Browsing by Subject "Fibroblast"

Now showing 1 - 5 of 5
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    Emerging role of tissue lectins as microenvironmental effectors in tumors and wounds
    (F. Hernández y Juan F. Madrid. Universidad de Murcia: Departamento de Biología Celular e Histología, 2015) Smetana, Karel Jr.; Szabo, Pavol; Gál, Peter; André, Sabine; Gabius, Hans-Joachim; Kodet, Ondřej; Dvořánková, Barbora
    Detailed comparative analysis of at first sight not related process cascades is a means toward this aim: to trace common effector mechanisms and hereby eventually inspire innovative routes for therapeutic management. Following this concept, promotion of tumor progression by stroma, especially cancerassociated fibroblasts and smooth muscle actin-positive myofibroblasts, and beneficial activity of respective cells in wound healing have helped to delineate the involvement of endogenous lectins of the family of galectins. In addition to initiating conversion of fibroblasts to myofibroblasts, galectin-1 instructs the cells to produce a structurally complex extracellular matrix. This bioscaffold is useful for keratinocyte culture, also apparently operative in ameliorating wound healing. These functional aspects encourage to study in detail how lectin-(glycan) counterreceptor display is orchestrated. Such insights are assumed to have potential to contribute to rationally manipulate stem/precursor cells as resource in regenerative medicine.
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    Histological changes in connective tissue of rat tails after bipolar radiofrequency treatment
    (F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología, 2012) Bernal-Mañas, C.M.; Navarro, S.; Zuasti Elizondo, Adelina; Ferrer Cazorla, Concepción; Canteras Jordana, Manuel; García Collado, Angel Joaquín; Beltrán Frutos, Ester; Pastor García, Luis Miguel; Seco Rovira, Vicente; Facultades, Departamentos, Servicios y Escuelas::Departamentos de la UMU::Biología Celular e Histología
    Radiofrequency (RF) has been included in the techniques used in aesthetic surgery/medicine. To date, no studies have performed a histological assessment of changes in the tissue after application of bipolar radiofrequency (BRF) with low energy and frequency. The aim of this study was to examine changes that are produced in connective tissue, principally in the fibroblasts, following BRF treatment. Four groups of rats received a different number of RF sessions (1, 2, 3 and 5). The following parameters were determined: the number of fibroblasts/unit area (FA), the proliferation index (PI), the Heat shock Protein 47 index (HSPI) and the percentage of connective tissue (PC). For statistical analysis, two subgroups (A and B) were made for the variables FA, PI and PC, and another two subgroups (C and D) for the variable HSPI. Significant differences for FA, PI and PC were observed between subgroups A and B, FA and PI having higher values in A, while PC had higher values in B. The HSPI in subgroup C showed significantly higher values than in D. Low energy and frequency BRF led to an increase in the number, proliferation and biosynthetic activity of fibroblasts. The resulting stress suffered by fibroblasts as a result of heat may be associated with the phenomenon of hormesis
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    Metamorphosed fibroblasts and their relation to the histogenesis of malignant fibrous histiocytoma in experimental murine model
    (Murcia : F. Hernández, 2000) Osanai, T.; Yamakawa, Mitsunori; Suda, A.; Watanabe, Y.
    Malignant fibrous histiocytoma (MFH) is a clinicopathologically established entity, but its histogenesis remains to be clarified. We have reported the existence of a specific cell type, the "fibrohistiocytoid (FH) cells", in various chronic inflammatory tissues. The FH cells are the metamorphosed fibroblasts and we have revealed the morphological resemblance between FH cells and MFH cells. In the present study we carried out some experiments to ascertain whether the FH cells have a possibility of neoplastic potential for the development of MFH in mice. A total of 50 female Balb/c mice treated with a chemical carcinogen, 9,lOdimethyl- 1,2-benzanthracene (DMBA), were examined histopathologically from 8 to 22 weeks after the initial treatment. It was found that 1) the chemically induced tumors in the mice resembled human pleomorphic/ storiform variant of MFH and cells from the tumor were transplantable subcutaneously in the back of another mouse, 2) the tumors were composed mainly of malignant FH cells, and there were many benign FH cells and fibroblasts in granulation tissues obtained at the initial stage of the experiment, 3) all DNA histograms obtained from MFHs were aneuploid and granulation tissues were diploid, and 4) benign FH cells in the granulation tissue appeared to have higher DNA synthesis activity than typical fibroblasts on the basis of bromodeoxyuridine (BrdU) labeling and cytofluorometric studies. From these findings, we suggest that the FH cells are not only a merely morphologically changed fibroblast, but also a biologically ominous cell which may contribute to develop MFH in mice.
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    Preservation of human skin structure and function in organ culture
    (Murcia : F. Hernández, 1998) Varani, J.
    Human keratinocytes can be maintained in monolayer culture under serum-free conditions for an extended period of time. Under low ca2+ conditions (e.g., 0.05-0.15 mM), an undifferentiated state is maintained and the cells proliferate optimally. When the ca2+ concentration is raised to approximately 1.0 mM, differentiation occurs and growth slows. Human dermal fibroblasts can also be maintained in monolayer culture under serum-free conditions, but in contrast to keratinocytes, a physiological level of extracellular ca2+ (above approximately 1.0 mM) is required. A variety of growth factors stimulate roliferation of both cell types but do not replace the CaP+ requirement of the fibroblast population. All-trans retinoic acid also promotes proliferation of both cell types and, most interestingly, replaces the requirement for a physiological level of ca2+ in the fibroblast cultures. Human skin can be maintained in organ culture for an extended period of time under serum-free conditions. Conditions optimized for fibroblast proliferation (either physiological ca2+ or all-trans retinoic acid) are required. In the presence of culture conditions optimized for the epithelial cell component, both the epidermis and dermis rapidly lyse. These data suggest that the fibroblast is the critical component in maintaining homeostasis of skin, and that maintenance of the epidermis as well as the dermis depends on the viability and functioning of these cells.
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    Sinusoidal 50 Hz magnetic fields do not affect structural morphology and proliferation of human cells in vitro
    (Murcia : F. Hernández, 2001) Supino, R.; Bottone, M.G.; Pellicciari, C.; Caserini, C.; Bottiroli, G.; Belleri, M.; Veicsteinas, A.
    The effects of electromagnetic fields on severa1 processes related to cell physiology and proliferation are currently being investigated. Although the results are still not conclusive and even conflicting, there seems to be a fairly good agreement on the early effects of electromagnetic fields on the generation of free radicals and on Ca++-intracellular concentration and transport. To evaluate the long-lasting consequences of these precocious events, we examined the effects of short- and long-term magnetic field exposure on structural organization (cytokeratin or actin detection), proliferation (bromodeoxyuridine incorporation and propidium iodide staining), colony forming ability and viability (trypan blue exclusion test) of highly proliferating MCF-7 cells (from human breast carcinoma) and on slowly proliferating normal human fibroblasts (from healthy donors). Cells were exposed to either 20 or 500 pT sinusoidally oscillating (50Hz) magnetic fields for different lengths of time (1 to 4 days). Short (1 day)- and long (4 days)-time exposure to the two intensities did not affect MCF-7 growth and viability, colony number and size, or cellular distribution along the cell cycle; neither were the cell morphology and the intracellular distribution and amount of cytokeratin modified. Similarly, no modifications in the actin distribution and proliferative potential were observed in normal human fibroblasts. These findings suggest that under our experimental conditions, continuous exposure to magnetic fields does not result in any appreciable effect in both normal and tumor cells in vitro.