Role of antigen-presenting cells in non-ulcerated skin lesions caused by Leishmania (Leishmania) infantum chagasi.

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.

Macrophage Polarization in the Skin Lesion Caused by Neotropical Species of Leishmania sp.

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.

Host and parasite responses in human diffuse cutaneous leishmaniasis caused by L. amazonensis.

Diffuse cutaneous leishmaniasis (DCL) is a rare form of leishmaniasis where parasites grow uncontrolled in diffuse lesions across the skin. Meta-transcriptomic analysis of biopsies from DCL patients infected with Leishmania amazonensis demonstrated an infiltration of atypical B cells producing a surprising preponderance of the IgG4 isotype. DCL lesions contained minimal CD8+ T cell transcripts and no evidence of persistent TH2 responses. Whereas localized disease exhibited activated (so-called M1) macrophage presence, transcripts in DCL suggested a regulatory macrophage (R-Mϕ) phenotype with higher levels of ABCB5, DCSTAMP, SPP1, SLAMF9, PPARG, MMPs, and TM4SF19. The high levels of parasite transcripts in DCL and the remarkable uniformity among patients afforded a unique opportunity to study parasite gene expression in this disease. Patterns of parasite gene expression in DCL more closely resembled in vitro parasite growth in resting macrophages, in the absence of T cells. In contrast, parasite gene expression in LCL revealed 336 parasite genes that were differently upregulated, relative to DCL and in vitro macrophage growth, and these transcripts may represent transcripts that are produced by the parasite in response to host immune pressure.

Effectiveness of an immunohistochemical protocol for Leishmania detection in different clinical forms of American tegumentary leishmaniasis.

American tegumentary leishmaniasis (ATL) is a neglected disease widely distributed in Latin America. In Brazil, it is caused by different Leishmania species belonging to the Subgenera Viannia and Leishmania. ATL diagnosis is routinely based on clinical, epidemiological, parasitological and immunological (delayed-type hypersensitivity skin test-DTH) evidences. The main objective of this work was to determine the efficacy of a previous immunohistochemical (IHC) method developed by our group. Seventy eight skin biopsies from patients with different ATL clinical forms and origins were evaluated. The method was previously standardized in ATL patients from the municipality of Caratinga, Minas Gerais, Brazil, all infected with Leishmania (V.) braziliensis. Here, it is evaluated in patients from the North, Southeast and Midwest regions of Brazil. Clinical, parasitological (biopsy PCR) and immunological (Montenegro skin test-MST) diagnosis were performed prior to IHC procedure. The IHC procedure detected 70.5% of the cases having a high agreement with MST diagnosis (kappa=0.84). A distinguished contribution of this work is that IHC succeed in diagnosing some negative DTH patients. Those were infected with Leishmania (L.) amazonensis, commonly causing the anergic form of the disease. In conclusion, IHC succeed in detecting ATL caused by different Leishmania species from various geographic regions and clinical status. Although it was not able to detect ATL in all patients, it was better than MST providing an additional tool for the diagnosis of ATL patients. There was no significant correlation between clinical forms and histological features including the presence of necrosis.

Genome-Wide Association Study of Cell-Mediated Response in Dogs Naturally Infected by Leishmania infantum.

A genome-wide association study (GWAS) could unravel the complexity of the cell-mediated immunity (CMI) to canine leishmaniasis (CanL). Therefore, we scanned 110,165 single-nucleotide polymorphisms (SNPs), aiming to identify chromosomal regions associated with the leishmanin skin test (LST), lymphocyte proliferation assay (LPA), and cytokine responses to further understand the role played by CMI in the outcome of natural Leishmania infantum infection in 189 dogs. Based on LST and LPA, four CMI profiles were identified (LST-/LPA-, LST+/LPA-, LST-/LPA+, and LST+/LPA+), which were not associated with subclinically infected or diseased dogs. LST+/LPA+ dogs showed increased interferon gamma (IFN-γ) and tumor necrosis factor alpha (TNF-α) levels and mild parasitism in the lymph nodes, whereas LST-/LPA+ dogs, in spite of increased IFN-γ, also showed increased interleukin-10 (IL-10) and transforming growth factor ß (TGF-ß) levels and the highest parasite load in lymph nodes. Low T cell proliferation under low parasite load suggested that L. infantum was not able to induce effective CMI in the early stage of infection. Altogether, genetic markers explained 87%, 16%, 15%, 11%, 0%, and 0% of phenotypic variance in TNF-α, TGF-ß, LST, IL-10, IFN-γ, and LPA, respectively. GWAS showed that regions associated with TNF-α include the following genes: IL12RB1, JAK3, CCRL2, CCR2, CCR3, and CXCR6, involved in cytokine and chemokine signaling; regions associated with LST, including COMMD5 and SHARPIN, involved in regulation of NF-κB signaling; and regions associated with IL-10, including LTBP1 and RASGRP3, involved in T regulatory lymphocytes differentiation. These findings pinpoint chromosomic regions related to the cell-mediated response that potentially affect the clinical complexity and the parasite replication in canine L. infantum infection.

Diagnóstico molecular e frequência de anticorpos anti-Leishmania infantum chagasi em cães do município de Belém, Pará / Molecular diagnosis and frequency of anti-Leishmania infantum chagasi antibodies in dogs in Belém/Pará, Brazil

Visceral leishmaniasis is a disease whose etiological agent in Brazil is Leishmania infantum chagasi. Dogs are considered urban reservoirs of the disease, being an indicator of the human cases occurrence. The present study aimed to diagnose L. infantum chagasi infection in stray and owned dogs in Belém, Pará State, by polymerase chain reaction (PCR) and indirect immunofluorescence assay (IFA) using two different antigens. [...] These animals were divided into two groups: stray dogs captured by the Center for Zoonosis Control (Group A) and owned dogs (Group B). Sera were analyzed by IFA testing for IgG using two different antigens: 1) Bio-Manguinhos/Fiocruz antigen kit (Ag-PRO) containing promastigotes of Leishmania sp. (Complex Major-Like), 2) Instituto Evandro Chagas Antigen (Ag-AMA) consisting of amastigotes of L. infantum chagasi. The evaluation of the two antigens was performed considering positive the reactions above the 1:80 dilution. Already PCR was performed with DNA isolated from whole blood of animals and amplified with the primers RV1 and RV2. Of the 335 samples analyzed, 10.4% (35/335) were positive by IFA (Ag-PRO) and 0.9% (3/335) with the Ag-AMA. The distribution of positive samples is given as follows: Group A 14.8% (25/169) with Ag-PRO and 1.2% (2/169) with Ag-AMA; Group B 6% (10/166) with Ag-PRO and 0.6% (1/166) with Ag-AMA, being that all samples positive by IFA with Ag-AMA also reacted with Ag-PRO, and none of the samples detected DNA of L. infantum chagasi. The findings of this study indicate that Belém can still be considered non-endemic area for canine visceral leishmaniasis and the nature of the antigen influences the result of the IFA for the detection of anti-L. infantum chagasi antibodies in dogs, and the IFA using promastigotes of Leishmania major-like antigen should be used with caution as a confirmatory diagnostic on epidemiological studies in non-endemic areas.

A leishmaniose visceral é uma enfermidade cujo agente etiológico no Brasil é o protozoário Leishmania infantum chagasi. Os cães são considerados reservatórios urbanos da doença, sendo indicadores da ocorrência de casos humanos. O presente trabalho teve como objetivo diagnosticar a infecção por L. infantum chagasi em cães domiciliados e errantes do município de Belém, estado do Pará, através da reação em cadeia da polimerase (PCR) e da reação de imunofluorescência indireta (RIFI), empregando dois antígenos distintos. [...] A avaliação dos dois antígenos foi realizada com as amostras reagentes a partir da titulação 1:80. Já a PCR foi realizada a partir do DNA extraído do sangue total dos animais e amplificado utilizando-se os iniciadores RV1e RV2. Das 335 amostras analisadas, 10,4% (35/335) foram reagentes na RIFI (Ag-PRO) e 0,9% (3/335) reagiram com o Ag-AMA. A distribuição das amostras positivas se deu da seguinte forma: Grupo A 14,8% (25/169) com Ag-PRO e 1,2% (2/169) com Ag-AMA; Grupo B 6% (10/166) com Ag-PRO e 0,6% (1/166) com Ag-AMA; sendo que todas as amostras positivas pelo teste de RIFI com o Ag-AMA também reagiram com o Ag-PRO e em nenhuma das amostras foi detectado o DNA de L. infantum chagasi. Os achados do presente estudo indicam que Belém ainda pode ser considerada área não endêmica para leishmaniose visceral canina e que a natureza do antígeno influencia no resultado da RIFI para a pesquisa de anticorpos anti-L. infantum chagasi em cães, sendo que a RIFI que utiliza formas promastigotas de Leishmania major-like como antígeno deve ser utilizada com cautela como método diagnóstico confirmatório em estudos epidemiológicos em áreas não endêmicas para LVC.

Phosphatidylserine exposure and surface sugars in two Leishmania (Viannia) braziliensis strains involved in cutaneous and mucocutaneous leishmaniasis.

BACKGROUND: Phosphatidylserine (PS) and surface carbohydrates (SC) are known as virulence factors that may contribute to the different clinical symptoms ranging from self-healing cutaneous leishmaniasis lesions to fatal visceral disease. Leishmania (Viannia) braziliensis causes localized cutaneous leishmaniasis (LCL) and mucocutaneous leishmaniasis (MCL). METHODS: We analyzed PS exposure and SC expression associated with 2 primary L. braziliensis isolates from patients with LCL or MCL. The role of PS exposure was also addressed during promastigotes phagocytosis by macrophages. RESULTS: We observed higher PS exposure on the surface of late stationary growth phase promastigotes from patients with LCL, compared with those from patients with MCL, and both strains were alive during PS display. Reduction in the infectivity index was observed during macrophage interaction with late stationary growth phase promastigotes in which PS was blocked by annexin V. The major surface carbohydrates detected on LCL and MCL promastigotes were α-Man, α-Glc, and α-Gal. However, α-ß-GalNAc, although observed on the surface of the LCL strain during the late stationary growth phase was highly expressed on the surface of early stationary growth phase promastigotes. CONCLUSIONS: Our results suggest that PS and SC can modulate interactions between Leishmania organisms and host cells and may be important for the outcome of the clinical course of diseases caused by L. braziliensis.

Revisão sobre a patogenia da leishmaniose tegumentar americana na Amazônia, com ênfase à doença causada por Leishmania (V. ) braziliensis e Leishmania (L. ) amazonensis / Revisiting the pathogenesis of the american tegumentary leishmaniasis in Amazonian, with emphasis to the disease due to Leishmania (V. ) braziliensis and Leishmania (L.) amazonensis

A patogenia da leishmaniose tegumentar americana (LTA) na Amazônia foi revisada à luz dos mais recentes aspectos associados ao espectro clínico, histopatológico e imunopatológico da doença causada por Leishmania (V.) braziliensis e Leishmania (L.) amazonensis. Esta revisão mostrou a existência de uma dicotomia entre as duas espécies de Leishmania e a resposta imune celular; enquanto a L. (V.) braziliensis mostra forte tendência em dirigir a infecção, a partir da forma central do espectro clínico-imunológico, a leishmaniose cutânea localizada (LCL), para o pólo imunológico hiperreativo, representado pela leishmaniose cutâneo-mucosa (LCM), com exacerbação da hipersensibilidade e perfil da resposta CD4 tipo-Thl, a L. (L.) amazonensis mostra o oposto, dirige a infecção para o pólo imunológico hiporreativo, representado pela leishmaniose cutânea anérgica difusa (LCAD), com forte inibição da hipersensibilidade e perfil da resposta CD4 tipo- Th2. Entre a forma central LCL e as formas polares LCM e LCAD a infecção passa por uma fase intermediária, a leishmaniose cutânea disseminada borderline (LCDB), com inibição parcial da hipersensibilidade e peifil da resposta CD4 Thl + Th2. Estes são, provavelmente, os principais mecanismos imunológicos que modulam a patogenia da LTA causada por L. (V.) braziliensis e L. (L.) amazonensis.

The pathogenesis of American tegumentary leishmaniasis (ATL) was reviewed ifl the light of more recent features of clinical, histopathological and immunopathological spectrum of disease caused by Leishmania (V.) braziliensis and Leishmania (L.) amazonensis. This review has shown a dichotomy in the interaction between these two species of Leishmania with the human .cellular immune response; while L. (V.) braziliensis shows a clear tendency to direct infection, from the localized cutaneous leishmaniasis (LCL) in the center of the clinical-immunological spectrum of disease, to the hyperactive immunologic pole represented by mucocutaneous leishmaniasis (MCL), which shows exacerbated hypersensitivity reaction and CD4 Thl-type immune response, L. (L.) amazonensis shows the opposite,. directing infection to the hypoactive immunologic pole consisted by anergic diffuse cutaneous leishmaniasis (ADCL), associated with a marked inhibition of hypersensitivity reaction and CD4 Th2type immune response. Between the central LCL and thetwo polar MCL and ADCL forms the infection may present an intermediary phase, borderline disseminated cutaneous leishmaniasis (BDCL), which shows partial inhibition of hypersensitivity reaction and a mixed CD4 Thl plus Th2 immune response. These are probably the main immunological mechanisms regarding the immune response dichotomy that modulates the pathogenesis of ATL caused by these Leishmania parasites.

Observations on Eimeria species of Dasyprocta leporina (Linnaeus, 1758)(Rodentia: Dasyproctidae) from the state of Pará, North Brazil

Redescriptions are given of the mature oocysts of Eimeria aguti Carini 1935, E. cotiae Carini, 1935 and E. paraensis Carini, 1935, in the faeces of five specimens of the rodent Dasyprocta leporina (Rodentia: Dasyproctidae) from the state of Pará, North Brazil. New information is provided on the sporulation time of these parasites and the prepatent period in experimentally infected D. leporina. Some endogenous stages of E. cotiae are described in the epithelial cells of the ileum, and the absence of any oocysts in the gall-bladder contents of the infected animals indicates that the intestine is also the site of development of E. aguti and E. paraensis. Difficulties in separating E. cotiae and E. paraensis on morphology of the oocysts are discussed. The oocysts of both parasites share many structural features and have a wide size range. It is concluded that although it is at present best to maintain these names, the possibility exists that they were separately given to oocysts of smaller dimensions (E. cotiae) and larger dimensions (E. paraensis) of a single parasite. Location of an endogenous site of development for E. paraensis that is distinctly separate from that of E. cotiae might establish more definitely the separate specific status of the two parasites.

Further observations on clinical, histopathological, and immunological features of borderline disseminated cutaneous leishmaniasis caused by Leishmania (Leishmania) amazonensis.

Leishmania (Leishmania) amazonensis has for some time been considered as the causative agent of two distinct forms of American cutaneous leishmaniasis (ACL): localized cutaneous leishmaniasis (LCL), and anergic diffuse cutaneous leishmaniasis (ADCL). Recently, a new intermediate form of disease, borderline disseminated cutaneous leishmaniasis (BDCL), was introduced into the clinical spectrum of ACL caused by this parasite, and in this paper we record the clinical, histopathological, and immunological features of eight more BDCL patients from Brazilian Amazonia, who acquired the disease in the Pará state, North Brazil. Seven of them had infections of one to two years' evolution and presented with primary skin lesions and the occurrence of metastases at periods varying from six to 12 months following appearance of the first lesion. Primary skin lesions ranged from 1-3 in number, and all had the aspect of an erythematous, infiltrated plaque, variously located on the head, arms or legs. There was lymphatic dissemination of infection, with lymph node enlargement in seven of the cases, and the delayed hypersensitivity skin-test (DTH) was negative in all eight patients prior to their treatment. After that, there was a conversion of DTH to positive in five cases re-examined. The major histopathological feature was a dermal mononuclear infiltration, with a predominance of heavily parasitized and vacuolated macrophages, together with lymphocytes and plasma cells. In one case, with similar histopathology, the patient had acquired his infection seven years previously and he presented with the largest number of disseminated cutaneous lesions. BDCL shows clinical and histopathological features which are different from those of both LCL and ADCL, and there is a good prognosis of cure which is generally not so in the case of frank ADCL.

Further observations on clinical, histopathological, and immunological features of borderline disseminated cutaneous leishmaniasis caused by Leishmania (Leishmania) amazonensis

Leishmania (Leishmania) amazonensis has for some time been considered as the causative agent of two distinct forms of American cutaneous leishmaniasis (ACL): localized cutaneous leishmaniasis (LCL), and anergic diffuse cutaneous leishmaniasis (ADCL). Recently, a new intermediate form of disease, borderline disseminated cutaneous leishmaniasis (BDCL), was introduced into the clinical spectrum of ACL caused by this parasite, and in this paper we record the clinical, histopathological, and immunological features of eight more BDCL patients from Brazilian Amazonia, who acquired the disease in the Pará state, North Brazil. Seven of them had infections of one to two years' evolution and presented with primary skin lesions and the occurrence of metastases at periods varying from six to 12 months following appearance of the first lesion. Primary skin lesions ranged from 1-3 in number, and all had the aspect of an erythematous, infiltrated plaque, variously located on the head, arms or legs. There was lymphatic dissemination of infection, with lymph node enlargement in seven of the cases, and the delayed hypersensitivity skin-test (DTH) was negative in all eight patients prior to their treatment. After that, there was a conversion of DTH to positive in five cases re-examined. The major histopathological feature was a dermal mononuclear infiltration, with a predominance of heavily parasitized and vacuolated macrophages, together with lymphocytes and plasma cells. In one case, with similar histopathology, the patient had acquired his infection seven years previously and he presented with the largest number of disseminated cutaneous lesions. BDCL shows clinical and histopathological features which are different from those of both LCL and ADCL, and there is a good prognosis of cure which is generally not so in the case of frank ADCL.

Clinical and immunopathological spectrum of American cutaneous leishmaniasis with special reference to the disease in Amazonian Brazil: a review

The wide variety of Leishmania species responsible for human American cutaneous leishmaniasis combined with the immune mechanisms of the host results in a large spectrum of clinical, histopathological, and immunopathological manifestations. At the middle of this spectrum are the most frequent cases of localized cutaneous leishmaniasis (LCL) caused by members of the subgenera Leishmania and Viannia, which respond well to conventional therapy. The two pathogenicity extremes of the spectrum generally recognized are represented at the hypersensitivity pole by mucocutaneous leishmaniasis (MCL) and at the hyposensitivity pole by anergic diffuse cutaneous leishmaniasis (ADCL). Following the present study on the clinical, histopathological and immunopathological features of cutaneous leishmaniasis in Amazonian Brazil, we propose the use of the term "borderline disseminated cutaneous leishmaniasis" for the disseminated form of the disease, due to parasites of the subgenera Leishmania and Viannia, which might be regarded as intermediate between LCL and the extreme pathogenicity poles MCL and ADCL.

Ensaio clínico aberto comparando a mefloquina e o antimoniato de meglumina no tratamento da leishmaniose tegumentar americana na Amazônia / Clinical study comparing mefloquina and antimony meglumina in the treatment of leishmaniose american tegumentar in Amazônia

Introdução: A Leishmaniose Tegumentar Americana (LTA) é uma doença responsável por considerável morbidade em áreas tropicais do mundo, cuja melhor forma de tratamento encontra-se indefinida. A resposta terapêutica à mefloquina foi avaliada comparando-se com o antimoniato de meglumina. Método: Dois grupos de tratamento com 30 pacientes cada, com diagnóstico parasitológico de LTA, foram constituídos: o primeiro tratado com mefloquina na dose de 4,2 mg/kg/dia, via oral, até uma dose acumulada de 4 g, divididos em 2 etapas, com intervalos de 20 dias e o segundo grupo recebeu antimoniato de meglumina 20 mg/kg/dia, intravenoso, por 20 dias consecutivos, repetidos com intervalo de 10 dias. A resposta terapêutica avaliada com base na intenção de tratamento. Resultados: A proporção de cura clínica e o índice global de resposta (completa e parcial) foram respectivamente de 46,7 por cento (IC 95 por cento:28,8-65,3) e 60,0 por cento (IC 95 por cento:40,7-76,7) no grupo tratado com mefloquina, e de 60,0 por cento (IC 95 por cento:40,7-76,7) e 63,3 por cento (IC 95 por cento:43,9-79,5) no outro grupo. Náuseas e vômitos, em geral de intensidade leve, foram os efeitos colaterais mais comuns no grupo tratado com mefloquina. No outro predominaram episódios de artralgia de leve intensidade. Conclusão: Se estudos posteriores confirmarem a equivalência em termos de resposta, pela facilidade de administração, maior aderência ao tratamento e toxicidade aceitável, a mefloquina poderá se constituir em uma alternativa aos antimoniais pentavalentes no tratamento da LTA

Teste de aglutinaçäo directa no sorodiagnóstico da leishmaniose visceral no estado do Pará / Direct agglutination test in the serodiagnosis of human visceral leishmaniases in the State of Pará, Brazil

The direct agglutination test (DAT) was evaluated for serodiagnosis of visceral leishmaniasis (VL) in human and canids (dogs and foxes Cerdocyon thous). The results were compared with those of the immunofluorescent antibody assay (IFAT) and enzyme-linked immunosorbent assay (ELISA). The sera used were from: humans (303): confirmed VL (16), suspected VL (65), other conditions (102), negative controls (15) and individuals from an endemic area (105); dogs (82): from an endemic area (68), Salvaterra/Marajó/Pará (21 of which were parasitologically positive), and negative controls (14), from Belém; foxes (9): caught on Marajó Island. Antigens for DAT were prepared from promastigots of L. (L.) donovani, L. (L.) chagasi. Antigens used in ELISA and IFAT were prepared from promastigotes (soluble antigen) and amastigotes respectively of L. (L.) chagasi. In humans, the specificity and sensitivity of DAT using L. (L.) donovani were high (98.4 per cent and 100 per cent respectively) and comparable to that of IFAT (97.5 per cent and 100 per cent). ELISA was less specific (84.8 per cent) although similarly sensitive (100 per cent). In dogs, DAT was more specific using L. (L.) donovani as antigen than using L. (L.) chagasi. However, both DAT and ELISA were less sensitive (both 71.4 per cent) than IFAT (100 per cent). This difference was reflected in the results from endemic dogs, 87 per centof which were positive by IFAT but only 54 per cent by ELISA and 49 per cent by DAT. Similarly, all 9 fox sera were positive by IFAT, 7 of 9 (78 per cent) by ELISA but none by DAT. In conclusion, DAT using L. (L.) donovani antigen can provide a useful test for human VL; utilization on a large scale would be possible with a suitable reference laboratory to monitor antigen quality. However, DAT appears less useful for canine studies, as it was less sensitive than ELISA and especially IFAT in detecting canine infection.

Histopatologia da forma localizada de leishmaniose cutanea por Leishmania (Leishmania) amazonensis / Histopathology of the localized form of cutaneous leishmaniosis due to Leishmania (Leishmania) amazonensis

Sao descritas as alteracoes microscopicas presentes na forma localizada (ulcerada) da Leishmaniose cutanea produzida por Leishmania (Leishmania) amazonensis. Nesse tipo de manifestacao, menos conhecido do que a forma anergica ou difusa devida ao mesmo agente, as lesoes sao clinicamente identicas as de leishmaniose cutanea causada por especies outras de Leishmania, pertencentes ao subgenero Viannia. Na infeccao localizada por L. (L.) amazonensis, entretanto, ha um aspecto peculiar, so recentemente conhecido, ou seja, cerca de 50 por cento dos individuos atingidos nao reagem ao teste de Montenegro. A principal caracteristica histologica observada foi a acumulacao na derme, quase sempre focal, de numerosos macrofagos contendo no citoplasma um grande vacuolo cheio de amastigotas....

Zigomicose nasofacial: relato de um caso do estado do Para, Brasil / Nasofacial zygomycosis: case report from Para, Brazil

Um caso de zigomicose nasofacial, causado por Conidiobolus coronatus, e descrito em paciente de 64 anos, do sexo feminino, procedente de Barcarena, Estado do Para. Trata-se de doenca rara na Regiao Norte do pais - a maioria dos casos brasileiros tem sido registrada em Estados da Regiao Nordeste -, e o achado confirma a ocorrencia do agente no Estado do Para. A resposta ao iodeto de potassio, droga administrada a paciente, logo apos a comprovacao do diagnostico pelo isolamento do fungo, foi boa, com resolucao parcial das lesoes em algumas semanas. A paciente continua ainda em tratamento, tendo-se associado o itraconazol ao iodeto.

Avaliação de três esquemas terapêuticos com o antimoniato de N-metil-glucamina no tratamento da leishmaniose visceral no estado do Pará, Brasil / Evaluation of 3 therapeutic schedules with N-methyl-glucamine antimonate in the treatment of visceral leishmaniasis in the state of Para, Brazil

We have evaluated, in a retrospective manner, three chemotherapeutic schemes with meglumine antomoniate (Glucantime) use in the treatment of 43 autochthonous cases of visceral leishmaniasis in children in the age-group of 1-12 years old, during the period 1985-1990. Of the 43 cases, 28 (group A) were treated with 40mg/SbV/kg given IV at intervals of 48 hours, in courses of 15 applications (scheme I); 8 (group B) were treated with 40 mg/SbV/kg given IV daily during 15 days (scheme II), and 7 (group C) were treated with 20 mg/SbV/kg given IV daily during 15 days (scheme III). With the criteria for cure based essentially on clinical examination, we admitted that the scheme III would be the preferred for these reasons: a) it produces the same cure-rate as those schemes which use double this dosage, b) in relation to positive results it is less expensive, c) the scheme can be used for more extended periods, with less risk of toxic effects, and d) there has till now been no evidence of the development of resistance to treatment using this scheme, at least in our particular area of study (Pará).

Leishmaniose cutânea experimental: III. Aspectos histopatológicos do comportamento evolutivo da lesäo cutânea produzida em Cebus apella (Primates: Cebidae) por Leishmania (Viannia) lainsoni, L. (V.) brasiliensis e L. (Leishmania) amazonensis / Experimental cutaneous leishmaniasis: III. Histophatological aspects of the evolutive behavior of the cutaneous lesion induced in Cebus apella (Primates: Cebidae) by Leishmania (Viannia) lainsoni, L. (V.) braziliensis and L. (Leishmania) amazonensis

Estudaram-se os aspectos histopatológicos relativos à evoluçäo da infecçäo experimental produzida em Cebus apella (Primates: Cebidae) por Leishmania (V.) lainsoni, L. (V.) braziliensis e L. (L.) amazonensis. O exame microscópico de biópsias seqüênciais, obtidas dos animais a intervalos definidos d etempo (a primeira, âs 48 ou 72 horas após a inoculaçäo, e as seguintes, a cada 30 dias), mostrou que o desenvolvimento das lesöes, independente da espécie de Leishmania inoculada, pass por uma seqüência de etapas a nível tecidual - 1) infiltrado inespecífico crônico; 2) nódulo macrofágico (com numerosos parasitas); 3) necrose das células parasitadas; 4) granuloma epitelióide; 5) absorçäo da área necrosada (às vezes formando granuloma de corpo estranho); 6) infiltrado inespecífico crônico residual); e 7) cicatrizaçäo - que representaria a formaçäo e a resoluçäo das lesöes. Discutiram-se também os prováveis mecanismso imunopatológicos que determinaram esta seqüência de eventos e sua possível semelhança com a evoluçäo das lesöes na leishmaniose tegumentar humana