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Biomedical subjects

S Bobin

Publications and source records attributed to S Bobin.

At least 19 recordsLinked to original sources

A prospective, multicentre study of moxifloxacin concentrations in the sinus mucosa tissue of patients undergoing elective surgery of the sinus.

A pharmacokinetic study was carried out to determine moxifloxacin concentrations in sinus tissue, after oral moxifloxacin 400 mg once daily for 5 days to patients with chronic sinusitis, undergoing elective sinus surgery. Patients were randomly allocated to one of seven treatment groups, in which tissues were sampled 2, 3, 4, 6, 12, 24 or 36 h post-dose. A control group with non-infected nasal polyps was also included. Forty-eight patients (13 female, 35 male, mean age 47.1 years) were allocated to one of each active treatment group (n = 42) or to the control group (n = 6). Tissue and plasma samples were taken simultaneously and stored frozen until assayed by HPLC. Thirty-nine patients were fully valid for pharmacokinetic analysis. The geometric mean moxifloxacin plasma concentration increased from 2.32 mg/L at 2 h to a maximum of 3.37 mg/L at 4 h post-dose, decreasing to 0.37 mg/L at 36 h post-dose. The moxifloxacin concentration in sinus mucosa was consistently greater than that in plasma being 4.56-5.73 mg/kg from 2 to 6 h and 2.81-1.25 mg/kg from 12 to 36 h post-dose. The elimination rates in plasma and sinus tissues were similar. The tissue/plasma ratio was c. 200% between 2 and 6 h, and up to 328.9% at 36 h. Results were similar whatever the site of tissue sampling (maxillary sinus, anterior ethmoid sinus or nasal polyps). Tissue levels exceeded the MIC(90) of all pathogens commonly causing acute sinusitis (e.g. 5-30 x MIC for Streptococcus pneumoniae: 0.25 mg/L). These results sup-port the use of moxifloxacin 400 mg once daily as a regimen for the treatment of sinus infections.

Adult↗

Full dose reirradiation combined with chemotherapy after salvage surgery in head and neck carcinoma.

BACKGROUND: The purpose of this study was to analyze the tolerance and efficacy of full dose reirradiation combined with chemotherapy in patients with head and neck carcinoma (HNC) with a high risk of recurrence after salvage surgery. METHODS: Between 1991 and 1996, 25 patients having a recurrence or a second primary tumor in a previously irradiated area (> 45 grays [Gy]) were entered in this prospective study. All of them received salvage surgery and had a positive surgical margin and/or lymph node involvement with capsular rupture (N+R+). Adjuvant radiochemotherapy was given, delivering 60 Gy per 30 fractions with concomitant hydroxyurea and 5-fluorouracil. The median total cumulative dose of the 2 irradiations was 118 Gy. The median follow-up after the second irradiation was 66 months. RESULTS: During the reirradiation course, Grade 3 and 4 mucositis were observed in 40% and 12%, respectively. Analysis of late effects (> 6 months after reirradiation) showed that 16% of the patients had osteoradionecrosis and 40% had Grade 2-3 cervical fibrosis (Radiation Therapy Oncology Group scoring system). The patterns of failure were as follows: local only (n = 9), lymph node only (n = 2), local and lymph node only (n = 1), and metastatic (n = 4). The 4-year survival rate after reirradiation was 43% (95% confidence interval, 25-62). CONCLUSIONS: Full dose reirradiation combined with chemotherapy after salvage surgery in high risk patients with HNC was feasible with an "acceptable" toxicity and led to a relatively good 5-year survival rate. These results prompted the authors to initiate a multicentric randomized trial that is ongoing (GETTEC-GORTEC 99-01) to evaluate the benefit of adjuvant radiochemotherapy in these types of patients.

Adenocarcinoma↗

Hemangioma of the porus acusticus. Impact of imaging studies: case reports.

Hemangiomas are tumors. Hemangiomas near the geniculate ganglion or in the internal acoustic meatus are well known but rare. We present two cases of hemangiomas located at the porus acusticus, an even more rare site. MRI showed a millimeter-sized tumor, located in the porus acusticus, developing perpendicular to the axis of the acoustico-facial nerves, surrounding them. They were hyperintense on T1-weighted images, strongly hyperintense on T2-weighted images with a characteristic progressive and marked enhancement after injection of gadolinium DTPA. Similar signal abnormalities were present in the adjacent temporal bone, and CT scan demonstrated a honeycomb appearance with intratumoral bony spicules. These imaging criteria allows differentiation between hemangioma and neurinoma. We hypothesize that this location is related to the presence of a rich vascular plexus of the dura mater in this area.

Adult↗

Approach to the determination of insulin-like-growth-factor-I (IGF-I) concentration in plasma by high-performance liquid chromatography-ion trap mass spectrometry: use of a deconvolution algorithm for the quantification of multiprotonated molecules in electrospray ionization.

The insulin-like-growth-factor-I (IGF-I) peptide is known to be a marker for growth hormone administration. The development of a quantification method by electrospray ionization mass spectrometry (ESI-MS) coupled with high-performance liquid chromatography (HPLC) is required. This paper describes a method to quantify IGF-I using the internal standard R3 IGF-I in its oxidized forms. A deconvolution software was used to quantify the set of multi-charged molecules recorded on an ESI ion trap mass spectrometer. The results (i.e., linearity, reproducibility and concentration range) were obtained on standard samples and the described LC-ESI-MS method should be applicable to biological samples.

Algorithms↗

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.

Age Factors↗

Isotonic mechanics of a pharyngeal dilator muscle and diaphragm in the rat before and after fatigue.

Pharyngeal and diaphragm muscles contract and relax in synergy, which is why it was decided to compare their mechanical performance throughout the overall load continuum. The effects of fatigue were also studied. The isotonic mechanics of rat sternohyoid (SH; n=10) and diaphragm (D; n=10) were investigated in vitro. Force and length were measured in muscles contracting from zero load up to isometry. Maximum isometric tension (Pmax), peak mechanical work (Wmax), maximum unloaded shortening velocity (vzL) and mechanical efficiency (eff(max)) were recorded. Data were obtained both at baseline and after fatigue. SH muscles had a lower Pmax (96.0+/-13.7 versus 119.5+/-22.7 mN x mm(-2); p<0.05), a lower Wmax (5.5+/-1.2 versus 8.0+/-2.1 mJ x g(-1); p<0.01), a lower eff(max) (56.0+/-6.9 versus 62.6+/-5.8%; p<0.05) and a higher vzL (4.8+/-0.4 versus 3.4+/-0.4 initial length (L0) x s(-1); p<0.001) than D muscles. Wmax occurred at a higher relative load in SH (40% Pmax) than in D (30% Pmax). Fatigue did not modify eff(max) in SH muscles, whereas it significantly improved eff(max) in D muscles. These findings suggest that under control conditions, economy of force generation was less efficient in sternohyoid than in diaphragm muscles. Fatigue in sternohyoid muscles induced unfavourable mechanical behaviour. This may partly explain pharyngeal dilator muscle failure in the presence of increased loads. Whether these findings are relevant to human sleep apnoea syndrome has yet to be determined.

Animals↗

Short therapy with amoxicillin-clavulanate and corticosteroids in acute sinusitis: results of a multicentre study in adults.

Evolution of bacterial resistance shortens antibiotic treatment in ENT infections. The efficacy and tolerance of amoxicillin-clavulanate (ACA), with and without associated short steroid therapy, was evaluated in acute sinusitis of adults at a dosage of 1.5 g/d for 5 d vs. 10 d. This multicentre, randomized, double-blind, placebo-controlled study included 433 patients, 417 of whom were suitable for intent-to-treat (ITT) analysis. The therapeutic success rate in the ITT population, assessed according to strict clinical and radiological criteria, was respectively, 80% and 85% in the 5-d and 10-d treatment groups. Due to the statistical risks that were evidenced, the 2 durations of treatment could not be considered equivalent. The analysis of medical history shows that some risk factors (recurrence of sinusitis, previous surgical sinus drainage) seem to promote therapeutic failure and that 5-d treatment is inappropriate in these patients. The persistence of therapeutic success on day 30 was not influenced by the initial duration of treatment. The efficacy and good tolerance of ACA in acute sinusitis in adults were confirmed. Further studies will be needed to define the indications of short treatments better, which seem to be indicated in the absence of specific risk factors.

Acute Disease↗

Severe mechanical dysfunction in pharyngeal muscle from adult mdx mice.

The mdx mouse is a widely used animal model of human muscular dystrophy. Although diaphragm muscle exhibits severe muscle weakness throughout the life of the animal, the limb muscle function of mdx mice spontaneously recovers by 6 mo of age. Pharyngeal dilator muscles such as sternohyoid (SH) contribute to upper airway patency during breathing. We hypothesized that SH muscle function was impaired in 6-mo-old mdx mice. Mechanical properties and myosin heavy chain (MHC) composition were investigated in isolated SH from 6-mo-old control (C, n = 10) and mdx (n = 10) mice. As compared with C, peak tetanic tension (Pmax) and maximum shortening velocity were 50% and 16% lower in mdx mice (p < 0.001 and p < 0.05, respectively). Peak mechanical power was lower in mdx than in C (19.0 +/- 3.2 versus 57.4 +/- 5.1 mW g(-)(1), p < 0.001). Both C and mdx SH were composed exclusively of fast myosin isoforms. As compared with C, mdx SH presented a higher proportion of IIX-MHC and a reduction in IIB-MHC (each p < 0.001). In conclusion, our results demonstrated severe SH muscle dysfunction in 6-mo-old mdx mice, that is, at a time when limb muscle function has recovered. Thus, SH muscle of the mdx mouse may be an excellent muscle for studying Duchenne muscular dystrophy.

Age Factors↗

[Short term evaluation of a new treatment method for primary snoring: radiofrequency energy].

The usual treatments for primary snoring are uvulopalatopharyngoplasty (UPPPP) and laser assisted uvulopalatoplasty, their morbidity is known, particularly considerable postoperative pain. We have performed a prospective study on a population of 23 patients with primary snoring (respiratory disturbance index =6 +/- 1) to 1) evaluates by means of questionnaires the short term (2 month) efficacy of the application of radiofrequency energy at the level of the soft palate, and 2) assess the morbidity associated with this treatment in this population. In the group of patients receiving treatment at three sites in a maximum of three sessions, the short term satisfaction rate was 75 %. The postoperative pain was of minor importance and the use of major analgesics was necessary in 2 cases only. We conclude that this treatment with radiofrequency energy seems to be an effective treatment for primary snoring at short term. The morbidity, specially the pain seems to be distinctly inferior compared to UPPP or laser treatment. Further prospective studies on a larger number of patients and with a longer follow-up are absolutely necessary to confirm these results.

Catheter Ablation↗

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.

Barium Radioisotopes↗

[The place of MRI in the study of cerebrospinal fluid fistulas].

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.

Adolescent↗

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.

Apnea↗

[Importance of antiproteases in the treatment of microsporidia and/or cryptosporidia infections in HIV-seropositive patients].

Diarrhea due to infection with Microsporidium (M) or Cryptosporidium (C) raises significant therapeutic challenges in HIV-infected patients. The usefulness of protease inhibitor therapy was evaluated in 20 HIV-positive patients with positive tests for M and/or C. There were 17 men and three women with a mean age of 42.5 years (range, 26-64 years). Two patients had category B disease and 18 category C disease according to the 1993 CDC classification scheme (CD4 count before therapy, 72/mm3; mean viral burden, 4.6 log). Seventeen patients had chronic diarrhea (due to M in 12 cases and to C in five), and the remaining three patients were asymptomatic M carriers. Clinical symptoms resolved after addition to the antiretroviral regimen of indinavir (n = 17) or saquinavir (n = 3). Mean weight gain was 10.5 kg. Karnofsky's index improved. Twelve patients, including one of the three who were asymptomatic at baseline, had negative follow-up stool cultures. The mean CD4 count increase was 125/mm3, and the mean viral burden decrease was 1.285 log. These data suggest that protease inhibitors may be capable of eradicating M and/or C infection refractory to other treatments. The reason for this effect may involve partial restoration of immune function due to inhibition of HIV replication.

AIDS-Related Opportunistic Infections↗