Anti-biofilm activity of pseudoalteromonas haloplanktis tac125 against staphylococcus epidermidis biofilm: Evidence of a signal molecule involvement?

Staphylococcus epidermidis is recognized as cause of biofilm-associated infections and interest in the development of new approaches for S. epidermidis biofilm treatment has increased. In a previous paper we reported that the supernatant of Antarctic bacterium Pseudoalteromonas haloplanktis TAC125 presents an anti-biofilm activity against S. epidermidis and preliminary physico-chemical characterization of the supernatant suggested that this activity is due to a polysaccharide. In this work we further investigated the chemical nature of the anti-biofilm P. haloplanktis TAC125 molecule. The production of the molecule was evaluated in different conditions, and reported data demonstrated that it is produced in all P. haloplanktis TAC125 biofilm growth stages, also in minimal medium and at different temperatures. By using a surface coating assay, the surfactant nature of the anti-biofilm compound was excluded. Moreover, a purification procedure was set up and the analysis of an enriched fraction demonstrated that the anti-biofilm activity is not due to a polysaccharide molecule but that it is due to small hydrophobic molecules that likely work as signal. The enriched fraction was also used to evaluate the effect on S. epidermidis biofilm formation in dynamic condition by BioFlux system.

Fabrication, characterization and cell cultures on a novel composite chitosan-nano-hydroxyapatite scaffold.

This paper deals with the characterizations made during the development of a nano-HAp loaded chitosan scaffold, obtained by the freeze-drying technique combined with a novel in situ crystal growth method. The nano-composites were characterized by a highly porous and interconnected structure. The XRD patterns and calculated domain sizes of the HAp nano-crystals nucleated on the chitosan scaffolds are very similar to the ones recorded for deproteinated bone apatite. Both osteoblasts (MG63) and mesenchimal cells (hMSC) were showing good proliferation and adhesion onto the scaffolds. The presence of extensive filopodia and excellent spreading in and around the interconnected porous structure, indicated a strong cellular adhesion and growth. Moreover a good hMSC osteogenic differentiation has been verified. The observations related to well-developed structure morphology, physicochemical properties and high cytocompatibility suggest that the obtained chitosan-nHA porous scaffolds are potential candidate materials for bone regeneration.

Pentadecanoic acid against Candida albicans-Klebsiella pneumoniae biofilm: towards the development of an anti-biofilm coating to prevent polymicrobial infections.

The ability to form biofilms is a common feature of microorganisms, which can colonize a variety of surfaces, such as host tissues and medical devices, resulting in infections highly resistant to conventional drugs. This aspect is particularly critical in polymicrobial biofilms involving both fungi and bacteria, therefore, to eradicate such severe infections, new and effective anti-biofilm strategies are needed. The efficacy of pentadecanal and pentadecanoic acid as anti-biofilm agents has been recently reported against different bacterial strains. Their chemical similarity with diffusible signal factors (DSFs), plus the already known ability of fatty acids to act as anti-biofilm agents, suggested to explore their use against Candida albicans and Klebsiella pneumoniae mixed biofilm. In this work, we demonstrated the ability of both molecules to prevent the formation and destabilize the structure of the dual-species biofilm. Moreover, the pentadecanoic acid anti-biofilm coating, previously developed through the adsorption of the fatty acid on polydimethylsiloxane (PDMS), was proved to prevent the polymicrobial biofilm formation in dynamic conditions by confocal laser scanning microscopy analysis. Finally, the evaluation of the expression levels of some biofilm-related genes of C. albicans and K. pneumoniae treated with pentadecanoic acid provided some insights into the molecular mechanisms underpinning its anti-biofilm effect.

[Echo-Doppler evaluation of the renal arterial flow in hepatic cirrhosis]. / Valutazione mediante eco-Doppler del flusso arteriolare renale in corso di cirrosi epatica.

In liver cirrhosis the sodium retention depends on a decreased renal perfusion by arteriolar vasoconstriction. To evaluate the usefulness of echo-Doppler in detecting such hemodynamic impairment, we studied 16 cirrhotic patients and 16 healthy subjects as control group. We measured Pulsatility Index (P.I.) and Resistivity Index (R.I.). Both parameters resulted to be statistically higher in cirrhotic patients than in controls; moreover they resulted to be higher in cirrhotics with ascites than in those without. Therefore echo-Doppler can detect intraparenchymal renal vasoconstriction in cirrhosis, this impaired perfusion is already evident before ascites formation.

[Urethral echography: potential and limitations]. / L'ecografia uretrale: possibilità e limiti.

Since in the early years of 1980, the diagnostic for images about male's urethral injury was exclusively assigned to urethrocystography. Sially in repeated check the gonads too often are exposed to ionizing radiations. Our results show urethrocystography/ultrasonography good correlation (13/15) cases) with 86% sensibility. Even if the urethrocystography is a methodic of first instance, the urethral ultrasonography is efficacious in follow up of urethral injury, particularly in the study of anterior urethra.

[Echographic characteristics of calcifying fibrous pseudotumor of the epididymis]. / Aspetti ecografici dello pseudotumore fibroso calcificante dell'epididimo.

Calcifying fibrous pseudotumor of epididymis is a rare neoplasia. The A.A. report echographical aspects about two clinical acses examined in 1993. Peculiar aspects of tumour are characterized by acoustic obstruction of the fibrous tissue and contextual iperechogenic spots, so to stimulate a calcific pseudocapsula. The A.A. revalue the echographical images after surgical exploration and discuss about differential diagnosis with TBC.

[Stress urinary incontinence in women: magnetic resonance assessment]. / Incontinenza urinaria da sforzo della donna. Valutazione mediante Risonanza Magnetica.

The preoperative radiologic study of female stress urinary incontinence is still incomplete and often not well tolerated. MRI is becoming a major diagnostic tool for pelvis assessment also thanks to its allowing dynamic studies. Therefore, MRI was used for the static and dynamic assessment of the pelvic floor, which is compromised in stress incontinence, in a series of 21 patients. Dynamic studies were reliable in all but two cases. Our MRI technique demonstrated anatomical and functional stress urinary incontinence alterations, such as the increased distance between urethra and pubic symphysis (16 patients), vaginal changes (7 patients), levator ani muscle changes (9 patients) and urethropelvic ligaments changes (9 patients). The functional changes caused by pelvic floor collapse were observed in all the patients with reliable dynamic studies, i.e., the posterior urethrovesical angle was increased and the pelvic floor excessively lowered during pelvic strain. Our preliminary results suggest that MRI can play a major role in the preoperative assessment of stress urinary incontinence, notwithstanding the fact that the exam is performed with the patient supine and therefore with no gravity.

[Diagnostic yield in rhino-sinusal inflammatory pathology: comparison of projective radiology, CT and MR]. / Resa diagnostica nella patologia flogistica rino-sinusale: confronto tra radiologia proiettiva, TC e RM.

In everyday practice, the radiologist is concerned with the diagnosis of inflammatory conditions of the nose and paranasal sinuses. This paper was aimed at evaluating and comparing the diagnostic efficacy of the main diagnostic imaging procedures currently available. Fifty-six patients were studied: 25 with computed radiography (CR) and CT, 21 with CR and MRI (0.22 T resistive magnet), and 10 with CR, CT, and MRI. From the diagnostic point of view, the conventional-like CR image was assumed as analog to the conventional radiographic (RX) one on the basis of previous personal experience. The following elements were separately considered for RX, CR, CT, and MRI: anatomical structure identificability, spatial resolution, dosimetry, time consumption, diagnostic results, and economics. A global performance index was calculated (RX less than 1; CR = 1; MRI ranging 1.2-2.2; CT = 7.3). CR was superior to RX, from both a diagnostic and a dosimetric point of view, but buying the equipment is nowadays expensive. CT and MRI were superior to both RX and CR in the diagnosis of inflammatory conditions of the nose and paranasal sinuses. When an inflammatory condition is unquestionable, MRI is more accurate than CT, but the latter (thanks to its optimal documentation of both bony walls and soft tissues) is superior to MRI in the differential diagnosis of a generic disease of the nose and paranasal sinuses--that is, when the inflammatory nature is questionable. MRI limitations were poor visualization of bone walls, high cost, and poor access. Thus, CT emerged as the technique of choice, thanks to its diagnostic results, easy access and low cost, with a negligible radiation dose to patients.