Urea clearance index (KT/Vurea) and creatinine clearance weekly (Ccr) are main indexes to evaluate dialysis adequacy. In order to discuss whether they are suitable to evaluate peritoneal dialysis adequacy, we applied trans-peritoneum transport kinetic model and explored the transport characteristics of fluid and various solutes. We found that: (1) There was no specific relationship among the removal of solutes with different molecular weights; (2) There was significant difference between urea removal and fluid and sodium removal. Our results suggest that urea and creatinine removal do not represent other solutes and fluid removal. KT/Vurea and Ccr may thus not suit to be used alone to evaluate peritoneal dialysis adequacy.
Biomarkers ; metabolism ; Blood Urea Nitrogen ; Creatinine ; metabolism ; Humans ; Peritoneal Dialysis, Continuous Ambulatory ; Urea ; metabolism

Biotin-deficient rats were raised on a purified ration containing raw egg white plus avidin. Urea synthesis and excretion were compared between the biotin-deficient and the pair-fed control rats. 24hrurinary urea excretion and the specific activities of carbamylphosphate synthetase, ornithine transcarbamylase, and arginase in the liver mitochondria fraction were no different between these two groups. The net urea production in the liver slice and in the isolated perfused liver of the biotin-deficient rats was similar to that of the pair-fed control. Thus the conclusion must be that biotin is not in urea in mea biosynthesis in the rat.
Animal ; Avitaminosis/metabolism ; Biotin* ; Liver/metabolism* ; Rats ; Urea/biosynthesis* ; MH - ; Substances: ; Urea ; Biotin

Primary human hepatocytes (PHH) are the gold standard of in vitro human liver model for drug screening. However, a problem of culturing PHH in vitro is the rapid decline of cytochrome P450 (CYP450) activity, which plays an important role in drug metabolism. In this study, thermo-responsive culture dishes were used to explore the conditions for murine embryonic 3T3-J2 fibroblasts to form cell sheet. Based on the cell sheet engineering technology, a three-dimensional (3D) "sandwich" co-culture system of 3T3-J2 cell sheet/PHH/collagen gel was constructed. The tissue structure and protein expression of the model section were observed by hematoxylin eosin staining and immunofluorescence staining respectively. Phenacetin and bupropion were used as substrates to determine the activity of CYP450. The contents of albumin and urea in the system were determined by enzyme linked immunosorbent assay (ELISA). The results showed that the complete 3T3-J2 cell sheet could be obtained when the cell seeding density was 1.5×10⁶ /dish (35 mm dish) and the incubation time at low temperature was 60 min. Through cell sheet stacking, a 3D in vitro liver model was developed. Compared with the two-dimensional (2D) model, in the 3D model, the cell-cell and cell-matrix connections were tighter, the activities of cytochrome P450 CYP1A2 and cytochrome P450 CYP2B6 were significantly increased, and the secretion levels of albumin and urea were increased. These indexes could be maintained stably for 21 d. Therefore, cell sheet stacking is helpful to improve the level of liver function of 3D liver model. This model is expected to be used to predict the metabolism of low-clearance drugs in preclinical, which is of great significance for drug evaluation and other studies.
Albumins/metabolism* ; Animals ; Cytochrome P-450 Enzyme System/metabolism* ; Hepatocytes/metabolism* ; Humans ; Liver ; Mice ; Urea/metabolism*

Aquaporin-9 (AQP9) is a membrane-span transport protein expressed in the liver. It is located in the cytoplasm membrane of hepatic cells. In addition to water, it is also permeable to glycerol, urea, and other small solutes. Several evidences have revealed that AQP9 is involved in multiple physiological and pathological process of the liver. This paper summarized the expression of AQP9 in the liver and the effect on the physiological and pathological processes of the liver. AQP9 may be defined as a novel target for diagnosis and treatment of hepatic diseases.
Aquaporins ; metabolism ; Cell Membrane ; metabolism ; Glycerol ; Hepatocytes ; metabolism ; Humans ; Liver ; metabolism ; Urea

The effect of alloxan-diabetic rat fed with normal, high fat, low protein and high protein diets on the rate of urea production and the activities of enzymes associated with the urea cycle (ornithine transcarbamoylase, E.C. 2.1.3.3, OTC; arginase, E.C. 3.5.5.1) have been studied in intact and isolated perfused liver. The amount of urea excretion was the highest in the high protein diet group. When each diet group was treated with alloxan, total urea excretion showed little differences between each diet group and its corresponding control group with the exception being in the normal diet group. However, the enzyme activity of OTC was increased significantly by alloxan treatment in low and high protein diet groups as compared to corresponding control groups. Similar results were obtained in arginase activity, although the magnitude of the change was less marked. In liver perfusion experiments on rats treated with alloxan, the amount of urea production and changes in OTC and arginase activity were very similar with those in the intact liver. These results suggest that alloxan treatment in normal diet group causes an increase in urea excretion both in intact and perfused liver regardless of changes in enzyme activities and total urea excretion, and enzyme activities are affected by changes in dietary components but the changes of enzyme activities may not correlate with total urea excretion.
Alloxan ; Animal ; Diabetes Mellitus, Experimental/metabolism* ; Dietary Fats/pharmacology* ; Dietary Proteins/pharmacology* ; In Vitro ; Liver/metabolism* ; Male ; Perfusion ; Rats ; Urea/metabolism* ; Urea/urine

Ethyl carbamate (EC) as a potential carcinogen commonly exists in traditional fermented foods. It is important eliminate urea that is the precursors of EC in many fermented foods, including Chinese Rice wine. On the basis of achieving high-level overexpression of food-grade ethanol-resistant acid urease, we studied the hydrolysis of urea and EC with the recombinant acid urease. Recombinant acid urease showed degraded urea in both the simulated system with ethanol and Chinese Rice wine (60 mg/L of urea was completely degraded within 25 h), indicating that the recombinant enzyme is suitable for the elimination of urea in Chinese Rice wine. Although recombinant acid urease also has degradation catalytic activity on EC, no obvious degradation of EC was observed. Further investigation results showed that the Km value for urea and EC of the recombinant acid urease was 0.7147 mmol/L and 41.32 mmol/L, respectively. The results provided theoretical foundation for realizing simultaneous degradation of urea and EC.
Oryza ; Recombinant Proteins ; metabolism ; Urea ; chemistry ; Urease ; metabolism ; Urethane ; chemistry ; Wine ; analysis

Against the large number of assessment indices to the adequacy peritoneal dialysis and incompatibility of some indices, an intelligent assessment approach to the peritoneal dialysis adequacy based on MART2 (modified from ART2) network is proposed. After non-dimension and weighting preconditioning, the assessment indices were put to MART2 and sorted into many clusters. The center-of-gravity of each cluster was identified as adequacy or inadequacy according to the assessment criteria of dialysis adequacy, and the adequacy of each cluster could be determined by the adequacy of corresponding center-of-gravity when the network threshold was high. Finally, the peritoneal dialysis adequacy of each patient could be judged according to the adequacy of cluster to which the patients' indices belong. Experimental results demounstrate its effectiveness.
Creatinine ; metabolism ; Guideline Adherence ; Humans ; Kidney Failure, Chronic ; metabolism ; therapy ; Peritoneal Dialysis ; instrumentation ; standards ; Quality Assurance, Health Care ; Urea ; metabolism

The present study was aimed to investigate whether Gasdermin D (GSDMD)-mediated pyroptosis participated in lipopolysaccharide (LPS)-induced sepsis-associated acute kidney injury (AKI), and to explore the role of caspase-1 and caspase-11 pyroptosis pathways in this process. The mice were divided into four groups: wild type (WT), WT-LPS, GSDMD knockout (KO) and KO-LPS. The sepsis-associated AKI was induced by intraperitoneal injection of LPS (40 mg/kg). Blood samples were taken to determine the concentration of creatinine and urea nitrogen. The pathological changes of renal tissue were observed via HE staining. Western blot was used to investigate the expression of pyroptosis-associated proteins. The results showed that the concentrations of serum creatinine and urea nitrogen in the WT-LPS group were significantly increased, compared with those in the WT group (P < 0.01); whereas serum creatinine and urea nitrogen in the KO-LPS group were significantly decreased, compared with those in the WT-LPS group (P < 0.01). HE staining results showed that LPS-induced renal tubular dilatation was mitigated in GSDMD KO mice. Western blot results showed that LPS up-regulated the protein expression levels of interleukin-1β (IL-1β), GSDMD and GSDMD-N in WT mice. GSDMD KO significantly down-regulated the protein levels of IL-1β, caspase-11, pro-caspase-1, caspase-1(p22) induced by LPS. These results suggest that GSDMD-mediated pyroptosis is involved in LPS-induced sepsis-associated AKI. Caspase-1 and caspase-11 may be involved in GSDMD cleavage.
Animals ; Mice ; Acute Kidney Injury ; Caspase 1 ; Caspases/metabolism* ; Creatinine ; Lipopolysaccharides ; Mice, Knockout ; Nitrogen ; Sepsis ; Urea ; Gasdermins/metabolism*

OBJECTIVETo observe the biochemical characters and antibiotic susceptibility of isolated Staphylococcus aureus (S. auerus) strains against some conventional and traditional antibiotics.

METHODSThirty post operative pathogenic isolated S. aureus strains were used in this study. Bacterial culture was done in Mueller-Hinton broth at 37 °C. Characters of these strains were determined by traditional biochemical tests such as hydrolysis test of gelatin, urea, galactose, starch and protein, and fermentation of lactose and sucrose. Antibiotic susceptibility were carried out by minimum inhibitory concentration test, minium bactericidal concentration test, disc agar diffusion test and brain heart infusion oxacillin screening agar.

RESULTSFrom this study, it was observed that 100% S. aureus isolates showed positive results in gelatin, urea and galactose hydrolysis test, 50% isolates were positive in starch hydrolysis test, 35% in protein hydrolysis test, 100% isolates in lactose fermenting test, but no isolate was positive in sucrose fermenting test. Antibiotic susceptibility testing suggested that 20% of isolates were resistant to kanamycin and 46.67% were resistant to oxacillin.

CONCLUSIONSThese findings show that all these isolates have gelatin, urea, galactose hydrolysis and lactose fermenting activity. 20% of these isolates were resistant to kanamycin and 46.67% were resistant to oxacillin.

Anti-Bacterial Agents ; pharmacology ; Disk Diffusion Antimicrobial Tests ; Galactose ; metabolism ; Gelatin ; metabolism ; Hydrolysis ; Microbial Sensitivity Tests ; Staphylococcus aureus ; drug effects ; isolation & purification ; metabolism ; Starch ; metabolism ; Urea ; metabolism

BACKGROUND: The time at which renal replacement therapy (RRT) is initiated in patients with end-stage renal disease (ESRD) has a great influence on the prognosis of the patient; however, there are currently no accurate guidelines for the initiation of RRT. Traditionally, nephrologists usually initiate RRT on the basis of the observation of the uremic symptoms and changes in the laboratory parameters, such as the serum creatinine concentration and/or glomerular filtration rate (GFR). DOQI guidelines suggest a weekly Kt/Vurea < 2.0 or an nPNA < 0.8 g/kg/day as objective indices for the initiation of dialysis. Thus, a KP index was formulated (weekly Kt/Vurea+2.5 X nPNA) X (1/2) using the above two clinically useful and objective indices to determine the adeguate time to initiate RRT in patients with ESRD. METHODS: Of 186 patients admitted to the renal unit of Soonchunhyang Bucheon hospital, those with ESRD and a weekly Kt/Vurea below 3.0 were selected. The patients with a weekly Kt/Vurea index between 1.0 and 2.0 were classified into one of two groups; KP index > 2.0 and KP index < 2.0. The groups were compared and analyzed in relation to their renal function, biochemical indices and the numbers of patients per group starting RRT. Further, the correlations between the KP and other indices were analyzed in all the patients. The patients were then further divided into another two groups according to their weekly Kt/Vurea and KP index: group one; between 1.5 and 2.0 and group 2; between 2.0 and 2.5. The numbers of patients per group starting RRT were compared. RESULTS: The KP index < 2.0 group showed significantly lower indices for weekly Kt/Vurea, nPNA and %LBM (%) than those of the KP index > 2.0 group, while there were no significant differences between the groups in the serum albumin concentration, serum creatinine concentration, FFEFBM and RRF. Also, there was a statistically significant higher rate of incidence of patients starting RRT in the KP index < 2.0 group than in the KP index > 2.0 group. There was a significant correlation between the KP and other indices in all patients. When comparing the number of patients starting RRT, the weekly Kt/Vurea index demonstrated no significant differences between the 1.5 < weekly Kt/Vurea < 2.0 and 2.0 < weekly Kt/Vurea < 2.5 groups, but the number of patients starting RRT in the 1.5 < KP index < 2.0 group was significantly higher than that in the 2.0 < KP index < 2.5 group. CONCLUSION: The KP index is considered a clinically useful index in ESRD patients for determining an appropriate time for the initiation of RRT. Also, the timing of the initiation of RRT should be fixed with regard to the various other indices and clinical features for a desirable prognosis of the patients. In addition, further studies will be required to determine accurate guidelines for an appropriate time for RRT initiation.
Adult ; Aged ; Blood Urea Nitrogen ; Creatinine/blood ; Female ; Glomerular Filtration Rate ; Humans ; Kidney/metabolism ; Kidney Failure, Chronic/epidemiology/*metabolism/physiopathology/*therapy ; Korea/epidemiology ; Male ; Middle Aged ; Nutritional Status ; *Renal Dialysis ; Serum Albumin/metabolism ; Severity of Illness Index ; Urea/blood