ε-tubulin is essential in Tetrahymena thermophila for the assembly and stability of basal bodies.

Basal bodies and centrioles are conserved microtubule-based organelles the improper assembly of which leads to a number of diseases, including ciliopathies and cancer. Tubulin family members are conserved components of these structures that are integral to their proper formation and function. We have identified the ε-tubulin gene in Tetrahymena thermophila and detected the protein, through fluorescence of a tagged allele, to basal bodies. Immunoelectron microscopy has shown that ε-tubulin localizes primarily to the core microtubule scaffold. A complete genomic knockout of ε-tubulin has revealed that it is an essential gene required for the assembly and maintenance of the triplet microtubule blades of basal bodies. We have conducted site-directed mutagenesis of the ε-tubulin gene and shown that residues within the nucleotide-binding domain, longitudinal interacting domains, and C-terminal tail are required for proper function. A single amino acid change of Thr150, a conserved residue in the nucleotide-binding domain, to Val is a conditional mutation that results in defects in the spatial and temporal assembly of basal bodies as well as their stability. We have genetically separated functions for the domains of ε-tubulin and identified a novel role for the nucleotide-binding domain in the regulation of basal body assembly and stability.

Dental anomalies in different growth and skeletal malocclusion patterns.

OBJECTIVES: To evaluate prevalence, distribution, and sexual dimorphism of dental anomalies (DA) among different skeletal malocclusions (SM) and growth patterns (GP) under the hypothesis that specific clinical patterns exist and may indicate common etiological roots. MATERIALS AND METHODS: A total of 1047 orthodontic records of patients older than 8 years were evaluated. The SN-GoGn angle was used to classify GP (hypodivergent, normal, and hyperdivergent), and the ANB angle was used to verify SM (Angle Classes I, II, and III). These assessments were done from lateral cephalometric radiographs. DA were diagnosed using panoramic radiographs by one calibrated investigator. Odds ratios, chi-square, and Student's t-tests were used. RESULTS: Of the subjects, 56.7% were female, with mean age of 16.41 (±10.61) years. The prevalence of DA was 15.7%. Impaction and tooth agenesis were the most prevalent DA, with relative frequencies of 14.4% and 9.7%, respectively. DA were most prevalent in Class III SM (80.8%) and in hypodivergent GP (82.5%), although this was not statistically significant. Tooth agenesis ( P < .01) and microdontia ( P = .025) were significantly more common among hypodivergent GP and Class III SM, respectively. CONCLUSIONS: The results of this study support the idea that DA are preferentially associated with certain patterns of malocclusion.

Third molar agenesis as a potential marker for craniofacial deformities.

The identification of clinical patterns of tooth agenesis in individuals born with craniofacial deformities may be a useful tool for risk determination of these defects. We hypothesize that specific craniofacial deformities are associated with third molar agenesis. OBJECTIVE: The aim of this study was to identify if third molar agenesis could have a relation with other craniofacial structure alterations, such as cleft lip and palate, skeletal malocclusion, or specific growth patterns in humans. DESIGN: Data were obtained from 550 individuals ascertained as part of studies aiming to identify genetic contributions to oral clefts. 831 dental records of patients aged over eight years seeking orthodontic treatment were also included. SN-GoGn angle were used to classify the growth pattern (hypo-divergent, normal and hyper-divergent), and the ANB angle was used to verify the skeletal malocclusion pattern (Class I, II and III). Panoramic radiographs were used to determine third molar agenesis. RESULTS: A high frequency of third molar agenesis among individuals born with cleft lip with or without cleft palate (55%), as well as among their relatives (93.5%) was found. Third molar agenesis was not associated to skeletal malocclusion or growth pattern. CONCLUSION: It appears that third molar agenesis is associated with the disturbances that lead to cleft lip and palate.

DisAp-dependent striated fiber elongation is required to organize ciliary arrays.

Cilia-organizing basal bodies (BBs) are microtubule scaffolds that are visibly asymmetrical because they have attached auxiliary structures, such as striated fibers. In multiciliated cells, BB orientation aligns to ensure coherent ciliary beating, but the mechanisms that maintain BB orientation are unclear. For the first time in Tetrahymena thermophila, we use comparative whole-genome sequencing to identify the mutation in the BB disorientation mutant disA-1. disA-1 abolishes the localization of the novel protein DisAp to T. thermophila striated fibers (kinetodesmal fibers; KFs), which is consistent with DisAp's similarity to the striated fiber protein SF-assemblin. We demonstrate that DisAp is required for KFs to elongate and to resist BB disorientation in response to ciliary forces. Newly formed BBs move along KFs as they approach their cortical attachment sites. However, because they contain short KFs that are rotated, BBs in disA-1 cells display aberrant spacing and disorientation. Therefore, DisAp is a novel KF component that is essential for force-dependent KF elongation and BB orientation in multiciliary arrays.

A successful dental management in a child with Cornelia de Lange Syndrome: rare case of Cornelia de Lange Syndrome in child / O sucesso do manejo odontológico em criança com Síndrome Cornelia de Lange: um caso raro da Síndrome Cornelia de Lange em criança

Background: the Cornelia de Lange Syndrome (CDLs) is a rare and complex syndrome characterized, basically, by psychomotor retardation associated with a number of congenital malformations. Aims: this paper reports the case of an 11-year-old female child diagnosed with Cornelia de Lange Syndrome (CdLS) and her successful dental management. Case report: the patient had severe mental retardation, definite negative behavior and the clinical findings included oral and physical changes. The patient's oral hygiene was deficient with the presence of calculus and gingivitis, besides several active caries lesions in permanent and deciduous dental elements. The treatment consisted in guidance for caregivers about oral hygiene and diet, and the dental procedures were performed under general anesthesia. Currently, the patient is accompanied by monthly follow-ups. Conclusions: the lack of knowledge about oral hygiene and cariogenic diets was identified as a one of the reasons for the oral diseases present. Due to the need to care for the other more serious and complex health problems, the oral diseases had evolved faster than usual and thus were difficult to treat and maintain thereafter. Under such conditions, the dentist plays a key role within a multidisciplinary team. From the guidance and knowledge provided in the dental clinic, there was a significant improvement in the life quality of the child and her family

The two human centrin homologues have similar but distinct functions at Tetrahymena basal bodies.

Centrins are a ubiquitous family of small Ca(2+)-binding proteins found at basal bodies that are placed into two groups based on sequence similarity to the human centrins 2 and 3. Analyses of basal body composition in different species suggest that they contain a centrin isoform from each group. We used the ciliate protist Tetrahymena thermophila to gain a better understanding of the functions of the two centrin groups and to determine their potential redundancy. We have previously shown that the Tetrahymena centrin 1 (Cen1), a human centrin 2 homologue, is required for proper basal body function. In this paper, we show that the Tetrahymena centrin 2 (Cen2), a human centrin 3 homologue, has functions similar to Cen1 in basal body orientation, maintenance, and separation. The two are, however, not redundant. A further examination of human centrin 3 homologues shows that they function in a manner distinct from human centrin 2 homologues. Our data suggest that basal bodies require a centrin from both groups in order to function correctly.

Análise da eficácia de métodos alternativos de higiene bucal / Evaluation of the efficacy of bucal hygiene alternative methods

Introdução - Devido às diferenças econômicas que atingem grande parte da população, torna-se difícil a aquisição da escova e da fita dental convencionais. Nesse sentido, o presente trabalho visa analisar a eficácia da remoção de biofilme dental com escovas e fitas dentais alternativos e comparar a eficácia desses aos métodos convencionais de higienização. Material e métodos - As escovas alternativas foramconfeccionadas com palitos de picolé e bucha vegetal. Já as fitas dentais alternativas foram obtidas de tiras de saco plástico de 50kg de farinha de trigo. Participaram da pesquisa 45 alunos da Faculdade de Odontologia da Universidade Federal do Pará em duas etapas: evidenciação 1 (remoção do biofilme evidenciado com escovas efitas dentais convencionais) e evidenciação 2 (remoção do biofilme evidenciado com escovas e fita dentais alternativas), com intervalo de 7 dias entre elas. Foi utilizado o índice de O’Leary para quantificar o biofilme nas duas etapas do experimento.Resultados - Foi observado significativa eficácia na remoção do biofilme dental,tanto da escova, quanto da fita dental alternativa com nível de significância p<0,05. Os métodos alternativos e convencionais de remoção do biofilme não demonstraram diferenças estatisticamente significantes entre eles. Conclusão - Escova e fita dentalalternativas podem ser utilizadas com segurança para a higienização bucal, sendo uma opção de custo mais acessível e de fácil confecção, no qual aproximam o acesso à saúde bucal da população carente.

Introduction - Due to the economic differences that affect the most of population, becomes difficult the acquisition of conventional tooth brush and dental tape. Accordingly, this paper aim to evaluate the effectiveness removal of dental biofilm with alternative tooth brush and dental tape and to compare its effectiveness againstconventional methods of cleaning. Materials and methods - The alternative tooth brush was confectioned with Popsicle stick and vegetal bush. The alternative dental tape was obtained from strips plastic bag of 50kg. Forty five students of the Instituteof Odontology of Federal University of Para participated in two steps: evidence 1 (evidenced biofilm remotion with conventional tooth brush and dental tape) and evidence 2 (evidenced biofilm remotion with alternatives tooth brush and dental tape), with a break of 7 days between the evidences. The O’leary index was used to quantify the biofilm in two steps of the experimental procedure. Results - It was observed a significant efficacy in the dental biofilm remotion, that both alternative tooth brush anddental tape obtained a significance level of p<0,05. The alternative and conventional methods of removal of biofilm do not demonstrated statistically significant differences between them. Conclusion: Alternative tooth brush and dental tape can be used with safety for bucal cleanness, suggesting a cheaper option and an easier confection, turning possible the access of the bucal health to poor population.