The renal glomerulus is composed of endothelial and mesangial cells with podocytes contributing to glomerular filtration. Podocyte damage is associated with renal disorders, thus there is interest in these cells for regenerative medicine. These studies investigated the use of extracellular matrix (ECM) to grow third trimester fetal monkey renal cortical cells and to assess mature podocytes in culture.
View Article and Find Full Text PDFTherapeutic angiogenesis is a promising strategy to promote the formation of new or collateral vessels for tissue regeneration and repair. Since changes in tissue oxygen concentrations are known to stimulate numerous cell functions, these studies have focused on the oxygen microenvironment and its role on the angiogenic potential of endothelial cells. We analyzed the proangiogenic potential of human endothelial colony-forming cells (hECFCs), a highly proliferative population of circulating endothelial progenitor cells, and compared outcomes to human dermal microvascular cells (HMVECs) under oxygen tensions ranging from 1% to 21% O2, representative of ischemic or healthy tissues and standard culture conditions.
View Article and Find Full Text PDFObjective: Murine embryonic stem cells can be differentiated into embryoid bodies (EBs), which serve as an in vitro model recapitulating many aspects of embryonic yolk sac hematopoiesis. Differentiation of embryonic stem cells deficient in either Gata-4 or Gata-6 results in EBs with disrupted visceral endoderm (VE). While lack of VE has detrimental effects on hematopoiesis in vivo, it is unclear whether lack of VE affects hematopoiesis in EBs.
View Article and Find Full Text PDFThe development of the metanephric kidney was studied immunohistochemically across gestation in monkeys to identify markers of cell specification, and to aid in developing experimental paradigms for renal precursor differentiation from human embryonic stem cells (hESC). PAX2, an important kidney developmental marker, was expressed at the tips of the ureteric bud, in the surrounding condensing mesenchyme, and in the renal vesicle. Vimentin, a mesenchymal and renal marker, was strongly expressed in the metanephric blastema then found to be limited to the glomerulus and interstitial cells of the medulla and cortex.
View Article and Find Full Text PDFBiomechanical forces are emerging as critical regulators of embryogenesis, particularly in the developing cardiovascular system. After initiation of the heartbeat in vertebrates, cells lining the ventral aspect of the dorsal aorta, the placental vessels, and the umbilical and vitelline arteries initiate expression of the transcription factor Runx1 (refs 3-5), a master regulator of haematopoiesis, and give rise to haematopoietic cells. It remains unknown whether the biomechanical forces imposed on the vascular wall at this developmental stage act as a determinant of haematopoietic potential.
View Article and Find Full Text PDFPurpose Of Review: We highlight some recent high-profile articles in which the study results and interpretations, upon comparison, convey the controversy and disparate views prevalent in the field when defining the role of murine bone marrow-derived endothelial progenitor cells in the process of tumor neoangiogenesis.
Recent Findings: Highlighted articles identify a critical role for these cells in promoting the angiogenic switch for growth of metastatic tumors or find no role at all for these circulating cells as engrafting cells in vascular endothelium or as promoters of tumor growth. We suggest potential strategies to further document cell identities as a guide for future studies and provide some alternative interpretations of the published studies highlighted in this review that, if considered, may diminish the current polar views.
Interest in the regulation of blood vessel formation as a mechanism to permit unregulated tumor cell growth was a prescient hypothesis of Dr. Judah Folkman nearly 3 decades ago. Understanding the cellular and molecular mechanisms that affect the recruitment, expansion, and turnover of the tumor microvasculature continues to evolve.
View Article and Find Full Text PDFAutism is a developmental disability increasing in incidence over the past decade. Parents of children with autism experience prolonged levels of stress and isolation. Using qualitative research design, nine parents of children with autism participated in this study that focused on the effect of autism on the family, coping styles, and support systems.
View Article and Find Full Text PDFSince their initial discovery more than a decade ago, bone marrow (BM)-derived circulating endothelial progenitor cells (EPC) have been reported to play a role in postnatal vasculogenesis through vessel regeneration and remodeling. These cells have been reported to mobilize into the blood stream in response to vascular injury, and differentiate into cells expressing a host of endothelial cell (EC) markers in vitro. Because of demonstrable regenerative capacity in animal models of human disease, EPC are thought to represent a novel treatment option for problematic cardiovascular conditions such as myocardial infarction (MI) and peripheral vascular disease (PVD).
View Article and Find Full Text PDFCould it be that fetal liver cells and adult bone-marrow cells originate from a subset of endothelial cells that line blood vessels in the mouse embryo? Several lines of evidence suggest that this might be the case.
View Article and Find Full Text PDFAm J Physiol Heart Circ Physiol
March 2009
While tissue perfusion and angiogenesis subsequent to acute femoral artery occlusion are suppressed in NADPH oxidase 2 (Nox2)-null (Nox2(-/-)) mice, studies have not established the role of Nox2 in collateral artery enlargement. Rac2 is a small GTPase that binds Nox2 and activates Nox2-based NAD(P)H oxidase but, unlike Nox2, is primarily restricted to bone marrow-derived cells. In this study, we used Rac2-null (Rac2(-/-)) and Nox2(-/-) mice with a novel method of identifying primary hindlimb collaterals to investigate the hypothesis that collateral growth requires these molecules.
View Article and Find Full Text PDFSenescence of endothelial cells increases with systemic aging and is thought to contribute to the development of atherosclerosis. Cell therapy with highly proliferative endothelial progenitor cells (EPCs) is an emerging therapeutic option to promote endothelial regeneration, but little is known about their senescence and their vulnerability to inflammatory stressors. We therefore studied the senescence of proliferative human EPCs and investigated the effects of the proinflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) on their senescence.
View Article and Find Full Text PDFHerein, we describe an obligate role for the hematopoietic specific GTPase, RAC2 in endothelial integrin signaling and the postnatal neovascularization response in vivo. Using a Rac2 knockout mouse model, we discovered that despite the presence of both RAC1 and RAC2 protein in endothelial cells, RAC2 is obligately required for the postnatal neovascular response and alphavbeta3/ alpha4beta1/alpha5beta1 integrin-directed migration on vitronectin, H296 and CH271, fibronectin fragments, respectively. The molecular basis for RAC2 specificity was explored.
View Article and Find Full Text PDFIn the past decade, researchers have gained important insights on the role of bone marrow (BM)-derived cells in adult neovascularization. A subset of BM-derived cells, called endothelial progenitor cells (EPCs), has been of particular interest, as these cells were suggested to home to sites of neovascularization and neoendothelialization and differentiate into endothelial cells (ECs) in situ, a process referred to as postnatal vasculogenesis. Therefore, EPCs were proposed as a potential regenerative tool for treating human vascular disease and a possible target to restrict vessel growth in tumour pathology.
View Article and Find Full Text PDFBone marrow derived endothelial progenitor cells (EPCs) are early precursors of mature endothelial cells which replenish aging and damaged endothelial cells. The authors studied a diabetic swine model to determine if induction of DM adversely affects either bone marrow or circulating EPCs and whether a HMG-CoA reductase inhibitor (statin) improves development and recruitment of EPCs in the absence of cholesterol lowering. Streptozotocin was administered to Yorkshire pigs to induce DM.
View Article and Find Full Text PDFThe murine embryo has become a valuable tool to examine the ontogeny of hematopoiesis. However, the onset of the systemic circulation has long been a confounding developmental variable that may mask the site of blood cell emergence. This Minireview examines some approaches that have been applied to overcome this obstacle.
View Article and Find Full Text PDFIn an effort to address the home care nursing shortage, this pilot study was designed to measure nursing students' attitudes toward home health nursing and to test the Home Health Attitude Questionnaire developed specifically for this study based on the Theory of Planned Behavior. Senior undergraduate nursing students and registered nursing to bachelor of science in nursing students completed the questionnaire.
View Article and Find Full Text PDFCurr Protoc Stem Cell Biol
July 2008
Circulating endothelial progenitor cells (EPCs) in adult human peripheral blood were originally identified in 1997 by Asahara et al., which challenged the paradigm that vasculogenesis is a process restricted to embryonic development. Since their original identification, EPCs have been extensively studied as biomarkers to assess the risk of cardiovascular disease in human subjects and as a potential cell therapeutic for vascular regeneration.
View Article and Find Full Text PDFArterioscler Thromb Vasc Biol
September 2008
Acta Crystallogr Sect F Struct Biol Cryst Commun
July 2008
Polygalacturonases are pectate-degrading enzymes that belong to glycoside hydrolase family 28 and hydrolyze the alpha-1,4 glycosidic bond between neighboring galacturonasyl residues of the homogalacturonan substrate. The acidic polygalacturonase PehA from Agrobacterium vitis was overexpressed in Escherichia coli, where it accumulated in the periplasmic fraction. It was purified to homogeneity via a two-step chromatography procedure and crystallized using the hanging-drop vapour-diffusion technique.
View Article and Find Full Text PDFMurine embryonic stem (mES) cells are pluripotent cells derived from the inner cell mass of the preimplantation blastocyst. These cells are primitive and undifferentiated and have the potential to become a wide variety of specialized cell types. Mouse ES cells can be regarded as a versatile biological tool that has led to major advances in our understanding of cell and developmental biology.
View Article and Find Full Text PDFIn an effort to discover specific markers to isolate human hematopoietic stem cells, Jokubaitis and colleagues report that the monoclonal antibody BB9 reacts with hematopoietic cells displaying morphologic, phenotypic, and/or functional properties of stem and progenitor cells throughout human ontogeny.
View Article and Find Full Text PDFTherapeutic levels of expression of the beta-globin gene have been difficult to achieve with conventional retroviral vectors without the inclusion of DNase I-hypersensitive site (HS2, HS3, and HS4) enhancer elements. We generated recombinant adeno-associated viral (AAV) vectors carrying an antisickling human beta-globin gene under the control of either the beta-globin gene promoter/enhancer or the erythroid cell-specific human parvovirus B19 promoter at map unit 6 (B19p6) without any enhancer, and tested their efficacy in a human erythroid cell line (K-562) and in primary murine hematopoietic progenitor cells (c-kit(+)lin()). We report here that (1) self-complementary AAV serotype 2 (scAAV2)-beta-globin vectors containing only the HS2 enhancer are more efficient than single-stranded AAV (ssAAV2)-beta-globin vectors containing the HS2+HS3+HS4 enhancers; (2) scAAV2-beta-globin vectors recombine with scAAV2-HS2+HS3+HS4 vectors after dual-vector transduction, leading to transgene expression; (3) scAAV2-beta-globin as well as scAAV1-beta-globin vectors containing the B19p6 promoter without the HS2 enhancer element are more efficient than their counterparts containing the HS2 enhancer/beta-globin promoter; and (4) scAAV2-B19p6-beta-globin vectors in K-562 cells, and scAAV1-B19p6-beta-globin vectors in murine c-kit(+)lin() cells, yield efficient expression of the beta-globin protein.
View Article and Find Full Text PDFMeasuring and describing client problems, nursing interventions, and outcomes is a challenge in nursing care. This study reviews the literature about the use of the Omaha System and describes the steps used to introduce and implement the Omaha System as a documentation and outcome measurement system in academic nurse-managed centers. The goal of the article is to provide a guide for nurse educators to develop and implement a quality measurement system that can be used in clinical settings by undergraduate students.
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