Effects of Social Networks and Caregiver Characteristics on Loneliness in Caregivers to Older Adults with Chronic Conditions

Caregivers to older adults with chronic conditions may experience physical and mental health issues, such as depression and loneliness, due to the stressful nature of providing daily care. Loneliness levels also may be affected by caregiving characteristics (e.g., time spent on caregiving per week), as well as differing levels of social support. Yet, few studies have specifically examined the relationship between loneliness, caregiving characteristics and social support in caregivers to older adults with chronic conditions. Understanding the risk factors for loneliness among caregivers may provide insights into ways to improve caregiver well-being. This study aims to investigate differences in loneliness between caregivers and non-caregivers and associations with caregiving and social network characteristics. In this study, participants will include healthy adult caregivers and non-caregivers who will complete a series of measures assessing loneliness, social support, social networks and caregiving characteristics. This information will be used to map social networks, social interaction frequency, and examine relationships with loneliness among caregivers and non-caregivers

Not lesser but Greater fractional anisotropy in adolescents with alcohol use disorders

AbstractObjectiveThe objective of this study is to examine white matter microstructure using diffusion tensor imaging (DTI) in a sample of adolescents with alcohol use disorders (AUD) and no psychiatric or substance co-morbidity.MethodsFifty adolescents with AUD and fifty non-alcohol abusing controls matched on gender and age were studied with DTI, neurocognitive testing, and a clinical assessment that included measures of alcohol use and childhood trauma. Maps of fractional anisotropy (FA) and mean diffusivity (MD) were computed, registered to a common template, and voxel-wise statistical analysis used to assess group differences. Associations between regions of altered WM microstructure and clinical or neurocognitive measures were also assessed.ResultsCompared with controls, adolescent drinkers without co-morbid substance abuse or externalizing disorder, showed 1) no regions of significantly lower FA, 2) increased FA in WM tracts of the limbic system; 3) no MD differences; and 4) within the region of higher FA in AUD, there were no associations between FA and alcohol use, cognition, or trauma.DiscussionThe most important observation of this study is our failure to observe significantly smaller FA in this relatively large alcohol abuse/dependent adolescent sample. Greater FA in the limbic regions observed in this study may index a risk for adolescent AUD instead of a consequence of drinking. Drinking behavior may be reinforced in those with higher FA and perhaps greater myelination in these brain regions involved in reward and reinforcement

Antioxidant, acetylcholinesterase inhibitory activity and cytotoxicity assessment of the crude extracts of Boophane disticha

1. IntroductionAlzheimer’s disease (AD) is the most commonneurodegenerative disease and is characterized bymemory impairment, cognitive dysfunction, behavioraldisturbances and deficits in daily living (Konrath et al,2012). Approaches to enhance cholinergic function inAD have included stimulation of cholinergic receptorsor prolonging the availability of acetylcholine (ACh)released into the neuronal synaptic cleft by inhibitingACh hydrolysis through the use of acetylcholinesterase(AChE) inhibitors (Howes and Houghton, 2003). Tacrinewas the first widely used AChE inhibitor (Summers,2006). Second generation AChE inhibitors with longerhalf-lives than tacrine, such as donepezil, galanthamineand rivastigmine, have since been developed and arecurrently in use (Shah et al, 2008). In addition, severallines of evidence indicate that reactive oxygen speciesare associated with the pathogenesis of AD, as somecellular characteristics of this disease are either causesor effects of oxidative stress (Zhu et al, 2004; Sultana etal, 2006; Konrath et al, 2012). Generally, thephysiological role of antioxidant compounds is toattenuate the oxidation chain reactions by removingfree-radical intermediates (Liu and Nair, 2010). Since alarge amount of evidence demonstrates that oxidativestress is intimately involved in age-relatedneurodegenerative diseases, there have been a numberof studies which have examined the positive effects ofantioxidants in reducing or blocking neuronal deathoccurring in the pathophysiology of these disorders(Ramassamy, 2006). Consequently, the use ofantioxidants has been explored in an attempt to slowAD progression and neuronal degeneration (Howes andHoughton, 2003).Toxicity testing is an essential requirement for thedevelopment of modern pharmaceutical compounds.Medicinal plants are assumed to have low toxicity dueto their long-term consumption by humans and animals(Luseba et al, 2007; Verschaeve and van Staden, 2008;Aremu et al, 2011). However, several studies haveshown that many plants used as food or medicine, havepotential toxic effects (Du Plooy et al, 2001; Barlow andSchlatter, 2010). Almost all known AChE inhibitors haveseveral drawbacks, such as hepatotoxicity, shortduration of biological action, low bioavailability,adverse cholinergic side effects in the periphery andnarrow therapeutic windows (Lee et al, 2011). Somecommon synthetic antioxidants including butylatedhydroxyanisole (BHA) and butylated hydroxytoluene(BHT) have been reported to be toxic (Aremu et al,2011). Therefore, the search for new AChE inhibitorsand antioxidants, particularly from natural products,with low toxicity and higher efficacy continues.Many plants are reputed to have ‘anti-ageing’ or‘memory-enhancing’ effects and are used traditionallyto treat several neurodegenerative diseases (Howes andHoughton, 2003). One such plant, Boophane disticha(L.f.) Herb. belongs to the family Amaryllidaceae. It is anattractive, deciduous bulbous plant with a thickcovering of dry scales above the ground and is widelydistributed in Africa, ranging from Sudan in the north tothe Western Cape Province in the south (Wrinkle,1984). Decoctions of bulb scales are given to sedateviolent, psychotic patients while bulb infusions arereported to be used to treat mental illness (van Wykand Gericke, 2000; Sobiecki, 2002). Bulb decoctions arealso used in the treatment of headaches, abdominalpain, weakness, sharp chest pains and persistentbladder pains, as well as treatment of varicose ulcers,relief of urticaria, and cancer (Botha et al, 2005). Thisstudy was aimed at evaluating the AChE inhibitory andantioxidant activity of the bulbs and roots of B. distichato partially justify its traditional use in treatment ofneurodegenerative diseases. The safety of using thisplant in traditional medicine was also investigated byassessing its toxicity using the MTT and neutral redassays

The physiological consequences of crib-biting in horses in response to an ACTH challenge test

Stereotypies are repetitive and relatively invariant patterns of behavior, which are observed in a wide range of species in captivity. Stereotypic behavior occurs when environmental demands produce a physiological response that, if sustained for an extended period, exceeds the natural physiological regulatory capacity of the organism, particularly in situations that include unpredictability and uncontrollability. One hypothesis is that stereotypic behavior functions to cope with stressful environments, but the existing evidence is contradictory. To address the coping hypothesis of stereotypies, we triggered physiological reactions in 22 horses affected by stereotypic behavior (crib-biters) and 21 non-crib-biters (controls), using an ACTH challenge test. Following administration of an ACTH injection, we measured saliva cortisol every 30 min and heart rate (HR) continuously for a period of 3 h. We did not find any differences in HR or HR variability between the two groups, but crib-biters had significantly higher cortisol responses than controls (mean ± SD: CB, 5.84 ± 2.62 ng/ml, C, 4.76 ± 3.04 ng/ml). Moreover, crib-biters that did not perform the stereotypic behavior during the 3- h test period (Group B) had significantly higher cortisol levels than controls, which was not the case of crib-biters showing stereotypic behavior (Group A) (A, 5.58 ± 2.69 ng/ml; B, 6.44 ± 2.38 ng/ml). Our results suggest that crib-biting is a coping strategy that helps stereotypic individuals to reduce cortisol levels caused by stressful situations. We conclude that preventing stereotypic horses from crib-biting could be an inappropriate strategy to control this abnormal behavior, as it prevents individuals from coping with situations that they perceive as stressful.PostprintPeer reviewe

New Experimental Limit on Photon Hidden-Sector Paraphoton Mixing

We report on the first results of a search for optical-wavelength photons mixing with hypothetical hidden-sector paraphotons in the mass range between 10^-5 and 10^-2 electron volts for a mixing parameter greater than 10^-7. This was a generation-regeneration experiment using the "light shining through a wall" technique in which regenerated photons are searched for downstream of an optical barrier that separates it from an upstream generation region. The new limits presented here are approximately three times more sensitive to this mixing than the best previous measurement. The present results indicate no evidence for photon-paraphoton mixing for the range of parameters investigated.Comment: 9 pages, 3 figure

Early structural brain development in infants exposed to HIV and antiretroviral therapy in utero in a South African birth cohort

INTRODUCTION: There is a growing population of children who are HIV-exposed and uninfected (HEU) with the successful expansion of antiretroviral therapy (ART) use in pregnancy. Children who are HEU are at risk of delayed neurodevelopment; however, there is limited research on early brain growth and maturation. We aimed to investigate the effects of in utero exposure to HIV/ART on brain structure of infants who are HEU compared to HIV-unexposed (HU). METHODS: Magnetic resonance imaging using a T2-weighted sequence was undertaken in a subgroup of infants aged 2–6 weeks enrolled in the Drakenstein Child Health Study birth cohort, South Africa, between 2012 and 2015. Mother–child pairs received antenatal and postnatal HIV testing and ART per local guidelines. We compared subcortical and total grey matter volumes between HEU and HU groups using multivariable linear regression adjusting for infant age, sex, intracranial volume and socio-economic variables. We further assessed associations between brain volumes with maternal CD4 cell count and ART exposure. RESULTS: One hundred forty-six infants (40 HEU; 106 HU) with high-resolution images were included in this analysis (mean age 3 weeks; 50.7% male). All infants who were HEU were exposed to ART (88% maternal triple ART). Infants who were HEU had smaller caudate volumes bilaterally (5.4% reduction, p 0.2). Total grey matter volume was also reduced in infants who were HEU (2.1% reduction, p < 0.05). Exploratory analyses showed that low maternal CD4 cell count (<350 cells/mm3) was associated with decreased infant grey matter volumes. There was no relationship between timing of ART exposure and grey matter volumes. CONCLUSIONS: Lower caudate and total grey matter volumes were found in infants who were HEU compared to HU in the first weeks of life, and maternal immunosuppression was associated with reduced volumes. These findings suggest that antenatal HIV exposure may impact early structural brain development and improved antenatal HIV management may have the potential to optimize neurodevelopmental outcomes of children who are HEU