Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:6.3.4.6 (urease)
 7,490 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Wearable, 24 hrs per day, 7 days per week artificial kidneys are being developed. Patients will benefit from more even control of physiologic parameters than can be obtained with conventional intermittent dialysis. Improvement in economic and social circumstances will result. Both hemodialysis and peritoneal dialysis techniques are being miniaturized. Small REDY cartridges containing urease, zirconium phosphate, hydrouse zirconium oxide and activated carbon are being utilized to regenerate dialysate. Hemodialyzers will be worn on the forearm and include long, wide, low resistance series blood flow paths to reduce the potential for thrombosis. Peritoneal effluent is regenerated and filtered by the sorbent cartridge and automatically cycled back into the peritoneal cavity.
J Dial 1977
PMID:In search of a 24 hours per day artificial kidney. 60 88

This report describes the results obtained with a combination of acetohydroxamic acid (AHA) and antibacterial agents in 13 patients with recurrent struvite stones complicated by refractory infections with urease-producing bacteria. Intravenous antibiotic pulses plus oral AHA achieved urine sterilisation in all. Then oral chemotherapy plus AHA was given for a mean period of 10.8 +/- 5.4 months. In four patients, the urine remained sterile, but in all the patients urinary pH remained below 6.4 and urinary NH4+ below 40 mg/dl. Despite the persistence of urea-splitting bacteria, the radiographic data showed an arrest of stone growth during the first year of treatment.
Proc Eur Dial Transplant Assoc 1983
PMID:Acetohydroxamate in struvite stones: in vivo study. 665 71

The prevalence of Helicobacter pylori (H. pylori) was investigated in 164 consecutive patients with different degrees of renal function; group I (normal renal function) n = 84, group II (chronic renal failure, CLCR > or = 5 < 90 ml/min) n = 45, group III (haemodialysis therapy) n = 35, to test the hypothesis that the resulting different concentrations of urea in the gastric juice would have an influence on the colonization of the gastric mucosa by these urea-splitting bacteria. As every individual method for the detection of H. pylori shows disadvantages, the results of the detection methods used (urease test, Warthin-Starry stain, bacterial cultivation, direct examination of the processed sample by phase-contrast microscopy) were combined in a cumulative evaluation. These calculated cumulative indices for the antrum and corpus showed no statistically significant differences between the studied groups. The prevalence of H. pylori ranged from 34 to 54%. The histopathological findings were similar in all groups. In spite of the fact that patients with renal dysfunction had significantly higher levels of serum gastrin (P < 0.05), there was no influence on the gastric juice pH value. The relationship between the cumulative index and ammonia concentration in gastric juice was found to be linear (P < 0.05). The higher urea levels in the blood and gastric juice of patients with renal failure do not seem to be a risk factor for infection with H. pylori.
Nephrol Dial Transplant 1993
PMID:Prevalence of Helicobacter pylori in patients with chronic renal failure. 839 2

In this study, the response to triple treatment with omeprazole, amoxicillin, and clarithromycin was investigated in continuous ambulatory peritoneal dialysis (CAPD) patients with Helicobacter pylori (Hp) infections. The study enrolled 20 CAPD patients (11 male, 9 female) who had dyspeptic complaints. The mean age of the patients was 46 (range: 21-65). The study also enrolled, as a control group, 124 patients (66 male, 58 female) who had no systemic disease, but who had upper gastrointestinal endoscopy for dyspeptic complaints. The mean age of the patients in the control group was 47 years (range: 20-74 years). Upper gastrointestinal endoscopy, rapid urease test (CLO test), and direct histologic examination were carried out to detect Hp infection. Hp infection was detected in 10 cases (50%) in the CAPD group and in 53 cases (43%) in the control group. In both groups, patients with Hp infection received the triple treatment of omeprazole 20 mg twice daily for 30 days, amoxicillin 500 mg thrice daily for 15 days, and clarithromycin 500 mg thrice daily for 15 days. To assess response to treatment, upper gastrointestinal endoscopy, CLO test, and direct histologic examination were repeated 3 months after initiation of the treatment. Hp was eradicated in all of the 11 CAPD patients (100%), and in 42 of the control patients (92%). Our results suggest that the triple treatment with omeprazole, amoxicillin, and clarithromycin for Hp infection is as effective in CAPD patients as in the normal population.
Adv Perit Dial 1999
PMID:Response to triple treatment with omeprazole, amoxicillin, and clarithromycin for Helicobacter pylori infections in continuous ambulatory peritoneal dialysis patients. 1068 76

The influence of dialysis prescription on outcome is well established, and currently the amount of dialysis prescribed is based on small molecular weight toxin removal as represented by the clearance of urea. The "normalized dose of dialysis" (Kt/V(urea)) concept is well established. Most techniques for dialysis quantification require that blood samples be taken at the beginning and after the completion of dialysis. The postdialysis sample, however, gives cause for concern because of the "rebound phenomenon" due to nonuniform distribution of urea among body compartments. Blood samples give "indirect" measures of dialysis quantification. Thus direct urea concentration measurements in dialysate may be superior in urea kinetic modeling and these may be made "real time" during dialysis. It is with real-time monitoring that future advances in dialysis quantification will take place. These will be of two types. The first will analyze blood water or dialysate samples for urea content multiple times throughout the treatment; the second will assess the on-line clearance of urea using surrogate molecules such as sodium chloride, the clearance being determined by conductivity measurements. On-line urea monitoring is based on the action of urease on urea in a water solution and measurement of the resultant ammonium ions, which are measured directly by a specific electrode or indirectly by conductivity changes. Differences in blood-side versus dialysate-side urea monitors exist which reflect the parameters they can provide, but with both, the standard urea kinetic measurements of Kt/V and nPCR (nPNA) are easily obtainable. A range of additional parameters can be derived from dialysate-side monitoring such as "whole-body Kt/V," "pretreatment urea mass" and "whole-body urea clearance," which are worthy of future studies to determine their roles in adequacy assessment. Conductivity clearance measurements are made by examining the conductivity differences between dialysate inlet and outlet measured at two different dialysate inlet concentrations. This allows for the calculation of the electrolyte (ionic) dialysance, which is equal to the "effective" urea clearance, that is, the clearance that takes into account recirculation effects that reduce hemodialysis efficiency. The continuous reading of effective ionic clearance will allow an average value for K to be obtained for that dialysis, and hence the parameter K x t as an indication of dialysis dose is easily and accurately obtained for every treatment. The conductivity technology is cheap and rugged, and thus expanded use can be expected. Urea monitors have an inherent cost and require maintenance, and perhaps will remain researchers' tools for the present. The methodologies can complement each other; the addition of an accurate and independent value for K to dialysate based urea monitoring is like having simultaneous blood- and dialysate-side monitoring, and allows further increase in measurable parameters.
Semin Dial
PMID:Future directions in dialysis quantification. 1148 7

To regenerate dialysate in hemodialysis for kidney failure, it is necessary to remove all uremic toxins, avoid excessive removal of various electrolytes, and supply beneficial components such as bicarbonate. Surprisingly, a simple collection of components can accomplish this task very well: charcoal, urease, cation exchanger, and anion exchanger. From the early days of use of the Redy system and the Sorb cartridge, improvements have been made both in machine design and column chemical function. This article describes the chemical function of the Sorb cartridge, recent improvements, and the methods to predict the chemical function of the column. It also describes a number of improvements made in dialysis machines using sorbent regeneration of the dialysate. Some ongoing improvements in sorbent chemistry are also described.
Semin Dial
PMID:Sorbents in treatment of uremia: a short history and a great future. 2001 31

Peritoneal dialysis can be considered a "wearable" dialysis therapy. However, patients typically require 3 or 4 daily exchanges, each taking 20-40 minutes and potentially increasing the risk of infection by repeated disconnection and reconnection. Although peritoneal dialysis cyclers allow patients to be "free" from their machine for 13-15 hours, they similarly need a supply of fresh dialysate. Several groups have therefore explored the possibility of trying to minimize dialysate exchanges by recycling dialysate. However, that approach introduces not only a series of challenges, including regeneration of the spent dialysate, maintenance of acid-base and electrolyte balance and adequate ultrafiltration, but also new hurdles to be overcome, including monitoring the sorbents to determine when capacity is exceeded. The proposed Vicenza Wearable Artificial Kidney system consists of a continuous-flow peritoneal dialysis system that combines sorbents in series and urease to regenerate dialysate during the day, and a 7.5% icodextrin exchange overnight.
Adv Perit Dial 2012
PMID:Portable or wearable peritoneal devices--the next step forward for peritoneal dialysis? 2331 Dec 23

Chronic kidney disease (CKD) has long been known to cause significant gastrointestinal and colonic pathology. Recent advances in understanding of the role of colonic bacterial microbiome and its function and composition in health and disease have revealed previously unappreciated effects of CKD-associated colonic pathology on the development of uremic complications. CKD can result in profound changes in the microbiome composition and biosynthetic pattern, and the structure and function of the colon. Increases in bacteria that produce urease, uricase, p-cresol- and indole-forming enzymes and the depletion of bacteria that possess short chain fatty acid forming enzymes have been described in human and animal models. Disruption of the colonic epithelial tight junction in different animal models of CKD has been reported and is largely due to the conversion of luminal urea to ammonia by urease possessing bacteria. Together, these changes contribute to the pathogenesis of systemic inflammation and uremic toxicity by allowing the translocation of endotoxin and microbial fragments into the circulation. Additionally, colonic bacteria are the main source of several well-known pro-inflammatory uremic toxins such as indoxyl sulfate, P-cresol sulfate. This review is intended to provide an overview of the effects of CKD on the colonic microbiome and the intestinal epithelial barrier structure and function and their role in the pathogenesis the systemic inflammation and uremic toxicity.
Semin Dial
PMID:The Chronic Kidney Disease - Colonic Axis. 2585 16

The normal gut microbiome modulates host enterocyte metabolism and shapes local and systemic immunity. Accumulation of urea and other waste products in chronic kidney disease induces gut dysbiosis and intestinal wall inflammation (leaky gut). There are decreased numbers of bacteria that generate short-chain fatty acids, which are an important nutrient source for host enterocytes and also contribute to regulation of the host immune system. Anaerobic proteolytic bacteria that express urease, uricase and indole and p-cresol enzymes, such as Enterobacteria and Enterococci, are increased. Microbial-derived uremic toxins such as indoxyl sulfate and trimethylamine N-oxide contribute to the pathophysiology of immune-related kidney diseases such as diabetic nephropathy, lupus nephritis and immunoglobulin A (IgA) nephropathy. Animal and clinical studies suggest potential benefits of dietary and probiotic interventions in slowing the progression of immune-related kidney diseases.
Nephrol Dial Transplant 2020 May 21
PMID:The consequences of altered microbiota in immune-related chronic kidney disease. 3243 54