17 research outputs found

    Epithelial morphology of duodenal bulb and Campylobacter-like organisms.

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    We have carried out ultramicroscopical investigations on 30 patients with endoscopical aspects of congestive or erosive duodenitis associated or not with bulbar ulcer in relation to the presence of Campylobacter-like organisms (CLO), considered as a possible etiologic agent of peptic disease. Bacteria were found in all of the 14 patients with duodenal ulcer and in only five patients without ulcer. The ultrastructural studies provided elements for the evaluation of epithelial colonization of the duodenal bulb by CLO and which may lead to a new interpretation of gastric metaplasia

    Effects of Electromagnetic Field and Insulin Growth Factor-I on Proteoglycan Synthesis in Bovine Articular Cartilage

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    Effects of Electromagnetic Field and Insulin Growth Factor-I on Proteoglycan Synthesis in Bovine Articular Cartilage by in vitro cultured cells

    Effects of electromagnetic fields on proteoglycan metabolism of bovine articular cartilage explants

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    Electromagnetic field (EMF) exposure has been proposed for the treatment of osteoarthritis. In this study, we investigated the effects of EMF (75 Hz, 2,3 mT) on proteoglycan (PG) metabolism of bovine articular cartilage explants cultured in vitro, both under basal conditions and in the presence of interleukin-1beta (IL-1beta) in the culture medium. Proteoglycan synthesis and the residual PG tissue content resulted significantly higher in EMF-exposed explants than in controls, whereas no effect was observed on PG release and nitric oxide (NO) production. IL-1beta induced both a reduction in PG synthesis and an increase in PG release, related to a strong stimulation of NO production, which resulted in a net loss of tissue PG content. In IL-1beta-treated explants, EMF increased PG synthesis, whereas in spite of a slight stimulation of NO production EMF did not modify PG release. This resulted in the residual PG tissue content being maintained at the control level. In both experimental conditions, the effects of EMF were associated with an increase in lactate production. The results of our study show that EMFs are able to promote anabolic activities and PG synthesis in bovine articular cartilage explants. This effect also is maintained in the presence of IL-1beta, thus counteracting the catabolic activity of the cytokine. Altogether, these data suggest that EMF exposure exerts a chondroprotective effect on articular cartilage in vitro

    Glycosaminoglycan, collagen, and glycosidase changes in human osteoblasts treated with interleukin 1, and osteodystrophy.

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    Normal bone homeostasis involves a balance between osteoblast and osteoclast action, regulated by hormones and cytokine stimuli. Hemodialysis patients appear to have increased production of interleukin-1 (IL-1), interleukin-6 (IL-6) and glycosaminoglycans (GAG) in serum. IL-1 plays a role in the synthesis, degradation and degree of sulphatation of ECM components such as glycosaminoglycans. Also, continuous changes in the ECM involve enzymes such as beta-N-acetyl-d-glucosaminidase (beta-NAG) and beta-d-glucuronidase (beta-GLU) which act on different GAG classes and collagen fibers. We examined the effects of IL-1alpha on ECM synthesis and the related enzymes in human uremic osteoblast cultures. We also measured the levels of IL-1beta, and IL-6 and alkaline phosphatase activity. In biopsies of uremic bone there was less ECM deposition than resorption associated with changes in osteoblast morphology. In vitro osteoblast proliferation was higher (P</=0.01), and extracellular GAG lower (P</=0.01) than in controls. The enzyme beta-NAG was high (P</=0.05) but there were no noteworthy changes in beta-GLU. ELISA of the medium indicated spontaneous production of IL-1beta and IL-6, which significantly increased after IL-1alpha treatment compared to controls. IL-1alpha reduced alkaline phosphatase activity (P</=0.01) in uremic osteoblast cultures. IL-1 acts on osteoblasts with decreases in GAG synthesis and alkaline phosphatase activity, while beta-NAG increases. This lead to a reduction in the organic component in ECM and its mineralization, and to changes in the regulation of cytokine activity by GAG. The enzymatic breakdown might be facilitated by metabolic acidosis and failed osteoblast differentiation; these factors could be correlated with different degrees of osteodystrophy

    Ornithine decarboxylase, polyamines and CD11b expression in HL-60 cells during differentiation induced by retinoic acid

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    Polyamines (PA) and retinoic acid affect mammalian cell growth, differentiation and apoptosis. Retinoic acid induces granulocytic differentiation of mieloid cell lines and, during this process, is responsible for the expression of CD11b, a surface antigen. In this study we investigate the effects of retinoic acid on HL-60 cells, monitoring ornithine decarboxylase (ODC) activity (enzyme rate of PA), putrescine (PUT), spermidine (SPD), spermine (SPM) levels, CD11b myeloid surface marker differentiation, cell cycle, and apoptosis. ODC activity and PUT levels are correlated with mieloid cell differentiation induced by retinoic acid treatment. Only the ODC/PUT ratio is connected with retinoic acid treated HL-60 cells. Treated cultures show a decrease of proliferation and a cell block in the G0/G1 phase, with consequent diminished S phase. The G0/G1 and S phases are significantly related to ODC activity and to PUT and SPD behavior, whereas in differentiating condition only the decrease of PUT is related to the S phase. CD11b expression, stimulated by retinoic acid treatment, is associated with the SPM trend. Total PA behavior agrees with apoptotic cell increase after 96 h of stimulation. Our data show that retinoic acid treatment modifies ODC activity and the turnover of PA. PUT, SPD and SPM, therefore, have a different role, and may be involved in the differentiative/apoptotic program of retinoic acid treated HL-60 cells
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