Recent advances on the mechanisms of kidney stone formation (Review)

Research Landscape and Pharmacological Mechanisms of Traditional Chinese Medicines in Treating and Preventing Urolithiasis: Unearthing an Anti-urolithic Treasure Trove

ETHNOPHARMACOLOGICAL RELEVANCE

Urolithiasis represents a predominant concern within urology due to its high recurrence rate and consequential surgical complications. Traditional Chinese Medicine (TCM), with a history spanning over 2000 years in treating kidney diseases, not only offers a less invasive and cost-effective option for treating and preventing urolithiasis, but also serves as a pharmacological treasure trove for the development of anti-urolithic drugs.

AIM OF THE STUDY

With the continuous deepening of research on the anti-urolithic effects of Chinese medicines, the pharmacological mechanisms of TCMs against urolithiasis are continuously evolving. Therefore, it is essential to summarize the current research status, clinical effectiveness, and mechanisms of TCM in treating and preventing urolithiasis, to ascertain its potential in anti-urolithic treatments, and to provide a reference for future anti-urolithiasis drug research.

METHODS

The electronic databases such as PubMed, Web of Science, and China National Knowledge Infrastructure (CNKI) have been utilized to retrieve relevant literature spanning from 2000 to September 2023, using keywords "Traditional Chinese Medicine" and "Urolithiasis". Then we conducted a visual analysis of the current status of related research, as well as a systematic organization of the therapeutic effects and underlying mechanisms of anti-urolithic TCMs.

RESULTS

Through the organization of research models, therapeutic effects, and active ingredients of 31 potential anti-urolithic TCMs, we have systematically summarized the underlying mechanisms of TCMs in management of urolithiasis. Mechanistically, Chinese herbs facilitate stone expulsion by enhancing diuresis, instigating anti-spasmodic effects, and promoting ureteral peristalsis when addressing calculi. They also harbor the potential to dissolve pre-existing stones. In terms of stone recurrence prevention, TCM compounds obstruct stone formation through targeting the sequence of crystal adhesion, nucleation, growth, and aggregation to inhibit stone formation. Additionally, TCM's significant roles include stifling oxidative stress, augmenting urinary stone inhibitors, and harmonizing oxalate metabolism, all of which are critical actions in stone prevention.

CONCLUSION

The anti-urolithic mechanism of TCM is multifaceted. Investigating the anti-urolithiasis mechanisms of TCM not only illuminates the potential of Chinese medicine in treating and preventing urolithiasis, but also uncovers active molecules and targets for drug treatment against calculus formation.

Urinary stone analysis and clinical characteristics of 496 patients in Taiwan

Evaluate urinary stone components' epidemiological features in urolithiasis individuals and explore potential correlations between stone components and patients' clinical characteristics. A retrospective analysis of urinary stone compositions in 496 patients from a northern Taiwan medical center (February 2006 to October 2021) was conducted. We investigated associations between sex, age, body mass index (BMI), hypertension, diabetes mellitus (DM), hyperlipidemia (HLP), gout, coronary artery disease (CAD), cerebral vascular accident (CVA), chronic kidney disease (CKD), habits, urine pH, and three main stone groups: calcium oxalate (CaOx), calcium phosphate (CaP), and uric acid (UA). Males accounted for 66.5% of cases, with a male-to-female ratio of 1.99:1. Males were negatively associated with CaP stones (OR 0.313, p < 0.001) and positively with UA stones (OR 2.456, p = 0.009). Age showed a negative correlation with CaOx stones (OR 0.987, p = 0.040) and a positive correlation with UA stones (OR 1.023, p < 0.001). DM had a protective effect against CaP stones (OR 0.316, p = 0.004). Gout had a positive association with UA stones (OR 2.085, p = 0.035). Smoking was adversely associated with UA stones (OR 0.350, p = 0.018). Higher urine pH was a risk factor for CaP stones (OR 1.641, p = 0.001) and a protective factor against UA stones (OR 0.296, p < 0.001). These results may provide insights into the pathogenesis of urinary stones and the development of preventative strategies for high-risk populations. Further research is required to confirm and expand upon these findings.

Renal papillary tip biopsy in stone formers: a review of clinical safety and insights

Alexander Randall first published renal papillary tip findings from stone formers in 1937, paving the way for endoscopic assessment to study stone pathogenesis. We performed a literature search to evaluate the safety of papillary tip biopsy and clinical insights gained from modern renal papillary investigations. A search on the topic of renal papillary biopsy provided an overview of Randall's plaques (RP), classification systems for renal papillary grading, and a summary of procedure type, complications, and outcomes. Within 26 identified manuscripts, 660 individuals underwent papillary tip biopsy percutaneously (n = 562), endoscopically (n = 37), or unspecified (n = 23). Post-operative hemoglobin changes were similar to controls. One individual (0.2%) reported fever > 38°, and long-term mean serum creatinine post-biopsy (n = 32) was unchanged. Biopsies during ureteroscopy or PCNL added ~20-30 min of procedure time. Compared to controls, papillary plaque-containing tissue had upregulation in pro-inflammatory genes, immune cells, and cellular apoptosis. Urinary calcium and papillary plaque coverage were found to differ between RP and non-RP stone formers, suggesting differing underlying pathophysiology for these groups. Two renal papillary scoring systems have been externally validated and are used to classify stone formers. Overall, this review shows that renal papillary biopsies have a low complication profile with high potential for further research. Systematic adaption of a papillary grading scale, newer tissue analysis techniques, and the development of animal models of Randall's plaque may allow further exploration of plaque pathogenesis and identify targets for prevention therapies in patients with nephrolithiasis.

Microbial communities, antibiotic resistance genes, and virulence factors in urinary infectious stone-associated urinary tract infections

Urinary infectious stones are challenging due to bacterial involvement, necessitating a comprehensive understanding of these conditions. Antibiotic-resistant urease-producing bacteria further complicate clinical management. In this study, analysis of urine and stone samples from urinary tract infection (UTI) patients revealed microbial shifts, gene enrichment in stones, and metabolic pathway disparities; antibiotic resistance gene trends were phylum-specific, urease-producing bacteria are at risk of acquiring AMR carried by Enterobacteriaceae under antibiotic, emphasizing potential AMR dissemination between them; Correlations of key pathogenic species in kidney stone and urine microbial communities highlight the need for targeted therapeutic strategies to manage complexities in UTIs; Stones and urine contain a variety of deleterious genes even before antibiotic use, and piperacillin/tazobactam better reduced the abundance of antibiotic resistance genes in stones and urine. The presence of diverse antibiotic resistance and virulence genes underscores challenges in clinical management and emphasizes the need for effective treatment strategies to mitigate risks associated with UTIs and urinary infectious stone formation. Ongoing research is vital for advancing knowledge and developing innovative approaches to address these urological conditions.

Association of calcific rotator cuff tendinopathy with nephrolithiasis and/or cholelithiasis: A case-control study

This study aimed to examine the association between calcific rotator cuff tendinopathy (RCT) and nephrolithiasis and/or cholelithiasis. A case-control study was conducted on patients diagnosed with RCT between June 2016 and June 2022. RCT was confirmed by ultrasound, and patients were divided into 2 groups: calcific RCT (case) and non-calcific RCT (control). Data were collected retrospectively from electronic medical records and completed by phone calls, looking for a history of nephrolithiasis and/or cholelithiasis; based on clinical features or incidental findings on abdominal and pelvic imaging. A total of 210 patients with RCT were included. Among the 95 cases of calcific RCT, 43 had a history of lithiasis (45.3%) against 23 (20%) from the non-calcific RCT group (P < .001); 21 patients suffered from nephrolithiasis (22.1%) and 26 had cholelithiasis (27.4%) versus 10 (8.7%) (P = .006) and 16 (13.9%) (P = .015) in the non-calcific RCT group, respectively. Logistic regression showed that the independent predictors of calcific RCT included a history of nephrolithiasis (OR, 4.38; 95% CI: 1.61-11.92, P = .004) and a history of cholelithiasis (OR, 3.83; 95% CI: 1.64-8.94, P = .002). In patients with calcific RCT, the occurrence of lithiasis was significantly associated in the bivariate analysis with higher age, body mass index, fasting blood sugar, and HbA1c (all with P < .05), but only with the presence of another site of calcific tendinopathy than the shoulder (OR, 3.11; 95% CI: 1.12-8.65, P = .03) in the multivariate analysis. Nephrolithiasis and/or cholelithiasis are associated with calcific RCT, and their presence predicts calcific RCT at least 3 times. Further research is required to determine the common risk factors and preventive measures against lithogenesis in patients with calcific RCT, nephrolithiasis, and cholelithiasis.

Cell death‑related molecules and targets in the progression of urolithiasis (Review)

Urolithiasis is a high‑incidence disease caused by calcium oxalate (mainly), uric acid, calcium phosphate, struvite, apatite, cystine and other stones. The development of kidney stones is closely related to renal tubule cell damage and crystal adhesion and aggregation. Cell death, comprising the core steps of cell damage, can be classified into various types (i.e., apoptosis, ferroptosis, necroptosis and pyroptosis). Different crystal types, concentrations, morphologies and sizes cause tubular cell damage via the regulation of different forms of cell death. Oxidative stress caused by high oxalate or crystal concentrations is considered to be a precursor to a variety of types of cell death. In addition, complex crosstalk exists among numerous signaling pathways and their key molecules in various types of cell death. Urolithiasis is considered a metabolic disorder, and tricarboxylic acid cycle‑related molecules, such as citrate and succinate, are closely related to cell death and the inhibition of stone development. However, a literature review of the associations between kidney stone development, metabolism and various types of cell death is currently lacking, at least to the best of our knowledge. Thus, the present review summarizes the major advances in the understanding of regulated cell death and urolithiasis progression.

Gut and Urinary Microbiota in Cats with Kidney Stones

Upper urinary tract urolithiasis is an emerging disease in cats, with 98% of kidney stones composed of calcium oxalate. In humans, disturbances in the intestinal and urinary microbiota are suspected to contribute to the formation of calcium oxalate stones. We hypothesized that similar mechanisms may be at play in cats. This study examines the intestinal and urinary microbiota of nine cats with kidney stones compared to nine healthy cats before, during, and after treatment with the antibiotic cefovecin, a cephalosporin. Initially, cats with kidney stones displayed a less diverse intestinal microbiota. Antibiotic treatment reduced microbiota diversity in both groups. The absence of specific intestinal bacteria could lead to a loss of the functions these bacteria perform, such as oxalate degradation, which may contribute to the formation of calcium oxalate stones. This study confirms the presence of a distinct urobiome in cats with kidney stones, characterized by greater richness and diversity compared to healthy cats. These findings highlight the potential of microbiota modulation as a strategy to prevent renal lithiasis in cats.

Protective Role of Rosmarinic Acid in Experimental Urolithiasis: Understanding Its Impact on Renal Parameters

This study aimed to assess the ability of rosmarinic acid (RA) to prevent kidney stone formation in an ethylene glycol and ammonium chloride (EG/AC) model. There was an increase in diuresis in the normotensive (NTRs) and hypertensive rats (SHRs) treated with hydrochlorothiazide (HCTZ) and exposed to EG/AC, while RA restored urine volume in NTRs. The EG/AC groups exhibited lower urine pH and electrolyte imbalance; these parameters were not affected by any of the treatments. Both HCTZ+EG/AC and RA+EG/AC reduced calcium oxalate crystal formation in NTR and SHR urine. Kidney tissue analysis revealed alterations in oxidative stress and inflammation parameters in all EG/AC-receiving groups, with RA enhancing antioxidant defenses in SHRs. Additionally, crystals were found in the kidney histology of all EG/AC-exposed groups, with reduced Bowman's capsule areas in NTRs and SHRs. The NTR VEH+EG/AC group showed intense renal damage, while the others maintained their structures, where treatments with HCTZ and RA were fundamental for kidney protection in the NTRs. Docking analysis showed that RA exhibited good binding affinity with matrix metalloproteinase-9, phosphoethanolamine cytidylyltransferase, and human glycolate oxidase enzymes. The data disclosed herein underscore the importance of further research to understand the underlying mechanisms better and validate the potential of RA for clinical use.

Establishment of an artificial urine model in vitro and rat or pig model in vivo to evaluate urinary crystal adherence

The current study aimed to establish an experimental model in vitro and in vivo of urinary crystal deposition on the surface of ureteral stents, to evaluate the ability to prevent crystal adhesion. Non-treated ureteral stents were placed in artificial urine under various conditions in vitro. In vivo, ethylene glycol and hydroxyproline were administered orally to rats and pigs, and urinary crystals and urinary Ca were investigated by Inductively Coupled Plasma-Optical Emission Spectrometer. in vitro, during the 3- and 4-week immersion periods, more crystals adhered to the ureteral stent in artificial urine model 1 than the other artificial urine models (p < 0.01). Comparing the presence or absence of urea in the composition of the artificial urine, the artificial urine without urea showed less variability in pH change and more crystal adhesion (p < 0.05). Starting the experiment at pH 6.3 resulted in the highest amount of crystal adhesion to the ureteral stent (p < 0.05). In vivo, urinary crystals and urinary Ca increased in rat and pig experimental models. This experimental model in vitro and in vivo can be used to evaluate the ability to prevent crystal adhesion and deposition in the development of new ureteral stents to reduce ureteral stent-related side effects in patients.

Association between composite dietary antioxidant index and kidney stone prevalence in adults: data from National Health and Nutrition Examination Survey (NHANES, 2007-2018)

Background

The high prevalence of kidney stones in adults worldwide has prompted research into potential interventions, one of which involves exploring the consumption of antioxidants that may confer protective effects. However, the relationship between the composite dietary antioxidant index (CDAI), a crucial measure used to assess an individual's overall antioxidant capacity from daily dietary intake, and kidney stones remains unclear. Therefore, we conducted cross-sectional analysis to examine the association between CDAI and kidney stone prevalence.

Methods

The analysis was conducted utilizing data from the National Health and Nutrition Examination Survey (NHANES) from 2007 to 2018. Antioxidant intake was derived from two 24-h dietary recalls surveys, while CDAI, a comprehensive measure that includes antioxidants like vitamins A, C, and E, zinc, selenium, and carotenoids, was calculated. Multivariate logistic regression and restricted cubic spline (RCS) regression were utilized to examine the association between CDAI and the prevalence of kidney stones.

Results

The study included a total of 28,516 participants, with 2,748 individuals having a history of kidney stones. The median of CDAI was -0.01 (-2.02, 2.37). Individuals in the fourth quartile of CDAI exhibited a significantly lower prevalence of kidney stones compared to those in the first quartile (Odds Ratio [OR] = 0.769 [0.633-0.935]), even after adjusting for potential confounding factors (including age, sex, race, education level, poverty income ratio, smoking status, drinking status, body mass index (BMI), energy intake levels, physical activity level, serum calcium concentration, estimated glomerular filtration rate (eGFR), hypertension, diabetes and supplement use). The RCS analysis revealed a non-linear relationship between CDAI and kidney stone prevalence, with inflection points identified at 0.06 (p for non-linearity = 0.039). Subgroup analysis demonstrated consistent CDAI-kidney stone prevalence associations across all subsets. Furthermore, a significant inverse correlation was observed between CDAI and inflammatory markers.

Conclusion

This study provides evidence supporting a reciprocal correlation between adult dietary antioxidant intake, as measured by CDAI, and kidney stone prevalence. These findings emphasize the potential benefits of consuming dietary antioxidants in lowering the risk of kidney stone formation.

Investigation of the application of Enhanced Recovery After Surgery (ERAS) in elderly patients undergoing surgery for kidney stones

OBJECTIVE

To investigate the efficacy and application of Enhanced Recovery After Surgery (ERAS) in elderly patients undergoing surgery for kidney stones.

METHODS

Clinical data of 104 elderly patients who underwent kidney stone surgery at West China Hospital, Sichuan University from January 2020 to December 2022 were retrospectively analyzed in this study. The patients were divided into two groups according to different nursing plans. Among them, 52 patients in the control group received conventional nursing, and 52 patients in the study group received ERAS mode nursing. Postoperative recovery, anxiety, complications, stress response and quality of life were compared between the two groups.

RESULTS

The time to recovery of postoperative rehabilitation indices in the research group was significantly shorter compared to the control group (P < 0.05). The research group also exhibited a significantly lower incidence of complications such as hematuria, abdominal pain, vomiting, chills, fever, and hypotension (all P < 0.05). Before the initiation of nursing care, there were no significant differences in the State Anxiety Inventory (SAI) and Trait Anxiety Inventory (TAI) scores between the two groups (both P > 0.05). However, after nursing care, the research group exhibited lower SAI and TAI scores compared to the control group (all P < 0.05). Similarly, there was no significant difference in the General Quality of Life Inventory-74 (GQOLI-74) scores in any dimension between the two groups before nursing care (P > 0.05), but the research group showcased higher scores in every dimension after nursing care (P < 0.05). The levels of Heme Oxygenase-1 (HO-1), Endothelin-1 (ET-1), Adrenocorticotropic Hormone (ACTH), and Cortisol (Cor) were significantly lower in the research group after nursing care (all P < 0.05). The acknowledgment and approval scores of nursing care in the research group were higher than those in the control group (P < 0.05).

CONCLUSION

The application of ERAS in elderly patients with kidney stones undergoing transurethral ureteral holmium laser lithotripsy is efficacious in mitigating stress reactions, enhancing quality of life and reducing perioperative anxiety, minimizing the incidence of complications, and promoting overall patient recovery.

Traditional Uses, Phytochemistry, and Pharmacological Activities of Vernonia cinerea (L.) Less.: An Updated Review

Vernonia cinerea (L.) Less. is a perennial herbaceous plant found mainly in tropical areas, particularly in Southeast Asia, South America, and India. Various parts of V. cinerea have traditionally been used in folk medicine to treat several diseases, such as malaria, fever, and liver diseases. V. cinerea has so far yielded about 92 secondary metabolites. The majority of these are sesquiterpene lactones, but triterpenes, flavonoids, steroids, phenolics, and other compounds are present as well. V. cinerea crude extracts reportedly exhibit anti-inflammatory, antiprotozoal, antidiabetic, anticancer, antimicrobial, antioxidant, and renoprotective activities. This study aims to provide the latest up-to-date information on the botanical characterization, distribution, traditional uses, phytochemistry, and pharmacological activity of V. cinerea. Information on V. cinerea was thoroughly reviewed. The literature published between 1950 and 2024 was compiled through online bibliographic databases, including SciFinder, Web of Science, Google Scholar, PubMed, ScienceDirect, Springer Link, Wiley, and the MDPI online library. The keywords used for the literature search included Vernonia cinerea (L.) Less. and the synonyms Cyanthillium cinereum (L.) H.Rob., Conyza cinerea L., and various others.

Exploring the association between multiple factors and urolithiasis: A retrospective study and Mendelian randomization analysis

To investigate the relationship between several factors and urinary stone as well as different stone compositions. To guide the diagnosis, treatment, and prevention of urinary stone recurrence. We used bidirectional Mendelian randomization to analyze the causal relationship between hypertension and urinary stones, diabetes and urinary stones, and body mass index (BMI) and urinary stones. We retrospectively analyzed the medical records of patients with urinary stones admitted to a tertiary care hospital in Chongqing, China, from July 2015 to October 2022. Patients were included when they were first diagnosed with urinary stones. The odds ratio of calculi on hypertension estimated by inverse variance weighted was 8.46 (95%CI: 4.00-17.90, P = 2.25 × 10-8). The stone composition analysis showed that there were 3101 (67.02%) mixed, 1322 (28.57%) calcium oxalate monohydrate, 148 (3.20%) anhydrous uric acid, 16 (0.35%) magnesium ammonium phosphate hexahydrate, 11 (0.24%) dicalcium phosphate dihydrate, 10 (0.22%) carbonate apatite, 8 (0.17%) L-cystine, 4 ammonium uric acid (0.09%), and 7 other stone types (0.15%). Mendelian randomization studies have proven that urinary stones may be a potential risk factor for hypertension, while there is no causal relationship between diabetes and stones, BMI, and stones. Our retrospective study has shown that urinary stone components are closely associated with sex, age, hypertension, diabetes, and BMI. It is reasonable to suspect that treating a single stone component is ineffective in preventing recurrence. We also found that the peak incidence of urinary stones was at the most active stage of most people's working lives.

CCR2 antagonist attenuates calcium oxalate-induced kidney oxidative stress and inflammation by regulating macrophage activation

C-C chemokine receptor type 2 (CCR2) is a monocyte chemokine associated with oxidative stress and inflammation. Kidney stones (KS) are composed of calcium oxalate (CaOx), which trigger renal oxidative stress and inflammatory. This study aims to evaluate the effects of CCR2 on KS in vivo and in vitro. Eight-week-old male C57BL/6J mice were intraperitoneally injected with glyoxylate (GOX) daily to establish a KS model, and along with CCR2 antagonist (INCB3344) treatment on days 2, 4, and 6. The results showed that CCR2 antagonist reduced renal injury markers (blood urea nitrogen and serum creatinine), alleviated renal tubular injury and CaOx crystal deposition. CCR2 antagonist also decreased CCR2 expression induced by GOX treatment and increased Nrf2 expression. GOX treatment promoted malondialdehyde (MDA) production, decreased glutathione (GSH) content, and inhibited catalase (CAT) and superoxide dismutase (SOD) activity, however, CCR2 antagonist attenuated the above effects of GOX. CCR2 antagonist had inhibitory effects on GOX-induced inflammatory cytokine expression (IL1B, IL6 and MCP1), and inhibited apoptosis by increasing Bcl-2 expression and decreasing Bax and cleaved-caspase 3 expression. In vitro experiments were performed by co-culture model of CaOx-induced damaged HK-2 cells and macrophage-like THP-1 cells. CCR2 antagonist inhibited CaOx-induced THP-1 cell M1 polarization by decreasing the TNF-α, IL6 and iNOS levels, and further alleviated CaOx-induced oxidative stress damage, inflammatory response and apoptosis of HK-2 cells. The study suggests that CCR2 antagonist may be resistant to CaOx crystals-induced oxidative stress and inflammation by inhibiting macrophage M1 polarization.

Oxalates: Dietary Oxalates and Kidney Inflammation: A Literature Review

This literature review explores the role of dietary oxalate in the development of chronic inflammatory kidney disease in middle-aged and older individuals. The authors pose the following questions: Is oxalate produced endogenously? If food sources contribute to chronic kidney disease and inflammation, what are those foods? What role do cultural food preparation and cooking play in denaturing food oxalates? The concentration of oxalates found within the body at any particular time is not limited to edible plants; normal human metabolic processes of breaking down ascorbic acid may create up to 30 mg of oxalate daily. Research supports urolithiasis as a common urologic disease in industrialized societies. Approximately 80% of kidney stones are composed of calcium oxalate, resulting in hyperoxaluria. Exogenous (originating outside the cell or organism) oxalate sources include ascorbic acid, amino acids, and glyoxal metabolism. Additional research estimates the daily endogenous (produced within the cell or organism) production of oxalate to be 10-25 mg. Suboptimal colonization of oxalate-degrading bacteria and malabsorptive disease are also contributing factors to the development of chronic kidney disease. Oxalate transcellular processes, though poorly understood, rely on multifunctional anion exchangers, and are currently being investigated. A review of research showed that normal human metabolic processes, including the breakdown of ascorbic acid, account for 35-55% of circulating oxalates and can create ≤30 mg of circulating serum oxalate daily. Glyoxylic acid accounts for 50-70% of circulating urinary oxalate in compromised individuals with liver glycation, bacterial insufficiencies, malabsorption, and anion exchange challenges. For persons with a family history of kidney stones, consumption of foods high in oxalates may be consumed in moderation, provided there is adequate calcium intake in the diet to decrease the absorption of oxalates from the meal ingested.

Association of serum soluble α‑klotho with risk of kidney stone disease: a population-based cross-sectional study

BACKGROUND

The aim of the study was to explore the association of serum soluble klotho with kidney stone disease (KSD) in the general population over the age of 40 years in the United States.

METHODS

We integrated the data in National Health and Nutrition Examination Survey from 2007 to 2016 years. The relationship between serum soluble α‑klotho and prevalence of KSD was analyzed by constructing weighted multivariable logistic regression model, restricted cubic spline (RCS) curve, and subgroup analyses.

RESULTS

In the study, a total of 13,722 individuals were included in our study. A U-shaped association between serum soluble klotho and the risk of KSD was shown by the RCS curve (P value for nonlinear < 0.05). In the full adjusted model, compared with the lowest quartile of serum soluble α‑klotho, the adjusted odd ratios (95% confidence intervals) for KSD across the quartiles were (0.999 (0.859, 1.164), 1.005 (0.858, 1.176), and 1.061 (0.911, 1.235)). Subgroup analyses also showed that the U-shaped association of serum soluble α‑klotho with KSD was found among subjects who were age < 60 years, female or male, with or without hypertension, and BMI ≥ 30 kg/m2.

CONCLUSIONS

Our findings suggested that serum klotho levels had a U-shaped correlation with risk of KSD. When the Klotho level is at 818.66 pg/mL, prevalence of KSD is lowest. Therefore, maintaining a certain level of serum soluble α‑klotho could prevent the occurrence of KSD.

Multivitamins co-intake can reduce the prevalence of kidney stones: a large-scale cross-sectional study

BACKGROUND

This research aimed to explore the association between changes in the intake of common individual vitamins and combinations of vitamins and the prevalence of kidney calculi.

METHODS

We used data from NHANES to investigate the association between nine common vitamins and kidney stone prevalence. Participants were clustered into several vitamin exposure patterns using an unsupervised K-means clustering method. We used logistic regression models and restrictive cubic spline curves to explore the influence of vitamins.

RESULTS

The regression model exposed that compared to lower intake, high intake of vitamin B6 [Q4: OR (95% CI) = 0.76 (0.62, 0.93)], vitamin C [Q4: OR (95% CI) = 0.73 (0.59, 0.90)] and vitamin D [Q4: OR (95% CI) = 0.77 (0.64, 0.94)] individually exerted protective effects against the prevalence of kidney stones. Furthermore, the restrictive cubic spline analysis showed that the protective effect against the prevalence of kidney stones is enhanced as the take of vitamin B6 and vitamin D increased. Moreover, with the increase in vitamin C intake, its protective effect may turn into a risk factor. Regarding mixed exposure, Cluster 4 exhibited a significant protective effect against kidney stones compared with Cluster 1 [Model 3: OR (95% CI) = 0.79 (0.64, 0.98)].

CONCLUSIONS

Our research revealed that high levels of vitamin B6 and vitamin D intake were linked to a lower prevalence of kidney stone. With the gradual increase intake of vitamin C, the prevalence of kidney calculi decreased first and then increased. In addition, the co-exposure of nine vitamins is a protective factor for kidney stone disease.

Antiurease Activity of Antibiotics: In Vitro, In Silico, Structure Activity Relationship, and MD Simulations of Cephalosporins and Fluoroquinolones

Helicobacter pylori infection is widespread in 50% of the world's population and is associated with gastric ulcers and related disorders that ultimately culminate in gastric cancer. Levofloxacin-based, or clarithromycin-based, triple therapy is frequently used to inhibit the bacterial urease enzyme for the eradication of H. pylori. A comprehensive investigation based on the urease inhibitory profiles of antibiotics and their computational implications is lacking in the scientific literature. The present study was aimed specifically to determine the antiurease activities within the realms of cephalosporins and fluoroquinolones by in vitro methods supported with in silico investigations. The results demonstrate the jack bean urease inhibitory activity of cephalosporins, wherein cefadroxil, cefpodoxime, cefotaxime, and cefaclor displayed inhibitions (IC50 21.35 ± 0.64 to 62.86 ± 0.78 μM) compared with the standard thiourea (IC50 21.25 ± 0.15 μM). Among fluoroquinolones, levofloxacin, ofloxacin, and gemifloxacin (IC50 7.24 ± 0.29 to 16.53 ± 0.85 μM) unveiled remarkable inhibitory profiles. Levofloxacin and ofloxacin exhibited competitive inhibition against the said enzyme. Ciprofloxacin and moxifloxacin displayed weak urease inhibitions. During molecular docking studies, Asp362, Gly279, Arg338, Asn168, Asp223, Gln364, and Met366 were involved in hydrogen bonding in fluoroquinolones, and hydrogen bonding was established with Arg338, His248, Asn168 residues, and metal Ni601 and Ni602 of the enzyme. MD simulations and MMPBSA results demonstrated the existence of significant protein-ligand binding. Overall, these results warrant further investigations into the significance of these active molecules in relation to their inhibitory potential against the targeted urease enzyme.

N-acetylcysteine regulates oxalate induced injury of renal tubular epithelial cells through CDKN2B/TGF-β/SMAD axis

This study was aimed to investigate the preventive effects of N-acetyl-L-cysteine (NAC) against renal tubular cell injury induced by oxalate and stone formation and further explore the related mechanism. Transcriptome sequencing combined with bioinformatics analysis were performed to identify differentially expressed gene (DEG) and related pathways. HK-2 cells were pretreated with or without antioxidant NAC/with or silencing DEG before exposed to sodium oxalate. Then, the cell viability, oxidative biomarkers of superoxidase dismutase (SOD) and malondialdehyde (MDA), apoptosis and cell cycle were measured through CCK8, ELISA and flow cytometry assay, respectively. Male SD rats were separated into control group, hyperoxaluria (HOx) group, NAC intervention group, and TGF-β/SMAD pathway inhibitor group. After treatment, the structure changes and oxidative stress and CaOx crystals deposition were evaluated in renal tissues by H&E staining, immunohistochemical and Pizzolato method. The expression of TGF-β/SMAD pathway related proteins (TGF-β1, SMAD3 and SMAD7) were determined by Western blot in vivo and in vitro. CDKN2B is a DEG screened by transcriptome sequencing combined with bioinformatics analysis, and verified by qRT-PCR. Sodium oxalate induced declined HK-2 cell viability, in parallel with inhibited cellular oxidative stress and apoptosis. The changes induced by oxalate in HK-2 cells were significantly reversed by NAC treatment or the silencing of CDKN2B. The cell structure damage and CaOx crystals deposition were observed in kidney tissues of HOx group. Meanwhile, the expression levels of SOD and 8-OHdG were detected in kidney tissues of HOx group. The changes induced by oxalate in kidney tissues were significantly reversed by NAC treatment. Besides, expression of SMAD7 was significantly down-regulated, while TGF-β1 and SMAD3 were accumulated induced by oxalate in vitro and in vivo. The expression levels of TGF-β/SMAD pathway related proteins induced by oxalate were reversed by NAC. In conclusion, we found that NAC could play an anti-calculus role by mediating CDKN2B/TGF-β/SMAD axis.

Pathophysiology and Main Molecular Mechanisms of Urinary Stone Formation and Recurrence

Kidney stone disease (KSD) is one of the most common urological diseases. The incidence of kidney stones has increased dramatically in the last few decades. Kidney stones are mineral deposits in the calyces or the pelvis, free or attached to the renal papillae. They contain crystals and organic components, and they are made when urine is supersaturated with minerals. Calcium-containing stones are the most common, with calcium oxalate as the main component of most stones. However, many of these form on a calcium phosphate matrix called Randall's plaque, which is found on the surface of the kidney papilla. The etiology is multifactorial, and the recurrence rate is as high as 50% within 5 years after the first stone onset. There is a great need for recurrence prevention that requires a better understanding of the mechanisms involved in stone formation to facilitate the development of more effective drugs. This review aims to understand the pathophysiology and the main molecular mechanisms known to date to prevent recurrences, which requires behavioral and nutritional interventions, as well as pharmacological treatments that are specific to the type of stone.

Recombinant bone matrix maintains the graft space, induces vascularized bone regeneration and preserves canine tooth extraction socket structure

AIM

Recombinant bone matrix (RBM) is a newly conceived and engineered porous bone graft granule of average size 600 μm composed of purified recombinant collagen peptide. We sought to examine the behaviour with time of RBM that was grafted in the canine tooth extraction socket.

MATERIALS AND METHODS

The canine tooth extraction socket of the hemisectioned mandibular third premolar distal root was grafted with RBM granules, whereas the opposite side extraction socket served as non-grafted control. The mandibular samples were harvested at 1, 3 and 6 months of healing and subjected to micro-CT imaging and decalcified paraffin-embedded histology. Separately, the effect of RBM was compared with that of deproteinized cancellous bovine bone (DCBB) and bovine atelocollagen plug (BACP) in the canine tooth extraction model at 3 months of healing.

RESULTS

RBM maintained the grafted space in the socket and the gingival connective tissue until new bone was formed within its porous space. The regenerated bone was highly vascularized and continued to mature, while RBM was completely bioresorbed by 6 months. The buccal and lingual alveolar ridge heights of the RBM-grafted extraction socket was better preserved than those of non-grafted control sockets. The degree of socket preservation by RBM was equivalent to that by DCBB, although their healing mechanisms were different.

CONCLUSIONS

This study demonstrated that RBM induced controlled active bone regeneration and preserved the extraction socket structure in a canine model. Bioresorbable RBM engineered without animal or human source materials presents a novel bone graft category with robust bone regenerative property.

Ferroptosis and its emerging role in kidney stone formation

Kidney stone is a common and highly recurrent disease in urology, and its pathogenesis is associated with various factors. However, its precise pathogenesis is still unknown. Ferroptosis describes a form of regulated cell death that is driven by unrestricted lipid peroxidation, which does not require the activation of caspase and can be suppressed by iron chelators, lipophilic antioxidants, inhibitors of lipid peroxidation, and depletion of polyunsaturated fatty acids. Recent studies have shown that ferroptosis plays a crucial role in kidney stone formation. An increasing number of studies have shown that calcium oxalate, urate, phosphate, and selenium deficiency induce ferroptosis and promote kidney stone formation through mechanisms such as oxidative stress, endoplasmic reticulum stress, and autophagy. We also offered a new direction for the downstream mechanism of ferroptosis in kidney stone formation based on the "death wave" phenomenon. We reviewed the emerging role of ferroptosis in kidney stone formation and provided new ideas for the future treatment and prevention of kidney stones.

Phosphorus Intake and Potential Dietary Influences Examined via 24-Hour Urinary Biomarker Measurements in German Children and Adolescents Over 3 Decades

BACKGROUND

Increases in phosphorus intake have been observed over the past years in adult populations. However, biomarker-based data are lacking on whether or not phosphorus intake also increased in children.

OBJECTIVE

The aim of this study was to examine 24-hour urinary phosphate excretion (PO4-Ex) and diet-related biomarkers potentially influencing phosphorus status in German children and adolescents from 1985 to 2015.

DESIGN

This longitudinal noninvasive biomarker-based cohort study examined 24-hour urine samples from children and adolescents of the Dortmund Nutritional and Anthropometric Longitudinally Designed Study, collected over 3 decades.

PARTICIPANTS/SETTING

Examined individuals (n = 1,057) were healthy participants of the Dortmund Nutritional and Anthropometric Longitudinally Designed Study, situated in Dortmund, Germany, who had been asked to collect one yearly 24-hour urine sample. Six thousand seven hundred thirty-seven samples collected from participants aged 3 to 17 years between 1985 (baseline) and 2015, were included.

MAIN OUTCOME MEASURES

phosphorus intake was examined biomarker-based by analyzed PO4-Ex in 24-hour urine samples. Whether acid-base status and intakes of protein, salt, and fruits and vegetables, may have relevantly contributed to PO4-Ex levels was assessed by determining 24-hour excretions of net acid, urea-nitrogen, and sodium as well as specific standardized excretions of potassium plus oxalate.

STATISTICAL ANALYSES PERFORMED

Trend analysis over 30 years and potentially influencing diet factors were examined using linear mixed-effect regression models (PROC-MIXED). Adjustments for sex, age, and body surface area were performed.

RESULTS

No change was identifiable for PO4-Ex over the 3 decades; neither in 3 to 8, 9 to 13, nor in 14 to 17 year olds. However, sodium excretion increased (P = .001). PROC-MIXED analysis on intraindividual changes in PO4-Ex revealed direct relationships with net acid excretion, urea-nitrogen, and sodium excretion and an inverse relationship with a biomarker of fruit and vegetable intake.

CONCLUSIONS

Despite a direct relationship between PO4-Ex and a biomarker of industrially processed food consumption; that is, sodium excretion, which showed an increasing time trend, phosphorus intake was found to remain stable over decades in children and adolescents.

Antibacterial properties and urease suppression ability of Lactobacillus inhibit the development of infectious urinary stones caused by Proteus mirabilis

Infectious urolithiasis is a type of urolithiasis, that is caused by infections of the urinary tract by bacteria producing urease such as Proteus mirabilis. Lactobacillus spp. have an antagonistic effect against many pathogens by secreting molecules, including organic acids. The aim of the study was to determine the impact of Lactobacillus strains isolated from human urine on crystallization of urine components caused by P. mirabilis by measuring bacterial viability (CFU/mL), pH, ammonia release, concentration of crystallized salts and by observing crystals by phase contrast microscopy. Moreover, the effect of lactic acid on the activity of urease was examined by the kinetic method and in silico study. In the presence of selected Lactobacillus strains, the crystallization process was inhibited. The results indicate that one of the mechanisms of this action was the antibacterial effect of Lactobacillus, especially in the presence of L. gasseri, where ten times less P. mirabilis bacteria was observed, compared to the control. It was also demonstrated that lactic acid inhibited urease activity by a competitive mechanism and had a higher binding affinity to the enzyme than urea. These results demonstrate that Lactobacillus and lactic acid have a great impact on the urinary stones development, which in the future may help to support the treatment of this health problem.

Carboxylated Pocoa polysaccharides inhibited oxidative damage and inflammation of HK-2 cells induced by calcium oxalate nanoparticles

The inhibitory effects of Chinese medicine Pocoa (PCPs) with different carboxyl group (-COOH) contents on oxidative damage and inflammatory response of renal epithelial cells and the influence of -COOH content in polysaccharides were investigated. HK-2 cell damage model was established by nanocalcium oxalate crystals (nanoCOM), and then PCPs with -COOH contents of 2.56% (PCP0), 7.48% (PCP1), 12.07% (PCP2), and 17.18% (PCP3) were used to protect the cells. PCPs could inhibit the damage of nanoCOM to HK-2 cells, increase cell viability, restore cytoskeleton and morphology, and improve lysosomal integrity. PCPs can reduce the oxidative stress response of nanoCOM to cells, inhibit the opening of mPTP and cell necrotic apoptosis, reduce the level of Ca2+ ions in cells, the production of ATP and MDA, and increase SOD expression. PCPs can also reduce the cellular inflammatory response caused by oxidative damage, and reduce the expression of nitric oxide (NO), inflammatory factors TNF-α, IL-6, IL-1β and MCP-1, as well as the content of inflammasome NLRP3. After protection, PCPs can inhibit the endocytosis of nanoCOM crystals by cells. With the increase in -COOH content in PCPs, its ability to inhibit nanoCOM cell damage, reduce oxidative stress, reduce inflammatory response, and inhibit crystal endocytosis increases, that is, PCP3 with the highest -COOH content, shows the best biological activity. Inhibiting cell damage and inflammation and reducing a large amount of endocytosis of crystals by cells are beneficial to inhibit the formation of kidney stones.

Substances Secreted by Lactobacillus spp. from the Urinary Tract Microbiota Play a Protective Role against Proteus mirabilis Infections and Their Complications

Proteus mirabilis urinary tract infections can lead to serious complications such as development of urinary stones. Lactobacillus spp., belonging to the natural microbiota of the urinary tract, exhibit a number of antagonistic mechanisms against uropathogens, including the secretion of organic acids. In this study, we determined the anti-adhesion, anti-cytotoxicity and anti-crystallization properties of the substances secreted by Lactobacillus. For this purpose, membrane inserts with a pore diameter 0.4 μm were used, which prevent mixing of cultured cells, simultaneously enabling the diffusion of metabolic products. The intensity of crystallization was assessed by measuring the levels of Ca2+, Mg2+ and NH3 and by observing crystals using microscopic methods. The cytotoxicity of the HCV-29 cell line was determined using the LDH and MTT assays, and the impact of lactobacilli on P. mirabilis adhesion to the bladder epithelium was assessed by establishing CFU/mL after cell lysis. It was shown that in the presence of L. gasseri the adhesion of P. mirabilis and the cytotoxicity of the cells decreased. The degree of crystallization was also inhibited in all experimental models. Moreover, it was demonstrated that L. gasseri is characterized by the secretion of a high concentration of L-lactic acid. These results indicate that L-lactic acid secreted by L. gasseri has a significant impact on the crystallization process and pathogenicity of P. mirabilis.

Gut Microbiota's Oxalate-Degrading Activity and Its Implications on Cardiovascular Health in Patients with Kidney Failure: A Pilot Prospective Study

Background and Objectives: The present study aims to investigate the association between gut microbiota's oxalate-degrading activity (ODA) and the risk of developing cardiovascular disease (CVD) over a three-year follow-up period in a cohort of patients undergoing kidney replacement therapy (KRT). Additionally, various factors were examined to gain insight into the potential mechanisms underlying the ODA-CVD link. Materials and Methods: A cohort of 32 KRT patients and 18 healthy volunteers was enrolled in this prospective observational pilot study. Total fecal ODA, routine clinical data, plasma oxalic acid (POx), serum indoxyl sulfate, lipid profile, oxidative stress, and proinflammatory markers were measured, and the patients were followed up for three years to assess CVD events. Results: The results revealed that patients with kidney failure exhibited significantly lower total fecal ODA levels compared to the healthy control group (p = 0.017), with a higher proportion showing negative ODA status (≤-1% per 0.01 g) (p = 0.01). Negative total fecal ODA status was associated with a significantly higher risk of CVD events during the three-year follow-up period (HR = 4.1, 95% CI 1.4-16.3, p = 0.003), even after adjusting for potential confounders. Negative total fecal ODA status was significantly associated with elevated POx and indoxyl sulfate levels and linked to dyslipidemia, increased oxidative stress, and inflammation, which are critical contributors to CVD. Conclusions: The findings contribute novel insights into the relationship between gut microbiota's ODA and cardiovascular health in patients undergoing KRT, emphasizing the need for further research to elucidate underlying mechanisms and explore potential therapeutic implications of targeting gut microbiota's ODA in this vulnerable population.

Sleep and circadian rhythm disturbance in kidney stone disease: a narrative review

The circadian rhythm generated by circadian clock genes functions as an internal timing system. Since the circadian rhythm controls abundant physiological processes, the circadian rhythm evolved in organisms is salient for adaptation to environmental change. A disturbed circadian rhythm is a trigger for numerous pathological events. Recently, accumulated data have indicated that kidney stone disease (KSD) is related to circadian rhythm disturbance. However, the mechanism between them has not been fully elucidated. In this narrative review, we summarized existing evidence to illustrate the possible association between circadian rhythm disturbance and KSD based on the epidemiological studies and risk factors that are linked to circadian rhythm disturbance and discuss some chronotherapies for KSD. In summary, KSD is associated with systemic disorders. Metabolic syndrome, inflammatory bowel disease, and microbiome dysbiosis are the major risk factors supported by sufficient data to cause KSD in patients with circadian rhythm disturbance, while others including hypertension, vitamin D deficiency, parathyroid gland dysfunction, and renal tubular damage/dysfunction need further investigation. Then, some chronotherapies for KSD were confirmed to be effective, but the molecular mechanism is still unclear.

Association between oxidative balance score and kidney stone in United States adults: analysis from NHANES 2007-2018

Purpose: To investigate the relationship between the Oxidative Balance Score (OBS) and kidney stone risk using NHANES 2007-2018 data, and to explore potential mechanisms and population-specific effects. Materials and methods: Data from the NHANES 2007-2018 were analyzed. OBS was calculated based on 16 dietary components and 4 lifestyle components. Multivariate logistic regression was employed to investigate the relationship between OBS and kidney stone. Further stratified analyses were conducted to examine the associations across different subgroups. Results: A total of 19,799 participants were included in the study. There was a consistent inverse association between OBS and the risk of kidney stones (OR = 0.97; 95% CI: 0.96-0.99). After dividing the participants into quartiles based on OBS, compared to the lowest quartile of OBS, the risk of kidney stones in the highest quartile of OBS was reduced by 33% (95% CI 0.50-0.89; p = 0.002). This association was consistent across both dietary and lifestyle OBS scores. The protective effect of OBS was notably pronounced among Non-Hispanic white and Other race groups, and among individuals with a higher level of education. However, the association was not significant among individuals with diabetes. Conclusion: A higher OBS, indicating a balance skewed towards antioxidants, is associated with a reduced risk of kidney stones, especially among specific population subgroups. These findings underscore the potential role of oxidative balance in kidney stone pathogenesis and highlight the importance of considering individual and population-specific factors in future research and preventive strategies.

Estrogen-induced signalling and the renal contribution to salt and water homeostasis

The kidney is considered to be one of the most estrogen-responsive, not reproductive organs in the body. Different estrogen receptors (ERs) show sex-specific differences in expression along the nephron and the expression of different ERs also changes with the estrous cycle of the female. The kidney becomes more estrogen-sensitive when estradiol levels are at their highest, just prior to ovulation. This review discusses the different mechanisms by which estradiol can modify the salt and water conservation processes of the kidney through transporter regulation to support the fluid and electrolyte homeostasis changes required in mammalian reproduction. The kidney plays a critical role in regulating blood pressure by controlling fluid homeostasis, and so protects the female cardiovascular system from dramatic changes in whole body fluid volume that occur at critical points in the human menstrual cycle and in pregnancy. This is augmented by the direct actions of estradiol on the cardiovascular system, for example through the direct stimulation of endothelial nitric oxide (NO) synthase, which releases NO to promote vasodilation. This and other mechanisms are less evident in the male and give women a degree of cardiovascular protection up until menopause, when the risks of cardiovascular disease and chronic kidney disease begin to match the risks experienced by males.

Melatonin alleviates intrarenal CaOx crystals deposition through inhibiting LPS-induced non-canonical inflammasome-mediated renal tubular epithelial cells pyroptosis

Urinary tract infection has long been considered a complication rather than etiology of calcium oxalate (CaOx) nephrolithiasis. This study aimed to explore the role of lipopolysaccharide (LPS), an important component of Gram-negative bacteria, on CaOx nephrolithiasis formation and antagonistic effect of melatonin. Male C57BL/6 mice were intraperitoneally injected with glyoxylate acid (80 mg/kg) daily for 7 days to construct CaOx nephrolithiasis model. A single dose of LPS (2.0 mg/kg) was given 2 h before the second glyoxylate acid treatment in the presence or absence of melatonin (25 mg/kg). Our results found that LPS promoted adhesion of CaOx crystals to renal tubular epithelial cells (RTECs) and intrarenal CaOx crystals deposition. Protein levels of cleaved Caspase-11, N-terminal of cleaved GSDMD (GSDMD-N), NOD-like receptor thermal protein domain associated protein 3 (NLRP3) and cleaved Caspase-1, several markers of non-classical inflammasome activation were upregulated in LPS-treated mouse kidneys and HK-2 cells. Moreover, the number of GSDMD pores was increased in LPS-treated HK-2 cell membrane. Melatonin inhibited Caspase-11 cleavage and antagonized the subsequent LPS-mediated upregulation of GSDMD-N, NLRP3 and cleaved Caspase-1 in kidney tissues and HK-2 cells. In addition, melatonin reduced membrane localization of GSDMD-N and the number of GSDMD pores in LPS-treated HK-2 cells. Accordingly, melatonin inhibited LPS-induced IL-1β and IL-18 in mouse serum and HK-2 culture supernatant. Importantly, melatonin alleviated LPS-induced crystal-cell interactions and intrarenal CaOx crystals deposition. We provide experimental evidence that LPS promoted CaOx nephrolithiasis formation by inducing non-canonical inflammasome-mediated RTECs pyroptosis. Melatonin alleviated CaOx nephrolithiasis formation through inhibiting LPS-induced non-canonical inflammasome-mediated RTECs pyroptosis.

Nur MA, Mohamed FY, Mohamud AK, Hassan J. The prevalence of urolithiasis in subjects undergoing computer tomography in selected referral diagnostic centers in Mogadishu, Somalia

Introduction and objectives

Somalia was predicted to be in the global stone belt with high urolithiasis prevalence. We aimed to determine the prevalence of urolithiasis and their demographic and computer tomography (CT) characteristics among subjects under CT scans in Mogadishu, Somalia. Materials and Methods: From March 2014 to November 2022, a total of 7,276 patients who underwent an abdominopelvic non-contrast CT scan for various indications were retrospectively reviewed. The mean age was 45.6 years with a standard deviation of 21.1 (range, 0.2-110 years). Patients were subdivided into two categories: adults (≥18 years) and pediatric (≤17 years).

Results

Of the 7,276 patients, 1,075 (14.8%) were diagnosed with urolithiasis. Among those with urolithiasis, 702 (65.3%) were male patients, and 373 (34.7%) were female patients. Among them, adults accounted for 92.7%, while children were 7.3%. Renal stones (nephrolithiasis) were the most common, representing 57% followed by ureteric stones at 35.5%, making upper urinary stones 92.5%. Approximately 70 patients (6.5%) had bladder stones; of these, 26 of them (37%) were accompanied by benign prostatic hyperplasia (BPH). There were 10 urethral stones (0.9%) recorded in the study, all were found in male patients, 8 localized in prostatic urethra, and 2 in the bulbar urethra. The overall mean stone size was 13.2 mm, and 60% of them ranged from 5 to 22 mm. Only 24% of the patients were asymptomatic. Single stones were almost 70%, while staghorn calculi were 8.2%. More than 60% of the patients with urolithiasis showed some degree of hydronephrosis ranging between mild to severe.

Conclusion

A CT scan-based urolithiasis prevalence indicates 14.8% in Mogadishu, Somalia, and these results are consistent with the probability calculation of the weights-of-evidence (WofE) methodology based on several risk factors including temperature, climate change, mineral deposit, drinking water quality, and distribution of carbonated rocks. Considering the high prevalence of the disease, Somalia needs to invest more in prevention and treatment facilities while also training urologists that are capable of utilizing minimally invasive techniques in the country.

The Gut-Organ Axis within the Human Body: Gut Dysbiosis and the Role of Prebiotics

The human gut microbiota (GM) is a complex microbial ecosystem that colonises the gastrointestinal tract (GIT) and is comprised of bacteria, viruses, fungi, and protozoa. The GM has a symbiotic relationship with its host that is fundamental for body homeostasis. The GM is not limited to the scope of the GIT, but there are bidirectional interactions between the GM and other organs, highlighting the concept of the "gut-organ axis". Any deviation from the normal composition of the GM, termed "microbial dysbiosis", is implicated in the pathogenesis of various diseases. Only a few studies have demonstrated a relationship between GM modifications and disease phenotypes, and it is still unknown whether an altered GM contributes to a disease or simply reflects its status. Restoration of the GM with probiotics and prebiotics has been postulated, but evidence for the effects of prebiotics is limited. Prebiotics are substrates that are "selectively utilized by host microorganisms, conferring a health benefit". This study highlights the bidirectional relationship between the gut and vital human organs and demonstrates the relationship between GM dysbiosis and the emergence of certain representative diseases. Finally, this article focuses on the potential of prebiotics as a target therapy to manipulate the GM and presents the gaps in the literature and research.

Giant Bladder stone and rectal prolapse complication in pediatric patient: Case report and literature review

INTRODUCTION AND IMPORTANCE

A giant bladder stone (BS) in the urinary tract system with a rectal prolapse complication is a rare urologic problem; it is even rarer in pediatric patients. In the case of bladder stone formation, a variety of steps result in a variety of stone compositions. This study aims to understand the rare disease course of a one-year-old patient with bladder and urethral stones and a rectal prolapse complication.

CASE PRESENTATION

A one-year-old boy presented with an inability to urinate since morning. It was a recurring incident for about a year but never resolved. The patients experienced irregular diarrhea and difficulty eating and drinking. Anal inspection revealed prolapse recti. The laboratory investigation found leukocytosis and anemia with normal blood urea nitrogen and creatinine. Urine tests revealed leukocyturia and hematuria. A plain radiograph of the abdomen showed a round opacity around the pelvic area. Ultrasonography of the abdomen and urinary tract revealed a giant BS and severe bilateral hydronephrosis. Thus, a cystolithotomy procedure was performed, and an additional urethral stone was found. Obtained bladder stones with a size of 30 × 21 × 15mm, with 57 % of uric acid and 33 % of calcium oxalate. A manual reduction of the prolapsed rectum was also performed during surgery. There was no recurrence of the prolapsed rectum after surgery.

CLINICAL DISCUSSION

BS is very rare in the pediatric population. The development of our case's stone composition starts with pure uric acid, which is later enveloped by calcium oxalate due to its lack of acidic atmosphere. Rectal prolapse occurs due to increased abdominal pressure caused by straining during urination.

CONCLUSION

The pathogenesis of BS is multifactorial, with local and systemic factors. Early diagnosis and comprehensive history-taking are essential for BS management decisions. The management of BS depends on its size, composition, and symptoms.

Establishment of a new predictive model for the recurrence of upper urinary tract stones

PURPOSE

To construct a nomogram for evaluation of the recurrence risk of upper urinary tract stones in patients.

METHODS

We retrospectively reviewed the clinical data of 657 patients with upper urinary tract stones and divided them into stone recurrence group and non-recurrence group. Blood routine, urine routine, biochemical, and urological CT examinations were searched from the electronic medical record, relevant clinical data were collected, including age, BMI, stones number and location, maximum diameter, hyperglycemia, hypertension, and relevant blood and urine parameters. The Wilcoxon rank-sum test, independent sample t test, and Chi-square test were used to preliminarily analyze the data of the two groups, then LASSO and logistic regression analysis were used to find out the significant difference indicators. Finally, R software was used to draw a nomogram to construct the model, and ROC curve was drawn to evaluate the sensitivity and specificity.

RESULTS

The results showed that multiple stones (OR: 1.832, 95% CI 1.240-2.706), bilateral stones (OR: 1.779, 95% CI 1.226-2.582), kidney stones (OR: 3.268, 95% CI 1.638-6.518), and kidney ureteral stones (OR: 3.375, 95% CI 1.649-6.906) were high risk factors. And the stone recurrence risk was positively correlated with creatinine (OR: 1.012, 95% CI 1.006-1.018), urine pH (OR: 1.967, 95% CI 1.343-2.883), Apo B (OR: 4.189, 95% CI 1.985-8.841) and negatively correlated with serum phosphorus (OR: 0.282, 95% CI 0.109-0.728). In addition, the sensitivity and specificity of the prediction model were 73.08% and 61.25%, diagnosis values were greater than any single variable.

CONCLUSION

The nomogram model can effectively evaluate the recurrence risk of upper urinary stones, especially suitable for stone postoperative patients, to help reduce the possibility of postoperative stone recurrence.

Oxalate (dys)Metabolism: Person-to-Person Variability, Kidney and Cardiometabolic Toxicity

Oxalate is a metabolic end-product whose systemic concentrations are highly variable among individuals. Genetic (primary hyperoxaluria) and non-genetic (e.g., diet, microbiota, renal and metabolic disease) reasons underlie elevated plasma concentrations and tissue accumulation of oxalate, which is toxic to the body. A classic example is the triad of primary hyperoxaluria, nephrolithiasis, and kidney injury. Lessons learned from this example suggest further investigation of other putative factors associated with oxalate dysmetabolism, namely the identification of precursors (glyoxylate, aromatic amino acids, glyoxal and vitamin C), the regulation of the endogenous pathways that produce oxalate, or the microbiota's contribution to oxalate systemic availability. The association between secondary nephrolithiasis and cardiovascular and metabolic diseases (hypertension, type 2 diabetes, and obesity) inspired the authors to perform this comprehensive review about oxalate dysmetabolism and its relation to cardiometabolic toxicity. This perspective may offer something substantial that helps advance understanding of effective management and draws attention to the novel class of treatments available in clinical practice.

Oxalate in Foods: Extraction Conditions, Analytical Methods, Occurrence, and Health Implications

Oxalate is an antinutrient present in a wide range of foods, with plant products, especially green leafy vegetables, being the main sources of dietary oxalates. This compound has been largely associated with hyperoxaluria, kidney stone formation, and, in more severe cases, systematic oxalosis. Due to its impact on human health, it is extremely important to control the amount of oxalate present in foods, particularly for patients with kidney stone issues. In this review, a summary and discussion of the current knowledge on oxalate analysis, its extraction conditions, specific features of analytical methods, reported occurrence in foods, and its health implications are presented. In addition, a brief conclusion and further perspectives on whether high-oxalate foods are truly problematic and can be seen as health threats are shown.

Exploring a Complex Interplay: Kidney-Gut Axis in Pediatric Chronic Kidney Disease

The human intestinal microbiota is a highly intricate structure with a crucial role in promoting health and preventing disease. It consists of diverse microbial communities that inhabit the gut and contribute to essential functions such as food digestion, nutrient synthesis, and immune system development. The composition and function of the gut microbiota are influenced by a variety of factors, including diet, host genetics, and environmental features. In pediatric patients, the gut microbiota is particularly dynamic and vulnerable to disruption from endogenous and exogenous factors. Recent research has focused on understanding the interaction between the gut and kidneys. In individuals with chronic kidney disease, there is often a significant disturbance in the gut microbiota. This imbalance can be attributed to factors like increased levels of harmful toxins from the gut entering the bloodstream, inflammation, and oxidative stress. This review looks at what is known about the link between a child's gut-kidney axis, how dysbiosis, or an imbalance in the microbiome, affects chronic kidney disease, and what treatments, both pharmaceutical and non-pharmaceutical, are available for this condition.

Calcineurin B inhibits calcium oxalate crystallization, growth and aggregation via its high calcium-affinity property

Calcineurin inhibitors (CNIs) are widely used in organ transplantation to suppress immunity and prevent allograft rejection. However, some transplant patients receiving CNIs have hypocitraturia, hyperoxaluria and kidney stone with unclear mechanism. We hypothesized that CNIs suppress activities of urinary calcineurin, which may serve as the stone inhibitor. This study aimed to investigate effects of calcineurin B (CNB) on calcium oxalate monohydrate (COM) stone formation. Sequence and structural analyses revealed that CNB contained four EF-hand (Ca2+-binding) domains, which are known to regulate Ca2+ homeostasis and likely to affect COM crystals. Various crystal assays revealed that CNB dramatically inhibited COM crystallization, crystal growth and crystal aggregation. At an equal amount, degrees of its inhibition against crystallization and crystal growth were slightly inferior to total urinary proteins (TUPs) from healthy subjects that are known to strongly inhibit COM stone formation. Surprisingly, its inhibitory effect against crystal aggregation was slightly superior to TUPs. While TUPs dramatically inhibited crystal-cell adhesion, CNB had no effect on this process. Ca2+-affinity assay revealed that CNB strongly bound Ca2+ at a comparable degree as of TUPs. These findings indicate that CNB serves as a novel inhibitor of COM crystallization, growth and aggregation via its high Ca2+-affinity property.

Characterizations of annexin A1-interacting proteins in apical membrane and cytosolic compartments of renal tubular epithelial cells

Annexin A1 (ANXA1) is a multifunctional calcium-binding protein that can bind to membrane phospholipids. Under high-calcium condition, ANXA1 expression increases on renal epithelial cell surface, leading to enhanced adhesion of calcium oxalate (CaOx) crystal (stone material) onto the cells. To regulate various cellular processes, ANXA1 interacts with many other intracellular protein partners. However, components of the ANXA1-interacting protein complex remain unclear. Herein, we characterized the interacting complexes of apical membrane (ApANXA1) and cytosolic (cyANXA1) forms of ANXA1 in apical membrane and cytosolic compartments, respectively, of renal epithelial cells under high-calcium condition using proteomic and bioinformatic approaches. After fractionation, the ApANXA1- and CyANXA1-interacting partners were identified by immunoprecipitation followed by nanoLC‑ESI‑Qq-TOF tandem mass spectrometry (IP-MS/MS). The ANXA1-interacting partners that were common in both apical membrane and cytosolic compartments and those unique in each compartment were then analyzed for their physico-chemical properties (molecular weight, isoelectric point, amino acid contents, instability index, aliphatic index, and grand average of hydropathicity), secondary structure (α-helix, β-turn, random coil, and extended strand), molecular functions, biological processes, reactome pathways and KEGG pathways. The data demonstrated that each set of these interacting proteins exhibited common and unique characteristics and properties. The knowledge from this study may lead to better understanding of the ApANXA1 and CyAXNA1 biochemistry and functions as well as the pathophysiology of CaOx kidney stone formation induced by high-calcium condition.

Determinants on urinary excretion of oxalate and other key factors related to urolithiasis among patients with chronic kidney disease: a single center study

PURPOSE

Urolithiasis is a known risk factor for chronic kidney disease (CKD). However, how CKD might affect the risk of incidence of urolithiasis is not widely studied.

METHODS

Urinary excretion of oxalate as well as other key factors related to urolithiasis was analyzed in a single center study of 572 patients with biopsy-proven kidney disease.

RESULTS

The mean age of the cohort was 44.9 years and 60% were males. The mean eGFR was 65.9 ml/min/1.73 m2. Median urinary excretion of oxalate was 14.7 (10.4-19.1) mg/24-h and associated with current urolithiasis (OR 12.744, 95% CI: 1.564-103.873 per one logarithm transformed unit of urinary oxalate excretion). Oxalate excretion was not associated with eGFR and urinary protein excretion. Oxalate excretion was higher in patients with ischemia nephropathy as compared with patients with glomerular nephropathy and tubulointerstitial nephropathy (16.4 vs 14.8 vs 12.0 mg, p = 0.018). And ischemia nephropathy (p = 0.027) was associated with urinary oxalate excretion on adjusted linear regression analysis. Urinary excretion of calcium and uric acid was correlated with eGFR and urinary protein excretion (all p < 0.001), with ischemia nephropathy and tubulointerstitial nephropathy associated with uric acid excretion (both p < 0.01) as well. Citrate excretion was correlated with eGFR (p < 0.001) on adjusted linear regression.

CONCLUSION

Excretion of oxalate and other key factors related to urolithiasis was differentially associated with eGFR, urinary protein, and pathological changes in CKD patients. The influence of these intrinsic traits of the underlining kidney disease should be considered when evaluating urolithiasis risk in patients with CKD.

SLC26 family: a new insight for kidney stone disease

The solute-linked carrier 26 (SLC26) protein family is comprised of multifunctional transporters of substrates that include oxalate, sulphate, and chloride. Disorders of oxalate homeostasis cause hyperoxalemia and hyperoxaluria, leading to urinary calcium oxalate precipitation and urolithogenesis. SLC26 proteins are aberrantly expressed during kidney stone formation, and consequently may present therapeutic targets. SLC26 protein inhibitors are in preclinical development. In this review, we integrate the findings of recent reports with clinical data to highlight the role of SLC26 proteins in oxalate metabolism during urolithogenesis, and discuss limitations of current studies and potential directions for future research.

Correlation of Great Chinese Famine Exposure During Early Life to Prevalence of Kidney Stone in Adulthood

Background

The Great Chinese Famine, as the famine of 1959-1961 was often known. Famine exposure during early life was proven to be associated with some kidney diseases but has not been studied with kidney stone. We aimed to investigate the relationship between exposure to the Great Chinese Famine in early life and the incidence of kidney stone in adulthood.

Methods

From 1 January 2017 to 31 December 2018, a total of 19,658 eligible adults were recruited in a cross-sectional survey who were born between 1 October 1952 and 30 September 1964 in Guangdong, China. Participants were separated into kidney stone and none-kidney stone groups based on kidney stone status. According to birth data, participants were divided into non-exposed, fetal-exposed, early-, mid-, and late-childhood-exposed groups. Multivariate logistic regression, subgroup analysis and interaction test were used to estimate the odds ratios (ORs) and confidence intervals (CIs) between famine exposure and kidney stone.

Results

In total, 19,658 (12,246 female, mean age 59.31 ± 3.68 years) subjects were enrolled, and 3219 (16.38%) participants with kidney stone. The prevalence of kidney in none-, fetal-, early-, mid-, and late-childhood-exposed groups were 645 (14.9%), 437 (15.9%), 676 (16.3%), 743 (17.0%), and 718 (17.6%), respectively (P<0.001). When compared with the unexposed group, the fully adjusted ORs for kidney stone from fetal-exposed, early-, mid- to late-childhood-exposed groups were 1.37 (95% CI: 1.13, 1.68, P=0.002), 1.98 (95% CI: 1.45, 2.72, P<0.001), 2.94 (95% CI: 1.96, 4.42, P<0.001), and 3.48 (95% CI: 2.11, 5.72, P<0.001), respectively (P for trend<0.001). Subgroup analyses revealed no interactions between the famine effect on kidney stones and body mass index, gender, smoking status, history of diabetes or hypertension (all P for interaction >0.05).

Conclusion

This study found that exposure to the Great Chinese Famine during early life was independently associated with the increased incidence of kidney stone in adulthood.

Integrated single-nucleus sequencing and spatial architecture analysis identified distinct injured-proximal tubular types in calculi rats

BACKGROUND

Urolithiasis with high prevalence and recurrence rate, has impacts on kidney injury in patients, becomes a socioeconomic and healthcare problem in worldwide. However, the biology of kidney with crystal formation and proximal tubular injury remains essentially unclear. The present study aims to evaluate the cell biology and immune-communications in urolithiasis mediated kidney injury, to provide new insights in the kidney stone treatment and prevention.

RESULTS

We identified 3 distinct injured-proximal tubular cell types based on the differentially expression injury markers (Havcr1 and lcn2) and functional solute carriers (slc34a3, slc22a8, slc38a3 and slc7a13), and characterized 4 main immune cell types in kidney and one undefined cell population, where F13a1^+/high/CD163^+/high monocyte & macrophage and Sirpa/Fcgr1a/Fcgr2a^+/high granulocyte were the most enriched. We performed intercellular crosstalk analysis based on the snRNA-seq data and explored the potential immunomodulation of calculi stone formation, and founded that the interaction between ligand Gas6 and its receptors (Gas6-Axl, Gas6-Mertk) was specifically observed in the injured-PT1 cells, but not injured-PT2 and -PT3 cells. The interaction of Ptn-Plxnb2 was only observed between the injured-PT3 cells and its receptor enriched cells.

CONCLUSIONS

Present study comprehensively characterized the gene expression profile in the calculi rat kidney at single nucleus level, identified novel marker genes for all cell types of rat kidney, and determined 3 distinct sub-population of injured-PT clusters, as well as intercellular communication between injured-PTs and immune cells. Our collection of data provides a reliable resource and reference for studies on renal cell biology and kidney disease.

Metabolic changes in kidney stone disease

Kidney stone disease (KSD) is one of the earliest medical diseases known, but the mechanism of its formation and metabolic changes remain unclear. The formation of kidney stones is a extensive and complicated process, which is regulated by metabolic changes in various substances. In this manuscript, we summarized the progress of research on metabolic changes in kidney stone disease and discuss the valuable role of some new potential targets. We reviewed the influence of metabolism of some common substances on stone formation, such as the regulation of oxalate, the release of reactive oxygen species (ROS), macrophage polarization, the levels of hormones, and the alternation of other substances. New insights into changes in substance metabolism changes in kidney stone disease, as well as emerging research techniques, will provide new directions in the treatment of stones. Reviewing the great progress that has been made in this field will help to improve the understanding by urologists, nephrologists, and health care providers of the metabolic changes in kidney stone disease, and contribute to explore new metabolic targets for clinical therapy.

Pediatric urolithiasis: what can pediatricians expect from radiologists?

The incidence of urolithiasis in children has increased over the two last decades. Urolithiasis formation results from urine oversaturation following insufficient water intake, urinary obstruction (notably in cases of congenital uropathies), excess production of an insoluble compound, or imbalance between crystallization promoters and inhibitors. Whereas most urolithiases in adults occur secondary to environmental factors, in children, secondary causes are far more frequent, and 15% are related to genetic causes, most often monogenic. This is especially true in recurrent forms, with early and rapid progression and bilateral stones, and in cases of familial history or consanguinity. Because of differing clinical management, one should rule out cystinuria, primary hyperoxaluria and renal tubular acidosis, among other causes of urolithiasis. As such, a complete biochemical evaluation must be performed in all cases of pediatric urolithiasis, even in cases of an underlying uropathy. Ultrasound examination is the first-line modality for imaging pediatric urolithiasis, allowing both diagnosis (urolithiasis and its complications) and follow-up. US examination should also explore clues to an underlying cause of urolithiasis. This review is focused on the role of imaging in the management and etiological assessment of pediatric urolithiasis. Radiologists play an important role in pediatric urolithiasis, facilitating diagnosis, follow-up and surgical management. A trio of clinicians (pediatric nephrologist, pediatric surgeon, pediatric radiologist) is thus necessary in the care of these pediatric patients.

Mineralogy, geochemistry, and micromorphology of human kidney stones (urolithiasis) from Mersin, the southern Turkey

This study describes the primary characteristics of the selected kidney stones surgically removed from the patients at the Mersin University Hospital in the southern Turkey and interprets their formation via petrographic, geochemical, XRD, SEM-EDX, and ICP-MS/OES analyses. The analytical results revealed that the kidney stones are composed of the minerals whewellite, struvite, hydroxyapatite, and uric acid alone or in different combinations. The samples occur in staghorn, bean-shaped composite, and individual rounded particle shapes, which are controlled by the shape of the nucleus and the site of stone formation. The cross-section of the samples shows concentric growth layers due to variations in saturation, characterizing the metastable phase. Kidney stone formation includes two main stages: (i) nucleation and (ii) aggregation and/or growth. Nucleation was either Randall plaque of hydroxyapatite in tissue on the surface of the papilla or a coating of whewellite on the plaque, or crystallization as free particles in the urine. Subsequently, aggregation or growth occurs by precipitation of stone-forming materials around the plaque or coating carried into the urine, or around the nucleus formed in situ in the urine. Urinary supersaturation is the main driving force of crystallization processes; and is controlled by many factors including bacterially induced supersaturation.

Renal Stones and Gallstones Correlated with the Ten-Year Risk Estimation of Atherosclerotic Cardiovascular Disease Based on the Pooled Cohort Risk Assessment of Males Aged 40–79

Background: The risk of developing atherosclerotic cardiovascular disease (ASCVD) is unknown for subjects with both gallstones and renal stones, nor is it known whether there is a difference in the risk between gallstones and renal stones. This study aimed to determine the risk relationship between gallstones and renal stones and the risk of ASCVD in a male population. Methods: We recruited 6371 eligible males aged 40 to 79 years old who did not have a documented ASCVD history. The ten-year ASCVD risk was calculated using the pooled cohort equations developed by the American College of Cardiology (ACC) and the American Heart Association (AHA). The ASCVD risk score was classified as a low risk (<7.5%), an intermediate risk (7.5% to 19.9%), or a high risk (≥20%). The diagnosis of gallstones and renal stones was established based on the results of abdominal sonography. Results: Both gallstones and renal stones were associated with a high level of intermediate risk (OR = 3.21, 95% CI = 1.89–5.49, p < 0.001) and high risk (OR = 3.01, 95% CI = 1.48–6.12, p < 0.001), compared to individuals with no stones at all, after adjusting for the effects of other clinical variables. The possession of gallstones was associated with a higher level of high ASCVD risk (OR = 1.84, 95% CI = 1.31–2.59, p < 0.05) than that of renal stones. Conclusions: The ASCVD risk was higher for males with gallstones than for those with renal stones. Men with both types of stones faced a risk of ASCVD that was three times higher than that of men without stones.

Update on the Effect of the Urinary Microbiome on Urolithiasis

Microbiota are ecological communities of commensal, symbiotic, and pathogenic microorganisms. The microbiome could be involved in kidney stone formation through hyperoxaluria and calcium oxalate supersaturation, biofilm formation and aggregation, and urothelial injury. Bacteria bind to calcium oxalate crystals, which causes pyelonephritis and leads to changes in nephrons to form Randall's plaque. The urinary tract microbiome, but not the gut microbiome, can be distinguished between cohorts with urinary stone disease (USD) and those without a history of the disease. In the urine microbiome, the role is known of urease-producing bacteria (Proteus mirabilis, Klebsiella pneumoniae, Staphylococcus aureus, Pseudomonas aeruginosa, Providencia stuartii, Serratia marcescens, and Morganella morganii) in stone formation. Calcium oxalate crystals were generated in the presence of two uropathogenic bacteria (Escherichia coli and K. pneumoniae). Non-uropathogenic bacteria (S. aureus and Streptococcus pneumoniae) exhibit calcium oxalate lithogenic effects. The taxa Lactobacilli and Enterobacteriaceae best distinguished the healthy cohort from the USD cohort, respectively. Standardization is needed in urine microbiome research for urolithiasis. Inadequate standardization and design of urinary microbiome research on urolithiasis have hampered the generalizability of results and diminished their impact on clinical practice.