bluuebunny/crossref_metadata_2025 huggingface dataset:
The NuRD nucleosome remodelling complex and NHK-1 kinase are required for chromosome condensation in oocytes
Authors: Nikalayevich Elvira , Ohkura Hiroyuki
Published: December 2014

Chromosome condensation during cell division is one of the most dramatic events in the cell cycle. Condensin and topoisomerase II are the most studied factors in chromosome condensation. However, their inactivation leads to only mild defects and little is known about roles of other factors. Here we took advantage of Drosophila oocytes to elucidate the roles of potential condensation factors by RNAi. Consistent with previous studies, depletion of condensin I subunits or topoisomerase II in oocytes only mildly affected chromosome condensation. In contrast, we found severe undercondensation of chromosomes after depletion of the Mi-2 containing NuRD nucleosome remodelling complex or the protein kinase NHK-1. The further phenotypic analysis suggests that Mi-2 and NHK-1 are involved in different pathways in chromosome condensation. We show that the main role of NHK-1 in chromosome condensation is to phosphorylate BAF and suppress its activity in linking chromosomes to nuclear envelope proteins. We further showed that NHK-1 is important for chromosome condensation in mitosis as well as in oocytes.
Segregation of VE-cadherin from the LBRC depends on the ectodomain sequence required for homophilic adhesion
Authors: Feng Gong , Sullivan David P. , Han Fei , Muller William A.
Published: December 2014

The lateral border recycling compartment (LBRC) is a reticulum of perijunctional tubulovesicular membrane continuous with the plasmalemma of endothelial cells that is essential for efficient transendothelial migration (TEM) of leukocytes. The LBRC contains molecules involved in TEM such as PECAM, PVR, and CD99, but not VE-cadherin. Despite its importance, how membrane proteins are included in or excluded from the LBRC is not known. Immunoelectron microscopy and biochemical approaches demonstrate that inclusion into the LBRC is the default pathway for transmembrane molecules present at endothelial cell borders. A chimeric molecule composed of the extracellular domain of VE-cadherin and cytoplasmic tail of PECAM (VE-CAD/PECAM) did not enter the LBRC, suggesting that VE-cadherin was excluded by a mechanism involving its extracellular domain. Deletion of the homophilic interaction domain EC1 or the homophilic interaction motif RVDAE allowed VE-CAD/PECAM and even native VE-cadherin to enter the LBRC. Similarly, treatment with RVDAE peptide to block homophilic VE-cadherin interactions allowed endogenous VE-cadherin to enter the LBRC. This suggests that homophilic interactions of VE-cadherin stabilize it at cell borders and prevent entry into the LBRC.
The septation initiation network controls the assembly of nodes containing Cdr2p for cytokinesis in fission yeast
Authors: Pu Kai-Ming , Akamatsu Matthew , Pollard Thomas D.
Published: December 2014

In the fission yeast S. pombe cortical protein structures called interphase nodes help to prepare for cytokinesis by positioning precursors of the cytokinetic contractile ring, while the septation initiation network (SIN) regulates the onset of cytokinesis and septum formation. Previous work noted that one type of interphase node disappears during mitosis providing SIN activity is high. Here we used time-lapse fluorescence microscopy to provide evidence that SIN activity is necessary and sufficient to disperse the type 1 node proteins Cdr2p and Mid1p into the cytoplasm, so these nodes assemble only during interphase through early mitosis when SIN activity is low. Activating the SIN in interphase cells dispersed Cdr2p and anillin Mid1p from type 1 nodes a few minutes after the SIN kinase Cdc7p-GFP accumulated at spindle pole bodies. If the SIN was then turned off in interphase cells, Cdr2p and Mid1p reappeared in nodes in parallel with the decline in SIN activity. Hyperactivating SIN during mitosis dispersed type 1 nodes earlier than normal, and prolonged SIN activation prevented nodes from reforming at the end of mitosis.
Analysis ofS. pombeSIN protein SPB-association reveals two genetically separable states of the SIN
Authors: Wachowicz Paulina , Chasapi Anastasia , Krapp Andrea , Cano del Rosario Elena , Schmitter Daniel , Sage Daniel , Unser Michael , Xenarios Ioannis , Rougemont Jacques , Simanis Viesturs
Published: December 2014

The S. pombe Septation Initiation Network (SIN) regulates cytokinesis, and asymmetric association of SIN proteins with the mitotic spindle poles (SPBs) is important for its regulation. We have used semi-automated image analysis to study SIN proteins in large numbers of wild-type and mutant cells. Our principal conclusions are; First, the association of Cdc7p with the SPBs in early mitosis is asymmetric, with a bias in favour of the new SPB. Second, the early SPB association of Cdc7p-GFP depends on Plo1p but not Spg1p, and is unaffected by mutations that influence its asymmetry in anaphase. Third Cdc7p asymmetry in anaphase B is delayed by Pom1p and by activation of the spindle assembly checkpoint, and is promoted by Rad24p. Fourth, the length of the spindle, expressed as a fraction of the length of the cell, at which Cdc7p becomes asymmetric is similar in cells dividing at different sizes. These data reveal that multiple regulatory mechanisms control the SIN in mitosis and lead us to propose a two-state model to describe the SIN.
Nanoscale histone localization in live cells reveals reduced chromatin mobility in response to DNA damage
Authors: Liu Jing , Vidi Pierre-Alexandre , Lelièvre Sophie A. , Irudayaraj Joseph M. K.
Published: December 2014

Nuclear functions including gene expression, DNA replication, and genome maintenance intimately rely on dynamic changes in chromatin organization. The movements of chromatin fibers may play important roles in the regulation of these fundamental processes, yet the mechanisms controlling chromatin mobility are poorly understood due to methodological limitations for the assessment of chromatin movements. Here, we present a facile and quantitative technique that relies on photoactivation of GFP-tagged histones and paired-particle tracking to measure chromatin mobility in live cells. We validate the method by comparing live cells to ATP-depleted cells and show that chromatin movements in mammalian cells are predominantly energy-dependent. We also find that chromatin diffusion decreases in response to DNA breaks induced by a genotoxic drug or by the ISceI meganuclease. Time course analysis after cell exposure to ionizing radiations indicates that the decrease in chromatin mobility is transient and precedes subsequent increased mobility. Future applications of the method in the DNA repair field and beyond are discussed.
The dynamic conformational landscape of γ-secretase
Authors: Elad Nadav , De Strooper Bart , Lismont Sam , Hagen Wim , Veugelen Sarah , Arimon Muriel , Horré Katrien , Berezovska Oksana , Sachse Carsten , Chávez-Gutiérrez Lucía
Published: December 2014

The structure and function of the γ-secretase proteases are of vast interest because of their critical roles in cellular and disease processes. We established a novel purification protocol for γ-secretase complex that involves a conformation and complex-specific nanobody, yielding highly pure and active enzyme. Using single particle electron microscopy, we analyzed the γ-secretase structure and its conformational variability. Under steady state conditions the complex adopts three major conformations, which are different in overall compactness and relative position of the nicastrin ectodomain. Occupancy of the active or substrate binding sites by inhibitors differentially stabilize sub-populations of particles with compact conformations, whereas a Familial Alzheimer Disease-linked mutation results in enrichment of extended-conformation complexes with increased flexibility. Our study presents the γ-secretase complex as a dynamic population of inter-converting conformations, involving rearrangements at the nanometer scale and high level of structural interdependence between subunits. The fact that protease inhibition or clinical mutations, which affect Aβ generation, enrich for particular subpopulations of conformers indicates the functional relevance of the observed dynamic changes, which are likely instrumental for highly allosteric behavior of the enzyme.
Functional importance of Ψ38 and Ψ39 in distinct tRNAs, amplified for tRNAGln(UUG) by unexpected temperature sensitivity of the s2U modification in yeast
Authors: Han Lu , Kon Yoshiko , Phizicky Eric M.
Published: December 2014

The numerous modifications of tRNA play central roles in controlling tRNA structure and translation. Modifications in and around the anticodon loop often have critical roles in decoding mRNA and in maintaining its reading frame. Residues U38 and U39 in the anticodon stem–loop are frequently modified to pseudouridine (Ψ) by members of the widely conserved TruA/Pus3 family of pseudouridylases. We investigate here the cause of the temperature sensitivity of pus3Δ mutants of the yeast Saccharomyces cerevisiae and find that, although Ψ38 or Ψ39 is found on at least 19 characterized cytoplasmic tRNA species, the temperature sensitivity is primarily due to poor function of tRNAGln(UUG), which normally has Ψ38. Further investigation reveals that at elevated temperatures there are substantially reduced levels of the s2U moiety of mcm5s2U34 of tRNAGln(UUG) and the other two cytoplasmic species with mcm5s2U34, that the reduced s2U levels occur in the parent strain BY4741 and in the widely used strain W303, and that reduced levels of the s2U moiety are detectable in BY4741 at temperatures as low as 33°C. Additional examination of the role of Ψ38,39 provides evidence that Ψ38 is important for function of tRNAGln(UUG) at permissive temperature, and indicates that Ψ39 is important for the function of tRNATrp(CCA) in trm10Δ pus3Δ mutants and of tRNALeu(CAA) as a UAG nonsense suppressor. These results provide evidence for important roles of both Ψ38 and Ψ39 in specific tRNAs, and establish that modification of the wobble position is subject to change under relatively mild growth conditions.
An evolutionary approach uncovers a diverse response of tRNA 2-thiolation to elevated temperatures in yeast
Authors: Alings Fiona , Sarin L. Peter , Fufezan Christian , Drexler Hannes C.A. , Leidel Sebastian A.
Published: December 2014

Chemical modifications of transfer RNA (tRNA) molecules are evolutionarily well conserved and critical for translation and tRNA structure. Little is known how these nucleoside modifications respond to physiological stress. Using mass spectrometry and complementary methods, we defined tRNA modification levels in six yeast species in response to elevated temperatures. We show that 2-thiolation of uridine at position 34 (s2U34) is impaired at temperatures exceeding 30°C in the commonly used Saccharomyces cerevisiae laboratory strains S288C and W303, and in Saccharomyces bayanus. Upon stress relief, thiolation levels recover and we find no evidence that modified tRNA or s2U34 nucleosides are actively removed. Our results suggest that loss of 2-thiolation follows accumulation of newly synthesized tRNA that lack s2U34 modification due to temperature sensitivity of the URM1 pathway in S. cerevisiae and S. bayanus. Furthermore, our analysis of the tRNA modification pattern in selected yeast species revealed two alternative phenotypes. Most strains moderately increase their tRNA modification levels in response to heat, possibly constituting a common adaptation to high temperatures. However, an overall reduction of nucleoside modifications was observed exclusively in S288C. This surprising finding emphasizes the importance of studies that utilize the power of evolutionary biology, and highlights the need for future systematic studies on tRNA modifications in additional model organisms.
Experimental Study of the Effect of RCC Specimen Size and Crack Depth Ratio on Double-K Fracture Parameters
Authors: Cui Xinzhuang , Zhang Jiong , Hou Fei , Gao Zhijun , Wang Zengtang , Sui Wei
Published: December 2014

When the height of roller compacted concrete (RCC) specimen is less than 400 mm, the specimen size and crack depth ratio will affect the double-K fracture parameters. In this paper, two groups of RCC specimens with different specimen size and crack depth ratio were investigated and the wedge splitting method was employed. Double-K fracture parameters were calculated employing the double-K fracture theory of concrete. It is indicated that when the crack depth ratio, α, increased from 0.4 to 0.6, the unstable fracture toughness, KICun, increases, while the initial fracture toughness, KICini, decreases. The crack depth ratio, α, has a continuous effect on KICini, however the effect on KICun decreases with the increase of α. When the height of the specimen, h, is less than 300 mm, the effect of specimen size on KICun is significant, but it decreases when h is greater than 300 mm and less than 500 mm.
Comparison between Laboratory and Field Stiffness by Wave Measurements
Authors: Martins João , Gomes Correia A.
Published: December 2014

The present work aims to establish a relationship between field and laboratory moduli obtained from mechanical wave measurements. Spectral analysis of surface waves was performed on a clayey sand trial layer during tests in a full-scale trial. Laboratory triaxial tests involving S-wave measurements with bender elements and accelerometers were conducted on specimens under similar conditions, and the shear modulus was determined. Both laboratory and field methodologies for the determination of the shear modulus were based on S-wave propagation through the tested material; thus they involved similar stress and strain levels. A reasonable relationship was observed between field and laboratory moduli, taking into account field conditions (moisture content and void ratio) and stress state.
Field Response of High Speed Rail Box Tunnel During Horizontal Grouting
Authors: Ni James C. , Cheng Wen-Chieh
Published: December 2014

The construction of two bored tunnels passing underneath an existing high speed rail (HSR) box tunnel needed to traverse obliquely through the diaphragm wall originally used for excavation and lateral support during construction of the HSR box tunnel. An access lift shaft was constructed adjacent to the HSR box tunnel diaphragm wall to provide access for the horizontal grouting equipment used to modify the surrounding soil to have sufficient water tightness and shear strength for safe tunnel eye creation and removal of steel H-beams left within the soil mixing wall. The grout block behind the tunnel eye was constructed first, followed by a long distance (up to 52 m) horizontal grouting (LDHG) program to form the other grout block around the steel H-beams. Since the grouted area was confined by a box tunnel on top and diaphragm walls on both sides, inappropriate grouting pressure could cause significant vertical movement of the HSR box tunnel above and potentially endanger the safety of the HSR service within. The grouting program was adjusted in accordance to real time box tunnel motion as detected by electronic beam sensors along the side walls of the box tunnel. Our strategies for overcoming the challenges associated with long distance horizontal wash boring through diaphragm walls, scattered with steel H-beams, and accompanying grouting strategy will be presented in this paper. The vertical movement of the HSR box tunnel during the LDHG program was well controlled to less than 4 mm, while the maximum lateral displacement of the shaft diaphragm wall was maintained below 9 mm.
Mode II Brittle Fracture Assessment of Key-Hole Notches by Means of the Local Energy
Authors: Torabi A. R. , Campagnolo A. , Berto F.
Published: December 2014

Brittle fracture of key-hole notches under pure mode II loading is investigated both experimentally and theoretically. In the experimental part, a new version of the well-known Brazilian disk specimen containing a central dumbbell-shaped slit with two key-ends, called the Key-BD specimen, made of polymethyl-methacrylate (PMMA), is utilized to perform fracture experiments at room temperature for different notch lengths and various notch radii. In the theoretical part, the experimentally recorded fracture loads are predicted by means of the strain energy density (SED) averaged over a specified control volume, which embraces the notch edge. It is found that the SED criterion can successfully predict the test results.
Chromosome hydroxymethylation patterns in human zygotes and cleavage-stage embryos
Authors: Efimova Olga A , Pendina Anna A , Tikhonov Andrei V , Fedorova Irina D , Krapivin Mikhail I , Chiryaeva Olga G , Shilnikova Evgeniia M , Bogdanova Mariia A , Kogan Igor Yu , Kuznetzova Tatyana V , Gzgzyan Alexander M , Ailamazyan Edward K , Baranov Vladislav S
Published: December 2014

We report the sequential changes in 5-hydroxymethylcytosine (5hmC) patterns in the genome of human preimplantation embryos during DNA methylation reprogramming. We have studied chromosome hydroxymethylation and methylation patterns in triploid zygotes and blastomeres of cleavage-stage embryos. Using indirect immunofluorescence, we have analyzed the localization of 5hmC and its co-distribution with 5-methylcytosine (5mC) on the QFH-banded metaphase chromosomes. In zygotes, 5hmC accumulates in both parental chromosome sets, but hydroxymethylation is more intensive in the poorly methylated paternal set. In the maternal set, chromosomes are highly methylated, but contain little 5hmC. Hydroxymethylation is highly region specific in both parental chromosome sets: hydroxymethylated loci correspond to R-bands, but not G-bands, and have well-defined borders, which coincide with the R/G-band boundaries. The centromeric regions and heterochromatin at 1q12, 9q12, 16q11.2, and Yq12 contain little 5mC and no 5hmC. We hypothesize that 5hmC may mark structural/functional genome ‘units’ corresponding to chromosome bands in the newly formed zygotic genome. In addition, we suggest that the hydroxymethylation of R-bands in zygotes can be treated as a new characteristic distinguishing them from G-bands. At cleavages, chromosomes with asymmetrical hydroxymethylation of sister chromatids appear. They decrease in number during cleavages, whereas totally non-hydroxymethylated chromosomes become numerous. Taken together, our findings suggest that, in the zygotic genome, 5hmC is distributed selectively and its pattern is determined by both parental origin of chromosomes and type of chromosome bands – R, G, or C. At cleavages, chromosome hydroxymethylation pattern is dynamically changed due to passive and non-selective overall loss of 5hmC, which coincides with that of 5mC.
GATA4 knockdown in MA-10 Leydig cells identifies multiple target genes in the steroidogenic pathway
Authors: Bergeron Francis , Nadeau Gabriel , S Viger Robert
Published: December 2014

GATA4 is an essential transcription factor required for the initiation of genital ridge formation, for normal testicular and ovarian differentiation at the time of sex determination, and for male and female fertility in adulthood. In spite of its crucial roles, the genes and/or gene networks that are ultimately regulated by GATA4 in gonadal tissues remain to be fully understood. This is particularly true for the steroidogenic lineages such as Leydig cells of the testis where manyin vitro(promoter) studies have provided good circumstantial evidence that GATA4 is a key regulator of Leydig cell gene expression and steroidogenesis, but formal proof is still lacking. We therefore performed a microarray screening analysis of MA-10 Leydig cells in whichGata4expression was knocked down using an siRNA strategy. Analysis identified several GATA4-regulated pathways including cholesterol synthesis, cholesterol transport, and especially steroidogenesis. A decrease in GATA4 protein was associated with decreased expression of steroidogenic genes previously suspected to be GATA4 targets such asCyp11a1andStar.Gata4knockdown also led to an important decrease in other novel steroidogenic targets includingSrd5a1,Gsta3,Hsd3b1, andHsd3b6, as well as genes known to participate in cholesterol metabolism such asScarb1,Ldlr,Soat1,Scap, andCyp51. Consistent with the decreased expression of these genes, a reduction in GATA4 protein compromised the ability of MA-10 cells to produce steroids both basally and under hormone stimulation. These data therefore provide strong evidence that GATA4 is an essential transcription factor that sits atop of the Leydig cell steroidogenic program.
Cyclooxygenase and prostaglandins in somatic cell populations of the testis
Authors: Frungieri Mónica B , Calandra Ricardo S , Mayerhofer Artur , Matzkin María E
Published: December 2014

Prostaglandins (PGs) are synthesized through the action of the rate-limiting enzyme cyclooxygenase (COX) and further specific enzymes. The development ofCox-deficient mice in the 1990s gave insights into the reproductive roles of PGs. FemaleCox-knockout mice were subfertile or infertile. Interestingly, fertility was not affected in male mice deficient inCox, suggesting that PGs may not be critical for the functioning of the testis. However, this conclusion has recently been challenged by observations of important roles for PGs in both physiological and pathological processes in the testis. The two key somatic cell types in the testis, Leydig and Sertoli cells, express the inducible isoenzyme COX2 and produce PGs. Testicular COX2 expression in these somatic cells is regulated by hormonal input (FSH, prolactin (PRL), and testosterone) as well as by IL1β. PGs modulate steroidogenesis in Leydig cells and glucose uptake in Sertoli cells. Hence, the COX2/PG system in Leydig and Sertoli cells acts as a local modulator of testicular activity, and consequently may regulate spermatogenic efficiency. In addition to its expression in Leydig and Sertoli cells, COX2 has been detected in the seminiferous tubule wall, and in testicular macrophages and mast cells of infertile patients. These observations highlight the possible relevance of PGs in testicular inflammation associated with idiopathic infertility. Collectively, these data indicate that the COX2/PG system plays crucial roles not only in testicular physiology (i.e., development, steroidogenesis, and spermatogenesis), but more importantly in the pathogenesis or maintenance of infertility status in the male gonad. Further studies of these actions could lead to new therapeutic approaches to idiopathic male infertility.

Free German abstract

A German translation of this abstract is freely available athttp://www.reproduction-online.org/content/149/4/R169/suppl/DC1.

Free Spanish abstract

A Spanish translation of this abstract is freely available athttp://www.reproduction-online.org/content/149/4/R169/suppl/DC2.
Regulation of spermatogonial stem cell self-renewal and spermatocyte meiosis by Sertoli cell signaling
Authors: Chen Su-Ren , Liu Yi-Xun
Published: December 2014

Spermatogenesis is a continuous and productive process supported by the self-renewal and differentiation of spermatogonial stem cells (SSCs), which arise from undifferentiated precursors known as gonocytes and are strictly controlled in a special ‘niche’ microenvironment in the seminiferous tubules. Sertoli cells, the only somatic cell type in the tubules, directly interact with SSCs to control their proliferation and differentiation through the secretion of specific factors. Spermatocyte meiosis is another key step of spermatogenesis, which is regulated by Sertoli cells on the luminal side of the blood–testis barrier through paracrine signaling. In this review, we mainly focus on the role of Sertoli cells in the regulation of SSC self-renewal and spermatocyte meiosis, with particular emphasis on paracrine and endocrine-mediated signaling pathways. Sertoli cell growth factors, such as glial cell line-derived neurotrophic factor (GDNF) and fibroblast growth factor 2 (FGF2), as well as Sertoli cell transcription factors, such as ETS variant 5 (ERM; also known as ETV5), nociceptin, neuregulin 1 (NRG1), and androgen receptor (AR), have been identified as the most important upstream factors that regulate SSC self-renewal and spermatocyte meiosis. Other transcription factors and signaling pathways (GDNF–RET–GFRA1 signaling, FGF2–MAP2K1 signaling, CXCL12–CXCR4 signaling, CCL9–CCR1 signaling, FSH–nociceptin/OPRL1, retinoic acid/FSH–NRG/ERBB4, and AR/RB–ARID4A/ARID4B) are also addressed.
Investigation of the stallion sperm proteome by mass spectrometry
Authors: Swegen Aleona , Curry Benjamin J , Gibb Zamira , Lambourne Sarah R , Smith Nathan D , Aitken R John
Published: December 2014

Stallion spermatozoa continue to present scientific and clinical challenges with regard to the biological mechanisms responsible for their survival and function. In particular, deeper understanding of sperm energy metabolism, defence against oxidative damage and cell–cell interactions should improve fertility assessment and the application of advanced reproductive technologies in the equine species. In this study, we used highly sensitive LC–MS/MS technology and sequence database analysis to identify and characterise the proteome of Percoll-isolated ejaculated equine spermatozoa, with the aim of furthering our understanding of this cell's complex biological machinery. We were able to identify 9883 peptides comprising 1030 proteins, which were subsequently attributed to 975 gene products. Gene ontology analysis for molecular and cellular processes revealed new information about the metabolism, antioxidant defences and receptors of stallion spermatozoa. Mitochondrial proteins and those involved in catabolic processes constituted dominant categories. Several enzymes specific to β-oxidation of fatty acids were identified, and further experiments were carried out to ascertain their functional significance. Inhibition of carnitine palmitoyl transferase 1, a rate-limiting enzyme of β-oxidation, reduced motility parameters, indicating that β-oxidation contributes to maintenance of motility in stallion spermatozoa.
Effects of maternal n-3 fatty acid supplementation on placental cytokines, pro-resolving lipid mediators and their precursors
Authors: Keelan Jeffrey A , Mas Emilie , D'Vaz Nina , Dunstan Janet A , Li Shaofu , Barden Anne E , Mark Peter J , Waddell Brendan J , Prescott Susan L , Mori Trevor A
Published: December 2014

The aim of this study was to determine whether supplementation with fish oil-derived n-3 polyunsaturated fatty acids (n-3 PUFA) during pregnancy modifies placental PUFA composition, the accumulation of specialised pro-resolving lipid mediators (SPMs, specifically resolvins (Rv), protectins (PD) and upstream precursors) and inflammatory gene expression. Placentas were collected from women (n=51) enrolled in a randomised, placebo controlled trial of n-3 PUFA supplementation from 20-week gestation. Lipids were extracted for fatty acid analysis and SPMs were quantitated by mass spectrometry. Gene expression was determined by qRT-PCR. Using multiple regression analysis, data were correlated for placental n-3 PUFA and SPM levels with PUFA levels in maternal and cord blood erythrocytes. Supplementation with n-3 PUFAs increased placental docosahexaenoic acid (DHA) levels, but not eicosapentaenoic acid (EPA) levels (P<0.05), and increased the levels of the SPM precursors 18-hydroxyeicosapentaenoic acid and 17-hydroxydocosahexaenoic acid (17-HDHA) by two- to threefold (P<0.0005). RvD1, 17R-RvD1, RvD2 and PD1 were detectable in all placentas, but concentrations were not significantly increased by n-3 PUFA supplementation. Placental DHA levels were positively associated with maternal and cord DHA levels (P<0.005), and with placental 17-HDHA concentrations (P<0.0001). Placental mRNA expression ofPTGS2,IL1β,IL6andIL10was unaffected by n-3 PUFA supplementation, butTNFαexpression was increased by 14-fold (P<0.05). We conclude that n-3 PUFA supplementation in pregnancy i) enhances placental accumulation of DHA and SPM precursors, ii) does not alter placental EPA levels, and iii) has no stimulatory effects on inflammatory gene expression. Further studies are required to ascertain the biological significance of SPMs in the placenta and the potential immunomodulatory effects of elevating placental SPM levels.
In vivo effect of insulin on the hormone production of immune cells in mice — Gender differences
Authors: Pállinger Éva , Csaba György
Published: December 2014

The immune cells of rat and man synthesize, store and secrete hormones, characteristic to the endocrine glands. In the present experiments female and male CD1 mice were treated with 10 IU/kg insulin sc. (the controls with normal saline) and after 30 min peritoneal fluid was gained. The cells of the peritoneal fluid (lymphocytes and the monocyte-granulocyte group) were studied by immunocytochemical flow-cytometry to adrenocorticotropic hormone (ACTH), triiodothyronine (T3), histamine and serotonin content. In the female mice each hormone level was significantly lower in the insulin-treated animals, except histamine in the monocyte-granulocyte group. In the insulin-treated male animals, the hormone levels were similar to the control. The results 1) support the previously hypothesized hormonal network in the immune system, 2) justify that the insulin effect is not species dependent and 3) call attention to the sex, species and organ differences in the response.
Virulence factors, antimicrobial susceptibility and molecular characterization of Streptococcus agalactiae isolated from pregnant women
Authors: Beigverdi Reza , Jabalameli Fereshteh , Mirsalehian Akbar , Hantoushzadeh Sedigheh , Boroumandi Shahram , Taherikalani Morovat , Emaneini Mohammad
Published: December 2014

Forty-one Streptococcus agalactiae isolates collected from pregnant women at 35–37 weeks of gestation were analysed for their capsular types, antimicrobial resistance determinants, distribution of virulence factors and genetic relatedness using PCR and multiplex PCR. Capsular type III was predominant (65.8%), followed by capsular type II (14.6%), Ib (7.3%), and V(4.9%). All isolates were susceptible to penicillin, vancomycin, linezolid and quinupristin-dalfopristin. Resistance to tetracycline, erythromycin and clindamycin were found in 97.6%, 24.4%, and 14.6% of isolates, respectively. The most common antimicrobial resistance gene was tetM found in 97.6% of the isolates followed by ermTR and ermB found in 12% and 7.3% of isolates, respectively. The most common virulence gene was hly (100%), followed by scpB (97.6%), bca (97.6%), rib (53.65%) and bac (4.9%). The insertion sequence IS1548 was found in 63.4% of isolates. By multi locus variable number of tandem repeat analysis (MLVA) typing, 30 different allelic profiles or MLVA types (MTs) were identified. The most frequent was the MT1 (5/41, 12.2%) and followed by MT2 (4/41, 9.75%). Our data revealed that population structure of these isolates is highly diverse and indicates different MLVA types.
Antimicrobial susceptibility and genotyping analysis of Hungarian Neisseria gonorrhoeae strains in 2013
Authors: Nemes-Nikodém Éva , Brunner Alexandra , Pintér Dóra , Mihalik Noémi , Lengyel György , Marschalkó Márta , Kárpáti Sarolta , Szabó Dóra , Ostorházi Eszter
Published: December 2014

Emergence and spread of antimicrobial resistance inNeisseria gonorrhoeaeis a major public health concern worldwide. The current study aims to determine the antimicrobial resistance inN. gonorrhoeaeand associated molecular typing to enhance gonococcal antimicrobial surveillance in Hungary. In the NationalN. gonorrhoeaeReference Laboratory of Hungary 187N. gonorrhoeaeinfections were detected in 2013, antibiograms were determined for all the isolated strains, and 52 (one index strain from every sexually contact related group) of them were also analysed by theN. gonorrhoeaemulti-antigen sequence typing (NG-MAST) method. Twenty-two different NG-MAST sequence types (STs) were identified, of which 8 STs had not been previously described. In Hungary, the highly diversified gonococcal population displayed high resistance to penicillin, ciprofloxacin and tetracycline (the antimicrobials previously recommended for gonorrhoea treatment). Resistance to the currently recommended extended spectrum cephalosporines were rare: only two of the expected strains, an ST 1407 and an ST 210, had cefixime MIC above the resistance breakpoint. By the revision of our National Treatment Guideline, it must be considered, that the azithromycin resistance is about 60% among the four most frequently isolated STs in Hungary.
Thiolated pyrimidine nucleotides may interfere thiol groups concentrated at lipid rafts of HIV-1 infected cells
Authors: Kanizsai Szilvia , Ongrádi Joseph , Aradi János , Nagy Károly
Published: December 2014

Upon HIV infection, cells become activated and cell surface thiols are present in increased number. Earlier we demonstrated in vitro anti-HIV effect of thiolated pyrimidine nucleotide UD29, which interferes thiol function. To further analyse the redox processes required for HIV-1 entry and infection, toxicity assays were performed using HIV-1 infected monolayer HeLaCD4-LTR/ β-gal cells and suspension H9 T cells treated with several thiolated nucleotide derivatives of UD29. Selective cytotoxicity of thiolated pyrimidines on HIV-1 infected cells were observed. Results indicate that thiolated pyrimidine derivates may interfere with -SH (thiol) groups concentrated in lipid rafts of cell membrane and interacts HIV-1 infected (activated) cells resulting in a selective cytotoxicity of HIV-1 infected cells, and reducing HIV-1 entry.
A suggested differential protection scheme for power transformer
Authors: Ahmed E. , El-Sehiemy R.
Published: December 2014

This paper integrates a Real Power Differential Scheme (RPDS) for power transformer protection. The suggested RPDS for power transformer computes the active power loci during normal operation, switching, normal, and internal, involves turn to turn, and external faults at varied load angles. The proposed RPDS concept is based on monitoring and comparing the transformers primary and secondary active and reactive powers. The dynamic response of the proposed RPDS is tested 300 MVA, 220/66 kV, Y/Δ transformer. Furthermore, the suggested scheme is simulated with the use of Matlab/Simulink then tested for various fault and switching conditions. Moreover, the RPDS is checked for inter turn fault conditions at primary and secondary sides. The evaluation of the suggested scheme confirms the superiority of the proposed scheme to distinguish internal and external faults as well as magnetizing inrush currents with good selectivity, high speed, sensitivity, stability limits and high accuracy response of the power differential scheme. Finally, the suggested scheme is able to detect correctly the turn to turn faults for wide range of fault resistances but fails at very low values.
Examining the significance of market research in the case of start-ups
Authors: Matkó A. , Szűcs E. , Takács T. , Kovács S.
Published: December 2014

Today, companies have to face new challanges because of the globalization, new technologies, globalization of markets and increasing competition. In this accelerated world, it is essential that the companies adapt to the market, which is only available through the necessary information. The importance of market research is undoubted. In our study we would like to prove that in case of a beginner company — in this case a confectionery — it is important to perform a market research like for a company in any other segment. To perform it, the qualitative market research methods were used. Our questionnaire examines several aspects in order to provide an indication of the company’s founding.
Structural performance of steel fibre reinforced concrete — Part III. Behaviour in tension
Authors: Kovács I.
Published: December 2014

The present paper of a series deals with the experimental characterisation of tensile splitting strength and compressive behaviour of different structural concrete containing different volume of steel fibre reinforcement (0 V%, 0.5 V%, 1.0 V%, 75 kg/m3, 150 kg/m3) and different configuration of steel fibres (crimped, hooked-end). Tensile splitting tests were carried out on standard cylinder (∅ = 150 mm, l = 300 mm) specimens (so-called Brazilian test) considering random fibre orientation. Since the fibre orientation may significantly affect the tensile behaviour test series were also performed on cross-section (100 mm × 100 mm) of steel fibre reinforced concrete beams (100 mm × 100 mm × 240 mm) sawn out of steel fibre reinforced slab elements. Taken as a whole behaviour of steel fibre reinforced concrete was examined in tension taking into consideration different experimental parameters such as fibre content, type of fibres, fibre configuration, fibre orientation, size of specimens (size effect) and concrete mixture.
Structural performance of steel fibre reinforced concrete — Part IV. Toughness properties
Authors: Kovács I.
Published: December 2014

The present paper of a series deals with the experimental characterisation of flexural toughness properties of structural concrete containing different volume of hooked-end steel fibre reinforcement (75 kg/m3, 150 kg/m3). Third-point flexural tests were carried out on steel fibre reinforced concrete beams having a cross-section of 80 mm × 85 mm with the span of 765 mm, hence the shear span to depth ratio was 3. Beams were sawn out of steel fibre reinforced slab elements (see Part I) in order to take into consideration the introduced privilege fibre orientation (I and II) and the position of the beam (Ba-a, Ba-b, Ba-c) before sawing (see Part I). Flexural toughness properties were determined considering different standard specifications, namely the method of the ASTM (American Standards for Testing Materials), the process of the JSCE (Japan Society of Civil Engineering), and the final proposal of Banthia and Trottier for the post cracking strength. Consequently, behaviour of steel fibre reinforced concrete was examined in bending taking into consideration different experimental parameters such as fibre content, concrete mix proportions, fibre orientation, positions of test specimens in the formwork, while experimental constants were the size of specimens, the type of fibre used and the test set-up and test arrangement.
Structural analysis and its statistical evaluation of a closed-cell metal foam
Authors: Mankovits T. , Budai I. , Balogh G. , Gábora A. , Kozma I. , Varga T. , Manó S. , Kocsis I.
Published: December 2014

The development of an efficient procedure for 3d modeling and finite element simulation of metal foams is one of the greatest challenges for engineer researchers nowadays. Creating 3d CAD model is alone a demanding engineering task due to its extremely complex geometry, and the proper finite element analysis process is still in the center of the research. The increasingly widespread application of the metal foams, e.g. in vehicle and medical industry, requires this knowledge in the design phase. A closed-cell metal foam is studied using different analyzing methods where the aim is to collect information about the composition and geometry (structure) that is satisfactory for the later research. Using statistical methods microscopic, X-ray and surface analyzing studies on the specimens produced according to the concerning standard are evaluated. The main goal of this part of the project is to obtain structural information and to determine the homogeneity or the in-homogeneity property of the metal foam specimens taken from different locations.
Identification of crack characteristics in beams by using modal frequencies and inverse problem
Authors: Teidj S. , Khamlichi A. , Driouach A. , Limam A.
Published: December 2014

Detection of cracks in mechanical components as early as possible enables monitoring structural health and scheduling efficiently the maintenance tasks such as replacing the critical parts just in time. Vibration analysis based techniques for crack detection have been largely considered in the framework of beam-like structures. This methodology relies essentially on the observed changes of beam frequencies and mode shapes induced by the presence of damage. In the present work, using an explicit analytical model assessing the effect of a crack on beam strain energy, the beam first resonance frequencies as they depend on a single crack defect characteristics were evaluated. The crack equations were obtained by means of fracture mechanics approach. Variations of the first beam frequencies and modes shapes were then related explicitly to the location and depth of the crack. Measuring the beam frequency changes and monitoring their variations can be used to perform identification of the crack defect parameters by solution of an inverse problem.
Detection of delamination in composites by using electromagnetic penetrating radar
Authors: Mechbal Z. , Khamlichi A.
Published: December 2014

Composites made from E-glass/epoxy or aramid/epoxy are frequently used in aircraft and aerospace industries. These materials are prone to suffer from the presence of delamination, which can reduce severely the performance of aircrafts and even threaten their safety. Since electric conductivity of these composites is rather small, they can propagate electromagnetic waves. Detection of delamination damage can then be monitored by using an electromagnetic penetrating radar scanner, which consists of emitting waves having the form of short time pulses that are centered on a given work frequency. While propagating, these waves undergo partial reflection when running into an obstacle or a material discontinuity. Habitually, the radar is moved at constant speed along a straight path and the reflected signal is processed as a radargram that gives the reflected energy as function of the two-way time and the antenna position.In this work, modeling of electromagnetic wave propagation in composites made from E-glass/epoxy was performed analytically. The electromagnetic wave reflection from a delamination defect was analyzed as function of key intervening factors which include the defect extent and depth, as well as the work frequency. Various simulations were performed and the obtained results have enabled to correlate the reflection pattern image features to the actual delamination defect characteristics which can provide quantification of delamination.
Intelligent building development and LabView-based modelling of a net zero-energy strategy
Authors: Szász Cs.
Published: December 2014

The paper presents an intelligent building (IB) development strategy emphasizing the locally available non-polluting renewable energy resources utilization. Considering the immense complexity of the topic, the implementation strategy of the main energy-flow processes is unfolded, using the net zero-energy building concept (NZEB). Noticeably, in the first research steps the mathematical background of the considered NZEB strategy has been developed and presented. Then careful LabView software-based simulations prove that the adopted strategy is feasible for implementation. The result of the above mentioned research efforts is a set of powerful and versatile software toolkits well suitable to model and simulate complex heating, ventilation and air-conditioning processes and to perform energy balance performance evaluations. Besides the elaborated mathematical models, concrete software implementation examples and measurement data also is provided in the paper. Finally, the proposed original models offer a feasible solution for future developments and research in NZEB applications modelling and simulation purposes.
Relationships between macrosynoptic weather types and development of the thermal excess in suburban areas in Debrecen, Hungary
Authors: Szegedi S. , Lázár I. , Tóth T.
Published: December 2014

Impacts of macrosynoptic weather patterns on the development of the thermal excess in suburban areas of Debrecen are examined in this paper. Temperature datasets have been recorded at two heights by three automatic weather stations mounted in Debrecen (east Hungary) and a small settlement in its vicinity. An additional automatic weather station is used as a reference station outside Debrecen. Urban heat island (UHI) intensities have been calculated from the raw datasets. Impacts of synoptic conditions have been analyzed on the base of Péczely’s macrosynoptic types. It has been found that anticyclone types are more favorable from the aspect of UHI development, while cyclone types, especially the passage of warm fronts can effectively hinder the formation of strong heat islands in Debrecen.
New technique for intestinal lengthening – from the idea to the clinical application
Authors: Cserni Tamás , Varga Garbriella , Érces Dániel , Kaszaki József , Biszku Beáta , Guthy Ildikó , László Ágnes , Dicső Ferenc , Bianchi Adrian , Morabito Antonino , Rákóczy György
Published: December 2014

Bevezetés: Súlyos rövidbél-szindrómában, a természetes adaptáció következtében, a megmaradt vékonybél annyira kitágul, hogy a béltartalmat nem képes továbbítani, ez stasishoz, bacterialis translocatióhoz, majd sepsishez vezethet. A passzázs javítására jelenleg alkalmazott műtétek közül a Bianchi-műtét igen bonyolult, a serial transverse enteroplasty (STEP) lényegesen egyszerűbb, de az izomrostok orientációját drámaian megváltoztatva afiziológiás állapotot teremt. Célunk egy új, egyszerű és kevéssé kockázatos bélhosszabbító műtéti technika kifejlesztése volt, amely nem változtatja meg jelentősen a bél mikroszkópos anatómiáját. Anyag és módszer: Az ötlet a bél spirális vonal mentén történő incisióján és kisebb kaliberen történő retubularisatióján alapul. A műtétet spiral intestinal lengthening and tailoringnek (SILT) neveztük el. Elsőként a műtét kivitelezhetőségét és az izomrostok orientációjára gyakorolt hatását vizsgáltuk bélszimulátoron és sertésbélen. Az intramuralis keringésváltozásokat in vivo mikroszkópia segítségével elemeztük, majd műtétet túlélő sertésmodellen (n = 6) teszteltük, csak ezek után került sor a klinikai alkalmazásra. Eredmények: A SILT könnyen kivitelezhetőnek bizonyult, az izomrostok orientációja nem változott lényegesen. A műtét nem okozott kritikus változást a bélfal keringésében, és amennyiben a lumen szűkítése nem haladta meg a 75%-ot, nem észleltünk sebészi komplikációt vagy krónikus szöveti ischaemiát sem. Az első klinikai alkalmazás is sikeres volt. Következtetés: A SILT-műtét nem változtatja meg a bél izomstruktúráját, biztonságos és ajánlható módszer a bélhosszabbításra.