Retrospective study of 20 cats surgically treated for insulinoma.

OBJECTIVE: To report the clinical signs, histopathology results, and prognostic factors for outcomes following excision for feline insulinoma (INS). STUDY DESIGN: Retrospective study. SAMPLE POPULATION: Twenty client-owned cats. METHODS: Medical records from 2006 to 2020 were reviewed by Veterinary Society of Surgical Oncology members for cats with hypoglycemia resulting from INS, with surgical excision and follow up. Clinical signs and histopathology results were summarized. Factors potentially related to disease-free interval (DFI), disease-related death (DRD), and overall survival time (OST) were analyzed with a Cox proportional hazards regression analysis. RESULTS: All cats were hypoglycemic on presentation with neurologic signs in 18 out of 20 and inappropriate insulin levels in 12/13. Excision of insulinomas resulted in immediate euglycemia or hyperglycemia in 18 cats. Eighteen cats survived to hospital discharge. The median time to death or last postoperative follow up was 664 days (range: 2-1205 days). Prognostic factors included age at presentation (for DFI); time to postoperative euglycemia (for DRD); preoperative and postoperative serum blood glucose concentrations; metastasis at the time of surgery (DFI and DRD), and histopathologic tumor invasion (for OST). The median OST for all cats was 863 days. The 1-, 2- and 3-year survival rates were 75%, 51%, and 10%, respectively. CONCLUSION: Excision of insulinoma resulted in euglycemia or hyperglycemia in most cats. Negative prognostic factors included young age, low serum glucose concentrations, metastasis at time of surgery, tumor invasion, and shorter time to euglycemia. CLINICAL SIGNIFICANCE: Surgical excision resulted in survival times comparable to those of canine INS.

Intratumoral injection of holmium-166 microspheres as neoadjuvant therapy of soft tissue sarcomas in dogs.

Introduction: Minimally invasive microbrachytherapy is in development to treat solid tumors by intratumoral injection of (radioactive) holmium-166 (166Ho) microspheres (MS). A high local dose can be administered with minimal damage to surrounding tissue because of the short soft tissue penetration depth of 166Ho beta radiation. We aimed to prospectively evaluate the safety and efficacy of 166Ho microbrachytherapy in client-owned canine patients with soft tissue sarcomas (STS). Methods: We included seven dogs with STS not suitable for local excision due to tumor size and/or location. 166HoMS were suspended in a carrier fluid and multiple needle-injections were performed in predetermined tumor segments to maximize tumor coverage. Tumor response was evaluated using 3D caliper and CT measurements. Follow-up further included monitoring for potential side effects and registration of subsequent treatments and survival, until at least two years after treatment. Results: Delivered radioactive doses ranged from 70 to 969 Gy resulting in a mean tumor volume reduction of 49.0 ± 21.3% after 33 ± 25 days. Treatment-related side effects consisted of local necrosis (n = 1) and ulceration of the skin covering the tumor (n = 1), which resolved with basic wound care, and surgical excision of residual tumor, respectively. Residual tumor was surgically resected in six patients after 22-93 days. After a mean follow-up of 1,005 days, four patients were alive, two patients were euthanized because of unrelated causes, and one patient was euthanized because of disease progression after the owner(s) declined subsequent surgical treatment. Conclusion: 166Ho microbrachytherapy was a safe and effective neoadjuvant treatment option for canine patients with STS.

Case Report: Radioactive Holmium-166 Microspheres for the Intratumoral Treatment of a Canine Pituitary Tumor.

Introduction: In this case study, a client-owned dog with a large pituitary tumor was experimentally treated by intratumoral injection of radioactive holmium-166 microspheres (166HoMS), named 166Ho microbrachytherapy. To our knowledge, this is the first intracranial intratumoral treatment through needle injection of radioactive microspheres. Materials and Methods: A 10-year-old Jack Russell Terrier was referred to the Clinic for Companion Animal Health (Faculty of Veterinary Medicine, Utrecht University, The Netherlands) with behavioral changes, restlessness, stiff gait, and compulsive circling. MRI and CT showed a pituitary tumor with basisphenoid bone invasion and marked mass effect. The tumor measured 8.8 cm3 with a pituitary height-to-brain area (P/B) ratio of 1.86 cm-1 [pituitary height (cm) ×10/brain area (cm2)]. To reduce tumor volume and neurological signs, 166HoMS were administered in the tumor center by transsphenoidal CT-guided needle injections. Results: Two manual CT-guided injections were performed containing 0.6 ml of 166HoMS suspension in total. A total of 1097 MBq was delivered, resulting in a calculated average tumor dose of 1866 Gy. At 138 days after treatment, the tumor volume measured 5.3 cm3 with a P/B ratio of 1.41 cm-1, revealing a total tumor volume reduction of 40%. Debulking surgery was performed five months after 166HoMS treatment due to recurrent neurological signs. The patient was euthanized two weeks later at request of the owners. Histopathological analysis indicated a pituitary adenoma at time of treatment, with more malignant characteristics during debulking surgery. Conclusion: The 40% tumor volume reduction without evident severe periprocedural side effects demonstrated the feasibility of intracranial intratumoral 166HoMS treatment in this single dog.

Internal Tandem Duplication of Exon 8 of c-kit Is Associated With Longer Total Survival in Canine Cutaneous Mast Cell Tumors.

Canine cutaneous mast cell tumors (ccMCTs) have a highly variable biological behavior and accurate prognostication is essential for therapeutic intervention. Internal tandem duplications (ITD) of exon 11 are the most commonly detected c-kit mutation in ccMCTs and are associated with poor prognosis and increased cellular proliferation. The prognostic value of detecting mutations in other exons of c-kit has not been systematically examined. In this study, we analyzed the prognostic value of ITD mutations of exon 8 in c-kit of ccMCTs in comparison to ccMCTs with ITD mutations of exon 11 and ccMCTs without mutations of exon 8 or 11. The mutational status, histological grade, KIT expression pattern, Ki67 index, AgNOR (argyrophilic nucleolar organizing region) score, and Ag67 score were determined in 221 ccMCTs, and outcome was available for 101 dogs. ITD mutations of exon 8 were found in 73/221 (33%), of exon 11 in 100/221 (45%), and none of these mutations in 50/221 (22%) of ccMCTs. None of the dogs with mutations of exon 8 died due to suspected ccMCT-related cause, but 23% dogs with ccMCTs with mutations of exon 11 died due to suspected ccMCT-related cause. Prognostic parameters in ccMCTs with exon 11 mutations were commonly associated with a high proliferative activity and poor prognosis, while prognostic markers in ccMCTs with mutations of exon 8 had lower values similar to those observed in ccMCTs without mutations in exons 8 or 11 of c-kit. This study indicates that screening for ITD mutations in exon 8 in ccMCTs may be helpful to identify less aggressive ccMCTs and may be recommended as a supplementary prognostic test.

Influence of speaker's gender on speaker introductions at the 2018 ACVS Surgical Summit.

OBJECTIVE: To evaluate whether formality of introduction differed between male vs female speakers at the 2018 American College of Veterinary Surgeons (ACVS) scientific meeting and identify other variables that predisposed introducers or chairs to informal introduction. STUDY DESIGN: Observational study. SAMPLE POPULATION: Thirteen session chairs introducing 68 lectures (41 by females, 27 by males) by 63 speakers. METHODS: Observers recorded the session introducer, speaker, and whether speakers were introduced with a formal or informal title. Information evaluated included type of oral presentation; introducer gender, year, and country of graduation from veterinary school; speaker gender; whether the speaker was a resident; and speaker's year of graduation. RESULTS: Female speakers were introduced by their first name in 9 of 41 introductions compared to in 1 of 27 introductions for male speakers. This difference reached statistical significance when data independence was assumed (P = .043); however, this significance was narrowly lost when data clustering on session introducer was controlled for (P = .067). CONCLUSION: In this study, female speakers were more likely than male speakers to be introduced by their first and last names rather than with their professional title at a recent ACVS scientific meeting. IMPACT: Additional research is required to determine the effect of this type of subordinate language and gender bias in veterinary surgery.

A laparoscopic approach for removal of ovarian remnant tissue in 32 dogs.

BACKGROUND: Surgical treatment of ovarian remnant syndrome (ORS) in dogs usually necessitates large celiotomies and considerable manipulation of organs because of the relatively deep position of ovarian remnant tissue, large patient size, and often encountered adhesions. In women, laparoscopic treatment of ORS is successful and has significant advantages over laparotomy. Since laparoscopic ovariectomy has significant advantages over open ovariectomy in dogs, including reduced surgical stress and postoperative pain and shorter convalescence period, the rationale for a laparoscopic approach of canine ORS is evident. Feasibility and efficacy of a laparoscopic approach for treatment of ORS in dogs was prospectively evaluated using a standardized protocol for diagnosis, treatment, and follow-up. Treatment success was evaluated by histology of removed tissues, postoperative hormone testing, and long-term clinical follow-up. RESULTS: Thirty-two client-owned predominantly medium and large breed dogs diagnosed with ORS underwent abdominal ultrasound for ovarian remnant localization prior to laparoscopic surgery for removal of ovarian remnants. Tissue dissection and excision was performed using a vessel sealing forceps. Laparoscopy subjectively enabled detailed visibility and facilitated detection and removal of suspected ovarian tissue in all cases. Histology confirmed ovarian origin of removed tissue in all dogs. Additionally, a GnRH stimulation test was performed in fourteen dogs after a median follow-up of 10.5 months, which verified absence of residual functional ovarian remnant tissue in all dogs. Median surgery duration was 97.5 min and mean total convalescence duration, subjectively scored by owners, was 1.5 ± 0.7 days. No major complications occurred. Adhesions were observed in 79% of the dogs, complicated the surgical approach, and significantly affected surgery duration (85 versus 109 min; p = 0.03). Minor hemorrhage occurred in 12% and significantly increased surgery duration (95.5 versus 128 min; p = 0.02). Trendelenburg position and lateral tilting of the patient were essential for proper access to ovarian remnants. GnRH stimulation test results and/or absence of clinical signs indicative of ORS after a median follow-up period of 22.5 months confirmed treatment efficacy in all dogs. CONCLUSION: Laparoscopic surgery for ORS in dogs is effective with minimal complications and short convalescence and can successfully replace the conventional, more invasive open surgical procedure.

Effect of surgical site infection on survival after limb amputation in the curative-intent treatment of canine appendicular osteosarcoma: a Veterinary Society of Surgical Oncology retrospective study.

OBJECTIVE: To determine the influence of surgical site infection (SSI) on the median disease-free interval (DFI) and median survival time (MST) in dogs after amputation in the curative-intent treatment of appendicular osteosarcoma (OSA). STUDY DESIGN: Multi-institutional retrospective cohort study. ANIMALS: Fifteen dogs with OSA and SSI, and 134 dogs with OSA and no SSI. METHODS: Medical records were reviewed, and dogs were included if the following criteria were met: histologic confirmation of OSA, no evidence of metastasis, ≥1 chemotherapy treatment, and available follow-up data. We used the definition of SSI from the Centers for Disease Control and Prevention. Kaplan-Meier estimates of median DFI and MST for the SSI and non-SSI groups were compared by log-rank test. Univariate and multivariate Cox proportional hazard regression analysis was evaluated for associations with DFI and survival. RESULTS: The median DFI and MST of all OSA dogs were 236 days (95% CI, 181-283) and 283 days (95% CI 237-355), respectively. The median DFI of dogs with SSI (292 days) did not differ from that of dogs without SSI (224 days, P = .156). The MST of dogs with SSI (292 days) did not differ from that of dogs without SSI (280 days, P = .417). Failure to complete chemotherapy was associated with decreased DFI and survival (P < .001). Adjustments for chemotherapy completion found no effect of SSI on survival. CONCLUSION: SSI did not influence the survival of dogs with appendicular OSA treated with amputation and curative-intent treatment. CLINICAL SIGNIFICANCE: The extended survival associated with SSI after limb-spare surgery for OSA does not appear to be present after amputation. Interactions between the canine immune system and OSA warrant additional study.

Transplantation of Adipose Tissue-Derived Stem Cell Sheet to Reduce Leakage After Partial Colectomy in A Rat Model.

Anastomotic leakage is a disastrous complication after colorectal surgery. Although current methods for leakage prevention have different levels of clinical efficacy, they are until now imperfect solutions. Stem cell therapy using ASC sheets could provide a solution to this problem. ASCs are considered as promising candidates for promoting tissue healing because of their trophic and immunomodulatory properties. Here, we provide methods to produce high-density ASC sheets, that are transplanted onto a colorectal anastomosis in a rat model to reduce the leakage. ASCs formed cell sheets in thermo-responsive culture dishes that could be easily detached. On the day of the transplantation, a partial colectomy with a 5-suture colorectal anastomosis was performed. Animals were immediately transplanted with 1 ASC sheet per rat. ASC sheets adhered spontaneously to the anastomosis without any glue, suture, or any biomaterial. Animal groups were sacrificed 3 and 7 days postoperatively. Compared to transplanted animals, the incidence of anastomotic abscesses and leakage was higher in control animals. In our model, the transplantation of ASC sheets after colorectal anastomosis was successful and associated with a lower leakage rate.

Utility of contrast-enhanced computed tomography in the evaluation of canine insulinoma location.

OBJECTIVES: To determine 1) the sensitivity of contrast-enhanced CT (CECT) for detection of primary canine insulinomas and metastases 2) the sensitivity of CECT to locate canine insulinomas within the pancreas and 3) the CECT attenuation pattern of canine insulinomas and post-contrast phase in which insulinomas have the best visibility. METHODS: A retrospective review was performed of the medical records of 27 canine insulinoma patients. Simultaneous occurrence of blood glucose < 3.5 mmol/L (reference interval: 4.2-5.8 mmol/L) and plasma insulin > 10 mIU/L (reference interval: 1.4-24.5 mIU/L) were considered diagnostic for insulinoma. The dogs had a mean age of 9.0 ± 1.7 (SD) years and comprised 11 males and 17 females. RESULTS: Using CECT-scans, 26/27 insulinomas were successfully detected. However, CECT-scans predicted the correct location of insulinomas within the pancreas in only 14/27 dogs. In 9/13 inaccurately located insulinoma cases, the location error was major. There was no significant difference between triple, double and single-phase CECT-scans with location accuracies of 54%, 50% and 50%, respectively. Also, there was no specific post-contrast phase in which insulinomas could be visualised best. Detection of lymph node metastases with CECT-scans had a sensitivity of 67% (10/15 lymph node metastases). Detection of liver metastases had a sensitivity of 75% (6/8 liver metastases). This study highlights that major location errors mainly occurred if single- or double-phase CECT-scans were used (6/9 cases). CONCLUSION: It is suggested that triple-phase CECT-scans have superior outcome over single- or double-phase CECT-scans in pre-operative imaging of canine insulinomas.

Human Mesenchymal Stromal Cell Sheets Induce Macrophages Predominantly to an Anti-Inflammatory Phenotype.

Tissue healing is a highly complex process involving a cascade of biochemical and cellular events. Excessive inflammation can impair the healing response. Previous in vitro studies have shown that mesenchymal stromal cells can modulate macrophage-induced inflammation and, therefore, are promising candidates for cell-based therapies aimed at promoting tissue repair. Recently, cell sheets were introduced as a new method of delivering stromal cells to the repair site. The goal of the current study was to compare the effect of different types of stromal cell sheets on the inflammatory state of macrophages in vitro. We compared the effects of adipose tissue-derived stromal cell (ASC) sheets, bone marrow derived stromal cell (BMSC) sheets, and fibroblast sheets on macrophage functional phenotype using flow cytometric analysis, gene expression, as well as cell sheet protein secretion. This was evaluated with and without inflammatory stimulation. Viability and senescence for the different types of sheet were also evaluated. Macrophages cultured in ASC sheet conditioned medium (CM) displayed a higher fluorescence intensity of the anti-inflammatory CD206 surface marker than when cultured in BMSC sheet CM and expressed more CCL18 and IL1RA than when cultured in fibroblast sheet CM. Moreover, ASC sheets had higher cell viability and less senescent cells than BMSC sheets and fibroblast sheets. Taken together, ASC and BMSC can stimulate the anti-inflammatory macrophage (M2) phenotype to a better extent than fibroblasts. It is suggested that ASC sheets might outperform BMSC sheets in an inflammatory situation since ASC sheet CM induced-macrophages have more M2 characteristics, and ASC in the sheet was more viable.

C-reactive protein, glucose and iron concentrations are significantly altered in dogs undergoing open ovariohysterectomy or ovariectomy.

BACKGROUND: There are relatively few studies about the canine surgical stress response, a sequence of events orchestrated by the body in response to a surgical trauma which is sometimes, as shown in human surgery, deleterious to the patient. There is a need to identify objective markers to quantify this response in order to estimate tissue trauma and use the markers as potential early indicators of surgical complications. The study objective was to investigate the surgical stress response, measured by C-reactive protein (CRP), glucose and iron serum concentrations, to gonadectomy in female dogs, and to compare the response to ovariohysterectomy (OHE) with the response to ovariectomy (OVE). A randomized clinical trial was performed on a sample of 42 female dogs, which were divided into two groups: one group underwent OHE, the other OVE. RESULTS: Blood samples were collected immediately before surgery (T0), and at 1 (T1), 6 (T6), and 24 (T24) h after surgery, and serum frozen and stored at - 80 °C for later analysis. Upon thawing, the serum samples were subjected to measurement of CRP, glucose and iron concentration. Seventeen dogs in the OHE group and 19 dogs in the OVE group were included in the statistical analysis. There was a significant increase in glucose concentration at all time points compared with T0, and an increase of CRP at T6 and T24. Iron concentration was significantly decreased at T6 and T24. Differences between the two groups could not be detected for any of the three variables. CONCLUSIONS: The study showed that both OHE and OVE induce a moderate surgical stress response in female dogs, measured by CRP, glucose and iron. A difference between the surgical techniques could not be detected for any of the variables, and hence; with regards to the parameters studied recommendations of one procedure over the other cannot be made and preferred technique remains the surgeon's choice.

Adipose Tissue-Derived Stem Cell Sheet Application for Tissue Healing In Vivo: A Systematic Review.

Adipose tissue-derived stem cells (ASCs) are known to be tissue-healing promoters due to their cellular plasticity and secretion of paracrine factors. Cultured ASC sheets provide a novel method of ASC application and can retain ASCs at the targeted tissue. The purpose of this systematic review is to evaluate preclinical studies using ASC sheet transplantation therapy for promoting tissue healing. First, we searched databases to identify studies of ASC sheet therapy in different experimental animal models, and then determined the quality score of studies using SYRCLE's risk bias tool. A total of 18 included studies examined the role of ASC sheets on tissue healing and function in models for myocardial infarction, dilated cardiomyopathy, full-thickness skin wounds, hind limb ischemia, esophageal strictures, and oral ulcers. ASC sheet application after myocardial infarction improved survival rate, cardiac function, and capillary density and reduced the extent of fibrosis. Application of ASC sheets to a full-thickness skin wound decreased the wound size and stimulated wound maturation. In the hind limb ischemia model, ASC sheet application improved limb perfusion and capillary density, and decreased the amount of ischemic tissue and inflammation. ASC sheet application to mucosal wounds of the digestive tract accelerated wound healing and decreased the degree of stricture and fibrosis. Taken together, transplanted ASC sheets had a positive effect on tissue healing and reconstruction in these preclinical studies. The reported favorable effects of ASC sheet therapy in various tissue healing applications may be implemented in future translational studies. It is suggested that future preclinical animal model studies of ASC sheet therapy should concern standardization of culture techniques and investigate the mechanisms of action. In addition, clearly indicated experimental setups according to the SYRCLE's guidelines should improve study quality and validity.

Reference gene validation for gene expression normalization in canine osteosarcoma: a geNorm algorithm approach.

BACKGROUND: Quantitative PCR (qPCR) is a common method for quantifying mRNA expression. Given the heterogeneity present in tumor tissues, it is crucial to normalize target mRNA expression data using appropriate reference genes that are stably expressed under a variety of pathological and experimental conditions. No studies have validated specific reference genes in canine osteosarcoma (OS). Previous gene expression studies involving canine OS have used one or two reference genes to normalize gene expression. This study aimed to validate a panel of reference genes commonly used for normalization of canine OS gene expression data using the geNorm algorithm. qPCR analysis of nine canine reference genes was performed on 40 snap-frozen primary OS tumors and seven cell lines. RESULTS: Tumors with a variety of clinical and pathological characteristics were selected. Gene expression stability and the optimal number of reference genes for gene expression normalization were calculated. RPS5 and HNRNPH were highly stable among OS cell lines, while RPS5 and RPS19 were the best combination for primary tumors. Pairwise variation analysis recommended four and two reference genes for optimal normalization of the expression data of canine OS tumors and cell lines, respectively. CONCLUSIONS: Appropriate combinations of reference genes are recommended to normalize mRNA levels in canine OS tumors and cell lines to facilitate standardized and reliable quantification of target gene expression, which is essential for investigating key genes involved in canine OS metastasis and for comparative biomarker discovery.

Negative pressure therapy versus passive open abdominal drainage for the treatment of septic peritonitis in dogs: A randomized, prospective study.

OBJECTIVE: To compare passive open abdominal drainage (POAD) and negative-pressure abdominal drainage (NPAD) using the ABThera™ system in the treatment of septic peritonitis. STUDY DESIGN: Randomized prospective clinical trial. ANIMALS: Dogs (n = 16) with septic peritonitis. METHODS: Dogs with septic peritonitis were randomly assigned to one of two treatment protocols: NPAD versus POAD. Anesthesia time, operating time, duration of drainage, costs, survival, and complications were compared between techniques. Hematological and biochemical parameters in blood and abdominal fluid, and histopathological findings of omentum and abdominal wall tissue samples were compared between NPAD and POAD at time of initial surgery and at time of closure. RESULTS: Overall survival was 81%. Treatment costs, anesthesia and operating time, drainage time, survival, and postoperative complications were similar between techniques. Loss of total plasma protein and decreased inflammation-related factors in abdominal fluid at time of closure were noted in all patients. Neutrophilic inflammation was greater in abdominal wall samples after NPAD. POAD patients showed discomfort during bandage changes and had frequent leakage of abdominal fluid outside of the bandage. CONCLUSION: NPAD is an effective alternative to POAD for treatment of septic peritonitis, based on costs and survival. NPAD resulted in less abdominal fluid leakage, and evidence of superior healing on histological evaluation of abdominal tissues.

Effects of adipose stem cell sheets on colon anastomotic leakage in an experimental model: Proof of principle.

The most dreaded complication of colorectal surgery is anastomotic leakage. Adipose tissue-derived stem cell sheets (ASC sheets) prepared from temperature-responsive culture surfaces can be easily transplanted onto tissues. These sheets are proposed to improve cell transplant efficiency and enhance wound healing. The aim of this study was to investigate whether application of ASC sheets could prevent leakage of sutured colorectal anastomoses. Insufficient suturing of colorectal anastomoses was performed in Wistar rats to create a colorectal anastomotic leakage model. Rats were randomized to ASC sheet application or control group. Leakage, abscess formation, adhesion formation, anastomotic bursting pressure (ABP), and histology were evaluated on postoperative day 3 or 7. ASC sheet application significantly reduced anastomotic leakage compared to controls, without increased adhesion formation. ASC sheet transplantation resulted in more CD3+ T-cells and CD163+ anti-inflammatory macrophages at the anastomotic site than the control group. ABP, vessel density and collagen deposition were not different between groups. Using cell sheet technology, we generated ASC sheets that prevented disruption of sutured colorectal anastomoses as shown by reduced leakage. Increased numbers of anti-inflammatory macrophages and T-cells might have contributed to this positive effect.

Cordless ultrasonic dissector versus advanced bipolar vessel sealing device for laparoscopic ovariectomy in dogs.

OBJECTIVE: To compare Sonicision cordless ultrasonic dissector (SCUD) to LigaSure vessel sealing device (LVSD) for laparoscopic ovariectomy (Lap OVE) in dogs. STUDY DESIGN: Randomized, paired prospective clinical trial. ANIMALS: Client-owned dogs (n = 22) presented for elective Lap OVE. METHODS: Dogs were randomly assigned to one of two protocols: protocol 1 required the left ovary resected using SCUD and the right ovary using LVSD; protocol 2 required the left ovary resected using LVSD and the right ovary using SCUD. Duration of ovary excision, complications, surgical smoke production, and collateral thermal damage were compared between SCUD and LVSD. Total surgery duration, postoperative convalescence, obesity, mesovarial fat score, and technique-associated costs were also recorded. RESULTS: Ovary excision was significantly faster with LVSD than SCUD. Surgical smoke production was significantly greater for SCUD than LVSD. Minor pedicle hemorrhage occurred 3 times with SCUD and one time with LVSD (not significantly different) and was easily corrected intraoperative. Presence of hemorrhage significantly increased ovary excision time. Technique-associated costs were lower for SCUD than LVSD. No significant differences were found in collateral thermal damage between SCUD and LVSD. Total surgery duration and convalescence time were similar to previous reports of Lap OVE in dogs at the authors' institution. CONCLUSIONS: SCUD is a cost-effective alternative for Lap OVE, taking into account differences in technique and user preference.

Effect of Cell Seeding Density and Inflammatory Cytokines on Adipose Tissue-Derived Stem Cells: an in Vitro Study.

Adipose tissue-derived stem cells (ASCs) are known to be able to promote repair of injured tissue via paracrine factors. However, the effect of cell density and inflammatory cytokines on the paracrine ability of ASCs remains largely unknown. To investigate these effects, ASCs were cultured in 8000 cells/cm2, 20,000 cells/cm2, 50,000 cells/cm2, and 400,000 cells/cm2 with and without 10 or 20 ng/ml tumor necrosis factor alpha (TNFα) and 25 or 50 ng/ml interferon gamma (IFNγ). ASC-sheets formed at 400,000 cells/cm2 after 48 h of culture. With increasing concentrations of TNFα and IFNγ, ASC-sheets with 400,000 cells/cm2 had increased production of angiogenic factors Vascular Endothelial Growth Factor and Fibroblast Growth Factor and decreased expression of pro-inflammatory genes TNFA and Prostaglandin Synthase 2 (PTGS2) compared to lower density ASCs. Moreover, the conditioned medium of ASC-sheets with 400,000 cells/cm2 stimulated with the low concentration of TNFα and IFNγ enhanced endothelial cell proliferation and fibroblast migration. These results suggest that a high cell density enhances ASC paracrine function might beneficial for wound repair, especially in pro-inflammatory conditions.

Identification of CD90 as Putative Cancer Stem Cell Marker and Therapeutic Target in Insulinomas.

The long-term prognosis after surgical resection of malignant insulinoma (INS) is poor. Novel adjuvant therapies, specifically targeting cancer stem cells (CSCs), are warranted. Therefore, the goal of this study was to characterize and target putative INS CSCs. Using fluorescence-activated cell sorting, human INS cell line CM and pancreatic carcinoid cell line BON1 were screened for the presence of stem cell-associated markers. CD90, CD166, and GD2 were identified as potential CSC markers. Only CD90(+) INS cells had an increased tumor-initiating potential in athymic nude mice. Anti-CD90 monoclonal antibodies decreased the viability and metastatic potential of injected cells in a zebrafish embryo INS xenograft model. Primary INS stained positive for CD90 by immunohistochemistry, however also intratumoral fibroblasts and vascular endothelium showed positive staining. The results of this study suggest that anti-CD90 monoclonals form a potential novel adjuvant therapeutic modality by targeting either INS cells directly, or by targeting the INS microenvironment.

Identification of anti-proliferative kinase inhibitors as potential therapeutic agents to treat canine osteosarcoma.

Osteosarcoma is the most common primary bone tumour in dogs but various forms of therapy have not significantly improved clinical outcomes. As dysregulation of kinase activity is often present in tumours, kinases represent attractive molecular targets for cancer therapy. The purpose of this study was to identify novel compounds targeting kinases with the potential to induce cell death in a panel of canine osteosarcoma cell lines. The ability of 80 well-characterized kinase inhibitor compounds to inhibit the proliferation of four canine osteosarcoma cell lines was investigated in vitro. For those compounds with activity, the mechanism of action and capability to potentiate the activity of doxorubicin was further evaluated. The screening showed 22 different kinase inhibitors that induced significant anti-proliferative effects across the four canine osteosarcoma cell lines investigated. Four of these compounds (RO 31-8220, 5-iodotubercidin, BAY 11-7082 and an erbstatin analog) showed significant cell growth inhibitory effects across all cell lines in association with variable induction of apoptosis. RO 31-8220 and 5-iodotubercidin showed the highest ability to potentiate the effects of doxorubicin on cell viability. In conclusion, the present study identified several potent kinase inhibitors targeting the PKC, CK1, PKA, ErbB2, mTOR and NF-κB pathways, which may warrant further investigations for the treatment of osteosarcoma in dogs.

Evaluation of prognostic indicators using validated canine insulinoma tissue microarrays.

Tissue microarray (TMA) technology allows analysis of multiple tumour samples simultaneously on a single slide. The aim of the present study was to develop and assess a TMA containing 32 primary canine insulinomas and 13 insulinoma metastases. The results of histopathological and immunohistochemical analyses of triplicate core biopsies were compared with those of individual tissue sections using weighted κ statistics. Inter-observer agreement of TMA immunohistochemistry scores were assessed for chromogranin A (CgA), insulin, growth hormone (GH), growth hormone receptor (GHR) and Ki67 index, as well as the prognostic utility of clinicopathological, histopathological and immunohistochemical criteria. There was substantial agreement of scores for histopathological parameters (κ = 0.64-0.70) and a substantial to near-perfect agreement for homogenous immunohistochemical parameters (κ = 0.69-1.00). Except for GH, which demonstrated heterogeneous staining, there was good to excellent inter-observer agreement for all other immunohistochemical staining scores (intra-class correlation coefficients: 0.70-1.00). On univariate analysis, the presence of nuclear atypia was significantly predictive of disease-free intervals (DFIs) for canine insulinoma, while tumour size, TNM stage, necrosis and Ki67 index were significant in terms of prognosis, with respect to both DFI and survival time. On multivariate analysis, tumour size and Ki67 index retained predictive power for survival time, as did tumour size for DFI. This study confirms the applicability of TMA technology for evaluation of canine insulinoma.