Renal stone disease: Causes, evaluation and medical treatment

Heatwave and upper urinary tract stones morbidity: effect modification by heatwave definitions, disease subtypes, and vulnerable populations

As heatwave occurs with increased frequency and intensity, the disease burden for urolithiasis, a heat-specific disease, will increase. However, heatwave effect on urolithiasis subtypes morbidity and optimal heatwave definition for urolithiasis remain unclear. Distributed lagged linear models were used to assess the associations between 32 defined heatwave and upper urinary tract stones morbidity. Relative risk (RR) and attributable fraction (AF) of upper urinary tract stone morbidity associated with heatwave of different intensities (low, middle, and high) were pooled by meta-analysis. Optimal heatwave definition was selected based on the combined score of AF, RR, and quasi-Akaike Information Criterion (QAIC) value. Stratified analyses were conducted to investigate the modification effects of gender, age, and disease subtypes. Association between heatwave and upper urinary tract stones morbidity was mainly for ureteral calculus, and AF was highest for low-intensity heatwave. This study's optimal heatwave was defined as average temperature > 93rd percentile for ≥ 2 consecutive days, with AF of 7.40% (95% CI: 2.02%, 11.27%). Heatwave was associated with ureteral calculus morbidity in males and middle-aged adults. While heatwave effect was statistically insignificant in females and other age groups. Managers should develop appropriate definitions to address heatwave based on regional characteristics and focus on heatwave effects on urolithiasis.

Risk factors of urolithiasis: A hospital-based retrospective study

Aim

Urolithiasis is the most prevalent urinary tract disease, posing a global public health concern. The escalating prevalence and recurrence rates of urolithiasis are attributed to lifestyle modifications, such as reduced physical activity and dietary habits. This retrospective study aims to explore the risk factors associated with urolithiasis among individuals diagnosed with this condition.

Method

A retrospective hospital-based study involving 60 participants meeting the inclusion criteria was conducted. The participants were selected through convenience sampling from the urology, nephrology, and medical wards at Saveetha Medical College and Hospital. Demographic variables were collected, and the risk factors were assessed using a checklist on one-to-one interviews.

Results

The study unveiled that most participants (68%) were male. Eighty percent of participants had the risk factor of decreased water intake, 74% consumed excess tomatoes, 56% had a history of recurrent urinary tract infections, 64% consumed an excessive amount of salt daily, 72% experienced a decreased urine output, 53% had a habit of alcohol consumption, and 45% included milk and milk products in their daily diet. A small percentage (5%) had a family history of urolithiasis. Additionally, 6% were undergoing Siddha treatment.

Conclusion

The findings from this study underscore the significant factors contributing to urolithiasis. They can inform public health campaigns to raise awareness about lifestyle modifications, dietary changes, and hydration protocols contributing to kidney stone formation.

High ambient temperature impact on the pattern of emergency-room visits due to renal colic in the Middle East

Urolithiasis has a seasonal pattern, with an established increase in incidence during the summer months. This study aims to assess the impact of high ambient temperatures on emergency room (ER) visits related to renal colic (RC) in a Middle Eastern country over the past decade. Population data were extracted using the MDClone Big Data platform. We recorded demographic and clinical data on all RC-associated ER visits from January 2012 to April 2023 and calculated the heat index (HI) that combines daily average coastal plane temperatures and humidity percentages. There was a total of 12,770 ER visits (median age 48 years, 9,236 (72%) males). The number of visits increased during the hottest months (July-October), with the highest numbers recorded during August. The number of visits remained stable throughout the study. We identified a linear association between humidity and the incidence of ER visits (p = 0.002), and a non-linear association between ambient temperature (p < 0.0001) and HI (p < 0.0001). There was a direct relationship between high temperatures and ER visits on the same day (risk ratio [RR]: 1.75, p = 0.036), with a 2-day lag (RR: 1.123, p = 0.024). In Conclusion, there is a significant relationship between temperature, humidity, HI, and the number of ER visits due to RC. Adjusted resource allocation and healthcare workforce availability are essential for managing additional cases during heat waves. Clinical implications: Increased demand is expected during heatwaves and within a 2-day lag, emphasizing the importance of proactive strategies to effectively manage RC patients.

Comparison of the Effect of Hydroalcholic Extract of Alhagi maurorum and Hydrochlorothiazide on Excretion of 4-10 mm Kidney and Ureteral Stones in Adults: A Randomized Prospective Study

Objective

The prevalence of kidney stones and their complications is high. The review of the literature showed the therapeutic effects of Alhagi maurorum extract on urinary tract stones. This study reviewed the Alhagi plant's hydroalcholic extract's effect on eliminating kidney and ureteral stones compared to hydrochlorothiazide.

Materials and Methods

In this randomized prospective study, from March 2019 to September 2021, 80 patients over 18 years of age with kidney stones in the upper ureter with a size of 4-10 mm were divided into two groups based on the block random allocation method. The first group received hydrochlorothiazide tablets (50 mg), and the second group received 1 gram/day of the hydroalcholic areal extract of Alhagi maurorum in a two-divided capsule. The mean size and number of stones, renal function tests, and side effects were checked and compared in both groups before and after the study.

Results

Mean age, sex, serum urea level (P=0.351), serum creatinine (P=0.393), stone size (P=0178), and the number of stones (P=0.052) before intervention were similar. After intervention, the size and number of stones diminished, up to 70% in both groups. However, there was not a statistically significant difference between the two groups.

Conclusion

The study showed that Alhagi maurorum is as effective as hydrochlorothiazide in treatment of kidney and ureteral stones with no significant complications and is promising.

Lime juice as a dietary alternative to mist potassium citrate for urine alkalinisation: A prospective, cross-over clinical trial

INTRODUCTION

Urinary citrate is a potent inhibitor of urinary crystallization that is freely filtered in the proximal tubule of the kidney. We aimed to investigate the effect of citrate supplementation with fresh lime juice on the urinary pH and calcium excretion level among healthy individuals compared with that of mist potassium citrate.

METHOD

In this prospective, cross-over single-centre study, 50 healthy medical student volunteers were randomly allocated to two treatment arms. One arm was prescribed with potassium citrate, while the other arm received citrate supplementation with a home preparation of fresh lime juice. The urinary pH and calcium-to-creatinine ratio (uCa/uCr) were measured at baseline and after 7 days of treatment. This was followed by a washout period of 2 weeks, after which each participant crossed over to the other treatment arm, and the urinary measurements were repeated.

RESULTS

Potassium citrate significantly increased the urinary pH among all participants, while fresh lime juice did not. Both fresh lime juice and potassium citrate reduced the uCa/uCr, although this effect was not significant.

CONCLUSION

Fresh lime juice is not as effective as potassium citrate in improving the urinary pH and calcium excretion level of healthy individuals. Therefore, it should be used as an adjunct rather than an alternative to potassium citrate.

Synthesize and characterization of CaOx crystals against various citrus waste peel extracts: an in vitro study

Citrus fruits have been consumed by world's population for several centuries. Since it's an edible source possesses various uses in treating many diseases. Among various diseases urolithiasis is one of the major issues globally demands in painless surgical treatment. Calcium Oxalate (CaOx) is found to be the most prevailing constituent of renal calculus in humans which tends to be the categories of the urolithiasis. Citric acid is commonly used in treating to dissolve them in medications. Citrate compound has the ability to bind with calcium stones to relieve oxalates in urine. The objective of the present study is to assess the efficacy of citrate compounds from waste citrate peels describing the inhibition of calcium oxalate (CaOx) crystals. Multistep extraction procedures were performed for the selected citrus peels of Citrus limon, Citrus limetta and Citrus sinensis using different solvents (hexane, aqueous and ethanol) and were tested for its inhibitory actions with different parameters against the synthesized CaOx crystals. The synthetic CaOx crystals were characterized by Microscopy, FTIR, SEM, XRD, and TGA. The structural change in the crystal was observed for inhibition at various stages like nucleation, growth and aggregation when treated with the ethanol extracts of citrus peels. Thus the present investigation concludes that the ethanol extracts of C. sinensis peels highly inhibits at a concentration of 1000 (µg/mL) in 60 min when compared to other solvents. This research would give additional information in preparation of drugs against CaOx urolithiasis in future pharmaceutical development processes.

Major and Trace Elements in Human Kidney Stones: A Preliminary Investigation in Beijing, China

Kidney stone disease affects people globally, with its prevalence on the rise. Given the importance of elements’ function in formation of kidney stones, this study investigated major and trace element content in thirty kidney stone samples from patients in Beijing. The kidney stone samples included inorganic components (calcium oxalate and carbonate apatite) and organic components (uric acid). Results showed that Ca is much higher in inorganic components than organic components. Compared to inorganic components, uric acid has a very low content of elements except for Cu and Se, which may be derived from the liver. Carbonate apatite stones have a higher element content (such as Na, K, Sr, Zn, Rb, Ba, Li, and Ti) than calcium oxalate stones, especially enrichment of Mg. The principal components analysis (PCA) extracted three principal components (PCs) with total variances of 91.91%, including the PC1 (45.08%): Na-Li-Ti-Ba-Sr-Zn, PC2 (30.05%): Rb, K, Mg, and PC3 (16.78%): Cu-Se, indicating that there are co-precipitated processes of these elements by their specific properties. A different distribution of stone types in the three components indicates a significant discrepancy in their element content, which can be an essential reference for patient intake elements.

Preliminary Data on Geochemical Characteristics of Major and Trace Elements in Typical Biominerals: From the Perspective of Human Kidney Stones

The chemical composition of biominerals is essential for understanding biomineral formation and is regarded as an attractive subject in bio-mineralogical research on human kidney stones (urinary calculi). In order to obtain more geochemically interpreted data on biogenic minerals, mineralogical compositions and major and trace element concentrations of sixty-six kidney stone samples derived from kidney stone removal surgeries were measured. Infrared spectroscopy results showed that calcium oxalate monohydrate (COM) and calcium oxalate dihydrate (COD) were the two main mineral components of kidney stones. Geochemical results indicated that major and trace element concentrations were present in the following order: Ca > Mg > Na > K > Zn > Fe > Pb > Ba > Cu > Ti > Mo > Cd > Cr. With the exception of Ca, Mg was the second-most abundant element. Zn exhibited higher concentrations relative to other trace elements, which suggests a potential substitution of calcium by metal ions with a similar charge and radius rather than by metals in kidney stone formation. Pb appeared in significantly higher concentrations than in previous studies, which indicates Pb enrichment in the environment. In order to discern multi-element relationships within kidney stones, principal component analysis was applied. Three principal components (PCs, eigenvalues >1) were extracted to explain 64.4% of the total variance. The first component exhibited positively correlated Na-Zn-Cr-Mo-Cd-Pb, while the second component exhibited more positively weighted Mg-K-Ba-Ti. Fe-Cu demonstrated a positive correlation in the third component. This study suggests that Ca exhibits a preference for uptake by oxalates during human urinary stone crystallization, while other alkali metals and alkaline earth metals precipitate with phosphate.

Biomarkers of iron status in allopurinol-treated renal stone patients

Limited evidence exists on the effect of xanthine oxidase inhibitors in nephrolithiasis patients on iron status markers, beyond their effects on urate. The aim of this study was to investigate whether allopurinol therapy was associated with a significant impact on parameters related to iron status, in patients with renal stones. Allopurinol treatment was associated with a nonsignificant decline in serum uric acid. There were no significant differences in serum levels of transferrin and ferritin after treatment with allopurinol compared to pre-treatment levels. A non-significant fall in serum levels of haptoglobin was registered. The drug was associated with a significant rise in serum iron levels. Serum uric acid and iron did not show a significant correlation with any parameter in the study. Allopurinol exerted an overall non-significant effect on iron metabolism in nephrolithiasis patients, save for serum iron, this entails lack of untoward effects in populations with-iron related conditions.

The Synergistic Effect of Three Essential Oils against Bacteria Responsible for the Development of Lithiasis Infection: An Optimization by the Mixture Design

The present study aimed to determine the chemical composition and the synergistic effect of three plants' essential oils (EOs), Eucalyptus camaldulensis (ECEO), Mentha pulegium (MPEO), and Rosmarinus officinalis (ROEO), against three bacterial strains, Proteus mirabilis, Klebsiella pneumoniae, and Staphylococcus aureus, in order to increase the antimicrobial effectiveness by the use of a low dose of essential oils, consequently decreasing the toxicity and negative impact. For this reason, an augmented simplex-centroid mixture design was used to build polynomial models in order to highlight the synergy between the essential oils against bacterial strains. Antimicrobial effect screening was performed by the disc diffusion method and the minimal inhibitory concentrations (MIC) were also studied. The gas chromatography/mass spectrometry (GC-MS) results show the richness of these essential oils by terpenic compounds, especially 1,8-Cineole and P-Cymene for ECEO, Pulegone for MPEO, and α-Pinene and Camphene for ROEO. Moreover, a significant antibacterial effect has been demonstrated and the best values were revealed by MPEO and ECEO against P. mirabilis and K. pneumoniae, with inhibition zones (IZ) of 25 and 20 mm, respectively, and an MIC of 0.0391% (v:v) against K. pneumoniae. The optimal mixtures showed a synergistic effect of essential oils, and the lowest minimal inhibitory concentrations of the mixtures (MICm) were in the order of 29.38% of MPEO, 45.37% of ECEO, and 25.25% of ROEO against P. mirabilis and in the order of 60.61% of MPEO and 39.39% of ROEO against K. pneumoniae. These results indicate the antibacterial efficacy of the three essential oils combined and suggest their importance in the treatment of urinary tract infections caused by resistant bacterial strains.

Analysis of 114 Pedigrees of Renal Stone Patients: A Retrospective Review

BACKGROUND

 Renal and ureteric stones (RS) can form due to genetic, metabolic, environmental, and diet-hydration related factors. Studies have shown that patients with family history (FH) of RS have higher likelihood of recurrence.

MATERIALS AND METHODS

 We conducted a retrospective cross-sectional study on 114 pedigrees to investigate the impact of FH on recurrence of RS and examine patterns of inheritance.  Results: Family history of renal stone disease was found in 42% of all patients. There was a significant increase of stone recurrence in RS patients with a positive FH (p=0.001). Seventy-one percent of patients with recurrent stones had at least one family member with RS. Interestingly, male penetrance was higher in RS recurrence, where a greater proportion of males had no FH of RS, indicating that there may be other factors involved as well.  Conclusion: Family history in RS patients should be continuously explored for the possible underlying genetic influence, whilst keeping in mind the dietary habits of the family.

[Interpretation of the metabolic study in renal lithiasis and its treatment]

Urolithiasis is a common disease, and is an important health problem that is associated with a great economic burden. The nature of stone disease varies according by dietary and lifestyle factors, including, among others, climate variations. The majority of patients will suffer a new lithiasic episode at some point in their life, unless preventive measures, such as changing lifestyles and dietary habits, are put in place to avoid it. The risk factors involved in lithogenesis should be evaluated in order to reduce recurrences. In the majority of these patients, metabolic changes are observed in the urine that predispose lithogenesis. The kind of evaluation depends on stone composition and on the clinical presentation. A diagnosis of systemic and renal diseases of lithogenic nature can be diagnosed with these studies, and they also enable the adoption of precise prophylactic measures that achieve control of recurrence in a great number of patients.

The association of Dietary Approaches to Stop Hypertension-style diet with urinary risk factors of kidney stones formation in men with nephrolithiasis

OBJECTIVE

The relation of the Dietary Approaches to Stop Hypertension (DASH)-style diet to urinary lithogenic factors is unclear. This study aimed to assess the association between adherence to the DASH diet and urinary risk factors of kidney stones formation.

METHODS

A total of 264 men apparently with nephrolithiasis, aged 18-89 years, participated in this cross-sectional study. The food item-based DASH diet based on 8 components (nuts and legumes, red and processed meat, low-fat dairy products, sweetened beverages, fruits, vegetables, sodium, and whole grains) and nutrient-based DASH score based on 9 target nutrients (protein, fiber, total fat, saturated fat, cholesterol, sodium, calcium, potassium, and magnesium) were calculated using a food frequency questionnaire. Urine analysis was performed to measure hypercalciuria, hypocitraturia, hyperoxaluria, hyperuricosuria, and hypercreatinuria as study outcomes. Multivariate logistic regression analysis was used to evaluate the relation of DASH diet to urinary factors.

RESULTS

After multivariate adjustment, high adherence to the food-based or nutrient-based DASH dietary patterns was significantly associated with lower odds for hypercreatininuria, hypocitraturia, and hypercalciuria. Higher nutrient-based DASH diet scores were related to lower odds of hyperuricosuria and moderate adherence to the food-based DASH score increased odds for hyperoxaluria. Moreover, expect for "Nuts and legumes" and sodium, other components of DASH diet were significantly related to urinary lithogenic factors.

CONCLUSION

Adherence to the DASH diet may be a strong preventive approach to decrease urinary risk factors of kidney stone formation.

Identification of Novel Human Serum Albumin (SA) Inhibitors from Scoparia Dulsis for Urolithiasis

Background::

Urolithiasis is the process of forming stones in the kidney, bladder, and/or urinary tract. It has been reported that kidney stones are the third most common disorder among urinary diseases. At present, surgical procedures and Extracorporeal Shock Wave Lithotripsy (ESWL) are commonly employed for the treatment of Urolithiasis. The major drawback of these procedures is the recurrence of stones.

Methods:

This study aimed to identify potential natural inhibitors against human Serum Albumin (SA) from the plant Scoparia Dulsis for Urolithiasis. As protein-ligand interactions play a key role in structure- based drug design, this study screened 26 compounds from Scoparia Dulsis and investigated their binding affinity against SA by using molecular docking. The three dimensional (3D) structure of SA was retrieved from Protein Data Bank (PDB) and docked with PubChem structures of 26 compounds using PyRX docking tool through Autodock Vina. Moreover, a 3D similarity search on the PubChem database was performed to find the analogs of best scored compound and docking studies were performed. Drug-likeness studies were made using Swiss ADME and Lipinski’s rule of five was performed for the compounds to evaluate their anti-urolithiatic activity.

Results:

The results showed that citrusin c (Eugenyl beta-D-glucopyranoside) exhibited best binding energy of -8.1 kcal/mol with SA followed by aphidicolin, apigenin, luteolin and scutellarein. Two compounds (PubChem CID 46186820, PubChem CID 21579141) analogous to citrusin c were selected based on the lowest binding energy.

Conclusion:

This study, therefore, reveals that these compounds could be promising candidates for further evaluation for Urolithiasis prevention or management.

Seasonal Variation in the Frequency of Presentation with Acute Ureteral Colic and Its Association with Meteorologic Factors

Introduction: A seasonal variation in the frequency of acute stone presentations has been observed in studies from the United States, Africa, and Asia. The increased incidence of acute stone presentations during periods of warm weather has been attributed to both the dehydrating effect of elevated temperatures and the vitamin D related increase in calciuria during periods of increased sunshine. The aim of this study is to establish whether the association between various meteorologic parameters and the frequency of acute stone presentations also exists in a European climate. Methods: All computed tomography kidneys, ureters and bladder scans performed by Emergency Departments within the Dublin Midland Hospital Group between June 2017 and September 2018 were identified from the national radiologic database. The date of scan in addition to stone parameters (site, size, and side) was recorded. These data were then correlated with weather recordings obtained from the Irish meteorologic office. Results: A total of 2441 patients were investigated for suspected renal colic during the study period of which 781 were confirmed to have ureteral stones. An increased frequency of acute stone presentations was observed during the summer months of both years (June, July, and August). Unexpectedly, the heat wave of summer 2018 was not associated with an increased frequency of nephrolithiasis compared with summer 2017. Conclusion: There is an increased frequency of acute nephrolithiasis during the summer months in Ireland. Health care services should be tailored to expect an increase in service needs during these periods of increased activity.

A Short Review on the Relationships Between Nephrolithiasis and Myocardial Infarction

The interaction between organs is a crucial part of modern medicine. As a very prerequisite to manage a disease, practitioners should have a full awareness of the related organs. Kidney and heart are two vital organs that are closely interconnected in various fields. These two organs have a lot of common risk factors for making a person unhealthy; therefore, if you prevent the disease in one of them, the other's morbidity might be alleviated as well. Among them, nephrolithiasis and myocardial infarction (MI) have more risk factors in common, and both could be fatal. Also, these two diseases are important regarding the prevalence, incidence, and burden of disease. Some studies confirm the relationship between MI and nephrolithiasis; however, further researches are needed to discover the exact direction of their relationship. The present review aims to explain the mechanism of MI and nephrolithiasis; clarify the relationship between these two disease based on physiological, pathological, and clinical studies; and propose some solutions for the prevention and treatment of such diseases.

Metabolism of Oxalate in Humans: A Potential Role Kynurenine Aminotransferase/Glutamine Transaminase/Cysteine Conjugate Beta-lyase Plays in Hyperoxaluria

Hyperoxaluria, excessive urinary oxalate excretion, is a significant health problem worldwide. Disrupted oxalate metabolism has been implicated in hyperoxaluria and accordingly, an enzymatic disturbance in oxalate biosynthesis can result in the primary hyperoxaluria. Alanine glyoxylate aminotransferase-1 and glyoxylate reductase, the enzymes involving glyoxylate (precursor for oxalate) metabolism, have been related to primary hyperoxalurias. Some studies suggest that other enzymes such as glycolate oxidase and alanine glyoxylate aminotransferase-2 might be associated with primary hyperoxaluria as well, but evidence of a definitive link is not strong between the clinical cases and gene mutations. There are still some idiopathic hyperoxalurias, which require a further study for the etiologies. Some aminotransferases, particularly kynurenine aminotransferases, can convert glyoxylate to glycine. Based on biochemical and structural characteristics, expression level, subcellular localization of some aminotransferases, a number of them appear able to catalyze the transamination of glyoxylate to glycine more efficiently than alanine glyoxylate aminotransferase-1. The aim of this minireview is to explore other undermining causes of primary hyperoxaluria and stimulate research toward achieving a comprehensive understanding of underlying mechanisms leading to the disease. Herein, we reviewed all aminotransferases in the liver for their functions in glyoxylate metabolism. Particularly, kynurenine aminotransferase-I and III were carefully discussed regarding their biochemical and structural characteristics, cellular localization, and enzyme inhibition. Kynurenine aminotransferase-III is, so far, the most efficient putative mitochondrial enzyme to transaminate glyoxylate to glycine in mammalian livers, might be an interesting enzyme to look over in hyperoxaluria etiology of primary hyperoxaluria and should be carefully investigated for its involvement in oxalate metabolism.

Kidney Stone Disease: An Update on Current Concepts

Kidney stone disease is a crystal concretion formed usually within the kidneys. It is an increasing urological disorder of human health, affecting about 12% of the world population. It has been associated with an increased risk of end-stage renal failure. The etiology of kidney stone is multifactorial. The most common type of kidney stone is calcium oxalate formed at Randall's plaque on the renal papillary surfaces. The mechanism of stone formation is a complex process which results from several physicochemical events including supersaturation, nucleation, growth, aggregation, and retention of urinary stone constituents within tubular cells. These steps are modulated by an imbalance between factors that promote or inhibit urinary crystallization. It is also noted that cellular injury promotes retention of particles on renal papillary surfaces. The exposure of renal epithelial cells to oxalate causes a signaling cascade which leads to apoptosis by p38 mitogen-activated protein kinase pathways. Currently, there is no satisfactory drug to cure and/or prevent kidney stone recurrences. Thus, further understanding of the pathophysiology of kidney stone formation is a research area to manage urolithiasis using new drugs. Therefore, this review has intended to provide a compiled up-to-date information on kidney stone etiology, pathogenesis, and prevention approaches.

Effect of Crystal Shape and Aggregation of Calcium Oxalate Monohydrate on Cellular Toxicity in Renal Epithelial Cells

Renal epithelial cell injury is a key step in inducing kidney stone formation. This injury induced by crystallites with different shapes and aggregation states has been receiving minimal research attention. To compare the shape and aggregation effects of calcium oxalate crystals on their toxicity, we prepared calcium oxalate monohydrate (COM) crystals with the morphology of a hexagonal lozenge, a thin hexagonal lozenge, and their corresponding aggregates. We then compared their toxicities toward human kidney proximal tubular epithelial (HK-2) cells. All four shapes of COM crystals caused cell-membrane rupture, upregulated intracellular reactive oxygen, and decreased mitochondrial membrane potential. This series of phenomena ultimately led to necrotic cell death. The overall damage in cells was determined in terms of both exterior and interior damage. Crystals with a large Ca2+ ion-rich (1̅01) active face showed the greatest toxicity in HK-2 cells and the largest extent of adhesion onto the cell surface. Crystals with sharp edges easily caused cell-membrane ruptures. The aggregation of sharp crystals aggravated cell injury, whereas the aggregation of blunt crystals weakened cell injury. Therefore, crystal shapes and aggregation states were important factors that affected crystal toxicity in renal epithelial cells. All of these findings elucidated the relationship between the physical properties of crystals and cytotoxicity and provided theoretical references for inhibiting stone formation.

Short-Term Changes in Algometry, Inclinometry, Stabilometry, and Urinary pH Analysis After a Thoracolumbar Junction Manipulation in Patients with Kidney Stones

OBJECTIVES

To determine the efficacy of a high-velocity low-amplitude manipulation of the thoracolumbar junction in different urologic and musculoskeletal parameters in subjects suffering from renal lithiasis.

DESIGN

Randomized, controlled blinded clinical study.

SETTINGS/LOCATION

The Nephrology departments of two hospitals and one private consultancy of physiotherapy in Valencia (Spain).

SUBJECTS

Forty-six patients suffering from renal lithiasis.

INTERVENTIONS

The experimental group (EG, n = 23) received a spinal manipulation of the thoracolumbar junction, and the control group (CG, n = 23) received a sham procedure.

OUTCOME MEASURES

Pressure pain thresholds (PPTs) of both quadratus lumborum and spinous processes from T10 to L1, lumbar flexion range of motion, stabilometry, and urinary pH were measured before and immediately after the intervention. A comparison between pre- and postintervention phases was performed and an analysis of variance for repeated measures using time (pre- and postintervention) as intrasubject variable and group (CG or EG) as intersubject variable.

RESULTS

Intragroup comparison showed a significant improvement for the EG in the lumbar flexion range of motion (p < 0.001) and in all the PPT (p < 0.001 in all cases). Between-group comparison showed significant changes in PPT in quadratus lumborum (p < 0.001), as well as in the spinous processes of all of the evaluated levels (p < 0.05). No changes in urinary pH were observed (p = 0.419).

CONCLUSION

Spinal manipulation of the thoracolumbar junction seems to be effective in short term to improve pain sensitivity, as well as to increase the lumbar spine flexion.

In vitro evidence of the promoting effect of testosterone in kidney stone disease: A proteomics approach and functional validation

Incidence of kidney stone disease in males is 2- to 4-fold greater than in females. This study aimed to determine effects of testosterone on kidney stone disease using a proteomics approach. MDCK renal tubular cells were treated with or without 20nM testosterone for 7days. Cellular proteins were extracted, resolved by 2-DE, and stained with Deep Purple fluorescence dye (n=5 gels derived from 5 independent samples/group). Spot matching, quantitative intensity analysis, and statistics revealed significant changes in levels of nine protein spots after testosterone treatment. These proteins were then identified by nanoLC-ESI-Qq-TOF MS/MS. Global protein network analysis using STRING software revealed α-enolase as the central node of protein-protein interactions. The increased level of α-enolase was then confirmed by Western blotting analysis, whereas immunofluorescence study revealed the increased α-enolase on cell surface and intracellularly. Functional analysis confirmed the potential role of the increased α-enolase in enhanced calcium oxalate monohydrate (COM) crystal-cell adhesion induced by testosterone. Finally, neutralization of surface α-enolase using anti-α-enolase antibody successfully reduced the enhanced COM crystal-cell adhesion to the basal level. Our data provided in vitro evidence of promoting effect of testosterone on kidney stone disease via enhanced COM crystal-cell adhesion by the increased surface α-enolase.

BIOLOGICAL SIGNIFICANCE

The incidence of kidney stone disease in male is 2- to 4-fold greater than in female. One of the possible factors of the male preference is the higher testosterone hormone level. However, precise molecular mechanisms that testosterone plays in kidney stone disease remained unclear. Our present study is the first exploratory investigation on such aspect using a proteomics approach. Our data also provide a novel mechanistic aspect of how testosterone can impact the risk of kidney stone formation (i.e. the discovery that testosterone increases alpha-enolase expression on the surface of renal tubular cells that is responsible, at least in part, for crystal-cell adhesion).

Renal tubular injury induced by ischemia promotes the formation of calcium oxalate crystals in rats with hyperoxaluria

Hyperoxaluria and cell injury are key factors in urolithiasis. Oxalate metabolism may be altered by renal dysfunction and therefore, impact the deposition of calcium oxalate (CaOx) crystals. We investigated the relationship of renal function, oxalate metabolism and CaOx crystal deposition in renal ischemia. One hundred male Sprague-Dawley rats were randomly divided into four groups. Hyperoxaluria model (Group A and B) was established by feeding rats with 0.75 % ethylene glycol (EG). The left renal pedicle was clamped for 30 min to establish renal ischemia Groups (B and C), while Groups A and D underwent sham operation. Then, serum and urine oxalate (Ox), creatinine (Cr) and urea nitrogen (UN) levels were evaluated by liquid chromatography mass spectrometry (LCMS) and ion mass spectrum (IMS) at days 0, 2, 4, 7, and 14. CaOx crystallization was assessed by transmission electron microscope (TEM). A temporal and significant increase of serum Cr and UN levels was observed in Groups B and C compared to values obtained for Groups A and D (P < 0.05). Ox levels in serum and urine were significantly higher in Groups A and B than in the other two groups from day 7 (P < 0.05). In addition, CaOx crystallization was observed in both Groups A and B, but Group B showed earlier and more pronounced crystal deposition in the renal tissue. Our results indicated that renal tubular injury induced by renal ischemia might not affect Ox levels but could promote CaOx crystal retention under hyperoxaluria.

Randomized and double-blinded clinical trial of the safety and calcium kidney stone dissolving efficacy of Lapis judaicus

ETHNOPHARMACOLOGICAL RELEVANCE

Kidney stones are one of the most common disorders of the urinary tract and cause a great deal of morbidity and economic loss. Because of the side effects and costs of current interventional procedures, researchers are interested in finding medicinal therapies. In this regard, some reports have focused on traditional medicines as a drug discovery resource. Iranian scholars in the medieval era recommended Lapis judaicus for the prevention and treatment of kidney stones. The present study assessed the efficacy and safety of Lapis judaicus on the size of calcium kidney stones and some related biochemical factors in blood and urine.

MATERIALS AND METHODS

Sixty patients with kidney stone disease were included in this double-blind randomized clinical study. Thirty patients received 2g of Lapis judaicus powder in hard capsules per day for 10 weeks, and another 30 patients received a placebo for the same period. Ultrasonography was performed on patients, and blood and urine samples were collected before and after the study to evaluate the efficacy and safety of Lapis judaicus in calcium kidney stone patients.

RESULTS

The size of the kidney stones was reduced significantly (p<0.001) in the drug group. In 9 patients from the drug group, the stone was completely dissolved. Moreover, urine calcium concentration and specific gravity were reduced and urine magnesium was increased (p<0.05). Lapis judaicus did not affect BUN, creatinine, ALT, or AST.

CONCLUSION

Contrary to the placebo group, the size of kidney stones was reduced significantly in the treatment group after oral administration of Lapis judaicus. This preliminary study confirms traditional knowledge of the efficacy and safety of Lapis judaicus in kidney stone diseases and suggests a new method to treat calcium kidney stones. Further detailed in vitro and in vivo studies aimed at discovering the mechanism of action of Lapis judaicus and clinical studies involving a larger population of patients will be necessary to fully explain and confirm the results obtained in the present study.

Adequate dietary intake and nutritional status in patients with nephrolithiasis: new targets and objectives

OBJECTIVES

Modifiable risk factors for kidney stones, such as diet and nutritional status, are targets in the treatment and prevention of nephrolithiasis. The aim of the present study was to assess the nutritional state and energy and nutrient adequacy of patients with nephrolithiasis via anthropometric evaluation, dietary inquiry, and urine biochemistry.

DESIGN

The present observational cross-sectional study.

SETTING

An outpatient, nephrolithiasis clinic of a tertiary care, university hospital.

SUBJECTS

A total of 31 patients with nephrolithiasis and 25 controls were assessed.

INTERVENTIONS

All patients were subjected to nutritional evaluation, including dietary inquiry and chemical tests of blood and 24-hour urine samples.

MAIN OUTCOME MEASURE

Nutritional state and nutrient ingestion adequacy.

RESULTS

The group of patients with nephrolithiasis exhibited high body mass index, abdominal circumference, and body fat percentage values. The protein, sodium, calcium, potassium, and oxalate intakes differed significantly from the recommended values in both the nephrolithiasis and control groups. The nephrolithiasis and control groups differed only in terms of oxalate intake (159 ± 119.27 vs. 112 ± 47.9, respectively, P = .042). Regarding urine biochemistry, 30% of the patients with nephrolithiasis exhibited hypercalciuria, versus 12% of the control group.

CONCLUSIONS

The prevalence of individuals with overweight/obesity was high in both the nephrolithiasis and control groups. This finding indicates that in addition to orientation regarding nonlithogenic dietary habits, continuous education by a multidisciplinary staff must also address the prevention and treatment of obesity.

The association between urinary tract infection and idiopathic hypercalciuria in children

BACKGROUND

Identifying the risk factors is important in prevention of urinary tract infections (UTIs) in children. The aim of this study is to evaluate the association of UTI and idiopathic hypercalciuria (IHC).

METHODS

Two hundred and twenty-four children aged between 1 month and 16 years and diagnosed to have UTI were evaluated for urinary calcium excretion. The children were diagnosed to have IHC if their urinary calcium/creatinine ratios in at least two different spot urine samples were >0.6 between 0-1 year old and ≥0.21 over 1 year or daily calcium excretion >4 mg/kg.

RESULTS

The frequency of IHC was found to be 16.7%. Family history of urolithiasis, parental consanguinity, presentation with abdominal pain, loss of appetite, and discomfort were found to be significantly higher in the IHC group. No association was found between IHC and the recurrence of UTI, presence of vesicoureteral reflux, renal scar formation, and the prognosis.

CONCLUSIONS

IHC should be considered among the risk factors for UTI and should be investigated particularly in patients with family history of urinary stones and suggestive complaints of IHC.

Medical management of renal stone

Kidney stone is a common clinical problem faced by clinicians. The prevalence of the disease is increasing worldwide. As the affected population is getting younger and recurrence rates are high, dietary modifications, lifestyle changes, and medical management are essential. Patients with recurrent stone disease need careful evaluation for underlying metabolic disorder. Medical management should be used judiciously in all patients with kidney stones, with appropriate individualization. This chapter focuses on medical management of kidney stones.

Nephrolithiasis: Endocrine evaluation

Nephrolithias is a common problem in populations around the world, and contribute significantly to the development of end stage renal disease. It is a matter of debate whether the metabolic factors responsible for renal stone formation are similar or variable in different populations around the globe. This review discusses the influence of different metabolic and dietary factor, and some other co-morbid conditions on the etiopathogenesis Nephrolithiasis. Evaluation and medical management of Nephrolithiasis is summarized in the later part of the article.

Medical evaluation and management of urolithiasis

Nephrolithiasis is a highly prevalent condition with a high recurrence rate that has a large impact on the quality of life of those affected. It also poses a great financial burden on society. There have been great advancements in the surgical treatment of stone disease over the past several decades. The evolution of surgical technique appears to have overshadowed the importance of prevention of stone disease despite evidence showing medical therapies significantly decreasing stone recurrence rates. Herein we review the metabolic evaluation of stone formers with the use of specific blood and urine tests. We complete our discussion with a review of the medical management of stone formers providing both general recommendations as well as reviewing focused therapies for specific metabolic abnormalities and medical conditions.

Chemical and morphological analysis of kidney stones: a double-blind comparative study

PURPOSE

To compare chemical to morphological kidney stone composition analysis based on a sample of 50 stones retrieved from patients at a nephrology service.

METHODS

The chemical analysis was performed with a Bioclin® kit, while a 10-mm magnifying glass (10x; Prolabo, Paris, France) was employed in the morphological analysis. Findings obtained with the two methods were compared and classified as concordant (100% agreement), partly concordant (concordant for major components, discordant for minor components) or discordant (discordant for major components).

RESULTS

In the chemical analysis, the most commonly observed major component was calcium (70%), followed by oxalate (66%), ammonium (56%), urate (28%) and carbonate (24%). In the morphological analysis, the most commonly observed major components were calcium phosphate and magnesium (32% each), followed by calcium oxalate monohydrate (24%), uric acid and urates (20% each), calcium oxalate dihydrate (18%) and cystine (6%). Infectious kidney stones were identified in 34% and 24% of cases by morphological and chemical analysis, respectively. Thirty-eight percent of the samples were classified as concordant, 52% were partly concordant and 10% were discordant.

CONCLUSION

We suggest kidney stones be routinely submitted to both types of analysis for a better understanding of the mechanisms involved in lithogenesis.

Chemical composition and microstructure of uroliths associated with the feeding of high-level cottonseed meal diet to sheep

The chemical composition and microstructure of five urolith samples (4 bladder stones and one kidney stone) associated with the feeding of high level of cottonseed meal (CSM) diet to Chinese merino fine wool sheep (Junken breed, Xinjiang) were examined by optical microscope, X-ray diffraction, X-ray energy dispersive spectrometry (EDS), scanning electron microscopy (SEM), and infrared spectroscopy analysis. The bladder stone samples appeared yellow or white, small powder and loose mass, and as finely granular under the optical microscope. However, the kidney stone samples from a experimental sheep were found as small brown mass, higher hardness, and as a cracklike structure. Oxygen, phosphorus, potassium and magnesium were found as four major elements in these uroliths by X-ray energy dispersive spectrometry (EDS). Potassium magnesium phosphate (MgKPO(4)) and potassium magnesium phosphate hexahydrate (MgKPO(4)·6H(2)O) were major components in the bladder stones, while less magnesium ammonium phosphate hexahydrate (MgNH(4)PO(4)·6H(2)O) examined by X-ray diffraction and infrared spectroscopy analysis. However, the newly found prismatic crystals, which were rich in magnesium and pyrophosphate, were identified as magnesium pyrophosphate (Mg(2)P(2)O(7)) in the kidney stone. The bladder stone samples appeared irregular mass and balls, cracked under SEM with low magnification, while appeared cracked, irregular layer-like, honeycomb-like or tiny balls under high magnification. The kidney stone samples were observed as cone, irregular block or layered crystal structures.

Nutcracker syndrome with urolithiasis

The nutcracker syndrome, caused by compression of the left renal vein between the superior mesenteric artery and the aorta, usually manifests with hematuria, flank pain and proteinuria. We report on a 9-year-old boy who was previously diagnosed with urolithiasis but had significant proteinuria, not explained by this diagnosis. On further investigation by renal Doppler ultrasonography it was found that he had nutcracker syndrome. We would like to emphasize that this syndrome should be considered where there is no obvious cause of proteinuria and hematuria.

Metabolic abnormalities in patients with nephrolithiasis: comparison of first-episode with recurrent cases in Southern Iran

BACKGROUND

Metabolic disorders are one of the etiologic factors in renal stone formation. The aim of present study was to evaluate prevalence of metabolic disorders in patients with renal stone.

METHODS

From 572 patients referring to our urologic clinics, 376 patients participated in the study. Patients were divided to first time stone former (group A) and recurrent renal stone (group B). Twenty-four hour urine specimens were obtained for urinary calcium, oxalate, magnesium, citrate, uric acid, phosphor and 24-h urine volume. Venous blood samples were obtained evaluating serum phosphate, uric acid, and calcium. The prevalence of each metabolic disorder was detected, and two groups were compared regarding metabolic disorders.

RESULTS

The prevalence of renal stone in male patients was 63.04% versus 36.96% in female patients (P < 0.05). The most common abnormality observed in patients was low 24-h urine volume (58.24%) followed by hypercalciuria (17.18%) and hyperuricosuria (15.15%). Hyperuricemia was found in 6 first time stone former patients and 14 patients with recurrent renal stone (P = 0.04). There was no statistically significant difference between group A and B in other metabolic abnormalities (P > 0.05).

CONCLUSION

Low 24-h urine volume was the most common abnormalities in patients with nephrolithiasis in our region. Metabolic evaluation must be performed in all patients with renal stone even those with first time stone formation.

Strain differences in urinary factors that promote calcium oxalate crystal formation in the kidneys of ethylene glycol-treated rats

Ethylene glycol (EG)-induced hyperoxaluria is the most commonly employed experimental regimen as an animal model of calcium oxalate (CaOx) stone formation. The variant sensitivity to CaOx among different rat strains has not been fully explored, although the Wistar rat is known to accumulate more CaOx in kidney tissue after low-dose EG exposure than in the Fischer 344 (F344) rats. Supersaturation of CaOx in tubular fluid contributes to the amount of CaOx crystal formation in the kidney. We hypothesized that the urinary supersaturation of CaOx in Wistar rats is higher than that of F344 rats, thereby allowing for greater CaOx crystal deposition in the Wistar rat. Age-matched male Wistar and F344 rats were treated with 0.75% EG or drinking water for 8 wk. Twenty-four-hour urine was collected at 0, 2, 4, 6, and 8 wk for analysis of key electrolytes to calculate the CaOx supersaturation. Plasma oxalate level was also measured. Our data confirmed the different sensitivity to renal toxicity from EG between the two rat strains (Wistar > F344). After EG treatment, the plasma oxalate level and urine oxalate excretion were markedly greater in the Wistar rats than in the F344 rats, while urine calcium was slightly decreased in Wistars. Thus, the CaOx supersaturation in urine of Wistar rats was higher, which led to a greater crystal deposition in kidney in Wistar rats. These studies suggest that during EG treatment, changes in urine electrolytes and in CaOx supersaturation occur to a greater extent in the Wistar rat, in agreement with its greater sensitivity to EG toxicity.

Risk factors for nephrolithiasis in children

OBJECTIVE

The aim of this study is to evaluate the clinical outcome in children with urinary calculi, to detect risk factors for nephrolithiasis in childhood.

MATERIAL AND METHODS

This retrospective study comprised 62 pediatric nephrolithiasis patients who have come for routine follow-up visits between the dates of January 2002-August 2006 (48% girls and 52% boys).

RESULTS

The mean age of the patients was 8.8 +/- 4.5 years (1-16 years). Hypercalciuria was found in 25 (40%) patients. The mean urinary calcium excretion for hypercalciuric patients was 5.7 +/- 1.2 mg/kg (4.8 mg/kg per day). In our hypercalciuric patients 15 (60%) children had abdominal or flank pain, seven (28%) patients macroscopic hematuria and three (12%) dysuria. Hypocitraturia is the second important risk factor for nephrolithiasis. Urinary calcium excretion showed a positive correlation with the stone size (r = 0.482, P = 0.043). A positive correlation was found between recurrent urinary tract infection (UTI) and hypercalciuria (r = 0.528, P = 0.017). Urinary citrate excretion showed a negative correlation with recurrent UTI (r = -0.503, P = 0.024). Hyperuricaciduria, hyperoxaluria were found to have no effect on the stone size and UTI of the patients. Stones were disintegrated with ESWL in two patients, endoscopic interventions were used in one patient and two underwent an open surgical procedure.

CONCLUSION

All children with nephrolithiasis should have a metabolic screen. Children with a positive family history and consanguinity should be followed carefully with respect to metabolic abnormalities.