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Antihyperglycemic effect and mechanisms of soy isoflavones in streptozotocin-induced diabetic rats
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ABSTRACTS / Clinical Biochemistry 41 (2008) 1263–1287
3 min, then from 3.0 to 7.4 min the methanol gradient was increased from 74 to 77% methanol. From 7.4 to 9.0 min the column was cleaned with 100% methanol. Chromatographic running time was 9.0 min and calibration curves were linear from 0.1 to 2.0 ng/mL for C13-T4 and 5 to 150 ng/mL for C12-T4. The lower limit of quantification (LLOQ) was 0.01 ng/mL for C13-T4 and 5.0 ng/mL for C12-T4. Results and discussion: This method demonstrates excellent specificity, accuracy and precision (CVs of 4.1–6.2 at 2.6– 11.9 μg/dL C12-T4 and 9.2% at 2.0 ng/mL C13-T4). Administration of 100 μg of C13-T4 to a normal control gave concentrations of C13-T4 (ng/mL) and C12-T4 (μg/dL) at t = 0, 3.6 and 18 h of 0.00, 6.9; 0.99, 7.4 and 0.7, 7.5 respectively. Conclusions: The method is simple, specific and precise and allows C13- and C12-T4 to be simultaneously quantified. doi:10.1016/j.clinbiochem.2008.08.045
150 Antihyperglycemic effect and mechanisms of soy isoflavones in streptozotocin-induced diabetic rats Meng Q.H.1, Lu M.P.1, Wang R2, Song X1, Chibbar R.1, Wang X.3, Wu L.3 1,3 University of Saskatchewan, Saskatoon, SK, Canada 2 Lakehead University, Canada Objective: Incorporating soy isoflavones in the diet leads to beneficial effects on diabetes, but the metabolic changes and mechanisms underlying the improvement are incompletely understood. In this study, we fed varying amounts of soy isoflavones to streptozotocin (STZ)-induced diabetic rats and documented the resulting beneficial effects and associated metabolic changes. Methods: Diabetic rats were randomly divided into 3 groups and fed a special diet supplemented with either casein (control), low-isoflavone soy protein (LIS), or high-isoflavone soy protein (HIS) for 8 weeks, respectively. Serum metabolites were quantified by the Beckman Synchron LX20 (glucose, lipids), immunoassay (insulin) and HPLC (methylglyoxal). Serum glutathione was determined by assaying glutathione transferase activity spectrophotometrically. Results: Compared to the control and LIS diets, the HIS diet significantly increased body weight and serum insulin levels, and reduced serum glucose and methylglyoxal levels. Serum glutathione levels were increased in HIS-fed rats compared to the control or LIS rats (p b 0.01). Serum high-density lipoprotein cholesterol was significantly higher in HIS-fed rats than in the control or LIS rats (p b 0.05). Immunohistostaining demonstrated increased insulin production in the pancreatic islets of Langerhans in diabetic rats treated with the HIS. More importantly, the death rate and incidence of cataracts in the diabetic rats were markedly decreased in the HIS group. Conclusions: Ingestion of a high isoflavone soy protein diet not only lowers glucose levels but also reduces the incidence of cataracts in diabetic rats. The beneficial effects of soy
isoflavones are attributed to increased insulin secretion, better glycemic control, and antioxidant protection. doi:10.1016/j.clinbiochem.2008.08.046
151 Evaluation of mathematical indices based on CBC parameters in discriminating iron status from thalassemia Khajuria A., Higgins T.N. DynaLIFEDX, Edmonton, Alberta, Canada Objectives: To evaluate if CBC parameter based mathematical indices could discriminate between patients who had normal status or iron deficient from those with thalassemia. Methods: CBC parameters from 161 subjects with a normal CBC (RBC normal, Hb normal, MCV 80–100 fL), 173 iron deficient subjects (RBC normal, Hb b 120 g/L, MCV b 80 fL) and 322 subjects with thalassemia (RBC high, Hb N 160 g/L, MCV b 74 fL) were evaluated using the MCV alone, Mentzer Index (MCV/RBC), Discriminant Factor (Green and King Index) ((MCV 2 × RDW) / 100 × Hb), Shine and Lal Index ((MCV2) × (MCH/100)), Srivastava Index (MCH/RBC) and the RDW Index (MCV × RDW/RBC). ROC curves were generated for each calculation to determine the optimal cutpoints for discrimination between normal iron status, iron deficiency and thalassemia. Results: Indices
MCV Mentzer index Discriminant factor Shine and Lal index Srivastava index RDW index
Normal iron vs iron deficient
Iron deficient vs thalassemia
Sensitivity
Specificity
Sensitivity
Specificity
100 64 74 92 74 80
70 80 80 100 80 60
76 80 92 70 90 92
75 97 100 80 91 100
Conclusions: A single cut-point in any of the indices could not distinguish between normal iron status and iron deficiency and between iron deficiency and thalassemia. The use of two cut-points, the first to distinguish normal iron status from iron deficiency and the second to distinguish iron deficiency from thalassemia gave the best discrimination. However, no index gave 100% specificity and sensitivity. doi:10.1016/j.clinbiochem.2008.08.047
152 Alpha-site evaluation of the Abbott ARCHITECT c4000 clinical chemistry analyzer Kerekes R., Martin A., Brown P., Carlson M.L., Johnston G. InterHospital Laboratory Partnership, Stratford, Ontario, Canada
ABSTRACTS / Clinical Biochemistry 41 (2008) 1263–1287
3 min, then from 3.0 to 7.4 min the methanol gradient was increased from 74 to 77% methanol. From 7.4 to 9.0 min the column was cleaned with 100% methanol. Chromatographic running time was 9.0 min and calibration curves were linear from 0.1 to 2.0 ng/mL for C13-T4 and 5 to 150 ng/mL for C12-T4. The lower limit of quantification (LLOQ) was 0.01 ng/mL for C13-T4 and 5.0 ng/mL for C12-T4. Results and discussion: This method demonstrates excellent specificity, accuracy and precision (CVs of 4.1–6.2 at 2.6– 11.9 μg/dL C12-T4 and 9.2% at 2.0 ng/mL C13-T4). Administration of 100 μg of C13-T4 to a normal control gave concentrations of C13-T4 (ng/mL) and C12-T4 (μg/dL) at t = 0, 3.6 and 18 h of 0.00, 6.9; 0.99, 7.4 and 0.7, 7.5 respectively. Conclusions: The method is simple, specific and precise and allows C13- and C12-T4 to be simultaneously quantified. doi:10.1016/j.clinbiochem.2008.08.045
150 Antihyperglycemic effect and mechanisms of soy isoflavones in streptozotocin-induced diabetic rats Meng Q.H.1, Lu M.P.1, Wang R2, Song X1, Chibbar R.1, Wang X.3, Wu L.3 1,3 University of Saskatchewan, Saskatoon, SK, Canada 2 Lakehead University, Canada Objective: Incorporating soy isoflavones in the diet leads to beneficial effects on diabetes, but the metabolic changes and mechanisms underlying the improvement are incompletely understood. In this study, we fed varying amounts of soy isoflavones to streptozotocin (STZ)-induced diabetic rats and documented the resulting beneficial effects and associated metabolic changes. Methods: Diabetic rats were randomly divided into 3 groups and fed a special diet supplemented with either casein (control), low-isoflavone soy protein (LIS), or high-isoflavone soy protein (HIS) for 8 weeks, respectively. Serum metabolites were quantified by the Beckman Synchron LX20 (glucose, lipids), immunoassay (insulin) and HPLC (methylglyoxal). Serum glutathione was determined by assaying glutathione transferase activity spectrophotometrically. Results: Compared to the control and LIS diets, the HIS diet significantly increased body weight and serum insulin levels, and reduced serum glucose and methylglyoxal levels. Serum glutathione levels were increased in HIS-fed rats compared to the control or LIS rats (p b 0.01). Serum high-density lipoprotein cholesterol was significantly higher in HIS-fed rats than in the control or LIS rats (p b 0.05). Immunohistostaining demonstrated increased insulin production in the pancreatic islets of Langerhans in diabetic rats treated with the HIS. More importantly, the death rate and incidence of cataracts in the diabetic rats were markedly decreased in the HIS group. Conclusions: Ingestion of a high isoflavone soy protein diet not only lowers glucose levels but also reduces the incidence of cataracts in diabetic rats. The beneficial effects of soy
isoflavones are attributed to increased insulin secretion, better glycemic control, and antioxidant protection. doi:10.1016/j.clinbiochem.2008.08.046
151 Evaluation of mathematical indices based on CBC parameters in discriminating iron status from thalassemia Khajuria A., Higgins T.N. DynaLIFEDX, Edmonton, Alberta, Canada Objectives: To evaluate if CBC parameter based mathematical indices could discriminate between patients who had normal status or iron deficient from those with thalassemia. Methods: CBC parameters from 161 subjects with a normal CBC (RBC normal, Hb normal, MCV 80–100 fL), 173 iron deficient subjects (RBC normal, Hb b 120 g/L, MCV b 80 fL) and 322 subjects with thalassemia (RBC high, Hb N 160 g/L, MCV b 74 fL) were evaluated using the MCV alone, Mentzer Index (MCV/RBC), Discriminant Factor (Green and King Index) ((MCV 2 × RDW) / 100 × Hb), Shine and Lal Index ((MCV2) × (MCH/100)), Srivastava Index (MCH/RBC) and the RDW Index (MCV × RDW/RBC). ROC curves were generated for each calculation to determine the optimal cutpoints for discrimination between normal iron status, iron deficiency and thalassemia. Results: Indices
MCV Mentzer index Discriminant factor Shine and Lal index Srivastava index RDW index
Normal iron vs iron deficient
Iron deficient vs thalassemia
Sensitivity
Specificity
Sensitivity
Specificity
100 64 74 92 74 80
70 80 80 100 80 60
76 80 92 70 90 92
75 97 100 80 91 100
Conclusions: A single cut-point in any of the indices could not distinguish between normal iron status and iron deficiency and between iron deficiency and thalassemia. The use of two cut-points, the first to distinguish normal iron status from iron deficiency and the second to distinguish iron deficiency from thalassemia gave the best discrimination. However, no index gave 100% specificity and sensitivity. doi:10.1016/j.clinbiochem.2008.08.047
152 Alpha-site evaluation of the Abbott ARCHITECT c4000 clinical chemistry analyzer Kerekes R., Martin A., Brown P., Carlson M.L., Johnston G. InterHospital Laboratory Partnership, Stratford, Ontario, Canada