scholarly journals Modelling the Renal Excretion of the Mycotoxin Deoxynivalenol in Humans in an Everyday Situation

Toxins ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 675
Author(s):  
Annick D. van den Brand ◽  
Rudolf Hoogenveen ◽  
Marcel J. B. Mengelers ◽  
Marco Zeilmaker ◽  
Gunnar S. Eriksen ◽  
...  
Keyword(s):  
Optimal Design ◽  
Statistical Model ◽  
Residence Time ◽  
Renal Excretion ◽  
Random Effect ◽  
Dietary Exposure ◽  
Human Biomonitoring ◽  
Elimination Half ◽  
The Mean ◽  
Everyday Situation

The dietary exposure to the mycotoxin deoxynivalenol (DON) can be assessed by human biomonitoring (HBM). Here, we assessed the relation between dietary DON intake and the excretion of its major metabolite DON-15-glucuronide (DON15GlcA) through time, in an everyday situation. For 49 volunteers from the EuroMix biomonitoring study, the intake of DON from each meal was calculated and the excretion of DON and its metabolites was analyzed for each urine void collected separately throughout a 24-h period. The relation between DON and DON15GlcA was analyzed with a statistical model to assess the residence time and the excreted fraction of ingested DON as DON15GlcA (fabs_excr). Fabs_excr was treated as a random effect variable to address its heterogeneity in the population. The estimated time in which 97.5% of the ingested DON was excreted as DON15GlcA was 12.1 h, the elimination half-life was 4.0 h. Based on the estimated fabs_excr, the mean reversed dosimetry factor (RDF) of DON15GlcA was 2.28. This RDF can be used to calculate the amount of total DON intake in an everyday situation, based on the excreted amount of DON15GlcA. We show that urine samples collected over 24 h are the optimal design to study DON exposure by HBM.

scholarly journals THE EFFECTIVENESS OF ULTRASONIC LITHOTRIPTOR COMPARED TO COMBINED ULTRASONIC AND PNEUMATIC LITHOTRIPTOR IN PERCUTANEOUS NEPHROLITHOTOMY (PCNL) SURGERY: A SYSTEMATIC REVIEW AND META-ANALYSIS

2021 ◽  
Vol 28 (2) ◽  
pp. 179-186
Author(s):  
Anggana Suryatmana ◽  
Doddy M. Soebadi ◽  
Tarmono Djojodimedjo
Keyword(s):  
Statistical Model ◽  
Percutaneous Nephrolithotomy ◽  
Meta Analysis ◽  
Random Effect ◽  
Combination Group ◽  
Randomized Controlled ◽  
Stone Free Rate ◽  
Significant Difference ◽  
The Mean ◽  
Free Rate

Objective: To evaluate the effectiveness of the ultrasonic lithotriptor compared to the combined ultrasonic-pneumatic lithotriptor in percutaneous nephrolithotomy (PCNL). Material & Methods: A systematic search was conducted focusing on studies evaluating nephrolithiasis patients who underwent PCNL using pneumatic, ultrasonic, ultrasonic-pneumatic, or laser lithotriptor. The search was conducted in the PUBMED and Science-direct databases from early to September 2020. Results: There were 406 journals in the initial search. On further selection, 3 randomized controlled trials (RCT) were obtained, with a total of 251 patients. The stone-free rate of three studies had low heterogeneity, I2=0% (P=0.34), so a fixed effect statistical model was used. There was no significant difference (P=0.44) between the stone-free rates from the ultrasonic lithotriptor group and the combination with an odds ratio of 1.26 (95% CI = 0.70-2.26). High heterogeneity was obtained with I2=71% (P=0.03) for the mean fragmentation time, so random effect statistical model was used. There was no significant difference (P=0.56) between the mean fragmentation time of the ultrasonic lithotriptor and combination group with a mean difference of -3.69 (95% CI = -16.09-8.71). Conclusion: The ultrasonic lithotriptor did not have a significant difference in stone-free rate, and mean fragmentation time compared to the combined ultrasonic-pneumatic lithotriptor in PCNL. More RCT studies are needed.  

Precipitation and filtration of zinc, magnesium, copper and aluminium hydroxides

1982 ◽  
Vol 47 (12) ◽  
pp. 3362-3370
Author(s):  
Otakar Söhnel ◽  
Eva Matějčková
Keyword(s):  
Residence Time ◽  
Mean Residence Time ◽  
Filtration Resistance ◽  
Filtration Pressure ◽  
Bed Porosity ◽  
The Mean ◽  
Filtration Properties

Filtration properties of batchwise precipitated suspensions of Zn(OH)2, Mg(OH)2 and Cu(OH)2 and continuously precipitated Al(OH)3 were studied. For batchwise precipitated suspensions was verified the theoretically predicted dependence of specific filtration resistance on initial supersaturation and for the continuously precipitated Al(OH)3 the relation between the specific filtration resistance and the mean residence time of suspension in the reactor. Dependences were also recorded between the bed porosity and concentration of precipitated solutions, specific filtration resistance and used filtration pressure and the effect of aging of the batchwise precipitated suspension of Mg(OH)2on its filtration properties. The used CST method for determination of filtration characteristics of Zn(OH)2 suspension was also studied.

Nitrogen use efficiency: does a trade-off exist between the N productivity and the mean residence time within species?

2008 ◽  
Vol 56 (3) ◽  
pp. 272 ◽  
Author(s):  
Zhi Y. Yuan ◽  
Han Y. H. Chen ◽  
Ling H. Li
Keyword(s):  
Residence Time ◽  
Nitrogen Use Efficiency ◽  
Mean Residence Time ◽  
Negative Relationship ◽  
Controlled Experiments ◽  
Nitrogen Use ◽  
Trade Off ◽  
N Supply ◽  
Use Efficiency ◽  
The Mean

Nitrogen use efficiency (NUE) can be divided into two components, i.e. N productivity (A) and the mean residence time (MRT). Controlled experiments indicate that there is not a trade-off between A and MRT within species, but this theory has not been well tested in field conditions. Here, we studied the A, MRT and NUE of Stipa krylovii Roshev. in a grassland over 4 years of N fertilisation experimentation. The three parameters (A, MRT and NUE) were significantly related to soil N supply and there was a negative relationship between A and MRT within this species (r = –0.775, P < 0.05), i.e. plants with higher A had lower MRT. Our results showed a trade-off between A and MRT within this Stipa species and this observed trade-off was attributed to different responses of A and MRT to soil fertility.

62 Feeding Chicory-plantain Silage and Se-yeast to Lactating Ewes Subjected to Intramammary Infection: Effect on the Immune System

2021 ◽  
Vol 99 (Supplement_3) ◽  
pp. 32-33
Author(s):  
Hunter Ford ◽  
Massimo Bionaz ◽  
Serkan Ates ◽  
Joe Klopfenstein ◽  
Jorge Vanegas ◽  
...  
Keyword(s):  
Fixed Effects ◽  
Complete Blood Count ◽  
Random Effect ◽  
Mean Cell Volume ◽  
Distribution Width ◽  
Intramammary Infection ◽  
Alfalfa Meal ◽  
The Mean ◽  
To Receive ◽  
Positive Effect

Abstract The objective was to test the effect on the immune status by feeding a combination of chicory-plantain and Se-yeast in lactating ewes subjected to intramammary infection (IMI) with 2×107CFU of Strep uberis in both glands. For the purpose we enrolled 28 Polypay lactating sheep from a prior study where they were randomly allocated to receive chicory (CS) or grass (GC) silage and either 3.6 mg of Se/day as Se-yeast (DiaMune, Diamond V) (Y) or isoenergetic-isonitrogenous alfalfa meal (C) for 2 months. For the present study, ewes were kept on the original dietary regiment except the CT group received a chicory-plantain silage(50% each). Blood was collected prior to and for 10 days after IMI for a complete blood count(VetScan HM5), leukocytes migration, and rectal temperature (RT). Data were analyzed using GLIMMIX (SAS)with time, silage type, and Se and their interactions as the fixed effects and ewe as random effect with significance declared at P ≤ 0.05. RT was lower in chicory vs. grass before IMI and Se limited the RT increase after IMI. Total WBC levels tended (P = 0.06) to increase in animals fed with Se after IMI, which was driven by a larger number of lymphocytes. Hematocrit, red blood cells, and hemoglobin were strongly decreased by IMI. The mean cell volume was overall larger in ewes fed with chicory-plantain silage while mean cell hemoglobin was larger in animal fed with grass silage. The platelet distribution width was affected by silage*Se interaction due to a positive effect by Se in grass-fed but negative in chicory-plantain-fed ewes. Migration of neutrophils was larger in animals fed with chicory-plantain before IMI but similar between groups after IMI. Overall, these findings indicate that Se supplementation can increase lymphocytes with no effect on neutrophils while activity of neutrophils is positively affected by feeding chicory-plantain silage.

scholarly journals Serum bactericidal activities and comparative pharmacokinetics of meropenem and imipenem-cilastatin.

1996 ◽  
Vol 40 (1) ◽  
pp. 105-109 ◽  
Author(s):  
M Dreetz ◽  
J Hamacher ◽  
J Eller ◽  
K Borner ◽  
P Koeppe ◽  
...  
Keyword(s):  
Compartment Model ◽  
Pharmacokinetic Parameters ◽  
Time Curve ◽  
Dose Administration ◽  
Microdilution Method ◽  
Two Compartment Model ◽  
Elimination Half ◽  
Renal Clearances ◽  
The Mean ◽  
Bactericidal Activities

The pharmacokinetics and serum bactericidal activities (SBAs) of imipenem and meropenem were investigated in a randomized crossover study. Twelve healthy male volunteers received a constant 30-min infusion of either 1 g of imipenem plus 1 g of cilastatin or 1 g of meropenem. The concentrations of the drugs in serum and urine were determined by bioassay and high-pressure liquid chromatography. Pharmacokinetic parameters were based on an open two-compartment model and a noncompartmental technique. At the end of infusion, the mean concentrations of imipenem and meropenem measured in serum were 61.2 +/- 9.8 and 51.6 +/- 6.5 mg/liter, respectively; urinary recoveries were 48.6% +/- 8.2% and 60.0% +/- 6.5% of the dose in 12 h, respectively; and the areas under the concentration-time curve from time zero to infinity were 96.1 +/- 14.4 and 70.5 +/- 10.3 mg.h/liter, respectively (P < or = 0.02). Imipenem had a mean half-life of 66.7 +/- 10.4 min; that of meropenem was 64.4 +/- 6.9 min. The volumes of distribution at steady state of imipenem and meropenem were 15.3 +/- 3.3 and 18.6 +/- 3.0 liters/70 kg, respectively, and the mean renal clearances per 1.73 m2 were 85.6 +/- 17.6 and 144.6 +/- 26.0 ml/min, respectively. Both antibiotics were well tolerated in this single-dose administration study. The SBAs were measured by the microdilution method of Reller and Stratton (L. B. Reller and C. W. Stratton, J. Infect. Dis. 136:196-204, 1977) against 40 clinically isolated strains. Mean reciprocal bactericidal titers were measured 1 and 6 h after administration. After 1 and 6 h the median SBAs for imipenem and meropenem, were 409 and 34.9 and 97.9 and 5.8, respectively, against Staphylococcus aureus, 19.9 and 4.4 and 19.4 and 4.8, respectively, against Pseudomonas aeruginosa, 34.3 and 2.2 and 232 and 15.5, respectively, against Enterobacter cloacae, and 13.4 and 2.25 and 90.7 and 7.9, respectively, against Proteus mirabilis. Both drugs had rather short biological elimination half-lives and a predominantly renal route of elimination. Both carbapenems revealed high SBAs against clinically important pathogens at 1 h; meropenem had a higher SBA against E. cloacae and P. mirabilis, and the SBA of imipenem against S. aureus was greater than the SBA of meropenem.

scholarly journals Discussion of Identification, Estimation and Approximation of Risk under Interventions that Depend on the Natural Value of Treatment Using Observational Data, by Jessica Young, Miguel Hernán, and James Robins

2014 ◽  
Vol 3 (1) ◽  
Author(s):  
Mark J. van der Laan ◽  
Alexander R. Luedtke ◽  
Iván Díaz
Keyword(s):  
Statistical Model ◽  
Observational Data ◽  
Robust Estimation ◽  
Statistical Estimation ◽  
Estimation Problem ◽  
Target Parameter ◽  
Adaptive Parameters ◽  
The Mean ◽  
Data Adaptive ◽  
Statistical Estimation Problem

AbstractYoung, Hernán, and Robins consider the mean outcome under a dynamic intervention that may rely on the natural value of treatment. They first identify this value with a statistical target parameter, and then show that this statistical target parameter can also be identified with a causal parameter which gives the mean outcome under a stochastic intervention. The authors then describe estimation strategies for these quantities. Here we augment the authors’ insightful discussion by sharing our experiences in situations where two causal questions lead to the same statistical estimand, or the newer problem that arises in the study of data adaptive parameters, where two statistical estimands can lead to the same estimation problem. Given a statistical estimation problem, we encourage others to always use a robust estimation framework where the data generating distribution truly belongs to the statistical model. We close with a discussion of a framework which has these properties.

scholarly journals Pharmacokinetics of Intravenous Piperacillin Administration in Patients Undergoing On-Line Hemodiafiltration

2009 ◽  
Vol 53 (8) ◽  
pp. 3266-3268 ◽  
Author(s):  
Kook-Hwan Oh ◽  
Chiweon Kim ◽  
Hankyu Lee ◽  
Hajeong Lee ◽  
Ji Yong Jung ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Total Body Clearance ◽  
Volume Of Distribution ◽  
Pharmacokinetic Parameters ◽  
Recovery Method ◽  
Elimination Half ◽  
On Line ◽  
The Mean ◽  
Total Body ◽  
Body Clearance

ABSTRACT The pharmacokinetic characteristics of piperacillin sodium were studied in five volunteers undergoing on-line hemodiafiltration (HDF). The subjects were given 2 g of piperacillin sodium intravenously over 1 min and placed on on-line HDF for 4 h starting at 60 min after the piperacillin infusion. Noncompartmental models were employed for estimation of the pharmacokinetic parameters, and intradialytic piperacillin clearance was calculated by the recovery method. The mean volume of distribution and the elimination half-life were 0.27 ± 0.13 liter/kg (mean ± standard deviation) and 1.1 ± 0.6 h, respectively. The total body clearance of piperacillin was 0.19 ± 0.08 liter/h/kg. Piperacillin clearance through on-line HDF was 0.11 ± 0.06 liter/h/kg. The mean serum piperacillin concentration was 4.0 ± 1.9 μg/ml at the end of the 4-h on-line HDF session. The concentration of infused piperacillin recovered in the dialysate was 527 ± 236 mg (26.3% ± 11.8%). We suggest the replacement of 500 mg of piperacillin after each on-line HDF session.

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