Leishmanicidal activity of Echinaster (Othilia) echinophorus crude extract

In this study, a methanolic extract from Echinaster (Othilia) echinophorus was evaluated for activity against Leishmania amazonensis. The extract showed activity against the promastigote and amastigote forms with IC50 values of 62.9 and 37.5 μg.mL-1 respectively. This extract showed a moderate toxicity on macrophages from BALB/c mice. A dose of 100 mg/kg/day was effective when administered during 15 days by intraperitoneal route to BALB/c mice infected experimentally.

Staphylococcus warneri meningitis in a patient with Strongyloides stercoralis hyperinfection and lymphoma: first report of a case

A case of meningitis due to Staphylococcus warneri in a patient with a hyperinfection with Strongyloides stercoralis possibly associated with rituximab treatment for mantel cell lymphoma is reported for the first time in the literature. The patient was a 59-year-old woman, with a 3-year history of an apparently well controlled lymphoma after treatment with chemotherapy-immunotherapy and then immunotherapy alone, and diagnosis of strongyloidiasis. Meningitis was diagnosed by cerebrospinal fluid culture and tested with an automated plate system. The patient was successfully treated with vancomycin; although fever and productive cough persisted. Severe gastrointestinal symptoms and pneumonia developed three weeks later. Hyperinfection syndrome by S. stercoralis was diagnosed, with abundant larvae in feces and expectoration.

Potential immunological markers for diagnosis and therapeutic assessment of toxocariasis

In human toxocariasis, there are few approaches using immunological markers for diagnosis and therapeutic assessment. An immunoblot (IB) assay using excretory-secretory Toxocara canis antigen was standardized for monitoring IgG, IgE and IgA antibodies in 27 children with toxocariasis (23 visceral, three mixed visceral and ocular, and one ocular form) for 22-116 months after chemotherapy. IB sensitivity was 100% for IgG antibodies to bands of molecular weight 29-38, 48-54, 95-116, 121-162, >205 kDa, 80.8% for IgE to 29-38, 48-54, 95-121, > 205 kDa, and 65.4% for IgA to 29-38, 48-54, 81-93 kDa. Candidates for diagnostic markers should be IgG antibodies to bands of low molecular weight (29-38 and 48-54 kDa). One group of patients presented the same antibody reactivity to all bands throughout the follow-up study; in the other group, antibodies decayed partially or completely to some or all bands, but these changes were not correlated with time after chemotherapy. Candidates for monitoring patients after chemotherapy may be IgG antibodies to > 205 kDa fractions, IgA to 29-38, 48-54, 81-93 kDa and IgE to 95-121 kDa. Further identification of antigen epitopes related to these markers will allow the development of sensitive and specific immunoassays for the diagnosis and therapeutic assessment of toxocariasis.

Evaluation of the ELISA-F29 test as an early marker of therapeutic efficacy in adults with chronic Chagas disease

This work compared the time at which negative seroconversion was detected by conventional serology (CS) and by the ELISA-F29 test on a cohort of chronic chagasic patients treated with nifurtimox or benznidazole. A retrospective study was performed using preserved serum from 66 asymptomatic chagasic adults under clinical supervision, and bi-annual serological examinations over a mean follow-up of 23 years. Twenty nine patients received trypanocide treatment and 37 remained untreated. The ELISA-F29 test used a recombinant antigen which was obtained by expressing the Trypanosoma cruzi flagellar calcium-binding protein gene in Escherichia coli. Among the untreated patients, 36 maintained CS titers. One patient showed a doubtful serology in some check-ups. ELISA-F29 showed constant reactivity in 35 out of 37 patients and was negative for the patient with fluctuating CS. The treated patients were divided into three groups according to the CS titers: in 13 they became negative; in 12 they decreased and in four they remained unchanged. ELISA-F29 was negative for the first two groups. The time at which negativization was detected was significantly lower for the ELISA-F29 test than for CS, 14.5 ± 5.7 and 22 ± 4.9 years respectively. Negative seroconversion was observed in treated patients only. The results obtained confirm that the ELISA-F29 test is useful as an early indicator of negative seroconversion in treated chronic patients.

RESISTANCE TO AMOXICILLIN, CLARITHROMYCIN AND CIPROFLOXACIN OF Helicobacter pylori ISOLATED FROM SOUTHERN BRAZIL PATIENTS

Introduction: Helicobacter pylori is a bacteria which infects half the world population and is an important cause of gastric cancer. The eradication therapy is not always effective because resistance to antimicrobials may occur. The aim of this study was to determine the susceptibility profile of H. pylori to amoxicillin, clarithromycin and ciprofloxacin in the population of Southern Brazil. Material and methods: Fifty four samples of H. pylori were evaluated. The antibiotics susceptibility was determined according to the guidelines of the British Society for Antimicrobial Chemotherapy and the Comité de l'Antibiogramme de la Société Française de Microbiologie. Results: Six (11.1%) H. pylori isolates were resistant to clarithromycin, one (1.9%) to amoxicillin and three (5.5%) to ciprofloxacin. These indices of resistance are considered satisfactory and show that all of these antibiotics can be used in the empirical therapy. Conclusion: The antibiotics amoxicillin and clarithromycin are still a good option for first line anti-H. pylori treatment in the population of Southern Brazil.

ANTHELMINTIC ACTIVITY OF LAPACHOL, β-LAPACHONE AND ITS DERIVATIVES AGAINST Toxocara canis LARVAE

Anthelmintics used for intestinal helminthiasis treatment are generally effective; however, their effectiveness in tissue parasitosis (i.e. visceral toxocariasis) is moderate. The aim of this study was to evaluate the in vitroactivity of lapachol, β-lapachone and phenazines in relation to the viability of Toxocara canis larvae. A concentration of 2 mg/mL (in duplicate) of the compounds was tested using microculture plates containing Toxocara canis larvae in an RPMI-1640 environment, incubated at 37 °C in 5% CO2 tension for 48 hours. In the 2 mg/mL concentration, four phenazines, lapachol and three of its derivatives presented a larvicide/larvistatic activity of 100%. Then, the minimum larvicide/larvistatic concentration (MLC) test was conducted. The compounds that presented the best results were nor-lapachol (MLC, 1 mg/mL), lapachol (MLC 0.5 mg/mL), β-lapachone, and β-C-allyl-lawsone (MLC, 0.25 mg/mL). The larvae exposed to the compounds, at best MLC with 100% in vitro activity larvicide, were inoculated into healthy BALB/c mice and were not capable of causing infection, confirming the larvicide potential in vitro of these compounds.

EXPERIMENTAL PARACOCCIDIOIDOMYCOSIS IN PREGNANT RATS

Paracoccidioidomycosis (PCM), caused by the dimorphic fungus Paracoccidioides brasiliensis (Pb), is the most prevalent systemic mycosis in Latin America. There are few reports in the literature about the disease damages during pregnancy and the consequences to the fetuses and breeding. This study evaluated the implications of PCM during pregnancy on offspring and mothers in Wistar rats. Groups of rats were submitted to systemic Pb infection, by intraperitoneal infusion, and mated 30 days after the infection date. Immediately after birth, rats and neonates were sacrificed to obtain organs for standard histological examination, morphometric analysis, fungi recovery by plating (CFU) and dosing of anti-Pb antibodies by ELISA. There were no stillbirths or miscarriages, however, the fetuses from infected pregnant rats had lower body and organ weight but the fertility rate was 100%. The largest number of CFU was recovered from the organ of pregnant rats, the pathological examination revealed more severe infection in the same group, further on the largest number of granulomas and fungal field. It can be concluded that the PCM was more severe in the group of pregnant rats, with implications to the weight of offspring.

Efecto de la temperatura de la piel en la leishmaniasis cutanea experimental

The literature on the thermosensitive properties of strains or species of Leishmania and of other miercorganisms is revised. Cutaneous or mucocutaneous strains that infect animais in the coldest areas of the skin or mucosa in general can not grow in tissue culture at 37°C or higher temperatures and their respiratory metabolism decreases at these temperatures. These facts suggest a thermosensitive event in some important metabolism phase of the organisme. The strains or species that are able to produce visceral leishmaniasis were probably originated from cutaneous strains after genetioally determined physiological adaptation, to warmer temperatures. These strains can not only visceralize in animais and man but will also grow in tissue culture at 36-37°C and the respiratory metabolism will be higher at such temperatures. There are reasons to believe that intermediate strains, i. e., with properties of both groupsí do exist. A thermosensitive physiological event is a more general phenomenon and examples of it can also be found in the fields of virology, bacteriology and mycology. It has practical applications since some of the diseases produced by these agents can be cured by treatments with heat or artificial fever. Experiments along these line were performed on hamsters with a Costa Rican strain of L. braziliensis as an experimental model. Even after intraperitoneal inoculation lesions appear in the nose, ears, paws and tail with a subcutaneous temperature bellow 33°C at 22-24°C. Healing of the lesión is accomplished by increasing room temperature. A good lesión is produced in the rump of the animal if the area is depilated (comercial cream depilatory) previously and the naked skin cooled artificially. Elevated temperature, or the growing back of the hair will tend to diminish or cure the lesion.

Infecção experimental do camundongo albino pelo Schistosoma mansoni. I - Estudo comparativo da eficácia de diferentes vias de infecção

O presente trabalho tem por objetivo o estudo da eficácia comparativa de diferentes vias de infecção na equistossomose experimental do camundongo albino. Foram utilizados trinta camundongos albinos de ambos os sexos, com idade de dois meses, infectados com cerca de cem cercárias cada um e sacrificados três meses após a infecção. As vias de penetração empregadas foram: oral, transcutânea (por submersão parcial, imersão apenas da cauda e/ou colocação de cercárias em área depilada do abdômen) e intraperitoneal. Os resultados obtidos demonstraram que a via mais eficaz foi transcutânea (sub-parcial), e que a maior mortalidade ocorreu no grupo infectado por via intraperitoneal.

Trypanosomiasis cruzi: a follow-up study of tissue reacting immunoglobulins in infected purebred pinscher dogs

Antibodies against striated muscle (cardiac and skeletal) were studied in serum samples from 36 purebred prepubertal Pinscher dogs (15 Controls without infection and 21 infected with Trypanosoma cruzi from 7 to 400 days after infection with 1000 trypomastigotes/gram body weight of the Colombiana strain by the intraperitoneal route). Although three different immunohistological pattems of tissue-reacting immunoglobulins were found their presence was not correlated with any peculiar characteristics or with the severity of the disease in each particular dog.

Kinetics of the cercaria-schistosomulum transformation in vivo

Sitice most studies on the cercaria-schistosomulum transformation have been carried out in vitro, the authors used the inoculation ofcercariae into the peritoneal cavity of mice tofollow the steps involved in this progressive adaptation of cercarie to the vertebmte host. The main conclusions were: 1. Most cercariae reach the schistosomular stage between 90-120 min after intraperitoneal inoculation. 2. Changes usuallystart with detachment of the tail followed by loss, rupture or changes of the glycocalix. 3. After 120 min most larvae loss their tails and present water sensitivity. 4. Acetabular grands depletion usually does not occur in cercaria-shistosomulum changes in the peritoneal cavity of mice. These steps differ in some way from those described in the kinetics of the in vitro observations performed by other investigators, and is more like those described in the penetration in the skin of living vertebrates.

Ensaio terapêutico com glucantime em sagüis (Callithrix jacchus) infectados com uma cepa de Leishmania donovani aparentemente resistente ao tratamento

Os autores relatam o resultado de um ensaio terapêutico em sagüis com uma cepa de Leishmania donovani isolada de um caso humano fatal de calazar, clinicamente resistente aos antimoniais (Glucantime e Pentostam), Anfotericina B ePentamidina. Os testes cutâneos realizados no paciente para avaliação da imunidade celular foram negativos à exceção do DNCB a 2%. Quatro sangüis adultos (Callithrix jacchus) foram inoculados por via intraperitoneal com uma suspensão deformas amastigotas de L. donovani. Duzentos e dez dias após, todos os animais mostravam formas amastigotas do protozoário, evidenciadas através de punção hepática por aspiração. Iniciou-se então um esquema terapêutico com glucantime (28 mgSb v/kg/dia) em três séries de 10 dias com cinco dias de intervalo entre elas em três dosprimatas,ficando o quarto animal como controle. Nos três animais tratados houve curaparasitológica da doença, o mesmo não ocorrehdo com o controle. O fato de a amostra de L. donovani ter sido, no paciente, resistente aos vários tratamentos e ter sido sensível em modelo experimental à terapêutica com glucantime, sugere a possibilidade de que fatores imunológicos do paciente possam ter contribuído para a evolução fatal da doença.

Estudo parasitológico e anátomo-patológico da fase aguda da doença de Chagas em cães inoculados com duas diferentes cepas do Trypanosoma cruzi

Cães jovens foram infectados com as cepas Y e CL do T. cruzi usando-se como inóculos 107 formas sangüíneas inoculadaspor via intraperitoneal e 2 x 10³ tripomastigotas metacíclicos obtidos do inseto vetor e inoculadospor via conjuntival. As cepas Ye CL induziram nos cães curvas deparasitemia totalmente distintas, confirmando dados parasitológicos obtidos em camundongos e coelhos. Com a cepa CL a parasitemia, com ambos os inóculos, foi gradualmente ascencional ao passo que com Y a parasitemia foi extremamente baixa, irregular e, com freqüência, subpatente. Com ambas as cepas o parasitismo e as lesões predominaram no miocárdio. Entretanto, com a cepa Y a miocardite foi sempre intensa desde as fases mais precoces da infecção, ao passo que com a cepa CL o processo inflamatório tomou-se acentuado somente a partir do 20.° dia. Freqüentemente a intensidade da miocardite observada em alguns animais não guardava relação com a parasitemia; em alguns cães com parasitemia subpatente, nos quais a infecção só foi diagnosticada pelo xenodiagnóstico, a intensidade da miocardite foi comparável àquela observada nos animais com parasitemia patente. Idêntica correlação também não foi assinalada em relação ao parasitismo tissular. Esses achados sugerem a participação de mecanismo imunológicos na gênese das lesões, ainda na fase aguda da infecção.

Infecção experimental de macacos cebus apella sp pelo Trypanosoma cruzi: avaliação clínica, eletrocardiqgráfica e anatomopatológica

Dos trinta e dois macacos capturados no interior do Estado de São Paulo e mantidos em laboratório em gaiolas individuais (24 a 25 C° e 70% de umidificação) após vários xenodiagnósticos negativos, 12 foram infectados por via intraperitoneal com diferentes cepas de Trypanosoma cruzi, cujas formas tripomastigotas injetadas variaram de 1.10(5) a 5.10(6) Os 20 macacos restantes foram mantidos como controle. No período de 1 a 6 anos tanto os animais inoculados como os não inoculados, foram submetidos axenodiagnóstico e teste soro lógico de aglutinação direta, exame clínico e o eletrocardiograma. Posteriormente os macacos foram necropsiados e todos os órgãos submetidos a exame macro e microscópico. O exame clínico e o eletrocardiograma não revelaram alterações. Dos 12 macacos infectados, 4 apresentaram evidências de infecção ao exame histopatológico: utn com formas amastigotas nos tecidos e 3 com miocardite crônica de grau leve. A parasitemiafoi comprovada em 66,66% dos animais na fase aguda e a sorologia em 91,66% na fase crônica. Concluiu-se que os macacos Cebus não expressaram susceptibilidade ao desenvolvimento das lesões que caracterizam a fase . crônica da doença de Chagas mas poderiam ser usados para manter as cepas de T. cruzi e estudos de pesquisa sorológico a longo termo.

Glucantime resistant Leishmania promastigotes are sensitive to pentostam

Growth inhibition in vitro tests were used to study the susceptibility to pentostam of different Leishmania strains involved in cutaneous and mucocutaneos leishmaniasis - one glucantime sensitive strain, three naturally glucantime resistant strains and one glucantime resistant line developed by in vitro drug exposure. Contrasting with the high degree , of glucantime resistance, all strains were sensitive to pentostam. These differences suggest that there is some relationship between chemical structure and in vitro activity for these antimonial compounds. These data justify a clinical re-evaluation to compare therapeutic efficacy of glucantime and pentostam in the treatment of leishmaniasis.