ABSTRACT
Innate lymphoid cells (ILCs) are key players during an immune response at the mucosal surfaces, such as lung, skin, and gastrointestinal tract. Giardia lamblia is an extracellular protozoan pathogen that inhabits the human small intestine. In this study, ILCs prepared from the lamina propria of mouse small intestine were incubated with G. lamblia trophozoites. Transcriptional changes in G. lamblia-exposed ILCs resulted in identification of activation of several immune pathways. Secretion of interleukin (IL)-17A, IL-17F, IL-1β, and interferon-γ was increased, whereas levels of IL-13, IL-5, and IL-22, was maintained or reduced upon exposure to G. lamblia. Goup 3 ILC (ILC3) was found to be dominant amongst the ILCs, and increased significantly upon co-cultivation with G. lamblia trophozoites. Oral inoculation of G. lamblia trophozoites into mice resulted in their presence in the small intestine, of which, the highest number of parasites was detected at the 5 days-post infection. Increased ILC3 was observed amongst the ILC population at the 5 days-post infection. These findings indicate that ILC3 from the lamina propria secretes IL-17 in response to G. lamblia, leading to the intestinal pathology observed in giardiasis.
Subject(s)
Animals , Humans , Mice , Gastrointestinal Tract , Giardia lamblia , Giardia , Giardiasis , Interleukin-13 , Interleukin-17 , Interleukin-5 , Interleukins , Intestine, Small , Lung , Lymphocytes , Mucous Membrane , Parasites , Pathology , Skin , TrophozoitesABSTRACT
PURPOSE: To evaluate the therapeutic effect of human embryonic stem cell (hESC)-derived multipotent mesenchymal stem cells (M-MSCs) on ketamine-induced cystitis (KC) in rats. METHODS: To induce KC, 10-week-old female rats were injected with 25-mg/kg ketamine hydrochloride twice weekly for 12 weeks. In the sham group, phosphate buffered saline (PBS) was injected instead of ketamine. One week after the final injection of ketamine, the indicated doses (0.25, 0.5, and 1×106 cells) of M-MSCs (KC+M-MSC group) or PBS vehicle (KC group) were directly injected into the bladder wall. One week after M-MSC injection, the therapeutic outcomes were evaluated via cystometry, histological analyses, and measurement of gene expression. Next, we compared the efficacy of M-MSCs at a low dose (1×105 cells) to that of an identical dose of adult bone marrow (BM)-derived MSCs. RESULTS: Rats in the KC group exhibited increased voiding frequency and reduced bladder capacity compared to rats of the sham group. However, these parameters recovered after transplantation of M-MSCs at all doses tested. KC bladders exhibited markedly increased mast cell infiltration, apoptosis, and tissue fibrosis. Administration of M-MSCs significantly reversed these characteristic histological alterations. Gene expression analyses indicated that several genes associated with tissue fibrosis were markedly upregulated in KC bladders. However the expression of these genes was significantly suppressed by the administration of M-MSCs. Importantly, M-MSCs ameliorated bladder deterioration in KC rats after injection of a low dose (1×105) of cells, at which point BM-derived MSCs did not substantially improve bladder function. CONCLUSIONS: This study demonstrates for the first time the therapeutic efficacy of hESC-derived M-MSCs on KC in rats. M-MSCs restored bladder function more effectively than did BM-derived MSCs, protecting against abnormal changes including mast cell infiltration, apoptosis and fibrotic damage.
Subject(s)
Adult , Animals , Female , Humans , Rats , Apoptosis , Bone Marrow , Cystitis , Fibrosis , Gene Expression , Human Embryonic Stem Cells , Ketamine , Mast Cells , Mesenchymal Stem Cells , Multipotent Stem Cells , Pelvic Pain , Urinary BladderABSTRACT
What is the most important area to focus on to improve health in Korea? The overall number of doctors is the only indicator of the health care system that is currently emphasized by the government. Instead, we should focus on the number of public hospital beds, which is very low, and health expenditures, which are below average when normalized for gross domestic product. In most Organization for Economic Cooperation and Development countries, the public sector is the main source of health care financing, with approximately three-quarters of health care spending originating from the public sector. In Korea, social health insurance and the government currently finance approximately 55% of all health expenditures. In contrast, Korea has a top ranking in comparison to other countries with regard to the number of private hospital beds. The ratio of medical doctors, dentists, and Korean traditional doctors in the workforce in primary clinics is approximately 2.5:1.3:1. Therefore, the Korean government should decide whether traditional doctors should be included in the health care delivery system. Most medical doctors in primary clinics are specialists who require a corresponding support system. The training of new doctors is too fast, as the overall number of doctors in Korea is sufficient. The government should develop the best possible plan to help doctors be doctors and show their devotion to the community.
Subject(s)
Humans , Delivery of Health Care , Dentists , Gross Domestic Product , Health Expenditures , Hospitals, Private , Hospitals, Public , Insurance, Health , Korea , Organisation for Economic Co-Operation and Development , Public Sector , SpecializationABSTRACT
Trichomonas vaginalis is a pathogen that triggers severe immune responses in hosts. T. vaginalis α-actinin 2, Tvα-actinin 2, has been used to diagnose trichomoniasis. This study was undertaken to examine the role of Tvα-actinin 2 as an antigenic molecule to induce immune responses from humans. Western blot analysis using anti-Tvα-actinin 2 antibodies indicated its presence in the secreted proteins of T. vaginalis. ELISA was employed to measure cytokine production by vaginal epithelial cells, prostate cells, mouse dendritic cells (DCs), or T cells stimulated with T. vaginalis or Tvα-actinin 2 protein. Both T. vaginalis and rTvα-actinin 2 induced cytokine production from epithelial cell lines, including IL-10. Moreover, CD4+CD25− regulatory T cells (Treg cells) incubated with rTvα-actinin 2-treated DCs produced high levels of IL-10. These data indicate that Tvα-actinin 2 modulates immune responses via IL-10 production by Treg cells.
Subject(s)
Animals , Humans , Mice , Antibodies , Blotting, Western , Dendritic Cells , Enzyme-Linked Immunosorbent Assay , Epithelial Cells , Interleukin-10 , Prostate , T-Lymphocytes , T-Lymphocytes, Regulatory , Trichomonas vaginalis , TrichomonasABSTRACT
OBJECTIVES: This study was performed to develop a food safety education program for school foodservice employees and evaluate its effectiveness. METHODS: Food safety education programs were made into two levels; one for new employees in school foodservice and another for employees in charge of Critical Control Point (CCP) monitoring. The programs were for 40-minute-long lecture using PowerPoint. The effectiveness of these programs were assessed based on eleven evaluation items by school foodservice dieticians (n=30) and the Hazard Analysis Critical Control Point (HACCP) specialist (n=13). All statistical analyses are conducted by SPSS package program (ver 20.0). RESULTS: According to the results of evaluating the food safety education program by dietitian and HACCP specialist, the overall satisfaction score was 4.14, evaluated by 5 point scale. There were no significant difference in results of evaluation between dieticians and HACCP specialists. The score of 'it is helpful to work' and 'pictures, images and charts are pertinent to study' were higher than others while the score of 'education contents is pleasant and interesting' and 'screen is pleasant and interesting' were the lowest among all evaluation items. CONCLUSIONS: To increase the school foodservice quality, employees should be offered regular food safety education and training through effective education media including prerequisite program and HACCP manual for school foodservice.
Subject(s)
Humans , Education , Food Safety , Hazard Analysis and Critical Control Points , Nutritionists , SpecializationABSTRACT
PURPOSE: Due to the increasing numbers of radical prostatectomies (RP) performed for prostate cancer, a substantial and increasing number of patients suffer from postoperative urinary incontinence and erectile dysfunction (ED). The objective of our study was to see whether an inflatable penile prosthesis implantation could control urinary incontinence for patients with the dual problems of ED and incontinence. MATERIALS AND METHODS: From March 2010 through May 2015, 25 post-RP patients were referred to our clinic with ED or incontinence. The degree of incontinence was classified according to the International Consultation on Incontinence Questionnaire-Short Form. Inflatable penile prostheses were implanted in all 25 patients. RESULTS: For one month after implantation, partial or full inflation was performed progressively to control urine leakage. Of 18 patients, 13 patients were categorized with mild or moderate stress incontinence. All 13 patients obtained control of incontinence with partial inflation (30% to 60%) and all reported satisfactory outcomes. Five out of the 18 patients were categorized with severe total incontinence. Three of the 5 patients could tolerate incontinence with full inflation on and off. Thirteen patients out of the total of 18 (72.2%) had their incontinence controlled by an inflating penile prosthesis. CONCLUSIONS: An inflatable penile prosthesis is highly recommended as an initial procedure, especially in patients with the dual problems of ED and incontinence.
Subject(s)
Humans , Male , Erectile Dysfunction , Inflation, Economic , Penile Implantation , Penile Prosthesis , Prostatectomy , Prostatic Neoplasms , Urinary IncontinenceABSTRACT
Bilateral paramedian thalamic infarction is a rare subtype of stroke caused by occlusion of the artery of Percheron, an uncommon variant originating from one of the posterior cerebral arteries. This type of stroke has several major clinical presentations: altered mental status, behavioral amnestic impairment, aphasia or dysarthria, ocular movement disorders, motor deficits, cerebellar signs, and others. Few cases of bilateral paramedian thalamic infarction-related pseudobulbar palsy characterized by dysarthria, dysphagia, and facial and tongue weakness have been reported. We report here a rare case of acute severe pseudobulbar palsy as a manifestation of bilateral paramedian thalamic infarction.
Subject(s)
Aphasia , Arteries , Deglutition Disorders , Dysarthria , Infarction , Movement Disorders , Posterior Cerebral Artery , Pseudobulbar Palsy , Stroke , Thalamus , TongueABSTRACT
Gastric volvulus is an uncommon clinical entity. There are three types of gastric volvulus; organoaxial, mesenteroaxial and combined type. This condition can lead to a closed-loop obstruction or strangulation. Traditional surgical therapy for gastric volvulus is based on an open approach. Here we report a successful case of a patient with chronic gastric volvulus with a laparoscopic treatment. A 79-year-old woman came to the emergency department with epigastric pain accompanied by nausea for 2 weeks. Abdominal computed tomography revealed markedly distended stomach with transposition of gastroesophageal Junction and gastric antrum. Barium meal study revealed presence of the antrum was folded over 180 degrees that was located above gastroesophageal junction. We attempted an endoscopic reduction, but it was unsuccessful. The patient got laparoscopic anterior gastropexy. Based on our result, laparoscopic gastropexy can be considered as a good choice of the treatment for gastric volvulus.
Subject(s)
Aged , Female , Humans , Barium , Emergency Service, Hospital , Endoscopy , Esophagogastric Junction , Gastropexy , Laparoscopy , Meals , Nausea , Pyloric Antrum , Stomach , Stomach VolvulusABSTRACT
A 50-year-old man with liver cirrhosis and esophageal varix for 3 years was diagnosed with hematemesis and treated for a bleeding varix. However, bleeding recurred 11 days later, and he developed drowsiness with left hemiparesis. His left upper and lower extremity muscle strengths based on the manual muscle test at the onset were grade 2/5 and 1/5, respectively. The Babinski sign was positive. His serum ammonia level was elevated to 129.9 microg/dL (normal, 20-80 microg/dL). Magnetic resonance imaging revealed restriction on diffusion and T2-hyperintensities with decreased apparent diffusion coefficient values in the bilateral frontoparietooccipital cortex. The effect was more severe in the right hemisphere and right parietooccipital cortices, which were compatible with hepatic encephalopathy. Although the patient's mental status recovered, significant left-sided weakness and sensory deficit persisted even after 6 months. Diffusion tensor tractography (DTT) performed 3 months post-onset showed decreased volume of the right corticospinal tract. We reported a patient with hepatic encephalopathy involving the corticospinal tract by DTT.
Subject(s)
Humans , Middle Aged , Ammonia , Diffusion Tensor Imaging , Diffusion , Esophageal and Gastric Varices , Hematemesis , Hemorrhage , Hepatic Encephalopathy , Liver Cirrhosis , Lower Extremity , Magnetic Resonance Imaging , Muscle Strength , Paresis , Pyramidal Tracts , Reflex, Babinski , Rehabilitation , Sleep Stages , Varicose VeinsABSTRACT
OBJECTIVE: To evaluate the usefulness of various magnetic resonance imaging (MRI) findings in the prognosis of neurological recovery in paraplegics with thoracolumbar fracture using association analysis with clinical outcomes and electrodiagnostic features. METHODS: This retrospective study involved 30 patients treated for paraplegia following thoracolumbar fracture. On axial and sagittal T2-weighted MRI scans, nerve root sedimentation sign, root aggregation sign, and signal intensity changes in the conus medullaris were independently assessed by two raters. A positive sedimentation sign was defined as the absence of nerve root sedimentation. The root aggregation sign was defined as the presence of root aggregation in at least one axial MRI scan. Clinical outcomes including the American Spinal Injury Association impairment scale, ambulatory capacity, and electrodiagnostic features were used for association analysis. RESULTS: Inter-rater reliability of the nerve root sedimentation sign and the root aggregation sign were kappa=0.67 (p=0.001) and kappa=0.78 (p<0.001), respectively. A positive sedimentation sign was significantly associated with recovery of ambulatory capacity after a rehabilitation program (chi2=4.854, p=0.028). The presence of the root aggregation sign was associated with reduced compound muscle action potential amplitude of common peroneal and tibial nerves in nerve conduction studies (chi2=5.026, p=0.025). CONCLUSION: A positive sedimentation sign was significantly associated with recovery of ambulatory capacity and not indicative of persistent paralysis. The root aggregation sign suggested the existence of significant cauda equina injuries.
Subject(s)
Humans , Action Potentials , Cauda Equina , Conus Snail , Electrodiagnosis , Magnetic Resonance Imaging , Neural Conduction , Paralysis , Paraplegia , Prognosis , Rehabilitation , Retrospective Studies , Spinal Injuries , Tibial NerveABSTRACT
Although numerous reports have found accessory or supernumerary muscles throughout the human body, multiple appearances of these variations biased toward one side of body are rare. We report a 76-yr-old male cadaver with an accessory head of the biceps brachii and palmaris profundus, and a muscular slip between the biceps femoris and semitendinosus on the left side in addition to a bilateral accessory belly of the digastric muscle. No remarkable nervous, vascular, or visceral variation accompanied these variations. An interruption of normal somitogenesis or myogenesis may be a cause of these variations.
Subject(s)
Aged , Humans , Male , Cadaver , Lower Extremity , Muscle, Skeletal/pathology , Neck , Upper ExtremityABSTRACT
OBJECTIVE: The purpose of this study was to correlate permeability parameters measured with dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) using a clinical 3-tesla scanner with extravasation of Evans blue in a rat model with transient cerebral ischemia. MATERIALS AND METHODS: Sprague-Dawley rats (n = 13) with transient middle cerebral artery occlusion were imaged using a 3-tesla MRI with an 8-channel wrist coil. DCE-MRI was performed 12 hours, 18 hours, and 36 hours after reperfusion. Permeability parameters (K(trans), v(e), and v(p)) from DCE-MRI were calculated. Evans blue was injected after DCE-MRI and extravasation of Evans blue was correlated as a reference with the integrity of the blood-brain barrier. Correlation analysis was performed between permeability parameters and the extravasation of Evans blue. RESULTS: All permeability parameters (K(trans), v(e), and v(p)) showed a linear correlation with extravasation of Evans blue. Among them, K(trans) showed highest values of both the correlation coefficient and the coefficient of determination (0.687 and 0.473 respectively, p < 0.001). CONCLUSION: Permeability parameters obtained by DCE-MRI at 3-T are well-correlated with Evans blue extravasation, and K(trans) shows the strongest correlation among the tested parameters.
Subject(s)
Animals , Male , Rats , Blood-Brain Barrier/pathology , Capillary Permeability , Contrast Media , Disease Models, Animal , Evans Blue/analysis , Ischemic Attack, Transient/diagnosis , Magnetic Resonance Imaging/instrumentation , Rats, Sprague-Dawley , Stroke/diagnosisABSTRACT
BACKGROUND/AIMS: Obstructive sleep apnea is becoming more important in gastroesophageal reflux disease (GERD) patients. This study investigated the prevalence of high risk for obstructive sleep apnea in GERD patients in comparison with that in healthy controls using the Berlin Questionnaire. We also investigated the risk factors for obstructive sleep apnea in GERD patients. METHODS: We enrolled 1,007 subjects: 776 healthy controls, 115 individuals with erosive reflux disease, and 116 with non-erosive reflux disease. GERD was diagnosed and classified using endoscopy and a reflux questionnaire. The Berlin Questionnaire was used to evaluate obstructive sleep apnea. RESULTS: More patients in the GERD group (28.2%) had higher risk for obstructive sleep apnea than healthy controls (20.4%, P = 0.036). More patients with non-erosive disease (32.8%) had higher risk for obstructive sleep apnea (OSA) than patients with erosive disease (20.9%) and controls (20.4%, P = 0.010). On multivariate analysis, non-erosive disease was a high risk factor for obstructive sleep apnea (odds ratio [OR], 1.82; P = 0.011). Age > or = 55 years (OR, 1.83; P or = 25 kg/m2) (OR, 2.76; P or = 55, and a high BMI are associated with high risk for OSA.
Subject(s)
Humans , Berlin , Body Mass Index , Endoscopy , Esophagitis , Gastroesophageal Reflux , Multivariate Analysis , Prevalence , Surveys and Questionnaires , Risk Factors , Sleep Apnea, ObstructiveABSTRACT
Neurofibromatosis type I is a genetic disease caused by mutations in the neurofibromin 1 (NF1) gene. Although it is characterized by a number of distinct clinical features, including cafe au lait macules, freckling in the axillary or inguinal regions, neurofibromas, and Lisch nodules (iris harmartomas), it can affect all physiological systems in the body [1]. Neurofibromatosis-related pulmonary hypertension has also been reported, and some patients showed a poor prognosis despite having received proper medical treatment [2-4]. We herein describe a case of pulmonary hypertension in a patient with neurofibromatosis type I who had no identified risk factors of pulmonary hypertension. To our knowledge, this is the first such report in Korea.
Subject(s)
Humans , Hypertension , Hypertension, Pulmonary , Korea , Neurofibroma , Neurofibromatoses , Neurofibromatosis 1 , Neurofibromin 1 , Prognosis , Risk FactorsABSTRACT
Neurofibromatosis type I is a genetic disease caused by mutations in the neurofibromin 1 (NF1) gene. Although it is characterized by a number of distinct clinical features, including cafe au lait macules, freckling in the axillary or inguinal regions, neurofibromas, and Lisch nodules (iris harmartomas), it can affect all physiological systems in the body [1]. Neurofibromatosis-related pulmonary hypertension has also been reported, and some patients showed a poor prognosis despite having received proper medical treatment [2-4]. We herein describe a case of pulmonary hypertension in a patient with neurofibromatosis type I who had no identified risk factors of pulmonary hypertension. To our knowledge, this is the first such report in Korea.
Subject(s)
Humans , Hypertension , Hypertension, Pulmonary , Korea , Neurofibroma , Neurofibromatoses , Neurofibromatosis 1 , Neurofibromin 1 , Prognosis , Risk FactorsABSTRACT
PURPOSE: We evaluated the results of more than 10 years of follow-up of total hip arthroplasty using a second-generation cementless femoral prosthesis with a collar and straight distal fixation channels. MATERIALS AND METHODS: One hundred five patients (129 hips) who underwent surgery between 1991 and 1996 for primary total hip arthroplasty using cementless straight distal fluted femoral stems were followed for more than 10 years. Ninety-four hips in 80 patients were available for clinical and radiologic analysis. The mean age at the time of surgery was 47 years, and the mean duration of follow-up was 14.3 years. RESULTS: The mean Harris hip scores had improved from 58 points to 88 points at the time of the 10-year follow-up. Activity-related thigh pain was reported in nine hips (10%). At the last follow-up, 93 stems (99%) were biologically stable and one stem (1%) was revised because of loosening. No hip had distal diaphyseal osteolysis. Proximal femoral stress-shielding was reported in 86 hips (91%). We found no significant relationship between collar-calcar contact and thigh pain, stem fixation status, or stress-shielding. The cumulative survival of the femoral stem was 99% (95% confidence interval, 98-100%) after 10 years. CONCLUSION: The long-term results of total hip arthroplasty using a second-generation cementless femoral prosthesis with a collar and straight distal fixation channels were satisfactory; however, the high rate of proximal stress-shielding and the minimal effect of the collar indicate the need for some changes in the stem design.
Subject(s)
Adult , Aged , Female , Humans , Male , Middle Aged , Arthroplasty, Replacement, Hip/instrumentation , Bone Cements , Femoral Neck Fractures/diagnostic imaging , Femur Head Necrosis/diagnostic imaging , Follow-Up Studies , Hip Prosthesis , Osteoarthritis, Hip/diagnostic imaging , Time Factors , Treatment OutcomeABSTRACT
PURPOSE: We hypothesized that comprehensive neck dissection could be achieved via a gasless transaxillary approach using a robotic system. We intended to evaluate the accessibility of level I, IIB and VA nodes with transaxillary robot-assisted neck dissection of four cadavers. MATERIALS AND METHODS: Transaxillary robotic neck dissection was performed in four cadavers through a 7-cm longitudinal incision at the anterior axilla and a 0.8-cm-sized incision in the chest wall. RESULTS: We successfully performed neck dissection from level II to V in all four cadavers. However, dissection of levels IIB and VA, which lie on the cephalic portion of the spinal accessory nerve, was difficult. Vital structures, including the internal jugular vein, carotid artery, vagus nerve, phrenic nerve, superior thyroid artery and hypoglossal nerve, were successfully identified and preserved. CONCLUSION: Our results demonstrate the feasibility of robot-assisted neck dissection using a transaxillary approach. We suggest that gasless, transaxillary robotic neck dissection is a promising technique for treating nodal metastasis in thyroid cancers or in selected squamous cell carcinomas of the head and neck. However, some modification of the approach might be needed when performing comprehensive neck dissections of all levels of the neck.
Subject(s)
Female , Humans , Male , Cadaver , Endoscopy/instrumentation , Feasibility Studies , Head and Neck Neoplasms/surgery , Neck/blood supply , Neck Dissection/instrumentation , Neoplasms, Squamous Cell/surgery , Robotics/methods , Thyroid Neoplasms/surgeryABSTRACT
Saccharomyces cerevisiae, also known as "baker's yeast" or "brewer's yeast", and is considered to be a frequent colonizer of human mucosal surfaces. Although it is a very uncommon cause of infections in humans, it can cause wide range of clinical syndromes, including pneumonia, empyema, liver abscess, peritonitis, urinary tract infection, cellulitis, unexplained fever, or septic shock, particularly in immunocompromised hosts. Fungemia is the most severe and well-proven manifestation of S.cerevisiae infections. According to previous studies, the conditions related to immunosupression, such as cancer, HIV infection, use of corticosteroid, neutropenia, stem cell transplantation, solid organ transplantation, burns and heart surgery, appear to be predisposing factors to fungemia. The antifungal agent of choice has not been established. We report two cases of S.cerevisiae fungemia in patients with hematologic malignancies. One was primary fungemia, and the other was presumed to be a catheter related one. Both cases showed a good prognosis with the complete negative conversion of fungemia.
Subject(s)
Humans , Burns , Catheters , Cellulitis , Colon , Empyema , Fever , Fungemia , Hematologic Neoplasms , HIV Infections , Immunocompromised Host , Liver Abscess , Neutropenia , Organ Transplantation , Peritonitis , Pneumonia , Prognosis , Saccharomyces , Saccharomyces cerevisiae , Shock, Septic , Stem Cell Transplantation , Thoracic Surgery , Transplants , Urinary Tract InfectionsABSTRACT
Patent ductus arteriosus (PDA) is a rare clinical finding in adult patients. Considering the increase in cases of PDA discovered incidentally on echocardiograms at young ages, and the life-shortening effect of PDA, it is rare to diagnose PDA in old patients. We report a case of an 80-year-old patient who experienced symptoms of congestive heart failure showed findings suggestive of PDA in echocardiogram and confirmed the diagnosis through a cardiac catheterization and a coronary angiography. After percutaneous occlusion of PDA with an Amplatzer duct occlusion device, symptoms related to congestive heart failure improved.
Subject(s)
Adult , Aged , Humans , Cardiac Catheterization , Cardiac Catheters , Coronary Angiography , Ductus Arteriosus, Patent , Estrogens, Conjugated (USP) , Heart FailureABSTRACT
BACKGROUND: The aim of this study was to analyze clinical situations requiring rigid bronchoscopy and evaluate usefulness of rigid bronchoscopic intervention in benign or malignant airway disorders. METHODS: We retrospectively reviewed 29 patients who underwent rigid bronchoscopy from November 2007 to February 2011 at St. Paul's Hospital, The Catholic University of Korea School of Medicine. RESULTS: Of the 29 patients, the most frequent underlying etiology was benign stenosis of trachea (n=20). Of those 20 patients, 16 had post-intubation tracheal stenosis (PITS), 2 had tracheal stenosis due to inhalation burn (IBTS) and other 2 had obstructive fibrinous tracheal pseudomembrane (OFTP). Other etiologies were airway malignancy (n=6), endobronchial stenosis due to tuberculosis (n=2), and foreign body (n=1). For treatment, silicone stent insertion was done in 16 cases of PITS and IBTS and mechanical removal was performed in 2 cases of OFTP. In 6 cases of malignant airway obstruction mechanical debulking was performed and silicone stents were inserted additionally in 2 cases. Balloon dilatation and electrocautery were used in 2 cases of endobronchial stenosis due to tuberculosis. In all cases of stent, airway obstructive symptom improved immediately. Granulation tissue formation was the most common complication. CONCLUSION: Tracheal stenosis was most common indication and silicone stenting was most common procedure of rigid bronchoscopy in our center. Rigid bronchoscopic procedures, at least tracheal silicone stenting, should be included in pulmonary medicine fellowship programs because it is a very effective and indispensable method to relieve critical airway obstruction which needs training to learn.