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The chiral inversion kinetics of ibuprofen was evaluated after intraduodenal administration of racemic ibuprofen in conventional powder form and sustained-released granules compared with intravenous administration in rabbits. The AUC ratios of the S-(+) and R-(–) enantiomers remained almost constant values with time up to 2 h after administration of sustained-release formulation, while those after administration of the powder increased with time. R-(–) enantiomer to S-(–) enantiomer inversion ratios after intraduodenal administration of the powder form and the sustained-release form, and after intravenous injection were calculated to be 1.63, 1.94 and 1.19, respectively, indicating that pharmacological effects may depend on the absorption rate in rabbits.

Angiotensin II (ANG II) has been shown to play a role in the induction of glomerular injury. In the present study, we evaluated the effects of ANG II on mesangial cell apoptosis and the involved molecular mechanism. The effect of ANG II on apoptosis of mouse mesangial cells (MC) was evaluated by morphologic, DNA fragmentation and TUNEL assays. To evaluate the role of oxidative stress and involved mechanisms, we studied the effect of antioxidants, anti-TGF-β antibody, inhibitors of nitric oxide synthase and modulators of cytosolic calcium/heme oxygenase (HO) activity. In addition, we studied the effect of ANG II on the generation of reactive oxygen species (ROS) by MCs. ANG II promoted apoptosis of MCs in a dose dependent manner. This effect of ANG II was not only associated with ROS production, but also inhibited by antioxidants. Both Anti-TGF-β antibody and propranolol inhibited ANG II-induced ROS generation and apoptosis. BAPTA inhibited both ANG II- and TGF-β-induced apoptosis. On the other hand, thapsigargin stimulated MC apoptosis under basal as well as ANG II/TGF-β stimulated states. ANG II receptor types 1 and 2 antagonists attenuated the proapoptotic effect of ANG II. Hemin inhibited but zinc protoporphyrin enhanced the proapoptotic effect of ANG II. Propranolol increased HO activity; whereas pre-treatment with propranolol prevented ANG II-induced apoptosis. ANG II promotes MC apoptosis. This effect of ANG II is mediated through downstream signaling involving TGF-β, phospholipase D, and Ca2+, contributing to the activation of NADPH oxidase and generation of ROS. HO activity plays a modulatory role in ANG II-induced MC apoptosis.

The M-type phospholipase A2 receptor (PLA2R) is expressed in podocytes in human glomeruli. Group IB secretory phospholipase A2 (sPLA2 IB), which is one of the ligands of the PLA2R, is more highly expressed in chronic renal failure patients than in controls. However, the roles of the PLA2R and sPLA2 IB in the pathogenesis of glomerular diseases are unknown. In the present study, we found that more podocyte apoptosis occurs in the kidneys of patients with higher PLA2R and serum sPLA2 IB levels. In vitro, we demonstrated that human podocyte cells expressed the PLA2R in the cell membrane. After binding with the PLA2R, sPLA2 IB induced podocyte apoptosis in a time- and concentration-dependent manner. sPLA2 IB-induced podocyte PLA2R upregulation was not only associated with increased ERK1/2 and cPLA2α phosphorylation but also displayed enhanced apoptosis. In contrast, PLA2R-silenced human podocytes displayed attenuated apoptosis. sPLA2 IB enhanced podocyte arachidonic acid (AA) content in a dose-dependent manner. These data indicate that sPLA2 IB has the potential to induce human podocyte apoptosis via binding to the PLA2R. The sPLA2 IB-PLA2R interaction stimulated podocyte apoptosis through activating ERK1/2 and cPLA2α and through increasing the podocyte AA content.

Leader-follower formation control of Autonomous Underwater Vehicle is studied in this paper, and a three-dimensional formation control and obstacle avoidance method of multi-AUV is presented, which is based on back stepping control and biological inspired neural network model. The follower tracks the virtual AUV, during which the back stepping control method is lead up to realize three dimensional underwater formation control. To avoid obstacles and come through the obstacles' area, the biological inspired neural network model is used to transform the formation of the AUV. Simulation results show that the presented algorithm achieve the expected control effect, and verify the validity and the practicability of the algorithm.

Background: Catheter failure, especially catheter displacement and obstruction remain the major barriers for peritoneal dialysis. We have developed a new surgery technique of catheter fixation on the lower abdominal wall in the catheter planting to avert the catheter mechanical complications. Method: A retrospective study was performed on 93 patients; among them, 52 patients underwent the traditional method of surgery for catheter insertion and 41 patients received additional catheter fixation. Comparisons of complications including infection, leak, infusion pains, catheter displacement, and obstruction occurred during a follow-up period of 6 months, were made between the fixed and non-fixed groups. Results: Catheter fixation cost more time than the conventional operating procedure (94.2 w 14.6 min vs. 83 w 13.3 min, p = 0.043). Complications of infection, leak, and infusion pain that occurred in the fixed and unfixed groups are comparable. Catheter fixation reduced the complications of catheter displacement or obstruction to 0 episode in the fixed group, whereas those complications were encountered by 7 patients in the unfixed group (0/41 vs. 7/52, p = 0.022). All these 7 patients received re-exploration and catheter replacement with further catheter fixation. In the following time until now (ranging from 3 to 16 months), no catheter dysfunction was observed. Conclusions: These results suggest that catheter fixation is effective in preventing catheter displacement and obstruction in peritoneal dialysis. i 2014 S. Karger AG, Basel

Surfactant protein A (SP-A) contributes to the regulation of sepsis-induced acute lung injury. In a previous study, we demonstrated the expression and localization of SP-A in the kidneys. The present study evaluated the effect of SP-A on lipopolysaccharide (LPS)-induced tumor necrosis factor-a (TNF-α) expression and its underlying mechanisms in the human renal tubular epithelial (HK-2) cells.Indirect immunofluorescence assay was used to detect SP-A distribution and expression in HK-2 cells. HK-2 cells were treated with various concentrations of LPS (0, 0.1, 1, 2, 5, and 10 mg/L) for 8 hours and with 5 mg/L LPS for different times (0, 2, 4, 8, 16, and 24 hours) to determine the effects of LPS on SP-A and TNF-α expression. Then, HK-2 cells were transfected with SP-A siRNA to analyze nuclear factor κB (NF-κB) P65 and TNF-α expression of HK-2 cells after LPS-treatment.Indirect immunofluorescence assay revealed that SP-A is localized to the membrane and cytoplasm of HK-2 cells. Interestingly, SP-A1/SP-A2 and TNF-a expression were found to be significantly increased in HK-2 cells upon LPS treatment. Transfection of LPS-treated HK-2 cells with SP-A siRNA resulted in significant increases in the levels of NF-κB P65 protein and TNF-α mRNA and protein compared to those in non-transfected LPS-treated HK-2 cells.SP-A plays an important role in protecting cells against sepsis-induced acute kidney injury by inhibiting NF-κB activity to modulate LPS-induced increase in TNF-α expression.

Glomerular epithelial cells (GEC) have been demonstrated to undergo morphological alterations in human immunodeficiency virus (HIV)-associated focal glomerulosclerosis. In the present study, we evaluated the effect of HIV-1 gp120 envelope protein on the growth of cultured human (H) GEC. gp120 protein enhanced (P < 0.001) the proliferation of HGEC at lower concentrations. The mitogenic effect of gp120 protein on HGEC was further confirmed by enhanced accumulation of proliferating nuclear cell antigen (PCNA) by gp120 protein-treated cells, as compared with control cells. On the contrary, gp120 protein at higher concentrations suppressed (P < 0.001) the growth of HGEC. To evaluate the mechanism of gp120 protein-induced HGEC growth suppression, we examined the effect of gp120 protein on HGEC apoptosis. gp120 protein at higher concentrations promoted the apoptosis of HGEC. At higher concentrations, gp120 protein also enhanced DNA fragmentation of HGEC. Anti-gp120 antibody attenuated the proliferative as well as the apoptotic effects of gp120 protein on HGEC. Because protein kinase C as well as tyrosine kinase inhibitors partially inhibited gp120-induced proliferation, gp120 appears to be activating both the protein kinase C and tyrosine kinase pathways. In addition, gp120 protein at lower concentrations enhanced mRNA expression of c-fos and at higher concentrations promoted mRNA expression of c-jun. We conclude that gp120 has a bimodal effect on proliferation of HGEC. This effect may be mediated through the activation of early growth genes. J. Cell. Biochem. 76:61–70, 1999. © 1999 Wiley-Liss, Inc.

Patients with intravenous heroin addiction are prone to recurrent infections and at times these infections are fatal. We evaluated the effect of morphine on the apoptosis of Jurkat cells and freshly isolated human T lymphocytes. Morphine promoted apoptosis of both the Jurkat cells and the freshly isolated T lymphocytes in a dose-dependent manner. DAGO, a specific p receptor agonist, also promoted Jurkat cell apoptosis. DNA isolated from morphine-treated Jurkat cells and T lymphocytes also showed integer multiples of 200 base pairs. Superoxide dismutase (SOD) enhanced lymphocyte apoptosis; whereas catalase attenuated the morphine-induced apoptosis of Jurkat cells as well as of T lymphocytes. Morphine-treated Jurkat cells also showed a decreased expression of bcl-2 and an enhanced expression of bax. In addition, morphine-treated Jurkat cells showed activation of caspase-3. These results indicate that morphine-induced T lymphocyte apoptosis may be mediated through the generation of reactive oxygen species. The change in ratio of bax and bcl-2 seems to tilt the balance toward apoptosis, leading to the activation of caspase-3. This study provides further support for the hypothesis that morphine may be directly compromising immune function by enhancing apoptosis of T lymphocytes in patients with heroin addiction. J. Leukoc. Biol. 66: 650–658; 1999.

In this study, we evaluated the location of non-specific proteinase inhibitors and their receptor in experimental glomerular and interstitial fibrosis. The alpha macroglobulins alpha-2-macroglobulin (alpha 2M) and alpha-1-inhibitor 3 (alpha 1I3) are proteinase inhibitors, including metalloproteinases and serine proteases. Using immunohistochemistry, we detected alpha 1I3 in the glomerular mesangium in control rats. In acute and chronic fibrosis, the alpha 1I3 protein expression was dramatically increased throughout the glomerulus and at sites of increased extracellular matrix deposition in the interstitium, The presence of alpha 1I3 in normal and nephrotic kidneys was confirmed by Western blotting. Under chemically reducing conditions, we found that, in contrast to native alpha 1I3, kidney-derived alpha 1I3 has reacted upon by proteinases, thereby revealing a functional role for this macroglobulin under normal and pathological conditions. Double staining revealed that high amounts of glomerular alpha 1I3 were present in sclerotic lesions, alpha 2M was absent in glomeruli and interstitium from control rats, but present in small amounts in glomerular mesangial areas of acute nephrotic rats. alpha 2M was also present in significant amounts in glomeruli from rats with chronic fibrosis. The receptor mediating the uptake of proteinase inhibitor-proteinase complexes, the low-density-lipoprotein-related protein! alpha-2-macroglobulin receptor, was found in the glomerular mesangium and tubulo-interstitium from control rats. Significant increments in receptor expression were found in glomeruli and interstitium of rats with chronic fibrosis, with a preferential localization in fibrotic areas. Interstitial staining for low-density-lipoprotein-related protein/alpha-2-macroglobulin receptor was attributed to fibroblasts, since double staining ruled out dendritic cells and macrophages. In conclusion, these studies demonstrate the intrarenal presence of plasma-derived proteinase inhibitors together with their receptors. These findings may point to a novel mechanism for renal fibrosis wherein matrix-degrading proteinases are inhibited, resulting in renal fibrosis.

We assessed whether levels of renal reactive oxygen species (ROS) and antioxidant enzymes are perturbed in rats following unilateral ureteral obstruction (UUO). The mechanism of catalase perturbation was investigated using proximal tubule suspensions following stimulation with transforming growth factor (TGF)-beta and interleukin (IL)-1 and in a proximal tubular cell line (OKC) subjected to cyclic mechanical stretch, which mimics the early hydrodynamic derangement after UUO. Levels of catalase and copperzinc superoxide dismutase (Cu,Zn-SOD) mRNA from 96-h UUO rats showed a 5.5-fold (P < 0.001) and 5.0-fold (P < 0.001) decrease, respectively, compared with the contralateral unobstructed kidney (CUK). Levels of superoxide anion and hydrogen peroxide showed a significant 1.8-fold (P < 0.0001) and 14.0-fold (P < 0.0001) increase, respectively, in 96-h UUO kidney slice cultures. In situ hybridization and immunohistochemistry showed Cu,Zn-SOD and catalase mRNA and protein transcription expressed in proximal tubules of UUO and CUK specimens. Catalase mRNA levels were markedly downregulated following a 1-h exposure of isolated proximal tubules to TGF-beta (0.1–10 ng) and IL-1 (1–5 ng), in comparison to control proximal tubular suspensions. OKC subjected to cyclic mechanical stretch for 1–24 h had marked decrements in catalase mRNA levels, compared with unstretched cells at the same time point. These results indicate that a primary downregulation of proximal tubular Cu,Zn-SOD and catalase expression develops in the proximal tubules of UUO with consequent increments in cortical oxidant levels. These findings suggest that either an early mechanical disturbance produced by UUO or local tubular generation of cytokines can reduce tubular catalase expression. The downregulation of catalase mRNA expression, together with increased oxidant stress in the rat renal cortex post-UUO, may amplify the proinflammatory state of experimental hydronephrosis culminating in tubulointerstitial injury and fibrosis.

Background: Renal tubular cell apoptosis is a key mechanism of contrast-induced acute kidney injury. It has been reported that endoplasmic reticulum (ER) stress is the underlying mechanism of high osmolar contrast-induced renal tubular cell apoptosis. Whether ER stress is involved in low osmolar contrast-induced renal tubular cell injury remains unclear. In the present study, the roles of ER stress in iopromide-induced (a low osmolar contrast) renal tubular cell apoptosis and the effects of N-acetylcysteine (NAC) on ER stress were investigated. Methods: NRK-52E cells were exposed to different concentrations of iopromide [50, 100 and 150 mg iodine (I)/ml] for 4 h. In a separate experiment, NRK-52E cells were exposed to iopromide (100 mg I/ml, 4 h) with or without NAC (10 mmol/l). NAC was added 1 h before incubation with iopromide. Apoptosis was determined by Hoechst staining and flow cytometry. The intracellular formation of reactive oxygen species (ROS) was detected by confocal microscopy with fluorescent probe CM-H2DCFDA. The expression of glucose-regulated protein 78 (GRP78) and CAAT/enhancer-binding protein homologous protein (CHOP) was determined by Western blot. Results: Iopromide induced NRK-52E cell apoptosis in a concentration-dependent manner. The intracellular ROS production increased significantly following iopromide exposure in the NRK-52E cells. Significantly increased expressions of GRP78 and CHOP were observed in the NRK-52E cells exposed to iopromide for 4 h; NAC attenuated iopromide-induced NRK-52E cell apoptosis by inhibiting the overproduction of intracellular ROS and subsequently suppressing the overexpression of GRP78 and CHOP. Conclusion: ROS-mediated ER stress is involved in contrast-induced renal tubular cell apoptosis.

Intravascular large B-cell lymphoma (IVLBCL) is a rare type of non- Hodgkin lymphoma characterized by a disseminated intravascular proliferation of tumor cells in the lumina of small vessels. Although the kidney is one of the target organs of IVLBCL, lymphoma cells that localize only in glomeruli are extremely rare. We report a 55-year-old Chinese patient diagnosed as glomerular-limited IVLBCL by percutaneous renal biopsy. The patient was referred to our institution for further examination of mild proteinuria and anemia without lymphoma symptoms. He had daily urinary excretion of 0.65 g proteins with normal renal function. Percutaneous renal biopsy showed that lymphoid cell accumulation was encircled within the glomerular capillary lumina only in certain glomeruli, resulting in marked obstruction of capillary structure. However, almost all of the peritubular capillary and tubulointerstitium were intact. Immunohistochemical analysis confirmed the diagnosis of intravascular large B-cell lymphoma. Extensive systemic examinations showed no other organ involvement. With these characteristic changes, glomerularlimited IVLBCL were considered as an exceptional renal manifestation of intravascular lymphoma diagnosised by percutaneous renal biopsy.

Background/Aims: The mechanism underlying angiotensin II (AngII)-promoted podocyte apoptosis has not been established. IQ domain GTPase-activating protein 1 (IQGAP1) is a scaffolding protein of the mitogen-activated protein kinases (MAPK) signaling pathway, and plays a significant role in apoptosis. The present study evaluates the role of IQGAP1 in AngII-induced podocyte apoptosis. Methods: We randomly assigned 36 male Wistar rats to a normal saline-infused group, an AngII-infused group, or a normal control group, and measured podocyte apoptosis by the terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) assay and transmission electron microscopic analysis. In addition, we exposed differentiated mouse podocytes to AngII and then assessed apoptosis by flow cytometry and Hoechst-33258 staining. Expression of IQGAP1 was measured by Western blotting, real-time PCR and immunofluorescence assay in vivo and in vitro. IQGAP1 siRNA and MAPK pathway inhibitors were further introduced to investigate the role of IQGAP1 and MAPK signaling in the process. Coimmunoprecipitation was used to evaluate the interaction between ERK1/2 and IQGAP1. Results: AngII promoted podocyte apoptosis in vivo and in vitro. IQGAP1 had a linear distribution along the capillary loops of glomeruli in vivo, and was in the cellular membrane and cytoplasm of cultured podocytes. AngII stimulated IQGAP1 expression and increased phosphorylation of P38, JNK, and ERK1/2. Knockdown of IQGAP1 with siRNA prevented AngII-induced apoptosis of podocytes and reduced AngII-induced phosphorylation of ERK1/2, but not that of P38, JNK. This was accompanied by a reduced interaction between ERK1/2 and IQGAP1. Conclusion: IQGAP1 contributes to AngII-induced apoptosis of podocytes by interacting with the ERK1/2 signaling protein.

Autophagy is a cellular pathway involved in protein and organelle degradation. It is relevant to many types of cellular homeostasis and human diseases. High level of glucose is known to inflict podocyte injury, but little is reported about the relationship between high concentrations of glucose and autophagy in these cells. The present study demonstrates that high glucose promotes autophagy in podocytes. Rapamycin further enhances this effect, but 3-methyadenine inhibits it. The proautophagic effect of high glucose manifested in the form of enhanced podocyte expression of LC3-2 and beclin-1; interestingly, antioxidants such as NAC were found to inhibit high glucose-induced autophagy. High glucose induced the generation of ROS by podocytes in a time-dependent manner. High glucose also enhanced podocyte expression of MnSOD and catalase. These findings indicate that high glucose-induced autophagy is mediated through podocyte ROS generation.

The precise mechanisms underlying radiocontrast nephropathy (RCN) are not well understood. Intracellular Ca(2+) overload is considered to be a key factor in RCN. The Na(+)/Ca(2+) exchanger (NCX) system is one of the main pathways of intracellular Ca(2+) overload. We investigated whether intracellular Ca(2+) overload via the NCX system was involved in contrast-induced renal tubular cytotoxicity.NRK-52E cells were exposed to ioversol (100 mg iodine/ml) for 4 h. KB-R7943 (inhibitor of reverse mode of NCX, 4 × 10(-5), 4 × 10(-6)M) was added 1 h before incubation with ioversol. Cell viability and permeability were determined by 3-(4,5-dimethyldiazol-2-yl)-2,5-diphenyl tetrazolium bromide and lactate dehydrogenase assay. Apoptosis was determined by flow cytometry. Intracellular Ca(2+) concentration ([Ca(2+)](i)] and reactive oxygen species (ROS) were detected by confocal microscopy. The expression of NCX1 mRNA and caspase-3 protein was evaluated by reverse transcription-polymerase chain reaction and Western blot, respectively.Ioversol exposure induced significantly increased lactate dehydrogenase release and decreased 3-(4,5-dimethyldiazol-2-yl)-2,5-diphenyl tetrazolium bromide conversion in NRK-52E cells. Significantly increased apoptosis and caspase-3 protein expression were observed in the NRK-52E cells exposed to ioversol for 4 h. Ioversol treatment induced a significant increase in [Ca(2+)](i) and intracellular ROS. KB-R7943 dose-dependently and significantly suppressed the increase in [Ca(2+)](i), intracellular ROS and caspase-3 overexpression induced by ioversol and attenuated the contrast-induced NRK-52E cell apoptosis. No significant changes in NCX1 mRNA expression were observed following contrast exposure.Intracellular Ca(2+) overload via the reverse mode of NCX, followed by ROS overproduction and caspase-3 overexpression played an important role in the contrast-induced renal tubular cytotoxicity. The reverse mode of the NCX inhibitor KB-R7943 attenuated contrast-induced renal tubular cytotoxicity.

Through arranging and analysing the relevant literature, the article systematically introduces the United Kingdom ongoing extracurricular games in terms of the guiding ideology ,contribution , organization and management of the competition as well as formats, and then presents four suggestions for the operation of Sunshine Sports Program in China: expands the range of benefits of Sunshine Sports Program especially for students with disabilities, forms a functional system of the linkage at school, community and family level, gradually establishes the "government guides, social groups leads" Sun Sports Program administration pattern through socialization and market-oriented operation, positively develops and innovates game system and formats with local characteristics. Index Terms - Extracurricular Games in United Kingdom, primary and secondary school of China, Sunshine Sports Program

Left ventricular hypertrophy (LVH) and systolic dysfunction would predict the mortality of patients undergoing maintenance hemodialysis. The cause of LVH is usually related to the increase of total peripheral vascular resistance and overloading volume. The presence of residual diuresis enables greater control of the volume. This study evaluated the effects of residual renal function (RRF) on the left ventricle and analyzed the related factors involved in hemodialysis patients.A total of 59 hemodialysis patients were classified into two groups. The patients in the RRF (RRF+) group had a urine volume greater than 200 mL/24 h, and the patients in the non-RRF (RRF-) group had a urine volume less than 200 mL/24 h. B-type natriuretic peptide (BNP), blood total homocysteine (tHcy), and blood biochemical indexes were determined for the patients in both groups. Echocardiography and Doppler tests were performed to determine the cardiac indexes.LVH and systolic dysfunction in the RRF+ group were less severe than those in the RRF- group. The concentration of tHcy and BNP in patients with RRF was decreased in comparison with those without RRF. The concentration of tHcy and BNP was positively correlated with the residual diuresis.There were distinct ventricular geometric patterns and different functional performances between RRF+ and RRF- groups. The presence of residual diuresis had a beneficial effect on the left ventricular function in hemodialysis patients.

Introduction Podocytes play an important role in the pathogenesis and progression of glomerulosclerosis. Various elements of the renin-angiotensin-aldosterone system can induce podocyte apoptosis. However, little is known about the direct effects of renin on podocytes. Methods The authors used the mouse podocyte cell line to investigate the apoptotic effects mediated by the renin receptor. The authors used fluorescent staining and reverse-transcriptase polymerase chain reaction to detect renin receptor expression. Podocytes were incubated with renin for variable time periods. Apoptosis was evaluated by cell nucleus staining, and caspase-3, p38 and phospho-p38 mitogen-activated protein kinase (MAPK) were measured. Results The authors found that both renin receptor mRNA and protein were expressed in the mouse podocyte cell line. Exposure of podocytes to renin induced podocyte apoptosis in a time- and dose-dependent manner, which was accompanied by upregulation of active caspase-3 and increased expression of p38 MAPK. p38 MAPK phosphorylation and apoptosis were inhibited when the cells were pretreated with p38 MAPK inhibitor. Transfection of renin receptor small interfering RNA attenuated the above changes induced by renin. Furthermore, the effects of renin were not altered by inhibition of angiotensin II-mediated effects using enalaprilat or losartan. Conclusion The authors conclude that the effects of renin are mediated through the activation of rennin receptor and are independent of angiotensin II generation.

In the present study, we evaluated the effect of inhibition of renin activity (aliskiren) on the progression of renal lesions in two different mouse models (Vpr and Tg26) of human immunodeficiency virus (HIV)-associated nephropathy (HIVAN). In protocol A, Vpr mice were fed either water (C-VprA) or doxycycline [Doxy (D-VprA)] in their drinking water for 6 wk. In protocols B and C, Vpr mice received either normal saline (C-VprB/C), Doxy + normal saline (D-VprB/C), or Doxy + aliskiren (AD-VprB/C) for 6 wk ( protocol B) or 12 wk ( protocol C). In protocols D and E, Vpr mice were fed Doxy for 6 wk followed by kidney biopsy. Subsequently, half of the mice were administered either normal saline (D-VprD/E) or aliskiren (AD-VprD/E) for 4 wk ( protocol D) or 8 ( protocol E) wk. All D-VprA mice showed renal lesions in the form of focal segmental glomerular sclerosis and dilatation of tubules. In protocols B and C, aliskiren diminished both progression of renal lesions and proteinuria. In protocol C, aliskiren also diminished ( P < 0.01) the rise in blood urea. In all groups, Doxy-treated mice displayed increased serum ANG I levels (the product of plasma renin activity); on the other hand, all aliskiren-treated mice displayed diminished serum ANG I levels. Renal tissues of D-VprC displayed increased ANG II content; however, aliskiren attenuated renal tissue ANG II production in AD-VprC. In protocol D, AD-VprD showed a 24.2% increase in the number of sclerosed glomeruli compared with 139.2% increase in sclerosed glomeruli in D-VprD ( P < 0.01) from their baseline. The attenuating effect of aliskiren on the progression of renal lesions continued in AD-VprE. Aliskiren also diminished blood pressure, proteinuria, and progression of renal lesions in Tg26 mice. These findings indicate that inhibition of renin activity has a potential to slow down the progression of HIVAN.

Summary Surfactant protein D (SP-D), a member of the C-type lectin (collectin) protein family, plays a critical role in innate host defence against various microbial pathogens and in the modulation of inflammatory responses in the lung. However, little is known about its expression and biological function in the kidney. In this work, we studied SP-D expression in human kidney and cultured human renal proximal tubular epithelial cells (HK-2), and examined the effect of SP-D on proinflammatory cytokine production after lipopolysaccharide (LPS) stimulus. We observed the expression of both SP-D mRNA and protein in human kidney and in-vitro HK-2 cells by immunohistochemistry, Western blot analysis, reverse transcription–polymerase chain reaction (RT–PCR) and real-time PCR. To explore the potential role of SP-D in the pathogenesis of tubulointerstitial fibrosis in kidney infection, we examined the production of monocyte chemoattractant protein-1 (MCP-1) in HK-2 cells after LPS treatment. Results showed that the level of MCP-1 in the conditioned medium increased significantly when HK-2 cells were cultured with LPS (>0·1 µg/ml) for 8 h. Of interest, LPS treatment inhibited SP-D expression in HK-2 cells. Furthermore, over-expression of SP-D reduced significantly the LPS-induced expression of MCP-1 in transfected cells. These findings suggest that SP-D in the kidney functions as an anti-inflammatory factor in renal tubular epithelial cells and may modulate tubulointerstitial fibrosis in kidney.

Macrophage infiltration into the glomerular mesangium is a prominent feature of various glomerulopathies. Recent evidence suggests that infiltrating macrophages may play a role in propagating initial glomerular injury to the development of glomerulosclerosis via transforming growth factor-beta (TGF-beta)-stimulating matrix accumulation. Rats with the acute puromycin aminonucleoside (PA) nephrosis exhibit an elevated gene expression of glomerular TGF-beta 1; however, the cellular origin of this upregulation is unknown. Using polymerase chain reaction (PCR), we detected that the TGF-beta 1 isoform is expressed in glomerular macrophages isolated from experimental rats made hypercholesterolemic by either diet or by induction of PA nephrosis. Peritoneal macrophages from nephrotic or dietary-hypercholesterolemic animals also exhibited a significant increment in the expression of TGF-beta 1 mRNA on Northern analysis, in contrast to similar cells obtained from normal control rats. PCR analysis of glomerular RNA also detected the expression of the TGF-beta 2 mRNA isoform. TGF-beta 2 mRNA expression was not observed in isolated glomerular macrophages from either glomeruli of PA-nephrotic rats or from glomeruli of animals with dietary hypercholesterolemia. Expression of the TGF-beta 3 mRNA isoform was only observed by PCR in J774 A.1 cells. Thus the as a cellular source for the enhanced expression of TGF-beta 1 during the acute nephrotic phase of our toxic, progressive glomerulopathy model and within several days of inducing only hypercholesterolemia by dietary means.

The title compound, C(10)H(12)O(2)S, crystallizes with four mol-ecules in the asymmetric unit. The main conformational difference between these mol-ecules is the orientation of the acetyl groups with respect to the ring. Whereas one acetyl group is only slightly twisted with respect to the thio-phene ring [C-C-C-O torsion angles = 165.7 (4), -164.6 (4), 164.3 (4) and -163.6 (4)°], the other acetyl group is markly twisted out of the ring plane [C-C-C-O torsion angles = -61.2 (6), 61.3 (7), -59.7 (7) and 59.9 (6)°]. In the crystal, mol-ecules are linked by weak C-H⋯O inter-actions into infinite chains along the c axis.

Background. Several studies in patients with primary aldosteronism (PA) have suggested that aldosterone (ALD) is directly contributing to albuminuria. However, there are limited data pertaining to the direct role of ALD in in vivo models in regard to the induction of renal injury and the involved mechanisms. In the present study, we established a high-dose ALD-infused rat model to evaluate urinary albumin excretion rate (UAER) and podocyte damage. Moreover, we studied the effect of eplerenone (EPL), telmisartan (TEL) and amlodipine (AML) on ALD-induced renal structural and functional changes. Methods. Immunohistochemical and real-time PCR analyses, and TUNEL assays were performed to evaluate nephrin expression and podocyte injury. Results. ALD-receiving rats (ARR) showed a progressive increase in BP, UAER and proteinuria when compared with control rats (CR). Conversely, BP was significantly reduced in ALD + EPL (A/ERR)-, ALD + AML (A/ARR)- and ALD + TEL (A/TRR)-treated rats. However, UAER and proteinuria were decreased only in A/ERR and A/TRR, but not in A/ARR. Only EPL administration provided protection against ALD-induced podocyte apoptosis. Renal tissue of ARR revealed enhanced expression of nephrin protein and mRNA. This effect of ALD was inhibited by EPL, but not by TEL or AML. Conclusions. ALD induces direct glomerular injury independent of its haemodynamic effects; this effect of ALD is, at least in part, mediated through activation of the mineralocorticoid receptor.

An efficiency optimization vector control scheme based on back propagation (BP) is presented in this paper. The controller is designed to generate d-axes currents command and q-axes currents command simultaneously. In order to achieve a robust BP efficiency optimization vector control from variation of motor parameters, an online learning algorithm is employed. Results of experiments are provided to demonstrate the effectiveness of the proposed method.

A power transformer operating in electric network is supplied by voltage source. When analyzing leakage flux and magnetic forces of the power transformer applied to windings, the field-circuit coupled 3D finite element method is needed because of the drawbacks of magnetic dipole model and 2D finite element method. The models were used for simulating and analyzing leakage flux and magnetic forces data sets. It is the base for further studying on magnetic flux leakage and magnetic forces inspection.

Hypercholesterolemia aggravates experimental progressive glomerular injury. Evidence suggests the infiltrating glomerular macrophage (M phi) is a potential effector mechanism for the noxious effects of hypercholesterolemia. Because transforming growth factor (TGF)-beta 1 is secreted by activated M phi s and also stimulates fibronectin production by glomerular cells, we evaluated the kinetics of gene expression for these moieties in glomeruli isolated from nephrotic rats at 3, 7, 11, and 42 days after the delivery of puromycin aminonucleoside (PA). We also assessed whether cholesterol feeding, which raises the glomerular M phi number, alters the glomerular mRNA levels for TGF-beta 1 and fibronectin. Glomerular mRNA levels for TGF-beta 1 and fibronectin in nephrotic rats exhibited a biphasic temporal pattern, decreasing significantly below control at 3 and 7 days after PA but increasing significantly at 11 and 42 days after PA. The upregulated gene expression for TGF-beta 1 and fibronectin at 11 days after PA temporally corresponded to the phase of mesangial M phi infiltration in this model. Cholesterol feeding to both normal and nephrotic rats significantly increased glomerular TGF-beta 1 and fibronectin mRNA levels at 11 days after PA. Immunohistochemical labeling for M phi s and intracellular TGF-beta 1 demonstrated both mesangial and cortical interstitial localization with the TGF-beta1-positive cells possessing M phi nuclear morphology. These findings identify a novel interaction between hypercholesterolemia, augmented glomerular M phi accumulation, and upregulated glomerular TGF-beta 1 and fibronectin gene expression. These perturbations within the acutely injured glomerulus constitute an early pathobiological determinant for the later development of mesangial matrix expansion and glomerulosclerosis.

Background To investigate the effect of oxidized low density lipoprotein receptor-1 (LOX-1) on tubular epithelial-mesenchymal transition (TEMT) induced by oxidized low-density lipoprotein (ox-LDL) and its mechanism. Methods NRK-52E cells were incubated with ox-LDL (0, 25, 50, and 100 μg/ml) for 24 hours or pre-treated with the chemical inhibitor of the LOX-1 receptor polyinosinic acid (poly I) and carrageenan or the antioxidant N-acetyl-L-cysteine (NAC), the cells were then exposed to 50 μg/ml of ox-LDL.The expression of LOX-I, E-cadherin, α-smooth muscle actin (α-SMA) and reactive oxygen species (ROS) were analyzed by real-time PCR, western blotting analysis, immunofluorescence and confocal laser scanning microscopy. Results Ox-LDL increased the expression of LOX-1 mRNA and protein in a dose-dependent manner from 0 to 100 μg/ml (P < 0.05). Following the increase in the LOX-1 protein level, the lipid intake, ROS generation and α-SMA expression increased; however, the E-cadherin level decreased. The pre-treatment with poly I or carrageenan or NAC significantly inhibited the LOX-1 expression, α-SMA expression, the lipid intake and ROS generation and reversed decrease of E-cadherin expression induced by ox-LDL. Meanwhile, the ROS generation were associated with a increase in the LOX-1 expression. The α-SMA expression was positively correlated with the ROS generation and LOX-1 expression, and the E-cadherin expression was negatively correlated with the ROS generation and LOX-1 expression. Conclusions LOX-1 and ROS may play a important role in epithelial-mesenchymal transition of NRK52E induced by OX-LDL.

A significant proportion of renal allografts fail within several months or years after transplantation, primarily because of chronic rejection. The etiology and pathophysiology of this condition remain unclear. We studied the renal function, morphology, and immunohistology, in parallel, among F344-to-Lewis allografts (n = 23) and isografts (n = 13) over the course of 24 weeks. Only an initial 10-day course of CsA (5 mg/kg/day) was given to both groups to prevent acute rejection. Hypertension did not develop, although awake systolic blood pressure was significantly higher in allografts at the end of the study. Significant differences in urine albumin excretion (UalbV) between isografts and allografts were evident as early as 4 weeks after engraftment but rose dramatically by 20 weeks (3.3 +/- 0.7 vs. 21.2 +/- 3.7 mg/day, respectively, P < .001). This pattern continued until the conclusion of the study (5.0 +/- 1.1 vs. 53.5 +/- 7.6 mg/day, P < .001). Serum creatinine values were only significantly elevated in allografts at 16 weeks, which temporally corresponded to the dramatic increase in UalbV. However, renal blood flow and glomerular filtration rate, measured by paraaminohippurate and inulin clearances, respectively, were significantly lower in allografted organs, at 24 weeks. The frequency of glomerulosclerosis lesions was significantly increased in allografted kidneys at 24 weeks and correlated with UalbV values. Glomerular localization of mononuclear leukocyte subsets were equivalent between allografts and isografts; however, the numbers of interstitial macrophages, CD8+, and pan-T-cells were all significantly greater in allografts at 24 weeks. The infiltration of significantly greater numbers of macrophages and lymphocytes into the tubulointerstitium of the allograft group suggests a mononuclear leukocyte effector cell mediation of the progressive glomerular abnormalities in this model of chronic renal allograft rejection in the rat.

Human immunodeficiency virus (HIV)-1-associated nephropathy (HIVAN) is characterized by proliferation of glomerular and tubular epithelial cells. We studied the role of epithelial mesenchymal transdifferentiation (EMT) in the development of HIVAN phenotype. Renal cortical sections from six FVB/N (control) and six Tg26 (HIVAN) mice were immunolabeled for PCNA, α-smooth muscle actin (α-SMA), fibroblast-specific protein-1 (FSP1), CD3, and F4/80. Since periglomerular cells (PGCs) and peritubular cells (PTCs) did not show any labeling for CD3 and F4/80 but showed labeling for α-SMA or FSP1, it appears that these were myofibroblasts that migrated from either glomerular or tubular sites, respectively. Occurrence of EMT was also supported by diminished expression of E-cadherin by renal epithelial cells in Tg26 mice. Interestingly, Tg26 mice also showed enhanced renal tissue expression of ZEB2; henceforth, it appears that transcription of molecules required for maintenance of de novo renal epithelial cell phenotype was suppressed. To evaluate the role of ANG II, Tg26 mice in groups of three were administered either normal saline or telmisartan (an AT1receptor blocker) for 2 wk, followed by evaluation for renal cell EMT. Renal cortical section of Tg26 mice showed a sevenfold increase ( P < 0.001) in parietal epithelial cell (PEC)-PGC and a threefold increase ( P < 0.01) in tubular cell (TC)-PTC proliferation (PCNA-positive cells). Similarly, both PECs-PGCs and TCs-PTCs in Tg26 mice showed enhanced expression of α-SMA and FSP1. Both PECs and podocytes contributed to the glomerular proliferative phenotype, but the contribution of PECs was much greater. Telmisartan-receiving Tg26 mice (TRM) showed attenuated number of proliferating PECs-PGCs and TCs-PTCs compared with saline-receiving Tg26 mice (SRM). Similarly, TRM showed diminished expression of α-SMA and FSP1 by both PECs-PGCs and TCs-PTCs compared with SRM. We conclude that EMT contributes to the manifestation of the proliferative phenotype in HIVAN mice.

Vasopressin (AVP) induces the rapid fusion of water channel-containing vesicles with the luminal membrane of its target cell. We have carried out a quantitative study of the F-actin content of toad bladder epithelial cells, using the rhodamine phalloidin binding assay. As early as 1 min after AVP stimulation, there is a significant 15% reduction of cellular F-actin, which remains reduced by 20-30% for the duration of action of AVP. Comparable reductions were seen following 8-bromoadenosine 3',5'-cyclic monophosphate, 1-desamino-8-D-arginine vasopressin, and forskolin. F-actin content rose to and then exceeded that of control bladders after AVP washout. Inhibition of prostaglandin synthesis enhanced both water flow and the decrease of F-actin. In the living cell, stabilization of F-actin with NBD-phallacidin selectively inhibited water flow. In view of the rapidity of the response, we conclude that AVP shifts the equilibrium between F-actin and G-actin monomers, and this depolymerization may be required for vesicle fusion.

Background: Podocytes play a critical role in the pathogenesis of glomerulosclerosis. Increasing evidence suggests that aldosterone (ALD) is involved in the initiation and progression of glomerular damage. It is, however, unknown whether there is a direct injurious effect of ALD on podocytes. Therefore, in the present study, we evaluated the effect of ALD on podocyte apoptosis and studied the role of phosphatidylinositol 3-kinase/Akt (PI3-K/Akt) and p38 mitogen-activated protein kinase (p38MAPK) signaling pathways in this process. Methods: Podocytes were incubated in media containing either buffer or increasing concentrations of ALD (10–9∼10–5M) for variable time periods. The cells were also treated with either wortmannin (inhibitor of PI3-K, 100 nM), SB202190 (SB20, inhibitor of p38MAPK, 10 μM) or buffer. All treatments were performed with or without ALD (10–7M) for 24 h. At the end of the incubation period, apoptosis was evaluated by cell nucleus staining and flow cytometric analyses. Activation of PI3-K/Akt and p38MAPK phosphorylation of cultured rat podocytes was evaluated by performing Akt kinase assay and Western blot, respectively. Results: Apoptosis of cultured rat podocytes was induced by ALD in a dose- and time-dependent manner. ALD inhibited the activity of PI3-K/Akt and increased the activation of p38MAPK. PI3-K/Akt activity was further inhibited by the addition of wortmannin to the cells in the presence of ALD. This was accompanied by a significant increase in apoptosis. ALD-induced p38MAPK phosphorylation and apoptosis were inhibited when the cells were pretreated with SB20. Furthermore, treatment with spironolactone not only attenuated the proapoptotic effect of ALD, but also significantly reversed its effects on PI3-K/Akt and p38MAPK signaling pathways. Conclusion: ALD induces apoptosis in rat podocytes through inhibition of PI3-K/Akt and stimulation of p38 MAPK signaling pathways. Spironolactone attenuates ALD-induced podocyte apoptosis, thereby positioning this compound as a potential promising target of intervention in human renal damage.

The effect of absorption rate on the pharmacokinetics of ibuprofen enantiomers was investigated in 12 healthy Han Chinese male volunteers following oral administration of immediate-release (IR) and sustained-release (SR) preparations containing racemic ibuprofen (rac-ibuprofen). The area under the curve of the plasma concentration-time curve (AUC; (mean ± s.d.) values for rac-ibuprofen were 192.90 ± 43.47 for the SR preparation and 195.90 ± 31.69 μg h mL−1 for the IR preparation. AUC values for the enantiomers after administration of the SR formulation were 55.38 ± 17.79 and 92.51 ± 30.68 μg h mL−1 for R- and S-ibuprofen, respectively, and were 65.94 ± 20.06 and 100.81 ± 32.28 μg h mL−1 for R- and S-ibuprofen after administration of the IR preparation. These values did not differ significantly. Cmax values were significantly decreased with the SR preparation: 25.11 ± 5.71, 12.24 ± 3.79 and 12.38 ± 3.55 μg mL−1 for rac-, R-, and S-ibuprofen, respectively, after administration of the SR preparation, vs 46.21 ± 8.20, 20.82 ± 5.90 and 23.46 ± 7.30 μg mL−1 for rac-, R-, and S-ibuprofen, respectively, after administration of the IR preparation. Mean residence time was significantly increased: 7.01 ± 1.29, 5.52 ± 1.25 and 7.04 ± 1.30 h for rac-, R-, and S-ibuprofen, respectively, after administration of the SR preparation vs 4.34 ± 0.89, 3.43 ± 0.64 and 4.51 ± 0.79 h for rac-, R-, and S-ibuprofen, respectively, after administration of the IR preparation. AUC values for S-ibuprofen were significantly larger than those for R-ibuprofen in both preparations, indicating unidirectional chiral inversion. The S/R ratio of serum concentrations of enantiomers was 1.78-fold higher at 6 h after administration of the SR preparation compared with the IR preparation (P < 0.01). These results indicate that ibuprofen undergoes pre-systemic chiral inversion in parallel with a systemic process and that the clinical effects of rac-ibuprofen in humans depend on the absorption rate.

Isoetes sinensis Palmer (Isoetaceae) is a critically endangered fern that is a marsh plant (that is an aquatic or amphibious plant) in China. To evaluate damage or influence of lead (Pb) on cell ultrastructure in I. sinensis, we used 2000mg·L-1 Pb(NO3)2 solution to treat I. sinensis for 35d, and used transmission electron microscope (TEM) to observe the cell ultrastructure of leaf blades and roots of the plant. Our results indicated that Pb induced distinct changes of the organelles including chloroplast, mitochondria, nucleolus and vacuole. The level of damage organ was lower leaf > upper leaf > root The typical performance of the damages caused by lead shown that part of the nucleolus cracked; the cristae dilated, matrix vacuolized and membrane structure blurred in mitochondria; the vacuole cracked; grana lamella decreased, stroma lamella loosed, starch grains decreased, and membrane structure was disrupted in chloroplasts; Pb deposits were present on cell wall. The damages to chloroplasts and mitochondria were relatively severe, while damage to the nucleus was relatively lighter. The damage to the cell ultrastructure of leaf blades with direct contact with Pb was more severe than that without direct contact with Pb.

Background Radiocontrast nephropathy (RCN) is a major complication after radiographic examination. The precise mechanisms underlying RCN are not well understood. Renal tubular cell apoptosis is a feature of RCN, but hyperosmolality cannot fully explain the cytotoxicity of contrast media. There is accumulating evidence that reactive oxygen species (ROS) is involved in the pathophysiology of RCN, whereas the correlation between oxidative stress and contrast media-induced cell apoptosis is not clear. We hypothesized that ROS mediated apoptosis in renal tubular cells exposed to contrast media. Irbesartan, a selective AT1 receptor antagonist has been demonstrated an antioxidative effect. The present study was designed to determine whether irbesartan attenuated the contrast media-induced renal tubular cell apoptosis. Methods NRK-52E cells were exposed to increasing concentration (25, 50, 100, 150 mg iodine mL−1, 335, 384, 420, 521 mOsm kg−1) of ioversol (a non-ionic contrast media) for 1 h or incubated in ioversol (100 mg iodine mL−1, 420 mOsm kg−1) for 15 min, 30 min, 60 min, 120 min, 240 min, respectively. Mannitol with the same osmolality as ioversol (420 mOsm kg−1) also treated NRK-52E cells for 1 h. In separate experiment, irbesartan (0.01, 0.1, 1 mmol L−1) was added 1 h before incubation with ioversol (100 mg iodine mL−1, 420 mOsm kg−1) for 1 h. Apoptosis was determined by Hoechst staining and flow cytometry with annexinV-FITC and propidium iodide. The intracellular formation of ROS was detected by confocal microscopy with fluorescent probe CM-H2DCFDA. Bax and bcl-2 mRNA expression were determined by reverse transcription–polymerase chain reaction (RT–PCR). Results Ioversol induced NRK-52E cells apoptosis in a concentration- and time-dependent manner. The intracellular ROS generation was greatly increased following ioversol stimulus. Furthermore, ioversol induced a decrease in the expression for bcl-2 mRNA and an increase for bax mRNA. Irbesartan attenuated the ioversol-induced apoptosis in NRK-52E cells in a dose-dependent manner, in which the protective effect of irbesartan was dependent on decreasing intracellular ROS formation. In addition, irbesartan reversed the ioversol-induced increase in bax mRNA and decrease in bcl-2 mRNA. Conclusion Ioversol induced NRK-52E cells apoptosis in a concentration- and time-dependant manner via an increase in oxidative stress and subsequent to the increase in mRNA expression for bax and reduction in bcl-2 mRNA. Irbesartan attenuated the ioversol-induced apoptosis in NRK-52E cells by reducing oxidative stress and reversing the enhancement of bax mRNA and the reduction in bcl-2 mRNA.

Background/Aims: Oxidative stress has been considered to be a common pathogenetic factor of diabetic nephropathy. But the reason why renal cells are susceptible to oxidative injury in diabetes is not clear. Vitamin C plays a central role in the antioxidant defense system and exists in two major forms. The charged form, ascorbate, is taken up into cells via sodium-dependent facilitated transport. The uncharged form, dehydroascorbate, enters cells via glucose transporter and is then converted back to ascorbate within these cells. Because dehydroascorbate and glucose compete for glucose transporters, hyperglycemia will exclude vitamin C from the cell and resulted in a decreased antioxidant capacity in some cell type that is dehydroascorbate dependent. As such, we hypothesized that some renal cells were dehydroascorbate dependent and the susceptibility of renal cells to glucose-induced injury was mediated by hyperglycemic exclusion of dehydroascorbate uptake through competing for glucose transporter. The aims of the present study were to determine whether tubular epithelial cell was dehydroascorbate dependent and the effect of dehydroascorbate on the production of reactive oxygen species in cells incubated by high glucose. Methods: Tubular epithelial cell was cultured in RPMI-1640 medium containing 10% newborn calf serum. Intracellular ascorbate and dehydroascorbate contents were measured with vitamin C assay system. The intracellular formation of reactive oxygen species was detected with the fluorescent probe CM-H2DCFDA by using confocal microscopy. Results: Ascorbate entry into the cells was not significantly different from background noise. In contrast, we observed a significant increase in the uptake of dehydroascorbate in tubular cell. At a dehydroascorbate concentration of 1 mM, increasing concentrations of glucose competitively inhibited dehydroascorbate entry into the cells such that the accumulation of dehydroascorbate was smaller than half maximal at about 22 mM glucose. Cytochalasin B, a kind of hexose transporter inhibitor, inhibited dehydroascorbate entry into the cells. At a glucose concentration of 25 mM, increasing concentrations of dehydroascorbate reduced reactive oxygen species generation in a dose-dependent manner when dehydroascorbate concentration was smaller than 4 mM. However, the inhibitory effect was not observed at 8 mM of dehydroascorbate. Conclusions: Tubular epithelial cells are dehydroascorbate dependent. Vitamin C exclusion from tubular epithelial cells through competition of glucose and dehydroascorbate for common transport mechanism in diabetes will deprive the cells of antioxidant ability and could lead to reactive oxygen species accumulation.

Glomerular epithelial cell (GEC) injury has been considered to play an important role in puromycin aminonucleoside (PAN)-induced nephrosis. We studied the effect of PAN on rat as well as human GEC apoptosis. Morphogic evaluation of GEC apoptosis and necrosis was carried out by staining with H-33342 and propidium iodide. GEC apoptosis was further confirmed by DNA fragmentation assay (by both agarose gel electrophoresis and end-labeling). To determine the dose- and time-response effect of PAN, GECs were treated with variable concentrations of PAN (10 to 500 μg/ml) for variable time periods (6 to 48 h). To determine the role of gene synthesis, we studied the effect of actinomycin D (a transcriptional inhibitor) on PAN-induced GEC apoptosis.To determine the role of free radicals, we evaluated the effect of superoxide dismutase (SOD), dimethylthiourea (DMTU), and catalase on PAN-induced GEC apoptosis. PAN induced GEC apoptosis in a dose- and time-dependent manner. PAN at a high concentration (PAN, 100 μg/ml) also induced a moderate degree of GEC necrosis. In DNA fragmentation assays PAN-treated GECs showed the classic ladder pattern. PAN-induced GEC apoptosis was partly attenuated with free radical scavengers, such as SOD, DMTU, and catalase. In addition, actinomycin D attenuated PAN-induced GEC apoptosis. PAN induces GEC apoptosis, which may be mediated through the generation of reactive oxygen species.

Kidney aging has been recognized as a chronic process of compromised renal function and structural changes in the tubulointerstitium and glomerulus. Cell senescence is associated with alterations in cell structure and function, including expression of cytokines and structural and regulatory components of extracellular matrix proteins. In this investigation, we tested the hypothesis that senescent renal cells may accumulate in vivo with advancing age. We also evaluated the expression of transforming growth factor (TGF)-beta1 and p21WAF1/CIP1 in aging kidneys. Sprague-Dawley rats at the ages of 3, 12, and 24 months were used for this study. Renal tissues were processed for morphometric and senescence analysis. Expression of TGF-beta1 and p21WAF1/CIP1 was evaluated by Northern or Western blot analysis and immunohistochemistry. Substantial tubulointerstitial injury occurred at the age of 12 months, but significant glomerular structure alteration was observed at the age of 24 months. Tubular cells developed senescence, which was detected by beta-galactosidase staining. This staining increased in frequency and intensity with age. Renal cortices showed a significant increase in the mRNA expression for TGF-beta1 and protein level for p21WAF1/CIP1. The enhanced expression of TGF-beta1 and p21WAF1/CIP1 was localized in the tubulointersititial cells. These data suggest that tubular cells undergo senescence and express increased TGF-beta1 and p21WAF1/CIP1 with advancing age. These age-related cellular and molecular alterations may play an important role in the initiation and/or progression of tubulointerstitial fibrosis and glomerulosclerosis in aging.

Early cellular and molecular derangements have been evaluated as potential pivotal factors for the late development of interstitial fibrosis after experimental hydronephrosis. In this study, we delineated the kinetics of renal cortical macrophage infiltration as well as the cortical expression of transforming growth factor-beta 1 (TGF-beta 1) and monocyte chemoattractant peptide-1 (MCP-1) at 12, 48, and 96 h after unilateral ureteral obstruction (UUO). Interstitial macrophage number in the obstructed kidney versus the contralateral unobstructed kidney (CUK) significantly increased by 12 (11.1 +/- 0.9 vs. 4.5 +/- 0.6), 48 (27.5 +/- 0.9 vs. 4.0 +/- 0.8), and 96 h (71.4 +/- 4.6 vs. 3.2 +/- 0.4) after UUO. MCP-1 mRNA was detected from 12 to 96 h in the obstructed kidney but was absent in the CUK specimens at all time points. Apical tubular MCP-1 expression, on immunolabeling, was present from 12 through 96 h after UUO in the obstructed kidney but not the CUK specimen. On Northern analysis, there were highly significant 2.6-, 5.8-, and 7.0-fold increments in renal cortical TGF-beta 1 mRNA levels at 12, 48, and 96 h, respectively, in the obstructed kidney versus the CUK specimen. Intracellular TGF-beta 1, on immunolabeling, was detected only in the obstructed kidneys of UUO rats at all three time points and was confined to peritubular cells of the renal interstitium. A significant (P < 0.005) correlation (r = 0.95) between interstitial macrophage number and cortical TGF-beta 1 mRNA levels was noted.(ABSTRACT TRUNCATED AT 250 WORDS)

Vasopressin (AVP) promotes the fusion of vesicles containing water channels with the apical membrane of receptor cells in the amphibian bladder and mammalian kidney. Fusion is accompanied by depolymerization of the actin cytoskeleton. In this review, we present the evidence for actin depolymerization by AVP in the whole cell, and the application of confocal microscopy and immunogold electron microscopy in localizing depolymerization to the apical region of the receptor cell.

In this paper we report the structural, electrical and optical properties of epitaxial Ba(Sb x Sn1−x )O3 (x = 0–0.30) (BSSO) films grown on SrTiO3(0 0 1) substrates by the pulsed laser deposition method. The investigation reveals that the transport and optical characteristics of BSSO films depend very sensitively on the Sb-doping content. Temperature-dependent resistivity measurements show that at low Sb contents (x = 0.03, 0.07) the metal–semiconductor transition occurs at 150 K and 80 K, respectively, and the semiconductor behaviour appears in high doped (x = 0.15, 0.30) films. The transmittance decreases significantly from about 80% to nearly zero in the visible region and the optical band gap shifts from 3.48 to 4.0 eV with increasing Sb content in the films. The lowest room-temperature resistivity of 2.43 mΩ cm with carrier density and mobility of 1.65 × 1021 cm−3 and 1.75 cm2 V−1 s−1 was obtained in the films with doping at x = 0.07. By employing them as bottom electrodes we have fabricated transparent Pb(Zr0.52Ti0.48)O3 ferroelectric capacitors showing square polarization–electric field hysteresis loops, indicating that these perovskite-type BSSO films at low doping can be potentially used in transparent devices especially based on all-perovskite heterostructures.

We tested whether the deleterious effects of hypercholesterolemia, in a progressive glomerular disease model, may be mediated by infiltrating renal macrophages. A single sublethal dose of whole body X-irradiation (XI) delivered to rats with acute puromycin aminonucleoside (PA) nephrosis fed a high-cholesterol (HC) diet resulted in significantly greater inulin and p-aminohippurate (PAH) clearances at 11 days after PA without any alterations in circulating lipid levels, in contrast to nonirradiated HC-fed nephrotic controls. This functional protection was associated with significant declines in both glomerular and cortical interstitial macrophage number. Over the course of this 16-wk model, HC-fed PA rats had significantly less albuminuria as well as significantly fewer glomerulosclerosis (GS) lesions and less mesangial matrix expansion at the end of the study despite an equivalent degree of sustained hypercholesterolemia. This data suggests that reducing the infiltrating glomerular and cortical interstitial macrophage burden with XI during acute PA nephrosis, unaccompanied by any hypolipidemic effect, produces not only early salutary effects on renal function but also a significant amelioration of the progressive glomerulopathic features of this model. This is consistent with the hypothesis that the infiltrating renal macrophage, in large part, directly mediates the adverse effects of hypercholesterolemia in this model.

Cytochalasins are widely used to determine the role of actin in cellular processes. Their actions include capping of the barbed end of actin filaments as well as dimer formation, nucleation, and polymerization. We determined the effect of cytochalasin D (CD) on F-actin in the toad urinary bladder, an epithelium in which vasopressin depolymerizes F-actin. At a low concentration (0.25 microM), CD depolymerized F-actin in the unstimulated cell; at higher concentrations, there was a progressive reduction of depolymerization until actual polymerization was seen. Vasopressin plus CD produced no greater depolymerization than vasopressin alone, suggesting that CD and vasopressin act to a large extent on the same pool of F-actin. CD plus vasopressin also enhanced the fusion rate of aggrephores compared with vasopressin alone, indicating that intact actin filaments retard aggrephore fusion. Despite the increase in aggrephore fusion, water flow was not enhanced by CD, confirming previous reports that intact actin filaments are required for water channel emergence or stabilization in the apical membrane. Vasopressin plus 1 microM CD produced a striking increase in microvillar length, direct evidence of the polymerizing action of CD in the cell.

The pharmacokinetics of [6]-gingerol were investigated in rats with acute renal failure induced by bilateral nephrectomy, or those with acute hepatic failure induced by a single oral administration of carbon tetrachloride (CCl4), to clarify the contribution of the kidney and liver to the elimination process of [6]-gingerol. After bolus intravenous administration, a plasma concentration-time curve of [6]-gingerol was illustrated by a two-compartment open model. There was no significant difference in either the plasma concentration-time curve or any pharmacokinetic parameters between the control and nephrectomized rats. It is suggested, therefore, that renal excretion does not contribute at all to the disappearance of [6]-gingerol from plasma in rats. In contrast, hepatic intoxication with CCl4 elevated the plasma concentration of [6]-gingerol at the terminal phase. Its elimination half-life increased significantly, from 8.5 to 11.0 min, in CCl4-intoxicated rats. The extent of [6]-gingerol bound to serum protein was more than 90% and was affected very slightly by the CCl4-intoxication. These aspects indicate that [6]-gingerol is eliminated partly by the liver.

A high-performance liquid chromatographic method to determine [6]-gingerol, a pungent constituent of ginger, in rat plasma was developed and a pharmacokinetic study was performed in rats. Quantitative analysis with high reproducibility was achieved for [6]-gingerol over the concentration range of 0.2-40 micrograms/ml. After bolus intravenous administration at a dose of 3 mg/kg, the plasma concentration-time curve was described by a two-compartment open model. [6]-Gingerol was rapidly cleared from plasma with a terminal half-life of 7.23 min and a total body clearance of 16.8 ml/min/kg. Serum protein binding of [6]-gingerol was 92.4%.