Tumor venéreo transmissível canino com resistência quimioterápica e metástase esplênica. Relato de caso / Canine transmissible venereal tumor with chemotherapy resistance and splenic metastasis. Case report

RESUMO O Tumor Venéreo Transmissível Canino (TVTC) é uma neoplasia de células redondas que tem a particularidade de se implantar em mucosas que tenham perdido a sua integridade. Nesse local o tumor prolifera e ocasionalmente origina metástase. Em geral, o tumor responde ao tratamento com sulfato de vincristina, porém a resistência quimioterápica associada ao fenótipo tumoral tem sido documentada. Objetivou-se relatar um caso de TVTC genital de fenótipo citológico misto com metástase esplênica e o insucesso da quimioterapia com sulfato de vincristina, em uma fêmea canina, da raça Australian Cattle Dog, de cinco anos de idade. Após diagnóstico citológico e histológico, o tumor primário foi ainda caracterizado em fase de progressão e mostrou baixa expressão de moléculas do complexo principal de histocompatibilidade (MHC) (4,4 ± 2% classe I e 11 ± 4,1% classe II). A cadela foi submetida à ovariohisterectomia e esplenectomia terapêutica e não apresentou recidiva do tumor após 12 meses de acompanhamento clínico.

ABSTRACT The canine transmissible venereal tumor is a type of round cell cancer that have the particularity of implanting in mucous tissue, when they lose their integrity, at which point the tumour proliferates and may even develop metastases. The tumor typically responds well to vincristine sulfate chemotherapy, although there are cases of resistance to the drug correlated with the tumoral phenotype. We describe herein a genital mixed TVTC case with metastases at spleen and failure at vincristine sulfate chemotherapeutic treatment in a five years old Australian Cattle Dog female. After the cytological, histological and cytogenetic diagnostic, the primary tumor was still characterized in progression phase and showed low major histocompatibility complex expression MHC (4,4 ± 2% class I e 11 ± 4,1% class II. The dog underwent therapeutic splenectomy and ovariohysterectomy and did not present tumor recurrence within 12 months of clinical follow-up.

Protocols using detomidine and oxytocin induce ex copula ejaculation in stallions.

Tricyclic antidepressives, such as imipramine, indirectly induce ejaculation by increasing the noradrenaline concentration, which triggers an α-adrenergic response, whereas α-adrenergic agonists, such as xylazine and detomidine, directly trigger ejaculation by activating the α-1 adrenergic receptors. Furthermore, serum oxytocin concentrations in stallions increase drastically before ejaculation, but decline immediately thereafter, implicating the role of this hormone in emission. The objectives of the present study were to: 1) compare the efficiency of various protocols for inducing ex copula ejaculation in stallions, 2) evaluate the benefits of including oxytocin in the protocols, and 3) compare the semen characteristics of ex copula versus in copula ejaculates. Nine protocols were used to induce ex copula ejaculation using various combinations of xylazine (X; 0.66 mg/kg, iv); oxytocin (O; 20 IU, iv), imipramine (I; 3 mg/kg, orally), and detomidine (D; 0.02 mg/kg, iv). Imipramine was given 2 h prior to the administration of α-adrenergic agonist (detomidine or xylazine) and oxytocin. If ejaculation did not occur within 10 min after treatment with an α-adrenergic agonist, a half-dose of the same product was injected. Twelve sexually mature stallions (6-26 y) were used; 9 of 12 stallions responded to the treatment. Two stallions responded to X or XO, four stallions responded to IX and IXO, one stallion responded to DO, and five responded to IDO. Stallions that responded to detomidine did not respond to xylazine. No stallion ejaculated in response to D, ID, or IO. Erections and masturbation occurred only in imipramine-treated stallions. Sperm quality was similar among all the protocols and was not significantly different from those in in copula ejaculates collected with an artificial vagina. In a separate trial, none of these protocols induced ex copula ejaculation in 2-3 y old stallions. The side effects included sialorrhea after imipramine administration in all the stallions and sedation after administration of xylazine or detomidine. In conclusion, the new protocol, IDO, and the traditional protocol, IX, had similar results, with IDO being a useful alternative protocol in stallions for which IX was not effective. Therefore, attempts using both the protocols are encouraged, as stallions that ejaculated upon administration of detomidine did not ejaculate when xylazine was administered, whereas those that responded to xylazine did not respond to detomidine.

Effects of experimental amitraz intoxication in cats

This work studied the effects of experimental amitraz intoxication in cats. Sixteen cats were randomly divided equally into two groups: amitraz group - animals received 1.5 percent amitraz at 1mg/kg IV; and the control group - animals without amitraz. Physiological parameters from blood, cardiorespiratory system, and sedation indicators were quantified over time up to 360 minutes. Blood profile, urea, creatinine, alananine aminotransferase and aspartate aminotransferase were not affected by amitraz. Sedation, loss of reflexes, hypothermia, bradycardia, bradyarrhythmia, hypotension, bradypnea, mydriasis, besides transitory hyperglycemia, hypoinsulinemia and decrease of cortisol levels were observed in cats experimentally exposed to amitraz. The alpha2-adrenergic effects induced by amitraz intoxication in cats are very similar to the same effects reported in others species, contributing with more information about this type of intoxication to veterinary toxicology

Este trabalho estudou os efeitos da intoxicação experimental por amitraz em 16 gatos, distribuídos, aleatoriamente, em dois grupos: grupo amitraz - animais receberam amitraz a 1,5 por cento na dose de 1,0 mg/kg IV; e grupo controle - animais sem amitraz. Parâmetros fisiológicos sangüíneos, do sistema cardiorespiratório e de sedação foram aferidos até 360min. Perfil sangüíneo, uréia, creatinina, alanina aminotransferase e aspartato aminotransferase não foram afetados pelo amitraz. Sedação, perda de reflexos, hipotermia, bradicardia, bradiarritmias, hipotensão, bradipnéia, midríase, além de transitória hiperglicemia, hipoinsulinemia e diminuição dos níveis de cortisol, foram observados nos gatos experimentalmente expostos ao amitraz. Os efeitos alfa 2-adrenérgicos induzidos pela intoxicação por amitraz em gatos são muito similares aos mesmos efeitos relatados em outras espécies, contribuindo com mais informações dessa intoxicação para a toxicologia veterinária

Statin monotherapy attenuates renal injury in a salt-sensitive hypertension model of renal disease.

BACKGROUND: Several salutary biological effects of statins have been described. We sought to investigate more closely the anti-inflammatory and antiproliferative effects of simvastatin (SIMV) in a model of hypertension and progressive renal disease, as well as its effects on the cyclin-cdk inhibitors p21 and p27. METHODS: Munich-Wistar rats received the nitric oxide (NO) synthase inhibitor L-NAME (25 mg/kg/day p.o.) for 20 days accompanied by a high-salt diet (HS, 3% Na) and then were kept on HS for 60 days. Animals were then divided into two groups: vehicle (VH) or SIMV 2 mg/kg/day p.o. Albuminuria and tail-cuff pressure were determined at 30 and 60 days. RT-PCR was done to assess renal expression of TGF-beta1, collagen I and III, fibronectin, p27, p21 and monocyte chemoattractant protein-1 (MCP-1). Renal protein expression was assessed by Western blot (proliferating cell nuclear antigen (PCNA)) and immunostaining (macrophage, lymphocyte, PCNA). RESULTS: SIMV did not prevent the development of severe hypertension or albuminuria. SIMV-treated animals had less severe renal interstitial inflammation and cell proliferation. MCP-1 expression was significantly diminished in the SIMV-treated animals (55.4 +/- 7.3 vs. 84.4 +/- 8.2 OD, p = 0.02). mRNA renal expression for p27 and TGF-beta did not change between groups, but p21 mRNA renal expression, highly induced in this model, significantly decreased with SIMV treatment (31.6 +/- 6.6 vs. 50.2 +/- 5.8 OD, p < 0.05). The interstitial fibrosis score significantly decreased with SIMV (2.46 +/- 0.40 vs. 4.07 +/- 0.38%, p < 0.01), which was confirmed by a decrease in renal collagen I and fibronectin expression. Serum cholesterol level did not change with SIMV. CONCLUSION: SIMV attenuated interstitial fibrosis associated with this model of hypertensive renal disease. The mechanism involved MCP-1 downregulation. SIMV treatment was also associated with a p21 downregulation in the kidney, which might be involved in the protection of renal scarring.