Universidad Hipocrates

Periodontal disease is one of the most common inflammatory disorders in humans. Gingivitis is the mildest form of periodontal disease and its progression can lead to periodontitis, an inflammatory disease characterized by soft tissue damage that can lead to progressive destruction of the periodontal ligament and alveolar bone. Diverse populations of immune cells are involved in periodontal disease. Myeloid-derived suppressor cells (MDSCs) represent a heterogeneous group of immature myeloid cells derived from hematopoietic precursor cells and exhibit T cell immunosuppressive functions that are thought to be involved in periodontal disease. Therefore, MDSCs have been recently analyzed in the context of this disease. In this review, we discuss the most recent advances in the characterization of the biological aspects, subpopulations, and traffic of MDSCs, as well as their immunosuppressive and osteoclastogenic activity in the context of periodontal disease and in the presence of key periodontal pathogens. Free Access https://authors.elsevier.com/a/1gPMy6uaSNKFSp

Background: Premature loss of deciduous teeth is the exfoliation or extraction before physiological replacement with < 50% or < 75% of the root of the substitute tooth formed or if there is > 1 mm of alveolar bone covering the permanent successor tooth organ. This study aimed to estimate the prevalence of premature tooth loss in children and identify associated factors in a health center in Acapulco, Guerrero. Methods: We conducted a cross-sectional study in which we collected information from 109 clinical records of children examined from January 2019 to August 2021. Sociodemographic data of the children and parents were collected: socioeconomic level, non-pathological personal history, and the history of premature deciduous tooth loss. Multivariate analysis to identify factors associated with premature deciduous tooth loss was performed with CIETmap statistical software. Odds ratio (OR) and 95% confidence interval (CI) were calculated to estimate the strength of the association. Results: The prevalence of premature loss of primary teeth was 40% (43/109). The leading cause was caries (84%, 36/43). The tooth organ with the highest loss occurrence was the lower right second molar (33%, 14/43). Gender was identified as an associated factor, with males having a higher risk of loss (ORa = 2.97; CI95% = 1.33-6.65). Conclusions: Our results were similar to those reported in other studies. Strategies aimed at health promotion directed at parents and children should be reinforced.

Background The ESR1 gene suffers methylation changes in many types of cancers, including breast cancer (BC), the most frequently diagnosed cancer in women that is also present in men. Methylation at promoter A of ESR1 is the worse prognosis in terms of overall survival; thus, the early detection, prognostic, and prediction of therapy involve some methylation biomarkers. Methods Therefore, our study aimed to examine the methylation levels at the ESR1 gene in samples from Mexican BC patients and its possible association with menopausal status. Results We identified a novel 151-bp CpG island in the promoter A of the ESR1 gene. Interestingly, methylation levels at this CpG island in positive ERα tumors were approximately 50% less than negative ERα or control samples. Furthermore, methylation levels at ESR1 were associated with menopausal status. In postmenopausal patients, the methylation levels were 1.5-fold higher than in premenopausal patients. Finally, according to tumor malignancy, triple-negative cancer subtypes had higher ESR1 methylation levels than luminal/HER2+ or luminal A subtypes. Conclusions Our findings suggest that methylation at this novel CpG island might be a promising prognosis marker

During the different stages of cervical carcinogenesis there is an accumulation of epigenetic alterations leading to changes in gene expression. High-risk human papillomavirus (hrHPV) is a primary risk factor for cervical cancer (CC). Impaired proteolytic processing of histone H3 constitutes a potential epigenetic mechanism in CC. However, whether this event occurs in early stages of the HPV infection is unknown. Using human cervical samples with normal pathology but positive and negative to hrHPV, we identified that the H3 cleavage was low in the hrHPV positive cervix compared to the hrHPV negative cervix. These results suggest that low H3 processing previously observed in CC may be a primary effect of hrHPV infection.

Context: Four single-nucleotide polymorphisms (SNPs) in Mexican patients and their association with the development of breast cancer (BC). Aims: This work is focused on determining the association of fibroblast growth factor receptor (rs12196489), TOX3 (rs3803662), human telomerase reverse transcriptase (h TERT, rs10069690), and FTO (rs17817449) polymorphisms and BC in a cohort of Mexican women. Settings and design: The study included 56 patients with a confirmed diagnosis of BC and 83 controls. Clinical characteristics were obtained from medical records. Subjects and methods: Genomic DNA from the samples was obtained from lymphocytes, and the genotyping of rs12196489, rs3803662, rs10069690, and rs17817449 polymorphisms was performed by real-time polymerase chain reaction using specific TaqMan probes. Statistical analysis was assessed to evaluate the distribution of genotype frequencies between cases and controls. Statistical analysis: We used the STATA Statistical Package (version 10.1; STATA Corp., College Station, TX, USA). Student's t-test, χ2 test, or Fisher's exact test was used to evaluate the distribution of genotype frequencies. Results: No statistical differences in allelic and genotypic frequencies were found between patients with BC and controls for SNPs: rs1219648, rs3803662, and rs17817449. Interestingly, according to the χ2 test, a significant difference was exhibited for rs10069690 (odds ratio = 0.095; 95% confidence interval = 0.038-0.214; P < 0.001). Conclusions: The h TERT (rs10069690) polymorphism might be associated with BC in Mexican women. Nevertheless, additional studies in a larger cohort are required to confirm this association and to possibly use this polymorphism as a potential biomarker in the early diagnosis of BC.

Ante la ola de violencia que padece el estado de Guerrero, México, resulta importante conocer los efectos de este fenómeno en el comportamiento y rendimiento académico de los estudiantes adolescentes. Asimismo, es necesario indagar las causas en las que se manifiestan las conductas violentas más habituales, así como postular alternativas locales e institucionales que mejoren la atención escolar de esta población altamente vulnerable ante el crimen organizado. Dicho esto, el presente trabajo tiene como propósito indagar sobre los elementos constitutivos que generan acoso escolar y disrupción de los aprendizajes en los estudiantes de la Secundaria Técnica N° 185 Hermenegildo Galeana de la ciudad de Chilpancingo. Para esto, se llevó a cabo un trabajo cualitativo de tipo etnográfico con la finalidad de explicar de una manera densa y detallada las relaciones de poder entre los estudiantes, así como las condiciones en las cuales se desarrolla el proceso de enseñanza-aprendizaje. De la misma manera, nos apoyamos de cuestionarios, encuestas y entrevistas para ahondar de mejor manera el propósito de esta investigación.

El artículo sostiene que la educación intercultural emancipa a los pueblos indígenas y contribuye a la construcción de una democracia dialógica. Además, señala que la escuela juega un papel importante, puesto que promueve el respeto al Otro, fomenta saberes y aprendizajes más horizontales entre los estudiantes y docentes. Pero, también indica que la falta de presupuesto, la burocracia, la discriminación y el rechazo a la cultura no occidental impiden la construcción de una nueva escuela. Dicho esto, el propósito de este trabajo consiste en analizar la situación actual de los pueblos indígenas y la educación en el estado de Guerrero. La discusión sobre este tema permite que los actores educativos y la sociedad reconsideren el hecho de que el diálogo intercultural refuerza el sentido de pertenencia y de identidad de aquellas comunidades como los amuzgos, mixtecos, nahuas y tlapanecos, quienes se han visto en situación de marginalidad durante estos últimos decenios. En cuanto a la metodología, nos apoyamos en la sociología reflexiva e interpretativa con la finalidad de llevar a cabo un análisis minucioso de las fuentes bibliográficas y hemerográficas, pero también de las complejidades, posibilidades y paradojas del sistema educativo mexicano.

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous cell population with potent immunosuppressive functions. They play major roles in cancer and many of the pathologic conditions associated with inflammation. Long non-coding RNAs (lncRNAs) are untranslated functional RNA molecules. The lncRNAs are involved in the control of a wide variety of cellular processes and are dysregulated in different diseases. They can participate in the modulation of immune function and activity of inflammatory cells, including MDSCs. This mini review focuses on the emerging role of lncRNAs in MDSC activity. We summarize how lncRNAs modulate the generation, recruitment, and immunosuppressive functions of MDSCs and the underlying mechanisms.

Objective: Epigenetic mechanisms, such as DNA methylation, regulate important biological processes as gene expression and it was suggested that these phenomena play important roles in the carcinogenesis and tumor biology. The aim of this review is to provide the current state of knowledge about epigenetic alterations, focusing mainly on DNA methylation, reported in odontogenic tumors. Design: Literatures were searched based in the combination of the following keywords: odontogenic tumors, epigenetics, DNA methylation, histone modifications, non-coding RNA, microRNA, DNA methyltransferases. Electronic databases (Medline/PubMed, Scopus and Web of Science) were screened. Results: The analysis of epigenetic alterations in different tumors has rapidly increased; however, limited information is available about epigenetic mechanisms involved in the formation of odontogenic tumors. DNA methylation is the most studied epigenetic modification in these tumors and the participation of non-coding RNA's in odontogenic tumors has been recently addressed. Differential expression of DNA methyltransferases, altered DNA methylation patterns and aberrant expression of non-coding RNA's were reported in odontogenic tumors. Conclusions: Current studies suggest epigenetics as an emerging mechanism, possibly implicated in etiopathogenesis of odontogenic tumors. Deeper understanding of the epigenetic abnormalities in these tumors could show potential applications as biomarkers or therapeutic possibilities in the future.

Chromatin in cervical cancer (CC) undergoes chemical and structural changes that alter the expression pattern of genes. Recently, a potential mechanism, which regulates gene expression at transcriptional levels is the proteolytic clipping of histone H3. However, until now this process in CC has not been reported. Using HeLa cells as a model of CC and human samples from patients with CC, we identify that the H3 cleavage was lower in CC compared with control tissue. Additionally, the histone H3 clipping was performed by serine and aspartyl proteases in HeLa cells. These results suggest that histone H3 clipping operates as part of post-translational modification system in CC.

This paper describes simulations of two context-dependence phenomena in Pavlovian conditioning, using a neural-network model that draws on knowledge from neuroscience and makes no distinction between operant and respondent learning mechanisms. One phenomenon is context specificity or the context-shift effect, the decrease of conditioned responding (CR) when the conditioned stimulus (CS) is tested in a context different from the one in which it had been paired with the unconditioned stimulus (US). The other effect is renewal, the recovery of CR in the training context after extinction in another context. For specificity (simulation 1), two neural networks were first given 200 CS-US pairings in a context. Then, the CS was tested either in the training context or a new context. Output activations in the new context were substantially lower. For renewal (simulation 2), two networks were first given 200 CS-US pairings in a context, then 100 extinction trials in either the same context or a new one, and then tested back in the training context. Output activations during the test phase were substantially higher after extinction in a new context. The results are interpreted in terms of the dynamics of activations and weights.