Serological Evidence of Rickettsia Exposure among Patients with Unknown Fever Origin in Angola, 2016-2017.

Spotted fever group Rickettsia (SFGR) is one among the aetiologies that cause fever of unknown origin in Angola. Despite their occurrence, there is little information about its magnitude in this country either because it is misdiagnosed or due to the lack of diagnostic resources. For this purpose, eighty-seven selected malaria- and yellow fever-negative serum specimens collected between February 2016 and March 2017 as part of the National Laboratory of Febrile Syndromes, from patients with fever (≥37.5°C) for at least 4 days and of unknown origin, were screened for Rickettsia antibodies through an immunofluorescence assay (IFA). Serological results were interpreted according to the 2017 guidelines for the detection of Rickettsia spp. Three seroreactive patients had detectable IgM antibodies to Rickettsia with an endpoint titre of 32 and IgG antibodies with endpoint titres of 128 and 256. These findings supported a diagnosis of Rickettsia exposure amongst these patients and highlight that rickettsioses may be among the cause of unknown febrile syndromes in Angola. Therefore, physicians must be aware of this reality and must include this vector-borne disease as part of aetiologies that should be considered and systematically tested in order to delineate appropriate strategies of diagnostic and control of Rickettsia in Angola.

Crenosoma Striatum in Lungs of European Hedgehogs (Erinaceus Europeus) from Portugal.

Crenosoma striatum is a host-specifi c metastrongiloid nematode causing respiratory tract disease in hedgehogs (Erinaceus europaeus). Since few studies have reported C. striatum in hedgehogs and little genetic data is available concerning this lungworm, this study aimed to determine the occurrence of C. striatum in a population sample of hedgehogs from Portugal, additionally providing morphological, histological and molecular data. From 2017 to 2018 a survey of infection was carried out in 11 necropsied hedgehogs. Worms were extracted from fresh lung tissues and microscopically evaluated. Molecular characterization of partial mitochondrial (12S rRNA) and nuclear (18S rRNA) genes was performed. The presence of lungworms in pulmonary tissues of five hedgehogs (45.5%) was detected. Morphological and histopathological analyses evidenced adult forms of nematodes consistent with C. striatum. Molecular characterization of 18S rRNA genes confirmed the classifi cation as C. striatum. Also, novel genetic data characterizing the mitochondrial (12S rRNA) gene of C. striatum is presented. This is the first report of C. striatum infection in hedgehogs of Portugal. The findings here reported provide new insights regarding the geographic distribution and the molecular identification of this lungworm species.

Immune Cells and Immunosenescence.

Aging is associated with progressive loss of physiological integrity, leading to impaired physical and mental functions as well as increased morbidity and mortality. With advancing age, the immune system is no longer able to adequately control autoimmunity, infections, or cancer. The abilities of the elderly to slow down undesirable effects of aging may depend on the genetic background, lifestyle, geographic region, and other presently unknown factors. Although most aspects of the immunity are constantly declining in relation to age, some features are retained, while e.g. the ability to produce high levels of cytokines, response to pathogens by increased inflammation, and imbalanced proteolytic activity are found in the elderly, and might eventually cause harm. In this context, it is important to differentiate between the effect of immunosenescence that is contributing to this decline and adaptations of the immune system that can be quickly reversed if necessary.

Surgical sponge associated with platelets rich plasma in skin mesh grafts and layer in rabbits (Oryctolagus cuniculus) / Esponja cirúrgica associada com plasma rico em plaquetas em enxertos cutâneos em malha e camada em coelhos (Oryctolagus cuniculus)

The aim of this study was to evaluate of the efficacy of PRP employment associated with surgical sponges to improve the integration of the graft in the recipient bed. It was held at the Veterinary Hospital UNESP, Campus of Jaboticabal - SP, a study of 64 rabbits, divided into eight groups with eight animals. The groups were divided in control with saline solution 0,9%, control with PRP both without the sponge, surgical sponge with PRP, surgical sponge without PRP, and were used mesh and layer grafts in the respective groups. The data were submitted to statistical analysis (paired t-test, Kruskal-Wallis test, with subsequent use of the multiple comparison tests of Dunn, analysis of variance (F) test, Tukey test, P< 0.05). Edema and exudate with 3 and 3 and 7 days (P= 0,03 e P= 0,0049); coloring on the 14th day (P= 0,0001); cosmetic appearance on the 7th and 14th day (P= 0,0026 and P= 0,0001); mononuclear cells (P= 0,01) and polymorphonuclear (P= 0,01); fibroblast proliferation (P= 0,01); collagenous (P= 0,05); hemorrhage (P-007); necrosis and re-epithelialization (P= 0,2928 and P= 0,1). We concluded that the use of Platelet Rich Plasma Gel on skin grafts associated with a sponge as a compressive dressing promote the skin graft survival without a previous granulation tissue.(AU)

O objetivo deste estudo foi avaliar a eficácia do PRP associado com esponjas cirúrgicas na integração do enxerto ao leito receptor. Realizou-se, no Hospital Veterinário da Unesp, Jaboticabal, SP, um estudo com 64 coelhos, separados em oito grupos, com oito animais. Os grupos foram: Gprpc (PRP, sem esponja cirúrgica, enxerto camada), Gprpce (PRP, esponja cirúrgica, enxerto camada), Gcc (solução fisiológica 0,9%, sem esponja cirúrgica, enxerto camada), Gcce (solução fisiológica 0,9%, esponjas cirúrgicas, enxerto camada), Gprpm (PRP, sem esponja cirúrgica, enxerto malha), Gprpme (PRP, esponja cirúrgica, enxerto malha), Gcm (solução fisiológica 0,9%, sem esponja cirúrgica, enxerto malha) e Gcce (solução fisiológica 0,9%, esponjas cirúrgicas, malha). Os dados foram analisados pelo teste t emparelhado, Kruskal-Wallis, análise de variância, e teste de Tukey (P<0,05). Edema e exsudato presente com três e sete dias (P=0,03 e P=0,0049); coloração cianótica no 14º dia (P=0,0001); aspecto cosmético bom no sétimo e no 14º dia (P=0,00026 e P=0,0001); presença de células mononucleares (P=0,01) e polimorfonucleares (P=0,01); proliferação de fibroblastos discreta (P=0,01); colagenização intensa (P=0,05); hemorragia discreta (P=0,007); ausência de diferença significativa em necrose e reepitelização (P=0,2928 e P=0,1). Conclui-se que o emprego do PRP gel em enxertos cutâneos associando esponjas cirúrgicas como curativo compressivo favorece sua integração ao leito receptor sem a presença prévia de tecido de granulação.(AU)

Improvement of density resolution in short-pulse hard x-ray radiographic imaging using detector stacks.

We demonstrate that stacking several imaging plates (IPs) constitutes an easy method to increase hard x-ray detection efficiency. Used to record x-ray radiographic images produced by an intense-laser driven hard x-ray backlighter source, the IP stacks resulted in a significant improvement of the radiograph density resolution. We attribute this to the higher quantum efficiency of the combined detectors, leading to a reduced photon noise. Electron-photon transport simulations of the interaction processes in the detector reproduce the observed contrast improvement. Increasing the detection efficiency to enhance radiographic imaging capabilities is equally effective as increasing the x-ray source yield, e.g., by a larger drive laser energy.

Multiple Cutaneous Metastasis of a Malignant Leydig Cell Tumour in a Dog.

A testicular Leydig cell tumour associated with metastatic disease is reported in a dog. An enlarged testis and three cutaneous nodules resected from an 11-year-old golden retriever were submitted for histopathological examination. Both testicular and cutaneous lesions showed identical morphological and cytological changes. Immunohistochemical labelling for expression of inhibin-α and calretinin confirmed the Leydig origin of the cutaneous neoplastic population. Based on the morphological and immunohistochemical findings, a final diagnosis of multiple cutaneous metastasis of a malignant testicular Leydig cell tumour was made.

Canine Gastric Pathology: A Review.

Gastric disorders are common in dogs and are a major reason for veterinary consultation. In human medicine, the classification of gastric diseases based on histological features, genotypes and molecular phenotypes helps to better understand the characteristics of each subtype, and to improve early diagnosis, prevention and treatment. Canine gastric lesions often show strong histological similarities to their human counterparts. However, such conditions in the canine stomach are poorly studied and their cellular and molecular features are largely unknown. This article reviews the histopathological classification of inflammatory and neoplastic lesions of the canine stomach and provides an update on the application of molecular techniques within the field of canine gastric pathology. The canine disorders are compared with current knowledge of the equivalent human diseases.

Changes in c-erbB-2 Immunoexpression in Feline Endometrial Adenocarcinomas.

Human epidermal growth factor receptor type 2 (c-erbB-2), an oncoprotein with potential prognostic marker and therapeutic use, is overexpressed in several human and animal tumours. But information regarding this molecule in feline tumours is scarce. This study aimed to assess the changes in the immunohistochemical expression of c-erbB-2 in feline endometrial adenocarcinomas (FEA) compared to normal endometrium. An immunohistochemistry assay using a specific antibody against c-erbB-2 was performed in FEA samples (n = 34) and in normal endometrium in the follicular (FS; n = 12) and luteal (LS; n = 11) stages. In FEA, the c-erbB-2 immunoexpression was assessed in neoplastic epithelial cells whilst in normal endometria it was individually evaluated in the surface and the superficial and deep glandular epithelia (SE, SGE and DGE, respectively). In FS and in LS, all the epithelia were positive for c-erbB-2; positivity was higher in the SE and the SGE than in DGE. Twenty of the 34 FEA samples (58.8%) were positive for c-erbB-2 immunolabelling. Nevertheless, its expression was higher in all the epithelia in the FS compared to FEA (p ≤ 0.0001) or the LS (p = 0.016). The results presented herein suggest that c-erbB-2 molecule is differently expressed in the feline endometrium through the oestrous cycle and though it may also be involved in feline endometrial carcinogenesis, a question remains unanswered on the importance of additional pathways of epithelial proliferation in the neoplastic changes in feline endometrium.

VEGFR-2 expression in malignant tumours of the canine mammary gland: a prospective survival study.

Vascular endothelial growth factor receptor-2 (VEGFR-2) is the main receptor activated by vascular endothelial growth factor -A (VEGF-A) to promote tumour angiogenesis. Its clinical prognostic value has not been studied in canine mammary tumours (CMTs). Dogs with mammary cancer were enrolled in a survival study and the immunohistochemical expressions of VEGFR-2 and VEGF-A were analysed and associated with clinicopathological features. VEGFR-2 expression was associated with VEGF immunoreactivity in cancer cells, supporting the presence of an autocrine loop that may be involved in CMTs growth and survival. VEGFR-2 was also expressed by endothelial cells from tumour vasculature and positively associated with stromal matrix metalloproteinase-9 (MMP-9), suggesting the existence of a link between endothelial cells activation and up-regulation of matrix degrading proteins. Carcinosarcomas exhibited high VEGFR-2 expression suggesting that it may be one of the activated molecular pathways in this aggressive histological type and that VEGFR-2 inhibitors may constitute a potential treatment to improve the prognosis of these patients. Both VEGF and VEGFR-2 immunoreactivities were independent of patients' overall survival (OS) and disease-free survival (DFS).

Preventing E-cadherin aberrant N-glycosylation at Asn-554 improves its critical function in gastric cancer.

E-cadherin is a central molecule in the process of gastric carcinogenesis and its posttranslational modifications by N-glycosylation have been described to induce a deleterious effect on cell adhesion associated with tumor cell invasion. However, the role that site-specific glycosylation of E-cadherin has in its defective function in gastric cancer cells needs to be determined. Using transgenic mice models and human clinical samples, we demonstrated that N-acetylglucosaminyltransferase V (GnT-V)-mediated glycosylation causes an abnormal pattern of E-cadherin expression in the gastric mucosa. In vitro models further indicated that, among the four potential N-glycosylation sites of E-cadherin, Asn-554 is the key site that is selectively modified with ß1,6 GlcNAc-branched N-glycans catalyzed by GnT-V. This aberrant glycan modification on this specific asparagine site of E-cadherin was demonstrated to affect its critical functions in gastric cancer cells by affecting E-cadherin cellular localization, cis-dimer formation, molecular assembly and stability of the adherens junctions and cell-cell aggregation, which was further observed in human gastric carcinomas. Interestingly, manipulating this site-specific glycosylation, by preventing Asn-554 from receiving the deleterious branched structures, either by a mutation or by silencing GnT-V, resulted in a protective effect on E-cadherin, precluding its functional dysregulation and contributing to tumor suppression.

Immunohistochemical expression of cyclooxygenase-2 (COX-2) in feline endometrial adenocarcinoma and in normal and hyperplastic endometria.

Cyclooxygenase-2 (COX-2) is overexpressed in several human and animal neoplasms, including the human endometrial carcinoma. It has been suggested as a prognostic marker and a potential therapeutic target. This study aimed to (i) clarify histological aspects of feline endometrial adenocarcinomas (FEA) of the papillary serous type and (ii) characterize COX-2 immunohistochemical expression in normal, hyperplastic and neoplastic endometrium in this species. Archived paraffin-embedded tissue samples of 33 FEA, eight cystic endometrial hyperplasias (CEHs) and 21 samples of normal, healthy endometrium in the follicular (FS; n = 10) and luteal (LS; n = 11) stages were evaluated. Histological evaluation of haematoxylin and eosin-stained sections of the FEA revealed a papillary proliferation of neoplastic cells of serous type, accompanied by clear and multinucleated cells. Other architectural arrangements mainly included solid and tubular growth. Randomly distributed areas of necrosis within the tumours were commonly observed. Invasion of the myometrium, of the serosa and of the vascular and/or lymphatic vessels was not constant features. The mean number of mitoses was higher in FEA compared to non-neoplastic endometrium. COX-2 scores were lower in FEA (p = 0.003) and CEH (p = 0.05) when compared to normal epithelium (NE). The loss of the membrane apical reinforcement in epithelial cells was observed in FEA samples, which was accompanied by the dislocation of COX-2 labelling into the cytoplasm and the perinuclear area; in contrast, in epithelial cells in the healthy and hyperplastic endometria, the immunoreaction showed the characteristic pattern of apical membrane reinforcement, suggestive of the membrane polarization. COX-2 epithelial scores were higher in the FS than in the LS. No differences were found in stromal COX-2 expression between normal, CEH and FEA groups, but it was higher in the LS than in the FS. In summary, loss of COX-2 compartmentalization in neoplastic epithelial cells might be one of the molecular events underlying endometrial carcinogenesis.

Activation of Mammalian target of rapamycin in canine mammary carcinomas: an immunohistochemical study.

Mammalian target of rapamycin (mTOR) is a serine-threonine kinase involved in cell growth, proliferation and survival. Activation of mTOR has been reported in various tumour types, including human breast cancer; however, the expression of mTOR in canine mammary tumours has not been examined. In the present study, expression of the activated form of mTOR (phospho-mTOR [p-mTOR]) was examined immunohistochemically in five normal canine mammary glands, 45 canine mammary carcinomas and their corresponding metastatic lesions (n = 15). Phospho-mTOR was not expressed in normal canine mammary tissue, but cytoplasmic labelling was observed in 78% of canine mammary carcinomas. Two carcinomas had both cytoplasmic and nuclear labelling. No significant relationship was found between p-mTOR cytoplasmic expression and histological type or grading of carcinomas, degree of tubular formation, anisokaryosis, mitotic activity or lymph node metastasis. In all except one case, the expression pattern of p-mTOR in lymph node metastases was similar or decreased when compared with the primary lesion. The findings suggest that p-mTOR is involved in mammary carcinogenesis in dogs. However, p-mTOR cytoplasmic expression does not appear to be a prognostic indicator in canine mammary carcinomas, which may be related to its subcellular location in the neoplastic cells. Canine mammary tumours may provide a model for the development of innovative medical strategies involving mTOR inhibitors in human breast cancer.

Angiogenesis in spontaneous tumors and implications for comparative tumor biology.

Blood supply is essential for development and growth of tumors and angiogenesis is the fundamental process of new blood vessel formation from preexisting ones. Angiogenesis is a prognostic indicator for a variety of tumors, and it coincides with increased shedding of neoplastic cells into the circulation and metastasis. Several molecules such as cell surface receptors, growth factors, and enzymes are involved in this process. While antiangiogenic therapy for cancer has been proposed over 20 years ago, it has garnered much controversy in recent years within the scientific community. The complex relationships between the angiogenic signaling cascade and antiangiogenic substances have indicated the angiogenic pathway as a valid target for anticancer drug development and VEGF has become the primary antiangiogenic drug target. This review discusses the basic and clinical perspectives of angiogenesis highlighting the importance of comparative biology in understanding tumor angiogenesis and the integration of these model systems for future drug development.

Histopathological features of canine spontaneous non-neoplastic gastric polyps - a retrospective study of 15 cases.

Fifteen cases of canine gastric polyps, collected over a 4-year period, were investigated using gross inspection, histological procedures and immunohistochemical techniques for Helicobacter infection. No breed or sex predisposition was found for gastric polyps, although they occurred mainly in elderly animals. There were 9 pedunculated and 6 sessile polypoid growths, between 5 to 30 mm in diameter developed mainly in the pyloric region of the stomach. The most common type of gastric polyps was the hyperplastic one. The inflammatory type was identified in three cases. Foci of AB/PAS Goblet positive cells resembling intestinal metaplasia, mild dysplasia of gastric epithelium, well delimited calcified areas, islands of osteoid matrix and nematodes were present in some of these lesions. Histological examination of the adjacent gastric polyp (surrounding gastric mucosa) revealed a severe chronic inflammation in 13 cases and a high grade of Helicobacter species colonization in all cases, but Kendall test analysis showed no correlation between Helicobacter spp. colonization degree and gastritis scores (τ = 0289; p = 0.204). A significant correlation was found between Helicobacter spp. location and gastritis scores (τ = 0.497; p = 0.035). Immunohistochemistry performed with a polyclonal antibody confirmed Helicobacter spp. infection in all cases. Based on their morphology, Helicobacter pylori - like organisms were described in 3 of 15 cases. No high degree of dysplasia nor neoplasia were identified in these lesions. The etiology and pathogenesis of gastric polyps in dogs are still unknown, although a severe chronic antral gastritis may be a predisposing condition for development of gastric polyps in dogs.

Canine mammary tumors: a review and consensus of standard guidelines on epithelial and myoepithelial phenotype markers, HER2, and hormone receptor assessment using immunohistochemistry.

Although there have been several studies on the use of immunohistochemical biomarkers of canine mammary tumors (CMTs), the results are difficult to compare. This article provides guidelines on the most useful immunohistochemical markers to standardize their use and understand how outcomes are measured, thus ensuring reproducibility of results. We have reviewed the biomarkers of canine mammary epithelial and myoepithelial cells and identified those biomarkers that are most useful and those biomarkers for invasion and lymph node micrometastatic disease. A 10% threshold for positive reaction for most of these markers is recommended. Guidelines on immunolabeling for HER2, estrogen receptors (ERs), and progesterone receptors (PRs) are provided along with the specific recommendations for interpretation of the results for each of these biomarkers in CMTs. Only 3+ HER2-positive tumors should be considered positive, as found in human breast cancer. The lack of any known response to adjuvant endocrine therapy of ER- and PR-positive CMTs prevents the use of the biological positive/negative threshold used in human breast cancer. Immunohistochemistry results of ER and PR in CMTs should be reported as the sum of the percentage of positive cells and the intensity of immunolabeling (Allred score). Incorporation of these recommendations in future studies, either prospective or retrospective, will provide a mechanism for the direct comparison of studies and will help to determine whether these biomarkers have prognostic significance. Finally, these biomarkers may ascertain the most appropriate treatment(s) for canine malignant mammary neoplasms.

Mucin 6 and Tn antigen expression in canine mammary tumours: correlation with pathological features.

Overexpression of mucins is known to decrease cell-to-cell adhesion and thus to facilitate the invasion of cancer cells through the extracellular matrix. Mucin 6 (MUC6) is overexpressed and aberrantly O-glycosylated in human breast cancer, serving as a carrier for one of the most specific cancer-associated antigens, Tn antigen. Despite its relevance in breast cancer, MUC6 expression has not yet been characterized in canine mammary tumours (CMTs). The aims of this study were to assess the expression of MUC6 and Tn antigen in 55 benign and 77 malignant CMTs of different histological types and to investigate possible correlations with pathological features. MUC6 and Tn antigen were found to be significantly overexpressed in malignant compared with benign CMTs. MUC6 was significantly overexpressed in simple and complex carcinomas compared with simple and complex adenomas, respectively. When considering only the epithelial population, significant MUC6 overexpression was observed in carcinosarcomas when compared with benign mixed tumours. In addition, MUC6 was significantly overexpressed in simple compared with complex carcinomas. Finally, double-labelling immunofluorescence performed on seven malignant CMTs showed MUC6 and Tn co-expression. Therefore, MUC6 and Tn antigen overexpression is associated with malignant phenotypes of CMTs.

Impaired work functioning due to common mental disorders in nurses and allied health professionals: the Nurses Work Functioning Questionnaire.

PURPOSE: Common mental disorders (CMD) negatively affect work functioning. In the health service sector not only the prevalence of CMDs is high, but work functioning problems are associated with a risk of serious consequences for patients and healthcare providers. If work functioning problems due to CMDs are detected early, timely help can be provided. Therefore, the aim of this study is to develop a detection questionnaire for impaired work functioning due to CMDs in nurses and allied health professionals working in hospitals. METHODS: First, an item pool was developed by a systematic literature study and five focus group interviews with employees and experts. To evaluate the content validity, additional interviews were held. Second, a cross-sectional assessment of the item pool in 314 nurses and allied health professionals was used for item selection and for identification and corroboration of subscales by explorative and confirmatory factor analysis. RESULTS: The study results in the Nurses Work Functioning Questionnaire (NWFQ), a 50-item self-report questionnaire consisting of seven subscales: cognitive aspects of task execution, impaired decision making, causing incidents at work, avoidance behavior, conflicts and irritations with colleagues, impaired contact with patients and their family, and lack of energy and motivation. The questionnaire has a proven high content validity. All subscales have good or acceptable internal consistency. CONCLUSION: The Nurses Work Functioning Questionnaire gives insight into precise and concrete aspects of impaired work functioning of nurses and allied health professionals. The scores can be used as a starting point for purposeful interventions.

In vitro and in vivo chitosan membranes testing for peripheral nerve reconstruction.

Tissue regeneration over a large defect with a subsequent satisfactory functional recovery still stands as a major problem in areas such as nerve regeneration or bone healing. The routine technique for the reconstruction of a nerve gap is the use of autologous nerve grafting, but still with severe complications. Over the last decades several attempts have been made to overcome this problem by using biomaterials as scaffolds for guided tissue regeneration. Despite the wide range of biomaterials available, functional recovery after a serious nerve injury is still far from acceptable. Prior to the use of a new biomaterial on healing tissues, an evaluation of the host's inflammatory response is mandatory. In this study, three chitosan membranes were tested in vitro and in vivo for later use as nerve guides for the reconstruction of peripheral nerves submitted to axonotmesis or neurotmesis lesions. Chitosan membranes, with different compositions, were tested in vitro, with a nerve growth factor cellular producing system, N1E-115 cell line, cultured over each of the three membranes and differentiated for 48h in the presence of 1.5% of DMSO. The intracellular calcium concentrations of the non-differentiated and of the 48h-differentiated cells cultured on the three types of the chitosan membranes were measured to determine the cell culture viability. In vivo, the chitosan membranes were implanted subcutaneously in a rat model, and histological evaluations were performed from material retrieved on weeks 1, 2, 4 and 8 after implantation. The three types of chitosan membranes were a viable substrate for the N1E-115 cell multiplication, survival and differentiation. Furthermore, the in vivo studies suggested that these chitosan membranes are promising candidates as a supporting material for tissue engineering applications on the peripheral nerve, possibly owing to their porous structure, their chemical modifications and high affinity to cellular systems.

Immunohistochemical characterization of 13 canine renal cell carcinomas.

Canine renal cell carcinomas (RCCs) are uncommon aggressive tumors that occur mainly in middle-aged male dogs. Their histologic classification bears no relationship with prognosis, and little information is available concerning their immunohistochemical properties. In this retrospective study, formalin-fixed, paraffin-embedded tissues from 13 canine RCCs were retrieved from the archives, classified histologically, and evaluated immunohistochemically. The dogs were 7 males and 6 females (1 spayed) of 10 different breeds, averaging 8 years in age. The tumors were classified as papillary, tubulopapillary, papillary-cystic, solid, or sarcomatoid. All 13 tumors were immunohistochemically positive for uromodulin, 12 for c-KIT, 11 for vimentin, 9 for wide-spectrum-screening cytokeratins, 7 for cytokeratins AE1/AE3 and carcinoembryonic antigen, 4 for cytokeratins CAM 5.2, and 3 for CD10. All 3 solid RCCs expressed vimentin, c-KIT, and carcinoembryonic antigen and were negative for cytokeratins. All 7 papillary and tubulopapillary tumors expressed vimentin; 6 (86%), cytokeratins; and 6 (86%), c-KIT. Both papillary-cystic RCCs were positive for cytokeratins and c-KIT and negative for vimentin. These results indicate that the different histologic types of RCC have characteristic immunohistochemical profiles and that c-KIT may be involved in the pathogenesis of canine RCC.