Intranasal Exposure to Rift Valley Fever Virus Live-Attenuated Strains Leads to High Mortality Rate in Immunocompetent Mice.

Rift Valley fever virus (RVFV) is a pathogenic arthropod-borne virus that can cause serious illness in both ruminants and humans. The virus can be transmitted by an arthropod bite or contact with contaminated fluids or tissues. Two live-attenuated veterinary vaccines-the Smithburn (SB) and Clone 13 (Cl.

Copper Poisoning, a Deadly Hazard for Sheep.

Copper (Cu) is an essential microelement for animals. However, sheep are particularly susceptible to Cu intoxication, a deadly disease reported worldwide. The risk of developing this poisoning is higher in vulnerable breeds and in intensively managed lambs or milk sheep.

Chronic pithomycotoxicosis associated with obstructive rhinopathy in sheep.

Pithomycotoxicosis (facial eczema) is a seasonal hepatogenous photosensitization of sheep caused by the ingestion of sporidesmin contained in the spores of the fungus . We describe 4 cases of obstructive rhinopathy associated with chronic pithomycotoxicosis naturally occurring in the north of Spain. Sheep were 5 to 7 years old and Latxa breed.

Jaagsiekte sheep retrovirus found in milk macrophages but not in milk lymphocytes or mammary gland epithelia of naturally infected sheep.

Jaagsiekte sheep retrovirus (JSRV) causes ovine pulmonary adenocarcinoma. JSRV can be transmitted via infected colostrum or milk, which contain somatic cells (SCs) harboring JSRV provirus. Nevertheless, the cell types involved in this form of transmission and the involvement of the mammary gland remain unknown.

Neoplasia-Associated Wasting Diseases with Economic Relevance in the Sheep Industry.

We review three neoplastic wasting diseases affecting sheep generally recorded under common production cycles and with epidemiological and economic relevance in sheep-rearing countries: small intestinal adenocarcinoma (SIA), ovine pulmonary adenocarcinoma (OPA) and enzootic nasal adenocarcinoma (ENA). SIA is prevalent in Australia and New Zealand but present elsewhere in the world. This neoplasia is a tubular or signet-ring adenocarcinoma mainly located in the middle or distal term of the small intestine.

Evolution of the Seroprevalence of Pestivirus and Respiratory Viral Infections in Spanish Feedlot Lambs.

The presence of respiratory viruses and pestiviruses in sheep has been widely demonstrated, and their ability to cause injury and predispose to respiratory processes have been proven experimentally. A longitudinal observational study was performed to determine the seroprevalence of bovine parainfluenza virus type 3 (BPIV-3), bovine respiratory syncytial virus (BRSV), bovine herpesvirus type 1 (BHV-1) and pestiviruses in 120 lambs at the beginning and the end of the fattening period. During this time, the animals were clinically monitored, their growth was recorded, and post-mortem examinations were performed in order to identify the presence of pneumonic lesions in the animals.

Exogenous Small Ruminant Betaretrovirus Envelope Protein Is Detected in Draining Lymph Nodes in Contagious Respiratory Tumors of Sheep and Goats.

Contagious respiratory tumors of sheep and goats are epithelial neoplasms of the lung and nasal cavities. They are associated with oncogenic betaretroviruses known as jaagsiekte sheep retrovirus and enzootic nasal tumor retrovirus of sheep and goats. We investigated the presence of the envelope protein (ENV) of these retroviruses in retropharyngeal and mediastinal lymph nodes using a specific monoclonal antibody by immunohistochemistry methods, single-labeled or combined with ovine B or T lymphocytes or macrophage cell markers.

Enzootic nasal tumor virus type 2 envelope of goats acts as a retroviral oncogene in cell transformation.

Enzootic nasal tumor virus type 1 (ENTV-1) (ovine nasal tumor virus) and ENTV-2 (caprine nasal tumor virus) are known to be causative agents of enzootic nasal adenocarcinoma (ENA) in sheep and goats, respectively. Although the nucleotide and amino acid sequences of ENTV-1 and ENTV-2 are quite similar, they are recognized as phylogenetically distinct viruses. The envelope protein of ENTV-1 functions as an oncoprotein in the in vitro transformation of epithelial cells and fibroblasts.

Evidence of jaagsiekte sheep retrovirus-induced pulmonary adenocarcinoma in Ouled Djellal breed sheep in Algeria.

We report the occurrence of lung cancer in a six months old lamb of Ouled Djellal breed from Algeria. The main clinical sign was a considerable amount of whitish foamy fluid discharge from the nostrils when the animal head was lowered and the rear end was lifted. The post-mortem examination revealed the presence of enlarged, heavy and edematous lungs with diffuse or foci areas, reddish or white-gray in color.

Effect of Surface Chemistry and Associated Protein Corona on the Long-Term Biodegradation of Iron Oxide Nanoparticles In Vivo.

The protein corona formed on the surface of a nanoparticle in a biological medium determines its behavior in vivo. Herein, iron oxide nanoparticles containing the same core and shell, but bearing two different surface coatings, either glucose or poly(ethylene glycol), were evaluated. The nanoparticles' protein adsorption, in vitro degradation, and in vivo biodistribution and biotransformation over four months were investigated.

Multiparametric analysis of anti-proliferative and apoptotic effects of gold nanoprisms on mouse and human primary and transformed cells, biodistribution and toxicity in vivo.

Background: The special physicochemical properties of gold nanoprisms make them very useful for biomedical applications including biosensing and cancer therapy. However, it is not clear how gold nanoprisms may affect cellular physiology including viability and other critical functions. We report a multiparametric investigation on the impact of gold-nanoprisms on mice and human, transformed and primary cells as well as tissue distribution and toxicity in vivo after parental injection.

Evidence against a role for jaagsiekte sheep retrovirus in human lung cancer.

Background: Jaagsiekte sheep retrovirus (JSRV) causes a contagious lung cancer in sheep and goats that can be transmitted by aerosols produced by infected animals. Virus entry into cells is initiated by binding of the viral envelope (Env) protein to a specific cell-surface receptor, Hyal2. Unlike almost all other retroviruses, the JSRV Env protein is also a potent oncoprotein and is responsible for lung cancer in animals.

Cells infected with Jaagsiekte sheep retrovirus are detected in the bone marrow of asymptomatic sheep.

Ovine pulmonary adenocarcinoma (OPA) is a transmissible lung cancer caused by Jaggsiekte sheep retrovirus (JSRV). It is difficult to identify animals infected with JSRV but are clinically healthy. The virus does not induce a specific antibody response and, although proviral DNA sequences of JSRV can be found in mononuclear blood cells, the detection is inconsistent.

Genetic variability and in vitro transcriptional permissibility of primary ovine beta-retrovirus promoter isolates.

Objective: To assess genomic sequence conservation and variation in the proviral promoter of enzootic nasal tumor virus (ENTV) and Jaagsiekte sheep retrovirus (JSRV) in tissue samples from 3 sheep with nasal adenocarcinoma associated with ENTV and 3 sheep with pulmonary adenocarcinoma associated with JSRV and to identify a cell culture system that supports transcriptional activity of the ENTV and JSRV viral promoters.

Animals: 6 adult sheep.

Procedures: Standard PCR procedures for detection of the ENTV and JSRV long terminal repeat (LTR) promoter region were performed on samples from the 3 nasal adenocarcinomas and 3 pulmonary adenocarcinomas, respectively.

Host species barriers to Jaagsiekte sheep retrovirus replication and carcinogenesis.

Understanding the factors governing host species barriers to virus transmission has added significantly to our appreciation of virus pathogenesis. Jaagsiekte sheep retrovirus (JSRV) is the causative agent of ovine pulmonary adenocarcinoma (OPA), a transmissible lung cancer of sheep that has rarely been found in goats. In this study, in order to further clarify the pathogenesis of OPA, we investigated whether goats are resistant to JSRV replication and carcinogenesis.

Lung adenocarcinoma originates from retrovirus infection of proliferating type 2 pneumocytes during pulmonary post-natal development or tissue repair.

Jaagsiekte sheep retrovirus (JSRV) is a unique oncogenic virus with distinctive biological properties. JSRV is the only virus causing a naturally occurring lung cancer (ovine pulmonary adenocarcinoma, OPA) and possessing a major structural protein that functions as a dominant oncoprotein. Lung cancer is the major cause of death among cancer patients.

Enhanced replication and pathogenesis of Moloney murine leukemia virus in mice defective in the murine APOBEC3 gene.

Human APOBEC3G (hA3G), a member of the AID/APOBEC family of deaminases, is a restriction factor for human immunodeficiency virus (HIV). In the absence of the viral Vif protein hA3G is packaged into virions and during reverse transcription in a recipient cell it deaminates cytosines, leading to G-->A hypermutation and inactivation of the viral DNA. Unlike humans, who carry seven APOBEC3 genes, mice only carry one, mA3.

Colostrum and milk can transmit jaagsiekte retrovirus to lambs.

Ovine pulmonary adenocarcinoma (OPA) is a contagious disease caused by jaagsiekte sheep retrovirus (JSRV). In the three studies performed, we have obtained data of the importance of colostrum/milk (C/M) in the transmission of JSRV. In the first study, a group of sheep from a flock with a long history of OPA, samples from colostrum and peripheral blood leucocytes (PBLs) were collected.

A large animal model to evaluate the effects of Hsp90 inhibitors for the treatment of lung adenocarcinoma.

Ovine pulmonary adenocarcinoma (OPA) is a naturally occurring lung cancer of sheep caused by Jaagsiekte sheep retrovirus (JSRV). The JSRV envelope glycoprotein (Env) functions as a dominant oncoprotein in vitro and in vivo. In order to develop the basis for the use of OPA as a lung cancer model, we screened a variety of signal transduction inhibitors for their ability to block transformation by the JSRV Env.

Jaagsiekte sheep retrovirus is not detected in human lung adenocarcinomas expressing antigens related to the Gag polyprotein of betaretroviruses.

A proportion of human lung adenocarcinomas (hLACs) express an antigen related to the major capsid protein (CA) of Jaagsiekte sheep retrovirus (JSRV), a Betaretrovirus that causes a transmissible lung cancer in sheep. In this study, we have investigated whether JSRV or related betaretroviruses are expressed in hLACs. Results obtained indicate that JSRV is not associated with human lung adenocarcinomas.

Folic acid supplementation delays atherosclerotic lesion development in apoE-deficient mice.

Folic acid is a vitamin that when used as a dietary supplementation can improve endothelial function. To assess the effect of folic acid on the development of atherosclerosis, male apolipoprotein E-deficient mice fed a standard chow diet received either water (control group) or an aqueous solution of folic acid that provided a dose of 75 microg/kg/day, for ten weeks. At the time of sacrifice, blood was drawn and the heart removed.

Expression of the jaagsiekte sheep retrovirus envelope glycoprotein is sufficient to induce lung tumors in sheep.

Jaagsiekte sheep retrovirus (JSRV) is the causative agent of ovine pulmonary adenocarcinoma (OPA). The expression of the JSRV envelope (Env) alone is sufficient to transform a variety of cell lines in vitro and induce lung cancer in immunodeficient mice. In order to determine the role of the JSRV Env in OPA tumorigenesis in sheep, we derived a JSRV replication-defective virus (JS-RD) which expresses env under the control of its own long terminal repeat (LTR).

A PCR technique for the detection of Jaagsiekte sheep retrovirus in the blood suitable for the screening of ovine pulmonary adenocarcinoma in field conditions.

Ovine pulmonary adenocarcinoma (OPA) is a naturally occurring contagious lung neoplasia caused by jaagsiekte sheep retrovirus (JSRV). Although no specific circulating antibodies against the virus can be detected in infected sheep, JSRV proviral DNA sequences can be found in peripheral blood leukocytes (PBLs) in clinically affected and in a proportion of in contact animals. In this study, existing hemi-nested PCR procedure is compared with a new one-step PCR technique that was developed to minimise potential DNA contamination and reduce sample and reagent handling.

Infection of lung epithelial cells and induction of pulmonary adenocarcinoma is not the most common outcome of naturally occurring JSRV infection during the commercial lifespan of sheep.

Jaagsiekte sheep retrovirus (JSRV) is the causative agent of ovine pulmonary adenocarcinoma (OPA). In this study, we followed over a 31-month period the natural transmission of JSRV in adult sheep and in their offspring. We established groups derived from flocks with either a high or low incidence of OPA and monitored virus transmission, clinical disease and macroscopic/microscopic lung lesions at necropsy.