Safety and Feasibility of Skin-to-Skin Contact in the Delivery Room for High-Risk Cardiac Neonates.

Early skin-to-skin contact (SSC), beginning in the delivery room, provides myriad health benefits for mother and baby. Early SSC in the delivery room is the standard of care for healthy neonates following both vaginal and cesarean delivery. However, there is little published evidence on the safety of this practice in infants with congenital anomalies requiring immediate postnatal evaluation, including critical congenital heart disease (CCHD). Currently, the standard practice following delivery of infants with CCHD in many delivery centers has been immediate separation of mother and baby for neonatal stabilization and transfer to a different hospital unit or a different hospital altogether. However, most neonates with prenatally diagnosed congenital heart disease, even those with ductal-dependent lesions, are clinically stable in the immediate newborn period. Therefore, we sought to increase the percentage of newborns with prenatally diagnosed CCHD who are born in our regional level II-III delivery hospitals who receive mother-baby SSC in the delivery room. Using quality improvement methodology, through a series of Plan-Do-Study-Act cycles we successfully increased mother-baby skin-to-skin contact in the delivery room for eligible cardiac patients born across our city-wide delivery hospitals from a baseline 15% to greater than 50%.

Adsorption of sodium dodecylsulfate on single-walled carbon nanotubes characterised using small-angle neutron scattering.

Aqueous dispersions of single-walled carbon nanotubes are often made using sodium dodecylsulfate (SDS), which adsorbs to the nanotube surface to stabilise them. Despite SDS being commonly used with single-walled carbon nanotubes, there is no consensus on the structure of the adsorbed layer. Small-angle neutron and X-ray scattering results reported here show that the data can be fitted to a relatively simple core-shell cylinder model, consistent with a polydisperse nanotube core of radius 10Å, surrounded by an adsorbed surfactant layer of thickness 18Å and volume fraction of 0.5. This is consistent with small nanotube bundles surrounded by an adsorbed layer of extended SDS molecules.

Adsorption of F127 onto single-walled carbon nanotubes characterized using small-angle neutron scattering.

Aqueous single-walled carbon nanotube dispersions are often made using polymers from the pluronic family of amphiphilic block copolymers; however, relatively few studies have been conducted using small-angle neutron scattering techniques to discover the mechanism by which they act. SANS results reported here show that a relatively simple core-shell cylinder model can be used to fit data successfully at different contrasts. The results across all contrasts showed that the best fit gave an inner nanotube radius of 10 Å, corresponding to small nanotube bundles with a small amount of water present (20%), and a polydisperse adsorbed layer thickness of 61 Å, with a water content of 94% in the adsorbed layer. The data fitting is thus consistent with a small SWCNT bundle surrounded by an extended and water-swollen F127 adsorbed layer. Comparing the scattering from F127/SWCNT at different contrasts, it has been found that the polymer-decorated SWCNTs are contrast matched at a D2O/H2O volume ratio of 0.36:0.64, corresponding to a scattering-length density of 1.92 × 10(-6) Å(-2).

The effect of size ratio on the sphere structure factor in colloidal sphere-plate mixtures.

Binary mixtures of colloidal particles of sufficiently different sizes or shapes tend to demix at high concentration. Already at low concentration, excluded volume interactions between the two species give rise to structuring effects. Here, a new theoretical description is proposed of the structure of colloidal sphere-plate mixtures, based on a density expansion of the work needed to insert a pair of spheres and a single sphere in a sea of them, in the presence or not of plates. The theory is first validated using computer simulations. The predictions are then compared to experimental observations using silica spheres and gibbsite platelets. Small-angle neutron scattering was used to determine the change of the structure factor of spheres on addition of platelets, under solvent contrast conditions where the platelets were invisible. Theory and experiment agreed very well for a platelet/sphere diameter ratio D∕d = 2.2 and reasonably well for D∕d = 5. The sphere structure factor increases at low scattering vector Q in the presence of platelets; a weak reduction of the sphere structure factor was predicted at larger Q, and for the system with D∕d = 2.2 was indeed observed experimentally. At fixed particle volume fraction, an increase in diameter ratio leads to a large change in structure factor. Systems with a larger diameter ratio also phase separate at lower concentrations.

Structure of colloidal sphere-plate mixtures.

In addition to containing spherical pigment particles, coatings usually contain plate-like clay particles. It is thought that these improve the opacity of the paint film by providing an efficient spacing of the pigment particles. This observation is counterintuitive, as suspensions of particles of different shapes and sizes tend to phase separate on increase of concentration. In order to clarify this matter a model colloidal system is studied here, with a sphere-plate diameter ratio similar to that found in paints. For dilute suspensions, small angle neutron scattering revealed that the addition of plates leads to enhanced density fluctuations of the spheres, in agreement with new theoretical predictions. On increasing the total colloid concentration the plates and spheres phase separate due to the disparity in their shape. This is in agreement with previous theoretical and experimental work on colloidal sphere-plate mixtures, where one particle acts as a depleting agent. The fact that no large scale phase separation is observed in coatings is ascribed to dynamic arrest in intimately mixed, or possibly micro-phase separated structures, at elevated concentration.

Adolescent use of school-based health centers and high school dropout.

OBJECTIVE: To determine the association between use of school-based health centers (SBHCs) and school dropout. DESIGN: Quasi-experimental longitudinal analysis of a retrospective student cohort, with SBHC use as the independent variable. We statistically controlled for dropout risk and used propensity score regression adjustment to control for several factors associated with SBHC use. SETTING: Integrated database from an urban public school district (academic outcomes) and department of public health (SBHC use). PARTICIPANTS: District-enrolled students in their first semester of ninth grade in 2005 (N = 3334), followed up through their anticipated on-time graduation semester of 12th grade in 2009. Students were divided into 4 groups: never used (47%); low use (23%); moderate use (20%); and high users (10%). OUTCOME MEASURE: Time to nongraduation (described as dropout). RESULTS: Low to moderate SBHC use (0.125-2.5 visits per semester) was associated with a 33% reduction in dropout compared with non-SBHC users. The high-use group (>2.5 visits per semester) did not have dropout rates that differed from nonusers. For SBHC users who did drop out, dropout occurred approximately 1 semester later than nonusers. Exploratory analyses revealed that the association between SBHC use and prevention of dropout was greatest for higher-risk students. CONCLUSIONS: This study found an association between low to moderate SBHC use and reductions in dropout for high school students in an urban school district, especially for students at higher risk for dropout. This study supports the theory that benefits of SBHCs extend beyond managing physical and mental health needs to include academic outcomes.

Impact of School-Based Health Center use on academic outcomes.

PURPOSE: The purpose of this study was twofold: (1) to examine the effects of School-Based Health Center (SBHC) use on academic outcomes for high school students, using a well-controlled, longitudinal model, and (2) to examine whether SBHC medical and mental health service use differentially impacts academic outcomes. METHODS: Analyses used a latent variable growth curve modeling approach to examine longitudinal outcomes over five school semesters for ninth grade SBHC users and nonusers from Fall 2005 to Fall 2007 (n = 2,306). Propensity score analysis was used to control for self-selection factors in the SBHC user and nonuser groups. RESULTS: Results indicated a significant increase in attendance for SBHC medical users compared to nonusers. Grade point average increases over time were observed for mental health users compared to nonusers. Discipline incidents were not found to be associated with SBHC use. CONCLUSIONS: SBHC use was associated with academic improvements over time for a high-risk group of users. The moderating effect of type of use (medical and mental health) reinforces the importance of looking at subgroups when determining the impact of SBHC use on outcomes.

Novel self-assembly of amphiphilic copolymers into nanotubes: characterization by small-angle neutron scattering.

The self-assembly into nanotubes in solution of an amphiphilic copolymer is characterized by small-angle neutron scattering (SANS). This study confirmed the shape and the size of the tubular association and the 3-D association of the tubes predicted by molecular orbital theory. Moreover, the characterization of the stability of the association has revealed that the addition of a very small amount of salt to the solution increases the size of the association. When more salt is added, the size of the association decreases, and the structure is altered. The association was found to be independent of temperature and therefore is very stable.

Interaction between a novel gemini surfactant and cyclodextrin: NMR and surface tension studies.

The interaction between cyclodextrins, hydroxypropyl-beta-cyclodextrin (HPbetaCD), and hydroxypropyl-gamma-cyclodextrin (HPgammaCD) and a novel type of nonionic surfactant synthesized from a fatty acid has been investigated. The so-called nonionic heterogemini surfactant (NIHG750) contains two hydrophobic groups and two hydrophilic groups, composed of one monomethyl ethylene glycol and one secondary OH group, CH(3)(CH(2))(7)-CH[OH]-CH[O(CH(2)CH(2)O)(16)CH(3)]-(CH(2))(7)CN. Surface tension studies indicate that micelles form in NIHG750 systems in both the presence and the absence of small quantities (molar ratio (HPbetaCD:NIHG750) approximately 2) of cyclodextrin (HPbetaCD or HPgammaCD). This gives NIHG surfactants an advantage compared to single-tailed nonionic surfactants, which generally lose their ability to micellize at much lower additions of cyclodextrins. However, the interaction between HPbetaCD and NIHG750 results in a disruption of the micellar aggregates at higher levels of cyclodextrin. In the dilute systems (C(NIHG750)<0.1% (w/w) approx) prolate-shaped mixed aggregates (HPbetaCD and NIHG750) form, with a short and a long axis of the order of 8-9 and 17-20 A, respectively. These gradually aggregate into micellar-like structures at higher concentrations. In the aqueous bulk phase HPbetaCD interacts mainly with the hydrophobic part of NIHG750, but both NMR and surface tension measurements indicate that an interaction with the hydrophilic part of NIHG750, as well, may exist. This interaction results in a better packing of NIHG750 at air-water interfaces. However, at elevated temperatures results from turbidity measurements indicate that NIHG750 and HPbetaCD interact mainly through the hydrophilic part of the surfactant; a decrease in the cloud point temperature is observed. The interaction of the larger cavity molecule, HPgammaCD, with NIHG750, on the other hand, seems to be relatively weak. The interaction, when present, most probably takes place through inclusion of the hydrophilic EO part of NIHG750. The results suggest that HPgammaCD in combination with NIHG750 is a better solubilizing system than with HPbetaCD.

Gay, lesbian, and bisexual youth and young adults: social support in their own words.

Perceived social support was explored in a qualitative study of 17 gay, lesbian, and bisexual youth and young adults from a Seattle-based sexual minority youth drop-in center. The participants were interviewed in person with an open-ended question format to describe, in their own words, perceived social support they received as sexual minorities. Support was organized into four types, those fulfilling concrete, emotional, financial, or informational needs. Content analysis revealed several themes of support tailored to the specialized needs participants had as sexual minorities: locating parental figures among other gays and lesbians, parental reactions to learning of the youths' sexual orientation, the ability to reciprocate support, and finding supporters who introduced the youth to the gay, lesbian, and bisexual community. Non-family members were found to be more supportive than family members, particularly regarding informational support. Sexual minorities were perceived as more supportive than non-sexual minorities. Understanding the process and significance of acquiring a sense of community from which youth may garner continued support may present an avenue for intervention among social service providers. Additional implications for practice and research are also discussed.

Intraventricular perineurioma: case report.

OBJECTIVE AND IMPORTANCE: Perineurioma, a rare benign nerve sheath neoplasm occurring in either an intraneural or soft tissue form, has never been reported to arise in the central nervous system. CLINICAL PRESENTATION: We describe the clinical, radiological, and pathological features of a perineurioma arising in the choroid plexus of the third ventricle in a 65-year-old woman and causing obstructive hydrocephalus. INTERVENTION: The lesion, apparently unassociated with a nerve, was gross totally resected by frontal craniotomy using a left-sided transcallosal approach. Short-term follow-up showed no evidence of recurrence. CONCLUSION: Perineurioma of the variety found in soft tissue may occur in the central nervous system, wherein it shows the typical light microscopic, immunohistochemical (epithelial membrane antigen- and Collagen IV-positive, S-100 protein-negative), and ultrastructural (pinocytotic vesicles, discontinuous basement membrane) features.

The use of block copolymer stabilizers for controlling dispersion stability.

The role of block copolymers in stabilizing colloidal dispersions against flocculation or coalescence is discussed in terms of the detailed structure of the interface. Both particulate dispersions and liquid/liquid interfaces are used as examples. Two novel experimental methods are introduced, small-angle neutron scattering and neutron reflection. Comparison with the Scheutjens Fleer theory for block copolymers is also presented. Strategies for the optimum design of the stabilizing polymer are introduced.

Planetree health information services: public access to the health information people want.

In July 1981, the Planetree Health Resource Center opened on the San Francisco campus of California Pacific Medical Center (Pacific Presbyterian Medical Center). Planetree was founded on the belief that access to information can empower people and help them face health and medical challenges. The Health Resource Center was created to provide medical library and health information resources to the general public. Over the last twelve years, Planetree has tried to develop a consumer health library collection and information service that is responsive to the needs and interests of a diverse public. In an effort to increase accessibility to the medical literature, a consumer health library classification scheme was created for the organization of library materials. The scheme combines the specificity and sophistication of the National Library of Medicine classification scheme with the simplicity of common lay terminology.

Peroxynitrite-induced luminol chemiluminescence.

Vascular endothelial cells, smooth muscle cells, macrophages, neutrophils, Kupffer cells and other diverse cell types generate superoxide (O2.-) and nitric oxide (.NO), which can react to form the potent oxidant peroxynitrite anion (ONOO-). Peroxynitrite reacted with luminol to yield chemiluminescence which was greatly enhanced by bicarbonate. The quantum chemiluminescence yield of the ONOO- reaction with luminol in bicarbonate was approx. 10(-3). Chemiluminescence was superoxide dismutase-inhibitable, indicating that O2.- was a key intermediate for chemiexcitation. O2.- appears to be formed secondarily to the reaction of a bicarbonate-peroxynitrite complex with luminol, yielding luminol radical and O2.-. Luminol radical reacts with O2.- to form the unstable luminol endoperoxide, which follows the light-emitting pathway. Neither .NO nor O2.- alone were capable of directly inducing significant luminol chemiluminescence in our assay systems. These results suggest that ONOO- can be a critical unrecognized mediator of cell-derived luminol chemiluminescence reported in previous studies. In addition, it is shown that bicarbonate can participate in secondary oxidation reactions after reacting with ONOO-.

Reaction of xanthine oxidase-derived oxidants with lipid and protein of human plasma.

Xanthine oxidase and purines have recently been detected in the circulation during acute viral infection and following hepatotoxicity and shock. Reactions of xanthine oxidase-generated oxidants with human plasma or bovine serum albumin (BSA) and egg phosphatidylcholine (PC) liposomes have been studied by measuring protein sulfhydryl oxidation and two markers of free radical-mediated lipid peroxidation, thiobarbituric acid reactive substances (TBARS) and conjugated dienes. Plasma incubated with 5 mU/ml xanthine oxidase (XO) and 0.5 mM hypoxanthine (Hx) for 2 h at 37 degrees C had 25-53% oxidation of sulfhydryl groups, with greater than 80% of the oxidation occurring during the first 20 min of the reaction. Concentrations of BSA similar to those present in serum, when exposed to XO/Hx-mediated oxidative stress, showed an even greater decrease in sulfhydryl concentration than that of plasma. No significant increase in plasma TBARS and conjugated dienes was observed during the 2-h incubation period in the presence of XO. Egg PC liposomes, suspended to a plasma phospholipid-equivalent concentration, showed a minor increase in TBARS and conjugated dienes under similar XO/Hx incubation conditions. In the presence of 0.23 mM BSA, lipid peroxidation was completely inhibited. A similar inhibition of lipid peroxidation was induced by cysteine but not by uric acid. Electrophoretic and arsenite-mediated sulfur reduction analysis revealed that BSA was oxidized beyond the disulfide form, with sulfenic acid formed during the initial period of oxidation. Protein sulfhydryls served as sacrificial antioxidants, preventing plasma lipid peroxidation, as well as being targets for oxidative damage. Plasma protein thiol oxidation was determined to be a more sensitive and specific indication of oxidant stress to the vascular compartment than assessment of lipid oxidation byproducts.