Is Peritoneal Dialysis a Suitable Renal Replacement Therapy Option for Polycystic Kidney Disease Patients?

Background/Aims: Mounting clinical experience and evidence from scale observational studies have suggested that polycystic kidney disease (PKD) was not a contraindication for peritoneal dialysis (PD). Recent studies have reported that PD may be associated with a better prognosis in PKD than that of non-PKD patients. To solve the problem, we performed a systematic review and comprehensive meta-analysis to compare the outcomes between PKD and non-PKD patients on PD and the all-cause mortality between patients with PKD on PD and hemodialysis (HD). Methods: We conducted a systematic literature using electronic databases (PubMed, Ovid, Embase and Web of Science) to identify the studies reporting the endpoint events of PKD/non-PKD patients with PD and the all-cause mortality between patients with PKD on PD and HD, such as dialysis adequacy, technique failure, PD-related complications, the mode of RRT change, and all-cause mortality. We searched the literature published February 2018 or earlier. We used both fix-effects and random-effects models to calculate the overall effect estimate. A sensitivity analysis and subgroup analysis were performed to find the origin of heterogeneity. Results: 12 studies with a total of 17,040 patients reported the endpoint events of PKD/non-PKD patients with PD. No significant difference was observed on dialysis adequacy (Kt/V, SMD: -0.02, 95%CI: -0.12–0.08; D: Pcr (4h), SMD: -0.10, 95% CI: -0.26–0.06), technique failure (RR: 0.97, 95%CI: 0.78-1.20), RRT change (RR: 0.96, 95%CI: 0.77-1.19), total PD-associated complications (RR: 1.0, 95%CI: 0.91-1.09) and all-cause mortality (RR: 0.40, 95%CI: 0.33–0.47) in PKD patients, compared with non-PKD subjects undergoing PD. However, the proportion of renal transplantation in PKD patients was higher than that of non-PKD patients (RR: 2.04, 95%CI: 1.88–2.20) with significant heterogeneity (I2 =82.7%, P=0.000). 4 studies with a total of 5,762 patients reported that the all-cause mortality did not differ between the PKD patients on PD and HD (RR: 0.87, 95%CI: 0.72-1.06). Conclusion: Our meta-analysis found that the outcomes of given population of PKD patients on PD were at least not inferior as compared to those with other primary kidney diseases, and suggested that PKD might be not absolutely a contraindication for PD. Given the limitations of the proposed, it needs further large-scale studies to assess whether PD is a suitable RRT option for end-stage renal disease (ESRD) patients with PKD

Application of EPMA and LA-ICP-MS to Study Mineralogy of Arsenopyrite from the Haoyaoerhudong Gold Deposit, Inner Mongolia, China

BACKGROUND: The composition of major and trace elements in arsenopyrite can be used to identify the occurrence of elements and explore the remobilization and migration behaviour of elements in different stages. The Haoyaoerhudong gold deposit in Inner Mongolia is a super large gold deposit hosted in the black shales of the Bayan Obo Group. Gold-bearing minerals such as arsenopyrite and loellingite are present. Previous researchers have used the traditional powder dissolution method to analyze the isotope of the ore and discussed the source of ore-forming materials, but the migration and enrichment mechanism of gold has not been unraveled.OBJECTIVES: To understand the gold migration and enrichment process of this deposit.METHODS: Based on mineralogy, different types of arsenopyrite were analyzed by electron probe microanalyzer (EPMA) and inductively coupled plasma-mass spectrometry (ICP-MS). The data measured by EPMA was corrected by ZAF program, and the data measured by LA-ICP-MS was quantitatively calculated by "no internal standard-matrix normalized calibration".RESULTS: The results showed that loellingite was developed in arsenopyrite. They can be divided into Apy-Ⅰ1, Apy-Ⅰ2, Lo-Ⅰ in progressive shear deformation stage and Apy-Ⅱ1, Apy-Ⅱ2 and Lo-Ⅱ in post shear deformation stage. The major element composition of arsenopyrite in different generations was stable, with a small amount of Co and Ni and a trace amount of Sb, Te, Bi, Pb, Au and Ag. Cobalt was higher in Apy-Ⅱ1 and Apy-Ⅱ2, whereas Au, Bi, Pb and Te were obviously enriched in Apy-Ⅰ1. Loellingite was rich in As (64.06%-67.87%), Co (0.33%-4.98%), Ni (1.23%-6.37%). Trace elements such as Au, Te, Bi, Pb and Ag were more enriched in Lo-Ⅱ.CONCLUSIONS: Lo-Ⅱ is the most important gold-bearing mineral. The changes of temperature and sulfur fugacity lead to the precipitation of loellingite and native gold. Native gold is precipitated by remobilization and migration of "invisible gold" in early arsenopyrite and loellingite

Hirudin Ameliorates Renal Interstitial Fibrosis via Regulating TGF-β1/Smad and NF-κB Signaling in UUO Rat Model

Purpose. Hirudin, a polypeptide structure containing 65 amino acids, is a potent natural thrombin inhibitor with anticoagulant property extracted from Hirudo medicinalis. It has been reported to have anti-inflammatory and antifibrotic property. Here we explored the renoprotective effect of hirudin on unilateral ureteral obstruction (UUO) induced renal interstitial fibrosis (RIF). Methods. Rats were randomly divided into five groups: sham group, UUO alone group, and three UUO + hirudin-treatment groups (10, 20, or 40 IU/kg/d, for 14 continuous days). At the end of the experiment period, animals were sacrificed. Pathologic changes in renal specimens were observed using hematoxylin and eosin (HE) staining and Masson staining. The expressions of collagen III (Col III), fibronectin (FN), α-smooth muscle actin (α-SMA), protease-activated receptor 1 (PAR-1), and proteins in the TGF-β1/Smad and NF-κB pathways in renal tissues were examined by immunohistochemistry and/or Western blotting. Results. HE and Masson staining showed that hirudin-treated UUO rats had lower extent of renal injury and deposition of extracellular matrix (ECM) in renal interstitium than those in the UUO group. The results of immunohistochemistry and WB indicated decreased protein expressions of Col III, FN, α-SMA, PAR-1, and inflammatory markers such as tumor necrosis factor-α and interleukin-6 after hirudin treatment. Furthermore, hirudin reduced the expressions of transforming growth factor β1 (TGF-β1), phosphorylated-Smad2, and phosphorylated-Smad3 in the UUO model. In parallel, we found inhibited nuclear factor-κB (NF-κB) signaling after hirudin treatment, with downregulated protein expressions of P65, phosphorylated-P65, and phosphorylated-iκBα and increased iκBα. Conclusion. Hirudin improves kidney injury and suppresses inflammatory response and ECM accumulation in UUO rats; its underlying mechanism may be associated with the inhibition of TGF-β1/Smad and NF-κB signaling

Key Technologies for an Orchard Variable-Rate Sprayer: Current Status and Future Prospects

An orchard variable-rate sprayer applies the appropriate amount of plant protection products only where they are needed based on detection data from advanced sensors, a system that has attracted increasing attention. The latest developments in the detection unit, variable control unit, and signal-processing algorithm of the variable-rate sprayer are discussed. The detection of target position and volume is realized with an ultrasonic sensor, a laser scanning sensor, or other methods. The technology of real-time acquisition of foliage density, plant diseases and pests and their severity, as well as meteorological parameters needs further improvements. Among the three variable-flow-rate control units, pulse width modulation was the most widely used, followed by pressure-based, and variable concentration, which is preliminarily verified in the laboratory. The variable air supply control unit is tested both in the laboratory and in field experiments. The tree-row-volume model, the leaf-wall-area model, and the continuous application mode are widely used algorithms. Advanced research on a variable-rate sprayer is analyzed and future prospects are pointed out. A laser-based variable-rate intelligent sprayer equipped with pulse width modulation solenoid valves to tune spray outputs in real time based on target structures may have the potential to be successfully adopted by growers on a large scale in the foreseeable future. It will be a future research direction to develop an intelligent multi-sensor-fusion variable-rate sprayer based on target crop characteristics, plant diseases and pests and their severity, as well as meteorological conditions while achieving multi-variable control