Leishmania mexicana in Proechimys iheringi denigratus Moojen (Rodentia, Echimyidae) in a region endemic for American cutaneous leishmaniasis

Three isolates of Leishmania were recovered from five of 27 specimens of the rodent Proechimys iheringi denigratus Moojen captured near Três Braços in the Atlantic Forest region of Bahia, Brazil. Two of these isolates were recovered from hamsters inoculated with a pooled triturate of liver, spleen and skin tissue from apparently healthy P. i. denigratus. The third isolate was recovered from a triturate of only skin tissue from another. Metastasis was observed in the inoculated hamsters, the parasites grew abundantly in artificial media and a typical suprapylarial pattern of infection in Lutzomyia longipalpis was produced indicating that the parasites belong to the Leishmania mexicana complex. All isolates reacted with Leishmania mexicana mexicana and Leishmania mexicana amazonensis monoclonal antibodies. The isoenzyme analysis differentiated these isolates from standard isolates of L. m. mexicana, L. m. amazonensis, L. m. aristedesi, L. m. pifanoi, L. m. garnhami and L. m. ssp.(Goiás-W. Barbosa). These isolates seem to be a subspecies of L. mexicana very closely related to L. m. amazonensis from which they differ by decreased electrophoretic mobility of GPI, PEP and ALAT. This is the first record of the isolation of a parasite of thegenus Leishmania in a rodent captured in the State of Bahia.

Studies on anti-component 5 antibodies in animals infected with Trypanosoma cruzi

A competitive antibody enzyme immunoassay, using a monoclonal antibody against the species-specific Trypanosoma crnzi antigen 5, was used to investigate the presence of anti-component 5 antibodies in sera of opossums, dogs, rabbits and rats infected with this parasite. The sera from 51 Venezuelan patients with Chagas’disease were also tested. About 90% of the infected subjects showed significant levels of anti-component 5 antibodies. Nevertheless, these antibodies were not detected in the sera of dogs, rats and opossums infected with T. cruzl Some sera from infected rabbits presented significant results but close to the limit ofpositivity ofthe test. These findings suggest that the immune response in animals naturally or experimentally infected with T. cruzi is different from that observed in human Chagas’disease.

Freqüência das infecções oculares por clamídia nos portadores de conjuntivite, em clínica particular de Uberaba, MG

Setecentos e oitenta pacientes com recidivas clínicas de infecções conjuntivais ou queixas persistentes de prurido, ardor, dor, lacrimejamento e hiperemia, foram submetidos ao raspado conjuntival com citologia e pesquisa de inclusões. Destes 247(31,7%) apresentaram inclusões citoplasmáticas; 235 pacientes foram, também, submetidos a coloração com anticorpo monoclonal fluorescente (imunofluorescência direta - DFA) com 90 (38,3%) casos positivos. Discute-se também, a importância do quadro clinico e dos métodos laboratoriais (coloração com anticorpo monoclonal fluorescente e pesquisa de inclusões citoplasmáticas) no diagnóstico. Os pacientes fazem parte de clientela de clínica particular e tem nível sócio-econômico de médio a alto.

Human chronic chagasic myocarditis: quantitative study of CD4 + and CD8 + lymphocytes in the inflammatory infiltrate

Myocardialexsudate CD4+ andCD8+ lymphocytes were counted in transmural left ventricular free wall frozen sections taken from 10 necropsied chronic cardiac chagasic patients. The cells were labeled with monoclonal antibodies using a streptavidin-biotin technique. We counted: 1) lymphocytes in the total exsudate (LTE) and, separately, 2) the lymphocytes touching orvery near to my oc ells (LTVNM). Lymphocytes were considered very near whenever their own nuclear shortest nuclear diameter was larger than their distance from myocells. CD8+ lymphocytes were more numerous than CD4+ lymphocytes, especially among the LTVNM. The LTE CD4/CD8 ratio was 0,37 ± 0,20, but the LTVNM CD4/CD8 ratio was smaller (0,23 ± 0,11). Among theLTE, 34 ± 11% ofCD8+ (against24 + 12% of CD4+) were LTVNM. All these differences were statistically significant. Both subtypes ofT-lymphocytes were found to have an intimate relationship with both ruptured and unruptured myocells, and parasites were not seen. These findings are in accordance with the idea that the myocardial cell lesions in the cardiac form of human Chagas' disease are mediated mainly by T- cytotoxic lymphocytes.

Spontaneous regional heading of extensive skin lesions in diffuse cutaneous leishmaniasis (DCL)

The authors report a case of diffuse cutaneous leishmaniasis, with longstanding evolution and presenting with diffuse infiltrated lesions rich in amastigotes in the absence of mucosal involvement. In situ characterization with monoclonal antibodies revealed Leishmania amazonensis. Large regional lesions have presented spontaneous healing without specific therapy. Considering that DCL presents with a defect in the cellular immune response, thisfact demonstrate that this patient may develop a regional cellular immune response enough to destroy the parasites and to produce clearing of some lesions.

Confocal fluorescence microscopy: a powerful tool in the study of Chagas' disease

Confocal scanning fluorescence microscopy has become widely used in cell biology and pathology. In conjunction with monoclonal antibodies it may turn out to be a powerful diagnostic tool that also enables detailed studies of tissue forms of Trypanosoma cruzi.

Avaliação de parâmetros para o diagnóstico laboratorial de infecção genital feminina pela Chlamydia trachomatis

Foram examinadas prospectivamente189 amostras cervicais de mulheres sintomáticas e assintomáticas. Foram colhidas 2 amostras do canal endocervical, das quais uma foi examinada pela reação de imunofluorescência direta (IFD) com anticorpo monoclonal (MicroTrak), para verificação da adequação das amostras. A segunda amostra foi inoculada em cultura de células McCoy. Uma terceira amostra foi coletada para pesquisa de anticorpos das classes IgG e IgA. A Chlamydia trachomatis foi isolada de 14/166 (8,4%) das mulheres com sintomas e de 3/23 (13%) daquelas sem sintomas. Observamos que as 152 mulheres do grupo sintomático, com cultura negativa, possuiam sintomas equivalentes. Em relação ao número de células epiteliais, verificou-se que 13 das 17 (76,5%) amostras endocervicais positivas pela cultura e pela IFD, todas apresentavam mais de 5 células. Tomando-se como critério de positividade títulos ³ 1:8, foram detectados anticorpos das classes IgG e/ou IgA específicos para C. trachomatis em 11/189 (64,7%) das 17 mulheres com cultura positiva. Conclusões: a) não existe sintoma que seja específico de infecção por clamídia (p > 0,05); b) a quantidade de células epiteliais representariam fator de interferência na positividade da cultura, sendo, portanto, variáveis dependentes (p < 0,001); c) a pesquisa de anticorpos na cérvice não poderia ser utilizada como diagnóstico alternativo, pois a sua detecção depende da fase evolutiva da infecção e da resposta imunitária individual.

Avaliação da resposta imune celular em pacientes com candidíase recorrente

A candidíase recorrente cutânea ou mucosa é caracterizada pela ocorrência de, no mínimo, 4 episódios de candidíase no período de um ano. Não são conhecidos os fatores que levam à recorrência desta infecção. O presente estudo avaliou a resposta linfoproliferativa e a produção de IFN-g de pacientes com candidíase recorrente. Os índices de estimulação da resposta linfoproliferativa em culturas de células de pacientes com candidíase recorrente estimuladas com antígeno de Candida albicans, PPD e TT foram respectivamente de 6±8, 17±20 e 65±30. A adição de anticorpo monoclonal anti-IL-10 às culturas de células de 6 pacientes aumentou a resposta linfoproliferativa de 735±415 para 4143±1746 cpm. A produção de IFN-g em culturas de células estimuladas com antígeno de Candida, foi 162±345pg/ml. Pacientes com candidíase recorrente apresentam uma deficiência na resposta linfoproliferativa e na produção de IFN-g, podendo a resposta imune celular ao antígeno de Candida ser restaurada parcialmente através da neutralização da IL-10 in vitro.

Clinical, epidemiological and laboratory aspects of patients with American cutaneous leishmaniasis in the State of Pernambuco

The diagnosis for American cutaneous leishmaniasis is based on an association of clinical, epidemiological and laboratory characteristics. The present study identified the circulating species of Leishmania in the State of Pernambuco, described its clinical-epidemiological characteristics and diagnosed the disease. Nineteen patients presenting active lesions who had been diagnosed through clinical evaluation and laboratory tests were selected. The tests included direct investigation, in vitro culturing, Montenegro skin test, indirect immunofluorescence and polymerase chain reaction. The Montenegro Skin Test showed positive results in 89% of the patients; indirect immunofluorescence, in 79%; direct investigation, in 58%; and polymerase chain reaction in 75%. Seven Leishmania (Viannia) braziliensis samples were isolated from these patients and were characterized by means of specific monoclonal antibodies. These data confirm that a combination of different diagnosis techniques is needed in order to obtain efficient results and that, so far, Leishmania (Viannia) braziliensis is the only species responsible for American cutaneous leishmaniasis infection in Pernambuco. Thus, it is essential to identify the parasite species involved in cases of human disease in an endemic area in order to determine the clinical and epidemiological characteristics, especially with regard to diagnosis, therapy development and disease prognosis.

High molecular mass fraction in clinical isolates of Paracoccidioides brasiliensis

INTRODUCTION: Different serum levels of the IgG/IgE for Paracoccidioides brasiliensis high mass molecular (hMM) fraction (~366kDa) in the acute and chronic forms of the disease have been reported. Considering the nonexistence of hMM fraction investigation involving clinical isolates of P. brasiliensis, the present study aimed to investigate the presence of the hMM fraction (~366kDa) in cell free antigens (CFA) from P. brasiliensis clinical isolates. METHODS: CFA from 10 clinical isolates and a reference strain (Pb18) were submitted to SDS-polyacrylamide gel electrophoresis (SDS-PAGE) followed by gel image capturing and densitometer analysis. Additionally, CFA from 20 isolates and Pb18 were analyzed by capture ELISA (cELISA) using polyclonal (polAb) or monoclonal (mAb) antibodies to the hMM fraction. RESULTS: The presence of the hMM component was observed in CFA of all samples analyzed by SDS-PAGE/densitometry and by cELISA. In addition, Pearson's correlation test demonstrated stronger coefficients between hMM fraction levels using pAb and mAb (R = 0.853) in cELISA. CONCLUSIONS: The soluble hMM fraction was present in all the P. brasiliensis clinical isolates analyzed and the reference strain Pb18, which could be used as a source of this antigen. The work also introduces for first time, the cELISA method for P. brasiliensis hMM fraction detection. Analysis also suggests that detection is viable using polAb or mAb and this methodology may be useful for future investigation of the soluble hMM fraction (~366kDa) in sera from PCM patients.

First report of rabies infection in bats, Molossus molossus, Molossops neglectus and Myotis riparius in the city of São Paulo, State of São Paulo, southeastern Brazil

INTRODUCTION: This paper presents the first report of rabies in three bat species, Molossus molossus, Molossops neglectus and Myotis riparius in the city of São Paulo, Brazil. METHODS: Bats were diagnosed as positive for rabies using the fluorescent antibody test and mouse inoculation test. The isolates were characterized antigenically using a panel of eight monoclonal antibodies. The samples were also genetically analyzed by partial sequencing of the portion of nucleoprotein gene between positions 1157 and 1445nt. RESULTS: Analysis of the results verified that the sample isolated from the species M. molossus presented antigenic variant 6, while the other two samples showed a different profile from that established in the panel, one not previously reported in the literature. The results of genetic analysis revealed that the M. molossus sample segregated with Lasiurus sp. isolates, M. neglectus segregated with a subgroup of Eptesicus furinalis isolates and the Myotis riparius sample segregated with Myotis sp. isolates. CONCLUSIONS: The cases reported in this paper emphasize the need for clarification of the circumstances in which cases of rabies in wildlife occur, principally in urban areas.

Molecular characterization of rabies virus isolated from non-haematophagous bats in Brazil

INTRODUCTION: Rabies is an important zoonosis that causes thousands of deaths worldwide each year. Although the terrestrial cycle, mainly transmitted by dogs, is controlled in Brazil, the aerial cycle remains a serious public health issue, besides the economic problem. In the aerial cycle, the haematophagous bat Desmodus rotundus is the main source of infection, where several different species of non-haematophagous bats can be infected and can transmit the virus. METHODS: The aim of this work was to study the epidemiological pattern of rabies using antigenic characterization with monoclonal antibodies and genetic characterization by reverse-transcriptase polymerase chain reaction followed by sequencing and phylogenetic analysis of non-haematophagous bats' and herbivorous animals' central nervous system samples from the western region of the State of São Paulo, Brazil. RESULTS: From 27 samples, 3 antigenic variants were identified: AgV-3, AgV-4, and AgV-6; and from 29 samples, 5 different clusters were identified, all belonging to the rabies virus species. CONCLUSIONS: Although only non-haematophagous bats were evaluated in the studied region, the majority of samples were from antigenic and genetic variants related to haematophagous bats Desmodus rotundus. Samples from the same antigenic variant were segregated in more than one genetic cluster. This study demonstrated the diversity of rabies virus genetic lineages presented and circulating in non-haematophagous bats in the studied region.

Prevention of respiratory syncytial virus infections

Respiratory syncytial virus is the most important cause of viral lower respiratory illness in infants and children worldwide. By the age of 2 years, nearly every child has become infected with respiratory syncytial virus and re-infections are common throughout life. Most infections are mild and can be managed at home, but this virus causes serious diseases in preterm children, especially those with bronchopulmonary dysplasia. Respiratory syncytial virus has also been recognized as an important pathogen in people with immunossupressive and other underlying medical problems and institutionalizated elderly, causing thousands of hospitalizations and deaths every year. The burden of these infections makes the development of vaccines for respiratory syncytial virus highly desirable, but the insuccess of a respiratory syncytial virus formalin-inactivated vaccine hampered the progress in this field. To date, there is no vaccine available for preventing respiratory syncytial virus infections, however, in the last years, there has been much progress in the understanding of immunology and immunopathologic mechanisms of respiratory syncytial virus diseases, which has allowed the development of new strategies for passive and active prophylaxis. In this article, the author presents a review about novel approaches to the prevention of respiratory syncytial virus infections, such as: passive immunization with human polyclonal intravenous immune globulin and humanized monoclonal antibodies (both already licensed for use in premature infants and children with bronchopulmonary dysplasia), and many different vaccines that are potential candidates for active immunization against respiratory syncytial virus.

C-cells in colloid goiter

PURPOSE: The aim of this investigation was to quantitatively evaluate C-cells in colloid goiters, analyzing 36 thyroids that were obtained through thyroidectomy from 24 patients with goiter and 12 normal glands from adult patients without thyroid disease, which were used as the control group. MATERIAL AND METHODS: On average, 6 different thyroid areas were sampled and labeled by immunohistochemistry with a monoclonal anticalcitonin antibody, utilizing the avidin-biotin-peroxidase complex. C-cells were counted in fields measuring 1 square centimeter, and the mean number of cells per field was then calculated. Data were statistically analyzed using the Mann-Whitney test. RESULTS: In the colloid goiter group, the number of C-cells ranged from 0 to 23 per field, while in normal controls they ranged from 20 to 148 per field. CONCLUSIONS: These results demonstrate a significant decrease of C-cell number in the colloid goiter group compared with control group, indicating that the hyperplastic process is restricted to follicular cells, to the detriment of C-cells, which probably cease to receive trophic stimuli.

Interação entre especialidades: miocardiopatia dilatada e neoplasia de mama HER2 positiva

O progresso no conhecimento dos mecanismos da doença e suas potenciais possibilidades de tratamento, têm com o incremento da pesquisa básica, trazido a algumas situações inusitadas. Como quando algo observado em uma situação específica, definida na prática clínica, pode ser transportado para o laboratório, instigando a investigação de uma provável terapêutica em uma doença não relacionada e fazendo o caminho inverso da "bench-to-bedside". Nos últimos anos, o uso de um anticorpo monoclonal, o trastuzumabe, mostrou-se imprescindível no tratamento das neoplasias de mama com amplificação/superexpressão de HER2, com ganho de sobrevida significativo nos contextos adjuvante e terapêutico. A observação da ocorrência de cardiotoxicidade induzida pelo trastuzumabe, assim como a identificação dos mecanismos relacionados a esse efeito colateral, possibilitaram a pesquisa desses mesmos fatores na miocardiopatia dilatada, de uma forma muito interessante.