Neutralization of SARS-CoV-2 (lineage B.1.1) by hyperimmune llama (Lama glama) serum in vero cell culture. / Neutralización del virus SARS-CoV-2 (linaje B.1.1) por suero hiperinmune de llama (Lama glama) en cultivo de células Vero.

OBJECTIVE.: To evaluate the serological antibody response of a llama (Lama glama) to SARS-CoV-2 (B.1.1 lineage) immunization and the neutralizing capacity of hyperimmune llama serum against SARS-CoV-2 virus (B.1.1 lineage) in Vero cells. MATERIALS AND METHODS.: A llama was immunized with inactivated SARS-CoV-2 (B.1.1 lineage). Serum samples were analyzed to evaluate the level of antibodies by ELISA, as well as reactivity to SARS-CoV-2 antigens by Western Blot. In addition, viral neutralization in cell cultures was assessed by the Plate Reduction Neutralization Test (PRNT). RESULTS: . Seroreactivity increased in the immunized llama from week 4 onwards. Antibody titers were the highest after the seventh immunization booster. Western blot results confirmed the positive ELISA findings, and immune serum antibodies recognized several viral proteins. The neutralization assay (PRNT) showed visible viral neutralization, which was in accordance with the ELISA and Western Blot results. CONCLUSIONS.: The findings suggest that hyperimmune llama serum could constitute a source of therapeutic antibodies against SARS-CoV-2 infections (lineage B.1.1), and should be studied in further research.

OBJETIVO.: Evaluar la respuesta serológica de anticuerpos de una llama (Lama glama) a la inmunización del virus SARS-CoV-2 (linaje B.1.1) y la capacidad neutralizante del suero de llama hiperinmune frente al virus SARS-CoV-2 (linaje B.1.1) en células Vero. MATERIALES Y MÉTODOS.: Se inmunizó una llama con el virus SARS-CoV-2 inactivado (Linaje B.1.1) y se analizaron muestras de suero para evaluar el nivel de anticuerpos mediante ELISA, así como la reactividad a antígenos de SARS-CoV-2 mediante Western Blot. Además, se evaluó la neutralización viral en cultivos celulares por la Prueba de Neutralización por Reducción de Placas (PRNT, por sus siglas en inglés). RESULTADOS.: Se observó un aumento en la serorreactividad en la llama inmunizada desde la semana 4 en adelante. Los títulos de anticuerpos fueron más elevados en el séptimo refuerzo de inmunización. Los resultados de Western Blot confirmaron los hallazgos positivos del ELISA, y los anticuerpos del suero inmune reconocieron varias proteínas virales. El ensayo de neutralización (PRNT) mostró una neutralización viral visible, concordante con los resultados de ELISA y Western Blot. CONCLUSIONES.: Los hallazgos sugieren que el suero hiperinmune de llama podría constituir una fuente de anticuerpos terapéuticos contra las infecciones por el virus SARS-CoV-2 (linaje B.1.1) y que deberá ser evaluado en estudios posteriores.

Development of Nanobodies Against Hemorrhagic and Myotoxic Components of Bothrops atrox Snake Venom.

Snake envenoming is a globally neglected public health problem. Antivenoms produced using animal hyperimmune plasma remain the standard therapy for snakebites. Although effective against systemic effects, conventional antivenoms have limited efficacy against local tissue damage. In addition, potential hypersensitivity reactions, high costs for animal maintenance, and difficulties in obtaining batch-to-batch homogeneity are some of the factors that have motivated the search for innovative and improved therapeutic products against such envenoming. In this study, we have developed a set of nanobodies (recombinant single-domain antigen-binding fragments from camelid heavy chain-only antibodies) against Bothrops atrox snake venom hemorrhagic and myotoxic components. An immune library was constructed after immunizing a Lama glama with whole venom of B. atrox, from which nanobodies were selected by phage display using partially purified hemorrhagic and myotoxic proteins. Biopanning selections retrieved 18 and eight different nanobodies against the hemorrhagic and the myotoxic proteins, respectively. In vivo assays in mice showed that five nanobodies inhibited the hemorrhagic activity of the proteins; three neutralized the hemorrhagic activity of whole B. atrox venom, while four nanobodies inhibited the myotoxic protein. A mixture of the anti-hemorrhagic and anti-myotoxic nanobodies neutralized the local tissue hemorrhage and myonecrosis induced by the whole venom, although the nanobody mixture failed to prevent the venom lethality. Nevertheless, our results demonstrate the efficacy and usefulness of these nanobodies to neutralize important pathologies of the venom, highlighting their potential as innovative therapeutic agents against envenoming by B. atrox, a viperid species causing many casualties in South America.

Relación de la edad cronológica con la maduración ósea cervical mediante el método de Baccetti / Relationship of the chronological age with cervical bone maturation through the Baccetti method

Introducción: Es importante valorar el momento ideal en el que se producen los cambios tanto biológicos como estructurales en el crecimiento y desarrollo de los maxilares, para identificar en qué momento se inicia del crecimiento puberal en los pacientes jóvenes y corregir las alteraciones tanto dentarias como esqueléticas que se puedan presentar. Objetivo: Evaluar los estadios de maduración de las vértebras cervicales mediante el análisis propuesto por Baccetti y su relación con la edad cronológica y el sexo, en radiografías laterales de individuos de 8 a 14 años. Metodología: Estudio transversal, retrospectivo y descriptivo. Se evaluaron 280 radiografías laterales (140 de varones y 140 de mujeres). Un evaluador calibrado evaluó los estadios de maduración esquelética e identificó 6 de ellas. Se evaluó el pico de crecimiento de los individuos desde la segunda a la cuarta vértebra cervical en las radiografías y luego se relacionó con la edad y el sexo de los individuos. Se utilizaron las pruebas de asociación de Chi cuadrado p < 0,05. Resultados: En las edades de 11 y 12 años se observó que las mujeres tenían mayor grado de madurez que los varones; sin embargo, para apreciar mejor los resultados, se reagruparon según los estadios: 1 con 2, 3 con 4 y 5 con 6, y se encontraron diferencias estadísticamente significativas entre ellos (p < 0,001). Conclusiones: Existe asociación en el diagnóstico del pico de crecimiento y la maduración ósea de los pacientes según su edad cronológica, con una clara diferencia entre varones y mujeres, lo que evidencia que el método de Baccetti se pueda emplear de manera confiable en la población estudiada. (AU)

Introduction: In Orthodontics, it is important to assess the ideal moment where changes occur, both biological and structural in relation to the growth and development of the jaws, thus identifying, at what time, the onset of pubertal growth in young patients and substantiate their dental correction as skeletal, achieving a positive result through its planning and application, correcting its discrepancies or alterations that may occur. Objective: To evaluate the stages of maturation of the cervical vertebrae through the analysis proposed by Baccetti and its relationship with chronological age according to age and sex, on lateral head X-rays of individuals aged 8 to 14 years. Methodology: This was a crosssectional, retrospective, descriptive study. 280 lateral head X-rays were evaluated (140 men and 140 women). A trained and calibrated evaluator evaluated the stages of skeletal maturation with the method proposed by Baccetti, identifying 6 stages. The peak of growth of the individuals was evaluated through the second to the fourth cervical vertebra on radiographs and then related to the chronological age and sex of the individuals. Chi square association tests were used p < 0.05. Results: In the ages of 11 and 12, it is observed that women have a greater degree of maturity than men, however, in order to better appreciate the results, they were regrouped according to the stages of maturity of cervical vertebrae 1 with 2, 3 with 4 and 5 with 6 and statistically significant differences were found between the stages of maturation of the cervical vertebrae according to age and sex (p < 0.001). Conclusions: There is an association in the diagnosis of peak growth and bone maturation of patients according to their chronological age, producing a clear difference between men and women, which shows that the Baccetti method can be used reliably in the population studied. (AU)

Caracterización y optimización del antígeno del líquido hidatídico de ovino y su aplicación en la prueba de látex / Characterization and optimization of sheep hydatid fluid antigen and its application in the latex test

Se caracterizó y optimizó el antígeno del líquido hidatídico de ovino y se aplicó en la prueba de látex como pruebatamiz para el diagnóstico serológico de pacientes con quistes de Echinococcus granulosus. Se evaluó 40 sueros, 15de hidatidosis positivos por inmunoblot, 10 de pacientes con otras enfermedades parasitarias y 15 de personas sanas.Tres de los 15 sueros de hidatidosis resultaron negativos y 0/25 sueros sin hidatidosis fueron reactivos. Se obtuvo una sensibilidad de 80 por ciento (IC95 por ciento: 56,4 a 100 por ciento), especificidad de 100 por ciento (96,7 a 100 por ciento), valor predictivo positivo de 100 por ciento (95,8 a 100 por ciento) y valor predictivo negativo de 83,3 (30,4 a 69,6 por ciento) y una concordancia del 100 por ciento al evaluar la repetibilidad y reproducibilidad de la prueba. Se recomienda el uso de esta prueba para el diagnóstico de la hidatidosis por ser simple, rápida y reproducible, como kit en laboratorio o en campo para estudios epidemiológicos.

It was characterized and optimized sheep hydatid fluid antigen and applied in latex fixation tests as screening test for serological diagnosis of patients with Echinococcus granulosus cysts. We evaluated 40 sera, 15 sera positive by immunoblot from patients with E. granulosus infection, 10 sera from patients with other parasitic diseases and 15 sera from healthy subject. Three of the 15 hydatidosis sera were negative and 0 / 25 sera with hydatidosis were reactive. The sensitivity was 80 per cent (95 per cent CI: 56.4 to 100 per cent), specificity was 100 per cent (96.7 to 100 per cent), positive predictive value of 100 per cent (95.8 to 100 per cent), negative predictive value of 83.3 (30.4 to 69.6 per cent), and repeatability and reproducibility of 100 per cent. We recommended the use of this test for the diagnosis of hydatid disease, because it is simple, fast and reproducible, as a kit in the laboratory or in epidemiological field studies.