bluuebunny/crossref_metadata_2025 huggingface dataset:
Oral Impacts on Daily Performance in Norwegian adults: the influence of age, number of missing teeth, and socio‐demographic factors
Authors: Åstrøm A. N. , Haugejorden O. , Skaret E. , Trovik T. A. , Klock K. S.
Published: March 2006

This study investigates the relationships among socio–demographic factors, dental status, and impaired oral health‐related quality of life (OHRQoL) using a translation into Norwegian of the Oral Impacts on Daily Performance (OIDP) inventory. Data were collected as part of the Central Bureau of Statistics (CBS) OMNIBUS survey in Norway. The CBS drew a two‐stage proportionate random sample, comprising 2,000 residents aged 16–79 yr, from the national population register. Information was available for 1,309 individuals (response rate 66.0%) who completed telephone interviews in November and December 2003. A total of 18.3% (95% confidence interval: 16.2–20.4) reported that an oral problem had affected at least one daily oral performance during the 6 months preceding the survey. The proportion of adults who confirmed impacts varied from 11.3% (eating) to 2.1% (social contact). Multiple logistic regression analysis revealed statistically significant disparities regarding respondents' age, residential area, dental attendance, and number of remaining teeth. The prevalence of OIDP in the Norwegian population was modest, but varied systematically with both socio–demographic and oral health‐related factors. The consistently declining OIDP with increasing age after controlling for dental status suggests age‐related changes of participants' values and expectations.
Structure of the periodontium in cathepsin C‐deficient mice
Authors: De Haar Susanne F. , Tigchelaar‐Gutter Wikky , Everts Vincent , Beertsen Wouter
Published: March 2006

Papillon–Lefevre syndrome is characterized by increased susceptibility to early‐onset periodontitis and is caused by mutations in the cathepsin C gene. How deficiency of the enzyme relates to an increased periodontal infection risk is still not entirely clear. One possibility is that the deficiency leads to changes in the structure of the periodontal tissues as a result of which its barrier function to pathogens is compromised. We studied the structure of the periodontium in 9‐month‐old cathepsin C‐deficient mice (cathepsin C–/–) and compared this with age‐matched wild‐type mice. Our observations showed that the overall structure of the gingiva, periodontal ligament, alveolar process, and cementum layer are normal in cathepsin C–/– mice, with one exception, namely that epithelial rests of Malassez in the periodontal ligament of the cathepsin C–/– mice are slightly enlarged. In both experimental and control animals, we noted cyst formation in rests of Malassez. No signs of periodontal infection were observed. It is concluded that cathepsin C deficiency does not lead to major changes in the structure of the periodontium.
Measuring stair use in two office buildings: a comparison between an objective and a self‐reported method
Authors: Engbers L. H. , Van Poppel M. N. M. , Van Mechelen W.
Published: March 2006

Introduction/purpose: Measuring stair use reliably and objectively is complicated and difficult. In this study, stair use was measured at an individual level by using an innovative registration system and was compared with self‐reported data. The purpose of this study was to gain an insight into the comparability of self‐reported stair use vs objectively measured stair use.

Methods: Self‐reported and objective stair use was measured in two worksites and was operationalized as how often a subject uses the stairs per week (i.e., stair‐use frequency) and the number of floors covered (up or down) in a week with each use. Analyses were performed by means of the intraclass correlation coefficients (ICCs).

Results: A number of significant differences in stair use between worksites were found. ICCs of 0.55 and 0.24 for stair‐use frequency were found in worksites 1 and 2, respectively. The ICCs for the number of floors covered were lower at 0.39 and 0.19 for worksites 1 and 2, respectively.

Conclusion: The comparability of self‐reported and objectively measured stair use is moderate to poor, and given the independent measurement errors of both methods, this might have been expected. Comparability seemed to be dependent on worksite characteristics.
Strain rate and tissue tracking imaging in quantitation of left ventricular systolic function in endurance and strength athletes
Authors: Poulsen S. H. , Hjortshøj S. , Korup E. , Poenitz V. , Espersen G. , Søgaard P. , Suder P. , Egeblad H. , Kristensen B. Ø.
Published: March 2006

Aim: The aim of this study was to assess the impact of long‐term physical training on left ventricular longitudinal contraction by strain rate analysis and tissue tracking imaging.

Methods and results: The study population comprised 17 male elite endurance and 15 male elite strength athletes and 12 male control subjects of similar age. Tissue Doppler imaging was recorded in the apical views and used for analysis of the longitudinal systolic myocardial velocity, annular diastolic velocities, strain rate and tissue tracking. Left ventricular mass index was significantly increased in both endurance athletes (209±40 g/m2) and strength athletes (138±38 g/m2) compared with normal subjects (96±20 g/m2, P<0.001). Tissue tracking score index and mean strain rate of the 16 segments were significantly increased in strength athletes (7.9±1.1 mm and –1.4±0.3 s−1, respectively) compared with endurance athletes (7.5±0.9 mm and –1.0±0.4 s−1, P<0.01 for both) and normal subjects (7.4±1.0 mm and −1.0±0.3 s−1, P<0.01 for both).

Conclusion: Despite significant left ventricular hypertrophy and extensive training in elite athletes, we found normal longitudinal left ventricular systolic function, and in strength athletes performing isometric exercise even increased function.
Physical fitness profile of elite athletes with intellectual disability
Authors: Van de Vliet P. , Rintala P. , Fröjd K. , Verellen J. , Van Houtte S. , Daly D. J. , Vanlandewijck Y. C.
Published: March 2006

The aim of this study was to investigate the physical fitness profile of high‐performance athletes with intellectual disability (ID) in comparison with able‐bodied individuals.

Methods: Participants were 231 male and 82 female athletes. All evaluations were done using the EUROFIT physical fitness test.

Results: In comparison with population data, both male and female athletes with ID score better for flexibility and upper body muscle endurance, but have similar or lower values for running speed, speed of limb movement, and strength measures. Compared with age‐matched physical education students, male athletes with ID score better for running speed and flexibility, and worse for strength. Female athletes with ID score not different from able‐bodied individuals for flexibility, running speed, and upper body muscle endurance, but worse for strength measures. Athletes with ID also have poorer cardio respiratory endurance capacity compared with sportive peers without ID. Furthermore, male athletes have a more differentiated profile depending upon their sports discipline, compared with female athletes.

Conclusion: It can be concluded that high‐performance athletes with ID reach physical fitness levels that are equal to or lower than those of able‐bodied sportive counterparts. Further research should investigate the importance of reduced muscle strength to be the limiting factor.
Cytoplasmic Tails of SialT2 and GalNAcT Impose Their Respective Proximal and Distal Golgi Localization
Authors: Uliana Andrea S. , Giraudo Claudio G. , Maccioni Hugo J. F.
Published: March 2006

Complex glycolipid synthesis is catalyzed by different glycosyltransferases resident of the Golgi complex. Most of them are type II membrane proteins comprising a lumenal, C‐terminal domain linked to an N‐terminal domain (Ntd) constituted by a short cytoplasmic tail (ct), a transmembrane, and a lumenal stem regions. They concentrate selectively in different sub‐Golgi compartments, in an overlapped manner, acting in succession in the addition of sugars to acceptor glycolipids. The Ntds are sufficient to localize glycosyltransferases in the Golgi complex, but it is not clear whether they also confer selective concentration in sub‐Golgi compartments. Here, we studied whether the Ntd of SialT2, localized in the proximal Golgi, and the one of GalNAcT, a trans/TGN Golgi‐concentrated enzyme, concentrate reporter proteins in the corresponding sub‐Golgi compartment. The sub‐Golgi concentration of the Ntds fused to spectral variants of the GFP was determined in CHO‐K1 cells from their behavior upon addition of brefeldin A. Fluorescence microscopy and subcellular fractionation showed that the SialT2 Ntd concentrates in a proximal sub‐Golgi compartment – and that of GalNAcT in TGN elements. Exchanging the transmembrane region and the cts of SialT2 and GalNAcT indicates that information for proximal or distal Golgi concentration is associated with the cts.
Oral transmission of HIV, reality or fiction? An update
Authors: Campo J , Perea MA , Del Romero J , Cano J , Hernando V , Bascones A
Published: March 2006

Human immunodeficiency virus (HIV) and many other viruses can be isolated in blood and body fluids, including saliva, and can be transmitted by genital–genital and especially anal–genital sexual activity. The risk of transmission of HIV via oral sexual practices is very low. Unlike other mucosal areas of the body, the oral cavity appears to be an extremely uncommon transmission route for HIV. We present a review of available evidence on the oral–genital transmission of HIV and analyse the factors that act to protect oral tissues from infection, thereby reducing the risk of HIV transmission by oral sex. Among these factors we highlight the levels of HIV RNA in saliva, presence of fewer CD4+ target cells, presence of IgA antibodies in saliva, presence of other infections in the oral cavity and the endogenous salivary antiviral factors lysozyme, defensins, thrombospondin and secretory leucocyte protease inhibitor (SLPI).
Effects of Emdogain on osteoblast gene expression
Authors: Carinci F , Piattelli A , Guida L , Perrotti V , Laino G , Oliva A , Annunziata M , Palmieri A , Pezzetti F
Published: March 2006

Objective:  Emdogain (EMD) is a protein extract purified from porcine enamel and has been introduced in clinical practice to obtain periodontal regeneration. EMD is composed mainly of amelogenins (90%), while the remaining 10% is composed of non‐amelogenin enamel matrix proteins such as enamelins, tuftelin, amelin and ameloblastin. Enamel matrix proteins seem to be involved in root formation. EMD has been reported to promote proliferation, migration, adhesion and differentiation of cells associated with healing periodontal tissues in vivo.

Design:  How this protein acts on osteoblasts is poorly understood. We therefore attempted to address this question by using a microarray technique to identify genes that are differently regulated in osteoblasts exposed to enamel matrix proteins.

Results:  By using DNA microarrays containing 20 000 genes, we identified several upregulated and downregulated genes in the osteoblast‐like cell line (MG‐63) cultured with enamel matrix proteins (Emd). The differentially expressed genes cover a broad range of functional activities: (i) signaling transduction, (ii) transcription, (iii) translation, (iv) cell cycle regulation, proliferation and apoptosis, (v) immune system, (vi) vesicular transport and lysosome activity, and (vii) cytoskeleton, cell adhesion and extracellular matrix production.

Conclusions:  The data reported are the first genome‐wide scan of the effect of enamel matrix proteins on osteoblast‐like cells. These results can contribute to our understanding of the molecular mechanisms of bone regeneration and as a model for comparing other materials with similar clinical effects.
Cheilitis as a variation of Candida‐associated lesions
Authors: Terai H , Shimahara M
Published: March 2006

Objective:  Occasionally, the clinical diagnosis of Candida‐associated lesion is difficult because of a variety of its clinical manifestations. There have been a few reports on Candida‐associated lip lesion except angular cheilitis. In this paper, we investigate the relation of Candida in persistent lesions of the lip.

Subjects and methods:  The present study includes consecutive nine patients with persistent erosive lip lesion. For each patient the age at presentation, gender, duration of the disease, other symptoms or signs, complete medical history and prior treatment or medications for the symptom were obtained. Then, mycological examination and the direct cytologic examination were performed.

Results:  The reported average duration of the disease was 7 months. Six of nine patients had received prior treatments with topical steroids at the other clinic, which failed to resolve their symptoms. Six of nine patients had a predisposing factor for candidiasis. In the culture examination, Candida albicans were isolated in seven patients (77.8%). Five of nine patients received the direct cytologic examination, and four of them revealed pseudohyphae of fungi. The anti‐fungal treatment was miconazol gel 25 mg four times per day, and average duration of the treatment was 2 weeks. The outcome was as follows: complete remission in five, remarkable response in two and no response in two.

Conclusion:  Our results suggested that one form of the varieties of Candida‐associated lesions might be considered in the case of lip lesion with unknown origin that was persistent and ineffective to the topical steroids treatment.
Determining prey distribution patterns from stomach‐contents of satellite‐tracked high‐predators of the Southern Ocean
Authors: C. Xavier J. , A. Tarling G. , P. Croxall J.
Published: March 2006

The distribution of many cephalopod, crustacean and fish species in the Southern Ocean, and adjacent waters, is poorly known, particularly during times of the year when research surveys are rare. Analysing the stomach samples of satellite‐tracked higher predators has been advocated as a potential method by which such gaps in knowledge can be filled. We examined the viability of this approach through monitoring wandering albatrosses Diomedea exulans at their colony on Bird Island, South Georgia (54°S, 38°W) over the winters (May–July) of 1999 and 2000. At this time, these birds foraged in up to three different water‐masses, the Antarctic zone (AZ), the sub‐Antarctic zone (SAZ) and the sub‐Tropical zone (STZ), which we defined by contemporaneous satellite images of sea surface temperature. A probabilistic model was applied to the tracking and diet data collected from 38 birds to construct a large‐scale map of where various prey were captured. Robustness/sensitivity analyses were used to test model assumptions on the time spent foraging and relative catch efficiencies and to evaluate potential biases associated with the model. We were able to predict the distributions of a wide number of cephalopod, crustacean of fish species. We also discovered some of the limitations to using this type of data and proposed ways to rectify these problems.
Unexpected Products in Reactions of Double-C,N-Chelated Diorganotin(IV) Dibromide with Cyclopentadienyl- and Fluorenyllithium
Authors: Padělková Zdeňka , Císařová Ivana , Růžička Aleš , Holeček Jaroslav
Published: March 2006

From the reactions of bis{2-[(dimethylamino)methyl]phenyl}tin(IV) dibromide with two equivalents of cyclopentadienyl- or fluorenyllithium in THF, unexpected products [2-(CH3)2NCH2C6H4]2Sn(μ-η1:η1-C5H4)(μ-O)Sn[2-(CH3)2NCH2C6H4]2 (2) and [2-(CH3)2NCH2C6H4]2Sn(OC13H9)Br (3), respectively, were isolated. These compounds were characterized by elemental analysis, NMR and X-ray diffraction techniques. The tin atoms in 2 are pseudotetrahedrally coordinated, each of them by two carbons of ligand, oxygen and the bridging carbon originated from μ-η1:η1-planar cyclopentadienyl moiety. The geometry of 3 is described as a distorted tetragonal pyramid with both ligand carbon atoms, bromine and one of nitrogen atoms in the base and oxygen atom in the vertex position.
Familial tumoral calcinosis and testicular microlithiasis associated with a new mutation of GALNT3 in a white family
Authors: Campagnoli M F , Pucci A , Garelli E , Carando A , Defilippi C , Lala R , Ingrosso G , Dianzani I , Forni M , Ramenghi U
Published: March 2006

Background:Familial tumoral calcinosis (FTC) is a rare autosomal recessive disease characterised by the development of multiple calcified masses in periarticular soft tissues; GALNT3 gene mutations have recently been described in an African American and in a Druse Arab family with FTC.

Objective:To report the clinical and histological features caused by a new GALNT3 mutation in a white family.

Results:Homozygosity for the nonsense mutation Lys463X was found in both affected siblings, who displayed a classic phenotype, the male also having testicular microlithiasis. He is the first subject described with testicular microlithiasis in FTC.

Conclusions:The high testicular expression of GALNT3 suggests that the gene alteration could act locally by causing deposition of calcium, and the testis may be an underestimated site of calcification in FTC. Autoimmune diseases are present in several members of the family. Although immune disorders have been described in FTC, autoimmunity does not segregate with the GALNT3 mutation in this family.
Intrapatellar tendon lipoma with chondro-osseous differentiation: detection of HMGA2-LPP fusion gene transcript
Authors: Matsui Y , Hasegawa T , Kubo T , Goto T , Yukata K , Endo K , Bando Y , Yasui N
Published: March 2006

A 54 year old man developed an unusual lipoma in the patellar tendon, consisting of a fibro-adipose component and a chondro-osseous component. The fibro-adipose component contained mature adipocytes, lipoblasts, and fibroblasts; the chondro-osseous component showed typical endochondral bone formation. Molecular analysis showed that the identical HMGA2-LPP fusion transcript—characteristic of lipoma, parosteal lipoma, and pulmonary chondroid hamartoma—was detectable in the both components.
Rapid fixation of brains: a viable alternative?
Authors: Sharma M , Grieve J H K
Published: March 2006

Aim:Recent events surrounding postmortem practices have necessitated several changes in the way necropsies are conducted both within the medicolegal and hospital settings. These changes have resulted in a striking reduction in the frequency of brain retention for neuropathological examination. Aberdeen Royal Infirmary, responding quickly to rising concerns among bereaved relatives regarding organ retention, instituted a change in practice regarding the examination of brains at necropsy as early as 2001. The new protocol involved subjecting the brain to rapid fixation using combined immersion and perfusion techniques. This allows return of the organ to the body without unreasonable delay to the funeral. In this article, we present the results of a retrospective audit comparing the efficacy of the new method against the conventional fixation protocol.

Methods:An equal number of postmortem brains were selected randomly from the year 1998 (following the usual fixation protocol), and from the year 2001 (following the new method). A three tier scoring system was devised to assess section and staining quality, and a single observer scored all the cases.

Results:No statistical difference was noted in the quality of sections prepared by rapid fixation those by conventional fixation. Furthermore, the rapid method was more frequently adequate for diagnosis (considering scores of 2 and 3 together) than the conventional method.

Conclusion:Rapid fixation offers a viable alternative for detailed examination of brains at necropsy, without necessarily prolonging the retention of the organ.
Ethical and legal issues in research involving human subjects: do you want a piece of me?
Authors: Kapp M B
Published: March 2006

The conduct of biomedical research involving the participation of human beings implicates a variety of ethical concerns pertaining to such values as dignity, bodily integrity, autonomy, and privacy. These ethical concerns have been translated into a complex regulatory apparatus in the USA, containing specific legal provisions concerning such matters as participant safety, informed consent, and confidentiality. A topic of particular interest for pathologists is the handling of human tissue specimens that may be used for present, or stored for future, research purposes. This article examines the ethical and legal ramifications of obtaining and storing tissue samples for research purposes, with special attention to the issues of informed consent and confidentiality.
ON PRIME FANO THREEFOLDS OF GENUS 9
Authors: GRUSON L. , LAYTIMI F. , NAGARAJ D. S.
Published: March 2006

It is shown here that any prime Fano threefold of genus 9 is not exotic, that is, its scheme of lines is reduced at the generic point of every component. This extends a result of Prokhorov who showed that the only exotic Fano 3-fold of genus > 9 is the example of Mukai–Umemura. The problem is reduced to a result, obtained here, about the trisecants of a smooth space curve of genus 3 and degree 7.
HARMONIC TWO-SPHERES IN THE SYMPLECTIC GROUP Sp(n)
Authors: PACHECO RUI
Published: March 2006

We shall exploit the Grassmannian theoretic point of view introduced by Segal in order to study harmonic maps from a two-sphere into the symplectic group Sp(n). By using this methodology, we shall be able to deduce an "uniton factorization" of such maps and an alternative characterization of harmonic two-spheres in the quaternionic projective space ℍPn.
PHYSICAL CONSTANTS AND THE GURZADYAN–XUE FORMULA FOR THE DARK ENERGY
Authors: VERESHCHAGIN G. V.
Published: March 2006

We consider cosmological implications of the formula for the dark energy density derived by Gurzadyan and Xue1,2 which predicts a value fitting the observational one. Cosmological models with varying by time physical constants, namely, speed of light and gravitational constant and/or their combinations, are considered. In one of the models, for example, vacuum energy density induces effective negative curvature, while another one has an unusual asymptotic. This analysis also explicitly rises the issue of the meaning and content of physical units and constants in cosmological context.
THE A-POLYNOMIAL n-TUPLE OF A LINK AND HYPERBOLIC 3-MANIFOLDS WITH NON-INTEGRAL TRACES
Authors: ZHANG XINGRU
Published: March 2006

We define A-polynomial n-tuple for a link of n-components and apply them to construct hyperbolic link manifolds with non-integral traces.
A LOWER BOUND FOR THE NUMBER OF REIDEMEISTER MOVES FOR UNKNOTTING
Authors: HAYASHI CHUICHIRO
Published: March 2006

How many Reidemeister moves do we need for unknotting a given diagram of the trivial knot? The absolute value of the writhe gives a lower bound of the number of Reidemeister I moves. That of a complexity of knot diagram "cowrithe" works for Reidemeister II, III moves.

In Appendix A, we give an example of an infinite sequence of diagrams Dn of the trivial knot with an O(n) number of crossings such that the author expects the number of Reidemeister moves needed for unknotting it to be O(n2). However, writhe and cowrithe do not prove this.
THE ÅRHUS INTEGRAL AND THE μ-INVARIANTS
Authors: MOFFATT IAIN
Published: March 2006

We relate the tree part of the Århus integral to Milnor's μ-invariants of string-links in homology balls thus generalizing results of Habegger and Masbaum.
PROTEIN THREADING WITH PROFILES AND DISTANCE CONSTRAINTS USING CLIQUE BASED ALGORITHMS
Authors: DUKKA BAHADUR K. C. , TOMITA ETSUJI , SUZUKI JUN'ICHI , HORIMOTO KATSUHISA , AKUTSU TATSUYA
Published: March 2006

With the advent of experimental technologies like chemical cross-linking, it has become possible to obtain distances between specific residues of a newly sequenced protein. These types of experiments usually are less time consuming than X-ray crystallography or NMR. Consequently, it is highly desired to develop a method that incorporates this distance information to improve the performance of protein threading methods. However, protein threading with profiles in which constraints on distances between residues are given is known to be NP-hard. By using the notion of a maximum edge-weight clique finding algorithm, we introduce a more efficient method called FTHREAD for profile threading with distance constraints that is 18 times faster than its predecessor CLIQUETHREAD. Moreover, we also present a novel practical algorithm NTHREAD for profile threading with Non-strict constraints. The overall performance of FTHREAD on a data set shows that although our algorithm uses a simple threading function, our algorithm performs equally well as some of the existing methods. Particularly, when there are some unsatisfied constraints, NTHREAD (Non-strict constraints threading algorithm) performs better than threading with FTHREAD (Strict constraints threading algorithm). We have also analyzed the effects of using a number of distance constraints. This algorithm helps the enhancement of alignment quality between the query sequence and template structure, once the corresponding template structure is determined for the target sequence.
THE USE OF FUNCTIONAL DOMAINS TO IMPROVE TRANSMEMBRANE PROTEIN TOPOLOGY PREDICTION
Authors: XU EMILY W. , KEARNEY PAUL , BROWN DANIEL G.
Published: March 2006

Transmembrane proteins affect vital cellular functions and pathogenesis, and are a focus of drug design. It is difficult to obtain diffraction quality crystals to study transmembrane protein structure. Computational tools for transmembrane protein topology prediction fill in the gap between the abundance of transmembrane proteins and the scarcity of known membrane protein structures. Their prediction accuracy is still inadequate: TMHMM, the current state-of-the-art method, has less than 52% accuracy in topology prediction on one set of transmembrane proteins of known topology. Based on the observation that there are functional domains that occur preferentially internal or external to the membrane, we have extended the model of TMHMM to incorporate functional domains, using a probabilistic approach originally developed for computational gene finding. Our extension is better than TMHMM in predicting the topology of transmembrane proteins. As prediction of functional domain improves, our system's prediction accuracy will likely improve as well.
HIGH TORSIONAL ENERGY DISULFIDES: RELATIONSHIP BETWEEN CROSS-STRAND DISULFIDES AND RIGHT-HANDED STAPLES
Authors: HAWORTH NAOMI L. , FENG LINA L. , WOUTERS MERRIDEE A.
Published: March 2006

Redox-active disulfides are capable of being oxidized and reduced under physiological conditions. The enzymatic role of redox-active disulfides in thiol-disulfide reductases is well-known, but redox-active disulfides are also present in non-enzymatic protein structures where they may act as switches of protein function. Here, we examine disulfides linking adjacent β-strands (cross-strand disulfides), which have been reported to be redox-active. Our previous work has established that these cross-strand disulfides have high torsional energies, a quantity likely to be related to the ease with which the disulfide is reduced. We examine the relationship between conformations of disulfides and their location in protein secondary structures. By identifying the overlap between cross-strand disulfides and various conformations, we wish to address whether the high torsional energy of a cross-strand disulfide is sufficient to confer redox activity or whether other factors, such as the presence of the cross-strand disulfide in a strained β-sheet, are required.
Mild Cognitive Impairment and Dementia
Authors: Albert Marilyn S. , Blacker Deborah
Published: March 2006

Mild cognitive impairment (MCI) is a clinical syndrome thought to represent the transition between normal function and dementia. This review describes data that support the existence of such a transitional phase, outlines the heterogeneity of MCI and how that has influenced the evolving concept of MCI, and discusses the impact of heterogeneity on recent MCI clinical trials.
Genomic imprinting is a barrier to parthenogenesis in mammals
Authors: Kono T.
Published: March 2006

Only mammals have relinquished parthenogenesis as a means of producing descendants. Bi-parental reproduction is necessary due to parent-specific epigenetic modification of the genome during gametogenesis, which leads to non-equivalent expression of imprinted genes from the maternal and paternal alleles. However, a series of our work showed that alteration of maternal imprinting by oocyte reconstruction using non-growing oocytes, together with deletion of the H19 gene provide appropriate expression of imprinted genes from the maternal genome. The resulting ng (non-growing)/fg (fully-grown) parthenogenic embryos were developed to term. Here, we discuss how the parthenogenetic embryos survived as normal individuals.
Intragenomic politics
Authors: Haig D.
Published: March 2006

The mammalian genome contains multiple genetic factions with distinct interests in the outcomes of interactions among kin. In the context of an offspring’s relations with its mother, these factions are proposed to align into two ‘parties’, one favoring increased demand by offspring and the other favoring reduced demand. A possible alignment has inhibitors of demand located on the X chromosome and enhancers of demand located on autosomes, because X-linked loci are maternally derived two-thirds of the time by contrast to autosomal loci which are maternally derived half of the time.
Evolution of the vertebrate DNMT3 gene family: a possible link between existence of DNMT3L and genomic imprinting
Authors: Yokomine T. , Hata K. , Tsudzuki M. , Sasaki H.
Published: March 2006

DNA methylation plays an essential role in genomic imprinting observed in eutherian mammals and marsupials. In mouse, one of the two de novo DNA methyltransferases, Dnmt3a, and a related protein, Dnmt3L have been shown to be essential for imprint establishment in the parental germline. To gain insights into the evolution of imprinting mechanisms, we have identified and characterized the DNMT3 family genes in other vertebrate species. We cloned cDNAs for chicken DNMT3A and DNMT3B, whose putative protein products shared 81.5% and 48.6% amino acid sequence identity with their mouse orthologues. Using computer-assisted database searches, we also identified DNMT3A and DNMT3B orthologues in fish (fugu and zebrafish) and marsupials (opossum). We found that, while opossums had an orthologue for DNMT3L, chickens and fish did not have this gene. Thus, unlike the other DNMT3 members, DNMT3L was restricted to the species in which imprinting occurs. The acquisition of DNMT3L by a common ancestor of eutherians and marsupials might have been closely related to the evolution of imprinting.
Genome-wide survey of imprinted genes
Authors: Maeda N. , Hayashizaki Y.
Published: March 2006

The developmental failure of mammalian parthenogenote has been a mystery for a long time and posed a question as to why bi-parental reproduction is necessary for development to term. In the 1980s, it was proven that this failure was not due to the genetic information itself, but to epigenetic modification of genomic DNA. In the following decade, several studies successfully identified imprinted genes which were differentially expressed in a parent-of-origin-specific manner, and it was shown that the differential expression depended on the pattern of DNA methylation. These facts prompted development of genome-wide systematic screening methods based on DNA methylation and differential gene expression to identify imprinted genes. Recently computational approaches and microarray technology have been introduced to identify imprinted genes/loci, contributing to the expansion of our knowledge. However, it has been shown that the gene silencing derived from genomic imprinting is accomplished by several mechanisms in addition to direct DNA methylation, indicating that novel approaches are further required for comprehensive understanding of genomic imprinting. To unveil the mechanism of developmental failure in mammalian parthenogenote, systematic screenings for imprinted genes/loci have been developed. In this review, we describe genomic imprinting focusing on the history of genome-wide screening.
Lessons from comparative analysis of species-specific imprinted genes
Authors: Okamura K. , Ito T.
Published: March 2006

Genomic imprinting is generally believed to be conserved in all mammals except for egg-laying monotremes, suggesting that it is closely related to placental and fetal growth. As expected, the imprinting status of most imprinted genes is conserved between mouse and human, and some are imprinted even in marsupials. On the other hand, a small number of genes were reported to exhibit species-specific imprinting that is not necessarily accounted for by either the placenta or conflict hypotheses. Since mouse and human represent a single, phylogenetically restricted clade in the mammalian class, a much broader comparison including mammals diverged earlier than rodents is necessary to fully understand the species-specificity and variation in evolution of genomic imprinting. Indeed, comparative analysis of a species-specific imprinted gene Impact using a broader range of mammals led us to propose an alternative dosage control hypothesis for the evolution of genomic imprinting.
Imprinting the Gnas locus
Authors: Plagge A. , Kelsey G.
Published: March 2006

Gnas is an enigmatic and rather complex imprinted gene locus. A single transcription unit encodes three, and possibly more, distinct proteins. These are determined by overlapping transcripts from alternative promoters with different patterns of imprinting. The canonical Gnas transcript codes for Gsα, a highly conserved signalling protein and an essential intermediate in growth, differentiation and homeostatic pathways. Monoallelic expression of Gnas is highly tissue-restricted. The alternative transcripts encode XLαs, an unusual variant of Gsα, and the chromogranin-like protein Nesp55. These transcripts are expressed specifically from the paternal and maternal chromosomes, respectively. Their existence in the Gnas locus might imply functional connections amongst them or with Gsα. In this review, we consider how imprinting of Gnas was discovered, the phenotypic consequences of mutations in each of the gene products, both in the mouse and human, and provide some conjectures to explain why this elaborate imprinted locus has evolved in this manner in mammals.
The H19 gene: regulation and function of a non-coding RNA
Authors: Gabory A. , Ripoche M.-A. , Yoshimizu T. , Dandolo L.
Published: March 2006

The H19 gene encodes a 2.3-kb non-coding mRNA which is strongly expressed during embryogenesis. This gene belongs to an imprinted cluster, conserved on mouse chromosome 7 and human chromosome 11p15. H19 is maternally expressed and the neighbouring Igf2 gene is transcribed from the paternal allele. These two genes are co-expressed in endoderm- and mesoderm-derived tissues during embryonic development, which suggests a common mechanism of regulation. The regulatory elements (imprinted con- trol region, CTCF insulation, different enhancer sequences, promoters of the two genes, matrix attachment regions) confer a differential chromatin architecture to the two parental alleles leading to reciprocal expression. The role of the H19 gene is unclear but different aspects have been proposed. H19 influences growth by way of a cis control on Igf2 expression. Although H19–/– mice are viable, a role for this gene during development has been suggested by viable H19–/– parthenogenetic mice. Finally it has been described as a putative tumour suppressor gene. H19 has been studied by numerous laboratories over the last fifteen years, nevertheless the function of this non-coding RNA remains to be elucidated.
Mutagenesis in mice of nuclear hormone receptor binding sites in the Igf2/H19 imprinting control region
Authors: Szabó P.E. , Han L. , Hyo-Jung J. , Mann J.R.
Published: March 2006

The H19/Igf2 imprinting control region (ICR) is a DNA methylation-dependent chromatin insulator in somatic cells. The hypomethylated maternally inherited ICR binds the insulator protein CTCF at four sites, and blocks activity of the proximal Igf2 promoter by insulating it from the shared distal enhancers. The hypermethylated paternally inherited ICR lacks CTCF binding and insulator activity, but induces methylation-silencing of the paternal H19 promoter. The paternal-specific methylation of the ICR is established in the male germ cells, while the ICR emerges from the female germ line in an unmethylated form. Despite several attempts to find cis-regulatory elements, it is still unknown what determines these male and female germ cell-specific epigenetic modifications. We recently proposed that five in vivo footprints spanning fifteen half nuclear hormone receptor (NHR) binding sites within the ICR might be involved, and here we report on the effects of mutagenizing all of these half sites in mice. No effect was obtained – in the female and male germ lines the mutant ICR remained hypomethylated and hypermethylated, respectively. The ICR imprinting mechanism remains undefined.
Imprinted genes and their role in human fetal growth
Authors: Abu-Amero S. , Monk D. , Apostolidou S. , Stanier P. , Moore G.
Published: March 2006

Growth is defined as the progressive increase in size and is listed as one of the eight main characteristics of life. In human gestation the most rapid growth phase is from 16 to 32 weeks when first there is both cell number and size increase and then from 32 weeks onwards there is continued size increase (Pollack and Divon, 1992). The mechanism of growth in utero is of fundamental interest to clinicians and scientists because of its implications for neonatal health. Growth is multifactorial in origin with both genetics and environment contributing equally large parts. Despite this complexity analysis of the candidate genes involved is possible using simple tissue biopsies at the relevant stages of development. Of particular interest in understanding fetal growth is the analysis of a group of genes that show a parent-of-origin effect known as genomic imprinting. Imprinted genes are not only found in eutherian (placental) and metatherian (marsupial) mammals but surprisingly also in plants. Nevertheless, their evolution in mammals appears to be linked primarily to placentation. It is thought to result from a potential conflict between the parents in terms of the drive to successfully propagate their own separate genes and the mother’s added drive for her survival through the pregnancy to reproduce again. This means that the mother wants to restrict fetal growth and the father to enhance it.
Imprinted genes in placental growth and obstetric disorders
Authors: Tycko B.
Published: March 2006

Genomic imprinting has a special role in placental biology. Imprinted genes are often strongly expressed in the placenta, and the allelic expression bias due to imprinting is sometimes stronger in this extraembryonic organ than in the embryo and adult. Mutations, epimutations, and uniparental disomies affecting imprinted loci cause placental stunting or overgrowth in mice and humans, and placental neoplasms (complete hydatidiform moles) are androgenetic. Whether imprinted genes might also play a role in the more common medical conditions that affect the placenta, including preeclampsia and intrauterine growth restriction (IUGR), is an important question that is now receiving some attention. Here we review this area and describe recent data indicating altered expression of imprinted genes in the placental response to maternal vascular underperfusion associated with IUGR.
Imprinting defects on human chromosome 15
Authors: Horsthemke B. , Buiting K.
Published: March 2006

The Prader-Willi syndrome (PWS) and Angelman syndrome (AS) are two distinct neurogenetic diseases that are caused by the loss of function of imprinted genes on the proximal long arm of human chromosome 15. In a few percent of patients with PWS and AS, the disease is due to aberrant imprinting and gene silencing. In patients with PWS and an imprinting defect, the paternal chromosome carries a maternal imprint. In patients with AS and an imprinting defect, the maternal chromosome carries a paternal imprint. Imprinting defects offer a unique opportunity to identify some of the factors and mechanisms involved in imprint erasure, resetting and maintenance. In approximately 10% of cases the imprinting defects are caused by a microdeletion affecting the 5′ end of the SNURF-SNRPN locus. These deletions define the 15q imprinting center (IC), which regulates imprinting in the whole domain. These findings have been confirmed and extended in knock-out and transgenic mice. In the majority of patients with an imprinting defect, the incorrect imprint has arisen without a DNA sequence change, possibly as the result of stochastic errors of the imprinting process or the effect of exogenous factors.
Women Have Higher Left Ventricular Ejection Fractions Than Men Independent of Differences in Left Ventricular Volume
Authors: Chung Anne K. , Das Sandeep R. , Leonard David , Peshock Ronald M. , Kazi Farhana , Abdullah Shuaib M. , Canham Russell M. , Levine Benjamin D. , Drazner Mark H.
Published: March 2006

Background—

Although gender-specific criteria are common for defining cardiac traits such as left ventricular hypertrophy, left ventricular ejection fraction (LVEF) thresholds widely used in clinical practice have traditionally been the same for women and men, perhaps because it remains uncertain whether there is a systematic difference in LVEF between genders.

Methods and Results—

Using cardiac magnetic resonance imaging in a probability-based sample of Dallas County residents aged 30 to 65 years (1435 women and 1183 men), we compared LVEF in women and men. The association of gender with stroke volume independent of end-diastolic volume (EDV) or other potential confounders was assessed by multivariable analysis. Gender-specific thresholds for a low LVEF were defined at the 2.5th percentile in women and men from a healthy reference subpopulation. The median (25th, 75th percentile) LVEF was higher in women than in men (75% [70%, 79%] in women versus 70% [65%, 75%] in men,
P
<0.001). Left ventricular EDV and end-systolic volume indexed to body surface area were smaller in women than in men (
P
<0.001 for both). Gender remained significantly associated with stroke volume, independent of EDV and other potential confounders in multivariable analysis. A low LVEF was defined as below 61% in women and below 55% in men.

Conclusions—

Women have a higher LVEF than men in the general population, secondary to a higher stroke volume for a given EDV independent of known potential confounders.
Pattern Flows: Hybrid Accretive Processes Informing Identity Construction
Authors: Seaman Bill
Published: March 2006

How is it that persons, places, things, and language elements come to have unique identities? In particular, how do notions of the hybrid play into our understanding of identities? In what way does the computer change the way we communicate about and come to understand these entities? How does embodied experience play a part in identity forming? The paper explores concepts surrounding spatial/temporal patterning as a generator of emergent meaning. Identity is here considered as linked to an embodied recombinant gathering of abbreviations of experiental pattern residues. It is a collage-like construction arising out of fragments of associated pattern flows. In this sense identity is always the result of a construction process built of pattern reinforcements and pattern updating. Identity as a product of human understanding draws on an ongoing constructive assembly of processes inherent to meaning-becoming. In this definition there is no such thing as an invariant pattern - only accretive patterns that are similar but different. Here understandings are constantly recombined to address the nature of emergent context. Thus, understanding is always an accretive, hybridising process. An expanded linguistics arises as an ability to fragment, combine and recombine particular pattern instances in the service of evocation and exchange - articulation through intra-action. I am proposing a non-logocentric (or non-word-centred) linguistics, with which we can bring a series of sensual instantiations and media forms into language study, not mimicking the functional nature of words, but exhibiting their own patterned qualities. The complexity that arises out of this re-interpretation is profound yet it is none-the-less necessary to clearly understand an accretive, non-dualistic approach to meaning production.
New Media Arts Hybridity: The Vases (Dis)communicants Between Art, Affective Science and AR Technology
Authors: Ross Christine
Published: March 2006

Following Annie Coombes’s and Avtar Brah’s (authors of Hybridity and its Discontents: Politics, Science, Culture, 2000) request that we not merely apply but in fact historicise hybridity, and arguing that the art and science explorations of new media art have produced some of the strongest new media hybridities to date, the author focuses on one of the important fields of investigation currently linking media art, science and technology: augmented reality or what should be called augmented perception of time and space. This aesthetic field of investigation has led to a reassessment of representation, one that is not without (1) sharing some of the fundamental concerns of current neuroscientific investigation of mental processes and (2) questioning the image/real continuum principle at the core of recent augmented reality technology research. The article examines media artist Bill Viola’s The Passions series (2000-2001) to contend that new media’s original contribution to the practice of hybridity lies in the interaction that it both articulates and encourages with affective sciences, an interaction that redefines representation as an approximation, a facilitator - a projection screen for complex mental processes.
Changes in Non-fibrous Material Content of Cotton during Yarn Processing
Authors: Brushwood Donald E.
Published: March 2006

Two Fibermax varieties of cotton grown in a single season and common to three domestic areas were blended into lots, evaluated for physical properties, and subsequently spun on ring, open-end, and Vortex systems. Samplings of carding sliver, finish drawing, and yarns selected at different processing stages were tested for fiber noncellulosic content. Variations in fiber micronaire, which were highly related to growing location, influenced initial concentrations of total alcohol surface nonfibrous and wax extractables. In processing, no changes were seen in the fiber plant sugar or surface wax content. Alcohol extractables decreased in the opening and carding and yarn spinning stages Concentrations of the residual light metals potassium, calcium, magnesium, and sodium were reduced on the fiber primarily in the opening and carding stage of yarn production The magnitude of reduction in alcohol surface extractables and light metal content during processing was found to be highly related to fiber micronaire.