164 research outputs found
eNOS transfection of adipose-derived stem cells yields bioactive nitric oxide production and improved results in vascular tissue engineering.
This study evaluates the durability of a novel tissue engineered blood vessel (TEBV) created by seeding a natural vascular tissue scaffold (decellularized human saphenous vein allograft) with autologous adipose-derived stem cells (ASC) differentiated into endothelial-like cells. Previous work with this model revealed the graft to be thrombogenic, likely due to inadequate endothelial differentiation as evidenced by minimal production of nitric oxide (NO). To evaluate the importance of NO expression by the seeded cells, we created TEBV using autologous ASC transfected with the endothelial nitric oxide synthase (eNOS) gene to produce NO. We found that transfected ASC produced NO at levels similar to endothelial cell (EC) controls in vitro which was capable of causing vasorelaxation of aortic specimens ex vivo. TEBV (n = 5) created with NO-producing ASC and implanted as interposition grafts within the aorta of rabbits remained patent for two months and demonstrated a non-thrombogenic surface compared to unseeded controls (n = 5). Despite the xenograft nature of the scaffold, the TEBV structure remained well preserved in seeded grafts. In sum, this study demonstrates that upregulation of NO expression within adult stem cells differentiated towards an endothelial-like lineage imparts a non-thrombogenic phenotype and highlights the importance of NO production by cells to be used as endothelial cell substitutes in vascular tissue engineering applications
Neuromuscular responses to mild-muscle damaging eccentric exercise in a low glycogen state.
The aim of this study was to examine the effect of low muscle glycogen on the neuromuscular responses to maximal eccentric contractions. Fourteen healthy men (22±3years) performed single-leg cycling (20min at ∼75% maximal oxygen uptake (V̇O2 max); eight 90 s sprints at a 1:1 work-to-rest ratio (5% decrements from 90% to 55% V̇O2 max until exhaustion) the evening before 100 eccentric (1.57rads(-1)) with reduced (RED) and normal glycogen (NORM). Neuromuscular responses were measured during and up to 48h after with maximal voluntary and involuntary (twitch, 20Hz and 50Hz) isometric contractions. During eccentric contractions, peak torque decreased (RED: -16.1±2.5%; NORM: -6.2±5.1%) and EMG frequency increased according to muscle length. EMG activity decreased for RED only. After eccentric contractions, maximal isometric force was reduced up to 24h for NORM (-13.5±5.8%) and 48h for RED (-7.4±10.9%). Twelve hours after eccentric contractions, twitch force and the 20:50Hz ratio were decreased for RED but not for NORM. Immediate involuntary with prolonged voluntary force loss suggests that reduced glycogen is associated with increased susceptibility to mild muscle-damaging eccentric exercise with contributions of peripheral and central mechanisms to be different during recovery
The s-mote: a versatile heterogeneous multi-radio platform for wireless sensor networks applications
This paper presents a novel architecture and its
implementation for a versatile, miniaturised mote which
can communicate concurrently using a variety of
combinations of ISM bands, has increased processing
capability, and interoperability with mainstream GSM
technology. All these features are integrated in a small
form factor platform. The platform can have many
configurations which could satisfy a variety of
applications’ constraints. To the best of our knowledge, it
is the first integrated platform of this type reported in the literature. The proposed platform opens the way for
enhanced levels of Quality of Service (QoS), with respect to
reliability, availability and latency, in addition to
facilitating interoperability and power reduction
compared to existing platforms. The small form factor also
allows potential of integration with other mobile platforms
including smart phones
Structural relationships for the design of responsive azobenzene-based lyotropic liquid crystals
Dried blood spots: Effects of less than optimal collection, shipping time, heat, and humidity
ObjectivesThis study investigates how factors related to collection, storage, transport time, and environmental conditions affect the quality and accuracy of analyses of dried blood spot (DBS) samples.MethodsData come from the 2016 Health and Retirement Study (HRS) DBS laboratory reports and the HRS merged with the National Climatic Data Center (NCDC) Global Historical Climate Network Daily (NCDC GHCN‐Daily) and the NCDC Local Climatological Data, by zip code. We ran regression models to examine the associations between assay values based on DBS for five analytes (total cholesterol, high‐density lipoprotein (HDL) cholesterol, glycosylated hemoglobin (HbA1c), C‐reactive protein (CRP), and cystatin C) and the characteristics of DBS cards and drops, shipping time, and temperature, and humidity at the time of collection.ResultsWe found cholesterol measures to be sensitive to many factors including small spots, shipping time, high temperature and humidity. Small spots in DBS cards are related to lower values across all analytes. Longer DBS transit time before freezing is associated with lower values of total and HDL cholesterol and cystatin C. Results were similar whether or not venous blood sample values were included in equations.ConclusionsSmall spots, long shipping time, and exposure to high temperature and humidity need to be avoided if possible. Quality of spots and cards and information on shipping time and conditions should be coded with the data to make adjustments in values when necessary. The different results across analytes indicate that results cannot be generalized to all DBS assays.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/162768/2/ajhb23390_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/162768/1/ajhb23390.pd
Fabrication of Localized Surface Plasmon Resonance Fiber Probes Using Ionic Self-Assembled Gold Nanoparticles
An nm-thickness composite gold thin film consisting of gold nanoparticles and polyelectrolytes is fabricated through ionic self-assembled multilayers (ISAM) technique and is deposited on end-faces of optical fibers to construct localized surface plasmon resonance (LSPR) fiber probes. We demonstrate that the LSPR spectrum induced by ISAM gold films can be fine-tuned through the ISAM procedure. We investigate variations of reflection spectra of the probe with respect to the layer-by-layer adsorption of ISAMs onto end-faces of fibers, and study the spectral variation mechanism. Finally, we demonstrated using this fiber probe to detect the biotin-streptavidin bioconjugate pair. ISAM adsorbed on optical fibers potentially provides a simple, fast, robust, and low-cost, platform for LSPR biosensing applications
An addressable packing parameter approach for reversibly tuning the assembly of oligo(aniline)-based supra-amphiphiles
An addressable packing parameter approach was developed for reversibly tuning the self-assembly of oligo(aniline)-based supra-amphiphiles.</p
SPAG5 as a prognostic biomarker and chemotherapy sensitivity predictor in breast cancer: a retrospective, integrated genomic, transcriptomic, and protein analysis
Background: Although the use of proliferation markers/profiles has been recommended when choosing the appropriate systemic-treatment for breast cancer (BC), the best molecular-marker/test that should be used needs to be identified.
Methods: To identify factors that drive proliferation and its associated features in BC an artificial neural network (ANN) based integrative data-mining methodology was applied to three cohorts [(Nottingham-discovery (ND), Uppsala and METABRIC (Molecular Taxonomy of Breast Cancer International Consortium)]. The most prominent genes in the resulting interactome-map were then identified. Given that SPAG5 was associated with many features of proliferation, featured prominently in the interactome-map and has a fundamental role in mitotic-progression,, we hypothesized that it could be a better indicator of proliferation activity. (BC). Subsequently to test if it could provide a more accurate guide for the delivery of systemic therapies in BC, we investigated the clinico-pathological utility of SPAG5: gene copy number aberrations (CNAs); mRNA and protein expression, in over 10,000 BCs. Integrated analysis of SPAG5-gene CNAs, transcript and protein expression was conducted in the ND cohort (n=171) and validated in the METABRIC cohort (n=1980). In addition, the associations of SPAG5 CNAs, transcript and/or protein with BC specific survival (BCSS), disease free survival (DFS) and/or distant relapse free survival (DRFS) were analysed in multiple cohorts including Uppsala (n=249), METABRIC, three-untreated lymph node (LN) negative cohorts (n=684), a combined multicentre clinical data set (n=5439), Nottingham historical early-stage-primary BC (Nottingham-HES-BC; n=1650), Nottingham oestrogen receptor (ER) negative BC (n=697), Nottingham anthracycline-Neoadjuvant-chemotherapy (Nottingham-AC-Neo-ACT; n=200), and MD Anderson Cancer Centre Taxane/anthracycline (MDACC-T/AC-Neo-ACT; n=508) cohorts. The association of SPAG5 transcript and protein expression with pathological response rate (pCR) were also tested in [MDACC-T/AC-Neo-ACT (n=508) and the phase II trial NCT00455533; n=253)] and [Nottingham-AC-Neo-ACT (n=200)] cohorts; respectively.
Findings: SPAG5 gene gain/amplification at the Ch17q11·2 locus was found in 10.4% of BC (206/1980 (; METABRIC) and was reported in 19·4% of PAM50-HER2 (46/237) and 17·8% of PAM50-LumB (87/488). SPAG5-CNA gain/amplification and high SPAG5-transcript and SPAG5-protein were associated with increased risk of death from BC [Uppsala; (HR (CI 95%): 1·50 (1·18-1·92); p=0·00010, METABRIC; (HR (CI 95%): 1·68 (1·40-2·01) p<0·0001), and Nottingham-HSE-BC; (HR (CI 95%): 1·68 (1·32-2·12), p<0·0001); respectively]. Multivariable Cox regression models, including other validated-prognostic factors, (Uppsala: age, size, LN-stage, genomic grade index (GGI), ER, TP53 mutation and MKi67; METABRIC: age, size, LN-stage, histologic-grade, ER, progesterone receptor (PR), human epidermal growth factor receptor 2 (HER2), hormone-therapy, chemotherapy, interaction term of SPAG5 and both chemotherapyy and hormonotherapy; Desmedt-untreated LN- cohort: ER, Nottingham prognostic index (NPI), 76-gene prognostic signature (Veridex) and Adjuvant-Online (AOL); Nottingham-HES-BC: menopausal status, size, LN- stage, histologic-grade, ER, PR, HER2, ki67, hormone-therapy, chemotherapy, interaction term of SPAG5 and both chemotherapy[y and hormonotherapy), showed that high SPAG5-transcript and high SPAG5-protein were associated with shorter BCSS [Uppsala: (HR (CI 95%): 1·62 (1·03-2·53) p=0·036); METABRIC: (HR (CI 95%): 1·27 (1·02-1·58) p=0·034); Desmedt-untreated LN- cohort: (HR (CI 95%): 2·34 (1·24-4·42) p=0·0090), and Nottingham-HES-BC (HR (CI 95%): 1·73 (1·23-2·46) p=0·0020); respectively]. In ER-negative-BC with high SPAG5-protein, administration of anthracycline-adjuvant-chemotherapy had reduced the risk of death by 60% compared to chemotherapy-naive (HR (95% CI): 0·37 (0·20-0·60); p=0·0010). A multivariable Cox regression analysis, which included other validated prognostic factors for chemotherapy (e.g., menopausal status, size, lymph node stage, histologic grade, ER, PR, HER2, Bcl2, chemotherapy, interaction term of SPAG5 and both chemotherapy[y), revealed that SPAG5-transcript+ was independently associated with decreased risk of DRFS after receiving Taxane/anthracycline-Neo-ACT [MDACC-T/AC-Neo-ACT: (HR (CI 95%): 0·68 (0·48-0·97); p=0·0070)]. In multivariable logistic regression analysis, both SPAG5-transcript+ and SPAG5-protein+ and were independent predictors for higher pCR after combination-cytotoxic chemotherapy [MDACC-T/AC-Neo-ACT: (OR (95% CI) 1·71 (1·07-2·74); p=0·024), and Nottingham-AC-Neo-AC: (OR (95% CI): 8·75 (2·42-31); p=0·0010); respectively].
Interpretation: SPAG5 is a novel amplified gene on Ch17q11.2 in PAM50-LumB and PAM-HER2 BC, and its transcript and protein products are independent prognostic and predictive biomarkers, with potential clinical utility as a biomarker for combination cytotoxic chemotherapy sensitivity, especially in ER- BC
How a Diverse Research Ecosystem Has Generated New Rehabilitation Technologies: Review of NIDILRR’s Rehabilitation Engineering Research Centers
Over 50 million United States citizens (1 in 6 people in the US) have a developmental, acquired, or degenerative disability. The average US citizen can expect to live 20% of his or her life with a disability. Rehabilitation technologies play a major role in improving the quality of life for people with a disability, yet widespread and highly challenging needs remain. Within the US, a major effort aimed at the creation and evaluation of rehabilitation technology has been the Rehabilitation Engineering Research Centers (RERCs) sponsored by the National Institute on Disability, Independent Living, and Rehabilitation Research. As envisioned at their conception by a panel of the National Academy of Science in 1970, these centers were intended to take a “total approach to rehabilitation”, combining medicine, engineering, and related science, to improve the quality of life of individuals with a disability. Here, we review the scope, achievements, and ongoing projects of an unbiased sample of 19 currently active or recently terminated RERCs. Specifically, for each center, we briefly explain the needs it targets, summarize key historical advances, identify emerging innovations, and consider future directions. Our assessment from this review is that the RERC program indeed involves a multidisciplinary approach, with 36 professional fields involved, although 70% of research and development staff are in engineering fields, 23% in clinical fields, and only 7% in basic science fields; significantly, 11% of the professional staff have a disability related to their research. We observe that the RERC program has substantially diversified the scope of its work since the 1970’s, addressing more types of disabilities using more technologies, and, in particular, often now focusing on information technologies. RERC work also now often views users as integrated into an interdependent society through technologies that both people with and without disabilities co-use (such as the internet, wireless communication, and architecture). In addition, RERC research has evolved to view users as able at improving outcomes through learning, exercise, and plasticity (rather than being static), which can be optimally timed. We provide examples of rehabilitation technology innovation produced by the RERCs that illustrate this increasingly diversifying scope and evolving perspective. We conclude by discussing growth opportunities and possible future directions of the RERC program
The complex genetics of gait speed:Genome-wide meta-analysis approach
Emerging evidence suggests that the basis for variation in late-life mobility is attributable, in part, to genetic factors, which may become increasingly important with age. Our objective was to systematically assess the contribution of genetic variation to gait speed in older individuals. We conducted a meta-analysis of gait speed GWASs in 31,478 older adults from 17 cohorts of the CHARGE consortium, and validated our results in 2,588 older adults from 4 independent studies. We followed our initial discoveries with network and eQTL analysis of candidate signals in tissues. The meta-analysis resulted in a list of 536 suggestive genome wide significant SNPs in or near 69 genes. Further interrogation with Pathway Analysis placed gait speed as a polygenic complex trait in five major networks. Subsequent eQTL analysis revealed several SNPs significantly associated with the expression of PRSS16, WDSUB1 and PTPRT, which in addition to the meta-analysis and pathway suggested that genetic effects on gait speed may occur through synaptic function and neuronal development pathways. No genome-wide significant signals for gait speed were identified from this moderately large sample of older adults, suggesting that more refined physical function phenotypes will be needed to identify the genetic basis of gait speed in aging
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