Label-free detection of kidney stones urine combined with SERS and multivariate statistical algorithm.

Kidney stones are a common urological disease with an increasing incidence worldwide. Traditional diagnostic methods for kidney stones are relatively complex and time-consuming, thus necessitating the development of a quicker and simpler diagnostic approach. This study investigates the clinical screening of kidney stones using Surface-Enhanced Raman Scattering (SERS) technology combined with multivariate statistical algorithms, comparing the classification performance of three algorithms (PCA-LDA, PCA-LR, PCA-SVM). Urine samples from 32 kidney stone patients, 30 patients with other urinary stones, and 36 healthy individuals were analyzed. SERS spectra data were collected in the range of 450-1800 cm-1 and analyzed. The results showed that the PCA-SVM algorithm had the highest classification accuracy, with 92.9 % for distinguishing kidney stone patients from healthy individuals and 92 % for distinguishing kidney stone patients from those with other urinary stones. In comparison, the classification accuracy of PCA-LR and PCA-LDA was slightly lower. The findings indicate that SERS combined with PCA-SVM demonstrates excellent performance in the clinical screening of kidney stones and has potential for practical clinical application. Future research can further optimize SERS technology and algorithms to enhance their stability and accuracy, and expand the sample size to verify their applicability across different populations. Overall, this study provides a new method for the rapid diagnosis of kidney stones, which is expected to play an important role in clinical diagnostics.

Retroperitoneal vs transperitoneal laparoscopic pyelolithotomy; a single surgeon's experience.

OBJECTIVE: To compare the outcomes of transperitoneal and retroperitoneal laparoscopic pyelolithotomy procedures. METHODS: A total of 104 consecutive laparoscopic pyelolithotomy surgeries performed by a single surgeon on patients with staghorn or renal pelvic calculi larger than 20 mm were evaluated. Intraoperative and postoperative clinical parameters from two groups, transperitoneal (TLPL) (N = 55) and retroperitoneal (RLPL) (N = 49), were compared. The surgeon performed TLPL for the first five years and then switched to the RLPL approach for the next five years. RESULTS: There were no significant differences in general demographic variables and stone size (26.55 vs. 24.73 mm, P = 0.8). Operation time and change in serum creatinine levels did not significantly differ between the two approaches. However, patients who underwent TLPL had longer hospital stays than RLPL (3.23 ± 1.21 vs. 2.36 ± 1.10 days, P = 0.0001). Additionally, TLPL was associated with a greater drop in hemoglobin levels (1.53 ± 1.04 vs. 1.17 ± 0.68, P = 0.04), higher rates of postoperative fever (12.7% vs. 0.0%, P = 0.01). CONCLUSIONS: The retroperitoneal approach in laparoscopic pyelolithotomy for large renal pelvic stones resulted in fewer postoperative fevers, reduced hemoglobin drops, and shorter hospital stays than the transperitoneal approach. However, the stone-free rates were similar for both groups.

Identifying effects of volatile organic compounds exposure on kidney stone prevalence in U.S. adults: a cross-sectional analysis of NHANES 2007-2020.

OBJECTIVE: Our aim was to comprehensively investigate the relationship between blood volatile organic compounds (VOCs) and kidney stone prevalence for U.S. adults. METHODS: In this cross-sectional study, 10,052 participants from the 2007-2020 National Health and Nutrition Examination Survey (NHANES) were included. Multivariate logistic regression model was employed to investigate the association between 9 blood VOCs and kidney stones. We explored the dose-response relationship between blood VOCs and kidney stones using restricted cubic spline (RCS) analysis. Additionally, weighted quantile sum (WQS) regression model was performed to assess the overall association of 9 blood VOCs with kidney stones. Finally, subgroup analyses were conducted to identify the findings in different populations at high prevalence. RESULTS: Logistic regression analysis and dose-response risk curves revealed that blood benzene (aOR = 1.308, 95% CI: 1.118-1.530, P = 0.001), blood ethylbenzene (aOR = 1.280, 95% CI: 1.054-1.554, P = 0.013), blood m-/p-xylene (aOR = 1.187, 95% CI: 1.008-1.398, P = 0.040), blood 2,5-dimethylfuran (aOR = 1.319, 95% CI: 1.135-1.533, P < 0.001) and blood furan (aOR = 1.698, 95% CI: 1.305-2.209, P < 0.001) were positively associated with the prevalence of kidney stones. WQS regression analysis revealed that exposure to mixed blood VOCs was positively correlated with kidney stone prevalence (OR = 1.34, 95% CI: 1.14-1.57), with furans carrying the greatest weight. Subgroup analyses suggested that kidney stones were more susceptible to the effects of blood VOCs in young and middle-aged, female, overweight and obese, non-hypertensive, and non-diabetic populations. CONCLUSIONS: In this study, the results indicated that high VOC exposure was positively and independently associated with kidney stones in U.S. adults. This finding highlighted the need for public health strategies to reduce VOC exposure and its role in kidney stone prevention and treatment.

Visually navigated, ultrasound-guided, freehand percutaneous calyceal puncture - preclinical evaluation of a novel device to simplify a complex surgical task.

Purpose Freehand sonographic percutaneous puncture techniques for the renal calyceal system are on the rise. Much time and practice are required to master this technique. Navigation-supported puncture aids could help make percutaneous access easier and faster. The aim of this study was to determine whether navigated puncture is feasible, and whether it is easier and faster compared to the conventional sonographic procedure. Materials & Methods We performed prospective free-hand percutaneous puncture on a porcine kidney model embedded in gelatin using the Xperius ultrasound system in combination with needle tracking with a Stimuplex Onvision hollow needle, compared to the conventional freehand ultrasound puncture technique. Punctures were performed by 25 participants using the ultrasound machine with or without needle tracking mode. Results Compared to the conventional approach, the navigated approach reduced the number of puncture procedures by 0.2 attempts(8%) in the experienced group. The time to calyx access was reduced by 15 seconds (26%). In the novice group, navigated puncture required 1.2 fewer attempts (36%) and the time to access was 70 seconds faster (61%). Conclusion Puncture using the novel device is feasible. The number of punctures and the time needed for successful access of the calyceal system was reduced by use of navigation in both groups, although the trend was significant only in the novice group. Navigation using needle tracking seems to help beginners perform sonographic percutaneous puncture at a level similar to experienced users. For a more precise analysis and validation, further studies are needed.

Predictors of follow-up of pediatric stone patients after surgical intervention.

OBJECTIVE: We investigated if socioeconomic and demographic factors predict post-surgical follow-up in pediatric stone patients. MATERIALS AND METHODS: All patients having kidney stone surgery at a single academic pediatric hospital over a 5 year period (2016-2020) were identified through the use of CPT® codes specific to ureteroscopy, shock wave lithotripsy, and percutaneous nephrolithotomy. Electronic charts were reviewed for patient demographics, stone characteristics, and characteristics of intervention. Unique patients with a scheduled post-operative follow-up office visit following a first time stone surgery were included in the patient cohort (Figure 1). Primary outcome was attendance of a scheduled provider visit within 6 months after surgery. Secondary outcomes included completion of scheduled post-operative imaging and 24-h urine study. Univariable analysis was performed. RESULTS: 195 pediatric patients, a median age of 15.4 years (IQR: 11.34, 17.14) at surgery, were identified. The majority were non-Hispanic white (86.2%) and female (62.1%). Most had undergone ureteroscopy alone (85.6%). Of the 195 patients, 146 (74.9%) attended a post-operative office visit. Indicators of lower socioeconomic status, such as having public insurance and being from a single-parent home, were associated with not attending a scheduled follow-up visit (p < 0.01 and p = 0.02, respectively). Patients with a pre-operative urology clinic visit were more likely to follow-up with a clinic visit (p = 0.02), while those with a larger total stone burden treated were more likely to undergo ordered imaging (p < 0.01). DISCUSSION: We found that indicators of lower socioeconomic status, such as having public insurance status and being in a single-parent household, were associated with lower pediatric follow-up compliance after kidney stone surgery, while patients seen in the urology clinic preoperatively were more likely to attend follow-up. CONCLUSION: Identifying factors that may predict non-compliance could be used to help at-risk patient populations.

SGLT2 Inhibitors and Their Effect on Urolithiasis: Current Evidence and Future Directions.

Urolithiasis (UL) is increasingly prevalent due to rising cardiorenometabolic diseases, posing significant management challenges despite advances in urological techniques. Sodium-glucose cotransporter-2 (SGLT2) inhibitors, primarily used for type 2 diabetes mellitus, chronic kidney disease, and heart failure, have emerged as a potential novel approach for UL treatment. These inhibitors may help reduce the risk of urolithiasis, particularly in patients with diabetes, by improving glycemic control and altering urinary chemistry, which are crucial factors in stone formation. However, the changes in urinary composition induced by SGLT2 inhibitors might also increase the risk of uric acid stone formation. This review evaluates the potential of SGLT2 inhibitors in managing UL, highlighting both the benefits and the risks. While these inhibitors show promise in reducing new and recurrent urinary stones in patients with diabetes, data on their effects in patients without diabetes who form stones are limited. Current human evidence largely comes from post hoc analyses of randomized controlled trials (RCTs) and large-scale database studies, with only one study providing detailed stone composition data. Experimental studies in animal models and cell lines have focused on calcium oxalate (CaOx) stones, showing that SGLT2 inhibitors specifically target CaOx stone formation and related renal inflammation. Although primarily studied for CaOx stones, their potential impact on other calcium-containing stones, such as calcium phosphate, remains promising. Further research is needed to explore their therapeutic potential and optimize treatment strategies.

Automatic kidney stone identification: an adaptive feature-weighted LSTM model based on urine and blood routine analysis.

Kidney stones are the most common urinary system diseases, and early identification is of great significance. The purpose of this study was to use routine urine and blood detection indices to build a deep learning (DL) model to identify the presence of kidney stones in the early stage. A retrospective analysis was conducted on patients with kidney stones who were treated at West China Hospital of Sichuan University from January 2020 to June 2023. A total of 1130 individuals presenting with kidney stones and 1230 healthy subjects were enrolled. The first blood and urine laboratory data of participants at our hospital were collected, and the data were divided into a training dataset (80%) and a verification dataset (20%). Additionally, a long short-term memory (LSTM)-based adaptive feature weighting model was trained for the early identification of kidney stones, and the results were compared with those of other models. The performance of the model was evaluated by the area under the subject working characteristic curve (AUC). The important predictive factors are determined by ranking the characteristic importance of the predictive factors. A total of 17 variables were screened; among the top 4 characteristics according to the weight coefficient in this model, urine WBC, urine occult blood, qualitative urinary protein, and microcyte percentage had high predictive value for kidney stones in patients. The accuracy of the kidney stone (KS-LSTM) learning model was 89.5%, and the AUC was 0.95. Compared with other models, it has better performance. The results show that the KS-LSTM model based on routine urine and blood tests can accurately identify the presence of kidney stones. And provide valuable assistance for clinicians to identify kidney stones in the early stage.

In the Treatment of Lower Pole Kidney Stones Between 1-2 cm in Children, Which is the Best Approach? Retrograde Intrarenal Surgery or Mini Percutaneous Nephrolithotomy.

Objectives: Kidney stones are treated with many methods, but there is no consensus on which method should be preferred for 1-2 cm lower renal stones. In our study, we aimed to investigate the results of mini (Percutaneous Nephrolithotomy) PCNL and (Retrograde Intrarenal Surgery) RIRS in lower renal pole 1-2 cm stones. Methods: Twenty-four mini PCNL and 55 RIRS patients were included in the study. Demographic data of the patients and information about stones on Non-Computed Tomography (NCCT) were recorded. Stone-free status (SFR), need for additional treatment and complications of both methods were compared. Results: Operative time was 55.2±20.8 min in mini PCNL and 70.7±36.5 min in RIRS, which was statistically significantly lower (p=0.002). Length of hospital stay was 2.4±1.5 days in the mini PCNL and 1.3±0.7 days in the RIRS, which was statistically significantly longer (p=0.011). In the postoperative 1st month and 3rd month stone-free rates (SFR) were higher in the mini PCNL group. While the 1st month SFR was 91.6% and 54.5%, the 3rd month stone-free rates were 95.8% vs. 69.1%, respectively (p<0.001). The need for re-treatment was statistically lower in the mini PCNL group (p<0.001). In terms of complications, the incidence of complications was 16.6% (pain in 2 patients, fever in 1 patient, need for blood transfusion in 1 patient) in the mini PCNL group and 21.8% (pain in 2 patients, fever in 8 patients, sepsis in 2 patients) in the RIRS group. There was a significant difference between the two groups (p=0.008). Conclusion: Mini PCNL has a higher SFR, less need for re-treatment and fewer complications.

Association between insulin resistance indices and kidney stones: results from the 2015-2018 National Health and Nutrition Examination Survey.

Objective: To explore the association between representative insulin resistance (IR) indices and the risk of kidney stone disease in an American adult population. The representative IR indices referred to metabolic score for IR (METS-IR), triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio, triglyceride glucose-body mass index (TyG-BMI), visceral adiposity index (VAI), and homeostatic model assessment of IR (HOMA-IR). Methods: We investigated adult participants who joined the 2015-2018 National Health and Nutrition Examination Survey (NHANES) and reported kidney stone histories. Weighted proportions, multivariable regression analysis, and restricted cubic splines were used to evaluate the associations between IR indices and kidney stones after their adjustment for gender, age, race, education, smoking status, alcohol drinking frequency, hypertension and diabetes status, physical activity level, water intake, and levels of calcium, cholesterol, and uric acid. Results: A total of 19,225 participants were included. The weighted prevalence of kidney stone was 11.1%. A multivariable logistic regression model showed a dose-response relationship between the METS-IR and kidney stone [odds ratio (OR) = 1.02, 95% confidence interval (CI) (1.01, 1.04), p < 0.01]. A similar relationship was observed between the TyG-BMI and kidney stone after full adjustment [OR = 1.0, 95% CI (1.0, 1.01), p < 0.001]. Sex-stratified analyses revealed that the association between METS-IR and nephrolithiasis [OR = 1.03, 95% CI (1.01, 1.05), p < 0.01], and the association between TyG-BMI and nephrolithiasis [OR = 1.01, 95% CI (1.0, 1.01), p <0.001] was significant among the male participants in the fully adjusted model. Moreover, a significant association was found between the METS-IR levels and nephrolithiasis [OR = 1.03, 95% CI (1.01, 1.06), p < 0.01], and between the TyG-BMI levels and nephrolithiasis [OR = 1.01, 95% CI (1.0, 1.01), p < 0.05] among the diabetic participants after full adjustment. Furthermore, a potential nonlinear association was found between other IR indices (i.e., TG/HDL-C, VAI, and HOMA-IR) and the risk of kidney stone disease. Conclusion: Higher METS-IR and TyG-BMI levels were associated with a higher risk of nephrolithiasis. Future investigations are required to identify the role of IR in the progress of kidney stone formation and to propose prevention measures and health guidelines.

Efficacy and Safety of Boldine Combined with Phyllanthus niruri and Ononis spinosa in Medical Expulsive Therapy for Distal Ureteral Stones with Renal Colic: A Single-Center, Retrospective Cohort Study.

Background and Objectives: This study aimed to compare the effects and safety of boldine combined with Phyllanthus niruri and Ononis spinosa plus tamsulosin vs. tamsulosin alone in medical expulsive therapy (MET) for distal ureteral calculi. Materials and Methods: This retrospective cohort study was conducted on 159 renal colic patients with distal ureteric stones (≤10 mm). Patients aged between 18 and 70 years or older with distal ureteral (below the sacroiliac joint) stones ≤10 mm (defined by the largest diameter in three planes) confirmed by urinary ultrasonography and/or native computed tomography (CT). Patients were divided into two groups: A and B. Patients in Group A received tamsulosin 0.4 mg plus boldine combined with Phyllanthus niruri and Ononis spinosa, while those in Group B received tamsulosin 0.4 mg. The rate of stone expulsion, duration of stone expulsion, the dose and the duration of nonsteroidal anti-inflammatory drugs (NSAIDs), analgesic use, and adverse effects of drugs were recorded. Results: No differences were reported in demographic profiles between the two groups. The stone expulsion rate in Group A (84.8%) was higher in comparison to Group B (52.5%); the mean time of stone expulsion was 16.33 ± 4.75 days in Group A and 19.33 ± 6.42 days in Group B. The mean requirement time of analgesia was significantly less in Group A, 2.42 ± 2.56, than in Group B, 6.25 ± 3.05. Drug-related adverse effects (headache, dizziness, nausea, vomiting, postural hypotension, backache, and running nose) were comparable between the two groups. Conclusions: Tamsulosin plus boldine combined with Phyllanthus niruri and Ononis spinosa as medical expulsion therapy is more effective for distal ureteric stones with less need for analgesics and a shorter stone expulsion time than tamsulosin alone.

The Role of the Gut Microbiome in Kidney Stone Disease.

Microbiome dysbiosis is closely related to the etiology of kidney stone disease (KSD) and influences a multitude of pathways. Due to our knowledge gaps on this topic, it is still unclear if microbiome interventions can be translated to demonstrate clinical efficacy. Current evidence suggests that the enhancement of butyrate-producing pathways should be the next step for KSD research. While we are not yet at a point where we can make clinical recommendations for KSD, there are many simple dietary or supplement-based approaches that could be applied in the future for prophylaxis or treatment of KSD.

Alcohol Intake and Prevalent Kidney Stone: The National Health and Nutrition Examination Survey 2007-2018.

The association of alcohol intake with kidney stone disease (KSD) is not clear based on current clinical evidence. We examined the National Health and Nutrition Examination Survey (NHANES) 2007-2018 and used logistic regression analyses to determine the independent association between alcohol intake and prevalent KSD. In total, 29,684 participants were eligible for the final analysis, including 2840 prevalent stone formers (SFs). The mean alcohol intake was 37.0 ± 2.4 g/day among SFs compared to 42.7 ± 0.9 among non-SFs (p = 0.04). Beer [odds ratio (OR) = 0.76, 95% CI: 0.61-0.94, p = 0.01] and wine (OR = 0.75, 95% CI: 0.59-0.96, p = 0.03) intakes were strongly associated with lower odds of prevalent KSD, while liquor intake had no association. Furthermore, the effects of beer and wine intakes on stone formation were dose-dependent. The OR for comparing participants drinking 1-14 g/day of beer to non-drinkers was 1.41 (95%CI: 0.97-2.05, p = 0.07), that of >14-≤28 g/day of beer to non-drinkers was 0.65 (95% CI: 0.42-1.00, p = 0.05), that of >28-≤56 g/day of beer to non-drinkers was 0.60 (95% CI: 0.39-0.93, p = 0.02), and that of >56 g/day of beer to non-drinkers was 0.34 (95% CI: 0.20-0.57, p < 0.001). Interestingly, the effect of wine intake was only significant among participants drinking moderate amounts (>14-28 g/day), with an OR of 0.54 (95% CI: 0.36-0.81, p = 0.003) compared to non-drinkers, but this effect was lost when comparing low-level (1-14 g/day) and heavy (>28 g/day) wine drinkers to non-drinkers. These effects were consistent in spline models. This study suggests that both moderate to heavy beer intake and moderate wine intake are associated with a reduced risk of KSD. Future prospective studies are needed to clarify the causal relationship.

A Patient-Prioritized Research Agenda for Clinical Trials in Kidney Stone Disease.

PURPOSE: To ensure that research on kidney stones provides meaningful impact for the kidney stone community, patients and caregivers should be engaged as stakeholders in clinical trial design, starting at study inception. This project aimed to elicit, refine, and prioritize research ideas from kidney stone stakeholders to develop a patient-centered research agenda for clinical trials. MATERIALS AND METHODS: The Kidney Stone Engagement Core, a group of patients, caregivers, advocates, clinicians, and researchers, executed an iterative process of surveys and focus groups to elicit and refine research themes, which were then translated into research questions. A separate group of patients, caregivers, and clinicians prioritized these questions through parallel modified Delphi and crowd-sourced digital platforms. A research agenda was developed by the Kidney Stone Engagement Core based on the highest rated questions during a hybrid virtual/in-person capstone session. RESULTS: A total of 70 individuals (57 patients and caregivers, 13 researchers and clinicians) participated in the elicitation, 20 individuals (15 patients and caregivers, 5 researchers and clinicians) participated in refinement, and an additional 80 individuals (81 patients and caregivers, 9 researchers and clinicians) participated in prioritization. Key novel themes emerged from elicitation and refinement: ureteral stents, genetic evaluation, shared surgical decision-making, key subgroups, cumulative disease burden, genetic evaluation, and psychosocial support. Stakeholders generated 6 proposed trials from these themes focused on surveillance, surgical intervention, and medical prevention. CONCLUSIONS: Patients and caregivers valued comparative effectiveness kidney stone research that focused on individualized care, shared decision-making, and improvement of patient-reported experiences. This process provided actionable recommendations for future patient-centered clinical trials within kidney stone disease.

Proteome-wide mendelian randomization identifies therapeutic targets for nephrolithiasis.

Kidney Stone Disease (KSD) constitutes a multifaceted disorder, emerging from a confluence of environmental and genetic determinants, and is characterized by a high frequency of occurrence and recurrence. Our objective is to elucidate potential causative proteins and identify prospective pharmacological targets within the context of KSD. This investigation harnessed the unparalleled breadth of plasma protein and KSD pooled genome-wide association study (GWAS) data, sourced from the United Kingdom Biobank Pharma Proteomics Project (UKBPPP) and the FinnGen database version R10. Through Mendelian randomization analysis, proteins exhibiting a causal influence on KSD were pinpointed. Subsequent co-localization analyses affirmed the stability of these findings, while enrichment analyses evaluated their potential for pharmacological intervention. Culminating the study, a phenome-wide association study (PheWAS) was executed, encompassing all phenotypes (2408 phenotypes) catalogued in the FinnGen database version R10. Our MR analysis identified a significant association between elevated plasma levels of proteins FKBPL, ITIH3, and SERPINC1 and increased risk of KSD based on genetic predictors. Conversely, proteins CACYBP, DAG1, ITIH1, and SEMA6C showed a protective effect against KSD, documented with statistical significance (PFDR<0.05). Co-localization analysis confirmed these seven proteins share genetic variants with KSD, signaling a shared genetic basis (PPH3 + PPH4 > 0.8). Enrichment analysis revealed key pathways including hyaluronan metabolism, collagen-rich extracellular matrix, and serine-type endopeptidase inhibition. Additionally, our PheWAS connected the associated proteins with 356 distinct diseases (PFDR<0.05), highlighting intricate disease interrelations. In conclusion, our research elucidated a causal nexus between seven plasma proteins and KSD, enriching our grasp of prospective therapeutic targets.

Biology of calcium homeostasis regulation in intestine and kidney.

Calcium (Ca2+) is an essential divalent cation involved in many bodily functions including bone composition, cell growth and division, blood clotting, and muscle contraction. The bone, intestine, and kidneys are important to the maintenance of Ca2+ homeostasis. Ninety-nine percent of body Ca2+ is stored in the skeleton as hydroxyapatite. The small, and to a lesser extent the large intestine absorbs Ca2+ from the diet. Once in the circulation, Ca2+ is filtered by the glomerulus and the majority, >95%, is reabsorbed along the nephron. The remainder is excreted in the urine. Two general (re)absorptive pathways contribute to the vectorial transport of Ca2+ across renal and intestinal epithelia: 1) a paracellular pathway, which is reliant on claudins in the tight junction of epithelium and the electrochemical gradient and 2) a transcellular pathway, which requires different influx, intracellular buffering/shuttling and basolateral efflux mechanisms, to actively transport Ca2+ across the epithelial cell. Blood Ca2+ levels are maintained by hormones including parathyroid hormone, 1,25-dihydroxyvitamin D3, fibroblast growth factor 23 and through effects of Ca2+-sensing receptor (CaSR) signaling. Disruption of Ca2+ homeostasis can result in altered blood Ca2+ levels and/or hypercalciuria, the latter is a phenomenon closely linked to the formation of kidney stones. Genetic alterations affecting renal Ca2+ handling can cause hypercalciuria, an area of expanding investigation. This review explores the molecular mechanisms governing Ca2+ homeostasis by the intestine and kidneys and discusses clinical aspects of genetic disorders associated with Ca2+-based kidney stone disease.

Relationship between the atherogenic index of plasma and the prevalence of kidney stones: insights from a population-based cross-sectional study.

OBJECTIVE: To investigate the association between atherogenic index of plasma (AIP) and kidney stones (KS) occurrence and recurrence. METHODS: Data were obtained from the National Health and Nutrition Examination Survey (NHANES) 2007-2014. Non-pregnant adults who provided complete information on AIP and KS were included in the analyses. AIP was calculated as log (triglyceride/high-density lipoprotein cholesterol). KS was ascertained with questionnaires. Weighted multivariable logistic regression model and restricted cubic spline (RCS) were applied to examine the associations between AIP and KS occurrence and recurrence. RESULTS: A total of 6488 subjects (weighted mean age 43.19 years and 49.26% male) with a weighted mean AIP of 0.66 were included in this study. The multivariable-adjusted OR for nephrolithiasis occurrence across consecutive tertiles was 1.00 (reference), 1.21 (95% CI: 0.90-1.62), and 1.85 (95% CI: 1.39-2.48), respectively. Moreover, each SD increment of AIP was associated with a 50% (OR:1.50, 95% CI: 1.25-1.81) higher risk of nephrolithiasis recurrence. RCSs showed significant and linear dose-response relationships between AIP and nephrolithiasis occurrence (p-overall = 0.006, p-nonlinear = 0.689) and recurrence (p-overall = 0.001, p-nonlinear = 0.848). The positive associations between AIP and nephrolithiasis occurrence and recurrence persisted in sensitivity analyses, suggesting the robustness of the results. CONCLUSION: In the current US nationally representative cross-sectional study, AIP was positively associated with KS occurrence and recurrence.

Application of warning biopsies in percutaneous nephrolithotomy.

Background: At present, few articles on percutaneous nephrolithotomy (PCNL) for renal calculi and renal pelvic tumors detected by intraoperative biopsy exist, which has provided limited guidance for clinical practice. In this article, we aimed to further study the relationship between renal calculi and renal pelvic tumors. Methods: We retrospectively analyzed the medical records of patients with abnormal mucosal biopsy results who underwent PCNL for kidney stones in the Urology Department of Peking University People's Hospital from January 2011 to November 2021. Results: In total, 2,801 patients underwent PCNL for kidney stones, of whom 69 underwent intraoperative mucosal biopsy. Biopsy results indicated that 8 cases were malignant (11.60%), and 61 cases were benign (88.40%). All malignant cases were renal pelvic carcinoma. Seven were urothelial carcinoma, and one of these was urothelial carcinoma with squamous differentiation. Only one was squamous cell carcinoma. The preoperative information of patients with a malignant mucosa biopsy was analyzed. To provide clinical guidance, an early warning biopsy system was established based on the abnormal mucosa found during the operation. We found that PCNL should be considered if the following risk factors are associated with stones: advanced age, long history of kidney stones, severe hydronephrosis, urinary tract infection, multiple or staghorn stones. Conclusions: Early warning information should be established for patients with kidney stones based on preoperative clinical characteristics and intraoperative mucous membrane observations. An early warning biopsy should be performed for patients with possible tumors to detect tumors in a timely manner and provide early treatment to improve patient prognosis.

Defining physicochemical properties of urinary proteins that determine their inhibitory activities against calcium oxalate kidney stone formation.

We have recently reported a set of urinary proteins that inhibited calcium oxalate (CaOx) stone development. However, physicochemical properties that determine their inhibitory activities remained unknown. Herein, human urinary proteins were chromatographically fractionated into 15 fractions and subjected to various CaOx crystal assays and identification by nanoLC-ESI-Qq-TOF MS/MS. Their physicochemical properties and crystal inhibitory activities were subjected to Pearson correlation analysis. The data showed that almost all urinary protein fractions had crystal inhibitory activities. Up to 128 proteins were identified from each fraction. Crystallization inhibitory activity correlated with percentages of Ca2+-binding proteins, stable proteins, polar amino acids, alpha helix, beta turn, and random coil, but inversely correlated with number of Ox2--binding motifs/protein and percentage of unstable proteins. Crystal aggregation inhibitory activity correlated with percentage of stable proteins but inversely correlated with percentage of unstable proteins. Crystal adhesion inhibitory activity correlated with percentage of stable proteins and GRAVY, but inversely correlated with pI, instability index and percentages of unstable proteins and positively charged amino acids. However, there was no correlation between crystal growth inhibitory activity and any physicochemical properties. In summary, some physicochemical properties of urinary proteins can determine and may be able to predict their CaOx stone inhibitory activities.

Quercus dentata Thunb. leaves extract inhibits CaOx crystallization and ameliorates ethylene glycol-induced CaOx kidney stones via the OPN/CD44 and NLRP3 pathways.

ETHNOPHARMACOLOGICAL RELEVANCE: The leaves of Quercus dentata Thunb. (QD), a member of the Fagaceae family and genus Quercus, with distributions in China, Japan, Korea, and other regions. As recorded in the Ben Cao Gang Mu (Compendium of Materia Medica) and other classical Chinese medical texts, QD has been traditionally employed in Traditional Chinese Medicine (TCM) for their hemostatic and diuretic effects and has been used to treat urinary stones (Lin Zheng). It is also the main ingredient of the Mishitong capsule (MST), a Chinese patent drug, used for kidney stones and ureteral stones. Nonetheless, the specific active ingredients and the mechanisms of QD in treating kidney stones remain to be elucidated, which is crucial for advancing the scientific understanding and clinical application of this traditional medicine. AIM OF STUDY: This study aimed to identify the active constituents of QD water extract (QDWE), explore its inhibitory effects on kidney stones through in vitro and in vivo studies, and elucidate the underlying mechanisms of the OPN/CD44 axis and the NLRP3 signaling pathway to provide a full understanding of its potential as a novel treatment approach against kidney stones. MATERIALS AND METHODS: The micromolecular components in the supernatant of QDWE (QDS) were analyzed by UPLC-Q-Exactive-Orbitrap-MS and the monosaccharide composition of the macromolecular polysaccharide components in the crude polysaccharide (QDP) was determined by pre-column derivatization in HPLC. The effects of QDWE, QDS and QDP on the shape, size, and structure of calcium oxalate (CaOx) crystals in vitro were explored by XRD, FTIR and SEM. The effects of QDWE, QDS and QDP on CaOx kidney stones in SD rats induced by ethylene glycol and VD3 were compared in vivo. Furthermore, the underlying mechanisms of OPN/CD44 and NLRP3 pathways were investigated by Western blot analysis. RESULTS: There were 32 compounds identified in QDS. The monosaccharide composition ratio of QDP was Man: L-Rha: D-GlcA: D-GalA: D-Glc: D-Gal: L-Ara = 1.01: 22.52: 8.27: 38.61: 3.43: 17.80: 6.38, indicating a mixture of pectin-type acidic heteropolysaccharides. QDP had a more significant inhibitory effect on CaOx crystals in vitro than QDWE, which can inhibit the formation of CaOx monohydrate crystals (COM) and convert them into thermodynamically unstable CaOx dihydrate (COD) crystals. The high dose of QDWE exhibited significant in vivo efficacy (P < 0.05), including anti-calculus, diuretic effects, and kidney protection, marked by decreased calcification and stone formation, alongside improved kidney vitality. Furthermore, the protective effects of QDWE were demonstrated to be associated with the OPN/CD44 and NLRP3 pathways. CONCLUSION: The studies identified and analyzed the active constituents of QDWE. Among these, QDP significantly inhibited CaOx crystal generation in vitro and could be a potential component for the treatment of urinary stones in QDWE. Moreover, the results indicated that QDWE had a remarkable therapeutic effect on CaOx stones by modulating the OPN/CD44 axis to affect stone formation and the NLRP3 signaling pathway to mediate inflammation, providing an experimental basis for the mechanism of anti-urinary stone and deep development of QD.

Influence of Dietary Heritage in a Restricted Geographic Area and Role of Food Additives on Risk of Recurrent Kidney Stone.

Dietary factors may be implicated in the formation of kidney stones and should be closely monitored. To achieve this aim, patients are routinely assessed by means of generic dietary recall, a tool widely used by authors in a range of extensive patient populations to record food intake; the findings obtained, however, may be skewed due to dietary variations and underestimation of the effect of food additives. Fifty Frequent Kidney Stone Formers (FKSFs, mean age: 54.3 ± 13.9 years) with normal kidney function, absence of comorbidities, and reliable compliance were selected from a total of 68 patients' resident in Sardinia, an Italian island where genetic admixtures have been relatively rare for generations. The study, conducted from 1 January 2020 to 31 December 2023, was aimed at assessing nutritional values based on the meticulous recording of food quantities, quality, and potential modifications related to food preparation. Patients were selected during an initial clinical check-up and all efforts made to ensure they were capable of reliably recording all food and drinks consumed. A seven-day food diary was provided in which food and drink intake and their impact on 24 h urine output was recorded. The following parameters were measured in both foods and urine output: citrates, oxalates, calcium, phosphorous, uric acid, proteins and nitrogen compounds, magnesium, sulfates, potassium, carbohydrates, free fatty acids. Study outcomes established the presence of hypocitraturia, hyperoxaluria, hypercalciuria, and moderately high levels of nitrogen compounds. Univariate analysis followed by multivariate analysis for further confirmation were performed and the following observations made. Citrate intake correlated with citraturia but did not promote oxaluria; calcium intake promoted onset of sulfaturia, azoturia, and ammoniuria, whilst magnesium correlated with magnesiuria but not with oxaluria, calciuria, phosphaturia, and azoturia; sulfate intake elicited onset of azoturia but not kaliuresis; potassium intake promoted oxaluria and protein intake resulted in onset of ammoniuria and azoturia. (A) The chemical composition of urine based on dietary intake is hard to predict without taking into account the presence of dietary and urinary interferents; (B) the geographic isolation of patients studied underlines the importance of epigenetics in maintaining a traditional dietary heritage. (C) Moreover, the widespread use of food additives should consistently be taken into account to ensure a correct diagnosis of FKSF and set up a valid treatment plan.