Knowledge of cancer risk factors and risk-reduction in high-income countries.

According to the International Public Opinion Survey on Cancer 2020, on average, nearly 1 in 3 individuals in high-income countries (HIC) did not engage in risk reduction. Meanwhile, only 1 in 4 individuals reported being aware that eating red and processed meat was a cancer risk factor. We explored relations between risk-reduction behavior and self-perceived knowledge of cancer risk factors in HIC using data from the survey. The average effect of knowledge, and interaction effects with country and risk factor were estimated using a linear model fit. The model included main and two-way interaction terms between the proportion of respondents who knew about a specific risk factor, and risk factor and country. The overall significance of knowledge impact and interaction terms was tested using type III tests in ANCOVA. Based on our analysis, we found that knowledge of cancer risk factors was positively associated with risk reduction in HIC. Every unit increase in the proportion of the population knowledgeable about a cancer risk factor, on average across risk factors and HIC, significantly increases the proportion of people engaging in risk reduction by approximately 16.91%. A significant interaction effect was found between knowledge and country, but not between knowledge and risk factor. Using respondents' non-response options to represent lack of risk factor knowledge Japan had the largest percentage of individuals lacking knowledge about risk factors as well as the largest percentage of individuals not engaging in risk reduction.

Amyloidosis increase is not attenuated by long-term calorie restriction or related to neuron density in the prefrontal cortex of extremely aged rhesus macaques.

As human lifespan increases and the population ages, diseases of aging such as Alzheimer's disease (AD) are a major cause for concern. Although calorie restriction (CR) as an intervention has been shown to increase healthspan in many species, few studies have examined the effects of CR on brain aging in primates. Using postmortem tissue from a cohort of extremely aged rhesus monkeys (22-44 years old, average age 31.8 years) from a longitudinal CR study, we measured immunohistochemically labeled amyloid beta plaques in Brodmann areas 32 and 46 of the prefrontal cortex, areas that play key roles in cognitive processing, are sensitive to aging and, in humans, are also susceptible to AD pathogenesis. We also evaluated these areas for cortical neuron loss, which has not been observed in younger cohorts of aged monkeys. We found a significant increase in plaque density with age, but this was unaffected by diet. Moreover, there was no change in neuron density with age or treatment. These data suggest that even in the oldest-old rhesus macaques, amyloid beta plaques do not lead to overt neuron loss. Hence, the rhesus macaque serves as a pragmatic animal model for normative human aging but is not a complete model of the neurodegeneration of AD. This model of aging may instead prove most useful for determining how even the oldest monkeys are protected from AD, and this information may therefore yield valuable information for clinical AD treatments.

Mesenchymal derived exosomes enhance recovery of motor function in a monkey model of cortical injury.

BACKGROUND: Exosomes from mesenchymal stromal cells (MSCs) are endosome-derived vesicles that have been shown to enhance functional recovery in rodent models of stroke. OBJECTIVE: Building on these findings, we tested exosomes as a treatment in monkeys with cortical injury. METHODS: After being trained on a task of fine motor function of the hand, monkeys received a cortical injury to the hand representation in primary motor cortex. Twenty-four hours later and again 14 days after injury, monkeys received exosomes or vehicle control. Recovery of motor function was followed for 12 weeks. RESULTS: Compared to monkeys that received vehicle, exosome treated monkeys returned to pre-operative grasp patterns and latency to retrieve a food reward in the first three-five weeks of recovery. CONCLUSIONS: These results provide evidence that in monkeys exosomes delivered after cortical injury enhance recovery of motor function.