Simple and Cost-effective "Turn-on" Fluorescence Sensor for the Determination of Xanthine.

A simple and selective 'turn-on' fluorescence sensor have been developed for the determination of xanthine (XA) based on glutathione (GSH) capped copper nanoclusters (CuNCs) as the fluorescent probe. The proposed sensor possess several advantages such as sensitivity, short analysis time and requires no sample pretreatment. The conditions for the performances of the sensor have been optimized and good linear relationship was obtained between concentration and relative fluorescence intensity in the concentration range 9.0[Formula: see text]10-3 M to 8.0[Formula: see text]10-5 M with a detection limit 6.0[Formula: see text]10-6 M. The mechanism behind the fluorescence enhancement may be ascribed to the binding of XA on the surface of GSH CuNCs. The sensor have been successfully applied to determine XA in spiked physiological samples.

A new strategy for improved glutathione production from Saccharomyces cerevisiae: use of cysteine- and glycine-rich chicken feather protein hydrolysate as a new cheap substrate.

BACKGROUND: Glutathione (GSH) is composed of the amino acids glutamic acid, cysteine and glycine. This study investigated the usability of chicken feather protein hydrolysate (chicken feather peptone, CFP) as a substrate for GSH production from Saccharomyces cerevisiae. RESULTS: CFP was found to be rich in ash (36.7 g per 100 g), protein (61.1 g per 100 g) and minerals (S, P, K, Ca, Fe, Na and Mg). It also had high contents of cysteine and glycine. CFP augmented biomass and GSH production by 53 and 115% respectively compared with the control medium. The highest biomass (17.4 g l(-1)) and GSH (271 mg L(-1)) concentrations were attained in CFP medium. The second highest biomass (16.8 g l(-1)) and GSH (255 mg L(-1)) concentrations were obtained in fish peptone medium. It was assumed that the high mineral, cysteine and glycine contents of CFP were related to cell growth and GSH synthesis in S. cerevisiae. CONCLUSION: This is the first report on the effect of cysteine- and glycine-rich protein hydrolysates on GSH production from S. cerevisiae. In this regard, CFP was tested for the first time as a GSH production substrate. As an additional contribution, a new hydrolysis process was developed for the preparation of protein hydrolysates.

A randomized study comparing IGL-1 to the University of Wisconsin preservation solution in liver transplantation.

BACKGROUND: Institut Georges Lopez-1 (IGL-1) is a new preservation solution with lower potassium and lower viscosity than University Wisconsin solution (UW). These characteristics which improve liver preservation lead us to evaluate clinical effects of IGL-1 in a randomized controlled study with UW. MATERIAL/METHODS: From June 2007 to July 2009, after exclusion of partial graft, combined transplantation and fulminant hepatic failure, 140 deceased donor allografts were randomly assigned to IGL-1 (n=48) or UW (n=92) solution. Variables concerning donors and recipients were collected including liver tests (total serum bilirubin, prothrombin time and transaminases) were analyzed until postoperative day 30. Incidences of hepatic artery thrombosis (HAT), primary non function (PNF) and biliary non anastomotic strictures (NAS) were analyzed. The comparative analysis of costs was realized. RESULTS: Donor and recipients characteristics were similar in both groups. Volume of preservation solution utilized for harvesting was identical. Duration of cold ischemia (472±142 vs. 477±122 min), surgery (427±97 vs. 437±94 min) and proportion of extended criteria donor was similar. Postoperative kinetic and level liver tests were similar. Rate of PNF (2% vs. 4%), early retransplantation (6% vs. 7%), incidence of biliary NAS (2% vs. 3%) and HAT (6% vs. 4%) were similar. Mean intensive care unit (ICU) stay was similar (5.6 vs. 6.1 days). However costs related to preservation solution for one liver procurement were 992.0 for IGL-1 vs. 1609.0 Euros for UW. CONCLUSIONS: Results of this randomized study shows that the efficacy and safety of IGL-1 are comparable to those of the reference UW with a lower cost.

Comparative analysis of clinical efficacy and cost between University of Wisconsin solution and histidine-tryptophan-ketoglutarate.

OBJECTIVE: To compare University of Wisconsin solution (Viaspan), the universal standard for organ preservation, with histidine-tryptophan-ketoglutarate solution. An analysis of each solution, in reference to clinical trials with specific organs, is presented and assessed to find the efficacy of each in a clinical environment. Also to view each solution from an economical standpoint, and in the end develop an overall understanding of the key similarities and differences between each solution in order to assess appropriate use of each in a clinical setting. DATA SOURCES: A literature search was conducted by using PubMed, MEDLINE, BIOSIS, Embase, and other online data bases to find the most recent studies of University of Wisconsin and histidine-tryptophan-ketoglutarate solutions. Search terms included University of Wisconsin solution, histidine-tryptophan-ketoglutarate, preservation solution, cost analysis, biliary complication, and other related subjects. STUDY SELECTION: Previous research was selected from the literature search to provide basic information on the 2 solutions and also to provide clinical examples of each solution and the efficacy of each with specific organs. DATA SYNTHESIS: Information and published articles on the 2 solutions were gathered for descriptive and comparative purposes. CONCLUSIONS: The 2 solutions appear equally effective in organ preservation. Each solution has its own organ-specific qualities, and each has different complications. The studies reviewed here indicate that the differences are minor and thus suggest that the 2 solutions are equally acceptable for clinical use. Of the 2 solutions, histidine-tryptophan-ketoglutarate costs less than University of Wisconsin solution.

Effects of Eurocollins solution as aortic flush for the procurement of human pancreas.

BACKGROUND: Belzer solution is considered to be the best preservation media used for pancreas transplantation; however, its high cost accounts for approximately 14.5% of all resources allocated by the Brazilian government toward each pancreatic transplant. The objective of the present study was to test a reduction of Belzer solution during pancreas harvest, thereby lowering procedural cost. METHODS: The patients received pancreas-kidney transplantations during the period from January 2003 to August 2004. Patients were divided into two groups. Patients assigned to Group A (n=30) received only Belzer solution (2 L through the aorta artery), whereas patients in Group B (n=16) were perfused first with 1 L of Eurocollins solution followed by 1 L of Belzer solution. The two groups were assessed for differences in the following clinical parameters: the need for insulin replacement or antifungal and anticytomegalovirus treatment, pancreatitis, acute cellular rejection, graft vascular thrombosis, fistulas, intra-abdominal collection, graft loss, deaths, pancreatic ischemia time, and average hospitalization time. RESULTS: No statistically significant differences were observed in any of the parameters analyzed (P<0.05). The use of Eurocollins solution, followed by Belzer solution during pancreas harvesting, did not result in differences in graft survival or functionality, postsurgical complications, or patient survival and hospitalization time, when compared to the use of Belzer solution alone. CONCLUSIONS: Perfusion with 1 L of Eurocollins solution followed by 1 L of Belzer solution during pancreas harvesting seems to be a simple and efficient alternative for reducing the costs of the harvesting process.

Comparative study on two kidney graft rinsing and preservation solutions in terms of the post-transplantation risk of delayed graft function and cost.

OBJECTIVE: To determine whether Belzer solution (Viaspan, Bristol-Myers Squibb, Brussels, Belgium), which is more expensive than Eurocollins solution, was better at preventing delayed graft function (DGF) and whether it was cost-effective as it could potentially reduce post-transplantation complications. METHOD: The risk of occurrence of complications associated with the use of these two rinsing and preserving solutions was estimated from a survey of 106 patients undergoing renal transplantation between 1 January 1993 and 31 March 1998. Both efficacy and adverse outcomes were recorded along with the costs directly associated with the transplantation procedure in the hospital setting: hospitalization, rinsing and preserving solutions, medical and technical interventions and diagnostic tests. RESULTS: For the 45 kidney grafts rinsed and preserved with Eurocollins (strategy S1: n1 = 45) the cost/graft was estimated at 40 euros. With Viaspan (strategy S2: n2 = 61) the corresponding cost/graft was 424 euros. Logistic regression analysis showed that Viaspan was better than Eurocollins solution (ebeta = 0.437; P = 0.05) in preventing DGF. Overall, S2 was less expensive than S1, from the hospital's perspective. The mean difference per patient was 278 euros, which amounts to a saving of 2% of the total cost per renal transplantation. For rinsing and preserving kidney grafts Belzer solution is therefore preferable to Eurocollins solution.

Corneal endothelial cell protection with a dispersive viscoelastic material and an irrigating solution during phacoemulsification: low-cost versus expensive combination.

PURPOSE: To evaluate the protective effect on corneal endothelial cells of a low-cost and an expensive combination of a dispersive viscoelastic material and an irrigating solution during phacoemulsification. SETTING: Department of Ophthalmology, University of Vienna, Vienna, Austria. METHODS: This prospective randomized examiner- and patient-masked study comprised 90 eyes of 45 consecutive patients with age-related cataract in both eyes. For each patient, the first eye was randomly assigned to receive hydroxypropyl methylcellulose 2% (Ocucoat) and Ringer's solution (low-cost combination) or sodium chondroitin sulfate 4%-sodium hyaluronate 3% (Viscoat) and an enriched balanced salt solution (BSS Plus) (expensive combination) during phacoemulsification. The contralateral eye received the other treatment. Endothelial cell function was evaluated by measuring corneal thickness (CT) using partial coherence interferometry, morphology assessment, and endothelial cell counts. RESULTS: The acute postoperative increase in CT was +9.8 microm in the low-cost group and +10.9 microm in the expensive group; the difference between groups was not significant. After 1 month, the CT still differed significantly from baseline in the low-cost group. Three months after surgery, the CT had returned to baseline values in both groups. There was no significant between-group difference in endothelial cell counts or morphology. CONCLUSIONS: During phacoemulsification in a nonselected patient population, there was no difference in acute postoperative corneal edema and endothelial cell morphology after 3 months between a Viscoat and BSS Plus combination and an Ocucoat and Ringer's solution combination. Eyes receiving the expensive combination had marginally faster recovery of corneal swelling by 3 months. However, the cost of Viscoat and 500 mL BSS Plus is 5 times that of Ocucoat and Ringer's solution.

Intraocular irrigating solutions. A randomized clinical trial of balanced salt solution plus and dextrose bicarbonate lactated Ringer's solution.

BACKGROUND: Two intraocular irrigating solutions which differ principally by the presence of oxidized glutathione were compared in this randomized, masked, prospective study to discern differences in preservation of endothelial cell size. METHODS: Sixty-four patients undergoing extracapsular cataract extractions were randomized between two irrigating solution groups, Balanced Salt Solution (BSS) Plus (n = 30) and dextrose bicarbonate lactated Ringer's solution (n = 34). Preoperative and postoperative endothelial specular photomicrographs were analyzed for cell size and hexagonality, and the two groups were compared using repeated measures analysis of variance. RESULTS: Fifty-eight subjects (91%) completed the 2-month study. Change in cell size for the BSS Plus group (n = 28) (mean +/- standard error, 29.4 +/- 12.3 microns2) was not significantly different from the dextrose bicarbonate lactated Ringer's solution group (n = 30) (27.5 +/- 12.9 microns2) (P = 0.92). Groups did not differ significantly in percent hexagonality (P = 0.57) or in the variability of cell size (P = 0.61). CONCLUSION: The presence of glutathione in BSS Plus and other minor electrolyte differences between the solutions is not more advantageous with regard to endothelial cell size than dextrose bicarbonate lactated Ringer's solution for standard extracapsular cataract surgery. Cost per 500-microliters bottle of BSS plus is $62 compared with $9.80 for dextrose bicarbonate lactated Ringer's solution.

[Functional and economic impact of the use of Wisconsin University conservation solution versus Eurocollins in relation to the period of cold ischemia in renal transplantation of cadaveric donor]. / Impacto funcional y económico de la utilización de la solución de conservación de la Universidad de Wisconsis frente Eurocollins en relación al tiempo de isquemia fría en trasplante renal de donante cadáver.

Comparison of the effect of the Wisconsin University (WU) conservation solution in the graft's functional evolution and survival, and its cost-benefit relationship versus the Eurocollins (EC) solution with regard to cold ischaemia duration in a series of 142 consecutive adults renal transplantations from corpse donor, removed with beating heart. Of 142 kidneys, 92 (64.7%) were kept in WU and 50 (35.2%) in EC. Of the WU group, 62 (67.3%) kidneys were transplanted after a cold ischaemia of under 24 hours and 30 (32.6%) after cold ischaemia of more than 24 hours. In the EC group, 23 (46%) were kept in cold ischaemia for an interval shorter than or equal to 24 hours and 27 (54%) for more than 24 hours. Incidence of initial graft dysfunction (IGD) was greater in the EC groups (65% and 78%) versus the WU groups (39% and 50%), the difference being statistically significant (p). The graft function, as indicated by the creatinine levels was always better in the WU groups. There was a decreased need for complementary dialysis sessions, less days of oliguria and shorter hospitalization in the WU groups (p). There were no significant differences in the four series with regard to rejection episodes, cyclosporin-related nephrotoxicity, and vascular and urinary tract complications. All of which turn cost-effective the higher cost per litre of the WU versus the EC solution. Graft survival at 12 and 24 months was also significantly (p) higher for grafts kept in WU. This paper presents the results obtained in the analysis of our transplanted patients. In our experience, the WU solution allows better conservation of renal grafts, with less IGD and better graft survival at 12 and 24 months. These results turn cost-effective the higher cost per litre of the WU versus the EC solution.

The cost-effectiveness of preservation with UW and EC solution for use in cadaveric kidney transplantation in the case of single kidney donors.

University of Wisconsin (UW) solution is now commonly used as a single-flush solution during multiorgan procurement for effective preservation of all intraabdominal organs including the kidney. Many kidneys from single kidney donors are still preserved in Eurocollins solution and the question is whether preservation in UW solution is more cost-effective. A European randomized multicenter trial was organized by the Department of Surgery of Leiden University in close cooperation with Eurotransplant to study the efficacy of UW solution as compared with EC solution. On the basis of this trial we found that at three months after transplant 92.4% of the patients in the UW group had a functioning graft in comparison with 88.4% in the EC group (similar figures after one year were 88.2% and 82.5%, P approximately 0.04), while health care expenditure during these first three months was on average US$ 700 lower for the UW group than for the EC group, taking into account the price difference in the preservation fluids. The long-term benefits of using UW solution as compared with EC solution were conservatively estimated at US$ 7000 per patient reflecting the additional expenses for dialysis in the EC group. We concluded that the extra costs of using UW solution instead of EC solution (US$ 230 per kidney) can be easily earned back within three months and that the long-term savings of such a strategy are considerable. Moreover, the health status of patients in the UW group is expected to be better on the average than in the EC group. Simply reacting to the price tag of the UW solution may be penny-wise but pound-foolish.