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Biomedical subjects

P L Pinto

Publications and source records attributed to P L Pinto.

At least 37 records · Page 2Linked to original sources
PubMedDate not supplied

[Eventual effect of artemisinine on the experimental infection of mice by Toxoplasma gondii].

Because of taxonomic similarities to previous data found in the literature, and with the aim of improving treatment of toxoplasmosis, we considered it of interest to assay artemisinin, an effective anti-malarial agent, for the treatment of experimental infection in mice by Toxoplasma gondii. Different amounts of the anti-parasitic agent were administered, including after previous contact in vitro with toxoplasma and stimulated macrophage production. With the methodology used artemisinin was not effective. Suggestions for further studies are made.

Animals↗
PubMedDate not supplied

[The use of sodium azide as a fecal preservative for studying the eggs of Schistosoma mansoni and of other helminths by the Kato-Katz method: a study in an endemic area].

In two aliquots of 208 samples of stool, tests have been made by the Kato-Katz method, one being made after the use of 0.2mg of sodic azide for 200mg, and the other without the aforesaid conservant. The resulted percentages with or without the conservant were, respectively, for Ancylostomideos: 12.5 and 25.9; for Ascaris lumbricoides: 71.6 and 72.5; for Schistosoma mansoni: 7.6 and 17.7, and for Trichuris trichiura: 86 and 85. The count of the eggs with and without the conservant was, respectively, 264 and 539 for Ancylostomideos, 13186 and 33751 for A. lumbricoides, 55.5 and 63.5 for S. mansoni, and 1345 and 2068 for T. trichiura. The authors did not confirm the advantage of using sodic azide for study in endemic areas. They suggest that the exsiccation of the stool and the low intensity of infections can explain the unfavourable results of the present clinical trial.

Animals↗
PubMedDate not supplied

Life cycle of Trypanosoma cruzi (Y strain) in mice.

Since 1958, we have studied experimental Chagas' disease (CD) by subcutaneous inoculation of 1,000 blood forms of Trypanosoma cruzi (Y strain) in Balb/C. mice. Evolution of parasitemia remained constant, beginning on the 5th and 6th day of the disease, increasing progressively, achieving a maximum on about the 30th day. After another month, only a few forms were present, and they disappeared from the circulation after the third month, as determined from direct examination of slides and the use of a Neubauer Counting Chamber. These events coincided with the appearance of amastigote nests in the tissues (especially the cardiac ones), starting the first week, and following the Gauss parasitemia curve, but they were not in parallel until the chronic stage. In 1997, we began to note the following changes: Parasites appeared in the circulation during the first week and disappeared starting on the 7th day, and there was a coincident absence of the amastigote nests in the tissues. A careful study verified that young forms in the evolutionary cycle of T. cruzi (epi + amastigotes) began to appear alongside the trypomastigotes in the circulation on the 5th and 7th post-inoculation day. At the same time, rounded, oval, and spindle shapes were seen circulating through the capillaries and sinusoids of the tissues, principally of the hematopoietic organs. Stasis occurs because the diameter of the circulating parasites is greater than the vessels, and this makes them more visible. Examination of the sternal bone marrow revealed young cells with elongated forms and others truncated in the shape of a "C" occupying the internal surface of the blood cells that had empty central portions (erythrocytes?). We hypothesize that there could be a loss of virulence or mutation of the Y strain of Trypanosoma cruzi.

Animals↗
PubMedDate not supplied

[Trypanosoma cruzi in the milk of women with chronic Chagas disease].

Breast milk secretion is one of the possible alternative mechanisms of transmission of the parasitosis caused by Trypanosoma cruzi, but it is still needed to define its importance in terms of public health. On this aim we searched for the presence of this protozoal organism in the colostrum and breast milk of 40 women with Chagas' disease, through direct observation, culture and inoculation. We never found parasite; perhaps it might be possible with the use of more efficient procedures and a larger number of cases.

Animals↗
PubMedDate not supplied

[Evaluation of the therapeutic activity of itraconazole in chronic infections, experimental and human, by Trypanosoma cruzi].

Other authors have demonstrated that itraconazole has antiparasitic activity against Trypanosoma cruzi both in vitro and in animal acute infection. Because of these observations, we decided to evaluate the chronic phase of this protozoal disease, since it is the most important form under a clinical and assistential point of view. We studied an infected mouse model as well as human cases of Chagas' disease. One hundred mg/kg/day by gastric tube, and 100 or 200 mg/day orally were given, respectively, during three months, without showing any beneficial effect, at least with the adopted methods.

Adult↗
PubMedDate not supplied

[Evaluation of the therapeutic activity of fluconazole in acute experimental infection caused by Trypanosoma cruzi].

On hand of information that fluconazole can inhibit Trypanosoma cruzi, infection, an experimental investigation in acutely infected mice treated with 200 mg/kg daily of this drug during one month was carried out. Parasitemia patency, blood culture, sub-inoculation and histologic examination were the parameters used to evaluate the potential therapeutic activity of the drug. The results did not confirm the hypothesis, but it would be desirable to conduct new trials with this and other imidazole compounds.

Acute Disease↗
PubMedDate not supplied

[Treatment of ascaridiasis with garlic (Allium sativum)].

In Brazil, there has been growing interest on alternative therapeutic approaches, as shown by asi increase of homeopathic prescriptions, and use of acupuncture and of the so called natural products. This study evaluated the usefulness of garlic (Allium sativum) for the treatment of ascaridiasis, trying to confirm the popular belief on this matter. Eight grams daily, as an infusion were used during five days, in children known to be infected with Ascaris lumbricoides. Little efficacy was observed, and this fact enhances the importance of not accepting propositions not based on adequately conducted studies.

Adolescent↗
PubMedDate not supplied

[Effect of cyclosporin and prednisone on the acute phase of experimental infection of mice by Trypanosoma cruzi].

The relations between immunosuppression and human or experimental infection by Trypanosoma cruzi have recently been the subject of great interest, specially because of the wider use of drugs acting on immunity and of organ transplantation programs, now in frank expansion. The use of cyclosporin turned necessary to know adequately its interactions with T. cruzi parasitosis, and this has been the objective of the present study, regarding the acute phase in mice, in comparison to the use of prednisone. It was verified that cyclosporin, alone or associated to the corticosteroids, promotes and enhancement of the parasitosis, as shown by the assessment of parasitemia, the amount of amastigote forms in the heart and the severity of cardiac inflammation. Such observations may be useful in clinical practice, calling the attention for necessity of a strict control of such cases an eventually the use of an antiparasitic agent.

Acute Disease↗
PubMedDate not supplied

[Evaluation of the therapeutic effect of albendazole on experimental and human infections by Hymenolepis nana].

With the objective of knowing adequately the spectrum of activity of albendazole against intestinal helminthiases, we made observations regarding hymenolepiasis caused by Hymenolepis nana. Two series of investigations were carried out: a) treatment of mice with single doses of either 25 or 50 mg/kg, repeated after ten days, using as controls animals treated with 25 mg/kg of praziquantel or not treated with any antiparasitic drugs; b) treatment of adults and children with 400 mg daily for three consecutive days, repeated after ten days.

Adolescent↗
PubMedDate not supplied

[Treatment of Schistosomiasis mansoni with a combination oxamniquine and praziquantel. II. Experimental observations during the patent phase].

The efficacy of an association of oxamniquine and praziquantel in the patent phase of experimental schistosomiasis was studied. The mice were infected and divided in four groups in accordance to the following schedules with the use of single oral doses: I--Oxaminiquine (50 mg/kg); II--praziquantel (75 mg/kg); III--association of oxamniquine (50 mg/kg) and praziquantel (75 mg/kg); and IV--no drug. Efficacy was assessed by the oogram technique, studying and classifying the evolution of the output of eggs in fragments of the small intestine, and also by recovery of the worms by portal vein perfusion. In the animals of groups I and II, the drugs had a partial effect while in the group III sinergism was evident.

Administration, Oral↗
PubMedDate not supplied

[Evaluation of the usefulness of the Coprotest for parasitologic examination of feces].

"Coprotest" is a device used for parasitological examination of the stools that has been marketed in Brazil with no previous literature support. Therefore, we decided to evaluate the usefulness of the procedure using "Coprotest", comparing it with the routine methods by Hoffman et al., Faust et al., and Rugai et al. Taking into consideration only positive samples, we observed the following figures, according to each technique: Hofmann et al.--98 (47.34%); Faust et al.--119 (57.48%); Rugai et al., only for larva detection--21 (10.14%); "Coprotest"--115 (55.55%). We concluded that "Coprotest" in addition to its operational qualities, has the merits that allow its use together with other techniques for parasitosis diagnosis. Nevertheless it has not modified the previous situation, since more than one technique must still be used, as we have noted for detection of Strongyloides stercoralis larvae in this instance.

Evaluation Studies as Topic↗