type 1 diabetes mellitus (T1DM) patients. A Bayesian method is used to estimate robust parameters from clinical data. The models are then used to predict PG from IG observations from 2 separate study occasions on the same patient. First, all statistically significant diffusion terms of the model are identified using likelihood ratio tests, yielding inclusion of ?Isc, ?Gp, and ?Gsc . Second, estimates using maximum likelihood are obtained, but prediction capability is poor. Finally a Bayesian method is implemented. Using this method the identified models are able to predict PG using only IG observations. These predictions are assessed visually. We are also able to validate these estimates on a separate data set from the same patient. This study shows that SDE-GBs and a Bayesian method can be used to identify a reliable model for prediction of PG using IG observations obtained with a CGM. The model could eventually be used in an artificial pancreas.

  15. Continuous glucose monitoring system: Is it really accurate, safe and clinically useful?

    OpenAIRE

    Sato, Junko; Hirose, Takahisa; Watada, Hirotaka

    2012-01-01

    The continuous glucose monitoring system (CGM) has been used for constant checking of glucose level by measuring interstitial glucose concentrations, since the early days of the 21st century. It can potentially improve diabetes care if used carefully with the understanding of the characteristics of this system. Although there is a time lag of approximately 5–15?min between blood and interstitial glucose levels, the system is considered the most suitable device for meticulous glucose contr...

  16. Detecting early kidney damage in horses with colic by measuring matrix metalloproteinase -9 and -2, other enzymes, urinary glucose and total proteins

    OpenAIRE

    Salonen Hanna; Kastevaara Tuulia; Holopainen Elina; Rajamäki Minna; Raekallio Marja; Arosalo Bela M; Sankari Satu

    2007-01-01

    Abstract Background The aim of the study was to investigate urine matrix metalloproteinase (MMP-2 and -9) activity, alkaline phosphatase/creatinine (U-AP/Cr) and gamma-glutamyl-transpeptidase/creatinine (U-GGT/Cr) ratios, glucose concentration, and urine protein/creatinine (U-Prot/Cr) ratio and to compare data with plasma MMP-2 and -9 activity, cystatin-C and creatinine concentrations in colic horses and healthy controls. Horses with surgical colic (n = 5) were compared to healthy stallions (...

  17. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Complications Neuropathy Foot Complications DKA (Ketoacidosis) & Ketones Kidney Disease (Nephropathy) Gastroparesis Mental Health Treatment & Care Blood Glucose Testing Medication Doctors, Nurses & More Oral Health & Hygiene Women ...

  18. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... Support Legal Assistance Success Stories Complications Hypoglycemia Hyperglycemia Skin Complications Eye Complications Neuropathy Foot Complications DKA (Ketoacidosis) & Ketones Kidney Disease (Nephropathy) Gastroparesis Mental Health Treatment & Care Blood Glucose ...

  19. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... In Memory In Honor Become a Member En Español Type 1 Type 2 About Us Online Community ... Page Text Size: A A A Listen En Español Hyperglycemia (High Blood Glucose) Hyperglycemia is the technical ...

  20. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... A A A Listen En Español Hyperglycemia (High Blood Glucose) Hyperglycemia is the technical term for high ... Your best bet is to practice good diabetes management and learn to detect hyperglycemia so you can ...

  1. Fructose, Glucose and Hunger

    Medline Plus

    Full Text Available ... effects of fructose and glucose on hunger and food responses in the brain. 24 healthy people were ... participants rated their hunger level and motivation for food on a scale of 1 to 10. They ...

  2. Hyperglycemia (High Blood Glucose)

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    Full Text Available ... Non-starchy Vegetables Grains and Starchy Vegetables Fats Alcohol What Can I Drink? Fruit Dairy Food Tips ... may make your blood glucose level go even higher. You'll need to work with your doctor ...

  3. Hyperglycemia (High Blood Glucose)

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    Full Text Available ... Complications DKA (Ketoacidosis) & Ketones Kidney Disease (Nephropathy) Gastroparesis Mental Health Treatment & Care Blood Glucose Testing Medication Doctors, Nurses & More Oral Health & Hygiene Women A1C ...

  4. Hyperglycemia (High Blood Glucose)

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    Full Text Available ... Ketones Kidney Disease (Nephropathy) Gastroparesis Mental Health Treatment & Care Blood Glucose Testing Medication Doctors, Nurses & More Oral ... 2 Diabetes Know Your Rights Employment Discrimination Health Care Professionals Law Enforcement Driver's License For Lawyers Food & ...

  5. Fructose, Glucose and Hunger

    Medline Plus

    Full Text Available ... glucose on hunger and food responses in the brain. 24 healthy people were asked to drink a ... scale of 1 to 10. They also underwent brain scans while they were shown images of high- ...

  6. Blood Glucose Monitoring Devices

    Science.gov (United States)

    ... and Human Services FDA U.S. Food and Drug Administration Protecting and Promoting Your Health A to Z ... Glucose NIH Medline Plus - Diabetes Spotlight FDA permits marketing of first system of mobile medical apps for ...

  7. Hyperglycemia (High Blood Glucose)

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    Full Text Available ... a.m. to 5:00 a.m.). What are the Symptoms of Hyperglycemia? The signs and symptoms ... have ketones, do not exercise. Exercising when ketones are present may make your blood glucose level go ...

  8. Hyperglycemia (High Blood Glucose)

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    Full Text Available ... and Pacific Islanders American Indian/Alaska Native Programs Older Adults Stop Diabetes at Work Family Link Diabetes EXPO ... Events Close www.diabetes.org > Living With Diabetes > Treatment and Care > Blood Glucose Testing atf en -- 2015 ...

  9. Hyperglycemia (High Blood Glucose)

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    Full Text Available ... Eye Complications Neuropathy Foot Complications DKA (Ketoacidosis) & Ketones Kidney Disease (Nephropathy) Gastroparesis Mental Health Treatment & Care Blood Glucose Testing Medication Doctors, Nurses & More Oral Health & Hygiene ...

  10. All about Blood Glucose

    Science.gov (United States)

    What are the blood glucose targets for people with diabetes? TargetssetbytheAmerican DiabetesAssociation (ADA)arelistedbelow. Talkwithyourhealthcareteam aboutyour personalgoals. What’s the best way to keep track of ...

  11. Hyperglycemia (High Blood Glucose)

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    Full Text Available ... Care Blood Glucose Testing Medication Doctors, Nurses & More Oral Health & Hygiene Women A1C Insulin Pregnancy 8 Tips ... that smells fruity Nausea and vomiting Very dry mouth Talk to your doctor about how to handle ...

  12. Hyperglycemia (High Blood Glucose)

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    Full Text Available ... for Association Events Messaging Tools Recruiting Advocates Local Market Planning Training Webinars News & Events Advocacy News Call ... glucose happens when the body has too little insulin or when the body can't use insulin ...

  13. Hyperglycemia (High Blood Glucose)

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    Full Text Available ... insulin, your body can't use glucose for fuel, so your body breaks down fats to use ... Advocacy Take Action Advocacy Priorities News & Events The Cost of Diabetes Advocate Toolkit Call to Congress Research & ...

  14. Glucose Monitoring During Pregnancy

    OpenAIRE

    HAWKINS, J. SETH

    2010-01-01

    Self-monitoring of blood glucose in women with mild gestational diabetes has recently been proven to be useful in reducing the rates of fetal overgrowth and gestational weight gain. However, uncertainty remains with respect to the optimal frequency and timing of self-monitoring. A continuous glucose monitoring system may have utility in pregnant women with insulin-treated diabetes, especially for those women with blood sugars that are difficult to control or who experience nocturnal hypoglyce...

  15. Reliability, Responsiveness, and Validity of the Visual Analog Fatigue Scale to Measure Exertion Fatigue in People with Chronic Stroke: A Preliminary Study

    OpenAIRE

    Kluding, Patricia M; Gajewski, Byron J; Tseng, Benjamin Y.

    2010-01-01

    Background and Purpose. Post-Stroke Fatigue (PSF) is a prevalent yet commonly neglected issue that impacts daily functions and quality of life in people post-stroke. To date no studies have attempted to validate a clinically-feasible and reliable instrument to quantify PSF. We developed the Visual Analog Fatigue Scale (VAFS) to eliminate difficulties and poor data validity in testing people post-stroke. The purpose of this study was to evaluate the reliability, responsiveness, and validity ...

  16. Tear glucose analysis for the noninvasive detection and monitoring of diabetes mellitus.

    Science.gov (United States)

    Baca, Justin T; Finegold, David N; Asher, Sanford A

    2007-10-01

    One approach to the noninvasive monitoring of blood glucose concentration is to monitor glucose concentrations in tear fluid. While several methods for sensing glucose in tear fluid have been proposed, controversy remains as to the precise concentrations of tear glucose in normal and diabetic subjects and as to whether tear fluid glucose concentrations correlate with blood glucose concentrations. This review covers the present understanding of the physiology of glucose transport in tears, the regulation of the aqueous tear fraction, and studies of tear glucose concentration over the last 80 years. The various tear collection methods employed greatly influence the measured tear glucose concentrations. Studies that involve mechanical irritation of the conjunctiva during sampling measure the highest tear glucose concentrations, while studies that avoid tear stimulation measure the lowest concentrations. Attempts to monitor tear glucose concentration in situ by using contact lens-based sensing devices are discussed, and new observations are presented of tear glucose concentration obtained by a method designed to avoid tear stimulation. These studies indicate the importance of the sampling method in determining tear glucose concentrations. On the basis of these results, we discuss the future of in vivo tear glucose sensing and outline the studies needed to resolve the remaining questions about the relationship between tear and blood glucose concentrations. PMID:17938838

  17. Some Thomists on Analogy.

    Czech Academy of Sciences Publication Activity Database

    Dvo?ák, Petr

    2006-01-01

    Ro?. 3, ?. 1 (2006), s. 28-35. ISSN 1214-8407 Institutional research plan: CEZ:AV0Z90090514 Keywords : doctrine of analogy * Thomas Aquinas * Thomism * semantics Subject RIV: AA - Philosophy ; Religion

  18. Challenges in Using Analogies

    Science.gov (United States)

    Lin, Shih-Yin; Singh, Chandralekha

    2011-11-01

    Learning physics requires understanding the applicability of fundamental principles in a variety of contexts that share deep features.1-7 One way to help students learn physics is via analogical reasoning. Students can be taught to make an analogy between situations that are more familiar or easier to understand and another situation where the same physics principle is involved but that is more difficult to handle. Here, we examine introductory physics students' ability to use analogies in solving problems involving Newton's second law. Students enrolled in an algebra-based introductory physics course were given a solved problem involving tension in a rope and were then asked to solve another problem for which the physics is very similar but involved a frictional force. They were asked to point out the similarities between the two problems and then use the analogy to solve the friction problem.

  19. Analogies in theoretical physics

    OpenAIRE

    Jona-lasinio, Giovanni

    2010-01-01

    Analogies have had and continue to have an important role in the development of theoretical physics. They may start from similarities of physical concepts followed by similarities in the mathematical formalization or it may be a purely mathematical aspect to suggest the development of analogous physical concepts. More often a subtle non obvious interplay between these levels is involved. In this paper I will discuss two cases sufficiently intricate to illustrate some ways of...

  20. FGF growth factor analogs

    Energy Technology Data Exchange (ETDEWEB)

    Zamora, Paul O. (Gaithersburg, MD); Pena, Louis A. (Poquott, NY); Lin, Xinhua (Plainview, NY); Takahashi, Kazuyuki (Germantown, MD)

    2012-07-24

    The present invention provides a fibroblast growth factor heparin-binding analog of the formula: ##STR00001## where R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, X, Y and Z are as defined, pharmaceutical compositions, coating compositions and medical devices including the fibroblast growth factor heparin-binding analog of the foregoing formula, and methods and uses thereof.

  1. Glucose Counterregulatory Responses to Hypoglycemia

    OpenAIRE

    Sprague, Jennifer E.; Arbeláez, Ana María

    2011-01-01

    The brain relies almost exclusively on glucose for fuel. Therefore, adequate uptake of glucose from the plasma is key for normal brain function and survival. Despite wide variations in glucose flux (i.e. fed state, fasting state, etc), blood glucose is maintained in a very narrow range. This is accomplished by a series of hormonal and physiologic responses. As a result, hypoglycemia is a rare occurrence in normal individuals. However, glucose counterregulatory responses are altered in patient...

  2. Renal processing of glucose in well and sick neonates

    OpenAIRE

    COULTHARD, M; HEY, E

    1999-01-01

    AIMS—To determine the extent of renal processing of glucose in sick and well neonates.?METHODS—Glomerular filtration rate (GFR) and the renal processing of glucose, sodium, and water were measured using prolonged inulin infusion in 47 infants of 26-40 weeks of gestation, aged 1-13 days.?RESULTS—GFR rose by 15% after ventilatory support was withdrawn, and was unaffected by clinical instability. Fractional glucose excretion was low in the stable unventilated babies except a...

  3. Integrating optical glucose sensing into a planar waveguide sensor structure

    Science.gov (United States)

    Dutta, Aradhana; Deka, Bidyut; Sahu, Partha P.

    2013-06-01

    A device for glucose monitoring in people with diabetes is a clinical and research priority in the recent years for its accurate self management. An extensive theoretical design and development of an optical sensor is carried out incorporating planar waveguide structure in an endeavor to measure slight changes of glucose concentration. The sensor is simple and highly sensitive and has the potential to be used for online monitoring of blood glucose levels for the diabetic patients in the near future.

  4. Abnormal temporal lobe response in Alzheimer's disease during cognitive processing as measured by 11C-2-deoxy-D-glucose and PET

    International Nuclear Information System (INIS)

    Elderly controls and probable Alzheimer's disease patients underwent serial positron emission tomography (PET) studies during a baseline condition and while performing a verbal memory task. For the temporal lobes, all 7 Alzheimer patients demonstrated a relative shift in glucose metabolic rates to the right hemisphere during the memory condition relative to baseline, and 5 of 7 controls showed a shift to the left hemisphere. Baseline absolute regional metabolic rates replicate previous findings and were somewhat less useful than the memory challenge in differentiating patients from controls. These results indicate that a temporal lobe abnormality in Alzheimer's disease is related to memory performance

  5. Effect of growth conditions on the Streptococcus bovis phosphoenolpyruvate glucose phosphotransferase system.

    Science.gov (United States)

    Moore, G A; Martin, S A

    1991-12-01

    Four strains of the ruminal bacterium Streptococcus bovis were surveyed for phosphoenolpyruvate (PEP) and ATP-dependent phosphorylation of glucose and the nonmetabolizable glucose analog 2-deoxyglucose. All four strains had high rates of glucose phosphorylation with either phosphoryl donor, but 2-deoxyglucose activity was much higher in the presence of PEP. These results provide evidence for a PEP-dependent glucose phosphotransferase system in these bacteria. Mannose and 2-deoxyglucose inhibited PEP-dependent phosphorylation of glucose by S. bovis JB1 by 50 and 38%, respectively, whereas alpha-methylglucoside had little effect. Mannose was a competitive inhibitor of PEP-dependent phosphorylation of glucose with an inhibition constant of 2.8 mM, and PEP-dependent activity in cells grown in batch culture was optimal at pH 7.2. When S. bovis JB1 was grown in continuous culture, PEP-dependent phosphorylation of glucose and 2-deoxyglucose was highest in cells grown at a dilution rate of .10/h and at low glucose concentrations. Phosphoenolpyruvate-dependent activity was optimum at a growth pH of 5.0 for cells grown in medium that contained less than 6.0 g/liter of glucose. These data indicate that PEP-dependent glucose phosphotransferase system activity can be influenced depending on the growth conditions used to culture S. bovis. Furthermore, these results suggest that environmental conditions within the rumen will affect how glucose is transported by S. bovis. PMID:1808190

  6. Effects of MDMA on blood glucose levels and brain glucose metabolism

    Energy Technology Data Exchange (ETDEWEB)

    Soto-Montenegro, M.L.; Vaquero, J.J.; Garcia-Barreno, P.; Desco, M. [Hospital General Universitario Gregorio Maranon, Laboratorio de Imagen, Medicina Experimental, Madrid (Spain); Arango, C. [Hospital General Gregorio Maranon, Departamento de Psiquiatria, Madrid (Spain); Ricaurte, G. [Johns Hopkins University School of Medicine, Department of Neurology, Baltimore, MD (United States)

    2007-06-15

    This study was designed to assess changes in glucose metabolism in rats administered single or repeated doses of MDMA. Two different experiments were performed: (1) A single-dose study with four groups receiving 20 mg/kg, 40 mg/kg, saline or heat, and (2) a repeated-dose study with two groups receiving three doses, at intervals of 2 h, of 5 mg/kg or saline. Rats were imaged using a dedicated small-animal PET scanner 1 h after single-dose administration or 7 days after repeated doses. Glucose metabolism was measured in 12 cerebral regions of interest. Rectal temperature and blood glucose were monitored. Peak body temperature was reached 1 h after MDMA administration. Blood glucose levels decreased significantly after MDMA administration. In the single-dose experiment, brain glucose metabolism showed hyperactivation in cerebellum and hypo-activation in the hippocampus, amygdala and auditory cortex. In the repeated-dose experiment, brain glucose metabolism did not show any significant change at day 7. These results are the first to indicate that MDMA has the potential to produce significant hypoglycaemia. In addition, they show that MDMA alters glucose metabolism in components of the motor, limbic and somatosensory systems acutely but not on a long-term basis. (orig.)

  7. Effects of MDMA on blood glucose levels and brain glucose metabolism

    International Nuclear Information System (INIS)

    This study was designed to assess changes in glucose metabolism in rats administered single or repeated doses of MDMA. Two different experiments were performed: (1) A single-dose study with four groups receiving 20 mg/kg, 40 mg/kg, saline or heat, and (2) a repeated-dose study with two groups receiving three doses, at intervals of 2 h, of 5 mg/kg or saline. Rats were imaged using a dedicated small-animal PET scanner 1 h after single-dose administration or 7 days after repeated doses. Glucose metabolism was measured in 12 cerebral regions of interest. Rectal temperature and blood glucose were monitored. Peak body temperature was reached 1 h after MDMA administration. Blood glucose levels decreased significantly after MDMA administration. In the single-dose experiment, brain glucose metabolism showed hyperactivation in cerebellum and hypo-activation in the hippocampus, amygdala and auditory cortex. In the repeated-dose experiment, brain glucose metabolism did not show any significant change at day 7. These results are the first to indicate that MDMA has the potential to produce significant hypoglycaemia. In addition, they show that MDMA alters glucose metabolism in components of the motor, limbic and somatosensory systems acutely but not on a long-term basis. (orig.)

  8. Glucose biosensor based on glucose oxidase immobilized on unhybridized titanium dioxide nanotube arrays

    International Nuclear Information System (INIS)

    A glucose biosensor has been fabricated by immobilizing glucose oxidase (GOx) on unhybridized titanium dioxide nanotube arrays using an optimized cross-linking technique. The TiO2 nanotube arrays were synthesized directly on a titanium substrate by anodic oxidation. The structure and morphology of electrode material were characterized by X-ray diffraction and scanning electron microscopy. The electrochemical performances of the glucose biosensor were conducted by cyclic voltammetry and chronoamperometry measurements. It gives a linear response to glucose in the 0.05 to 0.65 mM concentration range, with a correlation coefficient of 0.9981, a sensitivity of 199.6 ?A mM?1 cm?2, and a detection limit as low as 3.8 µM. This glucose biosensor exhibited high selectivity for glucose determination in the presence of ascorbic acid, sucrose and other common interfering substances. This glucose biosensor also performed good reproducibility and long-time storage stability. This optimized cross-linking technique could open a new avenue for other enzyme biosensors fabrication. (author)

  9. Fundamental study on non-invasive blood glucose sensing.

    Science.gov (United States)

    Xu, K; Li, Q; Lu, Z; Jiang, J

    2002-01-01

    Diabetes is a disease which severely threatens the health of human beings. Unfortunately, current monitoring techniques with finger sticks discourage the regular use. Noninvasive spectroscopic measurement of blood glucose is a simple and painless technique, and reduces the long-term health care costs of diabetic patients due to no reagents. It is suitable for home use. Moreover, the establishment of the methodology not only applies to blood glucose noninvasive measurement, but also can be extended to noninvasive measurement of other analytes in body fluid, which will be of important significance for the development of the technique of clinical analysis. In this paper, some fundamental researches, which have been achieved in our laboratory in the field of non-invasive blood glucose measurement, were introduced. 1. Fundamental research was done for the glucose concentrations from simple to complex samples with near and middle infrared spectroscopy: (1) the relationship between the instrument precision and prediction accuracy of the glucose measurement; (2) the change of the result of the quantitative measurement with the change of the complexity of samples; (3) the attempt of increasing the prediction accuracy of the glucose measurement by improving the methods of modeling. The research results showed that it is feasible for non-invasive blood glucose measurement with near and middle infrared spectroscopy in theory, and the experimental results, from simple to complex samples, proved that it is effective for the methodology consisting of hardware and software. 2. According to the characteristics of human body measurement, the effects of measuring conditions on measurement results, such as: (1) the effect of measurement position; (2) the effect of measurement pressure; (3) the effect of measurement site; (4) the effect of measured individual, were investigated. With the fundamental researches, the special problems of human body measurement were solved. In addition, the practical and effective method of noninvasive human blood glucose measurement was proposed. PMID:22388048

  10. The Effect of Basal Analog Insulin on the Glycemic Variability in Type 2 Diabetics

    Directory of Open Access Journals (Sweden)

    Soner Cander

    2014-06-01

    Full Text Available Purpose: The aim of this study was to investigate the effect of insulin detemir and glargine on glycemic variability as determined by capillary blood glucose measurements in Type 2 diabetics treated with oral antidiabetic drugs. Material and Method: A total of 64 insulin-naive type 2 diabetics with a HbA1c level of 7.5%-10% were included in the study. The patients were randomized into 3 groups according to the basal insulin analog started; Group 1 (n=22 was started on once-daily detemir, Group 2 (n=22 twice-daily detemir, and Group 3 (n=20 insulin glargine. Basal insulin doses were titrated according to the morning/evening fasting capillary blood glucose levels. Standard deviations of the 8-point intraday fasting and postprandial blood glucose values were compared. Results: The fasting blood glucose intraday standard deviation values showed an improvement of 22.4% in Group 1, 21.4% in Group 2, and 26.4% in Group 3, while the intraday standard deviation for the postprandial values showed an improvement of 14.4%, 15.2%, and 38.7%, respectively (p>0.05. The standard deviation values did not show statistical significance when the groups were compared with each other. Baseline HbA1c values and insulin doses negatively correlated with the glycemic variability. Dicussion: Basal insulin added to treatment in Type 2 diabetics provided an improvement of 14.4% to 38.7% in glycemic variability. There was no significant difference between insulin glargine and detemir regarding this effect. Turk Jem 2014; 2: 33-38

  11. Interaction of Glucose with ZnO Nanoparticles

    Directory of Open Access Journals (Sweden)

    P.K. Samanta

    2014-06-01

    Full Text Available We report the results of the extent of interaction as well as the formation of a bioconjugate of glucose with Zinc Oxide nano particles (ZnO NPs to understand the non-invasive monitoring of glucose by semiconductor NPs. We performed an array of photophysical as well as microscopic measurements to quantify the interaction between ZnO NPs and glucose. We have found that time constant of interaction (t1 ? 18.47 min for the binding glucose with surface of ZnO NPs and follows a single exponential association process.

  12. The methodology of glucose monitoring in type 2 diabetes mellitus

    Directory of Open Access Journals (Sweden)

    MIHAELA GRIBOVSCHI

    2013-11-01

    Full Text Available Type 2 diabetes is a chronic disease and maintaining a tight glycemic controlis essential to prevent both microvascular and macrovascular complications, asdemonstrated in previous studies. It is essential to monitor the glucose levels inorder to achieve the targets. The blood glucose monitoring can be done by differentmethods: glycated haemoglobin A1c, self-monitoring of blood glucose (before andafter meals with a glucometer and continuous glucose monitoring with a systemthat measures interstitial glucose concentrations. Even though glycated haemoglobinA1c is considered the “gold standard” of diabetes care, it does not provide completeinformation about the magnitude of the glycemic disequilibrium. Therefore the self-monitoring and continuous monitoring of blood glucose are considered an importantadjunct for achieving and maintaining optimal glycemic control. The three methods ofassessing glycemic control: HbA1c, SMBG and CGMS provide distinct but at the sametime complementary information

  13. Optical glucose sensing in biological fluids: an overview.

    Science.gov (United States)

    McNichols, R J; Coté, G L

    2000-01-01

    Recent technological advancements in the photonics industry have led to a resurgence of interest in optical glucose sensing and to realistic progress toward the development of an optical glucose sensor. Such a sensor has the potential to significantly improve the quality of life for the estimated 16 million diabetics in this country by making routine glucose measurements more convenient. Currently over 100 small companies and universities are working to develop noninvasive or minimally invasive glucose sensing technologies, and optical methods play a large role in these efforts. This article reviews many of the recent advances in optical glucose sensing including optical absorption spectroscopy, polarimetry, Raman spectroscopy, and fluorescent glucose sensing. In addition a review of calibration and data processing methods useful for optical techniques is presented. PMID:10938760

  14. Demographic and metabolic characteristics of individuals with progressive glucose tolerance

    Scientific Electronic Library Online (English)

    A.L., Mendes; M.L., Santos; C.R., Padovani; W.P., Pimenta.

    2009-03-01

    Full Text Available We evaluated changes in glucose tolerance of 17 progressors and 62 non-progressors for 9 years to improve our understanding of the pathogenesis of type 2 diabetes mellitus. Changes in anthropometric measurements and responses to an oral glucose tolerance test (OGTT) were analyzed. We identified 14 p [...] airs of individuals, one from each group, who were initially normal glucose tolerant and were matched for gender, age, weight, and girth. We compared initial plasma glucose and insulin curves (from OGTT), insulin secretion (first and second phases) and insulin sensitivity indices (from hyperglycemic clamp assay) for both groups. In the normal glucose tolerant phase, progressors presented: 1) a higher OGTT blood glucose response with hyperglycemia in the second hour and a similar insulin response vs non-progressors; 2) a reduced first-phase insulin secretion (2.0 ± 0.3 vs 2.3 ± 0.3 pmol/L; P

  15. Noninvasive blood glucose monitoring with laser diode

    Science.gov (United States)

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

    2006-02-01

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

  16. Glucose-6-phosphatase deficiency

    Directory of Open Access Journals (Sweden)

    Labrune Philippe

    2011-05-01

    Full Text Available Abstract Glucose-6-phosphatase deficiency (G6P deficiency, or glycogen storage disease type I (GSDI, is a group of inherited metabolic diseases, including types Ia and Ib, characterized by poor tolerance to fasting, growth retardation and hepatomegaly resulting from accumulation of glycogen and fat in the liver. Prevalence is unknown and annual incidence is around 1/100,000 births. GSDIa is the more frequent type, representing about 80% of GSDI patients. The disease commonly manifests, between the ages of 3 to 4 months by symptoms of hypoglycemia (tremors, seizures, cyanosis, apnea. Patients have poor tolerance to fasting, marked hepatomegaly, growth retardation (small stature and delayed puberty, generally improved by an appropriate diet, osteopenia and sometimes osteoporosis, full-cheeked round face, enlarged kydneys and platelet dysfunctions leading to frequent epistaxis. In addition, in GSDIb, neutropenia and neutrophil dysfunction are responsible for tendency towards infections, relapsing aphtous gingivostomatitis, and inflammatory bowel disease. Late complications are hepatic (adenomas with rare but possible transformation into hepatocarcinoma and renal (glomerular hyperfiltration leading to proteinuria and sometimes to renal insufficiency. GSDI is caused by a dysfunction in the G6P system, a key step in the regulation of glycemia. The deficit concerns the catalytic subunit G6P-alpha (type Ia which is restricted to expression in the liver, kidney and intestine, or the ubiquitously expressed G6P transporter (type Ib. Mutations in the genes G6PC (17q21 and SLC37A4 (11q23 respectively cause GSDIa and Ib. Many mutations have been identified in both genes,. Transmission is autosomal recessive. Diagnosis is based on clinical presentation, on abnormal basal values and absence of hyperglycemic response to glucagon. It can be confirmed by demonstrating a deficient activity of a G6P system component in a liver biopsy. To date, the diagnosis is most commonly confirmed by G6PC (GSDIa or SLC37A4 (GSDIb gene analysis, and the indications of liver biopsy to measure G6P activity are getting rarer and rarer. Differential diagnoses include the other GSDs, in particular type III (see this term. However, in GSDIII, glycemia and lactacidemia are high after a meal and low after a fast period (often with a later occurrence than that of type I. Primary liver tumors and Pepper syndrome (hepatic metastases of neuroblastoma may be evoked but are easily ruled out through clinical and ultrasound data. Antenatal diagnosis is possible through molecular analysis of amniocytes or chorionic villous cells. Pre-implantatory genetic diagnosis may also be discussed. Genetic counseling should be offered to patients and their families. The dietary treatment aims at avoiding hypoglycemia (frequent meals, nocturnal enteral feeding through a nasogastric tube, and later oral addition of uncooked starch and acidosis (restricted fructose and galactose intake. Liver transplantation, performed on the basis of poor metabolic control and/or hepatocarcinoma, corrects hypoglycemia, but renal involvement may continue to progress and neutropenia is not always corrected in type Ib. Kidney transplantation can be performed in case of severe renal insufficiency. Combined liver-kidney grafts have been performed in a few cases. Prognosis is usually good: late hepatic and renal complications may occur, however, with adapted management, patients have almost normal life span. Disease name and synonyms Glucose-6-phosphatase deficiency or G6P deficiency or glycogen storage disease type I or GSDI or type I glycogenosis or Von Gierke disease or Hepatorenal glycogenosis.

  17. Mean platelet volume as a marker of future cardiovascular disease risk in pregnant women with impaired fasting glucose and impaired glucose tolerance

    OpenAIRE

    Ko?s?u?s?, Nermin; Ko?s?u?s?, Ayd?n; Turhan, Nilgu?n

    2012-01-01

    To compare the mean platelet volume (MPV) of pregnant women with mild glycemic disorders with that of healthy pregnant women to find whether these disorders are risk factors for future cardiovascular disease. Materials and methods: Fasting blood glucose and 50-g oral glucose loading were measured. A 100-g, 3-h oral glucose tolerance test was done when plasma glucose was ?140 mg/dL, following a loading test. According to the test results, 4 groups were formed: control, impaired fast...

  18. Fast analog associative memory

    Science.gov (United States)

    Kinser, Jason M.

    1995-08-01

    Traditional neural networks such as backpropagation begin with a set of decision boundaries and optimize the network by moving the boundaries. The problem with this approach is a large number of iterations is required and the network can easily be stuck in a local minima. The algorithm presented here rapidly creates boundaries when necessary and destroys boundaries when they become obsolete. Optimization is achieved by a 'survival of the fittest' boundaries approach. Since the individual boundaries are not optimized the algorithm does not require iterations and trains the network very quickly. The algorithm is well suited for high- dimensional analog inputs and analog outputs.

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

    International Nuclear Information System (INIS)

    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 [6,6-2H]glucose and [U-13C]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. Glucos rise in urinary glucose excretion. Glucose tissue uptake, as well as glucose oxidation, did not vary between normoglycemic and hyperglycemic states

  20. Predicting Plasma Glucose From Interstitial Glucose Observations Using Bayesian Methods.

    Science.gov (United States)

    Hansen, Alexander Hildenbrand; Duun-Henriksen, Anne Katrine; Juhl, Rune; Schmidt, Signe; Nørgaard, Kirsten; Jørgensen, John Bagterp; Madsen, Henrik

    2014-03-01

    One way of constructing a control algorithm for an artificial pancreas is to identify a model capable of predicting plasma glucose (PG) from interstitial glucose (IG) observations. Stochastic differential equations (SDEs) make it possible to account both for the unknown influence of the continuous glucose monitor (CGM) and for unknown physiological influences. Combined with prior knowledge about the measurement devices, this approach can be used to obtain a robust predictive model. A stochastic-differential-equation-based gray box (SDE-GB) model is formulated on the basis of an identifiable physiological model of the glucoregulatory system for type 1 diabetes mellitus (T1DM) patients. A Bayesian method is used to estimate robust parameters from clinical data. The models are then used to predict PG from IG observations from 2 separate study occasions on the same patient. First, all statistically significant diffusion terms of the model are identified using likelihood ratio tests, yielding inclusion of [Formula: see text], [Formula: see text], and [Formula: see text]. Second, estimates using maximum likelihood are obtained, but prediction capability is poor. Finally a Bayesian method is implemented. Using this method the identified models are able to predict PG using only IG observations. These predictions are assessed visually. We are also able to validate these estimates on a separate data set from the same patient. This study shows that SDE-GBs and a Bayesian method can be used to identify a reliable model for prediction of PG using IG observations obtained with a CGM. The model could eventually be used in an artificial pancreas. PMID:24876584

  1. Glucose Regulates the Expression of the Apolipoprotein A5 Gene

    Energy Technology Data Exchange (ETDEWEB)

    Fruchart, Jamila; Nowak, Maxime; Helleboid-Chapman, Audrey; Jakel, Heidelinde; Moitrot, Emmanuelle; Rommens, Corinne; Pennacchio, Len A.; Fruchart-Najib, Jamila; Fruchart, Jean-Charles

    2008-04-07

    The apolipoprotein A5 gene (APOA5) is a key player in determining triglyceride concentrations in humans and mice. Since diabetes is often associated with hypertriglyceridemia, this study explores whether APOA5 gene expression is regulated by alteration in glucose homeostasis and the related pathways. D-glucose activates APOA5 gene expression in a time- and dose-dependent manner in hepatocytes, and the glycolytic pathway involved was determined using D-glucose analogs and metabolites. Together, transient transfections, electrophoretic mobility shift assays and chromatin immunoprecipitation assays show that this regulation occurs at the transcriptional level through an increase of USF1/2 binding to an E-box in the APOA5 promoter. We show that this phenomenon is not due to an increase of mRNA or protein expression levels of USF. Using protein phosphatases 1 and 2A inhibitor, we demonstrate that D-glucose regulates APOA5 gene via a dephosphorylation mechanism, thereby resulting in an enhanced USF1/2-promoter binding. Last, subsequent suppressions of USF1/2 and phosphatases mRNA through siRNA gene silencing abolished the regulation. We demonstrate that APOA5 gene is up regulated by D-glucose and USF through phosphatase activation. These findings may provide a new cross talk between glucose and lipid metabolism.

  2. Radiotracers in the study of marine food chains. The use of compartmental analysis and analog modelling in measuring utilization rates of particulate organic matter by benthic invertebrates

    International Nuclear Information System (INIS)

    The present study assesses the problem of recycling when using radiotracers to quantify ingestion and assimilation rates of particulate organic matter by benthic invertebrates. The rapid production of dissolved organic matter and its subsequent utilization by benthic invertebrates constitutes a major bias in this kind of study. However recycling processes may also concern POM through the production and reingestion of faeces. The present paper shows that compartmental analysis of the diffusion kinetics of the radiotracer between the different compartments of the system studied and the analog modelling of the exchanges of radioactivity between compartments may be used in order to determine ingestion and assimilation rates. This method is illustrated by the study of a system composed of the bacteria Lactobacillus sp. and the filter-feeding bivalve Venerupis decussata. The advantages and drawbacks of this approach relative to other existing methods are briefly discussed. (Author)

  3. Hyperglycemia (High Blood Glucose)

    Medline Plus

    Full Text Available ... your blood glucose level. Cutting down on the amount of food you eat might also help. Work with your dietitian to make changes in your ... exercise and changes in your diet don't work, your doctor may change the amount of your medication or insulin or possibly the ...

  4. Fructose, Glucose and Hunger

    Medline Plus

    Full Text Available ... About MedlinePlus Site Map FAQs Contact Us Health Topics Drugs & Supplements Videos & Tools You Are Here: Home ? Latest Health News ? Fructose, Glucose and Hunger URL of this page: http://www.nlm.nih.gov/medlineplus/videos/news/ ...

  5. Blood Test: Glucose

    Science.gov (United States)

    ... especially those who specialize in treating diabetes, have blood-analysis equipment in their office and will be able to analyze the results right away. Sometimes, though, the doctor also may send a blood sample to the lab. Risks The blood glucose ...

  6. Pancreatoscintigraphy after glucose load

    International Nuclear Information System (INIS)

    Analysing the results of the effect of various types of patient's preparation for pancreatoscintigraphy, intravenous administration of glucose (0.33 g/kg) 50 min before administration of 75Se-methionine and sup(99m)Tc-colloidum seems appropriate. Under ambulatory conditions pancreatoscintigraphy should be performed without any preparation and not on empty stomach

  7. Quantum Analog Computing

    Science.gov (United States)

    Zak, M.

    1998-01-01

    Quantum analog computing is based upon similarity between mathematical formalism of quantum mechanics and phenomena to be computed. It exploits a dynamical convergence of several competing phenomena to an attractor which can represent an externum of a function, an image, a solution to a system of ODE, or a stochastic process.

  8. Analog signal isolation techniques

    International Nuclear Information System (INIS)

    This paper discusses several techniques for isolating analog signals in an accelerator environment. The techniques presented here encompass isolation amplifiers, voltage-to-frequency converters (VIFCs), transformers, optocouplers, discrete fiber optics, and commercial fiber optic links. Included within the presentation of each method are the design issues that must be considered when selecting the isolation method for a specific application

  9. Predictive models of glucose control: roles for glucose-sensing neurones.

    Science.gov (United States)

    Kosse, C; Gonzalez, A; Burdakov, D

    2015-01-01

    The brain can be viewed as a sophisticated control module for stabilizing blood glucose. A review of classical behavioural evidence indicates that central circuits add predictive (feedforward/anticipatory) control to the reactive (feedback/compensatory) control by peripheral organs. The brain/cephalic control is constructed and engaged, via associative learning, by sensory cues predicting energy intake or expenditure (e.g. sight, smell, taste, sound). This allows rapidly measurable sensory information (rather than slowly generated internal feedback signals, e.g. digested nutrients) to control food selection, glucose supply for fight-or-flight responses or preparedness for digestion/absorption. Predictive control is therefore useful for preventing large glucose fluctuations. We review emerging roles in predictive control of two classes of widely projecting hypothalamic neurones, orexin/hypocretin (ORX) and melanin-concentrating hormone (MCH) cells. Evidence is cited that ORX neurones (i) are activated by sensory cues (e.g. taste, sound), (ii) drive hepatic production, and muscle uptake, of glucose, via sympathetic nerves, (iii) stimulate wakefulness and exploration via global brain projections and (iv) are glucose-inhibited. MCH neurones are (i) glucose-excited, (ii) innervate learning and reward centres to promote synaptic plasticity, learning and memory and (iii) are critical for learning associations useful for predictive control (e.g. using taste to predict nutrient value of food). This evidence is unified into a model for predictive glucose control. During associative learning, inputs from some glucose-excited neurones may promote connections between the 'fast' senses and reward circuits, constructing neural shortcuts for efficient action selection. In turn, glucose-inhibited neurones may engage locomotion/exploration and coordinate the required fuel supply. Feedback inhibition of the latter neurones by glucose would ensure that glucose fluxes they stimulate (from liver, into muscle) are balanced. Estimating nutrient challenges from indirect sensory cues may become more difficult when the cues become complex and variable (e.g. like human foods today). Consequent errors of predictive glucose control may contribute to obesity and diabetes. PMID:25131833

  10. Glucose metabolism in mice during and after whole-body hyperthermia

    International Nuclear Information System (INIS)

    Researchers studied glucose turnover in male inbred mice during and after whole-body hyperthermia for 1 hour at 40 degrees or 41 degrees C by giving them injections of [14C]glucose with and without a glucose load and measuring the expired 14Co2. Expiration of 14CO2 was increased during hyperthermia but decreased considerably afterward. The latter effect was enhanced by a glucose load. This inhibition depended on the glucose concentration. Metabolic studies showed a depletion of several glycolytic metabolites, especially glycogen and lactate, after whole-body hyperthermia. Combined treatment of hyperthermia and a glucose injection 1 hour later led to an increased level of glucose 6-phosphate, which indicated a block in glycolysis between glucose 6-phosphate and fructose 1,6-diphosphate. This inhibition did not occur when glucose was given before the hyperthermia treatment. Lactate accumulation was not observed under any conditions

  11. Assessment of insulin action in insulin-dependent diabetes mellitus using [6(14)C]glucose, [3(3)H]glucose, and [2(3)H]glucose. Differences in the apparent pattern of insulin resistance depending on the isotope used

    International Nuclear Information System (INIS)

    To determine whether [2(3)H], [3(3)H], and [6(14)C]glucose provide an equivalent assessment of glucose turnover in insulin-dependent diabetes mellitus (IDDM) and nondiabetic man, glucose utilization rates were measured using a simultaneous infusion of these isotopes before and during hyperinsulinemic euglycemic clamps. In the nondiabetic subjects, glucose turnover rates determined with [6(14)C]glucose during insulin infusion were lower (P less than 0.02) than those determined with [2(3)H]glucose and higher (P less than 0.01) than those determined with [3(3)H]glucose. In IDDM, glucose turnover rates measured with [6(14)C]glucose during insulin infusion were lower (P less than 0.05) than those determined with [2(3)H]glucose, but were not different from those determined with [3(3)H]glucose. All three isotopes indicated the presence of insulin resistance. However, using [3(3)H]glucose led to the erroneous conclusion that glucose utilization was not significantly decreased at high insulin concentrations in the diabetic patients. [6(14)C] and [3(3)H]glucose but not [2(3)H]glucose indicated impairment in insulin-induced suppression of glucose production. These results indicate that tritiated isotopes do not necessarily equally reflect the pattern of glucose metabolism in diabetic and nondiabetic man

  12. Structure-function relationships affecting the sensing mechanism of monolayer-protected cluster doped xerogel amperometric glucose biosensors.

    Science.gov (United States)

    DiPasquale, Luke T; Poulos, Nicholas G; Hall, Jackson R; Minocha, Aastha; Bui, Tram Anh; Leopold, Michael C

    2015-07-15

    A systematic study of the structure-function relationships critical to understanding the sensing mechanism of 1st generation amperometric glucose biosensors with an embedded nanoparticle (NP) network is presented. Xerogel-based films featuring embedded glucose oxidase enzyme and doped with alkanethiolate-protected gold NPs, known as monolayer protected clusters (MPCs), exhibit significantly enhanced performance compared to analogous systems without NPs including higher sensitivity, faster response time, and extended linear/dynamic ranges. The proposed mechanism involves diffusion of the glucose to glucose oxidase within the xerogel, enzymatic reaction production of H2O2 with subsequent diffusion to the embedded network of MPCs where it is oxidized, an event immediately reported via fast electron transfer (ET) through the MPC system to the working electrode. Various aspects of the film construct and strategy are systematically probed using amperometry, voltammetry, and solid-state electronic conductivity measurements, including the effects of MPC peripheral chain length, MPC functionalization via place-exchange reaction, MPC core size, and the MPC density or concentration within the xerogel composite films. The collective results of these experiments support the proposed mechanism and identify interparticle spacing and the electronic communication through the MPC network is the most significant factor in the sensing scheme with the diffusional aspects of the mechanism that may be affected by film/MPC hydrophobicity and functionality (i.e., glucose and H2O2 diffusion) shown to be less substantial contributors to the overall enhanced performance. Understanding the structure-function relationships of effective sensing schemes allows for the employment of the strategy for future biosensor design toward clinically relevant targets. PMID:25819004

  13. Recent advances in noninvasive glucose monitoring

    Directory of Open Access Journals (Sweden)

    So CF

    2012-06-01

    Full Text Available Chi-Fuk So,1 Kup-Sze Choi,1 Thomas KS Wong,2 Joanne WY Chung2,31Centre for Integrative Digital Health, School of Nursing, The Hong Kong Polytechnic University, Hong Kong, 2Department of Nursing and Health Sciences, Tung Wah College, Hong Kong, 3Department of Health and Physical Education, The Hong Kong Institute of Education, Hong KongAbstract: The race for the next generation of painless and reliable glucose monitoring for diabetes mellitus is on. As technology advances, both diagnostic techniques and equipment improve. This review describes the main technologies currently being explored for noninvasive glucose monitoring. The principle of each technology is mentioned; its advantages and limitations are then discussed. The general description and the corresponding results for each device are illustrated, as well as the current status of the device and the manufacturer; internet references for the devices are listed where appropriate. Ten technologies and eleven potential devices are included in this review. Near infrared spectroscopy has become a promising technology, among others, for blood glucose monitoring. Although some reviews have been published already, the rapid development of technologies and information makes constant updating mandatory. While advances have been made, the reliability and the calibration of noninvasive instruments could still be improved, and more studies carried out under different physiological conditions of metabolism, bodily fluid circulation, and blood components are needed.Keywords: noninvasive, glucose monitoring, diabetes mellitus, blood glucose measurement

  14. Modification of postprandial hyperglycemia with insulin lispro improves glucose control in patients with type 2 diabetes.

    OpenAIRE

    Feinglos, Mn; Thacker, Ch; English, J.; Bethel, Ma; Lane, Jd

    1997-01-01

    OBJECTIVE: Insulin lispro is a rapid-acting analog of human insulin that can be used to target the postprandial rise in plasma glucose. We designed an open-label randomized crossover study of type 2 diabetic patients with secondary failure of sulfonylurea therapy to determine whether improvement of postprandial hyperglycemia would affect total daily glucose control. RESEARCH DESIGN AND METHODS: Twenty-five type 2 diabetic patients who were poorly controlled on a maximum dose of sulfonylureas ...

  15. Funcionamento diferencial dos itens (DIF: estudo com analogias para medir o raciocínio verbal Differential items functioning (DIF: study with analogies for measurement the verbal reasoning

    Directory of Open Access Journals (Sweden)

    Wagner Bandeira Andriola

    2000-01-01

    Full Text Available Este estudo objetivou determinar o funcionamento diferencial de 30 analogias destinadas à avaliação do raciocínio verbal, considerando a variável sexo. Utilizou-se uma amostra de 730 alunos do Ensino Médio, com idade média de 17,74 anos (dp= 3,12 anos. A maioria procedia de escolas públicas (58,5% e era do sexo feminino (53,2%. Os grupos organizados para a investigação foram compostos por homens (n=342 e mulheres (n=388. Os parâmetros métricos dos itens foram determinados pelo modelo TRI de dois parâmetros logísticos. Para a verificação do DIF foram comparados os parâmetros métricos dos itens. Os resultados indicaram a presença de cinco itens com DIF.This research aimed the determination of the differential item functioning (DIF in 30 analogies used for the verbal reasoning assessment in students, taking into account the sex variable. A sample of 730 high school students, whose average age was 17,74 years (sd = 3,12 years was used. The majority was composed by students from public schools (58,4% and females (53,3%. The groups which participated in the study of DIF were composed by men (n= 342 and women (n= 388. The metric parameters of the items were determined according to the TRI model of two logistics parameters. For the determination of the DIF the method of comparation of the metric parameters of the items was used. The results indicated the presence of five items with DIF.

  16. Funcionamento diferencial dos itens (DIF): estudo com analogias para medir o raciocínio verbal / Differential items functioning (DIF): study with analogies for measurement the verbal reasoning

    Scientific Electronic Library Online (English)

    Wagner Bandeira, Andriola.

    Full Text Available Este estudo objetivou determinar o funcionamento diferencial de 30 analogias destinadas à avaliação do raciocínio verbal, considerando a variável sexo. Utilizou-se uma amostra de 730 alunos do Ensino Médio, com idade média de 17,74 anos (dp= 3,12 anos). A maioria procedia de escolas públicas (58,5%) [...] e era do sexo feminino (53,2%). Os grupos organizados para a investigação foram compostos por homens (n=342) e mulheres (n=388). Os parâmetros métricos dos itens foram determinados pelo modelo TRI de dois parâmetros logísticos. Para a verificação do DIF foram comparados os parâmetros métricos dos itens. Os resultados indicaram a presença de cinco itens com DIF. Abstract in english This research aimed the determination of the differential item functioning (DIF) in 30 analogies used for the verbal reasoning assessment in students, taking into account the sex variable. A sample of 730 high school students, whose average age was 17,74 years (sd = 3,12 years) was used. The majorit [...] y was composed by students from public schools (58,4%) and females (53,3%). The groups which participated in the study of DIF were composed by men (n= 342) and women (n= 388). The metric parameters of the items were determined according to the TRI model of two logistics parameters. For the determination of the DIF the method of comparation of the metric parameters of the items was used. The results indicated the presence of five items with DIF.

  17. Entry rates and recycling of glucose in buffalo calves fed on urea molasses liquid diet

    International Nuclear Information System (INIS)

    Entry rates of glucose have been measured in buffalo calves by using a dual-isotope dilution method based on continuous infusion of (U-14C)D-glucose and (6-3H)D-glucose into the blood at a precise controlled rate for 540 min. After 5 h a plateau was obtained in the specific radioactivity of the plasma glucose from which glucose synthesis and entry rates were calculated. The average entry rates of glucose were 112 and 145 mg/min measured by 14C and 3H labelled glucose respectively. About 23 percent of the glucose carbon was recycled in the pool. The average recycling rate was 33 mg/min. (author)

  18. Spiral structure in galaxies: analogies

    Energy Technology Data Exchange (ETDEWEB)

    Kirkpatrick, R.C.

    1976-01-01

    The vortex analogy to galactic spiral structures is considered. Caution against carrying the analogy past its region of applicability is noted; and some experiments with vorticities are mentioned. (JFP)

  19. Terrestrial Spaceflight Analogs: Antarctica

    Science.gov (United States)

    Crucian, Brian

    2013-01-01

    Alterations in immune cell distribution and function, circadian misalignment, stress and latent viral reactivation appear to persist during Antarctic winterover at Concordia Station. Some of these changes are similar to those observed in Astronauts, either during or immediately following spaceflight. Others are unique to the Concordia analog. Based on some initial immune data and environmental conditions, Concordia winterover may be an appropriate analog for some flight-associated immune system changes and mission stress effects. An ongoing smaller control study at Neumayer III will address the influence of the hypoxic variable. Changes were observed in the peripheral blood leukocyte distribution consistent with immune mobilization, and similar to those observed during spaceflight. Alterations in cytokine production profiles were observed during winterover that are distinct from those observed during spaceflight, but potentially consistent with those observed during persistent hypobaric hypoxia. The reactivation of latent herpesviruses was observed during overwinter/isolation, that is consistently associated with dysregulation in immune function.

  20. 1-/sup 11/C-2-deoxy-D-glucose and process for the preparation thereof

    Science.gov (United States)

    MacGregor, R.R.; Wolf, A.P.; Shiue, C.Y.; Wan, C.N.

    1980-02-08

    The novel labelled compound 1-/sup 11/C-2-deoxy-D-glucose, and a process for its preparation from 2,3:4,5-di-O-isopropylidene-D-arabinitol derivatives of relatively high reactivity are disclosed. 1-/sup 11/C-2-deoxy-D-glucose is useful for measuring regional brain glucose metabolism in vivo.

  1. Glucose-6-phosphatase deficiency.

    OpenAIRE

    Labrune Philippe; Gajdos Vincent; Eberschweiler Pascale; Hubert-Buron Aurélie; Petit François; Vianey-Saban Christine; Boudjemline Alix; Piraud Monique; Froissart Roseline

    2011-01-01

    Abstract Glucose-6-phosphatase deficiency (G6P deficiency), or glycogen storage disease type I (GSDI), is a group of inherited metabolic diseases, including types Ia and Ib, characterized by poor tolerance to fasting, growth retardation and hepatomegaly resulting from accumulation of glycogen and fat in the liver. Prevalence is unknown and annual incidence is around 1/100,000 births. GSDIa is the more frequent type, representing about 80% of GSDI patients. The disease commonly manifests, betw...

  2. Antarctic analogs for Enceladus

    Science.gov (United States)

    Murray, A. E.; Andersen, D. T.; McKay, C. P.

    2014-12-01

    Enceladus is a new world for Astrobiology. The Cassini discovery of the icy plume emanating from the South Polar region indicates an active world, where detection of water, organics, sodium, and nano-particle silica in the plume strongly suggests that the source is a subsurface salty ocean reservoir. Recent gravity data from Cassini confirms the presence of a regional sea extending north to 50°S. An ocean habitat under a thick ice cover is perhaps a recurring theme in the Outer Solar System, but what makes Enceladus unique is that the plume jetting out into space is carrying samples of this ocean. Therefore, through the study of Enceladus' plumes we can gain new insights not only of a possible habitable world in the Solar Systems, but also about the formation and evolution of other icy-satellites. Cassini has been able to fly through this plume - effectively sampling the ocean. It is time to plan for future missions that do more detailed analyses, possibly return samples back to Earth and search for evidence of life. To help prepare for such missions, the need for earth-based analog environments is essential for logistical, methodological (life detection) and theoretical development. We have undertaken studies of two terrestrial environments that are close analogs to Enceladus' ocean: Lake Vida and Lake Untersee - two ice-sealed Antarctic lakes that represent physical, chemical and possibly biological analogs for Enceladus. By studying the diverse biology and physical and chemical constraints to life in these two unique lakes we will begin to understand the potential habitability of Enceladus and other icy moons, including possible sources of nutrients and energy, which together with liquid water are the key ingredients for life. Analog research such as this will also enable us to develop and test new strategies to search for evidence of life on Enceladus.

  3. Analog Signal Processing

    OpenAIRE

    Caloz, Christophe; Gupta, Shulabh; Zhang, Qingfeng; Nikfal, Babak

    2013-01-01

    Analog signal processing (ASP) is presented as a systematic approach to address future challenges in high speed and high frequency microwave applications. The general concept of ASP is explained with the help of examples emphasizing basic ASP effects, such as time spreading and compression, chirping and frequency discrimination. Phasers, which represent the core of ASP systems, are explained to be elements exhibiting a frequency-dependent group delay response, and hence a no...

  4. The interaction among glucose transport, hexokinase, and glucose-6-phosphatase with respect to 3H-2-deoxyglucose retention in murine tumor model

    International Nuclear Information System (INIS)

    The development of new diagnostic/therapeutic modalities for cancer requires a specific understanding of how tumors differ from normal tissues. Though the key components involved in the selective accumulation of 2-deoxy-D-glucose (2-DG) analogs in tumors are known, the relative importance of each is controversial. For this reason glucose transport protein (GLUT) density, hexokinase/glucose-6-phosphatase (GP) activity, and 2-DG biodistribution were measured together in four tumor models and normal murine tissues. Direct binding studies with 3H-cytochalasin B showed that GLUT density was elevated 20-fold in LX-1 tumors. Immunohistochemically in all tumors, the expression of GLUT-1 was highest in the necrotic/perinecrotic foci and similar in cells not adjacent to necrotic foci. As the retention of 3H-2-DG was similar in all tumors, these data suggest that the GLUT-1 in perinecrotic tumor cells were not rate limiting for 3H-2-DG uptake. Kidney, liver, and lung had high GP activity and rapid clearance of 3H-2-DG. Sodium orthovanadate (5 ?mol), a GP inhibitor, increased the concentration of 3H-2-DG in these tissues, suggesting that GP is a rate-limiting enzyme for 3H-2-DG clearance. All tumor homogenates had low GP activity, and hexokinase activity was not elevated compared to normal tissues. Thus, in the tumors studied, the selective accumulation of 3H-2-DG consistently occurred in the absence ofG consistently occurred in the absence of significant GP activity without the marked overexpression of hexokinase or GLUT

  5. Real-time dual wavelength polarimetry for glucose sensing

    Science.gov (United States)

    Malik, Bilal H.; Coté, Gerard L.

    2009-02-01

    Proper treatment of diabetes includes maintenance of near normal blood glucose levels, which can only be achieved with frequent blood glucose monitoring. Current blood finger-stick methods for glucose sensing are invasive, often resulting in low patient compliance and poor disease control. The development of a noninvasive glucose sensor has the potential to provide optimal management of diabetes. Our proposed noninvasive approach is based on an optical polarimetry system for probing the anterior chamber of the eye. The sensor would eventually be used to measure the aqueous humor glucose concentration as a means to determine the blood glucose concentration. In this report, we present the development of a near real-time (less than 1 second) dual wavelength closed-loop polarimetric system to minimize glucose prediction error in the presence of varying birefringence due to motion artifact. The new dual wavelength polarimetric system and in vitro glucose measurement results will be presented which demonstrate the sensitivity and accuracy of the system in the presence of varying birefringence.

  6. Neuroendocrine responses to glucose ingestion in man. Specificity, temporal relationships, and quantitative aspects

    OpenAIRE

    Tse, Thomas F.; Clutter, William E.; Shah, Suresh D.; Miller, J. Philip; Cryer, Philip E.

    1983-01-01

    The mechanisms of postprandial glucose counterregulation—those that blunt late decrements in plasma glucose, prevent hypoglycemia, and restore euglycemia—have not been fully defined. To begin to clarify these mechanisms, we measured neuroendocrine and metabolic responses to the ingestion of glucose (75 g), xylose (62.5 g), mannitol (20 g), and water in ten normal human subjects to determine for each response the magnitude, temporal relationships, and specificity for glucose ingestion. Mea...

  7. Factors Associated with Increases in Glucose Levels in the Perioperative Period in Non-Diabetic Patients

    OpenAIRE

    Manasee Sant; Alejandro F. Castro III; Catherine Schoenberg; Vasanti Tilak

    2013-01-01

    Background: Blood glucose levels are elevated during the perioperative period as a result of the neuro-endocrine response to the stress of surgery. In nondiabetic patients, blood glucose levels are not a part of routine preoperative testing nor are they monitored during surgery or in the post anesthesia care unit (PACU). We measured blood glucose levels in nondiabetic patients during the perioperative period to identify how many patients had high glucose levels and what factors were associat...

  8. Quality assessment of patients’ self-monitoring of blood glucose in community pharmacies

    OpenAIRE

    Kjome RL; Granas AG; Nerhus K; Sandberg S

    2010-01-01

    Objective: To evaluate diabetes patients’ selfmonitoring of blood glucose using a community pharmacy-based quality assurance procedure, to investigate whether the procedure improved the quality of the patient performance of self monitoring of blood glucose, and to examine the opinions of the patients taking part in the study. Methods: The results of patient blood glucose measurements were compared to the results obtained with HemoCue Glucose 201+ by pharmacy empl...

  9. Influence of glucose and urea on 125I transport across an anion exchange paper membrane

    International Nuclear Information System (INIS)

    In order to study the influence of glucose and urea on the 125I transport across an anion exchange paper membrane, the transmembrane potential, the fluxes, and the concentrations of 125I, glucose and urea within the membrane were measured in the Na125I concentration-cell system containing glucose or urea. Glucose and urea increased the membrane/solution distribution of the iodide ion, but scarcely affected the diffusion process of iodide ion within the membrane

  10. Delays in Minimally Invasive Continuous Glucose Monitoring Devices: A Review of Current Technology

    OpenAIRE

    Keenan, D. Barry; Mastrototaro, John J; Voskanyan, Gayane; Steil, Garry M

    2009-01-01

    Through the use of enzymatic sensors—inserted subcutaneously in the abdomen or ex vivo by means of microdialysis fluid extraction—real-time minimally invasive continuous glucose monitoring (CGM) devices estimate blood glucose by measuring a patient's interstitial fluid (ISF) glucose concentration. Signals ac-quired from the interstitial space are subsequently calibrated with capillary blood glucose samples, a method that has raised certain questions regarding the effects of physiological time...

  11. Glucose tolerance in patients with cystic fibrosis: five year prospective study.

    OpenAIRE

    Lanng, S.; Hansen, A.; Thorsteinsson, B.; Nerup, J.; Koch, C.

    1995-01-01

    OBJECTIVES--To study prevalence and incidence of diabetes mellitus in patients with cystic fibrosis. DESIGN--Five year prospective study with annual oral glucose tolerance tests. SETTING--CF Center Copenhagen, Denmark. SUBJECTS--191 patients with cystic fibrosis aged above 2 years. MAIN OUTCOME MEASURES--Glucose tolerance, plasma glucose concentrations after fasting and after glucose loading, and haemoglobin A1c levels. RESULTS--Prevalence of diabetes increased from 11% (n = 21) to 24% (n = 4...

  12. Novel phosphoenolpyruvate-dependent futile cycle in Streptococcus lactis: 2-deoxy-D-glucose uncouples energy production from growth.

    OpenAIRE

    Thompson, J.; Chassy, B. M.

    1982-01-01

    The addition of 2-deoxy-D-glucose to cultures of Streptococcus lactis 133 that were growing exponentially on sucrose or lactose reduced the growth rate by ca. 95%. Inhibition did not occur with glucose or mannose as the growth sugar. The reduction in growth rate was concomitant with rapid accumulation of the analog in phosphorylated form (2-deoxy-D-glucose 6-phosphate) via the phosphoenolpyruvate-dependent mannose:phosphotransferase system. Within 5 min the intracellular 2-deoxy-D-glucose 6-p...

  13. Analogy and mathematical reasoning : a survey

    OpenAIRE

    Miller, C. D. F.

    1983-01-01

    We survey the literature of Artificial Intelligence, and other related work, pertaining to the modelling of mathematical reasoning and its relationship with the use of analogy. In particular, we discuss the contribution of Lenat's program AM to models of mathematical discovery and concept-formation. We consider the use of similarity measures to structure a knowledge space and their role in concept acquisition.

  14. Alternansucrase acceptor reactions with D-tagatose and L-glucose.

    Science.gov (United States)

    Côté, Gregory L; Dunlap, Christopher A; Appell, Michael; Momany, Frank A

    2005-02-01

    Alternansucrase (EC 2.4.1.140) is a d-glucansucrase that synthesizes an alternating alpha-(1-->3), (1-->6)-linked d-glucan from sucrose. It also synthesizes oligosaccharides via d-glucopyranosyl transfer to various acceptor sugars. Two of the more efficient monosaccharide acceptors are D-tagatose and L-glucose. In the presence of d-tagatose, alternansucrase produced the disaccharide alpha-d-glucopyranosyl-(1-->1)-beta-D-tagatopyranose via glucosyl transfer. This disaccharide is analogous to trehalulose. We were unable to isolate a disaccharide product from L-glucose, but the trisaccharide alpha-D-glucopyranosyl-(1-->6)-alpha-d-glucopyranosyl-(1-->4)-l-glucose was isolated and identified. This is analogous to panose, one of the structural units of pullulan, in which the reducing-end D-glucose residue has been replaced by its L-enantiomer. The putative L-glucose disaccharide product, produced by glucoamylase hydrolysis of the trisaccharide, was found to be an acceptor for alternansucrase. The disaccharide, alpha-D-glucopyranosyl-(1-->4)-L-glucose, was a better acceptor than maltose, previously the best known acceptor for alternansucrase. A structure comparison of alpha-D-glucopyranosyl-(1-->4)-L-glucose and maltose was performed through computer modeling to identify common features, which may be important in acceptor affinity by alternansucrase. PMID:15639245

  15. Close interrelationships among glucose oxidation

    International Nuclear Information System (INIS)

    The authors have reported that alloxan, a ?-cytotoxic agent, inhibited glucose oxidation and glucose-induced 45Ca uptake of pancreatic ?-cells; the non-?-cell mass was not inhibited by alloxan pretreatment. Therefore it is feasible to assess glucose metabolism and Ca uptake in the mass composed of ?-cells alone, by subtracting glucose oxidation and Ca uptake in the alloxan treated islets from the non-alloxan treatted islets. In order to elucidate the interrelationship between glycolysis, glucose-induced Ca uptake and insulin release in the pancreatic ?-cell mass, but not in the pancreatic islets, we investigated 14CO2 formation from 14C-U-D-glucose, glucose-induced 45Ca uptake and insulin release in alloxan treated and non-alloxan treated islets. In vitro incubation of collagenase digested isolated islets of Langerhans was employed. The relationships between the three parameters in the presumed pancreatic ?-cell mass (14CO2 formation from 14C-U-D-glucose, glucose-induced 45Ca uptake and insulin release) and glucose concentration in the media were clearly sigmoidal. The threshold values of the three parameters are approximately 5 mM of glucose. The half maximum rates of 14CO2 formation, 45Ca uptake and insulin release required 13.4 mM, 13.6 mM and 12.8 mM of glucose, respectively. The near maximum stimulation of the three parameters stimulation of the three parameters was obtained at 20 mM of glucose. (orig.)

  16. Statins Impair Glucose Uptake in Tumor Cells1

    Science.gov (United States)

    Malenda, Agata; Skrobanska, Anna; Issat, Tadeusz; Winiarska, Magdalena; Bil, Jacek; Oleszczak, Bozenna; Sinski, Maciej; Firczuk, Ma?gorzata; Bujnicki, Janusz M; Chlebowska, Justyna; Staruch, Adam D; Glodkowska-Mrowka, Eliza; Kunikowska, Jolanta; Krolicki, Leszek; Szablewski, Leszek; Gaciong, Zbigniew; Koziak, Katarzyna; Jakobisiak, Marek; Golab, Jakub; Nowis, Dominika A

    2012-01-01

    Statins, HMG-CoA reductase inhibitors, are used in the prevention and treatment of cardiovascular diseases owing to their lipid-lowering effects. Previous studies revealed that, by modulating membrane cholesterol content, statins could induce conformational changes in cluster of differentiation 20 (CD20) tetraspanin. The aim of the presented study was to investigate the influence of statins on glucose transporter 1 (GLUT1)-mediated glucose uptake in tumor cells. We observed a significant concentration- and time-dependent decrease in glucose analogs' uptake in several tumor cell lines incubated with statins. This effect was reversible with restitution of cholesterol synthesis pathway with mevalonic acid as well as with supplementation of plasma membrane with exogenous cholesterol. Statins did not change overall GLUT1 expression at either transcriptional or protein levels. An exploratory clinical trial revealed that statin treatment decreased glucose uptake in peripheral blood leukocytes and lowered 18F-fluorodeoxyglucose (18F-FDG) uptake by tumor masses in a mantle cell lymphoma patient. A bioinformatics analysis was used to predict the structure of human GLUT1 and to identify putative cholesterol-binding motifs in its juxtamembrane fragment. Altogether, the influence of statins on glucose uptake seems to be of clinical significance. By inhibiting 18F-FDG uptake, statins can negatively affect the sensitivity of positron emission tomography, a diagnostic procedure frequently used in oncology. PMID:22577346

  17. ESD analog circuits and design

    CERN Document Server

    Voldman, Steven H

    2014-01-01

    A comprehensive and in-depth review of analog circuit layout, schematic architecture, device, power network and ESD design This book will provide a balanced overview of analog circuit design layout, analog circuit schematic development, architecture of chips, and ESD design.  It will start at an introductory level and will bring the reader right up to the state-of-the-art. Two critical design aspects for analog and power integrated circuits are combined. The first design aspect covers analog circuit design techniques to achieve the desired circuit performance. The second and main aspect pres

  18. An electronic analog of synthetic genetic networks.

    Science.gov (United States)

    Hellen, Edward H; Volkov, Evgenii; Kurths, Jurgen; Dana, Syamal Kumar

    2011-01-01

    An electronic analog of a synthetic genetic network known as the repressilator is proposed. The repressilator is a synthetic biological clock consisting of a cyclic inhibitory network of three negative regulatory genes which produces oscillations in the expressed protein concentrations. Compared to previous circuit analogs of the repressilator, the circuit here takes into account more accurately the kinetics of gene expression, inhibition, and protein degradation. A good agreement between circuit measurements and numerical prediction is observed. The circuit allows for easy control of the kinetic parameters thereby aiding investigations of large varieties of potential dynamics. PMID:21829723

  19. Nervous glucose sensing regulates postnatal ? cell proliferation and glucose homeostasis

    OpenAIRE

    Tarussio, David; Metref, Salima; Seyer, Pascal; Mounien, Lourdes; Vallois, David; Magnan, Christophe; Foretz, Marc; Thorens, Bernard

    2013-01-01

    How glucose sensing by the nervous system impacts the regulation of ? cell mass and function during postnatal development and throughout adulthood is incompletely understood. Here, we studied mice with inactivation of glucose transporter 2 (Glut2) in the nervous system (NG2KO mice). These mice displayed normal energy homeostasis but developed late-onset glucose intolerance due to reduced insulin secretion, which was precipitated by high-fat diet feeding. The ? cell mass of adult NG2KO mice ...

  20. Microcalorimetric study of glucose permeation in microbial cells.

    Science.gov (United States)

    Belaich, J P; Senez, J C; Murgier, M

    1968-05-01

    A microcalorimetric method for measuring the influence of extracellular glucose concentration on the rate of catabolism is described. This method has been applied to anaerobically growing cultures of Zymomonas mobilis and of a respiratory-deficient ("petite") mutant of Saccharomyces cerevisiae (strain YFa). The Michaelian kinetics recorded with both organisms were apparently related to glucose transport. With Z. mobilis, it was found that, in the range of glucose concentrations at which this organism was growing exponentially, cell activity was limited by the maximal rate of the catabolic enzymes; at lower concentrations, glucose transport was the rate controlling step. The metabolic activity of yeast always depended on external glucose concentration; when this was lowered under a threshold, a change of kinetics took place. The microcalorimetric method described seems to be widely applicable to kinetic studies of the permeation of metabolizable substrates in microorganisms. PMID:5650082

  1. Microcalorimetric Study of Glucose Permeation in Microbial Cells1

    Science.gov (United States)

    Belaich, Jean-Pierre; Senez, Jacques C.; Murgier, Maryse

    1968-01-01

    A microcalorimetric method for measuring the influence of extracellular glucose concentration on the rate of catabolism is described. This method has been applied to anaerobically growing cultures of Zymomonas mobilis and of a respiratory-deficient (“petite”) mutant of Saccharomyces cerevisiae (strain YFa). The Michaelian kinetics recorded with both organisms were apparently related to glucose transport. With Z. mobilis, it was found that, in the range of glucose concentrations at which this organism was growing exponentially, cell activity was limited by the maximal rate of the catabolic enzymes; at lower concentrations, glucose transport was the rate controlling step. The metabolic activity of yeast always depended on external glucose concentration; when this was lowered under a threshold, a change of kinetics took place. The microcalorimetric method described seems to be widely applicable to kinetic studies of the permeation of metabolizable substrates in microorganisms. PMID:5650082

  2. Insulin-like growth factor-I correlates more closely than growth hormone with insulin resistance and glucose intolerance in patients with acromegaly.

    Science.gov (United States)

    Niculescu, Dan; Purice, Mariana; Coculescu, Mihail

    2013-06-01

    In normal subjects growth hormone (GH) and insulin-like growth factor-I (IGF-I) have opposing effects on glucose metabolism. Active acromegaly is associated with insulin resistance (IR) and glucose intolerance although both GH and IGF-I are elevated. Our objective was to compare whether GH or IGF-I correlates more closely with IR and glucose intolerance in acromegaly. Basal serum IGF-I and GH, glucose and insulin during an oral glucose tolerance test were measured in 70 normoglycemic and 44 hyperglycemic acromegalic patients (21 impaired fasting glucose, 11 impaired glucose tolerance and 12 diabetes mellitus) according to American Diabetes Association criteria. 55 patients were assessed before any treatment for acromegaly and 59 after surgery and/or radiotherapy (15 patients had normal IGF-I after treatment). Patients treated with somatostatin analogs, GH-receptor antagonists or antidiabetic drugs were excluded. IR was assessed by various basal and stimulated indices. Homeostatic Model Assessment 2-Insulin Resistance (HOMA2-IR) index correlated more closely with IGF-I (r = 0.65, p < 0.0001) than nadir (r = 0.23, p = 0.008) or random GH (r = 0.26, p = 0.002). HOMA2-IR correlated better with IGF-I than nadir or random GH also in normoglycemic (n = 70; r = 0.74, p < 0.0001 vs. r = 0.36, p = 0.001 vs. r = 0.39, p < 0.001) and hyperglycemic patients (n = 44; r = 0.54, p = 0.0002 vs. r = 0.09, p = 0.4 vs. r = 0.14, p = 0.26). In multivariate logistic regression analysis IGF-I but not GH was a significant risk factor for glucose intolerance after adjusting for age, sex, weight and acromegaly duration (OR = 1.56, p = 0.01). In acromegaly IGF-I correlates more closely than GH with IR. IGF-I levels but not GH are associated with glucose intolerance. PMID:22562529

  3. Quantitative kinetics of renal glucose metabolism by the isotope dilution method in the unanesthetized sheep

    International Nuclear Information System (INIS)

    Renal glucose production and utilization rates in normal fed and fasted sheep were determined by the measurements of renal blood flow and arteriovenous 14C-glucose and glucose concentration differences using the method of primed continuous infusion of u-14C-glucose. At the same time total body glucose turnover rate was measured, and the contribution of renal glucose production to glucose requirement in the whole animal was quantitatively estimated. The renal blood flow for fed and fasted sheep were 20 +- 1 and 20 +- 3 ml/min/kg, respectively. No significant difference in the renal blood flow existed between the groups. The total body glucose turnover rate in fasted sheep (1.68 +- 0.20 mg/min/kg) was significantly lowered (P < 0.01) than that of fed sheep (2.20 +- 0.13 mg/min/kg). The renal glucose production rate in fed sheep was 0.47 +- 0.05 mg/min/kg and this rate accounted for about 21.4% of the glucose turnover rate. The renal glucose production rate in fasted sheep decreased to about 45% of that in fed sheep. However, the renal glucose utilization rate was similar in fed (0.26 +- 0.04 mg/min/kg) and fasted sheep (0.27 +- 0.04 mg/min/kg). Net renal glucose production rate in fed sheep, which was measured by the method of arteriovenous glucose concentration differences, was 0.22 +- 0.05 mg/min/kg, but that in fasted sheep was a negative value. These results suggest that the kidney of ruminant seems to produce a significant amount of glucose anproduce a significant amount of glucose and to utilize it simultaneously with production. (author)

  4. Amperometric glucose biosensor utilizing FAD-dependent glucose dehydrogenase immobilized on nanocomposite electrode.

    Science.gov (United States)

    Monošík, Rastislav; Stre?anský, Miroslav; Lušpai, Karol; Magdolen, Peter; Šturdík, Ernest

    2012-04-01

    Amperometric glucose biosensors utilizing commercially available FAD-dependent glucose dehydrogenases from two strains of Aspergillus species are described. Enzymes were immobilized on nanocomposite electrode consisting of multi-walled carbon nanotubes by entrapment between chitosan layers. Unlike the common glucose oxidase based biosensor, the presented biosensors appeared to be O(2)-independent. The optimal amount of enzymes, working potential and pH value of working media of the glucose biosensors were determined. The biosensor utilizing enzyme isolated from Aspergillus sp. showed linearity over the range from 50 to 960 ?M and from 70 to 620 ?M for enzyme from Aspergillus oryzae. The detection limits were 4.45 ?M and 4.15 ?M, respectively. The time of response was found to be 60 s. The biosensors showed excellent operational stability - no loss of sensitivity after 100 consecutive measurements and after the storage for 4 weeks at 4 °C in phosphate buffer solution. When biosensors were held in a dessicator at room temperature without use, they kept the same response ability at least after 6 months. Finally, the results obtained from measurements of beverages and wine samples were compared with those obtained with the enzymatic-spectrophotometric and standard HPLC methods, respectively. Good correlation between results in case of analysis of real samples and good analytical performance of presented glucose biosensor allows to use presented concept for mass production and commercial use. PMID:22418262

  5. Impaired fasting glucose individuals: their response to oral glucose challenge

    International Nuclear Information System (INIS)

    To determine the frequency of Impaired Fasting Glucose (IFG) individuals in symptom free adults and their 2-h PG (two-hour plasma glucose) concentrations in standard Oral Glucose Tolerance Test (OGTT) with 75-g glucose. Fasting plasma glucose (FPG) of 859 symptom free adults was checked. Of them, 344(40%) were found to have IFG, who were subjected to standard OGTT with 75-g glucose and their 2-h PG results were recorded. Frequency distribution of FPG of 859 symptom free adults showed, 455(53%) were Normal Fasting Glucose (NFG 7.0 mmol/l). The difference in frequency of three groups of FPG was statistically significant (p<0.0001). Of 344 IFG individuals, who were subjected to standard OGTT, 182(53%) had Normal Glucose Tolerance (NGT), 127(37%) were Impaired Glucose Tolerance (IGT) and 35(10%) were diabetics. The difference in frequency of the three groups was statistically significant (p<0.0001). A significantly large number of asymptomatic adults are suffering from IFG in our set up. When IFG individuals are subjected to 75-g OGTT, their 2-h PG results showed about one third have IGT and also a significant number of IFG individuals are found to be patients of diabetes. (author)

  6. Electronic devices for analog signal processing

    CERN Document Server

    Rybin, Yu K

    2012-01-01

    Electronic Devices for Analog Signal Processing is intended for engineers and post graduates and considers electronic devices applied to process analog signals in instrument making, automation, measurements, and other branches of technology. They perform various transformations of electrical signals: scaling, integration, logarithming, etc. The need in their deeper study is caused, on the one hand, by the extension of the forms of the input signal and increasing accuracy and performance of such devices, and on the other hand, new devices constantly emerge and are already widely used in practice, but no information about them are written in books on electronics. The basic approach of presenting the material in Electronic Devices for Analog Signal Processing can be formulated as follows: the study with help from self-education. While divided into seven chapters, each chapter contains theoretical material, examples of practical problems, questions and tests. The most difficult questions are marked by a diamon...

  7. An Integrated Glucose Sensor with an All-Solid-State Sodium Ion-Selective Electrode for a Minimally Invasive Glucose Monitoring System

    Directory of Open Access Journals (Sweden)

    Junko Kojima

    2015-06-01

    Full Text Available We developed a minimally invasive glucose monitoring system that uses a microneedle to permeate the skin surface and a small hydrogel to accumulate interstitial fluid glucose. The measurement of glucose and sodium ion levels in the hydrogel is required for estimating glucose levels in blood; therefore, we developed a small, enzyme-fixed glucose sensor with a high-selectivity, all-solid-state, sodium ion-selective electrode (ISE integrated into its design. The glucose sensor immobilized glucose oxidase showed a good correlation between the glucose levels in the hydrogels and the reference glucose levels (r > 0.99, and exhibited a good precision (coefficient of variation = 2.9%, 0.6 mg/dL. In the design of the sodium ISEs, we used the insertion material Na0.33MnO2 as the inner contact layer and DD16C5 exhibiting high Na+/K+ selectivity as the ionophore. The developed sodium ISE exhibited high selectivity (\\( \\log \\,k^{pot}_{Na,K} = -2.8\\ and good potential stability. The sodium ISE could measure 0.4 mM (10?3.4 M sodium ion levels in the hydrogels containing 268 mM (10?0.57 M KCl. The small integrated sensor (? < 10 mm detected glucose and sodium ions in hydrogels simultaneously within 1 min, and it exhibited sufficient performance for use as a minimally invasive glucose monitoring system.

  8. Detailed investigation of heat flux measurements made in a standard propane-air fire-certification burner compared to levels derived from a low-temperature analog burner

    OpenAIRE

    Abu Talib, AR; Neely, AJ; Ireland, PT; Mullender, AJ

    2005-01-01

    This paper presents detailed heat flux measurements on a flat plate subjected to the ISO2685 [The International Organization for Standardization (ISO), 1992, "Aircraft - Environmental Conditions and Test Procedures for Airborne Equipment - Resistance to Fire in Designated Fire Zones," ISO2685:1992(E)] standard, propane fueled burner used throughout the industry in aero-engine fire-certification. The authors have developed a custom-built heat transfer gauge to measure the heat flux from the bu...

  9. Continuous glucose monitoring in interstitial subcutaneous adipose tissue and skeletal muscle reflects excursions in cerebral cortex

    DEFF Research Database (Denmark)

    Nielsen, Jannik Kruse; Djurhuus, Christian Born

    2005-01-01

    Continuous glucose monitoring (CGM) is being explored using several types of glucose sensors. Some are designed for subcutaneous adipose tissue. It is important to determine to which extent these glucose fluctuations in different tissues reflect changes taking place in the central nervous system, where glucose sensing is thought to occur. We studied the ability of subcutaneous adipose interstitial fluid measurements to parallel glucose propagations in blood, muscle, and central nervous system (CNS) during hyper- and hypoglycemia. A subcutaneous CGM system was applied in the CNS, subcutaneous adipose tissue, and skeletal muscle of nine Vietnamese potbellied pigs, and data were compared with frequent sampling in blood. Alterations in glucose levels were induced with intravenous glucose and insulin. During hyperglycemia, no difference was detected in delay between blood and interstitial glucose levels in subcutaneous adipose tissue (18.0 +/- 0.8 min), muscle (18.0 +/- 0.9 min), and CNS (20.3 +/- 1.2 min), respectively. During hypoglycemia, we found no time difference between interstitial parameters in the three tissues. However, the amplitude of glucose changes varied considerably, with a smaller magnitude of glucose change taking place in the brain. The timing of glucose excursions in subcutaneous adipose tissue and muscle reflect excursions in CNS. The reduced magnitude of glucose excursions in the brain suggests that different mechanisms of glucose transport are operative in CNS compared with subcutaneous adipose tissue and muscle.

  10. Evidence that downregulation of hexose transport limits intracellular glucose in 3T3-L1 fibroblasts

    International Nuclear Information System (INIS)

    Measurements of initial glucose entry rate and intracellular glucose concentration in cultured cells are difficult because of rapid transport relative to intracellular volume and a substantial extracellular space from which glucose cannot be completely removed by quick exchanges of medium. In 3T3-L1 cells, we obtained good estimates of initial entry of [14C]methylglucose and D-[14C]glucose with (1) L-[3H]glucose as an extracellular marker together with the [14C]glucose or [14C]methylglucose in the substrate mixture, (2) sampling times as short as 2 s, (3) ice-cold phloretin-containing medium to stop uptake and rinse away the extracellular label, and (4) nonlinear regression of time courses. Methylglucose equilibrated in two phases--the first with a half-time of 1.7 s and the second with a half-time of 23 s; it eventually equilibrated in an intracellular space of 8 microliters/mg protein. Entry of glucose remained almost linear for 10 s, making its transport kinetics easier to study (Km = 5.7 mM, Vmax = 590 nmol.s-1.ml-1 cell water). Steady-state intracellular glucose concentration was 75-90% of extracellular glucose concentration. Cells grown in a high-glucose medium (24 mM) exhibited a 67% reduction of glucose-transport activity and a 50% reduction of steady-state ratio of intracellular glucose to extracellular glucose

  11. Regional differences in adipocyte lactate production from glucose

    International Nuclear Information System (INIS)

    Having shown that lactate is an important product of glucose metabolism by rat epididymal adipocytes, the authors investigated possible regional differences in adipocyte lactate production and the role of the animals' nutritional state and stage of development. [U-14C]glucose metabolism, lactate production, and response to insulin were measured in fat cells isolated from four adipose regions from young lean and older fatter rats, killed either in the fed state or after fasting for 48 h. In the absence of insulin, mesenteric fat cells from either age group metabolized significantly more glucose per cell and converted more glucose to lactate than cells from other depots, regardless of nutritional state. Adipocytes from fasted lean rats showed a significant increase in the relative glucose conversion to lactate in all depots when compared with cells from fed lean rats. Fasting of older fatter rats, however, had limited effects on the relative adipocyte glucose conversion to lactate since lactate production was already high. Mesenteric fat cells had the lowest relative response to insulin, possibly due to the high basal rate of glucose metabolism. These findings indicate that differences exist among adipose regions in the rates of glucose metabolism, lactate production and response to insulin. The anatomical location of the mesenteric adipose depot, coupled with a high metabolic rate and blood perfusion, suggests that mesenteric adipocytes may provide a unique esenteric adipocytes may provide a unique and more direct contribution of metabolic substrates for hepatic metabolism than adipocytes from other depots

  12. High glucose protects embryonic cardiac cells against simulated ischemia.

    Science.gov (United States)

    Malliopoulou, Vassiliki; Xinaris, Christodoulos; Mourouzis, Iordanis; Cokkinos, Alexandros D; Katsilambros, Nikolaos; Pantos, Constantinos; Kardami, Elissavet; Cokkinos, Dennis V

    2006-03-01

    In the present study we investigated whether acute glucose administration could be protective against hypoxic stress. H9c2 cells were exposed to either 4.5 mM or 22 mM of glucose for 15,min and then were submitted to simulated ischemia. Cell death was microscopically assessed by combined staining with propidium iodide (PI) and Hoeschst 33358. Intracellular content of glucose was measured by enzymatic analysis. Clucose content of H9c2 cells was 48.24+/- 7.94 micromol/L in the 22 mM vs 23.86+/- 4.8 micromol/L in the 4.5 mM group (p high glucose (p glucose. After hypoxia, in the 22 mM group, cell death was found to be 17.36+/- 2.66% vs 38.2+/- 5.4% in the 4.5 mM group (p high glucose (13.4+/- 1.7% cell death in 22 mM vs 27.5+/- 5.5% in 4.5 mM, p high glucose protects H9c2 cells against hypoxia. Although this protective effect is associated with translocation of PKCepsilon and increased glucose uptake, it was abrogated only by inhibition of glycolysis. PMID:16541202

  13. Discrete Calculus by Analogy

    CERN Document Server

    Izadi, F A; Bagirov, G

    2009-01-01

    With its origins stretching back several centuries, discrete calculus is now an increasingly central methodology for many problems related to discrete systems and algorithms. The topics covered here usually arise in many branches of science and technology, especially in discrete mathematics, numerical analysis, statistics and probability theory as well as in electrical engineering, but our viewpoint here is that these topics belong to a much more general realm of mathematics; namely calculus and differential equations because of the remarkable analogy of the subject to this branch of mathemati

  14. Deuterated prostaglandin analogs

    International Nuclear Information System (INIS)

    The preparation of deuterated prostaglandin analogs which are superior to the natural compounds regarding their pharmacological activity is described. They can be used as antihypertensive, antihtrombogenic and antifertile agent, furthermore as antineoplastic agent, bronchodilators or bronchoconstricters. Besides the type of compound, 9?, 13?-bisdeuterio-9?, 11?, 15?-trihydroxy-13-trans-prostenic acid, 9?, 13?-bisdeuterio-9?, 11?, 15?-trihydroxy-5-cis, 13-trans-prostadiene acid and 15?-deuterio-9?, 11?, 13?-trihydroxy-5 cis-13-trans-prostadiene acid are claimed, i.e. the preparation of each compound. Prescriptions for pharmaceutic preparations are described. (UWI)

  15. Stable-label intravenous glucose tolerance test minimal model

    International Nuclear Information System (INIS)

    The minimal model approach to estimating insulin sensitivity (Sl) and glucose effectiveness in promoting its own disposition at basal insulin (SG) is a powerful tool that has been underutilized given its potential applications. In part, this has been due to its inability to separate insulin and glucose effects on peripheral uptake from their effects on hepatic glucose inflow. Prior enhancements, with radiotracer labeling of the dosage, permit this separation but are unsuitable for use in pregnancy and childhood. In this study, we labeled the intravenous glucose tolerance test (IVGTT) dosage with [6,6-2H2]glucose, [2-2H]glucose, or both stable isotopically labeled glucose tracers and modeled glucose kinetics in six postabsorptive, nonobese adults. As previously found with the radiotracer model, the tracer-estimated S*l derived from the stable-label IVGTT was greater than Sl in each case except one, and the tracer-estimated SG* was less than SG in each instance. More importantly, however, the stable-label IVGTT estimated each parameter with an average precision of +/- 5% (range 3-9%) compared to average precisions of +/- 74% (range 7-309%) for SG and +/- 22% (range 3-72%) for Sl. In addition, because of the different metabolic fates of the two deuterated tracers, there were minor differences in basal insulin-derived measures of glucose effectiveness, but these differences were negligible for parameters describing insulin-stimulated procemeters describing insulin-stimulated processes. In conclusion, the stable-label IVGTT is a simple, highly precise means of assessing insulin sensitivity and glucose effectiveness at basal insulin that can be used to measure these parameters in individuals of all ages, including children and pregnant women

  16. Epigenome-wide association study of fasting measures of glucose, insulin, and HOMA-IR in the Genetics of Lipid Lowering Drugs and Diet Network study.

    Science.gov (United States)

    Hidalgo, Bertha; Irvin, M Ryan; Sha, Jin; Zhi, Degui; Aslibekyan, Stella; Absher, Devin; Tiwari, Hemant K; Kabagambe, Edmond K; Ordovas, Jose M; Arnett, Donna K

    2014-02-01

    Known genetic susceptibility loci for type 2 diabetes (T2D) explain only a small proportion of heritable T2D risk. We hypothesize that DNA methylation patterns may contribute to variation in diabetes-related risk factors, and this epigenetic variation across the genome can contribute to the missing heritability in T2D and related metabolic traits. We conducted an epigenome-wide association study for fasting glucose, insulin, and homeostasis model assessment of insulin resistance (HOMA-IR) among 837 nondiabetic participants in the Genetics of Lipid Lowering Drugs and Diet Network study, divided into discovery (N = 544) and replication (N = 293) stages. Cytosine guanine dinucleotide (CpG) methylation at ?470,000 CpG sites was assayed in CD4(+) T cells using the Illumina Infinium HumanMethylation 450 Beadchip. We fit a mixed model with the methylation status of each CpG as the dependent variable, adjusting for age, sex, study site, and T-cell purity as fixed-effects and family structure as a random-effect. A Bonferroni corrected P value of 1.1 × 10(-7) was considered significant in the discovery stage. Significant associations were tested in the replication stage using identical models. Methylation of a CpG site in ABCG1 on chromosome 21 was significantly associated with insulin (P = 1.83 × 10(-7)) and HOMA-IR (P = 1.60 × 10(-9)). Another site in the same gene was significant for HOMA-IR and of borderline significance for insulin (P = 1.29 × 10(-7) and P = 3.36 × 10(-6), respectively). Associations with the top two signals replicated for insulin and HOMA-IR (P = 5.75 × 10(-3) and P = 3.35 × 10(-2), respectively). Our findings suggest that methylation of a CpG site within ABCG1 is associated with fasting insulin and merits further evaluation as a novel disease risk marker. PMID:24170695

  17. Insulin Induces an Increase in Cytosolic Glucose Levels in 3T3-L1 Cells with Inhibited Glycogen Synthase Activation

    Directory of Open Access Journals (Sweden)

    Helena H. Chowdhury

    2014-10-01

    Full Text Available Glucose is an important source of energy for mammalian cells and enters the cytosol via glucose transporters. It has been thought for a long time that glucose entering the cytosol is swiftly phosphorylated in most cell types; hence the levels of free glucose are very low, beyond the detection level. However, the introduction of new fluorescence resonance energy transfer-based glucose nanosensors has made it possible to measure intracellular glucose more accurately. Here, we used the fluorescent indicator protein (FLIPglu-600µ to monitor cytosolic glucose dynamics in mouse 3T3-L1 cells in which glucose utilization for glycogen synthesis was inhibited. The results show that cells exhibit a low resting cytosolic glucose concentration. However, in cells with inhibited glycogen synthase activation, insulin induced a robust increase in cytosolic free glucose. The insulin-induced increase in cytosolic glucose in these cells is due to an imbalance between the glucose transported into the cytosol and the use of glucose in the cytosol. In untreated cells with sensitive glycogen synthase activation, insulin stimulation did not result in a change in the cytosolic glucose level. This is the first report of dynamic measurements of cytosolic glucose levels in cells devoid of the glycogen synthesis pathway.

  18. ?-adrenergic regulation of glucose transporters

    OpenAIRE

    Dallner, Olof

    2008-01-01

    The transport of glucose across the plasma membrane is a fundamental mechanism to provide cells with its basic requirements for energy yielding processes. It is also vital for clearing glucose from blood into tissues, a process normally stimulated by the hormone insulin in mammals. The sympathetic nervous system, normally activated during stress, also regulates glucose transport. The sympathetic neurotransmitter noradrenaline, acts on the family of adrenergic receptors (ARs). An important sub...

  19. Challenges & Countermeasures in Optical Noninvasive Blood Glucose Detection

    Directory of Open Access Journals (Sweden)

    MD KOUSHIK CHOWDHURY

    2013-01-01

    Full Text Available The aim of this paper is to discuss important issues for design and development of noninvasive blood glucometer. Noninvasive blood glucose monitoring could improve life quality of diabetes patients, enabling a better regulation of hyper and hypoglycemia conditions. Research to develop noninvasive glucose sensing technology is driven by the promise to provide in vivo glucose concentrations without pain, cost, and inconvenience of test strip meters. The optical approaches have brought exciting advances to this field. Till date several methods have been proposed for non invasive measurement of glucose level, present paper discusses their principle advantages and limitations. Most of these criteria center on selectivity of the analytical measurement, signal to noise ratio (SNR of the instrumentation, physical and chemical properties of the measurement site, and robustness of the calibration model.

  20. The relationship between gluconeogenic substrate supply and glucose production in humans

    International Nuclear Information System (INIS)

    The relationship between gluconeogenic precursor supply and glucose production has been investigated in 14-h and 86-h fasted humans. In protocols 1 and 2 [6,6-2H]glucose and [15N2]urea were infused to measure glucose and urea production rates (Ra) in response to infusions of glycerol and alanine. In protocol 3 first [15N]alanine, [3-13C]lactate, and [6,6-2H]glucose were infused before and during administration of dichloroacetate (DCA) to determine the response of glucose Ra to decreased fluxes of pyruvate, alanine, and lactate, then alanine was infused with DCA and glucose Ra measured. After a 14-h fast, neither alanine nor glycerol increased glucose Ra. Basal glucose Ra decreased by one-third after 86 h of fasting, yet glycerol and alanine infusions had no effect on glucose Ra. Glycerol always reduced urea Ra (P less than 0.05), suggesting that glycerol competitively inhibited gluconeogenesis from amino acids. DCA decreased the fluxes of pyruvate, alanine (P less than 0.01), and glucose Ra (P less than 0.01), which was prevented by alanine infusion. These findings suggest that (1) the reduction in glucose Ra after an 86-h fast is not because of a shortage of gluconeogenic substrate; (2) nonetheless, the importance of precursor supply to maintain basal glucose Ra is confirmed by the response to DCA; (3) an excess of one gluconeogenic substrate inhibits gluconeogenesis from others

  1. Effect of repaglinide on endothelial dysfunction during a glucose tolerance test in subjects with impaired glucose tolerance

    Directory of Open Access Journals (Sweden)

    Wascher Thomas C

    2006-04-01

    Full Text Available Abstract Background Impaired glucose tolerance (IGT is associated with increased cardiovascular risk. The pathophysiological mechanisms linking post-challenge hyperglycemia to accelerated atherosclerosis, however remain to be elucidated. Methods A prospective, open, randomised, cross-over study was performed to investigate the effect of 2 mg repaglinide on hyperglycemia and endothelial function during an oral glucose tolerance test (75 g glucose in 12 subjects with diagnosed IGT. Blood samples for determination of plasma glucose were drawn fasting, 1 and 2 hours after glucose ingestion. Endothelial function was assessed by measuring flow-mediated dilatation (FMD of the brachial artery with high-resolution ultrasound. Results Administration of repaglinide resulted in a significant reduction of plasma glucose at 2 hours (172.8+/-48.4 vs. 138.3+/-41.2 mg/dl; p Conclusion In subjects with IGT, the endothelial dysfunction observed after a glucose challenge is related to the extent of hyperglycemia. Reduction of hyperglycemia by repaglinide reduces endothelial dysfunction in a glucose dependent manner.

  2. Glucose metabolism in ischemic myocardium

    International Nuclear Information System (INIS)

    We determined the myocardial metabolic rate for glucose (MMRGlc) in the ischemic or infarcted myocardium using 18-F-fluorodeoxyglucose (18-FDG) with positron emission tomography (PET), and studied energy metabolism in the ischemic myocardium. In some cases, we compared glucose metabolism images by 18-FDG with myocardial blood flow images using 15-oxygen water. Two normal subjects, seven patients with myocardial infarction and four patients with angina pectoris were studied. Coronary angiography was performed within two weeks before or after the PET study to detect ischemic areas. PET studies were performed for patients who did not eat for 5 to 6 hours after breakfast. Cannulation was performed in the pedal artery to measure free fatty acid, blood sugar, and insulin. After recording the transmission scan for subsequent correction of photon attenuation, blood pool images were recorded for two min. after the inhalation of carbon monoxide (oxygen-15) which labeled the red blood cells in vivo. After 20 min., oxygen-15 water (15 to 20 mCi) was injected for dynamic scans, and flow images were obtained. Thirty min. after this procedure, 18-FDG (5 to 6 mCi) was injected, and 60 min later, a static scan was performed and glucose metabolism images were obtained. Arterial blood sampling for the time activity curve of the tracer was performed at the same time. According to the method of Phelps et al, MMRGlc was calculated in each of the region of interest (ROI) which was located igion of interest (ROI) which was located in the left ventricular wall. MMRGlc obtained from each ROI was 0 to 17 mg/100 ml/min. In normal subjects MMRGlc was 0.4 to 7.3 mg/100 ml/min. In patients with myocardial infarction, it ranged from 3 to 5 mg/100 ml/min in the infarcted lesion. In patients with angina pectoris and subendocardial infarction, MMRGlc was 7 to 17 mg/100 ml/min in the ischemic lesion. In this lesion, myocardial blood flow was relatively low by oxygen-15 imagings (so-called mismatch). (J.P.N.)

  3. Detecting analogical resemblance without retrieving the source analogy.

    Science.gov (United States)

    Kostic, Bogdan; Cleary, Anne M; Severin, Kaye; Miller, Samuel W

    2010-06-01

    We examined whether people can detect analogical resemblance to an earlier experimental episode without being able to recall the experimental source of the analogical resemblance. We used four-word analogies (e.g., robin-nest/beaver-dam), in a variation of the recognition-without-cued-recall method (Cleary, 2004). Participants studied word pairs (e.g., robin-nest) and were shown new word pairs at test, half of which analogically related to studied word pairs (e.g., beaver-dam) and half of which did not. For each test pair, participants first attempted to recall an analogically similar pair from the study list. Then, regardless of whether successful recall occurred, participants were prompted to rate the familiarity of the test pair, which was said to indicate the likelihood that a pair that was analogically similar to the test pair had been studied. Across three experiments, participants demonstrated an ability to detect analogical resemblance without recalling the source analogy. Findings are discussed in terms of their potential relevance to the study of analogical reasoning and insight, as well as to the study of familiarity and recognition memory. PMID:20551366

  4. Improvement in glucose biosensing response of electrochemically grown polypyrrole nanotubes by incorporating crosslinked glucose oxidase.

    Science.gov (United States)

    Palod, Pragya Agar; Singh, Vipul

    2015-10-01

    In this paper a novel enzymatic glucose biosensor has been reported in which platinum coated alumina membranes (Anodisc™s) have been employed as templates for the growth of polypyrrole (PPy) nanotube arrays using electrochemical polymerization. The PPy nanotube arrays were grown on Anodisc™s of pore diameter 100nm using potentiostatic electropolymerization. In order to optimize the polymerization time, immobilization of glucose oxidase (GOx) was first performed using physical adsorption followed by measuring its biosensing response which was examined amperometrically for increasing concentrations of glucose. In order to further improve the sensing performance of the biosensor fabricated for optimum polymerization duration, enzyme immobilization was carried out using cross-linking with glutaraldehyde and bovine serum albumin (BSA). Approximately six fold enhancement in the sensitivity was observed in the fabricated electrodes. The biosensors also showed a wide range of linear operation (0.2-13mM), limit of detection of 50?M glucose concentration, excellent selectivity for glucose, notable reliability for real sample detection and substantially improved shelf life. PMID:26117773

  5. Modelling, verification, and calibration of a photoacoustics based continuous non-invasive blood glucose monitoring system.

    Science.gov (United States)

    Pai, Praful P; Sanki, Pradyut K; Sarangi, Satyabrata; Banerjee, Swapna

    2015-06-01

    This paper examines the use of photoacoustic spectroscopy (PAS) at an excitation wavelength of 905 nm for making continuous non-invasive blood glucose measurements. The theoretical background of the measurement technique is verified through simulation. An apparatus is fabricated for performing photoacoustic measurements in vitro on glucose solutions and in vivo on human subjects. The amplitude of the photoacoustic signals measured from glucose solutions is observed to increase with the solution concentration, while photoacoustic amplitude obtained from in vivo measurements follows the blood glucose concentration of the subjects, indicating a direct proportionality between the two quantities. A linear calibration method is applied separately on measurements obtained from each individual in order to estimate the blood glucose concentration. The estimated glucose values are compared to reference glucose concentrations measured using a standard glucose meter. A plot of 196 measurement pairs taken over 30 normal subjects on a Clarke error grid gives a point distribution of 82.65% and 17.35% over zones A and B of the grid with a mean absolute relative deviation (MARD) of 11.78% and a mean absolute difference (MAD) of 15.27 mg/dl (0.85 mmol/l). The results obtained are better than or comparable to those obtained using photoacoustic spectroscopy based methods or other non-invasive measurement techniques available. The accuracy levels obtained are also comparable to commercially available continuous glucose monitoring systems. PMID:26133859

  6. Importance of the pre-analytical phase in blood glucose analysis.

    Science.gov (United States)

    Janssen, K; Delanghe, J

    2010-01-01

    Blood glucose levels are characterized by a relatively large intra-individual biological variability due to food intake, physical activity and the body's homeostatic response. Careful attention to the pre-analytical phase is essential to ensure accurate glucose measurements. Blood samples should be drawn in the morning after an overnight fast. Proper sample processing after blood collection is crucial. When fast separation of the cells is not possible, blood should be collected into a tube containing a glucose preservative. Glucose concentrations may also differ according to the blood sampling site (venous, arterial or capillary blood). Plasma and whole blood glucose values are not interchangeable. The International Federation of Clinical Chemistry and Laboratory Medicine recommends reporting the glucose concentration in plasma to avoid clinical misinterpretations irrespective of the sample type and method of measurement. Point-of-care testing (POCT) glucose meters are widely used by both health professionals and diabetic patients to monitor blood glucose levels. However, one should take into account that the reliability of POCT glucose measurements depends upon a variety of factors including underlying disease, patient drug regimens and interfering substances as well as instrument analytical performance and user proficiency. It is recommended to perform a laboratory blood glucose analysis if the POCT glucose value is in the critical hypoglycaemic or hyperglycaemic range. PMID:21128557

  7. Benfotiamine increases glucose oxidation and downregulates NADPH oxidase 4 expression in cultured human myotubes exposed to both normal and high glucose concentrations.

    Science.gov (United States)

    Fraser, D A; Hessvik, N P; Nikoli?, N; Aas, V; Hanssen, K F; Bøhn, S K; Thoresen, G H; Rustan, A C

    2012-07-01

    The aim of the present work was to study the effects of benfotiamine (S-benzoylthiamine O-monophosphate) on glucose and lipid metabolism and gene expression in differentiated human skeletal muscle cells (myotubes) incubated for 4 days under normal (5.5 mM glucose) and hyperglycemic (20 mM glucose) conditions. Myotubes established from lean, healthy volunteers were treated with benfotiamine for 4 days. Glucose and lipid metabolism were studied with labeled precursors. Gene expression was measured using real-time polymerase chain reaction (qPCR) and microarray technology. Benfotiamine significantly increased glucose oxidation under normoglycemic (35 and 49% increase at 100 and 200 ?M benfotiamine, respectively) as well as hyperglycemic conditions (70% increase at 200 ?M benfotiamine). Benfotiamine also increased glucose uptake. In comparison, thiamine (200 ?M) increased overall glucose metabolism but did not change glucose oxidation. In contrast to glucose, mitochondrial lipid oxidation and overall lipid metabolism were unchanged by benfotiamine. The expression of NADPH oxidase 4 (NOX4) was significantly downregulated by benfotiamine treatment under both normo- and hyperglycemic conditions. Gene set enrichment analysis (GSEA) showed that befotiamine increased peroxisomal lipid oxidation and organelle (mitochondrial) membrane function. In conclusion, benfotiamine increases mitochondrial glucose oxidation in myotubes and downregulates NOX4 expression. These findings may be of relevance to type 2 diabetes where reversal of reduced glucose oxidation and mitochondrial capacity is a desirable goal. PMID:21984258

  8. Numerical Modeling on Non-enzymatic, Potentiometric Glucose Sensor

    Scientific Electronic Library Online (English)

    M., Kanagasabapathy; G.N.K., Ramesh Bapu; Praveen, Lingac; R.M., Gnanamuthud.

    2012-07-01

    Full Text Available A novel, enzymeless electrochemical sensing mechanism for glucose based on potentiometric measurement was proposed using the mediator hexacyanoferrate. In this methodology, EMF of the cell exclusively depends on glucose concentration and independent on reference half-cell electrode potential or medi [...] ator concentration or any other interfering factors. Electrochemical as well as mathematical models were proposed. Numerical computations along with boundary conditions were evaluated for the proposed models, to reduce the deviation in the interpolated results. Molar ratio of mediator to glucose was correlated with EMF cell. Numerical simulations, Legendre polynomials and Lagrange coefficients iterations can be executed through computer programs.

  9. Multiple Access Analog Fountain Codes

    OpenAIRE

    Shirvanimoghaddam, Mahyar; Li, Yonghui; Vucetic, Branka

    2014-01-01

    In this paper, we propose a novel rateless multiple access scheme based on the recently proposed capacity-approaching analog fountain code (AFC). We show that the multiple access process will create an equivalent analog fountain code, referred to as the multiple access analog fountain code (MA-AFC), at the destination. Thus, the standard belief propagation (BP) decoder can be effectively used to jointly decode all the users. We further analyse the asymptotic performance of t...

  10. Producing and Recognizing Analogical Relations

    OpenAIRE

    Lipkens, Regina; Hayes, Steven C.

    2009-01-01

    Analogical reasoning is an important component of intelligent behavior, and a key test of any approach to human language and cognition. Only a limited amount of empirical work has been conducted from a behavior analytic point of view, most of that within Relational Frame Theory (RFT), which views analogy as a matter of deriving relations among relations. The present series of four studies expands previous work by exploring the applicability of this model of analogy to topography-based rather ...

  11. Beginning analog electronics through projects

    CERN Document Server

    Singmin, Andrew

    2001-01-01

    Analog electronics is the simplest way to start a fun, informative, learning program. Beginning Analog Electronics Through Projects, Second Edition was written with the needs of beginning hobbyists and students in mind. This revision of Andrew Singmin's popular Beginning Electronics Through Projects provides practical exercises, building techniques, and ideas for useful electronics projects. Additionally, it features new material on analog and digital electronics, and new projects for troubleshooting test equipment.Published in the tradition of Beginning Electronics Through Projects an

  12. ESD design for analog circuits

    CERN Document Server

    Vashchenko, Vladislav A

    2010-01-01

    This book is on high voltage and system level circuit design. It covers many challenging ESD topics related to analog circuit design for both ESD device and ESD circuits at the network level. Included is extensive discussion of analog design for DC-DC buck/boost converters, level shifters, digital-analog converters, high speed and precision power amplifiers, and system level cable specs for interface applications.

  13. Exercise training improves fasting glucose control

    OpenAIRE

    Lewis N; Norton K; Norton L

    2012-01-01

    Lynda Norton,1 Kevin Norton,2 Nicole Lewis21School of Medicine, Flinders University, Adelaide, Australia; 2School of Health Science, University of South Australia, Adelaide, AustraliaPurpose: Numerous studies have measured changes in fasting blood glucose (FBG) levels in response to physical activity (PA) interventions. While studies involving clinical populations such as type 2 diabetics typically report significant reductions, most others report no change in FBG. This study investigated cha...

  14. Coexpression of glucose transporters and glucokinase in Xenopus oocytes indicates that both glucose transport and phosphorylation determine glucose utilization.

    OpenAIRE

    Morita, H.; Yano, Y.; Niswender, K. D.; May, J. M.; Whitesell, R. R.; Wu, L.; Printz, R. L.; Granner, D. K.; Magnuson, M. A.; Powers, A. C.

    1994-01-01

    A Xenopus oocyte expression system was used to examine how glucose transporters (GLUT 2 and GLUT 3) and glucokinase (GK) activity affect glucose utilization. Uninjected oocytes and low rates of both glucose transport and phosphorylation; expression of GLUT 2 or GLUT 3 increased glucose phosphorylation approximately 20-fold by a low Km, endogenous hexokinase at glucose concentrations < or = 1 mM, but not at higher glucose concentrations. Coexpression of functional GK isoforms with GLUT 2 or 3 ...

  15. Effects of cinnamaldehyde on the glucose transport activity of GLUT1

    Science.gov (United States)

    Plaisier, Christina; Cok, Alexandra; Scott, Jordan; Opejin, Adeleye; Bushhouse, Kelsey T.; Sallie, Mathew; Louters, Larry L.

    2010-01-01

    There is accumulating evidence that cinnamon extracts contain components that enhance insulin action. However, little is know about the effects of cinnamon on non-insulin stimulated glucose uptake. Therefore, the effects of cinnamaldehyde on the glucose transport activity of GLUT1 in L929 fibroblast cells were examined under both basal conditions and conditions where glucose uptake is activated by glucose deprivation. The data reveal that cinnamaldehyde has a dual action on the glucose transport activity of GLUT1. Under basal conditions it stimulates glucose uptake and reaches a 3.5 fold maximum stimulation at 2.0 mM. However, cinnamaldehyde also inhibits the activation of glucose uptake by glucose deprivation in a dose dependent manner. Experiments with cinnamaldehyde analogs reveal that these activities are dependent on the ?,?-unsaturated aldehyde structural motif in cinnamaldehyde. The inhibitory, but not the stimulatory activity of cinnamaldehyde was maintained after a wash-recovery period. Pretreatment of cinnamaldehyde with thiol-containing compounds, such as ?-mercaptoethanol or cysteine, blocked the inhibitory activity of cinnamaldehyde. These results suggest that cinnamaldehyde inhibits the activation of GLUT1 by forming a covalent link to target cysteine residue/s. This dual activity of cinnamaldehyde on the transport activity of GLUT1 suggests that cinnamaldehye is not a major contributor to the anti-diabetic properties of cinnamon. PMID:20955755

  16. Glucose screening and tolerance tests during pregnancy

    Science.gov (United States)

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

  17. IDegAsp : a novel soluble insulin analogs combination

    DEFF Research Database (Denmark)

    Ma, Zhulin; Parkner, Tina

    2012-01-01

    INTRODUCTION: Current rapid- and long-acting insulin analogs cannot maintain their individual pharmacokinetic profile when they are co-formulated. IDegAsp , a novel soluble combination was developed with rapid-acting insulin aspart and a new-generation ultra-long-acting insulin, insulin degludec and was anticipated to offer clinical advantage over available premixed insulin suspensions. AREAS COVERED: We reviewed published data regarding pharmacological characters, clinical efficacy, safety, and tolerability of IDegAsp. Literature was searched through the electronic medical databases (PubMed, EMBASE, and Web of Knowledge) up to June 2012. EXPERT OPINION: Preliminary clinical data indicate that IDegAsp is a safe, well-tolerated insulin combination and provides a similar overall glycemic control to current insulin preparations with a reduced risk of hypoglycemia. IDegAsp might be a promising treatment option for patients with type 2 diabetes who need to improve control of postprandial glucose excursions and fasting glucose levels.

  18. Analogic fiber optic position sensor with nanometric resolution

    OpenAIRE

    Lamarque, Fre?de?ric; Prelle, Christine

    2002-01-01

    This paper describes a miniature analogic position sensor. This sensor is dedicated to high resolution displacement measurement (10 nm) between two positions on long range (few millimeters). The working principle of the sensor is presented as well as experimentation results.

  19. Factors Associated with Increases in Glucose Levels in the Perioperative Period in Non-Diabetic Patients

    Directory of Open Access Journals (Sweden)

    Manasee Sant

    2013-05-01

    Full Text Available Background: Blood glucose levels are elevated during the perioperative period as a result of the neuro-endocrine response to the stress of surgery. In nondiabetic patients, blood glucose levels are not a part of routine preoperative testing nor are they monitored during surgery or in the post anesthesia care unit (PACU. We measured blood glucose levels in nondiabetic patients during the perioperative period to identify how many patients had high glucose levels and what factors were associated with increases in blood glucose levels. Methods: This prospective observational study included two hundred and ninety five nondiabetic patients between the ages of 18 and 80 years, undergoing elective noncardiac surgery. Blood glucose levels were measured preoperatively and at frequent, predetermined intervals during surgery and in the PACU. Patient characteristics, surgical and anesthetic factors, and pain scores in the PACU were recorded, as were postoperative complications. Results: Forty nine percent (49% of the patients had maximum intraoperative glucose levels of 126 mg/dl or higher and fifty three percent (53% had maximum postoperative glucose levels of 126 mg/dl or higher. Preoperative glucose levels, family history of diabetes and amount of blood loss were statistically significantly associated with both max-intra-op and max-post-op glucose levels. Additionally, blood administration, surgery duration and race were significantly associated with max-intra-op glucose levels, while amount of intravenous fluids and sex were significantly associated with max-post-op glucose levels. Conclusion: A large number of nondiabetic patients in our study had maximum glucose levels >126 mg/dl in the perioperative period. Certain patient characteristics, as well as surgical/anesthetic factors, were associated with increases in the glucose levels. More studies are indicated to determine which patients may benefit from glucose monitoring in the perioperative period.

  20. Diagnosis of hypoglycaemia: effects of blood sample handling and evaluation of a glucose photometer in the low glucose range.

    Science.gov (United States)

    Elimam, A; Horal, M; Bergström, M; Marcus, C

    1997-05-01

    Hypoglycaemia is a dangerous condition. Rapid and reliable blood glucose measurements are necessary for the initiation of treatment to reduce the risk of neurological sequelae. The aim of this study was to compare a bedside glucose photometer (HemoCue) with three methods of handling blood glucose measurements in a routine chemistry laboratory and to estimate the reliability of glucose measurements in the low glucose range during controlled hypoglycaemia. Nine children underwent an arginine-insulin tolerance test as part of a growth hormone deficiency investigation. Only blood samples below 4.0 mmol l-1 were included (n = 35). Significant (0.3-1.0 mmol l-1) differences in blood glucose measurements were found, depending on the handling of the blood sample. The differences seem primarily to be due to glycolysis which occurred in spite of the addition of the glycolysis inhibitor NaF to the blood samples. Immediate centrifugation and analysis of the supernatant or immediate analysis with the HemoCue results in higher, and presumably more correct, values than routine procedures and permits a more accurate diagnosis of hypoglycaemia. PMID:9183485

  1. Serum glucose concentration and lipid profile in racing horses

    OpenAIRE

    S.A. Hasso; H. A. Al-Hadithy; R. M. Hameed

    2012-01-01

    The aim of the present work was to evaluate serum glucose concentration and lipid profile in racing horses in Iraq. Blood samples were collected from the jugular vein of 92 clinically healthy racing horses (males and females, Arabian and Cross bred), 2-8 years old at Equestrian Club, Baghdad. Investigations included serum measurements of glucose (sg) and lipid profile parameters; total cholesterol (TC), Triglyceride (TG), high density lipoprotein- cholesterol (HDL-C), low density lipoprotein-...

  2. Maternal arsenic exposure and impaired glucose tolerance during pregnancy

    OpenAIRE

    Zota, Ami R; HU, HOWARD; Ettinger, Adrienne S; Amarasiriwardena, Chitra J.; Hopkins, Marianne; Schwartz, Joel David; Robert O. Wright

    2009-01-01

    Background: Accumulating evidence has shown an increased risk of type 2 diabetes in general populations exposed to arsenic, but little is known about exposures during pregnancy and the association with gestational diabetes (GD). Objectives: We studied 532 women living proximate to the Tar Creek Superfund Site to investigate whether arsenic exposure is associated with impaired glucose tolerance during pregnancy. Methods: Blood glucose was measured between 24 and 28 weeks gestation after a 1-hr...

  3. Continuous Glucose Monitoring Systems: A Review

    OpenAIRE

    Sandeep Kumar Vashist

    2013-01-01

    There have been continuous advances in the field of glucose monitoring during the last four decades, which have led to the development of highly evolved blood glucose meters, non-invasive glucose monitoring (NGM) devices and continuous glucose monitoring systems (CGMS). Glucose monitoring is an integral part of diabetes management, and the maintenance of physiological blood glucose concentration is the only way for a diabetic to avoid life-threatening diabetic complications. CGMS have led to ...

  4. Current concepts in blood glucose monitoring

    OpenAIRE

    Khadilkar, Kranti Shreesh; Bandgar, Tushar; Shivane, Vyankatesh; Lila, Anurag; Shah, Nalini

    2013-01-01

    Blood glucose monitoring has evolved over the last century. The concept of adequate glycemic control and minimum glycemic variability requires an ideal, accurate and reliable glucose monitoring system. The search for an ideal blood glucose monitoring system still continues. This review explains the various blood glucose monitoring systems with special focus on the monitoring systems like self- monitored blood glucose (SMBG) and continuous glucose monitoring system (CGMS). It also focuses on t...

  5. Glucose Sensing Neurons in the Ventromedial Hypothalamus

    OpenAIRE

    Routh, Vanessa H.

    2010-01-01

    Neurons whose activity is regulated by glucose are found in a number of brain regions. Glucose-excited (GE) neurons increase while glucose-inhibited (GI) neurons decrease their action potential frequency as interstitial brain glucose levels increase. We hypothesize that these neurons evolved to sense and respond to severe energy deficit (e.g., fasting) that threatens the brains glucose supply. During modern times, they are also important for the restoration of blood glucose levels following i...

  6. Abnormalities of glucose metabolism in spontaneously hypertensive rats

    Directory of Open Access Journals (Sweden)

    L.M.F.B. Gouveia

    2000-11-01

    Full Text Available Abnormalities in glucose metabolism and insulin action are frequently detected in patients with essential hypertension. Spontaneously hypertensive rats (SHR have been used as an experimental model to understand this pathological condition. The objective of the present study was to assess glucose metabolism and insulin action in SHR and Wistar rats under fed and fasting conditions. Peripheral glucose utilization was estimated by kinetic studies with [6-³H]-glucose and gluconeogenetic activity was measured during continuous [14C]-bicarbonate infusion. Plasma glucose levels were higher in the SHR group. Plasma insulin levels in the fed state were higher in the SHR group (99.8 ± 6.5 µM than in the control group (70.4 ± 3.6 µM. Muscle glycogen content was reduced in SHR compared to control under the various experimental conditions. Peripheral glucose utilization was slightly lower in the SHR group in the fed state (8.72 ± 0.55 vs 9.52 ± 0.80 mg kg-1 min-1 in controls. Serum free fatty acid levels, hepatic glycogen levels, hepatic phosphoenolpyruvate carboxykinase activity and gluconeogenetic activity were similar in the two groups. The presence of hyperglycemia and hyperinsulinemia and the slightly reduced peripheral glucose utilization suggest the presence of resistance to the action of insulin in peripheral tissues of SHR. Hepatic gluconeogenesis does not seem to contribute to the metabolic alterations detected in these animals.

  7. Abnormalities of glucose metabolism in spontaneously hypertensive rats

    Scientific Electronic Library Online (English)

    L.M.F.B., Gouveia; I.C., Kettelhut; M.C., Foss.

    1357-13-01

    Full Text Available Abnormalities in glucose metabolism and insulin action are frequently detected in patients with essential hypertension. Spontaneously hypertensive rats (SHR) have been used as an experimental model to understand this pathological condition. The objective of the present study was to assess glucose me [...] tabolism and insulin action in SHR and Wistar rats under fed and fasting conditions. Peripheral glucose utilization was estimated by kinetic studies with [6-³H]-glucose and gluconeogenetic activity was measured during continuous [14C]-bicarbonate infusion. Plasma glucose levels were higher in the SHR group. Plasma insulin levels in the fed state were higher in the SHR group (99.8 ± 6.5 µM) than in the control group (70.4 ± 3.6 µM). Muscle glycogen content was reduced in SHR compared to control under the various experimental conditions. Peripheral glucose utilization was slightly lower in the SHR group in the fed state (8.72 ± 0.55 vs 9.52 ± 0.80 mg kg-1 min-1 in controls). Serum free fatty acid levels, hepatic glycogen levels, hepatic phosphoenolpyruvate carboxykinase activity and gluconeogenetic activity were similar in the two groups. The presence of hyperglycemia and hyperinsulinemia and the slightly reduced peripheral glucose utilization suggest the presence of resistance to the action of insulin in peripheral tissues of SHR. Hepatic gluconeogenesis does not seem to contribute to the metabolic alterations detected in these animals.

  8. In Vitro Evaluation of Fluorescence Glucose Biosensor Response

    Directory of Open Access Journals (Sweden)

    Mamdouh Aloraefy

    2014-07-01

    Full Text Available Rapid, accurate, and minimally-invasive glucose biosensors based on Förster Resonance Energy Transfer (FRET for glucose measurement have the potential to enhance diabetes control. However, a standard set of in vitro approaches for evaluating optical glucose biosensor response under controlled conditions would facilitate technological innovation and clinical translation. Towards this end, we have identified key characteristics and response test methods, fabricated FRET-based glucose biosensors, and characterized biosensor performance using these test methods. The biosensors were based on competitive binding between dextran and glucose to concanavalin A and incorporated long-wavelength fluorescence dye pairs. Testing characteristics included spectral response, linearity, sensitivity, limit of detection, kinetic response, reversibility, stability, precision, and accuracy. The biosensor demonstrated a fluorescence change of 45% in the presence of 400 mg/dL glucose, a mean absolute relative difference of less than 11%, a limit of detection of 25 mg/dL, a response time of 15 min, and a decay in fluorescence intensity of 72% over 30 days. The battery of tests presented here for objective, quantitative in vitro evaluation of FRET glucose biosensors performance have the potential to form the basis of future consensus standards. By implementing these test methods for a long-visible-wavelength biosensor, we were able to demonstrate strengths and weaknesses with a new level of thoroughness and rigor.

  9. Capillary versus venous bedside blood glucose estimations

    OpenAIRE

    Boyd, R.; Leigh, B.; Stuart, P.

    2005-01-01

    Objectives: To determine the mean difference and correlation between capillary and venous bedside glucose estimation in comparison to laboratory blood glucose analysis in emergency department (ED) patients.

  10. Involvement of multiple sodium ions in intestinal d-glucose transport.

    OpenAIRE

    Kaunitz, J. D.; Gunther, R.; Wright, E. M.

    1982-01-01

    Brush border membrane vesicles isolated from rabbit small intestine were used to measure the interactions between sodium and glucose transport with a rapid uptake technique. A plot of glucose uptake rate vs. increasing sodium concentration yielded a sigmoid curve. Hill analysis revealed a coefficient of 1.9 +/- 0.02 (+/- SEM), consistent with at least two sodium ions involved in glucose transport. Transport coupling was then measured directly with double-label experiments in which the uptakes...

  11. The Need for Continuous Blood Glucose Monitoring in the Intensive Care Unit

    OpenAIRE

    Weiss, Ram; Lazar, Isaac

    2007-01-01

    Insulin-based regimens decrease morbidity and mortality among critically ill patients by way of keeping glucose at tight control. Utilizing these regimens involves multiple measurements of glucose by way of finger pricking or through indwelling vascular catheters in order to adjust insulin doses. The limitations and risks of these methods of glucose monitoring are related to potential erroneous measurements, increased risk of infection, and a significant excess workload. An automated blood gl...

  12. Noninvasive glucose detection in human skin using wavelength modulated differential laser photothermal radiometry

    OpenAIRE

    Guo, Xinxin; Mandelis, Andreas; Zinman, Bernard

    2012-01-01

    Noninvasive glucose monitoring will greatly improve diabetes management. We applied Wavelength-Modulated Differential Laser Photothermal Radiometry (WM-DPTR) to noninvasive glucose measurements in human skin in vitro in the mid-infrared range. Glucose measurements in human blood serum diffused into a human skin sample (1 mm thickness from abdomen) in the physiological range (21-400 mg/dl) demonstrated high sensitivity and accuracy to meet wide clinical detection requirements. It was found tha...

  13. Evaluation of a continuous glucose monitoring system in cats with diabetes mellitus.

    OpenAIRE

    Ristic, JM; Herrtage, ME; Walti-Lauger, SM; Slater, LA; Church, DB; Davison, LJ; Catchpole, B.

    2005-01-01

    A continuous glucose monitoring system (CGMS) was evaluated in 14 cats with naturally occurring diabetes mellitus. The device measures interstitial fluid glucose continuously, by means of a sensor placed in the subcutaneous tissue. All cats tolerated the device well and a trace was obtained on 15/16 occasions. There was good correlation between the CGMS values and blood glucose concentration measured using a glucometer (r=0.932, P

  14. Natural analog studies: Licensing perspective

    Energy Technology Data Exchange (ETDEWEB)

    Bradbury, J.W. [Nuclear Regulatory Commission, Washington, DC (United States)

    1995-09-01

    This report describes the licensing perspective of the term {open_quotes}natural analog studies{close_quotes} as used in CFR Part 60. It describes the misunderstandings related to its definition which has become evident during discussions at the U.S Nuclear Regulatory Commission meetings and tries to clarify the appropriate applications of natural analog studies to aspects of repository site characterization.

  15. Conjecturing via Reconceived Classical Analogy

    Science.gov (United States)

    Lee, Kyeong-Hwa; Sriraman, Bharath

    2011-01-01

    Analogical reasoning is believed to be an efficient means of problem solving and construction of knowledge during the search for and the analysis of new mathematical objects. However, there is growing concern that despite everyday usage, learners are unable to transfer analogical reasoning to learning situations. This study aims at facilitating…

  16. Glutamine-dependent anapleurosis dictates glucose uptake and cell growth by regulating MondoA transcriptional activity.

    Science.gov (United States)

    Kaadige, Mohan R; Looper, Ryan E; Kamalanaadhan, Sadhaasivam; Ayer, Donald E

    2009-09-01

    Glucose and glutamine are abundant nutrients required for cell growth, yet how cells sense and adapt to changes in their levels is not well understood. The MondoA transcription factor forms a heterocomplex with its obligate partner Mlx to regulate approximately 75% of glucose-dependent transcription. By mediating glucose-induced activation of thioredoxin-interacting protein (TXNIP), MondoA:Mlx complexes directly repress glucose uptake. We show here that glutamine inhibits transcriptional activation of TXNIP by triggering the recruitment of a histone deacetylase-dependent corepressor to the amino terminus of MondoA. Therefore, in the presence of both glucose and glutamine, TXNIP expression is low, which favors glucose uptake and aerobic glycolysis; the Warburg effect. Consistent with MondoA functioning upstream of TXNIP, MondoA knockdown reduces TXNIP expression, elevates glucose uptake and stimulates cell proliferation. Although glutamine has many intracellular fates, a cell permeable analog of a tricarboxylic acid cycle (TCA) intermediate, alpha-ketoglutarate, also blocks the transcriptional activity of MondoA at the TXNIP promoter and stimulates glucose uptake. Together our data suggest that glutamine-dependent mitochondrial anapleurosis dictates glucose uptake and aerobic glycolysis by blocking MondoA:Mlx-dependent transcriptional activation of TXNIP. We propose that this previously unappreciated coordination between glutamine and glucose utilization defines a metabolic checkpoint that restricts cell growth when subthreshold levels of these essential nutrients are available. PMID:19706488

  17. Genetic variation in GIPR influences the glucose and insulin responses to an oral glucose challenge

    DEFF Research Database (Denmark)

    Saxena, Richa; Hivert, Marie-France

    2010-01-01

    Glucose levels 2 h after an oral glucose challenge are a clinical measure of glucose tolerance used in the diagnosis of type 2 diabetes. We report a meta-analysis of nine genome-wide association studies (n = 15,234 nondiabetic individuals) and a follow-up of 29 independent loci (n = 6,958-30,620). We identify variants at the GIPR locus associated with 2-h glucose level (rs10423928, beta (s.e.m.) = 0.09 (0.01) mmol/l per A allele, P = 2.0 x 10(-15)). The GIPR A-allele carriers also showed decreased insulin secretion (n = 22,492; insulinogenic index, P = 1.0 x 10(-17); ratio of insulin to glucose area under the curve, P = 1.3 x 10(-16)) and diminished incretin effect (n = 804; P = 4.3 x 10(-4)). We also identified variants at ADCY5 (rs2877716, P = 4.2 x 10(-16)), VPS13C (rs17271305, P = 4.1 x 10(-8)), GCKR (rs1260326, P = 7.1 x 10(-11)) and TCF7L2 (rs7903146, P = 4.2 x 10(-10)) associated with 2-h glucose. Of the three newly implicated loci (GIPR, ADCY5 and VPS13C), only ADCY5 was found to be associated with type 2 diabetes in collaborating studies (n = 35,869 cases, 89,798 controls, OR = 1.12, 95% CI 1.09-1.15, P = 4.8 x 10(-18)).

  18. Glucose metabolism of lactobacillus divergens

    International Nuclear Information System (INIS)

    The aim of this study was to compile an optimal growth and selective medium for Lactobacillus divergens and to determine the pathway by which it metabolised glucose. The optimum growth temperature is 25oC which is lower than that of most other lactobacilli. Citrate stimulates growth up to a concentration of 1% while acetate inhibits the organism at neutral pH, but it stimulates growth at pH 8.5 up to a concentration of 0.8%. MRS medium was therefore modified in order to obtain maximum growth of the organism. The acetate was omitted, sucrose was substituted for glucose and the pH was adjusted to 8.5. Sucrose was used, since a neutral pH is obtained after sterilisation of glucose in alkaline (pH ? 7.5) solution due to the degradation of glucose by the Maillard reaction. Various inhibitors and dyes were tested in order to formulate a selective medium. In the present study differently labelled glucose precursors were fermented by L. divergens and the fermentation products isolated by HPLC. The concentrations of acetate and formate were determined by comparison to a standard while the concentration of lactate and glucose was determined by enzymic assay. The radioactivity was determined by liquid scintillation counting and the positional labelling in lactate and acetate by chemical degradation. Fermentation of D-[U-14C]-glucose was included to correct for endogenous product dilution

  19. Optical analog transmission device

    International Nuclear Information System (INIS)

    The present invention concerns a device such as electro-optical conversion elements, optoelectric-electric elements and optical transmission channel, not undergoing deleterious effects on the efficiency of conversion and transmission due to temperature, and aging change. That is, a sine wave superposing means superposes, on a detector signal to be transmitted, a sine-wave signal having a predetermined amplitude and at a frequency lower than that of the detector signal. An optoelectric conversion means converts the electric signal as the signal of the sine-wave signal superposing means into an optical signal and outputs the same to an optical transmitting channel. The optoelectric conversion means converts the transmitted signal to an electric signal. A discriminating means discriminates the electric signal into a detector signal and a sine-wave signal. A calculating means calculates an optical transmitting efficiency of the transmitting channel based on the amplitude of the discriminated sine-wave signal. A processing means compensates an amplitude value of the detector signals discriminated by the discriminating means based on the optical transmission efficiency. As a result, an optical analog transmission device can be attained, which conducts optical transmission at a high accuracy without undergoing the defective effects of the optical transmission efficiency. (I.S.)

  20. Ingredients of a Casimir analog computer

    CERN Document Server

    Rodriguez, Alejandro W; Joannopoulos, John D; Johnson, Steven G

    2009-01-01

    We present the basic ingredients of a technique to compute quantum Casimir forces at micrometer scales using antenna measurements at tabletop, e.g. centimeter, scales, forming a type of analog computer for the Casimir force. This technique relies on a correspondence that we derive between the contour integration of the Casimir force in the complex frequency plane and the electromagnetic response of a physical dissipative medium in a finite, real frequency bandwidth.

  1. Electrical Analogy to an Atomic Force Microscope

    Directory of Open Access Journals (Sweden)

    O. Kucera

    2010-04-01

    Full Text Available Several applications of the atomic force microscopy (AFM, such as measurement of soft samples, manipulation with molecules, etc., require mechanical analysis of the AFM probe behavior. In this article we suggest the electrical circuit analogy to AFM cantilever tip motion. Well developed circuit theories in connection with fairly accessible software for circuit analysis make this alternative method easy to use for a wide community of AFM users.

  2. Regional cerebral glucose metabolism in patients with Parkinson's disease with or without dementia

    International Nuclear Information System (INIS)

    By means of positron emission tomography, the cerebral glucose metabolism in 5 patients with Parkinson's disease with dementia was compared with that in 9 patients without dementia, and that in 5 normal volunteers. The metabolic rates for glucose were measured by placing one hundred regions of interest. In the demented patients, cerebral glucose metabolism was diffusely decreased compared with that of the non-demented patients and the normal controls. The most significant decrease in glucose metabolism was observed in the angular gyrus (49.7% of the normal controls). The glucose metabolism in the cingulate, pre- and postcentral, occipital and subcortical regions was relatively spared (62.1 to 85.5% of the normal controls). In the patients without dementia, the glucose metabolism in each region was not significantly different from that in the normal controls. These results suggest that diffuse glucose hypometabolism in the cerebral cortex may correlate with that of patients with Parkinson's disease with dementia. (author)

  3. Analog/Digital System for Germanium Thermometer

    Science.gov (United States)

    Woodhouse, Christopher

    1988-01-01

    Electronic system containing analog and digital circuits makes high-precision, four-wire measurements of resistance of each germanium resistance thermometer (GRT) in array of devices, using alternating current (ac) of 1 micro-A. At end measurement interval, contents of negative register subtracted from positive one, resulting in very-narrow-band synchronous demodulation of carrier wave and suppression of out-of-band noise. Microprocessor free to perform other duties after measurement complete. Useful in noisy terrestrial environments encountered in factories.

  4. CNS Regulation of Glucose Homeostasis

    Science.gov (United States)

    2009-06-01

    The past decade has hosted a remarkable surge in research dedicated to the central control of homeostatic mechanisms. Evidence indicates that the brain, in particular the hypothalamus, directly senses hormones and nutrients to initiate behavioral and metabolic responses to control energy and nutrient homeostasis. Diabetes is chiefly characterized by hyperglycemia due to impaired glucose homeostatic regulation, and a primary therapeutic goal is to lower plasma glucose levels. As such, in this review, we highlight the role of the hypothalamus in the regulation of glucose homeostasis in particular and discuss the cellular and molecular mechanisms by which this neural pathway is orchestrated.

  5. Polarimetric glucose sensing in vitro: a high frequency approach

    Science.gov (United States)

    Pirnstill, Casey W.; Grunden, Daniel; Coté, Gerard L.

    2013-02-01

    Optical polarimetry as a method to monitor glucose levels in the aqueous humor has shown promise as a way to noninvasively ascertain blood glucose concentration. A major limiting factor to polarimetric approaches for glucose monitoring in the aqueous humor is time varying birefringence due to motion artifact. Here, we present a modulation approach for real-time polarimetry that is capable of glucose monitoring in vitro at optical modulation frequencies of tens of kHz and includes the DC-compensation in a single device. Such higher frequency modulation has the potential benefit of improving the signal-to-noise ratio of the system in the presence of motion artifacts. In this report we present a near real-time closed-loop single wavelength polarimeter capable of glucose sensing in vitro at an optical modulation frequency of 32 kHz. The single wavelength polarimetric setup and in vitro glucose measurements will be presented demonstrating the sensitivity and accuracy of the system. Our PID control system can reach stability in less than 10 ms which is fast enough to overcome motion artifact due to heart beat and respiration. The the system can predict the glucose concentration with a standard error of less than 18.5 mg/dL and a MARD of less than 6.65% over the physiologic glucose range of 0-600 mg/dL. Our results indicate that this optical modulation approach coupled with dual-wavelength polarimetry has the potential to improve the of the dual-wavelength approach for in vivo glucose detection applications.

  6. Closed-loop controlled noninvasive ultrasonic glucose sensing and insulin delivery

    Science.gov (United States)

    Park, Eun-Joo; Werner, Jacob; Jaiswal, Devina; Smith, Nadine Barrie

    2010-03-01

    To prevent complications in diabetes, the proper management of blood glucose levels is essential. Previously, ultrasonic transdermal methods using a light-weight cymbal transducer array has been studied for noninvasive methods of insulin delivery for Type-1 diabetes and glucose level monitoring. In this study, the ultrasound systems of insulin delivery and glucose sensing have been combined by a feedback controller. This study was designed to show the feasibility of the feedback controlled ultrasound system for the noninvasive glucose control. For perspective human application, in vivo experiments were performed on large animals that have a similar size to humans. Four in vivo experiments were performed using about 200 lbs pigs. The cymbal array of 3×3 pattern has been used for insulin delivery at 30 kHz with the spatial-peak temporal-peak intensity (Isptp) of 100 mW/cm2. For glucose sensing, a 2×2 array was operated at 20 kHz with Isptp = 100 mW/cm2. Based on the glucose level determined by biosensors after the ultrasound exposure, the ultrasound system for the insulin delivery was automatically operated. The glucose level of 115 mg/dl was set as a reference value for operating the insulin delivery system. For comparison, the glucose levels of blood samples collected from the ear vein were measured by a commercial glucose meter. Using the ultrasound system operated by the close-loop, feed-back controller, the glucose levels of four pigs were determined every 20 minutes and continuously controlled for 120 minutes. In comparison to the commercial glucose meter, the glucose levels determined by the biosensor were slightly higher. The results of in vivo experiments indicate the feasibility of the feedback controlled ultrasound system using the cymbal array for noninvasive glucose sensing and insulin delivery. Further studies on the extension of the glucose control will be continued for the effective method of glucose control.

  7. Phytanic acid stimulates glucose uptake in a model of skeletal muscles, the primary porcine myotubes

    DEFF Research Database (Denmark)

    Che, Brita Ngum; Oksbjerg, Niels

    2013-01-01

    ABSTRACT: BACKGROUND: Phytanic acid (PA) is a chlorophyll metabolite with potentials in regulating glucose metabolism, as it is a natural ligand of the peroxisome proliferator-activated receptor (PPAR) that is known to regulate hepatic glucose homeostasis. This study aimed to establish primary porcine myotubes as a model for measuring glucose uptake and glycogen synthesis, and to examine the impact of physiological amounts of PA on glucose uptake and glycogen synthesis either alone or in combination with insulin. METHODS: Porcine satellite cells were cultured into differentiated myotubes and tritiated 2-deoxyglucose (2-DOG) was used to measure glucose uptake, in relation to PA and 2-DOG exposure times and also in relation to PA and insulin concentrations. The MIXED procedure model of SAS was used for statistical analysis of data. RESULTS: PA increased glucose uptake by approximately 35%, and the presence of insulin further increased the uptake, but this further increase in uptake was non- additive and less pronounced at high insulin concentrations. There was no effect of PA alone on glycogen synthesis, while the insulin stimulation of glycogen was increased by 20% in the presence of PA. PA neither stimulated glucose uptake nor glycogen synthesis in insulin-resistant myotubes generated by excess glucose exposure. CONCLUSIONS: Primary porcine myotubes were established as a model of skeletal muscles for measuring glucose uptake and glycogen synthesis, and we showed that PA can play a role in stimulating glucose uptake at no or inadequate insulin concentrations.

  8. Towards a Wearable Non-invasive Blood Glucose Monitoring Device

    Science.gov (United States)

    Andrews, Joseph Thomas; Solanki, J.; Choudhary, Om P.; Chouksey, S.; Malvia, N.; Chaturvedi, P.; Sen, P.

    2012-05-01

    Every day, about 150 Million people worldwide face the problem of diabetic metabolic control. Both the hypo- and hyper- glycaemic conditions of patients have fatal consequences and warrant blood glucose monitoring at regular interval. Existing blood glucose monitors can be widely classified into three classes viz., invasive, minimally invasive, and noninvasive. Invasive monitoring requires small volume of blood and are inappropriate for continuous monitoring of blood glucose. Minimally invasive monitors analyze tissue fluid or extract few micro litre of blood only. Also the skin injury is minimal. On the other hand, noninvasive devices are painless and void of any skin injury. We use an indigenously developed polarization sensitive Optical Coherence Tomography to measure the blood glucose levels. Current trends and recent results with the device are discussed.

  9. Hybrid CARS for Non-Invasive Blood Glucose Monitoring

    Science.gov (United States)

    Wang, Xi; Pestov, Dmitry; Zhang, Aihua; Murawski, Robert; Sokolov, Alexei; Welch, George; Laane, Jaan; Scully, Marlan

    2007-10-01

    We develop a spectroscopy technique that combines the advantages of both the frequency-resolved coherent anti-Stokes Raman scattering (CARS) and the time-resolved CARS. We use broadband preparation pulses to get an instantaneous coherent excitation of multiplex molecular vibration levels and subsequent optically shaped time-delayed narrowband probing pulse to detect these vibrations. This technique can suppress the nonresonant background and retrieve the molecular fingerprint signal efficiently and rapidly. We employ this technique to glucose detection, the final goal of which is accurate, non-invasive (i.e. painless) and continuous monitoring of blood glucose concentration in the Diabetes diagnosis to replace the current glucose measurement process, which requires painful fingerpricks and therefore cannot be performed more than a few times a day. We have gotten the CARS spectra of glucose aqueous solution down to 2 mM.

  10. Towards a Wearable Non-invasive Blood Glucose Monitoring Device

    International Nuclear Information System (INIS)

    Every day, about 150 Million people worldwide face the problem of diabetic metabolic control. Both the hypo- and hyper- glycaemic conditions of patients have fatal consequences and warrant blood glucose monitoring at regular interval. Existing blood glucose monitors can be widely classified into three classes viz., invasive, minimally invasive, and noninvasive. Invasive monitoring requires small volume of blood and are inappropriate for continuous monitoring of blood glucose. Minimally invasive monitors analyze tissue fluid or extract few micro litre of blood only. Also the skin injury is minimal. On the other hand, noninvasive devices are painless and void of any skin injury. We use an indigenously developed polarization sensitive Optical Coherence Tomography to measure the blood glucose levels. Current trends and recent results with the device are discussed.

  11. Noninvasive blood glucose monitoring by novel optical-fiber probe

    Science.gov (United States)

    Maruo, Katsuhiko; Chin, Jakusei; Tamura, Mamoru

    2002-05-01

    For monitoring the blood glucose level noninvasively from the skin spectra, improvement of signal to noise ratio (S/N) of the glucose signal is critical. This cannot be achieved by the reduction of instrumental noise alone. To reduce the interference from undesired optical signals arising from the stratum corneum and the subcutaneous tissue, we designed a novel optical fiber probe for the skin spectra. The probe consisted of one central optical fiber around which several optical fibers were arranged in circle. The separation of the central optical fiber from each of the surrounding fibers was set at less than 1 mm. This probe was attached to the skin surface vertically when spectral measurements were performed. The measuring light was shone onto the skin surface through the circle fibers and scattered light reaching the central detecting fiber was collected and transmitted to the detection system. The true light path is not defined at present, but light passing through a long path could be neglected with this geometry. When we choose an adequate fiber distance, we can measure the dermis spectra selectively. Glucose intake experiments were performed with volunteers, for whom near-infrared (NIR) spectra were measured at the forearm, from which the blood glucose level was calculated. Partial least square regression (PLSR) analysis was carried out and we found good correlation between the optically estimated values of the glucose level and directly measured values of blood samples. The correlation coefficient characteristic had a positive peak at around 1600 nm, a typical of the glucose spectrum. In conclusion, our system using the novel optical fiber probe detected the changes in the glucose in the human skin tissue quantitatively and noninvasively.

  12. Na+-independent D-glucose transport in rabbit renal basolateral membranes

    International Nuclear Information System (INIS)

    To define the mechanism by which glucose is transported across the basolateral membrane of the renal proximal tubular cell, we measured D-[14C]glucose uptake in basolateral membrane vesicles from rabbit kidney. Na+-dependent D-glucose transport, demonstrable in brush-border vesicles, could not be demonstrated in basolateral membrane vesicles. In the absence of Na+, the uptake of D-[14C]glucose in basolateral vesicles was more rapid than that of L-[3H]glucose over a concentration range of 1-50 mM. Subtraction of the latter from the former uptakes revealed a saturable process with apparent Km of 9.9 mM and Vmax of 0.80 nmol.mg protein-1.s-1. To characterize the transport component of D-glucose uptake in basolateral vesicles, we measured trans stimulation of 2 mM D-[14C]glucose entry in the absence of Na+. Trans stimulation could be effected by preloading basolateral vesicles with D-glucose, 2-deoxy-D-glucose, or 3-O-methyl-D-glucose, but not with L-glucose or alpha-methyl-D-glucoside. Trans-stimulated D-[14C]glucose uptake was inhibited by 0.1 mM phloretin or cytochalasin B but not phlorizin. In contrast, Na+-dependent D-[14C]glucose transport in brush-border vesicles was inhibited by phlorizin but not phloretin or cytochalasin B. Our findings are consistent with the presence of a Na+-independent D-glucose transporter in the proximal tubular basolateral membrane with characteristics similar to those of transporters present in nonepithelial cellsnepithelial cells

  13. Sleep duration and sleep quality are associated differently with alterations of glucose homeostasis

    DEFF Research Database (Denmark)

    Byberg, Stine; Hansen, Anne-Louise Smidt

    2012-01-01

    Abstract Aims? Studies suggest that inadequate sleep duration and poor sleep quality increase the risk of impaired glucose regulation and diabetes. However, associations with specific markers of glucose homeostasis are less well explained. The objective of this study was to explore possible associations of sleep duration and sleep quality with markers of glucose homeostasis and glucose tolerance status in a healthy population-based study sample. Methods? The study comprised 771 participants from the Danish, population-based cross-sectional ‘Health2008’ study. Sleep duration and sleep quality were measured by self-report. Markers of glucose homeostasis were derived from a 3-point oral glucose tolerance test and included fasting plasma glucose, 2-h plasma glucose, HbA1c, two measures of insulin sensitivity (the insulin sensitivity index0,120 and homeostasis model assessment of insulin sensitivity), the homeostasis model assessment of ?-cell function and glucose tolerance status. Associations of sleep duration and sleep quality with markers of glucose homeostasis and tolerance were analysed by multiple linear and logistic regression. Results? A 1-h increment in sleep duration was associated with a 0.3 mmol/mol (0.3%) decrement in HbA1c and a 25% reduction in the risk of having impaired glucose regulation. Further, a 1-point increment in sleep quality was associated with a 2% increase in both the insulin sensitivity index0,120 and homeostasis model assessment of insulin sensitivity, as well as a 1% decrease in homeostasis model assessment of ?-cell function. Conclusions? In the present study, shorter sleep duration was mainly associated with later alterations in glucose homeostasis, whereas poorer sleep quality was mainly associated with earlier alterations in glucose homeostasis. Thus, adopting healthy sleep habits may benefit glucose metabolism in healthy populations.

  14. Analysis: New Point-of-Care Blood Glucose Monitoring System for the Hospital Demonstrates Satisfactory Analytical Accuracy Using Blood from Critically Ill Patients—An Important Step toward Improved Blood Glucose Control in the Hospital

    OpenAIRE

    Joseph, Jefrey I

    2013-01-01

    Patients managed in the intensive care units (ICUs) and general wards of the hospital experience a high incidence of hyperglycemia, hypoglycemia, and glycemic variability, despite significant hospital resources devoted to glucose control. Optimized glucose meters and monitoring systems are required to improve the safety and efficacy of insulin delivery and glucose control in the hospital. Safe insulin dosing requires timely and accurate glucose measurements, especially during dynamic changes ...

  15. Analog-to-digital conversion

    CERN Document Server

    Pelgrom, Marcel J M

    2010-01-01

    The design of an analog-to-digital converter or digital-to-analog converter is one of the most fascinating tasks in micro-electronics. In a converter the analog world with all its intricacies meets the realm of the formal digital abstraction. Both disciplines must be understood for an optimum conversion solution. In a converter also system challenges meet technology opportunities. Modern systems rely on analog-to-digital converters as an essential part of the complex chain to access the physical world. And processors need the ultimate performance of digital-to-analog converters to present the results of their complex algorithms. The same progress in CMOS technology that enables these VLSI digital systems creates new challenges for analog-to-digital converters: lower signal swings, less power and variability issues. Last but not least, the analog-to-digital converter must follow the cost reduction trend. These changing boundary conditions require micro-electronics engineers to consider their design choices for...

  16. Acetaminophen Glucuronide and Plasma Glucose Report Identical Estimates of Gluconeogenesis and Glycogenolysis for Healthy and Pre-diabetic Subjects Using the Deuterated Water Method

    OpenAIRE

    Barosa, Cristina; Jones, John G.; Rizza, Robert; Basu, Ananda; Basu, Rita

    2012-01-01

    Plasma glucose 2H-enrichment in positions 5 (2H5) and 2 (2H2) from deuterated water (2H2O) provides a measure of the gluconeogenic contribution to endogenous glucose production (EGP). Urinary glucuronide analysis can circumvent blood sampling but it is not known if glucuronide and glucose enrichments are equal. 15 subjects with impaired fasting glucose/impaired glucose tolerance (IFG/IGT) and 11 subjects with normal fasting glucose and normal glucose tolerance (NFG/NGT) ingested 2H2O to ~0.5%...

  17. Glucose Signaling in Saccharomyces cerevisiae

    OpenAIRE

    Santangelo, George M.

    2006-01-01

    Eukaryotic cells possess an exquisitely interwoven and fine-tuned series of signal transduction mechanisms with which to sense and respond to the ubiquitous fermentable carbon source glucose. The budding yeast Saccharomyces cerevisiae has proven to be a fertile model system with which to identify glucose signaling factors, determine the relevant functional and physical interrelationships, and characterize the corresponding metabolic, transcriptomic, and proteomic readouts. The early events in...

  18. Analog filters in nanometer CMOS

    CERN Document Server

    Uhrmann, Heimo; Zimmermann, Horst

    2013-01-01

    Starting from the basics of analog filters and the poor transistor characteristics in nanometer CMOS 10 high-performance analog filters developed by the authors in 120 nm and 65 nm CMOS are described extensively. Among them are gm-C filters, current-mode filters, and active filters for system-on-chip realization for Bluetooth, WCDMA, UWB, DVB-H, and LTE applications. For the active filters several operational amplifier designs are described. The book, furthermore, contains a review of the newest state of research on low-voltage low-power analog filters. To cover the topic of the book comprehen

  19. Analog Systems for Gravity Duals

    CERN Document Server

    Hossenfelder, S

    2014-01-01

    We show that analog gravity systems exist for charged, planar black holes in asymptotic Anti-de Sitter space. These black holes have been employed to describe, via the gauge-gravity duality, strongly coupled condensed matter systems on the boundary of AdS-space. The analog gravity system is a different condensed matter system that, in a suitable limit, describes the same bulk physics as the theory on the AdS boundary. This combination of the gauge-gravity duality and analog gravity therefore suggests a duality between different condensed matter systems.

  20. Analog Systems for Gravity Duals

    OpenAIRE

    Hossenfelder, S.

    2014-01-01

    We show that analog gravity systems exist for charged, planar black holes in asymptotic Anti-de Sitter space. These black holes have been employed to describe, via the gauge-gravity duality, strongly coupled condensed matter systems on the boundary of AdS-space. The analog gravity system is a different condensed matter system that, in a suitable limit, describes the same bulk physics as the theory on the AdS boundary. This combination of the gauge-gravity duality and analog ...

  1. Real-Time Continuous Glucose Monitoring Shows High Accuracy within 6 Hours after Sensor Calibration: A Prospective Study

    OpenAIRE

    Yue, Xiao-Yan; Zheng, Yi; Cai, Ye-Hua; Yin, Ning-Ning; Zhou, Jian-Xin

    2013-01-01

    Accurate and timely glucose monitoring is essential in intensive care units. Real-time continuous glucose monitoring system (CGMS) has been advocated for many years to improve glycemic management in critically ill patients. In order to determine the effect of calibration time on the accuracy of CGMS, real-time subcutaneous CGMS was used in 18 critically ill patients. CGMS sensor was calibrated with blood glucose measurements by blood gas/glucose analyzer every 12 hours. Venous blood was sampl...

  2. Construction of a Glucose Biosensor by Immobilizing Glucose Oxidase within a Poly(o-phenylenediamine Covered Screen-printed Electrode

    Directory of Open Access Journals (Sweden)

    Miao Yuqing

    2006-01-01

    Full Text Available The glucose biosensors were prepared by the electropolymerization of the non-conductive polymer, Poly(o-phenylenediamine, onto a planar screen-printed electrode. A fabrication procedure was performed to decrease the waste of expensive enzyme. The amperometric glucose response was measured by the potensiostating of the prepared glucose biosensors at a potential of 0.3 V with ferrocene as mediator. Results show that the obtained biosensors have a linear range up to 25 mM glucose, fast response time (100s and high sensitivities (16.6 nA/mM. Also, the effects of applied potential and sweeping number of Cyclic voltammograms for electropolymerization were systematically investigated and optimal values were recorded.

  3. Cyclic Correlation of Diffuse Reflected Signal with Glucose Concentration and scatterer size

    CERN Document Server

    Solanki, Jitendra; Andrews, Joseph Thomas; Thareja, Kamal Kishore; 10.4236/jmp.2012.31009

    2012-01-01

    The utility of optical coherence tomography signal intensity for measurement of glucose concentration has been analysed in tissue phantom and blood samples from human subjects. The diffusion equation based calculations as well as in-vivo OCT signal measurements confirms the cyclic correlation of signal intensity with glucose concentration and scatterer size.

  4. Thermal Conductivity Measurements on Icy Satellite Analogs

    Science.gov (United States)

    Javeed, Aurya; Barmatz, Martin; Zhong, Fang; Choukroun, Mathieu

    2012-01-01

    With regard to planetary science, NASA aspires to: "Advance scientific knowledge of the origin and history of the solar system, the potential for life elsewhere, and the hazards and resources present as humans explore space". In pursuit of such an end, the Galileo and Cassini missions garnered spectral data of icy satellite surfaces implicative of the satellites' structure and material composition. The potential for geophysical modeling afforded by this information, coupled with the plausibility of life on icy satellites, has pushed Jupiter's Europa along with Saturn's Enceladus and Titan toward the fore of NASA's planetary focus. Understanding the evolution of, and the present processes at work on, the aforementioned satellites falls squarely in-line with NASA's cited goal.

  5. Synthesis of high specific activity [1-3H]-D-glucose

    International Nuclear Information System (INIS)

    Specifically labeled [1-3H]-D-glucose has been used for metabolic and mechanistic studies in erythrocytes. In vitro metabolism of the a and b anomers of the tritiated glucose was readily traced by 3H NMR spectroscopy. Initial studies used labeled glucose obtained by catalytic exchange labeling (at 4.5-9 Ci/mmole, or 15-30% tritiated at the C-1 position), and this necessitated sample glucose concentrations of 2-4 times physiological. The availability of glucose at maximum specific activity (28.7 Ci/mmole, 100% at the C-1 position) would allow the authors to observe metabolic behavior using 1 mM levels of glucose. Accordingly, they have devised a new route for the synthesis of C-1 tritiated glucose, involving the synthesis of 4,6-O-benzylidene-D-gluconolactone followed by reduction with supertritide. Preliminary work with commercial superdeuteride is complete, and chromatographic and NMR analyses are promising. The analogous tritium reactions are currently underway, and experimental results are presented for all stages of investigation. This strategy should be generally applicable to the labeling of many reducing sugars, with the substrates 2-deoxyglucose and maltotriose being of particular interest to their research

  6. HAPS, a Handy Analog Programming System

    DEFF Research Database (Denmark)

    HØjberg, Kristian SØe

    1975-01-01

    HAPS (Hybrid Analog Programming System) is an analog compiler that can be run on a minicomputer in an interactive mode. Essentially HAPS is written in FORTRAN. The equations to be programmed for an ana log computer are read in by using a FORTRAN-like notation. The input must contain maximum and minimum values for the variables. The output file includes potentiometer coefficients and static-test 'measuring values.' The file format is fitted to an automatic potentiometer-setting and static-test program. Patch instructions are printed by HAPS. The article describes the principles of HAPS and emphasizes the limitations HAPS puts on equation structure, types of computing circuit, scaling, and static testing.

  7. Dielectric Analog Space-Times

    OpenAIRE

    Thompson, Robert T.; Frauendiener, Jörg

    2010-01-01

    We generalize the notion of a dielectric analog Schwarzschild black hole model to analog models of arbitrary space-times; in particular, the approach is not restricted to static space-times. This is done by establishing a correspondence between electrodynamics on a curved, vacuum manifold, with electrodynamics in a general linear dielectric residing in Minkowski space-time. The mapping is not unique, allowing for some freedom in the specification of equivalent materials, whi...

  8. Review of Glucose Oxidases and Glucose Dehydrogenases: A Bird's Eye View of Glucose Sensing Enzymes

    OpenAIRE

    Ferri, Stefano; Kojima, Katsuhiro; Sode, Koji

    2011-01-01

    The evolution from first-generation through third-generation glucose sensors has witnessed the appearance of a number of very diverse oxidoreductases, which vary tremendously in terms of origin, structure, substrate specificity, cofactor used as primary electron acceptor, and acceptable final electron acceptor. This article summarizes our present knowledge of redox enzymes currently utilized in commercially available glucose monitoring systems to promote a fuller appreciation of enzymatic pro...

  9. A mathematical model of brain glucose homeostasis

    OpenAIRE

    Kimura Hidenori; Gaohua Lu

    2009-01-01

    Abstract Background The physiological fact that a stable level of brain glucose is more important than that of blood glucose suggests that the ultimate goal of the glucose-insulin-glucagon (GIG) regulatory system may be homeostasis of glucose concentration in the brain rather than in the circulation. Methods In order to demonstrate the relationship between brain glucose homeostasis and blood hyperglycemia in diabetes, a brain-oriented mathematical model was developed by considering the brain ...

  10. Regulation of glycolytic rate in Streptococcus sanguis grown under glucose-limited and glucose-excess conditions in a chemostat.

    OpenAIRE

    Iwami, Y; Yamada, T.

    1985-01-01

    The biochemical mechanisms of the acidogenic potential of Streptococcus sanguis ATCC 10556 grown in glucose-excess and glucose-limited continuous culture were studied. The rate of acid production during the glucose metabolism by the cells grown under glucose limitation (glucose-limited cells) was 2.1 to 2.6 times that by the cells grown in an excess of glucose (glucose-excess cells). When the glucose-limited cells were metabolizing glucose, intracellular concentrations of glucose 6-phosphate,...

  11. Glucose effectiveness in nondiabetic relatives : dysglycemia and ?-cell function at 10 years

    DEFF Research Database (Denmark)

    Egede, M B; Henriksen, J-E

    2014-01-01

    AIMS: Reduced glucose effectiveness is a predictor of future glucose tolerance in individuals with a family history of type 2 diabetes. We examined retrospectively at 10 years in normoglycemic relatives of diabetic subjects (RELs) the pathophysiological role of glucose effectiveness in the development of isolated impaired fasting glucose, glucose intolerance, and acute insulin release. METHODS: At 0 years, 19 RELs and 18 matched control subjects had glucose effectiveness (GE), insulin sensitivity, acute insulin release (AIR)IVGTT, and disposition index measured during an iv glucose tolerance test (IVGTT), using the minimal model analysis. At 0 and 10 years, oral glucose tolerance (OGTT) and AIROGTT were determined. RESULTS: At 0 years, fasting glucose (FG) and GE were raised in RELs, but insulin sensitivity and AIROGTT were reduced (P ? .05) compared with controls. At 10 years, RELs developed raised fasting and 2-hour OGTT glucose. FG10y correlated significantly with FG0y and body mass index0y and negatively with ?GE and 2-hour OGTT glucose10y with FG0y and negatively with AIRIVGTT0y and AIROGTT0y. Log AIROGTT10y correlated with ?GE, log AIRIVGTT0y and log AIROGTT0y. Multiple regression analyses demonstrated the following: REL FG10y was predicted by combined FG0y, ?GE and body mass index0y (radj(2) = 56%; P ? .001) and 2-hour OGTT glucose10y weakly related by FG0y,and ?GE (r(adj)(2) = 25%; P = .06). Log AIROGTT10y was predicted by AIRIVGTT0y and ?GE (r(adj)(2) = 46%; P ? .004). CONCLUSION: In normoglycemic RELs, a relative reduction of glucose effectiveness is an important contributor over 10 years to the development of isolated impaired fasting glucose and reduced acute insulin secretion.

  12. An ozone budget for the UK: using measurements from the national ozone monitoring network; measured and modelled meteorological data, and a 'big-leaf' resistance analogy model of dry deposition

    International Nuclear Information System (INIS)

    A method of calculating a mass budget for O3 in the UK boundary layer is presented which shows that the spatial scale of the UK is small relative to the footprint of the atmosphere influenced by UK emissions. - Data from the UK national air-quality monitoring network are used to calculate an annual mass budget for ozone (O3) production and loss in the UK boundary layer during 1996. Monthly losses by dry deposition are quantified from 1 kmx1 km scale maps of O3 concentration and O3 deposition velocities based on a 'big-leaf' resistance analogy. The quantity of O3 deposition varies from ?50 Gg-O3 month-1 in the winter to over 200 Gg-O3 month-1 in the summer when vegetation is actively absorbing O3. The net O3 production or loss in the UK boundary layer is found by selecting days when the UK is receiving 'clean' Atlantic air from the SW to NW. In these conditions, the difference in O3 concentration observed at Mace Head and a rural site on the east coast of the UK indicates the net O3 production or loss within the UK boundary layer. A simple box model is then used to convert the concentration difference into a mass. The final budget shows that for most of the year the UK is a net sink for O3 (-25 to -800 Gg-O3 month-1) with production only exceeding losses in the photochemically active summer monin the photochemically active summer months (+45 Gg-O3 month-1)

  13. Fluorinated glucose analog, 2-fluoro-2-deoxy-D-glucose (F-18): nontoxic tracer for rapid tumor detection

    International Nuclear Information System (INIS)

    Rapid uptake of F-18 FDG was observed in a variety of transplanted and spontaneous tumors in animals. The tumor uptake reached a peak by 30 min and remained relatively constant up to 60 min, with a very slow wash-out of F-18 activity from the tumor thereafter. Tumor-to-normal tissue and tumor-to-blood ratios ranged from 2.10 to 9.15 and 2.61 to 17.82, respectively, depending on the type of tumor. A scintiscan of a seminoma in a dog showed very high uptake in the viable part and lack of uptake in the necrotic mass. Toxicological studies in mice using 1000 times human tracer dose (HTD) per week for 3 weeks and in dogs using 50 times HTD per week for 3 weeks did not show any evidence of acute or chronic toxicity

  14. Performance report for Stanford/SLAC Microstore Analog Memory Unit

    International Nuclear Information System (INIS)

    Tests of a newly developed Analog Memory Unit (AMU) are described. The device contains 256 analog storage cells consisting of pass transistors, a storage capacitor and a differential read out buffer. By addressing the storage cells sequentially, the shape of the signal present at the input can be recorded in time. Fast response and good amplitude resolution were the design goals for the development. Measurements on individual devices will be presented and the status of hybridized subsystems containing eight AMUs discussed

  15. The boundary-scan handbook analog and digital

    CERN Document Server

    Parker, Kenneth P

    2007-01-01

    List of Figures. List of Tables. List of Design-for-Test Rules. Preface to the First Edition. Preface to the Second Edition. Acknowledgement. 1. Boundary-Scan Basics and Vocabulary. 2. Boundary-Scan Description Language (BSDL). 3. Boundary-Scan Testing. 4. Advanced Boundary-Scan Topics. 5. Design for Boundary-Scan Test. 6. Analog Measurement Basics. 7. IEEE 1149.4 Analog Boundary-Scan. Appendix A: BSDL Syntax Specifications. References. Index.

  16. LC/MS quantitative study of glucose by iodine attachment

    International Nuclear Information System (INIS)

    We explored the potential of iodine attachment to improve the sensitivity of glucose measurement by LC/MS. After sample preparation, glucose was separated by normal phase chromatography, followed by anionization by I--attachment prior to MS by post-column addition of a methanolic solution of iodoform. Iodine is capable of forming an anionic adduct with neutral monosaccharides in negative ion mode electrospray mass spectrometry. Quasi-molecular ions [M + I]- of glucose, and [6,6-2H2]glucose (abbreviated d2-glucose) internal standard were quantitated in selected ion monitoring (SIM) mode. Iodine attachment LC/MS analysis provided high sensitivity, superior to GC/MS. It greatly simplified sample preparation and increased throughput. The advantages of iodine attachment can be realized even on old mass spectrometers. A LOD of 50 pg glucose on column was achieved. Due to iodine's predisposition to sublimate, the iodoform concentration must be minimized, which adds complexity to method development. To optimize reagent concentration we developed an efficient and flexible gradient-based delivery platform. Strategy for method development with iodoform is given

  17. Cerebral glucose metabolism in Parkinson's disease with and without dementia.

    Science.gov (United States)

    Peppard, R F; Martin, W R; Carr, G D; Grochowski, E; Schulzer, M; Guttman, M; McGeer, P L; Phillips, A G; Tsui, J K; Calne, D B

    1992-12-01

    Although cognitive impairment is commonly associated with Parkinson's disease, the relative importance of cortical and subcortical pathologic changes to the development of dementia is controversial. Characteristic abnormalities in cortical glucose metabolism have been reported previously in Alzheimer's disease, a disease in which cortical changes predominate. We measured cerebral glucose metabolism with positron emission tomography in 20 control subjects and in 14 patients with PD with mental status ranging from normal to severely demented to determine whether changes in cortical glucose metabolism occur in early PD and whether the degree and pattern of metabolic change relate to the severity of dementia. The patients were divided into demented and nondemented groups according to the results of neuropsychological assessment. Age-adjusted covariance analyses were performed, since the age distribution varied between groups. The nondemented patients with PD showed widespread cortical glucose hypometabolism without any selective temporoparietal defects. The pattern of glucose hypometabolism seen in the demented patients with PD resembled that described in patients with Alzheimer's disease; ie, there was a global decrease in glucose metabolism, with more severe abnormalities observed in the temporoparietal regions. PMID:1449406

  18. Self glucose monitoring and physical exercise in diabetes.

    Science.gov (United States)

    Pugliese, G; Zanuso, S; Alessi, E; Simonelli, P; Fallucca, S; Fallucca, F; Balducci, S

    2009-09-01

    Cardiorespiratory fitness, which is determined mainly by the level of physical activity, is inversely related to mortality in the general population as well as in subjects with diabetes, the incidence of which is also increased by low exercise capacity. Exercise is capable of promoting glucose utilization in normal subjects as well as in insulin-deficient or insulin-resistant diabetic individuals. In diabetic subjects treated with insulin or insulin secretagogues, exercise may also result in complications, with too much insulin causing hypoglycaemia and not enough insulin leading to hyperglycaemia and possibly ketoacidosis; both complications may also occur several hours after exercise. Therefore, self-monitoring of blood glucose before, during (for exercise duration of more than 1 h) and after physical exercise is highly recommended, and also carbohydrate supplementation may be required. In the Italian Diabetes Exercise Study (IDES), measurement of blood glucose and systolic and diastolic blood pressure levels before and after supervised sessions of combined (aerobic + resistance) exercise in type 2 diabetic subjects with the metabolic syndrome showed significant reductions of these parameters, though no major hypoglycaemic or hypotensive episode was detected. The extent of reduction of blood glucose was related to baseline values but not to energy expenditure and was higher in subjects treated with insulin than in those on diet or oral hypoglycaemic agents (OHA). Thus, supervised exercise training associated with blood glucose monitoring is an effective and safe intervention to decrease blood glucose levels in type 2 diabetic subjects. PMID:19662620

  19. Fasting Glucose, Diagnosis of Type 2 Diabetes, and Depression: The Vietnam Experience Study

    OpenAIRE

    Gale, Catharine R.; Kivimaki, Mika; Lawlor, Debbie A.; Carroll, Douglas; Phillips, Anna C.; Batty, G. David

    2010-01-01

    Background: Recent findings suggest that both low and very high fasting blood glucose concentrations may be linked with depression, though whether type 2 diabetes is associated with depression may depend on awareness of the diagnosis. We explored the association between fasting glucose and type 2 diabetes (undiagnosed and diagnosed) and depression in middle-aged men. Methods: Participants were 4293 US veterans who underwent an examination during which fasting blood glucose was measured, ...

  20. The synthesis of phosphoribosylpyrophosphate from glucose decreases during amino acid starvation of human lymphoblasts

    International Nuclear Information System (INIS)

    Rib-5-P and PP-Rib-P may be produced from glucose via the oxidative and nonoxidative pentose phosphate pathway. The autthors attempt to know which of these two pathways provides most of the PP-Rib-P needed for nuceotide synthesis and try to determine the regulation of Rib-5-P synthesis from glucose. The effect of amino acid starvation on the oxidative pentose phosphate pathway was examined by measuring 14CO2 production from (1-14C) glucose

  1. Retinal vessel diameters and risk of impaired fasting glucose or diabetes: the Rotterdam study

    OpenAIRE

    Ikram, M. K.; Roos, A. M.; Rietveld, I.; Witteman, J. C. M.; Breteler, M. M. B.; Duijn, C. M.; Jong, P. T. V. M.; Janssen, J. A. M. J. L.; Hofman, A.

    2006-01-01

    The association between a smaller retinal arteriolar-to-venular ratio (AVR) and incident diabetes may be due to arteriolar narrowing, venular dilatation, or both. We investigated associations between baseline vessel diameters and incident impaired fasting glucose or diabetes in a population-based cohort (aged > or =55 years). Baseline retinal vessel diameters (1990-1993) were measured on digitized images of 2,309 subjects with a normal glucose tolerance test (postload glucose or =7.0 mmol/l ...

  2. A Feedforward—Feedback Glucose Control Strategy for Type 1 Diabetes Mellitus

    OpenAIRE

    Marchetti, Gianni; Barolo, Massimiliano; Jovanovic?, Lois; Zisser, Howard; Seborg, Dale E.

    2008-01-01

    As the “artificial pancreas” becomes closer to reality, automated insulin delivery based on real-time glucose measurements becomes feasible for people with diabetes. This paper is concerned with the development of novel feedforward-feedback control strategies for real-time glucose control and type 1 diabetes. Improved post-meal responses can be achieved by a pre-prandial snack or bolus, or by reducing the glucose setpoint prior to the meal. Several feedforward-feedback control strategies ...

  3. Impact of Epidemic Rates of Diabetes on the Chinese Blood Glucose Testing Market

    OpenAIRE

    Hu, Jamie; Zhang, Xian-en

    2011-01-01

    China has become the country with the largest diabetes mellitus population in the world since the 1990s. About 100 million diabetes cases have been diagnosed since 2008. Handheld blood glucose meters and test strips are urgently needed for daily patient measurement. The glucose monitor with a screen-printed carbon-based glucose electrode has been in commercial production since 1994. Since then, approximately 20 companies have been involved in manufacturing and marketing meters and test strips...

  4. Novel chemico-mechanical approach towards long-term implantable glucose sensing

    OpenAIRE

    Boss, Christophe; Meurville, Eric; Sallese, Jean-Michel; Ryser, Peter

    2009-01-01

    The proof of concept of a continuously sensing affinity device based on the glucose-dependent viscosity of a sensitive solution containing dextran and Concanavalin A has been successfully demonstrated. The biosensor incorporates a piezoelectric diaphragm and a flow-resisting microchannel for viscosity detection, and a free-standing Anodic Alumina Oxide (AAO) porous nano-membrane as glucose selective interface. Extensive in vitro glucose measurements between two physiologically relevant glucos...

  5. New light upon non-invasive blood glucose monitoring

    Science.gov (United States)

    Davies-Shaw, D.; Davies, N.

    2006-02-01

    We at Fibersense and Signals are pleased to report the research and development of novel multiple-wavelength and multi-spectral techniques and devices to distinguish glucose from a comprehensive panel of other spectrally evident and interactive blood components such as: albumin, salts, urea and amino acids. A highly selective, glucose-specific bio-spectroscopic technique has been developed to provide clinically-relevant information regarding glucose concentrations. Furthermore, this work has resulted in novel multi-wavelength technology and techniques for the non-invasive detection and continuous non-invasive monitoring of blood glucose levels. As a developer of fiber optic, photonic and laser-related products as well as optical test and measurement instrumentation, Fibersense has used an essentially problem-solving approach to address practical issues that have long hindered progress in non-invasive glucose detection and monitoring, and has overcome the limitations of previous techniques. We have fabricated and optimized optical sources for this application, specifically with respect to useful wavelength ranges, transmittance rates, reflectance, absorption and scattering/dispersion. We have also characterized a multi-wavelength combination and procedure to address and screen out the spectral overlapping of glucose and common blood compounds within physiological criteria. Furthermore, attention has been paid to the viable optical launching of effective wavelengths and the ultra-sensitive optical pick up and detection within very tight wavelength margins to generate useful blood glucose information. The culmination of these techniques has been the design and fabrication of miniaturized, non-invasive multi-channel glucose sensors with dynamic self-calibration features for use in in vitro and experimental in vivo applications.

  6. The effect of metformin on glucose homeostasis during moderate exercise

    DEFF Research Database (Denmark)

    Hansen, Merethe; PalsØe, Marie K

    2015-01-01

    OBJECTIVE: We investigated the role of metformin on glucose kinetics during moderate exercise. RESEARCH DESIGN AND METHODS: Before, during, and after a 45-min bout of exercise at 60% VO2max, glucose kinetics were determined by isotope tracer technique in patients with type 2 diabetes mellitus with metformin treatment (DM2+Met) or without metformin treatment (DM2) and in healthy control subjects (CON) matched for BMI and age. Glucoregulatory hormones and metabolites were measured throughout the study. RESULTS: Plasma glucose concentration was unchanged during exercise in CON but decreased in DM2. No significant change was found in DM2+Met. Hormones and metabolites showed no differences among the groups except for elevated exercise-induced concentrations of lactate in DM2 (area under the curve [AUC] 31 ± 1% vs. CON) and glucagon in DM2 (AUC 5 ± 1% vs. DM2+Met). Free fatty acid levels were lower in DM2+Met than in DM2 (AUC -14 ± 1%). Absolute values of the baseline glucose rate of appearance (Ra) were elevatedin DM2 and DM2+Met, but the increase in glucose Ra relative to baseline was blunted in DM2 (19 ± 1%) and DM2+Met (18 ± 4%) compared with CON (46 ± 4%). Glucose rate of disappearance relative to baseline increased more in CON (31 ± 3%) than in DM2 (6 ± 1%) and DM2+Met (21 ± 2%), showing a small increase caused by metformin. Glucose metabolic clearance rate relative to baseline was similar during exercise in DM2 (33 ± 1%) and CON (35 ± 3%) but was improved in DM2+Met (37 ± 3%) compared with DM2. CONCLUSIONS: Metformin has a positive effect on glucose homeostasis during exercise.

  7. The glucose sensor: the missing link in diabetes therapy.

    Science.gov (United States)

    Pfeiffer, E F

    1990-01-01

    This review considers the present state of the implantable glucose sensor from the point of view of technical models available today. Chemical analysis behind the practical experiences under both in vitro and in vivo conditions are described (Abel, Fischer, Brunstein and Ertle 1988; Brückel, Kerner, Zier, Steinbach and Pfeiffer 1988a; Brückel, Kerner, Zier, Steinbach and Pfeiffer 1988b; Steinbach, Kerner, Zier, Dolderer and Pfeiffer 1987). Amperometric enzymatic glucose sensors are used by the majority of laboratories, providing satisfactory results of glucose determinan in solution and in the laboratory. Up to 4 days of reliable values were recorded by measuring glucose in vivo, in practical terms, in the subcutaneous tissue in animals. However, also in this first period of foreign-body reactions, enough encapsulation obviously occurs to neutralize the majority of the sensors implanted. In first experiments in humans, the results are even worse. Generally, decreasing activity was observed in less than 24 h. Therefore, continuous blood glucose monitoring by portable glucose sensors used the same principle in a flow-through chamber; the sensor of our own make was employed in a number of clinical conditions. When one of the available insulin pumps effecting continuous subcutaneous insulin infusions was connected, the algorithms worked out for the big AEP under bedside conditions were also of use in a slightly modified fashion for the subcutaneous insulin application. Renouncing the computer-mediated automated regulation of the insulin delivery is possible when the patient is constantly reading his blood glucose values and operates the insulin infusion pulses in association with meals. Continuous glucose monitoring by portable instruments is the only and irreplaceable prerequisite for unprejudiced evaluation of the various strategies for substitution of the insulin deficiency in any form of diabetes. PMID:2272621

  8. Glucose and insulin variations in patients during the time course of a FDG-PET study and implications for the 'glucose-corrected' SUV

    International Nuclear Information System (INIS)

    Introduction: 2-Deoxy-2[18F]fluoro-D-glucose (FDG) positron emission tomography (PET) has an established role in the evaluation of cancer. Generally, tumor uptake and response to treatment are evaluated using the standardized uptake value (SUV). Some authors have proposed correcting SUV for glucose levels. Insulin is also thought to influence tumor uptake by changing uptake in other tissues. However, little attention has been paid to understanding the variability of glucose or insulin during a single PET study. Method: We studied the biological and instrumental variability of glucose and insulin measurements in 71 nondiabetic patients undergoing FDG-PET studies. Multiple glucose measurements were obtained in all 71 subjects, and in 69 of these 71 subjects, multiple serum insulin measurements were made. We determined the coefficient of observed variation (CVow) and the coefficient of variation attributable to biological variability (CVbv) for both glucose and insulin. Results: The mean glucose concentration was 78.9±13.5 mg/dl. The mean insulin value was 6.49±5.92 ?U/ml. The weighted mean CVow and CVbv was 5.0% and 3.6%, respectively, for glucose and 14.2% and 8.3%, respectively, for insulin. Conclusions: Variations in the range of 3.6% are observed in glucose measurements during the time course of an FDG scan even after accounting for analytical error; larger variations of 8.3% are observed in insulin levels. T 8.3% are observed in insulin levels. Therefore, corrections of SUV for blood glucose, especially if obtained from single measurements, can introduce additional errors of at least this much

  9. Monitoring nutrition and glucose in acute brain injury.

    Science.gov (United States)

    Badjatia, Neeraj; Vespa, Paul

    2014-12-01

    The metabolic response to injury is well described; however, very little is understood about optimal markers to measure this response. This summary will address the current evidence about monitoring nutritional status including blood glucose after acute brain injury (ABI). An electronic literature search was conducted for English language articles describing the testing, utility, and optimal methods to measure nutritional status and blood glucose levels in the neurocritical care population. A total of 45 articles were included in this review. Providing adequate and timely nutritional support can help improve outcome after ABI. However, the optimal content and total nutrition requirements remain unclear. In addition, how best to monitor the nutritional status in ABI is still being elucidated, and at present, there is no validated optimal method to monitor the global response to nutritional support on a day-to-day basis in ABI patients. Nitrogen balance may be monitored to assess the adequacy of caloric intake as it relates to protein energy metabolism, but indirect calorimetry, anthropometric measurement, or serum biomarker requires further validation. The adverse effects of hyperglycemia in ABI are well described, and data indicate that blood glucose should be carefully controlled in critically ill patients. However, the optimal frequency or duration for blood glucose monitoring after ABI remains poorly defined. There are significant knowledge gaps about monitoring nutritional status and response to nutritional interventions in ABI; these need to be addressed and hence few recommendations can be made. The optimal frequency and duration of blood glucose monitoring need further study. PMID:25208674

  10. Why Have So Many Intravascular Glucose Monitoring Devices Failed?

    Science.gov (United States)

    Smith, John L; Rice, Mark J

    2015-07-01

    Secondary to the inherent limitations of both point-of-care and central laboratory glucose technologies, continuous glucose measurement has recently enjoyed a high level of investment. Because of the perceived advantages by some of measuring in the intravascular space compared to the subcutaneous tissue, a number of technologies have been developed. In this review, we evaluate nine systems that have shown promise, although only one of these has been cleared for sale in the United States. The detection methodology, regulatory status, technical issues, and company circumstance surrounding each technology are examined. PMID:26129733

  11. Low glucose relates to greater aggression in married couples

    OpenAIRE

    Bushman, Brad J.; DeWall, C. Nathan; Pond, Richard S.; Hanus, Michael D.

    2014-01-01

    People are often the most aggressive against the people to whom they are closest—intimate partners. Intimate partner violence might be partly a result of poor self-control. Self-control of aggressive impulses requires energy, and much of this energy is provided by glucose derived from the food we eat. We measured glucose levels in 107 married couples over 21 days. To measure aggressive impulses, participants stuck 0–51 pins into a voodoo doll that represented their spouse each night, dependin...

  12. Rapid enhancement of brush border glucose uptake after exposure of rat jejunal mucosa to glucose.

    OpenAIRE

    Sharp, P.A.; Debnam, E S; Srai, S. K.

    1996-01-01

    BACKGROUND: Increased jejunal glucose transport after ingestion of carbohydrate rich diets may reflect higher concentrations of lumenal glucose. Normal processing of carbohydrate causes wide fluctuations in glucose concentration in the jejunal lumen and this raises the question of whether the high lumenal concentrations seen at peak digestion affect glucose uptake. AIMS: To study the effects of 30 minute exposure of rat jejunal mucosa to glucose on sodium-glucose transporter (SGLT1) mediated ...

  13. Theory of analogous force on number sets

    International Nuclear Information System (INIS)

    A general statistical thermodynamic theory that considers given sequences of x-integers to play the role of particles of known type in an isolated elastic system is proposed. By also considering some explicit discrete probability distributions px for natural numbers, we claim that they lead to a better understanding of probabilistic laws associated with number theory. Sequences of numbers are treated as the size measure of finite sets. By considering px to describe complex phenomena, the theory leads to derive a distinct analogous force fx on number sets proportional to (?px/?x)T at an analogous system temperature T. In particular, this yields to an understanding of the uneven distribution of integers of random sets in terms of analogous scale invariance and a screened inverse square force acting on the significant digits. The theory also allows to establish recursion relations to predict sequences of Fibonacci numbers and to give an answer to the interesting theoretical question of the appearance of the Benford's law in Fibonacci numbers. A possible relevance to prime numbers is also analyzed. (author)

  14. Biological evaluation of two anomeric glucose analogues iodinated in position 6

    Energy Technology Data Exchange (ETDEWEB)

    Koumanov, Francoise; Henry, Christelle; Ghezzi, Catherine; Mathieu, Jean-Paul; Morin, Christophe; Vidal, Michel; Leiris, Joeel de; Comet, Michel; Fagret, Daniel

    1997-08-01

    Two anomeric analogues of glucose labelled with 123 iodine in position 6, proposed as tracers of glucose transport in vivo, have been synthesized: {alpha}- and {beta}-methyl-6-deoxy-6-iodo-D-glucopyranoside ({alpha}MDIG and {beta}MDIG). The aim of this study was to determine whether these molecules interact with the glucose transporter and whether they could be used as tracers of glucose transport in vivo. The biodistribution of {alpha}MDIG and {beta}MDIG was studied in the mouse in vivo. To determine if these two anomers enter the cell via the glucose transporter, their uptake was measured in isolated perfused rat hearts, in human erythrocytes in suspension, and in cardiomyocytes of neonatal rat in culture. Both {alpha}MDIG and {beta}MDIG had similar repartitions in the mouse: myocardial uptake averaged 7% of the injected dose/g of organ at 2 min postinjection and {alpha}MDIG competed with D-glucose to enter the cells. Insulin produced a 123% increase of its uptake in isolated perfused rat hearts and a 100% increase in cardiomyocytes of neonatal rat in culture. {alpha}MDIG uptake was lowered in the presence of glucose transport inhibitors in each experimental model. An interaction between {beta}MDIG and glucose transporters was observed only in human erythrocytes in suspension. Only {alpha}MDIG interacts with the glucose transporter, and thus could be used to estimate glucose transport in vivo.

  15. Glucose transport by radiation-induced insulinoma and clonal pancreatic beta-cells

    International Nuclear Information System (INIS)

    Sugar uptake was measured in dispersed cells prepared from radiation-induced insulinomas transplantable in NEDH rats and in three clonal beta-cell lines maintained in continuous culture (RIN m5F, RIN 1046, HIT). Uptake of D-glucose and 3-O-methyl-D-glucose by insulinoma cells was rapid so that the intracellular concentration of D-hexoses approximated the concentration in the incubation medium by 15-30 s. L-Glucose was taken up only slowly. 3-O-methyl-D-glucose uptake by RIN m5F, RIN 1046, and HIT cells was slow; with 1 mM 3-O-methylglucose in the medium, equilibrium was attained at 20 min, but with 10 mM 3-O-methylglucose, equilibrium was not attained even at 20 min. In HIT cells incubated with D-glucose for 30 min, the intracellular concentration of glucose was less than the medium glucose concentration, indicating glucose transport is a nonequilibrium reaction in this cell line. These data indicate that radiation-induced insulinoma cells retain the capacity of normal beta-cells to transport sugar at high rates. RIN m5F, RIN 1046, and HIT cells transport sugar slowly, however, and thus differ from normal beta-cells. In RIN m5F, RIN 1046, and HIT cells, unlike in normal beta-cells, glucose transport may be the site regulating glucose metabolism

  16. A ``plasmonic cuvette'': dye chemistry coupled to plasmonic interferometry for glucose sensing

    Science.gov (United States)

    Siu, Vince S.; Feng, Jing; Flanigan, Patrick W.; Palmore, G. Tayhas R.; Pacifici, Domenico

    2014-06-01

    A non-invasive method for the detection of glucose is sought by millions of diabetic patients to improve personal management of blood glucose over a lifetime. In this work, the synergistic advantage of combining plasmonic interferometry with an enzyme-driven dye assay yields an optical sensor capable of detecting glucose in saliva with high sensitivity and selectivity. The sensor, coined a "plasmonic cuvette," is built around a nano-scale groove-slit-groove (GSG) plasmonic interferometer coupled to an Amplex-red/Glucose-oxidase/Glucose (AR/GOx/Glucose) assay. The proposed device is highly sensitive, with a measured intensity change of 1.7×105%/m (i.e., one order of magnitude more sensitive than without assay) and highly specific for glucose sensing in picoliter volumes, across the physiological range of glucose concentrations found in human saliva (20-240 ?m). Real-time glucose monitoring in saliva is achieved by performing a detailed study of the underlying enzyme-driven reactions to determine and tune the effective rate constants in order to reduce the overall assay reaction time to ˜2 min. The results reported suggest that by opportunely choosing the appropriate dye chemistry, a plasmonic cuvette can be turned into a general, real-time sensing scheme for detection of any molecular target, with high sensitivity and selectivity, within extremely low volumes of biological fluid (down to femtoliters). Hereby, we present the results on glucose detection in artificial saliva as a notable and clinically relevant case study.

  17. The glucose-dependent insulinotropic polypeptide and glucose-stimulated insulin response to exercise training and diet in obesity

    DEFF Research Database (Denmark)

    Kelly, Karen R; Brooks, Latina M

    2009-01-01

    Aging and obesity are characterized by decreased beta-cell sensitivity and defects in the potentiation of nutrient-stimulated insulin secretion by GIP. Exercise and diet are known to improve glucose metabolism and the pancreatic insulin response to glucose, and this effect may be mediated through the incretin effect of GIP. The purpose of this study was to assess the effects of a 12-wk exercise training intervention (5 days/wk, 60 min/day, 75% Vo(2 max)) combined with a eucaloric (EX, n = 10) or hypocaloric (EX-HYPO, pre: 1,945 +/- 190, post: 1,269 +/- 70, kcal/day; n = 9) diet on the GIP response to glucose in older (66.8 +/- 1.5 yr), obese (34.4 +/- 1.7 kg/m(2)) adults with impaired glucose tolerance. In addition to GIP, plasma PYY(3-36), insulin, and glucose responses were measured during a 3-h, 75-g oral glucose tolerance test. Both interventions led to a significant improvement in Vo(2 max) (P <0.05). Weight loss (kg) was significant in both groups but was greater after EX-HYPO (-8.3 +/- 1.1 vs. -2.8 +/-0.5, P = 0.002). The glucose-stimulated insulin response was reduced after EX-HYPO (P = 0.02), as was the glucose-stimulated GIP response (P <0.05). Furthermore, after the intervention, changes in insulin (DeltaI(0-30)/DeltaG(0-30)) and GIP (Delta(0-30)) secretion were correlated (r = 0.69, P = 0.05). The PYY(3-36) (Delta(0-30)) response to glucose was increased after both interventions (P <0.05). We conclude that 1) a combination of caloric restriction and exercise reduces the GIP response to ingested glucose, 2) GIP may mediate the attenuated glucose-stimulated insulin response after exercise/diet interventions, and 3) the increased PYY(3-36) response represents an improved capacity to regulate satiety and potentially body weight in older, obese, insulin-resistant adults.

  18. PHYSICO-CHEMICAL PROPERTIES OF MAGNESIUM IONIC LIQUID ANALOGOUS

    Directory of Open Access Journals (Sweden)

    Huaiyou Wang

    2012-01-01

    Full Text Available In this paper, the solubility of Choline chloride (ChCl in ethylene glycol (EG was measured by isothermal method in the temperature range between 0°C and 120°C. The solubility of MgCl2 in saturated ChCl-EG mixture was measured by isothermal method at 20°C, 50°C and 70°C, respectively. Ionic liquid analogous containing MgCl2 was prepared based on the measured solubility data. The structure of the ionic liquid analogous is preliminarily investigated by Fourier transform infrared spectroscopy. The physical and electrochemical properties of the ionic liquid such as viscosity, conductivity, molar conductivity and density were measured as function of temperature and compositions. It was found that magnesium ionic liquid analogous was highly conducting and low viscosity. The ChCl and MgCl2 had a great effect on the studied properties.

  19. PHYSICO-CHEMICAL PROPERTIES OF MAGNESIUM IONIC LIQUID ANALOGOUS

    Scientific Electronic Library Online (English)

    Huaiyou, Wang; Yongzhong, Jia; Xiaohua, Wang; Jun, Ma; Yan, Jing.

    1208-12-01

    Full Text Available In this paper, the solubility of Choline chloride (ChCl) in ethylene glycol (EG) was measured by isothermal method in the temperature range between 0°C and 120°C. The solubility of MgCl2 in saturated ChCl-EG mixture was measured by isothermal method at 20°C, 50°C and 70°C, respectively. Ionic liquid [...] analogous containing MgCl2 was prepared based on the measured solubility data. The structure of the ionic liquid analogous is preliminarily investigated by Fourier transform infrared spectroscopy. The physical and electrochemical properties of the ionic liquid such as viscosity, conductivity, molar conductivity and density were measured as function of temperature and compositions. It was found that magnesium ionic liquid analogous was highly conducting and low viscosity. The ChCl and MgCl2 had a great effect on the studied properties.

  20. Learning Analogies and Semantic Relations

    CERN Document Server

    Turney, P D; Turney, Peter D.; Littman, Michael L.

    2003-01-01

    We present an algorithm for learning from unlabeled text, based on the Vector Space Model (VSM) of information retrieval, that can solve verbal analogy questions of the kind found in the Scholastic Aptitude Test (SAT). A verbal analogy has the form A:B::C:D, meaning "A is to B as C is to D"; for example, mason:stone::carpenter:wood. SAT analogy questions provide a word pair, A:B, and the problem is to select the most analogous word pair, C:D, from a set of five choices. The VSM algorithm correctly answers 47% of a collection of 374 college-level analogy questions (random guessing would yield 20% correct). We motivate this research by relating it to work in cognitive science and linguistics, and by applying it to a difficult problem in natural language processing, determining semantic relations in noun-modifier pairs. The problem is to classify a noun-modifier pair, such as "laser printer", according to the semantic relation between the noun (printer) and the modifier (laser). We use a supervised nearest-neigh...

  1. Crows spontaneously exhibit analogical reasoning.

    Science.gov (United States)

    Smirnova, Anna; Zorina, Zoya; Obozova, Tanya; Wasserman, Edward

    2015-01-19

    Analogical reasoning is vital to advanced cognition and behavioral adaptation. Many theorists deem analogical thinking to be uniquely human and to be foundational to categorization, creative problem solving, and scientific discovery. Comparative psychologists have long been interested in the species generality of analogical reasoning, but they initially found it difficult to obtain empirical support for such thinking in nonhuman animals (for pioneering efforts, see [2, 3]). Researchers have since mustered considerable evidence and argument that relational matching-to-sample (RMTS) effectively captures the essence of analogy, in which the relevant logical arguments are presented visually. In RMTS, choice of test pair BB would be correct if the sample pair were AA, whereas choice of test pair EF would be correct if the sample pair were CD. Critically, no items in the correct test pair physically match items in the sample pair, thus demanding that only relational sameness or differentness is available to support accurate choice responding. Initial evidence suggested that only humans and apes can successfully learn RMTS with pairs of sample and test items; however, monkeys have subsequently done so. Here, we report that crows too exhibit relational matching behavior. Even more importantly, crows spontaneously display relational responding without ever having been trained on RMTS; they had only been trained on identity matching-to-sample (IMTS). Such robust and uninstructed relational matching behavior represents the most convincing evidence yet of analogical reasoning in a nonprimate species, as apes alone have spontaneously exhibited RMTS behavior after only IMTS training. PMID:25532894

  2. Infrared spectra of lunar soil analogs. [spectral reflectance of minerals

    Science.gov (United States)

    Aronson, J. R.

    1977-01-01

    The infrared spectra of analogs of lunar soils were investigated to further the development of methodology for interpretation of remotely measured infrared spectra of the lunar surface. The optical constants of dunite, bytownite, augite, ilmenite, and a mare glass analog were obtained. The infrared emittance spectra of powdered minerals were measured and compared with spectra calculated by the reflectance theory using a catalog of optical constants. The results indicate that the predictions of the theory closely simulate the experimental measurements if the optical constants are properly derived.

  3. PHYSICO-CHEMICAL PROPERTIES OF MAGNESIUM IONIC LIQUID ANALOGOUS

    OpenAIRE

    Huaiyou Wang; Yongzhong Jia; Xiaohua Wang; Jun Ma; Yan Jing

    2012-01-01

    In this paper, the solubility of Choline chloride (ChCl) in ethylene glycol (EG) was measured by isothermal method in the temperature range between 0°C and 120°C. The solubility of MgCl2 in saturated ChCl-EG mixture was measured by isothermal method at 20°C, 50°C and 70°C, respectively. Ionic liquid analogous containing MgCl2 was prepared based on the measured solubility data. The structure of the ionic liquid analogous is preliminarily investigated by Fourier transform infrared spectros...

  4. Silicon-based nanochannel glucose sensor

    CERN Document Server

    Wang, Xihua; Gibney, Katherine A; Erramilli, Shyamsunder; Mohanty, Pritiraj

    2008-01-01

    Silicon nanochannel biological field effect transistors have been developed for glucose detection. The device is nanofabricated from a silicon-on-insulator wafer with a top-down approach and surface functionalized with glucose oxidase. The differential conductance of silicon nanowires, tuned with source-drain bias voltage, is demonstrated to be sensitive to the biocatalyzed oxidation of glucose. The glucose biosensor response is linear in the 0.5-8 mM concentration range with 3-5 min response time. This silicon nanochannel-based glucose biosensor technology offers the possibility of high density, high quality glucose biosensor integration with silicon-based circuitry.

  5. KETONES SUPPRESS BRAIN GLUCOSE CONSUMPTION

    OpenAIRE

    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 ?-hydroxybutyrate (?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; ?M/min/100g) was calculated in the cortex and cerebellum of control and ketotic rats using Patlak analysis. Rats were imaged on a rodent PET...

  6. Polarization sensitive optical low-coherence reflectometry for blood glucose monitoring in human subjects

    Science.gov (United States)

    Solanki, Jitendra; Choudhary, Om Prakash; Sen, P.; Andrews, J. T.

    2013-07-01

    A device based on polarization sensitive optical low-coherence reflectometry is developed to monitor blood glucose levels in human subjects. The device was initially tested with tissue phantom. The measurements with human subjects for various glucose concentration levels are found to be linearly dependent on the ellipticity obtainable from the home-made phase-sensitive optical low-coherence reflectometry device. The linearity obtained between glucose concentration and ellipticity are explained with theoretical calculations using Mie theory. A comparison of results with standard clinical methods establishes the utility of the present device for non-invasive glucose monitoring.

  7. Glucose sensing in human epidermis using mid-infrared photoacoustic detection

    OpenAIRE

    Kottmann, Jonas; Rey, Julien M.; Luginbühl, Joachim; Reichmann, Ernst; Markus W. Sigrist

    2012-01-01

    No reliable non-invasive glucose monitoring devices are currently available. We implemented a mid-infrared (MIR) photoacoustic (PA) setup to track glucose in vitro in deep epidermal layers, which represents a significant step towards non-invasive in vivo glucose measurements using MIR light. An external-cavity quantum-cascade laser (1010–1095 cm?1) and a PA cell of only 78 mm3 volume were employed to monitor glucose in epidermal skin. Skin samples are characterized by a high water content...

  8. Glucose sensing in human epidermis using mid-infrared photoacoustic detection

    OpenAIRE

    Kottmann, Jonas; Rey, Julien M.; Luginbühl, Joachim; Reichmann, Ernst; Markus W. Sigrist

    2012-01-01

    No reliable non-invasive glucose monitoring devices are currently available. We implemented a mid-infrared (MIR) photoacoustic (PA) setup to track glucose in vitro in deep epidermal layers, which represents a significant step towards non-invasive in vivo glucose measurements using MIR light. An external-cavity quantum-cascade laser (1010-1095 cm(-1)) and a PA cell of only 78 mm(3) volume were employed to monitor glucose in epidermal skin. Skin samples are characterized by a high water content...

  9. Non-Invasive Glucose Monitoring Techniques: A review and current trends

    CERN Document Server

    Poddar, Raju; Shukla, Pratyoosh; Sen, Pratima

    2008-01-01

    Diabetes mellitus is a complex group of syndromes that have in common a disturbance in the body's use of glucose, resulting in an elevated blood sugar. Once detected, sugar diabetes can be controlled by an appropriate regimen that should include diet therapy, a weight reduction program for those persons who are overweight, a program of exercise and insulin injections or oral drugs to lower blood glucose. Blood glucose monitoring by the patient and the physician is an important aspect in the control of the devastating complications (heart disease, blindness, kidney failure or amputations) due to the disease. Intensive therapy and frequent glucose testing has numerous benefits. With ever improving advances in diagnostic technology, the race for the next generation of bloodless, painless, accurate glucose instruments has begun. In this paper, we reviewed various methods, techniques and approaches successfully demonstrated for measuring or monitoring blood glucose. Invasive, minimally invasive and noninvasive tec...

  10. Insulin secretion and incretin hormones after oral glucose in non-obese subjects with impaired glucose tolerance

    DEFF Research Database (Denmark)

    Rask, E; Olsson, T

    2004-01-01

    Subjects with impaired glucose tolerance (IGT) are usually overweight and exhibit insulin resistance with a defective compensation of insulin secretion. In this study, we sought to establish the interrelation between insulin secretion and insulin sensitivity after oral glucose in non-obese subjects with IGT and we also examined this interrelation in relation to the 2 main incretins, glucagon-like peptide (GLP-1) and gastric inhibitory polypeptide (GIP). To that end, 13 women with IGT and 17 women with normal glucose tolerance (NGT) underwent an oral glucose tolerance test (OGTT) with measurements of glucose, insulin, C-peptide, GLP-1, and GIP. Insulin secretion (TIS) and insulin sensitivity (OGIS) were assessed using models describing the relationship between glucose, insulin and C-peptide data. These models allowed estimation also of the hepatic extraction of insulin. The age (54.2 +/- 9.7 [mean +/- SD] years) and body mass index (BMI; 26.0 +/- 4.0 kg/m(2)) did not differ between the groups. Subjects with IGT displayed lower TIS during the initial 30 minutes after oral glucose (0.97 +/- 0.17 [mean +/- SEM] v 1.75 +/- 0.23 nmol/L in NGT; P =.018) and lower OGIS (397 +/- 21 v 463 +/- 12 mL/min/m(2); P =.005). The incremental 30-minute TIS times OGIS (reflecting insulin secretion in relation to insulin sensitivity) was significantly reduced in IGT (359 +/- 51 v 774 +/- 91 nmol/min/m(2), P =.001). This measure correlated inversely to the 2-hour glucose level (r = -0.71; P <.001). In contrast, TIS over the whole 180-minute period was higher in IGT (26.2 +/- 2.4 v 20.0 +/- 2.0 nmol/L; P =.035). Hepatic insulin extraction correlated linearly with OGIS (r = 0.71; P <.001), but was not significantly different between the groups although there was a trend with lower extraction in IGT (P =.055). Plasma levels of GLP-1 and GIP increased after oral glucose. Total secretion of these incretin hormones during the 3-hour test did not differ between the 2 groups. However, the 30-minute increase in GLP-1 concentrations was lower in IGT than in NGT (P =.036). We conclude that also in non-obese subjects with IGT, when adiposity is controlled for in relation to NGT, defective early insulin secretion after oral glucose is a key factor. This defective beta-cell function is associated with, and may be caused by, a reduced early GLP-1 response.

  11. Cell-to-cell diffusion of glucose in the mammalian heart is disrupted by high glucose. Implications for the diabetic heart.

    Science.gov (United States)

    De Mello, Walmor C

    2015-06-10

    The cell-to-cell diffusion of glucose in heart cell pairs isolated from the left ventricle of adult Wistar Kyoto rats was investigated. For this, fluorescent glucose was dialyzed into one cell of the pair using the whole cell clamp technique, and its diffusion from cell-to-cell was investigated by measuring the fluorescence in the dialyzed as well as in non-dialyzed cell as a function of time. The results indicated that: 1) glucose flows easily from cell-to-cell through gap junctions; 2) high glucose solution (25mM) disrupted chemical communication between cardiac cells and abolished the intercellular diffusion of glucose; 3) the effect of high glucose solution on the cell-to-cell diffusion of glucose was drastically reduced by Bis-1 (10(-9)M) which is a PKC inhibitor; 4) intracellular dialysis of Ang II (100nM) or increment of intracellular calcium concentration (10(-8)M) also inhibited the intercellular diffusion of glucose; 5) high glucose enhances oxidative stress in heart cells; 6) calculation of gap junction permeability (Pj) (cm/s) indicated a value of 0.74±0.08×10(-4)cm/s (5 animals) for the controls and 0.4±0.001×10(-5)cm/s; n=35 (5 animals) (P0.05); 8) increase of intracellular Ca(2+) concentration (10(-8)M) drastically decreased Pj (Pj=0.3±0.003×10(-5)cm/s). Conclusions indicate that: 1) glucose flows from cell-to-cell in the heart through gap junctions; 2) high glucose (25mM) inhibited the intercellular diffusion of glucose-an effect significantly reduced by PKC inhibition; 3) high intracellular Ca(2+) concentration abolished the cell-to-cell diffusion of glucose; 4) intracellular Ang II (100nM) inhibited the intercellular diffusion of glucose indicating that intracrine Ang II, in part activated by high glucose, severely impairs the exchange of glucose between cardiac myocytes. These observations support the view that the intracrine renin angiotensin system is a modulator of chemical communication in the heart. The implications of these findings for the diabetic heart were discussed. PMID:25678369

  12. Modulation of parathion toxicity by glucose feeding: Is nitric oxide involved?

    International Nuclear Information System (INIS)

    Glucose feeding can markedly exacerbate the toxicity of the anticholinesterase insecticide, parathion. We determined the effects of parathion on brain nitric oxide and its possible role in potentiation of toxicity by glucose feeding. Adult rats were given water or 15% glucose in water for 3 days and challenged with vehicle or parathion (18 mg/kg, s.c.) on day 4. Functional signs, plasma glucose and brain cholinesterase, citrulline (an indicator of nitric oxide production) and high-energy phosphates (HEPs) were measured 1-3 days after parathion. Glucose feeding exacerbated cholinergic toxicity. Parathion increased plasma glucose (15-33%) and decreased cortical cholinesterase activity (81-90%), with no significant differences between water and glucose treatment groups. In contrast, parathion increased brain regional citrulline (40-47%) and decreased HEPs (18-40%) in rats drinking water, with significantly greater changes in glucose-fed rats (248-363% increase and 31-61% decrease, respectively). We then studied the effects of inhibiting neuronal nitric oxide synthase (nNOS) by 7-nitroindazole (7NI, 30 mg/kg, i.p. x4) on parathion toxicity and its modulation by glucose feeding. Co-exposure to parathion and 7NI led to a marked increase in cholinergic signs of toxicity and lethality, regardless of glucose intake. Thus, glucose feeding enhanced the accumulation of brain nitric oxide following parathion exposure, but inhibition of nitric oxide synthesis was ineffective at couric oxide synthesis was ineffective at counteracting increased parathion toxicity associated with glucose feeding. Evidence is therefore presented to suggest that nitric oxide may play both toxic and protective roles in cholinergic toxicity, and its precise contribution to modulation by glucose feeding requires further investigation

  13. Glucose utilisation in the lungs of septic rats

    International Nuclear Information System (INIS)

    Sequestration and degranulation of leucocytes in the pulmonary microcirculation is considered to be a key event in the development of acute respiratory distress syndrome in patients with sepsis. Glucose serves as the main source of energy in activated leucocytes. The aim of this study was to assess whether glucose utilisation in the lungs can be used as an indicator of pulmonary leucocyte accumulation in an experimental model of sepsis of intra-abdominal origin. Sepsis was induced in rats by abdominal implantation of a gelatine capsule containing bacteria and rat colonic contents. Empty gelatine capsules were implanted in control animals. Animals were studied 6 and 12 h after sepsis induction. Glucose utilisation was measured as the tissue uptake of fluorine-18-fluorodeoxyglucose (18FDG) 1 h after intravenous injection of the tracer. Micro-autoradiography was also performed after injection of tritiated deoxyglucose. We found increased uptake of 18FDG in the lungs of septic animals. The uptake also increased with time after sepsis induction. 18FDG uptake in circulating leucocytes was increased in septic animals compared with controls, and micro-autoradiography showed intense accumulation of deoxyglucose in leucocytes in the lungs of septic animals. We conclude that glucose utilisation is increased in the lungs of septic rats. Measurements of pulmonary glucose utilisation as an index of leucocyte metabolic activity may open new possibili metabolic activity may open new possibilities for studies of the pathophysiology of sepsis and for evaluation of therapeutic interventions. (orig.)

  14. Sugarcoated isolation: evidence that social avoidance is linked to higher basal glucose levels and higher consumption of glucose

    Science.gov (United States)

    Ein-Dor, Tsachi; Coan, James A.; Reizer, Abira; Gross, Elizabeth B.; Dahan, Dana; Wegener, Meredyth A.; Carel, Rafael; Cloninger, Claude R.; Zohar, Ada H.

    2015-01-01

    Objective: The human brain adjusts its level of effort in coping with various life stressors as a partial function of perceived access to social resources. We examined whether people who avoid social ties maintain a higher fasting basal level of glucose in their bloodstream and consume more sugar-rich food, reflecting strategies to draw more on personal resources when threatened. Methods: In Study 1 (N = 60), we obtained fasting blood glucose and adult attachment orientations data. In Study 2 (N = 285), we collected measures of fasting blood glucose and adult attachment orientations from older adults of mixed gender, using a measure of attachment style different from Study 1. In Study 3 (N = 108), we examined the link between trait-like attachment avoidance, manipulation of an asocial state, and consumption of sugar-rich food. In Study 4 (N = 115), we examined whether manipulating the social network will moderate the effect of attachment avoidance on consumption of sugar-rich food. Results: In Study 1, fasting blood glucose levels corresponded with higher attachment avoidance scores after statistically adjusting for time of assessment and interpersonal anxiety. For Study 2, fasting blood glucose continued to correspond with higher adult attachment avoidance even after statistically adjusting for interpersonal anxiety, stress indices, age, gender, social support and body mass. In Study 3, people high in attachment avoidance consume more sugar-rich food, especially when reminded of asocial tendencies. Study 4 indicated that after facing a stressful task in the presence of others, avoidant people gather more sugar-rich food than more socially oriented people. Conclusion: Results are consistent with the suggestion that socially avoidant individuals upwardly adjust their basal glucose levels and consume more glucose-rich food with the expectation of increased personal effort because of limited access to social resources. Further investigation of this link is warranted. PMID:25954240

  15. A highly performing electrochemiluminescent biosensor for glucose based on a polyelectrolyte-chitosan modified electrode

    International Nuclear Information System (INIS)

    A highly performing ECL glucose biosensor was developed by immobilizing glucose oxidase (GOD) onto a membrane modified glassy carbon electrode, which was prepared by using poly(diallyldimethylammonium chloride) (PDDA) doped with chitosan. In order to obtain the optimal performance of the ECL biosensor, the composition of modified membranes and a series of measurement conditions were investigated. Under the optimal conditions, this ECL biosensor was able to detect glucose in the range of 0.5-4.0 x 104 nM with a detection limit of 0.1 nM (defined as the concentration that could be detected at the signal-to-noise ratio of 3). The relative standard deviation was 0.99% for 5 x 10-8 mol/L glucose in repetitive measurements in the primary 12 potential cycles. This ECL biosensor offered the effectively improved stability of the electron transfer mediator and exhibited excellent properties for the ultrasensitive and selective determination of glucose with good reproducibility and stability. The present biosensor has also been used to determine the glucose concentrations in real serum samples. The recovery value for the assay of glucose ranged from 96.2 to 107% in the serum samples. The present biosensor displayed both specificity for glucose and retention of signal response even in a complex environment. Therefore, it provided an approach to the sensitive determination of glucose.

  16. Escherichia coli and its application in a mediated amperometric glucose sensor.

    Science.gov (United States)

    Ito, Yosuke; Yamazaki, Shin-ichi; Kano, Kenji; Ikeda, Tokuji

    2002-12-01

    Escherichia coli cells, which contain apo-glucose dehydrogenase, were used in constructing a mediated amperometric glucose sensor. The E. coli modified glucose sensor, which was prepared by immobilizing E. coli cells behind a dialysis membrane on a carbon paste electrode containing 2,3-dimethoxy-5-methyl-1,4-benzoquinone (Q(0)), produced a current for the electrocatalytic oxidation of glucose with Q(0) as an electron transfer mediator only after the addition of a trace amount of pyrroloquinoline quinone (PQQ), the cofactor of the enzyme. This allows a novel method of glucose measurements free from the interference of the redox active substances, if contained, in a sample solution. The glucose sensor was insensitive to dioxygen; the currents measured under anaerobic and aerobic conditions, and even under dioxygen saturated conditions were almost the same in magnitude at a given concentration of glucose over the range of 0.2-10 mM. Response time of the glucose sensor was 2 min to attain 90% level of the steady-state current. The E. coli modified glucose sensor was reusable when treated with ethylenediaminetetraacetic acid (EDTA). When E. coli cells were lyophilized, they could be stored at room temperature in a dry box for more than six months without loss of the catalytic activity. PMID:12392948

  17. Impact of Partial Pressure of Oxygen in Blood Samples on the Performance of Systems for Self-Monitoring of Blood Glucose

    OpenAIRE

    Schmid, Christina; Baumstark, Annette; Pleus, Stefan; Haug, Cornelia; Tesar, Martina; Freckmann, Guido

    2014-01-01

    Background: The partial pressure of oxygen (pO2) in blood samples can affect glucose measurements with oxygen-sensitive systems. In this study, we assessed the influence of different pO2 levels on blood glucose (BG) measurements with five glucose oxidase (GOD) systems and one glucose dehydrogenase (GDH) system. All selected GOD systems were indicated by the manufacturers to be sensitive to increased oxygen content of the blood sample.

  18. ADCs to DACs (analog-to-digital and digital-to-analog converters)

    CERN Document Server

    Pickering, J

    2006-01-01

    ADCs and DACs are crucial components in the relentless drive to replace analog circuitry with more controllable and less costly digital processing. This paper reviews the technologies available for measurement and control as applied to accelerators. It covers much of the terminology and ‘specmanship’ together with an application-oriented analysis of the performance to be expected of the various types. Finally, some guidance on system integration problems is given.

  19. Combining Basal Insulin Analogs with Glucagon-Like Peptide-1 Mimetics

    OpenAIRE

    Perfetti, Riccardo

    2011-01-01

    Basal insulin analogs are recognized as an effective method of achieving and maintaining glycemic control for patients with type 2 diabetes. However, the progressive nature of the disease means that some individuals may require additional ways to maintain their glycemic goals. Intensification in these circumstances has traditionally been achieved by the addition of short-acting insulin to cover postprandial glucose excursions that are not targeted by basal insulin. However, intensive insulin ...

  20. Impact of glucose excursion and mean glucose concentration in oral glucose-tolerance test on oxidative stress among Japanese Americans

    OpenAIRE

    Nakanishi S.; Yoneda M; Maeda S

    2013-01-01

    Shuhei Nakanishi, Masayasu Yoneda, Shusaku Maeda Department of Molecular and Internal Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan Aim: To evaluate the impact of glucose excursion (GE) and mean glucose concentration (MGC) on oxidative stress among persons with or without diabetes. Materials and methods: We examined 775 Japanese Americans who had normal glucose tolerance (NGT), impaired glucose tolerance, or diabetes according to the 75 g ...

  1. The proton spin crisis: an electroweak analogy

    International Nuclear Information System (INIS)

    We pose a problem analogous to the spin crisis within the electroweak theory. It is shown that the forward matrix elements of j?B, the baryonic current, do not only measure the generally understood baryon number but also include a helicity dependent W-boson piece due to the anomaly. The anomalous contribution is explicitly calculated for the W-boson and the electron. We also demonstrate the correct procedure to extract the anomalous W-boson contribution to the forward matrix element of j+B. ((orig.))

  2. Polarization Sensitive Optical Coherence Tomography for Blood Glucose Monitoring in Human Subjects

    CERN Document Server

    Solanki, Jitendra; Sen, Pratima; Andrews, Joseph Thomas

    2012-01-01

    A device based on Polarization sensitive optical coherence tomography is developed to monitor blood glucose levels in human subjects. The device was initially tested with tissue phantom. The measurements with human subjects for various glucose concentration levels are found to be linearly dependent on the degree of circular polarization obtainable from the PS-OCT.

  3. Kinetic Parameters for the Noncatalyzed and Enzyme-Catalyzed Mutarotation of Glucose Using a Blood Glucometer

    Science.gov (United States)

    Hardee, John R.; Delgado, Bryan; Jones, Wray

    2011-01-01

    The kinetic parameters for the conversion of alpha-D-glucose to beta-D-glucose were measured using a blood glucometer. The reaction order, rate constant, and Arrhenius activation energy are reported for the noncatalyzed reaction and turnover number and Michaelis constant are reported for the reaction catalyzed by porcine kidney mutarotase. The…

  4. Passive Diffusion of Transdermal Glucose: Noninvasive Glucose Sensing Using a Fluorescent Glucose Binding Protein.

    Science.gov (United States)

    Kanjananimmanont, Sunsanee; Ge, Xudong; Mupparapu, KarunaSri; Rao, Govind; Potts, Russell; Tolosa, Leah

    2014-01-21

    The motivation for this study was to determine if a statistically significant correlation exists between blood glucose (BG) and transdermal glucose (TG) collected by passive diffusion. A positive outcome will indicate that noninvasive passive TG diffusion is a painless alternative to collecting blood through a break on the skin. Sampling involves placing a small volume of buffer solution on the surface of membrane or skin for 5 minutes. The sample is then assayed with fluorescent GBP. In vitro testing was done on regenerated cellulose and a porcine skin model to determine diffusion of standard glucose solutions. In vivo testing was done on a healthy subject and a subject with type 2 diabetes. Glucose diffused readily through the regenerated cellulose membrane with good correlation between surface and internal glucose concentrations (R (2) = .997). But the porcine skin model required a surface prewash to achieve the same good correlation R (2) = .943). Based on this, an optimum prewash step was determined for the in vivo studies. The resulting correlation coefficients between TG and BG after a 15-minute prewash in a healthy subject and type 2 subject were .87 and .93, respectively. Removal of the extraneous glucose in the skin by prewashing was an important step in achieving good correlation between TG and BG. The results suggest that passive collection of TG is a noninvasive alternative to current practice of breaking the skin. Further studies are under way to determine the lag time between TG and BG and for the sampling protocol to be more amenable to point-of-care application. PMID:24876581

  5. Arctigenin suppresses unfolded protein response and sensitizes glucose deprivation-mediated cytotoxicity of cancer cells.

    Science.gov (United States)

    Sun, Shengrong; Wang, Xiong; Wang, Changhua; Nawaz, Ahmed; Wei, Wen; Li, Juanjuan; Wang, Lijun; Yu, De-Hua

    2011-01-01

    The involvement of unfolded protein response (UPR) activation in tumor survival and resistance to chemotherapies suggests a new anticancer strategy targeting UPR pathway. Arctigenin, a natural product, has been recently identified for its antitumor activity with selective toxicity against cancer cells under glucose starvation with unknown mechanism. Here we found that arctigenin specifically blocks the transcriptional induction of two potential anticancer targets, namely glucose-regulated protein-78 (GRP78) and its analog GRP94, under glucose deprivation, but not by tunicamycin. The activation of other UPR pathways, e.g., XBP-1 and ATF4, by glucose deprivation was also suppressed by arctigenin. A further transgene experiment showed that ectopic expression of GRP78 at least partially rescued arctigenin/glucose starvation-mediated cell growth inhibition, suggesting the causal role of UPR suppression in arctigenin-mediated cytotoxicity under glucose starvation. These observations bring a new insight into the mechanism of action of arctigenin and may lead to the design of new anticancer therapeutics. PMID:20717870

  6. Glucagon-like peptide-1 (GLP-1) raises blood-brain glucose transfer capacity and hexokinase activity in human brain

    DEFF Research Database (Denmark)

    Jensen, Michael Gejl; Lerche, Susanne

    2013-01-01

    In hyperglycemia, glucagon-like peptide-1 (GLP-1) lowers brain glucose concentration together with increased net blood-brain clearance and brain metabolism, but it is not known whether this effect depends on the prevailing plasma glucose (PG) concentration. In hypoglycemia, glucose depletion potentially impairs brain function. Here, we test the hypothesis that GLP-1 exacerbates the effect of hypoglycemia. To test the hypothesis, we determined glucose transport and consumption rates in seven healthy men in a randomized, double-blinded placebo-controlled cross-over experimental design. The acute effect of GLP-1 on glucose transfer in the brain was measured by positron emission tomography (PET) during a hypoglycemic clamp (3 mM plasma glucose) with (18)F-fluoro-2-deoxy-glucose (FDG) as tracer of glucose. In addition, we jointly analyzed cerebrometabolic effects of GLP-1 from the present hypoglycemia study and our previous hyperglycemia study to estimate the Michaelis-Menten constants of glucose transport and metabolism. The GLP-1 treatment lowered the vascular volume of brain tissue. Loading data from hypo- to hyperglycemia into the Michaelis-Menten equation, we found increased maximum phosphorylation velocity (V max) in the gray matter regions of cerebral cortex, thalamus, and cerebellum, as well as increased blood-brain glucose transport capacity (T max) in gray matter, white matter, cortex, thalamus, and cerebellum. In hypoglycemia, GLP-1 had no effects on net glucose metabolism, brain glucose concentration, or blood-brain glucose transport. Neither hexokinase nor transporter affinities varied significantly with treatment in any region. We conclude that GLP-1 changes blood-brain glucose transfer and brain glucose metabolic rates in a PG concentration-dependent manner. One consequence is that hypoglycemia eliminates these effects of GLP-1 on brain glucose homeostasis.

  7. Hypothalamic neurones governing glucose homeostasis.

    Science.gov (United States)

    Coppari, R

    2015-06-01

    The notion that the brain directly controls the level of glucose in the blood (glycaemia) independent of its known action on food intake and body weight has been known ever since 1849. That year, the French physiologist Dr Claude Bernard reported that physical puncture of the floor of the fourth cerebral ventricle rapidly leads to an increased level of sugar in the blood (and urine) in rabbits. Despite this important discovery, it took approximately 150 years before significant efforts aimed at understanding the underlying mechanism of brain-mediated control of glucose metabolism were made. Technological developments allowing for genetically-mediated manipulation of selected molecular pathways in a neurone-type-specific fashion unravelled the importance of specific molecules in specific neuronal populations. These neuronal pathways govern glucose metabolism in the presence and even in the absence of insulin. Also, a peculiarity of these pathways is that certain biochemically-defined neurones govern glucose metabolism in a tissue-specific fashion. PMID:25778859

  8. Glucose sensor with improved haemocompatibilty.

    Science.gov (United States)

    Yang, Y; Zhang, S F; Kingston, M A; Jones, G; Wright, G; Spencer, S A

    2000-08-01

    A new biocompatible copolymer has been synthesised and used in an electrochemical enzyme-based glucose sensor. The copolymer incorporates three segments including a monomer with an electrically neutral phosphorylcholine head group that is able to reject protein adsorption and two segments that increase the affinity to polyurethane substrate. Peel and solution circulation tests showed that this material has high attachment to polyurethane. With the new copolymer as the outermost layer and the polyurethane as the diffusion-limiting membrane, the sensor showed extended linearity up to 50 mM glucose and stable output in bovine serum for 70 h. During in vivo tests, the sensor exhibited a steady current signal and a rapid transient response when the glucose concentration was raised. These results imply that the haemocompatibility of the glucose sensor coated with the new copolymer has been improved, which is crucial for a sensor used for clinical real-time monitoring. The material may also be suitable for application to other implantable devices. PMID:11219733

  9. Glucose-6-Phosphate Dehydrogenase Deficiency Overview

    Science.gov (United States)

    ... Rare Diseases Information Center (GARD) Print friendly version Glucose-6-phosphate dehydrogenase deficiency Table of Contents Overview ... of the National Institutes of Health. Overview Listen Glucose 6 phosphate dehydrogenase (G6PD) deficiency is a hereditary ...

  10. Glucose Effect in the Acute Porphyrias

    Science.gov (United States)

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

  11. Demographic and metabolic characteristics of individuals with progressive glucose tolerance

    Directory of Open Access Journals (Sweden)

    A.L. Mendes

    2009-03-01

    Full Text Available We evaluated changes in glucose tolerance of 17 progressors and 62 non-progressors for 9 years to improve our understanding of the pathogenesis of type 2 diabetes mellitus. Changes in anthropometric measurements and responses to an oral glucose tolerance test (OGTT were analyzed. We identified 14 pairs of individuals, one from each group, who were initially normal glucose tolerant and were matched for gender, age, weight, and girth. We compared initial plasma glucose and insulin curves (from OGTT, insulin secretion (first and second phases and insulin sensitivity indices (from hyperglycemic clamp assay for both groups. In the normal glucose tolerant phase, progressors presented: 1 a higher OGTT blood glucose response with hyperglycemia in the second hour and a similar insulin response vs non-progressors; 2 a reduced first-phase insulin secretion (2.0 ± 0.3 vs 2.3 ± 0.3 pmol/L; P < 0.02 with a similar insulin sensitivity index and a lower disposition index (3.9 ± 0.2 vs 4.1 ± 0.2 µmol·kg-1·min-1 ; P < 0.05 vs non-progressors. After 9 years, both groups presented similar increases in weight and fasting blood glucose levels and progressors had an increased glycemic response at 120 min (P < 0.05 and reduced early insulin response to OGTT (progressors, 1st: 2.10 ± 0.34 vs 2nd: 1.87 ± 0.25 pmol/mmol; non-progressors, 1st: 2.15 ± 0.28 vs 2nd: 2.03 ± 0.39 pmol/mmol; P < 0.05. Theses data suggest that ?-cell dysfunction might be a risk factor for type 2 diabetes mellitus.

  12. Glucose challenge increases circulating progenitor cells in Asian Indian male subjects with normal glucose tolerance which is compromised in subjects with pre-diabetes: A pilot study

    Directory of Open Access Journals (Sweden)

    Bairagi Soumi

    2011-01-01

    Full Text Available Abstract Background Haematopoietic stem cells undergo mobilization from bone marrow to blood in response to physiological stimuli such as ischemia and tissue injury. The aim of study was to determine the kinetics of circulating CD34+ and CD133+CD34+ progenitor cells in response to 75 g glucose load in subjects with normal and impaired glucose metabolism. Methods Asian Indian male subjects (n = 50 with no prior history of glucose imbalance were subjected to 2 hour oral glucose tolerance test (OGTT. 24 subjects had normal glucose tolerance (NGT, 17 subjects had impaired glucose tolerance (IGT and 9 had impaired fasting glucose (IFG. The IGT and IFG subjects were grouped together as pre-diabetes group (n = 26. Progenitor cell counts in peripheral circulation at fasting and 2 hour post glucose challenge were measured using direct two-color flow cytometry. Results The pre-diabetes group was more insulin resistant (p + cells (p = 0.003 and CD133+CD34+ (p = 0.019 cells was seen 2 hours post glucose challenge in the NGT group. This increase for both the cell types was attenuated in subjects with IGT. CD34+ cell counts in response to glucose challenge inversely correlated with neutrophil counts (? = -0.330, p = 0.019, while post load counts of CD133+CD34+ cells inversely correlated with serum creatinine (? = -0.312, p = 0.023. Conclusion There is a 2.5-fold increase in the circulating levels of haematopoietic stem cells in response to glucose challenge in healthy Asian Indian male subjects which is attenuated in subjects with pre-diabetes.

  13. Appetite Sensations, Appetite Signaling Proteins, and Glucose in Obese Adolescents with Subclinical Binge Eating Disorder

    OpenAIRE

    Adamo, Kristi B.; Wilson, Shanna L.; Ferraro, Zachary M.; Hadjiyannakis, Stasia; Doucet, E?ric; Goldfield, Gary S.

    2014-01-01

    Objective. This study aimed to investigate potential differences in appetite sensations, ghrelin, peptide YY, and glucose and their relationship with energy and macronutrient intake in obese adolescents with subclinical binge eating disorder. Methods. Fifteen obese adolescents (six and nine individuals with and without subclinical binge eating disorder, resp.) qualified for this study. Visual analog scales and Three-Factor Eating Questionnaires were used to assess eating behaviours. Circulati...

  14. Direct conversion of glucose to 5-(hydroxymethyl)furfural in ionic liquids with lanthanide catalysts

    DEFF Research Database (Denmark)

    Ståhlberg, Tim; SØrensen, Mathilde Grau

    2010-01-01

    The direct conversion of glucose to 5-(hydroxymethyl)furfural (HMF) in ionic liquids with lanthanide catalysts was examined in search of a possibly more environmentally feasible process not involving chromium. The highest HMF yield was obtained with ytterbium chloride or triflate together with alkylimidazolium chlorides. Notably, a higher reactivity was observed when the hydrophobicity of the imidazolium cation was increased, in contrast to analogous chromium catalyst systems. This indicates a different reaction mechanism for the lanthanides than for the chromium catalyst systems.

  15. Fat distribution and glucose intolerance among Greenland inuit

    DEFF Research Database (Denmark)

    JØrgensen, Marit Eika; Borch-Johnsen, Knut

    2013-01-01

    OBJECTIVE A high amount of subcutaneous fat is suggested to explain the observation of lower obesity-associated metabolic risk among Inuit than among Europeans. We examined the association between measures of obesity (visceral adipose tissue [VAT], subcutaneous adipose tissue [SAT], BMI, waist circumference [WC], and percentage of body fat) and the indices of glucose metabolism (fasting and 2-h glucose levels, insulin resistance per homeostasis model assessment [HOMA-IR], and the insulin sensitivity index [ISI0,120]) among Greenland Inuit. RESEARCH DESIGN AND METHODS A total of 3,108 adult Inuit participated in a population-based study. The examination included a 75-g oral glucose tolerance test and anthropometric measurements. VAT and SAT were measured by ultrasound according to a validated protocol. Information on sociodemographic characteristics and health behaviors was obtained by interview. RESULTS Mean SATs were 1.8 and 3.5 cm in men and women, respectively. Mean VATs were 7.0 and 6.3 cm in men and women, respectively. The total prevalence of type 2 diabetes was 9%. Percentage of body fat generally was most strongly associated with all outcomes. Both SAT and VAT were significantly associated with glucose intolerance, fasting and 2-h plasma glucose levels, HOMA-IR, and ISI0,120. VAT was more strongly associated with all outcomes than was SAT. After further adjustment for BMI or WC, VAT was associated with glucose intolerance and insulin resistance, whereas there was a trend toward a negative or no association with SAT. CONCLUSIONS High mean values of SAT may to a large extent explain the high WC in Inuit populations, and this is suggested to contribute to the lower observed metabolic risk for a given level of obesity.

  16. Glucose signalling positively regulates aliphatic glucosinolate biosynthesis

    OpenAIRE

    Miao, Huiying; Wei, Jia; Zhao, Yanting; Yan, Huizhuan; Sun, Bo; Huang, Jirong; WANG, QIAOMEI

    2013-01-01

    The effects of glucose on aliphatic glucosinolate biosynthesis in Arabidopsis thaliana were investigated in this study by using mutants related to aliphatic glucosinolate biosynthesis and regulation, as well as glucose signalling. The results showed that glucose significantly increased the contents of individual and total aliphatic glucosinolates. Expression of MYB28 and MYB29, two key transcription factors in aliphatic glucosinolate biosynthesis, was also induced by glucose. Consistently, th...

  17. Analog Input Data Acquisition Software

    Science.gov (United States)

    Arens, Ellen

    2009-01-01

    DAQ Master Software allows users to easily set up a system to monitor up to five analog input channels and save the data after acquisition. This program was written in LabVIEW 8.0, and requires the LabVIEW runtime engine 8.0 to run the executable.

  18. Paper Analogies Enhance Biology Teaching.

    Science.gov (United States)

    Stencel, John E.

    1997-01-01

    Describes how to use paper analogies as models to illustrate various concepts in biology, human anatomy, and physiology classes. Models include biochemical paper models, protein papergrams, a paper model of early brain development, and a 3-D paper model of a eukaryotic cell. (AIM)

  19. Mathematical Analogy and Metaphorical Insight

    Science.gov (United States)

    Zwicky, Jan

    2010-01-01

    How are we to understand the power of certain literary metaphors? The author argues that the apprehension of good metaphors is importantly similar to the apprehension of fruitful mathematical analogies: both involve a structural realignment of vision. The author then explores consequences of this claim, drawing conceptually significant parallels…

  20. Glucose oligomers as models to elucidate the starch radiolysis mechanism

    International Nuclear Information System (INIS)

    A comparative study of gamma irradiated glucose and glucose oligomers has been carried out in order to find a suitable model to understand the mechanism of starch radiolysis. Measurements of malonaldehyde and formic acid, produced by irradiation, showed that the quantitative comparison of radiolytic products was not significant for our purpose, which was also confirmed by a literature survey. However, an electron spin resonance kinetic study of several oligomers, irradiated in the powder state, showed that maltopentaose, and to a lesser extent, maltotriose, may be used as models in the radiolysis of starch. (orig.)