Air Pollutants ; analysis ; Chromatography, High Pressure Liquid ; methods ; Urea ; analysis ; Workplace

In this paper we reviewed the formulae and analyzed the factors which modified the relationship and estimate the time of death as precise as possible by potassium concentration in vitreous humor. The extra factors including numbers of the cases, cause of death, different eye of both, the urea or/and creatinine in vitreous humor, environmental temperature, sampling techniques, experimental and analytical method were also mentioned.
Aqueous Humor/chemistry* ; Creatinine/analysis* ; Forensic Medicine ; Humans ; Linear Models ; Postmortem Changes ; Potassium/analysis* ; Time Factors ; Urea/analysis*

The ability to use dry blood spots (DBSs) on filter paper for the analysis of urea levels could be an important diagnostic tool for areas that have limited access to laboratory facilities. We developed a method for the extraction and quantification of urea from DBSs that were stored on 3M Whatman filter paper and investigated the effect of long-term storage on the level of urea in DBSs. DBSs of 4.5 mm in diameter were used for our assay, and we determined the urea levels in blood using a commercially available enzymatic kit (UV GLDH-method; Randox laboratories Ltd., UK). The DBSs on filter discs were stored at 4degrees C or at 37degrees C for 120 days. The mean intra- and inter-assay coefficient of variance for our method of urea extraction from dried blood was 4.2% and 6.3%, respectively. We collected 75 fresh blood samples and compared the urea content of each fresh sample with the urea content of DBSs taken from corresponding fresh blood samples. Regression analysis reported a regression coefficient (r) value of 0.97 and a recovery of urea from dried spots was 102.2%. Urea concentrations in DBSs were stable for up to 120 and 90 days when stored at 4degrees C and 37degrees C, respectively. Our results show that urea can be stored and quantitatively recovered from small volumes of blood that was collected on filter paper.
*Dried Blood Spot Testing ; Filtration ; Humans ; Paper ; Regression Analysis ; Temperature ; Urea/*blood

The ability to use dry blood spots (DBSs) on filter paper for the analysis of urea levels could be an important diagnostic tool for areas that have limited access to laboratory facilities. We developed a method for the extraction and quantification of urea from DBSs that were stored on 3M Whatman filter paper and investigated the effect of long-term storage on the level of urea in DBSs. DBSs of 4.5 mm in diameter were used for our assay, and we determined the urea levels in blood using a commercially available enzymatic kit (UV GLDH-method; Randox laboratories Ltd., UK). The DBSs on filter discs were stored at 4degrees C or at 37degrees C for 120 days. The mean intra- and inter-assay coefficient of variance for our method of urea extraction from dried blood was 4.2% and 6.3%, respectively. We collected 75 fresh blood samples and compared the urea content of each fresh sample with the urea content of DBSs taken from corresponding fresh blood samples. Regression analysis reported a regression coefficient (r) value of 0.97 and a recovery of urea from dried spots was 102.2%. Urea concentrations in DBSs were stable for up to 120 and 90 days when stored at 4degrees C and 37degrees C, respectively. Our results show that urea can be stored and quantitatively recovered from small volumes of blood that was collected on filter paper.
*Dried Blood Spot Testing ; Filtration ; Humans ; Paper ; Regression Analysis ; Temperature ; Urea/*blood

BACKGROUND/AIMS: Decreasing trend of eradication rate of H. pylori using first-line triple regimens (proton pump inhibitor, amoxicillin, clarithromycin) has been issued. Longer therapies may become more popular if there are better results. Recent eradication rate should be examined and proper recommendation should be timely done according to the result. METHODS: We examined recent eradication rates of first-line triple regimens and compared eradication rate according to the duration of this first-line therapy for H. pylori infection. The 976 patients received first-line triple therapy at the single center from November, 2005 to October, 2009 were retrospectively analyzed. Urea breath test was done at four to six weeks after completion of eradication therapy. RESULTS: Overall eradication rate of triple regimen by intention to treat analysis was 80.4% (785/976). One week eradication rate has decreasing trend and below 73.3% during recent 2 years. Eradication rate in 2 weeks group (83.3%, 165/198) was significantly higher than 1 week group (73.3%, 198/270) from November, 2007 to October, 2009 (p<0.01). CONCLUSIONS: Our results showed that 2 weeks triple regimen should be preferred as first-line therapy for H. pylori eradication.
Amoxicillin ; Breath Tests ; Helicobacter pylori ; Humans ; Intention to Treat Analysis ; Retrospective Studies ; Urea

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

OBJECTIVE: To study the clinical effect and complications of continuous blood purification (CBP) in the treatment of multiple organ dysfunction syndrome (MODS) in neonates. METHODS: A retrospective analysis was performed for the clinical data of 21 neonates with MODS who were admitted to the neonatal intensive care unit from November 2015 to April 2019 and were treated with CBP. Clinical indices were observed before treatment, at 6, 12, 24, and 36 hours of CBP treatment, and at the end of treatment to evaluate the clinical effect and safety of CBP treatment. RESULTS: Among the 21 neonates with MODS undergoing CBP, 17 (81%) had response to treatment. The neonates with response to CBP treatment had a significant improvement in oxygenation index at 6 hours of treatment, a significant increase in urine volume at 24 hours of treatment, a stable blood pressure within the normal range at 24 hours of treatment, and significant reductions in the doses of the vasoactive agents epinephrine and dopamine at 6 hours of treatment (P<0.05), as well as a significant reduction in serum K+ level at 6 hours of treatment, a significant improvement in blood pH at 12 hours of treatment, and significant reductions in blood lactic acid, blood creatinine, and blood urea nitrogen at 12 hours of treatment (P<0.05). Among the 21 neonates during CBP treatment, 6 experienced thrombocytopenia, 1 had membrane occlusion, and 1 experienced bleeding, and no hypothermia, hypotension, or infection was observed. CONCLUSIONS CBP is a safe, feasible, and effective method for the treatment of MODS in neonates, with few complications.
Blood Gas Analysis ; Blood Urea Nitrogen ; Hemofiltration ; Humans ; Infant, Newborn ; Multiple Organ Failure ; Retrospective Studies

OBJECTIVE: To explore the changes and clinical significance of saliva urea, creatinine (Cr), uric acid (UA) in both healthy people and chronic kidney disease (CKD) patients, and to provide a noninvasive, quick, accurate and reliable test to diagnose kindey disease. METHODS: Urea, Cr and UA in the saliva and serum collected from both healthy people and the CKD patients were measured by biochemical analyzer. We calculated the correlation coefficient of Urea, Cr and UA between the saliva and serum, compared the levels of saliva Urea, Cr and UA among CKD patients in different periods, drew the receiver operation characteristic (ROC) curve and analyzed the sensitivity and specificity of saliva Urea, Cr and UA to predict CKD patients in various periods. RESULTS: The concentrations of Urea, Cr and UA in both the saliva and the serum were positively correlated in healthy individuals and CKD patients (r = 0.918, 0.932, 0.840 and 0.984, 0.971, 0.920). The levels of saliva Urea, Cr and UA in the CKD patients were significantly higher than those of healthy people (P<0.05). Saliva Urea, Cr and UA concentrations of middle and late stage CKD patients were obviously higher than those of healthy people and early stage CKD patients (P<0.05). Areas under the curve (AUC) of the ROC of Urea, Cr and UA to diagnose diverse periods of CKD were 0.898, 0.897 and 0.848. The sensitivity was 0.806, 0.776 and 0.704; and the specificity was 0.968, 0.989 and 0.871. CONCLUSION The levels of Urea, Cr and UA between the saliva and the serum are closely related. The concentration of saliva Urea, Cr and UA can reflect the renal damage, monitor kidney function of the CKD patients, and help diagnose middle to late stage CKD patients. It is a simple, nonivasive and quick method.
Adolescent ; Adult ; Aged ; Case-Control Studies ; Creatinine ; analysis ; Female ; Humans ; Male ; Middle Aged ; Renal Insufficiency, Chronic ; metabolism ; Saliva ; chemistry ; Urea ; analysis ; Uric Acid ; analysis ; Young Adult

Through the present delta value check used in quality control programs is a powerful tool for detecting random errors in clinical chemistry analysis, it has some problems, such as missed true errors and delays in reporting time, because it also has the potential of showing erroneous positive results. Recently, new calculation methods for delta check with delta difference, delta percent change, rate difference, and rate percent change have been suggested by Lacher and Connelly (Clin Chem 34:1966-1970, 1988). Based on this new delta check method, we made the new criteria of which calculation method is applied to the clinical chemistry tests, i.e., the differential application of rate and delta check, and selectively applied the new method to 17 chemistry tests in order to solve the above problems. The applied criteria were the time dependence of the test item and the coefficient of variation of the absolute delta difference. Calcium, inorganic phosphorus, total protein, albumin, sodium, potassium, and chloride were classified as delta difference calculation method group; glucose and cholesterol as delta percent change group; creatinine, total and direct bilirubin as rate difference group; and urea nitrogen, uric acid, ALP, ALT, and AST as rate percent change group. With the previous criteria by Whitehurst et al. (Clin Chem 221:87-92) for 5045 specimens, the check-out rate was 47.8% (2,411 out of 5,045), and the positive predictive value was 0.41% (10 out of 2,411). For the new criteria, the check-out rate was 12.7% (621 out of 5,045), and the positive predictive value was 1.8% (nine out of 621).(ABSTRACT TRUNCATED AT 250 WORDS)
Albumins/analysis ; Bilirubin/analysis ; Calcium/analysis ; Chemistry, Clinical/methods/*standards ; Clinical Laboratory Information Systems/*standards ; Creatine/analysis ; Glucose/analysis ; Phosphorus/analysis ; Quality Control ; Reference Values ; *Sensitivity and Specificity ; Specimen Handling ; Urea/analysis ; Work Simplification

OBJECTIVEThe influence on the urea inclusion compound under different conditions (allocated proportion, time of inclusion, temperature of inclusion) were studied through the orthogonal test, and theoretical reference of urea inclusion process for further optimization wound be offered.

METHODThe orthogonal experiment was adopted, and microscope was used to observe the shape, aperture size of the urea inclusion compound under different technological parameters, the GC was employed to inspect the purity of GLA.

RESULTThe results indicated that the ratio of fatty acids and urea, inclusion of temperature, time of inclusion had great effect on urea inclusion compound. The three factors and its interactions significantly affected the purity of GLA. The results also showed that the best process was that the ratio of fatty acids and urea was 1 : 3, temperature of inclusion was--15 degrees C, time of inclusion was 24 h.

CONCLUSIONUnder the best condition, the purity of GLA reach up to 95.575 9%; and it is feasible to observe the shape and the amount of the urea inclusion compound to reflect and guide the urea inclusion technology.

Oenothera biennis ; chemistry ; Plant Oils ; chemistry ; Technology, Pharmaceutical ; methods ; Temperature ; Urea ; chemistry ; gamma-Linolenic Acid ; analysis ; isolation & purification