RESUMO
In Central America, infection by Leishmania (Leishmania) infantum chagasi causes visceral leishmaniasis and non-ulcerated cutaneous leishmaniasis (NUCL). This work aimed to evaluate the participation of subpopulations of antigen-presenting cells in skin lesions of patients affected by NUCL through double-staining immunohistochemistry using cellular and intracellular markers. Twenty-three skin biopsies from patients affected by NUCL were used. Histological sections stained by HE were used for histopathological study. Immunohistochemical studies were performed using primary antibodies against Langerhans cells, dermal dendritic cells, T lymphocytes, and the cytokines IL-12, IFN-γ, TNF-α, iNOS, and IL-10. The histopathological lesions were characterized by an inflammatory infiltrate, predominantly lymphohistiocytic, of variable intensity, with a diffuse arrangement associated with epithelioid granulomas and discreet parasitism. Double-staining immunohistochemistry showed higher participation of dendritic cells producing the proinflammatory cytokine IL-12 in relation to the other evaluated cytokines. Activation of the cellular immune response was marked by a higher density of CD8 Tc1-lymphocytes followed by CD4 Th1-lymphocytes producing mainly IFN-γ. The data obtained in the present study suggest that antigen-presenting cells play an important role in the in situ immune response through the production of proinflammatory cytokines, directing the cellular immune response preferentially to the Th1 and Tc1 types in NUCL caused by L. (L.) infantum chagasi.
Assuntos
Leishmania infantum , Leishmaniose Cutânea , Leishmaniose Visceral , Humanos , Citocinas , Células Apresentadoras de Antígenos , Interleucina-12RESUMO
In Central America, Leishmania (L.) infantum chagasi infection causes visceral leishmaniasis (VL) and non-ulcerated cutaneous leishmaniasis (NUCL). The aim of the present study was to evaluate the course of an experimental infection in hamsters caused by L. (L.) infantum chagasi isolated from patients affected by NUCL compared with a strain isolated from a patient with VL. Stationary phase parasites in culture were inoculated through subcutaneous and intraperitoneal routes in hamsters. Following the post-infection times, a histopathological study, parasite load and cytokine determination in skin from the cutaneous inoculation site and viscera were performed. Animals subcutaneously infected with the different strains did not develop macroscopic lesions at the inoculation site, and the histopathological changes in the dermis were very slight. Regarding the histopathological study of the viscera, we observed the portal mononuclear inflammatory infiltrate, the presence of nodules in the hepatic parenchyma and the proliferation of macrophages in the spleen, which increased over the infection course. Overall, the parasite load in the liver and spleen and in the total IgG titres in the sera of infected hamster showed an increase with the time of infection, regardless of the route of inoculation. Regarding cellular immunity, we did not observe an increase or decrease in pro- and anti-inflammatory cytokines compared to the healthy control, except for IL-10, which was evident in the infected animals. The data showed that strains isolated from NUCL cause visceral lesions in the hamsters regardless of the route of inoculation, and they were similar to parasites isolated from VL humans.
Assuntos
Leishmania infantum , Leishmaniose Cutânea , Leishmaniose Visceral , Parasitos , Cricetinae , Animais , Humanos , Leishmaniose Cutânea/parasitologia , Leishmaniose Visceral/parasitologia , Pele/parasitologia , CitocinasRESUMO
Macrophages play important roles in the innate and acquired immune responses against Leishmania parasites. Depending on the subset and activation status, macrophages may eliminate intracellular parasites; however, these host cells also can offer a safe environment for Leishmania replication. In this sense, the fate of the parasite may be influenced by the phenotype of the infected macrophage, linked to the subtype of classically activated (M1) or alternatively activated (M2) macrophages. In the present study, M1 and M2 macrophage subsets were analyzed by double-staining immunohistochemistry in skin biopsies from patients with American cutaneous leishmaniasis (ACL) caused by L. (L.) amazonensis, L. (V.) braziliensis, L. (V.) panamensis ,and L. (L.) infantum chagasi. High number of M1 macrophages was detected in nonulcerated cutaneous leishmaniasis (NUCL) caused by L. (L.) infantum chagasi (M1 = 112 ± 12, M2 = 43 ± 12 cells/mm2). On the other side, high density of M2 macrophages was observed in the skin lesions of patients with anergic diffuse cutaneous leishmaniasis (ADCL) (M1 = 195 ± 25, M2 = 616 ± 114), followed by cases of localized cutaneous leishmaniasis (LCL) caused by L. (L.) amazonensis (M1 = 97 ± 24, M2 = 219 ± 29), L. (V.) panamensis (M1 = 71 ± 14, M2 = 164 ± 14), and L. (V.) braziliensis (M1 = 50 ± 13, M2 = 53 ± 10); however, low density of M2 macrophages was observed in NUCL. The data presented herein show the polarization of macrophages in skin lesions caused by different Leishmania species that may be related with the outcome of the disease.
Assuntos
Leishmania/imunologia , Leishmaniose Cutânea/imunologia , Ativação de Macrófagos , Macrófagos/imunologia , Pele/parasitologia , Biópsia , Humanos , Leishmaniose Cutânea/parasitologia , Leishmaniose Cutânea/patologia , Macrófagos/parasitologia , Pele/imunologia , Pele/patologiaRESUMO
The induced expression of nitric oxide synthase (iNOS) controls the intracellular growth of Leishmania in infected macrophages. Histones deacetylases (HDACs) negatively regulate gene expression through the formation of complexes containing transcription factors such as NF-κB p50/50. Herein, we demonstrated the occupancy of p50/p50_HDAC1 to iNOS promoter associated with reduced levels of H3K9Ac. Remarkably, we found increased levels of HDAC1 in L. amazonensis-infected macrophages. HDAC1 upregulation was not found in L. major-infected macrophages. The parasite intracellular load was reduced in HDAC1 knocked-down macrophages, which presented increased nitric oxide levels. HDAC1 silencing led to the occupancy of CBP/p300 to iNOS promoter and the rise of H3K9Ac modification. Importantly, the immunostaining of skin samples from hiporeactive cutaneous leishmaniasis patients infected with L. amazonensis, revealed high levels of HDAC1. In brief, L. amazonensis induces HDAC1 in infected macrophages, which contribute to parasite survival and is associated to hiporeactive stage found in L. amazonensis infected patients.
Assuntos
Histona Desacetilase 1/metabolismo , Leishmania braziliensis/fisiologia , Leishmaniose Cutânea/imunologia , Macrófagos/imunologia , Óxido Nítrico Sintase Tipo II/metabolismo , Pele/patologia , Adolescente , Adulto , Células Cultivadas , Criança , Extinção Biológica , Feminino , Histona Desacetilase 1/genética , Interações Hospedeiro-Parasita , Humanos , Evasão da Resposta Imune , Leishmaniose Cutânea/genética , Masculino , Pessoa de Meia-Idade , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo II/genética , Carga Parasitária , Regiões Promotoras Genéticas/genética , Ligação Proteica , RNA Interferente Pequeno/genética , Fator de Transcrição Sp1/metabolismo , Adulto JovemRESUMO
The current medications used to treat leishmaniasis have many side effects for patients; in addition, some cases of the disease are refractory to treatment. Therefore, the search for new leishmanicidal compounds is indispensable. Recently, it was demonstrated that oleanolic- and ursolic-containing fraction from Baccharis uncinella leaves eliminated the promastigote and amastigote forms of Leishmania (Leishmania) amazonensis and L. (Viannia) braziliensis without causing toxic effects for J774 macrophages. Thus, the aim of the present work was to characterize the therapeutic effect of the triterpenic fraction in L. (L.) amazonensis-infected BALB/c mice. Oleanolic- and ursolic acid-containing fraction was extracted from B. uncinella leaves using organic solvents and chromatographic procedures. L. (L.) amazonensis-infected BALB/c mice were treated intraperitoneally with triterpenic fraction during five consecutive days with 1.0 and 5.0 mg/kg of triterpenic fraction, or with 10.0 mg/kg of amphotericin B drug. Groups of mice treated with the triterpenic fraction, presented with decreased lesion size and low parasitism of the skin-both of which were associated with high amounts of interleukin-12 and interferon gamma. The curative effect of this fraction was similar to amphotericin B-treated mice; however, the final dose, required to eliminate amastigotes, was lesser than amphotericin B. Moreover, triterpenic fraction did not cause microscopic alterations in liver, spleen, heart, lung, and kidney of experimental groups. This work suggests that this fraction possesses compounds that are characterized by leishmanicidal and immunomodulatory activities. From this perspective, the triterpenic fraction can be explored as a new therapeutic agent for use against American Tegumentar Leishmaniasis.
Assuntos
Baccharis/química , Leishmania/efeitos dos fármacos , Leishmaniose Cutânea/tratamento farmacológico , Extratos Vegetais/farmacologia , Células Th1/imunologia , Triterpenos/farmacologia , Anfotericina B/farmacologia , Animais , Imunidade Celular , Interferon gama/imunologia , Interleucina-12/imunologia , Leishmaniose Cutânea/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Ácido Oleanólico/farmacologia , Carga Parasitária , Folhas de Planta/química , Ácido UrsólicoRESUMO
BACKGROUND: Mucosal alterations after Roux-en-Y gastric bypass for morbid obesity have not been clearly evaluated. This study aims to analyze the mucosal alterations (proliferative status (Ki-67); apoptosis (caspase-3 and BCL-2); hormonal function (gastrin)) in the excluded stomach. METHODS: Double-balloon enteroscopy was performed in 35 patients who underwent Roux-en-Y gastric bypass longer than 36 months. Multiple biopsies of the proximal pouch and the excluded gastric mucosa were collected. Gastric biopsies from 32 non-operated obese patients were utilized as controls. Endoscopic biopsies were cut from tissue blocks fixed in formalin and embedded in paraffin. Sections 4 µm thick were examined for immunoexpression using the streptavidin-biotin-peroxidase method. RESULTS: The two groups were comparable for age, gender, gastritis, intestinal metaplasia, and Helicobacter pylori. The mean number of positive gastrin cells was 55.5 (standard deviation (SD) = 11.7) in the control group and 29.6 (SD = 7.9) in the cases, p = 0.0003. Ki-67 proliferative index in cases (body = 24.7%, antrum = 24.9%) was significantly higher compared to controls (body = 15.0% and antrum = 17.7%), p = 0.002 and 0.01, respectively. Caspase-3 immunoexpression was higher in the controls compared to the excluded stomach (46 vs. 31%), p = 0.02. There was no statistical difference between CD3, CD8, and Bcl-2 immunoexpressions in the control and cases. CONCLUSIONS: Cell proliferation is increased and apoptosis is downregulated in the excluded gastric mucosa compared to the non-operated obese controls. Alterations in cell turnover and in hormonal secretions in these conditions may be of relevance in long-term follow-up.
Assuntos
Células Epiteliais/patologia , Derivação Gástrica , Mucosa Gástrica/patologia , Coto Gástrico/patologia , Obesidade Mórbida/patologia , Adolescente , Adulto , Idoso , Brasil , Caspase 3/metabolismo , Proliferação de Células , Enteroscopia de Duplo Balão , Regulação para Baixo , Feminino , Mucosa Gástrica/microbiologia , Gastrinas/metabolismo , Gastrite/patologia , Infecções por Helicobacter/patologia , Helicobacter pylori/isolamento & purificação , Humanos , Imuno-Histoquímica , Antígeno Ki-67/metabolismo , Masculino , Pessoa de Meia-Idade , Obesidade Mórbida/microbiologia , Obesidade Mórbida/cirurgiaRESUMO
This was a cross-sectional study which analyzed the prevalence and the clinical and immunological spectrum of canine Leishmania (L.) infantum chagasi infection in a cohort of 320 mongrel dogs living in an endemic area of American visceral leishmaniasis in the Amazonian Brazil by using, mainly, the indirect fluorescence antibody test (IFAT-IgG) and the delayed-type hypersensitivity (DTH), and the parasite research by the popliteal lymph node aspiration. The IFAT and DTH reactivity recognized three different immune response profiles: (1) IFAT((+))/DTH((-)) (107 dogs), (2) IFAT((-))/DTH((+)) (18 dogs), and (3) IFAT((+))/DTH((+)) (13 dogs), providing an overall prevalence of infection of 43% (138/320). Thus, the specific prevalence of IFAT( (+) )/DTH( (-) ) 33.4% (107/320) was higher than those of IFAT( (-) )/DTH( (+) ) 5.6% (18/320) and IFAT( (+) )/DTH( (+) ) 4.0% (13/320). Moreover, the frequency of these profiles among 138 infected dogs showed that the IFAT( (+) )/DTH( (-) ) rate of 77.5% (107/138) was also higher than those of 13.0% (18/138) of IFAT( (-) )/DTH( (+) ) and 9.5% (13/138) of IFAT( (+) )/DTH( (+) ) rates. The frequency of asymptomatic dogs (76%-105) was higher than those of symptomatic (16.6%-23) and oligosymptomatic ones (7.4%-10). A total of 16 (11.6%) L. (L.) i. chagasi isolates were obtained from infected dogs, all from the IFAT( (+) ) /DTH( (-) ) profile: 41% (9/22) from symptomatic, 33.3% (3/9) from oligosymptomatic, and 5.2% (4/76) from asymptomatic dogs. These findings strongly suggested that despite the higher frequency of asymptomatic dogs (76%-105), the majority (72.4%-76) was characterized by the IFAT( (+) ) /DTH( (-) ) profile with a doubtful immunogenetic resistance against infection.
Assuntos
Anticorpos Antiprotozoários/sangue , Doenças do Cão/epidemiologia , Doenças do Cão/imunologia , Hipersensibilidade Tardia/epidemiologia , Imunoglobulina G/sangue , Leishmania infantum/patogenicidade , Leishmaniose Visceral/veterinária , Animais , Brasil/epidemiologia , Estudos Transversais , Doenças do Cão/parasitologia , Cães , Feminino , Técnica Indireta de Fluorescência para Anticorpo/métodos , Leishmania infantum/imunologia , Leishmaniose Visceral/complicações , Leishmaniose Visceral/imunologia , Leishmaniose Visceral/parasitologia , Masculino , PrevalênciaRESUMO
In Amazonian Brazil, the Cebus apella monkey (Primates: Cebidae) has been associated with the enzootic cycle of Leishmania (V.) shawi, a dermotropic parasite causing American cutaneous leishmaniasis (ACL). It has also been successfully used as animal model for studying cutaneous leishmaniasis. In this work, there has been investigated its susceptibility to experimental Leishmania (L.) infantum chagasi-infection, the etiologic agent of American visceral leishmaniasis (AVL). There were used ten C. apella specimens, eight adult and two young, four males and six females, all born and raised in captivity. Two experimental infection protocols were performed: i) six monkeys were inoculated, intra-dermal via (ID), into the base of the tail with 2 x 10(6) promastigotes forms from the stationary phase culture medium; ii) other four monkeys were inoculated with 3 x 10(7) amastigotes forms from the visceral infection of infected hamsters by two different via: a) two by intravenous via (IV) and, b) other two by intra-peritoneal via (IP). The parameters of infection evaluation included: a) clinical: physical exam of abdomen, weigh and body temperature; b) parasitological: needle aspiration of the bone-marrow for searching of amastigotes (Giemsa-stained smears) and promastigotes forms (culture medium); c) immunological: Indirect fluorescence antibody test (IFAT) and, Delayed-type hypersensitivity (DTH). In the six monkeys ID inoculated (promastigotes forms) all parameters of infection evaluation were negative during the 12 months period of follow-up. Among the four monkeys inoculated with amastigotes forms, two IV inoculated showed the parasite in the bone-marrow from the first toward to the sixth month p.i. and following that they cleared the infection, whereas the other two IP inoculated were totally negative. These four monkeys showed specific IgG-antibody response since the third month p.i. (IP: 1/80 and IV: 1/320 IgG) toward to the 12th month (IP: 1/160 and IV: 1/5120). The DTH-conversion occurred in only one IV inoculated monkey with a strong (30 mm) skin reaction. Considering these results, we do not encourage the use of C. apella monkey as animal model for studying the AVL.
Assuntos
Anticorpos Antiprotozoários/imunologia , Cebus/parasitologia , Imunoglobulina G/imunologia , Leishmania infantum/patogenicidade , Leishmaniose Visceral/parasitologia , Doenças dos Macacos/parasitologia , Animais , Cebus/imunologia , Modelos Animais de Doenças , Suscetibilidade a Doenças , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Leishmaniose Visceral/imunologia , Masculino , Doenças dos Macacos/imunologiaRESUMO
In Amazonian Brazil, the Cebus apella monkey (Primates: Cebidae) has been associated with the enzootic cycle of Leishmania (V.) shawi, a dermotropic parasite causing American cutaneous leishmaniasis (ACL). It has also been successfully used as animal model for studying cutaneous leishmaniasis. In this work, there has been investigated its susceptibility to experimental Leishmania (L.) infantum chagasi-infection, the etiologic agent of American visceral leishmaniasis (AVL). There were used ten C. apella specimens, eight adult and two young, four males and six females, all born and raised in captivity. Two experimental infection protocols were performed: i) six monkeys were inoculated, intra-dermal via (ID), into the base of the tail with 2 x 10(6) promastigotes forms from the stationary phase culture medium; ii) other four monkeys were inoculated with 3 x 10(7) amastigotes forms from the visceral infection of infected hamsters by two different via: a) two by intravenous via (IV) and, b) other two by intra-peritoneal via (IP). The parameters of infection evaluation included: a) clinical: physical exam of abdomen, weigh and body temperature; b) parasitological: needle aspiration of the bone-marrow for searching of amastigotes (Giemsa-stained smears) and promastigotes forms (culture medium); c) immunological: Indirect fluorescence antibody test (IFAT) and, Delayed-type hypersensitivity (DTH). In the six monkeys ID inoculated (promastigotes forms) all parameters of infection evaluation were negative during the 12 months period of follow-up. Among the four monkeys inoculated with amastigotes forms, two IV inoculated showed the parasite in the bone-marrow from the first toward to the sixth month p.i. and following that they cleared the infection, whereas the other two IP inoculated were totally negative. These four monkeys showed specific IgG-antibody response since the third month p.i. (IP: 1/80 and IV: 1/320 IgG) toward to the 12th month (IP: 1/160 and IV: 1/5120). The DTH-conversion occurred in only one IV inoculated monkey with a strong (30 mm) skin reaction. Considering these results, we do not encourage the use of C. apella monkey as animal model for studying the AVL.
Na Amazônia Brasileira, o macaco Cebus apella (Primata: Cebidae) tem sido associado com o ciclo enzoótico da Leishmania (V.) shawi, um parasito dermotrópico causador da Leishmaniose Tegumentar Americana (LTA). Ele tem sido também empregado com sucesso como modelo experimental para estudo da leishmaniose tegumentar. Neste trabalho, foi investigada sua susceptibilidade à infecção experimental por Leishmania (L.) infantum chagasi, o agente etiológico da Leishmaniose Visceral Americana (LVA). Foram usados dez espécimes de C. apella oito adultos e dois jovens, quatro machos e seis fêmeas, todos nascidos e criados em cativeiro. Dois protocolos de infecção experimental foram feitos: i) seis macacos foram inoculados por via intradérmica (ID), na base da cauda com 2x10(6) formas promastigotas em fase estacionária de crescimento; ii) outros quatro macacos foram inoculados com 3x10(7) formas amastigotas de infecção visceral de hamsteres por duas vias diferentes: a) dois por via intravenosa (IV) e, b) outros dois pela via intraperitoneal (IP). A avaliação da infecção incluiu parâmetros: clínico: exame físico do abdômen, peso e temperatura corporal; b) parasitológico: aspirado de medula óssea por agulha para procura de amastigotas (esfregaço corado por Giemsa) e formas promastigotas (meio de cultura); c) imunológico: Reação de Imunofluorescência Indireta (RIFI) e, resposta de hipersensibilidade tardia (DTH). Nos seis macacos inoculados ID (formas promastigotas) todos os parâmetros de avaliação da infecção foram negativos durante o período de 12 meses. Entre os quatro macacos inoculados com formas amastigotas, dois inoculados IV mostraram parasitos na medula óssea do primeiro ao sexto mês p.i. e em seguida houve a resolução da infecção, no entanto os outros dois inoculados IP foram totalmente negativos. Esses quatro macacos apresentaram resposta específica de anticorpo IgG desde o terceiro mês p.i. (IP: 1/80 e IV: 1/320) até o décimo segundo mês (IP: 1/160 e IV: 1/5120). A conversão DTH ocorreu em apenas um macaco inoculado IV com uma forte reação na pele (30 mm). Considerando esses resultados, nós não recomendamos o uso do macaco C. apella como modelo animal para estudo da LVA.
Assuntos
Animais , Feminino , Masculino , Anticorpos Antiprotozoários/imunologia , Cebus/parasitologia , Imunoglobulina G/imunologia , Leishmania infantum/patogenicidade , Leishmaniose Visceral/parasitologia , Doenças dos Macacos/parasitologia , Cebus/imunologia , Modelos Animais de Doenças , Suscetibilidade a Doenças , Técnica Indireta de Fluorescência para Anticorpo , Leishmaniose Visceral/imunologia , Doenças dos Macacos/imunologiaRESUMO
Paraffin-embedded samples commonly stored at educational and research institutions constitute tissues banks for follow-up or epidemiological studies; however, the paraffin inclusion process involves the use of substances that can cause DNA degradation. In this study, a PCR protocol was applied to identify Leishmania strains in 33 paraffin-embedded skin samples of patients with American cutaneous leishmaniasis. DNA was obtained by the phenol-chloroform protocol following paraffin removal and then used in PCR or nested PCR based on the nucleotide sequence of the small subunit ribosomal RNA (SSU rDNA). The amplicons obtained were cloned and sequenced to determine the single nucleotide polymorphism that distinguishes between different Leishmania species or groups. This assay allowed to distinguish organisms belonging to the subgenus Viannia and identify L. (Leishmania) amazonensis and L. (L.) chagasi of the Leishmania subgenus. Of the 33 samples, PCR and nested PCR identified 91% of samples. After sequencing the PCR product of 26 samples, 16 were identified as L. (L.) amazonensis, the other 10 contain organisms belonging to the L. (Viannia) sub-genus. These results open a huge opportunity to study stored samples and promote relevant contributions to epidemiological studies.
Assuntos
DNA Ribossômico/genética , Leishmania/genética , Leishmaniose Cutânea/parasitologia , Reação em Cadeia da Polimerase/métodos , Sequência de Bases , DNA de Protozoário/análise , DNA de Protozoário/genética , DNA Ribossômico/isolamento & purificação , Leishmania/isolamento & purificação , Inclusão em Parafina , Polimorfismo de Fragmento de Restrição , RNA Ribossômico/genética , Subunidades Ribossômicas Menores , Alinhamento de Sequência , Pele/parasitologia , Fatores de TempoRESUMO
Canine visceral leishmaniasis (CVL) is recognizable by characteristic signs of disease and is highly lethal. The infection, however, may be quite inapparent in some seropositive dogs, and this has raised the polemic question as to whether or not such animals can be a source of infection for Lutzomyia longipalpis, the vector of American visceral leishmaniasis (AVL). In this study we have examined 51 dogs with acute CVL from an AVL area in Pará State, northern Brazil, and compared the parasite density, amastigotes of Leishmania (L.) infantum chagasi, in the skin, lymph node and viscera of symptomatic with that of nine asymptomatic but seropositive dogs (IFAT-IgG). Post-mortem biopsy fragments of these tissues were processed by immunohistochemistry, using a polyclonal antibody against Leishmania sp. The X² and Mann Whitney tests were used to evaluate the means of infected macrophage density (p < 0.05). There was no difference (p > 0.05) in the skin (10.7/mm² x 15.5/mm²) and lymph node (6.3/mm² x 8.3/mm²), between asymptomatic and symptomatic dogs, respectively. It was higher (p < 0.05), however, in the viscera of symptomatic (5.3/mm²) than it was in asymptomatic (1.4/mm²) dogs. These results strongly suggest that asymptomatic or symptomatic L. (L.) i. chagasi-infected dogs can serve as a source of infection, principally considering the highest (p < 0.05) parasite density from skin (10.7/mm² x 15.5/mm²), the place where the vetor L. longipalpis takes its blood meal, compared with those from lymph node (6.3/mm² x 8.3/mm²) and viscera (1.4/mm²x 5.3/mm²).
Assuntos
Doenças do Cão/parasitologia , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/veterinária , Linfonodos/parasitologia , Vísceras/parasitologia , Animais , Brasil , Doenças do Cão/transmissão , Cães , Feminino , Imuno-Histoquímica , Insetos Vetores , Leishmaniose Visceral/parasitologia , Leishmaniose Visceral/transmissão , Masculino , Psychodidae , Pele/parasitologiaRESUMO
Canine visceral leishmaniasis (CVL) is recognizable by characteristic signs of disease and is highly lethal. The infection, however, may be quite inapparent in some seropositive dogs, and this has raised the polemic question as to whether or not such animals can be a source of infection for Lutzomyia longipalpis, the vector of American visceral leishmaniasis (AVL). In this study we have examined 51 dogs with acute CVL from an AVL area in Pará State, northern Brazil, and compared the parasite density, amastigotes of Leishmania (L.) infantum chagasi, in the skin, lymph node and viscera of symptomatic with that of nine asymptomatic but seropositive dogs (IFAT-IgG). Post-mortem biopsy fragments of these tissues were processed by immunohistochemistry, using a polyclonal antibody against Leishmania sp. The X² and Mann Whitney tests were used to evaluate the means of infected macrophage density (p < 0.05). There was no difference (p > 0.05) in the skin (10.7/mm² x 15.5/mm²) and lymph node (6.3/mm² x 8.3/mm²), between asymptomatic and symptomatic dogs, respectively. It was higher (p < 0.05), however, in the viscera of symptomatic (5.3/mm²) than it was in asymptomatic (1.4/mm²) dogs. These results strongly suggest that asymptomatic or symptomatic L. (L.) i. chagasi-infected dogs can serve as a source of infection, principally considering the highest (p < 0.05) parasite density from skin (10.7/mm² x 15.5/mm²), the place where the vetor L. longipalpis takes its blood meal, compared with those from lymph node (6.3/mm² x 8.3/mm²) and viscera (1.4/mm²x 5.3/mm²).
A leishmaniose visceral canina (LVC) é reconhecida pelas características clínicas da doença e é altamente letal. A infecção, entretanto, pode ser totalmente assintomática em alguns cães soropositivos, o que tem levantado questão polêmica sobre a possibilidade desses animais, serem ou não uma fonte importante da infecção para o flebotomíneo, Lutzomyia longipalpis, o principal vetor da leishmaniose visceral americana (LVA). Neste estudo foram examinados 51 cães com LVC aguda, provenientes de área endêmica de LVA no Estado do Pará, Brasil, e a carga parasitária, formas amastigotas de Leishmania (L.) infantum chagasi, na pele, linfonodo poplíteo e vísceras (fígado e baço) foi comparada com a de nove cães assintomáticos soropositivos (IFAT-IgG). Fragmentos de biópsia desses tecidos obtidos post-mortem foram processados para análise através de imunohistoquímica, usando um anticorpo policlonal contra Leishmania sp. Os testes do Qui-quadrado (X²) e Mann Whitney foram usados para avaliar as médias da densidade de macrófagos infectados (p < 0,05). Os resultados mostraram que não houve diferença (p > 0,05) na densidade de macrófagos infectados da pele (10,7/mm² x 15,5/mm²) e do linfonodo (6,3/mm² x 8,3/mm²) entre cães assintomáticos e sintomáticos. Entretanto, a densidade de macrófagos infectados da víscera de cães sintomáticos (5,3/mm²) foi maior (p < 0,05) que a de cães assintomáticos (1,4/mm²). Estes resultados sugerem, fortemente, que cães naturalmente infectados por L. (L.) i. chagasi, assintomáticos ou sintomáticos, podem servir como fonte de infecção, principalmente, considerando-se que a densidade de macrófagos infectados da pele (10,7/mm² x 15,5/mm²), local onde o flebotomíneo vetor Lu. longipalpis realiza a hematofagia, foi maior (p < 0,05) que as do linfonodo (6,3/mm² x 8.3/mm²) e vísceras (1,4/mm²x 5,3/mm²).
Assuntos
Animais , Cães , Feminino , Masculino , Doenças do Cão/parasitologia , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/veterinária , Linfonodos/parasitologia , Vísceras/parasitologia , Brasil , Doenças do Cão/transmissão , Imuno-Histoquímica , Insetos Vetores , Leishmaniose Visceral/parasitologia , Leishmaniose Visceral/transmissão , Psychodidae , Pele/parasitologiaRESUMO
This prospective study was carried out from October 2003 to December 2005 and involved a cohort of 946 individuals of both genders, aged 1-89 years, from an endemic area for American visceral leishmaniasis (AVL), in Pará State, Brazil. The aim of the study was to analyze the dynamics of the clinical and immunological evolution of human Leishmania (L.) infantum chagasi infection represented by the following clinical-immunological profiles: asymptomatic infection (AI); symptomatic infection (SI=AVL); subclinical oligosymptomatic infection (SOI); subclinical resistant infection (SRI); and indeterminate initial infection (III). Infection diagnosis was determined by the indirect fluorescent antibody test and leishmanin skin test. In total, 231 cases of infection were diagnosed: the AI profile was the most frequent (73.2%), followed by SRI (12.1%), III (9.9%), SI (2.6%) and SOI (2.2%). The major conclusion regarding evolution dynamics was that the III profile plays a pivotal role from which the cases evolve to either the resistant, SRI and AI, or susceptible, SOI and SI, profiles; only one of the 23 III cases evolved to SI, while most evolved to either SRI (nine cases) or SOI (five cases) and eight cases remained as III.
Assuntos
Anticorpos Antiprotozoários/imunologia , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Brasil/epidemiologia , Criança , Pré-Escolar , Cães , Feminino , Técnica Indireta de Fluorescência para Anticorpo/métodos , Humanos , Lactente , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/transmissão , Masculino , Pessoa de Meia-Idade , Prevalência , Estudos Prospectivos , Testes Cutâneos , Adulto JovemRESUMO
The objectives of this study were to identify individuals with symptomatic and/or asymptomatic infection due to Leishmania (L.) infantum chagasi; to study the two types of infection, both clinically and immunologically, and to determine the prevalence rate of infection at the beginning of the study. This was a cross-sectional study with a cohort of 946 individuals, of both genders, from the age of 1 year, living in the municipality of Barcarena, PA, Brazil, an area endemic for American visceral leishmaniasis (AVL). The leishmanin skin test (LST) and the indirect fluorescent test (IFAT), were used for the diagnosis of infection. One hundred and twenty cases of infection were diagnosed, with a prevalence rate of 12.6%; eight cases showed high seroreactivity (1280-10240, IgG) in IFAT and no LST reaction; four of these cases were typical AVL and four had subclinical oligosymptomatic infection. Using two immunological methods with a clinical examination of the infected individuals enabled the identification of five clinical-immunological profiles which may promote a better understanding of the interaction between L. (L.) i. chagasi and the human immune response: asymptomatic infection (AI) 73.4%; subclinical resistant infection (SRI) 15%; subclinical oligosymptomatic infection (SOI) 3%; symptomatic infection (AVL) 3% and indeterminate initial infection (III) 5%.
Assuntos
Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Brasil/epidemiologia , Criança , Pré-Escolar , Estudos de Coortes , Estudos Transversais , Feminino , Humanos , Lactente , Leishmania infantum/imunologia , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/epidemiologia , Masculino , Pessoa de Meia-Idade , Prevalência , Testes Cutâneos/métodos , Adulto JovemRESUMO
The purpose of this study was to describe the reproductive profile and frequency of genital infections among women living in the Serra Pelada, a former mining village in the Pará state, Brazil. A descriptive study of women living in the mining area of Serra Pelada was performed in 2004 through interviews that gathered demographics and clinical data, and assessed risk behaviors of 209 randomly-selected women. Blood samples were collected for rapid assay for HIV; specimens were taken for Pap smears and Gram stains. Standard descriptive statistical analyses were performed and prevalence was calculated to reflect the relative frequency of each disease. Of the 209 participants, the median age was 38 years, with almost 70% having less than four years of education and 77% having no income or under 1.9 times the minimum wage of Brazil. About 30% did not have access to health care services during the preceding year. Risk behaviors included: alcohol abuse, 24.4%; illicit drug abuse, 4.3%; being a sex worker, 15.8%; and domestic violence, 17.7%. Abnormal Pap smear was found in 8.6%. Prevalence rates of infection were: HIV, 1.9%; trichomoniasis, 2.9%; bacterial vaginosis, 18.7%; candidiasis, 5.7%; Chlamydial-related cytological changes, 3.3%; and HPV-related cytological changes, 3.8%. Women living in this mining area in Brazil are economically and socially vulnerable to health problems. It is important to point out the importance of concomitant broader strategies that include reducing poverty and empowering women to make improvements regarding their health.
Assuntos
Doenças dos Genitais Femininos/epidemiologia , Saúde da Mulher , Adulto , Brasil , Feminino , Humanos , Pessoa de Meia-Idade , Medicina Reprodutiva , Adulto JovemRESUMO
The purpose of this study was to describe the reproductive profile and frequency of genital infections among women living in the Serra Pelada, a former mining village in the Pará state,Brazil. A descriptive study of women living in the mining area of Serra Pelada was performed in 2004 through interviews that gathered demographics and clinical data, and assessed risk behaviors of 209 randomly-selected women. Blood samples were collected for rapid assay for HIV; specimens were taken for Pap smears and Gram stains. Standard descriptive statistical analyseswere performed and prevalence was calculated to reflect the relative frequency of each disease. Of the 209 participants, the median age was 38 years, with almost 70% having less thanfour years of education and 77% having no income or under 1.9 times the minimum wage of Brazil. About 30% did not have access to health care services during the preceding year. Risk behaviors included: alcohol abuse, 24.4%; illicit drug abuse, 4.3%; being a sex worker, 15.8%; and domestic violence, 17.7%. Abnormal Pap smear was found in 8.6%. Prevalence rates of infection were: HIV, 1.9%; trichomoniasis, 2.9%; bacterial vaginosis, 18.7%; candidiasis, 5.7%;Chlamydial-related cytological changes, 3.3%; and HPV-related cytological changes, 3.8%. Women living in this mining area in Brazil are economically and socially vulnerable to health problems. It is important to point out the importance of concomitant broader strategies that include reducing poverty and empowering women to make improvements regarding their health.
El propósito de este estudio fue describir el perfil reproductivo y la frecuencia de infecciones genitales en mujeres que viven en la población minera Serra Pelada en el Estado de Pará, Brasil. Se realizó un estudio descriptivo de las mujeres que vivían en la zona minera de Serra Pelada en 2004 mediante entrevistas en las que se recabarondatos demográficos y clínicos y se examinaron las conductas de riesgo de 209 mujeres seleccionadas aleatoriamente. Se tomaron muestras de sangre para pruebas rápidas de detección de anticuerpos contra el VIH y muestras de tejido para análisis citológico y tinción de Gram. Se calculó la prevalencia y se utilizaron pruebas estadísticas descriptivas estándares para caracterizar la frecuencia relativa de cada enfermedad. La mediana de la edad de las 209 participantes fue de 38 años; 70% tenía menos de cuatro años de escolaridad y 77% no tenía ingresos o estos eran inferiores a 1,9 veces elsalario mínimo en Brasil. Alrededor de 30% no tuvo acceso a servicios de salud durante el año previo. Entre las conductas de riesgo estaban: consumo de bebidas alcohólicas (24,4%) y de drogas ilícitas (4,3%), ser trabajadora sexual (15,8%) y violencia doméstica (17,7%). Se encontraron resultados anormales a la prueba citológica en8,6% de las participantes. Las prevalencias de infección fueron: 1,9% de VIH, 2,9% de tricomoniasis, 18,7% de vaginosis bacteriana y 5,7% de candidiasis; 3,3% presentó alteracionescitológicas asociadas con la infección por clamidia y 3,8% alteraciones citológicas asociadas con el virus de papiloma humano. Las mujeres de esta zona minera de Brasil son económica y socialmente vulnerables a problemas de salud. Es importante señalar la importancia de estrategias concomitantes más amplias que abarquen la reducción de la pobreza y el empoderamiento de las mujeres para lograr mejoras en su salud.
Assuntos
Humanos , Feminino , Adulto , Pessoa de Meia-Idade , Adulto Jovem , Doenças dos Genitais Femininos/epidemiologia , Saúde da Mulher , Brasil , Medicina Reprodutiva , Adulto JovemRESUMO
This was a longitudinal study carried out during a period over 2 years with a cohort of 946 individuals of both sexes, aged 1 year and older, from an endemic area of American visceral leishmaniasis (AVL) in Pará State, Brazil. The object was to analyze the transmission dynamics of human Leishmania (Leishmania) infantum chagasi infection based principally on the prevalence and incidence. For diagnosis of the infection, the indirect fluorescent antibody test (IFAT) and leishmanin skin test (LST) were performed with amastigote and promastigote antigens of the parasite, respectively. The prevalence by LST (11.2%) was higher (p < 0.0001) than that (3.4%) by IFAT, and the combined prevalence by both tests was 12.6%. The incidences by LST were also higher (p < 0.05) than those by IFAT at 6 (4.7% x 0.6%), 12 (4.7% x 2.7%), and 24 months (2.9% x 0.3%). Moreover, there were no differences (p > 0.05) between the combined incidences by both tests on the same point surveys, 5.2%, 6.3%, and 3.6%. During the study, 12 infected persons showed high IFAT IgG titers with no LST reactions: five children and two adults developed AVL (2,560-10,120), and two children and three adults developed subclinical oligosymptomatic infection (1280-2560). The combined tests diagnosed a total of 231 cases of infection leading to an accumulated prevalence of 24.4%.
Assuntos
Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/transmissão , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Anticorpos Antiprotozoários/sangue , Antígenos de Protozoários , Brasil/epidemiologia , Criança , Pré-Escolar , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Incidência , Lactente , Leishmaniose Visceral/diagnóstico , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Prevalência , Testes Cutâneos , Adulto JovemAssuntos
Saúde da Mulher , Mineração , Doenças Genitais , Grupos de Risco , Saúde da Mulher , Mineração , Doenças dos Genitais Femininos , Grupos de Risco , Acessibilidade aos Serviços de Saúde , Medicina Reprodutiva , Adulto Jovem , Acessibilidade aos Serviços de Saúde , Brasil , Brasil , Doenças dos Genitais Femininos , Saúde da MulherRESUMO
The role of dendritic Langerhans cells (LCs) in the immunopathogenesis of American cutaneous leishmaniasis (ACL) was reviewed in the light of more recent clinical and immunological features of ACL, caused by the principal human pathogenic leishmanial parasites found in Brazil: Leishmania (Viannia) braziliensis and L. (L.) amazonensis. The report shows a species-specific correlation between the LC density and the CD4+ and CD8+ T-cell profiles in the cellular infiltrate of skin lesions of ACL patients, providing the conclusion that LCs might be influencing the dichotomy of interaction between L. (V.) braziliensis and L. (L.) amazonensis with the human T-cell immune response. While L. (V.) braziliensis shows a clear tendency to direct infection to the hypersensitivity pole of the ACL clinical-immunological spectrum marked by a strong Th1-type immune response, L. (L.) amazonensis shows the opposite, directing infection to the hyposensitivity pole associated with a marked Th2-type immune response. These are probably the main immunological mechanisms of LCs regarding the immune response dichotomy that modulates infection outcome by these Leishmania parasites.
Assuntos
Anticorpos Antiprotozoários/imunologia , Células de Langerhans/imunologia , Leishmania/imunologia , Leishmaniose Cutânea/imunologia , Linfócitos T/imunologia , Animais , Brasil , Interações Hospedeiro-Parasita , Humanos , Leishmania/classificação , Leishmania/parasitologiaRESUMO
Molecular characterization of Cryptosporidium spp.oocysts in clinical samples is useful for public health since it allows the study of sources of contamination as well as the transmission in different geographical regions. Although widely used in developed countries, in Brazil it is restricted to academic studies, mostly using commercial kits for the extraction of genomic DNA, or in collaboration with external reference centers, rendering the method expensive and limited. The study proposes the application of the modifications recently introduced in the method improving feasibility with lower cost. This method was efficient for clinical samples preserved at -20 degrees C for up to six years and the low number of oocysts may be overcome by repetitions of extraction.