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CONTEXT: Reliable estradiol (E2) reference intervals (RIs) are crucial in Pediatric Endocrinology. OBJECTIVES: To develop a sensitive ultra-performance liquid chromatographic tandem mass spectrometry (UPLC-MS/MS) method for E2 in serum, to establish graphically represented RI percentiles and annual RIs for both sexes and to perform a systematic literature comparison. METHODS: First, an UPLC-MS/MS method for E2 was developed. Second, graphically represented RI percentiles and annual RIs covering 0-18 years were computed (cohort of healthy children (1181 girls, 543 boys)). Subsequently, RIs were compared with published data by systematic searches. RESULTS: Lower limit of quantification was 11 pmol/L, indicating high sensitivity. E2 first peaked during mini-puberty in both sexes (girls up to 192 pmol/L; boys up to: 225 pmol/L). As could be expected, girls showed higher pubertal E2 (up to 638 pmol/L). However, boys' RIs (up to 259 pmol/L) overlapped considerably. We found four studies in the literature which also used LC-MS/MS to determine E2 and published RIs for the complete pediatric age range. RIs varied considerably. Pre-pubertal and pubertal phases were present in all studies. Higher E2 during the time of mini-puberty in both sexes was documented in three studies including ours. CONCLUSIONS: Variability of RIs for E2 between studies illustrates importance of laboratory-specific RIs despite using a liquid chromatographic tandem mass spectrometry (LC-MS/MS) reference method. In boys, the striking E2 peak during mini-puberty as well as high pubertal E2 without phenotypic estrogenization in regular male puberty indicate that the role of E2 in children, and especially in boys requires better functional understanding.
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Glucocorticoids represent a key element in the treatment of pediatric acute lymphoblastic leukemia (ALL) and lead to adrenal suppression. We aimed to assess the differential response profile of adrenal steroids in children with ALL during BFM (Berlin-Frankfurt-Münster) induction treatment. Therefore, we performed liquid chromatography tandem-mass spectrometry (LC-MS/MS)-based steroid profiling of up to seven consecutive leftover morning serum samples derived from 11 patients (pts) with ALL before (day 0) and during induction therapy at days 1-5, 6-12, 13-26, 27-29, 30-35 and 36-40. 17-hydroxyprogesterone (17OHP), 11-deoxycortisol (11S), cortisol, 11-deoxycorticosterone (DOC), corticosterone and aldosterone were determined in parallel. Subsequently, steroid concentrations were normalized by multiples of median (MOM) to adequately consider pediatric age- and sex-specific reference ranges. MOM-cortisol and its precursors MOM-11S and MOM-17OHP were significantly suppressed by glucocorticoid treatment until day 29 (P < 8.06 × 10-10, P < 5.102 × 10-5, P < 0.0076, respectively). Cortisol recovered in one of four pts at days 27-29 and in two of five pts at days 36-40. Among the mineralocorticoids, corticosterone was significantly suppressed (P < 3.115 × 10-6). Aldosterone and DOC showed no significant changes when comparing day 0 to the treatment time points. However, two ALL patients with ICU treatment due to the sepsis showed significantly lower MOM-DOC (P = 0.006436) during that time and almost always the lowest aldosterone compared to all other time points. Suppression of mineralocorticoid precursors under high-dose glucocorticoid therapy suggests a functional cross talk of central glucocorticoid regulation and adrenal mineralocorticoid synthesis. Our data should stimulate prospective investigation to assess potential clinical relevance.
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Ongoing habitat loss and fragmentation result in rapid population size reductions, which can increase the levels of inbreeding. Consequently, many species are threatened by inbreeding depression, a loss of individual fitness following the mating of close relatives. Here, we investigated inbreeding effects on fitness-related traits throughout the lifetime of the mustard leaf beetle (Phaedon cochleariae) and mechanisms for the avoidance of inbreeding. Previously, we found that these beetles have family-specific cuticular hydrocarbon profiles, which are likely not used as recognition cue for precopulatory inbreeding avoidance. Thus, we examined whether adult beetles show postcopulatory inbreeding avoidance instead. For this purpose, we determined the larval hatching rate of eggs laid by females mated sequentially with two nonsiblings, two siblings, a nonsibling, and a sibling or vice versa. The beetles suffered from inbreeding depression throughout their entire ontogeny, as evinced by a prolonged larval development, a decreased larval and adult survival and a decreased reproductive output of inbred compared to outbred individuals. The highest larval hatching rates were detected when females were mated with two nonsiblings or first with a sibling and second with a nonsibling. Significantly lower hatching rates were measured in the treatments with a sibling as second male. Thus, the results do not support the existence of postcopulatory inbreeding avoidance in P. cochleariae, but revealed evidence for second male sperm precedence. Consequently, an alternative strategy to avoid inbreeding costs might exist in this beetle, such as a polyandrous mating system, potentially coupled with a specific dispersal behavior.
