A.L. Saraiva

Presence and significance of Helicobacter spp. in the gastric mucosa of Portuguese dogs.

BackgroundNon-Helicobacter pylori Helicobacters (NHPH) are also able to cause disease in humans. Dogs are a natural reservoir for many of these species. Close and intense human contact with animals has been identified as a risk factor and therefore, an important zoonotic significance has been attributed to NHPH.MethodsTo determine the prevalence of Helicobacter species and the gastric histopathological changes associated, gastric mucosa samples of 69 dogs were evaluated.ResultsOnly one dog presented a normal histopathological mucosa with absence of spiral-shaped organisms. A normal gastric mucosa and the presence of spiral-shaped bacteria was observed in two dogs. All remaining animals presented histopathological changes representative of gastritis. Helicobacter species were detected in 60 dogs (87.0%) by at least one detection method. Histological, histochemical and immunohistochemical evaluations revealed that Helicobacter spp. were present in 45 (65.2%), 52 (75.4%) and 57 (82.6%) dogs, respectively. Spiral-shaped bacteria were detected by qPCR analysis in 33 (47.8%) dogs. H. heilmannii-like organisms were identified in 22 animals (66.7%) and predominantly in the antral gastric region. H. salomonis was the second most prevalent species (51.5%) although it was mainly found in association with other Helicobacter spp. and in the body gastric region. H. bizzozeronii and H. felis were less frequently detected.ConclusionsIt was concluded that, despite the high incidence and worldwide distribution of gastric NHPH in dogs, the presence of specific Helicobacter species may vary between geographic regions. NHPH infections were significantly accompanied by mild to moderate intraepithelial lymphocyte infiltration and mild to moderate gastric epithelial injury, but a clear relationship between gastritis and Helicobacter infection could not be established.

An immunohistochemical study on the expression of sex steroid receptors, Ki-67 and cytokeratins 7 and 20 in feline endometrial adenocarcinomas

BackgroundEndometrial adenocarcinomas are a rare type of tumour in cats. Though different morphologies have been reported, the most frequent histological type of feline endometrial adenocarcinoma (FEA) is the papillary serous. Characterization of molecular markers expression in FEA may contribute to clarify the pathogenesis of these tumours and to assess the differences between normal endometrium and FEA regarding the expression pattern of several proteins. Therefore, this study aimed to evaluate the immunohistochemical profile of a wide panel of antibodies (specific for ER-α, PR, Ki-67, CK7 and CK20) in twenty-four cases of FEA. Comparisons were made between FEA and feline normal cyclic endometrium in follicular (n = 13) and luteal (n = 10) stages. Except for Ki-67, all other molecular markers were assessed independently for the intensity of immunolabeling and for the percentage of cells expressing the protein.ResultsThis study showed that in FEA a loss of expression occurs for ER-α (P ≤ 0.0001) and less markedly also for PR. The lost in sex steroid receptors concerns a decrease in both the proportion of labelled cells and the intensity of immunolabelling (P = 0.002 and P = 0.024, respectively). Proliferative activity, estimated via Ki-67 immunoreaction, significantly increased in FEA as compared to normal endometrium (P ≤ 0.0001). Feline endometrial adenocarcinomas maintained the CK7+/CK20+ status of normal endometrium. However, FEA showed decreased CK7 intensity of labelling compared to normal endometria (P ≤ 0.0001) and loss of CK20 expression, both in intensity (P ≤ 0.0001) and in percentage of positive cells (P = 0.01), compared to normal tissues.ConclusionsData gathered in this study suggest that proliferation in FEA accompanies ER-α down-regulation, possibly following activation of pathways mediated by local growth factors. Moreover, FEA retains combined expression of CK7 and CK20, as evidenced in normal endometrial epithelia, although a decrease in CK7 expression was observed.

Proliferative Endometrial Lesions Hidden behind the Feline Pyometra

The literature refers to pyometra as the most important pathology in the feline uterus, which is often associated with cystic endometrial disease (cystic endometrial hyperplasia/ pyometra complex or CEH-Pyo). The etiology of pyometra is complex and probably mul‐ tifactorial, but hormonal influences are suggested to play an important role in the patho‐ genesis. Progestagen-based contraceptives may be risk factors for the CEH-Pyo syndrome, for endometrial adenocarcinoma and also to mammary tumors in this species. The histopathological descriptions of pyometra include an enlarged uterus containing purulent fluid, variable endometrial infiltration of neutrophils and bacterial colonization. The degree of hyperplasia of endometrial glands is variable, and frequently the endome‐ trium becomes atrophic. The severity of endometritis is variable. Thereby, the type of in‐ flammatory cells infiltrating the uterine wall or lumen varies accordingly and may include neutrophils, macrophages, plasma cells and lymphocytes. The clinical diagnosis of pyometra is often based on the clinical signs and the physical examination, supported by ultrasound findings. The surgical excision of the uterus is the recommended treatment when the animal is not intent for breeding, as most pyometra clinical signs resolve after ovariohysterectomy. Nevertheless, our clinical practice demonstrated that, in cats, pyometra often masks other uterine conditions that may present a worst prognosis and may interfere with the expect‐ ed outcome. Thus, although seldom requested, the pathological analysis of the uterus with pyometra should be performed following surgery, even if significant macroscopic alterations are not visible, as one frequent finding in pyometra specimens is the co-exis‐ tence of feline endometrial adenocarcinoma (FEA). FEA is usually described as a rare pathology in cats, but recent descriptions suggest that it may be more frequent than thought. Some morphological and clinical features of FEA, as well as molecular markers, have been recently described. Moreover, age is not an ade‐ quate factor for triage, since some FEA cases were described in young animals, prompt‐ ing pathologists, clinicians and researchers into this new reality.