Preparation and Application of Decanoic Acid/Arginine Hydrogels to a Transdermal Formulation.

We prepared a supramolecular hydrogel composed of decanoic acid and arginine (C10/Arg gel) and evaluated its application to a transdermal formulation. C10/Arg gel adjusted to pH 7 with 1 M NaOH aq or 1 M HCl aq provided a translucent hydrogel with a lamellar liquid crystal structure in the concentration region of decanoic acid ≥12% and arginine ≤9%. Rheological measurements showed that C10/Arg gel is a viscoelastic material with both solid and liquid properties, with elasticity being dominant over viscosity in the low shear stress region. The skin permeability of hydrocortisone (HC) and indomethacin (IM) from C10/Arg gels was investigated in vitro using hairless mouse skin and compared to control formulation drug suspensions (IM or HC) in water. The cumulative permeation amount of HC and IM from the C10/Arg gel at 10 h after application was approximately 16 and 11 times higher than that of the control, respectively. On the other hand, the flux of IM decreased with increasing arginine concentration, likely due to the acid-base interaction between Arg and IM in C10/Arg gel. Adequate drug skin permeation enhancement by C10/Arg gel requires optimizing the gel composition for each specific drug.

Hamster polyomavirus-associated T-cell lymphomas in Syrian hamsters (Mesocricetus auratus).

Hamster polyomavirus (HaPyV) infection has been associated with lymphomas in Syrian hamsters. In the present study, 14 cases of lymphoma in pet Syrian hamsters were pathologically examined and the involvement of HaPyV was investigated. Among 14 cases, 11 were abdominal and 3 were cutaneous lymphomas. The average ages of hamsters with abdominal lymphoma and cutaneous lymphoma were 7 months (range: 4-12 months) and 14 months (range: 6-23 months), respectively. Histologically, abdominal lymphomas were characterized by the diffuse growth of tumor cells with intermediate or large nuclei, low mitotic rates, the presence of tingible body macrophages, and the T-cell immunophenotype. Furthermore, 4/11 abdominal lymphomas were immunopositive for T-cell intracellular antigen-1, suggesting cytotoxic T-cell lymphomas. Cutaneous lymphomas were diagnosed as nonepitheliotropic T-cell lymphoma. Polymerase chain reaction (PCR) detected HaPyV DNA in 12/14 samples, and a sequence analysis of PCR amplicons confirmed >99% nucleotide identity to the published HaPyV sequences. In situ hybridization (ISH) for HaPyV DNA resulted in diffuse nuclear signals within tumor cells in 10/14 cases. Consistent with previous findings, all HaPyV-associated lymphomas were observed in the abdominal cavity of young hamsters. Polymerase chain reaction and ISH were useful for identifying the involvement of HaPyV in lymphomas, and ISH results indicated the presence of episomal HaPyV in neoplastic lymphocytes. The present study suggests that HaPyV infection is highly involved in abdominal lymphomas in young pet Syrian hamsters in Japan and provides diagnostic information on HaPyV-associated lymphoma.

Cystic rete ovarii and uterine tube adenoma in a rabbit.

A 6-year-old female rabbit was presented to a veterinary clinic, and the result of ultrasound examination suggested a tumor in the uterine tube. Subsequently, both ovaries and uterus were surgically removed. In gross, a single large cyst in the right ovary and enlargement of the left uterine tube were observed. Histological examination revealed that the cyst had developed in the hilus of the ovary and was lined by single-layered cuboidal cells. In the left uterine tube, a tumor composed of epithelial cells arranged in tubular structures and pleomorphic cells between the tubular structures was observed. Immunohistochemically, the epithelial cells of the cyst were positive for pan-cytokeratin, cytokeratin 18, CD10, E-cadherin, calretinin and estrogen receptor; the tumor cells of the left uterine tube were positive for pan-cytokeratin, cytokeratin 18, E-cadherin, vimentin, calretinin and estrogen receptor. From these results, the cyst was diagnosed as cystic rete ovarii, and the tumor was diagnosed as adenoma of the uterine tube. This case is the first to demonstrate cystic rete ovarii and uterine tube adenoma in rabbits.

Cystic rete testis with testicular dysplasia in a rabbit.

An 8-year-old intact rabbit was presented to a veterinary hospital with a complaint of enlarged left scrotum. Histological examination revealed a single large cyst adjacent to an efferent ductule-like tissue. The cyst wall was composed of monolayer cuboidal cells surrounded by dysplastic testicular tissue, and the seminiferous tubules were not developed at all. The epithelial cells of the cyst possessed the same properties as the epithelial cells of the rete testis that were positive for CD 10 and cytokeratin 18, negative for p63 and lacked desmin-positive muscular layer. The dysplastic testicular tissue was composed of two types of cells: small pleomorphic cells with a condensed nucleus (sex cord-like cells) and large round cells with cytoplasmic lipid droplets (Leydig cells). Both of these cells were positive for vimentin and melan A that are consistent with the staining pattern of Sertoli cells and Leydig cells. This is the first report to demonstrate cystic rete testis with testicular dysplasia in animals.

Genetic analysis of beak and feather disease virus derived from a cockatiel (Nymphicus hollandicus) in Japan.

Psittacine beak and feather disease (PBFD), which is caused by beak and feather disease virus (BFDV), has been reported in a wide range of psittacine species, except the cockatiel (Nymphicus hollandicus), in which PBFD has rarely been reported. We detected BFDV from a case of PBFD in a cockatiel in the present study. The virus was designated CO-JA. The whole genome sequence of CO-JA had from 86 to 98% homology with BFDVs in psittacine species. CO-JA clustered with isolates derived from other cockatoos in phylogenetic analyses based on two major virus proteins. We concluded that genetic data cannot explain the reason why PBFD is rarely found in the cockatiel.