Sintering behavior of magnesium-substituted fluorapatite powders prepared by hydrothermal method.

Magnesium-substituted fluorapatite powders were synthesized by hydrothermal method, and their sintering behavior was investigated by dilatometry in the temperature range 25-1100°C. Analysis of the obtained powders by X-ray diffraction and (31)P NMR spectroscopy showed that the powders consisted of a single apatite phase and no amorphous phase has been formed. Compared to pure fluorapatite, the shrinkage of the substituted samples occurred in two steps and the temperature at which the sintering rate was maximum is lower. In addition, the shrinkage was interrupted by an expansion of the samples due to the formation of a liquid phase. The latter phase led to the crystallization of needle-crystals by a dissolution-diffusion-reprecipitation process.

[Carcinoid tumor of the larynx]. / Tumeur carcinoïde du larynx.

OBJECTIVE: Carcinoid tumors are among the exceptional neoplasms of the larynx. The literature is reviewed and the problems with diagnosis and management of this rare tumor are discussed. METHODS: The authors report a case of a carcinoid tumor of the larynx. RESULTS: This paper describes the case of a well-differentiated carcinoid tumor of the aryepiglottic fold in a 59-year-old woman who presented with hoarseness lasting eight months. After surgical excision, the patient developed recurrence of the disease 14 years later. CONCLUSION: Carcinoid tumors require accurate diagnosis because of their varied clinical behavior and prognosis. The typical carcinoid treatment of choice is conservative surgery.

Nasal NK/T-cell lymphoma in the paediatric population. Two case reports.

Nasal natural killer (NK)/T-cell lymphoma is an uncommon disease, and only a few paediatric cases are found in the literature. We report 2 cases of NK/T-cell lymphoma occurring in children. The primary site was the the nasal cavity in the first case (5-year-old girl) and the tonsil in the second case (4-year-old boy). Histological study showed a polymorphic neoplastic infiltrate with an angioinvasive pattern and T-cell phenotype. Ebstein-barr virus infection was established by in situ hybridization. Both underwent an aggressive chemotherapy regimen. The outcome was favorable for the 4-year old boy; however, the 5-year-old girl died two months after diagnosis.

[Bronchoscopic findings in children with prolonged respiratory symptoms]. / Indication de la bronchoscopie chez des enfants avec une symptomatologie respiratoire trainante traitement.

OBJECTIVE: This retrospective study aims to establish an algorithm indicating a bronchoscopy, based on clinical and radiological criteria predictive of the presence of a foreign body (FB), in children with prolonged respiratory symptoms and no history of foreign body aspiration (FBA); to establish a study of these criteria and to compare the clinical, radiological and broncoscopic findings in such cases. METHODS: We chose to review the records of 73 children (age < or = 15 years) with prolonged respiratory symptoms (for at least 15 days) and no history of FBA who underwent bronchoscopy at our institution between 1996 and 2005. RESULTS: The mean age was 3 years and 2 months, the majority of the patients were between 1 and 3 years of age (56%), 59% of the patients were boys and the mean of evolution of symptoms before the broncoscopy was 3 months and 3 weeks. We found a foreign body (FB) in 17 cases (23.2%). The FBs were in 88.2% of the cases of vegetable origin. A granulation tissue was associated in 47% of positive bronchoscopies. There were no complications related to bronchoscopy. The clinical and the radiological findings were no specific of FBs. CONCLUSION: Bronchoscopy must be indicated in suspected cases of FBA to prevent delayed diagnosis and pulmonary sequelae. The clinical and radiological findings may help the clinician to indicate it.

[Laryngeal cryptococcosis revealing AIDS: a case report]. / Cryptococcose laryngée révélatrice d'un SIDA: à propos d'une observation.

The cryptococcal infection of the larynx is uncommon. We present a case of a 65-year-old woman who was seen because of chronic hoarseness. Direct laryngoscopy revealed an infected lesion of the laryngeal vestibule. Histologic examination showed yeasts surrounding by capsules allowing a diagnosis of laryngeal infection by cryptococcus neoformans. The patient had also meningitis and pulmonary localisation. We have undergone a risk factors research and this results in finding out that HIV serology was positive. She received a treatment with amphotericin B followed by fluconazole during 6 months with complete recovery of her laryngeal infection. The patient died 11 months after the AIDS diagnostic.

[Solitary fibrous tumor of the nasal cavity: an observation report]. / Tumeur fibreuse solitaire de la fosse nasale: à propos d'une observation.

Solitary fibrous tumour is a rare mesenchymal tumour first described in the pleura, but can involve other serosal surfaces and viscera. In the nasal cavity, it is extremely rare. We report a new case in 90-year-old man and discuss the morphologic and evolutive features.

[Nasopharyngeal angiofibroma with intracranial extension: situating the chemotherapy-radiotherapy association]. / L'angiofibrome nasopharyngien avec extension intracrânienne : place de l'association chimiothérapie-radiothérapie.

Nasopharyngeal angiofibroma is a locally aggressive, although histologically benign, vascular neoplasm. This neoplasm accounts for 0.05% of head and neck tumours and affects almost exclusively male adolescents. Surgery is considered as the primary treatment of nasopharyngeal angiofibroma. Other treatment modalities such as radiotherapy and chemotherapy are still recommended for intracranial extension involving the cavernous sinus or the internal carotid artery. We report a rare case of nasopharyngeal angiofibroma, further complicated with a Kennedy syndrome in a 34 year-old women. The treatment consisted in a chemotherapy (adriamycine, decarbazine) followed by radiotherapy. We discuss the relevance and outcome of the association chemotherapy-radiotherapy in the treatment of nasopharyngeal angiofibromas with a consistent intracranial extension (stage III B of Arch Otolaryngol Head Neck Surg 122 (2003) 122-129).

[Extra-nodal T lymphomas of the nasal cavities and sinuses]. / Les lymphomes T des fosses nasales et des sinus.

INTRODUCTION: Extra-nodal T lymphomas of the ear, nose, and throat (ENT) are unusual in Western countries, with differential diagnosis from other destructive and necrotizing lesions of the sino-nasal tract often difficult. MATERIAL AND METHODS: Eleven cases of extra-nodal lymphomas of the upper aerodigestive tract tract managed in the ENT department of F. Hached hospital in Sousse, Tunisia, were retrieved over a 10-year period (1995-2004). The aim of our study was to report the clinical and pathological data and the outcome for each patient. RESULTS: The median age of patients was 41-years. The most frequent site of involvement was the nasal cavity. Clinically, the symptoms were not specific. Histological examination identified two cases of T/NK lymphoma and nine cases of T-lymphoma not otherwise specified. Immunohistochemistry and in situ hybridization techniques positively detected Epstein-Barr virus in tumoral cells, in seven cases. Tumor staging, in 10 patients, found distant metastasis in three. Nine patients underwent the following treatment: exclusive radiotherapy (one patient), radiochemotherapy (three patients), and exclusive polychemotherapy (five patients). The two remaining patients had no treatment because of a rapidly unfavorable progression. After a median follow-up of 11-months, clinical outcome consisted in death in seven patients and remission in three patients; one patient was lost of follow-up. CONCLUSION: Extra-nodal lymphomas of the ORL tract are rare in Tunisia. Clinical presentation is not specific, depending on the lymphoma location. Diagnosis relies on clinical presentation and immunophenotypic and molecular characteristics; morphological features are not specific. These are aggressive lymphomas, often requiring multidisciplinary management.

[Parotid retention cyst revealing a mucoepidermoid carcinoma]. / Kyste parotidien rétentionnel révélateur d'un carcinome mucoépidermoïde.

OBJECTIVES: To describe a case of mucoepidermoid carcinoma of the parotid gland that caused obstruction of a salivary gland duct and manifested as a parotid retention cyst. PATIENT AND METHODS: A 21-year-old woman presented with a 5-cm cystic swelling in her left parotid region. Ultrasound examination and a computerized tomography scan showed a clearly outlined parotid cyst. Through a conventional parotidectomy incision, the cyst was excised with parotid gland tissue around the lesion. The patient had an uncomplicated recovery. RESULTS: Histopathological examination of the resected parotidectomy material showed a parotid retention cyst and a mucoepidermoid carcinoma measuring 5mm in diameter. CONCLUSION: Among acquired cysts of the parotid gland, retention cysts are the most frequent. They may be the presenting symptom in patients with occult cancer of the parotid. In this case report, a mucoepidermoid carcinoma played a significant role in the obstruction of a salivary gland duct and caused a parotid retention cyst. Thus, a wide excision of the parotid retention cyst is necessary, as is a careful review of the histology searching for malignant lesion.

Aspergillus mastoiditis with intact tympanic membrane in immunocompetent host.

Aspergillus mastoiditis is a very rare condition usually observed in immunocompromised patients. Masked mastoiditis is defined as a subclinical infectious inflammatory process of the mucosal lining and bony structures of the mastoid air cells with intact tympanic membranes. To our knowledge, our report of a masked Aspergillus mastoiditis occurring in a 71-year-old diabetic woman is only the second case of masked mastoiditis in the literature. Aggressive medical and surgical management are necessary to avoid a fatal outcome from this invasive infection.

[NK/T-Cell lymphoma of nasopharynx]. / Lymphomes T/NK du nasopharynx.

OBJECTIVE: Discussion of the clinical and paraclinical features of a rare tumor in the nasopharynx, the NK/T-cell lymphoma, with an emphasis on the implications of Epstein Barr Virus (EBV) in its pathogenesis and prognosis. CASES REPORT: We report the cases of a woman and a man aged 34 and 48, respectively. Clinical presentation was non-specific and diagnosis was established with deep biopsies under general anesthesia. Immunochemistry and in situ hybridization were positive for Epstein Barr virus in tumor cells in both cases. The patients were first treated with chemotherapy (CHOP regimen), then underwent radiotherapy. The first patient achieved complete response at twenty months follow-up. The second patient presented two recurrences which were treated by chemotherapy. He died from acute renal failure during treatment of the second recurrence. CONCLUSION: Diagnosis of NK/T-cell lymphoma may be delayed in the event of non-specific symptoms. Deep biopsies outside necrotic tissue must be obtained. Search for EBV is important as its presence is a factor of poor prognosis.

Stability indicating LC method for the determination of pipamperone.

A high performance liquid chromatographic method for the determination of pipamperone in the presence of one related impurity and its degradation products is described. The method is based on the use of an amide functionalized bonded phase column (LC-ABZ+ Plus) and a mobile phase of acetonitrile-tetrahydrofuran-sodium phosphate monobasic (0.05 M, pH 6.5) (16:11:73, v/v/v). All peaks are eluted in <8 min. The method was demonstrated to be precise, accurate and specific. Degradation study showed that the drug is stable in acidic medium while it degrades under basic and oxidative conditions. The results indicated that the proposed method could be used in a stability assay.

[Mycobacterial cervical lymphadenitis: role of surgery]. / Adénopathies cervicales tuberculeuses: place de la chirurgie.

OBJECTIVE: To discuss the place of surgery in the management of mycobacterial cervical lymphadenitis. PATIENTS AND METHODS: It's a retrospective study (1982-2002) about 246 patients treated in the ENT department of Farhat Hached Sousse for cervical lymph node tuberculosis. Resolution was considered when neither symptoms nor lymphadenopathy in examination were noted. RESULTS: The mean age of our patients was 28 years. A light female prevalence was noted. In 5 patients diagnosis was established by lymph node punction. A medical treatment of first intention was then managed with a failure in 3 cases, after deadlines from 3 to 4 months. All other patients were operated: cellulolymphadenectomy (47%), adenectomy (47%) or drainage of a cervical abscess (4%). Recurrence and antituberculosis treatment resistance were noted respectively in 6% and 3% of cases. DISCUSSION: Two questions are still discussed in the management of mycobacterial cervical lymphadenitis: 1- Is surgery necessary for the diagnosis? 2- When is surgery indicated directly? Histological specimen established the diagnosis in all cases and excluded a mestastatic lymph node. In some situations surgery must be indicated at first: cold abscess, lymph node fistulation. CONCLUSION: Surgery still has an important place in the treatment of tuberculosis lymphadenopathy.

Blockade by verapamil of cholinergic effects on atrial specialised tissue in the anaesthetised dog.

The effects of verapamil were studied in anaesthetised dogs administered dextromoramide intrathecally to provide background vagal tone. Measurements were made of spontaneous heart rate, and, in paced hearts, of conduction times in atrial muscle, the atrioventricular node (A-V node) and His-Purkinje system by means of His bundle potential recording. The effective refractory period (ERP) of A-V node was measured by the extrastimulus method. In atropinised and vagotomised animals, verapamil reduced sinus rate and increased A-V nodal conduction time. In dogs high vagal tone after dextromoramide, however, verapamil increased sinus rate and reduced A-V nodal ERP. After dextromoramide alone, A-V block was observed at an atrial pacing rate of 150 beats X min-1, but after verapamil 1:1 A-V conduction was restored. The decrease in conduction velocity in the A-V node due to ACh was neither attenuated nor enhanced by verapamil.

Enhancement by Ca2+ ions of cholinergic effects on the canine heart in situ.

The effects of Ca2+ ions were studied on the canine heart in situ, submitted to vagal influence or not. In addition to heart rate, conduction time was determined separately in atrial muscle, atrioventricular node and His-Purkinje system by means of His bundle potential recording and the effective refractory period (ERP) measured in atrioventricular node, atrial and ventricular muscle according to the extrastimulus method. In the presence of acetylcholine (ACh) released by vagal endings, an increase in plasma calcium concentration from 2.40 to 4.12 mmol/l, acutely induced by the infusion of calcium chloride, elicits the following alterations: slowing down of sinus rate, lengthening of conduction time in atrioventricular node without change of this time in atrial muscle and His-Purkinje system, prolongation of atrioventricular node ERP, but notable decrease of atrial muscle ERP and slight decrease of ventricular muscle ERP. These effects are similar to those of ACh:Ca2+ ions probably enhance the responsiveness to ACh.

Effects of hypokalemia on the various parts of the conduction system of the dog heart in situ.

The effects of hypokalemia were studied on the various parts of the conduction system by means of His bundle potential recording in the heart of vagotomized dogs. Plasma potassium concentration was lowered by extracorporeal dialysis, precautions being taken against the simultaneous impairment of other parameters, especially humoral. In order to make sure that the changes in atrioventricular conduction observed were due to hypokalemia, a control series of experiments was carried out, under strictly identical conditions except that the dialysis fluid was not devoid of potassium. The following alterations were observed during the lowering of potassium concentration from 3.2 to 1.6 mmol/l: atrioventricular node conduction time (AH interval) increased steadily up to 250% of control values; conduction time in atrial contractile tissue (SA interval) and His Purkinje system (HV interval) exhibited variations much later and much smaller; conduction time in ventricular contractile tissue was not significantly affected; effective refractory period (ERP) of atrial muscle, initially the longest in ERPs of conduction system in vagotomized animals, was shortened by about 20%. The mechanism of all these alterations is discussed.

Potentiation by hypokalemia of the effects of acetylcholine on the canine heart in situ.

In the heart in situ of vagotomized dogs, atrioventricular conduction was studied by the His bundle potential recording, sinus rate continuously registered and the effective refractory period (ERP) of the atrial muscle measured by the extrastimulus method. The modifications induced by the acute lowering of plasma potassium concentration from 3.5 to 2.0 mmol/l obtained by hemodialysis appeared to be similar to those due to parasympathetic stimulation and the effects of hypokalemia and acetylcholine (ACh) on the atrioventricular (A-V) and sinoatrial nodes as well as on the atrial contractile tissue gave rise to potentiation. Intraaortically injected near coronary ostia in a dose lower than liminal dose, ACh enhanced to a large extent all the phenomena elicited by hypokalemia, since the variations respectively observed under the influence of hypokalemia alone and the combination of hypokalemia and ACh were as follows: lengthening of conduction time in the A-V node by 100 and 180%, reduction of sinus rate by 10 and 20%, shortening of the atrial ERP by 20 and 40%.

Study of the cis-trans isomerization of enalapril by reversed-phase liquid chromatography.

Enalapril is a dipeptidic angiotensin converting enzyme inhibitor. It exists as a mixture of two conformers in solution with respect to the peptide bond involving the proline amino group. The RPLC of such products may yield peak splitting or multiple peaks as a result of the slow kinetics of the conformation change. In this study, the influence of the flow-rate, pH, temperature, organic modifier and counter ion on the peak shape and the separation of the cis and trans conformers are examined qualitatively by HPLC. It appears that decrease of relaxation time for isomerization with concomitant improvement in peak shape is favoured by a decrease in pH and flow-rate, increase of temperature, choice of organic solvent (nature, amount) and cationic counter ion concentration in the mobile phase. The elution order of the isomers was dependent on the nature of the organic modifier whereas the separation selectivity was improved by an increase of pH or the addition of a negatively charged counter ion. In addition, an NMR investigation on enalapril is described.

Reversed-phase liquid chromatography of lisinopril conformers.

The effect of flow rate, temperature, pH, organic solvent and counter ion on peak shape and separation of the cis and trans conformers of lisinopril are investigated by HPLC. It was demonstrated that complete separation of the two isomers can be achieved at low temperature at either neutral or low pH together with appropriate type and concentration of organic solvent, whereas the elution of lisinopril as a single peak is favored by a decrease of flow rate, elevated temperature, choice of organic solvent (type and amount) and the use of an appropriate counter ion concentration.

Determination and degradation study of haloperidol by high performance liquid chromatography.

A specific, high performance liquid chromatographic method was developed for the assay of haloperidol, together with an adequate separation of its degradation products. The method is based on the use of an octadecylsilane stationary phase column under isocratic conditions. The mobile phase consisted of 50 mM sodium phosphate monobasic pH 2.5-acetonitrile-THF-TEA (63:34:3:0.1, v/v/v/v) adjusted with o-phosphoric acid to a pH of 2.5. The degradation was performed in hydrochloric acid, sodium hydroxide and hydrogen peroxide. The main degradation products were identified. Application of the assay of haloperidol in tablet formulations is presented.