Stone Yang
Mackay Memorial Hospital
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Featured researches published by Stone Yang.
Urologia Internationalis | 2004
Stone Yang; Wen-Chou Lin; Huang-Kuang Chang; Jong-Ming Hsu; Wun-Rong Lin; Yung-Chiong Chow; Wei-Kung Tsai; Te-An Lee; King-Yik Lo; Ko Chow; Marcelo Chen
Introduction: This randomized prospective study was conducted to compare the efficacy and safety of the Gyrus Plasmasect loop bipolar transurethral resection of prostate (TURP) and conventional monopolar TURP in the treatment of benign prostatic hyperplasia (BPH). Materials and Methods: A total of 117 men were enrolled in this study. Fifty-eight patients underwent Gyrus Plasmasect TURP and 59 patients underwent monopolar TURP. They were followed up for 3 months after surgery. Results: Significant improvements were seen postoperatively in both the Gyrus and monopolar groups in terms of prostatic volume, International Prostate Symptom Score, quality of life score, peak flow rate, and post-void residual urine volume. However, the degree of improvement was not statistically different between the 2 groups. Significantly less blood loss, shorter postoperative catheterization time and length of hospital stay were seen in the Gyrus group. Conclusions: Gyrus Plasmasect TURP yielded comparable results to monopolar TURP; however, this is only a preliminary study and follow-up is necessary to assess its long-term efficacy.
Clinical Cancer Research | 2007
Yu Chuen Huang; Cheng Ming Lee; Marcelo Chen; Ming Yi Chung; Yen Chang; William J.S. Huang; Donald Ming-Tak Ho; Chin Chen Pan; Tony T. Wu; Stone Yang; Ming-Wei Lin; Jer Tsong Hsieh; Yi-Ming Arthur Chen
Purpose: Glycine N-methyltransferase (GNMT) affects genetic stability by regulating DNA methylation and interacting with environmental carcinogens. In a previous study, we showed that GNMT acts as a susceptibility gene for hepatocellular carcinoma. Here, we report on our efforts to characterize the haplotypes, loss of heterozygosity (LOH), and expression levels of the GNMT in prostate cancer. Experimental Design: Peripheral blood mononuclear cell DNA collected from 326 prostate cancer patients and 327 age-matched controls was used to determine GNMT haplotypes. Luciferase reporter constructs were used to compare the promoter activity of different GNMT haplotypes. GNMT LOH rates in tumorous specimens were investigated via a comparison with peripheral blood mononuclear cell genotypes. Immunohistochemical staining was used to analyze GNMT expression in tissue specimens collected from 5 normal individuals, 33 benign prostatic hyperplasia patients, and 45 prostate cancer patients. Results: Three major GNMT haplotypes were identified in 92% of the participants: A, 16GAs/DEL/C (58%); B, 10GAs/INS/C (19.9%); and C, 10GAs/INS/T (14.5%). Haplotype C carriers had significantly lower risk for prostate cancer compared with individuals with haplotype A (odds ratio, 0.68; 95% confidence interval, 0.48-0.95). Results from a phenotypic analysis showed that haplotype C exhibited the highest promoter activity (P < 0.05, ANOVA test). In addition, 36.4% (8 of 22) of the prostatic tumor tissues had LOH of the GNMT gene. Immunohistochemical staining results showed abundant GNMT expression in normal prostatic and benign prostatic hyperplasia tissues, whereas it was diminished in 82.2% (37 of 45) of the prostate cancer tissues. Conclusions: Our findings suggest that GNMT is a tumor susceptibility gene for prostate cancer.
Urologia Internationalis | 2005
Eugene Lin; Stone Yang; Allen W. Chiu; Yung-Chiong Chow; Marcelo Chen; Wen-Chou Lin; Hung-Kuang Chang; Jong-Ming Hsu; King-Yik Lo; Hsi-Hsien Hsu
Objectives: Fournier’s gangrene (FG) is a rare but life-threatening disease. Although antibiotics and aggressive debridement have been broadly accepted as the standard treatment, the mortality rate remains high. We conducted a retrospective study to analyze the outcome and identify the risk factors and prognostic indicators. Methods: We retrospectively reviewed the medical records of 25 patients diagnosed with FG between July 1993 and August 2003. Data collected included age, predisposing factors, treatment modalities, length of hospital stay, surgical debridement times, and outcome. The FG severity index was used to predict outcome. Univariate analysis of the different prognostic factors was performed using t test and Fisher’s exact probability test. Results: All patients were male, 60% were diabetic, and the mean age was 55.8 years. The mean hospital stay was 20 days and the mortality rate was 32%. The mean age of 53.8 ± 18.3 (SD) years in the survival group (n = 17) was significantly lower than the 59.9 ± 10.2 years (n = 8) of the non-survival group (p < 0.05). Non-survival group patientshad lower serum hematocrit (mean 28.9, p = 0.019) and albumin (mean 1.93, p = 0.024) levels. In our series, the mean FG severity index for survivors was 4.41 ± 2.45 (range 2–9) compared to 12.75 ± 2.82 (range 9–18) for those who died (t test, p < 0.0001). Conclusion: The survival rate of younger patients with FG was higher. We agree that a FG severity index cutoff value of 9 is an excellent predictor of outcome.
The Prostate | 2009
Marcelo Chen; Yu-Chuen Huang; Stone Yang; Jong-Ming Hsu; Yen-Hwa Chang; William J.S. Huang; Yi-Ming Arthur Chen
Recently, independent genome‐wide scans have found multiple genetic variants at 8q24 to be associated with prostate cancer risk. This study was performed to determine whether two of the variants more strongly associated with prostate cancer risk in European and American populations, specifically rs16901979 and rs6983561, were also associated with prostate cancer risk in Taiwanese men.
Urologia Internationalis | 2005
Stone Yang; Yi-Hsiu Huang; Chih-Ming Ou Yang; Steven K. Huann; Marcelo Chen; Wun-Rong Lin; Jen-Tai Lin; King-Yik Lo; Allen W. Chiu
Introduction: Laparoscopic-assisted radical cystectomy with continent ileal reservoir reconstruction is a challenging procedure. We report our experience learned from a hand-assisted laparoscopic technique in our transition to a pure laparoscopic approach. Materials and Methods: Eighteen consecutive patients underwent laparoscopic-assisted radical cystectomy with continent ileal reservoir. Hand-assisted laparoscopy was used for the first 11 patients and pure laparoscopy was performed for the subsequent 7 patients in radical cystectomy. Continent ileal reservoir reconstruction was performed extracorporeally via the hand port wound or trocar extension wound. Surgical outcome was analyzed in a retrospective review of the medical records. Results: In the hand-assisted and pure laparoscopic groups, the mean operative time for cystectomy was 2.5 and 2.3 h, for continent ileal reservoir reconstruction it was 4.0 and 3.7 h, and for bilateral lymph node dissection it was 0.8 and 0.6 h, respectively. Mean intraoperative blood loss was 286 ml for the hand-assisted and 179 ml for the pure laparoscopic group. There were no major intraoperative complications nor need for conversion in any of the procedures. Bowel movement was regained in a mean of 3 days and the mean length of postoperative hospital stay was 7 days. Conclusions: The hand-assisted laparoscopic experience of radical cystectomy learned from the initial 11 patients effectively helped us in the transition to a pure laparoscopic approach. A comparable surgical outcome was found in both groups of patients.
International Journal of Urology | 2004
Yen-Chieh Wang; Jinn-Ming Wang; Yung-Chiong Chow; Allen W. Chiu; Stone Yang
Abstract Pneumomediastinum, a collection of mediastinal air, often results from the rupture of intrathoracic structures. A 41‐year‐old diabetic woman initially presented with signs of pneumomediastinum and nuchal subcutaneous emphysema, but was finally diagnosed with unilateral emphysematous pyelonephritis. Pneumomediastinum as a presentation in retroperitoneal infection has not been reported previously, which prompts us to discuss its etiology and emphasize the importance of physical examination.
Urology | 2009
Marcelo Chen; Yu-Chuen Huang; I-ling Ko; Stone Yang; Yen-Hwa Chang; William J.S. Huang; Yi-Ming Arthur Chen
OBJECTIVES To determine the association of a common variant, rs1447295, at the 8q24 region with prostate cancer (PCa) risk in Taiwanese men. Common variants at the 8q24 region have been shown to be associated with PCa risk. The variant rs1447295 has shown the strongest association. Most of the studies have been performed in European and American populations. METHODS This case-control study comprised 340 PCa patients and 337 controls. Genotyping was performed for rs14417295 to test for the association between its risk allele and PCa. Its association with disease stage, Gleason score, PSA level, and disease aggressiveness was also determined. RESULTS The A allele of rs1447295 was significantly associated with increased PCa risk (odds ratio = 1.49, 95% CI = 1.12-1.99). When compared with controls, the risk allele A was more frequent in PCa patients of both stages I+II (P = .028) and stages III+IV (P = .023), in patients of all Gleason scores (P < .05 in all subgroups), in patients with PSA levels >20 ng/mL (P = .001), and in patients with aggressive disease (P = .005). CONCLUSIONS This study confirmed that the A allele of rs1447295 is associated with a high risk of PCa in Taiwanese men.
Experimental Biology and Medicine | 2007
Yung-Chiong Chow; Stone Yang; Chun-Jen Huang; Chin-Yuan Tzen; Yu-Hsien Su; Paulus S. Wang
The objective of this study is to investigate the potential protective effects of intravesical instillation of epinephrine in cyclophosphamide-induced hemorrhagic cystitis. In an earlier study, we have shown that epinephrine promotes hemostasis on established hemorrhagic cystitis induced by cyclophosphamide. Female Sprague-Dawley rats were divided into seven groups as follows: group 1: positive control (150 mg/kg, cyclophosphamide, i.p.), group 2: negative control (10 μ g/ml, epinephrine, intravesical), co-administration of cyclophosphamide (150 mg/kg, i.p.), group 3: saline (intravesical), groups 4–6: epinephrine (2.5, 5, and 10 μ g/ml, intravesical), and group 7: mesna (50 mg/kg, i.p.). Rats were sacrificed on 3 consecutive days and the urinary bladders were removed, weighed, and evaluated. The vesical vascular permeability was determined by wet bladder weight and Evan’s blue dye absorbance. After 24 hours of cyclophosphamide administration, severe hemorrhagic cystitis was induced with marked edema, hemorrhage, and inflammation. In the epinephrine-treated groups, symptoms of hemorrhagic cystitis (such as edema, inflammation, and hemorrhage) were reduced significantly. Intravesical instillation of epinephrine prevents edema, hemorrhage, and inflammation in rats with cyclophosphamide-induced hemorrhagic cystitis.
Urology | 2002
Chung-Lieh Hung; Chih-Jen Wu; Stone Yang; Han-Hsian Chen; Johnson Lin
Transurethral resection of the prostate (TURP) for the treatment of benign prostatic hyperplasia may lead to TURP syndrome, and in some cases, acute renal failure can develop. Hemolysis does happen during TURP. Whether hemolysis itself leads to acute renal failure merits discussion. We report a patient with chronic renal insufficiency who developed oliguric acute renal failure immediately as a major complication after TURP. The renal function of this patient recovered after six hemodialysis sessions, and the patient continued to do well in the subsequent follow-up period.
Urologia Internationalis | 2005
Jong-Ming Hsu; Marcelo Chen; Wen-Chou Lin; Huang-Kuang Chang; Stone Yang
Introduction: Retrograde decompression is generally not advocated for patients with sepsis owing to ureteral obstruction by stone impaction, and the initial treatment of choice is percutaneous nephrostomy (PCN). We report our experience with the treatment of urosepsis with retrograde ureteroscopy (URS) instead of PCN drainage. Patients and Methods: Fifty-six consecutive patients diagnosed with ureteral stone-related sepsis received URS as primary treatment at our institution. Patients with uncontrollable sepsis underwent emergent URS and hemodynamically stable patients underwent elective URS within two days of diagnosis. Results: URS was successful in 53 (94.6%) of the 56 patients. PCN was performed in the 3 cases of URS failure. Internal ureteral stenting was performed in 48 patients. Secondary procedures were performed in 10 (18.9%) patients. Twenty-six patients suffered from postoperative fever for an average of 1.6 days (range 1–4 days). There were no anesthesia-related morbidities, postoperative exacerbations of the clinical condition, or postoperative deaths. The median length of hospital stay was 7 days (range 3–94 days). Conclusion: PCN drainage is the standard treatment of sepsis associated with ureteral stone obstruction. However, our results show that URS can be safely and successfully performed by skilled endourologists in select clinical situations.