Daily salivary cortisol patterns in midlife women with hot flashes.

OBJECTIVE: Diurnal salivary cortisol patterns in healthy adults are well established but have not been studied in midlife women with hot flashes. We hypothesized that frequent hot flashes are associated with aberrant cortisol patterns similar to sleep-deficient individuals. DESIGN: Cross-sectional. PARTICIPANTS: A total of 306 women, ages 40-62, randomized to a behavioural intervention for hot flashes. MEASUREMENTS: Baseline comparisons of cortisol geometric means (nmol/l) from four daily time points averaged over two consecutive days plus other calculated cortisol measures were made between groups defined by baseline: (i) mean daily hot flash frequency tertile (≤5·5, N = 103; >5·5-8·8, N = 103; >8·8, N = 100) and (ii) selected characteristics. Repeated-measures linear regression models of log-transformed cortisol evaluated group differences, adjusting for covariates. RESULTS: Women were 67% White and 24% African American, with 7·6 (SD 3·9) hot flashes per day. Salivary cortisol geometric means (nmol/l) among all women were as follows: 75·0 (SD 44·8) total, 8·6 (SD 5·6) wake, 10·0 (SD 7·5) wake +30 min, 3·7 (SD 3·3) early afternoon and 1·6 (SD 1·8) bedtime. Wake + 30-minute values showed an 18% median rise from wake values (interquartile range -24 to 96%), and means varied by hot flash frequency tertile, from lowest to highest: 11·4(SD 7·3), 10·3 (SD 6·5) and 8·6 (SD 7·8), respectively, P = 0·003. Beside the early afternoon value (P = 0·02), cortisol values did not vary by hot flash frequency. CONCLUSION: Taken together, these findings suggest that high frequency of moderate-to-severe hot flashes may be associated with subtle abnormalities in cortisol concentrations - a pattern consistent with chronic sleep disturbance.

Student outcomes of the healing web: evaluation of a transformative model for nursing education.

The Healing Web is a transformative nursing model, bridging gaps between nursing education and practice, baccalaureate and associate degree education, and public and private educational institutions. It is an educational prototype in which nursing students experience collaborative clinical practice in a differentiated practice model. Based on the Healing Web framework, it was hypothesized that the educational partnership model would influence specific student competencies (i.e., caring abilities, leadership skills, assertiveness, and professional nursing behaviors). Students in the Healing Web program scored higher in caring knowing, caring courage, leadership, and assertiveness than their counterparts who participated in traditional clinical experiences. Students identified collaboration, partnership with students and staff, and learning to value different nursing roles as primary benefits of the experience. Findings support the contribution of Healing Web experiences to selected student outcomes, but the research is limited by instrumentation, small numbers, and the question of adequate "dosage." Future research will emphasize qualitative methods to explicate significant concepts more completely.

Design of a composite biomaterial system for tissue engineering applications.

Biomaterials that regulate vascularized tissue formation have the potential to contribute to new methods of tissue replacement and reconstruction. The goal of this study was to develop a porous, degradable tissue engineering scaffold that could deliver multiple growth factors and regulate vessel assembly within the porous structure of the material. Porous hydrogels of poly(ethylene glycol)-co-(L-lactic acid) (PEG-PLLA) were prepared via salt leaching. The degradation time of the hydrogels could be controlled between 1 and 7 weeks, based on hydrogel composition. Fibrin was incorporated into the interconnected pores of the hydrogels to promote neovascularization and as a reservoir for rapid (<5 days) growth factor delivery. Poly(lactic-co-glycolic acid) (PLGA) microspheres were incorporated into the degradable polymeric hydrogel scaffold to allow sustained (>30 days) growth factor delivery. Fibroblast growth factor-1 (FGF-1) and platelet-derived growth factor-BB (PDGF-BB) were delivered from the system owing to their roles in the promotion of angiogenesis and vascular stabilization, respectively. Hydrogels tested in vivo with a subcutaneous implantation model were selected based on the results from in vitro degradation and growth factor release kinetics. Dual growth factor delivery promoted significantly more tissue ingrowth in the scaffold compared with blank or single growth factor delivery. The sequential delivery of FGF-1 following PDGF-BB promoted more persistent and mature blood vessels. In conclusion, a biomaterials system was developed to provide structural support for tissue regeneration, as well as delivery of growth factors that stimulate neovascularization within the structure prior to complete degradation.

Evaluation of MMP substrate concentration and specificity for neovascularization of hydrogel scaffolds.

Controlled vascular response in scaffolds following implantation remains a significant clinical challenge. A critical biomaterial design criterion is the synchronization of the rates of scaffold degradation and vascularized tissue formation. Matrix metalloproteinases (MMPs) are key enzymes that regulate neovascularization and extracellular matrix remodelling. Synthetic protease-sensitive hydrogels offer controllable environments for investigating the role of matrix degradation on neovascularization. In this study, PEG hydrogels containing MMP-sensitive peptides with increased catalytic activity for MMPs expressed during neovascularization were investigated. Scaffolds were functionalized with MMP-2-, MMP-14- or general collagenase-sensitive peptides and with varying peptide concentration using crosslinkers containing one (SSite) or multiple (TSite) repeats of each protease-sensitive sequence. Increasing peptide concentration enhanced the degradation kinetics of scaffolds functionalized with MMP-specific sequences while 80% of the collagenase-sensitive scaffolds remained upon exposure to MMP-2 and MMP-14. In vitro neovascularization was consistent with in vivo tissue invasion with significantly increased invasion occurring within SSite MMP-specific as compared to collagenase-sensitive hydrogels and with further invasion in TSite as compared to SSite hydrogels regardless of peptide specificity. All scaffolds supported in vivo neovascularization; however, this was not dependent on peptide specificity. These findings demonstrate that peptide concentration and specificity regulate in vivo scaffold degradation, neovascularization and matrix remodelling.

An initial evaluation of analyser-based phase-contrast X-ray imaging of carotid plaque microstructure.

Carotid artery plaque instability can result in rupture and lead to ischaemic stroke. Stability of plaques appears to be a function of composition. Current non-invasive imaging techniques are limited in their ability to classify distinct histological regions within plaques. Phase-contrast (PC) X-ray imaging methods are an emerging class of techniques that have shown promise for identifying soft-tissue features without use of exogenous contrast agents. This is the first study to apply analyser-based X-ray PC imaging in CT mode to provide three-dimensional (3D) images of excised atherosclerotic plaques. The results provide proof of principle for this technique as a promising method for analysis of carotid plaque microstructure. Multiple image radiography CT (MIR-CT), a tomographic implementation of X-ray PC imaging that employs crystal optics, was employed to image excised carotid plaques. MIR-CT imaging yields three complementary images of the plaque's 3D X-ray absorption, refraction and scatter properties. These images were compared with histological sections of the tissue. X-ray PC images were able to identify the interface between the plaque and the medial wall. In addition, lipid-rich and highly vascularized regions were visible in the images as well as features depicting inflammation. This preliminary research shows MIR-CT imaging can reveal details about plaque structure not provided by traditional absorption-based X-ray imaging and appears to identify specific histological regions within plaques. This is the first study to apply analyser-based X-ray PC imaging to human carotid artery plaques to identify distinct soft-tissue regions.

Age-related changes in motor subtle signs among girls and boys with ADHD.

OBJECTIVE: To examine differences in age-related improvement in motor speed and neurologic subtle signs (overflow and dysrhythmia) among boys and girls with and without attention-deficit hyperactivity disorder (ADHD). METHOD: Diagnosis of ADHD was determined by structured parent interview and administration of ADHD-specific and broad behavior rating scales. Motor function was assessed using the revised Physical and Neurological Assessment of Subtle Signs. Three primary outcome variables were obtained: 1) total time, 2) total overflow, and 3) total dysrhythmia. Effects of age, group, and sex were assessed. RESULTS: Both control and ADHD groups showed improvement on timed tasks with age; however, controls were consistently faster across the age span. Controls and girls with ADHD showed steady age-related reduction of overflow and dysrhythmia, whereas boys with ADHD had little improvement in these signs through age 14 years. CONCLUSION: Results indicated that girls with attention-deficit hyperactivity disorder (ADHD) performed similarly to age-matched controls on a quantified motor examination. These results parallel patterns of findings from neuroimaging studies, in which neurologic anomalies in areas related to motor control are present in boys with ADHD, but more equivocal in girls with ADHD. Sex-related differences observed in children with ADHD likely extend beyond symptom presentation to development of motor control, and are likely related to earlier brain maturation in girls.

Dyspraxia in autism: association with motor, social, and communicative deficits.

Impaired performance of skilled gestures, referred to as dyspraxia, is consistently reported in children with autism; however, its neurological basis is not well understood. Basic motor skill deficits are also observed in children with autism and it is unclear whether dyspraxia observed in children with autism can be accounted for by problems with motor skills. Forty-seven high-functioning children with an autism spectrum disorder (ASD), autism, or Asperger syndrome (43 males, four females; mean age 10y 7m [SD 1y 10m], mean Full-scale IQ (FSIQ) 99.4 [SD 15.9]), and 47 typically developing (TD) controls (41 males, six females; mean age 10y 6m [SD 1y 5m], mean FSIQ 113.8 [SD 12.3], age range 8-4y) completed: (1) the Physical and Neurological Assessment of Subtle Signs, an examination of basic motor skills standardized for children, and (2) a praxis examination that included gestures to command, to imitation, and with tool-use. Hierarchical regression was used to examine the association between basic motor skill performance (i.e. times to complete repetitive limb movements) and praxis performance (total praxis errors). After controlling for age and IQ, basic motor skill was a significant predictor of performance on praxis examination. Nevertheless, the ASD group continued to show significantly poorer praxis than controls after accounting for basic motor skill. Furthermore, praxis performance was a strong predictor of the defining features of autism, measured using the Autism Diagnostic Observation Schedule, and this correlation remained significant after accounting for basic motor skill. Results indicate that dyspraxia in autism cannot be entirely accounted for by impairments in basic motor skills, suggesting the presence of additional contributory factors. Furthermore, praxis in children with autism is strongly correlated with the social, communicative, and behavioral impairments that define the disorder, suggesting that dyspraxia may be a core feature of autism or a marker of the neurological abnormalities underlying the disorder.