Koo Han Yoo

Treatment of Infected Urachal Cysts

The urachus is a fibrous cord that arises from the anterior bladder wall and extends cranially to the umbilicus. Traditionally, infection has been treated using a two-stage procedure that includes an initial incision and drainage which is then followed by elective excision. More recently, it has been suggested that a single-stage excision with improved antibiotics is a safe option. Thus, we intended to compare the effects of the two-stage procedure and the single-stage excision. We performed a retrospective review on nine patients treated between May 1990 and September 2005. The methods used in diagnosis were ultrasonography, computed tomography (CT), magnetic resonance imaging (MRI), and cystoscopy. The study group was comprised of three males and six females with a mean age of 28.2 years (with a range from three to 71 years). Symptoms consisted of abdominal pain, abdominal mass, fever, and dysuria. The primary incision and drainage followed by a urachal remnant excision with a bladder cuff excision (two-stage procedure) was performed in four patients. The mean postoperative hospitalization lasted 5.8 days (with a range of three to seven days), and there were no reported complications. A primary excision of the infected urachal cyst and bladder cuff (single-stage excision) was performed in the other five patients. These patients had a mean postoperative hospitalization time of 9.2 days (with a range of four to 15 days), and complications included an enterocutaneous fistula, which required additional operative treatment. The best method of treating an infected urachal cyst remains a matter of debate. However, based on our results, the two-stage procedure is associated with a shorter hospital stay and no complications. Thus, when infection is extensive and severe, we suggest that the two-stage procedure offers a more effective treatment option.

Comparison of urodynamics between ischemic and hemorrhagic stroke patients; Can we suggest the category of urinary dysfunction in patients with cerebrovascular accident according to type of stroke?

The aim of this study is to compare the urodynamic parameters in ischemic and hemorrhagic stroke patients with bladder dysfunction.

Association of IL10, IL10RA, and IL10RB Polymorphisms with Benign Prostate Hyperplasia in Korean Population

Cytokines such as interleukin 10 (IL10) may play an important role in the process of inflammation. The aim of this study was to analyze the association between IL10, IL10RA and IL10RB single nucleotide polymorphisms (SNPs), and benign prostate hyperplasia (BPH) in Korean population. All patients with BPH were divided into two groups according to international porostate symptom score (IPSS), prostate specific antigen (PSA) level, Qmax, and prostate volume. We selected two IL10 SNPs (rs1518111 and rs1554286), three IL10RA SNPs (rs2256111, rs4252243, and rs2228054), and two IL10RB SNPs (rs999788 and rs2834167). Genotypes of seven SNPs were determined through direct sequencing. The G/G genotype of IL10RB polymorphism (rs2834167) was associated with a high PSA level compared with the A/G + A/A genotypes (P = 0.009). Of IL10 SNP, the A/A genotype of rs1518111 and T/T genotype of rs1554286 were associated with small prostate volume, respectively (P = 0.011, P = 0.014). Moreover, the T/T genotype of IL10RB polymorphism (rs999788) was associated with high prostatic volume compared with the T/C + C/C genotypes (P = 0.033). The linkage disequilibrium (LD) blocks were formed in IL10 and IL10RA. However, haplotypes in the LD block were not associated with BPH. It is concluded that there is a strong association between the IL10 and IL10RB SNPs, and BPH in Korean population.

Epigenetic inactivation of HOXA5 and MSH2 gene in clear cell renal cell carcinoma

The high‐throughput method using microarray is an easy and fast way to analyze the methylation status of hundreds of preselected genes and to screen them for signatures in methylation. The aim of our study is to detect hypermethylated genes and to analyze the association between methylation status and clinicopathological parameters of clear cell renal cell carcinoma. The genetic substrate included 62 cancer tissues and 62 matched adjacent normal kidney tissues. We adapted the GoldenGate genotyping assay to determine the methylation state of 1505 specific CpG sites in 807 genes. We identified two genes (HOXA5 and MSH2) with β‐value differences of more than 0.3 between cancer and normal tissues. The high methylation group in HOXA5 had high Fuhrmans nuclear grade (P= 0.041). Other data in HOXA5 and MSH2 were not significant with methylation status (P > 0.05). Survival curve of the high methylation group in HOXA5 was slightly lower than that of the low methylation group. However, the statistical significances of overall survival in HOXA5 and MSH2 were low (P > 0.05). We report the hypermethylation of two genes in clear cell renal cell carcinoma. The data we obtained could provide the basis for a diagnostic test pathological assessment, or prognosis in clear cell renal cell carcinoma.

Magnetotransport, magneto-optical, and electronic subband studies in InxGa1−xAs/InyAl1−xAs modulation-doped strained double quantum wells

Magnetotransport and magneto-optical measurements on InxGa1−xAs/InyAl1−yAs modulation-doped strained double quantum wells with a 100 A In0.8Ga0.2As well and a 100 A In0.53Ga0.47As quantum wells separated by a 35 A In0.25Ga0.75As potential barrier were carried out to investigate the electrical and the optical properties of the electron gas in the quantum wells. The Shubnikov-de Haas measurements at 1.5 K demonstrated clearly the occupation of three subbands in the quantum wells by a two-dimensional electron gas. The electron effective masses determined from the slopes of the cyclotron resonance peak energies as a function of the magnetic field were 0.06171 and 0.05228me. The electronic subband energies, the subband energy wavefunctions, and the Fermi energy in the quantum wells were self-consistently calculated a transfer matrix method taking into account the exchange-correlation effect, the strain effect, and the nonparabolicity effect, and the results of the cyclotron resonance measurements qualitatively...

Effect of dominant hemispheric stroke on detrusor function in patients with lower urinary tract symptoms.

Objectives:  To determine the effect of unilateral hemispheric lesion on voiding dysfunction by comparing urodynamic parameters in dominant, non‐dominant and bilateral hemispheric stroke patients.

A Rare Case of Upper Ureter Rupture: Ureteral Perforation Caused by Urinary Retention

Perforation of the ureter is a rare condition that causes a series of problems including retroperitoneal urinoma, urosepsis, abscess formation, infection, and subsequent renal impairment. There are causative factors that induce ureteric rupture, including malignancy, urinary calculi, idiopathic retroperitoneal fibrosis, recent iatrogenic manipulation, external trauma, degenerative kidney conditions, urography with external compression, and spontaneous causes. We report a rare case of ureteric rupture caused by urinary retention. The patient was treated with temporary percutaneous drainage and antibiotics. The present case illustrates that urinary retention can induce not only bladder rupture, but also ureteric rupture. It is thus of paramount importance to effectively manage patients with voiding problems.

How many cases are necessary to develop competence for laparoscopic radical nephrectomy

PURPOSE We evaluated the number of cases necessary to develop competence for performing laparoscopic radical nephrectomy (LRN) by chronologically analyzing the results of 150 cases. PATIENTS AND METHODS 150 patients were included in this study, each of whom had had pure transperitoneal LRNs between March 2003 and February 2008 performed by three surgeons who were all novices in laparoscopic surgery. Each surgeon performed 50 LRNs. These were divided into 10 groups chronologically, with five cases in each group (individual-group). Subsequently, we combined the data of the three surgeons, with 15 cases assigned to each group (combined-group). We identified the groups that demonstrated a statistically significant difference in operative time, compared with the most recent group. Based on this finding, we divided the cases into two groups: The novice group and the competent group. The complication rate, transfusion rate, and estimated blood loss were then compared between the two groups. RESULTS The total average operative time was 187.6 +/- 46.56 minutes; from group 4 onward, there was no significant decrease in the operative time. Therefore, groups 1 to 3 were defined as the novice groups, and groups 4 to 10 as the competent groups. Incidence of intraoperative complications was six (13.3%) in the novice group and nine (8.6%) in the competent group. There were 14 cases with postoperative complications--4 (8.9%) in the novice group and 10 (9.5%) in the competent group. There were significant differences in the estimated blood loss and transfusion rate between the novice and competent groups (236.4 +/- 41.85 mL vs 191.5 +/- 21.9 mL, 17.8% vs 4.8%, respectively). CONCLUSIONS Our results suggest that 15 cases are needed for a novice surgeon to achieve competence in LRN. Surgical outcomes and morbidity can be improved once this learning curve has been overcome.

Simple Renal Cyst Sclerotherapy with Acetic Acid: Our 10-Year Experience

BACKGROUND AND PURPOSE The combination of percutaneous aspiration and sclerotherapy is an effective method for managing benign renal cysts. Many substances have been used as sclerosing agents. Here, we report the long-term outcome after simple renal cyst sclerotherapy with acetic acid. MATERIALS AND METHODS We retrospectively reviewed medical records and identified 60 cases of renal cysts that were managed with percutaneous sclerotherapy from June 1998 to December 2007. All patients were followed up with ultrasonography. We divided the treatment results into three groups: Complete regression (<10%), partial regression (11%-50%), and no response (>51%). RESULTS The mean volume of the renal cysts on presclerotherapy images was 244 mL (range 12-1216 mL), the mean volume of the aspirate was 233 mL (range 10-1450 mL), and the mean volume of acetic acid administered was 34.6 mL (range 4-100 mL). The median follow-up period was 10 months (range 3-84 months); 46 cases exhibited complete regression (76.7%); 12, partial regression (20.0%); and 2, no response (3.3%). The complications were local pain (nine cases, 15.0%) and nausea and/or vomiting (three cases, 5.0%). CONCLUSIONS The results reveal that acetic acid as a sclerosing agent exhibits a high long-term success rate even at a low dose and produces few complications during the procedure. Thus, we suggest that sclerotherapy with acetic acid offers a more effective management option.

Room‐temperature magnetoabsorption in HgTe/Hg0.15Cd0.85Te superlattices

We report a study of magnetoabsorption in three HgTe/Hg0.15Cd0.85Te superlattices at room temperature. Three absorption peaks were observed and analyzed with our transfer‐matrix method. With our initial choice of input parameters, we obtain a reasonable fit with a valence‐band offset of 730 or 850 meV, depending on the sample. We discuss the effects of changes in some of the important input parameters on the superlattice Landau levels.