2,567 research outputs found

    Barriers to mental health service use among distressed family caregivers of lung cancer patients

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    Although family caregivers of patients with lung and other cancers show high rates of psychological distress, they underuse mental health services. This qualitative study aimed to identify barriers to mental health service use among 21 distressed family caregivers of lung cancer patients. Caregivers had not received mental health services during the patient's initial months of care at a comprehensive cancer centre in New York City. Thematic analysis of interview data was framed by Andersen's model of health service use and Corrigan's stigma theory. Results of our analysis expand Andersen's model by providing a description of need variables (e.g. psychiatric symptoms), enabling factors (e.g. finances), and psychosocial factors associated with caregivers' non-use of mental health services. Regarding psychosocial factors, caregivers expressed negative perceptions of mental health professionals and a desire for independent management of emotional concerns. Additionally, caregivers perceived a conflict between mental health service use and the caregiving role (e.g. prioritising the patient's needs). Although caregivers denied stigma associated with service use, their anticipated negative self-perceptions if they were to use services suggest that stigma may have influenced their decision to not seek services. Findings suggest that interventions to improve caregivers' uptake of mental health services should address perceived barriers

    Patterns of DNA Methlyation across the Leptin Core Promoter in Four Diverse Asian and North American Populations

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    DNA methylation is the most widely studied of epigenetic mechanisms, with environmental effects recorded through patterned attachments of methyl groups along the DNA that are capable of modifying gene expression without altering the DNA sequencing. The degree to which these patterns of DNA methylation are heritable, the expected range of normality across populations, and the phenotypic relevance of pattern variation remain unclear. Genes regulating metabolic pathways appear to be vulnerable to ongoing nutritional programming over the life course, as dietary nutrients are significant environmental determinants of DNA methylation, supplying both the methyl groups and energy to generate the methylation process. Here we examine methylation patterns along a region of the metabolic gene leptin (LEP). LEP's putative functions include regulation of energy homeostasis, with its signals affecting energy intake and expenditure, adipogenesis and energy storage, lipid and glucose metabolism, bone metabolism, and reproductive endocrine function. A pattern of differential methylation across CpG sites of the LEP core promoter has been previously identified; however, any consistency of pattern or its phenotypic significance is not fully elucidated among populations. Using DNA extracted from unfractionated white blood cells of peripheral blood samples, our pilot study, divided into two parts, examined the significance of variation in DNA methylation patterns along the leptin core promoter in four populations (phase 1) and used biomarkers reflecting leptin's functional process in two of those populations, western Buryat of Siberia and the Mennonite of central Kansas, to investigate the relevance of the ethnic variation identified in the DNA methylation (phase 2). LEP's core promoter region contains both the binding site for C/EBPĪ± (CCAAT/enhancer binding protein alpha), which tempers the final step in adipocyte maturity and capacity to synthesize leptin, and the TATA motif controlling leptin synthesis. Previous studies report that increased methylation in this region is correlated to decreased gene expression, suggesting tissue-specific methylation variation at this region (Melzner et al. 2002). We hypothesized that evidence of nutritional epigenetic programming would be identified through variation in patterns of DNA methylation and that functional relevance of that variation among populations would be identified through biomarkers that reflect leptin's metabolic signals: serum leptin levels, lipoproteins of the lipid transport system, and anthropometric measures. In phase 1, our combined analyses of 313 individuals documented a distinct and consistent overall pattern of differential DNA methylation across seven CpG sites of LEP core promoter in all ethnicities and both sexes. This pattern replicates those identified in previous studies, suggesting a conserved core promoter region across populations. Phase 2 analyses of two of the four populations (n = 239), correlating methylation at the C/EBPĪ± transcription binding site (TBS) with metabolic and anthropometric biomarkers reflecting LEP roles, showed that stature, which reflects bone growth and remodeling, was significantly and inversely correlated with the percentage of DNA methylation at this site in both sexes. We suggest that variation in DNA methylation along the LEP core promoter plays a substantial role in energy signals affecting both adipogenesis and bone metabolism

    Comparative effects of castration and dehorning in series or concurrent castration and dehorning procedures on stress responses and production in Holstein calves

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    The study objective was to compare serum cortisol as an acute stress measure, chute exit velocity as a behavioral measure, and ADG as an indicator of performance and well-being after castration, dehorning, or concurrent castration/dehorning of calves when performed in parallel and in series. Intact male Holstein calves, 3 to 4 mo, underwent sham handling before 2 procedures performed in series separated by 2 to 3 wk. In Period 1, calves were either dehorned by amputation, surgically castrated, concurrently castrated/dehorned, or served as nonsurgical controls (n = 10/treatment). In Period 2, calves that had been dehorned, castrated, or castrated/dehorned were then castrated, dehorned, or served as nonsurgical controls, respectively. Indicators of distress were measured after all procedures; ADG was assessed for 7 d after each procedure and over the 2 to 3 wk interim. Period 1 cortisol concentrations in dehorned calves were less than in castrated and castrated/dehorned calves at 120 min and from 50 to 240 min, respectively (P \u3c 0.02). There was marginal evidence that cortisol concentrations were greater in castrated/dehorned than castrated calves at 60 min (P = 0.06). Period 2 cortisol concentrations were less in dehorned than castrated calves at 120 min (P = 0.005) but were greater from 360 to 480 min (P \u3c 0.002). The Period 2 cortisol profile of control calves did not differ from the baseline obtained during sham handling, despite the intervening castration/dehorning in Period 1, suggesting that memory did not affect cortisol. The cortisol profile of castrated calves did not differ between periods except at 720 min, when Period 1 concentrations were greater than Period 2 (P = 0.02). Cortisol concentrations of calves dehorned in Period 2 were greater than those dehorned in Period 1 at 20 and 240 to 480 min (P \u3c 0.05). In both periods, castrated calves exited the chute slower than dehorned calves (P \u3c 0.05). The ADG did not differ between surgically treated calves in Period 1; in the interim, the ADG of castrated calves was greater than that of castrated/dehorned calves (difference Ā± SED, 1.4 Ā± 0.6 kg/d; P = 0.03), and in Period 2, the ADG of dehorned calves was less than castrated calves (1.8 Ā± 0.6 kg/d; P = 0.005). Our study supports both the common practice of concurrent castration/dehorning and the sequence of dehorning and castration. Delayed dehorning (vs. delayed castration) appeared to be more acutely stressful and more detrimental to ADG

    On finite Thurston type orderings of braid groups

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    We prove that for any finite Thurston-type ordering <T<_{T} on the braid group\ BnB_{n}, the restriction to the positive braid monoid (Bn+,<T)(B_{n}^{+},<_{T}) is a\ well-ordered set of order type Ļ‰Ļ‰nāˆ’2\omega^{\omega^{n-2}}. The proof uses a combi\ natorial description of the ordering <T<_{T}. Our combinatorial description is \ based on a new normal form for positive braids which we call the \C-normal fo\ rm. It can be seen as a generalization of Burckel's normal form and Dehornoy's \ Ī¦\Phi-normal form (alternating normal form).Comment: 25 pages, 2 figures; proof of Theorem 1 is correcte

    Electronic spectroscopy of trans-azomethane by electron impact

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    The electron impact excitation of trans-azomethane (i.e., trans-dimethyl diazine CH3ā€“Nā€“Nā€“CH3) has been studied by both trapped electron (TE) and differential electron scattering (DES) techniques. The nature of the excited state in each of several transitions has been identified by the energy and angular dependences of the excitation cross section. Two previously unreported singlet-->triplet transitions are observed with maxima at 2.75 and 4.84 eV. Theoretical calculations on the parent compound, trans-diimide (Hā€“N=Nā€“H), suggest that these are the Ļ‡ 1Ag-->1 3Bg (produced by excitation of an electron from an n + molecular orbital to a pi* molecular orbital) and the Ļ‡ 1Ag-->1 3Bu (pi-->pi*) transitions, respectively. The Ļ‡ 1Ag-->1 1Bg (n + -->pi*) transition is observed with a peak at 3.50 eV in the DES studies. A strong peak at 6.01 eV in the TE spectra appears as a weak shoulder in the DES studies and is interpreted as either a symmetry-forbidden or Rydberg-like singlet-->singlet transition. Allowed singlet-->singlet features overlap each other in the transition energy range from 6 to 10 eV. Peaks are seen in the DES spectra at 6.71, 7.8, and 9.5 eV and in the TE spectrum at 8.0 eV. Several significant differences between the TE and the DES spectra are analyzed on the basis of the different nature of the two experiments

    Acute stress impairs sensorimotor gating via the neurosteroid allopregnanolone in the prefrontal cortex

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    Ample evidence indicates that environmental stress impairs information processing, yet the underlying mechanisms remain partially elusive. We showed that, in several rodent models of psychopathology, the neurosteroid allopregnanolone (AP) reduces the prepulse inhibition (PPI) of the startle, a well-validated index of sensorimotor gating. Since this GABAA receptor activator is synthesized in response to acute stress, we hypothesized its participation in stress-induced PPI deficits. Systemic AP administration reduced PPI in C57BL/6J mice and Long-Evans, but not Sprague-Dawley rats. These effects were reversed by isoallopregnanolone (isoAP), an endogenous AP antagonist, and the GABAA receptor antagonist bicuculline and mimicked by AP infusions in the medial prefrontal cortex (mPFC). Building on these findings, we tested AP's implication in the PPI deficits produced by several complementary regimens of acute and short-term stress (footshock, restraint, predator exposure, and sleep deprivation). PPI was reduced by acute footshock, sleep deprivation as well as the combination of restraint and predator exposure in a time- and intensity-dependent fashion. Acute stress increased AP concentrations in the mPFC, and its detrimental effects on PPI were countered by systemic and intra-mPFC administration of isoAP. These results collectively indicate that acute stress impairs PPI by increasing AP content in the mPFC. The confirmation of these mechanisms across distinct animal models and several acute stressors strongly supports the translational value of these findings and warrants future research on the role of AP in information processing
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