Glomerular lipidosis accompanied by renal tubular oxalosis in wild and laboratory-reared Japanese rock ptarmigans (Lagopus mutus japonicus)

Glomerular lipidosis is a disease characterized by lipid accumulation in mesangial cells but that has not been fully investigated in avian species. We examined four wild and two laboratory-reared Japanese rock ptarmigans (Lagopus mutus japonicus)--an endangered avian species--presenting vacuolar deposits in the glomeruli. All cases had vacuolar deposits in the glomeruli. In the wild cases, fewer than 30% of all glomeruli were affected, compared with more than 90% in the laboratory-reared cases. In the wild cases, most deposits were mild and restricted to the mesangial areas of glomeruli. In the laboratory-reared cases, nearly all of the deposits covered entire glomeruli. Electron microscopy of mild deposits revealed vacuoles in the cytoplasm of mesangial cells. These vacuoles were positive for Sudan III, Sudan black B, oil red O, Nile blue, periodic acid-Schiff, Schultz test, and digitonin stain and were negative for performaric acid-Schiff stains. Based on these results, we diagnosed the glomerular lesion as glomerular lipidosis caused by uptake of low-density lipoprotein in mesangial cells. Except for one wild case, all cases exhibited renal tubular oxalosis. The severity of tubular oxalosis tended to be related to the severity of glomerular lipidosis: In cases of mild glomerular lipidosis, tubular oxalosis was also mild or absent. We therefore diagnosed the primary lesion as glomerular lipidosis accompanied by tubular oxalosis. The four wild cases came from different zones and therefore had no opportunities to interbreed and no common relatives. We believe these data support the hypothesis that glomerular lipidosis is a disease of the general population ofJapanese rock ptarmigans. This is the first report of glomerular lipidosis accompanied by renal tubular oxalosis in an avian species.

Orbital embryonal rhabdomyosarcoma with metastasis in a young dog

A 2-year-old male Welsh corgi dog was brought to an animal hospital because of left upper eyelid enlargement with lachrymal gland protrusion. The lachrymal and orbital cavity mass was removed surgically. Microscopically, the orbital mass consisted of a mixture of large rhabdomyoblastic and small round tumour cells. Immunohistochemically, the rhabdomyoblastic cells expressed desmin and myoglobin and the small round cells expressed desmin, myogenin and MyoD1. A diagnosis of embryonal rhabdomyosarcoma (ERS) was made. One month later, multiple masses throughout the body were identified, in particular around the cervical region. One of these lesions was sampled and diagnosed as metastatic ERS. The dog died 84 days after the time of first admission.

Pulmonary zygomycosis with Cunninghamella bertholletiae in a killer whale (Orcinus orca)

An adult female killer whale (Orcinus orca) was transported to the Port of Nagoya public aquarium in June 2010. While the animal was being maintained in the aquarium there was a gradual decrease in body weight. On October 1st, 2010 the whale exhibited signs of gastrointestinal disease and died on January 14th, 2011. At necropsy examination the gastric compartments were filled with a large number of variably-sized rocks (total weight 81.4 kg) and there was marked ulceration in the third compartment. There were multifocal tubercle-like nodules within the lungs and on sectioning there were numerous abscesses and pulmonary cavities. Microscopically, there was severe suppurative pneumonia associated with fungal hyphae that were infrequently septate and often branched. Numerous bacterial colonies were also present. The hyphae demonstrated immunohistochemical cross-reactivity with Rhizomucor spp. and Cunninghamella bertholletiae was cultured. Bacteriological culture revealed the presence of Proteus mirabilis, Pseudomonas aeruginosa and Pseudomonas oryzihabitans. This case represents the first documentation of zygomycosis associated with C. bertholletiae in a marine mammal.

Disseminated mycosis in a killer whale (Orcinus orca)

Hematological findings in a female killer whale ( Orcinus orca) undergoing rehabilitation after sudden severe anorexia revealed continuing increases in serum lactate dehydrogenase and aspartate aminotransferase activities as well as fibrinogen concentration. Serologic evidence of herpesvirus infection and skin vesicles were detected 2 weeks into the treatment regimen of antibiotics and corticosteroids. The whale showed signs of improvement after treatment with anti-herpesvirus drugs, but sudden severe anorexia reappeared, along with marked elevation of fibrinogen concentration that continued until the death. Postmortem examination revealed multiple light tan foci of necrosis in the skeletal and cardiac muscles, and lung consolidation. Microscopic findings indicated disseminated fungal granulomas in the skeletal and cardiac muscles, as well as myocarditis, mycotic embolic thromboarteritis of cardiac blood vessels, and bronchopneumonia with numerous typical Aspergillus-like fungi. Mucor-like structures in granulomas in the heart and skeletal muscle and Aspergillus-like fungi in the lungs were identified using periodic acid–Schiff, Gomori methenamine silver stain, and immunohistochemistry. The present case involves dual infection with Mucor and Aspergillus species in a killer whale with concurrent herpesvirus.

Ganglioneuroma in the small intestine of a juvenile pig

A mass was located in the small intestine of a slaughtered 6-month-old male Landrace-cross pig that had no clinical abnormalities. This egg-shaped well-circumscribed mass was situated in the submucosal and muscular tissue layers and protruded into the lumen. Histopathologically, the tumor comprised discrete or aggregated ganglion and schwannian cells in neuropil-like tissue. Some ganglion cells contained Nissl substance in their cytoplasm. The ganglion cells stained positive for neuron-specific enolase, class III β-tubulin, neurofilament, and synaptophysin; the schwannian cells stained positive for vimentin, S-100 protein, and glial fibrillary acidic protein. The tumor was diagnosed as a ganglioneuroma in accordance with these findings. Here, we have reported detailed immunohistochemical findings in addition to the histopathological features of a swine ganglioneuroma.

Molecular genetic and pathogenic characterization of psittacid herpesvirus type 1 isolated from a captive galah (Eolophus roseicapillus) in Japan

Psittacid herpesvirus type 1 (PsHV-1) was isolated from a captive galah (Eolophus roseicapillus) in Japan that was suspected of having Pacheco's disease (PD), an acute fatal disease in psittacine birds. PsHV-1 has been classified into four genotypes based on the UL16 gene sequence. In the present study, we investigated the genetic and pathogenic characteristics of the isolated virus, FOY-1, compared with a reference strain, RSL-1. The FOY-1 strain was classified into PsHV-1 genotype 2. The FOY-1 strain was found to be less pathogenic to budgerigars than RSL-1, which was classified as genotype 4 in an in vivo study. This is the first report regarding the classification of originally isolated PsHV-1 in Japan and its characterization by animal infection experiment.

Site-specific in vivo mutagenicity in the kidney of gpt delta rats given a carcinogenic dose of ochratoxin A

Ochratoxin A (OTA) can induce renal tumors that originate from the S3 segment of the proximal tubules in rodents, but the results of conventional mutagenicity tests have caused controversy regarding the role of genotoxic mechanisms in the carcinogenesis. Human exposure to OTA from various foods is unavoidable. Therefore, an understanding of OTA-induced renal carcinogenesis is necessary for accurate estimates of the human risk hazard. In the present study, a 13-week exposure of gpt delta rats to OTA at a carcinogenic dose induced karyomegaly and apoptosis at the outer stripe of the outer medulla (OM) of the kidney but failed to affect the reporter gene mutations in DNA extracted from whole kidneys. This site specificity resulting from the kinetics of specific transporters might be responsible for the negative outcome of in vivo mutagenicity. The kidney was then macroscopically divided, based on anatomical characteristics, into the cortex, the OM, and the inner medulla, each of which was histopathologically confirmed. Spi⁻ mutant frequencies (MFs) but not gpt MFs in the OM after a 4-week exposure to OTA were significantly higher than in controls despite the absence of cortical changes. There were also no changes in 8-hydroxydeoxyguanosine levels in kidney DNA. These results strongly suggest the involvement of a genotoxic mechanism, with the exception of oxidative DNA damage in OTA-induced renal carcinogenesis. In addition, the reporter gene mutation assay using DNA from target sites could be a more powerful tool to investigate in vivo genotoxicities.

Cynomolgus monkeys (Macaca fascicularis) may not become infected with equine herpesvirus 9

BACKGROUND

It was suggested that Equine herpesvirus 9 (EHV-9) could be transmitted to higher non-human primates.

METHODS

Four cynomolgus monkeys (Macaca fascicularis) were inoculated with EHV-9 by the nasal route.

RESULTS

No abnormalities were observed pathologically, immunohistochemically, and genetically.

CONCLUSIONS

These findings indicate that cynomolgus monkeys are not susceptible to EHV-9.

A study of lesions induced in Seriola dumerili infected naturally with Streptococcus dysgalactiae

An outbreak of disease in Seriola dumerili occurred from August to October in 2007 and 2008. The fish developed lesions of the caudal peduncle, pectoral and/or dorsal fin and the heart. The lesions were characterized by moderate to severe infarction with areas of microabscessation and multifocal granulomatous inflammation associated with the presence of Streptococcus dysgalactiae antigen. This is the first report to describe the immunohistology of the lesions induced in S. dumerili following natural infection with S. dysgalactiae.

Prophylactic administration of epinephrine in oxaliplatin-related hypersensitivity reaction

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Background: Alongside disease progression or neurotoxicity, oxaliplatin-related hypersensitivity reaction is a common reason for treatment discontinuation and remains a critical issue. It is unclear whether prophylactic administration of epinephrine to patients with this severe hypersensitivity reaction is effective and safe.

Methods: We retrospectively reviewed 839 consecutive colorectal cancer patients treated with oxaliplatin-containing regimens at our hospital between April 2005 and March 2010. The medical records of those patients who had received prophylactic epinephrine (1:1000 solution) were examined. Hypersensitivity reaction was graded according to CTCAE version 3.0.

Results: Twelve patients (8 male and 4 female; median age, 66 years) had received prophylactic epinephrine. The hypersensitivity reaction, even though the patients were receiving prophylactic corticosteroid and antihistamine drugs, was grade 0/1/2/3 = 0/0/10/2. The median number of epinephrine doses administered was 6 (range, 1 to 21). The worst grade of hypersensitivity for rechallenge with oxaliplatin under prophylactic administration of epinephrine was grade 0/1/2/3 = 4/3/4/1. Reasons for treatment discontinuation were disease progression in 10 patients and neurotoxicity in one patient. The remaining one patient developed grade 3 hypersensitivity reaction during 4 cycles of treatment under prophylactic administration of epinephrine, but the reaction subsided after additional administration of epinephrine and corticosteroid. Common adverse events with administration of epinephrine were hypertension (4 patients), palpitation (3 patients) and headache, dizziness, fatigue, and bladder pain (1 patient each).

Conclusions: Prophylactic administration of epinephrine may be effective and tolerated in patients with moderate to severe oxaliplatin-related hypersensitivity reaction.

No significant financial relationships to disclose.

Experimental intranasal infection of equine herpesvirus 9 (EHV-9) in suckling hamsters: kinetics of viral transmission and inflammation in the nasal cavity and brain

Equine herpesvirus 9 (EHV-9), the newest member of the equine herpesvirus family, is a highly neurotropic herpesvirus that induces encephalitis in a variety of animals. To access transmission of EHV-9 in the nasal cavity and brain, a suckling hamster model was developed so that precise sagittal sections of nasal and cranial cavities including the brain could be processed, which proved useful in detecting viral transmission as well as extension of pathological lesions. Suckling hamsters were inoculated intranasally with EHV-9, and were sacrificed at 6, 12, 18, 24, 36, 48, and 60 h post inoculation (PI). Sagittal sections of the entire head, including nasal and cranial cavities including the brain, were made to assess viral kinetics and identify the progress of the neuropathological lesions. At 12 to 24 h PI the virus attached to and propagated in the olfactory epithelium, and infected adjacent epithelial cells. At 48 h PI, immunohistochemistry for EHV-9 viral antigen showed that virus had extended from the site of infection into the olfactory bulb and olfactory nerve. These results indicate that EHV-9 rapidly invades the brain via the olfactory route after experimental intranasal infection.

Effects of equine herpesvirus-9 infection in pregnant mice and hamsters

The pathogenicity of equine herpesvirus (EHV)-9, a new neurotropic equine herpesvirus isolated from gazelles, was assessed in pregnant rodents (mice and hamsters) following intranasal inoculation. The pregnant female mice and hamsters were inoculated with EHV-9 in the early or late trimesters. The inoculated animals exhibited mild to severe neurological signs and gave birth to dead or undersized fetuses. All three mice and four hamsters inoculated in the first trimester had varying degrees of placental abnormality, characterized by markedly dilated maternal blood sinusoids, atrophy of the trophoblast cells and necrosis of the middle layer of the trophoblast. There was also endometrial blood vessel congestion and necrosis and disorganization of the fetal capillaries in the mice and hamsters inoculated in the last trimester. EHV-9 antigen was detected in the brain of dams and the lungs of the fetuses and in the middle of the trophoblast layer of the placenta in hamsters inoculated in the first trimester. The placental lesions were milder in mice than in the hamsters. The mice and hamsters inoculated in the last trimester had more prominent lesions than the animals inoculated in the first trimester. These results suggest that EHV-9 can cause the death of the fetus or abortion and that these events may be secondary to placental vascular compromise.

Joint distraction and movement for repair of articular cartilage in a rabbit model with subsequent weight-bearing

We have previously shown that joint distraction and movement with a hinged external fixation device for 12 weeks was useful for repairing a large articular cartilage defect in a rabbit model. We have now investigated the results after six months and one year. The device was applied to 16 rabbits who underwent resection of the articular cartilage and subchondral bone from the entire tibial plateau. In group A (nine rabbits) the device was applied for six months. In group B (seven rabbits) it was in place for six months, after which it was removed and the animals were allowed to move freely for an additional six months. The cartilage remained sound in all rabbits. The areas of type II collagen-positive staining and repaired soft tissue were larger in group B than in group A. These findings provide evidence of long-term persistence of repaired cartilage with this technique and that weight-bearing has a positive effect on the quality of the cartilage.

Study on the infectivity of equine herpesvirus 9 (EHV-9) by different routes of inoculation in hamsters

The infectivity and pathology of equine herpesvirus 9 (EHV-9), a new neurotropic equine herpesvirus isolated from gazelles, was studied in hamsters experimentally infected via nasal, ocular, oral, intravenous (IV), or peritoneal routes. Clinically, all animals inoculated by the nasal route and ~25% inoculated by the oral and peritoneal routes showed neurological signs on days 3, 6, and 9 postinoculation (PI), respectively. Neurological signs were not observed in animals administered EHV-9 by the IV and ocular routes. With the exception of animals administered EHV-9 by the IV route, all infected animals had lymphocytic meningoencephalitis. Although there were a number of differences in the severity and distribution of the lesions depending on the route of inoculation, the basic features of lymphocytic meningoencephalitis caused by EHV-9 were common. Lesions consisted of neuronal necrosis, perivascular aggregates of lymphocytes, plasma cells, and neutrophils, gliosis, intranuclear inclusion bodies, and diffuse lymphocytic infiltrates in the meninges. Viral antigen was detected in degenerated neurons in infected animals inoculated by the nasal, ocular, oral, and peritoneal routes. The distribution of EHV-9 antigen was somewhat dependent on inoculation route. There were no microscopic abnormalities or viral antigen in animals treated by the IV route. This study provides new data about experimental EHV-9 infection in hamsters through routes other than the IV route. These results suggest that in the animals infected by the oral, ocular, and peritoneal routes, EHV-9 might travel to the brain through nerves, other than by the olfactory route, after initial propagation at the site of viral entry.

Meningoencephalitis associated with Sarcocystis spp. in a free-living Japanese raccoon dog (Nyctereutes procyonoides viverrinus)

A free-living, young adult, male Japanese raccoon dog (Nyctereutes procyonoides viverrinus) was rescued in Gifu, Japan in March 2009. The animal was weak and emaciated with neurological signs that included head tilt, tremor and tic. The brain showed no gross abnormality at necropsy, but microscopically there was severe meningoencephalitis associated with protozoa, which were morphologically consistent with the asexual developmental stage of Sarcocystis spp. The protozoa were immunohistochemically negative for Toxoplasma gondii and Neospora caninum, but reacted weakly with antiserum specific for Sarcocystis cruzi. Analysis of the partial 18S rRNA gene sequence revealed that the protozoa were most closely related to an unidentified Sarcocystis species that was isolated from the white-fronted goose (Anser albifrons).

Avian poxvirus infection in a white-tailed sea eagle (Haliaeetus albicilla) in Japan

An adult female white-tailed sea eagle (Haliaeetus albicilla), over 12 years old, was found moribund and sent to the Wildlife Rescue Center in Kushiro, Japan. Grossly, the bird had multifocal yellow to black nodules in the beak, tongue, mucosa of the oral cavity, eyelids, and legs. Histologically, the cutaneous nodules revealed severe epidermal hyperplasia. The thickened epithelium, from prickle cell layer to horny layer, consisted of swollen keratinocytes containing frequent eosinophilic intra-cytoplasmic inclusions, Bollinger bodies. Ultrastructurally, the epidermal cells had cytoplasmic viral particles with characteristics of poxvirus. Furthermore, the 4b core gene sequence of an avian poxvirus was detected in a DNA sample prepared from the nodular lesions by polymerase chain reaction. The nucleotide sequence of the polymerase chain reaction product showed 78 to 95% similarities to the sequences of other avian poxviruses. Phylogenetic analysis showed that the sequence is clustered in clade A but distant from all the subclades previously reported. The results imply that it is a novel avian poxvirus. To our knowledge this is the first report of avian poxvirus infection in white-tailed sea eagles.

Changes in the gene expression and enzyme activity of hepatic cytochrome P450 in juvenile Sprague-Dawley rats

The developmental changes in the hepatic cytochrome P450 (CYP) content, mRNA expression of 12 hepatic CYP subtypes, and the enzyme activities of 5 hepatic CYP subfamilies in rats were investigated using non-treated male and female Sprague-Dawley rats of ages postnatal day (PD) 4, 16, 30 and 8 and 12 weeks. The hepatic proliferation kinetics was also determined by using the phospho-histone H3 (p-histon)-labeled hepatocyte index. The developmental changes in the enzyme activities of hepatic expression of CYP1A and CYP3A in rats were similar to those in humans, although there is no fetal-neonatal dominant CYP3A subtype in rat livers unlike human CYP3A7. On the other hand, the developmental pattern of expression of the CYP2C subfamily differed between humans and rats. Enzyme activity and mRNA expression of each hepatic CYP subtype in rats on PD 30 was similar to that after 8 weeks of age, except in the case of sex-dependent CYP subtypes. The p-histon-labeled hepatocyte index was approximately 10-fold higher in PD 30 rats than in 8-week-old rats. Therefore, the livers of juvenile rats, which have high hepatocellular proliferation activity and a sufficient amount of metabolic enzymes such as CYP, may be more sensitive to the cytotoxic and carcinogenic effects of chemicals than the livers of adult rats. Thus, our results on developmental difference of hepatic CYPs in juvenile rats are useful to identify underlying age-dependent susceptibility of chemical-induced toxicity, and to understand developmental change of chemical disposition.