Decrease In Glucose Concentration Research Articles

The vasodilating effect of a Hintonia latiflora extract with antidiabetic action

In the present study, it is shown for the first time that an extract of Hintonia latiflora (HLE) which is used as an antidiabetic herbal medicine, is not only able to decrease blood glucose concentration but additionally exerts a vasodilating effect. Accordingly, this extract might have a positive influence on diabetes-associated dysfunction of blood vessels.The vasodilating effect was demonstrated in vitro in aortic rings of guinea pigs as well as in vivo in rabbits. Aortic rings pre-contracted with noradrenaline (NA) could completely be relaxed by HLE (EC50: 51.98mg/l). In contrast, potassium-induced contractions were not diminished by HLE. Therefore, it can be suggested that the vasodilating effect of HLE is primarily the result of an inhibition of G protein-induced increase in intracellular calcium and not of a blockade of voltage-operated L-type calcium channels.The neoflavonoid coutareagenin (COU), a constituent of HLE which in part is responsible for the blood glucose-lowering effect of HLE, also relaxed NA-induced contractions of aortic rings (EC50: 32.55mg/l) and only weakly inhibited potassium-induced contractions.Experiments in aortic rat cells revealed that calcium transients evoked by vasopressin were suppressed by 60mg/l COU supporting the idea of an inhibition of G protein-induced intracellular calcium release by a constituent of HLE.To study the effect of HLE on vascular tone under in vivo conditions, ultrasound measurements were carried out in conscious rabbits which received a single oral dose of HLE. Under the influence of HLE, a vasodilation combined with a lowering of blood flow velocity could be observed in the abdominal aorta and the common carotid artery. Additionally, a decrease in blood glucose concentration in the HLE group occurred.The combination of a blood glucose-lowering with a vasodilating effect may be helpful for reducing angiopathies, typical long-term complications in patients with diabetes mellitus.

Non-invasive method to detect the changes of glucose concentration in whole blood using photometric technique.

A non-invasive method is developed to monitor rapid changes in blood glucose levels in diabetic patients. The system depends on an optical cell built with a LED that emits light of wavelength 535nm, which is a peak absorbance of hemoglobin. As the glucose concentration in blood decreases, its osmolarity also decreases and the Red Blood Cells (RBCs) swell and decrease the path length absorption coefficient. Decreasing absorption coefficient increases the transmission of light through the whole blood. The system was tested with a constructed optical cell that held whole blood in a capillary tube. As expected the light transmitted to the photodiode increases with decreasing glucose concentration. The average response time of the system was between 30-40 seconds.

Effects of Ficus thonningii extracts on the gastrointestinal tract and clinical biochemistry of suckling rats.

Ficus thonningii is commonly used in traditional medicine across the African continent. We investigated the effects of crude Ficus thonningii extracts on growth, morphology and morphometry of the abdominal viscera and clinical biochemistry of neonatal rats. Forty, 6-day old Sprague Dawley rat pups were orally gavaged once daily with either low (50 mg.kg(-1) b.w) or high (500 mg.kg(-1) b.w) doses of aqueous or methanolic F. thonningii leaf extracts while the control received distilled water. After 7 days of treatment, the pups were euthanased and gross morphometric measurements of the abdominal visceral organs were recorded. Samples of the liver, caecum and proximal small intestine were processed for histology. Plasma biochemical parameters were analysed colorimetrically. High methanolic doses of F. thonningii extracts exhibited trophic effects on the stomach while both aqueous and methanolic extracts had trophic effects on the ceacal mucosa of rats. No significant growth-promoting effects were observed in other visceral organs. Histological analysis revealed no mucosal damage or necrosis. Clinical biochemistry parameters were not abnormally altered. There was a significant decrease (p<0.05, ANOVA) in the plasma concentration of non-fasting glucose in the high methanolic group but triglycerides and cholesterol were unaltered. The findings suggest that at low doses, F. thonningii extracts can be safely used without the risk of any disruption in the structural integrity of the neonatal rat GIT and function of the liver and kidneys.

Effect of nano-magnesium oxide on glucose concentration and lipid profile in diabetic laboratory mice

Nano-sized drugs have better distribution than their identical forms. Magnesium is the cofactor of various enzymes in lipid and glucose metabolism. In this study, the effect of nano-magnesium oxide (nano-MgO) on glucose concentration and lipid profile in diabetes induced mice was evaluated in 21 laboratory mice. Mice were randomly divided into three equal groups (control, treatment, and placebo). Diabetes was induced in treatment and placebo group by injection of 60 mg/kg streptozotocin while control group was injected by saline. Treatment group was injected by 2 mg/kg of nano-MgO every 48 hours until the day 45. Serum glucose was measured at 3, 46, and 48 days. Concentration of triglyceride (TG), cholesterol, high density lipoprotein (HDL) and low density lipoprotein (LDL) was measured at day 48. Treatment and placebo group had higher glucose level at day 3 but treatment group at days 46 and 48 had lower glucose levels than placebo group. Diabetic mice had higher levels of TG, cholesterol, LDL and lower levels of HDL than control group in their serum samples. Treatment with MgO ameliorated change in glucose, TG, HDL and LDL level in treated mice. Our study has showed that administration of nano-MgO decreased glucose concentration and ameliorated TG, HDL and LDL levels in diabetes induced mice.

Chemical Meningitis after Spinal or Epidural Anesthesia

Background: Chemical meningitis results from foreign materials causing inflammation to the meninges covering the brain and spinal cord. Cerebrospinal fluid (CSF) study of chemical meningitis mimics bacterial meningitis. Case Report: We report three cases of chemical meningitis after spinal or epidural anesthesia with mepivacaine or bupivacaine. They experienced mental change or seizure. The results of CSF study revealed increased polymorphonuclear cell count and protein level and decreased glucose concentration. Gram staining and bacterial culture of CSF were all negative. We started empirical antibiotics and corticosteroids immediately and the patients were rapidly improved. Concclusion: The chemical meningitis should be differentiated in bacterial meningitis because bacterial meningitis is life-threatening and requires immediate antibiotic therapy. Chemical meningitis dramatically responds to steroid. The results of CSF study improved shortly after steroid administration. Key Words: Chemical meningitis; Epidural anesthesia; Spinal

Chemical Meningitis after Spinal or Epidural Anesthesia

Background: Chemical meningitis results from foreign materials causing inflammation to the meninges covering the brain and spinal cord. Cerebrospinal fluid (CSF) study of chemical meningitis mimics bacterial meningitis. Case Report: We report three cases of chemical meningitis after spinal or epidural anesthesia with mepivacaine or bupivacaine. They experienced mental change or seizure. The results of CSF study revealed increased polymorphonuclear cell count and protein level and decreased glucose concentration. Gram staining and bacterial culture of CSF were all negative. We started empirical antibiotics and corticosteroids immediately and the patients were rapidly improved. Conclusion: The chemical meningitis should be differentiated in bacterial meningitis because bacterial meningitis is life-threatening and requires immediate antibiotic therapy. Chemical meningitis dramatically responds to steroid. The results of CSF study improved shortly after steroid administration. J Neurocrit Care 2014;7(1):40-43

Effect of liraglutide administration and a calorie-restricted diet on lipoprotein profile in overweight/obese persons with prediabetes

Background and aimsTo evaluate the effects of 14 weeks of liraglutide plus modest caloric restriction on lipid/lipoprotein metabolism in overweight/obese persons with prediabetes. Methods and resultsVolunteers with prediabetes followed a calorie-restricted diet (−500 Kcal/day) plus liraglutide (n = 23) or placebo (n = 27) for 14 weeks. The groups were similar in age (58 ± 7 vs. 58 ± 8 years) and body mass index (31.9 ± 2.8 vs. 31.9 ± 3.5 kg/m2). A comprehensive lipid/lipoprotein profile was obtained before and after intervention using vertical auto profile (VAP). Weight loss was greater in the liraglutide group than in the placebo group (6.9 vs. 3.3 kg, p < 0.001), as was the fall in fasting plasma glucose concentration (9.9 mg/dL vs. 0.3 mg/dL, p < 0.001). VAP analysis revealed multiple improvements in lipid/lipoprotein metabolism in liraglutide-treated compared with placebo-treated volunteers, including decreases in concentrations of total cholesterol, low-density lipoprotein cholesterol and several of its subclasses, triglyceride, and non-high-density cholesterol. The liraglutide-treated group also had a significant shift away from small, dense low-density lipoprotein-particles, as well as decreases in apolipoprotein B concentration and ratio of apolipoprotein B/apolipoprotein A-1. There were no significant changes in the lipoprotein profile in the placebo-treated group. ConclusionTreatment with liraglutide plus modest calorie restriction led to enhanced weight loss, a decrease in fasting plasma glucose concentration, and improvement in multiple aspects of lipid/lipoprotein metabolism associated with increased cardiovascular disease (CVD) risk. The significant clinical benefit associated with liraglutide-assisted weight loss in a group at high risk for CVD – obese/overweight individuals with prediabetes – as seen in our pilot study, suggests that this approach deserves further study.

Mechanisms underlying the inhibitory effect of the feed contaminant deoxynivalenol on glucose absorption in broiler chickens

Deoxynivalenol (DON), a major contaminant of cereals and grains, is of public health concern worldwide and has been shown to reduce the electrogenic transport of glucose. However, the full effects of Fusarium mycotoxins on nutrient absorption are still not clear. The aim of this study was to investigate whether decreased nutrient absorption was due to specific effects on transporter trafficking in the intestine and whether inhibition of phosphoinositol-3-kinase (PI-3-kinase) affected the electrogenic jejunal transport of glucose.Jejunal mucosa of 6-week-old broiler chickens were mounted in Ussing chambers and treated with DON, wortmannin (a specific inhibitor of PI-3-kinase), DON + wortmannin, phlorizin and cytochalasin B. DON was found to decrease the short-circuit current (Isc) after glucose addition. A similar decline in Isc after glucose addition was observed following pre-application of wortmannin, or phlorizin (Na+/glucose co-transporter, SGLT1 inhibitor). The results indicate that DON decreased glucose absorption in the absence of wortmannin or phlorizin but had no additional effect on glucose absorption in their presence. Glucose transport was not affected by cytochalasin B (facilitative glucose transporter, GLUT2 inhibitor). The study provides evidence that the suppressive effect of DON on the electrogenic transport of glucose may be due to an inhibitory activity of the PI3 kinase pathway and intestinal SGLT1. Furthermore, the effect of cytochalasin B on glucose transport in chicken tissues differs from that in mammals.

The role of Chromium III in the organism and its possible use in diabetes and obesity treatment.

Diabetes and obesity are diseases characterized by their increasing incidence every year. When comparing with healthy subjects, the serum levels of chromium (Cr) are lowered in these two diseases. Several studies conducted in laboratory animals with experimentally- induced diabetes demonstrated that supplementation with chromium ions (III) decreased glucose concentration in the blood, reduced the probability of atherosclerosis and heart attack, lowered the levels of cholesterol and low density lipoprotein (LDL). The Importance of chromium is actually challenged due to lack of clear manifestations of Cr deficiency in humans and animals. The aim of this review was to present current knowledge about Cr its role in the organism and possible mechanisms of its action also in metabolic disorders such as diabetes or obesity. In the last decade, Cr was established to be rather a beneficial than essential trace element in mammals, and has gained popularity as a nutritional supplement and a component of many multivitamin/mineral formulations, fortified food and energy drinks. Cr supplements are widespread for diabetes and obesity treatment, despite conflicting reports on its efficacy. It was suggested that Cr shows a beneficial influence upon glucose and lipid disturbances. The recent clinical trials provided evidence both in favor and against the importance of Cr in healthy and ill organisms. Unfortunately, also the molecular mechanism by which chromium affects glucose and lipid metabolism is still unclear. Beneficial effects of diet supplementation with different sources of Cr³⁺ can be potentially explained by rather pharmacological than nutritional effects.

Synthesis of coumarin derivatives containing pyrazole and indenone rings as potent antioxidant and antihyperglycemic agents

The present work describes the synthesis of 6-substituted-3-(1-(4-substituted)-4-((Z)-(5,6-dimethoxy-1-oxo-1H-inden-2(3H)-ylidene)methyl)-1H-pyrazol-3-yl)-2H-chromen-2-one derivatives (5a–l) by Claisen–Schmidt condensation of 3-(6-substituted-2-oxo-2H-chromen-3-yl)-1-(4-substituted)-1H-pyrazole-4-carbaldehyde derivatives (4a–l) with 5,6-dimethoxy-2,3-dihydro-1H-inden-1-one at reflux temperature for 8h. The synthesized compounds were screened for in vitro antioxidant activity. Compounds 5e and 5g showed promising DPPH radical scavenging activity with IC50 54.14–56.19μg/mL, ferrous ion chelating ability with IC50 53.75–56.89μg/mL and reductive capability with IC50 58.01–62.57μg/mL. The selected compounds were also tested for in vivo antihyperglycemic activity against Streptozotocin–nicotinamide induced Adult Wistar rats. Compounds 5e and 5g showed significant decrease in glucose concentration (115 and 138mg/dL) with the dose of 100mg/kg.

New metabolic activity of the nonsulfated sulfakinin Zopat-SK-1 in the insect fat body

Insect sulfakinins are multifunctional neuropeptides homologous to vertebrate gastrin/cholecystokin (CCK) neuropeptide hormones. We investigated the action of the nonsulfated sulfakinin Zopat-SK-1 (pETSDDYGHLRFa) on the levels of chosen metabolites in the Zophobas atratus beetle fat body. Samples of fat body were collected 2h and 24h after hormone injection. The administration of 20pmol of Zopat-SK-1 to feeding larvae significantly increased concentrations of lipids and proteins and decreased the content of glycogen in fat body tissue in the 24h experimental group. In contrast, the only increase in total lipid concentration in prepupal fat bodies was observed 24h after Zopat-SK-1 treatment. Simultaneously, changes in the quality and quantity of free sugars in the hemolymph were measured. In larval hemolymph, a marked increase in free sugar concentration and a decrease in glucose content were observed 24h and 2h after Zopat-SK-1 application, respectively. No changes in the prepupal stage were observed. For the first time we show potent metabolic activity of sulfakinin in the fat body tissue of an insect. Our findings imply a physiological function of the nonsulfated form of sulfakinin in energy storage and release processes in fat body tissue of larvae and prepupae was indicated. We suggest a role for sulfakinin signaling in the regulation of energy metabolism in insect tissues.

Metformin suppresses gluconeogenesis by inhibiting mitochondrial glycerophosphate dehydrogenase.

Metformin is considered to be one of the most effective therapeutics for the treatment of type 2 diabetes (T2D) since it specifically reduces hepatic gluconeogenesis without increasing insulin secretion, inducing weight gain, or posing a risk of hypoglycemia1,2. For over half a century, this agent has been prescribed to T2D patients worldwide, yet the underlying mechanism by which metformin inhibits hepatic gluconeogenesis remains unknown. Here we show that metformin non-competitively inhibits the redox shuttle enzyme mitochondrial glycerophosphate dehydrogenase (mGPD), resulting in an altered hepatocellular redox state, reduced conversion of lactate and glycerol to glucose, and decreased hepatic gluconeogenesis. Acute and chronic low-dose metformin treatment effectively reduced endogenous glucose production (EGP), while increasing cytosolic redox and decreasing mitochondrial redox states. Antisense oligonucleotide (ASO) knockdown of hepatic mGPD in rats resulted in a phenotype akin to chronic metformin treatment, and abrogated metformin-mediated increases in cytosolic redox state, decrease in plasma glucose concentrations and inhibition of EGP. These findings were replicated in whole-body mGPD knockout mice. These results have significant implications for understanding the mechanism of metformin’s blood glucose lowering effects and provide a novel therapeutic target for T2D.

Energy metabolites, lipid variables and lactation performance of periparturient Murrah buffaloes (Bubalus bubalis) fed on diet supplemented with inorganic chromium.

The aim of this study was to elucidate the effects of chromium (Cr) supplementation as inorganic Cr (CrCl3·6H2O) on energy balance, lipid peroxidation, and lactation performance in periparturient Murrah buffaloes. Twenty-four multiparous Murrah buffaloes according to lactation, parity, body mass, and expected calving date were divided equally. Experimental buffaloes were randomly assigned to four treatment diets: a control diet and three diets with an inorganic Cr supplementation at 0.5, 1.0, and 1.5 mg of Cr/kg dry matter (DM), respectively from 60 days before expected calving date until 60 days of lactation. Milk productions of buffaloes were recorded every day until 60 days in milk. Blood samples were collected at days -60, -45, -30,-21, -15, -7, -3, 0, 7, 15, 21, 30, 45, and 60 days relative to actual calving for determination of plasma glucose, nonesterified fatty acid (NEFA), thiobarbituric acid reactive substance (TBARS), total cholesterol, total protein, albumin, blood urea nitrogen (BUN), and minerals. Adding inorganic Cr to the diet of Murrah buffaloes increased milk yield. Percentage of fat and total solid yield increased significantly through the experiment in the Cr-supplemented group. At the day of calving, buffaloes showed a decrease in dry matter intake (DMI), plasma glucose, and zinc (Zn) and Cr concentrations. In contrast, plasma NEFA, TBARS, and copper (Cu) levels were found highest at the day of calving among all groups. Cr supplementation increased peripheral blood glucose concentration while decreased level of NEFA and TBARS was recorded in Cr-fed buffaloes. Supplemental Cr had no effect on plasma cholesterol, total protein, albumin, and BUN in periparturient period. Dietary Cr supplementation had positive effect on plasma Cr concentration, but the plasma concentration of Cu, Zn, and iron (Fe) was not affected by different dietary Cr level supplementation. The results suggest that dietary inorganic Cr supplementation improved milk yield by reducing negative energy balance and lipid peroxidation in buffaloes during periparturient period.

Effect of oat intake on glycaemic control and insulin sensitivity: a meta-analysis of randomised controlled trials.

The present meta-analysis of randomised controlled trials (RCT) aimed to investigate the effect of oat intake on glycaemic control and insulin sensitivity. A literature search was carried out in PubMed, ScienceDirect Online and The Cochrane Library (up to October 2013) for RCT that assessed the effect of oat intake on glucose control and insulin sensitivity. A total of fifteen articles with 673 subjects met the inclusion criteria. A random-effects model was used when the overall pooled studies exhibited significant heterogeneity. Otherwise, a fixed-effects model was used. Compared with controls, oat intake significantly reduced the concentrations of fasting insulin by - 6·29 (95 % CI - 12·32, - 0·27) pmol/l (P= 0·04) and the values of glucose AUC (GAUC; 0-120 min) by - 30·23 (95 % CI - 43·65, - 16·81) min × mmol/l (P< 0·0001). There was a slight decrease in fasting glucose concentrations, glycated Hb concentrations and homeostatic model assessment-insulin resistance values in subjects who consumed oats, but the difference was not significant. In conclusion, oat intake significantly lowers fasting insulin concentrations and GAUC values. To further investigate the effect of oat intake on fasting glucose concentrations, additional long-term and high-quality RCT with a parallel design are required.

Glibenclamide in patients with poorly controlled type 2 diabetes: a 12-week, prospective, single-center, open-label, dose-escalation study.

BackgroundThe purpose of this study was to investigate the effect of glibenclamide dose escalation on blood glucose and insulin in patients with poorly controlled type 2 diabetes.MethodsTwenty-two subjects with type 2 diabetes were administered increasing doses (0, 2.5, 5, 10, and 20 mg/day) of glibenclamide at 2-week intervals. Glibenclamide, glucose, and insulin determinations were performed.ResultsThe decrease in mean blood glucose from zero dose was 20%, 22%, 26%, and 28% for doses of 2.5, 5, 10, and 20 mg/day, respectively, which was significant from zero dose to 2.5 mg/day (P≤0.001). There were no significant decreases in glucose concentration beyond 2.5 mg/day. The percentage increase in mean insulin from zero dose was 51%, 58%, 44%, and 33% for 2.5, 5, 10, and 20 mg/day respectively. Mean blood insulin increased significantly from zero dose to 2.5 mg/day (P≤0.001). There were no significant increases in mean insulin concentration beyond 2.5 mg/day.ConclusionThe results of this study suggest that increasing doses of glibenclamide do not produce a proportional increase in insulin secretion or a proportional decrease in blood glucose concentration.

Activation of survival signals in melanoma cells in response to glucose deprivation (766.9)

Cancer’s use of alternate cellular pathways is necessary in order to proliferate and expand so aggressively but may make it possible to target using certain cancer therapies. We studied the effects that lowered glucose concentrations have on important cancer characteristics in WM266‐4 Melanoma cells. Changes to the cells included observable effects like morphology alteration and inhibition of growth as well as modification to internal signaling pathways. The cytoskeleton, being important for its interaction with insulin containing vesicles, altering of GLUT transporter translocation and glucose metabolism related enzymes, was disrupted after 48 hours which can be seen by the cells decreasing dendricity. Inhibition of growth was found to be correlated with decreasing glucose concentrations in medium, as was depletion of nutrients and changes in pH of the extracellular environment. Reduction in pH could be a mechanism of the cancer cells to proliferate and survive, the result of heavy production of lactic acid caused by increased rate of glycolysis, or both. Levels of p‐S6, p‐AMPK, p‐ERK and p‐MEK were shown to be increased by glucose deprivation at 6 hours showing that the cancer cells are fighting back in order to survive. S6 ribosomal protein as well p‐ACC decreased with glucose deprivation at 48 hours while p‐AMPK increased showing high levels of stress and eventually cellular shutdown. Finally, GLUT1 transporter expression as well as survivin, an anti‐apoptotic molecule, was shown to be increased at 24 hours under glucose deprivation. Collectively, our data suggest that the effects of glucose deprivation on melanoma are important in understanding the way these cells uptake their nutrients and may provide for therapeutic treatments in the future.Grant Funding Source: Supported by INBRE research grant

A controlled trial on the effect of feeding dietary chestnut extract and glycerol monolaurate on liver function in newborn calves

SummaryBeginning in the fall of 2010, an increasing and alarming number of cases of calves suffering from liver dystrophy were reported in the south of Germany. An epidemiological investigation was carried out by the authors between November 2010 and July 2011, leading to the implication of a commercial dietary supplement as the potential cause for this outbreak. The components of this product were first tested in a cell culture model and two of them (dietary chestnut extract and glycerol monolaurate) showed a cytotoxic effect. The objective of this study was therefore to evaluate the effect of supplemental feeding of both components alone or in combination on liver function in newborn calves on a commercial dairy farm. Ten calves were enrolled in each of the three treatment groups and the control group (group O) following a blocked design. Treatment consisted of supplementation with chestnut extract at 0.02% of birth body mass (BM) (group C), supplementation with glycerol monolaurate at 0.006% of BM (group G) or a combined treatment (group CG) for five consecutive days. The effect of treatments on liver function was evaluated clinically and by measurement of glutamate dehydrogenase (GLDH) and aspartate aminotransferase (AST) activities as well as the determination of the concentrations of glucose, L‐lactate and total bilirubin in serum. There was a significant increase in GLDH and AST activities and a significant decrease in glucose concentration in treatment groups C and CG compared with the control group (p ≤ 0.035), whereas no difference was shown for group G. Survival was significantly decreased in groups C (p = 0.029) and CG (p = 0.001) compared with both group G and the control group. These results suggest that dietary chestnut extract in an amount of 0.02% of BM alone or in combination has a toxic effect on liver function in newborn calves.

Pro-inflammatory TNF-α in response to single bout cycling in type II diabetic patients

Accumulating evidence suggest that type II diabetes is associated with systemic inflammation. This study aimed to determine relationship between serum TNF-α with glucose and insulin resistance and to evaluate the effect of a single bout moderate exercise on TNF-α in type II diabetes patients. For this purpose, blood samples of pre and immediately post cycling test were collected in order to measuring serum TNF-α, glucose and insulin in twelve adult males with type II diabetes. Insulin resistance was assessed using the homeostasis model assessment for insulin resistance formula derived from fasting insulin and glucose levels. Student’s paired ‘t’ test was applied to compare the pre and post exercise values. Pearson correlation coefficients were used to determine the associations between TNF-α with the blood chemistry parameters. There were no correlations between serum TNF-α concentrations with glucose and insulin and insulin resistance at baseline. Exercise test led to significant increase in TNF-a (p = 0.002) and decrease in glucose concentration (p = 0.000). No significant change were found in insulin (p = 0.154) and insulin resistance at posttest when compared to pretest. Our findings indicate that acute exercise is associated with increased inflammation immediately after test and the change of serum TNF-α by exercise test is independent of glucose or insulin resistance in type II diabetes patients.

Inhibitory effects of plant latex on trehalase activity and trehalase gene expression in the red flour beetle, Tribolium castaneum (Coleoptera: Tenebrionidae)

Plant latex contains proteins and other components that defend plants against herbivorous insects. We determined the inhibitory activity of methanolic extracts of latex obtained from three species of plant: mulberry, Morus alba; jackfruit, Artocarpus heterophyllus; and weeping fig, Ficus benjamina, against trehalase in the red flour beetle, Tribolium castaneum. We also determined the changes that occurred throughout the life of the insect in the enzymatic activities of soluble and membrane-bound trehalase and the expression profiles of the genes encoding the two types of trehalase. Soluble trehalase activity was higher than membrane-bound trehalase activity in larvae and adults, whereas there was little difference in eggs, prepupae and pupae. The expression of the trehalases, TcTre-1 and TcTre-2, changed during insect development but did not coincide closely with changes in enzymatic activity, indicating that these changes did not necessarily depend on gene expression. All of three plant latices tested inhibited the activities of both the soluble and membrane-bound trehalase. At the gene expression level, these latices reduced the expression of TcTre-1 but not TcTre-2, indicating that the latices contain component(s) that selectively inhibit gene expression or at least differentially inhibit these two trehalase genes. The inhibition of trehalase activity resulted in a 140% increase in the concentration of trehalose in the beetle and a decrease in glucose concentration to 72% of the control. These findings show that the latices tested contain components that inhibit trehalase activity and TcTre-1 expression and thus, may contribute to the plants' defense against herbivorous insects.

Stability of glucose in plasma with different anticoagulants

People with hyperglycemia, especially those who are pregnant, depend on accurate blood glucose measurements for correct diagnosis of diabetes and monitoring. Glycolysis after blood draw, however, decreases glucose concentrations in blood that is collected at room temperature in the absence of a stabilizer. Cold temperatures (4°C) inhibit glycolysis; but prompt cooling and processing of each blood sample in the cold is difficult to achieve in routine clinical practice. Therefore, preservatives are used to stabilize glucose during blood collection and processing procedures that are performed at room temperature. This study examined the effect of different anticoagulants (EDTA, heparin, oxalate), with or without glycolysis inhibitors (NaF, citrate), on the stability of glucose in plasma samples - obtained from blood that was collected and stored at room temperature for up to 24 h. Venous blood was collected from 60 volunteers; each donor blood sample was divided into six tubes, each one containing a different anti-glycolysis-anticoagulant composition. Terumo VENOSAFE™ Glycemia tubes contained NaF/citrate buffer)/Na2EDTA; NaF/Na-heparin; and NaF/K2oxalate. Sarstedt tubes contained NaF/citrate; NaF/Na2EDTA; and K2EDTA. At 0, 2, 8 and 24 h, plasma was obtained for glucose measurements using the Glucose Hexokinase and Glucose Oxidase methods, and the ADVIA® 1800 Clinical Chemistry System. Both methods demonstrated minimal glycolysis by 24 h (<3.8%) for the three Terumo VENOSAFE™ Glycemia tubes, and the Sarstedt S-Monovette GlucoEXACT tube that contained NaF/citrate. Glycolysis was higher in tubes containing NaF/Na2EDTA-alone (11.7%) and K2EDTA-alone (85%). Terumo VENOSAFE™ Glycemia tubes (containing NaF/citrate buffer/Na2EDTA; NaF/Na-heparin; and NaF/K2oxalate) and the Sarstedt S-Monovette® GlucoEXACT tubes (containing NaF/citrate) are suitable for shipping venous whole blood samples to the testing laboratory within 24 h at room temperature.