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| Registros recuperados: 8,210 | |
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| Viana,José Marcelo Soriano. |
| It was studied the parametric restrictions of the diallel analysis model of Griffing, method 2 (parents and F1 generations) and model 1 (fixed), in order to address the questions: i) does the statistical model need to be restricted? ii) do the restrictions satisfy the genetic parameter values? and iii) do they make the analysis and interpretation easier? Objectively, these questions can be answered as: i) yes, ii) not all of them, and iii) the analysis is easier, but the interpretation is the same as in the model with restrictions that satisfy the parameter values. The main conclusions were that: the statistical models for combining ability analysis are necessarily restricted; in the Griffing model (method 2, model 1), the restrictions relative to the... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572000000400029 |
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| Vargas,Carmen R.; Barschak,Alethéa G.; Coelho,Daniella M.; Furlanetto,Vivian; Souza,Carolina F.M. de; Karam,Simone M.; Jardim,Laura; Wajner,Moacir; Giugliani,Roberto. |
| X-Linked adrenoleukodystrophy (X-ALD) is a hereditary disorder of the peroxisomal metabolism biochemically characterized by the accumulation of very long chain fatty acids (VLCFA) in tissues and biological fluids. The major accumulated acids are hexacosanoic acid (C26:0) and tetracosanoic acid (C24:0). The disorder is characterized clinically by central and peripheral demyelination and adrenal insufficiency closely related to the accumulation of fatty acids. The incidence of X-ALD is estimated to be 1:25,000 males. At least six phenotypes can be distinguished. The most common phenotypes are childhood cerebral ALD and adrenomyeloneuropathy (AMN). The recommended therapy consists of the use of the glyceroltrioleate/glyceroltrierucate (GTO/GTE) mixture, known... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572000000400001 |
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| Seoane,A.I.; Güerci,A.M.; Dulout,F.N.. |
| The induction of aneuploidy by physical and chemical agents using different test systems was evaluated. The effect of X-rays, caffeine, acetaldehyde, ethanol, diethylstilbestrol, propionaldehyde, and chloral hydrate was studied by chromosome counting in Chinese hamster embryonic diploid cells. Aneugenic ability of cadmium chloride, cadmium sulfate, potassium dichromate, chromium chloride, nickel chloride, and nickel sulfate was assessed by means of anaphase-telophase analysis in Chinese hamster ovary cells. Chromosome counting in human fibroblasts (MRC-5 cell line) was employed to evaluate the effect of cacodilic acid, cadmium chloride, cadmium sulfate, and potassium dichromate. Finally, the induction of kinetochore-positive and kinetochore negative... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572000000400054 |
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| Javier Tovar,Francisco; Silva,Luiz Antônio Ferreira da; Rodarte,Renato Santos; Leoncini,Orilio. |
| Ribosomal DNA (rDNA) is a multigenic family composed of one or more clusters of repeating units (RU). Each unit consists of highly conserved sequences codifying 18S, 5.8S and 28S rRNA genes intercalated with poorly conserved regulatory sequences between species. In this work, we analyzed the rDNA of Drosophila arizonae, a member of the mulleri complex (Repleta group). Using genomic restriction patterns, cloning and mapping of some representative rDNA fragments, we were able to construct a representative restriction map. RU in this species are 13.5-14 kb long, restriction sites are completely conserved compared with other drosophilids and the rDNA has an R1 retrotransposable element in some RU. We were unable to detect R2 elements in this species. |
| Tipo: Info:eu-repo/semantics/other |
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| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572000000200015 |
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| Bevilacqua,Roberta A.U.; Corvello,Cassandra M.; Duarte,Ana Paula; Simpson,Andrew J.G.. |
| A crucial role for the adenomatous polyposis colonic (APC) gene in colorectal carcinogenesis has been conclusively established, but, the role of APC in gastric tumors remains controversial. APC mutations have been detected at a relatively high frequency in gastric tumors of Japanese patients, yet such mutations have been reported to be extremely rare in British patients and patients from north-central-Italy. We here report the analysis of 40 primary sporadic gastric adenocarcinomas and 35 primary sporadic colon adenocarcinomas (from patients resident in São Paulo, Brazil), for mutations in the APC gene between codons 686 and 1693 using the protein truncation test. Although 19 truncating mutations were detected in 35 colon adenocarcinomas (54.2%) none were... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572000000200001 |
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| Augustin,Lizete; Federizzi,Luiz Carlos; Sereno,Maria Jane Cruz de Melo. |
| Immature embryo-derived somaclones regenerated from genotypes UPF 12, UPF 89S080 and UFRGS 7 were analyzed for eight agronomic traits and two enzymatic systems in order to evaluate the potential of tissue cultures to induce genetic variability in oats (Avena sativa L.). Some somaclones were also analyzed cytogenetically. Agronomic traits were evaluated in the field for all somaclones in 1993 and 1994. Bi-directional variation (P < 0.05) was detected for all characteristics, and the average frequency of variation observed in 1993 in somaclones from genotypes UPF 12 and UPF 89S080 was 35.2%. Variation observed for agronomic characteristics was heritable through two generations. Isoenzymatic analysis showed variation for both enzymatic systems in four... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572000000300025 |
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| Jeppesen,Peter. |
| Control of the genetic information encoded by DNA in mammalian chromosomes is mediated by proteins, some of which are only transiently attached, although others are intrinsically associated with nucleic acid in the complex mixture known as chromatin. Chromatin-associated proteins range from the ubiquitous and abundant histones down to the most specific and rare of transcription factors. Although many chromatin proteins are probably excluded from highly condensed mitotic chromosomes, a number are retained throughout the cell cycle and can be detected on chromosomes in metaphase spreads. Comparing the distribution of a chromosomal protein with known cytogenetic markers on metaphase chromosomes can provide an important and potentially highly informative first... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572000000400059 |
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| Parks,K.R.; Eisen,E.J.; Murray,J.D.. |
| The objective of the present study was to compare correlated responses in liver, spleen, kidney, heart and testis absolute weights and as a percentage of 8-week body weight following selection for large 8-week body weight in twice-replicated nontransgenic and transgene-carrier lines of mice from two genetic backgrounds. The transgene was an ovine metallothionein 1a-ovine growth hormone (oMt1a-oGH) construct, which was activated by adding 25 mM ZnSO4 to the drinking water. Lines NM and NC were nontransgenic lines derived from a high-growth and randomly selected background, respectively. Lines TM and TC were transgene-carrier lines formed from the respective genetic backgrounds. Line CC was a nontransgenic control from the randomly selected background. At... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572000000400011 |
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| Silva,Juliana da; Freitas,Thales R.O. de; Marinho,Jorge R.; Speit,Günter; Erdtmann,Bernardo. |
| The main advantages of single-cell gel electrophoresis (SCG) are its applicability to any eukaryotic organism and cell type, its low cost and the short time required to obtain results. These properties make the SCG assay particularly useful in screening for environmental genotoxicity. The present study describes a modified version of this technique for use in field work with native rodents and examines some factors which influence the outcome of the assay. Wild rodents (Ctenomys torquatus, "tuco-tuco") from a region close to a strip coal mine and from a region with no coal mines were used. Animals from the coal mining region had significantly more DNA damage than those from the control area. The use of this SCG technique for direct sampling in the field... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572000000100042 |
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| Saraswathy,Radha; Natarajan,A.T.. |
| Blood lymphocytes from xeroderma pigmentosum (XP) and Fanconi anemia (FA) patients were assessed for their sensitivity to ionizing radiation by estimating the frequency of X-ray (1 and 2 Gy)-induced chromosome aberrations (CA). The frequencies of aberrations in the whole genome were estimated in Giemsa-stained preparations of lymphocytes irradiated at G0 or G2 stages. The frequencies of translocations and dicentrics involving chromosomes 1 and 3 as well as the X-chromosome were determined in slides stained by fluorescence in situ hybridization (FISH) technique. An increase in all types of CA was observed in XP and FA lymphocytes irradiated at G0 when compared to controls. The frequency of dicentrics and rings was 6 to 27% higher (at 1 and 2 Gy) in XP... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572000000400031 |
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| Bastos,Reginaldo Gaspar; Federizzi,Joreci; Deschamps,João Carlos; Cardellino,Ricardo; Dellagostin,Odir Antônio. |
| The swine stress gene (hal) in recessive homozygotes (nn) leads to porcine stress syndrome (PSS), and is associated with pale, soft, exudative pork (PSE). In heterozygosis (Nn) it is linked to poor carcass quality. A total of 179 pigs (86 Large White, 69 Landrace, 12 Duroc and 12 Pietrain) were characterized as normal homozygotes (NN), heterozygotes or recessive homozygotes following amplification of a target region of the hal gene using the polymerase chain reaction (PCR), followed by a restriction endonuclease assay. Plucked hair was used as a source of genomic DNA. The resulting PCR was digested with the restriction enzyme CfoI, followed by agarose gel electrophoresis. Of 179 animals tested, 70% were NN, 28% were Nn, and 2% were nn. The frequency of... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572000000400018 |
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| Grisolia,Cesar Koppe; Cordeiro,Célia Maria Torres. |
| Fish are often used for screening genotoxicity of water. For such programs, a knowledge of the sensitivity to clastogens, spontaneous micronucleus frequency and cell cycle kinetics of the target tissue is necessary. To investigate the pattern of inter-specific sensitivity to micronucleus induction three species of fish, Tilapia rendalli, Oreochromis niloticus and Cyprinus carpio, were exposed to the clastogens bleomycin (BLM), cyclophosphamide (CP), 5-fluorouracil (5-FU), and mitomycin C (MMC). The binucleate/mononucleate ratio in peripheral erythrocytes exposed to cytochalasin B was also used to evaluate the time-dependent response of micronucleus formation during hematopoesis in the kidney and the micronucleus peak in peripheral erythrocytes.... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 2000 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47572000000100041 |
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| Registros recuperados: 8,210 | |
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