3,552 research outputs found
Association of midline prostatic cysts and lower urinary tract symptoms: A caseâ control analysis of 606 transrectal ultrasound findings
No full textObjectiveTo evaluate the association between midline prostatic cysts (MPCs) and lower urinary tract symptoms (LUTS).MethodsA total of 606 patients who underwent transrectal ultrasound of the prostate (TRUS) were retrospectively reviewed. Patients were divided into two groups based on the presence of MPCs for comparison. We used the International Prostate Symptom Score (IPSS) as a LUTS parameter. Multivariate analysis was performed to find out independent predictors for moderate to severe LUTS. An MPC subgroup analysis was done to look for linear correlation between the size of MPCs and LUTS.ResultsPatients with no MPCs were of higher age, had more history of diabetes, were taking more urological medications, and had more IPSS storage symptoms. No significant differences were found in body mass index, total IPSS, voiding IPSS, bother score, total prostateâ specific antigen level, and the prostate size. Multivariate analysis revealed age, history of diabetes, taking urological medications, and the prostate size as independent predictors of moderate to severe LUTS. The presence of MPCs was not an independent factor. Subgroup analysis failed to show significant correlation between the size of MPCs and the LUTS scores.ConclusionsThe presence of MPCs is not an independent factor for moderate to severe LUTS, and the size of the MPCs does not have any correlation to LUTS scores either.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/152931/1/luts12288.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/152931/2/luts12288_am.pd
Initial experience of a novel ureteral silicon-covered metallic mesh stent in malignant ureteric obstruction: a single-center retrospective study
No full textBackground: This study aimed to investigate initial experiences and outcomes of a retrograde inserted new silicone-covered metallic ureteric stent (Urexel™) for malignant ureteric obstruction. Methods: We retrospectively reviewed the medical records for 12 consecutive patients who underwent Urexel™ stent placement for malignant ureteric obstruction from March 2020 to March 2021. The Urexel™ stent is a segmental metallic ureteric stent composed of a nitinol mesh covered with a silicone membrane. We evaluated the clinical outcomes and complications of this new metallic ureteric stent. Results: The median age of patients was 61.5 (44–82) years, and the median follow-up was 25.5 (4–37) months. One of the 12 patients underwent bilateral stent insertion, Urexel™ stents were placed in a total of 13 ureteral units. There was no technical failure during stent placement. The median length of obstructions was 9 (1–22) cm. Balloon dilation was necessary in 38.5% (5/13 ureter units) of cases. The 6-month success rate was 83.3%, 1-year success rate was 70%, and estimated success rate was 44.4% at 2-year. Encrustation, migration and hyperplasia were the cause of overall treatment failure in all 6 cases of failure, with median elapsed time to failure of 9.5 (1–30) months. Common complications included persistent pain, acute pyelonephritis, and lower urinary tract symptoms, but they were Clavien-Dindo grade I or II. Conclusions: In this initial series of novel ureteral silicon-covered metallic mesh stents, Urexel™ provided acceptable success and complication rate in malignant ureteric obstructions
Comparison of plasma generation behaviors between a single crystal semiconductor bridge (single-SCB) and a polysilicon semiconductor bridge (poly-SCB)
No full textA single crystal semiconductor bridge (single-SCB) has been fabricated by a micro-electro-mechanical system (MEMS) technique based on anisotropic wet etching, where an air gap replaces the oxide layer NOD used as a thermal insulating barrier in the conventional polycrystalline semiconductor bridge (poly-SCB). Upon flowing current in the single-SCB and the poly-SCB, the single-SCB exhibits a second peak of plasma generation at 500 ns, whereas that of the poly-SCB is founded at 600 ns. The results of an electrical experiment are analyzed through a finite element analysis and a simple discrete-element modeling of the thermal structure. From these investigations, it is clear that more effective heat conduction related to the plasma discharge behaviors is achieved in the single-SCB with a simpler thermal structure. (C) 2004 Elsevier B.V. All rights reserved
Survey on disease insight and prevalence of urinary incontinence in women
No full textPurpose: With a rapidly aging population in Korea, the number of patients with lower urinary tract symptoms is increasing. Therefore, it is important to determine the current extent of incontinence among Korean women to establish future plans. We attempted to create reference materials for organizing public relations and educational activities by investigating the effect of age on incontinence and quality of life in women. Materials and Methods: The participants comprised women aged 30 years and older who visited a tertiary center for health screening from September 1 to October 31, 2016. The survey included a questionnaire consisting of 12 questions that took approximately 10 minutes to complete. We analyzed the responses and assessed the prevalence of the disease and its rate of recognition. Results: A total of 509 women completed the survey. Irrespective of age, 76.8% of all respondents were aware of urinary incontinence (UI) and 57.4% of the women exhibited lower urinary tract symptoms. The most prevalent symptom was UI (45.8%), and the incidence rates of stress and urge UI were identified as 33.6% and 12.2%, respectively. Only 8.0% of the women had visited a hospital; 38.3% had awaited spontaneous symptom improvement. Many participants (61.2%) answered that a urology clinic is suitable for treating UI, while 58.9% chose a gynecology clinic. Conclusions: Our study showed that more than 75% of women are aware of UI, but their perception of the disease mechanism and treatment options was low. We suggest that continuous education and publicity are necessary
The presence of prostate-specific antigen checked more than 1 year before diagnostic biopsy is an independent prognostic factor in patients undergoing radical prostatectomy
No full textPurpose: In large scale prospective studies, prostate-specific antigen (PSA)-screening not only decreased prostate cancer mortality, but also reduced biochemical recurrence (BCR) in patients undergoing radical prostatectomy (RP). We investigated the independent effect of the presence of PSA checked more than 1 year before diagnostic biopsy on the prognosis of patients undergoing RP in a real world setting without PSA-screening. Materials and Methods: We reviewed the database of patients undergoing RP at Ajou University Hospital from March 1999 to May 2018. Clinicopathological features assessed were age, presence of lower urinary tract symptoms at presentation, presence of PSA checked over 1 year before biopsy, presence of PSA checked within 4 to 1 years of biopsy, last pre-biopsy PSA (pPSA), biopsy grade group (bGG), cT, cN, percentage of positive biopsy cores (PPBC), pathological GG (pGG), pT, pN, surgical margin, and index tumor diameter. The primary endpoint was BCR-free survival (BCRFS). Results: Of 598 patients enrolled, 211 experienced BCR at the mean follow-up of 64±37 months. The 5-year and 10-year BCRFS were 62.8% and 53.9%, respectively. In multivariate analyses including clinical variables only, pPSA, bGG, cT, PPBC, and PSA within 4 to 1 years of biopsy independently affected BCRFS. In multivariate analyses including pathological variables only, pPSA, pGG, pT, pN, PSA checked over 1 year before biopsy and PSA checked within 4 to 1 years of biopsy independently affected BCRFS. Conclusions: Patients who has checked PSA at least once beyond 1 year before diagnosis of prostate cancer show better BCRFS regardless of other factors
Nonlinear optical interaction in photonic structures / Lee Choo Yong
No full textIn this thesis, we investigate second harmonic generation (SHG) in nonlinear 1 dimensional (1D) bilayer periodic photonic crystal with various microstructure designs.
The transfer matrix is used to model propagation of fundamental field (FF) and second harmonic field inside photonic crystal and numerical simulations are studied.
Firstly, we investigate SHG caused by interaction between continuous wave and dielectric magnetic photonic crystal. For nondispersive material, constant and real permittivity
and permeability are used being good approximation for frequency far away from the resonant region. We find interesting features in the SH fields versus pump frequency
and relative thickness of the bilayers for the same real value of permittivity and permeability but with different signs. Negative permeability is a substitute to periodical
poling, giving stronger SH signal when one of the layers has negative refractive index.
For certain parameters, backward and forward SH signals can be generated over a broad frequency range. For dispersive material, around resonant region, the FF spectra show
more predictable features of bandgap and transparency windows. SH spectra show irregular patterns that depend on the magnetic and dielectric resonances of each layer. The
results provide insights for designing efficient nonlinear photonics devices with dieletricmagnetic materials like efficient frequency converter.
Secondly, ultrashort pulse propagation and SHG in photonic crystal with superconducting layer is studied by using a combination of Fourier transform and transfer matrix
for arbitary pulse propagation. Two fluid model is used to describe electromagnetic propagation in the superconducting layer at nonzero temperature. The focus is on temperature
dependence and negative index using superconducting layer and magnetic materials when the superconducting transition frequency is close the magnetic resonance. At low
temperature, the superconducting layer provides higher SHG conversion efficiency. Interesting features observed include output pump and second harmonic pulses that could
be strongly modulated with the transmitted pulses being delayed by slow light effect.
The result demonstrates a new mechanism for reshaping and converting short pulse by combining resonant multiple scattering and nonlinear optical process
Sites of Metastasis and Survival in Metastatic Renal Cell Carcinoma: Results From the Korean Renal Cancer Study Group Database
No full textBackground: In patients with metastatic renal cell carcinoma (mRCC), sites of metastatic involvement have been reported to be associated with a difference in survival. However, the frequency and survival according to different sites of metastases in Korean patients with mRCC remain unclear. Therefore, this study aimed to assess the frequency of metastatic site involvement and the association between sites of metastatic involvement and survival in Korean patients with mRCC. Methods: This retrospective study used the multicenter cohort of the Korean Renal Cancer Study Group mRCC database to identify patients who started targeted therapy between December 2005 and March 2018. Data on the frequency of metastatic organ involvement at the time of mRCC diagnosis and oncologic outcomes according to different sites of metastasis were analyzed. Results: A total of 1,761 patients were eligible for analysis. Of the 1,761 patients, 1,564 (88.8%) had clear cell RCC, and 1,040 (59.1%) had synchronous metastasis. The median number of metastasis sites was 2 (interquartile range [IQR], 1–6). The median age at the initiation of systemic therapy was 60 years (IQR, 29–88), 1,380 (78.4%) were men, and 1,341 (76.1%) underwent nephrectomy. Based on the International Metastatic Renal Cell Carcinoma Database Consortium model, patients were stratified into favorable-, intermediate-, and poor-risk groups with 359 (20.4%), 1,092 (62.0%), and 310 (17.6%) patients, respectively. The lung (70.9%), lymph nodes (37.9%), bone (30.7%), liver (12.7%), adrenal gland (9.8%), and brain (8.2%) were the most common sites of metastasis, followed by the pancreas, pleura, peritoneum, spleen, thyroid, and bowel. Among the most common sites of metastasis (> 5%), the median cancer-specific survival (CSS) ranged from 13.9 (liver) to 29.1 months (lung). An association was observed between liver, bone, and pleural metastases and the shortest median CSS (< 19 months). Conclusion: In Korean patients with mRCC, metastases to the lung, lymph nodes, bone, liver, adrenal gland, and brain were more frequent than those to other organs. Metastases to the liver, bone, and pleura were associated with poor CSS. The findings of this study may be valuable for patient counseling and guiding future study designs
Practice pattern of non‐muscle invasive bladder cancer in Japan, Korea and Taiwan: A Web‐based survey
No full textOBJECTIVES: To investigate the treatment pattern of non-muscle invasive bladder cancer patients among urologists in Japan, Korea and Taiwan, with emphasis on compliance with important treatment guidelines.
METHODS: A Web-based questionnaire survey was conceived by representative members of each country's urological oncology society and was open from June 2016 to February 2017 to each society's members. Descriptive statistics and multinomial logistic regression analysis were used.
RESULTS: A total of 2334 urologists were invited and 701 responded to the survey with a response rate of 30.0%. Instruments used during transurethral resection of bladder cancer varied significantly between countries and depended on their availability. The re-transurethral resection rate for pT1 or high-grade disease >50% of the time was significantly higher in Japan than in the other two countries, but the collective rate was just 49%. The frequency of intravesical therapy in intermediate- to high-risk disease was generally consistent across countries. However, the choice of agent between chemotherapy and bacillus Calmette-Guerin was significantly different between countries. Maintenance bacillus Calmette-Guerin was used <10% of the time by 45% of respondents, the most important reasons being fear of side-effects, followed by a lack of efficacy and shortage of drug supply.
CONCLUSIONS: There are significant differences between Japan, Korea and Taiwan in the management of intermediate- to high-risk non-muscle invasive bladder cancer. The results of this survey can serve as the basis for joint efforts to develop common clinical guidelines
Survival pattern of metastatic renal cell carcinoma patients according to WHO/ISUP grade: a long-term multi-institutional study
No full textThe World Health Organization/International Society of Urological Pathology (WHO/ISUP) grading of renal cell carcinoma (RCC) is classified from grade 1–4, regardless of subtype. The National Comprehensive Cancer Network (NCCN) guidelines (2022) state that if there is an adverse pathological feature, such as grade 3 or higher RCC in stage 1 patients, more rigorous follow-up imaging is recommended. However, the RCC guidelines do not provide specific treatment or follow-up policies by tumor grade. Therefore, this study attempted to find out whether tumor grade affects survival rates in patients with metastatic RCC. The Korean Renal Cancer Study Group (KRoCS) database includes 3108 patients diagnosed with metastatic RCC between September 1992 and February 2017, with treatment methods, progression, and survival data collected from 11 tertiary hospitals. To obtain information on survival rates or causes of death, we utilized the Korea National Statistical Office database and institutional medical records. Data were accessed for research purpose on June, 2023. We then reviewed these sources to gather comprehensive and reliable data on the outcomes of our study cohort. This database was retrospectively analyzed, and out of 3108 metastatic RCC patients, 911 had been identified as WHO/ISUP grade. Grades were classified into either a low-grade (WHO/ISUP grade 1–2) or a high-grade group (WHO/ISUP grade 3–4). The patients were then analyzed related to progression and overall survival (OS). In metastatic clear cell RCC patients, the 1-year OS rate was 69.4% and the median OS was 17.0 months (15.5–18.5) followed up to 203.6 months. When comparing the patient groups, 119 low-grade and 873 high-grade cases were identified. No baseline difference was observed between the two groups, except that the high-grade group had a higher ECOG 1 ratio of 50.4% compared with 34.5% for the low-grade group (p = 0.009). There was a significant difference in OS between high-grade and low-grade groups. OS was 16.0 months (14.6–17.4) in the high-grade group and 28.0 months (21.1–34.9) in the low-grade group (p < 0.001). However, there was no difference in progression-free survival (PFS) rates with 9.0 months (8.0–10.0) for the high-grade group and 10.0 months (6.8–13.2) for the low-grade group (p = 0.377) in first-line treatment. In multivariable analysis, WHO/ISUP grade was a risk factor (HR = 1.511[1.135–2.013], p = 0.005) that influenced the OS. In conclusion, WHO/ISUP grade is a major data source that can be used as a ubiquitous marker of metastatic RCC in pre-IO era. Depending on whether the RCC is high or low grade, the follow-up schedule will need to be tailored according to grade, with higher-grade patients needing more active treatment as it can not only affect the OS in the previously known localized/locoregional recurrence but also the metastatic RCC patient
Establishing consensus recommendations for metastatic hormone-sensitive prostate cancer in South Korea: A modified Delphi study
No full textPURPOSE: Consensus is lacking among South Korean urologists on the appropriate treatment of metastatic hormone-sensitive prostate cancer (mHSPC). A modified, Delphi-based consensus on managing mHSPC patients was developed to support clinical decision-making. MATERIALS AND METHODS: Thirty-six questions on mHSPC treatment were developed by an expert committee (five urologists). Nine questions required achievement of consensus (key questions). Twenty-three urologists participated in two rounds of a Delphi survey. Consensus was defined as >/=75% agreement among panelists, with >/=90% agreement representing strong consensus. RESULTS: Eighteen questions (50.0%) reached strong consensus, 15 (41.7%) reached consensus, and three (8.3%) reached no consensus. Eight key questions (88.9%) reached strong consensus and one (11.1%) reached consensus. Consensus was reached on recommending androgen-deprivation therapy (ADT) intensification, irrespective of disease volume or type, with an androgen receptor pathway inhibitor (ARPI) as the preferred option. Not using docetaxel alone with ADT when an ARPI is available for treatment intensification was recommended (strong consensus). For high-volume mHSPC patients with a pathogenic, speckle-type poxvirus and zinc finger protein mutation, ADT+ARPI was recommended over triplet therapy (strong consensus). Panelists recommended regular imaging every 6-12 months if no ARPI reimbursement restrictions exist, but a 3-month interval (per current reimbursement guidelines) otherwise. ADT+ARPI was the most recommended systemic treatment (strong consensus). CONCLUSIONS: This Delphi consensus established local consensus on controversial areas of mHSPC management. The findings offer meaningful perspectives that may help shape future treatment strategies and encourage thoughtful reconsideration of reimbursement criteria to align evidence and clinical practice in South Korea
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