Associations between Chewing Difficulty, Subjective Cognitive Decline, and Related Functional Difficulties among Older People without Dementia: Focus on Body Mass Index.

OBJECTIVE: This study aimed to determine whether chewing difficulty is associated with subjective cognitive decline (SCD) and related functional difficulties by body mass index. DESIGN: A population-based cross-sectional study. SETTING AND PARTICIPANTS: A nationwide sample of 54,004 individuals aged ≥65 years from the 2018 Korea Community Health Survey. MEASUREMENTS: SCD and SCD-related functional difficulties were measured using the cognitive decline module of the Behavioral Risk Factor Surveillance System. Chewing difficulty was assessed based on a self-report questionnaire from an oral health-related behaviors interview survey. BMI was calculated from objective values by measuring height and weight through a physical meter. RESULTS: Among the 54,004 individuals, the prevalence of SCD in underweight, overweight, and obesity group was 33.6% (n = 806), 30.3% (n = 9,691), and 28.7% (n=5,632) respectively. Chewing difficulty was associated with SCD and SCD-related functional difficulties. This association was more pronounced in underweight (BMI: <18.5 kg/m2) people [underweight: (odds ratio [OR] = 1.68, 95% confidence interval [CI] 1.48-1.92); normal weight: OR = 1.13, 95% CI 1.04-1.22; obese: OR = 1.15, 95% CI 1.05-1.27]. Similar trends were demonstrated for SCD-related functional difficulties (underweight: OR = 1.53, 95% CI 1.17-2.01; normal weight: OR = 1.36, 95% CI 1.15-1.63; obese: OR = 1.50, 95% CI 1.22-1.86). CONCLUSIONS: Chewing difficulty was associated with SCD and SCD-related functional difficulties in older people. Our results suggest that underweight status may play roles in the associations between chewing difficulty and SCD and SCD-related functional difficulties.

Temporary work and depressive symptoms in South Korean workers.

BACKGROUND: In many countries, including South Korea, labour market changes have led to an increase in unstable, temporary jobs. There is evidence that workers in such jobs may experience poorer mental health than those in more stable employment. AIMS: To investigate the association between temporary employment and depressive symptoms in South Korean workers. METHODS: We analysed data from the 2010-2014 Korean Welfare Panel Study (KOWEPS). Employment type was categorized into workers paid per day of labour (day labourers), those on short-term contracts (fixed-term workers) and permanent workers. The association between employment type and depressive symptoms, measured using the Center for Epidemiological Studies Depression scale (CES-D 11), was examined using the generalized estimating equation model. RESULTS: A total of 3756 workers aged 20-59 were included in the 2010 baseline population. Day labourers had the highest mean CES-D 11 score, followed by fixed-term workers and permanent workers. With the day labourer group as reference, fixed-term workers (ß: -1.5027, P < 0.001) and permanent workers (ß: -2.1848, P < 0.001) showed statistically significant decreases in depression scores. CONCLUSIONS: Compared with day labourers, fixed-term workers and permanent workers had progressively lower depression scores. The findings of this study suggest that mental health inequalities based on employment type exist in South Korea.

Differences in kinematics of single leg squatting between anterior cruciate ligament-injured patients and healthy controls.

Seventy to eighty percent of all anterior cruciate ligament (ACL) injuries are due to non-contact injury mechanisms. It has been reported that the majority of injuries due to single leg landing come from valgus positioning of the lower leg. Preventing valgus positioning during single leg landing is expected to help reduce the number of ACL injuries. We found that many ACL-deficient patients cannot perform stable single leg squatting. Therefore, we performed 3D motion analysis of the single-legged half squat for ACL-injured patients to evaluate its significance as a risk factor for ACL injuries. We evaluated the relative angles between the body, thigh, and lower leg using an electromagnetic device during single leg half squatting performed by 63 ACL-injured patients (32 males, 31 females) the day before ACL reconstruction and by 26 healthy control subjects with no knee problems. The uninjured leg of ACL-injured male subjects demonstrated significantly less external knee rotation than that of the dominant leg of the male control. The uninjured leg of ACL-injured female subjects demonstrated significantly more external hip rotation and knee flexion and less hip flexion than that of the dominant leg of the female control. Comparing injured and uninjured legs, the injured leg of male subjects demonstrated significantly less external knee and hip rotation, less knee flexion, and more knee varus than that of the uninjured leg of male subjects. The injured leg of female subjects demonstrated more knee varus than that of the uninjured leg of female subjects. Regarding gender differences, female subjects demonstrated significantly more external hip rotation and knee valgus than male subjects did in both the injured and uninjured legs (P < 0.05). The current kinematic study exhibited biomechanical characteristics of female ACL-injured subjects compared with that of control groups. Kinematic correction during single leg half squat would reduce ACL reinjury in female ACL-injured subjects.

Synovial fluid-derived mesenchymal stem cells increase after intra-articular ligament injury in humans.

OBJECTIVE: The existence of mesenchymal stem cells (MSCs) in SF was previously reported. However, the behaviour and properties of MSCs derived from SF have not been fully elucidated. METHODS: Human SFs were obtained from 19 knee joints with anterior cruciate ligament injury around the time of reconstruction surgery, and from three healthy volunteers. SF was plated, cultured and examined for colony-forming number, in vitro differentiation, surface epitopes and gene profiles. Also, rabbit synovium-MSCs were injected into the knee joint in a rabbit partial anterior cruciate ligament defect model, and the injected cells were traced. RESULTS: SF-MSCs from IA ligament injury patients were 100 times more in number than those from healthy volunteers. Total colony number was positively correlated with post-injury period. No significant differences were observed among the cells derived from SF around the time of the surgery in relation to surface epitopes and differentiation potentials. Cluster analysis of gene profiles demonstrated that SF-MSCs were more similar to synovium MSCs than bone marrow MSCs. In rabbit experiments, the MSCs injected into the knee in which IA ligament was partially defective were observed more on the defected area than on the intact area of the ligament at 24 h. CONCLUSION: We demonstrated that SF-MSCs, similar to synovium MSCs, increased in number after IA ligament injury and surgery without marked alteration of the properties.

Telomere dysfunction alters the chemotherapeutic profile of transformed cells.

Telomerase inhibition has been touted as a novel cancer-selective therapeutic goal based on the observation of high telomerase levels in most cancers and the importance of telomere maintenance in long-term cellular growth and survival. Here, the impact of telomere dysfunction on chemotherapeutic responses was assessed in normal and neoplastic cells derived from telomerase RNA null (mTERC(-/-)) mice. Telomere dysfunction, rather than telomerase per se, was found to be the principal determinant governing chemosensitivity specifically to agents that induced double-stranded DNA breaks (DSB). Enhanced chemosensitivity in telomere dysfunctional cells was linked to therapy-induced fragmentation and multichromosomal fusions, whereas telomerase reconstitution restored genomic integrity and chemoresistance. Loss of p53 function muted the cytotoxic effects of DSB-inducing agents in cells with telomere dysfunction. Together, these results point to the combined use of DSB-inducing agents and telomere maintenance inhibition as an effective anticancer therapeutic approach particularly in cells with intact p53-dependent checkpoint responses.

Isolation and characterization of beta-galactoside specific lectin from Korean mistletoe (Viscum album var. coloratum) with lactose-BSA-sepharose 4B and changes of lectin conformation.

Lectins and its A- and B-chains from Korean mistletoe (Viscum album var. coloratum) were isolated by affinity chromatography on the Sepharose 4B modified by lactose-BSA conjugate synthesized by reductive amination of ligand (lactose) to epsilon-amino groups of lysine residues of spacer (BSA) after reduction by NaCNBH3. The lactose-BSA conjugate was coupled to Sepharose 4B activated by cyanogen bromide. The molecular weight determined by SDS-PAGE were a 31 kD of A-chain and a 35 kD of B-chain. Amino acid analysis and N-terminal sequencing were performed. The effects of pH, temperature and guanidine chloride on the conformation of the lectin were investigated by measuring its intrinsic fluorescence and compared with its hemagglutinating activities. Blue shift was detected on the acidic pH and there was a close relationship between activities and conformation of the lectin. Under denaturing conditions, the tryptophan emission profile of lectin showed typical denaturational red shift which also correspond to the conformations and activity of lectin.