Prevalencia de caries temprana de la infancia en niños con enfermedades respiratorias crónicas / Prevalence of early childhood caries in children with chronic respiratory diseases

Introducción: Se ha estipulado que los niños con condiciones crónicas de salud, pueden tener un alto riesgo de caries. Aunque la literatura sobre caries tempranas de la infancia (CTI) es extensa, poco se sabe acerca de su prevalencia en niños con estas condiciones. Objetivo: Conocer la prevalencia de CTI en niños con enfermedades respiratorias crónicas (ERC) en el Hospital Calvo Mackenna, Santiago, Chile y determinar su asociación con CTI. Pacientes y Método: Se realizó un estudio de corte transversal, sobre un total de 120 niños de 2 a 5 años 11 meses de edad, un grupo de estudio de 60 niños con ERC y un grupo control de 60 niños sanos fueron analizados. Se diagnosticó CTI de acuerdo a la definición aceptada por la AAPD, mediante un examen oral realizado por un operador bajo condiciones estandarizadas. Para el análisis estadístico se utilizó el programa Stata 11. Resultados: La prevalencia de CTI fue de 53 por ciento en niños con ERC y 25 por ciento en niños sanos (p < 0,0001). El valor de Qdds Ratio para niños con ERC fue de 7,046 mostrando un incremento del riesgo de CTI, comparado con niños sanos. (95 por ciento CI: 2,372-20,929). Conclusión: En esta población, los niños con ERC presentan una alta prevalencia de CTI. En esta muestra se encontró una asociación estadísticamente significativa entre CTI y ERC.

Introduction: Children with chronic health conditions may have an increased risk for developing caries. Although the literature on early childhood cavities (ECC) is extensive, little is known about its prevalence in children with these conditions. objective: To determine the prevalence of ECC in children with chronic respiratory disease (CRD) at Luis Calvo Mackenna Hospital in Santiago, Chile, and to determine their association. Patients and Methods: A cross-sectional study was performed on 120 children aged 2 to 5 years 11 months, a study group of 60 children with CRD and a control group of 60 healthy children were analyzed. ECC was diagnosed meeting the ALAPD criteria, an oral exam conducted by an operator under standardized conditions. The Stata 11 program was used for statistical analysis. results: The prevalence of ECC was 53 percent in children with CRD and 25 percent in healthy children (p < 0.0001). The value of odds ratio for children with CRD was 7.046 showing an increased risk of ECC compared with healthy children. (95 percent CI: 2.372 to 20.929). Conclusion: In this population, children with CRD have a high prevalence of ECC. In this sample, a statistically significant association between ECC and CRD was found.

Trypanosoma cruzi and human ubiquitin are immunologically distinct proteins despite only three amino acid difference in their primary sequence.

The high similarity between Trypanosoma cruzi and human ubiquitin prompted us to characterize the human humoral immunity to host and parasite ubiquitin in Chagas disease and its possible role in Chagas autoimmunity. We have used a simplified one step purification procedure to partially purify T. cruzi ubiquitin. Using this preparation we have performed ELISA and Western blots, to show that chagasic sera recognise T. cruzi but not human or Leishmania ubiquitin indicating a species-specific response. Our results show that despite the high degree of similarity in the primary structure of human and T. cruzi ubiquitins, the three amino acid difference is sufficient to distinguish parasite versus host proteins.

Presence of an unusually high concentration of an ubiquitinated histone-like protein in Trypanosoma cruzi.

The conjugation of ubiquitin to histones H2A and H2B has been established in higher eukaryotes and has been related to changes in chromatin organization. In Trypanosoma cruzi, no condensation of chromatin occurs during mitosis. In order to determine the presence of histone ubiquitination in T. cruzi epimastigotes, histones were extracted from chromatin and analyzed by three electrophoretic systems: acid-urea, triton-acid-urea and sodium-dodecyl-sulphate polyacrylamide gel. The immunochemical detection of ubiquitin-histone conjugates by Western blotting showed a strong reaction with a slow migrating band of M(r) 19 kDa. The high percentage of ubiquitin-histone conjugates present in T. cruzi chromatin may be related to the inability of this parasite to condense chromatin into a 30 nm fiber.

Mechanisms of protein degradation in Trypanosoma cruzi.

Proteolysis of endogenous proteins may play a key role in the adaptation of T. cruzi to the different host environments to which it is exposed during its complex life cycle. For this reason, we have attempted to study the intracellular pathways of protein degradation in the non infective epimastigotes form (EP strain) of T. cruzi. Following intracellular proteolysis by pulse chase experiments with 35 S methionine, we observed a significant inhibition (50%) of the degradation of endogenous proteins in log phase parasites in the presence of inhibitors of lysosomal functions, such as chloroquine and E 64. A significant increase in proteolysis was observed in stationary phase parasites which was reverted to log phase values by supplementing the chase medium with 0.5% glucose or 10% serum, or in the presence of chloroquine. Under this condition of nutritional stress, we could observe an increase in the activity of acid proteases. A significant increase in the degradation rates was observed when abnormal proteins were induced in the parasite by amino acid analogs and puromycin. This increase was not affected by E 64, suggesting the participation of non lysosomal mechanisms in the degradation of rapidly degradable abnormal proteins. Under these conditions, we could observe an increase in high molecular weight conjugates of ubiquitin with respect to endogenous proteins. These results suggest the importance of lysosomal mechanisms in the degradation of cellular proteins in nutritional optimal conditions and during nutritional deprivation, and the possible involvement of the ubiquitin system in the degradation of high turnover proteins.

Changes in proteolytic activity during the growth of Trypanosoma cruzi epimastigotes.

The proteolytic pattern of Trypanosoma cruzi epimastigotes was studied using electrophoresis in gelatin containing SDS polyacrylamide gels. Under conditions that represent a nutritional stress such as the depletion of glucose in an axenic medium the results obtained showed a significant increase in the activity of two proteases of M(r) = 50,000 and M(r) = 60,000 as well as the appearance of higher molecular weight bands during the transition from log to stationary phase parasites. The use of different protease inhibitors strongly suggests that all these proteases are of the cysteine type, and their acid pH optimal would be in agreement with the possible localization in the parasite lysosomes. The reincubation of stationary phase parasites in fresh LIT medium or the addition of 0.4% glucose partially reverted the proteolytic pattern to that observed in log phase parasites. The regulation in the activity of these enzymes could be related to the well established use of amino acids for catabolic purpose after depletion of the medium glucose.