Congenital posterolateral diaphragmatic hernia : pathophysiological studies and clinical picture

Congenital diaphragmatic hernias are classified according to the location of the defect: posterolateral hernia with or without a sac (Bochdalek-type), parasternal hernia through the foramen of Morgagni, central hernia, and diaphragmatic eventration. The so-called hiatal hernia has a different pathophysiology and a different clinical presentation. Posterolateral defects account for 85% of congenital diaphragmatic herniasY Left-sided posterolateral defects occur eight times more frequently than right-sided defects in the neonatal period. Bilateral defects are rare and estimated at 3 to 5%.3 Children at the highest risk of dying are they who are symptomatic in the delivery room or within six hours after birth.' The mortality rate reported in this group ranges from 40 to 50%." Conversely, those who do not develop respiratory failure in the first 24 hours of life have an almost 100% chance of survival. In contrast to other major congenital anomalies the mortality due to congenital posterolateral diaphragmatic hernia remains high despite improvements in neonatal intensive care and pediatric surgery.'~ The main reason is that pulmonary hypoplasia and pulmonary hypertension form the pathophysiological basis for the clinical picture of respiratory distress and right-to-left shunting that frustrates so many clinicians responsible for newborns with a diaphragmatic defect. This thesis presents the research into clinical aspects of congenital posterolateral diaphragmatic hernia related to pulmonary hypoplasia and pulmonary hypertension; the pathophysiological background of these disorders was studied in an animal model. The clinical studies were all carried out in the Pediatric Surgical Intensive Care Unit of the Sophia Children's Hospital. The animal model was developed by TenBrinck and coworkers in the Laboratory of Experimental Surgery of the Erasmus University in Rotterdam.' In this model congenital diaphragmatic hernia is induced in fetal rats by means of administering a single dose of Nitrofen (2,4-dichlorophenylp- nitrophenyl ether) on the lOth day of gestation. The model interferes with lung development in an early stage, thus providing the opportunity to study several aspects of lung development in relation to both ventilatory capacity and pulmonary vascular reactivity. The results of the conducted studies, as they have been reported and discussed in papers either published or accepted by international journals, form the core of this thesis. These papers are preceded by a review of the literature focussed on historical aspects, clinical picture and normal and abnormal lung development. They are followed by a concluding chapter in which changing concepts concerning pathogenesis and treatment are discusse

Formal vs self-organised knowledge systems: a network approach

In this work we consider the topological analysis of symbolic formal systems in the framework of network theory. In particular we analyse the network extracted by Principia Mathematica of B. Russell and A.N. Whitehead, where the vertices are the statements and two statements are connected with a directed link if one statement is used to demonstrate the other one. We compare the obtained network with other directed acyclic graphs, such as a scientific citation network and a stochastic model. We also introduce a novel topological ordering for directed acyclic graphs and we discuss its properties in respect to the classical one. The main result is the observation that formal systems of knowledge topologically behave similarly to self-organised systems.Comment: research pape

Cardiopulmonary resuscitation in paediatric intensive care patients

Abstract To identify the success of cardiopulmonary resuscitation in the paediatric ICU patient we undertook a retrospective study in an 11-bed medical and a 14-bed surgical paediatric ICU over a 32-month period. Thirtyfour patients suffered an arrest in the ICU. Only 4 patients could be resuscitated successfully; 1 died after 24 h. Of the 3 long-term survivors 1 suffered from severe neurologic sequelae. All patients were in CCS classes III or IV. All but 3 patients had PSI scores >8. The decision to resuscitate or to withhold therapy in individual patients who are deteriorating in the course of a critical, preceding illness should not be based on the risk index of these scoring systems. Both medical and ethical considerations should be guidelines in the process of decision-making

Critical behavior of the planar magnet model in three dimensions

We use a hybrid Monte Carlo algorithm in which a single-cluster update is combined with the over-relaxation and Metropolis spin re-orientation algorithm. Periodic boundary conditions were applied in all directions. We have calculated the fourth-order cumulant in finite size lattices using the single-histogram re-weighting method. Using finite-size scaling theory, we obtained the critical temperature which is very different from that of the usual XY model. At the critical temperature, we calculated the susceptibility and the magnetization on lattices of size up to $42^3$. Using finite-size scaling theory we accurately determine the critical exponents of the model and find that $\nu$=0.670(7), $\gamma/\nu$=1.9696(37), and $\beta/\nu$=0.515(2). Thus, we conclude that the model belongs to the same universality class with the XY model, as expected.Comment: 11 pages, 5 figure

Parental depression and child well-being: Young children's self-reports helped addressing biases in parent reports

Objectives Effects of maternal and paternal depression on child development are typically evaluated using parental reports of child problems. Yet, parental reports may be biased. Methods In a population-based cohort, parents reported lifetime depression (N = 3,178) and depressive symptoms (N = 3,131). Child emotional and behavioral problems were assessed at age 6 years by child self-report using the Berkeley Puppet Interview, by mother report using the Child Behavior Checklist (CBCL), and at age 3 years by father and mother reported CBCLs. Results Both maternal and paternal depression was associated with more child problems. Associations were of similar strength if child problems were obtained by self-reports. However, if parents reported about their own depression or depressive symptoms and about their child's problems, estimates were generally stronger for associations with the reporting parent's depression as the determinant. For instance, if mothers reported child emotional problems, associations were stronger for maternal (B = 0.27; 95% confidence interval (CI) = 0.19, 0.35) than for paternal lifetime depression (B = 0.12; 95% CI = 0.02, 0.21; P-value for difference = 0.02). Conclusion Depression of mothers and fathers affects young children's well-being. However, if parents reported about their own depression and about child problems, associations were inflated. To accurately estimate effects of parental depression, multiple-source data including young children's perspectives must be considered

Value of urinary N-methylhistamine measurements m childhood mastocytosis

Background: Histamine is an indicator of mast cell activation. N- methylhistamine (NMH) is a metabolite of histamine that can be measured in urine. Objective: Our purpose was to assess the usefulness of determining urinary NMH levels for the diagnosis and follow-up of patients with mastocytosis. Methods: Urinary NMH levels were determined in 44 patients and were correlated with disease activity and extension. The control group consisted of 24 children without mastocytosis or any other skin disease. Results: A significant negative correlation was found between NMH and age in patients with active mastocytosis and in the control group. Adjusted for age, NMH values were significantly higher in patients with active mastocytosis. There was a significant difference in NMH values between patients with diffuse cutaneous mastocytosis, patients with active urticaria pigmentosa, and patients with active mastocytomas. However, there was a substantial overlap of NMH values in the different subgroups. Conclusion: Urinary NMH values tend to decrease with age. Urinary NMH values correlated with the extent and the activity of the disease. High NMH values suggest more extensive involvement

Breast-Feeding Modifies the Association of PPARγ2 Polymorphism Pro12Ala With Growth in Early Life: The Generation R Study

OBJECTIVE-We examined whether the PPARyγ2 Ala12 allele influences growth in early life and whether this association is modified by breast-feeding. RESEARCH DESIGN AND METHODS-This study was embedded in the Generation R Study, a prospective cohort study from early fetal life onward. PPARy2 was genotyped in DNA obtained from cord blood samples in 3,432 children. Information about breast-feeding was available from questionnaires. Weight, head circumference, and femur length were repeatedly measured in second and third trimesters of pregnancy, at birth, and at the ages of 1.5, 6, 11, 14, and 18 months. RESULTS-Genotype frequency distribution was 77.6% (Pro12Pro), 20.7% (Pro12Ala), and 1.7% (Ala12Ala). Growth rates in weight from second trimester of pregnancy to 18 months were higher for Pro12Ala and Ala12Ala than for Pro12Pro carriers (differences 1.11 g/week [95% CI 0.47-1.74] and 2.65 g/week [0.45-4.87], respectively). We found an interaction between genotype and breast-feeding duration (P value for interaction nths, PPARy2 Pro12Ala was not associated with growth rate. When breast-feeding duration was <2 months or 2-4 months, growth rate was higher in Ala12Ala than Pro12Pro carriers (differences 9.80 g/week [3.97-15.63] and 6.32 g/week [-1.04 to 13.68], respectively). CONCLUSIONS-The PPAR7gamma;2 Ala12 allele is associated with an increased growth rate in early life. This effect may be influenced by breast-feeding duration. Further studies should replicate these findings, identify the underlying mechanisms, and assess whether these effects persist into later life

Si ion implantation-induced damage in fused silica probed by variable-energy positrons

Samples of synthetic fused silica have been implanted at room temperature with silicon ions of energy 1.5 MeV. Fluences ranged from 1011 to 1013 cm−2. Samples were probed using variable‐energy positron annihilation spectroscopy. The Doppler‐broadening S parameter corresponding to the implanted region decreased with increasing fluence and saturated at a fluence of 1013 cm−2. It is shown that the decrease in the S parameter is due to the suppression of positronium (Ps) which is formed in the preimplanted material, due to the competing process of implantation‐induced trapping of positrons. In order to satisfactorily model the positron data it was necessary to account for positron trapping due to defects created by both electronic and nuclear stopping of the implanted ions. Annealing of the 1013 cm−2 sample resulted in measurable recovery of the preimplanted S parameter spectrum at 350 °C and complete recovery to the preimplanted condition at 600 °C. Volume compaction was also observed afterimplantation. Upon annealing, the compaction was seen to decrease by 75%

Exploring the relation of harsh parental discipline with child emotional and behavioral problems by using multiple informants. The generation R study

Parental harsh disciplining, like corporal punishment, has consistently been associated with adverse mental health outcomes in children. It remains a challenge to accurately assess the consequences of harsh discipline, as researchers and clinicians generally rely on parent report of young children's problem behaviors. If parents rate their parenting styles and their child's behavior this may bias results. The use of child self-report on problem behaviors is not common but may provide extra information about the relation of harsh parental discipline and problem behavior. We examined the independent contribution of young children's self-report above parental report of emotional and behavioral problems in a study of maternal and paternal harsh discipline in a birth cohort. Maternal and paternal harsh discipline predicted both parent reported behavioral and parent reported emotional problems, but only child reported behavioral problems. Associations were not explained by pre-existing behavioral problems at age 3. Importantly, the association with child reported outcomes was independent from parent reported problem behavior. These results suggest that young children's s