scholarly journals Optimization of Differential pH Sensors Device Operation Conditions to Be Used in Quantification of Low Glucose Concentration

2011 ◽  
Vol 3 (2) ◽  
Author(s):  
Najah Mahdi Mohammed Al-mhanna
Keyword(s):  
Glucose Concentration ◽  
Ph Sensors ◽  
Operation Conditions ◽  
Low Glucose ◽  
Device Operation

scholarly journals Intraperitoneal Microdialysis as a Monitoring Method in the Intensive Care Unit

2014 ◽  
Vol 99 (6) ◽  
pp. 729-733 ◽  
Author(s):  
Tasiopoulos Konstantinos ◽  
Komnos Apostolos ◽  
Paraforos Georgios ◽  
Tepetes Konstantinos
Keyword(s):  
Intensive Care Unit ◽  
Intensive Care ◽  
Glucose Concentration ◽  
Repeated Measures ◽  
Statistical Significance ◽  
Monitoring Method ◽  
P Values ◽  
Repeated Measures Analysis ◽  
Low Glucose ◽  
Surgical Condition

Abstract Studies on surgical patients provide some evidence of prompt detection of enteric ischemia with microdialysis. The purpose of the study was to measure intraperitoneal microdialysis values (glucose, glycerol, pyruvate, and lactate) in patients hospitalized in an intensive care unit (ICU) with an underlying abdominal surgical condition and to correlate these values with patients' outcomes. Twenty-one patients, 10 female, were enrolled in the study. The intraperitoneal metabolite values were measured for 3 consecutive days, starting from the first day of ICU hospitalization. Descriptive and inferential statistics were performed. The t-test, repeated measures analysis, Holm's test, and a logistic regression model were applied. Level of statistical significance was set at P = 0.05. Mean age of participants was 68.10 ± 8.02 years old. Survivors exhibited statistically significantly higher glucose values on day 3 (6.61 ± 2.01 against 3.67 ± 1.62; P = 0.002). Mean lactate/ pyruvate (L/P) values were above 20 (35.35 ± 27.11). All non-survivors had a mean three day L/P values greater than 25.94. Low L/P values were related to increased survival possibilities. High microdialysis glucose concentration, high L/P ratio and low glucose concentration were the major findings during the first three ICU hospitalization days in non-survivors. Intraperitoneal microdialysis may serve as a useful tool in understanding enteric ischemia pathophysiology.

Effect of perfusate glucose concentration on rat lung glycolysis.

1979 ◽  
Vol 236 (3) ◽  
pp. E229 ◽  
Author(s):  
J S Kerr ◽  
N J Baker ◽  
D J Bassett ◽  
A B Fisher
Keyword(s):  
Glucose Concentration ◽  
Glucose Utilization ◽  
Glycogen Content ◽  
Lactate Production ◽  
Bicarbonate Buffer ◽  
Exogenous Glucose ◽  
Low Glucose ◽  
The Difference ◽  
Endogenous Substrates ◽  
The Relationship

We investigated the relationship between perfusate concentration of glucose and its utilization and lactate production derived from exogenous glucose and from metabolism of endogenous substrates. Isolated rat lungs were ventilated with 5% CO2 in air and perfused for 100 min with Krebs-Ringer bicarbonate buffer containing 3% bovine serum albumin, 10(-2) U/ml insulin, [U-14C]glucose and [5-3H]glucose. Glucose utilization, total lactate production, [14C]lactate production, and 3H2O production were measured. The apparent Km and Vmax for glucose utilization were 3.4 mM and 72.5 mumol/g dry wt per h, respectively. Lactate production from endogenous substrates, calculated as the difference between total and [14C]lactate, was 37.6 +/- 2.2 mumol/g dry wt (n = 36); it was unaffected by perfusate glucose concentration and by omission of insulin, but increased threefold with anoxia. Lactate production from 1.5 mM glucose was significantly less (P less than 0.02) with insulin omitted. Glycogen content was unchanged during perfusion without glucose. These results suggest that: 1) protein catabolism contributes to lung lactate production; 2) glucose utilization by lung is not maximal at resting physiological glucose concentrations; and 3) insulin is required at low glucose concentrations for maximal glycolytic rates.

Effect of glucose and oxygen deprivation on heme oxygenase expression in human chorionic villi explants and immortalized trophoblast cells

2003 ◽  
Vol 285 (6) ◽  
pp. R1453-R1460 ◽  
Author(s):  
S. D. Appleton ◽  
G. E. Lash ◽  
G. S. Marks ◽  
K. Nakatsu ◽  
J. F. Brien ◽  
...  
Keyword(s):  
Enzymatic Activity ◽  
Protein Content ◽  
Heme Oxygenase ◽  
Glucose Concentration ◽  
Placental Tissue ◽  
Glucose Deprivation ◽  
First Trimester ◽  
Trophoblast Cells ◽  
Chorionic Villi ◽  
Low Glucose

Although hypoxia induces heme oxygenase (HO)-1 mRNA and protein expression in many cell types, recent studies in our laboratory using human placental tissue have shown that a preexposure to hypoxia does not affect subsequent HO enzymatic activity for optimized assay conditions (20% O2; 0.5 mM NADPH; 25 μM methemalbumin) or HO-1 protein content. One of the consequences of impaired blood flow is glucose deprivation, which has been shown to be an inducer of HO-1 expression in HepG2 hepatoma cells. The objective of the present study was to test the effects of a 24-h preexposure to glucose-deprived medium, in 0.5 or 20% O2, on HO protein content and enzymatic activity in isolated chorionic villi and immortalized HTR-8/SVneo first-trimester trophoblast cells. HO protein content was determined by Western blot analysis, and microsomal HO enzymatic activity was measured by assessment of the rate of CO formation. HO enzymatic activity was increased ( P < 0.05) in both placental models after 24-h preexposure to glucose-deficient medium in 0.5 or 20% O2. Preexposure (24 h) in a combination of low O2 and low glucose concentrations decreased the protein content of the HO-1 isoform by 59.6% ( P < 0.05), whereas preexposure (24 h) to low glucose concentration alone increased HO-2 content by 28.2% in chorionic villi explants ( P < 0.05). In this preparation, HO enzymatic activity correlated with HO-2 protein content ( r = 0.825). However, there was no correlation between HO-2 protein content and HO enzymatic activity in HTR-8/SVneo trophoblast cells preexposed to 0.5% O2 and low glucose concentration for 24 h. These findings indicate that the regulation of HO expression in the human placenta is a complex process that depends, at least in part, on local glucose and oxygen concentrations.

Tailoring of Stress Development in MEMS Packaging Systems

2002 ◽  
Vol 741 ◽  
Author(s):  
Satyajit S. Walwadkar ◽  
Junghyun Cho ◽  
P.W. Farrell ◽  
Lawrence E. Felton
Keyword(s):  
Microelectromechanical Systems ◽  
Inertial Sensors ◽  
Thermal Exposure ◽  
Origin And Evolution ◽  
Mems Packaging ◽  
Operation Conditions ◽  
Die Attach ◽  
Device Operation ◽  
Different Levels ◽  
Good Agreement

ABSTRACTA better understanding of the origin and evolution of the stresses is a crucial step in improving reliability of packaging systems for microelectromechanical systems (MEMS). Given its importance, we examine the stresses developed in hermetically packaged MEMS inertial sensors. For this purpose, an optical surface profilometer is employed to assess the stresses by measuring the curvature of dummy silicon dies (3.5×3.5 mm2) assembled in different types of packages and die attach adhesives. We also explore a temporal evolution of stresses during thermal exposure of the test packages in an effort to emulate actual packaging processes and device operation conditions. The result shows different levels of stresses generated from various adhesives and package types, and also a stress evolution during packaging processes. The mechanical stress data also show a good agreement with MEMS performance data obtained from actual accelerometers. Therefore, the stress data will not only be useful in better understanding performance of MEMS packages, but the testing protocol can also provide a diagnostic tool for very small packaging systems.

scholarly journals Glucose transport of Escherichia coli growing in glucose-limited continuous culture

1979 ◽  
Vol 178 (1) ◽  
pp. 97-101 ◽  
Author(s):  
I S Hunter ◽  
H L Kornberg
Keyword(s):  
Escherichia Coli ◽  
Continuous Culture ◽  
Glucose Concentration ◽  
Wild Type ◽  
Phosphotransferase System ◽  
Glucose Limitation ◽  
Low Glucose ◽  
Rate Limiting ◽  
Excess Glucose ◽  
Stimulation Of

Dilute cultures of wild-type Escherichia coli K12 and of derivatives impaired in one or other Enzyme-II component of the glucose phosphotransferase system were grown in continuous culture under glucose limitation. Cells harvested from the chemostat took up [U-14C]glucose from 0.1 mM solutions at rates directly related to the rates at which those cells had grown; the activity of the phosphotransferase system in those cells, rendered permeable with optimal accounts of toluene, parallels the ability of the cells to take up glucose. The capacity of these systems was rate-limiting for growth under the negligibly low glucose concentration in the chemostat, but was adequate to account for the stimulation of respiration observed when the cells were presented suddenly with excess glucose.

Adaptive Control at Low Glucose Concentration of HEK-293 Cell Serum-Free Cultures

1999 ◽  
Vol 15 (4) ◽  
pp. 608-616 ◽  
Author(s):  
P. Siegwart ◽  
J. Cote ◽  
K. Male ◽  
J.H.T. Luong ◽  
M. Perrier ◽  
...  
Keyword(s):  
Adaptive Control ◽  
Glucose Concentration ◽  
Hek 293 ◽  
Serum Free ◽  
Low Glucose

scholarly journals Effect of Substrate Feeding Concentration on Initial Biofilm Development in Anaerobic Hybrid Reactor

2017 ◽  
Vol 20 (3&4) ◽  
pp. 361-372
Author(s):  
B. Suraraksa ◽  
A. Nopharatana ◽  
P. Chaiprasert ◽  
S. Bhumiratana ◽  
M. Tanticharoen
Keyword(s):  
High Glucose ◽  
Glucose Concentration ◽  
Substrate Concentration ◽  
Early Stage ◽  
Hybrid Reactor ◽  
High Glucose Concentration ◽  
High Substrate Concentration ◽  
High Substrate ◽  
Low Glucose ◽  
Biofilm Development

To elucidate the effect of substrate concentration on biofilm development, glucose concentrations of 500 and 1,000 mg/L were used.  At an early stage, biofilm development at both concentrations was not significantly different (P=0.621).  After removing suspended biomass at 24 operational hours, the biofilm development at high substrate concentration was higher than at lower concentration.  At 72 operational hours, the amounts of attached biomass at low and high glucose feeding were 9.04±1.17 and 28.58±2.72 g VSS/m2, respectively.  The activities of acidogens, acetogens, and methanogens at the low glucose concentration were 0.334, 0.016 and 0.003 g COD/g VSS/h, and those at the high glucose concentration were 0.145, 0.003 and 0.001 g COD/g VSS/h, respectively.  Moreover, the ratio of methanogenic activity at low glucose concentration was higher than at high glucose concentration.  The glucose utilization at low and high feeding concentrations was 33% and 27%, respectively.  These results indicated that rapid biofilm development by using high substrate concentration would be less beneficial if unbalance of methanogenic ratio was found in biofilm.

Glucose consumption of vascular cell types in culture; toward optimization of experimental conditions

2021 ◽  
Author(s):  
Keiichi Torimoto ◽  
Keisuke Okuno ◽  
Ryohei Kuroda ◽  
No'Ad Shanas ◽  
Stephanie M. Cicalese ◽  
...  
Keyword(s):  
High Glucose ◽  
Glucose Concentration ◽  
Regulatory Protein ◽  
Glucose Consumption ◽  
Cell Types ◽  
Hexokinase Ii ◽  
Experimental Conditions ◽  
Vascular Cell ◽  
Adventitial Fibroblasts ◽  
Low Glucose

In this study, we have looked for an optimum media glucose concentration and compared glucose consumption in three vascular cell types, endothelial cells (EC), vascular smooth muscle cells (VSMC) and adventitial fibroblasts (AF) with or without angiotensin II (AngII) stimulation. In a sub-confluent 6-well experiment in 1 mL DMEM with a standard low (100 mg/dL), a standard high (450 mg/dL), or a mixed middle (275 mg/dL) glucose concentration, steady and significant glucose consumption was observed in all cell types. After 48-hour incubation, media that contained low glucose was reduced to almost 0 mg/dL, media that contained high glucose remained significantly higher at ~275 mg/dL, and media that contained middle glucose remained closer to physiological range. AngII treatment enhanced glucose consumption in AF and VSMC but not in EC. Enhanced extracellular acidification rate by AngII was also observed in AF. In AF, AngII induction of target proteins at 48 hours varied depending on the glucose concentration used. In low glucose media induction of glucose regulatory protein 78 or hexokinase II was highest, whereas induction of VCAM-1 was lowest. Utilization of specific inhibitors further suggest essential roles of AT1 receptor and glycolysis in AngII-induced fibroblast activation. Overall, the present study demonstrates a high risk of hypo- or hyperglycemic conditions when standard low or high glucose media is used with vascular cells. Moreover, these conditions may significantly alter experimental outcomes. Media glucose concentration should be monitored during any culture experiments and utilization of middle glucose media is recommended for all vascular cell types.

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