[Clinical analysis of drug-induced Pseudo-Bartter's syndrome: a report of five cases].

OBJECTIVE: To summarize the clinical characteristics and outcomes of Pseudo-Bartter's syndrome and explore its pathogenesis. METHODS: The clinical data of 5 cases of Pseudo-Bartter's syndrome at our ward from May 2008 to December 2010 was analyzed retrospectively. RESULTS: All patients were female. Long-term regimen of purgative or diuretics was prescribed. The clinical features included normotension, hypokalemic alkalosis and activation of renin-angiotensin-aldosterone. The pathological results of 3 cases of kidney biopsy showed the hyperplasia of juxtaglomerular apparatus, thickness of arteriole, infiltration of lymphocytes and monocytes and degeneration of renal tubule. Upon a definitive diagnosis, purgative or diuretics was discontinued and supplement therapy of potassium chloride initiated. The results of laboratory tests reverted to normal ranges within 4 weeks. CONCLUSION: Purgative or diuretics should be prescribed appropriately to avoid the occurrence of Pseudo-Bartter's syndrome.

Expression and cellular distribution of TLR4, MyD88, and NF-κB in diabetic renal tubulointerstitial fibrosis, in vitro and in vivo.

AIM: Inflammation and extracellular matrix hyperplasia are crucial in the pathogenesis of tubulointerstitial fibrosis (TIF) involved in diabetic nephropathy (DN). Macrophage accumulation plays a major role, but whether immune factors contribute to DN pathogenesis is not well understood. This study aimed to investigate TLR4-MyD88-NF-κB-dependent pathway's involvement in TIF pathogenesis. METHODS: STZ-induced diabetic rats and rat renal tubular epithelial NRK-52E cells cultured under high glucose conditions were used as in vivo and in vitro models, respectively. Real-time RT-PCR, western blot, immunohistochemistry and immunofluorescence were performed to examine the mRNA and protein levels of TLR4, MyD88, NF-κB, MCP-1, and α-SMA. RESULTS: Compared with 5.5 mmol/L glucose, treatment of NRK-52E cells with 25 and 50 mmol/L d-glucose resulted in significantly increased TLR4 and MyD88 mRNA and protein levels (P<0.05). TLR4 and MyD88 were detected in the cytoplasm of most NRK-52E cells cultured under high glucose. Pronounced damage in the renal tubulointerstitium was observed in diabetic rats (scores: 3.82 ± 0.65 vs. 0.38 ± 0.08, P<0.01). Compared with the normal controls, a sharp upregulation of TLR4, MyD88, NF-κB p65, MCP-1, and α-SMA mRNA and protein levels was observed in diabetic rat kidneys (P<0.05). In diabetic animals, TLR4 and MyD88 were strongly expressed in the cytoplasm, while NF-κB p65 was widely expressed in cytoplasm and nuclei of renal tubular epithelial cells. CONCLUSION: The inflammatory reaction and epithelial-mesenchymal transformation observed in renal tubulointerstitium may be the result of overactivation of the TLR4-MyD88-NF-κB-dependent innate immunity under high glucose, and may be involved in DN occurrence and progression.