bluuebunny/crossref_metadata_2025 huggingface dataset:
Sex-Biased Lethality or Transmission of Defective Transcription Machinery in Arabidopsis
Authors: Onodera Yasuyuki , Nakagawa Kosuke , Haag Jeremy R , Pikaard Diane , Mikami Tetsuo , Ream Thomas , Ito Yusuke , Pikaard Craig S
Published: August 2008

Unlike animals, whose gametes are direct products of meiosis, plant meiotic products undergo additional rounds of mitosis, developing into multicellular haploid gametophytes that produce egg or sperm cells. The complex development of gametophytes requires extensive expression of the genome, with DNA-dependent RNA polymerases I, II, and III being the key enzymes for nuclear gene expression. We show that loss-of-function mutations in genes encoding key subunits of RNA polymerases I, II, or III are not transmitted maternally due to the failure of female megaspores to complete the three rounds of mitosis required for the development of mature gametophytes. However, male microspores bearing defective polymerase alleles develop into mature gametophytes (pollen) that germinate, grow pollen tubes, fertilize wild-type female gametophytes, and transmit the mutant genes to the next generation at moderate frequency. These results indicate that female gametophytes are autonomous with regard to gene expression, relying on transcription machinery encoded by their haploid nuclei. By contrast, male gametophytes make extensive use of transcription machinery that is synthesized by the diploid parent plant (sporophyte) and persists in mature pollen. As a result, the expected stringent selection against nonfunctional essential genes in the haploid state occurs in the female lineage but is relaxed in the male lineage.
The Dominant Cold-SensitiveOut-ColdMutants ofDrosophila melanogasterHave Novel Missense Mutations in the Voltage-Gated Sodium Channel Geneparalytic
Authors: Lindsay Helen A , Baines Richard , ffrench-Constant Richard , Lilley Kathryn , Jacobs Howard T , O'Dell Kevin M C
Published: August 2008

Here we report the molecular characterization of Out-cold (Ocd) mutants of Drosophila melanogaster, which produce a dominant, X-linked, cold-sensitive paralytic phenotype. From its initial 1.5-Mb cytological location within 13F1-16A2, P-element and SNP mapping reduced the Ocd critical region to <100 kb and to six candidate genes: hangover, CG9947, CG4420, eIF2a, Rbp2, and paralytic (para). Complementation testing with para null mutations strongly suggests Ocd and para are allelic, as does gene rescue of Ocd semilethality with a wild-type para transgene. Pesticide resistance and electrophysiological phenotypes of Ocd mutants support this conclusion. The para gene encodes a voltage-gated sodium channel. Sequencing the Ocd lines revealed mutations within highly conserved regions of the para coding sequence, in the transmembrane segment S6 of domain III (I1545M and T1551I), and in the linker between domains III and IV (G1571R), the location of the channel inactivation gate. The G1571R mutation is of particular interest as mutations of the orthologous residue (G1306) in the human skeletal muscle sodium channel gene SCN4A are associated with cases of periodic paralysis and myotonia, including the human cold-sensitive disorder paramyotonia congenita. The mechanisms by which sodium channel mutations cause cold sensitivity are not well understood. Therefore, in the absence of suitable vertebrate models, Ocd provides a system in which genetic, molecular, physiological, and behavioral tools can be exploited to determine mechanisms underlying sodium channel periodic paralyses.
Tissue-Specific Defects Are Caused by Loss of the Drosophila MAN1 LEM Domain Protein
Authors: Pinto Belinda S , Wilmington Shameika R , Hornick Emma E L , Wallrath Lori L , Geyer Pamela K
Published: August 2008

The nuclear lamina represents a protein network required for nuclear structure and function. One family of lamina proteins is defined by an ∼40-aa LAP2, Emerin, and MAN1 (LEM) domain (LEM-D) that binds the nonspecific DNA-binding protein, barrier-to-autointegration factor (BAF). Through interactions with BAF, LEM-D proteins serve as a bridge between chromosomes and the nuclear envelope. Mutations in genes encoding LEM-D proteins cause human laminopathies that are associated with tissue-restricted pathologies. Drosophila has five genes that encode proteins with LEM homology. Using yeast two-hybrid analyses, we demonstrate that four encode proteins that bind Drosophila (d)BAF. In addition to dBAF, dMAN1 associates with lamins, the LEM-D protein Bocksbeutel, and the receptor-regulated Smads, demonstrating parallel protein interactions with vertebrate homologs. P-element mobilization was used to generate null dMAN1 alleles. These mutants showed decreased viability, with surviving adults displaying male sterility, decreased female fertility, wing patterning and positioning defects, flightlessness, and locomotion difficulties that became more severe with age. Increased phospho-Smad staining in dMAN1 mutant wing discs is consistent with a role in transforming growth factor (TGF)-β/bone morphogenic protein (BMP) signaling. The tissue-specific, age-enhanced dMAN1 mutant phenotypes are reminiscent of human laminopathies, suggesting that studies in Drosophila will provide insights into lamina dysfunction associated with disease.
Three α-Subunits of Heterotrimeric G Proteins and an Adenylyl Cyclase Have Distinct Roles in Fruiting Body Development in the Homothallic Fungus Sordaria macrospora
Authors: Kamerewerd Jens , Jansson Malin , Nowrousian Minou , Pöggeler Stefanie , Kück Ulrich
Published: August 2008

Sordaria macrospora, a self-fertile filamentous ascomycete, carries genes encoding three different α-subunits of heterotrimeric G proteins (gsa, G protein Sordaria  alpha subunit). We generated knockout strains for all three gsa genes (Δgsa1, Δgsa2, and Δgsa3) as well as all combinations of double mutants. Phenotypic analysis of single and double mutants showed that the genes for Gα-subunits have distinct roles in the sexual life cycle. While single mutants show some reduction of fertility, double mutants Δgsa1Δgsa2 and Δgsa1Δgsa3 are completely sterile. To test whether the pheromone receptors PRE1 and PRE2 mediate signaling via distinct Gα-subunits, two recently generated Δpre strains were crossed with all Δgsa strains. Analyses of the corresponding double mutants revealed that compared to GSA2, GSA1 is a more predominant regulator of a signal transduction cascade downstream of the pheromone receptors and that GSA3 is involved in another signaling pathway that also contributes to fruiting body development and fertility. We further isolated the gene encoding adenylyl cyclase (AC) (sac1) for construction of a knockout strain. Analyses of the three ΔgsaΔsac1 double mutants and one Δgsa2Δgsa3Δsac1 triple mutant indicate that SAC1 acts downstream of GSA3, parallel to a GSA1–GSA2-mediated signaling pathway. In addition, the function of STE12 and PRO41, two presumptive signaling components, was investigated in diverse double mutants lacking those developmental genes in combination with the gsa genes. This analysis was further completed by expression studies of the ste12 and pro41 transcripts in wild-type and mutant strains. From the sum of all our data, we propose a model for how different Gα-subunits interact with pheromone receptors, adenylyl cyclase, and STE12 and thus cooperatively regulate sexual development in S. macrospora.
Genetic Basis of Sex-Specific Color Pattern Variation in Drosophila malerkotliana
Authors: Ng Chen Siang , Hamilton Andrew M , Frank Amanda , Barmina Olga , Kopp Artyom
Published: August 2008

Pigmentation is a rapidly evolving trait that can play important roles in mimicry, sexual selection, thermoregulation, and other adaptive processes in many groups of animals. In Drosophila, pigmentation can differ dramatically among closely related taxa, presenting a good opportunity to dissect the genetic changes underlying species divergence. In this report, we investigate the genetic basis of color pattern variation between two allopatric subspecies of Drosophila malerkotliana, a widespread member of the ananassae species subgroup. In D. malerkotliana malerkotliana, the last three abdominal segments are darkly pigmented in males but not in females, while in D. malerkotliana pallens both sexes lack dark pigmentation. Composite interval mapping in F2 hybrid progeny shows that this difference is largely controlled by three quantitative trait loci (QTL) located on the 2L chromosome arm, which is homologous to the 3R of D. melanogaster (Muller element E). Using highly recombinant introgression strains produced by repeated backcrossing and phenotypic selection, we show that these QTL do not correspond to any of the candidate genes known to be involved in pigment patterning and synthesis in Drosophila. These results, in combination with similar analyses in other Drosophila species, indicate that different genetic and molecular changes are responsible for the evolution of similar phenotypic traits in different lineages. This feature makes Drosophila color patterns a powerful model for investigating how the genetic basis of trait evolution is influenced by the intrinsic organization of regulatory pathways controlling the development of these traits.
UBIQUITIN-SPECIFIC PROTEASE 26 Is Required for Seed Development and the Repression of PHERES1 in Arabidopsis
Authors: Luo Ming , Luo Ming-Zhu , Buzas Diana , Finnegan Jean , Helliwell Chris , Dennis Elizabeth S , Peacock W J , Chaudhury Abed
Published: August 2008

The Arabidopsis mutant Atubp26 initiates autonomous endosperm at a frequency of ∼1% in the absence of fertilization and develops arrested seeds at a frequency of ∼65% when self-pollinated. These phenotypes are similar to those of the FERTILIZATION INDEPENDENT SEED (FIS) class mutants, mea, fis2, fie, and Atmsi1, which also show development of the central cell into endosperm in the absence of fertilization and arrest of the embryo following fertilization. Atubp26 results from a T-DNA insertion in the UBIQUITIN-SPECIFIC PROTEASE gene AtUBP26, which catalyzes deubiquitination of histone H2B and is required for heterochromatin silencing. The paternal copy of AtUBP26 is able to complement the loss of function of the maternal copy in postfertilization seed development. This contrasts to the fis class mutants where the paternal FIS copy does not rescue aborted seeds. As in the fis class mutants, the Polycomb group (PcG) complex target gene PHERES1 (PHE1) is expressed at higher levels in Atubp26 ovules than in wild type; there is a lower level of H3K27me3 at the PHE1 locus. The phenotypes suggest that AtUBP26 is required for normal seed development and the repression of PHE1.
The Pleiotropic Phenotype of Apc Mutations in the Mouse: Allele Specificity and Effects of the Genetic Background
Authors: Halberg Richard B , Chen Xiaodi , Amos-Landgraf James M , White Alanna , Rasmussen Kristin , Clipson Linda , Pasch Cheri , Sullivan Ruth , Pitot Henry C , Dove William F
Published: August 2008

Familial adenomatous polyposis (FAP) is a human cancer syndrome characterized by the development of hundreds to thousands of colonic polyps and extracolonic lesions including desmoid fibromas, osteomas, epidermoid cysts, and congenital hypertrophy of the pigmented retinal epithelium. Afflicted individuals are heterozygous for mutations in the APC gene. Detailed investigations of mice heterozygous for mutations in the ortholog Apc have shown that other genetic factors strongly influence the phenotype. Here we report qualitative and quantitative modifications of the phenotype of Apc mutants as a function of three genetic variables: Apc allele, p53 allele, and genetic background. We have found major differences between the Apc alleles Min and 1638N in multiplicity and regionality of intestinal tumors, as well as in incidence of extracolonic lesions. By contrast, Min mice homozygous for either of two different knockout alleles of p53 show similar phenotypic effects. These studies illustrate the classic principle that functional genetics is enriched by assessing penetrance and expressivity with allelic series. The mouse permits study of an allelic gene series on multiple genetic backgrounds, thereby leading to a better understanding of gene action in a range of biological processes.
Venny Snellman, Finnish Nurses, and Rockefeller Foundation Support, 1929–1956
Authors: Tallberg Marianne
Published: August 2008

This paper describes how the Rockefeller Foundation finally came to take an interest in Finland. All sources point to the same conclusion: it was the Finnish nursing leader Venny Snellman who opened the door for the cooperation between Finland’s healthcare organizations and the Rockefeller Foundation.
Antiangiogenic Effects of Chinese Medicines (Hachimijiogan and Kogikujiogan) on Vascular Endothelial Growth Factor-A-Induced Tube Formation in Human Umbilical Vein Endothelial Cells Co-Cultured with Fibroblasts
Authors: Uchibayashi Rumi , Yokoyama Yuri , Nakajima Yoshimi , Matsunaga Nozomu , Shimazawa Masamitsu , Hara Hideaki
Published: August 2008

The aim of this study was to examine the antiangiogenic properties and antioxidant activities of two Chinese medicines (Hachimijiogan and Kogikujiogan). Each of these medicines concentration-dependently inhibited vascular endothelial growth factor-A (VEGF-A)-induced tube formation in a co-culture of human umbilical vein endothelial cells (HUVECs) and fibroblasts. In addition, they each at 100 ?g/ml inhibited the VEGF-A-induced cell proliferation of HUVECs. Hachimijiogan at 10 and 100 ?g/ml and Kogikujiogan at 100 ?g/ml also inhibited the VEGF-A-induced cell migration of HUVECs, and Hachimijiogan at 50 ?g/ml and Kogikujiogan at 5, 50, and 100 ?g/ml inhibited lipid peroxidation in mouse forebrain homogenates. These findings indicate that Hachimijiogan and Kogikujiogan have antiangiogenic and antioxidant effects, however, the contribution of their antioxidant property towards the observed anti-angiogenic effects requires further investigation.
Phylogenetic relationships of aroids and duckweeds (Araceae) inferred from coding and noncoding plastid DNA
Authors: Cabrera Lidia I. , Salazar Gerardo A. , Chase Mark W. , Mayo Simon J. , Bogner Josef , Dávila Patricia
Published: August 2008

Familial, subfamilial, and tribal monophyly and relationships of aroids and duckweeds were assessed by parsimony and Bayesian phylogenetic analyses of five regions of coding (rbcL, matK) and noncoding plastid DNA (partial trnK intron, trnL intron, trnL–trnF spacer) for exemplars of nearly all aroid and duckweed genera. Our analyses confirm the position of Lemna and its allies (formerly Lemnaceae) within Araceae as the well‐supported sister group of all aroids except Gymnostachydoideae and Orontioideae. The last two subfamilies form the sister clade of the rest of the family. Monophyly of subfamilies Orontioideae, Pothoideae, Monsteroideae, and Lasioideae is supported, but Aroideae are paraphyletic if Calla is maintained in its own subfamily (Calloideae). Our results suggest expansion of the recently proposed subfamily Zamioculcadoideae (Zamioculcas, Gonatopus) to include Stylochaeton and identify problems in the current delimitation of tribes Anadendreae, Heteropsideae, and Monstereae (Monsteroideae), Caladieae/Zomicarpeae, and Colocasieae (Aroideae). Canalization of traits of the spathe and spadix considered typical of Araceae evolved after the split of Gymnostachydoideae, Orontioideae, and Lemnoideae. An association with aquatic habitats is a plesiomorphic attribute in Araceae, occurring in the helophytic Orontioideae and free‐floating Lemnoideae, but evolving independently in various derived aroid lineages including free‐floating Pistia (Aroideae).
Pollinator and nonpollinator selection on ray morphology inLeucanthemum vulgare(oxeye daisy, Asteraceae)
Authors: Andersson Stefan
Published: August 2008

Despite evidence that both pollinators and nonpollinator agents of selection can shape the evolution of floral characters, there have been few attempts to compare the strengths and directions of selection from pollinators and other agents in the same study system. In this investigation ofLeucanthemum vulgare, a self‐incompatible composite known for its conspicuous white rays, I obtained data from a ray removal experiment in the field and from a segregating F2population in an experimental garden to assess the role of pollinator and nonpollinator selection as stabilizing factors on floral evolution in this species. Removal of all rays reduced the pollination success of heads by 31–35%, but did not significantly affect the level of infestation by larvae of the flyTephritis neesii. Data from F2plants indicated a potential for indirect selection on ray morphology, mediated through links between ray morphology and measures of vegetative size and plant vigor. The results of this study show that individuals of the normal, rayed phenotype have a clear selective advantage, in terms of both pollinator attraction and general plant vigor. Thus, there were no conflicting selection pressures between the pollinators and the other selective agents considered in this study.
Safe Use of Radioisotopes
Authors: Meisenhelder Jill , Bursik Steve
Published: August 2008

The pursuit of scientific knowledge has been considerably advanced by the use of biochemical molecules that incorporate radioisotopes at specific sites. The fate of these labeled molecules, and/or the radiolabeled products that result from biochemical reactions in which the parent molecule was involved, can be traced using a variety of instruments that detect radioactivity. This appendix begins with a discussion of the principles of radioactivity in order to provide the reader/user with knowledge on which to base a common sense approach to the safe use of isotopes. The characteristics of isotopes most commonly used in a molecular biology laboratory are then detailed, as well as the safety precautions and monitoring methods peculiar to each one. Detection and imaging methods used in experimental analysis are reviewed. Finally, an outline of an orderly response to a spill of radioactive material is presented. Curr. Protoc. Toxicol. 37:A.1A.1‐A.1A.18. © 2008 by John Wiley & Sons, Inc.
ErbB2 Transgenic Mice: A Tool for Investigation of the Immune Prevention and Treatment of Mammary Carcinomas
Authors: Quaglino Elena , Mastini Cristina , Forni Guido , Cavallo Federica
Published: August 2008

The epidermal growth factor receptor belongs to a superfamily of receptor tyrosine kinases (RTK) that includes ErbB2. ErbB2 is involved in normal physiological processes, such as embryogenesis, cell proliferation, differentiation, adhesion motility, and apoptosis, while its malfunction or overexpression is responsible for development defects, diabetes, and cancer. The human ortholog of ErbB2 is referred as Her‐2 (human ErbB2) while the rat ortholog is referred as neu (rat ErbB2). As ErbB2 is directly involved in carcinogenesis, mice transgenic for the rat neu oncogene allow straightforward assessment of the ability of drugs and vaccines to inhibit the progression of neu‐driven cancer. Information from this model may provide indications on the efficacy of similar treatments in patients. This commentary provides key information regarding the use of these transgenic mouse models for evaluation of the efficacy of anti‐tumor strategies. Curr. Protoc. Immunol. 82:20.9.1‐20.9.10. © 2008 by John Wiley & Sons, Inc.
Characterization of Heat and Momentum Transfer in Sintered Metal Foams
Authors: Reutter O. , Sauerhering J. , Fend T. , Pitz‐Paal R. , Angel S.
Published: August 2008

In this study, metal foams made by the Slip Reaction Foam Sintering (SRFS)‐process are investigated concerning their thermophysical and permeability properties. Since the foam is to be applied as a functional and structural element in the effusion air cooling system of a stationary gas turbine combustion chamber, these properties are of major interest for the calculation of the temperature distribution inside the combustion chamber walls, which may be critical for the employed materials. Experimental set‐ups are presented, which are used to determine permeability, the volumetric heat transfer coefficient and the effective thermal conductivity. The results are presented for a wide range of foam materials. Porosity as well as the basic metal powder and the manufacturing parameters are varied. The influence of these parameters on the measured quantities is discussed. Thermal conductivity data are determined at temperatures of up to 1200 K. The obtained volumetric heat transfer coefficients are transferred to Nusselt–Reynolds plots, which allow generalization to the high temperature and high pressure regime. Correlations between the heat transfer properties and the permeability data are made. Using the acquired experimental data, a proposal is made for the calculation of the inner surface temperature of the combustion chamber as well as the temperature distribution inside the chamber wall, which consists of a structural element, the metal foam and a thermal barrier coating, equipped with laser drilled micro‐holes.
Photooxygenation Catalysis with a Polyol‐Decorated Disc‐Shaped Porphyrin Sensitizer: Shell‐Recognition Effects
Authors: Griesbeck Axel G. , Schäfer Mathias , Uhlig Johannes
Published: August 2008

Polar meso‐tetraarylporphyrins 2–4 were synthesized from tetrakis‐4‐hydroxyphenylporphyrin 1 as the central building block by consecutive base‐induced reactions with glycidol. The decorating units form a polar hydrogen‐bonded shell around the sensitizer core which is proposed as the binding site for polar substrates in photocatalyzed oxygenation reactions. As substrate, the polarity‐sensor mesitylol (5) was applied and the reaction constrained in a polystyrene matrix. Increasing shell dimensions lead to increased diastereoselectivities for the allylic hydroperoxides 6 and thus clearly demonstrate the concept of shell‐induced substrate stereoselectivity in singlet oxygen reactions.
Enantioselective Organocatalytic Reactions of 4‐Hydroxycoumarin and 4‐Hydroxypyrone with α,β‐Unsaturated Aldehydes – An Efficient Michael Addition‐Acetalization Cascade to Chromenones, Quinolinones and Pyranones
Authors: Rueping Magnus , Merino Estíbaliz , Sugiono Erli
Published: August 2008

An efficient, organocatalytic enantioselective addition‐cyclization reaction of cyclic 1,3‐dicarbonyl compounds with different α,β‐unsaturated aldehydes has been developed. The diarylprolinol ether‐catalyzed reaction cascade provides a variety of chromenones, quinolinones and pyranones in good yields and with excellent enantioselectivities.
Differential association between MAOA, ADHD and neuropsychological functioning in boys and girls
Authors: Rommelse Nanda N.J. , Altink Marieke E. , Arias‐Vásquez Alejandro , Buschgens Cathelijne J.M. , Fliers Ellen , Faraone Stephen V. , Buitelaar Jan K. , Sergeant Joseph A. , Oosterlaan Jaap , Franke Barbara
Published: August 2008

Attention‐deficit/hyperactivity disorder (ADHD) is more common in boys than in girls. It has been hypothesized that this sex difference might be related to genes on the X‐chromosome, like Monoamine Oxidase A (MAOA). Almost all studies on the role of MAOA in ADHD have focused predominantly on boys, making it unknown whether MAOA also has an effect on ADHD in girls, and few studies have investigated the relationship between MAOA and neuropsychological functioning, yet this may provide insight into the pathways leading from genotype to phenotype. The current study set out to examine the relationship between MAOA, ADHD, and neuropsychological functioning in both boys (265 boys with ADHD and 89 male non‐affected siblings) and girls (85 girls with ADHD and 106 female non‐affected siblings). A haplotype was used based on three single nucleotide polymorphisms (SNPs) (rs12843268, rs3027400, and rs1137070). Two haplotypes (GGC and ATT) captured 97% of the genetic variance in the investigated MAOA SNPs. The ATT haplotype was more common in non‐affected siblings (P = 0.025), conferring a protective effect for ADHD in both boys and girls. The target and direction of the MAOA effect on neuropsychological functioning was different in boys and girls: The ATT haplotype was associated with poorer motor control in boys (P = 0.002), but with better visuo‐spatial working memory in girls (P = 0.01). These findings suggest that the genetic and neuropsychological mechanisms underlying ADHD may be different in boys and girls and underline the importance of taking into account sex effects when studying ADHD. © 2008 Wiley‐Liss, Inc.
Porphyrine mit metallorganischen Gruppen: Synthese und Anwendungen
Authors: Suijkerbuijk Bart M. J. M. , Klein Gebbink Robertus J. M.
Published: August 2008

Die Koordinationschemie der Porphyrine dreht sich vornehmlich um den Einbau von Metallionen unterschiedlicher Ladung und Größe in den Tetrapyrrolkern, um Metalloporphyrine mit neuen Eigenschaften zu erhalten. Eine Organometallchemie der Porphyrine muss sich aber nicht zwangsläufig auf das im Porphyrinkern gebundene Metallion beschränken, sondern sie kann sich auch auf die Molekülperipherie erstrecken: Der Porphyrinmakrocyclus kann durch direkte Metallierung in meso‐ oder β‐Stellung modifiziert oder aber mit Liganden verknüpft werden, die anschließend eine Metallierung eingehen. Dieser Aufsatz beschreibt Synthesestrategien für Porphyrine mit Metall‐Kohlenstoff‐Bindungen in der Molekülperipherie. Die beachtenswerten Ergebnisse, die hierbei erzielt wurden, heben die Bedeutung dieses Forschungsgebiets hervor und zeigen Perspektiven auf.
Phase behavior of blends containing amorphous poly(resorcinol phthalate‐block‐carbonate) and semicrystalline polyesters
Authors: Kim Sung Dug , Chakravarti Shreyas , Tian Jun
Published: August 2008

The phase behavior of poly(resorcinol phthalate‐block‐carbonate) (RPC) with engineering polyesters was investigated by using differential scanning calorimeter (DSC) and dynamic mechanical analysis. RPC was found to form miscible blends with poly(ethylene terephthalate) (PET), poly(butylene terephthalate) (PBT), and poly(cyclohexylmethylene terephthalate) (PCT), but was partially miscible with poly(1,4‐cyclohexanedimethylene‐1,4‐cyclohexanedicarboxylate) (PCCD) in the melt state and below the melting temperature (Tm). The degree of melting‐point depression indicates that the RPC is most miscible with PCT followed by PET and then PBT. Furthermore, with the help of empirical DSC data and the Nishi–Wang equation, the interaction parameters between RPC and PET, PBT, and PCT were quantified to be −0.36, −0.33, and −0.54, respectively. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Vapor–liquid equilibria for polymer solutions through a group‐contribution method: Chain‐length dependence
Authors: Lee Seung Seok , Sun Yang Kook , Bae Young Chan
Published: August 2008

A new group‐contribution model based on the modified double‐lattice theory considering chain‐length dependence of the universal parameters was developed and applied to describe the vapor–liquid equilibria of polymer solutions. The proposed model includes the combinatorial energy contribution that is responsible for the revised Flory–Huggins entropy of mixing, the van der Waals energy contribution from dispersion and polar forces, and the specific energy contribution from hydrogen bonding. The quantitative description according to the proposed model was in good agreement with experimentally observed solvent activities of polymer solutions. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Role of Intraflagellar Transport and Primary Cilia in Skeletal Development
Authors: Serra Rosa
Published: August 2008

Primary cilia are nonmotile microtubule‐based appendages extending from the surface of almost all vertebrate cells. The process of intraflagellar transport (IFT) is responsible for building and maintaining the structure and function of primary cilia. Disruption of Kif3a, a component of the Kinesin‐II motor complex, disables anterograde IFT and leads to failure in the formation and maintenance of cilia. Likewise, the absence of IFT88/Tg737/Polaris, a core component of the IFT particle, results in the loss of cilia. Although primary cilia were described on chondrocytes almost 40 years ago, only recently has the functional significance of IFT and cilia in skeletal development been uncovered through the use of mouse models containing mutations or deletions in genes required to make and maintain cilia. Together, the results indicate that primary cilia/IFT are involved in coordinating multiple signaling pathways within the skeleton. Anat Rec, 291:1049–1061, 2008. © 2008 Wiley‐Liss, Inc.
The Primary Cilium of Connective Tissue Cells: Imaging by Multiphoton Microscopy
Authors: Donnelly Eve , Williams Rebecca , Farnum Cornelia
Published: August 2008

Although the role of the primary cilium as a sensory organelle in epithelial cells has been elucidated significantly over the past decade, the function of primary cilia in connective tissue cells has been studied less extensively. Primary cilia have been implicated as mechanotransducers in connective tissues, but the mechanisms by which the cells sense loads and convert them to biochemical signals for tissue formation and adaptation are poorly understood. Before hypotheses regarding the function of the primary cilium in connective tissue cells can be tested, methods for quantitation of incidence as well as three‐dimensional visualization of primary cilia with respect to the extracellular matrix (ECM) are needed. The objective of this study was to develop a rapid method for visualizing primary cilia in their native ECM in a wide range of connective tissues. Whole‐mount immunohistochemical and multiphoton microscopy techniques were developed to simultaneously image primary cilia, cell nuclei, and collagen and their relationships to each other in situ. Axonemes of primary cilia projecting into the ECM were successfully visualized in thick sections of growth plate cartilage, tendon, ligament, meniscus, intervertebral disc, and perichondrium. These methodologies will allow analysis of the incidence and three‐dimensional orientation of primary cilia and enable investigation of the role of primary cilia in normal and pathological growth and adaptation in a variety of musculoskeletal tissues. Anat Rec, 291:1062–1073, 2008. © 2008 Wiley‐Liss, Inc.
Anatomy of Smooth Muscle Cells in Nonmalignant and Malignant Human Prostate Tissue
Authors: Taboga Sebastião R. , Scortegagna Eduardo , Siviero Maristela P. , Carvalho Hernandes F.
Published: August 2008

Differently graded areas of human prostate adenocarcinoma were examined after Masson's trichrome staining or immunohistochemistry for smooth muscle alpha‐actin, type IV collagen and laminin. In addition, the ultrastructure of the prostatic smooth muscle cells (SMC) during glandular proliferation and epithelial invasion in selected tumors was studied. The SMC formed a thick layer below the epithelial structures in unaffected areas and were closely associated with each other in homotypic interactions. As the tumor grade increased, the SMC gradually lost interactions with each other and became atrophic. With the growth of the epithelial compartment, the SMC initially segregated to the tumor periphery and the intercellular spaces increased. In high grade tumors, the epithelial cancer cells invaded the spaces between the SMC. Immunohistochemical analysis of the basal membrane revealed increased disruption of the usually thick basal membrane, which became thinner and faintly stained with each of the antibodies used. We conclude that most SMC become atrophic following epithelial invasion in human tumors and that degradation of the basal membrane is an important factor in this process. At the ultrastructural level, different SMC phenotypes occur in prostatic tissues during epithelial invasion. Interconversion between these phenotypes is suggested and a probable relationship among them is proposed. Anat Rec, 291:1115–1123, 2008. © 2008 Wiley‐Liss, Inc.
Correlation and Immunolocalization of Substance P Nerve Fibers and Activated Immune Cells in Human Chronic Gastritis
Authors: Sipos Gábor , Sipos Péter , Altdorfer Károly , Pongor Éva , Fehér Erzsébet
Published: August 2008

Neuropeptides are able to modulate cytokine production by macrophages in response to various stimulators and have a major role in inflammation of different organs. Mammalian poly (ADP‐ribose) polymerase (PARP) and nuclear factor kappa B (NF‐κB) both have been suggested to play a crucial role in inflammatory disorders. Unregulated increase of tumor necrosis factor‐α (TNF‐α) may also be pathogenic in inflammatory diseases. The aim of this study was to investigate the correlation between the number of Substance P (SP) containing nerve fibers and activated immune cells using immunohisto‐, immunocytochemical (EM) and confocal laser microscopic methods. To investigate expression and activation of immune cells gastric biopsy samples from patients with chronic gastritis were used. The number of SP containing nerve fibers and activated immune cells increased significantly in gastritis. Using monoclonal p65 antibody, activated NF‐κB was found in inflamed mucosa but was absent in uninflamed mucosa. Immunobinding for the activated form of p65 of NF‐κB was found in 22% of macrophages and 45% of lymphocytes. The number of immune cells showing IR for NF‐κB, PARP and TNF‐α correlated with the increasing number of SP containing fibres. Confocal laser microscopy was used to confirm the colocalization of SP in TNF‐α and NFκB positive lymphocytes and mast cells in inflamed mucosa. Immunoelectronmicroscopic investigation confirmed that these cells belong to lymphocytes, mast cells and macrophages. Conclusions: The increase of SP in nerve fibers and in activated immune cells further activate the production of other proinflammatory mediators (e.g. TNF‐α) and therefore generate the chronic inflammation. Anat Rec, 291:1140–1148, 2008. © 2008 Wiley‐Liss, Inc.
Abnormal Myocardial and Coronary Vasculature Development in Experimental Hypoxia
Authors: Nanka Ondrej , Krizova Petra , Fikrle Michal , Tuma Michal , Blaha Milan , Grim Milos , Sedmera David
Published: August 2008

Oxygen availability is one of the necessary prerequisites for normal embryonic development. In our previous study we found that quail embryos incubated under hypoxic conditions (16% O2) die at embryonic day (ED) 9 with signs of heart failure. By ED4 and ED6 we found thinner ventricular wall and increased capillary density. We thus hypothesized that the cause of death would lie in severe myocardial and coronary maldevelopment. ED6 and 7 hypoxic hearts had thinner ventricular wall, especially left. There was a simultaneous increase in capillary density, most pronounced in the interventricular septum. This site corresponds to an area of tissue hypoxia and ensuing increased angiogenesis, and also formation of ventricular conduction system. Hypoxia had a positive effect on normal sequence of maturation of the conduction system evaluated by optical mapping at ED7. In sections from ED9 hypoxic hearts we found, in addition to thinner ventricular walls, irregularities in development of coronary tree (missing coronary ostia, absence of one coronary artery, and irregular arterial wall). This deficiency was due to decreased myocyte proliferation rather than to increased apoptosis. By Indian ink injection through the left ventricle we found in normoxic hearts regular coronary branching pattern, while in the hypoxic ones there was often only an irregular plexus. Embryonic hypoxia thus leads to increased capillarity and trabeculation to minimize diffusion distance. In the subsequent period there is a failure in organization of vascular plexus into normal vasculature, resulting in thin compact myocardium that likely leads to heart failure and embryonic death. Anat Rec, 2008. © 2008 Wiley‐Liss, Inc.
Lymphoid Tissue Ontogeny in the Mummichog, Fundulus heteroclitus
Authors: Hunt Laura R. , Rice Charles D.
Published: August 2008

Most studies that examine the ontogeny of lymphoid organ development in teleostean fishes use species of interest to aquaculture or genetic research and, to date, have focused strictly on marine or freshwater species. The mummichog, Fundulus heteroclitus, also known as the estuarine killifish, is a unique model for studies on developmental immunobiology, because it is euryhaline, has a high degree of thermal tolerance, and has a unique reproductive strategy. Embryonic and larval mummichogs were examined for the ontogeny of lymphoid tissue development. The first lymphoid organ to appear was the head kidney at 1 dph, followed by the spleen at 1 wph, and then the thymus at 3 wph. Rag‐1 was partially cloned and sequenced and shown to be highly conserved among other vertebrate Rag‐1 genes. Using QT‐PCR to monitor the temporal expression of Rag‐1, it was shown to reach a maximum intensity at 3 and 4 wph and then to drop to pre‐2‐wph levels. Overall, this study suggests that juvenile mummichogs do not possess the ability to mount T‐ or B‐cell responses until some time after 5 wph. Even though the estuarine killifish tolerates a wide range of salinities, the developmental patterns of lymphoid tissues are similar to what has been reported for strictly marine (stenohaline) teleosts. Thus, the mummichog should be a convenient model for understanding the developmental immunobiology of most marine teleosts. Anat Rec, 2008. © 2008 Wiley‐Liss, Inc.
Glucose Transporter Distribution in the Vessels of the Central Nervous System of the Axolotl Ambystoma mexicanum (Urodela: Ambystomatidae)
Authors: Lazzari Maurizio , Bettini Simone , Ciani Franco , Franceschini Valeria
Published: August 2008

The GLUT‐1 isoform of the glucose transporter is commonly considered a reliable molecular marker of blood–brain barrier endothelia in the neural vasculature organized in a three‐dimensional network of single vessels. The central nervous system of the axolotl Ambystoma mexicanum is characterized by a vascular architecture that contains both single and paired vessels. The presence and distribution of the GLUT‐1 transporter are studied in this urodele using both immunoperoxidase histochemistry and immunogold technique. Light microscopy reveals immunopositivity in both parenchymal and meningeal vessels. The transverse‐sectioned pairs of vessels do not show the same size. Furthermore, in the same pair, the two elements often differ in diameter. The main regions of the central nervous system show a different percentage of the paired structures. Only immunogold cytochemistry reveals different staining intensity in the two adjoined elements of a vascular pair. Colloidal gold particles show an asymmetric distribution in the endothelia of both single and paired vessels. These particles are more numerous on the abluminal surface than on the luminal one. The particle density is calculated in both vascular types. The different values could indicate functional differences between single and paired vessels and between the two adjoined elements of a pair, regarding glucose transport. Anat Rec, 2008. © 2008 Wiley‐Liss, Inc.
Biglycan Overexpression on Tooth Enamel Formation in Transgenic Mice
Authors: Wen Xin , Zou Yanming , Luo Wen , Goldberg Michel , Moats Rex , Conti Peter S. , Snead Malcolm L. , Paine Michael L.
Published: August 2008

Previously, it was shown that the volume of forming enamel of molar teeth in biglycan‐null mice was greater than that in genetically matched wild‐type mice. This phenotypic change appeared to result from an increase in amelogenin expression, implying that biglycan directly influences amelogenin synthesis. To determine whether biglycan overexpression resulted in decreased amelogenin expression, we engineered transgenic mice to overexpress biglycan in the enamel organ epithelium. Biglycan overexpression did not significantly affect the amelogenin expression in incisor and molar teeth in 3‐day postnatal transgenic mice. In the transgenic animals, we observed that the immature and mature enamel appeared normal. These results suggested that increasing the biglycan expression, in the cells that synthesize the precursor protein matrix for enamel, has a negligible influence on amelogenesis. Anat Rec, 2008. © 2008 Wiley‐Liss, Inc.
The reduction of starch accumulation in transgenic sugarcane cell suspension culture lines
Authors: Ferreira Stephanus J. , Kossmann Jens , Lloyd James R. , Groenewald Jan‐Hendrik
Published: August 2008

Starch only occurs in small amounts in sugarcane, but is, nevertheless an unwanted product because it reduces the amount of sucrose that can be crystallized from molasses. In an attempt to reduce the starch content of sugarcane, the activities of ADP‐glucose pyrophosphorylase (AGPase) and β‐amylase were manipulated using transgenic approaches. Transformation vectors to reduce AGPase activity and to increase plastidial β‐amylase activity were constructed and used for the transformation of sugarcane calli. The results of the manipulations were analyzed in suspension cultures. AGPase activity was reduced down to between 14 and 54% of the wild‐type control. This led to a reduction in starch concentration down to 38% of the levels of the wild‐type control. β‐Amylase activity was increased in the transgenic lines by 1.5–2 times that of the wild‐type control. This increase in activity led to a reduction in starch amounts by 90% compared to wild‐type control cells. In both experiments, the changes in starch concentrations could be correlated with the change in enzyme activity. There were no significant effects on sucrose concentrations in either experiment, indicating that these approaches might be useful to engineer regenerated sugarcane for optimized sucrose production.
Driving on liquid sunshine – the Brazilian biofuel experience: a policy driven analysis
Authors: Zapata Clovis , Nieuwenhuis Paul
Published: August 2008

This paper analyses Brazil's experience with biofuels, focusing on the central role of the federal government as the main force driving the implementation of alternative locally produced ethanol (ethyl alcohol) and biodiesel. The pioneering, large scale ethanol programme that started over 30 years ago can be considered the most successful experience with the use of biofuels to date, as the government was able to rapidly implement the use of ethanol (ethyl alcohol) as a substitute for petrol in the 1970s and 1980s. The work contributes to the general discussion of sustainable and renewable energy sources and sets out the key policy mechanisms used. The paper also innovatively looks at the second large governmental intervention in the renewable fuels market – the biodiesel programme. In addition to the contribution to the debate surrounding command‐and‐control measures and economic incentive instruments, the paper analyses how lessons learned from the ethanol experiment were taken into consideration in the design and implementation of the biodiesel mandate, including social and environmental facets. It emphasizes the uniqueness of producing sugarcane ethanol in the Brazilian context and how attempts to carry out similar fast growing biofuels programmes may not be possible in other parts of the world. Copyright © 2008 John Wiley & Sons, Ltd and ERP Environment.
Simultaneous Doppler Tracing of the Mitral Inflow and Annular Motion Provides a Useful Means of Evaluating Left Ventricular Diastolic Function
Authors: Choi Jin‐Oh , Park Seung Woo , Shin Dae‐Hee , Han Hyejin , Cho Sungwon , Kim Jun Hyung , Song Young Bin , Lee Sang‐Chol
Published: August 2008

Background

In this study, we evaluated the feasibility and clinical usefulness of TS, the time interval between the onsets of early diastolic mitral inflow velocity (E) and mitral annular velocity (E′), obtained by simultaneously tracing E and E′, in terms of evaluating diastolic function.

Methods

By the diastolic functional status, 105 patients were allocated to abnormal relaxation, pseudonormal filling (PN), or normal diastolic function groups (n = 30, 43, and 32, respectively). The TS was measured in the same cardiac cycle by the pulsed‐wave Doppler (PWD) tracing of mitral inflow near the septal annulus with appropriate filter and gain settings.

Results

TS was prolonged in the PN group versus the normal group (34.1 ± 12.2 msec versus 12.1 ± 8.5 msec, p≤0.001). The area under the receiver operating characteristic curve of TS for the detection of PN was 0.91 (95% confidence interval [CI]; 0.85 ∼ 0.97, p<0.001), and 24.0 msec was determined to be the optimal cut‐off value (specificity 83.7%, sensitivity 90.3%).

Conclusion

Simultaneous measurement of TS is feasible and clinically applicable for the grading of diastolic dysfunction (DD). Copyright © 2008 Wiley Periodicals, Inc.
Rapid and Accurate Quantification of Right Ventricular Volume and Stroke Volume by Real‐time 3‐Dimensional Triplane Echocardiography
Authors: Liu Ya‐Ni , Deng You‐Bin , Liu Bing‐Bing , Zhang Qing‐Yang
Published: August 2008

Background

Previous studies have demonstrated that 3‐Dimensional (3‐D) echocardiography can determine right ventricular (RV) volume accurately. However, this technique has not been feasible in everyday clinical practice because of the necessity of time‐consuming off‐line processes.

Hypothesis

A newly developed real‐time 3‐D triplane echocardiography, which acquires 3 apical rotational cross‐sectional images simultaneously, holds the promise to resolve these problems.

Methods and Results

Sixteen excised formalin fixed porcine hearts and 24 healthy human subjects underwent real‐time 3‐D triplane echocardiography. In an anatomic in vitro study, the actual volume of RV was obtained by spilling water in the RV cavity into a graduated cylinder for measurement, which served as a reference standard for comparison. For healthy subjects, the RV stroke volume (SV) was measured by triplane echocardiography which was compared with the left ventricular (LV) SV obtained by conventional 2‐Dimensional echocardiography (2‐DE). Excellent correlation and agreement between 3‐D triplane imaging derived RV volume and the actual one for excised porcine hearts were observed (r = 0.979, p < 0.001, mean difference 2.2 mL). In healthy human subjects, good correlation and agreement between 3‐D triplane imaging derived RV SV and LV SV measured by 2‐DE were obtained (r = 0.970, p < 0.001, mean difference 5.9 mL).

Conclusions

Real‐time 3‐D triplane echocardiography provides us a new method for rapid and accurate quantification of RV volume. Furthermore, this new method holds the promise for evaluating RV volume and SV in routine clinical practice. Copyright © 2008 Wiley Periodicals, Inc.
The Continuing Value of Invasive Coronary Angiography
Authors: Richard Conti C.
Published: August 2008

In 1975, Gofredo Gensini stated, “The primary goal of coronary arteriography is the identification, localization, and assessment of obstructive lesions present within the arteries of the heart.” The operative word here is assessment. I interpret assessment to mean determining the pathophysiologic significance (ischemia versus no ischemia) of the coronary stenosis in question. Copyright © 2008 Wiley Periodicals, Inc.