Pathophysiology associated with forming urinary stones

Increased risk of upper tract urothelial carcinoma in patients with kidney stones: a large-scale analysis of the UK biobank

Kidney stone disease is a common and increasingly prevalent condition, with its incidence rising by 70% over the past two decades in the U.S. Lodgment of stones within the ureteral wall can cause urothelial injury, triggering inflammation, edema, and obstruction. Chronic inflammation has been linked to cancer development, contributing to tumorigenesis through cellular transformation, proliferation, invasion, angiogenesis, and metastasis. Studies suggest that recurrent nephrolithiasis can lead to a range of complications, including an increased risk of urinary tract cancer. This study investigates the association between kidney and ureteral stones and upper tract urothelial carcinoma (UTUC) risk using data from 502,144 individuals in the UK Biobank. We bidirectionally examined the presence of kidney stones and UTUC, applying a chi-square test to compute the odds ratio and assess statistical significance. A history of kidney stones was noted in 13,016 individuals, while 489,128 were stone-free. Among 511 UTUC cases, 50 had a history of kidney stones, whereas 461 were isolated UTUC. In contrast, 12,966 individuals had kidney stones without UTUC, and 488,667 were free of both conditions. Statistical analysis revealed an increased risk of UTUC in individuals with kidney stones [OR = 4.09 (95% CI 3.05-5.48), p < 0.001], indicating strong statistical significance. Our study demonstrates a fourfold increased risk of UTUC in individuals with a history of kidney stones. These findings highlight a significant association between kidney stones and UTUC, underscoring the need for further research on clinical management and cancer surveillance.

Unraveling the association of bacteria and urinary stones in patients with urolithiasis: an update review article

Urinary stone disease (USD) is a prevalent urological condition, ranking as one of the most common urinary tract disorders globally. Various risk factors influence the formation of kidney stones, and recent research indicates a rising prevalence of urolithiasis worldwide, particularly in developing countries. While the morbidity associated with urinary stones has decreased in recent years, long-term complications such as stone recurrence, kidney failure, and uremia continue to burden patients. Understanding the etiologies of urolithiasis, including the role of bacteria, is crucial as they can contribute to stone recurrence. The incidence of urinary tract infection (UTI) stones can be attributed to specific infectious risk factors, socio-demographic factors, and comorbid metabolic disorders. This review article explores the emerging evidence suggesting the involvement of bacteria in USD. It discusses the potential role of microorganisms in non-infection stones and highlights the association between UTIs and urolithiasis. Furthermore, it surveys the relationship between kidney stones and recurrent UTIs and the formation of bacterial biofilms in UTIs. Considering various risk factors, including biochemical stone analysis and the presence of bacteria, is essential for treating patients with infectious stones optimally. This review aims to provide an updated understanding of the association between bacteria and urinary stones in patients with urolithiasis, shedding light on the pathophysiology of urinary stone formation, urinary stone characteristics, and the urinary microbiome in urinary stones.

Antioxidant Activity of Auricularia auricula Polysaccharides with Different Molecular Weights and Cytotoxicity Difference of Polysaccharides Regulated CaOx to HK-2 Cells

Objective

This study aimed to investigate the growth of calcium oxalate (CaOx) crystals regulated by Auricularia auricular polysaccharides (AAPs) with different viscosity-average molecular weights (Mv), the toxicity of AAP-regulated CaOx crystals toward HK-2 cells, and the prevention and treatment capabilities of AAPs for CaOx stones.

Methods

The scavenging capability and reducing capacity of four kinds of AAPs (Mv of 31.52, 11.82, 5.86, and 3.34 kDa) on hydroxyl, ABTS, and DPPH free radicals and their capability to chelate divalent iron ions were detected. AAP-regulated CaOx crystals were evaluated by using zeta potential, thermogravimetric analysis, X-ray diffraction, and scanning electron microscopy. The cytotoxicity of AAP-regulated crystals was evaluated through examination of cell viability, cell death, malondialdehyde (MDA) content, and cell surface hyaluronic acid (HA) expression.

Results

The in vitro antioxidant activities of the four AAPs were observed in the following order: AAP0 < AAP1 < AAP2 < AAP3. Thus, AAP3, which had the smallest Mv, had the strongest antioxidant activity. AAPs can inhibit the growth of CaOx monohydrate (COM), induce the formation of CaOx dihydrate (COD), and reduce the degree of crystal aggregation, with AAP3 exhibiting the strongest capability. Cell experiments showed the lowest cytotoxicity in AAP3-regulated CaOx crystals, along with the lowest MDA content, HA expression, and cell mortality. In addition, COD presented less cytotoxicity than COM. Meanwhile, the cytotoxicity of blunt crystals was less than that of sharp crystals.

Conclusion

AAPs, particularly AAP3, showed an excellent antioxidative capability in vitro, and AAP3-regulated CaOx crystals presented minimal cytotoxicity.

Assessment of health equity consideration in Cochrane systematic reviews and primary studies on urolithiasis

Background and Aims

Health injustice is defined as "unnecessary, preventable, unjustified and unfair health differences." One of the most important scientific sources on the prevention and management of urolithiasis are Cochrane reviews in this field. Given that the first step in eliminating health injustice is to identify the causes, the aim of the present study was to evaluate equity considerations in Cochrane reviews and the included primary studies on urinary stones.

Methods

Cochrane reviews on kidney stones and ureteral stones were searched through the Cochrane Library. The included clinical trials in each of the reviews published after 2000 were also collected. Two different researchers reviewed all the included Cochrane reviews and primary studies. The researchers reviewed each PROGRESS criteria independently (P: place of residence, R: race/ethnicity/culture, O: occupation, G: gender, R: religion, E: education, S: socioeconomic status, S: social capital and networks). The geographical location of the included studies was categorized as low-income, middle-income and high-income countries, based on the World Bank income criteria. Each PROGRESS dimension was reported for both the Cochrane reviews and the primary studies.

Results

In total, 12 Cochrane reviews and 140 primary studies were included in this study. None of the included Cochrane reviews had specifically mentioned the PROGRESS framework in the Method section whereas gender distribution and place of residence were reported in two and one reviews, respectively. In 134 primary studies at least one item of PROGRESS was reported. The most frequent item was gender distribution, followed by place of residence.

Conclusion

According to the results of this study, the authors of Cochrane systematic reviews on urolithiasis, and researchers who have conducted such trials, have rarely considered health equity dimensions when designing and performing their studies. Therefore, researchers worldwide should be motivated to study populations from low-income countries with low socioeconomic status in addition to different cultures, ethnicities, and so forth. Furthermore, RCT reporting guidelines such as CONSORT should include health equity dimensions and the editors and reviewers of scientific journals should encourage researchers to further emphasize on health equity in their studies.

Recent Advances in Antimicrobial Coatings and Material Modification Strategies for Preventing Urinary Catheter-Associated Complications

In recent years, we have witnessed prominent improvements in urinary catheter coatings to tackle the commonly occurring catheter-associated urinary tract infection (CAUTI) in catheterized patients. CAUTIs are claimed to be one of the most frequent nosocomial infections that can lead to various complications, from catheter encrustation to severe septicaemia and pyelonephritis. Besides general prevention hygienic strategies, antimicrobial-coated urinary catheters show great potential in the prevention of urinary catheter-associated complications. The aim of this review is to present and evaluate recent updates on the development of antimicrobial urinary catheters in the context of the aetiology of urinary malfunction. Subsequently, we shed some light on future perspectives of utilizing 3D printing and the surrounding regulatory directions.