Deficiency or activation of peroxisome proliferator-activated receptor α reduces the tissue concentrations of endogenously synthesized docosahexaenoic acid in C57BL/6J mice

BACKGROUND/OBJECTIVES: Docosahexaenoic acid (DHA), an n-3 long chain polyunsaturated fatty acid (LCPUFA), is acquired by dietary intake or the in vivo conversion of α-linolenic acid. Many enzymes participating in LCPUFA synthesis are regulated by peroxisome proliferator-activated receptor alpha (PPARα). Therefore, it was hypothesized that the tissue accretion of endogenously synthesized DHA could be modified by PPARα. MATERIALS/METHODS: The tissue DHA concentrations and mRNA levels of genes participating in DHA biosynthesis were compared among PPARα homozygous (KO), heterozygous (HZ), and wild type (WT) mice (Exp I), and between WT mice treated with clofibrate (PPARα agonist) or those not treated (Exp II). In ExpII, the expression levels of the proteins associated with DHA function in the brain cortex and retina were also measured. An n3-PUFA depleted/replenished regimen was applied to mitigate the confounding effects of maternal DHA. RESULTS: PPARα ablation reduced the hepatic Acox, Fads1, and Fads2 mRNA levels, as well as the DHA concentration in the liver, but not in the brain cortex. In contrast, PPARα activation increased hepatic Acox, Fads1, Fads2 and Elovl5 mRNA levels, but reduced the DHA concentrations in the liver, retina, and phospholipid of brain cortex, and decreased mRNA and protein levels of the brain-derived neurotrophic factor in brain cortex. CONCLUSIONS: LCPUFA enzyme expression was altered by PPARα. Either PPARα deficiency or activation-decreased tissue DHA concentration is a stimulus for further studies to determine the functional significance.

Progress in molecular identification of snake drugs / 中国中药杂志

Snake drugs have high values in clinical medication for anti-inflammatory, analgesia activities and dredging collaterals. However, owing to their deficient resource and substantial profit, many counterfeits for snake drugs have appeared on the market. Traditional methods for Chinese medicine authentication include identification of origin, morphology identification, microscopy and physiochemical identification. But these methods are restricted in application because of their high morphological requirement for specimens, complex process for assays and indeterminate results guided by subjective. With the development of molecular biology and molecular genetic techniques, new theories and technologies for molecular detection have been introduced to the authentication of Chinese medicine, such as RAPD, specific PCR amplification, DNA barcoding analysis and so on, improved the authentication system of Chinese medicine. Here, we will give a brief review of molecular detection methods for snake drugs authentication.

Quantitative pyrosequencing of heterozygous single nucleotide polymorphisms for rapid diagnosis of Down's syndrome / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To establish a method to detect Down's syndrome through quantitative pyrosequencing of the heterozygous single nucleotide polymorphisms (SNPs) on the chromosome 21.</p><p><b>METHODS</b>An improved allele-specific-amplification was used to screen heterozygous SNPs on the chromosome 21 from 84 normal samples. Pyrosequencing was used to quantitatively determine the ratio between the two alleles of a heterozygote, and the diagnosis of Down's syndrome was thus carried out based on the ratio.</p><p><b>RESULTS</b>By genotyping 84 genomic DNA samples from normal Chinese population, 6 SNPs with a relatively high level of heterozygosity were screened out. Heterozygote coverage of 92.9% was achieved by using a panel of 6 SNPs on the chromosome 21. Ten clinical samples from Down's syndrome patients were quantitatively determined by pyrosequencing, and 9 samples were accurately diagnosed by comparing the ratio of the two alleles. The pyrosequencing results showed that the ratio of the two alleles were 2:1 or 1:2 for the Down's syndrome patients.</p><p><b>CONCLUSION</b>The method has the advantage of a low cost, simple process, and time-saving operation and could be potentially applicable to the rapid diagnosis of Down's syndrome.</p>

Direct multiplex-PCR from whole blood for rapid detection of Y chromosome microdeletions / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To establish a rapid and simple method to detect Y chromosome microdeletions directly using whole blood as starting material for multiplex-PCR.</p><p><b>METHODS</b>Using a self-prepared pHpH-Bufferq, multiplex-PCR amplification was directly carried out from the anticoagulant whole blood sample without DNA extraction step. Twelve sequence tagged sites (STS), namely SY84, SY86, SY127, SY134, SY124, SY132, SY152, SY157, SY239, SY242, SY254 and SY255, in AZFa, AZFb, and AZFc gene regions were detected in 5 different tubes. In order to ensure the validity of the experiments, sex-determining region Y (SRY) and X-linked or Y-linked zinc finger gene (ZFX/Y) were used as internal controls. Furthermore, conventional PCR using genomic DNA extracted from each blood sample was performed in parallel for evaluating the accuracy of the experiments.</p><p><b>RESULTS</b>A total of 156 male samples were detected, and a normal male sample and a female sample were used as a positive and a negative control respectively. The results showed that 144 samples had no deletion; one sample was AZF-deleted; one sample was AZFb-deleted; seven samples were AZFc-deleted; one sample was both AZFb- and AZFc- deleted; and two samples were all AZFa-, AZFb- and AZFc- deleted. The observed results from two kinds of starting material (whole blood and purified DNA) are completely consistent.</p><p><b>CONCLUSION</b>In our method, PCR amplification was directly carried out from whole blood without any DNA extraction step. So it has the advantages of low cost, simple process, time-saving operation and less cross-contamination. The whole process can be completed within 2 hours. Thus the efficiency of clinical detection is improved greatly.</p>