Estudio clínico, laparoscópico e histológico en 60 pacientes con esquistosomiasis mansoni / Clinical, laparoscopic and histologic study in 60 patients with schistosomiasis mansoni

Se estudiaron 60 pacientes procedentes del continente africano a los que se les diagnosticó esquistosomiasis mansoni. Se realizó estudio coproparasitológico por la técnica de Knight y se demostró la presencia de huevos del parásito. El estudio hematológico mostró eosinofilia y el del perfil hepático resultó normal. Para la administración del tratamiento se formaron 3 grupos que recibieron diferentes drogas. A todos los casos se les realizó estudio laparoscópico y biopsia hepática, a su ingreso y al año posterior al tratamiento. El Praziquantel fue efectivo en el 95% de los casos, el Oxamniquine en el 75% y el Etrenol en el 55

Tratamento em massa como medida de controle da esquistossomose no Brasil

Apóss considerqçöes acerca da situaçäo epidemiológica da esquistossomose mansônica no Brasisl e dos principais dados relativos as drogas esquistossomicidas em uso atualmetne, säo revistos os aspectos mais relevantes com relaçäo ao uso da quimioterapis em massa, como forma de controle dessa endemia

Resistance of schistosomes to hycanthone and oxamniquine

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.

Efeito da quimioterapia sobre os ovos do Schistosoma mansoni / Effect of chemotherapy on the Schistosoma mansoni eggs

A administraçäo de praziquantel a camundongos infectados pelo Schistosoma mansoni(50 cercarias/8 semanas) causou necrose de coagulaçäo e/ou lítica, e por vezes calcificaçäo dos miracídios nos tecidos a partir do 4§ dia do início do tratamento. A administraçäo conjugada de oxamniquine/hycanthone, embora muito efetiva para eliminar os vermes adultos, näo teve açäo sobre os miracídios no interior dos granulomas, tendo os testes de eclosäo sido positivos até o 15§ dia após o tratamento curativo. A açäo do praziquantel sobre os ovos do S. mansoni pode ter repercussäo sorológica ou patogênica, facilitando uma mais rápida reabsorçäo dos granulomas pelos tecidos do hospedeiro

Hycanthone in the treatment of Egyptian bilharzial patients

Hycanthone has a schistomicidal effect against S. haematobium and S. mansoni present singly or combined in the patient. It is effective in all age groups but better in the old and adults than in children and better in females than in males. It gave a cure rate of 60.6% after single intramuscular dose of 3 mg/kg body weight .A Second dose after three months gave 94.4% cure rate and a third injection after further two months gave 100% cure rate, So, the drug should not be used in the treatment of bilharziasis as a single dose course

Regeneracao hepatica pos-hepatectomia parcial em ratos com fibrose esquistossomotica, antes e apos o tratamento medicamentoso. / Liver regeneration after partial hepatectomy in rats with schistosomotic fibrosis, before and after drug therapy

A regeneracao hepatica pos-hepatectomia parcial em ratos albinos com fibrose esquistossomotica apos o tratamento medicamentoso da esquistossomose, estudada atraves da cariometria dos hepatocitos e contagem de figuras de mitose e hepatocitos binucleados em 45 ratos albinos distribuidos em dois grupos: Grupo A: 29 ratos, 15 machos e 14 femeas, infectados no 3o mes de vida com uma carga de 400 cercarias de S. mansoni por animal e tratados com uma dose unica de 15 mg/kg de hycanthone por via intraperitoneal, seis meses apos a infeccao e submetidos a hepatectomia parcial no 13o mes de vida e avaliada a regeneracao hepatica 48 horas apos a hepatectomia; Grupo B: 16 ratos, 10 machos e seis femeas, sem infeccao, que receberam hycanthone em dose unica de 15 mg/kg por via intraperitoneal no 9o mes de vida e quatro meses apos foram submetidos a hepatectomia parcial, sendo os sobreviventes sacrificados 48 horas apos a intervencao. Os resultados obtidos mostram com uma confianca de 5o que ocorreu regeneracao hepatica poshepatectomia parcial em ratos com fibrose esquistossomotica, apos o tratamento medicamentoso, de forma semelhante aos animais normais com relacao aos parametros cariometria dos hepatocitos binucleados

Comparative toxicological study of some antibilharzial drugs

The data obtained in this work could be summarized as follows: 1. The LD 50 of tartar emetic was 49/kg, it produced a significant reduction of haemoglobin content and haematocrite value. It was the most toxic drug to the heart and lungs. Pharmacological studies showed that it produced direct depression on the isolated rabbits, heart, a perasympathomimetic effect manifested on isolated rabbits, intestine and blood pressure of anaesthetized dogs. 2. The LD 50 of astiban was 290 mg/kg. The results of subacute toxicity tests were similar to those obtained with tartar emetic but it was devoid of any toxic effect on heart. Pharmacological studies showed that it produced parasyupathomimetic effect on isolated rabbit's heart. 3. LD 50 of Hycanthone was 57 mg/ kg. No effect on the blood picture of rats was observed it was more toxic to the liver. It produced direct cardiac inhibition on the isolated rabbit's hearts, parasympathomimetic effect on the isolated rabbit's intestine and blood pressure of dog. 4. LD 50 of niridazole was 990 mg/ kg. The results of subacute toxicity tests were similar to those obtained with hycanthone. It is more toxic to brain it produced direct cardiac inhibition on the rabbit's heart and hypotension in dog