The receptor activator of nuclear factor-kappaB ligand (RANKL) and interleukin-1beta are osteoclast activating factors which are abnormally expressed in bone marrow stromal cells and plasma cells of multiple myeloma patients. In this work we analyzed RANKL expression in human bone marrow mesenchymal stromal cells and the effect of the bisphosphonate ibandronate on RANKL expression after IL-1beta activation of ERK pathway. Mesenchymal stromal cells were obtained from bone marrow iliac aspirates from multiple myeloma patients at stages II/III and non-osteoporotics control donors; these cells were maintained under long-term culture conditions.
View Article and Find Full Text PDFOsteoporosis is characterized by low bone mass, microarchitectural deterioration of bone tissue leading to increased bone fragility, and a resulting susceptibility to fractures. Distinctive environmental bone marrow conditions appear to support the development and maintenance of the unbalance between bone resorption and bone formation; these complex bone marrow circumstances would be reflected in the fluid surrounding bone marrow cells. The content of regulatory molecules in the extracellular fluid from the human bone marrow is practically unknown.
View Article and Find Full Text PDFThe purpose of this paper is to analyze the influence of the metallic structures of a realistic car body frame on the specific absorption rate (SAR) produced by a cell phone when a complete human body model is placed at different locations inside the vehicle, and to identify the relevant parameters responsible for these changes. The modeling and analysis of the whole system was conducted by means of computer simulations based on the full wave finite-difference time-domain (FDTD) numerical method. The excitation considered was an 835 MHz lambda/2 dipole located as a hands-free communication device or as a hand-held portable system.
View Article and Find Full Text PDFHuman mesenchymal stem cells (hMSCs) are multipotent cells present in bone marrow, which differentiate into osteoblasts and adipocytes, among other lineages. Oestrogens play a critical role in bone metabolism; its action may affect the adipocyte to osteoblast ratio in the bone marrow. In hMSCs, oestrogens are synthesized from C19 steroids by the enzyme aromatase cytochrome P450.
View Article and Find Full Text PDFBackground And Aims: Weight maintenance within normal standards is recommended for prevention of conditions associated with oxidative injury. To compare oxidative damage in a post mitotic tissue, between adults differing in long-term energy balance.
Methods: During hernia surgery, a sample of skeletal muscle was obtained in 17 non-obese adults.
There are disparate observations on central and peripheral effects of leptin, but several studies consistently support its role as a link between fat and bone. Bone marrow stroma contains mesenchymal stem cells (MSCs), which differentiate into osteoblasts and adipocytes, among others. In this study we assessed the expression of leptin receptors protein in MSCs from control and osteoporotic postmenopausal donors and their change during osteogenic and adipogenic differentiation.
View Article and Find Full Text PDFOsteoblasts, the cells responsible for bone formation, derive from mesenchymal stem cells (MSCs) in bone marrow. To acquire a new cell phenotype, uncommitted MSCs must undergo several proliferation and differentiation changes. Although, it is known that extracellular signal-regulated protein kinases (ERKs) mitogen-activated protein (MAP) kinase pathway signaling is involved in the proliferation and differentiation processes, the role of ERKs in osteogenic differentiation it is controversial, at present.
View Article and Find Full Text PDFCultures of skin fibroblasts show variation of androgen binding with culture conditions; binding variations are usually avoided by using confluent cultures. In this work, we analysed the effect of cell density and mitogenic agents on the level of androgen receptor (AR) of cultured human skin fibroblasts. Results demonstrated that in cultures of human skin fibroblasts, cellular binding of dihydrotestosterone was higher in cells grown at low than at high cell density.
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