158 research outputs found
Social isolation, loneliness & older people: The case of Iranians
The purpose of this paper is to study a group of elderly people in relation to social isolation and loneliness in older people and the effects it has on a person's well being. Social isolation and loneliness occurs in people of all ages but may be a particular problem in the older generation. The emphasis of this paper is placed upon social isolation and loneliness of a group of elderly Iranians living in metropolitan Sydney. The results showed that all the elderly participants of this study felt isolated and lonely in Australia. The causes had to do with their level of proficiency in the English language, loss and grief due to leaving their homeland and losing friends, political conflict in the Iranian community and the need for meaningful social support networks
Imaging in diagnosis, monitoring and outcome prediction of large vessel vasculitis: a systematic literature review and meta-analysis informing the 2023 update of the EULAR recommendations
Objectives To update the evidence on imaging for diagnosis, monitoring and outcome prediction in large vessel vasculitis (LVV) to inform the 2023 update of the European Alliance of Associations for Rheumatology recommendations on imaging in LVV.
Methods Systematic literature review (SLR) (2017–2022) including prospective cohort and cross-sectional studies (>20 participants) on diagnostic, monitoring, outcome prediction and technical aspects of LVV imaging. Diagnostic accuracy data were meta-analysed in combination with data from an earlier (2017) SLR.
Results The update retrieved 38 studies, giving a total of 81 studies when combined with the 2017 SLR. For giant cell arteritis (GCA), and taking clinical diagnosis as a reference standard, low risk of bias (RoB) studies yielded pooled sensitivities and specificities (95% CI) of 88% (82% to 92%) and 96% (95% CI 86% to 99%) for ultrasound (n=8 studies), 81% (95% CI 71% to 89%) and 98% (95% CI 89% to 100%) for MRI (n=3) and 76% (95% CI 67% to 83%) and 95% (95% CI 71% to 99%) for fluorodeoxyglucose positron emission tomography (FDG-PET, n=4), respectively. Compared with studies assessing cranial arteries only, low RoB studies with ultrasound assessing both cranial and extracranial arteries revealed a higher sensitivity (93% (95% CI 88% to 96%) vs 80% (95% CI 71% to 87%)) with comparable specificity (94% (95% CI 83% to 98%) vs 97% (95% CI 71% to 100%)). No new studies on diagnostic imaging for Takayasu arteritis (TAK) were found. Some monitoring studies in GCA or TAK reported associations of imaging with clinical signs of inflammation. No evidence was found to determine whether imaging severity might predict worse clinical outcomes.
Conclusion Ultrasound, MRI and FDG-PET revealed a good performance for the diagnosis of GCA. Cranial and extracranial vascular ultrasound had a higher pooled sensitivity with similar specificity compared with limited cranial ultrasound
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Safety and immunogenicity of therapeutic DNA vaccination in individuals treated with antiretroviral therapy during acute/early HIV-1 infection
Background: An effective therapeutic vaccine that could augment immune control of HIV-1 replication may abrogate or delay the need for antiretroviral therapy. AIDS Clinical Trials Group (ACTG) A5187 was a phase I/II, randomized, placebo-controlled, double-blinded trial to evaluate the safety and immunogenicity of an HIV-1 DNA vaccine (VRC-HVDNA 009-00-VP) in subjects treated with antiretroviral therapy during acute/early HIV-1 infection. (clinicaltrials.gov NCT00125099) Methods: Twenty healthy HIV-1 infected subjects who were treated with antiretroviral therapy during acute/early HIV-1 infection and had HIV-1 RNA<50 copies/mL were randomized to receive either vaccine or placebo. The objectives of this study were to evaluate the safety and immunogenicity of the vaccine. Following vaccination, subjects interrupted antiretroviral treatment, and set-point HIV-1 viral loads and CD4 T cell counts were determined 17–23 weeks after treatment discontinuation. Results: Twenty subjects received all scheduled vaccinations and discontinued antiretroviral therapy at week 30. No subject met a primary safety endpoint. No evidence of differences in immunogenicity were detected in subjects receiving vaccine versus placebo. There were also no significant differences in set-point HIV-1 viral loads or CD4 T cell counts following treatment discontinuation. Median set-point HIV-1 viral loads after treatment discontinuation in vaccine and placebo recipients were 3.5 and 3.7 log[sub]10 HIV-1 RNA copies/mL, respectively. Conclusions: The HIV-1 DNA vaccine (VRC-HIVDNA 009-00-VP) was safe but poorly immunogenic in subjects treated with antiretroviral therapy during acute/early HIV-1 infection. Viral set-points were similar between vaccine and placebo recipients following treatment interruption. However, median viral load set-points in both groups were lower than in historical controls, suggesting a possible role for antiretroviral therapy in persons with acute or early HIV-1 infection and supporting the safety of discontinuing treatment in this group. Trial Registration: Clinicaltrials.gov NCT0012509
Multiple emergences of genetically diverse amphibian-infecting chytrids include a globalized hypervirulent recombinant lineage
Batrachochytriumdendrobatidis (Bd) is a globally ubiquitous fungal infection that has emerged to become a primary driver of amphibian biodiversity loss. Despite widespread effort to understand the emergence of this panzootic, the origins of the infection, its patterns of global spread, and principle mode of evolution remain largely unknown. Using comparative population genomics, we discovered three deeply diverged lineages of Bd associated with amphibians. Two of these lineages were found in multiple continents and are associated with known introductions by the amphibian trade.We found that isolates belonging to one clade, the global panzootic lineage (BdGPL) have emerged across at least five continents during the 20th century and are associated with the onset of epizootics in North America, Central America, the Caribbean, Australia, and Europe. The two newly identified divergent lineages, Cape lineage (BdCAPE) and Swiss lineage (BdCH), were found to differ in morphological traits when compared against one another and BdGPL, and we show that BdGPL is hypervirulent. BdGPL uniquely bears the hallmarks of genomic recombination, manifested as extensive intergenomic phylogenetic conflict and patchily distributed heterozygosity. Wepostulate that contact between previously genetically isolated allopatric populations of Bd may have allowed recombination to occur, resulting in the generation, spread, and invasion of the hypervirulent BdGPL leading to contemporary disease-driven losses in amphibian biodiversity.Peer Reviewe
Annihilation-Type Charmless Radiative Decays of B Meson in Non-universal Z^\prime Model
We study charmless pure annihilation type radiative B decays within the QCD
factorization approach. After adding the vertex corrections to the naive
factorization approach, we find that the branching ratios of
, and
within the standard model are at the order of
, and ,
respectively. The smallness of these decays in the standard model makes them
sensitive probes of flavor physics beyond the standard model. To explore their
physics potential, we have estimated the contribution of boson in
the decays. Within the allowed parameter space, the branching ratios of these
decay modes can be enhanced remarkably in the non-universal model:
The branching ratios can reach to for and for the , which are large enough for LHC-b and/or Super B-factories to detect
those channels in near future. Moreover, we also predict large CP asymmetries
in suitable parameter space. The observation of these modes could in turn help
us to constrain the mass within the model.Comment: 13 pages, 8 figure
Rare Decays of \Lambda_b->\Lambda + \gamma and \Lambda_b ->\Lambda + l^{+} l^{-} in the Light-cone Sum Rules
Within the Standard Model, we investigate the weak decays of and with the light-cone
sum rules approach. The higher twist distribution amplitudes of
baryon to the leading conformal spin are included in the sum rules for
transition form factors. Our results indicate that the higher twist
distribution amplitudes almost have no influences on the transition form
factors retaining the heavy quark spin symmetry, while such corrections can
result in significant impacts on the form factors breaking the heavy quark spin
symmetry. Two phenomenological models (COZ and FZOZ) for the wave function of
baryon are also employed in the sum rules for a comparison, which can
give rise to the form factors approximately 5 times larger than that in terms
of conformal expansion. Utilizing the form factors calculated in LCSR, we then
perform a careful study on the decay rate, polarization asymmetry and
forward-backward asymmetry, with respect to the decays of , .Comment: 38 pages, 15 figures, some typos are corrected and more references
are adde
Factors influencing the normalization of CD4+ T-cell count, percentage and CD4+/CD8+ T-cell ratio in HIV-infected patients on long-term suppressive antiretroviral therapy
AbstractWe evaluated factors associated with normalization of the absolute CD4+ T-cell counts, per cent CD4+ T cells and CD4+/CD8+ T-cell ratio. A multicentre observational study was carried out in patients with sustained HIV-RNA <50 copies/mL. Outcomes were: CD4-count >500/mm3 and multiple T-cell marker recovery (MTMR), defined as CD4+ T cells >500/mm3 plus %CD4 T cells >29% plus CD4+/CD8+ T-cell ratio >1. Kaplan-Meier survival analysis and Cox regression analyses to predict odds for achieving outcomes were performed. Three hundred and fifty-two patients were included and followed-up for a median of 4.1 (IQR 2.1–5.9) years, 270 (76.7%) achieving a CD4+ T-cell count >500 cells/mm3 and 197 (56%) achieving MTMR. Using three separate Cox models for both outcomes we demonstrated that independent predictors were: both absolute CD4+ and CD8+ T-cell counts, %CD4+ T cells, a higher CD4+/CD8+ T-cell ratio, and age. A likelihood-ratio test showed significant improvements in fitness for the prediction of either CD4+ >500/mm3 or MTMR by multivariable analysis when the other immune markers at baseline, besides the absolute CD4+ count alone, were considered. In addition to baseline absolute CD4+ T-cell counts, pretreatment %CD4+ T cells and the CD4+/CD8+ T-cell ratio influence recovery of T-cell markers, and their consideration should influence the decision to start antiretroviral therapy. However, owing to the small sample size, further studies are needed to confirm these results in relation to clinical endpoints
Global gene flow releases invasive plants from environmental constraints on genetic diversity
When plants establish outside their native range, their ability to adapt to the new environment is influenced by both demography and dispersal. However, the relative importance of these two factors is poorly understood. To quantify the influence of demography and dispersal on patterns of genetic diversity underlying adaptation, we used data from a globally distributed demographic research network comprising 35 native and 18 nonnative populations of Plantago lanceolata. Species-specific simulation experiments showed that dispersal would dilute demographic influences on genetic diversity at local scales. Populations in the native European range had strong spatial genetic structure associated with geographic distance and precipitation seasonality. In contrast, nonnative populations had weaker spatial genetic structure that was not associated with environmental gradients but with higher within-population genetic diversity. Our findings show that dispersal caused by repeated, long-distance, human-mediated introductions has allowed invasive plant populations to overcome environmental constraints on genetic diversity, even without strong demographic changes. The impact of invasive plants may, therefore, increase with repeated introductions, highlighting the need to constrain future introductions of species even if they already exist in an area
CD4/CD8 Ratio and Cancer Risk among Adults with HIV
Background: Independent of CD4 cell count, a low CD4/CD8 ratio in people with HIV (PWH) is associated with deleterious immune senescence, activation, and inflammation, which may contribute to carcinogenesis and excess cancer risk. We examined whether low CD4/CD8 ratios predicted cancer among PWH in the United States and Canada. Methods: We examined all cancer-free PWH with 1 or more CD4/CD8 values from North American AIDS Cohort Collaboration on Research and Design observational cohorts with validated cancer diagnoses between 1998 and 2016. We evaluated the association between time-lagged CD4/CD8 ratio and risk of specific cancers in multivariable, time-updated Cox proportional hazard models using restricted cubic spines. Models were adjusted for age, sex, race and ethnicity, hepatitis C virus, and time-updated CD4 cell count, HIV RNA, and history of AIDS-defining illness. Results: Among 83 893 PWH, there were 5628 incident cancers, including lung cancer (n = 755), Kaposi sarcoma (n = 501), non-Hodgkin lymphoma (n = 497), and anal cancer (n = 439). The median age at cohort entry was 43 years. The overall median 6-month lagged CD4/CD8 ratio was 0.52 (interquartile range = 0.30-0.82). Compared with a 6-month lagged CD4/CD8 of 0.80, a CD4/CD8 of 0.30 was associated with increased risk of any incident cancer (adjusted hazard ratio = 1.24 [95% confidence interval = 1.14 to 1.35]). The CD4/CD8 ratio was also inversely associated with non-Hodgkin lymphoma, Kaposi sarcoma, lung cancer, anal cancer, and colorectal cancer in adjusted analyses (all 2-sided P <. 05). Results were similar using 12-, 18-, and 24-month lagged CD4/CD8 values. Conclusions: A low CD4/CD8 ratio up to 24 months before cancer diagnosis was independently associated with increased cancer risk in PWH and may serve as a clinical biomarker
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