Stem Cell and Oxidative Stress-Inflammation Cycle

Under a variety of physical and experimental settings, stem cells are able to self-renew and differentiate into specialized adult cells. MSCs (mesenchymal stromal/stem cells) are multipotent stem cells present in a wide range of fetal, embryonic, and adult tissues. They are the progenitors of a variety of specialized cells and are considered a crucial tool in tissue engineering. MSCs, derived from various tissues including cord blood, placenta, bone marrow, and dental tissues, have been extensively examined in tissue repair, immune modulation, etc. Increasing the vitality of MSCs and restoring cellular mechanisms are important factors in treatment success. Oxidative stress is to get harm of cellular molecules such as DNA, proteins, and lipids as a result of overproduction of reactive oxygen species (ROS) and reactive nitrogen species (RNS) in cells and tissues or insufficiency of antioxidant systems that can inactivate them. Oxidative stress has a close link with inflammation as a pathophysiological process. ROS can mediate the expression of proinflammatory genes via intracellular signaling pathways and initiate the chronic inflammatory state. At the same time, inflammatory cells secrete a large number of reactive species that cause increased oxidative stress at sites of inflammation. In inflammatory diseases, the differentiation of stem cells, the regenerative and wound healing process can be affected differently by the increase of oxidative stress. Recent studies have indicated that dental pulp stem cells (DPSCs), as a resource of adult stem cells, are an attractive option for cell therapy in diseases such as neurological diseases, diabetes, cardiological diseases, etc. as well as its treatment potential in pulp inflammation. The future of oxidative stress-inflammation cycle and/or ageing therapies involves selective elimination of senescent cells, also known as senolysis, which prevents various age-related diseases. Most pathologies are implicated on the effects of ageing without exerting undesirable side effects.

Comparison of body mass index range criteria and their association with cognition, functioning and depression: a cross-sectional study in Mexican older adults

BACKGROUND

World population is living longer, demanding adjustments in public health policies. Body mass index (BMI) is widely known and used as a parameter and predictor of health status although an adapted criterion for older adults is usually overlooked. BMI has been extensively analysed in relation to mortality but fewer studies address its association with cognition, functioning and depression in older adults. The present study aimed at 1) comparing BMI distribution according to the ranges proposed by the World Health Organization (WHO) and the United States National Research Council Committee on Diet and Health (CDH), 2) analysing their association with cognitive functioning, physical functioning and depression and 3) analysing a possible, interaction of BMI criteria with sex on the outcome measures.

METHODS

This cross-sectional study included 395 participants recruited by convenience sampling; 283 (71.6%) women and 112 (24.58%) men. Mean age was 74.68 (SD = 8.50, range: 60-98). Outcome measures included the Short Portable Mental State Questionnaire for cognitive status, the Barthel's Index of Activities of Daily Living for physical functioning, and the Geriatric Depression Scale.

RESULTS

WHO criterion classified most cases (65.3%) as overweight, followed by normal weight (32.2%) and underweight (2.5%) whereas CDH criterion considered most (48.1%) as normal weight, and followed by overweight (31.4%) and underweight (20.5%). Analysing cognitive status, independent physical functioning and depression mean scores, significant differences (p ≤ .001) were found when comparing the three weight groups (underweight, normal weight and overweight) using either the WHO- or the CDH criterion. Post-hoc tests revealed that in all comparisons the underweight group scored the lowest in all three outcome measures. According to the CDH criterion, overweight was favourable for females but unfavourable for males regarding cognitive status (interaction F(2,389) = 4.52, p ≤ .01) and independent functioning (interaction F(2,389) = 3.86, p ≤ .05).

CONCLUSIONS

BMI and its associations to relevant outcome measures in the older adults must rely on criteria that take into account the particular features of this population, such as the CDH criterion. Underweight was associated with decremented cognition, less independent physical functioning and more depression. Overweight seemed favourable for women but unfavourable for men.

English Longitudinal Study of Aging: can Internet/E-mail use reduce cognitive decline?

BACKGROUND

Cognitive decline is a major risk factor for disability, dementia, and death. The use of Internet/E-mail, also known as digital literacy, might decrease dementia incidence among the older population. The aim was to investigate whether digital literacy might be associated with decreased cognitive decline in older adulthood.

METHODS

Data from the English Longitudinal Study of Aging cohort with 6,442 participants aged 50-89 years, followed for 8 years, with baseline cognitive testing and four additional time points. The main outcome variable was the relative percentage change in delayed recall from a 10-word-list learning task across five separate measurement points. In addition to digital literacy, socioeconomic variables, including wealth and education, comorbidities, and baseline cognitive function were included in predictive models. The analysis used Generalized Estimating Equations.

RESULTS

Higher education, no functional impairment, fewer depressive symptoms, no diabetes, and Internet/E-mail use predicted better performance in delayed recall.

CONCLUSIONS

Digital literacy may help reduce cognitive decline among persons aged between 50 and 89 years.

Reliability of a Frailty Index Based on the Clinical Assessment of Health Deficits in Male C57BL/6J Mice

We investigated the reliability of a newly developed clinical frailty index (FI) that measures frailty based on deficit accumulation in aging mice. FI scores were measured by two different raters independently in a large cohort (n = 233) of 343-430 day-old male C57BL/6J mice. Inter-rater reliability was evaluated with correlation coefficients, the kappa statistic, and intra-class correlation coefficients (ICC) in three separate groups of mice (n = 45, 50, and 138 mice/group) sequentially over 3 months. After each group was evaluated, descriptions of techniques used to identify health deficits were amended. Mice had comparable overall FI scores regardless of rater (0.213±0.002 vs 0.212±0.002; p = .802), although discordant measures declined as techniques were refined. Correlation coefficients (r (2) values) between raters improved throughout the study and mean kappa values increased (mean ± SEM; 0.621±0.018, 0.764±0.017, and 0.836±0.009 for groups 1, 2, and 3; p < .05). Values for intra-class correlation coefficient also improved from .51 (95% confidence interval = 0.11-.73) to .74 (0.54-0.85) and .77 (0.67-.83). FI scores increased over 3 months (p < .05), but did not differ between raters. These results show a high overall inter-rater reliability when the clinical FI tool is used to assess frailty in a large cohort of mice.