674 research outputs found

    Tolerability of inhaled N-chlorotaurine in the pig model

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>N-chlorotaurine, a long-lived oxidant produced by human leukocytes, can be applied in human medicine as an endogenous antiseptic. Its antimicrobial activity can be enhanced by ammonium chloride. This study was designed to evaluate the tolerability of inhaled N-chlorotaurine (NCT) in the pig model.</p> <p>Methods</p> <p>Anesthetized pigs inhaled test solutions of 1% (55 mM) NCT (n = 7), 5% NCT (n = 6), or 1% NCT plus 1% ammonium chloride (NH<sub>4</sub>Cl) (n = 6), and 0.9% saline solution as a control (n = 7), respectively. Applications with 5 ml each were performed hourly within four hours. Lung function, haemodynamics, and pharmacokinetics were monitored. Bronchial lavage samples for captive bubble surfactometry and lung samples for histology and electron microscopy were removed.</p> <p>Results</p> <p>Arterial pressure of oxygen (PaO<sub>2</sub>) decreased significantly over the observation period of 4 hours in all animals. Compared to saline, 1% NCT + 1% NH<sub>4</sub>Cl led to significantly lower PaO<sub>2 </sub>values at the endpoint after 4 hours (62 ± 9.6 mmHg vs. 76 ± 9.2 mmHg, p = 0.014) with a corresponding increase in alveolo-arterial difference of oxygen partial pressure (AaDO<sub>2</sub>) (p = 0.004). Interestingly, AaDO<sub>2 </sub>was lowest with 1% NCT, even lower than with saline (p = 0.016). The increase of pulmonary artery pressure (PAP) over the observation period was smallest with 1% NCT without difference to controls (p = 0.91), and higher with 5% NCT (p = 0.02), and NCT + NH<sub>4</sub>Cl (p = 0.05).</p> <p>Histological and ultrastructural investigations revealed no differences between the test and control groups. The surfactant function remained intact. There was no systemic resorption of NCT detectable, and its local inactivation took place within 30 min. The concentration of NCT tolerated by A549 lung epithelial cells <it>in vitro </it>was similar to that known from other body cells (0.25–0.5 mM).</p> <p>Conclusion</p> <p>The endogenous antiseptic NCT was well tolerated at a concentration of 1% upon inhalation in the pig model. Addition of ammonium chloride in high concentration provokes a statistically significant impact on blood oxygenation.</p

    New data about the suspensor of succulent angiosperms : ultrastructure and cytochemical study of the embryo-suspensor of Sempervivum arachnoideum L. and Jovibarba sobolifera (Sims) Opiz

    Get PDF
    The development of the suspensor in two species - Sempervivum arachnoideum and Jovibarba sobolifera - was investigated using cytochemical methods, light and electron microscopy. Cytological processes of differentiation in the embryo-suspensor were compared with the development of embryo-proper. The mature differentiated suspensor consists of a large basal cell and three to four chalazal cells. The basal cell produces haustorial branched invading ovular tissues. The walls of the haustorium and the micropylar part of the basal cell form the wall ingrowths typical for a transfer cells. The ingrowths also partially cover the lateral wall and the chalazal wall separating the basal cell from the other embryo cells. The dense cytoplasm filling the basal cell is rich in: numerous polysomes lying free or covering rough endoplasmic reticulum (RER), active dictyosomes, microtubules, bundles of microfilaments, microbodies, mitochondria, plastids and lipid droplets. Cytochemical tests (including proteins, insoluble polysaccharides and lipids are distributed in the suspensor during different stages of embryo development) showed the presence of high amounts of macromolecules in the suspensor cells, particularly during the globular and heart-shaped phases of embryo development. The protein bodies and lipid droplets are the main storage products in the cells of the embryo-proper. The results of Auramine 0 indicate that a cuticular material is present only on the surface walls of the embryo-proper, but is absent from the suspensor cell wall. The ultrastructural features and cytochemical tests indicate that in the two species - S. arachnoideum and J. sobolifera - the embryo-suspensor is mainly involved in the absorption and transport of metabolites from the ovular tissues to the developing embryo-proper

    Effects of anharmonic strain on phase stability of epitaxial films and superlattices: applications to noble metals

    Full text link
    Epitaxial strain energies of epitaxial films and bulk superlattices are studied via first-principles total energy calculations using the local-density approximation. Anharmonic effects due to large lattice mismatch, beyond the reach of the harmonic elasticity theory, are found to be very important in Cu/Au (lattice mismatch 12%), Cu/Ag (12%) and Ni/Au (15%). We find that is the elastically soft direction for biaxial expansion of Cu and Ni, but it is for large biaxial compression of Cu, Ag, and Au. The stability of superlattices is discussed in terms of the coherency strain and interfacial energies. We find that in phase-separating systems such as Cu-Ag the superlattice formation energies decrease with superlattice period, and the interfacial energy is positive. Superlattices are formed easiest on (001) and hardest on (111) substrates. For ordering systems, such as Cu-Au and Ag-Au, the formation energy of superlattices increases with period, and interfacial energies are negative. These superlattices are formed easiest on (001) or (110) and hardest on (111) substrates. For Ni-Au we find a hybrid behavior: superlattices along and like in phase-separating systems, while for they behave like in ordering systems. Finally, recent experimental results on epitaxial stabilization of disordered Ni-Au and Cu-Ag alloys, immiscible in the bulk form, are explained in terms of destabilization of the phase separated state due to lattice mismatch between the substrate and constituents.Comment: RevTeX galley format, 16 pages, includes 9 EPS figures, to appear in Physical Review

    The transition to parenthood following a history of childhood maltreatment: a review of the literature on prospective and new parents' experiences

    Get PDF
    Background: Becoming a parent is viewed as one of the most important transitions in one’s life. However, a history of childhood maltreatment may affect the adjustment to parenthood. Objective: The objective of this review was to synthesize the current evidence base to further our understanding of prospective and new parents’ experiences in the transition to parenthood (pregnancy to 2 years post-birth), in the context of having a childhood maltreatment history. Method: A scoping review of the literature was conducted using the following online databases: PubMed, PsycINFO, PsycNET, and Published International Literature of Traumatic Stress. Results: The findings were synthesized into a four-component theoretical framework, which included mental health of the parent, physical changes, parental view of the child, and view of the self as a parent. A total of 69 papers, including 181,537 participants (of whom 30,482 mothers and 235 fathers had maltreatment histories), investigated the transition to parenthood. The majority of the studies showed that parents with a maltreatment history may suffer from a range of mental health problems during the transition to parenthood, experience more negative physical changes, and have more negative views of their child (or children). However, they reported both positive and negative experiences regarding their identity as a parent. Conclusions: The findings suggest that maltreatment is a risk factor for a more challenging transition to parenthood. Experiences of fathers with maltreatment histories merit more attention, as do those of parents in low- and middle-income countries. Future directions should include predictors of positive experiences and the development of early interventions to improve outcomes for this population

    Parent-of-origin-specific allelic associations among 106 genomic loci for age at menarche.

    Get PDF
    Age at menarche is a marker of timing of puberty in females. It varies widely between individuals, is a heritable trait and is associated with risks for obesity, type 2 diabetes, cardiovascular disease, breast cancer and all-cause mortality. Studies of rare human disorders of puberty and animal models point to a complex hypothalamic-pituitary-hormonal regulation, but the mechanisms that determine pubertal timing and underlie its links to disease risk remain unclear. Here, using genome-wide and custom-genotyping arrays in up to 182,416 women of European descent from 57 studies, we found robust evidence (P < 5 × 10(-8)) for 123 signals at 106 genomic loci associated with age at menarche. Many loci were associated with other pubertal traits in both sexes, and there was substantial overlap with genes implicated in body mass index and various diseases, including rare disorders of puberty. Menarche signals were enriched in imprinted regions, with three loci (DLK1-WDR25, MKRN3-MAGEL2 and KCNK9) demonstrating parent-of-origin-specific associations concordant with known parental expression patterns. Pathway analyses implicated nuclear hormone receptors, particularly retinoic acid and γ-aminobutyric acid-B2 receptor signalling, among novel mechanisms that regulate pubertal timing in humans. Our findings suggest a genetic architecture involving at least hundreds of common variants in the coordinated timing of the pubertal transition

    PCA Beyond The Concept of Manifolds: Principal Trees, Metro Maps, and Elastic Cubic Complexes

    Full text link
    Multidimensional data distributions can have complex topologies and variable local dimensions. To approximate complex data, we propose a new type of low-dimensional ``principal object'': a principal cubic complex. This complex is a generalization of linear and non-linear principal manifolds and includes them as a particular case. To construct such an object, we combine a method of topological grammars with the minimization of an elastic energy defined for its embedment into multidimensional data space. The whole complex is presented as a system of nodes and springs and as a product of one-dimensional continua (represented by graphs), and the grammars describe how these continua transform during the process of optimal complex construction. The simplest case of a topological grammar (``add a node'', ``bisect an edge'') is equivalent to the construction of ``principal trees'', an object useful in many practical applications. We demonstrate how it can be applied to the analysis of bacterial genomes and for visualization of cDNA microarray data using the ``metro map'' representation. The preprint is supplemented by animation: ``How the topological grammar constructs branching principal components (AnimatedBranchingPCA.gif)''.Comment: 19 pages, 8 figure

    Psychological Well-Being of Parents of Very Young Children With Type 1 Diabetes – Baseline Assessment

    Get PDF
    Background: Type 1 diabetes in young children is a heavy parental burden. As part of pilot phase of the KIDSAP01 study, we conducted a baseline assessment in parents to study the association between hypoglycemia fear, parental well-being and child behavior. Methods: All parents were invited to fill in baseline questionnaires: hypoglycemia fear survey (HFS), WHO-5, Epworth Sleepiness Scale and Strength and Difficulties Questionnaire (SDQ). Results: 24 children (median age: 5-year, range 1-7 years, 63% male, mean diabetes duration: 3 ± 1.7 years) participated. 23/24 parents filled out the questionnaires. We found a higher score for the hypoglycemia fear behavior 33.9 ± 5.6 compared to hypoglycemia worry 34.6 ± 12.2. Median WHO-5 score was 16 (8 - 22) with poor well-being in two parents. Median daytime sleepiness score was high in five parents (>10). For six children a high total behavioral difficulty score (>16) was reported. Pro social behavior score was lower than normal in six children (<6). Parental well-being was negatively associated with HFS total (r = - 0.50, p <.05) and subscale scores (r = - 0.44, p <.05 for HFS-Worry and HFS-Behavior), child behavior (r = - 0.45, p = .05) and positively with child age and diabetes duration (r = 0.58, p <.01, r = 0.6, p <.01). HFS, parental well-being nor daytime sleepiness are associated with the HbA1c. Conclusion: Regular screening of parental well-being, hypoglycemia fear and child behavior should be part of routine care to target early intervention
    corecore