Asymmetric triacetate membrane keeps high water flux during ultrafiltration: in vitro study

Leakage of Endotoxins through the Endotoxin Retentive Filter: An in vitro Study

INTRODUCTION

Ultrapurification of dialysis fluid has enabled highly efficient dialysis treatments. Online hemodiafiltration is one such treatment that uses a purified dialysis fluid as a supplemental fluid. In this method, an endotoxin retentive filter (ETRF) is used in the final step of dialysis fluid purification, with the aim of preventing leakage of endotoxins. Sodium hypochlorite and peracetic acid are used as disinfecting agents for the dialysis fluid pipes containing the ETRF; however, the effects of these agents on ETRF membrane pores have not been fully clarified.

METHODS

Water permeability (flux) and endotoxin permeability were assessed in 3 types of ETRFs made with different membrane materials: polyester polymer alloy (PEPA), polyether sulfone (PES), and polysulfone (PS). High-concentration sodium hypochlorite and 2 types of peracetic acid were used as disinfecting agents, and the changes in flux and the endotoxin sieving coefficient (SC) were measured.

RESULTS

After repeated use of high concentrations of sodium hypochlorite and peracetic acid, the PEPA and PES ETRFs did not permit passage of endotoxins, regardless of their flux. However, in the PS ETRF, the flux and endotoxin SC increased with the number of cleaning cycles. No differences were observed according to the concentration of peracetic acid disinfecting agents.

CONCLUSION

PEPA and PES ETRFs completely prevent endotoxin leakage and can be disinfected at concentrations higher than the conventionally recommended concentration without affecting pore expansion. Even new PS ETRFs have low levels of endotoxin leakage, which increase after disinfection cycles using sodium hypochlorite and peracetic acid.

Nitric oxide delivery using nitric oxide-containing fluid in continuous hemofiltration: an in vitro study

Administering nitrite has therapeutic effects on ischemic conditions wherein the enzymatic production of nitric oxide depends on oxygen. We developed a supplemental fluid containing nitric oxide (NO) and determined the clearance and supply between the pre- and post-dilution modes of continuous hemofiltration in vitro. Nitric oxide gas, 1000 mL or 2000 mL, at a concentration of 1000 ppm, was injected into 2020 mL of conventional supplemental fluid (experimental solution). The same volume of nitrogen gas was injected into the supplemental fluid (control solution). NO concentrations were measured using commercially available NO assay kit. Pre- or post-dilution continuous hemofiltration was performed using a control solution as supplemental fluid to determine the NO clearance. We determined the NO concentration of the outlet blood circuit to confirm the NO supply using the experimental solution as supplemental fluid. Also, using the bovine blood, white blood cell and platelet change rates and the dialysis membrane water flux during continuous hemodiafiltration were evaluated ex vivo as index of the biocompatibilities of a nitric oxide-containing solution. NO was not detected in the control solutions. The experimental solutions significantly increased in nitric oxide concentrations. NO clearance increased as the increase in supplemental and ultrafiltration flow rates using the control solution as supplemental fluid. However, using the experimental solution as supplemental fluid, nitric oxide supply showed a similar trend of NO clearance. Without any changes in biocompatibility using the supplemental fluid containing NO, it could maintain intravascular nitric oxide during continuous renal replacement therapy.

Down-regulated long non-coding RNA ANRIL restores the learning and memory abilities and rescues hippocampal pyramidal neurons from apoptosis in streptozotocin-induced diabetic rats via the NF-κB signaling pathway

Diabetes often causes learning and memory deficits, which leads to unfavorable behavioral performance. In this study, we investigated the effects of long non-coding RNA (lncRNA) ANRIL on learning, memory abilities, and hippocampal neuronal apoptosis via the NF-κB signaling pathway in streptozotocin (STZ)-induced diabetic rats. After successful establishment of diabetic rat models, the subjects were then assigned into the DM, DM + si-ANRIL, DM + si-negative control (si-NC) groups, as well as an additional normal group. Morris water maze test was employed to assess behavioral performance of rats, followed by the recording of body weight and blood glucose levels. Expressions of ANRIL, NF-κB signaling pathway-related, and apoptosis-related genes were examined by qRT-PCR and western blotting. Rat hippocampus expression levels of cleaved-caspase-3 were determined by immunofluorescence. Cell apoptosis was examined by TUNEL assay. Versus to the normal group, revealed there to be activation of the NF-κB signaling pathway, decreased weight, increased blood glucose, increased escape latency, reduced residence time, memory impairment, increased cleaved-caspase-3 expression, and increased apoptosis were detected in the DM and DM + si-NC groups. The DM + si-ANRIL group exhibited inhibited NF-κB signaling pathway, weight loss, decreased blood glucose, recovered memory, decreased cleaved-caspase-3 expression and reduced apoptosis compared to the DM group, with higher weight of rats, lower blood glucose levels, and stronger memory abilities in the DM + si-ANRIL group. Taken together, these findings indicate that silencing lncRNA ANRIL promotes memory recovery and decreases hippocampal neurons apoptosis in diabetic rats through the inhibition of the NF-κB signaling pathway.