SANDRA MARA FERREIRA VILLARES
Projetos de Pesquisa
Unidades Organizacionais
LIM/18 - Laboratório de Carboidratos e Radioimunoensaios, Hospital das Clínicas, Faculdade de Medicina
14 resultados
Resultados de Busca
Agora exibindo 1 - 10 de 14
- Lack of mutations in the leptin receptor gene in severely obese children(2012) DIAS, Natasha Favoretto; FERNANDES, Ariana Ester; MELO, Maria Edna de; REINHARDT, Heidi Lui; CERCATO, Cintia; VILLARES, Sandra Mara Ferreira; HALPERN, Alfredo; MANCINI, Marcio C.Objective: To analyze the LEPR gene in obese children and to investigate the associations between molecular findings and anthropometric and metabolic features. Subjects and methods: Thirty-two patients were evaluated regarding anthropometric characteristics, blood pressure, heart rate, serum glucose, insulin, leptin levels, and lipid profile. The molecular study consisted of the amplification and automatic sequencing of the coding region of LEPR in order to investigate new mutations. Results: We identified a high prevalence of metabolic disorders: impaired fasting glucose in 12.5% of the patients, elevated HOMA-IR in 85.7%, low HDL-cholesterol levels in 46.9%, high triglyceride levels in 40.6%, and hypertension in 58.6% of the patients. The molecular study identified 6 already described allelic variants: rs1137100 (exon-2), rs1137101 (exon-4), rs1805134 (exon-7), rs8179183 (exon-12), rs1805096 (exon-18), and the deletion/insertion of the pentanucleotide CTTTA at 3'untranslated region. Conclusions: The frequency of alleles observed in this cohort is similar to that described in the literature, and was not correlated with any clinical feature. The molecular findings in the analysis of the LEPR did not seem to be implicated in the etiology of obesity in these patients.
- Expression of Clock Genes in Human Subcutaneous and Visceral Adipose Tissues(2012) ZANQUETTA, Melissa Moreira; CORREA-GIANNELLA, Maria Lucia; GIANNELLA-NETO, Daniel; ALONSO, Paulino Alberto; GUIMARAES, Ligia Maria Martins Vaz; MEYER, Alberto; VILLARES, Sandra Mara FerreiraDisrupted circadian rhythms are associated with obesity and metabolic alterations, but little is known about the participation of peripheral circadian clock machinery in these processes. The aim of the present study was to analyze RNA expression of clock genes in subcutaneous (SAT) and visceral (VAT) adipose tissues of male and female subjects in AM (morning) and PM (afternoon) periods, and its interactions with body mass index (BMI). Ninety-one subjects (41 +/- 11 yrs of age) presenting a wide range of BMI (21.4 to 48.6 kg/m(2)) were included. SAT and VAT biopsies were obtained from patients undergoing abdominal surgeries. Clock genes expressions were evaluated by qRT-PCR. The only clock gene that showed higher expression (p < .0001) in SAT in comparison to VAT was PER1 of female (372%) and male (326%) subjects. Different patterns of expression between the AM and PM periods were observed, in particular REV-ERBa, which was reduced (p < .05) at the PM period in SAT and VAT of both women and men (women: similar to 53% lower; men: similar to 78% lower), whereas CLOCK expression was not altered. Relationships between clock genes were different in SAT vs. VAT. BMI was negatively correlated with SATPER1 (r = -.549; p = .001) and SATPER2 (r = -.613; p = .0001) and positively with VATCLOCK (r = .541; p = .001) and VATBMAL1 (r = .468; p = .007) only in women. These data suggest that the circadian clock machinery of adipose tissue depots differs between female and male subjects, with a sex-specific effect observed for some genes. BMI correlated with clock genes, but at this moment it is not possible to establish the cause-effect relationship. (Author correspondence: mzanquetta@gmail.com)
- Noonan syndrome patients beyond the obvious phenotype: A potential unfavorable metabolic profile(2021) NORONHA, Renata M.; VILLARES, Sandra M. F.; TORRES, Natalia; QUEDAS, Elisangela P. S.; HOMMA, Thais Kataoka; ALBUQUERQUE, Edoarda V. A.; MORAES, Michelle B.; FUNARI, Mariana F. A.; BERTOLA, Debora R.; JORGE, Alexander A. L.; MALAQUIAS, Alexsandra C.Noonan syndrome (NS) and NS related disorders (NRD) are frequent monogenic diseases. Pathogenic variants in PTPN11 are observed in approximately 50% of these NS patients. Several pleiotropic phenotypes have previously been described in this condition. This study aimed at characterizing glucose and lipid profiles in patients with NS/NRD. We assessed fasting blood glucose, insulin, cholesterol (total and fractions), and triglyceride (TG) levels in 112 prepubertal children and 73 adults. Additionally, an oral glucose tolerance test (OGTT) was performed in 40 children and 54 adults. Data were analyzed between age groups according to the presence (+) or absence (-) of PTPN11 mutation. Prepubertal patients with NS/NRD were also compared with a control group. Despite the lean phenotype of children with NS/NRD, they presented an increased frequency of low HDL-cholesterol (63% in PTPN11+, 59% in PTPN11- and 16% in control, p < .001) and high TG levels (29% in PTPN11+, 18% in PTPN11- and 2.3% in control). PTPN11+ patients had a higher median HOMA-IR (1.0, ranged from 0.3 to 3.2) in comparison with PTPN11- (0.6; 0.2 to 4.4) and controls (0.6; 0.4 to 1.4, p = .027). Impaired glucose tolerance was observed in 19% (10:54) of lean adults with NS/NRD assessed by OGTT. Moreover, women with PTPN11 mutations had lower HDL-cholesterol levels than those without. Our results suggest that children and young adult patients with NS/NRD have an unfavorable metabolic profile characterized by low HDL, a tendency of elevated TGs, and glucose metabolism impairment despite a lean phenotype.
- Allelic variations in the vitamin D receptor gene, insulin secretion and parents' heights are independently associated with height in obese children and adolescents(2012) FERRAREZI, Daniela A. F.; BELLILI-MUNOZ, Naima; NICOLAU, Christiane; CHEURFA, Nadir; GUAZZELLI, Isabel C.; FRAZZATTO, Eliana; VELHO, Gilberto; VILLARES, Sandra M.Polymorphisms in the VDR gene were reported to be associated with variations in intrauterine and postnatal growth and with adult height, but also with other traits that are strongly correlated such as the BMI, insulin sensitivity, insulin secretion and hyperglycemia. Here, we assessed the impact of VDR polymorphisms on body height and its interactions with obesity- and glucose tolerance-related traits in obese children and adolescents. We studied 173 prepubertal (Tanner's stage 1) and 146 pubertal (Tanner's stages 2-5) obese children who were referred for a weight-loss program. Three single nucleotide polymorphisms were genotyped: rs1544410 (BsmI), rs7975232 (ApaI) and rs731236 (TaqI). BsmI and TaqI genotypes were significantly associated with height in pubertal children, but the associations did not reach statistical significance in prepubertal children. In stepwise regression analyses, the lean body mass, insulin secretion, BsmI or TaqI genotypes and the father's and the mother's height were independently and positively associated with height in pubertal children. These covariables accounted for 46% of the trait variance. The height of homozygous carriers of the minor allele of BsmI was 0.65 z-scores (4 cm) higher than the height of homozygous carriers of the major allele (P=.0006). Haplotype analyses confirmed the associations of the minor alleles of BsmI and TaqI with increased height. In conclusion, VDR genotypes were significantly associated with height in pubertal obese children. The associations were independent from the effects of confounding traits, such as the body fat mass, insulin secretion, insulin sensitivity and glucose tolerance.
- Novel inactivating mutations in the GH secretagogue receptor gene in patients with constitutional delay of growth and puberty(2011) PUGLIESE-PIRES, Patricia N.; FORTIN, Jean-Philippe; ARTHUR, Thais; LATRONICO, Ana Claudia; MENDONCA, Berenice B.; VILLARES, Sandra Mara F.; PARNHOLD, Ivo J.; KOPIN, Alan S.; JORGE, Alexander A. L.Background: A limited number of mutations in the GH secretagogue receptor gene (GHSR) have been described in patients with short stature. Objective: To analyze GHSR in idiopathic short stature (ISS) children including a subgroup of constitutional delay of growth and puberty (CDGP) patients. Subjects and methods: The GHSR coding region was directly sequenced in 96 independent patients with ISS, 31 of them with CDGP, in 150 adults, and in 197 children with normal stature. The pharmacological consequences of GHSR non-synonymous variations were established using in vitro cell-based assays. Results: Five different heterozygous point variations in GHSR were identified (c.-6 G>C, c.251G>T (p.Ser84Ile), c.505G>A (p.Ala169Thr), c.545 T>C (p.Val182Ala), and c.1072G>A (p.Ala358Thr)), all in patients with CDGP. Neither these allelic variants nor any other mutations were found in 694 alleles from controls. Functional studies revealed that two of these variations (p.Ser84Ile and p. Val182Ala) result in a decrease in basal activity that was in part explained by a reduction in cell surface expression. The p.Ser84Ile mutation was also associated with a defect in ghrelin potency. These mutations were identified in two female patients with CDGP (at the age of 13 years, their height SDS were -2.4 and -2.3). Both patients had normal progression of puberty and reached normal adult height (height SDS of -0.7 and -1.4) without treatment. Conclusion: This is the first report of GHSR mutations in patients with CDGP. Our data raise the intriguing possibility that abnormalities in ghrelin receptor function may influence the phenotype of individuals with CDGP.
bookPart Ritmos circadianos e obesidade(2015) ZANQUETTA, Melissa Moreira; MONTEIRO, Maria Beatriz; CORRêA-GIANNELLA, Maria Lúcia; VILLARES, Sandra M. FerreiraconferenceObject Children with Noonan and Noonan-Like Syndromes Had a Lipid Profile Resembling Metabolic Syndrome and Type 2 Diabetes(2015) MALAQUIAS, A.; HOMMA, T.; MORAES, M.; FUNARI, M.; PEREIRA, A.; VILLARES, S.; BERTOLA, D.; JORGE, A.- Angiotensin converting enzyme insertion/deletion polymorphism is associated with increased adiposity and blood pressure in obese children and adolescents(2013) LEMES, Vinicius A. F.; NEVES, Ana Luisa; GUAZZELLI, Isabel C.; FRAZZATTO, Eliana; NICOLAU, Christiane; CORREA-GIANNELLA, Maria Lucia; VELHO, Gilberto; VILLARES, Sandra M. F.Background: The insertion/deletion polymorphism in the gene encoding the angiotensin-converting enzyme (ACE I/D) was associated with arterial hypertension and obesity in adults, but the data in children are scarce and yielded contrasting results. We assessed the impact of the ACE I/D on blood pressure and obesity related traits in a Brazilian cohort of obese children and adolescents. Methods and results: ACE I/D was genotyped in 320 obese children and adolescents (64% of girls) aged 7-16 years, referred for a weight-loss program. We observed an association of the D-allele with blood pressure and with pre-hypertension/hypertension in boys (odds ratio 2.44,95% C.I. 1.34-4.68, p = 0.005 for a codominant model). The D-allele, insulin resistance and body fat mass had independent and additive effects and explained 14% of the variance of pre-hypertension/hypertension. The BMI, waist circumference, and body fat mass were significantly higher in DD/ID boys than in II boys (p < 0.005). Allelic associations with obesity related traits were independent of the association with blood pressure. No genotype associations were observed in girls. Conclusions: The D-allele of the ACE I/D polymorphism was associated with arterial hypertension and with obesity related traits in boys, but not in girls, in a cohort of obese children and adolescents. These associations were independent of each other, as well as of the effects of other confounding traits such as insulin secretion, insulin sensitivity and glucose tolerance. Our results are in agreement with experimental evidences suggesting that the renin-angiotensin system plays a role in the regulation of visceral adipose tissue accumulation.
conferenceObject Predictors of Successful Weight-Loss During a Lifestyle and Nutritional Education program in Brazilian Obese Children and Adolescents(2014) VILLARES, Sandra Mara F.; ARTHUR, Thais; GUAZZELLI, Isabel C.; FRAZZATTO, Eliana; NICOLAU, Christiane; VELHO, Gilberto; CORREA-GIANNELLA, Maria Lucia- Obesity and Familial Predisposition Are Significant Determining Factors of an Adverse Metabolic Profile in Young Patients with Congenital Adrenal Hyperplasia(2013) MOREIRA, Ricardo P. P.; VILLARES, Sandra M.; MADUREIRA, Guiomar; MENDONCA, Berenice B.; BACHEGA, Tania A. S. S.Background/Aims: Glucocorticoid (GC) therapy is known to predispose to an adverse metabolic profile. Therefore, we investigated the prevalence of obesity and metabolic syndrome (MetS) in young patients with congenital adrenal hyperplasia (CAH) and to correlate this prevalence with GC treatment and family history. Methods: The study population consisted of 33 young CAH patients who received cortisone acetate during their growth periods; those who were salt wasters also received fludrocortisone. Obesity was defined by a body mass index (BMI) >95th percentile and MetS by the National Cholesterol Education Program Third Adult Treatment Panel modified criteria. Each patient's familial history of MetS components was assessed. The impact of GC therapy on the metabolic profile was analyzed by comparing CAH patients with BMI z-score-matched controls. Results: MetS and obesity were observed in 12.1 and 30.3% of the CAH patients, respectively, both of which were higher than in the reference population. A positive family history of MetS was found to be more prevalent in the obese patients compared with the nonobese CAH patients, and similar findings were observed for the controls. The metabolic profile did not differ between the CAH patients and matched subjects. Conclusion: CAH patients presented a higher prevalence of obesity and MetS, which were not correlated with the GC treatment. This study suggests that obesity and familial predisposition are significant determining factors for an adverse metabolic profile in CAH patients.