Biomedical subjects

Young Deuk Choi

Publications and source records attributed to Young Deuk Choi.

13 recordsLinked to original sources

PubMed2026

Transcriptome-based high-frequency recurrence index predicts frequent recurrence in non-muscle-invasive bladder cancer after Bacillus Calmette-Guérin therapy.

BACKGROUND: High-frequency recurrence (HfR, ≥ 2 recurrences) in non-muscle-invasive bladder cancer (NMIBC) poses a significant clinical burden. Current risk models, such as the European Organization for Research and Treatment of Cancer (EORTC), the European Association of Urology (EAU), and the UROMOL classification, offer limited predictive accuracy for identifying patients at risk for frequent recurrence despite appropriate treatment. METHODS: A 75-gene high-frequency recurrence index (HfRI) was constructed by selecting recurrence-associated genes using differential expression and Cox regression analyses. The HfRI was computed as a weighted sum of normalized gene expression values. The model was trained on a discovery cohort and validated in multiple cohorts (n = 1379) using machine-learning approaches. Clinical relevance was assessed using recurrence-free survival (RFS) and Cox models, and predictive performance was compared with that of the EORTC, EAU, and UROMOL classifications using the area under the curve (AUC) and the concordance index (c-index). RESULTS: The HfRI robustly stratified patients into high-risk and low-risk groups across six independent NMIBC cohorts. Patients classified as HfRI-high had a significantly greater likelihood of experiencing ≥ 2 recurrences (χ2, p = 0.001) and showed markedly reduced RFS (log-rank test, p < 0.001). The adverse prognostic effect of the HfRI persisted even among patients treated with BCG therapy (log-rank test, p = 0.02). Multivariate analysis revealed that the HfRI was an independent predictor of HfR (HR = 2.82, 95% CI = 1.89-4.20, p < 0.001). Compared with established clinical risk classifiers, the HfRI demonstrated superior predictive performance (AUC = 0.736, c-index = 0.673) in terms of the EORTC (AUC = 0.594), EAU (AUC = 0.557) risk groups, and UROMOL2021 (AUC = 0.596) classification. Pathway analysis revealed that HfRI-high tumors were characterized by upregulation of cell cycle progression and DNA replication pathways, accompanied by suppression of immune signaling pathways. These biological features provide a mechanistic explanation for the reduced responsiveness to intravesical BCG therapy, underscoring the role of HfRI not only as a predictor of recurrence risk but also as a biomarker capable of identifying patients unlikely to benefit from standard BCG treatment. CONCLUSIONS: HfRI represents a robust, transcriptome-based tool for predicting frequent recurrence in NMIBC patients. The HfRI supports earlier identification of patients at risk of high-frequency recurrence, thereby supporting personalized treatment strategies.

Humans↗

PubMed2006

Detection rate of prostate cancer on biopsy according to serum prostate-specific antigen in Korean men: a multicenter study.

OBJECTIVES: To evaluate the detection rate of prostate cancer on biopsy according to the serum prostate-specific antigen (PSA) level in Korean men and compare the detection rate with those of Japanese and American men in other studies. METHODS: We retrospectively analyzed 2422 Korean men who had undergone prostate biopsy at 12 medical centers from 1993 to 2002. In the case of a PSA level greater than 4.0 ng/mL or abnormal digital rectal examination findings, prostate biopsy was performed. RESULTS: Of the 2422 men, 962 (39.7%) were diagnosed with prostate cancer. With PSA levels between 4.0 and 10.0 ng/mL, the detection rate of prostate cancer was 15.9%. This rate was similar to that of Japanese men (15.8%), but lower than that of American men (25%). In the cases with a PSA level greater than 10.0 ng/mL, the detection rate for Korean and Japanese men was 59.5%, and was also lower than the 67% rate for American men. When serum PSA levels were divided into five subgroups (less than 4.0, 4.0 to 10.0, 10.0 to 20.0, 20.0 to 100.0, and greater than 100.0 ng/mL), the detection rate of prostate cancer was 12.4%, 15.9%, 34.1%, 66.2%, and 93.8%, respectively. CONCLUSIONS: In Korean men, the detection rate of prostate cancer on biopsy according to serum PSA level appears to be comparable to that for Japanese men and lower than that for American men.

Adult↗

PubMed2006

Long-term effects of ileal conduit urinary diversion on upper urinary tract in bladder cancer.

OBJECTIVES: To evaluate the functional and morphologic changes of the upper urinary tract after radical cystectomy and ileal conduit urinary diversion for bladder cancer. METHODS: Radical cystectomy and ileal conduit urinary diversion were performed in a total of 249 patients with bladder cancer at our hospital from 1980 to 1999. Of the 249 patients, 67 were excluded because of the presence of preoperative lesions in the upper urinary tract or elevated serum creatinine (greater than 1.4 mg/dL). Of the remaining 182 patients, 82 were also excluded because of incomplete follow-up or death less than 5 years after surgery. RESULTS: Of the 249 patients, a total of 100 (40.2%) who had no preoperative lesions in upper urinary tract and normal renal function and survived 5 years or longer were included in this analysis. The median follow-up period was 91 months (range 60 to 193). The serum creatinine was greater than the normal range in 10 patients (10.0%), and radiologic changes in the upper urinary tract were observed in 14 patients (14.0%). They had diabetes mellitus nephropathy (4.0%) or specific comorbidities that could contribute to the deterioration of the upper urinary tract, such as ureteroileal anastomotic stricture (4.0%), chronic pyelonephritis (4.0%), urinary stones (1.0%), and upper urinary tract tumor (1.0%). CONCLUSIONS: The results of our study have shown that the functional and morphologic changes in the upper urinary tract after radical cystectomy and ileal conduit urinary diversion occur in patients with specific comorbidities that could contribute to those changes. Different from previous reports, none of the upper urinary tract changes developed without an obvious cause.

Adult↗

PubMed2005

Loss of Cyclin B1 followed by downregulation of Cyclin A/Cdk2, apoptosis and antiproliferation in Hela cell line.

Recent studies have shown that Cyclin B1 is overexpressed in various tumor types but present at low levels in normal tissues. To explore the possibility of employing Cyclin B1 as an anticancer target, we knocked down Cyclin B1 in an HeLa cell line using RNA interference (RNAi). Subsequently, we monitored cell cycle-related molecules by Western blot together with immunofluorescence and determined cell cycle distribution by flow cytometry. XTT and soft agar colony growth experiments were performed to detect cell viability and proliferation. Furthermore, we analyzed cell apoptosis by measuring Bcl-2 and Bax protein level and DNA-ladder assay. After performing Cyclin B1 RNAi, Cyclin B1, Cyclin A and Cdk2 protein levels were found to be markedly downregulated, whereas Cdc2 was almost unaffected; S-phase fraction increased significantly; HeLa cell viability and cell colony forming ability were markedly diminished after the RNAi; Bcl-2 was noticeably attenuated but Bax was hardly changed; and HeLa cells displayed typical DNA ladder. The loss of Cyclin B1 resulted in the downregulation of Cyclin A and Cdk2, S-phase delay and eventually led to cell apoptosis and the decrease of cell viability and proliferation. Our studies suggest that Cyclin B1 may be a promising anticancer target.

Apoptosis↗

PubMed2005

Extramammary Paget's disease of penis and scrotum.

OBJECTIVES: To make clear the uncertainty of the clinical outcome of extramammary Paget's disease (EMPD). Penile and scrotal involvement of EMPD is exceedingly rare, and only small series or case reports have been reported. METHODS: From 1995 to 2003, 36 patients with penile and scrotal EMPD were treated and followed up. Local wide excision was done in all patients with or without intraoperative frozen biopsy analysis. RESULTS: Of the 36 patients, 13 (36.1%) underwent intraoperative frozen biopsy analysis and only 1 patient (7.7%) had a positive surgical margin. However, 23 (63.9%) underwent local wide excision with excessive surgical margins of up to 1 to 2 cm only by gross examination, but 17 (73.9%) of them had positive surgical margins (P <0.01). Of the 17 patients with positive surgical margins, 8 developed local recurrence at a median of 8 months of follow-up (P <0.05). One patient who had invasion to the subcutaneous tissue died of metastatic EMPD and internal malignancy (renal cell carcinoma) at 17 months after the initial operation. No patient had underlying adnexal carcinoma. CONCLUSIONS: The results of our study indicate that local wide excision with intraoperative frozen biopsy analysis is essential to the complete treatment of EMPD.

Aged↗

PubMed2005

Vesicoureteral reflux in adult women with uncomplicated acute pyelonephritis.

OBJECTIVES: To evaluate the significance of vesicoureteral reflux (VUR) in adult women with uncomplicated acute pyelonephritis. METHODS: Eighty-six adult women with uncomplicated acute pyelonephritis were studied from April 1998 to October 2003. They showed no structural urinary tract abnormalities. The mean age of patients was 36.2 years (range, 19 to 54 years). We divided these patients into two groups. In group I (31 patients), we performed a voiding cystourethrogram (VCUG) on the third day of treatment to demonstrate possible transient low-grade VUR during the acute infectious phase. In group II (the remaining 55 patients), we performed VCUG after the seventh day of treatment. RESULTS: There were only 2 (2.3%) cases of VUR among 86 patients with uncomplicated acute pyelonephritis. No VUR was found in group I, and grade II reflux was found in 2 patients of group II. CONCLUSIONS: These results indicate that, unlike in children, VUR is not a significant factor causing ascending infection leading to the development of acute pyelonephritis in adult women. Further research is warranted regarding the pathophysiology of ascending infection in the adult population.

Acute Disease↗

PubMed2005

Juvenile prostatic hyperplasia.

Benign prostatic hyperplasia is common in aging men, but rare in childhood. We report a case of juvenile prostatic hyperplasia in a 10-year-old boy, who visited our clinic for hematuria and voiding symptoms. Radiologic studies revealed a huge prostate protruding into the bladder. The prostate was 33 g. The prostate biopsy showed no evidence of cancer. At 13 years of age, he was seen again because of general weakness, fever, and voiding difficulty. Bilateral hydroureteronephrosis was found on radiologic studies, and his serum creatinine was elevated. The prostate was 55 g. Suprapubic prostatectomy was performed.

Age Factors↗

PubMed2005

Lymphovascular and marginal invasion as useful prognostic indicators and the role of c-erbB-2 in patients with male extramammary Paget's disease: a study of 31 patients.

PURPOSE: Extramammary Paget's disease (EMPD) is a rare intraepithelial neoplasm arising in skin that bears apocrine glands. We analyzed clinical, pathological and immunohistochemical staining patterns in 31 cases of EMPD to assess possible predictors of outcome, including patient age, sex, involved organs, surgical margin status, invasion depth, lymphovascular invasion, adnexal invasion, and immunoreactivity for cytokeratin 7 and 20, carcinoembryonic androgen, androgen receptor, p53, c-erbB-2 (Dako, Carpinteria, California) and Ki67. MATERIALS AND METHODS: A total of 31 cases of EMPD were retrieved from the surgical pathology files of the department of pathology along with the medical records of the department of urology. Dermal invasion depth, tumor margin status, adnexal invasion and lymphovascular invasion were determined from the hematoxylin and eosin stained slides of each case. RESULTS: Eight of the 31 cases (25.8%) experienced local recurrence. Two of 3 patients with and 6 of 28 without lymphovascular invasion experienced recurrence (p = 0.029). Dermal invasion significantly correlated with Her-2 over expression (Wilcoxon 2-sample test p = 0.0007). When the criteria of 1 and 5 mm invasion were applied, each validly correlated with Her-2 over expression. Her-2 over expression (grades 2 and 3) significantly correlated with p53 over expression (Wilcoxon rank test p = 0.0015). C-erbB-2 was positive in 51.6% of EMPD cases, in which it was strongly associated with dermal invasion and p53 over expression. CONCLUSIONS: The most valid prognostic factor in male EMPD for predicting late recurrence is lymphovascular permeation and marginal status.

Aged↗

PubMed2005

Malignant glomus tumor of the urinary bladder.

We present a case of a malignant glomus tumor arising in the urinary bladder of a 57-year-old woman with metastatic pulmonary nodules who died 2 months later. Pathologically and clinically confirmed malignant glomus tumors are exceedingly rare, especially those that arise in the visceral organs. The present case retained its architectural similarity to a benign glomus tumor and consisted of sheets of highly malignant round cells showing cytoplasmic positivity for smooth muscle actin. On reticulin histochemical staining, we found that reticulum fibrils surrounded individual tumor cells, suggesting cellular investment by basement membrane. We discuss the concept of malignant glomus tumors and emphasize the criteria that distinguish them from other malignant tumors.

Aged↗

PubMed2004

Solitary fibrous tumor of the urinary bladder.

Solitary fibrous tumor (SFT) is a distinct spindle cell tumor arising mainly in the pleura, however, SFT of extra-pleural sites had been reported. To our knowledge, five cases of the urinary bladder SFT had been reported. We have recently experienced a case of SFT of the urinary bladder in a 56-year- old man who was admitted to the hospital with a 4-month history of voiding difficulty, frequency, and residual urine sensation. A computerized tomography scan revealed a 12cm sized intravesical mass. The mass was marginally excised under the impression of it being a benign spindle cell tumor by pre-operative needle biopsy. On gross examination, the mass was multinodular, creamy white, and the cut surface was fibrotic with a rubbery consistency. Microscopic examination revealed haphazardly arranged spindle cells with a lace-like deposition of inter- and pericellular collagen. Areas of increased cellularity show nuclear atypia and occasional mitoses (2-3/10HPF). The immunohistochemical staining revealed an intense CD34 and bcl-2 immunoreactivity. Although the exact biologic behavior of these tumors has not been clarified, most of the reported cases have undergone a benign clinical course.

Humans↗

PubMed2004

Estrogen receptor is significantly associated with the epithelioid variants of renal angiomyolipoma: a clinicopathological and immunohistochemical study of 67 cases.

Perivascular epithelioid cells (PEC) in angiomyolipoma (AML) were recently proposed to be its most common progenitor cells. Histologically, triphasic components were present in various proportions, but were overwhelmingly myogenic in epithelioid variants of AML. Despite histological discrimination, the immunophenotypic profiles between triphasic and epithelioid AML have never been compared. The aim of the present study was to clarify the identity of PEC by using immunoreactivity to estrogen receptor (ER), progesterone receptor (PR), bcl-2 and placenta alkaline phosphatase (PLAP), and to use this information to compare triphasic and epithelioid AML. A total of 33 out of 67 cases of renal angiomyolipoma that underwent surgery were reviewed over the period 1998-2003. Two cases were associated with tuberous sclerosis. Ten patients had other malignant tumors, and three patients had a nodal extension. Immunohistochemistry showed that bcl-2 (59.4%), PLAP (46.9%), HMB-45 (100%) was predominantly localized around vessels. The stem cell markers were absolutely negative in all AML types. The estrogen receptors were positive in 14 cases (42.4%) and the progesterone receptors were positive in five cases. Bcl-2 and both female sex hormone receptors were significantly more frequent in the epithelioid variant of AML than in the triphasic type. Perivascular epithelioid cells express bcl-2, ER, PR and PLAP, and ER could be partly associated with myogenic proliferation.

Alkaline Phosphatase↗

PubMed2003

Increased expression of matrix metalloproteinase 9 correlates with poor prognostic variables in renal cell carcinoma.

BACKGROUND: MMP2 and MMP9 are two gelatinolytic enzymes, which are key regulators of tumor invasion and metastasis. This study aimed to clarify the prognostic significance of MMP2 and MMP9 with particular regard to their transcript levels, enzymatic activities in renal cell carcinomas (RCCs). MATERIALS AND METHODS: Through cDNA array, the differential expression of the MMP superfamily was evaluated in RCC. Various properties of MMP2 and MMP9 were quantified, in 178 patients with RCC, based on the Heidelberg classification. Of these, 145 cases including 16 fresh-frozen cases were available for MMP2 and MMP9 transcript level evaluation. In addition, gelatinolytic activity was assessed by zymography in 16 other fresh-frozen samples from new RCC cases. RESULTS: MMP2, 9, 11, 14, and 16 were upregulated in the conventional RCC in comparison with the chromophobe RCC, whereas MMP1, 11 and 16 were pronounced in papillary RCC. MMP9 transcript levels were strongly associated with the MMP9 enzymatic activity (p=0.001), and therefore, with disease-free survival (p=0.001) and metastasis (p=0.011). Gelatinolytic activity of MMP9 by zymography was strongly associated with MMP9 mRNA expression, which was more intense in 'conventional' RCC than in 'chromophobe' RCC (p=0.001), irrespective of tumor grade or stage. MMP9 was proven to be a significant prognostic predictor by multi-variate survival analysis (p=0.0054). MMP2 enzymatic activity disappeared in spite of its constant transcript expression in RCC. CONCLUSIONS: MMP9 appears to be regulated at the transcript level, whereas MMP2 is regulated at the posttranscriptional level. Poor survival with a high frequency of metastases in 'conventional' RCC is associated with MMP9, which exhibits a high transcriptional level, and a high gelatinolytic activity. As a result, MMP9 may be a candidate of predictors of disease-free survival in RCC.

Carcinoma, Renal Cell↗

PubMed2002

SS-penogram: a new diagnostic test for erectile dysfunction.

The clinical reports on Sildenafil sulfate (Viagra) are mainly based on individual observations. However, there is a paucity of objective studies in the literature. In order to objectively examine the effect of Sildenafil, a SS (Sexual Stimulation)-Penogram that is a non-invasive, simple and physiologic method was developed using a radioisotope (RI). One hundred and four SS-penograms were performed on patients who had a documented erectile dysfunction (ED) lasting for more than 6 months. After an intravenous injection of 99mTc-RBC (15 mCi), the first penogram was taken immediately after sexual stimulation, which was done by 30 minutes of erotic videotape viewing. Forty minutes after administering 25 to 100 mg of Sildenafil, a second penogram was taken. The characteristics of each penogram were analyzed according to a previously reported method. The results were graded as follows; Type I(normal function; 5 min or more of peak erectile response with an induction period of 1 to 6 min), Type II-A (impossible function type; i.e., showing less than 2 times the basal radioactivity level), Type II-B (the unstable type; showing less than 5 min of peak erectile response), and Type II-C (the delayed type; which showed a delay of more than 15 min after the start of sexual stimulation). The patients were grouped according to their response after Sildenafil administration, and the effect of Sildenafil was assessed by comparing the radioactivity from between 7 to 22 minutes and the changes in the characteristics of the penogram. The mean age of the patients was 44.9 +/- 10.2 (23 - 68) years. In the first penogram, Type I was found in 12 patients, and Type II-A in 14, Type II-B in 73, Type II-C in 1 and a mixed (II-B + C) type was found in 4 patients. A second penogram after Sildenafil administration, showed Type I in 46 patients, and Type II-A in 10, Type II-B in 46 and a mixed type was found in 2 patients. The responses after Sildenafil were categorized as follows: 1) An excellent response group (consisting of 56 patients-53.9%); Those who showed greater than 50% increase in the RI area after Sildenafil treatment. 2) A good response group consisting of (23 patients-22.1%); i.e., those who showed a less than 50% but greater than a 20% increase in the RI area after Sildenafil administration. 3) A borderline group (consisting of 15 patients-14.4%); showing less than a 20% change in the RI area after Sildenafil treatment. 4) non-response group (consisting of 10 patients-9.6%). The therapeutic efficacy of Sildenafil, as determined by the SS-penograms, revealed that there was an augmentation in the erectile capabilities in 76% of men (79/104) but a non-response was observed in 9.6% (10/104). The efficacy of Sildenafil on the SS-penogram did not correlate with the patient's age (p=0.198). It is believed that the SS-penogram can be used to accurately evaluate the natural erectile status in sexual and pharmacological stimulation, and provides the most objective erectile response in any therapeutic trial. Consequently, the primary challenge for any erectile dysfunction remedy is to be able to demonstrate its efficacy. A further evaluation is warranted in the non-response group, which was not based on any severe organic dysfunction.

Adult↗