ABSTRACT
Objective To explore a fast, effective and noninvasive method of genomic DNA extraction. Methods We compared the genomic DNAs extracted by two DNA extraction methods of potassium iodide (KI) and Kit from saliva (fresh and placed a week at room temperature), and PCR amplifications were done for TP53 and PRB-3 genes from their extracted DNA. Ninety-nine healthy children and adults were recruited and their saliva samples were collected to detect the stability of DNA extracted by KI. Results High quality genomic DNAs were extracted by both methods from the fresh saliva. The DNA yield based on KI was (1.91±0.15) μg, with the D260/D280 being 1.99±0.05, and that of Kit was (2.64±0.34) μg, with the D260/D280 being 1.81±0.02. Although the extracted DNAs had obvious degradation from saliva samples placed for a week at room temperature, the expectant DNA fragments were successfully amplified by PCR for TP53 and PRB-3 genes using these extracted DNAs. Although the genomic DNAs from saliva samples of 99 healthy volunteers by the method of KI showed individual difference (DNA yield was [1.89±0.46] μg), the DNA quality was stable and reliable (D260/D280 was 1.96±0.10). Conclusion KI method for extracting genomic DNA from saliva is not only cheap and highly effective, but also noninvasive, making it suitable for large-scale epidemiological studies.
ABSTRACT
<p><b>OBJECTIVE</b>To analyze the metabolic states of the lipids, protein, carbohydrate, and nucleic acid for chronic superficial gastritis patients of splenasthenic syndrome (SS), and to explore the pathogenesis mechanism of SS based on substance and energy metabolisms.</p><p><b>METHODS</b>During June 2004 to March 2005, recruited were four chronic superficial gastritis patients of SS who visited at the First Hospital of Guangzhou University of Chinese Medicine and Guangdong Provincial Hospital of Traditional Chinese Medicine. Four healthy volunteers were recruited from Guangzhou University of Chinese Medicine. Their gastric mucosa was extracted to perform experiments of DNA microarray. The dual-channel DNA microarray data were mined and bioinformatics analyzed by BRB ArrayTools and IPA software.</p><p><b>RESULTS</b>Fifteen genes were involved in substance and energy metabolisms in 20 differentially expressed genes, accounting for 75%.Among these genes, one gene was up-regulated, 14 genes down-regulated, and 11 genes were enzyme gene. Differentially expressed genes related to lipid metabolism included ACAA2 and CYP20A1, manifested as fatty acid catabolism and cholesterol transformation. Genes related to protein metabolism included ALDH9A1, ASL, ASS1, PCY-OX1L, RPS28, UBE2D2, UBXN1, B3GNT1, GCNT1, and PPP1R3C, manifested as decreased amino acid metabolism that may affect the biologic processes such as autonomic nerve, urea cycle, etc., reduced protein synthesis, increased ubiquitination of fault fold proteins, and decreased post-translated modification of glycosylation and dephosphorylation. Genes related to carbohydrate metabolism included PPP1R3C, B3GNT1, and GCNT1, manifested as decreased glycogen and glycan syntheses. Genes related to nucleic acid metabolism included RMI1, SMARCD3, and PARP1, manifested as degraded DNA duplication and transcription, and increased DNA damage repair.</p><p><b>CONCLUSIONS</b>The metabolisms of the lipids, protein, carbohydrate, and nucleic acid in chronic superficial gastritis patients of SS obviously decreased, manifested mainly as down-regulated enzyme gene expression. We inferred that these might be one of the vital pathogenesis mechanisms for nutrition dysmetabolism of SS.</p>