Evaluation of the effect of laboratory methods on semen analysis and breeding soundness examination (BSE) classification in stallions.

The stallion Breeding Soundness Examination (BSE), as proposed by the Society for Theriogenology, recommends that a stallion produce a minimum of one billion progressively motile, morphologically normal sperm (PMMNS) in the second of two ejaculates collected 1 h apart to be classified as a Satisfactory Prospective Breeder. With this in mind, the first objective of this study was to determine if the classification outcome of the traditional BSE differs depending on the methods used to evaluate sperm motility, morphology and concentration. We hypothesized that application of Computer Assisted Sperm Motion Analysis (CASA) and Differential Interference Contrast (DIC) microscopy to stallion semen evaluation would yield a more conservative estimate of the number of PMMNS. If this hypothesis is correct, then the use of CASA and DIC microscopy for semen evaluation would result in significantly fewer stallions meeting the historical standards for classification as a Satisfactory Prospective Breeder. Additionally, we determined whether the use of these modern technologies resulted in more accurate prediction of the actual fertility of a stallion compared to the use of more traditional technologies. Our results support the hypothesis that modern semen analysis techniques (including CASA and DIC microscopy) result in more conservative estimates of the number of PMMNS when compared to standard semen analysis techniques. As a result, the choice of methods used for semen analysis may impact the outcome of the traditional BSE. However, none of the methodologies used in this study reliably predicted different levels of fertility among this group of moderately to highly fertile stallions within the context of the traditional BSE. Additionally, the only individual semen measure that was significantly correlated with fertility was the percentage of morphologically normal sperm as determined using DIC microscopy. These results caution against strict use of the traditional 'cutoff' of 1 billion PMMNS for classification of breeding potential, particularly when attempting to differentiate between moderately and highly fertile stallions and regardless of the laboratory methods employed for semen analysis.

Pilocytic astrocytoma in a child with Noonan syndrome.

Noonan syndrome (NS; MIM 163950) is an autosomal dominant dysmorphic syndrome characterized by distinct facial features, cardiac anomalies, short stature, and motor delay. Activating mutations in PTPN11, encoding the protein tyrosine phosphatase SHP2, are associated with about 50% of cases. Mutations in other genes in the RAS/mitogen-activated protein kinase signaling pathway are responsible for many of the remainder of cases. While mutations in this pathway are found in a variety of malignancies, including solid tumors, there are few reports of solid tumors in individuals with NS. We report here a patient with PTPN11 mutation-associated NS and a pilocytic astrocytoma.