Rossella Veronica Barberis

In this paper, we report on the use of a purpose-built hybrid solid-state microwave and radiofrequency generator operating at frequencies of 2.45 GHz and/or 480 kHz for cancer ablation in various tissues. The hybrid generator was tested ex vivo on chicken breast and bovine liver and has demonstrated that the high accuracy of the power delivered to the sample can be achieved by controlling the emitted power versus the temperature profile of the treated sample. In particular, the hybrid generator incorporates control systems based on impedance or reflected power measurements that allow controlled ablation without causing unwanted carbonization and without including areas where tissue damage is not desired. The results of the ex vivo tests showed that radiofrequency ablation (RFA) could be effective for performing controlled ablations with minimally invasive probes, such as cardiac pathologies, small lesions, and tissues with particular composition, while microwave ablation (MWA) could be optimal for performing large ablations in highly vascularized tissues, such as liver cancer, where it is necessary to achieve higher temperatures.

In this paper we report on the use of an in-house developed solid-state hybrid microwave and radiofrequency generator operating at frequencies of 2.45 GHz and/or 480 kHz for cancer ablation in various tissues. The generator has demonstrated increased accuracy due to its custom-designed hardware, which incorporates the latest technologies and algorithms to control the emitted power versus temperature profile of the treated sample. In particular, the hybrid generator incorporates control systems based on impedance or reflected power measurements that allow controlled ablation without causing unwanted carbonisation and without including areas where tissue damage is not desired. Tests performed ex-vivo on chicken breast and bovine liver show that radiofrequency ablation (RFA) is very effective for performing controlled ablations with minimally invasive probes, such as cardiac pathologies, small lesions, tissues with particular composition, while microwave ablation (MWA) is optimal for performing large ablations in highly vascularised tissues, such as liver cancer, where it is necessary to achieve higher temperatures.

Myxomatous mitral valve degeneration (MMVD) is the most common acquired cardiac disease in canine species, and valvular interstitial cells (VICs) are considered the main responsible for the development of this pathology. The scientific interest is focused on isolating and characterizing these cells. The aims of the present study were to verify a novel VICs mechanical isolation method and to characterize isolated cells using immunocytochemistry and immunofluorescence, with parallel histological and immunohistochemistry assays on bovine and canine healthy and MMVD mitral valves. Antibodies against vimentin (VIM), smooth muscle actin (SMA), von Willebrand (vW) factor, Transforming Growth Factor (TGF) β1, and Transient Receptor Potential Vanilloid 1 (TRPV1) were used. The isolation method was considered reliable and able to isolate only VICs. The different assays demonstrated a different expression of SMA in healthy and MMVD mitral valves, and TRPV1 was isolated for the first time from bovine and canine VICs and the correspondent mitral valve leaflets. The novelties of the present study are the new isolation method, that may allow correlations between laboratory and clinical conditions, and the identification of TRPV1, which will lead to further investigations to understand its function and possible role in the etiology of MMVD and to the design of new therapeutic strategies.