416 research outputs found
Inducible nitric oxide synthase expression in laryngeal neoplasia: correlation with angiogenesis
No full textHead Neck. 2002 Jan;24(1):16-23.
Inducible nitric oxide synthase expression in laryngeal neoplasia: correlation with angiogenesis.
Franchi A, Gallo O, Paglierani M, Sardi I, Magnelli L, Masini E, Santucci M.
Source
Department of Human Pathology and Oncology, University of Florence, Viale G. B. Morgagni 85, 50134 Florence, Italy. [email protected]
Abstract
BACKGROUND:
The nitric oxide (NO) pathway plays a relevant role in angiogenesis and tumor progression in squamous cell carcinoma (SCC) of the head and neck. The aim of this study was to assess whether the NO pathway may be correlated with angiogenesis in the transition from laryngeal dysplasia to invasive carcinoma.
METHODS:
We investigated the expression of the inducible NO synthase (iNOS) in 26 laryngeal precancerous lesions and 35 squamous cell carcinomas with respect to microvessel density. In addition, we determined iNOS activity and cGMP levels in specimens from SCCs.
RESULTS:
There was a significant increase of iNOS levels detected immunohistochemically passing from hyperplastic/mild dysplastic to moderate/severe dysplastic lesions to SCC (p =.04). Accordingly, Northern and Western analyses demonstrated higher iNOS mRNA and protein levels in SCCs than dysplastic mucosa. iNOS expression was significantly correlated with microvessel counts both in the group of preneoplastic lesions (p =.02) and in the group of SCCs (p =.01). In addition, iNOS activity was correlated with iNOS immunohistochemical expression (p =.1) and was significantly associated with increased vascularization (p =.03) in SCCs. Similarly, iNOS expression was significantly correlated with cGMP levels in SCC (p =.02) and increased tumor vascularization correlated with higher cGMP levels (rs =.4; p =.01).
CONCLUSIONS:
Our data indicate that the NO pathway may play a relevant role in the angiogenesis associated with the progression from laryngeal dysplasia to laryngeal SCC
Non solo Prisco di Panion: Fritz Bornmann, la storiografia tardoantica e le raccolte bizantine
No full textL’articolo sviluppa il contributo della giornata di studi in memoria di Fritz Bornmann a venti anni dalla sua morte (Università di Firenze, 2017). Vi si riprendono e valorizzano i risultati dell’edizione di Prisco di Panion che Fritz Bornmann pubblicò nel 1979, per poi ripercorrere i passi e le metodologie che hanno portato l’autrice alla nuova edizione critica nel 2008. Infine si evidenziano le piste di ricerca aperte da Bornmann riguardo ai cosiddetti Excerpta Historica Constantiniana, che godono di un rinnovato interesse presso gli studiosi contemporanei (si vedano i contributi di Andras Neméth, Paolo Odorico, Dariya Rafiyenko, Emerance Delacenserie, Peter van Nuffelen, Paul Magdalino, Anthony Kaldellis, Francesco Monticini, Lorenzo Maria Ciolfi e molti altri).At the University of Florence in 2017 was held a memorial workshop for Fritz Bornmann, after 20 years since his death. The present article sheds light onto the critical edition with Italian translation of the Byzantine historian Priscus of Panion, which Fritz Bornmann published in 1979. Priscus wrote in 5th century AD and his fragmentary work is preserved mostly in the Byzantine collection of the so-called Excerpta Historica Constantiniana. After Bornmann’s edition, research was developed by the author up to the new critical edition in 2008 for the Bibliotheca Teubneriana. Bornmann had long indicated the need of such a publication, along with the methodology to achieve new results. His contribution from the 1970s deserves to be widely known to the scholarly community interested in the revival about the Excerpta Historica Constantiniana: Andras Neméth, Paolo Odorico, Dariya Rafiyenko, Emerance Delacenserie, Peter van Nuffelen, Paul Magdalino, Anthony Kaldellis, Francesco Monticini, Lorenzo Maria Ciolfi and many others)
Shear bond strength of veneering porcelain to zirconia after argon plasma treatment
No full textPurpose: The aim of this study was to investigate if argon plasma cleaning increases the shear bond strength between zirconia and veneering ceramic surfaces.
Materials and methods: Ninety tablets of densely sintered yttriastabilized tetragonal zirconia polycrystal were divided into three groups according to cleaning treatment (steam cleaning or plasma of Argon for 375 or 750 seconds). Groups were divided into two subgroups according to the application of a ceramic liner (A = liner, B = no liner).
Results: Within subgroup A, argon plasma cleaning significantly decreased shear bond strength. In subgroup B, the plasma treatment increased the shear bond strength, but the differences were not statistically significant. Subgroup A demonstrated lower shear bond strength compared to subgroup B.
Conclusions: Argon plasma cleaning was suggested to improve the bond between ceramic and zirconia surfaces; however, when plasma cleaning was followed by a glassy liner application, the veneering ceramic/zirconia bond was significantly reduced
Shear bond strength of veneering porcelain to zirconia after argon plasma treatment.
No full textPURPOSE:
The aim of this study was to investigate if argon plasma cleaning increases the shear bond strength between zirconia and veneering ceramic surfaces.
MATERIALS AND METHODS:
Ninety tablets of densely sintered yttriastabilized tetragonal zirconia polycrystal were divided into three groups according to cleaning treatment (steam cleaning or plasma of Argon for 375 or 750 seconds). Groups were divided into two subgroups according to the application of a ceramic liner (A = liner, B = no liner).
RESULTS:
Within subgroup A, argon plasma cleaning significantly decreased shear bond strength. In subgroup B, the plasma treatment increased the shear bond strength, but the differences were not statistically significant. Subgroup A demonstrated lower shear bond strength compared to subgroup B
Ligand-independent tyrosine kinase signalling in RTH 149 trout hepatoma cells: comparison among heavy metals and pro-oxidants
No full textTyrosine phosphorylation depends on the activity of receptor and non-receptor tyrosine kinases and promote cell growth, differentiation and apoptosis. Different stressors are known to stimulate tyrosine kinase activities and this could explain a wide spectrum of effects that these agents produce on different organisms. We studied the effects of heavy metals and pro-oxidants on tyrosine kinase signalling in trout hepatoma cells (RTH 149) by Western immunoblotting. Use of antiphosphotyrosine showed that Hg(2+) and Cu(2+)in the microM range, and H(2)O(2) in the mM range, induced tyrosine phosphorylation. The effect of Cu(2+)was prevented by pre-incubation with genistein, while those of Hg(2+)and H(2)O(2) were only decreased, probably due to tyrosine kinase stimulation coupled to phosphatase inhibition. Phosphospecific antibodies against the three types of MAPKs showed that ERK is activated by heavy metals only, while p38 and SAPK/JNK are activated by H(2)O(2), Hg(2+), and Cu(2+) plus low H(2)O(2). Cell pre-incubation with p38 inhibitors indicated that ERK activation by H(2)O(2) is prevented by concomitant activation of p38. Phosphospecific STAT antibodies revealed activation by H(2)O(2) only. In conclusion, fish cell exposure to heavy metals and pro-oxidants produce specific tyrosine kinase responses, involving cross talk and redox modulatory effects
Epigallocatechin-3-gallate induces mesothelioma cell death via H2O2-dependent T-type Ca2+ channel opening
No full textMalignant mesothelioma (MMe) is a highly aggressive, lethal tumour requiring the development of more effective therapies. The green tea polyphenol epigallocathechin-3-gallate (EGCG) inhibits the growth of many types of cancer cells. We found that EGCG is selectively cytotoxic to MMe cells with respect to normal mesothelial cells. MMe cell viability was inhibited by predominant induction of apoptosis at lower doses and necrosis at higher doses. EGCG elicited H2O2 release in cell cultures, and exogenous catalase (CAT) abrogated EGCG-induced cytotoxicity, apoptosis and necrosis. Confocal imaging of fluo 3-loaded, EGCG-exposed MMe cells showed significant [Ca2+]i rise, prevented by CAT, dithiothreitol or the T-type Ca2+ channel blockers mibefradil and NiCl2. Cell loading with dihydrorhodamine 123 revealed EGCG-induced ROS production, prevented by CAT, mibefradil or the Ca2+ chelator BAPTA-AM. Direct exposure of cells to H2O2 produced similar effects on Ca2+ and ROS, and these effects were prevented by the same inhibitors. Sensitivity of REN cells to EGCG was correlated with higher expression of Cav3.2 T-type Ca2+ channels in these cells, compared to normal mesothelium. Also, Cav3.2 siRNA on MMe cells reduced in vitro EGCG cytotoxicity and abated apoptosis and necrosis. Intriguingly, Cav3.2 expression was observed in malignant pleural mesothelioma biopsies from patients, but not in normal pleura. In conclusion, data showed the expression of T-type Ca2+ channels in MMe tissue and their role in EGCG selective cytotoxicity to MMe cells, suggesting the possible use of these channels as a novel MMe pharmacological target
Nota sobre el corpus elegíaco helenístico: Fanocles
No full textThe passage of Ps.-Prob., in Verg. B. 2.23 could be an indirect transmitted testimony of
the work of Alexander Aetolus (frg. 21 Magnelli) and Phanocles. This critical note provides
new arguments in favour of this authorship, which, in the case of Phanocles, would entail
a significant contribution to a relatively exiguous corpus.El pasaje de Ps.-Prob., in Verg. B. 2.23 podría constituir un testimonio de transmisión indirecta de la obra de Alejandro de Etolia (frg. 21 Magnelli) y de Fanocles. En esta nota crítica
se aportan nuevos argumentos a favor de esta autoría, lo que, en el caso de Fanocles supondría
una importante aportación a un corpus relativamente exiguo
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