125 research outputs found
Hypoxia-enhanced Blood-Brain Barrier Chip recapitulates human barrier function and shuttling of drugs and antibodies
The high selectivity of the human blood-brain barrier (BBB) restricts delivery of many pharmaceuticals and therapeutic antibodies to the central nervous system. Here, we describe an in vitro microfluidic organ-on-a-chip BBB model lined by induced pluripotent stem cell-derived human brain microvascular endothelium interfaced with primary human brain astrocytes and pericytes that recapitulates the high level of barrier function of the in vivo human BBB for at least one week in culture. The endothelium expresses high levels of tight junction proteins and functional efflux pumps, and it displays selective transcytosis of peptides and antibodies previously observed in vivo. Increased barrier functionality was accomplished using a developmentally-inspired induction protocol that includes a period of differentiation under hypoxic conditions. This enhanced BBB Chip may therefore represent a new in vitro tool for development and validation of delivery systems that transport drugs and therapeutic antibodies across the human BBB
Dietary advice for muscularity, leanness and weight control in Men's Health magazine: a content analysis
Background: The dietary content of advice in men’s lifestyle magazines has not been closely scrutinised.
Methods: We carried out an analysis of such content in all 2009 issues (n = 11) of Men’s Health (MH) focusing on muscularity, leanness and weight control.
Results: Promotion of a mesomorphic body image underpinned advice to affect muscle building and control weight. Diet advice was underpinned by a strong pseudo-scientific discourse, with citation of expert sources widely used to legitimise the information. Frequently multiple dietary components were advocated within one article e.g. fat, omega-3 fatty acids, thiamine, zinc and high-glycaemic index foods. Furthermore advice would cover numerous nutritional effects, e.g. strengthening bones, reducing stress and boosting testosterone, with little contextualisation. The emphasis on attainment of a mesomorphic body image permitted promotion of slimming diets.
Advice to increase calorie and protein intake to augment muscle mass was frequent (183 and 262 references, respectively). Such an anabolic diet was advised in various ways, including consumption of traditional protein foods (217 references) and sports foods (107 references), thereby replicating muscle magazines’ support for nutritional supplements. Although advice to increase consumption of red meat was common (52 references), fish and non-flesh sources of protein (eggs, nuts & pulses, and soy products) together exceeded red meat in number of recommendations (206 references). Advice widely asserted micronutrients and phytochemicals from plant food (161 references) as being important in muscle building. This emphasis diverges from stereotypical gender-based food consumption patterns.
Dietary advice for control of body weight largely replicated that of muscularity, with strong endorsement to consume fruits and vegetables (59 references), diets rich in nuts and pulses and fish (66 references), as well as specific micronutrients and phytochemicals (62 references). Notably there was emphasis on fat-burning, good fats and consumption of single foods, with relatively little mention of dietary restriction.
Conclusions: Despite the widespread use of scientific information to endorse dietary advice, the content, format and scientific basis of dietary content of MH leaves much to be desired. The dietary advice as provided may not be conducive to public health
Racism as a determinant of health: a systematic review and meta-analysis
Despite a growing body of epidemiological evidence in recent years documenting the health impacts of racism, the cumulative evidence base has yet to be synthesized in a comprehensive meta-analysis focused specifically on racism as a determinant of health. This meta-analysis reviewed the literature focusing on the relationship between reported racism and mental and physical health outcomes. Data from 293 studies reported in 333 articles published between 1983 and 2013, and conducted predominately in the U.S., were analysed using random effects models and mean weighted effect sizes. Racism was associated with poorer mental health (negative mental health: r = -.23, 95% CI [-.24,-.21], k = 227; positive mental health: r = -.13, 95% CI [-.16,-.10], k = 113), including depression, anxiety, psychological stress and various other outcomes. Racism was also associated with poorer general health (r = -.13 (95% CI [-.18,-.09], k = 30), and poorer physical health (r = -.09, 95% CI [-.12,-.06], k = 50). Moderation effects were found for some outcomes with regard to study and exposure characteristics. Effect sizes of racism on mental health were stronger in cross-sectional compared with longitudinal data and in non-representative samples compared with representative samples. Age, sex, birthplace and education level did not moderate the effects of racism on health. Ethnicity significantly moderated the effect of racism on negative mental health and physical health: the association between racism and negative mental health was significantly stronger for Asian American and Latino(a) American participants compared with African American participants, and the association between racism and physical health was significantly stronger for Latino(a) American participants compared with African American participants.<br /
Autoregulation in resistance training : addressing the inconsistencies
Autoregulation is a process that is used to manipulate training based primarily on the measurement of an individual's performance or their perceived capability to perform. Despite being established as a training framework since the 1940s, there has been limited systematic research investigating its broad utility. Instead, researchers have focused on disparate practices that can be considered specific examples of the broader autoregulation training framework. A primary limitation of previous research includes inconsistent use of key terminology (e.g., adaptation, readiness, fatigue, and response) and associated ambiguity of how to implement different autoregulation strategies. Crucially, this ambiguity in terminology and failure to provide a holistic overview of autoregulation limits the synthesis of existing research findings and their dissemination to practitioners working in both performance and health contexts. Therefore, the purpose of the current review was threefold: first, we provide a broad overview of various autoregulation strategies and their development in both research and practice whilst highlighting the inconsistencies in definitions and terminology that currently exist. Second, we present an overarching conceptual framework that can be used to generate operational definitions and contextualise autoregulation within broader training theory. Finally, we show how previous definitions of autoregulation fit within the proposed framework and provide specific examples of how common practices may be viewed, highlighting their individual subtleties
Familial influences on the clinical characteristics of major depression: a twin study
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66157/1/j.1600-0447.1992.tb03283.x.pd
Effectiveness of joint mobilisation after cast immobilisation for ankle fracture: a protocol for a randomised controlled trial [ACTRN012605000143628]
BACKGROUND: Passive joint mobilisation is a technique frequently used by physiotherapists to reduce pain, improve joint movement and facilitate a return to activities after injury, but its use after ankle fracture is currently based on limited evidence. The primary aim of this trial is to determine if adding joint mobilisation to a standard exercise programme is effective and cost-effective after cast immobilisation for ankle fracture in adults. METHODS/DESIGN: Ninety participants will be recruited from the physiotherapy departments of three teaching hospitals and randomly allocated to treatment or control groups using a concealed procedure. All participants will perform an exercise programme. Participants in the treatment group will also receive joint mobilisation twice a week for four weeks. Blinded follow-up assessments will be conducted four, 12 and 24 weeks after randomisation. The primary outcome measures will be the Lower Extremity Functional Scale and the Assessment of Quality of Life. Secondary outcomes will include measures of impairments, activity limitation and participation. Data on the use of physiotherapy services and participants' out-of-pocket costs will be collected for the cost-effective and cost-utility analyses. To test the effects of treatment, between-group differences will be examined with analysis of covariance using a regression approach. The primary conclusions will be based on the four-week follow-up data. DISCUSSION: This trial incorporates features known to minimise bias. It uses a pragmatic design to reflect clinical practice and maximise generalisability. Results from this trial will contribute to an evidence-based approach for rehabilitation after ankle fracture
Exercise-induced stress behavior, gut-microbiota-brain axis and diet: a systematic review for athletes
Erythrocytes do not activate purified and platelet soluble guanylate cyclases even in conditions favourable for NO synthesis
PIP3 controls synaptic function by maintaining AMPA receptor clustering at the postsynaptic membrane
Supplementary information is available on the Nature Neuroscience website.Despite their low abundance, phosphoinositides are critical regulators of intracellular signaling and membrane compartmentalization. However, little is known of phosphoinositide function at the postsynaptic membrane. Here we show that continuous synthesis and availability of phosphatidylinositol-(3,4,5)-trisphosphate (PIP3) at the postsynaptic terminal is necessary for sustaining synaptic function in rat hippocampal neurons. This requirement was specific for synaptic, but not extrasynaptic, AMPA receptors, nor for
NMDA receptors. PIP3 downregulation impaired PSD-95 accumulation in spines. Concomitantly, AMPA receptors became more mobile and migrated from the postsynaptic density toward the perisynaptic membrane within the spine, leading to synaptic depression. Notably, these effects were only revealed after prolonged inhibition of PIP3 synthesis or by direct quenching of this phosphoinositide at the postsynaptic cell. Therefore, we conclude that a slow, but constant, turnover of PIP3 at synapses is required for maintaining AMPA receptor clustering and synaptic strength under basal conditions.This work was supported by grants from the US National Institute of Mental Health (J.A.E. and J.R.M.), the Dana Foundation (J.A.E.) and the Spanish Ministry of Science and Innovation (J.A.E.). M.F.-M. and S.K. are supported by postdoctoral contracts, and M.R. by a predoctoral fellowship, from the Spanish Ministry of Science and Innovation.Peer reviewe
The taccalonolides are a novel class of microtubule stabilizers that circumvent clinically relevant taxane resistance mechanisms.
Abstract
Abstract #2142
The taccalonolides are a novel class of microtubule stabilizing agents isolated from the tropical plant Tacca chantrieri. Their unique structure and inability to directly bind to or stabilize tubulin in vitro strongly suggest that the taccalonolides cause microtubule stabilization through a distinct mechanism of action. The ability of four taccalonolides, A, E, B and N, to circumvent multidrug resistance mechanisms associated with taxane resistance was studied. The four taccalonolides were able to overcome multidrug resistance mediated by expression of the P-glycoprotein ATP-binding cassette drug transporter in vitro. Furthermore, the taccalonolides A and E were highly active against tumors in a P-glycoprotein expressing Mam17/ADR murine model of breast cancer that is resistant to both doxorubicin and paclitaxel. In addition to P-glycoprotein, the expression of the βIII isotype of tubulin has also been linked with taxane treatment failure. HeLa cells expressing high levels of βIII-tubulin were resistant to paclitaxel, docetaxel, epothilone B and vinblastine. Interestingly, these βIII-tubulin expressing cells were more sensitive to each of the four taccalonolides than the parental cell line. These data demonstrate that the taccalonolides have advantages over the taxanes in clinically relevant drug resistant cell lines and tumor models. Therefore, the taccalonolides represent a novel family of microtubule stabilizing agents with clinical potential.
Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2142.</jats:p
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