A nitric oxide-donor furoxan moiety improves the efficacy of edaravone against early renal dysfunction and injury evoked by ischemia/reperfusion.

Edaravone (5-methyl-2-phenyl-2,4-dihydro-3H-pyrazol-3-one, EDV) is a free-radical scavenger reduces organ ischemic injury. Here we investigated whether the protective effects of EDV in renal ischemia/reperfusion (I/R) injury may be enhanced by an EDV derivative bearing a nitric oxide- (NO-) donor furoxan moiety (NO-EDV). Male Wistar rats were subjected to renal ischemia (45 minutes), followed by reperfusion (6 hours). Administration of either EDV (1.2-6-30 µmol/kg, i.v.) or NO-EDV (0.3-1.2-6 µmol/kg, i.v.) dose-dependently attenuated markers of renal dysfunction (serum urea and creatinine, creatinine clearance, urine flow, urinary N-acetyl-ß-D-glucosaminidase, and neutrophil gelatinase-associated lipocalin/lipocalin-2). NO-EDV exerted protective effects in the dose-range 1.2-6 µmol/kg, while a higher dose (30 µmol/kg) was needed to obtain protection by EDV. Both EDV and NO-EDV modulated tissue markers of oxidative stress and lipid peroxidation. NO-EDV, but not EDV, activated endothelial NO synthase (NOS) and blunted I/R-induced upregulation of inducible NOS, secondary to modulation of Akt and NF-κB activation, respectively. Besides NO-EDV administration inhibited I/R-induced IL-1ß, IL-18, IL-6, and TNF-α overproduction. Overall, these findings demonstrate that the NO-donor moiety contributes to the protection against early renal I/R injury and suggest that NO-donor EDV codrugs are worthy of additional study as innovative pharmacological tools.

Garlic supplemented diet attenuates gentamicin nephrotoxicity in rats.

PURPOSE: To demonstrate the effect of a 4% pulverized garlic supplemented diet on the nephrotoxicity induced by gentamicin in rats. MATERIALS AND METHODS: Twenty four healthy male Wistar rats, weighing between 220 - 260 grams, were divided into three groups. The rats were randomly assigned to either the gentamicin injection without garlic supplementation group (Group I, n = 8), gentamicin injection with garlic supplementation group (Group II, n = 8), and control group (Group III, n = 8). Urine from the rats was collected and the volume (mL), microalbumin (mg/L), creatinine (mg/dL), Na (mmol/L), K (mmol/L), Cl (mmol/L), P (mg/dL), N-acetyl glucosamine (NAG) (U/L) and pH values were measured. Then urea (mg/dL), creatinine (mg/dL), total protein (g/dL) and cystatin (mg/L) values were measured for the blood samples obtained from tail veins. RESULTS: The median NAG value for the control group (52.050 U/L) was similar to value for Group II (56.400 U/L), which received gentamicin and the garlic diet. However, the median NAG value for Group I (77.030 U/L), which received gentamicin without garlic supplementation, was determined to be statistically significantly higher (p = 0.010) than the value for the control group. In addition, the mean cystatin value for Group II (1.360 U/L) was found to be statistically significantly lower than the value for the Group I (2.240 U/L) (p = 0.015). CONCLUSIONS: In this study we showed the effect of 4% pulverized garlic supplemented diet for preventing nephrotoxicity induced by gentamicin in rats by using as parameters NAG in urine samples and cystatin C in serum samples.

Garlic supplemented diet attenuates gentamicin nephrotoxicity ın rats

Purpose To demonstrate the effect of a 4% pulverized garlic supplemented diet on the nephrotoxicity induced by gentamicin in rats. Materials and Methods Twenty four healthy male Wistar rats, weighing between 220 - 260grams, were divided into three groups. The rats were randomly assigned to either the gentamicin injection without garlic supplementation group (Group I, n = 8), gentamicin injection with garlic supplementation group (Group II, n = 8), and control group (Group III, n = 8). Urine from the rats was collected and the volume (mL), microalbumin (mg/L), creatinine (mg/dL), Na (mmol/L), K (mmol/L), Cl (mmol/L), P (mg/dL), N-acetyl glucosamine (NAG) (U/L) and pH values were measured. Then urea (mg/dL), creatinine (mg/dL), total protein (g/dL) and cystatin (mg/L) values were measured for the blood samples obtained from tail veins. Results The median NAG value for the control group (52.050 U/L) was similar to value for Group II (56.400 U/L), which received gentamicin and the garlic diet. However, the median NAG value for Group I (77.030 U/L), which received gentamicin without garlic supplementation, was determined to be statistically significantly higher (p = 0.010) than the value for the control group. In addition, the mean cystatin value for Group II (1.360 U/L) was found to be statistically significantly lower than the value for the Group I (2.240 U/L) (p = 0.015). Conclusions In this study we showed the effect of 4% pulverized garlic supplemented diet for preventing nephrotoxicity induced by gentamicin in rats by using as parameters NAG in urine samples and cystatin C in serum samples. .

Deficiency of cannabinoid receptor of type 2 worsens renal functional and structural abnormalities in streptozotocin-induced diabetic mice.

A functionally active endocannabinoid system is present within the kidney. The cannabinoid receptor type 2 (CB2) is expressed by both inflammatory cells and podocytes, and its activation has beneficial effects in experimental diabetic nephropathy. To further explore the role of CB2 in diabetic nephropathy, we studied renal functional and structural abnormalities in streptozotocin-induced diabetic CB2 knockout mice. In diabetic mice, deletion of the CB2 receptor albuminuria, the downregulation of podocin and nephrin, mesangial expansion, overexpression of extracellular matrix components, monocyte infiltration, and reduced renal function were all exacerbated. To investigate the relative contributions of podocytes and monocytes to the phenotype of diabetic knockout mice, bone marrow transplantation experiments were performed. The lack of CB2 on bone marrow-derived cells was shown to be important in driving the enhanced glomerular monocyte accrual found in diabetic knockout mice. Absence of CB2 on resident glomerular cells had a major role in worsening diabetic nephropathy, both functional and structural abnormalities, likely by enhanced MCP-1 and CB1 signaling. Studies in cultured podocytes demonstrated that CB2 expression is not altered by a high glucose milieu but is downregulated by mechanical stretch, mimicking glomerular capillary hypertension. Thus, CB2 deletion worsens diabetic nephropathy, independent of bone marrow-derived cells.

The smell of moulting: N-acetylglucosamino-1,5-lactone is a premoult biomarker and candidate component of the courtship pheromone in the urine of the blue crab, Callinectes sapidus.

Female blue crabs (Callinectes sapidus) in their pubertal moult stage release unidentified sex pheromone molecules in their urine, causing males to respond with courtship behaviours including a display called courtship stationary paddling and a form of precopulatory guarding called cradle carry. We hypothesized that pheromones are mixtures of molecules and are more concentrated in urine of pubertal premoult females compared with other moulting stages and thus that these molecules are biomarkers (i.e. metabolites that can be used as an indicator of some biological state or condition) of pubertal premoult females. We tested this hypothesis by combining bioassay-guided fractionation and biomarker targeting. To evaluate the molecular mass of the putative pheromone by bioassay-guided fractionation, we separated urine from pubertal premoult females and intermoult males by ultrafiltration into three molecular mass fractions. The <500 Da fraction and the 500-1000 Da fraction but not the >1000 Da fraction of female urine induced male courtship stationary paddling, but none of the fractions of male urine did. Thus, female urine contains molecules of <1000 Da that stimulate courtship behaviours in males. Biomarker targeting using nuclear magnetic resonance (NMR) spectral analysis of the 500-1000 Da fraction of urine from premoult and postmoult males and females revealed a premoult biomarker. Purification, nuclear magnetic resonance, mass spectrometry and high pressure liquid chromatography analysis of this premoult biomarker identified it as N-acetylglucosamino-1,5-lactone (NAGL) and showed that it is more abundant in urine of premoult females and males than in urine of either postmoult or juvenile females and males. NAGL has not been reported before as a natural product or as a molecule of the chitin metabolic pathway. Physiological and behavioural experiments demonstrated that blue crabs can detect NAGL through their olfactory pathway. Thus, we hypothesize that NAGL is a component of the sex pheromone and that it acts in conjunction with other yet unidentified components.

The protective effect of aminoguanidine on doxorubicin-induced nephropathy in rats.

Reactive oxygen species and cytokines have been implicated in the nephrotoxicity induced by doxorubicin. The goal of the present study was to determine protective effect of aminoguanidine on doxorubicin-induced nephrotoxicity in rats. Different groups of male Wistar rats received doxorubicin (67.75 mg/kg/i.p./2 days), aminoguanidine alone and aminoguanidine (200 and 400 mg/kg/i.p./30 days) prior to doxorubicin, respectively. Doxorubicin significantly increased serum creatinine (505%), blood urea nitrogen (333%), nitric oxide (406%), and plasma tumor necrosis factor-alpha (706%) as well as urinary albumin (452%) and N-acetyl-ß-D-glucosaminidase (415%) compared to control. Moreover, renal glutathione (334%), superoxide dismutase (283%), and catalase (513%) were significantly reduced accompanied with elevation in renal malondialdehyde compared to control. Pretreatment with aminoguanidine mitigated such changes in all mentioned parameters. Histopathological changes showed that doxorubicin-caused significant structural damages to kidneys that were reduced with aminoguanidine. Results indicate that reactive oxygen species and cytokines are involved in doxorubicin-induced nephrotoxicity, which can be reduced by aminoguanidine.

Early initiation of enzyme replacement therapy improves metabolic correction in the brain tissue of aspartylglycosaminuria mice.

Aspartylglycosaminuria (AGU) is a lysosomal storage disease caused by deficient activity of glycosylasparaginase (AGA), and characterized by motor and mental retardation. Enzyme replacement therapy (ERT) in adult AGU mice with AGA removes the accumulating substance aspartylglucosamine from and reverses pathology in many somatic tissues, but has only limited efficacy in the brain tissue of the animals. In the current work, ERT of AGU mice was initiated at the age of 1 week with three different dosage schedules of recombinant glycosylasparaginase. The animals received either 3.4 U of AGA/kg every second day for 2 weeks (Group 1), 1.7 U/kg every second day for 9 days followed by an enzyme injection once a week for 4 weeks (Group 2) or 17 U/kg at the age of 7 and 9 days (Group 3). In the Group 1 and Group 3 mice, ERT reduced the amount of aspartylglucosamine by 34 and 41% in the brain tissue, respectively. No therapeutic effect was observed in the brain tissue of Group 2 mice. As in the case of adult AGU mice, the AGA therapy was much more effective in the somatic tissues than in the brain tissue of the newborn AGU mice. The combined evidence demonstrates that a high dose ERT with AGA in newborn AGU mice is up to twofold more effective in reducing the amount of the accumulated storage material from the brain tissue than ERT in adult AGU animals, indicating the importance of early detection and treatment of the disease.

Crush syndrome after the Wenchuan earthquake: new experience with regional citrate anticoagulation continuous veno-venous hemofiltration.

PURPOSE: Acute renal failure (ARF) related to crush syndrome is usually treated with hemodialysis. Continuous veno-venous hemofiltration (CVVH) has seldom been adopted in this situation due to the main drawback of continuous anticoagulation. The purpose of this study was to evaluate the effectiveness and safety of regional citrate anticoagulation (RCA)-CVVH in two crush syndrome patients following the Wenchaun earthquake. METHODS: Two victims from the Wenchuan earthquake in Southwest China were admitted to our hospital on May 23, 2008, 11 days after their injury. The total entrapment time under the rubble was 5.5 and 22.5 hrs respectively. They remained oliguric on admission, in spite of vigorous treatment in the local hospital including aggressive fluid infusion, fasciotomy and intermittent hemodialysis. On admission, their serum myoglobin levels were 765 and 829 ng/mL, respectively. Further debridement and drainage were performed. RCA-CVVH was conducted; the citrate containing substitution fluid was infused in a pre-dilution manner at a rate of 4 l/h; calcium was infused through a separate access to the venous inlet of the double lumen catheter. The infusion rate was adjusted according to the serum ionized calcium and whole blood activated clotting time (WBACT). A low dose of low molecular weight heparin (LMWH) was infused at the rate of 150 approximately 300 U/h simultaneously for anticoagulation after anemia had been corrected and their wounds were stable. RCA-CVVH was substituted by conventional CVVH and LMWH anticoagulation when case 2 complicated with hypoxia. RESULTS: RCA-CVVH was well tolerated, hemodynamic status was stable, and no complications related with RCA-CVVH were noted. The body temperature and WBC decreased to normal range, while anemia and hypoalbuminia were corrected. The levels of serum myoglobin and creatine phosphokinase were also decreased to normal range. Their urine volume increased after 20 and 22 days of oliguria and the tubular function of the patients recovered well. Although the second case encountered acute cholecystitis and acute lung injury in the hospital, both the patients recuperated and neither of them underwent amputation. CONCLUSIONS: The present two crush patients have been successfully treated, but due to the limits of the small sample, it is difficult to generalize whether RCA-CVVH is safe enough for crush syndrome with a high risk of bleeding diathesis. Additional investigation with a larger number of patients is required. Fluid equilibrium, nutritional support, prevention of bleeding and infection are fundamental in this situation.

The influence of fasudil on the epithelial-mesenchymal transdifferentiation of renal tubular epithelial cells from diabetic rats.

To investigate the influence of fasudil on the epithelial-mesenchymal transdifferentiation of renal tubular epithelial cells from diabetic rats and explore the mechanisms of this effect. Wistar rats were randomly divided into the following three groups: control, diabetes and fasudil-treatment. All rats were sacrificed after three months of feeding with or without fasudil treatment. Pathological changes to the glomeruli and renal interstitium were studied using Periodic acid-Schiff's staining and Masson staining, respectively. Expression of ROCK1, alpha-SMA, E-cadherin and the distribution of beta-catenin in rat renal cortex were revealed by immunohistochemistry. Changes in the MYPT1 phosphorylation profile and alpha-SMA, E-cadherin and membrane beta-catenin expression were revealed by western blot. Changes in the levels of ROCK1, E-cadherin and total beta-catenin mRNA expression were analyzed by real-time PCR. Fasudil treatment notably attenuates renal interstitial fibrosis in diabetic rats. Compared to the control rats, diabetic rats showed elevated phosphorylation of MYPT1, increased expression of ROCK1 and alpha-SMA, decreased expression of E-cadherin and membrane beta-catenin, and increased expression of ROCK1 and total beta-catenin mRNA, decreased expression of E-cadherin mRNA. Fasudil treatment of diabetic rats resulted in attenuated MYPT1 phosphorylation, decreased ROCK1 and alpha-SMA expression, increased E-cadherin and membrane beta-catenin expression, and reduced ROCK1 and total beta-catenin mRNA expression, increased expression of E-cadherin mRNA. In conclusion, fasudil may reduce the epithelial-mesenchymal transdifferentiation and renal interstitial fibrosis in diabetic rats through a mechanism by which ROCK activity is inhibited, which further facilitates the recovery of the cell-cell adhesions among renal tubular epithelial cells and adhesion complex formation.

Bilateral pulvinar signal intensity decrease on T2-weighted images in patients with aspartylglucosaminuria.

BACKGROUND: Aspartylglucosaminuria (AGU) is an autosomal recessive lysosomal disease caused by deficiency of aspartylglucosaminidase. A thalamic T2 signal intensity decrease is associated with lysosomal diseases. PURPOSE: To investigate thalamic signal intensity in AGU by performing a retrospective review of brain magnetic resonance (MR) imaging studies of AGU patients. MATERIAL AND METHODS: A total of 25 MR examinations were available for 11 patients aged between 3 and 32 years (four patients underwent bone marrow transplantation). Of these, 13 examinations were performed after bone marrow transplantation. Five patients had from two to six examinations, and six patients had one examination each. In every patient, the diagnosis of AGU was confirmed by blood and urine tests. Eighteen examinations were performed with a 1.0T imager including dual spin-echo T2 and proton density (PD) axial and coronal images, and 10 examinations also included T1-weighted images. Seven examinations were performed with a 1.5T imager including turbo spin-echo axial and coronal T2-weighted images and axial fluid-attenuated inversion recovery (FLAIR) images; three examinations included T1-weighted three-dimensional magnetization-prepared rapid acquisition gradient-echo (3D MPRAGE) images. The signal intensity of the thalamus and pulvinar in every sequence was compared to that of the putamina. RESULTS: In AGU, thalamic alterations were first detectable on T2-weighted images (25 examinations in 11 patients) from the age of 3 years 6 months, showing decreased signal intensity in 21 of 24 examinations. T1-weighted images (13 examinations) showed slightly increased thalamic signal intensity in five out of seven examinations from the age of 7 years, and PD images (19 examinations) showed decreased signal intensity from the age of 16 years (three examinations). The pulvinar showed decreased signal intensity on spin-echo T2-weighted images for 14 of 18 examinations or on FLAIR sequences for seven of seven examinations from the age of 6 years and 6 months, both in patients with and without bone marrow transplantation, but no pulvinar alterations were observable on T1 and PD images. CONCLUSION: In AGU, the thalamus is affected. Pulvinar changes are visible only on T2-weighted images, and these may be the first changes reported in the group of lysosomal diseases.

Comparison of kidney injury molecule-1 and other nephrotoxicity biomarkers in urine and kidney following acute exposure to gentamicin, mercury, and chromium.

Sensitive biomarkers are needed to detect kidney injury at the earliest stages. The objective of this study was to determine whether the appearance of kidney injury molecule-1 (Kim-1) protein ectodomain in urine and kidney injury molecule-1/hepatitis A viral cellular receptor-1 (Kim-1/Havcr1) gene expression in kidney tissue may be more predictive of renal injury after exposure to nephrotoxicants when compared to traditionally used biomarkers. Male Sprague-Dawley rats were injected with a range of doses of gentamicin, mercury (Hg; HgCl2), or chromium (Cr; K2Cr2O7). The results showed that increases in urinary Kim-1 and kidney Kim-1/Havcr1 gene expression paralleled the degree of severity of renal histopathology and were detected at lower doses of nephrotoxicants when compared to blood urea nitrogen (BUN), serum creatinine, and urinary N-acetyl-beta-D-glucosaminidase (NAG). In a time course study, urinary Kim-1 was elevated within 24 h after exposure to gentamicin (100 mg/kg), Hg (0.25 mg/kg), or Cr (5 mg/kg) and remained elevated through 72 h. NAG responses were nephrotoxicant dependent with elevations occurring early (gentamicin), late (Cr), or no change (Hg). At 72 h, after treatment with any of the three nephrotoxicants, there was increased Kim-1 immunoreactivity and necrosis involving approximately 50% of the proximal tubules; however, only urinary Kim-1 was significantly increased, while BUN, serum creatinine, and NAG were not different from controls. In rats treated with the hepatotoxicant galactosamine (1.1 mg/kg), serum alanine aminotransferase was increased, but no increase in urinary Kim-1 was observed. Urinary Kim-1 and kidney Kim-1/Havcr1 expression appear to be sensitive and tissue-specific biomarkers that will improve detection of early acute kidney injury following exposure to nephrotoxic chemicals and drugs.

Renal safety and extrahepatic defluorination of sevoflurane in hepatic transplantations.

BACKGROUND: The main metabolic pathway for defluorination of sevoflurane in the liver produces inorganic fluoride (Fl). The metabolism and effect of sevoflurane on the kidney is not clear during anhepatic phase in liver transplantation. The goal of the present study was to investigate the metabolism and renal effect of sevoflurane by measuring plasma and urine inorganic fluoride, urinary N-acetyl-glucosaminidase (NAG), and plasma creatinine levels in patients undergoing liver transplantations. METHODS: After institutional approval and informed consent, we studied nine cases of orthotopic liver transplantation after anesthesia was induced with 5 mg . kg(-1) thiopental, 1 mug . kg(-1) fentanyl intravenously, the trachea was intubated after vecuronium bromide 0.1 mg . kg(-1). Anesthesia was maintained with sevoflurane (2%), O(2), and N(2)O at a total gas flow of 6 L . min(-1) using a semiclosed circle system with a sodalime canister. Blood and urine samples were obtained to measure plasma and urine fluoride concentrations and urinary NAG excretions before induction (P0), hourly during resection (P1, P2, P3), every 15 minutes during anhepatic phase (A1, A2, A3), hourly after reperfusion (neohepatic phase) (N1, N2, N3), and postoperative first hour (Po1). Preoperative (T0) and postoperative day 1 (T1), 3 (T3), 7 (T7) plasma blood urea nitrogen (BUN) and creatinine (Cr) levels were also recorded. RESULTS: Mean duration of surgery was 9:06 +/- 0:09 hours. Mean inorganic fluoride concentrations in plasma were in the range of 0.71 +/- 0.30 to 28.73 +/- 3.31 mumole . L(-1). In P3, N1, N2, N3, increases in plasma inorganic fluoride concentrations were significant (P < .05) and reached a peak value at Po1. The mean urine inorganic fluoride concentrations were 12.49 +/- 2.04 to 256.7 +/- 49.62 mumole . L(-1). In A2, A3, N1, N2, and N3, mean urine inorganic fluoride concentrations were significantly increased (P < .05) and the peak value was observed at Po1. Mean NAG concentrations in urine varied (5.6 +/- 1.6 IU . L(-1) to 12.5 +/- 1.14 IU . L(-1)) and peak level was observed at 30 minutes of the anhepatic phase (A2), which did not exceed the normal values for urine NAG levels (1.5 to 6.1 U . L(-1)). No impairment was observed in serum BUN and creatinine levels at any time. While there was only a slight increase in NAG during anhepatic phase, there was no change in plasma F1. CONCLUSIONS: Sevoflurane seemed to have minimal effect on kidney functions of BUN and Cr levels during liver transplantation. Although urine F1 and NAG levels increased during the anhepatic phase plasma F1, BUN, and Cr levels did not, suggesting that renal F1 production may occur in the absence of hepatic function. The renal effect of sevoflurane in chronic liver disease is controversial and must be investigated in further studies.

Sleep disturbances in aspartylglucosaminuria (AGU): a questionnaire study.

Sleep disturbances are common in many progressive metabolic encephalopathies. The possible presence of disturbed sleep-wake behaviour in the lysosomal storage disorder aspartylglucosaminuria, has not been previously studied, however. The sleep-wake behaviour of 81 patients with aspartylglucosaminuria (AGU, age 3-55 years, median 22 years; 42 female and 39 male) and 49 controls (age 2-57 years, median 18 years; 25 female and 24 male) was assessed through a postal survey. A slightly modified version of the validated Basic Nordic Sleep Questionnaire was used. Fifty-eight per cent of the AGU patients were reported to suffer daily from a sleep-related problem (controls 31%, p < 0.01). In AGU adults (age >17 years) and children (age < or =17 years), the corresponding figures were 52% and 61%, respectively (control children 22%, p < 0.05 and control adults 38%, p = 0.06). In AGU children, settling difficulties were reported to occur significantly more commonly than in control children. Children with AGU were also reported to snore more often than were the controls. Adults with this disorder were found to suffer from severely fragmented night-time sleep, which was experienced as highly distressing by the parents and other caregivers. A long night sleep period was reported to be common in the ageing AGU patients (AGU 9.5 +/- 1.7 vs controls 7.2 +/- 1.0 h, mean +/- SD, p < 0.001). Parents and caregivers also often complained about disturbing movements during sleep in AGU patients. In conclusion, both children and adults with aspartylglucosaminuria were reported to display several types of sleep disturbances significantly more commonly than healthy controls.

Extrahepatic metabolism and renal effects of sevoflurane in a case of liver transplantation.

In a case of liver transplantation, sevoflurane metabolism was studied to investigate if sevoflurane has an extrahepatic metabolism or possible nephrotoxicity in the presence of chronic liver disease. Plasma blood urea nitrogen (BUN) and creatinine and urine levels of N-acetyl glycosaminidase (NAG) and beta2 microglobulin were assessed intraoperatively and for 11 days postoperatively. We observed a close relation between urine NAG excretion and urine inorganic fluoride levels in the intraoperative period and early postoperative days. The NAG levels were greater than normal despite the peak serum inorganic fluoride concentration of 18.94 micromol/L. No impairment was observed in serum BUN or creatinine levels in these periods.

Involvement of de novo ceramide synthesis in radiocontrast-induced renal tubular cell injury.

We reported previously that various radiocontrast media cause apoptosis in porcine proximal tubular (LLC-PK(1)) cells, in which reduction in B-cell lymphoma (Bcl)-2 expression and caspase-3 activation are implicated. In the present study, we investigated a role for ceramide in radiocontrast media-induced apoptosis in renal tubular cells. LLC-PK(1) cells were exposed to radiocontrast media for 30 min, followed by incubation for 24 h in normal medium. Cell viability was assessed by 2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulfophenyl)-2H-tetrazolium monosodium salt assay, while apoptosis was determined by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling stain. Immunofluorescent stains were performed using antibodies against phosphorylated Akt (pAkt) and cAMP response element binding protein (CREB) (pCREB), and ceramide. The mRNA expression and protein content of Bcl-2 were determined by reverse transcriptase-polymerase chain reaction and enzyme immunoassay, respectively. In vivo model of contrast-induced renal injury was induced in mice with unilateral renal occlusion. The cell injury induced by the nonionic radiocontrast medium ioversol was reversed by inhibiting de novo ceramide synthesis with fumonisin B(1) (FB(1)) and L-cycloserine, but not by suppressing sphingomyelin breakdown with D609. FB(1) reversed ioversol-induced decrease in the immunoreactivities of pAkt and pCREB, reduction in Bcl-2 expression and caspase-3 activation. Like ioversol, C2 ceramide and the Akt inhibitor Src homology-6 induced apoptosis by reducing pAkt and pCREB-like immunoreactivities, lowering Bcl-2 expression and enhancing caspase-3 activity. Indeed, various radiocontrast media, excluding iodixanol which showed the least nephrotoxicity, enhanced ceramide-like immunoreactivity. The role for de novo ceramide synthesis was also shown in the in vivo model of radiocontrast nephropathy. We demonstrated here for the first time that the enhancement of de novo ceramide synthesis contributes to radiocontrast nephropathy.

Renoprotective effects of azelnidipine, a dihydropyridine-based calcium antagonist in advanced glycation end product (AGE)-injected rats.

Diabetic nephropathy is a leading cause of end-stage renal disease in industrialized countries. Although the molecular mechanisms for the development and progression of diabetic nephropathy are not fully understood, the formation and accumulation of advanced glycation end products (AGEs) have been considered to play a major role in the pathogenesis of diabetic nephropathy. Hypertension is also an independent risk factor for the progression of diabetic nephropathy. However, functional cross-talk between AGEs and blood pressure and their involvement in diabetic nephropathy remain to be elucidated. In this study, we examined the effects of oral administration of azelnidipine, a commercially available dihydropyridine-based calcium antagonist, on renal injury in AGE-treated rats. Administration of azelnidipine inhibited the increase of systolic and diastolic blood pressure levels and urinary N-acetyl-beta-D-glucosaminidase activity in exogenously AGE-injected rats. Furthermore, azelnidipine treatment also prevented glomerulosclerosis in AGE-treated rats. These results indicate that renal damage in AGE-injected rats could be mediated, at least in part, by the elevation of blood pressure. Our present study suggests that azelnidipine would represent a valuable drug for the treatment of diabetic nephropathy by blocking the deleterious effects of AGEs.

Reduction in head size in patients with aspartylglucosaminuria.

OBJECTIVE: To show that the head may shrink in adult patients with aspartylglucosaminuria (AGU), a neurodegenerative disease. METHOD: The head circumference (HC) of 40 adult patients (age at baseline 15 to 47) was measured twice with an interval of 10 years. Of these 40, 21 aged 15-47 and 19 young patients aged 5-14 as well as 40 healthy controls underwent lateral cephalometric radiography. RESULTS: During 10 years' follow-up, the HC of 26 (65%) had decreased by 1 to 4.5 cm (mean 1.7, P < 0.001). Evaluation of lateral skull radiographs revealed that patients aged 15 or more had significantly thicker skulls than did younger patients (P = 0.015). Mean intracranial length (glabella-opisthocranium) of the patients aged 15 or more was significantly shorter than in patients aged 14 years or less (P = 0.029). These measurements indicated that brain volume had decreased. CONCLUSIONS: Macrocephalia in childhood followed by reduced brain volume in adulthood is evident in patients with AGU and is reflected by a decrease in head size.

Olmesartan medoxomil, a newly developed angiotensin II type 1 receptor antagonist, protects against renal damage in advanced glycation end product (age)-injected rats.

Diabetic nephropathy is a leading cause of end-stage renal disease in industrialized countries. Although the molecular mechanisms for the development and progression of diabetic nephropathy are not fully understood, the formation of advanced glycation end products (AGEs) and activation of the renin-angiotensin system (RAS) have been considered to be the main factors participating in the pathogenesis of diabetic nephropathy. However, functional cross-talk between AGEs and the RAS remains to be elucidated. In this study, we examined the effects of oral administration of olmesartan medoxomil, a newly developed angiotensin II type 1 receptor antagonist, on renal damage in AGE-treated rats. Administration of olmesartan medoxomil significantly inhibited the increase of systolic and diastolic blood pressure levels and urinary N-acetyl-beta-D-glucosaminidase activity in exogenously AGE-injected rats. Furthermore, olmesartan medoxomil treatment also prevented glomerulosclerosis in AGE-treated rats. These results indicate that exogenous AGE treatment could induce renal damage via the activation of the RAS. Our study suggests that olmesartan medoxomil could be a valuable drug for the treatment of diabetic nephropathy by blocking the deleterious effects of AGEs.

Five-year follow-up of two siblings with aspartylglucosaminuria undergoing allogeneic stem-cell transplantation from unrelated donors.

BACKGROUND: Aspartylglucosaminuria is a rare, inherited lysosomal disease characterized by a slowly progressive mental retardation and coarse facial and body features. With the intent to provide the deficient enzyme aspartylglucosaminidase, allogeneic stem-cell transplantation (ASCT) has been attempted. Only a few cases of transplants have been reported. METHODS: Two siblings with aspartylglucosaminuria underwent allogeneic bone marrow transplants using unrelated human leukocyte antigen-A, -B, and DR identical donors at ages 10 years 5 months and 5 years 10 months, respectively. They were followed during 5 years with biochemical, neuroradiologic, neuropsychologic, and clinical investigations. RESULTS: During 5 years follow-up, no neuropsychologic or clinical deterioration was noted in the children. A stable expression of aspartylglucosaminidase was found during the whole follow-up period. The spinal fluid concentration of Tau-protein, a marker of neuronal and axonal degeneration and damage, peaked at approximately 12 months after bone-marrow transplantation and then declined to almost normal levels after 5 years. By magnetic resonance imaging (MRI), an improvement of myelination in the youngest sibling and an arrest of demyelination in the older one were observed. CONCLUSION: The importance of long-term follow-up of children after ASCT in this rare, very slowly progressive lysosomal disease must be emphasized. We report that none of the children had lost any capabilities since the transplantation; moreover, an improvement is shown in biochemical markers and MRI white-matter signals, suggesting a beneficial effect.

Startle epilepsy complicating aspartylglucosaminuria.

A 21-year-old right-handed man with definite diagnosis of aspartylglucosaminuria (AGU) presented with a 5-year history of progressive severe gait disturbance with frequent falls and generalized epileptic seizures triggered by unexpected stimuli. At one time, he was confined to a wheelchair because of the frequent falls. Electromyogram recording showed a large, excessive and not habituating motor startle response, with the classical and stereotyped order of muscle recruitment. During video-polygraphic recording, we recorded a reflex generalized tonic seizure triggered by a loud, unexpected acoustic stimulus. Brain magnetic resonance (MR) revealed no structural abnormality. A diagnosis of abnormal startle and startle epilepsy (SE) was made. The addition of clonazepam to valproate and phenobarbital led to a dramatic improvement in his abnormal startle and SE, and the patient was able to walk alone unaided. This report illustrates, for the first time, that abnormal startle and SE may occur in AGU and complicate its clinical picture. Recognition of this entity in AGU is important, as progressive gait disorder with frequent falls could be easily misinterpreted as an additional irreversible manifestation of the ongoing neurological deterioration characteristic of AGU.