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| Registros recuperados: 6.820 | |
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| Franco,Rendrik F.; Elion,Jacques; Santos,Sidney E.B.; Araújo,Amélia G.; Tavella,Marli H.; Zago,Marco A.. |
| Inherited resistance to activated protein C caused by the factor V Leiden (FVL) mutation is the most common genetic cause of venous thrombosis yet described, being found in 20-60% of patients with venous thrombophilia. A relationship between the FVL mutation and an increased predisposition to arterial thrombosis in young women was recently reported. We assessed the prevalence of the FVL mutation in 440 individuals (880 chromosomes) belonging to four different ethnic groups: Caucasians, African Blacks, Asians and Amerindians. PCR amplification followed by MnlI digestion was employed to define the genotype. The FVL mutation was found in a heterozygous state in four out of 152 Whites (2.6%), one out of 151 Amerindians (0.6%), and was absent among 97 African... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000200001 |
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| Alzate-Marin,Ana Lilia; Barros,Everaldo Gonçalves de; Moreira,Maurílio Alves. |
| Colletotrichum lindemuthianum, the causal agent of anthracnose in the common bean (Phaseolus vulgaris L.), displays a high level of virulence diversity, which explains the large number of existing pathotypes. Several lines of evidence indicate that such diversity is, at least in part, due to plant and pathogen co-evolution. A co-evolution model based on the binary classification of 25 races identified in Brazil by inoculation of differential cultivars and random amplified polymorphic DNA (RAPD) data is proposed. In this model, races 8 and 64 that infected bean cultivar Cornell 49-242 (Are gene) and Mexico 222 (Mexico I gene) are considered to be sources of two important evolutionary routes. Inferences about undescribed races from Brazil could be made. |
| Tipo: Info:eu-repo/semantics/other |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000100022 |
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| Guerreiro,João Farias; Ribeiro-dos-Santos,Ândrea Kely Campos; Santos,Eduardo José Melo dos; Vallinoto,Antonio Carlos Rosário; Cayres-Vallinoto,Izaura Maria Vieira; Aguiar,Gilberto Ferreira de Souza; Santos,Sidney Emanuel Batista dos. |
| The Amazon region of Brazil includes communities founded by escaped slaves, some of which still remain relatively isolated. We studied two such Afro-Brazilian communities (Pacoval and Curiau), in the rural area of Alenquer, Pará, and in the metropolitan region of Macapá, Amapá, respectively. Among 12 blood loci, alleles considered as markers of African ancestry, such as HBB*S, HBB*C, TF*D1, HP*2M, ABO*B, RH*D-, and CA2*2 were found at frequencies that are expected for populations with a predominantly African origin. Estimates of interethnic admixture indicated that the degree of the African component in Curiau (74%) is higher than that of Pacoval (44%); an Amerindian contribution was not detected in Curiau. Estimated values of African ancestry fit well... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000200004 |
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| Guimarães,Claudia T.; Honeycutt,Rhonda J.; Sills,Gavin R.; Sobral,Bruno W.S.. |
| Genetic analysis was performed in a population composed of 100 F1 individuals derived from a cross between a cultivated sugarcane (S. officinarum `LA Purple') and its proposed progenitor species (S. robustum `Mol 5829'). Various types (arbitrarily primed-PCR, RFLPs, and AFLPs) of single-dose DNA markers (SDMs) were used to construct genetic linkage maps for both species. The LA Purple map was composed of 341 SDMs, spanning 74 linkage groups and 1,881 cM, while the Mol 5829 map contained 301 SDMs, spanning 65 linkage groups and 1,189 cM. Transmission genetics in these two species showed incomplete polysomy based on the detection of 15% of SDMs linked in repulsion in LA Purple and 13% of these in Mol 5829. Because of this incomplete polysomy, multiple-dose... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000100024 |
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| Meireles,Carla Maria; Czelusniak,John; Ferrari,Stephen F.; Schneider,Maria Paula Cruz; Goodman,Morris. |
| The genus Alouatta (howler monkeys) is the most widely distributed of New World primates, and has been arranged in three species groups: the Central American Alouatta palliata group and the South American Alouatta seniculus and Alouatta caraya groups. While the latter is monotypic, the A. seniculus group encompasses at least three species (A. seniculus, A. belzebul and A. fusca). In the present study, approximately 600 base pairs of the g1-globin pseudogene were sequenced in the four Brazilian species (A. seniculus, A. belzebul, A. fusca and A. caraya). Maximum parsimony and maximum likelihood methods yielded phylogenetic trees with the same arrangement: {A. caraya [A. seniculus (A. fusca, A. belzebul)]}. The most parsimonious tree had bootstrap values... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000300009 |
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| Kim,C.A.; Passos-Bueno,M.R.; Marie,S.K.; Cerqueira,A.; Conti,U.; Marques-Dias,M.J.; Gonzalez,C.H.; Zatz,M.. |
| Spinal muscular atrophy (SMA), the second most common lethal autosomal recessive disorder, has an incidence of 1:10,000 newborns. SMA is divided into acute (Werdnig-Hoffmann disease, type I), intermediate (type II) and juvenile forms (Kugelberg-Welander disease, type III). The gene of all three forms of SMA maps to chromosome 5q 11.2-13.3. Two candidate genes, the survival motor neuron (SMN) gene and the neuronal apoptosis inhibitory protein (NAIP) gene, have been identified; SMN is deleted in most SMA patients. We studied both genes in 87 Brazilian SMA patients (20 type I, 14 type II and 53 type III) from 74 unrelated families, by using PCR and single strand conformation polymorphism (SSCP). Deletions of exons 7 and/or 8 of the SMN gene were found in 69%... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000400005 |
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| Pacheco,Cleso Antônio Patto; Cruz,Cosme Damião; Santos,Manoel Xavier dos. |
| The objective of the present work was to provide a methodology to study the inheritance of adaptability and stability through the breakdown of Eberhart and Russell regression coefficients and regression deviations in effects due to the mean and additive genetic effects (gi's and gj's) as well as dominance effects (sij's) of Griffing´s methodology, when the diallel is conducted in several environments. It was concluded that the adaptability and stability parameters are determined in the same manner as are genetic effects. So an F1 cross inherits half the general combining ability (GCA) mean effect from each parent, while the effects due to specific combining ability (SCA) are subjected to the same considerations relative to sij's, i.e., they are dependent... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000300027 |
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| Costa,Claudio Napolis. |
| Heterogeneity of variance in Brazilian herd environments was studied using first-lactation 305-day mature equivalent (ME) milk and fat records of Holstein cows. Herds were divided into two categories, according to low or high herd-year phenotypic standard deviation for ME milk (HYSD). There were 330 sires with daughter records in both HYSD categories. Components of (co)variance, heritability, and genetic correlations for milk and fat yields were estimated using a sire model from bivariate analyses with a restricted maximum likelihood (REML) derivative-free algorithm. Sire and residual variances for milk yield in low HYSD herds were 79 and 57% of those obtained in high HYSD herd. For fat yield they were 67 and 60%, respectively. Heritabilities for milk and... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000300015 |
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| Miranda Filho,José B.; Vencovsky,Roland. |
| The partial circulant diallel cross mating scheme of Kempthorne and Curnow (Biometrics 17: 229-250, 1961) was adapted for the evaluation of genotypes in crosses at the interpopulation level. Considering a random sample of n lines from base population I, and that each line is crossed with s lines from opposite population II, there will be ns sampled crosses that are evaluated experimentally. The means of the ns sampled crosses and the remaining n(n - s) crosses can be predicted by the reduced model <img src="http:/img/fbpe/gmb/v22n2/0291e1.gif" align="absmiddle"> where Yij is the mean of the cross between line i (i = 1,2,...,n) of population I and line j (j = 1',2',...,n') of population II; µ is the general mean, and gi and gj refer to general... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000200020 |
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| Carrijo,Sônia Mara; Duarte,Francisco A. Moura. |
| Weight data from birth to 18 months of age of Nelore and Chianina, both meat-producing cattle breeds, were analyzed. Data were corrected for significant effects of environment and utilized to estimate genetic parameters through the non-linear von Bertalanffy model. Average values found for growth parameters in Nelore were: mature weight (A), 312.87 kg; integration constant (B), 0.49; maturity rate (k), 0.13; age at inflection point (T(I)), 3.29 months; weight at inflection point (P(I)), 92.70 kg, and maturity interval (1/k), 8.04 months. For the Chianina animals, the values were 751.38 kg, 0.59, 0.10, 6.64 months, 222.63 kg, and 10.98 months, respectively. Nelore animals exhibited higher maturity rate, smaller maturity intervals, reaching mature weights... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000200009 |
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| Maistro,Edson Luis; Foresti,Fausto; Oliveira,Claudio. |
| The absence of longitudinal bands in fish chromosomes has been associated with technical problems in chromosome preparations or the absence of a structural compartmentalization in the fish genome. In the present study, a R-banding pattern was obtained using a replication banding technique by in vivo treatment with 5-bromodeoxyuridine (5-BrdU). G-banding patterns were obtained after trypsin treatment and also after chromosome cleavage by in situ treatment with the restriction endonuclease BamHI. A similar G-banding pattern was also obtained after cleavage with the endonuclease HinfI. Presence of a resolute R- and G-banding patterns shows that Astyanax scabripinnis paranae chromosomes could present an isochore-like structure similar to that found in other... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000200011 |
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| Artoni,Roberto Ferreira; Molina,Wagner Franco; Bertollo,Luis Antonio Carlos; Galetti Junior,Pedro Manoel. |
| The chromosomes of two neotropical freshwater fish species, namely Liposarcus anisitsi (Siluriformes, Loricariidae) and Leporinus elongatus (Characiformes, Anostomidae), were investigated by means of C-banding, Ag-NORs, fluorochrome staining and banding by hot saline solution (HSS) treatment, to reveal patterns of heterochromatin differentiation. The karyotype of L. anisitsi is described for the first time. Staining with the GC-specific fluorescent antibiotic mithramycin (MM) revealed bright signals in some C-banded blocks in both species, suggesting that these MM+ heterochromatin contains GC-rich DNA. Banding by denaturation employing HSS, followed by Giemsa staining, yielded corresponding results documenting the thermal stability of GC-rich DNA part of... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000100009 |
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| Regitano,L.C.A.; Azevedo,J.L.; Vencovsky,R.; Packer,I.U.; Barbosa,P.F.; Rosa,A.J.M.; Silva,N.A.; Etchegaray,M.A.L.; Coutinho,L.L.. |
| This study was developed to evaluate selection effects on gene frequencies in a synthetic beef cattle cross (5/8 Charolais, 3/8 Zebu) named Canchim. A sample of 154 Canchim animals, representing three generation classes, was analyzed for seven molecular markers. Thirty-six Charolais cattle were also studied for comparison. A highly significant variation (P < 0.01), with a linear increase of the allele coding for valine at position 127 of the growth hormone peptide, was observed through generations. This allele was found in the Charolais sample but is not observed in Brazilian Bos indicus breeds. Four alleles were found for a microsatellite in the 5' flanking region of insulin-like growth factor I gene in Canchim. Allele sizes ranged from 231 to 225... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000400011 |
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| Neves,Walter A.; Powell,Joseph F.; Prous,Andre; Ozolins,Erik G.; Blum,Max. |
| Several studies concerning the extra-continental morphological affinities of Paleo-Indian skeletons, carried out independently in South and North America, have indicated that the Americas were first occupied by non-Mongoloids that made their way to the New World through the Bering Strait in ancient times. The first South Americans show a clear resemblance to modern South Pacific and African populations, while the first North Americans seem to be at an unresolved morphological position between modern South Pacific and Europeans. In none of these analyses the first Americans show any resemblance to either northeast Asians or modern native Americans. So far, these studies have included affirmed and putative early skeletons thought to date between 8,000 and... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000400001 |
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| Burim,Regislaine V.; Canalle,Renata; Lopes,João L. Callegari; Takahashi,Catarina S.. |
| Glaucolide B is a sesquiterpene lactone isolated from Vernonia eremophila Mart. (Vernonieae, Asteraceae) and has schistosomicidal, antimicrobial and analgesic activities. This study examined the cytotoxic and clastogenic activities of glaucolide B in human cultured lymphocytes and in bone marrow cells from BALB/c mice. The mitotic index (MI) and chromosomal aberrations were analyzed in both of the above systems, whereas sister chromatid exchanges (SCE) and the proliferation index (PI) were determined only in vitro. In human cultured lymphocytes, glaucolide B concentrations greater than 15 µg/ml of culture medium completely inhibited cell growth. At 4 µg/ml and 8 µg/ml of culture medium, glaucolide B significantly increased the frequency of chromosomal... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000300020 |
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| Gollop,Thomaz Rafael; Salzo,Ivan. |
| Fetal hydantoin syndrome (FHS) is a set of disruptions occasionally present in fetuses exposed in utero to phenytoin or other anticonvulsants. Administration of phenytoin in early pregnancy may impair proper psychomotor performance expected for children's development. Several combined phenotypic markers delineate the syndrome, but the presence of single clinical signs is more common. There is controversy about the etiology of FHS. Associated disruptions may be related to a deficiency in a detoxifying enzyme (epoxide hydrolase), vascular problems, and/or factors not yet known. Genetic causes are believed to influence susceptibility to the drug. This text reports an unusual pattern of malformations detected in an ultrasound scan (gastroschisis, sacral... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000200002 |
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| Domínguez,M.G.; Rivera,H.; Vásquez,A.I.; Ramos,A.L.. |
| Single cell chromosome rearrangements (SCCR) are incidental findings in cell cultures. Nevertheless, some authors have implicated them in habitual abortion. Ninety individuals classified in four groups were prospectively studied: A) individuals with spontaneous abortions, malformed children or molar pregnancies (N = 36); B) azoospermic males (N = 14); C) individuals with one or more children with either de novo or inherited, constitutional, chromosome abnormalities (N = 26), and D) individuals with healthy children and no reproductive failure (control group, N = 14). Lymphocyte chromosome preparations were stained for GTG bands, and 50-100 metaphases were scored per individual. The rearrangements observed were translocations, deletions, duplications,... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000100005 |
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| Ribeiro,Luciana A.; Azevedo,João L.; Aragão,Francisco J.L.; Rech,Elibio L.; Schmidt,Gilberto S.; Coutinho,Luiz L.. |
| Fertilized chicken eggs were bombarded with a biolistic device. Transient expression of the lacZ gene under the control of a human cytomegalovirus (CMV) promoter was assessed after in situ gene transfer using this approach. The influence of different pressures, vacuum levels and particles was tested. Survival rate improved as particle velocity decreased, but resulted in lower levels of expression. The best survival and expression were obtained with gold particles, a helium gas pressure of 600 psi and a vacuum of 600 mmHg. Under these conditions, all bombarded embryos showed <FONT FACE="Symbol">b</FONT>-galactosidase activity, indicating that this was an effective method for transformation of chicken embryos. |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000400010 |
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| Registros recuperados: 6.820 | |
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