Long-Term Effects of an Internet-Mediated Pedometer-Based Walking Program for Chronic Obstructive Pulmonary Disease: Randomized Controlled Trial

BackgroundRegular physical activity (PA) is recommended for persons with chronic obstructive pulmonary disease (COPD). Interventions that promote PA and sustain long-term adherence to PA are needed.ObjectiveWe examined the effects of an Internet-mediated, pedometer-based walking intervention, called Taking Healthy Steps, at 12 months.MethodsVeterans with COPD (N=239) were randomized in a 2:1 ratio to the intervention or wait-list control. During the first 4 months, participants in the intervention group were instructed to wear the pedometer every day, upload daily step counts at least once a week, and were provided access to a website with four key components: individualized goal setting, iterative feedback, educational and motivational content, and an online community forum. The subsequent 8-month maintenance phase was the same except that participants no longer received new educational content. Participants randomized to the wait-list control group were instructed to wear the pedometer, but they did not receive step-count goals or instructions to increase PA. The primary outcome was health-related quality of life (HRQL) assessed by the St George’s Respiratory Questionnaire Total Score (SGRQ-TS); the secondary outcome was daily step count. Linear mixed-effect models assessed the effect of intervention over time. One participant was excluded from the analysis because he was an outlier. Within the intervention group, we assessed pedometer adherence and website engagement by examining percent of days with valid step-count data, number of log-ins to the website each month, use of the online community forum, and responses to a structured survey.ResultsParticipants were 93.7% male (223/238) with a mean age of 67 (SD 9) years. At 12 months, there were no significant between-group differences in SGRQ-TS or daily step count. Between-group difference in daily step count was maximal and statistically significant at month 4 (P<.001), but approached zero in months 8-12. Within the intervention group, mean 76.7% (SD 29.5) of 366 days had valid step-count data, which decreased over the months of study (P<.001). Mean number of log-ins to the website each month also significantly decreased over the months of study (P<.001). The online community forum was used at least once during the study by 83.8% (129/154) of participants. Responses to questions assessing participants’ goal commitment and intervention engagement were not significantly different at 12 months compared to 4 months.ConclusionsAn Internet-mediated, pedometer-based PA intervention, although efficacious at 4 months, does not maintain improvements in HRQL and daily step counts at 12 months. Waning pedometer adherence and website engagement by the intervention group were observed. Future efforts should focus on improving features of PA interventions to promote long-term behavior change and sustain engagement in PA.ClinicalTrialClinicaltrials.gov {"type":"clinical-trial","attrs":{"text":"NCT01102777","term_id":"NCT01102777"}}NCT01102777; https://clinicaltrials.gov/ct2/show/{"type":"clinical-trial","attrs":{"text":"NCT01102777","term_id":"NCT01102777"}}NCT01102777 (Archived by WebCite at http://www.webcitation.org/6iyNP9KUC)     

Working memory maintenance is sufficient to reduce state anxiety

According to the attentional control theory (ACT) proposed by Eysenck and colleagues, anxiety interferes with cognitive processing by prioritizing bottom‐up attentional processes over top‐down attentional processes, leading to competition for access to limited resources in working memory, particularly the central executive (Eysenck, Derakshan, Santos, & Calvo, 2007 ). However, previous research using the n‐back working memory task suggests that working memory load also reduces state anxiety. Assuming that similar mechanisms underlie the effect of anxiety on cognition, and the effect of cognition on anxiety, one possible implication of the ACT would suggest that the reduction of state anxiety with increasing working memory load is driven by activation of central executive attentional control processes. We tested this hypothesis using the Sternberg working memory paradigm, where maintenance processes can be isolated from central executive processes (Altamura et al., 2007 ; Sternberg, 1966 ). Consistent with the n‐back results, subjects showed decreased state anxiety during the maintenance period of high‐load trials relative to low‐load trials, suggesting that maintenance processes alone are sufficient to achieve this state anxiety reduction. Given that the Sternberg task does not require central executive engagement, these results are not consistent with an implication of the ACT where the cognition/anxiety relationship and anxiety/cognition relationship are mediated by similar central executive mechanisms. Instead, we propose an extension of the ACT such that engaging working memory maintenance suppresses state anxiety in a load‐dependent manner. Furthermore, we hypothesize that the efficacy of this effect may moderate the effect of trait anxiety on cognition.     

Illusory conjunctions in visual short‐term memory: Individual differences in corpus callosum connectivity and splitting attention between the two hemifields

Overloading the capacity of visual attention can result in mistakenly combining the various features of an object, that is, illusory conjunctions. We hypothesize that if the two hemispheres separately process visual information by splitting attention, connectivity of corpus callosum—a brain structure integrating the two hemispheres—would predict the degree of illusory conjunctions. In the current study, we assessed two types of illusory conjunctions using a memory‐scanning paradigm; the features were either presented across the two opposite hemifields or within the same hemifield. Four objects, each with two visual features, were briefly presented together followed by a probe‐recognition and a confidence rating for the recognition accuracy. MRI scans were also obtained. Results indicated that successful recollection during probe recognition was better for across hemifields conjunctions compared to within hemifield conjunctions, lending support to the bilateral advantage of the two hemispheres in visual short‐term memory. Age‐related differences regarding the underlying mechanisms of the bilateral advantage indicated greater reliance on recollection‐based processing in young and on familiarity‐based processing in old. Moreover, the integrity of the posterior corpus callosum was more predictive of opposite hemifield illusory conjunctions compared to within hemifield illusory conjunctions, even after controlling for age. That is, individuals with lesser posterior corpus callosum connectivity had better recognition for objects when their features were recombined from the opposite hemifields than from the same hemifield. This study is the first to investigate the role of the corpus callosum in splitting attention between versus within hemifields.     

Application of diffusional kurtosis imaging to detect occult brain damage in multiple sclerosis and neuromyelitis optica

Multiple sclerosis (MS) and neuromyelitis optica (NMO) are two common types of inflammatory demyelinating disease of the central nervous system. Early distinction of NMO from MS is crucial but quite challenging. In this study, 13 NMO spectrum disorder patients (Expanded Disability Status Scale (EDSS) of 3.0 ± 1.7, ranging from 2 to 6.5; disease duration of 5.3 ± 4.7 years), 17 relapsing–remitting MS patients (EDSS of 2.6 ± 1.4, ranging from 1 to 5.5; disease duration of 7.9 ± 7.8 years) and 18 healthy volunteers were recruited. Diffusional kurtosis imaging was employed to discriminate NMO and MS patients at the early or stable stage from each other, and from healthy volunteers. The presence of alterations in diffusion and diffusional kurtosis metrics in normal‐appearing white matter (NAWM) and diffusely increased mean diffusivity (MD) in the cortical normal‐appearing gray matter (NAGM) favors the diagnosis of MS rather than NMO. Meanwhile, normal diffusivities and kurtosis metrics in all NAWM as well as increases in MD in the frontal and temporal NAGM suggest NMO. Our results suggest that diffusion and diffusional kurtosis metrics may well aid in discriminating the two diseases.     

What Protects Certain Nerves from Stretch Injury?

The human tibial nerves is less prone to injury following joint arthroplasty compared with the peroneal nerves. Besides the anatomical distribution, other features may confer protection from stretch injury. We therefore examined the size, shape and connective tissue distribution for the two nerves. The tibial and peroneal nerves from each side of nine fresh human cadavers we reharvested mid‐thigh. Proximal segments manually stretched 20%–25% were fixed in aldehyde, while the adjacent distal segments were fixed in their natural length. Paraffin sections stained by Masson's trichrome method for connective tissue were examined by light microscopy. Tibial nerves had 2X more fascicles compared with the peroneal, but the axonal content appeared similar. Analysis showed that neither nerve had a significant reduction in cross sectional area of the fascicles following stretch. However, fascicles from stretched tibial nerves become significantly more oval compared with those from unstretched controls and peroneal nerves. Tibial nerves had a greater proportion that was extrafascicular tissue (50‐55%) compared with peroneal nerves (38%–42%). This epineurium was typically adipose tissue. Perineurial thickness in both nerves was directly related to fascicular size. Tibial nerves have several unique histological features associated with size, shape and tissue composition compared with the peroneal nerve. We suggest that more fascicles with their tightly bound perineurium and more robust epineurium afford protection against stretch injury. Mechanical studies should clarify how size and shape contribute to nerve protection and/or neurapraxia. Anat Rec, 299:111–117, 2016. © 2015 Wiley Periodicals, Inc.     

Postpartum psychiatric emergency visits: a nested case-control study

Mental health conditions are one of the most common reasons for postpartum emergency department (ED) visits. Characteristics of women using the ED and their mental health service use before presentation are unknown. We characterized all women in Ontario, Canada (2006–2012), who delivered a live born infant and had a psychiatric ED visit within 1 year postpartum (n?=?8728). We compared those whose ED visit was the first physician mental health contact since delivery to those who had accessed mental health services on specific indicators of marginalization hypothesized to be associated with lower likelihood of mental health contact prior to the ED visit. For 60.4 % of women, this was the first physician mental health contact since delivery. The majority were presenting with a mood or anxiety disorder, and only 13.6 % required hospital admission. These women were more likely to have material deprivation and residential instability than women with contact (Q5 vs. Q1 aORs 1.30, 95 % CI 1.12–1.50; 1.17, 95 % CI 1.01–1.36), to live in rural vs. urban areas (aOR 1.58, 95 % CI 1.38–1.80), and to be low vs. high income quintile (aOR 1.18, 95 % CI 1.01–1.38). The frequent use of ED services as the first point of contact for mental health concerns suggests that interventions to improve timely and equitable access to effective outpatient postpartum mental health care are needed. Marginalized women are at particularly high risk of not having accessed outpatient services prior to an ED visit, and therefore, future research and interventions will specifically need to consider the needs of this group.     

A founder mutation (R254X) of SLC22A5 (OCTN2) in Chinese primary carnitine deficiency patients

Mutations in the SLC22A5 gene, which encodes for the plasma membrane carnitine transporter OCTN2, cause primary carnitine deficiency (PCD). After our first report of OCTN2 mutations in Chinese, three more Chinese PCD patients were identified. The parents of these families were non-consanguineous and these families were unrelated. Two novel truncating mutations were found: R254X, a single-base mutation at cDNA position 981 (c.981C>T); and Y387X (c.1382T>G). Two probands, one each from Taiwan and Macau, were homozygous for R254X. The other proband from Taiwan carried both R254X and Y387X. Two additional heterozygote carriers of R254X were also identified among 250 control samples, while none was detected for Y387X. The population carrier rate for R254X would be about 1 in 125. Haplotypes of R254X alleles were examined and patients homozygous for R254X were also homozygous for the same haplotype of intragenic and microsatellites markers. Analysis of population frequencies of haplotypes revealed that the chance of 4 chromosomes having arisen as independent events was 0.016. We conclude that R254X is probably a founder mutation in Chinese. Other previously reported mutations found in the Japanese population were also screening in 250 control samples but no carrier was identified, indicating that they were either very rare or not present in Southern Chinese.     

Maternal asthma,infant feeding,and the risk of asthma in childhood

Controversy surrounds the issue of whether children with asthmatic mothers should be breast-fed. The aim of this study was to investigate whether maternal asthma status alters the association between asthma and breast-feeding. In a cohort study of 2602 West Australian children enrolled before birth and followed prospectively, we collected data on method of infant feeding, maternal asthma (as reported by parental questionnaire), atopy (as measured by skin prick test), and current asthma (defined as a physician's diagnosis of asthma and wheeze in the last year) at 6 years of age. The risk of childhood asthma increased if exclusive breast-feeding was stopped (other milk was introduced) before 4 months (odds ratio, 1.28; 95% CI, 1.01-1.62; P =.038), and this risk was not altered by atopy or maternal asthma status. After adjusting for covariates, exclusive breast-feeding for less than 4 months was a significant risk factor for current asthma (odds ratio, 1.35; 95% CI, 1.00-1.82; P =.049). There was no formal statistical interaction between breast-feeding and maternal asthma status (P =.970). In this study maternal asthma status did not modify the association between asthma and breast-feeding duration. We recommend that infants with or without a maternal history of asthma be exclusively breast-fed for 4 months and beyond.     

P59(fyn) is upregulated in anergic CD8+ T cells

The ultimate goal in clinical transplantation is achievement of graft tolerance. Despite long-term immunosuppression, alloantigens on transplants elicit alloresponses that can initiate organ rejection. Acute rejection is mediated by CD8(+) cytotoxic T cells, whereas chronic rejection is a result of many factors including non-immunological events. The aim of this study was to examine the molecular requirements of T cell anergy, a cellular state that is an integral component of tolerance in vivo. In vitro, the tolerant state is usually best represented by T cell anergy, which is defined by loss of the ability of T cells to produce and secrete interleukin-2 upon restimulation. In the literature, molecular changes in anergic CD4(+) T cells have been studied in great detail, but only little is known about functional and biochemical characteristics of anergic CD8(+) T lymphocytes. In this study, we demonstrate, that CD8(+) T cells are rendered anergic by TCR stimulation without costimulation. They exhibit impaired interleukin-2 production and tyrosine-phosphorylation, but markedly upregulated p59(fyn) expression, which could be shown to be an early event during anergization. Anergic CD8(+) T lymphocytes show elevated surface expression of early activation markers as well as costimulatory molecules, especially that of CTLA4. These results, are an important component for the discovery of potential molecular targets, which contribute to the development and maintenance of tolerance.