Mast cells have for a long time been known to accumulate around tumors (Maltby et al., 2009). Studies show that they may be important and sometimes essential in tumor angiogenesis, tumor growth and metastasis of tumors (Soucek, et al., 2007; Xiang et al., 2010). In an expression array study (Wensman et al, submitted manuscript) performed on mouse mast cells exposed to tumor conditioned medium, the gene 4-1BB was among the most up-regulated genes compared to control medium. 4-1BB codes for a membrane receptor protein of the tumor necrosis factor superfamily and has been shown to be important in T cell regulation in tumor diseases. This study was performed to investigate if human mast cells up-regulate 4-1BB when they get exposed to tumor conditioned medium.

The complexity of the mast cell is becoming more prominent. From being the cell recognized just to contribute to allergic inflammation it is now also associated with wound healing, protection against tumor growth and in recognition and defense against a wide range of pathogens. The location of the mast cell in the barrier between the external and internal environment of the body enables the cell to quickly respond to invading bacteria, virus and parasites. Diarrhea due to Escherichia coli infection, listeriosis, toxoplasmosis, Newcastle disease and bovine respiratory syncytial virus are examples of mast cell activating diseases that can affect animals in, as well as outside, the agricultural sector. Additionally, ticks and tick-borne diseases are of concern.

Inflammatory airway disease (IAD) is a respiratory disorder that most commonly affects young horses performing at a high level. The clinical signs are often mild but the disorder can cause a marked decrease in performance to a point where the horse has to be taken of training and competing. The aetiology underlying IAD is not yet fully understood. One current theory is that a type I-hypersensitivity reaction due to allergens in the environment is the cause in some horses. The most reliable diagnostic method is a bronchoalveolar lavage (BAL) since it reflects the inflammatory status in the most distal parts of the lungs, which are affected in IAD.

Photodynamic therapy is a relatively new treatment for superficial squamous cell carcinoma in cats. There are no publications indicating that the method is being used in veterinary practice in Sweden at the present time. The method uses the interaction between a photosensitive agent which has been administered to the tumor area, light of a wavelength that can be absorbed by the photosensitiser and the presence of oxygen. In this study photodynamic treatments were performed at the Queen?s Veterinary School Hopital of Cambridge University between 1998 and 2002.

Atopic dermatitis (AD) is a complex, often lifelong allergic disease affecting around 10 % of both dogs and humans. The hallmark symptom is severe pruritus, causing a lowered quality of life. Mast cells (MCs) are known to play an important part of the immunopathogenesis, promoting a faulty T helper cell type 2 (Th-2) response which follows by a production of specific immunoglobulin E (IgE) antibodies towards environmental allergens (Ag). To further investigate the role of MCs and its mediators in the progression of AD, a low-calcemic vitamin D3 analog (MC903) was used to induce AD-like symptoms locally on the ears of two different knock-out (KO) mouse strains. The first strain was Wsh-/- mice deficient in MCs.

This literature study aims to examine the existence of cancer stem cells in breast cancer. The cancer stem cell theory states that there is a hierarchical organization within a tumour, in which a small subpopulation of the cells can initiate new tumours and maintain tumour growth whilst the bulk of the tumour cannot. These tumour initiating cells have shown to possess many characteristics similar to those of adult stem cells, which is why they are often referred to as cancer stem cells. Both cell types have the capacity of asymmetric division and have shown to possess mechanisms of resistance to both apoptosis and cancer drugs. The cancer stem cell theory elucidates many biological aspects such as the heterogeneity of tumours and the relapse of many cancers after what appeared to be successful treatments.

Basal cell carcinoma (BCC) is the most common non-melanoma skin cancer. It can be divided in different subtypes. The most common type is superficial and is most frequently occurring on the trunk and on the face. In severe cases it can be difficult to differentiate basal cell carcinoma from other skin tumors, therefore a skin biopsy is conclusive diagnostic method. In terms of treatment, curettage is a common non-surgical treatment of basal cell carcinoma.

Pyometra, chronic purulent metritis in metoestrus, is a common disease in intact bitches. About 25% of all bitches in Sweden have contracted the disease before ten years of age. Clinical signs of the disease are varied, and the course may be either slow or acute. The diagnosis is most commonly made by radiographical or ultrasonographical examination of the abdomen in combination with blood biochemical and hematological analyses. The safest and most efficient treatment of pyometra is surgical ovariohysterectomy.There is room for improvement of both diagnostic tools and possible prognostic indicators for pyometra.Mast cells are large leucocytes, with granule that contain inflammatory mediators.

Mammary tumors are the most frequent type of tumors in bitches in Sweden. Many studies have been published concerning mammary tumors, but there is still much to be learned about this disease. One has, since some time ago, had the knowledge that addition to or removal of methyl groups to genes can inhibit or activate gene-expression. Methylation and demethylation is a normal phenomenon in the body and it is essential for the development and survival of the individual. The risk of developing a tumor disease is increased if the global methylationstatus is changed; if oncogenes demethylates (activates) or if tumor suppressor genes methylates (inactivates). In the human medicine one has seen that there are differences in methylationstatus between different tumors. In this study tumor and normal tissue from ten dogs were examined with regard to methylationstatus.

SAMMANFATTNINGDenna litteraturstudie har gjorts med syfte att utöka kunskapen om atopisk dermatit hos hund med fokus på mastcellens roll i immunopatogenesen. Atopisk dermatit är en relativt vanlig sjukdom som kan drabba alla hundar oavsett ras; den är oftast livslång och kräver visst arbete för att diagnosticera och behandla med gott resultat. Förutom att det är ett problem hos hundar, finns även ett nära samband med atopiska sjukdomar hos människa, och hundar fungerar som en bra modell för forskning på humansidan.Trots omfattande forskning, vet man fortfarande inte varför sjukdomen uppkommer. Många teorier finns kring den immunologiska bakgrunden, men stora delar är fortfarande okända. Att mastcellen spelar en nyckelroll är dock allmänt vedertaget.

The cell cycle is the time a cell spends between two cell divisions. The cell cycle includes several parallel processes, all of which must be completed before a cell is mature for dividing. In the first place, all subcomponents (RNA, protein and membrane lipids) need to double in quantity and this occurs continuously through the cell cycle. Furthermore, the genome and some chromosomal proteins must double and this take place during a limited interval in the middle of the cell cycle (S-phase). On either side of the S-phase are two "gaps" which is called G1 and G2. When the cell has passed a point in the G-phase they are irreversibly programmed to progress through the remaining of the cell cycle and will undergo the next cell division. When a cell have passed a point in the G1 phase, approximately four hours after mitosis, a normal cell is in a state of indecision.

The purpose of this essay was to review the literature and describe the patophysiology, diagnosis, microscopic and macroscopic appearance of aortic body tumors in dogs. The tumors originate from the chemoreceptor organs situated at the base of the heart. The chemoreceptor organs are neuroendocrine cells responsible for surveillance of changes in e.g. the blood pH. Aortic body tumors are rare and represent 7 % of the total cases of primary cardiac tumors in canines.

The dog has often served as a model animal for humans in scientific studies. This is due to the fact that dogs are susceptible to a wide range of diseases which also affect humans. One example is cancer, a condition that affects dogs as well as owners. Neoplastic diseases account for 18-23 % of all deaths in dogs (Bonnet et al., 2005 and Jagielski et al., 2002). Mammary tumor, or tumor of the breast, is the most common tumor form in intact dogs and women (Im et al., 2013). Mammary tumors originate in the udder, and are classified according to their histological characteristics.

The development of quantitative, real-time PCR (qPCR) combined with the mapping of the canine genome opens new possibilities in veterinary medicine. This method provides a quick and accurate quantification of the expression of a specific gene at a given point in time and thereby also information of how the gene expression for a certain protein is influenced by various conditions and diseases. One possible area of application is identifying bio markers for cancer. Recently the protein serglycin (the core protein of an intracellular proteoglycan) was found to act as a selective marker for the disease acute myeloid leukemia in humans (Niemann et al, 2007). Serglycin is produced by most hematopoietic cells, although mast cells account for the largest amount of serglycin.

Today?s cell phones include more and more functionality, it is no longer uncommon to be able to connect to the Internet or take photos with the cell phone. In this thesis the question is if the cell phone users are interested in this new functionality. Are there people who are interested in a cell phone that in this thesis is called ?Basmobilen? (the entry level phone), which include the following functions; phone call, SMS, phone book, calling lists, clock and the possibility to change the call signal.