Spatiotemporal dynamics of cytokines expression dictate fetal liver hematopoiesis.

During embryogenesis, yolk-sac and intra-embryonic-derived hematopoietic progenitors, comprising the precursors of adult hematopoietic stem cells, converge into the fetal liver. With a new staining strategy, we defined all non-hematopoietic components of the fetal liver and found that hepatoblasts are the major producers of hematopoietic growth factors. We identified mesothelial cells, a novel component of the stromal compartment, producing Kit ligand, a major hematopoietic cytokine.

Assembling the layers of the hematopoietic system: A window of opportunity for thymopoiesis in the embryo.

During embryonic development, several independent generations of hematopoietic cells were identified. They occur in the yolk sac and the intra-embryonic major arteries, in a narrow window of development. They arise sequentially, starting with primitive erythrocytes in the yolk sac blood islands, progressing to less differentiated erythromyeloid progenitors still in the yolk sac, and culminating with multipotent progenitors, some of which will generate the adult hematopoietic stem cell compartment.

Identification of fetal liver stroma in spectral cytometry using the parameter autofluorescence.

The fetal liver (FL) is the main hematopoietic organ during embryonic development. The FL is also the unique anatomical site where hematopoietic stem cells expand before colonizing the bone marrow, where they ensure life-long blood cell production and become mostly resting. The identification of the different cell types that comprise the hematopoietic stroma in the FL is essential to understand the signals required for the expansion and differentiation of the hematopoietic stem cells.

Application of Optimal Control of Infectious Diseases in a Model-Free Scenario.

Optimal control for infectious diseases has received increasing attention over the past few decades. In general, a combination of cost state variables and control effort have been applied as cost indices. Many important results have been reported.

Hematopoiesis: A Layered Organization Across Chordate Species.

The identification of distinct waves of progenitors during development, each corresponding to a specific time, space, and function, provided the basis for the concept of a "layered" organization in development. The concept of a layered hematopoiesis was established by classical embryology studies in birds and amphibians. Recent progress in generating reliable lineage tracing models together with transcriptional and proteomic analyses in single cells revealed that, also in mammals, the hematopoietic system evolves in successive waves of progenitors with distinct properties and fate.

Crosstalk Between the Hepatic and Hematopoietic Systems During Embryonic Development.

Hematopoietic stem cells (HSCs) generated during embryonic development are able to maintain hematopoiesis for the lifetime, producing all mature blood lineages. HSC transplantation is a widely used cell therapy intervention in the treatment of hematologic, autoimmune and genetic disorders. Its use, however, is hampered by the inability to expand HSCs , urging for a better understanding of the mechanisms regulating their physiological expansion.

CPAP increases 6-minute walk distance after lung resection surgery.

Background: The application of CPAP has been used to minimize postoperative pulmonary complications after lung resection surgery. The aim of this study was to quantify both the CPAP effects upon lung function and functional capacity in early postoperative lung resection, as well as to evaluate if CPAP prolongs air leak through the chest drain.

Methods: Thirty patients in the postoperative period of lung resection were allocated into 2 groups: an experimental group, consisting of 15 patients who underwent a 10 cm H(2)O CPAP, and a 15 patient control group, who performed breathing exercises.