Enzymatic Kit Research Articles

Cholestasis Detection Enzyme Tests, in Pregnant Women with Different Hospitalization Diagnosis

The aim of the study is the evaluation of serum Alkaline Phosphatase and Gamma-glutamyl Transferase levels in pregnant women as indicators of cholestasis. Cholestasis is defined as a decrease in bile flow due to the obstruction of it through intra/extra hepatic bile ducts. GGT enzyme was previously thought to be helpful in confirming a hepatic source of ALP however, GGT elevations lack the necessary specificity to be a useful confirmatory test for ALP. We analyzed 500 cases of pregnant women from year 2011-2013. Serum enzyme levels (ALP and GGT) were measured respectively using Beckman Synchron LX 20 and Enzymatic method Activity Colorimetric Kit, at the Medical Laboratory “PhD. Stelijan Buzo” in Tirana. According to the laboratory reference values of ALP (100-290 U/L): 50% of the cases resulted normally pregnant women, 50% suffering from liver disease (<100 U/L or >290 U/L); whereas according to values of GGT (8-31 U/L): 75% resulted normally pregnant women, 25% with liver damage (<8 U/L or >31 U/L). Micronutrients deficiency leads to irreversible disorders of development; Nutritional advice would have been more effective either for the mother and the future of her child. There are few reported cases of young mothers, with sufficient income, which limit some foods due to fear of increasing body weight, while forgetting that the lack of appropriate micro-nutrients, directly affects the health of growing babies.

Decoloration of wine and subsequent enzymatic quantification of histamine

We would like to present a simple decoloration procedure for (red) wine and the subsequent enzymatic method for the specific quantification of histamine. The test kit for sample preparation contains three solutions that are used to decolorate wine by two simple precipitation steps within 15 min. The enzymatic test kit consists of a microtiter plate coated with two substrates and ready to use reagents (buffer, calibrators and enzyme histamine dehydrogenase). The determination is performed within 15 min and the measurement wavelength is 450 nm which is the common wavelength for ELISA procedures. The linear range is from 1 to 20 mg/L in the extracted sample (corresponding to 2.4–48 mg/L in wine) and the recovery is >85% in red wines and more than 90% in white and rose wines. The limit of quantification is calculated to 1 mg/L. Wines at this low histamine levels showed CVs of less than 7%. The assay shows a high precision with a relative within-lab reproducibility standard deviation of less than 7%. A method comparison between HPLC and the new enzymatic system revealed a very high degree of agreement. The enzymatic procedure contains no dilution steps, no washing steps like for an ELISA, and a clear defined end-point of the enzymatic reaction.

Oxidative stress and plasma lipoproteins in cancer patients.

Objective To evaluate the relation between oxidative stress and lipid profile in patients with different types of cancer.Methods This was an observational cross-sectional. A total of 58 subjects were evaluated, 33 males, divided into two groups of 29 patients each: Group 1, patients with cancer of the digestive tract and accessory organs; Group 2 patients with other types of cancers, all admitted to a public hospital. The plasma levels (lipoproteins and total cholesterol, HDL, and triglycerides, for example) were analyzed by enzymatic kits, and oxidative stress based on thiobarbituric acid-reactive substances, by assessing the formation of malondialdehyde.Results In general the levels of malondialdehyde of patients were high (5.00μM) as compared to 3.31μM for healthy individuals. The median values of lipids exhibited normal triacylglycerol (138.78±89.88mg/dL), desirable total cholesterol values (163.04±172.38mg/dL), borderline high LDL (151.30±178.25mg/dL) and low HDL (31.70±22.74mg/dL). Median HDL levels in Group 1 were lower (31.32mg/dL) than the cancer patients in Group 2 (43.67mg/dL) (p=0.038). Group 1 also showed higher levels of oxidative stress (p=0.027).Conclusion The lipid profile of patients with cancer was not favorable, which seems to have contributed to higher lipid peroxidation rate, generating a significant oxidative stress.

Characterization of potentially probiotic lactic acid bacteria isolated from olives: Evaluation of short chain fatty acids production and analysis of the extracellular proteome

Probiotic strains can exert positive effects on human health by various mechanisms, among which the production of short chain fatty acids (SCFA). All the SCFA, mainly acetic, propionic and butyric acid, display beneficial effects on human health; butyric acid is the most interesting for its role in the prevention and treatment of colonic diseases.In this study the ability of 17 potentially probiotic food-isolated lactic acid bacteria to produce SCFA, directly or indirectly through the production of lactic acid, was investigated. Propionic and butyric acids were quantified by gas chromatography; acetic and lactic acids were quantified by specific enzymatic kits. All the tested strains displayed the ability to produce significant amounts of acetic and lactic acids (in the range of g/L) and just small amounts of propionic and butyric acids (in the range of mg/L).The extracellular proteomes of two of these strains, Lactobacillus plantarum S11T3E and Lactobacillus pentosus S3T60C, were evaluated by coupling 2-DE and MALDI TOF-TOF mass spectrometry. This is an interesting approach to investigate a probiotic strain, since secreted proteins represent the first contact point between bacteria and the host after ingestion. Six and seven proteins, in different isoforms, were identified from L. pentosus S3T60C and L. plantarum S11T3E, respectively. All of them have a predicted extracellular location, indicating the effectiveness of the used protocol. L. plantarum S11T3E secretes several proteins with adhesive function, suggesting that in this strain the ability to adhere to gut mucosa depends on this kind of molecules. In L. pentosus S3T60C just one adhesive protein is secreted suggesting that other families of molecules play a role in its adhesive ability.

Lycium barbarum polysaccharides protect human lens epithelial cells against oxidative stress-induced apoptosis and senescence.

ObjectivesWe aimed to investigate the protective effect of Lycium barbarum polysaccharides (LBPs) against oxidative stress–induced apoptosis and senescence in human lens epithelial cells.MethodsTo study apoptosis, SRA01/04 cells, a human lens epithelial cell lines, were exposed to 200 µM hydrogen peroxide (H2O2) for 24 h with or without pretreatment with LBPs. Cell viability was measured using a Cell Counting Kit-8 (CCK-8) assay. Cell apoptosis, intracellular reactive oxygen species (ROS), and the loss of mitochondria membrane potential (Δψm) were detected by flow cytometric analyses. Expression levels of Bcl-2 and Bax proteins were measured by western blot analysis. The levels of malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH) were quantized using commercial enzymatic kits according to the manufacturer's instructions. To study senescence, SRA01/04 cells were pre-incubated with LBPs and all cells were then exposed to 100 µM H2O2 for 96 h. Cellular senescence was assessed by morphologic examination and senescence-associated β-galactosidase (SA-β-gal) staining.ResultsLBPs significantly reduced H2O2-induced cell apoptosis, the generation of ROS, the loss of Δψm, and the levels of MDA. LBPs also inhibited H2O2-induced downregulated Bcl-2 and upregulated Bax proteins and increased the levels of SOD and GSH enzyme activity. Moreover, LBPs significantly attenuated H2O2-induced cellular senescence.ConclusionsThese findings suggested that LBPs protect human lens epithelial cells from H2O2-induced apoptosis by modulating the generation of ROS, loss of Δψm, Bcl-2 family, and antioxidant enzyme activity and attenuating cellular senescence.

&lt;i&gt;Olea europaea&lt;/i&gt; Linn (Oleaceae) Fruit Pulp Extract Suppresses Sterol Regulatory Element-Binding Proteins-1c via AMP-Activated Protein Kinase Activation in Human Hepatic Cells

Purpose: To investigate the molecular mechanisms underlying the role of Olea europaea Linn (Oleaceae) fruit pulp extract (OPF) in the prevention of high glucose-induced lipid accumulation in human HepG2 hepatocytes.Methods: HepG2 cells were pretreated with various concentration of OPF (0, 10, 20, 40 and 80 µg/ml) and then treated with serum-free medium with normal glucose (5 mM) for 1 h, followed by exposure to high glucose (25 mM D-glucose) for 24 h. Cell viability and cytotoxicity parameters were measured using LDH and MTT assay while triglyceride and total cholesterol levels were evaluated using respective enzymatic reagent kits. Protein expressional levels were analyzed by Western blotting.Results: OPF did not influence the cell viability (up to 200 µg/ml) and showed any signs of cytotoxicity (up to 80 µg/ml). OPF significantly attenuated lipid accumulation in human HepG2 hepatocytes whenexposed to high glucose (25 mM D-glucose) in a dose-dependently (p &lt; 0.05, 0.01 and 0.001 at 20, 40 and 80 µg/ml concentrations, respectively). Nile red staining showed that 10, 20, 40 and 80 µg/ml concentrations of OPF reduced lipid accumulation by 25, 33.7 (p&lt; 0.05), 43.7 (p attenuated by OPF (p &lt; 0.001 at 80 µg/ml). Further, OPF attenuated the expression of fatty acid synthase and sterol regulatory element-binding protein-1. Adenosine monophosphate-activated protein kinase was also activated by OPF treatment when exposed to high glucose (25 mM D-glucose) inhuman HepG2 hepatocytes.Conclusion: This study indicates that OPF has hypolipidemic effects by inhibiting lipid biosynthesis mediated via AMPK signaling. Thus, this extract can be potentially developed into an anti-obesity agent.Keywords: Olea europaea, Fruit pulp extract, Lipogenesis, AMPK SREBP-1, Anti-obesity; HepG2 cells

Serum lipid concentrations in patients with cholesterol and pigment gallstones.

BackgroundGallstones (GS) are formed as a result of impaired metabolic regulation of the human body. Abnormal lipid metabolism is partly responsible for the pathogenesis of GS mainly rich in cholesterol. Thus abnormalities of serum lipids would reflect the possibilities of the formation of cholesterol GS. This study aims to identify the significance of serum lipids on the development of GS disease.MethodsSerum lipid profiles were estimated in 73 patients with symptomatic GS, admitted to the Teaching Hospital, Peradeniya, Sri Lanka for GS removal surgeries from May 2011 to December 2012. Patients with normal serum bilirubin level and not being on lipid lowering drugs were recruited for the study. Serum lipid profile of each patient was analyzed by enzymatic kit assays and the chemical composition of GS was analyzed by Fourier Transform Infrared spectroscopy.ResultsOf the 73 patients, 37 (51%) had cholesterol GS while 36 (49%) had pigment GS. Serum lipid parameters of a majority of patients were within the normal range. Body mass index values of the patients with two types of GS were not significantly different (Two sample t test, p = 0.335). Out of the lipid parameters tested, only serum triglyceride concentration was significantly high in patients with cholesterol GS than that of pigment GS (Two sample t test, p = 0.038). None of the lipid parameters were significantly different between males and females (Two sample t test, p > 0.05). Compared to the patients with pigment GS who were aged below 50 years, mean total cholesterol and triglyceride concentrations were higher in the same age category patients with cholesterol GS.ConclusionAbnormal serum lipid profiles doesn’t seem to be an essential feature in patients with cholesterol GS. However when the two groups of patients with cholesterol and pigment GS with no significant difference of body mass indexes were compared, patients with cholesterol GS are more likely to have serum lipid parameters towards the undesirable cutoff levels of their respective normal ranges. However an effect of serum lipid concentrations on high incidence of GS among females has not been identified.

Effect of Yizhitongxuan decoction on learning and memory ability, Gαq/11 expression and Na+−K+-ATP enzyme activity in rat models of Alzheimer's Disease

ObjectiveTo study the effects of Yizhitongxuan decoction on learning and memory abilities, Gαq/11 expression and Na+−K+−ATP enzyme activity in rat models of Alzheimer's disease (AD) caused by injecting Aβ25-35 into the hippocampus. MethodsNinety male Wistar rats (age ≤10 months) were selected and injected with Aβ25-35 into their hippocampi to establish model animals, which were randomly divided into six groups including a sham-operated group (blank group), a model group, a donepezil HCL group (Western Medicine group), and a high/general/dilute concentrations of Yizhitongxuan decoction groups (TCM I II III group). The Morris water maze was used to examine the learning and memory abilities of rats in each group by place navigation and spatial probe tests. Then, the rats were sacrificed to collect the hippocampi for biochemical tests, using western blotting to detect the expression of Gαq/11 and an ultramicro Na +−K+−ATP enzyme kit to measure Na+−K+−ATP enzyme activity. ResultsYizhitongxuan decoction improved model rats' learning and memory abilities, and increased the expression of Gαq/11 in the hippocampus and the level of Na+−K+−ATP enzyme activity in brain tissue. ConclusionsYizhitongxuan decoction could improve model rats' learning and memory abilities, and had a regulating effect on the expression of Gαq/11 and Na+−K+−ATP enzyme activity.

Body fat and plasma lipid profile in different levels of physical fitness in male students.

Adiposity is correlated with metabolic complications, such as insulin resistance, glucose intolerance, hypertension etc. that finally can lead to coronary heart disease (CHD). Physical activity plays an important role in prevention of these diseases. We aimed to study body fat and plasma lipids and lipoproteins in different levels of physical fitness; also to examine any relationship between body fat and level of physical fitness. In this cross-sectional study carried out in Hamadan University of Medical Sciences (Hamadan, Iran) during 2010-2011, 80 healthy volunteer male students (19-27 yr old) were enrolled. The subjects were divided to three groups i.e. good, average and weak according to their physical fitness scores. Their lipid profile was determined using an auto-analyzer and commercial enzymatic spectorophptometric kits. Besides, body fat was determined using skinfold technique. The fitness tests were carried out for all participants, including: speed, stamina, aerobic endurance, muscular strength etc. The mean of body fat (%) in the subjects with good, medium and weak levels of physical activity was 8.25, 11.98, and 22.65 % respectively. There were no significant differences in lipid parameters between the subjects with different level of physical fitness. A negative significant correlation was observed between physical fitness and body fat (r=-0.27, P=0.034). The body fat increased with increases in serum triglyceride. The presence of difference in mean of body fat percent in different physical fitness confirms that aerobic activity improves the plasma lipid and lipoprotein profile, and can diminish the body fat.

A Pilot Study on Vitamin-D Status and Metabolic Syndrome in Adult Indian Population

Vitamin D status indicated by 25-hydroxyvitamin D, along with its classic role in calcium homeostasis and bone metabolism, is thought to be inversely associated with adiposity, glucose homeostasis, lipid profiles, and blood pressure. Studies among the western population have also shown it to be inversely associated with metabolic syndrome (MS) and cardiovascular diseases (CVDs). However, evidence from the Asian population is limited. Therefore, the present study aimed to study the prevalence of vitamin D deficiency (VDD) (&lt;20 ng/mL) and its association with metabolic risk factors among adults. About 129 adults in the age group 30-60 years, who gave consent for participation, were enrolled in the study through snowball effect. Anthropometric measurements were recorded using standard methods &amp; tools. Serum 25(OH)D was estimated by CLIA method, lipid profile and fasting-glucose using enzymatic kits. MS was defined using NCEP ATP-III, 2005 guidelines. The results revealed that, around 88% of the subjects had VDD, with the prevalence being significantly higher among females than males (95% vs 77%). 31% of the population had MS of which 87.5% were vitamin-D deficient. The vitamin-D status of the subjects was not significantly related with the risk of developing MS (OR=0.88, 95% CI= 0.28-2.78). None of the risk factors for MS correlated significantly with the vitamin-D levels of the subjects. Waist-circumference (Exp(B)= 0.281, 95% CI= 0.089-0.887) entered the model for logistic regression with vitamin-D status as the dependent variable. Thus the results highlighted the high prevalence of VDD among the population and it was independently associated with greater abdominal obesity.DOI: http://dx.doi.org/10.3126/ijasbt.v2i2.10180Int J Appl Sci Biotechnol, Vol. 2(2): 126-131

Rapid Determination of Sucrose in Fruit Juices: A New Sensitive Carbon Nanotube Paste Osmium-Polymer Mediated Biosensor

&lt;p&gt;The aim of the present work was the development of a novel amperometric biosensor for rapid detection of sucrose in fruit juices samples. Two enzymes, invertase and fructose dehydrogenase (FDH), were immobilized onto a single-walled carbon nanotube paste (SWCNTP) electrode by wiring with a highly original osmium-polymer hydrogel. A second biosensor, for fructose only, was constructed containing inactive invertase and used for signal subtraction.&lt;/p&gt; &lt;p&gt;The biosensor exhibits a detection limit for sucrose of 2 mM, linearity up to 5 mM, good sensitivity of 1.98 mA cm&lt;sup&gt;-2&lt;/sup&gt; mM, good reproducibility (RSD = 2.5%), fast response time (8s) and a stability of 4 months if kept under wet conditions at 4 °C.&lt;/p&gt; &lt;p&gt;The biosensor was successively tested for specific detection of sucrose and fructose in several commercial fruit juice samples and the results were compared with those obtained with a commercial spectrophotometric enzymatic kit.&lt;/p&gt;

Abstract 627: A Deleterious Mutation in SCARB1 Significantly Alters High-Density Lipoprotein Level, Composition and Biological Function in Humans

The membrane protein Scavenger Receptor Class B, Type 1 (SR-BI), coded by the gene SCARB1, facilitates the selective uptake of cholesteryl esters from HDL in the liver. Its impact on human lipoprotein metabolism however is not fully understood. Our laboratory has recently identified two homozygotes and 16 heterozygotes for a coding mutation in SCARB1 (c.1127C&gt;T, p.Pro376Leu). We assessed the hypothesis that this SCARB1 mutation significantly increases HDL-C and alters HDL composition and biological function. Plasma from subjects homozygous (n=2) or heterozygous (n=8) for the SR-BI Pro376Leu mutation was compared with that of normolipidemic controls. Five major HDL subfractions were isolated from EDTA-treated plasma using isopycnic density gradient ultracentrifugation and their chemical composition was assayed using commercial enzymatic assay kits. Quantification of &gt;160 molecular species of HDL phospho- and sphingolipids was accomplished via a novel LC-ESI/MS/MS based analysis. Cholesterol efflux capacity, measured from THP-1 macrophages, was determined in total HDL. We identified a &gt;2-fold increase in HDL-C in homozygotes and a &gt;1.5-fold increase in heterozygotes compared to controls, owing mainly to an increase in large, light HDL2 particles. The ApoA-I/ApoA-II ratio was increased in a gene-dose dependent fashion. HDL isolated from heterozygotes mediated 13.5% less efflux when compared to particles from control subjects. Analysis of the HDL phosphosphingolipidome revealed a 23% decrease in phosphatidylinositol content between carriers and controls. A gene-dose dependent trend towards diminishment of phosphatidylserine and increased ceramide was noticeable. In conclusion, the SR-BI Pro376Leu significantly increases HDL levels, but potentially reduces the capacity of HDL to mediate cellular cholesterol efflux. This may be due in part to a decrease in minor, negatively charged phospholipid subclasses including PI and PS, which have previously been shown to play a functional role in stimulating cellular cholesterol efflux.

Abstract 414: In Hyperalphalipoproteinemic Subjects, the Presence of Coronary Artery Disease is Associated With Marked Changes in the High-Density Lipoprotein Phosphosphingolipidome

Plasma concentrations of HDL-C have long been shown to correlate inversely with risk of coronary artery disease (CAD), however the causal nature of this association has not been established. Here we examine the chemical composition and phosphoshingolipidome of HDL in a cohort of subjects with premature CAD, despite having HDL levels ≥90th percentile. We hypothesized that HDL from hyperalphalipoproteinemic subjects with CAD would have distinct compositional changes compared to healthy hyperalphalipoproteinemic subjects, which may relate a reduction in HDL functionality and a pro-atherogenic state. Subjects with HDL ≥90th percentile and CAD (HHDL+CAD, n=25) were compared to healthy subjects with HDL ≥90th percentile (HHDL, n=23). A group of healthy controls with HDL between the 25th and 75th percentile (n=11) was used as reference. HDL subfractions were isolated from EDTA plasma using isopycnic density gradient ultracentrifugation and their chemical composition was assayed using commercial enzymatic assay kits. Quantification of &gt;160 molecular species of total HDL phospho- and sphingolipids was accomplished via a novel method using LC-ESI/MS/MS analysis. The most striking differences were observed in total HDL phospho- and sphingolipid subclasses between groups. When expressed as a percentage of total phosphosphingolipid, phosphatidylcholine (PC) and phosphatidylinositol (PI) were depleted in HHDL+CAD group compared to HHDL, while sphingomyelin (SM) was increased, resulting in a lower PC/SM ratio. The HDL PC/SM ratio has previously been shown to correlate with HDL surface fluidity and antioxidative activity. Additionally, enrichment of PI, a minor, negatively charged phospholipid, has been shown to stimulate cholesterol efflux to reconstituted HDL. Reduction in these two metrics, observed in the HHDL+CAD group, may indicate functionally deficient HDL and may represent pro-atherogenic, HDL-associated biomarkers of CAD in hyperalphalipoproteinemia.

Homeobox Transcription Factor VentX Regulates Differentiation and Maturation of Human Dendritic Cells

Dendritic cells (DCs) are specialized antigen presentation cells that play critical roles in the initiation and regulation of immune responses. The molecular determinants of DC differentiation and maturation are target of extensive investigation. VentX is a human homeobox transcriptional factor that regulates proliferation and differentiation of hematopoietic cells. In the current study, we report that ablation of VentX expression in monocytes significantly impaired their differentiation into DCs. Conversely, overexpression of VentX in monocytic THP1 cells accelerated their differentiation toward DCs. We showed that VentX regulates DC differentiation, in part, through modulating IL6 expression. Clinically, we found that VentX expression was elevated in intestinal lamina propria DCs (LPDCs) of inflamed mucosa from inflammatory bowel disease patients. Knockdown experiments suggested that VentX is essential for the maturation of LPDCs. In addition, corticosteroid treatment markedly decreased VentX expression in LPDCs and enforced expression of VentX counteracted the effects of corticosteroid on DCs maturation. Our data suggest that VentX is a critical transcriptional regulator of DC differentiation and maturation, and a potential target of immune regulation and therapy.

Lipotoxic effect of p21 on free fatty acid-induced steatosis in L02 cells.

Nonalcoholic fatty liver disease (NAFLD) is increasingly regarded as a hepatic manifestation of metabolic syndrome. Though with high prevalence, the mechanism is poorly understood. This study aimed to investigate the effects of p21 on free fatty acid (FFA)-induced steatosis in L02 cells. We therefore analyzed the L02 cells with MG132 and siRNA treatment for different expression of p21 related to lipid accumulation and lipotoxicity. Cellular total lipid was stained by Oil Red O, while triglyceride content, cytotoxicity assays, lipid peroxidation markers and anti-oxidation levels were measured by enzymatic kits. Treatment with 1 mM FFA for 48 hr induced magnificent intracellular lipid accumulation and increased oxidative stress in p21 overload L02 cells compared to that in p21 knockdown L02 cells. By increasing oxidative stress and peroxidation, p21 accelerates FFA-induced lipotoxic effect in L02 cells and might provide information about potentially new targets for drug development and treatments of NAFLD.

Simultaneous analysis of urinary fructose and sucrose by isotope dilution tandem LCMS (959.14)

Objective: Sugar intake has increased vastly in the US diet during past decades and has been associated with obesity, metabolic syndrome, type 2 diabetes, cardiovascular disease, and cancer. Measuring sugar intake by FFQ is not reliable and urinary fructose and sucrose excretion as a biomarker is recommended but existing methods for their analysis are complex, expensive or unreliable (GCMS, enzymatic kits, doubly labeled water). A simple liquid chromatography mass spectrometry (LCMS) method was therefore established for urinary fructose and sucrose.Methods: This study evaluated many extraction, chemical derivatization and electrospray ionization (ESI) tandem MS variations in positive and negative mode using isotope dilution and reversed, normal or reversed reversed phase LC protocols.Results: While sucrose was measurable reliably by many LCMS protocols myriads of interferences with fructose measurements could be avoided by derivatization of fructose to its dansyl hydrazone or by selective application of organic solvents during urine extraction.Conclusions: A reliable, simple, fast and inexpensive isotope dilution tandem ESI LCMS assay for fructose and sucrose was established requiring 20 uL or less of urine.Grant Funding Source: This research was supported by National Cancer Institute grants P30 CA71789.

Evaluation of Three Handheld Lactate Meters for Measuring Hemolymph L-Lactate in Decapod Crustaceans

The aim of this study was to determine the reliability and accuracy of 3 commercially available handheld lactate meters when measuring hemolymph L-lactate in decapod crustaceans. The instruments tested were Accutrend Plus (AP), Lactate Scout (LS), and Lactate Plus (LP), and all models were tested in triplicate and compared with a commonly used enzymatic kit for L-lactate quantification (TB-kit). The Norway lobster Nephrops norwegicus and the European lobster Hommarus gammarus were used as model organisms, with emersion as an invoker of hemolymph L-lactate. Between-method comparisons were investigated by determining correlations (Pearson's r) and concordance (concordance correlation coefficient (CCC) and Bland-Altmand's 95% limit of agreement (95% LOA)) between handheld instruments and TB-kit. Within-instrument variation was tested by calculating the coefficient of variation (CV), and the average absolute deviation from the mean (AD). The within-instrument variation was low for all models (CV, 3.8–6.1%; AD, <0.3 mM), showing high reproducibility of technical replicates. A significant correlation with TB-kit was found for all handheld instruments (AP, r = 0.970; LS, r =; 0.956; LP, r = 0.950). For both AP and LS, there was a moderate and significant concordance with TB-kit (AP, CCC = 0.945; LS, CCC = 0.940). The mean difference from TB-kit was -1.42 mM (95% LOA,-4.50–1.66 mM) for AP and 1.19 mM (95% LOA,-3.13–5.51 mM) for LP. Emersion experiments with the European lobster showed that AP and LS were in line with TB-kit in terms of detecting differences in L-lactate levels between groups of animals. As a result of the high frequency of error readings from LP, this instrument was not considered reliable when measuring L-lactate in decapod crustaceans. In conclusion the handheld instruments AP and LS are found to be reliable instruments when measuring hemolymph L-lactate in decapod crustaceans. Comparison of results from different methods should be avoided, and in cases when accurate absolute measurement of L-lactate is needed, methods allowing for greater accuracy and resolution should be used.

New Enzyme Kit Available Now from Johnson Matthey

RETURN TO ISSUEPREVAdvertisementNEXTNew Enzyme Kit Available Now from Johnson MattheyCite this: Chem. Eng. News 2014, 92, 9, 6Publication Date (Print):March 3, 2014Publication History Published online31 March 2015Published inissue 3 March 2014https://doi.org/10.1021/cen-09209-ad04Copyright © 2014 Chemical & Engineering NewsArticle Views65Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (451 KB) SUBJECTS:Peptides and proteins Get e-Alerts

Therapeutic potential of traditionally used medicinal plant Andrographis paniculata (Burm. F.) against diabesity: An experimental study in rats

ABSTRACT Metabolic effects of ten daily doses of standardized extract of Andrographis paniculata leaves (AP) rich in andrographolide were evaluated in a rat model of type-2 diabetes and in diet induced obese rats. AP was administered per-orally as suspension in 0.3% carboxymethylcellulose at doses of 50, 100 and 200 mg/kg/day for 10 consecutive days. Blood glucose, insulin and lipid profile of rats were measured by using enzyme kits. In addition, effects of such treatments on anti-oxidant enzymes activity and histopathological changes in various organs of diabetic rats were assessed. AP treatments reversed body weight losses and increased plasma insulin level in diabetic rats. The anti-oxidant enzymes activity became normal and histopathological changes observed in pancreas, liver, kidney and spleen of diabetic animals were less severe in extract treated groups. On the other hand, hyperinsulinemia and increased body weight gains observed in high fat or fructose fed rats were less severe in the extract treated groups. These observations revealed therapeutic potentials of the extract for treatments of diabesity associated metabolic disorders, and suggest that the effects of the extract on insulin homeostasis depend on the metabolic status of animals. Activation of cytoprotective mechanisms could be involved in its mode of action.

Technical note: Optimization of lactose quantification based on coupled enzymatic reactions

A colorimetric microplate-adapted lactose assay was developed to quantify lactose in dairy products. The assay was based on the coupled enzymatic reaction of β-galactosidase-glucose oxidase-horseradish peroxidase using Amplex red as detection probe. The assay showed good linearity in the range of 0.1 to 0.5mmol of lactose/L, with a limit of detection of 0.0433mmol/L and a limit of quantification of 0.1313mmol/L. The lactose assay at optimized conditions (5 U of β-galactosidase/mL, 5 U of glucose oxidase/mL, 1 U of horseradish peroxidase/mL, and 100μmol of Amplex red/L for 1h at 37°C in the dark) showed good correlation with a commercial lactose enzymatic kit with intraassay variation below 10% and interassay variations below 7.6%. The developed lactose microplate assay can be adopted as routine analysis for lactose determination in dairy products due to its relatively low cost compared with a commercial kit, relatively short reaction time, and high sensitivity and reproducibility.