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Molecular phylogenetic analysis of Leibnitzia Cass.(Asteraceae:Mutisieae:Gerbera-complex),an Asian-North American disjunct genus

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Journal of Systematics and evolution 2010年第3期48卷 161-174页

作者： kristen e.baird Vicki A.FUNK Andrea WeeKS Department of environmental Science and Policy George Mason University US National Herbarium Smithsonian InstitutionMRC 166P.O.Box 371012WashingtonDC 20013-7012USA

Leibnitzia comprises six species of perennial herbs that are adapted to high elevation conditions and is one of only two Asteraceae genera known to have an exclusively disjunct distribution spanning central to eastern Asia and North America.Molecular phylogenetic analysis of Leibnitzia and other Gerbera-complex members indicates that Leibnitzia is monophyletic,which is in contrast with our expectation that the American Leibnitzia species L. lyrata and L.occimadrensis would be more closely related to another American member of the Gerbera-complex,namely Chaptalia.Ancestral area reconstructions show that the historical biogeography of the Gerbera-complex mirrors that of the entire Asteraceae,with early diverging lineages located in South America that were followed by transfers to Africa and eurasia and,most recently,to North America.Intercontinental transfer of Leibnitzia appears to have been directed from Asia to North America.Independent calibrations of nuclear(ribosomal DNA internal transcribed spacer region)and chloroplast(trnL-rpl32 intron)DNA sequence data using relaxed clock methods and either mean rate or fossil-based priors unanimously support Miocene and younger divergence times for Gerbera-complex taxa.The ages are not consistent with most Gondwanan vicariance episodes and,thus,the global distribution of Gerbera-complex members must be explained in large part by long-distance dispersal.American species of Leibnitzia are estimated to have diverged from their Asian ancestor during the Quaternary(ca.2 mya)and either migrated overland to North America via Beringia and retreated southwards along high elevation corridors to their present location in southwestern North America or were dispersed long distance.

关键词： Beringia biogeography Gerbera-complex Mutisieae.

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Poor maternal nutrition inhibits muscle development in ovine offspring

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Journal of Animal Science and Biotechnology 2015年第1期6卷 79-89页

作者： Sarah A Reed Joseline S Raja Maria L Hoffman Steven A Zinn kristen e Govoni Department of Animal Science University of ConnecticutStorrsCT 06269USA

Background： Maternal over and restricted nutrition has negative consequences on the muscle of offspring by reducing muscle fiber number and altering regulators of muscle growth. To determine if over and restricted maternal nutrition affected muscle growth and gene fed 60%, 100% or 140% of National Research Council and protein expression in offspring, 36 pregnant ewes were requirements from d 31 ＋ 1,3 of gestation until parturition. Lambs from control-fed （CON）, restricted-fed （ReS） or over-fed （OVeR） ewes were necropsied within 1 d of birth （n = 18） or maintained on a control diet for 3 mo （n = ] 5）. Semitendinosus muscle was collected for immunohistochemistry, and protein and gene expression analysis. Results： Compared with CON, muscle fiber cross-sectional area （CSA） increased in ReS （58%） and OVeR （47%） lambs at 1 d of age （P〈 0.01）; however at 3 mo, CSA decreased 15% and 17% compared with CON, respectively （P 〈 0.01）. Compared with CON, muscle lipid content was increased in OVeR （212.4%） and ReS （92.5%） at d 1 （P 〈 0.0001）. Muscle lipid content was increased 36.1% in OVeR and decreased 23.6% in ReS compared with CON at 3 mo （P 〈 0.0001）. At d 1, myostatin mRNA abundance in whole muscle tended to be greater in OVeR （P = 0.07） than CON. Follistatin mRNA abundance increased in OVeR （P = 0.04） and tended to increase in ReS （P = 0.06） compared with CON at d 1. However, there was no difference in myostatin or follistatin protein expression （P 〉 0.3）. Phosphorylated Akt （ser473） was increased in ReS at 3 mo compared with CON （P = 0.006）. Conclusions： In conclusion, maternal over and restricted nutrient intake alters muscle lipid content and growth of offspring, possibly through altered gene and protein expression.

关键词： Growth Maternal nutrition Muscle development Sheep

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Culture conditions for equine bone marrow mesenchymal stem cells and expression of key transcription factors during their differentiation into osteoblasts

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Journal of Animal Science and Biotechnology 2014年第2期5卷 163-172页

作者： elizabeth R A Glynn Alfredo Sanchez Londono Steven A Zinn Thomas A Hoagl kristen e Govoni Department of Animal Science University of Connecticut3636 Horsebarn Road Ext.Unit 4040StorrsCT 06269-4040USA Department of environmental and Population Health Tufts University North GraftonMA 01536USA

Background： The use of equine bone marrow mesenchymal stem cells （BMSC） is a novel method to improve fracture healing in horses. However, additional research is needed to identify optimal culture conditions and to determine the mechanisms involved in regulating BMSC differentiation into osteoblasts. The objectives of the experiments were to determine： 1） if autologous or commercial serum is better for proliferation and differentiation of equine BMSC into osteoblasts, and 2） the expression of key transcription factors during the differentiation of equine BMSC into osteoblasts. equine BMSC were isolated from the sterna of 3 horses, treated with purchased fetal bovine serum （FBS） or autologous horse serum （HS）, and cell proliferation determined. To induce osteoblast differentiation, cells were incubated with L-ascorbic acid-2-phosphate and glycerol-2-phosphate in the presence or absence of human bone morphogenetic protein2 （BMP2）, dexamethasone （DeX）, or combination of the two. Alkaline phosphatase （ALP） activity, a marker of osteoblast differentiation, was determined by eLISA. Total RNA was isolated from differentiating BMSC between d 0 to 18 to determine expression of runt-reloted tronscrJption foctor2 （Runx2）, osterix （Osx）, and T-box3 （Tbx3）. Data were analyzed by ANOVA. Results： Relative to control, FBS and HS increased cell number （133 ± 5 and 116 ± 5%, respectively; P 〈 0.001） and 5-bromo- 2＇-deoxyuridine （BrdU） incorporation （167 ± 6 and 120 ± 6%, respectively; P 〈 0.001）. Treatment with DeX increased ALP activity compared with control （1,638 ± 38%; P 〈 0.001）. In the absence and presence of Dex, BMP-2 did not alter ALP activity （P 〉 0.8）. Runt-reloted transcription foctor2 expression increased 3-fold （P 〈 0.001） by d 6 of culture. Osterix expression increased 94old （P 〈 0.05） by d 18 of culture. expression of Tbx3 increased 1.8-fold at d 3 （P 〈 0.01）; however expression was reduced 4-fold at d 18 （P 〈 0.01）. Conclusions： Dexamethasone, but not BMP-2, is required for differentiation of equine BMSC into osteo

关键词： Bone marrow mesenchymal stem cells Cell culture equine Osteoblasts Transcription factors

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Polymorphism of the endothelin-1 gene(rs5370)is a potential contributor to sickle cell disease pathophysiology

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Genes & Diseases 2016年第4期3卷 294-298页

作者： kristen G.Navarro Smith e.Agyingi Chinedu K.Nwabuobi Bolaji N.Thomas Department of Biomedical Sciences Rochester Institute of TechnologyRochesterNY14623USA Department of Obstetrics and Gynecology University of South FloridaTampaFLUSA

Sickle cell disease has been shown to demonstrate extensive variability in disease severity among and between individuals,the variability highlighted by differing genetic haplotypes.Despite the abundance of reports of functional significance due to polymorphisms of endothelial nitric oxide synthase(eNOS)and endothelin-1(eT-1)genes,the role of these polymorphisms in mediating sickle cell disease pathophysiology among African Americans is presently unclear.To deconvolute their potential significance among African Americans with sickle cell disease,we examined the genetic diversity and haplotype frequency of eNOS and eT-1 polymorphisms in disease(n Z 331)and control(n Z 379)groups,with a polymerase echain reaction restriction fragment length polymorphism assay.We report that genotypic and allelic frequencies of eNOS variants are not significantly different between groups.eNOS homozygote mutants,which had been shown to have clinical significance elsewhere,showed no statistical significance in our study.On the other hand,and contrary to previous report among Africans with sickle cell disease,the endothelin-1 homozygous mutant variant showed significant difference in genotypic(p Z 2.84e-12)and allelic frequencies(p Z 2.20e-16)between groups.The most common haplotype is the combination of T786C homozygote wildtype variant with homozygote mutant variants of G5665T(eT-1)and Glu298Asp(eNOS).These results show that endothelin-1(rs5370)polymorphism,rather than endothelial nitric oxide synthase polymorphism might play a significant role in disease severity or individual clinical outcomes among African Americans with sickle cell disease.This would have profound implications for designing and/or advancing personalized care for sickle cell patients and relieving disease complications.

关键词： endothelial nitric oxide synthase endothelin-1 Pathophysiology Polymorphisms Sickle cell disease

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SWeeT as Sugar： New Sucrose effluxers in Plants

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Molecular Plant 2012年第4期5卷 766-768页

作者： R. Frank Baker kristen A. Leach David M. Braun Division of Biological Sciences Interdisciplinary Plant Group Missouri Maize Center University of Missouri 110 Tucker Hall Columbia MO 65211

Photosynthesis leads to the fixation of carbon in leaves and to the accumulation of carbohydrates （e.g., sucrose, starch）. This assimilated carbon must be transported from the leaves （source tissues） to non-photosynthetic organs （sink tissues）, such as roots and seeds. Despite the essentiality of this process in plants, a complete understanding of the actors involved in sucrose export from leaves is lacking. SWeeT proteins are a newly identified class of sugar transporters that facilitate dif- fusion of sugars across cell membranes down a concentration gradient. In this perspective, we highlight the recent publica- tion of Chen et al. （2012）, which reports that SWeeT proteins transport sucrose across cell membranes, are expressed in a subset of phloem parenchyma cells,

关键词： DISeASe-SUSCePTIBILITY GeNe BACTeRIAL-BLIGHT TRANSPORTeRS RICe ReSISTANCe ROLeS

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Oxidative stress in alcohol-related liver disease

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World Journal of Hepatology 2020年第7期12卷 332-349页

作者： Huey K Tan euan Yates kristen Lilly Ashwin D Dhanda Hepatology Research Group Institute of Translational and Stratified MedicineFaculty of HealthUniversity of PlymouthPlymouth PL68BUUnited Kingdom South West Liver Unit University Hospitals Plymouth NHS TrustPlymouth PL68DHUnited Kingdom Department of Clinical Immunology University Hospitals Plymouth NHS TrustPlymouth PL68DHUnited Kingdom

Alcohol consumption is one of the leading causes of the global burden of disease and results in high healthcare and economic costs.Heavy alcohol misuse leads to alcohol-related liver disease,which is responsible for a significant proportion of alcohol-attributable deaths globally.Other than reducing alcohol consumption,there are currently no effective treatments for alcohol-related liver disease.Oxidative stress refers to an imbalance in the production and elimination of reactive oxygen species and antioxidants.It plays important roles in several aspects of alcohol-related liver disease pathogenesis.Here,we review how chronic alcohol use results in oxidative stress through increased metabolism via the cytochrome P4502e1 system producing reactive oxygen species,acetaldehyde and protein and DNA adducts.These trigger inflammatory signaling pathways within the liver leading to expression of pro-inflammatory mediators causing hepatocyte apoptosis and necrosis.Reactive oxygen species exposure also results in mitochondrial stress within hepatocytes causing structural and functional dysregulation of mitochondria and upregulating apoptotic signaling.There is also evidence that oxidative stress as well as the direct effect of alcohol influences epigenetic regulation.Increased global histone methylation and acetylation and specific histone acetylation inhibits antioxidant responses and promotes expression of key pro-inflammatory genes.This review highlights aspects of the role of oxidative stress in disease pathogenesis that warrant further study including mitochondrial stress and epigenetic regulation.Improved understanding of these processes may identify novel targets for therapy.

关键词： Alcohol-related liver disease Alcoholic hepatitis Oxidative stress Reactive

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Phase 3 trial of first generation protease inhibitor therapy for hepatitis C virus/human immunodeficiency virus coinfection

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World Journal of Hepatology 2017年第4期9卷 217-223页

作者： Kenneth e Sherman Minhee Kang Richard Sterling Triin Umbleja kristen Marks Jennifer J Kiser Beverly Alston-Smith Wayne Greaves Adeel A Butt 无 Division of Digestive Diseases University of Cincinnati College of Medicine harvard T.h. Chan School of Public health Department of Gastroenterology Virginia Commonwealth University Division of Infectious Disease Weill Cornell Medical School University of Colorado School of Pharmacy NIAID-Division of AIDS Merck and Co Inc. University of Pittsburgh School of Medicine hamad healthcare Quality Institute the ACTG 5294 BIRTH Study Team

AIM To evaluate efficacy/safety of hepatitis C virus(HCV) protease inhibitor boceprevir with pegylated interferon(PeG-IFN) alfa and weight-based ribavirin(RBV) in a phase 3 trial. MeTHODS A prospective, multicenter, phase 3, open-label, singlearm study of PeG-IFN alfa, weight-based RBV, and boceprevir, with a PeG-IFN/RBV lead-in phase was performed. The HCV/human immunodeficiency virus coinfected study population included treatment na?ve(TN) and treatment experienced(Te) patients. Treatment duration ranged from 28 to 48 wk dependent upon response-guided criteria. All patients had HCV Genotype 1 with a viral load > 10000 IU/ml. Compensated cirrhosis was allowed. Sample size was determined to establish superiority to historical(PeG-IFN plus RBV) rates in sustained viral response(SVR). ReSULTS A total of 257 enrolled participants were analyzed(135 TN and 122 Te). In the TN group, 81.5% were male and 54.1% were black. In the Te group, 76.2% were male and 47.5% were white. Overall SVR12 rates(HCV RNA er limit of quantification, target not detected, target not detected) were 35.6% in TN and 30.3% in Te. Response rates at SVR24 were 28% in TN and 10% in Te, and exceeded those in historical controls. The highest rate was observed in TN non-cirrhotic participants(36.8% and the lowest in Te cirrhotics(26.3%). Cirrhotic TN participants had a 27.8% SVR12 rate and 32.1% of Te non-cirrhotics achieved SVR12. Significantly lower response rates were observed among black participants; in the Te, SVR12 was 39.7% in white participants but only 13.2% of black subjects(P = 0.002). Among the TN, SVR12 was 42.1% among whites and 27.4% among blacks(P = 0.09). CONCLUSION The trial met its hypothesis of improved SVR compared to historical controls but overall SVR rates were low. All-oral HCV treatments will mitigate these difficulties.

关键词：人的免疫不全病毒丙肝病毒 Boceprevir Pegylated 干扰素 A Ribavirin

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The estrogen metabolite 2-methoxyestradiol regulates eukaryotic initiation factor 4e(eIF4e)and inhibits protein synthesis in MG63 osteosarcoma cells

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Genes & Diseases 2016年第2期3卷 153-158页

作者： Avudaiappan Maran kristen L.Shogren Michael J.Yaszemski Department of Orthopedics Mayo ClinicRochesterMN 55905USA

Osteosarcoma is a primary bone tumor that affects children and young adults.The estrogen metabolite 2-methoxyestradiol(2-Me)induces cell death in osteosarcoma cells.To determine whether 2-Me actions involve the control of protein synthesis,we studied the effect of 2-Me on eukaryotic initiation factor 4e(eIF4e)and eIF4e-binding protein 1(4e-BP1)in MG63 osteosarcoma cells.Our results show that 2-Me treatment increases the association of eIF4e with 4e-BP1 in osteosarcoma cells.Also,2-Me decreases the binding of eIF4e protein to 7-methyl-guanosine cap structure,indicating that 2-Me treatment results in the inhibition of translational initiation.These findings are further supported by the inhibition of protein synthesis in 2-Me-treated osteosarcoma cells.Taken together,our studies show that 2-Me-mediated antitumor effects in osteosarcoma cells involve the regulation of protein synthesis,and translational machinery could serve as a target in the treatment of osteosarcoma.

关键词： 2-Methoxyestradiol 4e-BP estrogen metabolite eIF4e Osteosarcoma

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enhanced disinfection of escherichia coli and bacteriophage MS2 in water using a copper and silver loaded titanium dioxide nanowire membrane

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Frontiers of environmental Science & engineering 2016年第4期10卷 71-79页

作者： Guiying RAO kristen S. BRASTAD Qianyi ZHANG Rebecca ROBINSON Zhen He Ying LI Department of Mechanical engineering Texas A&M University College Station TX 77843 USA Department of Mechanical engineering University of Wisconsin-Milwaukee Milwaukee WI 53211 USA A.O. Smith Corporate Technology Center Milwaukee WI 53224 USA Department of Civil and environmental engineering Virginia Polytechnic Institute and State University Blacksburg VA 24061 USA

Titanium dioxide （TiO2） is a widely used photocatalyst that has been demonstrated for microorganism disinfection in drinking water. In this study, a new material with a novel structure, silver and copper loaded TiO2 nanowire membrane （Cu-Ag-TiO2） was prepared and evaluated for its efficiency to inactivate e. coli and bacteriophage MS2. enhanced photo-activated bactericidal and virucidal activities were obtained by the Cu-Ag-TiO2 membrane than by the TiO2, Ag-TiO2 and Cu-TiO2 membranes under both dark and UV light illumination. The better performance was attributed to the synergies of enhanced membrane photoacfivity by loading silver and copper on the membrane and the synergistic effect between the free silver and copper ions in water. At the end of a 30 min test of dead- end filtration under 254 nm UV irradiation, the Cu-Ag-TiO2 membrane was able to obtain an e. coli removal of 7.68 log and bacteriophage Ms2 removal of 4.02 log, which have met the US ePA standard. The free metal ions coming offthe membrane have concentrations of less than 10 ppb in the water effluent, far below the US ePA maximum contaminant level for silver and copper ions in drinking water. Therefore, the photo-activated disinfection by the Cu-Ag-Ti02 membrane is a viable technique for meeting drinking water treatment standards of microbiological water purifiers.

关键词： Photo-activated disinfection Titanium dioxide Nanowire membrane Silver Copper

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Phylogeography and morphometric variation in the Cinnamon Hummingbird complex:Amazilia rutila(Aves:Trochilidae)

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Avian Research 2021年第4期12卷 509-525页

作者： Melisa Vázquez-López Nandadevi Córtes-Rodríguez Sahid M.Robles-Bello Alfredo Bueno-Hernández Luz e.Zamudio-Beltrán kristen Ruegg Blanca e.Hernández-Baños Museo de Zoología Facultad de CienciasUniversidad Nacional Autónoma de MéxicoApartado Postal04510 Mexico CityMexico Department of Biology Ithaca CollegeIthacaNY 14850USA Museo de Zoología Facultad de Estudios Superiores ZaragozaUniversidad Nacional Autónoma de MéxicoMexico CityMexico Department of Biology Colorado State UniversityFort CollinsCO 80523USA

Background:The Mesoamerican dominion is a biogeographic area of great interest due to its complex topography and distinctive climatic history.This area has a large diversity of habitats,including tropical deciduous forests,which house a large number of endemic species.Here,we assess phylogeographic pattern,genetic and morphometric variation in the Cinnamon Hummingbird complex Amazilia rutila,which prefers habitats in this region.This resident species is distributed along the Pacific coast from Sinaloa—including the Tres Marías Islands in Mexico to Costa Rica,and from the coastal plain of the Yucatán Peninsula of Mexico south to Belize.Methods:We obtained genetic data from 85 samples of A.rutila,using 4 different molecular markers(mtDNA:ND2,COI;nDNA:ODC,MUSK)on which we performed analyses of population structure(median-joining network,STRU CTU Re,FST,AMOVA),Bayesian and Maximum Likelihood phylogenetic analyses,and divergence time estimates.In order to evaluate the historic suitability of environmental conditions,we constructed projection models using past scenarios(Pleistocene periods),and conducted Bayesian Skyline Plots(BSP)to visualize changes in population sizes over time.To analyze morphometric variation,we took measurements of 5 morphological traits from 210 study skins.We tested for differences between sexes,differences among geographic groups(defined based on genetic results),and used PCA to examine the variation in multivariate space.Results:Using mtDNA,we recovered four main geographic groups:the Pacific coast,the Tres Marías Islands,the Chiapas region,and the Yucatán Peninsula together with Central America.These same groups were recovered by the phylogenetic results based on the multilocus dataset.Demography based on BSP results showed constant population size over time throughout the A.rutila complex and within each geographic group.ecological niche model projec-tions onto past scenarios revealed no drastic changes in suitable conditions,but revealed some possible refuges.Mor-phometric results showed m

关键词： Amazilia rutila Genetic structure Genetic variation Phylogeography Tres Marías Islands Trochilidae Tropical deciduous forest

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