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Dynamic stem cell selection safeguards the genomic integrity of the epidermis. Dev Cell 2021; 56:3309-3320.e5. [PMID: 34932948 DOI: 10.1016/j.devcel.2021.11.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 09/14/2021] [Accepted: 11/16/2021] [Indexed: 12/31/2022]
Abstract
Maintaining genomic integrity and stability is crucial for life; yet, no tissue-driven mechanism that robustly safeguards the epithelial genome has been discovered. Epidermal stem cells (EpiSCs) continuously replenish the stratified layers of keratinocytes that protect organisms against various environmental stresses. To study the dynamics of DNA-damaged cells in tissues, we devised an in vivo fate tracing system for EpiSCs with DNA double-strand breaks (DSBs) and demonstrated that those cells exit from their niches. The clearance of EpiSCs with DSBs is caused by selective differentiation and delamination through the DNA damage response (DDR)-p53-Notch/p21 axis, with the downregulation of ITGB1. Moreover, concomitant enhancement of symmetric cell divisions of surrounding stem cells indicates that the selective elimination of cells with DSBs is coupled with the augmented clonal expansion of intact stem cells. These data collectively demonstrate that tissue autonomy through the dynamic coupling of cell-autonomous and non-cell-autonomous mechanisms coordinately maintains the genomic quality of the epidermis.
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EGFR-mediated epidermal stem cell motility drives skin regeneration through COL17A1 proteolysis. J Cell Biol 2021; 220:e202012073. [PMID: 34550317 PMCID: PMC8563287 DOI: 10.1083/jcb.202012073] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 06/25/2021] [Accepted: 08/12/2021] [Indexed: 01/09/2023] Open
Abstract
Skin regenerative capacity declines with age, but the underlying mechanisms are largely unknown. Here we demonstrate a functional link between epidermal growth factor receptor (EGFR) signaling and type XVII collagen (COL17A1) proteolysis on age-associated alteration of keratinocyte stem cell dynamics in skin regeneration. Live-imaging and computer simulation experiments predicted that human keratinocyte stem cell motility is coupled with self-renewal and epidermal regeneration. Receptor tyrosine kinase array identified the age-associated decline of EGFR signaling in mouse skin wound healing. Culture experiments proved that EGFR activation drives human keratinocyte stem cell motility with increase of COL17A1 by inhibiting its proteolysis through the secretion of tissue inhibitor of metalloproteinases 1 (TIMP1). Intriguingly, COL17A1 directly regulated keratinocyte stem cell motility and collective cell migration by coordinating actin and keratin filament networks. We conclude that EGFR-COL17A1 axis-mediated keratinocyte stem cell motility drives epidermal regeneration, which provides a novel therapeutic approach for age-associated impaired skin regeneration.
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Obesity accelerates hair thinning by stem cell-centric converging mechanisms. Nature 2021; 595:266-271. [PMID: 34163066 PMCID: PMC9600322 DOI: 10.1038/s41586-021-03624-x] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Accepted: 05/07/2021] [Indexed: 02/06/2023]
Abstract
Obesity is a worldwide epidemic that predisposes individuals to many age-associated diseases, but its exact effects on organ dysfunction are largely unknown1. Hair follicles-mini-epithelial organs that grow hair-are miniaturized by ageing to cause hair loss through the depletion of hair follicle stem cells (HFSCs)2. Here we report that obesity-induced stress, such as that induced by a high-fat diet (HFD), targets HFSCs to accelerate hair thinning. Chronological gene expression analysis revealed that HFD feeding for four consecutive days in young mice directed activated HFSCs towards epidermal keratinization by generating excess reactive oxygen species, but did not reduce the pool of HFSCs. Integrative analysis using stem cell fate tracing, epigenetics and reverse genetics showed that further feeding with an HFD subsequently induced lipid droplets and NF-κB activation within HFSCs via autocrine and/or paracrine IL-1R signalling. These integrated factors converge on the marked inhibition of Sonic hedgehog (SHH) signal transduction in HFSCs, thereby further depleting lipid-laden HFSCs through their aberrant differentiation and inducing hair follicle miniaturization and eventual hair loss. Conversely, transgenic or pharmacological activation of SHH rescued HFD-induced hair loss. These data collectively demonstrate that stem cell inflammatory signals induced by obesity robustly represses organ regeneration signals to accelerate the miniaturization of mini-organs, and suggests the importance of daily prevention of organ dysfunction.
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Expansion and characterization of epithelial stem cells with potential for cyclical hair regeneration. Sci Rep 2021; 11:1173. [PMID: 33568688 PMCID: PMC7876088 DOI: 10.1038/s41598-020-80624-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 12/21/2020] [Indexed: 12/17/2022] Open
Abstract
In mammals, organ induction occurs only during embryonic development except for hair follicles (HFs). However, HF-resident epithelial stem cells (HFSCs), which are responsible for repetitive HF regeneration, are not fully characterized. Here, we establish in vitro culture systems that are capable of controlling the ability of HFSCs to regenerate HFs. Based on a method that precisely controlled the number of HFs for regeneration, functional analysis revealed that CD34/CD49f/integrin β5 (Itgβ5)-triple-positive (CD34+/CD49f+/Itgβ5+) cells have multipotency and functional significance for continual hair regeneration. In native HFs, these cells reside in the uppermost area of the bulge region, which is surrounded by tenascin in mice and humans. This study unveils the subpopulation of HFSCs responsible for long-term hair cycling of HFs regenerated from bioengineered HF germ, suggesting the presence of functional heterogeneity among bulge HFSCs and the utility of our culture system to achieve HF regenerative therapy.
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Stem cell competition orchestrates skin homeostasis and ageing. Nature 2019; 568:344-350. [PMID: 30944469 DOI: 10.1038/s41586-019-1085-7] [Citation(s) in RCA: 210] [Impact Index Per Article: 42.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 03/07/2019] [Indexed: 01/09/2023]
Abstract
Stem cells underlie tissue homeostasis, but their dynamics during ageing-and the relevance of these dynamics to organ ageing-remain unknown. Here we report that the expression of the hemidesmosome component collagen XVII (COL17A1) by epidermal stem cells fluctuates physiologically through genomic/oxidative stress-induced proteolysis, and that the resulting differential expression of COL17A1 in individual stem cells generates a driving force for cell competition. In vivo clonal analysis in mice and in vitro 3D modelling show that clones that express high levels of COL17A1, which divide symmetrically, outcompete and eliminate adjacent stressed clones that express low levels of COL17A1, which divide asymmetrically. Stem cells with higher potential or quality are thus selected for homeostasis, but their eventual loss of COL17A1 limits their competition, thereby causing ageing. The resultant hemidesmosome fragility and stem cell delamination deplete adjacent melanocytes and fibroblasts to promote skin ageing. Conversely, the forced maintenance of COL17A1 rescues skin organ ageing, thereby indicating potential angles for anti-ageing therapeutic intervention.
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Evaluating Clinical and Cost Impacts of Achieving 90% HPV Vaccination Rate Against Cervical Cancer in Canada Using the OncoSim Cancer Simulation Model. J Glob Oncol 2018. [DOI: 10.1200/jgo.18.27600] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background: Cervical cancer can be largely prevented through vaccination against the human papillomavirus (HPV). In Canada, HPV vaccination of school-aged girls started in 2008 and has reached an average rate of 67% across the country. However, this rate is below a current national target of 90%. Aim: We project the difference in lifetime clinical outcomes and health system costs of achieving a 90% HPV vaccination rate versus a 67% rate for girls vaccinated in 2015 using the OncoSim-Cervical model. Methods: The OncoSim-Cervical model (version 2.5) is a microsimulation model led by the Canadian Partnership Against Cancer, with model development by Statistics Canada, to evaluate the impacts of cervical cancer interventions in Canada. It has two parts, the first, the HPV Microsimulation Model, simulates the transmission of HPV between males and females including possible modulation by vaccination and herd immunity, and provides projections of HPV infection and prevalence for input to the cervical cancer natural history component in the second part. We simulated two cohorts of 5-10 year old girls in 2015; one receiving HPV vaccination at the rate of 67% and another at 90%. Their relative lifetime cervical cancer outcomes and costs were compared. Assumptions included: 100% efficacy of the HPV vaccine; triennial cytology screening between ages 21 and 65; 90% screening recruitment of age-eligible women with 80% rescreening; and a $500 cost for a 3-dose quadrivalent HPV vaccine regimen. Projected costs were undiscounted and are in 2016 CAD. Results: Compared with the 67%-vaccinated cohort, in the 90%-vaccinated cohort there was a lifetime reduction of 23% in cervical cancer incident cases and 21% in cervical cancer deaths. Lifetime cancer treatment costs decreased by $26 million (23%), and wart treatment costs and precervical cancer costs decreased by $3.2 million (15%) and $45 million (16%) respectively. Lifetime screening costs decreased by $47 million (2%). Conclusion: Achieving a nationally-set target of 90% HPV vaccination in Canadian girls would not only save more lives but would free up funds that could be redirected to other health system needs. Planners could aim for relatively high nation-wide rates of HPV vaccination coverage to enhance their cervical cancer control strategy.
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The OncoSim Cancer Simulation Platform: A Tool to Project the Population Effects of Cancer Control Interventions in Canada. J Glob Oncol 2018. [DOI: 10.1200/jgo.18.20300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Background: Cancer control interventions exert their effects over multiple decades. To evaluate diverse and competing opportunities to reduce future cancer burden it is desirable to understand long-term effects prior to any new program implementation or significant change. Internationally, modeling is becoming an accepted source of planning information for decision-makers. Aim: We will describe the construction and use of the OncoSim microsimulation model, which was developed to evaluate cancer control strategies in Canada. Methods: OncoSim is a suite of models (cancers of the lung, colorectum, cervix and breast, plus a composite 32-cancer model) used to address key policy questions and support decision-making. It is led by the Canadian Partnership Against Cancer with model development by Statistics Canada. OncoSim incorporates risk factors, cancer natural history, screening, treatment, survival and end-of-life care. Wherever possible it is informed by Canadian data sources. Models are calibrated to reproduce a range of cancer-specific statistics, e.g., current and historical Canadian cancer-specific incidence and mortality, smoking patterns, and results of screening. The site-specific models have undergone further validation by replicating reported short-term effects of cancer prevention and screening interventions. Users may customize interventions through modifying input parameters. Outputs include incidence, mortality, costs, cost-effectiveness, and resource utilization. Users from the public sector have access at no cost to OncoSim and receive extensive support from a multidisciplinary technical team. The model is continually updated to incorporate emerging knowledge. Results: OncoSim has been used to support cancer control decision-making at the national and provincial/territorial levels. Applications include: national guidelines recommendations for colorectal and lung cancer screening; comparison of cytology vs. HPV based cervical cancer screening; and integration of smoking cessation into low-dose CT lung cancer screening. Conclusion: Validated simulation models such as OncoSim can be a versatile and efficient tool for cancer control planners to evaluate and prioritize cancer control strategies.
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Abstract
Hair follicles develop from the ectoderm in embryos and cyclically regenerate using proper spatiotemporal signaling molecules, which are conserved in organogenesis during adulthood. Previously, we demonstrated that bioengineered hair follicle germs could regenerate functional hair follicles via a three-dimensional cell manipulation technique, which we named the "organ germ method ." We could also regulate the type of hair follicle and pigmentation with correct structures by rearranging the source of the cells. In this article, we describe a detailed protocol for the regeneration of functional hair follicles and their stem cell niches by the rearrangement of embryonic or adult hair follicle-derived epithelial and mesenchymal cells.
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The OncoSim model: development and use for better decision-making in Canadian cancer control. ACTA ACUST UNITED AC 2017; 24:401-406. [PMID: 29270052 DOI: 10.3747/co.24.3850] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The Canadian Partnership Against Cancer was created in 2007 by the federal government to accelerate cancer control across Canada. Its OncoSim microsimulation model platform, which consists of a suite of specific cancer models, was conceived as a tool to augment conventional resources for population-level policy- and decision-making. The Canadian Partnership Against Cancer manages the OncoSim program, with funding from Health Canada and model development by Statistics Canada. Microsimulation modelling allows for the detailed capture of population heterogeneity and health and demographic history over time. Extensive data from multiple Canadian sources were used as inputs or to validate the model. OncoSim has been validated through expert consultation; assessments of face validity, internal validity, and external validity; and model fit against observed data. The platform comprises three in-depth cancer models (lung, colorectal, cervical), with another in-depth model (breast) and a generalized model (25 cancers) being in development. Unique among models of its class, OncoSim is available online for public sector use free of charge. Users can customize input values and output display, and extensive user support is provided. OncoSim has been used to support decision-making at the national and jurisdictional levels. Although simulation studies are generally not included in hierarchies of evidence, they are integral to informing cancer control policy when clinical studies are not feasible. OncoSim can evaluate complex intervention scenarios for multiple cancers. Canadian decision-makers thus have a powerful tool to assess the costs, benefits, cost-effectiveness, and budgetary effects of cancer control interventions when faced with difficult choices for improvements in population health and resource allocation.
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Bioengineering a 3D integumentary organ system from iPS cells using an in vivo transplantation model. SCIENCE ADVANCES 2016; 2:e1500887. [PMID: 27051874 PMCID: PMC4820374 DOI: 10.1126/sciadv.1500887] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 02/29/2016] [Indexed: 05/05/2023]
Abstract
The integumentary organ system is a complex system that plays important roles in waterproofing, cushioning, protecting deeper tissues, excreting waste, and thermoregulation. We developed a novel in vivo transplantation model designated as a clustering-dependent embryoid body transplantation method and generated a bioengineered three-dimensional (3D) integumentary organ system, including appendage organs such as hair follicles and sebaceous glands, from induced pluripotent stem cells. This bioengineered 3D integumentary organ system was fully functional following transplantation into nude mice and could be properly connected to surrounding host tissues, such as the epidermis, arrector pili muscles, and nerve fibers, without tumorigenesis. The bioengineered hair follicles in the 3D integumentary organ system also showed proper hair eruption and hair cycles, including the rearrangement of follicular stem cells and their niches. Potential applications of the 3D integumentary organ system include an in vitro assay system, an animal model alternative, and a bioengineered organ replacement therapy.
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Using the Cancer Risk Management Model to evaluate the health and economic impacts of cytology compared with human papillomavirus DNA testing for primary cervical cancer screening in Canada. ACTA ACUST UNITED AC 2016; 23:S56-63. [PMID: 26985148 DOI: 10.3747/co.23.2991] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND In Canada, discussion about changing from cytology to human papillomavirus (hpv) dna testing for primary screening in cervical cancer is ongoing. However, the Canadian Task Force on Preventive Health Care has not yet made a recommendation, concluding that the evidence is insufficient. METHODS We used the cervical cancer and hpv transmission models of the Cancer Risk Management Model to study the health and economic outcomes of primary cytology compared with hpv dna testing in 14 screening scenarios with varying screening modalities and intervals. Projected cervical cancer cases, deaths, colposcopies, screens, costs, and incremental cost-effectiveness were evaluated. We performed sensitivity analyses for hpv dna test costs. RESULTS Compared with triennial cytology from age 25, 5-yearly hpv dna screening alone from age 30 resulted in equivalent incident cases and deaths, but 55% (82,000) fewer colposcopies and 43% (1,195,000) fewer screens. At hpv dna screening intervals of 3 years, whether alone or in an age-based sequence with cytology, screening costs are greater, but at intervals of more than 5 years, they are lower. Scenarios on the cost-effectiveness frontier were hpv dna testing alone every 10, 7.5, 5, or 3 years, and triennial cytology starting at age 21 or 25 when combined with hpv dna testing every 3 years. CONCLUSIONS Changing from cytology to hpv dna testing as the primary screening test for cervical cancer would be an acceptable strategy in Canada with respect to incidence, mortality, screening and diagnostic test volumes.
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Micron scale directional coupler as a transducer for biochemical sensing. OPTICS EXPRESS 2015; 23:17156-17168. [PMID: 26191724 DOI: 10.1364/oe.23.017156] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A microfabricated directional coupler (DC) was used for the detection of DNA conjugated with quantum dots. Output optical signals from DCs of a wide range of device lengths correspond well to theoretical and simulation results. Even 20 µm-long DC devices could detect changes in the output optical intensity by monitoring the near-field pattern using a CCD camera. The signal was enhanced 60 × using a 1500 µm-long DC device. For large cladding refractive-index changes between air and water, the normalized signal changed cyclically several times between 0 and 1. The results suggest that the DC can be the basis for miniaturized two-dimensionally integrated biochemical sensors.
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Pharmacologic-based strategies for smoking cessation: clinical and cost-effectiveness analyses. CADTH TECHNOLOGY OVERVIEWS 2012; 2:e2303. [PMID: 23002381 PMCID: PMC3442619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
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Fully functional hair follicle regeneration through the rearrangement of stem cells and their niches. Nat Commun 2012; 3:784. [PMID: 22510689 PMCID: PMC3337983 DOI: 10.1038/ncomms1784] [Citation(s) in RCA: 153] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2011] [Accepted: 03/12/2012] [Indexed: 12/16/2022] Open
Abstract
Organ replacement regenerative therapy is purported to enable the replacement of organs damaged by disease, injury or aging in the foreseeable future. Here we demonstrate fully functional hair organ regeneration via the intracutaneous transplantation of a bioengineered pelage and vibrissa follicle germ. The pelage and vibrissae are reconstituted with embryonic skin-derived cells and adult vibrissa stem cell region-derived cells, respectively. The bioengineered hair follicle develops the correct structures and forms proper connections with surrounding host tissues such as the epidermis, arrector pili muscle and nerve fibres. The bioengineered follicles also show restored hair cycles and piloerection through the rearrangement of follicular stem cells and their niches. This study thus reveals the potential applications of adult tissue-derived follicular stem cells as a bioengineered organ replacement therapy. Bioengineered hair follicles can be produced from embryonic follicle germ cells, but whether these follicles can interact with the surrounding tissue and function normally is unknown. Here, bioengineered hair follicles transplanted into mouse dermis make connections with the surrounding tissue and show normal hair cycles.
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Single follicular unit transplantation reconstructs arrector pili muscle and nerve connections and restores functional hair follicle piloerection. J Dermatol 2012; 39:682-7. [PMID: 22380609 DOI: 10.1111/j.1346-8138.2012.01505.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The autologous transplantation of hair follicles that have been separated into single follicular units is an accepted treatment for androgenetic alopecia. Recent studies demonstrate that the multiple stem cell populations and surrounding cutaneous tissues coordinately regulate the hair follicle functions and skin homeostasis. Therefore, the critical issues for consideration regarding functional hair restoration therapy are reproduction the correct connectivity and cooperation with host cutaneous tissues, including the arrector pili muscle (APM) and nerve system. We report successful establishment of mouse single follicular transplantation model and autonomous restoration of transplanted hair follicle piloerection in mouse skin. Transplanted hair follicles were responsive to the neurotransmitter acetylcholine and formed proper connections with surrounding host tissues such as APM and nerve fibers, which in turn connect with not only the hair follicle bulge region but also the APM. These results demonstrate that the piloerection ability of transplanted hair follicles can be estimated quantitatively. This study makes a substantial contribution towards the development of transplantation therapy that will facilitate future functional regeneration therapy for skin and skin appendages.
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Clopidogrel versus Other Antiplatelet Agents for Secondary Prevention of Vascular Events in Adults with Acute Coronary Syndrome or Peripheral Vascular Disease: Clinical and Cost-Effectiveness Analyses. CADTH TECHNOLOGY OVERVIEWS 2012; 2:e2102. [PMID: 23002374 PMCID: PMC3442610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
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Clopidogrel compared with other antiplatelet agents for secondary prevention of vascular events in adults undergoing percutaneous coronary intervention: clinical and cost-effectiveness analyses. CADTH TECHNOLOGY OVERVIEWS 2012; 2:e2103. [PMID: 23002375 PMCID: PMC3442611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
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Impact of increased use of adjuvant chemotherapy in non-small cell lung cancer: A population and economic assessment. J Clin Oncol 2011. [DOI: 10.1200/jco.2011.29.15_suppl.e16630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Chemically-Enhanced GaAs Maskless Etching Using a Novel Focused Ion Beam Etching System with a Chlorine Molecular and Radical Beam. ACTA ACUST UNITED AC 2011. [DOI: 10.1557/proc-75-107] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
AbstractChlorine-enhanced GaAs maskless etching using a novel focused-ion-beametching (FIBE) system has been examined for establishing high-rate and smooth FIBE. The system is composed of an air-locked ultrahigh-vacuum chamber, a 30 KeV Ga+ FIB column and two kinds of chlorine-irradiation nozzles. A fine nozzle enabled us to irradiate a high-density Cl2 flux on a desired, small area of the sample while retaining a sufficiently low surrounding-gas pressure for stable Ga+ FIB emission. Highly chemically-enhanced sputtering yields (up to 50 GaAs molecules per incident ion) were obtained. At the maximum yield, line-scanned deep-groove (6.5 um) etching with a smooth surface, capable of fabricating a laser-cavity optical mirror, was demonstrated. The chemical-enhancement effect showed high FIB-scanning-time dependence. This effect was also observed by irradiating with a plasma-dissociated Cl radicals using a novel radical beam gun. An analytical model, based on the Ga+-ion bombardment on the chlorine-adsorbed substrate surface, suggested that the maximum chemical enhancement is obtained when the Ga+-FIB scanning time is adjusted to the chlorine-coverage time, given by the Cl2-molecule or Cl-radical flux density.
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The balance between transient and sustained temporal response varies across the V1 visual field map. J Vis 2010. [DOI: 10.1167/8.6.294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Correlation of fMRI responses to absolute luminance changes in visual cortex. J Vis 2010. [DOI: 10.1167/7.9.241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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The effect of higher-order dispersion on slow light propagation in photonic crystal waveguides. OPTICS EXPRESS 2006; 14:1658-1672. [PMID: 19503493 DOI: 10.1364/oe.14.001658] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We have studied the dispersion of ultrafast pulses in a photonic crystal waveguide as a function of optical frequency, in both experiment and theory. With phase-sensitive and time-resolved near-field microscopy, the light was probed inside the waveguide in a non-invasive manner. The effect of dispersion on the shape of the pulses was determined. As the optical frequency decreased, the group velocity decreased. Simultaneously, the measured pulses were broadened during propagation, due to an increase in group velocity dispersion. On top of that, the pulses exhibited a strong asymmetric distortion as the propagation distance increased. The asymmetry increased as the group velocity decreased. The asymmetry of the pulses is caused by a strong increase of higher order dispersion. As the group velocity was reduced to 0.116(9) .c, we found group velocity dispersion of -1.1(3) .10(6) ps(2)/km and third order dispersion of up to 1.1(4) .10(5) ps(3)/km. We have modelled our interferometric measurements and included the full dispersion of the photonic crystal waveguide. Our mathematical model and the experimental findings showed a good correspondence. Our findings show that if the most commonly used slow light regime in photonic crystals is to be exploited, great care has to be taken about higher-order dispersion.
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Light-propagation characteristics of Y-branch defect waveguides in AlGaAs-based air-bridge-type two-dimensional photonic crystal slabs. OPTICS LETTERS 2002; 27:388-390. [PMID: 18007810 DOI: 10.1364/ol.27.000388] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Y-branch defect waveguides (DWGs) in an AlGaAs-based air-bridge-type two-dimensional (2D) photonic crystal (PC) slab were fabricated, and the resulting optical transmission spectra were measured. Optical beam propagation along the waveguide was successfully observed in vidicon IR images. The measured transmission spectra at the two output ports in the Y-branch DWG were remarkably similar in shape and magnitude. From comparison between the measured and calculated transmission spectra, the observed optical beam was identified as the guided mode based on the Y-branch DWG in the 2D PC slab. The results suggest that the Y-branch DWG used in the experiment has the potential to function as an ultrasmall 3-dB beam splitter with good performance.
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Complete nucleotide sequence of a Staphylococcus aureus exfoliative toxin B plasmid and identification of a novel ADP-ribosyltransferase, EDIN-C. Infect Immun 2001; 69:7760-71. [PMID: 11705958 PMCID: PMC98872 DOI: 10.1128/iai.69.12.7760-7771.2001] [Citation(s) in RCA: 109] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The complete nucleotide sequence of pETB, a 38.2-kb Staphylococcus aureus plasmid encoding the exfoliative toxin B (ETB), was determined. A total of 50 open reading frames were identified on the plasmid genome and, among these, 32 showed sequence similarity to known proteins. pETB contains three copies of IS257, which divide the pETB genome into three regions: (i) a cadmium resistance operon-containing region, (ii) a lantibiotic production gene-containing region, and (iii) the remaining part where genes for plasmid replication and/or maintenance are dispersed. In the third region, genes of various kinds of functions are present among the replication- and maintenance-related genes. They include two virulence-related genes, the etb gene and a gene encoding a novel ADP-ribosyltransferase closely related to EDIN, which belongs to the C3 family of ADP-ribosyltransferases modifying Rho GTPases. They also include genes for a cell wall-anchoring surface protein and a phage resistance protein. Based on the determined sequence of pETB, the genome structures of etb-bearing plasmids (ETB plasmids) from various clinical isolates were analyzed by the PCR scanning method. The data indicate that, although the ETB plasmids are highly heterogeneous in genome size, the fundamental genome organization is well conserved. The size variation of the plasmid is mainly attributed to defined regions which may be hot spots for gene shuffling.
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Abstract
The results of biomechanical testing of the WorldSID prototype dummy are presented in this paper. The WorldSID dummy is a new, advanced Worldwide Side Impact Dummy that has the anthropometry of a mid-sized adult male. The first prototype of this dummy has been evaluated by the WorldSID Task Group against previously established corridors for its critical body regions. The response corridors are defined in the International Organization of Standardization (ISO) Technical Report 9790. The prototype is the first version of the WorldSID dummy to be built and tested. This dummy has been subjected to a rigorous program of testing to evaluate, first and foremost its biofidelity, but also its repeatability. Following this initial evaluation, any required modifications will be incorporated into a pre-production version of the WorldSID dummy so that it rates "good" to "excellent" on the ISO dummy biofidelity scale - a rating exceeding that of all current side impact dummies. Also, the overall WorldSID repeatability must not exceed a coefficient of variation of 7% at injury assessment level and this has to be verified for the different body regions. The dummy's head, neck, thorax, abdomen and pelvis were evaluated against the ISO technical report requirements. Testing included drop tests, pendulum impacts, and sled tests. The biofidelity rating of the WorldSID prototype was calculated using the weighted biomechanical test response procedure developed by ISO. The paper presents the results of the testing, which give a very positive indication of the dummy's potential. Based on this evaluation of the dummy biofidelity, the WorldSID prototype dummy exhibits a biofidelity rating of 6.15 that corresponds to an ISO biofidelity classification of "fair". In addition, the dummy shows good repeatability with a global coefficient of variation of 3.30% for the pendulum and rigid sled tests.
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Cultural variations in optimistic and pessimistic bias: do Easterners really expect the worst and Westerners really expect the best when predicting future life events? J Pers Soc Psychol 2001; 81:476-91. [PMID: 11554648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
The authors compared levels of optimistic and pessimistic bias in the prediction of positive and negative life events between European Americans and Japanese. Study 1 showed that European Americans compared with Japanese were more likely to predict positive events to occur to self than to others. The opposite pattern emerged in the prediction of negative events. Study 2 replicated these cultural differences. Furthermore, positive associations emerged between predictions and occurrence of life events 2 months later for both European Americans and Japanese. Across both studies, results of within-groups analyses indicated that both groups expected negative events to be more likely to occur to others than to self (optimistic bias). In addition, Japanese expected positive events to be more likely to occur to others than to self (pessimistic bias). However, European Americans failed to show the expected optimistic bias for positive events.
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[Effects of cernitin pollen-extract (Cernilton) on inflammatory cytokines in sex-hormone-induced nonbacterial prostatitis rats]. HINYOKIKA KIYO. ACTA UROLOGICA JAPONICA 2001; 47:459-65. [PMID: 11523128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Cernitin pollen-extract (Cernilton, CN) is a preparation made from eight kinds of pollen and has been used for various prostatic diseases in Japan and Europe. We reported previously that CN possessed a recovery action on the sex-hormone-induced nonbacterial prostatitis in rats. To clarify the possible mechanism of action of CN, we investigated the effects of CN on inflammatory cytokines (IL-1 beta, IL-6 and TNF-alpha) in the same model. Aged Wistar rats were castrated and injected 17 beta-estradiol (0.25 mg/kg/day, s.c.) for 30 days. CN (630 and 1,260 mg/kg, p.o.) or testosterone (2.5 mg/kg, s.c.) was administered for the last 14 days of the treatment of 17 beta-estradiol. In control rats, prostatic IL-6 and TNF-alpha contents were increased approximately 2-3 fold, and acinar glandular inflammation and stromal proliferation were found histopathologically, as compared with those of intact rats. On the other hand, CN decreased the increased contents of cytokines in a dose-dependent manner. The histopathological changes mentioned above were restored in rats treated with 1,260 mg/kg. Testosterone also ameliorated them significantly. These results indicate that CN has an anti-inflammatory action, and that the inhibitory effect of CN on the prostatic inflammatory cytokine is an important factor in its action.
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Effects of insulin-like growth factor-1 on Short bowel syndrome without ileocecal valve in rats. Eur Surg Res 2001; 33:291-6. [PMID: 11684836 DOI: 10.1159/000049720] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Insulin-like growth factor-1 (IGF-1) can promote enterocyte proliferation which may be beneficial to postoperative conditions after massive small bowel resection (SBR) including the ileocecal valve (ICV). Wistar rats were subjected to SBR including or preserving ICV and continuously received IGF-1 or saline alone. Nutritional status, enterocyte proliferation, liver damage and hepatic IGF-1 mRNA levels were analyzed. Body weights, serum levels of total protein and transferrin, and enterocyte proliferation were significantly lower after SBR including ICV than preserving it. IGF-1 mRNA levels in the liver were decreased after SBR, especially after SBR including ICV. However, IGF-1 therapy significantly attenuated those decreased levels after SBR including ICV. Furthermore, IGF-1 significantly decreased serum liver transaminase levels which were increased after SBR including ICV. Continuous administration of IGF-1 may be available as a supplemented therapy for short bowel syndrome without ICV.
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Confined band gap in an air-bridge type of two-dimensional AlGaAs photonic crystal. PHYSICAL REVIEW LETTERS 2001; 86:2289-2292. [PMID: 11289911 DOI: 10.1103/physrevlett.86.2289] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/15/2000] [Indexed: 05/23/2023]
Abstract
The transmittance spectrum for an air-bridge type of AlGaAs photonic crystal (PC) slabs successfully fabricated was measured. It is found that the observed spectrum is consistent with both the theoretical band structure and the calculated one. Moreover, the transmittance due to the modes below the light line is found to be almost 100%, indicating that the guided modes should exist. The respective stop bands are observed in the gamma-M direction for TM-like and TE-like modes, implying that a photonic band gap should exist for the TE-like guided modes. The present PC is very suited for controlling the radiation field.
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Investigation of the release behavior of diethylhexyl phthalate from the polyvinyl-chloride tubing for intravenous administration. Int J Pharm 2000; 210:109-15. [PMID: 11163992 DOI: 10.1016/s0378-5173(00)00578-0] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The release behavior of diethylhexyl phthalate (DEHP) from a polyvinyl-chloride (PVC) tube, which is part of an intravenous administration set, was investigated with the coexistence of polysorbate 80 (Tween 80) in various solutions such as physiological saline (PS), distilled water for injection (DWI) and glucose solution (TZ). The cumulative amount of DEHP released after 5 h was in the following order; PS, DWI > 50% TZ. From a comparison of the amount of released DEHP and the critical micelle concentration (CMC) of various solutions, the lower the CMC of the solution, the higher the amount of DEHP released from the PVC tubing. When the concentration of Tween 80 was kept constant at 1 mg/ml, the cumulative amount of DEHP released with a flow rate 90 ml/h was higher than that at 60 ml/h. These results suggest that the release of DEHP from the PVC tubing is closely correlated with the interaction of Tween 80 and DEHP such as the formation of micelles, the collision of micelles against the surface of the PVC tubing and the diffusion properties of DEHP and or Tween 80 in the liquid medium.
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Effects of insulin-like growth factor-1 on massive resection of small intestine with or without ileocecal resection in rats. Transplant Proc 2000; 32:2486-7. [PMID: 11120259 DOI: 10.1016/s0041-1345(00)01758-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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[The mental health of school children after the Great Hanshin-Awaji Earthquake: II. Longitudinal analysis]. SEISHIN SHINKEIGAKU ZASSHI = PSYCHIATRIA ET NEUROLOGIA JAPONICA 2000; 102:481-97. [PMID: 10897679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
UNLABELLED We conducted surveys to investigate the nature of the recovery processes and psychological reactions of children and adolescents affected by the Great Hanshin Awaji Earthquake. The investigations were carried out 4 times at 4 months, 6 months, one year and two years after the disaster. SUBJECTS About 9000 school children in the 3rd grade, the 5th grade, the 8th grade living in the disaster area. METHOD The questionnaire consisted of 9-12 items regarding situation and behavior when the earthquake occurred, and 22 items regarding mental health condition, and was filled out in the classroom under supervision by the teacher in charge. The responses were rated from 1 to 4 depending on the frequency of the symptoms, and statistically analyzed. RESULTS By factor analysis, three factors were elicited. Factor 1 was interpreted as being related to fear and anxiety, factor 2 as related to depression and physical symptoms, and factor 3 as related to pro-social tendencies. These 3 factors were distinct and stable throughout all 4 surveys and each of them showed unique recovery processes. The mean score of factor 1 was highest at 4 months after the earthquake, and decreased as time passed. This factor shows that fear and anxiety seem to be directly related to the experience of the earthquake. According to the severity of the disaster, more severe damage brought about a higher mean score of factor 1. Furthermore, younger children and girls were more strongly affected. Each of the differences in the severity of disaster, in age, and in gender decreased as time passed. The mean score of factor 2 peaked at 6 months, and it slightly recovered after one year. However, the score at the 1st year was still higher than that of the 4th month. At two years the score returned to almost the same level as that of the 4th month. We think that factor 2, involving depressive mood and psychophysical symptoms, may be a secondary phenomenon to fear and anxiety. Other possibilities are that they may be caused by environmental changes after the disaster, inconveniences of daily life, loss of jobs of parents, or masked by hypomanic mood which covered over the disaster area soon after the earthquake (so-called heroic phase). Older children have a greater tolerance for depressive mood and psychophysical symptoms, but those symptoms occurring in older children have a tendency to continue for a longer time. Girls are more heavily affected and need more time to recover from trauma than boys. The mean score of factor 3 showed a gradual decrease as time passed. There was no difference in the way of decrease according to the severity of disaster, age and gender. It may be natural that, since the interest in the earthquake decreased as time passed, consideration for the victims decreased. CONCLUSIONS The problems of mental health of children and adolescents after the disaster may consist of at least 2 different components; "fear and anxiety," which appeared just after the disaster and decreased earlier; "depressive and psychophysical symptoms" appeared later and stayed longer.
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Abstract
OBJECTIVE To compare the cytomorphologic features of urine obtained from two different kinds of urinary diversions constructed after total bladder resection. STUDY DESIGN The smears of urine from 11 ileal conduits and 6 Indiana pouches were evaluated. All patients underwent total bladder resection due to transitional cell carcinoma (TCC) or other kinds of cancer before urine diversion. RESULTS The cytologic features of Indiana pouch urine include degenerated, small, round cells without columnar cells derived from intestinal epithelium. In ileal conduit urine, well-preserved columnar cells and degenerated, small, round cells were frequently observed. The columnar cells in ileal conduit urine exhibited cytologic features that should be distinguished from TCC cells. CONCLUSION The method of reconstructing the urinary tract is important in urine cytology from urine diversions because the cytomorphologic features of urine are different between the two kinds of urinary diversions. Since columnar cells in ileal conduit urine might lead to misdiagnosis as TCC, special consideration is required to examine ileal conduit urine.
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Abstract
(S,S)-Ethylenebis(tetrahydroindenyl)titanium chloride methoxide, (S, S)-(EBTHI)TiCl(OMe) (3) was synthesized from the corresponding titanium dichloride. The asymmetric aldol reaction of enol trichloroacetate of cyclohexanone 1 with aromatic aldehydes was studied in the presence of a catalytic amount of the chiral titanium complex 3, with the result that the optically active syn aldol adduct 2 was preferentially obtained with up to 91% ee.
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Abstract
Catalytic asymmetric allylation of aldehydes with allylic trimethoxysilanes was achieved with the p-Tol-BINAP small middle dotAgF complex as catalyst [Eq. (a); p-Tol-BINAP=2,2'-bis(di-p-tolylphosphanyl)-1,1'-binaphthyl)]. High anti and enantioselectivities were obtained in the reaction with crotyltrimethoxysilane, irrespective of the configuration at the double bond.
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Effect of distal stenosis of internal thoracic artery bypass grafts on longitudinal phasic blood flow velocity characteristics. Am Heart J 1999; 138:468-76. [PMID: 10467197 DOI: 10.1016/s0002-8703(99)70149-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Left internal thoracic artery (LITA) bypass conduits show gradual longitudinal transition in their phasic flow velocity patterns from the proximal to distal segments, but little is known about the influence of distal stenosis, particularly early after surgery, on that characteristic. The purpose of this study was to evaluate the influence of distal stenosis on these flow velocity patterns. METHODS We examined 24 LITAs within 1 month (7 to 30 days) after surgery with a Doppler-tipped guide wire at the proximal, mid, and distal segments. Maximum peak velocities (MPV), time averaged peak velocities (APV), and velocity-time integrals (VTI) were measured. RESULTS In LITAs without stenosis (n = 14, group A), the APV, MPV, and VTI values at the diastole were significantly greater than those for distal stenosis (minimal lumen diameter >75%, n = 10, group B). The values of the 3 indexes at the systole in each segment did not differ significantly between the 2 groups. Both groups showed gradual increases in the diastolic/systolic ratios of the 3 indexes from the proximal to distal portions, the ratios in group A being significantly larger than that in group B (APV, P <. 001; MPV, P <.01; TVI, P <.01, respectively). For these indexes, sensitivity and specificity for predicting stenosis of LITA was higher in the proximal and mid portion than in the distal. CONCLUSIONS Anastomotic stenosis decreases the diastolic flow component but not the systolic one. By using diastolic/systolic ratios of the 3 indexes, it is possible to predict distal stenosis of LITA from the resting phasic flow velocity pattern.
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[Analysis of ovarian tumors treated at Nippon Medical School Hospital in a 5-year period. Problems in a frozen section diagnosis]. NIHON IKA DAIGAKU ZASSHI 1999; 66:134-8. [PMID: 10339992 DOI: 10.1272/jnms.66.134] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Heme oxygenase-1 gene expression by a glutathione depletor, phorone, mediated through AP-1 activation in rats. Biochem Biophys Res Commun 1996; 221:259-65. [PMID: 8619843 DOI: 10.1006/bbrc.1996.0583] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
This study shows that induction of heme oxygenase-1 (HO-1) gene expression by a glutathione (GSH) depletor, phorone, is inhibited by cycloheximide pretreatment and involves changes in c-jun, not c-fos, mRNA. Buthionine sulfoximine (BSO) enhanced markedly both c-jun and HO-1 gene expression evoked by phorone. Phorone dramatically increased AP-1 binding activity, which was blocked by unlabeled AP-1 oligonucleotide and abolished by anit-Jun antibodies, but not anti-Fos antibodies. In addition, pretreatment with dexamethasone, an inhibitor of AP-1 DNA binding, inhibited phorone-mediated HO-1 mRNA induction. These findings suggest that HO-1 induction by phorone is likely to involve in the activation of AP-1 (Jun/Jun) binding, which could be associating with GSH depletion.
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[Efficacy of simultaneous function and perfusion imaging on 99mTc-tetrofosmin myocardial scintigraphy]. KAKU IGAKU. THE JAPANESE JOURNAL OF NUCLEAR MEDICINE 1995; 32:997-1005. [PMID: 8523848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The aim of this study was to determine whether the diagnosis for coronary artery disease (CAD) with 99mTc-tetrofosmin (Tf) myocardial scintigraphy was improved by the combination of function image and perfusion image as compared with perfusion alone. Tf myocardial scintigraphy was performed with one-day protocol (stress/rest) in 51 patients (CAD: 32, Non-CAD: 19) without previous myocardial infarction. Function image was obtained by first pass method, and perfusion image by SPECT. Number of diseased vessels was 14 in right coronary artery (RCA), 18 in left anterior descending (LAD), and 12 in left circumflex (LCX). Ischemia was diagnosed by 2 different parameters 1) perfusion image alone, 2) combination of perfusion image and regional ejection fraction (rEF). On perfusion image, accuracy was 53%, 94% and 86% in RCA, LAD, and LCX respectively. On perfusion + rEF, accuracy was 76%, 90% and 84% in RCA, LAD, and LCX respectively. Specificity in RCA was 45% on perfusion, 84% on perfusion + rEF. Sensitivity in RCA was 77% on perfusion, 54% on perfusion + rEF. LAD and LCX did not change by the addition of function image. By addition of function image, accuracy and specificity of diagnosis in area of RCA improved significantly (p < 0.01). Thus the addition of function image in Tf myocardial scintigraphy would be useful to improve the diagnosis, especially in region of RCA.
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[Artificial defect on myocardial SPECT image due to extra-cardiac MIBI accumulation]. KAKU IGAKU. THE JAPANESE JOURNAL OF NUCLEAR MEDICINE 1995; 32:307-10. [PMID: 7739161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
If 99mTc-methoxy isobutylisonitrile (MIBI) myocardial scintigraphy was performed on the rest-stress protocol, MIBI accumulated in extra-cardiac area, gallbladder or liver, on rest image significantly. The purpose of this study was to evaluate whether extra-cardiac MIBI accumulation influences the quality of myocardial images. Rest-stress MIBI myocardial scintigraphy was performed in 90 patients. Fifteen patients showed defects on rest image in spite of normal findings on stress image. Before and after removing the area of extra-cardiac MIBI accumulation on projection images, SPECT was reconstructed in the 15 patients. Perfusion defect on rest image improved in 66% of patients (10/15) and 37% of total segments (33/89) by removing the area of extra-cardiac MIBI accumulation. Furthermore, it was 21% (4/19), 38% (11/29), 43% (16/37) and 50% (2/4) in anterior, septum, posterior and lateral segments respectively. Significant MIBI extra-cardiac accumulation, especially in the gallbladder, is one of the causes of artificial defects on rest image. Thus, reconstruction of SPECT after removing area of MIBI extra-cardiac accumulation will be an appropriate method to improve the quality of MIBI images.
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Symptomatic Chiari malformation and associated pathophysiology in pediatric and adult patients without myelodysplasia. Neurol Med Chir (Tokyo) 1994; 34:738-43. [PMID: 7533267 DOI: 10.2176/nmc.34.738] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
The clinical characteristics of eight pediatric and five adult patients with Chiari malformation were evaluated. Six pediatric and five adult patients had associated syringomyelia. All patients initially underwent a suboccipital craniectomy with upper cervical (C-1 and/or C-2) laminectomy and duraplasty, and/or shunting procedures. The clinical characteristics of the pediatric and adult groups were compared. The mean interval between onset of symptoms and operation was shorter in the pediatric group (3 yrs 6 mos) than in the adult group (7 yrs 1 mo). Pediatric patients without syringomyelia had the shortest mean interval of 1 year 8 months. Preoperatively, the clinical features were more severe in the adult patients than in the pediatric patients. Postoperatively, seven of eight pediatric patients improved and one stabilized, while two of five adult patients improved, one stabilized, and in two the disease continued to progress despite multiple corrective procedures. Cine magnetic resonance imaging revealed correction of the abnormal cerebrospinal fluid (CSF) flow at the craniovertebral junction and decreased to-and-fro movement in the syrinx after posterior fossa decompression, which were closely correlated with the improvement of clinical features in pediatric patients. However, adult patients required further procedures because of the multifactorial nature of the disease. Evaluation of abnormal CSF pathways at the craniovertebral junction is important for investigating the pathogenesis of Chiari malformation and associated syringomyelia.
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[Findings on exercise thallium-201 scintigraphy of patients with vasospastic angina. Prediction of high risk cases]. NIHON RINSHO. JAPANESE JOURNAL OF CLINICAL MEDICINE 1994; 52 Suppl:265-9. [PMID: 12439978] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/27/2023]
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[Bathing in bed accelerates the recovery of skin temperature after ethanol-loading]. THE ANNALS OF PHYSIOLOGICAL ANTHROPOLOGY = SEIRI JINRUIGAKU KENKYUKAI KAISHI 1994; 13:49-54. [PMID: 8129834 DOI: 10.2114/ahs1983.13.49] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Bathing in bed (BB) is an essential nursing technique applied to patients with restricted physical abilities. The aim of this technique is to keep the functions of the skin as an external barrier and to prevent the patients from infection and decubitus. However, the effect of BB on the blood circulation of the skin has not yet been identified, and the data observed are controversial. We have evaluated the effects of BB on the blood circulation of the skin by use of thermography. BB was applied on the right side of the back (RB) in 6 healthy female subjects who exposed both sides of their back (RB and LB) at room temperature. Ethanol was applied on the 5 x 5 cm area of RB and LB after BB, and recovery of the skin temperature was observed. After BB, the average temperature of RB was significantly lower than that of LB. This shows that BB decreases temperature of the skin exposed in the air probably due to the supply of water by washcloth. Recovery of the skin temperature after the ethanol-loading was accelerated on RB. This indicates that BB facilitates the response of the blood vessels in the skin.
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[Late malfunction of the Björk-Shiley valve prosthesis due to Delrin disc defacement]. KYOBU GEKA. THE JAPANESE JOURNAL OF THORACIC SURGERY 1993; 46:1059-62. [PMID: 8230934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A 55-year-old woman eighteen years after mitral valvular replacement with Delrin disc Björk-Shiley valve prosthesis underwent a reoperation of prosthetic valve replacement for the prosthetic malfunction due to disc defacement. The patient suffered from faintness and vertigo at rest. An echocardiographic examination showed a moderate mitral insufficiency with a normal disc movement. Precise examination on the removed prosthesis revealed accelerated defacement of disc margin which made the ring-disc clearance up to 0.35 mm and strut-shaped groove formation on the inlet surface of the disc occluder. These findings suggested a pronouncedly earlier disc wear than predicted by Björk and co-workers. We concluded, therefore, that a patient undergone a valve replacement with Delrin disc Björk-Shiley valve should be examined periodically by echocardiography even though being without any symptoms.
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[A case report of BWG syndrome in an elderly patient performed with mitral valve replacement 11 years after single CABG]. KYOBU GEKA. THE JAPANESE JOURNAL OF THORACIC SURGERY 1993; 46:976-9. [PMID: 8230917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
A 46-year-old female who had undergone single CABG for BWG syndrome 11 years ago was referred to our hospital for paroxysmal atrial fibrillation. The roentgenogram showed slightly cardiomegaly and the enlargement of LA. Ischemic changes of ECG appeared at I, aVL, V5, V6, as inverted T wave, and low voltage R wave at V1-V4, but non Q wave. The thallium-201 emission computed tomogram at exercise revealed poor perfusion at apical region without redistribution pattern. Catheterization showed mitral regurgitation (grade III), big right coronary artery (RCA) arising from aorta, rich collateral to poor left coronary artery (LCA), and bypass graft was obstructed. The proximal end of LCA was closed, and didn't arise from both pulmonary artery and ascending aorta. In this cases, MVR only without re-CABG to LCA was selected and performed. Postoperative course was uneventful. The result of this case suggested that MVR was an effective surgical procedure for MR of BWG syndrome in the adult case and it was better to add CABG to LCA as much as possible if the ischemic region was large.
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[Scintigraphic comparison of graft patency between the left internal thoracic artery and saphenous vein graft after coronary bypass surgery]. KYOBU GEKA. THE JAPANESE JOURNAL OF THORACIC SURGERY 1993; 46:566-74. [PMID: 8336431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Graft patency after coronary bypass surgery (CABG) was evaluated with stress 201-thallium scintigraphy (stress 201Tl) in 26 cases, including 13 cases using the left internal thoracic artery (LITA group) in situ and 13 cases with saphenous vein graft (SVG group). All of them had effort or unstable angina caused by LAD lesion without apparent infarction. Stress 201Tl using a symptom-limited, graded bicycle exercise test was performed before CABG and 1 month, 6 months to 1 year, 1 year to 1.5 years after surgery. Five tomographic images including the apical side of the area fed by the bypass anastomosed to LAD in short axial sections were picked out and piled up. Fan-shaped ROI was made on this area and % Tl uptake was calculated using the following formula. 201Tl counts in ROI--Background counts/Maximum counts--Background counts x 100 (%) The normal % Tl uptake calculated in the control group (n = 11) in this ROI was 68.2 +/- 4.8%. Preoperative % Tl uptake showed 49.3 +/- 0.2% in the LITA group and 54.3 +/- 13.2% in the SVG group. % Tl uptake of the SVG group 1 month after CABG was slightly higher than that of the LITA group, (62.0 +/- 7.0% vs. 56.3 +/- 7.6%). However 6 months to 1 year after, % Tl uptake of the LITA group increased to 60.8 +/- 6.4%, inspite of a tendency on the decrease of that in the SVG group, (59.0 +/- 8.5%), and further more, 1 year to 1.5 years after CABG, increased to 62.3 +/- 5.1% near the normal % Tl uptake of the control group and the SVG group decreased to 58.8 +/- 6.8%. This result suggested that arterial in situ bypass graft might have an auto-regulation and "growing property" corresponding to flow demand, and this helps the excellent long-term patency of arterial bypass grafts.
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Responses of insulin-like growth factor binding protein-1 (IGFBP-1) and the IGFBP-3 complex to administration of insulin-like growth factor-I. ACTA ENDOCRINOLOGICA 1993; 128:101-8. [PMID: 7680831 DOI: 10.1530/acta.0.1280101] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The importance of insulin-like growth factor binding proteins (IGFBPs) in modulating the bioactivity of administered IGFs is poorly understood. This study examines responses of IGFBP-1 and the IGFBP-3 complex to recombinant human IGF-I. Eight fasted subjects received a single dose of 0.1-0.125 mg/kg IGF-I sc. This caused a 10-fold rise in IGFBP-1 over 6 h, falling rapidly after food intake. Peak (6-h) IGFBP-1 values were highly correlated with peak post-prandial (8-h) glucose values (r = 0.941). IGFBP-3 showed little response, decreasing slightly over the 48-h period following IGF-I. Adaptive changes in IGFBPs were studied in fed adults injected daily for 7 days with IGF-I, 0.1 mg/kg sc. Following the first injection, IGFBP-1 had a markedly blunted response compared to that in fasted subjects. However, after the seventh IGF-I injection, a 3.5-fold greater IGFBP-1 response to the same IGF-I dose was seen. Concomitantly with the increased IGFBP-1 responsiveness, mean immunoreactive IGFBP-3 and acid-labile subunit levels decreased significantly (p < 0.005), whereas IGFBP-2 detected by immunoblotting increased. Thus IGF-I administration causes changes in IGFBPs which may be important in regulating IGF-I bioavailability.
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Effects of insulin-like growth factor I or human growth hormone in fasted rats. GROWTH REGULATION 1992; 2:40-4. [PMID: 1486334] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
To study the effect of insulin-like growth factor I (IGF-I) treatment on growth and metabolism in fasted rats and compare it with the effect of human growth hormone (hGH), we infused 120 micrograms/ml IGF-I continuously or injected 200 micrograms hGH twice a day in fasted rats. After a 3 1/2-day administration of IGF-I in fasted rats, the body weights, kidney, spleen and adrenal gland weights were greater than those for untreated fasted rats (control). The body weights and the organ weights in hGH treated rats did not differ from those in control rats. Serum IGF-I levels in control, hGH treated and IGF-I treated rats were 64.0 +/- 6.1, 107.5 +/- 6.9 and 129.8 +/- 6.3 ng/ml, respectively, which were significantly different from each other. Blood urea nitrogen (BUN) levels were 13.9 +/- 1.1 ng/ml in IGF-I treated rats, which were significantly lower than those of control rats. Human GH treatment did not change BUN but affected nonesterified fatty acid (NEFA) and triglyceride. In IGF-I treated rats three-day urinary excretion of nitrogen and creatine were 163.5 +/- 14.6 mg and 9.53 +/- 1.53 mg, which were significantly less than those in control rats. These data indicate that IGF-I infusion inhibits body weight loss and catabolism in fasted rats and might be a useful therapy in catabolic conditions.
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