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Immunocytochemical Detection Systems
Published in Lars-Inge Larsson, Immunocytochemistry: Theory and Practice, 2020
Glucose oxidase is an enzyme used far less for immunocytochemistry and sometimes accused of low sensitivity.159 Glucose oxidase activity can be detected by formazan precipitation.43,335 Alternatively, the H2O2 generated by its action on glucose can be detected by a coupled peroxidase procedure.177,179 Glucose oxidase-antiglucose oxidase (GAG) complexes have been prepared and used similarly to PAP complexes.50,99,165 In the recent application described by Kuhlmann and Peschke, various combinations of peroxidase and glucose oxidase-labeled second antibodies (or biotin-streptavidin systems) were used.179 The staining was revealed by reaction in a glucose-DAB medium. As H2O2 was created by glucose oxidase action on glucose, this peroxidase substrate was formed in the vicinity of the peroxidase-labeled antibodies. Kuhlmann and Peschke concluded that this coupled immunoenzyme procedure could be superior to conventional peroxidase cytochemistry in tissues rich in endogenous peroxidase, circumventing, as it did, addition of H2O2 to the developing medium.179
Relation Between Contraction and Metabolic Efficiency
Published in Samuel Sideman, Rafael Beyar, Analysis and Simulation of the Cardiac System — Ischemia, 2020
Joseph Kedem, M. Scheinowitz, E. Furman, J. Sonn, H. R. Weiss
Glucose concentrations were determined (in duplicate) with the aid of a kit from Sigma® using Technical Bulletin No. 510. Glucose oxidase reacting with glucose forms gluconic acid and hydrogen peroxide. Peroxidase catalyzes the oxidation of colorless Q-dianisidine by hydrogen peroxide. Oxidized O-dianisidine absorbs light at 425 to 475 nm. The intensity of the absorption is proportional to the glucose concentration. Lactic and pyruvic acids were also measured (in duplicate) using a Sigma® kit employing the enzyme lactic dehydrogenase and NADH/NAD oxidation-reduction, according to Technical Bulletins No. 726-UV and No. 826-UV. NADH absorbance is measured at 340 nm and 10 ml of blood sufficed for all the above-mentioned substrate analyses.
Anti-diabetic and Cytotoxicity Studies of Ethanol Extract of Mundulea sericea
Published in Parimelazhagan Thangaraj, Phytomedicine, 2020
S. Gangadevi, K. Kalimuthu, P. Viswanathan
One milliliter of a starch substrate (2% w/v maltose or sucrose) with a 0.2 M Tris buffer pH 8.0 and various concentrations of an MSBE extract were incubated for 5 minutes at 37°C (Apostolidis et al. 2007). The reaction was initiated by adding 1 mL of an α-glucosidase enzyme (1 U/mL), followed by incubation for 10 minutes at 37°C. Then, the reaction mixture was heated for 2 minutes in a boiling water bath to stop the reaction. The amount of liberated glucose was measured by the glucose oxidase peroxidase method.
High level of complement factor Ba within first prenatal test of gestation increases the risk of subsequent gestational diabetes: a propensity score-matched study
Published in Gynecological Endocrinology, 2022
Ying Shen, Junxian Li, Hairong Tian, Ye Ji, Ziyun Li, Junxi Lu, Huijuan Lu, Bo Liu, Fang Liu
Hemoglobin (Hb) and mean corpuscular volume (MCV) were obtained by automatic blood cell analyzer. Glycosylated hemoglobin A1c (HbA1c) was detected by high performance liquid chromatography (HPLC). Other indicators used to evaluate liver and kidney function, such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), γ-glutamyltransferase (γ-GT), blood urea nitrogen (BUN), creatinine (Cr), uric acid (UA) and blood lipids including total cholesterol (TC), triglycerides (TG), low density lipoprotein cholesterol (LDL-C) were all measured by enzymatic method. Blood glucose was measured by glucose oxidase method. The frozen (−80 °C) serum was quickly thawed in a 37 °C water bath, and then transferred to ice. Serum CFBa concentrations were measured in duplicate using a MicroVue Ba Enzyme Immunoassay Kit (Quidel Corporation, USA, A033). The detectable quantitation range was 0.033–3.239 ng/ml. The intra-assay and inter-assay coefficients of variation (CV) were 2.3% and 8.1%, respectively. The control values were in the control range.
Effects of titanium dioxide nanoparticles on nutrient absorption and metabolism in rats: distinguishing the susceptibility of amino acids, metal elements, and glucose
Published in Nanotoxicology, 2020
Yanjun Gao, Yixuan Ye, Jing Wang, Hao Zhang, Yao Wu, Yihui Wang, Lailai Yan, Yongliang Zhang, Shumin Duan, Lizhi Lv, Yun Wang
Frozen serum samples (each group with five rats) were removed and thawed, then serum glucose concentrations were determined using the glucose oxidase method according the published method (Du et al. 2014). Five microliters of serum from SD rats were placed into the working solution supplied with the glucose oxidase kit (Applygen Company, Beijing, China) and analyzed according to the manufacturer’s instructions. In this method, glucose was oxidized to gluconic acid and hydrogen peroxide (H2O2) in the presence of glucose oxidase. H2O2 further reacted with 4-aminoantipyrine by the catalytic action of peroxidase to form a red-colored quinoneimine dye complex, which was spectrophotometrically quantified using a microtiter plate reader (Bio-Rad Laboratories, Hercules, US). The detection limit of this kit was 5–10 μmol/L.
Enzyme therapy: a forerunner in catalyzing a healthy society?
Published in Expert Opinion on Biological Therapy, 2020
Saptashwa Datta, K Narayanan Rajnish, C George Priya Doss, S. Melvin Samuel, E. Selvarajan, Hatem Zayed
The main problem with most current cancer treatment methods is the lack of specificity of the treatments. The available treatments not only destroy cancer cells but also destroy the healthy cells surrounding the tumor, which leads to many complications. However, with recent advancements, one of the major new treatments involves the use of enzymes. Enzyme therapy in cancer has been applied in two different ways. In the first approach, a prodrug bound to an enzyme is directed to a specified site, and the enzyme is released only when the localized region is reached; there, the prodrug is converted into an active drug that then induces cell apoptosis. This method is known as enzyme prodrug therapy. The other approach is called antibody-mediated enzyme prodrug therapy (ADEPT). In this procedure, an enzyme is tagged to a partial or whole antibody that is specific to a tumor antigen. This results in catalysis of certain reactions inside the cell that lead to cell apoptosis. The toxic enzymes include oxidases, such as glucose oxidase, that can catalyze the formation of peroxide from glucose. However, the complexity of the system, the pharmacokinetics of the drug and enzyme and the characterization and availability of antigens are major drawbacks for these systems [106].