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Biomedical subjects

T L Kuo

Publications and source records attributed to T L Kuo.

At least 37 records · Page 2Linked to original sources
PubMed1988

Determination of paraquat from formalin-fixed tissue.

In this paper, a sulfuric acid digestion method and a clean-up technique by using cation exchange resin followed by XAD-2 resin has been developed for the determination of paraquat from formalin-fixed tissue at the submicrograms per gram level. Formalin-fixed tissue is dissolved by hot sulfuric acid, then paraquat is isolated and purified with cation exchange chromatography. The eluted paraquat forms an ion-pair with sodium dodecyl sulfate, it is then adsorbed on XAD-2 resin. Paraquat is eluted, extracted and reduced with solvent mixtures, NaCl solution and dithionite reagent, respectively. The calibration graphs of zero-order and second-derivative spectroscopy are linear in the range of 0.01-5.0 mg/kg. The relative standard deviation was less than 5% and the detection limit was 0.02 mg/kg based on 0.5-g samples. The sensitivity of the proposed method could be increased by using larger sample sizes. The method was precise and gave a quantitative recovery of paraquat spiked into formalin-fixed liver homogenates (78%). The proposed method has been satisfactorily applied to the determination of paraquat in the formalin-fixed tissues of suspected poisoned cases. It has been shown to be of great value in the field of forensic toxicology especially when formalin-fixed tissue only is available.

Adult↗
PubMed1987

Comparison of the effect of acetylsalicylic acid on platelet function in male and female patients with ischemic stroke.

The aim of this study was to observe whether acetylsalicylic acid (ASA) had different effects in both sexes. Out of the ischemic stroke patients who were admitted to the National Taiwan University Hospital (NTUH), those who had not taken ASA or ASA-like drugs for more than 2 weeks were selected for this study. For the diagnosis of ischemic stroke, computed tomography (CT) of the brain was performed in all cases, and for differential diagnosis, other necessary procedures were employed in a few cases. The serum salicylate (SA) level was measured by Trinder's method, thromboxane B2 (TXB2) and 6-keto-PGF1 alpha by radioimmunoassay, threshold concentration of adenosine diphosphate (ADP) by Born's method, and circulating platelet aggregates (CPA) by Wu and Hoak's method. The present study showed that the means of serum SA levels after administration of the same dose of ASA were not significantly different between the two sexes. After ingestion of ASA, a single dose of 75 mg, 300 mg or 600 mg, or 300 mg 4 times a day, mean plasma TXB2 levels were significantly suppressed and mean threshold concentrations of ADP were significantly elevated in the two sexes. After administration of above-mentioned various doses of ASA, the abnormally high plasma TXB2 levels and abnormally low threshold concentrations of ADP and CPA ratios were significantly normalized in both male and female patients. Plasma 6-keto-PGF1 alpha levels were not influenced by ingestion of ASA 75 mg, but significantly depressed by administration of ASA 300 mg in both sexes. There were no sex differences in the antiplatelet effect of ASA in this experiment.

6-Ketoprostaglandin F1 alpha↗
PubMed1987

Determination of paraquat in tissue using ion-pair chromatography in conjunction with spectrophotometry.

Homogenized tissue was deproteinized with sulfuric acid. Paraquat in the supernatant was quantificated directly with the dithionite reagent (step 1) or concentrated by the XAD-2 column chromatographic technique before paraquat determination (step 2). Tissue paraquat levels in the range of 0.01-75 mg/kg could be quantificated by second-derivative or zero-order spectroscopy using 2.5 g of tissues. The sensitivity could be increased tenfold by using 25 g of tissue samples. The coefficients of variation of within-run and day-to-day precisions of spiked paraquat in tissue homogenates were below 5% at concentrations of 10.0, 1.0 and 0.1 mg/kg, respectively. The recoveries of the spiked paraquat in tissues ranging from 0.1-10 mg/kg were 91% by step 1 and 74% by step 2. Using these simple methods, steps 1 and 2, the paraquat concentrations in the psoas muscle, liver, lung and kidneys of a swine dosed with 0.16 g/kg of paraquat were investigated. The results were in close agreement with those of the TCA deproteinization method followed by cation-resin column chromatography. The proposed method offers the advantages of simplicity, rapidity, reasonable sensitivity and a wide range of concentrations.

Animals↗
PubMed1986

Derivative spectroscopic determination of paraquat in serum.

A reliable and sensitive method is described for the quantitative determination of the herbicide paraquat in serum. It involves the formation of dodecyl sulfate-paraquat ion pairs, adsorption of these ion-pairs on XAD-2 resin, and determination of the sensitive derivative spectrum of reduced paraquat. Analytical recovery of paraquat added to serum was about 86% at concentrations of 0.02-1.0 mg/L. Assay sensitivity is 0.005 mg/L, but this could be increased two- to fivefold by using greater volumes (4-10 mL) of serum/plasma without encountering problems of turbidity. The proposed method also avoids interferences from severe jaundice, which generally occurs in patients with paraquat poisoning.

Chromatography, Ion Exchange↗