251 research outputs found

    Changes in anterior head patterning underlie the evolution of long germ embryogenesis

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    AbstractEarly embryonic stages differ significantly among related animal taxa while subsequent development converges at the conserved phylotypic stage before again diverging. Although this phenomenon has long been observed, its underlying genetic mechanisms remain enigmatic. The dipteran Drosophila melanogaster develops as a long germ embryo where the head anlagen form a cap at the anterior pole of the blastoderm. Consequently, the anterior and terminal maternal systems give crucial input for head patterning. However, in the short germ beetle Tribolium castaneum, as in most insects, the head anlagen is located at a ventral position distant from the anterior pole of the blastoderm. In line with these divergent embryonic anlagen, several differences in the axis formation between the insects have been discovered. We now ask to what extent patterning and morphogenesis of the anterior median region (AMR) of the head, including clypeolabral and stomodeal anlagen, differ among these insects. Unexpectedly, we find that Tc-huckebein is not a terminal gap gene and, unlike its Drosophila ortholog, is not involved in Tribolium head development. Instead, Tc-six3 acts upstream of Tc-crocodile and Tc-cap'n'collar to pattern posterior and anterior parts of the AMR, respectively. We further find that instead of huckebein, Tc-crocodile is required for stomodeum development by activating Tc-forkhead. Finally, a morphogenetic movement not found in Drosophila shapes the embryonic head of Tribolium. Apparently, with anterior displacement of the head anlagen during long germ evolution of Drosophila, the ancestral regulation by the bilaterian anterior control gene six3 was replaced by the anterior and terminal maternal systems, which were further elaborated by adding bicoid, tailless and huckebein as anterior regionalization genes

    Pulse oximetry in the newborn: Is the left hand pre- or post-ductal?

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    Background: Over the past few years, great efforts have been made to screen duct-dependent congenital heart diseases in the newborn. Arterial pulse oximetry screening (foot and/or right hand) has been put forth as the most useful strategy to prevent circulatory collapse. The left hand, however, has always been ignored, as it was unclear if the ductus arteriosus influences left-hand arterial perfusion. The objective of our study was to evaluate the impact of the arterial duct on neonatal pulse oximetry saturation (POS) on the left hand. Methods: In this observational study, arterial oxygen saturation on both hands and on one foot was measured within the first 4 hours of life. Results: Two hundred fifty-one newborns were studied: 53% males and 47% were delivered by caesarean section. The median gestational age was 38 4/7 weeks (90% CI, 32 6/7 - 41 2/7 weeks), the median birth weight was 3140 g (90% CI, 1655 - 4110 g) and the median age at recording was 60 minutes (90% CI, 15 - 210 minutes). The mean POS for the overall study population was 95.7% (90% CI, 90 - 100%) on the right hand, 95.7% (90% CI, 90 - 100%) on the left hand, and 94.9% (90% CI, 86 - 100%) on the foot. Four subgroups (preterm infants, babies with respiratory disorders, neonates delivered by caesarean section, and newborns ≤15 minutes of age) were formed and analysed separately. None of the subgroups showed a statistically significant difference between the right and left hands. Additionally, multivariate logistic regression did not identify any associated factors influencing the POS on the left hand. Conclusions: With the exception of some children with complex or duct dependent congenital heart defects and some children with persistent pulmonary hypertension, POS on both hands can be considered equally pre-ductal

    Early enteral feeding in conservatively managed stage II necrotizing enterocolitis is associated with a reduced risk of catheter-related sepsis

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    Aims: To compare the effect of fasting period duration on complication rates in neonates managed conservatively for necrotizing enterocolitis (NEC) Bell stage II. Methods: We conducted a multicenter study to analyze retrospectively multiple data collected by standardized questionnaire on all admissions for NEC between January 2000 and December 2006. NEC was staged using modified Bell criteria. We divided the conservatively managed neonates with NEC Bell stage II into two groups (those fasted for 5days) and compared the complication rates. Results: Of the 47 conservatively managed neonates Bell stage II, 30 (64%) fasted for 5days (range 6-16days). There were no significant differences for any of the patient characteristics analyzed. One (3%) and four (24%) neonates, respectively, developed post-NEC bowel stricture. One (3%) and two neonates (12%) suffered NEC relapse. None and five (29%) neonates developed catheter-related sepsis. Conclusion: Shorter fasting after NEC appears to lower morbidity after the acute phase of the disease. In particular, shorter-fasted neonates have significantly less catheter-related sepsis. We found no benefit in longer fastin

    17-Hydroxyprogesterone in premature infants as a marker of intrauterine stress

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    Aims: Amniotic infection (AI) and preeclampsia (PE), which are commonly the reason for prematurity, inflict stress of different duration on immature fetuses. Whether chronic stress, as reflected by intrauterine growth retardation, influences the level of 17-OH progesterone (17-OHP), was not previously examined. Methods: We analyzed 17-OHP and TSH levels during neonatal screenings in the first hours of life of 90 premature infants born between 25 and 33weeks of gestation in infants with AI (n=37) or with PE (n=53). Control of acute stress parameters was derived from umbilical arterial cord blood pH and base excess (BE). Results: Mean 17-OHP levels of infants born to mothers with PE were 85.7nmol/L compared to 54.6nmol/L (P<0.001) in AI infants. 17-OHP was even higher when intrauterine growth restriction was present (99.8nmol/L). Antenatal steroids and mode of delivery did not significantly affect 17-OHP levels. Conclusions: Stress of relatively long duration, as in cases of PE, leads to a significant increase of 17-OHP level in preterm infants. The postnatal 17-OHP level may be considered as a measure for severity of intrauterine stress and might be used as an individualized indicator for earlier intensive car

    Creative music therapy for long-term neurodevelopment in extremely preterm infants: Results of a feasibility trial

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    AIM: We tested the feasibility of a future randomised clinical trial (RCT) in which Creative Music Therapy (CMT), a family-integrating individualised approach in neonatal care, could improve neurodevelopment in extremely preterm infants (EPTs). METHODS: In this feasibility trial, 12 EPTs received CMT, while the remaining 19 received standard neonatal care. Socio-demographic data and perinatal complications were compared between groups as risk factors. Bayley Scales of Infant and Toddler Development at 2-year follow-up (FU2) and KABC-II-Kaufman Assessment Battery for Children at 5-year follow-up (FU5) were analysed using the Mann-Whitney U-tests. RESULTS: Twenty-seven (87.1%) and 18 (58.1%) EPTs attended the FU2 and FU5 examination, respectively. The rate of neurodevelopmental risk factors at birth of the two groups was quite similar. While there was no difference in the FU2 outcomes between groups, there were higher values in the CMT group's Fluid-Crystallised Index of the KABC-II. CONCLUSION: Our results indicate neither a beneficial nor a detrimental effect of CMT on neurodevelopment at 2 years but a trend of improved cognitive outcomes at 5 years more similar to cognitive scores of term-born infants than of standard treatment EPTs. The findings favour an RCT but must be interpreted cautiously due to the reduced sample size and non-randomised design

    Vanadium-based polyoxometalate as new material for sodium-ion battery anodes

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    Affordable energy storage is crucial for a variety of technologies. One option is sodium-ion batteries (NIBs) for which, however, suitable anode materials are still a problem. We report on the application of a promising new class of materials, polyoxometalates (POMs), as an anode in NIBs. Specifically, Na6[V10O28]·16H2O is being synthesized and characterized. Galvanostatic tests reveal a reversible capacity of approximately 276 mA h g−1 with an average discharge potential of 0.4 V vs. Na/Na+, as well as a high cycling stability. The underlying mechanism is rationalized to be an insertion of Na+ in between the [V10O28]6− anions rather than an intercalation into a crystal structure; the accompanying reduction of V+V to V+IV is confirmed by X-ray Photoelectron Spectroscopy. Finally, a working full-cell set-up is presented with the POM as the anode, substantiating the claim that Na6[V10O28]·16H2O is a promising option for future high-performing sodium-ion batteries

    Studium, Berufswahl und Berufstätigkeit: Nürnberger Sozialwirte zwischen 1981 und 1994

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    In dem Beitrag wird der berufliche Verbleib der Nürnberger Sozialwirte anhand einer Befragung der Absolventen von 1991 bis 1994 untersucht. Studiumsgestaltung, Berufssuche und Bewerbungsverhalten sowie Aspekte der ausgeübten Berufstätigkeit und Studiengangsevaluation werden erfaßt. Es wird festgestellt, daß die Übergangsphase zwischen Studiumsende und Aufnahme eines Berufs durch verschiedene kulturelle, institutionale, situationale und personale Faktoren beeinflußt ist. Mehr als die Hälfte der Befragten konnte trotz der Probleme auf dem Stellenmarkt für Akademiker ihre Arbeitsmarktchancen nutzen und geht einer geregelten Tätigkeit nach. Zufriedenheit wird sowohl hinsichtlich des Studiums als auch hinsichtlich der Beschäftigungssituation festgestellt. Insgesamt deutet die Studie auf die Vorteile der Kombination mit wirtschaftswissenschaftlichen Inhalten hin und unterstreicht die positive Wirkung von Berufspraktika für die Berufseinmündung. (ICA
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