The aim of this study is to evaluate the reporting quality of animal experiments in Korea using the Animals in Research: Reporting In Vivo Experiments (ARRIVE) guideline developed in 2010 to overcome the reproducibility problem and to encourage compliance with replacement, refinement and reduction of animals in research (3R's principle). We reviewed 50 papers published by a Korean research group from 2013 to 2016 and scored the conformity with the 20-items ARRIVE guideline. The median conformity score was 39.50%. For more precise evaluation, the 20 items were subdivided into 57 sub-items. Among the sub-items, status of experimental animals, housing and husbandry were described under the average level. Microenvironment sub-items, such as enrichment, bedding material, cage type, number of companions, scored under 10%. Although statistical methods used for the studies were given in most publications (84%), sample size calculation and statistical assumption were rarely described. Most publications mentioned the IACUC approval, but only 8% mentioned welfare-related assessments and interventions, and only 4% mentioned any implications of experimental methods or findings for 3R. We may recommend the revision of the present IACUC proposal to collect more detailed information and improving educational program for animal researchers according to the ARRIVE guideline.

The purpose of this paper is to compare the biological research carried out in North Korea with the modern outcomes in the same field, from a historical perspective. In the 1960s, the group led by Bong-Han Kim asserted the existence of a fundamental circulatory system in the human body. Their findings were introduced in five papers as well as in the newspaper Rodong Sinmun. The size of the group, the range of equipment, and their findings expanded gradually, and the final paper on blood cells would be only published one of over sixty papers reported at that time. In the five papers, some unclear and inconsistent contents were found. Meanwhile, in the 2000s, PVS (primo vascular system) researchers have published over one hundred papers to prove the existence of this novel system. Some trends have emerged in approximately sixty papers as follows:The research on the identification of the anatomical and histological characteristics has gradually expanded to encompass the system's own functioning. Also, new visual results (e.g. before and after dyeing, and its comparison with blood clots) and the exploration of possible medical applications (e.g. cancer metastasis channels or stem cells location) have been proposed. However, it is difficult to identify papers which comprehensively represented the elements claimed by Bong-Han Kim's group. In addition, papers have been published more in alternative or Oriental medicine journals than in Western biomedical journals. It seems necessary to report more existence of the system in one laboratory animal and in more influential journals.