Effects of prenatal stress on corticosteroid receptors and monoamine concentrations in limbic areas of suckling piglets (Sus scrofa) at different ages

The present study was conducted in order to reveal the effects of prenatal stress on the central stress regulation in domestic pigs by measuring changes in corticosteroid receptor binding and monoamine concentrations in different limbic brain regions. Pregnant sows were subjected to a restraint stress for 5 min daily during the last 5 weeks of gestation. Maternal stress resulted in a significantly higher number of glucocorticoid receptors in the hippocampus, but decreased glucocorticoid receptors in the hypothalamus of the offspring at the first postnatal day. No alterations of hippocampal mineralocorticoid receptors were found. There was also no significant effect of prenatal stress on the brain monoamine concentrations. Prenatally stressed piglets showed lower basal plasma cortisol and increased corticosteroid binding globulin concentrations at the third postnatal day indicating decreased free cortisol concentrations after birth. Morbidity and mortality during the suckling period were significantly increased in prenatally stressed litters, as shown by a higher frequency of diseased and died piglets per litter. In conclusion, the results indicate that in pigs restraint stress during late gestation affects the ontogeny of the foetal neuroendocrine feedback system with consequences for the regulation of the hypothalamo-pituitary-adrenal function and the vitality of the offspring.     

Effect of intramammary infusion of beta-1,3-glucan or interleukin-2 on leukocyte subpopulations in mammary glands of sheep.

OBJECTIVE: To investigate effects of intramammary infusion of beta-1,3-glucan or recombinant ovine interleukin-2 (rOvIL-2) on blood and mammary leukocyte subpopulations and their expression of various surface antigens in sheep. ANIMALS: 12 healthy multiparous, nonpregnant, nonlactating fine-wool Merino ewes. PROCEDURE: Beta-1,3-glucan in pyrogen-free saline solution (PFSS; n = 6), rOvIL-2 in PFSS (3), or PFSS (3) was infused on days 0 and 7 in 1 udder half of each ewe. Jugular vein blood and mammary secretion samples were taken before infusion and on days 2, 7, and 21 after infusion. Total and differential leukocyte counts were obtained, and blood and mammary cells were labeled for flow cytometry. RESULTS: Slight swelling of the mammary glands was observed on day 2 after rOvIL-2 but not after beta-1,3-glucan infusion. Both substances induced significant increase in mammary secretion leukocyte numbers, compared with controls. Beta-1,3-Glucan induced an influx of monocyte/macrophages, whereas neutrophils were the predominating cell population after rOvIL-2 infusion. Beta-1,3-glucan induced selection for CD4+, B-cell+, WC1+, and L-selectin+ lymphocytes on day 14 after infusion. By comparison, rOvIL-2 induced selection for B-cell+ and L-selectin+ lymphocytes on days 14 and 21 and depletion of CD8 and, to some degree, of IL-2R+ lymphocytes. Beta-1,3-Glucan induced an increase in the proportion of CD14+ leukocytes, indicating selective migration of monocyte/ macrophages to the nonlactating udder. CONCLUSION: Beta-1,3-Glucan and rOvIL-2 can modulate nonspecific immunity in the udder of sheep but may exert their effects by differing mechanisms. Clinical Relevance-Stimulation of the nonspecific defense against udder infections may improve control of mastitis.     

Effect of timing and size of photoperiod change on plasma FSH concentration and the correlation between FSH and age at first egg in pullets.

1. ISA Brown pullets were transferred at 6, 9, 12, 15, 18 or 20.3 weeks of age from an 8 h photoperiod to an 8, 10, 13 or 16 h photoperiod. Plasma follicle stimulating hormone (FSH) concentration was measured at transfer at 7 and 14 d afterwards, and age at first egg (AFE) was recorded. 2. Plasma FSH concentration in pullets reared on constant 8 h photoperiods generally increased with age but with a trough at 12 weeks. Plasma FSH increased during the first 14 d of photostimulation to a significantly higher concentration, compared with constant 8 h controls, when the photoperiod was increased to 13 or 16 h at 9, 12 or 15 weeks; but for the increase from 8 h to 10 h photoperiods FSH was only significantly higher than controls when the change was made at 12 weeks. 3. The change in plasma FSH concentration 14 d after photostimulation was significantly correlated with mean AFE (reported in Lewis et al., 1997) and appears to be a better predictor of gonadal development than concurrent changes in plasma LH concentration previously reported (Lewis et al., 1994).     

Ultrastructure of porcine circovirus in persistently infected PK-15 cells.

The ultrastructure of porcine circovirus was examined in persistently infected porcine kidney (PK)-15 cells. Virus-infected PK-15 cells had large numbers of intracytoplasmic inclusions, and a few cells had intranuclear inclusions. Intracytoplasmic inclusions were dispersed throughout the cytoplasm but were most numerous in the perinuclear cytoplasm. Inclusion were of various sizes, round to oval, and electron dense and were of two general types. Inclusions of the first type were small (0.1-0.5 microm diameter), not surrounded by trilaminar membranes, and granular with indistinct margins that blended with surrounding cytoplasm. Some contained 12+/-2-nm-diameter icosahedral virions in loose aggregates or rarely forming paracrystalline arrays. Small inclusions could be sites of viral assembly or maturation. Intracytoplasmic inclusions of the second type were larger (0.5-5.0 microm diameter) and more numerous and had abrupt margins surrounded by trilaminar membranes. They were more electron dense than small inclusions and were heterogeneous, containing various proportions of aggregated virions, electron-dense crystalline lamellae of 5 nm periodicity, and/or whorls of myelinoid membranes. Virions usually formed paracrystalline arrays and occasionally were loosely aggregated. Larger inclusions were typical of autophagolysosomes. Intranuclear inclusions were not membrane bound and were often associated with reticulated nucleoli or aggregates of heterochromatin. Some inclusions were irregularly shaped aggregates of indistinct, circular 10-12-nm-diameter viruslike particles. Others were 0.1-1.0 microm in diameter, round or ring shaped, dense, and finely granular, with sharply demarcated margins.     

Experimental infection of vaccinated slaughter ostriches in a natural, open-air feedlot facility with virulent Newcastle disease virus.

The presence of virulent Newcastle disease virus (NDV) since the 1993-94 epidemic in southern Africa holds major implications for the export of ostrich products from this region. A challenge experiment with this field strain was conducted in open-air feedlot facilities under strict biosecurity measures. The experiment was designed to follow vaccination and preslaughter quarantine regulations currently enforced in South African export ostrich facilities in order to determine the viremia period and immune response under these specific circumstances. One hundred forty-three slaughter ostriches were allocated into three test groups, according to the time period between pretrial vaccination and challenge (1-2 mo, 2-4 mo, 4-6 mo), and an unchallenged control group. All birds in the test groups were challenged by oral, tracheal, and ocular routes with a field isolate of NDV. They were slaughtered over the next 4 wk on nine separate occasions and bled on 12 occasions. Virus isolation was attempted from seven sets of pooled samples from each bird to determine the viremia period and the serum antibody concentrations were measured by hemagglutination inhibition (HI) and enzyme-linked immunosorbent assay (ELISA) methods to establish an immune response curve. NDV could be back-isolated only up to day 9 postinfection and from only six ostriches with poor immune response titers and corresponding to a rise in antibody levels above an indirect ELISA optical density reading of 0.33. Virus could be recovered only from brain and respiratory tract tissue. The HI test was less sensitive than the ELISA. Immune response curves did not differ significantly between the groups and peaked on day 14 post-infection. From these data, ELISA titers would appear to be a good indicator of the probability that an ostrich will be clinically infected after velogenic NDV challenge. These results also suggest that the current vaccination schedule enforced by the South African Veterinary Authorities results in protective immunity in up to 95% of slaughter ostriches from export approved facilities. The standard 30-day preslaughter quarantine period introduced as part of Crimean-Congo hemorrhagic fever virus control measures also appears sufficient to encompass the determined NDV viremia period of 9-11 days in slaughter ostriches.     

Effects of hemolysis on plasma electrolyte and chemistry values in the common green iguana (Iguana iguana).

Hemolysis of serum and plasma samples is a common problem in veterinary diagnostic laboratories. We measured the effects of hemolysis on nine plasma analytes in 10 clinically normal common green iguanas (Iguana iguana). Blood samples with moderate and marked hemolysis were produced from each iguana by freezing, centrifuging, and decanting plasma from a portion of each blood sample, and combining the nonhemolyzed plasma with different amounts of hemolyzed plasma from the same individual. Moderate hemolysis significantly increased plasma phosphorus levels. Marked hemolysis significantly increased plasma values of potassium, phosphorus, total protein, and aspartate aminotransferase. The severity of hemolysis must be considered when interpreting values for these analytes in iguana plasma.     

Retrospective study of cecocolic intussusception (cecal inversion) in nine horses (1982–1998)

We retrospectively evaluated the medical records and obtained follow-up information for nine horses which had been treated for cecocolic intussusception (CCI) between January 1982 and April 1998. During the 16-year study period, CCI was diagnosed in nine of 748 horses in which exploratory celiotomy was undertaken for abdominal pain, representing an incidence of 1.2%. Most affected horses (78%) were less than four years of age (median age was 12 months, age range was five months to 15 years). Cecocolic intussusception affected male horses (78%) more commonly than female horses. The most common clinical presentation was abdominal pain of a severe, acute nature or milder but recurrent signs of abdominal pain persisting in spite of conservative treatment for several days. Correction of CCI by either simple reduction or reduction followed by partial typhlectomy was successful if compromise of the intestine by devitalization and adhesion formation was not found at surgery. Definitive diagnosis of CCI necessitates exploratory celiotomy, although an ultrasonographic examination of the abdomen may confirm the diagnosis in some cases. When recognized early during the course of disease, surgical correction of CCI is associated with a favorable outcome; of the eight horses which underwent surgery in our series, five horses (63%) survived surgical correction of CCI. Handling of compromised gut during reduction of CCI necessitates extreme caution because the risk of intestinal tearing is quite high.