177 research outputs found

    Evidence of the physical interaction between rpl22 and the transposable element doc5, a heterochromatic transposon of drosophila melanogaster

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    Chromatin is a highly dynamic biological entity that allows for both the control of gene expression and the stabilization of chromosomal domains. Given the high degree of plasticity observed in model and non-model organisms, it is not surprising that new chromatin components are frequently described. In this work, we tested the hypothesis that the remnants of the Doc5 transpos-able element, which retains a heterochromatin insertion pattern in the melanogaster species complex, can be bound by chromatin proteins, and thus be involved in the organization of heterochromatic domains. Using the Yeast One Hybrid approach, we found Rpl22 as a potential interacting protein of Doc5. We further tested in vitro the observed interaction through Electrophoretic Mobility Shift Assay, uncovering that the N-terminal portion of the protein is sufficient to interact with Doc5. However, in situ localization of the native protein failed to detect Rpl22 association with chromatin. The results obtained are discussed in the light of the current knowledge on the extra-ribosomal role of ribosomal protein in eukaryotes, which suggests a possible role of Rpl22 in the determination of the heterochromatin in Drosophila

    The FXR agonist obeticholic acid inhibits the cancerogenic potential of human cholangiocarcinoma

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    Cholangiocarcinoma (CCA) is an aggressive cancer with high resistance to chemotherapeutics. CCA is enriched in cancer stem cells, which correlate with aggressiveness and prognosis. FXR, a member of the metabolic nuclear receptor family, is markedly down-regulated in human CCA. Our aim was to evaluate, in primary cultures of human intrahepatic CCA (iCCA), the effects of the FXR agonist obeticholic acid (OCA), a semisynthetic bile acid derivative, on their cancerogenic potential. Primary human iCCA cell cultures were prepared from surgical specimens of mucinous or mixed iCCA subtypes. Increasing concentrations (0–2.5 μM) of OCA were added to culture media and, after 3–10 days, effects on proliferation (MTS assay, cell population doubling time), apoptosis (annexin V-FITC/propidium iodide), cell migration and invasion (wound healing response and Matrigel invasion assay), and cancerogenic potential (spheroid formation, clonogenic assay, colony formation capacity) were evaluated. Results: FXR gene expression was downregulated (RT-qPCR) in iCCA cells vs normal human biliary tree stem cells (p < 0.05) and in mucinous iCCA vs mixed iCCA cells (p < 0.05) but was upregulated by addition of OCA. OCA significantly (p < 0.05) inhibited proliferation of both mucinous and mixed iCCA cells, starting at a concentration as low as 0.05 μM. Also, CDCA (but not UDCA) inhibited cell proliferation, although to a much lower extent than OCA, consistent with its different affinity for FXR. OCA significantly induced apoptosis of both iCCA subtypes and decreased their in vitro cancerogenic potential, as evaluated by impairment of colony and spheroid formation capacity and delayed wound healing and Matrigel invasion. In general, these effects were more evident in mixed than mucinous iCCA cells. When tested together with Gemcitabine and Cisplatin, OCA potentiated the anti-proliferative and pro-apoptotic effects of these chemotherapeutics, but mainly in mixed iCCA cells. OCA abolished the capacity of both mucinous and mixed iCCA cells to form colonies when administered together with Gemcitabine and Cisplatin. In subcutaneous xenografts of mixed iCCA cells, OCA alone or combined with Gemcitabine or Cisplatin markedly reduced the tumor size after 5 weeks of treatment by inducing necrosis of tumor mass and inhibiting cell proliferation. In conclusion, FXR is down-regulated in iCCA cells, and its activation by OCA results in anti-cancerogenic effects against mucinous and mixed iCCA cells, both in vitro and in vivo. The effects of OCA predominated in mixed iCCA cells, consistent with the lower aggressiveness and the higher FXR expression in this CCA subtype. These results, showing the FXR-mediated capacity of OCA to inhibit cholangiocarcinogenesis, represent the basis for testing OCA in clinical trials of CCA patients

    Effects of probiotic bacteria (VSL#3) on the polyamine biosynthesis and cell proliferation of normal colonic mucosa of rats

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    Abstract. Background: Probiotics seem to possess tumour inhibitory properties, but few studies have investigated their actions on the cell proliferation of normal colonic mucosa. The effects of a probiotic mixture (VSL#3) on polyamine biosynthesis, Ki-67 levels and apoptosis in the normal colon of rats were studied. Materials and Methods: For a 4-week period, 20 rats were fed a VSL#3 solution and 20 rats a saline solution. Samples from the colonic mucosa were collected at the end of treatment. Polyamines were detected by HPLC, ornithine decarboxylase activity by a radiometric technique, and apoptosis and Ki-67 by histochemical and immunohistochemical methods. Results: VSL#3 caused a significant decrease in colonic polyamine levels, ornithine decarboxylase activity and Ki-67 compared to controls. A significant increase in the apoptotic index was also observed. Conclusion: Probiotics could also reduce proliferation rates in a condition not affected by hyperproliferative or neoplastic growth, when the normal control mechanisms are still completely effective

    Hepatobiliary disease resection in patients with advanced epithelial ovarian cancer: prognostic role and optimal cytoreduction

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    Objective: The purpose of this study was to evaluate the feasibility and safety in terms of prognostic significance and perioperative morbidity and mortality of cytoreduction in patients affected by advance ovarian cancer and hepato-biliary metastasis. Methods: Patients with a least one hepatobiliary metastasis who have undergone surgical treatment with curative intent of were considered for the study. Perioperative complications were evaluated and graded with Accordion severity Classification. Five-year PFS and OS were estimated using the Kaplan–Meier curve. Results: Sixty-seven (20.9%) patients had at least one metastasis to the liver, biliary tract, or porta hepatis. Forty-four (65.7%) and 23 (34.3%) patients underwent respectively high and intermediate complexity surgery according. Complete cytoreduction was achieved in 48 (71.6%) patients with hepato-biliary disease. In two patients (2.9%) severe complications related to hepatobiliary surgery were reported. The median PFS for the patients with hepato-biliary involvement (RT = 0 vs. RT &gt; 0) was 19&nbsp;months [95% confidence interval (CI) 16.2–21.8] and 8&nbsp;months (95% CI 6.1–9.9). The median OS for the patients with hepato-biliary involvement (RT = 0 vs. RT &gt; 0) 45&nbsp;months (95% CI 21.2–68.8&nbsp;months) and 23&nbsp;months (95% CI 13.9–32.03). Conclusions: Hepatobiliary involvement is often associated with high tumor load and could require high complex multivisceral surgery. In selected patients complete cytoreduction could offer survival benefits. Morbidity related to hepatobiliary procedures is acceptable. Careful evaluation of patients and multidisciplinary approach in referral centers is mandatory

    Correlates of HCV seropositivity among familial contacts of HCV positive patients

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    BACKGROUND: Determinants of intrafamilial HCV transmission are still being debated. The aim of this study is to investigate the correlates of HCV seropositivity among familial contacts of HCV positive patients in Italy. METHODS: A cross-sectional study was conducted with 175 HCV positive patients (index cases), recruited from Policlinico Gemelli in Rome as well as other hospitals in Central Italy between 1995 and 2000 (40% female, mean age 57 ± 15.2 years), and 259 familial contacts. Differences in proportions of qualitative variables were tested with non-parametric tests (χ(2), Yates correction, Fisher exact test), and a p value < 0.05 was considered significant. A multivariate analysis was conducted using logistic regression in order to verify which variables statistically have an influence on HCV positivity in contact individuals. RESULTS: Seropositivity for HCV was found in 8.9% of the contacts. From the univariate analysis, risk factors significantly associated to HCV positivity in the contacts were: intravenous drug addiction (p = 0.004) and intercourse with drug addicts (p = 0.005). The only variables associated significantly and independently to HCV seropositivity in patients' contacts were intercourse with drug addicts (OR = 19.28; 95% CI: 2.01 – 184.94), the retirement status from work (OR = 3.76; 95% CI: 1.17 – 11.98), the time of the relationship (OR = 1.06; 95% CI: 1.00 – 1.11) and tattoos (OR = 7.68; 95% CI: 1.00 – 60.20). CONCLUSION: The present study confirms that having intercourse with a drug addict is the most significant risk factor for intrafamilial HCV transmission. The association with retirement status from work could be related to both a long-term relationship with an index case and past exposure to common risk factors

    Biomimetic building-up of the carbamic moiety: the intermediacy of carboxyphosphate analogues in the synthesis of N-aryl carbamate esters from arylamines and organic carbonates promoted by phosphorus acids

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    The reaction of aromatic amines with dimethyl carbonate (DMC) or diphenyl carbonate (DPC) in the presence of organo-phosphorus acids [Ph2P(O)OH (1); (PhO)2P(O)OH (2); (BuO)2P(O)OH/(BuO)P(O)(OH)2 equimolar mixture (3)] affords carbamate esters, ArNHC(O)OR (R = Me, Ph) with high selectivity. The catalytic role played by the P-acid has been investigated and rationalized in terms of a reaction mechanism involving the intermediate formation of a carbonic-phosphinic(phosphoric) anhydride X2P(O)OC(O)OR (X = Ph, PhO; R = Me, Ph). The proposed mechanism shows intriguing analogies with the mechanism of formation of carbamate anion in living systems by carbamoyl phosphate synthetase (CPS) enzym

    Allergic contact dermatitis to topical steroids

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    The diagnosis of allergic contact dermatitis to topical corticosteroids is often difficult owing to the overlapping between the clinical features of allergic contact dermatitis and many dermatoses. Allergic contact dermatitis can be suspected when a dermatosis duly treated with topical corticosteroids fails to improve or even worsens. In a series of 6,285 patients tested from January 1997 to May 2001, according to the SIDAPA (former GIRD-CA) standard series, supplemented with tixocortole pevalate, budesonide and hydrocortisone 17-butyrrate, 65 (1.03%) showed sensitization to one or more topical corticosteroids. These data underline the importance of introducing molecules, which are "markers" of sensitization to topical corticosteroids, in patch test standard series. Patients suffering from allergic contact dermatitis to topical corticosteroids can be treated with low-sensitizing corticosteroids such as betametasone and other compounds classified in the "C" Coopman class

    Biomimetic Building-up of the Carbamic Moiety: the Intermediacy of Carboxyphosphate Analogues in the Synthesis of N-Aryl-Carbamate Esters from Arylamines and Organic Carbonates Promoted by Phosphorus Acids

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    The reaction of aromatic amines with dimethyl carbonate (DMC) or diphenyl carbonate (DPC) in the presence of organo-phosphorus acids [Ph2P(O)OH (1); (PhO)2P(O)OH (2); (BuO)2P(O)OH/(BuO)P(O)(OH)2 equimolar mixture (3)] affords carbamate esters, ArNHC(O)OR (R = Me, Ph) with high selectivity. The catalytic role played by the P-acid has been investigated and rationalized in terms of a reaction mechanism involving the intermediate formation of a carbonic-phosphinic(phosphoric) anhydride X2P(O)OC(O)OR (X = Ph, PhO; R = Me, Ph). The proposed mechanism shows intriguing analogies with the mechanism of formation of carbamate anion in living systems by carbamoyl phosphate synthetase (CPS) enzym
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