Prevention of Intradialytic Hypotension in Patients with Acute Kidney Injury Submitted to Sustained Low-Efficiency Dialysis

Objectives: This study evaluated the effects of a protocol aiming to reduce hypotension in acute kidney injury (AKI) patients submitted to sustained low-efficiency dialysis (SLED). Methods: Patients were randomly assigned to two SLED prescriptions-control group, dialysate temperature was 37.0 degrees C with a fixed sodium concentration [138 mEq/L] and ultrafiltration (UF) rate; and profiling group, dialysate temperature was 35.5 degrees C with a variable sodium concentration [150-138 mEq/L] and UF rate. Results: Sixty-two SLED sessions were evaluated (34 in profiling and 28 in control). Patients (n = 31) were similar in terms of gender, age, and Sequential Organ Failure Assessment (SOFA) score. Dialysis time, dialysis dose, and post-dialysis serum sodium were similar in both groups. The profiling group had significantly less hypotension episodes (23% vs. 57% in control, p = 0.009) and achieved higher UF volume (2.23 +/- 1.25 L vs. 1.59 +/- 1.03 L in control, p = 0.04) when compared with control group. Conclusions: SLED protocol with modulation of dialysate temperature, sodium, and UF profiling showed similar efficacy but less intradialytic hypotension when compared with a standard SLED prescription.

Oxidative Stress and Modification of Renal Vascular Permeability Are Associated with Acute Kidney Injury during P. berghei ANKA Infection

Malaria associated-acute kidney injury (AKI) is associated with 45% of mortality in adult patients hospitalized with severe form of the disease. However, the causes that lead to a framework of malaria-associated AKI are still poorly characterized. Some clinical studies speculate that oxidative stress products, a characteristic of Plasmodium infection, as well as proinflammatory response induced by the parasite are involved in its pathophysiology. Therefore, we aimed to investigate the development of malaria-associated AKI during infection by P. berghei ANKA, with special attention to the role played by the inflammatory response and the involvement of oxidative stress. For that, we took advantage of an experimental model of severe malaria that showed significant changes in the renal pathophysiology to investigate the role of malaria infection in the renal microvascular permeability and tissue injury. Therefore, BALB/c mice were infected with P. berghei ANKA. To assess renal function, creatinine, blood urea nitrogen, and ratio of proteinuria and creatininuria were evaluated. The products of oxidative stress, as well as cytokine profile were quantified in plasma and renal tissue. The change of renal microvascular permeability, tissue hypoxia and cellular apoptosis were also evaluated. Parasite infection resulted in renal dysfunction. Furthermore, we observed increased expression of adhesion molecule, proinflammatory cytokines and products of oxidative stress, associated with a decrease mRNA expression of HO-1 in kidney tissue of infected mice. The measurement of lipoprotein oxidizability also showed a significant increase in plasma of infected animals. Together, our findings support the idea that products of oxidative stress, as well as the immune response against the parasite are crucial to changes in kidney architecture and microvascular endothelial permeability of BALB/c mice infected with P. berghei ANKA.

Chronic VEGF Blockade Worsens Glomerular Injury in the Remnant Kidney Model

VEGF inhibition can promote renal vascular and parenchymal injury, causing proteinuria, hypertension and thrombotic microangiopathy. The mechanisms underlying these side effects are unclear. We investigated the renal effects of the administration, during 45 days, of sunitinib (Su), a VEGF receptor inhibitor, to rats with 5/6 renal ablation (Nx). Adult male Munich-Wistar rats were distributed among groups S+V, sham-operated rats receiving vehicle only; S+Su, S rats given Su, 4 mg/kg/day; Nx+V, Nx rats receiving V; and Nx+Su, Nx rats receiving Su. Su caused no change in Group S. Seven and 45 days after renal ablation, renal cortical interstitium was expanded, in association with rarefaction of peritubular capillaries. Su did not worsen hypertension, proteinuria or interstitial expansion, nor did it affect capillary rarefaction, suggesting little angiogenic activity in this model. Nx animals exhibited glomerulosclerosis (GS), which was aggravated by Su. This effect could not be explained by podocyte damage, nor could it be ascribed to tuft hypertrophy or hyperplasia. GS may have derived from organization of capillary microthrombi, frequently observed in Group Nx+Su. Treatment with Su did not reduce the fractional glomerular endothelial area, suggesting functional rather than structural cell injury. Chronic VEGF inhibition has little effect on normal rats, but can affect glomerular endothelium when renal damage is already present.

Silent Ureteral Stones: Impact on Kidney Function-Can Treatment of Silent Ureteral Stones Preserve Kidney Function?

OBJECTIVE To report our experience with silent ureteral stones and expose their true influence on renal function. METHODS We analyzed 506 patients who had undergone ureterolithotripsy from January 2005 to May 2010. Silent ureteral stones were calculi found in the absence of any specific or subjective ureteral stone-related symptoms. Of the 506 patients, 27 (5.3%) met these criteria (global cohort). All patients were assessed postoperatively with dimercaptosuccinic acid scintigraphy (DMSA). A difference in relative kidney function of >10% was considered abnormal. Pre- and postoperative comparative DMSA analyses were electively obtained for 9 patients (kidney function cohort). A t test was used to assess the numeric variables, and the chi-square test or Fisher's exact test was used for categorical variables. Two-tailed P < .05 was considered statistically significant. RESULTS Stones were diagnosed by radiologic abdominal evaluation for nonurologic diseases in 40% and after previous nephrolithiasis treatment in 33%. The primary therapy was ureterolithotripsy in 88%. The mean follow-up time was 23 months. The overall ureteral stone-free rate after 1 and 2 procedures was 96% and 100%, respectively. In the global cohort, the mean pre- and postoperative serum creatinine levels were similar (P = .39), and the mean postoperative function on DMSA was 31%. In the kidney function cohort, no difference was found between the pre-and postoperative DMSA findings (22% +/- 12.1% vs 20% +/- 11.8%; P = .83) and serum creatinine (0.8 +/- 0.13 mg/dL vs 1.0 +/- 0.21 mg/dL; P = .45). CONCLUSION Silent ureteral stones are associated with decreased kidney function present at the diagnosis. Hydronephrosis tends to diminish after stone removal, and kidney function remains unaltered. UROLOGY 79: 304-309, 2012. (C) 2012 Elsevier Inc.

Long-Term Follow-Up of Patients after Acute Kidney Injury: Patterns of Renal Functional Recovery

Background and Objectives: Patients who survive acute kidney injury (AKI), especially those with partial renal recovery, present a higher long-term mortality risk. However, there is no consensus on the best time to assess renal function after an episode of acute kidney injury or agreement on the definition of renal recovery. In addition, only limited data regarding predictors of recovery are available. Design, Setting, Participants, & Measurements: From 1984 to 2009, 84 adult survivors of acute kidney injury were followed by the same nephrologist (RCRMA) for a median time of 4.1 years. Patients were seen at least once each year after discharge until end stage renal disease (ESRD) or death. In each consultation serum creatinine was measured and glomerular filtration rate estimated. Renal recovery was defined as a glomerular filtration rate value >= 60 mL/min/1.73 m2. A multiple logistic regression was performed to evaluate factors independently associated with renal recovery. Results: The median length of follow-up was 50 months (30-90 months). All patients had stabilized their glomerular filtration rates by 18 months and 83% of them stabilized earlier: up to 12 months. Renal recovery occurred in 16 patients (19%) at discharge and in 54 (64%) by 18 months. Six patients died and four patients progressed to ESRD during the follow up period. Age (OR 1.09, p < 0.0001) and serum creatinine at hospital discharge (OR 2.48, p = 0.007) were independent factors associated with non renal recovery. The acute kidney injury severity, evaluated by peak serum creatinine and need for dialysis, was not associated with non renal recovery. Conclusions: Renal recovery must be evaluated no earlier than one year after an acute kidney injury episode. Nephrology referral should be considered mainly for older patients and those with elevated serum creatinine at hospital discharge.

Histologic Inflammatory Changes on the Prostatic Gland Due to Immunosuppression for Kidney Transplantation

OBJECTIVE To determine the incidence of type IV prostatitis in patients with kidney transplantation receiving an immunosuppression regimen and to compare it with that of a nonimmunosuppressed control group. METHODS We retrospectively reviewed 216 electronic charts of patients who had undergone surgical treatment for benign prostatic hyperplasia from August 2000 to January 2006. Of the 216 patients, 183 did not receive immunosuppressive therapy and were included in the control group (group 1). The other 33 patients had undergone kidney transplantation and were included in the study group (group 2). The patient data were accessed for age at surgery, International Prostate Symptom Score, prostate volume, preoperative serum prostate-specific antigen level, history of acute urinary retention, and surgical approach (open vs transurethral resection of prostate). Histologic findings from the surgical specimens were also recorded. RESULTS The mean age at surgery, mean serum prostate-specific antigen level, mean prostate volume, and mean International Prostate Symptom Score were not significantly different between both groups. However, histologic evidence of chronic prostatitis was obtained in 145 surgical specimens (78%) from group 1 and in just 3 specimens from group 2 (9%; P < .001). Moreover, nonimmunosuppressed patients had a 38.2 times greater risk of presenting with prostatitis than did the immunosuppressed patients. CONCLUSION Imunnosuppresion therapy in kidney transplantation has a protective factor in the prostatitis incidence. UROLOGY 79: 662-664, 2012. (C) 2012 Elsevier Inc.

Lovastatin protects mithochondrial and renal function in kidney ischemia-reperfusion in rats

PURPOSE: To investigate the effect of lovastatin on renal ischemia followed by reperfusion. METHODS: Thirty one Wistar rats submitted to left renal ischemia for 60 minutes followed by contralateral nephrectomy were divided into two groups: A (n = 17, control, no treatment), and B (n = 14, lovastatin 15 mg/kg/day p.o. ten days before ischemia). The animals were sacrificed at the end of ischemia, after 24 hours and at seven days after reperfusion. Survival, serum urea and creatinine levels and renal mitochondrial function were evaluated. RESULTS: Mortality was 29.4% in group A and 0.7% in group B. Urea and creatinine levels were increased in both groups, but the values were significantly lower in group B. Mitochondrial function showed decoupling in 83.4% of group A, as opposed to 38.4/% of group B. CONCLUSIONS: The result shows a protective action of renal function by lovastatin administered before ischemia/reperfusion. Since most of the mitochondrial fraction presented membranes with the ability to maintain ATP production in group B, stabilization of the mitochondrial membrane should be considered as part of the protective action of lovastatin on renal function in ischemia/reperfusion.

Renal Function at Hospital Admission and Mortality Due to Acute Kidney Injury after Myocardial Infarction

Background: The role of an impaired estimated glomerular filtration rate (eGFR) at hospital admission in the outcome of acute kidney injury (AKI) after acute myocardial infarction (AMI) has been underreported. The aim of this study was to assess the influence of an admission eGFR<60 mL/min/1.73 m(2) on the incidence and early and late mortality of AMI-associated AKI. Methods: A prospective study of 828 AMI patients was performed. AKI was defined as a serum creatinine increase of >= 50% from the time of admission (RIFLE criteria) in the first 7 days of hospitalization. Patients were divided into subgroups according to their eGFR upon hospital admission (MDRD formula, mL/min/1.73 m(2)) and the development of AKI: eGFR >= 60 without AKI, eGFR<60 without AKI, eGFR >= 60 with AKI and eGFR<60 with AKI. Results: Overall, 14.6% of the patients in this study developed AKI. The admission eGFR had no impact on the incidence of AKI. However, the admission eGFR was associated with the outcome of AMI-associated AKI. The adjusted hazard ratios (AHR, Cox multivariate analysis) for 30-day mortality were 2.00 (95% CI 1.11-3.61) for eGFR, 60 without AKI, 4.76 (95% CI 2.45-9.26) for eGFR >= 60 with AKI and 6.27 (95% CI 3.20-12.29) for eGFR, 60 with AKI. Only an admission eGFR of <60 with AKI was significantly associated with a 30-day to 1-year mortality hazard (AHR 3.05, 95% CI 1.50-6.19). Conclusions: AKI development was associated with an increased early mortality hazard in AMI patients with either preserved or impaired admission eGFR. Only the association of impaired admission eGFR and AKI was associated with an increased hazard for late mortality among these patients.

Kidney of Minke Whale (Baleanoptera acutorostrata): Architecture and structure

Sarmento C. A. P., Ferreira A. O., Rodrigues E. A. F., Lesnau G. G., Rici R. E. G., Abreu D. K., Biasi C. & Miglino M. A. 2012. [Kidney of Minke Whale (Baleanoptera acutorostrata): Architecture and structure.] Rins de Baleia Minke (Baleanoptera acutorostrata): arquitetura e estrutura. Pesquisa Veterinaria Brasileira 32(8): 807-811. Departamento de Cirurgia, Setor de Anatomia dos Animais Domesticos e Silvestres, Universidade de Sao Paulo, Av. Prof. Dr. Orlando Marques de Paiva 87, Sao Paulo, SP 05508-270, Brazil. E-mail: sarmento@usp.br Among marine mammals, whale is one of the most attention-arousing animals, especially concerning its urinary tract. This system follows the pattern of mammals with regard to its constitution, however, it differs in renal morphology and number of lobes, which, in turn, form complete reniculi, agglutinated in hundreds. This structure is supported by fibrous connective tissue, but highly capable of maintaining electrolyte balance. Six pairs of kidneys of Minke whale (Balaenoptera acutorostrata), collected in 1982, in Cabedelo, Paraiba, Brazil, in the last fishing allowed, were dissected. These kidneys were preserved in 10% formaldehyde and they presented a very large histologic layer of collagen surrounding the medullary wall. The urinary collecting duct form papillary glasses, that reach a single collecting center which discharges in the ureter. It was found that the kidney of Minke whale has a lobe characteristic, with, on average, 700 reniculi; each reniculus has anatomical and functional characteristics of a unipyramidal kidney, with an inner layer (medulla), and an outer layer (cortex), and independent irrigation, with formation of individually arcuate arteries, as observed in unipyramidal terrestrial mammals. However, the set gathering all these reniculi constitutes, in the end, a multilobular and polipyramidal kidney, contrary to the morphology of most terrestrial mammals. It was not possible to distinguish the renicular cortex structures of the Minke whale in the level of light microscopy. Through scanning electron microscopy, it was possible to visualize a cortical layer located between two fibrous capsules. This joint, in turn, consists of connective tissue, which, along with a layer of collagen and elastic fibers, separates the cortex from the medulla; the kidney glomeruli were visualized, completely taken by the glomerular vessels and arranged into several layers. One notices that the glomerular cavity is almost a virtual space into which the glomerular filtrate is drained, and it does not present a globular shape. Vascularization is increased in the medullary region. The difference between the kidneys of terrestrial and marine mammals consists in the arrangement of morphological components, favoring the organ's physiology.

Single Center Experience With Elective Surgical Patients as Living Kidney Donors

Purpose. To report a single center experience with elective surgical patients as living kidney donors. Methods. We retrospectively analyzed a prospective database of 458 living kidney donors from September 2005 to May 2011. Fifteen (3.2%) of them were elective surgical patients simultaneously undergoing living donor nephrectomy. We reviewed age, gender, operative time, intraoperative blood transfusion, intra- and postoperative complications, as well as length of hospital stay. Recipients were evaluated for delayed graft function. Four hundred forty-three patients undergoing living donor nephrectomy alone composed the control group. Results. Among the elective surgical patients group, the mean (range) operative time was 155 (90 to 310) minutes and mean (range) length of hospital stay was 3 (2 to 9) days. One (6.7%) recipient displayed delayed graft function. Among the regular living kidney donors group, the mean (range) operative time was 100 (70 to 150) minutes, mean (range) length of hospital stay was 3 (2 to 5) days, and delayed graft function was observed in 5.6% of recipients. Only operative time (P = .03) was significantly different between the groups. Conclusions. Elective surgical patients are potential donors who may be treated at the same time as the living donor nephrectomy.

Lithiasis in 1,313 Kidney Transplants: Incidence, Diagnosis, and Management

Background. Renal transplantation remains the optimal treatment of patients with end-stage renal disease. Urinary lithiasis represents an unusual urologic complication in renal transplantation, with an incidence of <1%. Today, recipients of kidneys from deceased donors are more likely to receive grafts with undiagnosed lithiasis, which does not occur in patients from living donors, owing to screening with computerized tomography. Objective. The aim of this study was to evaluate the incidence, diagnosis, and therapeutic management of renal lithiasis in transplanted kidneys at a single institution. Methods. We reviewed the medical records for 1,313 patients who underwent kidney transplantation from February 1968 to February 2011. Results. Among the grafts, 17 patients (1.29%) had nephrolithiasis: 9 women and 8 men. Ages ranged from 32 to 63 years (mean = 45.6 years). Fifteen patients received kidneys from cadaveric and only 2 from living related donors. Two stones, both located inside the ureter, were identified during transplant surgery (11.7%). Three instances of lithiasis were incidentally diagnosed by ultrasound during graft evaluation, within 7 days after surgery (17.6%); all 3 were in the calyces. The 12 remaining patients had the stones diagnosed later (70.58%): 6 in the calyces, 3 in the renal pelvis, and 3 inside the ureter. Conclusions. Urinary lithiasis is a rare complication in renal transplantation. In most patients the condition occurs without pain. The diagnosis and treatment options for graft urolithiasis are similar to those patients with nephrofithiasis in the general population. Extracorporeal shock wave lithotripsy (ESWL) was the most common treatment method.

Religious/spiritual coping in people with chronic kidney disease undergoing hemodialysis

The objective of the present study is to investigate the use of religious/spiritual coping mechanisms in patients with chronic kidney disease undergoing hemodialysis, by means of interviews using a sociodemographic questionnaire and the religious/spiritual coping scale. Data analysis was performed using descriptive statistics and multiple linear regression. A total of 123 individuals were interviewed, 79.6% of whom presented a high score for religious/spiritual coping and none of whom presented low or irrelevant scores. The variables that affected the religious/spiritual coping behavior were: gender, age group, treatment time, family income, and religious practice. In conclusion, the participants used religious/spiritual coping mechanisms as a strategy to cope with the disease, particularly women with a higher family income who attend church every week.

Cellular Infiltrates and NF kappa B Subunit c-Rel Signaling in Kidney Allografts of Patients With Clinical Operational Tolerance

Background. Nuclear factor kappa B (NF kappa B) plays a potential role in tolerance by orchestrating onset and resolution of inflammation and regulatory T cell differentiation through subunit c-Rel. We characterized cellular infiltrates and expression of NF kappa B1, c-Rel and its upstream regulators phosphatidylinositol 3-kinase/RAC-alpha serine/threonine kinase, in allograft biopsies from patients with spontaneous clinical operational tolerance (COT). Methods. Paraffin-fixed kidney allograft biopsies from 40 patients with COT (n=4), interstitial rejection (IR; n=12), borderline changes (BC; n=12), and long-term allograft function without rejection (NR; n=12) were used in the study. Cellular infiltrates and immunohistochemical expression of key proteins of the NF kappa B pathway were evaluated in the cortical tubulointerstitium and in cellular infiltrates using digital image analysis software. Results were given as mean +/- SEM. Results. Biopsies from patients with COT exhibited a comparable amount of cellular infiltrate to IR, BC, and NR (COT, 191 +/- 81; IR, 291 +/- 62; BC, 178 +/- 45; and NR, 210 +/- 42 cells/mm(2)) but a significantly higher proportion of forkhead box P3-positive cells (COT, 11%+/- 1.7%; IR, 3.5%+/- 0.70%; BC, 3.4%+/- 0.57%; and NR, 3.7%+/- 0.78% of infiltrating cells; P=0.02). c-Rel expression in cellular infiltrates was significantly elevated in IR, BC, and NR when analyzing the number of positive cells per mm(2) (P=0.02) and positive cells per infiltrating cells (P=0.04). In contrast, tubular PI3K and c-Rel expression were significantly higher in IR and BC but not in NR compared with COT (P=0.03 and P=0.006, respectively). With RAC-alpha serine-threonine kinase, similar tendencies were observed (P=0.2). Conclusions. Allografts from COT patients show significant cellular infiltrates but a distinct expression of proteins involved in the NF kappa B pathway and a higher proportion of forkhead box P3-positive cells.

N-acetylcysteine prevents pulmonary edema and acute kidney injury in rats with sepsis submitted to mechanical ventilation

Campos R, Shimizu MH, Volpini RA, de Bragan a AC, Andrade L, Lopes FD, Olivo C, Canale D, Seguro AC. N-acetylcysteine prevents pulmonary edema and acute kidney injury in rats with sepsis submitted to mechanical ventilation. Am J Physiol Lung Cell Mol Physiol 302: L640-L650, 2012. First published January 20, 2012; doi: 10.1152/ajplung.00097.2011.-Sepsis is a common cause of acute kidney injury (AKI) and acute lung injury. Oxidative stress plays as important role in such injury. The aim of this study was to evaluate the effects that the potent antioxidant N-acetylcysteine (NAC) has on renal and pulmonary function in rats with sepsis. Rats, treated or not with NAC (4.8 g/l in drinking water), underwent cecal ligation and puncture (CLP) 2 days after the initiation of NAC treatment, which was maintained throughout the study. At 24 h post-CLP, renal and pulmonary function were studied in four groups: control, control + NAC, CLP, and CLP + NAC. All animals were submitted to low-tidal-volume mechanical ventilation. We evaluated respiratory mechanics, the sodium cotransporters Na-K-2Cl (NKCC1) and the alpha-subunit of the epithelial sodium channel (alpha-ENaC), polymorphonuclear neutrophils, the edema index, oxidative stress (plasma thiobarbituric acid reactive substances and lung tissue 8-isoprostane), and glomerular filtration rate. The CLP rats developed AKI, which was ameliorated in the CLP + NAC rats. Sepsis-induced alterations in respiratory mechanics were also ameliorated by NAC. Edema indexes were lower in the CLP + NAC group, as was the wet-to-dry lung weight ratio. In CLP + NAC rats, alpha-ENaC expression was upregulated, whereas that of NKCC1 was downregulated, although the difference was not significant. In the CLP + NAC group, oxidative stress was significantly lower and survival rates were significantly higher than in the CLP group. The protective effects of NAC (against kidney and lung injury) are likely attributable to the decrease in oxidative stress, suggesting that NAC can be useful in the treatment of sepsis.

Hyperbaric Oxygen Therapy Induces Kidney Protection in an Ischemia/Reperfusion Model in Rats

Ischemia/reperfusion (I/R) injury remains a major cause of graft dysfunction, which impacts short- and long-term follow-up. Hyperbaric oxygen therapy (HBO), through plasma oxygen transport, has been currently used as an alternative treatment for ischemic tissues. The aim of this study was to analyze the effects of HBO on kidney I/R injury model in rats, in reducing the harmful effect of I/R. The renal I/R model was obtained by occluding bilateral renal pedicles with nontraumatic vascular clamps for 45 minutes, followed by 48 hours of reperfusion. HBO therapy was delivered an hypebaric chamber (2.5 atmospheres absolute). Animals underwent two sessions of 60 minutes each at 6 hours and 20 hours after initiation of reperfusion. Male Wistar rats (n = 38) were randomized into four groups: sham, sham operated rats; Sham+HBO, sham operated rats exposed to HBO; I/R, animals submitted to I/R; and I/R+HBO, I/R rats exposed to HBO. Blood, urine, and kidney tissue were collected for biochemical, histologic, and immunohistochemical analyses. The histopathological evaluation of the ischemic injury used a grading scale of 0 to 4. HBO attenuated renal dysfunction after ischemia characterized by a significant decrease in blood urea nitrogen (BUN), serum creatinine, and proteinuria in the I/R+HBO group compared with I/R alone. In parallel, tubular function was improved resulting in significantly lower fractional excretions of sodium and potassium. Kidney sections from the I/R plus HBO group showed significantly lower acute kidney injury scores compared with the I/R group. HBO treatment significantly diminished proliferative activity in I/R (P < .05). There was no significant difference in macrophage infiltration or hemoxygenase-1 expression. In conclusion, HBO attenuated renal dysfunction in a kidney I/R injury model with a decrease in BUN, serum creatinine, proteinuria, and fractional excretion of sodium and potassium, associated with reduced histological damage.