The Usefulness of Rectified VEMP

OBJECTIVES: For a reliable interpretation of left-right difference in Vestibular evoked myogenic potential (VEMP), the amount of sternocleidomastoid muscle (SCM) contraction has to be considered. Therefore, we can ensure that a difference in amplitude between the right and left VEMPs on a patient is due to vestibular abnormality, not due to individual differences of tonic muscle activity, fatigue or improper position. We used rectification to normalize electromyograph (EMG) based on pre-stimulus EMG activity. This study was designed to evaluate and compare the effect of rectification in two conventional ways of SCM contraction. METHODS: Twenty-two normal subjects were included. Two methods were employed for SCM contraction in a subject. First, subjects were made to lie flat on their back, lifting the head off the table and turning to the opposite side. Secondly, subjects push with their jaw against the hand-held inflated cuff to generate cuff pressure of 40 mmHg. From the VEMP graphs, amplitude parameters and inter-aural difference ratio (IADR) were analyzed before and after EMG rectification. RESULTS: Before the rectification, the average IADR of the first method was not statistically different from that of the second method. The average IADRs from each method decreased in a rectified response, showing significant reduction in asymmetry ratio. The lowest average IADR could be obtained with the combination of both the first method and rectification. CONCLUSION: Rectified data show more reliable IADR and may help diagnose some vestibular disorders according to amplitude-associated parameters. The usage of rectification can be maximized with the proper SCM contraction method.

Treatment Result of Mastoidectomy in Pediatric Chronic Suppurative Otitis Media / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Chronic suppurative otitis media (CSOM) is a common infectious disease in childhood of poor hygiene group. In addition, in industrialized countries, with rising popularity of tympanostomy tubes for management of otitis media with effusion, CSOM is a potential problem in any child who had inserted ventilating tubes previously. Hearing loss following CSOM can negatively affect learning, speech, and cognitive function, so effective and timely management of CSOM is mandatory. The surgical procedure may be necessary in some children with CSOM, but when it is performed at a too early age, there might be more chances of recurrence than adults. SUBJECTS AND METHOD: Used in the study were 51 ears from patients who received tympanomastoidectomy due to CSOM in tertiary referral center from 1995 through 2004. The mean age was 9 years and 6 months. Cholesteatoma was found in 30 cases (58.8%). Age at operation, hearing outcomes, and the surgical results were retrospectively reviewed. RESULTS: Canal wall down mastoidectomy was performed in 23 cases and canal wall up procedure in 28 cases. Revision surgery was performed in 9 cases (17.6%) and mean duration between first and revision surgery was 27 months. In the cases of cholesteatoma, the rate of revision surgery was different between under 6 years old and over 7 years old group (p=.045). The age at 1st operation and postoperative hearing outcome had no correlation. CONCLUSION: Since the1st operation is performed earlier, the rate of revision may increase, especially in cases of cholesteatoma.

Effect Assessment of Worksite-based, Post-examination, Health Care Management System / 대한산업의학회지

OBJECTIVES: This study was conducted to develop a worksite-based, post-examination, health care management system for continuous and systematic management of workers with hypertension, diabetes mellitus, hyperlipidemia, and abnormal LFT detected by periodic health examination and to assess the effectiveness such a system as an intervention study. METHODS: Study subjects were selected from workers with hypertension, diabetes mellitus, hyperlipidemia, and abnormal LFT according to the selection criteria. The intervention group, but not the control group, received medical treatment of disease, follow up examination, and health education which consisted of information about the disease and the importance of life-style modification through periodic interview using the resources of occupational health service center in the worksite. To assess the effectiveness of this system, we compared follow up examination data from the intervention group with periodic examination data from the worksite control group. RESULTS: In the intervention group a significant reduction trend was recorded for systolic and diastolic blood pressure, fasting blood sugar, postprandial 2 hour glucose, total cholesterol, triglyceride, LDL-cholesterol, AST, ALT, and gamma-GTP, and a rising trend for HDL-cholesterol. Significant group differences ware recorded for fasting blood sugar, postprandial 2 hour glucose, total cholesterol, AST, and ALT. CONCLUSIONS: The worksite-based, post-examination, health care management system was effective for the continuous and systematic management of workers who had abnormal findings detected by periodic health examination.

The Association between Pneumoconiosis and Genetic Polymorphism of GSTM1, GSTT1, GSTP1, NAT2, CYP2E1 and CYP1A1 / 대한산업의학회지

OBJECTIVES: To investigate effects of genetic polymorphism of glutathione S-transferase M1 (GSTM1), glutathione S-transferase T1 (GSTT1), glutathione S-transferase P1 (GSTP1), N-acetyltransferase (NAT2), cytochrome P450 2E1 (CYP2E1) and cytochrome P450 1A1 (CYP1A1) on pneumoconiosis. METHODS: Eighty-five pneumoconiosis patients and 122 age and sex matched healthy controls were enrolled. Direct interview and standard questionnaire were conducted and the genotypes of GSTM1, GSTT1, GSTP1, NAT2, CYP2E1 and CYP1A1 were investigated using multiplex PCR or PCR-RFLP methods with DNA extracted from venous blood. The relationship was investigated between the severity of pneumoconiosis and the polymorphism of GSTM1, GSTT1, GSTP1, NAT2, CYP2E1 and CYP1A1, and also with various environmental factors including smoking. RESULTS: We observed a significantly higher rate of genetic polymorphism in pneumoconiosis patients than in normal subjects. The odds ratio (95% CI) of NAT2 was 2.09 (1.19-3.68). In addition, smoking was related significantly with pneumoconiosis (OR 2.89, 95% CI 1.40-5.95). In multiple logistic regression analyses, NAT2 and smoking were significant risk factors for the development of pneumoconiosis (OR 1.84, 95% CI 1.00-3.37; OR 2.98, 95% CI 1.40-6.35, respectively). The age of onset of the disease and smoking were significantly related with moderate or severe pneumoconiosis (OR 0.91, 95% CI 0.83-0.99; OR 6.94, 95% CI 1.54-31.30, respectively). However there was no significant difference between the rate of genetic polymorphism of GSTM1, GSTT1, GSTP1, CYP2E1 and CYP1A1 in the two groups. CONCLUSION: NAT2 genetic polymorphism was higher in pneumoconiosis patients than in normal subjects. The age of onset of the disease and smoking were significantly related with pneumoconiosis. However, the genetic polymorphism of GSTM1, GSTT1, GSTP1, CYP2E1 and CYP1A1 was not related with development or severity of pneumoconiosis.

Exfoliative Dermatitis and Toxic Hepatitis Associated with Occupational Exposure to Trichloroethylene / 대한산업의학회지

A 28-year-old male began working as a degreaser. The solvent used in the degreasing operation was trichloroethylene. Over the next month the man experienced fever, chills, and an erythematous skin rash and itching. At that time he had a marked elevation in his liver enzyme, with cholestasis. Over the next few days the rash persisted then peeled. There was an elevation of Ig E, and a positive patch test reaction to trichloroethylene. His dermatitis and hepatitis were considered to be mediated by a hypersensitivity mechanism.

Intraductal Papilloma Arising in the Sublingual Salivary Gland / 대한이비인후과학회지

Intraductal papilloma that arises from the salivary gland is an extremely rare benign tumor and mostly affects the minor salivary gland. We have experienced a case of an intraductal papilloma arising from the sublingual salivary gland in a 51-year-old woman. The radiologic finding shows an unicystic mass having solid portion. The tumor was completely excised transorally. The histologic findings are papillary proliferation of two uniform layers of columnar epithelial and flat basal cells supported by a fibrovascular core. The clinicopathologic features of this tumor is presented with a review of literature.

Volume Measurement of Vestibular Schwannoma Using New Software / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Vestibular schwannomas are intracranial neoplasms that compress adjacent structures as their volume grows. Although the clinically relevant parameter is most likely tumor volume, current clinical decisions are based on two-dimensional measurements of tumor diameter. This study was conducted to introduce a new software for accurate measurement of vestibular schwannoma volume and to determine the relationship between diameter and volume. Material and Method: Twenty-eight patients who had no previous treatment before MRI were included in this study. Diameter of the vestibular schwannoma was measured according to AAO guidelines and spherical volume was calculated from the diameter. For the accurate volume measurement of the vestibular schwannoma, we used a new software (Rapidia, 3D Med Co) developed in Korea. Paired t-test was used for the statistical analysis of correlation between the measured and calculated volumes. RESULTS: The difference between the measured and calculated volumes was statistically not significant (p=.120). However, as tumor size increased greater than 2 cm in diameter, our measured volume result was smaller than the calculated volume, although statistically not significant (p=.067). CONCLUSION: These results were due to tumor configuration, which was wider in the axial plane than in the longitudinal plane. From these results, we can realize that initial tumor growth was spherical, and as the size increased, it was distorted by the adjacent structures. These results suggest that special attention is needed in making clinical decisions on larger tumors, especially greater than 2 cm in diameter.

Sclerotherapy for Craniofacial Venous Malformation / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Venous malformations are one of the most common vascular anomalies, and are more frequently found in head and neck region. Various treatment options are available, and intralesional injection of sclerosant is the commonest primary treatment modality. We reviewed 20 cases of venous malformation treated with sclerotherapy at Seoul National University Hospital. MATERIALS AND METHODS: Twenty cases of venous malformation in head and neck were reviewed retrospectively, which had been managed with sclerotherapy from January 1991 to July 2001. The patients were treated at the department of otolaryngology-Head and Neck Surgery or plastic surgery of Seoul National University Hospital. Emulsion of Ethamolin and Lipiodol was used as a sclerosing agent. Some patients received surgical treatment after sclerotherapy. All of the patients received direct-puncture venography(Digital subtraction angiography) before sclerotherapy. Treatment results were evaluated by using MRI, angiography, or CT. If the reduction of volume of mass was more than 50 percent after sclerotherapy, we regarded the result as effective, if less than 50 percents, non-effective. Statistical analysis was done using SPSS10.0 for windows. RESULTS: Among twenty patients, there were eight males(40%), and twelve females(60%). Ages at the beginning of treatment ranged from six to thirty-eight years(mean age:20.6 years). The most common site of lesions was cheek(in 12 cases). Mass sizes(largest diameter) ranged from 2 cm to 20 cm. Nine cases were managed with both sclerotherapy and surgical excision, and eleven cases, only with sclerotherapy. Thirteen cases(65%) responded well to sclerotherapy(volume reduction>or=50%). There was no major complication. Tenderness, induration, swelling, and pain were reported as post-sclerotherapy complaints. Mild dyspnea occurred in one case, and the patient was managed at ICU shortly without fatal event. CONCLUSION: Sclerotherapy with or without surgical excision was an effective treatment modality for venous malformation, with minimal risk of major complications. There were no significant differences in the treatment results according to the initial size of the lesions.

Management of Pyriform Sinus Fistula with Chemocauterization / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: A pyriform sinus fistula can cause a recurrent abscess in the neck. Complete excision is recommended but in many cases, surgery is complicated because of recurrent infection. Recurrence may result from failure to recognize, or inadequate excision of the tract. To avoid this, we attempted chemocauterization of the internal opening of the fistula tract with trichloracetic acid (TCA) on suspension laryngoscopy. MATERIALS AND METHOD: This was a 9-year review of 30 patients with pyriform sinus fistula. Medical history, diagnostic methods, operative findings and treatment results were analyzed with a review of the literatures. RESULTS: On suspension laryngoscopy, a fistula opening was found in the pyriform sinus of all patients, mainly on the left side. Except for two patients, 28 patients were managed by TCA chemocauterization. Of the five patients who had recurrent masses, three patients were successfully managed by simple excision and two patients were managed by repeated TCA cauterization with unobliterated internal openings. There was no serious intra- or postoperative complication. CONCLUSION: TCA cauterization is an appropriate first line treatment method for pyriform sinus fistula, especially for patients who have had recurrent neck abscess and undergone open drainage procedure. This method can be used to avoid morbidity of an open surgical procedure.

Characteristics of Work-Related Musculoskeletal Disorders and Effect of Intervention Program in Shipyard Workers / 대한산업의학회지

OBJECTIVES: This study was conducted to estimate the characteristics of work-related musculoskeletal disorders and the effect of intervention program in shipyard workers. METHODS: Information on work related absences,due to musculoskeletal disorders, were collected between January, 1 2000 and August, 31 2002. Age, duration of work, job type, anatomical site of disease, cause and duration of absence due to sickness were investigated. RESULTS: From a total of 158 cases there were 108(68.4%)and 50(31.6%)cases of back, and other musculoskeletal complaints,respectively. 55(34.8%)of the cases were caused by repetitive trauma and 103(65.2%)were due to non-repetitive causes. 90(83.3%)of the back complaint cases were due to non-repetitive causes, but there was a repetitive cause of other musculoskeletal complaints in 37(74.0%)cases. Back complaints were higher in workers carrying heavy materials, but other musculoskeletal complaints were higher in painting workers.Half of workers after an absence due to sickness had returned to work within 32.0 weeks and 25.4 weeks,in the cases of back and other musculoskeletal complaints, respectively. After the application of an intervention program for musculoskeletal disease, the incidence rate of absence due to work-related musculoskeletal disorders was reduced significantly. CONCLUSION: The introduction of a musculoskeletal intervention program reduced absences due to work-related musculoskeletal disorders.

Traumatic Hypopharyngeal-Cervical Esophageal Injuries / 대한이비인후과학회지

BACKGROUND AND OBJECTIVES: Traumatic perforation in hypopharynx and cervical esophagus may be fatal, causing mediastinitis or sepsis. We present six cases of clinical experiences to outline diagnosis and management. MATERIALS AND METHOD: We retrospectively reviewed six patients with hypopharyngeal-cervical esophageal injury, over the period of recent two years. We summarized the method of diagnosis, treatment and clinical course with review of the literature. RESULTS: There were two cases of external blunt trauma, two cases of iatrogenic causes, and two cases of intraluminal injuries. The common clinical signs were painful neck swelling and fever. The five of six in routine X-ray showed air shadow in the neck or chest. The neck CT showed air or abscess in all six cases. The surgical drainage was performed in four cases. CONCLUSION: The diagnostic methods of hypopharyngeal-cervical esophageal injuries include chest X-ray, neck X-ray, Gastrografin(r) esophagography and CT after thorough history-taking and physical examination. CT was highly sensitive and important for decision of surgical management. Surgery is recommended if there is large perforation, abscess, mediastinal contamination or sepsis. In selective cases, non-surgical management is possible.

A Study on The Change of HBsAg and Anti-HBs Positivities for A Recent 15 Year Period in Korea / 대한간학회지

BACKGROUND/AIMS: The HBsAg positivity in the normal Korean population has been reported as 2-10%. It has been decreasing since hepatitis B vaccine was introduced to routine vaccination regimens in 1992. Reports on the changes of anti-HBs over the years are hard to find since the discrepancies in sensitivities of test methods used by different researchers did not allow equivalent comparisons. The purpose of this study was to evaluate the changes of HBsAg and anti-HBs posivities for a recent 15 year period. METHODS: From 1998 to 2000, 4771 subjects in Chonnam province were included in this study. Serum HBsAg and anti-HBs were detected by reversed passive hemagglutination (RPHA) and passive hemagglutination (PHA) respectively. The changes in the HBsAg and anti-HBs positivity by the same test methods for the period were analyzed by comparing our results with those of 12 other previous reports. RESULTS: The positivities of HBsAg and anti-HBs were 5.3% and 47.5%. The positivity of HBsAg was significantly higher in males, while that of anti-HBs was significantly lower in males (p40) was significantly higher statistically (p<0.01). The positivity of HBsAg decreased with years (r=-0.845, p<0.01), while that of anti-HBs increased with years (r=0.616, p<0.05). CONCLUSION: The positivity of HBsAg has significantly decreased and that of anti-HBs has increased with years for the period under study.

Survey on the Prevalence of Carpal Tunnel Syndrome in Simple Repetitive Workers Who Use Upper Extremities / 대한산업의학회지

OBJECTIVES: This study was carried out to survey on the prevalence of Carpal Tunnel Syndrome(CTS) in high risk jobs(meat and fish processing plant and wood plant), by application of Nerve Conduction Study(NCS), a confirmatory diagnostic method. METHODS: Experimental group was 69 workers sampled from meat and fish processing plants and 17 workers sampled from wood plants, who were simple, repetitive workers using upper extremities and control group was 28 workers sampled from managers, secretaries and keepers. All employees were examined through work history, physical examination and NCS. RESULTS: 18 workers(26.09%) in meat and fish processing plants, and 5 workers(29.41%) in wood plants had compatible findings to NIOSH diagnostic criteria for CTS. The experimental group had more symptoms(complaint of upper extremities, Visual Analogue Scale >or= 4(VAS: total 10 point)), signs(Tinel and Phalen test) and prevalence of CTS than control group ( por=7 years). CONCLUSIONS: The prevalence of CTS in meat and fish processing plant and wood plant were 26.09% and 29.41% respectively. Authors propose that meat and fish processing and wood plants should be managed as a risk job category which were designated by OSHA in 1996

Low Back Pain Assessment Using Surface Electromyography and Digital Infrared Thermographic Imaging / 대한산업의학회지

OBJECTIVES: We studied the efficacy of surface electromyography(SEMG) and digital infrared thermographic imaging(DITI) in the assessment of low back pain both(LBP) quantitatively and qualitatively. METHODS: We compared electromygraphic signals from electrodes placed in the lumbar area and the digital thermographic images in 16 LBP patients and 16 control subjects. The LBP patients and the control subjects were matched for age, gender, and body mass index(BMI) to adjust for any confounding effects RESULTS: In the static analyses of SEMG, median value was 198.1 microV for the LBP patients and 161.3 microV for the controls on the right side, and they were 194.2 microV and 180.5 microV on left side respectively. There was a statistically significant difference between the two groups on the right side(p<0.01), but not on the left side. In the dynamic analyses of the SEMG, the median values of the extension per flexion ratio of right side were 1.12 for LBP patients and 1.39 for controls. and those on the left side were 1.08 and 1.21 respectively. There were statistically significant differences in both sides(p<0.05). The sensitivity and specificity were 100% and 81.3% in DITI, 78.6% and 72.2% in SEMG . CONCLUSIONS: These results indicate that SEMG and DITI are useful methods for indirect assessments of LBP, and that DITI is more sensitive and specific than SEMG.

Airway hyperresponsiveness among workers exposed to isocyanates at Yeocheon petrochemical plant / 천식및알레르기

OBJECTIVE: To investigate the prevalence of airway hyperresponsiveness induced by isocyanate at one petrochemical industry complex in Yeochon, Korea. METHOD: Questionnaires, allergic skin prick test, toluene diisocyanate (TDI)-specific IgE, and non-specific airway hyperresponsiveness (AHR) were studied in 73 exposed workers and 27 control subjects. Methacholine challenge tests were done and bronc hial responsiveness (BR index) was defined as log (% fall of FEV1)/ log (last concentration of methacholine +10). RESULTS: Twenty-three workers (31.5% ) had respiratory symptoms, 21 had nasal symptoms, and eight had skin symptoms. Exposed workers with respiratory symptoms (n=22) had significantly higher BR index than those without them (0.82+/-0.06 vs 0.60+/-0.02, p0.05). Specific IgE antibodies were found in 19.7% of exposed workers. FEV, showed a significant negative correlation with BR index (r =-0.25, p<0.05). Poor correlation was noted between BR index and atopy, smoking status, or exposure duration. CONCLUSION: These findings suggest that workers exposed to isocyanates are at higher risk of airway hyperresponsiveness.

Evaluation of cytotoxicity and bone affinity on the surface of a titanium phosphide / 대한치주과학회지

Dental implants have been developed for enhancement of osseointegration. Biocompatibility, bone affinity and surface characteristics of dental implants are very important factors for osseointegration. The aim of the present study was to determine the cytotoxicity and the bone affinity of titanium phosphide(Ti-P) implant material. The Ti-P surface was obtained by vacuum sintering of titanium within compacted hydroxyapatite powder. The composition and the chemical change of the surface were determined by Auger electron spectroscopy. The in vitro cytotoxicity was evaluated by the viability of the bone cells and macrophages obtained from chicken embryo and rat,s peritonium, respectively. For the comparative evaluation, 316L stainless steel, commercially pure titanium and Ti-P materials, prepared in size of 10.0mm in diameter and 5.0mm in height, were immersed separately in bone cells and macrophages for 10 days. For the evaluation of the in vivo bone affinity, 316L stainless steel, commercially pure titanium and Ti-P materials, prepared in size of 5.0mm in diameter and 10.0mm in length, were implanted after drilling in diameter 5.5mm in femurs of 2 dogs weighing 10Kg more or less. Six weeks after implantation the specimens were prepared for histopathological examination and were observed under light microscope. In comparison of in vitro bone cell viability, Ti-P and commercially pure titanium groups were not significantly different from control group(p>0.1), but 316L stainless steel group was significantly lower than control group(p0.1). In comparison of in vivo study, 316L stainless steel and commercially pure titanium showed fibrous encapsulation, but Ti-P showed remarkable new bone formation without any fibrous tissue. The results demonstrate that Ti-P has favorable biocompatibility and bone affinity, and suggest that dental implants with Ti-P surface may enhance osseointegration.