110 research outputs found
Alien Registration- Moreau, Elizabeth E. (Portland, Cumberland County)
https://digitalmaine.com/alien_docs/21867/thumbnail.jp
Application of quality by design tools to upstream processing of platelet precursor cells to enable in vitro manufacture of blood products
Annually 4.5 million platelet units are transfused in Europe and the United States. These are obtained solely from allogeneic donations and have a shelf life of 5-7 days. To address the corresponding supply challenge, Moreau et al.1 devised a novel process for producing megakaryocytes (MKs, the platelet precursor cell) in vitro. A transcription-factor driven, forward-programming (FOP) approach converts human pluripotent stem cells into MKs. This strategy has the unique advantage of generating high yields of pure MKs in chemically defined medium which could lead to the production of a consistent, reliable supply of platelets which overcomes the logistical, financial and biosafety challenges for health organisations worldwide. Here we follow a Quality by Design (QbD) approach to enable improvements to the upstream processing of FOPMKs. Firstly, we created a process flow diagram for production of in vitro platelets for transfusion, which segregated processes into individual unit operations for control and optimisation. Next, we developed a Quality Target Product Profile (QTPP) and identified Critical Quality Attributes (CQAs) for each stage. We conducted a range of experiments utilising Design of Experiments (DOE) and mechanistic modelling2 tools to link Critical Process Parameters (CPPs) to CQAs. For adherent culture, we identified a productivity limit related to surface area available for growth and a cell loss phase which was dependent on cell seeding density, RhoK inhibitor usage and seed density. Using suspension cultures of FOPMK. We noted that TPO and Doxycycline concentration were CPPs as these impacted cell net growth rate and phenotype trajectory. Furthermore, we noted that medium exhaustion led to a 30% loss of viable cells over 8 hours. Proof of concept studies also showed that FOPMKs can be cultured in scaled-down suspension systems (ambr-15 and spinner flask culture) whilst retaining CQAs. 1. Moreau, T. et al. Large-scale production of megakaryocytes from human pluripotent stem cells by chemically defined forward programming. Nat. Commun. 7, 1–15 (2016). 2. Stacey, A. J., Cheeseman, E. A., Glen, K. E., Moore, R. L. L. & Thomas, R. J. Experimentally integrated dynamic modelling for intuitive optimisation of cell-based processes and manufacture. Biochem. Eng. J. 132, 130–138 (2018)
TGF-b2 induction regulates invasiveness of theileria-transformed leukocytes and disease susceptibility
Theileria parasites invade and transform bovine leukocytes causing either East Coast fever (T. parva), or tropical theileriosis (T. annulata). Susceptible animals usually die within weeks of infection, but indigenous infected cattle show markedly reduced pathology, suggesting that host genetic factors may cause disease susceptibility. Attenuated live vaccines are widely used to control tropical theileriosis and attenuation is associated with reduced invasiveness of infected macrophages in vitro. Disease pathogenesis is therefore linked to aggressive invasiveness, rather than uncontrolled proliferation of Theileria-infected leukocytes. We show that the invasive potential of Theileria-transformed leukocytes involves TGF-b signalling. Attenuated live vaccine lines express reduced TGF-b2 and their invasiveness can be rescued with exogenous TGF-b. Importantly, infected macrophages from disease susceptible Holstein-Friesian (HF) cows express more TGF-b2 and traverse Matrigel with great efficiency compared to those from disease-resistant Sahiwal cattle. Thus, TGF-b2 levels correlate with disease susceptibility. Using fluorescence and time-lapse video microscopy we show that Theileria-infected, disease-susceptible HF macrophages exhibit increased actin dynamics in their lamellipodia and podosomal adhesion structures and develop more membrane blebs. TGF-b2-associated invasiveness in HF macrophages has a transcription-independent element that relies on cytoskeleton remodelling via activation of Rho kinase (ROCK). We propose that a TGF-b autocrine loop confers an amoeboid-like motility on Theileria-infected leukocytes, which combines with MMP-dependent motility to drive invasiveness and virulence
Carbon dynamics of the Weddell Gyre, Southern Ocean
The accumulation of carbon within the Weddell Gyre and its exchanges across the gyre boundaries are investigated with three recent full-depth oceanographic sections enclosing this climatically important region. The combination of carbonmeasurements with ocean circulation transport estimates from a box inverse analysis reveals that deepwater transports associated with Warm Deep Water (WDW) and Weddell Sea Deep Water dominate the gyre’s carbon budget, while a dual-cell vertical overturning circulation leads to both upwelling and the delivery of large quantities of carbon to the deep ocean. Historical sea surface pCO2 observations, interpolated using a neural network technique, confirm the net summertime sink of 0.044 to 0.058 ± 0.010 Pg C / yr derived from the inversion. However, a wintertime outgassing signal similar in size results in a statistically insignificant annual air-to-sea CO2 flux of 0.002± 0.007 Pg C / yr (mean 1998–2011) to 0.012 ± 0.024 Pg C/ yr (mean 2008–2010) to be diagnosed for the Weddell Gyre. A surface layer carbon balance, independently derived fromin situ biogeochemical measurements, reveals that freshwater inputs and biological drawdown decrease surface ocean inorganic carbon levels more than they are increased by WDW entrainment, resulting in an estimated annual carbon sink of 0.033 ± 0.021 Pg C / yr. Although relatively less efficient for carbon uptake than the global oceans, the summertime Weddell Gyre suppresses the winter outgassing signal, while its biological pump and deepwater formation act as key conduits for transporting natural and anthropogenic carbon to the deep ocean where they can reside for long time scales
Diffusion-weighted magnetic resonance imaging detection of basal forebrain cholinergic degeneration in a mouse model
Loss of basal forebrain cholinergic neurons is an early and key feature of Alzheimer's disease, and magnetic resonance imaging (MRI) volumetric measurement of the basal forebrain has recently gained attention as a potential diagnostic tool for this condition. The aim of this study was to determine whether loss of basal forebrain cholinergic neurons underpins changes which can be detected through diffusion MRI using diffusion tensor imaging (DTI) and probabilistic tractography in a mouse model. To cause selective basal forebrain cholinergic degeneration, the toxin saporin conjugated to a p75 neurotrophin receptor antibody (mu-p75-SAP) was used. This resulted in similar to 25% loss of the basal forebrain cholinergic neurons and significant loss of terminal cholinergic projections in the hippocampus, as determined by histology. To test whether lesion of cholinergic neurons caused basal forebrain, hippocampal, or whole brain atrophy, we performed manual segmentation analysis, which revealed no significant atrophy in lesioned animals compared to controls (Rb-IgG-SAP). However, analysis by DTI of the basal forebrain area revealed a significant increase in fractional anisotropy (FA; + 7.7%), mean diffusivity (MD; + 6.1%), axial diffusivity (AD; + 8.5%) and radial diffusivity (RD; +4.0%) in lesioned mice compared to control animals. These parameters strongly inversely correlated with the number of choline acetyl transferase-positive neurons, with FA showing the greatest association (r(2) = 0.72), followed by MD (r(2) = 0.64), AD (r(2) = 0.64) and RD (r(2) = 0.61). Moreover, probabilistic tractography analysis of the septo-hippocampal tracts originating from the basal forebrain revealed an increase in streamline MD (+5.1%) and RD (+4.3%) in lesioned mice. This study illustrates that moderate loss of basal forebrain cholinergic neurons (representing only a minor proportion of all septo-hippocampal axons) can be detected by measuring either DTI parameters of the basal forebrain nuclei or tractography parameters of the basal forebrain tracts. These findings provide increased support for using DTI and probabilistic tractography as non-invasive tools for diagnosing and/or monitoring the progression of conditions affecting the integrity of the basal forebrain cholinergic system in humans, including Alzheimer's disease. Crown Copyright (C) 2012 Published by Elsevier Inc. All rights reserved
The genetic heterogeneity and mutational burden of engineered melanomas in zebrafish models.
BACKGROUND: Melanoma is the most deadly form of skin cancer. Expression of oncogenic BRAF or NRAS, which are frequently mutated in human melanomas, promote the formation of nevi but are not sufficient for tumorigenesis. Even with germline mutated p53, these engineered melanomas present with variable onset and pathology, implicating additional somatic mutations in a multi-hit tumorigenic process. RESULTS: To decipher the genetics of these melanomas, we sequence the protein coding exons of 53 primary melanomas generated from several BRAF(V600E) or NRAS(Q61K) driven transgenic zebrafish lines. We find that engineered zebrafish melanomas show an overall low mutation burden, which has a strong, inverse association with the number of initiating germline drivers. Although tumors reveal distinct mutation spectrums, they show mostly C > T transitions without UV light exposure, and enrichment of mutations in melanogenesis, p53 and MAPK signaling. Importantly, a recurrent amplification occurring with pre-configured drivers BRAF(V600E) and p53-/- suggests a novel path of BRAF cooperativity through the protein kinase A pathway. CONCLUSION: This is the first analysis of a melanoma mutational landscape in the absence of UV light, where tumors manifest with remarkably low mutation burden and high heterogeneity. Genotype specific amplification of protein kinase A in cooperation with BRAF and p53 mutation suggests the involvement of melanogenesis in these tumors. This work is important for defining the spectrum of events in BRAF or NRAS driven melanoma in the absence of UV light, and for informed exploitation of models such as transgenic zebrafish to better understand mechanisms leading to human melanoma formation
A Guide for Social Science Journal Editors on Easing into Open Science
Journal editors have a large amount of power to advance open science in their respective fields by incentivising and mandating open policies and practices at their journals. The Data PASS Journal Editors Discussion Interface (JEDI, an online community for social science journal editors: www.dpjedi.org) has collated several resources on embedding open science in journal editing (www.dpjedi.org/resources). However, it can be overwhelming as an editor new to open science practices to know where to start. For this reason, we created a guide for journal editors on how to get started with open science. The guide outlines steps that editors can take to implement open policies and practices within their journal, and goes through the what, why, how, and worries of each policy and practice. This manuscript introduces and summarizes the guide (full guide: https://osf.io/hstcx).<br/
The immediate and long-term effects of exercise and patient education on physical, functional, and quality-of-life outcome measures after single-level lumbar microdiscectomy: a randomized controlled trial protocol
BACKGROUND: Low back pain remains a costly quality-of-life-related health problem. Microdiscectomy is often the surgical procedure of choice for a symptomatic, single-level, lumbar disc herniation in younger and middle-aged adults. The question of whether a post-microdiscectomy exercise program enhances function, quality of life, and disability status has not been systematically explored. Thus, the overall purpose of this study is to assess immediate and long-term outcomes of an exercise program, developed at University of Southern California (USC), targeting the trunk and lower extremities (USC Spine Exercise Program) for persons who have undergone a single-level microdiscectomy for the first time. METHODS/DESIGN: One hundred individuals between the ages of 18 and 60 who consent to undergo lumbar microdiscectomy will be recruited to participate in this study. Subjects will be randomly assigned to one of two groups: 1) one session of back care education, or 2) a back care education session followed by the 12-week USC Spine Exercise Program. The outcome examiners (evaluators), as well as the data managers, will be blinded to group allocation. Education will consist of a one-hour "one-on-one" session with the intervention therapist, guided by an educational booklet specifically designed for post-microdiscectomy care. This session will occur four to six weeks after surgery. The USC Spine Exercise Program consists of two parts: back extensor strength and endurance, and mat and upright therapeutic exercises. This exercise program is goal-oriented, performance-based, and periodized. It will begin two to three days after the education session, and will occur three times a week for 12 weeks. Primary outcome measures include the Oswestry Disability Questionnaire, Roland-Morris Disability Questionnaire, SF-36(® )quality of life assessment, Subjective Quality of Life Scale, 50-foot Walk, Repeated Sit-to-Stand, and a modified Sorensen test. The outcome measures in the study will be assessed before and after the 12-week post-surgical intervention program. Long-term follow up assessments will occur every six months beginning one year after surgery and ending five years after surgery. Immediate and long-term effects will be assessed using repeated measures multivariate analysis of variance (MANOVA). If significant interactions are found, one-way ANOVAs will be performed followed by post-hoc testing to determine statistically significant pairwise comparisons. DISCUSSION: We have presented the rationale and design for a randomized controlled trial evaluating the effectiveness of a treatment regimen for people who have undergone a single-level lumbar microdiscectomy
Chlamydia trachomatis infection during pregnancy associated with preterm delivery: a population-based prospective cohort study
Chlamydia trachomatis infection is the most prevalent bacterial sexually transmitted infection and may influence pregnancy outcome. This study was conducted to assess the effect of chlamydial infection during pregnancy on premature delivery and birthweight. Pregnant women attending a participating midwifery practice or antenatal clinic between February 2003 and January 2005 were eligible for the study. From 4,055 women self-administered questionnaires and urine samples, tested by PCR, were analysed for C. trachomatis infection. Pregnancy outcomes were obtained from midwives and hospital registries. Gestational ages and birthweights were analysed for 3,913 newborns. The C. trachomatis prevalence was 3.9%, but varied by age and socio-economic background. Chlamydial infection was, after adjustment for potential confounders, associated with preterm delivery before 32Â weeks (OR 4.35 [95% CI 1.3, 15.2]) and 35Â weeks gestation (OR 2.66 [95% CI 1.1, 6.5]), but not with low birthweight. Of all deliveries before 32Â weeks and 35Â weeks gestation 14.9% [95% CI 4.5, 39.5] and 7.4% [95% CI 2.5, 20.1] was attributable to C. trachomatis infection. Chlamydia trachomatis infection contributes significantly to early premature delivery and should be considered a public health problem, especially in young women and others at increased risk of C. trachomatis infection
Targeting of Natural Killer Cells by Rabbit Antithymocyte Globulin and Campath-1H: Similar Effects Independent of Specificity
T cell depleting strategies are an integral part of immunosuppressive regimens widely used in the hematological and solid organ transplant setting. Although it is known to induce lymphocytopenia, little is known about the effects of the polyclonal rabbit antithymocyte globulin (rATG) or the monoclonal anti-CD52 antibody alemtuzumab on Natural Killer (NK) cells in detail. Here, we demonstrate that induction therapy with rATG following kidney/pancreas transplantation results in a rapid depletion of NK cells. Treatment of NK cells with rATG and alemtuzumab in vitro leads to impairment of cytotoxicity and induction of apoptosis even at a 10-fold lower concentration (0.1 µg/ml) compared with T and B cells. By generating Fc-parts of rATG and alemtuzumab we illustrate that their ligation to FcγRIII (CD16) is sufficient for the significant induction of degranulation, apoptosis and inflammatory cytokine release (FasL, TNFα and IFNγ) exclusively in CD3−CD56dim NK cells whereas application of rATG and alemtuzumab F(ab) fragments abolishes these effects. These findings are of general importance as our data suggest that NK cells are also mediators of the clinically relevant cytokine release syndrome and that their targeting by therapeutic antibodies should be considered as they are functionally relevant for the effective clearance of opportunistic viral infections and anti-tumor activity posttransplantation
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