Morbidity in California giant salamander (Dicamptodon ensatus Eschscholtz, 1833) caused by Euryhelmis sp. Poche, 1926 (Trematoda: Heterophyiidae).

In the fall of 2021, California Department of Fish and Wildlife reported larval and adult California giant salamanders (Dicamptodon ensatus Eschscholtz, 1833) with skin lesions at multiple creeks in Santa Clara and Santa Cruz Counties, California, USA. Field signs in both stages included rough, lumpy textured skin, and larvae with tails that were disproportionately long, flat, wavy, and flaccid. Presence of large-bodied larvae suggested delayed metamorphosis, with some larvae having cloudy eyes and suspected blindness. To determine the cause of the disease, three first-of-the-year salamanders from one location were collected, euthanized with 20% benzocaine, and submitted for necropsy to the U.S. Geological Survey, National Wildlife Health Center. Upon gross examination, all salamanders were emaciated with no internal fat stores, and had multiple pinpoint to 1.5-mm diameter raised nodules in the skin over the body, including the head, gills, dorsum, ventrum, all four limbs, and the tail; one also had nodules in the oral cavity and tongue. Histologically all salamanders had multiple encysted metacercariae in the dermis, subcutis, and skeletal muscles of the head, body, and tail that were often associated with granulomatous and granulocytic inflammation and edema. A small number of encysted metacercariae or empty cysts were present in the gills with minimal inflammation, and rarely in the kidney with no associated inflammation. Morphology of live metacercariae (Trematoda: Heterophyiidae), and sequencing of the 28S rRNA gene identified a species of Euryhelmis (Poche, 1926). Artificial digestion of a 1.65 g, decapitated, eviscerated carcass yielded 773 metacercariae, all of similar size and morphology as the live specimens. Based on these findings, the poor body condition of these salamanders was concluded to be due to heavy parasite burden. Environmental factors such as drought, increased temperature, and overcrowded conditions may be exacerbating parasite infections in these populations of salamander.

Bilateral Uveitis and Hyphema in a Catalina Macaw (Ara ararauna × Ara macao ) With Multicentric Lymphoma.

A 20-year-old, female Catalina macaw (Ara ararauna × Ara macao ) was presented with bilateral uveitis and hyphema. The hyphema initially improved with 0.12% prednisolone acetate ophthalmic drops (1 drop OU q4h for 7 days), but the hyphema recurred after the drops were tapered. The bird subsequently developed inappetance, weight loss, regurgitation, and lethargy and was euthanatized 24 days after initial presentation. Necropsy revealed marked splenomegaly and hepatomegaly, with significant mucosal ulcerations of the proventriculus and petechiation associated with both kidneys. Histopathologic examination revealed multicentric lymphoma, with neoplastic cells observed in ocular, splenic, hepatic, renal, proventricular, intestinal, pancreatic, and choanal tissue. Neoplastic lymphocytes effaced the iris, ciliary body, and the choroid of the eyes, and neoplastic lymphocytes were attached to the corneal endothelium and infiltrated the sclera, episclera, and conjunctivae. Immunohistochemical results indicated that the neoplastic lymphocytes were CD3(+) and CD79a(-), which is consistent with T-cell lymphoma.

Evaluation of the effect of formalin fixation on skin specimens in dogs and cats.

Skin and subcutaneous tissues are the origin of most common neoplasms affecting dogs, accounting for approximately one third of all tumors encountered in the species. Surgical excision is frequently the best chance for a cure; determining factors influencing the success of excision are vital for surgical management of cases. This work examined the shrinkage of skin of various lengths from three sites in formalin for both dogs and cats. Tissues were measured on the animal (initial measurement), at the time of excision (post-removal), and after formalin fixation (post-fixation). While shrinkage after tissue removal was found in samples from the thorax, abdomen, and rear leg in dogs and from the rear leg in cats, no significant shrinkage due to formalin fixation was detected in any sample except for the thoracic samples from the dog. Therefore, when determining where to make incisions to effect a surgical cure, initial measurements should take into account tissue shrinkage effects.

Degree of substitution of chlorin e6 on charged poly-L-lysine chains affects their cellular uptake, localization and phototoxicity towards macrophages and cancer cells.

Macromolecular photosensitizer conjugates are under investigation as improved delivery vehicles for dyes used in photodynamic therapy. We have previously described the use of conjugates between photosensitizers such as chlorine6 (ce6) and poly-L-lysine (pL) chains which are versatile molecular species because the size of the chain can be varied, and the overall charge can be altered from cationic through neutral to anionic. We now report on a series of pL-ce6 conjugates in their cationic (native), neutral (acetylated) and anionic (succinylated) forms, where the number of ce6 molecules attached to each chain was varied (pL: ce6 ratios, 1:4, 1:8, 1:12, and 1:16). The fluorescence emissions were measured in both saline and a disaggregating solvent. We studied two cell lines (an epithelial ovarian cancer, OVCAR-5 and a mouse macrophage, J774) and measured cellular uptake, subcellular localization (by confocal fluorescence microscopy) and phototoxicity. The cellular uptake of the conjugates with four substitution ratios all delivered at 2 µM ce6 equivalent concentration showed a maximum at 12 ce6 per chain for both cationic and anionic conjugates, but the uptake of the neutral conjugate was proportional to the substitution ratio. The macrophages took up several times more ce6 than the ovarian cancer cells. Confocal fluorescence micrographs showed more cellular fluorescence with the lower substitution ratios, and more lysosomal localization with the cationic conjugates. The phototoxicity was much higher for the neutral conjugates. For the cationic and neutral conjugates the 12 ce6 per chain was the most effective at killing cells, while for the anionic conjugate it was the 16 ce6 per chain. The anionic conjugate was better at killing OVCAR-5 cells, while the cationic was better for J774 cells, and the neutral was approximately the same. These data will help to optimize the parameters to be used in preparing polymeric-photosensitizer conjugates for photodynamic therapy.