Gastrointestinal Parasitosis and Anemia Monitoring in the Child Population of Villa Clarín, Colombia

BackgroundThere is limited non-anecdotal literature on the effectiveness of health policies and the prevalence of childhood anemia in rural communities in the Colombian Caribbean region. The objective of the following study is to report a parasitological and hematological episode of 94 children belonging to the child population of Villa Clarín, Colombia, and reinforce the disposable literature of local care reports.Case presentationThis article studies an event of intestinal parasitosis prevalence and anemia in 94 children between 1 and 11 years of age, grouped into three age ranges of 1 to 3 years, 4 to 6 years, and 7 to 11 years of age respectively, from the rural community of Villa Clarín, Colombia. Blood samples were obtained by venipuncture and processed through a complete blood count. The feces were collected by spontaneous evacuation and analyzed using a spontaneous sedimentation technique. The prevalence of intestinal parasitosis was 96.81%. ConclusionsEight of the 91 children in whom intestinal parasites were detected had anemia while 29 were above the normal levels of hemoglobin. An association was found with E. histolytica / dispar, but not with A. lumbricoides, T. trichiura, S. stercolaris, Uncinaria, Taenia sp, H. nana, H. diminuta, G. lamblia, T. hominis or B. hominis. The high prevalence of intestinal parasitosis and the anemia levels indicate deficiencies in environmental sanitation and hygienic-sanitary measures.

Simulation of receptor triggering by kinetic segregation shows role of oligomers and close-contacts

The activation of T cells, key players of the immune system, involves local evacuation of phosphatase CD45 from a region of the T cell's surface, segregating it from the T cell receptor. What drives this evacuation? In the presence of antigen, what ensures evacuation happens in the sub-second timescales necessary to initiate signaling? In the absence of antigen, what mechanisms ensure evacuation does not happen spontaneously, which could cause signaling errors? Phenomena known to influence spatial organization of CD45 or similar surface molecules include diffusive motion in the lipid bilayer, oligomerization reactions, and mechanical compression against a nearby surface, such as that of the cell presenting antigen. Computer simulations can investigate hypothesized spatiotemporal mechanisms of T cell signaling. The challenge to computational studies of evacuation is that the base process, spontaneous evacuation by simple diffusion, is in the extreme rare event limit, meaning direct stochastic simulation is unfeasible. Here we combine particle-based spatial stochastic simulation with the Weighted Ensemble method for rare events to compute the mean first-passage time for cell surface availability by surface reorganization of CD45. We confirm mathematical estimates that, at physiological concentrations, spontaneous evacuation is extremely rare, roughly 300 years. We find that dimerization decreases the time required for evacuation. A weak bi-molecular interaction (dissociation constant estimate 460 microMolar) is sufficient for an order of magnitude reduction of spontaneous evacuation times, and oligomerization to hexamers reduces times to below 1 second. This introduces a mechanism whereby CD45 oligomerization could be accessible to an engineered therapeutic. For large regions of close-contact, such as those induced by large microvilli, molecular size and compressibility imply a nonzero re-entry probability 60 %, decreasing evacuation times. Simulations show that these reduced evacuation times are still unrealistically long, suggesting that a yet-to-be-described mechanism, besides compressional exclusion at a close contact, drives evacuation.