Dog‐assisted interventions and outcomes for older adults in residential long‐term care facilities: a systematic review and meta‐analysis

Objective To comprehensively review studies on dog‐assisted interventions (DAIs) among older people in residential long‐term care facilities (RLTCFs) and to provide an overview of their interventions, outcomes and methodological quality. Method We searched 18 electronic databases to identify English articles (published January 2000–December 2019) reporting on well‐defined DAIs targeting older adults (≥65 years) in RLTCF. Data were extracted by two independent reviewers. Descriptive statistics were produced for quantitative studies, with key themes identified among qualitative studies. Where possible, estimates were pooled from randomised controlled trials using random effects meta‐analyses. Results Forty‐three relevant studies (39 quantitative; 4 qualitative) were identified. The majority of quantitative studies were assessed as low‐quality according to the MMAT criteria (n = 26, 67%). Almost half of the quantitative studies (n = 18, 46%) found no significant changes over time or between groups across outcomes measured. The most salient intervention effects included improved social functioning (n = 10), reduced depressive symptoms (n = 6) and loneliness (n = 5). A random‐effects meta‐analysis revealed a medium effect in favour of DAT on reducing depressive or loneliness symptoms (pooled SMD: 0.66, 95%CI 0.21–1.11; I2 = 50.5; five trials), relative to treatment as usual. However, compared to treatment as usual, no overall effect of DAI on activities of daily living was detected (p = .737). Key themes from qualitative studies included (a) animals as effective transitional objects, (b) the therapeutic value of pets and (c) the significance of the care environment and stakeholders in facilitating DAI. Implications for practice The findings of this review indicate that while DAI has value for older people in RLTCF, challenges remain in accurately measuring its impact to provide a stronger evidence‐base. Standardisation of DAI service design, delivery and evaluation is required for future research and practice in providing holistic care for older adults

HIV-infected T cells are migratory vehicles for viral dissemination

After host entry through mucosal surfaces, HIV-1 disseminates to lymphoid tissues to establish a generalized infection of the immune system. The mechanisms by which this virus spreads among permissive target cells locally during early stages of transmission, and systemically during subsequent dissemination are not known1. In vitro studies suggest that formation of virological synapses (VSs) during stable contacts between infected and uninfected T cells greatly increases the efficiency of viral transfer2. It is unclear, however, if T cell contacts are sufficiently stable in vivo to allow for functional synapse formation under the conditions of perpetual cell motility in epithelial3 and lymphoid tissues4. Here, using multiphoton intravital microscopy (MP-IVM), we examined the dynamic behavior of HIV-infected T cells in lymph nodes (LNs) of humanized mice. We found that most productively infected T cells migrated robustly, resulting in their even distribution throughout the LN cortex. A subset of infected cells formed multinucleated syncytia through HIV envelope (Env)-dependent cell fusion. Both uncoordinated motility of syncytia as well as adhesion to CD4+ LN cells led to the formation of long membrane tethers, increasing cell lengths to up to 10 times that of migrating uninfected T cells. Blocking the egress of migratory T cells from LNs into efferent lymph, and thus interrupting T cell recirculation, limited HIV dissemination and strongly reduced plasma viremia. Thus, we have found that HIV-infected T cells are motile, form syncytia, and establish tethering interactions that may facilitate cell-to-cell transmission through VSs. While their migration in LNs spreads infection locally, T cell recirculation through tissues is important for efficient systemic viral spread, suggesting new molecular targets to antagonize HIV infection

Effects of fasting and refeeding on the antioxidant system in cockerels and pullets

The effect of fasting and refeeding on total antioxidant status (TAS), glutathione peroxidase (GSH-Px) activity and concentration of some non-enzymatic antioxidant compounds was studied in cockerels and pullets. Blood was collected before and after 48-h fasting and 24 h after refeeding. In cockerels, fasting resulted in a significant decrease of TAS and uric acid concentration. After refeeding, the concentration of TAS remained significantly lower as compared to the control level. At the same time, blood plasma level of total lipids increased in comparison to the control and post-fasting values. In pullets, fasting resulted in a significant decrease of whole blood haemolysate GSH-Px activity and blood plasma concentrations of albumin and uric acid. Simultaneously, a significant increase in total lipids and cholesterol was obtained. In pullets, refeeding resulted in a further decrease of TAS to undetectable values, a significant decrease of blood plasma cholesterol, and a significant increase of GSH-Px in the whole blood haemolysate and in blood plasma uric acid content. The results indicate that fasting has a negative impact on the antioxidant defence system of the blood, which leads to a reduced resistance to oxidative stress in both cockerels and pullets. However, pullets seem to be more susceptible to fasting-provoked oxidative stress than cockerels

Inflammation-induced IgA(+) cells dismantle anti-liver cancer immunity

The role of adaptive immunity in early cancer development is controversial. Here we show that chronic inflammation and fibrosis in humans and mice with non-alcoholic fatty liver disease is accompanied by accumulation of liver-resident immunoglobulin-A-producing (IgA+) cells. These cells also express programmed death ligand 1 (PD-L1) and interleukin-10, and directly suppress liver cytotoxic CD8+ T lymphocytes, which prevent emergence of hepatocellular carcinoma and express a limited repertoire of T-cell receptors against tumour-associated antigens. Whereas CD8+ T-cell ablation accelerates hepatocellular carcinoma, genetic or pharmacological interference with IgA+ cell generation attenuates liver carcinogenesis and induces cytotoxic T-lymphocyte-mediated regression of established hepatocellular carcinoma. These findings establish the importance of inflammation-induced suppression of cytotoxic CD8+ T-lymphocyte activation as a tumour-promoting mechanism.Shabnam Shalapour, Xue-Jia Lin, Ingmar N. Bastian, John Brain, Alastair D. Burt, Alexander A. Aksenov, Alison F. Vrbanac, Weihua Li, Andres Perkins, Takaji Matsutani, Zhenyu Zhong, Debanjan Dhar, Jose A. Navas-Molina, Jun Xu, Rohit Loomba, Michael Downes, Ruth T. Yu, Ronald M. Evans, Pieter C. Dorrestein, Rob Knight, Christopher Benner, Quentin M. Anstee, Michael Kari