Hemangiosarcoma esplénico con metástasis óseas : descripción de un caso y revisión de diversos aspectos clínicos

Se diagnosticó un caso de metástasis ósea de un hemangiosarcoma esplénico subclínico, produciendo una cojera severa y continuada. El tumor produjo una fractura patológica en el húmero proximal, haciéndose intraarticular e invadiendo la membrana sinovial de la articulación escápulo-humeral. La importancia de la artrocentesis y análisis del líquido sinovial como técnicas diagnósticas auxiliares en la investigación de patologías articulares y periarticulares es puesta de manifiesto en este caso. Asimismo, se hace una revisión de diversos aspectos clínicos del hemangiosarcoma canino.A case of osseous metastasis from an asymptomatic splenic haemangiosarcoma, which produced asevere and continous lameness, was diagnosed. The tumour produced a pathological fracture in the proximal humerus and invaded the synovial membrane of the shoulder joint. The value of arthrocentesis and synovial fluid analysis as auxiliary diagnostic techniques in the investigation of articular and periarticular pathologies is stressed. Furthermore, an overview of several clinical aspects of the canine haemangiosarcoma is discussed

Canine tonsillar polyps: characteristics, classification and review of the pathogenesis

Canine tonsillar polyps are uncommon. We describe 14 tonsillar polyps in dogs and review their classification and pathogenesis. All dogs were adult (3-13 years old). Females (10/14) were more affected than males (4/14). Most of the lesions were asymptomatic (10/14). All lesions were unilateral, pedunculated (9/14) or sessile (5/14), with a smooth (12/14) or papillary/verrucous surface (2/14). Histologically, polyps consisted of benign proliferation of lymphatic vessels, blood vessels, fibrous tissue and lymphoid tissue in variable proportions, with occasional adipose tissue (4/14). According to the main stromal components, polyps were categorized as lymphangiomatous (5/14), lymphangiolipomatous (2/14), lymphangiofibromatous (2/14), angiofibromatous (1/14), angiofibrolipomatous (1/14), lymphoid (2/14), and myxomatous (1/14). As the pathogenesis of these polyps remains unclear, we propose to replace the term inflammatory tonsillar polyp by a morphological diagnosis based on the stromal characteristics of the lesions. Simple surgical excision was curative in the 9 cases with available follow-up information

Listeria pathogenesis and molecular virulence determinants

The gram-positive bacterium Listeria monocytogenes is the causative agent of listeriosis, a highly fatal opportunistic foodborne infection. Pregnant women, neonates, the elderly, and debilitated or immunocompromised patients in general are predominantly affected, although the disease can also develop in normal individuals. Clinical manifestations of invasive listeriosis are usually severe and include abortion, sepsis, and meningoencephalitis. Listeriosis can also manifest as a febrile gastroenteritis syndrome. In addition to humans, L. monocytogenes affects many vertebrate species, including birds. Listeria ivanovii, a second pathogenic species of the genus, is specific for ruminants. Our current view of the pathophysiology of listeriosis derives largely from studies with the mouse infection model. Pathogenic listeriae enter the host primarily through the intestine. The liver is thought to be their first target organ after intestinal translocation. In the liver, listeriae actively multiply until the infection is controlled by a cell-mediated immune response. This initial, subclinical step of listeriosis is thought to be common due to the frequent presence of pathogenic L. monocytogenes in food. In normal indivuals, the continual exposure to listerial antigens probably contributes to the maintenance of anti-Listeria memory T cells. However, in debilitated and immunocompromised patients, the unrestricted proliferation of listeriae in the liver may result in prolonged low-level bacteremia, leading to invasion of the preferred secondary target organs (the brain and the gravid uterus) and to overt clinical disease. L. monocytogenes and L. ivanovii are facultative intracellular parasites able to survive in macrophages and to invade a variety of normally nonphagocytic cells, such as epithelial cells, hepatocytes, and endothelial cells. In all these cell types, pathogenic listeriae go through an intracellular life cycle involving early escape from the phagocytic vacuole, rapid intracytoplasmic multiplication, bacterially induced actin-based motility, and direct spread to neighboring cells, in which they reinitiate the cycle. In this way, listeriae disseminate in host tissues sheltered from the humoral arm of the immune system. Over the last 15 years, a number of virulence factors involved in key steps of this intracellular life cycle have been identified. This review describes in detail the molecular determinants of Listeria virulence and their mechanism of action and summarizes the current knowledge on the pathophysiology of listeriosis and the cell biology and host cell responses to Listeria infection. This article provides an updated perspective of the development of our understanding of Listeria pathogenesis from the first molecular genetic analyses of virulence mechanisms reported in 1985 until the start of the genomic era of Listeria research

Enhancing player engagement through game balancing in digitally augmented physical games

Game balancing can be used to compensate for differences in players' skills, in particular in games where players compete against each other. It can help providing the right level of challenge and hence enhance engagement. However, there is a lack of understanding of game balancing design and how different game adjustments affect player engagement. This understanding is important for the design of balanced physical games. In this paper we report on how altering the game equipment in a digitally augmented table tennis game, such as the table size and bat-head size statically and dynamically, can affect game balancing and player engagement. We found these adjustments enhanced player engagement compared to the no-adjustment condition. The understanding of how the adjustments impacted on player engagement helped us to derive a set of balancing strategies to facilitate engaging game experiences. We hope that this understanding can contribute to improve physical activity experiences and encourage people to get engaged in physical activity

Digitally Augmenting Sports: An Opportunity for Exploring and Understanding Novel Balancing Techniques

Using game balancing techniques can provide the right level of challenge and hence enhance player engagement for sport players with different skill levels. Digital technology can support and enhance balancing techniques in sports, for example, by adjusting players' level of intensity based on their heart rate. However, there is limited knowledge on how to design such balancing and its impact on the user experience. To address this we created two novel balancing techniques enabled by digitally augmenting a table tennis table. We adjusted the more skilled player's performance by inducing two different styles of play and studied the effects on game balancing and player engagement. We showed that by altering the more skilled player's performance we can balance the game through: (i) encouraging game mistakes, and (ii) changing the style of play to one that is easier for the opponent to counteract. We outline the advantages and disadvantages of each approach, extending our understanding of game balancing design. We also show that digitally augmenting sports offers opportunities for novel balancing techniques while facilitating engaging experiences, guiding those interested in HCI and sports