The Bone Marrow Endosteal Niche: How Far from the Surface?

aaHematopoietic stem cells (HSC) self‐renewal takes place in the same microenvironment in which massive hematopoietic progenitor proliferation, commitment, and differentiation will occur. This is only made possible if the bone marrow microenvironment comprises different specific niches, composed by different stromal cells that work in harmony to regulate all the steps of the hematopoiesis cascade. Histological and functional assays indicated that HSC and multipotent progenitors preferentially colonize the endosteal and subendosteal regions, in close association with the bone surface. Conversely, committed progenitors and differentiated cells are distributed in the central and perisinusoidal regions, respectively. Over the last decade, many investigative teams sought to define which cell types regulate the HSC niche, how they are organized, and to what extent they interface with each other. System dynamics requires different stromal cells to operate distinct functions over similar HSC pools rather than a single stromal cell type controlling everything. Therefore, our focus herein is to depict the players in the endosteal and subendosteal regions, named the endosteal niche, a necessary step to better understand the interactions of the HSC within the niche and to identify potential targets to manipulate and/or modulate normal and malignant HSC behavior. J. Cell. Biochem. 116: 6–11, 2015. © 2014 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109640/1/jcb24952.pd

De‐epithelialized connective tissue graft and the reminiscent epithelial content after harvested by the Harris’ technique: a histological and morphometrical case series

Introduction: The remaining epithelial layer existent in connective tissue graft (CTG) harvested from the hard palate, which underwent de‐epithelization outside the oral cavity, can be histologically detected unless it is completely removed. Its presence may cause adverse esthetics results, affecting thus the color and texture of the receptor site, and an increased risk of presence of scar tissues after surgical procedures. The proposal of this study was to evaluate the CTG (histological and morphometrically) collected from the hard palate using the Harris’ technique, removing the epithelial layer outside the mouth, assessing the remaining presence of epithelial tissue. Case Series: Fourteen patients (14CTGs) were included in the present case series study, therefore there was two dropouts. A small part of the tip of the graft was harvested and fixed in formalin solution for histological processing, staining, and then to be morphometrically analyzed. The epithelial tissue and CTGs were assessed by three calibrated and double‐blinded professionals. All information was compiled and performed the statistical analysis. CTGs obtained had a width average of 1224.26μm. There was no presence of any residual of the epithelium in three samples, whereas only one had the epithelium tissue covering the entire connective layer. Furthermore, seven samples (approximately 50%) had the presence of epithelium. Conclusion: Within the limitation of this study, there was incomplete removal of the epithelial layer after harvesting the CTG using the Harris’ technique (44.32%), most likely due to its histological persistency, suggesting to be inaccurate the clinical removal.info:eu-repo/semantics/acceptedVersio

CARACTERIZAÇÃO MORFOLÓGICA, FREQUÊNCIA DE COLHEITA E ENSILAGEM DE PALMA FORRAGEIRA: UMA REVISÃO

Objetivou-se obter informações atuais sobre morfologia, frequência de colheita e ensilagem de palma forrageira. O crescimento e o desenvolvimento satisfatório na palma forrageira, dependem da combinação adequada do manejo cultural, dos fatores ambientais e do potencial genético da variedade. A colheita é realizada com 1,5 a 2 anos ou mais, e dependendo do desenvolvimento da cultura de acordo as condições do solo e clima, possivelmente poderá ser feito o corte anual. Recursos de utilização de irrigação em pequenas quantidades e frequência pode aumentar a frequência de corte. Existem muitas variações nas características morfologias, e quando é priorizado acréscimo na produção de matéria seca em toneladas por hectare a cada dois anos, deve-se priorizar a seleção de clones de maior altura e largura da planta. Por apresentar cladódios ricos em carboidratos solúveis e água, antioxidantes, fibras dietéticas, vitaminas e apresentar massas viscosas na água devido a mucilagem, a palma forrageira pode ser ensilada. A frequência de colheita depende da necessidade dos produtores. A colheita influência nas características morfológicas. A palma pode ser ensilada em diferente frequência de corte, no entanto

The potential therapeutic use of cord blood in autologous transplants or in special patients: a review and update

Umbilical Cord Blood is a rich source of hematopoietic stem cells widely used as a substitute of bone marrow (BM) in transplants. Cells from umbilical cord blood present advantages over BM cells, mainly as they are younger and a have higher proliferative rate. Besides hematopoietic stem cells, umbilical cord blood contains endothelial and mesenchymal progenitor cells, suggesting their possible application in cell therapy protocols for different tissues. In this paper, we discuss the importance of autologous umbilical cord blood storage and the research on stem cell transplantation for degenerative diseases.O sangue de cordão umbilical e placentário (SCUP) é uma rica fonte de células-tronco (CT) hematopoéticas e é amplamente utilizado como substituto da medula óssea em casos de transplante. As células do SCUP possuem vantagens sobre as células da medula óssea (MO), principalmente por serem mais jovens e apresentarem maior taxa proliferativa. Além dos progenitores hematopoéticos, o sangue de cordão umbilical contém progenitores endoteliais e mesenquimais, sugerindo sua possível aplicação nos novos protocolos de terapia celular para diferentes tecidos. Na presente revisão, discutimos a importância do armazenamento do sangue de cordão umbilical autólogo e as pesquisas desenvolvidas para a sua aplicação em doenças degenerativas.Cryopraxis Criobiologia LtdaUniversidade Federal de São Paulo (UNIFESP), Escola Paulista de Medicina (EPM)Instituto de Traumato-ortopediaSanta Casa de São PauloHospital Samaritano de São PauloUFRJ HUCFFHospital Central do ExércitoUFRJ IPPMGUFRJCollege of Medicine Department of Neurosurgery Center of Excellence for Aging & Brain RepairUNIFESP, EPMSciEL

High-Dose vs. Low-Dose Dexamethasone in Patients With COVID-19: A Cohort Study in Rural Central America

To compare the clinical outcomes of a low dose dexamethasone strategy vs. a high-dose dexamethasone strategy in hypoxemic COVID-19 patients. A retrospective observational study comparing low-dose (8 mg) and high-dose dexamethasone (24 mg) of COVID-19 patients admitted from September 1, 2020 to October 31, 2020 in a hospital in Honduras. We included 81 patients with confirmed COVID-19 who required oxygen therapy. The mean age was similar between groups (57.49 vs. 56.95 years). There were more male patients in the group of 24 mg (p = 0.01). Besides, patients on the 24 mg dose had more prevalence of hypertension (p = 0.052). More patients in the 24 mg group had a higher rate of invasive mechanical ventilation (15.00% vs. 2.56%, p = 0.058). When evaluating the association between the high dose group and outcomes, we find no significant association with mortality, nosocomial infections, high flow mask, invasive mechanical ventilation, or the need for vasopressors. We find no significant differences in the Kaplan–Meier analysis regarding the survival (log-rank p-value = 0.315). We did not find significant differences between the use of 24 mg and 8 mg of dexamethasone in hypoxemic COVID-19 patients.Revisión por pare

Senemorphism: a novel perspective on aging patterns and its implication for diet-related biology

Aging can be described as the accumulation of changes in organisms over time. Aging in organisms undergoing caloric restriction (CR) is widely considered as a slowed version of aging under ad libitum (AL) conditions. However, here we argue that aging under optimized CR is fundamentally different from aging under AL based on the following facts: (1) Comparing the two dietary groups, several age-related changes run in the opposite direction over time; (2) Switching from an AL to a CR diet clearly reverts (not only delays) several "normal" accumulated changes; (3) major causes of death are as different between both groups as they are between species. These observations support the idea that CR and AL initially modulate different metabolic and physiological programs, which exclusively over time generate two biologically different organisms. Such distinct diet-related senescence is analogous to the divergent aging processes and causes of death observed between castes of social insects, such as queens versus workers ("caste-related-senescence") and also between breeding versus non-breeding semelparous animals ("reproduction-related-senescence"). All these aging phenotypes are different not because they accumulate changes at a different rate, but because they accumulate different changes over time. Thus, the environment does not simply affect the individual aging rate through stochastic effects (e.g. U.V.) but also modulates the activation of a particular program/strategy that influences lifespan (e.g. caste, calorie intake). We refer to the environment-dependent aging patterns encoded by the genome as "senemorphism". Based on this idea we propose experimental schemes for aging, evolution and biomedical research

Caracterização morfológica, frequência de colheita e ensilagem de palma forrageira: Uma revisão

Objetivou-se obter informações atuais sobre morfologia, frequência de colheita e ensilagem de palma forrageira. O crescimento e o desenvolvimento satisfatório na palma forrageira, dependem da combinação adequada do manejo cultural, dos fatores ambientais e do potencial genético da variedade. A colheita é realizada com 1,5 a 2 anos ou mais, e dependendo do desenvolvimento da cultura de acordo as condições do solo e clima, possivelmente poderá ser feito o corte anual. Recursos de utilização de irrigação em pequenas quantidades e frequência pode aumentar a frequência de corte. Existem muitas variações nas características morfologias, e quando é priorizado acréscimo na produção de matéria seca em toneladas por hectare a cada dois anos, deve-se priorizar a seleção de clones de maior altura e largura da planta. Por apresentar cladódios ricos em carboidratos solúveis e água, antioxidantes, fibras dietéticas, vitaminas e apresentar massas viscosas na água devido a mucilagem, a palma forrageira pode ser ensilada. A frequência de colheita depende da necessidade dos produtores. A colheita influência nas características morfológicas. A palma pode ser ensilada em diferente frequência de corte, no entanto

Connexin expression and gap-junction-mediated cell interactions in an in vitro model of haemopoietic stroma

12 p. : il.In addition to the steady-state production of all blood cells, bone marrow can respond to an increased requirement for one or several cell lineages. The hormonal controls involved may act directly on blood cell progenitors or indirectly through modification of the haemopoietic environment. Intercellular gap junctions formed by connexins (Cx) provide direct communication among adjacent cells and the functional integration of multicellular systems. Since haemopoietic stroma is determinant for blood cell production, we have questioned whether gap-junction-dependent controls of haemopoiesis are sensitive to hormones and vitamins. We have analysed the expression, synthesis, cell distribution and formation of functional gap junctions in the murine bone-marrow stroma cell line S-17, and between stromal cells and blood cell progenitors. Nine Cxs were identified by reverse transcription/polymerase chain reaction, and only Cx43 by Western blot and immunofluorescence. All of the studied parameters were sensitive to intrinsic controls dependent upon the pattern of cell growth and modulated by exogenous controls mediated by retinol and steroids. Positive or negative modulation was specific for different Cxs. FACS analysis showed communication among the stromal cells and between stromal cells and myeloid (Mac1+) but not lymphoid (B220+) progenitors. Calcein transfer modulation did not correspond to the modulation of Cx43 expression and formation of connexons, suggesting the participation of other Cxs. Thus, functional gap junctions among haemopoietic stroma cells and between stroma and haematopoietic cells in the bone marrow may be modulated in response to hormonal stimuli, potentially controlling overall blood cell production