Identification of two homologs of the Kaposi's sarcoma-associated herpesvirus (human herpesvirus 8) in retroperitoneal fibromatosis of different macaque species

Simian retroperitoneal fibromatosis (RF) is a vascular fibroproliferative neoplasm which has many morphological and histological similarities to human Kaposi's sarcoma (KS). Like epidemic KS in AIDS patients, RF is highly associated with an immunodeficiency syndrome (simian acquired immunodeficiency syndrome [SAIDS]) caused by a retrovirus infection. Recently, a new gammaherpesvirus, called Kaposi's sarcoma-associated herpesvirus (KSHV) or human herpesvirus 8 (HHV8), has been identified in KS tumors, suggesting that KS has a viral etiology. Our previous experimental transmission studies and epidemiological data suggest that RF also has an infectious etiology. In order to determine whether a similar virus is also associated with RF, we have assayed for the presence of an unknown herpesvirus using degenerate PCR primers targeting the highly conserved DNA polymerase genes of the herpesvirus family. Here we provide DNA sequence evidence for two new herpesviruses closely related to KSHV from RF tissues of two macaque species, Macaca nemestrina and Macaca mulatta. Our data suggest that KSHV and the putative macaque herpesviruses define a new group within the subfamily Gammaherpesvirinae whose members are implicated in the pathogenesis of KS and KS-like neoplasms in different primate species.

A general survey of tumours in the horse

Published figures from veterinary schools indicate that tumours may account for about 1 to 3 per cent of surgical cases. In this paper an account is given of clinical and pathological aspects of the tumours that are most likely to be encountered in practice, either as visibly or palpably detectable masses of tissue, or as internal tumours responsible for clinical signs. Amongst the common and important tumours dealt with, the most prominent are "equine sarcoid", squamous-cell carcinoma (of eye region and of glans penis), granulosa-cell tumours and melanomas. Well over a hundred references provide entry to the relevant literature. The need for further pathological and clinical studies of equine tumours is stressed.

Histological survey of tumours of the horse, with particular reference to those ofthe skin

In a histological survey of 244 tumerous growths from 155 horses, the tumours commonly found were fibromas, squamous cell carcinomas, sarcoids and papillomas, most frequently affecting the skin, external genitalia, eye and orbit. The histological features that differentiate fibroblastic citaneous growths are detailed so that the clinical behaviour of these distinct neoplasms can be studied.

Characterization of exogenous type D retrovirus from a fibroma of a macaque with simian AIDS and fibromatosis

A novel type D retrovirus was isolated by cocultivation of explants of fibromatous tissue from a rhesus monkey (Macaca mulatta) with immunodeficiency and retroperitoneal fibromatosis. This type D virus, isolated from a macaque with simian acquired immunodeficiency syndrome (SAIDS-D/Washington), is exogenous and is partially related to the Mason-Pfizer and the langur monkey type D viruses. The SAiDS-D virus can be distinguished from all other primate retroviruses by antigenicity and molecular hybridization. Nucleic acid hybridization studies reveal that the origin of the SAIDS-D isolate may reside in Old World monkey (subfamily Colobinae) cellular DNA.

Fibropapillomatosis in stranded green turtles (Chelonia mydas) from the eastern United States (1980-98): trends and associations with environmental factors

We examined data collected by the US Sea Turtle Stranding and Salvage Network on 4,328 green turtles (Chelonia mydas) found dead or debilitated (i.e., stranded) in the eastern half of the USA from Massachusetts to Texas during the period extending from 1980 to 1998. Fibropapillomatosis (FP) was reported only on green turtles in the southern half of Florida (south of 29 degrees N latitude). Within this region, 22.6% (682/3,016) of the turtles had tumors. Fibropapillomatosis was more prevalent in turtles found along the western (Gulf) coast of Florida (51.9%) than in turtles found along the eastern (Atlantic) coast of Florida (11.9%) and was more prevalent in turtles found in inshore areas (38.9%) than in turtles found in offshore areas (14.6%). A high prevalence of FP corresponded to coastal waters characterized by habitat degradation and pollution, a large extent of shallow-water area, and low wave energy, supporting speculation that one or more of these factors could serve as an environmental cofactor in the expression of FP. A high prevalence of FP did not correspond to high-density green turtle assemblages. Turtles with tumors were found most commonly during the fall and winter months, and the occurrence of tumors was most common in turtles of intermediate size (40-70-cm curved carapace length). Stranded green turtles with tumors were more likely to be emaciated or entangled in fishing line and less likely to have propeller wounds than were stranded green turtles without tumors. Turtles with and without tumors were equally likely to show evidence of a shark attack. The percent occurrence of tumors in stranded green turtles increased from approximately 10% in the early 1980s to over 30% in the late 1990s. Fibropapillomatosis was first documented in southernmost Florida in the late 1930s and spread throughout the southern half of Florida and the Caribbean during the mid-1980s. Because green turtles living in south Florida are known to move throughout much of the Caribbean, but are not known to move to other parts of the USA or to Bermuda, the spread and current distribution of FP in the western Atlantic, Gulf of Mexico, and Caribbean can be explained by assuming FP is caused by an infectious agent that first appeared in southern Florida. Aberrant movements of captive-reared turtles or of turtles that are released into areas where they were not originally found could spread FP beyond its current distribution.

Association of herpesvirus with fibropapillomatosis of the green turtle Chelonia mydas and the loggerhead turtle Caretta caretta in Florida

Sea turtle fibropapillomatosis (FP) is a disease marked by proliferation of benign but debilitating cutaneous fibropapillomas and occasional visceral fibromas. Transmission experiments have implicated a chloroform-sensitive transforming agent present in filtered cell-free tumor homogenates in the etiology of FP. In this study, consensus primer PCR methodology was used to test the association of a chelonian herpesvirus with fibropapillomatosis. Fibropapilloma and skin samples were obtained from 17 green and 2 loggerhead turtles affected with FP stranded along the Florida coastline. Ninety-three cutaneous and visceral tumors from the 19 turtles, and 33 skin samples from 16 of the turtles, were tested. All turtles affected with FP had herpesvirus associated with their tumors as detected by PCR. Ninety-six percent (89/93) of the tumors, but only 9% (3/33) of the skin samples, from affected turtles contained detectable herpesvirus. The skin samples that contained herpesvirus were all within 2 cm of a fibropapilloma. Also, 1 of 11 scar tissue samples from sites where fibropapillomas had been removed 2 to 51 wk earlier from 5 green turtles contained detectable herpesvirus. None of 18 normal skin samples from 2 green and 2 loggerhead turtles stranded without FP contained herpesvirus. The data indicated that herpesvirus was detectable only within or close to tumors. To determine if the same virus infected both turtle species, partial nucleotide sequences of the herpesvirus DNA polymerase gene were determined from 6 loggerhead and 2 green turtle samples. The sequences predicted that herpesvirus of loggerhead turtles differed from those of green turtles by only 1 of 60 amino acids in the sequence examined, indicating that a chelonian herpesvirus exhibiting minor intratypic variation was the only herpesvirus present in tumors of both green and loggerhead turtles. The FP-associated herpesvirus resisted cultivation on chelonian cell lines which support the replication of other chelonian herpesviruses. These results lead to the conclusion that a chelonian herpesvirus is regularly associated with fibropapillomatosis and is not merely an incidental finding in affected turtles.

Distribution of chelonid fibropapillomatosis-associated herpesvirus variants in Florida: molecular genetic evidence for infection of turtles following recruitment to neritic developmental habitats

Marine turtle fibropapillomatosis is associated with chelonid fibropapilloma-associated herpesvirus (C-FP-HV) and commonly affects juvenile green turtles (Chelonia mydas) in neritic (nearshore) habitats. Green turtles have a complex life history, characterized by shifts in trophic level as well as habitat during ontogeny. Thus, several hypotheses can be proposed for when turtles become infected with C-FP-HV. They may acquire the virus at an early stage in the life cycle, including prenatal, hatchling, or the posthatchling pelagic stages. Alternatively, they may become infected later in life after they emigrate from the open ocean to neritic habitats. Each hypothesis generates predictions about the spatial distribution of genetic variants of C-FP-HV among nearshore sites within a region. Sequencing of polymerase chain reaction-amplified viral DNA from fibropapillomas of individual turtles was used to genotype the viral variants present in marine turtles from different coastal areas in Florida. We found four distinct virus variants (A, B, C, and D), two of which (A and C) were present in multiple turtle species. Green turtles in Florida were infected with variants A, B, and C. Variant A was found in green turtles from all three areas. Outside the Indian River Lagoon, variant A was most commonly detected and was found in >94% of diseased green turtles and 70% of loggerhead sea turtles (Caretta caretta) in the Florida Bay/Florida Keys. However, in the Indian River Lagoon, variant B was found in >94% of affected green turtles. Variant B was not detected outside of the Indian River system. Chi-square analysis strongly supported (P<0.001) an association between viral variant distribution in green turtles and location. On the basis of the assumption that juvenile green turtles found in Florida's west-central coast, Florida Keys, and Indian River Lagoon areas represented recruits from a mixed pelagic population, we expected that the distribution of viral variants in these turtles would be relatively homogeneous among locations; this would correspond to infection in the earlier phases of their life cycle. The heterogeneous distribution of viral variants in green turtle tumors from different Florida coastal locations strongly supports the hypothesis that, during epizootics, turtles are infected with specific C-FP-HV variants after they arrive as juveniles in neritic habitats. The conclusion that C-FP-HV is acquired after turtles recruit to nearshore habitats should help focus further research efforts on understanding the mechanisms of transmission and raises the possibility that the effect of fibropapillomatosis on turtle populations might be reduced by management strategies designed to break the cycle of transmission in these locations.

Diagnostic immunohistochemistry of canine round cell tumors

Sixty-five canine skin neoplasms studied using immunocytochemistry, included 22 histiocytomas, 18 amelanotic melanomas, 14 cutaneous lymphosarcomas, six mast cell tumors, and five transmissible venereal tumors. Formalin-fixed, paraffin-embedded sections were stained using the avidin-biotin-peroxidase complex (ABC) immunoperoxidase technique for reactivity with S-100 protein, kappa and lambda immunoglobulin light chains, alpha-1-antitrypsin, alpha-1-antichymotrypsin, leukocyte common antigen (LCA), neuron-specific enolase, keratin, cytokeratin, muramidase, and vimentin. Detection of S-100, kappa and lambda light chains, neuron-specific enolase, and vimentin were most useful for screening these neoplasms. None of the markers examined was consistent in staining histiocytomas. While reactivity of S-100 (ten cases) and neuron-specific enolase (ten cases) was detected in some amelanotic melanomas, lambda light chain immunoglobulin (eight cases) was relatively consistent in cutaneous lymphomas. Mast cell neoplasms reacted with avidin and, therefore, were positive, even on negative control sections. Vimentin reacted strongly on all amelanotic melanomas and transmissible venereal tumors examined. These antibodies are helpful adjuncts in the differential diagnosis of canine skin tumors.

Skin neoplasms of dogs in Sydney

In a survey of dogs in Sydney, mastocytomas (16.1%) and histiocytomas (14.0%) were the most common in a total of 1,000 skin neoplasms. The basal cell and appendage group provided 25.5% of the neoplasms. The prevalence of the various neoplasms, the age of affected dogs, the proportion in the sexes, the common sites of occurrence and prevalence in the different breeds were broadly similar to findings in surveys in other countries, except that in the Syndeny dogs there was a greater prevalence of histiocytomas and haemangiopericytomas, a more common occurrence of histiocytomas in mature dogs, an occurrence of histiocytomas in similar numbers on the head, trunk and limbs, and a remarkably common development of squamous cell carcinomas in Dalmatians.

Relationship between fibropapillomatosis and environmental quality: a case study with Chelonia mydas off Brazil

We documented the presence of fibropapillomatosis (FP), a debilitating tumor-forming disease, in marine turtles in Espirito Santo Bay (Brazil) from March 2007 to April 2008, and assessed the value of a specific environmental index for predicting the prevalence of FP. Turtles were captured monthly with entanglement nets and scored for presence and severity of FP. For the assessment of habitat quality, we used the ecological evaluation index (EEI) based on benthic macrophytes. The FP-free control area was classified as good quality (EEI = 8) and the study area, with high FP prevalence, was classified as bad quality (EEI= 2). Prevalence of FP in the study area was 58.3% with an average of 40 tumors per individual, and prevalence varied positively with curved carapace length (CCL). No FP was seen in the control area. The number of turtles heavily afflicted (tumor score category 3) was 10 times larger than those lightly affected (tumor score category 1). Most tumors were found on or near the front and rear flippers; no oral tumors or internal tumors were found. At recapture, 41% of formerly tumor-free turtles revealed FP, often increasing in severity with time, and very few turtles showed signs of disease regression. From the results of this study we concluded that FP is particularly severe in Espírito Santo Bay. Future studies should focus on evaluating how widespread FP is in Brazil, whether prevalence is increasing or decreasing, and elucidating the pathology and pathogenesis of FP in sea turtles in Brazil.

Equine juvenile mandibular ossifying fibroma

Benign proliferative fibro-osseous lesions of the rostral mandible in six young horses are classified as equine juvenile mandibular ossifying fibroma. Histologically there is a characteristic abrupt transition from subgingival fibroblastic stroma to a zone of proliferating osteoblasts that form irregular spicules of osteoid. The layer of proliferating osteoblasts blends with a deeper zone of bony trabeculae rimmed by osteoblasts and separated by intertrabecular spaces of moderate cellular density. Incomplete surgical excision resulted in local recurrence, while rostral mandibulectomies resulted in no recurrence. The predilection for the rostral mandible of young horses coupled with the similar clinical, radiographic, and histological characteristics supports the classification of this lesion as a distinct entity.

Treatment of periocular tumours of horses using radioactive gold198 grains

The literature is briefly reviewed concerning the clinical features of equine cutaneous tumours. The data from 19 horses with periocular skin tumours are reported together with the results of their treatment by implantation with radioactive gold198. The principles governing the implantation of radioactive sources are explained and a method for computing the initial activity of the sources is outlined. Five histologically different tumour types were treated in this series of 19 horses, 2 horses were bilaterally affected. The techniques of implantation using a simple needle/stillette combination and a purpose built gold grain implantation gun are described and the postoperative course of the animals is traced. The treatment was successful in ablating the tumour mass and preventing regrowth in 19 of 21 periocular tumour groups. The cosmetic effects of the treatment were found to be satisfactory. Emphasis is laid on the care needed in handling the radioactive material and on the need for a thorough understanding of the principles involved in radiotherapy. Doses received by the operator during an implantation procedure are quoted which show that the technique is safe as well as being effective.

Virus-induced papillomas of the alimentary tract of cattle

An abattoir survey was carried out to determine the incidence and aetiology of squamous papillomas of the alimentary tract of cattle in Scotland and North England as they were suspected of being involved in the genesis of alimentary carcinoma in certain localized geographical areas. A total of 7,746 cattle of a wide age range was examined. Various subsets of this number were subjected to analyses of certain specific factors. The calculated overall incidence was 19% and the detailed site incidence and tumour multiplicity are given. The sites at which papillomas were found were identical with those at which carcinoma had been noted in animals from a high-cancer area. The number of sites affected by papilloma and the tumour multiplicity were much lower in the general population than in the high-cancer area. Inclusion bodies, identified by electronmicroscopy as virus, were found in tumour cell nuclei and a typical papilloma virus was purified from the tumours. The structure of the tumours is described and the possible plurality of bovine papilloma-viruses is discussed in the light of recent findings in the human viruses. The general interest of a naturally occurring and geographically localized oncogenic system, in which an environmental carcinogen and a virus might be involved, is extended.

Detection of papillomavirus-DNA in mesenchymal tumour cells and not in the hyperplastic epithelium of feline sarcoids

We examined 12 formalin-fixed paraffin-embedded feline skin tumours which had the histopathological features of fibropapillomas for the presence of papillomavirus (PV) DNA using touchdown polymerase chain reaction (PCR), DNA sequencing and nonradioactive in situ hybridization. Nine of the tumours contained a 102-bp PCR product demonstrated using consensus PV primers that amplify a portion of the L1 gene. The nucleotide sequences are closely related, but not identical to that of ovine PV type 2, rabbit oral PV and reindeer PV. The deduced amino acid sequences had strong homologies with the major capsid protein L1 of deer PV, bovine papillomavirus (BPV) 1 and BPV 2, and European elk PV. Although PV antigens were not detected in any of the tumours by immunohistochemistry, PV DNA was demonstrated in individual mesenchymal cells or cell nests of 4/12 tumours by in situ hybridization. A nonproductive infection of mesenchymal fibroblast-like tumour cells with a papillomavirus would explain the lack of PV antigen expression and the absence of PV DNA in the hyperplastic epithelium. Because these tumours and their pathogenesis are similar to equine sarcoids, we suggest that they should be reclassified as 'feline sarcoids' instead of fibropapillomas.

Cutaneous fibropapillomas and renal myxofibroma in a green turtle, Chelonia mydas

A debilitated 7 kg juvenile green turtle (Chelonia mydas mydas) with multiple ulcerated and infected cutaneous fibropapillomas was clinically evaluated and found to have a nonregenerative anemia, hypoproteinemia, hypoalbuminemia and several electrolyte abnormalities. Surgery was performed to remove the larger tumors. The turtle did not eat postsurgically, and an attempt was made to place a pharyngostomy tube utilizing endoscopy. Edematous esophageal papillae, the angulation of the gastroesophageal junction, and a S-shaped configuration of the esophagous prevented successful placement of the tube. The animal was found dead the next day and necropsied. Multiple large white firm nodules were seen bulging from both kidneys. Microscopic examination of the nodules resulted in a diagnosis of renal myxofibroma.

Histopathologic features and post-surgical sequelae of 57 cutaneous neoplasms in ferrets (Mustela putorius furo L.)

The study of the signalment, histomorphologic features, and post-surgical clinical progress of 57 cutaneous neoplasms in 55 domestic ferrets (Mustela putorius furo L.) was based on diagnostic pathologic accessions (1987-1992) from 142 ferrets. Mean age of the group was 4.3 years; 31/54 (57%) were female and 23/54 (43%) were male. Thirty-three (58%) of the cutaneous neoplasms were basal cell tumors. The mean age of ferrets with basal cell tumor was 5.2 years, and 23/33 (70%) were female. Histologically, the basal cell tumors were composed of well-differentiated basaloid epithelial cells with various degrees of squamous and sebaceous differentiation, similar to those seen in basal cell neoplasms of dogs. Nine of the 57 (16%) cutaneous neoplasms were mastocytomas. The mean age of ferrets with mastocytoma was 4.1 years; four were male, four were female, and the sex of one was unrecorded. Histologically, the mastocytomas were composed of well-differentiated mast cells with few eosinophils, similar to cutaneous mastocytomas of domestic cats. The mast cells had a small number of metachromatic cytoplasmic granules, and in six of eight neoplasms the granules had an affinity for conjugated avidin-peroxidase. Six of the cutaneous neoplasms (11%) were fibromas. The mean age of ferrets with fibroma was 2.7 years; 5 (83%) were male. Two cutaneous hemangiomas (4%) were in females, which were 4 and 5 years of age. There was one each hemangiosarcoma, cutaneous polyp, anal gland adenocarcinoma, lymphosarcoma of the prepuce and inguinal lymph node, and adenocarcinoma of the prepuce.

Relationship of body-weight gain to longevity and to risk of development of nephropathy and neoplasia in Sprague-Dawley rats

The relationship of weight gain to survival, risk of development of chronic progressive nephropathy and risk of development of various neoplasms has been studied in the control groups from two routine chronic toxicity studies in Sprague-Dawley rats. The groups comprised 100 CFY strain rats of each sex observed up to the age of 109 wk and 120 CD strain rats of each sex observed up to 111 wk of age (females) or 121 wk (males). The eventual incidence of tumours was found to be related to body weight at several ages. There was also a statistically significant association between high body weight at various ages and increased mortality, particularly in the CD strain and particularly in females. The 'heavy' rats proved to have an increased risk of developing both progressive nephropathy and certain tumours. This relationship was particularly marked for pituitary tumours in both sexes and for benign and malignant mammary tumours in females, and was significant irrespective of whether tumours coexisting with marked or severe progressive nephropathy were classified as fatal or incidental. There was also some evidence that increased body weight was positively associated with risk of islet-cell tumours and lipomatous tumours in males and fibromatous tumours in females. The observations illustrate how non-specific factors, such as those that affect body weight, may profoundly influence mortality and tumour incidence in chronic toxicity studies. The findings also highlight the difficulty of classifying particular neoplasms as incidental or fatal where other potentially life-threatening pathology (e.g. progressive nephropathy) is present.

Differentiation-specific expression from the bovine papillomavirus type 1 P2443 and late promoters

The papillomavirus life cycle is tightly linked with keratinocyte differentiation in squamous epithelia. Vegetative viral DNA replication begins in the spinous layer, while synthesis of capsid proteins and virus maturation is restricted to the most differentiated or granular layer of the epithelium. In this study, in situ hybridization of bovine fibropapillomas was used to demonstrate that the activity of two promoters of bovine papillomavirus type 1 (BPV-1) is regulated in a differentiation-specific manner. In situ hybridization with a late promoter (PL)-specific oligonucleotide probe suggested that PL is dramatically upregulated in the granular layer of the fibropapilloma. Northern (RNA) blot analysis of RNA from BPV-1-infected fibropapillomas indicated that the three major BPV-1 late-region mRNAs were transcribed from PL. These RNAs include the previously described L1 (major capsid) mRNA as well as two larger mRNAs. The two larger mRNAs were characterized and shown to contain the L2 (minor capsid protein) open reading frame as well as the L1 open reading frame. In contrast to PL, the P2443 promoter was maximally active in basal keratinocytes and the fibroma. The major mRNA transcribed from P2443 is the putative E5 oncoprotein mRNA which is spliced between nucleotides 2505 and 3225. No signal was detected above the basal layer with use of a probe specific for this mRNA. The E5 oncoprotein has previously been localized by immunoperoxidase staining to the granular cell layer as well as the basal cell layer of the fibropapilloma (S. Burnett, N. Jareborg, and D. DiMaio, Proc. Natl. Acad. Sci. USA 89:5665-5669, 1992). These data suggest that E5 proteins in the basal cell and granular cell layers are not translated from the same mRNA.

Biochemical responses to fibropapilloma and captivity in the green turtle

Blood biochemical parameters were compared for green turtles (Chelonia mydas) with and without green turtle fibropapillomatosis (GTFP) from both captive and wild populations in Hawaii (USA) and from a captive population from California (USA), during the period between 1994 and 1996. Statistical analysis did not detect an influence of disease in any of the blood parameters for free-ranging turtles; however, captive turtles in Hawaii with GTFP had significantly higher levels of alkaline phosphatase and significantly lower levels of lactate compared to non-tumored captive turtles. Multivariate analysis found that biochemical profiles could be used to accurately predict if turtles were healthy or afflicted with GTFP. Discriminant function analysis correctly classified turtles as being with or without GTFP in 89% of cases, suggesting that diseased animals had a distinct signature of plasma biochemistries. Measurements of blood parameters identified numerous differences between captive and wild green turtles in Hawaii. Levels of corticosterone, lactate, triglyceride, glucose, and calcium were significantly higher in wild green turtles as compared to captive turtles, while uric acid levels were significantly lower in wild turtles as compared to captive turtles. Additionally, turtles from Sea World of California (San Diego, California, USA), which had been in captivity the longest, had higher levels of alanine aminotransferase and triglycerides as compared to nearly all other groups. Differences in diet, sampling methods, environmental conditions, and turtle size, help to interpret these results.

Primary lung neoplasia in a beagle colony

As part of long-term pulmonary carcinogenesis studies in dogs, it is important to analyze the incidence of spontaneous lung neoplasia. Primary lung carcinoma incidence was determined in two control populations of Beagle dogs observed for their life spans. One population comprised 216 dogs (112 males and 104 females) that were controls for life span studies, and another comprised 182 dogs (50 males and 132 females) that were retirees from a breeding colony. Forty lung neoplasms were noted in the 398 dogs; 35 neoplasms were carcinomas classified as papillary adenocarcinoma (20), bronchioloalveolar carcinoma (9), adenosquamous carcinoma (5), or bronchial gland carcinoma (1). The other five neoplasms were a malignant fibrous histiocytoma, three adenomas, and a fibroma. The crude incidence of lung carcinomas averaged for both populations was 8.8% (35/398) and was dominated by a relatively high incidence of lung neoplasia in aged dogs, those dying after the median life span of 13.6 years.