A comparative analysis of the efficacy and safety of paricalcitol versus other vitamin D receptor activators in patients undergoing hemodialysis: A systematic review and meta-analysis of 15 randomized controlled trials.

Paricalcitol, a new vitamin D receptor activator (VDRA), is reported to be more effective than other VDRAs in reducing calcium and phosphorus levels in patients undergoing hemodialysis. However, the efficacy and safety of paricalcitol remain controversial. This analysis compares paricalcitol with other VDRAs in patients undergoing hemodialysis. We searched the Cochrane Library, PubMed, EMBASE, Web of Science, and CNKI up to April 22, 2019. Standardized mean difference (SMD), risk ratio (RR) and 95% confidence interval (CI) values were estimated to compare the outcomes of the groups. Two reviewers extracted data and assessed trial quality independently. All statistical analyses were performed using the standard statistical procedures of RevMan 5.2 and Stata 12.0. Fifteen studies (N = 110,544) were included in this meta-analysis. Of these studies, 11 were randomized controlled trials (RCTs) and 4 were non-randomized studies of interventions (NRSIs). Patients receiving paricalcitol experienced better overall survival (OS) than patients receiving other VDRAs, with a pooled hazard ratio of 0.86 (95% CI 0.80-0.91; P < 0.00001). Intact parathyroid hormone (iPTH) levels were significantly reduced in the paricalcitol group compared to the group receiving other VDRAs, with a pooled SMD of -0.53 (95% CI -0.89- -0.16; P = 0.004). There was a significant increase in serum calcium levels from baseline in the paricalcitol group compared to the other VDRAs group when limiting the analysis to RCTs, with a pooled SMD of 2.14 (95% CI 0.90-3.38; P = 0.0007). Changes in serum calcium levels were significantly lower in the paricalcitol group when the analysis was limited to NRSIs, with a pooled SMD of -0.85 (95% CI -1.34--0.35; P = 0.0008). The NSRI analysis also showed a significant reduction in serum phosphorus levels in the paricalcitol group, with a pooled SMD of -0.57 (95% CI -1.00--0.13; P = 0.01). No significant differences were observed in the incidence of hypercalcemia, hyperphosphatemia, or adverse events. Generally, paricalcitol seems superior to other VDRAs in reducing mortality and iPTH levels in patients undergoing hemodialysis. However, the comparative effectiveness of paricalcitol in reducing serum calcium and phosphorus levels needs further exploration. No significant difference was found in the rate of adverse events.

Effects of epiphytic algae on biomass and physiology of Myriophyllum spicatum L. with the increase of nitrogen and phosphorus availability in the water body.

The disappearance of submerged vascular macrophytes in shallow eutrophic lakes is a common phenomenon in the world. To explore the mechanism of the decline in submerged macrophyte abundance due to the growth of epiphytic algae along a nutrient gradient in eutrophic water, a 2 × 3 factorial experiment was performed over 4 weeks with the submerged macrophyte (Myriophyllum spicatum L.) by determining the plant's biomass and some physiological indexes, such as chlorophyll (Chl) content, malondialdehyde (MDA) content, and superoxide dismutase (SOD) activity in the leaves of M. spicatum L. on days 7, 14, 21, and 28, which are based on three groups of nitrogen and phosphorus levels in the water body (N-P [mg L-1]: NP1 0.5-0.05, NP2 2.5-0.25, NP3 4.5-0.45) and two levels of epiphytic algae (the epiphytic algae group and the control group). Epiphytic algal biomass was also assayed. The results indicated that epiphytic algal biomass remarkably enhanced in the course of the experiment with elevated levels of nitrogen and phosphorus in the water. Under the same level of nutrient condition, plants' biomass accumulation and Chl content were higher in the control group than that in the epiphytic algae group, respectively, while MDA content and SOD activity in the former were lower than that in the latter. The influences of epiphytic algae on the biomass accumulation and Chl content and MDA content became greater and greater with elevated levels of nutrients. In general, in this experiment, water nutrients promoted the growth of both epiphytic algae and submerged plants, while the growth of epiphytic algae hindered submerged macrophytes' growth by reducing Chl content and promoting peroxidation of membrane lipids in plants.

Causes of large Potamogeton crispus L. population increase in Xuanwu Lake.

In July 2005, the first outbreak of cyanobacterial blooms, dominated by Microcystis, occurred in Xuanwu Lake, Nanjing, upon which clay flocculation was adopted to control algal blooms. The cyanobacterial blooms were restrained, after which Potamogeton crispus appeared in November 2005 and spread rapidly in the whole lake. Since then, large populations of P. crispus have occurred in Xuanwu Lake annually in winter for the last 10 years. To determine the reasons for the occurrence of P. crispus populations in Xuanwu Lake during 2005-2006, water quality indices were monitored regularly. The data collected included dissolved oxygen, transparency, pH, total nitrogen, and total phosphorus content. Data analysis indicated that the transparency was improved by 179.5 % after clay flocculation, dissolved oxygen content increased by 24.1 %; total nitrogen and total phosphorus content decreased by 54.1 and 74.5 %, respectively, and pH fell from 9.1 to 8.7, all of which can be attributed to the emergency control measures for the cyanobacterial bloom. Data analysis also indicated that the improved water transparency after clay flocculation was the key factor in turion sprouting and seedling propagation of P. crispus. The ameliorative light intensity and favorable nutrient level all promoted the growth of seedlings of P. crispus and later quick colonization. It is suggested that ecological restoration of macrophytic and algal lakes be conducted by some physical or chemical means to improve transparency, reduce nutrient concentration, and adjust water pH, with the purpose of improving water quality for germination and growth of aquatic plants.

[Spatial and Temporal Distribution Characteristics of Different Forms of Phosphorus in Three Sorts of Rivers around Lake Taihu].

Different forms of phosphorus from the upper reaches of river to lower reaches of river in nine rivers were analyzed to clarify the pollution characteristics of industrial effluent, agriculture effluent and sanitary wastewater to Lake Taihu in February (low water period), May (average water period) and August (abundant water period) of 2009. The results showed that total phosphorus (TP) dissolved total phosphorus (DTP) and soluble reactive phosphorus ( SRP) mass concentration all showed decreasing trend while enzymatic phosphorus (EHP) mass concentration increased with the increase of algal biomass from low water period to abundant water period. Mass concentrations of several forms of phosphorus were all the highest in the rivers impacted by sanitary wastewater, but sanitary wastewater's self-purification capabity from the upper reaches of river to lower reaches of river was the best, and the pollution to Lake Taihu was the lowest. Pollution from rivers impacted by industrial effluent was the highest. Mass concentration of EHP was higher than that of SRP in most cases, so EHP played an important role in Cyanbacterial harmful algal blooms events in Lake Taihu.

The physiological responses of Vallisneria natans to epiphytic algae with the increase of N and P concentrations in water bodies.

To reveal the mechanism of submerged plants decline in progressively eutrophicated freshwaters, physiological responses of Vallisneria natans to epiphytic algae were studied in simulation lab by measuring plant physiological indexes of chlorophyll content, malondialdehyde (MDA) content, and superoxide dismutase (SOD) activity based on a 2 × 4 factorial design with two epiphytic conditions (with epiphytic algae and without) and four levels of N and P concentrations in water (N-P[mg.L(-1)]: 0.5, 0.05; 2.5, 0.25; 4.5, 0.45; 12.5, 1.25). Compared with control (non-presence of epiphytic algae), chlorophyll contents of V. natans were significantly decreased (p < 0.01) for the presence of epiphytic algae under any concentrations of N and P in water bodies. While the presence of epiphytic algae induced peroxidation of membrane lipids, MDA contents of V. natans had significantly increased (p < 0.05) by comparing with control. SOD activity significantly enhanced (p < 0.05) with the presence of epiphytic algae in the treatments of T2 and T3 in the whole culture process by comparing with control, sometimes reaching an extremely significant level (p < 0.01). However, in the treatments of T1 and T4, SOD activity had no obvious change with the presence of epiphytic algae (p < 0.05) by comparing with control. At the end of the experiment, the effects of epiphytic algae on chlorophyll content and SOD activity in the leaves of V. natans were increased at first and then decreased with the concentrations of N and P in water, and MDA content became higher with the increase of N and P. concentrations. Repeated measurement data testing showed that the effects of epiphytic algae on the chlorophyll content and MDA content and SOD activity were significant, respectively (p < 0.001), the effects of epiphytic algae were combining with effects of concentrations of N and P (p < 0.001), respectively, and their interaction (p < 0.001). Our observations confirmed that this prediction: the growth of epiphytic algae directly produced adverse effects on physiology of V. natans and epiphytic algal biomass were positively correlated with nutrient available in the water column.

[Physiological response of Vallisneria natans to nitrogen and phosphorus contents in eutrophic waterbody].

The response of Vallisneria natans to the increase contents of nitrogen and phosphorus were studied under laboratory conditions by measuring chlorophyll fluorescence parameters of V. natans using a pulse-amplitude modulated fluorometer (Diving-PAM), combined with measuring some other physiological indexes of V. natans. The results showed that V. natans responded quickly to water nitrogen and phosphorus concentration changes, the maximum quantum yield decreased significantly after 2 h and 6 h, the maximum quanta yield returned to normal levels 12 h after the treatment. There was no significant difference between treatment groups for the maximum quantum yield. Inhibitory effect of light intensity on photosynthesis of V. natans was more obvious under higher (treatment D) or lower (treatment A) concentrations of nitrogen and phosphorus. The average quantum yields of four measurements in the treatment B or C was significantly higher than that of A or D (p < 0.05). Within a certain range, chlorophyll content increased significantly with the nitrogen and phosphorus concentrations. When nitrogen and phosphorus concentrations further increased and reached the level of D treatment, chlorophyll content of V. natans decreased. Malondialdehyde (MDA) content of V. natans changed in the different treatment groups, MDA content of treatment B was the lowest while treatment D was the highest. It shows that V. natans is more suitable for growing in eutrophic waterbodies, but excessive nitrogen and phosphorus could inhibit the physiological activities of V. natans.