Whole Blood Glucose Concentrations Research Articles

Improvement of point of care testing device for accurate whole blood glucose measurement in early neonates.

It is important that blood glucose concentrations be accurately and conveniently measured in infants. However, especially in the early neonatal period, point-of-care testing devices used for adults may not accurately measure blood glucose concentrations in neonates. In Study 1, the accuracy of neonatal whole-blood glucose measurements was evaluated for the existing glucose analyser Glutest Mint® (hereinafter MINT1; Sanwa Kagaku Kenkyusho, Nagoya, Japan) by comparing the data with reference blood glucose concentrations. In Study 2, we used MINT2, which was modified based on the findings from Study 1, to measure whole-blood glucose concentrations in newborns, and the accuracy of the measurements was compared with that of MINT1. Blood glucose concentrations were measured in 100 infants each in Study 1 and 2. In Study 1, the whole-blood glucose concentrations measured using MINT1 were found to be significantly lower than the reference blood glucose concentrations in early neonates. The results of Study 1 suggested that characteristics of erythrocyte membranes in early neonates affected the measurements. Therefore, we conducted Study 2 using MINT2, which was modified to be less susceptible. MINT2 was found to accurately measure whole-blood glucose concentrations in the early neonatal period. The study showed that the point-of-care testing device could be improved to allow for accurate whole-blood glucose measurements in the early neonatal period.

The effect of methionine and folic acid administered in ovo on the blood biochemical parameters of chickens (Gallus gallus domesticus)

Methionine is one of the most frequently supplemented amino acids in raising of poultry. However, an overdose of methionine can cause hyperhomocysteinemia. Folic acid, taking part in the process of homocysteine remethylation, is a factor affecting the reduction of the concentration of this amino acid. The study was carried out in 2 stages. The experiment of step I was to investigate the effect of methionine and/or folic acid administration in ovo in the early stage of embryogenesis (E4), and the experiment of the second stage - in the late stage of embryogenesis (E17) on the following biochemical parameters of chicken blood: glucose concentration in whole blood and concentration of homocysteine and uric acid in plasma of domestic chickens (Gallus gallus domesticus). Our results confirm that methionine supplementation may increase the concentration of uric acid and homocysteine. Moreover, we demonstrated that folic acid administered during embryogenesis decreased homocysteine concentration, also in groups simultaneously supplemented with methionine, especially in the initial stage of postnatal life of the bird.

Closed Bipolar Electrode-Enabled Electrochromic Sensing of Multiple Metabolites in Whole Blood.

We report a closed bipolar electrode (CBE)-based sensing platform for the detection of diagnostic metabolites in undiluted whole human blood. The sensor is enabled by electrode chemistry based on: (1) a mixed layer of blood-compatible adsorption-resistant phosphorylcholine (PPC) and phenylbutyric acid (PBA), (2) ferrocene (Fc) redox mediators, and (3) immobilized redox-active enzymes. This scheme is designed to overcome nonspecific protein adsorption and amplify sensing currents in whole human fluids. The scheme also incorporates a diffusing mediator to increase electronic communication between the immobilized redox enzyme and the working electrode. The use of both bound and freely diffusing mediators is synergistic in producing the electrochemical response. The sensor is realized by linking the analyte cell, containing the specific electrode surface architecture, through a CBE to a reporter cell containing the electrochromic reporter, methyl viologen (MV). The colorless-to-purple color change accompanying the 1e- reduction of MV2+ is captured using a smartphone camera. Subsequent red-green-blue analysis is performed on the acquired images to determine cholesterol, glucose, and lactate concentrations in whole blood. The CBE blood metabolite sensor produces a linear color change at clinically relevant concentration ranges for all metabolites with good reproducibility (∼5% or better) and with limits of detection of 79 μM for cholesterol, 59 μM for glucose, and 86 μM for lactate. Finally, metabolite concentration measurements from the CBE blood metabolite sensor are compared with results from commercially available FDA-approved blood cholesterol, glucose, and lactate meters, with an average difference of ∼3.5% across all three metabolites in the ranges studied.

Characterization of metabolic profile, health, milk production, and reproductive outcomes of dairy cows diagnosed with concurrent hyperketonemia and hypoglycemia.

The objective of this prospective cohort study was to characterize the metabolic profile, health, milk production, and reproductive outcomes of cows diagnosed with hyperketonemia (HK; β-hydroxybutyrate ≥1.2 mmol/L), hypoglycemia (HG; glucose ≤2.2 mmol/L), or concurrent HK and HG (HKHG). Glucose and β-hydroxybutyrate concentrations in whole blood were assessed using a handheld device (Precision Xtra, Abbott Laboratories) in lactating dairy cows (n = 2,418) between 3 and 9 d postpartum. Cows were categorized into 4 groups: no HK or HG (healthy; Norm = 1,821), HK only (HK = 232), HG only (HG = 161), and concurrent HK and HG (HKHG = 204). Subsequent milk production, along with health and reproductive outcomes, as recorded by farm personnel, were analyzed according to metabolic category. Serum collected on the day of cow-side diagnosis of hyperketonemia and hypoglycemia was evaluated for total calcium (tCa), magnesium (Mg), nonesterified fatty acids (NEFA), triglycerides (TG), and urea using an automated chemistry analyzer (Randox Daytona; Randox Laboratories Ltd.). Statistical analysis was carried out using SAS version 9.4 (SAS Institute Inc.). Hyperketonemia in multiparous cows was associated with greater incidence of metabolic abnormalities (hypomagnesemia, hypocalcemia, and elevated NEFA and urea). Hyperketonemia in primiparous and multiparous cows led to increased adverse health events (culling rate, retained fetal membranes, puerperal metritis, clinical ketosis, left displaced abomasum) relative to Norm cows. Multiparous cows with HKHG had fewer metabolic disturbances (hypomagnesemia, hypocalcemia, elevated NEFA) than HK cows. Cows with HKHG had an increased incidence of clinical ketosis and left displaced abomasum relative to Norm cows. Cows with HG had similar metabolic profiles to Norm cows and had lower incidence of retained fetal membranes and puerperal metritis than cows with HK. Multiparous cows with HG produced more milk than Norm cows from wk 10 to 20, whereas multiparous cows with HK produced less milk than Norm cows. For primiparous cows, HK did not have a negative effect on milk production compared with Norm cows.

HYPERGLYCEMIAAS AN INDEPENDENT RISK FACTOR FOR RETINOPATHY OF PREMATURITY (ROP): A COHORT STUDY

OBJECTIVE: Retinopathy of prematurity (ROP) is a severe morbidity that can lead to blindness in premature babies. Neonatal hyperglycemia has been related to the growth of ROP in a variety of studies. However, there aren't many observational trials to show whether hyperglycemia is linked to ROP in the absence of other comorbidities. The aim of this research was to see if hyperglycemia in premature babies is linked to ROP in a different way. STUDY DESIGN: Premature infants (<1500 g or⩽ 32 weeks gestational age) were enrolled in a prospective longitudinal cohort study. All demographic, clinical and laboratory data were collected. Bedside whole-blood glucose concentration was measured every 8 hours daily for rst 7 , days of live. For any glucose reading <50 or>150 mg dl 1 serum sample was sent to the laboratory for conrmation. Hyperglycemia was dened as any blood glucose level⩾ 150 mg dl − 1. ROP patients were compared with non-ROP patients in a bivariate analysis. Variables signicantly associated with ROP were studied in a logistic regression model. RESULT:Atotal of 100 patients were enrolled with gestational age <32weeks and birth weight <1500g. Forty-eight patients (48%) were identied with hyperglycemia. On eye examination, 30 cases (30%) had ROP (19 with stage 1, 10 with stage 2 and 1 with stage 3). There were more cases of ROPin the hyperglycemia group compared with the euglycemia group (45.83% vs 15.38%, P = 0.007). Patients who developed ROP had signicantly higher maximum and average glucose concentrations when compared with non-ROP patients. Multiple factors have been associated with ROP on bivariate analysis, including gestational age, exposure to oxygen, respiratory support and poor weight gain. However, in a logistic regression model including all signicant variables, average blood glucose in the rst week of life was the factor independently associated with ROPwith an odds ratio of: 1.77 (95% condence interval: 1.08 to 2.86), P= 0.024 CONCLUSION: In a prospective cohort study of premature infants, elevated average blood glucose concentrations in the rst week of life is an independent risk factor associated with the development of ROP.

Validating the Use of a Quick-Read Glucometer to Assess the Glycemic Response to Short-Term Capture Stress in Two Species of Snake, Nerodia sipedon and Sistrurus miliarius

The vertebrate stress response involves the release of adrenal hormones which make stored energy available to respond to stressors. The ability to effectively mobilize and distribute glucose is an important component of successful stress coping mechanisms. While many studies of reptiles have examined the hormonal response to stress under diverse contexts, comparatively few studies have focused on the glycemic response. Here we analyze the glycemic response to short-term capture stress in two species of snake, the Northern Water Snake (Nerodia sipedon) and the Pygmy Rattlesnake (Sistrurus miliarius), across reproductive contexts using a FreeStyle Lite (FSL) glucometer. The FSL is a point-of-care glucometer that provides a fast, inexpensive, and efficient method to monitor glucose concentrations in human whole blood. However, despite increasing use in reptiles, no studies have thoroughly validated their use in snakes or other squamates. We used a traditional colorimetric glucose assay to validate results using the FSL on both fresh whole blood and stored plasma. Hyperglycemia was induced by short-term capture stress in both species. The hyperglycemic response did not vary by sex, reproductive condition, or energetic status (body condition index, BCI). However, baseline and stress-induced glucose was higher in male compared to non-reproductive female N. sipedon. In S. miliarius, the magnitude of the glycemic response was positively correlated with cloacal body temperature. Baseline glucose was below the limit of detection in many individuals of both species, which may limit the utility of the FSL and other handheld glucometers in studies that seek to describe baseline values. Glucose estimates were strongly correlated when comparing all methods, indicating that the FreeStyle Lite is a potentially valuable tool to effectively compare the glycemic response to experimental treatment or to track changes in the glycemic response of snakes over time. However, significant bias was observed when comparing the three methodologies, suggesting that caution should be used when comparing results from the FSL and other point-of-care glucometers to reference intervals generated using other methodologies.

Feasibility of precise and reliable glucose quantification in human whole blood samples by 1 tesla benchtop NMR.

The standard procedure for blood glucose measurements is enzymatic testing. This method is cheap, but requires small samples of open blood with direct contact to the test medium. In principle, NMR provides non-contact analysis of body fluids, but high-field spectrometers are expensive and cannot be easily utilized under clinical conditions. Low-field NMR systems with permanent magnets are becoming increasingly smaller and more affordable. The studies presented here aim at exploring the capabilities of low-field NMR for measuring glucose concentrations in whole blood. For this purpose, a modern 1 T benchtop NMR spectrometer was used. Challenges arise from broad spectral lines, the glucose peak locations close to the water signal, low SNR and the interference with signals from other blood components. Whole blood as a sample comprises even more boundary conditions: crucial for reliable results are avoiding the separation of plasma and cells by gravitation and reliable reference values. First, the accuracy of glucose levels measured by NMR was tested using aqueous glucose solutions and commercially available bovine plasma. Then, 117 blood samples from oral glucose tolerance testing were measured with minimal preparation by simple pulse-acquire NMR experiments. The analysis itself is the key to achieve high precision, so several approaches were investigated: peak integration, orthogonal projection to latent structure analysis and support vector machine regression. Correlations between results from the NMR spectra and the routine laboratory automated analyzer revealed an RMSE of 7.90 mg/dL for the best model. 91.5% of the model output lies within the limits of the German Medical Association guidelines, which require the glucose measurement to be within 11% of the reference method. It is concluded that spectral quantification of glucose in whole blood samples by high-quality NMR spectrometers operating at 1 T is feasible with sufficient accuracy.

One-pot, direct glucose detection in human whole blood without using a dilution factor by a magnetic nanozyme with dual enzymatic activity

The necessity of sample pretreatment, the limited absorbance variation in the concentration range of calibration plot are the common restrictions of the colorimetric glucose sensors used with the complex samples. A calibration plot in a concentration range far below the common level of complex biological sample mostly involves to use a high dilution factor for finding the actual glucose level in the complex sample. Glucose oxidase immobilized-Au nanoparticle attached-magnetic SiO2 (GOx@Au@MagSiO2) microspheres were proposed as a new magnetic nanozyme, allowing one-pot and direct determination of glucose concentration in human whole blood without using a sample pretreatment and a high dilution factor. As an unusual approach which is not coherent with the common strategy followed for colorimetric determination of blood glucose level, a calibration plot based on the common range of human whole blood (i.e. 2.8–38.9 mM) is generated with the synthesized nanozyme. GOx was directly linked onto Au nanoparticles (Au NPs) immobilized on the magnetic SiO2 microspheres via a simple protocol, using the thiol groups of its cysteine residues, as a unique property of GOx’s, for the first time. The activity of free GOx could be highly preserved by the selected immobilization protocol. GOx@Au@MagSiO2 microspheres exhibited peroxidase-like activity due to Au NPs immobilized on the magnetic microspheres, together with the glucose oxidation ability originated from GOx linked to Au NPs. The nanozyme was efficiently used for one-pot, direct determination of glucose level in human whole blood in the concentration range of 50–700 mg/dL (i.e. 2.8–38.9 mM).

Clinical utility of plasma progesterone and blood and plasma glucose concentrations in predicting parturition in Holstein cows

An accurate, practical, and low-cost method for predicting parturition is urgently needed in the dairy industry. The objective of this study was to evaluate changes in plasma progesterone concentration ([prog]) and glucose concentration in whole blood ([gluc]b) and plasma ([gluc]p) as predictors of parturition within 6, 12, and 24 h in primiparous and multiparous Holstein cows. Blood samples were obtained daily at approximately 0900 h from 34 primiparous and 72 multiparous Holstein cows in late gestation and the time of calving recorded to the nearest hour. Plasma [prog] was measured using an ELISA, and [gluc]b and [gluc]p using a low-cost point-of-care glucose meter. The optimal cut-point for predicting parturition was determined using binomial logistic regression with general estimating equations, because the data set consisted of repeated measures for each cow. Diagnostic test performance was evaluated by comparing the area under the receiver operating characteristic curve (AUC) and calculating the sensitivity, specificity, and κ at the optimal cut-point for predicting parturition. Plasma [prog] was the most accurate predictor of parturition within 24 h (AUC = 0.96) and 12 h (AUC = 0.93), whereas [gluc]b was the most accurate predictor of parturition within 6 h (primiparous, AUC = 0.96; multiparous, AUC = 0.86). We conclude that a decrease in plasma [prog] is currently the most accurate test for predicting calving within 24 h. Measurement of [gluc]b is a promising new test for the cow-side prediction of parturition in dairy cows due to its accuracy, practicality, and low cost.

High-fat Overfeeding Does Not Exacerbate Rapid Changes in Forearm Glucose and Fatty Acid Balance During Immobilization.

Physical inactivity and high-fat overfeeding have been shown to independently induce insulin resistance. Establish the contribution of muscle disuse and lipid availability to the development of inactivity-induced insulin resistance. 20 healthy males underwent 7 days of forearm cast immobilization combined with a fully controlled eucaloric diet (n = 10, age 23 ± 2 yr, body mass index [BMI] 23.8 ± 1.0 kg·m-2) or a high-fat diet (HFD) providing 50% excess energy from fat (high-fat diet, n = 10, age 23 ± 2 yr, BMI 22.4 ± 0.8 kg·m-2). Prior to casting and following 2 and 7 days of immobilization, forearm glucose uptake (FGU) and nonesterified fatty acid (NEFA) balance were assessed using the arterialized venous-deep venous (AV-V) forearm balance method following ingestion of a mixed macronutrient drink. 7 days of HFD increased body weight by 0.9 ± 0.2 kg (P = 0.002), but did not alter fasting, arterialized whole-blood glucose and serum insulin concentrations or the associated homeostatic model assessment of insulin resistance or Matsuda indices. Two and 7 days of forearm immobilization led to a 40 ± 7% and 52 ± 7% decrease in FGU, respectively (P < 0.001), with no difference between day 2 and 7 and no effect of HFD. Forearm NEFA balance tended to increase following 2 and 7 days of immobilization (P = 0.095). Forearm immobilization leads to a rapid and substantial decrease in FGU, which is accompanied by an increase in forearm NEFA balance but is not exacerbated by excess dietary fat intake. Altogether, our data suggest that disuse-induced insulin resistance of glucose metabolism occurs as a physiological adaptation in response to the removal of muscle contraction.

Precision and accuracy of a point-of-care glucometer in horses and the effects of sample type

Point-of-care glucometry is used commonly in clinical and research settings; however, accuracy and precision of this method are concerns. The objectives of this study were to determine the accuracy of glucometry in adult horses and the precision of duplicate measurements. Blood samples were collected from 62 horses into one plain syringe, one EDTA tube and three fluoride oxalate (FO) tubes. Immediately after collection, glucose concentrations in whole blood were determined, in duplicate, by glucometry from the syringe (plain whole blood [WB] group), EDTA tube (EDTA group) and one FO tube (FO group). One FO sample was used to measure plasma glucose concentration by a laboratory chemistry analyser (LAB group) ≤1 h after collection. The third FO tube was used to measure plasma glucose concentration by glucometry after 3 h storage (FO3hr group).Adequate precision was present for all groups (coefficient of variation: 0.7–3.5%) except WB (5.5–9.4%). Between groups, correlations were significant (P < 0.05; except for WB-EDTA), varied with group comparison, and tended to be lowest for comparisons involving WB. Mean bias was lowest for WB-LAB and greatest for FO-LAB and FO3hr-LAB; however, the limits of agreement were ≥4.65 mmol/L for WB-LAB and ≤2.75 mmol/L for most other comparisons. For the glucometer used, performance was influenced by sample type: WB was unsuitable, while FO or EDTA samples resulted in adequate precision and accuracy, provided under-estimation of glucose concentrations is accounted for by using method-specific reference ranges. Glucometer performance and optimal sample type(s) should be determined prior to use in horses.

Effect of standard clinical procedures on blood glucose concentration in clinically healthy horses.

Blood glucose concentrations fluctuate with stress, but little is known on how it is influenced by clinical procedures. The objective was to investigate the effect of clinical procedures on blood glucose concentration in healthy horses. Prospective, experimental study. Seven hospital-owned research horses were included in the study. A total of 4 horses were sampled either during a control sedation trial or during 3 different student workshops (prepurchase, oral, and rectal examination-the latter 2 with sedation). Blood samples were taken every 15 minutes and glucose concentration in whole blood was measured immediately with a previously validated handheld glucometer until normalization after the end of the workshops. No food was provided during sampling periods. All measured blood glucose concentrations remained within reference interval. A significant increase in blood glucose concentration between baseline and peak was found during sedation (P=0.005) and the oral workshop (P=0.031). A decrease was found during prepurchase examination (P=0.006; before exercising). Peak glucose concentration values between the sedation trial and both the oral (P=0.065) and rectal workshop (P=0.709) were not statistically different. Glucose measurements returned to baseline 1 hour after completion of the workshops. No impact of different clinical procedures on the blood glucose concentration over the effects of sedation was found. It is advisable to wait 1 hour after a procedure to measure blood for glucose concentration in horses.

Direct glucose detection in whole blood by colorimetric assay based on glucose oxidase-conjugated graphene oxide/MnO2 nanozymes

We herein report a facile approach for the preparation of horseradish peroxidase (HRP)-mimic glucose oxidase-conjugated graphene oxide/MnO2 (GOD-GO/MnO2) as new nanozyme to detect the glucose concentration in whole blood. The nano-sized of MnO2 nanoparticles embedded in bovine serum albumin (BSA)-coated GO by in situ growth were evaluated focusing on the principle of HRP-mimic activity catalyzing the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) in the presence of hydrogen peroxide. Furthermore, we constructed dual sensing platforms based on the combination of a plasma separation pad and GOD-GO/MnO2 for direct detection of glucose concentration in whole blood by colorimetric assay without blood sample pretreatment. As a proof-of-concept, a limit of detection of 3.1 mg dL-1 for glucose was obtained with a wide linear quantification range from 25 mg dL-1 to 300 mg dL-1 through visual observation and quantitative analysis, suggesting potential clinical applications in blood glucose monitoring for diabetic patients.

Are 3 minutes good enough for obtaining baseline physiological samples from teleost fish?

A prerequisite to studying the physiological status of wild animals is the ability to obtain blood samples that reflect the condition prior to capture or handling. Based on research in avian taxa, it is recommended that such samples be obtained within 3 min of capture; however, this guideline has not been validated in wild teleosts. The present study addresses the time course of physiological changes in a number of blood metrics across six species of freshwater fish. Fishes were caught using a standardized angling protocol and held in a water-filled trough prior to the collection of a blood sample, via caudal phlebotomy, between 0.5 and 11 min after capture. Changes in whole-blood glucose and lactate concentrations, hematocrit, and plasma cortisol concentrations were assessed. Change-point analyses indicated that blood lactate concentrations and hematocrit did not deviate from baseline values until ∼2–5 min of handling for all species, whereas blood glucose concentrations generally did not deviate significantly from baseline over the 11 min test period. In all species, plasma cortisol concentrations began to increase above baseline between ∼4 and 8 min after capture. Thus, to ensure that blood samples are representative of baseline conditions across multiple metrics, we recommend that sampling be limited to less than 2 min in teleost fishes.

COMPARISON OF WHOLE BLOOD AND PLASMA GLUCOSE CONCENTRATIONS IN GREEN TURTLES ( CHELONIA MYDAS) DETERMINED USING A GLUCOMETER AND A DRY CHEMISTRY ANALYZER.

: We compared glucose concentrations in whole blood and plasma from green turtles ( Chelonia mydas) using a glucometer with plasma glucose analyzed by dry chemistry analyzer. Whole blood glucose (glucometer) and plasma glucose (dry chemistry) had the best agreement ( rs=0.85) and a small negative bias (-0.08 mmol/L).

Association of Neonatal Glycemia With Neurodevelopmental Outcomes at 4.5 Years

Hypoglycemia is common during neonatal transition and may cause permanent neurological impairment, but optimal intervention thresholds are unknown. To test the hypothesis that neurodevelopment at 4.5 years is related to the severity and frequency of neonatal hypoglycemia. The Children With Hypoglycemia and Their Later Development (CHYLD) Study is a prospective cohort investigation of moderate to late preterm and term infants born at risk of hypoglycemia. Clinicians were masked to neonatal interstitial glucose concentrations; outcome assessors were masked to neonatal glycemic status. The setting was a regional perinatal center in Hamilton, New Zealand. The study was conducted from December 2006 to November 2010. The dates of the follow-up were September 2011 to June 2015. Participants were 614 neonates born from 32 weeks' gestation with at least 1 risk factor for hypoglycemia, including diabetic mother, preterm, small, large, or acute illness. Blood and masked interstitial glucose concentrations were measured for up to 7 days after birth. Infants with hypoglycemia (whole-blood glucose concentration <47 mg/dL) were treated to maintain blood glucose concentration of at least 47 mg/dL. Neonatal hypoglycemic episode, defined as at least 1 consecutive blood glucose concentration less than 47 mg/dL, a severe episode (<36 mg/dL), or recurrent (≥3 episodes). An interstitial episode was defined as an interstitial glucose concentration less than 47 mg/dL for at least 10 minutes. Cognitive function, executive function, visual function, and motor function were assessed at 4.5 years. The primary outcome was neurosensory impairment, defined as poor performance in one or more domains. In total, 477 of 604 eligible children (79.0%) were assessed. Their mean (SD) age at the time of assessment was 4.5 (0.1) years, and 228 (47.8%) were female. Those exposed to neonatal hypoglycemia (280 [58.7%]) did not have increased risk of neurosensory impairment (risk difference [RD], 0.01; 95% CI, -0.07 to 0.10 and risk ratio [RR], 0.96; 95% CI, 0.77 to 1.21). However, hypoglycemia was associated with increased risk of low executive function (RD, 0.05; 95% CI, 0.01 to 0.10 and RR, 2.32; 95% CI, 1.17 to 4.59) and visual motor function (RD, 0.03; 95% CI, 0.01 to 0.06 and RR, 3.67; 95% CI, 1.15 to 11.69), with highest risk in children exposed to severe, recurrent, or clinically undetected (interstitial episodes only) hypoglycemia. Neonatal hypoglycemia was not associated with increased risk of combined neurosensory impairment at 4.5 years but was associated with a dose-dependent increased risk of poor executive function and visual motor function, even if not detected clinically, and may thus influence later learning. Randomized trials are needed to determine optimal screening and intervention thresholds based on assessment of neurodevelopment at least to school age.

318 Comparison of a point-of-care glucometer and an automated biochemical analyzer to measure glucose concentrations in whole blood, serum, and plasma from porcine blood samples

318 Comparison of a point-of-care glucometer and an automated biochemical analyzer to measure glucose concentrations in whole blood, serum, and plasma from porcine blood samples

Effects of zilpaterol hydrochloride on growth performance, blood metabolites, and fatty acid profiles of plasma and adipose tissue in finishing steers1

The effects of zilpaterol hydrochloride (ZH) on blood metabolites and fatty acid profiles of plasma and adipose tissue were evaluated in crossbred finishing steers (n = 18, BW 639 ± 12.69 kg) that were stratified by BW and randomly assigned, within strata (block), to receive 0 (control) or 8.33 mg/kg diet DM ZH. Cattle were fed once daily ad libitum in individual feeding pens (9 pens/treatment). Zilpaterol hydrochloride was fed for 23 d and withdrawn 3 d before harvest. Blood samples and measures of BW were taken on d 0, 7, 14, and 21. Concentrations of β-hydroxybutyrate (BHB), glucose, and lactate were determined from whole blood. Nonesterified fatty acids, urea nitrogen (PUN), glucose, lactate, and long-chain fatty acid (LCFA) concentrations were analyzed from plasma. Postharvest, adipose tissue samples (approximately 20 g) from subcutaneous fat covering the lumbar vertebrae were collected after 48 h of refrigeration and analyzed for LCFA profiles. Feeding ZH decreased DMI by 8% (P = 0.03) but did not affect BW gain or efficiency (P = 0.83 and P = 0.56, respectively). Addition of ZH resulted in greater HCW, dressing percentage, and LM area ( P = 0.02, P = 0.08, and P = 0.07, respectively) but did not influence other carcass traits (P > 0.10). A ZH × d interaction was observed for PUN and whole-blood glucose concentrations (P = 0.06), in which concentrations decreased in cattle receiving ZH. Nonesterified fatty acids, BHB, plasma glucose, whole-blood, and plasma lactate concentrations were unaffected by ZH (P > 0.10). Zilpaterol hydrochloride increased plasma concentrations of elaidic (P = 0.03), vaccenic (P = 0.006), and docosapentaenoic acids ( P= 0.08), but LCFA concentrations of adipose tissue were unaffected ( P> 0.10), suggesting no preferential oxidation of specific fatty acids. In conclusion, ZH supplementation decreased PUN concentration possibly due to decreased muscle catabolism, but components of blood related to lipid oxidation were unaffected.

Methods for the determination of glucose in blood. Part 2

The chronological development of destructive and nondestructive methods designed to determine the glucose concentration in plasma, serum, and whole blood is presented in the review. Destructive procedures are divided into spectrophotometric, spectrofluorimetric, diffraction, amperometric, potentiometric, conductometric, chromatographic, gas chromatographic-mass spectrometric, titrimetric, and calorimetric types, as well as reflectance photometry. A brief overview of these methods and the results of comparative tests are given; the procedures are systematized. It is noted that certain types of enzymatic spectrophotometric and amperometric methods have received wide acceptance for analyzes in clinical diagnostic laboratories. Outside clinical laboratories, enzymatic amperometric and spectrophotometric procedures and reflectance photometry procedures using test strips are widely used. Chromatography-mass spectrometry procedures are often applied to certify standard serum samples. Spectrofluorimetric, diffraction, and chromatographic techniques are common in scientific biomedical research. Nondestructive methods like nonenzymatic spectrophotometric, nonenzymatic amperometric, potentiometric, conductometric, titrimetric, and calorimetric procedures, as well as a number of enzymatic spectrophotometric procedures, in most cases, are not used in modern clinical and diagnostic practice.

Effect of subcutaneous insulin detemir on glucose flux and lipolysis during hyperglycaemia in people with type 1 diabetes

To investigate, using a novel non-steady-state protocol, the differential effects of subcutaneous (s.c.) detemir and NPH insulin on glucose flux and lipid metabolism after insulin withdrawal. After a period of insulin withdrawal resulting in whole-blood glucose concentration of 7 mmol/l, 11 participants (five men, mean age 41.0 years, mean body mass index 25 kg/m(2)) with type 1 diabetes (mean glycated haemoglobin concentration 57 mmol/mol, mean diabetes duration 14 years) received 0.5 units per kg body weight s.c. insulin detemir or NPH insulin in random order. Stable isotopes of glucose and glycerol were infused intravenously throughout the study protocol. Glucose concentration decreased after insulin treatment as a result of suppression of endogenous glucose production, which occurred to a similar extent with both detemir and NPH insulin. The rate of glucose disappearance (Rd) was not increased significantly with either type of insulin. When the effect of detemir and NPH insulin on glucose flux at glucose concentrations between 9 and 6 mmol/l was examined, glucose rate of appearance (Ra) was similar with the two insulins; however, glucose Rd was greater with NPH insulin than with detemir at glucose concentrations of 8.0, 8.5, 7.0 and 6.0 mmol/l (p < 0.05) The percentage change in glycerol Ra, a measure of lipolysis, was greater in the NPH group than in the detemir group (p = 0.04). The results of the study are consistent with the hypothesis that detemir has a lesser effect on the periphery, as evidenced by a lesser effect on peripheral glucose uptake at specific glucose concentrations.