Mexican Biobank advances population and medical genomics of diverse ancestries.

Latin America continues to be severely underrepresented in genomics research, and fine-scale genetic histories and complex trait architectures remain hidden owing to insufficient data1. To fill this gap, the Mexican Biobank project genotyped 6,057 individuals from 898 rural and urban localities across all 32 states in Mexico at a resolution of 1.8 million genome-wide markers with linked complex trait and disease information creating a valuable nationwide genotype-phenotype database. Here, using ancestry deconvolution and inference of identity-by-descent segments, we inferred ancestral population sizes across Mesoamerican regions over time, unravelling Indigenous, colonial and postcolonial demographic dynamics2-6. We observed variation in runs of homozygosity among genomic regions with different ancestries reflecting distinct demographic histories and, in turn, different distributions of rare deleterious variants. We conducted genome-wide association studies (GWAS) for 22 complex traits and found that several traits are better predicted using the Mexican Biobank GWAS compared to the UK Biobank GWAS7,8. We identified genetic and environmental factors associating with trait variation, such as the length of the genome in runs of homozygosity as a predictor for body mass index, triglycerides, glucose and height. This study provides insights into the genetic histories of individuals in Mexico and dissects their complex trait architectures, both crucial for making precision and preventive medicine initiatives accessible worldwide.

Unraveling the relationship between conditions of ultrasonic-assisted extraction of chia mucilage and viscosity.

BACKGROUND: The application of chia mucilage still remains restricted due to the difficulty in achieving high extraction yields. The effect of ultrasonic-assisted extraction (UAE) conditions (temperature, seed:water ratio and time) on the rheological properties of chia mucilage extracts and the relation to the proportion of translucent phase (TP) and opaque phase (OP) of the mucilage in the extract were evaluated. RESULTS: UAE allowed the efficient extraction of chia mucilage from chia seeds. The desired overall optimal combination to maximize both yield and apparent viscosity was achieved at a seed:water ratio 1:10, a temperature of 25.3 °C and 53.7 min extraction time; the optimal conditions to obtain the maximum yield and minimum apparent viscosity were a seed:water ratio close to 1:20, temperature of 48.8 °C and 208.4 min extraction time. CONCLUSION: The results obtained in the present work demonstrated that the differences in rheological properties of chia mucilage extracts are due to the extraction methods used. Therefore, it is possible to modulate the extraction conditions in order to obtain different characteristics of the mucilage, maintaining a high extraction yield. © 2022 Society of Chemical Industry.

Tumor de células de Sertoli-Leydig: a propósito de un caso y revisión de la literatura reciente / Ovarian Sertoli-Leydig cell tumour: a clinical case and recent basic literature review

INTRODUCCIÓN: Los tumores de células de Sertoli-Leydig son neoplasias de ovario infrecuentes, lo que dificulta su diagnóstico y tratamiento. OBJETIVO: Revisar y sintetizar el manejo actual de los tumores de células de Sertoli-Leydig. MÉTODO: Se realizó una revisión de la literatura reciente sobre tumores de células de Sertoli-Leydig, a propósito de un caso en nuestro centro. RESULTADOS: Los tumores de las células de Sertoli-Leydig son infrecuentes, con mayor incidencia en edades tempranas. Ante una paciente joven con una lesión anexial unilateral y signos de virilización deberán considerarse estos tumores dentro del diagnóstico diferencial. En los estadios iniciales y en pacientes jóvenes podrá plantearse un tratamiento quirúrgico que preserve la fertilidad, y la asociación de tratamiento adyuvante dependerá de la diferenciación y del estadiaje del tumor.

INTRODUCTION: Sertoli-Leydig cell tumors are infrequent ovarian neoplasms, which difficults their diagnosis and treatment. Objective: To review and synthesize the current management of the Sertoli-Leydig cell tumor. METHOD: A review of the recent literature regarding the Sertoli-Leydig cell tumor was carried out, regarding a case in our center. RESULTS: Sertoli-Leydig cell tumors are an infrequent entity, with a higher incidence in early ages. In a young patient with a unilateral adnexal lesion and signs of virilization, these tumors should be considered within the differential diagnosis. In early stages and young patients, a surgical treatment that preserves fertility may be considered, and the association of adjuvant treatment will depend on the differentiation and staging of the tumor.

Imputation Performance in Latin American Populations: Improving Rare Variants Representation With the Inclusion of Native American Genomes.

Current Genome-Wide Association Studies (GWAS) rely on genotype imputation to increase statistical power, improve fine-mapping of association signals, and facilitate meta-analyses. Due to the complex demographic history of Latin America and the lack of balanced representation of Native American genomes in current imputation panels, the discovery of locally relevant disease variants is likely to be missed, limiting the scope and impact of biomedical research in these populations. Therefore, the necessity of better diversity representation in genomic databases is a scientific imperative. Here, we expand the 1,000 Genomes reference panel (1KGP) with 134 Native American genomes (1KGP + NAT) to assess imputation performance in Latin American individuals of mixed ancestry. Our panel increased the number of SNPs above the GWAS quality threshold, thus improving statistical power for association studies in the region. It also increased imputation accuracy, particularly in low-frequency variants segregating in Native American ancestry tracts. The improvement is subtle but consistent across countries and proportional to the number of genomes added from local source populations. To project the potential improvement with a higher number of reference genomes, we performed simulations and found that at least 3,000 Native American genomes are needed to equal the imputation performance of variants in European ancestry tracts. This reflects the concerning imbalance of diversity in current references and highlights the contribution of our work to reducing it while complementing efforts to improve global equity in genomic research.

QSAR Classification Models for Predicting the Activity of Inhibitors of Beta-Secretase (BACE1) Associated with Alzheimer's Disease.

Alzheimer's disease is one of the most common neurodegenerative disorders in elder population. The ß-site amyloid cleavage enzyme 1 (BACE1) is the major constituent of amyloid plaques and plays a central role in this brain pathogenesis, thus it constitutes an auspicious pharmacological target for its treatment. In this paper, a QSAR model for identification of potential inhibitors of BACE1 protein is designed by using classification methods. For building this model, a database with 215 molecules collected from different sources has been assembled. This dataset contains diverse compounds with different scaffolds and physical-chemical properties, covering a wide chemical space in the drug-like range. The most distinctive aspect of the applied QSAR strategy is the combination of hybridization with backward elimination of models, which contributes to improve the quality of the final QSAR model. Another relevant step is the visual analysis of the molecular descriptors that allows guaranteeing the absence of information redundancy in the model. The QSAR model performances have been assessed by traditional metrics, and the final proposed model has low cardinality, and reaches a high percentage of chemical compounds correctly classified.

Cinnamaldehyde and related phenylpropanoids, natural repellents, and insecticides against Sitophilus zeamais (Motsch.). A chemical structure-bioactivity relationship.

BACKGROUND: The insecticidal and repellent effects on adult Sitophilus zeamais of 12 cinnamaldehyde-related compounds was evaluated by contact toxicity bioassays and a two-choice olfactometer. To determine non-toxicity in mammals, body weight, serum biochemical profiles, liver weight, physiological parameters, sperm motility, and histopathological data were obtained as complementary information in C57BL/6 mice treated with the best natural compound. RESULTS: Based on 24 h LC95 and LC50 values, α-methyl-cinnamaldehyde and cinnamaldehyde exhibited better insecticidal action than the other compounds. The best repellent effect was observed with α-bromo-cinnamaldehyde, which even repelled at the lowest concentration studied (0.28 µmol L-1 ). The evaluation of a quantitative structure-activity relationship found a linear relationship between the LC50 values for adult weevil toxicity and dipolo with Q values (giving the difference between orbital electronegativity carbon 1 and orbital electronegativity carbon 3 of the molecule) in cinnamaldehyde-related compounds. The polar surface and Log P descriptors also revealed a linear relationship with the S. zeamais repellent effect for cinnamaldehyde analogues. Cinnamaldehyde did not show toxicity in the parameters evaluated in mice. CONCLUSION: From the phenylpropanoid components studied, the natural compound that had the best insecticidal and repellent action against S. zeamais was cinnamaldehyde. It presented no mammalian toxicity. © 2018 Society of Chemical Industry.

Adsorption-desorption and hysteresis phenomenon of tebuconazole in Colombian agricultural soils: Experimental assays and mathematical approaches.

The adsorption-desorption, hysteresis phenomenon, and leachability of tebuconazole were studied for Inceptisol and Histosol soils at the surface (0-10 cm) and in the subsurface (40-50 cm) of an agricultural region from Colombia by the batch-equilibrium method and mathematical approaches. The experimental Kfa and Kd (L kg-1) values (7.9-289.2) decreased with depth for the two Inceptisols and increased with depth for the Histosol due to the organic carbon content, aryl and carbonyl carbon types. Single-point and desorption isotherms depended on adsorption reversibility and suggested that tebuconazole showed hysteresis; which can be adequately evaluated with the single-point desorption isotherm and the linear model using the hysteresis index HI. The most suitable mathematical approach to estimate the adsorption isotherms of tebuconazole at the surface and in the subsurface was that considering the combination of the n-octanol-water partition coefficient, pesticide solubility, and the mass-balance concept. Tebuconazole had similar moderate mobility potential as compared with the values of other studies conducted in temperate amended and unamended soils, but the risk of the fungicide to pollute groundwater sources increased when the pesticide reached subsurface soil layers, particularly in the Inceptisols.

Hybridizing Feature Selection and Feature Learning Approaches in QSAR Modeling for Drug Discovery.

Quantitative structure-activity relationship modeling using machine learning techniques constitutes a complex computational problem, where the identification of the most informative molecular descriptors for predicting a specific target property plays a critical role. Two main general approaches can be used for this modeling procedure: feature selection and feature learning. In this paper, a performance comparative study of two state-of-art methods related to these two approaches is carried out. In particular, regression and classification models for three different issues are inferred using both methods under different experimental scenarios: two drug-like properties, such as blood-brain-barrier and human intestinal absorption, and enantiomeric excess, as a measurement of purity used for chiral substances. Beyond the contrastive analysis of feature selection and feature learning methods as competitive approaches, the hybridization of these strategies is also evaluated based on previous results obtained in material sciences. From the experimental results, it can be concluded that there is not a clear winner between both approaches because the performance depends on the characteristics of the compound databases used for modeling. Nevertheless, in several cases, it was observed that the accuracy of the models can be improved by combining both approaches when the molecular descriptor sets provided by feature selection and feature learning contain complementary information.

Affinity chromatography matrices for depletion and purification of casein glycomacropeptide from bovine whey.

Casein glycomacropeptide (CMP) is a 64- amino acid peptide found in cheese whey, which is released after κ-casein specific cleavage by chymosin. CMP lacks aromatic amino acids, a characteristic that makes it usable as a nutritional supplement for people with phenylketonuria. CMP consists of two nonglycosylated isoforms (aCMP A and aCMP B) and its different glycosylated forms (gCMP A and gCMP B). The most predominant carbohydrate of gCMP is N-acetylneuraminic acid (sialic acid). Here, we developed a CMP purification process based on the affinity of sialic acid for wheat germ agglutinin (WGA). After formation of chitosan beads and adsorption of WGA, the agglutinin was covalently attached with glutaraldehyde. Two matrices with different WGA density were assayed for CMP adsorption. Maximum adsorption capacities were calculated according to the Langmuir model from adsorption isotherms developed at pH 7.0, being 137.0 mg/g for the matrix with the best performance. In CMP reduction from whey, maximum removal percentage was 79% (specifically 33.7% of gCMP A and B, 75.8% of aCMP A, and 93.9% of aCMP B). The CMP was recovered as an aggregate with an overall yield of 64%. Therefore, the matrices developed are promising for CMP purification from cheese whey. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 33:171-180, 2017.

HPV-16 infection modifies overall survival of Puerto Rican HNSCC patients.

BACKGROUND: HPV-16 modifies the overall survival (OS) of patients with oropharyngeal cancer (OPSCC). HPV-16 has been established as risk factor for OPSCC, but HPV-16 infection may also reside in the larynx and oral cavity. We evaluated HPV-16 status on OS of Head and Neck Squamous Cell Carcinoma (HNSCC) patients. METHODS: HPV-16 infection was confirmed by amplification of E6 and E7 viral oncogenes through PCR assay and E6 IHC in 185 HNSCC samples. Associations between HPV-16 status and clinicopathological parameters were performed using Fisher's exact test and x(2). Survival analysis was completed using Kaplan-Meier estimator and multivariate Cox regression analysis. RESULTS: OS of HPV-16 positive patients was longer compared to HPV-16 negative patients (P = 0.002). HPV-16 positive tumors of the larynx (LSCC) and pharynx (PSCC) showed improved OS compared to HPV-16 negative tumors. Also, HPV-16 positive patients exposed to radiotherapy presented a better survival. CONCLUSIONS: HPV-16 status has a positive prognostic value in HNSCC. Addition of HPV-16 status to the TNM staging can provide better assessment in prognosis and guide treatment for HNSCC patients.

Targeting miR-21-3p inhibits proliferation and invasion of ovarian cancer cells.

MicroRNA-21 is overexpressed in most cancers and has been implicated in tumorigenesis. Accumulating evidence supports a central role for the miR-21 guide strand (miR-21-5p) in ovarian cancer initiation, progression, and chemoresistance. However, there is limited information regarding the biological role of the miR-21 passenger strand (miR-21-3p) in ovarian cancer cells. The aim of this study was to investigate the role of miR-21-3p and its target genes in cisplatin-resistant ovarian cancer cells. Expression profiling of miR-21-5p and miR-21-3p was performed in a panel of cancer cells by qPCR. Colony formation and invasion assays were carried out on ovarian and prostate cancer cells transfected with miR-21-5p and miR-21-3p inhibitors. Dual luciferase reporter assays were used to identify the miR-21-3p target genes in ovarian cancer cells. Our results show that miR-21-5p had higher expression levels compared to miR-21-3p on a panel of cancer cells. Moreover, inhibition of miR-21-5p or miR-21-3p resulted in a significant decrease in ovarian and prostate cancer cell proliferation and invasion. Luciferase reporter assays identify RNA Binding Protein with Multiple Splicing (RBPMS), Regulator of Chromosome Condensation and POZ Domain Containing Protein 1 (RCBTB1), and Zinc Finger protein 608 (ZNF608) as miR-21-3p target genes. SiRNA-induced RBPMS silencing reduced the sensitivity of ovarian cancer cells to cisplatin treatment. Immunohistochemical analyses of serous ovarian cancer patient samples suggest a significant decrease of RBMPS levels when compared to normal ovarian epithelium. Taken together, the data generated in this study suggests a functional role for miR-21-3p in ovarian cancer and other solid tumors.

Prevalencia del virus papiloma humano en pacientes con diagnóstico de carcinoma escamoso de la cavidad oral / Human papilloma virus prevalence in patients diagnosed with squamous carcinoma oral cavity

Aim: To establish the prevalence of HPV in patients with diagnose of Oral Squamous cell carcinoma, treated in the Instituto nacional del Cáncer in fresh tumoral samples. methods: Cross-sectional study. The inclusion criteria were patients over 18 years, histological diagnosis of Oral Squamous cell carcinoma, that haven’t received any previous cancer treatment, in normal physical and mental conditions. All patients signed an informed consent. Samples consisting of fresh biopsies of lesions with clinical and pathological diagnosis were made. The samples were processed in the Programme of Virology, Faculty of Medicine, Universidad de Chile, through PCR and genotyped by Linear Array® (ROCHE). Results: The prevalence of VPH obtained in this patients was of 9.09% (2/22), corresponding 1 to VPH 56. The positive patients for VPH resulted to be a man of 35 years and a woman of 73 years (9%). Conclusion: The prevalence of HPV in this type of patients was 9.09%, similar than the international publications.

Objetivos: Determinar la prevalencia del virus papiloma humano (VPH) en pacientes con diagnóstico de carcinoma escamoso de la cavidad oral (COCE), atendidos en el Instituto nacional del Cáncer (INCANCER). material y método: Estudio de corte transversal. Criterios de inclusión: pacientes mayores de 18 años, con diagnóstico histológico de COCE, que no hubiesen recibido ningún tratamiento oncológico previo, en condiciones físicas y mentales normales. Todos los pacientes firmaron el consentimiento informado. Se les realizó una entrevista y se tomaron muestras que consistieron en biopsias frescas de lesiones con diagnóstico clínico y anatomopatológico de COCE. Las muestras se procesaron en el Programa de Virología de la Facultad de Medicina de la Universidad de Chile, a través de PCR y se genotipificaron mediante Linear Array® (ROCHE). Resultados: La prevalencia de VPH obtenida en estos pacientes fue de un 9,09% (2/22), correspondiendo 1 a VPH 56. Los pacientes positivos para VPH resultaron ser un hombre de 35 años y una mujer de 73 años (9%). Conclusión: La prevalencia del VPH en este tipo de pacientes fue de 9,09%, similar a las publicaciones internacionales.

An uncommon presentation of follicular thyroid carcinoma: when chronic back pain should raise a flag.

Follicular thyroid carcinoma is the second most common type of thyroid cancer, and its incidence has increased dramatically in recent years. Although it typically presents as a thyroid nodule, it can spread to distant sites via hematogenous dissemination. Bone metastasis is diagnosed clinically in 2%-13% of patients with differentiated thyroid cancer; nevertheless spinal cord compression complicating thyroid carcinoma is rare and only few cases has been reported in the literature. This case illustrates a strange case of a minimally invasive follicular carcinoma that showed an aggressive behavior, and thus the importance of considering metastatic thyroid carcinoma in the differential diagnosis of chronic back pain progressing to spinal cord compression carrying a severe morbidity.

The LonB protease controls membrane lipids composition and is essential for viability in the extremophilic haloarchaeon Haloferax volcanii.

Although homologs of the ATP-dependent Lon protease exist in all domains of life, the relevance of this protease in archaeal physiology remains a mystery. In this study, we have constructed and phenotypically characterized deletion and conditional lon mutants in the model haloarchaeon Haloferax volcanii to elucidate the role of the unusual membrane-bound LonB protease in archaea. Hvlon could be deleted from the chromosome only when a copy of the wild type gene was provided in trans suggesting that Lon is essential for survival in this archaeon. Successful complementation of the lethal phenotype of ΔHvlon was attained by expression of the heterologous protease gene Nmlon from the haloalkaliphilic archaeon Natrialba magadii, meaning that the biological function of Lon is conserved in these organisms. Suboptimal cellular levels of Lon protein affected growth rate, cell shape, cell pigmentation, lipid composition and sensitivity to various antibiotics. The contents of bacterioruberins and some polar lipids were increased in the lon mutants suggesting that Lon is linked to maintenance of membrane lipid balance which likely affects cell viability in this archaeon. The phenotypes associated to a membrane-bound LonB protease mutant were examined for the first time providing insight on the relevance of this protease in archaeal physiology.

UNCOMMON PRESENTATION OF FOLLICULAR THYROID CARCINOMA: WHEN CHRONIC BACK PAIN SHOULD RAISE A FLAG.

Follicular thyroid carcinoma is the second most common type of thyroid cancer, and its incidence has increased dramatically in recent years. Although it typically presents as a thyroid nodule, it can spread to distant sites via hematogenous dissemination. Spinal cord compression complicating thyroid carcinoma is rare with only few cases reported in the literature. This case illustrates a minimally invasive follicular carcinoma that showed such an aggressive behavior, and thus the importance of considering metastatic thyroid carcinoma in the differential diagnosis of chronic back pain, which may possibly progress to spinal cord compression carrying severe morbidity.

QSPR models for predicting log P(liver) values for volatile organic compounds combining statistical methods and domain knowledge.

Volatile organic compounds (VOCs) are contained in a variety of chemicals that can be found in household products and may have undesirable effects on health. Thereby, it is important to model blood-to-liver partition coefficients (log P(liver)) for VOCs in a fast and inexpensive way. In this paper, we present two new quantitative structure-property relationship (QSPR) models for the prediction of log P(liver), where we also propose a hybrid approach for the selection of the descriptors. This hybrid methodology combines a machine learning method with a manual selection based on expert knowledge. This allows obtaining a set of descriptors that is interpretable in physicochemical terms. Our regression models were trained using decision trees and neural networks and validated using an external test set. Results show high prediction accuracy compared to previous log P(liver) models, and the descriptor selection approach provides a means to get a small set of descriptors that is in agreement with theoretical understanding of the target property.

Interfacial and foaming interactions between casein glycomacropeptide (CMP) and propylene glycol alginate.

Proteins and polysaccharides are widely used in food formulation. While most of the proteins are surface active, only few polysaccharides can adsorb at the air-water interface; this is the case of propylene glycol alginates (PGA). It is known that casein glycomacropeptide (CMP), a bioactive polypeptide derived from κ-casein by the action of chymosin, presents a great foaming capacity but provides unstable foams. So, the objective of this work was to analyze the impact of mixing CMP and a commercial variety of PGA, Kelcoloid O (KO), on the interfacial and foaming properties at pH 7.0. It was determined the surface pressure isotherm, the dynamics of adsorption and the foaming properties for CMP, KO and the mixed system CMP-KO. CMP dominated the surface pressure of CMP-KO mixed system. The presence of KO synergistically improved the viscoelastic properties of surface film. The foaming capacity of CMP was altered by KO. KO foam presented a higher stability than CMP foam and it controlled the stability against drainage and the initial collapse in the mixed foam.

Interactions between ß-lactoglobulin and casein glycomacropeptide on foaming.

The aim of this work was to study the effect of interactions between casein glycomacropeptide (CMP) and ß-lactoglobulin (ß-lg) at pH 6.5 and 3.5 on the foaming properties of the mixed systems with different CMP:ß-lg ratios. The foaming properties were determined by the bubbling method with a Foamscan instrument. A highest overall foam capacity (OFC), foaming capacity (FC) and mainly stability of mixed foams at pH 3.5, as compared to the mixed foams at pH 6.5 or the foams of CMP and ß-lg was observed. At pH 6.5, the stability of mixed foams decreased with increasing the CMP content, while OFC and FC values were similar to ß-lg foam. The performance of the mixed systems was discussed in relation with the interactions between CMP and ß-lg in the aqueous phase (as observed by dynamic light scattering and differential scanning calorimetry in previous works).

Bioavailability, ecotoxicity, and geological characteristics of trace lead in sediments from two sites on Negro River, Uruguay, South America.

Bioassays of two sites along the Rio Negro in Uruguay indicate ecotoxicity, which could be attributable to trace concentrations of lead in river sediments. Monthly samples at two sites at Baygorria and Bonete locations were analyzed for both particle size and lead. Lead was determined by atomic spectrometry in river water and sediment and particle size by sieving and sedimentation. Data showed that Baygorria's sediments have greater percentage of clay than Bonete's (20.4 and 5.8%, respectively). Lead was measurable in Baygorria's sediments, meanwhile in Bonete's, it was always below the detection limit. In water samples, lead was below detection limit at both sites. Bioassays using sub-lethal growth and survival test with Hyalella curvispina amphipod, screening with bioluminescent bacteria Photobacterium leiognathi, and acute toxicity bioassay with Pimephales promelas fish indicated toxicity at Baygorria, with much less effect at Bonete. Even though no lethal effects could be demonstrated, higher sub-lethal toxicity was found in samples from Baygorria site, showing a possible concentration of the contaminant in the clay fraction.

Comportamiento de las enfermedades periodontales en adolescentes / Behavior of the periodontal diseases in adolescents

En nuestro sistema nacional de salud son incalculables los esfuerzos realizados en función de dotar a la Estomatología y dentro de ella a la Periodontología, de los medios más modernos y eficaces en las actividades preventivo curativas contra las enfermedades periodontales. Objetivo: determinar el comportamiento de las enfermedades periodontales en adolescentes de los consultorios 11, 51 y 64 del Área de Salud Norte perteneciente al Policlínico Docente Joaquín de Agüero y la Clínica Estomatológica Docente La Vigía. Método: se realizó un estudio descriptivo en adolescentes de once a quince años. La muestra quedó conformada por cuarenta adolescentes a los cuales se le realizó una encuesta de conocimientos sobre salud bucal. Resultados: predominó el sexo femenino, el nivel de información sobre salud bucal fue aceptable, predominaron los procesos inflamatorios. Conclusiones: los adolescentes que más concurrieron al estudio fueron los de 14 años. Más de la mitad de los adolescentes estudiados estaban afectados por la enfermedad periodontal.

In our national system of health are incalculable the efforts carried out in function of endowing Odontology, and inside her to Periodontology, of the most modern and effective means in the preventive curative activities against the periodontal diseases. Objective: to determine the behavior of the periodontal diseases in adolescents from the doctors´ office 11, 51 and 64 of the North Health Area belonging to the Teaching Polyclinic "Joaquín de Agüero" and the Teaching Odontology Clinic "La Vigía". Method: a descriptive study in adolescents from eleven to fifteen years was performed. The sample was constituted by forty adolescents to whom a survey of knowledge on oral health was carried out. Results: the feminine sex prevailed, the level of information on oral health was acceptable, and the inflammatory processes predominated. Conclusions: adolescents that most concurred to the study were those of 14 years. More than the half of the studied adolescents was affected by the periodontal disease.