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Dive into the research topics where Chang Hee Hong is active.

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Featured researches published by Chang Hee Hong.


BJUI | 2001

Comparison of single and multiple sessions of percutaneous sclerotherapy for simple renal cyst: PERCUTANEOUS SCLEROTHERAPY

Byung Ha Chung; Jang Hwan Kim; Chang Hee Hong; Seung Choul Yang; M.S. Lee

Objective To compare the results of single and repeated percutaneous sclerotherapy in patients with simple renal cysts.


Toxicology Letters | 2008

Enhanced TGF-β1 is involved in 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induced oxidative stress in C57BL/6 mouse testis

Mei Hua Jin; Chang Hee Hong; Hye Young Lee; Hyo Jin Kang; Sang Won Han

2,3,7,8-Tedtrachlorodibenzo-p-dioxin (TCDD) is one of the most toxic endocrine disruptors and has been reported to induce oxidative stress in the reproductive organs. However, the mechanism by which TCDD induces oxidative stress is unclear. The aim of this study is to examine the role of the general cytokine, TGF-beta1, in TCDD-induced oxidative stress in the male reproductive system. To examine the effect of TCDD on antioxidant enzyme activity, we administered TCDD orally to C57BL/6 mice at 1 microgkg/day for 4 days. Using Smad2-siRNA, we examined the involvement of Smad and non-Smad pathways in TCDD-induced oxidative stress. We also measured the mRNA levels of typical antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase) and analyzed the activation of TGF-beta1, and the downstream signals, Smad2, Smad4, transcription factors (c-Jun, ATF3), and three major MAPKs (JNK, ERK, p38). After TCDD treatment, the mRNA levels of antioxidant enzymes (superoxide dismutase, catalase, glutathione peroxidase) were significantly decreased. In addition, TGF-beta1 activity increased and the receptor-activated protein, Smad2, was activated while Smad4 was not. The levels of major transcription factors, c-Jun and ATF3, and the regulator of these transcription factors, MAPK, were also increased by TCDD administration. The mRNA levels of the 3 antioxidant enzymes in the Smad2-siRNA and TCDD co-treated group were higher than that of the TCDD-only treated group but still decreased when compared to control. C-Jun and ATF3 levels were also increased in Smad2-siRNA and TCDD co-treated testes compared to control. However, the levels of c-Jun and ATF3 were lower than those in the group treated with TCDD only. Of the three MAPKs which showed increase in expression after TCDD treatment, p38 was the only one that showed a decrease with Smad2 inhibition, while both ERK and JNK expression were unaffected. In conclusion, we found that the activated TGF-beta1-Smad pathway is involved in TCDD-induced oxidative stress. Furthermore, the effects of TCDD on the testes are caused by the coordinated action of both Smad and non-Smad pathways.


Environmental Toxicology | 2010

Toxic effects of lactational exposure to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on development of male reproductive system: involvement of antioxidants, oxidants, and p53 protein.

Mei Hua Jin; Chang Hee Hong; Hye Young Lee; Hyo Jin Kang; Sang Won Han

2,3,7,8‐Tetrachlorodibenzo‐p‐dioxin (TCDD) is a potent endocrine disruptor compound and induces multiple organ dysfunctions. The effect of TCDD exposure both in adults and in utero has been well established. However, little is known about the effects of TCDD acquired through mothers milk on the development of the male reproductive system. The aim of this study was to investigate the effects and mechanisms of TCDD from lactational exposure. TCDD (1 μg/kg) was administered to C57BL/6 mouse mothers for 4 days from the day of delivery. On postnatal day 30 (PND 30) and postnatal day 60 (PND 60), body weight, body length, and anogenital distance (AGD) of male offspring were measured. The weights of the testes and epididymides were also measured. Epididymides were used for sperm counts, and testes were used to measure the activity of antioxidant enzymes (SOD, CAT, GPX, GR), the parameters of oxidative stress (hydrogen peroxide, MDA), and testosterone. In addition, expression of p53 and the proapoptotic protein, Bax, were analyzed by Western blot. TCDD exposure decreased body weight, body length, and AGD in both PND 30 and PND 60 groups compared with the control group. The activity of all antioxidant enzymes at PND 60 was decreased after TCDD treatment. TCDD treatment decreased testicular testosterone levels in both the PND 30 and PND 60 groups. The expression of p53 and Bax were also upregulated by TCDD and did not return to normal levels by PND 60. These data suggest that TCDD affects development of male offspring when the mother is exposed to TCDD during lactation. In addition, oxidative stress is a major mediator of TCDD‐induced adverse effects, and p53 may play an important role in this mechanism.


Urology | 2011

Initial Experience With Laparoendoscopic Single-site Nephrectomy and Nephroureterectomy in Children

Won Sik Ham; Young Jae Im; Hyun Jin Jung; Chang Hee Hong; Woong Kyu Han; Sang Won Han

OBJECTIVES To assess the clinical utility and safety of laparoendoscopic single-site surgery (LESS) nephrectomy and nephroureterectomy in children by analyzing 6 consecutive cases performed by a single surgeon. METHODS Since March 2009, we have been performing LESS nephrectomy and nephroureterectomy in children. The indications have been recurrent pyelonephritis related to vesicoureteral reflux with an atrophic kidney and continuous urinary incontinence related to an ectopic ureter. A homemade port was placed through an umbilical incision, and the laparoscopic transperitoneal nephrectomy procedures were performed using various combinations of standard and articulating laparoscopic instruments. The patients undergoing a LESS procedure were evaluated prospectively, and the data were collected during and after surgery. RESULTS A total of 6 procedures, including nephrectomy (4 cases) and nephroureterectomy (2 cases), were completed without intraoperative or postoperative complications. The median operation time was 112 minutes (range 90-148), and the median blood loss was 0 mL (range 0-50). All patients received only oral ibuprofen syrup for pain control and were discharged on postoperative day 2. As the surgeon gained experience, the length of the umbilical incision was decreased from 2.0 to 1.0 cm. CONCLUSIONS Pediatric LESS nephrectomy and nephroureterectomy can be performed safely with a very small incision. LESS performed by an experienced laparoscopic surgeon has the potential to become an alternative first-line therapy for ablative procedures in children.


The Journal of Urology | 2001

DOES EVERY PATIENT WITH URETEROPELVIC JUNCTION OBSTRUCTION NEED VOIDING CYSTOURETHROGRAPHY

Young Sig Kim; Sung Hoon Do; Chang Hee Hong; Myung Joon Kim; Seung Kang Choi; Sang Won Han

PURPOSE Voiding cystourethrography is routinely recommended to detect vesicoureteral reflux in children with ureteropelvic junction obstruction. Vesicouretral reflux coexisting with primary ureteropelvic junction obstruction is usually of low grade and resolves spontaneously after pyeloplasty, whereas pseudo ureteropelvic junction obstruction and obstruction secondary to high grade reflux usually present with a dilated ureter that is easily detected on real-time ultrasonography. We assessed the role of voiding cystourethrography in children with ureteropelvic junction obstruction by retrospectively evaluating the incidence and natural history of coexisting vesicourethral reflux. MATERIALS AND METHODS We reviewed the records of 106 children younger than 15 years who underwent pyeloplasty for ureteropelvic junction obstruction at our hospital between January 1990 and December 1998. A patient who had initially undergone antireflux surgery later underwent pyeloplasty for newly developed secondary obstruction was not included in the analysis. The diagnosis of ureteropelvic junction obstruction was based on ultrasonography and diuretic renography. Preoperative voiding cystourethrography was performed in all patients to detect vesicourethral reflux. We categorized reflux as low grade if the ureters were not dilated and as high grade if the ureters were dilated and tortuous. RESULTS There were 89 boys and 17 girls who underwent 115 pyeloplasties, including 9 who underwent bilateral pyeloplasty. Mean patient age at surgery was 27.4 months (63 infants, 6 between 1 and 2 years old, and 37 older than 2 years). Of these 106 patients 85 had unilateral (left side 64, right side 21) and 21 had bilateral ureteropelvic junction obstruction. Vesicourethral reflux was documented in 19 ureters of 12 children. Of the 85 cases of unilateral ureteropelvic junction obstructions 10 had vesicourethral reflux, which was bilateral 6, ipsilateral in 2 and contralateral in 2. Of the 21 cases of bilateral obstructions 2 had reflux, which was bilateral in 1 and was unilateral in 1. Reflux was low grade reflux in 6 and high grade in 6 cases. All low grade reflux disappeared spontaneously at an average period of 4.2 months (range 2 to 10) after pyeloplasty. All 6 patients with high grade reflux subsequently underwent antireflux surgery because of breakthrough urinary tract infection in 2 and persistent in 4 at an average of 36 months (range 3 to 112) after pyeloplasty. All high grade reflux coexisting with ureteropelvic junction obstruction was easily detected on real-time ultrasonography. CONCLUSIONS Low grade reflux coexisting with ureteropelvic junction obstruction spontaneously disappeared after pyeloplasty, and all high grade reflux coexisting with obstruction was easily detected on ultrasonography using real-time mode. Therefore, we believe that indication for voiding cystourethrography in children with ureteropelvic junction obstruction should be limited to those with dilated ureters on ultrasonography.


Journal of Laparoendoscopic & Advanced Surgical Techniques | 2011

Transvesicoscopic Ureteral Reimplantation in Children with Bilateral Vesicoureteral Reflux: Surgical Technique and Results

Mun Su Chung; Sang Won Han; Hyun Jin Jung; Young Jae Im; Hyun Ho Han; Joon Chae Na; Chang Hee Hong

OBJECTIVES To report our initial experience with transvesicoscopic cross-trigonal ureteral reimplantation (TVUR), describing stepwise the surgical procedure and determining critical aspects of this surgery in the actual surgical field. SUBJECTS AND METHODS Between September 2008 and April 2010, 48 patients with bilateral vesicoureteral reflux (VUR) underwent TVUR. To identify the critical aspects affecting the surgical difficulty, we divided our TVUR procedure into four steps: TVUR set-up, mobilization of ureters, creation of submucosal tunnels, and ureterovesical anastomosis. To evaluate the evolution of our TVUR, we analyzed changes in the operative time and complications versus increase in surgeon experience (dividing our cases into three groups: the first third, the second third, and the last third). Changes in operative time for all four steps of TVUR were analyzed separately, as well as change in overall operative time. RESULTS Of a total of 48 cases, 45 patients underwent TVUR successfully except for 3 cases of open conversion. Among the 45 cases, the mean overall operative time was 155.6 min. In 1 patient, proximal migration of the ureteral catheter occurred. No other perioperative complications were observed. The mean postoperative hospital stay was 1.6 days. The VUR resolution rate was 96.4%. Upon analysis of our results by step, Step 4 (ureterovesical anastomosis) required the largest portion of the overall operative time in most cases. During the early period of our TVUR, we encountered several technical difficulties. However, the operative times for all four steps were stabilized with increasing number of cases, without deteriorating surgical outcomes. CONCLUSIONS Our report demonstrates that TVUR might potentially be a safe and effective alternative to open ureteral reimplantation in children with VUR, with a shorter learning curve than expected.


Urology | 2010

Pediatric laparoendoscopic single-site partial nephrectomy: initial report.

Hwang Gyun Jeon; Dong Suk Kim; Ha Bum Jeoung; Sang Won Han; Chang Hee Hong; Young Jae Im; Young Taek Oh; Myung Joon Kim; Woong Kyu Han

OBJECTIVES We present a case of transumbilical laparoendoscopic single-site surgery (LESS) for partial nephrectomy in a child. METHODS On May 22, 2009, we performed LESS partial nephrectomy on a 7-year-old girl with a 3.5-cm renal mass. The surgery was performed using a homemade single-port device inserted through a single 3-cm umbilical incision. LESS partial nephrectomy was performed with hilar clamping and suturing of the renal defect. RESULTS The duration of the operation was 210 minutes, and the warm ischemic time was 42 minutes. The suturing required 35 minutes, and the estimated blood loss was 10 mL. Histopathological analysis revealed a 3.5-cm metanephric adenoma with a clean surgical margin. The patient was discharged without intraoperative or postoperative complications. On follow-up, Doppler ultrasound sonography showed the kidney was normal in appearance, size, and echogenicity. Split renal function was calculated to be 47.5% for the left kidney upon dimercaptosuccinic acid renal scintigraphy. CONCLUSIONS LESS partial nephrectomy was safe and feasible for removal of a renal mass in a child. Additional development of applicable instruments and refinement of the suturing technique are needed.


The Journal of Urology | 2010

Increased Urinary Nerve Growth Factor as a Predictor of Persistent Detrusor Overactivity After Bladder Outlet Obstruction Relief in a Rat Model

Seung Ryeol Lee; Chang Hee Hong; Young Deuk Choi; Jang Hwan Kim

PURPOSE We evaluated urinary nerve growth factor as a predictive factor for persistent detrusor overactivity after bladder outlet obstruction relief in a rat model. MATERIALS AND METHODS A total of 50 female Sprague-Dawley(R) rats were divided into 2 groups, including 10 sham operated controls and 40 with bladder outlet obstruction. Obstruction was induced by partial urethral ligation and relieved by ligation removal after 3 weeks. Voided urine was collected before bladder outlet obstruction at time 1, 3 weeks after obstruction onset at time 2 and 3 weeks after obstruction relief at time 3. Cystometry was done in awake rats at times 2 and 3. Bladder tissue was harvested at time 3. Urinary and bladder tissue nerve growth factor was measured by enzyme-linked immunosorbent assay with results adjusted based on creatinine concentration. RESULTS In 16 rats in which detrusor overactivity disappeared after bladder outlet obstruction relief (group 1) urinary nerve growth factor/creatinine significantly increased from time 1 to 2 and significantly decreased from time 2 to 3 (p = 0.001 and 0.003, respectively). In 8 rats with persistent detrusor overactivity despite obstruction removal (group 2) urinary nerve growth factor/creatinine significantly increased from time 1 to 2 but did not change from time 2 to 3 (p = 0.012 and 0.123, respectively). These rats with persistent detrusor overactivity also had significantly higher urinary nerve growth factor/creatinine at time 1 than controls and group 1 (p = 0.015 and 0.005, respectively). CONCLUSIONS Changes in urinary nerve growth factor may reflect detrusor overactivity, as diagnosed on 2 consecutive cystometries. Increased urinary nerve growth factor before bladder outlet obstruction may predict persistent detrusor overactivity after obstruction relief.


Yonsei Medical Journal | 2008

In utero exposure to 2,3,7,8-Tetrachlorodibenzo-p-Dioxin affects the development of reproductive system in mouse.

Mei Hua Jin; Hae Kyung Ko; Chang Hee Hong; Sang Won Han

Purpose Exposure of male reproductive organs to 2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD) has been reported to cause developmental changes. In this study, we evaluated the effects of in utero TCDD exposure on male reproductive development. Materials and Methods Pregnant C57BL/6 mice were administered a single intraperitoneal injection of TCDD (1 µg/kg) on gestation day (GD) 15. The offspring were examined in the immature stage on postnatal day (PND) 30 and in the mature stage on PND 60. The testes were examined for histological changes, androgen receptor (AR), proliferating cell nuclear antigen (PCNA) and apoptosis following the measurement of morphological changes. Results Anogenital distance (AGD) and testis weights were reduced by TCDD exposure both on PND 30 and PND 60 while body weights and length of male offspring were not affected by TCDD. The regular sperm developmental stage was impaired with TCDD treatment on PND 30. However, no difference was found between the control group and TCDD groups on PND 60. Simultaneously, the expression of AR was also reduced on PND 30, while it was increased on PND 60 compared with the control group. The expression of PCNA was decreased whereas apoptosis was not affected by TCDD both on PND 30 and PND 60. Conclusion These results suggest that in utero exposure to TCDD influences the development of testes by inhibiting the expression of AR and PCNA. Moreover, the adverse effects of TCDD on male offspring reduced over time.


Urology | 2011

Single-surgeon Experience With Transvesicoscopic Ureteral Reimplantation in Children With Vesicoureteral Reflux

Chang Hee Hong; Jang Hwan Kim; Hyun Jin Jung; Young Jae Im; Sang Won Han

OBJECTIVES To review our initial experience with transvesicoscopic ureteral reimplantation (TVUR) in children with vesicoureteral reflux and to evaluate the learning curve for the feasibility and reproducibility of TVUR. METHODS TVUR was performed in 28 consecutive patients with a mean age of 6.0 years. Cohens classic technique was reproduced using a laparoscopic technique with two 3-mm working ports and a 5-mm camera port. RESULTS TVUR was successfully completed in 26 patients. In 2 patients, TVUR was converted to open intravesical reimplantation. The postoperative vesicoureteral reflux resolution rate was 94.6% (35 of 37 ureters). The mean operative time for TVUR was 166 minutes for unilateral reimplantation and 189 minutes for bilateral reimplantation. When the operation times of the first 13 and the last 13 patients were compared, the mean operative time had decreased significantly for the last 13 patients compared to that for the first 13 patients (140 vs 220 minutes). The mean postoperative hospital stay was also significantly shorter for the last 13 patients than for the first 13 patients (1.08 vs 1.69 days). CONCLUSIONS TVUR is currently performed at only at a few centers because of the technical difficulties and the potentially steep learning curve. However, our results have indicated rapid improvement in the operative time within a short period, suggesting a shorter learning curve for TVUR than expected. TVUR is a reproducible procedure and is a reasonable option for the treatment of vesicoureteral reflux.

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Myung Joon Kim

Boston Children's Hospital

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