ABSTRACT
The adequate management of parasite co-infections represents a challenge that has not yet been overcome, especially considering that the pathological outcomes and responses to treatment are poorly understood. Thus, this study aimed to evaluate the impact of Schistosoma mansoni infection on the efficacy of benznidazole (BZN)-based chemotherapy in Trypanosoma cruzi co-infected mice. BALB/c mice were maintained uninfected or co-infected with S. mansoni and T. cruzi, and were untreated or treated with BZN. Body weight, mortality, parasitemia, cardiac parasitism, circulating cytokines (Th1/Th2/Th17); as well as heart, liver and intestine microstructure were analyzed. The parasitemia peak was five times higher and myocarditis was more severe in co-infected than T. cruzi-infected mice. After reaching peak, parasitemia was effectively controlled in co-infected animals. BZN successfully controlled parasitemia in both co-infected and T. cruzi-infected mice and improved body mass, cardiac parasitism, myocarditis and survival in co-infected mice. Co-infection dampened the typical cytokine response to either parasite, and BZN reduced anti-inflammatory cytokines in co-infected mice. Despite BZN normalizing splenomegaly and liver cellular infiltration, it exacerbated hepatomegaly in co-infected mice. Co-infection or BZN exerted no effect on hepatic granulomas, but increased pulmonary and intestinal granulomas. Marked granulomatous inflammation was identified in the small intestine of all schistosomiasis groups. Taken together, our findings indicate that BZN retains its therapeutic efficacy against T. cruzi infection even in the presence of S. mansoni co-infection, but with organ-specific repercussions, especially in the liver.
Subject(s)
Chagas Disease , Coinfection , Myocarditis , Nitroimidazoles , Schistosomiasis mansoni , Mice , Animals , Myocarditis/parasitology , Schistosoma mansoni , Parasitemia/drug therapy , Chagas Disease/drug therapy , Cytokines/therapeutic use , GranulomaABSTRACT
Viral inactivation for antibody induction purposes, among other applications, should ensure biosafety, completely avoiding the risk of infectivity, and preserving viral immunogenicity. ß-propiolactone (BPL) is one of the most used reagents for viral inactivation, despite its high toxicity and recent difficulties related to importation, experienced in Brazil during the SARS-CoV-2 pandemic. In this context, the main objectives of this work were to test different inactivation procedures for SARS-CoV-2 and to evaluate the induction of neutralizing antibodies in mice immunized with antigenic preparations obtained after viral treatment with formaldehyde (FDE), glutaraldehyde (GDE), peroxide hydrogen (H2O2), as well as with viral proteins extract (VPE), in parallel with BPL. Verification of viral inactivation was performed by subsequent incubations of the inactivated virus in Vero cells, followed by cytopathic effect and lysis plaques observation, as well as by quantification of RNA load using reverse transcription-quantitative real time polymerase chain reaction. Once viral inactivation was confirmed, cell culture supernatants were concentrated and purified. In addition, an aliquot inactivated by BPL was also subjected to viral protein extraction (VPE). The different antigens were prepared using a previously developed microemulsion as adjuvant, and were administered in a four-dose immunization protocol. Antibody production was comparatively evaluated by ELISA and Plaque Reduction Neutralization Tests (PRNT). All immunogens evaluated showed some level of IgG anti-SARS-CoV-2 antibodies in the ELISA assay, with the highest levels presented by the group immunized with FDE-inactivated viral antigen. In the PRNT results, except for VPE-antigen, all other immunogens evaluated induced some level of neutralizing anti-SARS-CoV-2 antibodies, and the FDE-antigen stood out again with the most expressive values. Taken together, the present work shows that FDE can be an efficient and affordable alternative to BPL for the production of inactivated SARS-CoV-2 viral antigen.
Subject(s)
COVID-19 , SARS-CoV-2 , Animals , Antibodies, Viral , Antigens, Viral , Chlorocebus aethiops , Disease Models, Animal , Hydrogen Peroxide , Mice , Vero CellsABSTRACT
In the present study, the ethanolic extract from aerial parts of Ageratum fastigiatum was evaluated in vitro against epimastigote forms of Trypanosoma cruzi (Y strain), promastigote forms of Leishmania amazonensis (PH8 strain), and L. chagasi (BH400 strain). The extract was also evaluated against Staphylococcus aureus (ATCC 25â923), Escherichia coli (ATCC 11â775), Pseudomonas aeruginosa (ATCC 10â145), and Candida albicans (ATCC 36â802). The phytochemical screening was performed by thin-layer chromatography and high-performance liquid chromatography. The extract was fractionated using flash preparative chromatography. The ethanolic extract showed activity against T. cruzi, L. chagasi, and L. amazonensis and antimicrobial activity against S. aureus, E. coli, P. aeruginosa, and C. albicans. The phytochemical screening revealed coumarins, terpenes/sterols, and flavonoids in the ethanolic extract. In addition, the coumarin identified as ayapin was isolated from this extract. We also performed in silico prediction of potential biological activities and targets for compounds previously found in A. fastigiatum. Several predictions were confirmed both retrospectively and prospectively by experimental results described here or elsewhere. Some activities described in the in silico target fishing approach were validated by the ethnopharmacological use and known biological properties. Some new activities and/or targets were predicted and could guide future studies. These results suggest that A. fastigiatum can be an interesting source of substances with antiparasitic and antimicrobial activities.
Subject(s)
Ageratum , Computer Simulation , Escherichia coli , Microbial Sensitivity Tests , Phytochemicals/pharmacology , Plant Extracts/pharmacology , Retrospective Studies , Staphylococcus aureusABSTRACT
The diagnosis of canine visceral leishmaniasis (CVL) has been a problem for public health services due to the variety of clinical signs similar to other diseases and low sensitivity and specificity of available tests. In this sense, our main objective was to develop a simple, rapid, and accurate quantitative real-time PCR (qPCR) diagnosis for CVL. Thus, low-invasive samples from bone marrow (BM), popliteal lymph nodes (PLN), and conjunctival swabs (CS) were selected from negative and VL-positive dogs, using as gold standard, immunological and parasitological tests performed with different tissues. Oligonucleotides for Leishmania infantum kDNA were designed and the limit of quantification and amplification efficiency of the qPCR were determined using tissue-specific standards produced with DNA from those different tissues, mixed with DNA from a known amount of L. infantum promastigotes. Endogenous control was used to validate a comparative Ct method, and tissue parasite concentrations were estimated by comparison with tissue-specific reference standard samples. The overall analysis of the qPCR data suggests the following ranking for tissue choice: PLN > BM > CS. Finally, we have concluded that this molecular approach simplifies and accelerates the quantitative diagnostic process because it is easy to perform, requiring no DNA dosing or standard curve application, and it shows good diagnostic parameters, especially when using popliteal lymph node samples.
Subject(s)
Dog Diseases/diagnosis , Leishmania infantum/genetics , Leishmaniasis, Visceral/diagnosis , Leishmaniasis, Visceral/veterinary , Real-Time Polymerase Chain Reaction/methods , Animals , Bone Marrow/parasitology , DNA, Kinetoplast/genetics , Dog Diseases/parasitology , Dogs , Leishmaniasis, Visceral/parasitology , Lymph Nodes/parasitology , Molecular Diagnostic Techniques/methods , Real-Time Polymerase Chain Reaction/veterinary , Sensitivity and Specificity , Spleen/parasitologyABSTRACT
Aim: Cysteine proteases are important molecular targets involved in the replication, virulence and survival of parasitic organisms, including Trypanosoma and Leishmania species. Methodology & results: Analogs of the 7-chloro-N-[3-(morpholin-4-yl)propyl]quinolin-4-amine were synthesized and their inhibitory activity against the enzymes cruzain and rhodesain as well as against promastigotes forms of Leishmania species and epimastigotes forms of Trypanosoma cruzi were evaluated. Five compounds showed activity against both enzymes with half maximal inhibitory concentration (IC50) values ranging from 23 to 123 µM. Among these, compounds 3 and 4 displayed leishmanicidal activity; compound 4 was the most promising with IC50 values <10 µM and no cytotoxicity for uninfected cells. Conclusion: The results obtained indicate that cysteine proteases are likely to be the molecular target of compounds 3 and 4.
Subject(s)
Antiprotozoal Agents/pharmacology , Cysteine Endopeptidases/metabolism , Cysteine Proteinase Inhibitors/pharmacology , Protozoan Proteins/antagonists & inhibitors , Quinolines/pharmacology , Antiprotozoal Agents/chemical synthesis , Antiprotozoal Agents/chemistry , Cysteine Proteinase Inhibitors/chemical synthesis , Cysteine Proteinase Inhibitors/chemistry , Leishmania/drug effects , Molecular Docking Simulation , Molecular Structure , Parasitic Sensitivity Tests , Protozoan Proteins/metabolism , Quinolines/chemical synthesis , Quinolines/chemistry , Trypanosoma cruzi/drug effectsABSTRACT
BACKGROUND: Multifunctional l-amino acid oxidases (LAAOs) occur widely in snake venoms. METHODS: The l-AAO from Bothrops leucurus (Bl-LAAO) venom was purified using a combination of molecular exclusion and ion-exchange chromatographies. We report some biochemical features of Bl-LAAO associated with its effect on platelet function and its cytotoxicity. RESULTS: Bl-LAAO is a 60kDa monomeric glycoprotein. Its N-terminal sequence shows high homology to other members of the snake-venom LAAO family. Bl-LAAO catalyzes oxidative deamination of l-amino acids with the generation of H2O2. The best substrates were: l-Met, l-Norleu, l-Leu, l-Phe and l-Trp. The effects of snake venom LAAOs in hemostasis, especially their action on platelet function remain largely unknown. Bl-LAAO dose-dependently inhibited platelet aggregation of both human PRP and washed platelets. Moreover, the purified enzyme exhibited a killing effect in vitro against Leishmania sp., promastigotes, with a very low EC(50) of 0.07µM. Furthermore, the cytotoxicity of Bl-LAAO was observed in the stomach cancer MKN-45, adeno carcinoma HUTU, colorectal RKO and human fibroblast LL-24 cell lines. The enzyme released enough H2O2 in culture medium to induce apoptosis in cells in a dose- and time-dependent manner. The biological effects were inhibited by catalase. CONCLUSION: Bl-LAAO, a major component of B. leucurus venom, is a cytotoxin acting primarily via the generation of high amounts of H2O2 which kill the cells. GENERAL SIGNIFICANCE: These results allow us to consider the use of LAAOs as anticancer agents, as tools in biochemical studies to investigate cellular processes, and to obtain a better understanding of the envenomation mechanism.
Subject(s)
Apoptosis/drug effects , L-Amino Acid Oxidase/pharmacology , Platelet Aggregation/drug effects , Snake Venoms/enzymology , Amino Acid Sequence , Animals , Bothrops/metabolism , Cell Line , Cell Line, Tumor , Cell Survival/drug effects , Dose-Response Relationship, Drug , Electrophoresis, Gel, Two-Dimensional , Enzyme Stability , Humans , Hydrogen Peroxide/metabolism , Hydrogen-Ion Concentration , L-Amino Acid Oxidase/genetics , L-Amino Acid Oxidase/metabolism , Leishmania braziliensis/drug effects , Leishmania braziliensis/growth & development , Molecular Sequence Data , Substrate Specificity , TemperatureABSTRACT
O enfisema cérvico-facial é raramente descrito na lieratura como complicaçäo de procedimento dentário. Este artigo refere-se a um relato com ampla revisäo, de um paciente que após tratamento dentário desenvolveu quadro de enfisema cérvico-facial, progredindo para pneumomediastino e mediastinte, sendo esta última uma complicaçäo rara e extremamente grave. O diagnóstico foi feito por exames de radiografias simples e tomografia computadorizada. A paciente desenvolveu quadro de empiema pleural e septcemia, evoluindo para o óbito no 12º. dia após o tratamento dentário
Subject(s)
Humans , Female , Adult , Mediastinal Emphysema , Tooth Extraction/adverse effectsABSTRACT
Os autores descrevem um caso de atresia brônquica em paciente do sexo masculino, 24 anos de idade, assintomático. O diagnóstico foi estabelecido em exame admissional, no qual a radiografia simples de tórax apresentava 2 nódulos com densidade de partes moles e área de hipertransparência periférica. A tomografia computadorizada confirmou os achados da radiologia convencional, evidenciando nódulos de baixa densidade e com heperaeraçäo regional. Uma revisäo sobre os achados clínicos e radiológicos dessa malformaçäo rara é apresentada
Subject(s)
Humans , Male , Adult , Mucocele/diagnosis , Pulmonary Atresia/diagnosis , Tomography, X-Ray Computed/statistics & numerical data , Pulmonary Atresia/etiology , Pulmonary Atresia/physiopathologyABSTRACT
Os autores esttudaram alteraçöes oculares em fetos de ratos submetidos à açäo da hipervitaminose "A". Concluiram que ocorreram alteraçöes oculares variadas, sendo mais conspícuas ao nível do cristalino e da retina. Discutem possíveis mecanismos de açäo da hipervitaminose "A" e advertem quanto aos riscos de emprego em gestantes, quando agiria como um teratógeno inespecífico, produzindo alteraçöes maiores ou menores, conforme a dose empregada e o tempo da gestaçäo
Subject(s)
Animals , Pregnancy , Guinea Pigs , Rats , Abnormalities, Drug-Induced , Eye Abnormalities/chemically induced , Hypervitaminosis A/complications , Hypervitaminosis A/etiology , Lens, Crystalline/abnormalities , Retina/abnormalities , Teratogens , Vitamin A/adverse effects , Vitamin A/toxicityABSTRACT
Os autores apresentam relato de caso familiar de onico-osteodistrofia, acometendo a mäe e seus dois filhos menores, na qual se observam todas as lateraçöes caracteristicas da síndrome, a exceçäo da proteinúria. Na menor J.D.S. (1ª filha), foi feito estudo tomográfico do quadril, que mostrou marcante anteversäo femoral, associada com as alteraçöes próprias da síndrome
Subject(s)
Infant , Adult , Humans , Male , Female , Bone and Bones/pathology , Nail-Patella Syndrome , Elbow , Hip , Knee , Tomography, X-Ray ComputedABSTRACT
Os autores apresentam um caso de fibroma ossificante de seio maxilar e fossa nasal, discutindo os aspectos clínicos radiológicos e anatomopatológicos. O diagnóstico é difícil, devido às características clínicas diversas e a eventuais controvérsias na classificaçäo anatomopatológica. O tratamento é cirúrgico, e neste caso foi realizada sinusectomia maxilar com técnica de Caldwell-Luc e micro-cirurgia endonasal e transmaxilar
