dnaH

Abstract: A commercial DNA hybridization assay (DNAH) for rapid detection of Salmonella in foods was compared to the conventional culture procedure. The DNAH method employed preenrichment, selective, and post-enrichment steps (44°hr) prior to performing the assay (4hr). Confirmation of positive DNAH assays was accomplished using standard culture methods for isolation of Salmonella. More than 1,600 samples were tested, representing 23 food types and including naturally contaminated, artificially inoculated, and uninoculated foods. Based on the data generated, the DNAH method was as productive as the standard culture method for detection of Salmonella in all foods and was significantly better than the culture method for certain foods.

Abstract: The dynein axonemal heavy chain (DNAH) family of genes encode the dynein axonemal heavy chain, which is involved in cell motility. Genomic variations of DNAH family members have been frequently reported in diverse kinds of malignant tumors. In this study, we analyzed the genomic database to evaluate the mutation status of DNAH genes in gastric adenocarcinoma and further identified the significance of mutant DNAH genes as effective molecular biomarkers for predicting chemotherapy response in gastric cancer patients. We analyzed the clinical and genomic data of gastric cancer patients published in The Cancer Genome Atlas (TCGA) project. Data on chemotherapy response, overall survival (OS) and chemotherapy-free survival were retrieved. Then, we verified the results via targeted sequencing of gastric cancer patients with similar clinical characteristics but different chemotherapeutic outcomes. In total, 132 gastric adenocarcinoma patients undergoing chemotherapy treatment from TCGA were included in our study. Somatic mutations in all 13 members of the DNAH family of genes were associated with different chemotherapy responses. Compared with patients with wild-type DNAH genes (n = 59), a significantly higher proportion of those with mutations in DNAH genes (n = 73) (55.9% vs 80.8%) responded to chemotherapy (P = 0.002). Moreover, DNAH mutations were correlated with significantly better OS (P = 0.027), chemotherapy-free survival (P = 0.027), fluoropyrimidine-free survival (P = 0.048) and platinum-free survival (P = 0.014). DNAH mutation status was an independent risk factor for OS (P = 0.015), chemotherapy-free survival (P = 0.015) and platinum-free survival (P = 0.011). We identified somatic mutations in 27 (42.2%) of the 64 stage III gastric adenocarcinoma patients receiving fluoropyrimidine-based chemotherapy by targeted exon sequencing with strict screening conditions. In our own cohort, a significantly higher proportion of patients (n = 32) with DNAH mutations than patients with wild-type DNAH genes (n = 32) had a good prognosis (OS > 48 months) (70.4% vs 35.1%) (P = 0.005). Dynein axonemal heavy chain gene mutations contribute positively to chemotherapy sensitivity in gastric cancer patients.

Abstract: A collaborative study was performed in 11 laboratories to validate a DNA hybridization (DNAH) procedure for detection of Salmonella in foods. The DNAH procedure was compared to the standard culture method for detection of Salmonella in 6 foods: ground pepper, soy flour, dry whole egg, milk chocolate, nonfat dry milk, and raw deboned turkey. With the exception of turkey which was naturally contaminated, uninoculated and inoculated samples of each food group were analyzed. Results for the DNAH method were significantly better than for the standard culture method at the 5% probability level for the detection of Salmonella in turkey. There was no significant difference between the methods for the other 5 foods. The method has been adopted official first action.