Maximum Glucose Concentration Research Articles

Glycemic responses to intermittent hepatic inflow occlusion in living liver donors.

The occurrence of glycemic disturbances has been described for patients undergoing intermittent hepatic inflow occlusion (IHIO) for tumor removal. However, the glycemic responses to IHIO in living liver donors are unknown. This study investigated the glycemic response to IHIO in these patients and examined the association between this procedure and the occurrence of hyperglycemia (blood glucose > 180 mg/dL). The data from 154 living donors were retrospectively reviewed. The decision to perform IHIO was made on the basis of the extent of bleeding that occurred during parenchymal dissection. One round of IHIO consisted of 15 minutes of clamping and 5 minutes of unclamping the hepatic artery and portal vein. Blood glucose concentrations were measured at predetermined time points, including the start and end of IHIO. Repeated hyperglycemic episodes occurred after unclamping. The mean maximum intraoperative blood glucose concentration was greater in donors who underwent ≥3 rounds of IHIO versus those who underwent 1 or 2 rounds (169 ± 30 versus 149 ± 31 mg/dL, P = 0.005). The incidence of intraoperative hyperglycemia was also greater in donors who underwent ≥3 rounds of IHIO versus those who underwent 1 or 2 rounds (38.7% versus 7.7%, odds ratio = 7.1, 95% confidence interval = 2.5-20.4, P < 0.001). Donors who did not undergo IHIO and those who underwent 1 or 2 rounds of IHIO exhibited similar maximum glucose concentrations and similar incidence rates of hyperglycemia. In conclusion, IHIO induced repeated hyperglycemic responses in living donors, and donors who underwent ≥3 rounds of IHIO were more likely to experience intraoperative hyperglycemia. These results provide additional information on the risks and benefits of IHIO in living donors.

Effect of Cinnamon Tea on Postprandial Glucose Concentration.

Glycaemic control, in particular at postprandial period, has a key role in prevention of different diseases, including diabetes and cardiovascular events. Previous studies suggest that postprandial high blood glucose levels (BGL) can lead to an oxidative stress status, which is associated with metabolic alterations. Cinnamon powder has demonstrated a beneficial effect on postprandial glucose homeostasis in animals and human models. The purpose of this study is to investigate the effect of cinnamon tea (C. burmannii) on postprandial capillary blood glucose level on nondiabetic adults. Participants were given oral glucose tolerance test either with or without cinnamon tea in a randomized clinical trial. The data revealed that cinnamon tea administration slightly decreased postprandial BGL. Cinnamon tea ingestion also results in a significantly lower postprandial maximum glucose concentration and variation of maximum glucose concentration (p < 0.05). Chemical analysis showed that cinnamon tea has a high antioxidant capacity, which may be due to its polyphenol content. The present study provides evidence that cinnamon tea, obtained from C. burmannii, could be beneficial for controlling glucose metabolism in nondiabetic adults during postprandial period.

Alkaline Delignification of Oil Palm Empty Fruit Bunch Using Black Liquor from Pretreatment

Bioethanol is providing one window of potential alternative energy. Lignocellulosic from oil palm empty fruit bunch (EFB) could be a promising bioethanol raw material because of abundant resources and it will not interfere food supply. Pretreatment is a one of the steps in the bioconversion of lignocellulosic material. Pretreatment also contributes the largest cost in the bioethanol production and produces black liquor as a wastewater that provides environmental impacts. Black liquor recycling is expected to increase economic efficiency by reducing the cost of pretreatment and the amount of wastewater. This experiment used black liquor and its mixture with NaOH solution as pretreatment solution. The pretreatment process was conducted in a 5-liter reactor at 150oC. The result using only black liquor gave the lowest value compared to other solutions. The addition of NaOH solution into black liquor caused increasing the cellulose content and delignification EFB by 57.18% and 51.62%, respectively. The maximum glucose concentration in the variation of pretreatment solutions: NaOH 2.5 M, black liquor, and black liquor with NaOH solution addition were 93.80 g l-1, 52.55 g l-1 and 87.05 g l-1, respectively, at a pretreated biomass loading of approximately 15% (w/v) with an enzyme dosage of 30 FPU g/dry biomass.

Verapamil decreases the glucose-lowering effect of metformin in healthy volunteers.

The organic cation transporter 1 (OCT1) plays a key role in the cellular transport of metformin and its subsequent glucose-lowering effect. A recent non-clinical study reported that metformin uptake into hepatocytes is regulated via OCT1, and that uptake was strongly inhibited by verapamil. Therefore, we investigated the effects of verapamil co-administration on the pharmacokinetics and pharmacodynamics of metformin in humans. We evaluated the pharmacokinetics and the anti-hyperglycaemic effects of metformin using an oral glucose tolerance test (OGTT) in 12 healthy participants, before (day 1) and after metformin treatment (day 2), and again on days 15 and 16 after co-administration with verapamil. Verapamil inhibited the ability of metformin to reduce maximum blood glucose concentrations (ΔGmax ) by 62.5% (P = 0.008) and decreased the area under the glucose concentration-time curve (ΔAUCgluc ) by 238% (P = 0.015). However, verapamil did not significantly alter the Cmax and the AUC of metformin, nor its renal clearance. Our results suggest that verapamil remarkably decreases the glucose-lowering effect of metformin, possibly by acting as a competitive inhibitor of OCT1.

Apolipoprotein E Genotype Has a Modest Impact on the Postprandial Plasma Response to Meals of Varying Fat Composition in Healthy Men in a Randomized Controlled Trial

Background:Apolioprotein E (APOE) genotype is reported to influence a person’s fasting lipid profile and potentially the response to dietary fat manipulation. The impact of APOE genotype on the responsiveness to meals of varying fat composition is unknown. Objective:We examined the effect of meals containing 50 g of fat rich in saturated fatty acids (SFAs), unsaturated fatty acids (UNSATs), or SFAs with fish oil (SFA-FO) on postprandial lipemia. Method:A randomized, controlled, test meal study was performed in men recruited according to the APOE genotype (n = 10 APOE3/3, n = 11 APOE3/E4). Results:For the serum apoE response (meal × genotype interaction P = 0.038), concentrations were on average 8% lower after the UNSAT than the SFA-FO meal in APOE4 carriers (P = 0.015) only. In the genotype groups combined, there was a delay in the time to reach maximum triacylglycerol (TG) concentration (mean ± SEM: 313 ± 25 vs. 266 ± 27 min) and higher maximum nonesterified fatty acid (0.73 ± 0.05 vs. 0.60 ± 0.03 mmol/L) and glucose (7.92 ± 0.22 vs. 7.25 ± 0.22 mmol/L) concentrations after the SFA than the UNSAT meal, respectively (P ≤ 0.05). In the Svedberg flotation rate 60–400 TG-rich lipoprotein fraction, meal × genotype interactions were observed for incremental area under the curve (IAUC) for the TG (P = 0.038) and apoE (P = 0.016) responses with a 58% lower apoE IAUC after the UNSAT than the SFA meal (P = 0.017) in the E4 carriers. Conclusions:Our data indicate that APOE genotype had a modest impact on the postprandial response to meals of varying fat composition in normolipidemic men. The physiologic importance of greater apoE concentrations after the SFA-rich meals in APOE4 carriers may reflect an impact on TG-rich lipoprotein clearance from the circulation. This trial was registered at clinicaltrials.gov as NCT01522482.

Influence of dual salt on the pretreatment of sugarcane bagasse with hydrogen peroxide for bioethanol production

Abstract This study presents the influence of different dual salts on the pretreatment of sugarcane bagasse (SCB) with H2O2 for the production of bioethanol. The results showed better cellulose recovery and delignification for MnSO4·H2O and ZnO system. At optimized conditions (1% H2O2, 1 g SCB, 30 min, 100 °C and 0.5:100 g/mL), the maximum cellulose recovery of 93.42 ± 1.74%, and delignification of 74.18 ± 1.51% were obtained. The SCB was subjected to dilute acid hydrolysis, and under optimized conditions, the maximum glucose, xylose and arabinose concentrations obtained were 15.26 ± 0.37 g/L, 11.62 ± 0.21 g/L and 3.58 ± 0.17 g/L, respectively. The results of SEM, FTIR and XRD analysis suggested that the proposed method effectively removed lignin and disrupted the crystal structure of cellulose for a better hydrolytic process. The fermentation of hydrolyzate with Saccharomyces cerevisiae showed maximum bioethanol production of 13.1 g/L at the end of 72 h and bioethanol yield of 0.184 g/g SCB.

Evaluation of Mixed Cellulase-Amylase System on Enzymatic Hydrolysis Reaction Using Response Surface Methodology

The ability of mixed enzyme (ɑ-amylase and cellulase) immobilized via cross-linking method with 3% of glutaraldehyde (GA) on polymeric membrane containing 20 wt% of polysulphone and 80 wt% of 1-methyl-2-pyrrolidone (NMP)/polyvinylpyrrolidone (PVP) to catalyze the complex structure (starch and cellulose) into glucose was investigated in this study. Central Composite Face Centered Design (CCFD) with alpha equal to 1 (ɑ=1) were used to evaluate the effects of pH, temperature, percent of enzyme dosage and percent of substrate concentration on enzymatic hydrolysis process. Maximum glucose concentration (g/L) was obtained at 50°C, pH 6.5, 3% of enzyme dosage and 3% of substrate concentration. The study indicated that only substrate and enzyme ratio play significant role (P &lt; 0.1) in maximizing glucose production within pH, temperature, substrate and enzyme dosage range of pH5-8, 30-70°C, 1-5w/v%, and 1-5w/v% respectively. Kinetic enzyme using Lineweaver-Burk plotting suggested that Km and Vmax for the mixed enzyme in this process were 9.6 g/L and 0.3571 U/mg respectively.

Pharmacodynamic activity of the AKT inhibitor AZD5363 in patients with advanced solid tumors.

2541 Background: AZD5363 is an ATP competitive small molecule inhibitor of AKT1, AKT2 and AKT3 and is currently in phase 1 and 2 clinical trials in breast, gynaecological and prostate cancer. In pre-clinical tumour xenograft models, AZD5363 inhibited the phosphorylation of AKT substrates PRAS40 and GSK3β in tumour tissue. Methods: Tumour biopsies were obtained from patients with advanced solid tumours in Western and Japanese phase 1 studies. Pharmacodynamic activity of AZD5363 in formalin fixed paraffin embedded tumour tissue was measured by immunohistochemistry (IHC) for total and phospho-AKT, phospho-PRAS40 and phospho-GSK3β using commercially available antibodies. IHC was quantified by H-score (sum of % tumour cells with 0=negative; 1=weak; 2=moderate; 3=strong staining) based on the results from 3 sections for each antibody. Inhibition of PRAS40 phosphorylation in hair follicles obtained 4 hours after dosing was measured by immunofluorescence and quantified by image analysis. Results: Paired tumour biopsies at baseline and after approximately 2 weeks dosing were obtained from patients on continuous and intermittent dosing schedules. Inhibition of GSK3β and PRAS40 phosphorylation of >30% or >50% respectively was seen in 4/7 (GSK3β) and 2/8 (PRAS40) tumours at tolerated doses of AZD5363. Phospho-AKT was increased in 4/7 (AKT-Thr308) and 4/5 (AKT-Ser473) tumours commensurate with the mechanism of action of AZD5363. Hair follicle PRAS40 phosphorylation was reduced by >50% in 22/71 patients and showed evidence of an exposure related response with an IC50 of 2μM total plasma concentration. Blood glucose also demonstrated an exposure response relationship with maximum glucose concentration correlating with drug plasma Cmax. Conclusions: Inhibition of AKT substrate phosphorylation in tumour biopsies from advanced cancer patients with a range of solid tumours was qualitatively comparable to that observed in preclinical models showing tumour growth inhibition at clinically achievable exposures. Clinical trial information: NCT01226316; NCT01353781.

Ethanol Production from High Solids Loading of Alkali-Pretreated Sugarcane Bagasse with an SSF Process

A fed-batch process and high-temperature simultaneous saccharification and fermentation (SSF) process were investigated to obtain high sugar yield and ethanol concentration. Different amounts of alkali-pretreated sugarcane bagasse were added during the first 24 h. For the highest final dry matter (DM) content of 25% (w/v), a maximal glucose and total sugar concentration of 79.53 g/L and 135.39 g/L, respectively, were achieved with 8.3 FPU/g substrate after 120 h of hydrolysis. Based on the hydrolysis experiment, two processes for ethanol production from sugarcane bagasse, simultaneous saccharification and fermentation (SSF) and separate hydrolysis and fermentation (SHF), were also compared using S. cerevisiae. The results indicated that ethanol concentration and yield in the SHF were higher, while ethanol productivity (gram per unit volume and over time) was lower. For 25% substrate loading, the ethanol productivity and ethanol concentration could reach 0.38 g.L-1.h-1 and 36.25 g/L SSF in 96 h, respectively, while that of SHF could reach 0.32 g.L-1.h-1, with an ethanol concentration of 47.95 g/L in 152 h for SHF. When high-temperature simultaneous saccharification and fermentation (SSF) process was performed by using Kluyveromyces marxianus NCYC 587 at 42 °C, 42.21 g/L ethanol (with an ethanol productivity of 0.44 g.L-1.h-1) was produced with 25% dry matter content and 8.3 FPU cellulase/g substrate, which meant 16.4% more ethanol when compared with SSF of S. cerevisiae.

Effects of Proton Pump Inhibitors on Metformin Pharmacokinetics and Pharmacodynamics

As inhibitors of organic cation transporters (OCTs), proton pump inhibitors (PPIs) may affect the plasma levels of metformin, an OCT substrate. We investigated the effects of two PPIs, pantoprazole and rabeprazole, on metformin pharmacokinetics and glucose levels in healthy subjects. In this open, randomized, six-sequence, three-period crossover study, 24 participants were administered metformin, either alone or in combination with pantoprazole or rabeprazole. The plasma concentrations of metformin and serum concentrations of glucose after a 75-g oral glucose tolerance test (OGTT) were determined. The area under the concentration-time curve (AUC) for metformin was 15% and 16% greater following coadministration with pantoprazole and rabeprazole, respectively. The maximum plasma metformin concentrations (Cmax) also increased by 15% and 22%, respectively, compared with when it was administered without the PPIs. The percentage change in the AUC for glucose concentration versus time for metformin plus rabeprazole was significantly lower than that for metformin plus pantoprazole [geometric mean ratio: 0.96 (90% confidence interval: 0.92-0.99) and 0.77 (0.63-0.93), respectively]. There was no significant difference in the maximum glucose concentration. In conclusion, concomitant administration of PPIs with metformin significantly increased plasma metformin exposure, but the effects on glucose disposition were minor and varied depending on the PPI administered.

A prospective study on hyperglycemia and retinopathy of prematurity

Retinopathy of prematurity (ROP) constitutes a significant morbidity in premature infants that can lead to blindness. Multiple retrospective studies have identified neonatal hyperglycemia as a risk for developing ROP. However, in the absence of any reported prospective study, it is not clear whether hyperglycemia is associated with ROP independent of the commonly associated comorbidities. The objective of this study was to investigate whether hyperglycemia in premature infants is independently associated with ROP. 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 h daily for 7 days. For any glucose reading<50 or>150 mg dl(-1), serum sample was sent to the laboratory for confirmation. Hyperglycemia was defined as any blood glucose level⩾150 mg dl(-1). ROP patients were compared with non-ROP patients in a bivariate analysis. Variables significantly associated with ROP were studied in a logistic regression model. A total of 65 patients were enrolled with gestational age 31.1±1.2 weeks and birth weight 1385±226 g. Thirty-one patients (48%) were identified with hyperglycemia. On eye examination, 19 cases (29.2%) had ROP (13 with stage 1, 4 with stage 2 and 2 with stage 3). There were more cases of ROP in the hyperglycemia group compared with the euglycemia group (45% vs 15%, P=0.007). Patients who developed ROP had significantly 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 significant variables, average blood glucose in the first week of life was the factor independently associated with ROP with an odds ratio of: 1.77 (95% confidence interval: 1.08 to 2.86), P=0.024. In a cohort of premature infants, elevated average blood glucose concentrations in the first week of life is independently associated with the development of ROP.

A novel algorithm in the management of hypoglycemia in newborns.

Study Objective. To evaluate the safety of a new protocol in comparison to the standard protocol for managing hypoglycemia in neonates. Methods. Open label RCT-pilot study. Neonates admitted to NICU with hypoglycemia and requiring intravenous fluids were included. Fifty-seven eligible neonates were randomly allocated to either intervention group (starting fluids with 10% dextrose and increments of 1.5%) or standard protocol group (GIR of 6 mg/kg/min with increments of 2 mg/kg/min) till control of hypoglycemia. Primary outcome of the study was to know proportion of infants with subsequent hypoglycemia and hyperglycemia after enrolment. Results. The initial GIR (6 ± 0 mg/kg/min versus 4.8 ± 1.4 mg/kg/min, P < 0.001), the mean maximum GIR (6.7 ± 1.6 mg/kg/min versus 5.6 ± 2 mg/kg/min, P = 0.03), the maximum concentration of glucose infused (13.8 ± 2.9% versus 10.9 ± 1.9%, P < 0.001), and the total amount of glucose infused were significantly lower in the intervention group. The mean maximum blood sugar was significantly higher (129 ± 57 mg/dL versus 87 ± 30 mg/dL, P = 0.001) and there was a trend towards high proportion of infants with Hyperglycemia in the standard protocol group (n = 10, 39% versus n = 5, 16%, P = 0.07). The median difference between the highest and the lowest recorded sugar for any infant was significantly higher in the standard protocol group (median 93 mg/dL, IQR 52 to 147 mg/dL versus median 50 mg/dL, IQR 38 to 62.5 mg/dL, P = 0.03). Conclusion. A new and novel algorithm in the management of hypoglycemia in neonates is as safe as the standard protocol and requires further testing before routine implementation.

Production of Bioethanol in a Second Generation Prototype from Pine Wood Chips

This paper deals with the production of bioethanol from ligno-cellulosic biomass, in particular a softwood biomass from forestry sector is tested: pine wood chip is a residual biomass obtained from coppice maintenance with a very interesting potential. Second generation bioethanol production prototype from ligno-cellulosic biomass consists of the following monitored parts: steam production system, steam explosion reactor for biomass pretreatment (temperature range 180-240°C), enzymatic hydrolyser, fermenter and distiller. The maximum system size is around 2-3kg input biomass each cycle.Selected biomass are tested modifying reaction temperature and retention time of the process and optimizing severity parameter (logR0 between 2.7 and 4.6). Enzymatic hydrolysis is conducted with Ctec2, cellulase complex which consists of a blend of aggressive cellulases (endocellulase and exocellulase), β-glucosidases and hemicellulase, while Saccharomyces cerevisiae yeast (“red ethanol”) is used for the fermentation stage. During hydrolysis and fermentation stages intermediate collections at different time are carried out and samples analyzed in order to evaluate the progress of each phase (maximum glucose concentration obtained 18.8mg/ml).The results are presented in terms of raw (cellulose content around 32%) and steam exploded material composition, hydrolyzed sugars and acids content in samples, ethanol content after fermentation at different retention time. Both hydrolysis and fermentation are analyzed comparing real and theoretical efficiency. Finally, mass flows in the different selected conditions are evaluated providing a results in terms of ethanol percentage in function of raw material weight. As a result from 100g of raw material dry basis (32g of cellulose), 10.6g of ethanol were obtained.

182-P: EFFECT OF GLUCOSE AND ALTERNATIVE SWEETENERS (FRUCTOSE, ASPARTAME AND REBAUDIOSIDE A) ON ENDOTHELIAL PROGENITOR CELLS

The twin epidemics of obesity and Type 2 diabetes continue to increase in industrialized nations. Approximately two thirds of adult Americans and Western Countries are currently overweight or obese and therefore at increased risk for a number of deleterious health conditions including Type 2 diabetes and Cardiovascular Disease (CVD). Consumption of sugar-sweetened beverages may be one of the relevant dietary causes of metabolic disorders. Therefore, substituting sugar with low-calorie sweeteners may be n efficacious weight management strategy. Since Endothelial Progenitor Cells (EPC) are involved in cardiovascular tissue regeneration, we tested the effects of glucose and alternative sweeteners (fructose, aspartame and rebaudioside A) on EPCs. Early-EPCs were isolated from total peripheral blood of healthy human donors and treated with different concentration of D-glucose, fructose, aspartame and rebaudioside A for 4 days. EPC number was evaluated by flow cytometry analysis using CD34 and KDR (CD309/VEGFR-2) monoclonal antibodies. As partially expected, high glucose level severely impaired EPC number. Indeed, CD34+/KDR+ dual positive cells were reduced of about 70% at the maximum glucose concentration used. Differently, the other molecules tested were able to reduce the number of total KDR+ cells, but not CD34+/KDR+ dual positive cells. Endothelial dysfunction and reduced new blood vessel growth during vascular complication in either Type 1 or Type 2 diabetes, is known to be strictly related to altered number and function of circulating EPCs. The pathogenic role of reduced bioactivity of EPCs is correlated to increased rate of CVD. These preliminary findings suggest that these alternative sweeteners do not alter CD34+/KDR+ dual positive EPC number, although they can alter endothelial cell number through other cellular molecular pathogenic mechanisms.

Glargine insulin for treatment of naturally occurring diabetes mellitus in dogs

To evaluate the effects of twice-daily glargine insulin administration in dogs with diabetes mellitus. Open-label, prospective clinical trial. 10 dogs with naturally occurring diabetes mellitus. Dogs with poorly regulated or newly diagnosed diabetes mellitus were enrolled if their owners agreed to return them to the hospital at 1- to 3-week intervals for 4 follow-up visits. During each follow-up visit, blood glucose concentrations were measured every 2 hours for at least 10 hours after feeding a diet high in insoluble fiber and after administration of glargine insulin (time 0). The initial glargine insulin dosage was 0.5 U/kg (0.23 U/lb) SC twice daily. All dogs had well-regulated diabetes mellitus at a mean ± SD of 38 ± 14 days (median, 43 days; range, 7 to 55 days) following study enrollment. At the time diabetes mellitus was well regulated, mean glargine insulin dosage was 0.5 ± 0.15 U/kg (0.23 ± 0.068 U/lb; median, 0.5 U/kg; range, 0.32 to 0.67 U/kg [0.15 to 0.30 U/lb]) twice daily, and 3 dogs were receiving a dosage < 0.4 U/kg (0.18 U/lb). In dogs with well-regulated diabetes mellitus, the mean minimum blood glucose concentration (163 ± 89 mg/dL; 95% confidence interval, 100 to 227 mg/dL) was detected 2 hours after administration of glargine insulin and the mean maximum blood glucose concentration (230 ± 95 mg/dL; 95% confidence interval, 64 to 323 mg/dL) was detected 12 hours after administration of glargine insulin. There was no significant difference between mean minimum and mean maximum blood glucose concentrations nor were there significant differences between blood glucose concentrations measured at other time points. Blood glucose concentration < 80 mg/dL was measured at least once in 7 of 10 dogs. Results of the present study suggested that, in diabetic dogs fed a diet high in insoluble fiber, glargine insulin is a peakless insulin that does not induce a distinct blood glucose concentration nadir. For glargine insulin, 0.3 U/kg (0.136 U/lb) SC twice daily is recommended as an initial dosage.

Enhanced enzymatic hydrolysis of pretreated almond-tree prunings for sugar production

Almond-tree prunings (ATP), an agricultural residue largely available in Mediterranean countries, were pretreated with either hot water or dilute sulphuric acid at 180–230°C. Solids derived from hot water pretreatments were further submitted to alkaline peroxide delignification. In addition, all solids obtained from the three mentioned processes were hydrolysed by cellulases and β-glucosidases to investigate their enzymatic digestibilities. Hot water pretreatment led to high oligosaccharide yields (18.2g/100g ATP at 190°C) while dilute acid pretreatment provided the highest monosaccharide yields (24.0g/100g ATP at 190°C) along with low concentrations of fermentation inhibitors. Glucose yields from enzymatic hydrolysis were strongly affected by both pretreatment type and pretreatment temperature. The highest temperature assayed for both hydrothermal and dilute sulphuric acid pretreatment maximized the glucose recovery (49.2% and 72.8%, respectively) while solids derived from alkaline peroxide treatment achieved maximal glucose concentrations (41.9g/L, 58.4% of potential yield).

Enzymatic hydrolysis optimization of sweet potato (Ipomoea batatas) peel using a statistical approach

In this work, two-step enzymatic hydrolysis of sweet potato peel was optimized. The effects of time, enzyme dose and temperature on glucose concentration were investigated. The Box-Behnken design was applied and a total of 17 experimental runs were generated for each step. For the liquefaction step, an ANOVA test showed the quadratic model obtained to be significant (p < 0.05). The statistical model predicted the maximum glucose concentration to be 126.66 g/L at a temperature of 56.4 ºC, α-amylase dose 1% (v/v) and time 60 min. A quadratic model was also obtained for the saccharification step and the model was also significant (p < 0.05). The statistical model for the second step predicted the maximum glucose concentration to be 178.39 g/L, established at the temperature of 45 ºC, glucoamylase dose 1% (v/v) and time 60 min. The optimized liquefaction and saccharification conditions were validated with the actual glucose concentrations of 126.03 and 176.89 g/L, respectively.

The Hyperglycemic Response to Major Noncardiac Surgery and the Added Effect of Steroid Administration in Patients With and Without Diabetes

The pattern and magnitude of the hyperglycemic response to surgical stress, the added effect of low-dose steroids, and whether these differ in diabetics and nondiabetics remain unclear. We therefore tested 2 hypotheses: (1) that diabetics show a greater increase from preoperative to intraoperative glucose concentrations than nondiabetics; and (2) that steroid administration increases intraoperative hyperglycemia more so in diabetics compared with nondiabetics. Patients scheduled for major noncardiac surgery under general anesthesia were enrolled and randomized to preoperative IV 8 mg dexamethasone or placebo, stratified by diagnosis of diabetes. Patients were part of a larger underlying trial (the Dexamethasone, Light Anesthesia and Tight Glucose Control [DeLiT] Trial). IV insulin was given when glucose concentration exceeded 215 mg/dL. The primary outcome measure was the change in glucose from the preoperative to maximal intraoperative glucose concentration. We also report the time-dependent pattern of intraoperative hyperglycemia. Ninety patients (23% with diabetes) were randomized to dexamethasone, and 95 (29% with diabetes) were given placebo. The mean ± SD change from preoperative to maximal intraoperative glucose concentration was 63 ± 69 mg/dL in diabetics and 72 ± 45 mg/dL in nondiabetics. The mean covariable-adjusted change (95% confidence interval) in nondiabetics was 29 (13, 46) mg/dL more than in diabetics (P < 0.001). For all patients combined, mean glucose increased slightly from preoperative to incision, substantially from incision to surgery midpoint, and then remained high and fairly stable through emergence, with nondiabetic patients showing a greater increase (P < 0.001). For nondiabetics, the mean increase in glucose concentration (97.5% CI) was 29 (9, 49) mg/dL more in patients given dexamethasone than placebo (P = 0.0012). However, there was no dexamethasone effect in diabetics (P = 0.99). Treatment of intraoperative hyperglycemia should account for the hyperglycemic surgical stress response trend depending on the stage of surgery as well as the added effects of steroid administration. Denying steroid prophylaxis for postoperative nausea and vomiting for fear of hyperglycemic response should be reconsidered given the limited effect of steroids on intraoperative blood glucose concentrations.

Characterization and effect of clarified araçá (Psidium guineenses Sw.) juice on postprandial glycemia in healthy subjects

Brazilian native fruits are excellent sources of bioactive compounds of phenolic nature. Some of these compounds are able to inhibit carbohydrate- metabolizing enzymes (in vitro), α-amylase and α-glucosidase, delaying carbohydrate digestion. This study aimed to evaluate the effect of clarified araçá (Psidium guineenses Sw.) juice on postprandial glycemia in humans after consumption of 25 g of available carbohydrates (approximately 50 g of white bread) and characterize the phenolic compounds and in vitro antioxidant capacity of araçá juice and pulp. The results showed that the clarified juice had a positive effect on postprandial glycemia reducing the total amount of glucose absorbed, lengthening the time to reach maximum blood glucose concentration, reducing glucose incremental velocity, and decreasing glucose incremental percentage. Both frozen pulp and clarified juice had high amounts of phenolic compounds, antioxidant capacity, and proanthocyanidins, among which oligomers (monomers to tetramers), pentamers, hexamers, heptamers, octamers, nonamers, decamers, and polymers were detected, and they are probably associated with in vivo effects.

Bioethanol production from Yarrowia lipolytica Po1g biomass

Bioethanol production from the yeast Yarrowia lipolytica biomass was studied. The effects of temperature (90-150°C) and H2SO4 concentration (2-15%w/w) on the saccharification of biomass at a hydrolysis time of 1h were investigated. A maximum glucose concentration of 35.89 g/L can be produced from defatted biomass using 6% H2SO4 at 120°C. Subcritical water (SCW) pretreatment has negligible effect on maximizing glucose yield. Only 14.53 g/L glucose can be produced using 6% H2SO4 at 120°C if un-defatted biomass was used. The highest ethanol concentration achieved was 13.39 g/L with a corresponding ethanol yield of 0.084 g/g dry biomass (0.38 g ethanol/g glucose).