A point mutation which caused a silent phenotype of human serum butyrylcholinesterase (BChE) was identified in the genomic DNA of a 57-year-old Japanese woman who visited our hospital because of pneumonia. The propositus exhibited an unusually low level of BChE activity, whereas her son and daughter had an intermediate level. Immunologically, there was an absence of BChE protein in the propositus's serum. DNA sequence analysis of the propositus demonstrated a point mutation at codon 365 (GGA-CGA), resulting in a Gly-Arg substitution. A family study showed her son and daughter to have the same mutation.
Title: [Studies on the stability of 89 pesticides in organic solvent] Nemoto S, Takatsuki S, Sasaki K, Toyoda M Ref: Kokuritsu Iyakuhin Shokuhin Eisei Kenkyusho Hokoku, 115:86, 1997 : PubMed
The stability of 89 pesticides (17 organochlorine, 33 organophosphorus, 8 pyrethroid, 12 carbamate, and 19 other pesticides) in 6 kinds of organic solvents (methanol, ethanol, 2-propanol, ethyl acetate, n-hexane, and acetone) was investigated using gas chromatography/mass spectrometry (GC/MS). All of the investigated pesticides were stable in all of the tested organic solvents during storage for 6 hours at room temperature in the dark except captafol, captan, phosmet, chinomethionat, and dicofol. However, the decreases of captafol, captan, phosmet, and chinomethionat were observed in methanol. The decreases of captafol, captan, and phosmet were also observed in ethanol. Moreover, the decrease of dicofol was observed in acetone. The decrease of captafol dissolved in methanol at a concentration of 2 micrograms/ml was faster than those of captan, phosmet, and chinomethionat; the residual captafol was 75% after 30 min of storage. Dicofol dissolved in acetone also decreased during storage in a refrigerator. 4,4'-dichlorobenzophenone (DCBP) and chlorobutanol were detected in the acetone solution of dicofol after storage. Furthermore, it was found that dicofol was decomposed by acetone at an injection port, and DCBP and chlorobutanol were formed when it was injected into GC with acetone.
Title: Simple analytical method for organophosphorus pesticide residues in milk Toyoda M, Adachi K, Ida T, Noda K, Minagawa N Ref: J Assoc Off Analytical Chemistry, 73:770, 1990 : PubMed
A simple method for determination of organophosphorus pesticide residues at the parts per million level in milk was developed. Pesticide residues were extracted with acetonitrile added to aqueous milk, fat was removed by zinc acetate addition and dichloromethane partition, and analytes were concentrated and analyzed by wide-bore capillary column gas chromatography. Recoveries of 6 pesticides spiked in milk samples at levels of 0.1 and 1.0 micrograms/mL were 82.1-93.8% and 79.7-96.6%, respectively. Triplicate samples spiked with 6 pesticides at 1 microgram/mL were analyzed independently by 3 laboratories. Average recoveries were greater than 80%, and the mean coefficients of variation for the complete study were 2.9% for diazinon, 5.4% for dimethoate, 4.6% for malathion, 4.6% for parathion, 4.9% for EPN, and 6.1% for phosalone.
