Unusual ovarian activity in a mare preceding the development of an ovarian granulosa cell tumour

An 8-year-old mare, with a foal at foot, was inseminated on foal heat with frozen semen, with the resultant pregnancy lost between days 34 and 41. The right ovary developed a large anovulatory follicle that was non-responsive to multiple doses of ovulating agents. The follicle eventually appeared to luteinise, although plasma progesterone concentrations did not reflect this. Another follicle developed, responded to GnRH and resulted in a pregnancy from frozen semen that went to term with a healthy foal. When the mare was examined after foaling, the structure on the right ovary appeared to be a granulosa cell tumour; the left ovary was smaller than normal and non-functional. Surgical removal of the right ovary before increasing photoperiod resulted in a return to function of the left ovary and a pregnancy to frozen semen on the second cycle following removal. Figures showing concentrations of inhibin, progesterone, androstenedione, oestradiol and testosterone are presented for this entire period. Unusual ovarian activity in the mare might be a prelude to the development of a granulosa cell tumour.     

Expression of Genes Associated with Apoptosis in the Porcine Corpus Luteum During the Oestrous Cycle

The corpus luteum (CL) of the pig lacks luteolytic sensitivity (LS) to prostaglandin (PG) F‐2α until after day 12 of the oestrous cycle, but the mechanisms underlying this phenomenon are poorly understood. As luteolysis involves apoptosis, we hypothesized that critical apoptotic proteins may be deficient in CLs that lack LS. The specific aim of these studies was to examine mRNA expression and protein levels of apoptosis genes/proteins (BAX/Bax, BCLX/Bcl‐x, CASP3/Caspase‐3, CASP8/Caspase‐8, NFΚB1/NFκB, TP53/p53) in porcine CLs collected at different stages of the oestrous cycle. CLs were collected surgically, mRNA and protein extracted, and expression/levels analyzed by semi‐quantitative (SQ) PCR and Western blots, respectively. At the mRNA expression level, only BAX (maximal on day 4) and TP53 (maximal on day 7) showed significant variations during the oestrous cycle. At the protein level, only Bcl‐x and Caspase‐3 showed significant changes during the cycle; Bcl‐x decreased on day 13 and Caspase‐3 increased on day 13. It is concluded that apoptosis‐associated proteins (i.e. Bcl‐x and Caspase 3) may play a critical role in luteolytic sensitivity in the pig.     

IgG subclass responses in a longitudinal study of canine visceral leishmaniasis

Visceral leishmaniasis (VL), caused by Leishmania infantum, is an important disease of domestic dogs. Here, we present data on the IgG subclass antibody response to crude L. infantum antigen in a cohort of naturally infected Brazilian dogs. Specific IgG1-IgG4 responses could be detected in 98, 58, 70 and 82%, respectively of 57 dogs that were seropositive for specific IgG. Levels of all IgG subclasses were strongly inter-correlated. Levels of all IgG subclasses increased at the time of seroconversion, before reaching a plateau after several months. Levels of all IgG subclasses were higher in sick dogs than healthy dogs, and levels of all except IgG2 were higher in parasite-positive (by PCR) than parasite-negative dogs. However, levels of IgG2 relative to IgG1 were lower in sick or parasite-positive dogs compared to healthy or parasite-negative infected dogs. In contrast to previous studies, the results suggest that canine VL is associated with upregulation of specific antibody of all IgG subclasses, particularly IgG1, IgG3 and IgG4.     

Selected Ovarian Ultrasonographic Characteristics During Vernal Transition are Useful to Estimate Time of First Ovulation of the Year

It is important to get mares pregnant as early as possible after vernal transition and thus, identification signs of impending 1st ovulation of the year are warranted. To identify clinical indicators of an approaching first ovulation of the year, mares were teased with a stallion for oestrous detection starting January 3 and subjected to ultrasonographic examination. Day of first appearance of uterus oedema, follicular wall invagination, intrafollicular echogenicity, double contour of the follicle wall, increase in granulosa thickness, follicular wall hyperechogenicity and appearance of pear‐shaped follicles was registered, as well as follicle diameter and number. Seventy per cent of the mares had anovulatory oestrous periods of 4.6 ± 3.6 days, with an interoestroual interval of 12.5 ± 12.2 days. Number of anovulatory oestruses per mare was 2.4 ± 2.3. Uterine oedema occurred in 77% of the mares, 32.4 ± 25.6 days before ovulation. Invagination of the follicular wall appeared in 44.4% of the animals, 24.5 ± 18.4 days before ovulation. Intrafollicular echogenicity was seen in all mares and double contour of the follicle was seen in 77% of the animals. Both last two characteristics appeared 1–72 days before ovulation. Increased thickness of the granulosa occurred in 66% of the mares, 1–19 days before ovulation. Pear‐shaped follicles and follicular wall hyperechogenicity were detected 3 or less days before the first ovulation, in 44.4% and 55.5% of mares, respectively. Mean number of follicles >15 mm decreased at least 16 days before ovulation. We concluded that no isolated characteristic was a reliable indicator. However, increase in granulosa thickness, formation of a pear‐shaped follicle and follicular wall hyperechogenicity, associated with the reduction of the number of follicles >15 mm in diameter to <3, resulted in the first ovulation of the year in 44–67% of the transitional mares, 1–19 days after the characteristics appeared.