Biomedical subjects

Steven K Huan

Publications and source records attributed to Steven K Huan.

8 recordsLinked to original sources

PubMed2006

Survival analysis in patients with upper urinary tract transitional cell carcinoma: a comparison between open and hand-assisted laparoscopic nephroureterectomy.

OBJECTIVE: To evaluate the stage- and grade-specific survival rate in patients with upper urinary tract (UUT) transitional cell carcinoma (TCC) after open (ONU) or hand-assisted laparoscopic nephroureterectomy (LNU) with bladder-cuff excision. PATIENTS AND METHODS: From January 1998 to April 2005, 143 patients with UUT-TCC were treated with either ONU or LNU and enrolled in the study. The peri-operative data were collected by retrospective chart review. The recurrence, metastasis and survival rate were calculated. RESULTS: The 5-year disease-specific survival of patients with pT1 disease was 88.1% after ONU and 92.0% after LNU (P = 0.745); the respective values for patients with pT2 were 11/17 and 12/15 (P = 0.874), and for pT3 were six/11 and 12/15 (P = 0.476). The incidence of bladder recurrence within 2 years after surgery was 24.7% for ONU and 19.7% for LNU (P = 0.475). CONCLUSION: The results were similar after ONU or LNU with bladder-cuff excision; bladder-cuff excision using a hand-assisted device is effective and serves as a treatment option for patients with UUT-TCC.

Aged↗

PubMed2005

Quercetin, but not rutin and quercitrin, prevention of H2O2-induced apoptosis via anti-oxidant activity and heme oxygenase 1 gene expression in macrophages.

In the present study, we examine the protective mechanism of quercetin (QE) on oxidative stress-induced cytotoxic effect in RAW264.7 macrophages. Results of Western blotting show that QE but not its glycoside rutin (RUT) and quicitrin-induced HO-1 protein expression in a time- and dose-dependent manner, and HO-1 protein induced by QE was blocked by an addition of cycloheximide or actinomycin D. Induction of HO-1 gene expression by QE was accompanied by inducing ERKs, but not JNKs or p38, proteins phosphorylation. Addition of PD98059, but not SB203580 or SP600125, significantly attenuates QE-induced HO-1 protein and mRNA expression associated with blocking the expression of phosphorylated ERKs proteins. H(2)O(2) addition reduces the viability of cells by MTT assay, and appearance of DNA ladders, hypodiploid cells, and an increase in intracellular peroxide level was detected. Addition of QE, but not QI or RUT, significantly reduced the cytotoxic effect induced by H(2)O(2) associated with blocking the production of intracellular peroxide, DNA ladders, and hypodiploid cells. QE protection of cells from H(2)O(2)-induced apoptosis was significantly suppressed by adding HO inhibitor SnPP or ERKs inhibitor PD98059. Additionally, QE protects cells from H(2)O(2)-induced a decrease in the mitochondrial membrane potential and a release of cytochrome c from mitochondria to cytosol by DiOC6 and Western blotting assay, respectively. Activation of apoptotic proteins including the caspase 3, caspase 9, PARP, D4-GDI proteins was identified in H(2)O(2)-treated cells by Western blotting and enzyme activity assay, and that was significantly blocked by an addition of QE, but not RUT and QI. Furthermore, HO-1 catalytic metabolites carbon monoxide (CO), but not Fe(2+), Fe(3+), biliverdin or bilirubin, performed protective effect on cells from H(2)O(2)-induced cell death with an increase in HO-1 protein expression and ERKs protein phosphorylation. These data suggest that induction of HO-1 protein may participate in the protective mechanism of QE on oxidative stress (H(2)O(2))-induced apoptosis, and reduction of intracellular ROS production and mitochondria dysfunction with blocking apoptotic events were involved. Differential anti-apoptotic effect between QE and its glycosides RUT and QI via distinct HO-1 protein induction was also delineated.

Animals↗

PubMed2005

Clinical experience of laparoscopic-assisted radical cystectomy with continent ileal reservoir.

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.

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PubMed2002

Potential molecular marker for detecting transitional cell carcinoma.

OBJECTIVES: To assess the expression rate of a cancer-related gene, hepatoma-up-regulated protein (HURP), in the tumor tissue of transitional cell carcinoma (TCC), and to assess the potential suitability of using this gene as a novel molecular marker for detecting TCC in voided urine. METHODS: Total RNA was extracted from 80 TCC tissue samples of the urinary tract. Forty-five of the 80 tumor-adjacent tissue samples were from the same patients and 15 were from control subjects (patients with benign prostatic hyperplasia). The expression levels of HURP mRNA in these specimens were examined using reverse transcriptase-polymerase chain reaction. The HURP mRNA transcripts in voided urine pellets from 14 additional patients were determined using the same method. The messages were normalized to beta-actin mRNA. RESULTS: The detection of HURP expression in the TCC tissue samples had a sensitivity of 88.8% (71 of 80) and a specificity of 100% (15 of 15). Ten of the 45 grossly tumor-adjacent tissue samples expressed HURP mRNA, which may indicate subtle genetic changes in tissue adjacent to tumor. All seven urine specimens from the patients with TCC revealed HURP expression; however, no specimens from patients with nonmalignant diseases did so. CONCLUSIONS: A potential molecular marker for detecting TCC with tissue specimens and voided urine samples has been found. Although the real clinical application of this marker requires additional evaluation, the high sensitivity and specificity of the HURP gene amplification method warrants more investigation in the future.

Biomarkers, Tumor↗

PubMed2002

Comparison study on two different accessing methods for retroperitoneoscopic adrenalectomy.

OBJECTIVES: To compare, in a retrospective nonrandomized study, two retroperitoneal laparoscopic access methods for treatment of adrenal tumors: direct needle insufflation with balloon dissection and finger-assisted dissection without balloon dissection. METHODS: The operative data from 120 consecutive patients undergoing retroperitoneoscopic adrenalectomy (RA) for benign adrenal tumors were reviewed. The operative outcomes of 70 RAs accessed by direct needle insufflation and balloon dissection were compared with another 50 RAs accessed by finger dissection without balloon dissection. The RA surgical parameters for tumors with different laterality, pathologic features, and size were also analyzed. RESULTS: The operative time in the finger dissection group was shorter (118 +/- 11 minutes) compared with that in the balloon dissection group (143 +/- 21 minutes; P = 0.03). The surgical parameters, including incidence of peritoneal perforation, intraoperative blood loss, time to oral intake, analgesic requirement, postoperative hospital stay, and convalescence, did not differ between the groups. For tumors greater than 5 cm, the operative time increased to 220 +/- 30 minutes compared with 132 +/- 31 minutes for tumors 5 cm or less (P = 0.02). The finger and balloon dissection methods had similar operative times for tumors larger than 5 cm (218 +/- 10 versus 224 +/- 15 minutes). No additional morbidity regarding the recovery time was noted in the finger dissection group compared with the balloon dissection group. CONCLUSIONS: Finger dissection appears to be a more efficient and equally effective access method for RA compared with balloon dissection. We suggest that balloon dissection may not be required for RA in patients not excessively obese.

Adrenal Gland Neoplasms↗

PubMedDate not supplied

A feasible tool to detect mRNA expression of matrix metalloproteinases and their tissue inhibitors in human Tenon's capsule.

PURPOSE: To determine the mRNA expression of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) in human specimens of Tenon's capsule. METHODS: Reverse transcription-polymerase chain reaction (RT-PCR) with specific primers for MMP-1, MMP-2, MMP-9, TIMP-1 and TIMP-2 was performed on tissue specimens obtained from patients with cataract, rhegmatogenous retinal detachment, glaucoma, or diabetes mellitus. RESULTS: Glyceraldehyde phosphate dehydrogenase (GAPDH) mRNA transcripts were detected in 26 (76.5%) of 34 specimens, with almost the same amount of expression in each of these samples. Messenger RNA expression of one or more of the MMPs/TIMPs could also be detected in all of these 26 samples, but not in any sample without GAPDH expression. MMP-2, TIMP-1 and TIMP-2 were detected in 25 (96.2%) of the 26 samples with GAPDH expression, while MMP-1 and MMP-9 were detected with a lower percentage (34.6 and 19.2%, respectively). CONCLUSION: The feasibility of RT- PCR with GAPDH as an internal standard to determine mRNA transcripts of the MMPs and TIMPs in the subconjunctival Tenon's capsule was demonstrated.

Conjunctiva↗

PubMedDate not supplied

Prognostic significance of hepatoma-up-regulated protein expression in patients with urinary bladder transitional cell carcinoma.

We recently found a urinary molecular marker, Hepatoma-Up-Regulated Protein (HURP), for the detection of urinary bladder transitional cell carcinoma (TCC). In this study, the expression of HURP in 57 voided urine specimens was determined by semi-quantitative reverse transcriptase-polymerase chain reaction. HURP value was correlated with a variety of clinical parameters, including sex, age, tumor grade, stage, multiplicity, tumor shape and recurrence/metastasis during the follow-up period. The detection rate of HURP was 60.7% (17 out of 28) in voided urine of patients with TCC, 5.9% (1 out of 17) in non-TCC urological benign disease and 0% (0 out of 12) in healthy volunteers. HURP positivity (defined as above 0.1 cut-off value) was detected in 83.6% (92 out of 110) TCC specimens, 4.3% (1 out of 23) of non-TCC urinary cancer and 0% (0 out of 15) of benign urological disease. No relationship was found between the level of HURP and the above-mentioned clinical parameters other than recurrence of TCC patients. A higher level of tissue HURP was found in the patients having recurrence (Mann-Whitney U-test, p = 0.027).

Aged↗

PubMedDate not supplied

Efficacy of ultrasonic tissue dissector and tissue glue for laparoscopic partial nephrectomy in a porcine model.

The purpose of this study was to evaluate the efficacy and long-term tissue effects of ultrasonic dissector and cyanoacrylate glue during laparoscopic partial nephrectomy in a porcine model. Nine domestic pigs underwent laparoscopic left lower pole partial nephrectomy without vascular control. An ultrasonic tissue dissector was used to assist in the parenchymal incision, and the raw surfaces of the kidneys, including the exposed urinary system, were sealed with cyanoacrylate glue. No internal stents or additional sutures were placed. Intraoperative hemorrhages and urinary extravasation were recorded. The animals were humanely killed 28 days after undergoing the operations. The long-term effects of ultrasonic dissector and cyanoacrylate glue on the healing process of urothelium and renal parenchyma were determined histologically. All pigs survived the laparoscopic partial nephrectomy, and the blood loss ranged from 0 to 120 ml (mean, 60 ml). The average operative time was 89 +/- 10 min. The severity of the bleeding was minimal in six animals and moderate in three animals. No urinary extravasation was found using intravenous urography at the 28th postoperative day. No urinary fistula or renal abscess formation was found histologically. Cyanoacrylate glue infiltrated into the tissue defects and did not dissolve. The glue was encased by fibrotic tissue with minimal foreign body inflammatory reaction. Ultrasonic dissector was effective in achieving hemostasis during laparoscopic partial nephrectomy without the need of vascular control in pigs. Cyanoacrylate glue achieved good long-term adhesive power. The sealing effects provided by cyanoacrylate glue were adequate to prevent urinary extravasation from urothelial defects at least for 1 month.

Animals↗