RESUMEN
Gonadal dysgenesis and heterosexual conditions are often associated with sex chromosome abnormalities. In this study we report on 2 cases of abnormal sex development involving numerical sex chromosome aberrations in both horse and sheep. A 17-month-old Standardbred filly was sent to an equine fertility centre as an embryo donor due to its reduced size, being much smaller than a racehorse filly of the same age, which excluded it from an athletic career. External genitalia were clinically normal but manual palpation of the reproductive tract showed the presence of a small underdeveloped uterus and ovaries, as confirmed by ultrasonographic examination. Cytogenetic investigation by CBA-banding revealed an abnormal karyotype with X chromosome monosomy (2n = 63,X). A 18-month-old ewe showed distinct heterosexual traits with presence of a vulva (with enlarged clitoris), well-developed abdominal testes and mammary glands. Internal sex adducts were atrophic as seen after mating. Cytogenetic analysis revealed the presence of XX/XY mosaicism.
Asunto(s)
Trastornos del Desarrollo Sexual/veterinaria , Caballos/anomalías , Caballos/genética , Aberraciones Cromosómicas Sexuales , Ovinos/anomalías , Ovinos/genética , Animales , Bandeo Cromosómico , Trastornos del Desarrollo Sexual/genética , Femenino , Masculino , Metafase , Conducta Sexual AnimalRESUMEN
In 1970, all final year medical students at the University of Ottawa were required to complete a four-week clerkship in family medicine. The original evaluation system being used consisted of an ongoing assessment by the students' preceptor and a terminal test. This method was unsatisfactory, resulting in four new criteria for the terminal test being established: (1) that it be objective, reproducible, and reliable; (2) that it assess attitudes toward the patient; (3) that it be flexible and not rigidly structured; and (4) that it simulate actual family practice as closely as possible. A new preceptor's evaluation form was also developed. With annual assessment of the evaluation method since 1973, numberous modifications have been introduced to meet the criteria originally sought. Use of a mark sense data entry system and packaged analysis programs have facilitated ongoing evaluation of the system. Currently the preceptor's evaluation form meets both educational and assessment requirements, and the terminal tests meet the criteria developed in 1971.