Hyperkalemia increases the risk of sudden cardiac death (SCD) in hemodialysis patients. Our objective was to determine the association between administering low potassium dialysate to hyperkalemic hemodialysis patients and SCD. We conducted a retrospective cohort study with patients undergoing maintenance hemodialysis from May 1, 2006, through December 31, 2013. The dialysate composition was adjusted over time according to monthly laboratory results. A 1.0 mEq/L potassium dialysate was applied in patients with predialysis hyperkalemia (>5.5 mEq/L) and was included as a time-dependent confounding factor. The clinical characteristics of enrolled patients, the incidence and timing of SCD and risk factors for all-cause mortality and SCD were analyzed. There were 312 patients on maintenance hemodialysis during the study period. One hundred and fifty-seven patients had been dialyzed against a 1.0 mEq/L potassium dialysate at least once. The rates of all-cause mortality and SCD were 48.17 and 20.74 per 1000 patient-years, respectively. A 1.12-fold increase in the risk of SCD in the 24-hour period starting with the hemodialysis procedure and a 1.36-fold increase in the 24 hours preceding a weekly cycle were found (p = 0.017). Multivariate Cox proportional hazards models showed that age, diabetes mellitus and predialysis hyperkalemia (>5.0 mEq/L) were significant predictors of all-cause mortality and SCD. Exposure to 1.0 mEq/L potassium dialysate, Kt/V, and serum albumin were independent protective factors against all-cause mortality. Only exposure to 1.0 mEq/L potassium dialysate significantly prevented SCD (hazard ratio = 0.33, 95% CI = 0.13–0.85). Using low potassium dialysate in hyperkalemic hemodialysis patients may prevent SCD.

Ketamine-associated diseases have been increasing with the rise in ketamine abuse. Ketamine-associated uropathy is one of the most common complications. We investigated the effects of ketamine-associated uropathy on renal health and determined predictors of renal function decline in chronic ketamine abusers. This retrospective cohort study analyzed 51 patients (22 with ketamine-associated hydronephrosis and 29 with ketamine cystitis) from Kaohsiung Veterans General Hospital in Taiwan. Primary renal outcome was end-stage renal disease or estimated glomerular filtration rate decline >30% from baseline. Compared with the ketamine cystitis group, the hydronephrosis group had lower initial and final estimated glomerular filtration rates and higher alkaline phosphatase and gamma-glutamyl transferase levels (p < 0.05). Elevated cholestatic liver enzyme levels correlated with renal dysfunction in ketamine-associated uropathy. The hydronephrosis group had a higher proportion of patients reaching endpoints than the ketamine cystitis group (50% and 7%, respectively, p < 0.001). After adjusting for age, sex, and initial serum creatinine level, hydronephrosis remained an independent risk factor for renal function deterioration. Ketamine-associated hydronephrosis was a poor renal outcome and strong predictor of renal function decline in chronic ketamine abusers. Elevated cholestatic liver enzyme levels correlated with the severity of ketamine-associated uropathy. Ultrasonography screening of these high-risk groups and regular renal function follow-ups are necessary.

Angiogenesis, the process of neovascularization, plays an important role in physiological and pathological conditions. ST104P is a soluble polysulfated-cyclo-tetrachromotropylene compound with anti-viral and anti-thrombotic activities. However, the functions of ST104P in angiogenesis have never been explored. In this study, we investigated the effects of ST104P in angiogenesis in vitro and in vivo. Application of ST104P potently suppressed the microvessels sprouting in aortic rings ex vivo. Furthermore, ST104P treatment significantly disrupted the vessels’ development in transgenic zebrafish in vivo. Above all, repeated administration of ST104P resulted in delayed tumor growth and prolonged the life span of mice bearing Lewis lung carcinoma. Mechanistic studies revealed that ST104P potently inhibited the migration, tube formation and wound closure of human umbilical endothelial cells (HUVECs). Moreover, ST104P treatment inhibited the secretion and expression of matrix metalloproteinase-2 (MMP-2) in a dose-dependent manner. Together, these results suggest that ST104P is a potent angiogenesis inhibitor and may hold potential for treatment of diseases due to excessive angiogenesis including cancer.

We intended to explore the cellular interaction between mesenchymal stem cells (MSCs) and injured endothelial cells leading to macrophage alternative polarization in healing kidney ischemic reperfusion injury. In vivo, the amounts of recruited macrophages were significantly mitigated by MSCs in the injured tissues, especially in the group using hematopoietic cell E- and L-selectin ligand (HCELL)-positive MSCs. Compared to controls, MSCs also enhanced expression of CD206 and CD163, which was further enhanced by HCELL expression. In vitro, analysis of cytokines involving macrophage polarization showed IL-13 rather than IL-4 from MSCs agreed with expression of macrophage CD206 in the presence of hypoxic endothelial cells. Among them, HCELL-positive MSCs in contact with hypoxic endothelial cells produced the greatest response, which were reduced without HCELL or using a transwell to prevent cell contact. With blockade of the respective cytokine, downregulated MSCs secretion of IL-13 and CD206 expression were observed using inhibitors of IFN-γ and TNF-α, but not using those of TGF-β and NO. With IFN-γ and TNF-α, MSCs IL-13 secretion and CD206 expression were upregulated. In conclusion, hypoxia induces endothelial cells producing multiple cytokines. Among them, IFN-γ and TNF-α that stimulate MSCs to secrete IL-13 but not IL-4, leading to alternative polarization.