Alteration of immunological parameters in infectious bronchitis vaccinated-specific pathogen-free broilers after the use of different infectious bursal disease vaccines.

The vaccines currently available to control infectious bursal disease (IBD) include live-attenuated and inactivated vaccines, immune-complex vaccines, and vaccines consisting of viral constructs of herpesvirus of turkeys genetically engineered to express VP2 surface protein. To evaluate the impact of vaccines on the chicken immune system, 2 animal trials were performed in specific pathogen-free broiler chickens. In trial 1, birds were either vaccinated when they are one-day old with a dual recombinant herpes virus of turkey construct vaccine, expressing VP2 protein of (IBDV) and F protein of Newcastle disease virus, or an immune-complex IBDV vaccine or birds were not vaccinated. At 14, 28, and 35 D, the bursa of Fabricius was collected for bursa:body weight (B:BW) ratio calculation. In trial 2, birds were vaccinated when they were 1-day old according to the same protocol as trial 1, but at day 14, all groups also received a live infectious bronchitis (IB) vaccine. At 0, 7, 14, 21, and 28 days after IB vaccination, birds were tested by ELISA for IB serology and, soon after the last blood sampling, they were euthanized for collection of Harderian glands, trachea, and spleen and testing by flow cytometry for characterization of mononuclear cells. The immune-complex vaccine groups showed significantly lower B:BW ratio, lower IBV antibody titers, and higher mean percentage of CD8+ T cells in the spleen, trachea, and Harderian glands than those in the other experimental groups. The results of the in vivo trials coupled with a depth analysis of the repertoire of parameters involved in the immune response to IBD and IB vaccinations show one vaccine may influence the immune response of other vaccines included in the vaccination program.

Histomorphometric parameters and fractal complexity of the equine placenta from healthy and sick foals.

Computer-based digital image analysis of tissue samples shows promise both to reduce the subjectivity of traditional manual tissue assessments and potentially to shorten the time required to analyze each sample. The present study used digital image analysis to investigate the histomorphometric parameters and fractal complexity of the equine placenta from healthy and sick foals. We hypothesized that the placentas of sick foals could have a different growth pattern and complexity that could be objectively estimated by their fractal dimension (FD). Fourteen placentas from 30 mares were selected in the 2013 breeding season and divided into two groups: seven mares with normal pregnancy, eutocic delivery, and healthy foals (group 1) and seven mares with normal or high-risk pregnancy, eutocic delivery and sick foals (group 2). Four mares in group 2 were classified as having a high-risk pregnancy on the basis of anamnesis and/or ultrasound findings. Clinical diagnosis of group 2 foals included perinatal asphyxia syndrome (n = 4), prematurity/dysmaturity (n = 2), and both diagnoses (n = 1). Seven out of fourteen placentas showed diffuse gross abnormalities. Grossly abnormal placentas were observed in one out of seven (14.28%) animals in group 1 and in six out of seven (85.72%) animals in group 2. Digital image analysis proved to be reliable and efficient in segmentation, calculation, outline extraction of villi as also resulted in sampled test images. The placentas of group 1 foals displayed a uniform and homogeneous villi development, as revealed by geometric parameters and FD. These results can be interpreted as a harmonic growth pattern of microcotyledons throughout the placenta in healthy foals. By contrast, the placentas of group 2 foals showed a nonuniform growth pattern and complexity with more villi and more developed villi in pregnant horn (PH) and nonpregnant horn (NPH) compared with body (B) and higher FD in NPH than in the other areas. This finding can be interpreted as a compensatory growth with increased complexity. Our results show that morphometric analysis, particularly FD measurement, can be proposed as an ancillary histological tool for equine placenta evaluation. Chorionic villi tend to have greater branching and complexity in sick than in healthy foals, particularly in the NPH. This could represent an attempt to increase the exchange area between fetal and maternal compartments of the equine placenta, and merits further investigation.