Determination of Glucose Levels Using a Functionalized Hydrogel−Optical Fiber Biosensor: Toward Continuous Monitoring of Blood Glucose in Vivo

2009 ◽  
Vol 81 (9) ◽  
pp. 3630-3636 ◽  
Author(s):  
Sven Tierney ◽  
Berit M. Hasle Falch ◽  
Dag Roar Hjelme ◽  
Bjørn Torger Stokke
2010 ◽  
Vol 03 (02) ◽  
pp. 81-90
Author(s):  
NATALJA SKREBOVA EIKJE

Recently introduced horizontal attenuated total reflectance (HATR) Fourier transform infrared (FTIR) spectroscopy for real-time assessment and continuous monitoring of glucose biomolecules in the skin tissue directly on the patients might appear a promising alternative to interpret the activity of interstitial glucose metabolism in vivo by means of evaluating the dynamics of changes of glucose concentrations in interstitial fluid (IF). In the present study, in vivo spectra by ATR-FTIR spectroscopy were obtained post-prandially during a 120–180-minute continuous monitoring in three patients with type 2 diabetes and compared to pre-prandial spectra. In all patients with diabetes interstitial glucose levels at 1030 and 1041 cm-1 reflected the best relationship with blood glucose. The lag time (LT) required for glucose to diffuse from the capillary to epidermal skin tissue was calculated between 0 and 60 minutes at all measured glucose biomolecules. Data showed intra- and inter-subject variations of each glucose biomolecule, pointing to similarities and differences among interstitial glucose metabolism of the patients. Finally, the findings suggest that HATR-FTIR spectroscopy might have the potential for clinical interpretation of activity of glucose metabolism for diagnosis, management, and treatment of patients with diabetes.


Author(s):  
Mohsen Askarbioki ◽  
Mojtaba Mortazavi ◽  
Abdolhamid Amooee ◽  
Saeid Kargar ◽  
Mohammad Afkhami-Ardekani ◽  
...  

Objective: Today, there are various non-invasive techniques available for the determination of blood glucose levels. In this study, the level of blood glucose was determined by developing a new device using near-infrared (NIR) wavelength, glass optical waveguide, and the phenomenon of evanescent waves. Materials and Methods: The body's interstitial fluid has made possible the development of new technology to measure the blood glucose. As a result of contacting the fingertip with the body of the borehole rod, where electromagnetic waves are reflected inside, evanescent waves penetrate from the borehole into the skin and are absorbed by the interstitial fluid. The electromagnetic wave rate absorption at the end of the borehole rod is investigated using a detection photodetector, and its relationship to the people's actual blood glucose level. Following precise optimization and design of the glucose monitoring device, a statistical population of 100 participants with a maximum blood glucose concentration of 200 mg/dL was chosen. Before measurements, participants put their index finger for 30 seconds on the device. Results: According to this experimental study, the values measured by the innovative device with Clark grid analysis were clinically acceptable in scales A and B. The Adjusted Coefficient of Determination of the data was estimated to be 0.9064. Conclusion: For future investigations, researchers are recommended to work with a larger statistical population and use error reduction trends to improve the accuracy and expand the range of measurements.


2019 ◽  
Vol 20 (6) ◽  
pp. 1517 ◽  
Author(s):  
Kai Wang ◽  
Yu Su ◽  
Yuting Liang ◽  
Yanhui Song ◽  
Liping Wang

Type 2 diabetes mellitus (T2DM) is associated with pancreatic β-cell dysfunction which can be induced by oxidative stress. Deuterohemin-βAla-His-Thr-Val-Glu-Lys (DhHP-6) is a microperoxidase mimetic that can scavenge reactive oxygen species (ROS) in vivo. In our previous studies, we demonstrated an increased stability of linear peptides upon their covalent attachment to porphyrins. In this study, we assessed the utility of DhHP-6 as an oral anti-diabetic drug in vitro and in vivo. DhHP-6 showed high resistance to proteolytic degradation in vitro and in vivo. The degraded DhHP-6 product in gastrointestinal (GI) fluid retained the enzymatic activity of DhHP-6, but displayed a higher permeability coefficient. DhHP-6 protected against the cell damage induced by H2O2 and promoted insulin secretion in INS-1 cells. In the T2DM model, DhHP-6 reduced blood glucose levels and facilitated the recovery of blood lipid disorders. DhHP-6 also mitigated both insulin resistance and glucose tolerance. Most importantly, DhHP-6 promoted the recovery of damaged pancreas islets. These findings suggest that DhHP-6 in physiological environments has high stability against enzymatic degradation and maintains enzymatic activity. As DhHP-6 lowered the fasting blood glucose levels of T2DM mice, it thus represents a promising candidate for oral administration and clinical therapy.


mBio ◽  
2020 ◽  
Vol 11 (2) ◽  
Author(s):  
Rebecca J. Marshall ◽  
Pornthida Armart ◽  
Katina D. Hulme ◽  
Keng Yih Chew ◽  
Alexandra C. Brown ◽  
...  

ABSTRACT People with diabetes are two times more likely to die from influenza than people with no underlying medical condition. The mechanisms underlying this susceptibility are poorly understood. In healthy individuals, small and short-lived postprandial peaks in blood glucose levels occur. In diabetes mellitus, these fluctuations become greater and more frequent. This glycemic variability is associated with oxidative stress and hyperinflammation. However, the contribution of glycemic variability to the pathogenesis of influenza A virus (IAV) has not been explored. Here, we used an in vitro model of the pulmonary epithelial-endothelial barrier and novel murine models to investigate the role of glycemic variability in influenza severity. In vitro, a history of glycemic variability significantly increased influenza-driven cell death and destruction of the epithelial-endothelial barrier. In vivo, influenza virus-infected mice with a history of glycemic variability lost significantly more body weight than mice with constant blood glucose levels. This increased disease severity was associated with markers of oxidative stress and hyperinflammation both in vitro and in vivo. Together, these results provide the first indication that glycemic variability may help drive the increased risk of severe influenza in people with diabetes mellitus. IMPORTANCE Every winter, people with diabetes are at increased risk of severe influenza. At present, the mechanisms that cause this increased susceptibility are unclear. Here, we show that the fluctuations in blood glucose levels common in people with diabetes are associated with severe influenza. These data suggest that glycemic stability could become a greater clinical priority for patients with diabetes during outbreaks of influenza.


2009 ◽  
Vol 296 (3) ◽  
pp. E473-E479 ◽  
Author(s):  
Yukihiro Fujita ◽  
Rhonda D. Wideman ◽  
Madeleine Speck ◽  
Ali Asadi ◽  
David S. King ◽  
...  

Glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are released during meals from endocrine cells located in the gut mucosa and stimulate insulin secretion from pancreatic β-cells in a glucose-dependent manner. Although the gut epithelium senses luminal sugars, the mechanism of sugar sensing and its downstream events coupled to the release of the incretin hormones are not clearly elucidated. Recently, it was reported that sucralose, a sweetener that activates the sweet receptors of taste buds, triggers incretin release from a murine enteroendocrine cell line in vitro. We confirmed that immunoreactivity of α-gustducin, a key G-coupled protein involved in taste sensing, is sometimes colocalized with GIP in rat duodenum. We investigated whether secretion of incretins in response to carbohydrates is mediated via taste receptors by feeding rats the sweet-tasting compounds saccharin, acesulfame potassium, d-tryptophan, sucralose, or stevia. Oral gavage of these sweeteners did not reduce the blood glucose excursion to a subsequent intraperitoneal glucose tolerance test. Neither oral sucralose nor oral stevia reduced blood glucose levels in Zucker diabetic fatty rats. Finally, whereas oral glucose increased plasma GIP levels ∼4-fold and GLP-1 levels ∼2.5-fold postadministration, none of the sweeteners tested significantly increased levels of these incretins. Collectively, our findings do not support the concept that release of incretins from enteroendocrine cells is triggered by carbohydrates via a pathway identical to the sensation of “sweet taste” in the tongue.


2004 ◽  
Vol 107 (2) ◽  
pp. 191-196 ◽  
Author(s):  
Aris SIAFARIKAS ◽  
Katie WATTS ◽  
Petra BEYE ◽  
Timothy W. JONES ◽  
Elizabeth A. DAVIS ◽  
...  

The aim of the present study was to investigate the impact of an oral glucose load on circulating insulin and glucose levels and arterial function in healthy non-diabetic subjects. Thirty-nine non-obese, healthy subjects (24 female, 15 male), aged 21.0±1.8 years of age, were randomly assigned to undergo either an OGTT (oral glucose tolerance test; 75 g of glucose) or administration of a placebo. Analyses of lipids, liver function and HbA1c (glycated haemoglobin) at baseline revealed results which were within the standard reference range. Insulin and glucose levels as well as vascular function [FMD (flow-mediated dilation)] were measured at 0, 60 and 120 min. Compared with baseline, the control subjects did not exhibit any significant changes in glucose or insulin levels, whereas, in the OGTT group, blood glucose levels at both 60 (5.4±1.7 mmol/l) and 120 (5.0±1.1 mmol/l) min increased significantly relative to baseline (4.1±0.4 mmol/l; both P<0.001) and, similarly, insulin levels were higher at both 60 (30.1±21.3 m-units/l) and 120 (34.9±23.6 m-units/l) min compared with baseline (4.7±4.3 m-units/l; both P<0.001). Although blood glucose and insulin levels changed, FMD did not significantly differ between time-points or between groups. In summary, despite significantly elevated glucose and insulin concentrations in these subjects, we observed no change in vascular function, suggesting that acute elevations of glucose and insulin within the clinically normal range are not associated with impaired vascular function in vivo.


2019 ◽  
Vol 35 (4) ◽  
pp. 1398-1406
Author(s):  
Sheryl Joyce B. Grijaldo ◽  
Noel S. Quiming ◽  
Marilou G. Nicolas ◽  
Michael Russelle S. Alvarez

Diabetes mellitus, a complex chronic disease that is associated with hyperglycemia (high blood sugar) affects millions of people worldwide. This study evaluated the hypoglycemic activities of male and female Antidesma bunius, commonly known as currant tree or bignay, extracts in alloxan-treated ICR mice. In addition, the effects of the treatments on blood urea nitrogen (BUN) and creatinine levels were determined. Phytochemical screening using standard protocol was performed. Plant extracts (500 mg/kg) were administered orally via gavage for 14 days and fasting blood glucose (FBG) levels were monitored prior to alloxan-induction on the day of alloxan-induction, and on the 3rd, 7th and 14th days of treatment. Sera were collected on the 14th day to measure the BUN and creatinine levels. Phytochemical screening was performed using standard TLC spray tests. All extracts were found to significantly lower FBG levels compared to the positive (glibenclamide 10 mg/kg) and negative (distilled water) controls (One-way ANOVA, p-value<0.0001). The most active extract, aqueous male A. bunius extract, significantly lowered FBG levels by as much as 61.26±17.89% after the 14th day (paired t-test, p-value = 0.0211). Both BUN and creatinine values were found to be significantly different in the treated mice compared to the controls (One-way ANOVA, p-value = 0.0005 and 0.000479, respectively). The BUN level of all mice was still within normal range, unlike with the creatinine level where only the female and male aqueous A. bunius and female ethanolic A. bunius extracts were within normal range. Phytochemical screening showed the presence of saponins, tannins, and polyphenols, phlobatannins, steroids and terpenoids. This study demonstrates the potential of male and female A. bunius leaf extracts to reduce fasting blood glucose levels. Additional work, pertaining to the identification of possible bioactive compounds and establishing the mechanisms thereof, could be performed.


Author(s):  
Aymen Owais Ghauri ◽  
Saeed Ahmad ◽  
Tayyeba Rehman

AbstractBackgroundDiabetes is the one of the leading cause of morbidity and mortality. Traditionally phytotherapy is widely being used for diabetes treatment and highly valued. Citrus colocynthis has known anti-diabetic potential. However, anti-diabetic potential of hydro-ethanolic extract of C. colocynthis pulpy flesh with seeds is not reported yet.MethodsThe extract of C. colocynthis pulpy flesh with seeds was done by maceration method using 70% ethanol. To evaluate anti-diabetic and antioxidant potential of the seeded fruit in vitro, α-glucosidase and DPPH inhibition assays was done, respectively. In vivo study used streptozotocin (STZ) induced diabetes model of rats. Rats were randomized in five groups i. e. normal control, negative control, standard control, C. colocynthis 150 and 300 mg/kg. STZ was administered to all groups except normal control. After wards, plant extract and glibenclamide is continued for 14 days. Blood samples were collected from rat tail vein daily and from Cardiac puncture at the end of study. The blood glucose levels were monitored daily by using one-touch blood glucose monitoring system. The blood glucose level was monitored on 0, 1st, 5th, 8th, 11th, and 14th day of induction.ResultsHydro-ethanolic extract of C. colocynthis pulpy flesh with seeds was able to decolorize DPPH and therefore possess antioxidant potential, continuous administration for 14 days showed a marked decrease in serum glucose levels (p 0.01) it is found to be somewhat less effective as glibenclamide (standard control) (p 0.001). A time-dependent decrease in blood glucose levels was observed (351.3 ± 4 to 258 m/kg).ConclusionHydro-ethanolic extract of C. colocynthis pulpy flesh with seeds lowered the serum triglyceride and cholesterol levels in diabetic rats significantly as compared to negative control. The hypoglycemic effect of hydro-ethanolic extract of C. colocynthis pulpy flesh with seeds is may be due to α-glucosidase inhibition potential.


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