Globus pharyngeus due to a lymphangiomatous polyp arising from the tonsil

INTRODUCTION

Lymphangiomatous polyp of the tonsil is generally accepted as a hamartomatous lesion. Its differential diagnosis includes fibroepithelial polyp, squamous papilloma, angiofibroma, haemangioma, arteriovenous malformation, hamartoma and lymphangioma.

CASE REPORT

A 33-year-old man presented with 2 months history of feeling of foreign body sensation in the throat. Examination revealed a nodular red coloured polyp on the left tonsil. Histologically, the polyp was covered by squamous epithelium and is composed of numerous vascular channels containing lymphocytes and eosinophilic material, in a fibrous stroma. Immunohistochemically, the endothelial cells were positive toward CD31 and D2-40.

DISCUSSION

The characteristic histological features of a lymphangiomatous polyp are benign vascular proliferation with variable fibrous, adipose and lymphoid stromal components. Nested intraepithelial epidermotropism of lymphocytes can be observed. The vascular channels are typically thin-walled and contain eosinophilic proteinaceous material and lymphocytes. There is no reported incidence of recurrent or malignant transformation.

A Comparison of the GlideScope® with the Macintosh Laryngoscope for Tracheal Intubation in Patients with Simulated Difficult Airway

We compared the use of the GlideScope® and the conventional Macintosh laryngoscope in a simulated difficult airway. The primary hypothesis was that time to intubation would be shorter using the GlideScope® than using the Macintosh laryngoscope.

After obtaining approval from the ethics committee and written informed consent, we recruited 60 ASA 1 and 2 patients to our randomized controlled trial. Group G (n=30) had tracheal intubation performed using the GlideScope® and Group M (n=30) were intubated using a Macintosh laryngoscope. We simulated a difficult airway in each patient by having an experienced assistant provide in-line manual stabilization of the head and neck. We recorded the best laryngeal view; difficulty of the tracheal intubation; time taken for successful tracheal intubation; manoeuvre needed to aid tracheal intubation and complications associated with the tracheal intubation.

The median Cormack and Lehane grade was significantly better in Group G than Group M. Group G had a significantly shorter intubation time than group M (mean 41.8s±SD 20.2 vs mean 56.2s±26.6, P<0.05).

The GlideScope® improved the laryngeal view and decreased time for tracheal intubation time when compared with the Macintosh laryngoscope in patients with simulated difficult airway. The GlideScope® may be a good alternative for managing the difficult airway but clinical trials evaluating its use on patients with an actual difficult airway are needed.

Comparative study of new autologous material, bone-cartilage composite graft, for ossiculoplasty with Polycel® and Titanium

OBJECTIVE

Ossiculoplasty is a surgical procedure that recreates sound transmission of the middle ear in conductive hearing loss. Various materials have been used for ossicular reconstruction, but the most ideal material for ossiculoplasty remains controversial. The purpose of this study was to introduce a novel method of autologous ossiculoplasty, bone-cartilage composite graft (BCCG) and to compare its surgical results with different types of ossiculoplastic prostheses.

STUDY DESIGN

A retrospective study was performed in a tertiary referral centre.

METHODS

Data of 275 patients who received ossiculoplasty using the three different materials of BCCG, Polycel^® and titanium were analysed according to type of ossiculoplasty: partial or total ossicular replacement prosthesis (PORP or TORP). Hearing results, complication rates and clinical parameters including age, sex, past history, preoperative diagnosis and surgery type were compared among different groups.

RESULTS

Ossiculoplasty with BCCG showed satisfactory hearing outcomes and the lowest complication rate among the three different materials. In particular, its extrusion rate was 0%.

CONCLUSION

We propose that the BCCG technique is a useful alternative method for ossiculoplasty, with proper patient selection.

Functional Significance of Medial Olivocochlear System Morphology in the Mouse Cochlea

Objectives

Baso-apical gradients exist in various cochlear structures including medial olivocochlear (MOC) efferent system. This study investigated the cochlear regional differentials in the function and morphology of the MOC system, and addressed the functional implications of regional MOC efferent terminals (ETs) in the mouse cochlea.

Methods

In CBA/J mice, MOC reflex (MOCR) was assessed based on the distortion product otoacoustic emission in the absence and presence of contralateral acoustic stimulation. High, middle, and low frequencies were grouped according to a mouse place-frequency map. Cochlear whole mounts were immunostained for ETs with anti-α-synuclein and examined using confocal laser scanning microscopy. The diameters of ETs and the number of ETs per outer hair cell were measured from the z-stack images of the basal, middle and apical regions, respectively.

Results

The middle cochlear region expressed large, clustered MOC ETs with strong MOCR, the base expressed small, less clustered ETs with strong MOCR, and the apex expressed large, but less clustered ETs with weak MOCR.

Conclusion

The mouse cochlea demonstrated regional differentials in the function and morphology of the MOC system. Strong MOCR along with superior MOC morphology in the middle region may contribute to ‘signal detection in noise,’ the primary efferent function, in the best hearing frequencies. Strong MOCR in spite of inferior MOC morphology in the base may reflect the importance of ‘protection from noise trauma’ in the high frequencies.

A causal relationship between hearing loss and cognitive impairment

CONCLUSION

Moderate hearing loss in young mice caused decreases in cognition associated with spatial working and recognition memories in 6 months. These results provide evidence for a causal relationship between hearing loss and cognitive impairment.

OBJECTIVES

Hypothesized mechanisms to connect sensory and cognitive functions include the sensory-deprivation, information-degradation, and common-cause hypotheses. This study intended to investigate the effect of hearing loss on cognitive function, as estimated by radial arm maze (RAM) and novel object recognition (NOR) tasks in mice through age- and hearing-matched longitudinal work during a 6-month period.

METHODS

Twenty-four male C57BL/6 mice aged 1 month with normal ABR thresholds were used. Twelve mice in the hearing loss (HL) group were exposed to white noise at 110 dB SPL for 60 min every day for 20 days. At post-noise 6 months, all mice underwent RAM and one-trial NOR test. RAM performance measures and NOR discrimination index were compared between two groups.

RESULTS

At 6 months after noise exposure, all mice in the experimental group had moderate hearing loss. Most of the RAM performances improved gradually within each group across five trials, probably due to learning effect. The HL group showed lower performance scores than the control group in several trial points in the RAM task. The contact time with the novel object was shorter in the HL group than in the control group.

Protective effect of unilateral and bilateral ear plugs on noise-induced hearing loss: functional and morphological evaluation in animal model

The aim of the following study is to evaluate immediate protective effect of ear plug from noise morphologically and functionally. An 1-month aged 29 male C57BL/6 mice. Subjects were divided into four groups as normal control(G1), bilaterally plugged group (G2), unilaterally plugged group (G3) and noise control group (G4) and later 3 groups were exposed to 110 sound pressure level white noise for 60 min. Immediately after noise exposure, audiologic tests were performed and cochlear morphology and expression levels of a-synuclein in the cochlea were investigated. There were no functional changes in G2 and plugged ears of G3 after noise exposure, whereas unplugged ears of G3 and G4 showed significant hearing loss. In morphological study, there were a significant degeneration of the organ of Corti and mean number and diameter of efferent buttons, in unplugged ears of G3 and G4. Plugged ears of G3 also showed mild changes in morphological study. Reduction of a-synuclein was observed at the efferent terminals or cochlear extracts after noise exposure. The protective effect of ear plug on noise exposure was proven morphologically and functionally in the animal model of noise-induced hearing loss. Further study on cellular or ultrastructural level with ear plug will be needed to reveal more precise mechanism.

Anoctamin 1 expression in the mouse auditory brainstem

Calcium-activated chloride channels (CaCCs) are involved in numerous physiological functions, including the epithelial movement of fluid. Anoctamin 1 (ANO1) has recently been cloned and characterized as a CaCC and is known to be expressed in various secretory epithelia and in nervous tissues such as the dorsal root ganglia and retina. However, data regarding the expression, function, and cellular and subcellular localization of CaCCs in the brain are still limited. We investigated the distribution and expression patterns of ANO1 in adult mouse brain. Reverse transcriptase plus the polymerase chain reaction, Western blot, and immunohistochemical analyses demonstrated that ANO1 was widely distributed throughout the brain. Furthermore, ANO1 was strongly expressed in two auditory brainstem nuclei: the medial nucleus of the trapezoid body (MNTB) and the anteroventral cochlear nucleus (AVCN). Double-labeling experiments revealed that this ANO1 expression was exclusive to the presynaptic endings of both the MNTB and AVCN. ANO1 is thus mainly localized at presynaptic terminals in various brain regions, specifically in two auditory brainstem nuclei, the MNTB and AVCN, and might therefore contribute to the high-frequency synaptic transmission of auditory signals.

A case of direct intracranial extension of tuberculous otitis media

We describe a very rare case of tuberculous otitis media (TOM) with direct intracranial extension. The patient was a 55-year-old man who presented to our ENT clinic for evaluation of severe headaches and right-sided otorrhea. A biopsy of granulation tissue obtained from the right external auditory canal demonstrated chronic inflammation that was suggestive of mycobacterial infection. Magnetic resonance imaging of the brain indicated intracranial extension of TOM through a destroyed tegmen mastoideum. After 2 months of antituberculous medication, the headaches and otorrhea were controlled, and the swelling in the external ear canal subsided greatly. Rarely does TOM spread intracranially. In most such cases, intracranial extension of tuberculosis occurs as the result of hematogenous or lymphogenous spread. In rare cases, direct spread through destroyed bone can occur, as it did in our patient.

Effects of meteorological factors on the onset of Bell's palsy

OBJECTIVE

The etiology of Bell's palsy (BP) has not yet been clarified, although viral infection or reactivation is probably a major cause. The objective of this study was to evaluate the effects of meteorological factors on the onset and incidence of BP.

METHODS

Meteorological data from 2007 to 2011 were obtained from the Web-based 'Monthly Weather Reports of the Meteorological Administration' database. Patients with BP who attended Incheon St Mary's Hospital during the same period, presenting on the precise day that their symptoms appeared, were included in this retrospective chart review. Twelve meteorological factors were compared for days on which BP onset was and was not observed. The weather conditions occurring 1-7 days before BP onset (D-1-D-7) were included to assess any possible delayed effects of meteorological factors on the onset of BP. The seasonal and monthly distributions of BP were evaluated.

RESULTS AND CONCLUSION

The mean values for the meteorological parameters did not differ significantly between the days when BP onset did and did not occur. However, the maximum wind speed on day -1 (D-1) was significantly higher for BP onset days than for days with no BP onset. The seasonal and monthly distributions of BP did not differ significantly. It is suggested that stronger wind speed of preceding day may be related to the occurrence of BP.

Hearing restoration in a deaf animal model with intravenous transplantation of mesenchymal stem cells derived from human umbilical cord blood

OBJECTIVE

This study was performed to confirm the effect of transplantation of human umbilical cord blood mesenchymal stem cells (UCB-MSCs) on hearing restoration in a sensorineural hearing loss (SNHL) animal model.

MATERIAL AND METHODS

UCB was collected from pregnant women after obtaining consent, and mesenchymal stem cells (MSCs) were extracted. We established an SNHL model and transplanted UCB-MSCs through the brachial vein of the guinea pigs. The animals were divided into 4 groups: animals with normal hearing, animals with SNHL, animals with SNHL and injected with saline, and animals with SNHL and transplanted with UCB-MSCs. Hearing tests were conducted at 1, 3, and 5 weeks, and the results were compared by grading auditory brainstem response (ABR) recordings and distortion product otoacoustic emissions (DPOAEs) for each treatment. Lastly, cochlear pathological features were examined, and surface preparations and morphological changes in each animal model were compared using hematoxylin and eosin staining and light microscopy studies.

RESULTS

In SNHL group, decreased DPOAEs and increased ABR threshold were noted. Furthermore, in the SNHL group, ABR hearing thresholds were unconverted and were similar to those observed in deafness. The transplanted UCB-MSC group showed a significant improvement in hearing threshold (40 dB) compared to that in all the SNHL group (80-90 dB). Examination of the SNHL animals' cochlear morphological features demonstrated a noticeable lack of spiral ganglion cells and also showed degenerated outer hair cells. However, the transplanted UCB-MSCs showed an increase in spiral ganglion and hair cells.

CONCLUSION

Intravenous transplantation of UCB-MSCs can enhance hearing thresholds, outer-hair cells and increase the number of spiral ganglion neurons (SGNs).

Comparison of functional and morphologic characteristics of mice models of noise-induced hearing loss

OBJECTIVES

This study was conducted to compare morphologic and audiologic changes after noise exposure in two different strains of mice (CBA and C57) and to create morphologically proven models of noise-induced hearing loss.

METHODS

Mice were exposed to white noise at 110-dB sound-pressure level for 60 minutes at the age of 1 month. Hearing thresholds and outer hair cell functions were evaluated by auditory brainstem response recordings and distortion product otoacoustic emission immediately and 22 days after noise exposure. Cochlear pathology was observed and compared by light and electron microscopic studies.

RESULTS

Both mice strains showed hearing threshold shifts with decreased outer hair cell function immediately and 22 days after noise exposure. More severe auditory brainstem response threshold shifts were observed in C57 mice compared with CBA mice at click, 8-, 16-, and 32-kHz tone-burst stimuli. A cochlear morphologic study demonstrated predominant outer hair cell degeneration at all turns of the cochlea; degeneration was most severe at the basal turn in both mice strains. A scanning electron microscopic study revealed more severe ultrastructural damage of outer hair cells at each turn of the cochlea in C57 mice. The lateral wall of the cochlea was more severely degenerated in CBA mice.

CONCLUSION

Both mice strains showed consistent, permanent noise-induced hearing loss with different susceptibilities and site vulnerabilities. Further studies to investigate the mechanism of the different degree and cochlear site vulnerability to noise exposure between two mice strains are necessary.

Prevalence and significance of high-frequency hearing loss in subjectively normal-hearing patients with tinnitus

OBJECTIVES

We investigated the incidences of high-frequency hearing loss (HFHL; above 2 kHz) and extended high-frequency hearing loss (EHFHL; above 8 kHz) in patients with tinnitus and subjectively normal hearing, and evaluated their effects on the clinical and audiological features of the patients.

METHODS

The sample included 85 patients with sensorineural tinnitus who had normal hearing sensitivity in the frequencies from 250 Hz to 2 kHz, and who had undergone extended high-frequency audiometry between July 2009 and February 2010. We investigated the incidences of HFHL and EHFHL in these patients and analyzed the significance of the hearing losses.

RESULTS

The incidence of HFHL or EHFHL was 88%. The proportion of patients with EHFHL, among the patients who had normal hearing sensitivity up to 8 kHz, was about 74%. The patients with normal hearing sensitivity at all test frequencies were significantly younger, had larger otoacoustic emissions, and had tinnitus that was less loud as measured by tinnitus matching than did the subjects with HFHL and/or EHFHL. However, other comparisons of clinical factors in the three groups did not show any differences.

CONCLUSIONS

Even if patients with tinnitus do not have any subjective hearing impairment, most of them have HFHL and/or EHFHL. The effects on the clinical features of the patients are still vague.

Expression and immunohistochemical localization of TMEM16A/anoctamin 1, a calcium-activated chloride channel in the mouse cochlea

Sound transduction in the cochlea depends on the unique high concentrations of K(+) in the endolymph. The production and maintenance of high K(+) concentrations are accompanied by Cl(-) cycling. In this study, we report on an investigation of the expression and localization of TMEM16A/anoctamin 1 (ANO1), a recently cloned Ca(2+)-activated Cl(-) channel, in the mouse cochlea by Western blot and immunhistochemistry. The ANO1 protein was identified in the cochlea by Western blotting. The immunoreactivity was found in stria vascularis as a line and in the organ of Corti as three plaques. The cellular localization of ANO1 was examined by means of double-labeling experiments with anti-claudin 11, a marker for basal cells of the stria vascularis. The results demonstrated that ANO1 colocalized with claudin 11, indicating its expression in basal cells. We also examined ANO1 localization in the organ of Corti by double- and triple-labeling techniques with anti-myosin VI, a marker for hair cells, and anti-synaptophysin, a marker for olivocochlear efferent nerve endings under hair cells. The results clearly showed that ANO1 is colocalized with synaptophysin, but not with myosin VI, indicating that ANO1 is localized at medial olivocochlear efferent nerve endings under outer hair cells. These results suggest that ANO1 may be specifically involved in synaptic transmission from medial olivocochlear efferent nerve endings to outer hair cells in the organ of Corti, as well as Cl(-) cycling in basal cells of the stria vascularis.

Clinical efficacy of fat-graft myringoplasty for perforations of different sizes and locations

CONCLUSION

Fat-graft myringoplasty (FGM) has a reliable tympanic closure rate for small to large perforations, but yields poor hearing improvement in the latter case. A topographic evaluation of FGM showed that the procedure resulted in a reliable perforation closure rate and audiologic outcome, regardless of perforation location.

OBJECTIVES

This study assessed the utility of FGM in treating perforations of different sizes and locations.

METHODS

This retrospective study involved 45 patients (46 ears) who underwent FGM at St Mary's Hospital (Seoul, Korea) between August 2007 and February 2010.

RESULTS

The total perforation closure rate after FGM was 87% (40 cases), with no statistical difference among perforation size groups, even though the mean closure rates of the 10-20% and >30% perforation groups were lower than other groups. The difference in the closure rates of patients with anteriorly located perforations and those with perforations in other sites was not significant. The mean postoperative air-bone gap (ABG) was 14.3 (±7.5) dB. Mean postoperative ABG improved significantly after FGM; however, on a per-group basis, the >30% perforation group had the poorest results and the difference was statistically significant. The difference in mean postoperative ABGs of the two groups depending on the location of the perforation (anterior and other) was not significant.

The appropriate medical management of methicillin-resistant Staphylococcus aureus in chronic suppurative otitis media

CONCLUSION

Methicillin-resistant Staphylococcus aureus (MRSA) was the most prevalent species (28.1%) in the bacteriological study of 577 patients with chronic suppurative otitis media (CSOM). Frequent and appropriate aural cleansing and irrigation using diluted acetic acid or other solutions such as Burow's solution can be an effective method for the medical treatment of MRSA in CSOM.

OBJECTIVES

To investigate the bacteriological results of 577 patients with CSOM and the medical treatment results of 91 non-cholesteatomatous MRSA patients and to consider the most appropriate medical treatment modality for MRSA in patients with CSOM.

PATIENTS AND METHODS

This study was conducted retrospectively from January 2005 through July 2008 using the medical records of 577 patients with otorrhoea caused by CSOM. We analyzed the bacteriological results by dividing all patients into cholesteatomatous CSOM and non-cholesteatomatous CSOM and investigated the medical treatment results of 91 non-cholesteatomatous MRSA patients. We used three treatment modalities: aural cleansing and irrigation (50 cases), intravenous injection of teicoplanin (22 cases) and intravenous injection of vancomycin (15 cases).

RESULTS

Overall, MRSA (28.1%) was the most prevalent species, followed by methicillin-susceptible Staphylococcus aureus (MSSA) (20.4%), Pseudomonas (18.6%) and coagulase-negative staphylococci (CNS) (15.0%). In non-cholesteatomatous MRSA treatment for dry ear, there were no significant differences between the three groups. The results showed that 79.5% of the group treated with aural cleansing and irrigation succeeded in achieving dry ears in 19.0 days. Similarly, 78.9% of another group with intravenous injection of teicoplanin eventually had dry ears, taking 16.0 days. Finally, the number of patients with dry ear in the group treated with intravenous injection of vancomycin was up to 80% of the total in 15.2 days.

Clinical experience of 71 cases of congenital middle ear cholesteatoma

CONCLUSIONS

As congenital middle ear cholesteatoma (CMC) is a different disease entity from acquired cholesteatoma, early diagnosis is important for good treatment results. Preoperative computed tomography (CT) imaging is a useful modality for both evaluation of the extent of the disease and selection of appropriate surgical methods. Some modification should be considered based on the findings of the actual operative field for complete removal of CMC.

OBJECTIVES

To present the results of surgical treatment of 71 cases of CMC and investigate the applicability of preoperative CT for the treatment of CMC.

PATIENTS AND METHODS

A retrospective study over an 11-year period was performed. The presenting symptoms, tympanic membrane findings, surgical findings, methods, and results were investigated retrospectively.

RESULTS

CMC was found incidentally in 38 cases (53.5%). A whitish mass medial to the tympanic membrane was observed in 62 cases (87%). Postoperative air-bone gap changes were not statistically significant. There was no predominance of localized lesions of the middle ear. The recurrence rate was 9.9% (seven cases), and higher in open type. Staging by CT and surgical staging matched in 70.4%. Positive predictive value for mastoid involvement of CT staging was 72.7%, with sensitivity and specificity of 68.6% and 87.5%, respectively.

Concomitant Inflammatory Pseudotumor of the Temporal Bone and Lung: A Case Report

Inflammatory pseudotumors are histologically benign but locally destructive lesions that are usually found in the lung, although some cases of temporal bone involvement have been reported. To the best of our knowledge, no case of simultaneous involvement of the temporal bone and the lung has been previously reported in the literature. We describe such a case in a 39-year-old man. The temporal bone lesion was removed in its entirety, and the lung lesion was treated with steroid therapy. At the 2-month follow-up, the size of the lung mass on chest x-ray was significantly reduced, and at 1 year, the patient was asymptomatic.

Concomitant inflammatory pseudotumor of the temporal bone and lung: a case report

Inflammatory pseudotumors are histologically benign but locally destructive lesions that are usually found in the lung, although some cases of temporal bone involvement have been reported. To the best of our knowledge, no case of simultaneous involvement of the temporal bone and the lung has been previously reported in the literature. We describe such a case in a 39-year-old man. The temporal bone lesion was removed in its entirety, and the lung lesion was treated with steroid therapy. At the 2-month follow-up, the size of the lung mass on chest x-ray was significantly reduced, and at 1 year, the patient was asymptomatic.

The effect of Bacillus Calmette-Guerin in a mouse model of allergic rhinitis

OBJECTIVE

To develop an allergic rhinitis model via local sensitization of mice with Dermatophagoides pteronyssinus and to use the model to investigate the antiallergic effect of Bacillus Calmette-Guerin (BCG).

METHODS

BALB/c mice were randomized to the allergic rhinitis group, the BCG group sensitized with D pteronyssinus via local sensitization for 7 weeks, or the control group. The BCG group received 1 x 10(5) colony-forming unit/mL of BCG seven times. We evaluated symptoms, nasal mucosa eosinophilia, serum total IgE, cytokines, and eosinophilia in bronchoalveolar lavage fluid.

RESULTS

In the allergic rhinitis group, allergy symptoms (P < 0.001), eosinophil count (P < 0.001), total IgE (P < 0.001), inflammatory cells (P < 0.01), and IL-13 (P = 0.046) increased and interferon gamma (IFN-gamma) (P < 0.001) decreased compared with the control group. In the BCG group, allergy symptoms (P < 0.001), eosinophil count (P < 0.001), and inflammatory cells (P < 0.01) decreased and IFN-gamma (P = 0.031) increased compared with the allergic rhinitis group.

CONCLUSION

In an allergic rhinitis animal model developed via local sensitization of mice with D pteronyssinus, BCG was shown to exhibit an antiallergic effect.

A BIS-guided study of sevoflurane requirements for adequate depth of anaesthesia in Caesarean section

Caesarean section carries a high risk of awareness, especially in the period prior to neonatal delivery. We investigated the concentration of sevoflurane required to maintain bispectral index (BIS) < 60 until delivery occurred. We enrolled 23 parturients into an up-down sequential allocation study. The median effective end-tidal concentration (EC(50)) of sevoflurane was defined as that which maintained BIS < 60 between skin incision and delivery in 50% of patients. This was calculated using Dixon and Massey's method. Receiver operating characteristic curve analysis was used to establish BIS response probability thresholds. The EC(50) for sevoflurane was 1.22% (1.08-1.33, 95% CI). The probability of maintaining BIS < 60 was < 55% at a concentration of < 1.1%; this increased to 80% at concentrations of 1.2-1.3%. We conclude that sevoflurane concentrations of at least 1.2-1.3% should be administered in uncomplicated Caesarean section, so as to minimise the risk of awareness and recall.

General anesthesia for cesarean section in a Singapore maternity hospital: a retrospective survey

We conducted a retrospective study of all cases of cesarean section at the KK Women's and Children's Hospital over a one-year period from September 1, 2002 to August 31, 2003, with the aim of evaluating current anesthetic practice. These cases were identified using hospital databases and relevant data was extracted from clinical notes. There were 14244 deliveries during the study period with a cesarean section rate of 25.2% (3583 cases). Of these, 20.4% (732 cases) were performed under general anesthesia. Maternal request was the chief reason for general anesthesia, especially among elective cases. Regional block failure accounted for 16% of the general anesthesia cases performed or 4.0% of the total regional techniques attempted. Regional block failure rate was highest for emergency cases in which an indwelling labor epidural catheter was used to provide surgical anesthesia via a bolus top-up. General anesthesia still has a definite place for cesarean delivery despite the predominant use of regional techniques in our institution.

Effects of antibiotics and steroid on middle ear mucosa in rats with experimental acute otitis media

The prevention of mucosal changes induced by experimental pneumococcal otitis media by means of antibiotics has been demonstrated previously. However, the effect of combined antibiotic and steroid therapy on the middle ear mucosa in acute otitis media (AOM) has not been determined. The right middle ears of 27 rats were inoculated with a log-phase type 3 Streptococcus pneumoniae, with the left ears serving as controls. Penicillin G was administered to nine rats and penicillin G and dexamethasone in combination were administered to nine rats after bacterial challenge; the remaining nine rats were not treated. Three animals from each group were sacrificed on Days 4, 7 and 14 after challenge. Tympanic membranes and middle ear mucosa were examined using otomicroscopy and light microscopy. Structural changes were diminished in both the antibiotic-treated and antibiotic + steroid-treated groups, compared with those in the untreated infected controls. The antibiotic + steroid-treated group showed the most marked decrease in structural change, especially in the mucosal metaplasia to the secretory epithelium. The results suggest that combination therapy with antibiotics and steroid in AOM is the most effective at reducing the treatment period and preventing persistent mucosal changes, which may decrease the risk of development of secretory otitis media as a sequela of AOM.

Effect of inhibitor of tumor necrosis factor-alpha on experimental otitis media with effusion

Tumor necrosis factor (TNF)-alpha is important in the pathogenesis of otitis media with effusion (OME). The purpose of this study was to determine the effect of TNF-alpha antagonist on the outcome of lipopolysaccharide (LPS)-induced OME in rats. Otitis media was induced by injecting Pseudomonas aeruginosa LPS transtympanically. Another (combination) group was pretreated with TNF-alpha antagonist, soluble TNF receptor type I (sTNF RI), before transtympanic injection of LPS. Saline and phosphate-buffered saline solutions were used as controls. Twelve hours after the transtympanic injection, otoscopic examination and aspiration of middle ear effusion (MEE) were done. The temporal bones in each group were examined histopathologically, and the vascular permeability of the middle ear mucosa was measured by the Evans blue vital dye technique. In the LPS and combination groups, MEE developed in 90% and 0% of ears, respectively. The combination group showed less inflammation, less mucosal thickening, and significantly decreased vascular permeability as compared to the LPS group. Transtympanic administration of sTNF RI appears to suppress the development of LPS-induced OME. This study suggests that TNF-alpha antagonist, along with antibiotics, may have an adjunctive role in the future treatment of MEE.

Different distribution of HLA class II alleles according to response to corticosteroid therapy in sudden sensorineural hearing loss

OBJECTIVE

To investigate the association of HLA class II alleles with the susceptibility to sudden sensorineural hearing loss and with the results of corticosteroid treatment in the Korean population.

DESIGN

HLA-DRB1, -DQA1, -DQB1, and -DPB1 genotyping by the sequence-specific oligonucleotide probes method in 41 patients with sudden sensorineural hearing loss and in 206 healthy control subjects. Initial hearing levels at the onset of hearing loss and final hearing levels after treatment were evaluated for the association with HLA class II alleles.

SETTING

Tertiary care referral center, ambulatory and hospitalized care.

SUBJECTS

Forty-one patients (24 men and 17 women; mean age, 49.2 years) were compared with 206 controls. Patients were divided into 2 groups according to their response to corticosteroid therapy (good response vs nonresponse).

RESULTS

The frequencies of HLA-DRB1, -DQA1, -DQB1, and -DPB1 alleles were not significantly different between patients and controls (P>.05). When an association between the results of corticosteroid treatment and the frequency of HLA alleles was evaluated, the frequencies of HLA-DRB1*14 (relative risk [RR] = 3.5, P<.02), -DQA1*03 (RR = 4.2, P<.02), and -DQA1*05 (RR = 3.1, P<.03) were significantly increased, but HLA-DQA1*01 (RR = 0.2, P<.004) and -DQB1*06 (RR = 0.2, P<.009) were decreased in the group nonresponsive to corticosteroid therapy, compared with the controls. The distribution of HLA-DQA1*01 (P<.04), -DQB1*06 (P<.02), and -DQA1*03 (P<.003) was significantly different between the responsive and the nonresponsive groups. HLA-DQA1 allelic combination analysis showed that the frequencies of DQA1*03 and *05 had a high RR value in patients with sudden sensorineural hearing loss (RR = 4.1, P<.003) and in patients in the nonresponsive group (RR = 8.9, P<.001), compared with the controls.

CONCLUSION

The presence of HLA class II alleles may be a useful genetic marker in forecasting a prognosis in Korean patients with sudden sensorineural hearing loss.

Effect of tumor necrosis factor-alpha on experimental otitis media with effusion

OBJECTIVES/HYPOTHESIS

Up to the present, many reports have demonstrated that local immune response is associated with maintenance and persistence of effusion in the middle ear cavity. Resulting retention of inflammatory cells and mediators in the middle ear results in ongoing effusion. The purpose of this study was to clarify the role of tumor necrosis factor in experimental otitis media with effusion, which was induced by transtympanic injection of tumor necrosis factor in the rats.

STUDY DESIGN

Four groups were designed in two experiments. The purpose of experiment 1 was to confirm that transtympanic injection of TNF-alpha produces the middle ear effusion. In experiment 2, TNFsolRI was used to evaluate the possibility as an inhibitor in otitis media with effusion.

METHODS

The histopathological changes were observed under light microscope, and the changes in microvascular permeability were examined using Evans blue vital dye technique.

RESULTS

Middle ear effusion was developed in 70% of specimens, and histopathological changes, such as subepithelial edema and marked infiltration of neutrophils, were present in 100% at 24 hours after administration of tumor necrosis factor-alpha through transtympanic approach. Extravasation of Evans blue dye was found in all specimens injected by tumor necrosis factor-alpha, which was qualified using a fluorescence microscope and quantified using a spectrophotometer. These histopathological findings and changes in microvascular permeability were significantly reduced by tumor necrosis factor soluble receptor type I.

CONCLUSIONS

Neutrophil infiltration, subepithelial edema, increased microvascular permeability, and resultant effusion were indirectly proved to be induced by tumor necrosis factor-alpha. We hope that this study may contribute to understanding the role of tumor necrosis factor-alpha in otitis media with effusion and clarifying the future role of tumor necrosis factor soluble receptor type I in preventing otitis media with effusion.

The clinical evaluations of pathophysiology for congenital middle ear cholesteatoma

PURPOSE

Congenital middle ear cholesteatoma (CMEC) is less common than the acquired variety. Many theories have been put forward to explain the pathophysiology of CMEC; however, none of them have been convincingly proven thus far. This clinical study was performed to analyze the case reviews; assess the characteristic features of CMEC, and evaluate the correlation between those features and the pathophysiology of CMEC.

METHODS

The medical records of patients who underwent otologic procedures at the hospitals of the Catholic University, Seoul, Korea, from January 1993 to November 1998 have been reviewed.

RESULTS

Of the 14 patients, 3 had cystic lesions isolated to the anterosuperior quadrant of the mesotympanum. The lesions were easy to remove and did not affect the patients' hearing. Eleven patients had more extensive disease with posterior mesotympanum involvement; the lesions were large, were often too extensive to indicate a formative site, and caused ossicular damage.

CONCLUSION

CMEC manifests in 2 distinctive forms according to the formation site. This distinctive formation site suggests that the pathophysiology of posterior lesions may be different from that of anterior ones. For early diagnosis of CMEC, a screening program should be established for children to prevent more extensive disease.

Obstetric admissions to the intensive therapy unit of a tertiary care institution

INTRODUCTION

Between 0.1% and 0.9% of women develop pregnancy complications which require admission to an intensive therapy unit. The aim of this study was to review all obstetric admissions to the intensive therapy unit at the KK Women's and Children's Hospital from 1998 to 1999 with respect to indications for admission, interventions employed and clinical outcome.

METHOD

The medical records of all obstetric patients admitted to the intensive therapy unit during the 2-year period were analysed retrospectively. Subjects were included if they were admitted during pregnancy up to 42 days postpartum.

RESULTS

There were 31,725 deliveries in our hospital during the study period of which there were 239 admissions to the intensive therapy unit. Of these, 42% were Malays, 41% Chinese, 12% Indians and 5% other races. 65% stayed 1 day, 24% 2 days, 7% 3 days and 4% more than 3 days. The patients' ages ranged from 18 to 44 years. The indications for admission were hypertension (50%), haemorrhage (24%), respiratory insufficiency (10%), neurological problems (11%) and sepsis (3%). Intervention-wise, 43% of patients required vasoactive infusions, 35% had arterial line placement, 22% central venous pressure monitoring, 21% ventilatory support and 2% pulmonary artery catheter placement. The maternal mortality and stillbirth rates were 1.3% and 3.7% of intensive therapy unit admissions, respectively.

CONCLUSION

The admission rate to the intensive therapy unit in our institution was 0.73% of all deliveries during the 2-year study period. Hypertensive disease and haemorrhage were the predominant admitting diagnoses.

Distribution of HLA-A, -B and -DRB1 alleles in patients with sudden sensorineural hearing loss

This study was performed to investigate the association between human leukocyte antigen (HLA) and susceptibility to sudden sensorineural hearing loss in the Korean population. HLA-A and HLA-B typing using a standard microlymphocytotoxicity technique and HLA-DRB1 genotyping were performed in 35 patients with sudden sensorineural hearing loss and in 206 healthy controls. Prednisone (usual dose 60 mg/day) was administered for 6 days and tapered for an additional 4-6 days. Both initial hearing levels at the onset of deafness and final hearing levels after treatment were examined and evaluated for association with HLA alleles. The frequency of HLA-DRB1*14 was increased in patients with sudden sensorineural hearing loss compared with controls (relative risk [RR] = 2.7, p = 0.016). The frequencies of HLA-A2, -A31, -B52, -B61, -DRB1*04, -DRB1*11 and -DRB1*12 were slightly higher than in the controls, but did not reach statistical significance. When an association between the treatment results and HLA alleles was also evaluated, the frequency of HLA-DRB1*04 was found to be increased in the patients who did not respond to steroid treatment compared with both patients who responded well to steroid (50%, vs 16%, p = 0.034) and controls (RR = 3.0, p = 0.046). These results suggest that there is an association between HLA-DRB1*14 and disease susceptibility and that the presence of HLA-DRB1*04 may be an useful marker for predicting a poor prognosis in Korean patients with sudden sensorineural hearing loss.

Effects of platelet-derived growth factor-AA on the healing process of tympanic membrane perforation

PURPOSE

Platelet-derived growth factor basic 30-kD disulfide-bonded dimer of A and B chains (PDGF-AA, PDGF AB, PDGF-BB) and a cytokine, promoting wound healing by its mitogenicity for fibroblast and by stimulating the production of fibronectin and hyaluronic acid. This article investigates the effect of PDGF on the healing process of tympanic membrane (TM) perforation.

MATERIALS AND METHODS

The pars tensa of the posterior aspect of the TM of rats was excised and treated with 2 microg of PDGF-AA or placebo. The animals were killed at 3, 5, 7, 9, 11, 15, and 28 days after operation. The healing process of TM perforation was observed with a telescope and light microscope. The temporal bones were also immunohistochemically examined for PDGF-alpha receptor (PDGF-R(alpha)) and fibronectin.

RESULTS

All PDGF-AA-treated TM were completely closed by 5 days after surgery, whereas some of the placebo-treated TM were not closed at 15 postoperative days. PDGF-AA induced the most prominent proliferation of the connective tissue by 9 postoperative days, after which the growth of the connective tissue decreased. By the 4th postoperative week, the PDGF-treated TM were slightly thicker than normal TM. An intense expression of fibronectin was detected in the connective tissue layer of the TM that were treated with PDGF-AA. PDGF-R(alpha) was expressed in the epithelial layer of both the PDGF-treated and control TM.

CONCLUSION

These results show that PDGF-AA speeds up the healing process of TM defect, improves the rate of healing, and prevents atrophic changes in the healed TM by promoting the connective tissue growth. The use of PDGF-AA can be an effective alternative to surgery for managing TM perforations.

Streptococcal toxic shock-like syndrome in a post-myomectomy patient

We report on a healthy 34-year-old woman who received an elective myomectomy for uterine fibroid, and postoperatively developed fatal streptococcal toxic shock-like syndrome. We discuss the series of events that led to this life-threatening disease and its pathophysiology, and suggest areas in which management might have been improved.

Sedation for the conduct of lumbar epidural anaesthesia: a study using subanaesthetic dose of ketamine in combination with midazolam

We gave sedation for the conduct of lumbar epidural analgesia using intravenous ketamine 0.3 mg.kg-1 with intravenous midazolam 2 mg. Forty adult Chinese females undergoing major gynaecological laparotomies had epidural catheter inserted before general anaesthesia, 20 of whom were given ketamine and midazolam (study group) and the other 20 acted as control. During the conduct of the epidural, the pain and anxiety scores in the study group were significantly less than the control group (P < 0.05). Patients were significantly more sedated in the study group (P < 0.05). All the patients in the study group were satisfied and would consent to future epidural versus 75% in the control group (significant at P < 0.05). Ninety per cent of patients in the study group had amnesia but none in the control group. Pain experienced during the epidural was the reason for refusal of future epidural. We did not observe any emergence phenomenon or cardiovascular stimulation. There was a statistically significant decrease in the pulse oximetry oxygen saturation (SpO2) in the study group but none required oxygen supplementation. We concluded that pain caused by the conduct of epidural did decrease the patient's acceptance rate to future epidural, and the combined use of intravenous ketamine 0.3 mg.kg-1 and midazolam 2 mg provided adequate sedation, analgesia, anxiolysis and amnesia to significantly increase the acceptance rate without any significant side effects.

Antigen diffusion from the perilymphatic space of the cochlea

The diffusion pattern of horseradish peroxidase (HRP) injected into the scala tympani of the cochlear basal turn of guinea pigs was studied to test whether antigen presented in this manner can gain access to the endolymphatic sac. By two hours, HRP reaction product was found throughout the cochlea, with the greatest amounts in the spiral ligament, spiral limbus, basilar membrane, and organ of Corti. In several cochleas, very weak labeling was seen in the stria vascularis. HRP reaction product was maximal in the basal turn. By two hours, HRP reaction product was also observed in the endolymphatic sac lumen, epithelial cells, subepithelial tissue, and perisaccular connective tissue. It was more common in the proximal portion. At this time, macrophages within the lumen already appeared to have phagocytosed the HRP. By 72 hours after injection, the inner ear was cleared of HRP. The results of this study support the hypothesis that antigen in the scala tympani gains access to the endolymphatic sac lumen, where it may be presented by macrophages to the systemic immune system. Antigen most likely does not gain access to the endolymphatic space in the cochlea, but it gets to the endolymphatic sac through the perilymph and the perisaccular tissue.

Continuous spinal analgesia--initial experiences with differential sensory block and labour pain relief

This report describes the use of microcatheters to provide continuous spinal analgesia for the relief of labour pain. Bupivacaine 0.025% was administered through a 28G spinal microcatheter resulting in a differential block which provided effective labour pain relief. Conduction by the smaller pain fibres from the uterus were blocked, while relatively sparing the larger A fibres. Motor power, sense of touch, and discrimination between blunt and sharp objects were therefore left relatively intact. Patients were thus spared the discomfort of motor paralysis and an intense sensory block. No patient had hypotension (blood pressure fall greater than 20%). However one patient suffered a severe post-dural puncture headache which required an epidural blood patch. Continuous intra-thecal spinal analgesia is a potential alternative to continuous epidural analgesia in the relief of labour pain.

General anaesthesia vs sedation for minor gynaecological procedures--a comparative study

Sedation using combined intravenous midazolam and fentanyl is a popular technique for minor gynaecological procedures. However, it is fraught with inconsistency in efficacy and has a greater tendency to perioperative oxygen desaturation. Fifty female ASA I patients scheduled for minor gynaecological procedures were given intravenous midazolam and fentanyl before surgery started. Intraoperative excessive movement that interfered with surgery and failure to maintain a patient airway were noted. Perioperative oxygen saturation was monitored with the pulse oximeter. In another group of 50 female ASA I patients, intravenous thiopentone was given and anaesthesia maintained with 67% nitrous oxide in 33% oxygen and 0.5% of isoflurane via a face mask. Results showed that 10% of the sedated patients had excessive movements that interfered with surgery, of which 6% needed a general anaesthetic. Twenty-two percent of the sedated patients needed maintenance of airway perioperatively. Perioperative oxygen desaturation was profound in incidence and degree in the sedated patients whereas no patient who received general anaesthesia desaturated. The perioperative incidence of desaturation in the sedated patients was 46%. Intraoperatively, 28% (p < 0.001) of the sedated patients had oxygen saturation in the range of 85 to 90% and 18% of them (p < 0.01) had oxygen saturation of less than 85%. Postoperatively 8% of the sedated patients had oxygen saturation of 85 to 90%. We conclude that general anaesthesia is more efficacious and safer than sedation in patients scheduled for minor gynaecological procedures. The same minimum standard of monitoring applied to general anaesthesia should be used for sedated patients.

Difficult intubation: a prospective study

Difficult intubation has been much discussed in the anaesthetic literature. The incidence of difficult intubation (11:560) was higher in obstetric patients (6:277) as compared to gynaecological patients (5:283) in our hospital. We tested the Mallampati's classification as a predictor of difficult intubation in 277 obstetric and 283 gynaecological patients. We recommend that Mallampati's classification can be used reliably (p less than 0.05) to predict difficult intubation in obstetric but not in gynaecological patients.