Preparation and evaluation of formalized bivalent Newcastle and Salmonella poultry vaccine

This study was conducted to prepare and evaluate the potency of different inactivated vaccine formulations that protect chickens against Salmonella Enteritidis and Newcastle disease virus using Montanide as adjuvant. Protection and the humoral immune response of prepared vaccines against Salmonella Enteritidis and Newcastle disease virus was evaluated and compared to imported vaccine. In this study, different formulae of Salmonella Enteritidis and Newcastle disease vaccines were prepared and compared with the imported one by measuring the antibody titer against Newcastle disease virus by hemagglutination inhibition test and the antibody titer against Salmonella Enteritidis using Enzyme Linked Immunosorbent Assay. On the other hand, the protection percentages against Newcastle disease and Salmonella Enteritidis were recorded to determine the best effective formula. The highest hemagglutination inhibition antibody level against NDV at first week was recorded for the prepared combined Newcastle disease and Salmonella Enteritidis vaccine (4.2 log2) followed by the prepared monovalent Newcastle disease (3.4 log2); the lowest antibody level (3.1 log2) was obtained with the imported vaccine. A gradual increase was observed in all groups to 7.1 log2, 6.8 log2 and 6.4 log2 at fourth week post vaccination, respectively. The antibody titer against Salmonella Enteritidis was 552 for the prepared combined Salmonella Enteritidis and Newcastle disease, followed by the prepared monovalent Salmonella Enteritidis (477) at first week post vaccination; the antibody titer obtained for the imported vaccine was 477. There was a gradual increase to 1456, 1406 and 1130 at fourth week post vaccination, respectively. Prepared combined vaccines gave the highest protection percentage, followed by prepared monovalent types and finally imported vaccines. Vaccination by the prepared combined Salmonella Enteritidis and Newcastle disease vaccine may be a way to increase the resistance of birds to Salmonella and Newcastle and to decrease the shedding rate(AU)

Este estudio se llevó a cabo para preparar y evaluar la potencia de diferentes formulaciones de vacunas inactivadas que protegen a los pollos contra Salmonella Enteritidis y el virus de la enfermedad de Newcastle utilizando Montanide como adyuvante. Se evaluó la protección y la respuesta inmune humoral de las vacunas preparadas contra Salmonella Enteritidis y el virus de la enfermedad de Newcastle y se comparó con la vacuna importada. En este estudio se prepararon diferentes fórmulas de vacunas contra Salmonella Enteritidis y la enfermedad de Newcastle y se compararon con la importada midiendo el título de anticuerpos contra el virus de la enfermedad de Newcastle mediante la prueba de inhibición de la hemaglutinación y el título de anticuerpos contra Salmonella Enteritidis mediante ELISA. Por otra parte, se registraron los porcentajes de protección contra la enfermedad de Newcastle y Salmonella Enteritidis para determinar la fórmula más eficaz. El mayor nivel de anticuerpos inhibidores de la hemaglutinación contra el virus de la enfermedad de Newcastle, en la primera semana, se registró con la vacuna combinada preparada contra la enfermedad de Newcastle y Salmonella Enteritidis (4,2 log2), seguida de la vacuna monovalente preparada contra la enfermedad de Newcastle (3,4 log2); el menor nivel de anticuerpos (3,1 log2) se obtuvo con la vacuna importada. Se observó un aumento gradual en todos los grupos hasta alcanzar 7,1 log2, 6,8 log2 y 6,4 log2 en la cuarta semana tras la vacunación, respectivamente. El título de anticuerpos contra Salmonella Enteritidis fue de 552 para la vacuna combinada preparada contra la Salmonella Enteritidis y enfermedad de Newcastle, seguida por la vacuna monovalente preparada contra Salmonella Enteritidis (477) en la primera semana después de la vacunación; el título de anticuerpos obtenido con la vacuna importada fue de 477. Hubo un aumento gradual hasta 1456, 1406 y 1130 en la cuarta semana después de la vacunación, respectivamente. Las vacunas combinadas preparadas dieron el mayor porcentaje de protección, seguidas por los tipos monovalentes preparados y, por último, por las vacunas importadas. La vacunación con la vacuna combinada preparada contra la Salmonella Enteritidis y la enfermedad de Newcastle puede ser una forma de aumentar la resistencia de las aves a la Salmonella y Newcastle y de disminuir la tasa de excreción(AU)

Niveles de protección contra Haemophilus influenzae tipo b en niños, adolescentes y adultos cubanos / Levels of protection against Haemophilus influenzae type b in Cuban children, adolescents and adults

La concentración de los anticuerpos contra el polisacárido capsular polirribosilribitol fosfato del Haemophilus influenzae tipo b se considera un buen indicador serológico para evaluar protección contra la enfermedad invasiva. Existen pocos reportes que estudien la inmunidad serológica en Cuba. El objetivo general de este estudio fue determinar los niveles de protección séricos contra Haemophilus influenzae tipo b en niños, adolescentes y adultos cubanos, en una muestra de 575 individuos. Se cuantificó la concentración de IgG anti-polirribosilribitol fosfato de Haemophilus influenzae tipo b mediante un inmunoensayo enzimático estandarizado y validado en el laboratorio de inmunología del Centro Nacional de Genética Médica, La Habana, Cuba. Se determinaron las concentraciones medias geométricas de anticuerpos y los niveles de protección frente a la enfermedad invasiva por Haemophilus influenzae tipo b. La concentración media geométrica de IgG anti-polirribosilribitol fosfato fue de 1,94 μg/mL (IC95 por ciento 1,80; 2,08) y fue mayor en el grupo de 16 a 22 años. El porcentaje con protección de larga duración fue mayor para el sexo femenino que para el masculino (82,2 por ciento vs 71,4 por ciento; p=0,0339) entre los que poseían inmunidad natural. El grupo de sujetos nacidos en el periodo en que se vacunó con la vacuna conjugada cubana QUIMI-HIB® presentó concentraciones medias geométricas superiores (2,75 μg/mL, IC95 por ciento 2,00; 3,79). El 99,1 por ciento de los participantes presentó protección frente a la enfermedad invasiva por Haemophilus influenzae tipo b, el 19,8 por ciento a corto plazo y el 79,3 por ciento protección de larga duración. El inmunoensayo validado para la cuantificación de IgG anti-polirribosilribitol fosfato podría emplearse en estudios de seroprevalencia. En los sujetos estudiados, se encontró un predominio de elevadas concentraciones de IgG anti- polirribosilribitol fosfato del Haemophilus influenzae tipo b que confieren protección de larga duración(AU)

The levels of antibodies directed against the capsular polysaccharide polyribosylribitol phosphate of Haemophilus influenzae type b are considered a good serological indicator to assess the immunity against invasive disease. In Cuba, there are few reports that study serological immunity. The general objective was to determine serum protection levels against Haemophilus influenzae type b in Cuban children, adolescents and adults, in a sample of 575 Cuban individuals. The concentration of IgG against Haemophilus influenzae type b was quantified by means of an indirect ELISA standardized and validated in the immunology laboratory of the National Center of Medical Genetics, Havana, Cuba. The geometric mean concentration of IgG anti- polyribosylribitol phosphate and the levels of protection against invasive Haemophilus influenzae type b disease were determined. The geometric mean concentration of IgG anti- polyribosylribitol phosphate was 1.94 μg/mL (95percentCI 1.80;2.08) and the group from 16 to 22 years old presented the highest. Among those with natural immunity, the percentage with long-term protection was higher for females vs. males (82.2percent vs. 71.4percent; p=0.0339). The group of subjects born in the period in which they were vaccinated with the Cuban conjugate vaccine QUIMI-HIB® presented higher geometric mean concentration (2.75 μg/mL, CI95percent 2.00; 3.79). The 99.1percent of the participants had protection against invasive Haemophilus influenzae type b disease, 19.8percent short-term and 79.3percent long-term protection. The ELISA for the quantification of anti- Haemophilus influenzae type b IgG antibodies, developed and validated, could be used in seroprevalence studies. In the subjects studied, there was a predominance of high IgG anti- Haemophilus influenzae type b polyribosylribitol phosphate concentration values that confer long-term protection(AU)

Effects of oxycodone hydrochloride and dezocine on hemodynamics and levels of inflammatory factors in patients receiving gynecological laparoscopic surgery under general anesthesia

Abstract We aimed to compare the effects of oxycodone hydrochloride and dezocine on hemodynamics and inflammatory factors in patients receiving gynecological laparoscopic surgery under general anesthesia. A total of 246 patients were divided into group A and B (n=123). Hemorheology indices were recorded 5 min after anesthesia (T0), 1 min after pneumoperitoneum (T1), when position was changed 5 min after pneumoperitoneum (T2), 15 min after pneumoperitoneum (T3), 1 min (T4) and 5 min (T5) after position was restored. Visual analogue scale scores 1, 2, 6, 12, 24 and 48 h after operation were recorded. Postoperative adverse reactions and visceral pain were observed. The expression levels of inflammatory factors were detected by enzyme-linked immunosorbent assay 12 h after operation. Compared with group A, group B had higher heart rate and mean arterial pressure at T2, lower central venous pressure and cardiac output at T1-T3, and higher systemic vascular resistance at T1-T5 (P<0.05). The incidence rate of pain syndrome in group A was lower (P<0.05). Group A had lower tumor necrosis factor-alpha and interleukin-6 expression levels and higher interleukin-10 level than those of group B (P<0.05). For gynecological laparoscopic surgery, oxycodone preemptive analgesia has superior outcomes to those of dezocine

Autoanticuerpos anti-insulina en la diabetes tipo 1 / Anti-insulin autoantibodies in type 1 diabetes

Introducción: Los autoanticuerpos anti-insulina (AAI) representan un marcador serológico de la diabetes tipo 1 (DT1). El significado clínico de los AAI aún no ha sido determinado en la población cubana. Objetivo: Determinar el valor clínico de AAI en pacientes con DT1. Métodos: Se determinaron los niveles séricos de AAI por el ensayo inmuno-adsorbente ligado a enzima (ELISA) en 33 pacientes adultos con DT1, 78 pacientes con otras condiciones endocrinas (CEE) como diabetes tipo 2, tiroiditis de Hashimoto e hiperinsulinemia, y 49 controles normales (CN). El valor de corte se determinó con el análisis de las curvas características operativas del receptor (COR) (ROC por sus siglas en inglés). Se utilizaron pruebas no paramétricas para comparar los niveles de AAI de pacientes con DT1, CEE y CN, y determinar la correlación entre AAI y la edad. Resultados: El valor de corte óptimo de AAI para DT1 fue el índice de 1,05, con sensibilidad de 45,5 por ciento, especificidad de 81,6 por ciento, razón de verosimilitud positiva de 2,47, y razón de verosimilitud negativa de 0,67. Los niveles de AAI en DT1 (índice de 0,97) fueron significativo, más altos que los de CN (índice de 0,70; p=0,020) y los de CEE (índice de 0,63; p= 0,009). Los niveles de AAI resultaron inversamente proporcionales a la edad en pacientes diabéticos ( =-0,252; p=0,030). Conclusiones: Los pacientes con DT1 se distinguieron por niveles más altos de AAI, aunque la presencia de estos anticuerpos no fue exclusiva de DT1. Los niveles de AAI dependieron de la edad en los pacientes diabéticos(AU)

Introduction: Anti-insulin autoantibodies (AAI) represent a serological marker of type 1 diabetes (T1D). The clinical significance of AAIs has not yet been determined in the Cuban population. Objective: To determine the clinical value of AAI in patients with T1D. Methods: AAI serum levels were determined by enzyme-linked immunosorbent assay (ELISA) in 33 adult patients with T1D, 78 patients with other endocrine conditions (CEE) such as type 2 diabetes, Hashimoto's thyroiditis, and hyperinsulinemia, and 49 normal controls (CN). The cut-off value was determined by receiver operating characteristic (ROC) curve analysis. Nonparametric tests were used to compare the AAI levels of patients with T1D, CEE, and CN, and to determine the correlation between AAI and age. Results: AAI optimal cut-off value for T1D was the index of 1.05, with 45.5 percent of sensitivity, 81.6 percent specificity, 2.47 positive likelihood ratio, and 0.67 negative likelihood ratio. AAI levels in DT1 (index of 0.97) were significant, higher than those of CN (index of 0.70; p= 0.020) and CEE levels (index of 0.63; p= 0.009). AAI levels were inversely proportional to age in diabetic patients (ρ = -0.252; p=0.030). Conclusions: Patients with T1D were distinguished by AAI higher levels, although the presence of these antibodies was not exclusive to T1D. AAI levels depended on age in diabetic patients(AU)

Comparative efficacy of different Carbopol concentrations as a stabilizer of live attenuated sheep pox virus vaccine against lumpy skin disease

In Egypt, the lyophilized live attenuated sheep pox virus vaccine has been used for the vaccination of cattle against lumpy skin disease virus to control its economic impact on livestock industry. In this endeavor, we validate the efficacy of Carbopol® as a stabilizer and adjuvant to enhance immunogenicity of such a heterologous sheep pox virus vaccine against lumpy skin disease. Lyophilization of sheep pox virus vaccine stabilized with Carbopol® produced better physical and antigenic properties than freeze-drying with lactalbumin/sucrose stabilizer; this was manifested by superior disc uniformity, thermo-stability at 37oC, and less reduction in virus titer. Immunization of calves' groups with variable sheep pox vaccine doses containing different Carbopol® concentrations revealed that 103.5 TCID50 of sheep pox virus vaccine enclosing 0.5 percent Carbopol® is the field dose of choice. Moreover, it induced protective serum neutralizing index of 2.5 and a ELISA S/P ratio of 36, by the 4th week post vaccination. Besides, the inclusion of 0.5 percent Carbopol® in formulation of the sheep pox virus vaccine was safe in bovines and enhanced cellular immune response to lumpy skin disease virus, as evidenced by increased T cell proliferation. Hence, it is recommended to use Carbopol® as 0.5 percent in preparation of live attenuated sheep pox virus vaccine to confer better protection against lumpy skin disease virus infection(AU)

En Egipto, la vacuna atenuada liofilizada contra el virus de la viruela ovina ha sido utilizado para la vacunación del ganado, contra el virus de la dermatosis nodular contagiosa, para controlar su impacto económico en la industria ganadera. En este trabajo, validamos la eficacia del Carbopol®, como estabilizador y adyuvante, para mejorar la inmunogenicidad de dicha vacuna heteróloga contra la dermatosis nodular contagiosa. La liofilización de la vacuna contra el virus de la viruela ovina estabilizada con Carbopol®, resultó en mejores propiedades físicas y antigénicas que la liofilización con el estabilizador de lactoalbúmina/sacarosa; lo anterior se manifestó en la uniformidad superior del disco, la termoestabilidad a 37°C y la menor reducción del título del virus. La inmunización de grupos de terneros con dosis variables de vacuna contra el virus de la viruela ovina, que contenían diferentes concentraciones de Carbopol®, reveló que la dosis de campo de elección fue 103,5 TCID50 de la vacuna contra el virus de la viruela ovina conteniendo 0,5 por ciento de Carbopol®, la que indujo un índice de neutralización sérica protectora de 2,5 y una relación S/P de ELISA de 36 a la cuarta semana después de la vacunación. Además, la inclusión de Carbopol® al 0,5 por ciento en la formulación de la vacuna contra el virus de la viruela ovina fue segura en los bovinos y potenció la respuesta inmunitaria celular contra el virus de la dermatosis nodular contagiosa, como lo demuestra el aumento de la proliferación de células T. Por lo tanto, se recomienda el uso de Carbopol® al 0,5 por ciento en la preparación de la vacuna viva atenuada contra el virus de la viruela ovina para conferir una mejor protección contra la infección por el virus de la dermatosis nodular contagiosa(AU)

Antígeno nativo y no nativo para determinar la seroprevalencia de Trypanosoma cruzi en mujeres embarazadas en el estado de Morelos, México / Native and non-native antigen to determine the seroprevalence of Trypanosoma cruzi in pregnant women from the state of Morelos, Mexico

INTRODUCCIÓN: La enfermedad de Chagas es una infección parasitaria crónica sistémica, de importancia global, causada por Trypanosoma cruzi. OBJETIVO: Determinar la prevalencia de anticuerpos contra T cruzi en mujeres embarazadas en el estado de Morelos, México. MATERIALES Y MÉTODOS: Se analizaron 1.620 sueros de mujeres embarazadas mediante dos pruebas serológicas: ELISAc (antígeno crudo nativo) y ELISAr (antígeno recombinante, no nativo). Las muestras reactivas se analizaron posteriormente mediante hemaglutinación indirecta (HAI). Se utilizaron dos enfoques de detección, en paralelo (son positivas las muestras reactivas por cualquier método) y en serie (son positivas las muestras confirmadas por HAI). Se evaluaron factores sociodemográficos y de salud asociados a la presencia de anticuerpos contra T. cruzi mediante razones de momios al 95%. RESULTADOS: Se obtuvo una seroprevalencia de 4,87% con el diagnóstico en paralelo y de 0,43% en serie. A partir de los resultados en paralelo las mujeres que fueron atendidas en los hospitales generales de Tetecala y Jojutla tuvieron, respectivamente, 2,2 y 2,0 veces mayor posibilidad de presentar anticuerpos contra T cruzi con respecto a las mujeres que fueron atendidas en el Hospital General de Cuautla. CONCLUSIÓN: La prevalencia de anticuerpos contra T cruzi en mujeres embarazadas en el estado de Morelos fluctuó entre 0,43 y 4,87%, según el antígeno y el abordaje utilizado. Es necesario continuar con la vigilancia de la seroprevalencia de anticuerpos contra T cruzi en mujeres embarazadas en el estado de Morelos, México, con las técnicas de mayor sensibilidad y especificidad disponibles.

BACKGROUND: Chagas disease is a globally important chronic systemic parasitic infection caused by Trypanosoma cruzi. AIM: To determine the prevalence of antibodies against T cruzi in pregnant women from the state of Morelos, México. METHODS: 1,620 sera from pregnant women were analyzed using two serological tests: ELISAc (native crude antigen) and ELISAr (recombinant, non-native antigen). Reactive samples were subsequently analyzed by indirect hemagglutination (IHA). Two detection approaches were used, in parallel (reactive samples by any method are positive) and serial (samples confirmed by IHA are positive). Sociodemographic and health factors associated with the presence of antibodies against T cruzi were evaluated using 95% odds ratios. RESULTS: A seroprevalence of 4.87% was obtained with parallel diagnosis and 0.43% in series. From the parallel results, the women who were attended at the general hospitals of Tetecala and Jojutla had respectively 2.2 and 2.0 times greater chance of presenting antibodies against T cruzi compared to the women who were attended at the General Hospital of Cuautla. CONCLUSION: The prevalence of antibodies against T cruzi in pregnant women from the state of Morelos fluctuated between 0.43 and 4.87%, depending on the antigen and the approach used. It is necessary to continue with the surveillance of the seroprevalence of antibodies against T cruzi in pregnant women from the state of Morelos, Mexico, using the techniques with the highest sensitivity and specificity available.

A monoclonal antibody-based icELISA for puerarin / 中国中药杂志

Puerarin was conjugated with bovine serum albumin(BSA) and ovalbumin(OVA) by periodate oxidation to serve as the immunogen and coating antigen, respectively. BALB/c mice were immunized with puerarin-BSA according to the routine immunization procedure, and the titer and specificity of serum were detected after three immunization. After booster immunization, mouse spleen lymphocytes were fused with mouse myeloma cells, and 24 hybridoma cell lines of the monoclonal antibodies against puerarin were screened by monoclonal antibody screening technique. Ascites was prepared and purified. The cross-reactivity of monoclonal antibody(mAb) M1 with 4'-methoxy puerarin, daidzin, puerarin-6″-O-xyloside, daidzein, mirificin, 3'-methoxy puerarin, and 3'-hydroxy puerarin was 239.84%, 112.18%, 67.89%, 58.28%, 22.37%, 0.40%, and 0.20%, respectively, and those with other analogs such as baicalein and baicalin were all less than 0.10%. The IC_(50) and the working range of the indirect competitive enzyme-linked immunosorbent assay(icELISA) for puerarin were 44.80 ng·mL~(-1) and 8.20-292.30 ng·mL~(-1), respectively. The average recovery was 91.95%-98.20% with an RSD in the range of 0.70%-2.60%. The content of puerarin in different Puerariae Lobatae Radix samples was determined with icELISA and validated by UPLC-MS. The correlation between data obtained from icELISA and UPLC-MS was 0.999 0, indicating that icELISA is suitable for the rapid detection of puerarin in Puerariae Lobatae Radix samples.

Preliminary Study on Screening and Identification of Lewis a Antigen Mimic Epitope in Alpaca Phage Display Nanobody Library / 中国实验血液学杂志

OBJECTIVE@#To establish a new method for synthesizing Lewis blood group antigens, that is, the mimotopes of Lewis blood group antigens were screened by using an alpaca phage display nanobody library.@*METHODS@#We selected mimotopes of the Lewis a (lea) antigen by affinity panning of an alpaca phage display nanobody library using a monoclonal anti-lea antibody. Enzyme-linked immunosorbent assay (ELISA) was used to test the affinity of the positive clones for the monoclonal anti-lea antibody, and the high-affinity positive clones were selected for sequencing and synthesis. Finally, the sensitivity, specificity and reactivity of the synthesized lea mimotope in clinical samples were verified by ELISA.@*RESULTS@#A total of 96 phage clones were randomly selected, and 24 were positive. Fourteen positive clones with the highest affinity were selected for sequencing. The result showed that there were 5 different sequences, among which 3 sequences with the highest frequency, largest difference and highest affinity were selected for expression and synthesis. The sensitivity and specificity of lea mimic antigen by ELISA showed that, the minimum detection limit of gel microcolumn assay (GMA) and ELISA method were 25 times different, and the lea mimic antigen had no cross reacted with the other five unrelated monoclonal antibodies(P<0.001). Finally, 30 clinical plasma samples were analyzed. The mean absorbance of the 15 positive plasma samples was significantly higher than that of the 15 negative plasma samples (P=0.02). However, the positive signal values of the clinical samples were much lower than those of the monoclonal antibodies.@*CONCLUSION@#A new method of screening lea mimic antigen by using alpaca phage nanoantibody library has been established, which is expected to realize the screening of lea mimotopes, thus realizing the application of high-sensitivity detection methods such as ELISA and chemiluminescence in blood group antibody identification.

Salidroside induced repair of myocardial infarction through Nrf2/HO-1

Abstract Salidroside (SAL) has been confirmed to have some protective effects against inflammatory injury. However, little information was established as to the mechanism of these protective effects. To this effect, we designed this study to explore the protective effects and mechanisms of SAL against myocardial infarction (MI). A rat MI model was established and divided into five groups (n = 6): sham, MI, MI+SAL, MI+ LY294002 (PI3K inhibitor), and MI+SAL+ LY294002. The cardiac function and histological pathology were analyzed with a color Doppler ultrasonic diagnostic instrument. Anti-oxidative enzyme activities and the production of inflammatory media were assayed by biochemical kits and ELISA. MI size and fibrosis were assayed by Masson's trichrome staining while Bax/Bcl-2 and PI3K/Akt/Nrf2/HO-1 were assayed by Western blotting and immunofluorescence. The results showed that SAL significantly improved the left ventricle ejection fraction and fractional shortening, decreased the MI size and fibrosis, inhibited apoptosis and promoted blood vessel formation. SAL promoted anti-oxidative and anti-inflammatory abilities. Moreover, SAL enhanced PI3K/ Akt/Nrf2/HO-1 expression. To this effect, we designed this study suggested that SAL induced repair of MI via PI3K/A kt/ Nrf2/HO-1.

Formulation and evaluation of the vascular endothelial growth factor loaded polycaprolactone nanoparticles

Abstract In an attempt to increase molecular stability and provide controlled release, vascular endothelial growth factor (VEGF) was encapsulated into polycaprolactone (PCL) nanoparticles. Both VEGF-free and VEGF-loaded PCL nanoparticles were formulated by w/o/w double emulsion of the dichloromethane-water system in the presence of polyvinyl alcohol (PVA) and rat serum albumin. To achieve the optimal formulation concerning particle size and monodispersity, studies were carried out with different formulation parameters, including PVA concentration, homogenization time and rate. Scanning electron microscopy and dynamic light scattering analysis showed respectively that particles had a spherical shape with a smooth surface and particle size varying between 58.68-751.9 nm. All of the formulations were negatively charged according to zeta potential analysis. In vitro release study was performed in pH 7.4 phosphate-buffered saline at 37°C and released VEGF amount was measured by enzyme-linked immunosorbent assay (ELISA) method. At the end of the 35th day, 10% of total encapsulated VEGF was released with a sustained-release profile, which fitted the Korsmeyer-Peppas kinetic model. The bioactivation of the nanoparticles was evaluated using XTT and ELISA methods. As a result, the released VEGF was biologically active and also VEGF loaded PCL nanoparticles enhanced proliferation of the human umbilical vein endothelial cells in cell culture.

Therapeutic effects of benzoylaconitine and paeoniflorin in rats with collagen-induced arthritis

Abstract To explore the effects and mechanisms of benzoylaconitine and paeoniflorin on collagen-induced arthritis (CIA) rats. Weight, paw swelling, arthritis index and joint pathologic changes were examined in each group after CIA induction. PGE2, IL-1ß, IL-6, IL-10, TNF-α, VEGF, MMP-3, IgG and anti-CII Ab were assessed by ELISA; STAT1 and STAT3 expressions were analyzed immunohistochemically, and the ultrastructure of synovial cells was observed by transmission electron microscopy. Therapeutic effects were determined in CIA rats via injecting benzoylaconitine and paeoniflorin, which could alleviate the degree of swelling and arthritis index (AI) and pathological lesions of the sacroiliac gland; decrease the levels of PGE2, IL-1ß, TNF-α, VEGF and IgG in serum; reduce STAT1 and STAT3 expression in the membrane tissue; and inhibit the secretion and proliferation of synovial cells. These results showed that benzoylaconitine and paeoniflorin could significantly palliate the arthritic symptoms of CIA rats, and better therapeutic effects could be achieved if the two components were used in combination

Validación de pruebas rápidas de COVID-19. Isla de la Juventud, Cuba / COVID-19 rapid test validation. Isla de la Juventud, Cuba

Contar con métodos diagnósticos que reúnan ciertos atributos es vital para guiar las decisiones sanitarias, el contexto actual lo amerita. Con el objetivo de validar la capacidad de dos pruebas rápidas para detectar anticuerpos debido a la infección por SARS-CoV-2 en la Isla de la Juventud, Cuba, de abril a mayo de 2020, se realizó un estudio descriptivo de corte transversal de evaluación de pruebas rápidas: Wondfo (SARS-CoV-2 antibody test) y Lungene covid-19 IgG/IgM rapid test, en comparación con la prueba de reacción en cadena de la polimerasa en tiempo real. Se construyeron dos muestras homogéneas de 250 cada una, determinándose indicadores de validación. Se obtuvieron valores de sensibilidad de 6,6 por ciento y 8,3 por ciento respectivamente para cada prueba, mientras que la especificidad resultó superior para Wondfo (95 por ciento). Los valores predictivos positivos resultaron muy bajos, los negativos adecuados, superior en Lungene con el 94,8 por ciento. Los valores de razón de verosimilitud fueron clasificados como inútiles. En diferentes escenarios en cuanto a casos sintomáticos, se alcanzó sensibilidad del 50 por ciento en intervalo de 1 a 7 días para Wondfo. El área bajo la curva ROC para Wondfo fue 0,50 (IC95 por ciento=0,46-0,55) y para Lungene 0,46 (IC95 por ciento=0,38-0,55). El índice kappa para Wondfo fue de 0,025 y 0,010 para Lungene. Las pruebas rápidas exploradas mostraron muy baja sensibilidad, valor predictivo positivo y razón de verosimilitud inadecuada. La validez global de las pruebas no demostró un buen desempeño diagnóstico, marcado por el valor del área bajo la curva ROC(AU)

Having diagnostic methods that meet certain attributes is vital to guide health decisions, the current context warrants it. In order to validate the capacity of two rapid tests to detect antibodies due to SARS-CoV-2 infection in Isla de la Juventud, Cuba, from April to May 2020, a descriptive cross-sectional evaluation study was carried out. Rapid tests: Wondfo (SARS-CoV-2 antibody test) and Lungene covid-19 IgG/IgM, were compared to the real-time polymerase chain reaction test. Two homogeneous samples of 250 each were constructed, determining validation indicators. Sensitivity values of 6.6 percent and 8.3 percent respectively were obtained for each test, while the specificity was higher for Wondfo (95 percent). The positive predictive values were very low, the negative ones were adequate, higher in Lungene with 94.8 percent. Likelihood ratio values were classified as useless. In different scenarios in terms of symptomatic cases, sensitivity of 50 percent was reached in an interval of 1 to 7 days for Wondfo. The area under the ROC curve for Wondfo was 0.50 (95 percent CI = 0.46-0.55) and 0.46 for Lungene (95 percent CI = 0.38-0.55). The kappa index for Wondfo was 0.025 and 0.010 for Lungene. The rapid tests explored showed very low sensitivity, positive predictive value, and inadequate likelihood ratio. The global validity of the tests did not demonstrate a good diagnostic performance, marked by the value of the area under the ROC curve. The degree of agreement was poor(AU)

Relación entre condición nutricional, deterioro neurocognitivo, dependencia funcional y depresión en adultos mayores, Ilama, Honduras / Relationship between nutritional condition, neurocognitive impairment, functional dependence, and depression in elderly people, Ilama, Honduras

l virus SARS-CoV-2, es responsable de la enfermedad COVID-19; para su detección indirecta se utilizan inmunoensayos que cuantifican anticuerpos séricos contra algunas de sus proteínas. Objetivo: documentar resultados de la técnica ELISA, para la identificación cualitativa de anticuerpos contra SARS-CoV-2 en sujetos de Tegucigalpa y Comayagüela y la determinación de relevancia epidemiológica y clínica que presenta esta prueba. Material y Métodos: estudio correlacional transversal de 596 sujetos, a quienes se les practicó ELISA para la determinación de anticuerpos contra el SARS-CoV-2. Se recolectó datos epidemiológicos y clínicos del 13 de mayo al 31 de agosto 2020. Resultados: se analizó datos de 492 sujetos, 271 mujeres y 221 hombres, 313 de Tegucigalpa y 179 de Comayagüela. La edad media fue de 42.1 años; 253 tuvieron nexo epidemiológico negativo y 239 fueron positivos, se identificaron 88 profesiones, con base en la clasificación del Departamento de Trabajo de Estados Unidos y se categorizaron en grupos de riesgo bajo, medio y alto. Se encontraron 12 síntomas clínicos y 2 enfermedades concomitantes. De acuerdo al resultado de la prueba ELISA, los resultados se estructuraron en cuatro grupos: IgM e IgG negativos, IgM positivos, IgM e IgG positivos e IgG positivos, los que se asociaron con las variables epidemiológicas y clínicas. Los habitantes de Comayagüela presentaron mayor número de casos de ELISA positiva en comparación con los de Tegucigalpa. 1Facultad de Ciencias Médicas, UNAH. 2 Laboratorios Molina, Tegucigalpa, Honduras. 3 Western International School, San Pedro Sula. 4 Grupo de Investigación Historia. 5 Dirección General de Documentos Normativos, SESAL. 6 Grupo de Investigación Historia. 7 Departamento de Ciencias Fisiológicas, UNAH. Autor corresponsal: Mayra Gabriela Handal Lorenzana. mayr_gt@hotmail.com Recibido: 15/04/2021 Aceptado: 28/06/2021 Conclusiones: no hubo difer encia entr e edad (p=0.528) y sexo (p=0.245) en cuanto a los resultados del ELISA. Un tercio de los sujetos a los que se detectó algún anticuerpo no refirieron nexo epidemiológico. Las profesiones u ocupaciones más afectadas fueron las de riesgo medio y los síntomas identificados más frecuentes fueron fiebre, cefalea y odinofagia...(AU)

Relevancia epidemiológica y clínica de la técnica elisa para SARS-COV-2 en Tegucigalpa y Comayaguela, Honduras / Epidemiological and clinical relevance of the ELISA Technique for SARS-COV-2 in Tegucigalpa and Comayagüela, Honduras

El virus SARS-CoV-2, es responsable de la enfermedad COVID-19; para su detección indirecta se utilizan inmunoensayos que cuantifican anticuerpos séricos contra algunas de sus proteínas. Objetivo: documentar resultados de la técnica ELISA, para la identificación cualitativa de anticuerpos contra SARS-CoV-2 en sujetos de Tegucigalpa y Comayagüela y la determinación de relevancia epidemiológica y clínica que presenta esta prueba. Material y Métodos: estudio correlacional transversal de 596 sujetos, a quienes se les practicó ELISA para la determinación de anticuerpos contra el SARS-CoV-2. Se recolectó datos epidemiológicos y clínicos del 13 de mayo al 31 de agosto 2020. Resultados: se analizó datos de 492 sujetos, 271 mujeres y 221 hombres, 313 de Tegucigalpa y 179 de Comayagüela. La edad media fue de 42.1 años; 253 tuvieron nexo epidemiológico negativo y 239 fueron positivos, se identificaron 88 profesiones, con base en la clasificación del Departamento de Trabajo de Estados Unidos y se categorizaron en grupos de riesgo bajo, medio y alto. Se encontraron 12 síntomas clínicos y 2 enfermedades concomitantes. De acuerdo al resultado de la prueba ELISA, los resultados se estructuraron en cuatro grupos: IgM e IgG negativos, IgM positivos, IgM e IgG positivos e IgG positivos, los que se asociaron con las variables epidemiológicas y clínicas. Los habitantes de Comayagüela presentaron mayor número de casos de ELISA positiva en comparación con los de Tegucigalpa. 1Facultad de Ciencias Médicas, UNAH. 2 Laboratorios Molina, Tegucigalpa, Honduras. 3 Western International School, San Pedro Sula. 4 Grupo de Investigación Historia. 5 Dirección General de Documentos Normativos, SESAL. 6 Grupo de Investigación Historia. 7 Departamento de Ciencias Fisiológicas, UNAH. Autor corresponsal: Mayra Gabriela Handal Lorenzana. mayr_gt@hotmail.com Recibido: 15/04/2021 Aceptado: 28/06/2021 Conclusiones: no hubo difer encia entr e edad (p=0.528) y sexo (p=0.245) en cuanto a los resultados del ELISA. Un tercio de los sujetos a los que se detectó algún anticuerpo no refirieron nexo epidemiológico. Las profesiones u ocupaciones más afectadas fueron las de riesgo medio y los síntomas identificados más frecuentes fueron fiebre, cefalea y odinofagia.

Alternative method for the evaluation of monovalent inactivated foot and mouth disease virus vaccine

Foot and mouth disease is a highly contagious viral disease of cloven-hoofed animals that has a significant economic impact on livestock. A recent outbreak was detected and recorded as exotic strain of foot and mouth disease virus SAT2 (Serotype SAT2, topotype VII, Lib-12 lineage). The emergency vaccine was produced and assessed in vivo and large number of vaccine batches were urgently needed. The present work was aimed to provide a rapid evaluation of inactivated foot and mouth disease SAT2 oily vaccine to exclude the unsatisfactory batches during emergency circumstances and to reduce time, effort and cost. The extraction of foot and mouth disease antigen content from oily adjuvanted vaccine was carried out using isopropyl myristate and benzyl alcohol methods. The extracted viral antigen was identified by foot and mouse disease serotyping ELISA and 146S content was quantified using sucrose density gradient analysis. Evaluations were carried out instantly and at 2h, 6h and 24h. The results indicated the efficiency of benzyl alcohol to breakdown the oil emulsion either MONTANIDE™ ISA 206 VG or MONTANIDE™ ISA 50 V2, while the isopropyl myristate was efficient for MONTANIDE™ ISA 50 V2 only. The identification and quantification of 146S for extracted antigen using benzyl alcohol indicated significant stable records at different time intervals for the vaccine batches, while the extraction using isopropyl myristate indicated unstable records at different time intervals. It was concluded that the evaluation of monovalent foot and mouse disease vaccine could be conducted in vitro, using serotyping ELISA and quantification of 146S for the extracted antigen, either using benzyl alcohol or isopropyl myristate (MONTANIDE™ ISA50 V2 only), with the consideration that 146S content should not less than 4 μg/mL(AU)

La fiebre aftosa es una enfermedad viral altamente contagiosa de los animales de pezuña hendida que tiene un impacto económico significativo en el ganado. Se detectó un brote reciente que se registró como causado por una cepa exótica del virus de la fiebre aftosa (serotipo SAT2, topotipo VII, linaje Lib-12). La vacuna de emergencia se elaboró y evaluó in vivo, existiendo una urgente necesidad de contar con un gran número de lotes de la misma. El presente trabajo tuvo como objetivo proporcionar una evaluación rápida de la vacuna oleosa inactivada (SAT2) contra la fiebre aftosa, para excluir los lotes insatisfactorios durante circunstancias de emergencia, reduciendo tiempo, esfuerzo y costo. La extracción del contenido de antígeno de fiebre aftosa, de la vacuna oleosa adyuvada, se llevó a cabo utilizando miristato de isopropilo y alcohol bencílico. El antígeno viral extraído se identificó utilizando un ELISA de serotipificación y se cuantificó el contenido de 146S mediante análisis de gradiente de densidad de sacarosa. Las evaluaciones se realizaron de forma instantánea y a las 2h, 6h y 24h. Los resultados indicaron la eficacia del alcohol bencílico para separar la emulsión de aceite para MONTANIDE ™ ISA 206 VG o MONTANIDE™ ISA 50 V2, mientras que el miristato de isopropilo fue eficaz para MONTANIDE™ ISA 50 V2 únicamente(AU)

Proposal of an iELISA for Mycoplasma bovis diagnosis in dairy cattle and associated risk factors / [Proposta de um iELISA para diagnóstico de Mycoplasma bovis em bovinos leiteiros e fatores de risco associados]

Mycoplasma bovis is a highly contagious agent associated with several pathologies in cattle. The detection of reactive antibodies to M. bovis by Indirect Enzyme-Linked Immunosorbent Assay (iELISA) identifies if there was an exposure to the microorganism. The current study aimed to optimize an iELISA from M. bovis total cell antigen, applying it to bovine serum samples, and to evaluate risk factors. Serum samples were obtained from 400 cows from 17 herds from Southeast Brazil. In the optimization of iELISA, the following was established: 2 µg/mL of antigen, sera dilution 1:300, and conjugate dilution 1:15000. The frequency was 62.3% (249/400) of reactive animals and 100% (17/17) of reactive herds. Risk factors were: herds with more than 100 animals (OR= 3.1; CI= 95%); Holstein breed (OR= 72.5; CI= 95%); cows (OR= 29.7; CI= 95%); intensive breeding system (OR= 3.3; CI= 95%); associated small ruminant production (OR= 4.4; CI= 95%); milk production above 500L (OR= 2.9; CI= 95%); no quarantine (OR= 1.5; CI= 95%); mechanical milking (OR= 5.5; CI= 95%) and cases of mastitis (OR= 5.5; CI= 95%). The proposed iELISA was able to detect antibodies reactive to M. bovis in bovine serum. Knowledge of these risk factors can assist in the implementation of prophylactic measures.(AU)

Mycoplasma bovis é um agente altamente contagioso relacionado a várias patologias em bovinos. A detecção de anticorpos reativos a M. bovis por Ensaio de Imunoadsorção Enzimática Indireto (iELISA) identifica se houve exposição ao microrganismo. O presente estudo teve como objetivo otimizar um iELISA de antígeno celular total de M. bovis, aplicando-o a amostras de soro bovino, bem como avaliar fatores de risco. Amostras de soro foram obtidas de 400 vacas de 17 rebanhos da Região Sudeste do Brasil. Na otimização do iELISA foram obtidos: 2µg/mL de antígeno, diluição dos soros 1:300 e do conjugado 1:15000. A frequência de animais reativos foi de 62,3% (249/400) e de 100% (17/17) para os rebanhos. Os fatores de risco foram: rebanhos com mais de 100 animais (OR= 3,1; IC= 95%); raça Holandesa (OR= 72,5;IC= 95%); vacas (OR= 29,7;IC= 95%); sistema intensivo (OR= 3,3; C= 95%); produção de pequenos ruminantes (OR= 4,4;IC=95%); produção de leite acima de 500L (OR= 2,9;IC= 95%); sem quarentena (OR= 1,5;IC= 95%); ordenha mecânica (OR= 5,5;IC= 95%) e casos de mastite (OR= 5,5;IC= 95%). O iELISA proposto foi capaz de detectar anticorpos reativos a M. bovis no soro bovino. O conhecimento desses fatores de risco pode auxiliar na implementação de medidas profiláticas.(AU)

Significación de los marcadores infecciosos para identificar portadores de hepatitis B en donantes de sangre / Significance of hepatitis B surface antigen, IgM/IgG core antibody and hepatitis B virus DNA in blood donors

Resumen Introducción: La identificación de portadores del virus de la hepatitis B en donantes de sangre es imperativo para evitar la transmisión de la enfermedad a través de transfusiones sanguíneas. Objetivo: Determinar si los donantes de sangre con resultados positivos de los marcadores serológicos HbsAg y anti-HBc eran portadores de ADN del virus de la hepatitis B. Métodos: Se recolectaron 12 745 muestras de seis bancos de sangre ecuatorianos, las cuales fueron analizadas con pruebas serológicas para identificar los marcadores infecciosos HBsAg, anti-HBc, anti-HBs mediante prueba ELISA automatizada. Todas las muestras positivas para uno, dos o los tres marcadores fueron analizadas con técnica molecular para determinar la presencia de ADN viral. Resultados: Se identificó que 27.5 % de las muestras reactivas solo a anti-HBc y 100 % de las muestras con resultados positivos de HBsAg/anti-HBc-IgM/IgG presentaron ADN del virus de la hepatitis B (p = 0.001). Conclusiones: La elección de los marcadores de infección y los métodos de detección definen los resultados. Es importante la realización de dos pruebas serológicas y una molecular para identificar a los portadores del virus de la hepatitis B y evitar su transmisión.

Abstract Introduction: Identification of hepatitis B virus carriers in blood donors is imperative in order to avoid transmission of the disease via blood transfusion. Objective: To determine if blood donors with positive results for serological markers HBsAg and anti-HBc were hepatitis B virus DNA carriers. Methods: 12,745 samples were collected from six Ecuadorian blood banks and analyzed for HBsAg, anti-HBc and anti-HBs infectious markers by automated ELISA. All samples that tested positive for one, two or all three markers were analyzed with molecular techniques to determine the presence of viral DNA. Results: 27.5 % of the samples that were reactive for anti-HBc alone and 100 % of those with positive results for HbsAg and IgM/IgG anti-HBc were identified to contain hepatitis B virus DNA (p = 0.001). Conclusions: The selection of infection markers, as well as the detection methods define the results. Performing two serological and one molecular test is important in order to identify hepatitis B virus carriers and prevent its transmission.

Validation of ELISA with recombinant antigens in serological diagnosis of canine Leishmania infantum infection

BACKGROUND Dogs are the main peridomiciliary reservoir of Leishmania infantum thus the correct diagnosis of infection is essential for the control of the transmission and treatment as well. However, the diagnosis is based on serological assays that are not fully effective. OBJECTIVE We aimed to establish an effective serological assay for the diagnosis of L. infantum infected dogs using Leishmania-derived recombinant antigens. METHODS Leishmania derived rK39-, rK28-, rKR95-based enzyme-linked immunosorbent assay (ELISA) was standardized using symptomatic and asymptomatic L. infantum-infected dogs. Then 2,530 samples from inquiry in endemic areas for VL were evaluated and the results compared with recommended assays by the Brazilian Ministry of Health (MH algorithm). Further samples from a cohort of 30 dogs were searched. FINDINGS For rK39-, rK28- and rKR95-ELISA the sensitivity was around 97% and specificity 100%. The positivity of these three ELISA in the inquiry samples was 27-28%, around 10% higher than the assays currently in use. When cohort samples were searched, we observed likely false-negative results (> 65%) with supposedly negative samples that turned positive six months later with the assays in use (MH algorithm). MAIN CONCLUSIONS For the diagnosis of L. infantum-infected dogs, rK39-based ELISA showed better diagnostic performance than other assays in use in Brazil and worldwide.

Indirect ELISA (iELISA) standardization for the diagnosis of bovine enzootic leukosis / Padronização de um ELISA indireto (iELISA) para diagnóstico da leucose enzoótica bovina

Enzootic bovine leukosis (EBL) is an infectious disease caused by bovine leukemia virus (BLV) that affects cattle worldwide. Agar gel immunodiffusion (AGID) was the reference test for EBL diagnosis for many years, but enzyme-linked immunosorbent assay (ELISA) showed higher sensitivity, was faster to perform, and resulted in an objective reading. However, the importation of ELISA kits is lengthy and expensive, and currently, no AGID kits are available in Brazil. The aim of this work was to standardize an indirect ELISA (iELISA) for EBL diagnosis using BLV antigens produced in Tadarida brasiliensis lung (Tb1Lu) cells, which are Bovine viral diarrhea virus (BVDV) free, unlike fetal lamb kidney (FLK) cells, currently used for this purpose. Following standardization, iELISA results were compared with those obtained by AGID and the commercial Chekit Leucose-Serum ELISA. Compared to AGID, iELISA had 94,44% sensitivity, 75.68% specificity, 79.10% positive predictive value (PPV) and 93.30% negative predictive value (NPV), with 84% concordance and a Kappa index of 0.699. Compared to the Chekit Leucose-Serum ELISA, iELISA showed 92.60% sensitivity, 87.09% specificity, 90.27% PPV and 90,00% NPV, with 90.27% concordance and a Kappa index of 0.801. Taking into account the high agreement with the traditional tests and the absence of non-specific reactions with BVDV, the developed assay could be used as diagnostic method to control EBL in Brazil.(AU)

A leucose enzoótica bovina (LEB) é uma doença infecciosa natural dos bovinos com distribuição mundial causada pelo "bovine leukemia virus" (BLV). A imunodifusão em gel de ágar (IDGA) foi considerada por muitos anos o teste de eleição, porém ensaios imunoenzimáticos (ELISA) apresentam sensibilidade mais elevada e leitura mais rápida e objetiva. No entanto, a importação de kits de ELISA é um processo dispendioso e demorado, e atualmente não há kits de IDGA comercialmente disponíveis no Brasil. Desta forma, o objetivo deste trabalho foi padronizar um ELISA indireto (iELISA) para diagnóstico da LEB utilizando antígenos produzidos a partir do cultivo do BLV em linhagem celular Tadarida brasiliensis "lung" (Tb1Lu) livre de "bovine viral diarrhea virus" (BVDV), diferentemente do que acontece com as linhagens "fetal lamb kidney" (FLK) atualmente utilizadas na produção desses antígenos para uso em ensaios sorológicos. Após a padronização do iELISA, os resultados foram comparados com aqueles obtidos por IDGA e pelo ELISA comercial "Chekit Leucose-Serum". Comparado ao IDGA, o iELISA apresentou 94,44% de sensibilidade, 75,68% de especificidade, valor preditivo positivo (VPP) de 79,1% e valor preditivo negativo (VPN) de 93,3%, com concordância entre os testes de 84% e o índice Kappa 0,699. Quando comparado ao ELISA "Chekit Leucose-Serum", o iELISA apresentou sensibilidade de 92,6%, especificidade de 87,09%, VPP de 90,27% e VPN de 90%, com concordância de 90,27% e o índice Kappa 0,801. Portanto, devido à alta concordância com os testes tradicionais e ausência da ocorrência de reações inespecíficas com BVDV, o ensaio desenvolvido pode ser utilizado como ferramenta diagnóstica para o controle da LEB no Brasil.(AU)

Detección de trazas de soja y de leche en productos libres de gluten: desarrollo de dos enzimoinmunoensayos competitivos / Detection of traces of soy and milk in gluten-free products: development of two competitive enzyme immunoassays / Detecção de vestígios de soja e leite em produtos livres de glúten: desenvolvimento de dois enzimoimunoensaios competitivos

Resumen El objetivo del presente trabajo fue el desarrollo de dos enzimoinmunoensayos competitivos (EIC) para la detección de trazas de soja y de leche en productos libres de gluten. Como anticuerpos primarios se utilizaron antisueros policlonales de conejo específicos contra proteínas de soja o de leche. Se determinaron las concentraciones óptimas de antígenos a inmovilizar en la placa y las concentraciones de anticuerpos primarios a utilizar en la competencia. Las curvas de calibración se ajustaron utilizando concentraciones crecientes de un extracto de producto de soja y de un extracto de leche descremada en polvo. El producto de soja y la leche descremada se extrajeron con buffer Tris-HCl 0,0625 M con dodecilsulfato de sodio al 3% y sulfito de sodio 0,1 M al 2%. Se evaluaron los parámetros de validación: linealidad, límites de detección y de cuantificación, recuperación y precisión en el día y entre días, los cuales resultaron adecuados. Se analizaron 9 productos libres de gluten con los EIC desarrollados y con kits de ELISA comerciales. Ambos EIC se comportaron de manera similar con respecto a los kits comerciales. Los EIC permitieron confirmar la presencia de leche en las muestras que la declaraban. En algunas muestras que no declaraban ni leche ni soja, ambos EIC detectaron su presencia (resultados confirmados con los kits comerciales). Los EIC desarrollados poseen menor costo que los kits y, por lo tanto, éstos podrían utilizarse como métodos de screening. Cuando esta metodología resulte negativa, debe confirmarse con un método más sensible (comercial) para garantizar la ausencia de proteínas de soja o de leche.

Abstract The aim of this study was to develop two competitive enzyme immunoassays (CEI) to detect the presence of traces of soy and milk in gluten-free products. Specific rabbit polyclonal antiserums against soy protein and other against elemilk protein were used as primary antibodies. Optimal antigen concentrations to be immobilized on the plate and primary antibody concentrations to be used in competition were determined. The calibration curves were fitted using increasing concentrations of an extract of soy product and of defatted milk powder. The soy product and the defatted milk were extracted with Tris-HCl buffer 0,0625 M with 3% sodium dodecyl sulfate and 2% sodium sulfite 0.1 M. The validation parameters were evaluated: linearity, limit of detection and quantification, recovery and precision on the day and in between days. They were appropriate. Nine commercial samples of gluten-free products were analyzed with these developed CEI and commercial ELISA kits. It was observed that both CEI behaved similarly with respect to the commercial kits. The enzyme immunoassays confirmed the presence of milk in samples that declared it. In some samples that did not declare the presence of milk or soy, both enzyme immunoassays detected their presence -these results were confirmed using commercial kits. The developed CEI have a lower cost than the commercial kits, so these could be used as screening methods. When this methodology is negative, it should be confirmed with a more sensitive (commercial) method to ensure the absence of soy or milk protein.

Resumo O objetivo do presente trabalho foi o desenvolvimento de dois enzimoimunoensaios competitivos (EIC), para a detecção de vestígios de soja e leite em produtos livres de glúten. Antissoros policlonais de coelho específicos contra proteínas de soja ou de leite foram utilizados como anticorpos primários. Foram determinadas as concentrações ótimas de antígenos a serem imobilizados na placa e as concentrações de anticorpos primários a serem utilizadas na competição. As curvas de calibração foram ajustadas usando concentrações crescentes de um extrato de produto de soja e de um extrato de leite em pó desnatado. O produto de soja e o leite desnatado foram extraídos com tampão Tris-HCl 0,0625 M com dodecil sulfato de sódio a 3% e sulfito de sódio 0,1 M a 2%. Os parâmetros de validação foram avaliados: linearidade, limite de detecção e quantificação, recuperação e precisão no dia e entre os dias, os quais resultaram adequados. Nove produtos livres de glúten foram analisados com os EIC desenvolvidos e com kits de ELISA comerciais. Os dois EICs se comportaram de maneira semelhante em relação aos kits comerciais. Os EIC permitiram confirmar a presença de leite nas amostras que o declararam. Em algumas amostras que declaravam nem leite nem soja, ambos os EIC detectaram sua presença (resultados confirmados usando kits comerciais). Os EIC desenvolvidos têm um custo menor que os kits, portanto, eles poderiam ser utilizados como métodos de triagem. Quando esta metodologia é negativa, deve ser confirmada com um método mais sensível (comercial) para garantir a ausência de proteínasda soja ou do leite.