Memórias do Instituto Oswaldo Cruz, Volume: 84 Supplement 1, Published: 1989
  • Foreword

    Katz, Naftale
  • Contrasts in the control of schistosomiasis

    Mott, Kenneth E.
  • A new approach to the treatment of acute schistosomiasis

    Lambertucci, J. R.
  • The immune-dependence of chemotherapy in experimental schistosomiasis

    Doenhoff, M. J.

    Abstract in English:

    Experimental evidence indicates that immune effector mechanisms can enhance the activity of schistosomicidal drugs. Praziquantel, oxamniquine, hycanthone and antimony were less effective against Schistosoma mansoni infections in mice immunosuppressed by T cell-deprivation, than against comparable infection in normal mice. The schistosomicidal activities of praziquantel, oxamniquine and antimony have been experimentally enhanced by the synergistic action of immune sera. In passive serum transfer experiments a s. mansoni antigen of Mr 27 kD with non-specific esterase activity was identified as a potentially sensitive target for the antibodies that interact with praziquantel. Indirect immunofluorescence indicated that this antigen was exposed on the worm surface as a result of praziquantel treatment.
  • Resistance of schistosomes to hycanthone and oxamniquine

    Cioli, Donato; Pica-Mattoccia, Livia; Archer, Sydney

    Abstract in English:

    Genetic crosses between phenotypically resistant and sensitive schistosomes demonstrated that resistance to hycanthone and oxamniquine behaves like a recessive trait, thus suggesting that resistance is due to the lack of some factor. We hypothesized that, in order to kill schistosomes, hycanthone and oxamniquine need to be converted into an active metabolite by some parasite enzyme wich, if inactive, results in drug resistance. Esterification of the drugs seemed to be the most likely event as it would lead to the production of an alkylating agent upon dissociation of the ester. An artificial ester of hycanthone was indeed active even in resistant worms, thus indirectly supporting our hypothesis. In addition, several lines of evidence demonstrated that exposure to hycanthone and oxamniquine results in alkylation of worm macromolecules. Thus, radioactive drugs formed covalent bonds with the DNA of sensitive (but not of resistant) schistosomes; an antiserum raised against hycanthone detected the presence of the drug in the purified DNA fraction of sensitive (but not of resistant) schistosomes; a drug-DNA adduct was isolated from hycanthone-treated worms and fully characterized as hycanthone-deoxyguanosine.
  • Alterações pulmonares associadas à esquistossomose mansoni

    Pedroso, Enio Roberto Pietra
  • Evolution and involution of hepatosplenic schistosomiasis

    Andrade, Zilton A.
  • Plantas empregadas como moluscicidas: uma visão crítica

    Jurberg, Pedro; Vasconcellos, Maurício Carvalho de; Mendes, Nelymar Martineli
  • Educação em saúde e esquistossomose: breve retrospectiva e uma proposta

    Schall, Virgínia Torres
  • Controle da esquistossomose no Brasil

    Silveira, Antônio Carlos

    Abstract in Portuguese:

    A extensa área em que há transmissão de esquistossomose (11% do território do país) e o fato de que a distribuição é sempre focal, dependente de condições locais, faz com que o controle seja metodológica e operacionalmente difícil. Desde o ano de 1976, com o Programa Especial de Controle da Esquistossomose (PECE), tem sido cumpridas atividades regulares, desde então sistematizadas em um programa vertical, que assim se manterá até que se alcance taxas de prevalência iguais ou inferiores a 5% em exames coproscópicos, rotineiramente realizados sob a forma de inquéritos que orientam o tratamento humano. A partir daí, os serviços permanentes de saúde deverão assumir as ações de controle. O uso de moluscicidas vem sendo racionalizado, a partir de uma melhor definição dos criadouros de importância epidemiológica. O saneamento e as atividades de educação em áreas localizadas, e nos limites dos recursos disponíveis, são ações complementares algumas vezes, desenvolvidas, em caráter até aqui mais ou menos esporádico. Os resultados colhidos indicam claramente a redução do número de casos de forma grave da doença, e a redução da morbidade, quando examinados os dados a um maior nível de agregação.

    Abstract in English:

    The great area with transmission of schistosomiasis in Brazil (11% of the hole country) associated to the focal distribution of the helminthiasis makes the disease control a difficult goal, not only methodologically but also in terms of operation. Since 1976, year when the Special Programme of Schistosomiasis Control was begun, it has been possible to devellop regular activities of control. Since then, these activities are conducted in a vertical programme, which is being mantained till it will be possible to get to a prevalence of five percent or under this value. The regular checking of prevalence is made through routine screening works by using stools exams. This works gives the orientation to the activity of cases treatment. From this point, is expected that control activities be conducted by permanent health services. Using of moluscocides is being controlled, so that it can be based in accurated epidemiological criteria. Environmental management and education activities in special areas are being conducted with availlable resources. The results obtained demonstrate that a reduction of cases with the malignant evolution of the disease and also of the morbidity of schistosomiasis is being obtained, at least if we consider the available data in a more aggreagate form.
  • Epidemiology and control of schistosomiasis in the Philippines: progress report as of 1987

    Blas, Bayani L.; Velasco, Perla F.; Aliaiy, Ofélia B.; Erce, Edgardo S.; Basas, José C.; Bautista, Edgardo S.
  • Control of schistosomiasis in the Gezira

    El Gaddal, A. A.

    Abstract in English:

    For the control of schistosomiasis in irrigated agricultural schemes, the inhabitants must have: 1) Enough potable water. 2) Latrines. 3) Proprer health education to motivate the community to participate in the control. 4) Proper diagnostic facilities. 5) Proper availabel chemotherapy. 6) Focal mullusciciding. 7) If possible trial of biological and environmental methods control. Following the above methods, we could reduce the prevalence of schistosomiasis from over 50% to about 13%. The important achievement, is the improvement of the health of the community; therefore more production and reduced morbidity and mortality.
  • A questão do social na epidemiologia e controle da esquistossomose mansonica

    Loureiro, Sebastião
  • The control of schistosomiasis: epidemiological aspects of reinfection

    Sturrock, R. F.
  • Alguns aspectos da genética das bionfalárias

    Simões, Luiz Carlos Gomes
  • Estratégia competitiva entre Biomphalaria glabrata e Biomphalaria tenagophila: estudos de laboratório

    Santos, Mairy Barbosa Loureiro dos; Freitas, José Rabelo de; Alves, Edirce de Souza Resende; Rocha, Luiz Antônio

    Abstract in English:

    Observation about conhabitation among B. glabrata and B. tenagophila revealed a greater vulnerability of B. tenagophila population during the process of competition when its density was severaly decreased in 12 trials, moderate in 2 trials. It was higher than B. glabrata in only one trial. Some snail water chemical parameters analysed such as pH, alkalinity, conductivity and oxygen dissolve, an the viability rate of batch of eggs didn't give subsidy to explain the competition mechanism. The newly-born survival, in the situation of cohabitation, was low for both species. This reveals the existence of intra and interspecific competitive interacition. The fertility rate reduction of B. tenagophila during the cohabitation was considered as a cause of its exlusion. One of the factors that seems to have influenced the fertility rate was a possible wrong crossing.
  • Schistosoma mansoni surface proteins

    Simpson, Andrew J. G.; Ali, Pirlanta Omer; Meadows, Helen M.; Jeffs, Simon A.; Hagan, Paul; Smithers, S. Ron
  • Experimental animal models in vaccination against schistosomiasis

    Mclaren, Diane J.
  • Regulation of gene expression in the Schistosoma mansoni female

    Rumjanek, Franklin David
  • Effects of irradiation and tunicamycin on the surface glycoproteins Schistosoma mansoni

    Kusel, J. R.; Wales, A.; Vieira, L.; Wu, K-Y

    Abstract in English:

    The cercarial glycocalyx and schistosomulum surface contains a number of glycoproteins which are expressed in very variable amounts within a parasite population. Tunicamycin inhibits glycoprotein synthesis of schistosomula if the parasites are incubated for 24hr with the drug (10µg ml[raised to the power of -1]). An unexpected increase in lectin binding to the parasite surface was observed but no other changes were detected. Schistosomula treated in this way did not develop in the host past the lung stage. Ultraviolet irradiation (400µW min cm[raised to the power of-2]) also inhibited glycoprotein synthesis. Synthesis of other proteins, and in particular heat shock proteins, were also inhibited. Sera from mice (NIH strain) infected with irradiated cercariae contained antibodies which bound to normal schistosomula with lower affinity than to irradiated parasites. This is evidence that irradiation modifies the surface and secreted glycoproteins of schistosomula, so they are processed in a different way to normal glycoproteins by the host's immune system. The effects of irradiation on heat shock protein synthesis may allow the parasite to release a variety of proteins and glycoproteins in abnormal conformations. This may explain the enhanced immunogenicity of irradiated cercariae.
  • Molecular and biochemical studies of the cercarial proteinase of Schistosoma mansoni

    McKerrow, James H.
Instituto Oswaldo Cruz, Ministério da Saúde Av. Brasil, 4365 - Pavilhão Mourisco, Manguinhos, 21040-900 Rio de Janeiro RJ Brazil, Tel.: (55 21) 2562-1222, Fax: (55 21) 2562 1220 - Rio de Janeiro - RJ - Brazil