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Featured researches published by Sang Hyeon Cheon.


Yonsei Medical Journal | 2015

The Effects of Different Noise Types on Heart Rate Variability in Men

Chang Sun Sim; Joo Hyun Sung; Sang Hyeon Cheon; Jang Myung Lee; Jaewon Lee

Purpose To determine the impact of noise on heart rate variability (HRV) in men, with a focus on the noise type rather than on noise intensity. Materials and Methods Forty college-going male volunteers were enrolled in this study and were randomly divided into four groups according to the type of noise they were exposed to: background, traffic, speech, or mixed (traffic and speech) noise. All groups except the background group (35 dB) were exposed to 45 dB sound pressure levels. We collected data on age, smoking status, alcohol consumption, and disease status from responses to self-reported questionnaires and medical examinations. We also measured HRV parameters and blood pressure levels before and after exposure to noise. The HRV parameters were evaluated while patients remained seated for 5 minutes, and frequency and time domain analyses were then performed. Results After noise exposure, only the speech noise group showed a reduced low frequency (LF) value, reflecting the activity of both the sympathetic and parasympathetic nervous systems. The low-to-high frequency (LF/HF) ratio, which reflected the activity of the autonomic nervous system (ANS), became more stable, decreasing from 5.21 to 1.37; however, this change was not statistically significant. Conclusion These results indicate that 45 dB(A) of noise, 10 dB(A) higher than background noise, affects the ANS. Additionally, the impact on HRV activity might differ according to the noise quality. Further studies will be required to ascertain the role of noise type.


Korean Journal of Urology | 2012

Comparison of Surgical Outcomes between Dismembered Pyeloplasty with or without Ureteral Stenting in Children with Ureteropelvic Junction Obstruction

June Kim; Sungchan Park; Hyunho Hwang; Jongwon Kim; Sang Hyeon Cheon; Seonghun Park; Kun Suk Kim

Purpose To evaluate the impact of temporary internal ureteral stents on the surgical outcomes of dismembered pyeloplasty in children. Materials and Methods The medical records of 70 children (76 renal units) who underwent dismembered pyeloplasty for ureteropelvic junction (UPJ) obstruction at at Asan Medical Center between January 2005 and December 2010 were retrospectively reviewed. We classified the renal units into the stented group (22 renal units) and the nonstented group (54 renal units). Fifty-four of 70 patients were male and their mean age was 2.2±3.8 years old. The mean follow-up period was 29.6±16.8 months. Results Sixty-four children had unilateral UPJ obstruction. The mean stent duration was 31.9 days. As shown by evaluation of radiologic images, there were no significant differences between the stented group and the nonstented group during the follow-up period (p>0.05). The mean preoperative and postoperative anteroposterior pelvic diameters (APPDs) of the nonstented group were 31.3 mm and 15.1 mm, respectively (p<0.001). The preoperative and postoperative grades of hydronephrosis were 3.9 and 2.9, respectively (p=0.037). The mean preoperative and postoperative APPDs of the stented group were 36.4 mm and 15.6 mm, respectively (p<0.001). The preoperative and postoperative grades of hydronephrosis were 4 and 3.1, respectively (p<0.001). Repeat obstruction was shown in 4 subjects as a postoperative complication (5.7%). Two children from each group had recurrent UPJ obstruction, with percentages of 3.7% and 9%, respectively (p=0.575). Conclusions In a comparison of nonstented and stented groups during pediatric dismembered pyeloplasty for UPJ obstruction, no significant differences were found in the resolution of hydronephrosis or overall postoperative complications.


Korean Journal of Urology | 2012

Change in Penile Length in Children: Preliminary Study

Joong Ho Lee; Young Hwan Ji; Seung Kyu Lee; Hyun Ho Hwang; Dong Soo Ryu; Kun Suk Kim; Hyun Soo Choo; Seonghun Park; Kyung Hyun Moon; Sang Hyeon Cheon; Sungchan Park

Purpose Studies of penile length in children have been rarely conducted. In Korea, great improvements in height and weight have been observed because of economic development over the past 25 years. We investigated the current status of penile length in Korean children and compared the results with those of a previous Korean study conducted in 1987. Materials and Methods The subjects in this study were 233 boys aged 1 to 158 months, each of whom had been brought to outpatient clinics between April and October 2011. Penile length was measured according to the stretched penile length (SPL) technique; testicular size was measured (in ml) by using orchidometry. A comparison of penile lengths between the current study and the 1987 study was made by using Students t-test. Results SPL increased significantly by 0.7 to 1.1 cm in most age groups (p<0.05). Current anthropometric measures of Korean children such as height, body weight, and testicular size have increased compared with those from 1987. Conclusions Penile length has increased significantly over the last quarter century. Therefore, it is suggested that novel reference values for penile length in prepubertal Korean children be determined in studies with a larger community-based population in order to diagnose and treat size-related penile disorders.


Korean Journal of Urology | 2015

Penile length, digit length, and anogenital distance according to birth weight in newborn male infants

Jaeyoung Park; Gina Lim; Ki Won Oh; Dong Soo Ryu; Seonghun Park; Jong Chul Jeon; Sang Hyeon Cheon; Kyung Hyun Moon; Sejun Park; Sungchan Park

Purpose Anogential distance (AGD) and the 2:4 digit length ratio appear to provide a reliable guide to fetal androgen exposure. We intended to investigate the current status of penile size and the relationship between penile length and AGD or digit length according to birth weight in Korean newborn infants. Materials and Methods Between May 2013 and February 2014, among a total of 78 newborn male infants, 55 infants were prospectively included in this study. Newborn male infants with a gestational age of 38 to 42 weeks and birth weight>2.5 kg were assigned to the NW group (n=24) and those with a gestational age<38 weeks and birth weight<2.5 kg were assigned to the LW group (n=31). Penile size and other variables were compared between the two groups. Results Stretched penile length of the NW group was 3.3±0.2 cm, which did not differ significantly from that reported in 1987. All parameters including height, weight, penile length, testicular size, AGD, and digit length were significantly lower in the LW group than in the NW group. However, there were no significant differences in AGD ratio or 2:4 digit length ratio between the two groups. Conclusions The penile length of newborn infants has not changed over the last quarter century in Korea. With normal penile appearance, the AGD ratio and 2:4 digit length ratio are consistent irrespective of birth weight, whereas AGD, digit length, and penile length are significantly smaller in newborns with low birth weight.


Korean Journal of Urology | 2012

Preoperative Clinical Factors for Diagnosis of Incidental Prostate Cancer in the Era of Tissue-Ablative Surgery for Benign Prostatic Hyperplasia: A Korean Multi-Center Review

Changhee Yoo; Cheol Young Oh; Se Joong Kim; Sun Il Kim; Young Sig Kim; Jong Yeon Park; Do Hwan Seong; Yun Seob Song; Won Jae Yang; Hyun Chul Chung; In Rae Cho; Sung Yong Cho; Sang Hyeon Cheon; S. Hong; Jin Seon Cho

Purpose To identify potential predictive factors of incidental prostate cancer (IPca) in patients considering tissue-ablation treatment for benign prostatic hyperplasia (BPH). Materials and Methods From the 11 centers, 1,613 men who underwent transurethral resection of the prostate (TURP) or open prostatectomy were included. Before surgery, prostate biopsy was performed in all patients with prostate-specific antigen (PSA) ≥4.0 ng/ml or with abnormal digital rectal examination (DRE) findings. The patients with prostate cancer preoperatively or with PSA >20 ng/ml were excluded. As predictive factors of IPca, age, body mass index, PSA, DRE, and transrectal ultrasonography (TRUS) findings, including total prostate volume (TPV), transition zone volume (TZV), and the presence of hypoechoic lesions, were reviewed. PSA density (PSAD) and PSAD in the transition zone (PSAD-TZV) were calculated. Results IPca was diagnosed in 78 patients (4.8%). DRE findings, PSA, and TZV were independent predictive factors in the multivariate analysis. In the receiver operating characteristic curve analysis of PSA, PSAD, and PSAD-TZV, the area under the curve (AUC) was the largest for PSAD-TZV (AUC, 0.685). Conclusions IPca was detected in 4.8% of the population studied. In addition to DRE findings, the combination of TZV and PSA can be useful predictive factors of IPca in patients considering tissue-ablation treatment as well as TURP.


Korean Journal of Urology | 2011

Clinical characteristics and surgical outcomes in adolescents and adults with varicocele.

Hun Joo Lee; Sang Hyeon Cheon; Young Hwan Ji; Kyung Hyun Moon; Kun Suk Kim; Seonghun Park; Sungchan Park

Purpose To compare clinical characteristics and surgical results in adolescents and adults with varicocele. Materials and Methods We retrospectively analyzed the characteristics of 93 patients, 34 adolescents (mean age, 14.4±2.1 years) and 59 adults (mean age, 30.4±12.4 years), who underwent surgical repair of varicocele between 2006 and 2009. Median follow-up time in all patients was 18.7 months. The most bothersome symptoms, bilaterality, grades, surgical methods, artery-sparing rates, operation times, semen analysis, success rates, and recurrence-free period were compared between the two groups. Results The overall success rate of surgical repair was 92.5%. The most bothersome symptoms were scrotal mass, pain, and hypotrophy in adolescents and pain, scrotal mass, infertility, and hypotrophy in adults (p=0.008). There were no significant between-group differences in bilaterality, grades, surgical methods, operation times, pre- or postoperative semen analyses, success rates, or recurrence-free periods. Patients who underwent artery-sparing surgery had higher recurrence rates than did those who underwent surgery that did not spare arteries. In adults, semen density increased significantly after surgery, from 35.6 million/ml to 49.6 million/ml (p=0.046). Conclusions There were no significant differences in clinical characteristics or surgical results between adolescents and adults with varicocele, except for the most bothersome symptoms. Semen density increased after surgery in both groups.


Urology | 2008

Prostate-specific antigen velocity in healthy Korean men with initial PSA levels of 4.0 ng/mL or less.

Won Sik Ham; Dae Ryong Kang; Young Sig Kim; Do Hwan Seong; Se Joong Kim; Sang Hyeon Cheon; In Rae Cho; Jin Seon Cho; Chun Il Kim; Young Deuk Choi

OBJECTIVES To assess the longitudinal changes in serial prostate-specific antigen (PSA) levels in healthy Korean men with initial PSA levels of 4.0 ng/mL. METHODS The rate of PSA change or PSA velocity (PSAV) in 24 869 healthy men with an initial PSA level of 4.0 ng/mL or less who were clinically free of genitourinary disease was analyzed at intervals of at least 12 months. The influence of age, initial PSA level, and the interval between measurements was assessed. RESULTS The mean age, initial PSA level, interval between measurements, and change in PSA and PSAV was 46.2 years, 0.86 ng/mL, 21.9 months, and 0.03 ng/mL and 0.02 ng/mL/y, respectively. A cumulative frequency plot of PSAV demonstrated that 50%, 95%, and 97% of subjects had a PSAV of 0.01, 0.40, and 0.52 ng/mL/y or less, respectively. The PSAV correlated with age, initial PSA level, and interval between measurements. The percentage of men with a PSAV greater than 0.75 ng/mL/y was 0.61% (151 of 24 869) and was 0.51% (92 of 17 985) for those with an initial PSA level of less than 1.0 ng/mL, 0.86% (50 of 5807) for those with a PSA level of 1.1-2.0 ng/mL, and 0.84% (9 of 1077) for those with an initial PSA level of 2.1-4.0 ng/mL. CONCLUSIONS In healthy Korean men with an initial PSA level of 4.0 ng/mL or less, most will have a PSAV of less than 0.75 ng/mL/y. Thus, traditional PSAV cutoff values are not applicable in this population. We propose that a lower PSAV cutoff value should be used to indicate biopsy. Additional large-scale prospective studies, including biopsy data, are required to assess the cutoff value of PSAV for healthy Korean men with a PSA level of 4.0 ng/mL or less.


Yonsei Medical Journal | 2008

A multi-institutional study on histopathological characteristics of surgically treated renal tumors: The importance of tumor size

Sun Il Kim; Y.D. Choi; Se Joong Kim; Byung Ha Chung; Do Hwan Seong; Chun Il Kim; Sang Hyeon Cheon; Jin Seon Cho; Yun Seob Song; Young Sig Kim; In Rae Cho; Dong Hyeon Lee; Ki Hak Song; Hong Sup Kim; Joong Shik Lee; Won Jae Yang; Sung Joon Hong

Purpose The incidence of accidentally detected small renal tumors is increasing throughout the world. In this multi-institutional study performed in Korea, histopathological characteristics of contemporarily surgically removed renal tumors were reviewed with emphasis on tumor size. Materials and Methods Between January 1995 and May 2005, 1,702 patients with a mean age of 55 years underwent surgical treatment at 14 training hospitals in Korea for radiologically suspected malignant renal tumors. Clinicopathological factors and patient survival were analyzed. Results Of the 1,702 tumors, 91.7% were malignant and 8.3% were benign. The percentage of benign tumors was significantly greater among those ≤ 4 cm (13.2%) than those > 4 cm (4.5%) (p < 0.001). Among renal cell carcinoma patients, the percentage of tumors ≤ classed as stage ≥ T3 was significantly less among tumors 4 cm (5.2%) than those > 4 cm (26.8%) (p < 0.001). The percentage of tumors classed as Fuhrmans nuclear grades ≥ 3 was also significantly less among tumors ≤ 4 cm (27.3%) than tumors > 4 cm (50.9%) (p < 0.001). The 5-year cancer-specific survival rate was 82.7%, and T stage (p < 0.001), N stage (p < 0.001), M stage (p = 0.025), and Fuhrmans nuclear (p < 0.001) grade were the only independent predictors of cancer-specific survival. Conclusion In renal tumors, small tumor size is prognostic for favorable postsurgical histopathologies such as benign tumors, low T stages, and low Fuhrmans nuclear grades. Our observations are expected to facilitate urologists to adopt function-preserving approach in the planning of surgery for small renal tumors with favorable predicted outcomes.


Yonsei Medical Journal | 2013

Role of Prostate Volume in the Early Detection of Prostate Cancer in a Cohort with Slowly Increasing Prostate Specific Antigen

Young Min Kim; Sungchan Park; June Kim; Seonghun Park; Ji Ho Lee; Dong Soo Ryu; Seong Hoon Choi; Sang Hyeon Cheon

Purpose To investigate the relationship between prostate volume and the increased risk for being diagnosed with prostate cancer (PCa) in men with slowly increasing prostate specific antigen (PSA). Materials and Methods A cohort of 1035 men who visited our hospitals health promotion center and were checked for serum PSA levels more than two times between January 2001 and November 2011 were included. Among them, 116 patients had a change in PSA levels from less than 4 ng/mL to more than 4 ng/mL and underwent transrectal ultrasound guided prostate biopsy. Median age was 55.9 years and 26 (22.4%) had PCa. We compared the initial PSA level, the last PSA level, age, prostate volume, PSA density (PSAD), PSA velocity, and follow-up period between men with and without PCa. The mean follow-up period was 83.7 months. Results Significant predictive factors for the detection of prostate cancer identified by univariate analysis were prostate volume, follow-up period and PSAD. In the multivariate analysis, prostate volume (p<0.001, odds ratio: 0.890) was the most significant factor for the detection of prostate cancer. In the receiver operator characteristic curve of prostate volume, area under curve was 0.724. At the cut-off value of 28.8 mL for prostate volume, the sensitivity and specificity were 61.1% and 73.1% respectively. Conclusion In men with PSA values more than 4 ng/mL during the follow-up period, a small prostate volume was the most important factor in early detection of prostate cancer.


Korean Journal of Urology | 2011

Solitary Penile Neurofibroma with Erectile Dysfunction

Young Hwan Ji; Sang Hyeon Cheon; Joong Ho Lee; Kyung Hyun Moon; Young Min Kim; Seonghun Park; Sungchan Park

Neurofibromas of the penis, although very rare, are often associated with neurofibromatosis type 1. Primary solitary neurofibromas of the penis are extremely rare. We describe a 37-year-old man with a solitary neurofibroma in the dorsum of the penis. The patient reported difficulty with sexual intercourse owing to a penile mass and erectile dysfunction. After surgical excision of the neurofibroma, he had no pain and a normal sensation of the penile glans, and his erectile dysfunction improved. At the present time, 26 months after surgery, there has been no evidence of tumor recurrence.

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Won Jae Yang

Soonchunhyang University

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Yun Seob Song

Soonchunhyang University

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