Sharbel Maluf

Publications (17) View all

• Source

  Available from: Daniel Prá

  Article: DNA damage in children and adolescents with cardiovascular disease risk factors.

  Mariele Kliemann, Daniel Prá, Luiza L Müller, Liziane Hermes, Jorge A Horta, Miriam B Reckziegel, Miria S Burgos, Sharbel W Maluf, Silvia I R Franke, Juliana da Silva
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  ABSTRACT: The risk of developing cardiovascular disease (CVD) is related to lifestyle (e.g. diet, physical activity and smoking) as well as to genetic factors. This study aimed at evaluating the association between CVD risk factors and DNA damage levels in children and adolescents. Anthropometry, diet and serum CVD risk factors were evaluated by standard procedures. DNA damage levels were accessed by the comet assay (Single cell gel electrophoresis; SCGE) and cytokinesis-blocked micronucleus (CBMN) assays in leukocytes. A total of 34 children and adolescents selected from a population sample were divided into three groups according to their level of CVD risk. Moderate and high CVD risk subjects showed significantly higher body fat and serum CVD risk markers than low risk subjects (P<0.05). High risk subjects also showed a significant increase in DNA damage, which was higher than that provided by low and moderate risk subjects according to SCGE, but not according to the CBMN assay. Vitamin C intake was inversely correlated with DNA damage by SCGE, and micronucleus (MN) was inversely correlated with folate intake. The present results indicate an increase in DNA damage that may be a consequence of oxidative stress in young individuals with risk factors for CVD, indicating that the DNA damage level can aid in evaluating the risk of CVD.
  Anais da Academia Brasileira de Ciências 06/2012; 84(3):833-40. · 1.09 Impact Factor
• Article: The influence of nutrigenetics on the lipid profile: interaction between genes and dietary habits.

  Fabiana M de Andrade, Andréa C Bulhões, Sharbel W Maluf, Jaqueline B Schuch, Francine Voigt, Juliana F Lucatelli, Alessandra C Barros, Mara H Hutz
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  ABSTRACT: Nutrigenetics is a new field with few studies in Latin America. Our aim is to investigate the way in which different genes related to the lipid profile influence the response to specific dietary habits. Eight polymorphisms on seven genes were investigated in a sample (n = 567) from Porto Alegre, RS, Brazil. All the volunteers completed a food diary that was then assessed and classified into nine food groups. A number of nutrigenetic interactions were detected primarily related to the apolipoprotein E (apoE) gene. For example, frequent consumption of foods rich in polyunsaturated fat resulted in the beneficial effect of increasing HDL-C only in individuals who were not carriers of the E*4 allele of the APOE gene, whereas variations in eating habits of E*4 carriers did not affect their HDL-C (P = 0.018). Our data demonstrate for the first time nutrigenetic interactions in a Brazilian population.
  Biochemical Genetics 04/2010; 48(3-4):342-55. · 0.86 Impact Factor
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  Available from: Sharbel Maluf

  Article: Genomic instability in patients with type 2 diabetes mellitus on hemodialysis.

  Roberta Passos Palazzo, Pamela Brambilla Bagatini, Patrícia Brandt Schefer, Fabiana Michelsen de Andrade, Sharbel Weidner Maluf
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  ABSTRACT: A previous study by our research group evaluated the levels of DNA damage using the comet assay in hemodialysis patients with type 2 diabetes mellitus. The same blood samples were also evaluated using the cytochalasin B micronucleus assay. A comparison of the results of the two assays is presented here. Whole blood samples were collected from 22 type 2 diabetes mellitus patients on hemodialysis and from 22 control subjects. Samples were collected from patients early in the morning on Mondays, before the first weekly hemodialysis session. The cytokinesis-block micronucleus assay (CBMN) was used to evaluate genomic instability. The frequencies of micronuclei and nuclear buds were higher in patients than in controls (p-value = 0.001 and p-value < 0.001, respectively). There was a correlation between the frequency of micronuclei and DNA damage with the results of the comet assay (p-value < 0.001). The difference in the frequency of micronuclei and nuclear buds between patients and controls was more pronounced in the group with higher median comet values than in the group with lower comet values. Our results suggest that the increased rates of DNA damage as measured by the comet assay and influenced by the weekly routine therapy of these patients has a mutagenic effect, thereby increasing the risk of cancer in this group.
  Revista brasileira de hematologia e hemoterapia. 01/2012; 34(1):31-5.
• Source

  Available from: Daniel Prá

  Article: Iron intake, red cell indicators of iron status, and DNA damage in young subjects.

  Daniel Prá, Angelica Bortoluzzi, Luiza Louzada Müller, Liziane Hermes, Jorge André Horta, Sharbel Weidner Maluf, João Antonio Pêgas Henriques, Michael Fenech, Silvia Isabel Rech Franke
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  ABSTRACT: This study evaluated the association between primary DNA damage and chromosomal damage with iron intake and red blood cell parameters of iron status in a sample of healthy children and adolescents from a low-socioeconomic community. The level of primary DNA damage was assessed using an alkaline comet assay and the level of chromosomal damage was assessed using the cytokinesis-block micronucleus assay. A automated complete blood count was used to evaluate red blood cell status. The intake of iron was measured using a food-recall questionnaire. According to hemoglobin levels, only 1 of the 30 subjects evaluated was anemic. Nevertheless, 43% of the sampled subjects showed decreased mean corpuscular volume in addition to an increased amount of primary DNA damage (P < 0.05). Mean corpuscular volume was negatively correlated with primary DNA damage (r = -0.429, P = 0.020) but not with chromosomal damage. The association between iron and primary DNA damage showed a U-shaped curve, indicating that an intake of approximately 15 mg of iron per day (up to two-fold of the dietary recommended intake) could minimize primary DNA damage in this age group. The frequency of micronuclei and nucleoplasmic bridges, indicators of chromosomal breakage/loss and chromosomal end-fusions, respectively, showed a negative correlation with iron intake. These results indicate that an intake of iron >15 mg/d could increase genomic stability in binucleated lymphocytes of the same group. An intake of iron ≥ 15 mg/d can decrease DNA damage in young subjects.
  Nutrition 03/2011; 27(3):293-7. · 3.03 Impact Factor
• Article: Are MPS II heterozygotes actually asymptomatic? A study based on clinical and biochemical data, X-inactivation analysis and imaging evaluations.

  Louise Lapagesse de Camargo Pinto, Sharbel Weidner Maluf, Sandra Leistner-Segal, Camila Zimmer da Silva, Ana Brusius-Facchin, Maira Graef Burin, Silvia Brustolin, Juan Llerena, Lucia Moraes, Leonardo Vedolin, Alice Schuch, Roberto Giugliani, Ida Vanessa Doederlein Schwartz
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  ABSTRACT: For some X-linked disorders the expressivity and penetrance in females are almost similar to those ones found in males. For mucopolysaccharidosis type II (MPS II), there are no studies in the literature trying to identify subtle signs and symptoms of this disease in heterozygotes. The objective of this study was to compare heterozygotes and non-heterozygotes for MPS II, in order to test the hypothesis that heterozygotes may present subtle manifestations of the disease. In this observational and transversal study we collected data on 40 Brazilian women with a positive familial history for MPS II that included clinical and physical exam, karyotype, pattern of X-inactivation, iduronate-2-sulfatase (IDS) activity in leukocytes and plasma, urinary glycosaminoglycans levels, computerized tomography scans (CT) of abdomen and spine, and brain magnetic resonance imaging. The Results showed the following: According to DNA analysis, 22 women were classified as heterozygote and 18 as non-heterozygotes. We did not find any abnormality on physical examination, karyotype, or spine CT. Also the pattern of X-inactivation was not different between the groups. Applying the Bonferroni's correction, both groups were found to differ only in relation to IDS activity in plasma and in leukocyte, which were lower in heterozygotes. In our investigation we did not find any evidence of subtle clinical manifestations of MPS II in heterozygotes. Our findings suggest there is no relation between the absence of clinical signs in these women and the occurrence of a favorable skewing pattern of X-inactivation.
  American Journal of Medical Genetics Part A 01/2011; 155A(1):50-7. · 2.39 Impact Factor