Sudden unexpected death in epilepsy (SUDEP) is a significant cause of premature seizure-related death. An association between SUDEP and cardiac remodeling has been suggested. However, whether SUDEP is a direct consequence of acute or recurrent seizures is unsettled. The purpose of this study was to evaluate the impact of status epilepticus (SE) and chronic seizures on myocardial structure and function. We used the intracortical kainate injection model of temporal lobe epilepsy to elicit SE and chronic epilepsy in mice. In total, 24 C57/BL6 mice (13 kainate, 11 sham) were studied 2 and 30 days post-injection. Cardiac structure and function were investigated in-vivo with a 9.4 T MRI, electrocardiography (ECG), echocardiography, and histology [Haematoxylin/Eosin (HE) and Martius Scarlet Blue (MSB)] for staining of collagen proliferation and fibrin accumulation. In conclusion, we did not detect any significant changes in cardiac structure and function neither in mice 2 days nor 30 days post-injection.
The ability of persistent organic pollutants (POPs) with endocrine disrupting properties to interfere with the developing reproductive system is of increasing concern. POPs are transferred from dams to offspring and the high sensitivity of neonates to endocrine disturbances may be caused by underdeveloped systems of metabolism and excretion. The present study aimed to characterize the effect of in utero and lactational exposure to a human relevant mixture of POPs on the female mammary gland, ovarian folliculogenesis and liver function in CD-1 offspring mice. Dams were exposed to the mixture through the diet at Control, Low or High doses (representing 0x, 5000x and 100 000x human estimated daily intake levels, respectively) from weaning and throughout mating, gestation, and lactation. Perinatally exposed female offspring exhibited altered mammary gland development and a suppressed ovarian follicle maturation. Increased hepatic cytochrome P450 enzymatic activities indirectly indicated activation of nuclear receptors and potential generation of reactive products. Hepatocellular hypertrophy was observed from weaning until 30 weeks of age and could potentially lead to hepatotoxicity. Further studies should investigate the effects of human relevant mixtures of POPs on several hormones combined with female reproductive ability and liver function.
Lymphocytes of intestinal epithelia were examined in lambs experimentally infected with coccidia. Fourteen conventional, coccidia-free 3-week-old lambs of the Dala breed were given either 250,000 (eight lambs in experiment 1) or 100,000 (six lambs in experiment 2) sporulated oocysts of Eimeria ovinoidalis (>99.9% pure) via a stomach tube. Nine lambs (five in experiment 1 and four in experiment 2) of the same age served as uninoculated controls. The infected lambs developed diarrhea and dehydration between days 10 and 13 after infection. Intestinal specimens were collected 10-20 days after inoculation. A heavy multifocal infection of the epithelium comprising schizonts, gamonts, and oocysts resulted, with changes being most pronounced in the large intestine and the terminal part of ileum. Lesions included villous atrophy, villous fusions, and crypt hyperplasia. Computer-assisted morphometric analysis was applied to immunoperoxidase-stained sections for quantification of intraepithelial T cell subsets and included the distal jejunum of lambs of experiment 1. A significant increase in the epithelial area of the distal jejunum occupied by CD8+ lymphocytes was found in the infected lambs as compared with uninfected controls (18.3% versus 3.7%). The increased presence of CD8+ cells may be of significance in the intestinal immune response to ovine coccidiosis. A moderate, overall increase was also found for the γδ lymphocytes in the jejunal epithelium. Examination of the ileum of infected lambs of both experiments showed a scarcity of γδ cells (0.4% of epithelial area) in stretches of epithelium infected by coccida as compared with adjacent noninfected epithelium (4.0% of epithelial area). The significance of this negative association between γδ T cells and infected epithelial cells in ovine coccidiosis is unknown.
A total of 14 lambs were experimentally infected with Eimeria ovinoidalis in two separate experiments in two consecutive years. Nine lambs served as uninoculated controls. Material was collected from the ileum 2 weeks after infection in eight lambs and 3 weeks after infection in six lambs. Lambs examined 2 weeks after infection had normal follicles. After three weeks, the follicle-associated epithelium covering the lymphoid follicles of the ileal Peyer's patches showed fusions with adjacent absorptive epithelium, focal hyperplasia, and occasionally necrosis. Macrogametes, microgamonts, and oocysts were often found in the follicle-associated epithelium and the dome region. Various degrees of lymphocyte depletion were present in the ileal lymphoid follicles in all six infected lambs 3 weeks after infection, and four lambs had decreased follicle size. Reduced staining for leukocyte common antigen (CD45), B-cell markers, and the proliferation marker Ki-67 was present in these lambs. Application of the terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling method for apoptotic cells revealed decreased staining in the ileal lymphoid follicles 3 weeks after infection. A marker of follicular dendritic cells, 5'- nucleotidase, showed increased reactivity, probably due to condensation of reticular cells following loss of follicle lymphocytes. Reduced staining for carbonic anhydrase in the follicle-associated epithelium and the domes was present in all six lambs examined 3 weeks after infection, indicating decreased production of carbonic anhydrase-reactive 50-nm particles and a decreased lymphoproliferative stimulus. In conclusion, the present study shows that severe E. ovinoidalis infection in lambs causes lesions of the follicle-associated epithelium and may result in lymphocyte depletion and atrophy of the ileal Peyer's patch follicles.
Exposure of the developing foetus to some environmental chemicals can have detrimental effects on human and animal health, in particular, reproductive function. These endocrine disrupting compounds (EDCs), can act by mimicking endogenous hormones. One such group of chemicals, the polychlorinated biphenyls (PCBs), are well known for their reproductive toxicity. Successful reproductive function is dependant on hypothalamic GnRH release which ultimately controls gonadal function. The gonadotrophic axis is dynamically regulated by a plethora of excitatory and inhibitory inputs, such as the kisspeptin/GPR54 system which has been proposed as an essential gatekeeper of GnRH neuronal function. The aim of this study was to determine whether developmental exposure to environmentally relevant doses of the PCB congeners PCB118 and PCB153 can affect hypothalamic kisspeptin and GPR54 mRNA expression. Pregnant ewes were treated (s.c. injection) with either PCB118 (49 μg/kg body weight/day), PCB153 (98 μg/kg body weight/day) or corn oil 3 times/week throughout gestation. The hypothalami from 8 week old male and female lambs were harvested and frozen. Hypothalami were sliced in an anatomically defined manner into 2 mm thick slices from which punches (2mm) were taken that encompassed tissue from 4 distinct hypothalamic regions: 1) MPOA 2) MPOA/OVLT 3) PVN 4) ARC. mRNA was extracted from the tissue punches, reverse transcribed and expression of ovine kisspeptin and GPR54 mRNA quantified, relative to β actin by Q-PCR. Data were analysed using two-way ANOVA. mRNA expression for both kisspeptin and GPR54 were significantly (P<0.005) lower in the males relative to the females (kisspeptin 78±17 fold, GPR54 11±2 fold) in all hypothalamic regions compared. In female lambs, both kisspeptin and GPR54 mRNA expression were significantly (P<0.05) decreased in PCB118 treated lambs (n=11) relative to the controls (n=11), in all hypothalamic regions tested. These effects of PCB118 exposure were, however, most pronounced in the PVN. In female PCB153 treated animals (n=11) there was no significant effect of treatment on kisspeptin or GPR54 expression. For males, neither kisspeptin nor GPR54 mRNA expression were significantly affected by PCB118 (n=5) or PCB153 treatment (n=8). These results indicate sexually differentiated effects of PCB118 and 153 on kisspeptin and GPR54 gene expression at 8 weeks of age. However, this may reflect an underlying sex difference in kisspeptin and GPR54 gene expression, whereby expression in 8 week old male lambs is low, and thus further suppression is hard to observe. The difference in mRNA expression levels between males and females may reflect different levels of reproductive neuroendocrine maturity at 8 weeks of age, males being closer to puberty than females. In the female, the results clearly demonstrate that developmental exposure to PCBs can negatively affect hypothalamic kisspeptin and GPR54 mRNA expression. Moreover, they indicate that some PCB congeners have greater physiological effects than others, which could reflect different mechanisms of action. Since the kisspeptin/GPR54 system has been shown to play a pivotal role in the control of puberty and reproduction, the observation that the activity of this system is altered following developmental exposure to PCBs, would indicate that this system is a possible target through which EDCs can affect normal reproductive function and fertility. Funded by - Research council of Norway.
