In vitro trials of a wearable artificial kidney (WAK)

2017 ◽  
Vol 41 (2) ◽  
pp. 84-88 ◽  
Author(s):  
Nikolai A. Bazaev ◽  
Nataliya I. Dorofeeva ◽  
Nikita M. Zhilo ◽  
Evgeniy V. Streltsov
Keyword(s):  
Uric Acid ◽  
Measuring Equipment ◽  
Test Bench ◽  
Artificial Kidney ◽  
Dialysis Fluid ◽  
Initial Values ◽  
Metabolite Concentrations ◽  
Spent Dialysate ◽  
Wearable Artificial Kidney

Background: This paper presents results of in vitro trials of a wearable artificial kidney (WAK). Materials and methods: To carry out the trials, a test bench was developed. It consisted of a patient imitator, a tubing set and measuring equipment. Results: Our WAK can eliminate urea, uric acid and creatinine from spent dialysate with mean mass rates of 0.85 ± 0.1 g/h, 0.10 ± 0.04 g/h and 0.05 ± 0.01 g/h, respectively. Concentrations of Na+, Cl– and Ca2+ ions were kept in the 10% range from initial values. We demonstrated that our WAK can operate for 38 hours without having to replace expendable materials. Conclusions: The WAK that we developed can eliminate metabolites from spent dialysis fluid with mass rates that are sufficient to maintain stable, physiologically normal metabolite concentrations in patients’ blood.

scholarly journals Uric Acid Is a Genuine Metabolite of Penicillium cyclopium and Stimulates the Expression of Alkaloid Biosynthesis in This Fungus

2002 ◽  
Vol 68 (4) ◽  
pp. 1524-1533 ◽  
Author(s):  
Florian Helbig ◽  
Jörg Steighardt ◽  
Werner Roos
Keyword(s):  
Uric Acid ◽  
Low Molecular Weight ◽  
Alkaloid Production ◽  
Alkaloid Biosynthesis ◽  
Penicillium Cyclopium ◽  
Measurable Activity ◽  
Reduced Rate ◽  
Rate Limiting

ABSTRACT On searching for endogenous, low-molecular-weight effectors of benzodiazepine alkaloid biosynthesis in Penicillium cyclopium uric acid was isolated from ethanolic or autoclaved mycelial extracts of this fungus. The isolation was based on a three-step high-pressure liquid chromatography procedure guided by a microplate bioassay, and uric acid was identified by mass spectrometry and the uricase reaction. Conidiospore suspensions that were treated with this compound during the early phase of outgrowth developed emerged cultures with an enhanced rate of alkaloid production. Uric acid treatment did not increase the in vitro measurable activity of the rate-limiting biosynthetic enzyme, cyclopeptine synthetase. However, these cultures displayed a reduced rate of uptake of the alkaloid precursor l-phenylalanine into the vacuoles of the hyphal cells as assayed in situ. It is suggested that the depressed capacity of vacuolar uptake caused by the contact of outgrowing spores with uric acid liberated from hyphal cells results in an enhanced availability of the precursor l-phenylalanine in the cytoplasm and thus accounts at least in part for the increase in alkaloid production.

Measuring equipment and test bench to control evolution of acoustic-deformation and heat fields induced in solids under failure by fluids

2015 ◽  
Vol 51 (3) ◽  
pp. 624-633 ◽  
Author(s):  
V. N. Oparin ◽  
V. I. Vostrikov ◽  
O. M. Usol’tseva ◽  
P. A. Tsoi ◽  
V. N. Semenov
Keyword(s):  
Measuring Equipment ◽  
Test Bench

Bmk9 and Uricase Nanoparticle Complex for the Treatment of Gouty Arthritis and Uric Acid Nephropathy

2021 ◽  
Vol 17 (10) ◽  
pp. 2071-2084
Author(s):  
Tianjiao Han ◽  
Meiying Wang ◽  
Wenchao Li ◽  
Mingxing An ◽  
Hongzheng Fu
Keyword(s):  
Uric Acid ◽  
Drug Loading ◽  
Gouty Arthritis ◽  
The Body ◽  
Key Points ◽  
Uric Acid Nephropathy ◽  
Charged Carrier ◽  
Dual Drug

Uric acid is the final product of purine metabolism, and excessive serum uric acid can cause gouty arthritis and uric acid nephropathy. Therefore, lowering the uric acid level and alleviating inflammation in the body are the key points to treating these diseases. A stable nanosuspension of peptide BmK9 was prepared by the precipitation-ultrasonication method. By combining uricase on the surface of a positively charged carrier, a complex consisting of neutral rod-shaped BmK9 and uricase nanoparticles (Nplex) was formed to achieve the delivery of BmK9 and uricase, respectively. The formulation of Nplex has a diameter of 180 nm and drug loading up to 200%, which releases BmK9 and uricase slowly and steadily in drug release tests in vitro. There was significantly improved pharmacokinetic behavior of the two drugs because Nplex prolonged the half-life and increased tissue accumulation. Histological assessments showed that the dual drug Nplex can reduce the inflammation response in acute gouty arthritis and chronic uric acid nephropathy in vivo. In the macrophage system, there was lower toxicity and increased beneficial effect on inflammation with Nplex than free BmK9 or uricase. Collectively, this novel formulation provides a dual drug delivery system that can treat gouty arthritis and uric acid nephropathy.

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

2022 ◽  
pp. 1-9
Author(s):  
Hiroshi Nozaki ◽  
Yoshihiro Tange ◽  
Yoji Inada ◽  
Takashi Uchino ◽  
Nakanobu Azuma
Keyword(s):  
Sodium Hypochlorite ◽  
Peracetic Acid ◽  
In Vitro Study ◽  
Dialysis Fluid ◽  
High Concentration ◽  
Membrane Pores ◽  
Polyether Sulfone ◽  
Repeated Use ◽  
High Concentrations

<b><i>Introduction:</i></b> 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. <b><i>Methods:</i></b> 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. <b><i>Results:</i></b> 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. <b><i>Conclusion:</i></b> 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.

scholarly journals Aktivitas Penghambatan Xantin Oksidase pada Ekstrak Daun Sirih Hitam (Piper sp)

2016 ◽  
Vol 3 ◽  
pp. 160-163
Author(s):  
Muhammad Amir Masruhim ◽  
Wisnu Cahyo Prabowo ◽  
Dita Paramitha
Keyword(s):  
Uric Acid ◽  
Xanthine Oxidase ◽  
Inhibitory Activity ◽  
Ethanol Extract ◽  
Betel Leaf ◽  
Activity Test ◽  
Ic50 Values ◽  
One Way Anova

Hyperuricemia is a condition in which increased levels of uric acid in the blood. Xanthine oxidase role in the oxidation of hypoxanthine and xanthine to uric acid. One treatment of hyperuricemia is inhibiting xanthine oxidase in the process of formation of uric acid. The purpose of this study to determine the inhibitory activity of xanthine oxidase in the ethanol extract of black betel leaf (Piper sp). Xanthine oxidase inhibitory activity test using UV-Vis spectrophotometry in vitro with a concentration of 5 ppm, 10 ppm and 20 ppm. The data obtained were analyzed using one-way ANOVA. The result is the ethanol extract of black betel leaf has a different activity significantly and IC50 values obtained is 65.96 ppm.

scholarly journals Biochemical Interactions Between Polymeric Resins Used for Occlusal Splints and Saliva A pilot study comparing the CAD/CAM technology and the conventional approach

2019 ◽  
Vol 56 (2) ◽  
pp. 409-412 ◽  
Author(s):  
Marina Melescanu-Imre ◽  
Mihaela Pantea ◽  
Alexandra Totan ◽  
Ana Maria Cristina Tancu ◽  
Maria Greabu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Uric Acid ◽  
In Vitro Study ◽  
Acrylic Resin ◽  
Occlusal Splints ◽  
Oral Environment ◽  
Cad Cam ◽  
3D Printed ◽  
Polymeric Resins

The CAD/CAM technology has been successfully integrated in clinical and laboratory aspects of dental medicine. The present in vitro study focuses on the biochemical interactions between saliva and three types of polymeric resins for occlusal splints. Dental material samples were produced from 3D printed, milled and self-cured resins and were incubated with saliva samples from 20 healthy volunteers. The results showed that the 3D printed and milled polymeric resins did not produce any significant changes in oxidative stress parameters (uric acid, TAC, GGT, OXSR-1) or inflammatory markers (IL-2, IL-6). On the other hand, the self-cured acrylic resin produced a significant decrease in the salivary TAC and uric acid, the most important antioxidants in saliva, affecting the capacity of saliva to protect the oral environment against oxidative stress.

scholarly journals IR-Photometry Method for Measuring Glucose Concentration in Peritoneal Dialysis Fluid

2021 ◽  
Vol 24 (4) ◽  
pp. 68-78
Author(s):  
N. M. Zhilo ◽  
M. O. Mikhailov ◽  
E. L. Litinskaia ◽  
K. V. Pozhar
Keyword(s):  
Peritoneal Dialysis ◽  
Optical System ◽  
Glucose Concentration ◽  
Experimental Studies ◽  
The Body ◽  
Artificial Kidney ◽  
Dialysis Fluid ◽  
Glucose Content ◽  
Peritoneal Dialysis Fluid ◽  
Dialysate Solution

Introduction. The transition of glucose into the blood during automated peritoneal dialysis with regeneration of the dialysis fluid leads to a decreased removal of excess fluid from the body and corresponding violations of the water-salt balance.Aim. To consider a system for automatically maintaining the concentration of glucose in the dialysate solution, which provides effective ultrafiltration, as well as to propose a non-contact photometric feedback sensor.Materials and methods. The sensor is an optical system of an IR laser diode with a power of 30 mW and a wavelength of 1600 nm, a photodiode and a quartz tube, through which the test solution circulates. The sensor measures the attenuation of the radiation passing through the solution in a pulsed mode and calculates the glucose concentration. The selected combination of digital filters provides compensation for the noise of the optical system. Experimental studies of the efficiency of the sensor were carried out on peritoneal dialysis solutions with various concentrations of urea, creatinine, uric acid and glucose. At the beginning of the experiments, the sensor was calibrated in a pure solution.Results. It was shown that the developed sensor makes it possible to measure the concentration of glucose in a solution for peritoneal dialysis in the range of 42…220 mmol / l with a relative error of about 15%. The time of one measurement is about 1 minute, which makes it possible to obtain up-to-date information on the current concentration of the solution.Conclusion. This combination of characteristics will allow the sensor to be used in artificial kidney wearable devices for assessing the glucose content in the solution, calculating the time to change the solution and as a feedback sensor in a system for maintaining the concentration of the osmotic agent.

Sign in / Sign up

Export Citation Format

Share Document