Dexamethasone treatment of murine auditory hair cells and cochlear explants attenuates tumor necrosis factor-α-initiated apoptotic damage

The most common cause of sensorineural hearing loss is damage of auditory hair cells. Tumor necrosis factor-alpha (TNF-α) is closely associated with sensorineural hearing loss. The present study examined the preconditioning effect of dexamethasone (DEX) on TNF-α-induced ototoxicity in mouse auditory hair cells (HEI-OC1) and cochlear explants. Treatment of HEI-OC1 with 10 ng/ml TNF-α for 24 h decreased cell viability, increased the accumulation of reactive oxygen species (ROS), and induced caspase-mediated apoptotic signaling pathways. Pretreatment with 10 nM DEX for 6 h before TNF-α exposure restored cell viability, decreased ROS accumulation, and attenuated apoptotic signaling activation induced by TNF-α. Incubation of cochlear explants with 20 ng/ml TNF-α for 24 h resulted in significant loss of both inner hair cells (IHCs) and outer hair cells (OHCs) and an increase in apoptotic activation accessed by annexin V staining. The cochlear explants pre-incubated with 10 nM DEX attenuated TNF-α ototoxicity in both IHCs and OHCs and apoptotic cell death. These results indicated that DEX plays a protective role in ototoxicity induced by TNF-α through attenuation of caspase-dependent apoptosis signaling pathway and ROS accumulation.

Prevalence of vestibular migraine in an otolaryngologic clinic: Preliminary clinical diagnosis versus diagnosis according to the strictly applied Bárány criteria

BACKGROUND

Diagnostic criteria of vestibular migraine (VM) by the Bárány classification consists of complex combinations of characteristics of dizziness: episodes, intensity, duration, migraine according to International Classification of Headache Disorders (ICHD), and migraine features accompanying vertigo. The prevalence according to strictly applied Bárány criteria may be much lower than preliminary clincal diagnosis.

OBJECTIVE

The purpose of this study is to investigate the prevalence of VM according to strictly applied Bárány criteria among dizzy patients who visited the otolaryngology department.

METHODS

The medical records of patients with dizziness from December 2018 to November 2020 were retrospectively searched using a clinical big data system. The patients completed a questionnaire designed to identify VM according to Bárány classification. Microsoft Excel function formulas were used to identify cases that met the criteria.

RESULTS

During the study period, 955 new patients visited the otolaryngology department complaining of dizziness, of which 11.6% were assessed as preliminary clinical diagnosis of VM in outpatient clinic. However, VM according to strictly applied Bárány criteria accounted for only 2.9% of dizzy patients.

CONCLUSION

The prevalence of VM according to strictly applied Bárány criteria could be significantly lower than that of preliminary clinical diagnosis in outpatient clinic.

Differential Involvement of Lateral Semicircular Canal and Otolith Organs in Common Vestibular Disorders

Semicircular canal and otolith functions came to be evaluated recently, but comprehensive and comparative analysis of canal and otolith dysfunction in common vestibular disorders is lacking. We aimed to analyze the abnormal rates of canal and otolith function in common vestibular disorders. We enrolled 302 patients who were managed for 2 months in a dizziness clinic. Results of caloric, video head impulse test (vHIT), and cervical and ocular vestibular evoked myogenic potential (cVEMP and oVEMP) tests were analyzed and compared among various diagnoses. Vestibular disorders diagnosed included recurrent vestibulopathy (RV, 27%), vestibular migraine (VM, 21%), benign paroxysmal positional vertigo (BPPV, 17%), Meniere's disease (MD, 11%), vestibular neuritis (VN, 10%), orthostatic dizziness (7%), and central lesions (3%). Lateral canal dysfunction was found most in VN (100%) and less commonly in definite MD (75%), RV (46%) and definite VM (29%). Abnormal caloric results were more common than abnormal vHIT in all disorders. Otolith dysfunction was found more frequently than lateral canal dysfunction in most vestibular disorders except VN. An abnormal cVEMP was more frequent in definite MD than the other disorders. Isolated otolith dysfunction without lateral canal dysfunction was the most found in BPPV, followed by definite VM, RV, and definite MD in decreasing order. Various patterns of involvement in canal and otoliths were revealed in vestibular disorders, suggesting different pathogenesis.

Postoperative results of ventilation tube insertion: a retrospective multicenter study for suggestion of grading system of otitis media with effusion

Background

In otitis media with effusion (OME), it is important to know when to surgically intervene and when careful monitoring is more appropriate. This study aimed to visualize and classify the clinical manifestations of OME and the correlation between the new grading system and postoperative results after ventilation tube insertion (VTI).

Methods

We classified the collective 1,012 ears from 506 patients into six groups: grade 0 (no effusion), grade I (scant effusion, but abnormal), grade II (effusion less than half of the tympanic cavity), grade III (effusion over half of the tympanic cavity, with air bubbles), grade IV (complete effusion), and grade V (retracted tympanic membrane or hemotympanum without air bubbles).

Results

The mean age at VTI was 5.2 (±2.9) years and mean duration between diagnosis and operation was 4.1 (±1.8) months. Between the grades, the nature of the middle ear effusion was also significantly different (p < 0.001). The duration of ventilation tube retention after VTI was significantly different when compared between two groups: grade I-IV and grade V (p = 0.019). Our results showed that the recurrence rate, as well as rate of revision VTI, increased as the grade increased (p < 0.001).

Conclusions

The new grading system of OME using endoscopic otoscope evaluation had a significant correlation with the age at VTI, the nature of middle ear effusion, the recurrence rate of OME, and the rate of revision VTI.

Hearing Outcomes of Stapes Surgery in Children With Stapes Fixation and Ossicular Anomalies

OBJECTIVES

To investigate hearing outcomes after stapes surgery in children with stapes fixation.

STUDY DESIGN

Retrospective study.

SETTING

Tertiary referral center.

PATIENTS

Forty-nine patients (66 ears) aged less than 15 years who received stapes surgery.

INTERVENTIONS

Stapes surgery.

MAIN OUTCOMES AND MEASURES

Preoperative symptoms, bilateral involvement, pure-tone hearing levels, and perioperative complications were analyzed using paired t test and Mann-Whitney U test.

RESULTS

The chief complaint of all patients was hearing disturbance. Sixteen ears were diagnosed with stapes fixation and an additional congenital ossicular anomaly and 50 ears had only stapes fixation. Preoperative mean bone conduction and air conduction thresholds were 12.0 ± 5.8 dB and 60.9 ± 10.9 dB, respectively. The mean air-bone gap (ABG) was 48.9 ± 12.0 dB in patients with stapes fixation and an ossicular anomaly. The postoperative mean ABG was 23.6 ± 14.5 dB, and the ABG closure was 25.3 ± 18.2 dB. In patients with stapes fixation only, the preoperative mean bone conduction and air conduction thresholds were 14.3 ± 7.5 dB and 49.6 ± 9.5 dB, respectively, and the mean ABG was 35.5 ± 9.6 dB. The postoperative mean ABG was 14.4 ± 10.3 dB, and the ABG closure was 16.2 ± 16.1 dB. The successful results (ABG <20 dB) were 75.8% overall, 56.3% for fixation and an ossicular anomaly, and 82.0% for fixation only.

CONCLUSIONS

In children with stapes fixation, hearing loss was worse when the fixation was combined with an ossicular anomaly. Ossicular continuity, especially of the incus, is the most important factor for successful stapes surgery. Appropriate diagnosis and surgical intervention can lead to good results for children with stapes fixation.

T1-Staging for Urinary Bladder Cancer with the Stalk and Inchworm Signs with 3.0 Tesla MRI

Purpose

To evaluate the diagnostic utility of the stalk and the inchworm sign on preoperative MRI for detecting superficial bladder cancers, and to compare the diagnostic performance between the stalk and the inchworm sign.

Materials and Methods

We retrospectively reviewed 240 patients (505 tumors) who had undergone radical cystectomy. The tumors were classified as follows: superficial or invasive tumors indicated by the stalk or inchworm sign on 3.0 Tesla MRI. We evaluated the diagnostic accuracy of the stalk and inchworm signs, by comparing each finding with the postoperative pathologic T stage. We compared diagnostic performance between them statistically.

Results

The stalk and inchworm signs showed high specificity (93% and 91%, respectively), positive predictive values (89% and 90%, respectively), and acceptable accuracy (70% and 74%, respectively), but low sensitivity (54% and 61%, respectively) and negative predictive values (60% and 63%, respectively). There was no statistically significant difference between the two signs (p > 0.05).

Conclusion

Superficial bladder cancers could be differentiated from invasive tumors using the stalk or inchworm sign on MRI.

Changes in Cortical Auditory Evoked Potentials by Ipsilateral, Contralateral and Binaural Speech Stimulation in Normal-Hearing Adults

Objectives

Cortical auditory evoked potentials (CAEPs) have been used to examine auditory cortical development or changes in patients with hearing loss. However, there have been no studies analyzing CAEP responses to the different sound stimulation by different stimulation sides. We characterized changes in normal CAEP responses by stimulation sides in normal-hearing adults.

Methods

CAEPs from the right auditory cortex were recorded in 16 adults following unilateral (ipsilateral and contralateral) and bilateral sound stimulation using three speech sounds (/m/, /g/, and /t/). Amplitudes and latencies of the CAEP peaks in three conditions were compared.

Results

Contralateral stimulation elicited larger P2-N1 amplitudes (sum of P2 and N1 amplitudes) than ipsilateral stimulation regardless of the stimulation sounds, mostly due to the larger P2 amplitudes obtained, but elicited comparable P2-N1 amplitudes to bilateral stimulation. Although the P2-N1 amplitudes obtained with the three speech sounds were comparable following contralateral stimulation, the /m/ sound elicited the largest P2-N1 amplitude in ipsilateral stimulation condition due to the largest N1 amplitude obtained, whereas /t/ elicited larger a P2-N1 amplitude than /g/ in bilateral stimulation condition due to a larger P2 amplitude.

Conclusion

Spectrally different speech sounds and input sides are encoded differently at the cortical level in normal-hearing adults. Standardized speech stimuli, as well as specific input sides of speech, are needed to examine normal development or rehabilitation-related changes of the auditory cortex in the future.

Changes of video head impulse test results in lateral semicircular canal plane by different peak head velocities in patients with vestibular neuritis

BACKGROUND

The peak head velocity influences on the video head impulse test (vHIT) results, but it has been not known how much the difference is.

AIMS

To evaluate the clinical evidence for the superiority of high-velocity compared to low-velocity vHIT.

MATERIAL AND METHODS

vHIT was performed in 30 patients with vestibular neuritis using two peak head velocities (mean 80 vs. 240°/s). vHIT gains and parameters of corrective saccades (CSs) were compared. A vHIT gain of ≤0.8 or a peak CS velocity of ≥100°/s was considered pathologic.

RESULTS

The vHIT gains were significantly lower (mean 0.5 vs. 0.6), and GA was larger (35 vs. 25%) at high-velocity vHIT, compared to low-velocity vHIT. CSs were significantly more frequent (100 vs. 80%) and peak CS velocities were larger (252 vs. 112°/s) at high-velocity vHIT. The abnormal rates based on vHIT gains were higher (90% vs. 73%) and CSs occurred more frequently (100% vs. 80%) at high-velocity vHIT. The abnormal rates based on the peak CS velocity were significantly higher at high-velocity vHIT (100% vs. 57%).

CONCLUSION

High-velocity vHIT is superior to low-velocity vHIT with a difference of 17-20% based on pathologic vHIT gains and presence of CSs.

Prognostic roles of preoperative CT findings and air-bone gaps in type 1 tympanoplasty

BACKGROUND

Although CT has been used widely, the role of preoperative CT findings including other factors in tympanoplasty has not been elucidated comprehensively.

AIMS/OBJECTIVES

To evaluate relationship of CT findings with other factors and audiological results in type 1 tympanoplasty.

MATERIAL AND METHODS

A cohort of consecutive 175 patients with type 1 tympanoplasty was enrolled. Addition of mastoidectomy was based on the presence of soft tissue in antrum on CT. Postoperative air-bone gap (ABG) and reperforation rate were analyzed.

RESULTS

Positive soft tissue in antrum on CT was found in 52 (29.7%) patients and showed larger preoperative ABG than the negative group. Successful ABG closure (≤20 dB) was obtained in 97% when preoperative ABG ≤20 dB, but it decreased as the preoperative ABG increased (83% with preoperative ABG of 21-30 dB, and 0% with preoperative ABG >30 dB). Postoperative reperforation rate was positively related to the preoperative ABG, but not the presence of soft tissue in the antrum, the size, or locations of preoperative perforations.

CONCLUSIONS AND SIGNIFICANCE

Our findings showed that temporal bone CT was helpful in determining addition of mastoidectomy and the presence of soft tissue in the antrum was associated with large ABG.

Fluoroscopic balloon diameter measurement at different pressures during Eustachian balloon dilation

OBJECTIVES

To measure the diameter of inflated balloons at different pressures during Eustachian tube (ET) balloon dilation under fluoroscopic guidance.

DESIGN

Prospective cohort study.

SETTING

Tertiary academic referral centre.

PARTICIPANTS

Eighteen patients who underwent ET balloon dilation with use of a balloon catheter, 20 mm long and 6 mm in diameter, under combined endoscopic and fluoroscopic guidance.

MAIN OUTCOME MEASURES

Degrees of inflation at three different portions (proximal, middle and distal) of the balloon at controlled pressures (3, 5, 8 and 10 atmospheres [atm]) and at the maximum pressure manually applied.

RESULTS

The mean proximal, middle and distal diameters of the inflated balloons were 5.3 ± 0.4 mm, 5.3 ± 0.4 mm and 4.9 ± 0.5 mm at 10 atm. The distal diameters were significantly smaller than middle and proximal diameters at all the pressures (P < 0.01). When compared to the distal diameter (100%, 4.9 ± 0.5 mm) at 10 atm, the distal diameters were 73% (3.6 ± 0.6 mm) at 3 atm, 88% (4.3 ± 0.5 mm) at 5 atm and 96% (4.7 ± 0.4 mm) at 8 atm. The distal diameter (4.1 ± 0.3 mm) at the maximum pressure manually applied was in between those at 3 and 5 atm.

CONCLUSIONS

The distal diameter of the balloon increased significantly as a function of the pressure and most (88%) inflation occurred at a low pressure of 5 atm, which was sufficient to inflate the distal diameter of the balloon more than 3 mm. The manual pressurisation could inflate a balloon by as much as could be expected, at between 3 and 5 atm.

Diagnostic Value of Gains and Corrective Saccades in Video Head Impulse Test in Vestibular Neuritis

Objectives We investigated changes in video head impulse test (vHIT) gains and corrective saccades (CSs) at the acute and follow-up stages of vestibular neuritis to assess the diagnostic value of vHIT. Study Design Case series with chart review. Setting Tertiary medical center. Subjects and Methods Sixty-three patients with vestibular neuritis who underwent vHIT at an initial presentation and an approximately 1-month follow-up were included. vHIT gains, gain asymmetry (GA), peak velocities of CS, and interaural difference of CS (CSD) were analyzed. Results Mean vHIT gains increased significantly from the acute stage to the follow-up exam. The mean GA, peak velocities of CS, and CSD had decreased significantly at the follow-up. The incidence of CSs was also significantly decreased at the follow-up. The abnormal rate (87%) considering both gain and CS value was significantly higher than that (62%) considering vHIT gain only at the follow-up, although the abnormal rates did not differ at the acute stage (97% vs 87%). Conclusion The abnormal rates based on both vHIT gains and CS measurements are similar at the acute stage of VN but are considerably higher at the follow-up stage compared with the abnormal rates based on vHIT gains alone. It is thus advisable to check both CS and vHIT gain while performing vHIT to detect vestibular hypofunction.

Large Sternocleidomastoid Haematoma after Minor Trauma in a Postradiation Neck

Sternocleidomastoid (SCM) muscle haematoma after minor blunt injury is rare. Radiation therapy as a treatment for head and neck tumours e.g. nasopharyngeal cancer can result in complications, including fibrosis, scarring, and atrophy. We report a 51-year-old man suffering from massive haematoma of SCM muscle after minor blunt injury to a postradiation neck. Signs of haematoma were absent during his first visit to the emergency department. Emergency physicians need to be aware that bleeding from a postradiation neck, even after minor trauma, may be life threatening.

Highly Enantioselective Hydrosilylation of Ketones Catalyzed by a Chiral Oxazaborolidinium Ion

A highly enantioselective hydrosilylation of ketones was developed for the synthesis of a variety of chiral secondary alcohols. In the presence of a chiral oxazaborolidinium ion (COBI) catalyst, the reaction proceeded with good yields (up to 99%) with excellent enantioselectivities (up to 99% ee).

Catalytic Asymmetric Roskamp Reaction of Silyl Diazoalkane: Synthesis of Enantioenriched α-Silyl Ketone

A catalytic enantioselective Roskamp reaction of silyl diazoalkane to synthesize a highly optically active α-silyl ketone from aldehydes is described. In the presence of a chiral oxazaborolidinium ion catalyst, the reaction provides α-chiral silyl ketones with good yields (up to 97%) and high enantioselectivities (up to >99% ee). In addition, a one-pot procedure using an asymmetric Roskamp/reduction strategy gives highly optically active syn-β-hydroxysilane in good yields (up to 94%) with high enantioselectivities (up to 99% ee) and syn stereoselectivities (>20:1).

Quantitative analysis of gains and catch-up saccades of video-head-impulse testing by age in normal subjects

OBJECTIVES

To evaluate video-head-impulse test (vHIT) results in normal subjects, to determine the normative values of vHIT for the vestibulo-ocular reflex (VOR) and to characterise the catch-up saccades (CSs).

DESIGN

Prospective cohort study.

SETTING

Tertiary care academic referral centre.

PARTICIPANTS

Fifty healthy subjects with no history of vestibular impairment, ten each in their 20's, 30's, 40's, 50's and 60's, underwent vHITs in the lateral semicircular canal plane.

MAIN OUTCOME MEASURES

vHIT gains and the incidence and amplitudes of covert and overt CSs.

RESULTS

The mean vHIT gain was 1.02 ± 0.07, and the mean gain asymmetry was 2.39 ± 1.96%, with no significant differences among age groups. CSs were observed during 22.6% of the trials and in 49% of the ears. The incidence of CSs was not associated with age. The mean velocity of CSs was 55.5 ± 16.9°/s, and its mean interaural difference was 11.8 ± 10.7°/s.

CONCLUSIONS

vHIT gains were consistently equal to 1.0 in all age groups (20's to 60's), suggesting that abnormal criteria for vHIT gain (e.g. 0.8) and gain asymmetry (e.g. 8%) can be used, regardless of age. CSs were observed in about half of normal ears, suggesting that VOR is a hypometric system. The amplitudes and interaural difference of CSs were also similar in all age groups, suggesting that abnormal criteria for CS amplitude (e.g. 100°/s) and interaural difference (e.g. 40°/s) can be used, regardless of age.

Management of 210 patients with benign paroxysmal positional vertigo: AMC protocol and outcomes

CONCLUSION

Benign paroxysmal positional vertigo (BPPV) could be treated with specific maneuvers for the involved canals. Management on a daily basis gave earlier relief than weekly treatment, especially in apogeotropic BPPV. Apogeotropic and multi-canal BPPVs were related to the increased numbers of follow-ups and trauma was related to the increased recurrence.

OBJECTIVE

We aimed to report the short-term outcomes of our protocol for BPPV and evaluate the factors influencing the results and recurrence.

METHODS

In 210 BPPV patients, posterior semicircular canal (PSCC), geotropic and apogeotropic lateral canal BPPVs were treated with the Epley maneuver, barbecue maneuver, and barbecue maneuver after head-shaking. The total number of follow-ups needed to have no provoked nystagmus, success rates at 1 week and 1 month, and factors for repeated maneuvers or recurrence were identified.

RESULTS

Apogeotropic and multi-canal BPPV needed more follow-ups than PSCC BPPV. Multi-canal BPPV showed a significantly lower 1-week success rate than other types. Anterior and multi-canal BPPV showed significantly lower 1-month success rates than other types. The 1-week success rates for PSCC and geotropic and apogeotropic BPPV in patients followed up on a daily basis were higher than those in patients with weekly follow-up and the difference was significant only in apogeotropic BPPV. The overall 1-year recurrence rate was 16% and higher recurrence rate was related to trauma.

Candidates for limited lateral neck dissection among patients with metastatic papillary thyroid carcinoma

BACKGROUND

Papillary thyroid carcinoma (PTC) is associated with an excellent prognosis but frequently spreads to regional lymph nodes. The extent of neck dissection, particularly routine level II or V lymphadenectomy, is still controversial as it may lead to spinal accessory nerve injury and associated postoperative morbidities. We assessed the diagnostic value of preoperative ultrasonography (US) plus computed tomography (CT) for detecting metastatic lymph nodes and for identifying predictors of level II or V metastasis in patients with PTC.

METHODS

The results of US and CT were compared with histopathologic findings at various neck levels in 209 previously untreated PTC patients with lateral cervical nodal metastases who underwent total thyroidectomy with central and lateral neck dissection. Clinicopathologic predictors for level II or V metastases were identified.

RESULTS

Pathologic metastases to level II and V were observed in 53.6 and 25.4 % of patients, respectively. Occult metastases were found in 34.5 and 16.8 %, respectively. The sensitivities of US plus CT for levels II and V were 64.6 and 50.9 %, respectively. Image-based, isolated lateral level IV involvement and macroscopic extranodal extension were independently associated with level II metastasis or either level II or V metastasis (p < 0.01). Macroscopic extranodal extension was also independently associated with level V metastasis (p = 0.001).

CONCLUSIONS

Patients with image-based, isolated lateral level IV involvement and no macroscopic extranodal extension are potential candidates for limited level III-IV dissection or prophylactic level II lymphadenectomy omission. Level V lymphadenectomy may be omitted in patients without macroscopic extranodal extension.

Middle ear surgery in only hearing ears and postoperative hearing rehabilitation

Background and Objectives

The aim of this study was to evaluate surgical interventions and hearing rehabilitation in patients with chronic middle ear disease of only hearing ears.

Subjects and Methods

Thirty-one patients with chronic middle ear disease of only hearing ears were enrolled in this retrospective study. Patients were classified into three groups according to the hearing level: groups A [pure tone audiometry (PTA)<40], B (40≤PTA<70), and C (PTA≥70). We evaluated hearing results and patterns of auditory rehabilitation.

Results

The main consideration for a surgical procedure was the presence of recurrent otorrhea and structural destruction. The reasons for surgical intervention in only hearing ears were otorrhea caused by chronic otitis media (68%), cholesteatoma (29%), and cholesterol granuloma (3%). The causes of contralateral deaf ears were chronic otitis media (81%) and sensorineural hearing loss (19%). Although there was hearing deterioration in some patients with severe hearing loss (PTA≥70), all patients achieved dry ears after surgery and functional hearing using auditory rehabilitation. Hearing aids were used in most patients with moderate to moderately severe hearing loss and cochlear implants were used for auditory rehabilitation in patients with severe to profound hearing loss.

Conclusions

Proper evaluation and indications for surgery in only hearing ears are important for successful eradication of inflammation and hearing preservation. Surgical interventions can achieve dry ear and enable further auditory rehabilitations using hearing aids and cochlear implantation.

Contrast-induced nephropathy in patients undergoing intravenous contrast-enhanced computed tomography in Korea: a multi-institutional study in 101487 patients

Objective

To evaluate the prevalence of known risk factors for contrast-induced nephropathy (CIN) and their association with the actual occurrence of CIN in patients undergoing intravenous contrast-enhanced computed tomography (CECT) in Korea.

Materials and Methods

Patients who underwent CECT in 2008 were identified in the electronic medical records of 16 tertiary hospitals of Korea. Data on demographics, comorbidities, prescriptions and laboratory test results of patients were collected following a standard data extraction protocol. The baseline renal function was assessed using the estimated glomerular filtration rate (eGFR). We identified the prevalence of risk factors along the eGFR strata and evaluated their influence on the incidence of CIN, defined as a 0.5 mg/dL or 25% increase in serum creatinine after CECT.

Results

Of 432425 CECT examinations in 272136 patients, 140838 examinations in 101487 patients met the eligibility criteria for analysis. The mean age of the participants was 57.9 ± 15.5 years; 25.1% of the patients were older than 70 years. The prevalence of diabetes mellitus was 11.9%, of hypertension 13.7%, of gout 0.55% and of heart failure was 1.7%. Preventive measures were used in 40238 CECT examinations (28.6%). The prevalence of risk factors and use of preventive measures increased as the renal function became worse. A CIN was occurred after 3103 (2.2%) CECT examinations, revealing a significant association with decreased eGFR, diabetes mellitus, and congestive heart failure after adjustment.

Conclusion

Risk factors for CIN are prevalent among the patients undergoing CECT. Preventive measures were seemingly underutilized and a system is needed to improve preventive care.

An assessment of oropharyngeal airway position using a fibreoptic bronchoscope

Selecting the appropriate oropharyngeal airway for safe and effective airway management is important in clinical practice. In this prospective observational study, we examined the position of the distal end of oropharyngeal airways using a fibreoptic bronchoscope. We enrolled 149 adults (72 men and 77 women). The correct airway size was determined by inserting four adult sizes Guedel airway (Hudson RCI; Teleflex Medical, Research Triangle, Park, NC, USA) (sizes 8, 9, 10 and 11) sequentially in anaesthetised patients. The 'best fit' airway was size 10 in 45 (62%) men, and size 9 in 58 (75%) women. However, when these airways were inserted, the distal end of the airway either touched or passed beyond the epiglottis tip in 20 (27%) men and six (8%) women, respectively. When a size-9 airway was inserted in men and a size-8 airway inserted in women, the distal ends were obstructed by the tongue in three (2%) patients. In conclusion, a size-9 airway in men and a size-8 airway in women are the most acceptable sizes for adults of average height.

Surgically resected gastric metastasis of pulmonary squamous cell carcinoma

Gastric metastasis of pulmonary carcinoma has been reported to range from 0.19%-5.1%. An autopsy review of cancer disclosed 1.7%-29.6% of gastric metastases, primarily from breast cancer, lung cancer and melanoma. A 71-year-old man was referred to our department because of persistent cough, sputum and sweating for 20 d. Chest posteroanterior view and chest computed tomography scan demonstrated an irregular tumor mass measuring 5.8 cm with central necrosis at the right lower lung. Bronchoscopic biopsy revealed pulmonary squamous carcinoma. Esophagogastroduodenoscopy revealed a huge bleeding ulcer at the body of the stomach and a biopsy diagnosed a metastatic lesion. We performed a palliative total gastrectomy, splenectomy and distal pancreatectomy. The patient did not receive any adjuvant chemotherapy due to his refusal. He was controlled conservatively and survived for 11 mo after surgery. Surgical resection may provide an option for safe palliative treatment. Although gastric metastasis from lung cancer is associated with dismal outcomes, a longer survival or more favorable outcome has been demonstrated in patients undergoing palliative surgical resection of the metastatic site. Considerable improvements in the understanding of metastatic diseases and therapeutic strategies are needed to improve the clinical outcome.

Proportion of bony cochlear nerve canal anomalies in unilateral sensorineural hearing loss in children

OBJECTIVE

The aim of this study was to characterize the various bony anomalies of the inner ear in patients with unilateral sensorineural hearing loss using high-resolution temporal bone computed tomography and establish the relationship between hearing and the diameter of the bony cochlear nerve canal.

METHODS

We performed a retrospective review of 51 patients (mean age 11 years, range 0-20 years, 27 boys, 24 girls) who were diagnosed with unilateral sensorineural hearing loss with an audiogram. Coronal and axial diameter of the inner ear structures, including the internal auditory canal, bony cochlear nerve canal, and each turn of the cochlea and semicircular canals, were measured with high-resolution temporal bone computed tomography. The mean values (± 2 standard deviations) were calculated and compared between sensorineural hearing loss and normal ears, and between narrow bony cochlear nerve canal and normal bony cochlear nerve canal ears. Bony cochlear nerve canal atresia/stenosis was defined as a value less than 1.4mm in axial images.

RESULTS

The diameter of the bony cochlear nerve canal was significantly smaller in sensorineural hearing loss ears than in normal ears (p<.05). Associated inner ear anomalies, such as IAC stenosis (24%), cochlear hypoplasia (7-17%), and narrow semicircular canal bony island (8%) were only observed in the narrow bony cochlear nerve canal group. This group also showed statistically significant, severe to profound hearing loss compared to the normal bony cochlear nerve canal group (p<.05, R(2)=12.8%).

CONCLUSIONS

Most (57%) of the unilateral sensorineural hearing loss ears had bony cochlear nerve canal stenosis/atresia and this group showed associated inner ear anomalies. When the diameter of the bony cochlear nerve canal was less than 1.4mm, pure tone audio averages were more than 70 dB HL in most ears.

A newly designed Y-shaped covered stent in the palliative treatment of hepatic hilar malignant obstruction: case report

We report a case in an inoperable patient with the hilar malignant biliary obstruction treated palliatively by the use of a newly designed Y-shaped covered stent without interfering contra-lateral bile duct. We percutaneously inserted a newly designed Y-shaped covered stent into a biliary tree in an inoperable patient with Bismuth Type II cholangiocarcinoma. We checked tubograms, enhanced CT studies, and blood bilirubin levels before, one week after, and at every three month after the stenting, by observing closely the signs of clinical infection as well. The follow-up period was about 12 months. The placement of the Y-shaped covered stent was successful and resulted in adequate biliary drainage in the immediate post-procedural tubogram and in the follow-up abdominal CT. The serum bilirubin levels did not show elevation after the insertion of the Y-shaped covered stent.

Superior canal dehiscence patients have smaller mastoid volume than age- and sex-matched otosclerosis and temporal bone fracture patients

Background and Objectives

The purpose of the study was to compare the mastoid air-cell volume of the patients with superior semicircular canal dehiscence syndrome (SCDS) and that of the control patients with otosclerosis and temporal bone (TB) fracture.

Subjects and Methods

Ten patients with SCDS were enrolled and 10 patients with bilateral otosclerosis and TB fracture were selected as control groups by age and sex matching. To measure the mastoid air-cell volume, 3D reconstruction software was used.

Results

In 10 patients with SCDS, the mean age was 44.5 years, ranging from 16 to 79 years (M : F=4 : 6). Mean mastoid air-cell volume in the SCDS side was 3319.9 mm³, whereas 4177.2 mm³ in the normal side (p=0.022). Mean mastoid air-cell volume in the right side of otosclerosis patients was 6594.3 mm³ and it was not different from 6380.5 mm³ in the left side (p=0.445). Mean mastoid air-cell volume in normal side of TB fracture was 6477.2 mm³. The mastoid air-cell volume in the SCDS side was significantly smaller than that of otosclerosis and TB fracture patients (p=0.009, p=0.002, respectively). The mastoid air-cell volume in the normal side of SCDS was significantly smaller than that of TB fracture (p=0.019), but not significant with that of otosclerosis (p=0.063).

Conclusions

Our findings revealed that the mastoid air-cell volume in the SCDS side was significantly smaller than control group, which suggest that the decreased mastoid pneumatization is closely related to the generation of SCDS.

The primary patency of percutaneous transluminal angioplasty in hemodialysis patients with vascular access failure

Background and Objectives

Dysfunction of arteriovenous fistulas (AVFs) and arteriovenous grafts (AVGs) contributes significantly to morbidity and hospitalization in the dialysis population. We evaluated the primary patency of AVFs following percutaneous transluminal angioplasty (PTA) in haemodialysis patients.

Subjects and Methods

We performed 231 interventions in 118 patients with a mean age of 62.1±12.9 years. We performed 122 interventions in 53 AVG patients (44.9%), and 109 interventions in 65 AVF patients (55.1%). If there was thrombosis of the vascular access, urokinase was administered and/or thrombus aspiration was performed. The stent was inserted when balloon dilatation did not expand sufficiently or elastic recoil occurred.

Results

For the 118 patients, the median patency time was 10.45±10.29 months at 92 months of follow-up. The primary patencies for stenotic AVFs at 6, 12, 24, 36, 48, and 60 months were 63.4%, 41.4%, 17.0%, 9.7%, 7.3%, and 2.4%, respectively. The primary patencies for AVGs at 6, 12, 24, and 36 months were 36.9%, 19.5%, 10.8%, 2.1%, respectively, and were obtained by means of the Kaplan-Meier analysis (log rank=6.42, p<0.05). The median patency time was 11.0 months and 4.45 months in the non-thrombus and thrombus groups, respectively. The complication rate was 1.73% (4/231); two cases of pseudoaneurysms and two cases of extravasation were detected. All therapy failures (5/231) occurred in thrombotic lesions of AVGs and were treated surgically.

Conclusion

PTA is an efficacious method for the correction of stenosis of AVFs for hemodialysis, thus prolonging the patency of the fistulas.

Cubic SiC nano-thin films and nano-wires: high vacuum metal-organic chemical vapor deposition, surface characterization, and application tests

Single-crystalline and epitaxial cubic silicon carbide (beta-SiC) nano-thin films have been deposited on Si(100) substrates at a sample temperature of approximately 900 degrees C using single source precursors by the thermal metal-organic chemical vapor deposition (MOCVD) method. Diethylmethylsilane and 1,3-disilabutane, which contain Si and C atoms in the same molecule, were used as precursors without any carrier or bubbler gas. Upon increasing the deposition temperature from 900 to 950 degrees C, beta-SiC nano-thin films with relatively small crystals and smoother surfaces were created on Si(100) substrates. Moreover, beta-SiC nano-wires with 40 approximately 100 nm in diameter have also been grown selectively on nickel catalyzed Si(100) substrates with dichloromethylvinylsilane by the MOCVD method. The deposition temperature in this case was as low as 800 degrees C under the pressure of 5.0 x 10(-2) Torr. It is worth noting that the initial growth rates of deposited beta-SiC nano-thin films and nano-wires strongly depend on the deposition temperature rather than the time. In order to test the possibility of applications of these materials for electronic components such as field emitter, MEMS, and high-power transistor, we fabricated the nanoelectronic devices using both beta-SiC nano-wires and nano-thin films. With these preliminary application tests, it is expected that SiC nanowires can be used as field emitter and nanoelectronic high-power transistor, and application of the SiC nano-thin films to MEMS is promising as well.

Evaluation of preoperative sonography in acute cholecystitis to predict technical difficulties during laparoscopic cholecystectomy

PURPOSE

The aim of this study was to evaluate the role of preoperative sonography in predicting technical difficulties during laparoscopic cholecystectomy in patients with acute cholecystitis.

METHODS

Sonographic assessment of 14 parameters was performed in 55 patients during a 9-month period: volume of gallbladder (GB), thickness of GB wall, pattern of GB wall thickening, size of largest gallstone, gallstone mobility, adhesion of GB to its bed, fat plane between GB and hepatoduodenal ligament, free fluid in GB fossa, common bile duct (CBD) dilatation, CBD stone(s), color and power Doppler signals in GB wall, and increased color and power Doppler signals in adjacent liver. Each of the 5 operative steps of laparoscopic cholecystectomy was scored as being difficult (1) or not (0). The scores for each step were added to obtain the overall difficulty score (0-5). We evaluated prospectively whether there were significant associations among the preoperative sonographic findings and the overall difficulty score, scores for each of the 5 operative steps, and operation time.

RESULTS

The overall difficulty score was significantly associated with a GB volume of 50 cm(3) or more, GB wall thickness of 3 mm or more, and presence of color Doppler signals in the GB wall. Increased GB volume also made dissection of adhesions from the GB and dissection of Calot's triangle more difficult. Extraction of the GB from the abdomen was more difficult with a thickened GB wall or adhesion of the GB to its bed. The presence of a CBD stone, dilatation of the CBD (> or = 8 mm), color Doppler signals in the GB wall, and increased power Doppler signals in the adjacent liver were significantly associated with increased operation time.

CONCLUSIONS

Based on our experience, preoperative determination of GB volume, GB wall thickness, and presence of color Doppler signals in the GB wall in patients with acute cholecystitis helps predict technical difficulties during laparoscopic cholecystectomy.

High-performance liquid chromatographic analysis and pharmacokinetics of terazosin in healthy volunteers

A high-performance liquid chromatographic (HPLC) analysis of terazosin in 1 ml of human plasma was developed using prazosin as an internal standard. The plasma sample was extracted with dichloromethane and ethylether and a 100-microl aliquot was injected onto the reversed-phase column. The mobile phase, 0.02 M sodium phosphate buffer:acetonitrile:tetrahydrofuran = 720:220:60 (v/v/v), was run at a flow rate of 0.8 ml/min and the column effluent was monitored using a florescence detector set at 370 and 250 nm for the emission and excitation wave numbers, respectively. The retention times for terazosin and prazosin were approximately 6.4 and 9.8 min, respectively, and the coefficients of variation of terazosin were generally low, below 6.4%. The present HPLC method was successful for the pharmacokinetic study of terazosin in healthy volunteers. Following oral administration of terazosin, 2 mg, to 20 healthy male volunteers, the area under the plasma concentration-time curve from time zero to time infinity was 421 +/- 71.8 ng h/ml and terminal half-life was 9.83 +/- 1.29 h.

A comparative study on cockroach and ovalbumin sensitizations and challenge responses in Hartley guinea-pigs

The role of allergens in asthmatic inflammation is not clearly understood. To elucidate the mechanism of cockroach allergen (CRa)-induced airway disease, we studied three groups of Hartley guinea-pigs sensitized to control, ovalbumin (OA) or CRa. Parameters measured were anaphylactic antibodies by allergy skin test (AST), PCA assay and Western blot, changes in specific airway resistance (SRaw), analysis of bronchoalveolar lavage (BAL) and contracture responses of tracheal muscle (TSM) to non-specific and specific stimuli, in vitro. Both OA and CRa animals showed a similar allergic sensitization (AST and PCA), while Western blot identified several reaginic bands in CRa group compared to a single band in OA group. SRaw illustrated that CRa induce dual-asthmatic responses (4/6) in the CRa group, whereas OA induce only an early asthmatic response (3/6) in the OA group (P<0.01). The average total leukocytes in BALF of the CRa were 27.0x10(6), mostly neutrophils and eosinophils, while those of the OA showed 3.5x10(6), mostly eosinophils, respectively (P<0.0001). TSM responses to non-specific stimuli were similar in both groups (P>0.1), while the antigen-specific TSM contractions were more brisk in the OA group than those of CRa group (P<0.001). Thus, the study indicates that both CRa and OA sensitize guinea-pigs, yet CRa induces more severe and persistent late-phase inflammation than OA. This appears to be related to an influx of neutrophils rather than anaphylactic bronchospasm.

US and CT findings of tuberculosis of the thyroid: three case reports

With two ultrasonographic and two CT films of three cases of thyroid tuberculosis, we evaluate the ultrasonographic and CT findings and correlate them with the pathologic findings. They are demonstrated as heterogeneous hypoechoic mass on ultrasonogram and peripheral-enhancing low-density abscess on CT scan with regional lymphadenopathy. Ultrasonography (US) and CT can help the diagnosis of thyroid tuberculosis.

Preventive effect of epicatechin and ginsenoside Rb(2) on the inhibition of gap junctional intercellular communication by TPA and H(2)O(2)

The anticarcinogenic effects of epicatechin (EC) and ginsenoside Rb(2) (Rb(2)), which are major components of green tea and Korea ginseng, respectively, were investigated using a model system of gap junctional intercellular communication (GJIC) in WB-F344 rat liver epithelial cells. 12-O-tetradecanoylphorbol-13-acetate (TPA) and hydrogen peroxide, known as cancer promoters, inhibited GJIC in the epithelial cells as determined by the scrape loading/dye transfer assay, fluorescence redistribution assay after photobleaching, and immunofluorescent staining of connexin 43 using a laser confocal microscope. The inhibition of GJIC by TPA and H(2)O(2) was prevented with treatment of Rb(2) or EC. The effect of EC on GJIC was stronger in TPA-treated cells than in H(2)O(2)-treated cells, while the effect of Rb(2) was opposite to that of EC. EC, at the concentration of 27.8 microg/ml, prevented the TPA-induced GJIC inhibition by about 60%. Rb(2,) at the concentration of 277 microg/ml, recovered the H(2)O(2)-induced GJIC inhibition by about 60%. These results suggest that Rb(2) and EC may prevent human cancers by preventing the down-regulation of GJIC during the cancer promotion phase and that the anticancer effect of green tea and Korea ginseng may come from the major respective components, EC and Rb(2).

Pancreatic serous cystadenoma associated with islet cell tumour

We report the case of a 29-year-old female patient with a diffuse type of serous cystadenoma involving the entire pancreas except for part of the head, which was replaced by islet cell tumour. Ultrasound and CT showed multiple cysts in the entire pancreas and a solid mass with calcification in the head. MRI characterized the fluid content of the cysts and the extent of disease.

Value of the dynamic and delayed MR sequence with Gd-DTPA in the T-staging of stomach cancer: correlation with the histopathology

BACKGROUND

To evaluate the usefulness of dynamic and delayed magnetic resonance (MR) imaging in the T-staging of stomach cancer and to compare the enhancement pattern of the cancerous lesion and the normal wall.

METHODS

We performed MR imaging in 46 patients with stomach cancer (including four early gastric cancers and 42 advanced gastric cancers). Axial, sagittal, or coronal two-dimensional fast low-angle shot) MR images for the water-distended stomach were obtained with dynamic protocol, including precontrast images and images obtained 30, 60, 90, and 240-300 s after intravenous injection of the 0.1 mM Gd-DTPA/kg solution. We evaluated the thickness, interruption (or not) of the low signal intensity bands, and enhancement pattern of the cancerous wall and normal gastric wall. We prospectively evaluated the depth of cancer invasion, perigastric infiltration (extraserosal invasion), perigastric organ invasion, and regional lymph nodes and determined tumor staging on MR images. These MR evaluations including MR-determined staging were correlated with the surgicopathologic findings.

RESULTS

Stomach cancer was shown as having a thickened wall with a rapid enhancing pattern after intravenous Gd-DTPA administration. The mucosa (and/or submucosa) affected by stomach cancer showed an early enhancement pattern (30-90 s after Gd-DTPA administration) in 43 of 46 patients (93%). The normal gastric mucosa demonstrated a delayed peak enhancement pattern (> 90 s after Gd-DTPA administration) in 29 of 46 patients (63%) and variable enhancement pattern in 17 of 46 patients (37%). An interrupted low signal intensity band or highly enhanced tumorous lesion penetrating through the gastric wall was seen in 17 of 19 pT3 patients (90%). Consistency between MR-determined staging and surgicopathologic staging occurred in three of four pT1 tumors (75%), 10 of 13 pT2 tumors (77%), 17 of 19 pT3 tumors (90%), and eight of 10 pT4 tumors (80%); overall accuracy was 83%. Overall accuracy of regional lymph node involvement, as determined by enhanced MR, was 52%; 24 of 46 node groups were positive.

CONCLUSIONS

Dynamic and delayed MR imaging can be useful for predicting depth of cancer invasion, perigastric infiltration (extraserosal invasion), and perigastric organ invasion by gastric cancer.