Urolithiasis in Kidney Transplant Patients: A Multicenter KSER Research Series

Background and Objectives: Urolithiasis occurrence is uncommon in kidney transplantation patients, though it has serious implications, including acute kidney injury in the transplanted kidney. This study investigates the leading causes of urolithiasis in kidney transplantation patients, the diagnostic process, and the outcomes of multimodal management. Materials and Methods: Data collection spanned from January 1997 to December 2021, involving kidney transplantation patients with urolithiasis from the database of the Korean Society of Endourology and Robotics (KSER) research committee. Analysis encompassed factors triggering urolithiasis, the diagnostic process, stone attributes, treatment methods, and outcomes. Results: Our analysis included 58 kidney transplantation patients with urolithiasis from eight medical centers. Of these patients, 37 were male and 4 had previous urolithiasis diagnoses. The mean age was 59.09 ± 10.70 years, with a mean duration from kidney transplantation to diagnosis of 76.26 ± 183.14 months. The most frequent method of stone detection was through asymptomatic routine check-ups (54.7%). Among the 58 patients, 51 underwent stone treatment. Notably, 95.3% of patients with ureter stones received treatment, a significantly higher rate than the 66.7% of patients with renal stones (p = 0.010). Success rates showed no significant differences between renal (70%) and ureter stone (78.0%) groups (p = 0.881). Conclusions: Urolithiasis in transplanted kidneys constitutes an acute condition requiring emergency intervention. Endo-urological interventions are effective for kidney transplantation patients with urolithiasis. To ensure prevention and early detection, diligent follow-up and routine imaging tests are necessary.

Survey on disease insight and prevalence of urinary incontinence in women

Purpose

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

PURPOSE

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.

Cell membrane and nuclear expression of programmed death ligand-1 in prostate needle biopsy tissue in prostate cancer patients undergoing primary radiation therapy

BACKGROUND

Programmed death ligand-1 (PD-L1) expression in cancer is often associated with cancer aggressiveness and responsiveness to treatment with PD-1 pathway inhibitors. We conducted a systematic study on the expression of membranous PD-L1 (mPD-L1) and nuclear PD-1-L1 (nPD-L1) in prostate needle biopsy specimens of prostate cancer patients who underwent primary radiotherapy and analyzed the association between PD-L1 expression and clinicopathological characteristics and prognosis of patients.

METHOD

A total of 971 cancer-containing prostate needle biopsy cores from 172 patients were immunohistochemically stained with anti-PD-L1 antibody. The association of PD-L1 expression with Gleason score and tumor volume percentage was evaluated for each biopsy core. Total of 171 patients were divided according to mPD-L1 or nPD-L1 expression, and clinicopathological characteristics were compared between the positive and negative groups. The prognostic significance of mPD-L1, nPD-L1 and common prognostic factors were analyzed in terms of biochemical recurrence.

RESULT

Total of 15% and 46% of biopsy cores were stained positive for mPD-L1 and nPD-L1, respectively. There was a positive correlation between Gleason score and mPD-L1 and a negative correlation between Gleason score and nPD-L1. Between mPD-L1 and nPD-L1, there was no significant correlation. There was intraindividual heterogeneity in PD-L1 expression among different Gleason scores. For mPD-L1, only pretreatment PSA was significantly higher in the positive group than in the negative, but not Gleason score and T stage. For nPD-L1, Gleason score and T stage were significantly higher in the positive group than in the negative. Both mPD-L1 and nPD-L1 expression were not predictive of BCR-free survival in univariate and multivariate analyses.

CONCLUSIONS

Our results suggest that PD-1 pathway inhibitor may be a potential therapeutic option in high risk prostate cancer patients as early as neoadjuvant setting. The novel discovery of PD-L1 expression in the nucleus of PC should be subjected to further research.

Postoperative membranous urethral length is the single most important surgical factor predicting recovery of postoperative urinary continence

PURPOSE

To analyze the potential surgical factors affecting postoperative urinary continence, including postoperative membranous urethral length (MUL), in an era where open radical prostatectomy (ORP) and robot-assisted radical prostatectomy (RARP) coexist.

METHODS

Consecutive patients undergoing either ORP or RARP between April 2009 and June 2017 were included in this study. Pericatheter urethrography (PCU) was performed the day of catheter removal to confirm healing of the vesicourethral anastomosis and to measure PCU-MUL. Daily usage of incontinence pad was self-reported by the patient at each post-operative visit through a questionnaire. Univariate and multivariate analyses were performed to identify factors that influenced recovery of continence.

RESULTS

Of the 196 patients included, 121 and 75 patients received ORP and RARP, respectively. The cumulative full continence rates (0 pad/day) at 1 year in the ORP and RARP groups were 87% and 95%, respectively. In the univariate analysis, older age, high preoperative International Prostate Symptom Score (IPSS) irritative symptom domain, ORP, poorer NVB preservation, and shorter PCU-MUL were associated with delayed recovery of full continence. In the multivariate analysis, only older age, high preoperative IPSS irritative symptom domain, and shorter PCU-MUL remained as independent factors significantly associated with delayed recovery of full continence.

CONCLUSIONS

Our study highlights the importance of saving the MUL as long as possible in terms of continence recovery. This holds true for ORP even in the era of RARP and surgeons should not simply give up the prospect of early urinary continence in exchange for the patient's choice of ORP instead of RARP.

Prognostic significance of preoperative and follow-up neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio in patients with non-metastatic clear cell renal cell carcinoma

Purpose

To evaluate the significance of preoperative and follow-up neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) as prognostic factors for recurrence in patients with non-metastatic clear cell renal cell carcinoma (NMCCRCC).

Materials and Methods

We retrospectively reviewed the medical records of 309 patients with NMCCRCC who underwent radical or partial nephrectomy. The prognostic significance of various clinicopathological variables, preoperative NLR (pNLR) and PLR (pPLR), and NLR and PLR at recurrence or quasi-recurrence (rNLR and rPLR) for recurrence-free survival (RFS) was analyzed.

Results

At mean follow-up of 93 months, 44 patients (14.2%) developed recurrence. In the univariate analysis, clinical presentation, tumor size, pathologic tumor stage, Fuhrman grade, pNLR, pPLR and rNLR were significant prognostic factors for RFS. In the multivariate analysis using pNLR and pPLR as continuous variables, tumor size, pathologic tumor stage and pPLR were independent prognostic factors for RFS. In the multivariate analysis using pNLR and pPLR as dichotomous variables, tumor size, pathologic tumor stage, Fuhrman grade and pNLR ≥1.7 were independent prognostic factors for RFS. In multivariate analyses using rNLR and rPLR, only tumor size and pathologic tumor stage were independent prognostic factors for RFS. In a subset of patients with recurrence or at least 42 months follow-up without recurrence, rNLR ≥1.9 was significantly associated with worse RFS, albeit without independent significance.

Conclusions

pNLR and pPLR are independent prognostic factors for RFS in patients with NMCCRCC. We propose that postoperative follow-up NLR of 1.9 and higher with one or more adverse clinicopathological factors should prompt radiologic evaluation for possible metastasis.

Long-term cost comparison between surgical and medical therapy for benign prostatic hyperplasia: a study using hospital billing data

OBJECTIVES

To analyse actual long-term medical treatment of benign prostatic hyperplasia (BPH) and compare the incurred cost with that of patients with BPH who underwent early surgery.

PATIENTS AND METHODS

Patients who were first diagnosed with BPH from 1 January 2008 to 31 December 2010 were identified using the Clinical Data Warehouse. Hospital billing data generated by the electronic hospital management system were collected until December 2015. For outpatient care, only procedures, materials and drugs directly related to the management of BPH were selected for the analysis. For inpatient care, all procedures, materials and drugs ordered on dates with continuity with BPH surgery date were included. The primary endpoint of the study was the total treatment-related direct costs of patients undergoing a long-term curative medical therapy for BPH (Group 1), which was arbitrarily defined as any medical therapy including a 5α-reductase inhibitor with a minimum medication possession ratio of 0.5 during ≥5 consecutive years, or ≥1 year until BPH surgery due to medical therapy failure. In all, 70 patients who underwent BPH surgery at <1 year of initial visit served as controls (Group 2).

RESULTS

Amongst 137 patients in the Group 1, four patients underwent BPH surgery at a median of 57.8 months after the initial visit (2.9%). At a median follow-up of 76 months, the mean total treatment cost was significantly higher in Group 1 than in Group 2 ($3987 vs $3036 [USA dollars], P < 0.001). Similarly, the mean 'out-of-pocket' cost was significantly higher in Group 1 than in Group 2 ($1742 vs $1436, P = 0.005). When a linear increment of annual BPH treatment cost is assumed for Group 1 and all costs are assumed to be produced within the first year for Group 2, the total and out-of-pocket costs became equal at the end of the fifth year of medical treatment. For both total and out-of-pocket costs, medication-related costs occupied the largest proportion, exceeding half of the costs.

CONCLUSIONS

We suggest patient counselling at the beginning of BPH treatment should include the likelihood that the cumulative out-of-pocket cost at 5 years of continuous medication will exceed that of early surgery. Our cost study using hospital billing data extractable from the electronic hospital management system may be a good model for cost studies that could provide valuable information to health providers and payers.

Changes in autonomic nervous system activity after treatment with alpha-blocker in men with lower urinary tract symptoms

Purpose

To determine changes in autonomic nervous system activity after treatment in men with lower urinary tract symptoms (LUTS), we evaluated changes in patients' symptoms, uroflowmetry, and heart rate variability (HRV) after treatment with alpha-blockers for 12 weeks.

Materials and Methods

Ninety-five men who had LUTS (International Prostate Symptom Score [IPSS] ≥8) were included in this study. We divided them into two groups on the basis of a low frequency/high frequency (LF/HF) ratio of 1.6. After treatment with Xatral XL (Handok Inc., Korea) 10 mg for 3 months, we rechecked their IPSS, uroflowmetry, HRV and compared these with the baseline measurements.

Results

Fifty-four men were assigned to the low LF/HF group (group A: LF/HF ≤1.6) and 41 men to the high LF/HF group (group B: LF/HF >1.6). At baseline and 12 weeks, none of the parameters differed significantly between the groups except for HF, which is one of the parameters of HRV. IPSS, the IPSS-voiding subscore, and the IPSS-storage subscore decreased and maximal uroflow increased significantly after 12 weeks of treatment. Whereas the baseline LF/HF ratio increased from 0.89±0.407 to 1.80±1.804 after treatment in group A, it decreased from 3.93±5.471 to 1.79±1.153 in group B.

Conclusions

The efficacies of Xatral XL were clear in both groups. We found that the LF/HF ratio in the two groups merged to a value of approximately 1.79 after treatment. We suggest that this could be a clue to the importance of balance in autonomic nervous system activity in men with LUTS.

Inhibition of tyrosinase by green tea components

The pigment melanin in human skin is a major defense mechanism against ultraviolet light of the sun, but darkened skin color, which is the result of increased and redistributed epidermal melanin, could be a serious aesthetic problem. Epidemiologically, it is well known that the consumption of green tea may help prevent cancers in humans and also reduce several free radicals including peroxynitrite. In the present study, to assess the efficacy of the inhibition of mushroom tyrosinase (monophenol monooxygenase EC 1.14.18.1), ten kinds of Korean traditional teas were screened for their tyrosinase inhibitory activity. Green tea was the strongest inhibitor, and the major active constituents in the tea are (-)-epicatechin 3-O-gallate (ECG), (-)-gallocatechin 3-O-gallate (GCG), and (-)-epigallocatechin 3-O-gallate (EGCG). All are catechins with gallic acid group as an active site. The kinetic analysis for inhibition of tyrosinase revealed a competitive nature of GCG with this enzyme for the L-tyrosine binding at the active site of tyrosinase.

Dietary modulation of prostanoid synthesis in the aging process: role of cyclooxygenase-2

To investigate the role of cyclooxygenase (COX) as a mediator for prostaglandin synthesis in relation to generation of reactive oxidant species (ROS), we quantitated the COX-derived ROS generation and the gene expression of COX-2, an inducible form of COX in aged kidney. In addition, the modulation by dietary restriction was investigated. COX-derived ROS generation increased with age in ad libitum (AL) rats, but dietary restriction (DR) suppressed the level. The amounts of COX-2 protein and mRNA increased with age in AL rats but maintained at low levels in DR group. It was found that the binding characteristics of a nuclear transcription factor, NF-kappaB were altered by aging. The binding activity of NF-kappaB in aged kidney was significantly enhanced with the corresponding increase in mRNA and protein levels. These increases were closely in parallel to the increased ROS generation and gene expression of COX-2. The COX activity shown by NF-kappaB activation and the ROS generation by COX-mediated process were all modulated by DR. Our results suggest that the upregulation of COX-2 during aging may play an important role in many age-related diseases associated with aging process. And this upregulation was attenuated by DR. We propose that the modulation of the redox-sensitive transcription factor may well be a part of the mechanisms underpinning the anti-oxidative action of DR.

Xanthine dehydrogenase/xanthine oxidase and oxidative stress

Xanthine dehydrogenase (XDH) and xanthine oxidase (XOD) are single-gene products that exist in separate but interconvertible forms. XOD utilizes hypoxanthine or xanthine as a substrate and O2 as a cofactor to produce superoxide (·O2 (-)) and uric acid. XDH acts on these same substrates but utilizes NAD as a cofactor to produce NADH instead of ·O2 (-) and uric acid. XOD has been proposed as a source of oxygen radicals in polymorphonuclear, endothelial, epithelial, and connective tissue cells. However, several questions remain about the physiological significance and functions of XOD on aging and oxidative stress. XOD is reported to play an important role in cellular oxidative status, detoxification of aldehydes, oxidative injury in ischemia-reperfusion, and neutrophil mediation. For example, XOD may serve as a messenger or mediator in the activation of neutrophil, T cell, cytokines, or transcription in defense mechanisms rather than as a free radical generator of tissue damage. Emerging evidence on the synergistic interactions of ·O2 (-), a toxic product of XOD and nitric oxide, may be another illustration of XOD involvement in tissue injury and cytotoxicity in an emergent condition such as ischemia or inflammation.

An ankyrin-related gene (unc-44) is necessary for proper axonal guidance in Caenorhabditis elegans

Caenorhabditis elegans unc-44 mutations result in aberrant axon guidance and fasciculation with inappropriate partners. The unc-44 gene was cloned by transposon tagging, and verified by genetic and molecular analyses of six transposon-induced alleles and their revertants. Nucleotide sequence analyses demonstrated that unc-44 encodes a series of putative ankyrin-related proteins, including AO49 ankyrin (1815 aa, 198.8 kD), AO66 ankyrin (1867 aa, 204 kD), and AO13 ankyrin (< or = 4700 aa, < or = 517 kD). In addition to the major set of approximately 6 kb alternatively spliced transcripts, minor transcripts were observed at approximately 3, 5, 7, and 14 kb. Evidence is provided that mutations in the approximately 14-kb AO13 ankyrin transcript are responsible for the neuronal defects. These molecular studies provide the first evidence that ankyrin-related molecules are required for axonal guidance.