Correlation of the Glomerular Filtration Rate Measured With the Use of DTPA-Tc99m in Live Kidney Donors With Equations Based on Creatinine and Cystatin C

BACKGROUND

Renal donation leads to a risk of developing chronic kidney disease, with an incidence of 0.47%. To evaluate for its presence, formulas based on serum creatinine are used, but up to 80% of these formulas underestimate the glomerular filtration rate (GFR) in donors. The aim of this work was to confirm the highest correlation of the GFR as measured with the use of DTPA-Tc99m with the GFR as estimated by means of the formula based on serum cystatin C (CKD-EPI creatinine-cystatin C) in healthy kidney donors.

METHODS

In this observational, analytic, cross-sectional study, the GFR of kidney donors was determined ≥1 year after donation by means of DTPA gammagram and estimation with the use of conventional formulations and with cystatin C.

RESULTS

Of 112 donors, 38 (34%) were included, 20 (60%) were female, with an overall average age of 40 years, 36.5 months after donation, and body mass index of 25.5 kg/m². Correlation with the GFR as measured by means of DTPA gammagram was better with the use of CKD-EPI cystatin C (0.402; P = .020) and CKD-EPI creatinine-cystatin (0.549; P < .001) than the conventional formulas. Linear correlation with serum cystatin C was 0.825 (P < .001; 95% confidence interval, -105.3 to -63.2) for the CKD-EPI cystatin C formula, 0.77 (P < .001; -89.9 to -48.1) for the CKD-EPI creatinine-cystatin formula, and 0.525 (P = .002; -91.1 to -23.2) for DTPA-Tc99m scintigraphy.

CONCLUSIONS

There is a strong correlation between estimate the GFR by equations based on cystatin C and the measurement of the GFR by DTPA-Tc99m gammagram.

Photobiotreatment: influence of nitrogen and phosphorus ratio in wastewater on growth kinetics of Scenedesmus obliquus

Nitrogen and phosphorus concentration in the effluent of a wastewater treatment plant can vary significantly, which could affect the growth kinetic and chemical composition of microalgae when cultivated in this medium. The aim of this work was to study the rate of growth, nutrient removal and carbon dioxide biofixation as well as biomass composition of Scenedesmus obliquus (S. obliquus) when it is cultivated in wastewater at different nitrogen and phosphorus ratio, from 1:1 to 35:1. A more homogeneous method for calculating productivities in batch reactors was proposed. The proper N:P ratio for achieving optimum batch biomass productivity ranged between 9 and 13 (263 and 322 mg L(-1) d(-1) respectively). This was also the ratio range for achieving a total N and P removal. Above and below this range (9-13) the maximum biomass concentration changed, instead of the specific growth rate.The maximum carbon dioxide biofixation rate was achieved at N:P ratio between 13 and 22 (553 and 557 mg CO2 L(-1) d(-1) respectively). Lipid and crude protein content, both depend on the aging culture, reaching the maximum lipid content (34%) at the lowest N:P (1:1) and the maximum crude protein content (34.2%) at the highest N:P (35:1).

EOG and EMG: two important switches in automatic sleep stage classification

Sleep is a natural periodic state of rest for the body, in which the eyes are usually closed and consciousness is completely or partially lost. In this investigation we used the EOG and EMG signals acquired from 10 patients undergoing overnight polysomnography with their sleep stages determined by expert sleep specialists based on RK rules. Differentiation between Stage 1, Awake and REM stages challenged a well trained neural network classifier to distinguish between classes when only EEG-derived signal features were used. To meet this challenge and improve the classification rate, extra features extracted from EOG and EMG signals were fed to the classifier. In this study, two simple feature extraction algorithms were applied to EOG and EMG signals. The statistics of the results were calculated and displayed in an easy to visualize fashion to observe tendencies for each sleep stage. Inclusion of these features show a great promise to improve the classification rate towards the target rate of 100%

Effects of losartan and candesartan monotherapy and losartan/hydrochlorothiazide combination therapy in patients with mild to moderate hypertension. Losartan Trial Investigators

OBJECTIVE

The goal of this multicenter, double-blind, randomized, parallel-group study was to compare the effects of losartan potassium (hereafter referred to as losartan), candesartan cilexitil (hereafter referred to as candesartan), and losartan/hydrochlorothiazide (HCTZ) in patients with mild to moderate hypertension (sitting diastolic blood pressure [SiDBP] 95-115 mm Hg).

METHODS

A total of 1161 patients were randomized in a 2:2:1 ratio to 12 weeks of treatment with losartan 50 mg QD, possibly titrated to 100 mg QD (n = 461); candesartan 8 mg QD, possibly titrated to 16 mg QD (n = 468); or losartan 50 mg QD, possibly titrated to losartan 50 mg plus HCTZ 12.5 mg QD (n = 232). At 6 weeks, the regimens of patients not reaching a goal SiDBP <90 mm Hg were titrated as described, whereas patients achieving this goal continued with low-dose monotherapy. The single primary end point at 12 weeks tested the equivalence of the 2 monotherapy regimens, predefined as a maximum between-treatment difference in the mean change from baseline trough SiDBP of 2.5 mm Hg.

RESULTS

At 12 weeks, changes in SiDBP/sitting systolic blood pressure (SiSBP) of -12.4/-14.4 mm Hg with losartan 50 mg/100 mg and -13.1/-15.8 mm Hg with candesartan 8 mg/16 mg demonstrated equivalence between the 2 monotherapy regimens (95% CI for difference in SiDBP, -1.6 to 0.2). At 12 weeks, the losartan 50 mg/50 mg plus HCTZ 12.5 mg regimen had reduced SiDBP/SiSBP significantly more (-14.3/-18.0 mm Hg) than either the candesartan 8 mg/16 mg (SiDBP, P = 0.045; SiSBP, P = 0.017) or losartan 50 mg/100 mg regimen (SiDBP and SiSBP, P = 0.001). During the last 6 weeks, patients whose regimen had been titrated to losartan 50 mg plus HCTZ 12.5 mg (n = 114) showed a greater reduction in SiDBP/SiSBP (-14.5/ -18.7 mm Hg) than did those whose regimen had been titrated to either losartan 100 mg (-10.5/-12.3 mm Hg; n = 211) or candesartan 16 mg (-11.5/-13.2 mm Hg; n = 206), representing a clinically meaningful > or = 2.5-mm Hg) difference. All 3 treatments were well tolerated, with few patients experiencing drug-related adverse events (6.9% losartan 50 mg/100 mg, 7.5% candesartan 8 mg/16 mg, 3.0% losartan 50 mg/ 50 mg plus HCTZ 12.5 mg). Candesartan 8 mg/16 mg increased serum uric acid levels (0.13 mg/dL; 95% CI, 0.04 to 0.23), whereas losartan 50 mg/100 mg decreased them (-0.14 mg/dL; 95% CI, -0.24 to -0.04), and losartan 50 mg/50 mg plus HCTZ 12.5 mg left them unchanged (0.06 mg/dL; 95% CI, -0.07 to 0.20).

CONCLUSIONS

Losartan 50 mg/100 mg and candesartan 8 mg/16 mg were comparable treatments in terms of blood pressure reduction. After titration, losartan 50 mg plus HCTZ 12.5 mg was superior to either candesartan 16 mg or losartan 100 mg in reducing hypertension. Losartan, but not candesartan, lowered serum uric acid levels and attenuated the expected increase in uric acid levels with HCTZ 12.5 mg.