Lorenzo Ressel

The aim of this study was to investigate the role of thyroid transcription factor-1 (TTF-1) in the diagnosis of feline lung digit syndrome (FLDS) and to investigate the associations between the morphological features of FLDS and TTF-1 expression. We also compared the reliability of TTF-1 and transmission electron microscopy (TEM) in establishing the diagnosis of FLDS. Histology records of feline digit tumours were retrieved, including patients from 2008-2015. If formalin-fixed, paraffin-embedded tissues were available for review, patients were included in the study. As a control group we included 12 feline primary tumours of the digits. All the histological slides of the study group were blindly reviewed by the same veterinary pathologist. Representative sections of the lesions were selected for immunohistochemistry (IHC) analysis. To confirm the respiratory origin of the neoplastic tissue, TEM was used as a gold standard in all cases. Five cases of FLDS were included. TTF-1 was wea...

Fifty-four canine mammary lesions (15 hyperplasias, 7 adenomas and 32 carcinomas) were submitted to immunohistochemical analysis for the evaluation of PTEN and E-cadherin co-expression. Subjects bearing mammary carcinomas were also submitted to a 2-year follow-up study to compare immunohistochemical results with overall survival. All the hyperplastic samples stained positive for both markers, 100% of adenomas were positive for PTEN and 86% for E-cadherin, and 69% and 34% of carcinomas were positive for PTEN and E-cadherin, respectively. Statistical analysis showed a positive correlation between these two proteins both considering all (p b 0.01) or malignant tumors (p < 0.05). The female dogs bearing tumors positively-stained for both markers had a longer overall survival (p < 0.05) and absence of lymphatics invasion (p < 0.05). Simultaneous double immunofluorescence confirmed the co-localization of the two proteins in neoplastic cells. Results reported in this study confirm the tumor suppressor effect of these two molecules.

The transcription factor Nrf2 exerts protective effects in numerous experimental models of acute kidney injury, and is a promising therapeutic target in chronic kidney disease. To provide a detailed insight into the regulatory roles of Nrf2 in the kidney, we performed integrated transcriptomic and proteomic analyses of kidney tissue from wild-type and Nrf2 knockout mice treated with the Nrf2 inducer methyl-2-cyano-3,12-dioxooleano-1,9-dien-28-oate (CDDO-Me, also known as bardoxolone methyl). After 24 h, analyses identified 2561 transcripts and 240 proteins that were differentially expressed in the kidneys of Nrf2 knockout mice, compared with those of wild-type counterparts, and 3122 transcripts and 68 proteins that were differentially expressed in wild-type mice treated with CDDO-Me, compared with those of vehicle control. In the light of their sensitivity to genetic and pharmacological modulation of renal Nrf2 activity, genes/proteins that regulate xenobiotic disposition, redox bal...

A 7-month-old male cross breed dog was presented with hyperextensible skin and atrophic scarring. A diagnosis of Ehlers-Danlos syndrome was made based on clinical signs, histopathology and electron microscopy. Two weeks after presentation, the dog died suddenly. Post-mortem examination revealed haemothorax and rupture of the left subclavian artery. Histological findings, including Goldner's modified Masson's trichrome staining and transmission electron microscopy of the subclavian artery, revealed abnormalities in the structure and arrangement of collagen fibrils, suggesting that the defective collagen formation extended to the vasculature. To the authors' knowledge, this is the first report of Ehlers-Danlos syndrome with vascular involvement in animals.

Information about histiocytic disease in cats is limited. The aim of this study was to document clinical findings and outcome in feline histiocytic disorders, and characterize the expression of PDGFRβ and KIT in order to identify potential treatment targets. Morphologically diagnosed feline histiocytic tumours were reviewed and characterized by immunohistochemistry (IHC). Five cases of feline progressive histiocytosis (FPH), eight histiocytic sarcomas (HS) and two haemophagocytic histiocytic sarcomas (HaeHS) were confirmed. PDGFRβ was variably positive in most histiocytic cases, while KIT was negative in all. Clinical presentation, treatment and outcome were also evaluated. Partial responses were recorded in measurable disease with tyrosine kinase inhibitors and lomustine, and radiotherapy achieved long-term control in some cases. Survival times were shortest in HaeHS and disseminated disease. PDGFRβ, but not KIT, may represent a therapeutic target in feline histiocytic disorders but more studies are needed to investigate other potential treatment targets.

Insulin-like growth factor type II (IGF-II) is the main cause of non-islet cell tumour hypoglycaemia (NICTH) and insulin is thought to be the only factor causing hypoglycaemia in insulinomas. However, two case reports of pancreatic neuroendocrine tumours (PNETs) producing IGF-II have been previously published: a human and a canine patient. In this study, we investigated clinical, histopathological, immunohistochemical and ultrastructural features, and biological behaviour of canine pancreatic IGF-II-omas, a subgroup of PNETs that has not been previously characterized. Case records of 58 dogs with confirmed PNETs and hypoglycaemia were reviewed: six patients were affected by IGF-II-omas. Surgery was performed in all cases and two dogs had metastases. Four patients remained alive and in remission at 370, 440, 560 and 890 days post-diagnosis; two died of non-tumour-related causes. IGF-II-omas can be differentiated from insulinomas through hypoinsulinaemia, IGF-II positive and insulin negative immunostaining. The prevalence of this neoplasia is low, accounting for just 6% of PNETs.

The aim of this retrospective study was to describe clinical features, treatment and outcome of 21 dogs with metastatic cancer of unknown primary (MCUP), a biopsy-proven malignancy being diagnosed at a metastatic stage, in which the anatomical origin of the primary tumour cannot be detected. All dogs underwent total-body computed tomography. Signalment, type and duration of clinical signs, metastasis site, pathology results, treatment and outcome were recorded. Carcinoma was the most common diagnosis (57.1%), followed by sarcoma, melanoma and mast cell tumour. The median number of disease sites per dog was 2, with bones, lymph nodes, lungs and spleen being the most frequent metastatic locations. The median survival for all dogs was 30 days. Overall, a primary site was not identified in 20 (95.2%) dogs. MCUP encompasses a variety of different pathologic entities and harbours a poor prognosis.

We recently demonstrated that injection of conditioned medium (CM) generated from cells of the mesenchymal region of human amniotic membrane (AMTCs) reduces bleomycin-induced lung fibrosis in mice, suggesting a crucial role of paracrine factor(s) secreted by AMTCs in these beneficial effects. We further investigated this hypothesis, the mechanisms involved, the effects on some lung functional parameters and whether AMTC-secreted effector(s) are specific to these cells and not produced by other cell types, extending the time of analysis up to 28 days after treatment. Bleomycin-challenged mice were either treated with AMTC-CM or CM generated from human skin fibroblasts, human peripheral blood mononuclear cells or Jurkat cells, or were left untreated. Mouse lungs were analyzed for content of pro-inflammatory and pro-fibrotic molecules, presence of lymphocytes and macrophages and for fibrosis level (through histological semi-quantitative evaluation and quantitative measurement of collagen content). Arterial blood gas analysis was also performed. Up to 28 days after delivery, AMTC-CM-treated mice developed reduced lung fibrosis with respect to mice treated with other CM types. AMTC-CM-treated mice had comparatively better preservation of blood gas parameters and showed lower lung content of interleukin-6, tumor necrosis factor-α, macrophage inflammatory protein-1α, monocyte chemoattractant protein-1 and transforming growth factor-β associated with reduced lung macrophage levels. AMTC-CM prevents lung fibrosis in bleomycin-challenged mice, improving survival and preserving lung functional parameters such as blood gas exchanges. The specificity of AMTC-CM action was indicated by the absence of fibrosis reduction when other CM types were used. Finally, we provide some insights into the possible mechanisms underlying AMTC-CM-mediated control of fibrosis.

Muscular metastatic neoplasia has been reported to be rare in domestic animals, however previous studies were based primarily on necropsy findings. The purpose of this retrospective study was to describe whole body computed tomography (CT) characteristics of confirmed muscular metastases in a cohort of dogs and cats presented for oncology evaluation. Medical records of 1201 oncology patients were reviewed. Included animals underwent pre and postcontrast whole body CT, and CT-guided tru-cut biopsy or fine needle aspiration of one or more metastatic lesions. Twenty-one dogs and six cats met inclusion criteria, representing 2.08% of all canine oncology patients and 3.1% of all feline oncology patients. Mean age was 9.6 years. Postcontrast CT characteristics included well-demarcated, oval-to-round lesions with varying enhancement patterns: ring enhancing (n = 16), heterogeneously enhancing (n = 8), or homogeneously enhancing (n = 5). Five animals showed concurrent and varying nodular patterns. In seven cases (five dogs and two cats), one single muscular nodule was observed. In 20 cases, two or more lesions were observed. In two cases, cardiac hypodense nodules were observed in the postcontrast CT, while appearing isodense in the precontrast study. Necropsy confirmed neoplasia in both of them. Locations of muscular metastases included epaxial/paraspinal muscles of the cervical, thoracic, and lumbar spine (n = 18), superficial muscles of the thoracic wall (n = 13), scapular/shoulder region (n = 3), hind limb (n = 3), and abdominal wall muscles (n = 1). Findings supported the use of pre and postcontrast whole body CT for oncologic staging in dogs and cats, especially for primary tumors characterized by a high metastatic rate.

Leptin and its receptor (ObR) expression were investigated by immunohistochemistry in normal, hyperplastic and neoplastic canine mammary tissues and related to clinical-pathological features. Leptin expression was detected in healthy mammary tissues, adenosis and in benign mammary tumours and was lower in ductal hyperplasias and malignant tumours. A high percentage of ObR-positive cells were present in adenosis, benign tumours and in complex carcinomas, while ObR expression was lower in healthy mammary tissues, in ductal hyperplasias and in a large part of invasive mammary carcinomas. Our data demonstrated that cancer cells expressed at low level leptin and ObR in canine mammary tumours with a more aggressive behaviour, as well as in lymph node metastases. Consequently, leptin and ObR expressions in this species resulted to be not associated with a reduced overall survival.

Invasive lobular carcinoma (ILC) represents 15% of invasive human breast tumours. This report describes the morphological and immunohistochemical features of three canine mammary tumours comparable with human ILC. These tumours were composed of a non-delimited proliferation of discrete cells infiltrating fibrous connective tissue. Multifocal in-situ carcinoma associated with invasive lesions was present. Invasive tumour cells and in-situ lesions expressed cytokeratin and CK34betaE12, but not E-cadherin. Based on these morphological and immunohistochemical characteristics, the tumours were classified as canine ILC.

Skin biopsies from five Border terriers with histologically confirmed idiopathic, generalized sebaceous gland hyperplasia (Group A) were compared morphometrically to those from four unaffected Border terriers (Group B) and the unaffected dogs to biopsies from four other terrier breeds (Group C). Dogs in Group A had significantly higher numbers of sebaceous gland lobules per hair follicle than those in Group B (P = 0.020) but there was no significant difference between Groups B and C. The total sebaceous gland lobular area per hair follicle was significantly higher in dogs in Group A than Group B (P = 0.020) but there were no differences between Groups B and C. There were no significant differences in the size of the individual sebaceous gland lobules. There were no significant differences in the total number of basal or mature sebocytes between Groups A and B but significantly lower numbers of both cell types were seen in Group C compared to Group B. There were significantly more basal sebaceous cells undergoing mitosis in dogs in Group A than Group B (P = 0.017) but no significant difference between Groups B and C. These results indicate that the physical signs of sebaceous gland hyperplasia are caused by an increase in the number of sebaceous gland lobules and total lobular area. Border terriers may be genetically predisposed to the development of idiopathic generalized sebaceous gland hyperplasia compared with other dog breeds but also to sebaceous gland hyperplasia secondary to other dermatopathies.Les biopsies cutanées de cinq Border terriers présentant un diagnostic histologique confirmé d’hyperplasie généralisée des glandes sébacées (Groupe A) ont été comparées à celles de quatre Border terriers sains (Groupe B) et les biopsies de ces derniers ont été comparées à celles de quatre terriers d’autres races (Groupe C). Les chiens du Groupe A avaient significativement un nombre plus élevé de lobules de glandes sébacées par follicule pileux que ceux des Groupes B et C. L’aire totale des lobules des glandes sébacées par follicule pileux était significativement plus grande pour les chiens du Groupe A que pour le Groupe B (P = 0.020) mais il n’y avait aucune différence entre les Groupes B et C. Il n’y avait aucune différence significative dans le nombre total de sébocytes basaux ou matures entre les Groupes A et B mais un nombre significativement plus faible des deux types cellulaires a été observé pour le Groupe C par rapport au Groupe B. Il y avait significativement plus de cellules sébacées basales en mitose chez les chiens du Groupe A que du Groupe B (P = 0.017) mais aucune différence significative entre les Groupes B et C. Ces résultats suggèrent que les signes cliniques d’hyperplasie des glandes sébacées sont dus à une augmentation du nombre et de la surface totale des lobules des glandes sébacées. Les Border terriers pourraient être génétiquement prédisposés au développement d’hyperplasie généralisée des glandes sébacées en comparaison avec d’autres races mais aussi, à une hyperplasie des glandes sébacées secondaire à d’autres dermatoses.Se compararon mediante morfometría biopsias de piel de cinco Border Terriers con diagnóstico de hiperplasia generalizada de glándulas sebáceas (grupo A) con muestras de perros Border Terrier no afectados (grupo B), y se compararon los perros no afectados con perros no afectados de otras razas Terrier (grupo C). Los perros del grupo A tenían un numero significativamente mayor de lóbulos de glándulas sebáceas por folículo piloso que los animales del grupo B (P = 0.020) pero no hubo diferencias significativas entre los animales de los grupos B y C. El área total de glándulas sebáceas por folículo piloso fue significativamente mayor en animales del grupo A que en animales del grupo B (P = 0.020) pero no hubo diferencias significativas entre los grupos B y C. No hubo diferencias significativas en el tamaño de los lóbulos de las glándulas sebáceas individuales. No hubo diferencias significativas en el número total de sebocitos basales o maduros entre los grupos A y B, pero hubo un número significativamente menor de ambos tipos celulares en el grupo C comparado con el grupo B. Se observaron más células sebáceas basales en mitosis en perros del grupo A que en perros del grupo B (P = 0.017) pero no hubo diferencias significativas entre los perros del grupo B y C. Estos resultados indican que los signos físicos de hiperplasia de glándulas sebáceas están causados por un aumento del número de lóbulos sebáceos y del área total de glándulas sebáceas. Perros de raza Border Terrier pueden estar genéticamente predispuestos a desarrollar hiperplasia generalizada idiopática de glándulas sebáceas comparado con otras razas, y también a desarrollar hiperplasia sebácea secundaria a otras dermatopatías.Hautbiopsien von fünf Borderterriern mit histologisch bestätigter idiopathischer generalisierter Talgdrüsenhyperplasie (Gruppe A) wurden morphometrisch mit denen von vier nicht betroffenen Borderterriern (Gruppe B) und diese nicht betroffenen Hunde mit Biopsien von vier anderen Terrierrassen (Gruppe C) verglichen. Die Hunde in Gruppe A hatten eine signifikant höhere Anzahl an Talgdrüsenlappen pro Haarfollikel als jene in Gruppe B (P = 0.020), aber zwischen Gruppe B und C bestand kein signifikanter Unterschied. Die gesamte lobuläre Bereich der Talgdrüsen pro Haarfollikel war bei Hunden der Gruppe A signifikant höher als bei Hunden der Gruppe B (P = 0.020), aber zwischen Gruppe B und C bestand kein signifikanter Unterschied. Es bestanden keine signifikanten Unterschiede in der Größe der individuellen Talgdrüsenlappen. Es bestanden keine signifikanten Unterschiede in der Gesamtzahl der basal gelegenen oder reifen Sebozyten zwischen Gruppe A und B, aber es wurde eine signifikant niedrigere Anzahl beider Zelltypen in Gruppe C im Vergleich zu Gruppe B gefunden. Es machten signifikant mehr basal gelegene Talgdrüsenzellen in Gruppe A als in Gruppe B eine Mitose durch (P = 0.017), aber zwischen Gruppe B und C bestand kein signifikanter Unterschied. Diese Ergebnisse weisen darauf hin, dass die physischen Anzeichen einer Talgdrüsenhyperplasie durch die Zunahme der Anzahl der Talgdrüsenlappen und dem gesamten lobulären Bereich der Talgdrüsen verursacht werden. Borderterrier könnten im Vergleich zu anderen Hunderassen genetisch zur Entwicklung von idiopathischer generalisierter Talgdrüsenhyperplasie, aber auch zu Talgdrüsenhyperplasie sekundär zu anderen Dermatopathien prädisponiert sein.

Phosphatase and tensin homolog (PTEN) belongs to the group of gatekeeper tumor suppressor genes and is involved in multiple mechanisms leading to cellular defense against neoplastic transformation and progression. Twenty-four dogs and 17 cats were submitted to a 2-year follow-up study, and clinicopathologic features were recorded and compared with immunohistochemical PTEN staining. PTEN-negative status occurred in 33% of canine and 76% of feline mammary carcinomas. In canine mammary carcinomas, there was a significant (P < .05) correlation between loss of PTEN protein expression and simple carcinoma histotype, lymphatic vessel invasion, lymph node metastases, distant organ metastases, tumor dedifferentiation, tumor recurrence, and shorter overall survival. In feline mammary tumors, a significant correlation between loss of PTEN protein expression and lymphatic vessel invasion was found. Loss of PTEN expression could be a useful prognostic marker in canine mammary carcinomas.

Inflammatory mammary carcinoma (IMC) is the most aggressive type of mammary tumour in the dog and has been proposed as a model for human inflammatory breast cancer. The aim of this study was to investigate angiogenesis in canine IMC by immunohistochemical assessment of the expression of vascular endothelial growth factor (VEGF). Tissues from 19 cases of IMC were compared with tissues from 27 cases of invasive mammary carcinoma without inflammation (non-IMC). Immunohistochemical expression of oestrogen receptor (ER), progesterone receptor (PR) and HER-2 receptor was also assessed. VEGF was strongly expressed in all IMCs and the percentage of VEGF-immunoreactive tumour cells was significantly higher in IMC than in non-IMC (P = 0.02). There was no difference in HER-2 receptor expression between IMC and non-IMC, and no IMC expressed ER or PR. These results suggest that VEGF may contribute to the high angiogenic phenotype of canine IMC and that this expression may underlie the tendency towards local and systemic metastasis of these tumours.

An innovative image editing system based on a sequential immunoperoxidase–immunofluorescence technique on routine histological sections is described. With this technique it is possible to identify different antigens in different cells, as well as co-localised antigens in the same cell. The method uses digital image editing to mix two independently captured images into one merged image. The technique was performed with indirect immunoperoxidase, followed by sequential indirect immunofluorescence, digital image acquisition and image editing. Multiple staining examples using anti-cytokeratin, anti-vimentin and anti-calbindin antibodies on canine skin and cerebellum, and feline pleural mesothelioma sections were performed in order to investigate the capabilities of the proposed technique. Our data demonstrated that this method can be easily used to assess multiple protein staining studies with minimum laboratory equipment, and that it allows a better structural visualisation of the tissue morphology compared to double immunofluorescence. Moreover, in contrast to double-immunoperoxidase, with this method it is possible to easily co-localise two different antigens in the same cell compartment.