Spatial distribution of Collembola in presence and absence of a predator

Many Collembola species are characterised by an aggregative behaviour, which is closely related to communication and co-ordination between individuals. In spite of a general heavy predation pressure, a large number of Collembola is found in soil suggesting that they have developed defence strategies against predators.

This study investigates changes in spatial structure of gregarious Collembola species in presence of a predator. It is analysed if the gregarious lifestyle of Collembola populations functions as a defence strategy against predation. In presence of a predator distances between individuals in the Collembola species Folsomia candida and Heteromurus tetrophthalmus became closer, reducing the risk of individuals to be captured by predators. On the contrary, Onychiurus sinensis specimens, which were never caught probably because of the extrusion of repelling fluids by means of their pseudocelli, moved away from each another. Besides being a successful chemical defence against predation, repelling fluid secretion may effectively repel conspecifics, thereby keeping individuals at greater distance.     

An integrated approach for cetacean knowledge and conservation in the central Mediterranean Sea using research and social media data sources

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Tumour‐infiltrating lymphocytes in canine melanocytic tumours: An investigation on the prognostic role of CD3+ and CD20+ lymphocytic populations

The study of the immune response in several types of tumours has been rapidly increasing in recent years with the dual aim of understanding the interactions between neoplastic and immune cells and their importance in cancer pathogenesis and progression, as well as identifying targets for cancer immunotherapy. Despite being considered one of the most immunogenic tumour types, melanoma can progress in the presence of abundant lymphocytic infiltration, therefore suggesting that the immune response is not able to efficiently control tumour growth. The purpose of this study was to investigate whether the density, distribution and grade of tumour‐infiltrating lymphocytes (TILs) in 97 canine melanocytic tumours is associated with histologic indicators of malignancy and can be considered a prognostic factor in the dog. As a further step in the characterization of the immune response in melanocytic tumours, an immunohistochemical investigation was performed to evaluate the two main populations of TILs, T‐lymphocytes (CD3⁺) and B‐lymphocytes (CD20⁺). The results of our study show that TILs are present in a large proportion of canine melanocytic tumours, especially in oral melanomas, and that the infiltrate is usually mild. The quantity of CD20⁺ TILs was significantly associated with some histologic prognostic factors, such as the mitotic count, the cellular pleomorphism and the percentage of pigmented cells. Remarkably, a high infiltration of CD20⁺ TILs was associated with tumour‐related death, presence of metastasis/recurrence, shorter overall and disease‐free survival, increased hazard of death and of developing recurrence/metastasis, hence representing a potential new negative prognostic factor in canine melanocytic tumours.     

Multiple dermoid sinuses of type Vb and IIIb on the head of a Saint Bernard dog

Dermoid sinus, a congenital malformation of neural tube development, has been reported in humans and several animal species including dogs. It is typically found in the dorsal midline and commonly occurs in the Rhodesian Ridgeback breed. A case of multiple dermoid sinuses in the fronto-occipital region is described. An 11-month-old, intact female Saint Bernard dog was presented with a 2 day history of discharge from a large irregular subcutaneous mass in the fronto-occipital region. The dog was otherwise healthy. The dog had two circular skin lesions (approximately 4 × 4 and 4 × 2 cm diameter) surrounded by multiple irregular elevated masses. The masses had multiple small openings on the skin surface with tufts of hair protruding from the apertures. The masses were surgically removed, and the diagnosis of multiple dermoid sinuses was confirmed by histological examination. Histopathological examination showed multiple, variably sized, spherical to tubular cysts expanding the dermis and subcutis. Cysts were filled with hair shafts and lamellar keratin and were lined by a stratified squamous epithelium. Sebaceous and apocrine gland adnexal structures were also observed. To the best of our knowledge, this is the first reported case of multiple dermoid sinuses of two different types in the head of a Saint Bernard dog.