Secondary metabolite from Pseudomonas aeruginosa LV strain exhibits antibacterial activity against Staphylococcus aureus: Metabólito secundário de Pseudomonas aeruginosa cepa LV exibe atividade antibacteriana em Staphylococcus aureus

This study aimed to evaluate the antibacterial activity of the dichloromethane/ethyl acetate fraction (named F4a), obtained from the culture of Pseudomonas aeruginosa LV strain in presence of copper chloride, against planktonic and sessile cells of Staphylococcus aureus, including those presenting multidrug resistance. First, the minimal inhibitory concentrations (MIC) of F4a for twenty-six clinical isolates were determined and the values ranged from 1.56 to 6.25 µg/mL. Minimal bactericidal concentration (MBC) of 3.13 µg/mL was detected in 84.6% of the isolates. The time-kill curve analysis revealed a significant decreased in colony-forming unit counts after 4 h of treatment with the MIC/MBC of F4a. Moreover, the MIC/MBC of the fluopsin C, a copper-containing compound present in F4a, were 1.56/3.13 µg/mL, indicating that this compound seems to be one of the active components related to the antibacterial activity against S. aureus. Images of transmission electron microscopy showed significant ultrastructural alterations in planktonic cells treated with the MIC/MBC of F4a. A significant reduction in the metabolic activity of established biofilms of all S. aureus isolates was observed after treatment with F4a. No hemolytic activity to human erythrocytes was detected for F4a, and the cytotoxic concentration to LLC-MK2 cells was 3.44 µg/mL. In conclusion, F4a exhibited a bactericidal activity against planktonic cells and inhibited the metabolic activity of biofilms of S. aureus. F4a can be promising for the development of new strategies for the treatment of infections caused by S. aureus

Antifungal Combination of Ethyl Acetate Extract of Poincianella pluviosa (DC.) L. P. Queiros Stem Bark With Amphotericin B in Cryptococcus neoformans

Cryptococcus neoformans is the leading cause of cryptococcosis, an invasive and potentially fatal infectious disease. Therapeutic failures are due to the increase in antifungal resistance, the adverse effects of drugs, and the unavailability of therapeutic regimens in low-income countries, which limit the treatment of cryptococcosis, increasing the morbidity and mortality associated with these infections. Thus, new antifungal drugs and innovative strategies for the cryptococcosis treatment are urgently needed. The aim of the present study was to evaluate the effect of ethyl acetate fraction (EAF) of Poincianella pluviosa stem bark on planktonic and biofilm mode of growth of C. neoformans. Furthermore, the interaction between the EAF and amphotericin B (AmB) was evaluated in vitro and in Galleria mellonella infection model. Minimal inhibitory concentrations (MICs) of EAF ranged from 125.0 to >1,000.0 μg/ml and >1,000.0 μg/ml for planktonic and sessile cells, respectively. The combination between EAF and AmB exhibited a synergistic fungicidal activity toward C. neoformans, with a fractional inhibitory concentration index (FICI) ranging from 0.03 to 0.06 and 0.08 to 0.28 for planktonic and sessile cells, respectively. Microscopy analyses of planktonic C. neoformans cells treated with EAF, alone or combined with AmB, revealed morphological and ultrastructural alterations, including loss of integrity of the cell wall and cell membrane detachment, suggesting leakage of intracellular content, reduction of capsule size, and presence of vacuoles. Moreover, EAF alone or combined with AmB prolonged the survival rate of C. neoformans-infected G. mellonella larvae. These findings indicate that P. pluviosa may be an important source of new compounds that can be used as a fungus-specific adjuvant for the treatment of cryptococcosis

MiR-16 regulates the pro-tumorigenic potential of lung fibroblasts through the inhibition of HGF production in an FGFR-1- and MEK1-dependent manner

Abstract Background Fibroblasts are crucial mediators of tumor-stroma cross-talk through synthesis and remodeling of the extracellular matrix and production of multiple soluble factors. Nonetheless, little is still known about specific determinants of fibroblast pro-tumorigenic activity in lung cancer. Here, we aimed at understanding the role of miRNAs, which are often altered in stromal cells, in reprogramming fibroblasts towards a tumor-supporting phenotype. Methods We employed a co-culture-based high-throughput screening to identify specific miRNAs modulating the pro-tumorigenic potential of lung fibroblasts. Multiplex assays and ELISA were instrumental to study the effect of miRNAs on the secretome of both primary and immortalized lung fibroblasts from lung cancer patients and to evaluate plasmatic levels of HGF in heavy smokers. Direct mRNA targeting by miRNAs was investigated through dual-luciferase reporter assay and western blot. Finally, the pro-tumorigenic activity of fibroblasts and their conditioned media was tested by employing in vitro migration experiments and mouse xenografts. Results We identified miR-16 as a master regulator of fibroblast secretome and showed that its upregulation reduces HGF secretion by fibroblasts, impairing their capacity to promote cancer cell migration. This effect is due to a pleiotropic activity of miR-16 which prevents HGF expression through direct inhibition of FGFR-1 signaling and targeting of HGF mRNA. Mechanistically, miR-16 targets FGFR-1 downstream mediator MEK1, thus reducing ERK1/2 activation. Consistently, chemical or genetic inhibition of FGFR-1 mimics miR-16 activity and prevents HGF production. Of note, we report that primary fibroblast cell lines derived from lungs of heavy smokers express reduced miR-16 levels compared to those from lungs not exposed to smoke and that HGF concentration in heavy smokers’ plasma correlates with levels of tobacco exposure. Finally, in vivo experiments confirmed that restoration of miR-16 expression in fibroblasts reduced their ability to promote tumor growth and that HGF plays a central role in the pro-tumorigenic activity of fibroblasts. Conclusions Overall, these results uncover a central role for miR-16 in regulating HGF production by lung fibroblasts, thus affecting their pro-tumorigenic potential. Correlation between smoking exposure and miR-16 levels could provide novel clues regarding the formation of a tumor-proficient milieu during the early phases of lung cancer development

Symptomatic mucocutaneous toxicity of hydroxyurea in Philadelphia chromosome-negative myeloproliferative neoplasms the mister hyde face of a safe drug

BACKGROUND: The current study was conducted to evaluate severe mucocutaneous toxicity during treatment with hydroxyurea (HU) in a large cohort of patients with Philadelphia chromosome-negative myeloproliferative neoplasms (MPN). METHODS: Among 993 consecutive patients newly diagnosed with MPN at 4 centers in Rome between January 1980 and December 2009, 614 patients (277 men and 337 women with a median age of 64.4 years [interquartile range (IR), 54.4 years-72.7 years]) received HU. HU was administered as first-line treatment in 523 patients (85.2%) and as ≥ second-line treatment in 91 patients (14.8%). RESULTS: Mucocutaneous toxicity was reported in 51 patients (8.3%) after a median period from the initiation of HU treatment of 32.1 months (IR, 10.5 months-74.6 months) and a mean HU dose of 1085 mg (± 390 mg); 30 patients (58.8%) developed a painful ulcerative skin toxicity, mainly located in the perimalleolar area; 11 patients (21.6%) had oral aphthous ulcers; and 10 patients (19.6%) developed a nonulcerative skin toxicity with erythema and skin infiltration. After the mucocutaneous toxicity occurred, HU treatment was continued at the same dose in 5 patients (9.8%), reduced in 12 patients (23.5%), and temporarily discontinued in 7 patients (13.7%); the remaining 27 patients (52.9%) required a permanent drug discontinuation. After a median period of 4.3 months (IR, 2.4 months-9.0 months) from the onset of the skin toxicity, 39 patients (76.5%) had a complete resolution and 12 patients (23.5%) had improvement without complete resolution. CONCLUSIONS: Mucocutaneous toxicity during HU treatment is more common than expected and may present with different clinical features. Moreover, it often requires a permanent drug discontinuation and only a partial resolution is reported to occur in approximately 25% of patients. © 2011 American Cancer Society

Anagrelide in Essential Thrombocythemia (ET): Results from 150 patients over 25 years by the “Ph1‐negative Myeloproliferative Neoplasms Latium Group”

Background and aims: Anagrelide is a drug effective in reducing platelet counts in essential thrombocythemia (ET) and Ph1-negative myeloproliferative neoplasms. The aim of this study was to evaluate the real-life use of anagrelide in patients with ET followed over 25 years at the Haematological Institutes belonging to “Ph1-negative Myeloproliferative Neoplasms Latium Group.”. Patients and methods: Eligibility criteria were diagnosis of ET and treatment with anagrelide. Data were collected through an ad hoc case report form. Results: One hundred and fifty patients received anagrelide for a median time of 7.4 years (0.1-23.2). Anagrelide was administered as first-line therapy in 34.7% of patients, as second-line in 52% and as third-line in 13.3%: 85.4% responded to therapy. Sixty-eight/136 evaluable patients reported side effects: palpitations, peripheral vasodilation, anaemia, diarrhoea and gastric distress. Fourteen thrombotic (arterial 10, venous 4) and 51 bleeding events (minor 48, major 3) occurred. Sixteen/150 (10.6%) patients developed secondary myelofibrosis and 3/150 (2%) an acute myeloid leukaemia. Conclusions: In our experience, anagrelide is an effective drug in reducing platelet levels in a high percentage of patients with ET. It is especially addressed to younger people. A careful assessment of the thrombotic risk and monitoring of cardiac function, at diagnosis and during follow-up, is mandatory

Additional file 1: of MiR-16 regulates the pro-tumorigenic potential of lung fibroblasts through the inhibition of HGF production in an FGFR-1- and MEK1-dependent manner

Figure S1. In vitro characterization of the immortalized CAF154 fibroblasts. The constitutive high levels of hTERT in all the fibroblasts transduced with retroviral particles (examples shown in A) were confirmed. Nevertheless, almost all the fibroblasts stopped growing after a few population doublings (PDs) and underwent senescence (B) with the exception of CAF154-hTERT cells, which expressed high levels of hTERT (A), showed no signs of senescence (B), and proliferated in a continuous fashion in vitro (C). Cumulative PDs were calculated at the end of every passage in relation to the cell number at the first passage. Of note, despite the immortalization process, CAF154-hTERT maintained the capacity to promote the growth of the adjacent cancer cells in co-culture experiments (D). (TIFF 422 kb

Thrombosis and survival in essential thrombocythemia: A regional study of 1,144 patients

To identify prognostic factors affecting thrombosis-free survival (TFS) and overall survival (OS), we report the experience of a Regional cooperative group in a real-life cohort of 1,144 patients with essential thrombocythemia (ET) diagnosed from January 1979 to December 2010. There were 107 thrombotic events (9.4%) during follow-up [60 (5.3%) arterial and 47 (4.1%) venous thromboses]. At univariate analysis, risk factors for a shorter TFS were: age >60 years (P 60 years (P 15 × 10(9) /l (P = 0.0370) were independent risk factors. Previous thrombotic events in ET patients are crucial for TFS but their importance seems related not to the occurrence per se but mainly to the interval between the event and the diagnosisTo identify prognostic factors affecting thrombosis-free survival (TFS) and overall survival (OS), we report the experience of a Regional cooperative group in a real-life cohort of 1,144 patients with essential thrombocythemia (ET) diagnosed from January 1979 to December 2010. There were 107 thrombotic events (9.4%) during follow-up [60 (5.3%) arterial and 47 (4.1%) venous thromboses]. At univariate analysis, risk factors for a shorter TFS were: age >60 years (P < 0.0054, 95% CI 1.18-2.6), previous thrombosis (P < 0.0001, 95% CI 1.58-4.52) and the presence of at least one cardiovascular risk factor (P = 0.036, 95% CI 1.15-3.13). Patients with a previous thrombosis occurred ≥24 months before ET diagnosis had a shorter TFS compared to patients with a previous thrombosis occurred <24 months (P = 0.0029, 95% CI 1.5-6.1); furthermore, patients with previous thrombosis occurred <24 months did not show a shorter TFS compared with patients without previous thrombosis (P = 0.303, 95% CI 0.64-3