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Biomedical subjects

B H Chen

Publications and source records attributed to B H Chen.

90 records · Page 5Linked to original sources
PubMed1988

Pulmonary injury in laboratory animals induced by Huai-Nan coal mine respirable dust.

The BAL technique was used to assess the pulmonary injury of coal dust and rock dust in Huai-Nan coal mine in Anhui Province. Dust suspended in saline and dust-free supernatant were instilled intratracheally to Wistar rats and Syrian hamsters. Saline was used in treating controls. The animals were sacrificed 24 h after treatment, their lungs were lavaged, and pulmonary damage was evaluated by cellular and biochemical assays of lavage fluid. Pulmonary injury was expressed by the cell toxicity index (CTI). CTI is the product of the number of times of meaningful parameters for treated groups compared to controls (LDH, acid phosphatase, and polymorphonuclear neutrophils in this case). The CTI values were found to be 5.19, 2.28, and 5.15 for rock dust, coal dust, and Shanghai suspended particulates, respectively. The toxicity of rock dust is higher than that of coal dust, but is similar to that of Shanghai suspended particulates. The cell toxicity of dust suspension solution is higher than that of dust-free supernatant. CTI can be used as an indicator of the relative toxicity of respirable dusts in in vivo studies.

Acid Phosphatase↗
PubMed1987

Total and free disopyramide by fluorescence polarization immunoassay and relationship between free fraction and alpha-1 acid glycoprotein.

Disopyramide is an antiarrhythmic drug with concentration dependent protein binding within the therapeutic range. We found good agreement between fluorescence polarization immunoassay (FPIA, Abbott TDX) and high performance liquid chromatography (HPLC) for total disopyramide among 27 admission patients' sera (FPIA = 1.12 (HPLC) -0.002, r = 0.982, SEE = 0.378 mg/l). Agreement between FPIA and HPLC for free disopyramide was similarly good (FPIA = 0.867 (HPLC) -0.003, r = 0.986, SEE = 0.09 mg/l, n = 27). Serum alpha 1 acid glycoprotein concentration (AAG) and free fraction (FF) percent of disopyramide correlated inversely (FF = -0.0112 (AAG) + 31.3 r = 0.707, SEE = 6.41 mg/l, n = 24), and the free disopyramide fraction varied greatly. For two pooled sera with 12 different disopyramide concentrations (range from 0.5-20.0 mg/l), the proportion of free fraction ranged from 6.5 to 73.2%. Overall, we found the free disopyramide fraction variable with each individual, total drug, and protein concentration. Therefore, free drug concentration should be monitored in disopyramide therapy, and FPIA is reliable for free as well as total drug assay.

Chromatography, High Pressure Liquid↗
PubMedDate not supplied

Comparison of derivatives for determination of codeine and morphine by gas chromatography/mass spectrometry.

Pentafluoropropionic anhydride (PFPA) and heptafluorobutyric anhydride (HFBA) derivatives of morphine and codeine demonstrated poor spectra due to low abundances of secondary and tertiary ions. Trifluoroacetamide (MBTFA) has been a widely used derivative; however, the internal standard, nalorphine, displayed very poor stability and this resulted in split peaks by gas chromatography making MBTFA unsuitable for quantitative methods. Quantitation of codeine and morphine using bis-trimethylsilyltrifluoroacetamide (BSTFA/1%TMS) revealed a significant gradual decrease (p less than 0.05) of peak area ratio (PAR) of codeine and morphine compared to the internal standard using selected ion monitoring (SIM). The acetic anhydride derivative showed no significant differences in the peak area ratios for codeine/IS over a period of 24 hours, although the coefficient of variation (CV) was higher for the acetyl derivative than for the TMS derivative of codeine. There was a significant difference associated with the acetyl derivative of morphine at 4 h post derivatization compared to the initial injection (p less than 0.05); however, the acetyl derivative was stable for 24 hours and had a CV of less than 10% at a cutoff of 300 ng/mL.

Acetamides↗