757 research outputs found
Barriers to early identification of autism in Brazil
Objective: Parents of children with autism spectrum disorders (ASD) seem to perceive that their child's development is not following the normal pattern as early as the first year of life. However, ASD children may not receive a diagnosis until they are of preschool age, especially in low- and middle-income countries. The objective of this study was to evaluate the pathway between initial parental concerns about atypical child development and ASD diagnosis in Brazil. Methods: Nineteen mothers whose children had been diagnosed with ASD participated and were interviewed. The ASD group consisted of two girls and 17 boys, with a mean age of 93.0 months (SD 48.4 monthsrange 39-197 months). Results: Mothers had their first concerns regarding ASD when children were 23.6 +/- 11.6 months old, but formal diagnosis occurred at a mean +/- SD age of 59.6 +/- 40.5 months, corresponding to a 3-year delay. Most mothers felt discouraged to address their concerns due to negative experiences with health professionals. Conclusion: In Brazil, mothers perceived the first signs of ASD in their children at an age similar to that reported in other countries, but the diagnosis of ASD seemed to be delayed. Consistent with the literature, mothers reported negative experiences with health professionals during the pathway to achieving ASD diagnosis.Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES)Univ Fed Sao Paulo UNIFESP, Dept Psiquiatria, Ambulatorio Cognicao Social Marcos Tomanik Mercad, Sao Paulo, SP, BrazilUniv Presbiteriana Mackenzie, Programa Posgrad Disturbios Desenvolvimento, Sao Paulo, SP, BrazilUniv Fed Sao Paulo UNIFESP, Dept Psiquiatria, Ambulatorio Cognicao Social Marcos Tomanik Mercad, Sao Paulo, SP, BrazilWeb of Scienc
Association of the germline TP53 R337H mutation with breast cancer in southern Brazil
<p>Abstract</p> <p>Background</p> <p>The germline <it>TP53</it>-R337H mutation is strongly associated with pediatric adrenocortical tumors (ACT) in southern Brazil; it has low penetrance and limited tissue specificity in most families and therefore is not associated with Li-Fraumeni syndrome. However, other tumor types, mainly breast cancer, have been observed in carriers of several unrelated kindreds, raising the possibility that the R337H mutation may also contribute to breast tumorigenesis in a genetic background-specific context.</p> <p>Methods</p> <p>We conducted a case-control study to determine the prevalence of the R337H mutation by sequencing <it>TP</it>53 exon 10 in 123 women with breast cancer and 223 age- and sex-matched control subjects from southern Brazil. Fisher's test was used to compare the prevalence of the R337H.</p> <p>Results</p> <p>The R337H mutation was found in three patients but in none of the controls (p = 0.0442). Among the carriers, two had familial history of cancer meeting the Li-Fraumeni-like criteria. Remarkably, tumors in each of these three cases underwent loss of heterozygosity by eliminating the mutant <it>TP53 </it>allele rather than the wild-type allele. Polymorphisms were identified within the <it>TP53 </it>(R72P and Ins16) and <it>MDM2 </it>(SNP309) genes that may further diminish <it>TP53 </it>tumor suppressor activity.</p> <p>Conclusion</p> <p>These results demonstrate that the R337H mutation can significantly increase the risk of breast cancer in carriers, which likely depends on additional cooperating genetic factors. These findings are also important for understanding how low-penetrant mutant <it>TP53 </it>alleles can differentially influence tumor susceptibility.</p
Inherited germline TP53 mutation encodes a protein with an aberrant C-terminal motif in a case of pediatric adrenocortical tumor
Childhood adrenocortical tumor (ACT), a very rare malignancy, has an annual worldwide incidence of about 0.3 per million children younger than 15Â years. The association between inherited germline mutations of the TP53 gene and an increased predisposition to ACT was described in the context of the Li-Fraumeni syndrome. In fact, about two-thirds of children with ACT have a TP53 mutation. However, less than 10% of pediatric ACT cases occur in Li-Fraumeni syndrome, suggesting that inherited low-penetrance TP53 mutations play an important role in pediatric adrenal cortex tumorigenesis. We identified a novel inherited germline TP53 mutation affecting the acceptor splice site at intron 10 in a child with an ACT and no family history of cancer. The lack of family history of cancer and previous information about the carcinogenic potential of the mutation led us to further characterize it. Bioinformatics analysis showed that the non-natural and highly hydrophobic C-terminal segment of the frame-shifted mutant p53 protein may disrupt its tumor suppressor function by causing misfolding and aggregation. Our findings highlight the clinical and genetic counseling dilemmas that arise when an inherited TP53 mutation is found in a child with ACT without relatives with Li-Fraumeni-component tumors
Survey radiography and computerized tomography imaging of the thorax in female dogs with mammary tumors
<p>Abstract</p> <p>Background</p> <p>Accurate early diagnosis of lung metastases is important for establishing therapeutic measures. Therefore, the present study aimed to compare survey thoracic radiographs and computerized tomography (CT) scans to specifically identify lung metastases in female dogs with mammary tumors.</p> <p>Methods</p> <p>Twenty-one female dogs, weighing 3 to 34 kg and aged from 5 years to 14 years and 10 months, with mammary tumors were studied. In all dogs before the imaging examinations, fine-needle aspiration cytology of the mammary tumors was performed to confirm the diagnosis. Three-view thoracic radiographs were accomplished: right lateral, left lateral and ventrodorsal views. Sequential transverse images of the thorax were acquired on a spiral Scanner, before and after intravenous bolus injection of nonionic iodine contrast. Soft-tissue and lung windows were applied. All the mammary tumors were surgically removed and examined histologically.</p> <p>Results</p> <p>The correlation between the cytological and histological results regarding presence of malignancy was observed in only 17 cases. In radiographic examinations, no dog displayed signs of lung metastases or thorax chest lesions. CT detected lung metastasis in two cases, while small areas of lung atelectasis located peripherally were found in 28.57% of the dogs.</p> <p>Conclusion</p> <p>In this study population, spiral CT showed higher sensitivity than chest radiographies to detect lung metastasis; this indicates that CT should be performed on all female dogs with malignant mammary tumors.</p
Direct evidence for phosphorus limitation on Amazon forest productivity
The productivity of rainforests growing on highly weathered tropical soils is expected to be limited by phosphorus availability1. Yet, controlled fertilization experiments have been unable to demonstrate a dominant role for phosphorus in controlling tropical forest net primary productivity. Recent syntheses have demonstrated that responses to nitrogen addition are as large as to phosphorus2, and adaptations to low phosphorus availability appear to enable net primary productivity to be maintained across major soil phosphorus gradients3. Thus, the extent to which phosphorus availability limits tropical forest productivity is highly uncertain. The majority of the Amazonia, however, is characterized by soils that are more depleted in phosphorus than those in which most tropical fertilization experiments have taken place2. Thus, we established a phosphorus, nitrogen and base cation addition experiment in an old growth Amazon rainforest, with a low soil phosphorus content that is representative of approximately 60% of the Amazon basin. Here we show that net primary productivity increased exclusively with phosphorus addition. After 2 years, strong responses were observed in fine root (+29%) and canopy productivity (+19%), but not stem growth. The direct evidence of phosphorus limitation of net primary productivity suggests that phosphorus availability may restrict Amazon forest responses to CO2 fertilization4, with major implications for future carbon sequestration and forest resilience to climate change.The authors acknowledge funding from the UK Natural Environment Research Council (NERC), grant number NE/L007223/1. This is publication 850 in the technical series of the BDFFP. C.A.Q. acknowledges the grants from Brazilian National Council for Scientific and Technological Development (CNPq) CNPq/LBA 68/2013, CNPq/MCTI/FNDCT no. 18/2021 and his productivity grant. C.A.Q., H.F.V.C., F.D.S., I.A., L.F.L., E.O.M. and S.G. acknowledge the AmazonFACE programme for financial support in cooperation with Coordination for the Improvement of Higher Education Personnel (CAPES) and the National Institute of Amazonian Research as part of the grants CAPES-INPA/88887.154643/2017-00 and 88881.154644/2017-01. T.F.D. acknowledges funds from FundacAo de Amparo a Pesquisa do Estado de SAo Paulo (FAPESP), grant 2015/50488-5, and the Partnership for Enhanced Engagement in Research (PEER) programme grant AID-OAA-A-11-00012. L.E.O.C.A. thanks CNPq (314416/2020-0)
Reproductive biology of Synallaxis albescens (Aves: Furnariidae) in the cerrado of central Brazil
DNA methylation changes associated with risk factors in tumors of the upper aerodigestive tract
Cancers of the upper aerodigestive tract (UADT) are common forms of malignancy associated with tobacco and alcohol exposures, although human papillomavirus and nutritional deficiency are also important risk factors. While somatically acquired DNA methylation changes have been associated with UADT cancers, what triggers these events and precise epigenetic targets are poorly understood. In this study, we applied quantitative profiling of DNA methylation states in a panel of cancer-associated genes to a case-control study of UADT cancers. Our analyses revealed a high frequency of aberrant hypermethylation of several genes, including MYOD1, CHRNA3 and MTHFR in UADT tumors, whereas CDKN2A was moderately hypermethylated. Among differentially methylated genes, we identified a new gene (the nicotinic acetycholine receptor gene) as target of aberrant hypermethylation in UADT cancers, suggesting that epigenetic deregulation of nicotinic acetycholine receptors in non-neuronal tissues may promote the development of UADT cancers. Importantly, we found that sex and age is strongly associated with the methylation states, whereas tobacco smoking and alcohol intake may also influence the methylation levels in specific genes. This study identifies aberrant DNA methylation patterns in UADT cancers and suggests a potential mechanism by which environmental factors may deregulate key cellular genes involved in tumor suppression and contribute to UADT cancers.IARCIARCla Ligue National (Francaise) Contre le Cancerla Ligue National (Francaise) Contre le CancerNational Institutes of Health/National Cancer Institute (NIH/NCI), United StatesNational Institutes of Health/National Cancer Institute (NIH/NCI), United StatesAssociation pour la Recherche sur le Cancer (ARC, France)l'Association pour la Recherche sur le Cancer (ARC), Francela Ligue Nationale (Francaise) Contre le Cancer (Comite SaoneetLoire), Francela Ligue Nationale (Francaise) Contre le Cancer (Comite Saone-et-Loire), FranceSwiss Bridge AwardSwiss Bridge Awar
Eating patterns in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil): an exploratory analysis
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