bluuebunny/crossref_metadata_2025_split huggingface dataset:
The impact of imprecisely measured covariates on estimating gene-environment interactions
Authors: Greenwood Darren C , Gilthorpe Mark S , Cade Janet E 
Published: May 2006

Abstract

Background
The effects of measurement error in epidemiological exposures and confounders on estimated effects of exposure are well described, but the effects on estimates for gene-environment interactions has received rather less attention. In particular, the effects of confounder measurement error on gene-environment interactions are unknown.

Methods
We investigate these effects using simulated data and illustrate our results with a practical example in nutrition epidemiology.

Results
We show that the interaction regression coefficient is unchanged by confounder measurement error under certain conditions, but biased by exposure measurement error. We also confirm that confounder measurement error can lead to estimated effects of exposure biased either towards or away from the null, depending on the correlation structure, with associated effects on type II errors.

Conclusion
Whilst measurement error in confounders does not lead to bias in interaction coefficients, it may still lead to bias in the estimated effects of exposure. There may still be cost implications for epidemiological studies that need to calibrate all error-prone covariates against a valid reference, in addition to the exposure, to reduce the effects of confounder measurement error.
Memory performance in multiple sclerosis patients correlates with central brain atrophy
Authors: Hildebrandt H , Hahn H K , Kraus J A , Schulte-Herbrüggen A , Schwarze B , Schwendemann G 
Published: May 2006

Objective To assess whole brain and central brain atrophy as well as their differential relation to memory, cognitive performance, fatigue, depression and quality of life in patients with relapsingremitting multiple sclerosis (RRMS). Methods A 3D flow compensated gradient recalled T1-weighted MRI was acquired in 45 RRMS patients. An automated analysis tool was used to calculate brain parenchymal fraction (BPF) and ventricular brain fraction (VF). All patients were assessed with neuropsychological tests focusing on memory and self-rating scales for depression, fatigue and quality of life. Age corrected partial correlations between brain atrophy, motor performance, psychological scales and test scores were calculated. Results BPF correlated moderately (0.35≤r<0.5) with duration of symptoms and disease, the Expanded Disability Status Scale (EDSS), the upper extremity motor performance, and with mental aspects of quality of life. VF correlated moderately with EDSS, upper and lower extremity motor performance and memory functions. Neither BPF nor VF correlated with fatigue and depression. Results of several cognitive tests correlated moderately with depression and fatigue, the Paced Auditory Serial Addition Test (PASAT) showing the largest correlation. Conclusions Memory performance shows a correlation with relative ventricular size in RRMS patients, indicating the strategic location of the ventricle system along the structures of the limbic system and its vulnerability in MS. The PASAT and several other cognitive tests show moderate correlations with depression and fatigue, arguing for an inter relation between the cognitive functioning and the emotional state of patients. However, this relation is independent of measurable brain atrophy.
Reciprocal expression of gill Na+/K+-ATPaseα-subunit isoforms α1a and α1b during seawater acclimation of three salmonid fishes that vary in their salinity tolerance
Authors: Bystriansky J. S. , Richards J. G. , Schulte P. M. , Ballantyne J. S. 
Published: May 2006

SUMMARYThe upregulation of gill Na+/K+-ATPase activity is considered critical for the successful acclimation of salmonid fishes to seawater. The present study examines the mRNA expression of two recently discovered α-subunit isoforms of Na+/K+-ATPase(α1a and α1b) in gill during the seawater acclimation of three species of anadromous salmonids, which vary in their salinity tolerance. Levels of these Na+/K+-ATPase isoforms were compared with Na+/K+-ATPase activity and protein abundance and related to the seawater tolerance of each species. Atlantic salmon (Salmo salar) quickly regulated plasma Na+, Cl– and osmolality levels within 10 days of seawater exposure, whereas rainbow trout(Oncorhynchus mykiss) and Arctic char (Salvelinus alpinus)struggled to ionoregulate, and experienced greater perturbations in plasma ion levels for a longer period of time. In all three species, mRNA levels for theα1a isoform quickly decreased following seawater exposure whereasα1b levels increased significantly. All three species displayed similar increases in gill Na+/K+-ATPase activity during seawater acclimation, with levels rising after 10 and 30 days. Freshwater Atlantic salmon gill Na+/K+-ATPase activity and protein content was threefold higher than those of Arctic char and rainbow trout, which may explain their superior seawater tolerance. The role of the α1b isoform may be of particular importance during seawater acclimation of salmonid fishes. The reciprocal expression of Na+/K+-ATPase isoforms α1a and α1b during seawater acclimation suggests they may have different roles in the gills of freshwater and marine fishes; ion uptake in freshwater fish and ion secretion in marine fishes.
Removal of the chorion before hatching results in increased movement and accelerated growth in rainbow trout (Oncorhynchus mykiss)embryos
Authors: Ninness Marcie M. , Stevens E. Don , Wright Patricia A. 
Published: May 2006

SUMMARYWe investigated the effects of the chorion on movement and growth in rainbow trout (Oncorhynchus mykiss) embryos. To test if the chorion restricts movement and growth before hatching, we manually removed the chorion 3–6 days before the natural time of hatching (dechorionated) and compared movement, growth and oxygen consumption in dechorionated embryos and in embryos whose chorions remained intact until the time of hatching(chorionated). Dechorionated embryos exhibited 36 times more movement before hatching compared with intact embryos. By 10 h post-hatch there was no difference in the number of movements between the two groups. At the time of hatching [30 days post-fertilization (d.p.f.)], dechorionated embryos had a significantly greater embryonic body dry mass compared with chorionated embryos, which persisted up to 45 d.p.f. At first feeding (50 d.p.f.) there was no significant difference in embryonic body dry mass between the two groups. Dechorionated embryos had a significantly greater embryonic body protein content after hatching (32, 33 d.p.f.) compared with chorionated embryos. Despite the differences in movement and growth, there were no significant differences in oxygen consumption between chorionated and dechorionated embryos. Furthermore, there was no correlation between the number of movements and oxygen consumption in rainbow trout embryos(chorionated, dechorionated, and hatched). Taken together, the data indicate that rainbow trout embryos have the capacity to be relatively active before hatching, but that the chorion restricts or inhibits movement. Moreover,precocious activity in pre-hatch embryos is correlated with accelerated growth and higher protein content, suggesting that the exercise training effect observed in adult salmonids is also present in early developmental stages.
Common and specific inhibitory motor neurons innervate the intersegmental muscles in the locust thorax
Authors: Bräunig Peter , Schmäh Michael , Wolf Harald 
Published: May 2006

SUMMARYThe inhibitory innervation of the intersegmental (body wall) muscles between the first and the second thoracic segment of the migratory locust, Locusta migratoria, was investigated using neuroanatomical,immunocytochemical and electrophysiological techniques. Three neurons located in the prothoracic ganglion show GABA-like immunoreactivity and project into the intersegmental nerve. Two are common inhibitors. One of those innervates the oblique intersegmental muscle M59 and two dorsal longitudinal muscles (M81 and M82). The second common inhibitor also innervates M59 and the ventral longitudinal muscle M60. The third neuron innervates M60 exclusively and, for that reason, has to be regarded as the first specific inhibitor ever observed in insect neuromuscular assemblies. According to their innervation pattern, we term these neurons CI59/60, CI59/81/82, and SI60. CI59/81/82 and CI59/60 appear to be segmentally homologous to CIa and CIb neurons,respectively, in the other body segments.
Synthesis and Characterization of a New μ-Alkoxodiiron(III) Complex with NO5 Donor Set Environments
Authors: Kawata Satoshi , Nakamura Masaaki , Yamashita Yoichi , Asai Kichizo , Kikuchi Koichi , Ikemoto Isao , Katada Motomi , Sano Hirotoshi 
Published: May 2006

Abstract
A new dinuclear iron(III) complex, [Fe2(hpta)(Obz)(H2O)2], where H5hpta is 2-hydroxy-1,3-propanediamine-N,N,N′,N′-tetraacetic acid and HObz is benzoic acid, was prepared and characterized. X-Ray structure analysis revealed that the complex has mono(μ-carboxylato)(μ-alkoxo) diiron(III) core and each iron atom has an NO5 donor set in a distorted octahedron.
An Efficient Synthesis of Cerbinal, a 10 π Aromatic Iridoid
Authors: Ge Yuting , Isoe Sachihiko 
Published: May 2006

Abstract
Cerbinal, an unusual iridoid with 10 π-System, was synthesized from (+)-genipin in 6 steps via dehydration of the hemiacetal and subsequent dehydrogenation with DDQ.
Preparation of Chloroacetaldehyde Cyclic Trimer and Its Depolymerization
Authors: Wakasugi Takashi , Tonouchi Naka , Miyakawa Tadashi , Ishizuka Makoto , Yamauchi Takashi , Itsuno Shinichi , Ito Koichi 
Published: May 2006

Abstract
Chlorination of paraldehyde gave chloroacetaldehydes which were treated with concd sulfuric acid to afford cyclic trimer (3) of chloroacetaldehyde (CA). Depolymerization of 3 yielded pure CA satisfactory.
Novel Naphthalene Derivatives Undergoing Thermal Valence Isomerization to hemi-Dewar-naphthalene
Authors: Miki Sadao , Katayama Tatsuo , Yoshida Zen-ichi 
Published: May 2006

Abstract
1,2,3-Tri-t-butyl-8-methyl- (1a), 1,2,3-tri-t-butyl-6-methyl-8-bromo- (1b), and 1,2,3-tri-t-butyl-8-bromo-naphthalene (1c) were synthesized. They underwent thermally forbidden electrocyclic reaction to give hemi-Dewar-naphthalenes (2a,b,c). Interconversion between 1 and 2 was thermally reversible. Energy profiles for the reactions were determined.
Optical Humidity Sensor Using Reichardt’s Betain Dye-Polymer Composites
Authors: Sadaoka Yoshihiko , Matsuguchi Masanobu , Sakai Yoshiro , Murata Yu-uki 
Published: May 2006

Abstract
By using Reichardt’s betain dye dispersed in poly(methyl methacrylate) thin film, a bifunctional optical humidity sensor was fabricated. The optical intensity and the wavelength of maximum observed at around 780 nm were sensitive to the humidity. The characteristic of the dye dispersed in polymer was also influenced by the hydrogen bond acidity of the polymer matrix.
Enantioselective Construction of Cyclopropane Rings via Asymmetric Simmons-Smith Reaction of Allylic Alcohols
Authors: Ukaji Yutaka , Nishimura Mitsuhiro , Fujisawa Tamotsu 
Published: May 2006

Abstract
The Simmons-Smith reaction starting from allylic alcohols using (R,R)-diethyl tartrate as a chiral auxiliary was found to proceed enantioselectively; i.e., the treatment of allylic alcohols with diethylzinc and diethyl tartrate, followed by the reaction with diethylzinc and diiodomethane, afforded the corresponding cyclopropylmethyl alcohols in optically active form.
Crystallization of Two-Dimentional Chromophore Arrays in Aqueous Chiral Bilayer Membranes
Authors: Nakashima Naotoshi , Nakamura Chikako , Hiraishi Toshiko , Manabe Osamu , Yoshizuka Kazuharu 
Published: May 2006

Abstract
Crystallization behavior for the alignment of an aromatic chromophore in the aqueous chiral bilayer was examined based on its enhanced circular dichroism (CD). It was found that the existence of crystalline phase in the fluid bilayer promotes rapid crystallization of chromophere arrays in the bilayer. We also found that CD spectra oscillate at phase transition region of the bilayer.
Reaction of Tantalum-Alkyne Complexes with Hydrazones. Stereoselective Synthesis of (E)-Allylic Hydrazines
Authors: Takai Kazuhiko , Miwatashi Seiji , Kataoka Yasutaka , Utimoto Kiitiro 
Published: May 2006

Abstract
Treatment of tantalum-alkyne complexes with dimethylhydrazones by the assistance of Me3Al in a mixed solvent of DME, benzene, and THF at 45 °C for 16 h gives (E)-allylic hydrazines stereoselectively.
Regulation of Catalytic Activity of Peptide–Heme Conjugate by Conformational Change with Trifluoroethanol
Authors: Sakamoto Seiji , Fukushima Hidekazu , Kudo Kazuaki 
Published: May 2006

Abstract
A peptide–heme conjugate in which two α-helix segments were covalently coupled at the heme propionates was designed, and the relationship between the structure and the peroxidase-like catalytic activity was examined. The activity and coordination state of heme were regulated by the conformational change of peptide induced upon the addition of trifluoroethanol.
Atrazine-imprinted Microspheres Prepared Using a Microfluidic Device
Authors: Kubo Asami , Shinmori Hideyuki , Takeuchi Toshifumi 
Published: May 2006

Abstract
Atrazine-imprinted microspheres were prepared using a microfluidic device. With a dispersed phase containing atrazine, methacrylic acid, ethylene glycol dimethacrylate, and 2,2-azobis(2,4-dimethylvaleronitrile) and a continuous phase containing poly(vinyl alcohol), droplets could be generated by shearing force of continuous phase in a Y-junction microfluidic device. Monodisperse droplets were polymerized by UV irradiation to yield the imprinted polymer that showed selective binding for atrazine.
The Molecular Identities of the Caenorhabditis elegans Intraflagellar Transport Genes dyf-6, daf-10 and osm-1
Authors: Bell Leslie R , Stone Steven , Yochem John , Shaw Jocelyn E , Herman Robert K 
Published: May 2006

Abstract
The Caenorhabditis elegans genes dyf-6, daf-10, and osm-1 are among the set of genes that affect chemotaxis and the ability of certain sensory neurons to take up fluorescent dyes from the environment. Some genes in this category are known to be required for intraflagellar transport (IFT), which is the bidirectional movement of raft-like particles along the axonemes of cilia and flagella. The cloning of dyf-6, daf-10, and osm-1 are described here. The daf-10 and osm-1 gene products resemble each other and contain WD and WAA repeats. DYF-6, the product of a complex locus, lacks known motifs, but orthologs are present in flies and mammals. Phenotypic analysis of dyf-6 mutants expressing an OSM-6∷GFP reporter indicates that the cilia of the amphid and phasmid dendritic endings are foreshortened. Consistent with genetic mosaic analysis, which indicates that dyf-6 functions in neurons of the amphid sensilla, DYF-6∷GFP is expressed in amphid and phasmid neurons. Movement of DYF-6∷GFP within the ciliated endings of the neurons indicates that DYF-6 is involved in IFT. In addition, IFT can be observed in dauer larvae.
Varicella-Related Hospitalization and Emergency Department Visit Rates, Before and After Introduction of Varicella Vaccine, Among White and Black Children in Hamilton County, Ohio
Authors: Staat Mary Allen , Meinzen-Derr Jareen , Welch Timothy , Roberts Nancy E. , Jamison Linda , Gerber Michael A. , Morrow Ardythe L. 
Published: May 2006

OBJECTIVE. The American Academy of Pediatrics recommended routine use of varicella vaccine in pediatric practice in 1995. We examined the impact of varicella immunization on population-based rates of pediatric varicella-related hospitalizations and emergency department (ED) visits in the years before and after introduction of varicella vaccine.STUDY DESIGN. Discharge data for hospitalizations and ED encounters from 1990 through 2003 were queried for patients &lt;20 years of age with varicella International Classification of Diseases, Ninth Revision, Clinical Modification codes (052.0–052.9) in any diagnostic position. Addresses were geocoded for identification of Hamilton County, Ohio, residents. Rates were calculated according to year, age, and race, with census estimates.RESULTS. During the 14-year study period, there were 3983 incident varicella cases; 335 patients were hospitalized and 3833 were treated only in the ED. The rate of varicella-related hospitalizations decreased from 15.7 cases per 100000 population to 5.5 cases per 100000 population between the prevaccine period (1990–1995) and the postvaccine period (1996–2003); varicella-related ED use decreased from 178.2 cases per 100000 population to 61.2 cases per 100000 population. In the prevaccine period, hospitalization and ED visit rates were significantly higher for black children than for white children. In the postvaccine period, hospitalization rates did not differ according to race but ED visit rates remained significantly higher for black children, compared with white children.CONCLUSIONS. Varicella-related hospitalization and ED visit rates decreased significantly for both white and black children in Hamilton County, Ohio, after the introduction of varicella vaccine, and the racial disparity found before licensure decreased after licensure.
Do Bullied Children Get Ill, or Do Ill Children Get Bullied? A Prospective Cohort Study on the Relationship Between Bullying and Health-Related Symptoms
Authors: Fekkes Minne , Pijpers Frans I.M. , Fredriks A. Miranda , Vogels Ton , Verloove-Vanhorick S. Pauline 
Published: May 2006

OBJECTIVES. A number of studies have shown that victimization from bullying behavior is associated with substantial adverse effects on physical and psychological health, but it is unclear which comes first, the victimization or the health-related symptoms. In our present study, we investigated whether victimization precedes psychosomatic and psychosocial symptoms or whether these symptoms precede victimization.DESIGN. Six-month cohort study with baseline measurements taken in the fall of 1999 and follow-up measurements in the spring of 2000.SETTING. Eighteen elementary schools in the Netherlands.PARTICIPANTS. The study included 1118 children aged 9 to 11 years, who participated by filling out a questionnaire on both occasions of data collection.OUTCOME MEASURES. A self-administered questionnaire measured victimization from bullying, as well as a wide variety of psychosocial and psychosomatic symptoms, including depression, anxiety, bedwetting, headaches, sleeping problems, abdominal pain, poor appetite, and feelings of tension or tiredness.RESULTS. Victims of bullying had significantly higher chances of developing new psychosomatic and psychosocial problems compared with children who were not bullied. In contrast, some psychosocial, but not physical, health symptoms preceded bullying victimization. Children with depressive symptoms had a significantly higher chance of being newly victimized, as did children with anxiety.CONCLUSIONS. Many psychosomatic and psychosocial health problems follow an episode of bullying victimization. These findings stress the importance for doctors and health practitioners to establish whether bullying plays a contributing role in the etiology of such symptoms. Furthermore, our results indicate that children with depressive symptoms and anxiety are at increased risk of being victimized. Because victimization could have an adverse effect on children's attempts to cope with depression or anxiety, it is important to consider teaching these children skills that could make them less vulnerable to bullying behavior.
Pediatric Hospitalists: A Systematic Review of the Literature
Authors: Landrigan Christopher P. , Conway Patrick H. , Edwards Sarah , Srivastava Rajendu 
Published: May 2006

BACKGROUND. Systematic reviews have demonstrated consistently decreased length of stay and costs in internal medicine hospitalist systems. Systematic reviews of pediatric hospitalist systems have not been conducted.OBJECTIVE. Our aim was to determine the effects of pediatric hospitalist systems on length of stay, costs, quality of care, and provider satisfaction and experience.METHODS. We searched PubMed, Medline, Cochrane Library databases, and the Pediatric Academic Societies National Meeting research abstracts for all primary-data studies published or presented on pediatric hospitalist systems. Studies presenting primary data on efficiency, financial performance, clinical outcomes, or family, referring provider, and housestaff experience in hospitalist systems were included; review articles and case studies were excluded. To minimize publication bias, we contacted all primary authors to obtain information about unpublished studies.RESULTS. Of 47 publications reviewed, 20 were primary-data studies that met criteria for inclusion. Six of 7 studies that compared traditional and hospitalist systems of care demonstrated improvements in costs and/or length of stay in pediatric hospitalist systems. The average decrease in cost was 10%; average decrease in length of stay was 10%. Three of 3 economic analyses, however, demonstrate that efficiency gains do not generally translate into revenues for the hospitalist programs themselves; most hospitalist programs are currently losing money. Surveys of families, referring providers, and pediatric residents demonstrate neutral or improved experiences in hospitalist systems, although these data are less comprehensive. Data on quality of care are insufficient to draw conclusions.CONCLUSIONS. Emerging research suggests that pediatric hospitalist systems decrease hospital costs and length of stay without adversely affecting provider, parent, or housestaff experiences. The quality of care in pediatric hospitalist systems is unclear, because rigorous metrics to evaluate quality are lacking. Studies of the processes and outcomes of hospital care are needed.
Epilepsy Surgery in Young Children With Tuberous Sclerosis: Results of a Novel Approach
Authors: Weiner Howard L. , Carlson Chad , Ridgway Emily B. , Zaroff Charles M. , Miles Daniel , LaJoie Josiane , Devinsky Orrin 
Published: May 2006

OBJECTIVE. Tuberous sclerosis complex (TSC) is associated with medically refractory epilepsy and developmental delay in children and usually results from cortical tubers. Seizures that begin in young patients are often refractory and may contribute to development delay. Functional outcome is improved when seizures are controlled at an early age. Previous reports have shown modest benefit from surgical resection of single tubers/seizure foci in older children; however, many children with TSC develop uncontrolled seizures before age 1. To identify patients who might benefit from surgery and to maximize outcome, we used a novel surgical approach in young children that consists of invasive intracranial monitoring, which is typically 3-staged and often bilateral.METHODS. Of 110 consecutive children who underwent epilepsy surgery by a single surgeon in the past 6 years, 25 patients (9 boys and 16 girls) had TSC. At the time of their first surgery at our institution, they were a median age of 4.0 years. A total of 31 separate admissions for epilepsy surgery in these 25 patients were identified. Bilateral electrode placement was performed in 13 children whose seizures could not be lateralized definitively preoperatively, and 22 patients underwent 3-stage surgeries.RESULTS. At 6 months or longer after the initial resection, 21 (84%) children were class I, 2 (8%) children were class II, and 2 (8%) children were class IV. At a mean follow-up of 28 months, 17 (68%) children were class I, 6 (24%) were class II, and 2 (8%) were class III. Four of the 5 children who initially were rejected as surgical candidates because of multifocality and who required initial bilateral electrode study are now seizure-free.CONCLUSIONS. This approach can help to identify both primary and secondary epileptogenic zones in young TSC patients with multiple tubers. Multiple or bilateral seizure foci are not necessarily a contraindication to surgery. Long-term follow-up will determine whether this approach has durable effects.