Alcina Maria Vinhaes Bittencourt

Pigmentary retinopathy due to Bardet-Biedl syndrome: case report and literature review

Bardet-Biedl syndrome (BBS) is a rare autosomal recessive disorder with clinical and genetic heterogeneity. This syndrome was first described by Laurence and Moon in 1866 and additional cases were described by Bardet and Biedl between 1920 and 1922. The main features are obesity, polydactyly, pigmentary retinopathy, learning disabilities, various degrees of intellectual impairment, hypogonadism, and renal abnormalities. Bardet-Biedl syndrome is both phenotypically and genetically heterogeneous. Clinical diagnosis is based on the presence of 4 of the 5 cardinal features. The authors present a typical case of pigmentary retinopathy due to Bardet-Biedl syndrome and made a brief commentary about the diseases cardinal manifestations.

Relationship between vitiligo and Hashimoto's thyroiditis

B Background : Vitiligo is a multifactorial acquired depigmenting disorder, characterized by a spontaneous loss of functional melanocytes from the epidermis. Vitiligo and Hashimotos thyroiditis (HT) often occur in association and seem to be characterized by an autoimmune process. The vitiligo associated with HT suggests genetic homologies between them. Objective : To identify protein sequence homology between melanocyte protein (Pmel) and thyroid peroxidase (TPO), using bioinformatics tools, to propose an initial mechanism which could explain the production of cross-reacting autoantibodies to melanocyte and TPO. Methods : We performed a comparison between Pmel and TPO amino acids (AA) sequences, available on the National Center for Biotechnology Information (NCBI) database by BLAST (Basic Local Alignment Search Tool) in order to find local homology regions between the AA sequences. Results : The homology sequence between the Pmel and TPO ranged from 21.0 % (19 identical residues out of 90 AA in the sequence) to 55.0% (6 identical residues out of 11 AA in the sequence). The identical alignments presented relatively high E values due to presence of short alignment. Conclusion : Bioinformatics data suggest a possible pathological link between Pmel and TPO. Sequence homology between Pmel and TPO may present a molecular mimicry suggesting the possibility of antigen crossover between Pmel and TPO that might represent an immunological basis for vitiligo associated with HT.

Protein molecular modeling of genetic markers for thyroid cancer

Introduction: The advances in thyroid molecular biology studies provide not only insight into thyroid diseases but accurate diagnosis of thyroid cancer. Objective: Design a tutorial on protein molecular modeling of genetic markers for thyroid cancer. Methods: The proteins were selected using the Protein Data Bank sequence and the basic local alignment search tool (BLAST) algorithm. The obtained sequences were aligned with the Clustal W multiple alignment algorithms. For the molecular modeling, three-dimensional structures were generated from this set of constraints with the SWISS-MODEL, which is a fully automated protein structure homology-modeling server, accessible via the ExPASy web server. Results: We demonstrated protein analysis, projection of the molecular structure and protein homology of the following molecular markers of thyroid cancer: receptor tyrosine kinase (RET) proto-oncogene; neurotrophic tyrosine kinase receptor 1 (NTRK1) proto-oncogene; phosphatase and tensin homolog (PTEN); tumor protein p53 (TP53) gene; phosphoinositide 3-kinase/threonine protein kinase (PI3K/AKT); catenin beta 1 (CTNNB1); paired box 8-peroxisome proliferator-activated receptor gamma (PAX8-PPARG); rat sarcoma viral oncogene (RAS); B-raf proto-oncogene, serine/threonine kinase (BRAF); and thyroid-stimulating hormone receptor (TSHR). Conclusion: This study shows the importance of understanding the molecular structure of the markers for thyroid cancer through bioinformatics, and consequently, the development of more effective new molecules as alternative tools for thyroid cancer treatment.

Homologies between Bauhinia forficata Link subsp. pruinosa and pancreatic beta-cell specific transcriptional activator: a starting point for drug design new in diabetes?

Materials and methods Were performed the comparison between the AA sequence of the GenBank: CAA94019.1-ribulose 1,5biphosphate carboxylase large subunit, partial (chloroplast) [Bauhinia forficata subsp. pruinosa] and GenBank: BAC20389.1-pancreatic beta-cell specific transcriptional activator [Homo sapiens], available in the database of NCBI with the Basic Local Alignment Search Tool (BLASTp) software. Results The homology between the ribulose 1,5-biphosphate carboxylase large subunit, partial (chloroplast) [Bauhinia forficata subsp. pruinosa] and the pancreatic beta-cell specific transcriptional activator [Homo sapiens] ranged from 48.0% to 63.0% (Fig.1).