Effects of parathyroid hormone and vitamin D supplementation on stroke among patients receiving peritoneal dialysis.

BACKGROUND: Continuous ambulatory peritoneal dialysis (CAPD) patients have a high incidence of stroke and commonly have increased parathyroid hormone levels and vitamin D insufficiency. We seek to investigate the incidence of stroke and the role of parathyroid hormone and vitamin D supplementation in stroke risk among CAPD patients. METHODS: This study employed a retrospective design. We enrolled a Chinese cohort of 980 CAPD patients who were routinely followed in our department. The demographic and clinical data were recorded at the time of initial CAPD and during follow-up. The included patients were separated into non-stroke and stroke groups. The effects of parathyroid hormone and vitamin D supplementation on stroke in CAPD patients was evaluated. The primary endpoint is defined as the first occurrence of stroke, and composite endpoint events are defined as death or switch to hemodialysis during follow-up. RESULTS: A total of 757 eligible CAPD patients with a mean follow-up time of 54.7 (standard deviation, 33) months were included in the study. The median incidence of stroke among our CAPD patients was 18.9 (interquartile range, 15.7-22.1) per 1000 person-years. A significant nonlinear correlation between baseline iPTH and hazard of stroke (p-value of linear association = 0.2 and nonlinear association = 0.002) was observed in our univariate Cox regression analysis, and low baseline iPTH levels (≤150 pg/ml) were associated with an increased cumulative hazard of stroke. Multivariate Cox regression analysis indicated a significant interaction effect between age and iPTH after adjusting for other confounders. Vitamin D supplementation during follow-up was a predictive factor for stroke in our cohort. CONCLUSIONS: CAPD patients suffered a high risk of stroke, and lower iPTH levels were significantly correlated with an increased risk of stroke. Nevertheless, vitamin D supplementation may reduce the risk of stroke in these patients.

Establishment of an in vitro system based on AGM-S3 co-culture for screening traditional herbal medicines that stimulate hematopoiesis.

ETHNOPHARMACOLOGICAL RELEVANCE: Spatholobus suberectus Dunn is a traditional Chinese medicine (TCM) that can activate blood, dispel stasis, inhibit platelet aggregation, and stimulate hematopoiesis, and thereby treat anemia and diseases related to blood stasis syndrome (BSS). However, its hematopoiesis-stimulating activity is not well understood. AIM OF STUDY: Four phenolic compounds (daidzein, formononetin, catechin, and procyandin B2) were isolated and purified from stems of S. suberectus, and tested using an in vitro hematopoiesis system. MATERIALS AND METHODS: An AGM-S3 co-culture system for hematopoiesis derived from human embryonic stem cells (hESCs) was employed to explore effects on hematopoiesis. At different stages, extracts from Spatholobus suberectus Dunn were added to the co-culture system at concentrations of 2, 10, or 50 µM, and fluorescence-activated cell sorting (FACS), hematopoietic colony culturing, and quantitative reverse transcription PCR (qRT-PCR) were used to probe changes in hematopoietic progenitors and erythroid progenitors. RESULTS: When H1 hESCs co-cultured with AGM-S3 were added along with 10 µM catechin from day 12 (D12), proliferation and differentiation of hematopoietic and erythroid progenitors from hESCs was increased based on FACS with antibodies recognizing CD34/CD45 and GPA/CD71. Hematopoiesis colony culturing further confirmed the promotion effect of catechin on hematopoiesis, and other active fractions did not significantly promote hematopoiesis. qRT-PCR revealed that some important genes related to hematopoiesis and erythroid were up-regulated followed catechin exposure. CONCLUSIONS: Our results demonstrate that catechin, an active ingredient of Spatholobus suberectus Dunn, can increase the efficiency of hematopoiesis, including hematopoietic and erythroid progenitors, consistent with previous reports. The AGM-S3 co-culture system could provide an effective tool for screening active compounds in TCMs that promote hematopoiesis, and may be of clinical and pharmaceutical use.