Three-dimensional hydrogel culture systems support growth and determination of chemosensitivity of feline sarcoma and carcinoma cell lines.

OBJECTIVE: To evaluate feline injection site-associated sarcoma (FISAS) and oral squamous cell carcinoma (FOSCC) cells in 3-D hydrogel-based cell cultures to determine chemosensitivity to carboplatin at concentrations comparable to those eluted from carboplatin-impregnated calcium sulfate hemihydrate (C-ICSH) beads. SAMPLE: 2 immortalized cell lines, each from a histologically confirmed primary FISAS and FOSCC. PROCEDURES: Hydrogels (10% wt/vol) were formed via UV exposure from methacrylamide-functionalized gelatin dissolved in PBSS. For each cell line, approximately 100,000 cells were encapsulated per hydrogel. Three cell-seeded 3-D hydrogels were evaluated for each carboplatin concentration (0, 150, 300, 450, and 600 µM) across 3 experiments. Drug efficacy was assessed by luminescence assay 72 hours after treatment. Growth of tumor cells treated with 300 µM or 600 µM carboplatin was evaluated using live-cell morphology imaging and confocal microscopy at 3, 7, and 14 days after treatment. RESULTS: Mean half-maximal inhibitory concentration (IC50) values for FISAS and FOSCC cells ranged from 123 to 171 µM and 155 to 190 µM, respectively, based on luminescence assay. Viability at 3, 7, and 14 days for both cell lines at 300 µM carboplatin was 50%, 25%, and 5% and at 600 µM carboplatin was 25%, 10%, and < 5%. CLINICAL RELEVANCE: 3-D hydrogel cell culture systems supported growth of feline tumor cells for determination of in vitro chemosensitivity. IC50s of each cell line were within the range of carboplatin concentrations eluted from C-ICSH beads. Cells from FISAS and FOSCC cell lines treated with carboplatin showed dose-dependent and time-dependent decreases in viability.

Three-dimensional hydrogel culture systems support growth and determination of chemosensitivity of feline sarcoma and carcinoma cell lines.

OBJECTIVE: To evaluate feline injection site-associated sarcoma (FISAS) and oral squamous cell carcinoma (FOSCC) cells in 3-D hydrogel-based cell cultures to determine chemosensitivity to carboplatin at concentrations comparable to those eluted from carboplatin-impregnated calcium sulfate hemihydrate (C-ICSH) beads. SAMPLE: 2 immortalized cell lines, each from a histologically confirmed primary FISAS and FOSCC. PROCEDURES: Hydrogels (10% wt/vol) were formed via UV exposure from methacrylamide-functionalized gelatin dissolved in PBSS. For each cell line, approximately 100,000 cells were encapsulated per hydrogel. Three cell-seeded 3-D hydrogels were evaluated for each carboplatin concentration (0, 150, 300, 450, and 600 µM) across 3 experiments. Drug efficacy was assessed by luminescence assay 72 hours after treatment. Growth of tumor cells treated with 300 µM or 600 µM carboplatin was evaluated using live-cell morphology imaging and confocal microscopy at 3, 7, and 14 days after treatment. RESULTS: Mean half-maximal inhibitory concentration (IC50) values for FISAS and FOSCC cells ranged from 123 to 171 µM and 155 to 190 µM, respectively, based on luminescence assay. Viability at 3, 7, and 14 days for both cell lines at 300 µM carboplatin was 50%, 25%, and 5% and at 600 µM carboplatin was 25%, 10%, and < 5%. CLINICAL RELEVANCE: 3-D hydrogel cell culture systems supported growth of feline tumor cells for determination of in vitro chemosensitivity. IC50s of each cell line were within the range of carboplatin concentrations eluted from C-ICSH beads. Cells from FISAS and FOSCC cell lines treated with carboplatin showed dose-dependent and time-dependent decreases in viability.

Outcome in dogs undergoing adrenalectomy for small adrenal gland tumours without vascular invasion.

Veterinary studies have reported the outcome of adrenalectomies in dogs; however, these studies typically include a wide variety of adrenal tumour sizes, including cases with or without vascular invasion. The purpose of this study was to report outcome in a cohort of dogs with histologically confirmed small adrenal tumours without vascular invasion treated with adrenalectomy. This retrospective study was conducted using data from the University of Florida and University of California-Davis databases between 2010 and 2017. Dogs were included if they underwent excision of an adrenal gland tumour with a maximal diameter ≤ 3 cm, without evidence of vascular invasion to any location as assessed via computed tomography. Fifty-one dogs met the inclusion criteria. The short-term survival rate of dogs undergoing adrenalectomy was 92.2%, and one-year disease-specific survival was 83.3%. Twenty-eight of 51 (54.9%) dogs were diagnosed with a malignancy. Minor complications were observed commonly intra-operatively and post-operatively. Major complications were observed in six dogs, and included sudden death, respiratory arrest, acute kidney injury, haemorrhage, hypotension and aspiration pneumonia. Short-term mortality occurred in four dogs. Sudden death and haemorrhage were the most common major complications leading to death. While adrenalectomy is sometimes controversial because of the high perioperative mortality rates previously reported, the results of this study support that adrenalectomy for small tumours with no vascular invasion can be performed with low risk.

Intra-articular proximal jig pin placement during tibial plateau leveling osteotomy.

Background: During tibial plateau leveling osteotomy (TPLO), a TPLO jig is often used. For placement of the jig, one of the pins is placed slightly distal to the joint line. Erroneous pin placement may lead to intra-articular damage; however, the path of the pin tract has not been thoroughly investigated. Aim: To document the rate and identify potential risk factors of intra-articular jig pin placement in dogs undergoing TPLO with the use of a TPLO jig. Methods: Medical records and pre- and postoperative radiographs (2007-2017) of 696 dogs with TPLO performed with a jig were reviewed. Primary surgeon and tibial plateau angles (TPA) were recorded. Postoperative radiographs were evaluated and classified according to intra-articular jig pin placement. Medial tibial plateau jig pin placement was defined as a radiolucent tract on the osteochondral junction of the medial tibial plateau. Lateral tibial plateau placement was defined as a radiolucent tract within 3 mm of the medial tibial plateau with a pin trajectory penetrating the lateral tibial plateau. Rates of intra-articular jig pin placement were calculated, and associations between intra-articular jig pin placement and surgeon experience and TPA were assessed with a chi-squared test. Results: Thirty-seven (5.32%) dogs had intra-articular placement of the jig pin. Seven dogs had medial tibial plateau jig placement, and 30 had lateral tibial plateau placement. There was no relationship between the TPA or surgeon level of experience and intra-articular placement of the pin. Conclusion: This study serves as a reminder to be cautious when placing the proximal jig pin during TPLO to avoid intra-articular placement. In addition, guidelines for evaluating proximal jig pin placement on postoperative radiographs are provided.

Limb-shortening limb salvage (LSLS) in a cat with metatarsal osteosarcoma.

The objective of this report was to document a successful partial limb amputation surgery in a cat with metatarsal osteosarcoma (OSA) including the use of pad grafts from the amputated foot. Limb shortening of the hindlimb through a partial amputation resulted in excellent limb function and usage. The patient retained functional use of the limb after surgery, with no lameness. There was no evidence of metastasis or local recurrence seen 323 days post-surgery. Limb shortening partial amputation is a reasonable option and can result in excellent limb use after surgery despite a significant loss in limb length.

Intervention pour raccourcir et sauver un membre chez un chat atteint d'un ostéosarcome métatarsien. L'objectif du présent rapport consistait à documenter une chirurgie d'amputation partielle réussie chez un chat atteint d'un ostéosarcome métatarsien y compris l'usage de greffes des coussinets du pied amputé. Le raccourcissement du membre postérieur par une amputation partielle a donné d'excellents résultats pour la fonction et l'usage du membre. Le patient a conservé l'usage fonctionnel du membre après la chirurgie, sans boiterie. Il n'y avait aucun signe de métastase ni de récurrence locale lors d'un examen 323 jours après la chirurgie. L'amputation partielle et le raccourcissement du membre sont une option raisonnable et peuvent produire une excellente utilisation du membre après la chirurgie malgré une perte importante de la longueur du membre.(Traduit par Isabelle Vallières).

Reverse Saphenous Conduit Flap in 19 Dogs and 1 Cat.

The purpose of this retrospective study was to report the outcomes of 19 dogs and 1 cat undergoing reverse saphenous conduit flap between 1999 and 2016. Reverse saphenous conduit flap was used to treat traumatic wounds and wounds resulting from tumor excision in the hind limb; the majority of cases had medial shearing injuries. All animals had complete flap survival. In five animals (20%), minor donor site dehiscence occurred, which did not require surgery. Other postoperative complications included signs of severe venous congestion in one dog. Reverse saphenous conduit flap is a useful technique to repair skin defects of the distal hind limb.

Skin depigmentation associated with toceranib phosphate in a dog.

BACKGROUND: Drug-induced depigmentation is frequently observed in humans undergoing tyrosine kinase inhibitor therapy, whereas it is not reported in dogs. The skin depigmentation can occur after the first week of treatment and it is reversible within a few weeks after drug discontinuation. OBJECTIVES: To report the clinical and histopathological features of an episode of cutaneous adverse drug reaction associated with short term administration of toceranib phosphate. CASE REPORT: An 11-year-old intact male Bernese mountain dog was presented for investigation of a subcutaneous mast cell tumour (MCT) including treatment options. The major abnormality on physical examination was a 7.5 × 10 cm subcutaneous mass located cranial to the left shoulder joint consistent with a MCT. Toceranib phosphate therapy was initiated. Fourteen days after initiating treatment, the dog presented with skin erosions near the lateral canthus of the left eye. Three weeks later there were multiple skin lesions characterized by alopecia and depigmentation involving left and right eyelids; leukotrichia of the periorbital areas and depigmentation of the nasal planum and all paw pads. Histopathological findings were nonspecific; they were supportive of vitiligo. Resolution of skin lesions was observed after stopping the toceranib phosphate therapy. CONCLUSION AND CLINICAL IMPORTANCE: Based on the gross lesions, histopathological features before and after tyrosine kinase inhibitor therapy, and Naranjo score, this case was considered to be consistent with cutaneous adverse drug effects. To the best of the authors' knowledge, this is the first report describing the clinical and histopathological features of presumed drug-induced skin depigmentation in a dog receiving toceranib phosphate.