Navegando por Assunto "Fagocitose"

Agora exibindo 1 - 2 de 2

Acesso aberto (Open Access)
Análise da interação in vitro entre Fonsecaea pedrosoi e macrofagos peritoneais de camundongos C57/BL6 e BALB/c
(Universidade Federal do Pará, 2008-04-02) YAMANO, Suellen Sirleide Pereira; SALGADO, Claudio Guedes; http://lattes.cnpq.br/2310734509396125
Chromoblastomycosis (CBM) is a chronic, subcutaneous, granulomatous infection caused by traumatic implantation in the skin of several dematiaceous fungi, usually Fonsecaea pedrosoi. Brazil has second highest disease prevalence in the world and Para State is the most endemic area. Histologically, CBM is characterized by the presence of multinucleated giant cells and sclerotic cells can be found engulfed by macrophages. The objective of this study was to analyze the different aspects of interaction between peritoneal macrophages from BALB/c or C57/BL6 mice with F. pedrosoi conidia or sclerotic cells, calculating infection, phagocytosis and cellular fusion rates. The results showed phagocytosis and infection rates with conidia higher than sclerotic cells to BALB/c (p <0.05), while the rate of cellular fusion was higher for sclerotic cells interaction, with Langhans giant cells formation, in comparison to foreign-body giant cells after interaction with conidia. Macrophages from BALB/c co-cultured with conidia produced more TNF-α than control group after 3 to 72 hours, and more IL-10 after 3h. Macrophages interacting with sclerotic cells produced more TNF-α than control group after 1h and 3h, and the amount of IL-10 was higher after 72h of interaction. In the co-culture of C57/BL6 macrophages with conidia, the presence of large vacuoles after 24h was observed, while in the coculture with sclerotic cells, macrophages were detached from coverslip glasses after 24 h. Our results indicate higher levels of TNF-α after interaction of conidia compared to controls at 1 and 72 h and increase of IL-10 after 48h. However, after interaction with sclerotic cells, only IL-10 differed from control, being higher after 1 to 48 hours. All of these data suggest that macrophage response to fungus is different between BALB/c and C57/BL6 mice, differing also on the response of the same type macrophage for each fungal form, sclerotic cells apparently being more immunogenic than conidia.
Acesso aberto (Open Access)
Avaliação funcional de neutrófilos circulantes em portadores de leucemia mielóide crônica antes e após o início do tratamento com mesilato de imatinibe
(Universidade Federal do Pará, 2019-07-02) DAMASCENO, David Wendell Isacksson; RIBEIRO, Carolina Heitmann Mares Azevedo; http://lattes.cnpq.br/3848996822163999; https://orcid.org/ 0000-0002-9457-2733
Objective: To evaluate neutrophil function in patients with chronic myeloid leukemia (CML) before and after initiation of treatment with imatinib mesylate (MI). Material and Methods: The study included 13 patients diagnosed with CML (new cases), with a mean age of 51 years, of both sexes, selected at the hematology outpatient clinic of the Ophir Loyola Hospital, Belém-PA. In this group three blood samples were taken. The first collection at the time of diagnosis with the untreated patient (Group B1), the second collection after one month of IM treatment (Group B2) and the third collection after four months of treatment (Group B3). The control group (Group A) consisted of 13 healthy volunteers of both sexes. In addition to the blood count and leukogram, the phagocytosis assays and the cytochemical test for spontaneous reduction of nitroazul tetrazolium (NBT) were also performed to evaluate the neutrophil oxidative metabolism. Results: The evaluation of phagocytic function indicated statistical difference when compared Group A with Groups B1, B2 and B3, p = 0.0001. Groups B1, B2 and B3 presented lower phagocytic indices (IFs) with 2.07 ± 0.5; 1.99 ± 0.4 and 1.97 ± 0.6 respectively, compared to Group A with 3.72 ± 0.8. In the oxidative metabolism evaluation there was no statistical difference between group A with groups B1, B2 and B3, p = 0.2997. Discussion: The results showed that untreated patients had lower IF compared to the control group. This means that even if the patient has innumerable cells of the proliferative process, these cells have their functions diminished. Patients treated with MI also had lower IF compared to the control group. Although the number of leukocytes and neutrophils decreased in these patients, the phagocytic capacity of these cells remained decreased. There was no statistical difference regarding the activation of oxidative metabolism in the NBT reduction test. This means that the production of ROS by the NADPH oxidase system does not change independently of MI treatment. Conclusion: There was a reduction in the amount of circulating neutrophils after initiation of IM treatment. The phagocytic function of neutrophils remained decreased after initiation of IM treatment. Neutrophil oxidative metabolism does not change independently of MI treatment. Therefore, additional studies are important to evaluate the exact mechanism of function alteration involved in these patients to allow a better orientation regarding the therapy used.