bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Testosterone Supplementation on Skeletal Muscle Fiber Hypertrophy and Satellite Cells in Community-Dwelling Older Men
Authors: Sinha-Hikim Indrani , Cornford Marcia , Gaytan Hilda , Lee Martin L. , Bhasin Shalender 
Published: May 2006

Abstract
Objective: In this study, we determined the effects of graded doses of testosterone on muscle fiber cross-sectional area (CSA) and satellite cell number and replication in older men.
Participants: Healthy men, 60–75 yr old, received a long-acting GnRH agonist to suppress endogenous testosterone production and 25, 50, 125, 300, or 600 mg testosterone enanthate im weekly for 20 wk.
Methods: Immunohistochemistry, light and confocal microscopy, and electron microscopy were used to perform fiber typing and quantitate myonuclear and satellite cell number in vastus lateralis biopsies, obtained before and after 20 wk of treatment.
Results: Testosterone administration in older men was associated with dose-dependent increases in CSA of both types I and II fibers. Satellite cell number increased dose dependently at the three highest doses (3% at baseline vs. 6.2, 9.2, and 13.0% at 125, 300, and 600 mg doses, P &lt; 0.05). Testosterone administration was associated with an increase in the number of proliferating cell nuclear antigen+ satellite cells (1.8% at baseline vs. 3.9, 7.5, and 13% at 125, 300, and 600 mg doses, P &lt; 0.005). The expression of activated Notch, examined only in the 300-mg group (baseline, 2.3 vs. 9.0% after treatment, P &lt; 0.005), increased in satellite cells after testosterone treatment. The expression of myogenin (baseline, 6.2 vs. 20.7% after treatment, P &lt; 0.005), examined only in the 300-mg group, increased significantly in muscle fiber nuclei after testosterone treatment, but Numb expression did not change.
Conclusions: Older men respond to graded doses of testosterone with a dose-dependent increase in muscle fiber CSA and satellite cell number. Testosterone-induced skeletal muscle hypertrophy in older men is associated with increased satellite cell replication and activation.
Monosomy for the X-Chromosome Is Associated with an Atherogenic Lipid Profile
Authors: Van Phillip L. , Bakalov Vladimir K. , Bondy Carolyn A. 
Published: May 2006

AbstractContext and Objective: Men typically have a more atherogenic lipid profile than women characterized by higher low-density lipoprotein (LDL) cholesterol and triglyceride levels and reduced lipid particle size, contributing to a greater risk for coronary disease. To determine whether X-chromosomal gene dosage affects lipid metabolism independent of sex steroid effects, we compared lipid profiles in age- and body mass-matched young women with ovarian failure, differing only in X-chromosome dosage.Design, Setting, and Patients: Women with premature ovarian failure associated with monosomy X or Turner syndrome (TS, n = 118) were compared with women with 46,XX premature ovarian failure (n = 51) in an in-patient clinical research center unit at the National Institutes of Health. These women were normally on estrogen replacement treatment but discontinued the estrogen 2 wk before study.Major Outcomes: Fasting lipid levels and nuclear magnetic resonance lipid particle profiles in the two study groups were the major outcomes.Results: Average age and body mass were similar in the two groups of women, but LDL cholesterol (P = 0.001) and triglyceride levels (P = 0.0005) were higher in the TS group. Also among women with TS, average LDL particle size was reduced (P &lt; 0.0001) and LDL particle concentration increased, with a 2-fold increase in the smallest particle categories (P &lt; 0.0001). Whereas total high-density lipoprotein cholesterol levels were similar, high-density lipoprotein particle size was significantly smaller in women with TS, compared with women with premature ovarian failure (P &lt; 0.0001).Conclusions: Women with 45,X with ovarian failure exhibit a distinctly more atherogenic lipid profile than 46,XX women with ovarian failure, suggesting that the second X-chromosome contributes to a more salutary lipid profile in normal women, independent of sex steroid effects.
Is your evidence robust enough? Questions for policy makers and practitioners
Authors: Shaxson Louise 
Published: May 2006

English
This article examines the reasons we need evidence for policy, discusses where evidence is needed in the policy-making process, and the nature of the evidence base for strategy and policy. Working relationships between policy makers and their advisers are key: as policy makers come from a variety of backgrounds, developing a common language helps set discussions about the robustness of the evidence base on a sound footing. The article identifies five components of robustness, proposes a series of questions that could be used to address them and discusses the implications for the processes of policy making.
Real algebraic morphisms on 2-dimensional conic bundles
Authors: Mangolte Frédéric 
Published: May 2006

Abstract
Given two nonsingular real algebraic varieties V and W, we consider the problem of deciding whether a smooth map f : V → W can be approximated by regular maps in the space of 𝒞∞ mappings from V to W in the 𝒞∞ topology. Our main result is a complete solution to this problem in case W is the usual 2-dimensional sphere and V is a real algebraic surface of negative Kodaira dimension.
Geodesics in non-positively curved plane tessellations
Authors: Baues Oliver , Peyerimhoff Norbert 
Published: May 2006

Abstract
We introduce a natural combinatorial curvature function on the corners of plane tessellations and relate it to the global metric geometry of their corresponding edge and dual graphs. If the combinatorial curvature in the corners is non-positive then we prove that any geodesic path in such a graph may be extended to infinity. Moreover, if the combinatorial curvature is negative we show that every pair of geodesic segments with the same end points does not enclose any vertices. We apply these results to establish an estimate for the growth of distance balls, Gromov hyperbolicity, and four-colourability of certain classes of plane tessellations.
Representation type of Schur superalgebras
Authors: Hemmer David J , Kujawa Jonathan , Nakano Daniel K 
Published: May 2006

Abstract
Let S(m|n, d) be the Schur superalgebra whose supermodules correspond to the polynomial representations of the supergroup GL(m|n) of degree d. In this paper we determine the representation type of these algebras (that is, we classify the ones which are semisimple, have finite, tame and wild representation type). Moreover, we prove that these algebras are in general not quasi-hereditary and have infinite global dimension.
Embedding groups in locally (soluble-by-finite) simple groups
Authors: Dixon Martyn R , Evans Martin J , Smith Howard 
Published: May 2006

Abstract
The authors investigate the structure of locally (soluble-by-finite) simple groups
Ĝ
and show that such groups are locally residually finite. Sufficient conditions are given for a group G to be embeddable in such a group
Ĝ
and an example of a locally (abelian-by-finite) simple group is constructed.
Fine-Scale Map of Encyclopedia of DNA Elements Regions in the Korean Population
Authors: Yoo Yeon-Kyeong , Ke Xiayi , Hong Sungwoo , Jang Hye-Yoon , Park Kyunghee , Kim Sook , Ahn TaeJin , Lee Yeun-Du , Song Okryeol , Rho Na-Young , Lee Moon Sue , Lee Yeon-Su , Kim Jaeheup , Kim Young J , Yang Jun-Mo , Song Kyuyoung , Kimm Kyuchan , Weir Bruce , Cardon Lon R , Lee Jong-Eun , Hwang Jung-Joo 
Published: May 2006

Abstract
The International HapMap Project aims to generate detailed human genome variation maps by densely genotyping single-nucleotide polymorphisms (SNPs) in CEPH, Chinese, Japanese, and Yoruba samples. This will undoubtedly become an important facility for genetic studies of diseases and complex traits in the four populations. To address how the genetic information contained in such variation maps is transferable to other populations, the Korean government, industries, and academics have launched the Korean HapMap project to genotype high-density Encyclopedia of DNA Elements (ENCODE) regions in 90 Korean individuals. Here we show that the LD pattern, block structure, haplotype diversity, and recombination rate are highly concordant between Korean and the two HapMap Asian samples, particularly Japanese. The availability of information from both Chinese and Japanese samples helps to predict more accurately the possible performance of HapMap markers in Korean disease-gene studies. Tagging SNPs selected from the two HapMap Asian maps, especially the Japanese map, were shown to be very effective for Korean samples. These results demonstrate that the HapMap variation maps are robust in related populations and will serve as an important resource for the studies of the Korean population in particular.
Natural Variation inMAMWithin and Between Populations ofArabidopsis lyrataDetermines Glucosinolate Phenotype
Authors: Heidel Andrew J , Clauss Maria J , Kroymann Juergen , Savolainen Outi , Mitchell-Olds Thomas 
Published: May 2006

AbstractThe genetic variation that underlies the glucosinolate phenotype of Arabidopsis lyrata ssp. petraea was investigated between and within populations. A candidate glucosinolate biosynthetic locus (MAM, containing methylthioalkylmalate synthase genes) was mapped in A. lyrata to a location on linkage group 6 corresponding to the homologous location for MAM in A. thaliana. In A. thaliana MAM is responsible for side chain elongation in aliphatic glucosinolates, and the MAM phenotype can be characterized by the ratios of long- to short-chain glucosinolates. A quantitative trait loci (QTL) analysis of glucosinolate ratios in an A. lyrata interpopulation cross found one QTL at MAM. Additional QTL were identified for total indolic glucosinolates and for the ratio of aliphatic to indolic glucosinolates. MAM was then used as the candidate gene for a within-population cosegregation analysis in a natural A. lyrata population from Germany. Extensive variation in microsatellite markers at MAM was found and this variation cosegregated with the same glucosinolate ratios as in the QTL study. The combined results indicate that both between- and within-population genetic variation in the MAM region determines phenotypic variation in glucosinolate side chains in A. lyrata.
PAPPA2, an Enzyme That Cleaves an Insulin-Like Growth-Factor-Binding Protein, Is a Candidate Gene for a Quantitative Trait Locus Affecting Body Size in Mice
Authors: Christians Julian K , Hoeflich Andreas , Keightley Peter D 
Published: May 2006

AbstractIdentifying genes responsible for quantitative variation remains a major challenge. We previously identified a quantitative trait locus (QTL) affecting body size that segregated between two inbred strains of mice. By fine mapping, we have refined the location of this QTL to a genomic region containing only four protein-coding genes. One of these genes, PAPPA2, is a strong candidate because it codes for an enzyme that cleaves insulin-like growth-factor-binding protein 5 (IGFBP-5), an important stimulator of bone formation. Among littermates that segregate only for the four-gene region, we show that the QTL has a significant effect on the circulating levels of IGFBP-5 and IGFBP-3 (the latter subject to limited degradation by PAPPA2), but not on levels of IGFBP-2 and IGFBP-4, which are not cleaved by PAPPA2. There are 14 nonsynonymous SNPs among QTL alleles, which may affect the activity of the translated protein. The refinement of the target region to four genes and the finding that the QTL affects IGFBP-5 levels suggest that PAPPA2 may be involved with normal postnatal growth. Our mapping results also illustrate the potentially fractal nature of QTL: as we mapped our QTL with increasing resolution, what appeared to be a single QTL resolved into three closely linked QTL (previous work), and then one of these was further dissected into two in this study.
Discovery and Mapping of Wheat Ph1 Suppressors
Authors: Dvorak J , Deal K R , Luo M-C 
Published: May 2006

Abstract
Pairing between wheat (Triticum turgidum and T. aestivum) homeologous chromosomes is prevented by the expression of the Ph1 locus on the long arm of chromosome 5B. The genome of Aegilops speltoides suppresses Ph1 expression in wheat × Ae. speltoides hybrids. Suppressors with major effects were mapped as Mendelian loci on the long arms of Ae. speltoides chromosomes 3S and 7S. The chromosome 3S locus was designated Su1-Ph1 and the chromosome 7S locus was designated Su2-Ph1. A QTL with a minor effect was mapped on the short arm of chromosome 5S and was designated QPh.ucd-5S. The expression of Su1-Ph1 and Su2-Ph1 increased homeologous chromosome pairing in T. aestivum × Ae. speltoides hybrids by 8.4 and 5.8 chiasmata/cell, respectively. Su1-Ph1 was completely epistatic to Su2-Ph1, and the two genes acting together increased homeologous chromosome pairing in T. aestivum × Ae. speltoides hybrids to the same level as Su1-Ph1 acting alone. QPh.ucd-5S expression increased homeologous chromosome pairing by 1.6 chiasmata/cell in T. aestivum × Ae. speltoides hybrids and was additive to the expression of Su2-Ph1. It is hypothesized that the products of Su1-Ph1 and Su2-Ph1 affect pairing between homeologous chromosomes by regulating the expression of Ph1 but the product of QPh.ucd-5S may primarily regulate recombination between homologous chromosomes.
Natural History of Transposition in the Green Alga Chlamydomonas reinhardtii: Use of the AMT4 Locus as an Experimental System
Authors: Kim Kwang-Seo , Kustu Sydney , Inwood William 
Published: May 2006

Abstract
The AMT4 locus of the green alga Chlamydomonas reinhardtii, which we mapped to the long arm of chromosome 8, provides a good experimental system for the study of transposition. Most mutations that confer resistance to the toxic ammonium analog methylammonium are in AMT4 and a high proportion of spontaneous mutations are caused by transposon-related events. Among the 15 such events that we have characterized at the molecular level, 9 were associated with insertions of the retrotransposon TOC1, 2 with a small Gulliver-related transposon, and 1 with the Tcr1 transposon. We found that Tcr1 is apparently a foldback transposon with terminal inverted repeats that are much longer and more complex than previously realized. A duplication of Tcr1 yielded a configuration thought to be important for chromosomal evolution. Other mutations in AMT4 were caused by two mobile elements that have not been described before. The sequence of one, which we propose to call the Bill element, indicates that it probably transposes by way of a DNA intermediate and requires functions that it does not encode. The sequence of the other and bioinformatic analysis indicates that it derives from a miniature retrotransposon or TRIM, which we propose to call MRC1 (miniature retrotransposon of Chlamydomonas).
Developmental Modulation of Nonhomologous End Joining in Caenorhabditis elegans
Authors: Clejan Iuval , Boerckel Julie , Ahmed Shawn 
Published: May 2006

Abstract
Homologous recombination and nonhomologous end joining (NHEJ) are important DNA double-strand break repair pathways in many organisms. C. elegans strains harboring mutations in the cku-70, cku-80, or lig-4 NHEJ genes displayed multiple developmental abnormalities in response to radiation-induced DNA damage in noncycling somatic cells. These phenotypes did not result from S-phase, DNA damage, or mitotic checkpoints, apoptosis, or stress response pathways that regulate dauer formation. However, an additional defect in him-10, a kinetochore component, synergized with NHEJ mutations for the radiation-induced developmental phenotypes, suggesting that they may be triggered by mis-segregation of chromosome fragments. Although NHEJ was an important DNA repair pathway for noncycling somatic cells in C. elegans, homologous recombination was used to repair radiation-induced DNA damage in cycling somatic cells and in germ cells at all times. Noncycling germ cells that depended on homologous recombination underwent cell cycle arrest in G2, whereas noncycling somatic cells that depended on NHEJ arrested in G1, suggesting that cell cycle phase may modulate DNA repair during development. We conclude that error-prone NHEJ plays little or no role in DNA repair in C. elegans germ cells, possibly ensuring homology-based double-strand break repair and transmission of a stable genome from one generation to the next.
Relevance of Sunscreen Application Method, Visible Light and Sunlight Intensity to Free‐radical Protection: A Study of ex vivo Human Skin
Authors: Haywood Rachel 
Published: May 2006

ABSTRACTWith the continued rise in skin cancers worldwide there is a need for effective skin protection against sunlight damage. It was shown previously that sunscreens, which claimed UVA protection (SPF 20+), provided limited protection against UV‐induced ascorbate radicals in human skin. Here the results of an electron spin resonance (ESR) investigation to irradiate ex vivo human skin with solar‐simulated light are reported. The ascorbate radical signal in the majority of skin samples was directly proportional to the irradiance over relevant sunlight intensities (0.9–2.9 mW cm−2). Radical production (substratum‐corneum) by UV (wavelengths <400 nm) and visible components (>400 nm) was ∼67% and 33% respectively. Ascorbate radicals were in steady state concentration at low irradiance (∼1 mW cm−2 equivalent to UK sunlight), but at higher irradiance (∼3 mW cm−2) decreased with time, suggesting ascorbate depletion. Radical protection by a four star‐rated sunscreen (with UVA protection) was optimal when applied as a thin film (40–60% at 2 mg cm−2) but less so when rubbed into the skin (37% at 4 mg cm−2 and no significant protection at 2 mg cm−2), possibly due to cream filling crevices, which reduced film thickness. This study validates ESR determinations of the ascorbate radical for quantitative protection measurements. Visible light contribution to radical production, and loss of protection when sunscreen is rubbed into skin, has implications for sunscreen design and use for the prevention of free‐radical damage.
Towards a Functional Dissection of Thioredoxin Networks in Plant Cells†
Authors: Hisabori Toru , Motohashi Ken , Hosoya‐Matsuda Naomi , Ueoka‐Nakanishi Hanayo , Romano Patrick G. N. 
Published: May 2006

AbstractThioredoxins are a ubiquitous family of redox equivalent mediators, long considered to possess a limited number of target enzymes. Recent progress in proteomic research has allowed the identification of a wide variety of candidate proteins with which this small protein may interact in vivo. Moreover, the activity of thioredoxin itself has been recently found to be subject to regulation by posttranslational modifications, adding an additional level of complexity to the function of this intriguing enzyme family. The current review charts the technical progress made in the continuing discovery of the numerous and diverse roles played by these proteins in the regulation of redox networks in plant cells.
Molecular Mechanisms Characterizing Cone Photoresponses†
Authors: Tachibanaki Shuji , Shimauchi‐Matsukawa Yoshie , Arinobu Daisuke , Kawamura Satoru 
Published: May 2006

AbstractIn the vertebrate retina, rods mediate twilight vision and cones mediate daylight vision. Their photoresponse characteristics are different. The light‐sensitivity of a cone is 102–103 times lower than that of a rod. In addition, the photoresponse time course is much faster in cones. The mechanism characterizing cone photoresponses has not been known mainly because of the difficulty in isolating cones in large quantities to perform biochemistry. Recently, we developed a method to purify cones from carp retina using a density gradient, which made it possible to analyze the differences in the molecular mechanism of phototransduction between rods and cones. The results showed that signal amplification in cones is less effective, which explains the lower light‐sensitivity of cones. The results also showed that visual pigment phosphorylation, a quenching mechanism of light‐activated visual pigment, is much more rapid in cones than in rods. The rapid phosphorylation in cones is attributed to a very high total kinase activity in cones. Because of this high activity, cone pigment is readily phosphorylated even at very high bleaching levels, which probably explains why cone photoresponses recover quickly. Based on these findings, the molecular mechanisms of the differences in the photoresponse characteristics between rods and cones are outlined.
Comparative study of alloxan effects in copper-loaded and iron-loaded rats: lipid peroxidation, protein oxidation, proteasome and antioxidant enzyme activities
Authors: Alexandrova Albena , Georgieva Almira , Petrov Lubomir , Tsvetanova Elina , Kirkova Margarita 
Published: May 2006

Abstract
The in-vivo effects of alloxan on protein oxidation and lipid peroxidation, as well as on proteasome and antioxidant enzyme activities in liver and kidney of copper-loaded and iron-loaded rats, were studied. In control animals, a single alloxan dose (120 mg/kg, i.p.) increased blood-glucose concentration at the 24th hr and 48th hr and, especially, on the 5th day. For these periods of alloxan action, no changes in lipid peroxidation and antioxidant enzyme activities were found; only a slight increase of carbonyl content and strong increase of trypsin-like proteasome activity in rat liver on the 5th day was observed. Five days after alloxan injection, the blood-glucose concentration in iron-pretreated rats was similar to that of the controls. However, it was significantly lower in copper-pretreated animals; hence, insulin-mimetic action of copper might be suggested. The lower proteasome activity, measured in liver of copper-pretreated diabetic rats is probably due to a potential copper-chelating ability of alloxan. The present results showed that the action of alloxan was different in copper-and iron-pretreated rats. Analogous studies, using pretreatment with other metals, would contribute to a further elucidation of the role of different metals in diabetes development, especially in regions with environmental metal contamination.
Targeting of solid tumors and blood malignancies by antibody-based therapies — EGFR-pathway as an example
Authors: Krzemieniecki Krzysztof , Szpyt Elzbieta , Rashedi Iran , Gawron Katarzyna , Los Marek 
Published: May 2006

Abstract
A well-coordinated interaction between extracellular signals and intracellular response forms the basis of life within multicellular organisms, with growth factors playing a crucial role in these interactions. Discoveries in recent years have shown that components of the Epidermal Growth Factor (EGF) signaling system have frequently been used by cancer cells to autonomously provide survival and proliferation signals. The main focus of this review is the ErbB epidermal growth factor receptor (EGFR) family of receptor tyrosine kinases including ErbB1/EGFR, ErbB2/HER2/neu, ErbB3/HER3, and ErbB4/HER4 as therapeutic targets. Since the ErbB receptor family regulates cell proliferation through the Ras-mitogen-activated protein kinase (RAS/MAPK) pathway, and cell survival and transformation through the phosphatidylinositol 3-kinase (PI3K/AKT) pathway, pharmacological targeting of these pathways is also discussed. We will also address the clinical studies that have been conducted to evaluate antibody-based therapies mostly on solid tumors and hematologic malignancies.