Oral Immunization With a Plant HSP90-SAG1 Fusion Protein Produced in Tobacco Elicits Strong Immune Responses and Reduces Cyst Number and Clinical Signs of Toxoplasmosis in Mice.

Plant 90kDa heat shock protein (HSP90) is a potent adjuvant that increases both humoral and cellular immune responses to diverse proteins and peptides. In this study, we explored whether Arabidopsis thaliana HSP90 (AtHsp81.2) can improve the immune effects of a Toxoplasma gondii surface antigen 1 (SAG1). We designed two constructs containing the sequence of mature antigen (SAG1m), from aa77 to aa322, and B- and T-cell antigenic epitope-containing SAG1HC, from aa221 to aa319 fused to AtHsp81.2 sequence. When comparing the transient expression in Nicotiana tabacum X-27-8 leaves, which overexpress the suppressor helper component protease HC-Pro-tobacco etch virus (TEV), to that in N. benthamiana leaves, co-agroinfiltrated with the suppressor p19, optimal conditions included 6-week-old N. benthamiana plants, 7-day time to harvest, Agrobacterium tumefaciens cultures with an OD600nm of 0.6 for binary vectors and LED lights. While AtHsp81.2-SAG1m fusion protein was undetectable by Western blot in any of the evaluated conditions, AtHsp81.2-SAG1HC was expressed as intact fusion protein, yielding up to 90µg/g of fresh weight. Besides, the AtHsp81.2-SAG1HC mRNA was strongly expressed compared to the endogenous Nicotiana tabacum elongation factor-alpha (NtEFα) gene, whereas the AtHsp81.2-SAG1m mRNA was almost undetectable. Finally, mice were orally immunized with AtHsp81.2-SAG1HC-infiltrated fresh leaves (plAtHsp81.2-SAG1HC group), recombinant AtHsp81.2-SAG1HC purified from infiltrated leaves (rAtHsp81.2-SAG1HC group), non-infiltrated fresh leaves (control group), or phosphate-buffered saline (PBS group). Serum samples from plAtHsp81.2-SAG1HC-immunized mice had significantly higher levels of IgGt, IgG2a, and IgG2b anti-SAG1HC antibodies than serum from rAtHsp81.2-SAG1HC, control, and PBS groups. The number of cysts per brain in the plAtHsp81.2-SAG1HC-immunized mice was significantly reduced, and the parasite load in brain tissue was also lower in this group compared with the remaining groups. In an immunoblot assay, plant-expressed AtHsp81.2-SAG1HC was shown to react with antibodies present in sera from T. gondii-infected people. Therefore, the plant expression of a T. gondii antigen fused to the non-pathogenic adjuvant and carrier plant HSP90 as formulations against T. gondii can improve the vaccine efficacy, and plant extract can be directly used for vaccination without the need to purify the protein, making this platform a suitable and powerful biotechnological system for immunogenic antigen expression against toxoplasmosis.

Tomografía axial computerizada helicoidal en el estudio de la urolitiasis (pieloTAC): experiencia en un centro de diagnóstico por imágenes: Antofagasta / Tomography axial computed helical in the study of urolithiasis (pieloTAC): experience in the centro de diagnóstico por imágenes: Antofagasta

In Chile, the urolithiasis constitutes a frequent pathology, reaching a 10% prevalence, existing diverse imaging methods for their, diagnosis among them the Helical Tomography Wilhout Contrast (Pielo T AC) contitutes the gold standard, by their high sensitivy (> 95%) and specificity (> 85%). By means of retrospective descriptive study, one analized 82 cases with information of PieloTAC, realised by clinical suspicion of urolithiasis, between October 2006 and March 2007 in the Centro de Diagnóstico por Imágenes Diagnoimage, Antofagasta. In 56.10% of the cases urolithiasis was confirmed, with predominance of renal location in 57.63%. A 30.56% of patients without lithiasis, presented pelvic phlebolit, renal cyst and calcium granuloma. One concludes that in this PieloTAC series it provides a highly sensitive imaging diagnosis and specificity for urolithiasis, reporting so large, location and composition of calculi, like also diagnoses differentials with other pathologies, showing as advantages the short run time, non contrasts use and to be independent operador.

En Chile, la nefrourolitiasis constituye una patología frecuente, alcanzando una prevalencia de 10%, existiendo diversos métodos imagenológicos para su diagnóstico, entre ellos la Tomografía Helicoidal Sin Contraste (PieloTAC) constituye el examen imagenológico de elección, por su alta sensibilidad (> 95%) y especificidad (>85%). Mediante estudio descriptivo retrospectivo, se analizó 82 casos con informes de PieloTAC, realizados por sospecha clínica de nefrourolitiasis, entre octubre de 2006 y marzo de 2007 en el Centro de Diagnóstico por Imágenes Diagnoimage de Antofagasta. En el 56,10% de los casos se confirmó nefrourolitiasis, con predominio de ubicación renal en el 57,63%. Un 30,56% de los pacientes sin litiasis, presentó flebolitos pelvianos, quistes renales y granuloma cálcico. Se concluye que en esta serie PieloTAC proporcionó un diagnóstico imagenológico de alta sensibilidad y especificidad para nefrourolitiasis, reportando tamaño, localización y composición de los cálculos, como también diagnósticos diferenciales con otras patologías, mostrando como ventajas el corto tiempo de ejecución, no usar medio contraste y ser operador independiente.

Antígeno carcinoembrionario: implementación regional de la técnica / Carcinoembryonic antigen: regional implementation of the technic

Se determina CEA (antígeno carcinoembrionario) en plasma de 196 voluntarios, aparentemente sanos, encuestados en cuanto a edad, sexo, raza, hábito tabáquico y uso o no de fogón (costumbre mapuche). Se demuestra diferencia estadísticamente significativa en cuanto a: 1) aumento de los títulos en las edades mayores, independientes del sexo, raza y hábito tabáquico y 2) aumento de los títulos en los (F) fumadores, en relación a los (NF) no fumadores, independientes del sexo y raza. Se construye nomograma de distribución, con ecuación de regresión + 2SD para F y NF, delimitándose un 95% de posibilidades de pertenecer al área de normalidad en una curva de distribución normal, como primera fase en la implementación de la técnica en la IX región, Chile