Application of transcutaneous diffuse reflectance spectroscopy in the measurement of blood glucose concentration

In this paper, the propagation characteristics of near-infrared (NIR) light in the palm tissue are analyzed, and the principle and feasibility of using transcutaneous diffuse reflectance spectroscopy for non-invasive blood glucose detection are presented. An optical probe suitable for measuring the diffuse reflectance spectrum of human palm and a non-invasive blood glucose detection system using NIR spectroscopy are designed. Based on this system, oral glucose tolerance tests are performed to measure the blood glucose concentrations of two young healthy volunteers. The partial least square calibration model is then constructed by all individual experimental data. The final result shows that correlation coefficients of the two experiments between the predicted blood glucose concentrations and the reference blood glucose concentrations are 0.9870 and 0.9854, respectively. The root mean square errors of prediction of full cross validation are 0.54 and 0.52 mmol/1, respectively.

Effects of High Concentration Glucose on the Expression of NF-κB,Bax and Cytochrome C and Apoptosis of Islet Cells in Mice

The roles of NF-kappaB （NF-κB） expression, Bax activity and cytochrome C （Cyt C） release, apoptosis of islet cells induced by high concentration glucose were explored in vitro. Pancreatic islet cells, which were isolated from Kunming mice, were cultured with different concentrations of glucose in DMEM, and divided into the following groups： G1, G2, G3, G4, G5, and G6 groups, corresponding to the glucose concentrations of 5.6, 7.8, 11.1, 16.7, 22.5, and 27.6 mmol/L, respectively. After culture for 120 h, insulin secretion was evaluated by radioimmunoassay, and the NF-rd3 expression was detected by immunocytochemistry. Bax activity and Cyt C release were measured by immunofluorescence, and apoptosis was examined by Hoechst33342 assay. The results showed that in GI, G2 and G3 groups, insulin secretion was enhanced with the increase of glucose concentration, and the NF-κB expression was also increased （P〈0.05）, but Bax activity, Cyt C release and apoptosis rate showed no significant difference among them. However, in G4, G5, and G6 groups, apoptosis rate of islet cells, NF-rd3 expression, Bax activity, and Cyt C release were all significantly increased, and insulin secretion was impaired as compared with G1, G2, and G3 groups （P〈0.05）. It was concluded that the exposure of islet cells to high glucose could induce islet cells apoptosis as well as impaired insulin secretion. The NF-κB signaling pathway and mitochondria pathway in islet cells might play some roles in the progressive loss of islet cells in diabetes. The inhibition of the NF-κB expression could be an effective strategy for protecting pancreatic islet cells.

Accuracy evaluation of Roche Accu-Chek Performa blood glucose meters at low glucose concentrations:A nine-year retrospective study

Objective:To evaluate the accuracy of Roche Accu-Chek Performa glucose meters at a low glucose concentration of<5.55 mmol/L(100 mg/dL)over a 9-year period.Methods:The accuracy of the Roche Accu-Chek Performa glucose meters at low glucose concentrations was evaluated using annual comparison data for 9 consecutive years from 2015 to 2023,according to the acceptability criteria specified in International Organization for Standardization(ISO)15197:2013.Blood samples with low glucose concentrations of<5.55 mmol/L were prepared by incubation and glycolysis.The glucose concentration was detected using Roche Accu-Chek Performa glucose meters and a biochemical analyzer in the central laboratory.Results:A total of 2978 pairs of comparison results from 211 glucose meters at a low glucose concentration of<5.55 mmol/L were retrospectively analyzed from 2015 to 2023.The clinical use duration spanned from 1 to 9 years and 40.76%(86 out of 211 glucose meters)had been used for more than 2 years.The correlation coefficient r between glucose meter measurements and laboratory reference values was 0.98(p<0.001).The mean according to Roche Accu-Chek Performa glucose meters was 0.05 mmol/L(0.9 mg/dL)higher than that of the biochemical analyzer(Z=-13.82,p<0.0001).The results showed that 100.00%(211 out of 211)of the Roche Accu-Chek Performa glucose meters met the acceptability criteria specified in ISO 15197:2013.At a low glucose concentration of<5.55 mmol/L,99.90%(2975 out of 2978)of the comparative data pairs in the error distribution fell within the range of±0.83 mmol/L(15 mg/dL).Parkes consensus error grid analysis showed that 100.00%(2978 out of 2978)of comparative data pairs fell within region A.Conclusions:This study demonstrated that Roche Accu-Chek Performa glucose meters successfully met the accuracy standards of ISO 15197:2013 for measuring blood glucose within the hypoglycemic range.Greater attention should be given to the performance of blood glucose monitoring systems in the low glycemic range,especially for patients with diabetes who are prone to hypoglycemia and require precise measurements.

Preoperative carbohydrate load to reduce perioperative glycemic variability and improve surgical outcomes:A scoping review

The detrimental effects of both diabetes mellitus(DM)and hyperglycemia in the perioperative period are well established and have driven extensive efforts to control blood glucose concentration(BGC)in a variety of clinical settings.It is now appreciated that acute BGC spikes,hypoglycemia,and high glycemic variability(GV)lead to more endothelial dysfunction and oxidative stress than uncomplicated,chronically elevated BGC.In the perioperative setting,fasting is the primary approach to reducing the risk for pulmonary aspiration;however,prolonged fasting drives the body into a catabolic state and therefore may increase GV.Elevated GV in the perioperative period is associated with an increased risk for postoperative complications,including morbidity and mortality.These challenges pose a conundrum for the management of patients typically instructed to fast for at least 8 h before surgery.Preliminary evidence suggests that the administration of an oral preoperative carbohydrate load(PCL)to stimulate endogenous insulin production and reduce GV in the perioperative period may attenuate BGC spikes and ultimately decrease postoperative morbidity,without significantly increasing the risk of pulmonary aspiration.The aim of this scoping review is to summarize the available evidence on the impact of PCL on perioperative GV and surgical outcomes,with an emphasis on evidence pertaining to patients with DM.The clinical relevance of GV will be summarized,the relationship between GV and postoperative course will be explored,and the impact of PCL on GV and surgical outcomes will be presented.A total of 13 articles,presented in three sections,were chosen for inclusion.This scoping review concludes that the benefits of a PCL outweigh the risks in most patients,even in those with well controlled type 2 DM.The administration of a PCL might effectively minimize metabolic derangements such as GV and ultimately result in reduced postoperative morbidity and mortality,but this remains to be proven.Future efforts to standardize the content and timing of a PCL are needed.Ultimately,a rigorous data-driven consensus opinion regarding PCL administration that identifies optimal carbohydrate content,volume,and timing of ingestion should be established.

Medical Nutritional Therapy for Pre-gestational and Gestational Diabetes Mellitus

Pregnancy causes a multitude of metabolic changes within a woman’s body in order to provide the proper nutrients to the developing fetus. In women with diabetes type 1, type 2, and GDM （gestational diabetes mellitus） these metabolic perturbations must be treated distinctly and aggressively to optimize fetal development and health. Pre-gestational diabetes （either type 1 or type 2） has the potential to subject the developing fetus to abnormal maternal glucose levels resulting in problems with organogenesis producing congenital abnormalities or spontaneous abortion. Furthermore, gestational diabetes mellitus presents after organogenesis in the second part of pregnancy, therefore the major risk for the fetus is macrosomia. Although the goal for dietary therapy for each of these disorders is the same which is euglycaemia, the means to achieve it are very different and somewhat controversial. In the case of gestational diabetes, the main stay of therapy is medical nutritional therapy whereas in insulin requiring diabetes, dietary therapy is compensated with pre-meal insulin injections. The metabolic changes in normal pregnancy will be presented followed by the general guidelines for pregnancy. Fetal complications associated with inadequate nutrition or metabolic perturbation will be briefly explored, followed by issues and treatment for gestational diabetes mellitus, with emphasis on specific dietary therapies for GDM.

Determination of a Numerical Analysis Algorithm for the Regulation of Blood Sugar in Diabetics

Acceptable glycemic control when examining the effects of meals was achieved when combining basal insulin therapy and high concentration insulin injection before a meal, when using a PID controller (Proportionality, Integrity and Derivative actions) alone, when using a PID controller with basal insulin therapy and when combining the three methods of insulin delivery. Naturally, a type 1 diabetic must inject himself with insulin in well-measured doses. Thus, the management and control of diabetes become a complex task when one must be considered the disturbance due to nutrition and sports activity. This concern has been at the center of much research through different approaches through mathematical methods and Artificial Intelligence methods. This article simulates a physiological model of glycemic control in type 1 diabetics by a PID regulatory mechanism, in the context of disturbances caused by the patient’s meals and athletic activity.

Catalytic synthesis of diethyl carbonate with supported Pd-Cu bimetallic nanoparticle catalysts:Cu(Ⅰ) as the active species

Cupric oxide （CuO） and copper-cuprous oxide （Cu-Cu2O） nanoparticles were prepared by a simple hydrothermal method for the synthesis of diethyi carbonate （DEC） from ethanol. During these syntheses, varying NaOH and glucose concentrations were applied to explore and pinpoint the active species. It was found that PdCl2/CuO and PdCI2/Cu-Cu2O both catalysts exhibited good thermal stability and morphology. The results of catalytic tests showed that the catalysts prepared with 5 mol/L NaOH show superior catalytic performances because of their lower extent of agglomeration. It is noteworthy that the PdC12/Cu-Cu2O catalysts were the most active, especially the PdCl2/Cu-Cu2O catalyst prepared with 10 mmol glucose and having a higher Cu2O concentration. In Pd（ll）-Cu（II） （PdCl2/CuO） catalysts, there is an induction period, during which Pd（II） is reduced to Pd（0）, that must occur prior to electron transfer between Pd and Cu, and this can slow the catalytic reaction. To further pinpoint the active species, PdCl2/Cu-Cu2O catalysts with different Cu2O contents were prepared by controlling the dosages of glucose. The maximum DEC yield obtained with these catalysts was 151.9 mg.g-1.h-1, corresponding to an ethanol conversion of 7.2% and 97.9% DEC selectivity on an ethanol basis. Therefore, it was concluded that Cu＋ was the active species in this catalytic system, possibly because a higher proportion of Cu＋ reduces the Pd2＋ concentration and limits the CO oxidation side reaction, thus increasing DEC selectivity. In addition, Cu＋ promotes electron transfer between Pd and Cu without an induction period, which could also promote the catalytic activity.