bluuebunny/crossref_metadata_2025 huggingface dataset:
Endogenous TNFα Lowers Maximum Peak Bone Mass and Inhibits Osteoblastic Smad Activation Through NF-κB
Authors: Li Yan , Li Aimin , Strait Karen , Zhang Hongying , Nanes Mark S , Weitzmann M Neale
Published: February 2007

Endogenous TNFα prevents the attainment of maximum achievable peak bone mass in vivo. In vitro, TNFα suppresses BMP-2– and TGFβ-mediated Smad activation through induction of NF-κB. Consistently, pharmacological suppression of NF-κB augments osteoblast differentiation and mineralization in vitro.

Introduction: Osteoporosis is a major health threat. Traditional therapeutic strategies have centered on anti-catabolic drugs that block bone resorption. Recently focus has shifted to anabolic agents that actively rebuild lost bone mass. Future strategies may involve elevating peak bone mass to delay osteoporosis development. Recent in vitro studies show that TNFα represses osteoblast differentiation and mineralization; however, the mechanisms are poorly understood and the impact of basal TNFα concentrations on the acquisition of peak bone mass in vivo is unknown.

Materials and Methods: We examined peak BMD, bone volume, and bone turnover makers in mice deficient in TNFα or its receptors. We further examined the effect of TNFα on Smad-induced signaling by TGFβ and BMP-2 in vitro using a Smad responsive reporter. The effect of TNFα-induced NF-κB signaling on Smad signaling and on in vitro osteoblast mineralization was examined using specific NF-κB inhibitors and activators, and effects of TNFα-induced NF-κB signaling on BMP-2–induced Runx2 mRNA were examined using RT-PCR.

Results: Mice null for TNFα or its p55 receptor had significantly increased peak bone mass, resulting exclusively from elevated bone formation. In vitro, TNFα potently suppressed Smad signaling induced by TGFβ and BMP-2, downregulated BMP-2–mediated Runx2 expression, and inhibited mineralization of osteoblasts. These effects were mimicked by overexpression of NF-κB and prevented by pharmacological NF-κB suppression.

Conclusions: Our data suggest that TNFα and NF-κB antagonists may represent novel anabolic agents for the maximization of peak basal bone mass and/or the amelioration of pathological bone loss.
Putative Susceptibility Locus on Chromosome 21q for Lumbar Disc Disease (LDD) in the Finnish Population
Authors: Virtanen Iita M , Noponen Noora , Barral Sandra , Karppinen Jaro , Li Hong , Vuoristo Mirka , Niinimäki Jaakko , Ott Jürg , Ala-Kokko Leena , Männikkö Minna
Published: February 2007

In the first linkage study on LDD, a common musculoskeletal disorder, a genome-wide scan was performed on 14 Finnish families. The analysis resulted in identification of a putative susceptibility locus for the disease on chromosome 21.

Introduction: Lumbar disc disease (LDD) is a common musculoskeletal disorder that affects ∼5% of the adult population. Several predisposing genetic and environmental risk factors have been identified for symptomatic LDD (i.e., symptomatic disc herniation and/or sciatic pain), but thus far, no common cause has been identified.

Materials and Methods: Medical history data were collected from 186 members of 14 Finnish families with LDD.

Results: A genome-wide scan resulted in 10 chromosomal regions providing LOD scores >1, and in fine mapping, maximum two-point LOD scores of 2.71, 2.36, and 2.04 were obtained for chromosomes 21 (D21S1257), 4 (D4S399), and 6 (D6S294), respectively. A second fine mapping confirmed the susceptibility of chromosome 21 with a two-point LOD score of 2.06 (D21S1922). In addition, a significant association between LDD and SNP rs716195 was observed (p < 0.001), and case-control analysis revealed pointwise significant differences with several markers. Interestingly, the locus for another spinal disorder, ossification of the posterior longitudinal ligament (OPLL), has been mapped to chromosome 21q, partially overlapping with our candidate region. Two candidate genes with aggrecanase activity, ADAMTS-1 and ADAMTS-5, were analyzed in the region, suggesting linkage, leading to the identification of 13 sequence variations. None of the variations were disease-causing, however, because they were observed equally in affected and healthy individuals.

Conclusions: We report here on the first putative susceptibility locus for LDD in the Finnish population. The candidate region on chromosome 21q spans >5.5 cM and contains several interesting genes for further analysis.
Identification of a New Metabolite of Astilbin, 3′-O-Methylastilbin, and Its Immunosuppressive Activity against Contact Dermatitis
Authors: Guo Jianming , Qian Feng , Li Jianxin , Xu Qiang , Chen Ting
Published: February 2007

Background: Astilbin is a flavonoid isolated from the rhizome of Smilax glabra. In a previous study, we revealed its unique immunosuppressive activity, a selective inhibition against activated T lymphocytes. This characteristic of astilbin is beneficial for the treatment of human immune diseases.

Methods: We incubated astilbin with rat liver microsomal/cytosolic fractions and isolated the metabolite of astilbin, which was fully characterized by mass spectrometry (MS) and nuclear magnetic resonance (NMR) spectroscopy. We administered astilbin orally via a gastric tube to rats at 0.22 mmol/kg and collected whole blood samples after 30 min and urine samples after 0 to 12 h. We applied HPLC and liquid chromatography/MS to measure the metabolite in the samples, and we assayed cytokine expression by reverse-transcription PCR.

Results: After incubation of astilbin with rat liver microsomal/cytosolic fractions, we detected a new metabolite of astilbin and isolated it from the culture solution. We characterized this metabolite by MS and NMR techniques as 3′-O-methylated astilbin. We detected the metabolite in both blood and urine samples after oral administration of astilbin, and the metabolite inhibited picryl chloride–induced ear swelling in mice and suppressed the expression of tumor necrosis factor-α and interferon-γ, similarly to astilbin.

Conclusion: This is the first identification of 3′-O-methylastilbin as a new flavonoid, as well as an active metabolite of astilbin in vivo, and is helpful for studying the kinetics of astilbin and its clinical applications.
Standardized Peptidome Profiling of Human Urine by Magnetic Bead Separation and Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry
Authors: Fiedler Georg Martin , Baumann Sven , Leichtle Alexander , Oltmann Anke , Kase Julia , Thiery Joachim , Ceglarek Uta
Published: February 2007

Background: Peptidome profiling of human urine is a promising tool to identify novel disease-associated biomarkers; however, a wide range of preanalytical variables influence the results of peptidome analysis. Our aim was to develop a standardized protocol for reproducible urine peptidome profiling by means of magnetic bead (MB) separation followed by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry (MS).

Methods: MBs with defined surface functionalities (hydrophobic interaction, cation exchange, and metal ion affinity) were used for peptide fractionation of urine. Mass accuracy and imprecision were calculated for 9 characteristic mass signals (Mr, 1000–10 000). Exogenous variables (instrument performance, urine sampling/storage conditions, freezing conditions, and freeze-thaw cycles) and endogenous variables (pH, urine salt and protein concentrations, and blood and bacteria interferences) were investigated with urine samples from 10 male and 10 female volunteers.

Results: We detected 427 different mass signals in the urine of healthy donors. Within- and between-day imprecision in relative signal intensities ranged from 1% to 14% and from 4% to 16%, respectively. Weak cation-exchange and metal ion affinity MB preparations required adjustment of the urinary pH to 7. Storage time, storage temperature, the number of freeze-thaw cycles, and bacterial and blood contamination significantly influenced urine peptide patterns. Individual urine peptide patterns differed significantly within and between days. This imprecision was diminished by normalization to a urinary protein content of 3.5 μg.

Conclusion: This reliable pretreatment protocol allows standardization of preanalytical modalities and facilitates reproducible peptidome profiling of human urine by means of MB separation in combination with MALDI-TOF MS.
Neocortical Inhibitory Terminals Innervate Dendritic Spines Targeted by Thalamocortical Afferents
Authors: Kubota Yoshiyuki , Hatada Sayuri , Kondo Satoru , Karube Fuyuki , Kawaguchi Yasuo
Published: February 2007

Fast inhibition in the cortex is gated primarily at GABAergic synapses formed by local interneurons onto postsynaptic targets. Although GABAergic inputs to the somata and axon initial segments of neocortical pyramidal neurons are associated with direct inhibition of action potential generation, the role of GABAergic inputs to distal dendritic segments, including spines, is less well characterized. Because a significant proportion of inhibitory input occurs on distal dendrites and spines, it will be important to determine whether these GABAergic synapses are formed selectively by certain classes of presynaptic cells onto specific postsynaptic elements. By electron microscopic observations of synapses formed by different subtypes of nonpyramidal cells, we found that a surprisingly large fraction (33.4 ± 9.3%) of terminals formed symmetrical synaptic junctions onto a subset of cortical spines that were mostly coinnervated by an asymmetrical terminal. Using VGLUT1 and VGLUT2 isoform of the glutamate vesicular transporter immunohistochemistry, we found that the double-innervated spines selectively received thalamocortical afferents expressing the VGLUT2 but almost never intracortical inputs expressing the VGLUT1. When comparing the volumes of differentially innervated spines and their synaptic junction areas, we found that spines innervated by VGLUT2-positive terminal were significantly larger than spines innervated by VGLUT1-positive terminal and that these spines had larger, and more often perforated, synapses than those of spines innervated by VGLUT1-positive afferent. These results demonstrate that inhibitory inputs to pyramidal cell spines may preferentially reduce thalamocortical rather than intracortical synaptic transmission and are therefore positioned to selectively gate extracortical information.
Stromal Cell-Derived Factor-1 Antagonizes Slit/Robo SignalingIn Vivo
Authors: Chalasani Sreekanth H. , Sabol Angela , Xu Hong , Gyda Michael A. , Rasband Kendall , Granato Michael , Chien Chi-Bin , Raper Jonathan A.
Published: February 2007

Retinal ganglion cell axons exit the eye, enter the optic stalk, cross the ventral midline at the optic chiasm, and terminate in the optic tectum of the zebrafish. While in the optic stalk, they grow immediately adjacent to cells expressing the powerful retinal axon repellent slit2. The chemokine stromal cell-derived factor-1 (SDF1) is expressed within the optic stalk and its receptor CXCR4 is expressed in retinal ganglion cells. SDF1 makes cultured retinal axons less responsive to slit2. Here, we show that reducing SDF1 signalingin vivorescues retinal axon pathfinding errors in zebrafish mutants that have a partial functional loss of the slit receptor robo2. In contrast, reducing SDF1 signaling in animals that completely lack the robo2 receptor does not rescue retinal guidance errors. These results demonstrate that endogenous levels of SDF1 antagonize the repellent effects of slit/robo signalingin vivoand that this antagonism is important during axonal pathfinding.
Visual Cortex Allows Prediction of Perceptual States during Ambiguous Structure-From-Motion
Authors: Brouwer Gijs Joost , van Ee Raymond
Published: February 2007

We investigated the role of retinotopic visual cortex and motion-sensitive areas in representing the content of visual awareness during ambiguous structure-from-motion (SFM), using functional magnetic resonance imaging (fMRI) and multivariate statistics (support vector machines). Our results indicate that prediction of perceptual states can be very accurate for data taken from dorsal visual areas V3A, V4D, V7, and MT+ and for parietal areas responsive to SFM, but to a lesser extent for other visual areas. Generalization of prediction was possible, because prediction accuracy was significantly better than chance for both an unambiguous stimulus and a different experimental design. Detailed analysis of eye movements revealed that strategic and even encouraged beneficial eye movements were not the cause of the prediction accuracy based on cortical activation. We conclude that during perceptual rivalry, neural correlates of visual awareness can be found in retinotopic visual cortex, MT+, and parietal cortex. We argue that the organization of specific motion-sensitive neurons creates detectable biases in the preferred direction selectivity of voxels, allowing prediction of perceptual states. During perceptual rivalry, retinotopic visual cortex, in particular higher-tier dorsal areas like V3A and V7, actively represents the content the visual awareness.
Signaling at A-Kinase Anchoring Proteins Organizes Anesthesia-Sensitive Memory inDrosophila
Authors: Schwaerzel Martin , Jaeckel Andrea , Mueller Uli
Published: February 2007

The ubiquitous cAMP–protein kinase A (PKA) signaling pathway exhibits complex temporal requirements during the time course of associative memory processing. This directly raises questions about the molecular mechanisms that provide signaling specificity to this pathway. Here, we useDrosophilaolfactory conditioning to show that divergent cAMP signaling is mediated by functionally distinct pools of PKA. One particular pool is organized via the PKA regulatory type II subunit at the level of A-kinase anchoring proteins (AKAPs), a family of scaffolding proteins that provides focal points of spatiotemporal signal integration. This AKAP-bound pool of PKA is acting within neurons of the mushroom bodies to support a late phase of aversive memory. The requirement for AKAP-bound PKA signaling is limited to aversive memory, but dispensable during appetitive memory. This finding suggests the existence of additional mechanisms to support divergence within the cAMP–PKA signaling pathway during memory processing. Together, our results show that subcellular organization of signaling components plays a key role in memory processing.
Impaired Axonal Regeneration by Isolectin B4-Binding Dorsal Root Ganglion NeuronsIn Vitro
Authors: Leclere Pascal G. , Norman Emma , Groutsi Filitsa , Coffin Robert , Mayer Ulrike , Pizzey John , Tonge David
Published: February 2007

The subpopulation of dorsal root ganglion (DRG) neurons recognized byGriffonia simplicifoliaisolectin B4 (IB4) differ from other neurons by expressing receptors for glial cell line-derived neurotrophic factor (GDNF) rather than neurotrophins. Additionally, IB4-labeled neurons do not express the laminin receptor, α7-integrin (Gardiner et al., 2005), necessary for optimal axonal regeneration in the peripheral nervous system. In cultures of dissociated DRG neurons of adult mice on laminin, robust spontaneous neurite outgrowth from IB4-negative neurons occurs and is strongly enhanced by previous axotomy. In contrast, IB4-labeled neurons show little neurite outgrowth and do not express GAP 43, even after axotomy or culture with GDNF. Moreover, growth of their axons through collagen gels is impaired compared with other DRG neurons. To determine whether the sparse neurite outgrowth of IB4-labeled neurons is attributable to lack of integrin expression, DRG cultures were infected with a herpes simplex 1 vector encoding α7-integrin, but its forced expression failed to promote neurite outgrowth in either IB4-labeled or other DRG neurons or in cultured adult retinal ganglion cells. Forced coexpression of both α7-integrin and GAP 43 also failed to promote neurite outgrowth in IB4-labeled neurons. In addition, cultured sciatic nerve segments were found to release much lower levels of GDNF, demonstrated by ELISA, than nerve growth factor. These findings together with their impaired intrinsic axonal regeneration capacity may contribute to the known vulnerability of the IB4-labeled population of DRG neurons to peripheral nerve injury.
Longitudinal Relationship Between Television Viewing and Leisure-Time Physical Activity During Adolescence
Authors: Taveras Elsie M. , Field Alison E. , Berkey Catherine S. , Rifas-Shiman Sheryl L. , Frazier A. Lindsay , Colditz Graham A. , Gillman Matthew W.
Published: February 2007

OBJECTIVE. The goal was to examine the longitudinal associations of changes in television viewing and other sources of sedentary behavior with changes in leisure-time moderate/vigorous physical activity in adolescence.

METHODS. We studied a cohort of 6369 girls and 4487 boys who were 10 to 15 years of age in 1997. During each of 4 years of follow-up assessments, participants self-reported their weekly hours of television viewing. By using a seasonal questionnaire, we also obtained detailed information on physical activities over the previous year, from which we calculated total leisure-time moderate/vigorous physical activity. We performed linear regression analyses to assess the longitudinal associations between 1-year changes in television viewing and 1-year changes in leisure-time moderate/vigorous physical activity during the same year, using data from 1997 through 2001.

RESULTS. One-year changes (mean ± SD) were −0.13 ± 7.2 hours/week for leisure-time moderate/vigorous physical activity, −0.55 ± 7.0 hours/week for television viewing, and −1.02 ± 11.0 hours/week for total sedentary behaviors. In longitudinal models adjusted for age, age2, gender, race/ethnicity, Tanner stage, menarche (in girls), baseline physical activity, and baseline television viewing, we found no substantive relationship between year-to-year changes in television viewing and changes in leisure-time moderate/vigorous physical activity (0.03 hours/week, for each 1-hour/week change in television viewing). There were no material associations in age or gender subgroups.

CONCLUSIONS. In this longitudinal study, changes in television viewing were not associated with changes in leisure-time moderate/vigorous physical activity. Our findings suggest that television viewing and leisure-time physical activity are separate constructs, not functional opposites.
Nonphysician Clinicians in the Neonatal Intensive Care Unit: Meeting the Needs of Our Smallest Patients
Authors: Reynolds Eric W. , Bricker J. Timothy
Published: February 2007

Regional variations in the distribution of neonatal physicians and dependence on housestaff with restricted work hours have created workforce shortages in many NICUs. Although neonatal nurse practitioners assist in the delivery of high-quality care, availability of these providers may be inadequate in certain regions. Physician assistants represent a historically underutilized resource to resolve neonatology's workforce issues. We have developed a postgraduate training program for physician assistants in neonatology that we hope will improve local and regional workforce shortages. In this article we discuss the history of neonatal nurse practitioners and physician assistants in newborn care and outline the program that we developed. We further discuss some of the barriers we had to overcome in developing this program. Our program can serve as a model for other neonatology programs to adequately prepare physician assistants for a career in the NICU.
Factors Associated With Treatment for Hypotension in Extremely Low Gestational Age Newborns During the First Postnatal Week
Authors: Laughon Matthew , Bose Carl , Allred Elizabeth , O'Shea T. Michael , Marter Linda J. Van , Bednarek Francis , Leviton Alan ,   for the ELGAN Study Investigators
Published: February 2007

OBJECTIVE. The goals were to identify the blood pressures of extremely low gestational age newborns that prompt intervention, to identify other infant characteristics associated with receipt of therapies intended to increase blood pressure, and to assess the interinstitutional variability in the use of these therapies.

METHODS. The cohort included 1507 extremely low gestational age newborns born at 23 weeks to 27 weeks of gestation, at 14 institutions, between March 2002 and August 2004; 1387 survived the first postnatal week. Blood pressures were measured as clinically indicated. Interventions were grouped as any treatment (ie, vasopressor and/or fluid boluses of >10 mL/kg) and vasopressor treatment, and logistic regression analyses were performed.

RESULTS. At each gestational age, the lowest mean arterial pressures in treated and untreated infants tended to increase with advancing postnatal age. Infants who received any therapy tended to have lower mean arterial pressures than infants who did not, but uniform thresholds for treatment were not apparent. The proportion of infants receiving any treatment decreased with increasing gestational age from 93% at 23 weeks to 73% at 27 weeks. Treatment nearly always began during the first 24 hours of life. Lower gestational age, lower birth weight, male gender, and higher Score for Neonatal Acute Physiology–II values were associated with any treatment and vasopressor treatment. Institutions varied greatly in their tendency to offer any treatment and vasopressor treatment. Neither the lowest mean arterial pressure on the day of treatment nor other characteristics of the infants accounted for center differences in treatment.

CONCLUSIONS. Blood pressure in extremely premature infants not treated for hypotension increased directly with both increasing gestational age and postnatal age. The decision to provide treatment was associated more strongly with the center where care was provided than with infant attributes.
Postnatal Dexamethasone Therapy and Cerebral Tissue Volumes in Extremely Low Birth Weight Infants
Authors: Parikh Nehal A. , Lasky Robert E. , Kennedy Kathleen A. , Moya Fernando R. , Hochhauser Leo , Romo Seferino , Tyson Jon E.
Published: February 2007

OBJECTIVE. Our goal was to relate postnatal dexamethasone therapy in extremely low birth weight infants (birth weight of ≤1000 g) to their total and regional brain volumes, as measured by volumetric MRI performed at term-equivalent age.

METHODS. Among 53 extremely low birth weight infants discharged between June 1 and December 31, 2003, 41 had high-quality MRI studies; 30 of those infants had not received postnatal steroid treatment and 11 had received dexamethasone, all after postnatal age of 28 days, for a mean duration of 6.8 days and a mean cumulative dose of 2.8 mg/kg. Anatomic brain MRI scans obtained at 39.5 weeks (mean) postmenstrual age were segmented by using semiautomated and manual, pretested, scoring algorithms to generate three-dimensional cerebral component volumes. Volumes were adjusted according to postmenstrual age at MRI.

RESULTS. After controlling for postmenstrual age at MRI, we observed a 10.2% smaller total cerebral tissue volume in the dexamethasone-treated group, compared with the untreated group. Cortical tissue volume was 8.7% smaller in the treated infants, compared with untreated infants. Regional volume analysis revealed a 20.6% smaller cerebellum and a 19.9% reduction in subcortical gray matter in the dexamethasone-treated infants, compared with untreated infants. In a series of regression analyses, the reductions in total cerebral tissue, subcortical gray matter, and cerebellar volumes associated with dexamethasone administration remained significant after controlling not only for postmenstrual age but also for bronchopulmonary dysplasia and birth weight.

CONCLUSIONS. We identified smaller total and regional cerebral tissue volumes in extremely low birth weight infants treated with relatively conservative regimens of dexamethasone. These volume deficits may be the structural antecedents of neuromotor and cognitive abnormalities reported after postnatal dexamethasone treatment.
Impact of Prenatal Cocaine Exposure on Child Behavior Problems Through School Age
Authors: Bada Henrietta S. , Das Abhik , Bauer Charles R. , Shankaran Seetha , Lester Barry , LaGasse Linda , Hammond Jane , Wright Linda L. , Higgins Rosemary
Published: February 2007

OBJECTIVE. We examined the trajectory of childhood behavior problems after prenatal cocaine exposure.

METHODS. The Maternal Lifestyle Study, a longitudinal cohort study, enrolled children between 1993 and 1995 at 4 centers. Prenatal cocaine exposure was determined from mothers who admitted use and/or meconium results. Exposed children were matched with a group of nonexposed children within site and by gestational age, gender, race, and ethnicity. The study began at the 1-month corrected age with a total of 1388 children enrolled. A total of 1056 were assessed for internalizing, externalizing, and total behavior problems at ages 3, 5, and 7 years using the Child Behavior Checklist. Longitudinal hierarchical linear models were used to determine the effect of prenatal cocaine exposure on behavior problem trajectories while controlling for other prenatal exposures; time-varying covariates, including ongoing caregiver use of legal and illegal substances; demographic factors; family violence; and caregiver psychological distress.

RESULTS. High prenatal cocaine exposure was associated with the trajectory of internalizing, externalizing, and total behavior problems; these effects were independent of and less than the significant combined effect of prenatal and postnatal tobacco and alcohol exposures. Caregiver depression and family violence had independent negative influence on all behavior outcomes.

CONCLUSIONS. Prenatal cocaine exposure has a negative impact on the trajectories of childhood behavior outcomes. When they co-occur with prenatal cocaine exposure, prenatal and postnatal tobacco and alcohol exposures have added negative effects on behavior outcomes.
Risk and Promotive Factors in Families, Schools, and Communities: A Contextual Model of Positive Youth Development in Adolescence
Authors: Youngblade Lise M. , Theokas Christina , Schulenberg John , Curry Laura , Huang I-Chan , Novak Maureen
Published: February 2007

OBJECTIVE. Emerging evidence about optimal youth development highlights the importance of both reducing negative behavior and promoting positive behavior. In our study we tested a contextual model derived from positive youth-development theory by examining the association of family, school, and community risk and promotive factors, with several outcome indices of both positive and negative adolescent development.

METHODS. A sample of 42305 adolescents aged 11 to 17 (51% girls) was drawn from the 2003 National Survey of Children's Health. Survey item composites were formed representing promotive and risk factors in the family (eg, closeness, aggression) and school and community (eg, community connectedness, school violence). Outcome composites reflected positive (social competence, health-promoting behavior, self-esteem) and negative (externalizing, internalizing, academic problems) developmental outcomes. Ordinary least squares regression was used to test the overall model.

RESULTS. Between 0.10 and 0.50 of the variance in each outcome was explained by the contextual model. Multiple positive family characteristics were related to adolescent social competence and self-esteem, as well as lowered levels of internalizing and externalizing behavior and academic problems. Family communication, rules about television, and parents' own healthy behavior were related to adolescent health-promoting behavior. School and community safety were associated with increased social competence and decreased externalizing behavior. School violence was related to adolescent internalizing and externalizing behavior, as well as academic problems and lower self-esteem.

CONCLUSIONS. Our results support the proposition that healthy adolescent development has roots in multiple contexts. Youth who were involved in contexts that provided positive resources from important others (ie, parents, schools, and communities) not only were less likely to exhibit negative outcomes, but also were more likely to show evidence of positive development. These findings provide important implications for intervention and prevention efforts and, more generally, for the promotion of positive, competent, and healthy youth development.
National Estimates and Factors Associated With Medication Treatment for Childhood Attention-Deficit/Hyperactivity Disorder
Authors: Visser Susanna N. , Lesesne Catherine A. , Perou Ruth
Published: February 2007

OBJECTIVE. In this study we identified child and family-level characteristics that were associated with medication treatment for attention-deficit/hyperactivity disorder using nationally representative survey data.

METHODS. National Survey of Children's Health data from 79264 youth 4 to 17 years of age were used. Data were weighted to adjust for the complex survey design of the National Survey of Children's Health. Gender-specific logistic regression models were generated to identify child and family-level characteristics that were collectively associated with current medication status among youth with a reported diagnosis of attention-deficit/hyperactivity disorder.

RESULTS. Nationally, 7.8% of youth aged 4 to 17 years had a reported attention-deficit/hyperactivity disorder diagnosis, and 4.3% had both a disorder diagnosis and were currently taking medication for the disorder. Current medication treatment among youth with attention-deficit/hyperactivity disorder was associated with white race, younger age, English spoken in the home, health care coverage, a health care contact within the last year, and reported psychological difficulties. Gender-specific logistic regression models revealed that, together, younger age, higher income, health care coverage, having psychological difficulties, and a health care contact in the past year were associated with medication use among boys with attention-deficit/hyperactivity disorder. Among girls with the disorder, younger age, psychological difficulties, fair-to-poor paternal mental health status, and a health care contact within the last year were collectively associated with current medication use.

CONCLUSIONS. Regardless of gender, younger age, the presence of psychological difficulties, and a recent health care contact were significantly associated with medication treatment for attention-deficit/hyperactivity disorder. However, additional health care access and income variables among boys and paternal mental health status among girls represented gender-specific factors that were also associated with medication treatment for the disorder. Future studies should characterize how and when the burden associated with attention-deficit/hyperactivity disorder leads to treatment, support, or services for this prevalent and impairing neurobehavioral disorder.
The Relationship Between Autism and Parenting Stress
Authors: Schieve Laura A. , Blumberg Stephen J. , Rice Catherine , Visser Susanna N. , Boyle Coleen
Published: February 2007

OBJECTIVE. We assessed associations between parenting a child with autism and stress indicators.

METHODS. In the 2003 National Survey of Children’s Health, parents or other knowledgeable adult respondents for children aged 4 to 17 years reported their recent feelings about their life sacrifices to care for their child, difficulty caring for their child, frustration with their child’s actions, and anger toward their child. Responses were compiled in the Aggravation in Parenting Scale. Parents of children reported to have autism (N = 459) were compared with parents of: (1) children with special health care needs including emotional, developmental, or behavioral problems other than autism that necessitated treatment (children with other developmental problems [N = 4545]); (2) children with special health care needs without developmental problems (N = 11475); and (3) children without special health care needs (N = 61826). Weighted estimates are presented.

RESULTS. Parents of children with autism were more likely to score in the high aggravation range (55%) than parents of children with developmental problems other than autism (44%), parents of children with special health care needs without developmental problems (12%), and parents of children without special health care needs (11%). However, within the autism group, the proportion of parents with high aggravation was 66% for those whose child recently needed special services and 28% for those whose child did not. The parents of children with autism and recent special service needs were substantially more likely to have high aggravation than parents of children with recent special service needs in each of the 3 comparison groups. Conversely, parents of children with autism but without recent special service needs were not more likely to have high aggravation than parents of children with other developmental problems.

CONCLUSIONS. Parenting a child with autism with recent special service needs seems to be associated with unique stresses.
Both Extremes of Arterial Carbon Dioxide Pressure and the Magnitude of Fluctuations in Arterial Carbon Dioxide Pressure Are Associated With Severe Intraventricular Hemorrhage in Preterm Infants
Authors: Fabres Jorge , Carlo Waldemar A. , Phillips Vivien , Howard George , Ambalavanan Namasivayam
Published: February 2007

OBJECTIVE. The goal was to test the hypothesis that extremes of Paco2 during the first 4 days after birth are associated with severe intraventricular hemorrhage (grades 3 and 4).

METHODS. A single-center retrospective review of clinical and blood gas data in the first 4 postnatal days for 849 infants with birth weights of 401 to 1250 g was performed. The univariate and multivariate relationships of severe intraventricular hemorrhage with maximal and minimal Paco2, Paco2 averaged over time (time-weighted Paco2), and measures of Paco2 fluctuation (SD of Paco2 and difference in Paco2 [maximum minus minimum]) were assessed.

RESULTS. Birth weight (mean ± SD) was 848 ± 212 g, and the median gestational age was 26 weeks. Infants with severe intraventricular hemorrhage had higher maximal Paco2 (median: 72 vs 59 mm Hg) and time-weighted Paco2 (mean: 49 vs 47 mm Hg) values but lower minimal Paco2 values (32 vs 37 mm Hg). High Paco2, low Paco2, SD of Paco2, and difference in Paco2 predicted severe intraventricular hemorrhage, but time-weighted average Paco2 was not as predictive.

CONCLUSIONS. Both extremes and fluctuations of Paco2 are associated with severe intraventricular hemorrhage. It may be prudent to avoid extreme hypocapnia and hypercapnia during the period of risk for intraventricular hemorrhage.
Effects of annealing and specimen geometry on dynamic compression of a Zr-based bulk metallic glass
Authors: Sunny George , Lewandowski John , Prakash Vikas
Published: February 2007

High strain-rate compression experiments were performed with a split-Hopkinson pressure bar (SHPB) at 500–4000/s on cylindrical samples of a Zr-based bulk metallic glass (LM-1) in both the fully amorphous and annealed conditions. The effects of changes to the specimen geometry (i.e., L/D ratio) and the material heat treatment [i.e., annealing versus amorphous (as-received)], on the peak stress, strain-to-failure, and failure behavior were determined with the aid of an in situ video obtained by using a high-speed digital camera in conjunction with the split-Hopkinson pressure bar (SHPB). Examination of the in situ video recordings and light optical microscopy showed that the failed samples revealed preferential failure initiating at the sample ends due to stress concentration at the sample-insert interface. A new insert design was developed using transient, elastic-plastic finite-element simulations to reduce the effects of these stress concentrations. SHPB testing, combined with in situ video, subsequently revealed that this new experimental configuration promoted failure within the gage length and away from the sample ends in the samples tested. Significant effects of specimen geometry, insert design, and annealing on the apparent values of the peak stress, strain-to-failure, and fracture behavior were exhibited.
Fatigue behavior of an Fe48Cr15Mo14Er2C15B6 amorphous steel
Authors: Qiao D.C. , Wang G.Y. , Liaw P.K. , Ponnambalam V. , Poon S.J. , Shiflet G.J.
Published: February 2007

Four-point-bend fatigue experiments were conducted on the Fe48Cr15Mo14Er2C15B6 bulk metallic glass (BMG), amorphous steel, under load control, employing an electrohydraulic machine, at a frequency of 10 Hz (using a sinusoidal waveform) with an R ratio of 0.1, where R = σmin./σmax. (σmin. and σmax. are the applied minimum and maximum stresses, respectively). The test environment was laboratory air. Fe48Cr15Mo14Er2C15B6 exhibited a high fatigue-endurance limit (682 MPa), which is found to be greater than those of the Zr-based BMG, Al-alloy, and high-nitrogen steel. However, the stress versus number of fatigue cycles curve of Fe48Cr15Mo14Er2C15B6 has a significantly brittle fracture mode. Some fatigue cracks initiated from the inclusions or porosities, and the fatigue-crack propagation region was large. However, other cracks initiated from the outer tensile surface of the specimen, and the fatigue-crack propagation region was very small. The mechanisms of fatigue-crack initiation are suggested.
Mechanical properties of bulk metallic glasses and composites
Authors: Eckert J. , Das J. , Pauly S. , Duhamel C.
Published: February 2007

The development of bulk metallic glasses and composites for improving the mechanical properties has occurred with the discovery of many ductile metallic glasses and glass matrix composites with second phase dispersions with different length scales. This article reviews the processing, microstructure development, and resulting mechanical properties of Zr-, Ti-, Cu-, Mg-, Fe-, and Ni-based glassy alloys and also considers the superiority of composite materials containing different phases for enhancing the strength, ductility, and toughness, even leading to a “work-hardening-like” behavior. The morphology, shape, and length scale of the second phase dispersions are crucial for the delocalization of shear bands. The article concludes with some comments regarding future directions of the investigations of spatially inhomogeneous metallic glasses.
Experimental observations of deformation behavior of bulk metallic glasses during wedge-like cylindrical indentation
Authors: Antoniou Antonia , Bastawros Ashraf , Biner Bulent
Published: February 2007

This article reports on the in situ observations of deformation behavior of a metallic glass under a wedge-like cylindrical indenter. The experimental observations for various indenter radii provide information on both macroscopic and microscopic details of the deformation. The deformation zones developed under indenters with different radii that were found to be self-similar and in agreement with the predictions of continuum finite-element simulation with pressure-dependent yielding. There are two types of shear bands being identified beneath the indenter. A set of primary bands is identified as evolving with the process zone front and presents an included angle of 78–80°. The other set of bands evolves at a later stage of loading within the originally formed ones but with a consistently higher included angle of around 87°. Despite the richness of the shear-band details, the macroscopic trends, the force-indentation depth response, and the extent of deformation zones are well captured for this constrained deformation mode by the continuum models that address the onset of yielding only.
Observation of shear bands formation on tungsten fiber-reinforced Zr-based bulk metallic glass matrix composite
Authors: Qiu K.Q. , Suo Z.Y. , Ren Y.L. , Yu B.
Published: February 2007

A Zr-based metallic glass matrix composite with 40 vol% tungsten fiber reinforcement was loaded step by step. After each loading step, shear-band patterns and fracture surface were observed. The results show that shear bands, cracks, and voids form during plastic deformation, and they exhibit different feature characteristics at various loading stages. As reinforcement, the tungsten fiber substantially affects the deformation and fracture processes of the composite.
Local temperature rises during mechanical testing of metallic glasses
Authors: Zhang Y. , Stelmashenko N.A. , Barber Z.H. , Wang W.H. , Lewandowski J.J. , Greer A.L.
Published: February 2007

Under ambient conditions, plastic flow in metallic glasses is sharply localized into shear bands. The heat content of, and consequent temperature rise at, shear bands in three bulk metallic glasses are compared using a recently reported fusible coating method. The minimum shear offsets necessary to detect local heating are determined. It is shown that the dependence of heat content on offset is consistent with frictional heating in the band. The effective stress on the band undergoing shear is 50–70% of the macroscopic shear stress, a ratio compared with simulations of shear-band initiation and operation. It is also noted that frictional heating can occur not only at shear bands, but also at mixed-mode cracks.
Painful bladder syndrome and interstitial cystitis
Authors: Jha Swati , Parsons Matthew , Toozs‐Hobson Philip
Published: February 2007

Key content

Painful bladder syndrome is a chronic disabling condition that mainly affects women.

The aetiology is uncertain, but is almost certainly multi‐factorial and presents as a triad of pain, urinary urgency and frequency.

The most common diagnosis made is interstitial cystitis. Diagnosis is based on history and examination and supplemented by clinical investigation.

Learning objectives

To be able to identify the clinical features of interstitial cystitis and arrange appropriate diagnostic tests.

To know how to manage interstitial cystitis using non‐pharmacological, dietary and behavioural treatment, as well as pharmacological and surgical therapy.

Ethical issues

How much information should women be given about possible adverse effects?

Please cite this article as: Jha S, Parsons M, Toozs‐Hobson P. Painful bladder syndrome and interstitial cystitis. The Obstetrician & Gynaecologist 2007;9:34–41.
Stocking of Endangered Razorback Suckers in the Lower Colorado River Basin over Three Decades: 1974–2004
Authors: Schooley Jason D. , Marsh Paul C.
Published: February 2007

The razorback sucker Xyrauchen texanus was historically widespread and abundant throughout the larger streams of the Colorado River basin, ranging from Sonora, Mexico, to Wyoming. The species was federally listed as endangered in 1991 because it has been extirpated from most of its range. Its decline is attributed to habitat loss and predation by nonnative fishes. Thirty years of federal and state effort have resulted in stocking millions of razorback suckers to the lower Colorado River basin, but only a few individuals have been recaptured because the young are rapidly consumed by introduced predators, resulting in insufficient recruitment to adulthood. Elderly, wild adults of this long-lived species are vanishing, and lower Colorado River basin recovery efforts now focus on replacement of these fish with repatriated (or reintroduced) adults. Stocking success and subsequent survival increases with size at release. When estimates of size-based, first-year survival rates were applied to individual batches of repatriated fish, we observed less than 1% overall first-year survival, and most fish stocked to date are thought to have been consumed soon after release. Overall, stocking has been unsuccessful, long-term survival is unknown, and no new populations have been established.
Population Characteristics of Shovelnose Sturgeon in the Upper Wabash River, Indiana
Authors: Kennedy Anthony J. , Daugherty Daniel J. , Sutton Trent M. , Fisher Brant E.
Published: February 2007

Shovelnose sturgeon Scaphirhynchus platorynchus support a commercial fishery throughout much of the Mississippi and Missouri River drainages. There is concern that harvest closures for Eurasian sturgeons (Acipenseridae) may result in increased exploitation of shovelnose sturgeon to meet global demands for caviar. Population attributes of shovelnose sturgeon were examined in the upper Wabash River, Indiana, from April 2003 through November 2004 between Wabash and Terre Haute. Fish (N = 4,849) were captured by direct current electrofishing, experimental gill nets, and benthic trawls. Electrofishing catch per unit effort varied on a temporal basis, being highest for both reaches from March through May. The fork length of captured fish ranged from 273 to 858 mm, but few fish less than 550 mm were captured. Median fork length and wet weight were 683 mm and 1,208 g, respectively (ranges = 273–858 mm and 52–3,381 g). Shovelnose sturgeon ranged from ages 2 to 30, with 95% of the fish between ages 9 and 20. Total annual mortality for fish between ages 13 and 18 was 20%. Empirical growth rates derived from recaptured fish were slow; 74% of the fish exhibited negative or no growth. The population characteristics of shovelnose sturgeon in the upper Wabash River were within the ranges reported for other river systems, but fish attained a larger body size, reached older age-classes, and experienced lower mortality rates than did some other populations. The results from this study will allow for the detection of shifts in abundance, size and age structure, and gender ratio in response to harvest or natural perturbations and promote the development of appropriate management actions to ensure the sustainability of this species and its fishery.
Survival and Tag Retention of Pacific Lamprey Larvae and Macrophthalmia Marked with Coded Wire Tags
Authors: Meeuwig Michael H. , Puls Amy L. , Bayer Jennifer M.
Published: February 2007

We examined the survival, tag retention, and growth of Pacific lamprey Lampetra tridentata larvae and macrophthalmia marked with standard-length decimal coded wire tags and exposed to two levels of handling stress. The survival of marked individuals did not differ from that of unmarked individuals at either life stage for the duration of the experiment (56 d). Tag retention was 100% for all treatment combinations except larvae that were handled frequently (93 ± 3%). The majority of tag loss occurred within 28 d of marking, and no tag loss was observed between 42 and 56 d after marking. The individuals that lost tags were among the smallest marked, and a logistic regression model indicated a relationship between larva length and the probability of tag retention. Size of larvae (length and mass) and macrophthalmia (mass) decreased over the duration of the experiment; however, changes in size were systematic among treatment combinations, indicating that factors other than tagging or handling affected growth. These data indicate that coded wire tags may be useful for field-based studies of Pacific lamprey larvae and macrophthalmia.