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Presents a letter to the editor regarding herb-associated carcinogenicity and chronic renal failure in Asian patients with kidney cancer and hypertension, previously published in the journal "Kidney International."

Tubular epithelial-myofibroblast transdifferentiation in progressive tubulointerstitial fibrosis in 5/6 nephrectomized rats. Background. Tubulointerstitial fibrosis is the final common pathway to end-stage renal failure. The present study investigated the potential role of tubular epithelial cells (TEC) in progressive fibrosis in the rat remnant kidney model. Methods . Rats underwent 5/6 nephrectomy or a sham operation (control), and groups of six animals were killed at weeks 1, 3, 5, 9, 13, 17 and 21. Results. Immunohistochemistry staining and in situ hybridization at week 3 after nephrectomy demonstrated de novo expression of alpha-smooth muscle actin (α-SMA)–a marker of smooth muscle cells and myofibroblasts–by TEC that was invariably associated with disruption of the tubular basement membrane (TBM). This phenotypic evidence of tubular epithelial-myofibroblast transdifferentiation was supported by ultrastructural studies identifying the presence of characteristic actin microfilaments and dense bodies within TEC with a transformed morphology. In the late stage of this apparent tubular epithelial-myofibroblast transdifferentiation, TEC lost apical-basal polarity and tight junctions, became elongated, detached from the TBM, separated from neighboring cells and appeared to migrate into the peritubular interstitium through the damaged basement membrane. Indeed, focal peritubular accumulation of α-SMA+ myofibroblasts and local tubulointerstitial fibrosis was closely associated with α-SMA+ tubules, suggesting a tubular epithelial origin for some of these cells. Quantitative analysis found a significant correlation between the number of α-SMA+ TEC and the accumulation of interstitial α-SMA+ myofibroblasts and the severity of tubulointerstitial fibrosis (both P < 0.001). Conclusions. This study provides phenotypic and morphological evidence to support the hypothesis that TEC are... [ABSTRACT FROM AUTHOR]

Diabetic nephropathy is characterized by excessive deposition of extracellular matrix protein and disruption of the glomerular filtration barrier. Matrix metalloproteinases (MMPs) affect the breakdown and turnover of extracellular matrix protein, suggesting that altered expression of MMPs may contribute to diabetic nephropathy. Here we used an MMP-9 gene knockout mouse model, with in vitro experiments and clinical samples, to determine the possible role of MMP-9 in diabetic nephropathy. After 6 months of streptozotocin-induced diabetes, mice developed markedly increased albuminuria, glomerular and kidney hypertrophy, and thickening of the glomerular basement membrane. Gelatin zymographic analysis and western blotting showed that there was enhanced MMP-9 protein production and activity in the glomeruli. However, MMP-9 knockout in diabetic mice significantly attenuated these nephropathy changes. In cultured podocytes, various cytokines related to diabetic nephropathy including TGF-β1, TNF-α, and VEGF stimulated MMP-9 secretion. Overexpression of endogenous MMP-9 induced podocyte dedifferentiation. MMP-9 also interrupted podocyte cell integrity, promoted podocyte monolayer permeability to albumin, and extracellular matrix protein synthesis. In diabetic patients, the upregulation of urinary MMP-9 concentrations occurred earlier than the onset of microalbuminuria. Thus, MMP-9 seems to play a role in the development of diabetic nephropathy. [ABSTRACT FROM AUTHOR]

Previous studies have shown that nonsteroidal anti-inflammatory drug (NSAID) use might be associated with a lower risk of developing cancer in the general population. Patients on dialysis have increased risk for cancer, but there are no studies to determine the relationship between NSAID use and cancer risk in these patients. To identify any association between NSAID use and cancer risk in patients with end-stage renal disease on dialysis, we used Taiwan's National Health Insurance database to conduct a nationwide population-based, propensity score-matched cohort study. All cancers between groups were compared by Cox proportional hazards models. Compared to nonuse of NSAIDs, the use of non-COX-2-selective inhibitors (hazard ratio 0.81, 95% confidence interval 0.67-0.97) or COX-2-selective inhibitors (0.78, 0.62-0.98) was associated with a lower risk of developing cancer. NSAID use reduced the risk of respiratory (0.39, 0.19-0.79), breast (0.41, 0.19-0.89), kidney (0.58, 0.38-0.88), digestive tract (0.64, 0.49-0.85), and bladder cancers (0.73, 0.55-0.96). NSAID use, however, significantly increased risk for upper gastrointestinal bleeding (odds ratio, 1.15, 1.07-1.23) but not adverse cardiac or cerebrovascular events. Thus, NSAID use was associated with a lower risk of developing cancer in chronic dialysis patients; however, they should still be used with caution due to the side effects of gastrointestinal bleeding. [ABSTRACT FROM AUTHOR]

Background. It remains uncertain whether the hemodynamic parameters are important determinants of left ventricular mass (LVM) in normotensive chronic hemodialysis (NTHD) patients, as has been found in their hypertensive counterparts. Methods. Forty NTHD patients (mean age, 53.7 ± 14.4 years; male/female, 18/22) without the requirement of antihypertensive drugs for at least six months were studied. Controls were 41 hypertensive hemodialysis patients (HTHD) and 46 normotensive subjects with normal renal function (NTNR). The influence of anthropometrics, cardiovascular structure and function, and volume status on LVM (by two-dimensional echocardiography) was analyzed by steps of multiple linear regression. Results. As compared with the NTNR and NTHD group, the HTHD group had obvious pressure and volume/flow overload, and greater LV wall thickness, chamber size and mass. In contrast, NTHD subjects had similar blood pressure, large artery function, LV chamber size and stroke volume as the NTNR subjects. However, the NTHD patients still had greater wall thickness and LVM, along with greater cardiac output, lower total peripheral resistance and lower end-systolic meridional stress to volume ratio (ESSV) than the NTNR group. LVM in the NTHD group was significantly positively related to averaged systolic blood pressure (SBPavg), body surface area, extracellular fluid (ECF), carotid intima-media thickness (IMT), aortic pulse wave velocity (PWV), and negatively related to ESSV and Kt/V. The independent significant noncardiac structural determinants of LVM in NTHD subjects were ESSV, SBPavg, PWV and SV (model r² = 0.617, P < 0.001). Conclusions. The NTHD patients, without significant pressure and volume overload, still had increased LVM that was partially explained by the persistent flow overload and subclinical LV dysfunction. [ABSTRACT FROM AUTHOR]

Intravenous ascorbic acid as an adjuvant therapy for recombinant erythropoietin in hemodialysis patients with hyperferritinemia. Background. Inadequate iron mobilization and defective iron utilization may cause recombinant erythropoietin (rEPO) hyporesponsiveness in hemodialysis (HD) patients with iron overload. We have demonstrated that intravenous ascorbic acid (IVAA), but not intravenous iron medication, can effectively circumvent the functional iron-deficient erythropoiesis associated with iron overload in HD patients. However, it is uncertain whether all HD patients with hyperferritinemia will consistently respond to IVAA and which index may indicate functional iron deficiency in the special entity. Therefore, a prospective study was conducted to establish the guidelines for IVAA adjuvant therapy. Methods. Sixty-five HD patients with serum ferritin levels of more than 500 μg/liter were recruited and divided into the control (N = 19) and IVAA (N = 46) groups. IVAA patients with a hematocrit (Hct) of less than 30% received 300 mg of ascorbic acid three times per week for eight weeks. Controls had a Hct of more than 30% and did not receive the adjuvant therapy. Red blood cell and reticulocyte counts, iron metabolism indices, erythrocyte zinc protoporphyrin (E-ZPP), and the concentrations of plasma ascorbate and oxalate were examined before and following the therapy. Results. Thirteen patients (four controls and nine IVAA patients) withdrew by the end of the study. Eighteen patients had a dramatic response to IVAA with a significant increase in their hemoglobin and reticulocyte index and a concomitant 24% reduction in rEPO dose after eight weeks. This paralleled a significant rise in serum iron and transferrin saturation (TS) and a fall in E-ZPP and serum ferritin (baselines vs. 8 weeks, serum iron 68 ± 37 vs. 124 ± 64 μg/dl, TS 27 ± 10 vs. 48 ± 19%, E-ZPP 123 ± 44 vs. 70 ± 13 μmol/mol heme, and serum ferritin 816... [ABSTRACT FROM AUTHOR]

Erythropoietin hyporesponsiveness: From iron deficiency to iron overload. Iron deficiency is the most frequently encountered cause of suboptimal response to recombinant human erythropoietin (rHuEPO). Carefully assessing iron status is of paramount importance in chronic renal failure patients prior to or during rHuEPO therapy. Because there is great need for iron in the EPO-stimulated erythroid progenitors, it is essential that serum ferritin and transferrin saturation levels should be maintained over 300 μg/liter and 30%, respectively. Investigators have shown that oral iron is unlikely to keep pace with the iron demand for an optimal rHuEPO response in uremics. Therefore, patients with iron deficiency will always require intravenous iron therapy. The early and prompt iron supplementation can lead to reductions in rHuEPO dose and hence cost. After the iron deficiency has been corrected or excluded, we must remember all of the possible causes of hyporespon-siveness in every rHuEPO-treated patient. As dose requirements vary, it is not clear which dose of rHuEPO causes this hyporesponsiveness. However, if the patient with iron repletion does not respond well after the induction period, the major causes blunting the response to rHuEPO should be investigated. Most factors are reversible and remediable, except resistant anemia associated with hemoglobinopathy or bone marrow fibrosis, which requires a further increase in the rHuEPO dose. By means of early detection and correction of the possible causes, the goal of increasing therapeutic efficacy can be achieved. Iron overload may lead to an enhanced risk for infection, cardiovascular complication, and cancer. Over-treatment with iron should be avoided in dialysis patients, despite the fact that the safe upper limit of serum ferritin to avoid iron overload is not clearly defined. On the other hand, functional iron deficiency may develop even when serum ferritin levels are increased. Controversy remains as to whether intravenous iron therapy can overcome this form of hyporesponsiveness in iron-overloaded patients. Moreover, a treatment option of iron supplementation is not warranted in these patients, as the potential hazards of iron overload will be worsened. We demonstrated that the mean hematocrit significantly increased from 25.1 ± 0.9% to 31 ± 1.2% after eight weeks of intravenous ascorbate therapy (300 mg three times a week) in 12 hemodialysis patients with serum ferritin levels of more than 500 μg/liter. The enhanced erythropoiesis paralleled with a rise in transferrin saturation (27.8 ± 2.5% vs. 44.8 ± 9.5%, P < 0.05) and reductions in erythrocyte zinc protoporphyrin (130 ± 32 vs. 72 ± 19 mmol/mol heme, P < 0.05) and monthly rHuEPO dose (24.2 ± 4.5 vs. 16.8 ± 3.4 3 103units, P < 0.05) at the end of study. It is speculated that ascorbate supplementation not only facilitates the iron release from storage sites and its delivery to hematopoietic tissues, but also increases iron utilization in ery-throid cells. Our study provides a more complete understanding of the pathogenesis of iron overload-related anemia and the development of an adjuvant therapy, intravenous ascorbic acid, to the existing treatments. [ABSTRACT FROM AUTHOR]

The article reports on the case of a 64 year old man who presented to physicians with painless right leg swelling that had lasted for five years. A discussion of diagnostic testing which was done on the man and resulted in a diagnosis of hypercalcemia, nephrolithiasis and a leg mass is presented. The man's treatment and recovery are discussed.