Bilateral Dentate Gyrus Structural Alterations in a Cat Associated With Hippocampal Sclerosis and Intraventricular Meningioma.

A 13-year-old cat had a history of seizures for 3 years that resembled temporal lobe epilepsy. Histologic examination of the brain revealed bilateral hippocampal alterations, including hypergyration and broadening of the dentate gyrus associated with hippocampal sclerosis and an intraventricular meningioma near the hippocampal region. The findings in the dentate gyrus were interpreted as a congenital malformation; however, it could not be ruled out that the alterations were induced by the seizures. Similar changes of the dentate gyrus have not been previously described in cats.

Suppression of ovarian progesterone production in dairy cows using an implant of GnRH-agonist (deslorelin) for the purpose of evaluating progesterone metabolism [corrected].

OBJECTIVE: To evaluate the potential of an implant of a GnRH-agonist (deslorelin) to create a progesterone free animal suitable for studying progesterone (P4) metabolism in intact cows by measuring blood P4 and faecal P4 metabolites. METHODS: Experiment 1: Eighteen non-lactating cycling Holstein-Friesian cows, 4 to 7 years old, were allocated to one of three groups to study plasma P4 concentrations preceding an intravaginal insert. These groups comprised: i) a deslorelin group (GnRH-agonist implanted); ii) a PGF group receiving two injections of prostaglandin (PGF2alpha) 12 days apart; and, iii) an ovariectomised (OVX) group. An intravaginal device (CIDR) was inserted into the vagina of each animal and left in place for 11 days. Plasma P4 concentrations were measured during the study period. Experiment 2: Twelve non-lactating cycling Holstein-Friesian cows, 4 to 7 years old, were allocated to two groups: i) a deslorelin group (GnRH-agonist implanted); and ii) an ovariectomised group. Plasma P4 and faecal P4 metabolites (20-oxo-pregnanes, 20alpha-OH and 20beta-OH) were monitored for a period of 5 weeks. RESULTS: Experiment 1: Average plasma P4 concentration did not differ between the three groups (1.28, 1.43 and 1.55 ng/mL for deslorelin, OVX and PGF cows, respectively, P = 0.8) during the period of supplementation. Experiment 2: There was no difference in plasma P4 (mean plasma P4 < 0.02 ng/mL, P = 0.9) and faecal P4 metabolites between deslorelin and OVX cows 2 weeks after the implantation (P = 0.7). CONCLUSIONS: These data showed that a GnRH-agonist (deslorelin) implant may be used as an alternative to ovariectomy to create a progesterone free animal suitable for studying the metabolism of administered P4.

Cell proliferation in the growing human heart: MIB-1 immunostaining in preterm and term infants at autopsy.

Few studies of human cardiac myocyte proliferation in the perinatal period have been conducted. We measured the proliferative activity of left ventricular myocytes in tissue obtained at autopsy in three surgically induced abortuses, 20 preterm infants with gestational ages ranging from 12 to 35 weeks, eight term infants with ages ranging from 1 day to 11 months, and five adults. The preterm infants lived less than 24 h, thus simulating the in utero condition of developing hearts. To assess the proliferative activity of the myocytes, we measured immunoreactivity using the monoclonal antibody MIB-1 against the recombinant Ki-67 nuclear antigen. Immunostained sections were examined by light microscopy, and the results expressed as a staining index (SI) of 0-3, according to the percentage of positively stained myocyte nuclei. Myocyte proliferative activity remained constant during the early preterm period and decreased in the late preterm and early postterm periods. Adult myocytes, regardless of cardiac weight, did not reveal proliferative activity as assessed by immunostaining. This proliferation pattern is consistent with findings in most earlier studies in animal models.