Background and Purpose-Although the relation between serum LDL cholesterol level and coronary heart disease (CHD) is well established, its relation with stroke subtypes is less clear. Methods-A total of 2351 inhabitants age Ն40 years in a Japanese community were followed up for 19 years. Results-During follow-up, 271 subjects developed stroke and 144 developed CHD. Whereas the age-and sex-adjusted incidences of CHD significantly increased with increasing LDL cholesterol levels (P for trend Ͻ0.001), the associations between LDL cholesterol level and the incidences of ischemic or hemorrhagic stroke were not significant. The age-and sex-adjusted incidences of atherothrombotic infarctions (ATIs) and lacunar infarctions (LIs) significantly increased with increasing LDL cholesterol level (P for trendϭ0.03 for ATIs andϭ0.02 for LIs), but no such association was observed for cardioembolic infarction. After multivariate adjustment, the positive associations of LDL cholesterol level with the risks of ATI and CHD remained significant (P for trendϭ0.02 for ATIs andϭ0.03 for CHD), whereas the association with LIs was not significant. The risk of ATI significantly increased in the fourth quartile of LDL cholesterol compared with the first quartile (multivariate-adjusted hazard ratioϭ2.84; 95% CI, 1.17 to 6.93). The multivariate-adjusted risks for developing nonembolic infarction (ATIs and LIs) and CHD were significantly elevated in the groups with elevated LDL cholesterol values with and without the metabolic syndrome. Conclusions-Our findings suggest that an elevated LDL cholesterol level is a significant risk factor for developing ATI as well as CHD, and these associations are independent of the metabolic syndrome. (Stroke. 2009;40:382-388.)

Monitoring resistance allele frequency at the early stage of resistance development is important for the successful acaricide resistance management. Etoxazole is a mite growth inhibitor to which resistance is conferred by an amino acid substitution in the chitin synthase 1 (CHS1; I1017F) in T. urticae. If the susceptible allele can be specifically digested by restriction endonuclease, the ΔΔCt method using real-time PCR for genomic DNA (RED-ΔΔCt method) may be available for monitoring the resistance allele frequency. We tested whether the etoxazole resistance allele frequency in a pooled sample was accurately measured by the RED-ΔΔCt method and validated whether the resistance variant frequency was correlated with etoxazole resistance phenotype in a bioassay. Finally, we performed a pilot test using field populations. Strong linearity of the measures by the RED-ΔΔCt method with practical resistance allele frequencies; resistance allele frequency in the range between 0.5% to at least 0.75% was strictly represented. The strong linear relationship between hatchability of haploid male eggs after the etoxazole treatments (phenotype) and resistance allele frequencies in their mothers provided direct evidence that I1017F is a primary resistance factor to etoxazole in the strains used for experiments. The pilot test revealed a significant correlation between egg hatchability (including both diploid female eggs and haploid male eggs) and estimators in field populations. Consequently, we concluded that the RED-ΔΔCt method is a powerful tool for monitoring a resistance allele in a pooled sample.

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Due to the development of acaricide resistance in Tetranychus urticae, a rapid and accurate monitoring method for acaricide resistance gene frequency is required for resistance management.In this study, we developed a new diagnostic gene frequency prediction method, using quantitative real-time PCR with allele-specific primer sets, for mutation of I1017F in chitin synthase I, G126S in mitochondrial cytochrome b, and H110R in the PSST subunit of mitochondrial electron transport complex I, which are involved in etoxazole, bifenazate, and pyridaben resistance in T. urticae, respectively. Resistance allele frequencies computed using the 2 −ΔΔCq method, in mixtures of resistance and wild-type (susceptible) alleles, were strongly correlated with the actual frequencies of the resistance alleles in DNA samples for all three acaricides (regression slopes of 0.945-0.996; R 2 > 0.99). This result strongly indicates that resistance allele frequency in a population can be accurately predicted using a diagnostic quantitative real-time PCR method with a resistance allele-specific primer set. Finally, we applied this method to nine field populations and successfully determined resistance allele frequencies for the three acaricides. Overall, this diagnostic prediction method may contribute to the development of acaricide resistance management strategies, via monitoring resistance allele frequencies for a wide range of acaricides.

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