Association of oxamniquine praziquantel and clonazepam in experimental Schistosomiasis mansoni

The antischistosomal activity of clonazepam, when administered alone or in association with oxamniquine and praziquantel, was experimentally evaluated in mice infected with Schistosoma mansoni. The animals were treated 45 days post-infection with a single dose, by oral route, according to three treatment schedules: clonazepam 25 mg/kg and sacrificed 15 min, 1h or 4 h after treatment; clonazepam 1.0, 2.5 or 10.0 mg/kg and sacrificed 15 days post-treatment or with the dose of 10 mg/kg in association with oxamniquine 50 mg/kg or praziquantel 200 mg/kg, single dose, orally, every schedule with a control group. The efficacy of the drugs in vivo was assessed by means of worm counts and their distribution in mesentery and liver, mortality and oogram changes. In the chemotherapeutic schedules used, clonazepam did not present antischistosomal activity and the result of the association of this drug with oxamniquine or praziquantel was not significantly different from the one obtained when these two last drugs were administered alone. In the in vitro experiments, the worms exposed to 0.6 mg/mL clonazepam remained motionless throughout the 8-day-period of observation, without egg-laying, whereas the worms of the control group showed normal movements, egg-laying and hatching of miracidia on the last day of observation. The results obtained in the present study confirm the action of clonazepam on S. mansoni adult worm, in vitro, causing total paralysis of males and females. However, no additive or synergistic effects were observed when clonazepam were used in association with oxamniquine or praziquantel.

Detection of IgM antibodies to Schistosoma mansoni gut-associated antigens for the study of the dynamics of schistosomiasis transmission in an endemic area with low worm burden

Dados de prevalencia e incidencia da esquistossomose foram estimados, acompanhando-se um grupo de escolares residentes em area rural do municipio de Itariri (Sao Paulo, Brasil), por um periodo de 2 anos, com cinco inqueritos, um a cada semestre, realizados no primeiro semestre de cada ano entre marco e abril e no segundo, entre setembro e outubro. O hospedeiro intermediario do Schistosoma mansoni na area e a Biomphalaria tenagophila. A infeccao pelo S. mansoni foi determinada pelo metodo parasitologico de Kato-Katz, atraves do exame de tres laminas, e os resultados analisados comparativamente aos da reacao de imunofluorescencia para deteccao de anticorpos IgM (RIF-IgM). Foram encontrados nos cinco inqueritos indices de prevalencia de 8,6 por cento, 6,8 por cento, 9,9 por cento, 5,8 por cento e 17,2 por cento pelo metodo parasitologico...

Evoluçäo histológica em quatro casos de esquistossomose mansônica cutânea ectópica / Histological evolution in four cases of ectopic cutaneous mansonic schistosomiasis

Apresentaçäo de quatro casos de esquistossomose mansônica cutânea ectópica, observados em Pernambuco, onde a doença é freqüente. Na discussäo, os autores analisam a evoluçäo do quadro histológico, considerando semelhanças e diferenças, bem como reaçöes ao tratamento, comuns aos quatro pacientes

Stool examination and rectal biopsy in the diagnosis and evaluation of therapy of schistosomiasis mansoni

From each of a group of 217 adult males selected through enzyme-immunoassay or skin-test (Group A), six stool samples were examined by both the Lutz/Hoffman, Pons & Janer (Lutz/HPJ) and Kato/Katz methods. In addition, one oogram of the rectal mucosa was performed. By these methods, schistosomiasis was detected in 44.7%, 47.5% and 40.1% of the individuals respectively. To evaluate the methods in the assessment of cure, the last 40 patients from group A, treated with a single oral dose of oxamniquine at 15 mg/kg were followed up for six months (Group B). The criteria for parasitological cure included three stool examinations by Kato/Katz and Lutz/HPJ methods, one, three and six months post-treatment and a rectal biopsy between the fourth and sixth months post-treatment. The examinations were negative in 87.5%, 90% and 95% of the patients, respectively. The efficacy of oxamniquine was 82.5% when the three methods were considered together and there was no statistically significant difference between the sensitivity of the individual methods

Schistosoma mansoni: acquired immunity in mice after the use of oxamniquine at the evolutive skin and pulmonary phases

Camundongos infectados com 350 cercarias de Schistosoma mansoni (cepa LE) foram tratados com oxamniquina, em dose unica de 400 mg/kg, 24, 48, 72 e 96 horas apos a infeccao. Quarenta dias apos o tratamento, os animais foram submetidos a uma infeccao desafio com 80 cercarias, atraves da pele abdominal e da orelha. O numero de vermes imaturos nos grupos de animais tratados 24 e 96 horas apos a primeira infeccao foi menor do que no grupo controle, evidenciando que a morte de esquistossomulos por quimioterapia, durante as fases da pele e do pulmao, causa um estado de resistencia adquirida.

ELISA detection of specific circulating antibodies against Schistosoma mansoni in mice after treatment with oxamniquine

Mice infected with 80 cercariae of Schistosoma mansoni treated with a single oral dose of oxamnique (400 mg/kg) 65 days after infection. Groups of 8-12 animals were sacrificed approximately 2 weeks after treatment and then at montly intervals. The sera obtained were evaluated for S. mansoni antibodies by enzyme-linked immunosorbeent assay (ELISA) at 1:200 dilution. Worms could not be recovered on days 14, 28, 58, 90, 119, 154 and 180 after treatment, indicating the efficacy of the chemotherapy. When performed with different antigens obtained from several stages in the life cycle of S. mansoni, i.e., soluble egg antigen, adult worm tegument, cercaria antigen, schistosomule tegument and adult worm (10 *g antigen/ml), the ELISA showed a decrease in specific antibody levels as a function of time after treatment starting on day 58, reaching levels close to control (noninfected untreated) in most animals 120 days after treatment. Purified antigens from the adult worm and the schistosomule tegument appear to be promising for use in clinical studies evaluating schistosomiasis after drug treatment

Tratamento da esquistossomose mansônica por meio da associaçäo de oxamniquine com praziquatel. II - Observaçoes experimentais relativas à fase patente / Treatment of schistosomiasis mansoni with contamination oxamniquine and praziquantel. II - Experimental observations during the patent phase

Desejando verificar a eficácia da associaçäo de oxamniquine com praziquantel no tratamento da esquistossomose mansônica experimental, durante o período patente da infecçäo, os autores infectaram camundongos e compuseram os quatro grupos adiante especificados, para possibilitar procedimentos diversos, conforme os esquemas estipulados, havendo sempre administraçäo de dose única pela via oral: I - oxamniquine (50 mg/Kg); II - praziquantel (75 mg/Kg_; III - associaçäo de oxamniquine (50 mg/Kg) e praziquantel (75 mg/Kg); IV - controle. A verificaçäo da eficácia foi efetuada por meio de oogramas, com estudo e classificaçäo evolutiva dos ovos observados em fragmento do intestino delgado e, também, pela perfusäo do sistema venoso porta, para recuperaçäo dos vermes. Nos animais dos grupos I e II os fármacos tiveram açäo parcial, enquanto que nos camundongos do III ficou evidente o sinergismo, tornando-se justificavel a experimentaçäo clínica da associaçäo de oxamniquine com praziquantel, no tratamento dos casos humanos