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.

[Pathophysiology of right ventricular hemodynamics]. / Physiopathologie hémodynamique du ventricule droit.

The right ventricle (RV) plays a key role in the maintenance of an adequate cardiac output whatever the demand, and thus contributes to the optimization of the ventilation/perfusion ratio. The RV has a thin wall and it buffers the physiological increases in systemic venous return without causing a deleterious rise in right atrial pressure (RAP). The RV is coupled to the pulmonary circulation which is a low pressure, low resistance, high compliance system. In the healthy subject at rest, the contribution of the RV to right heart systolic function is surpassed by the contribution of both left ventricular contraction and the respiratory pump. RV systolic function plays a contributory role during exercise and in patients with pulmonary hypertension. The RV compensates better for volume overload than for pressure overload and is more capable of sustaining chronic increases in load than acute ones. An impaired RV-pulmonary artery coupling leads to a major mismatch between RV function and arterial load ("afterload mismatch") and is associated progressively with a low cardiac output and a high RAP. Right ventricular dysfunction is involved in the pathophysiology of both cardiovascular and pulmonary diseases, and may partly explain the deleterious haemodynamic consequences of mechanical ventilation.

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.

Efficacy and safety of pre-Descemet's membrane sutures for the management of acute corneal hydrops in keratoconus.

AIMS: The aim of this study was to assess the efficacy and safety of pre-Descemet's membrane (DM) sutures associated with intracameral air injection for management of acute corneal hydrops associated with keratoconus. METHODS: We carried out a retrospective interventional study of seven consecutive cases. Three to seven pre-DM sutures with 10-0 nylon were applied perpendicularly to the tear as close as possible to DM, under general anaesthesia. An air bubble was injected into the anterior chamber at the end of each procedure. RESULTS: Corneal oedema began to decrease from day 1 after surgery in all our patients. Best-corrected visual acuity progressed from 2.13 to 1.65 logMar (p=0.031) 1 month after surgery, and from 2.13 to 0.84 logMar (p=0.016) 2 months after surgery. The mean corneal thickness measured by anterior segment optical coherence tomography decreased from 1472 µm (range 689-2770 µm) on day 0 to 909 µm (range 484-1640 µm) on day 1 (p=0.016), 716 µm (range 484-1380 µm) on day 15 (p=0.016) and 528 µm (range 404-618 µm) 1 month after surgery. CONCLUSIONS: Our results suggest that intrastromal pre-DM sutures and intracameral air injection could promptly restore imperviousness of posterior stroma. This technique seems to be a safe and useful procedure to shorten acute corneal hydrops.

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.

Impaired load dependence of diaphragm relaxation during congestive heart failure in the rabbit.

The load dependence (LD) of relaxation was studied in the diaphragm of rabbits with congestive heart failure (CHF). CHF (n = 15) was induced by combined chronic volume and pressure overload. Aortic insufficiency was induced by forcing a catheter through the aortic sigmoid valves, followed 3 wk later by abdominal aortic stenosis. Six weeks after the first intervention, animals developed CHF. Sham-operated animals served as controls (C; n = 12). Diaphragm mechanics were studied in vitro on isolated strips, at 22 degrees C, in isotonic and isometric loading conditions. Contractility was lower in the CHF group, as reflected by lower total tension: 1.11 +/- 0.10 in CHF vs. 2.38 +/- 0.15 N/cm(2) in C in twitch (P < 0.001) and 2.46 +/- 0.22 in CHF vs. 4.90 +/- 0.25 N. cm(-2) in C in tetanus (P < 0.001). The index LD was used to quantify the load dependence of relaxation: LD is <1 in load-dependent muscles and tends toward 1 in load-independent muscles. LD was significantly higher in CHF than in C rabbits, in both twitch (0.99 +/- 0.01 vs. 0.75 +/- 0.03; P < 0. 001) and tetanus (0.95 +/- 0.02 vs. 0.84 +/- 0.02; P < 0.001). In the CHF rabbits' diaphragm, the fall in total tension was linearly related to the fall in load dependence of relaxation. The decrease in load dependence of relaxation in CHF animals suggests sarcoplasmic reticulum abnormalities. Impairment of the sarcoplasmic reticulum may also partly account for the decrease in contractile performance of diaphragm in CHF animals.

Telithromycin (HMR 3647) achieves high and sustained concentrations in tonsils of patients undergoing tonsillectomy.

Telithromycin, the first ketolide antimicrobial to be developed for clinical use, has potent activity against group A beta-haemolytic streptococci (GABHS), including macrolide-resistant strains. The penetration of telithromycin into tonsils was assessed in 22 adults undergoing tonsillectomy at 3, 12 or 24 h after the fourth dose of oral telithromycin 800 mg once daily. Telithromycin rapidly penetrated tonsillar tissues, achieving a mean concentration of 3.95 mg/kg at 3 h post dose, 3.4 times greater than the corresponding plasma concentration (1.22 mg/l. The mean tonsil:plasma concentration ratio increased to 13.1 at 24 h post dose, indicating slower elimination from tonsils than plasma. Tonsillar and plasma concentrations exceeded the MIC(50) for GABHS throughout the 24-h dosing period. These findings suggest that telithromycin may be an effective new alternative treatment for GABHS tonsillopharyngitis.

Interaction between tracheal sound and flow rate: a comparison of some different flow evaluations from lung sounds.

We simultaneously recorded tracheal sound and air flow from nine normal subjects (seven males and two females). Sound was picked up at the supra sternal notch with an air-coupled sensitive microphone held in a small airtight probe. Flow was measured at the mouth using a pneumotachograph Fleisch n degrees 2. Both sound and flow were directly digitized at a sampling rate of 5120 Hz and then divided in 128-sample blocks. For each sound block the frequency spectrum was computed using the fast Fourier transform. In order to evaluate instantaneous flow-rate from tracheal sounds we investigated eight methods divided in two groups of four. In the first group (i.e., reference curves methods), we assumed that a relationship existed between sound and flow and was thus reflected by the variations of certain parameters. We chose to use simple straightforward relationships, already known and published. We tested four different parameters. During a calibration phase, we built for each parameter P a reference curve representing the variations of P versus flow and being specific to each subject. Then, an unknown flow was evaluated in calculating P on a 128-sample block, and the reference curve gave the corresponding flow. In the second group, we made a hierarchial clustering analysis of sound spectra for revealing the frequency modifications, induced by the flow. We tested two kinds of spectra as well as two ways of associating a flow to a given cluster. This led us to four other methods for calculating the flow. All the eight methods but one gave a mean uncertainty in the measure of flow of about 15%.(ABSTRACT TRUNCATED AT 250 WORDS)

Magnetic resonance imaging in patients with penile carcinoma.

The aim of the study was to determine the role of pre-operative magnetic resonance imaging (MRI), with and without contrast enhancement, in patients with penile carcinoma. Nine patients with a penile cancer were studied. The staging of the tumours was performed by clinical examination, MRI and surgery, according to the TNM classification. Six patients had primary tumours, of clinical stage T1 (n = 1) and T2 (n = 5). Three other patients had been previously treated and presented with a local recurrence of clinical stage T2. Surface-coil MRI was performed at 0.5 T with T1 weighted sequences before and after gadolinium-DOTA, and T2 weighted sequences. MRI results were compared with the clinical and surgical findings. T1 weighted sequences did not clearly demonstrate the margins of the tumours. T2 weighted sequences were the more useful in five patients, whereas contrast enhanced T1 weighted sequences allowed better delineation of the lesions in only three patients. Therefore, an imaging protocol should include spin echo T2 weighted sequences. Clinical examination correctly staged six of nine tumours; MRI, seven of nine tumours and the combination of both examinations, eight of nine tumours. MRI provided good evaluation of tumoral invasion into the penile shaft.

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.

[Digital radiography of the thorax]. / Radiologie numérique du thorax.

Digital radiography of the thorax can, now be substituted to conventional chest radiography. Computed radiography with phosphor plates and the new selenium detector are emphasized. The major image processing are explained. Successively the main other methods of digital radiography are described: scanning equalization radiography, laser-digitized radiography and multiwire proportional chambers. Then the advantages and the drawbacks of chest computed radiography are extensively reviewed.

[Cervico-mediastinal recurrences of differentiated thyroid cancers: value of MRI]. / Récidives cervico-médiastinales des cancers thyroïdiens différenciés: valeur de l'irm.

AIM: The aim of this study was to evaluate the ability of MRI to detect recurrent differentiated thyroid carcinomas developed in the neck or the upper mediastinum. RESULTS: MRI was performed in 25 patients, and was compared in 5 cases with surgery. In 20 cases it was compared with I-131 scintigraphy (100 mCi in 14 cases and 5 mCi in 6 cases). The sensibility, specificity and overall accuracy of MRI was respectively: 100%, 66.6%, 82.6%. COMMENTARY: MRI is a good technique to detect recurrent thyroid carcinomas. It is specially interesting to investigate patients with a biological suspicion of recurrence and a negative scintigraphy. Mediastinal localisations that cannot be detected by US can be detected by MRI.

[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.

[Meningocerebral hernia and defects of the tegmen. Diagnosis and surgical treatment]. / Hernies méningo-cérébrales et brèches du tegmen. Diagnostic et cure chirurgicale.

Eight defects of the tegmen tympani or antri have been operated on during the last two years. Among these cases, 4 brain herniae were associated with the defect of the tegmen. Magnetic resonance imaging permitted to evaluate accurately the space occupying lesions into the mastoid cavity and disclosed the brain and/or meningeal herniations. The defect of the tegmen was oblitered through a middle fossa approach whereas the hernia was resected through a mastoid approach when necessary.

[Therapeutic strategy for cervicofacial lymphangioma in children]. / Attitude thérapeutique devant les lymphangiomes cervico-faciaux de l'enfant.

The authors report a series of 22 cervicofacial lymphagiomas treated from 1984 to 1990, and try to define a therapeutic strategy. In 11 cases, facial, laryngeal or pharyngeal extension was observed, and 1 cas showed mediastinal extension. These cases are not easily treated, and it is impossible to perform complete surgery, thus leading to recurrence. Tracheotomy was necessary in two cases. In 5 cases, the extension was limited to the cervical area and surgical exeresis was considered complete. Sclerosing injections gave variable results.

[Obstructive sleep apnea-hypopnea syndromes in children. Therapeutic results]. / Syndrome d'apnées-hypopnées obstructives du sommeil chez l'enfant. Résultats thérapeutiques.

43 children with a clinical suspicion of obstructive sleep apnea-hypopnea were studied. All children underwent clinical examination and a standardised questionnaire was completed by their parents in order to investigate the principal nocturnal and diurnal symptoms present. A sleep study was performed. In addition to methods designed to identify the stage of sleep (EEG, EOG, EMG), this included recording of nasal and buccal airflow, thoracic and abdominal respiratory movements and blood gas analysis. 38 children has recordings during their afternoon nap, and 4 children during the night. Tonsillar hypertrophy was the principal etiology responsible for nocturnal respiratory disorders (33 cases). In addition, other etiologies were demonstrated: Pierre Robin syndrome, cranio-facial stenosis, laryngomalacia, Prader-Willi syndrome and Arnold Chiari malformation. Surgery was performed in 31 children: 22 tonsillectomies with or without adenoidectomy, 4 uvulo-palato-pharyngoplasties with tonsillectomy, 3 epiglottoplasties and 2 staphylorrhaphies. Long-term results were studied clinically and in 11 cases by polysomnographic recording.

[Cholesteatoma of the middle ear with closed tympanic membrane in children. Apropos of 8 cases]. / Cholestéatome de l'oreille moyenne à tympan fermé chez l'enfant. A propos de 8 observations.

Among 30 children with cholesteatoma undergoing surgery at the Bicetre Hospital between 1985 and 1990, 8 had intact tympanic membranes. Since this represents a larger portion of the patient population than would be expected from previously published data, we under-look a critical analysis of the clinical findings. Among these 8 cases, 2 corresponded to the criteria of congenital cholesteatoma with no history of otitis or trauma and 3 corresponded to acquired types with histories of ventilatory intubation, myringoplasty and accidental trauma. Finally, 3 cases were possibly of mixed origin with lesions typical of congenital epithelial rests and a history of commonplace era infections. Based on these observations, the authors review the clinical characteristics and pathogenesis of congenital cholesteatoma and evoke the etiologic impact of trauma, particularly iatrogenic events such as myringoplasty and ventilatory intubation.

[Contribution and role of the scanner in the preoperative evaluation of chronic otitis. Radiosurgical correlation apropos of 85 cases]. / Apport et place du scanner dans le bilan pré-opératoire de l'otite chronique. Corrélation radio-chirurgicale à propos de 85 cas.

High resolution computed tomography (CT) is today the best imaging to study chronic middle ear diseases. In a retrospective analysis of 85 chronic otitis media (cholesteatoma or not), the authors emphazise the diagnostic value of CT scan, its preoperative's role and the radiologic imaging of cholesteatoma. In our study, the radiosurgical correlation rate is 0.6 regarding positive diagnosis in chronic otitis or cholesteatoma. The malleus and incus analysis is correct, but stapes is not observed in 40% of cholesteatoma. The correlation of surgical and radiographic findings is excellent regarding the scutum, the horizontal semicircular canal (> 0.7), the tegmen (= 0.6), bad for the canal of facial nerve (< 0.5). The actual extent of chronic otitis media lesions is overestimated by CT scan in 70% of cases. The correlation's rate is reliable for epitympanum and aditus. To conclude, the preoperative CT is necessary in those cases: closed eardrum cholesteatoma, single functional ear, clinical complications and doubtful diagnosis.

[Osteoid osteoma of the middle ear. Review of the literature apropos of the first described case]. / Ostéome ostéoïde de la caisse du tympan. Revue de la littérature à propos du premier cas décrit.

The case of an osteoid osteoma of the middle ear in a 42 year old man is reported. No former case has now been reported in the literature for this localization. The suspected diagnosis of osteoid osteoma was based on the pain and the findings of bone computerize tomography. In our case, the osteoid osteoma was totally painless and the diagnosis was made after surgical findings by histological studies. Some clinical and imaging points, pathologic findings and differential diagnosis are also discussed.