Major geogenic factors controlling geographical clustering of urolithiasis in China

Prevalence and related factors of nephrolithiasis among medical staff in Qingdao, China: a retrospective cross-sectional study

BACKGROUND

Certain occupations may predispose individuals to urolithiasis, a multi-factorial disease. The study aimed to evaluate the prevalence and related factors of nephrolithiasis in medical staff in Qingdao, China.

METHODS

Physical examination results of 5115 in-service medical staff aged 22-60 years old were retrospectively analyzed. Multivariable logistic regression analysis and stratified analyses by age and gender were applied to explore the related factors of nephrolithiasis in these medical staff.

RESULTS

The overall nephrolithiasis prevalence in medical staff in Qingdao, China was 4.65%. Doctors were more prone to nephrolithiasis than nurses (5.63% vs. 3.96%, P = 0.013) and the peak prevalence (6.69%) was observed in medical staff working in the emergency department (ED). Male gender (OR = 1.615, 95% CI = 1.123-2.323, P = 0.010), overweight or obesity (OR = 1.674, 95% CI = 1.266-2.214, P < 0.001), work seniority ≥ 10 years (OR = 2.489, 95%CI = 1.675-3.699, P < 0.001) and working in the ED (OR = 1.815, 95% CI = 1.202-2.742, P = 0.005) were independent predictors for nephrolithiasis in medical staff based on the results of multivariate logistic regression analysis. The associations between overweight or obesity and nephrolithiasis risk as well as between work seniority ≥ 10 years and nephrolithiasis risk in medical staff were independent of age or gender in stratified analysis.

CONCLUSIONS

Nephrolithiasis prevalence in medical staff in Qingdao, China seemed not to be higher than that in the general population. Medical staff with work seniority ≥ 10 years and working in the ED should pay abundant attention to take measures to modify their nephrolithiasis risk.

Oxalate regulates crystal-cell adhesion and macrophage metabolism via JPT2/PI3K/AKT signaling to promote the progression of kidney stones

Oxalate is an organic dicarboxylic acid that is a common component of plant foods. The kidneys are essential organs for oxalate excretion, but excessive oxalates may induce kidney stones. Jupiter microtubule associated homolog 2 (JPT2) is a critical molecule in Ca2+ mobilization, and its intrinsic mechanism in oxalate exposure and kidney stones remains unclear. This study aimed to reveal the mechanism of JPT2 in oxalate exposure and kidney stones. Genetic approaches were used to control JPT2 expression in cells and mice, and the JPT2 mechanism of action was analyzed using transcriptomics and untargeted metabolomics. The results showed that oxalate exposure triggered the upregulation of JPT2, which is involved in nicotinic acid adenine dinucleotide phosphate (NAADP)-mediated Ca2+ mobilization. Transcriptomic analysis revealed that cell adhesion and macrophage inflammatory polarization were inhibited by JPT2 knockdown, and these were dominated by phosphatidylinositol 3-kinase (PI3K)/AKT signaling, respectively. Untargeted metabolomics indicated that JPT2 knockdown inhibited the production of succinic acid semialdehyde (SSA) in macrophages. Furthermore, JPT2 deficiency in mice inhibited kidney stones mineralization. In conclusion, this study demonstrates that oxalate exposure facilitates kidney stones by promoting crystal-cell adhesion, and modulating macrophage metabolism and inflammatory polarization via JPT2/PI3K/AKT signaling.

Prevalence of urolithiasis in China: a systematic review and meta-analysis

OBJECTIVE

To estimate the pooled prevalence, as well as the spatial and temporal distribution, of urolithiasis among subjects in China.

MATERIALS AND METHODS

We conducted a comprehensive search of both Chinese and English databases to retrieve literature pertaining to the prevalence of urolithiasis in the indigenous Chinese population. A random-effects meta-analysis model was employed to calculate the pooled prevalence of urolithiasis. Subgroup analyses were conducted based on factors such as time, region, gender, and sample size. Prevalence and spatial distribution maps were created based on provinces and latitude/longitude coordinates.

RESULTS

A total of 46 studies conducted in 22 provinces across China were included in this meta-analysis and the pooled prevalence of urolithiasis, kidney stones, ureteric calculi, urethral and bladder stones were 8.1% (95% confidence interval [CI] 5.6-11.1%), 7.8% (95% CI 5.8-10.0%), 3.2% (95% CI 0.6-5.7%), 0.5% (95% CI 0.1-0.9%). Most of the urolithiasis prevalence screening in China was concentrated between 100° E and 120° E, with higher rates observed in low latitude areas. Subgroup analysis of kidney stones revealed that Guangdong (12.7%) and Guangxi (10.3%) had the highest prevalence, with the eastern developed area exhibiting higher rates compared to the west. The prevalence in males was higher than in females (odds ratio 1.67, 95% CI 1.46-1.92), although the gender gap has significantly reduced since 2006. Moreover, a greater sample size is associated with a decreased prevalence of urolithiasis.

CONCLUSIONS

The prevalence of urolithiasis is increasing in China, and there are noteworthy regional or provincial disparities in occurrence. It is worth noting that the current number of screening studies in some areas is insufficient. Additional investigations with appropriate sample sizes should be supplemented in time.

Therapeutic effects of Chinese herbal medicines for treatment of urolithiasis: A review

Urolithiasis is a common and complex disease of the urinary system, which can cause urinary tract blockage, urinary tract infection, and even damage to urinary system-related tissues. Although urolithiasis can be cured, its high recurrence rate and the development of chronic kidney disease in some patients have drawn the attention of nephrologists. Although the application of extracorporeal lithotripsy, percutaneous nephrolithotomy and other minimally invasive techniques have made the treatment of urolithiasis more efficient, pharmacotherapy plays an indispensable role in reducing their morbidity and recurrence rates. Traditional Chinese medicine (TCM) has been used for treatment and prevention of urolithiasis in developing countries for centuries, known for its unquestionable efficacy and safety. This article reviews the progress of clinical trials and pharmacological studies on the treatment of urolithiasis with Chinese herbal medicines (CHMs). The mechanism of CHMs in the treatment of urolithiasis mainly involve preventing further growth and aggregation of urolithiasis, reducing the PH of urine, promoting calculus dissolution. Furthermore, some CHMs can increase urine output, relax smooth muscles, and promote the removal of calculus. These findings provide new treatment strategies and options for urolithiasis and secondary kidney damage.

Flexible ureteroscopy under local anesthesia for stone management: initial exploration and two-year experience

BACKGROUND

Flexible ureteroscopy (f-URS) is a minimally invasive surgical technique used for treating urinary tract stones. While general anesthesia (GA) is the standard method used, it comes with risks. Local anesthesia (LA) is a safer and more cost-effective alternative to GA, and its use in f-URS could potentially reduce patients' risks and increase accessibility to treatment. This study aims to investigate the feasibility, safety, and efficacy of using LA for f-URS in treating stones, as an initial experience in the diagnosis related group (DRG) era of China.

METHODS

Patients who met the inclusion and exclusion criteria and were continuously included in the study Between 2021 and 2023. We analyzed the stone free status, postoperative complication rate, hospitalization costs, and presented key points of the procedure performed under LA that we had summarized over the past two years.

RESULTS

A study of 614 patients undergoing f-URS under LA for urinary stones in our hospital showed 83.4% stone-free rate with a mean operative time of 44.12 ± 16.63 minutes; 18 patients experienced fever postoperatively, and 12 had ureteral injuries. No severe complication was reported. The cost of LA was found to be only 1.7% of the DRG payment, which is around $40. The highest VAS scores were observed during the sheath insertion, with STAI scores decreasing during and after surgery.

CONCLUSIONS

The study revealed that f-URS administered under LA was a well-tolerated, efficient, safe, and economical procedure. In the DRG era, this new anesthetic option for f-URS provides urologists with a more cost-effective alternative.

Nanocrystal-induced chronic tubular-nephropathy in tropical countries: diagnosis, mitigation, and eradication

In tropical countries, a mysterious tubulo-interstitial chronic renal disease (CKD), unrelated to diabetes, hypertension, and immunological causes, manifested four decades ago. Approximately 25,000 primarily middle-aged male farmers succumb annually to this crystal-tubular nephropathy (CTN). Without any known causative factors, it was identified as CKD of unknown aetiology (CKDu). Because multiple factors contribute to causing it later, was changed to CKD of multi-factorial (CKDmfo). Despite no evidence, it was hypothesised to cause by agrochemicals or heavy metals in food or drinking contaminated water. However, current data suggest that the CKD-CTN is due to natural geogenic water contamination. Consumption of concentrated stagnant groundwater from deep-dug wells and tube wells containing hard water and fluoride, overdecades is necessary for its clinical manifestations. In all affected countries have prolonged annual dry seasons that led to the evopo-concentration of ions and minerals in groundwater, making hard water even more unpalatable, thus, peasants consume lesser amounts of water. They develop chronic dehydration from daily exposure to hot climatic conditions aggravated by regular alcohol intake. These conditions provide a highly conducive environment-a perfect storm for calcium phosphate (CaPO₄) crystal formation in renal tissues. Our recent histological and preliminary electron microscopic data reveal deposition of CaPO₄ crystals and nano-tubes in kidneys. While CaPO₄ nano-minerals are unstable, the presence of fluoride ions stabilises and allows their growth. This new concept paves the path for highly cost-effective, straightforward local solutions to protect farm workers and eliminate the disease, without embarking on expensive medications, interventions, or building hospitals. Chronic dehydration-associated CKD-CTN is preventable by increased consumption of potable water. Increasing clean water consumption reduces CKD-CTN incidence, and associated morbidities and premature deaths. However, the damage becomes irreversible when the disease advances beyond CKD stage IIIB. The incidence of this deadly renal failure can be prevented by its education, lifestyle changes, and increased water consumption, not by treating the renal disease or expanding dialysis centres/hospitals, or transplantation services. Eradication of CKD-CTN cost significantly less than the current approach of treating affected persons and unnecessarily expanding health infrastructure. Since the manifestation of CKD-CTN is due to consuming naturally contaminated drinking water (with calcium containing hard water and fluoride), it is not difficult to remove these to prevent CKD-CTN: thus, international assistance is unwarranted for its eradication. The straightforward approaches described here will prevent CKD-CTN and save thousands of lives in affected farming communities.

Metal ions-regulated chemical vapor generation of Hg2+:mechanism and application in miniaturized point discharge atomic emission spectrometry assay of oxalate in clinical urolithiasis samples

It is well known that the coexisting metal ions could significantly influence the atomic spectroscopy (AS) analysis. In this work, a cation-modulated mercury ions (Hg²⁺) strategy via chemical vapor generation (CVG) was developed for oxalate assay due to the phenomenon that the Ag ⁺ can significantly reduce the Hg²⁺ signal. The regulation effect was studied in depth via experimental investigations. Since Ag ⁺ can be reduced to silver nanoparticles (Ag NPs) by reductant SnCl₂, the decrease of the Hg²⁺ signal is attributed to the formation of a silver-mercury (Ag-Hg) amalgam. Due to the oxalate can react with Ag ⁺ to generate Ag₂C₂O₄, which can reduce the generation of Ag-Hg amalgam, a portable and low-power point discharge chemical vapor generation atomic emission spectrometry (PD-CVG-AES) system was constructed to quantify the content of oxalate via monitoring the signal of Hg²⁺. Under optimal conditions, the limit of detection (LOD) was as low as 40 nM in the range of 0.1-10 μM for oxalate assay, while exhibiting good specificity. This method was applied to quantitative oxalate in 50 clinical urine samples of urinary stones patients. The levels of oxalate detected in clinical samples were consistent with clinical imaging results, which is promising for point-of-care testing in clinical diagnosis.

Calcium and magnesium in China's public drinking water and their daily estimated average requirements

Calcium (Ca) and magnesium (Mg) in drinking water and the relevant health effects have been ignored for too long. This study aims to reveal the concentrations, spatial distributions, origins and contributions to the daily estimated average requirements of Ca and Mg in public drinking water. Using hydrochemical data of collected samples of public drinking water in 314 cities across China, the contributions of Ca and Mg intakes from public drinking water to their daily estimated average requirements (EARs) were assessed. And the significance of Ca/Mg ratio and total hardness (TH) was evaluated as well. The Ca and Mg concentrations of the samples were in the range of 2.5-155.1 mg/L and 0.2-81.9 mg/L, with an average of 40.4 mg/L and 12.4 mg/L, respectively. There exist obvious differences in Ca and Mg concentrations in different regions, under the impact of climate conditions and water-rock interactions. The intake of Ca via the consumption of public drinking water for adults may be twice as much as that for other age groups. In cities with high Ca levels in public drinking water, the Ca contributions to EAR could reach up to 51.59% for adults. By contrast, Mg in drinking water is an important and even the main pathway to ingest Mg for infants and children. Therefore, public drinking water is critical for Ca and Mg intake among urban residents of China. Besides, attention should be paid to the health effects of high Ca/Mg ratio and low TH in public drinking water, especially in southern China. This research is the first systematic and comprehensive national scale study of Ca and Mg in public drinking water and can provide an important reference to improve healthy public drinking water standards around the world.

Extreme temperature exposure and urolithiasis: A time series analysis in Ganzhou, China

Background

Ambient temperature change is a risk factor for urolithiasis that cannot be ignored. The association between temperature and urolithiasis varies from region to region. Our study aimed to analyze the impact of extremely high and low temperatures on the number of inpatients for urolithiasis and their lag effect in Ganzhou City, China.

Methods

We collected the daily number of inpatients with urolithiasis in Ganzhou from 2018 to 2019 and the meteorological data for the same period. The exposure-response relationship between the daily mean temperature and the number of inpatients with urolithiasis was studied by the distributed lag non-linear model (DLNM). The effect of extreme temperatures was also analyzed. A stratification analysis was performed for different gender and age groups.

Results

There were 38,184 hospitalizations for urolithiasis from 2018 to 2019 in Ganzhou. The exposure-response curve between the daily mean temperature and the number of inpatients with urolithiasis in Ganzhou was non-linear and had an observed lag effect. The warm effects (30.4°C) were presented at lag 2 and lag 5-lag 9 days, and the cold effects (2.9°C) were presented at lag 8 and lag 3-lag 4 days. The maximum cumulative warm effects were at lag 0-10 days (cumulative relative risk, CRR = 2.379, 95% CI: 1.771, 3.196), and the maximum cumulative cold effects were at lag 0-5 (CRR = 1.182, 95% CI: 1.054, 1.326). Men and people between the ages of 21 and 40 were more susceptible to the extreme temperatures that cause urolithiasis.

Conclusion

Extreme temperature was correlated with a high risk of urolithiasis hospitalizations, and the warm effects had a longer duration than the cold effects. Preventing urolithiasis and protecting vulnerable people is critical in extreme temperature environments.

Seasonal variation in the detection rate and all-cause in-hospital mortality of AKI in China: A nationwide cohort study

Background

Acute kidney injury (AKI) is a severe clinical syndrome that places a massive burden on medical systems worldwide, yet the seasonality of AKI remains unexplored in China. The aim of this study was to describe the seasonal variation in the detection rate and all-cause in-hospital mortality of AKI in China based on a nationwide cohort study.

Methods

This was a retrospective cohort recruiting a national sample of 7,291 adult patients treated in hospitals in 22 provinces of mainland China during January or July 2013. AKI was defined according to the 2012 Kidney Disease Improving Global Outcomes AKI creatinine criteria or expanded criteria of increase or decrease in serum creatinine level of 50% during the hospital stay. The seasonal group was determined according to the corresponding admission date for each patient. The detection rate of AKI refers to the ratio of identified AKI cases to the total number of adult admissions from the same regional or seasonal group.

Results

Both the detection rate (2.31 vs. 2.08%, p = 0.001) and in-hospital mortality rate (13.3 vs. 10.7%, p = 0.001) of AKI were higher in winter than in summer. The patients with AKI detected in winter had higher proportions of prehistory diseases, cardiac or vascular kidney injury factors, and severe comorbidities than those in summer (all p < 0.05). In the multivariable analysis, winter was an independent risk factor for in-hospital mortality of patients with AKI [odds ratio (OR) = 1.22, 95% confidence interval (CI), 1.03-1.44, p = 0.02] after adjusting for demographic factors, medical history, comorbidity, and climatic confounders. Higher ambient temperature (OR = 0.91, 95% CI, 0.86-0.97, p = 0.002, per 10°C increase), higher relative humidity level (OR = 1.14, 95% CI, 1.04-1.25, p = 0.005, per 10% increase), and living in temperate continental region (OR = 2.18, 95% CI, 1.63-2.91, p < 0.001) were each independently associated with in-hospital mortality.

Conclusion

The detection rate and all-cause in-hospital mortality of AKI showed a winter predominance in patients with AKI in China. Winter appeared to be an independent risk factor for all-cause in-hospital mortality in patients with AKI. Environmental factors, including lower ambient temperature, higher relative humidity level, and living in temperate continental climatic regions, were each independently associated with increased risks of in-hospital mortality in patients with AKI.

The effect of preoperative urine culture and bacterial species on infection after percutaneous nephrolithotomy for patients with upper urinary tract stones

To study the relationship between preoperative urine culture, bacterial species and infection after percutaneous nephrolithotomy in patients with upper urinary tract stones, and summarize the clinical characteristics of different bacterial infections. From January 2014 and January 2020, 963 patients with upper urinary tract stones who underwent PCNL in the department of urology of Fujian provincial hospital were included in the study. Information included the patient’s age, gender, weight, diabetes, chronic disease history, urine routine, preoperative urine culture results, stone size, number of stones, hydronephrosis level, operation time, body temperature, heart rate, blood pressure, breathing rate, hemoglobin, serum creatinine, bilirubin, platelets and whether there was preoperative infection were recorded. 141 patients (14.6%) had a positive urine culture before surgery, and 7 of them had multiple bacterial infections. The most common pathogenic bacteria was Escherichia coli, followed by Enterococcus and Klebsiella pneumoniae. A total of 74 cases (7.7%) of 963 patients with infection after PCNL occurred, 24 cases (32.4%) of infected patients progressed to urinary septic shock. Univariate analysis shown that the probability of infection in patients with long operation time and positive urine culture was significantly higher, and the difference was statistically significant. Further multivariate logistic regression analysis shown that positive urine culture before operation and long operation time were independent risk factors for infection after PCNL. Among the 29 patients with septic shock, 18 cases (62.1%) had a positive urine culture before surgery. The incidence (43.9%) of postoperative infection in Escherichia coli positive patients was significantly higher than that in the negative group, and the difference was statistically significant. The rate of patients with Escherichia coli infection progressing to septic shock was 9 cases (60%). 2 patients with Enterococcus faecium infection and 2 patients with Klebsiella pneumoniae infection all progressed to septic shock. The age of patients with post-PCNL infection caused by Escherichia Coli, Enterococcus faecium and Klebsiella pneumoniae were 58.53 ± 11.73 years, 76.5 years and 74 years.The body temperature of patients with post-PCNL infection caused by Escherichia Coli, Enterococcus faecium and Klebsiella pneumoniae were 39.10 ± 0.25 °C, 39.45 °C and 38.65 °C. The highest pct value of patients with post-PCNL infection caused by Escherichia Coli, Enterococcus faecium and Klebsiella pneumoniae were 80.62 ± 31.45 ng/mL, 24.32 ng/mL and 8.45 ng/mL. The nitrite positive rate of patients with post-PCNL infection caused by Escherichia Coli, Enterococcus faecium and Klebsiella pneumoniae were 64.51%, 16.6% and 0. Postoperative infection of PCNL is significantly correlated with positive preoperative urine culture, and positive preoperative urine culture is an independent risk factor for postoperative infection. The most common pathogen of postoperative infection of PCNL is Escherichia coli, followed by Enterococcus and Klebsiella pneumoniae. Patients with Escherichia coli infection are often positive for nitrite before surgery, mainly manifested by high fever, and PCT is significantly increased (often exceeded 100 ng/ml). Enterococcus faecium and Klebsiella pneumoniae infections mostly occur in elderly patients and often progress to septic shock. Patients with Enterococcus faecium infection have a high fever, and the PCT value is significantly higher (often exceeded 20 ng/ml). Patients with Klebsiella pneumoniae infection have a moderate fever, and the PCT value generally does not exceeded 10 ng/ml. Long operation time is another independent risk factor for PCNL infection.

Nomograms for Predicting the Risk of SIRS and Urosepsis after Uroscopic Minimally Invasive Lithotripsy

Objective. To analyze the potential risk factors that affect the development of urosepsis following uroscopic minimally invasive lithotripsy and to develop a nomogram that predicts the probability of postoperative urosepsis. Methods. We retrospectively analyzed the clinical data from patients that underwent percutaneous nephrolithotripsy (PCNL) or ureteroscopic lithotripsy (URL) between January 2018 and December 2019. The enrolled patients were grouped twice according to systemic inflammatory response syndrome (SIRS) and quick sequential organ failure assessment (qSOFA). After univariate and multivariate logistic regression analyses, we identified the independent predictive factors affecting the development of postoperative SIRS and urosepsis, and built the nomograms. Results. From January 2018 to December 2019, 1959 patients underwent PCNL or URL, of whom 236 patients were accorded with the inclusion criteria. Of all 236 patients, 64 (27.12%) patients developed postoperative SIRS, and 17 (7.20%) patients developed postoperative urosepsis. Multivariate logistic regression analysis showed that positive preoperative urine culture (PUC+) ( $\text{OR}=2.331$ , $P=0.044$ ), procalcitonin (PCT) ( $\text{OR}=1.093$ , $P=0.037$ ), C-reactive protein (CRP) ( $\text{OR}=1.017$ , $P<0.001$ ), and neutrophil ratio (NEUT%) ( $\text{OR}=1.091$ , $P=0.004$ ) of postoperative were independent predictors of SIRS, and PCT ( $\text{OR}=1.017$ , $P=0.003$ ) and CRP ( $\text{OR}=1.080$ , $P<0.001$ ) were independent predictors of urosepsis. Additionally, the nomograms demonstrated good accuracy in predicting SIRS and urosepsis with a C-index of 0.884 (95% CI: 0.835-0.934) and 0.941 (95% CI: 0.885-0.996), respectively. Conclusions. The nomograms achieved the prediction of SIRS and urosepsis after uroscopic minimally invasive lithotripsy. Using this model, the risk of SIRS or urosepsis for an individual patient can be determined, which facilitates early diagnosis and rational treatment.

Epidemiological trends of urinary tract infections, urolithiasis and benign prostatic hyperplasia in 203 countries and territories from 1990 to 2019

BACKGROUND

Urinary tract infections (UTI), urolithiasis, and benign prostatic hyperplasia (BPH) are three of the most common nonmalignant conditions in urology. However, there is still a lack of comprehensive and updated epidemiological data. This study aimed to investigate the disease burden of UTI, urolithiasis, and BPH in 203 countries and territories from 1990 to 2019.

METHODS

Data were extracted from the Global Burden of Disease 2019, including incident cases, deaths, disability-adjusted life-years (DALYs) and corresponding age-standardized rate (ASR) from 1990 to 2019. Estimated annual percentage changes (EAPC) were calculated to evaluate the trends of ASR. The associations between disease burden and social development degrees were analyzed using a sociodemographic index (SDI).

RESULTS

Compared with 1990, the incident cases of UTI, urolithiasis, and BPH increased by 60.40%, 48.57%, and 105.70% in 2019, respectively. The age-standardized incidence rate (ASIR) of UTI increased (EAPC = 0.08), while urolithiasis (EAPC = - 0.83) and BPH (EAPC = - 0.03) decreased from 1990 to 2019. In 2019, the age-standardized mortality rate (ASMR) of UTI and urolithiasis were 3.13/100,000 and 0.17/100,000, respectively. BPH had the largest increase (110.56%) in DALYs in the past three decades, followed by UTI (68.89%) and urolithiasis (16.95%). The burden of UTI was mainly concentrated in South Asia and Tropical Latin America, while the burden of urolithiasis and BPH was recorded in Asia and Eastern Europe. Moreover, the ASIR and SDI of urolithiasis in high-SDI regions from 1990 to 2019 were negatively correlated, while the opposite trend was seen in low-SDI regions. In 2019, the ASIR of UTI in females was 3.59 times that of males, while the ASIR of urolithiasis in males was 1.96 times higher than that in females. The incidence was highest in the 30-34, 55-59, and 65-69 age groups among the UTI, urolithiasis, and BPH groups, respectively.

CONCLUSION

Over the past three decades, the disease burden has increased for UTI but decreased for urolithiasis and BPH. The allocation of medical resources should be based more on the epidemiological characteristics and geographical distribution of diseases.

Aggregation of Nanochemical Microcrystals in Urine Promotes the Formation of Urinary Calculi

With the increasing incidence and recurrence rate of urinary calculi, urinary calculi have become a serious health risk, and the research on urinary calculi has become the focus of public attention. At present, the research results on the formation mechanism of urinary calculi are not ideal, and there is no unified conclusion. In order to further study the influencing factors of the formation of urinary calculi and provide new ideas for the prevention and clinical treatment of urinary calculi, the influence of agglomeration of nanochemical microcrystals in urine on urinary calculi was studied in this paper. In this study, fresh morning urine was collected from 10 urological stone patients and 10 healthy controls without urological stone in the urology department of a hospital. After processing the experimental specimens, we first use flame atomic absorption spectrometry and alcian blue colorimetric method to detect the content of Ca2+ and citrate in the urine and then use the nanoparticle size analyzer to detect the microcrystals in the urine. Diameter, distribution, degree of aggregation and potential, and finally HRTEM observation to observe the morphology, chemical composition, and element composition of the nanocrystals. The results showed that the content of Ca2+ and lemon hydrochloric acid in the urine of the experimental group was lower than that of the control group. The particle size of the nanocrystals increased with the increase in the pore size of the membrane. The average particle size of the experimental group increased gradually from 163 ± 31 nm to 3219 ± 863 nm, while the average particle size of the control group increased from 183 ± 65 nm to 997 ± 522 nm. The mean value of the potential decreased with the increase in the pore size of the filter membrane. The change amplitude of the experimental group was 6.57 mV, while the change amplitude of the control group was only 1.75 mV. In the composition of nanocrystals, element O accounts for the most, accounting for 42.54% of all elements. This indicates that the aggregation of nanocrystals in urine will lead to the rapid increase in the size of nanocrystals, which will eventually lead to the formation of stones.

Assessment of the impact of geogenic and climatic factors on global risk of urinary stone disease

Urinary Stone Disease (USD) or urolithiasis has plagued humans for centuries, and its prevalence has increased over the past few decades. Although USD pathology could vary significantly among individuals, previous qualitative assessments using limited survey data demonstrated that the prevalence of USD might exhibit a distinctive geographical distribution (the so-called "stone belt"), without any knowledge about the characteristics and contribution factors of the belt. Here, we argue that the spatial distribution of USD can at least partly be explained by geogenic and climatic factors, as it correlates with the ambient geo-environmental conditions modulated by lithology/mineralogy, water quality and climate. Using a Bayesian risk model, we assessed the global risk of USD based on updated big data of four key geogenic factors: phosphorite mines (inventory >1600 points), carbonate rocks (at the scale of 1:40 million), Ca²⁺/Mg²⁺ molar ratio of river water (1.27 million samples distributed over 17,000 sampling locations), and mean air temperature (0.5^o × 0.5° resolution) representing the climate. We quantitatively identified possible contributions of the factors to USD and delineated the regions with the high USD risk which stretched from southern North America, via the Mediterranean region, northeastern Africa, southern China to Australia, and roughly coincide with the world's major areas of carbonate outcropping. Under current climate conditions, the areas with the probabilities for the USD prevalence of ≥50% and ≥30% covered 3.7% and 20% of the Earth's land surface, respectively. By the end of the 21st century, such total areas could rise to 4.4% and 25% as a result of global warming. Since the USD data used in this study were quite heterogeneous, the prediction results needed further calibration with additional high-quality prevalence data in the future.

Oxidative stress and endoplasmic stress in calcium oxalate stone disease: the chicken or the egg?

Crystal modulators play a significant role in the formation of calcium oxalate stone disease. When renal cells are subjected to oxalate stress, the loss in cell integrity leads to exposure of multiple proteins that assist and/or inhibit crystal attachment and retention. Contact between oxalate and calcium oxalate with urothelium proves fatal to cells as a result of reactive oxygen species generation and onset of oxidative stress. Hence, as a therapeutic strategy it was hypothesised that supplementation of antioxidants would suffice. On the contrary to popular belief, the detection of oxalate induced endoplasmic reticulum mediated apoptosis proved the ineffectiveness of antioxidant therapy alone. Thus, the inadequacy of antioxidant supplementation in oxalate stress invoked the presence of an alternative pathway for the induction of kidney fibrosis in hyperoxaluric rats. In addition to settling this query, the link between oxidative stress and ER stress is not well understood, especially in urolithiasis.

The Urological Association of Asia clinical guideline for urinary stone disease

The Urological Association of Asia, consisting of 25 member associations and one affiliated member since its foundation in 1990, has planned to develop Asian guidelines for all urological fields. The field of stone diseases is the third of its guideline projects. Because of the different climates, and social, economic and ethnic environments, the clinical practice for urinary stone diseases widely varies among the Asian countries. The committee members of the Urological Association of Asia on the clinical guidelines for urinary stone disease carried out a surveillance study to better understand the diversity of the treatment strategy among different regions and subsequent systematic literature review through PubMed and MEDLINE database between 1966 and 2017. Levels of evidence and grades of recommendation for each management were decided according to the relevant strategy. Each clinical question and answer were thoroughly reviewed and discussed by all committee members and their colleagues, with suggestions from expert representatives of the American Urological Association and European Association of Urology. However, we focused on the pragmatic care of patients and our own evidence throughout Asia, which included recent surgical trends, such as miniaturized percutaneous nephrolithotomy and endoscopic combined intrarenal surgery. This guideline covers all fields of stone diseases, from etiology to recurrence prevention. Here, we present a short summary of the first version of the guideline - consisting 43 clinical questions - and overview its key practical issues.

Systemic analysis of urinary stones from the Northern, Eastern, Central, Southern and Southwest China by a multi-center study

BACKGROUND

To provide some basis for the prevention of urinary stones in general population, we did a systemic analysis of urinary stones from Northern, Eastern, Central, Southern and Southwest China by a multi-center study.

METHODS

A total of 11,157 urinary stones from Northern, Eastern, Central, Southern and Southwest China were obtained and analyzed by Fourier transform infrared spectroscopy. Combined with scanning electron microscopy and X-ray energy spectrometer, urinary stones were classified into different types. Furthermore, the correlation between stone types and clinical characteristics, as well as their regional distribution were elucidated.

RESULTS

Calcium oxalate stones were the most common type in each region, followed by calcium oxalate-calcium phosphate mixed stones, uric acid stones and calcium phosphate stones. The distribution of calcium oxalate stones were highest prevalence in Southwest China (67.9%, P < 0.05), followed by Eastern and Northern China. Anhydrous uric acid stones, with a constituent ratio of 19.3% in Southern China, and 13.7% in Central China, were significantly higher than that in other regions (P < 0.05). Elements analysis indicated varieties among stone types as well as distribution regions. Moreover, the clinical characteristics were highly correlated with stone types and anatomical locations but not their distribution regions.

CONCLUSIONS

The material and elements composition of urinary stones among different regions showed some varieties. Calcium oxalate stone has the highest constituent ratio in Southwest China, while anhydrous uric acid stone has the highest constituent ratio in Southern China. Moreover, the clinical characteristics were highly correlated with stone types and anatomical locations but not their distribution regions.

Significant association between RGS14 rs12654812 and nephrolithiasis risk among Guangxi population in China

BACKGROUND

Nephrolithiasis is a worldwide health problem that affects almost all populations. This study aimed to evaluate the association between rs12654812 of regulator of G protein signaling 14 (RGS14) gene and nephrolithiasis in the Chinese population.

METHODS

A total of 1541 participators including 830 cases and 711 controls were included from Guangxi area in China. Age, sex, BMI, smoking status, drinking status, creatinine, uric acid, and urea nitrogen were analyzed between the case group and control group.

RESULTS

We found that the G/A+A/A genotypes of rs12654812 had a significantly increased nephrolithiasis risk after adjusting age, sex, BMI, smoking, drinking, and hypertension, compared with G/G genotype (OR = 1.361, 95% CI = 1.033-1.794, P = .029). This hazardous effect was more pronounced in subgroup of age < 50, ever smoking, ever drinking, creatinine normal, and high uric acid. The G/A genotype of rs12654812 also had a significantly increased nephrolithiasis risk compared with G/G genotype. The A allele of rs12654812 significantly increased the risk of nephrolithiasis compared with the G allele after adjusting for age, sex, BMI, smoking, drinking and hypertension (OR = 1.277, 95% CI = 1.013-1.609, P = .038).

CONCLUSIONS

Our results suggest that the RGS14 polymorphism is involved in the etiology of nephrolithiasis and thus may be a genetic marker for nephrolithiasis.

Burden of Urolithiasis: Trends in Prevalence, Treatments, and Costs

CONTEXT

The recent evolution of management options for urolithiasis has presented a unique dilemma for the modern urologist. A comprehensive understanding of epidemiological trends along with current provider preferences in treating urinary stones would be beneficial.

OBJECTIVE

To review trends in the prevalence, treatments, and costs of urolithiasis worldwide.

EVIDENCE ACQUISITION

A literature review was performed using the MEDLINE database, the Cochrane Library Central search facility, Web of Science, and Google Scholar between 1986 and 2016. Keywords used for the search were "urolithiasis" and "prevalence; treatment; and cost".

EVIDENCE SYNTHESIS

The incidence and prevalence of urinary stones are rising around the world, including regions that have historically had low rates of urolithiasis. Common theories explaining this trend involve climate warming, dietary changes, and obesity. Shockwave lithotripsy (SWL) has been the preferred mode of treatment since its introduction in the 1980s. However, ureteroscopy (URS) has become increasingly popular for small stones regardless of location because of lower recurrence rates and costs. Developing countries have been slower to adopt URS technology and continue to use percutaneous nephrolithotomy at a steady rate.

CONCLUSIONS

URS has recently challenged SWL as the treatment modality preferred for small upper urinary tract stones. In some cases it is less expensive but still highly effective. As the burden of stone disease increases worldwide, appropriate selection of stone removal therapies will continue to play an important role and will thus require further investigation.

PATIENT SUMMARY

Urinary stones are becoming more prevalent. Recent advances in technology have improved the management of this disease and have decreased costs.

The systematic classification of urinary stones combine-using FTIR and SEM-EDAX

BACKGROUND

To explore underlying mechanism of urinary stones formation, the composition and microstructure of urinary stones were analyzed systematically with a large sample study from China.

MATERIALS AND METHODS

A total of 2437 urinary stones were obtained from the urology department at our Hospital. The composition of the stones was analyzed by Fourier transform infrared spectroscopy (FTIR). Meanwhile, the microstructure and element distribution were observed with scanning electron microscopy combined with element distribution analysis (SEM-EDAX).

RESULTS

Urinary stones were classified into eight types, that were consisted of calcium oxalate stones (1301/2437, 53.39%), calcium phosphate stones (131/2437, 5.38%), anhydrous uric acid stones (434/2437, 17.81%), magnesium ammonium phosphate stones (12/2437, 0.49%), sodium urate stones (5/2437, 0.21%), brushite stones (4/2437, 0.16%), cystine stones (3/2437, 0.12%) and mixed stones (547/2437, 22.45%, ten subtypes were included). Under SEM, they displayed distinct microstructures: plank-like, brick-like, polyhedron or paliform crystals for calcium oxalate stones, similar sized echin-sphere or rough bulbiform or tree bark-like crystals for calcium phosphate stones, rotten-wood-like or petrous crystals for anhydrous uric acid stones, globular or gallet-like crystals for magnesium ammonium phosphate stones, sawdust-like crystals for sodium urate stones, broken-wood-like crystals for brushite stones, stacking hexagonal cystine crystals for cystine stones, and two or more of the above crystals for mixed stones. Meanwhile, they also presented distinct elemental composition and distribution by EDAX.

CONCLUSIONS

Urinary stones can be classified into eight types, and exhibit a diversity of microstructure and elemental compositions in China. The formation process of different types of urinary stones may be diverse.