Genetic and molecular characterization of multicomponent resistance of Pseudomonas against allicin.

The common foodstuff garlic produces the potent antibiotic defense substance allicin after tissue damage. Allicin is a redox toxin that oxidizes glutathione and cellular proteins and makes garlic a highly hostile environment for non-adapted microbes. Genomic clones from a highly allicin-resistant Pseudomonas fluorescens (PfAR-1), which was isolated from garlic, conferred allicin resistance to Pseudomonas syringae and even to Escherichia coli Resistance-conferring genes had redox-related functions and were on core fragments from three similar genomic islands identified by sequencing and in silico analysis. Transposon mutagenesis and overexpression analyses revealed the contribution of individual candidate genes to allicin resistance. Taken together, our data define a multicomponent resistance mechanism against allicin in PfAR-1, achieved through horizontal gene transfer.

New insight into the bony labyrinth: a microcomputed tomography study.

OBJECTIVES: To visualize and quantify the morphology and mineralization of the developing fetal human bony labyrinth, using 3D-microcomputed tomography (3D-microCT) imaging. METHODS: Eleven right temporal bones from late second and third trimester fetuses were used in this prospective pilot study. After fixation in 10% formalin solution, all samples underwent a microcomputed tomography (microCT) scan, permitting the 3D imaging of the bony labyrinth as well as the quantitative assessment of mineral density, angular distances and dimensions of inner ear components the progression of ossification was precised with histological observations. RESULTS: Our findings show different rates of growth among the semicircular canals, the vestibular aqueduct, the oval window, the round window and the cochlea. The final sizes of the cochlea and round window are achieved at 23 weeks of gestation, with heights of 5mm and 2mm, respectively. The oval window reaches adult size at 35 weeks, whereas the vestibular aqueduct will attain adult size after birth. An increasing degree of torsion of each semicircular canal is observed during fetal development. The superior semicircular canal achieves adult size at 24 weeks, before the posterior and the lateral canals (25 weeks). The time-course of ossification and mineralization observed in structures and confirmed by histology. CONCLUSIONS: During this developmental period poorly studied until now, our findings suggest that each part of the bony labyrinth follows distinct growth and ossification kinetics trajectories, some of these reaching their adult size only after birth.

A comparison of the hearing results of KTP and Erbium YAG laser stapedotomy.

CONCLUSION: Our data prove that lasers are safe and useful instruments in stapes surgery. Good postoperative results can be attained in both KTP and Er: YAG lasers. There was no significant inner ear damage related to the Er: YAG laser use. OBJECTIVE: To compare the postoperative results of stapedotomies performed with KTP and Erbium: YAG lasers in patients with otosclerosis in order to assess the risk of Er: YAG for the inner ear. PATIENTS AND METHODS: The charts of 152 consecutive adult patients who underwent primary laser stapedotomies for otosclerosis from 1999 to 2005 were reviewed. One hundred and thirty-seven stapedotomies (98 patients) were performed using the KTP laser and 54 stapedotomies (54 patients) were performed with Er: YAG laser. All the patients were separated in two groups according to the type of laser, which was used. Hearing results were analyzed according to the Committee on Hearing and Equilibrium Guidelines of the American Academy of Otolaryngology-Head and Neck Surgery. Pure-tone audiometry was performed before the surgery, three months and one year postoperatively. RESULTS: The study indicated that KTP and Er: YAG stapedotomies have similar rates of the air-bone gap closure. There was no significant postoperative sensorineural hearing loss found in both techniques.

Surgical anatomy of the sphenopalatine foramen and its arterial content.

The sphenopalatine artery is the end artery of the maxillary artery located within the pterygopalatine fossa and passes through the sphenopalatine foramen (SPF) on lateral nasal wall. Nasal bleeding from this artery is potentially life threatening and may urgently require endonasal endoscopic occlusion. The aims of the present study have been first to investigate the location of the SPF, secondly the pattern of the main branches of the sphenopalatine artery at the foramen. 12 adult dry skulls and 6 adult cadaver heads injected within Indian Ink have been analyzed under an operating microscope Leica. All measurements were assessed using a digital calliper. The inferior border of the SPF has been situated 18.27 mm (15.09-20.87 mm) above the horizontal plate of the palatine bone and 13.04 mm (9.01-14.85 mm) above the horizontal lamina of the nasal inferior turbinate. Endoscopically, the posterior wall of the maxillary sinus is located at the level or anteriorly within 10 mm to the anterior border of the SPF. In all cases, the anterior border of the SPF is characterized by an easy recognizable sharp bony crest at the narrow middle part of the hourglass shape foramen. The SPF is 6.13 mm high (5.24-6.84 mm), with deep grooves extended superiorly and inferiorly from the foramen in eight skulls (8/12). The posterior lateral nasal artery which courses inferiorly and vertically (diameter 1.80+/-0.20 mm) and the nasal septal artery which courses superiorly and vertically (diameter 1.30+/-0.30 mm) have been the two major branches just leaving the SPF. One or two smaller collateral branches (diameter less than 1 mm) to the superior and/or the middle turbinate can get out coming from the stem of the main branches or directly from the SPF. So, the success rate of sphenopalatine artery ligation during endoscopic surgical procedure needs selective dissection of the two main branches of the sphenopalatine artery close to the SPF.

[Cellular, extracellular and histological analysis of the vocal folds: correlation between structure and function]. / Analyses cellulaire, extracellulaire et histologique des cordes vocales: corrélation entre structure et fonction.

The vocal folds, which are an important element of phonation, vibrate at the slightest sound. In order to provide a correct vibration, vocal folds have a complex histological structure which is continuously being unveiled thanks to the advancement of research techniques. Therefore, for about forty years, lots of works have permitted to define its qualitative and quantitative composition. Here, we are trying to make a synthesis of this literature, to point out how the histological structure of the vocal fold is used to produce a quality vibration. We used information acknowledged by most scientists, and other ones, more recent, developed thanks to new techniques of micro structural elements identification. These abundant information are, sometimes, in contradiction, given that lacunae are still numerous.

[Cochlear otosclerosis and pseudo fourth turn of the cochlea]. / Otospongiose cochléaire et pseudo-quatrième tour de cochlée.

OBJECTIVE: To describe different sequences on magnetic resonance imaging (MRI) in otosclerosis with peri-cochlear involvement. METHOD: MRI T1 and T2 sequences with T1 gadolinium injection and computed tomography (CT) scans with millimetric slices on axial and coronal views were obtained. The diagnosis of bilateral otosclerosis was confirmed by surgical exploration. RESULTS: On the CT scan, there was a fourth turn of the cochlea which appeared on the MRI T1 sequence with an intermediate signal and on the T2 sequences with a high intensity signal. After gadolinium injection, there was signal enhancement, suggestive of active otospongiosis. On the CT scan, there was another lesion in front of the cochlea with endosteal involvement. This was no however visible on the MRI, even after gadolinium infusion, in accordance with inactive otospongiosis. DISCUSSION: We reviewed the literature concerning MRI and results in otosclerosis. CONCLUSION: MRI of the labyrinth with T1 sequences and gadolinium injection can be contributive to the diagnosis of otosclerosis to differentiate inactive from inactive otospongiosis. However, prospective studies must be conducted to confirm this hypothesis.

[Failure of regain full function after surgery for otosclerosis: causes, diagnosis and treatment]. / Echecs fonctionnels dans la chirurgie de l'otospongiose: causes, diagnostic et traitement.

OBJECTIVE: The aim of this study was to evaluate the causes, the diagnosis, the treatment and the results obtained by revision surgery, in cases of stapedectomy failures. MATERIALS AND METHODS: Retrospective study of 50 recent cases operated on between January 1997 and December 2001. DIAGNOSIS OF THE FAILURE: All reoperated patients had clinical and audiological assessment; CT scan with virtual endoscopy. RESULTS: The mean time of onset of failure was 23 months. The mean preoperative air bone gap was 25.5 dB. Otoscopy revealed a retraction pocket caused by poor eustachian tube function in 9 cases. CT scan proved to be very effective at differentiating the cause of the failure. OPERATIVE FINDINGS: In 11 cases the prosthesis was too short, in 8 cases the prosthesis had migrated out of the hole of stapedotomy and in 6 cases the piston was fixed in the stapedotomy hole. A partial or complete lysis of the long process of the incus was frequently associated, but in 9 cases it was the only cause of the failure. In all the cases when the piston was displaced, the stapedotomy was found to be covered by a thin mucous membrane, avoiding labyrinthine fistula. In 3 cases, the failure was due to recurrent otosclerosis. In 5 cases the failure was due to a local anomaly at the level of the oval window niche, 2 cases of failure were due to a malleus ankylosis. In 5 cases fibrous adhesion was found between the incus and the mucosa of the promontory. In one case a reparative granuloma was found at the level of the oval window. TREATMENT: In cases of partial lysis of the long process of the incus, a new prosthesis was placed in a 0.4 mm diameter stapedotomy, performed using a KTP laser. A 0.4 mm diameter piston was extended 0.2 mm below stapedotomy to avoid a new extrusion. Indeed some prosthesis extrusion could be due to increased movements of the ossicular chain in cases of eustachian tube dysfunction. In cases of complete lysis of the long process of the incus, or in cases of a very short long process of the incus, a piston was put in the stapedotomy and attached to the malleus manubrium. The results of revision stapedotomy were favorable in the absence of associated fibrous tissue adhesion or local malformation. The air bone gap was found to be less than 10 dB in 40 cases and between 10 and 20 dB in 8 cases. An impairment of the air bone gap was found in 2 cases. No case of bone conduction impairment was found in this series.

[Nasal polyposis: quantification of the eosinophil and granulocyte infiltrates. Anatomo-clinical correlations]. / Polypose naso-sinusienne: quantification de l'infiltrat cellulaire granulocytaire et éosinophilique. Corrélations anatamo-cliniques.

OBJECTIVE: Prospective study designed to count the number of granulocytic cells and eosinophils in nasal polyp tissue removed during ethmoidectomy and to look for anatomical correlations. METHODS: Bilateral ethmoidectomy with a postoperative local steroid treatment was performed in 40 patients with nasal polyposis. Immunolabeling of the operative specimen using common leukocyte antigen (CD 45) and granulocytes associated antigen (CD 15) and quantification of the granulocyte infiltrate by image and manual counting of eosinophils with the mean of micro-reticule, were performed. The results were compared to those of 10 healthy subjects. An endoscopy of the postoperative cavities was performed one year after surgery to assess the local results. RESULTS: The granulocyte and eosinophil infiltrates were significantly more important in the operated patients compared to the healthy population (p<10(- 4)). A "moderate" granulocytic infiltration (G -) was found in 11 patients out of 40 (27.5%). Among them, 9 patients showed less than 30% eosinophils (mean 16.2% +/- 2%). "Severe" granulocytic infiltrate (G +) was found in 29 patients out of 40 (72.5%). Among them, 25 patients showed more than 30% eosinophils (mean 48.8% +/- 2%). Most of the patients with G + type infiltrate suffered from asthma or Widal disease. One year after surgery, 17 out of 29 G + patients had no nasal polyposis recurrence, 12 out of 29 G + patients had a recurrence. However, 12 out of 15 patients with recurrent polyposis had G + type infiltrate. CONCLUSIONS: Granulocyte and eosinophil infiltration cannot be considered as a prognostic factor for recurrence at the time of surgery. A severe granulocyte and eosinophil infiltration is a typical feature of nasal polyposis, particularly in patients with asthma and/or in the aspirin triad.

[Benign paroxysmal positional vertigo of the horizontal canal. Clinical features in 25 patients]. / Le vertige positionnel paroxystique bénin du canal horizontal.

OBJECTIVES: To review the clinical features of benign paroxysmal positional vertigo of the horizontal canal (HC-BPPV). PATIENTS AND METHODS: Retrospective study (September 1999 to March 2001) of 25 patients with HC-BPPV. Patients complained of positional vertigo associated with direction changing horizontal positional nystagmus, either geotropic or ageotropic. RESULTS: The horizontal nystagmus was triggered in all patients when rolled to either side in a supine position (head raised 30 degrees) and in 14 patients by the Dix Hallpike manoeuvre. The nystagmus was geotropic in 15 patients and ageotropic in 10. It varies in time in 4 patients with one change in 3 (from geotropic to ageotropic in 2 and ageotropic to geotropic in 1) and 4 changes in 10 days in another patient. In one patient with head trauma, the HC-BPPV was currently associated with ipsilateral posterior canal benign paroxysmal positional vertigo (PC-BPPV), and its characteristic rotatory-up beat nystagmus. Interestingly, 4 patients had a previous history of ipsilateral PC-BPPV and in 5 others an ipsilateral PC-BPPV occurred after the HC-BPPV. Although spontaneous recovery of HC-BPPV was common in most patients, a 270 degrees "barbecue rotation" or a "prolonged position on the healthy side" was effective in some patients. CONCLUSION: Patients with positional vertigo should undergo Dix Hallpike positioning and supine lateral head turns as this latter manoeuvre is more efficient to diagnose an HC-BPPV. Both the transformation of the positional horizontal nystagmus (geotropic-ageotropic) and the association with a PC-BPPV support the diagnosis of an HC-BPPV.