Therapeutic responses to different anti-Trypanosoma cruzi drugs in experimental infection by benznidazole-resistant parasite stock

This study describes the role of parasite clearance time induced by benznidazole, fexinidazole and posaconazole treatments upon mice infection with a benznidazole-resistant Trypanosoma cruzi strain in the pathological outcomes. Trypanosoma cruzi-infected mice were treated with different drugs and parasite clearance time was detected by blood and tissue qPCR, to determine the dynamic relationship between the efficacy of the treatments and the intensity of heart lesion/serum inflammatory mediators. Our results indicate that anti-T. cruzi treatments were able to reduce parasite replication and consequently induce immunomodulatory effects, where the degree of the immunopathology prevention was related to the time of parasite clearance induced by different treatments. Nevertheless, in benznidazole and posaconazole treatments, parasite rebounding was detected with parasitism reaching levels similar to infected and non-treated mice; the time for parasitic rebound being earlier among benznidazole-treated mice. In parallel, an increase of cardiac lesions and plasma chemokine levels was also detected and was more accentuated in benznidazole-treated animals. Interestingly, in the presence of parasitological cure (fexinidazole treatment), basal levels of these inflammatory mediators were evidenced as well as an absence of cardiac inflammation or fibrosis. Overall, our data indicate that all treatments have positive effects on the clinical evolution of T. cruzi infection, with success in preventing cardiac alterations being drug-dependen

Manejo e complicações relacionadas a corpos estranhos em otorrinolaringologia

This article seeks to present the management and complications related to foreign bodies in otorhinolaryngology. The study is an integrative literature review. It was thus possible to structure the following guiding question: “What are the complications and management related to patients with foreign bodies in otorhinolaryngology?”. A survey was carried out through the electronic library, the Virtual Health Library (BVS), and the following databases were selected: Latin American and Caribbean Literature in Health Sciences (LILACS) and Medical Literatures Analysis and Retrieval System Online (MEDLINE ). With this, the descriptors consulted in the Descriptors in Science and Health (DeCS), in the month of August 2023, were used: “Foreign bodies”, “Otorhinolaryngology” and “Hospital Medicine”, using the Boolean operator AND between the descriptors when combined. After applying the eligibility criteria, a total of 7 selected articles were used. Serious complications were defined as having a deep neck infection, esophageal perforation, and mediastinitis requiring hospitalization. Around 80 to 90% of ingested FBs pass spontaneously and the complication rate involves perforation, mucosal laceration and infection, although some are uncommon, the associated morbidity can cause hospital stays of up to six times longer than that of patients hassle free. Most situations that lead to EC accidents are preventable, and it is necessary to have improvements in the issue of training of otorhinolaryngologists in order to avoid serious complications.Este artículo busca presentar el manejo y las complicaciones relacionadas con los cuerpos extraños en otorrinolaringología. El estudio es una revisión integradora de la literatura. Fue así posible estructurar la siguiente pregunta orientadora: “¿Cuáles son las complicaciones y el manejo relacionado con los pacientes con cuerpos extraños en otorrinolaringología?”. Se realizó una encuesta a través de la biblioteca electrónica, la Biblioteca Virtual en Salud (BVS), y se seleccionaron las siguientes bases de datos: Literatura Latinoamericana y del Caribe en Ciencias de la Salud (LILACS) y Medical Literatures Analysis and Retrieval System Online (MEDLINE). Con esto, se utilizaron los descriptores consultados en los Descriptores en Ciencia y Salud (DeCS), en el mes de agosto de 2023: “Cuerpos extraños”, “Otorrinolaringología” y “Medicina Hospitalaria”, utilizando el operador booleano Y entre los descriptores cuando conjunto. Luego de aplicar los criterios de elegibilidad, se utilizaron un total de 7 artículos seleccionados. Las complicaciones graves se definieron como infección profunda del cuello, perforación esofágica y mediastinitis que requirieron hospitalización. Alrededor del 80 al 90% de los CE ingeridos pasan espontáneamente y la tasa de complicaciones involucra perforación, laceración mucosa e infección, aunque algunas son poco comunes, la morbilidad asociada puede provocar estancias hospitalarias hasta seis veces más largas que la de los pacientes sin complicaciones. La mayoría de situaciones que conducen a accidentes de CE son prevenibles, y es necesario mejorar en materia de formación de los otorrinolaringólogos para evitar complicaciones graves.Este artigo busca apresentar o manejo e complicações relacionadas a corpos estranhos em otorrinolaringologia. O estudo trata-se de uma revisão integrativa da literatura. Foi possível assim estruturar a seguinte pergunta norteadora: “Quais as complicações e manejo relacionado a pacientes com corpos estranhos em otorrinolaringologia?”. Foi feito um levantamento através da biblioteca eletrônica sendo a Biblioteca Virtual em Saúde (BVS), sendo selecionada as seguintes bases de dados: Literatura Latino-Americana e do Caribe em Ciências da Saúde (LILACS) e Medical Literatures Analysis and Retrieval System Online (MEDLINE). Com isso, foi utilizado os descritores consultados nos Descritores em Ciência e Saúde (DeCS), no mês de agosto de 2023, sendo: “Corpos estranhos”, “Otorrinolaringologia” e “Medicina Hospitalar”, utilizando o operador booleando AND entre os descritores quando combinados. Após a aplicação dos critérios de elegibilidade foram utilizados 7 artigos selecionados ao total. As complicações graves foram definidas como as que possuíam uma infecção profunda do pescoço, perfuração esofágica e mediastinite que necessitavam de hospitalização. Em torno de 80 a 90% dos CE ingeridos passam de forma espontânea e a taxa de complicações envolvem perfuração, laceração da mucosa e infecção, embora algumas sejam incomuns a morbidade associada pode causa internação hospitalar de até seis vezes mais longa do que a de pacientes sem complicações. A maioria das situações que levam a acidentes a CE são evitáveis, sendo necessário que se tenha melhorias na questão da formação dos otorrinolaringologistas a fim de evitar sérias complicações

Patologias atuais: a compulsão e a sociedade dos excessos: Current pathologies: compulsion and the society of excesses

O artigo em tela tem por objetivo analisar os aspectos biopsicossociais da conduta compulsiva de consumo. Propõe-se a apresentar os elementos psicológicos contidos nesse comportamento, além de verificar quais são os resultados decorrentes dessa compulsão. O consumo compulsivo, também chamado de oniomania, é um transtorno causado pela ansiedade despertada pela necessidade de comprar e saciada, somente, quando é materializada a aquisição daquilo que se deseja comprar. O estudo em questão pode ser classificado como sendo de cunho bibliográfico, a partir da análise de documentos publicados em forma de artigos científicos e livros em formato digital

Avaliação do efeito do tratamento com benznidazol em combinação com derivados azólicos na infecção experimental por Trypanosoma cruzi.

Programa de Pós-Graduação em Ciências Biológicas. Núcleo de Pesquisas em Ciências Biológicas, Pró-Reitoria de Pesquisa e Pós Graduação, Universidade Federal de Ouro Preto.A doença de Chagas, causada pelo protozoário Trypanosoma cruzi, é um importante problema de saúde pública e o tratamento dessa parasitose apresenta limitações relacionadas à eficácia e toxicidade dos fármacos disponíveis. Nesse sentido, a terapia de combinação de fármacos parece ser uma abordagem ideal na busca de novos tratamentos, pois pode possibilitar aumento da eficácia, redução da toxicidade e da probabilidade de desenvolvimento de resistência. O objetivo deste estudo foi avaliar o efeito do tratamento com benznidazol (Bz) quando combinado com os inibidores da enzima esterol C14α-demetilase (CYP51), os derivados azólicos posaconazol (Ps) e ravuconazol (Rv) (ou a pró- droga do Rv, o E1224), na infecção por T. cruzi in vitro e in vivo. Inicialmente foi avaliada a eficácia do Ps em combinação com Bz durante a infecção aguda de camundongos pela cepa Y de T. cruzi. O tratamento combinado, utilizando doses subótimas, foi mais eficaz em induzir cura parasitológica quando comparado com a utilização de cada fármaco isoladamente, indicando uma interação positiva entre Bz e Ps. Quando avaliada a eficácia do tratamento sequencial com Bz ou Ps administrados em doses ótimas durante um curto intervalo de tempo (10 dias cada), verificou-se que a ordem de administração dos fármacos interfere no resultado do tratamento, sendo a sequência Bz seguido de Ps mais eficaz. Além disso, a terapia combinada induziu uma redução significativa da carga parasitária em camundongos infectados pela cepa VL-10 de T. cruzi, altamente resistente ao Bz, quando comparada às drogas administradas em monoterapia. Considerando esses resultados promissores, foi a seguir investigada a atividade da combinação do Bz com o Rv. Inicialmente foram realizados experimentos in vitro para definir a natureza da interação entre esses fármacos. A princípio, foram determinados os valores de IC-50 do Bz e do Rv sobre formas epimastigotas e amastigotas das cepas Y e Colombiana de T. cruzi. A seguir, o efeito de combinações de Rv e Bz, preparadas de acordo com o método de proporções fixas, foi avaliado nesses modelos. A análise dos resultados foi feita por meio do cálculo das concentrações inibitórias fracionárias (FICs) e do somatório das FICs (ΣFICs) para cada combinação. A natureza da interação foi classificada em função do ΣFICs: sinergismo se ΣFIC≤0,5; indiferença (aditividade) se 0,5<ΣFIC<4 e antagonismo se ΣFIC>4. As combinações de Rv e Bz mostraram-se aditivas, com valores de ΣFIC próximo a 1 para ambas as cepas e diferentes formas evolutivas do parasito estudadas. Dessa forma, o próximo passo foi avaliar o efeito do Rv (em forma de pró-fármaco, o E1224) em combinação com o Bz na infecção por T. cruzi in vivo. Inicialmente foi realizado um experimento para definição das doses de E1224 a serem utilizadas em monoterapia. O pró-fármaco foi efetivo em curar camundongos infectados pela cepa Y de T. cruzi de forma mais eficiente do que o composto precursor, o ravuconazol. Não foi observado efeito dose-dependente; os tratamentos com doses de 10 a 50mg/kg de peso induziram 71 % a 100 % de cura. De forma diferente, o tratamento dos animais infectados pelas cepas Colombiana e VL -10 foi eficaz em induzir uma intensa redução da carga parasitária, mas não em induzir cura. Finalmente, o tratamento com combinações de Bz e E1224 administrado a camundongos infectados pela cepa Colombiana resultou em maior taxa de cura, em relação às monoterapias, quando a terapêutica foi iniciada aos 4 dias após a infecção. Entretanto, quando usado um protocolo mais estringente, no qual o tratamento foi iniciado aos 10 dias após a infecção, houve redução significativa da carga parasitária, mas ausência de cura parasitológica. Os resultados obtidos nesse estudo demonstram o benefício da terapia da combinação usando derivados azólicos e benznidazol no tratamento da infecção experimental por T. cruzi e ampliam os dados pré-clínicos relacionados ao uso de combinações de fármacos no tratamento de protozooses.Chagas disease, caused by the protozoan pathogen Trypanosoma cruzi, remains a challenging infection due to the unavailability of safe and efficacious drugs. Combined therapy is envisioned as an ideal approach since it may improve treatment efficacy whilst decreasing toxicity and the likelihood of resistance development. The objective of this study was to evaluate the effect of treatment with Bz when combined with sterol 14α-Demethylase (CYP51) inhibitors posaconazole (Ps) and E1224 (pro-drug of ravuconazole - Rv) in experimental infection with T. cruzi. Initially, we evaluated the efficacy of Ps in combination with Bz during acute infection of mice with T. cruzi Y strain. The drugs were administered individually or in combination for 20 consecutive days. Bz/Ps combined treatments were found to be significantly more efficacious in inducing higher parasitological cure rates than those observed when the drugs were used alone, indicating a positive interaction between Bz and Ps. In addition, the combined therapy induced a significant reduction of parasite load in mice infected with VL-10, a benznidazole-resistant T. cruzi strain, compared to single administration of drugs. Subsequently, sequential therapy experiments were carried out with Bz or Ps over a short interval (10 days), followed by the second drug administered for the same period of time. It was found that the sequence of Bz followed by Ps provided cure rates comparable with those obtained with the full treatments with either drug alone, with no cures observed for the short treatments with drugs given alone. Considering these promising results, the next step was to investigated the activity of Bz and Rv combinations. First, we performed in vitro experiments to define the nature of interaction between Bz and Rv. IC-50 values for Bz and Rv were determined upon epimastigotas and amastigotes of Y and Colombian strains of T. cruzi. The drug combinations were evaluated on the same models. Drug susceptibility was assessed with a modified fixed ratio isobologram method. Fractional inhibitory concentrations (FICs), sum FICs (ΣFICs) and an overall mean ΣFIC were calculated for each combination. The nature of interaction was classified on the basis of the mean ΣFIC as follows: synergy as mean ΣFIC<0.5, indifference as mean between 0.5 and 4.0 and antagonism as mean ΣFIC>4. The interaction between Bz and Rv was indifferent with ΣFIC near to 1 for both strains. In this way, it was evaluated the effect of Rv (pro-drug, E1224) in combination with Bz upon in vivo infection. First, an experiment to define the optimal dose of E1224 in monotherapy was performed. The pro-drug of Rv, showed activity higher than demonstrated previously for the parent compound in the model of acute murine infection by strain Y. There was no dose-dependent effect, the treatments with 10 up to 50mg/kg weight for 20 consecutive days induced 71% to 100% of cure. Differently, the treatment of animals infected with Colombian or VL-10 strains was very effective in reducing the parasitemia, but led to nil cure rates. Finally, the effect of the E1224 and Bz combination against epimastigote and amastigote of Y and Colombian strains was evaluated. Additionally, the treatment of mice with E1224 in combination with Bz induced higher cure rate in mice infected with Colombian strain when the treatment started 4 days after infection or a significant reduction of parasite load in treatments started 10 days after infection, compared to single administration of drugs. This study expands the preclinical data on drug combinations and provides the basis for further studies as anti-T. cruzi chemotherapy is moving towards multidrug treatment regimens

Avaliação da atividade anti-Trypanosoma cruzi do derivado triazólico Ravuconazol utilizando o cão como modelo experimental.

O Ravuconazol é um derivado triazólico de quarta geração que possui potente atividade antifúngica e intensa atividade anti- Trypanosoma cruzi in vitro. Neste estudo foi avaliada a atividade do Ravuconazol in vivo contra as cepas Y e Berenice-78 do T. cruzi, utilizando cães na fase aguda da doença como modelo experimental. A droga foi bem tolerada e não foram observadas reações adversas durante o tratamento utilizando 12,0 mg de Ravuconazol por quilograma de peso corporal durante 90 dias. Em todos os animais a parasitemia foi permanentemente suprimida a partir do primeiro dia de tratamento, independentemente da cepa do parasito. A hemocultura realizada trinta dias após o término do tratamento foi negativa em todos os animais, confirmando a acentuada redução da carga parasitária induzida pela droga. Em acordo com esses resultados, a técnica de PCR realizada um mês após o tratamento revelou resultados negativos em 3/5 e 2/5 dos animais infectados com as cepas Y e Be-78, respectivamente. O tratamento levou à redução significativa nos níveis de anticorpos anti-T.cruzi no sangue dos cães, sendo não detectáveis em alguns períodos enquanto a pressão da droga foi mantida; porém, após o término do tratamento, os níveis de IgG total e IgG2 elevaram-se novamente; indicando que a cura parasitológica não foi alcançada. Entretanto, mesmo não sendo capaz de induzir a cura parasitológica, o tratamento com Ravuconazol levou à redução significativa das lesões cardíacas e da expressão de mRNA para IFN- no tecido cardíaco nos animais infectados com a cepa Y, enquanto a expressão de IL-10 foi aumentada. Deste modo, conclui-se que o Ravuconazol possui potente atividade supressiva, mas não curativa no modelo agudo da doença de Chagas canina, provavelmente devido às propriedades farmacocinéticas desfavoráveis nesse modelo (tempo de meia-vida de 8,8 horas). Em humanos, o perfil farmacocinético da droga é mais favorável (tempo de meia-vida de 120 horas), fazendo desse composto um forte candidato à quimioterapia da doença de Chagas humana.Ravuconazole is an experimental triazole derivative with potent and broad-spectrum antifungal activity and also very potent in vitro anti-Trypanosoma cruzi activity. In this work, we investigated the in vivo activity of ravuconazole against Y and Berenice-78 T. cruzi strains using acutely infected dogs as hosts. Ravuconazole was well tolerated as no significant side effects were observed during the treatment using 6.0 mg/kg b.i.d (12mg/kg.d.) for up to 90 days. In all treated animals parasitemia was permanently suppressed by the first day of treatment, independently of the parasite strain. Blood culture performed post-treatment was negative in all animals, confirming a marked reduction of the parasite load induced by drug. Consistently, T.cruzi blood PCR tests performed one month post-treatment was negative in 3/5 and 2/5 of animals infected with Y strain and Berenice-78 strain, respectively. Treatment led to significant reduction on levels of anti-T. cruzi antibodies while the drug pressure was maintained, but after the end of this treatment antibodies levels (IgG and IgG2), though not those of the IgG1 subclass, raising slowly but without reaching the same level of untreated controls, indicating that parasite clearance was not achieved. However, despite being unable to induce parasitological cure, ravuconazole treatment led to a significant reduction of the cardiac lesions and IFN-gamma m-RNA expression in cardiac tissues in animals infected with the Y strain, while IL-10 mRNA expression increased. We conclude that ravuconazole has potent suppressive but not curative activity in canine model of acute Chagas disease, probably due to unfavorable pharmacokinetic properties (half-life 8.8 hours). In man, where the pharmacokinetic profile of the drug is more favorable (half-life 120 hours), it is to be expected that the anti-T. cruzi efficacy of ravuconazole should be higher, making it a promising candidate for specific Chagas disease chemotherapy

Outcome of E1224-Benznidazole combination treatment for infection with a multidrug-resistant Trypanosoma cruzi strain in mice.

Combination therapy has been proposed as an alternative therapeutic approach for the treatment of Chagas disease. In this study, we evaluated the effect of treatment with benznidazole combined with E1224 (ravuconazole prodrug) in an experimental murine model of acute infection. The first set of experiments assessed the range of E1224 doses required to induce parasitological cure using Trypanosoma cruzi strains with different susceptibilities to benznidazole (Y and Colombian). All E1224 doses were effective in suppressing the parasitemia and preventing death; however, parasitological cure was observed only in mice infected with Y strain. Considering these results, we evaluated the effect of combined treatment against Colombian, a multidrug-resistant T. cruzi strain. After exclusion of antagonistic effects using in vitro assays, infected mice were treated with E1224 and benznidazole in monotherapy or in combination at day 4 or 10 postinoculation. All treatments were well tolerated and effective in suppressing parasitemia; however, parasitological and PCR assays indicated no cure among mice treated with monotherapies. Intriguingly, the outcome of combination therapy was dependent on treatment onset. Early treatment using optimal doses of E1224-benznidazole induced a 100% cure rate, but this association could not eliminate a well-established infection. The beneficial effect of combination therapy was evidenced by further reductions of the patent parasitemia period in the group receiving combined therapy compared with monotherapies. Our results demonstrated a positive interaction between E1224 and benznidazole against murine T. cruzi infection using a multidrug-resistant strain and highlighted the importance of a stringent experimental model in the evaluation of new therapies

Trypanosoma cruzi : acute and long-term infection in the vertebrate host can modify the response to benznidazole.

We analyzed the influence of Trypanosoma cruzi maintenance in different hosts (dog and mouse) on its susceptibility to benznidazole treatment. Five T. cruzi stocks were isolated from dogs inoculated with Be-62 or Be-78 strain (both sensitive to benznidazole) 2–10 years ago, and the benznidazole sensitivity was then determined using the mouse as experimental model. The different T. cruzi stocks obtained from long-term infected dogs showed 50–90% drug resistance right after isolation. However, maintenance of these T. cruzi stocks in mice, by successive blood passages (2.5 years), led to either a decrease or stability of the drug resistance pattern and an increase in parasite virulence. We also demonstrated the effectiveness of the induction of parasitemia reactivation by cyclophosphamide immunosuppression in the evaluation of the response to the specific drug treatment

Effects of Ravuconazole Treatment on Parasite Load and Immune Response in Dogs Experimentally Infected with Trypanosoma cruzi▿

In this work, we investigated the in vivo activity of ravuconazole against the Y and Berenice-78 Trypanosoma cruzi strains using acutely infected dogs as hosts. Ravuconazole was well tolerated, as no significant side effects were observed during the treatment using 6.0 mg/kg twice a day (12 mg/kg/day) for up to 90 days. In all treated animals, parasitemia was permanently suppressed by the first day of treatment, independently of the parasite strain. Cultures of blood obtained posttreatment were negative for 90% of the animals, confirming that the drug induced a marked reduction in the parasite load. The results of PCR tests for T. cruzi in blood performed 1 month posttreatment were consistently negative for three of five and two of five animals infected with the Y and Berenice-78 strains, respectively. All ravuconazole-treated dogs consistently had negative serological test results during and until 30 days after treatment, regardless of the therapeutic scheme used. However, after the end of treatment, an increase in specific antibody levels was observed in all treated animals, although the antibody levels were always significantly lower than those of the nontreated control dogs. Despite being unable to induce a parasitological cure, ravuconazole treatment led to significant reductions in the levels of gamma interferon expression and lesions in cardiac tissues in animals infected with the Y strain, while the level of interleukin-10 mRNA expression increased. We conclude that ravuconazole has potent suppressive but not curative activity in the canine model of acute Chagas' disease, probably due to its unfavorable pharmacokinetic properties (half-life, 8.8 h). The longer half-life of ravuconazole in humans (4 to 8 days) makes it a promising drug for assessment for use as chemotherapy in human Chagas' disease