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INTRODUCTION: The human bone marrow microenvironment is composed of biological, chemical and physical factors that act in a synergistic way to modulate hematopoietic stem cell biology, such as mesenchymal stromal cells (MSCs), endothelial cells (ECs) and low oxygen levels; however, it is difficult to mimic this human microenvironment in vitro. METHODS: In this work, we developed 3D multicellular spheroid (3D-MS) for the study of human hematopoietic stem cells (HSCs) with some components of perivascular niche. HSCs were isolated from umbilical cord blood, MSCs were isolated from human bone marrow and a microvasculature EC line (CC-2811, Lonza®) was used. For the formation of a 3D structure, a magnetic levitation culture system was used. Cultures were maintained in 21%, 3% and 1% O2 for 15 days. Culture volume, sphericity index and cell viability were determined. Also, human HSC proliferation, phenotype and production of reactive oxygen species were evaluated. RESULTS: After 15 days, 3D-MS exhibited viability greater than 80%. Histology results showed structures without necrotic centers, and higher cellular proliferation with 3% O2. An increase in the expression of the CD34 antigen and other hematopoietic antigens were observed to 1% O2 with MSCs plus ECs and low ROS levels. CONCLUSION: These findings suggest that 3D-MS formed by MSCs, ECs and HSCs exposed to low concentrations of oxygen (1-3% O2) modulate human HSC behavior and mimics some features of the perivascular niche, which could reduce the use of animal models and deepen the relationship between the microenvironment of HSC and human hematological diseases development.
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BACKGROUND AND OBJECTIVE: The characteristics of human hematopoietic stem cells are conditioned by the microenvironment of the bone marrow, where they interact with other cell populations, such as mesenchymal stem cells and endothelial cells; however, the study of this microenvironment is complex. The objective of this work was to develop a 3D culture system by magnetic levitation that imitates the microenvironment of human HSC. METHODS AND RESULTS: Human bone marrow-mesenchymal stem cells, umbilical cord blood-hematopoietic stem cells and a non-tumoral endothelial cell line (CC2811, Lonzaâ) were used to develop organotypic multicellular spheres by the magnetic levitation method. We obtained viable structures with an average sphericity index greater than 0.6, an average volume of 0.5 mm3 and a percentage of aggregation greater than 70%. Histological studies of the organotypic multicellular spheres used hematoxylin and eosin stains, and an evaluation of vimentin expression by means of immunohistochemistry demonstrated an organized internal structure without picnotic cells and a high expression of vimentin. The functional capacity of human hematopoietic stem cells after organotypic multicellular spheres culture was evaluated by multipotency tests, and it was demonstrated that 3D structures without exogenous Flt3L are autonomous in the maintenance of multipotency of human hematopoietic stem cells. CONCLUSIONS: We developed organotypic multicellular spheres from normal human cells that mimic the microenvironment of the human hematopoietic stem cells. These structures are the prototype for the development of complex organoids that allow the further study of the biology of normal human stem cells and their potential in regenerative medicine.
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El síndrome antifosfolípido es una entidad que puede ocurrir de forma aislada o asociada a otras enfermedades. Una forma infrecuente es la manifestación con compromiso de las glándulas suprarrenales. Existen pocos casos en la literatura científica que describan este fenómeno. En el presente artículo, se presentan dos casos con comportamientos poco usuales...
Antiphospholipid syndrome is a disease that can manifest alone or associated with other conditions. Adrenal glands involvement is a rare presentation. There are few cases reported in the literature. We present two cases of patients with antiphospholipid syndrome thatcompromise the adrenal glands and behave very odd comparing to previous case reports...
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Enfermedad de Addison , Necrosis , Síndrome AntifosfolípidoRESUMEN
El adenocarcinoma fetal bien diferenciado de pulmón es un tumor raro compuesto por glándulas neoplásicas ricas en glucógeno y túbulos que se parecen al pulmón fetal entre la semana 10 y 16 de gestación[1]. Se presenta el caso de una mujer de 26 años, con antecedentes de bronquitis aguda y tabaquismo, cuyos hallazgos clínicos, imaginológicos, macroscópicos y microscópicos fueron indicativos de esta neoplasia. Se le practicó lobectomía inferior izquierda.
Well differentiated fetal adenocarcinoma is a rare lung tumour that is composed of glycogenrich neoplasic glands and tubules that resemble fetal lung at 10 to 16 weeks of gestation. In this report, we present a case of a 26 year old woman with a history of acute bronchitis and smoking, on which the clinical, imaging, macroscopic and microscopic features were compatible with this neoplasm. Lobectomy was performed of the left lower lobe.
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Adenocarcinoma Bronquioloalveolar , Adenocarcinoma/embriologíaRESUMEN
La poliangeitis microscópica (PM) hace parte de los procesos vasculíticos pulmonares, y aunque es una entidad rara, debe ser considerada en pacientes con cuadros de hemorragia alveolar masiva. En muchas ocasiones solo el análisis histológico permite establecer el diagnóstico preciso y con base en esto la toma de decisiones terapéuticas. Presentamos un caso clínico de PM manejado en el Hospital Universitario de San Ignacio (H.U.S.I.) yque fue confirmado con los estudios imagenológicos, inmunológicos e histopatológicos.
