检索结果-南通市图书馆

Development of a surgical procedure for removal of a placentome from a pregnant ewe during gestation

在线全文

学校读者我要写书评

暂无评论

Journal of Animal Science and Biotechnology 2020年第4期11卷 986-992页

作者： Colleen A.Lambo Ashley K.Edwards Fuller W.Bazer kathrin dunlap M.Carey Satterfield Veterinary Physiology and Pharmacology College of Veterinary Medicine and Biomedical Sciences Texas A&M UniversityCollege StationTX 77843USA Department of Animal Science Texas A&M University2471 TAMUCollege StationTX 77843USA.

Background: In recent decades, there has been a growing interest in the impact of insults during pregnancy on postnatal health and disease. It is known that changes in placental development can impact fetal growth and subsequent susceptibility to adult onset diseases;however, a method to collect sufficient placental tissues for both histological and gene expression analyses during gestation without compromising the pregnancy has not been described. The ewe is an established biomedical model for the study of fetal development. Due to its cotyledonary placental type, the sheep has potential for surgical removal of materno-fetal exchange tissues, i.e., placentomes. A novel surgical procedure was developed in well-fed control ewes to excise a single placentome at ***: A follow-up study was performed in a cohort of nutrient-restricted ewes to investigate rapid placental changes in response to undernutrition. The surgery averaged 19 min, and there were no viability differences between control and sham ewes. Nutrient restricted fetuses were smaller than controls(4.7 ± 0.1 kg vs. 5.6 ± 0.2 kg;P < 0.05), with greater dam weight loss(-32.4 ± 1.3 kg vs. 14.2 ± 2.2 kg;P < 0.01), and smaller placentomes at necropsy(5.7 ± 0.3 g vs. 7.2 ± 0.9 g;P < 0.05). Weight of sampled placentomes and placentome numbers did not ***: With this technique, gestational studies in the sheep model will provide insight into the onset and complexity of changes in gene expression in placentomes resulting from undernutrition(as described in our study),overnutrition, alcohol or substance abuse, and environmental or disease factors of relevance and concern regarding the reproductive health and developmental origins of health and disease in humans and in animals.

关键词： Developmental biology Fetal development IUGR Ovine/sheep Placenta Placental transport

Uterine biology in pigs and sheep

在线全文

学校读者我要写书评

暂无评论

Journal of Animal Science and Biotechnology 2012年第3期3卷 109-129页

作者： Fuller W Bazer Gwonhwa Song Jinyoung Kim kathrin A dunlap Michael Carey Satterfield Gregory A Johnson Robert C Burghardt Guoyao Wu Department of Animal Science 442D Kleberg Center 2471 TAMU Texas A&M University College Station TX 77843-2471 USA Department of Veterinary Integrated Biosciences Texas A&M University College Station TX 77843-2471 USA

There is a dialogue between the developing conceptus （embryo-fetus and associated placental membranes） and maternal uterus which must be established during the peri-implantation period for pregnancy recognition signaling, implantation, regulation of gene expression by uterine epithelial and stromal cells, placentation and exchange of nutrients and gases. The uterus provide a microenvironment in which molecules secreted by uterine epithelia or transported into the uterine lumen represent histotroph required for growth and development of the conceptus and receptivity of the uterus to implantation. Pregnancy recognition signaling mechanisms sustain the functional lifespan of the corpora lutea （CL） which produce progesterone, the hormone of pregnancy essential for uterine functions that support implantation and placentation required for a successful outcome of pregnancy. It is within the peri-implantation period that most embryonic deaths occur due to deficiencies attributed to uterine functions or failure of the conceptus to develop appropriately, signal pregnancy recognition and/or undergo implantation and placentation. With proper placentation, the fetal fluids and fetal membranes each have unique functions to ensure hematotrophic and histotrophic nutrition in support of growth and development of the fetus. The endocrine status of the pregnant female and her nutritional status are critical for successful establishment and maintenance of pregnancy. This review addresses the complexity of key mechanisms that are characteristic of successful reproduction in sheep and pigs and gaps in knowledge that must be the subject of research in order to enhance fertility and reproductive health of livestock species.

关键词： Genes Growth factors Interferon stimulated Pregnancy Pregnancy recognition Uterus

Functional roles of ornithine decarboxylase and arginine decarboxylase during the peri-implantation period of pregnancy in sheep

在线全文

学校读者我要写书评

暂无评论

Journal of Animal Science and Biotechnology 2018年第2期9卷 306-318页

作者： Yasser Y.Lenis Gregory A.Johnson Xiaoqiu Wang Wendy W.Tang kathrin A.dunlap M.Carey Satterfield Guoyao Wu Thomas R.Hansen Fuller W.Bazer Department of Animal Science Texas A&M UniversityCollege StationTX 77843-2471USA Center for Animal Biotechnology and Genomics Texas A&M UniversityCollege StationTX 77843USA Centauro Research Group School of Veterinary MedicineFaculty of Agrarian ScienceUniversidad de AntioquiaCalle 70 No52-21 MedellínColombia Faculty of Agricultural Sciences Calle 222 No.55-37UDCABogotaColombia Present address:National Institute of Environmental Health Sciences Research Triangle ParkNC 27709USA Animal Reproduction and Biotechnology Laboratory Department of Biomedical SciencesCollege of Veterinary Medicine and Biomedical SciencesColorado State UniversityFort CollinsCO 80523USA

Background: Polyamines stimulate DNA transcription and m RNA translation for protein synthesis in trophectoderm cells, as well as proliferation and migration of cells; therefore, they are essential for development and survival of conceptuses(embryo/fetus and placenta). The ovine conceptus produces polyamines via classical and non-classical pathways. In the classical pathway, arginine(Arg) is transformed into ornithine, which is then decarboxylated by ornithine decarboxylase(ODC1) to produce putrescine which is the substrate for the production of spermidine and spermine. In the non-classical pathway, Arg is converted to agmatine(Agm) by arginine decarboxylase(ADC), and Agm is converted to putrescine by agmatinase(AGMAT).Methods: Morpholino antisense oligonucleotides(MAOs) were designed and synthesized to inhibit translational initiation of the m RNAs for ODC1 and ADC, in ovine ***: The morphologies of MAO control, MAO-ODC1, and MAO-ADC conceptuses were normal. Double knockdown of ODC1 and ADC(MAO-ODC1:ADC) resulted in two phenotypes of conceptuses; 33% of conceptuses appeared to be morphological y and functional y normal(phenotype a) and 67% of the conceptuses presented an abnormal morphology and functionality(phenotype b). Furthermore, MAO-ODC1:ADC(a) conceptuses had greater tissue concentrations of Agm,putrescine, and spermidine than MAO control conceptuses, while MAO-ODC1:ADC(b) conceptuses only had greater tissue concentrations of Agm. Uterine flushes from ewes with MAO-ODC1:ADC(a) had greater amounts of arginine, aspartate, tyrosine, citrulline, lysine, phenylalanine, isoleucine, leucine, and glutamine, while uterine flushes of ewes with MAO-ODC1:ADC(b) conceptuses had lower amount of putrescine, spermidine, spermine, alanine, aspartate,glutamine, tyrosine, phenylalanine, isoleucine, leucine, and ***: The double-knockdown of translation of ODC1 and ADC m RNAs was most detrimental to conceptus development and their production of int

关键词： Agmatine Arginine Interferon tau Polyamines Trophectoderm cells

Pre-implantation exogenous progesterone and pregnancy in sheep:***,nutrient transport,and progestamedins

在线全文

学校读者我要写书评

暂无评论

Journal of Animal Science and Biotechnology 2021年第3期12卷 935-951页

作者： Emily C.Hoskins Katherine M.Halloran Claire Stenhouse Robyn M.Moses kathrin A.dunlap Michael C.Satterfield Heewon Seo Gregory A.Johnson Guoyao Wu Fuller W.Bazer Departments of Animal Science Texas A&M UniversityCollege StationTX 77843-2471USA Veterinary Integrative Biosciences Texas A&M UniversityCollege StationTX 77843USA

Background:Administration of exogenous progesterone(P4)to ewes during the pre-implantation period advances conceptus development and *** study determined effects of exogenous P4 on transport of select nutrients and pathways that enhance conceptus *** ewes(n=38)were treated with either 25 mg P4 in 1 mL corn oil(P4,n=18)or 1mL corn oil alone(CO,n=20)from day 1.5 through day 8 of pregnancy and hysterectomized on either day 9 or day 12 of *** expression of genes encoding enzymes for synthesis of polyamines,transporters of glucose,arginine,and glycine,as well as progestamedins was determined by ***:On day 12 of pregnancy,conceptuses from P4-treated ewes had elongated while those from CO-treated ewes were *** mRNA expression of AZIN2,an arginine decarboxylase,was lower in endometria of P4-treated than CO-treated ewes on day 9 of *** of FGF10,a progestamedin,was greater in endometria of CO and P4-treated ewes on day 12 of gestation in addition to P4-treated ewes necropsied on day 9 of *** with P4 down-regulated endometrial expression of amino acid transporter SLC1A4 on day 12 of ***:Results indicated that administration of exogenous P4 during the pre-implantation period advanced the expression of FGF10,which may accelerate proliferation of trophectoderm cells,but also was correlated with decreased expression of glycine and serine transporters and polyamine synthesis enzyme *** research with increased sample sizes may determine how differential expression affects endometrial functions and potentially embryonic loss.

关键词： Amino acid Endometrium Gene expression Polyamine Progesterone

Pre-implantation exogenous progesterone and pregnancy in *** on fetalplacental development and nutrient transporters in late pregnancy

在线全文

学校读者我要写书评

暂无评论

Journal of Animal Science and Biotechnology 2021年第3期12卷 952-971页

作者： Katherine M.Halloran Emily C.Hoskins Claire Stenhouse Robyn M.Moses kathrin A.dunlap M.Carey Satterfield Heewon Seo Gregory A.Johnson Guoyao Wu Fuller W.Bazer Department of Animal Science Texas A&M UniversityCollege StationTX 77843-2471USA Department of Veterinary Integrative Biosciences Texas A&M UniversityCollege StationTX 77843USA

Background:Administration of progesterone(P4)to ewes during the first 9 to 12 days of pregnancy accelerates blastocyst development by day 12 of pregnancy,likely due to P4-induced up-regulation of key genes in uterine epithelia responsible for secretion and transport of components of histotroph into the uterine *** study determined if acceleration of blastocyst development induced by exogenous P4 during the pre-implantation period affects fetal-placental development on day 125 of *** ewes(n=35)were mated to fertile rams and assigned randomly to receive daily intramuscular injections of either corn oil vehicle(CO,n=18)or 25 mg progesterone in CO(P4,n=17)for the first 8 days of *** ewes were hysterectomized on day 125 of pregnancy and:1)fetal and placental weights and measurements were recorded;2)endometrial and placental tissues were analyzed for the expression of candidate mRNAs involved in nutrient transport and arginine metabolism;and 3)maternal plasma,fetal plasma,allantoic fluid,and amniotic fluid were analyzed for amino acids,agmatine,polyamines,glucose,and ***:Treatment of ewes with exogenous P4 did not alter fetal or placental growth,but increased amounts of aspartate and arginine in allantoic fluid and amniotic fluid,*** that received exogenous P4 had greater expression of mRNAs for SLC7A1,SLC7A2,SLC2A1,AGMAT,and ODC1 in endometria,as well as SLC1A4,SLC2A5,SLC2A8 and ODC1 in *** addition,AZIN2 protein was immunolocalized to uterine luminal and glandular epithelia in P4-treated ewes,whereas AZIN2 localized only to uterine luminal epithelia in CO-treated ***:This study revealed that exogenous P4 administered in early pregnancy influenced expression of selected genes for nutrient transporters and the expression of a protein involved in polyamine synthesis on day 125 of pregnancy,suggesting a‘programming’effect of P4 on gene expression that affected the composition of nutrients in f

关键词： Amino acids Endometrium Fructose Gene expression Glucose Placenta Polyamines Progesterone

FTY720,a sphingosine analog,altered placentome histoarchitecture in ewes

在线全文

学校读者我要写书评

暂无评论

Journal of Animal Science and Biotechnology 2020年第2期11卷 380-392页

作者： kathrin A.dunlap Bryan G.White David W.Erikson M.Carey Satterfield Christiane Pfarrer Guoyao Wu Fuller W.Bazer Robert C.Burghardt Kayla J.Bayless Greg A.Johnson Department of Animal Science Texas A&M UniversityCollege StationTX 77843USA Okanagan College Salmon Arm Campus Salmon ArmBritish ColumbiaCanada Endocrine Technologies Core Oregon National Primate Research CenterOregon Health&Science UniversityBeavertonORUSA Department of Anatomy University of Veterinary Medicine HannoverBischofsholer Damm 1530173 HannoverGermany Department of Veterinary Integrative Biosciences College of Veterinary Medicine and Biomedical SciencesTexas A&M UniversityCollege StationTX 77843USA Department of Molecular and Cellular Medicine Texas A&M Health Science CenterCollege StationTX 77843USA

Background:The lysosphingolipid,sphingosine-1-phosphate,is a well-described and potent pro-angiogenic ***,as well as the sphingosine phosphorylating enzyme sphingosine kinase 1,are expressed in the placentomes of sheep and the decidua of rodents;however,a function for this signaling pathway during pregnancy has not been *** objective of this study was to investigate whether sphingosine-1-phosphate promoted angiogenesis within the placentomes of pregnant *** were given daily jugular injections of FTY720(2-amino-2[2-(−4-octylphenyl)ethyl]propate-1,3-diol hydrochloride),an S1P ***:FTY720 infusion from days 30 to 60 of pregnancy did not alter maternal organ weights nor total number or mass of placentomes,but did alter placentome *** of caruncular crypts and cotyledonary villi was decreased,as was the relative area of cotyledonary tissue within ***,the percentage of area occupied by cotyledonary villi per unit of placentome was increased,while the thickness of the caruncular capsule was decreased in ewes treated with ***,FTY720 infusion decreased the number and density of blood vessels within caruncular tissue near the placentome capsule where the crypts emerge from the ***,FTY720 infusion decreased asparagine and glutamine in amniotic fluid and methionine in allantoic fluid,and decreased the crown rump length of day 60 ***:While members of the sphingosine-1-phosphate signaling pathway have been characterized within the uteri and placentae of sheep and mice,the present study uses FTY720 to address the influence of S1P signaling on placental *** present evidence that modulation of the S1P signaling pathway results in the alteration of caruncular vasculature,placentome architecture,abundance of amino acids in allantoic and amniotic fluids,and fetal growth during pregnancy in *** marked morphological changes in placentome histoarchitec

关键词： Placentome Pregnancy Sheep Sphingosine1 phosphate(S1P)