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Research paper thumbnail of Dialysis Adequacy After Deceased Donor Transplantation

Transplantation Proceedings, 2009

Research paper thumbnail of A new spectrophotometric method to detect residual amounts of peroxide after reprocessing hemodialysis filters

Einstein (São Paulo), 2011

Objective: Reuse of hemodialysis filters is a standard practice and the sterilizing chemical most... more Objective: Reuse of hemodialysis filters is a standard practice and the sterilizing chemical most often employed is peracetic acid. Before starting the dialysis session, filters and lines are checked for residual levels of peracetic acid by means of a non-quantitative colorimetric test that is visually interpreted. The objective of this study was to investigate a new quantitative spectrophotometric test for detection of peracetic acid residues. Methods: Peracetic acid solutions were prepared in concentrations ranging from 0.01 to 10 ppm. A reagent (potassium-titanium oxide + sulfuric acid) was added to each sample in proportions varying from 0.08 to 2.00 drops/mL of solution. Optical densities were determined in a spectrophotometer using a 405-nm filter and subjected to visual qualitative test by different observers. Results: A relation between peroxide concentrations and respective optical densities was observed and it was linear with R2…

Research paper thumbnail of Clinical Implications of Initial Renal Function After Deceased Donor Transplant

The aim of this study was to investigate whether slow graft function (SGF) after transplantation ... more The aim of this study was to investigate whether slow graft function (SGF) after transplantation of deceased-donor kidneys affected the prevalence of anemia or the glomerular filtration rate (GFR). We retrospectively evaluated the records of 534 kidney transplant patients who were classified based on their initial renal function, namely, immediate graft function (IGF), slow graft function (SGF), or delayed graft function (DGF). Among the 534 kidney transplant patients studied, the occurrences of each condition were IGF 104, SGF 133, and DGF 297. Six months after transplantation, a greater percentage of DGF patients were anemic compared with the others (P = .028). However, at 12 months after transplantation, SGF patients showed more anemia than the IGF group. DGF and SGF patients displayed similar GFR values at 18 and 24 months after transplantation. However, IGF patients displayed higher GFRs, even when subjects who experienced acute rejection episodes were censored (P = .004). The incidence of acute rejection episodes was similar among SGF and DGF patients. Patients displaying SGF after deceased-donor transplantation showed a greater tendency to be anemic than those displaying IGF. This study also suggested that SGF patients were at risk for acute rejection episodes and/or significantly reduced kidney function as measured by GFR.

Research paper thumbnail of Effect of phosphate binders on oxidative stress and inflammation markers in hemodialysis patients

Hemodialysis …, 2009

It has been suggested that phosphate binders may reduce the inflammatory state of hemodialysis (H... more It has been suggested that phosphate binders may reduce the inflammatory state of hemodialysis (HD) patients. However, it is not clear whether it has any effect on oxidative stress. The objective of this study was to evaluate the effect of sevelamer hydrochloride (SH) and calcium acetate (CA) on oxidative stress and inflammation markers in HD patients. Hemodialysis patients were randomly assigned to therapy with SH (n =17) or CA (n =14) for 1 year. Before the initiation of therapy (baseline) and at 12 months, we measured in vitro reactive oxygen species (ROS) production by stimulated and unstimulated polymorphonuclear neutrophils and serum levels of tumor necrosis factor a, interleukin-10, C-reactive protein, and albumin. There was a significant reduction of spontaneous ROS production in both groups after 12 months of therapy. There was a significant decrease of Staphylococcus aureus stimulated ROS production in the SH group. There was a significant increase in albumin serum levels only in the SH group. In the SH group, there was also a decrease in the serum levels of tumor necrosis factor a and C-reactive protein. Our results suggest that compared with CA treatment, SH may lead to a reduction in oxidative stress and inflammation. Therefore, it is possible that phosphate binders exert pleiotropic effects on oxidative stress and inflammation, which could contribute toward decreasing endothelial injury in patients in HD.

Research paper thumbnail of A new spectrophotometric method to detect residual amounts of peroxide after reprocessing hemodialysis filters

Einstein (São Paulo), 2011

Objective: Reuse of hemodialysis filters is a standard practice and the sterilizing chemical most... more Objective: Reuse of hemodialysis filters is a standard practice and the sterilizing chemical most often employed is peracetic acid. Before starting the dialysis session, filters and lines are checked for residual levels of peracetic acid by means of a non-quantitative colorimetric test that is visually interpreted. The objective of this study was to investigate a new quantitative spectrophotometric test for detection of peracetic acid residues. Methods: Peracetic acid solutions were prepared in concentrations ranging from 0.01 to 10 ppm. A reagent (potassium-titanium oxide + sulfuric acid) was added to each sample in proportions varying from 0.08 to 2.00 drops/mL of solution. Optical densities were determined in a spectrophotometer using a 405-nm filter and subjected to visual qualitative test by different observers. Results: A relation between peroxide concentrations and respective optical densities was observed and it was linear with R 2 > 0.90 for all reagent/substrate proportions. The peak optical densities were obtained with the reagent/substrate ratio of 0.33 drops/mL, which was later standardized for all further experiments. Both qualitative and quantitative tests yielded a specificity of 100%. The quantitative test was more sensitive than the qualitative test and resulted in higher positive and negative predictive values. There was a difference between observers in the qualitative test and some samples with significant amounts of peroxide were not detected. Conclusion: A quantitative spectrophotometric test may improve detection of residues of peracetic acid when compared to the standard visual qualitative test. This innovation may contribute to the development of safer standards for reuse of hemodialysis filters.

Research paper thumbnail of Dialysis Adequacy After Deceased Donor Transplantation

Transplantation Proceedings, 2009

Delayed graft function (DGF) is defined as the necessity for dialysis during the first week after... more Delayed graft function (DGF) is defined as the necessity for dialysis during the first week after transplantation. This study sought to describe patterns of dialysis prescription and evaluate the impact of dialysis dose in acute rejection. Among 82 patients who received a deceased donor kidney transplant, clinical and laboratory data were evaluated at the moment of dialysis indication. Prescribed and delivered dialysis doses (Kt/V and urea reduction ratio) were analyzed during the first dialysis and the first week (Kt/V) after transplantation. We examined the association between Kt/V and acute rejection. Prescribed Kt/V at the first dialysis session was adequate (2.24 Ϯ 0.51). However, delivered Kt/V was inadequate (0.75 Ϯ 0.38). Prescribed and delivered Kt/V during the first week after transplantation were suboptimal, namely, 2.45 Ϯ 1.52 and 1.56 Ϯ 0.99, respectively. Dialysis dose had no impact on the occurrence of an acute rejection episode. Among DGF patient, dialysis was prescribed late and a low dose was achieved.

Research paper thumbnail of Dialysis Adequacy After Deceased Donor Transplantation

Transplantation Proceedings, 2009

Research paper thumbnail of A new spectrophotometric method to detect residual amounts of peroxide after reprocessing hemodialysis filters

Einstein (São Paulo), 2011

Objective: Reuse of hemodialysis filters is a standard practice and the sterilizing chemical most... more Objective: Reuse of hemodialysis filters is a standard practice and the sterilizing chemical most often employed is peracetic acid. Before starting the dialysis session, filters and lines are checked for residual levels of peracetic acid by means of a non-quantitative colorimetric test that is visually interpreted. The objective of this study was to investigate a new quantitative spectrophotometric test for detection of peracetic acid residues. Methods: Peracetic acid solutions were prepared in concentrations ranging from 0.01 to 10 ppm. A reagent (potassium-titanium oxide + sulfuric acid) was added to each sample in proportions varying from 0.08 to 2.00 drops/mL of solution. Optical densities were determined in a spectrophotometer using a 405-nm filter and subjected to visual qualitative test by different observers. Results: A relation between peroxide concentrations and respective optical densities was observed and it was linear with R2…

Research paper thumbnail of Clinical Implications of Initial Renal Function After Deceased Donor Transplant

The aim of this study was to investigate whether slow graft function (SGF) after transplantation ... more The aim of this study was to investigate whether slow graft function (SGF) after transplantation of deceased-donor kidneys affected the prevalence of anemia or the glomerular filtration rate (GFR). We retrospectively evaluated the records of 534 kidney transplant patients who were classified based on their initial renal function, namely, immediate graft function (IGF), slow graft function (SGF), or delayed graft function (DGF). Among the 534 kidney transplant patients studied, the occurrences of each condition were IGF 104, SGF 133, and DGF 297. Six months after transplantation, a greater percentage of DGF patients were anemic compared with the others (P = .028). However, at 12 months after transplantation, SGF patients showed more anemia than the IGF group. DGF and SGF patients displayed similar GFR values at 18 and 24 months after transplantation. However, IGF patients displayed higher GFRs, even when subjects who experienced acute rejection episodes were censored (P = .004). The incidence of acute rejection episodes was similar among SGF and DGF patients. Patients displaying SGF after deceased-donor transplantation showed a greater tendency to be anemic than those displaying IGF. This study also suggested that SGF patients were at risk for acute rejection episodes and/or significantly reduced kidney function as measured by GFR.

Research paper thumbnail of Effect of phosphate binders on oxidative stress and inflammation markers in hemodialysis patients

Hemodialysis …, 2009

It has been suggested that phosphate binders may reduce the inflammatory state of hemodialysis (H... more It has been suggested that phosphate binders may reduce the inflammatory state of hemodialysis (HD) patients. However, it is not clear whether it has any effect on oxidative stress. The objective of this study was to evaluate the effect of sevelamer hydrochloride (SH) and calcium acetate (CA) on oxidative stress and inflammation markers in HD patients. Hemodialysis patients were randomly assigned to therapy with SH (n =17) or CA (n =14) for 1 year. Before the initiation of therapy (baseline) and at 12 months, we measured in vitro reactive oxygen species (ROS) production by stimulated and unstimulated polymorphonuclear neutrophils and serum levels of tumor necrosis factor a, interleukin-10, C-reactive protein, and albumin. There was a significant reduction of spontaneous ROS production in both groups after 12 months of therapy. There was a significant decrease of Staphylococcus aureus stimulated ROS production in the SH group. There was a significant increase in albumin serum levels only in the SH group. In the SH group, there was also a decrease in the serum levels of tumor necrosis factor a and C-reactive protein. Our results suggest that compared with CA treatment, SH may lead to a reduction in oxidative stress and inflammation. Therefore, it is possible that phosphate binders exert pleiotropic effects on oxidative stress and inflammation, which could contribute toward decreasing endothelial injury in patients in HD.

Research paper thumbnail of A new spectrophotometric method to detect residual amounts of peroxide after reprocessing hemodialysis filters

Einstein (São Paulo), 2011

Objective: Reuse of hemodialysis filters is a standard practice and the sterilizing chemical most... more Objective: Reuse of hemodialysis filters is a standard practice and the sterilizing chemical most often employed is peracetic acid. Before starting the dialysis session, filters and lines are checked for residual levels of peracetic acid by means of a non-quantitative colorimetric test that is visually interpreted. The objective of this study was to investigate a new quantitative spectrophotometric test for detection of peracetic acid residues. Methods: Peracetic acid solutions were prepared in concentrations ranging from 0.01 to 10 ppm. A reagent (potassium-titanium oxide + sulfuric acid) was added to each sample in proportions varying from 0.08 to 2.00 drops/mL of solution. Optical densities were determined in a spectrophotometer using a 405-nm filter and subjected to visual qualitative test by different observers. Results: A relation between peroxide concentrations and respective optical densities was observed and it was linear with R 2 > 0.90 for all reagent/substrate proportions. The peak optical densities were obtained with the reagent/substrate ratio of 0.33 drops/mL, which was later standardized for all further experiments. Both qualitative and quantitative tests yielded a specificity of 100%. The quantitative test was more sensitive than the qualitative test and resulted in higher positive and negative predictive values. There was a difference between observers in the qualitative test and some samples with significant amounts of peroxide were not detected. Conclusion: A quantitative spectrophotometric test may improve detection of residues of peracetic acid when compared to the standard visual qualitative test. This innovation may contribute to the development of safer standards for reuse of hemodialysis filters.

Research paper thumbnail of Dialysis Adequacy After Deceased Donor Transplantation

Transplantation Proceedings, 2009

Delayed graft function (DGF) is defined as the necessity for dialysis during the first week after... more Delayed graft function (DGF) is defined as the necessity for dialysis during the first week after transplantation. This study sought to describe patterns of dialysis prescription and evaluate the impact of dialysis dose in acute rejection. Among 82 patients who received a deceased donor kidney transplant, clinical and laboratory data were evaluated at the moment of dialysis indication. Prescribed and delivered dialysis doses (Kt/V and urea reduction ratio) were analyzed during the first dialysis and the first week (Kt/V) after transplantation. We examined the association between Kt/V and acute rejection. Prescribed Kt/V at the first dialysis session was adequate (2.24 Ϯ 0.51). However, delivered Kt/V was inadequate (0.75 Ϯ 0.38). Prescribed and delivered Kt/V during the first week after transplantation were suboptimal, namely, 2.45 Ϯ 1.52 and 1.56 Ϯ 0.99, respectively. Dialysis dose had no impact on the occurrence of an acute rejection episode. Among DGF patient, dialysis was prescribed late and a low dose was achieved.