[Unusual benign tumors of the larynx: report of 17 cases]. / Les tumeurs bénignes rares du larynx: á propos de 17 cas.

Rare benign tumours of the larynx (RBTL) form a heterogeneous group. The clinical picture is non-specific. Based on a series of 17 cases of RBTL treated in our department, we wish to draw attention to the diagnosis, treatment and clinical course of these tumours. The mean age of the patients was 37 years, with the male sex predominating. The presenting symptom was most commonly progressive dysphonia, while 5 patients were admitted in respiratory distress. Examination and special investigations revealed 8 cases of laryngocoele, 6 cases of angioma, 2 cases of schwannoma, and one of chondroma. Treatment was surgical, by an external approach in 10 cases and endoscopically in 7. The postoperative course was satisfactory. No long-term recurrences were encountered. Conservative surgery by an external or endoscopic approach has revolutionised the functional outcome in these benign tumours.

[Papillary carcinoma from the thyroglossal duct cyst: review of the literature and report of a case]. / Carcinome papillaire sur kyste du tractus thyréoglosse: revue de la littérature et à propos d'un cas.

Cancer of a thyroglossal duct cyst is very rare. Clinical presentation is identical that of a benign cyst, and the diagnosis is histopathological. We report the case of 36 year-old woman treated for papillary carcinoma of a thyroglossal duct cyst. The treatment was surgical excision according Sistrunk method. There was no distant spread. After 22 months follow up, the patient is alive, with no signs of recurrence.

[Parotid tumors: a report of 120 cases]. / Les tumeurs de la parotide (à propos de 120 cas).

The treatment of the parotid tumors was clarified for a majority of the tumors, in spite of her histology diversity. The authors report in a retrospective study 120 cases of a parotid gland tumors during ten years over. They insist on the difficult of therapeutics, the histological diversity and the complications and sequelles of the surgery. The diagnosis was especially clinical and completed by scan and or a sialography. The superficial or total parotidectomy with preservation of facial nerve was realized in eighty-nine percent. The functional courage and the radiotherapy were associated respectively in eleven and seventeen patients. The histology was dominated by the benign tumors. The complications and sequelles were a facial paralysis definitive and a Frey's syndrome respectively in three percent cases. The ninety-seven percent patients were controlled with a mean follow up of three years. After results we must know every histologic type for to adapt his treatment. And the same complications and the sequelles were noted in all surgery type.

Deuterium isotope effects on caffeine metabolism.

The aim of this work was to study the influence of labelling on caffeine metabolism according to the incubation mode. It has been observed that labelling induces an isotopic effect on metabolisation speed: apparent half-lives are systematically increased. Moreover, isotopic effects are in agreement with those previously observed for retention times. Qualitatively, caffeine labelling systematically induces metabolic variations to the detriment of the metabolic pathway that induces the loss of the trideuteromethyl group. Caffeine accumulation and the release of the main metabolites have been studied with respect to isotopic effects on crossing the cell membrane. It has been demonstrated that, in most of the cases, accumulation decreased and that either metabolite release was increased or no isotopic effect was observed.

Isotopic effects on retention times of caffeine and its metabolites 1,3,7-trimethyluric acid, theophylline, theobromine and paraxanthine.

Physicochemical parameters that influence gas chromatographic separation are numerous. Consequently, isotope labelling, because it modifies physicochemical properties, can induce isotopic effects on retention time. Caffeine has been chosen to study this influence because as itself and its metabolites, it allows the preparation of different methylxanthine isotopomers and thus is one of the best models to study isotopic effects induced by stable isotope labelling. Using a caffeine molecule labelled with deuterium at different positions and rat hepatocytes to obtain metabolites, it was possible to study the influence of labelling on retention time [(14% cyanopropylphenyl)methylpolysiloxane] and to point out the role of each labelled site. It appears that isotopic effects induced by the labelling depend not only on the number of labelling atoms but also on whether this labelling is at position 1, 3 or 7 and, consequently, on the role of the labelled site on the function of the molecule.

Characterization of a flow-sorted human chromosome 10 cosmid library by FISH.

Fluoresence in situ hybridization (FISH) was used to localize cosmids to regions of human chromosome 10. A total of 301 cosmids were selected randomly from a flow-sorted human chromosome 10 cosmid library constructed from human x hamster cell line 762-8A and arrayed in microtiter storage dishes. Over 70% (211/301) of the cosmids mapped to unique regions of chromosome 10. About 7% (22/301) produced multiple hybridization signals indicative of chimeric clones or sequences repeated at low copy number. Three cosmids (3/301, or 1%) hybridized to the centromeric regions of chromosome 10 and one or more other human chromosomes. About 19% (59/301) consisted mostly or entirely of hamster DNA inserts, and about 2% (6/301) appeared to be nonrecombinants.

[Osteoma of the frontal sinus. Apropos of 10 cases]. / L'ostéome du sinus frontal. A propos de 10 cas.

The authors report 10 cases of frontal sinus osteoma. The patient group consisted of 5 men and 5 women, ranging in age from 15 to 60 years. The most common revelating symptom was headache. Treatment depends on tumor size, its course, and complications. Transfacial incision was used in 3 cases and Cairns Unterberger approach in 5 cases. Post operatively anatomic and esthetic results were good, without recurrences.

[Aneurysmal bone cyst of the mandible. Apropos of a case and review of the literature]. / Le kyste anévrysmal osseux de la mandible. A propos d'un cas et revue de la littérature.

Aneurysmal bone cyst is a benign lesion, rarely found in the craniofacial region and exceptionally in the mandible. One previously unreported case originally in the mandible is presented with a review of the literature. The authors insist on pathological diagnostic and therapeutic characteristics.

[Laryngocele as an etiology of respiratory distress]. / La laryngocèle comme étiologie de la détresse respiratoire.

Laryngocele is usually benign affection of the larynx. But serious forms of clinical emergency necessitating tracheotomy are possible. We reported 3 cases. New methods of treatment are presented endoscopic resection and laser marsupialization.

[Abscess of the posterior cranial fossa. Apropos of 10 cases]. / Les abcès de la fosse cérébrale postérieure. A propos de 10 cas.

In this study, a series of 10 cases of abscess of the posterior cerebral fossa is analysed. In our department, the incidence of this condition is 2 cases per year. These predominantly occur in juvenile male and are frequently caused by adjacent ENT disease. Numerous therapeutic approaches are possible. In our series, 3 patients underwent emergency surgery with simultaneous treatment of the abscess of the ear. A second series of 6 patients underwent delayed treatment of the ENT infection (over 2 weeks) after the emergency puncture of the abscess. The rapid and good recovery of the 3 patients who underwent simultaneous petromastiodectomy and puncture of the abscess during surgery should be emphasized.

[Mucocele of the maxillary sinus. Apropos of 3 cases]. / Les mucocèles du sinus maxillaire. A propos de trois cas.

Mucocele of the maxillary sinus is a rare affection his pathogenesis is still discussed, with a prevalence of the injury's and inflammatory's theories. The diagnosis being confirmed by computed tomography imaging ... We report in this study, 3 cases of maxillary sinus mucocele, with a review of literature.

Gas chromatographic-mass spectrometric quantitation of tri-, di- and monomethylxanthines and uric acids from hepatocyte incubation media.

A gas chromatographic-mass spectrometric method is described for the measurement of the concentration of fourteen methylxanthines and methyluric acid metabolites of methylxanthines, especially caffeine, from cell incubation media. The method shows linearity, accuracy and recovery suitable for metabolic studies. The reproducibility of relative retention times is satisfactory (less than 0.07%) and allows rapid and conclusive identification of chromatographic peaks corresponding to metabolites. Moreover, this method enables the simultaneous determination of 3.7-methylxanthine and its 1.7-isomer, which are not chromatographically resolved. This method can be successfully applied when molecules labelled with stable isotopes are used as tracers for metabolic studies.

Pharmacokinetic equivalence of 5(ethyl(2H)5)- and unlabelled phenobarbitone.

The present study shows the absence of in vivo pharmacokinetic isotope effect on phenobarbitone (PB) C5-ethyl deuteration (PBd5) following oral administration to man of equimolar PB/PBd5 mixtures (0.40 mmol each). Plasma PB and PBd5 (17 days) and urine PB, PBd5 and parahydroxy-metabolites (PBOH, PBHOd5) levels were determined by GC-MS. Isotope effect research includes comparison of pharmacokinetic parameters, study of time-dependence of isotope ratios (IRs) in plasma and urine (linearity test), comparison of IRs between samples and administered mixtures (Mann Whitney's test) and comparison of PBOH/PBOHd5 ratios before and after urine enzymatic hydrolysis (Student's two tailed t-test). No significant isotope effect was observed on pharmacokinetic parameters, PB hydroxylation or PBOH conjugation (x less than or equal to 5%); which the absence of pentadeuteration-induced alteration in PB's HSA binding parameters (binding mode, Ka, N) corroborates (x less than or equal to 5%). These results establish bioequivalence of PB and PBd5; the latter can be used with benefit in stable-isotope clinical pharmacology (steady state pharmacokinetics, drug interactions...) investigations as well as bioavailability studies of PB preparations.

Influence of hyperlipidic food on the kinetics of slow-release formulations of theophylline.

A cross-over study of kinetics has been undertaken in 12 healthy adults volunteers using two sustained-release theophylline products that allow once a day dosing (Theo-Dur tablets and Dilatrane A.P. bead filled capsules) to compare the i.v. pharmacokinetic profiles when taken with an hyperlipidic meal and a balanced standard meal. Each subject took part in four phases in randomised order, corresponding to all possible combinations of the products and the types of meal. Each phase involved a single dose of 9 to 11 mg.kg-1 theophylline administered at 20.00 h, at the beginning of the meal, with 100 ml water. The two formulations were found to be bioequivalent with both types of meal. Taken with a balanced meal, the mean parameters were similar; for Theo-Dur and Dilatrane A.P. they were respectively: Cmax: 11.32 mg.l-1 which plateaued from 8 to 10 h after dosing and 10.9 mg.l-1, which plateaued after 6 to 10 h; AUC 230 mg.h.l-1 and 220 mg.h.l-1; and MRT 18.2 h and 17.7 h. After the hyperlipidic meal the values for Theo-Dur and Dilatrane A.P. respectively, were: Cmax 10.9 mg.l-1 at 12 h and 11.3 mg.l-1 at 10 h; AUC 237 mg.h.l-1 and 227 mg.h.l-1; and MRT 19.2 h and 18.9 h. In spite of a decrease in the absorption rate, which led to a shift to the right of about 2 h of the plasma concentration-time curve, the bioavailability of both formulations were not significantly modified by a hyperlipidic meal as compared to a balanced meal.(ABSTRACT TRUNCATED AT 250 WORDS)

Simultaneous quantitation of phenobarbitone and p-hydroxyphenobarbitone and their perdeuteroethyl analogues in biological fluids by combined gas chromatography-mass spectrometry.

In order to develop 5-pentadeuteroethyl-5-phenyl barbituric acid as an alternative tracer in pharmacokinetic and metabolic studies of phenobarbitone, and to search for possible isotope effects associated with such labelling, we propose a gas chromatographic-mass spectrometric assay for simultaneous measurement of phenobarbitone, p-hydroxyphenobarbitone and their perdeuteroethyl analogues, using [1,3-15N2,2-13C] phenobarbitone as internal standard. These compounds were extracted from plasma (50 microliter) or urine (500 microliter) and pentylated according to Greeley's method. Linear calibration curves were obtained in the concentration range from 0.5 to 3 micrograms/ml. The interday precision, mean accuracy and detection limit were 0.77-5.28%, 99.99-100.80% and 0.03-0.05 microgram/ml, respectively. Results for plasma and urine concentrations, and pharmacokinetic parameters in humans, are presented to illustrate this method.