Most experimental studies on leishmaniasis compare two different inbred strains of mice that are resistant or susceptible to one species of Leishmania. In the present study we characterized some cytokines and nitric oxide production as well as histological changes related to resistance and susceptibility in isogenic CBA mice infected with Leishmania major or Leishmania amazonensis. CBA mice are capable of controlling infection with L. major, but they succumb to infection with L. amazonensis. Cells from susceptible L. amazonensis-infected CBA mice produced interleukin (IL)-4 and IL-10 but no interferon (IFN)-gamma. On the other hand, resistant L. major-infected CBA mice produced IFN-gamma and IL-10, but IL-4 was detected only in the first week of infection. Histopathological studies showed patterns of tissue responses at the site of the infection and in the draining lymph nodes that correlated with resistance or susceptibility. Resistant mice showed a mixed inflammatory cell infiltration and granulomas in the lesions, whereas in susceptible mice only heavily parasitized macrophages were seen. Our results indicate an important role of the parasite species in determining the pattern of immune response. L. amazonensis induces a Th2-type immune response, whereas L. major induces a Th1-type response. These factors must be identified and taken into account in the strategies for the development of vaccines against leishmaniasis. The model presented here will be useful for the study of such factors.

Lipoma arborescens is a rare clinical condition characterized by mono or biarticular involvement of large joints, such as knees, hips, ankles, elbows, and shoulders. The aim of this case report is to describe an unusual case of lipoma arborescens affecting multiple large joints, mimicking rheumatoid arthritis. The patient, a 29-year-old woman had a history of intermittent arthritis of the wrists, knees, and ankles for at least 12 years. With the diagnosis of rheumatoid arthritis she had been on methotrexate (7.5 mg/wk) for the last 6 months along with different nonsteroidal anti-inflammatory drugs, without benefit. On physical examination a discreet joint swelling of the knees without effusion, gluteal muscle atrophy, and limited hip movements were observed. Laboratory tests presented normal acute phase reactants of inflammation as well as the rheumatoid factor, CK, and negative results for antinuclear, anti-DNA, anti-SSA/Ro, and anti-CCP (ELISA) antibodies. Magnetic resonance imaging of the knees and hips showed articular effusion and synovitis, and a pattern of lipoma arborescens. The histopathologic study confirmed the diagnosis. Knee arthroscopic synovectomy brought some improvement to joint mobility and pain.Although rare, this condition must be remembered in the presence of inflammatory arthropathy, particularly in the absence of response to clinical treatment, and absence of rheumatoid factor and anti-CCP antibodies, since the therapeutic strategy is radically different.

Many therapeutic modalities have been described for this disease. In this case report, we present a patient with MRS that was treated with thalidomide because of the identification of tumor necrosis factor a in the lesion by immunohistochemical analysis. This is the first reported detection of tumor necrosis factor a in an MRS lesion, as well the first reported use of thalidomide to treat this clinical condition.

An analysis of the extracellular matrix at the invasive front of squamous cell carcinoma of the oral cavity may improve the understanding of tumour cell matrix interactions during malignancy growth. Alterations in collagen I expression may influence cellular invasion and metastasis. In this work, 23 cases of squamous cell carcinoma were submitted to the Anneroth's malignancy grading system. H. E. and sirius red staining were used. Immuno-histochemical expression of collagen type I protein was observed in different malignancy scores. As a result, it was observed that the extracellular matrix in squamous cell carcinoma of the oral cavity shows different patterns of collagen I expression in low and high scores of malignancy.