Reduction of NrF2 as coadjuvant during the development of persistent periapical lesions

Background: Persistent periapical lesions (PPL) are the result of pulpar necrosis induced by bacterial infection resulting in bone degradation and culminating with the loss of dental piece. Pathological changes in the peripapice are associated with the presence of free radicals. The transcription factor Nrf2 is the main regulator of the endogenous antioxidant response against oxidative stress and has been implicated in the regulation of osteoclastogenesis.The aim is to determine the oxidative condition in samples from patients with Persistent Periapical Injuries as a detonating factor of tissue damage. Material and methods: An observational, descriptive, cross-sectional study was carried out in samples with PPL (cases) and samples by removal of third molars (controls) obtained in the clinic of the specialty in endodontics, University of Guadalajara. Samples were submitted to histological staining with Hematoxylin-Eosin, lipoperoxide analysis, Superoxide Dismutase (SOD), Glutathione-Peroxidase (GPx) and Catalase (CAT) activities were determined by immunoenzymatic assays and NrF2 by Western Blot analysis. Results: Samples from PPL patients histologically showed an increased presence of lymphocytes, plasma cells, and eosinophils, as well as a decrease in extracellular matrix proteins and fibroblast cells. There was a rise in lipid peroxidation, GPx and SOD activities, but an important decline (36%) in Catalase activity was observed (p<0.005); finally, NrF2-protein was diminished at 10.41%. All comparisons were between cases vs controls. Conclusions: The alterations in antioxidants endogenous NrF2-controlled are related to osseous destruction in patients with PPL. (AU)

Demographic and climatic factors associated with dengue prevalence in a hyperendemic zone in Mexico: an empirical approach.

BACKGROUND: Many models for predicting dengue epidemics use incidence and short-term changes in climate variables, however, studies in real-life scenarios for correlations of seroprevalence (SP) with long-term climate variables and with integration of socio-economic factors are scarce. Our objective was to analyse the combined correlation between socio-economic and climate variables with the SP of dengue in Mexico. METHODS: We performed a seroepidemiological ecological study on the Mexican Pacific coast. Dengue SP was estimated by the presence of immunoglobulin G antibodies in 1278 inhabitants. We implemented multiple correlations with socio-economic, climatic and topographic characteristics using logistic regression, generalized linear models and non-linear regressions. RESULTS: Dengue SP was 58%. The age-adjusted correlation was positive with the male sex, while a negative correlation was seen with socio-economic status (SES) and scholl level (SL). The annual temperature showed a positive correlation, while the altitude was negative. It should be noted that these correlations showed a marked 'S' shape in the non-linear model, suggesting three clearly defined scenarios for dengue risk. CONCLUSION: Low SES and SL showed an unexpected paradoxical protective effect. Altitude above sea level and annual temperature are the main determinants for dengue in the long term. The identification of three clearly delineated scenarios for transmission could improve the accuracy of predictive models.

Presence of Acute Chagas Disease Among Febrile Patients in the Western Coast of Mexico.

Chagas disease (ChD) is a parasitosis caused by the protozoan Trypanosoma cruzi (Tc). It is endemic to almost all Latin American countries, including the southern United States. The acute form of ChD and its actual incidence have rarely been described in Mexico, despite the extensive presence of favorable niches for its transmission. The objective of this study was to estimate the frequency of acute ChD in febrile patients at the central Pacific coast of Mexico. For this, we surveyed patients with persistent fever (5 to 10 days) in five hospitals at the Mexican states of Jalisco, Colima, and Nayarit in 2012. Samples were taken from a total of 485 patients to detect Tc in blood using the polymerase chain reaction (PCR) test and direct microscopic examination. Of these subjects, 10 were positive for PCR and none for microscopic examination (2% in 12 months). We adjusted this rate by the total people at risk in the area and obtained an incidence of 7.4/100,000 habs./year. The positive cases showed no association with sex, rural settlement, or pet ownership, only with the contact with Triatominae insects (odds ratio = 9.22 and confidence interval: 1.93-44.06). The clinical picture of positive patients showed an association with the diagnosis of lower respiratory tract infections. Meanwhile, only one fatal case showed the typical picture of acute fatal cardiomyopathy. The pulmonary manifestations of our patients suggest possible lung pathogenicity of Tc, which merits further investigation. Our findings differ markedly from the official reports for ChD. This difference suggests an underestimation of the disease. These findings urge the Mexican health authorities to implement more vigorous actions aimed at improving medical skills in the timely diagnosis of ChD, as well as to apply efficient preventive programs.