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Search Results: 1 - 10 of 1442 matches for " Anja Weise "
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Further delineation of complex chromosomal rearrangements in fertile male using multicolor banding
Nilüfer Karadeniz, Kristin Mrasek, Anja Weise
Molecular Cytogenetics , 2008, DOI: 10.1186/1755-8166-1-17
Abstract: Cytogenetic studies using high resolution banding of the proband necessitated further delineation of the breakpoints because of their uncertainty: 46,XY,t(1;4;2)(p21~31;q31.3;q31). After using high resolution MCB based on microdissection derived region-specific libraries, the exact nature of chromosomal rearrangements for chromosomes 1, 2 and 4 were revealed and these breakpoints were located on 1p31.1, 1q24.3 and 4q31.3 giving rise to a balanced situation.Further delineations are certainly required to provide detailed information about the relationship between balanced CCRs and their phenotypes in order to offer proper counseling to the families concerned. Carriers must be investigated with high resolution banding and molecular cytogenetic techniques to determine the exact locations of the breakpoints. High resolution MCB is an alternative and an efficient method to other FISH based chromosome banding techniques and can serve in clarifying the nature of CCR.Structural chromosomal abnormalities are estimated to occur in around 0.5% of newborn infants, using moderate level of resolution in conventional cytogenetic analysis [1]. Complex chromosomal rearrangements (CCRs) are defined as structural chromosomal rearrangements with at least three breakpoints and exchange of genetic material between two or more chromosomes. It is therefore not surprising to see CCR rarely in constitutional karyotypes. Moreover, some CCRs cannot be interpreted with standard cytogenetic methods at all [2]. Complex chromosomal rearrangements are extremely rare but are often associated with mental retardation, congenital abnormalities, recurrent abortions and infertility [3]. More than 130 constitutional CCRs have been documented so far [4]. 12 of these were related with fertile men including the case we present [5]. Providing genetic counseling for CCRs is very important and this can be offered before or after pregnancy as well as at the time of prenatal diagnosis [6].Since the introduction of
Volatile organic compounds produced by the phytopathogenic bacterium Xanthomonas campestris pv. vesicatoria 85-10
Teresa Weise,Marco Kai,Anja Gummesson,Armin Troeger
Beilstein Journal of Organic Chemistry , 2012, DOI: 10.3762/bjoc.8.65
Abstract: Xanthomonas campestris is a phytopathogenic bacterium and causes many diseases of agricultural relevance. Volatiles were shown to be important in inter- and intraorganismic attraction and defense reactions. Recently it became apparent that also bacteria emit a plethora of volatiles, which influence other organisms such as invertebrates, plants and fungi. As a first step to study volatile-based bacterial–plant interactions, the emission profile of Xanthomonas c. pv. vesicatoria 85-10 was determined by using GC/MS and PTR–MS techniques. More than 50 compounds were emitted by this species, the majority comprising ketones and methylketones. The structure of the dominant compound, 10-methylundecan-2-one, was assigned on the basis of its analytical data, obtained by GC/MS and verified by comparison of these data with those of a synthetic reference sample. Application of commercially available decan-2-one, undecan-2-one, dodecan-2-one, and the newly synthesized 10-methylundecan-2-one in bi-partite Petri dish bioassays revealed growth promotions in low quantities (0.01 to 10 μmol), whereas decan-2-one at 100 μmol caused growth inhibitions of the fungus Rhizoctonia solani. Volatile emission profiles of the bacteria were different for growth on media (nutrient broth) with or without glucose.
The hierarchically organized splitting of chromosomal bands for all human chromosomes
Nadezda Kosyakova, Anja Weise, Kristin Mrasek, Uwe Claussen, Thomas Liehr, Heike Nelle
Molecular Cytogenetics , 2009, DOI: 10.1186/1755-8166-2-4
Abstract: Here we present for the first time the hierarchically organized splitting of chromosomal bands in their sub-bands for all human chromosomes. To do this, array-proved multicolor banding (aMCB) probe-sets for all human chromosomes were applied to normal metaphase spreads of three different G-band levels. We confirmed for all chromosomes to be a general principle that only Giemsa-dark bands split into dark and light sub-bands, as we demonstrated previously by chromosome stretching. Thus, the biological band splitting is in > 50% of the sub-bands different than implemented by the ISCN nomenclature suggesting also a splitting of G-light bands. Locus-specific probes exemplary confirmed the results of MCB.Overall, the present study enables a better understanding of chromosome architecture. The observed difference of biological and ISCN band-splitting may be an explanation why mapping data from human genome project do not always fit the cytogenetic mapping.The biological nature of hierarchically organized splitting of bands of human chromosomes remained an enigma since the first banding methods were described in 1970 and 1971. The technique introduced by Lore Zech in Caspersson's laboratory involved quinacrine mustard (Q-banding) and fluorescence microscopy [1], while other used Giemsa (G-banding) [2,3]. Though several methods producing chromosome bands were developed later, G-banding became the one most widely used. A uniform system of human chromosomal nomenclature, which allowed to design not only individual chromosomes but also chromosome regions and bands, was proposed for the first time in 1971 at the Fourth International Congress of Human Genetics in Paris [4], later it developed into the document entitled "An International System for Human Cytogenetic Nomenclature", the last edition of which was published in 2005 [5]. Although recently evolved molecular cytogenetic techniques [6-8] and array-CGH [9] allow precise characterization of chromosomal abnormalities, analys
Position of chromosomes 18, 19, 21 and 22 in 3D-preserved interphase nuclei of human and gorilla and white hand gibbon
Marina Manvelyan, Friederike Hunstig, Kristin Mrasek, Samarth Bhatt, Franck Pellestor, Anja Weise, Thomas Liehr
Molecular Cytogenetics , 2008, DOI: 10.1186/1755-8166-1-9
Abstract: Here for the first time a combination of multicolor banding (MCB) and three-dimensional analysis of interphase cells was used to characterize the position and orientation of human chromosomes #18, #19, #21 and #22 and their homologues in primate B-lymphocytic cells. In general, our data is in concordance with previous studies. The position of the four studied human chromosomes and their homologues were conserved during primate evolution. However, comparison of interphase architecture in human B-lymphocytic cells and sperm revealed differences of localization of acrocentric chromosomes. The latter might be related to the fact that the nucleolus organizing region is not active in sperm.Studies in different tissue types may characterize more – potentially biologically relevant differences in nuclear architecture.In the interphase nucleus, chromosomes are located in specific regions, which are called 'chromosome territories' [1-3]. Recently, own multicolor banding (MCB) based studies showed, that the chromosome shape is not lost in the interphase nucleus and one can even identify interphase chromosomes instead of only chromosome territory [4,5].Both, chromosome size and gene density are discussed to have an important impact on the nuclear position of chromosomes. Small chromosomes preferentially locate close to the center of the nucleus, while large chromosomes can be found in the nuclear periphery of human fibroblasts [6,7]. On the other hand, Croft et al. (1999) [8] demonstrated a gene density-correlated radial arrangement of chromosomes in nucleus. Mainly gene-dense and early replicating chromatin, including the small human chromosome #19 with only 63 megabasepair (Mbp) in size but 27,9 genes/Mbp, can be found in the central part of the nucleus, while gene-poor and later replicating chromatin, like the human chromosome #18 (HSA #18) with a similar size like HSA #19 (77 Mbp and 8,7 genes/Mbp) is located in nuclear periphery [8]. This nuclear topological arrangement wa
Exchange bias effect in martensitic epitaxial Ni-Mn-Sn thin films applied to pin CoFeB/MgO/CoFeB magnetic tunnel junctions
Niclas Teichert,Alexander Boehnke,Anna Behler,Bruno Weise,Anja Waske,Andreas Hütten
Physics , 2015, DOI: 10.1063/1.4921080
Abstract: The exchange bias effect is commonly used to shift the coercive field of a ferromagnet. This technique is crucial for the use of magnetic tunnel junctions as logic or memory devices. Therefore, an independent switching of the two ferromagnetic electrodes is necessary to guarantee a reliable readout. Here, we demonstrate that the intrinsic exchange bias effect of Ni-Mn-Sn can be used to apply a unidirectional anisotropy to magnetic tunnel junctions. For this, we use epitaxial Ni-Mn-Sn films as pinning layers for microfabricated CoFeB/MgO/CoFeB magnetic tunnel junctions. We compare the exchange bias field ($H_{\text{EB}}$) measured after field cooling in $-10$\,kOe external field by magnetization measurements with $H_{\text{EB}}$ obtained from tunnel magnetoresistance measurements. Consistent for both methods we find an exchange bias of about $H_{\text{EB}}=130$\,Oe at 10\,K, which decreases with increasing temperature and vanishes above 70\,K.
Transcriptome and proteome analysis of tyrosine kinase inhibitor treated canine mast cell tumour cells identifies potentially kit signaling-dependent genes
Robert Klopfleisch, Anja Meyer, Patricia Schlieben, Angelika Bondzio, Chris Weise, Dido Lenze, Michael Hummel, Ralf Einspanier, Achim D Gruber
BMC Veterinary Research , 2012, DOI: 10.1186/1746-6148-8-96
Abstract: Transcriptome analysis of the canine mast cell tumour cell line C2 treated for up to 72 hours with the tyrosine kinase inhibitor masitinib identified significant changes in the expression levels of approximately 3500 genes or 16% of the canine genome. Approximately 40% of these genes had increased mRNA expression levels including genes associated with the pro-proliferative pathways of B- and T-cell receptors, chemokine receptors, steroid hormone receptors and EPO-, RAS and MAP kinase signaling. Proteome analysis of C2 cells treated for 72 hours identified 24 proteins with changed expression levels, most of which being involved in gene transcription, e.g. EIA3, EIA4, TARDBP, protein folding, e.g. HSP90, UCHL3, PDIA3 and protection from oxidative stress, GSTT3, SELENBP1.Transcriptome and proteome analysis of neoplastic canine mast cells treated with masitinib confirmed the strong important and complex role of KIT in these cells. Approximately 16% of the total canine genome and thus the majority of the active genes were significantly transcriptionally regulated. Most of these changes were associated with reduced proliferation and metabolism of treated cells. Interestingly, several pro-proliferative pathways were up-regulated, which may represent attempts of masitinib treated cells to activate alternative pro-proliferative pathways. These pathways may contain hypothetical targets for a combination therapy with masitinib to further improve its therapeutic effect.Canine mast cell tumours (MCT) are currently treated with one or a combination of four different therapeutic approaches: surgical, radiation, classical chemotherapy and the recently introduced tyrosine kinase inhibitors (TKI) [1-3]. The latter mainly act by inhibiting the stem cell factor receptor KIT, the activation of which is one of the most important proliferation stimuli of normal and neoplastic mast cells [1,4].KIT is constitutively expressed on normal and neoplastic canine mast cells [5]. Due to its centra
Chromosome distribution in human sperm – a 3D multicolor banding-study
Marina Manvelyan, Friederike Hunstig, Samarth Bhatt, Kristin Mrasek, Franck Pellestor, Anja Weise, Isabella Simonyan, Rouben Aroutiounian, Thomas Liehr
Molecular Cytogenetics , 2008, DOI: 10.1186/1755-8166-1-25
Abstract: Here for the first time a combination of multicolor banding (MCB) and three-dimensional analysis of interphase cells was used to characterize the position and orientation of all human chromosomes in sperm cells of a healthy donor. The interphase nuclei of human sperm are organized in a non-random way, driven by the gene density and chromosome size.Here we present the first comprehensive results on the nuclear architecture of normal human sperm. Future studies in this tissue type, e.g. also in male patients with unexplained fertility problems, may characterize yet unknown mechanisms of infertility.Interphase chromosome organization and nuclear architecture are already being investigated for a long time [1-3]. Chromosomes have been demonstrated to be located in specific regions in the interphase nucleus. These were called 'chromosome territories' [4-7]. However, our own multicolor banding (MCB) based studies [8] showed, that the chromosome shape is not lost in the interphase nucleus and one can even identify interphase chromosomes instead of only chromosome territory [9-11]. MCB is the only approach available at present that provides the possibility of characterizing the chromosomal integrity of arbitrary interphase cell populations [12,13]. It is still a matter of discussion what influences more the nuclear position of chromosomes: chromosome size or gene density. It has been repeatedly shown that small chromosomes preferentially locate close to the center of the nucleus, while large chromosomes can be found in the nuclear periphery of human fibroblasts [11-15]. Nonetheless, also evidence for a gene density-correlated radial arrangement of chromosomes in the nucleus was provided [16]. Human chromosome #19, which is gene-dense and early replicating shows a localization in the central part, for the approximately same sized chromosome 18 a localization in the peripheral part of the nucleus was repeatedly proven. As the latter is gene-poorer and comprises late-replicatin
Molecular cytogenetic characterisation of a mosaic add(12)(p13.3) with an inv dup(3)(q26.31 → qter) detected in an autistic boy
Isabel M Carreira, Joana B Melo, Carlos Rodrigues, Liesbeth Backx, Joris Vermeesch, Anja Weise, Nadezda Kosyakova, Guiomar Oliveira, Eunice Matoso
Molecular Cytogenetics , 2009, DOI: 10.1186/1755-8166-2-16
Abstract: We present the results of the molecular cytogenetic characterization of an unbalanced mosaic karyotype consisting of mos 46,XY,add(12)(p13.3) [56]/46,XY [44] in a previously described 11 years old autistic boy, re-evaluated at adult age. The employment of fluorescence in situ hybridization (FISH) and multicolor banding (MCB) techniques identified the extra material on 12p to be derived from chromosome 3, defining the additional material on 12p as an inv dup(3)(qter → q26.3::q26.3 → qter). Subsequently, array-based comparative genomic hybridization (aCGH) confirmed the breakpoint at 3q26.31, defining the extra material with a length of 24.92 Mb to be between 174.37 and 199.29 Mb.This is the thirteenth reported case of inversion-duplication 3q, being the first one described as an inv dup translocated onto a non-homologous chromosome. The mosaic terminal inv dup(3q) observed could be the result of two proposed alternative mechanisms. The most striking feature of this case is the autistic behavior of the proband, a characteristic not shared by any other patient with tetrasomy for 3q26.31 → 3qter. The present work further illustrates the advantages of the use of an integrative cytogenetic strategy, composed both by conventional and molecular techniques, on providing powerful information for an accurate diagnosis. This report also highlights a chromosome region potentially involved in autistic disorders.According to the orientation of the duplicated segment, duplications may be classified either as tandem or inverted, being the last usually associated with deletion of the distal region of the duplicated chromosome [1]. The best studied cases of inverted duplications (inv dup) are the inv dup(8p) [2,3] and bisatellited inv dup(15) [4], which are usually non-mosaic. In contrast, mosaic inverted duplications are derived from different post-zygotic mechanisms for which various possible origins have been proposed [5-7]. There is also a particular subset of inv dup in which the
Clinically abnormal case with paternally derived partial trisomy 8p23.3 to 8p12 including maternal isodisomy of 8p23.3: a case report
Dilek Aktas, Anja Weise, Eda Utine, Dursun Alehan, Kristin Mrasek, Ferdinand von Eggeling, Heike Thieme, Ergul Tuncbilek, Thomas Liehr
Molecular Cytogenetics , 2009, DOI: 10.1186/1755-8166-2-14
Abstract: Chromosome analysis, multicolor banding analysis (MCB), extensive fluorescence in situ hybridization (FISH) analysis and microsatellite analysis were performed.The karyotype was characterized in detail by multicolor banding (MCB), subtelomeric and centromere-near probes as 46,XY,dup(8)(pter->p23.3::p12->p23.3::p23.3->qter). Additionally, microsatellite analysis revealed the paternal origin of the duplication and gave hints for a mitotic recombination involving about 6 MB in 8p23.3.A comprehensive analysis of the derivative chromosome 8 suggested a previously unreported mechanism of formation, which included an early mitotic aberration leading to maternal isodisomy, followed by an inverted duplication of the 8p12p23.3 region.To date, a number of patients with inverted duplication of 8p have been identified through cytogenetic analysis [1-7] and different breakpoints related to 8p have been reported [4]. The distal breakpoint was predominantly in 8p23 and was found in combination with various proximal breakpoints (centromere, p11 and p12), but predominantly within 8p11.An inverted duplication of 8p is associated with mental retardation, distinct facial anomalies, agenesis of corpus callosum and hypotonia. Although less common, congenital heart defects, coloboma, scoliosis and seizures are noted.We report another patient with a complex rearrangement leading to an inverted duplication of 8p23.3 to 8p12. Phenotypic findings in our patient and previously reported chromosome 8p inverted duplications are reviewed and several important features are highlighted.The male infant was the second child born to a non-consanguineous couple. Following a normal gestation and delivery, the boy was born at 40-weeks of gestation with a birth weight of 3.2 kg. There were no neonatal problems or feeding difficulty.At 15 months of age, his weight was 11.3 kg (10th–25th centiles), length was 87 cm (90th–95th centiles), and head circumference was 48 cm (10th–25th centiles). He was evaluated f
University Teachers: Coping with Sociocultural Diversity. A Study about Critical Incidents between Hegemonic and Subaltern Cultures  [PDF]
Crista Weise, Carles Monereo
Creative Education (CE) , 2018, DOI: 10.4236/ce.2018.96071
Abstract: This article aims to identify and characterise the critical incidents (CI) that occur most frequently at university level in highly diverse sociocultural contexts. Intercultural relations will be analysed within the framework of hegemony and resistance between Western culture, which is inherent to university settings, and the non-Western mixed traits present in the student body. The relationship between different CIs will be examined, as will be the various issues associated with them according to teachers’ perceptions. For this qualitative study, 23 teachers from two Bolivian universities were interviewed. The teachers reported 9 types of CIs linked to sociocultural diversity. The results indicate that CIs are usually the outcome of cultural clashes between the institutional and teachers’ culture and the students’ culture, with the three most frequent CIs related to the use of the vehicular language, expression and communication; different thinking processes and the relationship between students. As a result, we propose a typology and a scheme for classification and interpretation of CIs linked to cultural diversity with the objective of advancing university teacher training.
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