Genome-wide analysis of the Siboney de Cuba cattle breed: genetic characterization and framing with cattle breeds worldwide.

Crossbreeding has been employed to address environmental challenges. One successful example is the Siboney de Cuba, developed in response to economic challenges in the 1960s. The aim of this study was to perform the first genomic characterization of the Siboney de Cuba breed, a successful hybrid breed resulting from the crossbreeding of Cuban Zebu and Holstein, using SNP array chip. For this purpose, 48 Siboney de Cuba cattle samples were collected and genotyped with the GGP Bovine 100k BeadChip, resulting in 83,314 SNPs after quality control. The genetic diversity was investigated using observed and expected heterozygosity, inbreeding coefficient, and minor allele frequency. Runs of homozygosity (ROH) analysis provided insights into molecular inbreeding. Additionally, the study investigated copy number variants (CNV), identifying CNV regions and their distribution. The genetic relationship and population structure of Siboney de Cuba were analyzed in comparison with worldwide cattle populations using ADMIXTURE, multidimensional scaling, and phylogenetic analysis. Six ROH islands containing a total of 50 genes were discovered, some of which were uncharacterized loci. Furthermore, 792 CNV with higher occurrence of genetic material loss were observed. The overall genome coverage for CNV regions was 2.16%. The Siboney de Cuba exhibited a good level of genetic variability with high heterozygosity and low inbreeding when compared with other cattle breeds worldwide. Also, the breed shared genetic similarity to hybrids from America and Bos indicus from Africa and highlighted a moderate level of genetic isolation with some overlaps with Bos taurus from America. The breed showed a complex genetic composition, influenced by historical factors. Overall, findings of the present study contribute to the understanding of genomic structure of Siboney de Cuba cattle breed.

Estudio de patrones de indeterminados al Western blot en el algoritmo cubano de diagnóstico serológico del Virus de Inmunodeficiencia Humana / Study of Western blot indeterminate patterns in the algorithm followed in Cuba for HIV diagnosis

Cada año un número de personas resultan indeterminadas por las pruebas de Western blot y requieren de seguimiento para esclarecer su condición serológica respecto al VIH. Para profundizar en el conocimiento de este grupo, se estudió la respuesta de anticuerpos a las diferentes proteínas virales en el Western blot de 571 personas que resultaron indeterminadas en el algoritmo de confirmación del Laboratorio de Investigaciones del SIDA en Cuba (LISIDA) durante los años 2004 y 2005, también se investigó la evolución serológica de 57 personas que presentaban reactividad solamente contra las proteínas de 53 y/o 55 Kd, pudiendo estar presente además, reactividad contra la proteína de 17Kd. Se observó de forma significativa (p< 0,001) una mayor reactividad a las proteínas de 53 y 55 Kd, de igual forma resultó significativo el porcentaje de personas que negativizaron su patrón de bandas en el Western blot en la evolución serológica. Los resultados coinciden con lo reportado por otros investigadores en estudios similares y justifican la estrategia de seguimiento serológico y epidemiológico en personas con patrones indeterminados al VIH 1 en el Western blot, aún cuando su reactividad sea solamente contra las proteínas de 53 o 55 Kd, además, confirman que el diagnóstico de VIH va más allá de un criterio de interpretación o el valor de la reactividad a una proteína en particular, el éxito está en la conjugación de los resultados del laboratorio con la clínica y la epidemiologia

Every year a number of individuals are interpreted as indeterminate when tested by Western blot, then, a follow up is required to clear up their HIV serological status. To deepen in the study of this group, 571 persons whose Western blot was interpreted as indeterminate in the confirmatory algorithm of the AIDS Research Laboratory in Cuba (LISIDA) during the years 2004 and 2005 were studied for antibody response to the different HIV viral proteins; the serological evolution of 57 persons who only showed reactivity to p53 and/or p55 Kd, with a probable reactivity to p17 Kd protein was also studied. A greater reactivity (p < 0,001) to proteins 53 and 55 Kd was observed, and the percentage of persons who became negative in their Western blot bands pattern during the serological evolution was also significant. The results correlate with those reported by other researchers in similar studies, and justify the strategy of serological and epidemiological follow up in HIV- 1 individuals with Indeterminate Western blot tests, even when its reactivity is only against proteins 53 or 55 Kd, it also confirms the fact that HIV diagnosis is beyond an interpretation criteria or the reactivity value to a particular protein, success lies on the conjugation of clinical and epidemiological laboratory results

Evaluación de la inmovilización de un péptido de gp36 de VIH-2 en membranas de nitrocelulosa / Evaluation of the immobilization of one HIV-2 gp36 peptide in nitrocellulose membrane

Introducción: la inmovilización de antígenos a soportes sólidos se utiliza para el desarrollo de diversos inmunoensayos. Una de las primeras tecnologías desarrolladas fue la adsorción de proteínas por aplicación directa sobre la nitrocelulosa. Objetivo: normalizar la inmovilización de un péptido sintético de la proteína de transmembrana gp36 del VIH-2, a un soporte de nitrocelulosa para fines diagnósticos y evaluar los parámetros de desempeño en un grupo de muestras de sueros con reactividad de interés conocida. Métodos: el péptido se inmovilizó de forma libre, conjugado a la albúmina de suero bovina (BSA) y a la hemocianina de lapa marina (KLH) como proteínas portadoras. Se analizaron los parámetros de inmovilización y se determinó la variante óptima. Con la variante escogida se evaluó la sensibilidad y especificidad diagnóstica frente a paneles de referencia del Laboratorio de Investigaciones del SIDA. La especificidad analítica se evaluó con muestras reactivas a VIH-1 y HTLV-I. Resultados: el análisis de las variantes de péptido inmovilizadas a las membranas de nitrocelulosa, demostró que el péptido gp36-BSA, fue el que logró la mayor diferenciación entre muestras positivas y negativas. Se obtuvo 100 por ciento de sensibilidad y 95,2 por ciento de especificidad diagnóstica, así como 100 por ciento de especificidad analítica. Conclusiones: el péptido gp36-BSA inmovilizado en membranas de nitrocelulosa es eficaz en el diagnóstico serológico del VIH-2, lo cual permitirá considerarlo para su empleo con fines diagnósticos en sistemas que utilicen como fase sólida la nitrocelulosa.

Introduction: antigen immobilization in solid supports is used for the development of several immunoassays. One of the first technologies developed was the protein adsorption by direct application to nitrocellulose. Objective: to standardize the immobilization of a synthetic peptide of the HIV-2 transmembrane protein gp36 to nitrocellulose support for diagnostic purposes and to evaluate the performance parameters in a group of serum samples with recognized interesting reactivity. Methods: the peptide was freely immobilized, conjugated to bovine serum albumin (BSA) and to keyhole limpet hemocyanin (KLH) as carrier proteins. Immobilization parameters were analyzed and then, the optimal immobilization alternative was determined. Using the chosen variant, the diagnostic sensitivity and specificity against reference panels of the AIDS Research Laboratory were evaluated. Analytical specificity was evaluated with reactive samples to HIV-1 and HTLV-I. Results: the analysis of the immobilized peptide variants to nitrocellulose membranes showed that the gp36 peptide-BSA was the one that succeeded in setting the greatest differentiation between positive and negative samples. There were observed 100 percent sensitivity, 95.2 percent diagnostic specificity and 100 percent analytical specificity. Conclusions: the gp36-BSA peptide immobilized on nitrocellulose membranes showed efficacy for the serological diagnosis of HIV-2, which will allow considering this peptide for diagnostic uses in systems with nitrocellulose based solid phase.

Evaluación de la inmovilización de un péptido de gp36 de VIH-2 en membranas de nitrocelulosa / Evaluation of the immobilization of one HIV-2 gp36 peptide in nitrocellulose membrane

Introducción: la inmovilización de antígenos a soportes sólidos se utiliza para el desarrollo de diversos inmunoensayos. Una de las primeras tecnologías desarrolladas fue la adsorción de proteínas por aplicación directa sobre la nitrocelulosa. Objetivo: normalizar la inmovilización de un péptido sintético de la proteína de transmembrana gp36 del VIH-2, a un soporte de nitrocelulosa para fines diagnósticos y evaluar los parámetros de desempeño en un grupo de muestras de sueros con reactividad de interés conocida. Métodos: el péptido se inmovilizó de forma libre, conjugado a la albúmina de suero bovina (BSA) y a la hemocianina de lapa marina (KLH) como proteínas portadoras. Se analizaron los parámetros de inmovilización y se determinó la variante óptima. Con la variante escogida se evaluó la sensibilidad y especificidad diagnóstica frente a paneles de referencia del Laboratorio de Investigaciones del SIDA. La especificidad analítica se evaluó con muestras reactivas a VIH-1 y HTLV-I. Resultados: el análisis de las variantes de péptido inmovilizadas a las membranas de nitrocelulosa, demostró que el péptido gp36-BSA, fue el que logró la mayor diferenciación entre muestras positivas y negativas. Se obtuvo 100 por ciento de sensibilidad y 95,2 por ciento de especificidad diagnóstica, así como 100 por ciento de especificidad analítica. Conclusiones: el péptido gp36-BSA inmovilizado en membranas de nitrocelulosa es eficaz en el diagnóstico serológico del VIH-2, lo cual permitirá considerarlo para su empleo con fines diagnósticos en sistemas que utilicen como fase sólida la nitrocelulosa(AU)

Introduction: antigen immobilization in solid supports is used for the development of several immunoassays. One of the first technologies developed was the protein adsorption by direct application to nitrocellulose. Objective: to standardize the immobilization of a synthetic peptide of the HIV-2 transmembrane protein gp36 to nitrocellulose support for diagnostic purposes and to evaluate the performance parameters in a group of serum samples with recognized interesting reactivity. Methods: the peptide was freely immobilized, conjugated to bovine serum albumin (BSA) and to keyhole limpet hemocyanin (KLH) as carrier proteins. Immobilization parameters were analyzed and then, the optimal immobilization alternative was determined. Using the chosen variant, the diagnostic sensitivity and specificity against reference panels of the AIDS Research Laboratory were evaluated. Analytical specificity was evaluated with reactive samples to HIV-1 and HTLV-I. Results: the analysis of the immobilized peptide variants to nitrocellulose membranes showed that the gp36 peptide-BSA was the one that succeeded in setting the greatest differentiation between positive and negative samples. There were observed 100 percent sensitivity, 95.2 percent diagnostic specificity and 100 percent analytical specificity. Conclusions: the gp36-BSA peptide immobilized on nitrocellulose membranes showed efficacy for the serological diagnosis of HIV-2, which will allow considering this peptide for diagnostic uses in systems with nitrocellulose based solid phase(AU)

[Evaluation of the immobilization of one HIV-2 gp36 peptide in nitrocellulose membrane]. / Evaluación de la inmovilización de un péptido de gp36 de VIH-2 en membranas de nitrocelulosa.

INTRODUCTION: antigen immobilization in solid supports is used for the development of several immunoassays. One of the first technologies developed was the protein adsorption by direct application to nitrocellulose. OBJECTIVE: to standardize the immobilization of a synthetic peptide of the HIV-2 transmembrane protein gp36 to nitrocellulose support for diagnostic purposes and to evaluate the performance parameters in a group of serum samples with recognized interesting reactivity. METHODS: the peptide was freely immobilized, conjugated to bovine serum albumin (BSA) and to keyhole limpet hemocyanin (KLH) as carrier proteins. Immobilization parameters were analyzed and then, the optimal immobilization alternative was determined. Using the chosen variant, the diagnostic sensitivity and specificity against reference panels of the AIDS Research Laboratory were evaluated. Analytical specificity was evaluated with reactive samples to HIV-1 and HTLV-1. RESULTS: the analysis of the immobilized peptide variants to nitrocellulose membranes showed that the gp36 peptide-BSA was the one that succeeded in setting the greatest differentiation between positive and negative samples. There were observed 100 % sensitivity, 95.2 % diagnostic specificity and 100 % analytical specificity. CONCLUSIONS: the gp36-BSA peptide immobilized on nitrocellulose membranes showed efficacy for the serological diagnosis of HIV-2, which will allow considering this peptide for diagnostic uses in systems with nitrocellulose -based solid phase.