Expression pattern of ISL-1, TTF-1 and PAX5 in olfactory neuroblastoma.

Olfactory neuroblastoma (ONB) is a rare neoplasm of the sinonasal area with neuroendocrine differentiation. ISL-1, TTF-1 and PAX5 are transcription factors that are frequently upregulated in tumors showing neuroendocrine differentiation. The aim of our study was to evaluate these markers in a group of ONBs. We included 11 ONBs from 4 large university hospitals. Immunohistochemical expression of TTF-1, PAX5 and ISL-1 was evaluated. TTF-1, ISL-1 and PAX5 were expressed in 3/11 cases (27.27%, h-score: 3-45), 7/11 cases (63.64%, h-score: 23-200), and in 3/11 cases (27.77%, h-score 3-85), respectively. The patient with the strongest PAX5 reactivity exhibited an aggressive clinical course with rapid dissemination to the spine and death shortly after the diagnosis. No significant correlation in the expression of PAX5 and TTF-1 ( = 0.43; p = 0.18) was observed. ISL-1 is widely expressed in tumors with neuroendocrine differentiation and therefore of limited value in their differential diagnosis. TTF-1 positivity does not exclude the diagnosis of primary ONB, although usually only a small percentage of cells are positive. PAX5 expression is infrequent (27.27%) in ONB; however, if present it can be associated with a very aggressive clinical course.

The pneumatisation of anterior clinoid process is not associated with any predictors that might be recognised preoperatively.

The anterior clinoid process (ACP) is usually removed during surgeries of proximal internal carotid artery (ICA) aneurysms. However, some ACPs present with air cells originating from the sphenoid or/and ethmoid sinus. In surgeries containing a clinoidectomy of a pneumatised process, up to 40% of patients experience cerebrospinal fluid (CSF) rhinorrhoea. The aim of this study was to explore the potential predictors of pneumatisation of the ACP, as well as to compare the occurrence of CSF rhinorrhoea between total and partial anterior clinoidectomies. This study comprised 2 different groups, with 2 different analyses. Firstly, the pneumatisation of the ACP was evaluated in 496 ACPs and was based on 248 computer tomography exams (CT). The c2 test and ROC curve comparisons were utilised in conjunction, to explore possible predictors of air cell accumulation in the ACP. The overall pneumatisation rate was 9.7%, unilateral and bilateral aerial ACP was found in 4.4% and 2.6% of all patients respectively, while at least one pneumatised ACP was found in 14.1% of examined patients. The route of pneumatisation was established in 87.5% of cases. The side of the ACP, gender, and patient age were not significantly associated with both pneumatisation of ACP or route of pneumatisation.Secondly, a clinical group of 23 patients after operative securing of an ICA aneurysm were retrospectively assessed with regards to the extent of anterior clinoidectomy and the occurrence of CSF rhinorrhoea. A total of 23 ACPs were removed, 17 ACPs were totally resected, and 6 underwent partial resection. CSF rhinorrhoea was not noted in any patients, thus the comparison between clinical groups was not valid. Moreover, we described a novel method of partial removal of the lateral aspect of ACP, which was applied in 6 patients treated for an ICA - ophthalmic artery junction aneurysm.

Biomechanics of the pulmonary autograft valve in the aortic position.

Pulmonary autograft valve replacement has been simulated by implanting the pulmonary valve into the aortic position of the same cadaver heart from both human and porcine sources. The forces acting on the pulmonary valve leaflets have been calculated on the basis of a triaxial ellipsoid mathematical model. These forces on the pulmonary autograft valve were shown to be essentially similar to those previously reported for aortic valve leaflets. Biomechanical measurements have been made on the simulated autograft valves and on the isolated pulmonary valve cusps. The tensile strengths of the pulmonary valve cusps in both circumferential and radial directions were roughly three times greater than those of aortic valve cusps. This indicated the ability of the pulmonary valves to accept, ab initio, aortic valve closing pressures. Pressure-induced changes in dimension, calculated on the basis of diameters of the simulated pulmonary autograft root, also indicated that the distensibility of the autograft valve was limited. It reached a maximum at 30 mm Hg (4 kPa) without any suggestion of further distension to the point of distortion and incompetence. The combination of the calculated forces acting on the valve and the biomechanical measurements have shown that pulmonary valves used as autograft aortic valve replacements are able to tolerate aortic pressures from the time of implantation. These experimental results from simulated autografts support the clinical use of this valve over the past 13 years.