Influence of static compression on mechanical parameters of acoustic foams

The modification of elastic properties of compressed acoustic foams is investigated. The porous sample is first submitted to a static compression and then to a dynamic excitation of smaller amplitude, corresponding to acoustical applications. The static compression induces the modification of the dynamic elastic parameters of the material. This work focuses on Young's modulus. The variation is measured with two different experimental methods: The classical rigidimeter and an absorption measurement. The effective Young's modulus is directly measured with the first method and is indirectly determined through the quarter-wave length resonance of the frame with the second one. The results of the two measurements are compared and give similar tendencies. The variation of the dynamic Young's modulus as a function of the degree of compression of the sample is shown to be separated in several zones. In the zones associated with weak compression (those usually zones encountered in practice), the variation of the effective Young's modulus can be approximated by a simple affine function. The results are compared for different foams. A simple model of the dependency of the Young's modulus with respect to the static degree of compression is finally proposed for weak compressions.

[Intracranial ependymomas: retrospective study of 16 cases]

PURPOSE

To report the epidemiological, clinical aspects and therapeutic results of intracranial ependymomas in Morocco.

PATIENTS AND METHODS

Our retrospective study concerned 16 cases of intracranial ependymomas, treated from January 1995 to December 2002 at the radiotherapy department of Ibn Rochd Hospital of Casablanca, Morocco.

RESULTS

The average age was 15 years and complete surgery was possible in two cases. All the patients received cranial radiotherapy, combined with chemotherapy in six cases. Overall survival and progression-free survival at 5 years were respectively 50% and 31%. Eleven patients had local recurrence after an average period of 21 months. Progression-free survival at 5 years was better if complete resection: 100% vs. 28.6% in cases of incomplete resection, and depending on the histological type with 50% for classic ependymomas and 16.6% for anaplastic.

CONCLUSION

Ependymomas are rare tumors and complete resection is the standard treatment followed by postoperative radiotherapy. The place of chemotherapy remains to be defined.

Cancer du sein: l’homme est aussi concerné. Étude de 21 cas

Introduction

Le cancer du sein, première pathologie maligne chez la femme, reste une maladie rare chez l’homme. Il représente environ 1 % des cancers du sein et moins de 1 % de l’ensemble des néoplasies masculines. L’objectif de cette étude est d’analyser les caractéristiques cliniques, histologiques et thérapeutiques du cancer du sein chez l’homme.

Patients et méthodes

Les auteurs présentent une étude descriptive menée de manière rétrospective au service de radiothérapie-oncologie du CHU Ibn-Rochd de Casablanca, entre janvier 2006 et décembre 2007, concernant une série de 21 patients de sexe masculin présentant un cancer du sein.

Résultats

L’âge médian était de 70 ans (extrêmes: 39–84). Le délai médian de consultation était de huit mois (extrêmes: 2–24). Il s’agissait, dans 16 cas, d’une tumeur rétroaréolaire dont la taille médiane était de 35 mm (extrêmes: 15–80). Les tumeurs étaient classées T2 dans 12 cas et T4 dans sept cas. Le type histologique le plus représenté était le carcinome canalaire infiltrant (CCI) [18 cas]. Le grade SBR II a été retrouvé dans 13 cas. Le taux d’envahissement ganglionnaire axillaire prouvé histologiquement était de 38 % (huit patients) et dans 14 % des cas plus de trois ganglions étaient envahis. L’effraction capsulaire n’a été retrouvée que dans quatre cas. Les récepteurs hormonaux étaient positifs dans 19 cas. La prise en charge thérapeutique a consisté en une chirurgie radicale dans 14 cas avec une chimiothérapie associée à une radiothérapie dans cinq cas, 66 % des patients ont reçu une hormonothérapie. Après un suivi moyen de 23 mois, trois malades ont développé des métastases et six malades sont encore vivants sans maladie.

Conclusion

Le cancer du sein chez l’homme est rare. Son diagnostic se fait souvent à un stade tardif. Son traitement est similaire à celui de la femme avec un retard diagnostique retentissant sur le pronostic.

[A rare tumor of the infratemporal fossa]

INTRODUCTION

Giant cell tumors of bone (GCT) are usually benign and relatively rare. They have an aggressive behavior and an unpredictable prognosis. They occur mainly in the young adult, with a preferential localization in long bones. We report a giant cell infratemporal fossa tumor.

OBSERVATION

A 55-year-old female patient consulted for swelling in the right cheek. Surgical excision was incomplete because of the subtemporal tumor localization. Histological assessment proved a GCT. Forty-five grays postoperative external radiotherapy was applied to the surgical site. The patient had local control at the 12-month follow-up.

DISCUSSION

GCTs are seldom observed in the facial skeleton (2%). The recommended treatment is surgery. Radiotherapy can be indicated in case of incomplete or impossible surgical excision, or when surgery would be responsible for a major functional deficit.

[Ocular metastasis heralding gastric adenocarcinoma]

Ocular metastasis is a rare presenting feature of gastric adenocarcinoma. We report a 48-year-old woman who presented with a decrease in visual acuity of the right eye leading to the discovery of an ocular metastasis. Diagnostic work-up identified a gastric adenocarcinoma with pulmonary metastases. She received four cycles of chemotherapy combining epirubicin, cisplatin and fluorouracil. The patient died 6 months after the diagnosis of respiratory failure.

[Neuroendocrine carcinoma with large cells of the breast: case report and review of the literature]

Neuroendocrine carcinoma with large cells is a slightly different tumor from the high rank of malignity. We report a case of breast localization in a 28-year-old patient. It is a locally advanced classified T4dN1M0 tumor that required neoadjuvant chemotherapy. The clinical answer was 75% of the level of the tumor. A standard surgery mastectomy with axillary lymph node dissection was realized, followed by external radiotherapy. The anatomopathologic and the immuno-histochemical study of the operational part confirmed the diagnosis of neuroendocrine carcinoma with large cells expressing the progesterone receptor. The patient is subjected to adjuvant hormonal treatment. After a 12 months retreat, a complete remission is maintained. Considering the scarcity of neuroendocrine carcinoma with large cells of the breast, the therapeutic standard is not yet available and the forecast remains difficult to determine.

[Giant-cell bone tumors of the spine: report of two cases and literature review]

Giant cell tumours (GCT) are relatively rare neoplasms, most often benign. They are characterized by their local aggression. We report two observations of GCT, the spine in a 51-year-old woman and a 14-year-old boy. They were revealed by spinal pain and cord compression for the second observation. Computed tomography and magnetic resonance imaging showed osteolysis of the body and vertebral arch of L5 for the first and a process affecting the vertebral body and medullary canal of T6-T7 with spinal cord compression for the second case. The diagnosis was confirmed by histological examination in two cases. An external radiation at a dose of 45 Gy on L4, L5 and the sacrum was made in the first case and the dose of 40 Gy on the vertebrae of T4 to T9 and an additional 6 Gy on T5-T8 in the second case. The patients are alive without progress with five years and 18 months follow-up, respectively. Radiation could be proposed as a standard treatment for patients with incomplete excision or where surgery would induces functional deficits.