Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0011849 (diabetes)
 277,896 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Sixty-four children with type 1 diabetes (33 girls and 31 boys with a mean age of 11 1/4 years) were studied in order to ascertain whether urine sugar measurements performed by the patients or their parents can provide adequate monitoring of treatment. The results of two home-testing methods for urine glucose were compared with subsequent glucose dehydrogenase assays in the laboratory. Over the range from 0 to 5 g/dl the results of home testing disagreed with the laboratory checks by an average of one concentration grade, and displayed wide scatter. Only in the concentration range of 0.5 g/dl were there differences between the nonspecific reduction test (Clinitest) and the specific enzymatic assay. Glucose concentrations in urine specimens passed at 7 am, 12 noon and 6 pm (home testing) were compared with blood glucose concentrations checked at the same times. Correlation was not very close (correlation coefficients between 0.3 and 0.64). Correlation between pooled urine collections and 24 hour blood sugar profiles was equally poor (0.5-0.6). The author concludes that urine sugar testing is unsatisfactory for home monitoring of children with diabetes and the results are inadequate for diagnostic or therapeutic purposes.
 ...
PMID:[Urine glucose testing in children with diabetes mellitus--obsolete as a daily control measure?]. 259 96

The capillary blood glucose (CBG) estimated by some of the most frequent users of portable reflectance meters (PRMs) were assessed using blood applied to Whatman 31 ET filter paper at the time of the performance of the CBG. The performance of nursing staff on hospital wards, community groups screened for diabetes and patients exercising self monitoring of blood glucose (SMBG) at home were evaluated. The glucose was extracted from the filter paper with 5% trichloroacetic acid (TCA) and analyzed within 5 days of collection on a Technicon RA-1000 analyzer using Merck glucose dehydrogenase reagents. Of the 1255 samples collected, 385 were rejected due to inadequate sample collection, and a further 196 were rejected as they were received more than 5 days after collection, the time interval allowed for glucose stability on the filter paper. The CBGs obtained by the nursing staff were 2.2 - 17.1 mmol/l with a mean of 7.6 mmol/l; the community screened subjects CBGs were 1.5 -22.4 mmol/l with a mean of 5.2 mmol/l; and the SMBG users at home obtained CBGs of 1.0 - 15.1 mmol/l with a mean of 5.07 mmol/l. Of the 674 samples analyzed only 36.6% were within 10% of the laboratory blotting paper glucose (BPG) result. An alarming 35.8% exceeded 20% and 10.2% exceeded 50% of the BPG result. The correlation of all 3 groups with the BPG obtained by the laboratory were similar (correlation coefficient = 0.86, 0.85, 0.87 respectively).(ABSTRACT TRUNCATED AT 250 WORDS)
Diabetes Res 1987 Mar
PMID:Quality control of portable reflectance meter capillary blood glucose results by measurement of glucose on filter paper. 360 69

Miniature PO2 and pH sensors can be used in combination with enzymatic catalysts such as glucose oxidase and glucose dehydrogenase as the basis for the development of a small glucose sensor. The applications of microelectronic techniques such as photolithography techniques and thick- and thin-film metallization are novel approaches in fabricating highly uniform and reproducible sensors that are relatively simple to calibrate and operate.
Diabetes Care
PMID:Fabrication of miniature PO2 and pH sensors using microelectronic techniques. 717 96

Genetic and immunological factors may play a role as possible causes for gestational diabetes. Autoantibodies to glutamic acid decarboxylase (GADA) are frequently found in patients with insulin dependent diabetes, but have only rarely been analyzed with regard to the carbohydrate tolerance in pregnancy. An oral glucose tolerance test (oGTT) with 75 g glucose was performed in 110 pregnant patients during the third trimenon. Glucose (glucose dehydrogenase method) and insulin (RIA) concentrations were measured after 0, 30, 60, 120, and 180 minutes. Patients were divided into five groups of increasing glucose intolerance based on the highest glucose concentration reached during the oGTT. GADA were measured using a quantitative enzyme-immunoassay. Only a single patient showed pathologically elevated GADA, and her oGTT results were within the normal range. GADA in subjects with normal pathological glucose tolerance showed no significant difference (276.6 +/- 151.6 and 263.0 +/- 107.1 mU/ml respectively). There was a tendency of positive correlations between high GADA-levels and higher concentrations of insulin as well as an increased insulin-glucose-index. These findings suggest that pregnant patients with higher GADA-levels may have an increased insulin resistance. In conclusion, the concentration of GADA was not found to be helpful in evaluating the current metabolic situation in gestational diabetes. It remains unclear whether elevated GADA during pregnancy have a prognostic value regarding the manifestation of overt diabetes mellitus later in life.
 ...
PMID:[Glutamic acid decarboxylase autoantibody concentration and glucose tolerance in late pregnancy]. 1052 73

The monitoring and management of blood glucose levels are key components for maintaining the health of people with diabetes. Traditionally, glucose monitoring has been based on indirect detection using electrochemistry and enzymes such as glucose oxidase or glucose dehydrogenase. Here, we demonstrate direct detection of glucose using a surface plasmon resonance (SPR) biosensor. By site-specifically and covalently attaching a known receptor for glucose, the glucose/galactose-binding protein (GGBP), to the SPR surface, we were able to detect glucose binding and determine equilibrium binding constants. The site-specific coupling was accomplished by mutation of single amino acids on GGBP to cysteine and subsequent thiol conjugation. The resulting SPR surfaces had glucose-specific binding properties consistent with known properties of GGBP. Further modifications were introduced to weaken GGBP-binding affinity to more closely match physiologically relevant glucose concentrations (1-30 mM). One protein with a response close to this glucose range was identified, the GGBP triple mutant E149C, A213S, L238S with an equilibrium dissociation constant of 0.5mM. These results suggest that biosensors for direct glucose detection based on SPR or similar refractive detection methods, if miniaturized, have the potential for development as continuous glucose monitoring devices.
 ...
PMID:Direct detection of glucose by surface plasmon resonance with bacterial glucose/galactose-binding protein. 1470 82

There is an urgent need to develop technology for continuous in vivo glucose monitoring in subjects with diabetes mellitus. Problems with existing devices based on electrochemistry have encouraged alternative approaches to glucose sensing in recent years, and those based on fluorescence intensity and lifetime have special advantages, including sensitivity and the potential for non-invasive measurement when near-infrared light is used. Several receptors have been employed to detect glucose in fluorescence sensors, and these include the lectin concanavalin A (Con A), enzymes such as glucose oxidase, glucose dehydrogenase and hexokinase/glucokinase, bacterial glucose-binding protein, and boronic acid derivatives (which bind the diols of sugars). Techniques include measuring changes in fluorescence resonance energy transfer (FRET) between a fluorescent donor and an acceptor either within a protein which undergoes glucose-induced changes in conformation or because of competitive displacement; measurement of glucose-induced changes in intrinsic fluorescence of enzymes (e.g. due to tryptophan residues in hexokinase) or extrinsic fluorophores (e.g. using environmentally sensitive fluorophores to signal protein conformation). Non-invasive glucose monitoring can be accomplished by measurement of cell autofluorescence due to NAD(P)H, and fluorescent markers of mitochondrial metabolism can signal changes in extracellular glucose concentration. Here we review the principles of operation, context and current status of the various approaches to fluorescence-based glucose sensing.
 ...
PMID:Fluorescence-based glucose sensors. 1585 25

Patients on chronic ambulant peritoneal dialysis (CAPD) are increasingly likely to be treated with a new solution of corn starch-derived glucose polymers called icodextrin. This solution involves a very low carbohydrate absorption leading to a better glycemic control in diabetic patients. However these glucose polymers pass to the blood and are metabolized to oligosaccharids which interfere with blood glucose in distinct capillary glucose analyzers leading to overestimation of glycemia. We assessed the accuracy of glucose measurements with the three most commonly used glucose analyzers compared to venous plasma glucose measurement at our institution in 8 patients (4 patients with type 2 diabetes) on CAPD using icodextrin. Glycemia was measured simultaneously in plasma of venous blood using a reference laboratory method and in capillary blood using Accu-Chek sensor (Rotkreuz, Switzerland) (glucose dehydrogenase method), Glucotrend 2 (Rotkreuz, Switzerland) (glucose-dye-oxyreductase method) and Ascensia elite (Zurich, Switzerland) (glucose oxidase method) glucose analyzers. Only glucose readings with Ascensia elite correspond correctly with venous plasma glucose results (+0.3 mmol/l; n. s.), whereas glycemia was significantly overestimated by Accu-Chek sensor (+4.3 mmol/l; p<0.0001) and Glucotrend 2 glucose analyzers (+3.7 mmol/l; p<0.0001). Thus we conclude that distinct glucose analyzers overestimate real blood glucose concentration and are not suitable for monitoring glycemia in patients on CAPD with icodextrin. On the basis of our results, these patients should use glucose analyzers using glucose oxidase methods. All glucose analyzers should be cross-checked with a laboratory reference method before the application in patients on CAPD with icodextrin is recommended.
Exp Clin Endocrinol Diabetes 2006 Mar
PMID:Inaccurate self-monitoring of blood glucose readings in patients on chronic ambulatory peritoneal dialysis with icodextrin. 1663 78

A new self-calibrating blood glucose monitoring system (BGMS) was evaluated in a series of clinical studies with both ambulatory subjects and with hospitalized patients. The new BGMS requires a 0.6microL sample volume, provides results in 15s, and uses a glucose dehydrogenase chemistry that is oxygen independent. In the first study, Ascensia Contour meters calibrated to whole blood were tested by health care professionals (HCP) and lay users at two clinical sites. Both HCPs and lay users obtained results that fulfilled the ISO 15197:2003 criteria that 95% of self-monitoring blood glucose (SMBG) measurements should fall within +/-20% (for blood glucose (BG) concentrations> or =4.2mmol/L or +/-0.83mmol/L for BG concentrations<4.2mmol/L) of the laboratory value. Lay users and HCPs obtained 97.2 and 96.7% of glucose results within ISO criteria, respectively. In a second study, HCPs assayed blood samples from patients at the hospital bedside using meters calibrated to give whole blood glucose and meters calibrated to give plasma glucose results. Overall, 94.7% of the measurements met the ISO 15197:2003 criteria. Most lay subjects rated the BGMS as either excellent or very good in a questionnaire, and were able to use it properly without training. These findings indicate that this new BGMS is a convenient and accurate instrument system suitable for both hospital bedside use by HCPs and for SMBG by people who routinely monitor their blood glucose.
Diabetes Res Clin Pract 2006 Oct
PMID:Evaluation of a new blood glucose monitoring system with auto-calibration for home and hospital bedside use. 1664 56

A 45-year-old female diabetes-mellitus patient on peritoneal dialysis was admitted because of vertigo. During her stay in hospital she developed a comatose condition with abnormal head posture and deviation ofthe eyes to the left. Capillary blood from the fingertip showed a glucose value of 15.4 mmol/l. However, the automatically obtained glucose value delivered with a blood-gas analysis was found to be 1.2 mmol/l. The neurological state of the patient normalised fully after intravenous glucose administration. The glucose values were falsely elevated because the patient used a peritoneal dialysis fluid at night which contained icodextrin as an osmotic agent. Metabolites of icodextrin can influence blood-glucose measurements taken using analyzers that depend on the enzyme glucose dehydrogenase. To prevent potentially life-threatening situations, the use of an adequate glucose meter is of paramount importance.
 ...
PMID:[Hypoglycaemic coma due to falsely elevated glucose values in a patient with diabetes mellitus and peritoneal dialysis]. 1707 69

Diabetes devastates lives and burdens society. Hypoglycemic (low glucose) episodes cause blackouts, and severe ones are life-threatening. Periods of hyperglycemia (high glucose) cause circulatory disease, stroke, amputations, blindness, kidney failure and nerve degeneration. In this Account, we describe the founding of TheraSense, now a major part of Abbott Diabetes Care, and the development of two products that have improved the lives of people with diabetes. The first, a virtually painless microcoulometer (300 nL volume), the FreeStyle blood glucose monitoring system, was approved by the FDA and became available in 2000. In 2009, this system was used in more than one billion blood assays. The second, the enzyme-wiring based, subcutaneously-implanted FreeStyle Navigator continuous glucose monitoring system, was approved by the FDA and became available in the United States in 2008. The strips of the FreeStyle blood glucose monitoring system comprise a printed parallel plate coulometer, with a 50 microm gap between two facing printed electrodes, a carbon electrode and a Ag/AgCl electrode. The volume of blood between the facing plates is accurately controlled. The glucose is electrooxidized through catalysis by a glucose dehydrogenase (GDH) and an Os(2+/3+) redox mediator, which is reduced by the glucose-reduced enzyme and is electrooxidized on the carbon electrode. Initially the system used pyrroloquinoline quinone (PQQ)-dependent GDH but now uses flavin adenine dinucleotide (FAD)-dependent GDH. Because the facing electrodes are separated by such a small distance, shuttling of electrons by the redox couple could interfere with the coulometric assay. However, the Os(2+/3+) redox mediator is selected to have a substantially negative formal potential, between 0.0 and -0.2 V, versus that of the facing Ag/AgCl electrode. This makes the flow of a shuttling current between the two electrodes virtually impossible because the oxidized Os(3+) complex cannot be appreciably reduced at the more positively poised Ag/AgCl electrode. The FreeStyle Navigator continuous glucose monitoring system uses a subcutaneously implanted miniature plastic sensor connected to a transmitter to measure glycemia amperometrically and sends the information to a PDA-like device every minute. The sensor consists of a narrow (0.6 mm wide) plastic substrate on which carbon-working, Ag/AgCl reference, and carbon counter electrodes are printed in a stacked geometry. The active wired enzyme sensing layer covers only about 0.1 mm(2) of the working electrode and is overlaid by a flux-limiting membrane. It resides at about 5 mm depth in the subcutaneous adipose tissue and monitors glucose concentrations over the range 20-500 mg/dL. Its core component, a miniature, disposable, amperometric glucose sensor, has an electrooxidation catalyst made from a crosslinked adduct of glucose oxidase (GOx) and a GOx wiring redox hydrogel containing a polymer-bound Os(2+/3+) complex. Because of the selectivity of the catalyst for glucose, very little current flows in the absence of glucose. That feature, either alone or in combination with other features of the sensor, facilitates the one-point calibration of the system. The sensor is implanted subcutaneously and replaced by the patient after 5 days use with minimal pain. The wearer does not feel its presence under the skin.
 ...
PMID:Electrochemistry in diabetes management. 2038 99


1 2 Next >>