On measuring the adequacy of diabetes regulation: comparison of continuously monitored blood glucose patterns with values at selected time points.
Explore the source record for details and available documents.
SEARCH · PubMed Health
Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The performances and the stability of a novel subcutaneous glucose monitoring system have been evaluated. GlucoDay (A. Menarini I.F.R. S.r.l, Florence Italy) is a portable instrument provided with a micro-pump and a biosensor coupled to a microdialysis system capable of recording the subcutaneous glucose level every 3 min. Long and short term stability of the biosensor are discussed and the results of some critical in vitro and in vivo (on rabbits) experiments are reported. A linear response up to 30 mM has been found for in vivo glucose concentration. The sensitivity referred to blood glucose is better than 0.1 mM and the zero current is typically below the equivalent of 0.1 mM. In the accuracy study a mean bias of 2.7 mg/dl and a correlation coefficient equal to 0.9697 have been found. At room temperature, an excellent membrane stability assures good performances up to 6 months from the first use.
A novel concept of a fluorescence affinity hollow fiber sensor for transdermal glucose monitoring is demonstrated. The glucose-sensing principle is based on the competitive reversible binding of a mobile fluorophore-labeled Concanavalin A (Con A) to immobile pendant glucose moites inside of intensely colored Sephadex beads. The highly porous beads (molecular weight cutoff of 200 kDa) were colored with two red dyes, Safranin O and Pararosanilin, selected to block the excitation and spectrum of the fluorophore Alexa488. The sensor consists of the dyed beads and Alexa488-Con A confined inside a sealed, small segment of a hollow fiber dialysis membrane (diameter 0.5 mm, length 0.5 cm, molecular weight cutoff 10 kDa). In the absence of glucose, the majority of Alexa488-Con A resides inside the colored beads bound to fixed glucose. Thus, excitation light at 490 nm impinging on the sensor is strongly absorbed by the dyes, resulting in a drastically reduced fluorescence emission at 520 nm from the Alexa488-Con A residing within the beads. However, when the hollow fiber sensor is exposed to glucose, glucose diffuses through the membrane into the sensor chamber and competitively displaces Alexa 488-Con A molecules from the glucose residues of the Sephadex beads. Thus, Alexa 488-Con A appears in the void space outside of the beads and is fully exposed to the excitation light, and a strong increase in fluorescence emission at 520 nm is measured. At a medium to high loading degree of Sephadex with Alexa488-Con A (10 mg mL(-1) bead suspension), the absolute fluorescence increase due to 20 mM glucose was very large. It exceeded the response of other sensor devices based on FRET by a factor of 50 (Meadows and Schultz Anal. Chim. Acta 1993, 280, 21-30; Russell et al. Anal. Chem. 1999, 71, 3126-3132). The new sensor featured a glucose detection range extending from 0.15 to 100 mM, exhibiting the strongest dynamic signal change from 0.2 to 30 mM. It showed a reasonably fast response time (4-5 min). The combination of all the beneficial sensor features makes this sensor extremely attractive for future in vivo implantation studies for glucose monitoring in subdermal tissue.
Explore the source record for details and available documents.
The need to accurately detect and monitor hyperglycemia in pregnancy is becoming more apparent as the incidence of pregestational and gestational diabetes is increasing, especially among adolescents. The risk of adverse perinatal outcome is markedly worsened when pregnancy is complicated by elevated blood glucose. The appropriate management of both pregestational and gestational diabetes as it relates to blood glucose targets is clear. In the past 5 years, a number of studies have concluded that tight glycemic control throughout pregnancy significantly reduces both fetal and maternal risk. These studies have proposed blood glucose targets between 70 to 120 mg/dL. They have concluded that blood glucose levels should be the basis of moving rapidly to more effective treatments. The key to this approach is the adoption of blood glucose monitoring as an integral part of the treatment regimen. To assure sufficient data on which clinical decisions are made, the type of device, frequency of monitoring, and interpretation of results need to be carefully considered.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
OBJECTIVE: To evaluate the accuracy of a new subcutaneous glucose sensor (Glucoday; A. Menarini Diagnostics) compared with venous blood glucose measurement in type 1 and type 2 diabetic patients. RESEARCH DESIGN: A multicenter study was performed in 70 diabetic patients. A microdialysis fiber was inserted subcutaneously into the periumbelical region and perfused with a buffer solution. Glucose concentrations in the dialysate were then measured every 3 min by the glucose sensor over a 24-h period, during which nine venous blood samples were also collected throughout the day. RESULTS: Both the insertion of the fiber and the wearing of the device were well tolerated by the patients. Subcutaneous glucose levels were well correlated with venous glucose measurements (r = 0.9, P < 0.001) over a wide range (40-400 mg/dl) for up to 24 h, with a single-point calibration. An analysis of 381 data pairs showed a linear relationship between the GlucoDay and serial venous blood glucose levels, and 97% of the data fell in the A and B regions of the error grid analysis. Percentage bias between the GlucoDay and the blood venous levels was -2.0% in the hypoglycemic range (<70 mg/dl), 6.9% in the euglycemic range (70-180 mg/dl), and 11.2% in the hyperglycemic range (>180 mg/dl). CONCLUSIONS: The GlucoDay system demonstrated high reliability and reported values that closely agreed with venous blood glucose measurements. The system was well tolerated and thus constitutes a relatively easy method to monitor glucose excursions in diabetic patients.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Perioperative management of insulinoma may be facilitated by the use of a glucose-controlled insulin infusion system (GCIIS; Biostator System, Miles Laboratories Inc., Elkhart, Ind.). We monitored the blood glucose levels and glucose infusion rates before, during and after surgery in a 35-year-old woman with insulinoma. After an overnight fast, glucose was infused according to a preset program and maintained the blood glucose level at around 50 mg/dl. Depression of the blood glucose level and simultaneous elevation of the glucose infusion rate were noted when the tumor was massaged. A sharp decrease in the glucose infusion rate occurred almost immediately after removal of the tumor. It took about 4 minutes for the blood glucose to go up to a level of 90 mg/dl. These results demonstrate the usefulness of GCIIS not only in maintaining stationary blood glucose, but also in localizing the tumor and in providing evidence of complete removal of the tumor. When the infusion system is programmed appropriately, the glucose infusion rate, as compared to the blood glucose level, reacts more quickly and sensitively to sudden changes in insulin levels.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
For continuous monitoring of glucose concentration in ambulant diabetic patients, a telemetry glucose monitoring system with a needle-type glucose sensor has been developed. The system consists of a sensor transmitter (4 X 6 X 2 cm, 50 g) that converts current signals generated in a needle-type glucose sensor to high-frequency audio signals and a receiver that continuously calculates glucose concentrations from the received audio signals. The noise range of a monitoring record with the telemetry system (0.3 +/- 0.04%, mean +/- SEM) was significantly smaller than that with a wire-connected system, the wearable artificial endocrine pancreas (2.5 +/- 0.3%). Postprandial tissue glucose concentration responded well to the plasma glucose concentration, with a time lag of 5 min. Continuous glucose monitoring of five diabetic subjects for 77 +/- 22 h revealed that a significant correlation existed between the subcutaneous tissue glucose concentration and the plasma glucose concentration measured simultaneously in each patient. These data indicate the usefulness of the telemetry glucose monitoring system in strict glycemic control of diabetic individuals.