The conventional treatment for the most prevalent mycosis in Latin America, paracoccidioidomycosis (PCM), involves long periods of therapy that results in side effects and a high frequency of relapses. The search for a new, alternative... more
The conventional treatment for the most prevalent mycosis in Latin America, paracoccidioidomycosis (PCM), involves long periods of therapy that results in side effects and a high frequency of relapses. The search for a new, alternative treatment is necessary. Pb40 is an antigenic protein from P. brasiliensis fraction F0. This fraction has already been shown to have significant protective activity when used as a PCM vaccine in experimental models. The complete cDNA sequence corresponding to Pb40 was cloned into a pET-21a plasmid, expressed in E. coli with a his-tag and purified by affinity chromatography. The predicted protein sequence exhibited nearly 100% homology to a fragment of the hypothetical EF-hand domain containing protein of P. brasiliensis. Immunization with this recombinant protein was used together with chemotherapy in an attempt to improve PCM treatment. The combined drug/rPb40 treatment exhibited long-lasting control of PCM in the liver and spleen and largely preserved the tissue structures of these organs. Despite the lack of a reduction in CFUs in the group that received the combined treatment, there was a significant reduction in the size of the lesions in the lungs after 70 days of infection. At the same time, the IL-10 levels were higher in the treated mice than in the infected-only mice. Moreover, significant levels of rPb40-specific IgG antibodies were detected in the sera of immunized mice. Thus, the treatment protocol consisting of rPb40 immunization in addition to fluconazole chemotherapy showed an additive protective effect after intratracheal challenge, preventing fungal dissemination to other sites of infection and preventing relapses. These results provide new prospects for PCM immunotherapy.
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The aim of this study was to investigate the dose-dependent effects of triiodothyronine (T3) on the osteogenic differentiation of mesenchymal stem cells(MSCs). MSCs that express CD73, CD54 (intercellular adhesion molecule-1) and CD90 were... more
The aim of this study was to investigate the dose-dependent effects of triiodothyronine (T3) on the osteogenic differentiation of mesenchymal stem cells(MSCs). MSCs that express CD73, CD54 (intercellular adhesion molecule-1) and CD90 were cultured in triplicate (1 x 10(5)/well) in osteogenic medium with T3 (1, 10, 10(3) or 10(5) pM) or without T3 (control) for 7, 14 and 21 days. Alkaline phosphatase activity, conversion of MTT into formazan crystals, collagen synthesis, collagen maturation, the number of mineralized nodules and their diameters were all determined, and the means were compared by the Student-Newman-Keuls test. A dose of 10(5) pM T3 resulted in a negative effect on MSC osteogenic differentiation, with less collagen synthesis. The 1 pM T3 dose resulted in greater collagen synthesis and alkaline phosphatase activity and more mineralized nodules than in the control group, similar to the 10 pM dose. Nevertheless, the 10 pM dose demonstrated better results than the 1 pM dose with regard to MSC osteogenic differentiation, with greater MTT reduction, better collagen maturation and a larger mean diameter of mineralized nodules. The effect of T3 on MSC differentiation is dose-dependent, with the 10 pM dose promoting better bone marrow MSC osteogenic differentiation.
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Mitotic index, nuclear diameter, number of nucleolar organizing regions, and Ki-67 expression, in hair follicle tumors of 82 dogs were evaluated. Tissue specimens were used to prepare sections for histological staining for number of... more
Mitotic index, nuclear diameter, number of nucleolar organizing regions, and Ki-67 expression, in hair follicle tumors of 82 dogs were evaluated. Tissue specimens were used to prepare sections for histological staining for number of nucleolar organizing region and immunohistochemical staining for Ki-67. Tumors were classified as trichoblastoma (n=32), benign trichoepithelioma (n=30), pilomatricoma (n=7), malignant trichoepithelioma (n=6), infundibular keratinizing acanthoma (n=5), and tricholemmoma (n=2). Head, dorsum, and limbs were the most affected sites. Malignant trichoepithelioma presented significantly higher mitotic index, number of nucleolar organizing regions and Ki-67 expression. Regarding benign neoplasms, trichoblastoma presented significantly higher mitotic index and number of nucleolar organizing regions. Ki-67 expression did not differ among hair follicle benign neoplasms. Recurrence was only observed in two cases, with one benign trichoepithelioma and one malignant trichoepithelioma. In the two cases, nodules have not been removed with clean surgical margin. It was concluded that in benign neoplasms of hair follicles, the number of nucleolar organizing regions and Ki-67 expression were significantly smaller than in malignant neoplasm. Clean surgical margins are suggested to be more responsible to tumor recurrences than the number of nucleolar organizing regions, expression of Ki-67, and the mitotic index.
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The effect of intra-bone injection of differentiated rat bone marrow mesenchymal stem cells (BMMSCs) into the femur of osteoporotic female rats was studied. Osteoporosis was induced in Wistar female rats by bilateral ovariectomy. Then,... more
The effect of intra-bone injection of differentiated rat bone marrow mesenchymal stem cells (BMMSCs) into the femur of osteoporotic female rats was studied. Osteoporosis was induced in Wistar female rats by bilateral ovariectomy. Then, 0.75 million BMMSCs isolated from healthy rats were injected into the femurs of osteoporotic rats. Histomorphometric analysis and histology clearly revealed improvements in the treated group as compared to untreated group. In 2 months, the femurs of treated rats, unlike untreated rats, showed trabecular bone percentage almost similar to the femurs from control healthy rats. To confirm the origin of newly formed bone, the experiment was repeated with BMMSCs isolated from green fluorescent protein transgenic rats. Confocal microscopy demonstrated green fluorescent protein-positive cells at the surface of trabecular bone of the treated rats. We investigated in vitro osteogenic differentiation of BMMSCs isolated from osteoporotic rats by studying alkaline phosphatase activity, collagen synthesis, and the ability to form mineralized nodules. Osteoporotic BMMSCs showed less differentiation capabilities as compared to those isolated from healthy rats. The results clearly demonstrated the importance of BMMSCs in osteoporosis and that the disease can be treated by injection of BMMSCs.