Effect of uric acid reduction on chronic kidney disease. Systematic review and meta-analysis.

Accumulating evidence suggests that hyperuricemia is a pathological factor in the development and progression of chronic kidney disease. However, the potential benefit afforded by the control of uric acid (UA) is controversial. Individual studies show discrepant results, and most existing meta-analysis, especially those including the larger number of studies, lack a placebo or control group as they aim to compare efficacy between drugs. On these grounds, we performed a me-ta-analysis restricted to studies including the action of any anti-gout therapies referenced to a control or placebo arm. This approach allows for a clearer association between UA reduction and renal effect. Of the twenty-nine papers included, most used allopurinol and febuxostat and, therefore, solid conclusions could only be obtained for these drugs. Both were very effective in reducing UA, but only allopurinol was able to significantly improve glomerular filtration rate (GFR), although not in a dose-dependent manner. These results raised doubts as to whether it is the hypouricemic effect of anti-gout drugs, or a pleiotropic effect, what provides protection of kidney function. Accordingly, in a correlation study that we next performed between UA reduction and GFR improvement, no association was found, which suggests that additional mechanisms may be involved. Of note, most trials show large inter-individual response variability, probably because they included patients with heterogeneous phenotypes and pathological characteristics, including different stages of CKD and comorbidities. This highlights the need to sub classify the effect of UA-lowering therapies according to the pathological scenario, in order to identify those CKD patients that may benefit most from them. Systematic Review Registration: CRD42022306646 https://www.crd.york.ac.uk/prospero/.

New Challenges in the Diagnosis of Kidney Damage Due to Immune Checkpoint Inhibitors Therapy: An Observational Clinical Study.

In recent years, immunotherapy has been postulated as one of the most effective strategies in the fight against cancer. The greatest success in this field has been achieved with the inhibition of molecules involved in slowing down the adaptive immune response by immune checkpoint inhibitors (ICIs). Despite its efficacy, ICI treatment has side effects. Regarding kidney damage, it is estimated that 4.9% of patients treated with ICIs develop renal injury. Furthermore, cancer patients who develop renal dysfunction have a worse prognosis. Current diagnostics are insufficient to predict the underlying renal injury and to identify the type of damage. Our hypothesis is that the renal injury could be subclinical, so the possibility of using new urinary biomarkers could be a useful diagnostic tool that would allow these patients to be managed in a preventive (risk biomarkers) and early (early biomarkers) way and even to clarify whether the renal damage is due to this therapy or to other factors (differential diagnostic biomarkers). A prospective study to validate risk and early and differential biomarkers in patients treated with ICIs is proposed to test this hypothesis. The results derived from this study will improve the clinical practice of cancer treatment with ICIs and therefore the life expectancy and quality of life of patients. Trial Registration: ClinicalTrials.gov, NCT04902846.

Diagnosis of Cardiac Surgery-Associated Acute Kidney Injury: State of the Art and Perspectives.

Diagnosis of cardiac surgery-associated acute kidney injury (CSA-AKI), a syndrome of sudden renal dysfunction occurring in the immediate post-operative period, is still sub-optimal. Standard CSA-AKI diagnosis is performed according to the international criteria for AKI diagnosis, afflicted with insufficient sensitivity, specificity, and prognostic capacity. In this article, we describe the limitations of current diagnostic procedures and of the so-called injury biomarkers and analyze new strategies under development for a conceptually enhanced diagnosis of CSA-AKI. Specifically, early pathophysiological diagnosis and patient stratification based on the underlying mechanisms of disease are presented as ongoing developments. This new approach should be underpinned by process-specific biomarkers including, but not limited to, glomerular filtration rate (GFR) to other functions of renal excretion causing GFR-independent hydro-electrolytic and acid-based disorders. In addition, biomarker-based strategies for the assessment of AKI evolution and prognosis are also discussed. Finally, special focus is devoted to the novel concept of pre-emptive diagnosis of acquired risk of AKI, a premorbid condition of renal frailty providing interesting prophylactic opportunities to prevent disease through diagnosis-guided personalized patient handling. Indeed, a new strategy of risk assessment complementing the traditional scores based on the computing of risk factors is advanced. The new strategy pinpoints the assessment of the status of the primary mechanisms of renal function regulation on which the impact of risk factors converges, namely renal hemodynamics and tubular competence, to generate a composite and personalized estimation of individual risk.

Early Diagnosis of Kidney Damage Associated with Tobacco Use: Preventive Application.

Although long-term smoking has been associated with chronic kidney disease, its effect on kidney function in early stages has not been clarified. Therefore, the proposed objectives were: (1) to identify subclinical kidney damage in smokers, through a panel of biomarkers; (2) to evaluate the progression of subclinical kidney damage after two years of consumption in these patients; and (3) study whether quitting smoking reduces kidney damage. A prospective study was carried out (patients recruited from a primary care centre and a clinical smoking unit). Kidney function was assessed using a panel of biomarkers and compared between smokers and non-smokers, taking into account potential risk factors for kidney damage. These results show, for the first time in the literature, the relationship between smoking and early (subclinical) kidney damage and provide a panel of biomarkers capable of detecting this condition (Neutrophil gelatinase-associated lipocalin, Kidney injury molecule-1, N-acetyl-beta-D-glucosaminidase, transferrin, and ganglioside-activating protein GM2). This study also indicates that subclinical damage is maintained when use continues, but can be reversed if patients stop smoking. The use of these biomarkers as diagnostic tools can be a preventive measure in the development of chronic kidney disease associated with smoking and in the prevention of acute events associated with potentially nephrotoxic pharmacological treatment in smokers. Trial registration number: NCT03850756.

Are Antioxidants Useful in Preventing the Progression of Chronic Kidney Disease?

Chronic kidney disease (CKD) is a progressive impairment of renal function for more than three months that affects 15% of the adult population. Because oxidative stress is involved in its pathogenesis, antioxidants are under study for the prophylaxis of CKD progression. The objective of this work was to meta-analyze the efficacy of antioxidant therapy in CKD patients and to identify the most effective candidate antioxidants. Our meta-analysis showed that, despite being quite heterogeneous, overall antioxidant therapy apparently reduced CKD progression. Pentoxifylline and bardoxolone methyl demonstrated a robust and statistically significant protection, while other products showed a favorable but non-significant tendency, due to a high interindividual variability. Off-target (i.e., antioxidant-independent) effects, such as body weight reduction and heart failure-associated blood dilution, might totally or partially explain the protection provided by effective antioxidants. This potential pleiotropy introduces uncertainty on the role of oxidative stress in CKD progression and on antioxidant therapy in its prevention, which needs to be further investigated. Independently, identification of factors determining the nephroprotective effect of each candidate on each patient is thus necessary for a prospectively personalized antioxidant therapy. Finally, pentoxifylline should be further explored for the prophylaxis of CKD progression.

Albuminuria Pre-Emptively Identifies Cardiac Patients at Risk of Contrast-Induced Nephropathy.

Contrast-induced nephropathy (CIN) is a complication associated with the administration of contrast media (CM). The CIN diagnosis is based on creatinine, a biomarker late and insensitive. The objective proposed was to evaluate the ability of novel biomarkers to detect patients susceptible to suffering CIN before CM administration. The study was carried out with patients undergoing cardiac catheterization involving CM. Patients were divided into two groups: (1) CIN, patients who developed this pathology; (2) control, patients who did not suffer CIN. Prior to the administration of CM, urine samples were collected to measure proteinuria, N-acetyl-ß-d-glucosaminidase, neutrophil gelatinase-associated lipocalin and kidney injury molecule-1, albumin, transferrin, t-gelsolin and GM2 ganglioside activator protein (GM2AP). The risk factors advanced age, low body mass index and low estimated glomerular filtration rate; and the urinary biomarkers albumin, transferrin and GM2AP showed significant predictive capacity. Of all of them, albuminuria demonstrated the highest diagnostic power. When a cutoff point was established for albuminuria at values still considered subclinical (10-30 µg/mg Cru), it was found that there was a high incidence of CIN (40-75%). Therefore, albuminuria could be applied as a new diagnostic tool to prevent and predict CIN with P4 medicine criteria, independently of risk factors and comorbidities.

Regression Modeling of the Antioxidant-to-Nephroprotective Relation Shows the Pivotal Role of Oxidative Stress in Cisplatin Nephrotoxicity.

The clinical utility of the chemotherapeutic drug cisplatin is significantly limited by its nephrotoxicity, which is characterized by electrolytic disorders, glomerular filtration rate decline, and azotemia. These alterations are consequences of a primary tubulopathy causing injury to proximal and distal epithelial cells, and thus tubular dysfunction. Oxidative stress plays a role in cisplatin nephrotoxicity and cytotoxicity, but its relative contribution to overall toxicity remains unknown. We studied the relation between the degree of oxidative reduction (provided by antioxidant treatment) and the extent of nephrotoxicity amelioration (i.e., nephroprotection) by means of a regression analysis of studies in animal models. Our results indicate that a linear relation exists between these two parameters, and that this relation very nearly crosses the value of maximal nephroprotection at maximal antioxidant effect, suggesting that oxidative stress seems to be a pivotal and mandatory mechanism of cisplatin nephrotoxicity, and, hence, an interesting, rationale-based target for clinical use. Our model also serves to identify antioxidants with enhanced effectiveness by comparing their actual nephroprotective power with that predicted by their antioxidant effect. Among those, this study identified nanoceria, erythropoietin, and maltol as highly effective candidates affording more nephroprotection than expected from their antioxidant effect for prospective clinical development.

A meta-analysis of preclinical studies using antioxidants for the prevention of cisplatin nephrotoxicity: implications for clinical application.

Cisplatin is an effective chemotherapeutic drug whose clinical use and efficacy are limited by its nephrotoxicity, which affects mainly the renal tubules and vasculature. It accumulates in proximal and distal epithelial tubule cells and causes oxidative stress-mediated cell death and malfunction. Consequently, many antioxidants have been tested for their capacity to prevent cisplatin nephrotoxicity. In this study, we made a systematic review of the literature and meta-analyzed 152 articles, which tested the nephroprotective effect of isolated compounds or mixtures of natural origin on cisplatin nephrotoxicity in preclinical models. This meta-analysis identified the most effective candidates and examined the efficacy obtained by antioxidants administered by the oral and intraperitoneal routes. By comparing with a recent, similar meta-analysis performed on clinical studies, this article identifies a disconnection between preclinical and clinical research, and contextualizes, discusses, and integrates the existing preclinical information toward the optimized selection of candidates to be further explored (clinical level). Despite proved efficacy, this article discusses the barriers limiting the clinical development of natural mixtures, such as those in extracts from Calendula officinalis flowers and Heliotropium eichwaldii roots. On the contrary, isolated compounds are more straightforward candidates, among which arjunolic acid and quercetin stand out in this meta-analysis.

Pathophysiological mechanisms underlying a rat model of triple whammy acute kidney injury.

Simultaneous administration of certain antihypertensive (renin-angiotensin system inhibitors and diuretics) and nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with a renal toxicity syndrome known as "triple whammy" acute kidney injury (TW-AKI), yet poorly characterized at the pathophysiological level, as no specific experimental model exists on which to conduct preclinical research. Herein, we generated and characterized a rat model of TW-AKI (0.7 mg/kg/day trandolapril +400 mg/kg/day ibuprofen +20 mg/kg/day furosemide). Double treatments involving the NSAID caused a subclinical acute kidney injury, as they reduced glomerular filtration rate to a significant but not sufficient extent to increase Crpl concentration. Only the triple treatment generated an overt AKI with increased Crpl provided that animals were under partial water ingestion restriction. Histological examination revealed no evidence of tissue renal injury, and no proteinuria or makers of renal damage were detected in the urine. These findings, along with a normal fractional excretion of sodium and glucose, indicated that these drug combinations produce a prerenal type of AKI. In fact, blood pressure and renal blood flow were also reduced (most markedly following the triple combination), although renal dysfunction was more pronounced than expected for the corresponding pressure drop, supporting a key pathological role of the interference with renal autoregulation mechanisms. In summary, prerenal TW-AKI only occurs when volemia is challenged (i.e., by furosemide in partially water-deprived animals) under the effects of renin-angiotensin system inhibitors and NSAIDs. This model will facilitate further pathophysiological knowledge for a better diagnosis and clinical handling of this syndrome.

Designing new diagnostic systems for the early detection of tobacco-associated chronic renal damage in patients of a primary care centre in Salamanca, Spain: an observational, prospective study protocol.

INTRODUCTION: Tobacco causes kidney damage that can progress to chronic kidney disease. However, the diagnostic parameters used in clinics are not effective in identifying smokers at risk. Our first objective is to more effectively detect subclinical renal damage in smokers. In addition, we hypothesise that tobacco consumption can predispose smokers to renal damage on exposure to other potentially nephrotoxic events (drugs, diagnostic procedures and so on). We will test this hypothesis in our second objective by investigating whether certain predisposition markers (GM2 ganglioside activator protein (GM2AP), transferrin and t-gelsolin) are able to detect smokers who are predisposed to kidney damage. Finally, in our third objective, we will study whether smoking cessation reduces subclinical and/or predisposition to renal damage. METHODS AND ANALYSIS: For our first objective, a prospective cross-sectional study will be carried out with patients from a primary healthcare centre. The influence of tobacco on renal damage, in patients both with and without additional risk factors, will be studied using a panel of early biomarkers (albuminuria, N-acetyl-beta-D-glucosaminidase, kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin). For our second objective, a prospective longitudinal study will be carried out with patients recruited for our first objective. We will study whether certain predisposition biomarkers (GM2AP, transferrin and t-gelsolin) are able to detect smokers predisposed to renal damage. For our third objective, a prospective longitudinal study will be carried out with patients from a smoking cessation unit. We will study the evolution of the markers described above following smoking cessation. ETHICS AND DISSEMINATION: The study has been approved by the Clinical Research Ethics Committee of the Healthcare Area of Salamanca. All study participants will sign an informed consent form in compliance with the Declaration of Helsinki and the WHO standards for observational studies. Results will be presented at conferences and submitted to peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT03850756.

Systematic review and meta-analysis of the efficacy of clinically tested protectants of cisplatin nephrotoxicity.

INTRODUCTION: Cisplatin is a potent antineoplastic drug that has been widely used to treat a number of solid tumors. However, a high incidence of renal damage observed in patients has led researchers to search for alternate strategies that prevent or at least reduce the cisplatin-induced nephrotoxicity. The objective of the present study was to conduct a systematic review and a subsequent meta-analysis to evaluate and identify compounds with effective antitumor activity and lesser side effects that could provide protection against cisplatin-induced nephrotoxicity. METHODS: The study included all placebo-controlled trials published up to December 2017 that met the inclusion criteria. A total of 22 articles were finally included to extract the following information: number of patients, doses of cisplatin and protectant, qualitative (acute kidney injury incidence) and quantitative (plasma creatinine, blood urea nitrogen, and creatinine clearance) indicators of renal function. The odds ratio or the mean difference (95% confidence interval) of each parameter was calculated for each study and group of studies. RESULTS: The results of this meta-analysis show that there is great variability in the nephroprotective capacity of a variety of products evaluated. Of all the compounds tested, only magnesium sulfate and cystone were found to exert protective effects. However, more studies need to be conducted to confirm these results. CONCLUSIONS: The administration of 1 g of Mg i.v. seems to be the best strategy for the prevention of cisplatin nephrotoxicity.

Urinary transferrin pre-emptively identifies the risk of renal damage posed by subclinical tubular alterations.

Nephrotoxicity is an important limitation to the clinical use of many drugs and contrast media. Drug nephrotoxicity occurs in acute, subacute and chronic manifestations ranging from glomerular, tubular, vascular and immunological phenotypes to acute kidney injury. Pre-emptive risk assessment of drug nephrotoxicity poses an urgent need of precision medicine to optimize pharmacological therapies and interventional procedures involving nephrotoxic products in a preventive and personalized manner. Biomarkers of risk have been identified in animal models, and risk scores have been proposed, whose clinical use is abated by their reduced applicability to specific etiological models or clinical circumstances. However, our present data suggest that the urinary level of transferrin may be indicative of risk of renal damage, where risk is induced by subclinical tubular alterations regardless of etiology. In fact, urinary transferrin pre-emptively correlates with the subsequent renal damage in animal models in which risk has been induced by drugs and toxins affecting the renal tubules (i.e. cisplatin, gentamicin and uranyl nitrate); whereas transferrin shows no relation with the risk posed by a drug affecting renal hemodynamics (i.e. cyclosporine A). Our experiments also show that transferrin increases in the urine in the risk state (i.e. prior to the damage) precisely as a consequence of reduced tubular reabsorption. Finally, urinary transferrin pre-emptively identifies subpopulations of oncological and cardiac patients at risk of nephrotoxicity. In perspective, urinary transferrin might be further explored as a wider biomarker of an important mechanism of predisposition to renal damage induced by insults causing subclinical tubular alterations.

Quercetin, a Promising Clinical Candidate for The Prevention of Contrast-Induced Nephropathy.

Iodinated contrast media (CM) are the leading cause of acute renal failure of toxic origin. Between 21% and 50% of patients that receive them develop contrast-induced nephropathy (CIN). All prophylactic measures used so far have failed to provide effective prevention. Since oxidative stress is involved in the damage, a possible preventive strategy could be the administration of antioxidant substances, such as quercetin. This compound has shown renoprotective effects in experimental studies. The aim of this study was to evaluate whether quercetin may be helpful in preventing CIN in patients undergoing coronary catheterization. A clinical phase II study was conducted. Patients were distributed in two groups, namely, CM (patients who only received contrast media) and CM+Q (patients who were pretreated with quercetin orally for 3-5 days). Results showed less incidence of CIN in the CM+Q group, possibly due to glomerular protection, evidenced by a lower increase in serum creatinine and albuminuria; and a lower decrease in the glomerular filtration rate (GFR). Furthermore, in this group, the relative risk of developing CIN observed in patients that received a high dose of contrast media was inferior. In conclusion, this is the first study that demonstrates that quercetin is a promising safe candidate in preventing CIN.

Key role of oxidative stress in animal models of aminoglycoside nephrotoxicity revealed by a systematic analysis of the antioxidant-to-nephroprotective correlation.

The clinical utility of aminoglycoside antibiotics is partly limited by their nephrotoxicity. Co-administration of a variety of candidate nephroprotectants has been tested at the preclinical level. According to a recent meta-analytic study, antioxidants are the only family of compounds with enough preclinical documentation to draw solid conclusions on their class nephroprotective capacity in animal models. In this study a systematic analysis of the relation between the level of antioxidation and the level of nephroprotection was performed. A regression model is presented which crosses the y-axis (i.e. the axis representing the level of nephroprotection) very nearly the zero value, meaning that maximal prevention of the oxidative stress induced by aminoglycosides results in almost maximal nephroprotection. This indicates that oxidative stress plays a central role in the hierarchy of pathophysiological mechanisms underlying aminoglycoside nephrotoxicity. In addition, this model may potentially serve: i) as a standard to evaluate the role of the antioxidant effect of candidate nephroprotectants; ii) to reveal additional, antioxidant-independent effects among those compounds providing more nephroprotection than that expected from its antioxidant activity; and thus iii) to discriminate and focus most effective nephroprotectants on clinical usage.

A systematic meta-analysis on the efficacy of pre-clinically tested nephroprotectants at preventing aminoglycoside nephrotoxicity.

Nephrotoxicity limits the use of aminoglycoside antibiotics. Kidney damage is produced mainly in the renal tubule due to an inflammatory and oxidative process. At preclinical level, many drugs and natural products have been tested as prospective protectors of aminoglycoside nephrotoxicity. The main objective of this work was to make a systematic literature review of preclinical studies about aminoglycoside nephrotoxicity protection and a statistical analysis based on the meta-analysis methodology. Studies published up to January 2016 were identified. After applying inclusion criteria, 54 studies were chosen. The size of the experimental groups, means and standard deviations of data on renal function (i.e. plasma creatinine and blood urea nitrogen [BUN] concentrations) were extracted and registered in a database. The studies were grouped according to the mechanism of nephroprotection and their route of administration. The Mean Difference (95% confidence interval) was calculated for each study and group. 40 of 54 products tested produced an amelioration of aminoglycoside nephrotoxicity based on creatinine results. Also a dose dependent protective effect was observed (both in creatinine and BUN). Products orally administered were more effective than via i.p. Products with attributed antioxidant activity were the most used and those which proved statistically significant nephroprotection as a class effect. Aminoglycoside tubular reuptake inhibitors, excretion inducers and calcium channel blockers also showed a promising and rather homogeneous class tendency towards nephroprotection, although more research is necessary to obtain solid and conclusive results, based on a larger number of studies.

Sub-nephrotoxic cisplatin sensitizes rats to acute renal failure and increases urinary excretion of fumarylacetoacetase.

Nephrotoxicity limits the therapeutic efficacy of the antineoplastic drug cisplatin. Due to dosage adjustment and appropriate monitoring, most therapeutic courses with cisplatin produce no or minimal kidney damage. However, we studied whether even sub-nephrotoxic dosage of cisplatin poses a potential risk for the kidneys by predisposing to acute kidney injury (AKI), specifically by lowering the toxicity threshold for a second nephrotoxin. With this purpose rats were treated with a single sub-nephrotoxic dosage of cisplatin (3mg/kg, i.p.) and after two days, with a sub-nephrotoxic regime of gentamicin (50mg/kg/day, during 6 days, i.p.). Control groups received only one of the drugs or the vehicle. Renal function and renal histology were monitored throughout the experiment. Cisplatin treatment did not cause any relevant functional or histological alterations in the kidneys. Rats treated with cisplatin and gentamicin, but not those under single treatments, developed an overt renal failure characterized by both renal dysfunction and massive tubular necrosis. In addition, the urinary excretion of fumarylacetoacetase was increased in cisplatin-treated animals at subtoxic doses, which might be exploited as a cisplatin-induced predisposition marker. In fact, the urinary level of fumarylacetoacetase prior to the second nephrotoxin correlated with the level of AKI triggered by gentamicin in predisposed animals.

Increased urinary excretion of albumin, hemopexin, transferrin and VDBP correlates with chronic sensitization to gentamicin nephrotoxicity in rats.

Drug nephrotoxicity is a serious health and economic problem worldwide. Rats can be acutely sensitized to acute kidney injury (AKI) by subnephrotoxic treatments with potentially nephrotoxic drugs. Acquired sensitization to AKI poses a silent risk impossible to diagnose pre-emptively with the technology available at the clinical level. Herein, we hypothesized whether a chronic, subnephrotoxic insult to the kidneys might result in chronically acquired sensitization to AKI, and whether chronic sensitization might be detected through specific urinary markers. To this end, rats were treated with a subtoxic dosage of the experimental nephrotoxin uranyl nitrate (UN) in the drinking water for 21 weeks, or plain water (as control), and then with low-dose gentamicin for 7 days. Renal function and renal tissue damage were evaluated through the experiment. The mild renal damage caused by gentamicin was markedly magnified in rats having received UN chronically, which was evident both at the functional and histological level. Four proteins, namely albumin, hemopexin, transferrin and vitamin D binding protein were increased in the urine in temporal association with the appearance of chronic predisposition. Although further studies are necessary, our results suggest that these proteins might be potentially used as markers of hidden, chronic predisposition to gentamicin nephrotoxicity, in order to appropriately and pre-emptively stratify and handle individuals according to their specific risk in the long term, and to conveniently optimize their life conditions or additional clinical procedures or treatments that might trigger the disease. This might reduce AKI incidence and severity and the associated costs.

An integrative overview on the mechanisms underlying the renal tubular cytotoxicity of gentamicin.

Gentamicin is an aminoglycoside antibiotic widely used against infections by Gram-negative microorganisms. Nephrotoxicity is the main limitation to its therapeutic efficacy. Gentamicin nephrotoxicity occurs in 10-20% of therapeutic regimes. A central aspect of gentamicin nephrotoxicity is its tubular effect, which may range from a mere loss of the brush border in epithelial cells to an overt tubular necrosis. Tubular cytotoxicity is the consequence of many interconnected actions, triggered by drug accumulation in epithelial tubular cells. Accumulation results from the presence of the endocytic receptor complex formed by megalin and cubulin, which transports proteins and organic cations inside the cells. Gentamicin then accesses and accumulates in the endosomal compartment, the Golgi and endoplasmic reticulum (ER), causes ER stress, and unleashes the unfolded protein response. An excessive concentration of the drug over an undetermined threshold destabilizes intracellular membranes and the drug redistributes through the cytosol. It then acts on mitochondria to unleash the intrinsic pathway of apoptosis. In addition, lysosomal cathepsins lose confinement and, depending on their new cytosolic concentration, they contribute to the activation of apoptosis or produce a massive proteolysis. However, other effects of gentamicin have also been linked to cell death, such as phospholipidosis, oxidative stress, extracellular calcium-sensing receptor stimulation, and energetic catastrophe. Besides, indirect effects of gentamicin, such as reduced renal blood flow and inflammation, may also contribute or amplify its cytotoxicity. The purpose of this review was to critically integrate all these effects and discuss their relative contribution to tubular cell death.

Nephrotoxicity of uranium: pathophysiological, diagnostic and therapeutic perspectives.

As in the case of other heavy metals, a considerable body of evidence suggests that overexposure to uranium may cause pathological alterations to the kidneys in both humans and animals. In the present work, our aim was to analyze the available data from a critical perspective that should provide a view of the real danger of the nephrotoxicity of this metal for human beings. A further aim was to elaborate a comparative compilation of the renal pathophysiological data obtained in humans and experimental animals with a view to gaining more insight into our knowledge of the mechanisms of action and renal damage. Finally, we address the existing perspectives for the improvement of diagnostic methods and the treatment of intoxications by uranium, performing an integrated analysis of all these aspects.