162 research outputs found

    Different Host Exploitation Strategies in Two Zebra Mussel-Trematode Systems: Adjustments of Host Life History Traits

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    The zebra mussel is the intermediate host for two digenean trematodes, Phyllodistomum folium and Bucephalus polymorphus, infecting gills and the gonad respectively. Many gray areas exist relating to the host physiological disturbances associated with these infections, and the strategies used by these parasites to exploit their host without killing it. The aim of this study was to examine the host exploitation strategies of these trematodes and the associated host physiological disturbances. We hypothesized that these two parasite species, by infecting two different organs (gills or gonads), do not induce the same physiological changes. Four cellular responses (lysosomal and peroxisomal defence systems, lipidic peroxidation and lipidic reserves) in the host digestive gland were studied by histochemistry and stereology, as well as the energetic reserves available in gonads. Moreover, two indices were calculated related to the reproductive status and the physiological condition of the organisms. Both parasites induced adjustments of zebra mussel life history traits. The host-exploitation strategy adopted by P. folium would occur during a short-term period due to gill deformation, and could be defined as “virulent.” Moreover, this parasite had significant host gender-dependent effects: infected males displayed a slowed-down metabolism and energetic reserves more allocated to growth, whereas females displayed better defences and would allocate more energy to reproduction and maintenance. In contrast, B. polymorphus would be a more “prudent” parasite, exploiting its host during a long-term period through the consumption of reserves allocated to reproduction

    Bioinformatic and Genetic Association Analysis of MicroRNA Target Sites in One-Carbon Metabolism Genes

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    One-carbon metabolism (OCM) is linked to DNA synthesis and methylation, amino acid metabolism and cell proliferation. OCM dysfunction has been associated with increased risk for various diseases, including cancer and neural tube defects. MicroRNAs (miRNAs) are ∼22 nt RNA regulators that have been implicated in a wide array of basic cellular processes, such as differentiation and metabolism. Accordingly, mis-regulation of miRNA expression and/or activity can underlie complex disease etiology. We examined the possibility of OCM regulation by miRNAs. Using computational miRNA target prediction methods and Monte-Carlo based statistical analyses, we identified two candidate miRNA “master regulators” (miR-22 and miR-125) and one candidate pair of “master co-regulators” (miR-344-5p/484 and miR-488) that may influence the expression of a significant number of genes involved in OCM. Interestingly, miR-22 and miR-125 are significantly up-regulated in cells grown under low-folate conditions. In a complementary analysis, we identified 15 single nucleotide polymorphisms (SNPs) that are located within predicted miRNA target sites in OCM genes. We genotyped these 15 SNPs in a population of healthy individuals (age 18–28, n = 2,506) that was previously phenotyped for various serum metabolites related to OCM. Prior to correction for multiple testing, we detected significant associations between TCblR rs9426 and methylmalonic acid (p  =  0.045), total homocysteine levels (tHcy) (p  =  0.033), serum B12 (p < 0.0001), holo transcobalamin (p < 0.0001) and total transcobalamin (p < 0.0001); and between MTHFR rs1537514 and red blood cell folate (p < 0.0001). However, upon further genetic analysis, we determined that in each case, a linked missense SNP is the more likely causative variant. Nonetheless, our Monte-Carlo based in silico simulations suggest that miRNAs could play an important role in the regulation of OCM

    The Evolution of Extracellular Fibrillins and Their Functional Domains

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    Fibrillins constitute the major backbone of multifunctional microfibrils in elastic and non-elastic extracellular matrices, and are known to interact with several binding partners including tropoelastin and integrins. Here, we study the evolution of fibrillin proteins. Following sequence collection from 39 organisms representative of the major evolutionary groups, molecular evolutionary genetics and phylogeny inference software were used to generate a series of evolutionary trees using distance-based and maximum likelihood methods. The resulting trees support the concept of gene duplication as a means of generating the three vertebrate fibrillins. Beginning with a single fibrillin sequence found in invertebrates and jawless fish, a gene duplication event, which coincides with the appearance of elastin, led to the creation of two genes. One of the genes significantly evolved to become the gene for present-day fibrillin-1, while the other underwent evolutionary changes, including a second duplication, to produce present-day fibrillin-2 and fibrillin-3. Detailed analysis of several sequences and domains within the fibrillins reveals distinct similarities and differences across various species. The RGD integrin-binding site in TB4 of all fibrillins is conserved in cephalochordates and vertebrates, while the integrin-binding site within cbEGF18 of fibrillin-3 is a recent evolutionary change. The proline-rich domain in fibrillin-1, glycine-rich domain in fibrillin-2 and proline-/glycine-rich domain in fibrillin-3 are found in all analyzed tetrapod species, whereas it is completely replaced with an EGF-like domain in cnidarians, arthropods, molluscs and urochordates. All collected sequences contain the first 9-cysteine hybrid domain, and the second 8-cysteine hybrid domain with exception of arthropods containing an atypical 10-cysteine hybrid domain 2. Furin cleavage sites within the N- and C-terminal unique domains were found for all analyzed fibrillin sequences, indicating an essential role for processing of the fibrillin pro-proteins. The four cysteines in the unique N-terminus and the two cysteines in the unique C-terminus are also highly conserved

    A systematic review of patient reported factors associated with uptake and completion of cardiovascular lifestyle behaviour change

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    Background: Healthy lifestyles are an important facet of cardiovascular risk management. Unfortunately many individuals fail to engage with lifestyle change programmes. There are many factors that patients report as influencing their decisions about initiating lifestyle change. This is challenging for health care professionals who may lack the skills and time to address a broad range of barriers to lifestyle behaviour. Guidance on which factors to focus on during lifestyle consultations may assist healthcare professionals to hone their skills and knowledge leading to more productive patient interactions with ultimately better uptake of lifestyle behaviour change support. The aim of our study was to clarify which influences reported by patients predict uptake and completion of formal lifestyle change programmes. Methods: A systematic narrative review of quantitative observational studies reporting factors (influences) associated with uptake and completion of lifestyle behaviour change programmes. Quantitative observational studies involving patients at high risk of cardiovascular events were identified through electronic searching and screened against pre-defined selection criteria. Factors were extracted and organised into an existing qualitative framework. Results: 374 factors were extracted from 32 studies. Factors most consistently associated with uptake of lifestyle change related to support from family and friends, transport and other costs, and beliefs about the causes of illness and lifestyle change. Depression and anxiety also appear to influence uptake as well as completion. Many factors show inconsistent patterns with respect to uptake and completion of lifestyle change programmes. Conclusion: There are a small number of factors that consistently appear to influence uptake and completion of cardiovascular lifestyle behaviour change. These factors could be considered during patient consultations to promote a tailored approach to decision making about the most suitable type and level lifestyle behaviour change support

    A European study investigating patterns of transition from home care towards institutional dementia care: the protocol of a RightTimePlaceCare study

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    <p>Abstract</p> <p>Background</p> <p>Health care policies in many countries aim to enable people with dementia to live in their own homes as long as possible. However, at some point during the disease the needs of a significant number of people with dementia cannot be appropriately met at home and institutional care is required. Evidence as to best practice strategies enabling people with dementia to live at home as long as possible and also identifying the right time to trigger admission to a long-term nursing care facility is therefore urgently required. The current paper presents the rationale and methods of a study generating primary data for best-practice development in the transition from home towards institutional nursing care for people with dementia and their informal caregivers. The study has two main objectives: 1) investigate country-specific factors influencing institutionalization and 2) investigate the circumstances of people with dementia and their informal caregivers in eight European countries. Additionally, data for economic evaluation purposes are being collected.</p> <p>Methods/design</p> <p>This paper describes a prospective study, conducted in eight European countries (Estonia, Finland, France, Germany, Netherlands, Sweden, Spain, United Kingdom). A baseline assessment and follow-up measurement after 3 months will be performed. Two groups of people with dementia and their informal caregivers will be included: 1) newly admitted to institutional long-term nursing care facilities; and 2) receiving professional long-term home care, and being at risk for institutionalization. Data will be collected on outcomes for people with dementia (e.g. quality of life, quality of care), informal caregivers (e.g. caregiver burden, quality of life) and costs (e.g. resource utilization). Statistical analyses consist of descriptive and multivariate regression techniques and cross-country comparisons.</p> <p>Discussion</p> <p>The current study, which is part of a large European project 'RightTimePlaceCare', generates primary data on outcomes and costs of long-term nursing care for people with dementia and their informal caregivers, specifically focusing on the transition from home towards institutional care. Together with data collected in three other work packages, knowledge gathered in this study will be used to inform and empower patients, professionals, policy and related decision makers to manage and improve health and social dementia care services.</p

    Molecular Characterization of Cryptosporidium Species and Giardia duodenalis from Symptomatic Cambodian Children

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    Background: In a prospective study, 498 single faecal samples from children aged under 16 years attending an outpatient clinic in the Angkor Hospital for Children, northwest Cambodia, were examined for Cryptosporidium oocysts and Giardia cysts using microscopy and molecular assays. Methodology/Principal Findings: Cryptosporidium oocysts were detected in 2.2% (11/498) of samples using microscopy and in 7.7% (38/498) with molecular tests. Giardia duodenalis cysts were detected in 18.9% (94/498) by microscopy and 27.7% (138/498) by molecular tests; 82% of the positive samples (by either method) were from children aged 1–10 years. Cryptosporidium hominis was the most common species of Cryptosporidium, detected in 13 (34.2%) samples, followed by Cryptosporidium meleagridis in 9 (23.7%), Cryptosporidium parvum in 8 (21.1%), Cryptosporidium canis in 5 (13.2%), and Cryptosporidium suis and Cryptosporidium ubiquitum in one sample each. Cryptosporidium hominis and C. parvum positive samples were subtyped by sequencing the GP60 gene: C. hominis IaA16R6 and C. parvum IIeA7G1 were the most abundant subtypes. Giardia duodenalis was typed using a multiplex real-time PCR targeting assemblages A and B. Assemblage B (106; 76.8% of all Giardia positive samples) was most common followed by A (12.3%) and mixed infections (5.1%). Risk factors associated with Cryptosporidium were malnutrition (AOR 9.63, 95% CI 1.67–55.46), chronic medical diagnoses (AOR 4.51, 95% CI 1.79–11.34) and the presence of birds in the household (AOR 2.99, 95% CI 1.16–7.73); specifically C. hominis (p = 0.03) and C. meleagridis (p<0.001) were associated with the presence of birds. The use of soap was protective against Giardia infection (OR 0.74, 95% CI 0.58–0.95). Conclusions/Significance: This is the first report to describe the different Cryptosporidium species and subtypes and Giardia duodenalis assemblages in Cambodian children. The variety of Cryptosporidium species detected indicates both anthroponotic and zoonotic transmission in this population. Interventions to improve sanitation, increase hand washing after defecation and before preparing food and promote drinking boiled water may reduce the burden of these two parasites

    Spiritual Well-Being and Depression in Patients with Heart Failure

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    BACKGROUND: In patients with chronic heart failure, depression is common and associated with poor quality of life, more frequent hospitalizations, and higher mortality. Spiritual well-being is an important, modifiable coping resource in patients with terminal cancer and is associated with less depression, but little is known about the role of spiritual well-being in patients with heart failure. OBJECTIVE: To identify the relationship between spiritual well-being and depression in patients with heart failure. DESIGN: Cross-sectional study. PARTICIPANTS: Sixty patients aged 60 years or older with New York Heart Association class II–IV heart failure. MEASUREMENTS: Spiritual well-being was measured using the total scale and 2 subscales (meaning/peace, faith) of the Functional Assessment of Chronic Illness Therapy—Spiritual Well-being scale, depression using the Geriatric Depression Scale—Short Form (GDS-SF). RESULTS: The median age of participants was 75 years. Nineteen participants (32%) had clinically significant depression (GDS-SF > 4). Greater spiritual well-being was strongly inversely correlated with depression (Spearman’s correlation −0.55, 95% confidence interval −0.70 to −0.35). In particular, greater meaning/peace was strongly associated with less depression (r = −.60, P < .0001), while faith was only modestly associated (r = −.38, P < .01). In a regression analysis accounting for gender, income, and other risk factors for depression (social support, physical symptoms, and health status), greater spiritual well-being continued to be significantly associated with less depression (P = .05). Between the 2 spiritual well-being subscales, only meaning/peace contributed significantly to this effect (P = .02) and accounted for 7% of the variance in depression. CONCLUSIONS: Among outpatients with heart failure, greater spiritual well-being, particularly meaning/peace, was strongly associated with less depression. Enhancement of patients’ sense of spiritual well-being might reduce or prevent depression and thus improve quality of life and other outcomes in this population
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