Background/Aims: Surgical resection or ablation is recommended for the treatment of early hepatocellular carcinoma (HCC), whereas transarterial chemoembolization (TACE) is frequently used in early HCC ineligible for curative resection. We evaluated the clinical effects and safety of radiofrequency ablation (RFA) shortly after TACE in patients with Barcelona clinic liver cancer (BCLC) stage A HCC. Methods: Sixty-seven BCLC stage A HCC patients who failed to achieve complete response to TACE as either a first line treatment and who subsequently received RFA at the Konkuk University Medical Center from January 2005 to December 2017 were included. Evaluation indices included treatment response, overall survival rate, recurrence-free survival, prognostic factors, and procedure-related complications. Results: Median follow-up was 46.9 months. Fifty-four (80.6%) patients were of Child-Pugh class A, and 13 (19.4%) were of class B. Modified UICC stages were I in 10 (14.9%), II in 46 (68.7%), and III in 11 (16.4%) patients. In the 67 study subjects, cumulative recurrence-free survival rates were 86.8%, 55.9% and 29.7% at 1, 3, and 5 years, respectively, and overall survival rates were 100%, 93.4%, and 83.5% at 1, 3, and 5 years, respectively. Tumor size significantly predicted recurrence. No treatment-related death occurred. Conclusions: Combination of RFA was an efficient and safe treatment for BCLC stage A HCC patients that failed to achieve complete response to initial TACE. We suggest TACE plus RFA be considered as a curative option for early HCC patients ineligible for curative resection of RFA.

The spatiotemporal distribution of fish larvae and eggs is fundamental for their reproduction and recruitment in aquatic ecosystems. Here, a metabarcoding strategy was employed as an alternative to a conventional ichthyoplankton survey, which requires a considerable amount of time, labor, and cost. First, a piscine-specific universal primer set (FishU) was designed to amplify the region, flanking the highly conserved mitochondrial 12S and 16S ribosomal genes, and it was optimized for the MiSeq platform. Based on both in silico and in vitro analyses, the newly designed FishU primers outperformed the two previously reported fish-specific universal primer sets (ecoPrimer and MiFish) in taxon coverage, specificity, and accuracy in species identification. The metabarcoding results by FishU primers successfully presented the diversity of ichthyoplankton directly from the zooplankton net samples in the East/Japan Sea, presenting more accurate and plentiful species numbers than those by MiFish primers. Thus, the metabarcoding analysis of ichtyoplankton using the newly designed FishU primers is a promising tool for obtaining useful data to understand the reproduction of fish, such as spawning sites, reproductive periods, population structures, feeding ecology, and diet.

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The mitogenome of an endemic catfish Clarias camerunensis was determined from the Cameroon water. This circular mitogenome was 16,511 bp in length and comprised 13 protein-coding genes, 2 ribosomal RNAs, 22 transfer RNAs, and a single AT-rich control region. The heavy strand accommodates 28 genes, whereas the light strand is constituted by ND6 and eight transfer RNA (tRNA) genes. The C. camerunensis mitochondrial genome is AT biased (56.89%), as showcased in other Clarias species. The comparative analyses revealed that most of the Clarias species have 6 overlapping and 11 intergenic spacer regions. Most of the PCGs were initiated and terminated with the ATG start codon and TAA stop codon, respectively. The tRNAs of C. camerunensis folded into the distinctive cloverleaf secondary structure, except trnS1. The placement of the conserved domains in the control region was similar in all the Clarias species with highly variable nucleotides in CSB-I. Both maximum likelihood and Bayesian-based matrilineal phylogenies distinctly separated all Clarias species into five clades on the basis of their known distributions (South China, Sundaland, Indochina, India, and Africa). The TimeTree analysis revealed that the two major clades (Indo-Africa and Asia) of Clarias species might have diverged during the Paleogene (≈28.66 MYA). Our findings revealed the separation of Indian species (C. dussumieri) and African species (C. camerunensis and Clarias gariepinus) took place during the Paleogene, as well as the South Chinese species (Clarias fuscus) and Sundaland species (Clarias batrachus) splits from the Indochinese species (Clarias macrocephalus) during the Neogene through independent colonization. This pattern of biotic relationships highlights the influence of topography and geological events in determining the evolutionary history of Clarias species. The enrichment of mitogenomic data and multiple nuclear loci from their native range or type locality will confirm the true diversification of Clarias species in African and Asian countries.

The two-spot swimming crab Charybdis bimaculata (Miers, 1886 ) is an important decapod species in the benthic ecosystem of Korean waters. In this study, we determined its complete mitochondrial genome by the combination of NGS analysis using MiSeq platform and PCR-based cloning method. The circular mitochondrial genome of C. bimaculata was 15,714 bp in length in which the standard set of 13 protein-coding genes, 22 tRNA genes, and 2 rRNA genes were encoded. Phylogenic analysis showed that C.bimaculata is most closely related to Charybdis feriata . The complete mitogenome sequence information of C. bimaculata would provide useful data for the conservation of their population in the Pacific ocean.