Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Leishmania are obligate intracellular parasites of mononuclear phagocytes transmitted by Phlebotomine sandflies. Monocytes are one of the main cell types recruited to the site of the bite having an important role in the defense against... more
Leishmania are obligate intracellular parasites of mononuclear phagocytes transmitted by Phlebotomine sandflies. Monocytes are one of the main cell types recruited to the site of the bite having an important role in the defense against Leishmania parasites in the first hours of infection. In the tissue, macrophages play a pivotal role as both the primary replication sites and the major effector cells responsible for parasite elimination. Many authors have reviewed the monocyte/macrophage-Leishmania interactions from results derived in mice, however, given the important differences between mice an humans we considered vital to discuss the role of these cells in human leishmaniasis. In this review, we recapitulated the most important studies carried out to understand the different roles of human monocyte/macrophages in Leishmania infection and how they can participate in both control and the immunopathogenesis of the disease.
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Leishmania parasites were isolated from four of seven small rodent species captured in the State of Campeche, Mexico. Signs and/or symptoms of leishmanial infection were restricted to the tail of the mice. Peromyscus yucatanicus endemic... more
Leishmania parasites were isolated from four of seven small rodent species captured in the State of Campeche, Mexico. Signs and/or symptoms of leishmanial infection were restricted to the tail of the mice. Peromyscus yucatanicus endemic to the peninsula of Yucatan and Oryzomys melanotis were added to the list of carriers of Leishmania. Leishmania (L.) mexicana, characterized by an indirect immunofluorescence antibody method using monoclonal antibodies, was identified in one Sigmodon hispidus and one Or. melanotis. The possible role of the different species as primary reservoirs of Leishmania in the peninsula of Yucatan is discussed.
Research Interests:
Research Interests:
Research Interests:
Research Interests: Immunology, Biology, Medicine, Sequence alignment, Female, and 13 moreAnimals, Male, Cytokine, Molecular cloning, Tumor necrosis factor-alpha, Transforming Growth Factor Beta, Peromyscus, Cutaneous Leishmaniasis, Amino Acid Sequence, Base Sequence, Interleukin, Interferon gamma, and Molecular Sequence Data
Research Interests: Biology, Histology, Leishmania, Medicine, Rodentia, and 9 moreBiopsy, Leishmaniasis, Female, Animals, Male, Time Factors, Inoculation, Lesion, and Cutaneous Leishmaniasis
Research Interests:
Research Interests: Entomology, Philosophy, Applied Ethics, Politics, Developing Countries, and 15 moreLeishmania, Medicine, Mexico, Leishmaniasis, Humans, Developing Country, Developing World, Field Study, Occupational Exposure, Ethical Issues, Cutaneous Leishmaniasis, MEXICO, Ethics Research, Occupational Diseases, and guidelines as topic
Cytokine expression in the delayed-type hypersensitivity response of Peromyscus yucatanicus infected by Leishmania (Leishmania) mexicana that healed spontaneously / Expressão de citocinas na resposta de hipersensibilidade de tipo retardado de Peromyscus yucatanicus infectado por Leishmania (Leishmanmore
Peromyscus yucatanicus tem sido empregado como modelo para estudar a leishmaniose tegumentar causada por Leishmania (Leishmania) mexicana. No entanto, não há informações sobre a cura espontânea e a resposta imune associada nesses... more
Peromyscus yucatanicus tem sido empregado como modelo para estudar a leishmaniose tegumentar causada por Leishmania (Leishmania) mexicana. No entanto, não há informações sobre a cura espontânea e a resposta imune associada nesses roedores. O objetivo deste trabalho foi analisar a expressão de citocinas na resposta de hipersensibilidade do tipo retardado de Peromyscus yucatanicus infectado por Leishmania (Leishmania) mexicana que cicatrizou espontaneamente. Peromyscus yucatanicus (n = 40) foram inoculados com 2.5 × 106 parasitas na cauda e a evolução foi registrada semanalmente até o aparecimento das lesões ativas (Grupo I: não cicatrizadas) e até a cicatrização espontânea (Grupo II: cicatrizadas). Um grupo controle foi injetado com meio RPMI-1640. A resposta de hipersensibilidade do tipo retardado (DTH) e as expressões de citocinas (IFN-γ, IL-10, TNF) foram determinadas. A cura espontânea foi observada em 65% (13/20) dos P. yucatanicus do Grupo II. O grupo curado desenvolveu uma for...
Research Interests: Biology and Peromyscus
Localized Cutaneous Leishmaniasis (LCL) known as "chiclero's ulcer" in southeast Mexico, was described by SEIDELIN in 1912. Since then the sylvatic region of the Yucatan peninsula has been documented as an endemic focus of... more
Localized Cutaneous Leishmaniasis (LCL) known as "chiclero's ulcer" in southeast Mexico, was described by SEIDELIN in 1912. Since then the sylvatic region of the Yucatan peninsula has been documented as an endemic focus of LCL. This study of 73 biopsies from parasitological confirmed lesions of LCL cases of Leishmania (Leishmania) mexicana infection was undertaken: 1) to examine host response at tissue level; and 2) to relate manifestations of this response to some characteristics of clinical presentation. Based on Magalhães' classification we found that the most common pattern in our LCL cases caused by L. (L.) mexicana was predominantly characterized by the presence of unorganized granuloma without necrosis, (43.8%). Another important finding to be highlighted is the fact that in 50/73 (68.5%) parasite identification was positive. There was direct relation between the size of the lesion and time of evolution (r s = 0.3079, p = 0.03), and inverse correlation betwe...
Research Interests:
Research Interests:
In IDL-1097
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Research Interests:
Sandflies attracted by human bait were caught in an endemic focus of localized cutaneous leishmaniasis in the state of Campeche, Mexico. Catches were carried out monthly from February 1994 to January 1995 between 18:00 and 22:00 h.... more
Sandflies attracted by human bait were caught in an endemic focus of localized cutaneous leishmaniasis in the state of Campeche, Mexico. Catches were carried out monthly from February 1994 to January 1995 between 18:00 and 22:00 h. Lutzomyia cruciata was the only species caught. The highest population peak of Lu. cruciata was found in March with lesser peaks in February, December 1994, and January 1995. Maximum biting rate of Lu. cruciata was found between 18:00 and 19:00 h. The host-seeking females of Lu. cruciata were directly related to levels of humidity between 88 and 100%. Low and high temperature had a negative effect upon Lu. cruciata activity. The possible role of Lu. cruciata as vector of leishmaniasis in the state of Campeche, Mexico is discussed.
Research Interests:
SUMMARY Transforming growth factor (TGF)-β1 is expressed abundantly in the rheumatoid synovium. In this study, the inflammatory effect of TGF-β1 in rheumatoid arthritis (RA) was investigated using cultured fibroblast-like synoviocytes... more
SUMMARY Transforming growth factor (TGF)-β1 is expressed abundantly in the rheumatoid synovium. In this study, the inflammatory effect of TGF-β1 in rheumatoid arthritis (RA) was investigated using cultured fibroblast-like synoviocytes (FLS) from RA and osteoarthritis (OA) patients, as well as non-arthritic individuals. mRNA expressions of IL-1β, tumour necrosis factor (TNF)-α, IL-8, macrophage inflammatory protein (MIP)-1α and metalloproteinase (MMP)-1 were increased in RA and OA FLS by TGF-β1 treatment, but not in non-arthritic FLS. Enhanced protein expression of IL-1β, IL-8 and MMP-1 was also observed in RA FLS. Moreover, TGF-β1 showed a synergistic effect in increasing protein expression of IL-1β and matrix metalloproteinase (MMP)-1 with TNFα and IL-1β, respectively. Biological activity of IL-1 determined by mouse thymocyte proliferation assay was also enhanced by 50% in response to TGF-β1 in the culture supernatant of RA FLS. DNA binding activities of nuclear factor (NF)-κB and ...
Research Interests:
Research Interests:
Abstract. Cutaneous leishmaniasis, known as chiclero’s ulcer in southeastern Mexico, is characterized by a pre-dominantly single, painless, ulcerated lesion, without lymphangitis or adenopathy. When located on the ear, it tends to become... more
Abstract. Cutaneous leishmaniasis, known as chiclero’s ulcer in southeastern Mexico, is characterized by a pre-dominantly single, painless, ulcerated lesion, without lymphangitis or adenopathy. When located on the ear, it tends to become chronic, causing destruction of the pinna and disfigurement. It is caused predominantly by Leishmania (L.) mexicana. Although pentavalent antimonials (Sb51) are the mainstay of leishmanial therapy and have been used for more than 50 years, dosage regimens have been repeatedly modified and the best one has not been fully identified. The main purpose of the present study was to investigate the response of chiclero’s ulcer to treatment with meglumine antimoniate. One hundred five patients were treated with meglumine antimoniate at a daily dose of 1 ampule per day (425 mg of Sb51) until healing. The lesions healed after a mean of 25 days (range 5 5–60 days). Cutaneous leishmaniasis (CL), known as chiclero’s ulcer in southeast Mexico, was accurately desc...
Research Interests:
American cutaneous leishmaniasis (ACL) is a major public health problem caused by vector-borne protozoan intracellular parasites from the genus
Research Interests:
The nature of the host cellular immune response largely determines the expression of disease following infection with the intracellular protozoans Leishmania spp. In experimental animals control and resolution of infection are mediated by... more
The nature of the host cellular immune response largely determines the expression of disease following infection with the intracellular protozoans Leishmania spp. In experimental animals control and resolution of infection are mediated by gamma interferon and tumor necrosis factor alpha (TNF-a), whereas disease progression is associated with the production of interleukin 4 (II-4), IL-5, IL-10, and transforming growth factor beta (TGF-13). We have analyzed the profile of cytokine gene expression directly in the lesions of 13 patients with localized cutaneous leishmaniasis due to Leishmania mexicana. All but one patient had a single lesion, and the time of evolution ranged from 8 days to 18 months. Cytokine gene expression was quantitated by reverse transcriptase PCR and interpolation from a standard curve. Gamma interferon, TNF-a, IL-la, IL-6,
Research Interests:
La investigación para la salud es esencial para enfrentar los retos actuales y futuros mediante la generación de nuevos conocimientos, que a su vez deben ser traducidos en mejores formas de prevenir y tratar las enfermedades, todo con... more
La investigación para la salud es esencial para enfrentar los retos actuales y futuros mediante la generación de nuevos conocimientos, que a su vez deben ser traducidos en mejores formas de prevenir y tratar las enfermedades, todo con el fin de lograr un desarrollo humano global sostenible. La tan necesaria investigación colaborativa Norte-Sur para la salud ha ido en franco aumento en las últimas décadas como respuesta a lo anterior. Por diversas razones, en esta interacción han surgido desafíos y cuestionamientos bioéticos que deben ser afrontados. En el presente trabajo se identifican 1) la asimetría; 2) el colonialismo; 3) la explotación; 4) la información, y 5) los comités de ética en investigación como los principales desafíos y se revisan los aspectos bioéticos que son necesarios atender. Resulta evidente la urgencia de construir una bioética de la investigación para la salud en colaboración entre países del Norte y países del Sur.
Research Interests:
Leishmania parasites were isolated from four of seven small rodent species captured in the State of Campeche, Mexico. Signs and/or symptoms of leishmanial infection were restricted to the tail of the mice. Peromyscus yucatanicus endemic... more
Leishmania parasites were isolated from four of seven small rodent species captured in the State of Campeche, Mexico. Signs and/or symptoms of leishmanial infection were restricted to the tail of the mice. Peromyscus yucatanicus endemic to the peninsula of Yucatan and Oryzomys melanotis were added to the list of carriers of Leishmania. Leishmania (L.) mexicana, characterized by an indirect immunofluorescence antibody method using monoclonal antibodies, was identified in one Sigmodon hispidus and one Or. melanotis. The possible role of the different species as primary reservoirs of Leishmania in the peninsula of Yucatan is discussed.
Research Interests:
Research Interests: Immunology, NO, Sequence alignment, Female, Animals, and 15 moreMale, TNF, Cytokine, Molecular cloning, mRNA, Tumor necrosis factor-alpha, cDNA, Transforming Growth Factor Beta, Peromyscus, Cutaneous Leishmaniasis, Amino Acid Sequence, Base Sequence, Interleukin, Interferon gamma, and Molecular Sequence Data
Base de dados : LILACS. Pesquisa : 248126 [Identificador único]. Referências encontradas : 1 [refinar]. Mostrando: 1 .. 1 no formato [Detalhado]. página 1 de 1, 1 / 1, LILACS, seleciona. para imprimir. Fotocópia. experimental, Documentos... more
Base de dados : LILACS. Pesquisa : 248126 [Identificador único]. Referências encontradas : 1 [refinar]. Mostrando: 1 .. 1 no formato [Detalhado]. página 1 de 1, 1 / 1, LILACS, seleciona. para imprimir. Fotocópia. experimental, Documentos relacionados. Id: 248126. ...
Crucial to the defense against Leishmania is the ability of the host to mount a cell-mediated immune response capable of controlling and/or eliminating the parasite. The composition of the cell populations recruited in the early phase of... more
Crucial to the defense against Leishmania is the ability of the host to mount a cell-mediated immune response capable of controlling and/or eliminating the parasite. The composition of the cell populations recruited in the early phase of the infection seems to be essential for defining the infection outcomes. The signals that initiate and regulate the early immune response and local accumulation of cell subsets in the skin are poorly understood. We previously studied the in situ expression of cytokine genes in patients with localized cutaneous leishmaniasis (LCL) caused by Leishmania (Leishmania) mexicana. In the present study we examined in situ cytokine (IL-4, IL-10, IL-12, IFN-γ) and chemokine (MCP-1, MIP-1α) gene expression in L. (L.) mexicana active LCL lesions, and in the delayed type hypersensitivity (DTH) skin response to Leishmania antigen in subjects with healed lesion and subclinical infection. Data regarding cytokines were similar to previous studies in patients with active LCL. There were no significant differences in the profile of cytokine and chemokine gene expression in DTH from subjects with healed or subclinical infection. IL-12 gene expression detected in both groups was similar. High expression of MCP-1 was detected in all patients with active LCL. There was no difference in the level of MCP-1 expression between the healed lesion and the subclinical infection groups (p = 0.876). IL-12 and MCP-1 in the absence of IFN-γ might be playing a crucial role in infection outcomes at skin level.
Research Interests:
The nature of the host cellular immune response largely determines the expression of disease following infection with the intracellular protozoans Leishmania spp. In experimental animals control and resolution of infection are mediated by... more
The nature of the host cellular immune response largely determines the expression of disease following infection with the intracellular protozoans Leishmania spp. In experimental animals control and resolution of infection are mediated by gamma interferon and tumor necrosis factor alpha (TNF-alpha), whereas disease progression is associated with the production of interleukin 4 (IL-4), IL-5, IL-10, and transforming growth factor beta (TGF-beta). We have analyzed the profile of cytokine gene expression directly in the lesions of 13 patients with localized cutaneous leishmaniasis due to Leishmania mexicana. All but one patient had a single lesion, and the time of evolution ranged from 8 days to 18 months. Cytokine gene expression was quantitated by reverse transcriptase PCR and interpolation from a standard curve. Gamma interferon, TNF-alpha, IL-1 alpha, IL-6, IL-10, and TGF-beta gene expression was present in all samples. IL-3 and IL-4 gene expression was barely detectable in 1 and 3 ...
Research Interests:
Immunity in leishmaniasis is mediated by T cells, but protective responses in humans have not been fully defined. In this study, the functional activity of CD4+ T cell clones derived from an immune individual was investigated to identify... more
Immunity in leishmaniasis is mediated by T cells, but protective responses in humans have not been fully defined. In this study, the functional activity of CD4+ T cell clones derived from an immune individual was investigated to identify potentially protective responses. The T cells proliferated and produced interferon-gamma (IFN-gamma) in response to a soluble Leishmania donovani antigen extract and live amastigotes. There was considerable variation in the anti-leishmanial activity of the T cell clones when they were co-cultured with L. donovani infected monocytes isolated from an HLA-DR,DQ matched donor. All of the clones which demonstrated antigen specific reactivity by proliferation or cytokine production induced some degree of inhibition of intracellular parasite replication, but only a few of the clones induced pronounced leishmanicidal activity. There was strong correlation between the level of amastigote-induced IFN-gamma secretion and anti-leishmanial activity. This approac...
Research Interests:
Cutaneous leishmaniasis, known as chiclero's ulcer in southeastern Mexico, is characterized by a predominantly single, painless, ulcerated lesion, without lymphangitis or adenopathy. When located on the ear, it tends to become... more
Cutaneous leishmaniasis, known as chiclero's ulcer in southeastern Mexico, is characterized by a predominantly single, painless, ulcerated lesion, without lymphangitis or adenopathy. When located on the ear, it tends to become chronic, causing destruction of the pinna and disfigurement. It is caused predominantly by Leishmania (L.) mexicana. Although pentavalent antimonials (Sb5+) are the mainstay of leishmanial therapy and have been used for more than 50 years, dosage regimens have been repeatedly modified and the best one has not been fully identified. The main purpose of the present study was to investigate the response of chiclero's ulcer to treatment with meglumine antimoniate. One hundred five patients were treated with meglumine antimoniate at a daily dose of 1 ampule per day (425 mg of Sb5+) until healing. The lesions healed after a mean of 25 days (range = 5-60 days).
Research Interests:
The state of Tabasco is localized in the endemic area of cutaneous leishmaniasis where both diffuse cutaneous leishmaniasis and mucocutaneous leishmaniasis have recently been reported. The objective of the present study was to obtain... more
The state of Tabasco is localized in the endemic area of cutaneous leishmaniasis where both diffuse cutaneous leishmaniasis and mucocutaneous leishmaniasis have recently been reported. The objective of the present study was to obtain reliable information of the situation of this disease--which has a great relevance as a worldwide public health problem--through determination of the allergic index in a randomized sample from Ranchería Miguel Hidalgo, Comalcalco Municipality, Tabasco, Mexico. We found an allergic index of 56 per cent. Farmers and housewives had the highest positive responses to the Montenegro skin test. We found no statistical differences between males and females. Moreover, 3 patients with active lesions and people with scars suggestive of prior leishmaniasis were detected during the study. This village should be considered a high endemic focus.