45 research outputs found
The myofibroblast matrix: implications for tissue repair and fibrosis
Myofibroblasts, and the extracellular matrix ( ECM ) in which they reside, are critical components of wound healing and fibrosis. The ECM , traditionally viewed as the structural elements within which cells reside, is actually a functional tissue whose components possess not only scaffolding characteristics, but also growth factor, mitogenic, and other bioactive properties. Although it has been suggested that tissue fibrosis simply reflects an ‘exuberant’ wound‐healing response, examination of the ECM and the roles of myofibroblasts during fibrogenesis instead suggest that the organism may be attempting to recapitulate developmental programmes designed to regenerate functional tissue. Evidence of this is provided by the temporospatial re‐emergence of embryonic ECM proteins by fibroblasts and myofibroblasts that induce cellular programmatic responses intended to produce a functional tissue. In the setting of wound healing (or physiological fibrosis), this occurs in a highly regulated and exquisitely choreographed fashion which results in cessation of haemorrhage, restoration of barrier integrity, and re‐establishment of tissue function. However, pathological tissue fibrosis, which oftentimes causes organ dysfunction and significant morbidity or mortality, likely results from dysregulation of normal wound‐healing processes or abnormalities of the process itself. This review will focus on the myofibroblast ECM and its role in both physiological and pathological fibrosis, and will discuss the potential for therapeutically targeting ECM proteins for treatment of fibrotic disorders.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94657/1/path4104.pd
Alignment of the ALICE Inner Tracking System with cosmic-ray tracks
37 pages, 15 figures, revised version, accepted by JINSTALICE (A Large Ion Collider Experiment) is the LHC (Large Hadron Collider) experiment devoted to investigating the strongly interacting matter created in nucleus-nucleus collisions at the LHC energies. The ALICE ITS, Inner Tracking System, consists of six cylindrical layers of silicon detectors with three different technologies; in the outward direction: two layers of pixel detectors, two layers each of drift, and strip detectors. The number of parameters to be determined in the spatial alignment of the 2198 sensor modules of the ITS is about 13,000. The target alignment precision is well below 10 micron in some cases (pixels). The sources of alignment information include survey measurements, and the reconstructed tracks from cosmic rays and from proton-proton collisions. The main track-based alignment method uses the Millepede global approach. An iterative local method was developed and used as well. We present the results obtained for the ITS alignment using about 10^5 charged tracks from cosmic rays that have been collected during summer 2008, with the ALICE solenoidal magnet switched off.Peer reviewe
Broadband Multi-wavelength Properties of M87 during the 2017 Event Horizon Telescope Campaign
Abstract: In 2017, the Event Horizon Telescope (EHT) Collaboration succeeded in capturing the first direct image of the center of the M87 galaxy. The asymmetric ring morphology and size are consistent with theoretical expectations for a weakly accreting supermassive black hole of mass ∼6.5 × 109 M ⊙. The EHTC also partnered with several international facilities in space and on the ground, to arrange an extensive, quasi-simultaneous multi-wavelength campaign. This Letter presents the results and analysis of this campaign, as well as the multi-wavelength data as a legacy data repository. We captured M87 in a historically low state, and the core flux dominates over HST-1 at high energies, making it possible to combine core flux constraints with the more spatially precise very long baseline interferometry data. We present the most complete simultaneous multi-wavelength spectrum of the active nucleus to date, and discuss the complexity and caveats of combining data from different spatial scales into one broadband spectrum. We apply two heuristic, isotropic leptonic single-zone models to provide insight into the basic source properties, but conclude that a structured jet is necessary to explain M87’s spectrum. We can exclude that the simultaneous γ-ray emission is produced via inverse Compton emission in the same region producing the EHT mm-band emission, and further conclude that the γ-rays can only be produced in the inner jets (inward of HST-1) if there are strongly particle-dominated regions. Direct synchrotron emission from accelerated protons and secondaries cannot yet be excluded
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A rice-derived recombinant human lactoferrin stimulates fibroblast proliferation, migration, and sustains cell survival
Human lactoferrin (hLF), a glycoprotein of the transferrin family, has recently been shown to stimulate wound repair through its antimicrobial effect and inflammation modulation. A recent study with several non-skin cell lines indicated that hLF may also have a stimulatory effect on cell proliferation. To explore the role of hLF in wound healing, we used recombinant human lactoferrin (holo-rhLF), derived from transgenic rice, to examine the effects of holo-rhLF on cell proliferation, migration, attachment, and survival in a human primary skin fibroblast culture system. This study revealed that holo-rhLF not only significantly stimulates fibroblast proliferation but also has synergistic effects with fibroblast growth factor-2 and antagonistic effects with transforming growth factor-β1 on cell proliferation. Furthermore, using a chamber migration assay, our results demonstrate that holo-rhLF promotes fibroblast migration in a dosage-dependent manner. More importantly, holo-rhLF significantly increased cell viability and protected cells from death when they were stressed by either serum depletion or 12-O-tetradecanoylphorbol-13-acetate exposure. No significant effect was observed on cell attachment. In conclusion, these findings reveal the multiple functions of holo-rhLF in human skin fibroblasts and indicate its potential application in wound therapy by enhancing cell proliferation and migration as well as protecting cells from apoptosis
Pancreatic cancer clusters and arsenic-contaminated drinking water wells in Florida
BACKGROUND: We sought to identify high-risk areas of pancreatic cancer incidence, and determine if clusters of persons diagnosed with pancreatic cancer were more likely to be located near arsenic-contaminated drinking water wells. METHODS: A total of 5,707 arsenic samples were collected from December 2000 to May 2008 by the Florida Department of Health, representing more than 5,000 individual privately owned wells. During that period, 0.010 ppm (10 ppb) or greater arsenic levels in private well water were considered as the threshold based on standard of United States Environmental Protection Agency (EPA). Spatial modeling was applied to pancreatic cancer cases diagnosed between 1998–2002 in Florida (n = 11,405). Multivariable logistic regression was used to determine if sociodemographic indicators, smoking history, and proximity to arsenic-contaminated well sites were associated with residence at the time of pancreatic cancer diagnosis occurring within versus outside a cluster. RESULTS: Spatial modeling identified 16 clusters in which 22.6% of all pancreatic cancer cases were located. Cases living within 1 mile of known arsenic-contaminated wells were significantly more likely to be diagnosed within a cluster of pancreatic cancers relative to cases living more than 3 miles from known sites (odds ratio = 2.1 [95% CI = 1.9, 2.4]). CONCLUSIONS: Exposure to arsenic-contaminated drinking water wells may be associated with an increased risk of pancreatic cancer. However, case–control studies are needed in order to confirm the findings of this ecological analysis. These cluster areas may be appropriate to evaluate pancreatic cancer risk factors, and to perform targeted screening and prevention studies
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Abstract 247: Association of Soluble RAGE Levels with Carotid Atherosclerosis: The Northern Manhattan Study (NOMAS)
Introduction
The Receptor for Advanced Glycation End-products (RAGE) is a multi-ligand receptor that propagates vascular cell dysfunction leading to proinflammatory disease states. RAGE is produced as a membrane bound and soluble isoform (soluble RAGE (sRAGE)), with the soluble isoform demonstrated to act as a RAGE decoy preventing cellular activation and atherosclerosis. Recent cohort studies have suggested that serum levels of sRAGE are associated with the risk of CVD and therefore may be a novel biomarker for cardiovascular disease states.
Hypothesis
We hypothesized that sRAGE levels are associated with subclinical atherosclerosis in an ethnically diverse population.
Methods
We included 1,102 stroke-free participants from the multi-ethnic Northern Manhattan Study (NOMAS) who underwent high-resolution carotid B-mode ultrasound to measure carotid plaque phenotypes (density, thickness, and area) and carotid intima-media thickness (IMT). Plaque density was characterized by Gray Scale Median (GSM). Serum sRAGE was measured by ELISA and log-transformed to stabilize variance. Multiple linear and logistic regressions were employed to estimate sRAGE associations with IMT and plaque measures.
Results
The mean age at time of ultrasound was 70.7±8.6yrs; 65% were Hispanic, 19% black, and 16% white. The majority of subjects had carotid plaque present (54%) with the median GSM 38(0-190). Mean plaque thickness (IQR) was 1.30(0-3.99)mm and mean area (IQR) 2.43(0-96.75)mm2. Mean IMT was 0.93±0.09mm. High sRAGE levels were associated with more echolucent plaques (OR 1.2, 95% CI 1.03-1.42), especially among Hispanics (OR 1.26, 95% CI 1.04-1.54). These relationships remained after adjusting for sociodemographic and vascular risk factors. No association was seen between sRAGE levels and carotid IMT, plaque thickness or area.
Conclusion
In the present study, higher sRAGE levels were associated with echolucent (lower density) plaque, especially among Hispanic subjects. Our data suggest sRAGE levels may be associated with atherosclerotic plaque morphology and its vulnerability, especially among minority groups. These findings further support RAGE as a novel target for anti-atherosclerosis interventions
Polygenic model of DNA repair genetic polymorphisms in human breast cancer risk
Genetic variations in DNA repair may impact repair functions, DNA damage and breast cancer risk. Using data/samples collected from the first 752 Caucasians and 141 African-Americans in an ongoing case-control study, we examined the association between breast cancer risk and 18 non-synonymous single-nucleotide polymorphisms (nsSNPs) in four DNA repair pathways-(i) base excision repair: ADPRT V762A, APE1 D148E, XRCC1 R194W/R280H/R399Q and POLD1 R119H; (ii) nucleotide excision repair: ERCC2 D312N/K751Q, ERCC4 R415Q, ERCC5 D1104H and XPC A499V/K939Q; (iii) mismatch repair: MLH1 I219V, MSH3 R940Q/T1036A and MSH6 G39E and (iv) double-strand break repair: NBS1 E185Q and XRCC3 T241M. In Caucasians, breast cancer risk was significantly associated with ADPRT 762VV [odds ratio (OR) = 1.45; 95% confidence interval (CI) = 1.03, 2.03], APE1 148DD (OR = 1.44; 95% CI = 1.03, 2.00), MLH1 219II/IV (OR = 1.87; 95% CI = 1.11, 3.16) and ERCC4 415QQ (OR = 8.64; 95% CI = 1.04, 72.02) genotypes. With a limited sample size, we did not observe any significant association in African-Americans. However, there were significant trends in breast cancer risk with increasing numbers of risk genotypes for ADPRT 762VV, APE1 148DD, ERCC4 415RQ/QQ and MLH1 219II/IV (P
trend < 0.001) in Caucasians and ADPRT 762VA, ERCC2 751KQ/QQ and NBS1 185EQ/QQ in African-Americans (P
trend = 0.006), respectively. Our results suggest that combined nsSNPs in multiple DNA repair pathways may contribute to breast cancer risk and larger studies are warranted to further evaluate polygenic models of DNA repair in breast cancer risk