OMe

Distribution by Scientific Domains
Distribution within Chemistry


Selected Abstracts


Reassociation of fragments using multicentered multipolar expansions: peptide junction treatments to investigate electrostatic properties of proteins

JOURNAL OF COMPUTATIONAL CHEMISTRY, Issue 7 2001
L. E. Dardenne
Abstract We report an analysis of three schemes for fragment reassociation using multicentered multipolar expansions derived from ab initio quantum wave functions at the Hartree,Fock/6-31G* LCAO level, two of them involving single-bond partitioning in the peptide bond region, and the third one using a partially overlapping procedure based on a methodology proposed by Vigné-Maeder21 (OME,overlap of multipolar expansions,reassociation method). The effects of different peptide junction treatments in the derivation of molecular electrostatic potentials and molecular electric fields of three peptide sequences are discussed. The results show that the OME reassociation method gives a better and a more homogeneous description of both the potential and the electric field than the other two treatments. We conclude that the OME method is the most indicated for studies involving electrostatic properties of proteins. Our results also indicate that the use of multicentered multipolar expansions coupled to the OME treatment is the best choice in protein studies including solvent effects using, for example, a continuum boundary method to solve the linearized Poisson,Boltzmann equation. © 2001 John Wiley & Sons, Inc. J Comput Chem 22: 689,701, 2001 [source]


Alternative indications for laser-assisted tympanic membrane fenestration

LASERS IN SURGERY AND MEDICINE, Issue 4 2001
Steven P. Cook MD
Abstract Background and Objective To assess the utility of the CO2 Flashscanner laser for treatment of selected middle ear diseases other than otitis media with effusion (OME) and acute otitis media (AOM). Study Design/Materials and Methods A retrospective review of the records of 144 patients treated with the OtoLAM® device, a Flashscanner laser, between July 1, 1998, and February 29, 2000. Patients treated for AOM or OME were excluded. Results Data are presented on 11 patients (17 ears). Four indications were identified: Elimination of middle ear fluid before auditory brainstem response with or without otoacoustic emission testing (ABR,±,OAE), barotrauma, eustachian tube obstruction, tympanocentesis when a culture of middle ear fluid was deemed necessary. All tympanic membranes (TM) healed. Conclusions Fenestration of the TM can be accomplished for both diagnostic and therapeutic purposes. Laser assisted tympanic membrane fenestration seems to be effective in the management of middle ear fluid before ABR,±,OAE, barotrauma, eustachian tube dysfunction, and for tympanocentesis. Lasers Surg. Med. 28:320,323, 2001. © 2001 Wiley-Liss, Inc. [source]


IgE sensitization, respiratory allergy symptoms, and heritability independently increase the risk of otitis media with effusion

ALLERGY, Issue 3 2006
F. M. Chantzi
Background and aims:, Epidemiological evidence examining the role of atopy and/or allergy in the pathogenesis of otitis media with effusion (OME) is inconclusive. The aim of this study was to assess any increased risk for OME attributable to allergy-related factors, in a well-characterized population using a case-control design and multivariate analysis. Subjects and methods:, Eighty-eight 1,7-year-old children with OME, diagnosed by clinical and tympanometric evaluation and 80 matched controls were enrolled. A standardized questionnaire was completed, in order to assess factors related to OME and allergy-related symptoms and diagnoses using strict clinical definitions. Specific IgE was measured by skin-prick tests and/or CAP-FEIA. Results:, The patient and control groups were well matched. Factors conferring increased risk for OME in the univariate analysis included IgE sensitization, dyspnea, wheezing, asthma, paroxysmal sneezing, rhinitis, eczema, ,any allergic disease,' family history of otitis media, and family history of allergy. After multivariate analysis IgE sensitization, wheezing, nasal obstruction, family history of otitis, and child-care attendance remained as independent risk factors for development of OME. Conclusion:, IgE sensitization and respiratory allergy symptoms are independent risk factors for the development of OME, suggesting that both immunological and mechanical pathways may contribute to the development of the disease. Otitis heritability provides additional risk, as well as frequent exposure to viral upper respiratory tract infections in children attending daycare. Treatment and/or prevention of OME using anti-allergic medications should be further examined. [source]


The Treatment for Postirradiation Otitis Media With Effusion: A Study of Three Methods

THE LARYNGOSCOPE, Issue 11 2008
Yao-Dong Xu MD
Abstract Objective: To explore treatments for postirradiation otitis media with effusion (OME) in patients with nasopharyngeal carcinoma. Study Design: This study is a prospective quasi-randomized clinical trial. Methods: Ninety-six patients (135 ears) with OME after the first course of radiotherapy for nasopharyngeal carcinoma were divided into three groups: simple auripuncture plus aspiration, tympanic membrane fenestration with cauterization, and myringotomy plus grommet insertion. Cure rates and incidences of complications were compared. Results: Two deaths occurred. The other 94 patients (132 ears) finished a 2-year follow-up. In group 1, four ears (8.9%) were cured after the first treatment and 17 ears overall (37.8%) were cured by the end of the follow-up. Twenty ears (44.4%) had persistent fluid, two ears (4.4%) developed chronic suppurative otitis media, and five ears (11.1%) developed dry eardrum perforation. In group 2, seven ears (15.6%) were cured after the first treatment and 21 ears overall (46.7%) were cured by the end of the follow-up. Fourteen ears (31.1%) had persistent fluid, three ears (6.7%) developed chronic suppurative otitis media, and seven ears (15.6%) developed dry eardrum perforation. In group 3, eight ears (17.8%) were cured after the first treatment and 23 ears overall (51.1%) were cured by the end of the follow-up. Seven ears (15.6%) had persistent fluid, five ears (11.1%) developed chronic suppurative otitis media, three ears (6.7%) developed eardrum perforation with effusion, and five ears (11.1%) developed dry eardrum perforation. Conclusion: The methods each have advantages and disadvantages. We believe that a step by step approach should be used when choosing the treatment method for postirradiation OME. That is, first apply auripuncture plus aspiration, and then the other methods if this approach is inadequate. Enhanced local care after grommet insertion can effectively reduce the incidence of complications. [source]


Measurement of Angle and Length of the Eustachian Tube on Computed Tomography Using the Multiplanar Reconstruction Technique

THE LARYNGOSCOPE, Issue 7 2007
Kenji Takasaki MD
Abstract Objective: To compare the anatomic features of the eustachian tube (ET) between children with and without otitis media with effusion (OME) and with adults. Methods: The angle and length of the ET in children with OME (54 ears, OME children) and without OME (50 ears, normal children), as well as those of normal adults (90 ears), were measured on computed tomography using the multiplanar reconstruction technique. Results: The angles of ET in the OME children group, the normal children group, and the normal adult group were 20.4 ± 3.5° and 21.2 ± 4.8°, 19.9 ± 3.4° and 20.0 ± 3.6°, and 27.3 ± 2.7° and 27.3 ± 2.8° on the right and the left sides, respectively. There was no significant difference between the right and the left side in any group (P = .541, P = .952, P = .978). The lengths of ET in the OME children group, the normal children group, and the normal adult group were 37.2 ± 3.0 mm (mean ± SD) and 37.6 ± 3.2 mm, 37.5 ± 3.3 mm and 38.0 ± 3.2 mm, and 42.5 ± 2.8 mm and 42.9 ± 2.9 mm on the right and the left sides, respectively. There was no significant difference between the right and left sides in any group (P = .670, P = .597, and P = .545). Both the angles and lengths were significantly greater in the normal adult group than in either the OME children group or the normal children group (one-way analysis of variance and Fisher's protected least significant difference tests, P < .05), but there was no significant difference in either the angle or length of the ET between the OME and normal children groups (P > .05). In the OME and normal children groups, the angle was observed to constantly increase with age, and the values were found to be within the range of the adult size in all the patients older than 7.5 years and 7.7 years in the OME children group and the normal children group, respectively. As well as the angle, the lengths were observed to constantly increase with age, but the increase appeared to be greater at a younger age (until approximately 3 to 4 years) than at an older age, and the values were found to be within the range of the adult size in all the patients older than 6.8 years and 7.7 years in the OME children group and the normal children group, respectively. Conclusion: The angle and length of the ET are more horizontal and shorter in infants than in adults. However, there is no statistical difference between the angle and length of the ET in infants with and without OME. These results lead us to believe that a short and horizontal ET may not be a main etiologic factor related to high susceptibility to OME in infants and children. [source]


Effects of Ciprofloxacin-Dexamethasone on Myringotomy Wound Healing,

THE LARYNGOSCOPE, Issue 3 2007
Patricia A. Hebda PhD
Abstract Objective: To evaluate the effects of the ciprofloxacin-dexamethasone (CDX) combination ototopical treatment after myringotomy on tympanic membrane (TM) healing in ears with eustachian tube obstruction (ETO) and unobstructed ears. Study Design: Prospective, randomized, masked, controlled. Methods: ETO was created in the left ear of 30 rats to induce a model of otitis media with effusion (OME). After 3 weeks, bilateral myringotomy was performed (day 0). Animals were randomized into three groups to receive no treatment or bilateral once daily ototopical treatment with balanced salt solution (BSS, vehicle) or CDX for 13 days. Bilateral otomicroscopy was performed on days 7, 14, and 28. On day 14, five randomly selected animals per group were humanely euthanized and the TM harvested for histology. Three additional rats provided normal negative control ears for histologic comparisons. Results: On day 14, TM perforation healing rates were 100% in all ears of untreated and BSS-treated animals, 89% (8/9) in CDX-treated obstructed ears, and 30% (3/10) in CDX-treated unobstructed ears (P < .05 vs. BSS). On day 28, 100% (5/5) of the CDX-treated unobstructed ears and 80% (4/5) of the CDX-treated obstructed ears were healed. Histology showed initial TM thickening postmyringotomy in all ears but no significant qualitative differences between groups on day 28. Conclusion: Myringotomy healing was transiently modulated by treatment with CDX but proceeded normally after CDX discontinuation. This early modulation might enhance middle ear drainage and middle ear concentrations of CDX when tympanostomy tube surgery is performed in patients with active OME and ETO, thus potentially reducing otorrhea and preventing or treating infection. It would not be expected to increase the risk of premature tube extrusion or adversely affect normal healing of the TM after usual spontaneous extrusion. [source]


Effect of Inhibitor of Tumor Necrosis Factor-, and Oxatomide on Immune Mediated Otitis Media

THE LARYNGOSCOPE, Issue 9 2006
Yong-Soo Park MD
Abstract Objective: Inflammatory mediators (IMs) play a major role in the production of middle ear effusion (MEE). Tumor necrosis factor (TNF)-, and leukotrienes (LTs) appear to be important in the pathogenesis of otitis media with effusion (OME). The purpose of this study is to determine the effect of TNF-, and LT antagonist on the outcome of experimental immune-mediated OME. Study Design: Prospective. Methods: Otitis media was induced in rats by injecting keyhole limpet hemocyanin (KLH) transtympanically 7 days after systemic immunization. Experimental groups were treated with soluble TNF receptor type I (sTNF RI) or oxatomide simultaneously. Seventy-two hours after transtympanic injection, MEE was aspirated, and temporal bone was taken. Vascular permeability (VP) of the middle ear mucosa was measured using the Evans blue dye technique. Hematoxylin-eosin stain and immunohistochemical stain for leukocyte common antigen was performed. Results: In KLH, sTNF RI, and oxatomide groups, MEE was developed in 83%, 0%, and 66% of the ears, respectively. The sTNF RI group showed significant decrease in effusion production, inflammation, mucosal thickening, and VP compared with the KLH group. These parameters were less significant in the oxatomide group than in the sTNF RI group. Conclusion: Transtympanic administration of sTNF RI and oxatomide appears to suppress the development of immune-mediated MEE. [source]


Detection of Helicobacter pylori in Children with Otitis Media with Effusion: A Preliminary Report

THE LARYNGOSCOPE, Issue 7 2005
Turgut Karlidag MD
Abstract Objective: To determine the presence of Helicobacter pylori in the middle ear effusion of patients with otitis media with effusion (OME) by polymerase chain reaction (PCR). Study Design: A prospective study in patients with OME. Methods: The study was performed in 38 patients with OME who were admitted to the ENT Clinic, Firat University from June 2003 to April 2004. In all cases, a myringotomy operation (with or without placement of a ventilation tube) was carried out. The effusion samples aspirated from the middle ear were analyzed with PCR assay. Results: A total of 55 aspiration samples collected from 38 children ranging in age from 2 to 12 were included in the study. Fifteen of the subjects were girls, and 23 were boys. In 17 patients, both ears demonstrated effusions, whereas in 21 patients, only one ear had effusions. Nine (16.3%) of 55 the middle ear effusion samples were shown to be H. pylori positive by PCR. Conclusions:H. pylori was detected in the middle ear effusion of some patients with OME. These results may have interesting implications for a possible role of H. pylori in OME. In addition, these results suggest that further studies are needed to investigate the role of H. pylori in the etiology of OME. [source]


Ventilation Time of the Middle Ear in Otitis Media With Effusion (OME) After CO2 Laser Myringotomy

THE LARYNGOSCOPE, Issue 4 2002
Benedikt Sedlmaier MD
Abstract Objective The aim of this study was to investigate the transtympanic ventilation time, the healing course of the tympanic membrane, the early and late complications, and the recurrence rate of otitis media with effusion (OME) within 6 months after CO2 laser myringotomy with the CO2 laser otoscope Otoscan. Study Design Prospective clinical study. Materials and Methods In this study, laser myringotomy was performed with the CO2 laser otoscope Otoscan in a patient population comprising 81 children (159 ears) with a history of otitis media with effusion (OME) associated with adenoidal and sometimes tonsillar hyperplasia. The procedure on the tympanic membrane was accordingly combined with an adenoidectomy, a CO2 laser tonsillotomy, or a tonsillectomy and therefore performed under insufflation anesthesia. In all ears, approximately 2 mm circular perforations were created in the lower anterior quadrants with a power of 12 to 15 W, a pulse duration of 180 msec, and a scanned area of 2.2 mm in diameter. Results None of the children showed postoperative impairment of cochleovestibular function such as sensorineural hearing loss or nystagmus. Otomicroscopic and videoendoscopic monitoring documented the closure time and healing pattern of tympanic membrane perforations. The mean closure time was found to be 16.35 days (minimum, 8 days; maximum, 34 days). As a rule, an onion-skin-like membrane of keratinized material was seen in the former myringotomy perforations at the time of closure. At the follow-up 6 months later, the condition of the tympanic membrane of 129 ears (81.1%) could be checked by otomicroscopy and videoendoscopy and the hearing ability by audiometry and tympanometry. The CO2 laser myringotomy sites appeared normal and irritation-free. Two of the tympanic membranes examined (1.6%) showed atrophic scar formation, and 1 (0.8%) had a perforation with a diameter of 0.3 mm. The perforation was seen closed in a control otoscopy 15 months postoperatively. OME recurred in 26.3% of the ears seen intraoperatively with mucous secretion (n = 38) and in 13.5% of the ears with serous secretion (n = 37;P <.05). Conclusion The most important principle in treating OME is ventilation of the tympanic cavity. CO2 laser myringotomy achieves this through a self-healing perforation in which its diameter roughly determines the duration of transtympanic ventilation. Laser myringotomy competes with ventilation tube insertion in the treatment of OME. It may be a useful alternative in the surgical management of secretory otitis media. [source]


Candidate's Thesis: Direct Evidence of Bacterial Biofilms in Otitis Media,

THE LARYNGOSCOPE, Issue 12 2001
J. Christopher Post MD
Abstract Objectives/Hypothesis Bacteriologic studies of otitis media with effusion (OME) using highly sensitive techniques of molecular biology such as the polymerase chain reaction have demonstrated that traditional culturing methods are inadequate to detect many viable bacteria present in OME. The presence of pathogens attached to the middle-ear mucosa as a bacterial biofilm, rather than as free-floating organisms in a middle-ear effusion, has previously been suggested to explain these observations. The suggestion has been speculative, however, because no visual evidence of such biofilms on middle-ear mucosa has heretofore been collected. The hypotheses motivating the current study were: 1) biofilms of nontypable Hemophilus influenzae will form on the middle-ear mucosa of chinchillas in an experimental model of OME, 2) these biofilms will exhibit changes in density or structure over time, and 3) biofilms are also present on tympanostomy tubes in children with refractory post-tympanostomy otorrhea. The objective of this study was to collect visual evidence of the formation of bacterial biofilms in these situations. Study Design Laboratory study of bacteriology in an animal model and on medical devices removed from pediatric patients. Methods Experimental otitis media was induced in chinchillas by transbullar injection of nontypable H. influenzae. Animals were killed in a time series and the surface of the middle-ear mucosa was examined by scanning electron microscopy (SEM) for the presence of bacterial biofilms. Adult and fetal chinchilla uninfected controls were similarly examined for comparison. In addition, tympanostomy tubes that had been placed in children's ears to treat OME and removed after onset of refractory otorrhea or other problems were examined by SEM and by confocal scanning laser microscopy for bacterial biofilms, and compared with unused control tubes. Results Bacterial biofilms were visually detected by SEM on the middle-ear mucosa of multiple chinchillas in which H. influenzae otitis media had been induced. Qualitative evaluation indicated that the density and thickness of the biofilm might increase until at least 96 hours after injection. The appearance of the middle-ear mucosa of experimental animals contrasted with that of uninjected control animals. Robust bacterial biofilms were also visually detected on tympanostomy tubes removed from children's ears for clinical reasons, in contrast with unused control tubes. Conclusions Bacterial biofilms form on the middle-ear mucosa of chinchillas in experimentally induced H. influenzae otitis media and can form on tympanostomy tubes placed in children's ears. Such biofilms can be directly observed by microscopy. These results reinforce the hypothesis that the bacterial aggregates called biofilms, resistant to treatment by antibiotics and to detection by standard culture techniques, may play a major etiologic role in OME and in one of its frequent complications, post-tympanostomy otorrhea. [source]


Quantitative Analysis of Tympanic Membrane Disease Using Video-Otoscopy ,

THE LARYNGOSCOPE, Issue 10 2000
Vikram J. Jaisinghani MD
Abstract Objective To perform quantitative analysis of pathological changes in the tympanic membrane using video-otoscopic images. Study Design Prospective case-control study. Methods Forty-two ears of children with chronic otitis media with effusion (OME) and 15 ears of normal children were included in this study. Tympanic membrane images were captured and digitized using a Welch-Allyn (Skaneatales Falls, NY) VDX-300 Illumination and Imaging system with S-VHS input to a MIRO DC 30 (Pinnacle Systems, Mountain View, CA) visual board in a Power PC,based computer. These images were visualized and recorded during static and pneumatic pressure changes. Quantitative analysis of tympanic membrane disease was performed using Image Pro Plus Imaging software (Media Cybernetics, Del Mar, CA). The measurements included area of the tympanic membrane and its quadrants, area of tympanic membrane involved by disease, angle formed at the umbo, and length of the malleus versus vertical length of the tympanic membrane. Results Tympanosclerosis was present in 57% of ears and occurred most frequently in the anteroinferior quadrant, but the ma-imum area of involvement was in the posteroinferior quadrant. The ratio of the angles formed at the umbo was significantly greater (P = .01) for the OME group compared with the control group. The ratio of the length of the umbo and the vertical length of the tympanic membrane was almost identical for the OME and the control groups (P = .4). Conclusions Video-otoscopic images can be used for quantitative analysis of tympanic membrane disease. The ratio of the posterior angle to the anterior angle formed at the umbo seems to be a more reliable indicator of post otitis media than is a reduced length of the long process of malleus. [source]


Adenoidectomy With Laser or Incisional Myringotomy for Otitis Media With Effusion,

THE LARYNGOSCOPE, Issue 3 2000
Wasyl Szeremeta MD
Abstract Objective To compare the effectiveness of CO2 laser myringotomy to incisional myringotomy at the time of adenoidectomy for refractory otitis media with effusion (OME). Study Design Controlled retrospective consecutive case series. Methods All children undergoing myringotomy and adenoidectomy for OME in the spring of 1999 had 1.7-mm-diameter perforations created in their tympanic membranes using a CO2 laser and conventional microslad. Their ears were evaluated at first postoperative visit (mean, 16.65 days after surgery) by a validated otoscopist to determine the presence or absence of perforations and middle ear effusions. These patients were compared with historical controls comprising all children undergoing incisional myringotomy and adenoidectomy in 1998. A ,2 analysis was performed to compare the results of these two myringotomy techniques. Results Twenty-three children (39 ears) underwent laser myringotomy and adenoidectomy in 1999, compared with 26 children (48 ears) who underwent incisional myringotomy and adenoidectomy in 1998. In the laser myringotomy group, 8 of the 39 ears had a persistent opening at first follow-up; 4 of the 39 ears showed evidence of effusion. In the incisional myringotomy group, all 48 ears had healed; 7 of these ears showed evidence of effusion. Conclusion Myringotomies created using the CO2 laser are more likely to be patent at first postoperative visit than those made with incisional technique (P < .01). However, this prolonged middle ear ventilation does not significantly decrease the prevalence of effusion (P > .1). [source]


Should children be screened to undergo early treatment for otitis media with effusion?

CHILD: CARE, HEALTH AND DEVELOPMENT, Issue 6 2003
A systematic review of randomized trials
Abstract Background Otitis media with effusion (OME) is the most common cause of acquired hearing loss in childhood and has been associated with delayed language development and behavioural problems. Some have argued that children should be screened and treated early if found to have clinically important OME. The aim of this review was to assess evidence from randomized controlled trials about the effectiveness of screening and treating children with clinically important OME in the first 4 years of their life. The primary outcome was language development. Methods We searched the Cochrane Controlled Trials Register, MEDLINE and EMBASE and reference lists of all included studies in February 2003. We also contacted the first authors of the studies included in this review. Search terms included otitis media; otitis media with effusion; glue ear; OME; screen; children; treatment; language; and behaviour. Data extraction and methodological quality assessment were performed by at least two of us for each study independently, using methods described in the Cochrane Collaboration Handbook. Results From the three included randomized controlled trials evaluating interventions among children with OME identified through screening, we found no evidence of clinically important benefit in language development. Conclusions The identified randomized trials do not show an important benefit on language development from screening the general population of asymptomatic children in the first 4 years of life to undergo early treatment for OME. Screening asymptomatic children in the first 4 years of life for OME is not recommended. [source]


The role of allergic rhinitis in upper respiratory tract inflammatory diseases

CLINICAL & EXPERIMENTAL ALLERGY REVIEWS, Issue 1 2004
Y. Kurono
Summary The number of patients with allergic rhinitis (AR) is increasing. Furthermore, patients with otitis media with effusion (OME) and chronic sinusitis (CS) are frequently complicated with AR. These findings suggest that AR has an impact on the pathogenesis of both OME and CS. The direct and indirect influence of AR on OME and CS was investigated by clinical and experimental studies to clarify the mechanism by which type I allergic reaction is associated with OME and CS. Clinical findings of patients with OME or CS complicated with AR were analysed and compared with those of nonallergic subjects. Samples such as sinus effusions and middle ear effusions (MEE) were collected from the patients and infiltration of inflammatory cells and concentrations of inflammatory cytokines determined. In addition, previous reports discussing the relationship between AR and OME or CS are reviewed. Eosinophil infiltration and oedema were remarkable in paranasal sinus mucosa of patients with CS complicated with AR, suggesting the presence of type I allergic reaction in sinus mucosa. However, there was little evidence of eosinophils in sinus effusions. Endotoxin was frequently detected in sinus effusions of patients with CS having AR as well as suppurative CS. Hypoxia was also considered an important factor inducing sinus pathology. Eosinophils and IgE antibodies in MEE were not increased in OME patients with AR. Anti-allergic medicine was effective in OME patients complicated with AR and improvement of nasal symptoms significantly correlated with that of ear symptoms. AR might be directly and indirectly associated with the pathogenesis of OME and CS. [source]


Developmental outcomes in early compared with delayed surgery for glue ear up to age 7 years: a randomised controlled trial

CLINICAL OTOLARYNGOLOGY, Issue 1 2009
A.J. Hall
Objectives:, To investigate whether early versus delayed surgery for children severely affected by otitis media with effusion (OME) results in improved performance on developmental tests up to age 7 years. Design:, Follow-up of a randomised controlled trial. Setting:, University of Bristol. Participants:, One hundred and eighty-two children (mean age 35 months) with persistent OME, hearing loss and speech, language or behaviour problems who were originally eligible and randomised to either early surgery or delayed surgery after a period of watchful waiting were followed-up as part of the Avon Longitudinal Study of Parents and Children (ALSPAC) at age 4½ and 7,8 years. Main outcome measures:, Measures included behaviour, language, educational attainment tests, hearing, reading, cognition and coordination. Results:, Of the original randomised trial, 88 of 92 of the early surgery and 74 of 90 of the watchful waiting group were still participating in ALSPAC. Analysis was by intention to treat. At age 4 ½ years there were significant differences in teacher assessment of language (adj OR 3.45, 95% CI: 1.42,8.39) and writing (adj OR 3.74, 95% CI: 1.51,9.27), in favour of early surgery. At age 7,8 years, there was a significant difference on teacher report of emotional problems (adj OR 4.11, 95% CI: 1.15,14.64) in favour of early surgery. There were no other significant differences. Conclusions:, Early surgery for the child severely affected by OME may be associated with subtle benefits at age 4½ years. This may continue to 7,8 years but the small study size makes it difficult to distinguish these effects from chance. A larger study is recommended. [source]


Value of post-nasal space biopsy in patients with adult onset serous otitis media

CLINICAL OTOLARYNGOLOGY, Issue 3 2006
A.H. Sadr
Background. Otitis media with effusion (OME) is common in children but this is not the case in adults. In adults it can be associated with nasopharyngeal neoplasms (NPN). It is accepted practice in the UK to biopsy the posterior nasal space (PNS) to rule out neoplasms. We believe this routine practice is no longer justified in view of modern methods of examination of PNS. Aims and objectives. To identify the incidence of NPN in adults with otitis media with effusion without any other signs and symptoms suggestive of NPN. We also identified the presenting symptoms and signs of all patients who were diagnosed with NPN during the study period. Methods. This is a retrospective study of 158 adult onset otitis media who had a posterior nasal space biopsy performed. The patients with positive and negative biopsy results were analysed for their presenting signs and symptoms. Results. Only 58 patients had OME as the sole presentation. The rest had other signs or symptoms in addition to OME. All patients with OME as the sole presentation had negative biopsy results and all patients with a positive biopsy result for NPN had other symptoms or signs in addition to OME. Conclusions. The role of PNS biopsy in adults with isolated OME seems to be questionable in view of the limited information it provides. This may be due to wider use of endoscopes which enable us to detect small abnormalities in PNS. [source]


How we do it: Laser reduction of peri-tubal adenoids in selected patients with otitis media with effusion

CLINICAL OTOLARYNGOLOGY, Issue 1 2006
W. Smith
Keypoints ,,The literature supports the benefit of adenoidectomy in patients with otitis media with effusion (OME). ,,It is difficult to clear adenoid tissue from around the Eustachian tubes using curettes and this conventional method of adenoidectomy is contra-indicated in patients with cleft palates. ,,Laser reduction of peri-Eustachian adenoid tissue without myringotomies or grommet insertion was performed in three patients with OME. Two patients had previous adenoidectomies performed with curettes and one patient had a cleft palate. ,,In all three patients, the OME resolved and all had closure of the air-bone gap that was maintained during long-term follow-up (14 months,4 years). ,,This technique resolved OME without the need for myringotomies or grommet insertion and should be considered particularly in patients who have peri-tubal recurrence of adenoidal tissue following conventional adenoidectomy or in patients with cleft palate where there is concern with regards to palatal incompetence. [source]


Sequelae of otitis media with effusion among children with cleft lip and/or cleft palate1

CLINICAL OTOLARYNGOLOGY, Issue 6 2002
P. Sheahan
Otitis media with effusion (OME) is common among children with cleft palate, and may lead to such long-term consequences as hearing loss, tympanic membrane retraction, and chronic otitis media (COM). In total, 104 children with cleft lip and/or palate treated for OME at our institution were reviewed. Mean duration of follow-up was 6.9 years, and mean age at latest follow-up was 9.6 years. The incidence of COM was 19%, and the incidence of cholesteatoma was 1.9%. Ears showing such long-term sequelae of OME as hearing loss, tympanic membrane retraction, and chronic otitis media, were noted to have undergone a significantly greater number of ventilation tube insertions than ears not showing these sequalae. Our findings would suggest that a conservative approach to the management of OME in children with cleft palate is more likely to be beneficial in the long term. [source]


Matrix metalloproteinases 2 and 9 in otitis media with effusion

CLINICAL OTOLARYNGOLOGY, Issue 6 2001
C.R. Jennings
Matrix metalloproteinases 2 and 9 in otitis media with effusion A qualitative and quantitative study of the presence of matrix metalloproteinase 2 (MMP 2) and matrix metalloproteinase 9 (MMP 9), in the effusions of otitis media with effusion (OME), was performed. The activity of the above enzymes was compared in thick and thin effusions, and concentrations compared in samples from children with one, two, three and four sets of ventilation tubes. The activity of both MMP 2 and MMP 9 was higher in thick than thin effusions, P = 0.07 and P = 0.04, respectively. The concentrations of MMP 9 did not vary with the number of tube insertions but those of MMP 2 did (ANOVA P < 0.05). MMPs may be involved in tympanic membrane damage and prognosis of OME. [source]


A Family of 1,1,3,3-Tetraalkylguanidine (H-TAG) Solvated Zinc Aryloxide Precatalysts for the Ring-Opening Polymerization of rac -Lactide

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 9 2010
Julia J. Ng
Abstract Reaction of [Zn(,-TAG){N(SiMe3)2}]2 {TAG = N=C[N(CH2CH3)2N(CH3)2] (DEDMG), N=C{[NCH2CH2CH2CdH2(N,Cd)]N(CH2CH3)2} (DEPYRG) and N=C{[NCH2CH2CH2CH2CeH2(N,Ce)]N(CH2CH3)2} (DEPIPG)} with 2 equiv. of ethanol (EtOH) and 2 equiv. of HOAr {OAr = OC6H3(CMe3)-2-(CH3)-6 (BMP) or OC6H2[C(CH3)3]2 -2,6-(CH3)-4 (4MeDBP)} results in dizinc alkoxides with the general formula [Zn(,-OEt)(OAr)(H-TAG)]2 (1,3). Et2Zn was additionally treated with 2 equiv. of 1,1,3,3-tetramethylguanidine (H-TMG) and H-BMP or HOC6H3(C6H5)2 -2,6 to yield [Zn(BMP)2(H-TMG)2] (4) and [Zn{OC6H3(C6H5)2 -2,6}2(H-TMG)2] (5). Complexes 1, 2, 4, and 5 were characterized by single-crystal X-ray diffraction. Polymerization of rac -lactide with 1,5 and [Zn(,-OMe)(4MeDBP)(H-TMG)]2 (6) were found to generate polylactide (PLA). The bulk powders for all complexes were found to be in agreement with the crystal structures based on elemental analyses, FTIR spectroscopy, and 1H and 13C NMR spectroscopic studies. [source]


Hydrido-Osmium(II), -Osmium(IV) and-Osmium(VI) Complexes with Functionalized Phosphanes as Ligands,

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 35 2009
Birgit Richter
Abstract Reaction of five-coordinate [OsHCl(CO)(PiPr3)2] (1) with the chelating phosphane iPr2PCH2CO2Me gave six-coordinate [OsHCl(CO)(PiPr3){,2(P,O)- iPr2PCH2C(=O)OMe}] (2), which upon treatment with CO and O2 afforded the 1:1 adducts [OsHCl(CO)(L)(PiPr3){,(P)- iPr2PCH2CO2Me}] (3, 4) by partial opening of the chelate ring. The vinyl complex [OsCl(CH=CHPh)(CO)(PiPr3){,2(P,O)- iPr2PCH2C(=O)OMe}] (5) was obtained from 2 and PhC,CH by insertion of the alkyne into the Os,H bond. Reaction of 2 with sodium acetate led to metathesis of the anionic ligands and formation of [OsH(,2 -O2CCH3)(CO)(PiPr3){,(P)- iPr2PCH2CO2Me}] (6). Osmium(VI) compounds [OsH6(PiPr2R)2] with R = CH2CH2OMe (12), CH2CO2Me (13) and CH2CO2Et (14), and [OsH6(PiPr3){,(P)- iPr2PCH2CH2NMe2}] (16) were prepared from osmium(IV) precursors and shown to rapidly react with O2 and primary alcohols. Exploratory studies revealed that the catalytic activity of the hexahydrido complexes in the hydrogen transfer reaction from 2-propanol to cyclohexanone and acetophenone depends on the type of the functionalized phosphane and is best for R = CH2CH2OMe. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source]


Bis(terdentate) Pyrazole/Pyridine Ligands: Synthesis, Crystal Structures and Magnetic Properties of Bridged Binuclear and Tetranuclear Copper(II) Complexes

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 23 2009
Akhilesh Kumar Singh
Abstract A new binucleating bis(terdentate) ligand, 3,5-[3-bis(2-pyridyl)pyrazole-1-ylmethyl]pyrazole (HL2), was synthesized. Reaction of the deprotonated ligand L2 with hydrated CuII salts gives (,-pyrazolato)(,-hydroxido)-bridged binuclear and tetranuclear complexes [L2Cu2(,-OH)(ClO4)(MeCN)](ClO4) (2), [L2Cu2(dmf)2(,3 -OH)]2(ClO4)4·4dmf (3·4dmf) and [L2L,Cu2](ClO4)2 [4; HL, = 3-(2-pyridyl)pyrazole]. In these complexes, both ,-OH and ,3 -OH bridges were observed. This contrasts the situation for a dicopper(II) complex of the related bis(terdentate) ligand 3,5-bis[6(2,2,-dipyridyl)]pyrazole (HL1), {L1Cu2(OMe)(MeOH)[,1 - O -(NO3)]}{[Cu2(NO3)2(,-OMe)2]}0.5·MeOH (1·MeOH), where the shorter and more rigid ligand side arms enforce a larger Cu···Cu separation and the formation of a MeO,HOMe moiety within the bimetallic pocket. Molecular structures of all complexes were elucidated by X-ray crystallography. Variable-temperature magnetic susceptibility measurements (295,2 K) for powdered samples of complexes 2,4 reveal strong antiferromagnetic coupling between two copper centres. The magnitude of the coupling is discussed in view of the structural features. During the preparation of complex 4, partial ligand hydrolysis was also observed, but this strongly depends on the reaction conditions.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source]


Nickel Complexes of N/O -Functionalized N-Heterocyclic Carbenes as Precatalysts for Michael Reactions in Air at Room Temperature Under the Much Preferred Base-Free Conditions

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 13 2009
Sriparna Ray
Abstract A series of several new nickel precatalysts supported overN/O -functionalized N-heterocyclic carbenes (NHC) for the Michael reactions of ,-dicarbonyl, ,-keto ester, ,-diester, and ,-cyano ester compounds with ,,,-unsaturated carbonyl compounds in air at ambient temperature under the much preferred base-free conditions are reported. Specifically, the nickel complexes, [1-(R1 -aminocarbonylmethyl)-3-R2 -imidazol-2-ylidene]2Ni [R1 = 2-C6H4(OMe); R2 = Me (1b), iPr (2b), CH2Ph (3b) and R1 = 2-CH2C4H3O; R2 = Me (4b), CH2Ph (5b)] carried out the highly convenient base-free Michael addition of the activated C,H compounds across ,,,-unsaturated carbonyl compounds in air at room temperature. The complexes 1b,5b were synthesized by the direct reaction of the respective imidazolium chloride salt with NiCl2·6H2O in CH3CN in the presence of K2CO3 as a base. The exceptional stability of 1b,5b has been attributed to the deeply buried nickel,NHC ,-bonding molecular orbitals as evidenced from the density functional theory (DFT) studies. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source]


Fluoride-Free Hiyama and Copper- and Amine-Free Sonogashira Coupling in Air in a Mixed Aqueous Medium by a Series of PEPPSI-Themed Precatalysts,

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 12 2009
Chandrakanta Dash
Abstract A new series of robust, user-friendly, and highly active PEPPSI-themed (pyridine-enhanced precatalyst preparation, stabilization and initiation) (NHC)PdX2(pyridine)-type (X = Cl, Br) precatalysts of C4,C5 saturated imidazole- (1,4) and triazole-based (5 and 6) N-heterocyclic carbenes for the Hiyama and Sonogashira couplings under amenable conditions are reported. Specifically 1,6 efficiently catalyze the fluoride-free Hiyama coupling of aryl halides with PhSi(OMe)3 and CH2=CHSi(OMe)3 in air in the presence of NaOH as a base in a mixed aqueous medium (dioxane/H2O, 2:1 v/v). Along the same lines, these 1,6 precatalysts also promote the Cu-free and amine-free Sonogashira coupling of aryl bromides and iodides with phenylacetylene in air and in a mixed aqueous medium (DMF/H2O, 3/1 v/v). The complexes 1,6 were synthesized by the direct reaction of the respective imidazolinium and triazolium halide salts with PdCl2 in pyridine in the presence of K2CO3 as a base. DFT studies on the catalytically relevant palladium(0) (NHC)Pd(pyridine) precursors 1a,6a reveal significant donation from the N-heterocyclic carbene lone pair onto the unfilled ,* orbital of the trans Pd,pyridine bond. This weakens the Pd-bound "throwaway" pyridine ligand, and its dissociation marks the initiation of the catalytic cycle.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source]


Bis(acetylido) Complexes of Ruthenium(II) Bearing Monodentate Phosphane Ligands

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 27 2008
Leslie D. Field
Abstract Terminal acetylenes react with cis -RuMe2(PMe3)4 to form the bis(acetylido) complexes cis/trans -Ru(C,CR)2(PMe3)4 in good yield. The structures of trans - 2 (R = Ph), cis - 3 (R = p -C6H4 -OMe), trans - 4 (R = p -C6H4 -Me), cis - 6 (R = Me), trans - 7 (R = SiMe3) and cis - 8 (R = H) were determined by X-ray crystallography. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source]


Synthesis and Reactivity of Oxametallacyclic Niobium Compounds by Using ,,,-Unsaturated Carbonyl Ligands,

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 14 2008
Rocío A. Arteaga-Müller
Abstract Reduction of mono(cyclopentadienyl)niobium complexes [NbCpRCl4] [CpR = C5Me4H (1), C5H4SiMe2Cl (2), C5H4SiMe3 (3)] with Na/Hg in the presence of methyl methacrylate [MMA, CH2=C(Me)C(O)OMe (a)], methyl acrylate [MA, CH2=CHC(O)OMe (b)] and mesityl oxide [MO, CMe2=CHC(O)Me (c)] afforded the corresponding derivatives [NbCpRCl2(LL)] [CpR = C5Me4H, LL = MMA (1a); CpR = C5H4SiMe2Cl, LL = MMA (2a), MA (2b), MO (2c); CpR = C5H4SiMe3, LL = MMA (3a), MA (3b)] in variable yields depending on both the cyclopentadienyl and the ,,,-unsaturated carbonyl compounds. The reactivity of these complexes was studied toward protic and Lewis acids. Addition of triflic acid TfOH (Tf = CF3SO2) to 3b gave the triflate complex [NbCpRCl2{(CH2)2C(O)OMe}(OTf)] [CpR = C5H4SiMe3 (4)]. The Lewis acids E(C6F5)3 (E = B, Al) reacted with complexes 2b and 3b to give the three-membered metallacyclic (or ,2 -enone) compounds [NbCpRCl2{,2 -CH2=CHC(OMe){O·E(C6F5)3}}] [CpR = C5H4SiMe2Cl, E = B (5), Al (6); CpR = C5H4SiMe3, E = B (7), Al (8)], which decomposed to the corresponding adducts MA·E(C6F5)3. The same reaction with the 2a and 3a derivatives only allowed the observation of the corresponding adducts MMA·E(C6F5)3. Complexes 2a,b and 3a,b reacted with CO with elimination of the acrylate compounds, MA and MMA, respectively, to give the carbonylniobium(III) compounds [NbCpRCl2(CO)2]2 [CpR = C5H4SiMe2Cl (9), C5H4SiMe3 (10)]. Analogous reactions with CNAr showed the elimination of the free MA and MMA compounds. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source]


Facile Formation of Hexacyclic [Al3O2Cl] Aluminum and Alkoxide-Bridged Titanium Complexes: Reactions of AlMe3 with [Ti(L)Cl2] [L = 2,2,-Methylenebis(6- tert -butyl-4-methylphenolato)]

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 19 2007
Dao Zhang
Abstract The titanium dichloride complex [(L)TiCl2] [L = 2,2,-methylenebis(6- tert- butyl-4-methylphenolato)] (1) reacted with trimethylaluminum (AlMe3) in a 1:2 ratio to give a trimetallic aluminum complex of the composition [(L)(AlMe2)3(,-Cl)] (2) with a symmetric six-membered ring [Al3(,2 -O)2(,2 -Cl)] and a four-coordinate aluminum center in the solid state. The reaction of 1 equiv. AlMe3 gave [(L)TiMeCl] (3), which could absorb O2 gas to afford the oxygen-insertion product [{(L)TiCl}2(,-OMe)2] (4) with a five-coordinate metal center. Upon reaction of H2L with AlMe3, the binuclear, four-coordinate adduct [{(L)AlMe}2] (5) was formed. Complex 4 supported on MgCl2 and activated with aluminum alkyls reveals high catalytic activity for ethylene polymerization to produce polymers with molecular weight distributions of ca. 3.1. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007) [source]


An Unusual Reaction of (,-Dimethylaminoethoxy)triethyltin with Phenyltin Trichloride.

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 21 2006
Aryl; X, Symmetrical Dimers [R2SnXY], The First X-ray Structural Evidence of the Existence of Complexes R2SnXY·R2SnXY (R = Alkyl, Y = Hal, Y) Both as Unsymmetrical Adducts [R2SnX2·R2SnY2]
Abstract The substituent exchange reaction of PhSnCl3 with [Et3Sn(OCH2CH2NMe2)] gives rise unexpectedly to the unsymmetrical adduct [Ph2SnCl2·Ph2Sn(OCH2CH2NMe2)2] (2). It has been unambiguously proved for the first time that compounds of the RSnX3 type are able to undergo the hydrocarbon substituent redistribution reaction. The analogous tin complexes [Et2SnCl2·Et2Sn(OMe)2] (5) and [Bu2Sn(OAc)2·Bu2Sn(OMe)2] (6), which have ligands other than ,-dimethylaminoethoxy and could be considered as "organotin analogs of Grignard reagents" have symmetrical dimeric structures, i.e., can be formulated as [Bu2Sn(OMe)(OAc)]2 and [Et2Sn(OMe)Cl]2, respectively. Both types of structures, viz., unsymmetrical adduct (2) and symmetrical dimer (5, 6), have been characterized by X-ray diffraction analysis. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source]


A Single-Source-Precursor Approach to Late Transition Metal Molybdate Materials: The Structural Role of Chelating Ligands in the Formation of Heterometallic Heteroleptic Alkoxide Complexes

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 7 2006
Pia Werndrup
Abstract The synthesis and structural determination of three new heterometallic molybdenum complexes, one with cobalt and two with nickel and two of these with ,-diketonate ligands and one with amino alcohol ligands, are presented. The reaction of cobalt acetylacetonate with [MoO(OMe)4] provides [Co2Mo2O2(acac)2(OMe)10] (1) and [MoO(acac)(OMe)3] (4),and the reaction of nickel acetylacetonate with [MoO(OMe)4]provides [Ni2Mo2O2(acac)2(OMe)10] (2) and 4. The reaction of [Ni(ORN)2] (RN = CHMeCH2NMe2) with [MoO(OMe)4] yields [Ni2Mo2O2(ORN)2(OMe)10] (3). The two new oxomolybdenum complexes undergo ether elimination upon storage to give the corresponding dioxo complexes [MoO2(acac)(OMe)]2 (5) and [MoO2(ORN)(OMe)]2 (6). Compounds 3 and 4 could also be obtained from the reaction of stoichiometric amounts of Hacac with [MoO(OMe)4] and [MoO2(OMe)2], respectively. The local structure around the nickel atom in compound 2 in solution and compound 3 in the solid state and in toluene/hexane solution has been determined by means of EXAFS spectroscopy. The complexes are intended to be used as single-source precursors, which are attractive in coatings and for the preparation of mesoporous materials; its application for the synthesis of nickel molybdate by sol,gel processing is therefore reported. The oxide material obtained from 3 displays a uniform grain size and a large surface area. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source]


Synthesis, Structure and Reactivity of Homo- and Heterobimetallic Complexes of the General Formula [Cp*Ru(,-Cl)3ML] [LM = (arene)Ru, Cp*Rh, Cp*Ir]

EUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 1 2006
Laurent Quebatte
Abstract The homo- and heterobimetallic complexes [Cp*Ru(,-Cl)3ML] [LM = (C6H6)Ru, (cymene)Ru, (1,3,5-C6H3iPr3)Ru, Cp*Rh, Cp*Ir] were prepared by reaction of [Cp*Ru(,-OMe)]2 with Me3SiCl and subsequent addition of [LMCl2]2. The complexes [Cp*Ru(,-Cl)3Ru(cymene)] and [Cp*Ru(,-Cl)3IrCp*] were characterized by single-crystal X-ray analyses. In crossover experiments with [Cp*Rh(,-Cl)3RuCl(PPh3)2] and [Cp*Ru(,-Cl)3Ru(1,3,5-C6H3iPr3)] in CD2Cl2, a dynamic equilibrium with the complexes [Cp*Rh(,-Cl)3RuCp*] and [(1,3,5-C6H3iPr3)Ru(,-Cl)3RuCl(PPh3)2] was rapidly established, demonstrating the kinetic lability of the triple chloro bridge. Upon reaction of [Cp*Rh(,-Cl)3RuCp*] with benzene, the ionic complex [Cp*Ru(C6H6)][Cp*RhCl3] was formed, which was characterized by X-ray crystallography. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006) [source]