Etiology of Diarrhea in Older Children,Adolescents and Adults: A Systematic Review

Background

Diarrhea is an important cause of morbidity and mortality in all regions of the world and among all ages, yet little is known about the fraction of diarrhea episodes and deaths due to each pathogen.

Methodology/Principal Findings

We conducted a systematic literature review to identify all papers reporting the proportion of diarrhea episodes with positive laboratory tests for at least one pathogen in inpatient, outpatient and community settings that met our inclusion and exclusion criteria. We identified a total of 25,701 papers with possible etiology data and after final screening included 22 papers that met all inclusion and exclusion criteria. Enterotoxigenic Escherichia coli and V. cholerae O1/O139 were the leading causes of hospitalizations. In outpatient settings, Salmonella spp., Shigella spp., and E. histolytica were the most frequently isolated pathogens.

Conclusions/Significance

This is the first systematic review which has considered the relative importance of multiple diarrhea pathogens. The few studies identified suggest that there is a great need for additional prospective studies around the world in these age groups to better understand the burden of disease and the variation by region.     

Natural Experience Modulates the Processing of Older Adult Faces in Young Adults and 3-Year-Old Children

Just like other face dimensions, age influences the way faces are processed by adults as well as by children. However, it remains unclear under what conditions exactly such influence occurs at both ages, in that there is some mixed evidence concerning the presence of a systematic processing advantage for peer faces (own-age bias) across the lifespan. Inconsistency in the results may stem from the fact that the individual’s face representation adapts to represent the most predominant age traits of the faces present in the environment, which is reflective of the individual’s specific living conditions and social experience. In the current study we investigated the processing of younger and older adult faces in two groups of adults (Experiment 1) and two groups of 3-year-old children (Experiment 2) who accumulated different amounts of experience with elderly people. Contact with elderly adults influenced the extent to which both adult and child participants showed greater discrimination abilities and stronger sensitivity to configural/featural cues in younger versus older adult faces, as measured by the size of the inversion effect. In children, the size of the inversion effect for older adult faces was also significantly correlated with the amount of contact with elderly people. These results show that, in both adults and children, visual experience with older adult faces can tune perceptual processing strategies to the point of abolishing the discrimination disadvantage that participants typically manifest for those faces in comparison to younger adult faces.     

Mitochondria are More Resistant to Hypoxic Depolarization in the Newborn than in the Adult Brain

Hypoxic-ischemic brain injury subsequent to asphyxia represents a major cause of morbidity and death in the newborn. The newborn brain has been considered more resistant to hypoxia than the adult brain because of lower energy demand. The mechanisms underlying hypoxic brain injury, in particular the age-related vulnerability, are still only partially understood. The mitochondrial function is pivotal for the function and survival of neurons. Acutely isolated CA1 neurons from neonatal (3-6 days) and adult rats (5-6 weeks) were loaded with Rh 123, and the effect of hypoxia on the inner mitochondrial membrane potential (Delta psi(m)) was compared. During prolonged hypoxia (15 min), Delta psi(m) was lost in a majority of the neonatal neurons (83%) and in all the adult neurons. During hypoxia (5 min) followed by reoxygenation the mitochondria in 23% of the neonatal neurons were completely depolarized, whereas 85% of the adult neurons demonstrated a complete loss of Delta psi(m). In conclusion hippocampal CA1 mitochondria in the newborn rat are more resistant to hypoxic depolarization than in the adult rat.     

Mannose metabolism: More than meets the eye

Mannose is a simple sugar with a complex life. It is a welcome therapy for genetic and acquired human diseases, but it kills honeybees and blinds baby mice. It could cause diabetic complications. Mannose chemistry, metabolism, and metabolomics in cells, tissues and mammals can help explain these multiple systemic effects. Mannose has good, bad or ugly outcomes depending on its steady state levels and metabolic flux. This review describes the role of mannose at cellular level and its impact on organisms.     

More than MAX: Discovering the Myc interactome

Comment on: Agrawal P, et al. Cell Cycle 2010; 9:4908-4921.     

Inflammation and Cognition in Older Adults: Evidence from Taiwan

Inflammation has been linked to clinical cognitive impairment, including Alzheimer’s disease. Less is known, however, about the relationship between inflammation and normal, age-associated cognitive decline. An understanding of the determinants of all types of cognitive decline is important for improving quality of life in an aging world. This study investigated whether biomarkers of inflammation were associated with cognitive function and decline in older Taiwanese adults. Data were from the Taiwan Longitudinal Study of Aging and the Social Environment and Biomarkers of Aging Study. Inflammation was measured in 2000 and 2006 as C-reactive protein, interleukin-6, soluble e-selectin, soluble intercellular adhesion molecule-1, and white blood cell count. Cognition was assessed by 10 cognitive and memory tasks, measured in 2006, 2007, and 2011. Growth curve models were used to examine the relationship between inflammation and cognitive score over this time period. Higher levels of inflammation were associated with lower baseline cognitive scores, but not with longitudinal change in cognitive score. This study did not support a causal link between inflammation and cognitive decline among this older cohort. The observed cross-sectional relationship could reflect a causal relationship that arises earlier in life, or confounding; additional research across the life course is warranted.     

More than nervous: the emerging roles of plexins

Plexins are the receptors for semaphorins, a large family of axon guidance cues. Accordingly, the role of plexins in the development of the nervous system was the first to be acknowledged. However, the expression of plexins is not restricted to neuronal cells, and recent research has been increasingly focused on the roles of plexin-semaphorin signalling outside of the nervous system. During embryogenesis, plexins regulate the development of many organs, including the cardiovascular system, skeleton and kidney. They have also been shown to be involved in immune system functions and tumour progression. Analyses of the plexin signalling in different tissues and cell types have provided new insight to the versatility of plexin interactions with semaphorins and other cell-surface receptors. In this review we try to summarise the current understanding of the roles of plexins in non-neural development and immunity.     

Interactive Video Game Cycling Leads to Higher Energy Expenditure and Is More Enjoyable than Conventional Exercise in Adults

Background

Despite the widely accepted health benefits of regular physical activity, only a small percentage of the population meets the current recommendations. The reasons include a wide use of technology and a lack of enjoyment while exercising. The purpose of this study was to compare the physiological, perceptual and enjoyment responses between a single bout of (I) conventional cycling and (II) interactive cycling video game at a matched workload.

Methods

A cross-sectional study in 34 healthy participants was performed. Initially, participants completed an incremental maximal cycling test to measure peak oxygen uptake and to determine ventilatory threshold. In random order, participants carried out a 30 min interactive cycling trial and a 30 min conventional cycling trial at 55% of peak power output. During the trials, oxygen uptake and energy expenditure were measured by open-circuit spirometry and heart rate was measured by radiotelemetry. RPE and enjoyment were measured every 10 minutes with Borg scale and a modified PACES scale.

Results

Interactive cycling resulted in a significantly greater %V̇O₂Reserve (68.2% ± 9.2% vs 64.7% ± 8.1%), rate of energy expenditure (505.8±75.2 vs 487.4±81.2 j·kg^-1·min^-1), and enjoyment (63.4% ± 17 vs 42% ± 13.6), P<0.05. Participants were working at a higher intensity in relation to the individual’s ventilatory threshold during the interactive cycling video game trial (M = 11.86, SE = 3.08) than during the Conventional cycling trial (M = 7.55, SE = 3.16, t(33) = -2.69, P<0.05, r = .42). No significant differences were found for heart rate reserve (72.5 ± 10.4 vs 71.4±10.1%) and RPE (13.1 ± 1.8 vs 13.2 ± 1.7).

Conclusion

Interactive cycling games can be a valid alternative to conventional exercise as they result in a higher exercise intensity than conventional cycling and a distraction from aversive cognitive and physiological states at and above the ventilatory threshold.     

Dystrophin: More than just the sum of its parts

Dystrophin is one of a number of large cytoskeleton associated proteins that connect between various cytoskeletal elements and often are tethered to the membrane through other transmembrane protein complexes. These cytolinker proteins often provide structure and support to the cells where they are expressed, and mutations in genes encoding these proteins frequently gives rise to disease. Dystrophin is no exception in any of these respects, providing connections between a transmembrane complex known as the dystrophin–glycoprotein complex and the underlying cytoskeleton. The most established connection and possibly the most important is that to F-actin, but more recently evidence has been forthcoming of connections to membrane phospholipids, intermediate filaments and microtubules. Moreover it is becoming increasingly clear that the multiple spectrin-like repeats in the centre of the molecule, that had hitherto been thought to be largely redundant, harbour binding activities that have a significant impact on dystrophin functionality. This functionality is particularly apparent when assessed by the ability to rescue the dystrophic phenotype in mdx mice. This review will focus on the relatively neglected but functionally vital coiled-coil region of dystrophin, highlighting the structural relationships and interactions of the coiled-coil region and providing new insights into the functional role of this region.     

Influence of Perceived Parent and Peer Endorsement on Adolescent Smoking Intentions: Parents Have More Say,But Their Influence Wanes as Kids Get Older

Purpose

The aim of the study is to investigate how adolescents'' perception of parents'' and peers'' smoking approval influences adolescent smoking intention, and how age affects this influence in a Swiss sample of adolescents. To know the influence of age can help to develop specific prevention programs tailored to the age groups needs.

Method

in a cross sectional survey, students aged between 11 and 14 from public and private middle schools in the Italian region of Switzerland (Ticino) answered questions on smoking habits, parents'' and peers'' approval and intention to smoke.

Results

peers'' and parents'' approval significantly influence students'' smoking intention, and students'' age significantly moderates this relation: the effect of parents'' approval decreases for older adolescents, while the effect of peers'' approval increases with age. No difference is found between girls and boys, while non-Swiss are more likely to smoke than Swiss students.

Conclusions

as literature suggests, results evidence the role parents play during early adolescence. Prevention programs targeting parent-child communication in early adolescence for preventing children''s tobacco consumption are strongly supported.     

Pets in the Lives of Older Adults: A Life Course Perspective

This study employed the life course perspective to investigate the convergence of two demographic shifts: the aging of the population and the increase of pet ownership. Specifically, we examined whether pet ownership, the degree of bond with a pet, and reasons for and against pet ownership differed between three age cohorts: the young-old (ages 51–64 years), older adults (ages 65–84), and the oldest-old (ages 85 and over). This study analyzed data from 1,367 respondents of the 2012 wave of the Health and Retirement Study (HRS) using bivariate statistics and multivariate regression models. We found evidence for differences in rates of pet ownership by race, ethnicity, age, number living in household, and whether someone was living with a spouse or partner, but not by gender, education, income, wealth, or health. The bond with a pet did not differ across age cohorts. Companionship was the most common reason for owning a pet across the three age groups, while concern about the resources (e.g., time and work) required of pet ownership was the most common reason for not living with a pet. Results were interpreted at the individual level using the life course perspective’s tenets of timing in lives, linked lives, and human agency, while taking the societal level tenet of historical time and place into account. While rates of pet ownership differed by age cohort, all participants reported a strong bond with their companion animal. Programs and policies can help facilitate these ongoing relationships. The life course perspective provides a useful framework to gain a deeper understanding of pet ownership and the human–animal bond throughout people’s lives.     

More than cell death: caspases and caspase inhibitors on the move

It is becoming clear that "apoptotic" caspases can effect cellular processes other than cell death. A recent paper in Cell points to a novel role of the Drosophila caspase inhibitor DIAP1 as a determinant of cell migration.