Pyoderma Gangrenosum Mimicking Wound Infection after Breast Cancer Surgery / 한국유방암학회지

Postoperative pyoderma gangrenosum (PPG) is rare, and its diagnosis is often delayed because of its wound infection-mimicking course. A 53-year-old breast cancer patient who underwent breast-conserving surgery of the right breast presented with fever, leukocytosis, C-reactive protein elevation, and redness of the right breast on postoperative day (POD) 3. The breast wound showed desquamation with painful ulcerative changes from POD 6, and fever was sustained under antibiotic administration. Wound irrigation was attempted; however, inflammatory skin damage progressed to involvement of the entire skin overlying the breast. With clinical suspicion of PPG, skin biopsy and systemic corticosteroid initiation were performed on POD 12. Wound damage progression ceased, and the systemic inflammation subsided. The patient underwent split-thickness skin grafting under intravenous corticosteroid administration, and the wound healed after 30 days. PPG is a rare clinical scenario. Early diagnosis is critical to avoid unnecessary treatment and aggravation of the surgical wound.

Pyoderma Gangrenosum Mimicking Wound Infection after Breast Cancer Surgery / 한국유방암학회지

Postoperative pyoderma gangrenosum (PPG) is rare, and its diagnosis is often delayed because of its wound infection-mimicking course. A 53-year-old breast cancer patient who underwent breast-conserving surgery of the right breast presented with fever, leukocytosis, C-reactive protein elevation, and redness of the right breast on postoperative day (POD) 3. The breast wound showed desquamation with painful ulcerative changes from POD 6, and fever was sustained under antibiotic administration. Wound irrigation was attempted; however, inflammatory skin damage progressed to involvement of the entire skin overlying the breast. With clinical suspicion of PPG, skin biopsy and systemic corticosteroid initiation were performed on POD 12. Wound damage progression ceased, and the systemic inflammation subsided. The patient underwent split-thickness skin grafting under intravenous corticosteroid administration, and the wound healed after 30 days. PPG is a rare clinical scenario. Early diagnosis is critical to avoid unnecessary treatment and aggravation of the surgical wound.

Effects of Injection Laryngoplasty with Hyaluronic Acid in Patients with Vocal Fold Paralysis

OBJECTIVES: The purpose of this study was to explore the effects of injection laryngoplasty (IL) with hyaluronic acid in patients with vocal fold paralysis (VFP). METHODS: A total of 50 patients with VFP participated in this study. Pre- and post-IL assessments were performed, which included analyzing the sustained vowel /a/ phonation, and the patient reading 1 Korean sentence from the “Walk” passage that comprised 25 syllables in 10 words. To investigate the effect of IL on vocal fold function, acoustic analysis (acoustic voice quality index, cepstral peak prominence, maximum phonation time, speaking fundamental frequency) was conducted and auditory-perceptual (grade and overall severity), visual judgment (gap), and self-questionnaire (voice handicap index-10) assessments were performed. RESULTS: The patients with VFP showed statistically significant differences between pre-and post-IL assessments for acoustic and auditory-perception, visual judgment, and self-questionnaire assessments. CONCLUSION: The patients with VFP showed positive change in vocal fold function between pre- and post-IL measurements. The findings showed that IL with hyaluronic acid is an effective method to improve vocal fold function in patients with VFP.

Clinical Outcomes of Diffuse Axonal Injury According to Radiological Grade

PURPOSE@#Patients with diffuse axonal injury experience various disabilities and have a high cost of treatment. Recent researches have revealed the underlying mechanism and pathogenesis of diffuse axonal injury. This study aimed to investigate the correlation between the radiological grading of diffuse axonal injury and the clinical outcomes of patients.@*METHODS@#From January 2011 to December 2016, among 294 patients with traumatic brain injury, 44 patients underwent magnetic resonance imaging (MRI). A total of 18 patients were enrolled in this study except for other cerebral injuries, such as cerebral hemorrhage or hypoxic brain damage. Demographic data, clinical data, and radiological findings were retrospectively reviewed. The grading of diffuse axonal injury was analyzed based on patient's MRI findings.@*RESULTS@#For the most severe diffuse axonal injury patients, prolonged intensive care unit (ICU) stay (p=0.035), hospital stay (p=0.012), and prolonged mechanical ventilation (p=0.030) were observed. However, there was no significant difference in healthcare-associated infection rates between MRI grading (p=0.123). Massive transfusion, initial hemoglobin and lactate levels, and MRI gradings were found to be highly significant in predicting the duration of unconsciousness.@*CONCLUSIONS@#This study showed that patients with high grade diffuse axonal injury have prolonged ICU stays and significantly longer hospital stays. Deteriorated mental patients with high energy injuries should be evaluated to identify diffuse axonal injuries by using an appropriate imaging tool, such as MRI. It will be important to predict the duration of consciousness recovery using MRI scans.

Three-Dimensional Ground Glass Opacity Ratio in CT Images Can Predict Tumor Invasiveness of Stage IA Lung Cancer

PURPOSE: We investigated the relationship between various parameters, including volumetric parameters, and tumor invasiveness according to the International Association for the Study of Lung Cancer (IASLC)/American Thoracic Society (ATS)/European Respiratory Society (ERS) classification. MATERIALS AND METHODS: We retrospectively reviewed 99 patients with completely resected stage IA lung adenocarcinoma. The correlation between several parameters [one-dimensional ground glass opacity (1D GGO) ratio, two-dimensional (2D) GGO ratio, three-dimensional (3D) GGO ratio, 1D solid size, 2D solid size, and 3D solid size] and tumor invasiveness according to IASLC/ATS/ERS classification was investigated using receiver operating characteristic (ROC) analysis. Adenocarcinoma in situ and minimally invasive adenocarcinoma were referred to as noninvasive adenocarcinoma. RESULTS: The areas under the curve (AUC) to predict invasive adenocarcinoma for the 1D, 2D, and 3D GGO ratios were 0.962, 0.967, and 0.971, respectively. The optimal cut-off values for the 1D, 2D, and 3D GGO ratios were 38%, 62%, and 74%, respectively. The AUC values for 1D, 2D, and 3D solid sizes to predict invasive adenocarcinoma were 0.933, 0.944, and 0.903, respectively. The optimal cut-off values for 1D, 2D, and 3D solid sizes were 1.2 cm, 1.5 cm2, and 0.7 cm3, respectively. The difference in the ROC curves for 3D GGO ratio and 3D solid size was significant (p=0.01). CONCLUSION: Computed tomography image-related parameters based on GGO were well correlated with and predictive of invasiveness according to IASLC/ATS/ERS classification. 3D GGO ratio was more strongly correlated with pathologic invasiveness than 3D solid size.

Comparison of Melanoma Subtypes among Korean Patients by Morphologic Features and Ultraviolet Exposure

BACKGROUND: Genetic alterations have been identified in melanomas according to different levels of sun exposure. Whereas the conventional morphology-based classification provides a clue for tumor growth and prognosis, the new classification by genetic alterations offers a basis for targeted therapy. OBJECTIVE: The purpose of this study is to demonstrate the biological behavior of melanoma subtypes and compare the two classifications in the Korean population. METHODS: A retrospective chart review was performed on patients found to have malignant melanoma in Severance Hospital from 2005 to 2012. Age, sex, location of the tumor, histologic subtype, tumor depth, ulceration, lymph node invasion, visceral organ metastasis, and overall survival were evaluated. RESULTS: Of the 206 cases, the most common type was acral melanoma (n=94, 45.6%), followed by nonchronic sun damage-induced melanoma (n=43, 20.9%), and mucosal melanoma (n=40, 19.4%). Twenty-one patients (10.2%) had the chronic sun-damaged type, whereas eight patients (3.9%) had tumors of unknown primary origin. Lentigo maligna melanoma was newly classified as the chronic sun-damaged type, and acral lentiginous melanoma as the acral type. More than half of the superficial spreading melanomas were newly grouped as nonchronic sun-damaged melanomas, whereas nodular melanoma was rather evenly distributed. CONCLUSION: The distribution of melanomas was largely similar in both the morphology-based and sun exposure-based classifications, and in both classifications, mucosal melanoma had the worst 5-year survival owing to its tumor thickness and advanced stage at the time of diagnosis.

Integrity of human sperm DNA assessed by the neutral comet assay and its relationship to semen parameters and clinical outcomes for the IVF-ET program / 대한생식의학회지

OBJECTIVE: To explore potential relationships between sperm DNA integrity and both semen parameters and clinical outcomes. METHODS: Semen analysis of 498 samples was performed according to the 2010 criteria of the World Health Organization. The sperm DNA fragmentation Index (DFI) of the semen samples was assessed using a neutral comet assay. RESULTS: Sperm DFI showed a significant correlation with semen parameters, including the patient's age, sperm viability, motility, morphology, and number of leukocytes (p or =14% group (44 cycles, 55.3%), but there was no difference in the other clinical outcomes between the two groups. In the > or =14% group, the pregnancy rates of the ICSI cycles (40.0%) and half-ICSI (44.0%) were higher than conventional IVF cycles (30.7%), but the difference was not statistically significant. CONCLUSION: Along with the conventional semen analysis, the sperm DFI assessed using the comet assay was shown to improve the quality of the semen evaluation. To evaluate the precise effect of ICSI on pregnancy rates in the patients who demonstrate high sperm DFI values, further study is necessary.

Effect of Elderly Organized Vestibular Rehabilitation for Presbystasis / 대한평형의학회지

BACKGROUND AND OBJECTIVES: Recently, The number of patients who have been complaining of the vertigo or dizziness has been increasing due to rapid growth of the elderly population and senile change. Aging is associated with decreased balance abilities, resulting in an increased risk of fall. The purpose of this study is to analyze the result of elderly organized vestibular rehabilitation therapy for presbystasis. MATERIALS AND METHODS: A prospective study was performed on elderly population over sixty-five years. 148 dizzy patients who were admitted to Hallym University Medical Center. We recruited 64 consecutive patients with a diagnosis of presbystasis and treatment of rehabilitation. They were asked to complete the Korean vestibular disorders activities of daily living scale (K-VADL) for the functional aspect before and two to twelve weeks after elderly organized vestibular rehabilitation therapy. The result was analyzed by statistical methods. RESULTS: The K-VADL scores were decreased in patient of presbystasis compared with first questionnaire. There were statistically significant differences in the K-VADL scores between before and after rehabilitation therapy. CONCLUSION: Most patients can effectively and safely utilize the modified vestibular rehabilitation therapy. Our results suggest that the vestibular rehabilitation therapy could provide a recovery for dizzy symptoms in presbystasis.

Streptococcus salivarius pneumonia with pulmonary nocardiosis in a rheumatoid arthritis patient treated with immunosuppressants / 대한내과학회지

Streptococcus salivarius is a Gram-positive organism that belongs to the viridians group of streptococci. It is a relatively non-virulent bacterium that is part of the normal flora. It is rarely isolated from blood and is usually considered a contaminant. Nevertheless, S. salivarius may cause life-threatening infections, especially in immunocompromised hosts. There have been relatively few reports of S. salivarius pneumonia. Nocardiosis is also a rare opportunistic infection. Pulmonary nocardiosis is difficult to diagnose and, consequently, the diagnosis is often delayed. We report an unusual presentation with multiple pulmonary mass-like consolidations caused by a mixed infection of S. salivarius and Nocardia sp. in a 58-year-old man with rheumatoid arthritis who was taking oral corticosteroid, methotrexate, and leflunomide. The patient's symptoms and radiographic findings improved after six weeks of antibiotic therapy

The diagnostic accuracy of notified new culture-negative pulmonary tuberculosis patients in public healthcare centers / 대한내과학회지

BACKGROUND/AIMS: The notification rate based on the Korean tuberculosis (TB) surveillance system has been widely used to evaluate the TB burden in Korea. However, few studies have examined the accuracy of TB diagnosis among notified cases. This study evaluated the diagnostic accuracy of microbiologically not proven cases notified as 'new pulmonary TB patients' at public healthcare centers. METHODS: We reviewed the clinical symptoms and initial and follow-up chest radiographs of notified smear-and-culture- negative TB cases in randomly selected healthcare centers between Jan 2005 and Dec 2005. Patients who had symptoms, initial chest radiographs compatible with pulmonary TB, and radiological improvements after treatment were diagnosed as 'probable TB', while patients who did not meet these three criteria were diagnosed as 'probably not TB'. RESULTS: The analysis included 263 patients. The median age of the notified TB cases was 41 years, 60.8% of them were male, and 43.2% were 'probable TB' patients. Overall, 82.0% of the patients had either initial chest radiographs compatible with pulmonary TB or radiological improvements after treatment. Ultimately, 4.9% were 'probably not TB' patients. CONCLUSIONS: Most of the new notified pulmonary TB patients not confirmed microbiologically in public clinics can be considered real TB patients, although there are some over diagnosed cases.

Prognostic Significance of Ezrin Expression in Liposarcoma

BACKGROUND: Ezrin has been reported to be involved in the metastasis of solid tumors in both an animal model and clinical trials. However, questions remains as to whether an ezrin expression is an independent predictor of the event-free survival of liposarcoma patients. METHODS: We analyzed 85 liposarcoma patients without metastasis at the time of presentation. We performed immunohistochemistry with anti-ezrin antibody, and we analyzed the association of an ezrin expression with the clinicopathological variables and event-free survival. RESULTS: Twenty-nine patients (34.1%) showed an ezrin expression. Among the 30 low-grade liposarcoma patients, only one patient showed ezrin positivity. The patients who had an ezrin expression were found to be at a significantly increased risk for metastasis compared with the patients who had no ezrin expression (risk ratio: 3.4, 95% confidence interval: 1.3-9.1). The 10-year metastasis-free survival rate was 26.9% for the patients with an ezrin expression and 86.7% for the patients without an ezrin expression. The ezrin expression rate increased with an advanced tumor grade and stage. CONCLUSION: An ezrin expression is an independent predictor of distant metastasis for liposarcoma. Thus, ezrin has the potential to provide additional prognostic information and to be a novel target for the development of new adjuvant therapies for treating the patients who suffer from liposarcoma.

Consolidative Bronchioloalveolar Carcinoma Presenting as Pneumonia, and This Led to a Late Diagnosis due to the Improvement after Antibiotic Therapy / 결핵및호흡기질환

Non-resolving or slowly resolving pulmonary infiltrates in spite of administering adequate antimicrobial therapy are a clinical diagnostic challenge for physicians. The rate of radiographic resolution varies with the patients' age, the underlying comorbidities, the extent of radiographic involvement, the functional status and the causal pathogens. It is important to differentiate non-resolving or slowly resolving bacterial pneumonia from other uncommon infectious pneumonias or malignancies that require invasive diagnostic techniques to confirm the diagnosis. Bronchioloalveolar carcinoma can present with various clinical and radiographic features. Unfortunately, the radiographic similarity of consolidative BAC to pneumonia often leads to an incorrect diagnosis of pneumonia and possibly significant delays in obtaining appropriate diagnostic studies. We describe here a case of a mixed adenocarcinoma and bronchioloalveolar carcinoma that was initially diagnosed as pneumonia due to the consolidation pattern on the radiography and the patient's initial improvement with antibiotic treatment.

The Incidence and Clinical Implication of Sputum with Positive Acid-Fast Bacilli Smear But Negative in Mycobacterial Culture in a Tertiary Referral Hospital in South Korea

Although it is not rare to find sputum that is positive acid-fast bacilli (AFB) smear but subsequent culture fails to isolate mycobacteria in clinical practice, the incidence and clinical implication of those sputa from new patients has not been clearly elucidated. The aim of this study was to determine the incidence and clinical implication of sputum with positive AFB smear but negative in mycobacterial culture. All sputa that were positive AFB smear requested during diagnostic work up for new patients visiting Seoul National University Hospital from 1 January 2005 through 31 December 2006 were included. Sputa producing a positive AFB smear but negative mycobacterial culture were classified into one of four categories: laboratory failure to isolate mycobacteria, false positive AFB smear, pathogen may show a positive AFB smear other than mycobacteria, and indeterminate results. Out of 447 sputa with a positive AFB smear, 29 (6.5%) failed to culture any organism. Among these 29 sputa, 18 were caused by laboratory failure to isolate mycobacteria, six were false positive smears, and five indeterminate. Although most sputum with a positive AFB smear but negative culture could be classified as a laboratory failure, clinicians should consider the possibility of false positive AFB smear.

A Case of Bilateral Gynecomastia Associated with Isoniazid / 결핵및호흡기질환

Gynecomastia is a benign enlargement of the male breast attributable to proliferation of the ductal elements. Gynecomastia has been rarely reported as an adverse effect of isoniazid therapy. We report the case of a 35-year-old man who was prescribed with isoniazid, rifampicin, ethambutol and pyrazinamide to treat pulmonary and lymphatic tuberculosis. After five months of treatment, the patient complained of painful engorgement in the bilateral breasts and the presence of male gynecomastia was confirmed with a physical examination and radiographical methods. The serum level of estradiol was also increased. Common causes of male gynecomastia were excluded through history taking and the laboratory findings. The anti-TB drugs were changed to a second line regimen due to radiographical progression and the intolerance of the patient to gynecomastia. Gynecomastia was relieved very slowly and a tender subareolar palpable mass decreased in size and consistency over five-month period after stopping the probable causative drug, isoniazid. From a review of the literature, gynecomastia has been shown to be a side effect of treatment with first line anti-tuberculosis drugs, and especially with isoniazid. We report the rare case.

Sclerosing Mucoepidermoid Carcinoma of the Parotid Gland / 대한이비인후과학회지

Sclerosing mucoepidermoid carcinoma of salivary gland is a rare variant of mucoepidermoid carcinoma and can be confused with benign condition on clinical, radiological, and pathologic examination. A 34-year old female was found to have a parotid mass with a long history. Preoperative evaluation including computed tomography and fine needle aspiration cytology were nondiagnostic. Intraoperatively, frozen section specimens showed only low grade tubular lesion with severe background inflammatory infiltration. Final pathological examination demonstrated multiple cystic nests composed of mucinous and squamoid intermediate cells within the background of central dense, sclerotic, collagenized stroma and peripheral inflammatory infiltrate, consistent with a low grade sclerosing mucoepidermoid carcinoma. Sclerosing mucoepidermoid carcinoma is a very rare salivary gland tumor with an uncertain clinical behavior. Complete surgical excision with tumor-free margins is recommended. Postoperative radiation therapy is suggested for positive or close margins, and close follow-up of the patients is mandatory.

Parosteal Ossifying Lipoma of Femur: A Case Report

Parosteal lipoma is a rare and generally asymptomatic benign tumor of mature adipose tissue that is located in direct apposition to the external surface of the bone. These tumors are occasionally associated with reactive changes in the underlying bone. The reactive bone formation is generally restricted to the base of the tumor, that is, near the periosteum. We recently experienced a case of parosteal lipoma in the proximal femur, which displayed exuberant bone and cartilage formation, and this led us to a misdiagnosis of chondroblastic osteosarcoma on the initial biopsy. We report here on this case with a special emphasis on making the differential diagnosis from osteosarcoma.

The Changing Pattern of Serum Prostate Specific Antigen in Patients with Benign Prostatic Hyperplasia after Combined Treatment with Finasteride and alpha-blockers: the 3 Year Follow-up Data / 대한비뇨기과학회지

PURPOSE: Some recent studies have demonstrated that finasteride, a well- known 5alpha-reductase inhibitor, can decrease prostate specific antigen (PSA) by approximately 50% during the first 1 year of treatment. We investigated how long-term treatment with finasteride and alpha-blockers impacts on the serum PSA level of men whose final diagnosis was benign prostatic hyperplasia (BPH). MATERIALS AND METHODS: In a retrospective trial, we evaluated a total of 293 men with lower urinary tract symptoms (LUTS) that were suggestive of BPH. These men were divided into two treatment groups: group A was treated with alpha-blockers and group C was treated with a combination of finasteride and alpha-blocker. Comparisons of the two groups were performed by using independent t-tests. The changes in the PSA concentrations from baseline to the time of the final measurements were determined by repeated measures of ANOVA. RESULTS: There was no significant difference in the baseline PSA between the two groups. A statistically significant reduction in the PSA levels was observed at 2 years in C group (p0.05). In group A, the repeatedly measured PSA levels were 2.67, 2.40, 2.41 and 2.42, respectively. In C group, these were 3.22, 2.09, 1.81 and 1.71 respectively. CONCLUSIONS: Our data showed that there was no clinically significant effect of long term treatment with alpha-blocker on the PSA levels. However, finasteride had significant effect on the serum PSA level during first two years of treatment.

Internet Based Multi-institute Prostate Research System: Pilot Experience with a Convenient, Secure and Efficient System / 대한비뇨기과학회지

PURPOSE: The process of transferring data from one medical center to another and sharing the results can be time-consuming and inconvenient. So, we introduce the multi-institutional clinical research that uses the Internet for conducting faster, safer and more convenient research. MATERIALS AND METHODS: Patients with benign prostatic hyperplasia (BPH) were prospectively enrolled from 3 remote participating medical centers by means of the Internet. When a patient with BPH came to the hospital, the BPH profile, medications and adverse events were entered into the Internet Based Multi-institute Prostate Research System (IBMPRS). Six investigators were educated on the use of the IBMPRS and we measured the mean data entering time and the user satisfaction. RESULTS: 763 patients with BPH from three institutions were enrolled and their data was collected through the Internet for 1 year. It took an average of 2 minutes 43 seconds to enter the information of one patient. All the investigators were satisfied about the IBMPRS and the system was very stable and safe. CONCLUSIONS: An Internet-based clinical research system has the advantage of being able to instantly share patient information and full-time access to the interim results is available if a large number of institutions participate in the clinical research. Clinical research using the Internet would be an invaluable method that is free to use with easy accessibility, and it could play the role of an excellent secretary on the web.

Early Experience on the Effects of Sildenafil Citrate for Treating Erectile Dysfunction after Radical Retropubic Prostatectomy / 대한비뇨기과학회지

PURPOSE: We assess the efficacy of using sildenafil for treating erectile dysfunction (ED) in Korean men after they had undergone radical retropubic prostatectomy for localized prostate cancer. MATERIALS AND METHODS: Between January 2002 and November 2004, 61 patients underwent RRP and post-operative sildenafil treatment for ED, and 50 patients were finally enrolled in this study. The subjects were divided into three groups according to the nerve sparing status (non-nerve sparing, unilateral nerve sparing and bilateral nerve sparing). Medication was initiated at 50mg, and if this was ineffective, then we added 50mg to the initial dosage. The patients were asked to fill out the self-administrated International Index of Erectile Function-5 (IIEF-5) for determining their response to sildenafil. RESULTS: Of the 14 patients who underwent bilateral nerve sparing (NS) procedures, 4 (28%) had improved ability for intercourse. Of the 8 patients who underwent unilateral NS procedures, 2 (25%) had improved ability for intercourse. 1 of 28 patients who underwent non-NS procedures had a positive response. PDE5Is significantly improved the IIEF-5 (2.44+/-1.89 vs 8.81+/-8.24, respectively, p<0.001). Two factors, i.e., age and preoperative sexual activity, correlated with the return of sexual function. No patient discontinued the drug because of side effects. CONCLUSIONS: For Korean men who have undergone bilateral and unilateral NS procedures, Sildenafil is effective for treating erectile dysfunction, and it may aid the recovery of erectile function after radical retropubic prostatectomy. However, non-NS procedure patients had less of a response to sildenafil. This study suggested that sildenafil is well tolerated and could be initially used for treating Korean men with erectile dysfunction after radical retropubic prostatectomy.

Frequency-Doubled Double-Pulse Nd:YAG (FREDDY) Laser for the Treatment of Ureteral Stone: Initial Experience / 대한비뇨기과학회지

PURPOSE: We assessed the effectiveness, safety and accessibility of performing FREDDY laser lithotripsy for managing urinary tract calculi. MATERIALS AND METHODS: From January 1999 to May 2005, 173 consecutive patients underwent endoscopic lithotripsy with FREDDY laser lithotripsy. The numbers of patients, according to stone location, were 18 patients for the upper ureter, 11 for the mid ureter and 144 for the lower ureter. Patients were treated with a rigid endoscope on a day surgery basis. Patients were assessed 6 to 12 weeks postoperatively with KUB and ultrasound or excretory urography for determining the late obstructive complications. RESULTS: The mean stone size and mean operation time were 7.8mm and 36.6 minutes, respectively. The overall stone-free rates were 98.9%. The stone-free rates according to stone location were 100% in the upper ureter, 100% in the mid ureter and 98.6% in the lower ureter. There were no post-operative complications. Interestingly, there were no significant differences in the operation times and stone-free rates between the urologic specialists (36.7 min and 100%, respectively) and the training residents (37.1 min and 98.6%, respectively). CONCLUSIONS: FREDDY laser lithotripsy is a highly effective and safe modality for the treatment of ureteral stone. In addition, FREDDY laser lithotripsy is very feasible for training residents.