Estudo retrospectivo (2007-2011) da casuística de cães com mastocitomas cutâneos atendidos em um hospital-escola

Neoplasms of mast cell origin are uncommon in most animal species. Although cases of cutaneous mastocitoma (CM) are rare in humans, it is the second most diagnosed cancer in dogs, accounting for approximately 20% of cutaneous tumors in this species. The age group most frequently affected is between eight and nine years, but it may occur in animals up to three weeks old. This study aimed to describe the epidemiological, hematological and histopathological characteristics of 73 dogs with cutaneous mast cell tumors attended between 2007 and 2011 by the Oncology Service of a teaching hospital in the state of São Paulo. Data collected included race, age, sex, weight, skin region affected, blood tests results at the first consultation and histopathological grading of dogs diagnosed with this neoplasia.

Inibidores de tirosina-quinase no tratamento de mastocitomas cutâneos em cães: revisão

The mast cell tumor (MCT) is the second most common type of tumor in dogs. It is characterized by uncontrolled proliferation of mast cells in the skin. Treatment involves surgical resection, chemotherapy and radiotherapy. Recently, new treatment protocols have been developed, such as the use of tyrosine kinase inhibitors. With the increasing knowledge about the genome and the evolution of methods in molecular genetics, drugs with specific molecular targets are surely going to become promising therapeutic modalities in the near future. Besides being involved in the normal cell cycle, some studies suggest that tyrosine kinases have a fundamental role in neoplastic processes. Therefore, some strategies such as the development of antibodies anti-receptors for tyrosine kinases and small-molecule tyrosine kinase receptor inhibitors have been developed in an attempt to inhibit tumor development. The purpose of this review is to describe the use of tyrosine kinase inhibitors in the treatment of mast cell tumors in dogs.

An immunocytochemical and in situ hybridization analysis of annexin 1 expression in rat mast cells: Modulation by inflammation and dexamethasone

The presence and localization of the anti-inflammatory protein annexin 1 (also known as lipocortin 1) in perivenular rat mast cells was investigated here. Using the rat mesenteric microvascular bed and a combination of morphologic techniques ranging from immunofluorescence to electron microscopy analyses, we detected the presence of annexin 1 in discrete intracellular sites, both in the nucleus and in the cytoplasm. In resting mast cells, most of the protein pool (approximately 80% of the cytosolic portion) was localized to cytoplasmic granules. In agreement with other cell types, treatment of rats with dexamethasone (0.2 mg/kg, ip) increased annexin 1 expression in mast cells, inducing a remarkable appearance of dusters of protein immunoreactivity. This effect was most likely the result of de novo protein synthesis as determined by an increase in mRNA seen by in situ hybridization. Triggering an ongoing experimental inflammatory response (0.3 mg of carrageenin, ip) increased annexin 1 mRNA and protein levels. In conclusion, we report for the first time the localization of annexin 1 in connective tissue mast cells, and its susceptibility not only to glucocorticoid hormone treatment, but also to an experimental acute inflammatory response.

Annexin 1: differential expression in tumor and mast cells in human larynx cancer

Annexin 1 protein (ANXA1) expression was evaluated in tumor and mast cells in human larynx cancer and control epithelium. The effect of the exogenous ANXA1 (peptide Ac 2-26) was also examined during the cellular growth of the Hep-2 human larynx epidermoid carcinoma cell line. This peptide inhibited the proliferation of the Hep-2 cells within 144 hr. In surgical tissue specimens from 20 patients with larynx cancer, ultrastructural immunocytochemistry analysis showed in vivo down-regulation of ANXA1 expression in the tumor and increased in mast cells and Hep-2 cells treated with peptide Ac2-26. Combined in vivo and in vitro analysis demonstrated that ANXA1 plays a regulatory role in laryngeal cancer cell growth. We believe that a better understanding of the regulatory mechanisms of ANXA1 in tumor and mast cells may lead to future biological targets for the therapeutic intervention of human larynx cancer. (c) 2007 Wiley-Liss, Inc.

Mast cells in the developing avian eye

Mast cells are present in the eye of Gallus domesticus, appearing in the anterior uvea in embryos at stage 39 HH (13th day). In hatching and adult birds, they are present in the sclera, uvea, pectinate Ligament, and conjunctiva. Mast cells are absent in the cornea, retina, and pecten oculi.Maturing mast cells in the anterior eye segment appear as round cells having eccentric nuclei and a few cytoplasmic metachromatic granules, whose fluorescence increases during development. Mature cells are more numerous in late development, and their cytoplasm is rich in metachromatic and intensely fluorescent granules. Ultrastructurally, maturing mast cells display progranules and a few electron dense and homogeneous granules on one side of the cell. Mast cells of adult birds possess homogeneous cytoplasmic granules, some of which display protuberances that penetrate hollows of adjoining granules. Heterogeneous granules exhibiting latticed and mottled patterns are also present. The existence of mast cells in the anterior eye segment indicates that these cells might perform a physiological role during development and in aqueous humor outflow. They might modulate exchanges between blood and aqueous humor through chemical mediators present in their granules. (C) 1996 Wiley-Liss, Inc.

Cellular recruitment and cytokine generation in a rat model of allergic lung inflammation are differentially modulated by progesterone and estradiol

We evaluated the role of estradiol and progesterone in allergic lung inflammation. Rats were ovariectomized (Ovx) and, 7 days later, were sensitized with ovalbumin (OA) and challenged after 2 wk with inhaled OA; experiments were performed 1 day thereafter. Ovx-allergic rats showed reduced cell recruitment into the bronchoalveolar lavage (BAL) fluid relative to sham-Ovx allergic rats, as was observed in intact allergic rats treated with ICI-182,780. Estradiol increased the number of cells in the BAL of Ovx-allergic rats, whereas progesterone induced an additional reduction. Cells of BAL and bone marrow (BM) of Ovx-allergic rats released elevated amounts of IL-10 and reduced IL-1 beta and TNF-alpha. BM cells of Ovx-allergic rats released increased amounts of IL-10 and lower amounts of IL-4. Estradiol treatment of Ovx-allergic rats decreased the release of IL-10 but increased that of IL-4 by BM cells. Estradiol also caused an increased release of IL-1 beta and TNF-alpha by BAL cells. Progesterone significantly increased the release of IL-10, IL-1 beta, and TNF-alpha by BAL cells and augmented that of IL-4 by BM cells. Degranulation of bronchial mast cells from Ovx rats was reduced after in vitro challenge, an effect reverted by estradiol but not by progesterone. We suggest that the serum estradiol-to-progesterone ratio might drive cellular recruitment, modulating the pulmonary allergy and profile of release of anti-inflammatory or inflammatory cytokines. The existence of such dual hormonal effects suggests that the hormone therapy of asthmatic postmenopausal women and of those suffering of premenstrual asthma should take into account the possibility of worsening the pulmonary conditions.

Aspectos anatômicos, fisiológicos e bioquímicos da enxerta de maracujazeiros sobre Passiflora cincinnata Mast

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Inflammation and cancer: role of Annexin A1 and FPR2/ALX in proliferation and metastasis in human laryngeal squamous cell carcinoma

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Spindle cell lipoma occurring in the buccal mucosa: an unusual location of this benign lipomatous neoplasm

Spindle cell lipoma is a benign lipomatous neoplasm, which rarely occurs in the oral cavity. The aims of this paper are to report a case of spindle cell lipoma located in buccal mucosa and discuss the main clinical, histological, and immunohistochemical findings of this entity. Thus, we report a 4-year history of an asymptomatic smooth surface nodule in an elderly Caucasian man with clinical hypothesis of fibroma. The histopathological examination showed spindle cells, mature adipose tissue, and many mast cells in a stroma of connective tissue presenting ropey collagen fibers bundles. After immunohistochemical analysis, the final diagnosis was spindle cell lipoma.