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Hypoxia-inducible factor 2α is a negative regulator of osteoblastogenesis and bone mass accrual

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bone Research 2019年第1期7卷 91-104页

作者： Christophe Merceron Kavitha Ranganathan Elizabeth Wang zachary Tata Shreya Makkapati Mohd Parvez Khan Laura Mangiavini Angela Qing Yao Laura Castellini benjamin Levi Amato J.Giaccia Ernestina Schipani Department of Orthopaedic Surgery School of MedicineUniversity of MichiganAnn ArborMIUSA Division of Plastic and Reconstructive Surgery Department of SurgeryUniversity of MichiganAnn ArborMIUSA Department of Radiation Oncology Stanford University Medical SchoolStanfordCAUSA

Osteoblasts,which are the bone-forming cells,operate in a hypoxic *** transcription factors hypoxia-inducible factor-1α(HIF1)and HIF2 are key mediators of the cellular response to *** are expressed in ***1 is known to be a positive regulator of bone ***,the role of HIF2 in the control osteoblast biology is still poorly *** this study,we used mouse genetics to demonstrate that HIF2 is an inhibitor of osteoblastogenesis and bone mass ***,we provided evidence that HIF2 impairs osteoblast differentiation at least in part,by upregulating the transcription factor *** findings constitute a paradigm shift,as activation of the hypoxia-signaling pathway has traditionally been associated with increased bone formation through *** HIF2 could thus represent a therapeutic approach for the treatment of the low bone mass observed in chronic diseases,osteoporosis,or aging.

关键词： is cells has

Potential impacts of UV exposure on lichen communities:a pilot study of Nothofagus dombeyi trunks in southernmost Chile

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Ecosystem Health and Sustainability 2015年第4期1卷 40-52页

作者： Marie T.Trest Susan Will-Wolf Rachel Keuler Nathaniel Shay Karen Hill Alyssa Studer Andy Muench zachary Alexander Axel Adams Leah Dittberner Martin Feehan Hannah Lee Nicholas Galleguillos-Katz Joy b.Zedler Linda Graham Patricia Arancibia-Avila Department of botany University of WisconsinMadisonWisconsin 53706 USA Department of basic Sciences University of Bio-BioChillan 3800708 Chile

High-latitude terrestrial ecosystems face the triple threats of climate warming,increased exposure to UV arising from polar ozone depletion,and *** communities of southernmost Chile are recognized for their high diversity,which includes nitrogen-fixing *** lichens are common on forest trees,contribute nitrogen to forests,and are sensitive to exposure following deforestation(widespread in this region).In a pilot study of exposure effects on tree lichens,using nondestructive imaging methods,we compared lichen communities on trunks of isolated *** tree trunks of southern Chilean beech(Nothofagus dombeyi,Nothofagaceae).We chose trees of similar diameter and trunk lean angle in conserved forest and nearby logged meadow on Navarino Island,XII Region Magallanes and Chilean Antarctica,Chile,within the annual southern ozone ***-five percent of cyanolichen records,including Nephroma antarcticum,and 66%of records for other foliose lichens were from the forest,whereas pendulous usneoid lichens dominated *** bark at the meadow *** of cyanolichen growth on isolated trees could affect ecosystem function in this poorly studied *** factors contributing to strong community differences were increased light intensity,UV radiation,and wind stress,plus limited ability of lichens to colonize isolated trees in the logged *** radiation was likely an important stressor for some lichen species but not *** recommend more extensive monitoring to pinpoint causes of differing lichen communities,and we encourage better protection of bark-dwelling lichens in southern hemisphere regions facing multiple threats.

关键词： bark lichens Chile cyanolichens deforestation forest fragmentation lichen diversity Nothofagus dombeyi southern ozone hole UV radiation

Lipopolysaccharide Modified Liposomes for Amyotropic Lateral Sclerosis Therapy: Efficacy in SOD1 Mouse Model

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Advances in Nanoparticles 2012年第3期1卷 44-53页

作者： Nicholas J. Wiley A. b. Madhankumar Ryan M. Mitchell Elizabeth b. Neely Elias Rizk Gregory L. Douds zachary Simmons James R. Connor Department of Neurology Pennsylvania State University College of Medicine/Milton S. Hershey Medical Center Hershey USA George M. Leader Family Laboratory Department of Neurosurgery Pennsylvania State University College of Medicine/Milton S. Hershey Medical Center Hershey USA

Activation of microglia is a histological feature observed in neurodegenerative diseases like ALS. The oral administration of minocycline has been demonstrated to have minimal neuroprotection ability in the animal models and is also associated with inadvertent toxicity due to non-specific oral absorption of the drug. Nonetheless, the drug itself shows promise in a number of disease models suggesting it could be effective if delivered optimally. Thus, we utilized LPS modified liposomes to target TLR4 receptor on the microglia in SOD1G93A mice and compared its efficacy with non- targeted nanoliposomes. The in vitro results indicate that targeting the TLR4 receptor on microglia significantly increases (p G93A mouse model of ALS, targeted and non-targeted minocycline treatment significantly increased (p G93A mice, the non- targeted nanovesicles significantly increased the latency to rotarod failure and both targeted and non-targeted nanovesicles significantly delayed disease endpoints.

关键词： Amyotrophic Lateral Sclerosis Minocycline Liposomes Microglia TLR4 Lipopolysaccharides

Gastric intestinal metaplasia development in African American predominant United States population

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World Journal of Gastrointestinal Endoscopy 2022年第10期14卷 597-607页

作者： Akram I Ahmad Arielle Lee Claire Caplan Colin Wikholm Ioannis Pothoulakis Zaynab Almothafer NishthaRaval Samantha Marshall Ankit Mishra Nicole Hodgins In Guk Kang Raymond K Chang zachary Dailey Arvin Daneshmand Anjani Kapadia Jae Hak Oh brittney Rodriguez Abhinav Sehgal Matthew Sweeney Christopher b Swisher Daniel F Childers Corinne O'Connor Lynette M Sequeira Won Cho Department of Internal Medicine MedStar Washington Hospital CenterWashingtonDC 20010United States Department of Internal Medicine Georgetown University School of MedicineWashingtonDC 20007United States Department of Gastroenterology and Hepatology INOVA Medical SystemLeesburgVA 20176United States

bACKGROUND Gastric cancer significantly contributes to cancer mortality *** intestinal metaplasia(GIM)is a stage in the Correa cascade and a premalignant lesion of gastric *** natural history of GIM formation and progression over time is not fully ***,there are no clear guidelines on GIM surveillance or management in the United *** To investigate factors associated with GIM development over time in African American-predominant study *** This is a retrospective longitudinal study in a single tertiary hospital in Washington *** retrieved upper esophagogastroduodenoscopies(EGDs)with gastric biopsies from the pathology department database from January 2015 to December *** included in the study had undergone two or more EGDswith gastric *** with no GIM at baseline were followed up until they developed GIM or until the last available *** criteria consisted of patients agebased on GIM *** and multivariate Cox regression was used to estimate the hazard induced by patient demographics,EGD findings,and Helicobacter pylori(***)status on the GIM *** Of 2375 patients who had at least 1 EGD with gastric biopsy,579 patients were included in the study.138 patients developed GIM during the study follow-up period of 1087 d on average,compared to 857 d in patients without GIM(P=0.247).The average age of GIM group was 64 years compared to 56 years in the non-GIM group(Pby 4%(Pbse

关键词： Gastric intestinal metaplasia Gastric cancer Helicobacter pylori Retrospective longitudinal study Esophagogastroduodenoscopy African American population

NKR-P1b expression in gut-associated innate lymphoid cells is required for the control of gastrointestinal tract infections

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Cellular & Molecular Immunology 2019年第11期16卷 868-877页

作者： Elias Abou-Samra zachary Hickey Oscar A.Aguilar Michal Scur Ahmad bakur Mahmoud Sergey Pyatibrat Megan M.Tu Jeffrey Francispillai Arthur Mortha James R.Carlyle Mir Munir A.Rahim Andrew P.Makrigiannis Department of biochemistry Microbiology and ImmunologyUniversity of Ottawa451 Smyth RoadOttawaON K1H 8M5Canada Department of Immunology University of Toronto1 King’s College CircleTorontoON M5S 1A8Canada Sunnybrook Research Institute 2075 Bayview AvenueTorontoON M4N 3M5Canada Department of Microbiology and Immunology Dalhousie University5850 College StreetHalifaxNS B3H 4R2Canada College of Applied Medical Sciences Taibah UniversityMadinah MunawwarahSaudi Arabia Division of Anatomical Pathology Department of Pathology and Laboratory MedicineThe Ottawa HospitalUniversity of Ottawa501 Smyth RoadOttawaON K1H 8L6Canada

Helper-type innate lymphoid cells(ILC)play an important role in intestinal *** of the NKR-P1 gene family are expressed in various innate immune cells,including natural killer(NK)cells,and their cognate Clr ligand family members are expressed in various specialized tissues,including the intestinal epithelium,where they may play an important role in mucosalassociated innate immune *** this study,we show that the inhibitory NKR-P1b receptor,but not the Ly49 receptor,is expressed in gut-resident NK cells,ILC,and a subset ofγδT cells in a tissue-specific ***3 cells constitute the predominant cell subset expressing NKR-P1b in the gut lamina *** known NKR-P1b ligand Clr-b is broadly expressed in gut-associated cells of hematopoietic *** genetic deletion of NKR-P1b results in a higher frequency and number of ILC3 andγδT cells in the gut lamina ***,the function of gut-resident ILC3,NK,andγδT cells in NKR-P1b-deficient mice is impaired during gastrointestinal tract infection by Citrobacter rodentium or Salmonella typhimurium,resulting in increased systemic bacterial dissemination in NKR-P1b-deficient *** findings highlight the role of the NKR-P1b:Clr-b recognition system in the modulation of intestinal innate immune cell functions.

关键词： Innate lymphoid cells Natural killer cells Gut-associated immune cells NKR-P1b receptor Innate immunity

Microbial Compositions and Enzymes of a Forest Ecosystem in Alabama: Initial Response to Thinning and burning Management Selections

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Open Journal of Forestry 2018年第3期8卷 328-343页

作者： Fritz A. Ntoko Terrence G. Gardner zachary N. Senwo Veronica Acosta-Martinez Department of biological and Environmental Sciences College of Agricultural Life and Natural Sciences Alabama A & M University Normal AL USA Department of Soil Science North Carolina State University Raleigh NC USA USDA-ARS Cropping Systems Research Laboratory Wind Erosion and Water Conservation Unit Lubbock TX USA

Prescribed burning and tree thinning are commonly used restoration practices for US forests management to increase forest productivity and enhance plant and animal diversity. The impact of these practices in Alabama’s bankhead National Forest (bNF) to soil microbial components and overall forest soil health are unknown. We hypothesized that microbial assemblages and enzyme activities are continuously changing in forest ecosystems especially due to management selections. Therefore, the objective of this study was to assess changes in microbial community compositions (fungal vs bacterial populations) via fatty acid methyl ester (FAME) profiling and several enzyme activities (β-glucosaminidase, acid phosphatase, arylsulfatase, β-glucosidase, xylanase, laccase, and manganese peroxidase) critical to soil organic matter (SOM) dynamics and biogeochemical cycling. In this forest, heavily-thinned plots without burning or less frequent burning treatments seemed to provide more favorable conditions (higher pH and lower C:N ratios) for C and N mineralization. This may explain a slight increase (by 12%) detected in fungi:bacteria (F:b) ratio in the heavily-thinned plots relative to the control. Thinned (lightly and heavily) plots showed greater ligninolytic (laccase and MnP) activities and lower β-glucosidase and β-glucosaminidase activities compared to the no-thinned plots probably due to increase depositions of woody recalcitrant C materials. We observed significant but negative correlations between the ligninolytic laccase and manganese peroxidase (Lac and MnP) enzymes respectively, with MbC (?0.45* and ?0.68** respectively) and MbN (?0.43* and ?0.65** respectively). Prescribed burning treatment reduced microbial biomass C and N of the 9-yr burned plot/lightly thinned plotsprobably due to depletion of labile C sources with the high temperatures, leaving mostly recalcitrant C sources as available soil substrates. Gram-positive bacteria (i15:0, a15:0, i17:0, and a17:0), actinom

关键词： Forest Soil Health Forest Ecosystems Microbial Compositions Enzyme Metabolisms Thinning and burning

buffer standards for the physiological pH of the zwitterionic buffer 3-[<i>N</i>-tris(hydroxymethyl)methylamino]-2-hydroxypropanesulfonic Acid (TAPSO) From (278.15 to 328.15) K

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Journal of biophysical Chemistry 2011年第4期2卷 414-421页

作者： Lakshmi N. Roy Rabindra N. Roy blake M. bodendorfer zachary M. Downs Stephen D. Rocchio Jessica M. Stegner Isaac b. Henson 不详

The second dissociation constant, pK2, and related thermodynamic quantities for TAPSO have been previously determined and reported from the temperatures (278.15 to 328.15) K. In the current study there are five buffer solutions without NaCl and five buffer solutions with NaCl present which yield an ionic strength (I = 0.16 mol·kg-1) similar to that of blood plasma. These buffer solutions have been evaluated in the temperature range of (278.15 to 328.15) K using the extended Debye-Hückel equation, due to the limitations of the bates-Guggenheim convention such that it is only valid when I -1. The liquid junction potential (Ej) values between the TAPSO solution and the saturated KCl calomel electrode solution have been estimated at (298.15 and 310.15) K using a flowing junction cell measurement. The previously mentioned Ej values have been used in determining the operational pH values at (298.15 and 310.15) K. These TAPSO buffer solutions are recommended as reference solutions for pH measurements in saline media with an ionic strength of I = 0.16 mol·kg-1.

关键词： Zwitterionic buffer pH Liquid Junction Physiological

biodegradation and Sugar Release from Canola Plant biomass by Selected White Rot Fungi

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Advances in biological Chemistry 2014年第6期4卷 395-406页

作者： Omoanghe S. Isikhuemhen Nona A. Mikiashvili zachary N. Senwo Elijah I. Ohimain Department of Natural Resources & Environmental Design North Carolina A&T State University Greensboro USA Department of biological & Environmental Sciences Alabama Agricultural & Mechanical University Normal USA Niger Delta University Wilberforce Island Nigeria

Canola crop is rich in plant biomass. It is considered a major cash crop in North America and a potential source for biofuel. We evaluated six strains of white rot basidiomycetes under solid state fermentation (SSF) for their potentials to secrete oxidative and hydrolytic enzymes to biodegrade canola plant biomass (CPb), and release sugars. Fuscoporia gilva and Pleurotus tuberregium produced high amount of laccase (440.86 U/L and 480.63 U/L at day 7), as well as carboxylmethylcellulase (CMCase) (4.78 U/mL at day 21 and 3.13 U/mL at day 14) and xylanase (4.48 U/mL and 7.8 U/mL at day 21), respectively. bjerkandera adusta showed high amount of MnP (50.4 U/L) and peroxidase (64.5 U/L), relative to the other strains. Loss of organic matter peaked after 21 days of incubation in all the tested strains;however, the best result (34.0%) was shown in P. tuberregium. The highest lignin loss was observed in Coriolopsis caperata strains. Among the sugar polymers, hemicellulose was highly degraded by P. tuberregium and P. pulmonarius (4.1% - 4.6%), while cellulose (3.3% - 4.3%) was mainly degraded by F. gilva and b. adusta. Glucose was the dominant sugar released by all the fungi tested, with the highest concentration of 1.25 mg/mL produced by b. adusta at day 14 of incubation. Results indicate that selected white rot fungi can achieve significant delignification of CPb within 14 days of solid state fermentation. Their importance in low cost pretreatment of lignocellulosic biomass prior to conversion into biofuels and bio-products of economic importance is discussed.

关键词： Canola Plant biomass bio-Delignification White Rot Fungi Lignocellulose

Investigational growth factors utilized in animal models of spinal fusion: Systematic review

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World Journal of Orthopedics 2019年第4期10卷 176-191页

作者： Ethan Cottrill A Karim Ahmed Noah Lessing zachary Pennington Wataru Ishida Alexander Perdomo-Pantoja Sheng-fu Lo Elizabeth Howell Christina Holmes C Rory Goodwin Nicholas Theodore Daniel M Sciubba Timothy F Witham Department of Neurosurgery The Johns Hopkins Hospital Department of Neurosurgery Duke University Medical Center

bACKGROUND Over 400000 Americans annually undergo spinal fusion surgeries, yet up to 40%of these procedures result in pseudoarthrosis even with iliac crest autograft, the current "gold standard" treatment. Tissue engineering has the potential to solve this problem via the creation of bone grafts involving bone-promoting growth factors(e.g., bone morphogenetic protein 2). A broad assessment of experimental growth factors is important to inform future work and clinical potential in this area. To date, however, no study has systematically reviewed the investigational growth factors utilized in preclinical animal models of spinal *** To review all published studies assessing investigational growth factors for spinal fusion in animal models and identify promising agents for *** We conducted a systematic review of the literature using PubMed, Embase,Cochrane Library, and Web of Science databases with searches run on May 29 th,2018. The search query was designed to include all non-human, preclinical animal models of spinal fusion reported in the literature without a timespan limit. Extracted data for each model included surgical approach, level of fusion,animal species and breed, animal age and sex, and any other relevant characteristics. The dosages/sizes of all implant materials, spinal fusion rates,and follow-up time points were recorded. The data were analyzed and the results reported in tables and text. PRISMA guidelines were followed for this systematic *** Twenty-six articles were included in this study, comprising 14 experimental growth factors: Ab204(n = 1); angiopoietin 1(n = 1); calcitonin(n = 3);erythropoietin(n = 1); basic fibroblast growth factor(n = 1); growth differentiation factor 5(n = 4), combined insulin-like growth factor 1 +transforming growth factor beta(n = 4); insulin(n = 1); NELL-1(n = 5); noggin(n= 1); P-15(n = 1); peptide b2 A(n = 2); and secreted phosphoprotein 24(n = 1).The fusion rates of the current gold sta

关键词： Spinal fusion Growth factor Pseudoarthrosis Systematic review