Equine sarcoid of the glans penis with bovine papillomavirus type 1 in a miniature horse (Falabella)

A 23-year-old Falabella gelding kept in Tochigi, Japan, for more than 20 years presented with a recurrent mass of the glans penis that was first noticed about a year earlier. Partial phallectomy was performed with no adjunctive therapy for local regrowth of the mass. The horse was euthanized 3 months after surgery for urinary retention due to suspected regrowth. The resected mass affected the genital and urethral mucosa of the glans penis, and was diagnosed as equine sarcoid by histopathology and identification of bovine papillomavirus (BPV) DNA. Phylogenetic analysis of the BPV genome of the sarcoid showed high sequence homology to BPV type 1 (BPV-1) from Hokkaido, Japan, suggesting a geographical relationship for BPV-1 in Japan.     

Differential expression of myostatin and its receptor in the porcine anterior pituitary gland

Myostatin (MSTN), known as growth and differentiation factor 8 (GDF-8), is a member of the transforming growth factor β (TGF-β) superfamily that negatively regulates skeletal muscle mass. Myostatin binds with high affinity to the receptor serine threonine kinase activin receptor type IIB (ActRIIB). Activins that also belong to the TGF-β superfamily, stimulate follicle-stimulating hormone production in gonadotrophs and suppress growth hormone and adrenocorticotropic hormone production in somatotrophs and corticotrophs, respectively. The aim of the present paper was therefore to clarify the endocrine action of MSTN in adenohypophysis. The present study details the expression and cellular localization of MSTN and ActRIIB in porcine anterior pituitary gland. The mRNA of MSTN and ActRIIB was consistently expressed in RT-PCR. Immunohistochemistry of MSTN and specific hormones showed that MSTN localized in thyrotrophs and gonadotrophs, in which most of the MSTN immunoreactive cells were identified as thyrotrophs. The immunostaining of ActRIIB was restricted to corticotrophs. These results indicate that MSTN was mainly produced in thyrotrophs and its receptor, ActRIIB, was restrictively contained in corticotrophs. Interestingly, thyrotrophs immunoreactive for MSTN were frequently close to corticotrophs immunoreactive for ActRIIB. The present study suggests that MSTN from thyrotrophs may regulate corticotroph function as a paracrine mediator among the porcine anterior pituitary cells.     

Genetic and antigenic characterization of bovine viral diarrhea viruses isolated from cattle in Hokkaido,Japan

In our previous study, we genetically analyzed bovine viral diarrhea viruses (BVDVs) isolated from 2000 to 2006 in Japan and reported that subgenotype 1b viruses were predominant. In the present study, 766 BVDVs isolated from 2006 to 2014 in Hokkaido, Japan, were genetically analyzed to understand recent epidemics. Phylogenetic analysis based on nucleotide sequences of the 5′-untranslated region of viral genome revealed that 766 isolates were classified as genotype 1 (BVDV-1; 544 isolates) and genotype 2 (BVDV-2; 222). BVDV-1 isolates were further divided into BVDV-1a (93), 1b (371) and 1c (80) subgenotypes, and all BVDV-2 isolates were grouped into BVDV-2a subgenotype (222). Further comparative analysis was performed with BVDV-1a, 1b and 2a viruses isolated from 2001 to 2014. Phylogenetic analysis based on nucleotide sequences of the viral glycoprotein E2 gene, a major target of neutralizing antibodies, revealed that BVDV-1a, 1b and 2a isolates were further classified into several clusters. Cross-neutralization tests showed that BVDV-1b isolates were antigenically different from BVDV-1a isolates, and almost BVDV-1a, 1b and 2a isolates were antigenically similar among each subgenotype and each E2 cluster. Taken together, BVDV-1b viruses are still predominant, and BVDV-2a viruses have increased recently in Hokkaido, Japan. Field isolates of BVDV-1a, 1b and 2a show genetic diversity on the E2 gene with antigenic conservation among each subgenotype during the last 14 years.     

Progesterone Profiles in the Caudal Vena Cava and Jugular Vein in Response to Pulsatile Luteinizing Hormone Stimulation Induced by GnRH Treatment During the Mid-luteal Phase in Lactating Dairy Cows

The aim of this study was to examine whether increased frequency of luteinizing hormone (LH) pulses influences luteal progesterone (P₄) secretion by measuring progesterone concentrations at the secreted (caudal vena cava) and circulating levels (jugular vein) in lactating dairy cows. Cows received six intravenous administrations of 2.5 μg of GnRH (gonadorelin acetate, n=4) or 2 ml saline (n=3) at 1-h intervals on 12.4 ± 0.4 (mean ± SE) days after ovulation. Blood samples were collected from the caudal vena cava and jugular vein every 12 min for 12 h (6 h before and after treatment). During the 6 h after treatment, frequency of LH pulses (5.3 ± 0.3 and 3.0 ± 0.0 pulses/6 h) and mean LH concentration (0.50 ± 0.06 and 0.38 ± 0.05 ng/ml) were greater (P<0.05) in GnRH-treated cows than in saline-treated cows. Mean P₄ concentration and amplitude of P₄ pulses in the caudal vena cava during the 6 h after treatment were greater (P<0.05) in GnRH-treated cows than in saline-treated cows, but the frequency of P₄ pulses was not different between the groups. Mean P₄ concentration in the jugular vein during the 6 h after treatment was also higher (P<0.05) in GnRH-treated cows than in saline-treated cows (7.0 ± 1.3 and 5.4 ± 0.9 ng/ml). These results indicate that the increased frequency of LH pulses stimulates progesterone secretion from the functional corpus luteum and brings about higher P₄ concentrations in the circulating blood in lactating dairy cows.