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1

?-Bromophosphonate analogs of glucose-6-phosphate are inhibitors of glucose-6-phosphatase.  

UK PubMed Central (United Kingdom)

Glucose-6-phosphatase (G6Pase) is an essential metabolic enzyme that has upregulated activity in Type II diabetes. Synthetic analogs of the G6Pase substrate, glucose-6-phosphate (G6P), may provide new tools to probe enzyme activity, or lead to specific inhibitors of glycosylphosphatase enzymes. Here we have developed synthetic routes to a panel of non-hydrolyzable G6P analogs containing ?-bromo, ?,?-dibromo, and ?-bromo-?,?-unsaturated phosphonates compatible with a carbohydrate nucleus. We confirm that these functionalities have potency as inhibitors of G6Pase in vitro, providing a series of new phosphate isosteres that can be exploited for inhibitor design.

Downey AM; Cairo CW

2013-11-01

2

?-Bromophosphonate analogs of glucose-6-phosphate are inhibitors of glucose-6-phosphatase.  

Science.gov (United States)

Glucose-6-phosphatase (G6Pase) is an essential metabolic enzyme that has upregulated activity in Type II diabetes. Synthetic analogs of the G6Pase substrate, glucose-6-phosphate (G6P), may provide new tools to probe enzyme activity, or lead to specific inhibitors of glycosylphosphatase enzymes. Here we have developed synthetic routes to a panel of non-hydrolyzable G6P analogs containing ?-bromo, ?,?-dibromo, and ?-bromo-?,?-unsaturated phosphonates compatible with a carbohydrate nucleus. We confirm that these functionalities have potency as inhibitors of G6Pase in vitro, providing a series of new phosphate isosteres that can be exploited for inhibitor design. PMID:24095944

Downey, A Michael; Cairo, Christopher W

2013-08-11

3

An Analysis of How to Measure Glucose during Glucose Clamps: Are Glucose Meters Ready for Research?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

This article provides a perspective on the challenges of appropriate glucose measurement in the context of glucose clamp experiments. In a first step, the core outcome parameters of a clamp experiment, the blood glucose target level, and the glucose infusion rate will be identified. The relation of ...

Hompesch, Marcus; Rave, Klaus

4

Positron emission tomographic measurements of cerebral glucose utilization using [1-11C]D-glucose  

International Nuclear Information System (INIS)

[en] Regional CMRglc was measured in seven healthy volunteers with positron emission tomography using [1-11C]D-glucose. Regional CBF was measured using [11C]fluoromethane. The arteriovenous differences of unlabeled glucose and oxygen together with 11C metabolites were also measured. In addition to the loss of [11C]CO2, a loss of acidic 11C metabolites was also detected. A three-compartment model was applied to the tracer data in the time interval 0-24 min. After correction for the loss of 11C metabolites, the tracer method gave an average CMRglc of 26.4 +/- 1.9 (SD) mumol/100 g/min, close to the value obtained with the Fick principle. After correction for the loss of [11C]CO2 only, the tracer method gave 23.6 +/- 2.1 mumol/100 g/min, compatible with (1/6) CMRO2, obtained with the Fick principle. These results and the time course of the loss of acidic 11C metabolites are consistent with the presence of nonoxidative metabolism of glucose that causes an early loss of mainly [11C]lacetate after a bolus injection of the tracer. This implies that [1-11C]D-glucose measures the rate of glucose oxidation rather than the total CMRglc. The experiments using [1-11C]D-glucose were compared to five analogous experiments using [U-11C]D-glucose together with [15O]H2O as a flow tracer. After correction for the loss of [11C]CO2, the two glucose tracers gave similar global values of CMRglc and other parameters associated with glucose utilization, but with labeling in the carbon-1 position, the loss of [11C]CO2 was substantially delayed and the contrast between gray and white matter was improved

1990-01-01

5

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

P536, a UDP-glucose analog which was previously described as an antiviral agent (M. J. Camaraza, P. Fernández Resa, M. T. García López, F. G. de las Heras, P. P. Mendez-Castrillón, B. Alarcón, and L. Carrasco, J. Med. Chem. 28:40-46, 1985), has a potent and selective activity against the intracellul...

Alcina, A; Fresno, M; Alarcón, B

6

Blood glucose measurements in critically ill patients.  

UK PubMed Central (United Kingdom)

Studies on tight glycemic control by intensive insulin therapy abruptly changed the climate of limited interest in the problem of hyperglycemia in critically ill patients and reopened the discussion on accuracy and reliability of glucose sensor devices. This article describes important components of blood glucose measurements and their interferences with the focus on the intensive care unit setting. Typical methodologies, organized from analytical accuracy to clinical accuracy, to assess imprecision and bias of a glucose sensor are also discussed. Finally, a list of recommendations and requirements to be considered when evaluating (time-discrete) glucose sensor devices is given.

Van Herpe T; Mesotten D

2012-01-01

7

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

Science.gov (United States)

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 sensitivity has an advantage in the drug discovery process. Thus, there is a need to develop a new effective method of differentiating the pre adipocytes to adipocytes and to use such methods for developing efficacious therapeutic molecules. We observed that a combination of Dexamethasone and Troglitazone generated differentiated adipocytes over fewer days as compared to the combination of IBMX and Dexamethasone which constitutes the standard protocol followed in our laboratory. The experiments conducted to compare the quality of differentiation yielded by various differentiating agents indicated that the lipid droplet accumulation increased by 112 % and the GLUT4 mediated glucose uptake by 137 % in cells differentiated with Troglitazone and Dexamethasone than in cells differentiated traditionally. The comparative studies conducted for evaluating efficient measurable glucose uptake by GOPOD assay, radioactive (3)H-2-deoxy-D-glucose assay and by non-radioactive 6-NBDG (fluorescent analog of glucose) indicated that the non-radioactive method using 6-NBDG showed a higher signal to noise ratio than the conventional indirect glucose uptake method (GOPOD assay) and the radioactive (3)H-2-deoxy-D-glucose uptake method. Differentiated 3T3 L1 cells when triggered with 2.5 ng/mL of Insulin showed 3.3 fold more glucose uptake in non-radioactive method over the radioactive (3)H-2-deoxy-D-glucose uptake method. The results of this study have suggested that a combination of Dexamethasone and Troglitazone for 3T3 L1 cell differentiation helps in better quality differentiation over a short period of time with increased sensitivity to Insulin. The application of these findings for developing new methods of screening novel Insulin mimetics and for evaluating the immunological responses has been discussed. PMID:23292944

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

2013-01-06

8

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

UK PubMed Central (United Kingdom)

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 sensitivity has an advantage in the drug discovery process. Thus, there is a need to develop a new effective method of differentiating the pre adipocytes to adipocytes and to use such methods for developing efficacious therapeutic molecules. We observed that a combination of Dexamethasone and Troglitazone generated differentiated adipocytes over fewer days as compared to the combination of IBMX and Dexamethasone which constitutes the standard protocol followed in our laboratory. The experiments conducted to compare the quality of differentiation yielded by various differentiating agents indicated that the lipid droplet accumulation increased by 112 % and the GLUT4 mediated glucose uptake by 137 % in cells differentiated with Troglitazone and Dexamethasone than in cells differentiated traditionally. The comparative studies conducted for evaluating efficient measurable glucose uptake by GOPOD assay, radioactive (3)H-2-deoxy-D-glucose assay and by non-radioactive 6-NBDG (fluorescent analog of glucose) indicated that the non-radioactive method using 6-NBDG showed a higher signal to noise ratio than the conventional indirect glucose uptake method (GOPOD assay) and the radioactive (3)H-2-deoxy-D-glucose uptake method. Differentiated 3T3 L1 cells when triggered with 2.5 ng/mL of Insulin showed 3.3 fold more glucose uptake in non-radioactive method over the radioactive (3)H-2-deoxy-D-glucose uptake method. The results of this study have suggested that a combination of Dexamethasone and Troglitazone for 3T3 L1 cell differentiation helps in better quality differentiation over a short period of time with increased sensitivity to Insulin. The application of these findings for developing new methods of screening novel Insulin mimetics and for evaluating the immunological responses has been discussed.

Vishwanath D; Srinivasan H; Patil MS; Seetarama S; Agrawal SK; Dixit MN; Dhar K

2013-06-01

9

Non-Invasive Optical Blood Glucose Measurement  

Directory of Open Access Journals (Sweden)

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.

Megha C.Pande

2013-01-01

10

A review of metabolism of labeled glucoses for use in measuring glucose recycling  

International Nuclear Information System (INIS)

[en] The fate of tritium from each carbon of D-glucose and the metabolism of L-glucose and 2-deoxy-D-glucose are known. Differences in metabolism of labeled glucoses can be used to quantify physical and chemical recycling of glucose. Only physical recycling is measured by [1-3H]-L-glucose, whereas [U-14C]-D-glucose measures total recycling. The difference between [1-3H]-L-glucose and [U-14C]-D-glucose, therefore, is chemical recycling. Recycling from extracellular binding sites and hepatic glucose 6-phosphate can be measured by difference between [1,2-3H]-2-deoxy-D-glucose and [1-3H]-L-glucose, and the difference in irreversible loss of the two will measure extrahepatic uptake of D-glucose. Recycling via Cori-alanine cycle plus CO2 is the difference in irreversible loss measured by using [6-3H]-glucose and [U-14C]-D-glucose. Recycling via the hexose monophosphate pathway can be determined by difference in irreversible loss between [1-3H]-D-glucose and [6-3H]-D-glucose. Recycling via CO2 and glycerol must be measured directly with [U-14C]glucose, bicarbonate, and glycerol. Recycling via hepatic glycogen can be estimated by subtracting all other measured chemical recycling from total chemical recycling. This review describes means to quantify glucose recycling in vivo, enabling studies of mechanisms for conservation and utilization of glucose. 54 references

1990-01-01

11

Child-friendly blood glucose measuring device  

UK PubMed Central (United Kingdom)

The measuring system (110) has a measuring instrument (112), particularly a commercial measuring instrument for detecting analytes in a body fluid. The measuring instrument is arranged as portable hand device and has housing with an indicator element. A toy (128), particularly a play figure or a play animal is provided, where toy has a receiver (132) for reversible receiving of the measuring instrument. Independent claims are included for the following: (1) a toy, particularly play figure or play toy, particularly for application in a measuring system (2) a kit for detecting analyte in a body fluid, particularly for detecting analyte in blood glucose and (3) a method for producing a measuring system, for detecting analyte in a body fluid.

KLINKE MARTIN; HOFMANN DIETER

12

Capillary and venous blood glucose measurements using a direct glucose-sensing meter.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The aim of the study was to evaluate the precision and accuracy of the ExacTech home blood glucose meter when used with either capillary or venous blood and to compare this with a reference whole blood glucose assay. Non-fasting glucose measurements were used since a validation study showed no capil...

Matthews, DR; Burton, SF; Bown, E; Chusney, G; Dornan, T; Gale, EA

13

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

Energy Technology Data Exchange (ETDEWEB)

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 (TVS)methionine, (TH)thymidine, (TH)mannose, ( UC)-N-acetylglucosamine, and (TH)uridine into macromolecules by T. cruzi epimastigotes, the last being the most sensitive.

Alcina, A.; Fresno, M.; Alarcon, B.

1988-09-01

14

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.

1988-01-01

15

A Bell inequality analog in quantum measure theory  

International Nuclear Information System (INIS)

[en] One obtains Bell's inequalities if one posits a hypothetical joint probability distribution, or measure, whose marginals yield the probabilities produced by the spin measurements in question. The existence of a joint measure is in turn equivalent to a certain causality condition known as 'screening off'. We show that if one assumes, more generally, a joint quantal measure, or 'decoherence functional', one obtains instead an analogous inequality weaker by a factor of ?2. The proof of this 'Tsirel'son inequality' is geometrical and rests on the possibility of associating a Hilbert space to any strongly positive quantal measure. These results lead both to a question: 'Does a joint measure follow from some quantal analog of 'screening off'?', and to the observation that non-contextual hidden variables are viable in histories-based quantum mechanics, even if they are excluded classically

2007-01-19

16

Novel glucagon-like peptide-1 analog delivered orally reduces postprandial glucose excursions in porcine and canine models.  

UK PubMed Central (United Kingdom)

BACKGROUND: Glucagon-like peptide-1 (GLP-1) and its analogs are associated with a gamut of physiological processes, including induction of insulin release, support of normoglycemia, ?-cell function preservation, improved lipid profiles, and increased insulin sensitivity. Thus, GLP-1 harbors significant therapeutic potential for regulating type 2 diabetes mellitus, where its physiological impact is markedly impaired. To date, GLP-1 analogs are only available as injectable dosage forms, and its oral delivery is expected to provide physiological portal/peripheral concentration ratios while fostering patient compliance and adherence. METHODS: Healthy, fasting, enterically cannulated pigs and beagle canines were administered a single dose of the exenatide-based ORMD-0901 formulation 30 min before oral glucose challenges. Blood samples were collected every 15 min for evaluation of ORMD-0901 safety and efficacy in regulating postchallenge glucose excursions. RESULTS: Enterically delivered ORMD-0901 was well tolerated by all animals. ORMD-0901 formulations RG3 and AG2 led to reduced glucose excursions in pigs when delivered prior to a 5 g/kg glucose challenge, where area under the curve (AUC)0-120 values were up to 43% lower than in control sessions. All canines challenged with a glucose load with no prior exposure to exenatide, demonstrated higher AUC0-150 values than in their exenatide-treated sessions. Subcutaneous exenatide delivery amounted to a 51% reduction in mean glucose AUC0-150, while formulations AG4 and AG3 prompted 43% and 29% reductions, respectively. CONCLUSIONS: When delivered enterically, GLP-1 (ORMD-0901) is absorbed from the canine and porcine gastrointestinal tracts and retains its biological activity. Further development of this drug class in an oral dosage form is expected to enhance diabetes control and patient compliance.

Eldor R; Kidron M; Greenberg-Shushlav Y; Arbit E

2010-11-01

17

Flow cytomeric measurement of DNA and incorporated nucleoside-analogs  

Energy Technology Data Exchange (ETDEWEB)

This patent describes a non-radioactive method for measuring unaltered cellular DNA and incorporated nucleoside analog. The method comprises: growing a population of cells; altering a portion of the DNA of each cell; applying the immunochemical stain to the cells; applying the second stain to the cells; and detecting at substantially the same time and for each cell of a substantial portion of the population, a non-radioactive first signal from the immunochemical stain.

Dolbeare, F.A.; Gray, J.W.

1989-03-14

18

Fluorescence spectroscopy for noninvasive glucose measurement  

Science.gov (United States)

The interaction between gold nanoparticles and glucose and its effect on the fluorescence spectrum of nanoparticles were investigated experimentally. It was observed after this interaction the intensity of fluorescence peak becomes weaker and red shifted.

Bagheri, Z.; Massudi, R.; Ghanavi, J.; Latifi, H.

2013-06-01

19

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 hyperglycemia in the presence of basal insulin levels.

1987-01-01

20

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

Energy Technology Data Exchange (ETDEWEB)

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

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

1987-10-01

 
 
 
 
21

AMPLITUDE AND TIME MEASUREMENT ASIC WITH ANALOG DERANDOMIZATION.  

Energy Technology Data Exchange (ETDEWEB)

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.

O CONNOR,P.; DE GERONIMO,G.; KANDASAMY,A.

2002-11-10

22

Glucose measurement by surface plasmon resonance with borate polymer binding  

Science.gov (United States)

Minimally-invasive human blood glucose detection can be realized by measuring the glucose concentration of interstitial fluid to predict the blood glucose level. As the amount of transdermally extracted interstitial fluid was minimal and its composition was complex, a glucose measurement method by surface plasmon resonance (SPR) based on PAA-ran-PAAPBA polymer binding was proposed. The polymer was immobilized on the gold film of SPR sensor using layer-by-layer self-assembly technique to capture the glucose molecules in interstitial fluid to realize the detection of glucose concentration with high precision. 2~1000mg/dL glucose solutions were measured utilizing the SPR sensor by polymer binding. The fitting degrees were 0.90177 and 0.99509 in the range of 2~10mg/dL and 25~1000mg/dL respectively. The dynamic dissociation process of glucose molecules from PAA-ran-PAAPBA was verified to be able to satisfy the requirements of the human blood glucose continuous monitoring in clinics.

Li, Dachao; Yang, Jia; Wu, Peng; Yang, Di; Wang, Bo; Lin, Yuan; Xu, Kexin

2013-02-01

23

A Novel Long-Acting Glucose-Dependent Insulinotropic Peptide (GIP) Analog: Enhanced Efficacy in Normal and Diabetic Rodents.  

UK PubMed Central (United Kingdom)

AIM: Glucose-dependent insulinotropic peptide (GIP) is an incretin hormone that is released from intestinal K cells in response to nutrient ingestion. We aimed to investigate the therapeutic potential of the novel N- and C-terminally modified GIP analog AC163794. METHODS: AC163794 was synthesized by solid phase peptide synthesis. Design involved the substitution of the C-terminus tail region of the DPP-IV-resistant GIP analog [D-Ala(2) ]GIP(1-42) with the unique nine amino acid tail region of exenatide. The functional activity and binding of AC163794 to the GIP receptor were evaluated in RIN-m5F beta-cells. In vitro metabolic stability was tested in human plasma and kidney membrane preparations. Acute insulinotropic effects were investigated in isolated mouse islets and during an intravenous glucose tolerance test in normal and diabetic ZDF rats. The biological actions of AC163794 were comprehensively assessed in normal, ob/ob and high-fat-fed STZ-induced diabetic mice. Acute glucoregulatory effects of AC163794 were tested in diet-induced obese mice treated sub-chronically with AC3174, the exendatide analog ([Leu(14) ]exenatide. Human GIP or [D-Ala(2) ]GIP(1-42) were used for comparison. RESULTS: AC163794 exhibited nanomolar functional GIP receptor potency in vitro similar to GIP and [D-Ala(2) ]GIP(1-42). AC163794 was metabolically more stable in vitro and displayed longer duration of insulinotropic action in vivo versus GIP and [D-Ala(2) ]GIP(1-42). In diabetic mice, AC163794 improved HbA1c through enhanced insulinotropic action, partial restoration of pancreatic insulin content and improved insulin sensitivity with no adverse effects on fat storage and metabolism. AC163794 provided additional baseline glucose-lowering when injected to mice treated with AC3174. CONCLUSIONS: These studies support the potential use of a novel GIP analog AC163794 for the treatment of type 2 diabetes.

Tatarkiewicz K; Hargrove DM; Jodka CM; Gedulin BR; Smith PA; Hoyt JA; Lwin A; Collins L; Mamedova L; Levy OE; D'Souza L; Janssen S; Srivastava V; Ghosh SS; Parkes DG

2013-07-01

24

Clinical value of blood glucose measurement in pet rabbits.  

Science.gov (United States)

Blood glucose was measured with a portable glucose meter in 907 rabbits, including 238 clinically healthy ones. Blood glucose concentrations ranged from 1.2 to 30.1 mmol/l. Diabetes mellitus was not encountered. No significant effect of sex or sedation was found. Hypoglycaemia was seen in 16 rabbits including one with an insulinoma. There was a significant relationship between blood glucose, food intake, signs of stress and severity of clinical disease. Rabbits showing signs of stress had higher blood glucose than rabbits with no signs and rabbits that were totally anorexic had higher blood glucose values than those that were eating normally or those with reduced food intake. Severe hyperglycaemia (>20 mmol/l) was associated with conditions with a poor prognosis. Rabbits with confirmed intestinal obstruction had a mean blood glucose of 24.7 mmol/l (n=18). This was significantly higher than the rabbits with confirmed gut stasis, which had a mean value of 8.5 mmol/l (n=51). The conclusion of the study was that blood glucose is a measurable parameter that can be used to assess the severity of a rabbit's condition and help to differentiate between gut stasis and intestinal obstruction in rabbits that are anorexic. PMID:22659922

Harcourt-Brown, F M; Harcourt-Brown, S F

2012-06-01

25

Clinical value of blood glucose measurement in pet rabbits.  

UK PubMed Central (United Kingdom)

Blood glucose was measured with a portable glucose meter in 907 rabbits, including 238 clinically healthy ones. Blood glucose concentrations ranged from 1.2 to 30.1 mmol/l. Diabetes mellitus was not encountered. No significant effect of sex or sedation was found. Hypoglycaemia was seen in 16 rabbits including one with an insulinoma. There was a significant relationship between blood glucose, food intake, signs of stress and severity of clinical disease. Rabbits showing signs of stress had higher blood glucose than rabbits with no signs and rabbits that were totally anorexic had higher blood glucose values than those that were eating normally or those with reduced food intake. Severe hyperglycaemia (>20 mmol/l) was associated with conditions with a poor prognosis. Rabbits with confirmed intestinal obstruction had a mean blood glucose of 24.7 mmol/l (n=18). This was significantly higher than the rabbits with confirmed gut stasis, which had a mean value of 8.5 mmol/l (n=51). The conclusion of the study was that blood glucose is a measurable parameter that can be used to assess the severity of a rabbit's condition and help to differentiate between gut stasis and intestinal obstruction in rabbits that are anorexic.

Harcourt-Brown FM; Harcourt-Brown SF

2012-06-01

26

A New Digit Positioning Method for Analog Measuring Instruments  

Directory of Open Access Journals (Sweden)

Full Text Available For the automatic digit positioning of analogy measuring instruments, a positioning method based on coordinate transformation which has practical application is brought forward. And for the present, the mostly used ways for this field are method based on Hough transform and method based on circle scanning. But they have some defects such as time-consuming and complex or low accuracy rate. The method in this study is proposed to solve the above problems. It is primarily based on the coordinate transformation and projection operation to realize the object of digit positioning. By experiment, the validity and feasibility of the positioning method based on coordinate transformation are confirmed. It is shown that the average accuracy is improved by 5.4% and average positioning efficiency is improved by 8.73% compared to the present methods.

Zhenhua Wei; Le Zhang; Jie Lin; Shibo Song

2013-01-01

27

Clinical assessment of the accuracy of blood glucose measurement devices.  

UK PubMed Central (United Kingdom)

OBJECTIVES: Blood glucose meters for patient self-measurement need to comply with the accuracy standards of the ISO 15197 guideline. We investigated the accuracy of the two new blood glucose meters BG*Star and iBG*Star (Sanofi-Aventis) in comparison to four other competitive devices (Accu-Chek Aviva, Roche Diagnostics; FreeStyle Freedom Lite, Abbott Medisense; Contour, Bayer; OneTouch Ultra 2, Lifescan) at different blood glucose ranges in a clinical setting with healthy subjects and patients with type 1 and type 2 diabetes. BGStar and iBGStar are employ dynamic electrochemistry, which is supposed to result in highly accurate results. METHODS: The study was performed on 106 participants (53 female, 53 male, age (mean?±?SD): 46?±?16 years, type 1: 32 patients, type 2: 34 patients, and 40 healthy subjects). Two devices from each type and strips from two different production lots were used for glucose assessment (?200 readings/meter). Spontaneous glucose assessments and glucose or insulin interventions under medical supervision were applied to perform measurements in the different glucose ranges in accordance with the ISO 15197 requirements. Sample values <50?mg/dL and >400?mg/dL were prepared by laboratory manipulations. The YSI glucose analyzer (glucose oxidase method) served as the standard reference method which may be considered to be a limitation in light of glucose hexokinase-based meters. RESULTS: For all devices, there was a very close correlation between the glucose results compared to the YSI reference method results. The correlation coefficients were r?=?0.995 for BGStar and r?=?0.992 for iBGStar (Aviva: 0.995, Freedom Lite: 0.990, Contour: 0.993, Ultra 2: 0.990). Error-grid analysis according to Parkes and Clarke revealed both 100% of the readings to be within the clinically acceptable areas (Clarke: A?+?B with BG*Star (100?+?0), Aviva (97?+?3), and Contour (97?+?3); and 99.5% with iBG*Star (97.5?+?2), Freedom Lite (98?+?1.5), and Ultra 2 (97.5?+?2)). CONCLUSIONS: This study demonstrated the very high accuracy of BG*Star, iBG*Star, and the competitive blood glucose meters in a clinical setting.

Pfützner A; Mitri M; Musholt PB; Sachsenheimer D; Borchert M; Yap A; Forst T

2012-04-01

28

The relationships between common measures of glucose meter performance.  

UK PubMed Central (United Kingdom)

BACKGROUND: Glucose meter performance is commonly measured in several different ways, including the relative bias and coefficient of variation (CV), the total error, the mean absolute relative deviation (MARD), and the size of the interval around the reference value that would be necessary to contain a meter measurement at a specified probability. This fourth measure is commonly expressed as a proportion of the reference value and will be referred to as the necessary relative deviation. A deeper understanding of the relationships between these measures may aid health care providers, patients, and regulators in comparing meter performances when different measures are used. METHODS: The relationships between common measures of glucose meter performance were derived mathematically. RESULTS: Equations are presented for calculating the total error, MARD, and necessary relative deviation using the reference value, relative bias, and CV when glucose meter measurements are normally distributed. When measurements are also unbiased, the CV, total error, MARD, and necessary relative deviation are linearly related and are therefore equivalent measures of meter performance. CONCLUSIONS: The relative bias and CV provide more information about meter performance than the other measures considered but may be difficult for some audiences to interpret. Reporting meter performance in multiple ways may facilitate the informed selection of blood glucose meters.

Wilmoth DR

2012-09-01

29

Accuracy of blood glucose measurements using glucose meters and arterial blood gas analyzers in critically ill adult patients: systematic review.  

UK PubMed Central (United Kingdom)

INTRODUCTION: Glucose control to prevent both hyperglycemia and hypoglycemia is important in an intensive care unit. Arterial blood gas analyzers and glucose meters are commonly used to measure blood glucose concentration in an intensive care unit; however, their accuracies are still unclear. METHODS: We performed a systematic literature search (January 1, 2001 to August 31, 2012) to find clinical studies comparing blood glucose values measured by glucose meters and/or arterial blood gas analyzers with those simultaneously measured by a central laboratory machine in critically ill adult patients. RESULTS: We reviewed 879 articles and found 21 studies in which the accuracy of blood glucose monitoring by arterial blood gas analyzers and/or glucometers using central laboratory methods as references was assessed in critically ill adult patients. Of those 21 studies, 11 studies in which International Organization for Standardization criteria, error grid method or percentage of values within 20% of the error of a reference were used were selected for evaluation. The accuracy of blood glucose measurements by arterial blood gas analyzers and glucose meters using arterial blood was significantly higher than that of measurements by glucose meters using capillary blood (odds ratios for error: 0.04, p<0.001 and 0.36, p<0.001). The accuracy of blood glucose measurements by arterial blood gas analyzers tended to be higher than that of measurements by glucose meters using arterial blood (p=0.20). In the hypoglycemic range (defined as less than 81 mg/dL), the incidence of errors using these devices was higher than that in the non-hypoglycemic range (odds ratios for error: arterial blood gas analyzers: 1.86, p=0.15; glucose meters using capillary blood: 1.84, p=0.03; glucose meters using arterial blood: 2.33, p=0.02). Unstable hemodynamics (edema and use of a vasopressor) and use of insulin were associated with increased error of blood glucose monitoring using a glucose meters. CONCLUSIONS: Our literature review showed that the accuracy of blood glucose measurements by arterial blood gas analyzers was significantly higher than that of measurements by glucose meters using capillary blood and tended to be higher than that of measurements by glucose meters using arterial blood. These results should be interpreted with caution because of the large variation of accuracy among devices. Since blood glucose monitoring was less accurate within or near the hypoglycemic range, especially in patients with unstable hemodynamics or receiving insulin infusion, we should aware that current blood glucose monitoring technology has not reached a high enough degree of accuracy and reliability that leads to appropriate glucose control in critically ill patients.

Inoue S; Egi M; Kotani J; Morita K

2013-03-01

30

Effects of pramlintide, an analog of human amylin, on plasma glucose profiles in patients with IDDM: results of a multicenter trial.  

UK PubMed Central (United Kingdom)

The effects of subcutaneous administration of 10, 30, or 100 microg q.i.d. pramlintide, an analog of human amylin, on plasma glucose regulation in patients with IDDM were evaluated in a multicenter trial. The plasma glucose response to a Sustacal test meal was significantly reduced compared with placebo both after 1 week and after 2 weeks of administration of 30 or 100 microg pramlintide. In addition, 24-h mean plasma glucose concentrations were significantly lowered in patients receiving 30 microg of pramlintide for 2 weeks compared with placebo, while the 100-microg pramlintide dose did not reach statistical significance for the 24-h glucose profiles. At 10 microg, pramlintide had no effect on the 24-h glucose profile or on the plasma glucose response to a Sustacal test meal. The reduction in 24-h glucose concentrations and glucose concentrations after the Sustacal test meal observed at the 30-microg pramlintide dose was not accompanied by an increased incidence of hypoglycemic events. The most frequent adverse events were dose-related and involved transient upper gastrointestinal symptoms. A majority (>80%) of the patients who reported these adverse events during week 1 did not report them in week 2. These data indicate that pramlintide effectively reduces plasma glucose concentrations as reflected in both a 24-h glucose profile and a Sustacal test meal while maintaining an acceptable safety profile.

Thompson RG; Peterson J; Gottlieb A; Mullane J

1997-04-01

31

The effect of the insulin analog lispro on nighttime blood glucose control in type 1 diabetic patients.  

UK PubMed Central (United Kingdom)

OBJECTIVE: Unmodified regular insulin has a long absorption tail, unlike the fast-acting insulin analog lispro, and may contribute to hypoglycemia in the early part of the night. A randomized crossover double-blind study was performed to compare blood glucose concentrations in the early part of the night in type 1 diabetic patients receiving lispro or unmodified regular human insulin, in random order, on 2 separate study days. RESEARCH DESIGN AND METHODS: We studied 23 C-peptide-negative patients; 12 were using a premeal plus basal insulin regimen, and 11 were using twice-daily insulin injections. Patients were admitted to the investigation unit at 5:00 P.M. and received a single dose of lispro or unmodified regular human insulin before the evening meal. In both groups, the NPH insulin dose remained unchanged. Identical meals and snacks were eaten at the same time during both study days. RESULTS: Average postprandial (6:00-10:00 P.M.) blood glucose concentrations were significantly lower after lispro therapy compared with human insulin (7.1 +/- 0.4 [SE] vs. 8.5 +/- 0.4 mmol/l, P = 0.0002). Nighttime (midnight to 4:00 A.M.) blood glucose concentrations were significantly higher after lispro compared with human insulin (10.3 +/- 0.4 vs. 9.1 +/- 0.4 mmol/l, P = 0.02). This difference was greatest in patients on the premeal plus basal insulin regimen (11.6 +/- 0.5 vs. 8.7 +/- 0.4 mmol/l, P < 0.001). The incidence of nocturnal hypoglycemia (midnight to 4:00 A.M., blood glucose < 3.5 mmol/l) was less with lispro compared with unmodified insulin (1 vs. 6 patients, P = 0.04). Nighttime (midnight to 4:00 A.M.) 3-hydroxybutyrate (102 +/- 13 vs. 51 +/- 7 mumol/l, P = 0.000) and glycerol (52 +/- 3 vs. 42 +/- 2 mumol/l, P < 0.01) were significantly higher after lispro therapy compared with human insulin in patients on the premeal plus bolus insulin regimen. CONCLUSIONS: Lispro can improve postprandial blood glucose control and reduce the incidence of nocturnal hypoglycemia at the expense of nocturnal hyperglycemia and hyperketonemia in patients using a premeal plus basal insulin regimen.

Ahmed AB; Home PD

1998-01-01

32

Expression of human globular adiponectin-glucagon-like peptide-1 analog fusion protein and its assay of glucose-lowering effect in vivo.  

UK PubMed Central (United Kingdom)

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.

Zhao T; Lv J; Zhao J; Huang X; Xiao H

2011-01-01

33

Expression of human globular adiponectin-glucagon-like peptide-1 analog fusion protein and its assay of glucose-lowering effect in vivo.  

Science.gov (United States)

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. PMID:21448306

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

2011-03-04

34

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)

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.

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

2011-01-01

35

Effects of maternal ethanol ingestion on uptake of glucose alanine analogs in fetal rats  

International Nuclear Information System (INIS)

[en] The distribution of maternally-derived glucose and alanine has been studied in selected tissues of fetuses from ethanol-fed (EF) rats (30% of caloric intake throughout gestation). Controls received diet without ethanol by pair-feeding (PF) or ad libitum (AF). On the 22nd day of gestation, 2 ?Ci 3H 2-deoxyglucose (DG) and 1 ?Ci 14C ?-aminoisobutyric acid (AIB) were administered i.v. to each rat. One hour later, maternal blood, placenta, and fetal blood, liver, lung and brain were sampled for 3H and 14C activities. When compared to either control group, the mean 14C AIB activities of tissues from EF animals were reduced from 19 to 46%, with the greatest effect seen in the brain (3.7 +/- 0.1, 7.2 +/- 0.3 and 6.9 +/- 1.3 dpm/mg in EF, PF and AF fetuses respectively). In addition, the ratios of tissue:plasma 14C were reduced (p 3H 2-DG content of placenta (p

1986-01-01

36

Comparison of extracellular and net glucose oxidation measured isotopically and by indirect calorimetry during high and low glucose turnover  

International Nuclear Information System (INIS)

[en] To determine the extent to which glucose oxidation measured by indirect calorimetry reflects glucose oxidation measured isotopically, subjects were studied during a 6-h hyperinsulinemic euglycemic clamp (1 mU.kg-1.min-1) and during infusion of saline. [6-14C]glucose was infused on both occasions. Breath was collected for determination of the specific activity of carbon dioxide, oxygen consumption, and carbon dioxide production. Glucose turnover during hyperinsulinemia was approximately eightfold higher than during saline infusion. During the final 1.5 h of the hyperinsulinemic glucose clamp, oxidation measured isotopically remained slightly but consistently lower (P less than 0.05) than that measured by indirect calorimetry (13.8 +/- 1.1 vs 16.5 +/- 1.7 mumol.kg-1.min-1, respectively). In contrast, during the saline infusion, glucose oxidation measured isotopically did not differ from that measured by indirect calorimetry (8.3 +/- 0.6 vs 7.2 +/- 2.8 mumol.kg-1.min-1, respectively). We conclude that although net glucose oxidation measured isotopically was slightly lower than that measured by indirect calorimetry, both techniques provide similar estimates of glucose oxidation over a wide range of glucose disposal

1991-01-01

37

Effects of maternal ethanol ingestion on uptake of glucose alanine analogs in fetal rats  

Energy Technology Data Exchange (ETDEWEB)

The distribution of maternally-derived glucose and alanine has been studied in selected tissues of fetuses from ethanol-fed (EF) rats (30% of caloric intake throughout gestation). Controls received diet without ethanol by pair-feeding (PF) or ad libitum (AF). On the 22nd day of gestation, 2 ..mu..Ci /sup 3/H 2-deoxyglucose (DG) and 1 ..mu..Ci /sup 14/C ..cap alpha..-aminoisobutyric acid (AIB) were administered i.v. to each rat. One hour later, maternal blood, placenta, and fetal blood, liver, lung and brain were sampled for /sup 3/H and /sup 14/C activities. When compared to either control group, the mean /sup 14/C AIB activities of tissues from EF animals were reduced from 19 to 46%, with the greatest effect seen in the brain (3.7 +/- 0.1, 7.2 +/- 0.3 and 6.9 +/- 1.3 dpm/mg in EF, PF and AF fetuses respectively). In addition, the ratios of tissue:plasma /sup 14/C were reduced (p < 0.01 or lower) in the EF fetal tissues and placenta. Maternal ethanol ingestion reduced the /sup 3/H 2-DG content of placenta (p < 0.05) and of brain (38.6 + 1.2, 48.1 +/- 1.2 and 47.2 +/- 1.2 in EF, PF and AF, p < 0.001). Brain weight showed significant positive correlations with AIB content (r = 0.466, p < 0.001) and with 2-DG content (r = 0.267, p < 0.01). Impaired uptake of maternally-derived nutrients may play a significant role in the effects of ethanol in utero.

Snyder, A.K.; Singh, S.P.; Pullen, G.L.

1986-05-01

38

Fluorescence lifetime measurements of boronate derivatives to determine glucose concentration  

Energy Technology Data Exchange (ETDEWEB)

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.

Gable, J H

2000-06-01

39

Measurement of lactate formation from glucose using [6-3H]- and [6-14C]glucose in humans  

International Nuclear Information System (INIS)

[en] To assess the validity of determining the origin of plasma lactate from the ratio of lactate and glucose specific activities (SA) during infusion of labeled glucose, normal subjects received infusions of [6-3H]- and [6-14C]glucose for 4 h after a 12 h fast, and, on another day, cold glucose labeled with both tracers during 4-6 h of hyperinsulinemia (approximately 650 microU/ml). Basally, less lactate was derived from plasma glucose when measured with [6-3H]glucose (27 +/- 2%) than with [6-14C]glucose (40 +/- 2%, P less than 0.001). Insulin did not increase the percent of lactate derived from plasma glucose when measured with [6-3H]glucose (29 +/- 2%) but did increase when measured with [6-14C]glucose (60 +/- 4%). The arterialized blood (A) [3H]lactate SA was 30-40% higher (P less than 0.01) than deep venous blood (V) [3H]lactate SA, whereas A and V [14C]lactate SA were similar. During conversion of alanine to lactate with glutamic-pyruvic transaminase (GPT) and lactate dehydrogenase (LDH) in vitro, 32 +/- 2% of 3H in [3-3H]alanine was found in water and 68 +/- 2% in lactate. During infusion of [6-3H]- and [6-14C]glucose, the ratio of [14C]alanine to lactate SA (0.88 +/- 0.05) was less than the ratio of [3H]alanine to lactate SA (0.31 +/- 0.03, P less than 0.001). In conclusion (1) loss of 3H relative to 14C from position 6 in glucose occurs during lactate formation in extrahepatic tissues possibly due to the GPT reaction (alanine conversion to pyruvate), and (2) even under supraphysiologic hyperinsulinemic conditions not all of plasma lactate originates from plasma glucose

1990-01-01

40

Impact of prandial status on the comparison of capillary glucose meter and venous plasma glucose measurements in healthy volunteers.  

UK PubMed Central (United Kingdom)

BACKGROUND: There is a negative glucose gradient between the capillary and venous systems, produced by glucose uptake into peripheral tissues. This gradient is augmented by oral glucose ingestion in healthy volunteers; thus prandial status may impact on capillary glucose meter performance. Our primary aim was to investigate whether the (capillary-venous plasma) glucose difference changed in relation to prandial status, in healthy volunteers. METHODS: Glucose was measured fasting and also one hour after an ad libitum breakfast, in 103 healthy volunteers. Duplicate capillary (finger stick) measurements were undertaken at both time points, using both the FreeStyle Lite and AccuChek Performa meters. Simultaneous venous (antecubital fossa) samples were centrifuged immediately after collection and plasma glucose was measured using the laboratory hexokinase method. Results were compared by Bland-Altman difference analysis. RESULTS: The mean (95% CI) pre- and postprandial (capillary-plasma) glucose differences (mmol/L) were calculated for each meter. For the Freestyle Lite, the preprandial difference was -0.51 (-0.58 to -0.45) and postprandial difference was 0.81 (0.69-0.94). Corresponding differences for the Performa were -0.13 (-0.20 to -0.06) and 1.19 (1.07-1.31), respectively. T-test comparison of participants' paired pre- and postprandial (capillary-plasma) glucose differences confirmed a significant meal-related change in glucose estimation for both meters (P < 0.0001). Also, both meters read highest at lower glucose concentrations. CONCLUSIONS: In healthy volunteers, both glucose meters showed a systematic positive bias one hour after breakfast. The significance of this finding in diabetes remains to be determined.

Swaminathan A; Lunt H; Chang WS; Logan FJ; Frampton CM; Florkowski CM

2013-01-01

 
 
 
 
41

Blood glucose monitor: an alternative off-line method to measure glucose concentration during fermentations with Trichoderma reesei  

UK PubMed Central (United Kingdom)

Two home, blood-glucose monitoring meters, OneTouch Ultra and Ascensia Contour, were used to determine the glucose concentration during fermentations of Trichoderma reesei in both flasks and bioreactors. The results, when compared to those given by the 3,5-dinitrosalicylic acid reducing sugar assay, HPLC and YSI 2700 SELECT Biochemistry analyzer, showed that the glucose meters are a quick, reliable and economical alternative method for frequent glucose concentration measurement during fermentation. For T. reesei fermentations, the OneTouch meter was the more suitable

Choy Viviane; Patel Nilesh; Thibault Jules

2007-07-01

42

Blood glucose monitor: an alternative off-line method to measure glucose concentration during fermentations with Trichoderma reesei.  

UK PubMed Central (United Kingdom)

Two home, blood-glucose monitoring meters, OneTouch Ultra and Ascensia Contour, were used to determine the glucose concentration during fermentations of Trichoderma reesei in both flasks and bioreactors. The results, when compared to those given by the 3,5-dinitrosalicylic acid reducing sugar assay, HPLC and YSI 2700 SELECT Biochemistry analyzer, showed that the glucose meters are a quick, reliable and economical alternative method for frequent glucose concentration measurement during fermentation. For T. reesei fermentations, the OneTouch meter was the more suitable.

Choy V; Patel N; Thibault J

2007-07-01

43

Amplitude and time measurement ASIC with analog derandomization  

Energy Technology Data Exchange (ETDEWEB)

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 {mu}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.

O' Connor, P. E-mail: poc@bnl.gov; De Geronimo, G.; Kandasamy, A

2003-06-01

44

Screening for gestational diabetes by measuring fasting plasma glucose levels  

Science.gov (United States)

Objectives: (a) To test the sensitivity and specificity of measuring fasting plasma glucose levels (FPG) as a screening test for gestational diabetes mellitus (GDM). (b) To compare predicting levels of FPG levels with the one-hour, oral 50g non-fasting glucose challenge test (GCT) for predicting GDM. Methods: One thousand and six hundred pregnant women from the Health Centres, antenatal clinics and Salmaniya Medical Complex were screened by the GCT after 50g of oral glucose during 26–32 weeks gestation, giving a 13.5% incidence of GDM (using the Third International Workshop cutoff values of 7.8 mmol /l). All patients also had an FPG estimation followed by the three-hour oral glucose tolerance test (oGTT). Seventy eight percent of the patients were Bahraini, 19% Asian and 3% other nationalities. Their mean age was 27.2+0.2 years. Receiver-operating curves (ROC) were used to test the ability of the FPG and the oGTT to differentiate patients with GDM and identify the cut off values for predicting a diagnosis of GDM. Results: FPG levels of 5.6 mmol /l and 5.4 mmol /l yielded sensitivities and specificities of 94% and 93% respectively. Measuring FPG as a screening test required a diagnostic oGTT in 32% compared with 13% when the GCT was used. Conclusion: Using FPG levels at a cutoff value of ? 5.5 mmol /l is an easier, more acceptable test for patients compared to the GCT. Using the FPG levels is also more cost effective and allows nearly 70% of women to avoid the oGTT.

Rajab, Khalil E.; Skerman, Jonathan H.; Issa, Abdulla A.

2003-01-01

45

Insulin analogs  

Directory of Open Access Journals (Sweden)

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.

Emily Chu; Nicole Meinel; Martin Gilmour

2012-01-01

46

Hepatic glucose output in humans measured with labeled glucose to reduce negative errors  

Energy Technology Data Exchange (ETDEWEB)

Steele and others have suggested that minimizing changes in glucose specific activity when estimating hepatic glucose output (HGO) during glucose infusions could reduce non-steady-state errors. This approach was assessed in nondiabetic and type II diabetic subjects during constant low dose (27 mumol.kg ideal body wt (IBW)-1.min-1) glucose infusion followed by a 12 mmol/l hyperglycemic clamp. Eight subjects had paired tests with and without labeled infusions. Labeled infusion was used to compare HGO in 11 nondiabetic and 15 diabetic subjects. Whereas unlabeled infusions produced negative values for endogenous glucose output, labeled infusions largely eliminated this error and reduced the dependence of the Steele model on the pool fraction in the paired tests. By use of labeled infusions, 11 nondiabetic subjects suppressed HGO from 10.2 +/- 0.6 (SE) fasting to 0.8 +/- 0.9 mumol.kg IBW-1.min-1 after 90 min of glucose infusion and to -1.9 +/- 0.5 mumol.kg IBW-1.min-1 after 90 min of a 12 mmol/l glucose clamp, but 15 diabetic subjects suppressed only partially from 13.0 +/- 0.9 fasting to 5.7 +/- 1.2 at the end of the glucose infusion and 5.6 +/- 1.0 mumol.kg IBW-1.min-1 in the clamp (P = 0.02, 0.002, and less than 0.001, respectively).

Levy, J.C.; Brown, G.; Matthews, D.R.; Turner, R.C. (Nuffield Department of Clinical Medicine, Oxford (England))

1989-10-01

47

Non-invasive measurement of glucose uptake of skeletal muscle tissue models using a glucose nanobiosensor.  

Science.gov (United States)

Skeletal muscle tissues play a significant role to maintain the glucose level of whole body and any dysfunction of this tissue leads to the diabetes disease. A culture medium was created in which the muscle cells could survive for a long time and meanwhile it did not interfere with the glucose sensing. We fabricated a model of skeletal muscle tissues in vitro to monitor its glucose uptake. A nanoporous gold as a high sensitive nanobiosensor was then successfully developed and employed to detect the glucose uptake of the tissue models in this medium upon applying the electrical stimulation in a rapid, and non-invasive approach. The response of the glucose sensor was linear in a wide concentration range of 1-50mM, with a detection limit of 3?M at a signal-to-noise ratio of 3.0. The skeletal muscle tissue was electrically stimulated during 24h and glucose uptake was monitored during this period. During the first 3h of stimulation, electrically stimulated muscle tissue consumed almost twice the amount of glucose than counterpart non-stimulated sample. In total, the glucose consumption of muscle tissues was higher for the electrically stimulated tissues compared to those without applying the electrical field. PMID:23856563

Obregón, Raquel; Ahadian, Samad; Ramón-Azcón, Javier; Chen, Luyang; Fujita, Takeshi; Shiku, Hitoshi; Chen, Mingwei; Matsue, Tomokazu

2013-06-26

48

Hepatic glucose output in humans measured with labeled glucose to reduce negative errors  

International Nuclear Information System (INIS)

[en] Steele and others have suggested that minimizing changes in glucose specific activity when estimating hepatic glucose output (HGO) during glucose infusions could reduce non-steady-state errors. This approach was assessed in nondiabetic and type II diabetic subjects during constant low dose [27 mumol.kg ideal body wt (IBW)-1.min-1] glucose infusion followed by a 12 mmol/l hyperglycemic clamp. Eight subjects had paired tests with and without labeled infusions. Labeled infusion was used to compare HGO in 11 nondiabetic and 15 diabetic subjects. Whereas unlabeled infusions produced negative values for endogenous glucose output, labeled infusions largely eliminated this error and reduced the dependence of the Steele model on the pool fraction in the paired tests. By use of labeled infusions, 11 nondiabetic subjects suppressed HGO from 10.2 +/- 0.6 (SE) fasting to 0.8 +/- 0.9 mumol.kg IBW-1.min-1 after 90 min of glucose infusion and to -1.9 +/- 0.5 mumol.kg IBW-1.min-1 after 90 min of a 12 mmol/l glucose clamp, but 15 diabetic subjects suppressed only partially from 13.0 +/- 0.9 fasting to 5.7 +/- 1.2 at the end of the glucose infusion and 5.6 +/- 1.0 mumol.kg IBW-1.min-1 in the clamp (P = 0.02, 0.002, and less than 0.001, respectively)

1989-01-01

49

Flap salvage following postoperative venous thrombosis diagnosed by blood glucose measurement in the flaps.  

UK PubMed Central (United Kingdom)

Objective: This is the first paper to report the measurement of blood glucose in flaps to detect early flap congestion and flap salvage following immediate flap exploration. Methods: We performed blood glucose measurement in a superficial circumflex iliac artery perforator flap and an anterolateral thigh flap postoperatively using Medisafe-Mini (Terumo, Japan), a regular capillary blood glucose-monitoring device. Results: The blood glucose measurements were low when in early venous thrombosis. Low capillary blood glucose levels were detected early, even before flap discoloration occurred. Conclusions: Low capillary blood glucose level in congested flaps is an early sign of venous thrombosis. The incorporation of blood glucose measurement in addition to clinical monitoring aids in early detection and possible reduction postoperative complications due to venous thrombosis.

Hara H; Mihara M; Narushima M; Yamamoto T; Todokoro T; Araki J; Iida T; Koshima I; Shim TW

2011-01-01

50

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)

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

Torimoto Keiichi; Okada Yosuke; Mori Hiroko; Tanaka Yoshiya

2013-01-01

51

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 either issued by computer/processor or generated by circuit itself. (author)

2009-01-01

52

Measurement of the analogous Zeeman shift using a low-velocity intense source  

International Nuclear Information System (INIS)

[en] When a laser is circularly polarized and detuned between the D1 and D2 transitions of an alkali atom, the ac Stark shift on the atom can take the form of a pure Zeeman shift. We call it the analogous Zeeman effect. We used a low-velocity intense source of rubidium atoms and the stimulated Raman spectroscopy to measure the analogous Zeeman shift. We measured the Zeeman-like ac Stark shift for various wavelengths, polarization, and intensities of the pump laser, and found the result is in agreement with the theory. (author)

1999-01-01

53

Measurement of the analogous Zeeman shift using a low-velocity intense source  

Energy Technology Data Exchange (ETDEWEB)

When a laser is circularly polarized and detuned between the D1 and D2 transitions of an alkali atom, the ac Stark shift on the atom can take the form of a pure Zeeman shift. We call it the analogous Zeeman effect. We used a low-velocity intense source of rubidium atoms and the stimulated Raman spectroscopy to measure the analogous Zeeman shift. We measured the Zeeman-like ac Stark shift for various wavelengths, polarization, and intensities of the pump laser, and found the result is in agreement with the theory. (author)

Park, Chang Yong; Lee, Chung Mok; Oh, Eu Suk; Cho, D. [Korea University, Seoul (Korea, Republic of)

1999-07-01

54

Short-term diabetes blood glucose prediction based on blood glucose measurements.  

Science.gov (United States)

Insulin Dependent Diabetes Mellitus (IDDM) is a chronic disease characterized by the inability of the pancreas to produce sufficient amounts of insulin. Daily compensation of the deficiency requires 4-6 insulin injections to be taken daily, the aim of this insulin therapy being to maintain normoglycemia--i.e., a blood glucose level between 4-7 mmol/L. To determine the quantity and timing of these injections, various different approaches are used. Currently, mostly qualitative and semi-quantitative models and reasoning are used to design such a therapy. Here, an attempt is made to show how system identification and control may be used to estimate predictive quantitative models to be used in design of optimal insulin regimens. The system was divided into three subsystems, the insulin subsystem, the glucose subsystem and the insulin-glucose interaction. The insulin subsystem aims to describe the absorbtion of injected insulin from the subcutaneous depots and the glucose subsystem the absorbtion of glucose from the gut following a meal. These subsystems were modeled using compartment models and proposed models found in the literature. Several black-box models and grey-box models describing the insulin/glucose interaction were developed and analysed. These models were fitted to real data monitored by a IDDM patient. Many difficulties were encountered, typical of biomedical systems: Non-uniform and scarce sampling, time-varying dynamics and severe nonlinearities were some of the difficulties encountered during the modeling. None of the proposed models were able to describe the system accurately in all aspects during all conditions. However, all the linear models shared some dynamics. Based on the estimated models, short-term blood glucose predictors for up to two-hour-ahead blood glucose prediction were investigated. PMID:19162650

Ståhl, F; Johansson, R

2008-01-01

55

Short-term diabetes blood glucose prediction based on blood glucose measurements.  

UK PubMed Central (United Kingdom)

Insulin Dependent Diabetes Mellitus (IDDM) is a chronic disease characterized by the inability of the pancreas to produce sufficient amounts of insulin. Daily compensation of the deficiency requires 4-6 insulin injections to be taken daily, the aim of this insulin therapy being to maintain normoglycemia--i.e., a blood glucose level between 4-7 mmol/L. To determine the quantity and timing of these injections, various different approaches are used. Currently, mostly qualitative and semi-quantitative models and reasoning are used to design such a therapy. Here, an attempt is made to show how system identification and control may be used to estimate predictive quantitative models to be used in design of optimal insulin regimens. The system was divided into three subsystems, the insulin subsystem, the glucose subsystem and the insulin-glucose interaction. The insulin subsystem aims to describe the absorbtion of injected insulin from the subcutaneous depots and the glucose subsystem the absorbtion of glucose from the gut following a meal. These subsystems were modeled using compartment models and proposed models found in the literature. Several black-box models and grey-box models describing the insulin/glucose interaction were developed and analysed. These models were fitted to real data monitored by a IDDM patient. Many difficulties were encountered, typical of biomedical systems: Non-uniform and scarce sampling, time-varying dynamics and severe nonlinearities were some of the difficulties encountered during the modeling. None of the proposed models were able to describe the system accurately in all aspects during all conditions. However, all the linear models shared some dynamics. Based on the estimated models, short-term blood glucose predictors for up to two-hour-ahead blood glucose prediction were investigated.

Ståhl F; Johansson R

2008-01-01

56

Diffusion of D-glucose measured in the cytosol of a single astrocyte.  

UK PubMed Central (United Kingdom)

Astrocytes interact with neurons and endothelial cells and may mediate exchange of metabolites between capillaries and nerve terminals. In the present study, we investigated intracellular glucose diffusion in purified astrocytes after local glucose uptake. We used a fluorescence resonance energy transfer (FRET)-based nano sensor to monitor the time dependence of the intracellular glucose concentration at specific positions within the cell. We observed a delay in onset and kinetics in regions away from the glucose uptake compared with the region where we locally super-fused astrocytes with the D-glucose-rich solution. We propose a mathematical model of glucose diffusion in astrocytes. The analysis showed that after gradual uptake of glucose, the locally increased intracellular glucose concentration is rapidly spread throughout the cytosol with an apparent diffusion coefficient (D app) of (2.38 ± 0.41) × 10(-10) m(2) s(-1) (at 22-24 °C). Considering that the diffusion coefficient of D-glucose in water is D = 6.7 × 10(-10) m(2) s(-1) (at 24 °C), D app determined in astrocytes indicates that the cytosolic tortuosity, which hinders glucose molecules, is approximately three times higher than in aqueous solution. We conclude that the value of D app for glucose measured in purified rat astrocytes is consistent with the view that cytosolic diffusion may allow glucose and glucose metabolites to traverse from the endothelial cells at the blood-brain barrier to neurons and neighboring astrocytes.

Kreft M; Lukši? M; Zorec TM; Prebil M; Zorec R

2013-04-01

57

Evaluation of portable blood glucose meters for measurement of blood glucose concentration in ferrets (Mustela putorius furo).  

UK PubMed Central (United Kingdom)

OBJECTIVE: To evaluate agreement of 3 models of portable blood glucose meters (PBGMs; 2 designed for use with human samples and 1 designed for veterinary use) with a laboratory analyzer for measurement of blood glucose concentrations in ferrets (Mustela putorius furo). DESIGN: Evaluation study. ANIMALS: 52 ferrets. PROCEDURES: Samples were analyzed with 4 PBGMs (whole blood) and a laboratory analyzer (plasma). Two PBGMs of the model designed for veterinary use were tested; each was set to a code corresponding to canine or feline sample analysis throughout the study. Agreement and bias between measurements obtained with the PBGMs and the laboratory analyzer were assessed with Bland-Altman plots. Linear regression analysis was performed to evaluate associations with venipuncture site by comparison of central (jugular) and peripheral (lateral saphenous or cephalic) venous blood samples. RESULTS: Plasma glucose concentrations measured with the laboratory analyzer ranged from 41 to 160 mg/dL. Results from the PBGM for veterinary use coded to test a canine blood sample had the greatest agreement with the laboratory analyzer (mean bias, 1.9 mg/dL); all other PBGMs significantly underestimated blood glucose concentrations. A PBGM designed for use with human samples had the least agreement with the laboratory analyzer (mean bias, -34.0 mg/dL). Blood glucose concentration was not significantly different between central and peripheral venous blood samples for any analyzer used. CONCLUSIONS AND CLINICAL RELEVANCE: Significant underestimation of blood glucose concentrations as detected for 3 of the 4 PBGMs used in the study could have a substantial impact on clinical decision making. Verification of blood glucose concentrations in ferrets with a laboratory analyzer is highly recommended.

Petritz OA; Antinoff N; Chen S; Kass PH; Paul-Murphy JR

2013-02-01

58

The sphingosine-1-phosphate analog FTY720 reduces muscle ceramide content and improves glucose tolerance in high fat-fed male mice.  

UK PubMed Central (United Kingdom)

FTY720 is a sphingosine-1-phosphate analog that has been shown to inhibit ceramide synthesis in vitro. Because ceramide accumulation in muscle is associated with insulin resistance, we aimed to examine whether FTY720 would prevent muscle ceramide accumulation in high fat-fed mice and subsequently improve glucose homeostasis. Male C57Bl/6 mice were fed either a chow or high fat-diet (HFD) for 6 wk, after which they were treated with vehicle or FTY720 (5 mg/kg) daily for a further 6 wk. The ceramide content of muscle was examined and insulin action was assessed. Whereas the HFD increased muscle ceramide, this was prevented by FTY720 treatment. This was not associated with alterations in the expression of genes involved in sphingolipid metabolism. Interestingly, the effects of FTY720 on lipid metabolism were not limited to ceramide because FTY720 also prevented the HFD-induced increase in diacylglycerol and triacylglycerol in muscle. Furthermore, the increase in CD36 mRNA expression induced by fat feeding was prevented in muscle of FTY720-treated mice. This was associated with an attenuation of the HFD-induced increase in palmitate uptake and esterification. In addition, FTY720 improved glucose homeostasis as demonstrated by a reduction in plasma insulin, an improvement in whole-body glucose tolerance, an increase in insulin-stimulated glucose uptake, and Akt phosphorylation in muscle. In conclusion, FTY720 exerts beneficial effects on muscle lipid metabolism that prevent lipid accumulation and improve glucose tolerance in high fat-fed mice. Thus, FTY720 and other compounds that target sphingosine-1-phosphate signaling may have therapeutic potential in treating insulin resistance.

Bruce CR; Risis S; Babb JR; Yang C; Lee-Young RS; Henstridge DC; Febbraio MA

2013-01-01

59

Lack of correlation of glucose levels in filtered blood plasma to density and conductivity measurements.  

UK PubMed Central (United Kingdom)

The purpose of this research project was to determine whether the glucose level of a blood plasma sample from a diabetic patient could be predicted by measuring the density and conductivity of ultrafiltrate of plasma created by a 30,000 m.w. cutoff membrane. Conductivity of the plasma filtrate measures electrolyte concentration and should correct density measurements for changes in electrolytes and water concentration. In vitro studies were performed measuring conductivity and density of solutions of varying glucose and sodium chloride concentrations. Plasma from seven hospitalized patients with diabetes was filtered across a 30,000 m.w. cutoff membrane. The filtrate density and conductivity were measured and correlated to glucose levels. In vitro studies confirmed the ability to predict glucose from density and conductivity measurements, in varying concentrations of glucose and saline. In plasma filtrate, the conductivity and density measurements of ultrafiltrate allowed estimation of glucose in some patients with diabetes but not others. The correlation coefficient for the combined patient data was 0.45 which was significant but only explained 20% of the variability in the glucose levels. Individually, the correlation was significant in only two of the seven patients with correlation coefficients of 0.79 and 0.88. The reasons for lack of correlation are not clear, and cannot be explained by generation of idiogenic osmoles, effects of alcohol dehydrogenase, water intake, etc. This combination of physical methods for glucose measurement is not a feasible approach to measuring glucose in plasma filtrate.

Gordon DM; Ash SR

2009-05-01

60

Lack of correlation of glucose levels in filtered blood plasma to density and conductivity measurements.  

Science.gov (United States)

The purpose of this research project was to determine whether the glucose level of a blood plasma sample from a diabetic patient could be predicted by measuring the density and conductivity of ultrafiltrate of plasma created by a 30,000 m.w. cutoff membrane. Conductivity of the plasma filtrate measures electrolyte concentration and should correct density measurements for changes in electrolytes and water concentration. In vitro studies were performed measuring conductivity and density of solutions of varying glucose and sodium chloride concentrations. Plasma from seven hospitalized patients with diabetes was filtered across a 30,000 m.w. cutoff membrane. The filtrate density and conductivity were measured and correlated to glucose levels. In vitro studies confirmed the ability to predict glucose from density and conductivity measurements, in varying concentrations of glucose and saline. In plasma filtrate, the conductivity and density measurements of ultrafiltrate allowed estimation of glucose in some patients with diabetes but not others. The correlation coefficient for the combined patient data was 0.45 which was significant but only explained 20% of the variability in the glucose levels. Individually, the correlation was significant in only two of the seven patients with correlation coefficients of 0.79 and 0.88. The reasons for lack of correlation are not clear, and cannot be explained by generation of idiogenic osmoles, effects of alcohol dehydrogenase, water intake, etc. This combination of physical methods for glucose measurement is not a feasible approach to measuring glucose in plasma filtrate. PMID:19282748

Gordon, David M; Ash, Stephen R

 
 
 
 
61

Simultaneous measurement of glucose transport and utilization in the human brain  

Science.gov (United States)

Glucose is the primary fuel for brain function, and determining the kinetics of cerebral glucose transport and utilization is critical for quantifying cerebral energy metabolism. The kinetic parameters of cerebral glucose transport, KMt and Vmaxt, in humans have so far been obtained by measuring steady-state brain glucose levels by proton (1H) NMR as a function of plasma glucose levels and fitting steady-state models to these data. Extraction of the kinetic parameters for cerebral glucose transport necessitated assuming a constant cerebral metabolic rate of glucose (CMRglc) obtained from other tracer studies, such as 13C NMR. Here we present new methodology to simultaneously obtain kinetic parameters for glucose transport and utilization in the human brain by fitting both dynamic and steady-state 1H NMR data with a reversible, non-steady-state Michaelis-Menten model. Dynamic data were obtained by measuring brain and plasma glucose time courses during glucose infusions to raise and maintain plasma concentration at ?17 mmol/l for ?2 h in five healthy volunteers. Steady-state brain vs. plasma glucose concentrations were taken from literature and the steady-state portions of data from the five volunteers. In addition to providing simultaneous measurements of glucose transport and utilization and obviating assumptions for constant CMRglc, this methodology does not necessitate infusions of expensive or radioactive tracers. Using this new methodology, we found that the maximum transport capacity for glucose through the blood-brain barrier was nearly twofold higher than maximum cerebral glucose utilization. The glucose transport and utilization parameters were consistent with previously published values for human brain.

Shestov, Alexander A.; Emir, Uzay E.; Kumar, Anjali; Henry, Pierre-Gilles; Seaquist, Elizabeth R.

2011-01-01

62

OVERNIGHT CLOSED-LOOP INSULIN DELIVERY WITH MODEL PREDICTIVE CONTROL AND GLUCOSE MEASUREMENT ERROR MODEL  

UK PubMed Central (United Kingdom)

A closed-loop system for insulin infusion overnight uses a model predictive control algorithm ("MPC"). Used with the MPC is a glucose measurement error model which was derived from actual glucose sensor error data. That sensor error data included both a sensor artifacts component, including dropouts, and a persistent error component, including calibration error, all of which was obtained experimentally from living subjects. The MPC algorithm advised on insulin infusion every fifteen minutes. Sensor glucose input to the MPC was obtained by combining model-calculated, noise-free interstitial glucose with experimentally-derived transient and persistent sensor artifacts associated with the FreeStyle Navigator TM Continuous Glucose Monitor System ("FSN"). The incidence of severe and significant hypoglycemia reduced 2300- and 200-fold, respectively, during simulated overnight closed-loop control with the MPC algorithm using the glucose measurement error model suggesting that the continuous glucose monitoring technologies facilitate safe closed-loop insulin delivery.

WILINSKA MALGORZATA E; BUDIMAN ERWIN S; HAYTER GARY A; TAUB MARC B; HOVORKA ROMAN

63

Measuring Glucose Concentrations: Daily Practice, Current and Future Developments  

Digital Repository Infrastructure Vision for European Research (DRIVER)

Self-monitoring of blood glucose (SMBG) by means of modern glucose meters is of relevance for all patients with diabetes. It not only provides important information about the effect of therapeutic interventions on metabolic control, but about the effect of exercise and meals as well. Therefore, it i...

Heinemann, Lutz

64

Glycolysis-induced discordance between glucose metabolic rates measured with radiolabeled fluorodeoxyglucose and glucose  

Energy Technology Data Exchange (ETDEWEB)

We have developed an autoradiographic method for estimating the oxidative and glycolytic components of local CMRglc (LCMRglc), using sequentially administered ({sup 18}F)fluorodeoxyglucose (FDG) and ({sup 14}C)-6-glucose (GLC). FDG-6-phosphate accumulation is proportional to the rate of glucose phosphorylation, which occurs before the divergence of glycolytic (GMg) and oxidative (GMo) glucose metabolism and is therefore related to total cerebral glucose metabolism GMt: GMg + GMo = GMt. With oxidative metabolism, the {sup 14}C label of GLC is temporarily retained in Krebs cycle-related substrate pools. We hypothesize that with glycolytic metabolism, however, a significant fraction of the {sup 14}C label is lost from the brain via lactate production and efflux from the brain. Thus, cerebral GLC metabolite concentration may be more closely related to GMo than to GMt. If true, the glycolytic metabolic rate will be related to the difference between FDG- and GLC-derived LCMRglc. Thus far, we have studied normal awake rats, rats with limbic activation induced by kainic acid (KA), and rats visually stimulated with 16-Hz flashes. In KA-treated rats, significant discordance between FDG and GLC accumulation, which we attribute to glycolysis, occurred only in activated limbic structures. In visually stimulated rats, significant discordance occurred only in the optic tectum.

Ackermann, R.F.; Lear, J.L. (UCLA School of Medicine (USA))

1989-12-01

65

Glycolysis-induced discordance between glucose metabolic rates measured with radiolabeled fluorodeoxyglucose and glucose  

International Nuclear Information System (INIS)

[en] We have developed an autoradiographic method for estimating the oxidative and glycolytic components of local CMRglc (LCMRglc), using sequentially administered [18F]fluorodeoxyglucose (FDG) and [14C]-6-glucose (GLC). FDG-6-phosphate accumulation is proportional to the rate of glucose phosphorylation, which occurs before the divergence of glycolytic (GMg) and oxidative (GMo) glucose metabolism and is therefore related to total cerebral glucose metabolism GMt: GMg + GMo = GMt. With oxidative metabolism, the 14C label of GLC is temporarily retained in Krebs cycle-related substrate pools. We hypothesize that with glycolytic metabolism, however, a significant fraction of the 14C label is lost from the brain via lactate production and efflux from the brain. Thus, cerebral GLC metabolite concentration may be more closely related to GMo than to GMt. If true, the glycolytic metabolic rate will be related to the difference between FDG- and GLC-derived LCMRglc. Thus far, we have studied normal awake rats, rats with limbic activation induced by kainic acid (KA), and rats visually stimulated with 16-Hz flashes. In KA-treated rats, significant discordance between FDG and GLC accumulation, which we attribute to glycolysis, occurred only in activated limbic structures. In visually stimulated rats, significant discordance occurred only in the optic tectum

1989-01-01

66

Intravascular microdialysis as a method for measuring glucose and lactate during and after cardiac surgery.  

UK PubMed Central (United Kingdom)

BACKGROUND: The aim was to evaluate intravascular microdialysis as a method for measuring blood glucose and lactate in a clinical setting during and after cardiac surgery. METHODS: Ten patients undergoing cardiac surgery were included. A microdialysis catheter was percutaneously placed in the superior vena cava or right atrium. Glucose and lactate values measured by the microdialysis technique were analyzed and compared with reference methods, i.e., arterial and venous blood gas values, once every hour up to 24 hours postoperatively. Laboratory plasma glucose was additionally analyzed every 4 hours for reference value. RESULTS: Mean absolute differences were low between microdialysis and reference methods for both glucose and lactate values. All microdialysis glucose values were in the clinically acceptable zone of error grid analysis when compared with plasma glucose values. Accuracy of glucose values was 92% according to International Organization for Standardization criteria. CONCLUSIONS: Intravascular microdialysis is a novel and promising technique for real-time and accurate measurement of glucose and lactate during and after open heart surgery. Development of sensor technology may allow for continuous measurement of blood glucose and lactate using intravascular microdialysis.

Möller F; Liska J; Eidhagen F; Franco-Cereceda A

2011-09-01

67

Measurement of glucose and lipid metabolism in avian liver explants.  

Science.gov (United States)

1. A mechanical tissue chopper was used to obtain 35-75 mg explants from 21- to 28-day-old chick liver to determine assay conditions (substrates, buffers, time), regulators (metals and hormones) and points of endogenous regulation of de novo lipogenesis (ATPase, reductive potential and protein phosphorylation). High- and low-bicarbonate-based buffers (Earl's balance salts, EBSS and Hanks' balanced salts, HBSS; respectively) were used in conjunction with sources and types of bovine serum albumin (BSA), divalent cations (Mg2+ or Ca2+), substrate (glucose or acetate) and hormones (insulin and catecholamines). 2. Neither EBSS nor HBSS changed in vitro lipogenesis, CO2 or glucose production when 20 mM HEPES was added to these salts. 3. Neither the presence nor the source of BSA (Sigma or Armour) affected metabolism. In contrast, reducing the vessel reaction surface area (5.1 vs 10.5 cm2) decreased metabolic rates. 4. Acetate was more readily utilized than glucose as an in vitro fatty acid precursor. Use of glucose was complicated by production of glucose from endogenous precursors and by label recycling. Divalent cations (Mg2+ or Ca2+) had little affect upon lipogenesis. 5. Chicken insulin (50 ng/ml) did not affect lipogenesis; however, incorporation of acetate into fatty acids was decreased by dibutyryl cyclic AMP. A catecholamine-induced decrease in vitro lipogenesis indicates that major points of regulation are under control of phosphorylation-dephosphorylation steps. PMID:3427927

Rosebrough, R W; Steele, N C

1987-01-01

68

Measurement of glucose and lipid metabolism in avian liver explants.  

UK PubMed Central (United Kingdom)

1. A mechanical tissue chopper was used to obtain 35-75 mg explants from 21- to 28-day-old chick liver to determine assay conditions (substrates, buffers, time), regulators (metals and hormones) and points of endogenous regulation of de novo lipogenesis (ATPase, reductive potential and protein phosphorylation). High- and low-bicarbonate-based buffers (Earl's balance salts, EBSS and Hanks' balanced salts, HBSS; respectively) were used in conjunction with sources and types of bovine serum albumin (BSA), divalent cations (Mg2+ or Ca2+), substrate (glucose or acetate) and hormones (insulin and catecholamines). 2. Neither EBSS nor HBSS changed in vitro lipogenesis, CO2 or glucose production when 20 mM HEPES was added to these salts. 3. Neither the presence nor the source of BSA (Sigma or Armour) affected metabolism. In contrast, reducing the vessel reaction surface area (5.1 vs 10.5 cm2) decreased metabolic rates. 4. Acetate was more readily utilized than glucose as an in vitro fatty acid precursor. Use of glucose was complicated by production of glucose from endogenous precursors and by label recycling. Divalent cations (Mg2+ or Ca2+) had little affect upon lipogenesis. 5. Chicken insulin (50 ng/ml) did not affect lipogenesis; however, incorporation of acetate into fatty acids was decreased by dibutyryl cyclic AMP. A catecholamine-induced decrease in vitro lipogenesis indicates that major points of regulation are under control of phosphorylation-dephosphorylation steps.

Rosebrough RW; Steele NC

1987-01-01

69

Immunocytochemistry of GLUT2, uptake of fluorescent desnitroso-streptozotocin analogs and phosphorylation of D-glucose in INS-1E cells.  

Science.gov (United States)

The non-invasive imaging of GLUT2-expressing cells remains a challenge. As streptozotocin, and similarly alloxan, may be transported into cells by GLUT2, the major aim of the present study was to assess the possible use of fluorescent desnitroso-streptozotocin analogs for in vitro labeling of GLUT2-expressing cells. INS-1E cells, human embryonic kidney (HEK) cells, rat isolated pancreatic islets, rat hepatic cells, rat exocrine pancreatic cells and tumoral insulin-producing BRIN-BD11 cells were incubated in the presence of two distinct fluorescent desnitroso-streptozotocin analogs, probes A and B. The immunocytochemistry of GLUT2 in INS-1E cells and the phosphorylation of D-glucose by INS-1E cell homogenates were also examined. The uptake of probes A and B (12.0 µM) by INS-1E cells yielded apparent intracellular concentrations approximately one order of magnitude higher than the extracellular concentration. The two probes differed from one another by the absolute values for their respective uptake and time course, but not so by the pattern of their concentration dependency. Comparable results were recorded in HEK cells, rat isolated pancreatic islets and hepatocytes. Vastly different findings were recorded, however, in rat exocrine pancreatic cells, which do not express GLUT2. Moreover, an unusual concentration dependency for the uptake of each probe was observed in tumoral BRIN-BD11 cells. It is proposed that suitable fluorescent desnitroso-streptozotocin analogs may be used to label GLUT2-expressing cells. PMID:23807415

Virreira, Myrna; Popescu, Iuliana; Gillet, Celine; Zhang, Ying; Leshch, Yevgeniy; Thimm, Julian; Thiem, Joachim; Malaisse, Willy J; Sener, Abdullah

2013-06-27

70

Maximum-likelihood reconstruction of photon returns from simultaneous analog and photon-counting lidar measurements  

CERN Document Server

We present a novel method for combining the analog and photon-counting measurements of lidar transient recorders into reconstructed photon returns. The method takes into account the statistical properties of the two measurement modes and estimates the most likely number of arriving photons and the most likely values of acquisition parameters describing the two measurement modes. It extends and improves the standard combining ("gluing") methods and does not rely on any ad hoc definitions of the overlap region nor on any ackground subtraction methods.

Veberic, Darko

2011-01-01

71

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

Directory of Open Access Journals (Sweden)

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.

Prof..Mrs.A.A.Shinde; Dr.R.K.Prasad

2011-01-01

72

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)

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

Gama MP; Cruzeta CF; Ossowski AC; Bay MR; Michaelis MM; Camacho SL

2012-01-01

73

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

Energy Technology Data Exchange (ETDEWEB)

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.

Hinkson, J.A. [Lawrence Berkeley Lab., CA (US); Unser, K.B. [Consultant, Genis-Pouilly (France)

1995-05-01

74

[Are blood glucose measurements made with portable glucometers reliable?].  

UK PubMed Central (United Kingdom)

Examinations performed beside the bed of patients ("Point-of-care testing, POCT") provide immediate results and are simple to perform. The most common of these tests is the self control of blood glucose levels in diabetic patients. The use of these devices at the hospital level, introduces a new set of requirements to health institutions, which should monitor all aspects of the process, including training of final users, proper quality control, development of written procedures for use and even participation in surveys of external quality control, avoiding the generation of errors and guaranteeing patient safety.

Guzmán D AM; Quiroga G T

2009-09-01

75

FASTBUS recording System for measurement of time intervals and analog signals for the Sphere spectrometer  

International Nuclear Information System (INIS)

[en] A FASTBUS recording system used to measure time intervals and fast analog signal at the SPHERE spectrometer is described. The system is based on a 16-channel 8-bit ADC FASTBUS module, a 16-channel 16-bit TDC FASTBUS module and a FIORI interface module connected to CAMAC registers realized data transfer between a FASTBUS segment and a CAMAC dataway. The operation of the system is controlled by an Electronika-60 microcomputer connected to a CAMAC crate controller. The software used in the system provides communication between the FASTBUS segment and the computer, module testing, data acquisition and processing, and result presentation

1988-01-01

76

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

International Nuclear Information System (INIS)

[en] 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 striatal function in various movement disorders. (author)

1992-01-01

77

Non-invasive polarimetric measurement of glucose concentration in the anterior chamber of the eye.  

UK PubMed Central (United Kingdom)

BACKGROUND: Diabetes mellitus is one of the most common diseases in industrialized countries as well as in emerging economies such as India or China. One of the key technologies for diabetes therapy is semi-continuous monitoring of the glucose level of diabetics. METHODS: Compared with skin-perforating techniques, optical measurement techniques promising good results bear the potential for high patient compliance with more frequent measurements. Due to its excellent optical properties, the anterior chamber and the aqueous humor (AH) contained therein offer promise for non-invasive in vivo glucose measurements. However, a number of strongly limiting factors, such as the precise optical properties of the eye, laser safety regulations and subconscious eye movements during the measurement period have to be considered for in vivo applications. RESULTS: This article presents a high-resolution polarimetric measurement system that utilizes the optical rotatory dispersion (optical activity) of the glucose molecule for measurements of the glucose concentration in AH. CONCLUSION: Based on this example of a suitable optical measurement system, the special limitations and conditions that have to be considered for in vivo glucose measurement at the human eye are presented and analyzed. This includes the optical properties of the cornea and the anterior chamber, the impact of typical eye movements during a measurement and laser safety regulations.

Rawer R; Stork W; Kreiner CF

2004-12-01

78

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

UK PubMed Central (United Kingdom)

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.

Coté GL; Fox MD; Northrop RB

1992-07-01

79

Shape information from glucose curves: functional data analysis compared with traditional summary measures.  

UK PubMed Central (United Kingdom)

ABSTRACT: BACKGROUND: Plasma glucose levels are important measures in medical care and research, and are often obtained from oral glucose tolerance tests (OGTT) with repeated measurements over 2-3? hours. It is common practice to use simple summary measures of OGTT curves. However, different OGTT curves can yield similar summary measures, and information of physiological or clinical interest may be lost. Our mean aim was to extract information inherent in the shape of OGTT glucose curves, compare it with the information from simple summary measures, and explore the clinical usefulness of such information. METHODS: OGTTs with five glucose measurements over two hours were recorded for 974 healthy pregnant women in their first trimester. For each woman, the five measurements were transformed into smooth OGTT glucose curves by functional data analysis (FDA), a collection of statistical methods developed specifically to analyse curve data. The essential modes of temporal variation between OGTT glucose curves were extracted by functional principal component analysis. The resultant functional principal component (FPC) scores were compared with commonly used simple summary measures: fasting and two-hour (2-h) values, area under the curve (AUC) and simple shape index (2-h minus 90-min values, or 90-min minus 60-min values). Clinical usefulness of FDA was explored by regression analyses of glucose tolerance later in pregnancy. RESULTS: Over 99% of the variation between individually fitted curves was expressed in the first three FPCs, interpreted physiologically as "general level" (FPC1), "time to peak" (FPC2) and "oscillations" (FPC3). FPC1 scores correlated strongly with AUC (r=0.999), but less with the other simple summary measures (-0.42?r?0.79). FPC2 scores gave shape information not captured by simple summary measures (-0.12?r?0.40). FPC2 scores, but not FPC1 nor the simple summary measures, discriminated between women who did and did not develop gestational diabetes later in pregnancy. CONCLUSIONS: FDA of OGTT glucose curves in early pregnancy extracted shape information that was not identified by commonly used simple summary measures. This information discriminated between women with and without gestational diabetes later in pregnancy.

Frøslie KF; Røislien J; Qvigstad E; Godang K; Bollerslev J; Voldner N; Henriksen T; Veierød MB

2013-01-01

80

[Effect of borate polymer layers on measurement of glucose concentration by SPR].  

Science.gov (United States)

A new borate polymer PAA-ran-PAAPBA that can specifically adsorb glucose was introduced in the glucose measurement based on surface plasmon resonance, and the high-precision specific detection of glucose concentration was realized. Six layers and twelve layers of borate polymer were respectively bound onto the SPR sensors through the layer-by-layer self-assembly binding method, and the effect of different layers of borate polymer on the glucose surface plasmon resonance measurement was studied. The experiment was conducted in the concentration range of 1-10 mg x dL(-1) (interval delta = 1 mg x dL(-1)), 10-100 mg x dL(-1) (interval delta = 10 mg x dL(-1)), and 100-1 000 mg x dL(-1) (interval delta = 100 mg x dL(-1)), experiment data was fitted by quadric curve and the fitting degree of refractive index difference deltaRU and glucose concentration was obtained. Results showed that the 12-layer-polymer sensor was better than the 6-layer-polymer sensor in the first two smaller ranges, and the measuring result was not significantly affected by layers in the third range, indicating that for the small concentrations increasing polymer layer can dramatically improve the measurement. PMID:23586243

Li, Da-Chao; Yang, Jia; Wu, Peng; Zhu, Rui; Wang, Bo; Lin, Yuan; Xu, Ke-Xin

2013-01-01

 
 
 
 
81

[Effect of borate polymer layers on measurement of glucose concentration by SPR].  

UK PubMed Central (United Kingdom)

A new borate polymer PAA-ran-PAAPBA that can specifically adsorb glucose was introduced in the glucose measurement based on surface plasmon resonance, and the high-precision specific detection of glucose concentration was realized. Six layers and twelve layers of borate polymer were respectively bound onto the SPR sensors through the layer-by-layer self-assembly binding method, and the effect of different layers of borate polymer on the glucose surface plasmon resonance measurement was studied. The experiment was conducted in the concentration range of 1-10 mg x dL(-1) (interval delta = 1 mg x dL(-1)), 10-100 mg x dL(-1) (interval delta = 10 mg x dL(-1)), and 100-1 000 mg x dL(-1) (interval delta = 100 mg x dL(-1)), experiment data was fitted by quadric curve and the fitting degree of refractive index difference deltaRU and glucose concentration was obtained. Results showed that the 12-layer-polymer sensor was better than the 6-layer-polymer sensor in the first two smaller ranges, and the measuring result was not significantly affected by layers in the third range, indicating that for the small concentrations increasing polymer layer can dramatically improve the measurement.

Li DC; Yang J; Wu P; Zhu R; Wang B; Lin Y; Xu KX

2013-01-01

82

Labelled antibody assays for measuring free triiodothyronine: evaluation and comparison with a labelled analog method  

International Nuclear Information System (INIS)

We evaluated analytically and clinically two new one-step labelled antibody assays for measuring free triiodothyronine (FT3): the first, radiolabelled with 125 I, Amerlex-MAB (MAB) from Kodak diagnostic, and the second, labelled with peroxidase, Enzymum-test FT3 (BM) from Boehringer Mannheim adapted for the Boehringer ES 600 analyzer. The clinical results were compared with those obtained with a radiolabelled analog tracer kit, Amerlex-M (M) from Kodak diagnostic. The latter kit is known to give low FT3 results in sera with low albumin concentrations. Analytical performances of the automated method (BM) were better than those obtained with the manual method (MAB): intra-assay reproducibility (CV

1993-01-01

83

H-2g, a glucose analog of blood group H antigen, mediates mononuclear cell recruitment via Src and phosphatidylinositol 3-kinase pathways.  

UK PubMed Central (United Kingdom)

OBJECTIVE: Monocyte recruitment by proinflammatory cytokines is a hallmark of rheumatoid arthritis (RA). Lewis(y-6) and H (Le(y)/H) are blood group antigens up-regulated on RA synovial endothelium. We have previously shown that both soluble Le(y)/H and a glucose analog of H, H-2g, are angiogenic and mediateleukocyte-endothelial adhesion via induction of intercellular adhesion molecule 1. We hypothesized that soluble Le(y)/H plays an important role in monocyte recruitment in RA. METHODS: We examined the role of H-2g in monocyte chemotaxis in vitro. We used an RA synovial tissue (ST)-SCID mouse chimera model to evaluate the role of H-2g in monocyte recruitment in vivo. We used Western blots to examine signaling molecules activated by H-2g in monocytes. RESULTS: H-2g induced human monocyte migration in vitro, which was mediated by Src and phosphatidylinositol 3-kinase (PI 3-kinase), since inhibitors and antisense oligodeoxynucleotides (ODNs) of Src and PI 3-kinase significantly decreased H-2g-induced monocyte migration (P < 0.05). H-2g significantly increased mononuclear cell (MNC) homing in vivo into an RA ST-SCID mouse chimera (P < 0.05). Transfection of MNCs with Src antisense ODNs blocked H-2g-induced MNC recruitment into the RA ST-SCID mouse chimera. Additionally, H-2g induced marked phosphorylation of protein kinase CalphaI/betaII (PKCalphaI/betaII), Src, IkappaBalpha, and Akt in monocytes. Src, Akt, and NF-kappaB were shown to be downstream targets of PKCalphaI/betaII, since an inhibitor of PKCalphaI/betaII reduced H-2g-mediated phosphorylation of Src, Akt, and NF-kappaB in monocytes. CONCLUSION: These data suggest that H-2g may be a novel mediator of monocyte recruitment in chronic inflammatory diseases like RA.

Amin MA; Ruth JH; Haas CS; Pakozdi A; Mansfield PJ; Haghshenas J; Koch AE

2008-03-01

84

Feasibility of fully automated closed-loop glucose control utilizing continuous subcutaneous glucose measurements in critical illness: a randomised controlled trial.  

UK PubMed Central (United Kingdom)

INTRODUCTION: Closed-loop (CL) systems modulate insulin delivery according to glucose levels without nurse input. In a prospective randomized controlled trial, we evaluated the feasibility of an automated closed-loop approach based on subcutaneous glucose measurements in comparison to a local sliding scale insulin therapy protocol. METHODS: 24 critically ill adults (predominantly trauma and neuroscience patients) with hyperglycaemia (glucose [greater than or equal to] 10 mmol/l) or already receiving insulin therapy were randomized to receive either fully automated closed-loop therapy (model predictive control algorithm directing insulin and 20% dextrose infusion based on FreeStyle Navigator continuous subcutaneous glucose values, N = 12) or a local protocol (N = 12) with intravenous sliding scale insulin, over 48 hours. The primary endpoint was percentage time when arterial blood glucose was between 6.0 and 8.0 mmol/l. RESULTS: Time when glucose was in target was significantly increased during closed-loop therapy (54.3% [44.1-72.8] vs. 18.5% [0.1-39.9], P=0.001; median [interquartile range]) and so was time in wider targets 5.6-10.0 mmol/l and 4.0-10.0 mmol/l (P[less than or equal to]0.002) reflecting a reduced glucose exposure above 8 and 10 mmol/l (P[less than or equal to]0.002). Mean glucose was significantly lower during CL (7.8 [7.4-8.2] vs. 9.1 [8.3-13.0] mmol/l, P=0.001) without hypoglycaemia (<4 mmol/l) during either therapy. CONCLUSIONS: Fully automated closed loop control based on subcutaneous glucose measurements is feasible and may provide efficacious and hypoglycaemia-free glucose control in critically ill adults. Trial Registration: ClinicalTrials.gov Identifier - NCT01440842.

Leelarathna L; English SW; Thabit H; Caldwell K; Allen JM; Kumareswaran K; Wilinska ME; Nodale M; Mangat J; Evans ML; Burnstein R; Hovorka R

2013-07-01

85

Prevalence and cost of possibly unnecessary venous blood glucose measurements in primary care.  

UK PubMed Central (United Kingdom)

The American Diabetes Association issues annually its recommendations for diabetes mellitus screening. Although there is a high proportion of people with undiagnosed diabetes in the general population, it is suspected that many of these screening tests could be needless. An analysis was made of the number of venous blood glucose measurements that did not meet the American Diabetes Association requirements performed in 150 people seen in primary care. On average, an unnecessary venous blood glucose measurement is performed every 15 months. The number is significantly higher in people over 45 years of age, and also in women as compared to men (although with a p value slighty higher than 0.05).

Díez Pérez C; Rodríguez Ferro R; Penín Álvarez M

2013-06-01

86

Comparison between (1-11C)-D-glucose, (U-11C)-D-glucose, and (18F)2-fluoro-2-deoxy-D-glucose as tracers for PET measurement of cerebral glucose utilization  

International Nuclear Information System (INIS)

[en] (1-11C)-D-glucose(1-G) is evaluated as a tracer for cerebral glucose utilization and compared to uniformly labelled glucose, (U-11C)-D-glucose, to (18F)2-fluoro-2-deoxy-D-glucose (FDG), and to results obtained by the Fick principle. (author). 14 refs.; 3 figs.; 1 tab

1989-01-01

87

Calibration of glucose oxidase-based test strips for capillary blood measurement with oxygen saturated venous blood samples.  

UK PubMed Central (United Kingdom)

BACKGROUND: Glucose oxidase biosensors are used in self-monitoring blood glucose concentrations. The capillary blood glucose quantitation requires a calibration curve. Due to the limitation in obtaining calibration curve from capillary blood, an alternate approach by using venous blood for neonatal measurement was investigated. METHODS: A signal correlation between oxygen saturated venous blood and capillary blood was derived. The hematocrit effect was studied for different glucose concentrations. The calibrated glucose strips were validated by neonatal intensive care unit (NICU) samples. RESULTS: A simple equation, finger blood signal=1.39?(oxygen saturated venous blood signal)-31.2 was derived. The rate of change in glucose concentration due to hematocrit effect was low in lower glucose concentration samples. The BeneCheck Glucose Strips were compared with Beckman Coulter analyzer by using 52 NICU samples. More than 95% of test results were within the variation of ±10 mg/dl of bias and ±15% of bias% when glucose concentration is <75 mg/dl and ?75 mg/dl respectively. CONCLUSIONS: The BeneCheck Glucose Strips can be accurately calibrated with venous blood. The hematocrit effect can also be predicted. Based on this study, BeneCheck Blood Glucose Monitoring System can be suitable for neonatal glucose measurement.

Cheng WJ; Lin CW; Wu TG; Su CS; Hsieh MS

2013-01-01

88

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

89

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

International Nuclear Information System (INIS)

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.

2013-06-10

90

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

Science.gov (United States)

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.

Horst, Sarah; Tolbert, M. A.

2013-10-01

91

Continuous on-line glucose measurement by microdialysis in a central vein. A pilot study.  

UK PubMed Central (United Kingdom)

INTRODUCTION: Tight glucose control in the ICU has been proven difficult with an increased risk for hypoglycaemic episodes. Also the variability of glucose may have an impact on morbidity. An accurate and feasible on-line/continuous measurement is therefore desired. In this study a central vein catheter with a microdialysis membrane in combination with an on-line analyzer for continuous monitoring of circulating glucose and lactate by the central route was tested. METHODS: 10 patients scheduled for major upper abdominal surgery were included in this observational prospective study at a university hospital. The patients received an extra central venous catheter with a microdialysis membrane placed in the right jugular vein. Continuous microdialysis measurement proceeded for 20 hours and on-line values were recorded every minute. As reference arterial plasma glucose and blood lactate samples were collected every hour. RESULTS: Mean microdialysis-glucose during measurements was 9.8+/-2.4mmol/l. No statistical difference in the readings was seen using single calibration compared to eighth hour calibration (p=0.09; t-test). There was a close agreement between the continuous reading and the reference plasma glucose values with an absolute difference of 0.6+0.8mmol, or 6.8+9.3% and measurements showed high correlation to plasma readings (r=0.92). The limit of agreement was 23.0% (1.94 mmol/l) compared to arterial plasma values with a line of equality close to zero. However, in a Clarke-Error Grid 93.3% of the values are in the A-area , and the remaining part in the B-area. Mean microdialysis-lactate was 1.3+/-1.1mmol/l. The measurements showed high correlation to the blood readings (r=0.93). CONCLUSION: Continuous on-line microdialysis glucose measurement in a central vein is a potential useful technique for continuous glucose monitoring in critically ill patients, but more improvements and testing is needed.

Blixt C; Rooyackers O; Isaksson B; Wernerman J

2013-05-01

92

Evaluating the blood glucose measured via glucometry in diagnosis of hypoglycemia in neonates  

Directory of Open Access Journals (Sweden)

Full Text Available Introduction: Hypoglycemia is one of the most prevalent problems seen in neonates and can lead toirreversible brain damage if not to be diagnosed in time. Today, the blood glucose is mostly checked bylaboratory methods that have a significant delay and can result in many adverse effects such as vesselrupture. The goal of this study was to evaluate the value of the glucometry device in diagnosis ofhypoglycemia in neonates.Materials and Methods: This study has been conducted over 156 hospitalized neonates in Amir almomenin Hospital, Semnan, Iran. The blood glucose in all cases has been simultaneously measured by bothlaboratory methods (glucose oxidase as the golden standard) and glucometer. These measurements alongwith the relevant data for neonatal risk factors were recorded in the checklist. The blood glucosemeasurements of less than or equal 35 mg/dL in first two hours after birth, less than or equal 40mg/dL in 3to 24 hours after birth, less than or equal 45 mg/dL in more than 24 hours after birth are considered ashypoglycemic.Results: 58 neonates (37.2%) were hypoglycemic.The measurement of blood glucose levels viaglucometer for hypoglycemia detection had a high precision (Area under curve = 0.941, Standard error=0.018, P= 0.0001). The optimum cut-off point yielded to equivalent of 51mg/dL. So that for fasting bloodglucose of less than or equal 51mg/dL, sensitivity, specificity, positive, and negative predictive values were,respectively, 94.7%, 81.6%, 75.3%, and 96.4%.Conclusion: Findings show that, blood glucose levels measured by glucometry have goodaccuracy for diagnosis of hypoglycemia in newborns. Thus, it is recommended that in case ofscreening and frequent need of monitoring neonatal blood glucose, this device be used as asuitable replacement of laboratory methods

Shamsollah Nooripoor; Raheb Ghorbani; Farhad Azizzadeh; Navid Danai; Mohammad Sadegh Yazdiha

2012-01-01

93

METHOD OF OVERNIGHT CLOSED-LOOP INSULIN DELIVERY WITH MODEL PREDICTIVE CONTROL AND GLUCOSE MEASUREMENT ERROR MODEL  

UK PubMed Central (United Kingdom)

A closed-loop method for insulin infusion overnight uses a model predictive control algorithm ("MPC"). Used with the MPC is a glucose measurement error model which was derived from actual glucose sensor error data. That sensor error data included both a sensor artifacts component, including dropouts, and a persistent error component, including calibration error, all of which was obtained experimentally from living subjects. The MPC algorithm advised on insulin infusion every fifteen minutes. Sensor glucose input to the MPC was obtained by combining model-calculated, noise-free interstitial glucose with experimentally-derived transient and persistent sensor artifacts associated with the FreeStyle Navigator TM Continuous Glucose Monitor System ("FSN"). The incidence of severe and significant hypoglycemia reduced 2300- and 200-fold, respectively, during simulated overnight closed-loop control with the MPC algorithm using the glucose measurement error model suggesting that the continuous glucose monitoring technologies facilitate safe closed-loop insulin delivery.

WILINSKA MALGORZATA E; BUDIMAN ERWIN S; HAYTER GARY A; TAUB MARC B; HOVORKA ROMAN

94

A new principle for measurement of cobalamin and corrinoids, used for studies of cobalamin analogs on serum haptocorrin.  

UK PubMed Central (United Kingdom)

BACKGROUND: Transcobalamin (TC) and haptocorrin (HC) are serum corrinoid-binding proteins. We developed new methods for measurement of the corrinoids bound to HC and TC. METHODS: TC (n = 10) or HC (n = 138) was immunoprecipitated, and corrinoids were released by enzymatic degradation [subtilisin Carlsberg (EC 3.4.21.62)] of the binding proteins. Binding of the released corrinoids to added unsaturated TC (apoTC) or HC (apoHC) created holoTC (as measure of cobalamins) and holoHC (as measure of corrinoids). holoTC and holoHC were measured by use of ELISA. The amounts of analogs were calculated as the difference between corrinoids and cobalamins. Corrinoids extracted from HC were separated with HPLC after addition of potassium cyanide (n = 3). RESULTS: The corrinoid- and cobalamin-specific assays had a positive linear relation between analyte concentration and assay signal, detection limits of 8 and 4 pmol/L, and imprecision values (CV) of analogs were bound to serum TC, whereas the mean (95% reference range) for analogs present on HC was 245 (100-380) pmol/L. On HPLC a substantial amount of the analogs showed elution patterns similar to those of dicyanocobinamide. CONCLUSIONS: Our methods for measurement of unmodified corrinoids in serum demonstrate that HC carries cobalamin analogs not recognized by TC, and that on HPLC a substantial part of these analogs elute similarly to cobinamide.

Hardlei TF; Nexo E

2009-05-01

95

Intraoperative accuracy of a point-of-care glucose meter compared with simultaneous central laboratory measurements.  

UK PubMed Central (United Kingdom)

BACKGROUND: Concerns have been raised about the use of point-of-care (POC) glucose meters in the hospital setting. Accuracy has been questioned especially in critically ill patients. Although commonly used in intensive care units and operating rooms, POC meters were not approved by the Food and Drug Administration for such use. Data on POC glucose meter performance during anesthesia are lacking. We evaluated accuracy of a POC meter in the intraoperative setting. METHODS: We retrospectively reviewed 4,333 intraoperative records in which at least one intraoperative glucose was measured using electronic medical records at a large academic hospital. We evaluated the accuracy of a POC glucose meter (ACCU-CHEK® Inform, Roche Pharmaceuticals) based on the 176 simultaneous central laboratory (CL) blood glucose (BG) measurements that were found (i.e., documented collection times within 5 minutes). Point-of-care and central lab BG differences were analyzed by Bland-Altman and revised error grid analysis (rEGA). RESULTS: Mean POC BG was 163.4 ± 64.7 mg/dl [minimum (min) 48 mg/dl, maximum (max) 537 mg/dl] and mean CL BG was 162.6 ± 65.1 mg/dl (min 44 mg/dl, max 502 mg/dl). Mean absolute difference between POC and CL BG was 24.3 mg/dl. Mean absolute relative difference was 16.5% with standard deviation 26.4%. Point-of-care measurements showed a bias of 0.8 relative to the corresponding CL value, with a precision of 39.0 mg/dl. Forty (23%) POC BG values fell outside the Clinical and Laboratory Standards Institute guideline and 3.4% POC measurements fell in zones C and D of the rEGA plot. CONCLUSIONS: The tested POC glucose meter performed poorly compared to a CL analyzer intraoperatively. Perioperative clinicians should be aware of limitations of specific POC glucose meters, and routine use of POC glucose meters as sole measurement devices in the intraoperative period should be carefully considered.

Mraovic B; Schwenk ES; Epstein RH

2012-05-01

96

Analog earthquakes  

Energy Technology Data Exchange (ETDEWEB)

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.

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

1995-09-01

97

Quantity and quality of nocturnal sleep affect morning glucose measurement in acutely burned children.  

UK PubMed Central (United Kingdom)

Hyperglycemia after severe burn injury has long been recognized, whereas sleep deprivation after burns is a more recent finding. The postburn metabolic effects of poor sleep are not clear despite reports in other populations demonstrating the association between sleep insufficiency and deleterious endocrine consequences. The aim of this study was to determine whether a relationship between sleep and glucose dynamics exists in acutely burned children. Two overnight polysomnography runs (2200 to 0600) per subject were conducted in 40 patients with a mean (± SEM) age of 9.4?±?0.7 years, 50.1?±?2.9% TBSA burn, and 43.2?±?3.6% full-thickness injury. Serum glucose was drawn in the morning (0600) immediately after the sleep test. Insulin requirements during the 24-hour period preceding the 0600 glucose measurement were recorded. Generalized linear models were used by the authors to evaluate percent time in each stage of sleep, percent wake time, total sleep time, sleep efficiency, and morning serum glucose, accounting for insulin use. Increased time awake (P = .04, linear; P = .02, quadratic) and reduced time spent in stage 1 sleep (P = .03, linear) were associated with higher glucose levels. Sleep efficiency (P = .01, linear; P = .02, quadratic) and total sleep time (P = .01 linear; P = .02, quadratic) were inversely associated with glucose level. Morning glucose levels appear to be affected by the quality and quantity of overnight sleep in children who have sustained extensive burn injuries. Future research is needed to elucidate the metabolic and neuroendocrine consequences of sleep deprivation on metabolism after burns.

Mayes T; Gottschlich MM; Khoury J; Simakajornboon N; Kagan RJ

2013-09-01

98

Quantity and quality of nocturnal sleep affect morning glucose measurement in acutely burned children.  

Science.gov (United States)

Hyperglycemia after severe burn injury has long been recognized, whereas sleep deprivation after burns is a more recent finding. The postburn metabolic effects of poor sleep are not clear despite reports in other populations demonstrating the association between sleep insufficiency and deleterious endocrine consequences. The aim of this study was to determine whether a relationship between sleep and glucose dynamics exists in acutely burned children. Two overnight polysomnography runs (2200 to 0600) per subject were conducted in 40 patients with a mean (± SEM) age of 9.4?±?0.7 years, 50.1?±?2.9% TBSA burn, and 43.2?±?3.6% full-thickness injury. Serum glucose was drawn in the morning (0600) immediately after the sleep test. Insulin requirements during the 24-hour period preceding the 0600 glucose measurement were recorded. Generalized linear models were used by the authors to evaluate percent time in each stage of sleep, percent wake time, total sleep time, sleep efficiency, and morning serum glucose, accounting for insulin use. Increased time awake (P = .04, linear; P = .02, quadratic) and reduced time spent in stage 1 sleep (P = .03, linear) were associated with higher glucose levels. Sleep efficiency (P = .01, linear; P = .02, quadratic) and total sleep time (P = .01 linear; P = .02, quadratic) were inversely associated with glucose level. Morning glucose levels appear to be affected by the quality and quantity of overnight sleep in children who have sustained extensive burn injuries. Future research is needed to elucidate the metabolic and neuroendocrine consequences of sleep deprivation on metabolism after burns. PMID:23966118

Mayes, Theresa; Gottschlich, Michele M; Khoury, Jane; Simakajornboon, Narong; Kagan, Richard J

99

The effect of borate polymer layers on glucose measurement by surface plasmon resonance  

Science.gov (United States)

A new borate polymer PAA-ran-PAAPBA that can adsorb glucose specifically is introduced into the glucose measurement based on surface plasmon resonance. Six and twelve layers of borate polymer are bound onto the SPR sensors respectively through the layer-by-layer self-assembly binding method, and then the effect of different layers on the glucose concentration measurement is studied. The experiment is conducted in three concentration ranges, 1~10mg/dL, 10~100mg/dL and 100~1000mg/dL. The Results show that the performance of 12-layer-polymer sensor is better than that of the 6-layer-polymer sensor in the first two ranges, and the measuring result has no big difference in the range of 100~1000mg/d. It indicates that the enhancement of polymer layer on the surface of SPR sensor can dramatically improve the glucose measurement in the low concentration range.

Li, Dachao; Yang, Jia; Wu, Peng; Yang, Di; Wang, Bo; Lin, Yuan; Xu, Kexin

2013-03-01

100

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

Directory of Open Access Journals (Sweden)

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.

Rasouli R; Mahdavi R.; Ostad Rahimi A.R.

2012-01-01

 
 
 
 
101

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

UK PubMed Central (United Kingdom)

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 concentrations as low as 30 mg/dL, regardless of background solvent. These results are an important and encouraging step in the work towards developing a noninvasive in vivo glucose sensor in the mid-infrared.

Liakat S; Bors KA; Huang TY; Michel AP; Zanghi E; Gmachl CF

2013-07-01

102

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

1977-01-01

103

Advancement in polarimetric glucose sensing: simulation and measurement of birefringence properties of cornea  

Science.gov (United States)

Clinical guidelines dictate that frequent blood glucose monitoring in diabetic patients is critical towards proper management of the disease. Although, several different types of glucose monitors are now commercially available, most of these devices are invasive, thereby adversely affecting patient compliance. To this end, optical polarimetric glucose sensing through the eye has been proposed as a potential noninvasive means to aid in the control of diabetes. Arguably, the most critical and limiting factor towards successful application of such a technique is the time varying corneal birefringence due to eye motion artifact. We present a spatially variant uniaxial eye model to serve as a tool towards better understanding of the cornea's birefringence properties. The simulations show that index-unmatched coupling of light is spatially limited to a smaller range when compared to the index-matched situation. Polarimetric measurements on rabbits' eyes indicate relative agreement between the modeled and experimental values of corneal birefringence. In addition, the observed rotation in the plane of polarized light for multiple wavelengths demonstrates the potential for using a dual-wavelength polarimetric approach to overcome the noise due to timevarying corneal birefringence. These results will ultimately aid us in the development of an appropriate eye coupling mechanism for in vivo polarimetric glucose measurements.

Malik, Bilal H.; Coté, Gerard L.

2011-02-01

104

Measurement of ribosomal RNA turnover in vivo by use of deuterium-labeled glucose.  

UK PubMed Central (United Kingdom)

BACKGROUND: Most methods for estimation of rates of RNA production are not applicable in human in vivo clinical studies. We describe here an approach for measuring ribosomal RNA turnover in vivo using [6,6-(2)H(2)]-glucose as a precursor for de novo RNA synthesis. Because this method involves neither radioactivity nor toxic metabolites, it is suitable for human studies. METHODS: For method development in vitro, a lymphocyte cell line (PM1) was cultured in the presence of [6,6-(2)H(2)]-glucose. RNA was extracted, hydrolyzed enzymatically to ribonucleosides, and derivatized to either the aldonitrile tetra-acetate or the pentafluoro triacetate derivative of the pentose before GC-MS. We identified optimum derivatization and analysis conditions and demonstrated quantitative incorporation of deuterium from glucose into RNA of dividing cells. RESULTS: Pilot clinical studies demonstrated the applicability of this approach to blood leukocytes and solid tissues. A patient with chronic lymphocytic leukemia received [6,6-(2)H(2)]-glucose (1 g/kg) orally in aliquots administered every 30 min for a period of 10 h. When we analyzed CD3(-) B cells that had been purified by gradient centrifugation and magnetic-bead adhesion, we observed deuterium enrichment, a finding consistent with a ribosomal RNA production rate of about 7%/day, despite the slow division rates observed in concurrent DNA-labeling analysis. Similarly, in 2 patients with malignant infiltration of lymph nodes, administration of [6,6-(2)H(2)]-glucose (by intravenous infusion for 24 h) before excision biopsy allowed estimation of DNA and RNA turnover in lymph node samples. CONCLUSIONS: Our study results demonstrate the proof-of-principle that deuterium-labeled glucose may be used to analyze RNA turnover, in addition to DNA production/cell proliferation, in clinical samples.

Defoiche J; Zhang Y; Lagneaux L; Pettengell R; Hegedus A; Willems L; Macallan DC

2009-10-01

105

Design and Implementation of an Analog Video Signal Quality Measuring Software for Component Video Design och implementering av utvärderingsmjukvara för signalkvalitet i analog komponentvideo  

Digital Repository Infrastructure Vision for European Research (DRIVER)

An IP based set-top box (STB) is essentially a lightweight computer used to receive video over the Internet and convert it to analog or digital signals understood by the television. During this transformation from a digital image to an analog video signal many different types of distortions can occu...

Ljungström, Carl

106

Fasting glucose measurement as a potential first step screening for glucose metabolism abnormalities in women with anovulatory polycystic ovary syndrome.  

UK PubMed Central (United Kingdom)

STUDY QUESTION: Is routine screening by oral glucose tolerance test (OGTT) needed for all women with polycystic ovary syndrome (PCOS)? SUMMARY ANSWER: Screening for glucose metabolism abnormalities of PCOS patients by an OGTT could potentially be limited to patients who present with a fasting glucose concentration between 6.1 and 7.0 mmol/l only. WHAT IS KNOWN ALREADY: Women with PCOS are at increased risk of developing diabetes. This study proposes a stepwise screening strategy for (pre)diabetes for PCOS patients based on risk stratification by fasting plasma glucose. STUDY DESIGN, SIZE, DURATION: A cross-sectional study of 226 women diagnosed with anovulatory PCOS. PARTICIPANTS AND SETTING: A consecutive series of 226 patients, diagnosed with PCOS at the University Medical Centre Utrecht, the Netherlands, were screened for glucose metabolism abnormalities by OGTT (75 g glucose load). MAIN RESULTS AND ROLE OF CHANCE: The majority of the 226 women (mean age: 29.6 ± 4.3 years; BMI: 27.3 ± 6.7 kg/m(2); 81% Caucasian) presented with a normal OGTT (169 women (75%)). Of the 57 (25%) women presenting with mild to moderate glucose abnormalities, 53 (93%) could be identified by fasting glucose concentrations only. Diabetes was diagnosed in a total of eight women (3.5%). In six women, the diagnosis was based on fasting glucose >7.0 mmol/l. The other two cases of diabetes initially presented with fasting glucose between 6.1 and 7.0 mmol/l and were diagnosed by OGTT assessment. No women diagnosed with diabetes presented with fasting glucose levels below 6.1 mmol/l. We therefore conclude that all diabetes patients could potentially be found by initial fasting glucose assessment followed by OGTT only in patients with fasting glucose between 6.1 and 7.0 mmol/l. LIMITATIONS, REASONS FOR CAUTION: Before general implementation can be advised, this screening algorithm should be validated in a prospective study of a similar or greater number of PCOS women. WIDER IMPLICATIONS OF THE FINDINGS: Our study comprised of a mostly Caucasian (81%) population, therefore generalization to other ethnic populations should be done with caution. STUDY FUNDING/COMPETING INTEREST(S): No external finance was involved in this study. B.C.J.M.F. has received fees and grant support from the following companies (in alphabetic order); Andromed, Ardana, Ferring, Genovum, Merck Serono, MSD, Organon, Pantharei Bioscience, PregLem, Schering, Schering Plough, Serono and Wyeth. A.J.G. has received fees from Abbott, Bayer Schering and IBSA. T.W.H. has received fees from Merck, Sharpe & Dohme, GlaxoSmithKline, NovoNordisk and Eli Lilly. The authors declare complete independence from funders. CLINICAL TRIAL REGISTRATION NUMBER: NCT00821379.

Veltman-Verhulst SM; Goverde AJ; van Haeften TW; Fauser BC

2013-08-01

107

Does instantaneous blood glucose affect vibration perception threshold measurement using biothesiometer?  

UK PubMed Central (United Kingdom)

Diabetic neuropathy is a common and troublesome complication of diabetes mellitus. Vibration sensation is a measure of large fiber nerve conduction, which is very commonly affected in diabetes. The present study addresses the question of whether vibration perception threshold (VPT) measurement using a biothesiometer is reproducible under different levels of blood glucose at different hours of the day. Seventy-five diabetic patients, 31 insulin-dependent diabetes mellitus and 44 non-insulin-dependent diabetes mellitus, with mean age 50.33+/-14.22 years (21-70 years) and diabetes duration of 14.3+/-10.6 years (1-60 years) were included in the study. Forty-one patients were male and 34 were female. In conclusion, VPT was found to be reproducible under different blood glucose levels at different hours of the day, which is affected only by the height of the patient.

Damci T; O?ar Z; Beyhan S; Ilkova H; Ozyazar M; Gorpe U; Bagriacik N

1999-10-01

108

Does instantaneous blood glucose affect vibration perception threshold measurement using biothesiometer?  

Science.gov (United States)

Diabetic neuropathy is a common and troublesome complication of diabetes mellitus. Vibration sensation is a measure of large fiber nerve conduction, which is very commonly affected in diabetes. The present study addresses the question of whether vibration perception threshold (VPT) measurement using a biothesiometer is reproducible under different levels of blood glucose at different hours of the day. Seventy-five diabetic patients, 31 insulin-dependent diabetes mellitus and 44 non-insulin-dependent diabetes mellitus, with mean age 50.33+/-14.22 years (21-70 years) and diabetes duration of 14.3+/-10.6 years (1-60 years) were included in the study. Forty-one patients were male and 34 were female. In conclusion, VPT was found to be reproducible under different blood glucose levels at different hours of the day, which is affected only by the height of the patient. PMID:10580611

Damci, T; O?ar, Z; Beyhan, S; Ilkova, H; Ozyazar, M; Gorpe, U; Bagriacik, N

1999-10-01

109

The once-daily human glucagon-like peptide-1 (GLP-1) analog liraglutide improves postprandial glucose levels in type 2 diabetes patients.  

UK PubMed Central (United Kingdom)

INTRODUCTION: Fasting and postprandial plasma glucose (FPG, PPG) control are both necessary to achieve glycosylated hemoglobin (HbA(1c)) regulation goals. Liraglutide, based on its glucagon-like peptide 1 (GLP-1)-mediated pharmacology and pharmacokinetics may reduce HbA(1c) through both FPG and PPG levels. The objective of the present study was to investigate the effect of once-daily liraglutide (0.6, 1.2, and 1.8 mg) at steady state on FPG, PPG, postprandial insulin, and gastric emptying. METHODS: Eighteen subjects with type 2 diabetes, aged 18-70 years, with a body mass index of 18.5-40 kg/m(2) and HbA(1c) of 7.0%-9.5% were included in this single-centre, randomized, placebo-controlled, double-blind, two-period, cross over trial. Patients were randomized into two groups (A or B). Group A received oncedaily liraglutide for 3 weeks, followed by a 3-4-week washout period and 3 weeks of oncedaily placebo. Group B was treated as for Group A, but treatment periods were reversed (ie, placebo followed by liraglutide). A meal test was performed at steady-state liraglutide/placebo doses of 0.6, 1.2, and 1.8 mg/day. Plasma glucose, insulin, and paracetamol (acetaminophen) concentrations (to assess gastric emptying) were measured pre- and postmeal. RESULTS: PPG levels significantly decreased (P<0.001) after all three liraglutide doses when compared with placebo. This decrease was also apparent when corrected for baseline (incremental excursions), with the exception of average incremental increase calculated as area under the concentration curve (AUC) over the fasting value from time zero to 5 hours (iAUC (0-5 h)/5 hours) after liraglutide 0.6 mg, where there was a trend to decrease (P=0.082). In addition, FPG levels significantly decreased at all three liraglutide dose levels when compared to placebo (P<0.001). Fasting and postprandial insulin levels significantly increased with liraglutide versus placebo at all doses studied (P<0.001). A significant delay in gastric emptying during the first hour postmeal was observed at the two highest liraglutide doses versus placebo. CONCLUSION: In addition to lowering FPG levels, liraglutide improves PPG levels (absolute and incremental) possibly by both stimulating postprandial insulin secretion and delaying gastric emptying.

Flint A; Kapitza C; Hindsberger C; Zdravkovic M

2011-03-01

110

A Fluorescence Method for Measurement of Glucose Transport in Kidney Cells  

Science.gov (United States)

Abstract Background Diabetes may alter renal glucose reabsorption by sodium (Na+)-dependent glucose transporters (SGLTs). Radiolabeled substrates are commonly used for in vitro measurements of SGLT activity in kidney cells. We optimized a method to measure glucose uptake using a fluorescent substrate, 2-(N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)amino)-2-deoxyglucose (2-NBDG). Methods Uptake buffers for 2-NBDG were the same as for 14C-labeled ?-methyl-d-glucopyranoside ([14C]AMG). Cell lysis buffer was optimized for fluorescence of 2-NBDG and Hoechst DNA stain. Uptake was performed on cultures of primary mouse kidney cells (PMKCs), the LLC-PK1 proximal tubule cell line, or COS-7 cells transiently overexpressing mouse SGLT1 or SGLT2 by incubating cells at 37°C in buffer containing 50–200??M 2-NBDG. Microscopy was performed to visualize uptake in intact cells, while a fluorescence microplate reader was used to measure intracellular concentration of 2-NBDG ([2-NBDG]i) in cell homogenates. Results Fluorescent cells were observed in cultures of PMKCs and LLC-PK1 cells exposed to 2-NBDG in the presence or absence of Na+. In LLC-PK1 cells, 2-NBDG transport in the presence of Na+ had a maximum rate of 0.05?nmol/min/?g of DNA. In these cells, Na+-independent uptake of 2-NBDG was blocked with the GLUT inhibitor, cytochalasin B. The Na+-dependent uptake of 2-NBDG decreased in response to co-exposure to the SGLT substrate, AMG, and it could be blocked with the SGLT inhibitor, phlorizin. Immunocytochemistry showed overexpression of SGLT1 and SGLT2 in COS-7 cells, in which, in the presence of Na+, [2-NBDG]i was fivefold higher than in controls. Conclusion Glucose transport in cultured kidney cells can be measured with the fluorescence method described in this study.

Blodgett, Amy B.; Kothinti, Rajendra K.; Kamyshko, Ivan; Petering, David H.; Kumar, Suresh

2011-01-01

111

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

Energy Technology Data Exchange (ETDEWEB)

While the results of regional myocardial glucose metabolism measurements using positron emission computed tomography (/sup 13/N-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.

Schelbert, H.R.; Phelps, M.E.

1980-06-01

112

One hour versus two hours postprandial glucose measurement in gestational diabetes: a prospective study.  

UK PubMed Central (United Kingdom)

OBJECTIVE: To compare the rate of adverse perinatal outcomes among women with gestational diabetes mellitus (GDM), monitored by 1 versus 2 hour-postprandial glucose (PPG) measurements. METHODS: A total of 112 women diagnosed with GDM, by the criteria of Carpenter-Coustan, were included in the study population. Women were recruited from two different treatment settings, but were managed by the same team of health-care professionals using a standardized protocol. Allocation to treatment group was based on treatment setting. Glucose levels were measured fasting, and either 1 hour (1-hour monitoring group-target values <140 mg/dl) or 2 hours (2-hour monitoring group-target values <120 mg/dl) postprandially. Demographic data and perinatal outcomes were collected from their medical records. RESULTS: In all, 66 women were assigned to 1-hour monitoring group (1 h-PPG) and 46 women to 2-hour monitoring group (2 h-PPG). There were no differences in parity, family history of diabetes, rate of GDM in previous pregnancies, weight gain, pregestational BMI and 50-g-glucose challenge test (GCT) and 100-g oral glucose challenge test (OGTT) results. As expected, there was a significant difference in mean blood glucose levels between the two groups (108.1+/-19.2 and 94.9+/-21.2 mg/dl, 1- and 2 hours, respectively, p<0.0001); however, HbA1C levels were similar in the two groups. Perinatal outcomes were defined as gestational week at delivery; fetal weight (3325+/-471 vs 3309+/-608 g, respectively) and percentile (47.2+/-27 vs 49.6+/-30, respectively), and were similar for both groups. Insulin therapy was initiated more frequently in 2-hour monitoring group (28 and 40% of women in groups 1 and 2, respectively; p<0.05). Rates of macrosomia (7.5 versus 10.6%), large for gestational age (7.4 versus 15.2%), and delivery by cesarean section (24 versus 30%) were increased in group 2 (2 h-PPG) but these differences did not reach statistical significance. CONCLUSION: These data suggest that diet control in women with GDM managed by 1-hour PPG measurements is associated with a decreased rate of insulin therapy. However, neonatal and obstetrical outcomes are not determined by the timing of their glucose determinations.

Weisz B; Shrim A; Homko CJ; Schiff E; Epstein GS; Sivan E

2005-04-01

113

Measurement Quality of Blood Glucose Meters: Is There a Need for an Institution with an Unbiased View?  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The quality of self-monitoring of blood glucose (SMBG) with modern blood glucose meters is considered by many as not being a relevant topic anymore. However, in reality, a number of open questions about the quality of the measurement exists. Even if the meters fulfill the established quality criteri...

Heinemann, Lutz

114

Reproducibility of cerebral glucose utilization measured by positron emission tomography and the [18F]-2-fluoro-2-deoxy-d-glucose method in resting, healthy human subjects  

International Nuclear Information System (INIS)

The stability of cerebral glucose utilization was examined in nine right-handed, healthy men (age, 24.88±2.93 years) using positron emission tomography (PET) and the [18F]-fluorodeoxyglucose (FDG) method. Each study was run twice at intervals of 1-12 weeks with the subject at rest. The average cerebral metabolic rate for glucose (CMRGlu) was 5.40±0.71 mg/100 g per min (coefficient of variance, 13.08). The average intraindividual variation of CMRGlu was 7.91%±15.46% (P=0.13). Metabolic indices (MI: Regional/mean cortical CMRGlu) were used to determine the regional cerebral metabolic distribution. The interindividual (coefficient of variance, 7.13) and intraindividual variabilities (average variation, -0.12%±8.76%) of MI were smaller than those of metabolic rates. No reproducible significant asymmetry was observed. The FDG method used with subjects at rest thus yields low intraindividual variability of both cerebral glucose consumption and regional metabolic distribution, even at an interval of several weeks. Cerebral glucose utilization measured under such conditions may act as a reliable reference for determination of the influences of physiological (activation), pharmacological or pathological processes on cerebral glucose metabolism. (orig.).

1990-01-01

115

Blood glucose measurement for flap monitoring to salvage flaps from venous thrombosis.  

UK PubMed Central (United Kingdom)

Early detection and rapid re-exploration are important for flap salvage, and for this, a reliable monitoring method is required. The purpose of the current study was to evaluate blood glucose measurement (BGM) for flap monitoring and to establish a simple method that can be used widely to decrease the flap loss rate after tissue transplantation. We noted the BGM in 33 free or pedicled tissue transfers (57 BGM points) over time postoperatively. Skin punctures and blood glucose measurements were made using a Medisafe-finetouch needle and Medisafe-Mini (Terumo, Japan), which are commonly used by diabetic patients. Partial necrosis of the vascular territory was found at 5 points (9%), and blood flow disorder due to a venous thrombus was found at 5 points (9%). The mean blood glucose level in the congestive flaps was significantly lower than that in healthy flaps. ROC curve analysis was used to determine a cutoff value for BGM of 62 mg/dL, at which the sensitivity and specificity were 88% and 82%, respectively (p < 0.0001). In conclusion, BGM is an easy and accessible adjunct to flap monitoring, and the combination of BGM and previously established methods is likely to reduce postoperative complications caused by the development of a venous thrombus after free tissue transplantation.

Hara H; Mihara M; Iida T; Narushima M; Todokoro T; Yamamoto T; Koshima I

2012-05-01

116

Blood glucose measurement for flap monitoring to salvage flaps from venous thrombosis.  

Science.gov (United States)

Early detection and rapid re-exploration are important for flap salvage, and for this, a reliable monitoring method is required. The purpose of the current study was to evaluate blood glucose measurement (BGM) for flap monitoring and to establish a simple method that can be used widely to decrease the flap loss rate after tissue transplantation. We noted the BGM in 33 free or pedicled tissue transfers (57 BGM points) over time postoperatively. Skin punctures and blood glucose measurements were made using a Medisafe-finetouch needle and Medisafe-Mini (Terumo, Japan), which are commonly used by diabetic patients. Partial necrosis of the vascular territory was found at 5 points (9%), and blood flow disorder due to a venous thrombus was found at 5 points (9%). The mean blood glucose level in the congestive flaps was significantly lower than that in healthy flaps. ROC curve analysis was used to determine a cutoff value for BGM of 62 mg/dL, at which the sensitivity and specificity were 88% and 82%, respectively (p < 0.0001). In conclusion, BGM is an easy and accessible adjunct to flap monitoring, and the combination of BGM and previously established methods is likely to reduce postoperative complications caused by the development of a venous thrombus after free tissue transplantation. PMID:22153849

Hara, Hisako; Mihara, M; Iida, T; Narushima, M; Todokoro, T; Yamamoto, T; Koshima, I

2011-12-08

117

Hematocrit interference of blood glucose meters for patient self-measurement.  

UK PubMed Central (United Kingdom)

BACKGROUND: Abnormal hematocrit levels may interfere with glucose readings of patient self-assessment blood glucose (BG) meters. The aim of this laboratory investigation was to assess the potential influence of hematocrit variations on a variety of BG meters applying different measurement technologies. METHODS: Venous heparinized blood was manipulated to contain three different BG concentrations (50-90, 120-180, and 280-350 mg/dl) and five different hematocrit levels (25%, 35%, 45%, 55%, and 65%). After careful oxygenation to normal blood oxygen pressure (65-100 mmHg), each sample was measured (eight times) with the following devices: Accu-Chek® Aviva Nano and Active, Breeze®2 and Contour®, FreeStyle Freedom Lite®, GlucoDr. auto™, Glucofix® mio Plus, GlucoLab™, GlucoMen® LX Plus, Nova Max® Link, Nova Max® Plus, OneTouch® Ultra®2 and Verio®, On Call® Plus and Platinum, Optium Xceed®, Precision Xceed®, and TaiDoc Fora TD-4227. A YSI 2300 STAT Plus™ glucose analyzer served as reference method. Stability to hematocrit influence was assumed, with <10% mean glucose result bias between the highest and lowest hematocrit levels. RESULTS: Six of the investigated meters showed a stable performance in this investigation: Accu-Chek Active (7%), Glucofix mio Plus (5%), GlucoMen LX Plus (4%), Nova Max Plus (4%), Nova Max Link (7%), and OneTouch Verio (3%). All other meters failed this hematocrit interference test, with FreeStyle Freedom Lite (11%), and On Call Platinum (12%) being the better devices and On Call Plus (68%), GlucoLab (51%), TaiDoc Fora TD-4227 (39%), and Breeze 2 (38%) showing the worst performance. CONCLUSIONS: Hematocrit may affect BG meter performance in daily routine. In case of interference, low hematocrit values (<35%) result in too high readings. Our results encourage use of meters that are not affected by hematocrit interference.

Ramljak S; Lock JP; Schipper C; Musholt PB; Forst T; Lyon M; Pfützner A

2013-01-01

118

Dynamic electrochemistry corrects for hematocrit interference on blood glucose determinations with patient self-measurement devices.  

UK PubMed Central (United Kingdom)

BACKGROUND: It has been demonstrated that dynamic electrochemistry can be used to correct blood glucose measurement results for potentially interfering conditions, such as humidity, hematocrit (HCT) variations, and ascorbic acid. The purpose of this laboratory investigation was to assess the potential influence of hematocrit variations on a variety of blood glucose meters applying different measurement technologies. METHODS: Venous heparinized whole blood was drawn, immediately aliquoted, and manipulated to contain three different blood glucose concentrations (80, 155, and 310 mg/dl) and five different hematocrit levels (25%, 37%, 45%, 52%, and 60%). After careful oxygenation to normal blood oxygen pressure, each of the resulting 15 different samples was measured 8 times with the following devices: BGStar, Contour, Accu-Chek Aviva, Accu-Chek Aviva Nano, Breeze 2, Precision Xceed, OneTouch Ultra 2, OneTouch Verio, FreeStyle Freedom Lite, Glucocard G+, GlucoMen LX, GlucoMen GM, and StatStrip [point-of-care (POC) device]. Cobas (Roche Diagnostics, glucose hexokinase method) served as laboratory plasma reference method. Stability to hematocrit influence was assumed when less than 10% bias occurred between the highest and lowest hematocrit levels when analyzing mean deviations for all three glucose concentrations. RESULTS: Besides the POC StatStrip device, which is known to measure and correct for hematocrit (resulting in <2% bias), four self-test meters also showed a stable performance in this investigation: dynamic electrochemistry, BGStar (8%), and static electrochemistry, Contour (6%), Glucocard G+ (2%), and OneTouch Verio (6%). The other meters failed this test: colorimetry, FreeStyle Freedom Lite (16%), and static electrochemistry, Accu-Chek Aviva (23%), Accu-Chek Aviva Nano (18%), Breeze 2 (36%), OneTouch Ultra 2 (34%), Precision Xceed (34%), GlucoMen LX (24%), and GlucoMen GM (31%). CONCLUSIONS: As hematocrit variations occur in daily routine (e.g., because of smoking, exercise, hypermenorrhea, pregnancy, stay in mountains, and hemodialysis), our results may encourage use of meters with stable performance under these conditions. Dynamic electrochemistry as used in the BGStar device (sanofi-aventis) appears to be an effective technology to correct for potential hematocrit influence on the meter results.

Musholt PB; Schipper C; Thomé N; Ramljak S; Schmidt M; Forst T; Pfützner A

2011-09-01

119

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

DEFF Research Database (Denmark)

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.

Börjesson, Karl; Preus, SØren

2009-01-01

120

Complementary Bandwidth Extension Method Using Analog Forward and Digital Inverse Filters and Its Application to Noncontact ECG Measurement  

Science.gov (United States)

In this paper, we propose a novel method for extending bandwidth of ECG measuring device without deteriorating the baseline tolerance for body motion. The proposed method is realized by synthesizing a two-stage analog forward filter with two different corner frequencies and a digital inverse filter having a corner frequency identical with the higher one of the analog filter. We applied the method to bed-type capacitive ECG sensor which can detect electrocardiographic potential non-intrusively and indirectly. The results demonstrated that the proposed method could precisely recover low-frequency components like T-wave. Furthermore, we confirmed that QTc (corrected QT interval) could be estimated from the recovered wave and that the QTc correlated 0.81 on the average with that obtained from Lead II ECG for seven subjects. These results indicate that the proposed method is useful to screening of long QT syndrome by combining the method with the bed-type capacitive ECG sensor.

Kowada, Daisuke; Ueno, Akinori

 
 
 
 
121

Non-Invasive Glucose Measurement by Use of Metabolic Heat Conformation Method  

Directory of Open Access Journals (Sweden)

Full Text Available A non-invasive glucose measurement system based on the method of metabolic heat conformation (MHC) is presented in this paper. This system consists of three temperature sensors, two humidity sensors, an infrared sensor and an optical measurement device. The glucose level can be deduced from the quantity of heat dissipation, blood flow rate of local tissue and degree of blood oxygen saturation. The methodology of the data process and the measurement error are also analyzed. The system is applied in a primary clinical test. Compared with the results of a commercial automated chemistry analyzer, the correlation coefficient of the collected data from the system is 0.856. Result shows that the correlation coefficient improves when the factor of heat dissipated by evaporation of the skin is added in. A non-invasive method of measuring the blood flow rate of local tissue by heat transmission between skin and contacted conductor is also introduced. Theoretical derivation and numerical simulation are completed as well. The so-called normalized difference mean (NDM) is chosen to express the quantity of the blood flow rate. The correlation coefficient between the blood flow rates by this method and the results of a Doppler blood flow meter is equal to 0.914.

Fei Tang; Xiaohao Wang; Dongsheng Wang; Junfeng Li

2008-01-01

122

Iris as a reflector for differential absorption low-coherence interferometry to measure glucose level in the anterior chamber  

Science.gov (United States)

We present a method of glucose concentration detection in the anterior chamber with a differential absorption optical low-coherent interferometry (LCI) technique. Back-reflected light from the iris, passing through the anterior chamber twice, was selectively obtained with the LCI technique. Two light sources, one centered within (1625 nm) and the other centered outside (1310 nm) of a glucose absorption band were used for differential absorption measurement. In the eye model and pig eye experiments, we obtained a resolution glucose level of 26.8 mg/dL and 69.6 mg/dL, respectively. This method has a potential application for noninvasive detection of glucose concentration in aqueous humor, which is related to the glucose concentration in blood.

Zhou, Yong; Zeng, Nan; Ji, Yanhong; Li, Yao; Dai, Xiangsong; Li, Peng; Duan, Lian; Ma, Hui; He, Yonghong

2011-01-01

123

Measurement and modeling of solubilities of D-glucose in water/alcohol and alcohol/alcohol systems  

Energy Technology Data Exchange (ETDEWEB)

In this work, the solubilities of D-glucose in water/methanol and ethanol/methanol mixtures are measured at 40 and 60 C, using a simple and accurate analytical method. A modified UNIQUAC model is used for the correlation of the experimental solubility data. New UNIQUAC interaction parameters for the pairs D-glucose/alcohol, water/alcohol, and alcohol/alcohol are estimated based on the ternary solubility data presented in this work together with those available in the literature for D-glucose in water/ethanol. The solubility calculations were performed using an equation based on enthalpy of fusion data for D-glucose. The model describes satisfactorily the experimental solubility data of D-glucose in water/ethanol, water/methanol, and ethanol/methanol mixtures at both temperatures.

Peres, A.M.; Macedo, E.A.

1997-07-01

124

Measurement of glucose metabolism in rat spinal cord slices with dynamic positron autoradiography  

International Nuclear Information System (INIS)

We attempted to measure the regional metabolic rate of glucose (MRglc) in sliced spinal cords in vitro. The thoracic spinal cord of a mature Wister rat was cut into 400-?m slices in oxygenated and cooled (1-4 deg. C) Krebs-Ringer solution. After at least 60 min of preincubation, the spinal cord slices were transferred into double polystyrene chambers and incubated in Krebs-Ringer solution at 36 deg. C, bubbled with 5% O2/5% CO2 gas. To measure MRglc, we used the dynamic positron autoradiography technique (dPAT) with F-18-2-fluoro-2-deoxy-D-glucose ([18F]FDG) and the net influx constant of [18F]FDG as an index. Uptake curves of [18F]FDG were well fitted by straight lines for more than 7 h after the slicing of the spinal cord (linear regression coefficient, r=0.99), indicating a constant uptake of glucose by the spinal cord tissue. The slope (K), which denotes MRglc, is affected by tetrodotoxin, and high K+ (50 mM) or Ca2+-free, high Mg2+ solution. After 10 min of hypoxia, the K value following reoxygenation was similar to the unloaded control value, but after 45 min of hypoxia, the K value was markedly lower than the unloaded control value, and after >90 min of reoxygenation it was nearly 0. Our results indicate that the living spinal cord slices used retained an activity-dependent metabolism to some extent. This technique may provide a new approach for measuring MRglc in sliced living spinal cord tissue in vitro and for quantifying the dynamic changes in MRglc in response to various interventions such as hypoxia.

2009-01-01

125

Underestimation of glucose turnover measured with (6-/sup 3/H)- and (6,6-/sup 2/H)- but not (6-/sup 14/C)glucose during hyperinsulinemia in humans  

Energy Technology Data Exchange (ETDEWEB)

Recent studies indicate that hydrogen-labeled glucose tracers underestimate glucose turnover in humans under conditions of high flux. The cause of this underestimation is unknown. To determine whether the error is time-, pool-, model-, or insulin-dependent, glucose turnover was measured simultaneously with (6-3H)-, (6,6-2H2)-, and (6-14C)glucose during a 7-h infusion of either insulin (1 mU.kg-1.min-1) or saline. During the insulin infusion, steady-state glucose turnover measured with both (6-3H)glucose (8.0 +/- 0.5 mg.kg-1.min-1) and (6,6-2H2)glucose (7.6 +/- 0.5 mg.kg-1.min-1) was lower (P less than .01) than either the glucose infusion rate required to maintain euglycemia (9.8 +/- 0.7 mg.kg-1.min-1) or glucose turnover determined with (6-14C)glucose and corrected for Cori cycle activity (9.8 +/- 0.7 mg.kg-1.min-1). Consequently negative glucose production rates (P less than .01) were obtained with either (6-3H)- or (6,6-2H2)- but not (6-14C)glucose. The difference between turnover estimated with (6-3H)glucose and actual glucose disposal (or 14C glucose flux) did not decrease with time and was not dependent on duration of isotope infusion. During saline infusion, estimates of glucose turnover were similar regardless of the glucose tracer used. High-performance liquid chromatography of the radioactive glucose tracer and plasma revealed the presence of a tritiated nonglucose contaminant. Although the contaminant represented only 1.5% of the radioactivity in the (6-3H)glucose infusate, its clearance was 10-fold less (P less than .001) than that of (6-3H)glucose. This resulted in accumulation in plasma, with the contaminant accounting for 16.6 +/- 2.09 and 10.8 +/- 0.9% of what customarily is assumed to be plasma glucose radioactivity during the insulin or saline infusion, respectively (P less than .01).

McMahon, M.M.; Schwenk, W.F.; Haymond, M.W.; Rizza, R.A.

1989-01-01

126

Accuracy in Blood Glucose Measurement: What Will a Tightening of Requirements Yield?  

Science.gov (United States)

Nowadays, almost all persons with diabetes—at least those using antidiabetic drug therapy—use one of a plethora of meters commercially available for self-monitoring of blood glucose. The accuracy of blood glucose (BG) measurement using these meters has been presumed to be adequate; that is, the accuracy of these devices was not usually questioned until recently. Health authorities in the United States (Food and Drug Administration) and in other countries are currently endeavoring to tighten the requirements for the accuracy of these meters above the level that is currently stated in the standard ISO 15197. At first glance, this does not appear to be a problem and is hardly worth further consideration, but a closer look reveals a considerable range of critical aspects that will be discussed in this commentary. In summary, one could say that as a result of modern production methods and ongoing technical advances, the demands placed on the quality of measurement results obtained with BG meters can be increased to a certain degree. One should also take into consideration that the system accuracy (which covers many more aspects as the analytical accuracy) required to make correct therapeutical decisions certainly varies for different types of therapy. At the end, in addition to analytical accuracy, thorough and systematic training of patients and regular refresher training is important to minimize errors. Only under such circumstances will patients make appropriate therapeutic interventions to optimize and maintain metabolic control.

Heinemann, Lutz; Lodwig, Volker; Freckmann, Guido

2012-01-01

127

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

UK PubMed Central (United Kingdom)

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

Tsai CY; Lee SC; Hung CC; Lee JJ; Kuo MC; Hwang SJ; Chen HC

2010-05-01

128

Interaction of fructose with the glucose permease of the cyanobacterium Synechocystis sp. strain PCC 6803  

Energy Technology Data Exchange (ETDEWEB)

Fructose was bactericidal for the cyanobacterium Synechocystis sp. strain PCC 6803. Each of ten independently isolated fructose-resistant mutants had an alteration of the glucose transport system, measured as uptake of glucose or of 3-0-methyl-D-glucose. In the presence of the analog, the wild-type Synechocystis strain was protected against fructose. Two mutants altered in photoautotrophy were also isolated.

Flores, E.; Schmetterer, G.

1986-05-01

129

51 Ophiuchus: A Possible Beta Pictoris Analog Measured with the Keck Interferometer Nuller  

Science.gov (United States)

We present observations of the 51 Ophiuchi circumstellar disk made with the Keck interferometer operating in nulling mode at N band. We model these data simultaneously with VLTI-MIDI visibility data and a Spitzer IRS spectrum using a variety of optically thin dust cloud models and an edge-on optically thick disk model. We find that single-component optically thin disk models and optically thick disk models are inadequate to reproduce the observations, but an optically thin two-component disk model can reproduce all of the major spectral and interferometric features. Our preferred disk model consists of an inner disk of blackbody grains extending to ~4 AU and an outer disk of small silicate grains extending out to ~1200 AU. Our model is consistent with an inner "birth" disk of continually colliding parent bodies producing an extended envelope of ejected small grains. This picture resembles the disks around Vega, AU Microscopii, and ? Pictoris, supporting the idea that 51 Ophiuchius may be a ? Pictoris analog.

Stark, Christopher C.; Kuchner, Marc J.; Traub, Wesley A.; Monnier, John D.; Serabyn, Eugene; Colavita, Mark; Koresko, Chris; Mennesson, Bertrand; Keller, Luke D.

2009-10-01

130

51 OPHIUCHUS: A POSSIBLE BETA PICTORIS ANALOG MEASURED WITH THE KECK INTERFEROMETER NULLER  

International Nuclear Information System (INIS)

[en] We present observations of the 51 Ophiuchi circumstellar disk made with the Keck interferometer operating in nulling mode at N band. We model these data simultaneously with VLTI-MIDI visibility data and a Spitzer IRS spectrum using a variety of optically thin dust cloud models and an edge-on optically thick disk model. We find that single-component optically thin disk models and optically thick disk models are inadequate to reproduce the observations, but an optically thin two-component disk model can reproduce all of the major spectral and interferometric features. Our preferred disk model consists of an inner disk of blackbody grains extending to ?4 AU and an outer disk of small silicate grains extending out to ?1200 AU. Our model is consistent with an inner 'birth' disk of continually colliding parent bodies producing an extended envelope of ejected small grains. This picture resembles the disks around Vega, AU Microscopii, and ? Pictoris, supporting the idea that 51 Ophiuchius may be a ? Pictoris analog.

2009-10-01

131

[Use of an automatic blood glucose measurement system for the assessment of insulin resistance during the oral glucose tolerance test  

UK PubMed Central (United Kingdom)

An automatic glycemic control system (Beta-like, Esaote) was used to calculate the insulin area (IA) required to keep glycemia within the normal range during OGTT (using NDDG criteria). IA was calculated by adding total endogenous insulin to insulin infused by the Betalike system (Actrapid HM, Novo). During the test, glycemia was obliged to follow a mean normal curve using an insulin infusion according to a special algorithm which automatically adapted to individual parameter variations during the different stages of OGTT. Fourteen blood samples were collected to assay metabolites (glucose, NEFA, lactate and alanine) and hormones (insulin, C peptide, glucagon). Data on insulinemia and glycemia were used to calculate the respective areas under the total and incremental curve (IA expressed in UL-1 min-1 and GA expressed in mM.L-1.min-1); an insulin resistance index was then calculated (total and incremental) using the following formula: IA/(normal GA/patient GA). This test allows us: a) to evaluate the insulin secretory response to a standard glycemic stimulus represented by a glycemic curve within the normal range; b) to calculate the quantity of insulin necessary to maintain the glycemic curve within the normal range; c) to evaluate the body's total insulin resistance according to an index calculated on the basis of the insulin area required; d) to compare the calculated insulin resistance index with NEFA and glucagon data obtained during the test; e) to identify the exact evolution of these events over time during OGTT.

Volpicelli G; Battista S; Caraffa F; Campione R; Iannello S; Belfiore F

1990-10-01

132

Review of adverse events associated with false glucose readings measured by GDH-PQQ-based glucose test strips in the presence of interfering sugars.  

UK PubMed Central (United Kingdom)

OBJECTIVE: To assess the implications of falsely elevated glucose readings measured with glucose dehydrogenase pyrroloquinolinequinone (GDH-PQQ) test strips. RESEARCH DESIGN AND METHODS: We conducted a review of the Food and Drug Administration's Manufacturer and User Facility Device Experience database and medical literature for adverse events (AEs) associated with falsely elevated glucose readings with GDH-PQQ test strips in the presence of interfering sugars. RESULTS: Eighty-two reports were identified: 16 (20%) were associated with death, 46 (56%) with severe hypoglycemia, and 12 (15%) with nonsevere hypoglycemia. In eight reports (10%), the AE was not described. Forty-two events (51%) occurred in the U.S. Although most events occurred in hospitalized patients, at least 14 (17%) occurred in outpatients. Agents most commonly associated with AEs were icodextrin-containing peritoneal dialysate and maltose-containing intravenous immune globulin. CONCLUSIONS: GDH-PQQ test strips pose a safety risk to insulin-using patients treated with agents containing or metabolized to interfering sugars.

Frias JP; Lim CG; Ellison JM; Montandon CM

2010-04-01

133

Analog Frequency Tracking Filter  

Directory of Open Access Journals (Sweden)

Full Text Available This paper propose a new type of analog adaptive filter derived as a generalization of the concept of matched filter. We conceive such a filter to track the instantaneous frequency of frequency modulated signals. Some properties of the proposed analog frequency tracking filter are established using the time-frequency representations theory. A constructive solution, based on common analog integrated circuits, is also proposed. The performance of the analog frequency tracking filter built is evaluated by measurements. Finally, some possible applications are highlighted.

ISAR, A.; ISAR, D.

2013-01-01

134

Development of a rapid method for the measurement of lactose in milk using a blood glucose biosensor.  

UK PubMed Central (United Kingdom)

Current methods for lactose measurement in dairy products are time consuming and tedious and may require expensive equipment and skilled technicians. The aim of this research was to develop a novel and rapid method for the routine measurement of lactose in dairy products. The proposed method is based on the rapid hydrolysis of lactose using ?-galactosidase and subsequently measuring glucose using a blood glucose meter. Blood glucose meters were developed after decades of research and clinical trials and are used extensively worldwide by individuals with diabetes to monitor their blood glucose levels. The method was developed and validated in a series of experiments. In the first experiment, temperature and time required for the near-complete hydrolysis of lactose were determined. Subsequently, the influence of glucose meters and their test strip lots were evaluated. We found that meters were not significantly different. However, the test strip lots were significantly different from each other. In the second experiment, the proposed method was validated using different concentrations of lactose solutions (1.9-6.5%) and compared with a HPLC-based reference method. In the third experiment, the proposed method was used to determine the lactose content of raw milk. The proposed method shows potential for rapid, routine, and low-cost measurement of lactose in milk and other dairy products.

Amamcharla JK; Metzger LE

2011-10-01

135

Development of a rapid method for the measurement of lactose in milk using a blood glucose biosensor.  

Science.gov (United States)

Current methods for lactose measurement in dairy products are time consuming and tedious and may require expensive equipment and skilled technicians. The aim of this research was to develop a novel and rapid method for the routine measurement of lactose in dairy products. The proposed method is based on the rapid hydrolysis of lactose using ?-galactosidase and subsequently measuring glucose using a blood glucose meter. Blood glucose meters were developed after decades of research and clinical trials and are used extensively worldwide by individuals with diabetes to monitor their blood glucose levels. The method was developed and validated in a series of experiments. In the first experiment, temperature and time required for the near-complete hydrolysis of lactose were determined. Subsequently, the influence of glucose meters and their test strip lots were evaluated. We found that meters were not significantly different. However, the test strip lots were significantly different from each other. In the second experiment, the proposed method was validated using different concentrations of lactose solutions (1.9-6.5%) and compared with a HPLC-based reference method. In the third experiment, the proposed method was used to determine the lactose content of raw milk. The proposed method shows potential for rapid, routine, and low-cost measurement of lactose in milk and other dairy products. PMID:21943731

Amamcharla, J K; Metzger, L E

2011-10-01

136

Measurement of temporal asymmetries of glucose consumption using linear profiles: reproducibility and comparison with visual analysis  

International Nuclear Information System (INIS)

[en] The aim of our study was to test the reproducibility of this method and to compare its diagnostic performance to that of visual analysis in patients with complex partial seizures (CPS). Regional cerebral glucose consumption (rCMRGLc) was measured interictally in 25 CPS patients and 10 controls using F-18-deoxyglucose and the positron emission tomography (PET) camera ECAT EXACT 47. The PET scans were visually analyzed for the occurrence of unilateral temporal hypometabolism. Furthermore, rCMRGLc was quantified on six contiguous coronal planes by manually tracing maximal values of temporal glucose consumption, thus creating line profiles of temporal glucose consumption for each side. Indices of asymmetry (ASY) were then calculated from these line profiles in four temporal regions and compared to the corresponding 95% confidence intervals of the control data. All analyses were performed by two observers independently from each other and without knowledge of the clinical findings. The agreement between the two observers with regard to focus lateralization was 96% on visual analysis and 100% on quantitative analysis. There was an excellent agreement with regard to focus lateralization between visual and quantitative evaluation. (orig.)[de] Das Ziel unserer Studie war die Ueberpruefung der Reproduzierbarkeit dieser Methode und der Vergleich der diagnostischen Leistungsfaehigkeit dieses Verfahrens mit derjenigen der visuellen Analyse bei Patienten mit komplex partiellen Anfaellen (CPS). Der regionale zerebrale Glukoseverbrauch (rCMRGlc) wurde interiktal bei 25 CPS-Patienten und 10 Kontrollen mit 18-F-Fluorodeoxyglukose (FDG) und der PET-Kamera ECAT EXACT 47 gemessen. Die PET-Aufnahmen wurden visuell auf unilateralen temporalen Hypometabolismus hin beurteilt. Weiterhin wurde der rCMRGLc auf sechs koronaren Schichten mit Hilfe manuell gezeichneter Linienprofile quantifiziert. Aus diesen Profilen wurden Asymmetrieindizes (ASY) in vier temporalen Regionen berechnet und mit den 95%-Konfidenzintervallen des Kontrollkollektivs verglichen. Alle Analysen wurden unabhaengig von zwei Auswertern ohne Kenntnis der klinischen Daten ausgefuehrt. Die Uebereinstimmung zwischen den beiden Auswertern in Hinsicht auf die Fokus-Lateralisierung war 96% fuer die visuelle und 100% fuer die quantitative Analyse. Die Uebereinstimmung zwischen der visuellen und quantitativen war gut. (orig.)

1998-01-01

137

Variability in measurements of blood glucose response to foods in human subjects is not reduced after a standard breakfast.  

UK PubMed Central (United Kingdom)

Measurements of blood glucose response to food are highly variable. We determined whether within-individual variability in data for blood glucose responses were reduced if individuals consumed a standard meal 2 hours before testing and investigated the effect of serving size. Blood glucose responses to muesli and macaroni cheese were determined in 13 individuals by taking 2 fasting capillary blood samples. Food was then consumed, and capillary blood samples were taken every 15 minutes for the first hour and every 30 minutes for the second hour. The incremental area under the blood glucose response curve was determined, and glycemic glucose equivalents (GGEs) were calculated. The GGE values were not significantly different whether the muesli and macaroni cheese were fed fasting or after a standard breakfast (29.2 vs 34.5 g for muesli and 11.0 vs 14.6 g for macaroni cheese). Within-individual coefficients of variation were not significantly different whether the food was consumed fasting or after a standard breakfast (24.9% and 32.5% for muesli and 38.1% and 59.4% for macaroni cheese). Differences in GGE between measured and estimated half serving size for macaroni cheese were 0.8 g (P = .6) and for muesli, 3 g (P = .2); for the double serving size for macaroni cheese, 1.7 g (P = .7); and for muesli, 6.7 g (P = .06). The GGE values for foods and variability in blood glucose response within individuals were not significantly different whether individuals fasted or consumed a standard breakfast before testing. However, blood glucose levels tended to differ significantly after consumption of the double serving size of muesli compared with other serving sizes.

Wallace AJ; Eady SL; Willis JA; Scott RS; Monro JA; Frampton CM

2009-04-01

138

Measurement and Control in Industrial Processes Using an Analog-to-Digital Telemetry System.  

Science.gov (United States)

The Bureau of Mines designed and tested a hardware-software system for measuring on-line corrosion rates of materials in a rod mill in operation. Currents ranging from 10 to the power of -6 to 10 to the power of -3 A and potentials in 1-mV increments were...

P. J. McDonough A. E. Isaacson J. H. Maysilles

1988-01-01

139

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

Energy Technology Data Exchange (ETDEWEB)

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.

Chandler, G.I.; Forman, P.R.; Jahoda, F.C.

1985-01-01

140

Measurement of glucose consumption by hybridoma cells growing in hollow fiber cartridge bioreactors: use of blood glucose self-monitoring devices.  

UK PubMed Central (United Kingdom)

Two different types of blood glucose self-monitoring device, designed for use by diabetics (Accu-Chek Advantage* and Accu-Chek III*), were evaluated for the purpose of monitoring glucose concentration in tissue culture media. The Accu-Chek Advantage* meter was found to systematically overestimate the glucose concentration in a variety of commonly used tissue culture media by 50-90%, in comparison with their formulated glucose concentration. The Accu-Chek III* meter reliably estimated glucose concentrations from 100 to 300 mg/dl and overestimated glucose concentrations above 300 mg/dl. The systematic overestimation of glucose concentration in tissue culture fluids by the Accu-Chek Advantage* meter was further investigated. A standard curve was constructed and the meter reading was found to be linearly related to the actual glucose concentration and the best linear fit was given by the formula y = -43.504 + 1.9246x, where y is the meter reading and x is the actual glucose concentration. Rearranging the equation to make x the subject gave the following algorithm x = (y + 43.504) divided by 1.9246 which could be used to correct the 'raw' meter reading. The mean corrected glucose concentrations deviated from the formulated glucose concentration by less than 3.5% in five media tested, indicating that this meter is more than adequate for monitoring glucose consumption by cells growing in hollow fiber cartridge bioreactors, when used in conjunction with this correction factor.

Nayak RC; Herman IM

1997-07-01

 
 
 
 
141

Measurement of glucose consumption by hybridoma cells growing in hollow fiber cartridge bioreactors: use of blood glucose self-monitoring devices.  

Science.gov (United States)

Two different types of blood glucose self-monitoring device, designed for use by diabetics (Accu-Chek Advantage* and Accu-Chek III*), were evaluated for the purpose of monitoring glucose concentration in tissue culture media. The Accu-Chek Advantage* meter was found to systematically overestimate the glucose concentration in a variety of commonly used tissue culture media by 50-90%, in comparison with their formulated glucose concentration. The Accu-Chek III* meter reliably estimated glucose concentrations from 100 to 300 mg/dl and overestimated glucose concentrations above 300 mg/dl. The systematic overestimation of glucose concentration in tissue culture fluids by the Accu-Chek Advantage* meter was further investigated. A standard curve was constructed and the meter reading was found to be linearly related to the actual glucose concentration and the best linear fit was given by the formula y = -43.504 + 1.9246x, where y is the meter reading and x is the actual glucose concentration. Rearranging the equation to make x the subject gave the following algorithm x = (y + 43.504) divided by 1.9246 which could be used to correct the 'raw' meter reading. The mean corrected glucose concentrations deviated from the formulated glucose concentration by less than 3.5% in five media tested, indicating that this meter is more than adequate for monitoring glucose consumption by cells growing in hollow fiber cartridge bioreactors, when used in conjunction with this correction factor. PMID:9294591

Nayak, R C; Herman, I M

1997-07-14

142

A Pain-free Lancet with a Small Needle for Glucose Measurement.  

Science.gov (United States)

A new lancet with an extremely small needle (0.15 mm diameter and 0.75 mm length) mounted on a small pedestal was tested in diabetic patients for blood glucose measurement in a randomized clinical study. A total of 37 diabetic patients were enrolled for the study. A pain scale categorized from 0 to 3 was created to measure the intensity of puncture pain which was explained to patients before testing. The patients' fingers were punctured with their own old style lancets at least 1 hour before the punctures by the new lancets, and puncture pains recorded according to the pain scale. All patients tested with the new lancet reported no pain and recorded the puncture pain as scale 0. Among the total 37 patients tested with their old style lancets, 2 patients (5.40%) reported no pain and recorded the pain as scale 0, thirteen patients (35.14%) recorded as scale 1, 16 patients (43.24%) as scale 2, and 6 patients (16.22%) as scale 3. The average pain scale of the patients who used old style lancets was 1.702 with the standard error 0.133. The chi-square goodness-of-fit test shows that the proportion of the pain scales comes from the claimed distribution with unequal frequencies, and chi-square tests for independence indicate that neither sex nor age of the sample patients is related to the pain scales.The paired t-test to test the existence of any difference in pain levels between the new lancet and the old style lancet showed; t = 1.702/0.133 = 12.796 with p-value < 0.005 (df = 36). The average pain level from the old style lancet is significantly higher than from the new lancets. Pain-free needle puncture was achieved by limiting the puncture depth to less than 0.75 mm with a thin needle with a 0.15 mm diameter. By allowing patients to see the new lancets before testing, psychological pain anticipation was minimized as the very thin and short needle is visually less intimidating. With a pain free puncture, better compliance and improved subsequent glucose levels may be achieved. PMID:22879781

Kim, Stanley

2010-01-28

143

A Pain-free Lancet with a Small Needle for Glucose Measurement.  

UK PubMed Central (United Kingdom)

A new lancet with an extremely small needle (0.15 mm diameter and 0.75 mm length) mounted on a small pedestal was tested in diabetic patients for blood glucose measurement in a randomized clinical study. A total of 37 diabetic patients were enrolled for the study. A pain scale categorized from 0 to 3 was created to measure the intensity of puncture pain which was explained to patients before testing. The patients' fingers were punctured with their own old style lancets at least 1 hour before the punctures by the new lancets, and puncture pains recorded according to the pain scale. All patients tested with the new lancet reported no pain and recorded the puncture pain as scale 0. Among the total 37 patients tested with their old style lancets, 2 patients (5.40%) reported no pain and recorded the pain as scale 0, thirteen patients (35.14%) recorded as scale 1, 16 patients (43.24%) as scale 2, and 6 patients (16.22%) as scale 3. The average pain scale of the patients who used old style lancets was 1.702 with the standard error 0.133. The chi-square goodness-of-fit test shows that the proportion of the pain scales comes from the claimed distribution with unequal frequencies, and chi-square tests for independence indicate that neither sex nor age of the sample patients is related to the pain scales.The paired t-test to test the existence of any difference in pain levels between the new lancet and the old style lancet showed; t = 1.702/0.133 = 12.796 with p-value < 0.005 (df = 36). The average pain level from the old style lancet is significantly higher than from the new lancets. Pain-free needle puncture was achieved by limiting the puncture depth to less than 0.75 mm with a thin needle with a 0.15 mm diameter. By allowing patients to see the new lancets before testing, psychological pain anticipation was minimized as the very thin and short needle is visually less intimidating. With a pain free puncture, better compliance and improved subsequent glucose levels may be achieved.

Kim S

2010-01-01

144

The relationship between HbA(1c) and fasting plasma glucose in patients with increased plasma liver enzyme measurements  

DEFF Research Database (Denmark)

Background:? HbA(1c) is currently being introduced for diagnostic purpose in diabetes. Previous studies have, however, indicated that patients with liver disease have false low HbA(1c) levels. We therefore investigated the correlation between HbA(1c) and plasma glucose in patients with different levels of increased liver enzyme concentrations. Methods:? Data from 10?065 patients with simultaneous measurement of HbA(1c) , venous fasting plasma glucose, alanine aminotransferase and ?-glutamyl transferase were extracted from our laboratory database. Correlations were investigated in four patient groups divided according to their liver enzyme concentrations. Results:? The correlation between HbA(1c) and plasma glucose was high in all groups, with r?=?0.77 for men and r?=?0.78 for women (P?

Christiansen, R; Rasmussen, L Melholt

2012-01-01

145

Diabetes mellitus modeling and short-term prediction based on blood glucose measurements.  

Science.gov (United States)

Insulin-Dependent Diabetes Mellitus (IDDM) is a chronic disease characterized by the inability of the pancreas to produce sufficient amounts of insulin. Daily compensation of the deficiency requires 4-6 insulin injections to be taken daily, the aim of this insulin therapy being to maintain normoglycemia - i.e., a blood glucose level between 4 and 7mmol/l. To determine the quantity and timing of these injections, various different approaches are used. Currently, mostly qualitative and semi-quantitative models and reasoning are used to design such a therapy. Here, an attempt is made to show how system identification and control may be used to estimate predictive quantitative models to be used in design of optimal insulin regimens. The system was divided into three subsystems, the insulin subsystem, the glucose subsystem and the insulin-glucose interaction. The insulin subsystem aims to describe the absorption of injected insulin from the subcutaneous depots and the glucose subsystem the absorption of glucose from the gut following a meal. These subsystems were modeled using compartment models and proposed models found in the literature. Several black-box models and grey-box models describing the insulin/glucose interaction were developed and analyzed. These models were fitted to real data monitored by an IDDM patient. Many difficulties were encountered, typical of biomedical systems: Non-uniform and scarce sampling, time-varying dynamics and severe nonlinearities were some of the difficulties encountered during the modeling. None of the proposed models were able to describe the system accurately in all aspects during all conditions. However, all the linear models shared some dynamics. Based on the estimated models, short-term blood glucose predictors for up to two-hour-ahead blood glucose prediction were designed. Furthermore, we explored the issues that arise when applying prediction theory and control to short-term blood glucose prediction. PMID:19022264

Ståhl, F; Johansson, R

2008-10-30

146

Diabetes mellitus modeling and short-term prediction based on blood glucose measurements.  

UK PubMed Central (United Kingdom)

Insulin-Dependent Diabetes Mellitus (IDDM) is a chronic disease characterized by the inability of the pancreas to produce sufficient amounts of insulin. Daily compensation of the deficiency requires 4-6 insulin injections to be taken daily, the aim of this insulin therapy being to maintain normoglycemia - i.e., a blood glucose level between 4 and 7mmol/l. To determine the quantity and timing of these injections, various different approaches are used. Currently, mostly qualitative and semi-quantitative models and reasoning are used to design such a therapy. Here, an attempt is made to show how system identification and control may be used to estimate predictive quantitative models to be used in design of optimal insulin regimens. The system was divided into three subsystems, the insulin subsystem, the glucose subsystem and the insulin-glucose interaction. The insulin subsystem aims to describe the absorption of injected insulin from the subcutaneous depots and the glucose subsystem the absorption of glucose from the gut following a meal. These subsystems were modeled using compartment models and proposed models found in the literature. Several black-box models and grey-box models describing the insulin/glucose interaction were developed and analyzed. These models were fitted to real data monitored by an IDDM patient. Many difficulties were encountered, typical of biomedical systems: Non-uniform and scarce sampling, time-varying dynamics and severe nonlinearities were some of the difficulties encountered during the modeling. None of the proposed models were able to describe the system accurately in all aspects during all conditions. However, all the linear models shared some dynamics. Based on the estimated models, short-term blood glucose predictors for up to two-hour-ahead blood glucose prediction were designed. Furthermore, we explored the issues that arise when applying prediction theory and control to short-term blood glucose prediction.

Ståhl F; Johansson R

2009-02-01

147

Longitudinal effects of MRI-measured hepatic steatosis on biomarkers of glucose homeostasis and hepatic apoptosis in obese youth.  

UK PubMed Central (United Kingdom)

OBJECTIVE: We used fast-gradient magnetic resonance imaging (MRI) to determine the longitudinal associations between the hepatic fat content (HFF), glucose homeostasis, and a biomarker of hepatocellular apoptosis in obese youth. RESEARCH DESIGN AND METHODS: Baseline and longitudinal liver and abdominal MRI were performed with an oral glucose tolerance test in 76 obese youth followed for an average of 1.9 years. Cytokeratin-18 (CK-18) was measured at baseline and follow-up as a biomarker of hepatic apoptosis. The relationship between baseline HFF and metabolic parameters and circulating levels of CK-18 at follow-up were assessed using a bivariate correlation. RESULTS: At baseline, 38% had hepatic steatosis based on %HFF ?5.5% with alterations in indices of insulin sensitivity and secretion. At follow-up, BMI increased in both groups and baseline %HFF correlated strongly with the follow-up %HFF (r = 0.81, P < 0.001). Over time, markers of insulin sensitivity and 2-h glucose improved significantly in the group without fatty liver, in contrast with the persistence of the insulin resistance and associated correlates in the fatty liver group. Baseline HFF correlated with 2-h glucose (r = 0.38, P = 0.001), whole-body insulin sensitivity (r = -0.405, P = 0.001), adiponectin (r = -0.44, P < 0.001), CK-18 levels, (r = 0.63, P < 0.001), and disposition index (r = -0.272, P = 0.021) at follow-up. In a multivariate analysis, we showed that baseline HFF is an independent predictor of 2-h glucose and whole-body insulin sensitivity. CONCLUSIONS: In obese youth, the phenotype of MRI-measured hepatic steatosis is persistent. Baseline HFF strongly modulates longitudinally 2-h blood glucose, biomarkers of insulin resistance, and hepatocellular apoptosis.

Kim G; Giannini C; Pierpont B; Feldstein AE; Santoro N; Kursawe R; Shaw M; Duran E; Goldberg R; Dziura J; Caprio S

2013-01-01

148

Experimentally Measured Interfacial Area during Gas Injection into Saturated Porous Media: An Air Sparging Analogy  

Energy Technology Data Exchange (ETDEWEB)

The amount of interfacial area (awn) between air and subsurface liquids during air-sparging can limit the rate of site remediation. Lateral movement within porous media could be encountered during air-sparging operations when air moves along the bottom of a low-permeability lens. This study was conducted to directly measure the amount of awn between air and water flowing within a bench-scale porous flow cell during the lateral movement of air along the upper edge of the cell during air injections into an initially water-saturated flow cell. Four different cell orientations were used to evaluate the effect of air injection rates and porous media geometries on the amount of awn between fluids. Air was injected at flow rates that varied by three orders of magnitude, and for each flow cellover this range of injection rates little change in awn was noted. A wider variation in awn was observed when air moved through different regions for the different flow cell orientations. These results are in good agreement with the experimental findings of Waduge et al. (2007), who performed experiments in a larger sand-pack flow cell, and determined that air-sparging efficiency is nearly independent of flow rate but highly dependent on the porous structure. By directly measuring the awn, and showing that awn does not vary greatly with changes in injection rate, we show that the lack of improvement to remediation rates is because there is a weak dependence of the awn on the air injection rate.

Crandall, Dustin; Ahmadi, Goodarz; Smith, Duane H., Bromhal, Grant

2010-01-01

149

Analog multivariate counting analyzers  

CERN Multimedia

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...

Nikitin, A V; Armstrong, T P

2003-01-01

150

Tetrachlorofluorescein TInsP as a Substrate Analog Probe for Measuring Phytase Activity in Surface Water: Proof of Concept.  

Science.gov (United States)

An innovative approach for measuring phytase activity (PA) in surface water is presented. A substrate analog of -inositol hexakis(dihydrogen) phosphate (InsP), commonly referred to as phytic acid, 1--5--(1-oxo-1-(2' ,4,7,7' -tetrachloro-3',6'-dihydroxy-3-oxo-3H-spiro[isobenzofuran-1,9'-xanthen]-6-yl)-5,8,11-trioxa-2-azatridecan-13-yl)-inositol 1,2,3,4,6-pentakis--(dihydrogen) phosphate, referred to as tetrachlorofluorescein (TET) tethered (T)InsP, has been developed that can be used to monitor the (phytase-catalyzed) phosphate ester bond-cleavage reaction. Test phytases, (wheat [4-] and [3-] phytase) sequentially remove phosphate groups from TET TInsP, producing dephosphorylated probe species that were readily separated by reversed-phase high-performance liquid chromatography (RP-HPLC). Because dephosphorylated probe species retain the TET group, highly sensitive quantification could be achieved using fluorescence detection (excitation/emission ' = 245/540 nm). Calibration curves for TET TInsP, which could be used as a standard for quantifying all probe species, were linear ( > 0.999) over the range of concentrations tested. Phytase-generated dephosphorylated probe species were characterized or identified using RP-HPLC with mass spectrometry. Results of mass spectrometry analysis show that the RP-HPLC system was capable of distinguishing between dephosphorylated probe species at the regioisomeric level. The TET TInsP molecular probe was used to successfully measure PA in pond water. We found that the PA associated with the particulate plus water-soluble fraction was greater than that observed for the water-soluble fraction alone. Moreover, it appeared that 4- and 3-phytase were active in pond water based on an analysis of the chromatographic profile (i.e., elution sequence) of dephosphorylated probe species produced. The advent of a fluorescent substrate analog of InsP affords environmental scientists with the means to unambiguously quantify an extremely small amount of phytase-generated dephosphorylated product(s), enabling the measurement of PA over a reasonably short time duration, in an environmental sample containing low concentrations of enzyme. PMID:23673739

Berry, Duane F; Harich, Kim

151

Tetrachlorofluorescein TInsP as a Substrate Analog Probe for Measuring Phytase Activity in Surface Water: Proof of Concept.  

UK PubMed Central (United Kingdom)

An innovative approach for measuring phytase activity (PA) in surface water is presented. A substrate analog of -inositol hexakis(dihydrogen) phosphate (InsP), commonly referred to as phytic acid, 1--5--(1-oxo-1-(2' ,4,7,7' -tetrachloro-3',6'-dihydroxy-3-oxo-3H-spiro[isobenzofuran-1,9'-xanthen]-6-yl)-5,8,11-trioxa-2-azatridecan-13-yl)-inositol 1,2,3,4,6-pentakis--(dihydrogen) phosphate, referred to as tetrachlorofluorescein (TET) tethered (T)InsP, has been developed that can be used to monitor the (phytase-catalyzed) phosphate ester bond-cleavage reaction. Test phytases, (wheat [4-] and [3-] phytase) sequentially remove phosphate groups from TET TInsP, producing dephosphorylated probe species that were readily separated by reversed-phase high-performance liquid chromatography (RP-HPLC). Because dephosphorylated probe species retain the TET group, highly sensitive quantification could be achieved using fluorescence detection (excitation/emission ' = 245/540 nm). Calibration curves for TET TInsP, which could be used as a standard for quantifying all probe species, were linear ( > 0.999) over the range of concentrations tested. Phytase-generated dephosphorylated probe species were characterized or identified using RP-HPLC with mass spectrometry. Results of mass spectrometry analysis show that the RP-HPLC system was capable of distinguishing between dephosphorylated probe species at the regioisomeric level. The TET TInsP molecular probe was used to successfully measure PA in pond water. We found that the PA associated with the particulate plus water-soluble fraction was greater than that observed for the water-soluble fraction alone. Moreover, it appeared that 4- and 3-phytase were active in pond water based on an analysis of the chromatographic profile (i.e., elution sequence) of dephosphorylated probe species produced. The advent of a fluorescent substrate analog of InsP affords environmental scientists with the means to unambiguously quantify an extremely small amount of phytase-generated dephosphorylated product(s), enabling the measurement of PA over a reasonably short time duration, in an environmental sample containing low concentrations of enzyme.

Berry DF; Harich K

2013-01-01

152

Analogical Representations  

UK PubMed Central (United Kingdom)

Maps and pictures are examples of analogical representations. The internal structureof such representations closely resembles the internal structure of the things represented.Such representations have good computational properties, and have been used successfullyin various knowledge-based reasoning systems. In this paper, we review the propertiesand uses of such representations.1 IntroductionThe notion of analogical representations or analogues was introduced by Sloman (1971) inorder to make a distinction between representations consisting of a description in some language,and representations which are more direct models or pictures of the things represented.Sloman uses the term Fregean representations for the first category, and analogical representationsfor the latter. An example of a Fregean representation is a set of sentences in first-orderlogic. Some examples of analogical representations are maps, pictures, diagrams, linked lists,and flow charts. In recent year...

Bart Selman

153

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

1986-01-01

154

Direct chemical measurement of the lambda of the lumped constant of the [14C]deoxyglucose method in rat brain: effects of arterial plasma glucose level on the distribution spaces of [14C]deoxyglucose and glucose and on lambda.  

UK PubMed Central (United Kingdom)

The lumped constant in the operational equation of the 2-[14C]deoxyglucose (DG) method contains the factor lambda that represents the ratio of the steady-state tissue distribution spaces for [14C]DG and glucose. The lumped constant has been shown to vary with arterial plasma glucose concentration. Predictions based mainly on theoretical grounds have suggested that disproportionate changes in the distribution spaces for [14C]DG and glucose and in the value of lambda are responsible for these variations in the lumped constant. The influence of arterial plasma glucose concentration on the distribution spaces for DG and glucose and on lambda were, therefore, determined in the present studies by direct chemical measurements. The brain was maintained in steady states of delivery and metabolism of DG and glucose by programmed intravenous infusions of both hexoses designed to produce and maintain constant arterial concentrations. Hexose concentrations were assayed in acid extracts of arterial plasma and freeze-blown brain. Graded hyperglycemia up to 28 mM produced progressive decreases in the distribution spaces of both hexoses from their normoglycemic values (e.g., approximately -20% for glucose and -50% for DG at 28 mM). In contrast, graded hypoglycemia progressively reduced the distribution space for glucose and increased the space for [14C]DG. The values for lambda were comparatively stable in normoglycemic and hyperglycemic conditions but rose sharply (e.g., as much as 9-10-fold at 2 mM) in severe hypoglycemia.

Mori K; Cruz N; Dienel G; Nelson T; Sokoloff L

1989-06-01

155

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)

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.

Laleh Payahoo; Alireza Ostadrahimi; Majid Mobasseri; Yaser Khaje Bishak; Nazila Farrin; Mohammad Asghari Jafarabadi; Sepide Mahluji

2013-01-01

156

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

2010-01-01

157

A self referencing platinum nanoparticle decorated enzyme-based microbiosensor for real time measurement of physiological glucose transport.  

Science.gov (United States)

Glucose is the central molecule in many biochemical pathways, and numerous approaches have been developed for fabricating micro biosensors designed to measure glucose concentration in/near cells and/or tissues. An inherent problem for microsensors used in physiological studies is a low signal-to-noise ratio, which is further complicated by concentration drift due to the metabolic activity of cells. A microsensor technique designed to filter extraneous electrical noise and provide direct quantification of active membrane transport is known as self-referencing. Self-referencing involves oscillation of a single microsensor via computer-controlled stepper motors within a stable gradient formed near cells/tissues (i.e., within the concentration boundary layer). The non-invasive technique provides direct measurement of trans-membrane (or trans-tissue) analyte flux. A glucose micro biosensor was fabricated using deposition of nanomaterials (platinum black, multiwalled carbon nanotubes, Nafion) and glucose oxidase on a platinum/iridium microelectrode. The highly sensitive/selective biosensor was used in the self-referencing modality for cell/tissue physiological transport studies. Detailed analysis of signal drift/noise filtering via phase sensitive detection (including a post-measurement analytical technique) are provided. Using this highly sensitive technique, physiological glucose uptake is demonstrated in a wide range of metabolic and pharmacological studies. Use of this technique is demonstrated for cancer cell physiology, bioenergetics, diabetes, and microbial biofilm physiology. This robust and versatile biosensor technique will provide much insight into biological transport in biomedical, environmental, and agricultural research applications. PMID:20965716

McLamore, E S; Shi, J; Jaroch, D; Claussen, J C; Uchida, A; Jiang, Y; Zhang, W; Donkin, S S; Banks, M K; Buhman, K K; Teegarden, D; Rickus, J L; Porterfield, D M

2010-09-29

158

Measurements of glucose metabolism in single equine embryos during early development.  

UK PubMed Central (United Kingdom)

The contributions of 2 biochemical pathways to the total metabolism of glucose (the Embden-Meyerhof pathway [EMP] and the pentose phosphate pathway [PPP]), were assessed for equine embryos recovered on Day 4.5, 7.5 and 11.5 post ovulation. At all developmental stages studied, glucose was metabolized through both pathways. Through the EMP, the amounts of glucose metabolized per nl embryo volume per hour were 4.0, 9.9 and 3.1 pmol, whereas via the PPP, amounts were 0.9, 1.7 and 0.07 pmol for Day-4.5, -7.5 and -11.5 embryos, respectively. The ratio of EMP:PPP with age was 9.7 for Day -4.5 embryos, 7.6 for Day-7.5 embryos and 90.2 for Day -11.5 embryos. Two of the 6 unfertilized ova (UFO) exhibited metabolism through both pathways.

Brück I; Hyland JH

1991-01-01

159

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

Energy Technology Data Exchange (ETDEWEB)

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.

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

1985-05-01

160

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

International Nuclear Information System (INIS)

[en] 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

1985-01-01

 
 
 
 
161

Glucose variability.  

UK PubMed Central (United Kingdom)

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

Service FJ

2013-05-01

162

Evaluation of Point-of-Care Blood Glucose Measurements in Patients with Diabetic Ketoacidosis or Hyperglycemic Hyperosmolar Syndrome Admitted to a Critical Care Unit.  

UK PubMed Central (United Kingdom)

BACKGROUND: Point-of-care (POC) blood glucose (BG) measurement is currently not recommended in the treatment of patients presenting with diabetic ketoacidosis (DKA) or hyperglycemic hyperosmolar syndrome (HHS). METHODS: We prospectively evaluated and compared capillary and venous POC BG values with laboratory venous glucose in patients with DKA or HHS admitted to one critical care unit over 8 months. RESULTS: Venous laboratory glucose was strongly correlated with venous (r = 0.98) and capillary (r = 0.96) POC glucose values, though POC glucose values were higher than venous laboratory values (venous POC 21 ± 3 mg/dl, capillary POC 30 ± 4 mg/dl; both p < .001). Increased plasma osmolality had no effect on glucose meter error, while acidemia (pH < 7.3) was associated with greater glucose meter error (p = .04) independent of glucose levels. Comparing hypothetical insulin infusion rates based on laboratory venous glucose to actual infusion rates based on POC glucose values showed that 33/61 insulin infusion rates would have been unchanged, while 28 out of 61 rates were on average 7% ± 2% higher. There were no instances of hypoglycemia in any of the patients. CONCLUSIONS: Overall, both venous and capillary POC BG values were safe for the purpose of titrating insulin infusions in patients with severe hyperglycemia. Acidemia, but not hyperosmolality, increased POC BG value errors.

Corl DE; Yin TS; Mills ME; Spencer TL; Greenfield L; Beauchemin E; Cochran J; Suhr LD; Thompson RE; Wisse BE

2013-01-01

163

The importance of glucose metabolism in the hypoxic cytotoxicity of Misonidazole  

International Nuclear Information System (INIS)

The authors are investigating the mechanism of inhibition of glucose metabolism and its role in the hypoxic cytotoxicity of Misonidazole (Miso). Preincubation of hypoxic exponential EMT6/Ro cells with Miso and 5.5 mM glucose containing media caused a time-dependent inhibition of both glucose consumption and lactate formation. This inhibition began after 90 min, 45 min, and 15 min preincubation with 1mM, 2.5mM, and 5mM Miso respectively. The inhibition closely correlated with the kinetics and extent of decreased viability of these cells as measured by dye exclusion and colony forming efficiency. Miso does not inhibit glucose transport in these phloretin-sensitive cells. Transport was measured by the uptake of 3-0-methyl-D-glucose, a non-metabolized glucose analog. The initial rate was determined to be the same (1.66 +- 0.18 nmoles cell/second at 250C)

1985-01-01

164

Use of arterialised venous instead of arterial blood for measurement of myocardial glucose metabolism during euglycaemic-hyperinsulinaemic clamping  

International Nuclear Information System (INIS)

[en] Sampling of arterialised venous blood (AVB) is often used as an alternative to sampling of arterial blood when determining the myocardial metabolic rate of glucose (MRGlu). This method, however, has not yet been validated for measurement of plasma fluorine-18 fluorodeoxyglucose (FDG) activity during a euglycaemic-hyperinsulinaemic clamp (EHC). In this study, dynamic FDG scans were performed with arterial blood sampling during EHC. Samples of arterial and AVB or venous blood were simultaneously withdrawn at five time points for measurement of FDG activity and plasma glucose in 36 patients. Both venous to arterial and AVB to arterial ratios were calculated for FDG activity and plasma glucose. Mean ratios between AVB and arterial FDG activity were then used to create calculated arterialised venous input functions from corresponding arterial input functions. The mean effect of arterialisation on the calculation of Ki was assessed. In nine additional patients, Ki obtained with continuous sampling of AVB was compared with Ki obtained with a corresponding (quality-controlled) image-derived input function from the ascending aorta. Using AVB, measurements of FDG activity were much more reliable than with venous blood sampling. As compared with arterial sampling, however, FDG activity was underestimated early after injection, while it was overestimated after 20 min. In both analyses, AVB resulted in 10%±10% overestimation of Ki. Because of a 5%±5% underestimation of plasma glucose concentration with AVB, the net effect on the final calculation of MRGlu was small (on average 5% overestimation). It is concluded that the use of AVB has a small average effect on the determination of MRGlu. This method does, however, contribute to variability in the results. This variability cannot be explained by different degrees of arterialisation. (orig.)

2002-01-01

165

Measurement of pharmacokinetics of yttrium-86 radiopharmaceuticals with PET and radiation dose calculation of analogous yttrium-90 radiotherapeutics.  

UK PubMed Central (United Kingdom)

This study was performed to demonstrate the quantitative in vivo assessment of human pharmacokinetics of 90Y-radiotherapeutics using the positron-emitting substitute 86Y and PET. This technique is illustrated in a patient with disseminated bone metastases from breast cancer who was injected with 100 MBq of 86Y-citrate as an analog of the commercially available radiotherapeutic 90Y-citrate. Whole-body distribution was measured with a PET camera 4, 10, 21, 28 and 45 hr postinjection. Uptake data were determined from reconstructed transverse PET images by regions of interest placed in normal bone tissue, liver and metastases. Images of coronal and sagittal whole-body sections were obtained by reformatting the transverse PET images. The ratio of activity concentration in metastases to that in normal bone ranged from 1.5:1 to 3.5:1. Of the injected tracer, 13.4% was found in the skeleton and 0.43% in the metastasis with the highest 86Y concentration. Radiation doses per 1 MBq of injected 90Y-citrate were calculated from 86Y-citrate data and data from MIRD pamphlets 5 and 11. The doses were 1.01 MGy/MBq for red marrow, 593 microGy/MBq for the liver and approximately 3.5 MGy/MBq for the most conspicuous metastases. This study demonstrates that the use of PET via 86Y allows an individual in vivo quantification of activity uptake and radiation dose of both normal tissue and tumor in pain treatment with 90Y-labeled radiotherapeutics.

Herzog H; Rösch F; Stöcklin G; Lueders C; Qaim SM; Feinendegen LE

1993-12-01

166

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  

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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 m...

Gama MP; Cruzeta CF; Ossowski AC; Bay MR; Michaelis MM; Camacho SL

167

Direct chemical measurement of the lambda of the lumped constant of the [14C]deoxyglucose method in rat brain: effects of arterial plasma glucose level on the distribution spaces of [14C]deoxyglucose and glucose and on lambda.  

Science.gov (United States)

The lumped constant in the operational equation of the 2-[14C]deoxyglucose (DG) method contains the factor lambda that represents the ratio of the steady-state tissue distribution spaces for [14C]DG and glucose. The lumped constant has been shown to vary with arterial plasma glucose concentration. Predictions based mainly on theoretical grounds have suggested that disproportionate changes in the distribution spaces for [14C]DG and glucose and in the value of lambda are responsible for these variations in the lumped constant. The influence of arterial plasma glucose concentration on the distribution spaces for DG and glucose and on lambda were, therefore, determined in the present studies by direct chemical measurements. The brain was maintained in steady states of delivery and metabolism of DG and glucose by programmed intravenous infusions of both hexoses designed to produce and maintain constant arterial concentrations. Hexose concentrations were assayed in acid extracts of arterial plasma and freeze-blown brain. Graded hyperglycemia up to 28 mM produced progressive decreases in the distribution spaces of both hexoses from their normoglycemic values (e.g., approximately -20% for glucose and -50% for DG at 28 mM). In contrast, graded hypoglycemia progressively reduced the distribution space for glucose and increased the space for [14C]DG. The values for lambda were comparatively stable in normoglycemic and hyperglycemic conditions but rose sharply (e.g., as much as 9-10-fold at 2 mM) in severe hypoglycemia. PMID:2715202

Mori, K; Cruz, N; Dienel, G; Nelson, T; Sokoloff, L

1989-06-01

168

Developmental expression of the glucose transporter in brain microvessels  

International Nuclear Information System (INIS)

[en] 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

1990-02-26

169

GLP-1 and insulin analogs  

Directory of Open Access Journals (Sweden)

Full Text Available Insulin analogs are produced by synthetically modifying the human insulin molecule, retaining the glucose regulatory function of native insulin with different absorption and activity characteristics. Glucagon-like peptide-1 (GLP-1) analogs mimic the action of the peptide hormone GLP-1, and have a glucose-dependent action on the insulin/glucagon balance. This treatment review focuses on five recent publications that compare both GLP-1 and insulin analogs with established treatment regimens. Two publications compared once-daily liraglutide with twice-daily exenatide and investigated a switch from basal neutral protamine Hagedorn (NPH)-insulin to glargine or detemir in type 1 diabetes patients. A meta-analysis assessed differences in glycemic control, hypoglycemia, and weight gain between treatment with NPH-insulin and insulin detemir or glargine in type 1 diabetes patients. Two further studies investigated whether hormonal and symptomatic responses during hypoglycemia were altered with detemir in comparison with human or NPH insulin. The review concludes that switching to long-acting insulin analogs from NPH or human insulin appears to be associated with an improvement in glycemic control, and a lower risk of nocturnal and severe hypoglycemia. The switch does not appear to alter counter-regulatory hormonal responses during hypoglycemia in the studies reviewed, although it remains unclear whether symptoms of hypoglycemia differ between insulin types.

Nicole Meinel

2010-01-01

170

Effect of postprandial hyperglycaemia in non-invasive measurement of cerebral metabolic rate of glucose in non-diabetic subjects  

Energy Technology Data Exchange (ETDEWEB)

The aim of this study was to determine the effect of postprandial hyperglycaemia (HG) on the non-invasive measurement of cerebral metabolic rate of glucose (CMRGlc). Five patients who had a meal within an hour before a fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) examination were recruited in this study. They underwent intermittent arterial blood sampling (measured input function), and, based on this sampling, CMRGlc was calculated using an autoradiographic method (CMRGlc{sub real}). Simulated input functions were generated based on standardised input function, body surface area and net injected dose of FDG, and simulated CMRGlc (CMRGlc{sub sim}) was also calculated. Percent error of the area under the curve (AUC) between measured (AUC{sub real}) and simulated input function (AUC{sub IFsim}) and percent error between CMRGlc{sub real} and CMRGlc{sub sim} were calculated. These values were compared with those obtained from a previous study conducted under fasting conditions (F). The serum glucose level in the HG group was significantly higher than that in the F group (165{+-}69 vs 100{+-}9 mg/dl, P=0.0007). Percent errors of AUC and CMRGlc in grey matter and white matter in HG were significantly higher than those in F (12.9%{+-}1.3% vs 3.5%{+-}2.2% in AUC, P=0.0015; 18.2%{+-}2.2% vs 2.9%{+-}1.9% in CMRGlc in grey matter, P=0.0028; 24.0%{+-}4.6% vs 3.4%{+-}2.2% in CMRGlc in white matter, P=0.0028). It is concluded that a non-invasive method of measuring CMRGlc should be applied only in non-diabetic subjects under fasting conditions. (orig.)

Tsuchida, Tatsuro; Itoh, Harumi [Department of Radiology, Fukui Medical University, Matsuoka (Japan); Sadato, Norihiro; Nishizawa, Sadahiko; Yonekura, Yoshiharu [Biomedical Imaging Research Center, Fukui Medical University (Japan)

2002-02-01

171

Chemerin analog regulates energy metabolism in sheep.  

UK PubMed Central (United Kingdom)

Accumulating data suggest a relationship between chemerin and energy metabolism. Our group previously described gene cloning, expression analysis and the regulatory mechanism of chemerin and its own receptor in mice and cattle. The objective of the present study was to investigate the physiological effect of chemerin on endocrine changes and energy metabolism in sheep using a biologically stable chemerin analog. The chemerin analog was intravenously administrated (100 or 500?µg/head) to sheep, and plasma insulin and metabolites (glucose, nonesterified fatty acids (NEFA), triglyceride, total cholesterol and high-density lipoprotein (HDL) cholesterol) were analyzed. The chemerin analog dramatically increased the insulin levels, and glucose levels were decreased. NEFA levels were slightly decreased at 20?min but then increased gradually from 60 to 180?min after analog administration. In addition, injection of the chemerin analog immediately increased triglyceride and total cholesterol but not HDL levels. These results suggested that chemerin analog regulated insulin secretion related to glucose metabolism and the release of triglycerides in sheep in vivo. This study provides new information about endocrine and metabolic changes in response to chemerin in sheep.

Suzuki Y; Song SH; Sato K; So KH; Ardiyanti A; Kitayama S; Hong YH; Lee SD; Choi KC; Hagino A; Katoh K; Roh SG

2012-03-01

172

Chemerin analog regulates energy metabolism in sheep.  

Science.gov (United States)

Accumulating data suggest a relationship between chemerin and energy metabolism. Our group previously described gene cloning, expression analysis and the regulatory mechanism of chemerin and its own receptor in mice and cattle. The objective of the present study was to investigate the physiological effect of chemerin on endocrine changes and energy metabolism in sheep using a biologically stable chemerin analog. The chemerin analog was intravenously administrated (100 or 500?µg/head) to sheep, and plasma insulin and metabolites (glucose, nonesterified fatty acids (NEFA), triglyceride, total cholesterol and high-density lipoprotein (HDL) cholesterol) were analyzed. The chemerin analog dramatically increased the insulin levels, and glucose levels were decreased. NEFA levels were slightly decreased at 20?min but then increased gradually from 60 to 180?min after analog administration. In addition, injection of the chemerin analog immediately increased triglyceride and total cholesterol but not HDL levels. These results suggested that chemerin analog regulated insulin secretion related to glucose metabolism and the release of triglycerides in sheep in vivo. This study provides new information about endocrine and metabolic changes in response to chemerin in sheep. PMID:22435632

Suzuki, Yutaka; Song, Sang-Houn; Sato, Katsuyoshi; So, Kyoung-Ha; Ardiyanti, Astrid; Kitayama, Shun; Hong, Yeon-Hee; Lee, Sung-Dae; Choi, Ki-Choon; Hagino, Akihiko; Katoh, Kazuo; Roh, Sang-gun

2012-02-10

173

Avaliação de dois sensores portáteis para mensuração da glicemia em cães Evaluation of two portable meters for blood glucose measurements in dogs  

Directory of Open Access Journals (Sweden)

Full Text Available Avaliou-se a precisão analítica e clínica de dois sensores portáteis para mensuração da glicemia em cães. Os valores da mensuração da glicemia obtidos com os sensores foram comparados com aqueles obtidos pelo método padrão da glicose oxidase, por meio da análise de correlação e da análise da grade de erros. Os resultados gerados pelos sensores não foram diferentes do método padrão. Conclui-se que ambos os sensores são adequados para mensuração da glicemia em cães.The clinical and analytical accuracy of two portable meters for glucose measurement in dogs was evaluated. Blood glucose values obtained by the use of portable meters were compared to those obtained using the glucose oxidase reference method, by means of correlation and error analysis. Results obtained with the blood glucose meters were not different from those obtained with the reference method. Both apparatus evaluated are adequate for use in dogs.

K. Bluwol; R. Duarte; M.D. Lustoza; D.M.N. Simões; M.M. Kogika

2007-01-01

174

GANGLIOSIDE ANALOGS  

UK PubMed Central (United Kingdom)

Ganglioside lactam analogue derivatives of general formula (I) in which A is a sialic acid residue of formula (II) which is bound via the dashed line in the 2-position; and in which Z1 is -OH or a group -NHX1, and Y30 is -CH3 or -CH2OH; X1 and Y1 together form a bond and Y2 is -OH or a group OR20, or X1 and Y2 together form a bond and Y1 is -OH or -NHAc; Y3 is -OH or a group -OR20; R1 is H or a sialic acid residue of formula (III) which is bound via the dashed line in the 2-position; and in which Z2 is -OH or a group -NHX2, and Y30 is as defined above; X2 and Y10 together form a bond and Y20 is -OH, or X2 and Y20 together form a bond and Y10 is -OH; with the provisos that when R1 is H, then Z1 is -NHX1, and that when R1 is a sialic acid residue of formula (III), then at least one of Z1 and Z2 is different from -OH; R10 is H, a carrier CA, or a group -(Sugar)n. The compounds are hydrolytically stable lactam analogs which spatially closely resemble the naturally occurring ganglioside lactones and are antigenic and able to induce the production of antibodies that cross-react with the corresponding ganglioside lactone.

MAGNUSSON Hans Göran; ASIM Kumar Ray

175

Ganglioside analogs  

UK PubMed Central (United Kingdom)

PCT No. PCT/DK92/00333 Sec. 371 Date Sep. 12, 1994 Sec. 102(e) Date Sep. 12, 1994 PCT Filed Nov. 11, 1992 PCT Pub. No. WO93/10134 PCT Pub. Date May 27, 1993Ganglioside lactam analogue derivatives of general formula (I) in which A is a sialic acid residue of formula (II) which is bound via the dashed line in the 2-position; and in which Z1 is -OH or a group -NHX1, and Y30 is -CH3 or -CH2OH; X1 and Y1 together form a bond and Y2 is -OH or a group OR20, or X1 and Y2 together form a bond and Y1 is -OH or -NHAc; Y3 is -OH or a group -OR20; R1 is H or a sialic acid residue of formula (III) which is bound via the dashed line in the 2-position; and in which Z2 is -OH or a group -NHX2, and Y30 is as defined above; X2 and Y10 together form a bond and Y20 is -OH, or X2 and Y20 together form a bond and Y10 is -OH; with the provisos that when R1 is H, then Z1 is -NHX1, and that when R1 is a sialic acid residue of formula (III), then at least one of Z1 and Z2 is different from -OH; R10 is H, a carrier CA, or a group -(Sugar)n. The compounds are hydrolytically stable lactam analogs which spatially closely resemble the naturally occurring ganglioside lactones and are antigenic and able to induce the production of antibodies that cross-react with the corresponding ganglioside lactone.

MAGNUSSON HANS G; RAY ASIM K

176

Measurement of insulin-mediated glucose uptake: direct comparison of the modified insulin suppression test and the euglycemic, hyperinsulinemic clamp.  

UK PubMed Central (United Kingdom)

BACKGROUND: Two direct measurements of peripheral insulin sensitivity are the M value derived from the euglycemic, hyperinsulinemic clamp (EC) and the steady-state plasma glucose (SSPG) concentration derived from the insulin suppression test (IST). Prior work suggests that these measures are highly correlated, but the agreement between them is unknown. To determine the agreement between SSPG and M and to develop transformation equations to convert SSPG to M and vice versa, we directly compared these two measurements in the same individuals. METHODS: A total of 15 nondiabetic subjects (9 women and 6 men) underwent both an EC and a modified version of the IST within a median interval of 5days. We performed standard correlation metrics of the two measures and developed transformation regression equations for the two measures. RESULTS: The mean±SD age of the subjects was 57±7years and body mass index, 27.7±3.9kg/m(2). The median (interquartile range) SSPG concentration was 6.7 (5.1, 9.8) mmol/L and M value, 49.6 (28.9, 64.2) ?mol/min/kg-LBM. There was a highly significant correlation between SSPG and M (r=-0.87, P <0.001). The relationship was best fit by regression models with exponential/logarithmic functions (R(2)=0.85). Bland-Altman plots demonstrated an excellent agreement between these measures of insulin action. CONCLUSION: The SSPG and M are highly related measures of insulin sensitivity and the results provide the means to directly compare the two measurements.

Knowles JW; Assimes TL; Tsao PS; Natali A; Mari A; Quertermous T; Reaven GM; Abbasi F

2013-04-01

177

CMOS image sensors as an efficient platform for glucose monitoring.  

Science.gov (United States)

Complementary metal oxide semiconductor (CMOS) image sensors have been used previously in the analysis of biological samples. In the present study, a CMOS image sensor was used to monitor the concentration of oxidized mouse plasma glucose (86-322 mg dL(-1)) based on photon count variation. Measurement of the concentration of oxidized glucose was dependent on changes in color intensity; color intensity increased with increasing glucose concentration. The high color density of glucose highly prevented photons from passing through the polydimethylsiloxane (PDMS) chip, which suggests that the photon count was altered by color intensity. Photons were detected by a photodiode in the CMOS image sensor and converted to digital numbers by an analog to digital converter (ADC). Additionally, UV-spectral analysis and time-dependent photon analysis proved the efficiency of the detection system. This simple, effective, and consistent method for glucose measurement shows that CMOS image sensors are efficient devices for monitoring glucose in point-of-care applications. PMID:23900281

Devadhasan, Jasmine Pramila; Kim, Sanghyo; Choi, Cheol Soo

2013-08-27

178

CMOS image sensors as an efficient platform for glucose monitoring.  

UK PubMed Central (United Kingdom)

Complementary metal oxide semiconductor (CMOS) image sensors have been used previously in the analysis of biological samples. In the present study, a CMOS image sensor was used to monitor the concentration of oxidized mouse plasma glucose (86-322 mg dL(-1)) based on photon count variation. Measurement of the concentration of oxidized glucose was dependent on changes in color intensity; color intensity increased with increasing glucose concentration. The high color density of glucose highly prevented photons from passing through the polydimethylsiloxane (PDMS) chip, which suggests that the photon count was altered by color intensity. Photons were detected by a photodiode in the CMOS image sensor and converted to digital numbers by an analog to digital converter (ADC). Additionally, UV-spectral analysis and time-dependent photon analysis proved the efficiency of the detection system. This simple, effective, and consistent method for glucose measurement shows that CMOS image sensors are efficient devices for monitoring glucose in point-of-care applications.

Devadhasan JP; Kim S; Choi CS

2013-08-01

179

Computed NMR shielding increments over benzo-analogs of unsaturated five-membered ring heterocyclic compounds as a measure of aromaticity.  

UK PubMed Central (United Kingdom)

The GIAO-HF method in Gaussian 03 was used to calculate the isotropic shielding value of the proximal hydrogen of a diatomic hydrogen probe moved in a square grid 2.5A above the plane of 15 benzo-fused analogs of conjugated five-membered ring heterocyclic compounds: pyrrole, furan, thiophene, and phosphole and their 2- and 3-nitrogen analogs. Subtraction of the calculated isotropic shielding value of diatomic hydrogen from each of these isotropic shielding values gave the shielding increment (Delta sigma) for each probe position. Plotting this value against Cartesian coordinates of the probe position allowed determination of the computed through-space shielding increment surfaces for these compounds. Substantial shielding was observed above the center of each ring, as expected for aromatic compounds. The magnitude of the shielding increment 2.5A above the heterocyclic ring center correlated reasonably well with the only other published method of assessing aromaticity of these systems ASE (aromatic stabilization energy) and with our calculated NICS (nucleus-independent chemical shift) values, another magnetic criterion. The magnitude of the shielding increment measured over the benzene ring midpoint did not correlate well with other measures of aromaticity, however.

Martin NH; Rowe JE; Pittman EL

2010-04-01

180

The control of glucose concentration during yeast fed-batch cultivation using a fast measurement complemented by an extended Kalman filter  

Energy Technology Data Exchange (ETDEWEB)

In this contribution results are presented from the control of glucose during a yeast fed-batch cultivation. For glucose measurements a special flow injection analysis (FIA) system was employed, which uses a glucose oxidase solution instead of immobilized enzymes. To avoid the large delay time caused by probing systems samples containing cells, i.e., samples containing the ordinary culture broth, are injected into the FIA system. Based on a special evaluation method the glucose concentration can be measured with a delay time of about 60 s. Employing an extended Kalman filter, the biomass, the glucose concentration as well as the {mu}{sub max} (Monod model) are estimated. Based on the estimation a feed forward and a PI-control with a set point of 0.5 g/l was carried out. The mean deviation of the set point and the estimated value as well as the set point and the measured value were 0.05 and 0.11 g/l respectively for a control period of 8 h producing a cell dry mass of more than 6 g/l. (orig.)

Hitzmann, B.; Broxtermann, O.; Cha, Y.L.; Sobieh, O.; Staerk, E.; Scheper, T. [Hannover Univ. (Germany). Inst. fuer Technische Chemie

2000-10-01

 
 
 
 
181

Relationships between hemoglobin A 1c and spot glucose measurements in Nigerians with type 2 diabetes mellitus.  

UK PubMed Central (United Kingdom)

BACKGROUND: Glycosylated hemoglobin, HbA 1c is the most acceptable measure of chronic glycemia. It is not widely available and/or affordable in Nigeria. The mean of the monthly fasting plasma glucose (MFPG) of the preceding 3 months is often used as surrogate for assessing chronic glycemia. OBJECTIVE: To determine the relationships among fasting plasma glucose (FPG), 2-hour post-prandial glucose (2-hPG), HbA1c, and MFPG. MATERIALS AND METHODS: Hospital records were used to derive the MFPGs of diabetic subjects from the mean of their monthly FPGs of the preceding three months. Other data extracted included the patient's age, sex, body mass index (BMI), waist circumference (WC), and duration of diabetes mellitus (DMDU). FPG, 2- hPG and HbA 1c were determined during this index consultation. RESULTS: Ninety five persons (65 males, 30 females) with type 2 were included in the study. Their mean age and DMDU were 54.7 ± 8.9 years and 8.1 ± 6.1 years, respectively. Their mean WC, BMI, FPG, 2-hPG, HbA1c, and MFPG were 100.2 ± 11.0 cm, 24.2 ± 4.3 kgm/2, 7.5 ± 2.4 mmol/l, 10.4 ± 4.1 mmol/l, 8.2 ± 2.2%, and 5.9 ± 2.2 mmol/l, respectively. The males were significantly older (57.5 ± 8.4 vs 49.3 ± 7.6, P<0.001) while the females had higher waist circumference and BMI than their male counterparts: 104.8 ± 11.6 cm vs 92.8 ± 10.1 cm, P<0.004; and 25.8 ± 4.9 kg/m 2 vs 23.3 ± 3.7 kg/m 2 , P<0.005, respectively. There were no significant differences in FPG, 2-hPG, MFPG and HbA1c levels between male and female subjects. There were significant positive correlations between FPG and HbA1c (r=0.45, P=0.05) and between 2-hPG and HbA1c (r=0.52, P=0.01), but there was no positive correlation between MFPG and HbA1c (r=-0.20, P=0.18). CONCLUSION: There is no positive correlation between MFPG and HbA 1c and thus MFPG may not be a good surrogate for HbA1c in assessment of chronic glycemia in our patients.

Edo AE; Akhuemokhan K

2012-01-01

182

A CAMAC unit for charge measuring and pulse shape recording based on a fast, 8-bit parallel analog-to-digital converter  

International Nuclear Information System (INIS)

A device designed mainly for measuring systems for testing parameters of some type of detectors used in the high energy physics is described. The device is one-module CAMAC unit. It is equipped in a fast, 8-bit parallel analog-to-digital converter ''flash''type with a gated integrator at the input and a static RAM (4096 x 8 bit) at the output. The device enables measurements of the charge in pulses from detectors or registration of the shape of these pulses. The construction, operation and parameters of the circuits of the device are described and the way of programming functions using CAMAC dataway is given. 8 refs., 9 figs. (author).

1990-01-01

183

Purity of analog spin in isobaric analog resonances  

Energy Technology Data Exchange (ETDEWEB)

It is shown that the position of the pole of the inverse average X-matrix of an isolated isobaric analog resonance (IAR) is a very useful parameter, which allows one to distinguish between the weak and the strong coupling case of the finestructure distribution of the resonance. It gives also a direct measure of the purity of analog spin of the resonance. As an example the lowest IAR in /sup 208/Bi is discussed.

von Brentano, P.

1982-06-01

184

The patient acceptable symptom state of chronic musculoskeletal pain measured on a visual analog scale in Moroccan patients.  

UK PubMed Central (United Kingdom)

OBJECTIVES: The patient acceptable symptom state (PAccSS) is the value beyond which patients consider themselves well. Our aim was to determine the PAccSS of chronic pain in Moroccan outpatients suffering from chronic rheumatic diseases and to identify contributors to PAccSS. METHODS: A 4-week prospective study of 387 outpatients suffering from chronic rheumatic diseases was carried out. Pain level was evaluated using a 0-100?mm visual analog scale. An anchoring method based on patient's opinion was used. The PAccSS was defined as the 75th percentile of the score for patients who considered their state satisfactory. Pearson's chi-square and binary logistic regression were used to analyze the data. RESULTS: The underlying disease of the patients (mean age 50?±?13 years; female sex 70%) was rheumatoid arthritis (N?=?102), ankylosing spondylitis (N?=?100), peripheral osteoarthritis (N?=?100), and degenerative back pain (N?=?85). The mean disease duration was 7.4?±?6.7 years. At the time of the study, the level of pain was 44?±?23?mm. One hundred ninety (49%) patients considered their state as satisfactory, and the PAccSS threshold was 50?mm. Significant contributors to PAccSS were high educational level, high socioeconomic status, higher functional status scores, and shorter term disease duration. CONCLUSION: Half of patients were satisfied of their disease state, while the PAccSS threshold of pain was unexpectedly high. This could be explained by an overestimation of the pain intensity or a Moroccan patients' high tolerance to pain. The main protective factors that contribute to achieving the PAccSS were high educational level, high socioeconomic status, higher functional status, and shorter term disease duration.

Wariaghli G; Allali F; Berrada K; Idrissi Z; Hmamouchi I; Abouqal R; Hajjaj-Hassouni N

2013-01-01

185

Analogical Modeling and Quantum Computing  

CERN Multimedia

This paper serves as a bridge between quantum computing and analogical modeling (a general theory for predicting categories of behavior in varying contexts). Since its formulation in the early 1980s, analogical modeling has been successfully applied to a variety of problems in language. Several striking similarities between quantum mechanics and analogical modeling have recently been noted: (1) traditional statistics can be derived from a non-statistical basis by assuming data occurrences are accessed through a spin-up state (given two equally probable quantum states, spin-up and spin-down); (2) the probability of predicting a particular outcome is determined by the squaring of an underlying linear measure and is the result of decoherence (which occurs when a quantum system is observed); and (3) a natural measure of certainty (called the agreement) is based on one chance of guessing the right outcome and corresponds to the integrated squaring of Schroedinger's wave equation. Analogical modeling considers all ...

Skousen, R

2000-01-01

186

Prediction of interstitial glucose level.  

UK PubMed Central (United Kingdom)

Glucose is an important source of energy for cells. In clinical practice, we measure glucose level in blood and interstitial fluid. Each method has its pros and cons, and both levels correlate with each other. As the body tries to maintain the glucose level within a particular range to avoid adverse effects, it is desirable to predict future glucose levels in order to aid provided health care. We can see this desire in research, e.g., research on glucose transporters of cells. As yet another example, we can see it with diabetic patients, patients in a metabolic intensive care unit, particularly. In this paper, a glucose level prediction method is proposed.

Koutny T

2012-01-01

187

Analog elements for transuranic chemistries  

International Nuclear Information System (INIS)

[en] The analytical technique for measuring trace concentrations of the analog rare earth elements has been refined for optimal detection. The technique has been used to determine the rare earth concentrations in a series of geological and biological materials, including samples harvested from controlled lysimeter investigations. These studies have demonstrated that any of the trivalent rare earth elements may be used as analog elements for the trivalent transuranics, americium and curium

1982-01-01

188

Glucose stimulation of protein acylation in the pancreatic ?-cell.  

UK PubMed Central (United Kingdom)

AIMS: To determine whether protein acylation plays a role in the effects of glucose on the insulin secreting ?-cell. MAIN METHODS: The measurement of (3)H-palmitate incorporation into protein in the INS 832/13 cell that has a robust and well-characterized biphasic insulin secretory response to stimulation with glucose. KEY FINDINGS: Stimulating the cells with glucose increased the incorporation of (3)H-palmitic acid into protein by up to 90%. Similarly, 2-aminobicyclo [2.2.1] heptane-2-carboxylic acid (BCH) the non-metabolizable analog of leucine that mimics the stimulatory effect of glucose on insulin secretion also increased the incorporation of (3)H-palmitic acid into protein. Treatment of cell lysates with hydroxylamine substantially reduced the incorporation indicating that most of the incorporation was due to enzymatic palmitoylation of proteins. Cerulenin, a classical inhibitor of protein acylation also substantially reduced the incorporation. Using PAGE and autoradiography a glucose-induced increase in protein palmitoylation and specific glucose-induced increases in the palmitoylation of proteins of 30, 44, 48 and 76kD were identified. SIGNIFICANCE: The data suggest that protein acylation plays multiple roles in ?-cell function.

Abdel-Ghany M; Sharp GW; Straub SG

2010-12-01

189

A Study Measuring the Effect of High Serum Triglyceride and Cholesterol on Glucose Elevation in Human Serum  

Directory of Open Access Journals (Sweden)

Full Text Available Objectives: The purpose of this study is to further confirm the results documented in previous studies and to test the hypothesis of the presence of any correlation and if found, the regression nature of such correlation between triglyceride and glucose levels in one hand and cholesterol and glucose levels in the other hand.Methods: Samples were collected between March and August 2009 from 438 of both males and females from two patient groups; a) nondiabetic patients, b) non-insulin dependent type II diabetic patients. The patients’ serum glucose; cholesterol and triglyceride were simultaneously determined. A comparison study was conducted on the effect of the elevated level of each of the parameters (Cholesterol and Triglyceride) on glucose elevation.Results: The results showed that there was a significant difference in the number of cases with high glucose values >110 mg/dl among the three different study groups. There was a significant difference in the number of cases with glucose values >110 mg/dl between the two different study groups; 1) triglyceride 201 mg/dl, 2) triglyceride >151 mg/dl and cholesterol>201 mg/dl.Conclusion: The elevation in triglyceride but not cholesterol has the same effect of both triglyceride and cholesterol elevation together on the association with increasing levels of high glucose in blood.

Mohammed Wael Daboul

2011-01-01

190

Glucose metabolism in uremia.  

UK PubMed Central (United Kingdom)

Formation of CO2 from uniformly labeled 14C-glucose was measured in liver slices from uremic and normal rats. Both CO2 formation and lactate concentration were decreased in the uremic liver slices suggesting an inhibition of glucose oxidation. In addition, a net loss of glucose from the medium in the uremic preparation and a net gain in the normal controls suggested that there was increased nonoxidative utilization in the uremic liver. Such changes could not be explained by differences in glucose availability consequent to alterations in glycogen degradation. The most likely explanation is diversion of glucose into other biosynthetic pathways such as the synthesis of amino acids. In this regard, synthesis of glutamine appeared to be enhanced in uremia. Thus, products of carbohydrate metabolism may provide a potential mechanism for disposition of ammonia and synthesis of amino acids in uremia.

Quintanilla A; Shambaugh GE 3rd; Gibson TP; Craig R

1980-07-01

191

Avaliação do grau de satisfação entre os usuários de amplificação de tecnologia analógica e digital/ Evaluation of satisfaction measures of analog and digital hearing aid users  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese OBJETIVO: objetivo desta pesquisa foi investigar o grau de satisfação entre os usuários de Aparelho de Amplificação Sonora (AAS) de tecnologia analógica e digital. FORMA DE ESTUDO: clínico com coorte transversal. MATERIAL E MÉTODO: A amostra foi constituída de 40 usuários de AAS unilateral, sendo 20 de tecnologia analógica (Grupo I) e 20 de tecnologia digital (Grupo II). Os indivíduos são portadores de perda auditiva neurossensorial, de configuração plana, (more) de grau leve a moderado, com idade entre 40 e 95 anos. O instrumento de avaliação utilizado foi o International Outcome Inventory for Hearing Aids (IOI-HA - Versão em Português) proposto por Cox et al. (2002). RESULTADOS: Os resultados mostraram que os usuários do Grupo II utilizam o AAS por mais tempo diariamente e também apresentam um grau de dificuldade menor em determinadas situações com o uso da amplificação, comparado aos usuários do Grupo I. Os usuários do Grupo II relatam que sua perda auditiva não afeta em nada sua relação com terceiros. CONCLUSÃO: Apesar de os resultados revelarem que os usuários do Grupo I apresentam um handicap auditivo mais acentuado comparado aos usuários do Grupo II, o grau de satisfação com relação à amplificação não apresenta diferença significativa entre os dois grupos. Abstract in english AIM: the objective of this study was to investigate the satisfaction measure of analog and digital hearing aid users. STUDY DESIGN: clinical with transversal cohort. MATERIAL AND METHOD: Among the 40 interviewed subjects, 20 were analog hearing aid users (Group I) and 20 were digital hearing aid users (Group II). The subjects had mild to moderate sensorineural hearing impairment, and were aged 45 to 95 years old. RESULTS: The inventory of self-assessment completed by the (more) hearing aid users was the International Outcome Inventory for Hearing Aids (IOI-HA - Portuguese version) proposed by Cox et al. (2002). The users of Group II used the hearing aid longer every day than the analog hearing aid users (Group I). The users of Group II have fewer difficulties with the amplification at some situations than the users of Group I. Despite the fact that users of Group I have presented mode deficit than the users of Group II, the results agree that all the subjects reported satisfaction with their hearing aids.

Magni, Cristiana; Freiberger, Francine; Tonn, Kátia

2005-10-01

192

Avaliação do grau de satisfação entre os usuários de amplificação de tecnologia analógica e digital Evaluation of satisfaction measures of analog and digital hearing aid users  

Directory of Open Access Journals (Sweden)

Full Text Available OBJETIVO: objetivo desta pesquisa foi investigar o grau de satisfação entre os usuários de Aparelho de Amplificação Sonora (AAS) de tecnologia analógica e digital. FORMA DE ESTUDO: clínico com coorte transversal. MATERIAL E MÉTODO: A amostra foi constituída de 40 usuários de AAS unilateral, sendo 20 de tecnologia analógica (Grupo I) e 20 de tecnologia digital (Grupo II). Os indivíduos são portadores de perda auditiva neurossensorial, de configuração plana, de grau leve a moderado, com idade entre 40 e 95 anos. O instrumento de avaliação utilizado foi o International Outcome Inventory for Hearing Aids (IOI-HA - Versão em Português) proposto por Cox et al. (2002). RESULTADOS: Os resultados mostraram que os usuários do Grupo II utilizam o AAS por mais tempo diariamente e também apresentam um grau de dificuldade menor em determinadas situações com o uso da amplificação, comparado aos usuários do Grupo I. Os usuários do Grupo II relatam que sua perda auditiva não afeta em nada sua relação com terceiros. CONCLUSÃO: Apesar de os resultados revelarem que os usuários do Grupo I apresentam um handicap auditivo mais acentuado comparado aos usuários do Grupo II, o grau de satisfação com relação à amplificação não apresenta diferença significativa entre os dois grupos.AIM: the objective of this study was to investigate the satisfaction measure of analog and digital hearing aid users. STUDY DESIGN: clinical with transversal cohort. MATERIAL AND METHOD: Among the 40 interviewed subjects, 20 were analog hearing aid users (Group I) and 20 were digital hearing aid users (Group II). The subjects had mild to moderate sensorineural hearing impairment, and were aged 45 to 95 years old. RESULTS: The inventory of self-assessment completed by the hearing aid users was the International Outcome Inventory for Hearing Aids (IOI-HA - Portuguese version) proposed by Cox et al. (2002). The users of Group II used the hearing aid longer every day than the analog hearing aid users (Group I). The users of Group II have fewer difficulties with the amplification at some situations than the users of Group I. Despite the fact that users of Group I have presented mode deficit than the users of Group II, the results agree that all the subjects reported satisfaction with their hearing aids.

Cristiana Magni; Francine Freiberger; Kátia Tonn

2005-01-01

193

Measurement of proliferation and disappearance of regulatory T cells in human studies using deuterium-labeled glucose.  

Science.gov (United States)

The in vivo proliferation and disappearance kinetics of lymphocytes may be estimated in humans from rates of deuterium-labeled glucose ((2)H(2)-glucose) incorporation into DNA. This protocol describes its application to regulatory T cells (Treg). Because Treg divide frequently, (2)H(2)-glucose is a suitable precursor, achieving high levels of enrichment over a short period. Being nonradioactive and readily administered, it is appropriate for human studies.There are four phases to the method: labeling, sampling, analysis and modeling. Labeling consists of administration of (2)H(2)-glucose, either intravenously or orally; during this phase, small blood samples are taken to monitor plasma glucose enrichment. Sampling occurs over the ensuing ?3 weeks; PBMC are collected and sorted according to surface marker expression. Cell separation can be achieved by fluorescence-activated cell sorting (FACS) using CD4, CD45RA and CD25 to define memory Treg (CD4(+)CD25(hi)), or by a combination of magnetic bead separation and FACS. Analysis consists of DNA extraction, hydrolysis, derivatization to the pentafluoro tri-acetate (PFTA) derivative, and quantitation of deuterium content by gas-chromatography mass-spectrometry (GC/MS). The ratio of deuterium enrichment in cellular DNA relative to plasma glucose is used to derive the fraction of new cells in the sorted population, and this is modeled as a function of time to derive proliferation and disappearance kinetics. PMID:21287340

Vukmanovic-Stejic, Milica; Zhang, Yan; Akbar, Arne N; Macallan, Derek C

2011-01-01

194

Measurement of proliferation and disappearance of regulatory T cells in human studies using deuterium-labeled glucose.  

UK PubMed Central (United Kingdom)

The in vivo proliferation and disappearance kinetics of lymphocytes may be estimated in humans from rates of deuterium-labeled glucose ((2)H(2)-glucose) incorporation into DNA. This protocol describes its application to regulatory T cells (Treg). Because Treg divide frequently, (2)H(2)-glucose is a suitable precursor, achieving high levels of enrichment over a short period. Being nonradioactive and readily administered, it is appropriate for human studies.There are four phases to the method: labeling, sampling, analysis and modeling. Labeling consists of administration of (2)H(2)-glucose, either intravenously or orally; during this phase, small blood samples are taken to monitor plasma glucose enrichment. Sampling occurs over the ensuing ?3 weeks; PBMC are collected and sorted according to surface marker expression. Cell separation can be achieved by fluorescence-activated cell sorting (FACS) using CD4, CD45RA and CD25 to define memory Treg (CD4(+)CD25(hi)), or by a combination of magnetic bead separation and FACS. Analysis consists of DNA extraction, hydrolysis, derivatization to the pentafluoro tri-acetate (PFTA) derivative, and quantitation of deuterium content by gas-chromatography mass-spectrometry (GC/MS). The ratio of deuterium enrichment in cellular DNA relative to plasma glucose is used to derive the fraction of new cells in the sorted population, and this is modeled as a function of time to derive proliferation and disappearance kinetics.

Vukmanovic-Stejic M; Zhang Y; Akbar AN; Macallan DC

2011-01-01

195

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)

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.

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

196

Moving Beyond the Limitations of the Visual Analog Scale for Measuring Pain: Novel Use of the General Labeled Magnitude Scale in a Clinical Setting.  

UK PubMed Central (United Kingdom)

OBJECTIVE: Quantifying pain intensity is challenging, particularly for patients with chronic pain. The visual analog scale (VAS) is limited by ceiling effects that often leave patients with no ability to quantify worsening pain. The goal of this study was to determine whether the general Labeled Magnitude Scale (gLMS) can be feasibly used to measure pain clinically while overcoming limitations of the VAS. DESIGN: Eighty patients (mean age, 53.7 yrs) scheduled for evaluation of a painful complaint were asked to rate their current pain using the gLMS and the VAS. The time necessary to administer the gLMS was recorded to determine feasibility. The difference in rating between the two scales (VAS and gLMS) was the main outcome measure. RESULTS: After scaling and rounding off the gLMS scores for direct comparison, it was found that the gLMS scores were significantly lower than the corresponding VAS scores by a mean of 1.78 (P < 0.001). The mean time to administer the gLMS was 2.66 mins. CONCLUSIONS: These results suggest that the gLMS has great potential and can be feasibly used to measure pain intensity clinically. The gLMS scores were consistently lower than the VAS scores, thus reducing the ceiling effect and allowing range at the high end of the scale for rating worsening pain.

González-Fernández M; Ghosh N; Ellison T; McLeod JC; Pelletier CA; Williams K

2013-07-01

197

Calculation of HbA1c and glycated albumin from serially measured self-monitored blood glucose in patients with type 1 diabetes mellitus.  

UK PubMed Central (United Kingdom)

BACKGROUND: Both HbA1c and glycated albumin (GA) values are influenced by weighted mean of preceding blood glucose levels depending on each half-life. Based on this principle, we developed formulas for calculation of HbA1c and GA using data from self-monitored blood glucose (SMBG). We also calculated HbA1c and GA in diabetic patients using the developed formulas. METHODS: This study included 9 patients with childhood-onset type 1 diabetes mellitus (6 males and 3 females; aged 11.4±4.2y). From the weekly mean blood glucose (MBG) values obtained by the SMBG data during the previous 20weeks, we calculated HbA1c and GA using the developed formulas and compared the calculated values with the measured values (n=42). RESULTS: The measured and the calculated values of HbA1c were 8.5±0.9% and 8.3±1.2%, respectively. The measured and the calculated values of GA were 24.9±3.7% and 26.4±4.0%, respectively. There were strong positive correlations between both values of HbA1c and GA (P<0.0001). CONCLUSIONS: The calculated HbA1c and GA values using the developed formulas from the SMBG data were generally in agreement with the measured values. Using the calculation formulas, the values of HbA1c and GA could be estimated from serially measured SMBG data.

Koga M; Suzuki S; Matsuo K; Tanahashi Y; Azuma H; Kasayama S

2013-08-01

198

Eight-bit analog-to-digital converter with preliminary storage of measured pulse amplitudes on a capacitor  

International Nuclear Information System (INIS)

A divice is described that has been designed tomeasure the height of about 8 pulses arriving simultaneously and to present the messurement results in the form of a parallel 8-decade binary code. The device operates in the standard way of data conversion: pulse height-time-pulse train-code (H-T-S-C). The H-T blocks of the device are used for the preliminary memorizing of the pulse height therefore it contains only two time-pulse train-code converters serving all 8(H-T) blocks being asked in pairs. Besides the main operations, the H-T blocks are used for amplifying, filtration, shaping and linear gating of measured signals

1973-01-01

199

Correlation between sweat glucose and blood glucose in subjects with diabetes.  

UK PubMed Central (United Kingdom)

BACKGROUND: Sweat contains glucose that can accurately reflect blood glucose. However, skin surface glucose can confound these measurements. METHODS: A perfusion method was used to rapidly harvest sweat from forearm sites on human subjects. The sweat samples were analyzed for glucose by high-performance liquid chromatography methods and compared with the results obtained with a blood glucose meter. RESULTS: The results of 23 different studies of seven individual subjects with diabetes show a strong correlation between sweat glucose and blood glucose. CONCLUSION: Sweat glucose, when properly harvested to prevent contamination from other sources on the skin's surface, can accurately reflect blood glucose levels.

Moyer J; Wilson D; Finkelshtein I; Wong B; Potts R

2012-05-01

200

Effects of exenatide twice daily versus sitagliptin on 24-h glucose, glucoregulatory and hormonal measures: a randomized, double-blind, crossover study.  

UK PubMed Central (United Kingdom)

AIM: To compare exenatide and sitagliptin glucose and glucoregulatory measures in subjects with type 2 diabetes. METHODS: An 8-week, double-blind, randomized, crossover, single-centre study. Eighty-six subjects (58% female, body mass index 35 ± 5 kg/m², haemoglobin A1c 8.3 ± 1.0%) received either exenatide 10 µg (subcutaneous) twice daily or sitagliptin 100 mg (oral) daily for 4 weeks and crossed to the other therapy for an additional 4 weeks. Main outcome was time-averaged glucose during the 24-h inpatient visits. RESULTS: Both treatments decreased average 24-h glucose, but exenatide had a greater effect [between-group difference: -0.67 mmol/l, 95% confidence interval (CI): -0.9 to -0.4 mmol/l]. Both treatments decreased 2-h postprandial glucose (PPG), area under the curve of glucose above 7.8 mmol/l (140 mg/dl) and 11 mmol/l (200 mg/dl) and increased the time spent with glucose between 3.9 and 7.8 mmol/l (70 and 140 mg/dl) during 24 h, but exenatide had a significantly greater effect (p < 0.05). Both treatments decreased postprandial serum glucagon, with exenatide having a greater effect (p < 0.005). Both treatments decreased fasting blood glucose to a similar degree (p = 0.766). Sitagliptin increased, while exenatide decreased, postprandial intact glucagon-like peptide-1. Both drugs improved homeostasis model assessment of ?-cell function (HOMA-B), with exenatide having a significantly greater effect (p = 0.005). Both exenatide and sitagliptin decreased 24-h caloric intake, with exenatide having a greater effect (p < 0.001). There was no episode of major hypoglycaemia. Adverse events were mild to moderate and mostly gastrointestinal in nature with exenatide. No study withdrawals were due to an adverse event. CONCLUSION: Compared to sitagliptin, exenatide showed significantly lower average 24-h glucose, 2-h PPG, glucagon, caloric intake and improved HOMA-B.

Berg JK; Shenouda SK; Heilmann CR; Gray AL; Holcombe JH

2011-11-01

 
 
 
 
201

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)

[en] 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

1977-06-30

202

Correlation of Health Related Quality of Life in Children with Inflammatory Bowel Disease, Their Parents and Physician as Measured by A Visual Analog Scale.  

UK PubMed Central (United Kingdom)

Inflammatory bowel disease has previously been shown to affect children's health related quality of life (HRQOL) through the use of lengthy questionnaires. We examined if a pediatric patient's HRQOL, measured by a rapid visual analog scale ("feeling thermometer"), correlates with the perceptions of the HRQOL as determined by the patient's pediatric gastroenterologist and parent(s). Additionally, we attempted to determine if the HRQOL correlates with the patient's disease activity as determined by validated activity indices. METHODS:: A cross-sectional study of pediatric patients (age 7 to 21) who were diagnosed with Crohn disease, ulcerative colitis, or indeterminate colitis was conducted from January 2011 to May 2011. Each participant (patient, parent(s) and treating pediatric gastroenterologist) completed feeling thermometers to determine the symptom burden as well as therapeutic burden of the patient. The parent(s) and doctor were blinded to the patient's results. Pediatric Ulcerative Colitis Activity Index (PUCAI) or a Short Pediatric Crohn Disease Activity Index (S-PCDAI) was calculated. Correlations between the participant's perceived burdens as well as their calculated disease activity were determined. RESULTS:: Sixty-seven children and their families participated, resulting in 101 visits. Patients had a mean age of 15.0 years, and there were 38 males. There was a strong significant correlation between the patient's perceived symptom burden and that of the parent's (rho?=?0.59, p?analog scale that can be implemented in everyday practice to measure a pediatric patient's HRQOL.

Teitelbaum JE; Rajaraman RR; Jaeger J; Para S; Rakitt T

2013-06-01

203

Measurement of health-promoting properties in fruit dietary fibres: antioxidant capacity, fermentability and glucose retardation index.  

UK PubMed Central (United Kingdom)

The aim of this work was to compare some in vitro health-promoting properties in fruit dietary fibre (antioxidant activity, fermentability and glucose retardation index), which could be useful to predict their physiological effects better than physico-chemical analyses. These properties were evaluated in mango and lemon peel fibre. Mango fibre was better than lemon fibre because of the highest values of antioxidant activity (67.6%) and glucose retardation index (21.5%). Antioxidant activity is proposed as a new health-promoting property associated to dietary fibre.

Larrauri JA; Goni I; Martin-Carron N; Ruperez P; Saura-Calixto F

1996-08-01

204

Glucose allostasis.  

Science.gov (United States)

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. PMID:12663459

Stumvoll, Michael; Tataranni, P Antonio; Stefan, Norbert; Vozarova, Barbora; Bogardus, Clifton

2003-04-01

205

Glucose allostasis.  

UK PubMed Central (United Kingdom)

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.

Stumvoll M; Tataranni PA; Stefan N; Vozarova B; Bogardus C

2003-04-01

206

Glucose allostasis  

DEFF Research Database (Denmark)

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.

Stumvoll, Michael; Tataranni, P Antonio

2003-01-01

207

Facile synthesis of 1,2,3-triazole analogs of SGLT2 inhibitors by 'click chemistry'.  

UK PubMed Central (United Kingdom)

Novel analogs of SGLT2 inhibitors containing the 1,2,3-triazole motif were designed and synthesized for urinary glucose excretion evaluation. The C-glucosides with triazole aglycone can be easily constructed by click chemistry. Most of the synthesized compounds increased urinary glucose excretion and demonstrated inhibition of glucose transport.

Li LT; Zhou LF; Li YJ; Huang J; Liu RH; Wang B; Wang P

2012-01-01

208

Fine structure of isobaric analogous nuclear states  

Energy Technology Data Exchange (ETDEWEB)

Medium-A nuclei were investigated using differential gamma-induction functions to define the isobaric analogous resonances split to components in proton-gamma reactions. Detailed experimental studies were performed to analyze the isobaric analogous states for /sup 63/Cu, /sup 56/Fe and /sup 52/Cr target nuclei. Theoretical predictions are given for correlations of isobaric analogous resonances occurring in different channels. New definitions of strength functions measured in different channels and of channel-free spreading width are proposed.

Fodor, I. (Hungarian Academy of Sciences, Budapest. Central Research Inst. for Physics)

1984-01-01

209

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

Digital Repository Infrastructure Vision for European Research (DRIVER)

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...

Andrea Tura; Stefano Sbrignadello; Domenico Cianciavicchia; Giovanni Pacini; Paolo Ravazzani

210

Defining a minimal clinically important difference for endometriosis-associated pelvic pain measured on a visual analog scale: analyses of two placebo-controlled, randomized trials  

Directory of Open Access Journals (Sweden)

Full Text Available Abstract Background When comparing active treatments, a non-inferiority (or one-sided equivalence) study design is often used. This design requires the definition of a non-inferiority margin, the threshold value of clinical relevance. In recent studies, a non-inferiority margin of 15 mm has been used for the change in endometriosis-associated pelvic pain (EAPP) on a visual analog scale (VAS). However, this value was derived from other chronic painful conditions and its validation in EAPP was lacking. Methods Data were analyzed from two placebo-controlled studies of active treatments in endometriosis, including 281 patients with laparoscopically-confirmed endometriosis and moderate-to-severe EAPP. Patients recorded EAPP on a VAS at baseline and the end of treatment. Patients also assessed their satisfaction with treatment on a modified Clinical Global Impression scale. Changes in VAS score were compared with patients' self-assessments to derive an empirically validated non-inferiority margin. This anchor-based value was compared to a non-inferiority margin derived using the conventional half standard deviation rule for minimal clinically important difference (MCID) in patient-reported outcomes. Results Anchor-based and distribution-based MCIDs were-7.8 mm and-8.6 mm, respectively. Conclusions An empirically validated non-inferiority margin of 10 mm for EAPP measured on a VAS is appropriate to compare treatments in endometriosis.

Gerlinger Christoph; Schumacher Ulrike; Faustmann Thomas; Colligs Antje; Schmitz Heinz; Seitz Christian

2010-01-01

211

The Use of a CoolSense Device to Lower Pain Sensation During Finger Pricking While Measuring Blood Glucose in Diabetes Patients-A Randomized Placebo.  

UK PubMed Central (United Kingdom)

Abstract Background: Patients with type 1 diabetes and a significant portion of patients with type 2 diabetes must use subcutaneous insulin injections, in order to maintain normoglycemia and to prevent immediate and long-term complications. For these patients, testing blood glucose levels more frequently is necessary to safely achieve glycated hemoglobin targets. In the current study, the effects of a CoolSense™ device (CoolSense Medical Ltd., Tel Aviv, Israel) were examined in relieving pain caused by needle-pricking for glucose measurements in adult patients with diabetes. Subjects and Methods: One hundred seventy-seven patients assessed the severity of pain they experienced during needle-pricking. The patients were randomly divided into an experimental group or a control group that used either a cooled CoolSense instrument or a non-cooled device, respectively. Participants were asked to rank the severity of their pain by a questionnaire developed for this study. Blood glucose levels were monitored as a control. Results: The majority of participants (58.3-71.7%; P<0.001) reported significant ache during measurements, the desire for an instrument that relieves pain, and its negative influence on their quality of life. Significant differences were indicated in pain perception between the experimental group and the control group that served as placebo, with no differences in blood glucose measurements in the groups. Conclusions: The CoolSense instrument significantly reduces subjective pain felt by patients and can therefore serve as an additional tool for clinicians to help ease the needle-pricking pain. Future study is needed in order to provide information regarding the practical use of the instrument and its effect on hyper- and hypoglycemia.

Wainstein J; Chimin G; Landau Z; Boaz M; Jakubowicz D; Goddard G; Bar-Dayan Y

2013-08-01

212

Measuring fatigue in rheumatoid arthritis: a cross-sectional study to evaluate the Bristol Rheumatoid Arthritis Fatigue Multi-Dimensional questionnaire, visual analog scales, and numerical rating scales.  

UK PubMed Central (United Kingdom)

OBJECTIVE: Current patient-reported outcome measures of fatigue in rheumatoid arthritis (RA) have limitations, providing only a global perspective. This study constructed a questionnaire (the Bristol RA Fatigue Multi-Dimensional Questionnaire [BRAF-MDQ]) from 45 preliminary questions derived from analysis of patient interviews and surveys and explored its structure for fatigue dimensions. The BRAF-MDQ and short BRAF numerical rating scales (NRS) and visual analog scales (VAS) for severity, effect, and ability to cope with fatigue were evaluated for validity. METHODS: Two hundred twenty-nine RA patients with fatigue (VAS score ?5 of 10) completed preliminary BRAF and comparator fatigue scales. Iterative analyses informed item removal or retention in the BRAF-MDQ and identification of subscales (using Cronbach's alpha for internal consistency and factor analysis to identify dimensions). The BRAF-MDQ and short scales were tested in relation to potentially associated variables for criterion and construct validity (Spearman's correlation). RESULTS: The 20-item BRAF-MDQ had good internal consistency (Cronbach's ? = 0.932), criterion validity (correlation with other fatigue scales: r = 0.643-0.813), and construct validity (correlations with disability, mood, helplessness, and pain: r = 0.340-0.627). Factor analysis showed 4 distinct dimensions (physical fatigue, living with fatigue, cognition fatigue, and emotional fatigue), which correlated well with the RA Multidimensional Assessment of Fatigue scale (r = 0.548-0.834). The BRAF VAS and NRS showed similar criterion and construct validity. CONCLUSION: The BRAF instruments include standardized NRS and VAS for fatigue severity, effect, and coping, are RA specific, and have evidence to support validity. The BRAF-MDQ uniquely measures 4 separate dimensions, which may facilitate development of individually-tailored fatigue management programs.

Nicklin J; Cramp F; Kirwan J; Greenwood R; Urban M; Hewlett S

2010-11-01

213

Self-adjustment of insulin dose using graphically depicted self-monitoring of blood glucose measurements in patients with type 1 diabetes mellitus.  

UK PubMed Central (United Kingdom)

BACKGROUND: There is a need for patients to be able to adjust their insulin doses accurately and independently during continuous subcutaneous insulin infusion (CSII) therapy in order to avoid glycemic excursions and improve glycemic control. Use of new technology has the potential to aid patients in visualizing their circadian patterns and improving their understanding of data provided by self-monitored blood glucose (SMBG) measurements. METHODS: A 24-week crossover study was performed in 25 patients with type 1 diabetes mellitus using CSII and SMBG. Patients were randomized either to entering blood glucose data into handwritten logbooks or to using the Accu-Chek SmartPix information management system (IMS) coupled with instructions from a training manual to aid interpretation of the IMS readings. Patients analyzed these chart readings every 2 weeks, and outpatient visits were scheduled for both arms every 6 weeks. RESULTS: There was a significantly lower mean overall blood glucose level with the IMS compared with use of a logbook (139 ± 16.2 versus 150 ± 19.8 mg/dl; ? = 10.8 mg/dl; p < .01), and a significantly higher proportion of blood glucose values was in the target range compared with use of a logbook (43.6% versus 38.5%; p < .001). Hypoglycemic events were also significantly lower with the IMS compared with logbooks (3.7 fewer events/6 weeks; p < .05). There was no significant difference between groups in the daily frequency of SMBG measurements. CONCLUSIONS: The use of an IMS, coupled with an easily understood training manual, enables patients to improve glycemic control by performing accurate and timely self-adjustments to their insulin regimens.

Reichel A; Rietzsch H; Ludwig B; Röthig K; Moritz A; Bornstein SR

2013-01-01

214

Glucose increases extracellular [Ca2+] in rat insulinoma (INS-1E) pseudoislets as measured with Ca2+-sensitive microelectrodes.  

UK PubMed Central (United Kingdom)

Secretory granules of pancreatic ?-cells contain high concentrations of Ca2+ ions that are co-released with insulin in the extracellular milieu upon activation of exocytosis. As a consequence, an increase in the extracellular Ca2+ concentration ([Ca2+]ext) in the microenvironment immediately surrounding ?-cells should be expected following the exocytotic event. Using Ca2+-selective microelectrodes we show here that both high glucose and non-nutrient insulinotropic agents elicit a reversible increase of [Ca2+]ext within rat insulinoma (INS-1E) ?-cells pseudoislets. The glucose-induced increases in [Ca2+]ext are blocked by pretreatment with different Ca2+ channel blockers. Physiological agonists acting as positive or negative modulators of the insulin secretion and drugs known to intersect the secretory machinery at different levels also induce [Ca2+]ext changes as predicted on the basis of their described action on insulin secretion. Finally, the glucose-induced [Ca2+]ext increase is strongly inhibited after disruption of the actin web, indicating that the dynamic [Ca2+]ext changes recorded in INS-1E pseudoislets by Ca2+-selective microelectrodes occur mainly as a consequence of exocytosis of Ca2+-rich granules. In conclusion, our data directly demonstrate that the extracellular spaces surrounding ?-cells constitute a restricted domain where Ca2+ is co-released during insulin exocytosis, creating the basis for an autocrine/paracrine cell-to-cell communication system via extracellular Ca2+ sensors.

Gerbino A; Maiellaro I; Carmone C; Caroppo R; Debellis L; Barile M; Busco G; Colella M

2012-05-01

215

Insulin analogs and cancer.  

UK PubMed Central (United Kingdom)

Today, insulin analogs are used in millions of diabetic patients. Insulin analogs have been developed to achieve more physiological insulin replacement in terms of time-course of the effect. Modifications in the amino acid sequence of the insulin molecule change the pharmacokinetics and pharmacodynamics of the analogs in respect to human insulin. However, these changes can also modify the molecular and biological effects of the analogs. The rapid-acting insulin analogs, lispro, aspart, and glulisine, have a rapid onset and shorter duration of action. The long-acting insulin analogs glargine and detemir have a protracted duration of action and a relatively smooth serum concentration profile. Insulin and its analogs may function as growth factors and therefore have a theoretical potential to promote tumor proliferation. A major question is whether analogs have an increased mitogenic activity in respect to insulin. These ligands can promote cell proliferation through many mechanisms like the prolonged stimulation of the insulin receptor, stimulation of the IGF-1 receptor (IGF-1R), prevalent activation of the extracellular-signaling-regulated kinase (ERK) rather than the protein kinase B (PKB/AKT) intracellular post-receptor pathways. Studies on in vitro models indicate that short-acting analogs elicit molecular and biological effects that are similar to those of insulin. In contrast, long-acting analogs behave differently. Although not all data are homogeneous, both glargine and detemir have been found to have a decreased binding to receptors for insulin but an increased binding to IGF-1R, a prevalent activation of the ERK pathway, and an increased mitogenic effect in respect to insulin. Recent retrospective epidemiological clinical studies have suggested that treatment with long-acting analogs (specifically glargine) may increase the relative risk for cancer. Results are controversial and methodologically weak. Therefore prospective clinical studies are needed to evaluate the possible tumor growth-promoting effects of these insulin analogs.

Sciacca L; Le Moli R; Vigneri R

2012-01-01

216

From analog to digital  

CERN Document Server

Analog-to-digital conversion and its reverse, digital-to-analog conversion, are ubiquitous in all modern electronics, from instrumentation and telecommunication equipment to computers and entertainment. We shall explore the consequences of converting signals between the analog and digital domains and give an overview of the internal architecture and operation of a number of converter types. The importance of analog input and clock signal integrity will be explained and methods to prevent or mitigate the effects of interference will be shown. Examples will be drawn from several manufacturers' datasheets.

Belleman, J

2008-01-01

217

Precision of glucose measurements in control sera by isotope dilution/mass spectrometry: proposed definitive method compared with a reference method  

Energy Technology Data Exchange (ETDEWEB)

This improved isotope-dilution gas chromatographic/mass spectrometric (GC/MS) method, in which (/sup 13/C)glucose is the internal standard, meets the requirements of a Definitive Method. In a first study with five reconstituted lyophilized sera, a nested analysis of variance of GC/MS values indicated considerable among-vial variation. The CV for 32 measurements per serum ranged from 0.5 to 0.9%. However, concentration and uncertainty values (mmol/L per gram of serum) assigned to one serum by the NBS Definitive Method (7.56 +/- 0.28) were practically identical to those obtained with the proposed method (7.57 +/- 0.20). In the second study, we used twice more (/sup 13/C)glucose diluent to assay four serum pools and two lyophilized sera. The CV ranged from 0.26 to 0.5% for the serum pools and from 0.28 to 0.59% for the lyophilized sera. In comparison, results by the hexokinase/glucose-6-phosphate dehydrogenase reference method agreed within acceptable limits with those by the Definitive Method but tended to be slightly higher (up to 3%) for lyophilized serum samples or slightly lower (up to 2.5%) for serum pools.

Pelletier, O.; Arratoon, C.

1987-08-01

218

Biconical tapered optical fiber biosensor for measuring refractive index of a-amino acids in aqueous D-glucose and sucrose solution  

Science.gov (United States)

A single-mode biconical tapered optical fiber (BTOF) sensor was utilized for sensing the variation of refractive index (RI) with concentration of D-glucose in double distilled deionized water and measuring of RI of amino acids (AAs) in carbohydrate solutions. This method showed a rewarding ability in understanding the basis of biomolecular interactions in biological systems. The BTOF is fabricated by heat pulling method, utilizing a CO2 laser. The detection limit of the BTOF was 50 ppb for the D-glucose concentration ranging from 0 to 80 ppm, and RI detection limit corresponding to these concentrations in the range at 1.3333 to 1.3404 was 5.4×10-6 as a refractometer sensor. The response of the BTOF shows that the different kinds of interactions of various groups of AAs such as L-alanine, L-leucine, and L-cystein with D-glucose, sucrose and water molecules depend on functional groups in AAs such as OH, SH;CH2;NH3+ ,COO-. These results can be interpreted in terms of solute-solute and solute-solvent interactions and structure making/breaking ability of solutes in the given solution.

Zibaii, M. I.; Latifi, H.; Karami, M.; Gholami, M.; Hosseini, S. M.; Ghezelayagh, M. H.

2010-04-01

219

Higher morning to evening ratio in total dose of twice-daily biphasic insulin analog might be effective in achieving glucose control in patients with poorly controlled type 2 diabetes.  

UK PubMed Central (United Kingdom)

BACKGROUND: The aims of this study are to investigate not only the glucose-lowering effectiveness of twice-daily premixed insulin lispro 25 (Humalog(®) Mix25(™), Eli Lilly and Co., Indianapolis, IN), but also the optimal divided ratio of total Mix25 dose in Korean patients with poorly controlled type 2 diabetes. SUBJECTS AND METHODS: In this retrospective study, we retrieved data for subjects who were on intensive insulin therapy with twice-daily Mix25 regimen for at least 24 weeks. Changes of hemoglobin A1c (HbA(1c)) and other clinical and laboratory parameters were evaluated. Two groups were defined according to dose ratio of pre-breakfast to pre-dinner insulin at 24 weeks: Group I, pre-breakfast:pre-dinner insulin dose ratio=50:50; Group II, ratio=53:47-75:25. RESULTS: In total, 143 subjects were ultimately analyzed in this study. Twice-daily Mix25 significantly improved HbA(1c) levels from 10.1% to 7.7%, and 34% of patients had reached the target glycemic goal (HbA(1c)<7%) after 24 weeks. Compared with Group I, a significant reduction in HbA(1c) (Group I vs. Group II, -1.9±0.3% vs. -2.8±0.3%, P=0.02) and a larger proportion of subjects with HbA(1c)<7% (23.2% vs. 46.7%, P=0.01) were observed in subjects in Group II. Among clinical and laboratory factors, duration of diabetes (odd ratios [OR]=0.93, 95% confidence interval [CI] 0.86-0.99, P=0.04) and history of sulfonylurea use (OR=0.27, 95% CI 0.10-0.72, P=0.01) were independently associated with achieving target HbA(1c) levels less than 7%. CONCLUSIONS: Twice-daily Mix25 is an effective option for Korean subjects with type 2 diabetes having uncontrolled hyperglycemia. A higher pre-breakfast/pre-dinner dose ratio (53:47-75:25) might be taken into consideration as an initial protocol to accomplish better glycemic control in twice-daily Mix25.

Lee YH; Lee BW; Kwon HJ; Kang ES; Cha BS; Lee HC

2012-06-01

220

Assessment of local cerebral glucose utilization and protein synthesis in a rat brain tumor model. Simultaneous measurement by quantitative double-tracer autoradiography  

Energy Technology Data Exchange (ETDEWEB)

Quantitative assessment of local cerebral glucose utilization (ICGU) with (/sup 18/F) 2-fluoro-2-deoxy-D-glucose (/sup 18/FDG) and of local cerebral protein synthesis (ICPS) with L-(1-/sup 14/C)-valine (/sup 14/C-valine) were simultaneously performed by double-tracer autoradiography in an implanted rat brain tumor model in awake animals. ICPS was measured by both the three-compartment kinetic method and the free /sup 14/C-valine washout method. In tumor tissue, the ICGU rate was significantly greater than that in control brain cortex (p < 0.05). The ICPS rate was also significantly higher in tumor tissue than in normal brain cortical tissue (p < 0.001), according to both methods of measurement. ICGU and ICPS were also assessed in peritumoral brain tissue. In the parietal cortex ipsilateral to the tumor, the ICGU rate was lower than that on the contralateral side and was reduced by 30 % as compared to normal brain cortex (p < 0.05). No significant difference in the ICPS rate was observed between the ipsilateral and contralateral cortices. Also, there was no significant difference in the ICPS rate as measured by the kinetic and /sup 14/C-valine washout methods. The results of this study imply that, in brain tumor tissue, the rate of protein synthesis is significantly greater than that of glucose utilization. The ICGU rate in the cortex ipsilateral to the tumor was always depressed, whereas the ICPS rate was similar in the two cortices. Histopathological evaluation revealed normal cell structure in the ipsilateral cortex. The author concludes that ICPS is a more suitable marker than ICGU in the evaluation of brain tissue function.

Kirikae, Michihiro

1988-11-01

 
 
 
 
221

Assessment of the Glycotronic C blood glucose meter.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

The performance of the Glycotronic C blood glucose meter, a pocket sized glucose strip meter, was assessed on the ward and in the laboratory. Theoretically there is a relation between blood glucose concentration, plasma glucose concentration and haematocrit when glucose is measured using conventiona...

Forrest, A R; Pitt, E J

222

Peptide analogs of bombesin  

UK PubMed Central (United Kingdom)

Linear peptide analogs of bombesin with modified amino acid residues at various positions. A peptide of a group of bombesin analogs according to this invention contains either a -CH2NH2- pseudopeptide bond, a (3S,4S)-4-amino-3-hydroxy- 6-methylheptanoic acid residue, or a (3S,4S)-4-amino-3- hydroxy-5-phenylpentanoic acid residue.

COY DAVID H; MOREAU JACQUES-PIERRE; KIM SUN HYUK

223

Analog filters using Matlab  

CERN Multimedia

Presents an introduction to analog filters for senior undergraduate and graduate students. This book covers the synthesis of analog filters as well as many other filter types including passive filters and filters with distributed elements. It also addresses the basic circuit elements for the filters.

Wanhammar, Lars

2009-01-01

224

Simultaneous measurement of local glucose utilization and blood flow in the rat brain: an autoradiographic method using two tracers labeled with carbon-14  

Energy Technology Data Exchange (ETDEWEB)

A simplified technique that uses two radionuclide tracers has been devised to measure local cerebral glucose utilization (ICGU) and local cerebral blood flow (ICBF) in the same rat. The method employs (/sup 14/C)-2-deoxyglucose and (/sup 14/C)iodoantipyrine to produce an autoradiogram before and another after extraction into chloroform of the (/sup 14/C)iodoantipyrine from the brain sections. The chloroform-extracted autoradiogram yields ICGU, and the difference in tissue carbon-14 concentration between the two autoradiograms permits calculation of ICBF. The double-isotope technique provides values of ICGU and ICBF that are statistically indistinguishable from those derived from conventional single-isotope methods.

Furlow, T.W. Jr.; Martin, R.M.; Harrison, L.E.

1983-03-01

225

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

Energy Technology Data Exchange (ETDEWEB)

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

Wajngot, A.; Khan, A.; Giacca, A.; Vranic, M.; Efendic, S. (Karolinska Hospital, Stockholm (Sweden))

1990-11-01

226

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

International Nuclear Information System (INIS)

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

1990-01-01

227

Role of glucose signaling in yeast metabolism  

Energy Technology Data Exchange (ETDEWEB)

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

Dam, K. van [Univ. of Amsterdam (Netherlands). E.C. Slater Inst.

1996-10-05

228

Visual Analog Patient Satisfaction Scale  

Directory of Open Access Journals (Sweden)

Full Text Available Objectives: Measuring patient satisfaction is one of the essential parts of determining the quality of medical care. However, for a physician wishing to perform this measurement, there is no practical, commonly used, and Turkish-adapted scoring tool which can be used for different diseases. In this paper, a novel scoring tool called “Visual Analog Patient Satisfaction Scale,” which aims to measure patient satisfaction with medical care, is presented.Study Design: Outcome and patient satisfaction scales were reviewed. A novel scaling system was developed using the experience obtained by the practice and by observations with patients.Results: This scale includes a vertical line and accompanying two faces at its inferior and superior ends, representing complete dissatisfaction and full satisfaction. The patient signs the point on the line which matches his/her level of satisfaction with the medical care. The scoring is made between 0 to 10. The Visual Analog Patient Satisfaction Scale takes advantage of two validated and commonly-used scales (Visual Analog Pain Scale and Wong-Baker Scale). It is an easy-to-understand and practical scoring tool which can be applied to patients of every age and educational level. The drawback of the scale is its insensitivity to the components of satisfaction, in other words, what makes the patient satisfied or dissatisfied.Conclusion: By knowing its limitations, one can use the scale to measure “the general level of satisfaction with medical care” objectively and practically.

Cumhur KILINCER; Mehmet ZILELI

2006-01-01

229

[Algorithm for extracorporal blood glucose regulation (author's transl)  

UK PubMed Central (United Kingdom)

A control mechanism is described, based on a simple proportional/differential regulation. The calculation takes one minute and it takes into account glucose degradation, insulin half life in vivo, and the delay between blood sampling and insulin action on the blood glucose value. This is repeated continuously every minute (short time mode) or every 5 minutes or more (long time mode), depending on the rate of change of the blood glucose. Operator decision is based on digitally converted tables, which are analogous to the graph of proportional control, and on glucose equivalent tables, which give the insulin effect on glucose as a function of time.

Kruse-Jarres JD; Bresch M; Lehmann U

1979-07-01

230

Analogies in Theoretical Physics  

Science.gov (United States)

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 nonobvious interplay between these levels is involved. In this paper I will discuss two cases sufficiently intricate to illustrate some ways of how analogies work. The first topic is the introduction of spontaneous symmetry breaking in particle physics. The second one is the use of the renormalization group in the theory of critical phenomena and its statistical interpretation.

Jona-Lasinio, G.

231

Newer insulin analogs: advances in basal insulin replacement.  

Science.gov (United States)

Basal insulin analog therapy is the most common method of introducing insulin replacement therapy for the majority of patients with type 2 diabetes mellitus. Long-acting insulin analogs provide relatively peakless and more physiologic insulin replacement therapy than neutral protaminated Hagedorn insulin. Recently 2 new basal insulin analogs have been developed with superior pharmacokinetic and pharmacodynamics properties; insulin degludec and a pegylated insulin lispro. These agents are generally well tolerated and have been evaluated in both type 1 and type 2 diabetes. In this article we review the results of clinical trials assessing the efficacy, safety and tolerability of these newer longer-acting insulin analogs. In general rates of hypoglycaemia in these trials were low, glucose control was comparable to currently available basal insulin analogs, and rates of nocturnal hypoglycaemia were significantly and substantially lower. While further study will be required, advances in basal insulin replacement may offer important advantages over existing options for starting insulin strategies. PMID:23448197

Zinman, Bernard

2013-03-01

232

Glucose uptake and metabolism by red blood cells from fish with different extracellular glucose levels.  

Science.gov (United States)

The aim of the present study was to assess whether mechanisms of glucose trafficking by red blood cells (RBCs) relate to species-specific extracellular glucose levels. Atlantic cod (Gadus morhua), Atlantic salmon (Salmo salar), cunner (Tautogolabrus adspersus) and short-horned sculpin (Myoxocephalus scorpius) had plasma glucose levels of 4, 4.1, 1.95 and 0.73 mmol l(-1), respectively. Glucose uptake by isolated RBCs was measured by the initial incorporation of [6-(14)C]-glucose and steady-state glucose metabolism was determined by the production of (3)H(2)O from [2-(3)H]-glucose. Saturation kinetics of glucose uptake and inhibition of both glucose uptake and metabolism by cytochalasin B and phloretin revealed that Atlantic cod, cunner and sculpin RBCs all had a facilitated transport component to glucose trafficking. RBCs from Atlantic salmon showed a linear relationship between glucose uptake and extracellular glucose level, but exhibited clear inhibition of glucose metabolism by cytochalasin B and phloretin, suggesting a component of facilitated glucose transport that is more elusive to detect. The production of (3)H(2)O was linear for at least 6 h and as such presents a rigorous approach to measuring glycolytic rate. Steady-state rates of glucose metabolism were achieved at extracellular levels of approximately 1 mmol l(-1) glucose for RBCs from all species, showing that within-species normal extracellular glucose level is not a primary determinant of the basal level of glycolysis. At physiological levels of extracellular glucose, the ratio of initial glucose uptake to glucose metabolism was 1.5 to 4 for all RBCs, suggesting that there is scope to increase metabolic rate without alteration of the basal glucose uptake capacity. PMID:23038726

Driedzic, William R; Clow, Kathy A; Short, Connie E

2012-10-04

233

Paricalcitol does not improve glucose metabolism in patients with stage 3-4 chronic kidney disease.  

UK PubMed Central (United Kingdom)

Patients with chronic kidney disease are often insulin resistant and glucose intolerant--abnormalities that promote cardiovascular disease. Administration of 1,25-dihydroxyvitamin D (calcitriol) has improved glucose metabolism in patients with end-stage renal disease. We conducted a randomized, placebo-controlled clinical trial to test whether paricalcitol, a 1,25-dihydroxyvitamin D analog, changes glucose tolerance in earlier stages of chronic kidney disease. In a crossover design, 22 nondiabetic patients with estimated glomerular filtration rates of stage 3-4 chronic kidney disease and fasting plasma glucose of 100-125 mg/dl were given daily oral paricalcitol for 8 weeks and matching placebo for 8 weeks, separated by an 8-week washout period. The order of interventions was random and blinded to both participants and investigators. Paricalcitol significantly reduced serum concentrations of parathyroid hormone, 1,25-dihydroxyvitamin D, and 25-hydroxyvitamin D while significantly increasing serum concentrations of fibroblast growth factor-23 and 24,25-dihydroxyvitamin D. Paricalcitol, however, had no significant effect on glucose tolerance (the primary outcome measure), insulin sensitivity, beta-cell insulin response, plasma free fatty acid suppression, or urinary F2-isoprostane excretion. Thus, despite substantial effects on vitamin D metabolism, paricalcitol did not improve glucose metabolism in nondiabetic patients with stage 3-4 chronic kidney disease.

de Boer IH; Sachs M; Hoofnagle AN; Utzschneider KM; Kahn SE; Kestenbaum B; Himmelfarb J

2013-02-01

234

Paricalcitol does not improve glucose metabolism in patients with stage 3-4 chronic kidney disease.  

Science.gov (United States)

Patients with chronic kidney disease are often insulin resistant and glucose intolerant--abnormalities that promote cardiovascular disease. Administration of 1,25-dihydroxyvitamin D (calcitriol) has improved glucose metabolism in patients with end-stage renal disease. We conducted a randomized, placebo-controlled clinical trial to test whether paricalcitol, a 1,25-dihydroxyvitamin D analog, changes glucose tolerance in earlier stages of chronic kidney disease. In a crossover design, 22 nondiabetic patients with estimated glomerular filtration rates of stage 3-4 chronic kidney disease and fasting plasma glucose of 100-125 mg/dl were given daily oral paricalcitol for 8 weeks and matching placebo for 8 weeks, separated by an 8-week washout period. The order of interventions was random and blinded to both participants and investigators. Paricalcitol significantly reduced serum concentrations of parathyroid hormone, 1,25-dihydroxyvitamin D, and 25-hydroxyvitamin D while significantly increasing serum concentrations of fibroblast growth factor-23 and 24,25-dihydroxyvitamin D. Paricalcitol, however, had no significant effect on glucose tolerance (the primary outcome measure), insulin sensitivity, beta-cell insulin response, plasma free fatty acid suppression, or urinary F2-isoprostane excretion. Thus, despite substantial effects on vitamin D metabolism, paricalcitol did not improve glucose metabolism in nondiabetic patients with stage 3-4 chronic kidney disease. PMID:22913981

de Boer, Ian H; Sachs, Michael; Hoofnagle, Andrew N; Utzschneider, Kristina M; Kahn, Steven E; Kestenbaum, Bryan; Himmelfarb, Jonathan

2012-08-22

235

Effects of metoclopramide on duodenal motility and flow events, glucose absorption, and incretin hormone release in response to intraduodenal glucose infusion.  

Science.gov (United States)

The contribution of small intestinal motor activity to nutrient absorption is poorly defined. A reduction in duodenal flow events after hyoscine butylbromide, despite no change in pressure waves, was associated with reduced secretion of the incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) and a delay in glucose absorption. The aim of this study was to investigate the effect of metoclopramide on duodenal motility and flow events, incretin hormone secretion, and glucose absorption. Eight healthy volunteers (7 males and 1 female; age 29.8 ± 4.6 yr; body mass index 24.5 ± 0.9 kg/m²) were studied two times in randomized order. A combined manometry and impedance catheter was used to measure pressure waves and flow events in the same region of the duodenum simultaneously. Metoclopramide (10 mg) or control was administered intravenously as a bolus, followed by an intraduodenal glucose infusion for 60 min (3 kcal/min) incorporating the ¹?C-labeled glucose analog 3-O-methylglucose (3-OMG). We found that metoclopramide was associated with more duodenal pressure waves and propagated pressure sequences than control (P < 0.05 for both) during intraduodenal glucose infusion. However, the number of duodenal flow events, blood glucose concentration, and plasma 3-[¹?C]OMG activity did not differ between the two study days. Metoclopramide was associated with increased plasma concentrations of GLP-1 (P < 0.05) and GIP (P = 0.07) but lower plasma insulin concentrations (P < 0.05). We concluded that metoclopramide was associated with increased frequency of duodenal pressure waves but no change in duodenal flow events and glucose absorption. Furthermore, GLP-1 and GIP release increased with metoclopramide, but insulin release paradoxically decreased. PMID:20829521

Kuo, Paul; Bellon, Max; Wishart, Judith; Smout, André J; Holloway, Richard H; Fraser, Robert J L; Horowitz, Michael; Jones, Karen L; Rayner, Christopher K

2010-09-09

236

Effects of metoclopramide on duodenal motility and flow events, glucose absorption, and incretin hormone release in response to intraduodenal glucose infusion.  

UK PubMed Central (United Kingdom)

The contribution of small intestinal motor activity to nutrient absorption is poorly defined. A reduction in duodenal flow events after hyoscine butylbromide, despite no change in pressure waves, was associated with reduced secretion of the incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) and a delay in glucose absorption. The aim of this study was to investigate the effect of metoclopramide on duodenal motility and flow events, incretin hormone secretion, and glucose absorption. Eight healthy volunteers (7 males and 1 female; age 29.8 ± 4.6 yr; body mass index 24.5 ± 0.9 kg/m²) were studied two times in randomized order. A combined manometry and impedance catheter was used to measure pressure waves and flow events in the same region of the duodenum simultaneously. Metoclopramide (10 mg) or control was administered intravenously as a bolus, followed by an intraduodenal glucose infusion for 60 min (3 kcal/min) incorporating the ¹?C-labeled glucose analog 3-O-methylglucose (3-OMG). We found that metoclopramide was associated with more duodenal pressure waves and propagated pressure sequences than control (P < 0.05 for both) during intraduodenal glucose infusion. However, the number of duodenal flow events, blood glucose concentration, and plasma 3-[¹?C]OMG activity did not differ between the two study days. Metoclopramide was associated with increased plasma concentrations of GLP-1 (P < 0.05) and GIP (P = 0.07) but lower plasma insulin concentrations (P < 0.05). We concluded that metoclopramide was associated with increased frequency of duodenal pressure waves but no change in duodenal flow events and glucose absorption. Furthermore, GLP-1 and GIP release increased with metoclopramide, but insulin release paradoxically decreased.

Kuo P; Bellon M; Wishart J; Smout AJ; Holloway RH; Fraser RJ; Horowitz M; Jones KL; Rayner CK

2010-12-01

237

Detection of correct and incorrect measurements in real-time continuous glucose monitoring systems by applying a postprocessing support vector machine.  

Science.gov (United States)

Support vector machines (SVMs) are an attractive option for detecting correct and incorrect measurements in real-time continuous glucose monitoring systems (RTCGMSs), because their learning mechanism can introduce a postprocessing strategy for imbalanced datasets. The proposed SVM considers the geometric mean to obtain a more balanced performance between sensitivity and specificity. To test this approach, 23 critically ill patients receiving insulin therapy were monitored over 72 h using an RTCGMS, and a dataset of 537 samples, classified according to International Standards Organization (ISO) criteria (372 correct and 165 incorrect measurements), was obtained. The results obtained were promising for patients with septic shock or with sepsis, for which the proposed system can be considered as reliable. However, this approach cannot be considered suitable for patients without sepsis. PMID:23380841

Leal, Yenny; Gonzalez-Abril, Luis; Lorencio, Carol; Bondia, Jorge; Vehi, Josep

2013-02-01

238

Determination of plasma glucose during rapid glucose excursions with a subcutaneous glucose sensor.  

Science.gov (United States)

Continuous glucose monitoring has the potential to improve glucose management and reduce the risk of hypoglycemia in individuals with diabetes. Accurate sensors may also allow the development of a closed-loop insulin delivery system. The purpose of this work was to determine the delay time associated with a subcutaneous glucose sensor during rapidly changing glucose excursions. Subcutaneous glucose sensors (Medtronic MiniMed, Inc., Northridge, CA) were inserted in five healthy men. After a 2-h stabilization period, a 3-h hyperglycemic (approximately 11 mM) clamp was performed followed by a 90-min period in which plasma glucose was allowed to decline to as low as 2.8 mM. Sensors were calibrated using two points (basal and hyperglycemia), and the calibrated sensor glucose measurements were compared with those from a reference analyzer (Beckman Instruments, Fullerton, CA). Response time was estimated from a first-order kinetic model. Plasma glucose levels, determined with the subcutaneous sensor, were highly correlated with those obtained with the reference glucose analyzer (r(2) = 0.91, p closed-loop insulin delivery system to be developed based on the subcutaneous sensing site. PMID:12725704

Steil, Garry M; Rebrin, Kerstin; Mastrototaro, John; Bernaba, Basem; Saad, Mohammed F

2003-01-01

239

Continuous glucose monitoring in dogs and cats.  

UK PubMed Central (United Kingdom)

Use of continuous glucose monitoring in veterinary medicine is gaining popularity. Through use of a commercially available continuous glucose monitor system, insights into daily glucose changes in dogs and cats are achievable. The continuous glucose monitoring system measures glucose concentrations in the interstitial fluid of the subcutaneous space by use of a small, flexible probe. When placed in the subcutaneous tissue, the probe is connected to a recording device that is attached to the animal and records the interstitial fluid glucose concentration every 5 minutes (288 readings per 24 hours). Once attached and properly calibrated, the instrument can remain in place for several days, hospitalization of the patient is not necessary, and the normal daily routine of the animal can be maintained. The data from the recording device are then downloaded and a very detailed picture of the interstitial fluid glucose concentration over that time period can be obtained. Subcutaneous interstitial fluid glucose concentrations have a good correlation to blood glucose concentrations within a defined range. The continuous glucose monitoring system has distinct advantages over traditional blood glucose curves and is a valuable tool for managing diabetic dogs and cats. In addition, other clinical uses for continuous glucose monitoring are being developed. This review is designed to outline the technology behind the continuous glucose monitoring system, describe the clinical use of the instrument, provide clinical examples in which it may be useful, and discuss future directions for continuous glucose monitoring in dogs and cats.

Wiedmeyer CE; DeClue AE

2008-01-01

240

Continuous glucose monitoring in dogs and cats.  

Science.gov (United States)

Use of continuous glucose monitoring in veterinary medicine is gaining popularity. Through use of a commercially available continuous glucose monitor system, insights into daily glucose changes in dogs and cats are achievable. The continuous glucose monitoring system measures glucose concentrations in the interstitial fluid of the subcutaneous space by use of a small, flexible probe. When placed in the subcutaneous tissue, the probe is connected to a recording device that is attached to the animal and records the interstitial fluid glucose concentration every 5 minutes (288 readings per 24 hours). Once attached and properly calibrated, the instrument can remain in place for several days, hospitalization of the patient is not necessary, and the normal daily routine of the animal can be maintained. The data from the recording device are then downloaded and a very detailed picture of the interstitial fluid glucose concentration over that time period can be obtained. Subcutaneous interstitial fluid glucose concentrations have a good correlation to blood glucose concentrations within a defined range. The continuous glucose monitoring system has distinct advantages over traditional blood glucose curves and is a valuable tool for managing diabetic dogs and cats. In addition, other clinical uses for continuous glucose monitoring are being developed. This review is designed to outline the technology behind the continuous glucose monitoring system, describe the clinical use of the instrument, provide clinical examples in which it may be useful, and discuss future directions for continuous glucose monitoring in dogs and cats. PMID:18289283

Wiedmeyer, C E; DeClue, A E

 
 
 
 
241

A Fuzzy Model for Analogical Problem Solving  

CERN Document Server

In this paper we develop a fuzzy model for the description of the process of Analogical Reasoning by representing its main steps as fuzzy subsets of a set of linguistic labels characterizing the individuals' performance in each step and we use the Shannon- Wiener diversity index as a measure of the individuals' abilities in analogical problem solving. This model is compared with a stochastic model presented in author's earlier papers by introducing a finite Markov chain on the steps of the process of Analogical Reasoning. A classroom experiment is also presented to illustrate the use of our results in practice.

Voskoglou, Michael Gr

2012-01-01

242

Implantable glucose sensors for diabetes monitoring.  

UK PubMed Central (United Kingdom)

The development of glucose sensors for clinical use is driven by the aim of blood glucose normalization in diabetic patients, and the detection of blood glucose impairment in nondiabetic subjects submitted to critical conditions. Currently available devices for continuous glucose monitoring are either minimally invasive or partly implantable, and measure subcutaneous interstitial glucose using glucose-oxidase. The signal generated is calibrated against capillary blood glucose to provide estimated blood glucose values. The three certified glucose sensing systems for clinical use: GlucoWatch(R) biographer, CGMS(R) and GlucoDay(R) use different techniques for glucose recovery: reverse iontophoresis, direct subcutaneous implantation and microdialysis, respectively. These devices show sufficient accuracy to identify trends of blood glucose variations, but provide information either with significant delay (GlucoWatch(R)) or retrospectively after computerized analysis of "Holter-style" glucose recordings (CGMS(R), GlucoDay(R)). Only GlucoDay(R) can provide almost online data. Occasional use for short-term assessment of glucose control or educational purposes in diabetic subjects dominates the present clinical use of these devices. Because of the discrepancies between variations of blood and interstitial glucose levels, treatment adaptations from collected sensor data still need further assessment by capillary blood glucose measurements, while the limited biocompatibility of these systems allows only short-term recordings for a few days at most. Subcutaneous and intravenous, fully implantable, sensor models are currently under development and evaluated in clinical trials. Designed for long-term glucose sensing and permanent clinical use, these glucose sensors show promising early results in view of open-loop or closed-loop insulin delivery based upon a sensor signal.

Renard

2004-04-01

243

Implantable glucose sensors for diabetes monitoring.  

Science.gov (United States)

The development of glucose sensors for clinical use is driven by the aim of blood glucose normalization in diabetic patients, and the detection of blood glucose impairment in nondiabetic subjects submitted to critical conditions. Currently available devices for continuous glucose monitoring are either minimally invasive or partly implantable, and measure subcutaneous interstitial glucose using glucose-oxidase. The signal generated is calibrated against capillary blood glucose to provide estimated blood glucose values. The three certified glucose sensing systems for clinical use: GlucoWatch(R) biographer, CGMS(R) and GlucoDay(R) use different techniques for glucose recovery: reverse iontophoresis, direct subcutaneous implantation and microdialysis, respectively. These devices show sufficient accuracy to identify trends of blood glucose variations, but provide information either with significant delay (GlucoWatch(R)) or retrospectively after computerized analysis of "Holter-style" glucose recordings (CGMS(R), GlucoDay(R)). Only GlucoDay(R) can provide almost online data. Occasional use for short-term assessment of glucose control or educational purposes in diabetic subjects dominates the present clinical use of these devices. Because of the discrepancies between variations of blood and interstitial glucose levels, treatment adaptations from collected sensor data still need further assessment by capillary blood glucose measurements, while the limited biocompatibility of these systems allows only short-term recordings for a few days at most. Subcutaneous and intravenous, fully implantable, sensor models are currently under development and evaluated in clinical trials. Designed for long-term glucose sensing and permanent clinical use, these glucose sensors show promising early results in view of open-loop or closed-loop insulin delivery based upon a sensor signal. PMID:16754492

Renard

2004-04-01

244

Analog and digital; Analog to digital  

Energy Technology Data Exchange (ETDEWEB)

The Economic Council has recently announced an economic program targeted at around 2010, pointing out that there will be a drastic transition from the age of modern industrialization to an age of wisdom and putting a stress on the importance of individuality and creativity. The brains consist of the left-brain and the right-brain. The left-brain governs knowledge and logic, the right-brain imagination, creative power, and inspiration. The digital computer has shown up. It is high in capacity and speed, and deals with quantities of data at once, and has wiped out the analog computer. The author does not mean to deny the modern convenience, but fears that people are growing more dependent on the tool, so much so that they are forgetting the use of their brains. For an engineer, the state in which his right-brain is in action is a state in which he is creative and full of inspiration discharging his tasks on the strength of his rich stock of analogous reasoning. Engineering is what one is to acquire only by using one's hands and feet, producing much perspiration. Too much dependence on knowledge and tool will but lead to the depletion of engineering capabilities. The author wants engineers to activate their right-brains and exhibit their creativity. (NEDO)

Inoue, H. [Mazda Motor Corp., Hiroshima (Japan)

1999-11-01

245

Primer on pramlintide, an amylin analog.  

UK PubMed Central (United Kingdom)

PURPOSE: Pramlintide is an injectable synthetic analog of human amylin. It is indicated for patients with type 1 or type 2 diabetes who are taking mealtime insulin but have been unable to achieve desired glucose targets. Pramlintide decreases postprandial glucose by lowering inappropriate postmeal glucagon secretion, slowing gastric emptying, and increasing satiety. As such, pramlintide targets several of the defects commonly seen in patients with diabetes. Given the unique characteristics of this agent in the treatment of diabetes, a practical guide to its use is presented. CONCLUSION: Pramlintide treats diabetes with a novel mechanism of action, offering the potential for improved postprandial control and weight loss for patients with type 1 or type 2 diabetes. Providers and diabetes educators should be familiar with the utility of the medication as well as its potential limitations in order to fully educate patients and maximize treatment options for patients with diabetes.

Traina AN; Kane MP

2011-05-01

246

Fluorescence intensity- and lifetime-based glucose sensing using glucose/galactose-binding protein.  

UK PubMed Central (United Kingdom)

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

Pickup JC; Khan F; Zhi ZL; Coulter J; Birch DJ

2013-01-01

247

[Discrepancy between IGF-1 and GH during 75 g oral glucose tolerance test measures to acromegaly screening in a patient with macroprolactinoma--case report and literature review].  

UK PubMed Central (United Kingdom)

We describe a patient with macroprolactinoma and discrepant insulin-like growth factor (IGF-1) concentration (elevated) and growth hormone (GH) values during a 75 g oral glucose tolerance test (normal), that were measured to evaluate the co-secretion of GH by tumor. With the bromocriptin use, the patient achieved normalization of prolactin, but persisted with high levels of IGF1, suggesting to be subclinical acromegaly. After the development of new more sensitive GH assays, cases of discrepant GH and IGF-1 results have been observed and taken to some authors to suggest that GH nadir concentration during 75 g OGTT used to acromegaly diagnosis and treatment could be lower than values considered currently normal. Thus, if this is confirmed, subclinical and oligosymptomatic acromegaly cases could have earlier diagnoses.

Gonçalves FT; Feibelmann TC; Fernandes ML; Fonseca AR; Arantes HP; Jorge PT

2007-04-01

248

Implantable continuous glucose sensors.  

Science.gov (United States)

Because of the limits of wearable needle-type or microdialysis-based enzymatic sensors in clinical use, fully implantable glucose monitoring systems (IGMS) represent a promising alternative. Long-term use reducing impact of invasiveness due to implantation, less frequent calibration needs because of a more stable tissue environment around the sensor and potential easier inclusion in a closed-loop insulin delivery system are the expected benefits of IGMS. First experiences with subcutaneous and intravenous IGMS have been recently collected in pilot studies. While no severe adverse events have been reported, biointerface issues have been responsible for the failures of IGMS. Tissue reactions around implanted subcutaneous devices and damages of intravenous sensors due to shearing forces of blood flow impaired IGMS function and longevity. In functioning systems, accuracy of glucose measurement reached satisfactory levels for average durations of about 120 days with subcutaneous IGMS and 259 days with intravenous sensors. Moreover, sensor information could help to improve time spent in normal glucose range when provided to patients wearing subcutaneous IGMS and allowed safe and effective closed-loop glucose control when intravenous sensors were connected to implanted pumps using intra-peritoneal insulin delivery. These data could open a favourable perspective for IGMS after improvement of biointerface conditions and if compatible with an affordable cost. PMID:18690897

Renard, Eric

2008-08-01

249

Implantable continuous glucose sensors.  

UK PubMed Central (United Kingdom)

Because of the limits of wearable needle-type or microdialysis-based enzymatic sensors in clinical use, fully implantable glucose monitoring systems (IGMS) represent a promising alternative. Long-term use reducing impact of invasiveness due to implantation, less frequent calibration needs because of a more stable tissue environment around the sensor and potential easier inclusion in a closed-loop insulin delivery system are the expected benefits of IGMS. First experiences with subcutaneous and intravenous IGMS have been recently collected in pilot studies. While no severe adverse events have been reported, biointerface issues have been responsible for the failures of IGMS. Tissue reactions around implanted subcutaneous devices and damages of intravenous sensors due to shearing forces of blood flow impaired IGMS function and longevity. In functioning systems, accuracy of glucose measurement reached satisfactory levels for average durations of about 120 days with subcutaneous IGMS and 259 days with intravenous sensors. Moreover, sensor information could help to improve time spent in normal glucose range when provided to patients wearing subcutaneous IGMS and allowed safe and effective closed-loop glucose control when intravenous sensors were connected to implanted pumps using intra-peritoneal insulin delivery. These data could open a favourable perspective for IGMS after improvement of biointerface conditions and if compatible with an affordable cost.

Renard E

2008-08-01

250

Glucose monitoring at the thenar: evaluation of upper dermal blood glucose kinetics during rapid systemic blood glucose changes.  

UK PubMed Central (United Kingdom)

OBJECTIVE: We compared blood glucose measurements at the thenar with those at the fingertip during glucose increase and decrease that was rapid enough to induce glucose differences between the forearm and the fingertip. METHODS: A rapid glucose increase was induced by oral glucose; subsequently, a rapid glucose decrease was induced by intravenous insulin in 16 insulin-treated patients with diabetes. Capillary samples were taken in parallel from the thenar and fingertip. Different glucose monitors (FreeStyle, OneTouch Ultra, Soft-Sense) were used. Additional samples were taken from the forearm (n = 10 patients) in order to demonstrate that the blood glucose change achieved was rapid enough to principally induce glucose differences at alternative sites. RESULTS: Neither blood glucose at baseline (135 +/- 34 vs. 136 +/- 41 mg/dl, p = 0.86) nor glucose amplitude during increase (190 +/- 35 vs. 188 +/- 41 mg/dl, p = 0.65) or decrease (255 +/- 32 vs. 257 +/- 45 mg/dl, p = 0.83) differed significantly between the fingertip and the thenar. Intra-individual average thenar-fingertip glucose difference was - 2 +/- 12 (p = 1.00) and + 5 +/- 9 mg/dl (p = 0.11). In the subgroup, intra-individual average forearm-finger difference was - 50 +/- 19 (p < 0.01) and + 45 +/- 11 mg/dl (p < 0.01) during glucose-increase and decrease, respectively. There were no obvious device-specific differences. CONCLUSIONS: Blood glucose measurements at the thenar are a safe alternative to measurements at the fingertip at steady state as well as during blood glucose change that is sufficiently rapid to induce clinically relevant differences between forearm and fingertip.

Jungheim K; Koschinsky T

2002-06-01

251

Analogs for transuranic elements  

International Nuclear Information System (INIS)

A combined theoretical and experimental approach is being used to estimate the long-term environmental and biogeochemical behaviors of selected transuranic elements. The objective of this research is to estimate the effect that long-term (hundreds of years) environmental weathering has on the behavior of the transuranic elements americium and curium. This is achieved by investigating the actual behavior of naturally occurring rare earth elements, especially neodymium, that serve as transuranic analogs. Determination of the analog element behavior provides data that can be used to estimate the ultimate availability to man of transuranic materials released into the environment

1981-01-01

252

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).

1991-01-01

253

Accuracy of different methods for blood glucose measurement in critically ill patients/ Acurácia de diferentes métodos para mensuração de glicemia em pacientes graves  

Scientific Electronic Library Online (English)

Full Text Available Abstract in portuguese CONTEXTO E OBJETIVO: Apesar de glicosímetros não serem validados para unidades de terapia intensiva (UTI), seu uso é corriqueiro. O objetivo foi avaliar a acurácia e concordância clínica entre a glicemia arterial por colorimetria (glicA-lab), glicemias capilar (glicC-fita) e arterial (glicA-fita) por glicosimetria, e venosa central por colorimetria (glicV-lab). TIPO DE ESTUDO E LOCAL: Estudo transversal realizado em hospital universitário. MÉTODO: Foram incluídos (more) 40 pacientes com choque séptico e indivíduos estáveis, sem infecção. A correlação entre medidas foi avaliada tanto na amostra global quanto nos subgrupos em uso de noradrenalina e com sinais de hipoperfusão tecidual. RESULTADOS: A glicC-fita mostrou pior correlação (r = 0,8289) e concordância (-9,87 ± 31,76). Esta superou os limites aceitáveis de variação do Clinical and Laboratory Standards Institute em 23,7% dos casos, sendo maior que a glicA-lab em 90% das vezes. A glicA-fita teve a melhor correlação (r = 0,9406), com concordância de -6,75 ± 19,07 e variação significativa em 7,9%. Para a glicV-lab, obteve-se r = 0,8549, concordância de -4,20 ± 28,37 e variação significativa em 15,7%. Variação significativa foi mais frequente em pacientes com noradrenalina (36,4% versus 6,3%, P = 0,03), mas não nos com hipoperfusão. Houve discordância de conduta clínica em 25%, 22,5% e 15% dos casos para glicC-fita, glicV-lab e glicA-fita, respectivamente. CONCLUSÃO: O uso de glicC-fita deveria ser evitado, principalmente se há uso de noradrenalina. Geralmente, este método superestima a glicemia real e acarreta erros de conduta. REGISTRO DO ENSAIO CLÍNICO: ACTRN12608000513314 (registrado como estudo observacional transversal). Abstract in english CONTEXT AND OBJECTIVE: Although glucometers have not been validated for intensive care units, they are regularly used. The aim of this study was to compare and assess the accuracy and clinical agreement of arterial glucose concentration obtained using colorimetry (Agluc-lab), capillary (Cgluc-strip) and arterial (Agluc-strip) glucose concentration obtained using glucometry and central venous glucose concentration obtained using colorimetry (Vgluc-lab). DESIGN AND SETTING: (more) Cross-sectional study in a university hospital. METHOD: Forty patients with septic shock and stable individuals without infection were included. The correlations between measurements were assessed both in the full sample and in subgroups using noradrenalin and presenting signs of tissue hypoperfusion. RESULTS: Cgluc-strip showed the poorest correlation (r = 0.8289) and agreement (-9.87 ± 31.76). It exceeded the limits of acceptable variation of the Clinical and Laboratory Standards Institute in 23.7% of the cases, and was higher than Agluc-lab in 90% of the measurements. Agluc-strip showed the best correlation (r = 0.9406), with agreement of -6.75 ± 19.07 and significant variation in 7.9%. For Vgluc-lab, r = 0.8549, with agreement of -4.20 ± 28.37 and significant variation in 15.7%. Significant variation was more frequent in patients on noradrenalin (36.4% versus 6.3%; P = 0.03) but not in the subgroup with hypoperfusion. There was discordance regarding clinical management in 25%, 22% and 15% of the cases for Cgluc-strip, Vgluc-lab and Agluc-strip, respectively. CONCLUSION: Cgluc-strip should be avoided, particularly if noradrenalin is being used. This method usually overestimates the true glucose levels and gives rise to management errors. CLINICAL TRIAL REGISTRATION: ACTRN12608000513314 (registered as an observational, cross-sectional study).

Pulzi Júnior, Sérgio Antônio; Assunção, Murillo Santucci Cesar de; Mazza, Bruno Franco; Fernandes, Haggéas da Silveira; Jackiu, Mirian; Freitas, Flávio Geraldo Resende; Machado, Flávia Ribeiro

2009-09-01

254

How Analogy Drives Physics  

Energy Technology Data Exchange (ETDEWEB)

Many new ideas in theoretical physics come from analogies to older ideas in physics. For instance, the abstract notion of 'isospin' (or isotopic spin) originated in the prior concept of 'spin' (quantized angular momentum); likewise, the concept of 'phonon' (quantum of sound, or quantized collective excitation of a crystal) was based on the prior concept of 'photon' (quantum of light, or quantized element of the electromagnetic field). But these two examples, far from being exceptions, in fact represent the bread and butter of inventive thinking in physics. In a nutshell, intraphysics analogy-making -- borrowing by analogy with something already known in another area of physics -- is central to the progress of physics. The aim of this talk is to reveal the pervasiveness -- indeed, the indispensability -- of this kind of semi-irrational, wholly intuitive type of thinking (as opposed to more deductive mathematical inference) in the mental activity known as 'doing physics'. Speculations as to why wild analogical leaps are so crucial to the act of discovery in physics (as opposed to other disciplines) will be offered.

Hofstadter, Doug (Indiana University)

2004-05-05

255

Thermomagnetic Analog Recording.  

Science.gov (United States)

The thermomagnetic recording of an analog signal on a CrO2 magnetic tape using a conventional magnetic head and a laser beam as a heating source, is discussed. It was concluded from experimental results that the method can be used for fairly high density ...

T. Nomura K. Yokoyama

1973-01-01

256

Biological evaluation of two iodine-123-labeled D-glucose acetals prepared as glucose transporter radioligands  

Energy Technology Data Exchange (ETDEWEB)

Two iodinated acetals of D-glucose, 4,6-(R)-O-(2'-iodoethylidene)-{alpha}, {beta}-D-glucose and 4,6-(R)-O-(4'-iodobenzylidene)-{alpha}, {beta}-D-glucose , were prepared and their potential as suitable SPECT radioligands for imaging of glucose transporters was studied. Both are analogs of acetal D-glucose derivatives, which are known to bind to the exofacial sites of the glucose transport protein (GluT). To assess whether iodinated acetals 1 and 2 interacted with the glucose transporter, they were tested in vitro in human erythrocytes (GluT1) and neonatal rat cardiomyocytes (GluT4). The results indicated that 1 and 2 had a very low affinity for the glucose transporter and probably accumulated in cells. Study of their tissue distribution was carried out in the mouse in vivo: Both compounds showed fast tissue clearance with preferential renal elimination. It is concluded that iodinated acetals of D-glucose 1 and 2 are not suitable for GluT targeting in vivo.

Brunet-Desruet, Marie-Dominique; Ghezzi, Catherine; Morin, Christophe; Comet, Michel; Fagret, Daniel

1998-07-01

257

Biological evaluation of two iodine-123-labeled D-glucose acetals prepared as glucose transporter radioligands  

International Nuclear Information System (INIS)

Two iodinated acetals of D-glucose, 4,6-(R)-O-(2'-iodoethylidene)-?, ?-D-glucose and 4,6-(R)-O-(4'-iodobenzylidene)-?, ?-D-glucose , were prepared and their potential as suitable SPECT radioligands for imaging of glucose transporters was studied. Both are analogs of acetal D-glucose derivatives, which are known to bind to the exofacial sites of the glucose transport protein (GluT). To assess whether iodinated acetals 1 and 2 interacted with the glucose transporter, they were tested in vitro in human erythrocytes (GluT1) and neonatal rat cardiomyocytes (GluT4). The results indicated that 1 and 2 had a very low affinity for the glucose transporter and probably accumulated in cells. Study of their tissue distribution was carried out in the mouse in vivo: Both compounds showed fast tissue clearance with preferential renal elimination. It is concluded that iodinated acetals of D-glucose 1 and 2 are not suitable for GluT targeting in vivo

1998-01-01

258

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  

International Nuclear Information System (INIS)

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

2010-01-01

259

Glucose intolerance in alcoholism.  

UK PubMed Central (United Kingdom)

Intravenous glucose tolerance tests were given to 31 nondiabetic alcoholics and 11 healthy nonalcoholic controls. In almost half of the alcoholics peak glucose concentration was higher and glucose elimination from the plasma was slower than in the controls.

Sereny G; Endrenyi L; Devenyi P

1975-03-01

260

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

DEFF Research Database (Denmark)

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.

Hansen, Torben; Drivsholm, Thomas

2007-01-01

 
 
 
 
261

Determination of plasma glucose during rapid glucose excursions with a subcutaneous glucose sensor.  

UK PubMed Central (United Kingdom)

Continuous glucose monitoring has the potential to improve glucose management and reduce the risk of hypoglycemia in individuals with diabetes. Accurate sensors may also allow the development of a closed-loop insulin delivery system. The purpose of this work was to determine the delay time associated with a subcutaneous glucose sensor during rapidly changing glucose excursions. Subcutaneous glucose sensors (Medtronic MiniMed, Inc., Northridge, CA) were inserted in five healthy men. After a 2-h stabilization period, a 3-h hyperglycemic (approximately 11 mM) clamp was performed followed by a 90-min period in which plasma glucose was allowed to decline to as low as 2.8 mM. Sensors were calibrated using two points (basal and hyperglycemia), and the calibrated sensor glucose measurements were compared with those from a reference analyzer (Beckman Instruments, Fullerton, CA). Response time was estimated from a first-order kinetic model. Plasma glucose levels, determined with the subcutaneous sensor, were highly correlated with those obtained with the reference glucose analyzer (r(2) = 0.91, p < 0.001; mean absolute difference of approximately 8%). The half-time for the sensor response was estimated to be 4.0 +/- 1.0 min. The subcutaneous glucose sensor has the potential to facilitate the detection of hypoglycemia and improve overall glycemic control when used in a real-time monitor. The rapid response should be sufficient to allow a fully automated closed-loop insulin delivery system to be developed based on the subcutaneous sensing site.

Steil GM; Rebrin K; Mastrototaro J; Bernaba B; Saad MF

2003-01-01

262

Development of novel methods to determine crystalline glucose content of honey based on DSC, HPLC, and Viscosity measurements, and their use to examine the setting propensity of honey.  

UK PubMed Central (United Kingdom)

Crystallization must occur in honey in order to produce set or creamed honey; however, the process must occur in a controlled manner in order to obtain an acceptable product. As a consequence, reliable methods are needed to measure the crystal content of honey (? expressed as kg crystal per kg honey), which can also be implemented with relative ease in industrial production facilities. Unfortunately, suitable methods do not currently exist. This article reports on the development of 2 independent offline methods to measure the crystal content in honey based on differential scanning calorimetry and high-performance liquid chromatography. The 2 methods gave highly consistent results on the basis of paired t-test involving 143 experimental points (P > 0.05, r2 = 0.99). The crystal content also correlated with the relative viscosity, defined as the ratio of the viscosity of crystal containing honey to that of the same honey when all crystals are dissolved, giving the following correlation: ?r=1-1398.8?2.318. This correlation can be used to estimate the crystal content of honey in industrial production facilities. The crystal growth rate at a temperature of 14 °C-the normal crystallization temperature used in practice-was linear, and the growth rate also increased with the total glucose content in the honey.

Al-Habsi NA; Davis FJ; Niranjan K

2013-06-01

263

Topographical analysis of glucose metabolism, as measured with positron emission tomography, in dementia of the Alzheimer type: use of linear histograms.  

UK PubMed Central (United Kingdom)

A linear histogram method was employed to analyze brain images of glucose uptake obtained by positron emission tomography in patients with dementia of the Alzheimer type and in control subjects. A line was drawn by computer which traversed the image of a brain slice taken at 70 mm above and parallel to the inferior orbitomeatal line, and rCMRglc was plotted as a function of distance along this line in 3 brain areas: frontal, sensorimotor and parietal. Peak rCMRglc values were significantly decreased in moderately-to-severely demented patients relative to healthy age-matched controls, but not in mildly demented patients. Furthermore, both the mildly and the more severely demented patients differed from controls in having reduced ratios of parietal association to sensorimotor peak rCMRglc. The variances of right-left metabolic asymmetries did not differ significantly between Alzheimer patients and controls. Severity of dementia, as evaluated by scores on the Mini-Mental State Examination, correlated with ratios of peak rCMRglc in frontal and parietal cortex to that in sensorimotor cortex. These results indicate that measures of focal peak rCMRglc do not discriminate between mildly demented patients and controls, whereas focal ratios of rCMRglc, where the denominator corresponds to rCMRglc from a relatively spared region, provide useful measures of metabolic dysfunction in the early stages of Alzheimer's disease.

McNamara D; Horwitz B; Grady CL; Rapoport SI

1987-09-01

264

Cerebral muscarinic acetylcholinergic receptor measurement in Alzheimer's disease patients on 11C-N-methyl-4-piperidyl benzilate. Comparison with cerebral blood flow and cerebral glucose metabolism  

International Nuclear Information System (INIS)

We studied the cerebral muscarinic acetylcholinergic receptor (mACh-R) by means of 11C-N-methyl-4-piperidyl benzilate (11C-NMPB) and positron emission tomography (PET) in Alzheimer''s disease (AD) cases, and the findings were compared with the cerebral blood flow (CBF) and the glucose metabolism (CMRGlc) to evaluate the relationship between the mACh-R and the CBF or the CMRGlc. The subjects consisted of 18 patients with AD and 18 age and sex matched normal volunteers. The patients were clinically diagnosed according to the criteria of the NINDS-ADRDA as having ''''probable AD'''' and were thus classified into two groups (mild and moderate AD) according to the severity of dementia determined by DSM-III-R. The CBF was measured by 99mTc-HMPAO SPECT, and the CMRGlc was measured by 18FDG PET. The 11C-NMPB uptake was evaluated by the graphical method and the ratio method (ROIs/Cerebellum). A significant mACh-R decrease and more severe CMRGlc decrease in the cortical region was seen in mild and moderate AD. The decrease in the CBF was not as obvious as that in the mACh-R and the CMRGlc. Our study thus suggested that the mACh-R decreased in patients with AD, and that the 18FDG PET was the most sensitive method for detecting the degenerative regions in patients with AD. (author)

1998-01-01

265

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)

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.

Wagner Bandeira Andriola

2000-01-01

266

Analog storage integrated circuit  

Energy Technology Data Exchange (ETDEWEB)

A high speed data storage array is defined utilizing a unique cell design for high speed sampling of a rapidly changing signal. Each cell of the array includes two input gates between the signal input and a storage capacitor. The gates are controlled by a high speed row clock and low speed column clock so that the instantaneous analog value of the signal is only sampled and stored by each cell on coincidence of the two clocks.

Walker, J. T. (Palo Alto, CA); Larsen, R. S. (Menlo Park, CA); Shapiro, S. L. (Palo Alto, CA)

1989-01-01

267

Electronic Computers and Analog Devices.  

Science.gov (United States)

The handbook presents a classification of electronic and analog computers and analog devices, including descriptions, basic technical features and fields of application of domestically-manufactured universal digital computers, digital control devices, dig...

V. I. Grubov V. S. Kirdan

1971-01-01

268

Superconducting analog-to-digital converters. Final report  

Energy Technology Data Exchange (ETDEWEB)

The contents include: superconducting analog-to-digital converter work at MITRE; development of a rapidly tunable microwave source; design and evaluation of a Josephson array oscillator; obtaining high-accuracy measurements from low-accuracy measurements; superconducting microwave transmission lines; high performance, superconducting analog-to-digital converter; edge sharpening with Josephson Junction; design evaluation of a subranging superconducting analog-to-digital converter; feasibility study of a superconducting sigma-delta analog-to-digital converter, and VHDL simulation study of superconducting sigma delta modulators.

Schoen, J.M.

1991-09-01

269

FASTBUS 16-channel 8-bit analog-to-digital converter  

International Nuclear Information System (INIS)

A FASTBUS 16-channel 8-bit analog-to-digital converter is described. The module is made on the basis of an ultrafast integrated analog-to-digital converter (flash ADC K1107PV3). The range of the measured analog signals is ±2 V. An analog signal is converted to the digital code lineraly. Information from the ADC is read out via a FASTBUS dataway from two channels simultaneously during ? 40 ns. The 16-channel ADC is used in the system for measuring the characteristics from the scintillation hodoscopes of the spectrometer SPHERE

1988-01-01

270

Effect of glucose stimulation on /sup 45/calcium uptake of rat pancreatic islets and their total calcium content as measured by a fluorometric micro-method  

Energy Technology Data Exchange (ETDEWEB)

Glucose-stimulated /sup 45/calcium uptake and total calcium content of rat pancreatic islets has been studied, using a new fluorometric micro-method to estimate total calcium. Extracellular calcium was separated from incubated tissue by a rapid micro-filtration procedure. Islets incubated up to 60 min with calcium chloride 2.5 mmol/l and glucose 2.5 mmol/l maintained the same calcium content (670 +- 7.5 pmol/..mu..g DNA). When the glucose concentration was raised to 15 mmol/l no change in the total calcium content could be detected. On incubation with glucose 2.5 mmol/l in the absence of calcium, the calcium content decreased to 488 +- 27 pmol/..mu..g DNA. On incubation with /sup 45/calcium chloride 2.5 mmol/l for 5 or 30 min at 2.5 mmol/l glucose, islets exchanged 21 +- 2 and 28 +- 1% of their total calcium content and, at 15 mmol/l glucose, 30 +- 3 and 45 +- 2%, respectively. Thus, islet calcium has a high turn-over rate. Glucose stimulation results in an increase of the calcium uptake without enhancing the total calcium content and hence must increase the calcium-exchangeable pool.

Wolters, G.H.J.; Wiegman, J.B.; Konijnendijk, W.

1982-02-01

271

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)

Full Text Available Abstract in portuguese 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 f (more) oram 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 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). (more) 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.

Andriola, Wagner Bandeira

2000-01-01

272

Regulation of glucose metabolism in Thiobacillus intermedius.  

UK PubMed Central (United Kingdom)

Glucose-yeast extract or glucose-casein hydrolysate-grown Thiobacillus intermedius cells, which use glucose for energy generation, possess high specific activities of the Entner-Doudoroff pathway and related enzymes, 6-phosphogluconate dehydrase, 2-keto-3-deoxy-6-phosphogluconate aldolase, glucokinase, and glucose-6-phosphate dehydrogenase, but low activities of enzymes unique to the pentose shunt and Embden-Meyerhof pathways. Although the synthesis of the latter enzymes remains largely unaffected by the growth environment, that of the former is stimulated by glucose. Radiorespirometric measurements demonstrate an early and parallel respiration of glucose carbon atoms one and four in glucose-casein hydrolysate broth. It is concluded that the Entner-Doudoroff pathway performs an energetic role in glucose metabolism by T. intermedius with the pentose shunt and Embden-Meyerhof pathways functioning mainly in biosynthesis. The presence of thiosulfate in the growth medium inhibits the synthesis of the Entner-Doudoroff pathway and related enzymes. In addition, both thiosulfate and glucose inhibit the synthesis of the Krebs cycle enzymes, nicotinamide adenine dinucleotide phosphate-linked isocitrate and alpha-ketoglutarate dehydrogenases. Thus, repression of enzymes is of significance in the adaptation of T. intermedius to its nutritional environment. The activity of glucose-6-phosphate dehydrogenase of T. intermedius is inhibited by adenosine triphosphate. Such a control could afford the organism a mechanism to regulate the flow of glucose into major energetic and biosynthetic routes.

Matin A; Rittenberg SC

1970-10-01

273

Evidence for the presence of glucose cycling in pancreatic islets of the ob/ob mouse  

International Nuclear Information System (INIS)

[en] Pancreatic islets from ob/ob mice incubated with 3H2O and 5.5 mM glucose formed 3H-labeled glucose, 74 picoatoms incorporated/islet/h. Sixty-three percent of the 3H was bound to carbon 2 of the glucose. The amount of glucose-6-P dephosphorylated to glucose, determined from this incorporation, was 48 pmol/islet/h. Glucose utilization, measured by the formation of 3H2O from [5-3H]glucose, was 72 pmol/islet/h. The amount of glucose dephosphorylated was then about 40% of that phosphorylated. Thus, glucose-6-P is dephosphorylated to glucose to a significant extent by intact islets in vitro and presumably by the beta cells of the islets. The extent of this glucose cycling, i.e. glucose----glucose-6-P----glucose, may play a role in determining the extent of glucose-induced insulin secretion

1989-06-15

274

Postprandial glucose response to selected tropical fruits in normal glucose-tolerant Nigerians.  

UK PubMed Central (United Kingdom)

UNLABELLED: BaCKGROUND AND OBJECTIVES: The glycemic response to commonly eaten fruits in Nigeria has not been reported. Therefore, this study assessed the plasma glucose response to selected fruits in Nigeria. PATIENTS AND METHODS: Ten normal glucose-tolerant subjects randomly consumed 50 g carbohydrate portions of three fruits: banana (Musa paradisiaca), pineapple (Ananus comosus), and pawpaw (Carica papaya), and a 50-g glucose load at 1-week intervals. Blood samples were collected in the fasting state and half-hourly over a 2-h period post-ingestion of the fruits or glucose. The samples were analyzed for plasma glucose concentrations. Plasma glucose responses were assessed by the peak plasma glucose concentration, maximum increase in plasma glucose, 2-h postprandial plasma glucose level, and incremental area under the glucose curve and glycemic index (GI). RESULTS: The results showed that the blood glucose response to these three fruits was similar in terms of their incremental areas under the glucose curve, maximum increase in plasma glucose, and glycemic indices (GIs). The 2-h postprandial plasma glucose level of banana was significantly higher than that of pineapple, P < 0.025. The mean ± SEM GI values were as follows: pawpaw; 86 ± 26.8%; banana, 75.1 ± 21.8%; pineapple, 64.5 ± 11.3%. The GI of glucose is taken as 100. The GI of pineapple was significantly lower than that of glucose (P < 0.05). CONCLUSION: Banana, pawpaw, and pineapple produced a similar postprandial glucose response. Measured portions of these fruits may be used as fruit exchanges with pineapple having the most favorable glycemic response.

Edo A; Eregie A; Adediran O; Ohwovoriole A; Ebengho S

2011-01-01

275

Discrete Calculus by Analogy  

CERN Multimedia

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

Izadi, F A; Bagirov, G

2009-01-01

276

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).

1976-01-01

277

Comb Filters with Analog Shift Registers BCCD  

Directory of Open Access Journals (Sweden)

Full Text Available This contribution deals with the concept and circumferential structure of comb filter for video signal processing. The comb filter was implemented by means of an analog shift register CCD (BCCD). The main conclusions, including the measured frequency response characteristic and time responses of the necessary control signals, are presented. This problem has been investigated as part of the GACR project.

V. Ricny; V. Novotny

1995-01-01

278

Starting insulin therapy with basal insulin analog or premix insulin analog in T2DM: a pooled analysis of treat-to-target trials.  

UK PubMed Central (United Kingdom)

OBJECTIVE: Although the choice of starting insulin for people with type 2 diabetes mellitus (T2DM) is often a basal or premix insulin analog, there is little evidence to base this decision on. This analysis aimed to determine if measurable clinical characteristics prior to starting insulin could predict differences in improved glycemic control between these options. RESEARCH DESIGN AND METHODS: A thorough literature search was performed for treat-to-target studies in insulin-naïve individuals with T2DM treated with biphasic insulin aspart (BIAsp 30), a basal insulin analog (insulin glargine or insulin detemir) or NPH insulin regimens once or twice daily plus oral glucose-lowering drugs (OGLDs). Patient data were pooled and mean baseline age, diabetes duration, gender, body mass index (BMI), HbA(1c), fasting plasma glucose (FPG), average postprandial plasma glucose over three meals (PPG) and bedtime PG were investigated for prediction of improved HbA(1c), FPG or PPG. Statistical analyses employed a linear mixed model with insulin type, OGLD, time and time-squared as fixed effects and patient and trial as random effects. RESULTS: Baseline age (p = 0.022) and bedtime PG (p = 0.036) were inter-related predictors of HbA(1c). In older individuals with higher bedtime PG, BIAsp 30 appeared to be more beneficial. In contrast, basal insulin appeared to be a better choice in younger individuals with lower bedtime PG. For FPG, BMI (p = 0.011) and post-breakfast PG (p = 0.042) were identified as predictors. Basal insulin appeared to achieve better FPG in patients with lower BMI and higher post-breakfast PG, while BIAsp 30 appeared to be better in patients with higher BMI and lower post-breakfast PG. Age (p = 0.0347) was the only baseline characteristic associated with differences in average PPG: mean PPG was similar between regimens in younger people, but BIAsp 30 achieved better PPG results in older persons. Minor hypoglycemia was reported by 56% of BIAsp 30- and 45% of basal-treated individuals. The major limitation of the study was that only Novo Nordisk trials were included in the analysis as access to individual patient data was required. As the trials were fairly heterogeneous a strict methodology was used to minimize potential confounding factors. CONCLUSIONS: Premix analog rather than basal insulin may be an appropriate choice to target HbA(1c) values in older individuals and those with higher bedtime PG, while basal insulin may be more appropriate to target FPG in patients with lower BMI and higher post-breakfast PG.

Fonseca V; Davidson J; Home P; Snyder J; Jellinger P; Dyhr Toft A; Barnett A

2010-07-01

279

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)

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

Glintborg, D.; Frystyk, J.

2008-01-01

280

Characterization of analog local cluster neural network hardware for control.  

UK PubMed Central (United Kingdom)

The local cluster neural network (LCNN) was designed for analog realization especially suited to applications in control systems. It uses clusters of sigmoidal neurons to generate basis functions that are localized in multidimensional input space. Sigmoidal neurons are well suited to analog electronic realization. In this paper, we report the results of extensive measurements that characterize the computational capabilities of the first analog very large scale integration (VLSI) realization of the LCNN. Despite manufacturing fluctuations and the inherent low precision of analog electronics, the test results suggest that it may be suitable for use in feedback control systems.

Sitte J; Zhang L; Rueckert U

2007-07-01

 
 
 
 
281

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)

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.

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

2012-01-01

282

2-deoxy-glucose-6-phosphate utilization in the study of glucose-6-phosphate dehydrogenase mosaicism.  

UK PubMed Central (United Kingdom)

The electrophoretic difference between normal glucose-6-phosphate dehydrogenase (G6PD) and two common variants (G6PD A and G6PD A-) has made the G6PD enzyme system very useful for genetic studies and for investigation on the clonal origin of tumors. This approach has not been possible for another common variant, G6PD mediterranean, which has a normal electrophoretic pattern. The different utilization of 2-deoxy-glucose-6-phosphate (2dG6P), an analog of the normal substrate, by the normal enzyme and the Mediterranean variant, allows a convenient determination of the degree of mosaicism in mononuclear cells from heterozygotes.

Ferraris AM; Giuntini P; Galiano S; Gaetani GF

1981-03-01

283

Penny wise and pound foolish: will shortsighted cost reduction measures compromise patient access to promising self-monitoring of blood glucose technology?  

UK PubMed Central (United Kingdom)

In this issue of Journal of Diabetes Science and Technology, Grady and coauthors enrolled 101 patients with type 1 and type 2 diabetes to evaluate new technology incorporated into the LifeScan VerioPro and VerioIQ blood glucose meters. The "pattern detection" software provides real-time, onscreen messages that alert users to patterns of high glucose (fasting and premeal) and low glucose as they are detected. The study showed that most participants possess a good understanding of the factors that can cause hyperglycemia; however, their understanding of the causes of hypoglycemia events was not as strong. Nevertheless, more than 70% of participants indicated they preferred to use a blood glucose meter that provides pattern detection capability. Although not designed to assess the impact of the pattern detection tool on clinical outcomes, the study highlights the value of continuous innovation in self-monitoring of blood glucose (SMBG) technology among manufacturers. Unfortunately, many patients may never have access to these systems due to reductions in Medicare reimbursement. Instead, they may be forced to use SMBG systems that are inaccurate and provide inadequate patient support. Stronger regulatory requirements are needed to ensure that all SMBG systems marketed to patients are accurate, reliable, and supported by adequate patient training, and current health care reimbursement policies should be restructured to encourage manufacturers to continue their efforts to develop innovative technology to further improve the utility and usability of their SMBG systems.

Parkin CG

2013-07-01

284

Penny wise and pound foolish: will shortsighted cost reduction measures compromise patient access to promising self-monitoring of blood glucose technology?  

Science.gov (United States)

In this issue of Journal of Diabetes Science and Technology, Grady and coauthors enrolled 101 patients with type 1 and type 2 diabetes to evaluate new technology incorporated into the LifeScan VerioPro and VerioIQ blood glucose meters. The "pattern detection" software provides real-time, onscreen messages that alert users to patterns of high glucose (fasting and premeal) and low glucose as they are detected. The study showed that most participants possess a good understanding of the factors that can cause hyperglycemia; however, their understanding of the causes of hypoglycemia events was not as strong. Nevertheless, more than 70% of participants indicated they preferred to use a blood glucose meter that provides pattern detection capability. Although not designed to assess the impact of the pattern detection tool on clinical outcomes, the study highlights the value of continuous innovation in self-monitoring of blood glucose (SMBG) technology among manufacturers. Unfortunately, many patients may never have access to these systems due to reductions in Medicare reimbursement. Instead, they may be forced to use SMBG systems that are inaccurate and provide inadequate patient support. Stronger regulatory requirements are needed to ensure that all SMBG systems marketed to patients are accurate, reliable, and supported by adequate patient training, and current health care reimbursement policies should be restructured to encourage manufacturers to continue their efforts to develop innovative technology to further improve the utility and usability of their SMBG systems. PMID:23911179

Parkin, Christopher G

2013-07-01

285

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)

Full Text Available Abstract in portuguese 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 obje (more) tivo 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 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 (more) 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

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

2012-12-01

286

Alternations in salivary glucose during ramadan fasting  

Directory of Open Access Journals (Sweden)

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.

Reyhaneh Sariri; Abdolali Varasteh; Ali Erfani

2010-01-01

287

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)

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

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

2012-10-06

288

Glucose Tolerance in Patients with Narcolepsy  

Science.gov (United States)

Study Objectives: Obesity is a common feature of narcolepsy. In addition, an increased occurrence of non-insulin dependent diabetes has been reported. So far, it is not known whether glucose metabolism in narcolepsy is disturbed due to, or independently of obesity. Design: Case-control study. Setting: Sleep medicine clinic at a research institute. Patients: We studied 17 patients with narcolepsy/cataplexy compared to 17 healthy controls matched for age, sex, and body mass index (BMI). Interventions: A 75-g oral glucose tolerance test was performed. Measurements: Glucose tolerance was determined by computing plasma glucose curve following oral glucose challenge for 240 minutes; insulin sensitivity and insulin secretion by homeostasis model assessment and minimal model analysis. Results: Standard outcome measures and indices of the oral glucose tolerance test did not differ between the patient group and the group of control subjects. Conclusions: In this study, no clinically relevant pathologic findings in the glucose metabolism of narcoleptic patients compared to weight matched controls were found. Thus, narcolepsy is unlikely to be a risk factor per se for impaired glucose tolerance or diabetes. Citation: Beitinger PA; Fulda S; Dalal MA; Wehrle R; Keckeis M; Wetter TC; Han F; Pollmächer T; Schuld A. Glucose tolerance in patients with narcolepsy. SLEEP 2012;35(2):231-236.

Beitinger, Pierre A.; Fulda, Stephany; Dalal, Mira A.; Wehrle, Renate; Keckeis, Marietta; Wetter, Thomas C.; Han, Fang; Pollmacher, Thomas; Schuld, Andreas

2012-01-01

289

ESD design for analog circuits  

CERN Multimedia

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.

Vashchenko, Vladislav A

2010-01-01

290

Beginning analog electronics through projects  

CERN Multimedia

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

Singmin, Andrew

2001-01-01

291

Blood Glucose Monitoring Devices  

Science.gov (United States)

... room for advice. How do you choose a Glucose Meter? There are many different types of meters available ... to your health care provider about the right glucose meter for you, and how to use it. How ...

292

Glucose Metabolism Measured by [18F]Fluorodeoxyglucose Positron Emission Tomography Is Independent of PTEN/AKT Status in Human Colon Carcinoma Cells1  

Science.gov (United States)

The phosphoinositide 3-kinase (PI3K) signaling pathway is one of the most altered in cancer, leading to a range of cellular responses including enhanced proliferation, survival, and metabolism, and is thus an attractive target for anticancer drug development. Stimulation of the PI3K pathway can be initiated by alterations at different levels of the signaling cascade including growth factor receptor activation, as well as mutations in PIK3CA, PTEN, and AKT genes frequently found in a broad range of cancers. Given its role in glucose metabolism, we investigated the utility of [18F]fluorodeoxyglucose positron emission tomography ([18F]FDG PET) as a pharmacodynamic biomarker of PI3K pathway-induced glucose metabolism. PTEN deletion in human colon carcinoma cells led to constitutive AKT activation but did not confer a phenotype of increased cell proliferation or glucose metabolism advantage in vivo relative to isogenic tumors derived from cells with a wild-type allele. This was not due to the activation context, that is, phosphatase activity, per se because PIK3CA activation in xenografts derived from the same lineage failed to increase glucose metabolism. Acute inhibition of PI3K activity by LY294002, and hence decreased activated AKT expression, led to a significant reduction in tumor [18F]FDG uptake that could be explained at least in part by decreased membrane glucose transporter 1 expression. The pharmacodynamic effect was again independent of PTEN status. In conclusion, [18F]FDG PET is a promising pharmacodynamic biomarker of PI3K pathway inhibition; however, its utility to detect glucose metabolism is not directly linked to the magnitude of activated AKT protein expression.

Nguyen, Quang-De; Perumal, Meg; Waldman, Todd A; Aboagye, Eric O

2011-01-01

293

Molecular Structure of Glucose  

Science.gov (United States)

Glucose is named after a Greek word meaning sugar or sweet. One of the most important compounds to life, glucose was first discovered by Andreas Marggraf in 1747. The structure for glucose was first discovered by Emil Fischer during the late 19th century and early 20th century. Glucose is found in all life forms and is used as a means of storing energy. When it polymerizes, it forms cellulose, which comprises plant structures.

2002-08-13

294

Comparison of 18F- and 11C-labeled aryloxyanilide analogs to measure translocator protein in human brain using positron emission tomography  

International Nuclear Information System (INIS)

[en] Translocator protein (TSPO) is a promising biomarker for neuroinflammation. We developed two new PET ligands, 18F-PBR06 and 11C-PBR28, to image TSPOs. Although our prior studies suggest that either of the two ligands could be used to quantify TSPOs in human brain, the studies were done in different sets of subjects. In this study, we directly compared 18F-PBR06 and 11C-PBR28 in eight human subjects to determine (1) whether either ligand provides more precise measurements of TSPOs and (2) whether the higher in vitro affinity of PBR06 compared to PBR28 led to higher in vivo binding of 18F-PBR06 compared to 11C-PBR28. In vivo binding was calculated as total distribution volume (VT), using an unconstrained two-tissue compartment model. VT was corrected for plasma free fraction (fP) to measure ligand binding based on free ligand concentration in brain. Both ligands measured VT with similar precision, as evidenced by similarly good identifiability. However, VT for both radioligands increased with increasing lengths of data acquisition, consistent with the accumulation of radiometabolites in brain. Despite its higher lipophilicity and higher in vitro affinity, VT/fP of 18F-PBR06 was similar to that of 11C-PBR28. Both 18F-PBR06 and 11C-PBR28 are similar in terms of precision, sensitivity to accumulation of radiometabolites, and magnitude of in vivo binding. Thus, selection between the two radioligands will be primarily determined by the logistical impact of the different half-lives of the two radionuclides (110 vs 20 min). (orig.)

2011-01-01

295

Comparison of {sup 18}F- and {sup 11}C-labeled aryloxyanilide analogs to measure translocator protein in human brain using positron emission tomography  

Energy Technology Data Exchange (ETDEWEB)

Translocator protein (TSPO) is a promising biomarker for neuroinflammation. We developed two new PET ligands, {sup 18}F-PBR06 and {sup 11}C-PBR28, to image TSPOs. Although our prior studies suggest that either of the two ligands could be used to quantify TSPOs in human brain, the studies were done in different sets of subjects. In this study, we directly compared {sup 18}F-PBR06 and {sup 11}C-PBR28 in eight human subjects to determine (1) whether either ligand provides more precise measurements of TSPOs and (2) whether the higher in vitro affinity of PBR06 compared to PBR28 led to higher in vivo binding of {sup 18}F-PBR06 compared to {sup 11}C-PBR28. In vivo binding was calculated as total distribution volume (V{sub T}), using an unconstrained two-tissue compartment model. V{sub T} was corrected for plasma free fraction (f{sub P}) to measure ligand binding based on free ligand concentration in brain. Both ligands measured V{sub T} with similar precision, as evidenced by similarly good identifiability. However, V{sub T} for both radioligands increased with increasing lengths of data acquisition, consistent with the accumulation of radiometabolites in brain. Despite its higher lipophilicity and higher in vitro affinity, V{sub T}/f{sub P} of {sup 18}F-PBR06 was similar to that of {sup 11}C-PBR28. Both {sup 18}F-PBR06 and {sup 11}C-PBR28 are similar in terms of precision, sensitivity to accumulation of radiometabolites, and magnitude of in vivo binding. Thus, selection between the two radioligands will be primarily determined by the logistical impact of the different half-lives of the two radionuclides (110 vs 20 min). (orig.)

Dickstein, Leah P.; Zoghbi, Sami S.; Fujimura, Yota; Imaizumi, Masao; Zhang, Yi; Pike, Victor W.; Innis, Robert B.; Fujita, Masahiro [National Institutes of Health, Molecular Imaging Branch, National Institute of Mental Health, Bethesda, MD (United States)

2011-02-15

296

Novel PEGylated Basal Insulin LY2605541 Has a Preferential Hepatic Effect on Glucose Metabolism.  

UK PubMed Central (United Kingdom)

The impact of the novel basal insulin LY2605541 (LY) on hepatic and nonhepatic glucose uptake was evaluated. Conscious dogs underwent euglycemic clamps with tracer and hepatic balance measurements. Clamp period infusions were: peripheral venous regular insulin (0.1 nmol·kg(-1)·h(-1) [Control], n=6) or LY (bolus [nmol/kg], continuous [nmol·kg(-1)·h(-1)]: 0.5, 0.5 [n=6]; 0.375, 0.375 [n=5]; 0.25,0.25 [n=4]), somatostatin, and glucose, as well as intraportal glucagon (basal). During the clamp, the dogs switched from net hepatic glucose output to uptake (rates reached 2.1±1.2, 0.9±2.1, 8.6±2.3, and 6.0±1.1 µmol·kg(-1)·min(-1) within 5h in Control, LY0.25, LY0.375, and LY0.5, respectively). Nonhepatic glucose uptake (nonHGU) in LY increased less than in Control; the ratio of change from basal in nonHGU:change in net hepatic glucose balance, calculated when GIRs were ?20 µmol(.)kg(-1.)min(-1) in all groups, was higher in Control (1.17±0.38) versus LY0.25 (0.39±0.33), LY0.375 (-0.01±0.13), and LY0.5 (-0.09±0.07). Likewise, the change from baseline in glucose rate of disappearance:appearance ratio was greatest in Control (1.4±0.3 versus 0.6±0.4, 0.5±0.2, and 0.6±0.2 in LY0.25, LY0.375, and LY0.5, respectively). In contrast to exogenously-administered human insulin, LY2605541 demonstrated preferential hepatic effects, similar to endogenously-secreted insulin. Therefore the analog might reduce complications associated with current insulin therapy.

Moore MC; Smith MS; Sinha VP; Beals JM; Michael MD; Jacober SJ; Cherrington AD

2013-10-01

297

Assessment of glucose metabolism in humans with the simultaneous use of indirect calorimetry and tracer techniques.  

UK PubMed Central (United Kingdom)

Concomitant measurements of sytemic glucose delivery and carbohydrate oxidation are frequently performed in human investigations. Systemic glucose delivery (SGD) is usually determined using dilution of infused glucose tracers; net carbohydrate oxidation rate (net CHOOX) can be calculated from respiratory gas exchanges and urinary nitrogen excretion (indirect calorimetry); alternatively, glucose oxidation can be measured from labelled CO2 production during infusion of carbon-labelled glucose tracers. In this paper, the theory underlying the use of each of these techniques is briefly reviewed and qualitative differences are outlined. SGD represents the sum of hepatic glucogenolysis, gluconeogenesis from amino acids or glycerol, and, according to the glucose tracer used, glucose cycles (glucose-phosphate cycle, fructose-phosphate cycle, Cori and glucose-alanine cycles); systemic delivery of exogenous glucose after oral or i.v. glucose administration is also measured. Net CHOOX represents oxidation of glucose arising from hepatic or muscle glycogen or from exogenous glucose; it does not take into account oxidation of glucose formed from amino acids or glycerol, which is included in net protein or lipid oxidation. In contrast, isotopic determination of glucose oxidation corresponds to oxidation of glucose originating from hepatic glycogen breakdown, of exogenously administered glucose, and of glucose formed from amino acids and glycerol. Non-oxidative glucose disposal, calculated as SGD-net CHOOX, corresponds to the sum of gluconeogenesis from amino acids or glycerol (which are included in net protein and lipid oxidation), glucose cycles, and glycogen synthesis.

Tappy L; Paquot N; Tounian P; Schneiter P; Jéquier E

1995-01-01

298

[Analogies and analogy research in technical biology and bionics].  

UK PubMed Central (United Kingdom)

The procedural approaches of Technical Biology and Bionics are characterized, and analogy research is identified as their common basis. The actual creative aspect in bionical research lies in recognizing and exploiting technically oriented analogies underlying a specific biological prototype to indicate a specific technical application.

Nachtigall W

2010-01-01

299

Measurements of Thermal Conductivity Variations with Temperature for the Organic Analog of the Nonmetal-Nonmetal System: Urea-4-Bromo-2-Nitroaniline  

Science.gov (United States)

Thermal conductivity variations with temperature for solid phases in the Urea (U)-[ X] mol pct 4-bromo-2-nitroaniline (BNA) system ( X = 0, 2, 45, 89.9, and 100) were measured using the radial heat flow method. From graphs of thermal conductivity variations with temperature, the thermal conductivities of the solid phases at their melting temperature and temperature coefficients for the U-[ X] mol pct BNA system ( X = 0, 2, 45, 89.9, and 100) were found to be 0.26, 0.55, 0.46, 0.38, and 0.23 W/Km and 0.007781, 0.005552, 0.002058, 0.002188, and 0.002811 K-1, respectively. The ratios of thermal conductivity of the liquid phase to thermal conductivity of the solid phase in the U-[ X] mol pct BNA system ( X = 0, 2, 45, 89.9, and 100) were also measured to be 0.30, 0.44, 0.46, 0.49, and 0.51, respectively, with a Bridgman-type directional solidification apparatus at their melting temperature.

Bayram, Ümit; Öztürk, Esra; Aksöz, Sezen; Mara?l?, Necmettin

2013-09-01

300

CONDENSATE GLUCOSE ANALYZER  

UK PubMed Central (United Kingdom)

Systems and methods for analyzing glucose present in exhaled breath conde nsate (EBC). In certain embodiments, electrochemical- or coulometnc-based se nsing technologies are used to analyze EBC for the presence and/or concentra tion of glucose. Based on the detected glucose m EBC, the subject invention provides systems and methods for non-mvasive, accurate assessment of blood g lucose levels.

BJORAKER DAVID G; BATICH CHRISTOPHER D; BOOTH MATTHEW M; MOREY TIMOTHY E; YOUNGBLOOD RONALD; HORN JOHN FREDERICK; MELKER RICHARD J; DENNIS DONN MICHAEL; STEWART JON DALE

 
 
 
 
301

Glucose kinase has a regulatory role in carbon catabolite repression in Streptomyces coelicolor.  

Digital Repository Infrastructure Vision for European Research (DRIVER)

A glucose kinase (glkA) mutant of Streptomyces coelicolor A3(2) M145 was selected by the ability to grow in the presence of the nonmetabolizable glucose analog 2-deoxyglucose. In this glkA mutant, carbon catabolite repression of glycerol kinase and agarase was relieved on several carbon sources test...

Kwakman, J H; Postma, P W

302

Prevalence of glucose abnormalities and diagnostic value of fasting glucose and fasting insulin in urban hispanics.  

Science.gov (United States)

The prevalence of glucose abnormalities (GAs) and the diagnostic value of fasting plasma glucose and insulin in detecting impaired glucose tolerance (IGT) and diabetes mellitus (DM) were determined in urban Latin Americans. An oral glucose tolerance test was conducted in 592 subjects after administration of 75 g of glucose. Employing American Diabetes Association (ADA) and World Health Organization guidelines, GAs were found in 34% of the subjects, defined as impaired fasting glucose (IFG) (13.3%), IGT (6.9%), combined IFG + IGT (7.8%), and newly diagnosed type-2-DM (6.5%). All newly diagnosed diabetics had 2-hour glucose levels ?200 mg/dL, but only 46.1% had fasting glucose ?126 mg/dL. In addition, nearly half of the subjects with IGT (47%) had fasting glucose levels Caracas, Venezuela, requires immediate sanitary attention. With 50% of diabetic patients being unaware of their condition, half of IGT and DM not detected by ADA guidelines, and the poor sensitivity/specificity of fasting glucose in predicting 2-hour abnormalities, we recommend that 2-hour postload glucose be included when screening for GAs. Measurements of fasting and/or postload insulin are not cost effective for the diagnosis of GA, because they provide little additional clinical information in this context. PMID:23528370

Hoffmann, Irene S; Alfieri, Anna B; Cubeddu, Luigi X

303

Association of VO2 and VCO2 rate variability with serum glucose, insulin, and glucose intolerance.  

UK PubMed Central (United Kingdom)

Changes in the cellular metabolism assessed by the variability of oxygen consumption (VO(2) ) and carbon dioxide production (VCO(2) ) as well as the association of serum glucose and insulin to energy spectral density (ESD) of VO(2) and VCO(2) were evaluated. Ten nonglucose intolerant and 10 glucose intolerant subjects, aged 21-70 years, were included. Glucose and insulin concentrations and VO(2) and VCO(2) records were collected every 10 min during 3 h. ESD of VO(2) and VCO(2) was estimated and associated with glucose and insulin concentrations. Statistical significance in glucose levels, insulin, and ESD of VO(2) and VCO(2) among nonglucose intolerant subjects and glucose and insulin among glucose intolerance subjects at postload glucose (PLG) state compared with basal state was found. Moreover, glucose was significantly higher in glucose intolerance subjects than nonglucose intolerant subjects for basal and PLG states. These results show an increment in ESD of VO(2) and VCO(2) at PLG state among nonglucose intolerant subjects and suggest that their measurement may be a key indicator of the variability of cellular metabolic activity and contribute to confirm disturbances in glucose metabolism.

Satué-Rodríguez J; Méndez JD

2012-08-01

304

Association of VO2 and VCO2 rate variability with serum glucose, insulin, and glucose intolerance.  

Science.gov (United States)

Changes in the cellular metabolism assessed by the variability of oxygen consumption (VO(2) ) and carbon dioxide production (VCO(2) ) as well as the association of serum glucose and insulin to energy spectral density (ESD) of VO(2) and VCO(2) were evaluated. Ten nonglucose intolerant and 10 glucose intolerant subjects, aged 21-70 years, were included. Glucose and insulin concentrations and VO(2) and VCO(2) records were collected every 10 min during 3 h. ESD of VO(2) and VCO(2) was estimated and associated with glucose and insulin concentrations. Statistical significance in glucose levels, insulin, and ESD of VO(2) and VCO(2) among nonglucose intolerant subjects and glucose and insulin among glucose intolerance subjects at postload glucose (PLG) state compared with basal state was found. Moreover, glucose was significantly higher in glucose intolerance subjects than nonglucose intolerant subjects for basal and PLG states. These results show an increment in ESD of VO(2) and VCO(2) at PLG state among nonglucose intolerant subjects and suggest that their measurement may be a key indicator of the variability of cellular metabolic activity and contribute to confirm disturbances in glucose metabolism. PMID:22714977

Satué-Rodríguez, Julián; Méndez, José D

2012-06-19

305

Underestimation of glucose turnover corrected with high-performance liquid chromatography purification of [6-3H]glucose  

International Nuclear Information System (INIS)

[en] We have recently reported that during infusion of commercially available [6-3H]glucose, a radioactive nonglucose contaminant may accumulate in plasma causing errors in the measurement of glucose turnover. To determine whether purification of this tracer by HPLC (high-performance liquid chromatography) before infusion would eliminate the contaminant in plasma and remove the underestimation of glucose turnover reported during hyperinsulinemia, four normal subjects each underwent two 5-h euglycemic clamps during infusion of insulin (1 mU.kg-1.min-1). Glucose turnover was measured with either commercially available [6-3H]glucose or with HPLC-purified [6-3H]glucose. HPLC analysis of samples from the clamps done with commercially available [6-3H]glucose showed that 9.7% of the infused tracer and 26% of the plasma glucose 3H radioactivity were contaminants. In contrast, no contaminant was observed in the plasma during infusion of HPLC-purified [6-3H]glucose. During the last hour of the clamp, mean glucose turnover using commercially available [6-3H]glucose was less (P less than 0.01) than the mean glucose infusion rate (7.6 +/- 0.3 vs. 10.5 +/- 0.3 mg.kg-1.min-1) yielding apparent negative (P less than 0.001) hepatic glucose release. In contrast, when HPLC-purified [6-3H]glucose was employed, glucose turnover equaled the glucose infusion rate (10.4 +/- 0.9 vs. 10.2 +/- 0.9 mg.kg-1.min-1) and hepatic glucose release was no longer negative. We conclude that removal of a tritiated nonglucose contaminant in [6-3H]glucose by HPLC yields correct estimations of glucose turnover at steady state

1990-01-01

306

Underestimation of glucose turnover corrected with high-performance liquid chromatography purification of (6- sup 3 H)glucose  

Energy Technology Data Exchange (ETDEWEB)

We have recently reported that during infusion of commercially available (6-3H)glucose, a radioactive nonglucose contaminant may accumulate in plasma causing errors in the measurement of glucose turnover. To determine whether purification of this tracer by HPLC (high-performance liquid chromatography) before infusion would eliminate the contaminant in plasma and remove the underestimation of glucose turnover reported during hyperinsulinemia, four normal subjects each underwent two 5-h euglycemic clamps during infusion of insulin (1 mU.kg-1.min-1). Glucose turnover was measured with either commercially available (6-3H)glucose or with HPLC-purified (6-3H)glucose. HPLC analysis of samples from the clamps done with commercially available (6-3H)glucose showed that 9.7% of the infused tracer and 26% of the plasma glucose 3H radioactivity were contaminants. In contrast, no contaminant was observed in the plasma during infusion of HPLC-purified (6-3H)glucose. During the last hour of the clamp, mean glucose turnover using commercially available (6-3H)glucose was less (P less than 0.01) than the mean glucose infusion rate (7.6 +/- 0.3 vs. 10.5 +/- 0.3 mg.kg-1.min-1) yielding apparent negative (P less than 0.001) hepatic glucose release. In contrast, when HPLC-purified (6-3H)glucose was employed, glucose turnover equaled the glucose infusion rate (10.4 +/- 0.9 vs. 10.2 +/- 0.9 mg.kg-1.min-1) and hepatic glucose release was no longer negative. We conclude that removal of a tritiated nonglucose contaminant in (6-3H)glucose by HPLC yields correct estimations of glucose turnover at steady state.

Schwenk, W.F.; Butler, P.C.; Haymond, M.W.; Rizza, R.A. (Mayo Foundation, Rochester, MN (USA))

1990-01-01

307

Dynamic glucose sensor controlled circuit  

UK PubMed Central (United Kingdom)

The utility model discloses a dynamic glucose sensor control circuit, including a sensor determination module, a data-processing module and a microprocessor connected in proper order. The sensor determination module is arranged with a negative electrode and a positive electrode. A display module connecting the output end of the microprocessor, and a keyboard circuit, an interface converter circuit and a memory circuit connecting the microprocessor are included as well. The utility model adopts the sensor determination module for determination of glucose concentrations of tissue fluids of patients. The data measured are converted, processed and outputted into LCD display module for real-time display, so that the patients can get the results anytime and anywhere. The hyperglykemia threshold, hypoglycemia threshold and reference blood glucose concentration are set specifically through the keyboard circuit. The serial port output of the microprocessor will be converted into USB port output, to facilitate connection with the computer.

YANAN ZHANG; YINGFAN ZENG

308

Statins impair glucose uptake in tumor cells.  

UK PubMed Central (United Kingdom)

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.

Malenda A; Skrobanska A; Issat T; Winiarska M; Bil J; Oleszczak B; Sinski M; Firczuk M; Bujnicki JM; Chlebowska J; Staruch AD; Glodkowska-Mrowka E; Kunikowska J; Krolicki L; Szablewski L; Gaciong Z; Koziak K; Jakobisiak M; Golab J; Nowis DA

2012-04-01

309

Glucose sensors: a review of current and emerging technology.  

UK PubMed Central (United Kingdom)

Glucose monitoring technology has been used in the management of diabetes for three decades. Traditional devices use enzymatic methods to measure glucose concentration and provide point sample information. More recently continuous glucose monitoring devices have become available providing more detailed data on glucose excursions. In future applications the continuous glucose sensor may become a critical component of the closed loop insulin delivery system and, as such, must be selective, rapid, predictable and acceptable for continuous patient use. Many potential sensing modalities are being pursued including optical and transdermal techniques. This review aims to summarize existing technology, the methods for assessing glucose sensing devices and provide an overview of emergent sensing modalities.

Oliver NS; Toumazou C; Cass AE; Johnston DG

2009-03-01

310

Noninvasive measurement of murine hepatic acetyl-CoA ¹³C-enrichment following overnight feeding with ¹³C-enriched fructose and glucose.  

UK PubMed Central (United Kingdom)

The (13)C-isotopomer enrichment of hepatic cytosolic acetyl-CoA of overnight-fed mice whose drinking water was supplemented with [U-(13)C]fructose, and [1-(13)C]glucose and p-amino benzoic acid (PABA) was quantified by (13)C NMR analysis of urinary N-acetyl-PABA. Four mice were given normal chow plus drinking water supplemented with 5% [1-(13)C]glucose, 2.5% [U-(13)C]fructose, and 2.5% fructose (Solution 1) overnight. Four were given chow and water containing 17.5% [1-(13)C]glucose, 8.75% [U-(13)C]fructose and 8.75% fructose (Solution 2). PABA (0.25%) was present in both studies. Urinary N-acetyl-PABA was analyzed by (13)C NMR. In addition to [2-(13)C]- and [1,2-(13)C]acetyl isotopomers from catabolism of [U-(13)C]fructose and [1-(13)C]glucose to acetyl-CoA, [1-(13)C]acetyl was also found indicating pyruvate recycling activity. This precluded precise estimates of [1-(13)C]glucose contribution to acetyl-CoA while that of [U-(13)C]fructose was unaffected. The fructose contribution to acetyl-CoA from Solutions 1 and 2 was 4.0 ± 0.4% and 10.6 ± 0.6%, respectively, indicating that it contributed to a minor fraction of lipogenic acetyl-CoA under these conditions.

Carvalho F; Duarte J; Simoes AR; Cruz PF; Jones JG

2013-01-01

311

Noninvasive Measurement of Murine Hepatic Acetyl-CoA 13C-Enrichment Following Overnight Feeding with 13C-Enriched Fructose and Glucose  

Science.gov (United States)

The 13C-isotopomer enrichment of hepatic cytosolic acetyl-CoA of overnight-fed mice whose drinking water was supplemented with [U-13C]fructose, and [1-13C]glucose and p-amino benzoic acid (PABA) was quantified by 13C NMR analysis of urinary N-acetyl-PABA. Four mice were given normal chow plus drinking water supplemented with 5% [1-13C]glucose, 2.5% [U-13C]fructose, and 2.5% fructose (Solution 1) overnight. Four were given chow and water containing 17.5% [1-13C]glucose, 8.75% [U-13C]fructose and 8.75% fructose (Solution 2). PABA (0.25%) was present in both studies. Urinary N-acetyl-PABA was analyzed by 13C NMR. In addition to [2-13C]- and [1,2-13C]acetyl isotopomers from catabolism of [U-13C]fructose and [1-13C]glucose to acetyl-CoA, [1-13C]acetyl was also found indicating pyruvate recycling activity. This precluded precise estimates of [1-13C]glucose contribution to acetyl-CoA while that of [U-13C]fructose was unaffected. The fructose contribution to acetyl-CoA from Solutions 1 and 2 was 4.0 ± 0.4% and 10.6 ± 0.6%, respectively, indicating that it contributed to a minor fraction of lipogenic acetyl-CoA under these conditions.

Carvalho, Filipa; Duarte, Joao; Simoes, Ana Rita; Cruz, Pedro F.; Jones, John G.

2013-01-01

312

Natural analog studies: Licensing perspective  

Energy Technology Data Exchange (ETDEWEB)

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.

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

1995-09-01

313

SOLID FORMULATIONS OF PROSTACYCLIN ANALOGS  

UK PubMed Central (United Kingdom)

Moderate moisture levels, such as greater than 3% but no greater than 7%, may be beneficial for solid formulations of certain prostacyclin analogs. Accordingly, a solid formulation containing a prostacyclin analog may be packaged inside a pharmaceutical packaging with such amount of a desiccant or a drying agent that after the storage the solid formulation may have a moderate level of moisture in it.

PHARES KENNETH R

314

Diabetic hypoglycemia: a case of different capillary blood glucose readings from two identical glucose meters  

Directory of Open Access Journals (Sweden)

Full Text Available A 61-year old male with a 54-year history of type 1 diabetes, hypertension and ischemic heart disease became drowsy while attending the hospital diabetes outpatient department. Capillary blood glucose was measured at 3.8 mmol/l and he was treated for presumed hyopglycemia with a glucose drink followed by intravenous dextrose; 25 minutes later, a different glucose meter was used to record a capillary blood glucose value of 7.8 mmol/l. Because recovery was slow, the patient was transferred to the Emergency Department. A laboratory blood glucose result from a sample taken 5 minutes before the second glucose meter measurement reported levels of 2.5 mmol/l. This case illustrates how two blood glucose meters of the same make and model can give significantly different results; other sources of diagnostic inaccuracy are discussed. Clinical suspicion of hypoglycemia requires prompt treatment whether or not capillary blood glucose can be measured immediately. When possible, confirmatory laboratory measurement of venous blood glucose should be obtained in cases of suspected severe hypoglycemia.

Alex J Graveling

2010-01-01

315

BROAD SPECTRUM ANTIBIOTIC ARYLOMYCIN ANALOGS  

UK PubMed Central (United Kingdom)

Arylomycin analogs are provided, wherein the analogs can have broad spectrum bioactivity. Resistance to the antibiotic bioactivity of natural product arylomycin in a range of pathogenic bacterial species has been found to depend upon single amino acid mutations at defined positions of bacterial Signal Peptidases (SPases), wherein the presence of a proline residue confers arylomycin resistance. Arylomycin analogs are provided herein that can overcome that resistance and provide for a broader spectrum of antibiotic bioactivity than can natural product arylomycins such as arylomycin A2. Methods for determining if a bacterial strain is susceptible to narrow spectrum arylomycin antibiotics, or if a broad spectum analog is required for treatment, is provided. Pharmaceutical compositions and methods of treatment of bacterial infections, and methods of synthesis of arylomycin analogs, are provided.

ROMESBERG FLOYD E; SMITH PETER A; ROBERTS TUCKER C

316

Parking Structures: Fuss Analogs  

CERN Multimedia

For any irreducible real reflection group $W$ with Coxeter number $h$, Armstrong, Reiner, and the author introduced a pair of $W \\times \\ZZ_h$-modules which deserve to be called {\\sf $W$-parking spaces} which generalize the type A notion of parking functions and conjectured a relationship between them. In this paper we give a Fuss analog of their constructions. For a Fuss parameter $k \\geq 1$, we define a pair of $W \\times \\ZZ_{kh}$-modules which deserve to be called {\\sf $k$-$W$-parking spaces} and conjecture a relationship between them. We prove the weakest version of our conjectures for each of the infinite families ABCDI of finite reflection groups, together with proofs of stronger versions in special cases. Whenever our weakest conjecture holds for $W$, we have the following corollaries. First, there is a simple formula for the character of either $k$-$W$-parking space. Second, we recover a cyclic sieving result due to Krattenthaler and M\\"uller which gives the cycle structure of a generalized rotation a...

Rhoades, Brendon

2012-01-01

317

Haemoglobin glycation may partly explain the discordance between HbA1c measurement and oral glucose tolerance test to diagnose dysglycaemia in overweight/obese subjects.  

UK PubMed Central (United Kingdom)

AIM: This study assessed whether the poor correlation between HbA1c and oral glucose tolerance test (OGTT) for dysglycaemia diagnosis may be explained by haemoglobin glycation (HbG). METHODS: A total of 1033 consecutive overweight or obese patients with no known diabetes underwent OGTT and measurement of HbA1c to diagnose diabetes and dysglycaemia (American Diabetes Association criteria). For each OGTT result category, low, medium and high HbG was defined according to the mean HbA1c/fructosamine ratio and mean fructosamine. High HbG was defined as values greater than mean values in each OGTT category for both HbA1c/fructosamine ratio and fructosamine levels, and low HbG was defined as lower values of both. The remaining patients were considered medium HbG. RESULTS: Based on OGTT and HbA1c values, 267 (25.8%) and 443 (42.8%) patients had intermediate hyperglycaemia, and 66 (6.4%) and 95 (9.2%) patients had diabetes, respectively. The results were discordant for intermediate hyperglycaemia or diabetes diagnosis in 41.7% and for diabetes diagnosis in 10.0% of the patients. The proportion of patients with HbA1c?6.5%, but without OGTT-diagnosed diabetes, was 0%, 3.8% and 32.8% in the low-HbG, medium-HbG and high-HbG groups, respectively. In contrast, the proportion of patients with HbA1c<5.7%, but with an abnormal OGTT, was 30.4%, 11.1% and 0%, respectively. The AUROC of HbA1c to detect OGTT-diagnosed diabetes was better in the medium-HbG group [0.874 (0.816-0.931)] than in those with low or high HbG [0.628 (0.489-0.768); P<0.01]. Only age was independently associated with high-HbG status [10-year OR: 1.3 (1.1-1.5); P<0.0001]. CONCLUSION: Haemoglobin glycation may explain many of the discordant results between HbA1c and OGTT when used for dysglycaemia diagnosis.

Cosson E; Chiheb S; Cussac-Pillegand C; Banu I; Hamo-Tchatchouang E; Nguyen MT; Aout M; Charnaux N; Valensi P

2013-04-01

318

New ganglioside analogs that inhibit influenza virus sialidase.  

Science.gov (United States)

Synthetic thioglycoside-analogs of gangliosides such as Neu5Ac alpha(2-S-6)Glc beta(1-1)Ceramide (1) and the GM3 analog Neu5Ac alpha(2-S-6)Gal beta(1-4)Glc beta(1-1)Ceramide (2), competitively inhibited GM3 hydrolysis by the sialidase of different subtypes of human and animal influenza viruses with an apparent Ki value of 2.8 x 10(-6) and 1.5 x 10(-5) M, respectively. The inhibitory activity of the ganglioside GM4 analog [Neu5Ac alpha(2-S-6)Gal beta(1-1)Ceramide (3)], in which the glucose of 1 was substituted by galactose, was lower than that of 1 (Ki = 1.0 x 10(-4) M). The thioglycoside-analogs (1, 2, 3) of the gangliosides were non-hydrolyzable substrates for influenza virus sialidase. The inhibitory activity of 1 to bacterial sialidases from Clostridium perfringens and Arthrobacter ureafaciens was considerably lower than that to influenza virus sialidase, indicating that the structure of the active site in bacterial and influenza virus sialidase may be different and the analogs may be useful to determine the orientation of the substrate to the active site of sialidases, especially of influenza viruses. PMID:2136350

Suzuki, Y; Sato, K; Kiso, M; Hasegawa, A

1990-01-01

319

[Clinical and metabolic features of subjects with glucose intolerance and high fasting glucose levels].  

UK PubMed Central (United Kingdom)

BACKGROUND: Subjects with glucose intolerance or high fasting glucose levels have a higher cardiovascular risk and frequently become diabetic. AIM: To assess clinical and metabolic characteristics of patients with glucose intolerance or high fasting glucose levels. MATERIAL AND METHODS: Fasting and post glucose load serum glucose and insulin levels were measured in 1404 people, aged 42,0 +/- 14,2 years (81% women) with high diabetic risk. We categorized subjects in different alterations of blood glucose, according to 2006 American Diabetes Association categories. Insulin resistance (RI), insulin secretion (beta %) and insulin disposition (ID), were calculated using fasting blood glucose and insulin levels, using the homeostasis model assessment (HOMA I and II). RESULTS: Sixty percent of studied subjects had first grade relatives with diabetes mellitus and 1097 (78%) were categorized as normal (N), 45 (3%) as Diabetes Mellitus (DM), 161 (11%) as high fasting glucose levels (GAA) and 103 (7%) as glucose intolerant (ITG). Fifty three of the 106 subjects with GAA (50%), were also glucose intolerant. Subjects with GAA had similar insulin sensitivity and lower beta cell function than N (insulin disposition 58 +/- 12 and 111 +/- 32%, respectively p < 0.01). ITG had less insulin sensitivity than N (HOMA-IR 2.6 +/- 1.50 +/- and 2.0 +/- 1.30, respectively) and only a mild decrease in beta cell function (insulin disposition 96 +/- 26 and 111 +/- 32% respectively, p < 0.01). Patients GAA plus ITG had similar alterations than those with DM (HOMA-IR 3.8 +/- 2.2 and 4.4 +/- 3.7 respectively; insulin disposition 57 +/- 10 and 56.0 +/- 26% respectively. CONCLUSIONS: Patients with higher fasting glucose levels behave differently from those with glucose intolerance. High fasting glucose levels are highly prevalent in subjects with high risk of DM and must be considered as risk indicator in preventive programs for diabetes mellitus.

Arteaga Llona A; Pollak F; Robres L; Velasco N

2009-02-01

320

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

Energy Technology Data Exchange (ETDEWEB)

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-/sup 14/C)glycerol and (6-/sup 3/H)glucose were given intravenously as a single dose injection. The time course of the specific radioactivities of (6-/sup 3/H) and (U-/sup 14/C)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 (/sup 14/C)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 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.

Lundholm, K.; Edstroem, S.; Karlberg, I.; Ekman, L.; Schersten, T.

1982-09-15

 
 
 
 
321

Simultaneous measurement of neuronal and glial metabolism in rat brain in vivo using co-infusion of [1,6-13C2]glucose and [1,2-13C2]acetate.  

UK PubMed Central (United Kingdom)

In this work the feasibility of measuring neuronal-glial metabolism in rat brain in vivo using co-infusion of [1,6-(13)C(2)]glucose and [1,2-(13)C(2)]acetate was investigated. Time courses of (13)C spectra were measured in vivo while infusing both (13)C-labeled substrates simultaneously. Individual (13)C isotopomers (singlets and multiplets observed in (13)C spectra) were quantified automatically using LCModel. The distinct (13)C spectral pattern observed in glutamate and glutamine directly reflected the fact that glucose was metabolized primarily in the neuronal compartment and acetate in the glial compartment. Time courses of concentration of singly and multiply-labeled isotopomers of glutamate and glutamine were obtained with a temporal resolution of 11 min. Although dynamic metabolic modeling of these (13)C isotopomer data will require further work and is not reported here, we expect that these new data will allow more precise determination of metabolic rates as is currently possible when using either glucose or acetate as the sole (13)C-labeled substrate.

Deelchand DK; Nelson C; Shestov AA; U?urbil K; Henry PG

2009-02-01

322

Simultaneous measurement of neuronal and glial metabolism in rat brain in vivo using co-infusion of [1,6-13C2]glucose and [1,2-13C2]acetate  

Science.gov (United States)

In this work the feasibility of measuring neuronal-glial metabolism in rat brain in vivo using co-infusion of [1,6-13C2]glucose and [1,2-13C2]acetate was investigated. Time courses of 13C spectra were measured in vivo while infusing both 13C-labeled substrates simultaneously. Individual 13C isotopomers (singlets and multiplets observed in 13C spectra) were quantified automatically using LCModel. The distinct 13C spectral pattern observed in glutamate and glutamine directly reflected the fact that glucose was metabolized primarily in the neuronal compartment and acetate in the glial compartment. Time courses of concentration of singly and multiply-labeled isotopomers of glutamate and glutamine were obtained with a temporal resolution of 11 min. Although dynamic metabolic modeling of these 13C isotopomer data will require further work and is not reported here, we expect that these new data will allow more precise determination of metabolic rates as is currently possible when using either glucose or acetate as the sole 13C-labeled substrate.

Deelchand, Dinesh K.; Nelson, Christopher; Shestov, Alexander A.; U?urbil, Kâmil; Henry, Pierre-Gilles

2009-02-01

323

Fault diagnosis of analog circuits  

Energy Technology Data Exchange (ETDEWEB)

In this paper, various fault location techniques in analog networks are described and compared. The emphasis is on the more recent developments in the subject. Four main approaches for fault location are addressed, examined, and illustrated using simple network examples. In particular, we consider the fault dictionary approach, the parameter identification approach, the fault verification approach, and the approximation approach. Theory and algorithms that are associated with these approaches are reviewed and problems of their practical application are identified. Associated with the fault dictionary approach we consider fault dictionary construction techniques, methods of optimum measurement selection, different fault isolation criteria, and efficient fault simulation techniques. Parameter identification techniques that either utilize linear or nonlinear systems of equations to identify all network elements are examined very thoroughly. Under fault verification techniques we discuss node-fault diagnosis, branch-fault diagnosis, subnetwork testability conditions as well as combinatorial techniques, the failure bound technique, and the network decomposition technique. For the approximation approach we consider probabilistic methods and optimization-based methods. The artificial intelligence technique and the different measures of testability are also considered. The main features of the techniques considered are summarized in a comparative table. An extensive, but not exhaustive, bibliography is provided.

Bandler, J.W.; Salama, A.E.

1985-08-01

324

Plasma glucose levels and flight  

Directory of Open Access Journals (Sweden)

Full Text Available Background: Noise is able to exert many adverse health effects, ranging from damages on various organs and systems to changes in biochemical and humoral markers. In literature, the effects of chronic exposure to noise on blood glucose levels have been reported, although these results are conflicting: some authors reported hyperglycaemia, others hypoglycaemia and many others recorded no changes in blood glucose levels. Objectives: Considering that the plasma glucose levels are not used as a biomarker of noise exposure, we conducted a pilot study on 6 subjects, 2 females and 4 males, working as clerks in a low noise environment in order to evaluate the possible occurrence of changes on plasma glucose levels in healthy subjects, non-diabetic and not accustomed to flight, exposed to noise and to flight-related stressors. Methods: The subjects completed a specific clinic-anamnestic questionnaire and underwent a general clinical examination. In the first phase of the study, participants underwent blood tests in order to assess the plasma glucose levels at three different times: at 8:00 a.m., on board of a turboprop transport aircraft before the take-off with the engine switched off, after 60 and 120 minutes’ flight. The second phase of the study was carried out one month after the first one and while working in the office; three blood tests were performed again, at fasting and after 60 and 120 minutes. The plasma glucose levels were measured on capillary blood by the refractometry method through the use of Glucoscan One Touch device. Results: The results show an increase of plasma glucose levels during the waiting for the flight and a statistically significant decrease of plasma glucose levels in the first hour of flight (p <0.001), persisting even at the second hour (p <0.001). No significant changes were found in the blood tests performed at work. Discussion: The data show an initial hyperglycaemic response, followed by a persistent and moderate decrease of glycaemia; a similar response was not observed in the same subjects during ordinary work activities. The Authors believe that the initial increase of the plasma glucose levels, recorded in absence of noise on board, could be related to the response to other stressors, such as anxiety linked to the waiting for the flight. The decrease of the plasma glucose levels observed after 60 and 120 minutes’ flight, that is in conditions of prolonged exposure to flight-related stressors and to noise, may be linked to the intervention of several mechanisms: partial phenomenon of adaptation-exhaustion of the neuroendocrine response to stress; hypoglycaemic effect of noise, CCK-mediated and VIP-mediated with consequent insulin release and decrease of the plasma glucose levels; synergistic action of the above mechanisms. The absence of changes on the plasma glucose levels during the usual work activity is probably due to the absence of those stressors considered able to induce the alterations of the plasma glucose levels recorded during the first phase of the study. Conclusions: These preliminary results suggest that exposure to flight-related stressors and in particular exposure to noise can cause a hypoglycaemic response.

Tomei G; Loreti B; Rosati MV; Tomao E; Sinibaldi F; De Sio S; Casale T; Pimpinella B; Di Pastena C; Tomei F; Stansfeld S; Andrè JC; Caciari T

2013-01-01

325

Characterization of Lasers for Use in Analog Photonic Links.  

Science.gov (United States)

A survey of lasers was conducted to characterize their performance as it relates to analog photonic link applications. The methods used to measure a laser's noise spectrum, linewidth, and optical spectrum are presented along with the results of those meas...

J. Diehl J. M. Singley V. J. Urick

2011-01-01

326

Analogic fiber optic position sensor with nanometric resolution  

Digital Repository Infrastructure Vision for European Research (DRIVER)

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.

Lamarque, Frédéric; Prelle, Christine

327

Glucose tolerance in patients with narcolepsy.  

UK PubMed Central (United Kingdom)

STUDY OBJECTIVES: Obesity is a common feature of narcolepsy. In addition, an increased occurrence of non-insulin dependent diabetes has been reported. So far, it is not known whether glucose metabolism in narcolepsy is disturbed due to, or independently of obesity. DESIGN: Case-control study. SETTING: Sleep medicine clinic at a research institute. PATIENTS: We studied 17 patients with narcolepsy/cataplexy compared to 17 healthy controls matched for age, sex, and body mass index (BMI). INTERVENTIONS: A 75-g oral glucose tolerance test was performed. MEASUREMENTS: Glucose tolerance was determined by computing plasma glucose curve following oral glucose challenge for 240 minutes; insulin sensitivity and insulin secretion by homeostasis model assessment and minimal model analysis. RESULTS: Standard outcome measures and indices of the oral glucose tolerance test did not differ between the patient group and the group of control subjects. CONCLUSIONS: In this study, no clinically relevant pathologic findings in the glucose metabolism of narcoleptic patients compared to weight matched controls were found. Thus, narcolepsy is unlikely to be a risk factor per se for impaired glucose tolerance or diabetes.

Beitinger PA; Fulda S; Dalal MA; Wehrle R; Keckeis M; Wetter TC; Han F; Pollmächer T; Schuld A

2012-02-01

328

Modeling the Glucose Sensor Error.  

UK PubMed Central (United Kingdom)

Continuous glucose monitoring (CGM) sensors are portable devices, employed in the treatment of diabetes, able to measure glucose concentration in the interstitium almost continuously for several days. However, CGM sensors are not as accurate as standard blood glucose (BG) meters. Studies comparing CGM vs BG demonstrated that CGM is affected by distortion due to diffusion processes and by time-varying systematic under/overestimations due to calibrations and sensor drifts. In addition, measurement noise is also present in CGM data. A reliable model of the different components of CGM inaccuracy with respect to BG (briefly, "sensor error") is important in several applications, e.g. design of optimal digital filters for denoising of CGM data, real-time glucose prediction, insulin dosing, and artificial pancreas control algorithms. The aim of this work is to propose an approach to describe CGM sensor error by exploiting n multiple simultaneous CGM recordings. The model of sensor error description includes a model of blood-to-interstitial glucose diffusion process, a linear time-varying model to account for calibration and sensor drift-in-time, and an autoregressive model to describe the additive measurement noise. Model orders and parameters are identified from the n simultaneous CGM sensor recordings and BG references. While the model is applicable to any CGM sensor, here it is used on a database of 36 datasets of type 1 diabetic adults in which n = 4 Dexcom SEVEN Plus CGM time-series and frequent BG references were available simultaneously. Results demonstrates that multiple simultaneous sensor data and proper modeling allow dissecting the sensor error into its different components, distinguishing those related to physiology from those related to technology.

Facchinetti A; Del Favero S; Sparacino G; Castle J; Ward W; Cobelli C

2013-09-01

329

Considerations on the spring analogy  

Science.gov (United States)

This paper presents an investigation on the spring analogy. The spring analogy serves for deformation in a moving boundary problem. First, two different kinds of springs are discussed: the vertex springs and the segment springs. The vertex spring analogy is originally used for smoothing a mesh after mesh generation or refinement. The segment spring analogy is used for deformation of the mesh in a moving boundary problem. The difference between the two methods lies in the equilibrium length of the springs. By means of an analogy to molecular theory, the two theories are generalized into a single theory that covers both. The usual choice of the stiffness of the spring is clarified by the mathematical analysis of a representative one-dimensional configuration. The analysis shows that node collision is prevented when the stiffness is chosen as the inverse of the segment length. The observed similarity between elliptic grid generation and the spring analogy is also investigated. This investigation shows that both methods update the grid point position by a weighted average of the surrounding points in an iterative manner. The weighting functions enforce regularity of the mesh. Based on these considerations, several improvements on the spring analogy are developed. The principle of Saint Venant is circumvented by a boundary correction. The prevention of inversion of triangular elements is improved by semi-torsional springs. The numerical results show the superiority of the segment spring analogy over the vertex one for a small rotation of an NACA0012 mesh. The boundary correction allows for large deformation of the mesh, where the standard spring analogy fails. The final test is performed on a Navier-Stokes mesh. This mesh contains high aspect ratio mesh cells near the boundary. Large deformation of this mesh shows that the semi-torsional spring improvement is imperative to retain the validity of this mesh. Copyright

Blom, Frederic J.

2000-03-01

330

Electrical Analogy to an Atomic Force Microscope  

Directory of Open Access Journals (Sweden)

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.

O. Kucera

2010-01-01

331

Age- and Gender-Specific Reference Intervals for Fasting Blood Glucose and Lipid Levels in School Children Measured With Abbott Architect c8000 Chemistry Analyzer.  

UK PubMed Central (United Kingdom)

Reference intervals for pubertal characteristics are influenced by genetic, geographic, dietary and socioeconomic factors. Therefore, the aim of this study was to establish age-specific reference intervals of glucose and lipid levels among local school children. This was cross-sectional study, conducted among Saudi school children. Fasting blood samples were collected from 2149 children, 1138 (53%) boys and 1011 (47%) girls, aged 6 to 18 years old. Samples were analyzed on the Architect c8000 Chemistry System (Abbott Diagnostics, USA) for glucose, cholesterol, triglycerides, HDL and LDL. Reference intervals were established by nonparametric methods between the 2.5th and 97.5th percentiles. Significant differences were observed between boys and girls for cholesterol and triglycerides levels in all age groups (P < 0.02). Only at age 6-7 years and at adolescents, HDL and LDL levels were found to be significant (P < 0.001). No significant differences were seen in glucose levels except at age 12 to 13 years. Saudi children have comparable serum cholesterol levels than their Western counterparts. This may reflect changing dietary habits and increasing affluence in Saudi Arabia. Increased lipid screening is anticipated, and these reference intervals will aid in the early assessment of cardiovascular and diabetes risk in Saudi pediatric populations.

Tamimi W; Albanyan E; Altwaijri Y; Tamim H; Alhussein F

2012-04-01

332

Age- and Gender-Specific Reference Intervals for Fasting Blood Glucose and Lipid Levels in School Children Measured With Abbott Architect c8000 Chemistry Analyzer.  

Science.gov (United States)

Reference intervals for pubertal characteristics are influenced by genetic, geographic, dietary and socioeconomic factors. Therefore, the aim of this study was to establish age-specific reference intervals of glucose and lipid levels among local school children. This was cross-sectional study, conducted among Saudi school children. Fasting blood samples were collected from 2149 children, 1138 (53%) boys and 1011 (47%) girls, aged 6 to 18 years old. Samples were analyzed on the Architect c8000 Chemistry System (Abbott Diagnostics, USA) for glucose, cholesterol, triglycerides, HDL and LDL. Reference intervals were established by nonparametric methods between the 2.5th and 97.5th percentiles. Significant differences were observed between boys and girls for cholesterol and triglycerides levels in all age groups (P < 0.02). Only at age 6-7 years and at adolescents, HDL and LDL levels were found to be significant (P < 0.001). No significant differences were seen in glucose levels except at age 12 to 13 years. Saudi children have comparable serum cholesterol levels than their Western counterparts. This may reflect changing dietary habits and increasing affluence in Saudi Arabia. Increased lipid screening is anticipated, and these reference intervals will aid in the early assessment of cardiovascular and diabetes risk in Saudi pediatric populations. PMID:23542765

Tamimi, Waleed; Albanyan, Esam; Altwaijri, Yasmin; Tamim, Hani; Alhussein, Fahad

2012-03-08

333

Detection of trace glucose on the surface of a semipermeable membrane using a fluorescently labeled glucose-binding protein: a promising approach to noninvasive glucose monitoring.  

UK PubMed Central (United Kingdom)

BACKGROUND: Our motivation for this study was to develop a noninvasive glucose sensor for low birth weight neonates. We hypothesized that the underdeveloped skin of neonates will allow for the diffusion of glucose to the surface where it can be sampled noninvasively. On further study, we found that measurable amounts of glucose can also be collected on the skin of adults. METHOD: Cellulose acetate dialysis membrane was used as surrogate for preterm neonatal skin. Glucose on the surface was collected by saline-moistened swabs and analyzed with glucose-binding protein (GBP). The saline-moistened swab was also tested in the neonatal intensive care unit. Saline was directly applied on adult skin and collected for analysis with two methods: GBP and high-performance anion-exchange chromatography (HPAEC). RESULTS: The amount of glucose on the membrane surface was found (1) to accumulate with time but gradually level off, (2) to be proportional to the swab dwell time, and (3) the concentration of the glucose solution on the opposite side of the membrane. The swab, however, failed to absorb glucose on neonatal skin. On direct application of saline onto adult skin, we were able to measure by HPAEC and GBP the amount of glucose collected on the surface. Blood glucose appears to track transdermal glucose levels. CONCLUSIONS: We were able to measure trace amounts of glucose on the skin surface that appear to follow blood glucose levels. The present results show modest correlation with blood glucose. Nonetheless, this method may present a noninvasive alternative to tracking glucose trends.

Ge X; Rao G; Kostov Y; Kanjananimmanont S; Viscardi RM; Woo H; Tolosa L

2013-01-01

334

Glucose metabolism in a rat mammary adenocarcinoma  

International Nuclear Information System (INIS)

[en] 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 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

2003-01-01

335

Molecular modeling of fentanyl analogs  

Directory of Open Access Journals (Sweden)

Full Text Available Fentanyl is a highly potent and clinically widely used narcotic analgesic. A large number of its analogs have been synthesized, some of which (sufentanil and alfentanyl) are also in clinical use. Theoretical studies, in recent years, afforded a better understanding of the structure-activity relationships of this class of opiates and allowed insight into the molecular mechanism of the interactions of fentanyl analogs with their receptors. An overview of the current computational techniques for modeling fentanyl analogs, their receptors and ligand-receptor interactions is presented in this paper.

LJILJANA DOSEN-MICOVIC

2004-01-01

336

An Analog LDPC Codec Core  

UK PubMed Central (United Kingdom)

Motivated by the potential to reuse the architecturein place for an analog sum-product decoder,and thus reduce circuit space, we show how an encodermay be constructed for a class of reversible LDPC codes.We review the design of the analog sum-product decoderfor subthreshold CMOS current mode operation and thenshow how the architecture may be reused for encoding.The encoder circuit operates by performing the Jacobimethod for iterative matrix inversion of finite field matrices.We investigate both continuous and discrete timeapproaches. With the addition of only simple componentsinto the sum-product decoder variable nodes, we providea novel design for a time multiplexed analog codec.

David Haley; Chris Winstead

337

Analog filters in nanometer CMOS  

CERN Multimedia

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

Uhrmann, Heimo; Zimmermann, Horst

2013-01-01

338

Development of a Robust Optical Glucose Sensor  

Science.gov (United States)

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

Cote, Gerard Laurence

1990-01-01

339

Glucose Recognition in Vitro Using Fluorescent Spectroscopy  

Energy Technology Data Exchange (ETDEWEB)

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

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

2001-04-25

340

Intraosseous infusion of hypertonic glucose and dopamine.  

UK PubMed Central (United Kingdom)

Intraosseous infusion of drugs for resuscitation and of fluids has been advocated as an alternate emergency technique to intravenous infusion. The reliability of intraosseous infusion of many substances has not been established. Glucose and dopamine hydrochloride are two commonly used emergency drugs in pediatric practice that have not been carefully studied when administered into the bone marrow. In an animal model, we compared the response of an intraosseous injection of hypertonic glucose with that of an intravenous injection of hypertonic glucose. Serum glucose measurements following the injection revealed both routes of administration to be effective. A dopamine infusion was then administered through the bone marrow for 20 minutes. A statistically significant rise in blood pressure was observed two minutes after initiation of the infusion. Intraosseous infusion of hypertonic glucose and dopamine is an effective route by which to administer these medications and is potentially useful in emergency situations in which intravascular access is delayed.

Neish SR; Macon MG; Moore JW; Graeber GM

1988-08-01

 
 
 
 
341

Glucose-Insulin  

Science.gov (United States)

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.

School, Maryland V.

342

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

Science.gov (United States)

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.

Rai, Pratyush; Varadan, Vijay K.

2012-10-01

343

Blood Glucose Levels  

Directory of Open Access Journals (Sweden)

Full Text Available The purpose of this study was to establish a mathematical model which can be used to estimate glucose levels in the blood over time. The equations governing this process were manipulated with the use of techniques such as separation of variables and integration of first order differential equations, which resulted in a function that described the glucose concentration in terms of time. This function was then plotted, which allowed us to find when glucose concentration was at its highest. The model was then used to analyze two cases where the maximum glucose level could not exceed a certain level while the amount of carbohydrates and glycemic index were varied, independently.

Carlos Estela

2011-01-01

344

Pentagastrin analogs containing ?-aminooxy acids  

International Nuclear Information System (INIS)

[en] Two 14C-labelled pentagastrin analogs of different specific radioactivities, containing ?-aminooxy acids, have been synthesised to study their biological effects in the gastro-intestinal tract. (U.K.)

1982-01-01

345

Glucose regulates both glucose transport and the glucose transporter gene expression in a hamster-derived pancreatic beta-cell line (HIT).  

Science.gov (United States)

We studied the effect of chronic exposure to high glucose on the glucose transport regulation in hamster pancreatic Beta cells in permanent culture (HIT). Cells were exposed to either 5.5 mmol/l or 16.7 mmol/l glucose for 48 h and then glucose transport was studied by measuring the (3H)-2-deoxyglucose uptake for 5 and 10 min at 37 degrees C. The 2-deoxyglucose uptake was lower in cells pre-exposed to glucose 16.7 mmol/l for 48 h compared to cells pre-exposed to 5.5 (12.0 +/- 1.6 vs 19.1 +/- 1.2 nmol/0.1 mg after 5 min, and 22.2 +/- 2.6 vs 39.0 +/- 2.9 after 10 min respectively, mean +/- SEM, n = 5, p less than 0.01). In order to investigate the mechanism(s) for glucose impairment of glucose transport, we studied the glucose carrier gene expression in the same cells by Northern and slot-blot analysis. When total RNA was extracted from HIT cells cultured at either 5.5 or 16.7 mmol/l glucose and then hybridized to 32P-labelled cDNA probes for the glucose transporter 1, the glucose transporter 2 and beta-actin, a significant reduction of both glucose transporter 1 (-63.9 +/- 4.1%, mean +/- SEM, n = 3) and glucose transporter 2 (-48.9 +/- 3.2%) mRNA was observed in HIT cells cultured with high glucose. In the same experiments no change of beta-actin mRNA was observed, suggesting that the effect of high glucose was specific on the glucose-transporter mRNAs.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1713870

Purrello, F; Buscema, M; Vetri, M; Vinci, C; Gatta, C; Forte, F; Rabuazzo, A M; Vigneri, R

1991-05-01

346

Glucose regulates both glucose transport and the glucose transporter gene expression in a hamster-derived pancreatic beta-cell line (HIT).  

UK PubMed Central (United Kingdom)

We studied the effect of chronic exposure to high glucose on the glucose transport regulation in hamster pancreatic Beta cells in permanent culture (HIT). Cells were exposed to either 5.5 mmol/l or 16.7 mmol/l glucose for 48 h and then glucose transport was studied by measuring the (3H)-2-deoxyglucose uptake for 5 and 10 min at 37 degrees C. The 2-deoxyglucose uptake was lower in cells pre-exposed to glucose 16.7 mmol/l for 48 h compared to cells pre-exposed to 5.5 (12.0 +/- 1.6 vs 19.1 +/- 1.2 nmol/0.1 mg after 5 min, and 22.2 +/- 2.6 vs 39.0 +/- 2.9 after 10 min respectively, mean +/- SEM, n = 5, p less than 0.01). In order to investigate the mechanism(s) for glucose impairment of glucose transport, we studied the glucose carrier gene expression in the same cells by Northern and slot-blot analysis. When total RNA was extracted from HIT cells cultured at either 5.5 or 16.7 mmol/l glucose and then hybridized to 32P-labelled cDNA probes for the glucose transporter 1, the glucose transporter 2 and beta-actin, a significant reduction of both glucose transporter 1 (-63.9 +/- 4.1%, mean +/- SEM, n = 3) and glucose transporter 2 (-48.9 +/- 3.2%) mRNA was observed in HIT cells cultured with high glucose. In the same experiments no change of beta-actin mRNA was observed, suggesting that the effect of high glucose was specific on the glucose-transporter mRNAs.(ABSTRACT TRUNCATED AT 250 WORDS)

Purrello F; Buscema M; Vetri M; Vinci C; Gatta C; Forte F; Rabuazzo AM; Vigneri R

1991-05-01

347

A large proportion of prediabetes and diabetes goes undiagnosed when only fasting plasma glucose and/or HbA1c are measured in overweight or obese patients.  

UK PubMed Central (United Kingdom)

AIMS: The purposes of the study were to determine the prevalence of unrecognized dysglycaemia in overweight (body mass index [BMI] 25-29.9 kg/m(2)) and obese (BMI ?30 kg/m(2)) patients, to assess the extent to which measures of fasting plasma glucose (FPG) and/or HbA(1c), compared with oral glucose tolerance tests (OGTTs), misdiagnose dysglycaemia, and to determine the factors associated with an isolated abnormal post-OGTT glucose value. METHODS: OGTT was performed and HbA(1c) was measured in 1283 inpatients with BMI scores ? 25 kg/m(2) and no history of dysglycaemia. RESULTS: Prediabetes was found in 257 (20.0%) subjects (197 with impaired glucose tolerance, 29 with impaired fasting glucose, 31 with both) and diabetes in 77 (6.0%), including 22 with FPG ? 7 mmol/L (WHO definition). The sensitivity of FPG >6 mmol/L, FPG >5.5 mmol/L, HbA(1c) ? 6% and the recommendations of the French National Agency of Accreditation and Evaluation in Health Care (ANAES) to identify patients with abnormal OGTTs was 29.9, 41.3, 36.8 and 15.6%, respectively. The factors that were independently associated with diabetes in obese women with FPG <7 mmol/L were age (per 10 years: OR 1.54 [1.00-2.11]; P=0.049) and FPG (OR 6.1 [1.4-30.0]; P=0.014), whereas age (OR 1.26 [1.09-1.44]; P<0.01) and waist circumference (per 10 cm: OR 1.17 [1.01-1.33]; P<0.05) were independently associated with dysglycaemia in obese women with FPG <6.1 mmol/L. CONCLUSION: In overweight and obese patients: dysglycaemia is commonly seen; FPG alone, compared with OGTT, failed to diagnose 70% of dysglycaemia cases; FPG >5.5 mmol/L and HbA(1c) ? 6.0% are not necessarily substitutes for OGTT; and older age and larger waist circumference should be used to select those obese women with normal FPG who might further benefit from OGTTs to diagnose dysglycaemia.

Cosson E; Hamo-Tchatchouang E; Banu I; Nguyen MT; Chiheb S; Ba H; Valensi P

2010-09-01

348

Labelled antibody assays for measuring free triiodothyronine: evaluation and comparison with a labelled analog method. Dosages de la triiodothyronine libre utilisant un anticorps marque: evaluation et comparaison a un dosage avec traceur analogue  

Energy Technology Data Exchange (ETDEWEB)

We evaluated analytically and clinically two new one-step labelled antibody assays for measuring free triiodothyronine (FT3): the first, radiolabelled with [sup 125] I, Amerlex-MAB (MAB) from Kodak diagnostic, and the second, labelled with peroxidase, Enzymum-test FT3 (BM) from Boehringer Mannheim adapted for the Boehringer ES 600 analyzer. The clinical results were compared with those obtained with a radiolabelled analog tracer kit, Amerlex-M (M) from Kodak diagnostic. The latter kit is known to give low FT3 results in sera with low albumin concentrations. Analytical performances of the automated method (BM) were better than those obtained with the manual method (MAB): intra-assay reproducibility (CV<3% vs CV about 5%), inter-assay reproducibility (CV<4% vs CV between 4 and 8%) and mean drift (+1.25% vs -4.3%). The detection limit was low for both kits (<1 pmol/l). In the euthyroid reference group (n = 98) we observed a significant difference between outpatient and hospitalized patient FT3 concentrations as measured with the M kit only. Clinical sensitivity for hyperthyroidism (n = 38) was better for the MAB (92%) than for the BM kit (76%). Specificity in euthyroid L-thyroxine (T4) treated patients (n = 26) was good for both kits (MAB: 92%; BM: 88%) . Hypoalbuminemia (n = 8) decreased FT3 results as follows: M, very significantly; BM, significantly; MAB, only slightly. In patients treated with amiodarone (n = 5), a drug known to lower the metabolic conversion of T4 to T3, the increase of the MAB FT3 results contrasted with the decrease of the BM and M results. In conclusion, results of the two new kits were not strongly influenced by hypoalbuminemia. The MAB results showing lack of decrease in patients with non-thyroidal illness without hypoalbuminemia and in amiodarone-treated patients were unexpected.

Sapin, R.; Gasser, F.; Schlienger, J.L.; Chambron, J. (Centre Hospitalier Universitaire, 67 - Strasbourg (France))

1993-01-01

349

Response variability to glucose facilitation of cognitive enhancement.  

UK PubMed Central (United Kingdom)

Glucose facilitation of cognitive function has been widely reported in previous studies (including our own). However, several studies have also failed to detect glucose facilitation. There is sparsity of research examining the factors that modify the effect of glucose on cognition. The aims of the present study were to (1) demonstrate the previously observed enhancement of cognition through glucose administration and (2) investigate some of the factors that may exert moderating roles on the behavioural response to glucose, including glucose regulation, body composition (BC) and hypothalamic-pituitary-adrenal axis response. A total of twenty-four participants took part in a double-blind, placebo-controlled, randomised, repeated-measures study, which examined the effect of 25 and 60 g glucose compared with placebo on cognitive function. At 1 week before the study commencement, all participants underwent an oral glucose tolerance test. Glucose facilitated performance on tasks of numeric and spatial working memory, verbal declarative memory and speed of recognition. Moderating variables were examined using several indices of glucoregulation and BC. Poorer glucoregulation predicted improved immediate word recall accuracy following the administration of 25 g glucose compared with placebo. Those with better glucoregulation showed performance decrements on word recall accuracy following the administration of 25 g glucose compared with placebo. These findings are in line with accumulating evidence that glucose load may preferentially enhance cognition in those with poorer glucoregulation. Furthermore, the finding that individuals with better glucoregulation may suffer impaired performance following a glucose load is novel and requires further substantiation.

Owen L; Scholey A; Finnegan Y; Sünram-Lea SI

2013-06-01

350

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 months (+45 Gg-O3 month-1).

2003-01-01

351

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

DEFF Research Database (Denmark)

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.

Asmar, Meena; Tangaa, Winnie

2010-01-01

352

Preparation of a modified glucose oxidase reagent for the polarographic determinationof glucose with the Beckman "glucose analyzer".  

UK PubMed Central (United Kingdom)

In this modification, glucose oxidase, 140-180 U/ml, is dissolved in acetate buffer (pH 6):ethanol (96%):glycerol (80:10:10 by vol). Iodine and molybdate are used as catalysts, formaldehyde and mercuric iodide as preservatives, and octanol as an antifoaming agent. The reagent is suitable for use in the Beckman "Glucose Analyzer", it is stable at room temperature for at least six months, it is sensitive, it has a lubricating effect, and its cost is less than a fifth as much as the "Certified" Beckman reagent. It is not suitable for the measurement of glucose in samples containing maltose, cellobiose, gentiobiose, starch, and glycogen.

Fischl J; Federman D; Talmor N

1975-05-01

353

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

Energy Technology Data Exchange (ETDEWEB)

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.

Miller, J.D.; de Leon, M.J.; Ferris, S.H.; Kluger, A.; George, A.E.; Reisberg, B.; Sachs, H.J.; Wolf, A.P.

1987-04-01

354

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

1987-01-01

355

HAPS, a Handy Analog Programming System  

DEFF Research Database (Denmark)

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.

HØjberg, Kristian SØe

1975-01-01

356

Glucose Biosensor Using Selected Indonesian Bacteria  

Directory of Open Access Journals (Sweden)

Full Text Available Microbial glucose sensors have been developed using Escherichia coli bacterial strains from Japan. However, there is interest in developing local bacteria as glucose sensors in Indonesia. In this research, the stability and the potential of a selected number of Indonesian bacteria as glucose biosensors was explored. Results of this study indicate that three of them, E. coli, Bacillus subtilis, and Thermus filiformis exhibit properties of high viability and stability at high temperature (30-60 ºC). Spectrophotometrical and electrochemical measurements showed significant absorbance values and highly stable current features for E. coli as indicated by its high capacity to produce glucose dehydrogenase. E. coli, B. subtilis, and T. filiformis produced currents of 3.25 µA, 0.2 µA, and 0.02 µA respectively, and E. coli also produced a much higher activity of glucose dehydrogenase. Electrochemical measurement using E. coli-modified carbon paste electrode allowed the determination of glucose concentration of up to 20 mM. Therefore, Indonesian E. coli has a high stability and can be used as a glucose biosensor

DYAH ISWANTINI; NOVIK; TRIVADILA

2011-01-01

357

Glucose cycling is markedly enhanced in pancreatic islets of obese hyperglycemic mice  

International Nuclear Information System (INIS)

Pancreatic islets from fed 7-month old lean and obese hyperglycemic mice (ob/ob) were incubated with 3H2O and 5.5 mM or 16.7 mM glucose. Incorporation of 3H into the medium glucose was taken as the measure of glucose-6-P hydrolysis to glucose. Glucose utilization was measured from the yield of 3H2O from [5-3H]glucose. Only 3-4% of the glucose phosphorylated was dephosphorylated by the lean mouse islets irrespective of the glucose concentration. In contrast, the ob/ob mouse islets at 5.5 mM glucose dephosphorylated 18% of the glucose phosphorylated and 30% at 16.7 mM. Thus, the islets of hyperglycemic mice demonstrate increased glucose cycling as compared to the islets of normoglycemic lean mice

1990-01-01

358

Glucose cycling is markedly enhanced in pancreatic islets of obese hyperglycemic mice  

Energy Technology Data Exchange (ETDEWEB)

Pancreatic islets from fed 7-month old lean and obese hyperglycemic mice (ob/ob) were incubated with 3H2O and 5.5 mM or 16.7 mM glucose. Incorporation of 3H into the medium glucose was taken as the measure of glucose-6-P hydrolysis to glucose. Glucose utilization was measured from the yield of 3H2O from (5-3H)glucose. Only 3-4% of the glucose phosphorylated was dephosphorylated by the lean mouse islets irrespective of the glucose concentration. In contrast, the ob/ob mouse islets at 5.5 mM glucose dephosphorylated 18% of the glucose phosphorylated and 30% at 16.7 mM. Thus, the islets of hyperglycemic mice demonstrate increased glucose cycling as compared to the islets of normoglycemic lean mice.

Khan, A.; Chandramouli, V.; Ostenson, C.G.; Berggren, P.O.; Loew, H.L.; Landau, B.R.; Efendic, S. (Karolinska Hospital, Stockholm (Sweden))

1990-05-01

359

Hyperglycemia (High Blood Glucose)  

Medline Plus

Full Text Available ... glucose (sugar). High blood glucose happens when the body has too little insulin or when the body can't use insulin properly. You may also ... enough insulin. If you have type 2, your body may have enough insulin, but it is not ...

360

Continuous glucose monitoring in small animals.  

UK PubMed Central (United Kingdom)

The use of continuous glucose monitoring systems in veterinary patients is summarized and discussed. The current clinical uses in veterinary medicine, including monitoring of hospitalized/sick diabetic patients, long-term monitoring of stable diabetic patients, anesthetized patients, and other patients with altered blood glucose homeostasis are presented. The most important advantage of these systems over intermittent blood glucose measurements is that they facilitate detection of brief periods of hypoglycemia and provide information overnight. The accuracy and advantages/disadvantages compared with traditional monitoring are addressed. The technology involved in the currently available monitoring systems is also discussed.

Surman S; Fleeman L

2013-03-01