Science.gov

Sample records for cytogenetic repair efficiency

  1. Altered Gene Expressions and Cytogenetic Repair Efficiency in Cells with Suppressed Expression of XPA after Proton Exposure

    NASA Technical Reports Server (NTRS)

    Zhang, Ye; Rohde, Larry H.; Gridley, Daila S.; Mehta, Satish K.; Pierson, Duane L.; Wu, Honglu

    2009-01-01

    Cellular responses to damages from ionizing radiation (IR) exposure are influenced not only by the genes involved in DNA double strand break (DSB) repair, but also by non- DSB repair genes. We demonstrated previously that suppressed expression of several non-DSB repair genes, such as XPA, elevated IR-induced cytogenetic damages. In the present study, we exposed human fibroblasts that were treated with control or XPA targeting siRNA to 250 MeV protons (0 to 4 Gy), and analyzed chromosome aberrations and expressions of genes involved in DNA repair. As expected, after proton irradiation, cells with suppressed expression of XPA showed a significantly elevated frequency of chromosome aberrations compared with control siRNA treated (CS) cells. Protons caused more severe DNA damages in XPA knock-down cells, as 36% cells contained multiple aberrations compared to 25% in CS cells after 4Gy proton irradiation. Comparison of gene expressions using the real-time PCR array technique revealed that expressions of p53 and its regulated genes in irradiated XPA suppressed cells were altered similarly as in CS cells, suggesting that the impairment of IR induced DNA repair in XPA suppressed cells is p53-independent. Except for XPA, which was more than 2 fold down regulated in XPA suppressed cells, several other DNA damage sensing and repair genes (GTSE1, RBBP8, RAD51, UNG and XRCC2) were shown a more than 1.5 fold difference between XPA knock-down cells and CS cells after proton exposure. The possible involvement of these genes in the impairment of DNA repair in XPA suppressed cells will be further investigated.

  2. Cytogenetic Response to Ionizing Radiation Exposure in Human Fibroblasts with Suppressed Expression of Non-DSB Repair Genes

    NASA Technical Reports Server (NTRS)

    Zhang, Ye; Rohde, Larry H.; Emami, Kamal; Hammond, Dianne; Mehta, Satish K.; Jeevarajan, Antony S.; Pierson, Duane L.; Wu, Honglu

    2009-01-01

    Changes of gene expression profile are one of the most important biological responses in living cells after ionizing radiation (IR) exposure. Although some studies have shown that genes up-regulated by IR may play important roles in DNA damage repair, the relationship between the regulation of gene expression by IR, particularly genes not known for their roles in double-strand break (DSB) repair, and its impact on cytogenetic responses has not been well studied. The purpose of this study is to identify new roles of IR inducible genes in radiation-induced chromosome aberrations and micronuclei formation. In the study, the expression of 25 genes selected on the basis of their transcriptional changes in response to IR was individually knocked down by small interfering RNA in human fibroblast cells. Frequencies of micronuclei (MN) formation and chromosome aberrations were measured to determine the efficiency of cytogenetic repair, and the fraction of bi-nucleated cells in the MN analysis was used as a marker for cell cycle progression. In response to gamma radiation, the formation of MN was significantly increased by suppressed expression of five genes: Ku70 (DSB repair pathway), XPA (nucleotide excision repair pathway), RPA1 (mismatch repair pathway), RAD17 and RBBP8 (cell cycle control). Knocked-down expression of four genes (MRE11A, RAD51 in the DSB pathway, SESN1, and SUMO1) significantly inhibited cell cycle progression, possibly because of severe impairment of DNA damage repair. Moreover, decreased XPA, p21, or MLH1 expression resulted in both significantly enhanced cell cycle progression and increased yields of chromosome aberrations, indicating that these gene products modulate both cell cycle control and DNA damage repair. Nine of these eleven genes, whose knock-down expression affected cytogenetic repair, were up-regulated in cells exposed to gamma radiation, suggesting that genes transcriptionally modulated by IR were critical to regulate IR

  3. Cytogenetics

    SciTech Connect

    Obe, G.; Basler, A.

    1987-01-01

    Different aspects of cytogenetics, such as the molecular structure of eukaryotic chromosomes, computerized analyses of chromosomes, evolution of karyotypes, chromosomes and cancer, chromosomes in genetic toxicology, and chromosomal aberrations (-induction, -in human populations, -in human eggs and sperm) are covered in this book. New techniques and approaches accompany overviews of all the different aspects of eukaryotic chromosomes.

  4. Evaluating the effects of genetic variants of DNA repair genes using cytogenetic mutagen sensitivity approaches

    PubMed Central

    Abdel-Rahman, Sherif Z.; El-Zein, Randa A.

    2011-01-01

    Mutagen sensitivity, measured in short-term cultures of peripheral blood lymphocytes by cytogenetic endpoints, is an indirect measure for DNA repair capacity and has been used for many years as a biomarker for intrinsic susceptibility for cancer. In this article, we briefly give an overview of the different cytogenetic mutagen sensitivity approaches that have been used successfully to evaluate the biological effects of polymorphisms in DNA repair genes based on a current review of the literature and based on the need for biomarkers that would allow the characterization of the biological and functional significance of such polymorphisms. We also address some of the future challenges facing this emerging area of research. PMID:21595606

  5. Non-DBS DNA Repair Genes Regulate Radiation-induced Cytogenetic Damage Repair and Cell Cycle Progression

    NASA Technical Reports Server (NTRS)

    Zhang, Ye; Rohde, Larry H.; Emami, Kamal; Casey, Rachael; Wu, Honglu

    2008-01-01

    Changes of gene expression profile are one of the most important biological responses in living cells after ionizing radiation (IR) exposure. Although some studies have shown that genes up-regulated by IR may play important roles in DNA damage repair, the relationship between the regulation of gene expression by IR, particularly genes not known for their roles in DSB repair, and its impact on cytogenetic responses has not been systematically studied. In the present study, the expression of 25 genes selected on the basis of their transcriptional changes in response to IR was individually knocked down by transfection with small interfering RNA in human fibroblast cells. The purpose of this study is to identify new roles of these selected genes on regulating DSB repair and cell cycle progression , as measured in the micronuclei formation and chromosome aberration. In response to IR, the formation of MN was significantly increased by suppressed expression of 5 genes: Ku70 in the DSB repair pathway, XPA in the NER pathway, RPA1 in the MMR pathway, and RAD17 and RBBP8 in cell cycle control. Knocked-down expression of 4 genes (MRE11A, RAD51 in the DSB pathway, SESN1, and SUMO1) significantly inhibited cell cycle progression, possibly because of severe impairment of DNA damage repair. Furthermore, loss of XPA, P21, or MLH1 expression resulted in both significantly enhanced cell cycle progression and increased yields of chromosome aberrations, indicating that these gene products modulate both cell cycle control and DNA damage repair. Most of the 11 genes that affected cytogenetic responses are not known to have clear roles influencing DBS repair. Nine of these 11 genes were up-regulated in cells exposed to gamma radiation, suggesting that genes transcriptionally modulated by IR were critical to regulate the biological consequences after IR.

  6. Induction and repair of HZE induced cytogenetic damage

    NASA Technical Reports Server (NTRS)

    Brooks, A. L.; Bao, S.; Rithidech, K.; Chrisler, W. B.; Couch, L. A.; Braby, L. A.

    2001-01-01

    Wistar rats were exposed to high-mass, high energy (HZE) 56Fe particles (1000 GeV/AMU) using the Alternating Gradient Synchrotron (AGS). The animals were sacrificed at 1-5 hours or after a 30-day recovery period. The frequency of micronuclei in the tracheal and the deep lung epithelial cells were evaluated. The relative effectiveness of 56Fe, for the induction of initial chromosome damage in the form of micronuclei, was compared to damage produced in the same biological system exposed to other types of high and low-LET radiation. It was demonstrated that for animals sacrificed at short times after exposure, the tracheal and lung epithelial cells, the 56Fe particles were 3.3 and 1.3 times as effective as 60Co in production of micronuclei, respectively. The effectiveness was also compared to that for exposure to inhaled radon. With this comparison, the 56Fe exposure of the tracheal epithelial cells and the lung epithelial cells were only 0.18 and 0.20 times as effective as radon in the production of the initial cytogenetic damage. It was suggested that the low relative effectiveness was related to potential for 'wasted energy' from the core of the 56Fe particles. When the animals were sacrificed after 30 days, the slopes of the dose-response relationships, which reflect the remaining level of damage, decreased by a factor of 10 for both the tracheal and lung epithelial cells. In both cases, the slope of the dose-response lines were no longer significantly different from zero, and the r2 values were very high. Lung epithelial cells, isolated from the animals sacrificed hours after exposure, were maintained in culture, and the micronuclei frequency evaluated after 4 and 6 subcultures. These cells were harvested at 24 and 36 days after the exposure. There was no dose-response detected in these cultures and no signs of genomic instability at either sample time.

  7. Impaired Cytogenetic Damage Repair and Cell Cycle Regulation in Response to Ionizing Radiation in Human Fibroblast Cells with Individual Knock-down of 25 Genes

    NASA Technical Reports Server (NTRS)

    Zhang, Ye; Rohde, Larry; Emami, Kamal; Hammond, Dianne; Casey, Rachael; Mehta, Satish; Jeevarajan, Antony; Pierson, Duane; Wu, Honglu

    2008-01-01

    Changes of gene expression profile are one of the most important biological responses in living cells after ionizing radiation (IR) exposure. Although some studies have demonstrated that genes with upregulated expression induced by IR may play important roles in DNA damage sensing, cell cycle checkpoint and chromosomal repair, the relationship between the regulation of gene expression by IR and its impact on cytogenetic responses to ionizing radiation has not been systematically studied. In our present study, the expression of 25 genes selected based on their transcriptional changes in response to IR or from their known DNA repair roles were individually knocked down by siRNA transfection in human fibroblast cells. Chromosome aberrations (CA) and micronuclei (MN) formation were measured as the cytogenetic endpoints. Our results showed that the yield of MN and/or CA formation were significantly increased by suppressed expression of 5 genes that included Ku70 in the DSB repair pathway; XPA in the NER pathway; RPA1 in the MMR pathway; RAD17 and RBBP8 in cell cycle control. Knocked-down expression of 4 genes including MRE11A, RAD51 in the DSB pathway, and SESN1 and SUMO1 showed significant inhibition of cell cycle progression, possibly because of severe impairment of DNA damage repair. Furthermore, loss of XPA, p21 and MLH1 expression resulted in both enhanced cell cycle progression and significantly higher yield of cytogenetic damage, indicating the involvement of these gene products in both cell cycle control and DNA damage repair. Of these 11 genes that affected the cytogenetic response, 9 were up-regulated in the cells exposed to gamma radiation, suggesting that genes transcriptionally modulated by IR were critical to regulating the biological consequences after IR. Failure to express these IR-responsive genes, such as by gene mutation, could seriously change the outcome of the post IR scenario and lead to carcinogenesis.

  8. Molecular Understanding of Efficient DNA Repair Machinery of Photolyase

    NASA Astrophysics Data System (ADS)

    Tan, Chuang; Liu, Zheyun; Li, Jiang; Guo, Xunmin; Wang, Lijuan; Zhong, Dongping

    2012-06-01

    Photolyases repair the UV-induced pyrimidine dimers in damage DNA with high efficiency, through a cylic light-driven electron transfer radical mechanism. We report here our systematic studies of the repair dynamics in E. coli photolyase with mutation of five active-site residues. The significant loss of repair efficiency by the mutation indicates that those active-site residues play an important role in the DNA repair by photolyase. To understand how the active-site residues modulate the efficiency, we mapped out the entire evolution of each elementary step during the repair in those photolyase mutants with femtosecond resolution. We completely analyzed the electron transfer dynamics using the Sumi-Marcus model. The results suggest that photolyase controls the critical electron transfer and the ring-splitting of pyrimidine dimer through modulation of the redox potentials and reorganization energies, and stabilization of the anionic intermediates, maintaining the dedicated balance of all the reaction steps and achieving the maximum function activity.

  9. Cancer Cytogenetics: Methodology Revisited

    PubMed Central

    2014-01-01

    The Philadelphia chromosome was the first genetic abnormality discovered in cancer (in 1960), and it was found to be consistently associated with CML. The description of the Philadelphia chromosome ushered in a new era in the field of cancer cytogenetics. Accumulating genetic data have been shown to be intimately associated with the diagnosis and prognosis of neoplasms; thus, karyotyping is now considered a mandatory investigation for all newly diagnosed leukemias. The development of FISH in the 1980s overcame many of the drawbacks of assessing the genetic alterations in cancer cells by karyotyping. Karyotyping of cancer cells remains the gold standard since it provides a global analysis of the abnormalities in the entire genome of a single cell. However, subsequent methodological advances in molecular cytogenetics based on the principle of FISH that were initiated in the early 1990s have greatly enhanced the efficiency and accuracy of karyotype analysis by marrying conventional cytogenetics with molecular technologies. In this review, the development, current utilization, and technical pitfalls of both the conventional and molecular cytogenetics approaches used for cancer diagnosis over the past five decades will be discussed. PMID:25368816

  10. The molecular origin of high DNA-repair efficiency by photolyase.

    PubMed

    Tan, Chuang; Liu, Zheyun; Li, Jiang; Guo, Xunmin; Wang, Lijuan; Sancar, Aziz; Zhong, Dongping

    2015-01-01

    The primary dynamics in photomachinery such as charge separation in photosynthesis and bond isomerization in sensory photoreceptor are typically ultrafast to accelerate functional dynamics and avoid energy dissipation. The same is also true for the DNA repair enzyme, photolyase. However, it is not known how the photoinduced step is optimized in photolyase to attain maximum efficiency. Here, we analyse the primary reaction steps of repair of ultraviolet-damaged DNA by photolyase using femtosecond spectroscopy. With systematic mutations of the amino acids involved in binding of the flavin cofactor and the cyclobutane pyrimidine dimer substrate, we report our direct deconvolution of the catalytic dynamics with three electron-transfer and two bond-breaking elementary steps and thus the fine tuning of the biological repair function for optimal efficiency. We found that the maximum repair efficiency is not enhanced by the ultrafast photoinduced process but achieved by the synergistic optimization of all steps in the complex repair reaction. PMID:26065359

  11. The molecular origin of high DNA-repair efficiency by photolyase

    NASA Astrophysics Data System (ADS)

    Tan, Chuang; Liu, Zheyun; Li, Jiang; Guo, Xunmin; Wang, Lijuan; Sancar, Aziz; Zhong, Dongping

    2015-06-01

    The primary dynamics in photomachinery such as charge separation in photosynthesis and bond isomerization in sensory photoreceptor are typically ultrafast to accelerate functional dynamics and avoid energy dissipation. The same is also true for the DNA repair enzyme, photolyase. However, it is not known how the photoinduced step is optimized in photolyase to attain maximum efficiency. Here, we analyse the primary reaction steps of repair of ultraviolet-damaged DNA by photolyase using femtosecond spectroscopy. With systematic mutations of the amino acids involved in binding of the flavin cofactor and the cyclobutane pyrimidine dimer substrate, we report our direct deconvolution of the catalytic dynamics with three electron-transfer and two bond-breaking elementary steps and thus the fine tuning of the biological repair function for optimal efficiency. We found that the maximum repair efficiency is not enhanced by the ultrafast photoinduced process but achieved by the synergistic optimization of all steps in the complex repair reaction.

  12. Mosquito cytogenetics

    PubMed Central

    Kitzmiller, James B.

    1963-01-01

    Although an intensified interest in mosquito cytogenetics in the past decade has produced a number of contributions to knowledge on this subject, the available information is still superficial and limited to a few mosquito species only. The author of this review summarizes the research done in this field between 1953 and 1962. The following are some of the achievements and some of the gaps that remain to be filled. Karyotypes of several species of Anopheles, Aedes and Culex conform to the general pattern 2n=6, with heterosomes distinguishable only in Anopheles. At least three different karyotypes are present in Anopheles. Salivary gland chromosome maps are now available for several anopheline species, but are still lacking for Culex and Aedes. No precise correlation may yet be made between the frequency of chromosomal aberrations and the degree of insecticide-resistance. Sexual differences in the salivary X-chromosomes have been reported for several species of Anopheles. Chromosomal polymorphism is common in some anophelines, but rare in others. Chromosomal mutation has been induced by means of X-rays. In his conclusions, the author stresses that prospects are especially good for evolutionary and genetic studies involving chromosomal polymorphism. PMID:14058227

  13. Dual daughter strand incision is processive and increases the efficiency of DNA mismatch repair.

    PubMed

    Hermans, Nicolaas; Laffeber, Charlie; Cristovão, Michele; Artola-Borán, Mariela; Mardenborough, Yannicka; Ikpa, Pauline; Jaddoe, Aruna; Winterwerp, Herrie H K; Wyman, Claire; Jiricny, Josef; Kanaar, Roland; Friedhoff, Peter; Lebbink, Joyce H G

    2016-08-19

    DNA mismatch repair (MMR) is an evolutionarily-conserved process responsible for the repair of replication errors. In Escherichia coli, MMR is initiated by MutS and MutL, which activate MutH to incise transiently-hemimethylated GATC sites. MMR efficiency depends on the distribution of these GATC sites. To understand which molecular events determine repair efficiency, we quantitatively studied the effect of strand incision on unwinding and excision activity. The distance between mismatch and GATC site did not influence the strand incision rate, and an increase in the number of sites enhanced incision only to a minor extent. Two GATC sites were incised by the same activated MMR complex in a processive manner, with MutS, the closed form of MutL and MutH displaying different roles. Unwinding and strand excision were more efficient on a substrate with two nicks flanking the mismatch, as compared to substrates containing a single nick or two nicks on the same side of the mismatch. Introduction of multiple nicks by the human MutLα endonuclease also contributed to increased repair efficiency. Our data support a general model of prokaryotic and eukaryotic MMR in which, despite mechanistic differences, mismatch-activated complexes facilitate efficient repair by creating multiple daughter strand nicks. PMID:27174933

  14. The contribution of CMP kinase to the efficiency of DNA repair

    PubMed Central

    Tsao, Ning; Lee, Ming-Hsiang; Zhang, Wei; Cheng, Yung-Chi; Chang, Zee-Fen

    2015-01-01

    Cellular supply of deoxynucleoside triphosphates (dNTPs) is crucial for DNA replication and repair. In this study, we investigated the role of CMP/UMP kinase (CMPK), an enzyme catalyzes CDP formation, in DNA repair. Knockdown of CMPK delays DNA repair during recovery from UV damage in serum-deprived cells but not in the cells without serum deprivation. Exogenous supply of cytidine or deoxycytidine facilitates DNA repair dependent on CMPK in serum-deprived cells, suggesting that the synthesis of dCDP or CDP determines the rate of repair. However, CMPK knockdown does not affect the steady state level of dCTP in serum-deprived cells. We then found the localization of CMPK at DNA damage sites and its complex formation with Tip60 and ribonucleotide reductase. Our analysis demonstrated that the N-terminal 32-amino-acid of CMPK is required for its recruitment to DNA damage sites in a Tip60-dependent manner. Re-expression of wild-type but not N-terminus deleted CMPK restores the efficiency of DNA repair in CMPK knockdown cells. We proposed that site-specific dCDP formation via CMPK provides a means to facilitate DNA repair in serum-deprived cells. PMID:25659034

  15. Investigation and Assessment of the Influence of Repairs on Transport System Operation Efficiency and Reliability

    NASA Astrophysics Data System (ADS)

    Muślewski, Łukasz; Woropay, Maciej; Bojar, Piotr

    2012-03-01

    Transport systems, especially transport means operated by them, generate different types of threats: peoples' health and life threat and natural environment degradation threat. Operating factors affecting elements of technical objects cause negative value changes of these elements resulting in their failure. These factors include those which result from improper behavior of people and those connected with the environmental impact affecting the technical object. Failure is a circumstance which significantly decreases the vehicle reliability and efficiency. In this study, a failure is referred to as exceeding permitted boundary values by significant features of the technical object. On the basis of performed practical tests concerning times of a failure occurrence it was found that the set of failures can be divided into subsets of primary and secondary ones. Tests results revealed that the cause of occurrence of secondary failures are usually incorrect performance of primary repairs. Primary repairs are independent on each other and occur randomly. Secondary failures, in turn, are related to each other and their occurrence is conditioned by an earlier occurrence of a primary failure and the effect of its improper repair or a repair of a successive secondary one. Therefore, assurance of high efficiency of repairs performed on the transport means is of great importance as this affects the level of reliability, safety and efficiency of transport tasks.

  16. Dysregulation of apoptotic death in the pathogenesis of virus-induced cytogenetic instability of blood lymphocytes.

    PubMed

    Ryazantseva, N V; Novitskii, V V; Zhukova, O B; Radzivil, T T; Mikheev, S L; Chechina, O E; Zima, A P; Shilov, B V

    2006-05-01

    The cytogenetic status and activity of regulatory systems for stability of the cell genome were evaluated in patients with chronic viral persistence. Hepatitis B and C viruses damage the chromosome apparatus of peripheral blood lymphocytes. Cytogenetic instability of immunocompetent cells during chronic viral infection was associated with inhibition of DNA excision repair system and dysregulation of apoptosis in target cells. PMID:17181065

  17. Facioscapulohumeral dystrophy myoblasts efficiently repair moderate levels of oxidative DNA damage.

    PubMed

    Bou Saada, Yara; Dib, Carla; Dmitriev, Petr; Hamade, Aline; Carnac, Gilles; Laoudj-Chenivesse, Dalila; Lipinski, Marc; Vassetzky, Yegor S

    2016-04-01

    Facioscapulohumeral dystrophy (FSHD) is a progressive muscular dystrophy linked to a deletion of a subset of D4Z4 macrosatellite repeats accompanied by a chromatin relaxation of the D4Z4 array on chromosome 4q. In vitro, FSHD primary myoblasts show altered expression of oxidative-related genes and are more susceptible to oxidative stress. Double homeobox 4 (DUX4) gene, encoded within each D4Z4 unit, is normally transcriptionally silenced but is found aberrantly expressed in skeletal muscles of FSHD patients. Its expression leads to a deregulation of DUX4 target genes including those implicated in redox balance. Here, we assessed DNA repair efficiency of oxidative DNA damage in FSHD myoblasts and DUX4-transfected myoblasts. We have shown that the DNA repair activity is altered neither in FSHD myoblasts nor in immortalized human myoblasts transiently expressing DUX4. DNA damage caused by moderate doses of an oxidant is efficiently repaired while FSHD myoblasts exposed for 24 h to high levels of oxidative stress accumulated more DNA damage than normal myoblasts, suggesting that FSHD myoblasts remain more vulnerable to oxidative stress at high doses of oxidants. PMID:26860865

  18. DNA repair efficiency in germ cells and early mouse embryos and consequences for radiation-induced transgenerational genomic damage

    SciTech Connect

    Marchetti, Francesco; Wyrobek, Andrew J.

    2009-01-18

    Exposure to ionizing radiation and other environmental agents can affect the genomic integrity of germ cells and induce adverse health effects in the progeny. Efficient DNA repair during gametogenesis and the early embryonic cycles after fertilization is critical for preventing transmission of DNA damage to the progeny and relies on maternal factors stored in the egg before fertilization. The ability of the maternal repair machinery to repair DNA damage in both parental genomes in the fertilizing egg is especially crucial for the fertilizing male genome that has not experienced a DNA repair-competent cellular environment for several weeks prior to fertilization. During the DNA repair-deficient period of spermatogenesis, DNA lesions may accumulate in sperm and be carried into the egg where, if not properly repaired, could result in the formation of heritable chromosomal aberrations or mutations and associated birth defects. Studies with female mice deficient in specific DNA repair genes have shown that: (i) cell cycle checkpoints are activated in the fertilized egg by DNA damage carried by the sperm; and (ii) the maternal genotype plays a major role in determining the efficiency of repairing genomic lesions in the fertilizing sperm and directly affect the risk for abnormal reproductive outcomes. There is also growing evidence that implicates DNA damage carried by the fertilizing gamete as a mediator of postfertilization processes that contribute to genomic instability in subsequent generations. Transgenerational genomic instability most likely involves epigenetic mechanisms or error-prone DNA repair processes in the early embryo. Maternal and embryonic DNA repair processes during the early phases of mammalian embryonic development can have far reaching consequences for the genomic integrity and health of subsequent generations.

  19. Methods in human cytogenetics

    SciTech Connect

    1993-12-31

    Chapter 4, discusses the various techniques used in the study human cytogenetics. The methods are discussed in historical order, from direct methods to tissue culture techniques, prenatal studies, meiotic studies, sex chromatin techniques, banding techniques, prophase banding and replication studies. Nomenclature of human chromosomes and quantitative methods are also mentioned. 60 refs., 3 figs.

  20. Mdt1 Facilitates Efficient Repair of Blocked DNA Double-Strand Breaks and Recombinational Maintenance of Telomeres▿

    PubMed Central

    Pike, Brietta L.; Heierhorst, Jörg

    2007-01-01

    DNA recombination plays critical roles in DNA repair and alternative telomere maintenance. Here we show that absence of the SQ/TQ cluster domain-containing protein Mdt1 (Ybl051c) renders Saccharomyces cerevisiae particularly hypersensitive to bleomycin, a drug that causes 3′-phospho-glycolate-blocked DNA double-strand breaks (DSBs). mdt1Δ also hypersensitizes partially recombination-defective cells to camptothecin-induced 3′-phospho-tyrosyl protein-blocked DSBs. Remarkably, whereas mdt1Δ cells are unable to restore broken chromosomes after bleomycin treatment, they efficiently repair “clean” endonuclease-generated DSBs. Epistasis analyses indicate that MDT1 acts in the repair of bleomycin-induced DSBs by regulating the efficiency of the homologous recombination pathway as well as telomere-related functions of the KU complex. Moreover, mdt1Δ leads to severe synthetic growth defects with a deletion of the recombination facilitator and telomere-positioning factor gene CTF18 already in the absence of exogenous DNA damage. Importantly, mdt1Δ causes a dramatic shift from the usually prevalent type II to the less-efficient type I pathway of recombinational telomere maintenance in the absence of telomerase in liquid senescence assays. As telomeres resemble protein-blocked DSBs, the results indicate that Mdt1 acts in a novel blocked-end-specific recombination pathway that is required for the efficiency of both drug-induced DSB repair and telomerase-independent telomere maintenance. PMID:17636027

  1. Cytogenetics and cladistics.

    PubMed

    Dobigny, Gauthier; Ducroz, Jean-François; Robinson, Terence J; Volobouev, Vitaly

    2004-06-01

    Chromosomal data have been underutilized in phylogenetic investigations despite the obvious potential that cytogenetic studies have to reveal both structural and functional homologies among taxa. In large part this is associated with difficulties in scoring conventional and molecular cytogenetic information for phylogenetic analysis. The manner in which chromosomal data have been used by most authors in the past was often conceptionally flawed in terms of the methods and principles underpinning modern cladistics. We present herein a review of the different methods employed, examine their relative strengths, and then outline a simple approach that considers the chromosomal change as the character, and its presence or absence the character state. We test this using one simulated and several empirical data sets. Features that are unique to cytogenetic investigations, including B-chromosomes, heterochromatic additions/deletions, and the location and number of nucleolar organizer regions (NORs), as well as the weighting of chromosomal characters, are critically discussed with regard to their suitability for phylogenetic reconstruction. We conclude that each of these classes of data have inherent problems that limit their usefulness in phylogenetic analyses and in most of these instances, inclusion should be subject to rigorous appraisal that addresses the criterion of unequivocal homology. PMID:15503674

  2. Improvement of ENU Mutagenesis Efficiency Using Serial Injection and Mismatch Repair Deficiency Mice

    PubMed Central

    Pitstick, Rose; Peters, Janet; Carlson, George A.

    2016-01-01

    ENU mutagenesis is a powerful method for generating novel lines of mice that are informative with respect to both fundamental biological processes and human disease. Rapid developments in genomic technology have made the task of identifying causal mutations by positional cloning remarkably efficient. One limitation of this approach remains the mutation frequency achievable using standard treatment protocols, which currently generate approximately 1–2 sequence changes per megabase when optimized. In this study we used two strategies to attempt to increase the number of mutations induced by ENU treatment. One approach employed mice carrying a mutation in the DNA repair enzyme Msh6. The second strategy involved injection of ENU to successive generations of mice. To evaluate the number of ENU-induced mutations, single mice or pooled samples were analyzed using whole exome sequencing. The results showed that there is considerable variability in the induced mutation frequency using these approaches, but an overall increase in ENU-induced variants from one generation to another was observed. The analysis of the mice deficient for Msh6 also showed an increase in the ENU-induced variants compared to the wild-type ENU-treated mice. However, in both cases the increase in ENU-induced mutation frequency was modest. PMID:27441645

  3. Plant cytogenetics in genome databases

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cytogenetic maps provide an integrated representation of genetic and cytological information that can be used to enhance genome and chromosome research. As genome analysis technologies become more affordable, the density of markers on cytogenetic maps increases, making these resources more useful a...

  4. Cytogenetic highlights and transitions.

    PubMed

    Spinner, Nancy B

    2016-06-01

    Medical cytogenetics, genetic diagnostics, and medical genetics had their origins in the late 1950's, as evaluation of human chromosomes became possible, and it was recognized that chromosomal abnormalities could cause a variety of clinical phenotypes. Dr. Laird Jackson began his medical and scientific career just as this field was emerging and he was an early adopter and driver of several key trends in the development of these fields, notably in the area of prenatal diagnostics. Laird's greatest impact was in his work to demonstrate the clinical utility of amniocentesis, chorionic villous sampling, and chromosomal microarray analysis for prenatal diagnosis. © 2016 Wiley Periodicals, Inc. PMID:27097074

  5. [Cytogenetics of bone sarcomas].

    PubMed

    Vagner-Capodano, A M; Poitout, D

    There has been much progress in the cytogenesis, and molecular biology of bone tumours such as Ewing sarcoma and osteosarcomas, greatly improving diagnostic possibilities and prognosis. Ewing's sarcoma is an indifferentiated sarcoma with round cells which usually occurs in children or adolescents. Ewing's sarcoma corresponds to 6% of all bone tumours. Histologically Ewing's sarcoma belongs to a group of small round cell tumours including neuroblastoma, embryon and alveolar rhabdomyosarcoma and non-Hodgkin's lymphoma. Differential diagnosis is difficult. Cytogenetic examinations can now differentiate Ewing's sarcoma from other small round cell tumours. There is a specific 11:12 translocation (q24; q12) which can be used as a marker. PMID:8785922

  6. Dynamics and Mechanism of Efficient DNA Repair Reviewed by Active-Site Mutants

    NASA Astrophysics Data System (ADS)

    Tan, Chuang; Liu, Zheyun; Li, Jiang; Guo, Xunmin; Wang, Lijuan; Zhong, Dongping

    2010-06-01

    Photolyases repair the UV-induced pyrimidine dimers in damage DNA via a photoreaction which includes a series of light-driven electron transfers between the two-electron-reduced flavin cofactor FADH^- and the dimer. We report here our systematic studies of the repair dynamics in E. coli photolyase with mutation of several active-site residues. With femtosecond resolution, we observed the significant change in the forward electron transfer from the excited FADH^- to the dimer and the back electron transfer from the repaired thymines by mutation of E274A, R226A, R342A, N378S and N378C. We also found that the mutation of E274A accelerates the bond-breaking of the thymine dimer. The dynamics changes are consistent with the quantum yield study of these mutants. These results suggest that the active-site residues play a significant role, structurally and chemically, in the DNA repair photocycle.

  7. Overview of Clinical Cytogenetics.

    PubMed

    Gonzales, Patrick R; Carroll, Andrew J; Korf, Bruce R

    2016-01-01

    Chromosome analysis is one of the first approaches to genetic testing and remains a key component of genetic analysis of constitutional and somatic genetic disorders. Numerical or unbalanced structural chromosome abnormalities usually lead to multiple congenital anomalies. Sometimes these are compatible with live birth, usually resulting in severe cognitive and physical handicaps; other times they result in miscarriage or stillbirth. Chromosome rearrangements also occur as somatic changes in malignancies. Identification of constitutional chromosomal anomalies (anomalies present in most or all cells of the body and/or the germline) can provide important information for genetic counseling. In this unit, we introduce chromosomal microarray analysis (CMA), which is a relatively recent addition to cytogenetic technologies, and has become the recommended first-tier testing method for patients with developmental delay, intellectual disability, autism, and/or multiple congenital anomalies. We also discuss non-invasive prenatal testing/screening (NIPTS), which uses circulating cell-free fetal DNA (cfDNA) from maternal plasma to rapidly screen for autosomal and sex-chromosome aneuploidies. Cytogenetic analysis of tumors is helpful in diagnosis and in monitoring the effects of treatment. The protocols in this chapter cover the clinical study of chromosomes in nonmalignant tissues. © 2016 by John Wiley & Sons, Inc. PMID:27037488

  8. Cytogenetic effects of cyclamates

    SciTech Connect

    Jemison, E.W.; Brown, K.; Rivers, B.; Knight, R.

    1984-01-01

    PHA-stimulated human peripheral lymphocytes were used as a model system for assessing the in vitro effects of calcium cyclamate. Techniques of autoradiography, cytological staining, cell counting, liquid scintillation and karyotyping were used to study the cytogenetic damage and biochemical effects of calcium cyclamate when assayed in 24 hour intervals for 96 hours. The cells were exposed to 10(-2) and 10(-3) molar concentrations of calcium cyclamate in TC 199 medium with fetal calf serum and antibiotics. It was noted that the addition of cyclamate increased mitotic rate of lymphocyte cells in cultures. It was determined that calcium cyclamate impaired the synthesis of deoxribonunucleic acid (as depicted by decreased incorporation of tritiated thymidine), reduced grain counts in autoradiographs and increased chromosome aberrations in cyclamate treated PHA stimulated peripheral blood lymphocytes in vitro. Morphological changes and growth rates showed significant effects. These studies indicate that calcium cyclamate has variable significant effects on leucocytes growth and chromosome morphology.

  9. The evolution of a cytogenetics education program.

    PubMed Central

    Becan-McBride, K; Cork, A

    1993-01-01

    An educational program in clinical cytogenetics was initiated in 1983 at the University of Texas Health Science Center at Houston, through the Medical Technology Program in the School of Allied Health Sciences. Through the years the program has evolved into a more efficient curriculum, with the possibility of becoming a part of a master's degree program in allied health sciences. It is hoped that a description of the program will be of help to other educational institutions that may be contemplating the establishment of a similar course of study. PMID:8434593

  10. Stable interactions between DNA polymerase δ catalytic and structural subunits are essential for efficient DNA repair.

    PubMed

    Brocas, Clémentine; Charbonnier, Jean-Baptiste; Dhérin, Claudine; Gangloff, Serge; Maloisel, Laurent

    2010-10-01

    Eukaryotic DNA polymerase δ (Pol δ) activity is crucial for chromosome replication and DNA repair and thus, plays an essential role in genome stability. In Saccharomyces cerevisiae, Pol δ is a heterotrimeric complex composed of the catalytic subunit Pol3, the structural B subunit Pol31, and Pol32, an additional auxiliary subunit. Pol3 interacts with Pol31 thanks to its C-terminal domain (CTD) and this interaction is of functional importance both in DNA replication and DNA repair. Interestingly, deletion of the last four C-terminal Pol3 residues, LSKW, in the pol3-ct mutant does not affect DNA replication but leads to defects in homologous recombination and in break-induced replication (BIR) repair pathways. The defect associated with pol3-ct could result from a defective interaction between Pol δ and a protein involved in recombination. However, we show that the LSKW motif is required for the interaction between Pol3 C-terminal end and Pol31. This loss of interaction is relevant in vivo since we found that pol3-ct confers HU sensitivity on its own and synthetic lethality with a POL32 deletion. Moreover, pol3-ct shows genetic interactions, both suppression and synthetic lethality, with POL31 mutant alleles. Structural analyses indicate that the B subunit of Pol δ displays a major conserved region at its surface and that pol31 alleles interacting with pol3-ct, correspond to substitutions of Pol31 amino acids that are situated in this particular region. Superimposition of our Pol31 model on the 3D architecture of the phylogenetically related DNA polymerase α (Pol α) suggests that Pol3 CTD interacts with the conserved region of Pol31, thus providing a molecular basis to understand the defects associated with pol3-ct. Taken together, our data highlight a stringent dependence on Pol δ complex stability in DNA repair. PMID:20813592

  11. A Mutation in a Saccharomyces Cerevisiae Gene (Rad3) Required for Nucleotide Excision Repair and Transcription Increases the Efficiency of Mismatch Correction

    PubMed Central

    Yang, Y.; Johnson, A. L.; Johnston, L. H.; Siede, W.; Friedberg, E. C.; Ramachandran, K.; Kunz, B. A.

    1996-01-01

    RAD3 functions in DNA repair and transcription in Saccharomyces cerevisiae and particular rad3 alleles confer a mutator phenotype, possibly as a consequence of defective mismatch correction. We assessed the potential involvement of the Rad3 protein in mismatch correction by comparing heteroduplex repair in isogenic rad3-1 and wild-type strains. The rad3-1 allele increased the spontaneous mutation rate but did not prevent heteroduplex repair or bias its directionality. Instead, the efficiency of mismatch correction was enhanced in the rad3-1 strain. This surprising result prompted us to examine expression of yeast mismatch repair genes. We determined that MSH2, but not MLH1, is transcriptionally regulated during the cell-cycle like PMS1, and that rad3-1 does not increase the transcript levels for these genes in log phase cells. These observations suggest that the rad3-1 mutation gives rise to an enhanced efficiency of mismatch correction via a process that does not involve transcriptional regulation of mismatch repair. Interestingly, mismatch repair also was more efficient when error-editing by yeast DNA polymerase δ was eliminated. We discuss our results in relation to possible mechanisms that may link the rad3-1 mutation to mismatch correction efficiency. PMID:8889512

  12. Cytogenetics of melanoma: a review.

    PubMed

    James, Aaron W; Chang, Le; Shrestha, Swati; Cochran, Alistair; Binder, Scott; Tirado, Carlos A

    2014-01-01

    Malignant melanoma is an aggressive cutaneous neoplasm whose incidence has continued to increase worldwide. Currently, histopathologic examination of specimens is the gold standard for the diagnosis and categorization of melanoma. Cytogenetic analysis represents a powerful, and currently underused, adjunct to traditional histologic examination in distinguishing nevi and melanomas. Chromosomal studies have shown that malignant melanomas often contain multiple chromosomal alterations, most commonly of chromosomes 1, 6, 7, 9, 10 and 11. These chromosomes often include genes within the MAPK molecular pathway, which is involved in the development and progression of melanoma. Fluorescence in situ hybridization (FISH) can detect a number of recurrent anomalies, and commercially available kits for melanoma detection have been devised. The utility of cytogenetics in melanocytic lesions at certain anatomic sites has been evaluated, including acral lesions, uveal lesions, and lymph node metastases. Recurring cytogenetic anomalies have been defined in various challenging histologic subtypes, such as desmoplastic melanomas and Spitzoid lesions. Cytogenetic analysis may also be used to provide supplementary information in prognostication, particularly in uveal melanomas. We provide a brief review of the molecular pathways found in melanoma and a summary of what is known and remains unknown regarding cytogenetic aberrations associated with malignant melanoma. PMID:26030295

  13. Non-homologous DNA increases gene disruption efficiency by altering DNA repair outcomes.

    PubMed

    Richardson, C D; Ray, G J; Bray, N L; Corn, J E

    2016-01-01

    The Cas9 endonuclease can be targeted to genomic sequences by programming the sequence of an associated single guide RNA (sgRNA). For unknown reasons, the activity of these Cas9-sgRNA combinations varies widely at different genomic loci and in different cell types. Thus, disrupting genes in polyploid cell lines or when using poorly performing sgRNAs can require extensive downstream screening to identify homozygous clones. Here we find that non-homologous single-stranded DNA greatly stimulates Cas9-mediated gene disruption in the absence of homology-directed repair. This stimulation increases the frequency of clones with homozygous gene disruptions and rescues otherwise ineffective sgRNAs. The molecular outcome of enhanced gene disruption depends upon cellular context, stimulating deletion of genomic sequence or insertion of non-homologous DNA at the edited locus in a cell line specific manner. Non-homologous DNA appears to divert cells towards error-prone instead of error-free repair pathways, dramatically increasing the frequency of gene disruption. PMID:27530320

  14. Non-homologous DNA increases gene disruption efficiency by altering DNA repair outcomes

    PubMed Central

    Richardson, C. D.; Ray, G. J.; Bray, N. L.; Corn, J. E.

    2016-01-01

    The Cas9 endonuclease can be targeted to genomic sequences by programming the sequence of an associated single guide RNA (sgRNA). For unknown reasons, the activity of these Cas9–sgRNA combinations varies widely at different genomic loci and in different cell types. Thus, disrupting genes in polyploid cell lines or when using poorly performing sgRNAs can require extensive downstream screening to identify homozygous clones. Here we find that non-homologous single-stranded DNA greatly stimulates Cas9-mediated gene disruption in the absence of homology-directed repair. This stimulation increases the frequency of clones with homozygous gene disruptions and rescues otherwise ineffective sgRNAs. The molecular outcome of enhanced gene disruption depends upon cellular context, stimulating deletion of genomic sequence or insertion of non-homologous DNA at the edited locus in a cell line specific manner. Non-homologous DNA appears to divert cells towards error-prone instead of error-free repair pathways, dramatically increasing the frequency of gene disruption. PMID:27530320

  15. Three nth homologs are all required for efficient repair of spontaneous DNA damage in Deinococcus radiodurans.

    PubMed

    Hua, Xiaoting; Xu, Xin; Li, Mingfeng; Wang, Chao; Tian, Bing; Hua, Yuejin

    2012-05-01

    Deinococcus radiodurans is a bacterium that can survive extreme DNA damage. To understand the role of endonuclease III (Nth) in oxidative repair and mutagenesis, we constructed nth single, double and triple mutants. The nth mutants showed no significant difference with wild type in both IR resistance and H(2)O(2) resistance. We characterized these strains with regard to mutation rates and mutation spectrum using the rpoB/Rif(r) system. The Rif(r) frequency of mutant MK1 (△dr0289) was twofold higher than that of wild type. The triple mutant of nth (ME3)generated a mutation frequency 34.4-fold, and a mutation rate 13.8-fold higher than the wild type. All strains demonstrated specific mutational hotspots. Each single mutant had higher spontaneous mutation frequency than wild type at base substitution (G:C → A:T). The mutational response was further increased in the double and triple mutants. The higher mutation rate and mutational response in ME3 suggested that the three nth homologs had non-overlapped and overlapped substrate spectrum in endogenous oxidative DNA repair. PMID:22527041

  16. Damage formation and repair efficiency in the p53 gene of cell lines and blood lymphocytes assayed by multiplex long quantitative polymerase chain reaction.

    PubMed

    Wang, Yu-Chieh; Lee, Pei-Jung; Shih, Chuen-Ming; Chen, Hsing-Yu; Lee, Chin-Chu; Chang, Yuan-Yen; Hsu, Yu-Ting; Liang, Ying-Ju; Wang, Li-Ya; Han, Wen-Hua; Wang, Yi-Ching

    2003-08-15

    We examined ultraviolet (UV) irradiation and cisplatin treatment damage formation and repair efficiency in the p53 tumor suppressor gene of various cultured cell lines and lymphocytes using a nonradioactive multiplex long quantitative polymerase chain reaction (QPCR) assay, which amplified a 7-kb fragment of the target gene and a 500-bp fragment of the template control to successfully increase the sensitivity and reliability of the assay. The multiplex long QPCR detected a lesion frequency of 0.63 lesions/10kb/10J/m(2) in the p53 gene of fibroblast cells. In addition, the multiplex long QPCR assay detected pronounced differences in the repair of UV damage in the p53 gene among repair-proficient CRL-1475 cells and repair-deficient XP-A and XP-C cells. The multiplex long QPCR assay was also evaluated as a sensitive assay for the detection of DNA damage induced by cisplatin. The data indicated that the lesion frequency in the p53 gene was 1.27-1.75 times higher in the H23 cisplatin-sensitive cell than in the H1435 cisplatin-resistant cell at the IC(70) dose. After 8-h and 24-h repair periods, only 13 and 75% of cisplatin-induced damage had been removed in the H23 cells, whereas these values were 92 and 100% in the H1435 cells. In addition, our data indicate that multiplex long QPCR is a sensitive method for validly estimating repair in freshly isolated lymphocytes. The results suggest that the current protocol of the multiplex long QPCR method can be used to assess the damage formation and repair efficiency of various agents at biologically relevant doses and to allow a more precise determination of gene-specific repair in disease susceptibility and drug resistance in epidemiological studies. PMID:12871714

  17. The SOS-dependent upregulation of uvrD is not required for efficient nucleotide excision repair of ultraviolet light induced DNA photoproducts in Escherichia coli.

    PubMed

    Crowley, D J; Hanawalt, P C

    2001-05-10

    We have shown previously that induction of the SOS response is required for efficient nucleotide excision repair (NER) of the major ultraviolet light (UV) induced DNA lesion, the cyclobutane pyrimidine dimer (CPD), but not for repair of 6-4 photoproducts (6-4PP) or for transcription-coupled repair of CPDs [1]. We have proposed that the upregulation of cellular NER capacity occurs in the early stages of the SOS response and enhances the rate of repair of the abundant yet poorly recognized genomic CPDs. The expression of three NER genes, uvrA, uvrB, and uvrD, is upregulated as part of the SOS response. UvrD differs from the others in that it is not involved in lesion recognition but rather in promoting the post-incision steps of NER, including turnover of the UvrBC incision complex. Since uvrC is not induced during the SOS response, its turnover would seem to be of great importance in promoting efficient NER. Here we show that the constitutive level of UvrD is adequate for carrying out efficient NER of both CPDs and 6-4PPs. Thus, the upregulation of uvrA and uvrB genes during the SOS response is sufficient for inducible NER of CPDs. We also show that cells with a limited NER capacity, in this case due to deletion of the uvrD gene, repair 6-4PPs but cannot perform transcription-coupled repair of CPDs, indicating that the 6-4PP is a better substrate for NER than is a CPD targeted for transcription-coupled repair. PMID:11585364

  18. [Cytogenetic studies in primary amenorrhea].

    PubMed

    Baron, J; Warenik-Szymankiewicz, A

    1975-01-01

    Cytogenetic analysis in 125 women with primary amenorrhea consisting of determinations of sex chromatin and karyotype, and in some cases of autoradiography were performed. On the basis of clinical, endocrinologic and cytogenetic criteria, the women were divided into ten clinical groups. In Turner's syndrome 45,X monosomie was observed only in 9 patients and in the remaining 12 cases varies types of mosaicism or of structural aberrations of the X chromosome. In pure gonadal dysgenesis, the patients exhibited 46,XY karyotype have the tendency to malign tumors of the gonads. In all cases with male pseudohermaphroditism the karyotypes 46,XY were observed. The remaining patients with primary amenorrhea exhibited 46,XX karyotype and belonged to the cases with Mayer-Rokitansky-Kustner syndrome, with adrenogenital syndrome, with hypoplasia of the ovaries, with primary amenorrhea of uterine or pituitary origin or at last with pubertas tarda. PMID:1189755

  19. Nanovector-based prolyl hydroxylase domain 2 silencing system enhances the efficiency of stem cell transplantation for infarcted myocardium repair

    PubMed Central

    Zhu, Kai; Lai, Hao; Guo, Changfa; Li, Jun; Wang, Yulin; Wang, Lingyan; Wang, Chunsheng

    2014-01-01

    Mesenchymal stem cell (MSC) transplantation has attracted much attention in myocardial infarction therapy. One of the limitations is the poor survival of grafted cells in the ischemic microenvironment. Small interfering RNA-mediated prolyl hydroxylase domain protein 2 (PHD2) silencing in MSCs holds tremendous potential to enhance their survival and paracrine effect after transplantation. However, an efficient and biocompatible PHD2 silencing system for clinical application is lacking. Herein, we developed a novel PHD2 silencing system based on arginine-terminated generation 4 poly(amidoamine) (Arg-G4) nanoparticles. The system exhibited effective and biocompatible small interfering RNA delivery and PHD2 silencing in MSCs in vitro. After genetically modified MSC transplantation in myocardial infarction models, MSC survival and paracrine function of IGF-1 were enhanced significantly in vivo. As a result, we observed decreased cardiomyocyte apoptosis, scar size, and interstitial fibrosis, and increased angiogenesis in the diseased myocardium, which ultimately attenuated ventricular remodeling and improved heart function. This work demonstrated that an Arg-G4 nanovector-based PHD2 silencing system could enhance the efficiency of MSC transplantation for infarcted myocardium repair. PMID:25429216

  20. Cytogenetic Prognostication Within Medulloblastoma Subgroups

    PubMed Central

    Shih, David J.H.; Northcott, Paul A.; Remke, Marc; Korshunov, Andrey; Ramaswamy, Vijay; Kool, Marcel; Luu, Betty; Yao, Yuan; Wang, Xin; Dubuc, Adrian M.; Garzia, Livia; Peacock, John; Mack, Stephen C.; Wu, Xiaochong; Rolider, Adi; Morrissy, A. Sorana; Cavalli, Florence M.G.; Jones, David T.W.; Zitterbart, Karel; Faria, Claudia C.; Schüller, Ulrich; Kren, Leos; Kumabe, Toshihiro; Tominaga, Teiji; Shin Ra, Young; Garami, Miklós; Hauser, Peter; Chan, Jennifer A.; Robinson, Shenandoah; Bognár, László; Klekner, Almos; Saad, Ali G.; Liau, Linda M.; Albrecht, Steffen; Fontebasso, Adam; Cinalli, Giuseppe; De Antonellis, Pasqualino; Zollo, Massimo; Cooper, Michael K.; Thompson, Reid C.; Bailey, Simon; Lindsey, Janet C.; Di Rocco, Concezio; Massimi, Luca; Michiels, Erna M.C.; Scherer, Stephen W.; Phillips, Joanna J.; Gupta, Nalin; Fan, Xing; Muraszko, Karin M.; Vibhakar, Rajeev; Eberhart, Charles G.; Fouladi, Maryam; Lach, Boleslaw; Jung, Shin; Wechsler-Reya, Robert J.; Fèvre-Montange, Michelle; Jouvet, Anne; Jabado, Nada; Pollack, Ian F.; Weiss, William A.; Lee, Ji-Yeoun; Cho, Byung-Kyu; Kim, Seung-Ki; Wang, Kyu-Chang; Leonard, Jeffrey R.; Rubin, Joshua B.; de Torres, Carmen; Lavarino, Cinzia; Mora, Jaume; Cho, Yoon-Jae; Tabori, Uri; Olson, James M.; Gajjar, Amar; Packer, Roger J.; Rutkowski, Stefan; Pomeroy, Scott L.; French, Pim J.; Kloosterhof, Nanne K.; Kros, Johan M.; Van Meir, Erwin G.; Clifford, Steven C.; Bourdeaut, Franck; Delattre, Olivier; Doz, François F.; Hawkins, Cynthia E.; Malkin, David; Grajkowska, Wieslawa A.; Perek-Polnik, Marta; Bouffet, Eric; Rutka, James T.; Pfister, Stefan M.; Taylor, Michael D.

    2014-01-01

    Purpose Medulloblastoma comprises four distinct molecular subgroups: WNT, SHH, Group 3, and Group 4. Current medulloblastoma protocols stratify patients based on clinical features: patient age, metastatic stage, extent of resection, and histologic variant. Stark prognostic and genetic differences among the four subgroups suggest that subgroup-specific molecular biomarkers could improve patient prognostication. Patients and Methods Molecular biomarkers were identified from a discovery set of 673 medulloblastomas from 43 cities around the world. Combined risk stratification models were designed based on clinical and cytogenetic biomarkers identified by multivariable Cox proportional hazards analyses. Identified biomarkers were tested using fluorescent in situ hybridization (FISH) on a nonoverlapping medulloblastoma tissue microarray (n = 453), with subsequent validation of the risk stratification models. Results Subgroup information improves the predictive accuracy of a multivariable survival model compared with clinical biomarkers alone. Most previously published cytogenetic biomarkers are only prognostic within a single medulloblastoma subgroup. Profiling six FISH biomarkers (GLI2, MYC, chromosome 11 [chr11], chr14, 17p, and 17q) on formalin-fixed paraffin-embedded tissues, we can reliably and reproducibly identify very low-risk and very high-risk patients within SHH, Group 3, and Group 4 medulloblastomas. Conclusion Combining subgroup and cytogenetic biomarkers with established clinical biomarkers substantially improves patient prognostication, even in the context of heterogeneous clinical therapies. The prognostic significance of most molecular biomarkers is restricted to a specific subgroup. We have identified a small panel of cytogenetic biomarkers that reliably identifies very high-risk and very low-risk groups of patients, making it an excellent tool for selecting patients for therapy intensification and therapy de-escalation in future clinical trials. PMID

  1. A Glutathione-Nrf2-Thioredoxin Cross-Talk Ensures Keratinocyte Survival and Efficient Wound Repair

    PubMed Central

    Telorack, Michèle; Meyer, Michael; Ingold, Irina; Conrad, Marcus; Bloch, Wilhelm; Werner, Sabine

    2016-01-01

    The tripeptide glutathione is the most abundant cellular antioxidant with high medical relevance, and it is also required as a co-factor for various enzymes involved in the detoxification of reactive oxygen species and toxic compounds. However, its cell-type specific functions and its interaction with other cytoprotective molecules are largely unknown. Using a combination of mouse genetics, functional cell biology and pharmacology, we unraveled the function of glutathione in keratinocytes and its cross-talk with other antioxidant defense systems. Mice with keratinocyte-specific deficiency in glutamate cysteine ligase, which catalyzes the rate-limiting step in glutathione biosynthesis, showed a strong reduction in keratinocyte viability in vitro and in the skin in vivo. The cells died predominantly by apoptosis, but also showed features of ferroptosis and necroptosis. The increased cell death was associated with increased levels of reactive oxygen and nitrogen species, which caused DNA and mitochondrial damage. However, epidermal architecture, and even healing of excisional skin wounds were only mildly affected in the mutant mice. The cytoprotective transcription factor Nrf2 was strongly activated in glutathione-deficient keratinocytes, but additional loss of Nrf2 did not aggravate the phenotype, demonstrating that the cytoprotective effect of Nrf2 is glutathione dependent. However, we show that deficiency in glutathione biosynthesis is efficiently compensated in keratinocytes by the cysteine/cystine and thioredoxin systems. Therefore, our study highlights a remarkable antioxidant capacity of the epidermis that ensures skin integrity and efficient wound healing. PMID:26808544

  2. A Glutathione-Nrf2-Thioredoxin Cross-Talk Ensures Keratinocyte Survival and Efficient Wound Repair.

    PubMed

    Telorack, Michèle; Meyer, Michael; Ingold, Irina; Conrad, Marcus; Bloch, Wilhelm; Werner, Sabine

    2016-01-01

    The tripeptide glutathione is the most abundant cellular antioxidant with high medical relevance, and it is also required as a co-factor for various enzymes involved in the detoxification of reactive oxygen species and toxic compounds. However, its cell-type specific functions and its interaction with other cytoprotective molecules are largely unknown. Using a combination of mouse genetics, functional cell biology and pharmacology, we unraveled the function of glutathione in keratinocytes and its cross-talk with other antioxidant defense systems. Mice with keratinocyte-specific deficiency in glutamate cysteine ligase, which catalyzes the rate-limiting step in glutathione biosynthesis, showed a strong reduction in keratinocyte viability in vitro and in the skin in vivo. The cells died predominantly by apoptosis, but also showed features of ferroptosis and necroptosis. The increased cell death was associated with increased levels of reactive oxygen and nitrogen species, which caused DNA and mitochondrial damage. However, epidermal architecture, and even healing of excisional skin wounds were only mildly affected in the mutant mice. The cytoprotective transcription factor Nrf2 was strongly activated in glutathione-deficient keratinocytes, but additional loss of Nrf2 did not aggravate the phenotype, demonstrating that the cytoprotective effect of Nrf2 is glutathione dependent. However, we show that deficiency in glutathione biosynthesis is efficiently compensated in keratinocytes by the cysteine/cystine and thioredoxin systems. Therefore, our study highlights a remarkable antioxidant capacity of the epidermis that ensures skin integrity and efficient wound healing. PMID:26808544

  3. ATP-Dependent Chromatin Remodeling by Cockayne Syndrome Protein B and NAP1-Like Histone Chaperones Is Required for Efficient Transcription-Coupled DNA Repair

    PubMed Central

    Lake, Robert J.; Basheer, Asjad; Fan, Hua-Ying

    2013-01-01

    The Cockayne syndrome complementation group B (CSB) protein is essential for transcription-coupled DNA repair, and mutations in CSB are associated with Cockayne syndrome—a devastating disease with complex clinical features, including the appearance of premature aging, sun sensitivity, and numerous neurological and developmental defects. CSB belongs to the SWI2/SNF2 ATP–dependent chromatin remodeler family, but the extent to which CSB remodels chromatin and whether this activity is utilized in DNA repair is unknown. Here, we show that CSB repositions nucleosomes in an ATP–dependent manner in vitro and that this activity is greatly enhanced by the NAP1-like histone chaperones, which we identify as new CSB–binding partners. By mapping functional domains and analyzing CSB derivatives, we demonstrate that chromatin remodeling by the combined activities of CSB and the NAP1-like chaperones is required for efficient transcription-coupled DNA repair. Moreover, we show that chromatin remodeling and repair protein recruitment mediated by CSB are separable activities. The collaboration that we observed between CSB and the NAP1-like histone chaperones adds a new dimension to our understanding of the ways in which ATP–dependent chromatin remodelers and histone chaperones can regulate chromatin structure. Taken together, the results of this study offer new insights into the functions of chromatin remodeling by CSB in transcription-coupled DNA repair as well as the underlying mechanisms of Cockayne syndrome. PMID:23637612

  4. Meningocele repair

    MedlinePlus

    ... dysraphism repair; Meningomyelocele repair; Neural tube defect repair; Spina bifida repair ... a medical team with experience in children with spina bifida. Your baby will likely have an MRI (magnetic ...

  5. Efficiency of Base Excision Repair of Oxidative DNA Damage and Its Impact on the Risk of Colorectal Cancer in the Polish Population

    PubMed Central

    Kabzinski, J.; Mucha, B.; Cuchra, M.; Markiewicz, L.; Przybylowska, K.; Dziki, A.; Dziki, L.; Majsterek, I.

    2016-01-01

    DNA oxidative lesions are widely considered as a potential risk factor for colorectal cancer development. The aim of this work was to determine the role of the efficiency of base excision repair, both in lymphocytes and in epithelial tissue, in patients with CRC and healthy subjects. SNPs were identified within genes responsible for steps following glycosylase action in BER, and patients and healthy subjects were genotyped. A radioisotopic BER assay was used for assessing repair efficiency and TaqMan for genotyping. Decreased BER activity was observed in lymphocyte extract from CRC patients and in cancer tissue extract, compared to healthy subjects. In addition, polymorphisms of EXO1, LIG3, and PolB may modulate the risk of colorectal cancer by decreasing (PolB) or increasing (LIG3 and EXO1) the chance of malignant transformation. PMID:26649135

  6. Single-nucleotide polymorphisms of the Trypanosoma cruzi MSH2 gene support the existence of three phylogenetic lineages presenting differences in mismatch-repair efficiency.

    PubMed Central

    Augusto-Pinto, Luiz; Teixeira, Santuza M R; Pena, Sérgio D J; Machado, Carlos Renato

    2003-01-01

    We have identified single-nucleotide polymorphisms (SNPs) in the mismatch-repair gene TcMSH2 from Trypanosoma cruzi. Phylogenetic inferences based on the SNPs, confirmed by RFLP analysis of 32 strains, showed three distinct haplogroups, denominated A, B, and C. Haplogroups A and C presented strong identity with the previously described T. cruzi lineages I and II, respectively. A third haplogroup (B) was composed of strains presenting hybrid characteristics. All strains from a haplogroup encoded the same specific protein isoform, called, respectively, TcMHS2a, TcMHS2b, and TcMHS2c. The classification into haplogroups A, B, and C correlated with variation in the efficiency of mismatch repair in these cells. When microsatellite loci of strains representative of each haplogroup were analyzed after being cultured in the presence of hydrogen peroxide, new microsatellite alleles were definitely seen in haplogroups B and C, while no evidence of microsatellite instability was found in haplogroup A. Also, cells from haplogroups B and C were considerably more resistant to cisplatin treatment, a characteristic known to be conferred by deficiency of mismatch repair in eukaryotic cells. Altogether, our data suggest that strains belonging to haplogroups B and C may have decreased mismatch-repair ability when compared with strains assigned to the haplogroup A lineage. PMID:12750325

  7. Cytogenetic effects of hexavalent chromium in Bulgarian chromium platers.

    PubMed

    Benova, Donka; Hadjidekova, Valeria; Hristova, Rossitza; Nikolova, Teodora; Boulanova, Minka; Georgieva, Ivanka; Grigorova, Mira; Popov, Todor; Panev, Teodor; Georgieva, Rossitza; Natarajan, Adayapalam T; Darroudi, Firouz; Nilsson, Robert

    2002-02-15

    The aim of the present study was to evaluate the genotoxic effects of hexavalent chromium (Cr(VI)) in vivo in exposed Bulgarian chromium platers by using classical cytogenetic and molecular cytogenetic analyses of peripheral lymphocytes and exfoliated buccal cells. No significant difference was observed between the exposed workers and the controls with regard to the frequency of cells with chromosome aberrations (CAs) using conventional Giemsa staining and in the frequency of sister chromatid exchanges (SCEs). However, there was a significant increase in the number of cells with micronuclei (MN) in peripheral lymphocytes from chromium exposed workers as compared to the controls. In the buccal cells from these workers, this increase was even more pronounced. Cytosine arabinoside (AraC), an inhibitor of DNA synthesis and repair, was found to significantly increase the levels of MN in vitro in the lymphocytes of both groups. The increase was more expressed in the lymphocytes of chromium exposed workers. Both centromere positive (C(+)) as well as centromere negative (C(-)) MN were observed by the fluorescence in situ hybridization (FISH) technique in both of the cell types studied. No difference between C(+) and C(-) MN frequencies was found in the lymphocytes as well as in the buccal cells. Thus, Cr(VI) appears to have both clastogenic as well as aneugenic effects in humans. PMID:11815242

  8. Extremophilic Acinetobacter Strains from High-Altitude Lakes in Argentinean Puna: Remarkable UV-B Resistance and Efficient DNA Damage Repair

    NASA Astrophysics Data System (ADS)

    Albarracín, Virginia Helena; Pathak, Gopal P.; Douki, Thierry; Cadet, Jean; Borsarelli, Claudio Darío; Gärtner, Wolfgang; Farias, María Eugenia

    2012-06-01

    High-Altitude Andean Lakes (HAAL) of the South American Andes are almost unexplored ecosystems of shallow lakes. The HAAL are recognized by a remarkably high UV exposure, strong changes in temperature and salinity, and a high content of toxic elements, especially arsenic. Being exposed to remarkably extreme conditions, they have been classified as model systems for the study of life on other planets. Particularly, Acinetobacter strains isolated from the HAAL were studied for their survival competence under strong UV-B irradiation. Clinical isolates, Acinetobacter baumannii and Acinetobacter johnsonii, served as reference material. Whereas the reference strains rapidly lost viability under UV-B irradiation, most HAAL-derived strains readily survived this exposure and showed less change in cell number after the treatment. Controls for DNA repair activity, comparing dark repair (DR) or photo repair (PR), gave evidence for the involvement of photolyases in the DNA repair. Comparative measurements by HPLC-mass spectrometry detected the number of photoproducts: bipyrimidine dimers under both PR and DR treatments were more efficiently repaired in the HAAL strains (up to 85 % PR and 38 % DR) than in the controls (31 % PR and zero DR ability). Analysis of cosmid-cloned total genomic DNA from the most effective DNA-photorepair strain (Ver3) yielded a gene (HQ443199) encoding a protein with clear photolyase signatures belonging to class I CPD-photolyases. Despite the relatively low sequence similarity of 41 % between the enzymes from Ver3 and from E. coli (PDB 1DNPA), a model-building approach revealed a high structural homology to the CPD-photolyase of E. coli.

  9. Extremophilic Acinetobacter strains from high-altitude lakes in Argentinean Puna: remarkable UV-B resistance and efficient DNA damage repair.

    PubMed

    Albarracín, Virginia Helena; Pathak, Gopal P; Douki, Thierry; Cadet, Jean; Borsarelli, Claudio Darío; Gärtner, Wolfgang; Farias, María Eugenia

    2012-06-01

    High-Altitude Andean Lakes (HAAL) of the South American Andes are almost unexplored ecosystems of shallow lakes. The HAAL are recognized by a remarkably high UV exposure, strong changes in temperature and salinity, and a high content of toxic elements, especially arsenic. Being exposed to remarkably extreme conditions, they have been classified as model systems for the study of life on other planets. Particularly, Acinetobacter strains isolated from the HAAL were studied for their survival competence under strong UV-B irradiation. Clinical isolates, Acinetobacter baumannii and Acinetobacter johnsonii, served as reference material. Whereas the reference strains rapidly lost viability under UV-B irradiation, most HAAL-derived strains readily survived this exposure and showed less change in cell number after the treatment. Controls for DNA repair activity, comparing dark repair (DR) or photo repair (PR), gave evidence for the involvement of photolyases in the DNA repair. Comparative measurements by HPLC-mass spectrometry detected the number of photoproducts: bipyrimidine dimers under both PR and DR treatments were more efficiently repaired in the HAAL strains (up to 85 % PR and 38 % DR) than in the controls (31 % PR and zero DR ability). Analysis of cosmid-cloned total genomic DNA from the most effective DNA-photorepair strain (Ver3) yielded a gene (HQ443199) encoding a protein with clear photolyase signatures belonging to class I CPD-photolyases. Despite the relatively low sequence similarity of 41 % between the enzymes from Ver3 and from E. coli (PDB 1DNPA), a model-building approach revealed a high structural homology to the CPD-photolyase of E. coli. PMID:22644565

  10. Repairing the efficiency loss due to varying cluster sizes in two-level two-armed randomized trials with heterogeneous clustering.

    PubMed

    Candel, Math J J M; Van Breukelen, Gerard J P

    2016-05-30

    In two-armed trials with clustered observations the arms may differ in terms of (i) the intraclass correlation, (ii) the outcome variance, (iii) the average cluster size, and (iv) the number of clusters. For a linear mixed model analysis of the treatment effect, this paper examines the expected efficiency loss due to varying cluster sizes based upon the asymptotic relative efficiency of varying versus constant cluster sizes. Simple, but nearly cost-optimal, correction factors are derived for the numbers of clusters to repair this efficiency loss. In an extensive Monte Carlo simulation, the accuracy of the asymptotic relative efficiency and its Taylor approximation are examined for small sample sizes. Practical guidelines are derived to correct the numbers of clusters calculated under constant cluster sizes (within each treatment) when planning a study. Because of the variety of simulation conditions, these guidelines can be considered conservative but safe in many realistic situations. Copyright © 2016 John Wiley & Sons, Ltd. PMID:26756696

  11. DNA repair

    SciTech Connect

    Friedberg, E.C.; Hanawalt, P.C. )

    1988-01-01

    Topics covered in this book included: Eukaryote model systems for DNA repair study; Sensitive detection of DNA lesions and their repair; and Defined DNA sequence probes for analysis of mutagenesis and repair.

  12. Cytogenetic risk stratification in chronic myelomonocytic leukemia

    PubMed Central

    Such, Esperanza; Cervera, José; Costa, Dolors; Solé, Francesc; Vallespí, Teresa; Luño, Elisa; Collado, Rosa; Calasanz, María J.; Hernández-Rivas, Jesús M.; Cigudosa, Juan C.; Nomdedeu, Benet; Mallo, Mar; Carbonell, Felix; Bueno, Javier; Ardanaz, María T.; Ramos, Fernando; Tormo, Mar; Sancho-Tello, Reyes; del Cañizo, Consuelo; Gómez, Valle; Marco, Victor; Xicoy, Blanca; Bonanad, Santiago; Pedro, Carmen; Bernal, Teresa; Sanz, Guillermo F.

    2011-01-01

    Background The prognostic value of cytogenetic findings in chronic myelomonocytic leukemia is unclear. Our purpose was to evaluate the independent prognostic impact of cytogenetic abnormalities in a large series of patients with chronic myelomonocytic leukemia included in the database of the Spanish Registry of Myelodysplastic Syndromes. Design and Methods We studied 414 patients with chronic myelomonocytic leukemia according to WHO criteria and with a successful conventional cytogenetic analysis at diagnosis. Different patient and disease characteristics were examined by univariate and multivariate methods to establish their relationship with overall survival and evolution to acute myeloid leukemia. Results Patients with abnormal karyotype (110 patients, 27%) had poorer overall survival (P=0.001) and higher risk of acute myeloid leukemia evolution (P=0.010). Based on outcome analysis, three cytogenetic risk categories were identified: low risk (normal karyotype or loss of Y chromosome as a single anomaly), high risk (presence of trisomy 8 or abnormalities of chromosome 7, or complex karyotype), and intermediate risk (all other abnormalities). Overall survival at five years for patients in the low, intermediate, and high risk cytogenetic categories was 35%, 26%, and 4%, respectively (P<0.001). Multivariate analysis confirmed that this new CMML-specific cytogenetic risk stratification was an independent prognostic variable for overall survival (P=0.001). Additionally, patients belonging to the high-risk cytogenetic category also had a higher risk of acute myeloid leukemia evolution on univariate (P=0.001) but not multivariate analysis. Conclusions Cytogenetic findings have a strong prognostic impact in patients with chronic myelomonocytic leukemia. PMID:21109693

  13. Planning Maintenance and Repairs.

    ERIC Educational Resources Information Center

    Fitzemeyer, Ted

    2001-01-01

    Discusses the use of school facility design as an aid to efficiently repairing and maintaining facility systems. Also presents details on facility design's influence in properly maintaining mechanical and electrical systems. (GR)

  14. Significance of FISH in clinical cytogenetics

    SciTech Connect

    Gopal Rao, V.V.N.; Harris, S.; Roop, H.

    1994-09-01

    Ever since its discovery, FISH technology has become an invaluable adjunct to conventional cytogenetics. FISH has been instrumental in resolving previously unresolved cytogenetic dilemmas. FISH has been used to elucidate complex as well as subtle chromosomal translocations, in detection of microdeletions, to confirm duplications and inversions and to identify marker chromosomes. We report a few selected cases where FISH proved to be invaluable in not only confirming the anomaly, but also in arriving at an accurate diagnosis and appropriate counseling of the patients. These include 3 cases of prenatal and 3 cases of postnatal diagnosis. The results clearly demonstrate the significance of FISH in identifying and interpreting the difficult karyotype in clinical cytogenetics. In addition, FISH has been used to rule out microdeletions in Prader-Willi (16), Angelman (3), Miller-Dieker (7), DiGeorge (4) and Smith-Magenis (1) syndrome patients. Without FISH in the majority of these cases, it would not have been possible to accurately identify the karyotype and interpret the results. Hence, we recommend that FISH be used as a powerful adjunct to conventional cytogenetics in order to arrive at an accurate interpretation of the results but not to replace routine cytogenetic studies.

  15. Canine Cytogenetics - From band to basepair

    PubMed Central

    Breen, Matthew

    2008-01-01

    Humans and dogs have coexisted for thousands of years, during which time we have developed a unique bond, centered on companionship. Along the way, we have developed purebred dog breeds in a manner that has resulted unfortunately in many of them being affected by serious genetic disorders, including cancers. With serendipity and irony the unique genetic architecture of the 21st Century genome of Man's best friend may ultimately provide many of the keys to unlock some of nature's most intriguing biological puzzles. Canine cytogenetics has advanced significantly over the past 10 years, spurred on largely by the surge of interest in the dog as a biomedical model for genetic disease and the availability of advanced genomics resources. As such the role of canine cytogenetics has moved rapidly from one that served initially to define the gross genomic organization of the canine genome and provide a reliable means to determine the chromosomal location of individual genes, to one that enabled the assembled sequence of the canine genome to be anchored to the karyotype. Canine cytogenetics now presents the biomedical research community with a means to assist in our search for a greater understanding of how genome architectures altered during speciation and in our search for genes associated with cancers that affect both dogs and humans. The cytogenetics ‘toolbox’ for the dog is now loaded. This review aims to provide a summary of some of the recent advancements in canine cytogenetics. PMID:18467825

  16. Cytogenetic studies in ovarian cancer.

    PubMed

    Whang-Peng, J; Knutsen, T; Douglass, E C; Chu, E; Ozols, R F; Hogan, W M; Young, R C

    1984-01-01

    Cytogenetic studies of ovarian cancer have been conducted in the Medicine Branch, NCI, National Institutes of Health for 5 years. A total of 72 patients were studied by direct preparation and/or 1- to 3-day short-term culture of ascites (86 samples), pleural fluid (4 samples), and tumor (2 samples). Repeat examinations (1-24 months later) were performed in 7 of the 72 patients. Forty-four patients (62%) were successfully analyzed with banding techniques: 6 patients had adenocarcinoma, 7 had serous adenocarcinoma, 13 had serous papillary adenocarcinoma, 7 had serous papillary cystadenocarcinoma, 2 had mucinous adenocarcinoma, 6 had undifferentiated or poorly differentiated adenocarcinoma, 1 had clear cell adenocarcinoma, and 2 were not classified. Of these 44 patients, 29 had received prior chemotherapy, 14 were untreated, and in 1 patient the treatment status was unknown. Aneuploidy was observed in all patients and there was considerable variation in the chromosome numbers (even within single samples), often ranging from diploidy to triploidy to tetraploidy. All 44 patients had numerical abnormalities and 39 had structural abnormalities. The chromosomes most frequently involved in structural abnormalities (in decreasing order according to the number of patients involved) were #1, #3, #2, #4, #9, #10, #15, #19, #6, and #11; the least involved chromosomes were #21 and #5. Clone formation and the number of chromosomes involved in structural abnormalities increased with duration of disease and were more extensive in patients treated with chemotherapy than in patients treated with surgery alone. Our data did not show a deletion of chromosome #6 (6q-) to be specific for ovarian cancer. PMID:6690026

  17. 42 CFR 493.1225 - Condition: Clinical cytogenetics.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... Testing § 493.1225 Condition: Clinical cytogenetics. If the laboratory provides services in the specialty of Clinical cytogenetics, the laboratory must meet the requirements specified in §§ 493.1230 through... 42 Public Health 5 2010-10-01 2010-10-01 false Condition: Clinical cytogenetics. 493.1225...

  18. 42 CFR 493.1225 - Condition: Clinical cytogenetics.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 5 2011-10-01 2011-10-01 false Condition: Clinical cytogenetics. 493.1225 Section... Testing § 493.1225 Condition: Clinical cytogenetics. If the laboratory provides services in the specialty of Clinical cytogenetics, the laboratory must meet the requirements specified in §§ 493.1230...

  19. Clubfoot repair

    MedlinePlus

    ... release; Talipes equinovarus - repair; Tibialis anterior tendon transfer Images Clubfoot repair - series References Kelly DM. Congenital Anomalies ... provided herein should not be used during any medical emergency or for the diagnosis or treatment of ...

  20. Repairs of composite structures

    NASA Astrophysics Data System (ADS)

    Roh, Hee Seok

    Repair on damaged composite panels was conducted. To better understand adhesively bonded repair, the study investigates the effect of design parameters on the joint strength. The design parameters include bondline length, thickness of adherend and type of adhesive. Adhesives considered in this study were tested to measure their tensile material properties. Three types of adhesively bonded joints, single strap, double strap, and single lap joint were considered under changing bondline lengths, thickness of adherend and type of adhesive. Based on lessons learned from bonded joints, a one-sided patch repair method for composite structures was conducted. The composite patch was bonded to the damaged panel by either film adhesive FM-73M or paste adhesive EA-9394 and the residual strengths of the repaired specimens were compared under varying patch sizes. A new repair method using attachments has been suggested to enhance the residual strength. Results obtained through experiments were analyzed using finite element analysis to provide a better repair design and explain the experimental results. It was observed that the residual strength of the repaired specimen was affected by patch length. Method for rapid repairs of damaged composite structures was investigated. The damage was represented by a circular hole in a composite laminated plate. Pre-cured composite patches were bonded with a quick-curing commercial adhesive near (rather than over) the hole. Tensile tests were conducted on specimens repaired with various patch geometries. The test results showed that, among the methods investigated, the best repair method restored over 90% of the original strength of an undamaged panel. The interfacial stresses in the adhesive zone for different patches were calculated in order to understand the efficiencies of the designs of these patch repairs. It was found that the composite patch that yielded the best strength had the lowest interfacial peel stress between the patch and

  1. Combining Heavy Ion Radiation and Artificial MicroRNAs to Target the Homologous Recombination Repair Gene Efficiently Kills Human Tumor Cells

    SciTech Connect

    Zheng Zhiming; Wang Ping; Wang Hongyan; Zhang Xiangming; Wang Minli; Cucinotta, Francis A.; Wang Ya

    2013-02-01

    Purpose: Previously, we demonstrated that heavy ions kill more cells at the same dose than X-rays because DNA-clustered lesions produced by heavy ions affect nonhomologous end-joining (NHEJ) repair but not homologous recombination repair (HRR). We have also shown that our designed artificial microRNAs (amiRs) could efficiently target XRCC4 (an essential factor for NHEJ) or XRCC2 (an essential factor for HRR) and sensitize human tumor cells to X-rays. Based on these data, we were interested in testing the hypothesis that combining heavy ions and amiRs to target HRR but not NHEJ should more efficiently kill human tumor cells. Methods and Materials: Human tumor cell lines (U87MG, a brain tumor cell line, and A549, a lung cancer cell line) and their counterparts, overexpressed with amiR to target XRCC2, XRCC4 or both, were used in this study. Survival sensitivities were examined using a clonogenic assay after these cells were exposed to X-rays or heavy ions. In addition, these cell lines were subcutaneously injected into nude mice to form xenografts and the tumor size was compared after the tumor areas were exposed to X-rays or heavy ions. Results: Although targeting either XRCC4 (NHEJ factor) or XRCC2 (HRR factor) sensitized the human tumor cells to X-rays, in vitro and the xenograft animal model, targeting only XRCC2 but not XRCC4 sensitized the human tumor cells to heavy ions in vitro and in the xenograft animal model. Conclusions: Combining heavy ions with targeting the HRR pathway, but not the NHEJ pathway, could significantly improve the efficiency of tumor cell death.

  2. Efficient and Reliable Production of Vectors for the Study of the Repair, Mutagenesis, and Phenotypic Consequences of Defined DNA Damage Lesions in Mammalian Cells

    PubMed Central

    Petrova, Lucy; Gran, Christine; Bjoras, Magnar; Doetsch, Paul W.

    2016-01-01

    Mammalian cells are constantly and unavoidably exposed to DNA damage from endogenous and exogenous sources, frequently to the detriment of genomic integrity and biological function. Cells acquire a large number of chemically diverse lesions per day, and each can have a different genetic fate and biological consequences. However, our knowledge of how and when specific lesions are repaired or how they may compromise the fidelity of DNA replication or transcription and lead to deleterious biological endpoints in mammalian cells is limited. Studying individual lesions requires technically challenging approaches for the targeted introduction of defined lesions into relevant DNA sequences of interest. Here, we present a systematic analysis of factors influencing yield and an improved, efficient and reliable protocol for the production of mammalian expression phagemid vectors containing defined DNA base modifications in any sequence position of either complementary DNA strand. We applied our improved protocol to study the transcriptional mutagenesis-mediated phenotypic consequences of the common oxidative lesion 5-hydroxyuracil, placed in the G12 mutational hotspot of the KRAS oncogene. 5-OHU induced sustained oncogenic signaling in Neil1-/-Neil2-/- mouse cells. The resulting advance in technology will have broad applicability for investigation of single lesion DNA repair, mutagenesis, and DNA damage responses in mammalian cells. PMID:27362559

  3. The cytogenetics of mammalian autosomal rearrangements

    SciTech Connect

    Daniel, A.

    1988-01-01

    Combining data from animal and clinical studies with classical cytogenetic observations, the volume provides information on various aspects of mammalian autosomal rearrangements. Topics range from the reproductive consequences to carriers of autosomal rearrangements to the application of structural rearrangements and DNA probes to gene mapping. In addition, the book presents an overview of new perspectives and future directions for research.

  4. CYTOGENETIC EFFECTS OF PHOSPHINE INHALATION BY RODENTS

    EPA Science Inventory

    Phosphine (PH3) is a highly toxic grain fumigant that can be produced from the reaction of metal phosphides with water. o determine the in vivo cytogenetic effects of inhalation of PH3, male CD-1 mice were exposed to either 0, 5, 10, or 15 ppm target concentrations of PH3 for 6 h...

  5. Cytogenetic activity of the coumarin glucoside seseloside

    SciTech Connect

    Arshava, E.A.

    1986-05-01

    The cytogenetic effect of the coumarin glucoside seseloside on plant objects was studied. It was established that low concentrations of the preparation (from 1 x 10/sup -5/ to 1 x 10/sup -3/ ..mu..g/ml) inhibit both spontaneous and radiation-induced mutagenesis. The effect of high concentrations (10 and 100 ..mu..g/ml) causes a mutagenic effect.

  6. Rapid road repair vehicle

    DOEpatents

    Mara, Leo M.

    1999-01-01

    Disclosed are improvments to a rapid road repair vehicle comprising an improved cleaning device arrangement, two dispensing arrays for filling defects more rapidly and efficiently, an array of pre-heaters to heat the road way surface in order to help the repair material better bond to the repaired surface, a means for detecting, measuring, and computing the number, location and volume of each of the detected surface imperfection, and a computer means schema for controlling the operation of the plurality of vehicle subsystems. The improved vehicle is, therefore, better able to perform its intended function of filling surface imperfections while moving over those surfaces at near normal traffic speeds.

  7. A comparative study on the cytogenetic activity of three benzodiazepines in vitro.

    PubMed

    Ekonomopoulou, Maria T; Akritopoulou, Kyriaki; Mourelatos, Constantine; Iakovidou-Kritsi, Zafiroula

    2011-06-01

    Even though benzodiazepines (BDZs) possess a leading place among drugs used as anxiolytics, sedatives, muscle relaxants, and anticonvulsants, their cytogenetic effects have not been widely studied in humans. Alprazolam (AZ), bromazepam (BZ), diazepam, and lorazepam (LZ) are some of the most commonly prescribed BDZs. Previous positive findings on diazepam's cytogenetic effects in human lymphocytes suggested additional investigation. In the present research, we explored the cytogenetic potential of AZ, BZ, and LZ in human lymphocyte cultures, using an expanded sample set, administering the under-investigation medications at final concentrations equivalent to oral dosage. As a biomarker of genotoxicity we used sister chromatid exchanges, one of the most sensitive methods reflecting DNA damage and/or subsequent DNA repair, and as a marker of cytostaticity we estimated the proliferation rate index. After 72 h of incubation in the cultures, all three BDZs caused a concentration-dependent, statistically significant increase of sister chromatid exchange frequency (p < 0.001) followed by a statistically significant decrease of proliferation rate index (p < 0.001) of lymphocytes. Our conclusive results suggest that AZ, BZ, and LZ, at concentrations equivalent to oral doses, exhibit statistically significant genotoxicity in human lymphocyte cultures. PMID:21265625

  8. Protein Dynamics Control the Progression and Efficiency of the Catalytic Reaction Cycle of the Escherichia coli DNA-Repair Enzyme AlkB*

    PubMed Central

    Ergel, Burçe; Gill, Michelle L.; Brown, Lewis; Yu, Bomina; Palmer, Arthur G.; Hunt, John F.

    2014-01-01

    A central goal of enzymology is to understand the physicochemical mechanisms that enable proteins to catalyze complex chemical reactions with high efficiency. Recent methodological advances enable the contribution of protein dynamics to enzyme efficiency to be explored more deeply. Here, we utilize enzymological and biophysical studies, including NMR measurements of conformational dynamics, to develop a quantitative mechanistic scheme for the DNA repair enzyme AlkB. Like other iron/2-oxoglutarate-dependent dioxygenases, AlkB employs a two-step mechanism in which oxidation of 2-oxoglutarate generates a highly reactive enzyme-bound oxyferryl intermediate that, in the case of AlkB, slowly hydroxylates an alkylated nucleobase. Our results demonstrate that a microsecond-to-millisecond time scale conformational transition facilitates the proper sequential order of substrate binding to AlkB. Mutations altering the dynamics of this transition allow generation of the oxyferryl intermediate but promote its premature quenching by solvent, which uncouples 2-oxoglutarate turnover from nucleobase oxidation. Therefore, efficient catalysis by AlkB depends upon the dynamics of a specific conformational transition, establishing another paradigm for the control of enzyme function by protein dynamics. PMID:25043760

  9. The history of human cytogenetics in India-A review.

    PubMed

    Dutta, Usha R

    2016-09-10

    It is 60years since the discovery of the correct number of chromosomes in 1956; the field of cytogenetics had evolved. The late evolution of this field with respect to other fields is primarily due to the underdevelopment of lenses and imaging techniques. With the advent of the new technologies, especially automation and evolution of advanced compound microscopes, cytogenetics drastically leaped further to greater heights. This review describes the historic events that had led to the development of human cytogenetics with a special attention about the history of cytogenetics in India, its present status, and future. Apparently, this review provides a brief account into the insights of the early laboratory establishments, funding, and the German collaborations. The details of the Indian cytogeneticists establishing their labs, promoting the field, and offering the chromosomal diagnostic services are described. The detailed study of chromosomes helps in increasing the knowledge of the chromosome structure and function. The delineation of the chromosomal rearrangements using cytogenetics and molecular cytogenetic techniques pays way in identifying the molecular mechanisms involved in the chromosomal rearrangement. Although molecular cytogenetics is greatly developing, the conventional cytogenetics still remains the gold standard in the diagnosis of various numerical chromosomal aberrations and a few structural aberrations. The history of cytogenetics and its importance even in the era of molecular cytogenetics are discussed. PMID:26850130

  10. The Fanconi anemia pathway is required for efficient repair of stress-induced DNA damage in haematopoietic stem cells

    PubMed Central

    Kaschutnig, Paul; Bogeska, Ruzhica; Walter, Dagmar; Lier, Amelie; Huntscha, Sina; Milsom, Michael D

    2015-01-01

    Within regenerating tissues, aging is characterized by a progressive general deterioration of organ function, thought to be driven by the gradual depletion of functional adult stem cells. Although there are probably multifactorial mechanisms that result in compromized stem cell functionality with advancing age, the accumulation of DNA damage within the stem cell compartment is likely to make a major contribution to this process. However, the physiologic source of DNA damage within the different tissue specific stem cell compartments remains to be determined, as does the fate of stem cells exposed to such damage. Using the haematopoietic system as a model organ, we have recently shown that certain forms of physiologic stress, such as infection-associated inflammation and extensive blood loss, leads to the induction of biologically relevant levels of DNA damage in haematopoietic stem cells (HSCs) by dramatically increasing the proliferative index of this normally quiescent cell population.1 We were also able to demonstrate that such stress-associated DNA damage was sufficient to completely deplete HSCs and promote severe aplastic anemia (SAA) in the Fanconi anemia (FA) knockout mouse model, which has compromized replication-associated DNA repair. In this “Extra Views” article, we extend this previous work to show that FA mice do not spontaneously develop a haematopoietic phenotype consistent with SAA, even at extreme old age. This suggests that HSC quiescence restricts the acquisition of DNA damage during aging and preserves the functional integrity of the stem cell pool. In line with this hypothesis, we provide an extended time course analysis of the response of FA knockout mice to chronic inflammatory stress and show that enforced HSC proliferation leads to a highly penetrant SAA phenotype, which closely resembles the progression of the disease in FA patients. PMID:26178207

  11. Detection of recurrent cytogenetic aberrations in multiple myeloma: A comparison between MLPA and iFISH

    PubMed Central

    Yu, Zhen; Li, Fei; Yi, Shuhua; Ai, Xiaofei; Qin, Xiaoqi; Feng, Xiaoyan; Zhou, Wen; Xu, Yan; Li, Zengjun; Hao, Mu; Sui, Weiwei; Deng, Shuhui; Acharya, Chirag; Zhao, Yaozhong; Ru, Kun; Qiu, Lugui; An, Gang

    2015-01-01

    Multiple myeloma (MM) is a genetically heterogeneous disease with diverse clinical characteristics and outcomes. Recently, multiplex ligation-dependent probe amplification (MLPA) has emerged as an effective and robust method for the detection of cytogenetic aberrations in MM patients. In the present study, MLPA analysis was applied to analyze cytogenetics of CD138 tumor cells of 59 MM samples, and its result was compared, retrospectively, with the interphase fluorescence in situ hybridization (iFISH) data. We firstly established the normal range of each of the 42 diagnostic probes using healthy donor samples. A total of 151 aberrations were detected in 59 patient samples, and 49/59 cases (83.1%) harbored at least one copy number variation. Overall, 0–7 aberrations were detected per case using MLPA, indicating the heterogeneity and complexity of MM cytogenetics. We showed the high efficiency of MLPA and the high congruency of the two methods to assess cytogenetic aberrations. Considering that MLPA analysis is not reliable when the aberration only exits in a small population of tumor cells, it is essential to use both MLPA and iFISH as complementary techniques for the diagnosis of MM. PMID:26416457

  12. Cytogenetic Findings in Mentally Retarded Iranian Patients

    PubMed Central

    Nasiri, F; Mahjoubi, F; Manouchehry, F; Razazian, F; Mortezapour, F; Rahnama, M

    2012-01-01

    We conducted a cytogenetic study on 865 individuals with idiopathic mental retardation (MR) who were admitted to the Cytogenetics Department of the Iran Blood Transfusion Organisation (IBTO) Research Centre, Tehran, Iran; these were performed on blood samples using conventional staining methods. Chromosome anomalies were identified in 205 of the patients (23.6%). The majority were Down’s syndrome cases (n = 138). In 33 males, a positive fragile X anomaly was found. The remainder (n = 34) had other chromosomal abnormalities including structural chromosome aberrations (n = 23), marker chromosomes with an unknown origin (n = 3), sex chromosome aneuploidy (n = 6) and trisomy 18 (n = 2). The contribution of chromosome aberrations to the cause of MR in this group of patients is discussed. PMID:24052729

  13. Cytogenetic abnormalities in acute leukaemia of ambiguous lineage: an overview.

    PubMed

    Manola, Kalliopi N

    2013-10-01

    Acute leukaemia of ambiguous lineage (ALAL) is a rare complex entity with heterogeneous clinical, immunophenotypic, cytogenetic and molecular genetic features and adverse outcome. According to World Health Organization 2008 classification, ALAL encompasses those leukaemias that show no clear evidence of differentiation along a single lineage. The rarity of ALAL and the lack of uniform diagnostic criteria have made it difficult to establish its cytogenetic features, although cytogenetic analysis reveals clonal chromosomal abnormalities in 59-91% of patients. This article focuses on the significance of cytogenetic analysis in ALAL supporting the importance of cytogenetic analysis in the pathogenesis, diagnosis, prognosis, follow up and treatment selection of ALAL. It reviews in detail the types of chromosomal aberrations, their molecular background, their correlation with immunophenotype and age distribution and their prognostic relevance. It also summarizes some novel chromosome aberrations that have been observed only once. Furthermore, it highlights the ongoing and future research on ALAL in the field of cytogenetics. PMID:23888868

  14. Comparative genomic hybridization in clinical cytogenetics

    SciTech Connect

    Bryndorf, T.; Kirchhoff, M.; Rose, H.

    1995-11-01

    We report the results of applying comparative genomic hybridization (CGH) in a cytogenetic service laboratory for (1) determination of the origin of extra and missing chromosomal material in intricate cases of unbalanced aberrations and (2) detection of common prenatal numerical chromosome aberrations. A total of 11 fetal samples were analyzed. Seven cases of complex unbalanced aberrations that could not be identified reliably by conventional cytogenetics were successfully resolved by CGH analysis. CGH results were validated by using FISH with chromosome-specific probes. Four cases representing common prenatal numerical aberrations (trisomy 21, 18, and 13 and monosomy X) were also successfully diagnosed by CGH. We conclude that CGH is a powerful adjunct to traditional cytogenetic techniques that makes it possible to solve clinical cases of intricate unbalanced aberrations in a single hybridization. CGH may also be a useful adjunct to screen for euchromatic involvement in marker chromosomes. Further technical development may render CGH applicable for routine aberration screening. 16 refs., 4 figs., 2 tabs.

  15. Photochromic Bacteriorhodopsin Mutant with High Holographic Efficiency and Enhanced Stability via a Putative Self-Repair Mechanism

    PubMed Central

    2015-01-01

    The Q photoproduct of bacteriorhodopsin (BR) is the basis of several biophotonic technologies that employ BR as the photoactive element. Several blue BR (bBR) mutants, generated by using directed evolution, were investigated with respect to the photochemical formation of the Q state. We report here a new bBR mutant, D85E/D96Q, which is capable of efficiently converting the entire sample to and from the Q photoproduct. At pH 8.5, where Q formation is optimal, the Q photoproduct requires 65 kJ mol-1 of amber light irradiation (590 nm) for formation and 5 kJ mol-1 of blue light (450 nm) for reversion, respectively. The melting temperature of the resting state and Q photoproduct, measured via differential scanning calorimetry, is observed at 100 °C and 89 °C at pH 8.5 or 91 °C and 82 °C at pH 9.5, respectively. We hypothesize that the protein stability of D85E/D96Q compared to other blue mutants is associated with a rapid equilibrium between the blue form E85(H) and the purple form E85(−) of the protein, the latter providing enhanced structural stability. Additionally, the protein is shown to be stable and functional when suspended in an acrylamide matrix at alkaline pH. Real-time photoconversion to and from the Q state is also demonstrated with the immobilized protein. Finally, the holographic efficiency of an ideal thin film using the Q state of D85E/D96Q is calculated to be 16.7%, which is significantly better than that provided by native BR (6–8%) and presents the highest efficiency of any BR mutant to date. PMID:24498928

  16. 42 CFR 493.1276 - Standard: Clinical cytogenetics.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 5 2011-10-01 2011-10-01 false Standard: Clinical cytogenetics. 493.1276 Section... Testing Analytic Systems § 493.1276 Standard: Clinical cytogenetics. (a) The laboratory must have policies... study required based on the clinical information provided to the laboratory. (3) An adequate number...

  17. Gastroschisis repair

    MedlinePlus

    ... and surgery in general are: Allergic reactions to medicines Breathing problems Bleeding Infection Risks for gastroschisis repair are: Breathing problems if the baby's belly area (abdominal space) is smaller than normal. The baby may need ...

  18. Hydrocele repair

    MedlinePlus

    ... is excellent. However, another hydrocele may form over time, or if there was also a hernia present. Alternative Names Hydrocelectomy Images Hydrocele repair - series References Aiken JJ, Oldham KT. Inguinal hernias. In: ...

  19. Cytogenetic findings in a large bowel adenocarcinoma.

    PubMed

    Ferti-Passantonopoulou, A; Panani, A; Avgerinos, A; Raptis, S

    1986-04-15

    Cytogenetic analysis of a biopsy specimen taken during sigmoidoscopy from an adenocarcinoma of the large bowel revealed a hypodiploid karyotype with numerical and structural abnormalities identified as trisomy 7, t(3;12), t(1;17), interstitial deletion of the long arm of a chromosome #5 and loss of the Y chromosome with double X chromosomes. The possibility of this karyotype being a further evolutionary step in a subgroup of large bowel cancers and the clinical value of the above findings are discussed. PMID:3456826

  20. Interphase cytogenetics of workers exposed to benzene

    SciTech Connect

    Zhang, L.; Wang, Yunxia; Venkatesh, P.

    1996-12-01

    Fluorescence in situ hybridization (FISH) is a powerful new technique that allows numerical chromosome aberrations (aneuploidy) to be detected in interphase cells. In previous studies, FISH has been used to demonstrate that the benzene metabolites hydroquinone and 1,2,4-benzenetriol induce aneuploidy of chromosomes 7 and 9 in cultures of human cells. In the present study, we used an interphase FISH procedure to perform cytogenetic analyses on the blood cells of 43 workers exposed to benzene (median=31 ppm, 8-hr time-weighted average) and 44 matched controls from Shanghai, China. High benzene exposure (>31 ppm, n=22) increased the hyperdiploid frequency of chromosome 9 (p<0.01), but lower exposure (<31 ppm, n=21) did not. Trisomy 9 was the major form of benzene-induced hyperdiploidy. The level of hyperdiploidy in exposed workers correlated with their urinary phenol level (r= 0.58, p < 0.0001), a measure of internal benzene close. A significant correlation was also found between hyperdiploicly and decreased absolute lymphocyte count, an indicator of benzene hematotoxicity, in the exposed group (r=-0.44, p=0.003) but not in controls (r=-0.09, P=0.58). These results show that high benzene exposure induces aneuploidy of chromosome 9 in nondiseased individuals, with trisomy being the most prevalent form. They further highlight the usefulness of interphase cytogenetics and FISH for the rapid and sensitive detection of aneuploidy in exposed human populations. 35 refs., 3 figs., 2 tabs.

  1. Molecular cytogenetics using fluorescence in situ hybridization

    SciTech Connect

    Gray, J.W.; Kuo, Wen-Lin; Lucas, J.; Pinkel, D.; Weier, H-U.; Yu, Loh-Chung.

    1990-12-07

    Fluorescence in situ hybridization (FISH) with chromosome-specific probes enables several new areas of cytogenetic investigation by allowing visual determination of the presence and normality of specific genetic sequences in single metaphase or interphase cells. in this approach, termed molecular cytogenetics, the genetic loci to be analyzed are made microscopically visible in single cells using in situ hybridization with nucleic acid probes specific to these loci. To accomplish this, the DNA in the target cells is made single stranded by thermal denaturation and incubated with single-stranded, chemically modified probe under conditions where the probe will anneal only with DNA sequences to which it has high DNA sequence homology. The bound probe is then made visible by treatment with a fluorescent reagent such as fluorescein that binds to the chemical modification carried by the probe. The DNA to which the probe does not bind is made visible by staining with a dye such as propidium iodide that fluoresces at a wavelength different from that of the reagent used for probe visualization. We show in this report that probes are now available that make this technique useful for biological dosimetry, prenatal diagnosis and cancer biology. 31 refs., 3 figs.

  2. Cytogenetic analysis of lymphocytes from fiberglass-reinforced plastics workers occupationally exposed to styrene.

    PubMed

    Van Hummelen, P; Severi, M; Pauwels, W; Roosels, D; Veulemans, H; Kirsch-Volders, M

    1994-10-01

    In this study a group of 52 workers employed in a plant manufacturing fiberglass-reinforced plastic (FRP) pipes and cisterns, and therefore daily exposed to styrene, were monitored. As a control group 24 non-exposed workers from another factory producing and repairing pallets volunteered to participate. The airborne styrene during the monitoring ranged from 2.2 to 110.1 mg/m3. As a metabolic marker for styrene exposure mandelic acid was measured in the urine and ranged from 11 to 649 mg/g creatinine. From 43 exposed and 15 control workers sister-chromatid exchanges (SCE) and high frequency cell (HFC) data and from 49 exposed and 23 control workers micronucleus (MN) data from peripheral lymphocytes are reported. Although the two groups of workers could clearly be distinguished on the basis of the airborne styrene concentrations and urinary mandelic acid concentrations no differences in any of the cytogenetic markers were found. Correlations between the cytogenetic data and the level of airborne styrene concentrations or urinary mandelic acid levels could also not be demonstrated. Otherwise, smoking increased the SCE frequency. Grouping the workers according to smoking habits showed a statistically significant difference in SCE. Moreover, levels of urinary thiocyanate (SCN), which can be used as a metabolic marker for smoking, showed a significant positive correlation with the number of SCE. This indicates that SCE is a sensitive biomarker and might still be useful in biomonitoring. However, only chronic exposures over a long period would probably be detectable. In this study, where exposure was rather low and the number of working years was small (mean of 2.9 years), cytogenetic effects are probably too low or rare to be detectable with any assay. PMID:7523881

  3. Tissue repair

    PubMed Central

    2010-01-01

    As living beings that encounter every kind of traumatic event from paper cut to myocardial infarction, we must possess ways to heal damaged tissues. While some animals are able to regrow complete body parts following injury (such as the earthworm who grows a new head following bisection), humans are sadly incapable of such feats. Our means of recovery following tissue damage consists largely of repair rather than pure regeneration. Thousands of times in our lives, a meticulously scripted but unseen wound healing drama plays, with cells serving as actors, extracellular matrix as the setting and growth factors as the means of communication. This article briefly reviews the cells involved in tissue repair, their signaling and proliferation mechanisms and the function of the extracellular matrix, then presents the actors and script for the three acts of the tissue repair drama. PMID:21220961

  4. Updates on the cytogenetics and molecular cytogenetics of benign and intermediate soft tissue tumors

    PubMed Central

    NISHIO, JUN

    2013-01-01

    Soft tissue tumors are classified according to their histological resemblance to normal adult tissues and can be grouped into the following categories based on metastatic potential: benign, intermediate (locally aggressive), intermediate (rarely metastasizing) and malignant. Over the past two decades, considerable progress has been made in our understanding of the genetic background of soft tissue tumors. Traditional laboratory techniques, such as cytogenetic analysis and fluorescence in situ hybridization (FISH), can be used for diagnostic purposes in soft tissue pathology practice. Moreover, cytogenetic and molecular studies are often necessary for prognostics and follow-up of soft tissue sarcoma patients. This review provides updated information on the applicability of laboratory genetic testing in the diagnosis of benign and intermediate soft tissue tumors. These tumors include nodular fasciitis, chondroid lipoma, collagenous fibroma (desmoplastic fibroblastoma), giant cell tumor of tendon sheath (GCTTS)/pigmented villonodular synovitis (PVNS), angiofibroma of soft tissue, myxoinflammatory fibroblastic sarcoma (MIFS) and ossifying fibromyxoid tumor (OFMT). PMID:23255885

  5. No cytogenetic effects of quinolone treatment in humans.

    PubMed Central

    Mitelman, F; Kolnig, A M; Strömbeck, B; Norrby, R; Kromann-Andersen, B; Sommer, P; Wadstein, J

    1988-01-01

    Cytogenetic effects of ciprofloxacin (500 to 2,000 mg daily) and ofloxacin (200 mg daily) were studied in lymphocytes from 31 patients treated for 1 to 10 weeks. Blood samples for cytogenetic analysis were taken before the start of treatment from all patients, after 1 week from 25 patients, and after 2, 4, 6, and 10 weeks from six patients. No chromosome-damaging effect could be demonstrated in any treatment group. The mean aberration yields for each cytogenetic parameter studied and the total number of aberrations were all normal at each sampling occasion. PMID:3166361

  6. Molecular Cytogenetic Mapping of Satellite DNA Sequences in Aegilops geniculata and Wheat.

    PubMed

    Koo, Dal-Hoe; Tiwari, Vijay K; Hřibová, Eva; Doležel, Jaroslav; Friebe, Bernd; Gill, Bikram S

    2016-01-01

    Fluorescence in situ hybridization (FISH) provides an efficient system for cytogenetic analysis of wild relatives of wheat for individual chromosome identification, elucidation of homoeologous relationships, and for monitoring alien gene transfers into wheat. This study is aimed at developing cytogenetic markers for chromosome identification of wheat and Aegilops geniculata (2n = 4x = 28, UgUgMgMg) using satellite DNAs obtained from flow-sorted chromosome 5Mg. FISH was performed to localize the satellite DNAs on chromosomes of wheat and selected Aegilops species. The FISH signals for satellite DNAs on chromosome 5Mg were generally associated with constitutive heterochromatin regions corresponding to C-band-positive chromatin including telomeric, pericentromeric, centromeric, and interstitial regions of all the 14 chromosome pairs of Ae. geniculata. Most satellite DNAs also generated FISH signals on wheat chromosomes and provided diagnostic chromosome arm-specific cytogenetic markers that significantly improved chromosome identification in wheat. The newly identified satellite DNA CL36 produced localized Mg genome chromosome-specific FISH signals in Ae. geniculata and in the M genome of the putative diploid donor species Ae. comosa subsp. subventricosa but not in Ae. comosa subsp. comosa, suggesting that the Mg genome of Ae. geniculata was probably derived from subsp. subventricosa. PMID:27403741

  7. Outboard Repair.

    ERIC Educational Resources Information Center

    Hardway, Jack

    This consortium-developed instructor's manual for small engine repair (with focus on outboard motors) consists of the following nine instructional units: electrical remote control assembly, mechanical remote control assembly, tilt assemblies, exhaust housing, propeller and trim tabs, cooling system, mechanical gearcase, electrical gearcase, and…

  8. Snowmobile Repair.

    ERIC Educational Resources Information Center

    Helbling, Wayne

    This guide is designed to provide and/or improve instruction for occupational training in the area of snowmobile repair, and includes eight areas. Each area consists of one or more units of instruction, with each instructional unit including some or all of the following basic components: Performance objectives, suggested activities for teacher and…

  9. Motorcycle Repair.

    ERIC Educational Resources Information Center

    Hein, Jim; Bundy, Mike

    This motorcycle repair curriculum guide contains the following ten areas of study: brake systems, clutches, constant mesh transmissions, final drives, suspension, mechanical starting mechanisms, electrical systems, fuel systems, lubrication systems, and overhead camshafts. Each area consists of one or more units of instruction. Each instructional…

  10. Hydrocele repair

    MedlinePlus

    ... small surgical cut in the fold of the groin, and then drains the fluid. The sac (hydrocele) holding the fluid may be removed. The surgeon strengthens the muscle wall with stitches. This is called a hernia repair. Sometimes the surgeon uses a laparoscope to do ...

  11. Increasing role of cytogenetics in pediatric practice.

    PubMed

    Dayakar, Seetha; Rani, Didala Swaroopa; Babu, Sidam Jangu; Srilatha, Komanduri; Jayanthi, Undamatla; Goud, Kalal Iravathy; Jain, Dharmendra; Raina, Vimarsh

    2010-04-01

    Karyotyping was done in 100 children suspected of having chromosomal abnormalities of genetically uncertain syndromes, multiple congenital anomalies, short stature, dysmorphic features, unclassified mental retardation, and Down syndrome. A total of 56 patients had an abnormal karyotype: ring chromosome of 13 was seen in 1 patient (1.78%), and trisomy 21 was seen in 29 patients (51.78%) who were diagnosed as Down syndrome patients. Among them, 9 were male patients (31.03%) (47,XY+21) and 18 were female patients (47,XX+21) (62.06%); 2 patients showed 47,XY+21/46,XY (mosaicism) (6.89%). Chromosomal rearrangements involving chromosome numbers 13, 14, and 21 were seen in three patients. Among them, one patient had t(13;21) [45,XX,t(13;21)] and two patients had 45,XY,t(14;21). Trisomy 22 was seen in three patients (5.3%), marker chromosome was seen in two patients (3.57%), 46,XY,16qh variant was seen in one patient (1.78%), 46,XX,der(2) was seen in one patient (1.78%), 46,XX,14ps+ was seen in two patients (3.57%), and 46,XY,r(18) was seen in three patients (5.37%). Apart from this, 11 patients (19.64%) had sex chromosome aberrations: 45,XO was seen in 3 patients (27.7%), 4 patients were mosaic for Turner syndrome (45,XO/46,XX) (36.36%), and 4 patients had 46,Xi(Xp) (36.36%), and the remaining 44 patients had normal karyotypes. All of them showed phenotypic-cytogenetic heterogeneity. These findings suggest that cytogenetic analysis is useful in the investigation of children with genetic disorders of unknown origin to confirm clinical diagnosis and to allow for proper genetic counseling. PMID:20384456

  12. Mosaic Turner syndrome: cytogenetics versus FISH.

    PubMed

    Abulhasan, S J; Tayel, S M; al-Awadi, S A

    1999-05-01

    Twenty-two cases with Turner syndrome features were subjected to standard cytogenetic techniques using giemsa trypsin (GTG-) banding then fluorescence in situ hybridization (FISH) using a specific whole-X chromosome painting probe, Quint-Essential Y-specific DNA probe (AMELY) for Yp11.2, alpha-satellite (DYZ3) probe and X/Y cocktail-alpha satellite probe (ONCOR) for confirmation of the initial diagnosis and comparison of the two techniques. Eight cases (36%) showed the same karyotype results by both techniques [5 cases: 45,X/46,XX, 2 cases: 45,X/46,X,i(Xq) and one case with a triple cell line 45,X/46,XX/47,XXX]. In the other 14 cases (64%) the FISH technique has identified a third cell line in 7 cases (32%), delineated the origin of the marker in 5 cases (23%) to be derivative X and clarified the deletion of the Yp11.2 region in 2 cases (9%) with the 45,X/46,XY karyotype. The application of FISH has highlighted the differences between the initial diagnosis based on the standard cytogenetic technique and the final diagnosis determined by the application of DNA probes specific for the X and Y chromosomes. FISH proved useful in detection of the low frequency cell lines which need analysis of a large number of metaphase spreads by GTG-banding, helped in identifying the nature and the origin of the unknown markers which has an important implication in the development of gonadal tumours and delineated the deletion of the Yp11.2 region in the 45,X/46,XY Turner patients. PMID:10738532

  13. Bladder exstrophy repair

    MedlinePlus

    Bladder birth defect repair; Everted bladder repair; Exposed bladder repair; Repair of bladder exstrophy ... in boys and is often linked to other birth defects. Surgery is necessary to: Allow the child to ...

  14. Turbine repair process, repaired coating, and repaired turbine component

    DOEpatents

    Das, Rupak; Delvaux, John McConnell; Garcia-Crespo, Andres Jose

    2015-11-03

    A turbine repair process, a repaired coating, and a repaired turbine component are disclosed. The turbine repair process includes providing a turbine component having a higher-pressure region and a lower-pressure region, introducing particles into the higher-pressure region, and at least partially repairing an opening between the higher-pressure region and the lower-pressure region with at least one of the particles to form a repaired turbine component. The repaired coating includes a silicon material, a ceramic matrix composite material, and a repaired region having the silicon material deposited on and surrounded by the ceramic matrix composite material. The repaired turbine component a ceramic matrix composite layer and a repaired region having silicon material deposited on and surrounded by the ceramic matrix composite material.

  15. Analytical cytology applied to detection of induced cytogenetic abnormalities

    SciTech Connect

    Gray, J.W.; Lucas, J.; Straume, T.; Pinkel, D.

    1987-08-06

    Radiation-induced biological damage results in formation of a broad spectrum of cytogenetic changes such as translocations, dicentrics, ring chromosomes, and acentric fragments. A battery of analytical cytologic techniques are now emerging that promise to significantly improve the precision and ease with which these radiation induced cytogenetic changes can be quantified. This report summarizes techniques to facilitate analysis of the frequency of occurrence of structural and numerical aberrations in control and irradiated human cells. 14 refs., 2 figs.

  16. An opportune life: 50 years in human cytogenetics.

    PubMed

    Jacobs, Patricia A

    2014-01-01

    This article is one person's view of human cytogenetics over the past 50 years. The flowering of human cytogenetics led the way to the establishment of clinical genetics as one of the most important developments in medicine in the twentieth century. The article is written from the viewpoint of a scientist who never tired of analyzing the images of dividing cells on the light microscope and interpreting the wealth of information contained in them. PMID:25184528

  17. Development and application of camelid molecular cytogenetic tools.

    PubMed

    Avila, Felipe; Das, Pranab J; Kutzler, Michelle; Owens, Elaine; Perelman, Polina; Rubes, Jiri; Hornak, Miroslav; Johnson, Warren E; Raudsepp, Terje

    2014-01-01

    Cytogenetic chromosome maps offer molecular tools for genome analysis and clinical cytogenetics and are of particular importance for species with difficult karyotypes, such as camelids (2n = 74). Building on the available human-camel zoo-fluorescence in situ hybridization (FISH) data, we developed the first cytogenetic map for the alpaca (Lama pacos, LPA) genome by isolating and identifying 151 alpaca bacterial artificial chromosome (BAC) clones corresponding to 44 specific genes. The genes were mapped by FISH to 31 alpaca autosomes and the sex chromosomes; 11 chromosomes had 2 markers, which were ordered by dual-color FISH. The STS gene mapped to Xpter/Ypter, demarcating the pseudoautosomal region, whereas no markers were assigned to chromosomes 14, 21, 22, 28, and 36. The chromosome-specific markers were applied in clinical cytogenetics to identify LPA20, the major histocompatibility complex (MHC)-carrying chromosome, as a part of an autosomal translocation in a sterile male llama (Lama glama, LGL; 2n = 73,XY). FISH with LPAX BACs and LPA36 paints, as well as comparative genomic hybridization, were also used to investigate the origin of the minute chromosome, an abnormally small LPA36 in infertile female alpacas. This collection of cytogenetically mapped markers represents a new tool for camelid clinical cytogenetics and has applications for the improvement of the alpaca genome map and sequence assembly. PMID:23109720

  18. Meniscal Repair

    PubMed Central

    Yoon, Kyoung Ho

    2014-01-01

    The meniscus has several important roles, such as transmission of the load, absorption of the shock in the knee joint, acting as a secondary anteroposterior stabilizer of the knee joint, and contributing to proprioception of the knee joint. Degenerative changes of the knee joint develop in the long-term follow-up even after partial meniscectomy. Thus, there has been growing interest in meniscal repair. In addition, with increased understanding of the important roles of the meniscal root and advancement of diagnostic methods, efforts have been made to ensure preservation of the meniscal roots. In this review article, we will discuss operative techniques and clinical outcomes of arthroscopic repair of the meniscus and the meniscal root and postoperative rehabilitation and complications as well. PMID:24944971

  19. Cytogenetic studies of stainless steel welders using the tungsten inert gas and metal inert gas methods for welding.

    PubMed

    Jelmert, O; Hansteen, I L; Langård, S

    1995-03-01

    Cytogenetic damage was studied in lymphocytes from 23 welders using the Tungsten Inert Gas (TIG), and 21 welders using the Metal Inert Gas (MIG) and/or Metal Active Gas (MAG) methods on stainless steel (SS). A matched reference group I, and a larger reference group II of 94 subjects studied during the same time period, was established for comparison. Whole blood conventional cultures (CC), cultures in which DNA synthesis and repair were inhibited (IC), and the sister chromatid exchange (SCE) assay were applied in the study. For the CC a statistically significant decrease in chromosome breaks and cells with aberrations was found for both TIG/SS and MIG/MAG/SS welders when compared with reference group II. A non-significant decrease was found for the corresponding parameters for the two groups of welders when compared with their matched referents. A statistically significant negative association was found between measurements of total chromium (Cr) in inhaled air and SCE, and a weaker negative correlation with hexavalent Cr (Cr(VI)) in air. In conclusion, no cytogenetic damage was found in welders exposed to the TIG/SS and MIG/MAG/SS welding fumes with low content of Cr and Ni. On the contrary, a decline in the prevalence of chromosomal aberrations was indicated in the TIG/SS and MIG/MAG/SS welders, possibly related to the suggested enhancement of DNA repair capacity at slightly elevated exposures. PMID:7885396

  20. Molecular cytogenetic characterization of cancer cell alterations.

    PubMed

    Popescu, N C; Zimonjic, D B

    1997-01-01

    Chromosomal abnormalities are the hallmark of cancer cells. Recurring and highly consistent structural and numerical alterations have been identified in a large number of leukemias, lymphomas, and solid tumors. The identification of recurrent genetic alterations and the isolation of molecular markers have clinical applications in the diagnosis and prognosis of neoplasia and in the detection of minimal residual disease that are essential for designing the most effective therapeutic approach. Polymerase chain reaction (PCR) and fluorescence in situ hybridization (FISH) are powerful techniques for detection of genomic alterations. The battery of FISH methods and DNA probes that are available can resolve virtually any chromosomal alterations regardless of their complexity. Combined chromosome banding, multifluor or spectral karyotype, and comparative genomic hybridization (CGH) allow identification of structural and numerical alterations on a global basis, mapping of the DNA copy number on the entire tumor genome, complete derivation of complex rearrangements, and localization of the breakpoints of translocations and deletions. Regions of recurrent alterations can be microdisected, amplified, microclone libraries constructed and probes localized on extended chromosomes or chromatin fibers for construction of high resolution physical maps that are critical for positional cloning and gene identification. In this review we attempted to cover the current trends in cancer molecular cytogenetics, and to outline the importance of molecular chromosome analysis in the understanding of oncogenesis and its clinical applications. PMID:9062575

  1. Increased cytogenetic damage in outdoor painters.

    PubMed

    Pinto, D; Ceballos, J M; García, G; Guzmán, P; Del Razo, L M; Vera, E; Gómez, H; García, A; Gonsebatt, M E

    2000-05-01

    Painters are exposed to an extensive variety of hazardous substances such as organic solvents, lead-containing pigments and residual plastic monomers. In this particular case, workers used commercially available exterior paints and occasionally gasoline or thinner as solvents. The application or removal of paints was performed without protection (masks or gloves). To determine occupational exposure risk, a monitoring study was designed. Group selection was made after a questionnaire administration, which included questions about lifestyle and medical history to exclude exposure to other potential sources of genotoxics. Smoking and drinking habits were also considered. Blood and buccal cell samples were obtained from 25 public building male painters and from a similar number of age- and gender-matched controls. Lead levels were measured in paint samples and in individuals' blood. Organic solvents and/or its metabolites were also determined in blood. Chromosomal aberrations (CA) and sister chromatid exchanges (SCE) were determined in peripheral blood lymphocyte cultures. Also, the frequency of micronuclei (MN) in buccal cells was investigated. Painters had higher lead levels in blood (p<0.05); CA and SCE in lymphocytes and MN in epithelial cells were also elevated (p<0.05). Cytogenetic damage was significantly associated with occupational exposure time but not with the levels of lead found in blood. PMID:10838197

  2. Interphase Molecular Cytogenetic Detection Rates of Chronic Lymphocytic Leukemia-Specific Aberrations Are Higher in Cultivated Cells Than in Blood or Bone Marrow Smears.

    PubMed

    Alhourani, Eyad; Aroutiounian, Rouben; Harutyunyan, Tigran; Glaser, Anita; Schlie, Cordula; Pohle, Beate; Liehr, Thomas

    2016-08-01

    Banding cytogenetics is still the gold standard in many fields of leukemia diagnostics. However, in chronic lymphocytic leukemia (CLL), GTG-banding results are hampered by a low mitotic rate of the corresponding malignant lymphatic cells. Thus, interphase fluorescence in situ hybridization (iFISH) for the detection of specific cytogenetic aberrations is done nowadays as a supplement to or even instead of banding cytogenetics in many diagnostic laboratories. These iFISH studies can be performed on native blood or bone marrow smears or in nuclei after cultivation and stimulation by a suitable mitogen. As there are only few comparative studies with partially conflicting results for the detection rates of aberrations in cultivated and native cells, this question was studied in 38 CLL cases with known aberrations in 11q22.2, 11q22.3, 12, 13q14.3, 14q32.33, 17p13.1, or 18q21.32. The obtained results implicate that iFISH directly applied on smears is in general less efficient for the detection of CLL-specific genetic abnormalities than for cultivated cells. This also shows that applied cell culture conditions are well suited for malignant CLL cells. Thus, to detect malignant aberrant cells in CLL, cell cultivation and cytogenetic workup should be performed and the obtained material should be subjected to banding cytogenetics and iFISH. PMID:27315825

  3. Nucleotide excision repair in humans.

    PubMed

    Spivak, Graciela

    2015-12-01

    The demonstration of DNA damage excision and repair replication by Setlow, Howard-Flanders, Hanawalt and their colleagues in the early 1960s, constituted the discovery of the ubiquitous pathway of nucleotide excision repair (NER). The serial steps in NER are similar in organisms from unicellular bacteria to complex mammals and plants, and involve recognition of lesions, adducts or structures that disrupt the DNA double helix, removal of a short oligonucleotide containing the offending lesion, synthesis of a repair patch copying the opposite undamaged strand, and ligation, to restore the DNA to its original form. The transcription-coupled repair (TCR) subpathway of NER, discovered nearly two decades later, is dedicated to the removal of lesions from the template DNA strands of actively transcribed genes. In this review I will outline the essential factors and complexes involved in NER in humans, and will comment on additional factors and metabolic processes that affect the efficiency of this important process. PMID:26388429

  4. Prognostic Impact of Cytogenetic Abnormalities in Multiple Myeloma

    PubMed Central

    Jian, Yuan; Chen, Xiaolei; Zhou, Huixing; Zhu, Wanqiu; Liu, Nian; Geng, Chuanying; Chen, Wenming

    2016-01-01

    Abstract The identification of specific cytogenetic abnormalities by interphase fluorescence in situ hybridization (i-FISH) has become a routine procedure for prognostic stratification of multiple myeloma (MM) patients. In this study, the prognostic significance of cytogenetic abnormalities detected by interphase fluorescence in situ hybridization (iFISH) in 229 newly diagnosed multiple myeloma patients was retrospectively analyzed. Results showed that del (17p), t(4;14), and 1q21 gain were adverse predictors of progression-free survival (PFS). Patients who carried these cytogenetic abnormalities were more likely to have more adverse biological parameters and lower response rate. Multivariate analysis showed that del (17p), t(4;14), and 1q21 gain were statistically independent predictors of PFS, whereas del (17p) was also adverse predictor of overall survival. Multiple coexisting cytogenetic abnormalities also had a negative correlation with PFS. Bortezomib-based therapy could improve the rate and depth of response in patients with t(4;14) translocation and 1q21 gain. Autologous stem cell transplantation could improve, but not overcome the adverse prognostic effect of high-risk cytogenetic abnormalities. These results demonstrate that MM patients with iFISH abnormalities, especially del (17p), are more likely to have a poor prognosis. PMID:27175647

  5. Significance of cytogenetic abnormalities in patients with polycythemia vera.

    PubMed

    Sever, Matjaz; Quintás-Cardama, Alfonso; Pierce, Sherry; Zhou, Lingsha; Kantarjian, Hagop; Verstovsek, Srdan

    2013-12-01

    We analyzed 133 patients with polycythemia vera (PV) who were followed at our institution (median 7.5 years) and had adequate cytogenetics information. The 5-, 10- and 15-year survival rates were 93%, 79% and 64%, respectively, with a median projected overall survival of 24 years. Nineteen patients (14%) had abnormal cytogenetics at any time during the disease course (no survival difference). Sixteen patients (12%) underwent disease transformation during follow-up, after a median of 8.5 years, to myelofibrosis (n = 11), acute myeloid leukemia (n = 4) or myelodysplastic syndrome (n = 1); eight had cytogenetic abnormalities. Among 133 patients, 39 were newly diagnosed: 33 with normal and six with abnormal cytogenetics (no survival difference); nine underwent disease transformation (six with normal and three with abnormal cytogenetics at diagnosis). In keeping with other smaller series, the presence of chromosomal abnormalities may have had a role in disease transformation in patients with PV; survival was not affected likely due to short follow-up. PMID:23488603

  6. Aortic aneurysm repair - endovascular

    MedlinePlus

    ... Endovascular aneurysm repair - aorta; AAA repair - endovascular; Repair - aortic aneurysm - endovascular ... leaking or bleeding. You may have an abdominal aortic aneurysm that is not causing any symptoms or problems. ...

  7. Eye muscle repair - discharge

    MedlinePlus

    ... Lazy eye repair - discharge; Strabismus repair - discharge; Extraocular muscle surgery - discharge ... You or your child had eye muscle repair surgery to correct eye muscle ... term for crossed eyes is strabismus. Children most often ...

  8. Brain aneurysm repair

    MedlinePlus

    ... aneurysm repair; Dissecting aneurysm repair; Endovascular aneurysm repair - brain; Subarachnoid hemorrhage - aneurysm ... Your scalp, skull, and the coverings of the brain are opened. A metal clip is placed at ...

  9. Aortic aneurysm repair - endovascular

    MedlinePlus

    EVAR; Endovascular aneurysm repair - aorta; AAA repair - endovascular; Repair - aortic aneurysm - endovascular ... leaking or bleeding. You may have an abdominal aortic aneurysm that is not causing any symptoms or problems. ...

  10. Cytogenetic abnormalities in Tunisian women with premature ovarian failure.

    PubMed

    Ayed, Wiem; Amouri, Ahlem; Hammami, Wajih; Kilani, Olfa; Turki, Zinet; Harzallah, Fatma; Bouayed-Abdelmoula, Nouha; Chemkhi, Imen; Zhioua, Fethi; Slama, Claude Ben

    2014-12-01

    To identify the distribution of chromosome abnormalities among Tunisian women with premature ovarian failure (POF) referred to the department of Cytogenetic at the Pasteur Institute of Tunis (Tunisia), standard cytogenetic analysis was carried out in a total of 100 women younger than 40 affected with premature ovarian failure. We identified 18 chromosomal abnormalities, including seven X-numerical anomalies in mosaic and non-mosaic state (45,X; 47,XXX), four sex reversal, three X-structural abnormalities (terminal deletion and isochromosomes), one autosomal translocation and one supernumerary marker. The overall prevalence of chromosomal abnormalities was 18% in our cohort. X chromosome aneuploidy was the most frequent aberration. This finding confirms the essential role of X chromosome in ovarian function and underlies the importance of cytogenetic investigations in the routine management of POF. PMID:25433561

  11. Cytogenetic profile of Indian patients with de novo myelodysplastic syndromes

    PubMed Central

    Chaubey, Rekha; Sazawal, Sudha; Dada, Rima; Mahapatra, Manoranjan; Saxena, Renu

    2011-01-01

    Background & objectives: Myelodysplastic syndrome (MDS) is a clonal haematopoietic stem cell disorder characterized by ineffective haematopoiesis and leukaemia progression. Cytogenetic analysis has proven to be a mandatory part of the diagnosis of MDS as well as a major indicator for predicting clinical course and outcome. Studies on cytogenetics of MDS are reported mostly from the West and only a few are available from Asian countries. We report herein cytogenetic studies on 40 Indian patients with primary MDS to find out the occurrence and type of chromosome abnormalities and recurring defects. Methods: Cytogenetic analysis was done using GTG banding and karyotyped according to the International System for Human Cytogenetic Nomenclature (ISCN). Results: Of the 40 patients, 19 patients (47.5%) showed clonal karyotypic abnormalities with distribution as follows: 3 of 15 (20%) of refractory anaemia (RA), 4 of 7 (57%) of refractory anaemia with excess blasts-1 (RAEB-1), 4 of 6 (67%) of refractory anaemia with excess blasts 2 (RAEB-2), 2 of 3 (67%) of refractory anaemia with ring sideroblasts (RARS), 2 of 4 (50%) of refractory cytopenia with multilineage dysplasia (RCMD), none (0%) RCMD-ringed sideroblasts (RCMD-RS) and 4 patients with 5q syndrome. The frequent abnormalities observed in our study were -7, 5q-and trisomy 8. Interpretation & conclusions: Two rare chromosomal abnormalities (6q-, 3q-) were found with unknown prognostic significance. Hence, cytogenetic analysis may be incorporated in the routine diagnosis of MDS since there are racial differences in clinical pictures and the molecular events. PMID:22089606

  12. INTERNAL REPAIR OF PIPELINES

    SciTech Connect

    Robin Gordon; Bill Bruce; Nancy Porter; Mike Sullivan; Chris Neary

    2003-05-01

    The two broad categories of deposited weld metal repair and fiber-reinforced composite repair technologies were reviewed for potential application for internal repair of gas transmission pipelines. Both are used to some extent for other applications and could be further developed for internal, local, structural repair of gas transmission pipelines. Preliminary test programs were developed for both deposited weld metal repairs and for fiber-reinforced composite repair. To date, all of the experimental work pertaining to the evaluation of potential repair methods has focused on fiber-reinforced composite repairs. Hydrostatic testing was also conducted on four pipeline sections with simulated corrosion damage: two with composite liners and two without.

  13. Cytogenetic damage and occupational exposure. I. Exposure to stone dust.

    PubMed

    Sobti, R C; Bhardwaj, D K

    1991-10-01

    Cytogenetic investigations were carried out on 50 workers exposed to stone dust in a stone crusher industry and on 25 control subjects never exposed to such dust. The frequency of chromosomal aberrations and sister chromatid exchanges in exposed individuals was significantly higher than that in controls (P less than 0.01). The cytogenetic indices demonstrated a clear dependence on the working environment. The effect of smoking and/or alcoholic habits coupled with exposure to stone dust has also been investigated. The results indicate that the mutagenic risk in the working environment is probably associated with silica dust in the area. PMID:1655400

  14. Cytogenetic findings in persons living near the Love Canal

    SciTech Connect

    Heath, C.W. Jr.; Nadel, M.R.; Zack, M.M. Jr.; Chen, A.T.L.; Bender, M.A.; Preston, R.J.

    1984-03-16

    Cytogenetic analyses were performed on peripheral blood from 46 present or past residents of the areas surrounding Love Canal, a former dump site for chemical wastes in Niagara Falls, NY. Participants included 17 persons in whom cytogenetic analyses had been performed in 1980 and 29 persons who had been living in 1978 in seven homes that directly adjoined the canal and in which environmental tests showed elevated levels of chemicals spreading from the canal. Frequencies of chromosomal aberrations and of sister chromatid exchange (SCE) did not differ significantly from control levels. For all participants, cigarette smoking was associated with an increase in sister chromatid exchange frequency.

  15. Cytogenetic findings in persons living near the Love Canal.

    PubMed

    Heath, C W; Nadel, M R; Zack, M M; Chen, A T; Bender, M A; Preston, R J

    1984-03-16

    Cytogenetic analyses were performed on peripheral blood from 46 present or past residents of the area surrounding Love Canal, a former dump site for chemical wastes in Niagara Falls, NY. Participants included 17 persons in whom cytogenetic analyses had been performed in 1980 and 29 persons who had been living in 1978 in seven homes that directly adjoined the canal and in which environmental tests showed elevated levels of chemicals spreading from the canal. Frequencies of chromosomal aberrations and of sister chromatid exchange (SCE) did not differ significantly from control levels. For all participants, cigarette smoking was associated with an increase in sister chromatid exchange frequency. PMID:6700040

  16. Lack of Bystander Effects From High LET Radiation For Early Cytogenetic Endpoints.

    SciTech Connect

    Groesser, Torsten; Cooper, Brian; Rydberg, Bjorn

    2008-05-07

    The aim of this work was to study radiation-induced bystander effects for early cytogenetic end points in various cell lines using the medium transfer technique after exposure to high- and low-LET radiation. Cells were exposed to 20 MeV/ nucleon nitrogen ions, 968 MeV/nucleon iron ions, or 575 MeV/nucleon iron ions followed by transfer of the conditioned medium from the irradiated cells to unirradiated test cells. The effects studied included DNA double-strand break induction, {gamma}-H2AX focus formation, induction of chromatid breaks in prematurely condensed chromosomes, and micronucleus formation using DNA repair-proficient and -deficient hamster and human cell lines (xrs6, V79, SW48, MO59K and MO59J). Cell survival was also measured in SW48 bystander cells using X rays. Although it was occasionally possible to detect an increase in chromatid break levels using nitrogen ions and to see a higher number of {gamma}-H2AX foci using nitrogen and iron ions in xrs6 bystander cells in single experiments, the results were not reproducible. After we pooled all the data, we could not verify a significant bystander effect for any of these end points. Also, we did not detect a significant bystander effect for DSB induction or micronucleus formation in these cell lines or for clonogenic survival in SW48 cells. The data suggest that DNA damage and cytogenetic changes are not induced in bystander cells. In contrast, data in the literature show pronounced bystander effects in a variety of cell lines, including clonogenic survival in SW48 cells and induction of chromatid breaks and micronuclei in hamster cells. To reconcile these conflicting data, it is possible that the epigenetic status of the specific cell line or the precise culture conditions and medium supplements, such as serum, may be critical for inducing bystander effects.

  17. Cytogenetic effects from exposure to mixed pesticides and the influence from genetic susceptibility.

    PubMed Central

    Au, W W; Sierra-Torres, C H; Cajas-Salazar, N; Shipp, B K; Legator, M S

    1999-01-01

    Exposure to pesticides remains a major environmental health problem. Health risk from such exposure needs to be more precisely understood. We conducted three different cytogenetic assays to elucidate the biological effects of exposure to mixed pesticides in 20 Costa Rica farmers (all nonsmokers) compared with 20 matched controls. The farmers were also exposed to dibromochloropropane during the early employment years, and most of them experienced sterility/fertility problems. Our data show that the farmers had consistently higher frequencies of chromosome aberrations, as determined by the standard chromosome aberration assay, and significantly abnormal DNA repair responses (p < 0.05), as determined by the challenge assay, but no statistically significant differences in the tandem-probe fluorescence in situ hybridization (FISH) assay (p > 0.05). Genotype analysis indicates that farmers with certain "unfavorable" versions of polymorphic metabolizing genes (cytochrome P4502E1, the glutathione S-transferases mu and theta, and the paraoxonase genes) had significantly more biological effects, as determined by all three cytogenetic assays, than both the farmers with the "favorable" alleles and the matched controls. A unique observation is that, in individuals who had inherited any of the mentioned "unfavorable" alleles, farmers were consistently underrepresented. In conclusion, the Costa Rican farmers were exposed to genotoxic agents, most likely pesticides, which expressed the induction of biological and adverse health effects. The farmers who had inherited "unfavorable" metabolizing alleles were more susceptible to genotoxic effects than those with "favorable" alleles. Our genotype data suggest that the well-recognized "healthy worker effect" may be influenced by unrecognized occupational selection pressure against genetically susceptible individuals. Images Figure 1 PMID:10339452

  18. Repairing Posteromedial Meniscocapsular Separation: A Technique Using Inside-Out Meniscal Repair Needles

    PubMed Central

    Joshi, Anant; Usman, Sajeer; Sabnis, Bhushan; Kini, Abhishek

    2016-01-01

    Posteromedial meniscocapsular separation of the knee has received renewed interest, with many articles describing a high incidence in association with anterior cruciate ligament injury. Various techniques have been described to address these lesions using all-inside meniscal repair sutures or using rotator cuff repair instruments through the posteromedial portal. Most orthopaedic surgeons are accustomed to using the “inside-out” meniscal repair technique with a double-armed suture. This technique is cost-effective and, in our opinion, more efficient in repairing such tears. We present our technique of repairing peripheral meniscocapsular lesions using an inside-out meniscal repair system. We believe that this technique is easily reproducible, is less time-consuming, and ensures a good “bite” of the capsular tissue, producing a robust repair. PMID:27073773

  19. Molecular cytogenetic analysis of Xq critical regions in premature ovarian failure

    PubMed Central

    2013-01-01

    Background One of the frequent reasons for unsuccessful conception is premature ovarian failure/primary ovarian insufficiency (POF/POI) that is defined as the loss of functional follicles below the age of 40 years. Among the genetic causes the most common one involves the X chromosome, as in Turner syndrome, partial X deletion and X-autosome translocations. Here we report a case of a 27-year-old female patient referred to genetic counselling because of premature ovarian failure. The aim of this case study to perform molecular genetic and cytogenetic analyses in order to identify the exact genetic background of the pathogenic phenotype. Results For premature ovarian failure disease diagnostics we performed the Fragile mental retardation 1 gene analysis using Southern blot technique and Repeat Primed PCR in order to identify the relationship between the Fragile mental retardation 1 gene premutation status and the premature ovarion failure disease. At this early onset, the premature ovarian failure affected patient we detected one normal allele of Fragile mental retardation 1 gene and we couldn’t verify the methylated allele, therefore we performed the cytogenetic analyses using G-banding and fluorescent in situ hybridization methods and a high resolution molecular cytogenetic method, the array comparative genomic hybridization technique. For this patient applying the G-banding, we identified a large deletion on the X chromosome at the critical region (ChrX q21.31-q28) which is associated with the premature ovarian failure phenotype. In order to detect the exact breakpoints, we used a special cytogenetic array ISCA plus CGH array and we verified a 67.355 Mb size loss at the critical region which include total 795 genes. Conclusions We conclude for this case study that the karyotyping is definitely helpful in the evaluation of premature ovarian failure patients, to identify the non submicroscopic chromosomal rearrangement, and using the array CGH technique we can

  20. Book Repair Manual.

    ERIC Educational Resources Information Center

    Milevski, Robert J.

    1995-01-01

    This book repair manual developed for the Illinois Cooperative Conservation Program includes book structure and book problems, book repair procedures for 4 specific problems, a description of adhesive bindings, a glossary, an annotated list of 11 additional readings, book repair supplies and suppliers, and specifications for book repair kits. (LRW)

  1. Cytogenetic and molecular abnormalities in chronic myelomonocytic leukemia

    PubMed Central

    Patnaik, M M; Tefferi, A

    2016-01-01

    Chronic myelomonocytic leukemia (CMML) is a clonal stem cell disorder associated with peripheral blood monocytosis and an inherent tendency to transform to acute myeloid leukemia. CMML has overlapping features of myelodysplastic syndromes and myeloproliferative neoplasms. Clonal cytogenetic changes are seen in ~30%, whereas gene mutations are seen in >90% of patients. Common cytogenetic abnormalities include; trisomy 8, -Y, -7/del(7q), trisomy 21 and del(20q), with the Mayo–French risk stratification effectively risk stratifying patients based on cytogenetic abnormalities. Gene mutations frequently involve epigenetic regulators (TET2 ~60%), modulators of chromatin (ASXL1 ~40%), spliceosome components (SRSF2 ~50%), transcription factors (RUNX1 ~15%) and signal pathways (RAS ~30%, CBL ~15%). Of these, thus far, only nonsense and frameshift ASXL1 mutations have been shown to negatively impact overall survival. This has resulted in the development of contemporary, molecularly integrated (inclusive of ASXL1 mutations) CMML prognostic models, including Molecular Mayo Model and the Groupe Français des Myélodysplasies model. Better understanding of the prevalent genetic and epigenetic dysregulation has resulted in emerging targeted treatment options for some patients. The development of an integrated (cytogenetic and molecular) prognostic model along with CMML-specific response assessment criteria are much needed future goals. PMID:26849014

  2. Practical Instruction in Tissue Culture and Cytogenetics for Sandwich Students.

    ERIC Educational Resources Information Center

    Williams, D. C.; Bishun, N. P.

    1973-01-01

    Describes the training and practical techniques taught to students involved in a sandwich course at the Tissue Culture and Cytogenetics Unit of the Marie Curie Memorial Foundation, Surrey, England. Students spend a minimum of six months involved in the sandwich course before returning to university for a final academic year. (JR)

  3. 'NEANTHES ARENACEODENTATA', A CYTOGENETIC MODEL FOR MARINE GENETIC TOXICOLOGY

    EPA Science Inventory

    Genetic toxicants are present in polluted marine environments and may represent a long-term threat to populations of marine organisms. A cytogenetic model is useful to study the effects of these toxicants. The polychaeta, Neanthes arenaceodentata, was chosen as such a model becau...

  4. 42 CFR 493.1276 - Standard: Clinical cytogenetics.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Standard: Clinical cytogenetics. 493.1276 Section 493.1276 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) STANDARDS AND CERTIFICATION LABORATORY REQUIREMENTS Quality System for...

  5. Cytogenetic studies of three triazine herbicides. I. In vitro studies

    EPA Science Inventory

    Atrazine, simazine, and cyanazine are widely used pre-emergence and post-emergence triazine herbicides that have made their way into the potable water supply of many agricultural communities. Because of this and the prevalence of contradictory cytogenetic studies in the literatur...

  6. CYTOGENETIC INVESTIGATIONS OF NON-DORMANT ALFALFA GERMPLASM SOURCES

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The combined techniques of chromosome C-banding, image analysis, and cluster analysis were utilized to compare the four historically distinct non-dormant alfalfa germplasm sources of tetraploid alfalfa (Medicago sativa ssp. sativa). Cytogenetic analyses revealed polymorphisms for heterochromatic DN...

  7. [Cytogenetic activity of the butylcaptax defoliant transformation product].

    PubMed

    Vesmanova, O Ia; Semykina, E E; Koblov, R K; Ergashev

    1989-01-01

    Cytogenetical activity of the product of metabolitic butylcaptax transformations in cells of cotton plants G. barbadense has been studied. It is shown that butylcaptax, with a significant mutagenicity, looses its mutagenic activity, metabolizing in low mutagenic 2-oxyamylthiobenzthiazole. Low water solubility prevents its concentration to exceed 0.005% in tissue liquids and to exert a mutagenic action on cotton plants. PMID:2773061

  8. Constructing a Cytogenetic Map of the Maize Genome

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We are developing a pachytene cytogenetic FISH (Fluorescence in situ Hybridization) map of the maize (Zea mays L.) genome using maize marker-selected sorghum BACs (Bacterial Artificial Chromosome) as described by Koumbaris and Bass (2003, Plant J. 35:647). The two main projects are the production of...

  9. Cytogenetic and molecular findings in patients with Turner's syndrome stigmata.

    PubMed Central

    Kuznetzova, T; Baranov, A; Schwed, N; Ivaschenko, T; Malet, P; Giollant, M; Savitsky, G A; Baranov, V

    1995-01-01

    Cytogenetic and DNA analysis in 12 people with stigmata of Turner's syndrome was carried out. Cytogenetic analysis of these patients showed two subjects with 46,X, i(Xq) karyotypes, one with 45,X/46,X, i(Xq), one with 46,X,t(X;Y), and eight with 45,X/46,X,mar. Molecular analysis of DNA samples was performed in nine out of 12 patients with marker chromosomes. PCR analysis with oligoprimers specific for SRY, DYZ1, or DYZ3 loci identified Y chromosome material in five patients in the latter group. The X chromosome origin of the marker chromosome was proved by FISH technique with biotin labelled pericentromeric X chromosome specific probe in four other patients. These results show that patients with a number of Turner's syndrome stigmata usually do not have a typical XO karyotype but have some structural chromosomal aberrations involving the X or Y chromosomes. Combined application of cytogenetic, molecular cytogenetic (FISH), and PCR techniques significantly improves the precision of marker chromosome identification and thus might be of practical importance for the proper management and treatment of affected patients. Peculiarities of pathological manifestations of different karyotypes bearing structural abnormalities of the X or Y chromosomes in patients with Turner's syndrome stigmata, as well as feasible genetic mechanisms of sex determination and differentiation abnormalities in these subjects, are briefly discussed. Images PMID:8825925

  10. 42 CFR 493.1276 - Standard: Clinical cytogenetics.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 493.1276 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN... and procedures for ensuring accurate and reliable patient specimen identification during the process... of cells counted and analyzed, and use the International System for Human Cytogenetic...

  11. 42 CFR 493.1276 - Standard: Clinical cytogenetics.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 493.1276 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN... and procedures for ensuring accurate and reliable patient specimen identification during the process... of cells counted and analyzed, and use the International System for Human Cytogenetic...

  12. International Working Group on MDS cytogenetics: October 2007 meeting report.

    PubMed

    Slovak, Marilyn L; Dewald, Gordon W

    2008-09-01

    The inaugural meeting of the International Working Group on MDS cytogenetics convened 22-23 October 2007 in Chicago, IL. Under the sponsorship of the Myelodysplastic Syndromes Foundation, the group was organized to address the substantial need for worldwide standardized cytogenetic testing for MDS in clinical practice and research. Eighteen cytogeneticists from 10 countries attended the first working group meeting. Representatives from France and Austria were unable to attend the Chicago meeting. Marilyn L. Slovak, PhD (City of Hope, USA) served as Working Group Chair and Gordon Dewald, PhD (Mayo Clinic, USA), served as Working Group Advisor and Co-Chair. Other members in attendance included: Mette Andersen, Rigshospitalet, Denmark; Lynda Campbell, St. Vincent's Hospital Melbourne, Australia; Athena Cherry, Stanford University, USA; Kathy Chun, North York General Hospital, Canada; Mike Griffiths, West Midlands Regional Genetics Lab, UK; Detlef Haase, Georg-August-Universität, Germany; Claudia Haferlach, MLL Münchner Leukämielabor GmbH, Germany; Anne Hagemeijer, University of Leuven, Belgium; Barbara Hildebrandt, Institut für Humangenetik & Anthropologie Dupsilonsseldorf, Germany; Douglas Horsman, BC Cancer Agency, Canada; M. Anwar Iqbal, University of Rochester, USA; Suresh Jhanwar, Memorial Sloan-Kettering Cancer Center, USA; Bertil Johansson, University Hospital, Sweden; Michelle LeBeau, University of Chicago, USA; Kazuma Ohyashiki, Tokyo Medical University, Japan; Francesc Solé, Hospital del Mar, Spain. The focus of the working group was to establish the natural history and clinical significance of cytogenetic anomalies associated with the myelodysplastic syndromes (MDS), and to incorporate cytogenetic testing into the development of new treatments to cure MDS. Three specific goals were discussed in an effort to rapidly improve the care of patients with MDS. The first goal was how to educate physicians on the appropriate use of cost effective cytogenetic

  13. A somatic cell hybrid panel for pig regional gene mapping characterized by molecular cytogenetics.

    PubMed

    Yerle, M; Echard, G; Robic, A; Mairal, A; Dubut-Fontana, C; Riquet, J; Pinton, P; Milan, D; Lahbib-Mansais, Y; Gellin, J

    1996-01-01

    A panel of 27 pig x rodent somatic cell hybrids was produced and characterized cytogenetically. The first step of this study consisted of hybridizing a SINE probe to GTG-banded metaphases of each hybrid clone in order to count and identify the normal pig chromosomes and to detect rearranged ones. The second step consisted of using the DNA of each clone as a probe after pIRS-PCR (porcine interspersed repetitive sequence-polymerase chain reaction) amplification to highly enrich it in pig sequences. These probes, hybridized to normal pig metaphase chromosomes, enabled the identification of the complete porcine complement in the hybrid lines. Whole chromosomes and fragments were characterized quickly and precisely, and results were compared. In addition to this cytogenetic characterization, molecular verification was also carried out by using primers specific to six microsatellites and to one gene previously mapped to pig chromosomes. The results obtained allow us to conclude that we have produced a panel that is informative for all porcine chromosomes. This panel constitutes a highly efficient tool to establish not only assignments of genes and markers but also regional localizations on pig chromosomes. PMID:8697807

  14. Detection of cryptic Y chromosome mosaicism by coamplification PCR with archived cytogenetic slides of suspected Turner syndrome.

    PubMed

    Kim, J W; Cho, E H; Kim, Y M; Kim, J M; Han, J Y; Park, S Y

    2000-03-31

    Turner syndrome is one of the most common cytogenetic abnormalities. It is known that the Y chromosome or Y derived material is present in 6-9% of TS patient and it may develop a high risk of gonadoblastoma in 15-25%. So it is crucial to carry out cyto genetic analysis and Y-specific probe studies for all persons with gonadal dysgenesis to rule out mosaicism with Y-bearing cell line; eg 45,X/46,XY. In this study, 26 archival slides previously analyzed cytogenetically as 45,X, 45,X/46,X,i(X), 45,X/46,X,r(X), and 45,X/46,XX were examined. Coamplification PCR, having the advantage of providing rapid result and confirming PCR failure, was performed with the slide samples in the regions of dystrophin gene in Xp21and DYZ3 in the Y centromeric region. All of archived slides were positive for X-specific gene and one slide of 45,X was found to have the cryptic Y chromosome material. Our result suggests that the archived cytogenetic slides could be applied for the detection of Y chromosome rapidly and efficiently in TS patients. PMID:10762060

  15. Preferential DNA repair in expressed genes.

    PubMed Central

    Hanawalt, P C

    1987-01-01

    Potentially deleterious alterations to DNA occur nonrandomly within the mammalian genome. These alterations include the adducts produced by many chemical carcinogens, but not the UV-induced cyclobutane pyrimidine dimer, which may be an exception. Recent studies in our laboratory have shown that the excision repair of pyrimidine dimers and certain other lesions is nonrandom in the mammalian genome, exhibiting a distinct preference for actively transcribed DNA sequences. An important consequence of this fact is that mutagenesis and carcinogenesis may be determined in part by the activities of the relevant genes. Repair may also be processive, and a model is proposed in which excision repair is coupled to transcription at the nuclear matrix. Similar but freely diffusing repair complexes may account for the lower overall repair efficiencies in the silent domains of the genome. Risk assessment in relation to chemical carcinogenesis requires assays that determine effective levels of DNA damage for producing malignancy. The existence of nonrandom repair in the genome casts into doubt the reliability of overall indicators of DNA binding and lesion repair for such determinations. Furthermore, some apparent differences between the intragenomic repair heterogeneity in rodent cells and that in human cells mandate a reevaluation of rodent test systems for human risk assessment. Tissue-specific and cell-specific differences in the coordinate regulation of gene expression and DNA repair may account for corresponding differences in the carcinogenic response. Images FIGURE 1. FIGURE 1. PMID:3447906

  16. Cytogenetic insights into DNA damage and repair of lesions induced by a monomethylated trivalent arsenical

    EPA Science Inventory

    Arsenic is a human carcinogen, and only recently have animal models been developed that are useful in investigating its carcinogenic mode ofaction (MOA). However, how arsenic induces cancer is still an open question. In a previous paper, we proposed a model detailing how arsenic ...

  17. Rapid road repair vehicle

    DOEpatents

    Mara, Leo M.

    1998-01-01

    Disclosed is a rapid road repair vehicle capable of moving over a surface to be repaired at near normal posted traffic speeds to scan for and find an the high rate of speed, imperfections in the pavement surface, prepare the surface imperfection for repair by air pressure and vacuum cleaning, applying a correct amount of the correct patching material to effect the repair, smooth the resulting repaired surface, and catalog the location and quality of the repairs for maintenance records of the road surface. The rapid road repair vehicle can repair surface imperfections at lower cost, improved quality, at a higher rate of speed than was was heretofor possible, with significantly reduced exposure to safety and health hazards associated with this kind of road repair activities in the past.

  18. Rapid road repair vehicle

    DOEpatents

    Mara, L.M.

    1998-05-05

    Disclosed is a rapid road repair vehicle capable of moving over a surface to be repaired at near normal posted traffic speeds to scan for and find at the high rate of speed, imperfections in the pavement surface, prepare the surface imperfection for repair by air pressure and vacuum cleaning, applying a correct amount of the correct patching material to effect the repair, smooth the resulting repaired surface, and catalog the location and quality of the repairs for maintenance records of the road surface. The rapid road repair vehicle can repair surface imperfections at lower cost, improved quality, at a higher rate of speed than was not heretofor possible, with significantly reduced exposure to safety and health hazards associated with this kind of road repair activities in the past. 2 figs.

  19. Silencing of end-joining repair for efficient site-specific gene insertion after TALEN/CRISPR mutagenesis in Aedes aegypti

    PubMed Central

    Basu, Sanjay; Aryan, Azadeh; Overcash, Justin M.; Samuel, Glady Hazitha; Anderson, Michelle A. E.; Dahlem, Timothy J.; Myles, Kevin M.; Adelman, Zach N.

    2015-01-01

    Conventional control strategies for mosquito-borne pathogens such as malaria and dengue are now being complemented by the development of transgenic mosquito strains reprogrammed to generate beneficial phenotypes such as conditional sterility or pathogen resistance. The widespread success of site-specific nucleases such as transcription activator-like effector nucleases (TALENs) and clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 in model organisms also suggests that reprogrammable gene drive systems based on these nucleases may be capable of spreading such beneficial phenotypes in wild mosquito populations. Using the mosquito Aedes aegypti, we determined that mutations in the FokI domain used in TALENs to generate obligate heterodimeric complexes substantially and significantly reduce gene editing rates. We found that CRISPR/Cas9-based editing in the mosquito Ae. aegypti is also highly variable, with the majority of guide RNAs unable to generate detectable editing. By first evaluating candidate guide RNAs using a transient embryo assay, we were able to rapidly identify highly effective guide RNAs; focusing germ line-based experiments only on this cohort resulted in consistently high editing rates of 24–90%. Microinjection of double-stranded RNAs targeting ku70 or lig4, both essential components of the end-joining response, increased recombination-based repair in early embryos as determined by plasmid-based reporters. RNAi-based suppression of Ku70 concurrent with embryonic microinjection of site-specific nucleases yielded consistent gene insertion frequencies of 2–3%, similar to traditional transposon- or ΦC31-based integration methods but without the requirement for an initial docking step. These studies should greatly accelerate investigations into mosquito biology, streamline development of transgenic strains for field releases, and simplify the evaluation of novel Cas9-based gene drive systems. PMID:25775608

  20. Silencing of end-joining repair for efficient site-specific gene insertion after TALEN/CRISPR mutagenesis in Aedes aegypti.

    PubMed

    Basu, Sanjay; Aryan, Azadeh; Overcash, Justin M; Samuel, Glady Hazitha; Anderson, Michelle A E; Dahlem, Timothy J; Myles, Kevin M; Adelman, Zach N

    2015-03-31

    Conventional control strategies for mosquito-borne pathogens such as malaria and dengue are now being complemented by the development of transgenic mosquito strains reprogrammed to generate beneficial phenotypes such as conditional sterility or pathogen resistance. The widespread success of site-specific nucleases such as transcription activator-like effector nucleases (TALENs) and clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 in model organisms also suggests that reprogrammable gene drive systems based on these nucleases may be capable of spreading such beneficial phenotypes in wild mosquito populations. Using the mosquito Aedes aegypti, we determined that mutations in the FokI domain used in TALENs to generate obligate heterodimeric complexes substantially and significantly reduce gene editing rates. We found that CRISPR/Cas9-based editing in the mosquito Ae. aegypti is also highly variable, with the majority of guide RNAs unable to generate detectable editing. By first evaluating candidate guide RNAs using a transient embryo assay, we were able to rapidly identify highly effective guide RNAs; focusing germ line-based experiments only on this cohort resulted in consistently high editing rates of 24-90%. Microinjection of double-stranded RNAs targeting ku70 or lig4, both essential components of the end-joining response, increased recombination-based repair in early embryos as determined by plasmid-based reporters. RNAi-based suppression of Ku70 concurrent with embryonic microinjection of site-specific nucleases yielded consistent gene insertion frequencies of 2-3%, similar to traditional transposon- or ΦC31-based integration methods but without the requirement for an initial docking step. These studies should greatly accelerate investigations into mosquito biology, streamline development of transgenic strains for field releases, and simplify the evaluation of novel Cas9-based gene drive systems. PMID:25775608

  1. DNA Mismatch Repair

    PubMed Central

    MARINUS, M. G.

    2014-01-01

    DNA mismatch repair functions to correct replication errors in newly synthesized DNA and to prevent recombination between related, but not identical (homeologous), DNA sequences. The mechanism of mismatch repair is best understood in Escherichia coli and is the main focus of this review. The early genetic studies of mismatch repair are described as a basis for the subsequent biochemical characterization of the system. The effects of mismatch repair on homologous and homeologous recombination are described. The relationship of mismatch repair to cell toxicity induced by various drugs is included. The VSP (Very Short Patch) repair system is described in detail. PMID:26442827

  2. Protein oxidation, UVA and human DNA repair.

    PubMed

    Karran, Peter; Brem, Reto

    2016-08-01

    Solar UVB is carcinogenic. Nucleotide excision repair (NER) counteracts the carcinogenicity of UVB by excising potentially mutagenic UVB-induced DNA lesions. Despite this capacity for DNA repair, non-melanoma skin cancers and apparently normal sun-exposed skin contain huge numbers of mutations that are mostly attributable to unrepaired UVB-induced DNA lesions. UVA is about 20-times more abundant than UVB in incident sunlight. It does cause some DNA damage but this does not fully account for its biological impact. The effects of solar UVA are mediated by its interactions with cellular photosensitizers that generate reactive oxygen species (ROS) and induce oxidative stress. The proteome is a significant target for damage by UVA-induced ROS. In cultured human cells, UVA-induced oxidation of DNA repair proteins inhibits DNA repair. This article addresses the possible role of oxidative stress and protein oxidation in determining DNA repair efficiency - with particular reference to NER and skin cancer risk. PMID:27324272

  3. Cytogenetic and molecular analysis in trisomy 12p

    SciTech Connect

    Allen, T.L.; Brothman, A.R.; Carey, J.C.

    1996-05-03

    We studied a male patient with de novo pure trisomy 12p syndrome by molecular analysis and fluorescence in situ hybridization (FISH) with markers from chromosome 12. G-banding studies demonstrated a 46,XY, 22p+ karyotype and the banding pattern and clinical findings suggested that the extra chromosomal material was derived from 12p. Trisomy 12p was confirmed by dosage analysis with chromosome 12p markers and FISH analysis with a whole chromosome 12 paint. The de novo rearranged chromosome was of paternal origin. A comparison of the clinical and cytogenetic findings in this patient was made with previously described cases of trisomy 12p. We propose a classification system for 12p trisomy in order to better characterize the correlative relationships between specific cytogenetic constitution and phenotype. 32 refs., 5 figs., 2 tabs.

  4. Comparative cytogenetics of Auchenorrhyncha (Hemiptera, Homoptera): a review

    PubMed Central

    Kuznetsova, Valentina; Aguin-Pombo, Dora

    2015-01-01

    Abstract A comprehensive review of cytogenetic features is provided for the large hemipteran suborder Auchenorrhyncha, which currently contains approximately 42,000 valid species. This review is based on the analysis of 819 species, 483 genera, and 31 families representing all presently recognized Auchenorrhyncha superfamilies, e.i. Cicadoidea (cicadas), Cercopoidea (spittle bugs), Membracoidea (leafhoppers and treehoppers), Myerslopioidea (ground-dwelling leafhoppers), and Fulgoroidea (planthoppers). History and present status of chromosome studies are described, as well as the structure of chromosomes, chromosome counts, trends and mechanisms of evolution of karyotypes and sex determining systems, their variation at different taxonomic levels and most characteristic (modal) states, occurrence of parthenogenesis, polyploidy, B-chromosomes and chromosome rearrangements, and methods used for cytogenetic analysis of Auchenorrhyncha. PMID:26807037

  5. Eye muscle repair - discharge

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000111.htm Eye muscle repair - discharge To use the sharing features on ... enable JavaScript. You or your child had eye muscle repair surgery to correct eye muscle problems that ...

  6. Umbilical hernia repair

    MedlinePlus

    Umbilical hernia repair is surgery to repair an umbilical hernia . An umbilical hernia is a sac (pouch) formed from the ... the hole or weak spot caused by the umbilical hernia. Your surgeon may also lay a piece ...

  7. Femoral hernia repair

    MedlinePlus

    ... pushed back in. The weakened area is sewn closed or strengthened. This repair can be done with ... end of the repair, the cuts are stitched closed. In laparascopic surgery: The surgeon makes three to ...

  8. Laparoscopic Inguinal Hernia Repair

    MedlinePlus

    ... Some hernia repairs are performed using a small telescope known as a laparoscope. If your surgeon has ... in the abdominal wall (muscle) using small incisions, telescopes and a patch (mesh). Laparoscopic repair offers a ...

  9. Cytogenetic genotoxic investigation in peripheral blood lymphocytes of subjects with dental composite restorative filling materials.

    PubMed

    Pettini, F; Savino, M; Corsalini, M; Cantore, S; Ballini, A

    2015-01-01

    Dental composite resins are biomaterials commonly used to aesthetically restore the structure and function of teeth impaired by caries, erosion, or fracture. Residual monomers released from resin restorations as a result of incomplete polymerization processes interact with living oral tissues. The objective of this study was to evaluate the genotoxicity of a common dental composite material (Enamel Plus-HFO), in subjects with average 13 filled teeth with the same material, compared to a control group (subjects having neither amalgam nor composite resin fillings). Genotoxicity assessment of composite materials was carried out in vitro in human peripheral blood leukocytes using sister-chromatid exchange (SCE) and chromosomal aberrations (CA) cytogenetic tests. The results of correlation and multiple regression analyses confirmed the absence of a relationship between SCE/cell, high frequency of SCE(HFC) or CA frequencies and exposure to dental composite materials. These results indicate that composite resins used for dental restorations differ extensively in vivo in their cytotoxic and genotoxic potential and in their ability to affect chromosomal integrity, cell-cycle progression, DNA replication and repair. PMID:25864763

  10. Cytogenetics of monosomes in Zea mays. Final report

    SciTech Connect

    Weber, D.F.

    1984-11-01

    The cytogenetics of monosomics in maize generated using the r-X1 system was studied. The goal was to isolate as many as possible of the ten possible primary monosomic types and to characterize them by studying: (1) the cytology of meiosis; (2) the cytological behavior of monosomic chromosomes in meiosis; (3) the effect of monosomic on recombination in heterozygous bivalents; and (4) the frequency and types of spontaneous chromosomal aberrations arising in monosomics. 113 references, 1 figure, 5 tables. (ACR)

  11. Aortic aneurysm repair - endovascular- discharge

    MedlinePlus

    ... page: //medlineplus.gov/ency/patientinstructions/000236.htm Aortic aneurysm repair - endovascular - discharge To use the sharing features ... enable JavaScript. AAA repair - endovascular - discharge; Repair - aortic aneurysm - endovascular - discharge; EVAR - discharge; Endovascular aneurysm repair - discharge ...

  12. Environmental genotoxicity evaluation using cytogenetic end points in wild rodents.

    PubMed Central

    de Souza Bueno, A M; de Bragança Pereira, C A; Rabello-Gay, M N

    2000-01-01

    We analyzed cytogenetic end points in three populations of two species of wild rodents--Akodon montensis and Oryzomys nigripes--living in an industrial, an agricultural, and a preservation area at the Itajaí Valley, state of Santa Catarina, Brazil. Our purpose was to evaluate the performance of the following end points in the establishment of a genotoxic profile of each area: the polychromatic/normochromatic cell ratio; the mitotic index; the frequency of micronucleated cells both in the bone marrow and peripheral blood; and the frequency of cells with chromosome aberrations in the bone marrow. Preparations were obtained using conventional cytogenetic techniques. The results showed a) the role of the end points used as biomarkers in the early detection of genotoxic agents and in the identification of species and populations at higher risk; b) the difference in sensitivity of the species selected as bioindicators in relation to the cytogenetic end points analyzed; c) the need to use at least two sympatric species to detect the presence of genotoxins in each locality; and d) the need to use several end points when trying to establish a genotoxic profile of an area. PMID:11133397

  13. Human DNA repair and recombination genes

    SciTech Connect

    Thompson, L.H.; Weber, C.A.; Jones, N.J.

    1988-09-01

    Several genes involved in mammalian DNA repair pathways were identified by complementation analysis and chromosomal mapping based on hybrid cells. Eight complementation groups of rodent mutants defective in the repair of uv radiation damage are now identified. At least seven of these genes are probably essential for repair and at least six of them control the incision step. The many genes required for repair of DNA cross-linking damage show overlap with those involved in the repair of uv damage, but some of these genes appear to be unique for cross-link repair. Two genes residing on human chromosome 19 were cloned from genomic transformants using a cosmid vector, and near full-length cDNA clones of each gene were isolated and sequenced. Gene ERCC2 efficiently corrects the defect in CHO UV5, a nucleotide excision repair mutant. Gene XRCC1 normalizes repair of strand breaks and the excessive sister chromatid exchange in CHO mutant EM9. ERCC2 shows a remarkable /approximately/52% overall homology at both the amino acid and nucleotide levels with the yeast RAD3 gene. Evidence based on mutation induction frequencies suggests that ERCC2, like RAD3, might also be an essential gene for viability. 100 refs., 4 tabs.

  14. γδ T Cells Are Necessary for Platelet and Neutrophil Accumulation in Limbal Vessels and Efficient Epithelial Repair after Corneal Abrasion

    PubMed Central

    Li, Zhijie; Burns, Alan R.; Rumbaut, Rolando E.; Smith, C. Wayne

    2007-01-01

    Corneal epithelial abrasion in C57BL/6 mice induces an inflammatory response with peak accumulation of neutrophils in the corneal stroma within 12 hours. Platelets localize in the limbal vessels throughout the same time course as neutrophils and contribute to wound healing because antibody-dependent depletion of platelets retards epithelial division and wound closure. In the present study, T cells in the limbal epithelium were found to predominantly express the γδ T-cell receptor (TCR). Corneal abrasion in wild-type, CD11a−/−, and P-sel−/− mice increased the numbers of γδ T cells in the limbal and peripheral corneal epithelium and in the corneal stroma adjacent to the limbal blood vessels. Intercellular adhesion molecule (ICAM)-1−/− mice exhibited a reduction in γδ T-cell accumulation. TCRδ−/− mice exhibited reduced inflammation and delayed epithelial wound healing as evidenced by delayed wound closure, reduced epithelial cell division, reduced neutrophil infiltration, and reduced epithelial cell density at 96 hours after wounding. TCRδ−/− mice also exhibited >60% reduction in platelet localization in the limbus despite similar platelet counts and platelet function assessed with an in vivo thrombosis model. These results are consistent with the conclusion that γδ T cells are necessary for efficient inflammation, platelet localization in the limbus, and epithelial wound healing after corneal abrasion. PMID:17675580

  15. DNA Repair Defects and Chromosomal Aberrations

    NASA Technical Reports Server (NTRS)

    Hada, Megumi; George, K. A.; Huff, J. L.; Pluth, J. M.; Cucinotta, F. A.

    2009-01-01

    the DNA repair-defective cell lines were smaller than those of normal cells, with the DNA-PK-deficient cells having RBEs near unity. To further investigate the sensitivity differences that were observed in ATM and NBS deficient cells, chromosomal aberrations were analyzed in normal lung fibroblast cells treated with KU-55933 (a specific ATM kinase inhibitor) or Mirin (an Mre11- Rad50-Nbs1 complex inhibitor involved in activation of ATM). We also performed siRNA knockdown of these proteins. Preliminary data indicate that chromosome exchanges increase in cells treated with the specific ATM inhibitor. Possible cytogenetic signatures of acute and low dose-rate gamma irradiation in ATM or nibrin deficient and suppressed cells will be discussed.

  16. Cytogenetic analysis of human somatic cell haploidization.

    PubMed

    Galat, V; Ozen, S; Rechitsky, S; Kuliev, A; Verlinsky, Y

    2005-02-01

    Despite recent interest in the derivation of female and male gametes through somatic cell nuclear transfer, there is still insufficient data on chromosomal analysis of these gametes resulting from haploidization, especially involving a human nuclear donor and recipient oocytes. The objective of this study was to investigate the fidelity of chromosomal separation during haploidization of human cumulus cells by in-vitro matured human enucleated MII oocytes. A total of 129 oocytes were tested 4-7, 8-14, or 15-21 h after nuclear transfer (NT) followed by electro-stimulation, resulting in 71.3% activation efficiency on average. Haploidization was documented by the formation of two separate groups of chromosomes, originating from either polar body/pronucleus (PB/PN), or only 2PN, which were tested by 5-colour FISH, or DNA analysis for copy number of chromosomes 13, 16, 18, 21, 22 and X. Two PN were formed more frequently than PB/PN, irrespective of incubation time. In agreement with recent reports on mouse oocytes, as many as 90.2% of the resulting haploid sets tested showed abnormal chromosome segregation, suggesting unsuitability of the resulting artificial gametes for practical application at the present time. PMID:15823223

  17. Cytogenetic Profile of Down Syndrome Cases Seen by a General Genetics Outpatient Service in Brazil

    ERIC Educational Resources Information Center

    Biselli, Joice; Goloni-Bertollo, Eny; Ruiz, Mariangela; Pavarino-Bertelli, Erika

    2009-01-01

    Down syndrome or trisomy 21 can be caused by three types of chromosomal abnormalities: free trisomy 21, translocation or mosaicism. The cytogenetic diagnosis, made through karyotypic examination, is important mainly to determine recurrence risks to assist genetic counselling. The object of this work was to carry out a cytogenetic profile of…

  18. 40 CFR 798.5385 - In vivo mammalian bone marrow cytogenetics tests: Chromosomal analysis.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... report. In addition to the reporting recommendations as specified under 40 CFR part 792, subpart J the... cytogenetics tests: Chromosomal analysis. 798.5385 Section 798.5385 Protection of Environment ENVIRONMENTAL... Genetic Toxicity § 798.5385 In vivo mammalian bone marrow cytogenetics tests: Chromosomal analysis....

  19. Methylphenidate and Amphetamine Do Not Induce Cytogenetic Damage in Lymphocytes of Children with ADHD

    ERIC Educational Resources Information Center

    Witt, Kristine L.; Shelby, Michael D.; Itchon-Ramos, Nilda; Faircloth, Melissa; Kissling, Grace E.; Chrisman, Allan K.; Ravi, Hima; Murli, Hemalatha; Mattison, Donald R.; Kollins, Scott H.

    2008-01-01

    The inducement of chromosomal damage in lymphocytes among children with attention deficit hyperactivity disorder receiving treatment with methylphenidate- or amphetamine-based drugs is investigated. Findings did not reveal significant increases in cytogenetic damage related to the treatment. The risk for cytogenetic damage posed by such products…

  20. Cytogenetic effect of 5-azacytidine in patients with hematological malignancies

    PubMed Central

    Tsuda, Jessica Romy; Segato, Rosimeire; Barbosa, Waldênia; Smith, Marília de Arruda Cardoso; Payão, Spencer Luiz Marques

    2011-01-01

    Background Recently, the importance of cytogenetics has grown in the diagnosis, prognosis and treatment of leukemias and myelodysplastic syndromes. 5-azacytidine is a drug that has well-known cytogenetical effects and is approved in the treatment of myelodysplastic syndromes. To date, no studies have been performed to evaluate the impact of 5-azacytidine on the chromosomes of patients with hematological neoplasias. This study aimed to investigate the effects of 5-azacytidine on chromosomes of patients with different hematological malignancies using G-band analyses to identify possible cytogenetical alterations. Methods The peripheral blood of 18 patients with hematological malignancies and 18 controls was collected in heparinized tubes. 5-azacytidine was added, at a final concentration of 10-5M, to cultures 7 hours prior to harvest. Results Uncoiled centromeric/pericentromeric heterochromatin of chromosomes-1, 9 and 16 occurred more frequently in the patients than in controls. This higher frequency of uncoiled heterochromatin was statistically significant (p-value = 0.004) for chromosome-9. Conversely, we observed that the fragile site at 19q13 was more frequent in controls (p-value = 0.0468). Conclusions The results of this study suggest that satellite sequences, located in the heterochromatin of chromosome-9, are hypomethylated in hematological malignancies. This hypomethylation may contribute to the disease, activating transposable elements and/or promoting genomic instability, enabling the loss of heterozygosity of important tumor suppressor genes. An investigation of the 19q13 region may help to understand whether or not the predominant occurrence of the fragile site at 19q13 in controls is due to hypermethylation of this region. PMID:23049342

  1. Evolutionary molecular cytogenetics of catarrhine primates: past, present and future.

    PubMed

    Stanyon, R; Rocchi, M; Bigoni, F; Archidiacono, N

    2012-01-01

    The catarrhine primates were the first group of species studied with comparative molecular cytogenetics. Many of the fundamental techniques and principles of analysis were initially applied to comparisons in these primates, including interspecific chromosome painting, reciprocal chromosome painting and the extensive use of cloned DNA probes for evolutionary analysis. The definition and importance of chromosome syntenies and associations for a correct cladistics analysis of phylogenomic relationships were first applied to catarrhines. These early chromosome painting studies vividly illustrated a striking conservation of the genome between humans and macaques. Contemporarily, it also revealed profound differences between humans and gibbons, a group of species more closely related to humans, making it clear that chromosome evolution did not follow a molecular clock. Chromosome painting has now been applied to more that 60 primate species and the translocation history has been mapped onto the major taxonomic divisions in the tree of primate evolution. In situ hybridization of cloned DNA probes, primarily BAC-FISH, also made it possible to more precisely map breakpoints with spanning and flanking BACs. These studies established marker order and disclosed intrachromosomal rearrangements. When applied comparatively to a range of primate species, they led to the discovery of evolutionary new centromeres as an important new category of chromosome evolution. BAC-FISH studies are intimately connected to genome sequencing, and probes can usually be assigned to a precise location in the genome assembly. This connection ties molecular cytogenetics securely to genome sequencing, assuring that molecular cytogenetics will continue to have a productive future in the multidisciplinary science of phylogenomics. PMID:22710640

  2. Design and Analysis of a Stiffened Composite Structure Repair Concept

    NASA Technical Reports Server (NTRS)

    Przekop, Adam

    2011-01-01

    A design and analysis of a repair concept applicable to a stiffened thin-skin composite panel based on the Pultruded Rod Stitched Efficient Unitized Structure is presented. Since the repair concept is a bolted repair using metal components, it can easily be applied in the operational environment. Initial analyses are aimed at validating the finite element modeling approach by comparing with available test data. Once confidence in the analysis approach is established several repair configurations are explored and the most efficient one presented. Repairs involving damage to the top of the stiffener alone are considered in addition to repairs involving a damaged stiffener, flange and underlying skin. High fidelity finite element modeling techniques such as mesh-independent definition of compliant fasteners, elastic-plastic metallic material properties and geometrically nonlinear analysis are utilized in the effort. The results of the analysis are presented and factors influencing the design are assessed and discussed.

  3. Arthroscopic rotator cuff repair.

    PubMed

    Burkhart, Stephen S; Lo, Ian K Y

    2006-06-01

    Arthroscopic rotator cuff repair is being performed by an increasing number of orthopaedic surgeons. The principles, techniques, and instrumentation have evolved to the extent that all patterns and sizes of rotator cuff tear, including massive tears, can now be repaired arthroscopically. Achieving a biomechanically stable construct is critical to biologic healing. The ideal repair construct must optimize suture-to-bone fixation, suture-to-tendon fixation, abrasion resistance of suture, suture strength, knot security, loop security, and restoration of the anatomic rotator cuff footprint (the surface area of bone to which the cuff tendons attach). By achieving optimized repair constructs, experienced arthroscopic surgeons are reporting results equal to those of open rotator cuff repair. As surgeons' arthroscopic skill levels increase through attendance at surgical skills courses and greater experience gained in the operating room, there will be an increasing trend toward arthroscopic repair of most rotator cuff pathology. PMID:16757673

  4. Nanotechnology and molecular cytogenetics: the future has not yet arrived

    PubMed Central

    Ioannou, Dimitris; Griffin, Darren K.

    2010-01-01

    Quantum dots (QDs) are a novel class of inorganic fluorochromes composed of nanometer-scale crystals made of a semiconductor material. They are resistant to photo-bleaching, have narrow excitation and emission wavelengths that can be controlled by particle size and thus have the potential for multiplexing experiments. Given the remarkable optical properties that quantum dots possess, they have been proposed as an ideal material for use in molecular cytogenetics, specifically the technique of fluorescent in situ hybridisation (FISH). In this review, we provide an account of the current QD-FISH literature, and speculate as to why QDs are not yet optimised for FISH in their current form. PMID:22110858

  5. Cytogenetic studies: an essential part of the paediatric necropsy.

    PubMed Central

    Sutherland, G R; Carter, R F

    1983-01-01

    Chromosome studies were attempted on 97% of necropsies carried out in the Department of Histopathology of the Adelaide Children's Hospital over the four-year period ending May 1981. Results were obtained from 89% of necropsies of which 7.5% had major chromosome abnormalities. The chromosome results are analysed according to the category of the necropsy and to primary cause of death. It is recommended that cytogenetic studies be performed on all stillbirths and infants dying at less than 28 days of age except in cases of isolated CNS malformation, sudden infant death syndrome (SIDS), trauma, or known single gene defects. PMID:6681820

  6. Cytogenetic changes induced by aqueous ferrofluids in agricultural plants

    NASA Astrophysics Data System (ADS)

    Răcuciu, Mihaela; Creangă, Dorina

    2007-04-01

    In this paper, the authors present their results regarding the cellular division rate and the percentage of chromosomal aberrations in the root meristematic cells of agricultural plants when cultivated in the presence of different concentrations of aqueous ferrofluid, ranging between 10 and 250 μL/L. The agricultural species ( Zea mays) with a major role in the life of people was chosen for the experimental project. The water-based ferrofluid was prepared following the chemical co-precipitation method, using tetramethylammonium hydroxide as magnetite core stabilizer. Microscopic investigations (cytogenetic tests) resulted in the evaluation of the mitotic and chromosomal aberration index. They appeared to increase following ferrofluid addition.

  7. Systems Maintenance Automated Repair Tasks (SMART)

    NASA Technical Reports Server (NTRS)

    2008-01-01

    SMART is an interactive decision analysis and refinement software system that uses evaluation criteria for discrepant conditions to automatically provide and populate a document/procedure with predefined steps necessary to repair a discrepancy safely, effectively, and efficiently. SMART can store the tacit (corporate) knowledge merging the hardware specification requirements with the actual "how to" repair methods, sequences, and required equipment, all within a user-friendly interface. Besides helping organizations retain repair knowledge in streamlined procedures and sequences, SMART can also help them in saving processing time and expense, increasing productivity, improving quality, and adhering more closely to safety and other guidelines. Though SMART was developed for Space Shuttle applications, its interface is easily adaptable to any hardware that can be broken down by component, subcomponent, discrepancy, and repair.

  8. Cytogenetic heterogeneity and their serial dynamic changes during acquisition of cytogenetic aberrations in cultured mesenchymal stem cells.

    PubMed

    Kim, Jung-Ah; Im, Kyong Ok; Park, Si Nae; Kwon, Ji Seok; Kim, Seon Young; Oh, Keunhee; Lee, Dong-Sup; Kim, Min Kyung; Kim, Seong Who; Jang, Mi; Lee, Gene; Oh, Yeon-Mok; Lee, Sang Do; Lee, Dong Soon

    2015-07-01

    To minimize the risk of tumorigenesis in mesenchymal stem cells (MSCs), G-banding analysis is widely used to detect chromosomal aberrations in MSCs. However, a critical limitation of G-banding is that it only reflects the status of metaphase cells, which can represent as few as 0.01% of tested cells. During routine cytogenetic testing in MSCs, we often detect chromosomal aberrations in minor cell populations. Therefore, we aimed to investigate whether such a minority of cells can expand over time or if they ultimately disappear during MSC passaging. We passaged MSCs serially while monitoring quantitative changes for each aberrant clone among heterogeneous MSCs. To investigate the cytogenetic status of interphase cells, which represent the main population, we also performed interphase FISH analysis, in combination with G-banding and telomere length determination. In human adipose tissue-derived MSCs, 4 types of chromosomal aberrations were found during culturing, and in umbilical cord MSCs, 2 types of chromosomal aberrations were observed. Sequential dynamic changes among heterogeneous aberrant clones during passaging were similar to the dynamic changes observed in cancer stem cells during disease progression. Throughout all passages, the quantitative G-banding results were inconsistent with those of the interphase FISH analysis. Interphase FISH revealed hidden aberrations in stem cell populations with normal karyotypes by G-banding analysis. We found that telomere length gradually decreased during passaging until the point at which cytogenetic aberrations appeared. The present study demonstrates that rare aberrant clones at earlier passages can become predominant clones during later passages. Considering the risk of tumorigenesis due to aberrant MSCs, we believe that our results will help to establish proper safety guidelines for MSC use. In particular, we believe it is critical to test for chromosomal aberrations using both G-banding and FISH to ensure the safety

  9. Rules of Engagement for Base Excision Repair in Chromatin

    PubMed Central

    Odell, Ian D.; Wallace, Susan S.; Pederson, David S.

    2012-01-01

    Most of the DNA in eukaryotes is packaged in tandemly arrayed nucleosomes that, together with numerous DNA- and nucleosome-associated enzymes and regulatory factors, make up chromatin. Chromatin modifying and remodeling agents help regulate access to selected DNA segments in chromatin, thereby facilitating transcription and DNA replication and repair. Studies of nucleotide excision repair (NER), single strand break repair (SSBR), and the homology-directed (HDR) and non-homologous end-joining (NHEJ) double strand break repair pathways have led to an ‘access-repair-restore’ paradigm, in which chromatin in the vicinity of damaged DNA is disrupted, thereby enabling efficient repair and the subsequent repackaging of DNA into nucleosomes. When damage is extensive, these repair processes are accompanied by cell cycle checkpoint activation, which provides cells with sufficient time to either complete the repair or initiate apoptosis. It is not clear, however, if base excision repair (BER) of the ~20,000 or more oxidative DNA damages that occur daily in each nucleated human cell can be viewed through this same lens. Until recently, we did not know if BER requires or is accompanied by nucleosome disruption, and it is not yet clear that anything short of overwhelming oxidative damage (resulting in the shunting of DNA substrates into other repair pathways) results in checkpoint activation. This review highlights studies of how oxidatively damaged DNA in nucleosomes is discovered and repaired, and offers a working model of events associated with BER in chromatin that we hope will have heuristic value. PMID:22718094

  10. First cytogenetic study of Cavernicola pilosa Barber, 1937 (Hemiptera, Triatominae).

    PubMed

    Souza, E S; Alevi, K C C; Ribeiro, A R; Furtado, M B; Atzingen, N C B V; Azeredo-Oliveira, M T V; Rosa, J A

    2015-01-01

    Cavernicola pilosa is a triatomine species that lives in caves and feeds on bat blood. This vector has a wide geographical distribution, and is found in Brazil, Colombia, Panama, Peru, and Venezuela. Little is known about the reproductive biology of this species, because most previous studies have only characterized its morphology, morphometry, ecology, and epidemiology. Therefore, this study aimed to obtain preliminary data related to spermatogenesis in C. pilosa by conducting cytogenetic analysis. Analysis of the heterochromatic pattern of C. pilosa during the initial prophases revealed that heterochromatic blocks are only present in the sex chromosomes. Based on the analyses of the meiotic metaphase and prophases, we found that the sex determination system of C. pilosa is XY and the chromosomes are holocentric. C. pilosa spermatids are filamentous and have long flagella. It was not possible to detect corpuscle or filament heteropycnosis in spermatids of this species. The initial cytogenetic data presented in this study are important in characterizing the spermatogenesis and heterochromatic patterns of C. pilosa. Our results suggest that adaptation to troglodytism did not result in differences in spermatogenesis in this vector. PMID:26535704

  11. Comparative cytogenetic analysis of marine needlefishes (Beloniformes) from southern Brazil.

    PubMed

    Cipriano, Roger Raupp; Noleto, Rafael Bueno; Kantek, Daniel Luis Zanella; da Silva Cortinhas, Maria Cristina; Cestari, Marta Margarete

    2016-08-01

    Cytogenetic studies have assisted in the taxonomic classification of organisms, especially those involving species with highly similar morphologic characteristics, or so-called cryptic species. Strongylura marina and Strongylura timucu collected from Paranaguá Bay, Paraná Coast in Southern Brazil are considered cryptic species, and the identification of interspecific variations based on the number and/or morphology of its chromosomes may serve as differentiating cytotaxonomic markers. Chromosomes of the two species were subjected to different banding and staining methods (C-, Ag-, and DAPI-CMA3), as well as chromosomal mapping of major rDNA (45S), revealed with an 18S probe by fluorescence in situ hybridization (FISH). The pattern of distribution of constitutive heterochromatin showed distinct features involving the pericentromeric and telomeric bands in both species. In S. marina, chromosome 1 represents the main species-specific marker, appearing almost entirely heterochromatic. In both species, the 45S rDNA is located at terminal region of the short arm of the chromosome 6, as detected by silver nitrate staining and FISH. Despite the apparent conserved diploid number of 48 chromosomes, data on the karyotype microstructure characterize the cytogenetic profile of the genus and may allow the establishment of cytotaxonomic and evolutionary inferences for these fishes. PMID:25388873

  12. Molecular and cytogenetic assessment of Dipterygium glaucum genotoxicity.

    PubMed

    Altwaty, Nada H; El-Sayed, Osama E; Aly, Nariman A H; Baeshen, Mohamed N; Baeshen, Nabih A

    2016-01-01

    The aim of the present study is to assess the genotoxicity of Dipterygium glaucum grows widely in Saudi Arabia desert to produce safety herbal products. This work is considered the first and pioneer report so far due to the lack and poor evaluated reports of the plant species for their mutagensity, genotoxicity and cytogenetics effects. Cytogenetic effects of D. glaucum on mitotic in roots of Vicia faba showed reduction in mitotic activity using three extracts; water, ethanol and ethyl acetate. Chromosomal abnormalities were recorded that included stickiness of chromosomes, chromatin bridge, fragments, lagging chromosome and micronuclei. Protein bands and RAPD analyses of V. faba treated with three D. glaucum extracts revealed some newly induced proteins and DNA fragments and other disappeared. Chemical constitution of the plant species should be identified with their biological activities against human and animal cells like HeLa cancer cell line. We are recommending using additional genotoxicity tests and other toxicity tests on animal culture with different concentrations and also utilizing several drought and heat tolerant genes of the plant species in gene cloning to develop and improve other economical crop plants instead of using the species as oral herbal remedy. PMID:27142548

  13. Cytogenetic Biodosimetry Using the Blood Lymphocytes of Astronauts

    NASA Technical Reports Server (NTRS)

    George, Kerry; Rhone, J.; Chappell, L. J.; Cucinotta, F. A.

    2010-01-01

    Cytogenetic analysis of blood lymphocytes remains the most sensitive and reliable method available for in vivo assessment of the biological effects of exposure to radiation and provides the most informative measurement of radiation induced health risks. To date chromosome damage has been assessed in lymphocytes from more than 30 astronauts before and after they participated in long-duration space missions of three months or more on board the International Space Station. For all individuals, the frequency of chromosome damage measured within a month of return from space was higher than their prefight yield and biodosimetry estimates lie within the range expected from physical dosimetry. Biodosimetry data provides a direct measurement of space radiation damage, which takes into account individual radiosensitivity in the presence of confounding factors such as microgravity and other stress conditions. In contrast to physical measurements, which are external to body and require multiple devices to detect all radiation types all of which have poor sensitivity to neutrons, biodosimetry is internal and includes the effects of shielding provided by the body itself plus chromosome damage shows excellent sensitivity to protons, heavy ions, and neutrons. In addition, chromosome damage is reflective of cancer risk and biodosimetry values can therefore be used to validate and develop risk assessment models that can be used to characterize excess health risk incurred by crewmembers. A review of astronaut biodosimetry data will be presented along with recent findings on the persistence of space radiation induced chromosome damage and the cytogenetic effects of repeat long duration missions

  14. Cytogenetic map of common bean (Phaseolus vulgaris L.)

    PubMed Central

    Fonsêca, Artur; Ferreira, Joana; dos Santos, Tiago Ribeiro Barros; Mosiolek, Magdalena; Bellucci, Elisa; Kami, James; Gepts, Paul; Geffroy, Valérie; Schweizer, Dieter; dos Santos, Karla G. B.

    2010-01-01

    A cytogenetic map of common bean was built by in situ hybridization of 35 bacterial artificial chromosomes (BACs) selected with markers mapping to eight linkage groups, plus two plasmids for 5S and 45S ribosomal DNA and one bacteriophage. Together with three previously mapped chromosomes (chromosomes 3, 4, and 7), 43 anchoring points between the genetic map and the cytogenetic map of the species are now available. Furthermore, a subset of four BAC clones was proposed to identify the 11 chromosome pairs of the standard cultivar BAT93. Three of these BACs labelled more than a single chromosome pair, indicating the presence of repetitive DNA in their inserts. A repetitive distribution pattern was observed for most of the BACs; for 38% of them, highly repetitive pericentromeric or subtelomeric signals were observed. These distribution patterns corresponded to pericentromeric and subtelomeric heterochromatin blocks observed with other staining methods. Altogether, the results indicate that around half of the common bean genome is heterochromatic and that genes and repetitive sequences are intermingled in the euchromatin and heterochromatin of the species. Electronic supplementary material The online version of this article (doi:10.1007/s10577-010-9129-8) contains supplementary material, which is available to authorized users. PMID:20449646

  15. A cytogenetic study of papaya workers exposed to ethylene dibromide.

    PubMed

    Steenland, K; Carrano, A; Ratcliffe, J; Clapp, D; Ashworth, L; Meinhardt, T

    1986-06-01

    Ethylene dibromide (EDB) has been shown to be carcinogenic in animal studies and mutagenic in vitro. One cytogenetic study of workers exposed to low levels of EDB for short durations was negative. To test whether exposure to low levels of EDB over long periods caused cytogenetic changes, we have assessed the frequencies of sister-chromatid exchanges (SCE) and chromosomal aberrations (CA) in the peripheral blood lymphocytes of 60 men occupationally exposed to EDB. These men worked in papaya-packing plants where EDB was used to fumigate the fruit after harvest to kill fruit-fly larvae. 42 other men who worked at a nearby sugar mill served as controls. The average duration of exposure of the papaya workers was 5 years. 82 full shift personal breathing-zone air samples indicated that the papaya workers were exposed to a geometric mean of 88 ppb of EDB, as an 8-h time weighted average (TWA). Peaks up to 262 ppb were measured. The proposed OSHA 8-h TWA for EDB is 100 ppb, while NIOSH recommends 45 ppb. No differences in SCE levels were found between exposed and nonexposed workers. No differences were found in the total CA frequency between exposed and nonexposed workers. SCE levels were significantly increased in men who smoked cigarettes (p = 0.0001) and in men who smoked marijuana (p = 0.01). CA levels showed a significant increasing trend with age (p = 0.03). PMID:3520305

  16. Snowmobile Repair. Teacher Edition.

    ERIC Educational Resources Information Center

    Hennessy, Stephen S.; Conrad, Rex

    This teacher's guide contains 14 units on snowmobile repair: (1) introduction to snowmobile repair; (2) skis, front suspension, and steering; (3) drive clutch; (4) drive belts; (5) driven clutch; (6) chain drives; (7) jackshafts and axles; (8) rear suspension; (9) tracks; (10) shock absorbers; (11) brakes; (12) engines; (13) ignition and…

  17. INTERNAL REPAIR OF PIPELINES

    SciTech Connect

    Bill Bruce; Nancy Porter; George Ritter; Matt Boring; Mark Lozev; Ian Harris; Bill Mohr; Dennis Harwig; Robin Gordon; Chris Neary; Mike Sullivan

    2005-07-20

    The two broad categories of fiber-reinforced composite liner repair and deposited weld metal repair technologies were reviewed and evaluated for potential application for internal repair of gas transmission pipelines. Both are used to some extent for other applications and could be further developed for internal, local, structural repair of gas transmission pipelines. Principal conclusions from a survey of natural gas transmission industry pipeline operators can be summarized in terms of the following performance requirements for internal repair: (1) Use of internal repair is most attractive for river crossings, under other bodies of water, in difficult soil conditions, under highways, under congested intersections, and under railway crossings. (2) Internal pipe repair offers a strong potential advantage to the high cost of horizontal direct drilling when a new bore must be created to solve a leak or other problem. (3) Typical travel distances can be divided into three distinct groups: up to 305 m (1,000 ft.); between 305 m and 610 m (1,000 ft. and 2,000 ft.); and beyond 914 m (3,000 ft.). All three groups require pig-based systems. A despooled umbilical system would suffice for the first two groups which represents 81% of survey respondents. The third group would require an onboard self-contained power unit for propulsion and welding/liner repair energy needs. (4) The most common size range for 80% to 90% of operators surveyed is 508 mm (20 in.) to 762 mm (30 in.), with 95% using 558.8 mm (22 in.) pipe. Evaluation trials were conducted on pipe sections with simulated corrosion damage repaired with glass fiber-reinforced composite liners, carbon fiber-reinforced composite liners, and weld deposition. Additional un-repaired pipe sections were evaluated in the virgin condition and with simulated damage. Hydrostatic failure pressures for pipe sections repaired with glass fiber-reinforced composite liner were only marginally greater than that of pipe sections without

  18. Occurrence and prognostic significance of cytogenetic evolution in patients with multiple myeloma

    PubMed Central

    Binder, M; Rajkumar, S V; Ketterling, R P; Dispenzieri, A; Lacy, M Q; Gertz, M A; Buadi, F K; Hayman, S R; Hwa, Y L; Zeldenrust, S R; Lust, J A; Russell, S J; Leung, N; Kapoor, P; Go, R S; Gonsalves, W I; Kyle, R A; Kumar, S K

    2016-01-01

    Cytogenetic evaluation at the time of diagnosis is essential for risk stratification in multiple myeloma, however little is known about the occurrence and prognostic significance of cytogenetic evolution during follow-up. We studied 989 patients with multiple myeloma, including 304 patients with at least two cytogenetic evaluations. Multivariable-adjusted regression models were used to assess the associations between the parameters of interest and cytogenetic evolution as well as overall survival. The prognostic significance of baseline cytogenetic abnormalities was most pronounced at the time of diagnosis and attenuated over time. In the patients with serial cytogenetic evaluations, the presence of t(11;14) at the time of diagnosis was associated with decreased odds of cytogenetic evolution during follow-up (odds ratio (OR)=0.22, 95% confidence interval (CI)=0.09–0.56, P=0.001), while the presence of at least one trisomy or tetrasomy was associated with increased odds (OR=2.96, 95% CI=1.37–6.42, P=0.006). The development of additional abnormalities during the 3 years following diagnosis was associated with increased subsequent mortality (hazard ratio=3.31, 95% CI=1.73–6.30, P<0.001). These findings emphasize the importance of the underlying clonal disease process for risk assessment and suggest that selected patients may benefit from repeated risk stratification. PMID:26967818

  19. INTERNAL REPAIR OF PIPELINES

    SciTech Connect

    Robin Gordon; Bill Bruce; Ian Harris; Dennis Harwig; George Ritter; Bill Mohr; Matt Boring; Nancy Porter; Mike Sullivan; Chris Neary

    2004-12-31

    The two broad categories of fiber-reinforced composite liner repair and deposited weld metal repair technologies were reviewed and evaluated for potential application for internal repair of gas transmission pipelines. Both are used to some extent for other applications and could be further developed for internal, local, structural repair of gas transmission pipelines. Principal conclusions from a survey of natural gas transmission industry pipeline operators can be summarized in terms of the following performance requirements for internal repair: (1) Use of internal repair is most attractive for river crossings, under other bodies of water, in difficult soil conditions, under highways, under congested intersections, and under railway crossings. (2) Internal pipe repair offers a strong potential advantage to the high cost of horizontal direct drilling when a new bore must be created to solve a leak or other problem. (3) Typical travel distances can be divided into three distinct groups: up to 305 m (1,000 ft.); between 305 m and 610 m (1,000 ft. and 2,000 ft.); and beyond 914 m (3,000 ft.). All three groups require pig-based systems. A despooled umbilical system would suffice for the first two groups which represents 81% of survey respondents. The third group would require an onboard self-contained power unit for propulsion and welding/liner repair energy needs. (4) The most common size range for 80% to 90% of operators surveyed is 508 mm (20 in.) to 762 mm (30 in.), with 95% using 558.8 mm (22 in.) pipe. Evaluation trials were conducted on pipe sections with simulated corrosion damage repaired with glass fiber-reinforced composite liners, carbon fiber-reinforced composite liners, and weld deposition. Additional un-repaired pipe sections were evaluated in the virgin condition and with simulated damage. Hydrostatic failure pressures for pipe sections repaired with glass fiber-reinforced composite liner were only marginally greater than that of pipe sections without

  20. Nuclear position dictates DNA repair pathway choice

    PubMed Central

    Lemaître, Charlène; Grabarz, Anastazja; Tsouroula, Katerina; Andronov, Leonid; Furst, Audrey; Pankotai, Tibor; Heyer, Vincent; Rogier, Mélanie; Attwood, Kathleen M.; Kessler, Pascal; Dellaire, Graham; Klaholz, Bruno; Reina-San-Martin, Bernardo; Soutoglou, Evi

    2014-01-01

    Faithful DNA repair is essential to avoid chromosomal rearrangements and promote genome integrity. Nuclear organization has emerged as a key parameter in the formation of chromosomal translocations, yet little is known as to whether DNA repair can efficiently occur throughout the nucleus and whether it is affected by the location of the lesion. Here, we induce DNA double-strand breaks (DSBs) at different nuclear compartments and follow their fate. We demonstrate that DSBs induced at the nuclear membrane (but not at nuclear pores or nuclear interior) fail to rapidly activate the DNA damage response (DDR) and repair by homologous recombination (HR). Real-time and superresolution imaging reveal that DNA DSBs within lamina-associated domains do not migrate to more permissive environments for HR, like the nuclear pores or the nuclear interior, but instead are repaired in situ by alternative end-joining. Our results are consistent with a model in which nuclear position dictates the choice of DNA repair pathway, thus revealing a new level of regulation in DSB repair controlled by spatial organization of DNA within the nucleus. PMID:25366693

  1. Concepts in Gene Therapy for Cartilage Repair

    PubMed Central

    Steinert, Andre F.; Nöth, Ulrich; Tuan, Rocky S.

    2009-01-01

    Summary Once articular cartilage is injured, it has a very limited capacity for self-repair. Although current surgical therapeutic procedures to cartilage repair are clinically useful, they cannot restore a normal articular surface. Current research offers a growing number of bioactive reagents, including proteins and nucleic acids, that may be used to augment different aspects of the repair process. As these agents are difficult to administer effectively, gene transfer approaches are being developed to provide their sustained synthesis at sites of repair. To augment regeneration of articular cartilage, therapeutic genes can be delivered to the synovium, or directly to the cartilage lesion. Gene delivery to the cells of the synovial lining is generally considered more suitable for chondroprotective approaches, based on the expression of anti-inflammatory mediators. Gene transfer targeted to cartilage defects can be achieved by either direct vector administration to cells located at or surrounding the defects, or by transplantation of genetically modified chondrogenic cells into the defect. Several studies have shown that exogenous cDNAs encoding growth factors can be delivered locally to sites of cartilage damage, where they are expressed at therapeutically relevant levels. Furthermore, data is beginning to emerge indicating, that efficient delivery and expression of these genes is capable of influencing a repair response toward the synthesis of a more hyaline cartilage repair tissue in vivo. This review presents the current status of gene therapy for cartilage healing and highlights some of the remaining challenges. PMID:18313477

  2. Cytogenetics of the true bug infraorder Cimicomorpha (Hemiptera, Heteroptera): a review

    PubMed Central

    Kuznetsova, Valentina G.; Grozeva, Snejana M.; Nokkala, Seppo; Nokkala, Christina

    2011-01-01

    Abstract The Cimicomorpha is one of the largest and highly diversified infraorders of the Heteroptera. This group is also highly diversified cytogenetically and demonstrates a number of unusual cytogenetic characters such as holokinetic chromosomes; m-chromosomes; multiple sex chromosome systems; post-reduction of sex chromosomes in meiosis; variation in the presence/absence of chiasmata in spermatogenesis; different types of achiasmate meiosis. We present here a review of essential cytogenetic characters of the Cimicomorpha and outline the chief objectives and goals of future investigations in the field. PMID:22287915

  3. Acetylation regulates DNA repair mechanisms in human cells.

    PubMed

    Piekna-Przybylska, Dorota; Bambara, Robert A; Balakrishnan, Lata

    2016-06-01

    The p300-mediated acetylation of enzymes involved in DNA repair and replication has been previously shown to stimulate or inhibit their activities in reconstituted systems. To explore the role of acetylation on DNA repair in cells we constructed plasmid substrates carrying inactivating damages in the EGFP reporter gene, which should be repaired in cells through DNA mismatch repair (MMR) or base excision repair (BER) mechanisms. We analyzed efficiency of repair within these plasmid substrates in cells exposed to deacetylase and acetyltransferase inhibitors, and also in cells deficient in p300 acetyltransferase. Our results indicate that protein acetylation improves DNA mismatch repair in MMR-proficient HeLa cells and also in MMR-deficient HCT116 cells. Moreover, results suggest that stimulated repair of mismatches in MMR-deficient HCT116 cells is done though a strand-displacement synthesis mechanism described previously for Okazaki fragments maturation and also for the EXOI-independent pathway of MMR. Loss of p300 reduced repair of mismatches in MMR-deficient cells, but did not have evident effects on BER mechanisms, including the long patch BER pathway. Hypoacetylation of the cells in the presence of acetyltransferase inhibitor, garcinol generally reduced efficiency of BER of 8-oxoG damage, indicating that some steps in the pathway are stimulated by acetylation. PMID:27104361

  4. INTERNAL REPAIR OF PIPELINES

    SciTech Connect

    Robin Gordon; Bill Bruce; Ian Harris; Dennis Harwig; George Ritter; Bill Mohr; Matt Boring; Nancy Porter; Mike Sullivan; Chris Neary

    2004-08-17

    The two broad categories of fiber-reinforced composite liner repair and deposited weld metal repair technologies were reviewed and evaluated for potential application for internal repair of gas transmission pipelines. Both are used to some extent for other applications and could be further developed for internal, local, structural repair of gas transmission pipelines. Principal conclusions from a survey of natural gas transmission industry pipeline operators can be summarized in terms of the following performance requirements for internal repair: (1) Use of internal repair is most attractive for river crossings, under other bodies of water, in difficult soil conditions, under highways, under congested intersections, and under railway. (2) Internal pipe repair offers a strong potential advantage to the high cost of horizontal direct drilling when a new bore must be created to solve a leak or other problem. (3) Typical travel distances can be divided into three distinct groups: up to 305 m (1,000 ft.); between 305 m and 610 m (1,000 ft. and 2,000 ft.); and beyond 914 m (3,000 ft.). All three groups require pig-based systems. A despooled umbilical system would suffice for the first two groups which represents 81% of survey respondents. The third group would require an onboard self-contained power unit for propulsion and welding/liner repair energy needs. (4) The most common size range for 80% to 90% of operators surveyed is 508 mm (20 in.) to 762 mm (30 in.), with 95% using 558.8 mm (22 in.) pipe. Evaluation trials were conducted on pipe sections with simulated corrosion damage repaired with glass fiber-reinforced composite liners, carbon fiber-reinforced composite liners, and weld deposition. Additional un-repaired pipe sections were evaluated in the virgin condition and with simulated damage. Hydrostatic failure pressures for pipe sections repaired with glass fiber-reinforced composite liner were only marginally greater than that of pipe sections without liners

  5. EUVL Mask Blank Repair

    SciTech Connect

    Barty, A; Mirkarimi, P; Stearns, D G; Sweeney, D; Chapman, H N; Clift, M; Hector, S; Yi, M

    2002-05-22

    EUV mask blanks are fabricated by depositing a reflective Mo/Si multilayer film onto super-polished substrates. Small defects in this thin film coating can significantly alter the reflected field and introduce defects in the printed image. Ideally one would want to produce defect-free mask blanks; however, this may be very difficult to achieve in practice. One practical way to increase the yield of mask blanks is to effectively repair multilayer defects, and to this effect they present two complementary defect repair strategies for use on multilayer-coated EUVL mask blanks. A defect is any area on the mask which causes unwanted variations in EUV dose in the aerial image obtained in a printing tool, and defect repair is correspondingly defined as any strategy that renders a defect unprintable during exposure. The term defect mitigation can be adopted to describe any strategy which renders a critical defect non-critical when printed, and in this regard a non-critical defect is one that does not adversely affect device function. Defects in the patterned absorber layer consist of regions where metal, typically chrome, is unintentionally added or removed from the pattern leading to errors in the reflected field. There currently exists a mature technology based on ion beam milling and ion beam assisted deposition for repairing defects in the absorber layer of transmission lithography masks, and it is reasonable to expect that this technology will be extended to the repair of absorber defects in EUVL masks. However, techniques designed for the repair of absorber layers can not be directly applied to the repair of defects in the mask blank, and in particular the multilayer film. In this paper they present for the first time a new technique for the repair of amplitude defects as well as recent results on the repair of phase defects.

  6. In vivo cytogenetic activity of diphenylhydantoin in mice.

    PubMed

    McFee, A F; Tice, R R; Shelby, M D

    1992-01-01

    Diphenylhydantoin was tested in vivo in mice using a variety of cytogenetic endpoints to evaluate its genotoxicity. Injected doses of 125, 250 and 500 mg/kg failed to increase the number of chromosome aberrations in marrow cells at 17 h post-treatment, and 37.5, 75 and 150 mg/kg doses were likewise ineffective at 36 h. SCEs were significantly increased by doses of 125 mg/kg (but not 250 mg) after 23 h and modestly, in relation to dose, at 42 h. No increase in the number of micronuclei among marrow PCEs was seen following single i.v. injections ranging from 0.1 to 20 mg/kg. Three daily i.p. injections of doses up to 70 mg/kg also failed to increase the number of micronuclei in either marrow or peripheral blood PCEs. Some cytotoxic effect was evident following relatively high doses. PMID:1370120

  7. Cytogenetic characterization of Partamona cupira (Hymenoptera, Apidae) by fluorochromes

    PubMed Central

    2010-01-01

    Four colonies of the stingless bee Partamona cupira (Hymenoptera: Apidae) were cytogenetically analyzed using conventional staining and the fluorochromes CMA3 e DAPI. The females have 2n = 34 chromosomes (2K = 32 M¯+2 A¯). Some females, however, presented an additional large B acrocentric chromosome, to a total of 2n = 35. Chromosome B and the chromosomal pairs 2, 9 and 10 showed CMA 3+ bands, indicating an excess of CG base-pairs. A clear association was verified between the P. helleri B chromosome SCAR marker and the presence of a B chromosome in P. cupira. The data obtained suggests that B chromosomes in P. helleri and P. cupira share a common origin. PMID:21637478

  8. radir package: an R implementation for cytogenetic biodosimetry dose estimation.

    PubMed

    Moriña, David; Higueras, Manuel; Puig, Pedro; Ainsbury, Elizabeth A; Rothkamm, Kai

    2015-09-01

    The Bayesian framework has been shown to be very useful in cytogenetic dose estimation. This approach allows description of the probability of an event in terms of previous knowledge, e.g. its expectation and/or its uncertainty. A new R package entitled radir (radiation inverse regression) has been implemented with the aim of reproducing a recent Bayesian-type dose estimation methodology. radir adopts the method of dose estimation under the Poisson assumption of the responses (the chromosomal aberrations counts) for the required dose-response curve (typically linear or quadratic). The individual commands are described in detail and relevant examples of the use of the methods and the corresponding radir software tools are given. The suitability of this methodology is highlighted and its application encouraged by providing a user-friendly command-type software interface within the R statistical software (version 3.1.1 or higher), which includes a complete manual. PMID:26160852

  9. Utility of array comparative genomic hybridization in cytogenetic analysis.

    PubMed

    Singh, Rashmi R; Cheung, K-John J; Horsman, Douglas E

    2011-01-01

    Conventional comparative genomic hybridization (CGH), high-resolution oligonucleotide, and BAC array CGH have modernized the field of cytogenetics to enable access to unbalanced genomic aberrations such as whole or partial chromosomal gains and losses. The basic principle of array CGH involves hybridizing differentially labeled proband/test (e.g., tumor) and normal reference DNA on an array of oligonucleotide or BAC clones instead of normal metaphases as in conventional CGH. The sub-megabase resolution tiling BAC arrays are extremely useful for the analysis of acquired aberrations in cancer genomes. Array CGH can be extremely useful to identify the chromosomal makeup of marker and ring chromosomes, to define/delineate the precise location/bands involved in structural aberrations and the accurate localization of translocation breakpoints in both simple and complex karyotypes either alone or in combination with standard karyotype analysis. PMID:21431645

  10. Testing hygrometers used in cytogenetics laboratories for metaphase preparation.

    PubMed

    Hartley, Thomas; Dun, Karen

    2011-07-01

    This protocol describes procedures for checking small laboratory hygrometers for accuracy at three relative humidity (rh) levels. The work arose out of the need to provide laboratory assessors with documentary evidence that the hygrometer used to monitor humidity in the vicinity of the laboratory where medical cytogenetics testing slides are prepared and dried in the ambient environment is reproducible and sufficiently accurate. The procedure is based upon the physicochemical principle that when water or certain saturated salt solutions are placed into a sealed environment, the humidity will equilibrate to well defined levels. We choose to check our hygrometers at three points: 95%, 75%, and 33% rh, using distilled water, saturated sodium chloride solution, and saturated magnesium chloride solution, respectively. Our results have demonstrated that the procedure is convenient and of sufficient accuracy to be fit for this annual hygrometer validation purpose. The procedure takes 24 hr per relative humidity point checked. PMID:21735375

  11. Cytogenetic evaluation of chromosomal disorders in Down Syndrome

    SciTech Connect

    Shafik, H.M.

    1987-01-01

    Down Syndrome (DS) patients are at high risk to develop leukemia. They are also highly sensitive to the induction of chromosomal aberrations when their GO lymphocytes are irradiated in vitro. The objective of this study was to further investigate the differential radiosensitivity of DS lymphocytes at the different stages of the cell cycle, as damage to proliferating cells is more relevant to health problems than damage to non-dividing cells. In addition, the proliferation kinetics and stage of differentiation of circulating DS lymphocytes was studied in an attempt to understand the mechanism for the enhanced chromosomal radiosensitivity. Moreover, the x-ray induced specific chromosomal breakpoints were identified and correlated with the locations of oncogene and fragile sites in order to investigate cytogenetically the early stages of leukemogenesis.

  12. Interphase cytogenetic and AgNOR analyses of hydatidiform moles.

    PubMed Central

    Watanabe, M; Ghazizadeh, M; Konishi, H; Araki, T

    1998-01-01

    AIM: To determine the potential value of interphase cytogenetic and argyrophilic nucleolar organiser region (AgNOR) analyses in the diagnosis and classification of hydatidiform moles. METHODS: Serial tissue sections from 37 hydatidiform moles, histologically classified as 11 complete and 15 partial, and from 11 hydropic abortuses were examined by in situ hybridisation using digoxigenin labelled probes specific for chromosomes 1, X, and Y, and a one step silver staining method. The percentages of diploid and triploid nuclei, and the mean number of AgNORs for each tissue were determined. RESULTS: Interphase cytogenetics showed that eight of the 11 cases (73%) each of complete mole and hydropic abortus had diploid pattern and the three remaining cases (27%) of each group were triploid. Two of the triploid complete moles and one of the triploid hydropic abortuses were revised to partial moles and one remaining triploid complete mole was revised to hydropic abortus. Of the 15 partial moles, nine (60%) were triploid, and six (40%) were diploid. These diploid cases were revised to three complete moles and three hydropic abortuses. There was a significant difference (p < 0.0001) between the mean (SD) AgNOR count in partial mole (5.11 (0.91)) versus hydropic abortus (3.79 (0.90)) and complete mole (3.39 (0.97)). The total of 15 triploid cases showed a high mean AgNOR count of 5.24 (0.73). Also, after reclassification, eight of the nine partial moles (89%) had a mean AgNOR count of > or = 5. The results of analyses by the two methods were closely correlated. CONCLUSIONS: Interphasecytogeneticanalysis using chromosome specific probes and AgNOR count provides a valuable approach for ploidy analysis in histological sections of hydatidiform moles and helps to resolve difficult cases. Images PMID:9771442

  13. Nonrandom chromosomal aberrations and cytogenetic heterogeneity in gallbladder carcinomas.

    PubMed

    Gorunova, L; Parada, L A; Limon, J; Jin, Y; Hallén, M; Hägerstrand, I; Iliszko, M; Wajda, Z; Johansson, B

    1999-12-01

    Chromosome banding analysis of 11 short-term cultured gallbladder carcinomas revealed acquired clonal aberrations in seven tumors (five primary and two metastases). Three of these had one clone, whereas the remaining four were cytogenetically heterogeneous, displaying two to seven aberrant clones. Of a total of 21 abnormal clones, 18 had highly complex karyotypes and three exhibited simple numerical deviations. Double minutes and homogeneously staining regions were observed in one and two carcinomas, respectively. To characterize the karyotypic profile of gallbladder cancer more precisely, we have combined the present findings with our three previously reported cases, thereby providing the largest cytogenetic database on this tumor type to date. A total of 287 chromosomal breakpoints were identified, 251 of which were found in the present study. Chromosome 7 was rearranged most frequently, followed by chromosomes 1, 3, 11, 6, 5, and 8. The bands preferentially involved were 1p32, 1p36, 1q32, 3p21, 6p21, 7p13, 7q11, 7q32, 19p13, 19q13, and 22q13. Nine recurrent abnormalities could, for the first time, be identified in gallbladder carcinoma: del(3)(p13), i(5)(p10), del(6)(q13), del(9)(p13), del(16)(q22), del(17)(p11), i(17)(q10), del(19)(p13), and i(21)(q10). The most common partial or whole-arm gains involved 3q, 5p, 7p, 7q, 8q, 11q, 13q, and 17q, and the most frequent partial or whole-arm losses affected 3p, 4q, 5q, 9p, 10p, 10q, 11p, 14p, 14q, 15p, 17p, 19p, 21p, 21q, and Xp. These chromosomal aberrations and imbalances provide some starting points for molecular analyses of genomic regions that may harbor genes of pathogenetic importance in gallbladder carcinogenesis. Genes Chromosomes Cancer 26:312-321, 1999. PMID:10534766

  14. Molecular Cytogenetic Analysis of Deschampsia antarctica Desv. (Poaceae), Maritime Antarctic.

    PubMed

    Amosova, Alexandra V; Bolsheva, Nadezhda L; Samatadze, Tatiana E; Twardovska, Maryana O; Zoshchuk, Svyatoslav A; Andreev, Igor O; Badaeva, Ekaterina D; Kunakh, Viktor A; Muravenko, Olga V

    2015-01-01

    Deschampsia antarctica Desv. (Poaceae) (2n = 26) is one of the two vascular plants adapted to the harshest environment of the Antarctic. Although the species is a valuable model for study of environmental stress tolerance in plants, its karyotype is still poorly investigated. We firstly conducted a comprehensive molecular cytogenetic analysis of D. antarctica collected on four islands of the Maritime Antarctic. D. antarctica karyotypes were studied by Giemsa C- and DAPI/C-banding, Ag-NOR staining, multicolour fluorescence in situ hybridization with repeated DNA probes (pTa71, pTa794, telomere repeats, pSc119.2, pAs1) and the GAA simple sequence repeat probe. We also performed sequential rapid in situ hybridization with genomic DNA of D. caespitosa. Two chromosome pairs bearing transcriptionally active 45S rDNA loci and five pairs with 5S rDNA sites were detected. A weak intercalary site of telomere repeats was revealed on the largest chromosome in addition to telomere hybridization signals at terminal positions. This fact confirms indirectly the hypothesis that chromosome fusion might have been the cause of the unusual for cereals chromosome number in this species. Based on patterns of distribution of the examined molecular cytogenetic markers, all chromosomes in karyotypes were identified, and chromosome idiograms of D. antarctica were constructed. B chromosomes were found in most karyotypes of plants from Darboux Island. A mixoploid plant with mainly triploid cells bearing a Robertsonian rearrangement was detected among typical diploid specimens from Great Jalour Island. The karyotype variability found in D. antarctica is probably an expression of genome instability induced by environmental stress factors. The differences in C-banding patterns and in chromosome distribution of rDNA loci as well as homologous highly repeated DNA sequences detected between genomes of D. antarctica and its related species D. caespitosa indicate that genome reorganization involving

  15. Molecular Cytogenetic Analysis of Deschampsia antarctica Desv. (Poaceae), Maritime Antarctic

    PubMed Central

    Amosova, Alexandra V.; Bolsheva, Nadezhda L.; Samatadze, Tatiana E.; Twardovska, Maryana O.; Zoshchuk, Svyatoslav A.; Andreev, Igor O.; Badaeva, Ekaterina D.; Kunakh, Viktor A.; Muravenko, Olga V.

    2015-01-01

    Deschampsia antarctica Desv. (Poaceae) (2n = 26) is one of the two vascular plants adapted to the harshest environment of the Antarctic. Although the species is a valuable model for study of environmental stress tolerance in plants, its karyotype is still poorly investigated. We firstly conducted a comprehensive molecular cytogenetic analysis of D. antarctica collected on four islands of the Maritime Antarctic. D. antarctica karyotypes were studied by Giemsa C- and DAPI/C-banding, Ag-NOR staining, multicolour fluorescence in situ hybridization with repeated DNA probes (pTa71, pTa794, telomere repeats, pSc119.2, pAs1) and the GAA simple sequence repeat probe. We also performed sequential rapid in situ hybridization with genomic DNA of D. caespitosa. Two chromosome pairs bearing transcriptionally active 45S rDNA loci and five pairs with 5S rDNA sites were detected. A weak intercalary site of telomere repeats was revealed on the largest chromosome in addition to telomere hybridization signals at terminal positions. This fact confirms indirectly the hypothesis that chromosome fusion might have been the cause of the unusual for cereals chromosome number in this species. Based on patterns of distribution of the examined molecular cytogenetic markers, all chromosomes in karyotypes were identified, and chromosome idiograms of D. antarctica were constructed. B chromosomes were found in most karyotypes of plants from Darboux Island. A mixoploid plant with mainly triploid cells bearing a Robertsonian rearrangement was detected among typical diploid specimens from Great Jalour Island. The karyotype variability found in D. antarctica is probably an expression of genome instability induced by environmental stress factors. The differences in C-banding patterns and in chromosome distribution of rDNA loci as well as homologous highly repeated DNA sequences detected between genomes of D. antarctica and its related species D. caespitosa indicate that genome reorganization involving

  16. Cytogenetic biodosimetry using the blood lymphocytes of astronauts

    NASA Astrophysics Data System (ADS)

    George, Kerry A.; Rhone, Jordan; Chappell, Lori J.; Cucinotta, Francis A.

    2013-11-01

    Cytogenetic analysis of peripheral blood lymphocytes is the most sensitive and reliable method currently available for in vivo assessment of the biological effects of exposure to radiation and provides the most informative measurement of radiation induced health risks. Data indicates that space missions of a few months or more can induce measureable increases in the yield of chromosome damage in the blood lymphocytes of astronauts that can be used to estimate an organ dose equivalent, and biodosimetry estimates lie within the range expected from physical dosimetry. Space biodosimetry poses some unique challenges compared to terrestrial biological assessments of radiation exposures, but data provides a direct measurement of space radiation damage, which takes into account individual radiosensitivity in the presence of confounding factors such as microgravity and other stress conditions. Moreover if chromosome damage persists in the blood for many years, results can be used for retrospective dose reconstruction. In contrast to physical measurements, which are external to body and require multiple devices to detect all radiation types all of which have poor sensitivity to neutrons, biodosimetry is internal and includes the effects of shielding provided by the body itself plus chromosome damage shows excellent sensitivity to protons, heavy ions, and neutrons. In addition, chromosome damage is reflective of cancer risk and biodosimetry values can therefore be used to validate and develop risk assessment models that can be used to characterize health risk incurred by crewmembers. The current paper presents a review of astronaut biodosimetry data, along with recently derived data on the relative cancer risk estimated using the quantitative approach derived from the European Study Group on Cytogenetic Biomarkers and Health database.

  17. Analysis and Test of Repair Concepts for a Carbon-Rod Reinforced Laminate

    NASA Technical Reports Server (NTRS)

    Baker, Donald J.; Rousseau, Carl Q.

    2000-01-01

    The use of pultruded carbon-epoxy rods for the reinforcement of composite laminates in some structures results in an efficient structural concept. The results of an analytical and experimental investigation of repair concepts of completely severed carbon-epoxy rods is presented. Three repair concepts are considered: (a) bonded repair with outside moldline and inside moldline doublers; (b) bonded repair with fasteners, and (c) bonded repair with outside moldline doubler only. The stiffness of the repairs was matched with the stiffness of the baseline specimen. The failure strains for the bonded repair with fasteners and the bonded repair with an outside moldline doubler exceeded a target design strain set for the repair concepts.

  18. EEPD1 Rescues Stressed Replication Forks and Maintains Genome Stability by Promoting End Resection and Homologous Recombination Repair

    PubMed Central

    Wu, Yuehan; Lee, Suk-Hee; Williamson, Elizabeth A.; Reinert, Brian L.; Cho, Ju Hwan; Xia, Fen; Jaiswal, Aruna Shanker; Srinivasan, Gayathri; Patel, Bhavita; Brantley, Alexis; Zhou, Daohong; Shao, Lijian; Pathak, Rupak; Hauer-Jensen, Martin; Singh, Sudha; Kong, Kimi; Wu, Xaiohua; Kim, Hyun-Suk; Beissbarth, Timothy; Gaedcke, Jochen; Burma, Sandeep; Nickoloff, Jac A.; Hromas, Robert A.

    2015-01-01

    Replication fork stalling and collapse is a major source of genome instability leading to neoplastic transformation or cell death. Such stressed replication forks can be conservatively repaired and restarted using homologous recombination (HR) or non-conservatively repaired using micro-homology mediated end joining (MMEJ). HR repair of stressed forks is initiated by 5’ end resection near the fork junction, which permits 3’ single strand invasion of a homologous template for fork restart. This 5’ end resection also prevents classical non-homologous end-joining (cNHEJ), a competing pathway for DNA double-strand break (DSB) repair. Unopposed NHEJ can cause genome instability during replication stress by abnormally fusing free double strand ends that occur as unstable replication fork repair intermediates. We show here that the previously uncharacterized Exonuclease/Endonuclease/Phosphatase Domain-1 (EEPD1) protein is required for initiating repair and restart of stalled forks. EEPD1 is recruited to stalled forks, enhances 5’ DNA end resection, and promotes restart of stalled forks. Interestingly, EEPD1 directs DSB repair away from cNHEJ, and also away from MMEJ, which requires limited end resection for initiation. EEPD1 is also required for proper ATR and CHK1 phosphorylation, and formation of gamma-H2AX, RAD51 and phospho-RPA32 foci. Consistent with a direct role in stalled replication fork cleavage, EEPD1 is a 5’ overhang nuclease in an obligate complex with the end resection nuclease Exo1 and BLM. EEPD1 depletion causes nuclear and cytogenetic defects, which are made worse by replication stress. Depleting 53BP1, which slows cNHEJ, fully rescues the nuclear and cytogenetic abnormalities seen with EEPD1 depletion. These data demonstrate that genome stability during replication stress is maintained by EEPD1, which initiates HR and inhibits cNHEJ and MMEJ. PMID:26684013

  19. Human DNA repair genes.

    PubMed

    Wood, R D; Mitchell, M; Sgouros, J; Lindahl, T

    2001-02-16

    Cellular DNA is subjected to continual attack, both by reactive species inside cells and by environmental agents. Toxic and mutagenic consequences are minimized by distinct pathways of repair, and 130 known human DNA repair genes are described here. Notable features presently include four enzymes that can remove uracil from DNA, seven recombination genes related to RAD51, and many recently discovered DNA polymerases that bypass damage, but only one system to remove the main DNA lesions induced by ultraviolet light. More human DNA repair genes will be found by comparison with model organisms and as common folds in three-dimensional protein structures are determined. Modulation of DNA repair should lead to clinical applications including improvement of radiotherapy and treatment with anticancer drugs and an advanced understanding of the cellular aging process. PMID:11181991

  20. Laparoscopic Ventral Hernia Repair

    MedlinePlus

    ... the likelihood of a hernia including persistent coughing, difficulty with bowel movements or urination, or frequent need for straining. What are the Advantages of Laparoscopic Ventral Hernia Repair? Keep reading... Page 1 of 2 1 2 » Brought to ...

  1. Easily repairable networks

    NASA Astrophysics Data System (ADS)

    Fink, Thomas

    2015-03-01

    We introduce a simple class of distribution networks which withstand damage by being repairable instead of redundant. Instead of asking how hard it is to disconnect nodes through damage, we ask how easy it is to reconnect nodes after damage. We prove that optimal networks on regular lattices have an expected cost of reconnection proportional to the lattice length, and that such networks have exactly three levels of structural hierarchy. We extend our results to networks subject to repeated attacks, in which the repairs themselves must be repairable. We find that, in exchange for a modest increase in repair cost, such networks are able to withstand any number of attacks. We acknowledge support from the Defense Threat Reduction Agency, BCG and EU FP7 (Growthcom).

  2. Eye muscle repair - slideshow

    MedlinePlus

    ... page: //medlineplus.gov/ency/presentations/100062.htm Eye muscle repair - series—Normal anatomy To use the sharing ... the eyeball to the eye socket. The external muscles of the eye are found behind the conjunctiva. ...

  3. INTERNAL REPAIR OF PIPELINES

    SciTech Connect

    Robin Gordon; Bill Bruce; Ian Harris; Dennis Harwig; Nancy Porter; Mike Sullivan; Chris Neary

    2004-04-12

    The two broad categories of deposited weld metal repair and fiber-reinforced composite liner repair technologies were reviewed for potential application for internal repair of gas transmission pipelines. Both are used to some extent for other applications and could be further developed for internal, local, structural repair of gas transmission pipelines. Preliminary test programs were developed for both deposited weld metal repair and for fiber-reinforced composite liner repair. Evaluation trials have been conducted using a modified fiber-reinforced composite liner provided by RolaTube and pipe sections without liners. All pipe section specimens failed in areas of simulated damage. Pipe sections containing fiber-reinforced composite liners failed at pressures marginally greater than the pipe sections without liners. The next step is to evaluate a liner material with a modulus of elasticity approximately 95% of the modulus of elasticity for steel. Preliminary welding parameters were developed for deposited weld metal repair in preparation of the receipt of Pacific Gas & Electric's internal pipeline welding repair system (that was designed specifically for 559 mm (22 in.) diameter pipe) and the receipt of 559 mm (22 in.) pipe sections from Panhandle Eastern. The next steps are to transfer welding parameters to the PG&E system and to pressure test repaired pipe sections to failure. A survey of pipeline operators was conducted to better understand the needs and performance requirements of the natural gas transmission industry regarding internal repair. Completed surveys contained the following principal conclusions: (1) Use of internal weld repair is most attractive for river crossings, under other bodies of water, in difficult soil conditions, under highways, under congested intersections, and under railway crossings. (2) Internal pipe repair offers a strong potential advantage to the high cost of horizontal direct drilling (HDD) when a new bore must be created to

  4. Tracheoesophageal fistula repair - slideshow

    MedlinePlus

    ... page: //medlineplus.gov/ency/presentations/100103.htm Tracheoesophageal fistula repair - series To use the sharing features on ... Editorial team. Related MedlinePlus Health Topics Esophagus Disorders Fistulas Tracheal Disorders A.D.A.M., Inc. is ...

  5. Bone fracture repair - slideshow

    MedlinePlus

    ... page: //medlineplus.gov/ency/presentations/100077.htm Bone fracture repair - series To use the sharing features on ... to slide 4 out of 4 Indications Overview Fractures of the bones are classified in a number ...

  6. Pectus excavatum repair

    MedlinePlus

    ... surgery to repair this condition -- open surgery and closed (minimally invasive) surgery. Either surgery is done while ... At the end of surgery, the incision is closed. The metal struts are removed in 6 to ...

  7. Anterior vaginal wall repair

    MedlinePlus

    ... Cystocele Anterior vaginal wall repair (surgical treatment of urinary incontinence) - series References Lentz GM. Anatomic defects of the ... 72. Read More Anterior Inflatable artificial sphincter Stress urinary incontinence Urinary catheters Urinary incontinence - injectable implant Urinary incontinence - ...

  8. Imperforate anus repair - slideshow

    MedlinePlus

    ... presentations/100030.htm Imperforate anus repair - series—Normal anatomy To use the sharing features on this page, ... of 4 Overview In individuals with a normal anatomy, the large intestine (colon) empties into a pouch- ...

  9. Meningocele repair - slideshow

    MedlinePlus

    ... ency/presentations/100128.htm Meningocele repair - series—Normal anatomy To use the sharing features on this page, ... Sinai Medical Center, Los Angeles and Department of Anatomy, University of California, San Francisco, CA. Review provided ...

  10. Robotic inguinal hernia repair.

    PubMed

    Escobar Dominguez, Jose E; Gonzalez, Anthony; Donkor, Charan

    2015-09-01

    Inguinal hernias have been described throughout the history of medicine with many efforts to achieve the cure. Currently, with the advantages of minimally invasive surgery, new questions arise: what is going to be the best approach for inguinal hernia repair? Is there a real benefit with the robotic approach? Should minimally invasive hernia surgery be the standard of care? In this report we address these questions by describing our experience with robotic inguinal hernia repair. PMID:26153353

  11. Repairing Foam Insulation

    NASA Technical Reports Server (NTRS)

    Corbin, J.; Buras, D.

    1986-01-01

    Large holes in polyurethane foam insulation repaired reliably by simple method. Little skill needed to apply method, used for overhead repairs as well as for those in other orientations. Plug positioned in hole to be filled and held in place with mounting fixture. Fresh liquid foam injected through plug to bond it in place. As foam cures and expands, it displaces plug outward. Protrusion later removed.

  12. Low-grade central osteosarcoma of the metatarsal bone: a clinicopathological, immunohistochemical, cytogenetic and molecular cytogenetic analysis.

    PubMed

    Nishio, Jun; Iwasaki, Hiroshi; Takagi, Satoshi; Seo, Hajime; Aoki, Mikiko; Nabeshima, Kazuki; Naito, Masatoshi

    2012-12-01

    Low-grade central osteosarcoma (LGCOS) is a very rare low-grade malignant neoplasm that is often confused with a variety of benign fibro-osseous lesions. It rarely involves the small tubular bones of the feet. We present an unusual case of LGCOS arising in the third metatarsal bone of a 16-year-old boy. The radiographic appearance was suggestive of a benign lesion. An open biopsy was performed and the initial diagnosis was fibrous dysplasia. The patient underwent curettage of the lesion and packing of the bony defect with a synthetic bone substitute. Histologically, the curetted specimens consisted of spindle cells admixed with irregular bony trabeculae and osteoid. The spindle cells were fairly uniform with mild atypia, and cellularity varied from low to high. Immunohistochemistry showed that the tumor cells were focally-positive for cyclin-dependent kinase 4 and p53, but negative for murine double minute-2. The MIB-1 labeling index was 36.7% in the highest focus. Cytogenetic analysis exhibited the following clonal karyotypic abnormalities: 48,XY,del(6)(p11),add(8)(q24),add(12)(p11.2),+mar1,+mar-2. Spectral karyotyping demonstrated that marker chromosomes were composed mainly of chromosome 6. Metaphase-based comparative genomic hybridization analysis showed a high-level amplification of 6p12-p21 and gains of 8q21-q24, 10p15, 12q13-q15, and 16q23-q24. Based on these findings, the final diagnosis was revised to LGCOS and the patient was treated with an additional wide excision, followed by reconstruction with a free-vascularized osteocutaneous scapular flap. At 18 months of follow-up, the patient is well with no evidence of local recurrence or distant metastasis. Our case highlights the diagnostic difficulty of this tumor with limited tissue samples and the importance of immunohistochemical and molecular cytogenetic analyses in ambiguous cases. PMID:23225447

  13. Advances in laboratory evaluation of Turner syndrome and its variants: beyond cytogenetics studies.

    PubMed

    Wolff, D J

    2000-11-01

    Turner syndrome is a clinically defined phenotype that is characterized by partial or complete X chromosome monosomy. A host of cytogenetic aberrations and mosaicism have been associated with this syndrome. Some individuals, Turner syndrome variants, have cytogenetic findings consistent with Turner syndrome, but exhibit atypical clinical phenotypes. Recently, several molecular tests have been presented to allow for the refined clinical study of Turner syndrome and its variants. PMID:11216383

  14. Significance of Persistent Cytogenetic Abnormalities at Myeloablative Allogeneic Stem Cell Transplantation in First Complete Remission

    PubMed Central

    Oran, Betul; Popat, Uday; Rondon, Gabriella; Ravandi, Farhad; Garcia-Manero, Guillermo; Abruzzo, Lynn; Andersson, Borje S.; Bashir, Qaiser; Chen, Julianne; Kebriaei, Partow; Khouri, Issa F.; Koca, Ebru; Qazilbash, Muzaffar H.; Champlin, Richard; de Lima, Marcos

    2014-01-01

    Risk stratification is important to identify acute myeloid leukemia (AML) patients that might benefit from allogeneic hematopoietic stem cell transplantation (allo-HCT) in first complete remission (CR1). We retrospectively studied 150 AML patients with diagnostic cytogenetic abnormalities receiving myeloablative allo-HCT in CR1 to determine the prognostic impact of persistent cytogenetic abnormalities at allo-HCT. Three risk groups were identified: First group of patients with favorable/intermediate cytogenetics at diagnosis (n=49) and the second group with unfavorable cytogenetics at diagnosis but without the presence of persistent abnormal clone at allo-HCT (n=83) had similar 3-year leukemia free survival (LFS) of 58%-60% despite increased 3-year relapse incidence (RI) of 32.3% observed in the second risk group versus 16.8% in the first group. Third group of patients with unfavorable cytogenetics at diagnosis and persistence of that clone at allo-HCT (n=15) represented the worst prognostic group with 3-year RI of 57.5% and 3-year LFS of 29.2%. These data suggest that AML patients with unfavorable cytogenetics at diagnosis and persistence of abnormal clone at allo-HCT have high risk of relapse after allo-HCT. These patients should be considered for clinical trials designed to optimize conditioning regimens and/or to use preemptive strategies in the post-transplant setting to decrease the relapse incidence. PMID:22982533

  15. Precision in chromosome identification with leads in molecular cytogenetics: An illustrated review

    PubMed Central

    Dutta, Usha R.

    2014-01-01

    Chromosomal aberrations are a major cause of human genetic diseases. Conventional cytogenetic banding techniques are the method of identification for both numerical and structural chromosomal abnormalities but with limited resolution. However, precise identification and characterization of the chromosomal abnormalities can only be achieved by advanced molecular cytogenetic techniques. These techniques are based mainly on fluorescence in situ hybridization, which have become an invaluable tool in the field of diagnostics. The advent of these molecular cytogenetic techniques has helped in the identification of chromosomal abnormalities to its minutest level. Apparently, the leads in molecular cytogenetic techniques have paved way for advanced molecular diagnosis, which now plays a significant role in both diagnostics and clinical research. These advances have led to the increased knowledge of the possible molecular mechanism involved in the chromosomal rearrangements and the genotype-phenotype correlation thus helping the patients towards better diagnosis and genetic counseling. This article highlights the advances in molecular cytogenetic techniques emphasizing the precision in identification of chromosomal rearrangements, and also illustrates few chromosomal abnormalities pediatric cases identified using these molecular cytogenetic techniques.

  16. Integrated cytogenetics and genomics analysis of transposable elements in the Nile tilapia, Oreochromis niloticus.

    PubMed

    Valente, Guilherme; Kocher, Thomas; Eickbush, Thomas; Simões, Rafael P; Martins, Cesar

    2016-06-01

    Integration of cytogenetics and genomics has become essential to a better view of architecture and function of genomes. Although the advances on genomic sequencing have contributed to study genes and genomes, the repetitive DNA fraction of the genome is still enigmatic and poorly understood. Among repeated DNAs, transposable elements (TEs) are major components of eukaryotic chromatin and their investigation has been hindered even after the availability of whole sequenced genomes. The cytogenetic mapping of TEs in chromosomes has proved to be of high value to integrate information from the micro level of nucleotide sequence to a cytological view of chromosomes. Different TEs have been cytogenetically mapped in cichlids; however, neither details about their genomic arrangement nor appropriated copy number are well defined by these approaches. The current study integrates TEs distribution in Nile tilapia Oreochromis niloticus genome based on cytogenetic and genomics/bioinformatics approach. The results showed that some elements are not randomly distributed and that some are genomic dependent on each other. Moreover, we found extensive overlap between genomics and cytogenetics data and that tandem duplication may be the major mechanism responsible for the genomic dynamics of TEs here analyzed. This paper provides insights in the genomic organization of TEs under an integrated view based on cytogenetics and genomics. PMID:26860923

  17. Relationships of the Woody Medicago Species (Section Dendrotelis) Assessed by Molecular Cytogenetic Analyses

    PubMed Central

    Rosato, Marcela; Castro, Mercedes; Rosselló, Josep A.

    2008-01-01

    cytogenetic data do not suggest the hypothesis that M. arborea and M. strasseri were involved in the origin of M. citrina. FISH mapping can be used as an efficient tool to determine the genomic contribution of M. citrina in somatic hybrids with other medic species. PMID:18413655

  18. The importance of age and smoking in evaluating adverse cytogenetic effects of exposure to environmental agents

    SciTech Connect

    Tucker, J.D.; Moore, D.H. II

    1995-08-01

    Fluorescence in situ hybridization with chromosome-specific composite DNA probes (``chromosome painting``) is a reliable and efficient method for detecting structural chromosome aberrations. Painting is now being used to quantify chromosome damage in many human populations. In one such study we evaluated 91 unexposed people ranging in age from birth (cord bloods) to 79. We established a baseline frequency of stable aberrations that showed a highly significant curvi-linear increase with age (p < 0.00001) that accounted for 70% of the variance between donors. The magnitude of this effect illustrates the importance of understanding the cytogenetic changes that occur with age, which is particularly important for quantifying the effects of prior adverse environmental, occupational, or accidental exposure. In this paper we use the data obtained in our previous study to characterize the distribution of stable aberrations by age and pack-years of cigarette smoking. We also provide estimates of the number of cell equivalents that need to be scored to detect a given increase in aberrations above the background level surveyed in this population.

  19. Ontology Alignment Repair through Modularization and Confidence-Based Heuristics.

    PubMed

    Santos, Emanuel; Faria, Daniel; Pesquita, Catia; Couto, Francisco M

    2015-01-01

    Ontology Matching aims at identifying a set of semantic correspondences, called an alignment, between related ontologies. In recent years, there has been a growing interest in efficient and effective matching methods for large ontologies. However, alignments produced for large ontologies are often logically incoherent. It was only recently that the use of repair techniques to improve the coherence of ontology alignments began to be explored. This paper presents a novel modularization technique for ontology alignment repair which extracts fragments of the input ontologies that only contain the necessary classes and relations to resolve all detectable incoherences. The paper presents also an alignment repair algorithm that uses a global repair strategy to minimize both the degree of incoherence and the number of mappings removed from the alignment, while overcoming the scalability problem by employing the proposed modularization technique. Our evaluation shows that our modularization technique produces significantly small fragments of the ontologies and that our repair algorithm produces more complete alignments than other current alignment repair systems, while obtaining an equivalent degree of incoherence. Additionally, we also present a variant of our repair algorithm that makes use of the confidence values of the mappings to improve alignment repair. Our repair algorithm was implemented as part of AgreementMakerLight, a free and open-source ontology matching system. PMID:26710335

  20. Isolating human DNA repair genes using rodent-cell mutants

    SciTech Connect

    Thompson, L.H.; Weber, C.A.; Brookman, K.W.; Salazar, E.P.; Stewart, S.A.; Mitchell, D.L.

    1987-03-23

    The DNA repair systems of rodent and human cells appear to be at least as complex genetically as those in lower eukaryotes and bacteria. The use of mutant lines of rodent cells as a means of identifying human repair genes by functional complementation offers a new approach toward studying the role of repair in mutagenesis and carcinogenesis. In each of six cases examined using hybrid cells, specific human chromosomes have been identified that correct CHO cell mutations affecting repair of damage from uv or ionizing radiations. This finding suggests that both the repair genes and proteins may be virtually interchangeable between rodent and human cells. Using cosmid vectors, human repair genes that map to chromosome 19 have cloned as functional sequences: ERCC2 and XRCC1. ERCC1 was found to have homology with the yeast excision repair gene RAD10. Transformants of repair-deficient cell lines carrying the corresponding human gene show efficient correction of repair capacity by all criteria examined. 39 refs., 1 fig., 1 tab.

  1. Plasma Membrane Repair in Health and Disease.

    PubMed

    Demonbreun, Alexis R; McNally, Elizabeth M

    2016-01-01

    Since an intact membrane is required for normal cellular homeostasis, membrane repair is essential for cell survival. Human genetic studies, combined with the development of novel animal models and refinement of techniques to study cellular injury, have now uncovered series of repair proteins highly relevant for human health. Many of the deficient repair pathways manifest in skeletal muscle, where defective repair processes result in myopathies or other forms of muscle disease. Dysferlin is a membrane-associated protein implicated in sarcolemmal repair and also linked to other membrane functions including the maintenance of transverse tubules in muscle. MG53, annexins, and Eps15 homology domain-containing proteins interact with dysferlin to form a membrane repair complex and similarly have roles in membrane trafficking in muscle. These molecular features of membrane repair are not unique to skeletal muscle, but rather skeletal muscle, due to its high demands, is more dependent on an efficient repair process. Phosphatidylserine and phosphatidylinositol 4,5-bisphosphate, as well as Ca(2+), are central regulators of membrane organization during repair. Given the importance of muscle health in disease and in aging, these pathways are targets to enhance muscle function and recovery from injury. PMID:26781830

  2. Ontology Alignment Repair through Modularization and Confidence-Based Heuristics

    PubMed Central

    Santos, Emanuel; Faria, Daniel; Pesquita, Catia; Couto, Francisco M.

    2015-01-01

    Ontology Matching aims at identifying a set of semantic correspondences, called an alignment, between related ontologies. In recent years, there has been a growing interest in efficient and effective matching methods for large ontologies. However, alignments produced for large ontologies are often logically incoherent. It was only recently that the use of repair techniques to improve the coherence of ontology alignments began to be explored. This paper presents a novel modularization technique for ontology alignment repair which extracts fragments of the input ontologies that only contain the necessary classes and relations to resolve all detectable incoherences. The paper presents also an alignment repair algorithm that uses a global repair strategy to minimize both the degree of incoherence and the number of mappings removed from the alignment, while overcoming the scalability problem by employing the proposed modularization technique. Our evaluation shows that our modularization technique produces significantly small fragments of the ontologies and that our repair algorithm produces more complete alignments than other current alignment repair systems, while obtaining an equivalent degree of incoherence. Additionally, we also present a variant of our repair algorithm that makes use of the confidence values of the mappings to improve alignment repair. Our repair algorithm was implemented as part of AgreementMakerLight, a free and open-source ontology matching system. PMID:26710335

  3. Repair of UV damage in Halobacterium salinarum.

    PubMed

    McCready, S; Marcello, L

    2003-06-01

    Halobacterium is one of the few known Archaea that tolerates high levels of sunlight in its natural environment. Photoreactivation is probably its most important strategy for surviving UV irradiation and we have shown that both of the major UV photoproducts, cyclobutane pyrimidine dimers (CPDs) and (6-4) photoproducts, can be very efficiently repaired by photoreactivation in this organism. There are two putative photolyase gene homologues in the published genome sequence of Halobacterium sp. NRC-1. We have made a mutant deleted in one of these, phr2, and confirmed that this gene codes for a CPD photolyase. (6-4) photoproducts are still photoreactivated in the mutant so we are currently establishing whether the other homologue, phr1, codes for a (6-4) photolyase. We have also demonstrated an excision repair capacity that operates in the absence of visible light but the nature of this pathway is not yet known. There is probably a bacteria-type excision-repair mechanism, since homologues of uvrA, uvrB, uvrC and uvrD have been identified in the Halobacterium genome. However, there are also homologues of eukaryotic nucleotide-excision-repair genes ( Saccharomyces cerevisiae RAD3, RAD25 and RAD2 ) so there may be multiple repair mechanisms for UV damage in Halobacterium. PMID:12773185

  4. Mechanical injury and repair of cells

    NASA Technical Reports Server (NTRS)

    Miyake, Katsuya; McNeil, Paul L.

    2003-01-01

    OBJECTIVE: To concisely review the field of cell plasma membrane disruption (torn cell surface) and repair. MAIN POINTS: Plasma membrane disruption is a common form of cell injury under physiologic conditions, after trauma, in certain muscular dystrophies, and during certain forms of clinical intervention. Rapid repair of a disruption is essential to cell survival and involves a complex and active cell response that includes membrane fusion and cytoskeletal activation. Tissues, such as cardiac and skeletal muscle, adapt to a disruption injury by hypertrophying. Cells adapt by increasing the efficiency of their resealing response. CONCLUSION: Plasma membrane disruption is an important cellular event in both health and disease. The disruption repair mechanism is now well understood at the cellular level, but much remains to be learned at the molecular level. Cell and tissue level adaptational responses to the disruption either prevent its further occurrence or facilitate future repairs. Therapeutically useful drugs might result if, using this accumulating knowledge, chemical agents can be developed that can enhance repair or adaptive responses.

  5. Assays for DNA double-strand break repair by microhomology-based end-joining repair mechanisms

    PubMed Central

    Kostyrko, Kaja; Mermod, Nicolas

    2016-01-01

    DNA double stranded breaks (DSBs) are one of the most deleterious types of DNA lesions. The main pathways responsible for repairing these breaks in eukaryotic cells are homologous recombination (HR) and non-homologous end-joining (NHEJ). However, a third group of still poorly characterized DSB repair pathways, collectively termed microhomology-mediated end-joining (MMEJ), relies on short homologies for the end-joining process. Here, we constructed GFP reporter assays to characterize and distinguish MMEJ variant pathways, namely the simple MMEJ and the DNA synthesis-dependent (SD)-MMEJ mechanisms. Transfection of these assay vectors in Chinese hamster ovary (CHO) cells and characterization of the repaired DNA sequences indicated that while simple MMEJ is able to mediate relatively efficient DSB repair if longer microhomologies are present, the majority of DSBs were repaired using the highly error-prone SD-MMEJ pathway. To validate the involvement of DNA synthesis in the repair process, siRNA knock-down of different genes proposed to play a role in MMEJ were performed, revealing that the knock-down of DNA polymerase θ inhibited DNA end resection and repair through simple MMEJ, thus favoring the other repair pathway. Overall, we conclude that this approach provides a convenient assay to study MMEJ-related DNA repair pathways. PMID:26657630

  6. Cytogenetics of Triticum x Dasypyrum hybrids and derived lines.

    PubMed

    Minelli, S; Ceccarelli, M; Mariani, M; De Pace, C; Cionini, P G

    2005-01-01

    Genomic in situ hybridization was used to study Triticum x Dasypyrum wide hybrids and derived lines. A cytogenetic investigation was carried out in progenies of (i) amphiploids derived from T. turgidum var. durum (T. durum; 2n = 14; genomes AABB) x D. villosum (2n = 14; genome VV), (ii) three-parental hybrids (T. durum x D. villosum) x T. aestivum (2n = 42, genomes A'A'B'B'D'D'), and (iii) T. aestivum aneuploid lines carrying D. villosum chromosomes or chromatin. The amphiploids derived from T. durum x D. villosum showed a stable chromosomal constitution, made up of 14 V chromosomes, 14 chromosomes carrying the wheat A genome and 14 chromosomes carrying the B genome. High karyological instability was observed in the progenies of three-parental hybrids ([T. durum x D. villosum] x T. aestivum). Plants having the expected 14 A chromosomes, 14 B chromosomes, 7 D chromosomes, and 7 V chromosomes were rather rare (4.5%). Many progeny plants (45.5%) had the hexaploid wheat genome with 42 chromosomes and lacked any detectable D. villosum chromatin. Other plants (50%) had 14 A chromosomes and 14 B chromosomes, plus variable numbers of D and V chromosomes, the former being better retained than the latter in most cases. Some T. aestivum lines carrying D. villosum chromosomes or chromatin, as the result of addition, substitution, or recombination events or even a combination of these karyological events, were found to be stable. Other lines were unstable, and these lines carried 1V, 3V, or 5V chromosomes or their portions. Substitution or recombination events where 1V chromosomes were involved could concern the homeologous counterparts in both the A and B and D genomes of wheat. No line could be recovered where the shorter arm of 3V chromosomes was present. Changes in the morphology and banding pattern of V chromosomes were observed in hybrids that did not carry the entire D. villosum complement. By comparing the results of our cytogenetic analyses with certain phenotypic

  7. DNA repair genes are selectively mutated in diffuse large B cell lymphomas

    PubMed Central

    de Miranda, Noel FCC; Peng, Roujun; Georgiou, Konstantinos; Wu, Chenglin; Sörqvist, Elin Falk; Berglund, Mattias; Chen, Longyun; Gao, Zhibo; Lagerstedt, Kristina; Lisboa, Susana; Roos, Fredrik; van Wezel, Tom; Teixeira, Manuel R.; Rosenquist, Richard; Sundström, Christer; Enblad, Gunilla; Nilsson, Mats; Zeng, Yixin; Kipling, David

    2013-01-01

    DNA repair mechanisms are fundamental for B cell development, which relies on the somatic diversification of the immunoglobulin genes by V(D)J recombination, somatic hypermutation, and class switch recombination. Their failure is postulated to promote genomic instability and malignant transformation in B cells. By performing targeted sequencing of 73 key DNA repair genes in 29 B cell lymphoma samples, somatic and germline mutations were identified in various DNA repair pathways, mainly in diffuse large B cell lymphomas (DLBCLs). Mutations in mismatch repair genes (EXO1, MSH2, and MSH6) were associated with microsatellite instability, increased number of somatic insertions/deletions, and altered mutation signatures in tumors. Somatic mutations in nonhomologous end-joining (NHEJ) genes (DCLRE1C/ARTEMIS, PRKDC/DNA-PKcs, XRCC5/KU80, and XRCC6/KU70) were identified in four DLBCL tumors and cytogenetic analyses revealed that translocations involving the immunoglobulin-heavy chain locus occurred exclusively in NHEJ-mutated samples. The novel mutation targets, CHEK2 and PARP1, were further screened in expanded DLBCL cohorts, and somatic as well as novel and rare germline mutations were identified in 8 and 5% of analyzed tumors, respectively. By correlating defects in a subset of DNA damage response and repair genes with genomic instability events in tumors, we propose that these genes play a role in DLBCL lymphomagenesis. PMID:23960188

  8. Arthroscopic hip labral repair.

    PubMed

    Philippon, Marc J; Faucet, Scott C; Briggs, Karen K

    2013-05-01

    Labral tears in the hip may cause painful clicking or locking of the hip, reduced range of motion, and disruption to sports and daily activities. The acetabular labrum aids stabilization of the hip joint, particularly during hip motion. The fibrocartilaginous structure extends the acetabular rim and provides a suction seal around the femoroacetabular interface. Treatment options for labral tears include debridement, repair, and reconstruction. Repair of the labrum has been shown to have better results than debridement. Labral refixation is achieved with sutures anchored into the acetabular rim. The acetabular rim is trimmed either to correct pincer impingement or to provide a bleeding bed to improve healing. Labral repair has shown excellent short-term to midterm outcomes and allows patients to return to activities and sports. Arthroscopic rim trimming and labral refixation comprise an effective treatment for labral tears with an underlying diagnosis of femoroacetabular impingement and are supported by the peer-reviewed literature. PMID:23875153

  9. Rescheduling with iterative repair

    NASA Technical Reports Server (NTRS)

    Zweben, Monte; Davis, Eugene; Daun, Brian; Deale, Michael

    1992-01-01

    This paper presents a new approach to rescheduling called constraint-based iterative repair. This approach gives our system the ability to satisfy domain constraints, address optimization concerns, minimize perturbation to the original schedule, produce modified schedules, quickly, and exhibits 'anytime' behavior. The system begins with an initial, flawed schedule and then iteratively repairs constraint violations until a conflict-free schedule is produced. In an empirical demonstration, we vary the importance of minimizing perturbation and report how fast the system is able to resolve conflicts in a given time bound. We also show the anytime characteristics of the system. These experiments were performed within the domain of Space Shuttle ground processing.

  10. Rescheduling with iterative repair

    NASA Technical Reports Server (NTRS)

    Zweben, Monte; Davis, Eugene; Daun, Brian; Deale, Michael

    1992-01-01

    This paper presents a new approach to rescheduling called constraint-based iterative repair. This approach gives our system the ability to satisfy domain constraints, address optimization concerns, minimize perturbation to the original schedule, and produce modified schedules quickly. The system begins with an initial, flawed schedule and then iteratively repairs constraint violations until a conflict-free schedule is produced. In an empirical demonstration, we vary the importance of minimizing perturbation and report how fast the system is able to resolve conflicts in a given time bound. These experiments were performed within the domain of Space Shuttle ground processing.

  11. DNA Damage Repair in the Context of Plant Chromatin1

    PubMed Central

    Donà, Mattia; Mittelsten Scheid, Ortrun

    2015-01-01

    The integrity of DNA molecules is constantly challenged. All organisms have developed mechanisms to detect and repair multiple types of DNA lesions. The basic principles of DNA damage repair (DDR) in prokaryotes and unicellular and multicellular eukaryotes are similar, but the association of DNA with nucleosomes in eukaryotic chromatin requires mechanisms that allow access of repair enzymes to the lesions. This is achieved by chromatin-remodeling factors, and their necessity for efficient DDR has recently been demonstrated for several organisms and repair pathways. Plants share many features of chromatin organization and DNA repair with fungi and animals, but they differ in other, important details, which are both interesting and relevant for our understanding of genome stability and genetic diversity. In this Update, we compare the knowledge of the role of chromatin and chromatin-modifying factors during DDR in plants with equivalent systems in yeast and humans. We emphasize plant-specific elements and discuss possible implications. PMID:26089404

  12. DNA Damage Repair in the Context of Plant Chromatin.

    PubMed

    Donà, Mattia; Mittelsten Scheid, Ortrun

    2015-08-01

    The integrity of DNA molecules is constantly challenged. All organisms have developed mechanisms to detect and repair multiple types of DNA lesions. The basic principles of DNA damage repair (DDR) in prokaryotes and unicellular and multicellular eukaryotes are similar, but the association of DNA with nucleosomes in eukaryotic chromatin requires mechanisms that allow access of repair enzymes to the lesions. This is achieved by chromatin-remodeling factors, and their necessity for efficient DDR has recently been demonstrated for several organisms and repair pathways. Plants share many features of chromatin organization and DNA repair with fungi and animals, but they differ in other, important details, which are both interesting and relevant for our understanding of genome stability and genetic diversity. In this Update, we compare the knowledge of the role of chromatin and chromatin-modifying factors during DDR in plants with equivalent systems in yeast and humans. We emphasize plant-specific elements and discuss possible implications. PMID:26089404

  13. Mechanisms of transcription-repair coupling and mutation frequency decline.

    PubMed Central

    Selby, C P; Sancar, A

    1994-01-01

    Mutation frequency decline is the rapid and irreversible decline in the suppressor mutation frequency of Escherichia coli cells if the cells are kept in nongrowth media immediately following the mutagenic treatment. The gene mfd, which is necessary for mutation frequency decline, encodes a protein of 130 kDa which couples transcription to excision repair by binding to RNA polymerase and to UvrA, which is the damage recognition subunit of the excision repair enzyme. Although current evidence suggests that transcription-repair coupling is the cause of the preferential repair of the transcribed strand of mRNA encoding genes as well as of suppressor tRNA genes, the decline occurs under stringent response conditions in which the tRNA genes are not efficiently transcribed. Thus, the mechanism of strand-specific repair is well understood, but some questions remain regarding the precise mechanism of mutation frequency decline. PMID:7968917

  14. Assessment of occupational cytogenetic risk, among petrol station workers.

    PubMed

    Bindhya, Sadhanandhan; Balachandar, Vellingiri; Sudha, Sellapa; Mohana Devi, Subramaniam; Varsha, Prakash; Kandasamy, Kanagaraj; Gnana Prakash, Visvanathan; Sasikala, Keshavarao

    2010-08-01

    The focal aim of this study was to assess the frequency of chromosomal aberrations (CA) including chromatid type aberrations (CTA) and chromosomal type aberrations (CSA), micronucleus (MN) and XRCC1 399 Arg/Gln polymorphism in the peripheral blood lymphocytes of 27 petrol pump workers and same number of controls to explore the possible cytogenetic risk on occupational exposure to petrol vapors. The exposed subjects and controls were classified into two groups based on their age (group I < 40 years; group II > 40 years) apart from the classification of the exposed subjects based on their exposure duration (> 8 and < 8 years). CTA and MN frequency were significantly higher in petrol pump workers (p < 0.05) with longer work duration. CTA was found to increase with age in the exposed subjects as well as controls, with exposed subjects showing a statistically higher degree. This effect was not observed in MN. A significantly higher frequency of MN was observed in the smoking petrol pump workers than in control smokers (p < 0.05). No association was found between smoking and CA in both subjects. The study on XRCC1 399 Arg/gln polymorphism in petrol pump workers demonstrated very less difference in allele frequency compared to controls. In conclusion, these datas indicate that petrol pump workers under risk group should be monitored for any long-term adverse effects of the exposure. PMID:20652227

  15. A Cytogenetic Analysis of Chromosomal Region 31 of Drosophila Melanogaster

    PubMed Central

    Clegg, N. J.; Whitehead, I. P.; Brock, J. K.; Sinclair, D. A.; Mottus, R.; Stromotich, G.; Harrington, M. J.; Grigliatti, T. A.

    1993-01-01

    Cytogenetic region 31 of the second chromosome of Drosophila melanogaster was screened for recessive lethal mutations. One hundred and thirty nine new recessive lethal alleles were isolated that fail to complement Df(2L)J2 (31A-32A). These new alleles, combined with preexisting mutations in the region, define 52 complementation groups, 35 of which have not previously been described. Among the new mutations were alleles of the cdc2 and mfs(2)31 genes. Six new deficiencies were also isolated and characterized identifying 16 deficiency subintervals within region 31. The new deficiencies were used to further localize three loci believed to encode non-histone chromosomal proteins. Suvar(2)1/Su(var)214, a dominant suppressor of position-effect variegation (PEV), maps to 31A-B, while the recessive suppressors of PEV mfs(2)31 and wdl were localized to regions 31E and 31F-32A, respectively. In addition, the cytological position of several mutations that interact with heterochromatin were more precisely defined. PMID:8514131

  16. Extensive cytogenetic heterogeneity in a benign retroperitoneal schwannoma.

    PubMed

    Gorunova, L; Dawiskiba, S; Andrén-Sandberg, A; Höglund, M; Johansson, B

    2001-06-01

    A benign retroperitoneal schwannoma from a patient without prior exposure to radiotherapy or chemotherapy was analyzed by chromosome banding after short-term culture. An extensive intratumor heterogeneity in the form of 29 karyotypically related as well as unrelated clones was found. The aberrant clones were diploid or near-diploid and displayed both numerical and structural changes. All chromosomes, except 11, 16, and 20, were affected. Numerical changes included trisomies X, 7, 9, 17, and 18, and monosomies 13 and 18. No clonal loss of chromosome 22, the most characteristic abnormality in schwannomas of other locations, was, however, detected. The structural aberrations resulted in a total of 58 chromosomal breakpoints, with chromosomes 18, 1, and 15 participating in rearrangements most frequently, followed by chromosomes 14, 2, and 22. A striking finding was the clonal involvement of 18p11 in eight rearrangements affecting different chromosomes, suggesting alteration of telomeric function. The molecular mechanisms underlying the observed massive polyclonality in the schwannoma, particularly the presence of cytogenetically unrelated clones, are unknown and probably heterogeneous. PMID:11425455

  17. Molecular cytogenetic characterization of a human thyroid cancercell line

    SciTech Connect

    Weier, Heinz-Ulrich G.; Tuton, Tiffany B.; Ito, Yuko; Chu, LisaW.; Lu, Chung-Mei; Baumgartner, Adolf; Zitzelsberger, Horst F.; Weier,Jingly F.

    2006-01-04

    The incidence of papillary thyroid carcinoma (PTC) increases significantly after exposure of the head and neck region to ionizing radiation, yet we know neither the steps involved in malignant transformation of thyroid epithelium nor the specific carcinogenic mode of action of radiation. Such increased tumor frequency became most evident in children after the 1986 nuclear accident in Chernobyl, Ukraine. In the twelve years following the accident, the average incidence of childhood PTCs (chPTC) increased over one hundred-fold compared to the rate of about 1 tumor incidence per 10{sup 6} children per year prior to 1986. To study the etiology of radiation-induced thyroid cancer, we formed an international consortium to investigate chromosomal changes and altered gene expression in cases of post-Chernobyl chPTC. Our approach is based on karyotyping of primary cultures established from chPTC specimens, establishment of cell lines and studies of genotype-phenotype relationships through high resolution chromosome analysis, DNA/cDNA micro-array studies, and mouse xenografts that test for tumorigenicity. Here, we report the application of fluorescence in situ hybridization (FISH)-based techniques for the molecular cytogenetic characterization of a highly tumorigenic chPTC cell line, S48TK, and its subclones. Using chromosome 9 rearrangements as an example, we describe a new approach termed ''BAC-FISH'' to rapidly delineate chromosomal breakpoints, an important step towards a better understanding of the formation of translocations and their functional consequences.

  18. Lipomatous Change in Uveal Melanoma: Histopathological, Immunohistochemical and Cytogenetic Analysis

    PubMed Central

    Yavuzyigitoglu, Serdar; Kilic, Emine; Vaarwater, Jolanda; de Klein, Annelies; Paridaens, Dion; Verdijk, Robert M.

    2016-01-01

    Purpose The aim of this study was to describe a case of lipomatous change in uveal melanoma. Procedures The patient presented with a 2-year history of blurry vision. A full examination of the right eye revealed a dome-shaped pigmented subretinal mass in the choroid with a thickness of 9 mm and a diameter of 15 mm. The eye was enucleated and prepared for histopathologic, genetic and molecular investigation. Results Histopathology revealed a small circumscribed area consisting of mature adipocytic appearing cells with abundant clear cytoplasm and small peripheral flattened nuclei within a spindle-cell melanoma of the uvea. The cytoplasm of the adipocytic cells stained negative for periodic acid-Schiff and Alcian blue and positive for Melan-A, HMB-45 and tyrosinase, confirming melanocytic lineage. Fluorescence in situ hybridization analysis confirmed trisomy of chromosome 6p22 and disomy of chromosome 3p13 in the nuclei of both the tumor spindle type B cells and in the nuclei of lipomatous tumor cells. Conclusions Lipomatous change can be added to the many histopathologic faces of uveal melanoma. To our knowledge, this is the first report of lipomatous change in uveal melanoma performed with cytogenetic investigations. PMID:27239451

  19. [Cytogenetic analysis of lymphoid blood cells in bovine leucosis].

    PubMed

    Staník, J; Izariková

    1979-11-01

    For the cytogenetic analysis lymphocytes of the peripheral blood were used that had been obtained from cows suffering from leucosis. The blood was taken from a diseased cow, from its 15 months old daughter suffering from leucosis, and from the healthy bull-father (NAT-47). The diagnosis of leucosis was determined by means of hematological examination. In the cow 139 metaphase plates were evaluated, in the daughter 118, and in the bull 132. On the one hand, normoploidy was determined and on the other hand, chromosome aberrations. In the cow 31.0 p. c. of chromosome aberrations were found, in the daughter 32.3 p. c., and in the bull 37.2 p. c. Breaks in X chromosomes were found in the cow (6.7 p. c.) and in the daughter (1.7 p. c.). Longitudinal diversion of arms in the centromere in X chromosomes in the vertical axis into two separate arms was found in the cow amounting to 6.5 p. c., in the daughter to 5.9 p. c., and in the bull to only 0.8 p. c. PMID:117595

  20. Cytogenetic analysis in Rothmund-Thomson syndrome with osteosarcoma

    SciTech Connect

    Amar, M.; Sutphen, R.; Kousseff, B.G.

    1994-09-01

    Rothmund-Thomson syndrome (RTS) is a rare autosomal recessive condition of poikiloderma, erythema, depigmentation, hyperpigmentation, musculoskeletal abnormalities and abnormalities of hair, teeth and nails. Osteogenic sacoma has been reported in 8 patients. Abnormal chromosome studies have been reported in only two patients. Chromosome analysis of tumor or bone marrow has not been reported. We performed cytogenetic studies on a patient with Rothmund-Thomson syndrome and osteogenic sarcoma. Analysis of peripheral lymphocytes revealed 46, XX karyotype by GTW banding. Both spontaneous and chemically-induced chromosome breakage (0.35 and 0.8 breaks/cell) were increased but not significantly different from the age-matched control levels (0.05 and 0.25 breaks/cell). Analysis of mitogen-stimulated bone marrow by Giemsa banding showed slightly increased aneuploidy (20% of cells with random loss of 1 to 5 chromosomes each) and non-specific chromatid despiralization. All 34 cells analyzed from the tumor had normal diploid karyotype, 46.XX. Five of 40 cells derived from skin of the amputated right leg were hyperdiploid with karyotype 47, XX, +7. Skin from the right forearm showed normal karyotype, 46,XX. These results suggest that RTS is associated with chromosomal rearrangement causing acquired somatic mosaicism, including trisomy 7 anomalies. These abnormalities may aid in the diagnosis of RTS and provide clues to the location of the causative gene(s).

  1. Cytogenetic and molecular studies of down syndrome individual with leukemia

    SciTech Connect

    Shen, J.J.; Hassold, T.J.; Williams, B.J.; Zupursky, A.; Doyle, J.; Sherman, S.L.; Jacobs, P.A.; Shugar, A.L.; Soukup, S.W.

    1995-04-01

    There is an increased risk of leukemia in Down syndrome (DS) patients, with estimates ranging from 14 to 30 times the incidence rate observed for chromosomally normal children. Furthermore, one type of leukemia, called {open_quotes}transient leukemia{close_quotes} (TL), occurs almost exclusively in DS infants. The basis of the association between DS and leukemia is unknown, but we and others have hypothesized that it may be influenced by the mechanism of origin of the extra chromosome. Therefore, we initiated a cytogenetic and molecular study of nondisjunction in leukemic DS individuals. To date, we have obtained blood and/or tissue samples from 55 individuals consisting of 17 cases with TL, 7 cases of acute nonlymphocytic leukemia subtype M7 (ANLL-M7, or acute megakaryoblastic leukemia, postulated to be related to TL), and 31 cases of other forms of leukemia. Analysis of these cases suggests differences between DS children with TL and those with other types of leukemia or DS individuals with no history of leukemia. Specifically, the TL and ANLL-M7 cases have a highly significant increase in the frequency of {open_quotes}atypical{close_quotes} constitutional karyotypes (i.e., mosaic trisomies, rings, and/or isochromosomes) and are almost always male. Additionally, genetic mapping studies suggest an increase in the frequency of disomic homozygosity, especially in proximal 21q, in DS individuals with TL and ANLL-M7. 19 refs., 3 figs., 4 tabs.

  2. Molecular cytogenetic analysis of breast cancer cell lines

    PubMed Central

    Davidson, J M; Gorringe, K L; Chin, S-F; Orsetti, B; Besret, C; Courtay-Cahen, C; Roberts, I; Theillet, C; Caldas, C; Edwards, P A W

    2000-01-01

    The extensive chromosome rearrangements of breast carcinomas must contribute to tumour development, but have been largely intractable to classical cytogenetic banding. We report here the analysis by 24-colour karyotyping and comparative genomic hybridization (CGH) of 19 breast carcinoma cell lines and one normal breast epithelial cell line, which provide model examples of karyotype patterns and translocations present in breast carcinomas. The CGH was compared with CGH of 106 primary breast cancers. The lines varied from perfectly diploid to highly aneuploid. Translocations were very varied and over 98% were unbalanced. The most frequent in the carcinomas were 8;11 in five lines; and 8;17, 1;4 and 1;10 in four lines. The most frequently involved chromosome was 8. Several lines showed complex multiply-translocated chromosomes. The very aneuploid karyotypes appeared to fall into two groups that evolved by different routes: one that steadily lost chromosomes and at one point doubled their entire karyotype; and another that steadily gained chromosomes, together with abnormalities. All karyotypes fell within the range seen in fresh material and CGH confirmed that the lines were broadly representative of fresh tumours. The karyotypes provide a resource for the cataloguing and analysis of translocations in these tumours, accessible at http://www.path.cam.ac.uk/~pawefish. © 2000 Cancer Research Campaign PMID:11044355

  3. Cytogenetic toxicity and no-effect limit dose of pesticides.

    PubMed

    Kumar, D; Khan, P K; Sinha, S P

    1995-04-01

    The no-effect limit dose (NELD) of three commonly used pesticides with respect to their cytogenetic toxicity was determined in a number of test systems using a sufficient number of lower doses to characterize the dose-effect relationship. For lindane, malathion and metacid, this dose was 3.2, 7.0 and 3.0 mg/litre, respectively, for mitosis inhibition and 9.0, 55 and 60 mg/litre, respectively, for chromosome clastogeny in onion root-tip cells. For chromosome clastogeny in mice bone marrow cells, the NELDs of the three pesticides were 1.6, 1.5 and 2.0 mg/kg body weight/day, respectively. These values for dominant lethals and X-chromosome-linked recessive lethals in Drosophila were 20 and 5 micrograms lindane/litre, 2 and 3.5 micrograms malathion/litre and 4 and 5.5 micrograms metacid/litre, respectively. Thus, the NELDs are not only pesticide specific but also organism specific, tissue specific and even damage specific. Furthermore, the NELD values determined are so small that the real human exposure to pesticides cannot be reduced below these levels without compromising the effectiveness of pesticides in use. PMID:7537710

  4. Comparative Cytogenetics of the Congo African Grey Parrot (Psittacus erithacus).

    PubMed

    Seibold-Torres, Cassandra; Owens, Elaine; Chowdhary, Renuka; Ferguson-Smith, Malcolm A; Tizard, Ian; Raudsepp, Terje

    2015-01-01

    The Congo African grey parrot (Psittacus erithacus, PER) is an endemic species of Central Africa, valued for its intelligence and listed as vulnerable due to poaching and habitat destruction. Improved knowledge about the P. erithacus genome is needed to address key biological questions and conservation of this species. The P. erithacus genome was studied using conventional and molecular cytogenetic approaches including Zoo-FISH. P. erithacus has a 'typical' parrot karyotype with 2n = 62-64 and 8 pairs of macrochromosomes. A distinct feature was a sharp macro-microchromosome boundary. Telomeric sequences were present at all chromosome ends and interstitially in PER2q, the latter coinciding with a C-band. NORs mapped to 4 pairs of microchromosomes which is in contrast to a single NOR in ancestral type avian karyotypes. Zoo-FISH with chicken macrochromosomes GGA1-9 and Z revealed patterns of conserved synteny similar to many other avian groups, though neighboring synteny combinations of GGA6/7, 8/9, and 1/4 were distinctive only to parrots. Overall, P. erithacus shared more Zoo-FISH patterns with neotropical macaws than Australian species such as cockatiel and budgerigar. The observations suggest that Psittaciformes karyotypes have undergone more extensive evolutionary rearrangements compared to the majority of other avian genomes. PMID:26894300

  5. Hyperspectral backscatter imaging: a label-free approach to cytogenetics.

    PubMed

    Rebner, Karsten; Ostertag, Edwin; Kessler, Rudolf W

    2016-08-01

    Current techniques for chromosome analysis need to be improved for rapid, economical identification of complex chromosomal defects by sensitive and selective visualisation. In this paper, we present a straightforward method for characterising unstained human metaphase chromosomes. Backscatter imaging in a dark-field setup combined with visible and short near-infrared spectroscopy is used to monitor morphological differences in the distribution of the chromosomal fine structure in human metaphase chromosomes. The reasons for the scattering centres in the fine structure are explained. Changes in the scattering centres during preparation of the metaphases are discussed. FDTD simulations are presented to substantiate the experimental findings. We show that local scattering features consisting of underlying spectral modulations of higher frequencies associated with a high variety of densely packed chromatin can be represented by their scatter profiles even on a sub-microscopic level. The result is independent of the chromosome preparation and structure size. This analytical method constitutes a rapid, cost-effective and label-free cytogenetic technique which can be used in a standard light microscope. Graphical abstract Hyperspectral backscatter imaging for label-free characterization. PMID:27277813

  6. Cytogenetic damages in peripheral blood of monkey lymphocytes under simulation of cosmonauts irradiation.

    NASA Astrophysics Data System (ADS)

    Petrov, Vladislav; Ivanov, Alexandr; Barteneva, Svetlana; Snigiryeva, Galina; Shafirkin, Alexandr

    Earth modeling of crewmember exposure should be performed for correct estimating radiation hazard during the flight. Such modeling was planned in a monkey experiment for investigating consequences of exposure to a man during an interplanetary flight. It should reflect a chronic impact of galactic cosmic rays and acute and fractional irradiation specified for solar cosmic rays and radiation belts respectively. Due to the difficulty of modeling a chronic impact with the help of a charged particles accelerator it can be used the gamma source. While irradiating big animal groups during a long-term period of time it is preferably to replace chronic irradiation by an equal fractional one. In this case the chosen characteristics of fractional irradiation should ensure the appearances of radiobiological consequences equal to the ones caused by the modeled chronic exposure. So for developing an exposure scheme in the monkey experiment (with Macaca -Rhesus) the model of the acting residual dose, that takes into account repair and recovery processes in the exposed body was used. The total dose value was in the limits from 2.32 Gy up to 3.5 Gy depending on the exposure character. The acting residual dose in all versions of exposure was 2.0 Gy for every monkey. While performing the experiment all the requirements of bioethics for the work with animals were observed. The objects of interest were genomic damages in lymphocytes of monkey's peripheral blood. The data about the CAF during the exposure and at various time moments after exposure particularly directly after the completion of chronicle and fractional irradiation were analyzed. CAF -dose of acute single gamma-irradiation in the range 0 -1.5Gy relationship (calibration curve) was defined in vitro. In addition the rate of the aberrant cells elimination within three months after the irradiation completion was estimated. On the basis of the obtained CAF data we performed verification of applicability of cytogenetic analysis

  7. Bone fracture repair - series (image)

    MedlinePlus

    ... main treatment options for bone fractures are: Casting Open reduction, and internal fixation- this involves a surgery to repair the fracture-frequently, metal rods, screws or plates are used to repair the bone, and remain ...

  8. Electric motor model repair specifications

    SciTech Connect

    1995-08-01

    These model repair specifications list the minimum requirements for repair and overhaul of polyphase AC squireel cage induction motors. All power ranges, voltages, and speeds of squirrel cage motors are covered.

  9. Getting Ready To Repair.

    ERIC Educational Resources Information Center

    Stryker, Rick

    2002-01-01

    Successful camp repairs require careful planning. Prioritize projects by program needs first, then by cost. Determine the cause of deterioration and address it. Build goodwill with suppliers by knowing what you want and giving them ample time to prepare estimates. Include labor costs, even for staff labor. A cost-estimate table for a sample…

  10. Comprehensive Small Engine Repair.

    ERIC Educational Resources Information Center

    Hires, Bill; And Others

    This curriculum guide contains the basic information needed to repair all two- and four-stroke cycle engines. The curriculum covers four areas, each consisting of one or more units of instruction that include performance objectives, suggested activities for teacher and students, information sheets, assignment sheets, job sheets, visual aids,…

  11. Repairing cracked glass

    NASA Technical Reports Server (NTRS)

    Helman, D. D.; Holt, J. W.; Smiser, L. V.

    1979-01-01

    Filing procedure consisting of machined lightweight fused-silica tiles coated with thin-layer of borosilicate glass produces homogeneous seal in thin glass. Procedure is useful in repairing glass envelopes, X-ray tub windows, Dewar flasks, and similar thin glass objects.

  12. Automotive Body Repair Competencies.

    ERIC Educational Resources Information Center

    D'Armond, Jack; And Others

    Designed to provide a model curriculum and guidelines, this manual presents tasks that were identified by employers, employees, and teachers as important in a postsecondary auto body repair curriculum. The tasks are divided into ten major component areas of instruction: metalworking and fiberglass, painting, frame and suspension, glass and trim,…

  13. Patent urachus repair

    MedlinePlus

    ... Drugs & Supplements Videos & Tools About MedlinePlus Show Search Search MedlinePlus GO GO About MedlinePlus Site Map FAQs Contact Us Health Topics Drugs & Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Patent urachus repair URL of this page: //medlineplus.gov/ ...

  14. Patent urachus repair - slideshow

    MedlinePlus

    ... Drugs & Supplements Videos & Tools About MedlinePlus Show Search Search MedlinePlus GO GO About MedlinePlus Site Map FAQs Contact Us Health Topics Drugs & Supplements Videos & Tools Español You Are Here: Home → Medical Encyclopedia → Patent urachus repair - series—Normal anatomy URL of this ...

  15. Repairing damaged platforms

    SciTech Connect

    Moore, R.E.; Kwok, P.H.; Wang, S.S.

    1995-10-01

    This paper introduces a unique method for strengthening of platforms and replacing damaged members. Extending the life of existing infrastructure is approved means of decreasing cash expenditures for new platforms and facilities. Platforms can be affected by corrosion, overloading and fatigue. The renovation and repair of existing offshore installations is an important part of offshore engineering. The basis behind this paper is an April, 1993 incident in the Arabian Gulf. A vessel broke loose from its moorings in a severe storm and collided with a wellhead platform. The collision severely damaged the platform buckling seven major support members and cracking joints throughout the structure. In view of the significant damage, there was an urgent need to repair the structure to avoid any further damage from potentially sever winter storm conditions. Various means of repair and their associated costs were evaluated: traditional dry hyperbaric welding, adjacent platforms, grouted clamped connections, and mechanical pipe connectors. The repair was completed using an innovative combination of clamps and wet welding to attach external braces to the structure.

  16. Proteoglycans and brain repair.

    PubMed

    Properzi, Francesca; Fawcett, James W

    2004-02-01

    Proteoglycans are complex molecules composed of long, unbranched sugar chains attached to a protein core. In the mammalian central nervous system, they are a major component of the extracellular matrix and of the cellular surface. After a central nervous system injury, their expression in the lesion area changes strongly and contributes to the inhibition of axon regrowth and brain repair. PMID:14739401

  17. Targeting Nuclear Envelope Repair.

    PubMed

    2016-06-01

    Migrating cancer cells undergo repeated rupture of the protective nuclear envelope as they squeeze through small spaces in the surrounding tissue, compromising genomic integrity. Inhibiting both general DNA repair and the mechanism that seals these tears may enhance cell death and curb metastasis. PMID:27130435

  18. Auto Repair Gets Technical.

    ERIC Educational Resources Information Center

    Steiger, Jim; Shoemaker, Byrl

    1989-01-01

    Rapid advances in automotive technology and the growth of the automotive service industry have created opportunities in car repair, parts supply, and body work. Certification is the best way for vocational educators to ensure that their programs prepare students for work in the automotive industry. (JOW)

  19. Aircraft Propeller Hub Repair

    SciTech Connect

    Muth, Thomas R.; Peter, William H.

    2015-02-13

    The team performed a literature review, conducted residual stress measurements, performed failure analysis, and demonstrated a solid state additive manufacturing repair technique on samples removed from a scrapped propeller hub. The team evaluated multiple options for hub repair that included existing metal buildup technologies that the Federal Aviation Administration (FAA) has already embraced, such as cold spray, high velocity oxy-fuel deposition (HVOF), and plasma spray. In addition the team helped Piedmont Propulsion Systems, LLC (PPS) evaluate three potential solutions that could be deployed at different stages in the life cycle of aluminum alloy hubs, in addition to the conventional spray coating method for repair. For new hubs, a machining practice to prevent fretting with the steel drive shaft was recommended. For hubs that were refurbished with some material remaining above the minimal material condition (MMC), a silver interface applied by an electromagnetic pulse additive manufacturing method was recommended. For hubs that were at or below the MMC, a solid state additive manufacturing technique using ultrasonic welding (UW) of thin layers of 7075 aluminum to the hub interface was recommended. A cladding demonstration using the UW technique achieved mechanical bonding of the layers showing promise as a viable repair method.

  20. Achilles tendon repair

    MedlinePlus

    ... ency/article/007643.htm Achilles tendon repair To use the sharing features on this page, please enable JavaScript. Your Achilles tendon joins your calf muscle to your heel. You can tear your Achilles tendon if you land hard on your heel during sports, from a ...

  1. Basic Book Repair Methods.

    ERIC Educational Resources Information Center

    Schechter, Abraham A.

    This book addresses some common preservation techniques that invariably become necessary in library and archival collections of any size. The procedures are described in chronological sequence, and photographs show the techniques from the viewpoint of the person actually doing the work. The recommended repair methods can be accomplished using…

  2. Femoral hernia repair

    MedlinePlus

    ... bulges out of a weak spot in the groin. Usually this tissue is part of the intestine. ... Your surgeon makes a cut (incision) in your groin area. The hernia is ... wall. This repairs the weakness in the wall. At the end ...

  3. Single cell wound repair

    PubMed Central

    Abreu-Blanco, Maria Teresa; Verboon, Jeffrey M

    2011-01-01

    Cell wounding is a common event in the life of many cell types, and the capacity of the cell to repair day-to-day wear-and-tear injuries, as well as traumatic ones, is fundamental for maintaining tissue integrity. Cell wounding is most frequent in tissues exposed to high levels of stress. Survival of such plasma membrane disruptions requires rapid resealing to prevent the loss of cytosolic components, to block Ca2+ influx and to avoid cell death. In addition to patching the torn membrane, plasma membrane and cortical cytoskeleton remodeling are required to restore cell function. Although a general understanding of the cell wound repair process is in place, the underlying mechanisms of each step of this response are not yet known. We have developed a model to study single cell wound repair using the early Drosophila embryo. Our system combines genetics and live imaging tools, allowing us to dissect in vivo the dynamics of the single cell wound response. We have shown that cell wound repair in Drosophila requires the coordinated activities of plasma membrane and cytoskeleton components. Furthermore, we identified an unexpected role for E-cadherin as a link between the contractile actomyosin ring and the newly formed plasma membrane plug. PMID:21922041

  4. Comparative cytogenetics of ten species of cichlid fishes (Teleostei, Cichlidae) from the Araguaia River system, Brazil, by conventional cytogenetic methods

    PubMed Central

    Valente, G. Targino; Vitorino, C. de Andrade; Cabral-de-Mello, D.C.; Oliveira, C.; Souza, I. Lima; Martins, C.; Venere, P.C.

    2012-01-01

    Abstract Cichlids represent one of the most species-rich families of fishes and have attracted the attention of evolutionary biologists due to the rapid radiation occurring in some groups and the importance of some species in the world aquaculture. Cytogenetic analysis was conducted in 10 cichlid species from the Araguaia River, Amazon Basin, Brazil. The chromosome number was 2n=48 for all analyzed species except for Laetacara araguaiae Ottoni et Costa, 2009 (2n=44). Chromosomal polymorphism was detected only in Geophagus proximus (Castelnau, 1855), which exhibits an extra large submetacentric and and a dot-like chromosomes. Moreover, the C-banding revealed a general pericentromeric heterochromatic pattern and some additional blocks for some species. The heterochromatic blocks corresponding to AgNOR bearing regions were observed in all species and also corresponded to CMA3 positive blocks, which were observed in terminal regions. Besides the general conserved chromosomal and heterochromatin patterns for South American cichlids, the presence of GC-rich heterochromatin was quite different in the species Biotodoma cupido (Heckel, 1840), Geophagus proximus, Retroculus lapidifer (Castelnau, 1855), Crenicichla strigata Günther, 1862 and Heros efasciatus Heckel, 1840. The results suggest that independent events of heterochromatin modification occurred during chromosome evolution in the group, regardless of the conservation of macro-chromosomal structure. PMID:24260660

  5. Impact of Imatinib Adherence on the Cytogenetic Response in Pediatric Chronic Myeloid Leukemia - Chronic Phase.

    PubMed

    Ganta, Ranga Raman; Nasaka, Srividya; Gundeti, Sadashivudu

    2016-09-01

    The authors aimed to study the impact of adherence to imatinib during initial 6 mo on the cytogenetic response in pediatric chronic myeloid leukemia - chronic phase (CML CP). The hospital records of pediatric CML patients (age ≤18 y) from 2009 through 2012, were analyzed retrospectively for the drug adherence and cytogenetic response (CyR) at 6 mo. Forty eight children were analyzed, with the median age of 13 y (range 5-18) and slight male preponderance (M:F- 1.18:1). Sokal scores were low, intermediate and high in 14 (29.3 %), 26 (54.1 %), 8 (16.6 %) children respectively. Only a little more than half of the children were adherent (58 %). At the end of 6 mo, complete cytogenetic response (CCyR) was achieved by 78.5 % of adherent children as compared to 5 % of non-adherent children. Majority (80 %) of the non-adherent children had only a partial cytogenetic response (PCyR). Therefore, it is concluded that most of the adherent children had optimal cytogenetic response at the end of 6 mo and majority of those in the non-adherent group did not attain it. PMID:26843266

  6. Cytogenetic studies of 1232 patients with different sexual development abnormalities from the Sultanate of Oman.

    PubMed

    Al-Alawi, Intisar; Goud, Tadakal Mallana; Al-Harasi, Salma; Rajab, Anna

    2016-02-01

    The aim of this study was to evaluate cytogenetic findings in Omani patients who had been referred for suspicion of sex chromosome abnormalities that resulted in different clinical disorders. Furthermore, it sought to examine the frequency of chromosomal anomalies in these patients and to compare the obtained results with those reported elsewhere. Cytogenetic analysis was performed on 1232 cases with variant characteristics of sexual development disorders who had been referred to the cytogenetic department, National Genetic Centre, Ministry of Health, from different hospitals in the Sultanate of Oman between 1999 and 2014. The karyotype results demonstrated chromosomal anomalies in 24.2% of the cases, where 67.5% of abnormalities were identified in referral females, whereas only 32.6% were in referral males. Of all sex chromosome anomalies detected, Turner syndrome was the most frequent (38.2%) followed by Klinefelter syndrome (24.9%) and XY phenotypic females (16%). XXX syndrome and XX phenotypic males represented 6.8% and 3.8% of all sex chromosome anomalies, respectively. Cytogenetic analysis of patients referred with various clinical suspicions of chromosomal abnormalities revealed a high rate of chromosomal anomalies. This is the first broad cytogenetic study reporting combined frequencies of sex chromosome anomalies in sex development disorders in Oman. PMID:26706459

  7. Banding cytogenetic analysis in pediatric patients with acute lymphoblastic leukemia (ALL) in a Brazilian population

    PubMed Central

    2013-01-01

    Background Cytogenetic studies in Brazilian population about childhood acute lymphoblastic leukemia (ALL), the most common childhood malignancy, are scarce. Moreover, Brazilian race is very heterogeneous and is made by the confluence of people of several different origins, from the original Native Brazilians, with the influx of Portuguese colonizers, Black African slaves, and recent European, Arab and Japanese immigration. The purpose of this prospective, multicentric study was to assess the sociodemographic, clinic and cytogenetic characteristics of the children treated for ALL in the Northeast region of Brazil. Results This study includes thirty patients between 4 months and 17 years old treated for ALL from January 1st, 2009 to November 30th, 2010. Cytogenetic analysis showed that in nineteen out of thirty patients (64%) presented some chromosome abnormalities, in which 53% corresponds to numerical abnormalities, 21% structural and numerical abnormalities, and 26% only structural changes. Moreover, seven patients presented complexes karyotype not yet described in the literature. Taken together these results show the importance of the cytogenetic analysis in ALL pediatric patients and illustrates that the studied population presented unexpected complexes karyotypes which were correlated to poor outcome. Conclusion The results demonstrate the importance of banding cytogenetics for ALL diagnosis despite the use of most modern techniques such as FISH and aCGH, and provide reliable insight into the ALL in Brazil. PMID:24025689

  8. Electron Transfer Mechanisms of DNA Repair by Photolyase

    NASA Astrophysics Data System (ADS)

    Zhong, Dongping

    2015-04-01

    Photolyase is a flavin photoenzyme that repairs two DNA base damage products induced by ultraviolet (UV) light: cyclobutane pyrimidine dimers and 6-4 photoproducts. With femtosecond spectroscopy and site-directed mutagenesis, investigators have recently made significant advances in our understanding of UV-damaged DNA repair, and the entire enzymatic dynamics can now be mapped out in real time. For dimer repair, six elementary steps have been characterized, including three electron transfer reactions and two bond-breaking processes, and their reaction times have been determined. A unique electron-tunneling pathway was identified, and the critical residues in modulating the repair function at the active site were determined. The dynamic synergy between the elementary reactions for maintaining high repair efficiency was elucidated, and the biological nature of the flavin active state was uncovered. For 6-4 photoproduct repair, a proton-coupled electron transfer repair mechanism has been revealed. The elucidation of electron transfer mechanisms and two repair photocycles is significant and provides a molecular basis for future practical applications, such as in rational drug design for curing skin cancer.

  9. Lawn and Garden Equipment Repair.

    ERIC Educational Resources Information Center

    Hardway, Jack; And Others

    This publication is designed to supplement the Comprehensive Small Engine Rapair guide by covering in detail all aspects of lawn and garden equipment repair not included in general engine repair or the repair of other small engines. It consists of instructional materials for both teachers and students, written in terms of student performance using…

  10. Cleft lip repair - series (image)

    MedlinePlus

    ... in the middle of the upper lip. A cleft palate is an opening in the roof of the ... Cleft lip repair and cleft palate repair are indicated for: Repair of physical deformity Nursing, feeding, or speech problems resulting from cleft lip or palate

  11. Automotive Engine Maintenance and Repair.

    ERIC Educational Resources Information Center

    Marine Corps Inst., Washington, DC.

    This correspondence course, originally developed for the Marine Corps, is designed to provide students with an understanding of automotive engine maintenance and repair. The course contains six study units covering automotive engine maintenance and repair; design classification; engine malfunction, diagnosis, and repair; engine disassembly; engine…

  12. Dynamics and mechanisms of DNA repair by photolyase

    PubMed Central

    Liu, Zheyun; Wang, Lijuan; Zhong, Dongping

    2015-01-01

    Photolyase, a class of flavoproteins, uses blue light to repair two types of ultraviolet-induced DNA damage, cyclobutane pyrimidine dimer (CPD) and pyrimidine-pyrimidone (6–4) photoproduct (6–4PP). In this perspective, we review the recent progress on the repair dynamics and mechanisms of both types of DNA restoration by photolyases. We first report the spectroscopic characterization of flavin in various redox states and the active-site solvation dynamics in photolyases. We then systematically summarize the detailed repair dynamics of damaged DNA by photolyases and a biomimetic system through resolving all elementary steps on the ultrafast timescales, including multiple intermolecular electron- and proton-transfer reactions and bond-breaking and -making processes. We determined the unique electron tunneling pathways, identified the key functional residues and revealed the molecular origin of high repair efficiency, and thus elucidate the molecular mechanisms and repair photocycles at the most fundamental level. We finally conclude that the active sites of photolyases, unlike aqueous solution for the biomimetic system, provide a unique electrostatic environment and local flexibility and thus a dedicated synergy for all elementary dynamics to maximize the repair efficiency. This repair photomachine is the first enzyme that the entire functional evolution is completely mapped out in real time. PMID:25870862

  13. Association Between the Cytogenetic Profile of Tumor Cells and Response to Preoperative Radiochemotherapy in Locally Advanced Rectal Cancer

    PubMed Central

    González-González, María; Garcia, Jacinto; Alcazar, José A.; Gutiérrez, María L.; Gónzalez, Luis M.; Bengoechea, Oscar; Abad, María M.; Santos-Briz, Angel; Blanco, Oscar; Martín, Manuela; Rodríguez, Ana; Fuentes, Manuel; Muñoz-Bellvis, Luis; Orfao, Alberto; Sayagues, Jose M.

    2014-01-01

    Abstract Neoadjuvant radiochemotherapy to locally advanced rectal carcinoma patients has proven efficient in a high percentage of cases. Despite this, some patients show nonresponse or even disease progression. Recent studies suggest that different genetic alterations may be associated with sensitivity versus resistance of rectal cancer tumor cells to neoadjuvant therapy. We investigated the relationship between intratumoral pathways of clonal evolution as assessed by interphase fluorescence in situ hybridization (51 different probes) and response to neoadjuvant radiochemotherapy, evaluated by Dworak criteria in 45 rectal cancer tumors before (n = 45) and after (n = 31) treatment. Losses of chromosomes 1p (44%), 8p (53%), 17p (47%), and 18q (38%) and gains of 1q (49%) and 13q (75%) as well as amplification of 8q (38%) and 20q (47%) chromosomal regions were those specific alterations found at higher frequencies. Significant association (P < 0.05) was found between alteration of 1p, 1q, 11p, 12p, and 17p chromosomal regions and degree of response to neoadjuvant therapy. A clear association was observed between cytogenetic profile of the ancestral tumor cell clone and response to radiochemotherapy; cases presenting with del(17p) showed a poor response to neoadjuvant treatment (P = 0.03), whereas presence of del(1p) was more frequently observed in responder patients (P = 0.0002). Moreover, a significantly higher number of copies of chromosomes 8q (P = 0.004), 13q (P = 0.003), and 20q (P = 0.002) were found after therapy versus paired pretreatment rectal cancer samples. Our results point out the existence of an association between tumor cytogenetics and response to neoadjuvant therapy in locally advanced rectal cancer. Further studies in larger series of patients are necessary to confirm our results. PMID:25474426

  14. Association between the cytogenetic profile of tumor cells and response to preoperative radiochemotherapy in locally advanced rectal cancer.

    PubMed

    González-González, María; Garcia, Jacinto; Alcazar, José A; Gutiérrez, María L; Gónzalez, Luis M; Bengoechea, Oscar; Abad, María M; Santos-Briz, Angel; Blanco, Oscar; Martín, Manuela; Rodríguez, Ana; Fuentes, Manuel; Muñoz-Bellvis, Luis; Orfao, Alberto; Sayagues, Jose M

    2014-11-01

    Neoadjuvant radiochemotherapy to locally advanced rectal carcinoma patients has proven efficient in a high percentage of cases. Despite this, some patients show nonresponse or even disease progression. Recent studies suggest that different genetic alterations may be associated with sensitivity versus resistance of rectal cancer tumor cells to neoadjuvant therapy. We investigated the relationship between intratumoral pathways of clonal evolution as assessed by interphase fluorescence in situ hybridization (51 different probes) and response to neoadjuvant radiochemotherapy, evaluated by Dworak criteria in 45 rectal cancer tumors before (n = 45) and after (n = 31) treatment. Losses of chromosomes 1p (44%), 8p (53%), 17p (47%), and 18q (38%) and gains of 1q (49%) and 13q (75%) as well as amplification of 8q (38%) and 20q (47%) chromosomal regions were those specific alterations found at higher frequencies. Significant association (P < 0.05) was found between alteration of 1p, 1q, 11p, 12p, and 17p chromosomal regions and degree of response to neoadjuvant therapy. A clear association was observed between cytogenetic profile of the ancestral tumor cell clone and response to radiochemotherapy; cases presenting with del(17p) showed a poor response to neoadjuvant treatment (P = 0.03), whereas presence of del(1p) was more frequently observed in responder patients (P = 0.0002). Moreover, a significantly higher number of copies of chromosomes 8q (P = 0.004), 13q (P = 0.003), and 20q (P = 0.002) were found after therapy versus paired pretreatment rectal cancer samples. Our results point out the existence of an association between tumor cytogenetics and response to neoadjuvant therapy in locally advanced rectal cancer. Further studies in larger series of patients are necessary to confirm our results. PMID:25474426

  15. Development, genetic and cytogenetic analyses of genetic sexing strains of the Mexican fruit fly, Anastrepha ludens Loew (Diptera: Tephritidae)

    PubMed Central

    2014-01-01

    Background Anastrepha ludens is among the pests that have a major impact on México's economy because it attacks fruits as citrus and mangoes. The Mexican Federal government uses integrated pest management to control A. ludens through the Programa Nacional Moscas de la Fruta [National Fruit Fly Program, SAGARPA-SENASICA]. One of the main components of this program is the sterile insect technique (SIT), which is used to control field populations of the pest by releasing sterile flies. Results To increase the efficiency of this technique, we have developed a genetic sexing strain (GSS) in which the sexing mechanism is based on a pupal colour dimorphism (brown-black) and is the result of a reciprocal translocation between the Y chromosome and the autosome bearing the black pupae (bp) locus. Ten strains producing wild-type (brown pupae) males and mutant (black pupae) females were isolated. Subsequent evaluations for several generations were performed in most of these strains. The translocation strain named Tapachula-7 showed minimal effect on survival and the best genetic stability of all ten strains. Genetic and cytogenetic analyses were performed using mitotic and polytene chromosomes and we succeeded to characterize the chromosomal structure of this reciprocal translocation and map the autosome breakpoint, despite the fact that the Y chromosome is not visible in polytene nuclei following standard staining. Conclusions We show that mitotic and polytene chromosomes can be used in cytogenetic analyses towards the development of genetic control methods in this pest species. The present work is the first report of the construction of GSS of Anastrepha ludens, with potential use in a future Moscafrut operational program. PMID:25472896

  16. DNA repair activity in fish and interest in ecotoxicology: a review.

    PubMed

    Kienzler, Aude; Bony, Sylvie; Devaux, Alain

    2013-06-15

    The knowledge of DNA repair in a target species is of first importance as it is the primary line of defense against genotoxicants, and a better knowledge of DNA repair capacity in fish could help to interpret genotoxicity data and/or assist in the choice of target species, developmental stage and tissues to focus on, both for environmental biomonitoring studies and DNA repair testing. This review focuses in a first part on what is presently known on a mechanistic basis, about the various DNA repair systems in fish, in vivo and in established cell lines. Data on base excision repair (BER), direct reversal with O⁶-alkylguanine transferase and double strand breaks repair, although rather scarce, are being reviewed, as well as nucleotide excision repair (NER) and photoreactivation repair (PER), which are by far the most studied repair mechanisms in fish. Most of these repair mechanisms seem to be strongly species and tissue dependent; they also depend on the developmental stage of the organisms. BER is efficient in vivo, although no data has been found on in vitro models. NER activity is quite low or even inexistent depending on the studies; however this lack is partly compensated by a strong PER activity, especially in early developmental stage. In a second part, a survey of the ecotoxicological studies integrating DNA repair as a parameter responding to single or mixture of contaminant is realized. Three main approaches are being used: the measurement of DNA repair gene expression after exposure, although it has not yet been clearly established whether gene expression is indicative of repair capacity; the monitoring of DNA damage removal by following DNA repair kinetics; and the modulation of DNA repair activity following exposure in situ, in order to assess the impact of exposure history on DNA repair capacity. Since all DNA repair processes are possible targets for environmental pollutants, we can also wonder at which extent such a modulation of repair capacities

  17. High resolution comparative genomic hybridisation in clinical cytogenetics

    PubMed Central

    Kirchhoff, M.; Rose, H.; Lundsteen, C.

    2001-01-01

    High resolution comparative genomic hybridisation (HR-CGH) is a diagnostic tool in our clinical cytogenetics laboratory. The present survey reports the results of 253 clinical cases in which 47 abnormalities were detected. Among 144 dysmorphic and mentally retarded subjects with a normal conventional karyotype, 15 (10%) had small deletions or duplications, of which 11 were interstitial. In addition, a case of mosaic trisomy 9 was detected. Among 25 dysmorphic and mentally retarded subjects carrying apparently balanced de novo translocations, four had deletions at translocation breakpoints and two had deletions elsewhere in the genome. Seventeen of 19 complex rearrangements were clarified by HR-CGH. A small supernumerary marker chromosome occurring with low frequency and the breakpoint of a mosaic r(18) case could not be clarified. Three of 19 other abnormalities could not be confirmed by HR-CGH. One was a Williams syndrome deletion and two were DiGeorge syndrome deletions, which were apparently below the resolution of HR-CGH. However, we were able to confirm Angelman and Prader-Willi syndrome deletions, which are about 3-5 Mb. We conclude that HR-CGH should be used for the evaluation of (1) dysmorphic and mentally retarded subjects where normal karyotyping has failed to show abnormalities, (2) dysmorphic and mentally retarded subjects carrying apparently balanced de novo translocations, (3) apparently balanced de novo translocations detected prenatally, and (4) for clarification of complex structural rearrangements.


Keywords: comparative genomic hybridisation; chromosome analysis; chromosome aberrations; dysmorphism PMID:11694545

  18. Comparative cytogenetics between the species Passiflora edulis and Passiflora cacaoensis.

    PubMed

    Viana, A J C; Souza, M M

    2012-09-01

    Passiflora edulis Sims is the most economically important species of the genus Passiflora. A new species was described recently, Passiflora cacaoensis Bernacci & Souza, which displayed morphologic characteristics very similar to P. edulis. Due to the need for delimitation of the two species, karyomorphological and banding analyses were carried out. Both species have 2n = 18, with the same karyotype formula 16 m + 2sm. There was variation between the species regarding the location of satellites and the width of chromosome pairs 2, 4 and 8. C banding revealed the presence of constitutive heterochromatin in the centromeric and telomeric regions of all chromosomes in both species. However, only in P. cacaoensis did chromosomes 3 and 9 have a large quantity of heterochromatin. Fluorochrome banding revealed CMA(+) bands only in the satellites, but no DAPI(+) bands. Fluorescence in situ hybridisation (FISH) showed that in P. cacaoensis the rDNA 5S probe is located in a single site in the subterminal position of the long arm of chromosome 5. However, for the rDNA 45S probe, two sites were detected in terminal positions of the long arms of chromosome 7, with a bigger and stronger signal, and of chromosome 9. According to the asymmetry index and the quantity of heterochromatin, P. cacaoensis is a more basal species than P. edulis. The cytogenetic data indicate that P. cacaoensis is closely related to P. edulis, but is a different species. PMID:22404746

  19. Cytogenetic analysis of the pathology of frozen shoulder

    PubMed Central

    Kabbabe, Benjamin; Ramkumar, Satish; Richardson, Martin

    2010-01-01

    Background: Frozen shoulder (FS) is a debilitating musculoskeletal condition with an uncertain etiology and pathogenic mechanism. The aim of this study was to investigate the hypothesis that an alteration in the level of cytokines may disrupt the normal inflammatory and tissue healing process in the shoulder, leading to the development of FS. Materials and Methods: A prospective case–control study was undertaken, analyzing patients undergoing arthroscopic treatment of FS and control patients being treated for subacromial bursitis. Synovial biopsies were taken from all subjects. Synovial RNA levels were analyzed using quantitative polymerase chain reaction (qPCR) Results: Thirteen patients with FS were recruited, four of whom were diagnosed with diabetes mellitus, along with 10 control patients. Cytogenetic analysis using qPCR revealed both fibrogenic cytokine matrix metalloproteinase 3 (MMP 3) (1.98×10 5 vs. 755.0, P=0.068) and inflammatory cytokine interleukin 6 (IL 6) (1679.2 vs. 372.8, P=0.062) to be elevated in FS cases as compared to controls. Comparison between diabetic and non-diabetic patients revealed a decrease in the level of expression of inflammatory cytokine, monocyte colony stimulating factor (M-CSF) (12,496 vs. 305.1, P=0.04) in diabetic FS patients. Conclusions: The results demonstrate that levels of inflammatory and fibrogenic cytokines are elevated in the synovium of patients with FS compared with controls. This indicates that altered levels of inflammatory cytokines may be associated with the pathogenesis of inflammation evolving into fibrosis, which is the characteristic feature of FS. We have also shown the opposite to be the case in patients with diabetic FS. PMID:21472067

  20. Cytogenetic telomere and telomerase studies in lumbo-sacral chordoma

    SciTech Connect

    Schwartz, H.S.; Dahir, G.A.; Miller, L.K.

    1994-09-01

    Lumbo-sacral chordomas are rare skeletal sarcomas that originate from the remnant notochord. There are approximately 35 lumbo-sacral chordomas reported annually in the U.S.A. The understanding of this rare human cancer is limited to observations of its clinical behavior and embryonic link. We performed chromosome and molecular analyses from five surgically harvested chordomas in an effort to document genetic abnormalities and to further understand its tumor biology. Cytogenetically, four of five patients had entirely normal chromosomes. One patient had several abnormalities seen in one of 100 cells including a translocation with breakpoints at bands 5q13 and 7q22, loss of one X chromosome and an extra chromosome 14. There was no evidence of monosomy X or trisomy 14 seen with interphase in situ hybridization using biotin-labeled alpha satellite chromosome specific probes for chromosome 14/22 and X. Telomere integrity is required to protect termini from illegitimate recombination. Typically telomeric reduction occurs in senescent fibroblasts in vivo aging and several human solid tumors. A telomeric probe (TTAGGG){sub 50} was hybridized to genomic DNA isolated from chordoma cells and digested with Hinf I which allows the telomeric DNA to remain intact. The tumor DNA was paired with leukocyte DNA from age-matched controls and revealed telomere elongation in all four patients studied with molecular genetic techniques. Telomerase activity is required to maintain telomere integrity and is not present in normal somatic cells. It is determined by visualizing the sizes of the electrophoresis gel-separated radioactive telomeric fragments assembled during incubation of cytoplasmic extracts containing telomerase. Telomerase activity was detected when compared with HeLa cells, a positive control. In addition, no telomerase activity was detected from the chordoma patient`s fibroblasts.

  1. Malignant granular cell tumor of the lateral femoral cutaneous nerve: report of a case with cytogenetic analysis.

    PubMed

    Di Tommaso, Luca; Magrini, Elisabetta; Consales, Alessandro; Poppi, Massimo; Pasquinelli, Gianandrea; Dorji, Tsering; Benedetti, Giovanni; Baccarini, Paola

    2002-12-01

    Malignant granular cell tumors (MGCTs) are rare neoplasms of uncertain histogenesis. We report a case of MGCT involving a peripheral nerve with peritoneal and omental dissemination in which cytogenetic findings are available. Our results show that MGCTs share some cytogenetic abnormalities with malignant peripheral nerve sheath tumors (MPNSTs), supporting the hypothesis that they may represent histogenetically related lesions. PMID:12514794

  2. Base Excision Repair and Cancer

    PubMed Central

    Wallace, Susan S.; Murphy, Drew L.; Sweasy, Joann B.

    2012-01-01

    Base excision repair is the system used from bacteria to man to remove the tens of thousands of endogenous DNA damages produced daily in each human cell. Base excision repair is required for normal mammalian development and defects have been associated with neurological disorders and cancer. In this paper we provide an overview of short patch base excision repair in humans and summarize current knowledge of defects in base excision repair in mouse models and functional studies on short patch base excision repair germ line polymorphisms and their relationship to cancer. The biallelic germ line mutations that result in MUTYH-associated colon cancer are also discussed. PMID:22252118

  3. Cytogenetic and molecular genetic demonstration of polyclonality in an acinic cell carcinoma.

    PubMed Central

    Jin, C.; Jin, Y.; Höglund, M.; Wennerberg, J.; Akervall, J.; Willén, R.; Dictor, M.; Mandahl, N.; Mitelman, F.; Mertens, F.

    1998-01-01

    The paradigm that human malignancies are monoclonal has been questioned during recent years by the finding of unrelated, cytogenetically aberrant clones in short-term cultures from certain tumour types, notably carcinomas of the breast, skin and upper aerodigestive tract. In order to analyse whether cytogenetically unrelated clones are also unrelated at the molecular level, we analysed the X-chromosome inactivation status in cell cultures from a cytogenetically highly polyclonal acinic cell carcinoma of the parotid gland. By using cell cultures dominated by a single abnormal clone, obtained through in vitro culturing for 3-5 passages, we showed that the different clones must indeed have originated from different cells. Images Figure 2 PMID:9703273

  4. ST1571 (imatinib mesylate) reduces bone marrow cellularity and normalizes morphologic features irrespective of cytogenetic response.

    PubMed

    Hasserjian, Robert P; Boecklin, Federica; Parker, Sally; Chase, Andy; Dhar, Sunanda; Zaiac, Michael; Olavarria, Eduardo; Lampert, Irvin; Henry, Kristin; Apperley, Jane F; Goldman, John M

    2002-03-01

    The tyrosine kinase inhibitor STI571 (imatinib mesylate, Gleevec) is an effective treatment for chronic myeloid leukemia (CML). We examined bone marrow samples from 53 patients with CML who were receiving STI571 in 3 multicenter phase 2 trials to assess morphologic changes and cytogenetic response to this drug. In most patients with initially increased blasts, the bone marrow blast count rapidly decreased during STI571 therapy. Reductions in cellularity, the myeloid/erythroid ratio (commonly with relative erythroid hyperplasia), and reticulin fibrosis (if present pretreatment) also were seen in most patients, resulting in an appearance resembling normal marrow in many cases. Eighteen patients (34%) had some degree of cytogenetic response. Surprisingly, these striking morphologic changes occurred irrespective of any cytogenetic response to STI571. Thus, STI571 seems to affect the differentiation of CML cells in vivo, causing even extensively Philadelphia chromosome-positive hematopoiesis to exhibitfeatures resembling normal hematopoiesis. PMID:11888075

  5. Minimally Invasive Spigelian Hernia Repair

    PubMed Central

    Baucom, Catherine; Nguyen, Quan D.; Hidalgo, Marco

    2009-01-01

    Introduction: Spigelian hernia is an uncommon ventral hernia characterized by a defect in the linea semilunaris. Repair of spigelian hernia has traditionally been accomplished via an open transverse incision and primary repair. The purpose of this article is to present 2 case reports of incarcerated spigelian hernia that were successfully repaired laparoscopically using Gortex mesh and to present a review of the literature regarding laparoscopic repair of spigelian hernias. Methods: Retrospective chart review and Medline literature search. Results: Two patients underwent laparoscopic mesh repair of incarcerated spigelian hernias. Both were started on a regular diet on postoperative day 1 and discharged on postoperative days 2 and 3. One patient developed a seroma that resolved without intervention. There was complete resolution of preoperative symptoms at the 12-month follow-up. Conclusion: Minimally invasive repair of spigelian hernias is an alternative to the traditional open surgical technique. Further studies are needed to directly compare the open and the laparoscopic repair. PMID:19660230

  6. Gene Therapy for Cartilage Repair

    PubMed Central

    Madry, Henning; Orth, Patrick; Cucchiarini, Magali

    2011-01-01

    The concept of using gene transfer strategies for cartilage repair originates from the idea of transferring genes encoding therapeutic factors into the repair tissue, resulting in a temporarily and spatially defined delivery of therapeutic molecules to sites of cartilage damage. This review focuses on the potential benefits of using gene therapy approaches for the repair of articular cartilage and meniscal fibrocartilage, including articular cartilage defects resulting from acute trauma, osteochondritis dissecans, osteonecrosis, and osteoarthritis. Possible applications for meniscal repair comprise meniscal lesions, meniscal sutures, and meniscal transplantation. Recent studies in both small and large animal models have demonstrated the applicability of gene-based approaches for cartilage repair. Chondrogenic pathways were stimulated in the repair tissue and in osteoarthritic cartilage using genes for polypeptide growth factors and transcription factors. Although encouraging data have been generated, a successful translation of gene therapy for cartilage repair will require an ongoing combined effort of orthopedic surgeons and of basic scientists. PMID:26069580

  7. Prognostic impact of persistent cytogenetic abnormalities at complete remission in adult patients with acute lymphoblastic leukemia.

    PubMed

    Short, Nicholas J; Kantarjian, Hagop M; Jabbour, Elias J; O'Brien, Susan M; Faderl, Stefan; Burger, Jan A; Garris, Rebecca; Qiao, Wei; Huang, Xuelin; Jain, Nitin; Konopleva, Marina; Kadia, Tapan M; Daver, Naval; Borthakur, Gautam; Cortes, Jorge E; Ravandi, Farhad

    2016-06-01

    In acute myelogenous leukemia, the persistent detection of abnormal cytogenetics at complete remission (ACCR) is associated with inferior outcomes. However, the prognostic significance of ACCR in adult patients with acute lymphoblastic leukemia (ALL) is unknown. We evaluated 272 adult patients with ALL and abnormal cytogenetics at baseline who were treated with frontline induction chemotherapy, achieved complete remission (CR) and had cytogenetic analysis performed at the time of CR. ACCR was observed in 26 patients (9.6%). Median relapse-free survival was 22 months (95% CI, 12 months to not reached) for patients with ACCR vs. 48 months (range, 30-125 months) in patients with normal cytogenetics at CR (NCCR; P = 0.31). Median overall survival also did not differ significantly between the ACCR (99 months [range, 17 months to not reached]) and NCCR groups (67 months [range, 47 months to not reached], P = 0.86). The specificity of ACCR for minimal residual disease (MRD) positivity by multi-parameter flow cytometry (MFC) was 43%, and there was overall poor correlation between these two methods for the detection of residual disease. When patients were stratified by MRD status, the presence or absence of persistent cytogenetic abnormalities at CR did not add additional prognostic information. This study suggests that there is poor association between MRD assessment by MFC and the presence or absence of cytogenetic abnormalities at CR in adult patients with ALL. ACCR was not associated with adverse outcomes in ALL and did not add additional prognostic information when MRD status by MFC was known. PMID:26800008

  8. Cytogenetic studies of Brazilian pediatric myelodysplastic syndrome cases: challenges and difficulties in a large and emerging country

    PubMed Central

    Velloso, E.D.R.P.; Chauffaille, M.L.; Peliçario, L.M.; Tanizawa, R.S.S.; Toledo, S.R.C.; Gaiolla, R.D.; Lopes, L.F.

    2013-01-01

    Myelodysplastic syndromes (MDS) and juvenile myelomonocytic leukemia (JMML) are rare hematopoietic stem cell diseases affecting children. Cytogenetics plays an important role in the diagnosis of these diseases. We report here the experience of the Cytogenetic Subcommittee of the Brazilian Cooperative Group on Pediatric Myelodysplastic Syndromes (BCG-MDS-PED). We analyzed 168 cytogenetic studies performed in 23 different cytogenetic centers; 84 of these studies were performed in patients with confirmed MDS (primary MDS, secondary MDS, JMML, and acute myeloid leukemia/MDS+Down syndrome). Clonal abnormalities were found in 36.9% of the MDS cases and cytogenetic studies were important for the detection of constitutional diseases and for differential diagnosis with other myeloid neoplasms. These data show the importance of the Cooperative Group for continuing education in order to avoid a late or wrong diagnosis. PMID:23314345

  9. Prokaryotic nucleotide excision repair.

    PubMed

    Kisker, Caroline; Kuper, Jochen; Van Houten, Bennett

    2013-03-01

    Nucleotide excision repair (NER) has allowed bacteria to flourish in many different niches around the globe that inflict harsh environmental damage to their genetic material. NER is remarkable because of its diverse substrate repertoire, which differs greatly in chemical composition and structure. Recent advances in structural biology and single-molecule studies have given great insight into the structure and function of NER components. This ensemble of proteins orchestrates faithful removal of toxic DNA lesions through a multistep process. The damaged nucleotide is recognized by dynamic probing of the DNA structure that is then verified and marked for dual incisions followed by excision of the damage and surrounding nucleotides. The opposite DNA strand serves as a template for repair, which is completed after resynthesis and ligation. PMID:23457260

  10. Cytogenetic abnormality in patients with multiple myeloma analyzed by fluorescent in situ hybridization

    PubMed Central

    Hu, Ying; Chen, Wenming; Chen, Shilun; Huang, Zhongxia

    2016-01-01

    Objective To analyze the fluorescent in situ hybridization (FISH) data and the association with clinical characteristics, therapy response, and survival time in patients with multiple myeloma. Method We performed a retrospective review of patients with multiple myeloma from November 2010 to April 2014. Results Cytogenetic abnormalities by FISH were detectable in 66% of patients. One cytogenetic abnormality, two cytogenetic abnormalities, and complex abnormalities were detectable in 21.2%, 51.5%, and 27.3% of cases, respectively. 1q21 amplification, t(4p16.3/14q32), and 17p deletion were observed in 69.7%, 30.3%, and 21.2% of cases, respectively. Total response rates (complete response [CR] + near CR + partial response) were 93.8% and 82.1%, respectively, in cytogenetic normality group and abnormality group. CR rates were 50% and 32.1%, respectively. Median overall survival (OS) time was 51 months and 24 months, respectively, in cytogenetic normality group and abnormality group (P<0.05). Median OS time was not significantly different between 1q21 amplification group and no 1q21 amplification group in patients with FISH abnormalities (P>0.05). Median OS time was not significantly different between t(4;14) group and no t(4;14) group in patients with FISH abnormalities (P>0.05). Seven patients of 17p deletion died in 2 years. Conclusion Multiple myeloma is characterized by a high occurrence of chromosomal aberrations. 1q21 amplification and t(4;14) are the most common abnormalities. Multiple cytogenetic abnormalities are frequently observed in the same one patient. The total response rate, CR rate, and OS time are worse in cytogenetic abnormal patients compared with cytogenetic normal patients. Patients with 17p deletion have a very poor prognosis. Future goals of therapy will be to achieve minimal residual disease, biomarkers, and genomic data, which might provide a better estimate of the depth of response to therapy and OS. PMID:27042105

  11. Cytogenetic analysis in a large series of children with non-syndromic mental retardation

    PubMed Central

    Bouhjar, Inesse Ben Abdallah; Gmidène, Abir; Mougou-Zrelli, Soumaya; Hannachi, Hanene; Soyah, Najla; Gadour, Naoufel; Harrabi, Imed; Elghezal, Hatem; Saad, Ali

    2012-01-01

    Mental retardation affects 1–3% of the population. To evaluate the implication of chromosomal abnormalities in the etiology of mental retardation, 1420 patients with non-syndromic mental retardation recruited at the department of cytogenetics of Farhat Hached hospital (Sousse, Tunisia) between January 2005 and December 2009, were analyzed using standard cytogenetic techniques. Age ranged between 3 and 18 years with a median of 8 years. Chromosomal abnormalities were detected in 7.8% of patients and an increased prevalence of chromosome anomalies was observed in patients when the mental retardation is associated with a severe degree of intellectual disability, facial dysmorphic features and/or congenital malformations or epilepsy.

  12. [Non-radioactive in situ hybridization of alpha-satellite sequences in cytogenetic diagnosis].

    PubMed

    Perfumo, C; Arslanian, A; Zara, F; Piombo, G; Pierluigi, M

    1992-01-01

    Non isotopic in situ hybridization with alpha-satellite DNA probes in the cytogenetic diagnosis. Standard banding cytogenetic techniques do not always allow to define the structure and the origin of chromosome rearrangements involving the centromere region. Non-isotopic in situ hybridization of alphoid sequences has allowed to determine the origin of the centromeres in the metaphases of 5 patients referred to us for: 2 structural rearrangements involving chromosome 21, 2 structural rearrangements involving chromosome Y and 1 reciprocal translocation involving on chromosome 20 and one chromosome 15. PMID:1465321

  13. Cytogenetic response of Scots pine (Pinus sylvestris Linnaeus, 1753) (Pinaceae) to heavy metals

    PubMed Central

    Belousov, Mikhail Vladimirovich; Mashkina, Olga Sergeyevna; Popov, Vasily Nikolayevich

    2012-01-01

    Abstract We studied cytogenetic reactions of Scots pine seedlings to heavy metals – lead, cupric and zinc nitrates applied at concentrations 0.5 to 2000 µM. We determined the range of concentrations of heavy metals that causes mutagenic effect. Lead was found to cause the strongest genotoxicity as manifested by significant increase in the frequency of pathological mitosis, occurrence of fragmentations and agglutinations of chromosomes, various types of bridges, and a significant number of the micronuclei which were absent in the control. Possible cytogenetic mechanisms of the cytotoxic action of heavy metals are discussed. PMID:24260654

  14. Proteoglycans and cartilage repair.

    PubMed

    Ouzzine, Mohamed; Venkatesan, Narayanan; Fournel-Gigleux, Sylvie

    2012-01-01

    Repair of damaged articular cartilage in osteoarthritis (OA) is a clinical challenge. Because cartilage is an avascular and aneural tissue, normal mechanisms of tissue repair through recruitment of cells to the site of tissue destruction are not feasible. Proteoglycan (PG) depletion induced by the proinflammatory cytokine interleukin-1β, a principal mediator in OA, is a major factor in the onset and progression of joint destruction. Current symptomatic treatments of OA by anti-inflammatory drugs do not alter the progression of the disease. Various therapeutic strategies have been developed to antagonize the effect of proinflammatory cytokines. However, relatively few studies were conducted to stimulate anabolic activity, in an attempt to enhance cartilage repair. To this aim, a nonviral gene transfer strategy of glycosyltransferases responsible for PG synthesis has been developed and tested for its capacity to promote cartilage PG synthesis and deposition. Transfection of chondrocytes or cartilage explants by the expression vector for the glycosyltransferase β-1,3-glucuronosyltransferase-I (GlcAT-I) enhanced PG synthesis and deposition in the ECM by promoting the synthesis of chondroitin sulfate GAG chains of the cartilage matrix. This indicates that therapy mediated through GT gene delivery may constitute a new strategy for the treatment of OA. PMID:22252645

  15. Non-homologous end joining repair in Xenopus egg extract

    PubMed Central

    Zhu, Songli; Peng, Aimin

    2016-01-01

    Non-homologous end joining (NHEJ) is a major DNA double-strand break (DSB) repair mechanism. We characterized here a series of plasmid-based DSB templates that were repaired in Xenopus egg extracts via the canonical, Ku-dependent NHEJ pathway. We showed that the template with compatible ends was efficiently repaired without end processing, in a manner that required the kinase activity of DNA-PKcs but not ATM. Moreover, non-compatible ends with blunt/3′-overhang, blunt/5′-overhang, and 3′-overhang/5′-overhang were predominantly repaired with fill-in and ligation without the removal of end nucleotides. In contrast, 3′-overhang/3′-overhang and 5′-overhang/5′-overhang templates were processed by resection of 3–5 bases and fill-in of 1–4 bases prior to end ligation. Therefore, the NHEJ machinery exhibited a strong preference for precise repair; the presence of neither non-compatible ends nor protruding single strand DNA sufficiently warranted the action of nucleases. ATM was required for the efficient repair of all non-compatible ends including those repaired without end processing by nucleases, suggesting its role beyond phosphorylation and regulation of Artemis. Finally, dephosphorylation of the 5′-overhang/3′-overhang template reduced the efficiency of DNA repair without increasing the risk of end resection, indicating that end protection via prompt end ligation is not the sole mechanism that suppresses the action of nucleases. PMID:27324260

  16. Cytogenetic and molecular cytogenetic findings in 43 aneurysmal bone cysts: aberrations of 17p mapped to 17p13.2 by fluorescence in situ hybridization.

    PubMed

    Althof, Pamela A; Ohmori, Kazuo; Zhou, Ming; Bailey, Jacqueline M; Bridge, R Stuart; Nelson, Marilu; Neff, James R; Bridge, Julia A

    2004-05-01

    Aneurysmal bone cyst is a benign, cystic lesion of bone composed of blood-filled spaces separated by fibrous septa. Relatively few cases of aneurysmal bone cyst have been cytogenetically characterized, yet abnormalities of the short arm of chromosome 17 appear to be recurrent. In this study, conventional cytogenetic analysis of 43 aneurysmal bone cyst specimens from 38 patients over a 12-year period revealed clonal chromosomal abnormalities in 12 specimens. Karyotypic anomalies of 17p, including a complex translocation and inversion, were identified in eight of these 12 specimens. In an effort to further define the aberrant 17p breakpoint, fluorescence in situ hybridization (FISH) analyses were performed using a series of probe combinations spanning a 5.1 Mb region between the TP53 (17p13.1) and Miller-Dieker lissencephaly syndrome (17p13.3) gene loci. These studies revealed the critical breakpoint locus at 17p13.2, flanked proximally by an RP11-46I8, RP11-333E1, and RP11-457I18 bacterial artificial chromosome (BAC) probe cocktail and distally by an RP11-198F11 and RP11-115H24 BAC and RP5-1050D4 P1 artificial chromosome (PAC) probe cocktail. Overall, abnormalities of the 17p13.2 locus were identified by metaphase and/or interphase cell FISH analysis in 22 of 35 (63%) aneurysmal bone cyst specimens examined including 26 karyotypically normal specimens. These cytogenetic and molecular cytogenetic findings expand our knowledge of chromosomal alterations in aneurysmal bone cyst, further localize the critically involved 17p breakpoint, and provide an alternative approach (ie FISH) for detecting 17p abnormalities in nondividing cells of aneurysmal bone cysts. The latter could potentially be utilized as an adjunct in diagnostically challenging cases. PMID:15044915

  17. Targeting base excision repair for chemosensitization.

    PubMed

    Adhikari, Sanjay; Choudhury, Sujata; Mitra, Partha S; Dubash, Jerita J; Sajankila, Shyama P; Roy, Rabindra

    2008-05-01

    In both bacteria and eukaryotes the alkylated, oxidized, and deaminated bases and depurinated lesions are primarily repaired via an endogenous preventive pathway, i.e. base excision repair (BER). Radiation therapy and chemotherapy are two important modes of cancer treatment. Many of those therapeutic agents used in the clinic have the ability to induce the DNA damage; however, they may also be highly cytotoxic, causing peripheral toxicity and secondary cancer as adverse side effects. In addition, the damage produced by the therapeutic agents can often be repaired by the BER proteins, which in effect confers therapeutic resistance. Efficient inhibition of a particular BER protein(s) may increase the efficacy of current chemotherapeutic regimes, which minimizes resistance and ultimately decreases the possibility of the aforementioned negative side effects. Therefore, pharmacological inhibition of DNA damage repair pathways may be explored as a useful strategy to enhance chemosensitivity. Various agents have shown excellent results in preclinical studies in combination chemotherapy. Early phase clinical trials are now being carried out using DNA repair inhibitors targeting enzymes such as PARP, DNA-PK or MGMT. In the case of BER proteins, elimination of N-Methylpurine DNA glycosylase (MPG) or inhibition of AP-endonuclease (APE) increased sensitivity of cancer cells to alkylating chemotherapeutics. MPG(-/-) embryonic stem cells and cells having MPG knock-down by siRNA are hypersensitive to alkylating agents, whereas inhibition of APE by small molecule inhibitors sensitized cancer cells to alkylating chemotherapeutics. Thus, MPG and other BER proteins could be potential targets for chemosensitization. PMID:18473720

  18. Clinical, cytogenetic and molecular-cytogenetic characterization of a patient with a de novo tandem proximal-intermediate duplication of 16q and review of the literature.

    PubMed

    Lonardo, Fortunato; Perone, Lucia; Maioli, Marianna; Ciavarella, Maria; Ciccone, Roberto; Monica, Matteo Della; Lombardi, Cinzia; Forino, Luisa; Cantalupo, Giuseppina; Masella, Lucia; Scarano, Francesca

    2011-04-01

    Partial trisomy 16 is rare and most of the reported cases are secondary to chromosome rearrangements resulting in concurrent monosomies or trisomies of a second chromosome. Only a few patients survive the neonatal period and the duplication of the long arm seems to be mainly responsible for the prenatal lethality of the full trisomy 16. The reported patients with a partial 16q trisomy have a wide spectrum of congenital anomalies that include dysmorphic features, central nervous system malformations, failure to thrive, and club feet. The patients with duplications of proximal 16q frequently have short stature, developmental delay, speech delay, learning difficulties, and mild to severe behavioral problems. Here we describe a patient with an inverted de novo tandem duplication of 16q with breakpoints evaluated in detail by molecular-cytogenetic techniques. Main clinical features include postural, motor and speech delay with severe learning difficulties and behavioral problems, obesity, microcephaly, and mild dysmorphic features. In the report we attempt to classify the few reported patients with pure partial duplications of 16q in more narrow and homogeneous groups: proximal, proximal-intermediate, intermediate, and intermediate-distal duplications. Moreover, we emphasize the importance of proper cytogenetic investigation and complete molecular cytogenetic refinement in all cases with a suspected chromosomal anomaly. PMID:21416588

  19. Heterogenous mismatch-repair status in colorectal cancer

    PubMed Central

    2014-01-01

    Abstract Background Immunohistochemical staining for mismatch repair proteins is efficient and widely used to identify mismatch repair defective tumors. The tumors typically show uniform and widespread loss of MMR protein staining. We identified and characterized colorectal cancers with alternative, heterogenous mismatch repair protein staining in order to delineate expression patterns and underlying mechanisms. Methods Heterogenous staining patterns that affected at least one of the mismatch repair proteins MLH1, PMS2, MSH2 and MSH6 were identified in 14 colorectal cancers. Based on alternative expression patterns macro-dissected and micro-dissected tumor areas were separately analyzed for microsatellite instability and MLH1 promoter methylation. Results Heterogenous retained/lost mismatch repair protein expression could be classified as intraglandular (within or in-between glandular formations), clonal (in whole glands or groups of glands) and compartmental (in larger tumor areas/compartments or in between different tumor blocks). These patterns coexisted in 9/14 tumors and in the majority of the tumors correlated with differences in microsatellite instability/MLH1 methylation status. Conclusions Heterogenous mismatch repair status can be demonstrated in colorectal cancer. Though rare, attention to this phenomenon is recommended since it corresponds to differences in mismatch repair status that are relevant for correct classification. Virtual Slides The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1771940323126788 PMID:24968821

  20. Cytogenetic profiles of 2806 patients with acute myeloid leukemia-a retrospective multicenter nationwide study.

    PubMed

    Byun, Ja Min; Kim, Young Jin; Yoon, Hwi-Joong; Kim, Si-Young; Kim, Hee-Je; Yoon, Jaeho; Min, Yoo Hong; Cheong, Jun-Won; Park, Jinny; Lee, Jae Hoon; Hong, Dae Sik; Park, Seong Kyu; Kim, Hyeoung-Joon; Ahn, Jae-Sook; Shin, Ho-Jin; Chung, Joo Seop; Lee, Won Sik; Lee, Sang Min; Park, Yong; Kim, Byung Soo; Lee, Je-Hwan; Lee, Kyoo-Hyung; Jung, Chul Won; Jang, Jun Ho; Min, Woo-Sung; Park, Tae Sung

    2016-08-01

    The cytogenetic and molecular data is recognized as the most valuable prognostic factor in acute myeloid leukemia (AML). Our aim was to systemically analyze the cytogenetics of Korean AML patients and to compare the cytogenetic profiles of various races to identify possible geographic heterogeneity. We retrospectively reviewed medical records of 2806 AML patients diagnosed at 11 tertiary teaching hospitals in Korea between January 2007 and December 2011. The most common recurrent chromosomal abnormality was t(8;21) (8.8 %, 238/2717), but t(15;17) showed an almost same number (8.6 %,235/2717). Among de novo AML, the most frequent aberrations were t(15;17), observed in 229 (10.7 %). The most common French-American-British (FAB) classification type was M2 (32.2 %), and recurrent cytogenetic abnormalities correlated with the FAB subtypes. Among 283 secondary AML cases, myelodysplastic syndrome was the most common predisposing factor. About 67.1 % of the secondary AML cases were associated with chromosomal aberrations, and chromosome 7 abnormalities (n = 45, 15.9 %) were most common. The incidence of FLT3 internal tandem duplication mutation was relatively low at 15 %. Our study reports certain similarities and differences in comparison to previous reports. Such discrepancies call for extensive epidemiological studies to clarify the role of genetic as well as geographic heterogeneity in the pathogenesis of AML. PMID:27230620

  1. Inferring Diversity and Evolution in Fish by Means of Integrative Molecular Cytogenetics

    PubMed Central

    Artoni, Roberto Ferreira; Castro, Jonathan Pena; Jacobina, Uedson Pereira; Lima-Filho, Paulo Augusto; Félix da Costa, Gideão Wagner Werneck; Molina, Wagner Franco

    2015-01-01

    Fish constitute a paraphyletic and profusely diversified group that has historically puzzled ichthyologists. Hard efforts are necessary to better understand this group, due to its extensive diversity. New species are often identified and it leads to questions about their phylogenetic aspects. Cytogenetics is becoming an important biodiversity-detection tool also used to measure biodiversity evolutionary aspects. Molecular cytogenetics by fluorescence in situ hybridization (FISH) allowed integrating quantitative and qualitative data from DNA sequences and their physical location in chromosomes and genomes. Although there is no intention on presenting a broader review, the current study presents some evidences on the need of integrating molecular cytogenetic data to other evolutionary biology tools to more precisely infer cryptic species detection, population structuring in marine environments, intra- and interspecific karyoevolutionary aspects of freshwater groups, evolutionary dynamics of marine fish chromosomes, and the origin and differentiation of sexual and B chromosomes. The new cytogenetic field, called cytogenomics, is spreading due to its capacity to give resolute answers to countless questions that cannot be answered by traditional methodologies. Indeed, the association between chromosomal markers and DNA sequencing as well as between biological diversity analysis methodologies and phylogenetics triggers the will to search for answers about fish evolutionary, taxonomic, and structural features. PMID:26345638

  2. Autotetraploid Pacific oysters (Crassostrea gigas) obtained using normal diploid eggs: induction and impact on cytogenetic stability.

    PubMed

    Benabdelmouna, Abdellah; Ledu, Christophe

    2015-07-01

    We describe two methods of producing viable and fertile autotetraploid Pacific oyster (Crassostrea gigas Thunberg) based on the use of normal-sized oocytes produced by normal diploid females. Our methods showed that the oocyte size is not a limiting factor for the success of the induction to autotetraploidy. These methods offer means of direct introgression of genetic progress from elite diploid lines to tetraploids used as broodstock, avoiding a triploid step with the risk of transferring undesirable traits from highly fecund triploids. High variability in the level of cytogenetic stability was found among the different tetraploid oysters tested, showing that induction method has an important impact on the long-term cytogenetic stability of the tetraploids. It appears that induction method based on the use of triploid females induces a greater cytogenetic instability among tetraploids so obtained, and this compared to tetraploids originating from the two methods described in our present study. As the aneuploidies and reversions observed in tetraploids can have serious consequences for the sustainability of tetraploid broodstock itself, as well as their triploid offspring, the two tetraploid induction methods described in the present work offer means to produce tetraploids with optimal cytogenetic, genetic, and zootechnical performances. PMID:26230146

  3. Burden of cytogenetically abnormal plasma cells in light chain amyloidosis and their prognostic relevance.

    PubMed

    Kim, Seon Young; Im, Kyongok; Park, Si Nae; Kim, Jung-Ah; Yoon, Sung-Soo; Lee, Dong Soon

    2016-05-01

    We performed cytoplasmic fluorescence in situ hybridization assays of light chain amyloidosis (AL). In total, 234 patients were enrolled: 28 patients with AL, 24 with monoclonal gammopathy of undetermined significance (MGUS), and 182 with multiple myeloma (MM). Chromosomal abnormalities were detected in 13 of 22 (59%) AL patients without MM. All 13 patients demonstrated IGH rearrangement, and t(11;14)/IGH-CCND1 was most frequent (32%). Chromosome gain was not observed in AL patients without MM. These findings were dissimilar to findings in MGUS patients, in whom trisomy 9 was the most frequent abnormality. Of 6 AL patients with MM, 5 (83%) patients had cytogenetic abnormalities: 1q gain (4/6, 67%), gains of chromosome 9 (3/6, 50%), IGH rearrangement and RB1 (13q) deletions (2/6 each, 33%). The percentage of clonal plasma cells among total plasma cells was variable (median, 75%; range, 16-100%) for AL patients without MM, which was lower than the results for MM patients (median 100%). The overall survival of AL patients without MM was not significantly different according to the presence of cytogenetic abnormalities (P=0.510). In summary, among Korean AL patients, IGH rearrangement was the most frequent cytogenetic abnormality and cytogenetic aberration patterns differ compared with MGUS and MM patients. PMID:27015231

  4. CYTOGENETIC STUDIES IN MICE TREATED WITH THE JET FUELS, JET-A AND JP-8

    EPA Science Inventory

    Cytogenetic studies in mice treated with the jet fuels, Jet-A and JP-8
    Abstract
    The genotoxic potential of the jet fuels, Jet-A and JP-8, were examined in mice treated on the skin with a single dose of 240 ug/mouse. Peripheral blood smears were prepared at the start of the ...

  5. The results of selective cytogenetic monitoring of Chernobyl accident victims in the Ukraine

    SciTech Connect

    Pilinskaya, M.A.

    1996-07-01

    Selective cytogenetic monitoring of the highest priority groups of Chernobyl disaster victims has been carried out since 1987. In 1992-1993, 125 liquidators (irradiated mainly in 1986) and 42 persons recovering from acute radiation sickness of the second and third degrees of severity were examined. Cytogenetic effects (an elevated level of unstable as well as stable markers of radiation exposure) were found in all groups, which showed a positive correlation with the initial degree of irradiation severity even 6-7 y after the accident. Comparative scoring of conventional staining vs. G-banding in 10 liquidators showed the identical rate of unstable aberrations. At the same time, the yield of stable aberrations for G-banded slides exceeded the frequency for conventional staining. In order to study possible mutagenic activity of chronic low levels of irradiation, the cytogenetic monitoring of some critical groups of the population (especially children and occupational groups-tractor drivers and foresters) living in areas of the Ukraine contaminated by radionuclides was carried out. In all the examined groups, a significant increase in the frequency of aberrant metaphases, chromosome aberrations (both unstable and stable), an chromatid aberrations was observed. Data gathered from groups of children reflect the intensity of mutagenic impact on the studied populations and demonstrate a positive correlation with the duration of exposure. Results of cytogenetic examination of adults confirmed the importance of considering the contribution of occupational radiation exposure to genetic effects of Chernobyl accident factors on the population of contaminated areas. 17 refs., 3 tabs.

  6. Cytogenetics of monosomes in Zea mays. Comprehensive report, February 1, 1977-May 15, 1980

    SciTech Connect

    Weber, D. F.

    1980-02-01

    Progress is reported in research on the cytogenetics of maize. The study has identified genetic factors that control the meiotic process, genetic recombination, lipid biosynthesis, and the free amino acid pool. It has also been determined that distributive pairing, gene compensation, and gene magnification do not occur in maize. (ACR)

  7. Xp11.2 Translocation Renal Cell Carcinoma Diagnosed by Immunohistochemistry and Cytogenetics

    PubMed Central

    Dey, Biswajit; Badhe, Bhawana; Govindarajan, Krishna Kumar; Ramesh, Ranjith Arumbakkam

    2016-01-01

    Xp11.2 translocation renal cell carcinomas (TRCCs) are a group of neoplasms with distinct clinical, histopathological appearance, immunohistochemical, and cytogenetic profile. We report a case of Xp11.2 translocation TRCC in an 11-year-old male diagnosed based on immunohistochemistry and fluorescence in situ hybridization. PMID:27365924

  8. Cytogenetic Survey for Autistic Fragile X Carriers in a Mental Retardation Center.

    ERIC Educational Resources Information Center

    Cantu, Eduardo S.; And Others

    1990-01-01

    The cytogenetic survey of 67 individuals previously identified as having mental retardation and autistic behaviors revealed only 1.5 percent with the fragile X chromosome. The finding suggests that most persons with fragile X syndrome do not have autistic behaviors severe enough to be identified as a secondary psychiatric diagnosis. (Author/DB)

  9. [Studies of the repair of radiation-induced genetic damage in Drosophila]. Annual progress report, October 1, 1988--June 1, 1989

    SciTech Connect

    1989-12-31

    The primary goal of this study is to achieve a more thorough understanding of the mechanisms employed by higher organisms to repair DNA damage induced by both ionizing and nonionizing radiation. These studies are also contributing to an improved understanding of the processes of mutagenesis and carcinogenesis in higher eukaryotes. The studies employ Drosophila as a model organism for investigating repair functions that are common to all higher eukaryotes. Drosophila was chosen in the early phases of this study primarily because of the ease with which one can isolate and characterize repair-deficient mutants in a metazoan organism. The laboratory has gone on to investigate the metabolic defects of such mutants while others have performed complementary genetic and cytogenetic studies which relate DNA repair processes to mutagenesis and chromosome stability. The repair studies have exploited the capacity to introduce mutant Drosophila cells into tissue culture and thereby compare repair defects directly with those of homologous human disorders. Researchers are currently employing recombinant DNA technology to investigate the mechanisms of the DNA repair pathways defined by those mutants.

  10. The repair of sub-lethal damage and the stimulated repair of potentially lethal damage in Saintpaulia.

    PubMed

    Leenhouts, H P; Sijsma, M J; Litwiniszyn, M; Chadwick, K H

    1981-10-01

    The repair of sublethal and potentially lethal damage in stationary resting epidermal cells of Saintpaulia has been investigated. Fractionation experiments reveal an efficient repair of sublethal damage with a half-life of 1.9 hours. No repair of potentially lethal damage was noted when cultivation of the leaves was delayed for 24 hours after irradiation. At delay times of 2, 3 and 4 days some repair of potentially lethal damage has been found. A small pre-dose given 24 hours before a challenging dose improved the cells' chance to regenerate and the improvement has been shown to be compatible with an improved repair of potentially lethal damage induced by X-rays and fast neutrons. It hs been shown that the stimulated repair process takes 12 to 24 hours to develop, is dependent on the size of the pre-dose, has single-hit dose kinetics, and an r.b.e. of 1 for neutrons. With delayed cultivation of 2 days the stimulated repair process leads to an alteration in the shape of the regeneration (survival)-dose relationship which increases the low dose r.b.e. for neutrons from 10 to 35. PMID:6975252

  11. Intraoral repair of cosmetic restorations.

    PubMed

    Denehy, G; Bouschlicher, M; Vargas, M

    1998-10-01

    The longevity of porcelain and composite resin restorations can often be prolonged by using sound principles, up-to-date materials, and judicious attention to repair when fracture problems arise. Careful case selection and correct usage of surface treatment agents, followed by the use of a quality bonding system and restorative materials, can result in a repair that exhibits excellent retention and natural color blending. This article outlines procedures and materials to repair both resin composite and porcelain intraorally. PMID:9891653

  12. Minimal residual disease evaluation by flow cytometry is a complementary tool to cytogenetics for treatment decisions in acute myeloid leukaemia.

    PubMed

    Vidriales, María-Belén; Pérez-López, Estefanía; Pegenaute, Carlota; Castellanos, Marta; Pérez, José-Juan; Chandía, Mauricio; Díaz-Mediavilla, Joaquín; Rayón, Consuelo; de Las Heras, Natalia; Fernández-Abellán, Pascual; Cabezudo, Miguel; de Coca, Alfonso García; Alonso, Jose M; Olivier, Carmen; Hernández-Rivas, Jesús M; Montesinos, Pau; Fernández, Rosa; García-Suárez, Julio; García, Magdalena; Sayas, María-José; Paiva, Bruno; González, Marcos; Orfao, Alberto; San Miguel, Jesús F

    2016-01-01

    The clinical utility of minimal residual disease (MRD) analysis in acute myeloid leukaemia (AML) is not yet defined. We analysed the prognostic impact of MRD level at complete remision after induction therapy using multiparameter flow cytometry in 306 non-APL AML patients. First, we validated the prognostic value of MRD-thresholds we have previously proposed (≥ 0.1%; ≥ 0.01-0.1%; and <0.01), with a 5-year RFS of 38%, 50% and 71%, respectively (p=0.002). Cytogenetics is the most relevant prognosis factor in AML, however intermediate risk cytogenetics represent a grey zone that require other biomarkers for risk stratification, and we show that MRD evaluation discriminate three prognostic subgroups (p=0.03). Also, MRD assessments yielded relevant information on favourable and adverse cytogenetics, since patients with favourable cytogenetics and high MRD levels have poor prognosis and patients with adverse cytogenetics but undetectable MRD overcomes the adverse prognosis. Interestingly, in patients with intermediate or high MRD levels, intensification with transplant improved the outcome as compared with chemotherapy, while the type of intensification therapy did not influenced the outcome of patients with low MRD levels. Multivariate analysis revealed age, MRD and cytogenetics as independent variables. Moreover, a scoring system, easy in clinical practice, was generated based on MRD level and cytogenetics. PMID:26598032

  13. Stimulating endogenous cardiac repair

    PubMed Central

    Finan, Amanda; Richard, Sylvain

    2015-01-01

    The healthy adult heart has a low turnover of cardiac myocytes. The renewal capacity, however, is augmented after cardiac injury. Participants in cardiac regeneration include cardiac myocytes themselves, cardiac progenitor cells, and peripheral stem cells, particularly from the bone marrow compartment. Cardiac progenitor cells and bone marrow stem cells are augmented after cardiac injury, migrate to the myocardium, and support regeneration. Depletion studies of these populations have demonstrated their necessary role in cardiac repair. However, the potential of these cells to completely regenerate the heart is limited. Efforts are now being focused on ways to augment these natural pathways to improve cardiac healing, primarily after ischemic injury but in other cardiac pathologies as well. Cell and gene therapy or pharmacological interventions are proposed mechanisms. Cell therapy has demonstrated modest results and has passed into clinical trials. However, the beneficial effects of cell therapy have primarily been their ability to produce paracrine effects on the cardiac tissue and recruit endogenous stem cell populations as opposed to direct cardiac regeneration. Gene therapy efforts have focused on prolonging or reactivating natural signaling pathways. Positive results have been demonstrated to activate the endogenous stem cell populations and are currently being tested in clinical trials. A potential new avenue may be to refine pharmacological treatments that are currently in place in the clinic. Evidence is mounting that drugs such as statins or beta blockers may alter endogenous stem cell activity. Understanding the effects of these drugs on stem cell repair while keeping in mind their primary function may strike a balance in myocardial healing. To maximize endogenous cardiac regeneration, a combination of these approaches could ameliorate the overall repair process to incorporate the participation of multiple cellular players. PMID:26484341

  14. DNA repair in cultured keratinocytes

    SciTech Connect

    Liu, S.C.; Parsons, S.; Hanawalt, P.C.

    1983-07-01

    Most of our understanding of DNA repair mechanisms in human cells has come from the study of these processes in cultured fibroblasts. The unique properties of keratinocytes and their pattern of terminal differentiation led us to a comparative examination of their DNA repair properties. The relative repair capabilities of the basal cells and the differentiated epidermal keratinocytes as well as possible correlations of DNA repair capacity with respect to age of the donor have been examined. In addition, since portions of human skin are chronically exposed to sunlight, the repair response to ultraviolet (UV) irradiation (254 nm) when the cells are conditioned by chronic low-level UV irradiation has been assessed. The comparative studies of DNA repair in keratinocytes from infant and aged donors have revealed no significant age-related differences for repair of UV-induced damage to DNA. Sublethal UV conditioning of cells from infant skin had no appreciable effect on either the repair or normal replication response to higher, challenge doses of UVL. However, such conditioning resulted in attenuated repair in keratinocytes from adult skin after UV doses above 25 J/m2. In addition, a surprising enhancement in replication was seen in conditioned cells from adult following challenge UV doses.

  15. Cytogenetic profiles in multiple myeloma and monoclonal gammopathy of undetermined significance: a study in highly purified aberrant plasma cells

    PubMed Central

    Schmidt-Hieber, Martin; Gutiérrez, María Laura; Pérez-Andrés, Martin; Paiva, Bruno; Rasillo, Ana; Tabernero, Maria Dolores; Sayagués, José Maria; Lopez, Antonio; Bárcena, Paloma; Sanchez, María Luz; Gutiérrez, Norma C.; San Miguel, Jesus F.; Orfao, Alberto

    2013-01-01

    Cytogenetic studies in clonal plasma cell disorders have mainly been done in whole bone marrow or CD138+ microbead-enriched plasma cells and suggest that recurrent immunoglobulin heavy chain translocations - e.g. t(4;14) -are primary oncogenetic events. The aim of this study was to determine cytogenetic patterns of highly purified aberrant plasma cells (median purity ≥98%) in different clonal plasma cell disorders. We analyzed aberrant plasma cells from 208 patients with multiple myeloma (n=148) and monoclonal gammopathy of undetermined significance (n=60) for the presence of del(13q14), del(17p13) and t(14q32) using multicolor interphase fluorescence in situ hybridization. Additionally, immunoglobulin heavy chain gene arrangements were analyzed and complementarity determining region 3 was sequenced in a subset of patients and combined multicolor interphase fluorescence in situ hybridization/immunofluorescent protein staining analyses were performed in selected cases to confirm clonality and cytogenetic findings. At diagnosis, 96% of cases with multiple myeloma versus 77% of monoclonal gammopathy of undetermined significance cases showed at least one cytogenetic alteration and/or hyperdiploidy. The cytogenetic heterogeneity of individual cases reflected coexistence of cytogenetically-defined aberrant plasma cell clones, and led to the assumption that karyotypic alterations were acquired stepwise. Cases of multiple myeloma and monoclonal gammopathy of undetermined significance frequently showed different but related cytogenetic profiles when other cytogenetic alterations such as deletions/gains of the immunoglobulin heavy chain or the fibroblast growth factor receptor 3 were additionally considered. Interestingly, in 24% of multiple myeloma versus 62% of monoclonal gammopathy of undetermined significance patients with an immunoglobulin heavy chain translocation, aberrant plasma cells with and without t(14q32) coexisted in the same patient. Our data suggest that

  16. Bi-objective redundancy allocation problem for a system with mixed repairable and non-repairable components.

    PubMed

    Zoulfaghari, Hossein; Zeinal Hamadani, Ali; Abouei Ardakan, Mostafa

    2014-01-01

    Traditionally, in the redundancy allocation problem (RAP), two general classes of optimization problems are considered; reliability optimization and availability optimization. Contrary to reliability optimization, fewer researchers have studied availability optimization to find out the optimal combination of components type and redundancy levels for each subsystem in a system for maximizing (or minimizing) the objectives. In each problem it is assumed that either the entire components are repairable or they are non-repairable. However, in real world situations, systems usually consist of both repairable and non-repairable components. In this paper a new Mixed Integer Nonlinear Programming (MINLP) model is presented to analyze the availability optimization of a system with a given structure, using both repairable and non-repairable components, simultaneously. To find the solution of the introduced MINLP, an efficient Genetic Algorithm (GA) is also developed. Furthermore, to show the efficiency of the proposed GA, a numerical example is presented. Experimental results demonstrate that the proposed GA has a better performance compared to one of the most recommended algorithm in the literature. PMID:23998944

  17. Complex reorganization and predominant non-homologous repair following chromosomal breakage in karyotypically balanced germline rearrangements and transgenic integration

    PubMed Central

    Chiang, Colby; Jacobsen, Jessie C.; Ernst, Carl; Hanscom, Carrie; Heilbut, Adrian; Blumenthal, Ian; Mills, Ryan E.; Kirby, Andrew; Lindgren, Amelia M.; Rudiger, Skye R.; McLaughlan, Clive J.; Bawden, C. Simon; Reid, Suzanne J.; Faull, Richard L. M.; Snell, Russell G.; Hall, Ira M.; Shen, Yiping; Ohsumi, Toshiro K.; Borowsky, Mark L.; Daly, Mark J.; Lee, Charles; Morton, Cynthia C.; MacDonald, Marcy E.; Gusella, James F.; Talkowski, Michael E.

    2012-01-01

    We defined the genetic landscape of balanced chromosomal rearrangements at nucleotide resolution by sequencing 141 breakpoints from cytogenetically-interpreted translocations and inversions. We confirm that the recently described phenomenon of “chromothripsis” (massive chromosomal shattering and reorganization) is not unique to cancer cells but also occurs in the germline where it can resolve to a karyotypically balanced state with frequent inversions. We detected a high incidence of complex rearrangements (19.2%) and substantially less reliance on microhomology (31%) than previously observed in benign CNVs. We compared these results to experimentally-generated DNA breakage-repair by sequencing seven transgenic animals, and revealed extensive rearrangement of the transgene and host genome with similar complexity to human germline alterations. Inversion is the most common rearrangement, suggesting that a combined mechanism involving template switching and non-homologous repair mediates the formation of balanced complex rearrangements that are viable, stably replicated and transmitted unaltered to subsequent generations. PMID:22388000

  18. DNA repair: Dynamic defenders against cancer and aging

    SciTech Connect

    Fuss, Jill O.; Cooper, Priscilla K.

    2006-04-01

    ) component of sunlight. NER can be divided into two classes based on where the repair occurs. NER occurring in DNA that is not undergoing transcription (i.e., most of the genome) is called global genome repair (GGR or GGNER), while NER taking place in the transcribed strand of active genes is called transcription-coupled repair (TCR or TC-NER). We will explore NER in more detail below. Mismatch repair (MMR) is another type of excision repair that specifically removes mispaired bases resulting from replication errors. DNA damage can also result in breaks in the DNA backbone, in one or both strands. Single-strand breaks (SSBs) are efficiently repaired by a mechanism that shares common features with the later steps in BER. Double-strand breaks (DSBs) are especially devastating since by definition there is no intact complementary strand to serve as a template for repair, and even one unrepaired DSB can be lethal [3]. In cells that have replicated their DNA prior to cell division, the missing information can be supplied by the duplicate copy, or sister chromatid, and DSBs in these cells are faithfully repaired by homologous recombination involving the exchange of strands of DNA between the two copies. However, most cells in the body are non-dividing, and in these cells the major mechanism for repairing DSBs is by non-homologous end joining (NHEJ), which as the name implies involves joining two broken DNA ends together without a requirement for homologous sequence and which therefore has a high potential for loss of genetic information.

  19. Combined Use of Cytogenetic and Molecular Methods in Prenatal Diagnostics of Chromosomal Abnormalities

    PubMed Central

    Stomornjak-Vukadin, Meliha; Kurtovic-Basic, Ilvana; Mehinovic, Lejla; Konjhodzic, Rijad

    2015-01-01

    Aim: The aim of prenatal diagnostics is to provide information of the genetic abnormalities of the fetus early enough for the termination of pregnancy to be possible. Chromosomal abnormalities can be detected in an unborn child through the use of cytogenetic, molecular- cytogenetic and molecular methods. In between them, central spot is still occupied by cytogenetic methods. In cases where use of such methods is not informative enough, one or more molecular cytogenetic methods can be used for further clarification. Combined use of the mentioned methods improves the quality of the final findings in the diagnostics of chromosomal abnormalities, with classical cytogenetic methods still occupying the central spot. Material and methods: Conducted research represent retrospective-prospective study of a four year period, from 2008 through 2011. In the period stated, 1319 karyotyping from amniotic fluid were conducted, along with 146 FISH analysis. Results: Karyotyping had detected 20 numerical and 18 structural aberrations in that period. Most common observed numerical aberration were Down syndrome (75%), Klinefelter syndrome (10%), Edwards syndrome, double Y syndrome and triploidy (5% each). Within observed structural aberrations more common were balanced chromosomal aberrations then non balanced ones. Most common balanced structural aberrations were as follows: reciprocal translocations (60%), Robertson translocations (13.3%), chromosomal inversions, duplications and balanced de novo chromosomal rearrangements (6.6% each). Conclusion: With non- balanced aberrations observed in the samples of amniotic fluid, non- balanced translocations, deletions and derived chromosomes were equally represented. Number of detected aneuploidies with FISH, prior to obtaining results with karyotyping, were 6. PMID:26005269

  20. Dioxins and cytogenetic status of villagers after 40 years of agent Orange application in Vietnam.

    PubMed

    Sycheva, Lyudmila P; Umnova, Nataliya V; Kovalenko, Maria A; Zhurkov, Vjacheslav S; Shelepchikov, Andrey A; Roumak, Vladimir S

    2016-02-01

    We have examined cytogenetic status of the rural population living on dioxin-contaminated territories (DCT, TCDD in soil 2.6 ng/kg) compared to the villagers of the control area (TCDD in soil 0.18 ng kg(-1)). The examination took place almost 40 years after the war. The consequences of some confounding factors (years of residence in the region, farming, and aging) has been examined. Karyological analysis of buccal and nasal epitheliocytes among healthy adult males living on DCT and control area (26 and 35 persons) was conducted. A wide range of cytogenetic (micronuclei, nuclear protrusions), proliferative (binucleated cells and cells with doubled nucleus) and endpoints of cell death (cells with perinuclear vacuoles, with damaged nucleus membrane, condensed chromatin, pyknosis, karyorrhexis, karyolysis) had been analyzed. The frequent amount of cells with nuclear protrusions in both epithelia was slightly decreased in the DСT group. Biomarkers of early and late stages of nuclear destruction in buccal epithelium (cells with damaged nuclear membrane, karyolysis) were elevated significantly in DCT. Higher level of the same parameters was also identified in nasal epithelium. The cytogenetic status of healthy adult males on DCT had got "normalization" by present moment in comparison with our early data. Nevertheless, in exposed group some alteration of the cytogenetic status was being registered (mostly biomarkers of apoptosis). Years of residence (and exposure to dioxins) affected the cytogenetic status of DCT inhabitants, whereas no influence of farming factors (pesticides, fertilizers, etc.) had been discovered. Some biomarkers of proliferation and cell death were affected by aging. PMID:26495825

  1. Surgical repair of myelomeningocele.

    PubMed

    Lanigan, M W

    1993-12-01

    The birth of an infant with myelomeningocele provides a devastating experience for parents, a management dilemma for medical personnel, and an economic liability of immense proportions associated with the multiple disciplinary management program throughout the patient's life. Although undue delay in the onset of therapy is to be avoided, time can be taken for through assessment and appropriate discussion with the family without compromising the outcome. Once decisions are made to proceed with repair, early cover of the myelomeningocele defect is necessary to prevent progressive loss of neural tissue through exposure, desiccation, and sepsis. Many techniques of repair have been advocated. In principle, the ideal should be applicable to all sizes of defect, should be able to be executed in the neonatal age group with minimal morbidity, and should provide long-term, stable soft tissue cover without significant secondary scarring. A technique adhering to these principles is described and supported by results in a personal series of 84 patients during a 12-year period. PMID:8297082

  2. Chromosome position determines the success of double-strand break repair

    PubMed Central

    Lee, Cheng-Sheng; Wang, Ruoxi W.; Chang, Hsiao-Han; Capurso, Daniel; Segal, Mark R.; Haber, James E.

    2016-01-01

    Repair of a chromosomal double-strand break (DSB) by gene conversion depends on the ability of the broken ends to encounter a donor sequence. To understand how chromosomal location of a target sequence affects DSB repair, we took advantage of genome-wide Hi-C analysis of yeast chromosomes to create a series of strains in which an induced site-specific DSB in budding yeast is repaired by a 2-kb donor sequence inserted at different locations. The efficiency of repair, measured by cell viability or competition between each donor and a reference site, showed a strong correlation (r = 0.85 and 0.79) with the contact frequencies of each donor with the DSB repair site. Repair efficiency depends on the distance between donor and recipient rather than any intrinsic limitation of a particular donor site. These results further demonstrate that the search for homology is the rate-limiting step in DSB repair and suggest that cells often fail to repair a DSB because they cannot locate a donor before other, apparently lethal, processes arise. The repair efficiency of a donor locus can be improved by four factors: slower 5′ to 3′ resection of the DSB ends, increased abundance of replication protein factor A (RPA), longer shared homology, or presence of a recombination enhancer element adjacent to a donor. PMID:26715752

  3. Pectoralis Major Tendon Repair

    PubMed Central

    Cordasco, Frank A.; Degen, Ryan; Mahony, Gregory Thomas; Tsouris, Nicholas

    2016-01-01

    Objectives: Systematic reviews of the literature have identified 365 reported cases of Pectoralis Major Tendon (PMT) injuries. While surgical treatment has demonstrated improved outcomes compared to non-operative treatment, there is still relatively limited data on the functional outcome, return to sport and need for 2nd surgery in athletes following PMT repair. This study comprises the largest series of athletes following PMT repair reported to date. The Objective is to report on the functional outcomes, return to sport and need for 2nd surgery in a consecutive series of PMT tears. Methods: From 2009, 81 patients with PMT tears were enrolled in this prospective series. Baseline evaluation included patient demographics, mechanism of injury, physical examination and PMT specific MRI for confirmation of the diagnosis and analysis of the extent of injury. Each patient underwent surgical repair by the senior author utilizing a previously published surgical technique. Patients were then followed at 2 weeks, 6 weeks, 3 months and 6 months and further follow-up was conducted annually thereafter with functional outcome scores and adduction strength testing. The return to sport and incidence of 2nd surgery data were recorded. This study includes the first 40 athletes to reach the 2-year post-operative period. Results: All athletes were male, with an average age of 34.4 years (range 23-59). The patient cohort consisted of 4 professional NFL players and 36 recreational athletes. Average follow-up duration was 2.5 years (range 2 - 6.0 years). The most common mechanisms of injury occurred during the bench press (n=26) and contact sport participation (n=14). Sixteen injuries were complete avulsions involving both the clavicular and sternocostal heads, while 24 were isolated sternocostal head avulsions. Average pre-injury bench press of 396 lbs (range 170-500 lbs) was restored to 241 lbs post-operatively (range 140-550 lbs). Single Assessment Numeric Evaluation (SANE) scores

  4. Industrial motor repair in the United States

    SciTech Connect

    Schueler, V.; Leistner, P.; Douglass, J.

    1994-09-01

    This report characterizes the motor repair industry in the United States; summarizes current motor repair and testing practice; and identifies barriers to energy motor repair practice and recommends strategies for overcoming those barriers.

  5. Laparoscopic paracolostomy hernia mesh repair.

    PubMed

    Virzí, Giuseppe; Giuseppe, Virzí; Scaravilli, Francesco; Francesco, Scaravilli; Ragazzi, Salvatore; Salvatore, Ragazzi; Piazza, Diego; Diego, Piazza

    2007-12-01

    Paracolostomy hernia is a common occurrence, representing a late complication of stoma surgery. Different surgical techniques have been proposed to repair the wall defect, but the lowest recurrence rates are associated with the use of mesh. We present the case report of a patient in which laparoscopic paracolostomy hernia mesh repair has been successfully performed. PMID:18097321

  6. Instructional Guide for Autobody Repair.

    ERIC Educational Resources Information Center

    Virginia Polytechnic Inst. and State Univ., Blacksburg. Dept. of Education.

    The curriculum guide was developed to serve as a statewide model for Virginia auto body repair programs. The guide is designed to 1,080 hours of instruction in eleven blocks: orientation, introduction, welding and cutting, techniques of shaping metal, body filler and fiberglass repairs, body and frame, removing and replacing damaged parts, basic…

  7. Cobbler's Technique for Iridodialysis Repair

    PubMed Central

    Pandav, Surinder Singh; Gupta, Parul Chawla; Singh, Rishi Raj; Das, Kalpita; Kaushik, Sushmita; Raj, Srishti; Ram, Jagat

    2016-01-01

    We describe a novel “Cobbler's technique” for iridodialysis repair in the right eye of a patient aged 18 years, with a traumatic iridodialysis secondary to open globe injury with an iron rod. Our technique is simple with easy surgical maneuvers, that is, effective for repairing iridodialysis. The “Cobbler's technique” allows a maximally functional and cosmetic result for iridodialysis. PMID:26957855

  8. Pipe inspection and repair system

    NASA Technical Reports Server (NTRS)

    Schempf, Hagen (Inventor); Mutschler, Edward (Inventor); Chemel, Brian (Inventor); Boehmke, Scott (Inventor); Crowley, William (Inventor)

    2004-01-01

    A multi-module pipe inspection and repair device. The device includes a base module, a camera module, a sensor module, an MFL module, a brush module, a patch set/test module, and a marker module. Each of the modules may be interconnected to construct one of an inspection device, a preparation device, a marking device, and a repair device.

  9. Major Appliance Repair. Teacher Edition.

    ERIC Educational Resources Information Center

    Smreker, Eugene; Calvert, King

    This module is a comprehensive text on basic appliance repair, designed to prepare students for entry-level jobs in this growing field. Ensuring a firm grounding in electrical knowledge, the module contains 13 instructional units that cover the following topics: (1) major appliance repair orientation; (2) safety and first aid; (3) fundamentals of…

  10. Membrane Repair: Mechanisms and Pathophysiology.

    PubMed

    Cooper, Sandra T; McNeil, Paul L

    2015-10-01

    Eukaryotic cells have been confronted throughout their evolution with potentially lethal plasma membrane injuries, including those caused by osmotic stress, by infection from bacterial toxins and parasites, and by mechanical and ischemic stress. The wounded cell can survive if a rapid repair response is mounted that restores boundary integrity. Calcium has been identified as the key trigger to activate an effective membrane repair response that utilizes exocytosis and endocytosis to repair a membrane tear, or remove a membrane pore. We here review what is known about the cellular and molecular mechanisms of membrane repair, with particular emphasis on the relevance of repair as it relates to disease pathologies. Collective evidence reveals membrane repair employs primitive yet robust molecular machinery, such as vesicle fusion and contractile rings, processes evolutionarily honed for simplicity and success. Yet to be fully understood is whether core membrane repair machinery exists in all cells, or whether evolutionary adaptation has resulted in multiple compensatory repair pathways that specialize in different tissues and cells within our body. PMID:26336031

  11. Pipeline repair technique cuts downtime

    SciTech Connect

    Bellamy, G.; Jouanneau, J.F.; Quin, R.; Wiet, P.

    1985-02-11

    This article deals with a project that explored the cold-tapping technique for repairing or modifying sea gas lines. The technique allows work to be carried out on a section of pipeline without the need, as before, for the flooding of the line, and subsequent dewatering and drying of the line. Lost production time is greatly reduced. Cold-tapping is performed on a pipe depressurized at the same level as the sea-bed hydrostatic pressure. The system is designed to withstand an accidental depressurization of the pipe to the atmosphere pressure with a safety factor of one third. The technique is simple, allows for accurate positioning of the plugs, and offers a maximum reliability due to an efficient monitoring and a wide range of backup procedures. Keeping the line entirely free of extra pieces of equipment after the operation is also a major advantage. The entire operation described took 34 hours during which all the required tasks were performed flawlessly. Analysis of the data collected during the test program showed that cold-tapping required a maximum of four extra barge days. It was demonstrated that the method can save up to eight weeks of gas-pipeline shutdown time.

  12. DNA Repair Pathway Gene Expression Score Correlates with Repair Proficiency and Tumor Sensitivity to Chemotherapy

    PubMed Central

    Pitroda, Sean. P.; Pashtan, Itai. M.; Logan, Hillary. L.; Budke, Brian; Darga, Thomas E.; Weichselbaum, Ralph. R.; Connell, Philip. P.

    2016-01-01

    Homologous recombination (HR) and non-homologous end joining (NHEJ) are alternative pathways of double-strand DNA break repair. We developed a method to quantify the efficiency of DNA repair pathways in the context of cancer therapy. The Recombination Proficiency Score (RPS) utilizes the expression levels for four genes involved in DNA repair pathway preference (RIF1, PARI, RAD51, and Ku80), such that high expression of these genes yields a low RPS. Carcinoma cells with low RPS exhibit HR suppression and frequent DNA copy number alterations, which are characteristic of error-prone repair processes that arise in HR-deficient backgrounds. The RPS system was clinically validated in patients with breast or non-small cell lung carcinomas (NSCLC). Tumors with low RPS were associated with greater mutagenesis, adverse clinical features, and inferior patient survival rates, suggesting that HR suppression plays a central role in promoting the genomic instability that fuels malignant progression. This adverse prognosis associated with low RPS was diminished if NSCLC patients received adjuvant chemotherapy, suggesting that HR suppression and associated sensitivity to platinum-based drugs counteracts the adverse prognosis associated with low RPS. Therefore, RPS may predict which therapies will be effective for individual patients, thereby enabling more personalized oncology care. PMID:24670686

  13. Rethinking transcription coupled DNA repair.

    PubMed

    Kamarthapu, Venu; Nudler, Evgeny

    2015-04-01

    Nucleotide excision repair (NER) is an evolutionarily conserved, multistep process that can detect a wide variety of DNA lesions. Transcription coupled repair (TCR) is a subpathway of NER that repairs the transcribed DNA strand faster than the rest of the genome. RNA polymerase (RNAP) stalled at DNA lesions mediates the recruitment of NER enzymes to the damage site. In this review we focus on a newly identified bacterial TCR pathway in which the NER enzyme UvrD, in conjunction with NusA, plays a major role in initiating the repair process. We discuss the tradeoff between the new and conventional models of TCR, how and when each pathway operates to repair DNA damage, and the necessity of pervasive transcription in maintaining genome integrity. PMID:25596348

  14. Engineering skeletal muscle repair.

    PubMed

    Juhas, Mark; Bursac, Nenad

    2013-10-01

    Healthy skeletal muscle has a remarkable capacity for regeneration. Even at a mature age, muscle tissue can undergo a robust rebuilding process that involves the formation of new muscle cells and extracellular matrix and the re-establishment of vascular and neural networks. Understanding and reverse-engineering components of this process is essential for our ability to restore loss of muscle mass and function in cases where the natural ability of muscle for self-repair is exhausted or impaired. In this article, we will describe current approaches to restore the function of diseased or injured muscle through combined use of myogenic stem cells, biomaterials, and functional tissue-engineered muscle. Furthermore, we will discuss possibilities for expanding the future use of human cell sources toward the development of cell-based clinical therapies and in vitro models of human muscle disease. PMID:23711735

  15. TPS Inspection and Repair

    NASA Technical Reports Server (NTRS)

    Parazynski, Scott

    2012-01-01

    Dr. Scott Parazynski provided a retrospective on the EVA tools and procedures efforts NASA went through in the aftermath of Columbia for the Shuttle Thermal Protection System (TPS) inspection and repair. He describes his role as the lead astronaut on this effort, and covered all of the Neutral Buoyancy Lab (NBL), KC 135 (reduced gravity aircraft), Precision Air Bearing Floor (PABF), vacuum chamber and 1 G testing that was done in order to develop the tools and techniques that were flown. Parazynski also discusses how the EVA community worked together to resolve a huge safety issue, and how his work in the spacesuit was critical to overcoming a design limitation of the Space Shuttle.

  16. Wound repair in Pocillopora.

    PubMed

    Rodríguez-Villalobos, Jenny Carolina; Work, Thierry Martin; Calderon-Aguilera, Luis Eduardo

    2016-09-01

    Corals routinely lose tissue due to causes ranging from predation to disease. Tissue healing and regeneration are fundamental to the normal functioning of corals, yet we know little about this process. We described the microscopic morphology of wound repair in Pocillopora damicornis. Tissue was removed by airbrushing fragments from three healthy colonies, and these were monitored daily at the gross and microscopic level for 40days. Grossly, corals healed by Day 30, but repigmentation was not evident at the end of the study (40d). On histology, from Day 8 onwards, tissues at the lesion site were microscopically indistinguishable from adjacent normal tissues with evidence of zooxanthellae in gastrodermis. Inflammation was not evident. P. damicornis manifested a unique mode of regeneration involving projections of cell-covered mesoglea from the surface body wall that anastomosed to form gastrovascular canals. PMID:27397755

  17. Wound repair in Pocillopora

    USGS Publications Warehouse

    Rodríguez-Villalobos, Jenny Carolina; Work, Thierry M.; Calderon-Aguileraa, Luis Eduardo

    2016-01-01

    Corals routinely lose tissue due to causes ranging from predation to disease. Tissue healing and regeneration are fundamental to the normal functioning of corals, yet we know little about this process. We described the microscopic morphology of wound repair in Pocillopora damicornis. Tissue was removed by airbrushing fragments from three healthy colonies, and these were monitored daily at the gross and microscopic level for 40 days. Grossly, corals healed by Day 30, but repigmentation was not evident at the end of the study (40 d). On histology, from Day 8 onwards, tissues at the lesion site were microscopically indistinguishable from adjacent normal tissues with evidence of zooxanthellae in gastrodermis. Inflammation was not evident. P. damicornis manifested a unique mode of regeneration involving projections of cell-covered mesoglea from the surface body wall that anastomosed to form gastrovascular canals.

  18. Defect repair performance using the nanomachining repair technique

    NASA Astrophysics Data System (ADS)

    Morikawa, Yasutaka; Kokubo, Haruo; Nishiguchi, Masaharu; Hayashi, Naoya; White, Roy; Bozak, Ron; Terrill, Lee

    2003-08-01

    Nanomachining is a new technique for repairing photomask defects. The advantages of this technique are no substrate damage, precise edge placement position and Z height accuracy when compared with current Laser zapper or FIB GAE repair techniques. This technique can be applied to any type of opaque defects at any type of film materials and quartz bump defects on Alternating Aperture Phase Sifting Masks (AAPSM). Furthermore, these characteristics enable complex pattern repairs of most advanced photomasks for 193nm lithography and enables iterative repair to achieve improved printing performance when analyzed with an AIMS 193nm tool. Dai Nippon Printing Co., Ltd. (DNP) has been producing AAPSMs in mass production for quite some time. The standard type of AAPSMs manufactured has been etched quartz, single trench with an undercut structure. On this structure, there is a potential for quartz defects underneath the chrome overhang based on the combination of dry and wet etching to create the undercut. For this study, we fabricated this kind of designed quartz defects and repaired them using the nanomachining system. These types of defects are particularly difficult to repair perfectly because they exist underneath the chrome overhang. We will show some options to achieve better printing results through the repair of these kinds of defects. In this report, we confirmed basic performance of this technique such as edge placement accuracy, Z height accuracy and AIMS printability. Additionally, we also tried to repair some complex defects such as quartz defects of AAPSM, quartz defects of CPL mask and oversized Serifs for application options. We will show these nanomachining repairs with evaluation results of printing performance simulated by the AIMS 193nm tool.

  19. An informative constitutional cytogenetic marker found in a patient post bone marrow transplantation

    SciTech Connect

    Zaslav, A.L.; Graziano, J.; Ebert, R.

    1994-09-01

    It is cytogenetically difficult to distinguish between host and donor cells in allogeneic bone marrow transplantation (BMT) individuals of the same sex. Here we describe a patient with a cytogenetic marker found after BMT. A 7-month-old male presented with leukemia which was CD7+, CD33+, HLADR+, and CD4-, CD8-, indicating a diagnosis of acute stem cell leukemia (ASCL). Cytogenetic analysis revealed an abnormal clone in all of the cells analyzed: 46,XY,t(2;8)(p11.2;q24),inv(9)(p13p24). This translocation is associated with B-cell acute lymphoblastic leukemia (ALL); thus, it was possible for this patient to develop B-cell ALL. The abnormal clone persisted along with normal 46,XY cells, and evolved in several of seven additional analyses. The patient was treated with two courses of chemotherapy and failed to attain cytogenetic remission. While in relapse, the patient received a BMT from his 3-year-old brother. Two weeks later, a different translocation was seen in all cells: 46,XY,t(3;12)(p21;q21). This result could be interpreted in two ways: (1) the structural abnormality was indicative of a newly evolved clone related to the patient`s disease; or (2) the donor was a balanced translocation carrier. Cytogenetic analysis of peripheral blood from the donor revealed the same translocation seen in the patient. Parental blood chromosomes were normal indicating that the donor carried a de novo balanced translocation. Subsequent chromosome analysis of both peripheral blood and BM from the patient revealed the presence of the translocation in all cells. De novo balanced translocations are rare and occur with a frequency of 1/2,000 live borns. The family received genetic counseling and was informed of the possible reproductive risks to translocation carriers. This unusual finding will serve as a useful cytogenetic marker to assist in monitoring the patient`s clinical course, i.e., chimerism and remission status.

  20. Effect of Carcinogenic Acrolein on DNA Repair and Mutagenic Susceptibility*

    PubMed Central

    Wang, Hsiang-Tsui; Hu, Yu; Tong, Dan; Huang, Jian; Gu, Liya; Wu, Xue-Ru; Chung, Fung-Lung; Li, Guo-Min; Tang, Moon-shong

    2012-01-01

    Acrolein (Acr), a ubiquitous environmental contaminant, is a human carcinogen. Acr can react with DNA to form mutagenic α- and γ-hydroxy-1, N2-cyclic propano-2′-deoxyguanosine adducts (α-OH-Acr-dG and γ-OH-Acr-dG). We demonstrate here that Acr-dG adducts can be efficiently repaired by the nucleotide excision repair (NER) pathway in normal human bronchial epithelia (NHBE) and lung fibroblasts (NHLF). However, the same adducts were poorly processed in cell lysates isolated from Acr-treated NHBE and NHLF, suggesting that Acr inhibits NER. In addition, we show that Acr treatment also inhibits base excision repair and mismatch repair. Although Acr does not change the expression of XPA, XPC, hOGG1, PMS2 or MLH1 genes, it causes a reduction of XPA, XPC, hOGG1, PMS2, and MLH1 proteins; this effect, however, can be neutralized by the proteasome inhibitor MG132. Acr treatment further enhances both bulky and oxidative DNA damage-induced mutagenesis. These results indicate that Acr not only damages DNA but can also modify DNA repair proteins and further causes degradation of these modified repair proteins. We propose that these two detrimental effects contribute to Acr mutagenicity and carcinogenicity. PMID:22275365

  1. Facilitation of base excision repair by chromatin remodeling.

    PubMed

    Hinz, John M; Czaja, Wioletta

    2015-12-01

    Base Excision Repair (BER) is a conserved, intracellular DNA repair system that recognizes and removes chemically modified bases to insure genomic integrity and prevent mutagenesis. Aberrant BER has been tightly linked with a broad spectrum of human pathologies, such as several types of cancer, neurological degeneration, developmental abnormalities, immune dysfunction and aging. In the cell, BER must recognize and remove DNA lesions from the tightly condensed, protein-coated chromatin. Because chromatin is necessarily refractory to DNA metabolic processes, like transcription and replication, the compaction of the genomic material is also inhibitory to the repair systems necessary for its upkeep. Multiple ATP-dependent chromatin remodelling (ACR) complexes play essential roles in modulating the protein-DNA interactions within chromatin, regulating transcription and promoting activities of some DNA repair systems, including double-strand break repair and nucleotide excision repair. However, it remains unclear how BER operates in the context of chromatin, and if the chromatin remodelling processes that govern transcription and replication also actively regulate the efficiency of BER. In this review we highlight the emerging role of ACR in regulation of BER. PMID:26422134

  2. Insensitivity of Human iPS Cells-Derived Mesenchymal Stem Cells to Interferon-γ-induced HLA Expression Potentiates Repair Efficiency of Hind Limb Ischemia in Immune Humanized NOD Scid Gamma Mice.

    PubMed

    Sun, Yue-Qi; Zhang, Yuelin; Li, Xin; Deng, Meng-Xia; Gao, Wen-Xiang; Yao, Yin; Chiu, Sin-Ming; Liang, Xiaoting; Gao, Fei; Chan, Camie W; Tse, Hung-Fat; Shi, Jianbo; Fu, Qing-Ling; Lian, Qizhou

    2015-12-01

    Adult mesenchymal stem cells (MSCs) are immunoprivileged cells due to the low expression of major histocompatibility complex (MHC) II molecules. However, the expression of MHC molecules in human-induced pluripotent stem cells (iPSCs)-derived MSCs has not been investigated. Here, we examined the expression of human leukocyte antigen (HLA) in human MSCs derived from iPSCs, fetuses, and adult bone marrow (BM) after stimulation with interferon-γ (IFN-γ), compared their repair efficacy, cell retention, inflammation, and HLA II expression in immune humanized NOD Scid gamma (NSG) mice of hind limb ischemia. In the absence of IFN-γ stimulation, HLA-II was expressed only in BM-MSCs after 7 days. Two and seven days after stimulation, high levels of HLA-II were observed in BM-MSCs, intermediate levels were found in fetal-MSCs, and very low levels in iPSC-MSCs. The levels of p-STAT1, interferon regulatory factor 1, and class II transactivator exhibited similar phenomena. Moreover, p-STAT1 antagonist significantly reversed the high expression of HLA-II in BM-MSCs. Compared to adult BM-MSCs, transplanting iPSC-MSCs into hu-PBMNC NSG mice revealed markedly more survival iPSC-MSCs, less inflammatory cell accumulations, and better recovery of hind limb ischemia. The expression of HLA-II in MSCs in the ischemia limbs was detected in BM-MSCs group but not in iPSC-MSCs group at 7 and 21 days after transplantation. Our results demonstrate that, compared to adult MSCs, human iPSC-MSCs are insensitive to proinflammatory IFN-γ-induced HLA-II expression and iPSC-MSCs have a stronger immune privilege after transplantation. It may attribute to a better therapeutic efficacy in allogeneic transplantation. PMID:26175298

  3. Experimental Fatigue Study of Composite Patch Repaired Steel Plates with Cracks

    NASA Astrophysics Data System (ADS)

    Karatzas, Vasileios A.; Kotsidis, Elias A.; Tsouvalis, Nicholas G.

    2015-10-01

    Cracks are among the most commonly encountered defects in metallic structures operating at sea. Composite patch repairing is a repair method which is gaining popularity as it counters most of the problems faced by conventional renewal repairs. Extensive studies can be found in the literature addressing the efficiency of this novel repair method using techniques which meet higher performance and monitoring standards than these commonly found in naval applications. In this work the efficiency of practices widely used in the ship repair industry for the implementation of composite patch repairing is addressed. To this end, steel plates repaired with composite patches were tested under fatigue loading. The composite patches consisted of carbon fibers in epoxy matrix and were directly laminated to the steel surface using the vacuum infusion method. Two different surface preparation methods, namely grit-blasting and mechanical treatment with the use of a needle gun were studied. In addition, in order to account for the harsh environmental conditions during the operating life of the structure and to study its effect on the repair, two different aging scenarios were considered. Non-destructive evaluation of the patches was performed so as to assess the quality of the repair, and the evolution of debonding during testing.

  4. Cytogenetic abnormalities and monosomal karyotypes in children and adolescents with acute myeloid leukemia: correlations with clinical characteristics and outcome.

    PubMed

    Manola, Kalliopi N; Panitsas, Fotios; Polychronopoulou, Sophia; Daraki, Aggeliki; Karakosta, Maria; Stavropoulou, Cryssa; Avgerinou, Georgia; Hatzipantelis, Emmanuel; Pantelias, Gabriel; Sambani, Constantina; Pagoni, Maria

    2013-03-01

    The whole spectrum of chromosomal abnormalities and their prognostic significance in children and adolescents with acute myeloid leukemia (AML) has not been fully elucidated yet, although a considerable amount of knowledge has been gained recently. Moreover, the incidence and prognostic impact of monosomal karyotypes (MKs), which are new cytogenetic categories reported recently in adults with AML, are currently unknown for childhood and adolescent AML. In this study, we investigated the cytogenetic and clinical characteristics of 140 children and adolescents (≤21 y) with AML, and correlated their cytogenetic features with both the clinical characteristics and outcomes of our patient cohort. The most frequent cytogenetic abnormality found in our study was the t(15;17), followed by the t(8;21). Striking differences in the genetic abnormalities and French-American-British subtypes were found among infants, children, and adolescents. Of 124 cases, 15 (12.1%) met the criteria of the MK definition, and 12 of the 15 MKs (80%) were complex karyotypes. Of 124 cases, 27 (21.8%) had cytogenetic abnormalities sufficient to be diagnosed as AML with myelodyspastic sydrome-related features. As expected, patients with the t(15;17) had the most favorable outcomes, whereas patients with 11q23 rearrangements and monosomy 7 had the worst outcomes. These data expand our knowledge by providing novel insights into the cytogenetic features and their correlations with clinical characteristics and outcomes in childhood and adolescent AML. PMID:23411131

  5. Treatment of multiple myeloma with high-risk cytogenetics: a consensus of the International Myeloma Working Group

    PubMed Central

    Avet-Loiseau, Hervé; Lonial, Sagar; Usmani, Saad; Siegel, David; Anderson, Kenneth C.; Chng, Wee-Joo; Moreau, Philippe; Attal, Michel; Kyle, Robert A.; Caers, Jo; Hillengass, Jens; San Miguel, Jesús; van de Donk, Niels W. C. J.; Einsele, Hermann; Bladé, Joan; Durie, Brian G. M.; Goldschmidt, Hartmut; Mateos, María-Victoria; Palumbo, Antonio; Orlowski, Robert

    2016-01-01

    The International Myeloma Working Group consensus updates the definition for high-risk (HR) multiple myeloma based on cytogenetics Several cytogenetic abnormalities such as t(4;14), del(17/17p), t(14;16), t(14;20), nonhyperdiploidy, and gain(1q) were identified that confer poor prognosis. The prognosis of patients showing these abnormalities may vary with the choice of therapy. Treatment strategies have shown promise for HR cytogenetic diseases, such as proteasome inhibition in combination with lenalidomide/pomalidomide, double autologous stem cell transplant plus bortezomib, or combination of immunotherapy with lenalidomide or pomalidomide. Careful analysis of cytogenetic subgroups in trials comparing different treatments remains an important goal. Cross-trial comparisons may provide insight into the effect of new drugs in patients with cytogenetic abnormalities. However, to achieve this, consensus on definitions of analytical techniques, proportion of abnormal cells, and treatment regimens is needed. Based on data available today, bortezomib and carfilzomib treatment appear to improve complete response, progression-free survival, and overall survival in t(4;14) and del(17/17p), whereas lenalidomide may be associated with improved progression-free survival in t(4;14) and del(17/17p). Patients with multiple adverse cytogenetic abnormalities do not benefit from these agents. FISH data are implemented in the revised International Staging System for risk stratification. PMID:27002115

  6. Treatment of multiple myeloma with high-risk cytogenetics: a consensus of the International Myeloma Working Group.

    PubMed

    Sonneveld, Pieter; Avet-Loiseau, Hervé; Lonial, Sagar; Usmani, Saad; Siegel, David; Anderson, Kenneth C; Chng, Wee-Joo; Moreau, Philippe; Attal, Michel; Kyle, Robert A; Caers, Jo; Hillengass, Jens; San Miguel, Jesús; van de Donk, Niels W C J; Einsele, Hermann; Bladé, Joan; Durie, Brian G M; Goldschmidt, Hartmut; Mateos, María-Victoria; Palumbo, Antonio; Orlowski, Robert

    2016-06-16

    The International Myeloma Working Group consensus updates the definition for high-risk (HR) multiple myeloma based on cytogenetics Several cytogenetic abnormalities such as t(4;14), del(17/17p), t(14;16), t(14;20), nonhyperdiploidy, and gain(1q) were identified that confer poor prognosis. The prognosis of patients showing these abnormalities may vary with the choice of therapy. Treatment strategies have shown promise for HR cytogenetic diseases, such as proteasome inhibition in combination with lenalidomide/pomalidomide, double autologous stem cell transplant plus bortezomib, or combination of immunotherapy with lenalidomide or pomalidomide. Careful analysis of cytogenetic subgroups in trials comparing different treatments remains an important goal. Cross-trial comparisons may provide insight into the effect of new drugs in patients with cytogenetic abnormalities. However, to achieve this, consensus on definitions of analytical techniques, proportion of abnormal cells, and treatment regimens is needed. Based on data available today, bortezomib and carfilzomib treatment appear to improve complete response, progression-free survival, and overall survival in t(4;14) and del(17/17p), whereas lenalidomide may be associated with improved progression-free survival in t(4;14) and del(17/17p). Patients with multiple adverse cytogenetic abnormalities do not benefit from these agents. FISH data are implemented in the revised International Staging System for risk stratification. PMID:27002115

  7. How to repair an episiotomy.

    PubMed

    Steen, Mary; Cummins, Bernie

    2016-02-17

    Rationale and key points Skilful repair of an episiotomy is an important aspect of maternal health care. It is essential that midwives and doctors have the knowledge and skills to undertake this procedure in a safe and effective manner. ▶ An episiotomy should be repaired promptly to reduce blood loss and prevent infection. ▶ Repair of an episiotomy is undertaken in three stages: repair of the vaginal mucosa, repair of the muscle layer and repair of the skin layer. ▶ Adequate pain relief should be provided before suturing. Reflective activity Clinical skills articles can help update your practice and ensure it remains evidence based. Apply this article to your practice. Reflect on and write a short account of: 1. Why a rectal examination is recommended before and following repair of an episiotomy. 2. What you would do to improve your suturing skills. 3. The factors that may prevent or delay an episiotomy from healing. Subscribers can upload their reflective accounts at rcni.com/portfolio . PMID:26884039

  8. The Fanconi Anaemia Components UBE2T and FANCM Are Functionally Linked to Nucleotide Excision Repair

    PubMed Central

    Kelsall, Ian R.; Langenick, Judith; MacKay, Craig; Patel, Ketan J.; Alpi, Arno F.

    2012-01-01

    The many proteins that function in the Fanconi anaemia (FA) monoubiquitylation pathway initiate replicative DNA crosslink repair. However, it is not clear whether individual FA genes participate in DNA repair pathways other than homologous recombination and translesion bypass. Here we show that avian DT40 cell knockouts of two integral FA genes – UBE2T and FANCM are unexpectedly sensitive to UV-induced DNA damage. Comprehensive genetic dissection experiments indicate that both of these FA genes collaborate to promote nucleotide excision repair rather than translesion bypass to protect cells form UV genotoxicity. Furthermore, UBE2T deficiency impacts on the efficient removal of the UV-induced photolesion cyclobutane pyrimidine dimer. Therefore, this work reveals that the FA pathway shares two components with nucleotide excision repair, intimating not only crosstalk between the two major repair pathways, but also potentially identifying a UBE2T-mediated ubiquitin-signalling response pathway that contributes to nucleotide excision repair. PMID:22615860

  9. Effects of hyperthermia on DNA repair pathways: one treatment to inhibit them all.

    PubMed

    Oei, Arlene L; Vriend, Lianne E M; Crezee, Johannes; Franken, Nicolaas A P; Krawczyk, Przemek M

    2015-01-01

    The currently available arsenal of anticancer modalities includes many DNA damaging agents that can kill malignant cells. However, efficient DNA repair mechanisms protect both healthy and cancer cells against the effects of treatment and contribute to the development of drug resistance. Therefore, anti-cancer treatments based on inflicting DNA damage can benefit from inhibition of DNA repair. Hyperthermia - treatment at elevated temperature - considerably affects DNA repair, among other cellular processes, and can thus sensitize (cancer) cells to DNA damaging agents. This effect has been known and clinically applied for many decades, but how heat inhibits DNA repair and which pathways are targeted has not been fully elucidated. In this review we attempt to summarize the known effects of hyperthermia on DNA repair pathways relevant in clinical treatment of cancer. Furthermore, we outline the relationships between the effects of heat on DNA repair and sensitization of cells to various DNA damaging agents. PMID:26245485

  10. Prediction of Fatigue Crack Growth of Repaired Al-alloy Structures with Double Sides

    NASA Astrophysics Data System (ADS)

    Benachour, M.; Benachour, N.; Benguediab, M.; Seriari, F. Z.

    During navigation, aircrafts are subject to fatigue damage. In order to rehabilitate damaged structures some techniques are often used to resolve this problem. Efficient repair technique, called composite patch repair, was used to reinforce the damaged structures and stop cracks. In this paper, effect of composite patch repair (Boron/Epoxy) on fatigue crack growth (FCG) was investigated on 2219 T62 Al-alloy. Effects of double patch repair in single notch tensile specimen (SENT) on FCG were studied and compared to single patch repair. Results show beneficial effect of patch repair on fatigue life and FCGR in comparison with the un-patched specimen. In addition, effect of mean stress characterized by stress ratio was highlighted. Fatigue behavior of investigated Al-alloy was compared.

  11. Fibrinolysis is essential for fracture repair and prevention of heterotopic ossification

    PubMed Central

    Yuasa, Masato; Mignemi, Nicholas A.; Nyman, Jeffry S.; Duvall, Craig L.; Schwartz, Herbert S.; Okawa, Atsushi; Yoshii, Toshitaka; Bhattacharjee, Gourab; Zhao, Chenguang; Bible, Jesse E.; Obremskey, William T.; Flick, Matthew J.; Degen, Jay L.; Barnett, Joey V.; Cates, Justin M.M.; Schoenecker, Jonathan G.

    2015-01-01

    Bone formation during fracture repair inevitably initiates within or around extravascular deposits of a fibrin-rich matrix. In addition to a central role in hemostasis, fibrin is thought to enhance bone repair by supporting inflammatory and mesenchymal progenitor egress into the zone of injury. However, given that a failure of efficient fibrin clearance can impede normal wound repair, the precise contribution of fibrin to bone fracture repair, whether supportive or detrimental, is unknown. Here, we employed mice with genetically and pharmacologically imposed deficits in the fibrin precursor fibrinogen and fibrin-degrading plasminogen to explore the hypothesis that fibrin is vital to the initiation of fracture repair, but impaired fibrin clearance results in derangements in bone fracture repair. In contrast to our hypothesis, fibrin was entirely dispensable for long-bone fracture repair, as healing fractures in fibrinogen-deficient mice were indistinguishable from those in control animals. However, failure to clear fibrin from the fracture site in plasminogen-deficient mice severely impaired fracture vascularization, precluded bone union, and resulted in robust heterotopic ossification. Pharmacological fibrinogen depletion in plasminogen-deficient animals restored a normal pattern of fracture repair and substantially limited heterotopic ossification. Fibrin is therefore not essential for fracture repair, but inefficient fibrinolysis decreases endochondral angiogenesis and ossification, thereby inhibiting fracture repair. PMID:26214526

  12. DNA repair in Mycoplasma gallisepticum

    PubMed Central

    2013-01-01

    Background DNA repair is essential for the maintenance of genome stability in all living beings. Genome size as well as the repertoire and abundance of DNA repair components may vary among prokaryotic species. The bacteria of the Mollicutes class feature a small genome size, absence of a cell wall, and a parasitic lifestyle. A small number of genes make Mollicutes a good model for a “minimal cell” concept. Results In this work we studied the DNA repair system of Mycoplasma gallisepticum on genomic, transcriptional, and proteomic levels. We detected 18 out of 22 members of the DNA repair system on a protein level. We found that abundance of the respective mRNAs is less than one per cell. We studied transcriptional response of DNA repair genes of M. gallisepticum at stress conditions including heat, osmotic, peroxide stresses, tetracycline and ciprofloxacin treatment, stationary phase and heat stress in stationary phase. Conclusions Based on comparative genomic study, we determined that the DNA repair system M. gallisepticum includes a sufficient set of proteins to provide a cell with functional nucleotide and base excision repair and mismatch repair. We identified SOS-response in M. gallisepticum on ciprofloxacin, which is a known SOS-inducer, tetracycline and heat stress in the absence of established regulators. Heat stress was found to be the strongest SOS-inducer. We found that upon transition to stationary phase of culture growth transcription of DNA repair genes decreases dramatically. Heat stress does not induce SOS-response in a stationary phase. PMID:24148612

  13. Developing an in silico model of the modulation of base excision repair using methoxyamine for more targeted cancer therapeutics.

    PubMed

    Gurkan-Cavusoglu, Evren; Avadhani, Sriya; Liu, Lili; Kinsella, Timothy J; Loparo, Kenneth A

    2013-04-01

    Base excision repair (BER) is a major DNA repair pathway involved in the processing of exogenous non-bulky base damages from certain classes of cancer chemotherapy drugs as well as ionising radiation (IR). Methoxyamine (MX) is a small molecule chemical inhibitor of BER that is shown to enhance chemotherapy and/or IR cytotoxicity in human cancers. In this study, the authors have analysed the inhibitory effect of MX on the BER pathway kinetics using a computational model of the repair pathway. The inhibitory effect of MX depends on the BER efficiency. The authors have generated variable efficiency groups using different sets of protein concentrations generated by Latin hypercube sampling, and they have clustered simulation results into high, medium and low efficiency repair groups. From analysis of the inhibitory effect of MX on each of the three groups, it is found that the inhibition is most effective for high efficiency BER, and least effective for low efficiency repair. PMID:23847811

  14. Usefulness and limits of biological dosimetry based on cytogenetic methods.

    PubMed

    Léonard, A; Rueff, J; Gerber, G B; Léonard, E D

    2005-01-01

    Damage from occupational or accidental exposure to ionising radiation is often assessed by monitoring chromosome aberrations in peripheral blood lymphocytes, and these procedures have, in several cases, assisted physicians in the management of irradiated persons. Thereby, circulating lymphocytes, which are in the G0 stage of the cell cycle are stimulated with a mitogenic agent, usually phytohaemagglutinin, to replicate in vitro their DNA and enter cell division, and are then observed for abnormalities. Comparison with dose-response relationships obtained in vitro allows an estimate of exposure based on scoring: Unstable aberrations by the conventional, well-established analysis of metaphases for chromosome abnormalities or for micronuclei; So-called stable aberrations by the classical G-banding (Giemsa-Stain-banding) technique or by the more recently developed fluorescent in situ hybridisation (FISH) method using fluorescent-labelled probes for centromeres and chromosomes. Three factors need to be considered in applying such biological dosimetry: (1) Radiation doses in the body are often inhomogeneous. A comparison of the distribution of the observed aberrations among cells with that expected from a normal poisson distribution can allow conclusions to be made with regard to the inhomogeneity of exposure by means of the so-called contaminated poisson distribution method; however, its application requires a sufficiently large number of aberrations, i.e. an exposure to a rather large dose at a high dose rate. (2) Exposure can occur at a low dose rate (e.g. from spread or lost radioactive sources) rendering a comparison with in vitro exposure hazardous. Dose-effect relationships of most aberrations that were scored, such as translocations, follow a square law. Repair intervening during exposure reduces the quadratic component with decreasing dose rate as exposure is spread over a longer period of time. No valid solution for this problem has yet been developed, although

  15. A comparative study of phytohaemagglutinin and extract of Phaseolus vulgaris seeds by characterization and cytogenetics

    NASA Astrophysics Data System (ADS)

    Badari Nath, A. R. S.; Sivaramakrishna, A.; Marimuthu, K. M.; Saraswathy, Radha

    2015-01-01

    Phytohaemagglutinin (PHA) is a lectin obtained from Phaseolus vulgaris (red kidney beans), that acts as a mitogen in human leucocyte culture and is commercially available from Gibco®. This PHA (Gibco®) was found to be very expensive, hence other inexpensive sources that can be used in all kinds of cytogenetics labs (rich and poor), were attempted. One such successful attempt was PHA extract from seeds of P.vulgaris. This paper details the methodology of extraction and application of PHA from seeds of P.vulgaris. Attempts has been made to identify the chemical and physical properties of the products in the extract, analyzed by various spectroscopic and analytical techniques. The analysis clearly indicates that the product from Phaseolus seeds extract was found to be similar to the commercially available PHA (Gibco®) in the cytogenetic study of human leucocyte cultures. The present study enforces the possible utility of the plant extract directly for human leucocyte cultures.

  16. A comparative study of phytohaemagglutinin and extract of Phaseolus vulgaris seeds by characterization and cytogenetics.

    PubMed

    Badari Nath, A R S; Sivaramakrishna, A; Marimuthu, K M; Saraswathy, Radha

    2015-01-01

    Phytohaemagglutinin (PHA) is a lectin obtained from Phaseolus vulgaris (red kidney beans), that acts as a mitogen in human leucocyte culture and is commercially available from Gibco. This PHA (Gibco) was found to be very expensive, hence other inexpensive sources that can be used in all kinds of cytogenetics labs (rich and poor), were attempted. One such successful attempt was PHA extract from seeds of P.vulgaris. This paper details the methodology of extraction and application of PHA from seeds of P.vulgaris. Attempts has been made to identify the chemical and physical properties of the products in the extract, analyzed by various spectroscopic and analytical techniques. The analysis clearly indicates that the product from Phaseolus seeds extract was found to be similar to the commercially available PHA (Gibco) in the cytogenetic study of human leucocyte cultures. The present study enforces the possible utility of the plant extract directly for human leucocyte cultures. PMID:25004904

  17. Cytogenetic effects of alachlor and/or atrazine in vivo and in vitro

    SciTech Connect

    Meisner, L.F.; Roloff, B.D. ); Belluck, D.A. )

    1992-01-01

    The purpose of this study was to assess the cytogenetic effects of two commonly used herbicides, alachlor and atrazine, which are often found together in groundwater. Chromosome damage was examined in bone marrow cells of mice drinking water containing 20 ppm alachlor and/or 20 ppm atrazine, with an immunosuppressive dose of cyclophosphamide used as a positive control. Chromosome damage was also quantified in human lymphocytes. The in vitro study demonstrated dose related cytogenetic damage not associated with mitotic inhibition or cell death, with damage due to the alachlor-atrazine combination suggesting an additive model. The fact that the elevated mitotic index was associated with immune suppresion in the cyclophosphamide group suggests that death of cells with accumulated chromosomal aberrations resulted in increased bone marrow proliferation, so a higher fraction of cells examined were newer with less damage.

  18. Clinical, cytogenetic and molecular study of a case of ring chromosome 10.

    PubMed

    Čiuladaitė, Živilė; Burnytė, Birutė; Vansevičiūtė, Danutė; Dagytė, Evelina; Kučinskas, Vaidutis; Utkus, Algirdas

    2015-01-01

    Ring chromosome 10 is a rare cytogenetic finding. Only a few cases with molecular cytogenetic definition have been reported. We report here on a child with a ring chromosome 10, which is associated with prenatal and postnatal growth retardation, microcephaly, dysmorphic features, hypotonia, heart defect, severe pes equinovarus, and bronchial asthma. The chromosomal aberration was defined by chromosome microarray analysis, which revealed two deletions at 10pter (3.68 Mb) and 10qter (4.26 Mb). The clinical features are very similar to those reported in other clinical cases with ring chromosome 10, excluding bronchial asthma, which has not been previously reported in individuals with ring chromosome 10. PMID:25922618

  19. Comparative Cytogenetic Study on the Toxicity of Magnetite and Zinc Ferrite Nanoparticles in Sunflower Root Cells

    NASA Astrophysics Data System (ADS)

    Foca-nici, Ecaterina; Capraru, Gabriela; Creanga, Dorina

    2010-12-01

    In this experimental study the authors present their results regarding the cellular division rate and the percentage of chromosomal aberrations in the root meristematic cells of Helianthus annuus cultivated in the presence of different volume fractions of magnetic nanoparticle suspensions, ranging between 20 and 100 microl/l. The aqueous magnetic colloids were prepared from chemically co-precipitated ferrites coated in sodium oleate. Tissue samples from the root meristeme of 2-3 day old germinated seeds were taken to prepare microscope slides following Squash method combined with Fuelgen techniques. Microscope investigation (cytogenetic tests) has resulted in the evaluation of mitotic index and chromosomal aberration index that appeared diminished and respectively increased following the addition of magnetic nanoparticles in the culture medium of the young seedlings. Zinc ferrite toxic influence appeared to be higher than that of magnetite, according to both cytogenetic parameters.

  20. Cytogenetic Status of Meloidogyne (Hypsoperine) spartinae in Relation to Other Meloidogyne Species.

    PubMed

    Triantaphyllou, A C

    1987-01-01

    Four populations of Meloidogyne spartinae from the coast of North and South Carolina were identical cytogenetically. Fourteen rod-shaped chromosomes were present in oogonia and spermatogonia, whereas seven bivalents were observed in oocytes and spermatocytes. There were no distinguishable sex chromosomes. Chromosome behavior was similar to that of other Meloidogyne species. A slight deviation in morphology of prometaphase bivalents was attributed to an increase in frequency of chiasmata that may be associated with the obligatorily amphimictic reproduction of this nematode. The anatomy of the oviduct-spermatotheca region and most cytogenetic features studied suggested that M. spartinae can be regarded as a root-knot nematode. Its position in the genus Meloidogyne or Hypsoperine can be decided by taxonomists. Its small chromosome number (n = 7) compared to the larger number (n = 13-19) of other Meloidogyne species suggests that, cytologically, M. spartinae stands closer to the ancestral form from which the prescent day root-knot nematodes have evolved. PMID:19290099

  1. Isochromosome X mosaicism in a child with Kabuki syndrome phenotype: A rare cytogenetic association

    PubMed Central

    Kumar, Jeevan M.; Gowrishankar, Kalpana; Vasanthi, T.; Kumar, R. Ashok; Jayasudha, T.

    2011-01-01

    Isochromosome is a structurally unbalanced chromosome consisting of two short arms or two long arms, which are derived by abnormal centromere division or sister-chromatid exchange. Most autosomal isochromosomes are unusual, while those involving sex chromosomes are common. Kabuki syndrome (KS, OMIM 147920) is a multiple malformation/mental retardation syndrome of unknown etiology. A conventional cytogenetic study on lymphocytes from a 4-year-old girl with physical features suggestive of KS was found to have mosaicism for isochromosome for the long arm of the X. Although most manifestations present in this patient have been described before, this report is a rare association of clinical and cytogenetic findings in this syndrome. A genome-wide analysis and a larger number of patient groups studied could improve our understanding of the genetic basis of KS. PMID:22346002

  2. Cytogenetic study of spontaneous abortions by transabdominal villus sampling and direct analysis of villi.

    PubMed

    Sánchez, J M; Franzi, L; Collia, F; De Díaz, S L; Panal, M; Dubner, M

    1999-07-01

    We report our experience in a cytogenetic study of 93 spontaneous abortions. Specimens were obtained by transabdominal chorionic villus sampling (TACVS) in women requesting prenatal diagnosis by chorionic villus sampling (CVS) but in whom an arrested pregnancy had been diagnosed during the ultrasound examination. Our success rate, i.e. the percentage of cases where we obtained results, was 91. 4 per cent, and the rate of abnormalities-mostly aneuploidies and polyploidies-was 62.3 per cent. In normal cases, masculine:feminine ratio was 1:1. These results confirm those obtained by other groups earlier this decade and allow us to conclude that, for the cytogenetic study of spontaneous abortions, CVS is a better approach than the culture of the products of conception after evacuation, because the success rate is higher and because it provides certainty that the specimens obtained are of fetal origin. PMID:10419605

  3. Scalp repair using tissue expanders.

    PubMed

    Mangubat, E Antonio

    2013-08-01

    Repair of scalp defects is often challenging, because without careful planning, excision of the defect may leave unsatisfactory cosmesis. Contemporary techniques in hair restoration surgery allow creation of natural and undetectable results, but these techniques are often unsuitable for repairing large scarred areas of hair loss. However, by using older techniques of scalp reduction and tissue expansion, excision of many large scarring defects can be accomplished. Combining older methods with modern hair restoration surgery permits the satisfactory treatment of many previously untreatable conditions. This article focuses on tissue expansion as an adjunct to repairing large scalp defects. PMID:24017990

  4. [Gonadal dysgenesis--possible variation of clinical, hormonal, cytogenetic and histologic findings].

    PubMed

    Schwanitz, G; Tietze, H U; Zerres, K; Schaaff, A

    1983-01-01

    Errors of gonadal differentiation are influencing the sex differentiation on the whole in man. Since the methods in clinical cytogenetics improved, an exact chromosome investigation became possible, which enables the necessary therapy, the appropriate medical and psychological care, and the genetic counselling. Regarding our own observations, general surveys on the frequencies of the different syndromes and on the occurrence of the single clinical symptoms are given. PMID:6656171

  5. Modification of cytogenetic and physiological effects of space flight factors by biologically active compounds

    NASA Technical Reports Server (NTRS)

    Aliyev, A. A.; Mekhti-Zade, E. R.; Mashinskiy, A. L.; Alekperov, U. K.

    1986-01-01

    Physiological and cytogenetic changes in the Welsh onion plants induced by a short (82 days) and long term (522 days) space flight are expressed in decrease of seed germination, inhibition of stem growth, depression of cell division in root meristem, and increase in the number of structural chromosome rearrangements. The treatment of such plants with solutions of a-tocopherol, auxin, and kinetin decreased the level of chromosome aberrations to the control one and normalized cell divisions and growth partly or completely.

  6. [Cytogenetic study of a case of Fanconi's syndrome with a familial pericentric inversion].

    PubMed

    Crippa, L; Ferrier, S

    1975-03-01

    The cytogenetic study of a case of Fanconi syndrome in a 16-year-old boy revealed besides chromosomal breakages, quadriradials and dicentric chromosomes, a pericentric inversion of chromosome No. 1. An uncle and an aunt on the paternal side presented likewise this pericentric inversion, however without breakages or clinical signs of Fanconi syndrome. Another paternal aunt showed short thumbs, but without chromosomal anomalies. The authors point to possible genetic repercussions of this familial pericentric inversion. PMID:1165481

  7. Comparative cytogenetics among populations of Astyanax altiparanae (Characiformes, Characidae, Incertae sedis).

    PubMed

    Ferreira, Maressa; Vicari, Marcelo Ricardo; de Camargo, Edemar Furquim; Artoni, Roberto Ferreira; Moreira-Filho, Orlando

    2009-10-01

    Cytogenetic data are presented for Astyanax altiparanae populations from three Brazilian hydrographic systems. The chromosomal data obtained in A. altiparanae support the hypothesis of diploid number conservation. However, small differences in the karyotype formula and number of nucleolar organizer regions were observed in these populations. The apparent karyotypical similarity among the studied populations strongly suggests a close relationship among them with some chromosomal divergences due to gene flow restriction. PMID:21637456

  8. Transcription-coupled and global genome repair in the Saccharomyces cerevisiae RPB2 gene at nucleotide resolution.

    PubMed Central

    Tijsterman, M; Tasseron-de Jong, J G; van de Putte, P; Brouwer, J

    1996-01-01

    Repair of UV-induced cyclobutane pyrimidine dimers (CPDs) was examined at single nucleotide resolution in the yeast Saccharomyces cerevisiae, using an improved protocol for genomic end-labelling. To obtain the sensitivity required for adduct detection in yeast, an oligonucleotide-directed enrichment step was introduced into the current methodology developed for adduct detection in Escherichia coli. With this method, heterogeneous repair of CPDs within the RPB2 locus is observed. Individual CPDs positioned in the transcribed strand are removed very efficiently with identical kinetics. This fast repair starts within 23 bases downstream of the transcription initiation site. The non-transcribed strand of the active gene exhibits slow repair without detectable repair variations between individual lesions. In contrast, CPDs positioned in the promoter region show profound repair heterogeneity. Here, CPDs at specific sites are removed very quickly, with comparable rates to CPDs positioned in the transcribed strand, while at other positions lesions are not repaired at all during the period studied. Interestingly, the fast repair in the promoter region is dependent on the RAD7 and RAD16 genes, as are the slowly repaired CPDs in this region and in the non-transcribed strand. This indicates that the global genome repair pathway is not intrinsically slow and at specific positions can be as efficient as the transcription-coupled repair pathway. PMID:8836174

  9. Injection repair of carbon fiber/bismaleimide composite panels with bisphenol E cyanate ester resin

    SciTech Connect

    Thunga, Mahendra; Bauer, Amy; Obusek, Kristine; Meilunas, Ray; Akinc, Mufit; Kessler, Michael R

    2014-08-01

    Resin injection of bisphenol E cyanate ester, a low viscosity resin that cures into a high temperature thermoset polymer, is investigated as a reliable repair method to restore strength and stiffness in delaminated carbon fiber/bismaleimide composites used in aircraft panels. The influence of temperature on the viscosity of the uncured resin was measured to optimize the injection conditions for high resin infiltration into the delaminations. The repair efficiency of the resin was evaluated by varying the panel thickness and the method by which the delamination damage was created in the composite specimens. Ultrasonic scanning (C-scan), flash thermography images, and cross-section analysis of repaired panels revealed excellent resin infiltration into the damaged region. Evaluation of mechanical repair efficiency using both bending stiffness and in-plain compressive strength of the composite panels as the repair metrics showed values exceeding 100%.

  10. Describing Sequencing Results of Structural Chromosome Rearrangements with a Suggested Next-Generation Cytogenetic Nomenclature

    PubMed Central

    Ordulu, Zehra; Wong, Kristen E.; Currall, Benjamin B.; Ivanov, Andrew R.; Pereira, Shahrin; Althari, Sara; Gusella, James F.; Talkowski, Michael E.; Morton, Cynthia C.

    2014-01-01

    With recent rapid advances in genomic technologies, precise delineation of structural chromosome rearrangements at the nucleotide level is becoming increasingly feasible. In this era of “next-generation cytogenetics” (i.e., an integration of traditional cytogenetic techniques and next-generation sequencing), a consensus nomenclature is essential for accurate communication and data sharing. Currently, nomenclature for describing the sequencing data of these aberrations is lacking. Herein, we present a system called Next-Gen Cytogenetic Nomenclature, which is concordant with the International System for Human Cytogenetic Nomenclature (2013). This system starts with the alignment of rearrangement sequences by BLAT or BLAST (alignment tools) and arrives at a concise and detailed description of chromosomal changes. To facilitate usage and implementation of this nomenclature, we are developing a program designated BLA(S)T Output Sequence Tool of Nomenclature (BOSToN), a demonstrative version of which is accessible online. A standardized characterization of structural chromosomal rearrangements is essential both for research analyses and for application in the clinical setting. PMID:24746958

  11. Atlas of genetics and cytogenetics in oncology and haematology in 2013.

    PubMed

    Huret, Jean-Loup; Ahmad, Mohammad; Arsaban, Mélanie; Bernheim, Alain; Cigna, Jérémy; Desangles, François; Guignard, Jean-Christophe; Jacquemot-Perbal, Marie-Christine; Labarussias, Maureen; Leberre, Vanessa; Malo, Anne; Morel-Pair, Catherine; Mossafa, Hossein; Potier, Jean-Claude; Texier, Guillaume; Viguié, Franck; Yau Chun Wan-Senon, Sylvie; Zasadzinski, Alain; Dessen, Philippe

    2013-01-01

    The Atlas of Genetics and Cytogenetics in Oncology and Haematology (http://AtlasGeneticsOncology.org) is a peer-reviewed internet journal/encyclopaedia/database focused on genes implicated in cancer, cytogenetics and clinical entities in cancer and cancer-prone hereditary diseases. The main goal of the Atlas is to provide review articles that describe complementary topics, namely, genes, genetic abnormalities, histopathology, clinical diagnoses and a large iconography. This description, which was historically based on karyotypic abnormalities and in situ hybridization (fluorescence in situ hybridization) techniques, now benefits from comparative genomic hybridization and massive sequencing, uncovering a tremendous amount of genetic rearrangements. As the Atlas combines different types of information (genes, genetic abnormalities, histopathology, clinical diagnoses and external links), its content is currently unique. The Atlas is a cognitive tool for fundamental and clinical research and has developed into an encyclopaedic work. In clinical practice, it contributes to the cytogenetic diagnosis and may guide treatment decision making, particularly regarding rare diseases (because they are numerous and are frequently encountered). Readers as well as the authors of the Atlas are researchers and/or clinicians. PMID:23161685

  12. Integration of the cytogenetic and genetic linkage maps of Brassica oleracea.

    PubMed Central

    Howell, Elaine C; Barker, Guy C; Jones, Gareth H; Kearsey, Michael J; King, Graham J; Kop, Erik P; Ryder, Carol D; Teakle, Graham R; Vicente, Joana G; Armstrong, Susan J

    2002-01-01

    We have assigned all nine linkage groups of a Brassica oleracea genetic map to each of the nine chromosomes of the karyotype derived from mitotic metaphase spreads of the B. oleracea var. alboglabra line A12DHd using FISH. The majority of probes were BACs, with A12DHd DNA inserts, which give clear, reliable FISH signals. We have added nine markers to the existing integrated linkage map, distributed over six linkage groups. BACs were definitively assigned to linkage map positions through development of locus-specific PCR assays. Integration of the cytogenetic and genetic linkage maps was achieved with 22 probes representing 19 loci. Four chromosomes (2, 4, 7, and 9) are in the same orientation as their respective linkage groups (O4, O7, O8, and O6) whereas four chromosomes (1, 3, 5, and 8) and linkage groups (O3, O9, O2, and O1) are in the opposite orientation. The remaining chromosome (6) is probably in the opposite orientation. The cytogenetic map is an important resource for locating probes with unknown genetic map positions and is also being used to analyze the relationships between genetic and cytogenetic maps. PMID:12136025

  13. Clinical and Molecular Cytogenetic Characterisation of Children with Developmental Delay and Dysmorphic Features

    PubMed Central

    BERTOK, Sara; ŽERJAV TANŠEK, Mojca; KOTNIK, Primož; BATTELINO, Tadej; VOLK, Marija; PECILE, Vanna; CLEVA, Lisa; GASPARINI, Paolo; KOVAČ, Jernej; HOVNIK, Tinka

    2015-01-01

    Introduction Developmental delay and dysmorphic features affect 1 – 3 % of paediatric population. In the last few years molecular cytogenetic high resolution techniques (comparative genomic hybridization arrays and single-nucleotide polymorphism arrays) have been proven to be a first-tier choice for clinical diagnostics of developmental delay and dysmorphic features. Methods and results In the present article we describe the clinical advantages of molecular cytogenetic approach (comparative genomic hybridization arrays and single nucleotide polymorphism arrays) in the diagnostic procedure of two children with developmental delay, dysmorphic features and additional morphological phenotypes. Additionally, we demonstrate the necessity of fluorescent in situ hybridization utilisation to identify the localisation and underlying mechanism of detected chromosomal rearrangement. Conclusions Two types of chromosomal abnormalities were identified and confirmed using different molecular genetic approaches. Comparative genomic hybridization arrays and single nucleotide polymorphism arrays are hereby presented as important methods to identify chromosomal imbalances in patients with developmental delay and dysmorphic features. We emphasize the importance of molecular genetic testing in patients’ parents for the demonstration of the origin and clinical importance of the aberrations prior determined in the patients. The results obtained using molecular cytogenetic high resolution techniques methods are the cornerstone for proper genetic counselling to the affected families.

  14. Comparison of DNA probe and cytogenetic methods for identifying field collected Anopheles gambiae complex mosquitoes.

    PubMed

    Collins, F H; Petrarca, V; Mpofu, S; Brandling-Bennett, A D; Were, J B; Rasmussen, M O; Finnerty, V

    1988-12-01

    A recently developed DNA probe method was compared with the standard cytogenetic method for identifying the species of individual mosquitoes in the Anopheles gambiae complex. The complex consists of 6 morphologically indistinguishable sibling species that include the major African malaria vectors. Half-gravid, field collected mosquitoes were split into 2 portions: the abdomen was preserved for ovarian nurse cell cytotaxonomy and the head/thorax portion was desiccated for DNA extraction. Cytogenetic examination of the Kenya specimens showed 88 An. gambiae and 108 An. arabiensis. The Zimbabwe specimens consisted of 6 An. gambiae and 55 An. Quadriannulatus. All samples of the 3 species were polymorphic for the major chromosomal inversions previously recorded in field specimens from eastern and southern Africa, indicating that the collections reflected natural levels of intraspecific variation in the field populations sampled. Approximately 97% of the cytologically identified mosquitoes were also identified to species by the DNA probe method, and in every case the DNA probe and cytogenetic methods of species identification produced concordant results. PMID:3207175

  15. Cytogenetics of the Brazilian Bolitoglossa paraensis (Unterstein, 1930) salamanders (Caudata, Plethodontidae)

    PubMed Central

    da Silva, Jéssica Barata; Suárez, Pablo; Nagamachi, Cleusa Yoshiko; Carter, Timothy Frederick; Pieczarka, Julio Cesar

    2014-01-01

    Plethodontid salamanders of genus Bolitoglossa constitute the largest and most diverse group of salamanders, including around 20% of living caudate species. Recent studies have indicated the occurrence of five recognized species in the Brazilian Amazon Rainforest. We present here the first cytogenetic data of a Brazilian salamander, which may prove to be a useful by contribution to the cytotaxonomy of the genus. Specimens were collected near the “type” locality (Utinga, Belém, PA, Brazil). Chromosomal preparations from duodenal epithelial cells and testes were subjected to Giemsa staining, C-banding and DAPI/CMA3 fluorochrome staining. All specimens showed a karyotype with 13 bi-armed chromosome pairs (2n = 26). Nucleolar Organizer Regions, evidenced by CMA3, were located distally on the long arm of pair 7 (7q). DAPI+ heterochromatin was predominantly centromeric, with some small pericentromeric bands. Although the C-banding patterns of other Bolitoglossa species are so far unknown, cytogenetic studies conducted in other Plethodontid salamanders have demonstrated that pericentromeric heterochromatin is a useful cytological marker for identifying interspecific homeologies. Species diversification is usually accompanied by chromosomal changes. Therefore, the cytogenetic characterization of Bolitoglossa populations from the middle and western Brazilian Amazon Basin could identify differences which may lead to the identification of new species. PMID:25249775

  16. Cytogenetics of the Brazilian Bolitoglossa paraensis (Unterstein, 1930) salamanders (Caudata, Plethodontidae).

    PubMed

    da Silva, Jéssica Barata; Suárez, Pablo; Nagamachi, Cleusa Yoshiko; Carter, Timothy Frederick; Pieczarka, Julio Cesar

    2014-09-01

    Plethodontid salamanders of genus Bolitoglossa constitute the largest and most diverse group of salamanders, including around 20% of living caudate species. Recent studies have indicated the occurrence of five recognized species in the Brazilian Amazon Rainforest. We present here the first cytogenetic data of a Brazilian salamander, which may prove to be a useful by contribution to the cytotaxonomy of the genus. Specimens were collected near the "type" locality (Utinga, Belém, PA, Brazil). Chromosomal preparations from duodenal epithelial cells and testes were subjected to Giemsa staining, C-banding and DAPI/CMA3 fluorochrome staining. All specimens showed a karyotype with 13 bi-armed chromosome pairs (2n = 26). Nucleolar Organizer Regions, evidenced by CMA3, were located distally on the long arm of pair 7 (7q). DAPI+ heterochromatin was predominantly centromeric, with some small pericentromeric bands. Although the C-banding patterns of other Bolitoglossa species are so far unknown, cytogenetic studies conducted in other Plethodontid salamanders have demonstrated that pericentromeric heterochromatin is a useful cytological marker for identifying interspecific homeologies. Species diversification is usually accompanied by chromosomal changes. Therefore, the cytogenetic characterization of Bolitoglossa populations from the middle and western Brazilian Amazon Basin could identify differences which may lead to the identification of new species. PMID:25249775

  17. Cytogenetic analyses of two Curimatidae species (Pisces; Characiformes) from the Paranapanema and Tietê Rivers.

    PubMed

    De Rosa, L V S; Foresti, F; Martins, C; Oliveira, C; Sobrinho, P E; Wasko, A P

    2007-05-01

    Cytogenetic analyses were performed in two Curimatidae species (Steindachnerina insculpta and Cyphocharax modesta) from the Paranapanema and Tietê Rivers (São Paulo State, Brazil), showing a karyotype composed of 54 meta-submetacentric chromosomes in both species. Silver- and chromomycyn-staining and fluorescent in situ hybridization (FISH) using a 18S rDNA probe indicated that the nucleolar organizer regions (NORs) of both species are localized in the terminal region of the long arm of two metacentric chromosomes. Although a single NOR system was evidenced in both analyzed species, S. insculpta and C. modesta presented the nucleolar organizer regions in distinct chromosome pairs, indicating that these cistrons can be considered cytogenetic markers. Variation on the amount and distribution of the constitutive heterochromatin (C-bands) could also be detected between the two species - while S. insculpta presented few heterochromatic blocks, intensely stained C-bands were evidenced in C. modesta specially in the terminal region of the long arm of the NOR-bearing chromosomes. Although most Curimatidae species have been characterized by homogeneous karyotypes, isolated populations could be established under different environmental conditions leading to karyotype micro-structure variations specially related to the NORs localization and C-banding distribution. The obtained data were useful for the cytogenetic characterization and differentiation of S. insculpta and C. modesta and could be used in evolutionary inferences in the Curimatidae group. PMID:17876445

  18. Definition of the zebrafish genome using flow cytometry and cytogenetic mapping

    PubMed Central

    Freeman, Jennifer L; Adeniyi, Adeola; Banerjee, Ruby; Dallaire, Stephanie; Maguire, Sean F; Chi, Jianxiang; Ng, Bee Ling; Zepeda, Cinthya; Scott, Carol E; Humphray, Sean; Rogers, Jane; Zhou, Yi; Zon, Leonard I; Carter, Nigel P; Yang, Fengtang; Lee, Charles

    2007-01-01

    Background The zebrafish (Danio rerio) is an important vertebrate model organism system for biomedical research. The syntenic conservation between the zebrafish and human genome allows one to investigate the function of human genes using the zebrafish model. To facilitate analysis of the zebrafish genome, genetic maps have been constructed and sequence annotation of a reference zebrafish genome is ongoing. However, the duplicative nature of teleost genomes, including the zebrafish, complicates accurate assembly and annotation of a representative genome sequence. Cytogenetic approaches provide "anchors" that can be integrated with accumulating genomic data. Results Here, we cytogenetically define the zebrafish genome by first estimating the size of each linkage group (LG) chromosome using flow cytometry, followed by the cytogenetic mapping of 575 bacterial artificial chromosome (BAC) clones onto metaphase chromosomes. Of the 575 BAC clones, 544 clones localized to apparently unique chromosomal locations. 93.8% of these clones were assigned to a specific LG chromosome location using fluorescence in situ hybridization (FISH) and compared to the LG chromosome assignment reported in the zebrafish genome databases. Thirty-one BAC clones localized to multiple chromosomal locations in several different hybridization patterns. From these data, a refined second generation probe panel for each LG chromosome was also constructed. Conclusion The chromosomal mapping of the 575 large-insert DNA clones allows for these clones to be integrated into existing zebrafish mapping data. An accurately annotated zebrafish reference genome serves as a valuable resource for investigating the molecular basis of human diseases using zebrafish mutant models. PMID:17597531

  19. Molecular cytogenetic analyses of Epinephelus bruneus and Epinephelus moara (Perciformes, Epinephelidae).

    PubMed

    Guo, Minglan; Wang, Shifeng; Su, Yongquan; Zhou, Yongcan; Liu, Min; Wang, Jun

    2014-01-01

    Genus Epinephelus (Perciformes, Epinephelidae), commonly known as groupers, are usually difficult in species identification for the lack and/or change of morphological specialization. In this study, molecular cytogenetic analyses were firstly performed to identify the closely related species Epinephelus bruneus and E. moara in this genus. The species-specific differences of both fish species showed in karyotype, chromosomal distribution of nucleolar organizer regions (NORs) and localization of 18S rDNA. The heterochromatin (interstitial C-bands) and distribution pattern of telomere (TTAGGG) n in E. bruneus revealed the chromosomal rearrangements and different karyotypic evolutionary characteristics compared to those in E. moara. The cytogenetic data suggested that the lineages of E. bruneus and E. moara were recently derived within the genus Epinephelus, and E. moara exhibited more plesiomorphic features than E. bruneus. All results confirmed that E. moara, which has long been considered a synonym of E. bruneus, is a distinct species in the family Epinephelidae. In addition, molecular cytogenetic analyses are useful in species differentiation and phylogenetic reconstruction in groupers. PMID:24949234

  20. Informatics Enhanced SNP Microarray Analysis of 30 Miscarriage Samples Compared to Routine Cytogenetics

    PubMed Central

    Lathi, Ruth B.; Loring, Megan; Massie, Jamie A. M.; Demko, Zachary P.; Johnson, David; Sigurjonsson, Styrmir; Gemelos, George; Rabinowitz, Matthew

    2012-01-01

    Purpose The metaphase karyotype is often used as a diagnostic tool in the setting of early miscarriage; however this technique has several limitations. We evaluate a new technique for karyotyping that uses single nucleotide polymorphism microarrays (SNP). This technique was compared in a blinded, prospective fashion, to the traditional metaphase karyotype. Methods Patients undergoing dilation and curettage for first trimester miscarriage between February and August 2010 were enrolled. Samples of chorionic villi were equally divided and sent for microarray testing in parallel with routine cytogenetic testing. Results Thirty samples were analyzed, with only four discordant results. Discordant results occurred when the entire genome was duplicated or when a balanced rearrangement was present. Cytogenetic karyotyping took an average of 29 days while microarray-based karytoyping took an average of 12 days. Conclusions Molecular karyotyping of POC after missed abortion using SNP microarray analysis allows for the ability to detect maternal cell contamination and provides rapid results with good concordance to standard cytogenetic analysis. PMID:22403611

  1. Repair of webbed fingers - slideshow

    MedlinePlus

    ... gov/ency/presentations/100096.htm Repair of webbed fingers - series—Normal anatomy To use the sharing features ... Health Solutions, Ebix, Inc. Related MedlinePlus Health Topics Finger Injuries and Disorders A.D.A.M., Inc. ...

  2. Cleft lip and palate repair

    MedlinePlus

    Orofacial cleft; Craniofacial birth defect repair; Cheiloplasty; Cleft rhinoplasty; Palatoplasty; Tip rhinoplasty ... A cleft lip is a birth defect: A cleft lip may be just a small notch in the lip. It may also be a complete split in the ...

  3. Rotator cuff repair - series (image)

    MedlinePlus

    ... shoulder and arm bones. The tendons can be torn from overuse or injury. ... Surgery to repair a torn rotator cuff is usually very successful at relieving pain in the shoulder. The procedure is less predictable at returning strength ...

  4. Precision Instrument and Equipment Repairers.

    ERIC Educational Resources Information Center

    Wyatt, Ian

    2001-01-01

    Explains the job of precision instrument and equipment repairers, who work on cameras, medical equipment, musical instruments, watches and clocks, and industrial measuring devices. Discusses duties, working conditions, employment and earnings, job outlook, and skills and training. (JOW)

  5. Anterior Repair with Processed Dermis

    MedlinePlus Videos and Cool Tools

    Anterior Repair with Axis® Tutoplast® Processed Dermis and Digitex® - Performed by Dr. Manish Patel Click Here to view the BroadcastMed, Inc. Privacy Policy and Legal Notice © 2016 BroadcastMed, Inc. ...

  6. Mammalian DNA Repair. Final Report

    SciTech Connect

    2003-01-24

    The Gordon Research Conference (GRC) on Mammalian DNA Repair was held at Harbortown Resort, Ventura Beach, CA. Emphasis was placed on current unpublished research and discussion of the future target areas in this field.

  7. 46 CFR Sec. 19 - Ship Repair Summaries.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 8 2012-10-01 2012-10-01 false Ship Repair Summaries. Sec. 19 Section 19 Shipping... Sec. 19 Ship Repair Summaries. (a) Ship Repair Summaries shall be prepared on Form MA-159 by the... jurisdiction and submitted to the District Ship Repair and Maintenance office involved. The summaries must...

  8. 46 CFR Sec. 19 - Ship Repair Summaries.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 8 2013-10-01 2013-10-01 false Ship Repair Summaries. Sec. 19 Section 19 Shipping... Sec. 19 Ship Repair Summaries. (a) Ship Repair Summaries shall be prepared on Form MA-159 by the... jurisdiction and submitted to the District Ship Repair and Maintenance office involved. The summaries must...

  9. 46 CFR Sec. 19 - Ship Repair Summaries.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Ship Repair Summaries. Sec. 19 Section 19 Shipping... Sec. 19 Ship Repair Summaries. (a) Ship Repair Summaries shall be prepared on Form MA-159 by the... jurisdiction and submitted to the District Ship Repair and Maintenance office involved. The summaries must...

  10. 46 CFR Sec. 19 - Ship Repair Summaries.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 8 2011-10-01 2011-10-01 false Ship Repair Summaries. Sec. 19 Section 19 Shipping... Sec. 19 Ship Repair Summaries. (a) Ship Repair Summaries shall be prepared on Form MA-159 by the... jurisdiction and submitted to the District Ship Repair and Maintenance office involved. The summaries must...

  11. 46 CFR Sec. 19 - Ship Repair Summaries.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 8 2014-10-01 2014-10-01 false Ship Repair Summaries. Sec. 19 Section 19 Shipping... Sec. 19 Ship Repair Summaries. (a) Ship Repair Summaries shall be prepared on Form MA-159 by the... jurisdiction and submitted to the District Ship Repair and Maintenance office involved. The summaries must...

  12. Mitral valve repair versus replacement

    PubMed Central

    Keshavamurthy, Suresh; Gillinov, A. Marc

    2015-01-01

    Degenerative, ischemic, rheumatic and infectious (endocarditis) processes are responsible for mitral valve disease in adults. Mitral valve repair has been widely regarded as the optimal surgical procedure to treat mitral valve dysfunction of all etiologies. The supporting evidence for repair over replacement is strongest in degenerative mitral regurgitation. The aim of the present review is to summarize the data in each category of mitral insufficiency and to provide recommendations based upon this data. PMID:26309824

  13. Large steam turbine repair: A survey

    SciTech Connect

    Findlan, S.J.; Lube, B. )

    1991-07-01

    This report covers a survey taken to document the current state-of-the-art in repairs to large steam turbines. One objective was to provide information to assist utilities in making repair or replacement decisions. The survey revealed that a large number of repairs have been successfully repaired involving both mechanical and welding repair techniques. Repair techniques have been improving in recent years and are being used more frequently. No guidelines or codes exist for the repair of steam turbine components so each repair is primarily controlled by agreement between the utility, contractor and insurer. Types of repairs are reviewed in this report and in addition, the capabilities of various contractors who are currently active in providing repair service. 40 refs., 10 figs., 4 tabs.

  14. Repair Integrity and Clinical Outcomes Following Arthroscopic Rotator Cuff Repair

    PubMed Central

    Williams, Ariel A.; Mark, P.; DiVenere, Jessica Megan; Klinge, Stephen Austin; Arciero, Robert A.; Mazzocca, Augustus D.

    2016-01-01

    Objectives: To prospectively evaluate the effect of early versus delayed motion on repair integrity on 6-month postoperative magnetic resonance imaging (MRI) scans following rotator cuff repair, and to correlate repair integrity with clinical and functional outcomes. We hypothesized that repair integrity would differ between the early and delayed groups and that patients with repair failures would have worse clinical and functional outcomes. Methods: This was a prospective, randomized, single blinded clinical trial comparing an early motion (post-op day 2-3) to a delayed motion (post-op day 28) rehabilitation protocol following arthroscopic repair of isolated supraspinatus tears. All patients underwent MRI at 6 months post-operatively as part of the study protocol. A blinded board-certified and fellowship-trained orthopaedic surgeon (not part of the surgical team) reviewed operative photos and video to confirm the presence of a full thickness supraspinatus tear and to ensure an adequate and consistent repair. The same surgeon along with a blinded sports medicine fellowship-trained musculoskeletal radiologist independently reviewed all MRIs to determine whether the repair was intact at 6 months. Outcome measures were collected by independent evaluators who were also blinded to group assignment. These included the Western Ontario Rotator Cuff (WORC) index, Single Assessment Numeric Evaluation (SANE) ratings, pain scores, sling use, and physical exam data. Enrolled patients were followed at 6 weeks, 6 months, and 1 year. Results: From October 2008 to April 2012, 73 patients met all inclusion criteria and were willing to participate. 36 patients were randomized to delayed motion and 37 were randomized to early motion. The final study group at 6 months consisted of 58 study participants. Postoperative MRIs were obtained on all of these patients at 6 months regardless of whether or not they were progressing as expected. These MRIs demonstrated an overall failure rate of

  15. Adaptive Response Enzyme AlkB Preferentially Repairs 1-Methylguanine and 3-Methylthymine Adducts in Double-Stranded DNA.

    PubMed

    Chen, Fangyi; Tang, Qi; Bian, Ke; Humulock, Zachary T; Yang, Xuedong; Jost, Marco; Drennan, Catherine L; Essigmann, John M; Li, Deyu

    2016-04-18

    The AlkB protein is a repair enzyme that uses an α-ketoglutarate/Fe(II)-dependent mechanism to repair alkyl DNA adducts. AlkB has been reported to repair highly susceptible substrates, such as 1-methyladenine and 3-methylcytosine, more efficiently in ss-DNA than in ds-DNA. Here, we tested the repair of weaker AlkB substrates 1-methylguanine and 3-methylthymine and found that AlkB prefers to repair them in ds-DNA. We also discovered that AlkB and its human homologues, ABH2 and ABH3, are able to repair the aforementioned adducts when the adduct is present in a mismatched base pair. These observations demonstrate the strong adaptability of AlkB toward repairing various adducts in different environments. PMID:26919079

  16. Molecular basis for DNA strand displacement by NHEJ repair polymerases

    PubMed Central

    Bartlett, Edward J.; Brissett, Nigel C.; Plocinski, Przemyslaw; Carlberg, Tom; Doherty, Aidan J.

    2016-01-01

    The non-homologous end-joining (NHEJ) pathway repairs DNA double-strand breaks (DSBs) in all domains of life. Archaea and bacteria utilize a conserved set of multifunctional proteins in a pathway termed Archaeo-Prokaryotic (AP) NHEJ that facilitates DSB repair. Archaeal NHEJ polymerases (Pol) are capable of strand displacement synthesis, whilst filling DNA gaps or partially annealed DNA ends, which can give rise to unligatable intermediates. However, an associated NHEJ phosphoesterase (PE) resects these products to ensure that efficient ligation occurs. Here, we describe the crystal structures of these archaeal (Methanocella paludicola) NHEJ nuclease and polymerase enzymes, demonstrating their strict structural conservation with their bacterial NHEJ counterparts. Structural analysis, in conjunction with biochemical studies, has uncovered the molecular basis for DNA strand displacement synthesis in AP-NHEJ, revealing the mechanisms that enable Pol and PE to displace annealed bases to facilitate their respective roles in DSB repair. PMID:26405198

  17. Repair and enterotoxin synthesis by Staphylococcus aureus after thermal shock.

    PubMed Central

    Hernández, F J; Goyache, J; Orden, J A; Blanco, J L; Doménech, A; Suárez, G; Gómez-Lucía, E

    1993-01-01

    To study repair and enterotoxin synthesis, four staphylococcal strains (FRI-100, FRI-137, FRI-472, and S6) were subjected to sublethal heat treatment, transferred to four liquid repair media (1% powdered skim milk in distilled water, complex medium, M9 minimal salt medium, and saline solution), and then incubated at different temperatures. Powdered skim milk proved to be the most efficient medium for promoting the repair of injured cells, particularly at 37 degrees C. Minimal salt medium also gave good results. Salt tolerance also increased at 4 degrees C, although it did not reach normal values. After 6 h of incubation at 37 degrees C in powdered skim milk, strain FRI-100 synthesized detectable amounts of enterotoxin A. After 10 h of incubation in the same medium at the same temperature, enterotoxins were detected in all of the strains. PMID:8517746

  18. Molecular basis for DNA strand displacement by NHEJ repair polymerases.

    PubMed

    Bartlett, Edward J; Brissett, Nigel C; Plocinski, Przemyslaw; Carlberg, Tom; Doherty, Aidan J

    2016-03-18

    The non-homologous end-joining (NHEJ) pathway repairs DNA double-strand breaks (DSBs) in all domains of life. Archaea and bacteria utilize a conserved set of multifunctional proteins in a pathway termed Archaeo-Prokaryotic (AP) NHEJ that facilitates DSB repair. Archaeal NHEJ polymerases (Pol) are capable of strand displacement synthesis, whilst filling DNA gaps or partially annealed DNA ends, which can give rise to unligatable intermediates. However, an associated NHEJ phosphoesterase (PE) resects these products to ensure that efficient ligation occurs. Here, we describe the crystal structures of these archaeal (Methanocella paludicola) NHEJ nuclease and polymerase enzymes, demonstrating their strict structural conservation with their bacterial NHEJ counterparts. Structural analysis, in conjunction with biochemical studies, has uncovered the molecular basis for DNA strand displacement synthesis in AP-NHEJ, revealing the mechanisms that enable Pol and PE to displace annealed bases to facilitate their respective roles in DSB repair. PMID:26405198

  19. Repair of rDNA in Saccharomyces cerevisiae: RAD4-independent strand-specific nucleotide excision repair of RNA polymerase I transcribed genes.

    PubMed Central

    Verhage, R A; Van de Putte, P; Brouwer, J

    1996-01-01

    Removal of UV-induced pyrimidine dimers from the individual strands of the rDNA locus in Saccharomyces cerevisiae was studied. Yeast rDNA, that is transcribed by RNA polymerase I(RNA pol I), is repaired efficiently, slightly strand-specific and independently of RAD26, which has been implicated in transcription-coupled repair of the RNA pol II transcribed RPB2 gene. No repair of rDNA is observed in rad1,2,3 and 14 mutants, demonstrating that dimer removal from this highly repetitive DNA is accomplished by nucleotide excision repair (NER). In rad7 and rad16 mutants, which are specifically deficient in repair of non-transcribed DNA, there is a clear preferential repair of the transcribed strand of rDNA, indicating that strand-specific and therefore probably transcription-coupled repair of RNA pol I transcribed genes does exist in yeast. Unexpectedly, the transcribed but not the non-transcribed strand of rDNA can be repaired in rad4 mutants, which seem otherwise completely NER-deficient. PMID:8604332

  20. 49 CFR 1242.42 - Administration, repair and maintenance, machinery repair, equipment damaged, dismantling retired...

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 9 2010-10-01 2010-10-01 false Administration, repair and maintenance, machinery repair, equipment damaged, dismantling retired property, fringe benefits, other casualties and insurance... maintenance, machinery repair, equipment damaged, dismantling retired property, fringe benefits,...

  1. Rate of repair in minimally invasive mitral valve surgery

    PubMed Central

    Hohenberger, Wolfgang; Lakew, Fitsum; Batz, Gerhard; Diegeler, Anno

    2013-01-01

    Background Valve repair has been shown to be the method of choice in the treatment of patients with severe mitral valve regurgitation. Minimally invasive surgery has raised skepticism regarding the rate of repair especially for supposedly complex lesions, when anterior leaflet involvement or bileaflet prolapse is present. We sought to review our experience of all our patients presenting with degenerative mitral valve regurgitation and operated on minimally invasively. Method From September 2006 to December 2012, 842 patients (mean age 56.12±11.62 years old) with degenerative mitral valve regurgitation and anterior leaflet (n=82, 9.7%), posterior leaflet (n=688, 81.7%) and bileaflet (n=72, 8.6%) prolapses were operated on using a minimally invasive approach. Results 836 patients had a valve repair (99.3%) and received a concomitant ring annuloplasty (mean size, 33.7; range, 28-40). Six patients (0.7%) underwent valve replacement. Two patients had a re-repair due to MR progression or infective endocarditis. Thirty-day mortality was 0.2% (two patients). There were 60 major adverse events (MAE) (7.1%). Conclusions A minimally invasive approach allows repair of almost all degenerative valves with good short-term outcomes in a tertiary referral center, when using proven and efficient surgical techniques. PMID:24349977

  2. Maintenance of Glare Structures and Glare as Riveted or Bonded Repair Material

    NASA Astrophysics Data System (ADS)

    Woerden, H. J. M.; Sinke, J.; Hooijmeijer, P. A.

    2003-07-01

    Aircraft structures constructed from new and advanced materials will become more common in the near future, starting with the use of the Fibre Metal Laminate Glare in large parts of the Airbus A-380 fuselage. These materials are primarily used because of their excellent damage tolerance properties. However, questions about maintenance and repair of such structures need to be answered before such new materials can be used. These questions include whether new and advanced materials can be repaired in a conventional way, which would not only be preferable from the operator's point of view (no change in tools, maintenance procedures, and personnel training), but also from the manufacturer's point of view (Structural Repair Manuals similar to aluminium structures). A Glare demonstrator panel has been designed and applied to an Airbus A-310 and research into the repairability of Glare has been performed to answer these questions. Apart from looking into the repairability of Glare structures, the material itself is also investigated as material for bonded repair patches. Bonded repair many times proves to be a more viable solution than conventional riveted repair due to its more efficient load transfer. Important aspects of bonded (Glare) repair are under investigation to show that bonded patch repair is not only working for the ageing aircraft of several Air Forces around the world, but is also a promising candidate for safe and cost-effective repairs to ageing and new (incidental damage) aircraft of commercial operators. This research is conducted cooperatively by Delft University of Technology and the United States Air Force Academy and has led to two real-life repairs on a C-5A ``Galaxy''.

  3. A retrospective analysis of cytogenetic alterations in patients with newly diagnosed multiple myeloma: a single center study in Korea

    PubMed Central

    Li, Shuhua; Lim, Hyeon-Ho; Woo, Kwang-Sook; Kim, Sung-Hyun

    2016-01-01

    Background The accurate identification of cytogenetic abnormalities in multiple myeloma (MM) has become more important over recent years for the development of new diagnostic and prognostic markers. In this study, we retrospectively analyzed the cytogenetic aberrations in MM cases as an initial assessment in a single institute. Methods We reviewed the cytogenetic results from 222 patients who were newly diagnosed with MM between January 2000 and December 2015. Chromosomal analysis was performed on cultured bone marrow samples by standard G-banding technique. At least 20 metaphase cells were analyzed for karyotyping. Results Clonal chromosome abnormalities were detected in 45.0% (100/222) of the patients. Among these results, 80 cases (80.0%) had both numerical and structural chromosome abnormalities. Overall hyperdiploidy with structural cytogenetic aberrations was the most common finding (44.0%), followed by hypodiploidy with structural aberrations (28.0%). Amplification of the long arm of chromosome 1 and -13/del(13q) were the most frequent recurrent abnormalities, and were detected in 50 patients (50.0%) and 40 patients (40.0%) with clonal abnormalities, respectively. The most common abnormality involving 14q32 was t(11;14)(q13;q32), which was observed in 19 cases. Conclusion These findings demonstrate that myeloma cells exhibit complex aberrations regardless of ploidy, even from a single center in Korea. Conventional cytogenetic analysis should be included in the initial diagnostic work-up for patients suspected of having MM. PMID:27382557

  4. Comparative study of microsatellite and cytogenetic markers for detecting the origin of the nondisjoined chromosome 21 in down syndrome

    SciTech Connect

    Petersen, M.B.; Frantzen, M.; Lund, C.; Olsen, B.; Poulsen, H.; Sand, A.; Tommerup, N.; Mikkelsen, M. ); Antonarakis, S.E.; Warren, A.C. ); Van Broeckhoven, C. ); Chakravarti, A.; Cox, T.K. )

    1992-09-01

    Nondisjunction in trisomy 21 has traditionally been studied by cytogenetic heteromorphisms. Those studies assumed no crossing-over on the short arm of chromosome 21. Recently, increased accuracy of detection of the origin of nondisjunction has been demonstrated by DNA polymorphism analysis. The authors describe a comparative study of cytogenetic heteromorphisms and seven PCR-based DNA polymorphism analysis. They describe a comparative study of cytogenetic heteromorphisms and seven PCR-based DNA polymorphisms for detecting the origin of the additional chromosome 21 in 68 cases of Down syndrome. The polymorphisms studied were the highly informative microsatellites at loci D21S120, D21S192, IFNAR, D21S156, HMG14, and D21S171. The meiotic stage of nondisjunction was assigned on the basis of the pericentromeric markers D21S215, D21S120, and D21S192. Only unequivocal cytogenetic results were compared with the results of the DNA analysis. The parental and meiotic division origin could be determined in 51% of the cases by using the cytogenetic markers and in 88% of the cases by using the DNA markers. Although there were no discrepancies between the two scoring systems regarding parental origin, there were eight discrepancies regarding meiotic stage of nondisjunction. The results raise the possibility of recombination between the two marker systems, particularly on the short arm. 46 refs., 2 figs., 3 tabs.

  5. Repair of the Ankle Syndesmosis

    PubMed Central

    Backus, Jonathan D.; Clanton, Thomas O.; Whitlow, Scott R.; Williams, Brady T.; Liechti, Daniel; Dornan, Grant J.; Saroki, Adriana; Turnbull, Travis Lee; LaPrade, Robert F.

    2016-01-01

    Objectives: Significant debate exists regarding the optimal repair techniques for unstable syndesmosis injuries. Techniques range from one to multiple screw fixation, suture-button fixation devices, or a combination of the two. The purpose of the current investigation was to biomechanically compare three common syndesmotic repair techniques using a simulated weight-bearing protocol with internal and external rotation of the foot. Methods: Twenty-four, lower leg specimens with mean age 54.25 years (range, 38 to 68 years) were utilized for testing. Following the creation of a complete syndesmotic injury (AITFL, ITFL, PITFL, interosseous membrane) specimens were repaired using one of three randomly assigned repair techniques: (1) one 3.5 mm syndesmotic screw, (2) one suture-button construct, and (3) two divergent suture-button constructs. For testing, specimens were oriented in neutral plantar/dorsiflexion and neutral internal/external rotation with the respect to the vertical tibia. Repairs were then cycled for 500 cycles between 7.5 Nm of internal/external rotation torque under a constant 750 N axial compressive load. At 0, 10, 100, and 500 cycles, torsional cyclic loading was interrupted to assess torsional stiffness and resistance to rotation within a physiologic range of motion. While axially loaded to 750 N, the foot was externally rotated to 15° and then rotated to 10° of internal rotation. Torsional cyclic loading was then resumed. Torque (Nm) and rotational position (degrees) were recorded continuously throughout testing. Three-dimensional data was also collected throughout testing to characterize the relative spatial relationships of the tibiofibular articulation. Results: Biomechanically, there were no significant differences between techniques when repairs were compared to the intact syndesmosis. Three-dimensional analysis revealed significant differences between all repair techniques for sagittal fibular translation with external rotation of the foot

  6. Essentials of skin laceration repair.

    PubMed

    Forsch, Randall T

    2008-10-15

    Skin laceration repair is an important skill in family medicine. Sutures, tissue adhesives, staples, and skin-closure tapes are options in the outpatient setting. Physicians should be familiar with various suturing techniques, including simple, running, and half-buried mattress (corner) sutures. Although suturing is the preferred method for laceration repair, tissue adhesives are similar in patient satisfaction, infection rates, and scarring risk in low skin-tension areas and may be more cost-effective. The tissue adhesive hair apposition technique also is effective in repairing scalp lacerations. The sting of local anesthesia injections can be lessened by using smaller gauge needles, administering the injection slowly, and warming or buffering the solution. Studies have shown that tap water is safe to use for irrigation, that white petrolatum ointment is as effective as antibiotic ointment in postprocedure care, and that wetting the wound as early as 12 hours after repair does not increase the risk of infection. Patient education and appropriate procedural coding are important after the repair. PMID:18953970

  7. DNA repair in mammalian embryos.

    PubMed

    Jaroudi, Souraya; SenGupta, Sioban

    2007-01-01

    Mammalian cells have developed complex mechanisms to identify DNA damage and activate the required response to maintain genome integrity. Those mechanisms include DNA damage detection, DNA repair, cell cycle arrest and apoptosis which operate together to protect the conceptus from DNA damage originating either in parental gametes or in the embryo's somatic cells. DNA repair in the newly fertilized preimplantation embryo is believed to rely entirely on the oocyte's machinery (mRNAs and proteins deposited and stored prior to ovulation). DNA repair genes have been shown to be expressed in the early stages of mammalian development. The survival of the embryo necessitates that the oocyte be sufficiently equipped with maternal stored products and that embryonic gene expression commences at the correct time. A Medline based literature search was performed using the keywords 'DNA repair' and 'embryo development' or 'gametogenesis' (publication dates between 1995 and 2006). Mammalian studies which investigated gene expression were selected. Further articles were acquired from the citations in the articles obtained from the preliminary Medline search. This paper reviews mammalian DNA repair from gametogenesis to preimplantation embryos to late gestational stages. PMID:17141556

  8. Imaging of cartilage repair procedures

    PubMed Central

    Sanghvi, Darshana; Munshi, Mihir; Pardiwala, Dinshaw

    2014-01-01

    The rationale for cartilage repair is to prevent precocious osteoarthritis in untreated focal cartilage injuries in the young and middle-aged population. The gamut of surgical techniques, normal postoperative radiological appearances, and possible complications have been described. An objective method of recording the quality of repair tissue is with the magnetic resonance observation of cartilage repair tissue (MOCART) score. This scoring system evaluates nine parameters that include the extent of defect filling, border zone integration, signal intensity, quality of structure and surface, subchondral bone, subchondral lamina, and records presence or absence of synovitis and adhesions. The five common techniques of cartilage repair currently offered include bone marrow stimulation (microfracture or drilling), mosaicplasty, synthetic resorbable scaffold grafts, osteochondral allograft transplants, and autologous chondrocyte implantation (ACI). Complications of cartilage repair procedures that may be demonstrated on magnetic resonance imaging (MRI) include plug loosening, graft protuberance, graft depression, and collapse in mosaicplasty, graft hypertrophy in ACI, and immune response leading to graft rejection, which is more common with synthetic grafts and cadaveric allografts. PMID:25114387

  9. Repairing Solar Max: The Solar Maximum Repair Mission

    NASA Technical Reports Server (NTRS)

    Mcmahan, T.; Neal, V.

    1984-01-01

    Technology and procedures designed for replacing a faulty attitude control module and scientific instruments on the only orbiting solar observatory are described. The rationale for the repair mission is given and the operations of the flight support system within the cargo bay of the space shuttle are discussed. The use of the manned maneuvering unit in capturing the satellite and of the remote manipulator arm in berthing it are discussed, as well as the space tools to be used for repair operations. The space crew and their responsibilities are identified.

  10. [Studies of the repair of radiation-induced genetic damage in Drosophila]. Annual progress report, July 1, 1991--June 1, 1992

    SciTech Connect

    1992-12-31

    The primary goal of this program is to achieve a more thorough understanding of the mechanisms employed by higher organisms to resist DNA damage. Concurrently this effort contributes to an improved understanding of the processes of mutagenesis and carcinogenesis in higher eukaryotes. Drosophila was initially chosen as a model organism for investigating functions that control mutagen resistance because of the ease with which one can isolate and characterize mutagen-sensitive mutants in this multicellular organism. This laboratory then went on to investigate the DNA repair defects of such mutants while others performed complementary genetic and cytogenetic studies which relate DNA repair processes to mutagenesis and chromosome stability. Currently, recombinant DNA technology is being employed to investigate the mechanisms of mutagen resistance defined by those mutants. The following two studies experienced the most significant progress during the past year: cloning and genetic characterization of the mus209 gene, and genetic and molecular analysis of the mus308 gene.

  11. Consolidation of the genetic and cytogenetic maps of turbot (Scophthalmus maximus) using FISH with BAC clones.

    PubMed

    Taboada, Xoana; Pansonato-Alves, Jose C; Foresti, Fausto; Martínez, Paulino; Viñas, Ana; Pardo, Belén G; Bouza, Carmen

    2014-06-01

    Bacterial artificial chromosomes (BAC) have been widely used for fluorescence in situ hybridization (FISH) mapping of chromosome landmarks in different organisms, including a few in teleosts. In this study, we used BAC-FISH to consolidate the previous genetic and cytogenetic maps of the turbot (Scophthalmus maximus), a commercially important pleuronectiform. The maps consisted of 24 linkage groups (LGs) but only 22 chromosomes. All turbot LGs were assigned to specific chromosomes using BAC probes obtained from a turbot 5× genomic BAC library. It consisted of 46,080 clones with inserts of at least 100 kb and <5 % empty vectors. These BAC probes contained gene-derived or anonymous markers, most of them linked to quantitative trait loci (QTL) related to productive traits. BAC clones were mapped by FISH to unique marker-specific chromosomal positions, which showed a notable concordance with previous genetic mapping data. The two metacentric pairs were cytogenetically assigned to LG2 and LG16, and the nucleolar organizer region (NOR)-bearing pair was assigned to LG15. Double-color FISH assays enabled the consolidation of the turbot genetic map into 22 linkage groups by merging LG8 with LG18 and LG21 with LG24. In this work, a first-generation probe panel of BAC clones anchored to the turbot linkage and cytogenetical map was developed. It is a useful tool for chromosome traceability in turbot, but also relevant in the context of pleuronectiform karyotypes, which often show small hardly identifiable chromosomes. This panel will also be valuable for further integrative genomics of turbot within Pleuronectiformes and teleosts, especially for fine QTL mapping for aquaculture traits, comparative genomics, and whole-genome assembly. PMID:24473579

  12. A cytogenetic and comparative map of camelid chromosome 36 and the minute in alpacas.

    PubMed

    Avila, Felipe; Baily, Malorie P; Merriwether, David A; Trifonov, Vladimir A; Rubes, Jiři; Kutzler, Michelle A; Chowdhary, Renuka; Janečka, Jan; Raudsepp, Terje

    2015-06-01

    Recent advances in camelid genomics have provided draft sequence assemblies and the first comparative and gene maps for the dromedary (CDR) and the alpaca (LPA). However, no map information is currently available for the smallest camelid autosome-chr36. The chromosome is also of clinical interest because of its involvement in the minute chromosome syndrome (MCS) in infertile alpacas. Here, we developed molecular markers for camelid chr36 by direct sequencing CDR36 and LPA minute and by bioinformatics analysis of alpaca unplaced sequence scaffolds. We constructed a cytogenetic map for chr36 in the alpaca, llama, and dromedary and showed its homology to human chromosome 7 (HSA7) at 49.8-55.5 Mb. The chr36 map comprised seven markers, including two genes-ZPBP and WVC2. Comparative status of HSA7 was further refined by cytogenetic mapping of 16 HSA7 orthologs in camelid chromosomes 7 and 18 and by the analysis of HSA7-conserved synteny blocks across 11 vertebrate species. Finally, mapping chr36 markers in infertile alpacas confirmed that the minute chromosome was a derivative of chr36, but the small size was not a result of a large deletion or a translocation. Instead, cytogenetic mapping of 5.8S, 18S, and 28S rRNA genes (nucleolus organizer region (NOR)) revealed that the size difference between chr36 homologs in infertile alpacas was due to a heterozygous presence of NOR, whereas chr36 in fertile alpacas had no NOR. We theorized that the heterozygous NOR might affect chr36 pairing, recombination, and segregation in meiosis and, thus fertility. PMID:25634498

  13. Cytogenetic and molecular characterization of 57 individuals with the Parder-Willi syndrome

    SciTech Connect

    Butler, M.G.; Forrest, K.B.; Miller, L.K.

    1994-09-01

    Prader-Willi syndrome (PWS) is characterized by hypotonia, early childhood obesity, mental deficiency, hypogonadism and an interstitial deletion of 15q11q13 of paternal origin in 50-70% of patients. The remaining patients have either submicroscopic deletions, maternal disomy or other anomalies of chromosome 15. We have undertaken cytogenetic and molecular genetic studies of 57 individuals presenting with features consistent with PWS (28 males and 29 females; age range of 3 months to 38 years), 25 with recognizable 15q11q13 deletions (44%), 28 with normal appearing chromosomes (49%), and four patients with other chromosome 15 anomalies (7%). High resolution chromosome analysis and PCR amplification were performed utilizing 17 STRs from 15q11q13 region, quantitative Southern hybridization using seven 15q11q13 probes, and fluorescence in situ hybridization (FISH) using four 15q11q13 probes (4-3R, SNRPN, 3-21, and GABRB3). The cytogenetic deletion was paternal in all PWS families studied but the deletion varied in size in 10 patients. Parental DNA studies from 20 of 28 non-deletion patients showed maternal disomy in 7 patients and biparental inheritance in 13 non-deletion patients. In order to evaluate for submicroscopic deletions, PCR amplification with several loci in the area of the PWS minimal critical region, FISH using SNRPN and quantitative hybridization using a PCR product generated from primers of exons E and H of the SNRPN gene were undertaken on the non-deletion patients. Quantitative hybridization and FISH using SNRPN from 3 of 11 non-deletion patients (excluding maternal disomy cases) showed a submicroscopic deletion. One of these patients also showed a paternal deletion of D15S128 and MN1. We furthur support the use of both cytogenetic and molecular genetic methods for determining the genetic status of PWS patients.

  14. [Problems occurring in the application of cytogenetic biomarkers for alcoholics with and without malignant diseases].

    PubMed

    Gundy, Sarolta; Székely, Gábor; Farkas, Gyöngyi; Pulay, Attila; Remenár, Eva

    2008-06-01

    Applicability of alcohol- and smoking-related cancer-risk biomarkers might be modified by several factors. Among those, reality of self-reports on alcohol consumption of alcoholic patients with different diseases and extreme high mutagen hypersensitivity of Hungarians, as well as the immunologic role of peripheral lymphocytes as experimental objects of cytogenetic biomarkers seem to be new viewpoints of interest. To clarify these problems, 432 head and neck cancer patients (HNCP), 62 alcoholics with alcoholic hepatitis (ALCL), and 101 disease-free chronic alcoholics (ALC) were examined. Despite clinically confirmed alcohol-related diagnoses (and GGT and MCV values) only about half of HNCPs and ALCLs reported about any alcohol consumption, in contrast to the realistic self-reports of ALCs. In cytogenetic case control investigations no difference between the spontaneous rate of chromosomal aberrations (CAs) of healthy controls and ALCs was found, however, genetic instability expressed as a 40-50% elevation rate of CAs in HNCPs and ALCLs might be associated with systemic inflammatory reaction of lymphocytes. Bleomycin sensitivity assay showed the highest break/cell (b/c) values not in HNCPs (1.06 b/c) as it was reported earlier, but in "healthy" ALCs (1.52 b/c). This phenomenon can be related to the local effect of genotoxins (alcohol, smoking, and in particular the diet), which probably reflects merely a reaction of mucosal immune system. Nearly 50% of mutagen-hypersensitive Hungarian controls, in contrary to the expected 10-20% ones, might also be explained by this. Similarly, HNCPs with oral cancer, where the local mutagen effect was the most intensive, had the highest b/c values. In conclusion, when cytogenetic biomarkers of alcoholism are examined, the subjective character of self-reports at epidemiologic level and immunologic role of lymphocyte subpopulations as genetic confounders must also be taken into consideration. PMID:18640891

  15. Ozone Inhalation Leads to a Dose-Dependent Increase of Cytogenetic Damage in Human Lymphocytes

    PubMed Central

    Holland, Nina; Davé, Veronica; Venkat, Subha; Wong, Hofer; Donde, Aneesh; Balmes, John R; Arjomandi, Mehrdad

    2014-01-01

    Ozone is an important constituent of ambient air pollution and represents a major public health concern. Oxidative injury due to ozone inhalation causes the generation of reactive oxygen species and can be genotoxic. To determine whether ozone exposure causes genetic damage in peripheral blood lymphocytes, we employed a well-validated cytokinesis-block micronucleus Cytome assay. Frequencies of micronuclei (MN) and nucleoplasmic bridges (NB) were used as indicators of cytogenetic damage. Samples were obtained from 22 non-smoking healthy subjects immediately before and 24-hr after controlled 4-hr exposures to filtered air, 100 ppb, and 200 ppb ozone while exercising in a repeated-measure study design. Inhalation of ozone at different exposure levels was associated with a significant dose-dependent increase in MN frequency (P < 0.0001) and in the number of cells with more than 1 MN per cell (P < 0.0005). Inhalation of ozone also caused an increase in the number of apoptotic cells (P = 0.002). Airway neutrophilia was associated with an increase in MN frequency (P = 0.033) independent of the direct effects of ozone exposure (P < 0.0001). We also observed significant increases in both MN and NB frequencies after exercise in filtered air, suggesting that physical activity is also an important inducer of oxidative stress. These results corroborate our previous findings that cytogenetic damage is associated with ozone exposure, and show that damage is dose-dependent. Further study of ozone-induced cytogenetic damage in airway epithelial cells could provide evidence for the role of oxidative injury in lung carcinogenesis, and help to address the potential public health implications of exposures to oxidant environments. PMID:25451016

  16. Molecular cytogenetic map of the central bearded dragon, Pogona vitticeps (Squamata: Agamidae).

    PubMed

    Young, M J; O'Meally, D; Sarre, S D; Georges, A; Ezaz, T

    2013-07-01

    Reptiles, as the sister group to birds and mammals, are particularly valuable for comparative genomic studies among amniotes. The Australian central bearded dragon (Pogona vitticeps) is being developed as a reptilian model for such comparisons, with whole-genome sequencing near completion. The karyotype consists of 6 pairs of macrochromosomes and 10 pairs microchromosomes (2n = 32), including a female heterogametic ZW sex microchromosome pair. Here, we present a molecular cytogenetic map for P. vitticeps comprising 87 anchor bacterial artificial chromosome clones that together span each macro- and microchromosome. It is the first comprehensive cytogenetic map for any non-avian reptile. We identified an active nucleolus organizer region (NOR) on the sub-telomeric region of 2q by mapping 18S rDNA and Ag-NOR staining. We identified interstitial telomeric sequences in two microchromosome pairs and the W chromosome, indicating that microchromosome fusion has been a mechanism of karyotypic evolution in Australian agamids within the last 21 to 19 million years. Orthology searches against the chicken genome revealed an intrachromosomal rearrangement of P. vitticeps 1q, identified regions orthologous to chicken Z on P. vitticeps 2q, snake Z on P. vitticeps 6q and the autosomal microchromosome pair in P. vitticeps orthologous to turtle Pelodiscus sinensis ZW and lizard Anolis carolinensis XY. This cytogenetic map will be a valuable reference tool for future gene mapping studies and will provide the framework for the work currently underway to physically anchor genome sequences to chromosomes for this model Australian squamate. PMID:23703235

  17. Identification of differentially methylated markers among cytogenetic risk groups of acute myeloid leukemia.

    PubMed

    Qu, Xiaoyu; Davison, Jerry; Du, Liping; Storer, Barry; Stirewalt, Derek L; Heimfeld, Shelly; Estey, Elihu; Appelbaum, Frederick R; Fang, Min

    2015-01-01

    Aberrant DNA methylation is known to occur in cancer, including hematological malignancies such as acute myeloid leukemia (AML). However, less is known about whether specific methylation profiles characterize specific subcategories of AML. We examined this issue by using comprehensive high-throughput array-based relative methylation analysis (CHARM) to compare methylation profiles among patients in different AML cytogenetic risk groups. We found distinct profiles in each group, with the high-risk group showing overall increased methylation compared with low- and mid-risk groups. The differentially methylated regions (DMRs) distinguishing cytogenetic risk groups of AML were enriched in the CpG island shores. Specific risk-group associated DMRs were located near genes previously known to play a role in AML or other malignancies, such as MN1, UHRF1, HOXB3, and HOXB4, as well as TRIM71, the function of which in cancer is not well characterized. These findings were verified by quantitative bisulfite pyrosequencing and by comparison with results available at the TCGA cancer genome browser. To explore the potential biological significance of the observed methylation changes, we correlated our findings with gene expression data available through the TCGA database. The results showed that decreased methylation at HOXB3 and HOXB4 was associated with increased gene expression of both HOXB genes specific to the mid-risk AML, while increased DNA methylation at DCC distinctive to the high-risk AML was associated with increased gene expression. Our results suggest that the differential impact of cytogenetic changes on AML prognosis may, in part, be mediated by changes in methylation. PMID:25996682

  18. Identification of differentially methylated markers among cytogenetic risk groups of acute myeloid leukemia

    PubMed Central

    Qu, Xiaoyu; Davison, Jerry; Du, Liping; Storer, Barry; Stirewalt, Derek L; Heimfeld, Shelly; Estey, Elihu; Appelbaum, Frederick R; Fang, Min

    2015-01-01

    Aberrant DNA methylation is known to occur in cancer, including hematological malignancies such as acute myeloid leukemia (AML). However, less is known about whether specific methylation profiles characterize specific subcategories of AML. We examined this issue by using comprehensive high-throughput array-based relative methylation analysis (CHARM) to compare methylation profiles among patients in different AML cytogenetic risk groups. We found distinct profiles in each group, with the high-risk group showing overall increased methylation compared with low- and mid-risk groups. The differentially methylated regions (DMRs) distinguishing cytogenetic risk groups of AML were enriched in the CpG island shores. Specific risk-group associated DMRs were located near genes previously known to play a role in AML or other malignancies, such as MN1, UHRF1, HOXB3, and HOXB4, as well as TRIM71, the function of which in cancer is not well characterized. These findings were verified by quantitative bisulfite pyrosequencing and by comparison with results available at the TCGA cancer genome browser. To explore the potential biological significance of the observed methylation changes, we correlated our findings with gene expression data available through the TCGA database. The results showed that decreased methylation at HOXB3 and HOXB4 was associated with increased gene expression of both HOXB genes specific to the mid-risk AML, while increased DNA methylation at DCC distinctive to the high-risk AML was associated with increased gene expression. Our results suggest that the differential impact of cytogenetic changes on AML prognosis may, in part, be mediated by changes in methylation. PMID:25996682

  19. Benefit of high-dose daunorubicin in AML induction extends across cytogenetic and molecular groups.

    PubMed

    Luskin, Marlise R; Lee, Ju-Whei; Fernandez, Hugo F; Abdel-Wahab, Omar; Bennett, John M; Ketterling, Rhett P; Lazarus, Hillard M; Levine, Ross L; Litzow, Mark R; Paietta, Elisabeth M; Patel, Jay P; Racevskis, Janis; Rowe, Jacob M; Tallman, Martin S; Sun, Zhuoxin; Luger, Selina M

    2016-03-24

    The initial report of the Eastern Cooperative Oncology Group-American College of Radiology Imaging Network Cancer Research Group trial E1900 (#NCT00049517) showed that induction therapy with high-dose (HD) daunorubicin (90 mg/m(2)) improved overall survival in adults <60 years old with acute myeloid leukemia (AML); however, at initial analysis, the benefit was restricted to younger patients (<50 years) and patients without unfavorable cytogenetics or aFLT3-ITD mutation. Here, we update the results of E1900 after longer follow-up (median, 80.1 months among survivors), focusing on the benefit of HD daunorubicin on common genetic subgroups. Compared with standard-dose daunorubicin (45 mg/m(2)), HD daunorubicin is associated with a hazard ratio (HR) for death of 0.74 (P= .001). Younger patients (<50 years) benefited from HD daunorubicin (HR, 0.66;P= .002), as did patients with favorable and intermediate cytogenetics (HR, 0.51;P= .03 and HR, 0.68;P= .01, respectively). Patients with unfavorable cytogenetics were shown to benefit from HD daunorubicin on multivariable analysis (adjusted HR, 0.66;P= .04). Patients withFLT3-ITD (24%),DNMT3A(24%), andNPM1(26%) mutant AML all benefited from HD daunorubicin (HR, 0.61,P= .009; HR, 0.62,P= .02; and HR, 0.50,P= .002; respectively). HD benefit was seen in the subgroup of older patients (50-60 years) with theFLT3-ITD orNPM1mutation. Additionally, the presence of anNPM1mutation confers a favorable prognosis only for patients receiving anthracycline dose intensification during induction. PMID:26755712

  20. Evaluation of bisphenol E cyanate ester for the resin-injection repair of advanced composites

    NASA Astrophysics Data System (ADS)

    Lio, Wilber Yaote

    Polymer matrix composites (PMCs) are susceptible to impacts that often result in microcracks and delaminations that can greatly reduce their mechanical integrity. Current injection repair techniques are limited to low glass transition temperature (Tg) composites due to the temperature and viscosity limitations of current repair resins. Bisphenol E cyanate ester (BECy) has both a high Tg and low prepolymer viscosity that makes it an ideal resin for the injection repair of high temperature PMCs. In addition, alumina nanoparticles have been shown to increase the strengths of some adhesives as well as impart shear thinning properties in suspension; both of which are desirable effects for injection repair. Lap shear tests were performed to evaluate adhesive properties of BECy and BECy-alumina nanocomposites. Effects of substrate, temperature, nanoparticle loading, and moisture were investigated. A resin-injection process was developed and the efficiency of BECy in repairing bismaleimide-carbon fiber composite plates was studied through ultrasonic evaluation and compression-after-impact tests.

  1. Microstructure Formation and Fracturing Characteristics of Grey Cast Iron Repaired Using Laser

    PubMed Central

    Liu, Dan; Shi, Yongjun

    2014-01-01

    The repairing technology based on laser rapid fusion is becoming an important tool for fixing grey cast iron equipment efficiently. A laser repairing protocol was developed using Fe-based alloy powders as material. The microstructure and fracturing feature of the repaired zone (RZ) were analyzed. The results showed that regionally organized RZ with good density and reliable metallurgical bond can be achieved by laser repairing. At the bottom of RZ, dendrites existed in similar direction and extended to the secondary RZ, making the grains grow extensively with inheritance with isometric grains closer to the surface substrate. The strength of the grey cast iron base material was maintained by laser repairing. The base material and RZ were combined with robust strength and fracture resistance. The prevention and deflection of cracking process were analyzed using a cracking process model and showed that the overall crack toughness of the materials increased. PMID:25032230

  2. Nucleotide excision repair proteins and interstrand crosslink repair

    PubMed Central

    Wood, Richard D.

    2010-01-01

    Although various schemes for interstrand crosslink (ICL) repair incorporate recombination, replication, and double-strand break intermediate steps, action of the NER system or some variation of it is a common feature of most models. In the bacterium Escherichia coli, the NER enzyme UvrABC can incise on either side of an ICL to unhook the crosslink, and repair can proceed via a subsequent recombination step. The relevance of NER to ICL repair in mammalian cells has been challenged. Of all NER mutants, it is clear that ERCC1 and XPF-defective cells show the most pronounced sensitivities to ICL-inducing agents, and defects in ICL repair. However, there is good evidence that cells defective in NER proteins including XPA and XPG are also more sensitive than normal to ICL-inducing agents. These results are summarized here, together with evidence for defective crosslink removal in NER-defective cells. Studies of incision at sites of ICL by cell extracts and purified proteins have been done, but these studies are not all consistent with one another and further research is required. PMID:20658645

  3. Mountain Plains Learning Experience Guide: Automotive Repair. Course: Engine Repair.

    ERIC Educational Resources Information Center

    Schramm, C.; Osland, Walt

    One of twelve individualized courses included in an automotive repair curriculum, this course covers theory and construction, inspection diagnoses, and service and overhaul of automotive engines. The course is comprised of five units: (1) Fundamentals of Four-Cycle Engines, (2) Engine Construction, (3) Valve Train, (4) Lubricating Systems, and (5)…

  4. Clinical, cytogenetic, and molecular diagnosis of Angelman syndrome: Estimated prevalence rate in a Danish country

    SciTech Connect

    Petersen, M.B.; Brondum-Nielsen, K.; Hansen, L.K.; Wulff, K.

    1995-06-19

    Angelman syndrome (AS) was initially considered a rather rare abnormality, but in later years, with the possibilities for cytogenetic and molecular diagnosis an increasing number of patients have been reported. The incidence is quoted to be around 1:20,000. The etiology of AS is associated with the lack of maternal allele(s) of one or more loci at 15q11-q13, and is considered an effect of parental imprinting of that region, since a similar deficiency of paternal alleles leads to Prader-Willi syndrome. 9 refs., 1 tab.

  5. No short-term cytogenetic consequences of Hungarian red mud catastrophe.

    PubMed

    Gundy, Sarolta; Farkas, Gyöngyi; Székely, Gábor; Kásler, Miklós

    2013-01-01

    Red mud is an industrial waste produced in the process of alumina extraction from bauxite with concentrated NaOH. When the red mud-containing reservoir collapsed in Ajka Alumina Plant Hungary in October 2010, the most serious immediate effects were caused by the high alkalinity (pH ≥ 13) of the flood. Many persons suffered burn-like damage to tissues and contact with caustic desiccated ultra-fine dust with traces of toxic metals also caused irritation of upper respiratory tract and eyes. This catastrophe was unique from the point of view of genotoxic effects as well. Therefore cytogenetic examinations were carried out on inhabitants, either with burns (17 persons) or on those inhaling desiccated caustic dust (42 persons). Chromosomal aberration (CA) analysis and bleomycin (BLM)-sensitivity assays, as possible markers of effects, were studied in peripheral blood lymphocytes of persons within 4-6 weeks following the catastrophe. Controls were matched for age, sex and smoking habits, and also places of residence with different constituents of air pollution either from rural (59 persons), or from urban environments (59 persons). Neither spontaneous rate of CAs (1.47% vs. 1.69%) nor BLM-induced in vitro chromosomal breakage (0.79 vs. 0.83 break/cell) showed elevated rates when cytogenetic biomarkers of genotoxicity were compared between controls and exposed persons. Time spent in cleaning did not affect cytogenetic changes either (R(2) = 0.04). BLM-induced mutagen sensitivity was similar in exposed and control persons (27.1% vs. 30.5%). It seems that the red mud exposure does not appear to pose an immediate genotoxic hazard on residents when measured with cytogenetic methods. We recommend, however, that those involved in clean-up activities should be followed closely not only for overall health, but also for further genotoxic risk assessment, because the long-term hazards of ultra-fine fugitive dust particles with alkalinity of residual NaOH in red mud are still

  6. [Comparative cytogenetic study of the tetraploid Matricaria chamomilla L. and Matricaria inodora L].

    PubMed

    Samatadze, T E; Amosova, A V; Mel'nikova, N V; Suslina, S N; Zagumennikova, T N; Zelenin, A V; Bykov, V A; Muravenko, O N

    2014-01-01

    A comparative cytogenetic study of the autotetraploid breed of Matricaria chamomilla L. (M. recutita L.) and Matricaria inodora L. was carried out by DAPI-banding, fluorescent hybridization in situ (FISH) with 26S and 5S rDNA probes, and analysis of meiosis. All chromosomes were identified in both karyotypeson the basis of DAPI-banding images and 26S and 5S rDNA distribution, and species-specific idiograms were composed for both M. chamomilla and M. indora taking into account the polymorphous variants of DAPI-banding images, showing the location of the 26S and 5S rDNA sites. PMID:25735163

  7. Cytogenetic characterization of a fibroma and three haemangiopericytomas in domestic dogs.

    PubMed

    Mayr, B; Scheller, M; Reifinger, M; Loupal, G

    1995-01-01

    Cytogenetic evaluation of tumour cells taken from an 11-year-old mixed breed birth with a fibroma, showed trisomy 1 (2n = 79) and often the presence of a third copy of chromosome 4. In a 13-year-old mixed breed Boxer bitch with a haemangiopericytoma, trisomy 9 (2n = 79) was present. In contrast, another haemangiopericytoma (in a 15-year-old rough-haired Dachshund bitch) showed a deleted chromosome 1, several centric fusions and trisomy 2. Trisomy 2 and trisomy 29 were detected in a third haemangiopericytoma from an 11-year-old rough-haired Dachshund bitch. PMID:7552199

  8. [Cytogenetic effects of 1,4-dihydropyridine in various test systems].

    PubMed

    Kuzhir, T D; Goncharova, R I; Zolotareva, G N

    1984-01-01

    Cytogenetic effect of 1,4-dihydropyridine was studied in different test-systems. The preparation is shown to decrease the level of complete sex-chromosome losses in Drosophila and chromosome aberration frequency in Allium fistulosum seedlings. The preparation does not affect spontaneous mutability of bone marrow cells in mice, high doses of the preparation have no mutagenic potential. Thus, 1,4-dihydropyridine shows antimutagenic activity reducing the chromosome mutation level in sex and somatic cells of eucaryotic organisms. Absence of the effect on mice chromosomes may testify to the specificity of 1,4-dihydropyridine action. PMID:6506216

  9. Cytogenetic effects of aqueous extracts of the medicinal plant paico (chenopodium multifidum L.).

    PubMed

    Gadano, A; Gurni, A; Nigro López, M; López, P; Gratti, A; van Baren, C; Ferraro, G; Carballo, M

    2000-01-01

    The cytogenetic effects of aqueous extracts of Chenopodium multifidum L. (Paico) were determined by addition of the extracts and fractions to human lymphocyte cultures. Toxicity was evaluated by analysis of chromosomal aberrations (CA), sister chromatid exchange (SCE), mitotic (MI) and replication (RI) indexes. The results showed an increase in CA frequency in cultures exposed to infusion decoction, no modification in the CPK values either in the decoction or in the infusion, and a decrease in the MI of lymphocyte cultures exposed to the decoction. These results suggested genotoxic effects of "Paico" aqueous extracts. PMID:21214432

  10. Cytogenetic and clinical features of a 13 year old male with trisomy 8

    PubMed Central

    Balkan, Mahmut; Fidanboy, Mehmet; Özmen, Cihan; Özbek, M. Nuri; Otçu, Selçuk; Kapı, Emin; Budak, Turgay

    2012-01-01

    Trisomy 8 is a relatively rare chromosomal abnormality. The majority of cases present with the mosaic form. Regular trisomy 8 is usually lethal and frequently results in miscarriage, while those with “trisomy 8 mosaicism” are more likely to survive. We report clinical observations and cytogenetic studies of a 13-year-old male with regular trisomy 8 and compared with those of other known cases of trisomy 8. The most discriminating findings for this condition are skeletal anomalies, restricted articular function, and speech problems. Our results are in agreement with those of previous studies for trisomy 8.

  11. Automation of spot counting in interphase cytogenetics using brightfield microscopy

    SciTech Connect

    Vrolijk, H.; Sloos, W.C.R.; Rijke, F.M. van de

    1996-06-01

    In situ hybridization techniques allow the enumeration of chromosomal abnormalities and form a great potential for many clinical applications. Although the use of fluorescent labels is preferable regarding sensitivity and colormultiplicity, chromogenic labels can provide an excellent alternative in relatively simple situations, e.g., where it is sufficient to use a centromere-specific probe to detect abnormalities of one specific chromosome. When the frequency of chromosomal aberrations is low, several hundreds or even thousands of cells have to be evaluated to achieve sufficient statistical confidence. Since manual counting is tedious, fatiguing, and time consuming, automation can assist to process the slides more efficiently. Therefore, a system has been developed for automated spot counting using brightfield microscopy. This paper addresses both the hardware system aspects and the software image analysis algorithms for nuclei and spot detection. As a result of the automated slide analysis the system provides the frequency spot distribution of the selected cells. The automatic classification can, however, be overruled by human interaction, since each individual cell is stored in a gallery and can be relocated for visual inspection. With this system a thousand cells can be automatically analyzed in approximately 10 min, while an extra 5-10 min is necessary for visual evaluation. The performance of the system was analyzed using a model system for trisomy consisting of a mixture of male and female lymphocytes hybridized with probes for chromosomes 7 and Y. The sensitivity for trisomy detection in the seeding experiment was such that a frequency of 3% trisomic cells could be picked up automatically as being abnormal according to the multiple proportion test, while trisomy as low as 1.5% could be detected after interaction. 26 refs., 4 figs., 4 tabs.

  12. Repair of nonreplicating UV-irradiated DNA: cooperative dark repair by Escherichia coli uvr and phr functions

    SciTech Connect

    Hays, J.B.; Martin, S.J.; Bhatia, K.

    1985-02-01

    The system previously used to study recombination of nonreplicating UV-irradiated phage lambda DNA was adapted to study UV repair. Irradiated phages infected undamaged homoimmune lysogens. Pyrimidine dimer content (by treatment with Micrococcus luteus UV endonuclease and alkaline sucrose sedimentation) and a biological activity endpoint (infectivity in transfection of uvrB recA recB spheroplasts) were followed. Unless room light was excluded during DNA extraction procedures, photoreactivation (Phr function) was significant. In uvr ..delta..phr bacteria, repair, by both assays, was very low but not zero. Even when light was totally excluded, Phr function appeared to play a role in Uvr-mediated excision repair: both dimer removal and restoration of infectivity were two to five times as efficient in uvr/sup +/ phr/sup +/ bacteria as in uvr/sup +/ ..delta..phr bacteria. Similarly, UV-irradiated phages plated with higher efficiencies on phr/sup +/ than ..delta..phr bacteria even under totally dark conditions. In uvr phr/sup +/ repressed infections, removal of dimers from nonreplicating DNA did not increase infectivity as much as in uvr2= infections, suggesting a requirement for repair of nondimer photoproducts by the uvrABC system.

  13. Integration of microarray analysis into the clinical diagnosis of hematological malignancies: How much can we improve cytogenetic testing?

    PubMed Central

    Peterson, Jess F.; Aggarwal, Nidhi; Smith, Clayton A.; Gollin, Susanne M.; Surti, Urvashi; Rajkovic, Aleksandar; Swerdlow, Steven H.; Yatsenko, Svetlana A.

    2015-01-01

    Purpose To evaluate the clinical utility, diagnostic yield and rationale of integrating microarray analysis in the clinical diagnosis of hematological malignancies in comparison with classical chromosome karyotyping/fluorescence in situ hybridization (FISH). Methods G-banded chromosome analysis, FISH and microarray studies using customized CGH and CGH+SNP designs were performed on 27 samples from patients with hematological malignancies. A comprehensive comparison of the results obtained by three methods was conducted to evaluate benefits and limitations of these techniques for clinical diagnosis. Results Overall, 89.7% of chromosomal abnormalities identified by karyotyping/FISH studies were also detectable by microarray. Among 183 acquired copy number alterations (CNAs) identified by microarray, 94 were additional findings revealed in 14 cases (52%), and at least 30% of CNAs were in genomic regions of diagnostic/prognostic significance. Approximately 30% of novel alterations detected by microarray were >20 Mb in size. Balanced abnormalities were not detected by microarray; however, of the 19 apparently “balanced” rearrangements, 55% (6/11) of recurrent and 13% (1/8) of non-recurrent translocations had alterations at the breakpoints discovered by microarray. Conclusion Microarray technology enables accurate, cost-effective and time-efficient whole-genome analysis at a resolution significantly higher than that of conventional karyotyping and FISH. Array-CGH showed advantage in identification of cryptic imbalances and detection of clonal aberrations in population of non-dividing cancer cells and samples with poor chromosome morphology. The integration of microarray analysis into the cytogenetic diagnosis of hematologic malignancies has the potential to improve patient management by providing clinicians with additional disease specific and potentially clinically actionable genomic alterations. PMID:26299921

  14. Molecular and Cytogenetic Characterization of Wild Musa Species

    PubMed Central

    Čížková, Jana; Hřibová, Eva; Christelová, Pavla; Van den Houwe, Ines; Häkkinen, Markku; Roux, Nicolas; Swennen, Rony; Doležel, Jaroslav

    2015-01-01

    The production of bananas is threatened by rapid spreading of various diseases and adverse environmental conditions. The preservation and characterization of banana diversity is essential for the purposes of crop improvement. The world's largest banana germplasm collection maintained at the Bioversity International Transit Centre (ITC) in Belgium is continuously expanded by new accessions of edible cultivars and wild species. Detailed morphological and molecular characterization of the accessions is necessary for efficient management of the collection and utilization of banana diversity. In this work, nuclear DNA content and genomic distribution of 45S and 5S rDNA were examined in 21 diploid accessions recently added to ITC collection, representing both sections of the genus Musa. 2C DNA content in the section Musa ranged from 1.217 to 1.315 pg. Species belonging to section Callimusa had 2C DNA contents ranging from 1.390 to 1.772 pg. While the number of 45S rDNA loci was conserved in the section Musa, it was highly variable in Callimusa species. 5S rRNA gene clusters were found on two to eight chromosomes per diploid cell. The accessions were genotyped using a set of 19 microsatellite markers to establish their relationships with the remaining accessions held at ITC. Genetic diversity done by SSR genotyping platform was extended by phylogenetic analysis of ITS region. ITS sequence data supported the clustering obtained by SSR analysis for most of the accessions. High level of nucleotide diversity and presence of more than two types of ITS sequences in eight wild diploids pointed to their origin by hybridization of different genotypes. This study significantly expands the number of wild Musa species where nuclear genome size and genomic distribution of rDNA loci is known. SSR genotyping identified Musa species that are closely related to the previously characterized accessions and provided data to aid in their classification. Sequence analysis of ITS region

  15. Abdominal aortic aneurysm repair - open - discharge

    MedlinePlus

    AAA - open - discharge; Repair - aortic aneurysm - open - discharge ... You had open aortic aneurysm surgery to repair an aneurysm (a widened part) in your aorta, the large artery that carries blood to your ...

  16. Final report [DNA Repair and Mutagenesis - 1999

    SciTech Connect

    Walker, Graham C.

    2001-05-30

    The meeting, titled ''DNA Repair and Mutagenesis: Mechanism, Control, and Biological Consequences'', was designed to bring together the various sub-disciplines that collectively comprise the field of DNA Repair and Mutagenesis. The keynote address was titled ''Mutability Doth Play Her Cruel Sports to Many Men's Decay: Variations on the Theme of Translesion Synthesis.'' Sessions were held on the following themes: Excision repair of DNA damage; Transcription and DNA excision repair; UmuC/DinB/Rev1/Rad30 superfamily of DNA polymerases; Cellular responses to DNA damage, checkpoints, and damage tolerance; Repair of mismatched bases, mutation; Genome-instability, and hypermutation; Repair of strand breaks; Replicational fidelity, and Late-breaking developments; Repair and mutation in challenging environments; and Defects in DNA repair: consequences for human disease and aging.

  17. Strand specific DNA repair in different stages of the cell cycle

    SciTech Connect

    Lommel, L.; Crumpton, C.C.; Schimke, R.T.; Hanawalt, P.C. )

    1993-01-01

    The genomic location of a DNA lesions can dramatically influence the efficiency of repair. For example, in asynchronous human cells there is preferential repair of UV-induced cyclobutane pyrimidine dimers (CPDs) in the transcribed strands of active genes. The efficiencies of repair in the non-transcribed strands of the genes examined thus far are essentially equivalent to that in the genome overall, but significantly slower than that in the transcribed strands. The authors' current interest is how these DNA repair efficiencies might be influenced by the phase of the cell cycle. They developed a method to assay repair of specific DNA sequences in any phase of the cell cycle, using a synchronization procedure that does not perturb the cell cycle. Ethanol fixed cells were stained with chromomycin A3 and sorted on the basis of DNA content. Fractions were collected corresponding to G1; early, middle and late S; and G2/M. They are currently examining the initial frequency of CPDs and the efficiencies of repair in each strand of the dihydrofolate reductase gene in cultured human cells. These experiments are important to an understanding of how the heterogeneity in DNA damage processing in particular sequences and as a function of the cell cycle may be involved in biological endpoints such as mutagenesis and malignant transformation.

  18. Mismatch-mediated error prone repair at the Immunoglobulin genes

    PubMed Central

    Chahwan, Richard; Edelmann, Winfried; Scharff, Matthew D; Roa, Sergio

    2011-01-01

    The generation of effective antibodies depends upon somatic hypermutation (SHM) and class-switch recombination (CSR) of antibody genes by activation induced cytidine deaminase (AID) and the subsequent recruitment of error prone base excision and mismatch repair. While AID initiates and is required for SHM, more than half of the base changes that accumulate in V regions are not due to the direct deamination of dC to dU by AID, but rather arise through the recruitment of the mismatch repair complex (MMR) to the U:G mismatch created by AID and the subsequent perversion of mismatch repair from a high fidelity process to one that is very error prone. In addition, the generation of double-strand breaks (DSBs) is essential during CSR, and the resolution of AID-generated mismatches by MMR to promote such DSBs is critical for the efficiency of the process. While a great deal has been learned about how AID and MMR cause hypermutations and DSBs, it is still unclear how the error prone aspect of these processes is largely restricted to antibody genes. The use of knockout models and mice expressing mismatch repair proteins with separation-of-function point mutations have been decisive in gaining a better understanding of the roles of each of the major MMR proteins and providing further insight into how mutation and repair are coordinated. Here, we review the cascade of MMR factors and repair signals that are diverted from their canonical error free role and hijacked by B cells to promote genetic diversification of the Ig locus. This error prone process involves AID as the inducer of enzymatically-mediated DNA mismatches, and a plethora of downstream MMR factors acting as sensors, adaptors and effectors of a complex and tightly regulated process from much of which is not yet well understood. PMID:22100214

  19. Small Engine Repair Course Outline.

    ERIC Educational Resources Information Center

    DeClouet, Fred

    Small engines as referred to here are engines used on lawn mowers, chain saws, power plants, outboards, and cycles. It does not include engines used on automobiles. The course outlined is intended to show how small two-cycle and four-cycle gas engines are constructed, how they operate, what goes wrong, and how to service and repair them. It is…

  20. URIC ACID AND TISSUE REPAIR

    PubMed Central

    NERY, Rodrigo Araldi; KAHLOW, Barbara Stadler; SKARE, Thelma L; TABUSHI, Fernando Issamu; CASTRO, Adham do Amaral e

    2015-01-01

    Uric acid, a metabolic product of purines, may exert a role in tissue healing. In this review we will explore its role as an alarm initiating the inflammatory process that is necessary for tissue repair, as a scavenger of oxygen free radicals, as a mobilizer of progenitor endothelial cells and as supporter of adaptive immune system. PMID:26734804

  1. Computer Equipment Repair Curriculum Guide.

    ERIC Educational Resources Information Center

    Reneau, Fred; And Others

    This guide is intended for use in a course to train students to repair computer equipment and perform related administrative and customer service tasks. Addressed in the individual units are the following topics (with selected subtopics in brackets): performing administrative functions (preparing service bills, maintaining accounts and labor…

  2. Anodization As A Repair Technique

    NASA Technical Reports Server (NTRS)

    Groff, Roy E.; Maloney, Robert D.; Reeser, Robert W.

    1988-01-01

    Thin, hard oxide layer added to aluminum part. Surfaces on aluminum part worn out of tolerance by no more than 0.004 in. often repaired by anodizing to build up aluminum oxide layers. Oxide layers very hard and grounded to desired final dimensions.

  3. Laparoscopic repair of paraesophageal hernia.

    PubMed Central

    Willekes, C L; Edoga, J K; Frezza, E E

    1997-01-01

    OBJECTIVE: The purpose of this report is to describe the authors' technique for the laparoscopic repair of paraesophageal hernias and the outcome in their series of patients. METHODS: Thirty patients underwent elective laparoscopic repair of paraesophageal hernias. All were pure type II paraesophageal hernias as defined by upper gastrointestinal contrast studies. All operations were performed by a single surgeon (JKE) assisted by five different chief surgical residents. The authors have used various prototypes of a laparoscopic utility belt to reduce the physician requirement to the surgeon and a first assistant. The operative setup and specific techniques of the repair are described and illustrated. A concomitant anti-reflux procedure was performed in the last 23 patients. RESULTS: Satisfactory repair using video-laparoscopic techniques was achieved in all cases. There were no deaths. Complications occurred in 8 of 30 patients. Postoperative gastroesophageal reflux developed in three of the first seven patients in whom fundoplication was not performed. Three consecutive patients had left lower lobe atelectasis believed to be related to endotracheal tube displacement during the passage of the bougie. One patient had postoperative dysphagia. There was one case of major deep venous thrombosis with pulmonary embolism. Twenty-eight of 30 patients were discharged home by postoperative day 3. Twenty-four of 30 patients had returned to normal activity by the time of their first postoperative office visit 1 week after surgery. Images Figure 9. Figure 10. PMID:8998118

  4. How the Brain Repairs Stuttering

    ERIC Educational Resources Information Center

    Kell, Christian A.; Neumann, Katrin; von Kriegstein, Katharina; Posenenske, Claudia; von Gudenberg, Alexander W.; Euler, Harald; Giraud, Anne-Lise

    2009-01-01

    Stuttering is a neurodevelopmental disorder associated with left inferior frontal structural anomalies. While children often recover, stuttering may also spontaneously disappear much later after years of dysfluency. These rare cases of unassisted recovery in adulthood provide a model of optimal brain repair outside the classical windows of…

  5. Microwave Oven Repair. Teacher Edition.

    ERIC Educational Resources Information Center

    Smreker, Eugene

    This competency-based curriculum guide for teachers addresses the skills a technician will need to service microwave ovens and to provide customer relations to help retain the customer's confidence in the product and trust in the service company that performs the repair. The guide begins with a task analysis, listing 20 cognitive tasks and 5…

  6. [A Nobel Prize for DNA repair].

    PubMed

    Jordan, Bertrand

    2016-01-01

    This year's Nobel Prize for chemistry recognizes the seminal contributions of three researchers who discovered the existence and the basic mechanisms of DNA repair: base excision repair, mismatch repair, and nucleotide excision repair. They have since been joined by many scientists elucidating diverse aspects of these complex mechanisms that now constitute a thriving research field with many applications, notably for understanding oncogenesis and devising more effective therapies. PMID:26850617

  7. Fix-It Careers: Jobs in Repair

    ERIC Educational Resources Information Center

    Torpey, Elka Maria

    2010-01-01

    From auto mechanic to HVAC technicians, many occupations require repair skills. For jobseekers with the right skills, there are many advantages to a repair career. Repair work provides millions of jobs throughout the United States. Wages are often higher than average. And in many occupations, the employment outlook is bright. Plus, most repair…

  8. 40 CFR 63.1024 - Leak repair.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... reading measured by Method 21 of 40 CFR part 60, appendix A at the time the leak is successfully repaired...) Repair requires replacing the existing seal design with a new system that the owner or operator has... repaired within 15 calendar days after discovery of the leak as specified in paragraphs (f)(4)(i) and...

  9. 33 CFR 115.40 - Bridge repairs.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Bridge repairs. 115.40 Section 115.40 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE PROCEDURES § 115.40 Bridge repairs. Repairs to a bridge which...

  10. 33 CFR 115.40 - Bridge repairs.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Bridge repairs. 115.40 Section 115.40 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE PROCEDURES § 115.40 Bridge repairs. Repairs to a bridge which...

  11. 33 CFR 115.40 - Bridge repairs.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Bridge repairs. 115.40 Section 115.40 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE PROCEDURES § 115.40 Bridge repairs. Repairs to a bridge which...

  12. 33 CFR 115.40 - Bridge repairs.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 33 Navigation and Navigable Waters 1 2011-07-01 2011-07-01 false Bridge repairs. 115.40 Section 115.40 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE PROCEDURES § 115.40 Bridge repairs. Repairs to a bridge which...

  13. 33 CFR 115.40 - Bridge repairs.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Bridge repairs. 115.40 Section 115.40 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY BRIDGES BRIDGE LOCATIONS AND CLEARANCES; ADMINISTRATIVE PROCEDURES § 115.40 Bridge repairs. Repairs to a bridge which...

  14. Bringing mask repair to the next level

    NASA Astrophysics Data System (ADS)

    Edinger, K.; Wolff, K.; Steigerwald, H.; Auth, N.; Spies, P.; Oster, J.; Schneider, H.; Budach, M.; Hofmann, T.; Waiblinger, M.

    2014-10-01

    Mask repair is an essential step in the mask manufacturing process as the extension of 193nm technology and the insertion of EUV are drivers for mask complexity and cost. The ability to repair all types of defects on all mask blank materials is crucial for the economic success of a mask shop operation. In the future mask repair is facing several challenges. The mask minimum features sizes are shrinking and require a higher resolution repair tool. At the same time mask blanks with different new mask materials are introduced to optimize optical performance and long term durability. For EUV masks new classes of defects like multilayer and phase defects are entering the stage. In order to achieve a high yield, mask repair has to cover etch and deposition capabilities and must not damage the mask. These challenges require sophisticated technologies to bring mask repair to the next level. For high end masks ion-beam based and e-based repair technologies are the obvious choice when it comes to the repair of small features. Both technologies have their pro and cons. The scope of this paper is to review and compare the performance of ion-beam based mask repair to e-beam based mask repair. We will analyze the limits of both technologies theoretically and experimentally and show mask repair related performance data. Based on this data, we will give an outlook to future mask repair tools.

  15. Welding/brazing for Space Station repair

    NASA Technical Reports Server (NTRS)

    Dickinson, David W.; Babel, H. W.; Conaway, H. R.; Hooper, W. H.

    1990-01-01

    Viewgraphs on welding/brazing for space station repair are presented. Topics covered include: fabrication and repair candidates; debris penetration of module panel; welded repair patch; mechanical assembly of utility fluid line; space station utility systems; Soviet aerospace fabrication - an overview; and processes under consideration.

  16. Standardized Curriculum for Small Engine Repair.

    ERIC Educational Resources Information Center

    Mississippi State Dept. of Education, Jackson. Office of Vocational, Technical and Adult Education.

    This curriculum guide for small engine repair was developed by the state of Mississippi to standardize vocational education course titles and core contents. The objectives contained in this document are common to all small engine repair programs in the state. The guide contains objectives for small engine repair I and II courses. Units in course I…

  17. Standardized Curriculum for Shoe and Boot Repair.

    ERIC Educational Resources Information Center

    Mississippi State Dept. of Education, Jackson. Office of Vocational, Technical and Adult Education.

    This curriculum guide for shoe and boot repair was developed by the state of Mississippi to standardize vocational education course titles and core contents. The objectives contained in this document are common to all shoe and boot repair programs in the state. The guide contains objectives for shoe and boot repair I and II courses. Units in…

  18. Cartilage repair: 2013 Asian update.

    PubMed

    Hui, James H P; Goyal, Deepak; Nakamura, Norimasa; Ochi, Mitsuo

    2013-12-01

    Despite financial and regulatory hurdles, Asian scientists and clinicians have made important contributions in the area of cartilage repair. Because it is impossible to include observations on all the published articles in one review, our attempt is to highlight Asian progress in this area during recent years (2005 to the present), reviewing research development and clinical studies. In the former, our discussion of in vitro studies focuses on (1) potential sources of stem cells--such as mesenchymal stem cells (MSCs) from marrow, cord blood, synovium, and mobilized peripheral blood--which are capable of enhancing cartilage repair and (2) the use of growth factors and scaffolds with and without cells. Our discussion of animal studies attempts to summarize activities in evaluating surgical procedures and determining the route of cell administration, as well as studies on matrices and scaffolds. It ranges from the use of small animals such as rats and rabbits to larger animals like pigs and dogs. The local adherent technique, enhancement of microfracture with poly(l-lactic-co-glycolic acid) scaffold, adenovirus-mediated bone morphogenic protein (BMP) genes, and MSCs--whether they are magnetically labeled, suspended in hyaluronic acid, or immobilized with transforming growth factor-β (TGF-β)--have all been able to engineer a repair of the osteochondral defect. Although published Asian reports of clinical studies on cartilage repair are few, the findings of relevant trials are summarized in our discussion of these investigations. There has been a long history of use of laboratory-derived MSCs for cartilage repair. Recent progress has suggested the potential utility of cord blood and mobilized peripheral blood in this area, as well as more injectable bone marrow (BM)-derived stem cells. Finally, we make a few suggestions on the direction of research and development activities and the need for collaborative approaches by regulatory agencies. PMID:24286798

  19. Laparoscopic Repair of Ventral Hernias

    PubMed Central

    Heniford, B Todd; Park, Adrian; Ramshaw, Bruce J.; Voeller, Guy

    2003-01-01

    Objective: To evaluate the efficacy and safety of laparoscopic repair of ventral hernias. Summary Background Data: The recurrence rate after standard repair of ventral hernias may be as high as 12-52%, and the wide surgical dissection required often results in wound complications. Use of a laparoscopic approach may decrease rates of complications and recurrence after ventral hernia repair. Methods: Data on all patients who underwent laparoscopic ventral hernia repair (LVHR) performed by 4 surgeons using a standardized procedure between November 1993 and October 2002 were collected prospectively (85% of patients) or retrospectively. Results: LVHR was completed in 819 of the 850 patients (422 men; 428 women) in whom it was attempted. Thirty-four percent of completed LVHRs were for recurrent hernias. The patient mean body mass index was 32; the mean defect size was 118 cm2. Mesh, averaging 344 cm2, was used in all cases. Mean operating time was 120 min, mean estimated blood loss was 49 mL, and hospital stay averaged 2.3 days. There were 128 complications in 112 patients (13.2%). One patient died of a myocardial infarction. The most common complications were ileus (3%) and prolonged seroma (2.6%). During a mean follow-up time of 20.2 months (range, 1-94 months), the hernia recurrence rate was 4.7%. Recurrence was associated with large defects, obesity, previous open repairs, and perioperative complications. Conclusion: In this large series, LVHR had a low rate of conversion to open surgery, a short hospital stay, a moderate complication rate, and a low risk of recurrence. PMID:14501505

  20. Repair of Chromosomal Double-Strand Breaks by Precise Ligation in Human Cells

    PubMed Central

    Lin, William Y.; Wilson, John H.; Lin, Yunfu

    2013-01-01

    Double-strand breaks (DSBs), a common type of DNA lesion, occur daily in human cells as a result of both endogenous and exogenous damaging agents. DSBs are repaired in two general ways: by the homology-dependent, error-free pathways of homologous recombination (HR) and by the homology-independent, error-prone pathways of nonhomologous end-joining (NHEJ), with NHEJ predominating in most cells. DSBs with compatible ends can be re-joined in vitro with DNA ligase alone, which raises the question of whether such DSBs require the more elaborate machinery of NHEJ to be repaired in cells. Here we report that chromosomal DSBs with compatible ends introduced by the rare-cutting endonuclease, ISceI, are repaired by precise ligation nearly 100% of the time in human cells. Precise ligation depends on the classical NHEJ components Ku70, XRCC4, and DNA ligase IV, since siRNA knockdowns of these factors significantly reduced the efficiency of precise ligation. Interestingly, knockdown of the tumor suppressors p53 or BRCA1 showed similar effects as the knockdowns of NHEJ factors. In contrast, knockdown of components involved in alternative NHEJ, mismatch repair, nucleotide excision repair, and single-strand break repair did not reduce precise ligation. In summary, our results demonstrate that DSBs in human cells are efficiently repaired by precise ligation, which requires classical NHEJ components and is enhanced by p53 and BRCA1. PMID:23707303

  1. Bonded repair of composite aircraft structures: A review of scientific challenges and opportunities

    NASA Astrophysics Data System (ADS)

    Katnam, K. B.; Da Silva, L. F. M.; Young, T. M.

    2013-08-01

    Advanced composite materials have gained popularity in high-performance structural designs such as aerospace applications that require lightweight components with superior mechanical properties in order to perform in demanding service conditions as well as provide energy efficiency. However, one of the major challenges that the aerospace industry faces with advanced composites - because of their inherent complex damage behaviour - is structural repair. Composite materials are primarily damaged by mechanical loads and/or environmental conditions. If material damage is not extensive, structural repair is the only feasible solution as replacing the entire component is not cost-effective in many cases. Bonded composite repairs (e.g. scarf patches) are generally preferred as they provide enhanced stress transfer mechanisms, joint efficiencies and aerodynamic performance. With an increased usage of advanced composites in primary and secondary aerospace structural components, it is thus essential to have robust, reliable and repeatable structural bonded repair procedures to restore damaged composite components. But structural bonded repairs, especially with primary structures, pose several scientific challenges with the current existing repair technologies. In this regard, the area of structural bonded repair of composites is broadly reviewed - starting from damage assessment to automation - to identify current scientific challenges and future opportunities.

  2. Analysis and Testing of a Metallic Repair Applicable to Pressurized Composite Aircraft Structure

    NASA Technical Reports Server (NTRS)

    Przekop, Adam; Jegley, Dawn C.; Rouse, Marshall; Lovejoy, Andrew E.

    2014-01-01

    Development of repair technology is vital to the long-term application of new structural concepts on aircraft structure. The design, analysis, and testing of a repair concept applicable to a stiffened composite panel based on the Pultruded Rod Stitched Efficient Unitized Structure was recently completed. The damage scenario considered was a mid-bay to mid-bay saw-cut with a severed stiffener, flange, and skin. A bolted metallic repair was selected so that it could be easily applied in the operational environment. The present work describes results obtained from tension and pressure panel tests conducted to validate both the repair concept and finite element analysis techniques used in the design effort. Simulation and experimental strain and displacement results show good correlation, indicating that the finite element modeling techniques applied in the effort are an appropriate compromise between required fidelity and computational effort. Static tests under tension and pressure loadings proved that the proposed repair concept is capable of sustaining load levels that are higher than those resulting from the current working stress allowables. Furthermore, the pressure repair panel was subjected to 55,000 pressure load cycles to verify that the design can withstand a life cycle representative for a transport category aircraft. These findings enable upward revision of the stress allowables that had been kept at an overly-conservative level due to concerns associated with repairability of the panels. This conclusion enables more weight efficient structural designs utilizing the composite concept under investigation.

  3. Essential Roles for Polymerase θ-Mediated End Joining in the Repair of Chromosome Breaks.

    PubMed

    Wyatt, David W; Feng, Wanjuan; Conlin, Michael P; Yousefzadeh, Matthew J; Roberts, Steven A; Mieczkowski, Piotr; Wood, Richard D; Gupta, Gaorav P; Ramsden, Dale A

    2016-08-18

    DNA polymerase theta (Pol θ)-mediated end joining (TMEJ) has been implicated in the repair of chromosome breaks, but its cellular mechanism and role relative to canonical repair pathways are poorly understood. We show that it accounts for most repairs associated with microhomologies and is made efficient by coupling a microhomology search to removal of non-homologous tails and microhomology-primed synthesis across broken ends. In contrast to non-homologous end joining (NHEJ), TMEJ efficiently repairs end structures expected after aborted homology-directed repair (5' to 3' resected ends) or replication fork collapse. It typically does not compete with canonical repair pathways but, in NHEJ-deficient cells, is engaged more frequently and protects against translocation. Cell viability is also severely impaired upon combined deficiency in Pol θ and a factor that antagonizes end resection (Ku or 53BP1). TMEJ thus helps to sustain cell viability and genome stability by rescuing chromosome break repair when resection is misregulated or NHEJ is compromised. PMID:27453047

  4. The accumulation of stable cytogenetic rearrangements with age-determined by chromosome painting

    SciTech Connect

    Ramsey, M.J.; Lee, D.A.; Senft, J.R.; Briner, J.F.; Moore, D.H. II; Tucker, J.D.

    1994-12-31

    Chromosome painting is a rapid method of quantifying structural chromosomal rearrangements. The method is particularly useful for detecting stable aberrations which are difficult and expensive to quantify with classical methods. Translocations, being inherently stable, can be used as a biodosimeter for chronic and temporally-displaced exposure to radiation. Translocations may also be useful for quantifying chronic exposure to environmentally related agents which may result in an accumulation of cytogenetic damage with age. Because most chemical exposures are low and chronic, conventional cytogenetic methods are not expected to be informative. To understand the extent that age and lifestyle factors impact the frequency of stable aberrations, we used chromosome painting in healthy individuals who have not been occupationally or accidentally exposed to radiation or chemicals, and who have not received chemo- or radiotherapy. To date we have analyzed 15 umbilical cord bloods as well as peripheral blood samples from 83 adults aged up to 77 years. Because stable aberrations are rare in unexposed people, we have scored large numbers of cells from each subject. Thus far we have analyzed the equivalent of more than 78,000 metaphases from these 83 people, and have observed an average of 0.75% of cells with translocations or stable insertions. A significant curvilinear relationship with age is apparent (R{sup 2} = 0.69, p <0.00001). No effect with smoking was seen.

  5. Malignant myoepithelioma of soft tissue: a case report with cytogenetic findings.

    PubMed

    Balogh, Zsófia; Deák, Linda; Sápi, Zoltán

    2008-06-01

    Soft tissue malignant myoepithelioma (STMM) is a particularly rare tumor displaying myoepithelial elements and lacking obvious ductal differentiation. From the one case report with cytogenetic data available in the literature, STMM seems to be a distinct entity with some resemblance to chordoma on the one hand and myoepithelioma on the other. The present case of STMM yielded novel data from high-resolution comparative genomic hybridization (HR-CGH) analysis. An 82-year-old female patient presented with a soft tissue tumor within the deep soft tissues in the right gluteal muscle measuring 16 x 13 x 11 cm. Histologically, the lesion was diagnosed as a myoepithelial carcinoma. Immunohistochemistry was focally positive for pancytokeratin, EMA, S-100 protein, and alpha smooth muscle actin. HR-CGH analysis revealed gains of 1p31 approximately p34, 1q21 approximately q23, 9q12 approximately q33, and 16q22 and losses of 1p11 approximately p22, 1q24 approximately q44, 3p, 10q11.1 approximately q22, 13q, 14q13 approximately q24, and 15q. Subsequent fluorescence in situ hybridization analysis confirmed deletion of 3p, gain of 16q, and monosomy of chromosomes 13 and 15. These results support the hypothesis that STMM is a distinct entity, not sharing the cytogenetic alterations of salivary gland myoepithelial carcinomas and ductal carcinomas of breast with myoepithelial differentiation. PMID:18503832

  6. Comparative cytogenetic analysis of eleven species of subfamilies Neoplecostominae and Hypostominae (Siluriformes: Loricariidae).

    PubMed

    Alves, Anderson Luís; Oliveira, Claudio; Foresti, Fausto

    2005-07-01

    The family Loricariidae with about 690 species divided into six subfamilies, is one of the world's largest fish families. Recent studies have shown the existence of several problems in the definition of natural groups in the family, which has made the characterization of the subfamilies and even of some genera quite difficult. With the main objective of contributing for a better understanding of the relationships between loricariids, cytogenetic analysis were conducted with two species of Neoplecostominae and nine species of Hypostominae that, according to morphological and molecular data, may belong to a new monophyletic unit. The results obtained showed a marked chromosomal conservation with the presence of 2n = 54 chromosomes and single interstitial Ag-NORs in all species analyzed. Considering that Neoplecostominae is the primitive sister-group of all other loricariids, with exception of Lithogeneinae, this karyotypic structure may represent the primitive condition for the family Loricariidae. The cytogenetic characteristics partaken by the species of Neoplecostominae and Hypostominae analyzed in the present study reinforce the hypothesis that the species of both these subfamilies might belong to a natural group. PMID:16134327

  7. A comprehensive whole-genome integrated cytogenetic map for the alpaca (Lama pacos).

    PubMed

    Avila, Felipe; Baily, Malorie P; Perelman, Polina; Das, Pranab J; Pontius, Joan; Chowdhary, Renuka; Owens, Elaine; Johnson, Warren E; Merriwether, David A; Raudsepp, Terje

    2014-01-01

    Genome analysis of the alpaca (Lama pacos, LPA) has progressed slowly compared to other domestic species. Here, we report the development of the first comprehensive whole-genome integrated cytogenetic map for the alpaca using fluorescence in situ hybridization (FISH) and CHORI-246 BAC library clones. The map is comprised of 230 linearly ordered markers distributed among all 36 alpaca autosomes and the sex chromosomes. For the first time, markers were assigned to LPA14, 21, 22, 28, and 36. Additionally, 86 genes from 15 alpaca chromosomes were mapped in the dromedary camel (Camelus dromedarius, CDR), demonstrating exceptional synteny and linkage conservation between the 2 camelid genomes. Cytogenetic mapping of 191 protein-coding genes improved and refined the known Zoo-FISH homologies between camelids and humans: we discovered new homologous synteny blocks (HSBs) corresponding to HSA1-LPA/CDR11, HSA4-LPA/CDR31 and HSA7-LPA/CDR36, and revised the location of breakpoints for others. Overall, gene mapping was in good agreement with the Zoo-FISH and revealed remarkable evolutionary conservation of gene order within many human-camelid HSBs. Most importantly, 91 FISH-mapped markers effectively integrated the alpaca whole-genome sequence and the radiation hybrid maps with physical chromosomes, thus facilitating the improvement of the sequence assembly and the discovery of genes of biological importance. PMID:25662411

  8. Clinical and cytogenetic analysis of human anemias from Jammu region of Jammu and Kashmir state

    PubMed Central

    Upma; Kumar, Parvinder; Raina, T. R.; Sharma, Kuldeep; Gupta, Subash

    2010-01-01

    Background: Anemias are the blood disorders characterized by reduction in the number of circulating red blood cells, the amount of hemoglobin, or the volume of packed red cells in blood. Chromosomal aberrations have often been reported from the bone marrow as well as cultured lymphocytes of the anemic patients. Aims: The aims of the study were to find out the commonest type of anemia occurring in the population of Jammu, India and to find out the chromosomal changes involved in the disorder. Material and Methods: Present study has been carried out on the bone marrow samples from 53 clinically diagnosed anemic patients. Cytogenetic study was carried out on slides prepared from these samples. Noncytogenetic factors like age, sex, religion, blood groups, family history of anemia, socioeconomic status, etc. have also been included in the study. Results: Megaloblastic anemia was found to be the commonest type of anemia. Centromere stretching, chromatid breaks, gaps, and elongation of chromosomes were recorded in patients with megaloblastic anemia and combined deficiency anemia. However, structural changes and numerical changes were totally absent. Conclusion: The commonest anemia among the people of Jammu region is megaloblastic anemia and its prevalence is increasing every year. Also, megaloblastic anemia is always associated with reversible cytogenetic changes. PMID:20859508

  9. Cytogenetic and Clinical Assessment of a Family with Treacher Collins Syndrome

    PubMed Central

    Kumar, Manoj; Kumar, Rakesh; Tanwar, Mukesh; Ghose, Supriyo; Kaur, Jasbir; Dada, Rima

    2011-01-01

    Treacher Collins syndrome (TCS) is a rare autosomal dominant disorder characterized by craniofacial deformities. It is the most common type of mandibulofacial dysostosis (MFD). The objective of this study is to do cytogenetic analysis of a TCS family. Physical examination and all available medical records were reviewed. 50 GTG-banded metaphases were analysed to detect any structural or numerical chromosomal abnormality. Downward slanting of palpebral fissures, hypoplasia of zygomatic arch complex, and hypoplasia of mandible were present in all. Cytogenetic findings show interstitial deletion in chromosomes 5(q32-q33) and 3(q23–q25). We report four members of three generations of a family having TCS in a unique way that the deletion has been found in 3q and 5q which has not been reported. Mosaicism of deletion on 5q was detected in all affected members whereas 3q deletion was found only in one member (II.2). This finding may represent a more severe manifestation of the TCS. Thus the evaluation and counselling of the TCS patients should be undertaken with caution. PMID:21765846

  10. Cytogenetic as an Important Tool for Diagnosis and Prognosis for Patients with Hypocellular Primary Myelodysplastic Syndrome

    PubMed Central

    Corrêa de Souza, Daiane; de Souza Fernandez, Cecília; Camargo, Adriana; Apa, Alexandre Gustavo; Sobral da Costa, Elaine; Abdelhay, Eliana; de Souza Fernandez, Teresa

    2014-01-01

    We analyzed cytogenetically 105 patients with hypocellular primary MDS and their clinical implications. The main chromosomal abnormalities found were del(5q)/−5, del(6q)/+6, del(7q)/−7, del(11q), and del(17p). Pediatric patients had a higher frequency of abnormal karyotypes compared with adult patients (P < 0,05). From our patients, 18% showed evolution of the disease. The chromosomal abnormalities presented in the diagnosis of patients who evolved to AML included numerical (−7, +8) and structural del(6q), del(7q), i(7q), t(7;9), i(9q), and del(11q) abnormalities and complex karyotypes. Although the frequency of evolution from hypocellular MDS to AML is low, our results suggest that some chromosomal alterations may play a critical role during this process. We applied the IPSS in our patients because this score system has been proved to be useful for predicting evolution of disease. When we considered the patients according to group 1 (intermediate-1) and group 2 (intermediate-2 and high risk), we showed that group 2 had a high association with respect to the frequency of abnormal karyotypes (P < 0,0001), evolution of disease (P < 0,0001), and mortality (P < 0,001). In fact, the cytogenetic analysis for patients with hypocellular primary MDS is an important tool for diagnosis, prognosis, in clinical decision-making and in follow-up. PMID:25180186

  11. Immunophenotypic, immunocytochemistry, ultrastructural, and cytogenetic characterization of mesenchymal stem cells from equine bone marrow.

    PubMed

    Maia, Leandro; Landim-Alvarenga, Fernanda C; Da Mota, Ligia S L Silveira; De Assis Golim, Marjorie; Laufer-Amorim, Reneé; De Vita, Bruna; Barberini, Danielle Jaqueta; Listoni, Amanda Jeronimo; De Moraes, Carolina Nogueira; Heckler, Marta Cristina Thomas; Amorim, Rogério Martins

    2013-06-01

    The aim of this study was to isolate, culture, and characterize mesenchymal stem cells (MSCs) from horse bone marrow (BM) using the techniques of flow cytometry, immunocytochemistry, cytogenetics, and electron microscopy. Immunophenotypic analysis revealed the presence of MSCs with high expression of the CD90 marker, lower expression of the CD44 marker, and absent expression of the CD34 marker. In assays of differentiation, the positive response to osteogenic (OST), chondrogenic (CDG), and adipogenic (ADP) differentiation signals was observed and characterized by deposition of calcium-rich extracellular matrix (OST), proteoglycans and collagen II (CDG) and intracellular deposition of fat drops (ADP). In immunocytochemical characterization, MSCs were immunopositive for CD44, vimentin, and PCNA, and they were negative for CD13. In the ultrastructural analysis of MSCs, the most outstanding characteristic was the presence of rough endoplasmic reticulum with very dilated cisterns filled with a low electrodensity material. Additionally, MSCs had normal karyotypes (2n = 64) as evidenced by cytogenetic analysis, and aneuploidy in metaphase was not observed. The protocols for isolating, culturing, and characterizing equine MSCs used in this study were shown to be appropriate for the production of a cell population with a good potential for differentiation and without aneuploidy that can be used to study future cellular therapies. PMID:23533133

  12. [Cytogenetic analysis of alloplasmic recombinant lines (H. vulgare)-T. aestivum with unstable fertility and viability].

    PubMed

    Badaeva, E D; Pershina, L A; Bil'danova, L L

    2006-02-01

    Comparative cytogenetic analysis was performed with four alloplasmic recombinant (Hordeum vulgare)-Triticum aestivum lines differing in morphological traits, number of seeds per spike, and seed plumpness. None of the lines displayed introgression of the barley genetic material: the karyotypes included only common wheat chromosomes. Two lines, 79(B) and 79(D), were cytogenetically stable. Plants of lines 79(A) and 79(C) displayed a high frequency of unbalanced chromosome aberrations, including dicentric and polycentric chromosomes, terminal deletions varying in size, acentric fragments, and multiple unidentifiable translocations. Previous studies of the mitochondrial genome showed that the two cytologically unstable lines, which were also unstable in fertility and viability, are characterized by heteroplasmy at the mitochondrial 18S-5S locus (simultaneous presence of barley and wheat fragments). Stable lines 79(B) and 79(D) with normal fertility contained only wheat mitochondrial markers. It was assumed that the substantial instability of the nuclear genome in lines 79(C) and 79(A) was a result of nuclear-cytoplasmic incompatibility and was associated with heteroplasmy, while elimination or considerable reduction of barley material in the mitochondrial genome stabilized the nuclear genome of lines 79(B) and 79(D). In turn, the instability of the nuclear genome was responsible for a decrease in viability and fertility of plants. PMID:16583704

  13. Apigenin ameliorates gamma radiation-induced cytogenetic alterations in cultured human blood lymphocytes.

    PubMed

    Begum, Naziya; Prasad, N Rajendra; Kanimozhi, G; Hasan, Annie Q

    2012-08-30

    The aim of the present study was to assess the protective effect of apigenin, a dietary flavone, against cytogenetic alterations in human peripheral blood lymphocytes (HPBL) induced by Cobalt-60 radiation (3Gy). Results of MTT [3-(4, 5-dimethyl-2-thiaozolyl)-2,5-diphenyl-2H tetrazolium bromide] assay revealed that 37.2μM of apigenin was found to be non-toxic in HPBL. At this dose (37.2μM) of apigenin, the LD(50) radiation dose of HPBL increased from 2.9Gy to 3.4Gy, which resulted in a DMF of 1.17. Apigenin (37.2μM) treatment 1h before irradiation significantly (p<0.05) reduced DNA damage in irradiated HPBL as measured by comet assay (% tail DNA, tail length, tail moment, and olive tail moment). Moreover, apigenin treatment significantly decreased the frequencies of dicentric (DC), acentric fragments (AF), and acentric rings (AR) in irradiated HPBL. Apigenin pretreatment also reduced the radiation-induced CBMN (cytokinesis blocked micronuclei) anomalies such as micronuclei (MNi), nucleoplasmic bridges (NPB) and nuclear buds (NBUD) in HPBL. These results also showed that there was a significant correlation between NPB and DC frequencies and MNi and AF+AR. Treatment with apigenin alone had no significant effect on DNA damage and chromosomal aberrations in HPBL. Thus, the current studies indicate that apigenin protects HPBL from radiation-induced cytogenetic alterations. PMID:22516036

  14. Cytogenetic characterization and genome size of the medicinal plant Catharanthus roseus (L.) G. Don

    PubMed Central

    Guimarães, Guilherme; Cardoso, Luísa; Oliveira, Helena; Santos, Conceição; Duarte, Patrícia; Sottomayor, Mariana

    2012-01-01

    Background and aims Catharanthus roseus is a highly valuable medicinal plant producing several terpenoid indole alkaloids (TIAs) with pharmaceutical applications, including the anticancer agents vinblastine and vincristine. Due to the interest in its TIAs, C. roseus is one of the most extensively studied medicinal plants and has become a model species for the study of plant secondary metabolism. However, very little is known about the cytogenetics and genome size of this species, in spite of their importance for breeding programmes, TIA genetics and emerging genomic research. Therefore, the present paper provides a karyotype description and fluorescence in situ hybridization (FISH) data for C. roseus, as well as a rigorous characterization of its genome size. Methodology The organization of C. roseus chromosomes was characterized using several DNA/chromatin staining techniques and FISH of rDNA. Genome size was investigated by flow cytometry using an optimized methodology. Principal results The C. roseus full chromosome complement of 2n = 16 includes two metacentric, four subtelocentric and two telocentric chromosome pairs, with the presence of a single nucleolus organizer region in chromosome 6. An easy and reliable flow cytometry protocol for nuclear genome analysis of C. roseus was optimized, and the C-value of this species was estimated to be 1C = 0.76 pg, corresponding to 738 Mbp. Conclusions The organization and size of the C. roseus genome were characterized, providing an important basis for future studies of this important medicinal species, including further cytogenetic mapping, genomics, TIA genetics and breeding programmes. PMID:22479673

  15. Contributions to cytogenetics of Plectranthus barbatus Andr. (Lamiaceae): a medicinal plant

    PubMed Central

    Reis, Aryane Campos; Viccini, Lyderson Facio; de Sousa, Saulo Marçal

    2015-01-01

    Abstract Accessions of Plectranthus barbatus (Lamiaceae), a medicinal plant, were investigated using a cytogenetic approach and flow cytometry (FCM). Here, we describe for the first time details of the karyotype including chromosome morphology, physical mapping of GC rich bands (CMA3 banding), as well as the mapping of 45S and 5S rDNA sites. All accessions studied showed karyotypes with 2n = 30 small metacentric and submetacentric chromosomes. The CMA3 banding and fluorescent in situ hybridization techniques revealed coincidence between CMA3 bands and 45S rDNA sites (6 terminal marks) while for the 5S rDNA were observed 4 subterminal marks no coincident with CMA3 marks. For nuclear genome size measurement, the FCM procedure provided histograms with G0/G1 peaks exhibiting CV between 2.0–4.9 and the mean values obtained for the species was 2C = 2.78 pg, with AT% = 61.08 and GC% = 38.92. The cytogenetic data obtained here present new and important information which enables the characterization of Plectranthus barbatus. PMID:26312133

  16. Cytogenetic Diversity of Simple Sequences Repeats in Morphotypes of Brassica rapa ssp. chinensis

    PubMed Central

    Zheng, Jin-shuang; Sun, Cheng-zhen; Zhang, Shu-ning; Hou, Xi-lin; Bonnema, Guusje

    2016-01-01

    A significant fraction of the nuclear DNA of all eukaryotes is comprised of simple sequence repeats (SSRs). Although these sequences are widely used for studying genetic variation, linkage mapping and evolution, little attention had been paid to the chromosomal distribution and cytogenetic diversity of these sequences. In this paper, we report the distribution characterization of mono-, di-, and tri-nucleotide SSRs in Brassica rapa ssp. chinensis. Fluorescence in situ hybridization was used to characterize the cytogenetic diversity of SSRs among morphotypes of B. rapa ssp. chinensis. The proportion of different SSR motifs varied among morphotypes of B. rapa ssp. chinensis, with tri-nucleotide SSRs being more prevalent in the genome of B. rapa ssp. chinensis. We determined the chromosomal locations of mono-, di-, and tri-nucleotide repeat loci. The results showed that the chromosomal distribution of SSRs in the different morphotypes is non-random and motif-dependent, and allowed us to characterize the relative variability in terms of SSR numbers and similar chromosomal distributions in centromeric/peri-centromeric heterochromatin. The differences between SSR repeats with respect to abundance and distribution indicate that SSRs are a driving force in the genomic evolution of B. rapa species. Our results provide a comprehensive view of the SSR sequence distribution and evolution for comparison among morphotypes B. rapa ssp. chinensis. PMID:27507974

  17. Cytogenetically Unrelated Clones in Acute Myeloid Leukemia Showing Different Responses to Chemotherapy

    PubMed Central

    Onozawa, Masahiro; Miyashita, Naohiro; Yokohata, Emi; Yoshida, Miho; Kanaya, Minoru; Kosugi-Kanaya, Mizuha; Takemura, Ryo; Takahashi, Shojiro; Sugita, Junichi; Shigematsu, Akio; Takahata, Mutsumi; Fujisawa, Shinichi; Hashimoto, Daigo; Fujimoto, Katsuya; Endo, Tomoyuki; Kondo, Takeshi; Teshima, Takanori

    2016-01-01

    We report a case of acute myeloid leukemia (AML) with two cytogenetically unrelated clones. The patient was a 45-year-old male who was diagnosed with acute monoblastic leukemia (AMoL). Initial G-band analysis showed 51,XY,+6,+8,inv(9)(p12q13)c,+11,+13,+19[12]/52,idem,+Y[8], but G-band analysis after induction therapy showed 45,XY,-7,inv(9)(p12q13)c[19]/46,XY,inv(9)(p12q13)c[1]. Retrospective FISH analysis revealed a cryptic monosomy 7 clone in the initial AML sample. The clone with multiple trisomies was eliminated after induction therapy and never recurred, but a clone with monosomy 7 was still detected in myelodysplastic marrow with a normal blast percentage. Both clones were successfully eliminated after related peripheral blood stem cell transplantation, but the patient died of relapsed AML with monosomy 7. We concluded that one clone was de novo AMoL with chromosome 6, 8, 11, 13, and 19 trisomy and that the other was acute myeloid leukemia with myelodysplasia-related changes(AML-MRC) with chromosome 7 monosomy showing different responses to chemotherapy. Simultaneous onset of cytogenetically unrelated hematological malignancies that each have a different disease status is a rare phenomenon but is important to diagnose for a correct understanding of the disease status and for establishing an appropriate treatment strategy. PMID:27034857

  18. Cytogenetic damage in lymphocytes of patients undergoing therapy for small cell lung cancer and ovarian carcinoma

    SciTech Connect

    Padjas, Anna; Lesisz, Dominika; Lankoff, Anna; Banasik, Anna; Lisowska, Halina; Bakalarz, Robert; Gozdz, Stanislaw; Wojcik, Andrzej . E-mail: awojcik@pu.kielce.pl

    2005-12-01

    The level of cytogenetic damage in peripheral blood lymphocytes of patients undergoing chemotherapy has been analyzed incisively 20 years ago. The results showed that the highest level of cytogenetic damage was observed at the end of therapy. In recent years, the doses of anticancer drugs were intensified thanks to the discovery of colony stimulating factors. Therefore, it was interesting to analyze the kinetics of micronuclei formation in lymphocytes of patients undergoing modern chemotherapy. The frequencies of micronuclei were measured in lymphocytes of 6 patients with small cell lung cancer treated with a combination of cisplatin and etoposide and 7 patients with ovarian carcinoma treated with a combination of taxol and cisplatin. 3 patients with lung cancer received radiotherapy in addition to chemotherapy. Micronuclei were analyzed in lymphocytes collected before the start of therapy and 1 day before each following cycle of chemotherapy. The micronucleus frequencies were compared with the kinetics of leukocyte counts. The micronucleus frequencies showed an interindividual variability. On average, the frequencies of micronuclei increased during the first half of therapy and declined thereafter, reaching, in some patients with ovarian carcinoma, values below the pre-treatment level. Leukocyte counts decreased strongly at the beginning of therapy with an upward trend at the end. We suggest that the decline of micronuclei was due to repopulation of lymphocytes and acquired drug resistance.

  19. Evidence for structural heterogeneity from molecular cytogenetic analysis of dicentric Robertsonian translocations.

    PubMed Central

    Sullivan, B. A.; Jenkins, L. S.; Karson, E. M.; Leana-Cox, J.; Schwartz, S.

    1996-01-01

    Most Robertsonian translocations are dicentric, suggesting that the location of chromosomal breaks leading to their formation occur in the acrocentric short arm. Previous cytogenetic and molecular cytogenetic studies have shown that few Robertsonian translocations retain ribosomal genes or beta-satellite DNA. Breakpoints in satellite III DNA, specifically between two chromosome 14-specific subfamilies, pTRS-47 and pTRS-63, have been indicated for most of the dicentric 14q21q and 13q14q translocations that have been studied. We have analyzed the structure of 36 dicentric translocations, using several repetitive DNA probes that localize to the acrocentric short arm. The majority of the translocations retained satellite III DNA, while others proved variable in structure. Of 10 14q21q translocations analyzed, satellite III DNA was undetected in 1; 6 retained one satellite III DNA subfamily, pTRS-47; and 3 appeared to contain two 14-specific satellite III DNA sub-families, pTRS-47 and pTRS-63. In 10/11 translocations involving chromosome 15, the presence of satellite III DNA was observed. Our results show that various regions of the acrocentric short arm, and, particularly, satellite III DNA sequences, are involved in the formation of Robertsonian translocations. Images Figure 1 Figure 2 Figure 4 Figure 5 Figure 6 PMID:8659523

  20. Cytogenetic Diversity of Simple Sequences Repeats in Morphotypes of Brassica rapa ssp. chinensis.

    PubMed

    Zheng, Jin-Shuang; Sun, Cheng-Zhen; Zhang, Shu-Ning; Hou, Xi-Lin; Bonnema, Guusje

    2016-01-01

    A significant fraction of the nuclear DNA of all eukaryotes is comprised of simple sequence repeats (SSRs). Although these sequences are widely used for studying genetic variation, linkage mapping and evolution, little attention had been paid to the chromosomal distribution and cytogenetic diversity of these sequences. In this paper, we report the distribution characterization of mono-, di-, and tri-nucleotide SSRs in Brassica rapa ssp. chinensis. Fluorescence in situ hybridization was used to characterize the cytogenetic diversity of SSRs among morphotypes of B. rapa ssp. chinensis. The proportion of different SSR motifs varied among morphotypes of B. rapa ssp. chinensis, with tri-nucleotide SSRs being more prevalent in the genome of B. rapa ssp. chinensis. We determined the chromosomal locations of mono-, di-, and tri-nucleotide repeat loci. The results showed that the chromosomal distribution of SSRs in the different morphotypes is non-random and motif-dependent, and allowed us to characterize the relative variability in terms of SSR numbers and similar chromosomal distributions in centromeric/peri-centromeric heterochromatin. The differences between SSR repeats with respect to abundance and distribution indicate that SSRs are a driving force in the genomic evolution of B. rapa species. Our results provide a comprehensive view of the SSR sequence distribution and evolution for comparison among morphotypes B. rapa ssp. chinensis. PMID:27507974

  1. Modified cIg-FISH protocol for multiple myeloma in routine cytogenetic laboratory practice.

    PubMed

    Gole, Leena; Lin, Adeline; Chua, Constance; Chng, Wee Joo

    2014-01-01

    The International Myeloma Working Group recommends that fluorescence in situ hybridization (FISH) be performed on specifically identified plasma cells (PC). This is because chromosomal abnormalities are not frequently detected by traditional karyotyping due to the low proliferative rate of PC in multiple myeloma (MM). Conventional FISH enhances the sensitivity but lacks the specificity, as it does not distinguish PC from other hematopoetic cells. To fulfill this recommendation, PC need to be selected either by flow cytometry or immunomagnetic bead-based PC sorting or by concomitant labeling of the cytoplasmic immunoglobulin light chain, which allows for unambiguous identification. These techniques require expertise, time, and funding and are not easily incorporated into the routine workflow of the cytogenetic laboratory. We have modified and refined the technique using fixed cell pellets to achieve nicely separated and easily identifiable PC. With immunostaining and subsequent FISH (i.e., cytoplasmic immunoglobulin FISH, cIg-FISH), this technique can be easily incorporated into every cytogenetic laboratory. Twenty samples from patients with MM were subjected to routine FISH, cIg-FISH, and chromosomal karyotyping and the results were compared. Three FISH probes, which enabled detection of the t(4;14), t(14;16) and deletion of TP53, were used to validate this modified technique successfully. PMID:24485403

  2. Cytogenetic analysis of Aegilops chromosomes, potentially usable in triticale (X Triticosecale Witt.) breeding.

    PubMed

    Kwiatek, M; Wiśniewska, H; Apolinarska, B

    2013-05-01

    Chromosome identification using fluorescence in situ hybridization (FISH) is widely used in cytogenetic research. It is a diagnostic tool helpful in chromosome identification. It can also be used to characterize alien introgressions, when exercised in a combination with genomic in situ hybridization (GISH). This work aims to find chromosome identification of Aegilops species and Aegilops × Secale amphiploids, which can be used in cereal breeding as a source of favourable agronomic traits. Four diploid and two tetraploid Aegilops species and three Aegilops × Secale hybrids were analysed using FISH with pSc119.2, pAs1, 5S rDNA and 25S rDNA clones to differentiate the U-, M-, S(sh)- and D-subgenome chromosomes of Aegilops genus. Additionally, GISH for chromosome categorization was carried out. Differences in the hybridization patterns allowed to identify all U-, M-, S(sh)- and D-subgenome chromosomes. Some differences in localization of the rDNA, pSc119.2 and pAs1 sequences between analogue subgenomes in diploid and tetraploid species and Aegilops × Secale hybrids were detected. The hybridization pattern of the M and S genome was more variable than that of the U and D genome. An importance of the cytogenetic markers in plant breeding and their possible role in chromosome structure, function and evolution is discussed. PMID:23378244

  3. Cytogenetic study of heptapterids (Teleostei, Siluriformes) with particular respect to the Nemuroglanis subclade.

    PubMed

    Kantek, Daniel Luis Zanella; Moreira Peres, Wellington Adriano; Moreira-Filho, Orlando

    2015-01-01

    The catfish family Heptapteridae (order Siluriformes) is endemic to the Neotropics and is one of the most common of the fish families in small bodies of water. Although over 200 species have been identified in this family, very few have been characterized cytogenetically. Here, we analyze the chromosome genomes of four species of Heptapteridae: Cetopsorhamdiaiheringi (Schubart & Gomes, 1959), 2n = 58, comprising 28 metacentric (m) + 26 submetacentric (sm) + 4 subtelomeric (st) chromosomes; Pimelodellavittata (Lütken, 1874), 2n = 46, comprising 16m + 22sm + 8st; Rhamdiapropequelen (Quoy & Gaimard, 1824), 2n = 58 comprising 26m + 16sm + 14st + 2 acrocentric; and Rhamdiopsispropemicrocephala (Lütken, 1874), 2n = 56, comprising 12m + 30sm + 14st. The nucleolus organizer regions (NORs) were located in a single chromosome pair in all species. The two species that belonged to the subclade Nemuroglanis, Cetopsorhamdiaiheringi and Rhamdiapropequelen, had a diploid chromosome number of 58 and an interstitial NOR adjacent to a C(+) block located on one of the larger chromosome pairs in the complement. Our results from conventional cytogenetic techniques in combination with FISH using 18S and 5S rDNA probes corroborated the taxonomical hypothesis for the formation of the Nemuroglanis subclade. PMID:25893072

  4. Cytogenetic study of heptapterids (Teleostei, Siluriformes) with particular respect to the Nemuroglanis subclade

    PubMed Central

    Kantek, Daniel Luis Zanella; Moreira Peres, Wellington Adriano; Moreira-Filho, Orlando

    2015-01-01

    Abstract The catfish family Heptapteridae (order Siluriformes) is endemic to the Neotropics and is one of the most common of the fish families in small bodies of water. Although over 200 species have been identified in this family, very few have been characterized cytogenetically. Here, we analyze the chromosome genomes of four species of Heptapteridae: Cetopsorhamdia iheringi (Schubart & Gomes, 1959), 2n = 58, comprising 28 metacentric (m) + 26 submetacentric (sm) + 4 subtelomeric (st) chromosomes; Pimelodella vittata (Lütken, 1874), 2n = 46, comprising 16m + 22sm + 8st; Rhamdia prope quelen (Quoy & Gaimard, 1824), 2n = 58 comprising 26m + 16sm + 14st + 2 acrocentric; and Rhamdiopsis prope microcephala (Lütken, 1874), 2n = 56, comprising 12m + 30sm + 14st. The nucleolus organizer regions (NORs) were located in a single chromosome pair in all species. The two species that belonged to the subclade Nemuroglanis, Cetopsorhamdia iheringi and Rhamdia prope quelen, had a diploid chromosome number of 58 and an interstitial NOR adjacent to a C+ block located on one of the larger chromosome pairs in the complement. Our results from conventional cytogenetic techniques in combination with FISH using 18S and 5S rDNA probes corroborated the taxonomical hypothesis for the formation of the Nemuroglanis subclade. PMID:25893072

  5. Study on the cytogenetic changes induced by benzene and hydroquinone in human lymphocytes.

    PubMed

    Peng, D; Jiaxing, W; Chunhui, H; Weiyi, P; Xiaomin, W

    2012-04-01

    Benzene (BN) is a prototypical hematotoxicant, genotoxic carcinogen, and ubiquitous environmental pollutant. Although the molecular mechanisms of BN-induced cytotoxicity and genotoxic damage are poorly understood in humans, previous studies suggested that bioactivated BN metabolites are capable of oxidative stress, cell cycle arrest, apoptosis, and DNA damage. The objective of the current study was to investigate the BN-induced cytogenetic changes and underlying mechanisms based on these hypotheses. Peripheral blood lymphocytes (PBLs) might be the targets for BN-induced cytotoxicity and genotoxicity, and therefore DNA damage responses of PBLs after exposure to different concentrations of BN (0.25, 3.5, 50 μmol/L) or BN metabolite, hydroquinone (HQ; 50, 150, 450 μmol/L) were studied in vitro. Microculture tetrazolium assay, flow cytometry, 2',7'-dichlorodihydrofluorescein-diacetate assay, comet assay, micronuclei assay, and attenuated total reflectance microspectroscope were chosen for this study. Based on the results, we reached the conclusion that different concentrations of BN or HQ significantly inhibited cell growth, induced the arrest of S phase and G2/M phase, and increased late apoptosis in a concentration-dependent manner. Furthermore, evidence was also provided to support the conclusion that BN and HQ induced DNA strand breaks and chromosomal mutations in PBL, which indicated the genotoxicity of BN and HQ. Current evidence has indicated that multiple mechanisms including dysfunction of cell cycle, programmed cell death, oxidative stress, and DNA lesions are likely to contribute to BN-induced cytogenetic changes. PMID:22297702

  6. Cytogenetic damage in workers from a coal-fired power plant.

    PubMed

    Celik, Mustafa; Donbak, Lale; Unal, Fatma; Yüzbasioglu, Deniz; Aksoy, Hüseyin; Yilmaz, Serkan

    2007-03-01

    The aim of this study was to investigate the genotoxic risk to workers occupationally exposed to coal combustion products in Afsin-Elbistan A power plant, located in south-eastern Turkey. We analysed chromosomal aberrations (CAs), polyploidy, sister-chromatid exchanges (SCEs), and micronuclei (MN) in 48 male workers without a history of smoking, tobacco chewing, or alcohol consumption. The results were compared with a control group of 30 healthy male individuals without exposure to any known genotoxic agents. The mean frequencies of CA, polyploidy, SCEs (P<0.01), and MN (P<0.05) were significantly higher in workers than in the control group, by the Mann-Whitney U-test. Spearman's rho correlation analysis revealed a significant increase in the frequency of CA and MN with increasing years of exposure (P<0.05). However, there was no significant effect of age on the cytogenetic markers analysed in both groups (P>0.05). The data obtained from this study clearly showed chromosomal hazard in the peripheral lymphocytes of workers exposed to coal combustion products in Afsin-Elbistan A power plant for several years. This cytogenetic damage might be attributed to the cumulative effects of several substances due to chemical complexity of the coal ash and gaseous emissions rather than a specific substance. PMID:17178253

  7. Karyotypic conservatism in five species of Prochilodus (Characiformes, Prochilodontidae) disclosed by cytogenetic markers

    PubMed Central

    Voltolin, Tatiana Aparecida; Penitente, Manolo; Mendonça, Bruna Bueno; Senhorini, José Augusto; Foresti, Fausto; Porto-Foresti, Fábio

    2013-01-01

    The family Prochilodontidae is considered a group with well conserved chromosomes characterized by their number, morphology and banding patterns. Thence, our study aimed at accomplishing a cytogenetic analysis with conventional methods (Giemsa staining, silver staining of the nucleolus organizer regions-AgNOR, and C-banding) and fluorescence in situ hybridization (FISH) with 18S and 5S ribosomal DNA probes in five species of the Prochilodus genus (Prochilodus argenteus, Prochilodus brevis, Prochilodus costatus, Prochilodus lineatus and Prochilodus nigricans) collected from different Brazilian hydrographic basins. The results revealed conservatism in chromosome number, morphology, AgNORs 18S and 5S rDNAs location and constitutive heterochromatin distribution patterns. The minor differences observed in this work, such as an Ag-NOR on a P. argenteus chromosome and a distinct C-banding pattern in P. lineatus, are not sufficient to question the conservatism described for this group. Future work using repetitive DNA sequences as probes for FISH will be interesting to further test the cytogenetic conservatism in Prochilodus. PMID:24130441

  8. Cytogenetic monitoring of coal workers and patients with coal workers' pneumoconiosis in Turkey

    SciTech Connect

    Ulker, O.C.; Ustundag, A.; Duydu, Y.; Yucesoy, B.; Karakaya, A.

    2008-04-15

    Occupational exposure to coal dust causes coal workers' pneumoconiosis (CWP), which is a chronic inflammatory and fibrotic lung disease. Recently, chronic inflammation has been accepted as a crucial factor in the pathogenesis of neoplasia. The chronic inflammation provides dynamic setting for oxidative stress and formation of free radicals. Interaction of reactive oxygen species (ROS) with DNA augments the likelihood of DNA structural and transcriptional errors. The purpose of this study was to investigate the genotoxic risk in pneumoconiotic patients and in those with occupational exposure to coal dust. Therefore, sister chromatid exchange (SCE) and micronucleus (MN) tests were performed in Turkish CWP patients, coal workers, and an unexposed control group. Both SCE and MN frequencies in CWP patients were found significantly higher than in coal worker and unexposed groups. There were no differences between SCE and MN frequencies of coal worker and unexposed groups. On the other hand, no correlation between SCE frequency, duration of exposure, and age was observed in all three groups. There was also no effect of smoking on the frequencies of SCE and MN in the groups. Based on these results, it might be suggested that development of CWP leads to a significant induction of cytogenetic damage in peripheral lymphocytes of CWP patients. This is the first report on CWP patients with elevated cytogenetic endpoints. Further, a larger follow-up study is warranted.

  9. Highly distinct chromosomal structures in cowpea (Vigna unguiculata), as revealed by molecular cytogenetic analysis.

    PubMed

    Iwata-Otsubo, Aiko; Lin, Jer-Young; Gill, Navdeep; Jackson, Scott A

    2016-05-01

    Cowpea (Vigna unguiculata (L.) Walp) is an important legume, particularly in developing countries. However, little is known about its genome or chromosome structure. We used molecular cytogenetics to characterize the structure of pachytene chromosomes to advance our knowledge of chromosome and genome organization of cowpea. Our data showed that cowpea has highly distinct chromosomal structures that are cytologically visible as brightly DAPI-stained heterochromatic regions. Analysis of the repetitive fraction of the cowpea genome present at centromeric and pericentromeric regions confirmed that two retrotransposons are major components of pericentromeric regions and that a 455-bp tandem repeat is found at seven out of 11 centromere pairs in cowpea. These repeats likely evolved after the divergence of cowpea from common bean and form chromosomal structure unique to cowpea. The integration of cowpea genetic and physical chromosome maps reveals potential regions of suppressed recombination due to condensed heterochromatin and a lack of pairing in a few chromosomal termini. This study provides fundamental knowledge on cowpea chromosome structure and molecular cytogenetics tools for further chromosome studies. PMID:26758200

  10. Cytogenetic characterization of low-dose hyper-radiosensitivity in Cobalt-60 irradiated human lymphoblastoid cells.

    PubMed

    Joshi, Gnanada S; Joiner, Michael C; Tucker, James D

    2014-12-01

    The dose-effect relationships of cells exposed to ionizing radiation are frequently described by linear quadratic (LQ) models over an extended dose range. However, many mammalian cell lines, when acutely irradiated in G2 at doses ≤0.3Gy, show hyper-radiosensitivity (HRS) as measured by reduced clonogenic cell survival, thereby indicating greater cell lethality than is predicted by extrapolation from high-dose responses. We therefore hypothesized that the cytogenetic response in G2 cells to low doses would also be steeper than predicted by LQ extrapolation from high doses. We tested our hypothesis by exposing four normal human lymphoblastoid cell lines to 0-400cGy of Cobalt-60 gamma radiation. The cytokinesis block micronucleus assay was used to determine the frequencies of micronuclei and nucleoplasmic bridges. To characterize the dependence of the cytogenetic damage on dose, univariate and multivariate regression analyses were used to compare the responses in the low- (HRS) and high-dose response regions. Our data indicate that the slope of the response for all four cell lines at ≤20cGy during G2 is greater than predicted by an LQ extrapolation from the high-dose responses for both micronuclei and bridges. These results suggest that the biological consequences of low-dose exposures could be underestimated and may not provide accurate risk assessments following such exposures. PMID:25771872

  11. ASXL1 and DNMT3A mutation in a cytogenetically normal B3 thymoma.

    PubMed

    Belani, R; Oliveira, G; Erikson, G A; Ra, S; Schechter, M S; Lee, J K; Shipman, W J; Haaser, S M; Torkamani, A

    2014-01-01

    The molecular drivers of thymoma are poorly understood. Outside of the identification of rarely occurring epidermal growth factor receptor and v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog mutations via candidate gene sequencing, mutations in common cancer genes have yet to be observed. Only a single thymoma genome sequence has been previously reported, with no mutations in known cancer genes identified. Thus, we attempted to identify somatic driver mutations in a cytogenetically normal thymoma. A stage IVB type B3 thymoma from a 47-year-old male of Asian descent with no history of myasthenia gravis or other autoimmune condition was genomically evaluated. Exome sequencing and low-pass whole-genome sequencing was performed to identify somatic point mutations, copy number changes and structural variants. Mutations in known tumor suppressors DNMT3A (p.G728D) and ASXL1 (p.E657fs), consistent with mutations of known consequence in acute myeloid leukemia, were identified. Contrary to a previous report, this finding suggests the genetic etiology of thymomas may not be fundamentally distinct from other tumor types. Rather, these findings suggest that further sequencing of cytogenetically normal thymoma samples should reveal the specific molecular drivers of thymoma. PMID:25000259

  12. Cytogenetic findings on shoe workers exposed long-term to benzene.

    PubMed Central

    Tunca, B T; Egeli, U

    1996-01-01

    Cytogenetic analysis of peripheral blood lymphocytes was performed to detect cytogenetical alterations in 58 shoe workers (57 male and 1 female) who had been exposed to particular mutagenic or carcinogenic agents and in 20 subjects selected from the general population as a control group. Frequencies of damaged cells, including gaps, breaks, and rearrangements (acentric fragment, deletion, translocations) were scored for both groups. The incidence of chromosomal aberrations (particularly chromatid gaps and breaks) in the study group was significantly higher than in the control group. No effects of smoking were observed and breaks alone were found to be influenced by alcohol consumption. No significant correlation was detected between the working period in the group exposed to benzene and frequency of chromosomal aberrations. Benzene content was determined to be between 0 and 28.5% in eight kinds of glues studied by fractional distillation. Hexane content ranged between 0 and 68.35% using the same method. This study indicated that the content of benzene and hexane in the glues are above normal limits. PMID:9118912

  13. DNA repair in the variable platyfish (Xiphophorus variatus) irradiated in vivo with ultraviolet B light.

    PubMed

    Mitchell, D L; Scoggins, J T; Morizot, D C

    1993-09-01

    Dark- and light-dependent DNA repair processes were studied in vivo in the variable platyfish, Xiphophorus variatus. Excision (dark) repair of the (6-4) photoproduct was more efficient than that of the cyclobutane dimer with approximately 70% of the (6-4) photoproducts removed by 24 h post-UVB radiation compared to approximately 30% of the cyclobutane dimers. Exposure to photoreactivating light resulted in rapid loss of most (> 90%) of the cyclobutane dimers and increased excision repair of the (6-4) photoproduct. Preexposure to photoreactivating light 8 h prior to UVB radiation increased the rate of photoreactivation two-fold. PMID:8234482

  14. Repair of a fractured implant overdenture gold bar: A clinical and laboratory technique report

    PubMed Central

    Vohra, Fahim; Al Fawaz, Amani

    2013-01-01

    This clinical report explains a convenient, efficient, yet effective alternative for management of fractured substructure cast bars for implant-retained overdentures. The technique allows the fracture to be repaired at low cost and short time without remaking the substructure and the denture and further allowing the patient to keep their denture. The report sketches the clinical and laboratory procedures involved in the repair. PMID:24926222

  15. Breaking bad: The mutagenic effect of DNA repair.

    PubMed

    Chen, Jia; Furano, Anthony V

    2015-08-01

    Species survival depends on the faithful replication of genetic information, which is continually monitored and maintained by DNA repair pathways that correct replication errors and the thousands of lesions that arise daily from the inherent chemical lability of DNA and the effects of genotoxic agents. Nonetheless, neutrally evolving DNA (not under purifying selection) accumulates base substitutions with time (the neutral mutation rate). Thus, repair processes are not 100% efficient. The neutral mutation rate varies both between and within chromosomes. For example it is 10-50 fold higher at CpGs than at non-CpG positions. Interestingly, the neutral mutation rate at non-CpG sites is positively correlated with CpG content. Although the basis of this correlation was not immediately apparent, some bioinformatic results were consistent with the induction of non-CpG mutations by DNA repair at flanking CpG sites. Recent studies with a model system showed that in vivo repair of preformed lesions (mismatches, abasic sites, single stranded nicks) can in fact induce mutations in flanking DNA. Mismatch repair (MMR) is an essential component for repair-induced mutations, which can occur as distant as 5 kb from the introduced lesions. Most, but not all, mutations involved the C of TpCpN (G of NpGpA) which is the target sequence of the C-preferring single-stranded DNA specific APOBEC deaminases. APOBEC-mediated mutations are not limited to our model system: Recent studies by others showed that some tumors harbor mutations with the same signature, as can intermediates in RNA-guided endonuclease-mediated genome editing. APOBEC deaminases participate in normal physiological functions such as generating mutations that inactivate viruses or endogenous retrotransposons, or that enhance immunoglobulin diversity in B cells. The recruitment of normally physiological error-prone processes during DNA repair would have important implications for disease, aging and evolution. This perspective

  16. Endovascular Repair of Thoracic Aortic Aneurysms

    PubMed Central

    Findeiss, Laura K.; Cody, Michael E.

    2011-01-01

    Degenerative aneurysms of the thoracic aorta are increasing in prevalence; open repair of descending thoracic aortic aneurysms is associated with high rates of morbidity and mortality. Repair of isolated descending thoracic aortic aneurysms using stent grafts was introduced in 1995, and in an anatomically suitable subgroup of patients with thoracic aortic aneurysm, repair with endovascular stent graft provides favorable outcomes, with decreased perioperative morbidity and mortality relative to open repair. The cornerstones of successful thoracic endovascular aneurysm repair are appropriate patient selection, thorough preprocedural planning, and cautious procedural execution, the elements of which are discussed here. PMID:22379281

  17. Nonhomologous end-joining repair plays a more important role than homologous recombination repair in defining radiosensitivity after exposure to high-LET radiation.

    PubMed

    Takahashi, Akihisa; Kubo, Makoto; Ma, Hongyu; Nakagawa, Akiko; Yoshida, Yukari; Isono, Mayu; Kanai, Tatsuaki; Ohno, Tatsuya; Furusawa, Yoshiya; Funayama, Tomoo; Kobayashi, Yasuhiko; Nakano, Takashi

    2014-09-01

    DNA double-strand breaks (DSBs) induced by ionizing radiation pose a major threat to cell survival. The cell can respond to the presence of DSBs through two major repair pathways: homologous recombination (HR) and nonhomologous end joining (NHEJ). Higher levels of cell death are induced by high-linear energy transfer (LET) radiation when compared to low-LET radiation, even at the same physical doses, due to less effective and efficient DNA repair. To clarify whether high-LET radiation inhibits all repair pathways or specifically one repair pathway, studies were designed to examine the effects of radiation with different LET values on DNA DSB repair and radiosensitivity. Embryonic fibroblasts bearing repair gene (NHEJ-related Lig4 and/or HR-related Rad54) knockouts (KO) were used and their responses were compared to wild-type cells. The cells were exposed to X rays, spread-out Bragg peak (SOBP) carbon ion beams as well as with carbon, iron, neon and argon ions. Cell survival was measured with colony-forming assays. The sensitization enhancement ratio (SER) values were calculated using the 10% survival dose of wild-type cells and repair-deficient cells. Cellular radiosensitivity was listed in descending order: double-KO cells > Lig4-KO cells > Rad54-KO cells > wild-type cells. Although Rad54-KO cells had an almost constant SER value, Lig4-KO cells showed a high-SER value when compared to Rad54-KO cells, even with increasing LET values. These results suggest that with carbon-ion therapy, targeting NHEJ repair yields higher radiosensitivity than targeting homologous recombination repair. PMID:25117625

  18. 40 CFR 798.5500 - Differential growth inhibition of repair proficient and repair deficient bacteria: “Bacterial DNA...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... recommendations as specified under 40 CFR part 792, subpart J the following specific information should be... repair proficient and repair deficient bacteria: âBacterial DNA damage or repair tests.â 798.5500 Section... inhibition of repair proficient and repair deficient bacteria: “Bacterial DNA damage or repair tests.”...

  19. 40 CFR 798.5500 - Differential growth inhibition of repair proficient and repair deficient bacteria: “Bacterial DNA...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... recommendations as specified under 40 CFR part 792, subpart J the following specific information should be... repair proficient and repair deficient bacteria: âBacterial DNA damage or repair tests.â 798.5500 Section... inhibition of repair proficient and repair deficient bacteria: “Bacterial DNA damage or repair tests.”...

  20. 40 CFR 798.5500 - Differential growth inhibition of repair proficient and repair deficient bacteria: “Bacterial DNA...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... recommendations as specified under 40 CFR part 792, subpart J the following specific information should be... repair proficient and repair deficient bacteria: âBacterial DNA damage or repair tests.â 798.5500 Section... inhibition of repair proficient and repair deficient bacteria: “Bacterial DNA damage or repair tests.”...