VALDIR SABBAGA AMATO
Projetos de Pesquisa
Unidades Organizacionais
Departamento de Moléstias Infecciosas e Parasitárias, Faculdade de Medicina - Docente
LIM/46 - Laboratório de Parasitologia Médica, Hospital das Clínicas, Faculdade de Medicina - Líder
LIM/46 - Laboratório de Parasitologia Médica, Hospital das Clínicas, Faculdade de Medicina - Líder
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bookPart Leishmaniose tegumentar(2013) AMATO, Valdir Sabbaga; CAMARGO, Raphael Abegão de; TUON, Felipe Francisco- Comparative study on liposomal amphotericin B and other therapies in the treatment of mucosal leishmaniasis: A 15-year retrospective cohort study(2019) SANTOS, Carolina Rocio; TUON, Felipe Francisco; CIESLINSKI, Juliette; SOUZA, Regina Maia de; IMAMURA, Rui; AMATO, Valdir SabbagaBackground Liposomal amphotericin B (L-AMB) has been used for mucosal leishmaniasis (ML), but comparative studies on L-AMB and other drugs used for the treatment of ML have not been conducted. The present study aimed to evaluate the outcome of patients with ML who were treated with L-AMB. Methods This is a 15-year retrospective study of Brazilian patients with a confirmed diagnosis of ML. The therapeutic options for the treatment of ML consisted of L-AMB, amphotericin B lipid complex (ABLC), deoxycholate amphotericin B (d-AMB), itraconazole, antimonial pentavalent, or pentamidine. Healing, cure rate and adverse effects (AEs) associated with the drugs used to treat this condition were analyzed. Results In 71 patients, a total of 105 treatments were evaluated. The outcome of the treatment with each drug was compared, and results showed that L-AMB was superior to other therapeutic regimens (P = 0.001; odds ratio [OR] = 4.84; 95% confidence interval [CI] = 1.78-13.17). d-AMB had worse AEs than other treatment regimens (P = 0.001, OR = 0.09; 95% CI = 0.09-0.43). Approximately 66% of the patients presented with AEs during ML treatment. Although L-AMB was less nephrotoxic than d-AMB, it was associated with acute kidney injury compared with other drugs (P <0.05). Conclusion L-AMB was more effective than other therapies for the treatment of ML. However, a high incidence of toxicity was associated with its use. Therapeutic choices should be reassessed, and the development of new drugs is necessary for the treatment of ML.
- Liposomal drug delivery systems for the treatment of leishmaniasis(2022) TUON, Felipe Francisco; DANTAS, Leticia Ramos; SOUZA, Regina Maia de; RIBEIRO, Victoria Stadler Tasca; AMATO, Valdir SabbagaHuman leishmaniasis is a vector-borne, neglected infectious disease that is widely distributed in America, Africa, Europe, and Asia. Current therapy is based on old and toxic drugs, including antimonials, aminoglycosides, and amphotericin. As a neglected disease, investment in the development of new therapeutic molecules is scarce. Considering these aspects, the optimization of treatment through novel delivery systems for current therapeutic agents is an attractive alternative. The encapsulation into liposomes of drugs used in treating leishmaniasis increases the concentration of these molecules in macrophages, which may not only increase the chance of cure but also expand their therapeutic spectrum to include resistant Leishmania, as well as reducing toxicity since the drug is less exposed to healthy cells. The classical example is the liposomal formulation of amphotericin B, a well-established therapeutic option that uses liposomes to decrease the progression of renal failure in patients. However, loading other leishmanicidal drugs into liposomes, such as pentavalent antimonials, presents an opportunity for innovative and cheaper therapeutic options for the treatment of human leishmaniasis. This review aims to discuss liposomes as a drug delivery system for leishmanicidal drugs.
- Hydrogel membranes of PVA1/clay by gamma radiation(2013) OLIVEIRA, M. J. A. de; PARRA, D. F.; AMATO, V. S.; LUGAO, A. B.In the last decades several studies concerning the new methods for drug delivery system have been investigated. A new field known as ""smart therapy"" involves devices and drug delivery systems to detect, identify and treat the site affected by the disease, not interfering with the biological system. Cutaneous Leishmaniasis is an endemic disease that is characterized by the development of single or multiple localized lesions on exposed areas of skin and one coetaneous treatment could be a potential solution. The aim of this study was to obtain polymeric hydrogel matrices of poly(vinylalcohol)(PVAI) and chitosan with inorganic nanoparticles, which can release a drug according to the need of the treatment of injury caused by leishmania on the skin. The hydrogels matrices were obtained with PVAI/ chitosan and PVAI/ chitosan 0.5; 1.0 and 1.5% laponite RD clay, crosslinked by ionizing gamma radiation with dose of 25 kGy. The techniques used for characterization were swelling, gel fraction, Fourier transform infrared spectroscopy (FTIR) and thermogravimetry (TGA). After synthesis, the samples were immersed in distilled water and weighed in periods of time until 60 h for the swelling determination. The obtained results have indicated that the swelling of the membranes increases with clay concentration, in consequence of ionic groups present in the clay.
- Case Report: Reactivation of Mucosal and Cutaneous Leishmaniasis in a Renal Transplanted Patient(2014) TUON, Felipe F.; BOMBONATTO, Giovana Marina; BATTAGLIN, Eveline Roesler; SAKUMOTO, Marcus Henrique; AMATO, Valdir Sabbaga; CAMARGO, Raphael Abegao de; NICODEMO, Antonio CarlosMucosal leishmaniasis (ML) is a chronic form of tegumentary leishmaniasis, which causes destructive lesions of nasal, pharyngeal, and laryngeal mucosa. We describe a case of leishmaniasis reactivation with simultaneous cutaneous and mucosal forms in a renal transplanted patient with no history of prior leishmaniasis. Reactivation after renal transplantation was not reported in Brazil. A 67-year-old woman receiving prednisone 20 mg/day, tacrolimus 1 mg/day, and mycophenolic acid 360 mg/day presented with nose edema with erythema and cutaneous lesions. Amastigotes were identified on biopsies and the polymerase chain reaction confirmed Leishmania (Viannia) braziliensis. The patient was treated with liposomal amphotericin B but died 3 weeks after as a result of bacterial septic shock. In conclusion, tegumentary leishmaniasis can reactivate with simultaneous cutaneous and mucosal forms in a renal transplanted patient during the immunosuppressant therapy.
- Facial Structure Alterations and Abnormalities of the Paranasal Sinuses on Multidetector Computed Tomography Scans of Patients with Treated Mucosal Leishmaniasis(2014) CAMARGO, Raphael Abegao de; NICODEMO, Antonio C.; SUMI, Daniel Vaccaro; GEBRIM, Eloisa Maria Mello Santiago; TUON, Felipe Francisco; CAMARGO, Lazaro Manoel de; IMAMURA, Rui; AMATO, Valdir SabbagaBackground/Objectives: Mucosal leishmaniasis (ML) is a progressive disease that affects cartilage and bone structures of the nose and other upper respiratory tract structures. Complications associated with ML have been described, but there is a lack of studies that evaluate the structural changes of the nose and paranasal sinuses in ML using radiological methods. In this study, we aimed to assess the opacification of the paranasal sinuses in patients with treated ML and any anatomical changes in the face associated with ML using multidetector computed tomography scans (MDCT) of the sinuses. We compared the findings with a control group. Methodology/Principal Findings: We evaluated 54 patients with treated ML who underwent CT scans of the sinuses and compared them with a control group of 40 patients who underwent orbital CT scans. The degree of sinus disease was assessed according to the Lund-Mackay criteria. Forty of the 54 patients with a history of ML (74.1%) had a tomographic score compatible with chronic sinusitis (Lund-Mackay >= 4). CT scans in the leishmaniasis and control groups demonstrated significant differences in terms of facial structure alterations. Patients from the ML group showed more severe levels of partial opacification and pansinus mucosal thickening (42.6%) and a greater severity of total opacification. Patients from the ML group with a Lund-Mackay score >= 4 presented longer durations of disease before treatment and more severe presentations of the disease at diagnosis. Conclusion/Significance: CT scans of the sinuses of patients with ML presented several structural alterations, revealing a prominent destructive feature of the disease. The higher prevalence in this study of chronic rhinosinusitis observed in CT scans of patients with treated ML than in those of the control group suggests that ML can be considered a risk factor for chronic rhinosinusitis in this population (p<0.05).
- Twenty years of successful academic outreach at Nucleo de Medicina Tropical (NACE-NUMETROP/USP) in Santarem, Para(2021) SAID, Renato do Carmo; ASSY, Joao Guilherme Pontes Lima; SILVA, Kamila Vieira; BRANDAO, Alisson dos Santos; PINHEIRO, Olivia Campos; ESPER, Helena Rangel; GRYSCHEK, Anna Luiza de Fatima Pinho Lins; BERTOLOZZI, Maria Rita; AMATO, Valdir Sabbaga; BOULOS, Marcos; SEGURADO, Aluisio Augusto Cotrim; GRYSCHEK, Ronaldo Cesar Borges; FRANCA, Francisco Oscar de Siqueira
- Tegumentary leishmaniasis mimicking visceralization in a cirrhotic patient: atypical cutaneous lesions and local immunological features(2020) VERNAL, Sebastian; CASAL, Yuri; VIEIRA, Lucas T.; AMATO, Valdir S.; DUARTE, Maria Irma S.; NASTRI, Ana Catharina S. S.Tegumentary leislunaniasis (TL) diagnosis is challenging due to the lack of a gold standard diagnostic tool. The diagnosis is significantly harder in regions where visceral leishmaniasis (VL) is also prevalent since immunological tests may present cross-reactivity. A cirrhotic patient from an endemic Brazilian region for TL and VL presented with atypical cutaneous lesions, a usual clinico-laboratory feature of VL (including a positive rk39 test result), but he was diagnosed with TL histopathologically; VL was ruled out by necropsy. Physicians working in co-prevalent areas should be aware of atypical features, unusual clinical course, and unexpected laboratory findings of leishmaniasis.
- Emerging computational technologies in human leishmaniasis: where are we?(2022) TUON, Felipe Francisco; AMATO, Valdir Sabagga; ZEQUINAO, Tiago; CRUZ, June Alisson WestarbHuman leishmaniasis is a neglected tropical disease (NTD) with high morbidity and is endemic in low- to middle-income countries. Its diagnosis, treatment and epidemiological control methods are outdated and obsolete, which has become a challenge for health practitioners in controlling the disease. Computational methods have proven to be beneficial and have become popular in many fields of medicine, especially in affluent countries. However, they have not been widely used for NTDs. To date, few computational technologies have been employed for leishmaniasis. Although new technologies in leishmaniasis are theorized, they have only been minimally applied and have not been updated, even in other infections. Research and development on NTDs suffers from the inherent difficulties of the demographic regions the diseases afflict. In this narrative review we described the e-tools available in managing leishmaniasis, ranging from drug discovery to treatment.
- Identification of Leishmania species by next generation sequencing of hsp70 gene(2022) SOUZA, Regina Maia de; MARTINS, Roberta Cristina Ruedas; FRANCO, Lucas Augusto Moyses; TUON, Felipe Francisco; OLIVEIRA JUNIOR, Isael Gomes de; SILVA, Camila Alves Maia da; IMAMURA, Rui; AMATO, Valdir SabbagaLeishmaniasis is a major public health problem worldwide. Although next generation sequencing technology has been widely used in the diagnosis of infectious diseases, it has been scarcely applied in identification of Leishmania species. The aim of this study was to compare the efficiency of MinIONTM nanopore sequencing and polymerase chain reaction restriction fragment length polymorphism in identifying Leishmania species. Our results showed that the MinIONTM sequencer was able to discriminate reference strains and clinical samples with high sensitivity in a cost and time effective manner without the prior need for culture.