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Gerry Polton - One of the best experts on this subject based on the ideXlab platform.
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outcome in dogs with advanced stage 3b Anal Sac gland carcinoma treated with surgery or hypofractionated radiation therapy
Veterinary and Comparative Oncology, 2017Co-Authors: Valeria Meier, Gerry Polton, Malgorzata Roos, S Cancedda, P Laganga, T Emmerson, Rohrer C BleyAbstract:Stage 3b Anal Sac gland carcinoma (ASGC) can be life-threatening. A surgical approach is not always possible or may be declined. Dogs with stage 3b ASGC treated with surgery or conformal radiation therapy (RT) with 8 × 3.8 Gy (total dose 30.4 Gy, over 2.5 weeks) were retrospectively evaluated. Patient characteristics, median progression-free interval (PFI) and median survival time (MST) were compared. Twenty-eight dogs were included; 15 underwent surgery, 13 underwent RT. At the time of presentation, 21% showed life-threatening obstipation and 25% showed hypercalcaemia. PFI and MST for surgery cases were 159 days (95% CI: 135-184 days) and 182 days (95% CI: 146-218 days), both significantly lower than for RT cases with 347 days (95% CI: 240-454 days) and 447 days (95% CI: 222-672 days), (P = 0.01, P = 0.019). Surgery as well as RT led to a fast relief of symptoms. PFI and survival of surgical patients were significantly inferior to that of a comparable patient group treated with conformal hypofractionated RT.
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Anal Sac gland carcinoma in cocker spaniels
Veterinary Record, 2008Co-Authors: Gerry PoltonAbstract:SIR, — English cocker spaniels, and to a lesser extent springer and cavalier King Charles spaniels, are at higher risk of developing Anal Sac gland tumours than other dogs. This conclusion is based upon the Analysis of large numbers of cases of Anal Sac gland carcinomas using data from veterinary
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expression of e cadherin in canine Anal Sac gland carcinoma and its association with survival
Veterinary and Comparative Oncology, 2007Co-Authors: Gerry Polton, L M Green, M J Brearley, Timothy J ScaseAbstract:The objective of this study was to determine whether an association could be demonstrated between survival and the expression of the adhesion molecule E-cadherin by the neoplastic cells in a group of dogs with Anal Sac gland carcinomas (ASGCs). Archived formalin-fixed, paraffin wax-embedded primary tumour specimens were obtained for 36 cases of canine ASGC with known clinical management and survival data. Immunohistochemical methods were used to evaluate E-cadherin expression by the neoplastic cells and data were evaluated for an association between E-cadherin expression and survival. On univariate Analysis, the median survival time for cases with tumours expressing E-cadherin in more than 75% of cells was significantly greater than that for cases with tumours expressing E-cadherin in fewer than 75% of cells (1168 versus 448 days, P = 0.0246). Both E-cadherin expression and presence or absence of distant metastases were significantly associated with survival on multivariate Analysis. This study demonstrates that expression of E-cadherin at the cytoplasmic membrane in canine ASGCs is variable and potentially predictive of survival.
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clinical stage therapy and prognosis in canine Anal Sac gland carcinoma
Journal of Veterinary Internal Medicine, 2007Co-Authors: Gerry Polton, M J BrearleyAbstract:Background:Reports of canine Anal Sac gland carcinoma (ASGC) describe varied clinical presentations and management and differing responses to therapy. A unifying approach to clinical stage determination and management of this disease has yet to be presented. Hypothesis:An ordinal clinical staging scheme for canine ASGC can be devised on the basis of responses to therapy for a retrospective cohort of affected dogs. Animals:130 dogs with naturally occurring ASGC. Methods:A simplified clinical stage system and a management algorithm for canine ASGC were derived from retrospective evaluation of a cohort of 80 dogs; applicability of both was then prospectively evaluated in a cohort of 50 dogs. Results:Retrospective evaluation revealed 4 statistically significant negative prognostic indicators for survival: lack of therapy, presence of distant metastases, presence of lymph node metastases, and primary tumor size. Lymph node extirpation was a statistically significant positive prognostic indicator by bivariate Analysis. In both retrospective and prospective Analyses, the modified clinical stage scheme revealed a significant association with survival time. Conclusions and Clinical Importance: The clinical staging scheme permits differentiation between groups in terms of prognosis and, therefore, decisions on therapy. This will facilitate application of appropriate therapy and enhanced communication and collaboration in further investigations of ASGC.
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breed gender and neutering status of british dogs with Anal Sac gland carcinoma
Veterinary and Comparative Oncology, 2006Co-Authors: Gerry Polton, V Mowat, H C Lee, K A Mckee, Timothy J ScaseAbstract:This study details the breed, gender and neutering status of a large cohort of British canine patients suffering from histologically confirmed Anal Sac gland carcinoma. Estimates of the relative risk for the development of this disease attributable to these factors are calculated. To reduce the impact of sampling errors, cases were selected from veterinary histopathology laboratories rather than referral hospital databases, and multiple estimates of the general British canine population were used. The weaknesses of the statistical assumptions made are discussed. There was no evidence to support a gender predisposition for the development of this condition. English cocker spaniels are significantly over-represented, with a mean relative risk estimate of 7.3. The mean relative risk estimate associated with being neutered was 1.4; the effect of neutering appeared to be more significant in male dogs compared with that in female dogs.
Timothy J Scase - One of the best experts on this subject based on the ideXlab platform.
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expression of e cadherin in canine Anal Sac gland carcinoma and its association with survival
Veterinary and Comparative Oncology, 2007Co-Authors: Gerry Polton, L M Green, M J Brearley, Timothy J ScaseAbstract:The objective of this study was to determine whether an association could be demonstrated between survival and the expression of the adhesion molecule E-cadherin by the neoplastic cells in a group of dogs with Anal Sac gland carcinomas (ASGCs). Archived formalin-fixed, paraffin wax-embedded primary tumour specimens were obtained for 36 cases of canine ASGC with known clinical management and survival data. Immunohistochemical methods were used to evaluate E-cadherin expression by the neoplastic cells and data were evaluated for an association between E-cadherin expression and survival. On univariate Analysis, the median survival time for cases with tumours expressing E-cadherin in more than 75% of cells was significantly greater than that for cases with tumours expressing E-cadherin in fewer than 75% of cells (1168 versus 448 days, P = 0.0246). Both E-cadherin expression and presence or absence of distant metastases were significantly associated with survival on multivariate Analysis. This study demonstrates that expression of E-cadherin at the cytoplasmic membrane in canine ASGCs is variable and potentially predictive of survival.
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breed gender and neutering status of british dogs with Anal Sac gland carcinoma
Veterinary and Comparative Oncology, 2006Co-Authors: Gerry Polton, V Mowat, H C Lee, K A Mckee, Timothy J ScaseAbstract:This study details the breed, gender and neutering status of a large cohort of British canine patients suffering from histologically confirmed Anal Sac gland carcinoma. Estimates of the relative risk for the development of this disease attributable to these factors are calculated. To reduce the impact of sampling errors, cases were selected from veterinary histopathology laboratories rather than referral hospital databases, and multiple estimates of the general British canine population were used. The weaknesses of the statistical assumptions made are discussed. There was no evidence to support a gender predisposition for the development of this condition. English cocker spaniels are significantly over-represented, with a mean relative risk estimate of 7.3. The mean relative risk estimate associated with being neutered was 1.4; the effect of neutering appeared to be more significant in male dogs compared with that in female dogs.
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expression of e cadherin in canine Anal Sac apocrine gland adenocarcinoma and its association with survival
Veterinary and Comparative Oncology, 2005Co-Authors: Gerry Polton, Vicki J Adams, L M Green, M J Brearley, Timothy J ScaseAbstract:Introduction: Inverse associations have been shown between E-cadherin expression and degree of differentiation in canine mammary tumours and with the acquisition of malignancy in human epithelial cancers. The purpose of this study was to examine whether there was an association between prognosis, and the distribution or intensity of immunohistochemical staining for E-cadherin in Anal Sac adenocarcinoma. Methods: Formalin-fixed paraffin-wax embedded canine Anal Sac adenocarcinoma specimens were obtained for 36 patients for whom clinical data, including survival statistics, were available. Canine mammary adenoma tissue was employed as the positive and negative controls with antibody diluent replacing the primary antibody in the latter. Samples were scored according to proportion of cells showing positive cytoplasmic membranous staining, intensity of cytoplasmic membranous staining and proportion of nuclei staining. As quality control, a sample of 10 slides was randomly selected for repeat evaluation; results exactly matched those obtained in the first assessment. Results: All Anal Sac adenocarcinoma cells expressed E-cadherin to varying degrees. There was no evidence of an association between survival time and the intensity of staining or the proportion of nuclei staining. Patients whose tumours exhibited >75% positive cytoplasmic membranous staining survived significantly longer than those exhibiting <75% staining with median survival times of 1100 and 479 days respectively (log rank test: χ2 = 3.89, 1 DF, p = 0.049). Conclusion: Immunohistochemical evaluation of the proportion of cells in Anal Sac adenocarcinoma samples exhibiting positive cytoplasmic membranous staining for E-cadherin may allow improved determination of prognoses and could aid clinical decision making.
David A Coil - One of the best experts on this subject based on the ideXlab platform.
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bacteria isolated from bengal cat felis catus prionailurus bengalensis Anal Sac secretions produce volatile compounds potentially associated with animal signaling
PLOS ONE, 2019Co-Authors: Mei S Yamaguchi, Holly H Ganz, Adrienne W Cho, Thant H Zaw, Guillaume Jospin, Mitchell M Mccartney, Cristina E Davis, Jonathan A Eisen, David A CoilAbstract:In social animals, scent secretions and marking behaviors play critical roles in communication, including intraspecific signals, such as identifying individuals and group membership, as well as interspecific signaling. Anal Sacs are an important odor producing organ found across the carnivorans (species in the mammalian Order Carnivora). Secretions from the Anal Sac may be used as chemical signals by animals for behaviors ranging from defense to species recognition to signaling reproductive status. In addition, a recent study suggests that domestic cats utilize short-chain free fatty acids in Anal Sac secretions for individual recognition. The fermentation hypothesis is the idea that symbiotic microorganisms living in association with animals contribute to odor profiles used in chemical communication and that variation in these chemical signals reflects variation in the microbial community. Here we examine the fermentation hypothesis by characterizing volatile organic compounds (VOC) and bacteria isolated from Anal Sac secretions collected from a male Bengal cat (Felis catus × Prionailurus bengalensis), a cross between the domestic cat and the leopard cat. Both left and right Anal Sacs of a male Bengal cat were manually expressed (emptied) and collected. Half of the material was used to culture bacteria or to extract bacterial DNA and the other half was used for VOC Analysis. DNA was extracted from the Anal Sac secretions and used for a 16S rRNA gene PCR amplification and sequencing based characterization of the microbial community. Additionally, some of the material was plated out in order to isolate bacterial colonies. Three taxa (Bacteroides fragilis, Tessaracoccus, and Finegoldia magna) were relatively abundant in the 16S rRNA gene sequence data and also isolated by culturing. Using Solid Phase Microextraction (SPME) gas chromatography-mass spectrometry (GC-MS), we tentatively identified 52 compounds from the Bengal cat Anal Sac secretions and 67 compounds from cultures of the three bacterial isolates chosen for further Analysis. Among 67 compounds tentatively identified from bacterial isolates, 51 were also found in the Anal Sac secretion. We show that the bacterial community in the Anal Sac consists primarily of only a few abundant taxa and that isolates of these taxa produce numerous volatiles that are found in the combined Anal Sac volatile profile. Several of these volatiles are found in Anal Sac secretions from other carnivorans, and are also associated with known bacterial biosynthesis pathways. This is consistent with the fermentation hypothesis and the possibility that the Anal Sac is maintained at least in part to house bacteria that produce volatiles for the host.
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bacteria isolated from bengal cat felis catus prionailurus bengalensis Anal Sac secretions produce volatile compounds associated with animal signaling
bioRxiv, 2019Co-Authors: Mei S Yamaguchi, Holly H Ganz, Adrienne W Cho, Thant H Zaw, Guillaume Jospin, Mitchell M Mccartney, Cristina E Davis, Jonathan A Eisen, David A CoilAbstract:Abstract Anal Sacs are an important odor producing organ found across the mammalian Order Carnivora. Secretions from the Anal Sac may be used as chemical signals by animals for behaviors ranging from defense to species recognition to signaling reproductive status. In addition, a recent study suggests that domestic cats utilize short-chain free fatty acids in Anal Sac secretions for individual recognition. The fermentation hypothesis is the idea that symbiotic microorganisms living in association with animals contribute to odor profiles used in chemical communication and that variation in these chemical signals reflects variation in the microbial community. Here we examine the fermentation hypothesis by characterizing volatile organic compounds (VOC) and bacteria isolated from Anal Sac secretions collected from a male bengal cat, a cross between a domestic cat and wild leopard cat (Felis catus × Prionailurus bengalensis). Both left and right Anal Sacs of a male bengal cat were manually expressed (emptied) and collected. Half of the material was used to culture bacteria or to extract bacterial DNA and other half was used for VOC Analysis. DNA was extracted from the Anal Sac secretions and used for a 16S rRNA gene sequence based characterization of the microbial community. Additionally, some of the material was plated out in order to isolate bacterial colonies. The same three taxa, Bacteroides fragilis, Tessaracoccus, and Finegoldia magna were abundant in the 16S rRNA gene sequence data and also isolated by culturing. Using Solid Phase Microextraction (SPME) gas chromatography-mass spectrometry (GC-MS), we tentatively identified 52 compounds from bengal cat Anal Sac secretions and 67 compounds from cultures of the three bacterial isolates chosen for further Analysis.. Among 67 compounds tentatively identified from bacteria isolates, 52 were also found in the Anal Sac secretion. We show that the bacterial community in the Anal Sac consists primarily of only a few abundant taxa and that isolates of these taxa produce numerous volatiles that are found in the combined Anal Sac volatile profile. Many of these volatiles are found in Anal Sac secretions from other carnivorans, and are also associated with known bacterial biosynthesis pathways. This supports the fermentation hypothesis and the idea that the Anal Sac is maintained at least in part to house bacteria that produce volatiles for the host.
Amy K. Leblanc - One of the best experts on this subject based on the ideXlab platform.
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Expression of PDGFR-β and Kit in canine Anal Sac apocrine gland adenocarcinoma using tissue immunohistochemistry
Veterinary and comparative oncology, 2011Co-Authors: R. J. Brown, Shelley J. Newman, D. C. Durtschi, Amy K. LeblancAbstract:Canine Anal Sac apocrine gland adenocarcinoma (ASAGAC) is an uncommon but highly invasive and metastatic malignancy. Toceranib phosphate (Palladia) is a receptor tyrosine kinase (RTK) inhibitor that targets several members of the split kinase RTK family. These membrane receptors are important for cell cycling, apoptosis and angiogenesis, all of which can contribute to carcinogenesis. The objective of this study was to evaluate archived, paraffin-embedded canine ASAGAC and normal canine Anal Sacs for immunohistochemical detection of Kit and platelet-derived growth factor receptor beta (PDGFR-β). Two of 77 neoplasms (2.6%) expressed Kit. Fifteen of the neoplasms (19.5%) were positive for PDGFR-β expression. None of the normal canine Anal Sac epithelium expressed Kit or PDGFR-β. Because of these results, further investigation should be considered to determine the role of RTKs in the clinical course and treatment of canine ASAGAC.
M J Brearley - One of the best experts on this subject based on the ideXlab platform.
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expression of e cadherin in canine Anal Sac gland carcinoma and its association with survival
Veterinary and Comparative Oncology, 2007Co-Authors: Gerry Polton, L M Green, M J Brearley, Timothy J ScaseAbstract:The objective of this study was to determine whether an association could be demonstrated between survival and the expression of the adhesion molecule E-cadherin by the neoplastic cells in a group of dogs with Anal Sac gland carcinomas (ASGCs). Archived formalin-fixed, paraffin wax-embedded primary tumour specimens were obtained for 36 cases of canine ASGC with known clinical management and survival data. Immunohistochemical methods were used to evaluate E-cadherin expression by the neoplastic cells and data were evaluated for an association between E-cadherin expression and survival. On univariate Analysis, the median survival time for cases with tumours expressing E-cadherin in more than 75% of cells was significantly greater than that for cases with tumours expressing E-cadherin in fewer than 75% of cells (1168 versus 448 days, P = 0.0246). Both E-cadherin expression and presence or absence of distant metastases were significantly associated with survival on multivariate Analysis. This study demonstrates that expression of E-cadherin at the cytoplasmic membrane in canine ASGCs is variable and potentially predictive of survival.
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clinical stage therapy and prognosis in canine Anal Sac gland carcinoma
Journal of Veterinary Internal Medicine, 2007Co-Authors: Gerry Polton, M J BrearleyAbstract:Background:Reports of canine Anal Sac gland carcinoma (ASGC) describe varied clinical presentations and management and differing responses to therapy. A unifying approach to clinical stage determination and management of this disease has yet to be presented. Hypothesis:An ordinal clinical staging scheme for canine ASGC can be devised on the basis of responses to therapy for a retrospective cohort of affected dogs. Animals:130 dogs with naturally occurring ASGC. Methods:A simplified clinical stage system and a management algorithm for canine ASGC were derived from retrospective evaluation of a cohort of 80 dogs; applicability of both was then prospectively evaluated in a cohort of 50 dogs. Results:Retrospective evaluation revealed 4 statistically significant negative prognostic indicators for survival: lack of therapy, presence of distant metastases, presence of lymph node metastases, and primary tumor size. Lymph node extirpation was a statistically significant positive prognostic indicator by bivariate Analysis. In both retrospective and prospective Analyses, the modified clinical stage scheme revealed a significant association with survival time. Conclusions and Clinical Importance: The clinical staging scheme permits differentiation between groups in terms of prognosis and, therefore, decisions on therapy. This will facilitate application of appropriate therapy and enhanced communication and collaboration in further investigations of ASGC.
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expression of e cadherin in canine Anal Sac apocrine gland adenocarcinoma and its association with survival
Veterinary and Comparative Oncology, 2005Co-Authors: Gerry Polton, Vicki J Adams, L M Green, M J Brearley, Timothy J ScaseAbstract:Introduction: Inverse associations have been shown between E-cadherin expression and degree of differentiation in canine mammary tumours and with the acquisition of malignancy in human epithelial cancers. The purpose of this study was to examine whether there was an association between prognosis, and the distribution or intensity of immunohistochemical staining for E-cadherin in Anal Sac adenocarcinoma. Methods: Formalin-fixed paraffin-wax embedded canine Anal Sac adenocarcinoma specimens were obtained for 36 patients for whom clinical data, including survival statistics, were available. Canine mammary adenoma tissue was employed as the positive and negative controls with antibody diluent replacing the primary antibody in the latter. Samples were scored according to proportion of cells showing positive cytoplasmic membranous staining, intensity of cytoplasmic membranous staining and proportion of nuclei staining. As quality control, a sample of 10 slides was randomly selected for repeat evaluation; results exactly matched those obtained in the first assessment. Results: All Anal Sac adenocarcinoma cells expressed E-cadherin to varying degrees. There was no evidence of an association between survival time and the intensity of staining or the proportion of nuclei staining. Patients whose tumours exhibited >75% positive cytoplasmic membranous staining survived significantly longer than those exhibiting <75% staining with median survival times of 1100 and 479 days respectively (log rank test: χ2 = 3.89, 1 DF, p = 0.049). Conclusion: Immunohistochemical evaluation of the proportion of cells in Anal Sac adenocarcinoma samples exhibiting positive cytoplasmic membranous staining for E-cadherin may allow improved determination of prognoses and could aid clinical decision making.