The KCNQ1 gene polymorphism as a shared genetic risk for rheumatoid arthritis and chronic periodontitis in Japanese adults: A pilot case‐control study

1 Background

A number of studies have suggested a bidirectional relationship of periodontitis with rheumatoid arthritis (RA) and type 2 diabetes mellitus (T2DM). However, the genetic factors that underlie these relationships have not been elucidated.

2 Methods

We conducted a multicenter case‐control study that included 185 patients with RA and chronic periodontitis (CP), 149 patients with T2DM and CP, 251 patients with CP, and 130 systemically and periodontally healthy controls from a cohort of Japanese adults to assess the shared genetic risk factors for RA and CP as well as for T2DM and CP. A total of 17 candidate single nucleotide polymorphisms (SNPs) associated with RA, T2DM, and CP were genotyped.

3 Results

Multiple logistic regression analyses revealed that the KCNQ1 rs2237892 was significantly associated with comorbidity of RA and CP (P = 0.005) after adjustment for age, sex, and smoking status. The carriers of the T allele among patients with RA and CP showed significantly higher disease activity scores including 28 joints using C‐reactive protein values than the non‐carriers (P = 0.02), although the age, female percentage, and smoking status were comparable. Other SNPs were not associated with comorbidity of RA and CP, T2DM and CP, or susceptibility to CP.

4 Conclusion

The results of the present pilot study suggest for the first time that the KCNQ1 rs2237892 may constitute a shared genetic risk factor for RA and CP, but not for T2DM and CP in Japanese adults.     

Relationship between masticatory function, dental arch width, and bucco-lingual inclination of the first molars

The aim of this study was to clarify the influence of masticatory function on dental arch forms. We evaluated the relationship between the masticatory movement path and occlusal force (as masticatory function) and the dental arch width and first molar bucco-lingual inclination. The subjects were 60 healthy adult females (mean 23.4 years; S.D. 1.6 years) without previous orthodontic treatment or functional abnormalities in the temporomandibular joint. Furthermore, the subjects were divided into a wide group (W-group) and a narrow group (N-group) based on mean maxillary inter-molar width in Japanese females. The masticatory path was recorded using gnathohexagraph system. Maximum occlusal force was measured using a simple type occlusal force meter. And subjects’ arch width and bucco-lingual inclination of the first molars was measured. W-group showed larger arch width and the first molar was more upright on the buccal side compared with N-group. Furthermore, the lateral component of masticatory movement and maximum occlusal force was large in W-group compared with N-group. In the group which strong occlusal force and grinding type mastication had wide arch width and the mandibular first molars upright on the buccal side.     

Development of amperometric arsine gas sensor using gold-modified diamond electrodes

Amperometric gas sensor of arsine was developed using gold-modified diamond electrodes as the working electrodes. The detection method was conducted in high concentration of H₂SO₄. The reaction was declared based on two oxidation steps, involving oxidation of As³⁻ to As⁰ at mild potential in strong acid, followed by electrochemical oxidation of As⁰ to As³⁺ at gold-based electrodes. Linear calibration curve was observed in the concentration range of 5–50 ppb (r² = 0.985) with detection limit of ∼4.43 ppb (S/N = 3). Current decreasing of measurement was found ∼5.5% for 5 measurements. However, better stability was observed after the 5th measurement, indicated that the sensor could be applied for long time measurement. Investigation to several possible interference gasses, i.e. SO₂, H₂S, NO, NO₂, CO, O₃ and H₂ indicated no significant interference of the gas to arsine measurements.     

3-dimensional composite scaffolds consisting of apatite-PLGA-atelocollagen for bone tissue engineering

We fabricated 3-dimensional scaffolds consisting of biodegradable poly(D, L-lactide-co-glycolic acid)(PLGA)(75/25) with hydroxyapatite particles containing atelocollagen (aAC). The aim of this study was to evaluate this new type of scaffold in regard to its basic properties and biocompatibility. Characterization of the obtained scaffolds was performed to know the porosity, shrinkage, diametral tensile strength, and biocompatibility. Composite scaffolds made of PLGA with hydroxyapatite particles containing atelocollagen (PL-aAC) showed a greater strength and stability than PLGA scaffolds. PL-aAC also exhibited superior performance in terms of cell attachment and proliferation as compared to PLGA, while histological findings showed that PL-aAC had an excellent response toward soft tissues. Our results strongly suggest that PL-aAC is more useful for cell transplantation as compared to PLGA for bone tissue engineering.     

Shoulder and elbow pain in junior high school baseball players: Results of a nationwide survey

BackgroundDespite proposals and guidelines to prevent baseball injuries in young players by societies and organizations, many shoulder and elbow injuries continue to occur among junior high school baseball players. In order to investigate the training conditions of junior high school baseball players and the risk factors for shoulder and elbow pain in the players, we conducted a questionnaire survey among junior high school baseball players throughout the country.MethodsThe questionnaire survey was conducted among junior high school baseball players in September 2016.ResultsA total of 11,134 junior high school baseball players belonging to 495 teams responded to the survey. Among these, 4004 players trained every day of the week and 1151 players played baseball games every month with no off-season. Among 9752 players who did not have shoulder and/or elbow pain in the spring and summer of 2015, 19.2% of players experienced elbow pain over the course of one year, 13.6% of players experienced shoulder pain, and 28.0% complained of shoulder and/or elbow pain. The frequency of elbow pain was more than that of shoulder pain. At risk for shoulder pain were pitchers and catchers and second-year students, while risk factors for elbow pain were playing pitcher and catcher positions, pitching or throwing ≥300 balls per week, playing ≥10 games on average per month and being left-handed.ConclusionRisk factors for shoulder pain were different from those for elbow pain. To prevent elbow pain, coaches should pay attention to pitchers and catchers and left-handed players and not allow players to pitch or throw ≥300 full-power balls per week or participate in ≥10 games per month. They should also pay attention to pitchers and catchers and second-year students to prevent shoulder pain. It is important for coaches to train multiple pitchers and catchers.