RESUMEN
OBJECTIVES: There is a lack of quantitative and objective methods for measuring skin hardness. This study aimed to verify whether SOFTGRAM, a device that can measure elastic modulus using the Hertz elastic contact theory, could be used to evaluate skin hardness in systemic sclerosis (SSc). METHODS: Skin score according to the modified Rodnan total skin thickness score and elastic modulus of the skin using SOFTGRAM were measured for 20 patients with SSc and 20 healthy controls on 8 parts of the body, both of the cheeks, forearms, fingers, and hands. Five observers shared to measure skin score 320 times (40 participants × 8 parts). Elastic modulus was measured 1600 times (40 participants × 8 parts × 5 times each). As an additional examination to compare differences between observers, the skin score of another healthy control was measured 40 times (5 observers × 8 parts). Elastic modulus was measured 200 times (5 observers × 8 parts × 5 times each). RESULTS: There was a significant correlation between elastic modulus and skin score (correlation coefficient=0.67, p<0.001) and a significant difference in elastic modulus (8 parts: healthy controls vs. limited cutaneous SSc vs. diffuse cutaneous SSc: 22.6±15.7 vs. 32.0±27.7 vs. 44.8±39.8, p<0.001). Intraobserver reliabilities were sufficient in 6 out of 7 observers; however, interobserver was less satisfactory. CONCLUSIONS: This study showed the practicality of SOFTGRAM as an accurate measurement method of skin hardness but also revealed points to be improved. More studies are needed to find an accurate measurement method of skin hardness.
RESUMEN
The CRISPR/Cas9 system is now commonly employed for genome editing in various plants such as Arabidopsis, rice and tobacco. In general, in genome editing of the Arabidopsis genome, the SpCas9 and guide RNA genes are introduced into the genome by the floral dip method. Mutations induced in the target sequence by SpCas9 are confirmed after selecting transformants by screening the T1 seed population. The advantage of this method is that genome-edited plants can be isolated easily. However, mutation efficiency in Arabidopsis using SpCas9 is not as high as that achieved in rice and tobacco, which are subjected to a tissue culture step. In this study, we compared four promoters and found that the parsley UBIQITIN promoter is highly active in Arabidopsis meristem tissue. Furthermore, we examined whether a simple heat treatment could improve mutation efficiency in Arabidopsis. Just one heat treatment at 37°C for 24 h increased the mutation efficiency at all four target sites from 3 to 42%, 43 to 62%, 54 to 75% and 89 to 91%, without detectable off-target mutations. We recommend heat treatment of plate-grown plants at 37°C for 24 h as a simple method to increase the efficiency of CRISPR/Cas9-mediated mutagenesis in Arabidopsis.