scholarly journals The role of stem cells in uterine involution

Reproduction ◽  
2021 ◽  
Vol 161 (3) ◽  
pp. R61-R77
Author(s):  
Madelyn K Spooner ◽  
Yasser Y Lenis ◽  
Rachel Watson ◽  
Daniela Jaimes ◽  
Amanda L Patterson
Keyword(s):  
Stem Cells ◽  
Stromal Cell ◽  
Embryo Implantation ◽  
Future Research ◽  
General Process ◽  
Additional Information ◽  
Uterine Involution ◽  
Primary Focus ◽  
Definition Of

Uterine remodeling during pregnancy and repair postpartum are fundamental to the successful propagation of eutherian species. The most drastic remodeling occurs in species with invasively implanting embryos, including humans and mice. During embryo implantation, embryonic trophoblasts breach the epithelium, penetrating into the stroma. Stromal cell decidualization, which is critical for the establishment and maintenance of early pregnancy, occurs throughout the implantation site. Trophoblasts further invade into and remodel uterine spiral arteries, which is necessary for placental formation. The uterus increases in size up to 24-fold, which is largely attributed to myometrial expansion. Uterine changes that occur during pregnancy must then be resolved postpartum. Following parturition, the uterus repairs the remodeled tissue in the process of uterine involution. During involution, the majority of the endometrium is regenerated to replace the tissue that is shed postpartum. The myometrium returns to the pre-gravid state which is thought to occur through apoptosis and autophagy of smooth muscle cells. Although we understand the general process of postpartum uterine involution, the detailed mechanisms, particularly the role of putative stem cells, are poorly understood. This review discusses the evidence for the existence of epithelial, stromal and myometrial stem cells and their role in uterine involution. Gaps in knowledge and areas for future research are also considered. Studies of both postpartum and menstrual uterine repair, which likely involve similar mechanisms, are described under the broad definition of uterine involution. Although the primary focus of this review is human, mouse models are discussed to provide additional information.

scholarly journals A Critical Review of Computational Creativity in Built Environment Design

Buildings ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 29
Author(s):  
Ning Gu ◽  
Peiman Amini Behbahani
Keyword(s):  
Built Environment ◽  
Critical Review ◽  
Contemporary Literature ◽  
Research Interest ◽  
Future Research ◽  
Computational Creativity ◽  
Environment Design ◽  
Supporting Tool ◽  
Definition Of

Computational creativity in built environment (BE) design has been a subject of research interest in the discipline. This paper presents a critical review of various ways computational creativity has been and can be defined and approached in BE design. The paper examines a comprehensive body of contemporary literature on the topics of creativity, computational creativity, and their assessment to identify levels of computational creativity. The paper then proceeds to a further review of the implications of these levels specifically in BE design. The paper identifies four areas in BE design where computational creativity is relevant. In two areas—synthesis (generation) and analysis—there is considerable literature on lower levels of computational creativity. However, in two other areas—interfacing and communication—even the definition of computational creativity is not as defined and clear for the discipline, and most works only consider the role of computers as a supporting tool or medium. These open up future research opportunities for the discipline.

scholarly journals The Role of the Bone Marrow Microenvironment in the Response to Infection

2020 ◽  
Vol 11 ◽  
Author(s):  
Courtney B. Johnson ◽  
Jizhou Zhang ◽  
Daniel Lucas
Keyword(s):  
Stem Cells ◽  
Bone Marrow ◽  
Immune Cells ◽  
Critical Role ◽  
Primary Source ◽  
Bone Marrow Microenvironment ◽  
Future Research ◽  
Multipotent Stem Cells ◽  
Hematopoietic Stem

Hematopoiesis in the bone marrow (BM) is the primary source of immune cells. Hematopoiesis is regulated by a diverse cellular microenvironment that supports stepwise differentiation of multipotent stem cells and progenitors into mature blood cells. Blood cell production is not static and the bone marrow has evolved to sense and respond to infection by rapidly generating immune cells that are quickly released into the circulation to replenish those that are consumed in the periphery. Unfortunately, infection also has deleterious effects injuring hematopoietic stem cells (HSC), inefficient hematopoiesis, and remodeling and destruction of the microenvironment. Despite its central role in immunity, the role of the microenvironment in the response to infection has not been systematically investigated. Here we summarize the key experimental evidence demonstrating a critical role of the bone marrow microenvironment in orchestrating the bone marrow response to infection and discuss areas of future research.

A Social Sonic Paradigm

2021 ◽  
pp. 540-554
Author(s):  
Tegan Bristow ◽  
João Orecchia Zúñiga
Keyword(s):  
Case Studies ◽  
Southern Africa ◽  
Political Engagement ◽  
Sound Art ◽  
Intellectual Engagement ◽  
The Third ◽  
Primary Focus ◽  
Definition Of ◽  
Forms Of Knowledge

This chapter presents an examination of why—in contemporary Africa, with Southern Africa as the primary focus—there are very few artists working with sound in a manner that fits the paradigm of sound art as it is known in Euro-America. Emphasis is not placed on a lack of intellectual engagement, which is significant in the Euro-American definition of sound art. What is presented does not aim to deviate from this, but rather acts to affirm an engagement with alternative forms of knowledge and mechanisms of sound found in the South. Three areas are explored; these however are interlinked and do not stand alone. The first is an understanding of the practice of interdisciplinarity as political engagement. The second explores the role of community and communal interaction with sound and how this is fundamental to form in the region. The third extends this by showing how the histories of knowledge and power are fundamental to these explorations in the region, emphasizing how contemporary explorations of sound are used to both contain and shift these histories. The chapter takes shape with the use of case studies and draws on interviews conducted by the authors.

scholarly journals CXCR4-SDF-1 Signaling in Nestin+ Mesenchymal Stem Cell Is Required for HSC Maintenance during Homeostasis and Regeneration after Irradiation

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 3883-3883 ◽  
Author(s):  
Pratibha Singh ◽  
Louis M. Pelus
Keyword(s):  
Stem Cells ◽  
Stromal Cell ◽  
Cxcr4 Expression ◽  
Wild Type ◽  
Post Transplantation ◽  
Hematopoietic Stem ◽  
Cxcr4 Signaling ◽  
Hematopoietic Recovery ◽  
Hematopoietic Reconstitution

Hematopoietic stem cells (HSC) reside in a complex microenvironment (niche) within the bone marrow (BM), where multiple populations of microenvironmental stromal cells regulate and finely tune their proliferation, differentiation and trafficking. Recent studies have shown that mesenchymal stem cells (MSC) are an essential component of the HSC niche. Intrinsic HSC CXCR4-SDF-1 signaling has been implicated in self-renewal and quiescence; however, the role of microenvironment CXCR4-SDF-1 signaling in supporting HSC function remains unclear. We previously demonstrated that microenvironmental stromal cell-derived CXCR4 is important for HSC recovery, as transplantation of wild-type HSC into CXCR4 deficient recipients showed reduced HSC engraftment. In this study, we now show that CXCR4-SDF-1 signaling in nestin+ MSC regulates HSC maintenance under normal homeostatic conditions and promotes hematopoietic regeneration after irradiation. Multivariate flow cytometry analysis of marrow stroma cells revealed that mouse BM MSCs identified as CD45-Ter119-CD31-Nestin+PDGFR+CD51+ express the CXCR4 receptor, which was confirmed by RT-PCR analysis. To investigate the role of MSC CXCR4 signaling in niche maintenance and support of HSC function, we utilized genetic mouse models, in which CXCR4 could be deleted in specific stromal cell types. Selective deletion of CXCR4 from nestin+ MSC in adult tamoxifen inducible nestin-cre CXCR4flox/flox mice resulted in reduced total MSC in BM (Control vs. Deleted: 647±128 vs. 209±51/femur, respectively, n=5, p<0.05), which was associated with a significant reduction in Lineage-Sca-1+c-Kit+ (LSK) cells (Control vs. Deleted: 18,033±439 vs. 4523±358/femur, respectively n=5, p<0.05). Selective CXCR4 deletion in nestin+ MSC also resulted in enhanced LSK cell egress to the peripheral circulation (Control vs. Deleted: 1022±106 vs. 2690±757/ml blood, respectively n=5, p<0.05), with no detectable difference in HSC cell cycle or apoptosis. However, the repopulation ability of HSC obtained from mice where CXCR4 was deleted in nestin+ MSC was reduced by >2 fold. In contrast, deletion of CXCR4 from osteoblasts using osteocalcin cre CXCR4flox/flox mice had no effect on HSC numbers in BM and blood.To investigate the role of nestin+ MSC CXCR4 signaling in BM niche reconstruction and hematopoietic recovery, we transplanted BM cells from wild-type mice into syngeneic wild-type or nestin+ MSC CXCR4 deleted recipients after lethal irradiation (950 rad) and analyzed HSC homing, niche recovery and hematopoietic reconstitution. Deletion of CXCR4 from nestin expressing MSC resulted in significantly reduced LSK cell homing at 16 hrs post transplantation (Control vs. Deleted: 8643±1371 vs. 3004±1044/ mouse, respectively, n=5, p<0.05). Robust apoptosis and senescence after total body irradiation was observed in nestin expressing MSCs lacking CXCR4 expression. At 15 days post-transplantation, chimeric mice with nestin+ MSC lacking CXCR4 expression displayed attenuated niche recovery and hematopoietic reconstitution compared to mice with wild-type stroma. In conclusion, our study suggests that CXCR4-SDF-1 signaling in nestin+ MSC is critical for the maintenance and retention of HSC in BM during homeostasis and promotes niche regeneration and hematopoietic recovery after transplantation. Furthermore, our data suggest the modulating CXCR4 signaling in the hematopoietic niche could be beneficial as a means to enhance HSC recovery following clinical hematopoietic transplantation or radiation/chemotherapy injury. Disclosures No relevant conflicts of interest to declare.

Diminished Parties

2021 ◽  
Keyword(s):  
Political Parties ◽  
Comparative Politics ◽  
Political Representation ◽  
Party Systems ◽  
Analytical Tool ◽  
Future Research ◽  
Developing Democracies ◽  
Party Organizations ◽  
Definition Of

Many contemporary party organizations are failing to fulfill their representational role in contemporary democracies. While political scientists tend to rely on a minimalist definition of political parties (groups of candidates that compete in elections), this volume argues that this misses how parties can differ not only in degree but also in kind. With a new typology of political parties, the authors provide a new analytical tool to address the role of political parties in democratic functioning and political representation. The empirical chapters apply the conceptual framework to analyze seventeen parties across Latin America. The authors are established scholars expert in comparative politics and in the cases included in the volume. The book sets an agenda for future research on parties and representation, and it will appeal to those concerned with the challenges of consolidating stable and programmatic party systems in developing democracies.

Cultivating Learning Agility Through Mindfulness

2021 ◽  
pp. 182-203
Author(s):  
R. Andrew Lee
Keyword(s):  
Process Model ◽  
Mindfulness Training ◽  
Future Research ◽  
Present Moment ◽  
Learning Agility ◽  
Five Factors ◽  
Definition Of

“Cultivating Learning Agility Through Mindfulness Training: A Framework and Recommendations” reviews the research related to the role of mindfulness in enhancing learning agility and presents a model to guide future research and applications. It begins by presenting a definition of mindfulness as characterized by three qualities: a focus on present moment experience, an attitude of receptiveness and curiosity, and an emergent capacity for metacognition. It then outlines a process model for learning agility; the model consists of five factors: mindset, awareness, action, integration, and application. This model is then used as a framework to summarize the research linking mindfulness and learning agility. Finally, recommendations are presented for implementing mindfulness training to enhance learning agility.

On the Road to Ephesus

2015 ◽  
pp. 102-125
Author(s):  
Suzanne Roff-Wexler
Keyword(s):  
Big Data ◽  
Future Research ◽  
Review Of Literature ◽  
Healthcare Organizations ◽  
Research Directions ◽  
The Road ◽  
Future Research Directions ◽  
On The Road ◽  
Definition Of

Following a brief review of literature on big data as well as wisdom, this chapter provides a definition of data-based wisdom in the context of healthcare organizations and their visions. The author addresses barriers and ways to overcome barriers to data-based wisdom. Insights from interviews with leading healthcare professionals add practical meaning to the discussion. Finally, future research directions and questions are suggested, including the role of synchronicity and serendipity in data-based wisdom. In this chapter, developing data-based wisdom systems that flourish Wisdom, Virtue, Intellect, and Knowledge are encouraged.

scholarly journals Clinical and Microbiological Determinants of Outcome inStaphylococcus aureusBacteraemia

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
James Price ◽  
Gillian Baker ◽  
Ian Heath ◽  
Karen Walker-Bone ◽  
Marc Cubbon ◽  
...  
Keyword(s):  
Methicillin Resistance ◽  
Central Line ◽  
Symptom Duration ◽  
Genetic Lineage ◽  
Metastatic Infection ◽  
Primary Focus ◽  
Definition Of ◽  
Community Onset ◽  
Microbiological Data

Staphylococcus aureusbacteraemia (SAB) is commonly complicated by metastatic infection or relapse after treatment.Objectives. The study aim was to determine the role of bacterial, host, and management factors in development of complicated SAB.Methods. A prospectively-conducted observational study gathered data on predisposition, management and outcome of 100 consecutive SAB cases. Antibiotic susceptibilities and genetic lineage of bacterial isolates were determined. Further clinical and microbiological data were gathered on two retrospective series from 1999–2000 (n=57) and 2004 (n=116).Results. In the prospective cases, 27% met our definition of complicated disease. Expressed as RR and 95% CI, complicated disease was associated with diabetes (1.58, 1.00–2.48), injecting-drug use (5.48, 0.88–33.49), community-onset of symptoms (1.4, 1.02–1.92), and symptom duration≥48hours prior to starting effective antibiotic therapy (2.10, 1.22–3.61). Uncomplicated disease was associated with the presence of a central line (0.69, 0.55–0.88) and prompt removal of a primary focus (0.71, 0.57–0.90). Neither methicillin resistance nor genetic lineage was associated with complicated disease, but methicillin resistance was associated with higher mortality.Conclusions. This study demonstrates that clinical rather than microbial factors are the major determinants of SAB outcome and underscores the importance of early treatment.

scholarly journals Effects of Global Climate on Infectious Disease: the Cholera Model

2002 ◽  
Vol 15 (4) ◽  
pp. 757-770 ◽  
Author(s):  
Erin K. Lipp ◽  
Anwar Huq ◽  
Rita R. Colwell
Keyword(s):  
Infectious Disease ◽  
Population Dynamics ◽  
Climate Variability ◽  
Global Climate ◽  
Historical Context ◽  
Disease Outbreaks ◽  
Critical Parameters ◽  
Future Research ◽  
Definition Of

SUMMARY Recently, the role of the environment and climate in disease dynamics has become a subject of increasing interest to microbiologists, clinicians, epidemiologists, and ecologists. Much of the interest has been stimulated by the growing problems of antibiotic resistance among pathogens, emergence and/or reemergence of infectious diseases worldwide, the potential of bioterrorism, and the debate concerning climate change. Cholera, caused by Vibrio cholerae, lends itself to analyses of the role of climate in infectious disease, coupled to population dynamics of pathogenic microorganisms, for several reasons. First, the disease has a historical context linking it to specific seasons and biogeographical zones. In addition, the population dynamics of V. cholerae in the environment are strongly controlled by environmental factors, such as water temperature, salinity, and the presence of copepods, which are, in turn, controlled by larger-scale climate variability. In this review, the association between plankton and V. cholerae that has been documented over the last 20 years is discussed in support of the hypothesis that cholera shares properties of a vector-borne disease. In addition, a model for environmental transmission of cholera to humans in the context of climate variability is presented. The cholera model provides a template for future research on climate-sensitive diseases, allowing definition of critical parameters and offering a means of developing more sophisticated methods for prediction of disease outbreaks.

scholarly journals Role of the Hedgehog Signaling Pathway in Regulating the Behavior of Germline Stem Cells

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Shiqin Li ◽  
Meng Wang ◽  
Yanghui Chen ◽  
Wei Wang ◽  
Junying Wu ◽  
...  
Keyword(s):  
Stem Cells ◽  
Signaling Pathway ◽  
Hedgehog Signaling ◽  
Adult Stem Cells ◽  
Reproductive Function ◽  
Future Research ◽  
Germline Stem Cells ◽  
Proliferation And Differentiation ◽  
Hh Signaling

Germline stem cells (GSCs) are adult stem cells that are responsible for the production of gametes and include spermatogonial stem cells (SSCs) and ovarian germline stem cells (OGSCs). GSCs are located in a specialized microenvironment in the gonads called the niche. Many recent studies have demonstrated that multiple signals in the niche jointly regulate the proliferation and differentiation of GSCs, which is of significance for reproductive function. Previous studies have demonstrated that the hedgehog (Hh) signaling pathway participates in the proliferation and differentiation of various stem cells, including GSCs in Drosophila and male mammals. Furthermore, the discovery of mammalian OGSCs challenged the traditional opinion that the number of primary follicles is fixed in postnatal mammals, which is of significance for the reproductive ability of female mammals and the treatment of diseases related to germ cells. Meanwhile, it still remains to be determined whether the Hh signaling pathway participates in the regulation of the behavior of OGSCs. Herein, we review the current research on the role of the Hh signaling pathway in mediating the behavior of GSCs. In addition, some suggestions for future research are proposed.

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