Canine Transmissible Venereal Tumour Parasitized by Leishmania infantum

Veterinary Research Communications -     

Review of Canine Transmissible Venereal Sarcoma

Veterinary Research Communications -     

Canine transmissible venereal tumour: a review

Canine transmissible venereal tumour (CTVT) is a contagious venereal tumour of dogs, commonly observed in dogs that are in close contact with one another, or in stray and wild dogs that exhibit unrestrained sexual activity. CTVT represents a unique, naturally transmissible, contagious tumour, where the mutated tumour cell itself is the causative agent and perpetuates as a parasitic allograft in the host. Clinical history, signalment and cytological features are often obvious for establishing a diagnosis though biopsy and histological examination may be needed in atypical cases. Most cases are curable with three intravenous injections of vincristine sulphate at weekly intervals. The role of stray and wild dogs makes the disease difficult to control and necessitates sustained animal birth control in stray dogs along with prompt therapy of the affected dogs. This review captures the manifold developments in different areas embracing this fascinating tumour, including its biology, diagnosis and therapeutic alternatives.     

犬皮肤肥大细胞瘤的组织病理学诊断

犬皮肤肥大细胞瘤约占皮肤肿瘤的20%,因为占位小且不明显,所以是犬的癌症中非常严重的一种。有的切除后没什么后遗症,有的却能成为威胁生命的疾病。正确的鉴别和处置在控制本病方面显得尤为重要。为确诊一例犬皮肤肿物的类型,将病犬皮肤肿物制成石蜡切片,观察HE染色和TB染色结果,发现增多的肿瘤细胞具有肥大细胞典型的组织学和细胞形态学特征,确诊该肿瘤为犬皮肤的肥大细胞瘤。     

Clinical Pharmacokinetics and Effects of Vincristine Sulfate in Dogs with Transmissible Venereal Tumor (TVT)

This study was conducted to evaluate the pharmacokinetic characteristics of vincristine and their correlation with its clinical effects in dogs with transmissible venereal tumor (TVT). Dogs with TVT were intravenously administered vincristine sulfate at a dose of 0.7 mg/m² of body surface area. Blood samples were collected starting from 5 min to 48 hr after drug administration. The plasma concentration of vincristine was determined using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The pharmacokinetic parameters of vincristine were characterized using a two-compartmental pharmacokinetic model. The volume of distribution, distribution half-life, elimination half-life and plasma clearance were 0.660 ± 0.210 l/kg, 21.5 ± 6.90 min, 47.6 ± 14.2 min and 0.010 ± 0.001 l/min/kg, respectively. Tumor regression was determined at weekly interval by a physical examination and histopathological analysis. In our study, three to eight administrations of vincristine at a dose of 0.7 mg/m² were able to induce a complete tumor regression without any evidence of gross lesion of disease. Therefore, this investigation provides the pharmacokinetic characteristics of vincristine in dogs with TVT, which may be used as an integration tool to gain a better understanding of the disposition properties of the drug and the correlation of these properties with the drug’s clinical effects. In addition, we validated the LC-MS/MS method and found that it is suitable for the pharmacokinetic study of vincristine in dog plasma.     

应用分子靶点药物治疗犬肥大细胞瘤的研究进展

犬肥大细胞瘤因其恶性率和转移率都较高,并且常规化疗药物副作用较强,患犬生存期和生存质量显著下降,因此急需新型的药物进行治疗。近几年,治疗肿瘤的分子靶点药物凭借其疗效好、副作用低的特点,受到越来越广泛的关注,特别是在治疗犬肥大细胞瘤的应用中效果显著。论文重点介绍了欧美小动物临床最常用的伊马替尼、托赛拉尼、马赛替尼这3种以异常KIT为靶点的药物及其药物作用机理及药效,最后介绍了由c-kit基因二次突变所导致的耐药问题及其预防措施,期望能对我国小动物临床医师和科研工作者有所启发。     

Multivariate Survival Analysis of Histological Parameters and Clinical Presentation in Canine Cutaneous Mast Cell Tumours

The Patnaik histological grade is a good method for the prediction of long-term mast cell tumour behaviour but it is influenced by subjective inter-observer variations and intratumoral heterogeneity. The present study evaluated each of the histopathological parameters used to formulate Patnaik’s grade in terms of prognosis and tested whether they have a different prognostic sensitivity, thereby disclosing which could be considered more useful in the prediction of tumour recurrence and patient survival. Clinical presentation (single or multiple tumours) was also considered as possible prognostic factor. The results demonstrated that individual histological criteria together with multiple presentation may be of value in predicting the outcome of mast cell tumours. Among these, invasiveness (β1.85; standard error 1.15) and the number of mitotic figures (β3.01; standard error 1.18) showed high prognostic significance (Cox proportional hazard regression for censored data ; chi-squared = 15.52, degree of freedom = 6, p = 0.016) and could serve as reliable prognostic indicators avoiding more subjective parameters such as cellular differentiation, nuclear morphology and tumoural pattern. R. Preziosi Deceased     

Mast cell tumours (mastocytosis) in the horse: A review of the literature and report of 11 cases

Mast cell tumours are uncommon tumours in horses, compared to some other species of domesticated animals. They are most frequently located in the skin, but they can also arise at other sites, including the upper respiratory tract and eye. Cytology or histopathology is required for diagnosis. Treatment options include surgical excision, laser ablation, cryotherapy, intralesional injection of corticosteroids or water, and radiotherapy. Malignant and systemic forms are very rare.     

Treating canine atopic dermatitis with unsaturated fatty acids: the role of mast cells and potential mechanisms of action

Canine atopic dermatitis (CAD) is an inflammatory skin disorder that is characterized by pruritus and associated cutaneous changes. Treatment interventions include allergen avoidance, allergen‐specific immunotherapy as well as a symptomatic therapy using glucocorticoids and antihistamines. In addition, a dietary intervention using polyunsaturated fatty acids (PUFA) has been shown to alleviate symptoms in some dogs. Although the beneficial effects of PUFA in the treatment of CAD have been known for several years, their mode of action remains unclear. This review discusses the evidential basis of the therapeutic use of dietary PUFA in the treatment of CAD. Particular emphasis will be placed on the role of cutaneous mast cells. In addition, recent evidence from in vitro studies on the regulation of mast cell exocytosis will be used to build a mechanistic model of the active principle of PUFA. It is proposed that dietary PUFA are integrated into mast cell membranes resulting in a reorganization of membrane microdomains. This may then be accompanied by functional changes of membrane‐associated proteins such as the phospholipases D (PLD), enzymes having an important impact on mast cell exocytosis processes.