Influence of PCR cycle number on microbial diversity analysis through next generation sequencing / 生物工程学报

Using of high throughput sequencing technology to study the microbial diversity in complex samples has become one of the hottest issues in the field of microbial diversity research. In this study, the soil and sheep rumen chyme samples were used to extract DNA, respectively. Then the 25 ng total DNA was used to amplify the 16S rRNA V3 region with 20, 25, 30 PCR cycles, and the final sequencing library was constructed by mixing equal amounts of purified PCR products. Finally, the operational taxonomic unit (OUT) amount, rarefaction curve, microbial number and species were compared through data analysis. It was found that at the same amount of DNA template, the proportion of the community composition was not the best with more numbers of PCR cycle, although the species number was much more. In all, when the PCR cycle number is 25, the number of species and proportion of the community composition were the most optimal both in soil or chyme samples.

Beyond ten cycles of cabazitaxel for castrate-resistant prostate cancer.

Background: There are limited data regarding cabazitaxel use beyond 10 cycles. Patients and Methods: Retrospective analysis of prospectively collected data of patients with metastatic castrate-resistant prostate cancer who received over 10 cycles of cabazitaxel after docetaxel failure. Results: Four patients received between 14 and 27 cycles. Reasons for stopping cabazitaxel were toxicity (2), progression (1) and logistics (1). Two of the three patients with measurable disease attained a partial remission (PR). Three patients continued to have a PSA response after 10 cycles; PSA nadir occurred between 17 and 23 cycles. Other than peripheral neuropathy (PN), all the cabazitaxel-related toxicities occurred after the initial cycles and did not increase cumulatively. Clinically significant neuropathy occurred after 15-17 cycles. The cabazitaxel-induced PN was partially reversible, with improvement from grade 3 to grade 2 after a 3-5-month long drug holiday. Conclusion: Cautiously continuing cabazitaxel until progression or intolerable toxicity may maximize efficacy.