Soft tissue sarcoma in dogs: A treatment review and a novel approach using electrochemotherapy in a case series

Canine soft tissue sarcomas (STSs) are locally invasive mesenchymal neoplasms. Electrochemotherapy (ECT) is an antitumour local ablative treatment that uses electric pulses to enhance the intracellular delivery of cytotoxic drugs. The aim of this retrospective study was to review the current treatment for STSs and to evaluate the efficacy and safety of ECT with bleomycin in canine STSs. Fifty‐two dogs with 54 STSs were included. Three groups were arranged: (a) ECT alone, (b) intra‐operative ECT and (c) adjuvant ECT. Signalment, tumour size, location, histological grade and margins and ECT parameters were collected. Recurrence rate (RR) and disease‐free interval (DFI) were calculated. Treatment toxicity was assessed using a 6‐point scale. STSs were mostly located on limbs (77.8%). Median tumour size was 4.3 cm (range 0.4‐17.0 cm). Most STSs were grade I (47.7%) and II (50.0%), and histological margins were incomplete in 94.5% of cases. Two complete remissions, one partial remission and one stable disease were recorded in group 1. Group 2 and 3 were similar for tumour location, size and grade, histological margins, treatment toxicity, pulse frequency and voltage. Moreover, RR and DFI were similar between group 2 and 3 (23% and 25%, 81.5 and 243 days, respectively). Local toxicity post ECT was mild (score ≤ 2) in 66.7% of cases. Higher toxicity score was associated with higher pulse voltage (1200 vs 1000 V/cm) (P = 0.0473). ECT coupled with bleomycin resulted safe and efficient in tumour local control and should be considered as an option for treatment of canine STSs.     

Tartrate resistant acid phosphatase as a marker for scale resorption in rainbow trout,Oncorhynchus mykiss: effects of estradiol-17β treatment and refeeding

In teleosts, a considerable part of the body calcium is found in the scales. Associated with the scales are osteoblasts and osteoclasts, and during periods of high calcium demand such as during sexual maturation or starvation, the scales can be resorbed and thereby act as an internal calcium reservoir. In mammalian bone tissue, the activity of an acid phosphatase (ACP) isoenzyme, tartrate resistant acid phosphatase (TRACP), can be used as a marker for osteoclastic activity. In the present study, an evaluation of TRACP as a marker for osteoclastic activity in teleost scales has been performed. ACP and TRACP was histologically localized at resorption sites around the edge of the scales as well as at resorption holes in the scales. The optimal conditions for biochemical measurements of ACP and TRACP activity were found to be pH 5.3, 10 mM paranitrophenylphosphate, incubated for 30 min at room temperature, and 10 mM tartrate added when required. Using TRACP as a marker, estradiol-17 (E₂) was found to increase the proportion of scales being resorbed, as well as the number and size of resorption sites per scale. Also, the scales of E₂-treated fish showed weaker staining for calcium. Together, the obtained data indicate that estradiol-17 induces osteoclastic activity in teleost scales, resulting in increased resorption of the scales. A period of refeeding following a period of starvation did not have detectable effects on the scale osteoclastic activity and scale resorption.