Ethnic disparities in risk of cardiovascular disease, end-stage renal disease and all-cause mortality: a prospective study among Asian people with Type 2 diabetes.

AIM: To study prospectively the ethnic-specific risks of cardiovascular disease, end-stage renal disease and all-cause mortality in patients with Type 2 diabetes mellitus among native Asian subpopulations. METHODS: A total of 2337 subjects with Type 2 diabetes (70% Chinese, 17% Malay and 13% Asian Indian) were followed for a median of 4.0 years. Time-to-event analysis was used to study the association of ethnicity with adverse outcomes. RESULTS: Age- and gender-adjusted hazard ratios for cardiovascular disease in ethnic Malay and Asian Indian subjects were 2.01 (1.40-2.88; P<0.0001) and 1.60 (1.07-2.41; P=0.022) as compared with Chinese subjects. Adjustment for conventional cardiovascular disease risk factors, including HbA1c , blood pressure and lipid profile, slightly attenuated the hazards in Malay (1.82, 1.23-2.71; P=0.003) and Asian Indian subjects (1.47, 0.95-2.30; P=0.086); However, further adjustment for baseline renal function (estimated GFR) and albuminuria weakened the cardiovascular disease risks in Malay (1.48, 0.98-2.26; P=0.065) but strengthened that in Asian Indian subjects (1.81, 1.14-2.87; P=0.012). Competing-risk regression showed that the age- and gender-adjusted sub-distribution hazard ratio for end-stage renal disease was 1.87 (1.27-2.73; P=0.001) in Malay and 0.39 (0.18-0.83; P=0.015) in Asian Indian subjects. Notably, the difference in end-stage renal disease risk among the three ethnic groups was abolished after further adjustment for baseline estimated GFR and albuminuria. There was no significant difference in risk of all-cause mortality among the three ethnic groups. CONCLUSIONS: Risks of cardiovascular and end-stage renal diseases in native Asian subjects with Type 2 diabetes vary substantially among different ethnic groups. Differences in prevalence of diabetic kidney disease may partially explain the ethnic disparities.

Production and Characterization of Antibody Against PR Toxin.

Antibody against PR toxin was produced after immunizing rabbits with an immunogen prepared by conjugation of PR toxin to bovine serum albumin by a reductive alkylation method. A competitive radioimmunoassay (RIA) was used to determine the antibody specificity. The concentration causing 50% inhibition of binding of 3H-tetrahydro-PR toxin to the antibody by unlabeled PR toxin, tetrahydro-PR toxin, PR imine, eremofortin C (EC), acetyl-EC (Ac-EC), eremofortin D (ED) and eremofortin A (EA) were 7, 10, 5, 15, 50, 500 and 800 ng/assay, respectively; for PR alcohol and eremofortin B (EB), the concentration was greater than 10,000 ng/assay. The practical application of using this antibody for RIA of PR toxin was tested by spiking cheese with the toxin. PR toxin was then extracted with ethyl acetate, and analyzed by RIA. The overall recovery for 20 samples with 0.1 to 50 ppm of PR toxin was 93%.

Production and Characterization of Antibodies against Fumonisin B1.

Polyclonal antibodies against fumonisin B1 (FmB1) were produced in rabbits after immunizing the animals with either FmBl-keyhole limpet hemocyanin (KLH) or FmB1 bovine serum albumin (BSA). A direct competitive enzyme-linked immunosorbent assay (dc-ELISA) and an indirect competitive ELISA (idc-ELISA) were used for the characterization of the antibodies and for analysis of the toxin in corn samples. The antibody titers in the serum of rabbits immunized with FmBl-KLH were considerably higher than in those immunized with FmBl-BSA. The antibodies from the rabbits immunized with FmBl-KLH were further characterized. The concentrations causing 50% inhibition of binding of FmB1-horseradish peroxidase (HRP) to the antibodies by FmB1, FmB2 and FmB3 in the ELISA were found to be 0.45, 0.72, and 25 ng/ml, respectively. The detection limit of FmBl, based on 95% confidence at 5% of inhibition of binding of FmBl-HRP conjugate, in buffer of the dc-ELISA was found to be 0.05 ng/ml. In the presence of a matrix such as corn, the detection limit was less than 50 ppb. The overall analytical recoveries of FmBl (50 to 1,000 ng/g) added to the ground corn and then extracted with CH3CN/H2O (1/1, vol/vol) with cleanup and without cleanup in the dc ELISA were found to be 70.5 and 85.9%, respectively. A good correlation was found between the FmBl levels in 2 starch and 10 naturally contaminated corn samples analyzed by the dc-ELISA and the high-pressure liquid chromatography (HPLC) method. The correlation coefficients between ELISA and HPLC were found to be 0.955 (y [ELISA] = 1.3 1x [HPLC] + 77 ppb; P < 0.001) and 0.811 (y = 1.13x + 34 ppb; P < 0.01) for the sample without and with cleanup treatment, respectively.

ELISA of Picogram Quantities of Aflatoxin M1 in Urine and Milk.

Pretreatment of milk or urine with a Sep-Pak C-18 reversed-phase cartridge permits detection by direct enzyme-linked immunosorbent assay (ELISA) of 10 to 25 pg/ml of aflatoxin M1 added to samples. The samples were first loaded to the Sep-Pak cartridge followed by washing with 10% acetonitrile in water. Aflatoxin M1 was eluted from the cartridge with 30% acetonitrile in water and then transferred to the methylene chloride. After the solvent was removed, the sample was redissolved in 50 µl of methanol, diluted with 0.45 ml of buffer, and finally subjected to the ELISA. The recovery of aflatoxin M1 added to milk and urine in the range of 10 to 250 pg/ml was between 77 to 110%.