62 research outputs found

    Osteoclast Activated FoxP3+ CD8+ T-Cells Suppress Bone Resorption in vitro

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    BACKGROUND: Osteoclasts are the body's sole bone resorbing cells. Cytokines produced by pro-inflammatory effector T-cells (T(EFF)) increase bone resorption by osteoclasts. Prolonged exposure to the T(EFF) produced cytokines leads to bone erosion diseases such as osteoporosis and rheumatoid arthritis. The crosstalk between T-cells and osteoclasts has been termed osteoimmunology. We have previously shown that under non-inflammatory conditions, murine osteoclasts can recruit naĂŻve CD8 T-cells and activate these T-cells to induce CD25 and FoxP3 (Tc(REG)). The activation of CD8 T-cells by osteoclasts also induced the cytokines IL-2, IL-6, IL-10 and IFN-Îł. Individually, these cytokines can activate or suppress osteoclast resorption. PRINCIPAL FINDINGS: To determine the net effect of Tc(REG) on osteoclast activity we used a number of in vitro assays. We found that Tc(REG) can potently and directly suppress bone resorption by osteoclasts. Tc(REG) could suppress osteoclast differentiation and resorption by mature osteoclasts, but did not affect their survival. Additionally, we showed that Tc(REG) suppress cytoskeletal reorganization in mature osteoclasts. Whereas induction of Tc(REG) by osteoclasts is antigen-dependent, suppression of osteoclasts by Tc(REG) does not require antigen or re-stimulation. We demonstrated that antibody blockade of IL-6, IL-10 or IFN-Îł relieved suppression. The suppression did not require direct contact between the Tc(REG) and osteoclasts. SIGNIFICANCE: We have determined that osteoclast-induced Tc(REG) can suppress osteoclast activity, forming a negative feedback system. As the CD8 T-cells are activated in the absence of inflammatory signals, these observations suggest that this regulatory loop may play a role in regulating skeletal homeostasis. Our results provide the first documentation of suppression of osteoclast activity by CD8 regulatory T-cells and thus, extend the purview of osteoimmunology

    Adenosquamous carcinoma of the colon. Case report of an unusual type.

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    Primary adenosquamous carcinoma of the colon is a rare entity. Its prevalent site of origin is at the level of the proximal portion of the large bowel. The tumor presents in young patients and follows a highly aggressive course. We present an extremely unusual case of adenosquamous carcinoma in which the classical mucinous and signet-ring cell adenocarcinoma was associated with the squamous component. The prognosis of this rare neoplasm is very poor

    Enterobius vermicularis granuloma of the ovary: Report of a case with diagnosis by intraoperative cytology

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    The relationship of 3'vitamin D receptor haplotypes to urinary supersaturation of calcium oxalate salts and to age at onset and familial prevalence of nephrolithiasis

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    Idiopathic hypercalciuria (IHc) and idiopathic hypocitraturia are frequently associated with calcium nephrolithiasis. We investigated the relationship of vitamin D receptor (VDR) polymorphisms (BsmI, TaqI and FokI) to urinary supersaturation of calcium oxalate salts in recurrent calcium oxalate stone formers with IHc and the clinical relevance of this relationship.The study included 110 Caucasian stone formers with IHc and 127 unrelated healthy controls without history of nephrolithiasis. Age at onset of nephrolithiasis, familial history score (FHS) and the ion activity product of calcium oxalate salts in urine (AP(CaOx)) were tabulated. BsmI, TaqI and FokI VDR polymorphisms were evaluated in all participants.Patients and controls were classified as homozygous (bbTT and BBtt) or heterozygous in relation to BsmI and TaqI polymorphisms. Compared with BBtt patients, bbTT homozygous stone formers showed lower citrate excretion (1.91+/-0.89 vs 3.46+/-1.39 mmol/24 h, P = 0.004) and higher AP(CaOx) (2.02+/-0.51 vs 1.53+/-0.53, P = 0.006). Among controls, there were similar differences in citrate excretion and AP(CaOx) between the two groups, but they were not statistically significant. Compared with BBtt, bbTT patients showed lower mean age at onset of nephrolithiasis (29.7+/-12.1 vs 38.1+/-12.7 years, P = 0.008) and higher values of FHS (2.45+/-1.9 vs 0.83+/-0.7, P = 0.006). Similar results were obtained for individual BsmI and TaqI alleles. The analysis of FokI alleles was not informative.Recurrent calcium oxalate stone formers with IHc and the bT VDR haplotype have more aggressive kidney stone diseases as indicated by a higher familial incidence and lower mean age at onset. This clinical severity is associated with the higher urinary supersaturation of calcium oxalate salts and abnormalities of renal citrate handling
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