Changes In Glucose Concentration Research Articles

The effect of some statins on Glucose blood levels in experimental animals

Statins are HMG-CoA reductase inhibitors, which are widely used as cholesterol-lowering drugs to treat hypercholesterolemia. They are essential in the primary and secondary prevention of CVDs. They are also well tolerated drugs, although there might be some adverse reactions, particularly the new onset of T2DM. As DM, impaired fasting glucose and pre-diabetes are significant cardiovascular risk factors, the purpose of the current work was to study the effects of some statins (pravastatin and pitavastatin) on glucose blood levels in non-diabetic and diabetic mice. Non-diabetic and diabetic female albino mice were treated with pravastatin and pitavastatin once a day for 28 days. Diabetes was induced using alloxan monohydrate (160mg/Kg body weight). Both body weight and fasting blood glucose were measured. IGTT was performed before and after drug treatment. There was no significant statistical difference in body weight between groups before and after 4 weeks of treatment. In addition, we didn’t find any marked change in fasting glucose concentrations of the treated groups in comparison to the control groups of each mouse model. No statistically significant difference was reported when we compared glucose values of IGTT before treatment and at the end of the study for each of the non-diabetic groups. Furthermore, no significant difference was recognized in IGTT results within the diabetic groups before and after drug administration, except for the pravastatin group, which showed a significant decrease in minute 30 of IGTT. We concluded that pravastatin may improve glucose intolerance in diabetic patients. Pitavastatin also may not affect the glycemic status in both models. Both drugs didn’t adversely affect fasting glucose levels in the two mouse models. These findings suggest that pravastatin and pitavastatin may be considered as good choices for patients with DM and hypercholesterolemia.

Glucose Stimulates Glial Cell Line-Derived Neurotrophic Factor Gene Expression in Microglia through a GLUT5-Independent Mechanism.

Feeding-regulating neurotrophic factors are expressed in both neurons and glial cells. However, nutritional regulation of anorexigenic glial cell line-derived neurotrophic factor (GDNF) and orexigenic mesencephalic astrocyte-derived neurotrophic factor (MANF) expression in specific cell types remains poorly understood. Hypothalamic glucose sensing plays a critical role in the regulation of food intake. It has been theorized that local glucose concentration modulates microglial activity partially via glucose transporter 5 (GLUT5). We hypothesized that an increased local glucose concentration stimulates GDNF expression while inhibiting MANF expression in the hypothalamus and microglia via GLUT5. The present study investigated the effect of glucose on Gdnf and Manf mRNA expression in the mouse hypothalamus and murine microglial cell line SIM-A9. Intracerebroventricular glucose treatment significantly increased Gdnf mRNA levels in the hypothalamus without altering Manf mRNA levels. Exposure to high glucose caused a significant increase in Gdnf mRNA expression and a time-dependent change in Manf mRNA expression in SIM-A9 cells. GLUT5 inhibitor treatment did not block glucose-induced Gdnf mRNA expression in these cells. These findings suggest that microglia are responsive to changes in the local glucose concentration and increased local glucose availability stimulates the expression of microglial GNDF through a GLUT5-independent mechanism, contributing to glucose-induced feeding suppression.

Effect of feeding calcium gluconate embedded in a hydrogenated fat matrix on feed intake, gastrointestinal fermentation and morphology, intestinal brush border enzyme activity and blood metabolites in growing lambs.

Gluconate salts have been identified as a butyrate precursor when fed to non-ruminant species and may increase the butyrate concentration in the large intestine supporting gastrointestinal health and development. The objective of this study was to evaluate the dose response of hydrogenated fat-embedded calcium gluconate (HFCG) on performance and gastrointestinal tract (GIT) development in growing lambs. Thirty-two wether lambs were used in a randomized complete block design and assigned to 1 of 4 treatments differing in the inclusion of HFCG: 0.0% (CON), 0.075% (LOW), 0.30% (MED), and 0.60% of the diet (HIGH). Lambs were allocated into individual pens and fed ad libitum with feed delivered twice daily. Feed intake was recorded daily, and body weight (BW) was assessed at the beginning and the end of the 29-d period. Blood was sampled on day 21, prior to feeding and 6 h post-feeding to evaluate changes in β-hydroxybutyrate, glucose, and insulin concentrations. Total fecal collection was conducted during days 25 to 28 to assess apparent total tract digestibility. On day 29, lambs were slaughtered, and the entire GIT was separated by region to enable sampling of tissue and digesta. Data were analyzed to assess linear, quadratic, and cubic effects of HFCG dose. Final BW, average daily gain, and dry matter intake decreased linearly (P ≤ 0.02) with increasing HFCG. Increasing inclusion of HFCG linearly decreased (P = 0.01) the thickness of the stratum corneum in ruminal papillae but did not affect other strata (P ≥ 0.34). Omasal digesta weight linearly decreased (P = 0.01) as the concentration of HFCG increased and abomasal digesta weight was cubically affected (P = 0.03) the increasing dose of HFCG. Short-chain fatty acid concentration in the cecum was cubically affected (P < 0.01) with increasing dose of HFCG where low dose had the greatest concentration. Moreover, increasing the dietary supply of HFCG linearly increased the proportion of acetate (P = 0.04) in the cecum and linearly decreased the proportion of propionate in the digesta of both the cecum (P < 0.01) and colon (P = 0.01). Colon crypt depth was quadratically (P = 0.03) affected with the increasing dose of HFCG, where lambs fed MED had greatest crypt depth. We conclude that feeding HFCG to growing lambs did not increase butyrate concentration in the large intestine and consequently does not increase the absorptive surface area of the whole tract, the size of the GIT, or the functionality of the intestine.

1325-P: Modulation of Overnight Free Fatty Acid and Glucose Concentrations and Their Effect on Postprandial Islet Function and Glucose Metabolism

Individuals with prediabetes can be classified by fasting and glucose tolerance status. Previously we observed that elevated fasting Free Fatty Acids (FFA) are associated with Impaired Glucose Tolerance (IGT) and decreased β-cell function (quantified as Disposition Index (DI)) . Impaired Fasting glucose (IFG) is associated with further decreases in DI. To examine how changes in fasting FFA and glucose alter islet function, we studied subjects with Normal Fasting Glucose (NFG) and Normal Glucose Tolerance (NGT) on 2 occasions. On one occasion, Intralipid and glucose were infused overnight to mimic conditions present in IFG / IGT. In addition, we studied 7 subjects with IFG / IGT on 2 occasions. On one occasion insulin was infused to lower overnight FFA and glucose concentrations to those observed in people with NFG / NGT. The 2 groups were matched for Body Mass Index (BMI: 32±3 vs. 31±2 kg/m2, NFG / NGT vs. IFG / IGT respectively, p = 0.87) . The following morning, a labeled mixed meal was used to measure postprandial glucose metabolism and β-cell function. Elevation of overnight fasting FFA and glucose in NFG / NGT did not alter peak or integrated glucose concentrations (2.0 ± 0.1 vs. 2.0 ± 0.1 Mol per 5 hrs, Saline vs. Intralipid / glucose, p = 0.55) . In people with IFG / IGT, insulin also did not alter peak and integrated glucose concentrations (2.5 ± 0.1 vs. 2.5 ± 0.2 Mol per 5 hrs, Saline vs. Insulin, p = 0.39) . Changing overnight concentrations of glucose and FFA did not alter postprandial concentrations of insulin and C-peptide in either group. While fasting Endogenous Glucose Production (EGP) differed between groups (14 ± 1 vs. 18 ± 1 μmol/kg/min, NFG / NGT vs. IFG / IGT, p &amp;lt; 0.01) , intervention did not change fasting and nadir EGP. Peak and integrated meal appearance and DI were also unchanged by intervention in either group. We conclude that acute, overnight changes in FFA and glucose concentrations do not alter islet function or glucose metabolism in prediabetes. Disclosure A.A.Welch: None. D.Schembri wismayer: None. A.M.Egan: None. R.A.Farahani: None. M.C.Laurenti: None. C.Cobelli: None. C.Dalla man: Research Support; Becton, Dickinson and Company, Sanofi-Aventis Deutschland GmbH. A.Vella: Advisory Panel; Crinetics Pharmaceuticals, Inc., Rezolute, Inc., vTv Therapeutics, Zealand Pharma A/S, Other Relationship; Novo Nordisk. Funding NIH DK 078646

Pharmacodynamics, pharmacokinetics, safety, and tolerability of a ready-to-use, room temperature, liquid stable glucagon administered via an autoinjector pen to youth with type 1 diabetes.

Prompt and reliable management of hypoglycemia in youth with diabetes is important to prevent serious medical complications. To determine efficacy, pharmacodynamics (PD), pharmacokinetics (PK), safety, and tolerability of a ready-to-use, liquid stable glucagon formulation administered subcutaneously via an autoinjector pen to youth with type 1 diabetes (T1D). After plasma glucose concentration was < 80 mg/dL (< 4.4 mmol/L) after insulin, participants aged 2 to < 12 years with T1D were administered 0.5mg of glucagon; participants aged 12 to < 18 years instead received 1mg of glucagon. Then, adolescents were challenged with 0.5mg after a 7- to 28-day washout period. Primary endpoint was mean plasma glucose concentration at 30min after glucagon. Plasma glucose concentrations significantly (p< 0.001) increased from baseline to 30min after glucagon, with mean change in plasma glucose concentration between baseline and 30min for each age cohort as follows: 2 to < 6 years (n= 7; 81.4mg/dL [4.5 mmol/L]); 6 to < 12 years (13; 84.2mg/dL [4.7 mmol/L]); 12 to < 18 years (11; dose, 1mg; 54.0mg/dL [3.0 mmol/L]); and 12 to < 18 years (11; 0.5mg; 52.4mg/dL [2.9 mmol/L]). Among age cohorts, no clinically relevant differences were observed for PD and PK parameters. Common adverse events were nausea, vomiting, and hypoglycemia. Age-appropriate dosing of this glucagon formulation was effective at 30min in reversing plasma glucose concentrations from < 80 mg/dL in youth with T1D.

Biofumigation effects of brassicaceous cover crops on soil health in cucurbit agroecosystems in Hawaii, USA

Brassicaceous cover crops, such as brown mustard (Brassica juncea) and oil radish (Raphanus sativus), are commonly used for biofumigation, a process that utilizes isothiocyanates (ITCs) generated from the hydrolysis of glucosinolates in Brassica plants to suppress soil-borne pathogens, including plant-parasitic nematodes. Given the biocidal nature of ITCs, limited information is available on the non-target effects of biofumigation on free-living nematodes, which are reliable soil health indicators. The objectives of this study were to determine if biofumigation methods effective against plant-parasitic nematodes would have non-target effects on free-living nematodes, and to examine the relationships between biofumigation indicators and nematode communities. Three field trials were conducted to examine whether different biofumigation methods would affect free-living nematodes. Tissue maceration of biofumigant crops, soil tillage, and black plastic mulching were adopted singly or in combination to generate different regimes of biofumigation efficacy. Termination of biofumigant crops by tissue maceration and soil tillage followed by black plastic mulching for one week was most effective in suppressing plant-parasitic nematodes and enhancing bacterial decomposition. However, these effects did not last through the subsequent zucchini (Cucurbita pepo) crop cycle. When comparing changes in soil glucose and sulfate concentrations as indicators of biofumigation efficacy, we found that soil sulfate was a better indicator of biofumigation efficacy than soil glucose, owing to the more stable state of sulfate in soil. Canonical correspondence analysis between soil sulfate as a biofumigation indicator and nematode soil health indicators revealed strong positive correlations of sulfate level with the abundances of bacterivorous and carnivorous nematodes, enrichment index, brown mustard biomass, and soil temperature. However, biofumigation did not affect the nematode community structure. This study demonstrated that biofumigation can suppress plant-parasitic nematodes without compromising soil health.

Exercise Training and Chemogenetic Activation of the Dorsal Motor Nucleus of the Vagus Rescue the Changes in the Hepatic Vein Glucose Concentration by Central Action of Insulin in SHR

The Dorsal Motor Nucleus of the Vagus (DMNV) is the main parasympathetic output from CNS as part of the brain‐liver axis that participates on glucose homeostasis. Previously, we have shown that icv injection of insulin elicited a decrease the hepatic vein glucose concentration (HVGC) of Wistar, but not in SHR. Here we aimed to investigate whether the deficiency of central action of insulin to control the HVGC of SHR is due to a dysfunction in the cholinergic neurotransmission in the DMNV and which putative neurotransmitter could play a role in this circuitry. To this, we used in vivo and in vitro studies using chemogenetic tools, and the whole‐cell patch‐clamp recordings. Ethical approval: CEUA/ICB‐USP #8336131119). IN VIVO STUDIES: Male SHR (12 weeks old) received an injection of DREADD (LVV‐Gq‐hM3q‐PRSx8‐eGFP) to selectively activate de DMNV neurons with clozapine‐N‐oxide (CNO). After 10 days of CNO treatment, the animals received icv injection of insulin and the HVGC was monitored in freely moving rats. IN VITRO STUDIES: to identify liver‐projecting DMVN neurons, age‐matched (12 weeks old) of Wistar and sedentary and exercised trained SHR (SHRt) received, 5 days prior to the experiments, injections of Fluorogold (FG) on the liver parenchyma. At the day of the electrophysiological studies, the FG‐labeled DMVN neurons was visualized and recorded in whole‐cell patch‐clamp mode, before and after application of oxytocin (OT) in the bath. The results of in vivo studies have shown that in the DREADD group the icv insulin was able to reduce the HVGC when compared to the control group (Control: 113,6±14,9 mg/dL n=5; vs DREADD: 74,2±6,16mg/dL; p≤0,05). As for the in vitro studies, the application of OT in liver projecting‐DMNV depolarized the resting membrane potential (Basal: −59.4± 0.7 mV vs OT: −56.2 ± 1.2 mV, n = 10; t = 2.403, df = 9; P = 0.0397) and increased the firing frequency (baseline: 1.9±0.8 vs OT: 3.0 ± 0.9 Hz, n=10; P = 0.002) in Wistar, but not in sedentary SHR. Interestingly, in SHR trained for 4 weeks, the OT caused depolarization of resting membrane potential (baseline: −61.3 ± 1.3 vs OT: −59.6 ± 1.5 mV, n=18; P=0.0177) and an increase in the firing frequency (baseline: 3.9±0.7 vs OT: 4.7±0.6 Hz, n=18, P=0.0012). As conclusion, the selective activation of parasympathetic preganglionic neurons of the DMNV rescues the changes in the HVGC elicited by central action of insulin, which used to be defective in SHR, indicating that the circuitry involving DMNV‐liver pathway is somehow dysfunctional, which could be due to the autonomic unbalance observed in this strain. Moreover, OT elicits similar changes in the electrophysiological properties of liver‐projecting DMNV neurons of Wistar and exercise‐trained but not sedentary SHR. These results indicate that exercise training can restore the sensitivity of liver‐projecting DMNV neurones of exercise trained SHR to OT.

A 24‐Hour Fast Increases Liver Cytotoxic T Cell Populations in Genetically Obese Mice: A Preliminary Study

BACKGROUNDRecent data suggests that regulated fasting protocols can improve metabolic parameters associated with obesity. However, questions remain regarding the appropriate fasting duration needed to attenuate obesity‐associated complications such as glucose intolerance, arterial stiffness, and immune cell dysfunction. Therefore, the primary purpose of this study was to examine if an acute 24‐hour fast improves detrimental consequences of obesity and alters tissue‐specific immune cell counts in obese mice.METHODSTen 12‐week‐old male and female genetically obese mice (Ob; n=20) and wild‐type littermates (WT; n=20) were fed a standard diet and randomized to either ad libitum feeding or a 24‐hour fast (WT‐CON, WT‐Fast, Ob‐CON, Ob‐Fast). Mouse weight was measured before and after feeding protocols. Following feeding protocols, arterial stiffness was assessed via arterial pulse wave velocity (aPWV); liver and mesenteric adipose tissue (MAT) immune cell populations were assessed via spectral flow cytometry and normalized by tissue weight. For statistical analyses, sex‐adjusted regression models were fit to account for the confounding effects of sex.RESULTSThere was not a significant interaction between genotype and intervention on changes in body weight, plasma glucose concentrations, or aPWV (p=0.16; p=0.33; p=0.37, respectively). After adjusting for genotype, acute fasting did not significantly alter changes in plasma glucose concentrations or aPWV (p=0.95; p=0.22). However, after adjusting for genotype, acute fasting promoted significant weight loss (CON 0.4g ± 0.56; Fast ‐2.6g ± 0.72; p&lt;0.01). Compared to Ob‐CON, Ob‐Fast mice had significant increases in liver total immune and cytotoxic T cells (p&lt;0.01) yet no significant changes in either liver regulatory T or helper T cells nor in MAT total immune, cytotoxic T, helper T, and regulatory T cell populations. WT‐Fast mice had significant reductions in liver total immune, cytotoxic T, helper T, and regulatory T cell populations while these same cell populations were increased in MAT when compared to WT‐CON mice.CONCLUSIONSAn acute 24 hr. fast in mice was insufficient to significantly modulate glucose intolerance and aPWV in Ob mice compared to WT. However, fasting differentially affected liver and MAT T cell populations in mice. These results suggest acute fasting could be a robust mediator of T cell populations with a particular emphasis on expanding liver cytotoxic T cell communities in obese mice.

Real-Time Detection of Body Nutrition in Sports Training Based on Cloud Computing and Somatosensory Network.

With the progress of society and the improvement of living standards, sports training has gradually become an area of increasing concern for society and individuals. To more comprehensively grasp the physical function, body shape, and physical fitness of athletes, many researchers have conducted extensive research on the real-time detection of human body nutrition. This study is mainly supported by cloud computing and somatosensory network technology, and the real-time detection of human body composition in sports training is the main research object. In the experiment, two methods of human body composition detection were tested: the BIA method and the body composition analysis method based on the electrochemical sensor of body sweat. It designed a human nutrient composition detection system based on the BIA method. The error rate of the system is relatively small, which is basically maintained at about 2%. It uses a body surface sweat electrochemical sensor to detect changes in glucose concentration during human exercise. After exercising for a period of time, the test subject's sweat glucose concentration remained around 0.5 mM.

Bout duration in high-intensity interval exercise modifies hematologic, metabolic and antioxidant responses

Background/ObjectivesThis study compared hematologic, metabolic and antioxidant responses between three high-intensity interval exercise (HIIE) trials of different bout duration and a continuous exercise trial (CON), all with equal average intensity, total work, and duration. MethodsEleven healthy young males performed four trials involving 20 min of cycling, either continuously (49% of power at VO2max, PPO), or intermittently with 48 10-s bouts (HIIE10), 16 30-s bouts (HIIE30) or 8 60-s bouts (HIIE60) at 100% PPO, with a 1:1.5 work-to-recovery ratio at 15% PPO. Venous blood was obtained before, immediately after, and 1 h post-exercise to evaluate hematologic, metabolic and antioxidant responses. Blood lactate concentration was measured in capillary blood during exercise, while urine lactate was measured before and 1 h post-exercise. ResultsPost-exercise leukocyte count (mean ± SD; 9.7 ± 2.8 k μL−1), uric acid concentration (0.35 ± 0.10 mmol L−1), glucose concentration (6.56 ± 1.44 mmol L−1), and plasma volume change (−13.5 ± 4.4%) were greater in HIIE60 compared to all other trials (p < 0.05). One-hour post-exercise, lymphocytes decreased below pre-exercise values in all HIIE trials, and uric acid increased in the HIIE60 trial (p < 0.05). Urine lactate concentration 1 h post-exercise increased compared to pre-exercise only in HIIE60 (19-fold, p < 0.001), and this was related with the higher blood lactate concentration during exercise in that trial. ConclusionsThese findings highlight the importance of bout duration, given that shorter bouts of HIIE (30 s or 10 s) induce lower blood cell perturbations, metabolic stress, and antioxidant responses compared to the commonly used 1-min bouts, despite equal total work, duration, and work-to-recovery ratio.

Syngeneically transplanted insulin producing cells differentiated from adipose derived stem cells undergo delayed damage by autoimmune responses in NOD mice

Insulin-producing cells (IPCs) generated by our established protocol have reached the non-clinical ‘proof of concept’ stage. Our strategy for their clinical application is the autotransplantation of IPCs into patients with type 1 diabetes mellitus (T1DM). In this context, the autoimmunity that characterized T1DM is important, rather than allorejection. We aimed to determine how these IPCs respond to T1DM autoimmunity. IPCs were generated from the subcutaneous fat tissue of non-obese diabetic (NOD) mice using our protocol. IPCs derived from NOD mice were transplanted under the kidney capsules of NOD mice at the onset of diabetes and the subsequent changes in blood glucose concentration were characterized. Blood glucose decreased within 30 days of transplantation, but increased again after 40–60 days in three of four recipient NOD mice. In tissue samples, the numbers of CD4+ and CD8+ T cells were significantly higher 60 days after transplantation than 30 days after transplantation. In conclusion, IPCs significantly ameliorate the diabetes of mice in the short term, but are damaged by autoimmunity in the longer term, as evidenced by local T cells accumulation. This study provides new insights into potential stem cell therapies for T1DM.

Quantification of tear glucose levels and their correlation with blood glucose levels in dogs.

BackgroundNo previous studies have quantified tear glucose (TG) levels in dogs or compared changes in TG and blood glucose (BG) concentrations.ObjectiveTo quantify TG concentration and evaluate its correlation with BG level in dogs.MethodsTwenty repetitive tests were performed in alternate eyes of four dogs, with a minimum washout period of 1 week. Tears and blood were collected at 30‐min intervals with successive glucose injections (1 g/kg) every 30 min. Cross‐correlations of BG and TG levels were assessed. The delay and association between TG and corresponding BG levels were analysed for each dog; samples were collected at 5‐min intervals. The tears were collected using microcapillary tubes. Collected tears and blood were analysed for glucose concentration using a colorimetric assay and commercially available glucometer, respectively.ResultsThe average baseline BG and TG levels were 4.76 ± 0.58 and 0.39 ± 0.04 mmol/L, respectively. Even with highly fluctuating BG levels, a significant cross‐correlation coefficient (r = 0.86, p < 0.05) was observed between changes of BG and TG levels. The delay time between BG and TG levels was 10 min. On average, BG levels were 16.34 times higher than TG levels. There was strong correlation between BG and TG levels (r s = 0.80, p < 0.01). Significant differences in TG concentrations between normoglycaemia, mild hyperglycaemia, and severe hyperglycaemia were found (p < 0.05).ConclusionsCanine TG concentrations have not been quantified previously. Our findings suggest preliminary data for future research on TG levels in dogs and show TG measurement could be used to screen for diabetes mellitus in dogs.

The Role of Insulin-like Peptide in Maintaining Hemolymph Glucose Homeostasis in the Pacific White Shrimp Litopenaeus vannamei.

Insulin-like peptide (ILP) has been identified in various crustaceans, but whether it has a similar function in regulating hemolymph glucose as vertebrate insulin is unclear. We analyzed the components of hemolymph sugar in the Pacific white shrimp, Litopenaeus vannamei, and investigated the changes of hemolymph glucose concentration and the expressions of ILP and glucose metabolism genes under different treatments. We found glucose was a major component of hemolymph sugar in shrimp. Starvation caused hemolymph glucose to rise first and then decline, and the raised hemolymph glucose after exogenous glucose injection returned to basal levels within a short time, indicating that shrimp have a regulatory mechanism to maintain hemolymph glucose homeostasis. In addition, injections of bovine insulin and recombinant LvILP protein both resulted in a fast decline in hemolymph glucose. Notably, RNA interference of LvILP did not significantly affect hemolymph glucose levels, but it inhibited exogenous glucose clearance. Based on the detection of glucose metabolism genes, we found LvILP might maintain hemolymph glucose stability by regulating the expression of these genes. These results suggest that ILP has a conserved function in shrimp similar to insulin in vertebrates and plays an important role in maintaining hemolymph glucose homeostasis.

Controlled Release of Insulin Based on Temperature and Glucose Dual Responsive Biomicrocapsules.

The treatment of diabetes lies in developing novel functional carriers, which are expected to have the unique capability of monitoring blood glucose levels continuously and dispensing insulin correctly and timely. Hence, this study is proposing to create a smart self-regulated insulin delivery system according to changes in glucose concentration. Temperature and glucose dual responsive copolymer microcapsules bearing N-isopropylacrylamide and 3-acrylamidophenylboronic acid as main components were developed by bottom-spray coating technology and template method. The insulinoma β-TC6 cells were trapped in the copolymer microcapsules by use of temperature sensitivity, and then growth, proliferation, and glucose-responsive insulin secretion of microencapsulated cells were successively monitored. The copolymer microcapsules showed favorable structural stability and good biocompatibility against β-TC6 cells. Compared with free cells, the biomicrocapsules presented a more effective and safer glucose-dependent insulin release behavior. The bioactivity of secreted and released insulin did not differ between free and encapsulated β-TC6 cells. The results demonstrated that the copolymer microcapsules had a positive effect on real-time sensing of glucose and precise controlled release of insulin. The intelligent drug delivery system is supposed to mimic insulin secretion in a physiological manner, and further provide new perspectives and technical support for the development of artificial pancreas.

Comparison of hydration efficacy of carbohydrate-electrolytes beverages consisting of isomaltulose and sucrose in healthy young adults: A randomized crossover trial

Isomaltulose is a low glycemic and insulinaemic carbohydrate now used as an alternative sweetener in beverages. However, it remains unclear if hydration status may be impacted differently with the consumption of beverages containing isomaltulose as compared to sucrose, a common beverage sweetener. Thirteen young adults (7 women) consumed 1 L of a carbohydrate beverage (with low electrolyte content) containing either 6.5%-sucrose, 6.5%-isomaltulose, or water within a 15 min period. For each beverage, beverage hydration index (BHI, a composite measure of fluid balance after consuming a test beverage relative to water) was calculated from urine volume produced over a 3 h period following ingestion of the carbohydrate beverages relative to water. The change in plasma volume (ΔPV), blood glucose, and lactate concentrations were assessed every 30 min post-beverage consumption. Isomaltulose ingestion attenuated urine production as compared to water and sucrose (P ≤ 0.005) over the 3 h post-ingestion period. However, no differences were observed between sucrose and water (P = 0.055). BHI was 1.53 ± 0.44 for isomaltulose (P ≤ 0.022 vs. sucrose and water) and 1.20±0.29 for sucrose (P = 0.210 vs. water). A transient reduction in ΔPV was observed following the ingestion of the isomaltulose beverage (at 30 min, P = 0.007 vs. sucrose). Thereafter, no differences in ΔPV between beverages were measured. Increases in blood glucose and lactate, indices of absorption and utility of glucose, were delayed in the isomaltulose as compared to sucrose beverage. In summary, we demonstrated a greater BHI with a carbohydrate-electrolyte beverage containing isomaltulose as compared to sucrose. This may in part be attributed to a delayed absorption of isomaltulose reducing diuresis.

Homeostatic Regulation of Glucose Metabolism by the Central Nervous System

Evidence for involvement of the central nervous system (CNS) in the regulation of glucose metabolism dates back to the 19th century, although the majority of the research on glucose metabolism has focused on the peripheral metabolic organs. Due to recent advances in neuroscience, it has now become clear that the CNS is indeed vital for maintaining glucose homeostasis. To achieve normoglycemia, specific populations of neurons and glia in the hypothalamus sense changes in the blood concentrations of glucose and of glucoregulatory hormones such as insulin, leptin, glucagon-like peptide 1, and glucagon. This information is integrated and transmitted to other areas of the brain where it eventually modulates various processes in glucose metabolism (i.e., hepatic glucose production, glucose uptake in the brown adipose tissue and skeletal muscle, pancreatic insulin and glucagon secretion, renal glucose reabsorption, etc.). Errors in these processes lead to hyper- or hypoglycemia. We here review the current understanding of the brain regulation of glucose metabolism.

Pt Concave Nanocubes with High-Index Facets as Electrocatalysts for Glucose Oxidation

The modification of the surface atomic arrangements, especially the exposure of high-index facets, has been considered as a valid strategy to strengthen the catalytic performance of Pt-based nanocrystals. In this article, Pt concave nanocubes (Pt CNCs) with exposed high-index (510) facets are facilely synthesized through a hydrothermal method. Polyvinylpyrrolidone (PVP) and glycine are required for shape control. The mechanism of electrocatalytic oxidation toward glucose by Pt CNCs is fully discussed. The exposed high-index facets consist of abundant low-coordinated atoms (containing edges, steps, and kinks), can supply sufficient active sites for the adsorption of reactants and intermediate species, and thus enhance the catalytic activity in glucose oxidation. By using saturated calomel electrode as the reference electrode, a 1 cm2 platinum sheet as the counter electrode, and glassy carbon electrode (GCE) as the working electrode, the Pt CNC catalyst-decorated GCE exhibits higher peak current densities of 0.25, 0.15, and 0.56 mA cm–2 than those of the commercial Pt/C (10 wt. %)-modified GCE. The Pt CNC catalyst shows a rapid response toward the changes in glucose concentration. The electrocatalytic oxidation of glucose exhibits better performance in neutral and alkaline conditions than in an acidic electrolyte. Above all, the prepared Pt CNC catalysts with high-index (510) facets are expected for their wide use as abiotic catalysts in the electrocatalytic oxidation of glucose.

Quantitative Proteome Analysis in Response to Glucose Concentration in C2C12 Myotubes

Glucose is important for the maintenance of muscle function; however, it is still unclear how changes in glucose concentration affect muscle. Here, we analyzed the effect of glucose concentration on protein expression under different glucose concentration media in C2C12 myotubes. First, we performed proteome analysis in C2C12 myotubes cultured in Low (1.0 g/L), Medium (2.0 g/L), and High (4.5 g/L) glucose media. Proteome analysis revealed 113 proteins were significantly changed in group cultured in Low or Medium glucose media compared to group cultured in High glucose media. Furthermore, glycolysis, oxidative phosphorylation, and fatty acid metabolism were increased in the Medium and Low groups. Among these pathways, HK2, PFKP, NDUFA11, and FABP3 were especially upregulated proteins in Low and Medium groups. In this context, ATP production in C2C12 myotubes cultured in Low and Medium glucose media was increased. There was no significant change in myotubes morphology and myogenic differentiation factors in all groups. Finally, we examined the effect on glucose concentration in culture media on myosin isoforms expression by qRT-PCR. As a result, Myh2 and Myh4 were significantly increased in Low and Medium conditions. Altogether, Low and Medium glucose conditions induced Myh expression probably via enhancement glucose utilization.

Where can you wear your Libre? Using the FreeStyle Libre continuous glucose monitor on alternative sites.

To investigate the accuracy and acceptability of the FreeStyle Libre Flash continuous glucose monitoring system (FSL-CGM) at alternative sites during free living and under experimental conditions. Participants with type 1 diabetes were provided with three FSL-CGM sensors applied to the upper arm, the lower back, and the anterior chest. On day 2 or 3, FSL-CGM sensor glucose was compared with venous glucose following a standard meal, during and after an exercise test, and after skin cooling. Participants completed 14-day use of the sensors with concomitant sensor scanning at all sites and capillary glucose tests. The primary outcome was accuracy between sensor sites of 14-day mean glucose. Clarke's error grids, precision absolute relative deviation, and mean absolute relative deviation were calculated. In the 20 participants, compared with the arm sensor, the accuracy of the back sensor and the chest sensor was 97.9% and 98%, respectively. Under experimental conditions, the arm sensor was more accurate than that of the back and chest. All the sensors recorded higher glucose concentration than venous samples during exercise. The arm and chest sites were most preferred, with the greatest sensor failures from the back. The FSL-CGM is clinically accurate when the sensors are applied to alternate chest or back sites. Greater variability occurs during rapid changes in glucose concentration with all sensor sites compared with venous glucose. Understanding these variabilities allows appropriate use of an economically viable continuous glucose monitor.

Establishment of a fiber optic sensor coupled to the plasmonic effect of silver nanoparticles in glucose concentration monitoring

Introduction: Diabetes is an extremely dangerous disease due to the disorder of glucose metabolism in the body leading to serious complications and the cause other dangerous diseases. Therefore, the continuous monitoring of glucose levels in the body is particularly important in the prevention and treatment of this disease. Optical fiber sensors that apply the LSPR effect of silver nanoparticles show great potential in the field of sensors that enable precise label-free monitoring of analyte concentrations with high sensitivity, which is receiving much attention. Methods: Based on the sensitivity of the LSPR effect on the surface of AgNPs to the dielectric properties of the medium, namely the refractive index of the analyte solution. Variation in the LSPR conditions of AgNPs leads to either donation or reduction in optical power. Based on that mechanism, the fiber was used as a waveguide and was immobilized on a self-assembled monolayer of AgNPs 1 core surrounded by a microfluidic channel that allows the analyte solution to pass through the sensing area through a biological pump. This process of changing the capacity allows the assessment of glucose concentration in solution to a very small degree of change. Results: AgNPs of about 90 nm in size were quickly and simply synthesized with high stability and uniformity by chemical reduction with an Ethylene glycol reducing agent as demonstrated by FESEM, and DLS results. The LSPR wavelength of AgNPs solution observed by UV-vis spectrum is 435 nm. At the same time, a fiber-optic sensor system that monitors glucose concentration changes has also been successfully established with a sensitivity of 0.025 RIU corresponding to a detection of limited (LOD) of up to 0.35 mM. Conclusions: The optical fiber optical sensor based on the LSPR phenomenon of AgNPs was initially established and showed high sensitivity in detecting and monitoring changes in glucose concentration without the use of complex markers or enzymes. The compact size of the fiber sensor opens up the potential for integration into handheld optical devices to help monitor health more proactively. Keywords: Silver nanoparticles, LSPR, Glucose sensor, optical sensor, detection of limited.