Hugo Pissarra

p63 and E-cadherin Expression in Canine Oral Squamous Cell Carcinoma:

The expression of p63 and E-cadherin was studied in 22 oral squamous cell carcinomas in the dog according to immunohistochemical techniques. The association between these markers and clinicopathologic parameters was assessed. All tumor cells studied showed enhanced p63 expression. Regarding E-cadherin expression, 17 of 22 cases (77.3%) showed decreased immunoreactivity, and in 13 of 22 cases (59.1%), its expression was cytoplasmic. Neither p63 nor E-cadherin expression patterns were associated with tumor size, bone invasion, or lymph node metastasis. p63 score was related to proliferating cell nuclear antigen proliferative index (P = .020). A statistically significant correlation between the expression patterns of these 2 markers was noted (P = .026). Furthermore, they were related with tumor grade. An atypical p63 labeling and a cytoplasmic E-cadherin staining were statistically related with a higher tumor grade (P = .022 and P = .017, respectively). These findings suggest that changes in p63 and E-cadherin expression are frequent events in oral squamous cell carcinoma in dogs.

Cryptococcal meningitis in a goat - a case report

BackgroundCryptococcus spp. are saprophytic and opportunistic fungal pathogens that are known to cause severe disease in immunocompromised animals. In goats there are reports of clinical cryptococcal pneumonia and mastitis but not of meningitis.Case presentationThe following report describes a case of a five year old buck showing severe neurological signs, including paraplegia and strong pain reaction to touch of the hindquarters region. Treatment with antibiotics was unsuccessful and the animal was euthanized for humanitarian reasons. Postmortem examination revealed lumbar meningitis, lung nodules and caseous lymphadenitis lesions. Encapsulated Cryptococcus neoformans were identified from the lungs and meninges, showing that cryptococcal meningitis should be included in the differential diagnosis of goats showing paresis and hyperesthesia. The possibility of concurrent immunosuppression due to Corynebacterium pseudotuberculosis infection is raised.ConclusionsCryptoccocal meningitis should be included in the differential diagnosis list of goat diseases with ataxia and hyperesthesia.

Successful treatment of feline leishmaniosis using a combination of allopurinol and N-methyl- glucamine antimoniate

Case summary This work describes the diagnosis and successful treatment of a 2-year-old domestic cat infected with Leishmania species and presenting fever, and ulcerative and nodular skin lesions after being treated for pyodermatitis for 1 year without clinical improvement. After anamnesis the cat was submitted to a complete clinical examination. Blood was collected for determination of haematological and biochemical parameters, detection of feline leukaemia virus (FeLV), feline immunodeficiency virus (FIV), feline coronavirus (FCoV) and Leishmania amastigotes. Fine-needle aspiration puncture from the skin nodules was also performed. After definitive diagnosis the animal was treated and followed up over a 2 year period. The animal tested negative for FIV-specific antibodies, FeLV antigen and feline coronavirus RNA. Leishmania amastigotes in the skin nodules were confirmed by cytology and molecular diagnosis. Treatment was initiated with allopurinol, resulting in a slight clinical improvement. Thus, N-methyl-glucamine antimoniate was added and administered for 30 days, with complete closure of the ulcerative lesions in the hindlimbs requiring a surgical approach. Close monitoring of the patient in the following 24 months indicated that combined therapy was safe and clinical cure was achieved without further relapses or side effects. Relevance and novel information Considering the increasing number of feline leishmaniosis cases and the inconsistent results of most therapeutic protocols described in the literature, the use of new approaches, especially in refractory cases, is essential. Although the use of allopurinol and N-methyl-glucamine antimoniate is off-label in cats, in this case the combination treatment was followed by an extensive analytical monitoring, supporting their safety and effectiveness.

SEVERE FIBRINONECROTIC ENTERITIS CAUSED BY PSEUDOMONAS AERUGINOSA IN A CAPTIVE MONITOR LIZARD (VARANUS NILOTICUS)

Abstract: Pseudomonas aeruginosa is an important pathogen that has been implicated in a number of serious conditions in humans and animals. Studies regarding the efficacy of antimicrobial drugs against virulent strains of P. aeruginosa in human and animal hosts have demonstrated that common therapeutic options are sometimes ineffective. In captive animals, in particular reptiles, literature on this topic is scarce. In this study, a 6-yr-old monitor lizard, Varanus niloticus, died suddenly without previous symptoms. Postmortem examination and bacteriologic analysis of necropsy samples revealed severe fibrinonecrotic enteritis caused by P. aeruginosa. The isolate presented a typical resistance profile, showing resistance to amoxycillin-clavulanic acid, ampicillin, cephotaxime, and sulphamethoxazole-trimethoprim. Virulence characterization demonstrated that the bacterium was able to express hemolysins, DNases, gelatinases, and lipases and had biofilm-forming ability. This study highlights the importance of surveillance for antimicrobial resistance and virulence traits in captive animals, which may present a challenge to practitioners.

Comparison of Histological and Proliferation Features of Canine Oral Squamous Cell Carcinoma Based on Intraoral Location: 36 Cases

Grade and labeling indices for immunohistochemical tumor proliferation markers Ki-67 and proliferating cell nuclear antigen (PCNA) were evaluated in 36 cases of canine oral squamous cell carcinoma (OSCC) based upon intraoral location. Grade was significantly associated with location (P = .035). Grade II tumors were most frequently diagnosed. Grade I tumors were identified in the gingiva and the buccal mucosa, and grade III tumors were seen in the gingiva and the tonsillar region. Animals with tumors arising from the tonsils and of the tongue tended to be older (P = .007), and those in the former group were more likely to have metastatic disease at the time of diagnosis (P = .001). Mean expression of PCNA and Ki-67 proliferation index (PI) for all tumors were 62.54% and 50.70%, respectively, and there was a statistical significant association between the 2 variables (R = .70; P < .001). Proliferation index was not associated with any of the intraoral locations evaluated, but higher PCNA PI was significantly associated with grade (P = .031). Ki-67 PI was significantly associated with lymph node metastasis at the time of diagnosis, especially for OSCC of gingival location (P = .028). The results obtained in this study are preliminary but clinically relevant, since they provide information that can explain differences in biologic behavior among intraoral locations and contribute to more accurate tumor staging to support the choice for different treatment strategies available for OSCC.

Delta-like 4/Notch signaling promotes Apc Min/+ tumor initiation through angiogenic and non-angiogenic related mechanisms

BackgroundDelta like 4 (Dll4)/Notch signaling is a key regulator of tumor angiogenesis. Additionally, the role of Dll4 has been studied on tumor stem cells. However, as these cells are implicated in tumor angiogenesis, it is conceivable that the effect of Dll4 on these cells may be a consequence of its angiogenic function. Our aim was to evaluate the expression and dissect the functions of Dll4 in the ApcMin/+ model of colorectal cancer.MethodsWe evaluated the protein expression pattern of Dll4 and other Notch members in the ApcMin/+ tumors relatively to the normal gut and compared endothelial-specific with ubiquitous Dll4 knockout mice on an ApcMin/+ background.ResultsAll Notch pathway members were present in the normal small and large intestine and in the adenomas of the same regions. Dll4, all Notch receptors and Hes1 expression seemed upregulated in the tumors, with some regional differences. The same members and Hes5, instead of Hes1, presented ectopic expression in the tumor parenchyma. Dll4 expression was most pronounced in the tumor cells but it was also present in the tumor blood vessels and in other stromal cells. Ubiquitous and endothelial-specific Dll4 deletion led to an equivalent reduction of tumor growth because of a similarly marked tumoral angiogenic phenotype promoting non-productive vasculature and consequently hypoxia and apoptosis. The ubiquitous Dll4 inhibition led to a stronger decrease of tumor multiplicity than the endothelial-specific deletion by further reducing tumor proliferation and tumor stem cell density through upregulation of the cyclin-dependent kinase inhibitors 1C and 1B and downregulation of Myc, Cyclin D1 and D2 independently of β-catenin activation. This phenotype was associated to the observed increased epithelial differentiation deviated towards the secretory lineages by Atoh1 and Klf4 upregulation only in the ubiquitous Dll4 mutants.ConclusionsDll4 seems to promote ApcMin/+ tumorigenesis through both angiogenic and non-angiogenic related mechanisms.

Amelanotic uveal cyst in a Yorkshire terrier dog.

The diagnostic challenge presented by an amelanotic uveal cyst with an atypical appearance in a 9-year-old Yorkshire terrier dog is reported. The dog was presented with a peculiar cystic neoformation adherent to the edge of the pupil of the right eye. The cyst wall was attached to the pupillary margin and it was bean-shaped, measuring approximately 4.5 × 2.5 mm. It was white in colour with several red striations and a small brown spot in the middle, which conferred on it a peculiar appearance. The cyst could not be transilluminated and partially impaired vision. Apart from that, the ophthalmic exam revealed no other abnormalities and the eye showed no signs of inflammation. Ocular ultrasound revealed the cystic nature of the neoformation. During paracentesis of the anterior chamber, the cyst was deflated and both the cyst wall and fluid were aspirated. The tissue obtained was sent for a histological examination and was considered as corresponding to a uveal cyst. The dog improved from the post-operative uveitis without any complication and after 24 months of follow-up showed no recurrences.

Late prostatic metastasis of an uveal melanoma in a miniature Schnauzer dog

This manuscript describes a previously unreported clinical case of canine uveal melanoma in a miniature Schnauzer dog with an unusual location of metastasis (prostate) and delayed occurrence (3 years after primary tumor diagnosis and enucleation). Immunohistochemical labeling of both tumors with Melan A, Ki‐67, and c‐kit added some valuable information.

CASE REPORT: Amelanotic uveal cyst in a Yorkshire terrier dog: atypical uveal cyst in a dog

The diagnostic challenge presented by an amelanotic uveal cyst with an atypical appearance in a 9-year-old Yorkshire terrier dog is reported. The dog was presented with a peculiar cystic neoformation adherent to the edge of the pupil of the right eye. The cyst wall was attached to the pupillary margin and it was bean-shaped, measuring approximately 4.5 × 2.5 mm. It was white in colour with several red striations and a small brown spot in the middle, which conferred on it a peculiar appearance. The cyst could not be transilluminated and partially impaired vision. Apart from that, the ophthalmic exam revealed no other abnormalities and the eye showed no signs of inflammation. Ocular ultrasound revealed the cystic nature of the neoformation. During paracentesis of the anterior chamber, the cyst was deflated and both the cyst wall and fluid were aspirated. The tissue obtained was sent for a histological examination and was considered as corresponding to a uveal cyst. The dog improved from the post-operative uveitis without any complication and after 24 months of follow-up showed no recurrences.

CASE REPORT: Amelanotic uveal cyst in a Yorkshire terrier dog

The diagnostic challenge presented by an amelanotic uveal cyst with an atypical appearance in a 9-year-old Yorkshire terrier dog is reported. The dog was presented with a peculiar cystic neoformation adherent to the edge of the pupil of the right eye. The cyst wall was attached to the pupillary margin and it was bean-shaped, measuring approximately 4.5 × 2.5 mm. It was white in colour with several red striations and a small brown spot in the middle, which conferred on it a peculiar appearance. The cyst could not be transilluminated and partially impaired vision. Apart from that, the ophthalmic exam revealed no other abnormalities and the eye showed no signs of inflammation. Ocular ultrasound revealed the cystic nature of the neoformation. During paracentesis of the anterior chamber, the cyst was deflated and both the cyst wall and fluid were aspirated. The tissue obtained was sent for a histological examination and was considered as corresponding to a uveal cyst. The dog improved from the post-operative uveitis without any complication and after 24 months of follow-up showed no recurrences.