Optimization of the Equine-Sperm Freeze Test in Purebred Spanish Horses by Incorporating Colloidal Centrifugation.

The Purebred Spanish Horse, according to our clinical experience, is characterized by having a high number of stallions that do not meet the international commercial recommendations for equine-sperm cryopreservation. This means that artificial insemination with frozen semen from these stallions is less widespread than in other breeds. In this study, we investigated if the incorporation of single-layer colloidal centrifugation prior to cryopreservation in clinical conditions could increase the number of ejaculates of Purebred Spanish stallions suitable for this processing, observing the influence of centrifugation and freezing extender protocol on post-thawed sperm motility. Using colloidal centrifugation, the percentage of ejaculates available to be frozen was increased from 35% (6/17) to 71% (12/17), doubling the number of samples that could have been subjected to cryopreservation. We only found significant differences in linearity (LIN) and lateral head displacement (ALH) after 5 min of incubation at 37 °C between colloidal and simple centrifugation processing techniques. No significant differences were found between the two different colloidal protocols in any of the variables considered. Colloidal centrifugation allowed us to obtain, from worse fresh-quality ejaculates, thawed sperm doses with similar quality to that of good-quality ejaculates. BotuCrio® produced, in general, higher motility parameters and its characteristics than the other extenders analyzed, with significant differences found in comparison to Inra-Freeze® and Lac-Edta in both total (MOT) and progressive motility (PMOT) when using colloidal centrifugation and only in PMOT when applying simple centrifugation. Colloidal centrifugation optimized the efficiency of cryopreservation, as it allowed us to increase the number of ejaculates of Purebred Spanish Horses suitable to be frozen. Including these semen processing techniques in the freeze test could help to optimize equine-sperm cryopreservation protocols, especially when dealing with individuals or breeds for which initially low sperm quality prevents or limits their inclusion in sperm cryopreservation programs.

Temporal analysis of the interference caused by paratuberculosis vaccination on the tuberculosis diagnostic tests in goats.

Vaccination against paratuberculosis (PTB) in goats is a cost-effective control strategy, and is also effective as regards preventing the onset of clinical cases. However, it causes interference in the diagnostic tests used in the control of tuberculosis (TB). A group of 99 goats from a herd with no history of TB or PTB infection was vaccinated against PTB at seven months of age. They then underwent consecutive intradermal tests [single (SIT) and comparative (CIT) intradermal tuberculin tests), interferon-gamma release assays (IGRA) and two serological tests (p22_CE and DR-ELISA) every three months, until the interference disappeared. When using the SIT test, a variable number of positive reactors were observed at 3 months (T3; 32.3%, 95% CI 23.9-42.1), 6 months (T6; 11.5%, 95% CI 6.5-19.4), 9 months (T9; 6.4%, 95% CI 3.0-13.2) and 12 months (T12; 0%, 95% CI 0-4.0) post-vaccination. In contrast, the CIT test had a specificity (Sp) of 100% (95%, CI 96.0-100, regardless of the time post-vaccination. The IGRA also obtained high Sp values throughout the study period. No significant interference in the serological tests was recorded at T3 [p22_CE, Sp = 96% (95% CI 90.1-98.4) and DR-ELISA, Sp = 98% (95% CI 92.9-99.4)], although an increase in antibody titers was observed in the following herd testing events. In conclusion, the use of the SIT test causes the onset of false-positive reactors if applied before 12 months post-vaccination in a TB-free/PTB-vaccinated herd. Nevertheless, the CIT test and IGRA obtained high Sp values under these epidemiological circumstances. The serological tests were also highly specific in the case of PTB-vaccinated goats, although their Sp decreased significantly after several intradermal tests.

Cribado combinado del síndrome de Down: validación del riesgo estimado por Fetaltest / Combined screening of Down syndrome: validation of the risk estimated by Fetaltest

Objetivo: Validar empíricamente el riesgo de síndrome de Down estimado por Fetaltest usando marcadores bioquímicos del primer trimestre (la proteína A asociada al embarazo [PAPP-A] y subunidad beta libre de la gonadotropina coriónica humana [HCG]) y translucencia nucal (TN). Material y métodos: Estudio retrospectivo de los 15.009 cribados combinados del primer trimestre, incluidos en la base de datos mantenida prospectivamente por el estudio multicéntrico Fetaltest, y finalizados antes de 31 de diciembre de 2007. El estudio incluye 39 casos de síndrome de Down detectados pre o posnatalmente y usó un método de análisis previamente establecido. Resultados: La correlación entre el riesgo predicho y la prevalencia observada de síndrome de Down fue muy alta (r = 0,999967). Conclusiones: El riesgo estimado por el sistema de cálculo de Fetaltest concuerda muy fielmente con la prevalencia de síndrome de Down observada, por lo que este sistema de cálculo es válido y puede usarse con tranquilidad en la atención de gestantes de nuestro entorno (AU)

Objective: To validate empirically the risk for Down syndrome estimated by Fetaltest using biochemical markers in the first trimester (PAPP-A and free beta subunit of hCG) and nuchal translucency. Material and methods: We performed a retrospective study of the data from 15,009 pregnant women screened for Down Syndrome in the first trimester, included in the database prospectively maintained by the Fetaltest multicenter study, and completed before December 31, 2007. The study included 39 cases of Down syndrome detected either prenatally or postnatally, and used a previously established analysis method. Results: The correlation between predicted risk and the observed prevalence of Down syndrome was very high (r = 0.999967). Conclusions: The risk estimated by Fetaltest agrees closely with the observed prevalence of Down syndrome. Therefore, this calculation system is valid and can be used with confidence when counseling pregnant women in our environment (AU)