Training ultrasound-guided percutaneous nephrostomy technique with porcine model.

PURPOSE: There is increasing interest in the use of ultrasound for endoscopic and percutaneous procedures. Access can be achieved without radiation exposure under ultrasound guidance. Our aim was to develop a porcine-based training model for ultrasound-guided percutaneous renal access that could also be personalized to a specific patient. MATERIALS AND METHODS: The Institutional Animal Care and Use Committee of Severance Hospital approved the study protocol. An anesthetized pig was placed in the dorsal lithotomy position. For the nephrostomy puncture, a Chiba biopsy needle with an echo tip was used under ultrasound guidance. Eight residents and three consultants in urology participated. Puncture time was defined as the nephrostomy time to confirm the flow of irrigation via the needle. After training, satisfaction survey results for clinical usability and procedural difficulty were evaluated. RESULTS: The 5-point Likert scale satisfaction survey for clinical usability and procedural difficulty found mean results of 4.64 and 4.09 points, respectively. There were no differences between residents and consultants for either variable. For all participants combined, there was a significant difference for nephrostomy time between the first and second trials (278.8±70.6 s vs. 244.5±47.0 s; p=0.007). The between-trial difference was greater for residents (291.5±71.2 s vs. 259.1±41.9 s; p=0.039). The difference for the consultant was not significant (245.0±69.4 s vs. 205.7±42.5 s; p=0.250). CONCLUSIONS: We developed a porcine-based ultrasound-guided nephrostomy puncture training model. Satisfaction survey results indicated high clinical usability and procedural difficulty. For nephrostomy time, the model was more effective for urology residents than for consultants.

Clinical Course and Mutational Analysis of Patients with Cystine Stone: A Single-Center Experience.

Cystinuria is a known genetic disorder. To date, two genes, SLC3A1 and SLC7A9, have been identified as causes of cystinuria. In this study of 10 patients with cystinuria, which is the largest Korean cohort ever studied, we examined the patients' phenotypes, clinical courses, and genetic analyses. A total of 10 patients with cystinuria diagnosed with cystine stones in a single tertiary medical center (Severance Hospital, Seoul, Republic of Korea) from April 2000 to July 2023 were included in the study. All of the patients participated in mutational studies, and the clinical presentation and consecutive laboratory findings of the patients were analyzed retrospectively. After the initial stone-related surgery or procedure at our hospital, 6 of the 10 patients underwent additional surgery at least once for recurrent stones. Genetic analyses identified six new mutations, of which only two patients had type B mutations. The most common genotype was compound heterozygous type A. We investigated the genotypes and clinical courses of 10 Korean patients with cystinuria who had not been previously reported. More data are needed to statistically analyze the genotype and phenotype of cystinuria.

Predicting Urinary Stone Composition in Single-Use Flexible Ureteroscopic Images with a Convolutional Neural Network.

Background and Objectives: Analysis of urine stone composition is one of the most important factors in urolithiasis treatment. This study investigated whether a convolutional neural network (CNN) can show decent results in predicting urinary stone composition even in single-use flexible ureterorenoscopic (fURS) images with relatively low resolution. Materials and Methods: This study retrospectively used surgical images from fURS lithotripsy performed by a single surgeon between January 2018 and December 2021. The ureterorenoscope was a single-use flexible ureteroscope (LithoVue, Boston Scientific). Among the images taken during surgery, a single image satisfying the inclusion and exclusion criteria was selected for each stone. Cases were divided into two groups according to whether they contained any calcium oxalate (the Calcium group) or none (the Non-calcium group). From 506 total cases, 207 stone surface images were finally included in the study. In the CNN model, the transfer learning method using Resnet-18 as a pre-trained model was used, and only endoscopic digital images and stone classification data were input to achieve minimally supervised learning. Results: There were 175 cases in the Calcium group and 32 in the Non-calcium group. After training and validation, the model was tested using the test set, and the total accuracy was 81.8%. Recall and precision of the test results were 88.2% and 88.2% in the Calcium group and 60.0% and 60.0% in the Non-calcium group, respectively. The area under the receiver operating characteristic curve of the model, which represents its classification performance, was 0.82. Conclusions: Single-use flexible ureteroscopes have financial benefits but low vision quality compared with reusable digital flexible ureteroscopes. As far as we know, this is the first artificial intelligence study using single-use fURS images. It is meaningful that the CNN performed well even under these difficult conditions because these results can further expand the possibilities of its use.

Impact of Preoperative Ureteral Stenting in Retrograde Intrarenal Surgery for Urolithiasis.

Background and Objectives: Ureteral stent insertion passively dilates the ureter. Therefore, it is sometimes used preoperatively before flexible ureterorenoscopy to make the ureter more accessible and facilitate urolithiasis passage, especially when ureteroscopic access has failed or when the ureter is expected to be tight. However, it may cause stent-related discomfort and complications. This study aimed to assess the effect of ureteral stenting prior to retrograde intrarenal surgery (RIRS). Materials and Methods: Data from patients who underwent unilateral RIRS for renal stone with the use of a ureteral access sheath from January 2016 to May 2019 were retrospectively analyzed. Patient characteristics, including age, sex, BMI, presence of hydronephrosis, and treated side, were recorded. Stone characteristics in terms of maximal stone length, modified Seoul National University Renal Stone Complexity score, and stone composition were evaluated. Surgical outcomes, including operative time, complication rate, and stone-free rate, were compared between two groups divided by whether preoperative stenting was performed. Results: Of the 260 patients enrolled in this study, 106 patients had no preoperative stenting (stentless group), and 154 patients had stenting (stenting group). Patient characteristics except for the presence of hydronephrosis and stone composition were not statistically different between the two groups. In surgical outcomes, the stone-free rate was not statistically different between the two groups (p = 0.901); however, the operation time for the stenting group was longer than that of the stentless group (44.8 ± 24.2 vs. 36.1 ± 17.6 min; p = 0.001). There were no differences in the complication rate between the two groups (p = 0.523). Conclusions: Among surgical outcomes for RIRS with a ureteral access sheath, preoperative ureteral stenting does not provide a significant advantage over non-stenting with respect to the stone-free rate and complication rate.

Comparison of Surgical Outcomes between Single-Use and Reusable Flexible Ureteroscopes for Renal Stone Management: A Systematic Review and Meta-Analysis.

Background and Objectives: Disposable flexible ureteroscopes have been widely used because of their cost-effectiveness and higher sterility potential compared with reusable flexible ureteroscopes. This study aimed to compare the surgical outcomes and complication rates in patients who undergo reusable or disposable flexible ureteroscopic stone surgeries (fURS) for urinary stone disease. Materials and Methods: A systematic review and meta-analysis were conducted under the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guideline. This systematic review was registered with PROSPERO (CRD42022331291). Clinical trials comparing reusable and disposable fURS for stone disease were found from PubMed, EMBASE, Cochrane Library, and the Web of Science up to March 2022. Participants were patients with upper urinary tract stones; the interventions were reusable or disposable fURS. Outcomes, including stone-free rate, operation time, length of hospital stay, and complication rate, were compared for analysis. Results: Overall, 111 studies were identified, but after removing duplicate studies, 75 studies remained. Thirty-two of these studies were excluded. Of the 43 screened studies, 11 met the eligibility criteria. There was no difference in the stone-free rate (SFR) between disposable and reusable fURS (p = 0.14; OR = 1.36; 95% CI, 0.9 to 2.04). For operation time, no difference was identified between reusable and disposable fURS groups (p = 0.12; MD = -5.31; 95% CI, -12.08 to 1.46). For hospital stay, there was also no difference between the two groups (p = 0.61; MD = -0.03; 95% CI, -0.17 to 0.10). There was no significant difference in complication rate between the two groups (p = 0.85; OR = 0.95; 95% CI, 0.56 to 1.61). Conclusions: There were no differences in the SFR, operation time, length of hospital stay, and complication rate between reusable and disposable fURS. Disposable fURS may be a comparable alternative to reusable fURS.

Establishment of patient-derived three-dimensional organoid culture in renal cell carcinoma.

Purpose: Renal cell carcinoma is a heterogeneous kidney cancer, and over 403,000 cases were reported worldwide in 2018. Current methods for studying renal cell carcinoma are limited to two-dimensional (2D) culture of primary cell lines and patient-derived xenograft models. Numerous studies have suggested that 2D culture poorly represents the diversity, heterogeneity, and drug-resistance of primary tumors. The time and cost associated with patient-derived xenograft models poses a realistic barrier to their clinical utility. As a biomimetic model, patient-derived three-dimensional (3D) organoid culture can overcome these disadvantages and bridge the gap between in vitro cell culture and in vivo patient-derived xenograft models. Here, we establish a patient-derived 3D organoid culture system for clear cell renal cell carcinoma and demonstrate the biomimetic characteristics of our model with respect to both primary kidney cancer and conventional 2D culture. Materials and Methods: Normal renal tissues and tumor tissues were collected from patients with clear cell renal cell carcinoma. The dissociated cells were cultured as conventional 2D culture and 3D organoid culture. The biomimetic characteristic of the two cultures were compared. Results: Compared with 2D culture, the 3D organoid cultures retained the characteristic lipid-rich, clear cell morphology of clear cell renal cell carcinoma. Carbonic anhydrase 9 and vimentin were validated as biomarkers of renal cell carcinoma. Expression of the two validated biomarkers was more enhanced in 3D organoid culture. Conclusions: Patient-derived 3D organoid culture retains the characteristics of renal cell carcinoma with respect to morphology and biomarker expression.

Protective role of hypoxia-inducible factor-1α-dependent CD39 and CD73 in fulminant acute liver failure.

Acute liver failure (ALF) is a severe life-threatening disease which usually arises in patients with-irreversible liver illnesses. Although human ectonucleotide triphosphate diphosphohydrolase-1, E-NTPDase1 (CD39) and ecto-5'-nucleotidase, Ecto5'NTase (CD73) are known to protect tissues from ALF, the expression and function of CD39 and CD73 during ALF are currently not fully investigated. We tested whether CD39 and CD73 are upregulated by hypoxia inducible factor (HIF)-1α, and improve ischemic tolerance to ALF. To test our hypothesis, liver biopsies were obtained and we found that CD39 and CD73 mRNA and proteins from human specimens were dramatically elevated in ALF. We investigated that induction of CD39 and CD73 in ALF-related with wild type mice. In contrast, deletion of cd39 and cd73 mice has severe ALF. In this study, we concluded that CD39 and CD73 are molecular targets for the development of drugs for ALF patients care.

Upregulation of P2Y2 nucleotide receptor in human hepatocellular carcinoma cells.

Objective To examine if hypoxia inducible factor-1α (HIF-1α) can induce the upregulation of the purinergic receptor P2Y2 (P2Y2) and thereby promote the viability of human hepatocellular carcinoma (HCC) cells under hypoxic conditions. Methods Archival HCC tumour specimens and corresponding non-cancerous tissues were examined immunohistochemically for P2Y2 protein. A series of in vitro experiments were undertaken using HCC cell lines to determine the effect of hypoxia on HIF-1α and P2Y2 levels, the effect of HIF-1α upregulation on P2Y2 levels, and the effect of P2Y2 upregulation on cell viability under hypoxic conditions. Results Human HCC specimens were positive for P2Y2. Hypoxia and upregulated HIF-1α both upregulated the P2Y2 levels in HCC cell lines. P2Y2 upregulation using plasmid transfection resulted in enhanced cell viability under hypoxia. Treatment of HepG2 cells with the selective P2Y2 antagonist MRS2312 downregulated P2Y2 and reduced cell viability in five HCC cell lines. P2Y2 knockdown reduced HepG2 cell viability under hypoxia. Conclusions These present results suggest that HCC cells upregulate P2Y2 levels during hypoxia, which in turn promotes their growth. P2Y2 could be a potential therapeutic target for treating HCC.

Epigallocatechin-3-gallate protects against hepatic ischaemia-reperfusion injury by reducing oxidative stress and apoptotic cell death.

Objective To investigate the protective effects of epigallocatechin-3-gallate (EGCG), a major polyphenol source in green tea, against hepatic ischaemia-reperfusion injury in mice. Methods The partial hepatic ischaemia-reperfusion injury model was created by employing the hanging-weight method in C57BL/6 male mice. EGCG (50 mg/kg) was administered via an intraperitoneal injection 45 min before performing the reperfusion. A number of markers of inflammation, oxidative stress, apoptosis and liver injury were measured after the ischaemia-reperfusion injury had been induced. Results The treatment groups were: sham-operated (Sham, n = 10), hepatic ischaemia-reperfusion injury (IR, n = 10), and EGCG with ischaemia-reperfusion injury (EGCG-treated IR, n = 10). Hepatic ischaemia-reperfusion injury increased the levels of biochemical and histological markers of liver injury, increased the levels of malondialdehyde, reduced the glutathione/oxidized glutathione ratio, increased the levels of oxidative stress and lipid peroxidation markers, decreased B-cell lymphoma 2 levels, and increased the levels of Bax, cytochrome c, cleaved caspase-3, and cleaved caspase-9. Pretreatment with EGCG ameliorated all of these changes. Conclusion The antioxidant and antiapoptotic effects of EGCG protected against hepatic ischaemia-reperfusion injury in mice.

Apoptosis of Hepatitis B Virus-expressing Liver Tumor Cells Induced by a High Concentration of Nucleos(t)ide Analogue.

BACKGROUND/AIM: We investigated the expression of hepatitis B virus (HBV) covalently closed circular DNA (cccDNA) and HBV X protein (HBx) in human hepatocellular carcinoma (HCC) and evaluated the effect of high-concentration nucleos(t)ide analogs (NUCs) on liver tumor cell lines. MATERIALS AND METHODS: This study consisted of three parts: part I used human blood and non-tumor liver tissues; part II used human HCC and adjacent liver tissues; and part III used an HBV-expressing liver tumor cell line. RESULTS: There were close correlations among blood and liver HBV DNA and liver cccDNA. HBV cccDNA and HBx were highly up-regulated in HCC compared to adjacent liver tissues despite NUC therapy. HBV cccDNA and HBx were highly up-regulated in the cccDNA-expressing HepG2.2.15 cell line. Their expression was down-regulated and apoptosis was induced by a very high concentration of NUCs in dose- and time-dependent manner. CONCLUSION: Very high concentrations of NUCs may have a novel potential to kill replicating HBV-expressing liver tumor cells.

Prognostic value of a 92-probe signature in breast cancer.

Clinical applications of gene expression signatures in breast cancer prognosis still remain limited due to poor predictive strength of single training datasets and appropriate invariable platforms. We proposed a gene expression signature by reducing baseline differences and analyzing common probes among three recent Affymetrix U133 plus 2 microarray data sets. Using a newly developed supervised method, a 92-probe signature found in this study was associated with overall survival. It was robustly validated in four independent data sets and then repeated on three subgroups by incorporating 17 breast cancer microarray datasets. The signature was an independent predictor of patients' survival in univariate analysis [(HR) 1.927, 95% CI (1.237-3.002); p < 0.01] as well as multivariate analysis after adjustment of clinical variables [(HR) 7.125, 95% CI (2.462-20.618); p < 0.001]. Consistent predictive performance was found in different multivariate models in increased patient population (p = 0.002). The survival signature predicted a late metastatic feature through 5-year disease free survival (p = 0.006). We identified subtypes within the lymph node positive (p < 0.001) and ER positive (p = 0.01) patients that best reflected the invasive breast cancer biology. In conclusion using the Common Probe Approach, we present a novel prognostic signature as a predictor in breast cancer late recurrences.

Predictive factors for invasive intraductal papillary mucinous neoplasm of the pancreas.

BACKGROUNDS/AIMS: Intraductal papillary mucinous neoplasm (IPMN) of the pancreas has malignant potential. Predicting invasive IPMN has proven difficult and controversial. We tried to identify predictive factors for invasive IPMN. METHODS: Thirty six patients underwent resection for IPMN from February 2001 to July 2011. Clinicopathological features including demographic, imaging, microscopic, and serological findings were retrospectively reviewed. Receiver operating characteristic (ROC) curve analysis was used to analyze sensitivity and specificity of all possible cut-off values for the diameter of the main pancreatic duct and mass size predicting invasive IPMN. Student t-test, chi-square test, and logistic regression were used for univariate and multivariate analysis. RESULTS: The mean age was 63.5±8.4 years. Males were more commonly affected (58.3% vs 41.7%). Pancreaticoduodenectomy was performed in 55.6% of patients, distal pancreatectomy in 36.1%, and central pancreatic resection in 8.3%. Non-invasive IPMNs were present in 80.6% (n=29), whereas invasive IPMNs were present in 19.4% (n=7). In univariate analysis, tumor location (p=0.036), Kuroda classification (p=0.048), mural nodule (p=0.016), and main duct dilatation (≥8 mm) (p=0.006) were statistically significant variables. ROC curve analysis showed that a value of 8 mm for the main duct dilatation and a value of 35 mm for the size of the mass lesion have 80% sensitivity and 75% specificity and 100% sensitivity and 82.6% specificity, respectively. However, in multivariate analysis, main ductal dilatation (≥8 mm) was identified to be the only independent factor for invasive IPMN (p=0.049). CONCLUSIONS: Main duct dilatation appears to be a useful indicator for predicting invasive IPMN.