Claudio Gustavo Barbeito

Genomic and phylogenetic analysis of Argentinian Equid Herpesvirus 1 strains

Equid Herpesvirus 1 (EHV-1) has long been causally implicated in the occurrence of abortion, neonatal death, respiratory disease, and neurological disorders in horses. This study analyzed for the first time the characteristics of the genomic section of Argentinian EHV-1 strains and reconstructed the phylogeny in order to establish their origin. The phylogenetic dataset included 22 Argentinian strains and four additional reference strains isolated in other countries. The intergenic region between ORF 62 and ORF 63 was amplified by PCR and sequenced. The phylogenetic analysis carried out by parsimony algorithms showed that six of the Argentinian strains had the same origin as British and Japanese strains. The mapping of symptoms caused by EHV-1 suggested that neonatal disease developed through convergent evolution, which would constitute an adaptation mechanism of the virus. This study constitutes the first analysis carried out in South-American strains that establishes the phylogenetic relationship between Argentinian strains and rebuilds the evolutionary history of symptoms. This study focuses on a very important aspect of evolution of Herpesviridae infecting perissodactyls and attempts to shed light on the evolution of symptoms, an issue of high clinical interest.

Functional and histopathological changes induced by intraparenchymal injection of kainic acid in the rat cervical spinal cord

Kainic acid (KA) is an analog of the neurotransmitter glutamate and is widely used as an excitotoxic agent to lesion spinal cord networks, thus, providing an interesting model to learn basic mechanisms of spinal cord injury. The present work was aimed to evaluate motor and sensory performance of rats and analyze morphometric parameters of spinal cord neurons after KA injection. Animals were injected either with 0.75, 1 or 1.25 mM of KA at the C5 segment of the cervical spinal cord. Motor and sensory performance of the rats were evaluate at day 0 (before injection) and at days 1, 2, 3 and 7 post-injection (pi) and compared with those of saline-treated and non-operated animals. Animals were sacrificed at each time point for morphometric and histopathological analysis and compared among groups. All KA-treated animals showed a significant impairment at the motor and sensory tests for the ipsilateral forelimb in a concentration-dependent manner in comparison to saline-treated and non-operated animals. Neuronal cell count showed a significant loss of neurons at C4, C5 and C6 cervical segments when compared with those of saline-treated and non-operated animals. The contralateral side of the cervical segments in KA-treated rats remained unchanged. Some improvement at the motor and sensory tests was observed in animals injected with 0.75 and 1mM KA. Moreover, a mild increase in the neuronal count of the damaged segments was also recorded. The improvement recorded in the motor and sensory tests by day 7 pi may be a consequence of a neuron repairing mechanism triggered soon after the KA excitotoxic effect.

Development and proliferation of feline endometrial glands from fetal life to ovarian cyclicity

In this study it was determined the progression of uterine gland development from late gestation to puberty in domestic felids. Cell proliferation patterns for luminal (LE), glandular epithelium (GE) as well as stroma (S) were also described. Twenty-four uteri from female kittens: 45 and 65 days of gestation and 1 to 5, 8, 12, 16, 20 and 24 weeks postnatally were obtained. Uterine cross-sections were submitted for routine histological and immunohistochemical quantification of proliferating cell nuclear antigen (PCNA) techniques. Although prenatal uteri presented no indication of adenogenesis, 1 week old uteri revealed an incipient budding of the LE. During the second week budding increased and a mild degree of tubulogenesis of the GE into the stroma was detected. From the third to fifth weeks coiling, branching and cross-sections of glands appeared. These latter findings were more evident in week 8 when GE began to penetrate through much of the S to week 24. PCNA immunostaining revealed that DNA synthesis decreased throughout the study in the 3xa0cell compartments; (Pxa0<xa00.01). Luminal proliferation began prenatally, it maintained up to postnatal week 8 to markedly decrease to puberty (Pxa0<xa00.01). From postnatal week 3 up to week 8, GE mitotic activity was elevated becoming low thereafter (Pxa0<xa00.01). Stroma actively proliferated prenatally (Pxa0<xa00.01), diminishing up to week 8 (Pxa0<xa00.01) and again during the last weeks (Pxa0<xa00.01) of the study. It was concluded that, in domestic felids, proliferation of LE begins prenatally, histological uterine adenogenesis commenced during the first postnatal week and both events concluded by postnatal weeks 5-8.

Association between Degree of Anaplasia and Degree of Inflammation with the Expression of COX-2 in Feline Injection Site Sarcomas

Feline injection site sarcomas (FISSs) are mesenchymal neoplasms that develop at the sites of delivery of vaccines or other injectable products. Vaccine adjuvants can trigger an intense and persistent inflammatory response that may lead to neoplastic transformation. The proinflammatory role of cyclo-oxygenase (COX)-2 is well known and its overexpression has prognostic value in multiple neoplastic processes. One hundred and seventeen FISSs were evaluated for the degree of inflammation and anaplasia. Immunohistochemistry was used to determine the expression of COX-2 in these sarcomas. There was a significant association between the degree of inflammation and the expression of COX-2 by neoplastic cells. COX-2 expression was lower in tumours with higher degrees of anaplasia. These findings may be useful in predicting the sensitivity of FISSs to treatment with COX-2 inhibitors. The potential therapeutic use of such agents could then be restricted to tumours with lower degrees of anaplasia.

Microvascular lesions and changes in cell proliferation and death, and cytokine expression in the placentas of mice experimentally infected with Equid Herpesvirus 1

This study describes the changes observed in the placentas of mice experimentally infected with an abortigenic strain of EHV-1 at mid-pregnancy and euthanized at days 3 and 4 post-infection. We analyzed microscopic vascular alterations, cell proliferation and death by immunohistochemistry, and the expression of IFN-γ, TNF-α and the IL-10 by qPCR and flow cytometry. Infected mice showed slight respiratory signs and ruffled fur during the first two days post-infection. Virus isolation and DNA detection were positive only in the lungs of the infected mice. Vascular congestion, increase in the labyrinth area, and a significant reduction in fetal capillary endothelium surface of infected placentas were found. Cell proliferation was significantly reduced in the infected placentas, whereas the apoptosis was significantly increased. IL10, TNF and IFN-γ showed different expression in the infected placentas and uteri. The effects of EHV-1 during pregnancy depend on different pathogenic mechanisms in which vascular alterations, and cell death and proliferation and local cytokine changes are compromised.

Systemic infection induced by intranasal inoculation of Bovine herpesvirus 1.1 in pregnant and non-pregnant rabbits

Bovine herpesvirus (BoHV) type 1.1 (BoHV-1.1) causes repeated outbreaks of upper respiratory disease and abortion in cattle. The systemic effects of BoHV-1.1 in rabbits, using intranasal inoculation are reported. Female rabbits were divided into four groups and inoculated with the virus 10 days before mating, and at 15 or 22 days of pregnancy. Studies of the clinical signs, antibody production, virus isolation, and DNA detection as well as histological and immunohistochemical studies were carried out on lungs, kidneys, spleen, placentas, uteri and foetal tissues. All virus-inoculated animals developed respiratory clinical signs and a humoral response. BoHV-1.1 was isolated from nasal swabs and plasma rich in leukocytes, and viral DNA was detected in blood, dead foetuses and placentas. Histopathological lesions were found in the respiratory tract and some placentas and foetuses were immunohistochemically positive. Intranasal inoculation might be useful to study the systemic effects of BoHV-1.1 infection in the rabbit model.