Growth hormone excess and sternohyoid muscle mechanics in rats.

In vitro isotonic and isometric mechanical properties of the sternohyoid (SH) muscle, an upper airway dilator muscle, were studied in rats with a growth hormone (GH)-secreting tumour (GH tumour group; n = 10). The effects of muscle fatigue were also studied. Stress and shortening were measured in muscles contracting from zero load up to isometric load under tetanic conditions. Isometric stress and maximum unloaded shortening velocity were determined and compared with values obtained from control rats (n = 10). Crossbridge kinetics and energetics and mechanical efficiency were calculated from Huxley's equations. Compared with controls, isometric stress, mechanical efficiency, crossbridge number and crossbridge single force were lower in the GH tumour group. The probability of crossbridge being in the power stroke configuration was lower in the GH tumour group than in controls. Muscle fatigue significantly impaired maximal muscle efficiency and crossbridge single force in the GH tumour group but not in controls. In conclusion, mechanical and energetic properties of the SH muscle and crossbridge properties were worse in the GH tumour group than in controls. This may partly account for impairment of the upper airway dilator muscle function and the increased occurrence of obstructive sleep apnoea in acromegaly.

Observation of quantum topological Hall effect in the Weyl semimetal candidate HgSe.

The magnetoresistance (MR) and Hall effect of a single HgSe crystal with an extremely low electron concentration of 8.8 × 1015 cm-3 were studied in a quantising magnetic field applied both along and across the direction of the electric current. As the result, a broad plateau was discovered in the ordinary (transverse) Hall resistance in the quantum limit. Within a framework of quantum spin Hall effect for an inversion breaking Weyl semimetal, we associate this plateau with a contribution to Hall conductivity from Chern insulator edge states when only a zero Landau level is occupied. In addition to the plateau in the quantum limit, we also detected a well-developed plateau-like behaviour in a phenomenologically-introduced 'longitudinal' Hall resistivity. In the 'longitudinal' Hall conductivity, a step-like behaviour was revealed, which we identify with the discovery of half-integer quantum spin Hall effect in HgSe. This effect, being purely topological in origin, supplements the non-trivial Weyl semimetal physics and may serve as a promising magnetotransport method for the detection of Weyl nodes in a studied material.

Nontrivial topology of bulk HgSe from the study of cyclotron effective mass, electron mobility and phase shift of Shubnikov-de Haas oscillations.

In this paper, the authors report the results of an experimental study of effective mass, electron mobility and phase shift of Shubnikov-de Haas oscillations of transverse magnetoresistance in an extended electron concentration region from 8.8 × 1015 cm-3 to 4.3 × 1018 cm-3 in single crystals of mercury selenide. The revealed features indicate that Weyl semimetal phase may exist in HgSe at low electron density. The most significant result is the discovery of an abrupt change of Berry phase [Formula: see text] at electron concentration [Formula: see text] 2 × 1018 cm-3, which we explain in terms of a manifestation of topological Lifshitz transition in HgSe that occurs by tuning Fermi energy via doping.

Relevance of Choukroun's Platelet-Rich Fibrin (PRF) and SMAS flap in primary reconstruction after superficial or subtotal parotidectomy in patients with focal pleiomorphic adenoma: a new technique.

AIM OF THE STUDY: Parotidectomy leaves a retromandibular hollow area in proportion with the amount of gland resected. Many surgeons perform primary reconstruction after superficial or subtotal parotidectomy in patients with exo-facial pleiomorphic focal adenoma. Many techniques have been proposed. We present a new technique of filling of the parotidectomy chamber by a second generation leucocyte and platelet concentrate, Platelet-Rich Fibrin (PRF, Choukroun's method). PATIENTS AND METHODS: 10 patients were included in this preliminary study. Subtotal parotidectomy was performed through classic procedure or lifting procedure. The macroscopic security margin of resection usually allowed performance of a SMAS flap. PRF was prepared following the original Choukroun's method. RESULTS AND DISCUSSION: PRF slow resorption after filling of the exeresis cavity, offers a key aesthetic interest. The fibrin matrix of this biomaterial has many angiogenic and healing properties. Synergetic action of the fibrin and the platelets cytokines within PRF may improve revascularization and postoperative resumption of facial nerve function. The membrane formed by the fibrin dense fibrillary network, as well as the SMAS flap, may help to prevent the Frey's syndrome. CONCLUSION: We propose the use of PRF as a filling, healing and interposition material after parotidectomy for benign parotid tumors. Preliminary results are very encouraging. Longer prospective evaluation of this technique is necessary.

Chiari malformation and sleep related breathing disorders.

OBJECTIVE: To estimate the frequency, mechanisms and predictive factors of sleep apnoea syndrome (SAS) in a large group of children and adults with type I (CMI) and II (CMII) Chiari malformation (CM). BACKGROUND: The anatomical and functional integrity of both respiratory circuits and lower cranial nerves controlling the upper airway is necessary for breathing control during sleep. These latter structures may be altered in CM, and a few investigations have reported CM related sleep disordered breathing. METHODS: Forty-six consecutive unrelated patients with CM (40 CMI, six CMII), of which 20 were children (eight males) and 26 were adults (12 males), underwent physical, neurological and oto-rhino-laryngoscopic examination, MRI and polysomnography. RESULTS: SAS was present in 31 (67.4%) of the patients with CM (70% of CMI, 50% of CMII, including mainly children). Sixty per cent of children with CM exhibited SAS, including 35% with obstructive (OSAS) and 25% with central (CSAS) sleep apnoea syndrome. SAS was observed in 73% of CM adults (57.7% OSAS, 15.4% CSAS). Severe SAS was found in 23% of CM adults. Multiple regression analysis revealed that age, type II Chiari and vocal cord paralysis predicted the central apnoea index. CONCLUSION: SAS is highly prevalent in all age groups of patients suffering from CM. CSAS, a rare condition in the general population, was common among the patients with CM in our study. Sleep disordered breathing associated with CM may explain the high frequency of respiratory failures observed during curative surgery of CM. Our results suggest that SAS should be systematically screened for in patients with CM, especially before surgery.

Lower respiratory tract foreign bodies: a retrospective review of morbidity, mortality and first aid management.

OBJECTIVES: The authors describe 28 pediatric cases of foreign body inhalation requiring treatment in intensive care units between 1987 and 1999. The purpose of this study was: (1) to analyze the circumstances, diagnostic difficulties and initial treatment of serious foreign bodies and (2) to compare our series with other literature descriptions and define principles for optimal prevention and initial treatment. METHODS: Twenty-one children presented a penetration syndrome, which was responsible in 13 cases for asphyxia with cardiorespiratory arrest. All these children died, regardless of the initial treatment. Seven children were hospitalized for apparent asthmatic symptoms that did not respond to traditional treatment. RESULTS: The inefficiency of external extraction methods like the Heimlich maneuver and the mean delay between clinical signs and initial treatment lead us to propose a new strategy for the emergency treatment of foreign bodies with asphyxia. CONCLUSIONS: We recommend that emergency teams promote the use of a laryngoscope and Magill forceps. Flexible endoscopy is still recommended as the appropriate diagnostic tool to eliminate doubt in the case of a first severe asthma attack.

Potential doubling time and clinical outcome in head and neck squamous cell carcinoma treated with 70 GY in 7 weeks.

PURPOSE: To study the predictive value of pretreatment potential doubling time and labeling index, as measured by flow cytometry in patients with head and neck squamous cell carcinoma treated with conventional radiotherapy. METHODS AND MATERIALS: 70 patients with a squamous cell carcinoma of the oropharynx and 4 patients with another involved head and neck site were entered in this prospective study. The duration of the S phase (TS), the labeling index (LI), and the potential doubling time (Tpot) were obtained by flow cytometry measurements of a tumor biopsy obtained after i.v. injection of 200 mg bromodeoxyuridine to the patient. The treatment consisted of 70 Gy in 7 weeks, 2 Gy per fraction and five fractions per week. RESULTS: The mean and median LI were 7.7% (standard deviation, SD: 5.0) and 6.3%, respectively. The mean and median TS were 9.3 h (SD: 3.6) and 8.3 h, respectively. The mean and median Tpot were 5.6 days (SD: 5.4) and 4.6 days, respectively. No significant relationship was found between the Tpot or LI and the tumor stage (T), nodal status (N), histological grade, and the site of the primary within the oropharynx. The only parameter significantly associated with an increased risk of local relapse was the tumor stage (p < 0.001). The mean Tpot for the group of tumors that relapsed locally was 5.3 days (SD: 3.3), compared to 6.1 days (SD: 4.08) for those who did not relapse locally (NS). Two parameters were significantly associated with a decrease in disease-free (DFS) and overall survival, namely the tumor stage (p < 0.005, and p < 0.001, respectively, for DFS and overall survival) and nodal involvement (p = 0.02 and (p < 0.005, respectively, for DFS and overall survival). The TS, LI, DNA index, and Tpot were not significantly associated with local relapse, DFS, and survival, either in the univariate or in the multivariate analysis. CONCLUSIONS: The method used to evaluate tumor cell kinetics did not provide clinically relevant kinetic parameters for this type of cancer. The classic prognostic factors (tumor stage and nodal status) were strongly associated with clinical outcome.

Magnetic resonance findings in 92 acoustic neuromas.

A retrospective analysis of the MR findings in 92 cases of acoustic neuromas is presented. The method of examination included in all cases intravenous injection of Gadolinium (Gd-DTPA or DOTA) with realization of sections in the axial and coronal planes. In 21 cases native MR studies were performed in the axial plane, before Gadolinium injection, with T1WI (n = 21), and T2WI (n = 6) images. Tumors were strictly intracanalar in 19 cases (20.7%), only localized in the cerebellopontine angle (CPA) in 5 cases (5.4%), and in 68 cases (73.9%) the tumors had intra- and extracanalar components. In this last group of lesions, 63.2% completely filled the internal auditory canal (IAC), and 36.8% occupied the internal portion of the IAC. In most cases (85.3%) the mean diameter of the CPA component was less than or equal to 2.5 cm. Lesions were more frequently homogeneous (58.8%) after Gd i.v.-enhancement. Heterogeneity was noted mainly in large lesions (greater than 2.5 cm: 100%). In all cases but one, the tumors were round, or oval-shaped, well-delineated, and did not present significant contact with the petrous bone. In 80.9% of CPA lesions, the center of the tumor was posteriorly excentered in relation to the internal auditory canal, whereas it was centered in 16.2% of cases. Widening of the IAC was observed in 51.1% of cases. In 45.2% of tumors of the CPA, smoothing of the posterior edge of the porus was visible.

IGF -I plasma concentrations in non-treated horses and horses administered with methionyl equine somatotropin.

Insulin-like growth factor-I (IGF -I) is likely to be an indicator of somatotropin (ST) administration in the horse. To investigate the different ways ST administration may be detected, the following aspects of IGF -I concentrations in plasma were studied: (i) the daily variation; (ii) variation following a treadmill test; (iii) concentrations at rest and after exercise; and (iv) concentrations in plasma from two young horses and two adults treated with methionyl equine somatotropin (e ST). In the population of horses at rest, IGF -I mean concentration (SEM) was 261 (104) ng ml(-1). In post race samples, IGF -I mean concentration was 187 (100) ng ml(-1). All of these data indicate that exercise does not modify IGF -I concentration in plasma. The magnitude of the increase in IGF -I following administration of e ST differed according to the age of the horses. The critical value of 700 ng ml(-1)was exceeded for 1 day in adult horses and for at least 11 days in young horses. These results show that IGF -I has potential as an indirect marker of ST administration in horses.

Treatment of infantile subglottic hemangioma. A report of 49 cases.

Forty-nine laryngeal subglottic hemangiomas were observed in infants over a 9-year period. The diagnosis was always confirmed by direct laryngoscopy. The outcome of 42 of these hemangiomas was studied. A total of 26 infants recovered completely after medical treatment and 16 were intubated; only 4 underwent a tracheostomy. Short-term steroid therapy was sufficient in 7 infants, but long-term administration of corticosteroids was necessary in 14 cases. In 10 of the 16 intubated cases it was possible to withdraw corticosteroids permanently. Of the 6 remaining cases, 32P contact radiation therapy was tried in 2 cases of which one was successful, CO2 laser in 2 cases without success, tracheostomy alone in one case and one child died 2 months after extubation, without dyspnea. This series leads us to recommend corticosteroids as a first therapeutic step and short-term nasotracheal intubation if unsuccessful.

Fistulae of the fourth endobranchial pouch.

Eight cases of laterocervical cystic tumor occurring during childhood are described. Three cases presented in the neonatal period as an obstructive tumor. Five cases presented in bigger children as recurrent abcess of the neck. Two of those were initially considered as acute suppurative thyroiditis. Laryngoscopy revealed, in all cases, a fistula originating from the apex of the pyriform sinus. Considering the pharyngeal connections, the anatomical route and the pathological reports, we believe that these cysts are derived from the 4th endobranchial pouch. A review of the literature of the past 10 years reveals only 14 reported cases of laterocervical tumors of similar origin.

Congenital tracheoesophageal fistula without esophageal atresia.

The authors report a series of eight cases of isolated tracheoesophageal fistula without esophageal atresia (or an H type fistula), treated in three pediatric ENT departments. This is a rare malformation whose diagnosis requires investigation for associated anomalies. The clinical signs are mainly respiratory but also digestive and the symptomatology can be severe. The diagnosis can be made with a barium swallow combined with cineradiography, but a tracheoesophageal endoscopy remains the investigation of choice. The treatment is surgical. In most cases, the fistula is accessible by a right or left cervicotomy, depending on the surgeon's practice, with a much lower postoperative morbidity as compared to a thoracotomy. The postoperative management was straightforward in most of our cases. We discuss the role of gastro-esophageal reflux with respect to postoperative morbidity as well as systematic treatment for reflux peri-operatively. The pros and cons of the various surgical approaches are also discussed.

Laryngotracheal manifestations of gastroesophageal reflux in children.

Gastroesophageal reflux is generally a benign condition, which resolves spontaneously, and which is usually manifested by digestive signs. More recently, laryngotracheal conditions such as laryngospasm, laryngomalacia and recurrent laryngitis, have been ascribed to gastroesophageal reflux. However, there is not a single common mechanism linking these two pathologies and different theories are postulated. Diagnosis of gastroesophageal reflux is based essentially on prolonged pH monitoring, where a negative result unfortunately cannot rule out reflux responsibility. Thus, in the end, in the face of a sufficient body of evidence, it is the effectiveness of the anti-reflux treatment which will make it possible to establish a link between gastroesophageal reflux and the laryngotracheal manifestations observed.

[Severe tracheo-bronchial compression caused by a circumflex aorta. Apropos of 3 cases treated by aortic uncrossing]. / Compression trachéo-bronchique sévère par une aorte circonflexe. A propos de trois cas traités par décroisement aortique.

The cases of three children with an encircling right aortic arch and left sided descending aorta illustrate the fact that this rare abnormality may cause severe compression of the tracheo-bronchial axis. A ventricular septal defect was associated to the abnormal vascular arch in all three cases. The compressive structure was the aorta and these children could only be extubated after surgical uncrossing . Before diagnosing tracheomalacia in a child operated for an abnormal vascular arch, residual compression must be excluded by tracheo-bronchial fibroscopy.

[The place of MRI in the study of cerebrospinal fluid fistulas]. / Place de l'IRM dans l'exploration des fistules de liquide céphalo-rachidien.

Results of CT and MRI explorations in 8 patients with cerebrospinal fluid (CSF) fistulae are reported and compared with surgical findings in 7. Sensitivity of MRI (CISS and fast T2 spin-echo sequences) was excellent giving perfect correlations with surgical findings in 7/7 cases. CT and MRI were found to provide complementary information suggesting they should be used in combination as first intention explorations of suspected CSF fistulae. Computerized cisternography should be used if MRI is contraindicated or if a clinically and biologically proven CSF fistulae is not visualized by CT or MRI.

[MRI in the diagnosis of recurrent cholesteatoma of the petrous bone]. / Apport de l'IRM dans le diagnostic des cholestéatomes récidivants du rocher.

Nine cases of recurrent petrous cholesteatomas have been studied by a 1,5 T MR unit. Gadolinium was injected in 1 case. In all cases, comparison between MR, CT and clinical findings were made. MR allows for accurate topographic study and assessment of cholesteatomas extension, in particular in the posterior fossa and skull base. Relationships with the internal carotid artery and the jugular vein are clearly depicted.

[Sinusal penetration of amoxicillin-clavulanic acid. Formulation 1 g./125 mg., twice daily versus formulation 500 mg./125 mg., three times daily]. / Pénétration sinusienne de l'amoxicilline-acide clavulanique. Formulation 1 g/125 mg, 2 fois/jour, versus formulation 500 mg/125 mg, 3 fois/jour.

INTRODUCTION: In order to meet the evolution of pneumococcus resistance to beta-lactam antibiotics, a new formulation of amoxicillin (AMX) and clavulanic acid (CA), with twice as much AMX (1 g/125 mg vs. 500 mg/125 mg) was developed for the treatment of acute pneumonia in patients at risk. This formulation can also be used in the treatment of acute maxillary sinusitis using a 1 g/125 mg regimen twice-daily. OBJECTIVES: Compare the sinusal penetration of AMX and CA (1 g/125 mg twice-daily vs. 500 mg/125 mg three times a day) when administered at both regimens to demonstrate equivalent pharmacokinetic and pharmacodynamic behaviour of the former when compared to the latter. METHODS: Concentrations of AMX and CA were measured in the anterior ethmoid, maxillary, posterior ethmoid sinus and in the middle nasa concha in 62 patients undergoing surgery for nasosinusal polyps. Patients randomised in two groups corresponding to 2 oral regimens, received either 1 g/125 mg twice a day or 500 mg/125 mg three times a day for 4 days. The last dose in both groups was administered 1 h 30, 3, 5 or 8 hrs prior to surgery. Serum samples were taken simultaneously to tissue samples. AMX and CA were measured by high performance liquid chromatography. Exogenous and above all endogenous blood contamination were taken into account with the hematocrit as well as blood and tissue haemoglobin concentrations. Comparisons of tissue concentrations were made for each sampling time, according to values obtained for a specific tissue with both doses on one hand, and on the other to values obtained with a specific dose in different tissues. The calculated pharmacodynamic parameters, which are considered to be predictive for bacteriological and clinical efficacy, result directly from tissue concentrations of AMX. tissue inhibitory quotients (IQtissue = Tissue concentration/MIC). time above MICs for serum and tissue concentrations (T > MIC). RESULTS: As regards AMX, whatever the dose, at 1 h 30 and at 3 hrs, tissue concentrations did not differ significantly whatever the tissue studied (from 1.1 to 2.5 micrograms/g). Conversely, at 5 and 8 hrs, they were greater than after the 1 g/125 mg regimen given twice-daily (0.06-0.7 vs. 0.7-1.8 micrograms/g). If we consider a given dose, the comparison between the various tissues showed identical concentrations in the four tissues studied at each sampling time, except in two cases with the dose of 500 mg/125 mg 3 times a day. T > MIC for serum and tissue showed higher values than those required for AMX/pneumococcus association (40-50%) with, nevertheless, greater tissue values for the 1 g/125 mg dose given twice-daily when MIC was of 1 microgram/ml (40-52% vs. 50-66%). The maximum tissue inhibitory quotients were also greater with the twice-daily 1 g/125 mg dose, when calculated with MIC 50 or 90 of S. Pneumoniae, H. influenzae, M. catarrhalis or S. pyogenes. As for CA, concentrations were equivalent for both doses at each sampling time and greater than those required in vitro during respectively 4 and 5 hours for beta-lactamases H. influenzae and M. catarrhalis. DISCUSSION-CONCLUSION: A least an equivalence between both dose regimens was observed, with occasionally a superiority of the twice-daily 1 g/125 mg dose, in terms of pharmacokinetics, tissue penetration and pharmacodynamics for both AMX and CA. This new regimen therefore appears more appropriate for the treatment of acute maxillary sinusitis in adults.

[Spectral study of laryngotracheal sounds. Methodological approach and perspectives]. / Etude spectrale des bruits laryngo-trachéaux. Approche méthodologique et perspectives.

Prior studies have shown that laryngotracheal sounds are vectors of objective information which indicate the origins and mechanisms of sound production. The first objective of this study is to confirm these earlier findings on a larger scale. The second objective is to develop a simple apparatus which permits the rapid acquisition and analysis of information for a prompt diagnosis. This study will be carried out in infants referred to the Department of otolaryngology of the Kremblin-Bicêtre Hospital over the next two years. The material and methods used are described.

[Laryngeal cysts in the newborn (9 cases) (author's transl)]. / Les kystes du larynx chez le nouveau-né. (A propos de 9 observations).

Nine cases of laryngeal cysts in the newborn were seen over a period of 8 years. After reviewing data from the literature, the authors emphasise treatment. Simple puncture aspiration was invariably followed by a recurrence. Marsupialisation or endoscopic resection was associated with 5 successful results. An external operative approach was necessary in 4 cases because of multiple recurrences. No tracheotomy was necessary.

[Cat scratch disease. Apropos of a misleading case]. / Maladie des griffes du chat. A propos d'une forme trompeuse.

An unusual case of cat scratch disease was reported. A pharyngeal form of the disease, with a primary site of inoculation in the nasopharynx was observed. The histology showing pseudo-tubercular follicules was misleading the diagnosis finally made by a strongly positive Hanger Rose reaction. From this case we are reviewing the main caracteristics of this disease and especially forms with mucosal inoculation.