Inclusión de un canino por la presencia de un supernumerario y un odontoma complejo / Impaction of a canine due to the presence of a supernumerary tooth and a complex odontoma

La retención dentaria se define como la detención total o parcial de la erupción de un diente dentro del intervalo de tiempo esperado en relación con la edad del paciente. Incluye tanto los dientes en proceso de erupción como los impactados. La segunda retención más frecuente es la de los caninos, tras los terceros molares inferiores, se localizan en un 85% en el maxilar, un 15%en mandíbula y es más frecuente en el sexo femenino. El diagnóstico de los dientes retenidos, delos dientes supernumerarios y de los tumores odontogénicos, es radiológico, suele realizarse de forma casual en controles rutinarios, o como prueba complementaria ante alteraciones de la erupción, alteraciones intraorales o signos y síntomas de inclusión dentaria. Se presenta un caso clínico con una inclusión del 33 asociado a un supernumerario ya un odontoma. Paciente varón de trece (..) (AU)

Tooth retention is defined as the total or partial stoppage of the eruption of a tooth within the interval of time expected in relation to the patient's age. It includes the teeth in the process of eruption as well as the impacted teeth. The second most frequent retention is that of the canines, following the lower third molars, 85% of which are located in the maxilla, 15% in the mandible and they are more frequent in females. The diagnosis of tooth retention, of supernumerary teeth and of the odontogenic tumours is radiological, usually found by chance in routine checkups, or as a complementary test in the event of disorders in the eruption, intraoral alterations or signs or symptoms of dental impaction. A clinical case is presented with the impaction of the 33 associated to a supernumerary tooth and to an odontoma. Male patient of (..) (AU)

Distracción alveolar para la colocación de implantes. Revisión de la literatura / No disponible

Introducción: La distracción alveolar es un procedimiento en el cual el hueso alveolar y la mucosa subyacente son regenerados. Los bajos porcentajes de predictibilidad en regeneración vertical y horizontal de otras técnicas ha incrementado el interés acerca de esta técnica para aumentar el volumen óseo para la posterior colocación de implantes. Material y métodos: Se realizó una revisión bibliográfica de la literatura científica publicada. Se seleccionaron 31 artículos y se descartaron 14 por no ceñirse a nuestros criterios de inclusión estudios con un seguimiento mayor a un año en inglés publicado entre los años 1996-2011.Resultados: La literatura aporta un aumento de volumen óseo medio desde 3 a 15 mm. con un porcentaje de supervivencia de los implantes colocados sobre hueso distraído de un 97%. Estudios publicados muestran una gran cantidad de complicaciones atribuidas a la falta de conocimiento de esta técnica. Conclusiones: El porcentaje de éxito de los implantes colocados en hueso distraído es similar al obtenido en hueso nativo. De las técnicas de aumento óseo es la técnica mediante la cual se ha obtenido una mayor ganancia, sin embargo no es una técnica exenta de complicaciones. Se necesitan una mayor cantidad de estudios controlados a largo plazo para evaluar diferentes parámetros como: reabsorción ósea post-distracción, factores estéticos relacionados con el tejido blando y con la restauración protésica fina (AU)

Introduction: Alveolar distraction is a procedure for the regeneration of alveolar bone and the underlying mucous membrane. Low predictability rates for vertical and horizontal regeneration in other techniques has increased interest in this technique in order in crease bone volume prior to placing implants. Material and methods: A bibliographical review of the published scientific literature was carried out. 31 articles were selected and 14 were discarded as they did not meet our criteria for inclusion as studies with at least one years follow up published in English from 1996-2011.Results: The literature reports average increased bone volume from 3 to 15mm with a survival rate for implants inserted into distracted bone of 97%. The published studies demonstrate a large number of complications attributed to a lack of understanding of this technique. Conclusions: The success rate for implants inserted in distracted bone is similar to that obtained in native bone. Of all the techniques for increasing bone volume it is the one that has obtained the largest increases, however it is not a technique free from complications. More long-term controlled studies are required to assess different parameters, such as: post-distraction bone reabsorption, aesthetic factors relating to soft tissue and the final prosthetic restoration (AU)

Periodicity and patterns of Entamoeba histolytica and E. dispar infection in HIV+/AIDS patients in Mexico.

In a 12-month longitudinal study, a cohort of Mexican HIV+/AIDS patients was checked several times for Entamoeba infection, with the parasites identified, as E. histolytica or E. dispar, using PCR. The polymorphic region of the parasites' chitinase genes was investigated by PCR, with the variation in amplicon sizes being used as a measure of the genetic variation among the isolates. The patients found infected with Entamoeba at the start of the study displayed varied patterns of infection clearance and re-infection. The analysis of the polymorphisms in the chitinase gene revealed seven polymorphic patterns in the E. histolytica isolates investigated and three in the E. dispar isolates. Many of the patients were each re-infected with Entamoeba at least once during the 12 months of follow-up. As seen in a previous study in Mexico, none of the E. histolytica-infected patients developed any clinical symptoms of invasive amoebiasis during the follow-up period. The results highlight the complexity of the host-parasite relationship in human amoebiasis.

The association of intestinal parasitosis and H. pylori infection in children and adults from a Mexican community with high prevalence of parasitosis.

BACKGROUND: Experimental evidences have suggested that a Th1 response is unable to eliminate H. pylori colonization; whereas a Th2 response, like the one induced by vaccination, reduces H. pylori infection in animal models. Some parasitic infections induce a polarized Th2 response, which theoretically would favor a reduced H. pylori prevalence. The aim of this work was to study the possible association between parasitic infections and H. pylori prevalence. MATERIALS AND METHODS: The study population included 120 children and 188 adults from a low socioeconomic level village. H. pylori prevalence was determined in serum by ELISA; parasitic infections were identified in feces by microscopic examination; and total serum IgE levels, as an indirect indicator of some parasitic infections, were determined by ELISA. RESULTS: In children, H. pylori prevalence was no different between those with and without intestinal parasitic infection. By contrast, adults with intestinal parasitic infection had a significantly lower H. pylori prevalence than adults without parasites (62.6% compared with 80.4%; p = 0.006, OR 2.45). Also in adults, but not in children, total IgE levels were significantly higher in those without H. pylori infection than in those with H. pylori infection (p < 0.001). CONCLUSIONS: Intestinal parasitic infections and serum IgE levels showed an age-dependent association with H. pylori prevalence. In adults, but not in children, intestinal parasitic infections and increased IgE levels where associated with a reduced H. pylori prevalence.

Persistence of secretory antiamoebic antibodies in patients with past invasive intestinal or hepatic amoebiasis.

In the present work, it was demonstrated that in amoebic dysentery and amoebic liver abscess patients, the secretory response is long-lasting (> 12 months); and 50% of amoebic dysentery patients developed circulating antiamoebic IgG in comparison with 100% of amoebic liver abscess individuals. A total of 83% of these individuals developed high levels of serum anti-Entamoeba histolytica IgA. However, only 10.4% of the dysentery patients showed this anti-E. histolytica antibody isotype in serum. There was no correlation between secretory and serum antiamoebic response, suggesting independent inductive and effector sites in both compartments.

The effect of formalin fixation on the polymerase chain reaction characterization of Entamoeba histolytica.

Formalin fixation is the most common storage, transportation and preservation method for stool samples. However, fixation dramatically reduces our ability to extract from stool samples DNA that is a suitable template for polymerase chain reaction (PCR)-based diagnostic tests. In this study we evaluated the effects of formalin concentration and of the time stored in fixative on the success of PCR amplification. We found that the deleterious effects of formalin are both time and concentration dependent and may result from fragmentation of fixed DNA during its purification.

HLA characterization in adult asymptomatic cyst passers of Entamoeba histolytica/E. dispar.

The present work aimed at studying the possible association of HLA antigens with Entamoeba histolytica/E. dispar asymptomatic infection in a Mexican mestizo population. A case-control design was selected for evaluation of the role of genetic markers in parasite infection. For this purpose the HLA-A, HLA-B, and HLA-DR profiles of a population of asymptomatic E. histolytica/E. dispar adult cyst passers (cases) and a corresponding nonparasitized adult group (controls) followed for 12 months were identified. Entamoeba species were identified through zymodeme patterns and/or amplification of species-specific DNA sequences. A healthy, nonparasitized group of individuals was included as a control. Our results show that apparently, no specific HLA marker is associated with the asymptomatic cyst passers' condition. These findings have to be added to previous results in which, in contrast to a demonstrated association between HLA-DR3 and amebic liver abscess in Mexican mestizo adults and infants, no significant association with amebic rectocolitis was found.

Prospective study of Entamoeba dispar infection in a cohort of mothers and their infants: relationship to serum antibody response.

The sera of cohorts of newborn infants and their mothers, characterized as cyst passers of Entamoeba with nonpathogenic zymodemes (E. dispar) and seropositive for amoebic antigens, were analyzed. Both cohorts were followed for a period of 12 months by microscopic examination of feces and determination of serum anti-amoebic antibody titers using the indirect hemagglutination assay. Control groups (noncyst passer mothers and their infants) were included and followed. To characterize antigens involved in the induction of IgG and IgA antibody responses, Western blots of serum from all participants were tested and immunoplots of the frequency of antigenic recognition were constructed. Results of clinical follow-up and microscopic examination of feces showed that during the 12-month period none of the cyst passer mothers had episodes of diarrhea attributable to E. histolytica invasion; five of 21 children of cyst passer mothers became infected during the study, five of five infected children developed serum antiamebic antibodies (titers 1:64-1:128); none of the cohort of children from cyst passer mothers had diarrhea due to E. histolytica. Western blot analysis showed that there are antigenic fractions that induce serum antibodies of the IgG and IgA classes against E. dispar very early in the host-parasite relationship. Our results suggest that mechanisms of antibody induction different from intestinal invasion may be operating in amebic infection. Intestinal absorption of antigen, systemic reflection of secretory antibody response, and priming of newborns by maternal anti-idiotypic antibody transfer are discussed.

Human cell-mediated immune responses to antigenic fractions of Salmonella typhi.

The proliferative responses of peripheral blood mononuclear cells of 10 subjects that had typhoid fever, and healthy volunteers without history of typhoid fever or immunization against disease, were analysed with antigen fractions from two protein extracts of Salmonella typhi. Fractions from each extract were separated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) electrophoresis, transferred to nitrocellulose filters by electroblotting and processed to obtain antigen-bearing nitrocellulose particles for use in lymphocyte cultures. Although the individual proliferative responses were heterogeneous we identified two main immunogenic regions of 29-32 10(3) MW and 45-56 x 10(3) MW for both extracts. Even though there was no one particular antigenic fraction capable of stimulating lymphocytes from all individuals with a previous history of typhoid fever, the combination of three fractions 29-32, 41-45, 63-71 x 10(3) MW could be stimulatory for cells of 90% of these individuals. Also, four subjects that did not respond to unfractionated antigens gave proliferative responses to several fractions of the same extract. We have identified the main immunogenic fractions of S. typhi that might play a role during typhoid infection and postinfection immunity, and merit further purification and characterization.

Cellular immune response to fractionated avian antigens by peripheral blood mononuclear cells from patients with pigeon breeder's disease.

Pigeon breeder's disease (PBD), a form of hypersensitivity pneumonitis caused by repeated inhalation of antigens of pigeon origin, is characterized by a diffuse inflammation of the lower respiratory tract. Although a variety of immunologic and nonimmunologic mechanisms have been described in the development of the disease, the pathogenesis is still far from clear. In this study we analyzed the T-lymphocyte proliferative response to a variety of avian antigens with use of peripheral blood mononuclear cells from 11 patients who had PBD and 10 healthy volunteers. We used a new method based on avian antigen-bearing nitrocellulose particles derived from Western blots to study the T-cell proliferative response to 15 antigenic fractions obtained from pigeon serum. With this technique, complex mixtures of antigens can be fractionated by polyacrylamide gel electrophoresis, transferred to nitrocellulose membranes, and used for T-cell proliferation assays with selected antigenic determinants. A wide variety of responses were observed, and there were no reproducible patterns of reaction within either group. Nine of 10 healthy subjects responded to some soluble fractions. However, patients with PBD displayed the strongest response and responded to a significantly greater number of antigenic fractions. Fraction 2, representing a 220 kd molecular weight protein, was the only immunodominant antigen when both groups were compared; it was recognized by 73% of the patients with PBD and by only 20% of control subjects (p < 0.03). These findings show that T lymphocytes of patients with PBD recognize a wide range of bird proteins, which induce marked T-cell proliferation.