Seguimiento clínico y serológico de pacientes tratados de leishmaniosis cutánea

La inmunofluorescencia indirecta con antígeno crudo de Leishmania constituye una técnica serológica convencional que para el diagnóstico de leishmaniosis presenta una sensibilidad moderada, entre el 70 y el 80%. Son muy raros los trabajos que en la literatura reportan su uso para el seguimiento serológico post-tratamiento de los pacientes, aunque la experiencia que en general se tiene en áreas endémicas consiste en que la mayoría de los casos clínicamente curados presentan una disminución importante de los títulos serológicos con el avance del tiempo. Estetrabajo tiene por objetivo describir el cuadro clínico y los valores de la reacción serológica en pacientes con leishmaniosis cutánea antes y después de su tratamiento. Para este trabajo ha sido estudiado el comportamiento clínico y serológico de un grupo de 32 pacientes con leishmaniosis cutánea, en un brote de la enfermedad producido en 1998 en el distrito de Capiibary, Departamento de San Pedro. De los pacientes evaluados hasta 18 o 24 meses post-tratamiento todos excepto uno manifestaron curación de sus lesiones. La gran mayoría de los sujetos han mostrado disminución de los títulos serológicos, hasta la negativización. Se concluye que el seguimiento serológico arroja valores que coinciden con la clínica de los pacientes, por lo tanto amerita que sea llevado a cabo complementariamente con la inspección clínica. Al no contar en este estudio con casos de reactivación cutánea o mucosa, no se puede concluir acerca del valor predictivo de la serología para estos casos

Leishmaniasis tegumentaria: sensibilidad de la inmunofluorescencia indirecta en pacientes con diagnóstico parasitológico

La leishmaniasis tegumentaria es una zoonosis endémica de zonas tropicales y subtropicales del mundo, de difícil diagnóstico laboratorial. En áreas endémicas se realiza el diagnóstico de presunción basado en la presentación clínica y la reactividad a la prueba cutánea de la leishmanina. Sin embargo, un diagnóstico definitivo de la enfermedad requiere la combinación de diferentes métodos, entre los cuales la inmunofluorescencia indirecta (IFI) es uno de los más utilizados. Para determinar la sensibilidad de la IFI, se sometió un total de 95 pacientes con lesiones comprobadas de leishmaniasis a las pruebas de leishmanina, biopsia histopatológica, cultivo e IFI. En 80 pacientes se logró el diagnóstico parasitológico a través de la histopatología y/oel cultivo. De ellos, 58 muestras (72,5 %) dieron reacción positiva en la IFI para Leishmania, aunque 12 de ellas (21%) también mostraron serología positiva para enfermedad de Chagas. La sensibilidad de la IFI para los casos de leishmaniasis mucosa solamente fue 81,3 % (n=16). Se concluye que la IFI es un método de moderada sensibilidad para el diagnóstico de leishmaniasis tegumentaria

Population genetics of wild-type CAG repeats in the Machado-Joseph disease gene in Portugal

To gain insights on the molecular mechanisms of mutation that led to the emergence of expanded alleles in the MJD gene, by studying the behavior of wild-type alleles and testing the association of its distribution with the representation of the disease. Methods: The number of CAG motifs in the MJD gene was determined in a representative sample of 1000 unrelated individuals. Associations between the repeat size and the epidemiological representation of MJD were tested. Results: The allelic profi le of the total sample was in the normal range (13–41 repeats), with mode (CAG) 23 . No intermediate alleles were present. Allelic size distribution showed a negative skew. The correlation between the epidemiological representation of MJD in each district and the frequency of small, medium and large normal alleles was not signifi cant. Further correlations performed grouping the districts also failed to produce signifi cant results. Conclusions: The absence of association between the size of the repeats and the representation of MJD demonstrates that prevalence is not an indirect refl ection of the frequency of large normal alleles. Globally the results obtained are in accordance with a model that postulates the occurrence of a few mutations on the basis of most of the MJD cases worldwide

Ecological Modeling of Aedes aegypti (L.) Pupal Production in Rural Kamphaeng Phet, Thailand

Background - Aedes aegypti (L.) is the primary vector of dengue, the most important arboviral infection globally. Until an effective vaccine is licensed and rigorously administered, Ae. aegypti control remains the principal tool in preventing and curtailing dengue transmission. Accurate predictions of vector populations are required to assess control methods and develop effective population reduction strategies. Ae. aegypti develops primarily in artificial water holding containers. Release recapture studies indicate that most adult Ae. aegypti do not disperse over long distances. We expect, therefore, that containers in an area of high development site density are more likely to be oviposition sites and to be more frequently used as oviposition sites than containers that are relatively isolated from other development sites. After accounting for individual container characteristics, containers more frequently used as oviposition sites are likely to produce adult mosquitoes consistently and at a higher rate. To this point, most studies of Ae. aegypti populations ignore the spatial density of larval development sites. Methodology - Pupal surveys were carried out from 2004 to 2007 in rural Kamphaeng Phet, Thailand. In total, 84,840 samples of water holding containers were used to estimate model parameters. Regression modeling was used to assess the effect of larval development site density, access to piped water, and seasonal variation on container productivity. A varying-coefficients model was employed to account for the large differences in productivity between container types. A two-part modeling structure, called a hurdle model, accounts for the large number of zeroes and overdispersion present in pupal population counts. Findings - The number of suitable larval development sites and their density in the environment were the primary determinants of the distribution and abundance of Ae. aegypti pupae. The productivity of most container types increased significantly as habitat density increased. An ecological approach, accounting for development site density, is appropriate for predicting Ae. aegypti population levels and developing efficient vector control program

T-Cell Memory Responses Elicited by Yellow Fever Vaccine are Targeted to Overlapping Epitopes Containing Multiple HLA-I and -II Binding Motifs

The yellow fever vaccines (YF-17D-204 and 17DD) are considered to be among the safest vaccines and the presence of neutralizing antibodies is correlated with protection, although other immune effector mechanisms are known to be involved. T-cell responses are known to play an important role modulating antibody production and the killing of infected cells. However, little is known about the repertoire of T-cell responses elicited by the YF-17DD vaccine in humans. In this report, a library of 653 partially overlapping 15-mer peptides covering the envelope (Env) and nonstructural (NS) proteins 1 to 5 of the vaccine was utilized to perform a comprehensive analysis of the virus-specific CD4+ and CD8+ T-cell responses. The T-cell responses were screened ex-vivo by IFN-γ ELISPOT assays using blood samples from 220 YF-17DD vaccinees collected two months to four years after immunization. Each peptide was tested in 75 to 208 separate individuals of the cohort. The screening identified sixteen immunodominant antigens that elicited activation of circulating memory T-cells in 10% to 33% of the individuals. Biochemical in-vitro binding assays and immunogenetic and immunogenicity studies indicated that each of the sixteen immunogenic 15-mer peptides contained two or more partially overlapping epitopes that could bind with high affinity to molecules of different HLAs. The prevalence of the immunogenicity of a peptide in the cohort was correlated with the diversity of HLA-II alleles that they could bind. These findings suggest that overlapping of HLA binding motifs within a peptide enhances its T-cell immunogenicity and the prevalence of the response in the population. In summary, the results suggests that in addition to factors of the innate immunity, "promiscuous" T-cell antigens might contribute to the high efficacy of the yellow fever vaccines. © 2013 de Melo et al

Limits on WWZ and WW\gamma couplings from p\bar{p}\to e\nu jj X events at \sqrt{s} = 1.8 TeV

We present limits on anomalous WWZ and WW-gamma couplings from a search for WW and WZ production in p-bar p collisions at sqrt(s)=1.8 TeV. We use p-bar p -> e-nu jjX events recorded with the D0 detector at the Fermilab Tevatron Collider during the 1992-1995 run. The data sample corresponds to an integrated luminosity of 96.0+-5.1 pb^(-1). Assuming identical WWZ and WW-gamma coupling parameters, the 95% CL limits on the CP-conserving couplings are -0.33<lambda<0.36 (Delta-kappa=0) and -0.43<Delta-kappa<0.59 (lambda=0), for a form factor scale Lambda = 2.0 TeV. Limits based on other assumptions are also presented.Comment: 11 pages, 2 figures, 2 table