Mastocytosis: a rare case of anaphylaxis in paediatric age and literature review

The term "mastocytosis" denotes a heterogeneous group of disorders characterised by abnormal growth and accumulation of mast cells (MC) in one or more organ systems. Symptoms result from MC chemical mediator's release, pathologic infiltration of neoplastic MC in tissues or both. Multiple molecular, genetic and chromosomal defects seem to contribute to an autonomous growth, but somatic c-kit D816V mutation is more frequently encountered, especially in systemic disease. We present a literature review of mastocytosis and a rare case report of an 18 month-old-girl with a bullous dermatosis, respiratory distress and anaphylaxis, as clinical manifestations of mastocytosis. The developments of accepted classification systems and novel useful markers allowed a re-evaluation and updating of the classification of mastocytosis. In paediatric age cutaneous forms of disease prevail and may regress spontaneously. SM is more frequently diagnosed in adults and is a persistent (clonal) disease of bone marrow. The clinical course in these patients is variable. Today diagnostic criteria for each disease variant are reasonably well defined. There are, however, peculiarities, namely in paediatric age, that makes the diagnostic approach difficult. Systemic disease may pose differential diagnostic problems resulting from multiple organ systems involvement. Conversely, the "unexplained" appearance of those symptoms with no skin lesions should raise the suspicion of MC disease. This case is reported in order to stress the clinical severity and difficult diagnostic approach that paediatric mastocytosis may assume.

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.

[Aedes albopictus in rural zone of Brazil and its implication in the wild yellow fever transmission]

Larvae and adult forms of Aedes albopictus were found during ecological study of anopheline mosquitos in the rural zone of the state of Mato Grosso do Sul in Brazil. This occurrence was registered, for the first time in Brazil, in an enzoootic area if sylvatic yellow fever virus. This implies a potential risk of the transfer of this virus to an urban area infested with Aedes aegypti.

Santo Inácio revisited: protozoan diseases in an isolated village in northeastern Brazil after twenty years

The northeastern highlands of Brazil are endemic for several tropical diseases, especially American trypanosomiasis (Chagas' disease) and schistosomiasis. Twenty years ago, we measured the seroprevalence of protozoan diseases in Santo Inácio, a village of approximately 1,000 inhabitants located 1,000 m above sea level. We detected small numbers of sera with antibodies against Trypanosoma cruzi and Toxoplasma gondii, and the area had a low prevalence both of American trypanosomiasis (3.54%) and toxoplasmosis (27.43%) compared with nearby Brazilian areas. This was attributed to a specific triatomine vector and local housing conditions. Twenty years later, we again determined the prevalences of both diseases and compared these results with those from Iraquara, a larger town with the same ethnic and social background but with a higher prevalence of rural activities. The incidence of Chagas' disease in San Inácio showed the same low level, i.e., 3.78% (5 of 132) with only adult males affected in contrast with Iraquara, which had an incidence of 34.5%, but a low prevalence of only one of 22 among children up to 14 years of age. Santo Inácio maintained a low (25.8%) seroprevalence for toxoplasmosis. Housewives presented a higher incidence of toxoplasmosis during both periods, probably due to related risk factors. Cats were found less frequently in Santo Inácio than in Iraquara, which showed an incidence of 65.5% seropositivity for Toxoplasma gondii. These results suggest that the environmental conditions of Santo Inácio were preserved after 20 years, with a low incidence of these selected protozoan diseases.

Atopy and enteroparasites

There are not many studies about the intestinal parasitosis (IP) and atopic asthma (AA) relationship, and these show discordant results, possibly due to different studies design and differences in population selection. On the basis of personal results obtained by an epidemiological inquiry designed to estimate the prevalence of enteroparasitoses in asthmatic children and vice vesa, the aim of this study was to compare the prevalence of IP in AA and in a control group (CG) by a cross sectional study using clinical and laboratorial parameters, applied to 63 children (47 with AA and 16 in CG) aged 6 to 11 years, 37 males and 26 females, Caucasians, with the same socioeconomical conditions, consecutively selected in our Hospital. The results showed: The IP in AA children was 21.3%; the IP in CG was 25%; in the group with AA and IP, 40% of them had symptomology of IP; in the CG with IP, 100% had symptoms.

CONCLUSIONS

The IP prevalence in AA was not statistically different from the IP in CG (p > 0.05) More data are needed to clarify the significant differences between the symptomatology rates of IP in asthmatic and non asthmatics; the reduced number of patients with symptoms in AA may reflect modulation of IP in AA and/or different parasite load.

Soluble CD30, dehydroepiandrosterone sulfate and dehydroepiandrosterone in atopic and non atopic children

Elevated levels of soluble CD30-sCD30 (possibly related to Th2) are seen in atopy and other diseases. Dehydroepiandrosterone (DHEA) may regulate Th1/Th2 balance. The aim was to study the relationship between the levels of sCD30, DHEAS and DHEA in atopic (A) and non atopic (B) children, to assess immune-endocrine interactions. We studied 36 children (8-15 years), 18 (A) monosensitised to Dermatophagoides Pteronyssinus (Dpt.), and 18 (B) with isolate rhinitis (R) or asthma (BA) and R (33.3%) without differences in age and sex. They were all HIV negative and free from any medication. It was determined sCD30, DHEAS and DHEA. There was no statistically significant differences between A and B for the levels of DHEAS, DHEA suggesting that the role of this regulation in Th2 type is not important in patients with allergic disease in this age group. sCD30: A-mean 121.1U/ml; B-mean 53.9U/ml. This difference is statistically significant-p = 0.02. sCD30 in patients only with R showed also significant differences-p = 0.01. These results could reflect the Th2 profile. There is an overlap of the values (for R < 80 U/ml; for BA + R < 140 U/ml). Due to this only values > 80 U/ml for R and > 140 U/ml for BA + R could be considered discriminating for atopy.

ALATOP-RIA in the screening of atopy in a non Caucasian population

ALATOP is an "in vitro" radioimmunoassay screening test for atopy, previously validated in a caucasian population. The aim of the study was to assess the usefulness of a screening test of atopy in a non caucasian population. We select a non caucasian population (n = 208), from hospital immunoallergy consultations, Cape Verde Republic (Africa). It was determined the sensitivity, specificity and predictive values comparing with skin prick tests (SPT) results for the 208 patients, and with clinical data (Clin) in 115 patients. It was also determined the levels of total IgE, done by IRMA.

RESULTS

Using different corrections factors, 0.85 gives the best results: ALATOP/SPT-Sensitivity-88.5% +/- 4.34; Specificity-73.8% +/- 8.41; Positive predictive value-66.9%; Negative predictive value-91.4%; Efficiency of the test-79.3%. ALATOP/CLIN-Sensitivity-95.2% +/- 3.89; Specificity-71.2% +/- 12.07; Positive predictive value-65.6%; Negative predictive value-96.2%; Efficiency of the test-80.0%. The mean values of total IgE were-406 IU/ml.

CONCLUSIONS

The mean value of total IgE was significantly increased even in the ALATOP-/SPT-not saw in caucasian populations. The use of a different correction factor (0.85) for ALATOP, optimize the test, showing a good negative predictive value, but raises the question of adapted compositions of screening tests for different populations.

Simultaneous occurrence of acute myocarditis and reactivated Chagas' disease in a patient with AIDS

Myocarditis is not an uncommon finding in autopsy series of patients with AIDS, although clinically important myocarditis is rarely noted. We describe a 50-year-old woman with AIDS and chronic chagasic megaesophagus, without previous cardiac abnormalities, who experienced reactivation of Chagas' disease, characterized by the finding of Trypanosoma cruzi via direct microscopic examination of the buffy coat, xenodiagnosis, and blood culture; she developed fatal acute myocarditis. Reactivation of Chagas' disease in patients with AIDS has been reported, but in the great majority of cases it has been associated with central nervous system involvement. In areas where Chagas' disease is endemic, reactivation may occur in patients with AIDS.

Dot-ELISA for the detection of IgM and IgG antibodies to Schistosoma mansoni worm and egg antigens, associated with egg excretion by patients

Human schistosomiasis, caused by Schistosoma mansoni, is highly prevalent in Brazil and usually diagnosed by time consuming stool analysis. Serological tests are of limited use in this disease, mainly for epidemiological studies, showing no discrimination between previous contact with the parasite and active infections. In the present study, we standardized and compared a Dot-ELISA for IgM and IgG antibodies against S. mansoni antigens from eggs and worms with a routine IgG and IgM immunofluorescence assay using similar antigens, in the study of sera from 27 patients who had quantified egg stool excretion. The positivity obtained for IgG Dot-ELISA was 96.3% and 88.9% for IgM Dot-ELISA with worm antigen and 92.6% and 90.9% with egg antigen. The IFI presented similar positivities using worm antigen, 92.6% (IgG) and 96.3% (IgM), and lower results with egg antigen, 77.8%(IgG and IgM). The patients studied were divided into two groups according to their egg excretion, with greater positivity of serological tests in higher egg excreters. When comparing the quantitative egg excretion and the serological titers of the patients, we detected a correlation only with IgM Dot-ELISA, with r = 0.552 (p = 0.0127). These data show that Dot-ELISA can be used for the detection of specific antibodies against S. mansoni in sera from suspected patients or in epidemiological studies and, with further purification of egg antigen and larger samples, IgM Dot-ELISA could be a possible tool for rough estimates of parasite burden in epidemiological studies.

Quantitative skin prick tests and specific IgE (CAP System) for D. pteronissynus--correlation of results in a paediatric population

The CAP System compared with RAST has a greater sensitivity, with the same specificity, as well as an excellent correlation with skin prick tests (SPT), as documented by others. Standardization of SPT is essential for routine and investigational purposes. We used a standardized lancet (DHS), and the methodology of reading the SPT was a computerized digitalized graphics tablet coupled to an IBM-PC AT using CAD software, expressing the result as wheal areas with cut off +/- at 7 mm2. The method is precise and reproducible with a mean coefficient of variation (cv) intratester--T1: 3.1%, T2: 3.5% and a cv intertester: 2.93%. We compare the results of SPT of two different allergen extracts for Dermatophagoides Pteronissynus (DPt) (Bencard; Merck/Allergo-Pharma, standardized in SBU) and correlate them with specific IgE, in 122 patients, 72 males and 50 females, aged 3 to 19 years. The results between the extracts and the results of specific IgE obtained by CAP System with each of the extracts, were correlated. 34 patients were considered to be non atopic. 88 patients showed at least one positive result with one test, being those used to correlate the positive results.... The results showed good correlations for quantitative SPT between Bencard and Merck/Allergo-Pharma, as well as for the capacity of eliciting positive results. When SPT were compared to specific IgE as +/- and as quantitative results, there were good correlation for Bencard/CAP and Merck/CAP. The results obtained suggest that CAP can be used to validate allergen extracts of DPt and that studies with other extract are advisable.

ALATOP:sensitivity, specificity and predictive value of a new "in vitro" screening test of atopy

The limitations of total IgE for the screening of atopy, gave rise to in vitro multispecific IgE tests to common allergens. These should have an increased sensitivity and specificity when compared to total IgE. Previous data showed the interest of such tests in screening procedures. ALATOP is a new in vitro multispecific IgE test including common aero and food allergens, in liquid phase, for paediatric and adult population. The result is expressed only in positive/negative. The aim of the study was to determine the sensitivity, specificity, positive and negative predictive value and test efficiency, by comparing the results obtained in 266 paediatric patients (selected in our Unit based on a good correlation between clinical history and skin prick tests--SPT), between ALATOP and SPT.

RESULTS

1) Sensitivity: 89.57%; 2) Specificity: 98.06%; 3) Positive predictive value: 98.65%; 4) Negative predictive value: 85.59%; 5) Efficiency of the test: 92.86%; 6) Reproducibility of the test--average: 5.63%. Based on this results and when they are compared to single specific IgE determinations, that are assumed to be about 80% of the sensitivity of SPT, ALATOP showed excellent results, allowing its use in the screening of atopic disease.

[Effect of quinolones on mice experimental infection by Plasmodium berghei and their possible therapeutic usefulness]

The search for new antimalarial drugs is important for many reasons, specially because of the resistance of plasmodia. Some clinical and laboratory studies have recently indicated that quinolones, currently in use for treatment of bacterial infections, have antimalarial activity. So, we evaluated the possible action of ciprofloxacin, norfloxacin, ofloxacin and pefloxacin in mice experimentally infected by Plasmodium berghei, by the oral route. Taking into account parasitemia and mortality, we came to conclusion that these drugs are not effective, as judged by the methods used.

[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.

[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.

[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.

[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.

[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.

[Viability of Trypanosoma cruzi in sugar cane juice]

In Catolé do Rocha, State of Paraíba, Brasil several people were concomitantly contaminated by Chagas' disease and had the acute form of the infection. Because of this event, the hypothesis that Trypanosoma cruzi might have been transmitted by the digestive route, through the ingestion of accidentally contaminated sugar cane juice, was made. In the present study, we verified that the parasite has remained viable for four hours in the liquid, at room temperature. We have also demonstrated that, after one hour, it was capable of promoting infection in one mouse, by gastric tube administration. These observations enhance the interest on this alternative mechanism of disease transmission.

[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.

[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.

[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.

[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.

[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.

[Treatment of experimental infection by Strongyloides venezuelensis in rats, with the use of injectable ivermectin and levamisole]

For the therapy of human strongyloidiasis, are necessary effective drugs to eliminate both larvae and adult worm parasitism, which may also be used by parenteral route, to obviate the particular conditions presented by many patients. A study based on the experimental infection by Strongyloides venezuelensis in rats was done, administering injectable ivermectin or levamisole. Both drugs were shown to be active, when used in single doses of 0.2 to 0.5 mg/kg of ivermectin, or 26 mg/kg for levamisole. Ivermectin was slightly more effective as far as larval stage of the infection is concerned, and the same happened for levamisole for the adult worm stage. Promising perspectives are visualized to improve the therapy of patients with serious disseminated infection by Strongyloides stercoralis.

[In vitro activity of gentian violet on evolutive forms of Plasmodium falciparum]

In order to investigate whether gentian violet exhibited "in vitro" inhibitory activity against Plasmodium falciparum, the Authors have carried out 20 sensitivity tests according to the microtechnique described by RIECK MANN et al.5. Results have shown inhibition of schizonts'maturation at the following concentration: 1/1000; 1/1500; 1/2000; 1/2500; 1/3000 and 1/4000, thus demonstrating inhibitory activity of the tested dye against asexual blood parasites. The present data suggest gentain violet may be possibly used in the prophylaxis of transfusion-acquired malaria.

[Detection of heavy helminth eggs in feces: comparative study of the spontaneous sedimentation in water and Ritchie's methods]

Com a finalidade de melhor conhecer a sensibilidade do método de Ritchie (centrífugos edimentação em formol-éter), quanto ao diagnóstico de parasitoses intestinais pelo exame das fezes, foi investigada a capacidade dele no sentido de detectar ovos “pesados" de helmintos (Schistosoma mansoni e Ascaris lumbricoides inférteis). Houve comparação com o desempenho do processo da sedimentação espontânea em água, usado com o mesmo intuito. Os resultados obtidos e a respectiva avaliação estatística demonstraram que a técnica da sedimentação espontânea em água é mais eficiente, tendo sido analisadas 300 amostras de fezes, metade das quais certamente contendo os dois tipos de ovos citados e a outra parte considerada em trabalho laboratorial rotineiro.

[Evaluation of the sensitivity of the Suzuki technic for the hatching of miracidia in comparison with other processes use in the diagnosis of schistosomiasis mansoni]

Para simplificar o diagnóstico da esquistossomose mansônica há interesse de utilizar exame das fezes executado com base na eclosão de miracidios. Foi analisada a sensibilidade do método idealizado por Suzuki, através de comparação com os processos de Kato-Katz, Hoffman, Pons e Janer (sedimentação espontânea em água) e Chieffi e cols. Ficou comprovado que a tática em apreço é útil, mas não suplanta os méritos das outras empregadas, apresentando todavia melhor resultado quando presentes nas fezes maiores quantidades de ovos.

[Research on helminth eggs and protozoan cysts on money]

Em virtude da elevada prevalência de parasitoses intestinais no Brasil e da possível participação de objetos na transmissão dessas afecções, foi desenvolvida pesquisa envolvendo dinheiro difundido na coletividade. Foram analisadas, quanto à presença de ovos de helmintos e de cistos de protozoários, 1.003 cédulas e 1.011 moedas, de valores e procedências diversos. Do estudo resultou o encontro de cistos de Entamoeba histolytica em duas eventualidades, de ovos de Ascaris lumbricoides larvado e infértil, de ovo de Taenia sp. morfologicamente íntegro e de outros elementos não patogênicos. Ficou salientada a importância do dinheiro circulante na epidemiologia das enteroparasitoses, tendo havido sugestão de novos trabalhos de natureza congênere, inclusive delineando diretrizes de ordem profilática.

[Effect of gamma rays on blood forms of Trypanosoma cruzi. Experimental study in mice]

Amostras de sangue de animais infectados com cepa Y de Trypanosoma cruzi foram submetidas, respectivamente, a 200 e 300 krad de radiação gama. Para verificar a eficácia do método na eliminação do parasita, o material foi inoculado em camundongos e os parâmetros utilizados na avaliação foram: parasitemia, cultura, xenodiagnóstico, subinoculação, reinoculação com cepa virulenta e exame anátomo-patológico das vísceras. Os sangues expostos às duas diferentes intensidades de radiação e inoculados em dois períodos após o processo, mostraram-se inócuos quanto a capacidade de produzir infecção nos animais

[Experimental study of the possible activity of gentian violet in preventing the transmission of toxoplasmosis due to blood transfusion]

Devido a evidências sugestivas da possibilidade de transmissão da toxoplasmose por transfusão de sangue, os autores se propuseram avaliar o papel preventivo da violeta de genciana, à semelhança do que já é estabelecido para a doença de Chagas. O experimento em camundongos revelou a ação profilática da violeta de genciana quando adicionado ao sangue a ser transfundido na concentração de 1/1000 e permanência por 48 horas na geladeira.