bluuebunny/crossref_metadata_2025_split huggingface dataset:
Autism spectrum disorder in fragile X syndrome: Communication, social interaction, and specific behaviors
Authors: Kaufmann Walter E. , Cortell Ranon , Kau Alice S.M. , Bukelis Irena , Tierney Elaine , Gray Robert M. , Cox Christiane , Capone George T. , Stanard Pia 
Published: July 2004

AbstractThe present study extends our previous work on social behavior impairment in young males with fragile X syndrome (FraX). Specifically, we evaluated whether the autistic phenomenon in FraX is expressed as a range of behavioral impairments as in idiopathic autism (Aut). We also examined whether there are behaviors, identified as items of the Autism Diagnostic Interview‐Revised (ADI‐R), that in FraX predispose to or differentiate subjects with autism spectrum disorder (ASD) diagnosis. Finally, regression models were utilized to test the relative contribution of reduced communication and socialization skills to ADI‐R scores and diagnoses. A cohort of 56 boys (3–8 years) with FraX was examined in terms of scores on measures of cognition (IQ was a co‐variate in most analyses.), autistic behavior, problem/aberrant behavior, adaptive behavior, and language development. We found that, indeed, in terms of problem behavior and adaptive skills, there is a range of severity from FraX + Aut to FraX + PDD (Pervasive Developmental Disorder) to FraX + none. ADI‐R items representing “Play” types of interaction appear to be “susceptibility” factors since they were abnormal across the FraX cohort. Integrated regression models demonstrated that items reflecting complex social interaction differentiated the FraX + ASD (Aut + PDD) subgroup from the rest of the FraX cohort, while abnormalities in basic verbal and non‐verbal communication distinguished the most severely affected boys with FraX + Aut from the milder FraX + PDD cohort. Models incorporating language, adaptive communication, and adaptive socialization skills revealed that socialization was not only the main influence on scores but also a predictor of ASD diagnosis. Altogether, our findings demonstrate that the diagnosis of ASD in FraX reflects, to a large extent, an impairment in social interaction that is expressed with variable severity in young males with FraX. © 2004 Wiley‐Liss, Inc.
Transmission of ring chromosome 13 from a mother to daughter with both having a 46,XX, r(13)(p13q34) karyotype
Authors: Bedoyan Jirair K. , Flore Leigh Anne , Alkatib Aziz , Ebrahim Salah A. , Bawle Erawati V. 
Published: July 2004

AbstractRing chromosomes are thought to be the result of breakage in both arms of a chromosome, with fusion of the points of fracture and loss of the distal fragments. Another mechanism of ring formation is believed to be the simple fusion of chromosome ends with preservation of telomeric and subtelomeric sequences. Ring chromosome 13 was first described in 1968 and its incidence estimated at 1 in 58,000 live births. Severe phenotypes associated with large deletions of 13q have been described as “ring chromosome 13 syndrome.” Features of the “ring chromosome 13 syndrome” include mental retardation (often severe), growth retardation, microcephaly, facial dysmorphism, and hand, foot or toe abnormalities. We report on a case of a mother and daughter with r(13) and mild phenotypes. Our patient, IA, had chromosome analysis performed at about 4½ years of age due to some developmental delay. This revealed 46,XX, r(13)(p13q34) karyotype with no loss of any chromosomal band. Her mother, EA, was subsequently found to have the same ring 13. IA's maternal grandmother had a normal karyotype while her maternal grandfather was unavailable for testing. Fluorescence in situ hybridization (FISH) analysis showed loss of a specific subtelomeric 13q region in r(13) in the mother. Clinically, IA had macular hyperpigmentation on the chin and mild delay in speech and fine motor skills. EA, 22 years of age, had mild short stature and borderline mental retardation. To our knowledge, this is the first report of a case of familial transmission of r(13). We compare phenotypes of our cases with those from other reported cases of r(13) and discuss the possible mechanism of formation of this ring chromosome. © 2004 Wiley‐Liss, Inc.
CD studies on films of amyloid proteins and polypeptides: Quantitative g‐factor analysis indicates a common folding motif
Authors: McPhie Peter 
Published: July 2004

AbstractIrrespective of the constituent protein, all amyloid fibrils show similar morphology in the electron microscope and x‐ray diffraction patterns characteristic of a “cross‐β” structure, with extended β‐strands perpendicular to the fibril's long axis. Little is known about the amount or type of this structure. I have measured CD spectra of films formed from a number of amyloid proteins and polypeptides, and estimated their contents of extended secondary structure, by analysis of their g‐factor spectra, the ratio of the CD and absorbance signals (P. McPhie, Analytical Biochemistry, 2001, Vol. 293, pp. 109–119). Amyloid films of Aβ‐(1–40) peptide, β‐2‐microglobulin, insulin, and three homopolypeptides show very intense CD spectra, compatible with the presence of a β‐helix‐like structure, arranged in a common framework in the fibrils. The extent of this structure was estimated as 45–80% in the protein fibrils and 30–80% in the polypeptide fibrils. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
Conformational states of HRPA1 induced by thermal unfolding: Effect of low molecular weight solutes
Authors: Carvalho Ana Sofia L. , Santos Andrea M. , Neves‐Petersen Maria Teresa , Petersen Steffen B. , Aires‐Barros Maria Raquel , Pinho e Melo Eduardo 
Published: July 2004

AbstractFluorescence, CD, and activity measurements were used to characterize the different conformational states of horseradish peroxidase A1 induced by thermal unfolding. Picosecond time‐resolved fluorescence studies showed a three‐exponential decay dominated by a picosecond lifetime component resulting from energy transfer from tryptophan to heme. Upon thermal unfolding a decrease in the preexponential factor of the picosecond lifetime and an increase in the quantum yield were observed approaching the characteristics observed for apoHRPA1. The fraction of heme‐quenched fluorophore decreased to 0.4 after unfolding as shown by acrylamide quenching. A new unfolding pathway for HRPA1 was proposed and the effect of the low molecular weight solutes trehalose, sorbitol, and melezitose on this pathway was analyzed. Native HRPA1 unfolds with an intermediate between the native and the unfolded conformation. The unfolded conformation can refold to the native state or to a native‐like conformation with no calcium ions upon cooling or can give an irreversible denatured state. The refolded conformation with no calcium ions was clearly identified in a second thermal scan in the presence of EDTA and shows secondary and tertiary structures, heme reincorporation in the cavity, and at least 59% of activity. Melezitose stabilized the refolded Ca2+‐depleted protein and induced a more complex mechanism for heme disruption. The effect of sorbitol and trehalose were mainly characterized by an increase in the temperature of unfolding. © 2004 Wiley Periodicals, Inc. Biopolymers, 2004
Superparamagnetic adsorbents for high‐gradient magnetic fishing of lectins out of legume extracts
Authors: Heebøll‐Nielsen Anders , Dalkiær Mikkel , Hubbuch Jürgen J. , Thomas Owen R.T. 
Published: July 2004

AbstractThis work presents the development, testing, and application in high‐gradient magnetic fishing of superparamagnetic supports for adsorption of lectins. Various approaches were examined to produce affinity, mixed mode, and hydrophobic charge induction type adsorbents. In clean monocomponent systems affinity supports created by direct attachment of glucose or maltose to amine‐terminated iron oxide particles could bind concanavalin A at levels of up to ≈ 280 mg g−1 support with high affinity (≈ 1 μM dissociation constants). However, the best performance was delivered by adsorbents featuring coupled tentacular dextran chains displaying a maximum binding capacity of 238 mg g−1 and a dissociation constant of 0.13 μM. Adsorbents derivatized with mixed mode or hydrophobic charge induction ligands likewise demonstrated very high capacities for both concanavalin A and Lens culinaris agglutinin (≥ 250 mg g−1) with dissociation constants in the micromolar range, though neither of these systems showed any selectivity for lectins in leguminous extracts.When the affinity supports were applied to carbohydrate containing legume extracts only the dextran‐linked adsorbents supplied sufficient competition to dissolved sugars to selectively bind concanavalin A in an extract of jack beans. The dextran‐linked supports were employed in a high‐gradient magnetic fishing experiment, in which concanavalin A was purified to near homogeneity from a crude, unclarified extract of jack beans. © 2004 Wiley Periodicals, Inc.
Compatibility of column inlet and adsorbent designs for processing of corn endosperm extract by expanded bed adsorption
Authors: Menkhaus Todd J. , Glatz Charles E. 
Published: July 2004

AbstractCorn has emerged as a viable host for expression of recombinant proteins; targeted expression to the endosperm has received particular attention. The protein extracts from corn endosperm differ from those of traditional hosts in regard to the nature of residual solids and extracted matrix contaminants. Each of these differences presents reasons for considering expanded bed adsorption for product capture and new considerations for limitations of the method. In this work three inlet‐flow distribution devices (mesh, glass ballotini, and localized mixing) and six adsorbents with different physical (size and density), chemical (ligand), and base matrix properties were evaluated to determine conditions compatible with processing of crude corn endosperm extract by expanded bed adsorption.Of the inlet devices evaluated, the design with localized mixing at the inlet (as produced commercially by UpFront Chromatography A/S, Copenhagen, DK) allowed solids up to 550 μm into the column without clogging for all flow rates evaluated. A mesh at the inlet with size restriction of either 50 μm or 80 μm became clogged with very small corn particles (< 44 μm). When glass ballotini was used, large particles (550 μm) passed through for high flow rates (570 cm/h), but even small (< 44 μm) particles became trapped at a lower flow rate (180 cm/h). The physical and chemical properties of the resin determined whether solids could be eluted. The denser UpFront adsorbents allowed for complete elution of larger and more concentrated corn solids than the currently available Amersham Streamline adsorbents (Amersham Biosciences, Piscataway, NJ) as a result of the former's higher flow rate for the desired 2× expansion (570 cm/h for UpFront vs. 180 cm/h for Streamline). All corn solids < 162 μm eluted through nonderivatized UpFront resin. Larger corn solids began to accumulate due to their elevated sedimentation velocities. Feeds of < 44 μm solids at 0.45% and 2.0% dry weight successfully eluted through ion exchange adsorbents (DEAE and SP) from UpFront. However, significant accumulation occurred when the solids size increased to a feed of < 96 μm solids, thus indicating a weak interaction between corn solids and both forms of ion exchange ligands. Expanded beds operated with Streamline ion exchange adsorbents (DEAE and SP) did not allow full elution of corn solids of < 44 μm. A hyperdiffuse style EBA resin produced by Biosepra (Ciphergen Biosystems, Fremont, CA) with CM functionality showed a severe interaction with corn solids that collapsed the expanded bed and could not be eliminated with elevated flow rates or higher salt concentration. © 2004 Wiley Periodicals, Inc.
Galactose Oxidase Models: Solution Chemistry, and Phenoxyl Radical Generation Mediated by the Copper Status
Authors: Michel Fabien , Thomas Fabrice , Hamman Sylvain , Saint‐Aman Eric , Bucher Christophe , Pierre Jean‐Louis 
Published: July 2004

AbstractGalactose oxidase (GO) is an enzyme that catalyzes two‐electron oxidations. Its active site contains a copper atom coordinated to a tyrosyl radical, the biogenesis of which requires copper and dioxygen. We have recently studied the properties of electrochemically generated mononuclear CuII‐phenoxyl radical systems as model compounds of GO. We present here the solution chemistry of these ligands under various copper and dioxygen statuses: N3O ligands first chelate CuII, leading, in the presence of base, to [CuII(ligand)(CH3CN)]+ complexes (ortho‐tert‐butylated ligands) or [(CuII)2(ligand)2]2+ complexes (ortho‐methoxylated ligands). Excess copper(II) then oxidizes the complex to the corresponding mononuclear CuII‐phenoxyl radical species. N2O2 tripodal ligands, in the presence of copper(II), afford directly a copper(II)‐phenoxyl radical species. Addition of more than two molar equivalents of copper(II) affords a CuII–bis(phenoxyl) diradical species. The donor set of the ligand directs the reaction towards comproportionation for ligands possessing an N3O donor set, while disproportionation is observed for ligands possessing an N2O2 donor set. These results are discussed in the light of recent results concerning the self‐processing of GO. A path involving copper(II) disproportionation is proposed for oxidation of the cross‐linked tyrosinate of GO, supporting the fact that both copper(I) and copper(II) activate the enzyme.
The early identification of dyslexia: Children with English as an additional language
Authors: Hutchinson Jane M. , Whiteley Helen E. , Smith Chris D. , Connors Liz 
Published: July 2004

AbstractIt is generally accepted that dyslexia should be identified early for interventions to have maximum effect. However, when children speak English as an additional language (EAL), diagnosis is more complex and there is concern that these children tend to be under‐identified. This paper reports a longitudinal study following the development of phonological awareness skills in relation to progress in learning to read with a cohort of British Asian children learning EAL and their monolingual peers. It also sought to determine the usefulness of a measure of phonological skills for the identification of dyslexic‐type difficulties in children learning EAL. Analysis revealed that both cohorts achieved similar levels of reading accuracy in school Years 2, 4 and 6, with higher levels of reading comprehension for the monolingual children and faster reading fluency for children learning EAL in each school year. There was a similar pattern of relationships between the reading measures and measures of phonological awareness for both groups of children. However, monolingual children achieved higher levels of rhyme detection and alliteration fluency whilst the children learning EAL achieved faster number naming times.Overall, a phonological assessment battery was useful in identifying reading accuracy related difficulties in both groups of children. However, concerns are raised about the sensitivity of such measures following the introduction of the Literacy Hour. Copyright © 2004 John Wiley & Sons, Ltd.
Working memory: Its role in dyslexia and other specific learning difficulties
Authors: Jeffries Sharman , Everatt John 
Published: July 2004

AbstractThis paper reports a study contrasting dyslexic children against a control group of children without special educational needs (SEN) and a group with varied SENs. Children's abilities were compared on tasks assessing phonological processing, visuo‐spatial/motor coordination and executive/inhibitory functioning; being targeted for assessment based on theoretical proposals related to the working memory model. Primary and secondary school level children were tested: 21 assessed as dyslexic with no comorbid difficulties, 26 children assessed with difficulties including dyspraxia, emotional/behavioural problems and attention deficits, 40 children with no known education‐related deficits were controls. Results indicated both SEN groups performed worse than controls on working memory phonological loop measures. However, SEN groups could only be differentiated on phonological awareness measures: the dyslexics showing lower scores. Dyslexics performed as well as controls on working memory visuo‐spatial scratch pad measures and one of two additional visual–motor coordination tasks, whereas the performance of the other SEN children was lowest on the majority of these measures. Central executive and interference measures engendered mixed performances, both SEN groups showing evidence of deficits in one or more of these areas of functioning, although, of the two SEN groups, the dyslexics seem to have performed the worse when digit name processing was required. Copyright © 2004 John Wiley & Sons, Ltd.
Lithium tert‐Butyl[phenyl(2,2,6,6‐tetramethylpiperidino)boryl]amide: A Versatile Reagent
Authors: Braun Ulrike , Habereder Tassilo , Nöth Heinrich 
Published: July 2004

AbstractA new synthesis of tmp(PhB)N(tBuNLi) (1, tmp = 2,2,6,6‐tetramethylpiperidino) is presented. Compound 1 reacts with many group 13−15 halides, as well as with BH3·THF, to afford, in most cases, compounds of the type tmp(PhB)NtBu−ERn−1 (E = B, Al, Ga, In, Ge, Sn, P, As, Sb, and R = H, Me, Hal). The borane, alane, gallane and indane derivatives have cyclic structures, as shown by X‐ray structure determinations, whereas ERn−1 = GeCl3, SnMe3, SnMe2Cl, SnCl, catecholatophosphanyl, AsCl2 and SbCl2 are noncyclic, although the arsane and stibane derivatives show weak intramolecular E−N coordination to the tmp−N atom. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004)
Chemopreventive effects of vanadium toward 1,2‐dimethylhydrazine‐induced genotoxicity and preneoplastic lesions in rat colon
Authors: Kanna P. Suresh , Mahendrakumar C.B. , Indira B.N. , Srivastawa Sunil , Kalaiselvi K. , Elayaraja T. , Chatterjee Malay 
Published: July 2004

AbstractIn the present study, we have evaluated the antitumor effects of vanadium by monitoring DNA damage and chromosomal aberrations (CAs) during the early preneoplastic stage of 1,2‐dimethylhydrazine (1,2‐DMH)‐induced colon cancer in male rats. Treatment with 20 mg/kg 1,2‐DMH for 6 weeks resulted in the formation of aberrant crypt foci (ACF), a putative preneoplastic lesion associated with colon cancer development, while cotreatment with ammonium monovanadate (0.5 ppm in the drinking water) reduced ACF formation by 50% (P < 0.001). The 6‐week treatment with 1,2‐DMH also resulted in significantly higher levels of DNA damage in rat colon as measured by the Comet assay (higher mean values for length‐to‐width ratios (L:W) of DNA mass (P < 0.01) and mean frequencies of cells with comets (P < 0.001)). The vanadium cotreatment reduced DNA damage in colon cells by 32% (P < 0.02 and P < 0.001 for L:W and tailed cells, respectively). 1,2‐DMH treatment also produced a 10‐fold increase in the frequency of CAs in rat colon (P < 0.001), while cotreatment with vanadium resulted in a reduction in CAs after 2, 4, and 6 weeks of 1,2‐DMH exposure (P < 0.01). Analysis of antioxidant defense enzyme activity in colonic mucosa indicated that glutathione reductase and catalase activities were increased in 1,2‐DMH‐treated rats; cotreatment with vanadium reduced these activities when compared to the carcinogen control (P < 0.001 and P < 0.02). These results demonstrate that the early protective effect of vanadium in chemically induced rat colon carcinogenesis may be mediated by a reduction of carcinogen‐induced DNA damage. Environ. Mol. Mutagen. 44:113–118, 2004. © 2004 Wiley‐Liss, Inc.
In vivo mutation in gene A of splenic lymphocytes from ΦX174 transgenic mice
Authors: Valentine Carrie R. , Raney Jessica L. , Shaddock Joseph G. , Dobrovolsky Vasily N. , Delongchamp Robert R. 
Published: July 2004

AbstractSingle‐burst analysis was applied to a forward assay for gene A mutation in splenic lymphocytes of ΦX174 transgenic mice for the purpose of optimizing analytical parameters for identifying in vivo mutations. The effect of varying the cutoff value for an in vivo burst on induced mutant frequency, fold increase, and the significance of the difference between control and N‐ethyl‐N‐nitrosourea (ENU)‐treated mice was calculated by two different methods. The plating density was reduced to an average of less than 10 background mutant plaques per aliquot in order to separate in vitro bursts. The spectrum of mutations contributing < 60 plaques per aliquot from control animals was not significantly different from the control spectra from E. coli or transgenic ΦX174 cells in culture. The mutant spectra from ENU‐treated animals was highly different between mutant bursts of > 80 plaques per aliquot compared to mutations contributing < 60 plaques per aliquot (P < 0.000001), the former fitting the spectrum expected for ENU‐induced mutations. The latter spectrum was also different from control animals and E. coli (P < 0.000001), suggesting the difference was caused by ex vivo mutation. With the mutations found in this study, the total number of reported target sites for gene A is now 33. The results support the interpretation that, in contrast to results for the lacI transgene, 100% of mutants isolated in gene A from control animals and cells were fixed in E. coli. We attribute the difference between the two genes to hot‐spot sites for mutation in gene A and to a testable hypothesis that the mosaic plaque assay for the lacI transgene underestimates the frequency of ex vivo mutants. Environ. Mol. Mutagen. 44:128–150, 2004. Published 2004 Wiley‐Liss, Inc.
Comparison of two particulate hexavalent chromium compounds: Barium chromate is more genotoxic than lead chromate in human lung cells
Authors: Wise Sandra S. , Schuler Julie H.C. , Holmes Amie L. , Katsifis Spiros P. , Ketterer Michael E. , Hartsock Wendy J. , Zheng Tongzhang , Wise John Pierce 
Published: July 2004

AbstractParticulate hexavalent chromium [Cr(VI)] compounds are well‐established human lung carcinogens. However, their carcinogenic mechanisms are poorly understood as most investigators have used soluble Cr(VI) compounds. Recent work from our laboratory has found that barium chromate (BC) is also cytotoxic and clastogenic. To understand how BC relates to existing data on other particulate Cr(VI) compounds, we compared its cytotoxicity and clastogenicity with lead chromate (LC), which has been used as a prototypical particulate Cr(VI) compound, in WTHBF‐6 cells, a near‐normal human lung cell line. We found that BC is a more potent cytotoxicant, inducing 67%, 12%, 3%, and 0% relative survival at concentrations of 0.1, 0.5, 1, and 5 μg/cm2, respectively, while LC induced 90%, 71%, 43%, and 15% survival at these same concentrations. We found that BC was also more clastogenic, damaging 22% and 49% of metaphase cells at 0.1 and 0.5 μg/cm2, and causing complete cell cycle arrest at 1 and 5 μg/cm2. By contrast, 0.1, 0.5, and 1.0 μg/cm2 LC damaged 10%, 27%, and 37% of metaphase cells, respectively, and complete cell cycle arrest was not observed until a concentration of 5 μg/cm2 was reached. We found that BC and LC both partially dissolved in complete medium in the presence of cells, producing similar extracellular concentrations. Both compounds were also comparable with respect to particle uptake and the amount of intracellular Cr ions. Considering previous reports showing that lead ions were inactive and that sodium chromate and LC have similar clastogenic potencies, these data suggest that BC genotoxicity may not be solely mediated by Cr ions, but also involve some clastogenic activity of barium ions. Environ. Mol. Mutagen. 44:156–162, 2004. © 2004 Wiley‐Liss, Inc.