Inter-Day Variability of Metabolites of DEHP and DnBP in Human Urine-Comparability of the Results of Longitudinal Studies with a Cross-Sectional Study.

In the current paper, we compare the inter-day variability of the metabolite concentration of di(2-ethylhexyl) phthalate (DEHP) and di-n-butyl phthalate (DnBP) in 247 morning urine samples obtained from 19 probands of different age and sex with the metabolite concentration in morning urine obtained from 215 probands of the "Tübingen Survey" cross-sectional study. In the first longitudinal study the morning urine of seven volunteers was collected four times a year for seven consecutive days (course of the year study). In a second study the morning urine of 12 students of a boarding school was collected on five consecutive days (course of a week study). For participants of the two different longitudinal studies we obtained mean concentrations in first void morning urine for mono(2-ethyl-5-hydroxyhexyl) phthalate (5OH-MEHP) in the range from 21.3 to 110 µg/L, 10.5 to 35.6 µg/L for mono(2-ethyl-5-oxohexyl) phthalate (5oxo-MEHP), and 45.5 to 143 µg/L for mono(2-ethyl-5-carboxypentyl) phthalate (5cx-MEPP). The corresponding relative standard deviations (rel. Std.D in %) for these DEHP-metabolites vary between 45.2% and 262%. The 50th percentiles vary for 5OH-MEHP between 17.5 and 65.6 µg/L, for 5oxo-MEHP between 9.0 and 20.3 µg/L and for 5cx-MEPP between 42.5 and 82.0 µg/L. For participants of the "Tübingen Survey" cross-sectional study the means vary for 5OH-MEHP between 58.2 and 85.0 µg/L, between 33.6 and 38.7 µg/L for 5oxo-MEHP and between 110 and 158 µg/L for 5cx-MEPP with rel. standard deviations in a range between 86.5 to 175%. The corresponding 50th percentiles vary for 5OH-MEHP between 26.5 and 42.3 µg/L, for 5oxo-MEHP between 18.0 and 26.3 µg/L, and for 5cx-MEPP between 57.2 and 77.6 µg/L. In order to compare the data from the longitudinal studies with the data from the cross-sectional study, the frequency distribution of the results of both types of studies was compared first. In a second step, the results of a t-test (p-values) was used to check whether the results of the long-term studies differ statistically significantly from the results of the cross-sectional study (p < 0.05). The present data show that the frequency distributions of DEHP-metabolites are comparable. For most of the participants respectively subject groups t-test results prove that no statistical significant difference between results obtained from longitudinal studies compared to the results of the cross-sectional study are apparent. The available data on the exposure of individual subjects mirror the data obtained from cross-sectional studies of the general population and give hints to the risk of individual increased DEHP exposure. Results also highlight the importance of living conditions on the risk of increased DEHP exposure.

Evaluation of medical research performance--position paper of the Association of the Scientific Medical Societies in Germany (AWMF).

OBJECTIVE: The evaluation of medical research performance is a key prerequisite for the systematic advancement of medical faculties, research foci, academic departments, and individual scientists' careers. However, it is often based on vaguely defined aims and questionable methods and can thereby lead to unwanted regulatory effects. The current paper aims at defining the position of German academic medicine toward the aims, methods, and consequences of its evaluation. METHODS: During the Berlin Forum of the Association of the Scientific Medical Societies in Germany (AWMF) held on 18 October 2013, international experts presented data on methods for evaluating medical research performance. Subsequent discussions among representatives of relevant scientific organizations and within three ad-hoc writing groups led to a first draft of this article. Further discussions within the AWMF Committee for Evaluation of Performance in Research and Teaching and the AWMF Executive Board resulted in the final consented version presented here. RESULTS: The AWMF recommends modifications to the current system of evaluating medical research performance. Evaluations should follow clearly defined and communicated aims and consist of both summative and formative components. Informed peer reviews are valuable but feasible in longer time intervals only. They can be complemented by objective indicators. However, the Journal Impact Factor is not an appropriate measure for evaluating individual publications or their authors. The scientific "impact" rather requires multidimensional evaluation. Indicators of potential relevance in this context may include, e.g., normalized citation rates of scientific publications, other forms of reception by the scientific community and the public, and activities in scientific organizations, research synthesis and science communication. In addition, differentiated recommendations are made for evaluating the acquisition of third-party funds and the promotion of junior scientists. CONCLUSIONS: With the explicit recommendations presented in the current position paper, the AWMF suggests enhancements to the practice of evaluating medical research performance by faculties, ministries and research funding organizations.

Long-term remission after first-line single-agent treatment with arsenic trioxide of relapsed acute promyelocytic leukemia in an 8-year-old boy.

Arsenic trioxide (ATO) has been proven to be highly effective in adults with newly diagnosed or relapsed acute promyelocytic leukemia (APL). Only very limited data are published on the use of ATO as a single agent for first-line therapy of relapsed APL. The authors present a case of a 8-year-old boy with a bone marrow relapse of APL 7 years after first diagnosis, who achieved durable molecular remission with ATO as single agent: induction therapy for 12 weeks, consolidation for 4 weeks, then 6 cycles of 10 days over a period of 6 months. In total, 140 doses of ATO (0.15 mg/kg/day) were given (21 mg/kg). Consecutive promyelocytic leukemia-retinoic acid receptor α (PML-RARα) RT-PCR analyses were negative with a follow-up of 48 months. Acute or late side effects of arsenic were not observed. At present, the boy is in complete remission 4 years after the diagnosis of the relapse.

Biomonitoring of the di(2-ethylhexyl) phthalate metabolites mono(2-ethyl-5-hydroxyhexyl) phthalate and mono(2-ethyl-5-oxohexyl) phthalate in children and adults during the course of time and seasons.

Di(2-ethylhexyl) phthalate (DEHP) is a commonly used plasticizer with ubiquitous spread. Its metabolites are suspected to impair endocrine functions and fertility in man. This study is aimed to assess the DEHP exposure in children and adults, to evaluate the intraindividual variability, the influence of seasons and to identify potential routes of intake. Urine samples were collected from 6 people (age 4-58) over 7 consecutive days 4-times during a year to test for seasonal factors. 5-OH-MEHP and 5-oxo-MEHP were quantified by GC-MS. Urine concentrations of both metabolites were highly correlated with each other. Both female subjects showed remarkably low and stable 5-OH-MEHP concentrations throughout the year (median

Liver cell death and anemia in Wilson disease involve acid sphingomyelinase and ceramide.

Wilson disease is caused by accumulation of Cu(2+) in cells, which results in liver cirrhosis and, occasionally, anemia. Here, we show that Cu(2+) triggers hepatocyte apoptosis through activation of acid sphingomyelinase (Asm) and release of ceramide. Genetic deficiency or pharmacological inhibition of Asm prevented Cu(2+)-induced hepatocyte apoptosis and protected rats, genetically prone to develop Wilson disease, from acute hepatocyte death, liver failure and early death. Cu(2+) induced the secretion of activated Asm from leukocytes, leading to ceramide release in and phosphatidylserine exposure on erythrocytes, events also prevented by inhibition of Asm. Phosphatidylserine exposure resulted in immediate clearance of affected erythrocytes from the blood in mice. Accordingly, individuals with Wilson disease showed elevated plasma levels of Asm, and displayed a constitutive increase of ceramide- and phosphatidylserine-positive erythrocytes. Our data suggest a previously unidentified mechanism for liver cirrhosis and anemia in Wilson disease.

PVC-plasticizer DEHP in medical products: do thin coatings really reduce DEHP leaching into blood?

The hemocompatibility of artificial surfaces in extracorporeal blood circulation systems can be improved by coatings. According to the literature, heparin coatings should avoid the leaching of the plasticizer di(2-ethylhexyl) phthalate (DEHP) into the blood from components made from plasticized polyvinyl chloride (PVC). DEHP and its metabolites are known to impair the fertility of male rodents; effects on human fertility are assumed. Three different surface coatings with and without heparin were examined in a Chandler Loop model at 37 degrees C using fresh human blood to evaluate their hemocompatibility and barrier property to plasticizer. The levels of toxic oxidation products of DEHP generated in the blood, particularly, were found as high as in the uncoated tubing. The coatings improved the hemocompatibility, but are not safe protection against the hazardous metabolites of DEHP. For pregnant women, neonates and children, we would recommend using the available surface-coated plasticized PVC tubing sets, but free of DEHP.

Synthesis of DEHP metabolites as biomarkers for GC-MS evaluation of phthalates as endocrine disrupters.

Phthalates are used primarily as plasticizers to make polyvinyl chloride (PVC) soft and flexible. In recent years the phthalate esters have attracted increasing attention as environmental and biomedical pollutants and, because of their toxicological characteristics. In particular, they are more and more recognized as endocrine disrupters. In this context, we describe herein an efficient synthetic pathway leading to a series of metabolites of di(2-ethylhexyl) phthalate (DEHP). Mono(2-ethylhexenyl) phthalate was used as starting material to obtain these products in good yield, large scale and GC-MS purity. The metabolites of DEHP were synthesized, for the first time, as biomarkers to verify their quantitative determination in human urine and serum by GC-MS analysis for studying the exposure to phthalates and establishing reference values.

4-Heptanone is a metabolite of the plasticizer di(2-ethylhexyl) phthalate (DEHP) in haemodialysis patients.

BACKGROUND: There is an ongoing discussion about the risks of di(2-ethylhexyl) phthalate (DEHP) exposure for the general population as well as for specific subgroups in various medical settings. Haemodialysis patients certainly belong to the group with the highest exposure taking into account the repeated treatments over a long period of time. Many studies have shown that DEHP metabolites are more active with regard to cellular responses than DEHP itself. Although 4-heptanone has been shown to be a DEHP metabolite in rats, this has never been tested in humans. On the other hand, 4-heptanone was reported to be associated with diabetes mellitus. METHODS: After establishing analytical methods for all postulated metabolites, we analysed (i) plasma samples from 50 patients on haemodialysis and 50 controls; (ii) urine samples from 100 diabetic patients and 100 controls; and (iii) urine samples from 10 controls receiving DEHP intravenously. RESULTS: 4-Heptanone concentrations in urine did not differ between controls (128.6+/-11.4 micro g/l, mean+/- SEM) and diabetic patients (131.2+/-11.6 micro g/l) but were significantly elevated in plasma from haemodialysis patients (95.9+/-9.6 micro g/l) compared with controls (10.4+/-0.5 micro g/l). Exposure to DEHP led to a significant increase (P<0.001) of the metabolite 4-heptanone and all the proposed intermediates in urine of healthy persons within 24 h. CONCLUSIONS: These studies show that 4-heptanone is not associated with diabetes but is a major DEHP metabolite in humans. Studies concerning the toxicity of DEHP in haemodialysis patients and other highly exposed groups should therefore include 4-heptanone together with DEHP and its primary metabolites mono(2-ethylhexyl) phthalate (MEHP) and 2-ethylhexanol.