Results of the European Society of Toxicologic Pathology Survey on the Use of Artificial Intelligence in Toxicologic Pathology.

The European Society of Toxicologic Pathology (ESTP) initiated a survey through its Pathology 2.0 workstream in partnership with sister professional societies in Europe and North America to generate a snapshot of artificial intelligence (AI) usage in the field of toxicologic pathology. In addition to demographic information, some general questions explored AI relative to (1) the current status of adoption across organizations; (2) technical and methodological aspects; (3) perceived business value and finally; and (4) roadblocks and perspectives. AI has become increasingly established in toxicologic pathology with most pathologists being supportive of its development despite some areas of uncertainty. A salient feature consisted of the variability of AI awareness and adoption among the responders, as the spectrum extended from pathologists having developed familiarity and technical skills in AI, to colleagues who had no interest in AI as a tool in toxicologic pathology. Despite a general enthusiasm for these techniques, the overall understanding and trust in AI algorithms as well as their added value in toxicologic pathology were generally low, suggesting room for the need for increased awareness and education. This survey will serve as a basis to evaluate the evolution of AI penetration and acceptance in this domain.

The Application, Challenges, and Advancement Toward Regulatory Acceptance of Digital Toxicologic Pathology: Results of the 7th ESTP International Expert Workshop (September 20-21, 2019).

With advancements in whole slide imaging technology and improved understanding of the features of pathologist workstations required for digital slide evaluation, many institutions are investigating broad digital pathology adoption. The benefits of digital pathology evaluation include remote access to study or diagnostic case materials and integration of analysis and reporting tools. Diagnosis based on whole slide images is established in human medical pathology, and the use of digital pathology in toxicologic pathology is increasing. However, there has not been broad adoption in toxicologic pathology, particularly in the context of regulatory studies, due to lack of precedence. To address this topic, as well as practical aspects, the European Society of Toxicologic Pathology coordinated an expert international workshop to assess current applications and challenges and outline a set of minimal requirements needed to gain future regulatory acceptance for the use of digital toxicologic pathology workflows in research and development, so that toxicologic pathologists can benefit from digital slide technology.

Toxicologic Pathology Forum*: Opinion on Integrating Innovative Digital Pathology Tools in the Regulatory Framework.

Digital pathology is defined as the ability to examine digitized microscopic slides and to generate qualitative and quantitative data. The field of digital pathology is rapidly evolving and has the potential to revolutionize toxicologic pathology. Techniques such as automated 2-D image analysis, whole slide imaging, and telepathology are already considered "mature" technologies and have been used for decades in exploratory studies; however, many organizations are reluctant to use digital pathology in regulatory toxicology studies. Innovative technologies using digitized slides including high-content imaging modalities and artificial intelligence are still under development but are increasingly used in toxicologic pathology. While software validation requirements are already described, clear guidance for application of these rules to the digital pathology field are few and the acceptance of these technologies by regulatory authorities remains necessary for successful adoption of digital pathology into the mainstream of toxicologic pathology. This topic was discussed during a roundtable at the 2018 Annual Congress of the French Society of Toxicologic Pathology. This opinion article summarizes the discussion regarding the current questions and challenges on the integration of innovative digital pathology tools within a good laboratory practice framework and is meant to stimulate further discussion among the toxicologic pathology community. *This is an opinion article submitted to the Toxicologic Pathology Forum and does not constitute an official position of the Society of Toxicologic Pathology or the journal Toxicologic Pathology. The views expressed in this article are those of the authors and do not necessarily represent the policies, positions, or opinions of their respective agencies and organizations. The Toxicologic Forum is designed to stimulate broad discussion of topics relevant to regulatory issues in Toxicologic pathology. Readers of Toxicologic Pathology are encouraged to send their thoughts on these articles or ideas for new topics to toxicologicpathologyforum@toxpath.org .

Development and characterization of a largemouth bass cell line.

Abstract The development and characterization of a new cell line, derived from the ovary of Largemouth Bass Micropterus salmoides, is described. Gonad tissue was collected from Largemouth Bass that were electrofished from Oneida Lake, New York. The tissue was processed and grown in culture flasks at approximately 22°C for more than 118 passages during an 8-year period from 2004 to 2011. The identity of these cells as Largemouth Bass origin was confirmed by sequencing a portion of the cytochrome b gene. Growth rate at three different temperatures was documented. The cell line was susceptible to Largemouth Bass virus (LMBV) and its replication was compared with that of Bluegill Lepomis macrochirus fry (BF-2), one of the cell lines recommended for LMBV isolation by the American Fisheries Society Fish Health Section Blue Book. Quantitative PCR results from the replication trial showed the BF-2 cell line produced approximately 10-fold more LMBV copies per cell than the new Largemouth Bass cell line after 6 d, while the titration assay showed similar quantities in each cell line after 1 week. Received February 18, 2014; accepted April 16, 2014.

Bilateral ovarian cystadenoma in a geriatric African elephant (Loxodonta africana).

A 59-yr-old, captive female African elephant (Loxodonta africana) died of a cardiovascular collapse. Necropsy revealed bilateral replacement of the ovarian tissue by multiple cystic formations of up to 10 cm in diameter. The cysts were thin walled and filled with clear watery fluid. Smaller solid masses with an irregular surface projected from the wall of a few of the cysts. Histologically, the cystic structures were characterized by a single layer of well-differentiated cuboidal epithelial cells resting on a basement membrane. Occasionally the cysts contained nodular proliferations of single-layered, well-differentiated cuboidal epithelial cells forming anastomosing tubules and occasional papillary projections. The ovarian neoplasia was diagnosed as a bilateral multilocular serous ovarian cystadenoma. The nulliparous status and the advanced age may have contributed to the ovarian pathology.

Sulawesi tortoise adenovirus-1 in two impressed tortoises (Manouria impressa) and a Burmese star tortoise (Geochelone platynota).

Sulawesi tortoise adenovirus-1 (STAdV-1) is a newly discovered virus infecting endangered and threatened tortoises. It was initially described from a confiscated group of 105 Sulawesi tortoises (Indotestudo forsteni) obtained by the Turtle Survival Alliance and distributed to five sites with available veterinary care across the United States. In a 3-yr period from the initial outbreak, one multi-species collection that rehabilitated and housed adenovirus-infected Sulawesi tortoises experienced deaths in impressed tortoises (Manouria impressa) and a Burmese star tortoise (Geochelone platynota). Impressed tortoises that died had evidence of systemic viral infection with histopathologic features of adenovirus. Adenovirus was identified by consensus nested polymerase chain reaction (PCR) testing and subsequent sequencing of PCR products. Sequencing indicated that the adenovirus infecting these impressed tortoises and Burmese star tortoise was STAdV-1. In one impressed tortoise, viral infection was confirmed using transmission electron microscopy. In situ hybridization using a semiautomated protocol and fluorescein-labeled riboprobe identified STAdV-1 inclusions in spleen, liver, kidney, and testis of one impressed tortoise. The impact of this virus on captive and wild populations of tortoises is unknown; however, these findings indicate that STAdV-1 can be transmitted to and can infect other tortoise species, the impressed tortoise and Burmese star tortoise, when cohabitated with infected Sulawesi tortoises.

Meningitis caused by Mycoplasma mycoides subspecies capri in a goat.

A 2-year-old, female goat from Connecticut was submitted for necropsy with a 5-day history of pyrexia and intermittent neurologic signs, including nystagmus, seizures, and circling. Postmortem examination revealed suppurative meningitis. Histologic examination of the brain revealed that the meninges were diffusely infiltrated by moderate numbers of lymphocytes, macrophages, and fibrin, with scattered foci of dense neutrophilic infiltrate. Culture of pus and brainstem yielded typical mycoplasma colonies. DNA sequencing of the 16S ribosomal RNA gene revealed 99% sequence homology with Mycoplasma mycoides subspecies capri and Mycoplasma mycoides subspecies mycoides Large Colony biotype, which are genetically indistinguishable and likely to be combined as a single subspecies labeled M. mycoides subsp. capri. The present case is unusual in that not only are mycoplasma an uncommon cause of meningitis in animals, but additionally, in that all other reported cases of mycoplasma meningitis in goats, systemic lesions were also present. In the present case, meningitis was the only lesion, thus illustrating the need to consider mycoplasma as a differential diagnosis for meningitis in goats.

Actinomyces hyovaginalis-associated lymphadenitis in a Nubian goat.

A 6-year-old Nubian goat with a history of progressive weight loss and cough was presented for necropsy. The goat tested negative for antibodies to caseous lymphadenitis and caprine arthritis and encephalitis by hemagglutination inhibition assay and enzyme-linked immunosorbent assay, respectively. Postmortem examination revealed marked enlargement and, with histopathology, a fibrinopurulent necrotizing lymphadenitis of a tracheobronchial lymph node, with an appearance similar to that reported in cases of caseous lymphadenitis. An organism characterized by molecular methods as Actinomyces hyovaginalis was isolated together with Staphylococcus spp. and Streptococcus spp. from the lesion. No Corynebacterium pseudotuberculosis was recovered. To the authors' knowledge, this is the first isolation of A. hyovaginalis from a goat. Although the exact contribution of A. hyovaginalis to the lesion remains to be established, this case demonstrates that A. hyovaginalis should be considered in cases of caseous lymphadenitis-type lesions, especially when C. pseudotuberculosis has been excluded.