Synthesis and two-photon absorption property characterizations of small dendritic chromophores containing functionalized quinoxaliniod heterocycles.

A series of star-shaped multi-polar chromophores (compounds 1-3) containing functionalized quinoxaline and quinoxalinoid (indenoquinoxaline and pyridopyrazine) units has been synthesized and characterized for their two-photon absorption (2PA) properties both in the femtosecond and the nanosecond time domain. Under our experimental conditions, these model fluorophores are found to manifest strong and wide-dispersed two-photon absorption in the near-infrared region. It is demonstrated that molecular structures with multi-branched π frameworks incorporating properly functionalized quinoxalinoid units would possess large molecular nonlinear absorptivities within the studied spectral range. Effective optical-power attenuation and stabilization behaviors in the nanosecond time domain of a selected representative dye molecule (i.e., compound 2) from this model compound set were also investigated and the results indicate that such structural motif could be a useful approach for the molecular design toward strong two-photon-absorbing material systems for quick-responsive and broadband optical-suppressing-related applications, particularly to confront long laser pulses.

High computed tomographic correlations between carotid canal dehiscence and high jugular bulb in the middle ear.

Both carotid canal dehiscence (CCD) and high jugular bulb (HJB) are thought to increase the potential for disastrous consequences during middle ear surgery. Clinical co-presentation of these two great vessel variants has not yet been described. This study aims to determine the relationship between CCD and HJB based on a computed tomographic (CT) temporal bone evaluation. High-resolution CT scans of 408 temporal bones obtained from 208 adults were recruited. Carotid canal integrity, jugular bulb position, petrous apex pneumatization and the minimal thickness of the carotid canal wall (TCW) facing the tympanic cavity were examined and measured for the incidence of CCD and/or HJB. Other variables including gender, age, laterality and the presence of otitis media or mastoiditis were also collected for analysis. CCD was found in 28 ears (6.9%); 19 of these were found to also have HJB (67.9%). The presence of CCD was significantly correlated with HJB presentation. The minimal TCW in HJB ears was significantly thinner than that of normally positioned jugular bulbs. Moreover, after controlling for other candidate variables, the independent factors of age (younger or older than 50 years) and jugular bulb position (high vs. normal) were found to predict the presence of CCD. In conclusion, HJB tends to coexist with a thinner carotid canal wall. This finding emphasizes the need to be watchful for the coexistence of these two great vessel anomalies when surgeons encounter an aged patient presenting either CCD or HJB during middle ear surgery.

Risk of Acquired Cholesteatoma and External Auditory Canal Stenosis in Traumatic Brain Injury: A Nationwide Population-Based Cohort Study.

The aim of study is to investigate the risk of developing acquired cholesteatoma and external auditory canal (EAC) stenosis after traumatic brain injury (TBI) from the Taiwan National Health Insurance Research Database (NHIRD). Each subject was individually traced from their index date to identify those who received a diagnosis of acquired cholesteatoma and EAC stenosis. Cox regression analyses were applied to determine the risk of TBI-related acquired cholesteatoma and EAC stenosis. The follow-up data collected over 10 years were obtained from the TBI and comparison cohorts, of 455,834 and 911,668 patients, respectively. Multivariate analysis demonstrated that TBI significantly increased the risk of cholesteatoma (adjusted hazard ratio (HR), 1.777; 95% confidence interval (CI), 1.494-2.114, p < 0.001) and EAC stenosis (adjusted (HR), 3.549; 95% (CI), 2.713-4.644, p < 0.001). In our subgroup injury analysis, falls had the highest associated risk (4.308 times), followed by traffic injuries (66.73%; 3.718 times that of the control group). Otolaryngologists should not neglect the clinical importance and carefully investigate the possibility of subsequent cholesteatoma and EAC stenosis, which leads to hearing impairment in patients with TBI. Our research also shows the important role in preventing TBI, especially as a result of traffic injuries and falls.

Mastoid obliteration, scutum plasty, and ossiculoplasty without staging after canal-wall-up attico-mastoidectomy in adults.

In a retrospective chart review, we evaluated the surgical and hearing results of a single-stage procedure consisting of a canal-wall-up attico-mastoidectomy, mastoid cavity obliteration, scutum plasty, and ossiculoplasty. A total of 77 patients treated between March 2003 and January 2011 with postoperative follow-up of at least 60 months were enrolled. Preoperative and postoperative pure-tone average (PTA) and air-bone gap (ABG) were assessed and compared 1 and 5 years after surgery. At the final follow-up, the tympanic membrane was intact in 71 (92.2%) patients. Retraction pockets were found in 10 (13.0%) patients: with 9 (11.7%) in the pars tensa, 5 (6.5%) in the posterior tympanic sinus, and 2 (2.6%) in the attic region (some patients had multiple sites of retraction). Two (2.6%) patients developed recurrent cholesteatoma and underwent revision surgery. During the follow-up, 7 (9.1%) patients were found to have partial canal wall deformities; 5 (6.5%) were in the scutum region and 4 (5.2%) in the posterior canal wall. Long-term improvement and/or preservation of hearing were obtained in 55.8% of patients, and maintenance of PTA-ABG closure was within 20 dB. In conclusion, the hearing results and surgical outcomes of our single-stage procedure were satisfactory and similar to those in other reports. We conclude that our technique may be used as an alternative in the management of adult cholesteatoma.

Dehiscent high jugular bulb: a pitfall in middle ear surgery.

OBJECTIVE: The aim of this study was to present our experience on facing the dehiscent high jugular bulb (HJB) during middle ear surgery in the past 2 decades. STUDY DESIGN: Retrospective review. SETTING: Secondary referral hospital. PATIENTS: From January 1982 to June 2002, consecutive 1,657 patients underwent surgical intervention for middle ear cleft diseases, a total of 1,857 operations. Of them, 10 ears (0.5%) in nine patients were proven to have dehiscent HJB during operation for adhesive otitis media in four ears and for chronic otitis media with cholesteatoma in six ears. MAIN OUTCOME MEASURES: Each patient underwent otoscopic examination, radiographic examination, and audiometry before and 6 months after operation. RESULTS: Otoscopic examination revealed atrophic changes in the pars tensa with adhering to the promontory in two ears, attic retraction in one ear, and both findings in seven ears. All lesions were located beneath the basal turn of the cochlea and the round window niche at anteroinferior and/or posteroinferior quadrants. Active bleeding was encountered in two ears (20%) while elevating the tympanomeatal flap, which was treated by pressure compression associated with gelfoam sheet, then covered with an autologous cartilage to protect the dehiscent bulb. For the remaining eight ears, the bulbs were reinforced with fascia, perichondrium, or autologous cartilage. All 10 ears were allowed completion of the planned surgery without complications. CONCLUSION: HJB is not a contraindication for middle ear surgery. Awareness of this pitfall may lessen the operation risk.

Obliteration of Radical Cavities and Total Reconstruction Procedure Without Staging After Canal Wall Down Mastoidectomy: Long-term Results.

OBJECTIVES: We evaluate the long-term surgical and hearing results using a canal wall down mastoidectomy technique followed by cavities obliteration, canal wall reconstruction and ossiculoplasty without staging. METHODS: A total of 44 patients between January 2002 and October 2009 were selected and 27 of them were revision cases. Preoperative and postoperative pure tone average (PTA) and air-bone gap (ABG) were assessed and compared 1 and 4 years after surgery. RESULTS: The middle ear was well healed and aerated in 40 patients (90.9%) and the tympanic membrane was intact in 42 patients (95.5%). Recurrent cholesteatoma was found on postoperative follow-up in two of the revision patients (7.4%) but none in the primary patients. Seven patients were found to have partial canal bone absorption, but revision surgery was not required. Over 86.4% of all cases were water resistant. Long-lasting improvement and/or preservation of hearing, with maintenance of PTA-ABG closure in 63.7% of all cases within 20 dB, were obtained. CONCLUSION: The efficacy of our technique after a canal wall down mastoidectomy is satisfactory, and the rate of complication is acceptably low. We believe that our technique could be a convenient method in disease control and providing an excellent basis for hearing restoration simultaneously.

Surgical results of retrograde mastoidectomy with primary reconstruction of the ear canal and mastoid cavity.

The aim of this study was to retrospectively review the long-term hearing results and the impact of mastoid exclusion/obliteration in patients with cholesteatoma (102 ears) who underwent retrograde tympanomastoidectomy and in whom bone chips/paté were applied as the sole materials during the procedure. In 79 ears, this was combined with ossiculoplasty in a single-stage procedure. In >71% of ears, the results of audiometric testing were monitored for more than 2 years. The results suggested there was a significant gain in hearing following surgery, with respect to the postoperative change in both air-conduction thresholds and air-bone gaps (P < 0.001). Linear regression analyses of pure-tone averages at different frequencies, before and after surgery, demonstrated that patients benefitted from a postoperative hearing gain at low and middle frequencies, but their hearing often deteriorated at frequencies of 8000 Hz. As for the impact of the type of tympanoplasty on hearing outcomes, type III-interposition markedly increased hearing gain. The overall rate of postoperative adverse events was 8.8%. We conclude that reconstruction of the ear canal and mastoid via mastoid exclusion/obliteration using bone chips/paté can be considered as an alternative procedure following retrograde mastoidectomy. It gives excellent surgical results and has fewer postoperative adverse events.

A sulfhydryl-reactive ruthenium (II) complex and its conjugation to protein G as a universal reagent for fluorescent immunoassays.

To develop a fluorescent ruthenium complex for biosensing, we synthesized a novel sulfhydryl-reactive compound, 4-bromophenanthroline bis-2,2'-dipyridine Ruthenium bis (hexafluorophosphate). The synthesized Ru(II) complex was crosslinked with thiol-modified protein G to form a universal reagent for fluorescent immunoassays. The resulting Ru(II)-protein G conjugates were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The emission peak wavelength of the Ru(II)-protein G conjugate was 602 nm at the excitation of 452 nm which is similar to the spectra of the Ru(II) complex, indicating that Ru(II)-protein G conjugates still remain the same fluorescence after conjugation. To test the usefulness of the conjugate for biosensing, immunoglobulin G (IgG) binding assay was conducted. The result showed that Ru(II)-protein G conjugates were capable of binding IgG and the more cross-linkers to modify protein G, the higher conjugation efficiency. To demonstrate the feasibility of Ru(II)-protein G conjugates for fluorescent immunoassays, the detection of recombinant histidine-tagged protein using the conjugates and anti-histidine antibody was developed. The results showed that the histidine-tagged protein was successfully detected with dose-response, indicating that Ru(II)-protein G conjugate is a useful universal fluorescent reagent for quantitative immunoassays.

En bloc surgical removal of an asymptomatic glomus tympanicum tumor.

Glomus tympanicum (GT) tumors are usually characterized by pulsatile tinnitus and hearing loss. We report on a woman 53 years of age who was diagnosed with a GT tumor within her right ear with no associated tinnitus or hearing loss on presentation. An early GT tumor without the characteristic symptoms is seldom encountered. Although several papers have dealt with GT tumor diagnosis and management, very few have demonstrated such a condition in which the entire GT tumor appeared in the middle ear cavity and was totally removed during the operation. There was no recurrence at 24 months of follow-up. We describe a novel surgical technique in this article and demonstrate an en bloc GT surgical removal that has been seldom published before in the literature.