A D da Cruz

Publications (12)24.31 Total impact

• Article: Allelic frequencies and statistical data obtained from 15 STR loci in a population of the Goiás State.

  T C Vieira, D M Silva, M A D Gigonzac, V L Ferreira, M W Gonçalves, A D da Cruz
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  ABSTRACT: Due to the miscegenation of the Brazilian population, the central region of Brazil was colonized by internal migration of individuals from different origins, who contributed to the genetic diversity existing in this population. The purpose of this study was to estimate population parameters based on the allele frequencies for 15 polymorphic autosomal short-tandem repeat (STR) loci present in the population of the State of Goiás in the central region of Brazil, and to compare the results with those of others from different Brazilian populations. DNA was obtained from a sample of 986 unrelated individuals by a commercial reagent kit and was quantified by spectrometry for later amplification in the thermocycler. These loci, commonly used in forensics and paternity testing, reflected Hardy-Weinberg equilibrium in this population. The D18S51 and Penta E loci had the highest number of alleles, while the observed heterozygosity reached the highest rates in FGA (0.920), D7S820 (0.870), and vWA (0.867) markers. Genetic diversity reached the highest levels in Penta E (0.906), Penta D (0.873), and D18S51 (0.860) markers, and the investigated forensic parameters showed high average values, with 93% power of discrimination, polymorphism information content of 78%, gene diversity of 79%, and observed heterozygosity of 79%. Similar to the other populations of Brazil, the population of the Midwest is derived from the admixture of 3 main parental groups: Amerindian, European, particularly Portuguese, and Africans from sub-Saharan Africa. In this context, the overall distribution of allele frequencies in the STR markers of various Brazilian populations is quite similar to the data obtained in this study.
  Genetics and molecular research: GMR 01/2013; 12(1):23-7. · 1.18 Impact Factor
• Source

  Available from: Alessandro Morais

  Dataset: Contrasting Patterns of DNA Damage by the Comet Assay in Four Species of the Hylidae Family (Amphibia-Anura)

  M W Gonçalves, W F Carvalho, A D Da Cruz, R R S Vieira, A R De Morais, P G Gambale, V G Batista, R P Bastos, D M Silva
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  ABSTRACT: Amphibians are components of many ecological communities and they can be used as indicators of environmental quality. Thus, in this study we evaluated the genome sensitivity of four species of anuran amphibians of the Hylidae family in a cattle raising area (Bela Vista de Goiás) and in a nickel area (Barro Alto) both at Goiás state, Central Brazil. The species analyzed are: Dendropsophus minutus, Hypsiboas albopunctatus, Hypsiboas paranaiba and Scinax fuscomarginatus. The comet assay was used as a biomarker to estimate DNA damage in these four Hylidae species. The genomic analyses were realized using the software "Comet Score" v1.5. An analysis of variances (ANOVA) and t-test were carried out to verify the genomic damage among and between all the four species analyzed. In the three comet assay parameters used, the species sampled from the nickel areas showed the largest stretches of DNA damage when compared to the same species sampled in the cattle raising area. So, we can suggest that all evaluated species may be used for eco-genotoxicity of aquatic environments.
• Article: Cattle fetal sex determination by polymerase chain reaction using DNA isolated from maternal plasma.

  A S da Cruz, D C Silva, E O A Costa, P De M-Jr, C C da Silva, D M Silva, A D da Cruz
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  ABSTRACT: The objective of this study was to evaluate the use of polymerase chain reaction analysis (PCR) of fetal cells/DNA in the maternal plasma of pregnant cows to determine the sex of the fetus. Plasma was harvested from 35 cows of mixed genotype at different stages of pregnancy ranging from 5 to 35 weeks. A male calf and a heifer calf provided the control samples. Fetal sex was determined by amplification of Y-specific sequences. For the 35 cows, the fetal sex predicted by this technique was in accordance with the sex of the calf at birth in 88.6% of cases. The agreement between predicted and observed fetal sex was less for cows with a gestational length of 35-48 days (63.6%). Regression analysis showed that there was a strong relationship between the probability of correctly predicting fetal sex and the stage of gestation. It was estimated that the test performed at 43.8 days post fertilization would have 95% accuracy, increasing to 99% accuracy for testing at 48.4 days and 99.9% accuracy for tests at 55.0 days or later. It was concluded that PCR analysis of fetal cells in maternal plasma can be used to predict successfully the sex of the fetus in cattle.
  Animal reproduction science 02/2012; 131(1-2):49-53. · 1.56 Impact Factor
• Article: Cytogenetic damage in the buccal epithelium of Brazilian aviators occupationally exposed to agrochemicals.

  L B Minasi, E O A Costa, D M Silva, C O A Melo, J G de Almeida, T C Vieira, R L Silva Júnior, C L Ribeiro, C C da Silva, A D da Cruz
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  ABSTRACT: The frequency of micronuclei in both buccal cells and peripheral blood lymphocytes is extensively used as a biomarker of chromosomal damage and genome stability in human populations. We examined whether prolonged exposure to complex mixtures of pesticides leads to an increase in cytogenetic damage. The exposed group comprised 50 agricultural aviators, mainly from Central and Southeast regions of Brazil, who had inhaled agrochemicals for more than 10 years without personal protection equipment; the control group consisted of 17 men from the same regions, without indication of exposure to pesticides, There were three times higher frequencies of micronuclei (P < 0.05) and 2.5 times higher frequencies of binucleated cells in the aviators when compared to controls. However, cytotoxic alterations such as broken eggs and karyorrhexis did not present statistically significant differences between the exposed and control groups. Therefore, diverse agrochemicals used to combat pests in agriculture possess genotoxic effects in the oral mucosa of the agricultural pilots, as showed in this study.
  Genetics and molecular research: GMR 12/2011; 10(4):3924-9. · 1.18 Impact Factor
• Source

  Available from: geneticsmr.com

  Article: Involvement of CYP1A1, GST, 72TP53 polymorphisms in the pathogenesis of thyroid nodules.

  A A S Reis, D M Silva, M P Curado, A D da Cruz
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  ABSTRACT: Specific genotypes appear to be related to the development of thyroid disease. We examined whether polymorphisms of the genes CYP1A1, GSTM1, GSTT1, and TP53 at codon 72 are associated with increased risk for thyroid nodules. Blood samples were obtained from 122 thyroid patients with nodules and from 134 healthy control individuals from Goiânia city, GO, Brazil. We found no significant association of CYP1A1m1 and CYP1A1m2 genotypes with thyroid diseases (P > 0.05). The null genotypes of GSTM1 and GSTT1 genes were predominant in patients with nodules, indicating that individuals that possess these genotypes have a predisposition for thyroid disease. The genotype p53Arg Arg was associated with a low risk for thyroid cancer (OR = 0.15; P < 0.0001), indicating that the arginine allele in homozygosis could have a protective effect against carcinogenesis. On the other hand, the p53ArgPro genotype was significantly associated with malignant neoplastic nodules (OR = 3.65; P = 0.001). Interindividual variation in susceptibility to thyroid diseases could provide new perspectives for early diagnosis, prognosis and treatment, indicating which patients with thyroid nodules will benefit from treatment, depending on specific polymorphic profiles.
  Genetics and molecular research: GMR 01/2010; 9(4):2222-9. · 1.18 Impact Factor
• Source

  Available from: Jalsi Tacon Arruda

  Article: Association between male infertility and androgen receptor mutations in Brazilian patients.

  C O A Melo, A R Danin, D M Silva, J A Tacon, K K V O Moura, E O A Costa, A D da Cruz
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  ABSTRACT: The androgen receptor is encoded by a single-copy gene located in the long arm of the X chromosome (Xq11-12); it consists of eight exons and encodes an intracellular transcription factor that belongs to the steroid/nuclear receptor superfamily. Disturbances in the function of the androgen receptor can lead to several forms of male pseudohermaphroditism, such as androgen insensitivity syndrome, which can lead to infertility. Infertility affects around 20% of couples, and in half of the cases it is a male problem. Seventy male patients with idiopathic infertility were selected; data were obtained on age, drinking and smoking habits, occupation, and family history. The mean age of the patients was 37 years old (standard deviation = 12.3); 44% were azoospermic, 33% were oligozoospermic and 24% did not have alterations in the spermogram. Our objective was to evaluate a possible association between male infertility and mutations in the androgen receptor gene based on the presence or absence of exons 1 and 4 of this gene. These two exons were tested by PCR, and their products were separated on 1.5% agarose gels. We found that azoospermic patients had higher mutation rates on exons 1 and 4 of the androgen receptor gene, when compared to other alterations that also lead to infertility, such as oligozoospermia and teratozoospermia. So, we conclude that patients who do not produce sperm have a higher number of mutations in the androgen receptor gene when compared to those who only have impaired sperm production. Based on molecular analysis, we found that there was no correlation between alterations in the spermogram and mutations on exons 1 and 4 of the androgen receptor gene and no association between alterations in the spermogram and alcohol drinking or smoking.
  Genetics and molecular research: GMR 01/2010; 9(1):128-33. · 1.18 Impact Factor
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  Available from: Jalsi Tacon Arruda

  Article: Homologous recombination between HERVs causes duplications in the AZFa region of men accidentally exposed to cesium-137 in Goiânia.

  J T Arruda, D M Silva, C C Silva, K K V O Moura, A D da Cruz
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  ABSTRACT: In September 1987, in Goiânia, Brazil, one of the most serious radiological accidents occurred at a radiation therapy unit involving a source of cesium-137. The current study examined the occurrence of possible germline mutations at the AZF region of the exposed men and in their male offspring. Genomic DNA samples of 16 individuals were analyzed for microdeletions. All exposed individuals amplified sequence tagged sites; however, sY84 and sY86 showed a duplication in 75% (12/16) of the exposed group. Exposed families designated as B and E showed a duplication of sY84 and sY86, both in the fathers and their sons. Fathers of families A, C, D, and F did not show a duplication in the AZF region, but their sons did. The children in A and D had duplications of sY84 and sY86, while children in families C and F had a duplication exclusively of sY84. Family G showed a duplication of sY84 in all three generations from grandfather to grandson. Two human endogenous retroviral sequences (HERV) exist in the AZFa region, and non-allelic recombination between these sequences could cause chromosomal rearrangements, such as deletions or duplications, and a mutational mechanism intrinsic to non-allelic recombination could be increased by individual exposure to ionizing radiations from cesium-137. Consequently, the hotspots inside HERV mediated recombination in AZFa, and the duplication diversity was compatible with male fertility, since to date, none of the exposed individuals have demonstrated fertility disorders.
  Genetics and molecular research: GMR 02/2008; 7(4):1063-9. · 1.18 Impact Factor
• Source

  Available from: uvic.ca

  Article: Radiation risk estimation in human populations: lessons from the radiological accident in Brazil.

  A D da Cruz, J P Volpe, V Saddi, J Curry, M P Curadoc, B W Glickman
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  ABSTRACT: The development of radiological and nuclear technologies and the deployment of nuclear weapons have made ionizing radiation one of the most studied human mutagens. Exposure to ionizing radiation produces DNA damage which can result in mutation and cancer, making the risk associated with human exposure a critical issue. In this paper we estimate the risk associated with radiation exposure for individuals exposed to 137Cs during the 1987 Goiânia radiological accident. Using combined regression slopes from both the in vivo hprt mutant frequency and micronucleus frequency data we estimated a doubling dose of 173 (+/-47) cGy for these two endpoints. This is in close agreement with the published estimates for low dose rate and chronic exposure to low-LET radiation. We obtained risk estimates of about 24-fold increase in dominant disorders in the post-exposure generation of the directly exposed population. No detectable increase was found in the population at large. The risk of carcinogenesis in the directly exposed population was found to be increased by a factor in the range of 1.4 to 1.5. The small sample size in this study requires a large element of caution with respect to risk estimates interpretation. Moreover, the doubling dose estimates prepared here are derived from lymphocytes. This somatic data may require additional considerations for both cancer and certainly germ-line events. Nevertheless, the risk of carcinogenesis and genetic harm for this population are good indicators of the potential genetic damage imposed by ionizing radiation to the Goiânia population.
  Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis 03/1997; 373(2):207-14. · 2.85 Impact Factor
• Article: Molecular analysis of T-lymphocyte HPRT- mutations in individuals exposed to ionizing radiation in Goiânia, Brazil.

  A Skandalis, A D da Cruz, J Curry, A Nohturfft, M P Curado, B W Glickman
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  ABSTRACT: We have characterized 54 HPRT- point mutations in T-lymphocytes from 17 individuals exposed to ionizing radiation of 137Cs in Goiania, Brazil and compared this spectrum to that of 30 HPRT- mutants from 9 unexposed Brazilian controls. The average internal exposure of the exposed group was 205 mCi, and the average external exposure was 1.7 Gy. The average HPRT- mutant frequency for the exposed group was 13.3 x 10(-5), approximately a 10-fold increase over the mutant frequency of the unexposed controls, which was 1.56 x 10(-5). The types of point mutations characterized included base substitutions, small deletions, frameshifts, insertions, complex mutations, and losses of exon sequences from the mRNA. The relative frequency of the different mutation types was similar in the two studied groups. However, in our study the distribution of events within the hprt coding sequence seemed to cluster at the same regions of the gene. These observations imply that the hprt gene does not present a homogeneous target to radiation mutagenesis, and perhaps this class of information may be used to detect radiation exposure in human populations.
  Environmental and Molecular Mutagenesis 02/1997; 29(2):107-16. · 3.71 Impact Factor
• Article: Nature of mutation in the human hprt gene following in vivo exposure to ionizing radiation of cesium-137.

  A D da Cruz, B W Glickman
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  ABSTRACT: The current study comprises the analysis of mutations in 10 individuals accidentally exposed to cesium-137 during the 1987 radiological accident in Goiânia, Brazil. Their exposures were among the highest experienced, ranging from 1 to 7 Gy. Peripheral T-lymphocyte samples were obtained 3.3 years after the original exposure and mutation was studied at the hprt locus using the 6-thioguanine-resistance selection assay. The mutational spectrum for the exposed population is comprised of 90 independent mutants. Based on T-cell receptor analysis, only 5% (5/95) were clonally related. Mutants were initially studied using RT-PCR and directly sequenced using an automated laser fluorescent DNA sequencer. Mutants that repeatedly failed to produce cDNAs were studied using a multiplex PCR assay with genomic DNA. Missense mutations were the most frequent event recovered, comprising 40% (23/57) of the spectral sample. An excess of events involving A:T base pairs was observed, exhibiting a significant difference (chi 2 = 12.7, P = 0.0004) when compared to the spontaneous spectrum. This finding may reflect the effect of ionizing radiation-induced damage, suggesting a potential similarity to radiation effects in prokaryotes. At the genomic level, 36.7% (33/90) of the mutants exhibited gross structural alterations, as detected by multiplex PCR. Deletion events were over-represented in our spectral sample, displaying a twofold increase when compared to the frequency observed in the spontaneous mutation database.
  Environmental and Molecular Mutagenesis 02/1997; 30(4):385-95. · 3.71 Impact Factor
• Article: Monitoring hprt mutant frequency over time in T-lymphocytes of people accidentally exposed to high doses of ionizing radiation.

  A D da Cruz, J Curry, M P Curado, B W Glickman
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  ABSTRACT: Modern technologies have provided the opportunity to monitor mutations in people in vivo. The subjects of this study were accidentally exposed to 137Cesium in a radiological accident that occurred in September 1987 in Goiânia, Brazil, during which more than 150 people received doses greater than 0.1 Gy and as high as 7 Gy. The objective of this study was to determine how long the hprt mutant T-cells in the peripheral blood contribute to mutant frequency by examining the time-course of the T-lymphocyte response to ionizing radiation. This report describes the results obtained over a period of 2.3 to 4.5 years subsequent to the accident, from 11 subjects with doses ranging from 1 to 7 Gy, and from nine control subjects selected from the same population. The mean In MF (+/- SE) of the control group was 2.5 (+/- 0.2) + In10(-6). The exposed group had a significantly increased mutant frequency; the mean In MF (+/- SE) were 3.3 (+/- 0.3) + In10(-6), 2.8 (+/- 0.2) + In10(-6), and 2.3 (+/- 0.2) + In10(-6), in the years 1990-1992 respectively. Based on the decline of mutant frequency and using Buckton's models [Buckton et al. (1967): Nature 214:470-473], we demonstrated that mutant T-cells have a short-term memory with a half-life of 2.1 years. This relatively short half-life limits the effective use of the hprt assay as the method of choice to monitor past exposure. The data also demonstrate a positive correlation with age, and an inverse correlation with plating efficiency.
  Environmental and Molecular Mutagenesis 02/1996; 27(3):165-75. · 3.71 Impact Factor
• Article: Human micronucleus counts are correlated with age, smoking, and cesium-137 dose in the Goiânia (Brazil) radiological accident.

  A D da Cruz, A G McArthur, C C Silva, M P Curado, B W Glickman
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  ABSTRACT: A random sample of 276 people representing control, direct exposure, and probable indirect exposure in the Goiânia, Brazil radiological accident was examined using micronuclei as indicators of cytogenetic damage. The Goiânia subjects were analyzed for interactions of age, lifestyle, and ionizing radiation dose. Increases in micronucleus frequencies were most strongly correlated with the dose of ionizing radiation, but age, alcohol consumption, and smoking habits also affected micronucleus frequencies. Despite these additional influences, micronucleus frequencies can be useful as biological dosimeters.
  Mutation Research/Fundamental and Molecular Mechanisms of Mutagenesis 09/1994; 313(1):57-68. · 2.85 Impact Factor