1,721,024 research outputs found
Ruolo dei fattori locali nel rimodellamento osseo, in: "Osteoporosi: il parere dello specialista"
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Pathogenesis, Diagnosis and Management of Polymyalgia Rheumatica
No full textPolymyalgia rheumatica is an inflammatory rheumatic disease of the elderly characterised by pain and stiffness in the neck and pelvic girdle, and is the second most common inflammatory rheumatic condition in this age group, after rheumatoid arthritis. Polymyalgia rheumatica can occur independently or in association with giant cell arteritis, which is the most common form of primary vasculitis. The diagnosis of polymyalgia rheumatica is usually based on clinical presentation and increase of inflammatory markers. There are no pathognomonic findings that can confirm the diagnosis. However, different imaging techniques, especially ultrasonography, can assist in the identification of polymyalgia rheumatica. Glucocorticoids are the cornerstone of the treatment of polymyalgia rheumatica, but they might be associated with different adverse events. A subgroup of patients presents with a refractory disease course and, in these cases, adding methotrexate as a steroid-sparing agent could be useful. In this review, we summarise the latest findings regarding the pathogenesis, diagnosis and management of polymyalgia rheumatica and try to highlight the possible pitfalls, especially in elderly patients
Telopeptide C-Terminale del collageno I nel siero: un indice sensibile dell’inibizione intermittente del riassorbimento osseo durante la somministrazione ciclica di alendronato
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Estrogen, cytokines, and the control of osteoclast formation and bone resorption in vitro and in vivo
No full textIncreased interleukin-6 production by murine bone marrow and bone cells after estrogen withdrawal
No full textWe have previously shown that cytokine-induced production of interleukin-6 (IL-6) by cultured bone marrow-derived stromal and osteoblastic cells is inhibited by 17 beta-estradiol, and that estrogen withdrawal (ovariectomy) in mice causes an up-regulation of osteoclast development which can be prevented by a neutralizing antibody against IL-6 or estrogen replacement. To directly establish the link between estrogen loss and altered IL-6 production, implied by our earlier studies, we have now compared IL-6 production in ex vivo cultures of bone marrow cells from mice that were sham operated, ovariectomized, or ovariectomized and treated with 17 beta-estradiol. In addition, we have examined the effect of the in vitro withdrawal of estrogens from primary cell cultures of neonatal murine calvaria on IL-6 production. IL-6 production in ex vivo cultures of bone marrow cells maintained in the presence of 1,25-dihydroxyvitamin D3 or PTH was greater in marrow cells from ovariectomized mice than in those from sham-operated animals or ovariectomized animals receiving estrogen replacement. In line with this finding, addition of 17 beta-estradiol to calvaria cell cultures followed by withdrawal of the steroid caused an increase in the amount of IL-6 produced in response to the subsequent stimulation of these cultures with IL-1 or PTH compared to that in cultures that had never been treated with estradiol; when the inactive isomer 17 alpha- estradiol was used, no change in IL-6 production was observed. These results establish that estrogen loss causes an up-regulation of IL-6 production by bone marrow cells and that a similar phenomenon can be elicited in vitro by withdrawal of 17 beta-estradiol from primary cultures of bone cells
Bisphosphonates inhibit IL-6 production by human osteoblast-like cells
No full textSince bisphosphonates prevent bone loss in osteoporosis and rheumatoid arthritis, diseases in which the osteoclastogenic and inflammatory cytokine interleukin-6 plays a pathophysiologic role, we studied whether these drugs regulate the production of this cytokine by osteoblasts. Spontaneous and IL-1 + TNF-alpha stimulated IL-6 release was measured in supernatants of cultures of human osteoblastic osteosarcoma cells MG-63, pretreated for 4 hours with different doses of etidronate, clodronate or alendronate using a specific bioassay. Etidronate [from 10(-4) to 10(-8) M] or alendronate [from 10(-6) to 10(-11) M] inhibited in a dose-dependent manner the cytokine-induced IL-6 secretion [60+/-9.5% at 10(-5) M and 65+/-12% at 10(-7) M, respectively; p < 0.01]. Though significant, the inhibitory effect of clodronate was less [35+/-7% at 10(-5) M, p < 0.05]. These in vitro observations might have in vivo relevance in explaining at least in part the mechanisms by which bisphosphonates inhibit systemic and periarticular bone resorption
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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