8,909 research outputs found

    Cell-matrix interactions regulate mesenchymal stem cell response to hydrostatic pressure.

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    Both hydrostatic pressure (HP) and cell-matrix interactions have independently been shown to regulate the chondrogenic differentiation of mesenchymal stem cells (MSCs). The objective of this study was to test the hypothesis that the response of MSCs to hydrostatic pressure will depend on the biomaterial within which the cells are encapsulated. Bone-marrow-derived MSCs were seeded into either agarose or fibrin hydrogels and exposed to 10 MPa of cyclic HP (1 Hz, 4 h per day, 5 days per week for 3 weeks) in the presence of either 1 or 10 ng ml(-1) of TGF-β3. Agarose hydrogels were found to support a spherical cellular morphology, while MSCs seeded into fibrin hydrogels attached and spread, with clear stress fiber formation. Hydrogel contraction was also observed in MSC-fibrin constructs. While agarose hydrogels better supported chondrogenesis of MSCs, HP only enhanced sulfated glycosaminoglycan (sGAG) accumulation in fibrin hydrogels, which correlated with a reduction in fibrin contraction. HP also reduced alkaline phosphatase activity in the media for both agarose and fibrin constructs, suggesting that this stimulus plays a role in the maintenance of the chondrogenic phenotype. This study demonstrates that a complex relationship exists between cell-matrix interactions and hydrostatic pressure, which plays a key role in regulating the chondrogenic differentiation of MSCs

    The incidence of healthcare use, ill health and mortality in adults with intellectual disabilities and mealtime support needs

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    This is the final published version. It first appeared at http://onlinelibrary.wiley.com/doi/10.1111/jir.12167/full.Background\ud Adults with intellectual disabilities (ID) experience a wide range of eating, drinking and/or swallowing (EDS) problems, for which they receive diverse mealtime support interventions. Previous research has estimated that dysphagia (difficulty swallowing) affects 8% of all adults with ID and that 15% require some form of mealtime support. People with ID (whether they require mealtime support or not) also experience a greater burden of ill-health and die younger than their peers in the general population with no ID.\ud \ud Methods\ud Using an exploratory, population-based cohort study design, we set out to explore health-related outcomes in adults with ID who receive mealtime support for any eating, drinking or swallowing problem, by establishing the annual incidence of healthcare use, EDS-related ill-health, and all-cause mortality. This study was conducted in two counties in the East of England.\ud \ud Results\ud In 2009, 142 adults with mild to profound ID and a need for any type of mealtime support were recruited for a baseline survey. At follow-up one year later, 127 individuals were alive; eight had died; and seven could not be contacted. Almost all participants had one or more GP consultations each year (85-95%) and, in the first year, 20% reportedly had one or more emergency hospitalisations. Although their annual number of GP visits was broadly comparable to that of the general population, one-fifth of this population?s primary healthcare use was directly attributable to EDS-related ill-health. Respiratory infections were the most common cause of morbidity, and the immediate cause of all eight deaths, while concerns about nutrition and dehydration were surprisingly minor. Our participants had a high annual incidence of death (5%) and, with a standardised mortality ratio of 267, their observed mortality was more than twice that expected in the general population of adults with ID (not selected because of mealtime support for EDS problems).\ud \ud Conclusions\ud All Annual Health Checks now offered to adults with ID should include questions about respiratory infections and EDS functioning, in order to focus attention on EDS problems in this population. This has the potential to reduce life-threatening illness

    The effect of interferon beta-1b treatment on MRI measures of cerebral atrophy in secondary progressive multiple sclerosis.

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    The recently completed European trial of interferon beta-1b (IFN beta -1b) in patients with secondary progressive multiple sclerosis (SP multiple sclerosis) has given an opportunity to assess the impact of treatment on cerebral atrophy using serial MRI. Unenhanced T-1-weighted brain imaging was acquired in a subgroup of 95 patients from five of the European centres; imaging was performed at 6-month intervals from month 0 to month 36. A blinded observer measured cerebral volume on four contiguous 5 mm cerebral hemisphere slices at each time point, using an algorithm with a high level of reproducibility and automation. There was a significant and progressive reduction in cerebral volume in both placebo and treated groups, with a mean reduction of 3.9 and 2.9%, respectively, by month 36 (P = 0.34 between groups). Exploratory subgroup analyses indicated that patients without gadolinium (Gd) enhancement at the baseline had a greater reduction of cerebral volume in the placebo group (mean reduction at month 36: placebo 5.1%, IFN beta -1b 1.8%, P < 0.05) whereas those with Gd-enhancing lesions showed a trend to greater reduction of cerebral volume if the patient was on IFN<beta>-1b (placebo 2.6%, IFN beta -1b, 3.7%; P > 0.05). These results are consistent with ongoing tissue loss in both arms of this study of secondary progressive multiple sclerosis. This finding is concordant with previous observations that disease progression, although delayed, is not halted by IFN beta. The different pattern seen in patients with and without baseline gadolinium enhancement suggests that part of the cerebral volume reduction observed in IFN beta -treated patients may be due to the anti-inflammatory/antioedematous effect of the drug. Longer periods of observation and larger groups of patients may be needed to detect the effects of treatment on cerebral atrophy in this population of patients with advanced disease

    Feasibility and acceptability of breath research in primary care: a prospective, cross-sectional, observational study.

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    OBJECTIVES: To examine the feasibility and acceptability of breath research in primary care. DESIGN: Non-randomised, prospective, mixed-methods cross-sectional observational study. SETTING: Twenty-six urban primary care practices. PARTICIPANTS: 1002 patients aged 18-90 years with gastrointestinal symptoms. MAIN OUTCOME MEASURES: During the first 6 months of the study (phase 1), feasibility of patient enrolment using face-to-face, telephone or SMS-messaging (Short Message Service) enrolment strategies, as well as processes for breath testing at local primary care practices, were evaluated. A mixed-method iterative study design was adopted and outcomes evaluated using weekly Plan-Do-Study-Act cycles, focus groups and general practitioner (GP) questionnaires.During the second 6 months of the study (phase 2), patient and GP acceptability of the breath test and testing process was assessed using questionnaires. In addition a 'single practice' recruitment model was compared with a 'hub and spoke' centralised recruitment model with regards to enrolment ability and patient acceptability.Throughout the study feasibility of the collection of a large number of breath samples by clinical staff over multiple study sites was evaluated and quantified by the analysis of these samples using mass spectrometry. RESULTS: 1002 patients were recruited within 192 sampling days. Both 'single practice' and 'hub and spoke' recruitment models were effective with an average of 5.3 and 4.3 patients accrued per day, respectively. The 'hub and spoke' model with SMS messaging was the most efficient combined method of patient accrual. Acceptability of the test was high among both patients and GPs. The methodology for collection, handling and analysis of breath samples was effective, with 95% of samples meeting quality criteria. CONCLUSIONS: Large-scale breath testing in primary care was feasible and acceptable. This study provides a practical framework to guide the design of Phase III trials examining the performance of breath testing in primary care

    Novel Schizophrenia Risk Gene TCF4 Influences Verbal Learning and Memory Functioning in Schizophrenia Patients

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    Background: Recently, a role of the transcription factor 4 (TCF4) gene in schizophrenia has been reported in a large genome-wide association study. It has been hypothesized that TCF4 affects normal brain development and TCF4 has been related to different forms of neurodevelopmental disorders. Schizophrenia patients exhibit strong impairments of verbal declarative memory (VDM) functions. Thus, we hypothesized that the disease-associated C allele of the rs9960767 polymorphism of the TCF4 gene led to impaired VDM functioning in schizophrenia patients. Method: The TCF4 variant was genotyped in 401 schizophrenia patients. VDM functioning was measured using the Rey Auditory Verbal Learning Test (RAVLT). Results: Carriers of the C allele were less impaired in recognition compared to those carrying the AA genotype (13.76 vs. 13.06; p = 0.049). Moreover, a trend toward higher scores in patients with the risk allele was found for delayed recall (10.24 vs. 9.41; p = 0.088). The TCF4 genotype did not influence intelligence or RAVLT immediate recall or total verbal learning. Conclusion: VDM function is influenced by the TCF4 gene in schizophrenia patients. However, the elevated risk for schizophrenia is not conferred by TCF4-mediated VDM impairment. Copyright (C) 2011 S. Karger AG, Base

    Increasing cell biomass in Saccharomyces cerevisiae increases recombinant protein yield: the use of a respiratory strain as a microbial cell factory

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    <p>Abstract</p> <p>Background</p> <p>Recombinant protein production is universally employed as a solution to obtain the milligram to gram quantities of a given protein required for applications as diverse as structural genomics and biopharmaceutical manufacture. Yeast is a well-established recombinant host cell for these purposes. In this study we wanted to investigate whether our respiratory <it>Saccharomyces cerevisiae </it>strain, TM6*, could be used to enhance the productivity of recombinant proteins over that obtained from corresponding wild type, respiro-fermentative strains when cultured under the same laboratory conditions.</p> <p>Results</p> <p>Here we demonstrate at least a doubling in productivity over wild-type strains for three recombinant membrane proteins and one recombinant soluble protein produced in TM6* cells. In all cases, this was attributed to the improved biomass properties of the strain. The yield profile across the growth curve was also more stable than in a wild-type strain, and was not further improved by lowering culture temperatures. This has the added benefit that improved yields can be attained rapidly at the yeast's optimal growth conditions. Importantly, improved productivity could not be reproduced in wild-type strains by culturing them under glucose fed-batch conditions: despite having achieved very similar biomass yields to those achieved by TM6* cultures, the total volumetric yields were not concomitantly increased. Furthermore, the productivity of TM6* was unaffected by growing cultures in the presence of ethanol. These findings support the unique properties of TM6* as a microbial cell factory.</p> <p>Conclusions</p> <p>The accumulation of biomass in yeast cell factories is not necessarily correlated with a proportional increase in the functional yield of the recombinant protein being produced. The respiratory <it>S. cerevisiae </it>strain reported here is therefore a useful addition to the matrix of production hosts currently available as its improved biomass properties do lead to increased volumetric yields without the need to resort to complex control or cultivation schemes. This is anticipated to be of particular value in the production of challenging targets such as membrane proteins.</p
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