Differential accumulation of low-chlorinated (Delor 103) and high-chlorinated (Delor 106) biphenyls in human placental tissue and opposite effects on conversion of DHEA to E2.

OBJECTIVE: Polychlorinated biphenyls (PCBs) and related compounds elicit a diverse spectrum of toxic responses. Additionally, they are able to pass through the human placenta. The aim of the presented data was to compare the action of low-chlorinated (Delor 103) and (Delor 106) high-chlorinated biphenyls on placental steroidogenesis. METHODS: Explants of human placental tissue were used to test differences in PCBs accumulation and influence on placental steroidogenesis. Delor 103 or 106, were added daily for six days at a dose of 200 pg from day 0 to day 6 of culture. The media in the control and experimental groups were changed every day, and collected and frozen for steroid analysis by RIA. Determinations of PCBs of tissue and medium were analysed by GC/MS/MS. RESULTS: Delor 103 was found at a higher level in the tissue than Delor 106. The first day of exposure to Delor 103 had no effect on the conversion of dehydroepiandrosterone (DHEA) to estradiol (E2) while there was a 2-fold decrease in E2 secretion from days 3 to 6. Conversely, Delor 106 caused an immediate increase in E2 secretion, which was maintained at higher levels throughout the exposure period. CONCLUSION: Differences between the accumulation of lower chlorinated and higher chlorinated biphenyls in human placental tissue and in the properties of the congeners can have multiple effects that may intensify or counteract the effects on uterine contraction by PCBs.

[The role of cholesterol and intermediary metabolites of its synthesis in intensive care and parenteral nutrition]. / Uloha cholesterolu a intermediárních metabolitu jeho syntézy v intenzivní péci a umelé výzive.

Hypocholesterolaemia is a frequent and typical phenomenon of many acute situations such as injury, severe infection associated with sepsis and septic shock, catabolic situations after serious operations, in myocardial infarction and neoplastic diseases. This phenomenon cannot be explained only by malnutrition or energy deficiency although they may participate in the development of hypocholesterolaemia. In the development of the mentioned acute conditions participates according to our opinion also impaired synthesis of cholesterol as well as of intermediary metabolites of its biosynthesis (isoprene, squalene, lanosterol, and lathosterol). Evidence was provided that deprivation of these metabolites is frequent, very marked and statistically significant. Some precursors of cholesterol biosynthesis are extremely important for normal processes in the cell and as mediators (isoprene, farnesyl diphosphate, squalene). Their deficiency is a serious disorder which must be diagnosed in time. It is important to define the patients and conditions where a serious deficiency of these metabolites develops regularly and to seek ways how to treat deprivation of the mentioned metabolites.

[Hypocholesterolemia after multiple injuries is not caused by simple hemodilution]. / Hypocholesterolemie po polytraumatu není zpusobena prostou hemodilucí.

The authors examined in 45 patients with multiple injuries total serum cholesterol levels and the packed cell volume on admission, 24 hours and 48 hours after injury. The cholesterol level in these patients declined as compared with a control group to 0.61 on admission of the patient (on average 102 min. after injury) and to 0.51 and 0.53 24 and 48 hours after injury, while the packed cell volume declined to 0.76 on admission and to 0.64 24 and 48 hours after the injury. The lose correlation between cholesterol and the packed cell volume (r2 = 0.27) suggests the part played by another mechanism of development of hypocholesterolaemia in patients with multiple injuries than mere haemodilution. In eight patients who died no correlation with hypocholesterolaemia was found.

Determination of isoprene in human expired breath using solid-phase microextraction and gas chromatography-mass spectrometry.

An analytical method for determination of isoprene in expired breath as a marker of body cholesterol synthesis was developed with a special emphasis on breath sampling. Patients were breathing controlled air using respiratory masks for 2 min (washout period) and then their expired breath was collected in 8-1 Tedlar bags. The bags were heated to 40 degrees C and the solid-phase microextraction fiber Carboxen-polydimethylsiloxane 75 microm was inserted through the septum. Extraction time was 10 min. Analytes were desorbed in the GC injector for 2 min at 270 degrees C. Analyses were performed on a Q-PLOT column and fragment ions 68, 67 and 53 were quantified. The concentration range was 1-40 nmol/l, limit of detection was 0.25 nmol/l, the calibration curve was linear. Precision, expressed as RSD, was 5.5-12.5%. These tests are non-invasive, feasible and relatively inexpensive.