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1.
Rev Soc Bras Med Trop ; 53: e20190477, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32049205

RESUMO

INTRODUCTION: Benznidazole (BZL) and Nifurtimox (NFX) are the pharmacological treatment for acute phase Chagas Disease (CD); however, therapy resistance and residual mortality development remain important unresolved issues. Posaconazole (POS) has shown a trypanocidal effect in vivo and in vitro. Thus, this study aimed at comparing the T. Cruzi parasitic load-reducing effect of the combination of BZL+POS against that of monotherapy with either, during acute phase CD, in an experimental murine model. METHODS: Nineteen Wistar rats were randomly allocated to four groups and inoculated with the trypomastigotes of T. cruzi strain´s JChVcl1. The rats were administered anti-parasites from day 20-29 post-infection. The Pizzi and Brener method was used for parasitemia measurement. Longitudinal data analysis for the continuous outcome of repeated measures was performed using parasitemia as the outcome measured at days 20, 22, 24, 27, and 29 post-infection. RESULTS: All four groups had similar parasitic loads (p=0.143) prior to therapy initiation. Among the three treatment groups, the BZL+POS (n=5) group showed the highest mean parasitic load reduction (p=0.000) compared with the control group. Likewise, the BZL+POS group rats showed an earlier therapeutic effect and were the only ones without parasites in their myocardial samples. CONCLUSIONS: Treatment of acute phase CD with BZL+POS was more efficacious at parasitemia and myocardial injury reduction, compared with monotherapy with either.


Assuntos
Doença de Chagas/tratamento farmacológico , Nitroimidazóis/administração & dosagem , Parasitemia/tratamento farmacológico , Triazóis/administração & dosagem , Tripanossomicidas/administração & dosagem , Doença Aguda , Animais , DNA de Protozoário , Modelos Animais de Doenças , Progressão da Doença , Quimioterapia Combinada , Carga Parasitária , Ratos , Ratos Wistar
2.
Rev Soc Bras Med Trop ; 52: e20180541, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31800918

RESUMO

INTRODUCTION: Chagas disease is a major public health problem that is endemic in Brazil and Latin America. This study aimed to determine the socioeconomic, demographic, and clinical characteristics of 171 patients (mean age, 45 years; female, 65%) with Chagas disease at Hospital Universitário de Brasília, Federal District, Brazil. METHODS: We implemented this cross-sectional study using a clinical epidemiological questionnaire, electrocardiography, echocardiography, and quantitative detection of Trypanosoma cruzi DNA in blood using qRT-PCR. RESULTS: Among the patients, 26.3% had a full elementary education, and 13.2% were illiterate. Most (63.6%) were economically classified as class C, and 51.5% were born in Bahia state. A total of 62.0% participants reported previous contact with the triatomine bug. The clinical forms of the disease were indeterminate (69.51%), cardiac (15.24%), digestive (10.37%), and mixed (4.88%). The most common electrocardiographic abnormality was complete right bundle branch block in association with a divisional anterosuperior block. Only 14.6% of the patients complied with benznidazole medication for at least 60 days, and 164 of them were assessed by echocardiography. The parasite load was positive in 56% of the patients. CONCLUSIONS: Chagas disease affected mostly women, with the indeterminate chronic form of the disease.


Assuntos
Doença de Chagas/epidemiologia , Trypanosoma cruzi/genética , Adulto , Idoso , Brasil/epidemiologia , Doença de Chagas/parasitologia , Estudos Transversais , DNA de Protozoário/genética , Ecocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Carga Parasitária , Reação em Cadeia da Polimerase em Tempo Real , Fatores Socioeconômicos , Trypanosoma cruzi/isolamento & purificação , Adulto Jovem
3.
Vet Parasitol ; 276: 108964, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31698093

RESUMO

Parasites induce behavioral changes in the host and obesity is a health problem affecting different animal species. Cysticercosis caused by Taenia pisiformis affects some behavior of rabbits and reproductive behavior of does. Rabbits do not escape from metabolic disorders, being long-live animals useful in breeding, research and companion animals. Here, we addressed the interaction between parasitosis and obesity, and studied how these conditions or the comorbidity affect behavioral and productive parameters in bucks infected with 3000 T. pisiformis eggs. We found that the chronic infection reduced locomotor activity by 28.5% in obese, 18.5% in infected and 47% in obese-infected group (comorbid). The exploratory activity reduced by 42% in obese, 48% in infected and 68% in comorbid rabbits (P ≤ 0.001). Chinning was not affected by obesity, while infection decreased it by 25%. Behavioral reproductive parameters like response time, the mount latency and number of ejaculates were affected by infection and obesity. Furthermore, obesity seems to increase the parasite load promoting the formation of liver granulomas (16% granulomas compared with normal weight), with a higher number of cysticerci in obese animals (86% more than normal weight). Infection decreases body weight, body mass index and the zoometric index BW/LV in obese and normal weight rabbits. In conclusion, infection with T. pisiformis altered behavioral and productive parameters, and obesity magnifies the impact caused by the infection. Also, obesity leads to major susceptibility to infection with T. pisiformis.


Assuntos
Cisticercose/complicações , Obesidade/complicações , Animais , Comportamento Animal , Glicemia/análise , Índice de Massa Corporal , Peso Corporal , Cisticercose/fisiopatologia , Comportamento Exploratório , Locomoção , Masculino , Obesidade/fisiopatologia , Carga Parasitária , Coelhos , Distribuição Aleatória , Sêmen , Comportamento Sexual Animal
4.
Exp Parasitol ; 207: 107789, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31669169

RESUMO

American visceral leishmaniasis is caused by the protozoan Leishmania infantum. The control of the disease depends on the magnitude of the Th1 cell response and IL-10 producing regulatory T cells. Administration of chemokine, such as CXCL10, has shown promising results in the leishmaniasis treatment. Previous studies from our group have shown that CXCL10 induces a reduction in parasite burden in the spleen and a decrease in IL-10 and TGF-ß production in L. infantum-infected BALB/c mice. This work investigated whether CXCL10-treatment reduces IL-10 + Treg cell populations (CD4+CD25+Foxp3+ and Tr1) and induces morphological changes in the spleen. BALB/c mice were infected and treated or not with CXCL10 on the 1st, 3rd and 7th days of infection. CXCL10-treatment was able to reduce the parasite load in the spleen in L. infantum-infected BALB/c mice and this decrease in the number of parasites correlated with the decrease in size of this organ in treated animals compared to untreated animals. 7, 23, and 45 days post-treatment (p.t.), the phenotype and frequency of IL-10 + Treg cells were evaluated by flow cytometry, and the morphological changes of the spleen were analyzed by optical microscopy. After 7 and 23 days p.t., CXCL10-treated animals showed a significant reduction of CD25-Foxp3-IL-10+ (Tr1) cells in the spleen when compared to untreated animals, whereas CD4+CD25+Foxp3+IL-10+ Treg cells reduced later at 23rd and 45th days p.t. Furthermore, while untreated animals showed a significant positive correlation between IL-10 production and Tr1 cells, in CXCL10-treated group this correlation was negative. Thus, these findings show that treatment with CXCL10 chemokine in L. infantum-infected BALB/c mice results in suppression of IL10+ Treg (Foxp3+ and Tr1) cells in the spleen, associated with a reduction in parasite load and splenomegaly.


Assuntos
Quimiocina CXCL10/uso terapêutico , Leishmaniose Visceral/tratamento farmacológico , Leishmaniose Visceral/imunologia , Baço/imunologia , Linfócitos T Reguladores/efeitos dos fármacos , Adjuvantes Imunológicos/uso terapêutico , Animais , Quimiocina CXCL10/administração & dosagem , Quimiocina CXCL10/farmacologia , Cricetinae , Citometria de Fluxo , Fatores de Transcrição Forkhead/imunologia , Humanos , Injeções Intraperitoneais , Leishmania infantum/efeitos dos fármacos , Leishmania infantum/imunologia , Leishmania infantum/patogenicidade , Masculino , Mesocricetus , Camundongos , Camundongos Endogâmicos BALB C , Tamanho do Órgão/efeitos dos fármacos , Tamanho do Órgão/imunologia , Carga Parasitária , Baço/parasitologia , Baço/patologia , Linfócitos T Reguladores/imunologia , Virulência
5.
Vet Parasitol ; 276: 108976, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31739256

RESUMO

Cutaneous leishmaniosis (CL) is a parasitic disease in animals and human with no satisfactory treatments and vaccination. Rapamycin is a potent inhibitor of mammalian target of rapamycin (mTOR) with various applications. Here, the effect of rapamycin alone or in combination with two other drugs, namely amphotericin B (AmB) and glucantime, was investigated against Leishmania tropica infection. In vitro viability and electron microscopy evaluation of the parasites showed detrimental changes in their appearance and viability. Treatment with clinically relevant dose of rapamycin (10.2 µg/dose) is able to control the parasite load in BALB/c mice infected with L. tropica. Furthermore, the cytokine profiles showed significant polarization towards Th1 immune response. Surprisingly, combination therapy with either AmB or glucantime was not efficient. Rapamycin is showed an effective alternative therapy against leishmaniosis caused by L. tropica.


Assuntos
Antiprotozoários/uso terapêutico , Leishmania tropica/efeitos dos fármacos , Leishmaniose Cutânea/tratamento farmacológico , Sirolimo/uso terapêutico , Anfotericina B/farmacologia , Anfotericina B/uso terapêutico , Animais , Antiprotozoários/farmacologia , Linhagem Celular Tumoral , Citocinas/análise , Feminino , Humanos , Concentração Inibidora 50 , Leishmania tropica/crescimento & desenvolvimento , Leishmania tropica/ultraestrutura , Leishmaniose Cutânea/prevenção & controle , Linfonodos/parasitologia , Antimoniato de Meglumina/farmacologia , Antimoniato de Meglumina/uso terapêutico , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Carga Parasitária , Distribuição Aleatória , Sirolimo/farmacologia , Serina-Treonina Quinases TOR/efeitos dos fármacos
6.
Parasitol Res ; 118(12): 3399-3408, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31655904

RESUMO

Schistosomiasis is a neglected chronic parasitic disease with a significant lasting morbidity. Currently, praziquantel (PZQ) is the most efficient drug for schistosomiasis worldwide. However, the possibility of the occurrence of resistance to PZQ is increasing. Therefore, there is a vital need to find new antischistosomal drugs or to increase the efficacy of the existing ones. Omeprazole is a proton pump inhibitor which is reported to have antiparasitic properties. Thus, the aim of this study was to assess the potential therapeutic effects of omeprazole in experimental Schistosoma mansoni infection either alone or in combination with PZQ. For this aim, 80 laboratory bred mice were divided into 3 groups; uninfected control, infected untreated control, and infected and treated at tenth week P.I. The last group was divided into three subgroups that received either PZQ alone, omeprazole alone, or both drugs. The effectiveness of treatment was assessed by adult worm counts, liver egg count, scanning electron microscopy of adult worms, histopathological, and immunohistochemical (GFAP) examination. There was significant reduction of adult worm counts, liver egg counts, size, diameter of hepatic granulomas, hepatic fibrosis, and GFAP expression in the group that received combined treatment as compared to PZQ group. Moreover, the tegumental changes were more evident in the group that received combined treatment. In conclusion, the administration of omeprazole with PZQ improved the efficacy of PZQ in the treatment of Schistosomiasis mansoni.


Assuntos
Omeprazol/uso terapêutico , Praziquantel/uso terapêutico , Inibidores da Bomba de Prótons/uso terapêutico , Schistosoma mansoni/efeitos dos fármacos , Esquistossomose mansoni/tratamento farmacológico , Esquistossomicidas/uso terapêutico , Animais , Quimioterapia Combinada , Granuloma/parasitologia , Cirrose Hepática/parasitologia , Masculino , Camundongos , Contagem de Ovos de Parasitas , Carga Parasitária , Esquistossomose mansoni/parasitologia
7.
Infect Immun ; 87(12)2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31570557

RESUMO

Neurocysticercosis is caused by the establishment of Taenia solium cysts in the central nervous system. Murine cysticercosis by Taenia crassiceps is a useful model of cysticercosis in which the complement component 5 (C5) has been linked to infection resistance/permissiveness. This work aimed to study the possible relevance for human neurocysticercosis of single nucleotide polymorphisms (SNPs) in the C5-TRAF1 region (rs17611 C/T, rs992670 G/A, rs25681 G/A, rs10818488 A/G, and rs3761847 G/A) in a Mexican population and associated with clinical and radiological traits related to neurocysticercosis severity (cell count in the cerebrospinal fluid [CSF cellularity], parasite location and parasite load in the brain, parasite degenerating stage, and epilepsy). The AG genotype of the rs3761847 SNP showed a tendency to associate with multiple brain parasites, while the CT and GG genotypes of the rs17611 and rs3761847 SNPs, respectively, showed a tendency to associate with low CSF cellularity. The rs3761847 SNP was associated with epilepsy under a dominant model, whereas rs10818488 was associated with CSF cellularity and parasite load under dominant and recessive models, respectively. For haplotypes, C5- and the TRAF1-associated SNPs were, respectively, in strong linkage disequilibrium with each other; thus, these haplotypes were studied independently. For C5 SNPs, carrying the CAA haplotype increases the risk of showing high CSF cellularity 3-fold and the risk of having extraparenchymal parasites 4-fold, two conditions that are related to severe disease. For TRAF1 SNPs, the GA and AG haplotypes were associated with CSF cellularity, and the AG haplotype was associated with epilepsy. Overall, these findings support the clear participation of C5 and TRAF1 in the risk of developing severe neurocysticercosis in the Mexican population.


Assuntos
Complemento C5/genética , Epilepsia/parasitologia , Predisposição Genética para Doença/genética , Neurocisticercose/genética , Fator 1 Associado a Receptor de TNF/genética , Adolescente , Adulto , Idoso , Animais , Encéfalo/parasitologia , Líquido Cefalorraquidiano/parasitologia , Epilepsia/genética , Feminino , Haplótipos/genética , Humanos , Masculino , México , Pessoa de Meia-Idade , Neurocisticercose/parasitologia , Carga Parasitária , Polimorfismo de Nucleotídeo Único/genética , Taenia solium/patogenicidade , Adulto Jovem
8.
Infect Immun ; 87(12)2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31570561

RESUMO

Theileria parva is the causative agent of East Coast fever (ECF), a tick-borne disease that kills over a million cattle each year in sub-Saharan Africa. Immune protection against T. parva involves a CD8+ cytotoxic T cell response to parasite-infected cells. However, there is currently a paucity of knowledge regarding the role played by innate immune cells in ECF pathogenesis and T. parva control. Here, we demonstrate an increase in intermediate monocytes (CD14++ CD16+) with a concomitant decrease in the classical (CD14++ CD16-) and nonclassical (CD14+ CD16+) subsets at 12 days postinfection (dpi) during lethal infection but not during nonlethal T. parva infection. Ex vivo analyses of monocytes demonstrated upregulation of interleukin-1 beta (IL-1ß) and tumor necrosis factor alpha (TNF-α) mRNA and increased nitric oxide production during T. parva lethal infection compared to nonlethal infection at 10 dpi. Interestingly, no significant differences in peripheral blood parasite loads were observed between lethally and nonlethally infected animals at 12 dpi. In vitro stimulation with T. parva schizont-infected cells or Escherichia coli lipopolysaccharide (LPS) resulted in significant upregulation of IL-1ß production by monocytes from lethally infected cattle compared to those from nonlethally infected animals. Strikingly, monocytes from lethally infected animals produced significant amounts of IL-10 mRNA after stimulation with T. parva schizont-infected cells. In conclusion, we demonstrate that T. parva infection leads to alterations in the molecular and functional phenotypes of bovine monocytes. Importantly, since these changes primarily occur in lethal infection, they can serve as biomarkers for ECF progression and severity, thereby aiding in the standardization of protection assessment for T. parva candidate vaccines.


Assuntos
Monócitos/imunologia , Theileria parva/imunologia , Theileriose/imunologia , Animais , Bovinos , Interleucina-10/genética , Interleucina-10/imunologia , Interleucina-1beta/genética , Interleucina-1beta/imunologia , Lipopolissacarídeos/imunologia , Carga Parasitária , Vacinas Protozoárias/imunologia , RNA Mensageiro/genética , Linfócitos T Citotóxicos/imunologia , Theileriose/parasitologia , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/imunologia
9.
Ann Parasitol ; 65(3): 275-279, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31599555

RESUMO

Eighty nine rats, Arvicanthis niloticus, were collected from the horticultural fields of Shendi area in Sudan, between January and June 2018, and examined for the first time for helminth parasites. Thirty seven (41.6%) of the collected rats were infected, with an overall mean intensity of 4.4 helminths per a rat. A total of 6 helminth species were identified including three nematodes (Nippostrongylus brasiliensis, Monanema nilotica and Capillaria hepatica) and three cestodes (Hymenolepis diminuta, H. nana and Taenia taeniae formis). The most prevalent helminth was found to be the nematode, N. brasiliensis (21.3%), followed by the cestode, H. diminuta (10.1%), while the least was the nematode, C. hepatica (1.1%). Higher prevalence and intensity of infection were observed among older rats. Likewise, male rats were found to harbor a higher prevalence and intensity of infection. In conclusion, the rat, A. niloticus in Shendi area has found to be parasitized by various species of helminths, which some are of zoonotic importance, thus, any possible contact between this rat and humans or their pets may pose potential risk to public health.


Assuntos
Helmintíase Animal , Helmintos , Doenças dos Roedores , Animais , Helmintíase Animal/epidemiologia , Helmintíase Animal/parasitologia , Humanos , Masculino , Carga Parasitária , Ratos , Fatores de Risco , Doenças dos Roedores/parasitologia , Sudão/epidemiologia , Zoonoses/epidemiologia
10.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 31(4): 423-426, 2019 Sep 19.
Artigo em Chinês | MEDLINE | ID: mdl-31612680

RESUMO

OBJECTIVE: To evaluate the effects of intravenous injection of different blood components containing Babesia microti on B. microti infection in mice. METHODS: Healthy mice were infected with B. microti, and then blood samples were collected from the mouse orbit to prepare whole blood, serum-free blood components and pure red blood cells containing B. microti. Twenty seven BALB/c mice were divided into three groups, including the whole blood group, the serum-free blood component group and the pure red blood cell group, of 9 mice in each group, and then, each group was divided into three subgroups, of 3 mice in each subgroup, which were injected with 100 µL of blood components containing B. microti at concentrations of 9.00, 0.90, 0.09 B. microti parasites/µL (900, 90, 9 B. microti parasites) via the tail vein, respectively. Blood samples were collected from the mouse tail tip every other day since one day post-injection to prepare thin blood smears. Following Giemsa staining of blood smears, B. microti infection was identified in red blood cells using microscopy. RESULTS: Following injection of 900 B. microti parasites, B. microti was identified in the peripheral blood in the whole blood group and the serum-free blood component group 3 days post-injection, and the density of B. microti parasites started to increase 15 days post-injection and peaked 21 days post-injection, with 2.21% and 1.76% rates of B. microti infection in red blood cells, respectively. Subsequently, the density of B. microti parasites declined, and the percentage of B. microti infection in red blood cells tended to be 0 31 days post-injection. During the study period, no B. microti was found in the peripheral blood in the pure red blood cell group. Following injection of 90 B. microti parasites, B. microti was identified in the peripheral blood in the whole blood group 3 days post-injection, and the density of B. microti parasites increased 15 days post-injection and peaked 21 days post-injection, with a 1.35% rate of B. microti infection in red blood cells, while the percentage of B. microti infection in red blood cells tended to be 0 31 days post-injection. During the study period, no B. microti was detected in the peripheral blood in the serum-free blood component group or the pure red blood cell group. Following injection of 9 B. microti parasites, no B. microti was detected in the peripheral blood in the whole blood group, the serum-free blood component group or the pure red blood cell group. CONCLUSIONS: Blood components and dose of B. microti parasites may affect intravenous injection of B. microti injection in mice, and transfusion of blood components may case a risk of Babesia infection.


Assuntos
Babesia microti , Babesiose , Transfusão de Componentes Sanguíneos , Animais , Babesiose/sangue , Babesiose/transmissão , Transfusão de Componentes Sanguíneos/efeitos adversos , Eritrócitos/parasitologia , Camundongos , Camundongos Endogâmicos BALB C , Carga Parasitária , Fatores de Tempo
11.
PLoS Negl Trop Dis ; 13(10): e0007767, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31652261

RESUMO

OBJECTIVE: To evaluate the efficacy of a synthetic sex-aggregation pheromone of the sand fly vector Lu. longipalpis, co-located with residual insecticide, to reduce the infection incidence of Leishmania infantum in the canine reservoir. METHODS: A stratified cluster randomised trial was designed to detect a 50% reduction in canine incident infection after 24 months in 42 recruited clusters, randomly assigned to one of three intervention arms (14 cluster each): synthetic pheromone + insecticide, insecticide-impregnated dog collars, or placebo control. Infection incidence was measured by seroconversion to anti-Leishmania serum antibody, Leishmania parasite detection and canine tissue parasite loads. Changes in relative Lu. longipalpis abundance within households were measured by setting three CDC light traps per household. RESULTS: A total 1,454 seronegative dogs were followed-up for a median 15.2 (95% C.I.s: 14.6, 16.2) months per cluster. The pheromone + insecticide intervention provided 13% (95% C.I. 0%, 44.0%) protection against anti-Leishmania antibody seroconversion, 52% (95% C.I. 6.2%, 74·9%) against parasite infection, reduced tissue parasite loads by 53% (95% C.I. 5.4%, 76.7%), and reduced household female sand fly abundance by 49% (95% C.I. 8.2%, 71.3%). Variation in the efficacy against seroconversion varied between trial strata. Equivalent protection attributed to the impregnated-collars were 36% (95% C.I. 14.4%, 51.8%), 23% (95% C.I. 0%, 57·5%), 48% (95% C.I. 0%, 73.4%) and 43% (95% C.I. 0%, 67.9%), respectively. Comparison of the two interventions showed no statistically consistent differences in their efficacies; however, the errors were broad for all outcomes. Reductions in sand fly numbers were predominant where insecticide was located (chicken and dog sleeping sites), with no evidence of insecticide-induced repellence onto humans or dogs. CONCLUSION: The synthetic pheromone co-located with insecticide provides protection particularly against canine L. infantum parasite transmission and sand fly vector abundance. The effect estimates are not dissimilar to those of the insecticide-impregnated collars, which are documented to reduce canine infection incidence, human infection and clinical VL disease incidence, in different global regions. The trialled novel lure-and-kill approach is a low-cost potential vector control tool against ZVL in the Americas.


Assuntos
Doenças do Cão/prevenção & controle , Inseticidas/farmacologia , Leishmania infantum/efeitos dos fármacos , Leishmaniose Visceral/prevenção & controle , Psychodidae/metabolismo , Atrativos Sexuais/metabolismo , Atrativos Sexuais/farmacologia , Animais , Brasil , Controle de Doenças Transmissíveis/métodos , Reservatórios de Doenças , Doenças do Cão/epidemiologia , Doenças do Cão/parasitologia , Doenças do Cão/transmissão , Cães , Feminino , Humanos , Incidência , Leishmaniose Visceral/epidemiologia , Leishmaniose Visceral/transmissão , Leishmaniose Visceral/veterinária , Masculino , Carga Parasitária , Controle de Pragas/métodos , Inquéritos e Questionários
12.
Parasit Vectors ; 12(1): 444, 2019 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-31506088

RESUMO

BACKGROUND: Moxidectin has previously shown limited efficacy (≤ 44.4%) against confirmed macrocyclic lactone (ML)-resistant Dirofilaria immitis strains at 3 µg/kg after single and multiple oral dosages. Three studies were conducted to evaluate higher oral moxidectin doses for efficacy against confirmed ML-resistant D. immitis strains. METHODS: Dogs were inoculated with 50 D. immitis L3 and randomly allocated to treatments. Study 1: 6 groups of dogs (n = 8) were inoculated with JYD-34 (Day - 30) and treated as follows: T01, negative control; T02-T05, moxidectin at 3, 6, 12 or 24 µg/kg, respectively, on Day 0 only; T06, moxidectin at 3 µg/kg on Days 0, 30 and 60. Study 2: 10 groups of dogs (n = 5) were inoculated (Day - 30) with either JYD-34 (T01, T03-05) or ZoeLA (T02, T06-T10) and treated as follows: T01 and T02, negative controls; T03-T05, moxidectin at 24, 40 or 60 µg/kg, respectively, on Days 0, 28 and 56; T06 and T09, moxidectin at 3 or 60 µg/kg on Day 0 only; T07, T08 and T10, moxidectin at 24, 40 or 60 µg/kg, respectively, on Days 0, 28 and 56. Study 3: 5 groups of dogs (n = 5) were inoculated with ZoeMO (Day - 28) and treated as follows: T01, negative control; T02, moxidectin at 3 µg/kg moxidectin on Day 0 only; T03-T05, moxidectin at 24, 40 or 60 µg/kg, respectively, on Days 0, 28 and 56. All dogs were necropsied for adult heartworm recovery ~ 4-5 months post-inoculation. RESULTS: All moxidectin-treated dogs showed significantly lower worm counts than controls. The efficacy of moxidectin administered once at 3 µg/kg was 19% (JYD-34), 44.4% (ZoeLA) and 82.1% (ZoeMO). Increasing both the dose and the number of dosages of moxidectin improved efficacy, with 100% protection obtained using three dosages of moxidectin at either 40 µg/kg (JYD-34, ZoeMO) or 60 µg/kg (ZoeLA). Three dosages of 24 µg/kg were also highly effective, providing ≥ 98.8% efficacy for all three strains. CONCLUSIONS: Increasing both the dose and number of consecutive monthly dosages of moxidectin improved the efficacy against ML-resistant heartworms. Based on these data and other technical considerations, the 24 µg/kg dose was considered the optimal dose for further commercial development.


Assuntos
Antinematódeos/administração & dosagem , Quimioprevenção/métodos , Dirofilaria immitis/isolamento & purificação , Dirofilariose/prevenção & controle , Doenças do Cão/prevenção & controle , Macrolídeos/administração & dosagem , Administração Oral , Animais , Dirofilaria immitis/efeitos dos fármacos , Cães , Relação Dose-Resposta a Droga , Carga Parasitária , Resultado do Tratamento
13.
PLoS Negl Trop Dis ; 13(9): e0007226, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31536489

RESUMO

Chagas disease, caused by Trypanosoma cruzi, is a neglected tropical disease that affects 5-6 million people in endemic areas of the Americas. Presently, chemotherapy relies on two compounds that were proposed as trypanocidal drugs four decades ago: nifurtimox and benznidazole. Both drugs are able to eliminate parasitemia and to avoid seroconversion in infected people when used in the acute phase; however, their use in the chronic phase (the time when the majority of cases are diagnosed) is limited due to their serious side effects. Memantine is a glutamate receptor antagonist in the central nervous system of mammals that has been used for the treatment of Alzheimer's disease. Our group previously reported memantine as a trypanocidal drug that is able to induce apoptosis-like death in T. cruzi. In the present work, we further investigated the effects of memantine on the infection of RAW 264.7 macrophages and in vivo (in BALB/c mice). Here, we showed that memantine is able to diminish NO and Ca2+ entry in both LPS-activated and non-activated cells. These results, together with the fact that memantine was also able to reduce the infection of macrophages, led us to propose that this drug is able to activate a pro-oxidant non-NO-dependent cell defense mechanism. Finally, infected mice that were treated with memantine had diminished parasitemia, cardiac parasitic load, and inflammatory infiltrates. In addition, the treated mice had an increased survival rate. Taken together, these results indicate memantine to be a candidate drug for the treatment of Chagas disease.


Assuntos
Doença de Chagas/tratamento farmacológico , Memantina/farmacologia , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Animais , Cálcio/metabolismo , Doença de Chagas/parasitologia , Feminino , Coração/parasitologia , Lipopolissacarídeos/farmacologia , Macrófagos/parasitologia , Memantina/administração & dosagem , Camundongos , Camundongos Endogâmicos BALB C , Óxidos de Nitrogênio/metabolismo , Carga Parasitária , Parasitemia , Células RAW 264.7 , Receptores de N-Metil-D-Aspartato/antagonistas & inibidores , Tripanossomicidas/administração & dosagem
14.
Acta Trop ; 200: 105167, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31513762

RESUMO

It is not currently known which individuals with chronic Chagas disease (ChD) will develop cardiopathy in a determined period and which will be maintained asymptomatic with normal routine laboratory tests all their lives. The parasite burden is a factor that could explain this different evolution. The objective of this study was to quantify Trypanosoma cruzi burden by real-time PCR in blood (qPCR-B) and dejections of triatomines fed by xenodiagnosis (qPCR-XD) in 90 individuals with chronic ChD untreated, classified according to XD results and the presence or absence of cardiopathy. All individuals came from hyperendemic areas of Chile and participated in the study under Informed Consent. The standard qPCR curves for qPCR-B and qPCR-XD were elaborated with a mixture of known concentrations of T. cruzi strains, performing DNA serial dilutions (1/10) with a dynamic range between 105 and 10-1 parasite equivalents/mL. The TaqManⓇ detection system was applied in a Stratagene Mx3000P thermocycler (Agilent Technologies, USA) with cruzi 1 and cruzi 2 satellite primers. 22.2% and 15.6% of cases with cardiopathy or without cardiopathy were XD positive. There was no significant difference between the groups. The positivity of qPCR-B and qPCR-XD in the positive XD group was 82.35% and 100%, respectively, while in the negative XD group was 55.26% and 42.10%, respectively. A superior qPCR value in chronic ChD patients with and without cardiopathy was determined for qPCR in cases with positive XD and positive qPCR-XD. The receiver operating characteristic (ROC) curve analyses show better accuracy for detecting parasite burden (area under the curve, AUC) for qPCR-XD in comparison to qPCR-B. That is to say, major performance in DNA samples obtained of positive XD (gold standard for viable T. cruzi) detected and quantified by qPCR-XD. A high percentage of cases with XD and qPCR-XD positive (80-100%) have result concordant with qPCR-B. In absence of XD, future challenges are especially related to the low parasitic load of chronic ChD patients treated with trypanocidal drugs and post-therapy parasitological evaluations by qPCR-B. Finally, no statistically significant differences were found between presence or absence of cardiopathy and XD, qPCR-B or qPCR-XD.


Assuntos
Doença de Chagas/complicações , Doença de Chagas/parasitologia , Cardiopatias/etiologia , Carga Parasitária , Triatoma/parasitologia , Trypanosoma cruzi/isolamento & purificação , Xenodiagnóstico/métodos , Adulto , Fatores Etários , Idoso , Animais , Doença de Chagas/sangue , Doença de Chagas/epidemiologia , Chile/epidemiologia , Doença Crônica/epidemiologia , Testes Diagnósticos de Rotina , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase em Tempo Real/métodos , Tripanossomicidas , Trypanosoma cruzi/genética
15.
Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi ; 31(3): 299-300, 2019 Jul 24.
Artigo em Chinês | MEDLINE | ID: mdl-31544411

RESUMO

OBJECTIVE: To understand Clonorchis sinensis infections in cats in Nanning City, so as to provide evidence for the control of the reservoir host of C. sinensis. METHODS: The cat livers were purchased from cat slaughterhouses in Nanning City. The cat gallbladder and liver were dissected, and liver flukes were collected and counted. Then, the worms were subjected to morphological observation, amplification of the ITS2 gene and sequencing. The species of the worms were identified using BLAST. RESULTS: A total of 105 cat livers were collected from two cat slaughterhouses, and 68 were detected with C. sinensis infections, with an infection rate of 64.76%. The highest burden was 980 worms in a single liver, and the mean burden was 72 worms in a liver. There were 3 types of liver flukes with various size and morphology, and all were identified as C. sinensis by means of morphological observation, ITS2 gene amplification, sequencing and sequence alignment. CONCLUSIONS: There is a high infection rate of C. sinensi in marketed cats in Nanning City, and it is therefore suggested that targeted interventions should be intensified for the management of C. sinensis infections in cats.


Assuntos
Doenças do Gato , Clonorquíase , Clonorchis sinensis , Reservatórios de Doenças , Animais , Doenças do Gato/epidemiologia , Doenças do Gato/parasitologia , Gatos , China/epidemiologia , Clonorquíase/epidemiologia , Clonorquíase/parasitologia , Clonorquíase/veterinária , Clonorchis sinensis/anatomia & histologia , Clonorchis sinensis/genética , Reservatórios de Doenças/parasitologia , Fígado/parasitologia , Carga Parasitária , Prevalência
16.
Rev Bras Parasitol Vet ; 28(4): 760-763, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31483035

RESUMO

The aim of this study was to evaluate the efficacy of a single dose of oral afoxolaner in controlling fleas in cats. Fourteen cats were used. The cats were given identification numbers, housed individually, artificially infested with Ctenocephalides felis felis, and treated (or not) with afoxolaner. Were divided into a treatment group and a control group (n = 7/group), on the basis of the fleas count hours after an infestation applied on Day (one-by-one allocation after ordering by count). At the start of the experimental protocol (designated day 0), the treated group received afoxolaner in a single dose of 2.5 mg/kg and the control group animals received a placebo. All animals were infested with 100 C. felis felis fleas two days before day 0, as well as on days 5, 12, 19, 26, 33, 40, 47, 54, and 63, parasite loads being evaluated at 48 h after each infestation. The efficacy of afoxolaner was 100% on day 2 and remained above 98% until day 42, decreasing to 95.3% by day 63. The findings confirm that a single dose of oral afoxolaner was effective in controlling C. felis felis in cats, and there were no observed adverse events.


Assuntos
Antiparasitários/administração & dosagem , Doenças do Gato/parasitologia , Infestações por Pulgas/veterinária , Isoxazóis/administração & dosagem , Naftalenos/administração & dosagem , Animais , Estudos de Casos e Controles , Doenças do Gato/tratamento farmacológico , Gatos , Feminino , Infestações por Pulgas/tratamento farmacológico , Masculino , Carga Parasitária , Sifonápteros , Resultado do Tratamento
17.
BMC Res Notes ; 12(1): 615, 2019 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-31547842

RESUMO

OBJECTIVE: Histopathological studies suggest that parasite load is different between acute and chronic forms of cutaneous leishmaniasis (CL). However, highly sensitive detection methods are still needed to distinguish different forms of leishmaniasis. In the present study, we developed a quantitative real-time polymerase chain reaction (PCR) to detect and quantify Leishmania tropica parasites in paraffin-embedded tissue samples. RESULTS: The ability of real-time PCR for leishmania detection was higher than histopathological evaluation. The quantitative real-time PCR (qPCR) quantified parasite loads were highly correlated with microscopic results (r = 0.598; P < 0.001). Among patients, the parasite load was inversely correlated with disease duration (acute CL lesions had very higher parasite load than chronic CL lesions), but there was no difference in the parasite load according to the patients' age and sex as well as location of the lesions. In contrast to Ridley scoring system (P < 0.001), there were no statistically significant differences in the relative number of parasites among the lupoid and non-lupoid forms of chronic lesions in real-time PCR (P = 0.549), which indicates the superiority of histopathological evaluation for chronic forms differentiation.


Assuntos
DNA de Protozoário/genética , Leishmania tropica/genética , Leishmaniose Cutânea/diagnóstico , Pele/parasitologia , Doença Aguda , Adolescente , Adulto , Idoso , Criança , Doença Crônica , DNA de Protozoário/classificação , Diagnóstico Diferencial , Feminino , Histocitoquímica , Humanos , Leishmania tropica/classificação , Leishmaniose Cutânea/classificação , Leishmaniose Cutânea/parasitologia , Leishmaniose Cutânea/patologia , Masculino , Pessoa de Meia-Idade , Inclusão em Parafina , Carga Parasitária , Reação em Cadeia da Polimerase em Tempo Real , Pele/patologia
18.
Acta Trop ; 199: 105120, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31376368

RESUMO

Chagas disease has become a global health problem due to migration of infected people out of Latin America to non-endemic countries. For more than 40 years, only the nitroimidazole compounds Benznidazole and Nifurtimox, have been used for specific treatment of Trypanosoma cruzi infection with disappointing results, specially due to the long duration of treatment and adverse events in the chronic phase. In the last years, ergosterol inhibitors have been also proposed for specific treatment. Different randomized clinical trials were performed for evaluating their treatment efficacy and safety. One of the greatest concerns in clinical trials is to provide an early surrogate biomarker of response to trypanocidal chemotherapy. Serological response is slow and the classical parasitological tests have poor sensitivity and are time-consuming. Nowadays, PCR is the most helpful tool for assessing treatment response in a short period of time. Different protocols of PCR have been developed, being quantitative real time PCR based on amplification of repetitive satellite or minicircle DNA sequences plus an internal amplification standard, the mostly employed strategies in clinical trials. Standardized protocols and the use of an external quality assessment ensure adequate technical procedures and reliable data. Clinical trials have shown a significant reduction in parasite loads, reaching undetectable DNA levels in bloodstream after specific treatment, however events of treatment failure have also been reported. Treatment failure could be due to inadequate penetrance of the drugs into the affected tissues, to the presence of primary or secondary drug resistance of the infecting strains as well as to the existence of dormant parasite variants reluctant to drug action. The early diagnosis of drug resistance would improve clinical management of Chagas disease patients, allowing dictating alternative therapies with a combination of existing drugs or new anti-T. cruzi agents. The aim of this review was to describe the usefulness of detecting T.cruzi DNA by means of real time PCR assays, as surrogate biomarker in clinical trials for evaluating new drugs for CD or new regimens of available drugs and the possibility to detect treatment failure.


Assuntos
Doença de Chagas/terapia , Ácidos Nucleicos/análise , Reação em Cadeia da Polimerase em Tempo Real , Tripanossomicidas/uso terapêutico , Trypanosoma cruzi/efeitos dos fármacos , Biomarcadores , Doença de Chagas/parasitologia , Doença Crônica , Resistência a Medicamentos/genética , Humanos , Nifurtimox/farmacologia , Nifurtimox/uso terapêutico , Nitroimidazóis/farmacologia , Nitroimidazóis/uso terapêutico , Ácidos Nucleicos/sangue , Carga Parasitária , Falha de Tratamento , Resultado do Tratamento , Tripanossomicidas/farmacologia , Trypanosoma cruzi/genética
19.
Exp Parasitol ; 205: 107747, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31442454

RESUMO

Development of new chemotherapeutic agents is an essential issue in the treatment and control of a disease. This study aimed to evaluate the anti-leishmanial activity of amiodarone, an antiarrhythmic class III drug, against Leishmania major, the most prevalent etiological agent of cutaneous leishmaniasis in the old world. The proliferation of promastigotes and intracellular amastigotes in the absence or presence of amiodarone was estimated, in an in vitro study. For in vivo study, five weeks after infection of BALB/c mice with L. major, when the lesions appeared at the injection site, the mice were divided into four groups (n = 6 each); treatment was conducted for 28 consecutive days with vehicle, amiodarone at 40 mg/kg orally and glucantime at 60 mg/kg intraperitoneally. Therapy with amiodarone reduced the size of lesions compared to the untreated group after 12 days. Amiodarone decreased the parasite load and inflammatory responses, particularly the macrophages containing amastigotes, and enhanced granulation tissue formation in the dermis and subcutaneous area. The Tumor necrosis factor-α and Interleukin-6 levels were significantly lower in the cell culture supernatants of the inguinal lymph node in the amiodarone treated group compared to the vehicle and untreated groups. Amiodarone significantly increased the activity of glutathione peroxidase in comparison to the vehicle and untreated groups but did not affect the plasma levels of superoxide dismutase, malondialdehyde, adiponectin, and ferric reducing ability of plasma. Therefore, the anti- L. major activity and immunomodulatory effects of amiodarone reduced the parasitic load and enhanced wound healing in cutaneous leishmaniasis in BALB/c mice. Amiodarone reduced the lesion surface area, but it did not cure it completely.


Assuntos
Amiodarona/uso terapêutico , Antiprotozoários/uso terapêutico , Leishmania major/efeitos dos fármacos , Leishmaniose Cutânea/tratamento farmacológico , Adiponectina/sangue , Amiodarona/farmacologia , Animais , Antiarrítmicos/farmacologia , Antiarrítmicos/uso terapêutico , Antiprotozoários/farmacologia , Linhagem Celular , Feminino , Glutationa Peroxidase/metabolismo , Concentração Inibidora 50 , Interleucina-6/análise , Leishmania major/ultraestrutura , Leishmaniose Cutânea/parasitologia , Linfonodos/química , Linfonodos/imunologia , Macrófagos/parasitologia , Malondialdeído/sangue , Antimoniato de Meglumina/farmacologia , Antimoniato de Meglumina/uso terapêutico , Camundongos , Camundongos Endogâmicos BALB C , Carga Parasitária , Distribuição Aleatória , Pele/parasitologia , Pele/patologia , Pele/ultraestrutura , Superóxido Dismutase/metabolismo , Fator de Necrose Tumoral alfa/análise
20.
PLoS Negl Trop Dis ; 13(7): e0007602, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31365537

RESUMO

TGF-ß involvement in Chagas disease cardiomyopathy has been clearly demonstrated. The TGF-ß signaling pathway is activated in the cardiac tissue of chronic phase patients and is associated with an increase in extracellular matrix protein expression. The aim of this study was to investigate the effect of GW788388, a selective inhibitor of TßR1/ALK5, on cardiac function in an experimental model of chronic Chagas' heart disease. To this end, C57BL/6 mice were infected with Trypanosoma cruzi (102 parasites from the Colombian strain) and treated orally with 3mg/kg GW788388 starting at 120 days post-infection (dpi), when 100% of the infected mice show cardiac damage, and following three distinct treatment schedules: i) single dose; ii) one dose per week; or iii) three doses per week during 30 days. The treatment with GW788388 improved several cardiac parameters: reduced the prolonged PR and QTc intervals, increased heart rate, and reversed sinus arrhythmia, and atrial and atrioventricular conduction disorders. At 180 dpi, 30 days after treatment interruption, the GW3x-treated group remained in a better cardiac functional condition. Further, GW788388 treatment reversed the loss of connexin-43 enriched intercellular plaques and reduced fibrosis of the cardiac tissue. Inhibition of the TGF-ß signaling pathway reduced TGF-ß/pSmad2/3, increased MMP-9 and Sca-1, reduced TIMP-1/TIMP-2/TIMP-4, and partially restored GATA-6 and Tbox-5 transcription, supporting cardiac recovery. Moreover, GW788388 administration did not modify cardiac parasite load during the infection but reduced the migration of CD3+ cells to the heart tissue. Altogether, our data suggested that the single dose schedule was not as effective as the others and treatment three times per week during 30 days seems to be the most effective strategy. The therapeutic effects of GW788388 are promising and suggest a new possibility to treat cardiac fibrosis in the chronic phase of Chagas' heart disease by TGF-ß inhibitors.


Assuntos
Benzamidas/uso terapêutico , Cardiomiopatia Chagásica/tratamento farmacológico , Coração/efeitos dos fármacos , Pirazóis/uso terapêutico , Fator de Crescimento Transformador beta/antagonistas & inibidores , Tripanossomicidas/uso terapêutico , Animais , Cardiomiopatia Chagásica/parasitologia , Cardiomiopatia Chagásica/patologia , Doença Crônica , Conexina 43/metabolismo , Modelos Animais de Doenças , Feminino , Fibrose/tratamento farmacológico , Coração/parasitologia , Sistema de Condução Cardíaco/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Carga Parasitária , Trypanosoma cruzi/efeitos dos fármacos
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