There is no consensus on the relationship between variations in TP53 mutations and tumor properties in oral squamous cell carcinoma (OSCC). To further the basic research required to eventually develop individualized (order-made) treatments and prognoses for OSCC, we established six human OSCC lines from patients within our department. Together with another nine cell lines derived from donations by other organizations, we determined the TP53 mutation and single nucleotide polymorphism (SNP) of codon 72 in a total of 15 cell lines, and examined in vitro cell invasion activity and anti-cancer drug sensitivity. The missense mutation at codon 248 was most abundant, and was noted in four cell lines, but other diverse mutation variations were also revealed. The cells which expressed the mutated p53 protein (the p53 (+) group) showed slightly higher invasion activity than did the p53 (-) group. In p53 (+) group, the 72R of SNP (72P/R) was higher than the 72P in invasion activity, although the difference was not significant. Surprisingly, an anti-cancer drug sensitivity test with four different types of drugs showed that the p53 (-) group was more resistant in other than CDDP, and that 72R was more sensitive than 72P in the p53 (+) group. To clarify the characteristics of the R248Q mutation, which is the most abundant missense mutation, the gene was introduced with an expression plasmid vector into a TP53 null Saos-2 cell. The transformant of R248Q mutation gained higher activity of invasion, while its anti-cancer drug sensitivity also increased. Our findings suggest that it may be possible to estimate oral cancer cell characteristics and the malignancy level based on differences in the TP53 mutation.

OBJECTIVETo investigate the colony variation in Actinobacillus actinomycetemcomitans (Aa) from rough to smooth and recognize its different morphology during laboratory translations.

METHODSPrimary strains isolated from subgingival plaque of two juvenile periodontitis patients were repeatedly subcultured on agar plates and broth; for broth culture, every generation was translated in broth and on solid medium separately to observe the corresponding morphologies of Aa grow in broth.

RESULTSThree smooth strains of Aa from the broth culture were obtained. The process was about 7-8 generations: colonies changed from a small and adherence phenotype to a bigger and sediment ones and finally the culture supernatant became turbid; the corresponding morphologies grow on agar exhibiting an adherent, small rough colony phenotype which had a star-shaped internal structure converted gradually to a kind of bigger, opaque, nonadherent, smooth phenotype, then the colony extended out from the margin of the colony and finally converted to a flat, almost parent morphology and the same time the star-like inner structure converted to a simpler and smaller type and finally disappeared. We could not get completely smooth variants of Aa from agar.

CONCLUSIONSThe variation in colony morphology of Aa from rough to smooth is a process, in which the colony was gradually wetter and bigger and at the same time gradually lost the inner structure. During this process three colony morphologies at least can be seen, including rough, opaque smooth and almost translucent smooth.

Aggregatibacter actinomycetemcomitans ; genetics ; growth & development ; Cell Division ; genetics ; Child ; Colony Count, Microbial ; Dental Plaque ; microbiology ; Genetic Variation ; Humans ; Periodontitis ; microbiology ; Phenotype ; RNA, Ribosomal, 16S ; genetics ; Species Specificity

Objectives: Safety reports are core components of secure medical systems, but their significance have remained obscure, mostly owing to limited quantitative approaches other than the numbers of reports. In 2005, we developed “management levels” and their equally converted points (p) of scores, which indicated the grades of required correspondences of medical systems. Moreover, products of those scores multiplied by risk levels (equally converted scores), “total scores” were also proposed for weighting harmful events from biphasic aspects; severity of patient damage and the required levels of correspondence as medical systems. In this study, we assessed this scoring system using extensive longitudinal experience.Methods: Risk, management and total scores were retrospectively surveyed between 2012 and 2022 when a consistent reporting system had worked throughout the study period.Results: The aforementioned three scores inconsistently decreased along with a decrease in number of safety reports from 2,445 to 1,194 cases, or 2,069 to 1,052 cases/105 admitted patients (c/pap) in eleven years. Of the scores, the most prominent decrease was found in the management scores from 2,164 to 1,070 points/pap (p/pap). The risk and total scores had decreased even more modestly: from 1,879 to 1,484 p/pap, and 5,470 to 4,007 p/pap, respectively. When compared with the proportion (%) of risk and management levels in 2012, risk level 0 decreased, and risk level 1 and 3a increased in 2022. However, the proportion of management levels did not change during this period.Conclusion: The proposed scoring system showed that the cumulative severity of patient damage did not worsen, or decrease in some years accompanied by decreasing correspondence levels of the medical system, although the numbers of reports also decreased. These findings show the appropriateness of the on-going safety activities of this hospital even when restricted to reported events. However, their effectiveness including unreported events, requires further study.