48 research outputs found

    The radiosensitizing effect of Ku70/80 knockdown in MCF10A cells irradiated with X-rays and p(66)+Be(40) neutrons

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    Background: A better understanding of the underlying mechanisms of DNA repair after low-and high-LET radiations represents a research priority aimed at improving the outcome of clinical radiotherapy. To date however, our knowledge regarding the importance of DNA DSB repair proteins and mechanisms in the response of human cells to high-LET radiation, is far from being complete. Methods: We investigated the radiosensitizing effect after interfering with the DNA repair capacity in a human mammary epithelial cell line (MCF10A) by lentiviral-mediated RNA interference (RNAi) of the Ku70 protein, a key-element of the non-homologous end-joining (NHEJ) pathway. Following irradiation of control and Ku-deficient cell lines with either 6 MV X-rays or p(66)+Be(40) neutrons, cellular radiosensitivity testing was performed using a crystal violet cell proliferation assay. Chromosomal radiosensitivity was evaluated using the micronucleus (MN) assay. Results: RNAi of Ku70 caused downregulation of both the Ku70 and the Ku80 proteins. This downregulation sensitized cells to both X-rays and neutrons. Comparable dose modifying factors (DMFs) for X-rays and neutrons of 1.62 and 1.52 respectively were obtained with the cell proliferation assay, which points to the similar involvement of the Ku heterodimer in the cellular response to both types of radiation beams. After using the MN assay to evaluate chromosomal radiosensitivity, the obtained DMFs for X-ray doses of 2 and 4 Gy were 2.95 and 2.66 respectively. After neutron irradiation, the DMFs for doses of 1 and 2 Gy were 3.36 and 2.82 respectively. The fact that DMFs are in the same range for X-rays and neutrons confirms a similar importance of the NHEJ pathway and the Ku heterodimer for repairing DNA damage induced by both X-rays and p(66)+Be(40) neutrons. Conclusions: Interfering with the NHEJ pathway enhanced the radiosensitivity of human MCF10A cells to low-LET Xrays and high-LET neutrons, pointing to the importance of the Ku heterodimer for repairing damage induced by both types of radiation. Further research using other high-LET radiation sources is however needed to unravel the involvement of DNA double strand break repair pathways and proteins in the cellular response of human cells to high-LET radiation

    Prevention and modulation of aminoglycoside ototoxicity (Review)

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    More than 60 years after their isolation and characterization, aminoglycoside (AG) antibiotics remain powerful agents in the treatment of severe gram-negative, enterococcal or mycobacterial infections. However, the clinical use of AGs is hampered by nephrotoxicity and ototoxicity, which often develop as a consequence of prolonged courses of therapy, or of administration of increased doses of these drugs. The discovery of non-ototoxic antibacterial agents, showing a wider spectrum of activity, has gradually decreased the use of AGs as first line antibiotics for many systemic infections. However, AGs are now undergoing an unexpected revival, being increasingly indicated for the treatment of severe emerging infections caused by organisms showing resistance to most first-line agents (e.g., multidrug-resistant tuberculosis, complicated nosocomially-acquired acute urinary tract infections). Increasing adoption of aminoglycosides poses again to scientists and physicians the problem of toxicity directed to the kidneys and to the inner ear. In particular, aminoglycoside-induced deafness can be profound and irreversible, especially in genetically predisposed patients. For this reason, an impressive amount of molecular strategies have been developed in the last decade to counteract the ototoxic effect of aminoglycosides. The present article overviews: i) the molecular mechanisms by which aminoglycosides exert their bactericidal activity, ii) the mechanisms whereby AGs exert their ototoxic activity in genetically-predisposed patients, iii) the drugs and compounds that have so far proven to prevent or modulate AG ototoxicity at the preclinical and/or clinical level, and iv) the dosage regimens that have so far been suggested to decrease the incidence of episodes of AG-induced ototoxicity

    Prognostic value of CXCL12 expression in 40 low-grade oligodendrogliomas and oligoastrocytomas.

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    Both clinical and biological features have been reported as prognostic factors in low-grade gliomas. Among these, histotype, tumor size, enhancement, age and genetic pattern. Microvessel density (MVD) has been correlated to clinical outcome in astrocytomas, but its impact in oligodendrogliomas and mixed tumors is not sure. The pro-angiogenic chemokine stromal cell-derived factor (SDF-1/CXCL12) and its receptor CXC chemokine receptor 4 (CXCR4) have been described in low-grade gliomas, with a correlation between CXCL12 expression and shorter time to progression (TTP). The intermediate filament Nestin is expressed in proliferating vessels. Platelet-derived growth factor B (PDGF-B) and its receptor PDGFR-beta are also involved in angiogenesis and malignant progression in gliomas

    Free and poly-methyl-methacrylate-bounded BODIPYs: photodynamic and antimigratory effects in 2D and 3D cancer models

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    Several limitations, including dark toxicity, reduced tumor tissue selectivity, low photostability and poor biocompatibility hamper the clinical use of Photodynamic therapy (PDT) in cancer treatment. To overcome these limitations, new PSs have been synthetized, and often combined with drug delivery systems, to improve selectivity and reduce toxicity. In this context, BODIPYs (4,4-difluoro-4-bora-3a,4a-diaza-s-indacene) have recently emerged as promising and easy-to-handle scaffolds for the preparation of effective PDT antitumor agents. In this study, the anticancer photodynamic effect of newly prepared negatively charged polymethyl methacrylate (nPMMA)-bounded BODIPYs (3@nPMMA and 6@nPMMA) was evaluated on a panel of 2D- and 3D-cultured cancer cell lines and compared with free BODIPYs. In particular, the effect on cell viability was evaluated, along with their ability to accumulate into the cells, induce apoptotic and/or necrotic cell death, and inhibit cellular migration. Our results indicated that 3@nPMMA and 6@nPMMA reduce cancer cell viability in 3D models of HC116 and MCF7 cells more effectively than the corresponding free compounds. Importantly, we demonstrated that MDA-MB231 and SKOV3 cell migration ability was significantly impaired by the PDT treatment mediated by 3@nPMMA and 6@nPMMA nanoparticles, likely indicating the capability of this approach to reduce metastatic tumor potential

    Evaluation of Nanoparticles Covalently Bound with BODIPY for Their Photodynamic Therapy Applicability

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    Photodynamic therapy (PDT) relies on the combined action of a photosensitizer (PS), light at an appropriate wavelength, and oxygen, to produce reactive oxygen species (ROS) that lead to cell death. However, this therapeutic modality presents some limitations, such as the poor water solubility of PSs and their limited selectivity. To overcome these problems, research has exploited nanoparticles (NPs). This project aimed to synthesize a PS, belonging to the BODIPY family, covalently link it to two NPs that differ in their lipophilic character, and then evaluate their photodynamic activity on SKOV3 and MCF7 tumor cell lines. Physicochemical analyses demonstrated that both NPs are suitable for PDT, as they are resistant to photobleaching and have good singlet oxygen (1O2) production. In vitro biological analyses showed that BODIPY has greater photodynamic activity in the free form than its NP-bounded counterpart, probably due to greater cellular uptake. To evaluate the main mechanisms involved in PDT-induced cell death, flow cytometric analyses were performed and showed that free BODIPY mainly induced necrosis, while once bound to NP, it seemed to prefer apoptosis. A scratch wound healing test indicated that all compounds partially inhibited cellular migration of SKOV3 cells

    Acute Delta Hepatitis in Italy spanning three decades (1991–2019): Evidence for the effectiveness of the hepatitis B vaccination campaign

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    Updated incidence data of acute Delta virus hepatitis (HDV) are lacking worldwide. Our aim was to evaluate incidence of and risk factors for acute HDV in Italy after the introduction of the compulsory vaccination against hepatitis B virus (HBV) in 1991. Data were obtained from the National Surveillance System of acute viral hepatitis (SEIEVA). Independent predictors of HDV were assessed by logistic-regression analysis. The incidence of acute HDV per 1-million population declined from 3.2 cases in 1987 to 0.04 in 2019, parallel to that of acute HBV per 100,000 from 10.0 to 0.39 cases during the same period. The median age of cases increased from 27 years in the decade 1991-1999 to 44 years in the decade 2010-2019 (p < .001). Over the same period, the male/female ratio decreased from 3.8 to 2.1, the proportion of coinfections increased from 55% to 75% (p = .003) and that of HBsAg positive acute hepatitis tested for by IgM anti-HDV linearly decreased from 50.1% to 34.1% (p < .001). People born abroad accounted for 24.6% of cases in 2004-2010 and 32.1% in 2011-2019. In the period 2010-2019, risky sexual behaviour (O.R. 4.2; 95%CI: 1.4-12.8) was the sole independent predictor of acute HDV; conversely intravenous drug use was no longer associated (O.R. 1.25; 95%CI: 0.15-10.22) with this. In conclusion, HBV vaccination was an effective measure to control acute HDV. Intravenous drug use is no longer an efficient mode of HDV spread. Testing for IgM-anti HDV is a grey area requiring alert. Acute HDV in foreigners should be monitored in the years to come

    Antimicrobial therapy for chronic bacterial prostatitis.

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    Chronic bacterial prostatitis (CBP) is frequently diagnosed in men of fertile age, and is characterized by a disabling array of symptoms, including pain in the pelvic area (for example, perineum, testicles), voiding symptoms (increased frequency and urgency, also at night; pain or discomfort at micturition), and sexual dysfunction. Cure of CBP can be attempted by long-term therapy with antibacterial agents, but relapses are frequent. Few antibacterial agents are able to distribute to the prostatic tissue and achieve sufficient concentrations at the site of infection. These agents include fluoroquinolones, macrolides, tetracyclines and trimethoprim. After the introduction of fluoroquinolones into clinical practice, a number of studies have been performed to optimize the antimicrobial treatment of CBP, and to improve eradication rates and symptom relief.To assess and compare the efficacy and harm of antimicrobial treatments for chronic bacterial prostatitis.We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (PubMed), EMBASE, other national or international databases and abstracts from conference proceedings on 8 August 2012.We included all randomized controlled comparisons of one antimicrobial agent versus placebo or one or more comparator antimicrobial agents, combined or not with non-antimicrobial drugs. We also included trials comparing different doses, treatment durations, dosing frequencies, or routes of administration of antimicrobial agents. We excluded studies in which patients were not diagnosed according to internationally recommended criteria, or were not subjected to lower urinary tract segmented tests.Study data were extracted independently by two review authors. Study outcomes were microbiological efficacy (pathogen eradication), clinical efficacy (symptom cure or improvement, or symptom scores) at test-of-cure visits or at follow-up, or both, and adverse effects of therapy. Secondary outcomes included microbiological recurrence rates.Statistical analysis was performed using a fixed-effect model for microbiological outcomes and a random-effects model for clinical outcomes and adverse effects. The results were expressed as risk ratios for dichotomous outcomes (with 95% confidence intervals) or as standardized mean differences for continuous or non-dichotomous variables.We identified 18 studies, enrolling a total of 2196 randomized patients. The oral fluoroquinolones ciprofloxacin, levofloxacin, lomefloxacin, ofloxacin and prulifloxacin were compared. There were no significant differences in clinical or microbiological efficacy or in the rate of adverse effects between these fluoroquinolones. In chlamydial prostatitis, (i) azithromycin showed improved eradication rates and clinical cure rates compared to ciprofloxacin, with no significant differences regarding adverse effects; (ii) azithromycin was equivalent to clarithromycin, both microbiologically and clinically; (iii) prulifloxacin appeared to improve clinical symptoms, but not eradication rates, compared to doxycycline. In ureaplasmal prostatitis, the comparisons ofloxacin versus minocycline and azithromycin versus doxycycline showed similar microbiological, clinical and toxicity profiles.The microbiological and clinical efficacy, as well as the adverse effect profile, of different oral fluoroquinolones are comparable. No conclusions can be drawn regarding the optimal treatment duration of fluoroquinolones in the treatment of CBP caused by traditional pathogens.Alternative antimicrobial agents tested for the treatment of CBP caused by traditional pathogens are co-trimoxazole, beta-lactams and tetracyclines, but no conclusive evidence can be drawn regarding the role of non-fluoroquinolone antibiotics in the treatment of CBP caused by traditional pathogens.In patients with CBP caused by obligate intracellular pathogens, macrolides showed higher microbiological and clinical cure rates compared to fluoroquinolones
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