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1.
J Infect Dis ; 2024 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-38804698

RESUMO

Accurate detection of viable Leishmania parasites is critical for evaluating visceral leishmaniasis (VL) treatment response at an early timepoint. We compared the decay of kinetoplast DNA (kDNA) and spliced-leader RNA (SL-RNA) in vitro, in vivo, and in a VL patient cohort. An optimized combination of blood preservation and nucleic acid extraction improved efficiency for both targets. SL-RNA degraded more rapidly during treatment than kDNA, and correlated better with microscopic examination. SL-RNA quantitative polymerase chain reaction emerges as a superior method for dynamic monitoring of viable Leishmania parasites. It enables individualized treatment monitoring for improved prognoses and has potential as an early surrogate endpoint in clinical trials.

2.
J Antimicrob Chemother ; 79(7): 1547-1554, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38727613

RESUMO

INTRODUCTION: Post-kala-azar dermal leishmaniasis (PKDL) arises as a dermal complication following a visceral leishmaniasis (VL) infection. Current treatment options for PKDL are unsatisfactory, and there is a knowledge gap regarding the distribution of antileishmanial compounds within human skin. The present study investigated the skin distribution of miltefosine in PKDL patients, with the aim to improve the understanding of the pharmacokinetics at the skin target site in PKDL. METHODS: Fifty-two PKDL patients underwent treatment with liposomal amphotericin B (20 mg/kg) plus miltefosine (allometric dosing) for 21 days. Plasma concentrations of miltefosine were measured on study days 8, 15, 22 and 30, while a punch skin biopsy was taken on day 22. A physiologically based pharmacokinetic (PBPK) model was developed to evaluate the distribution of miltefosine into the skin. RESULTS: Following the allometric weight-based dosing regimen, median miltefosine concentrations on day 22 were 43.73 µg/g (IQR: 21.94-60.65 µg/g) in skin and 33.29 µg/mL (IQR: 25.9-42.58 µg/mL) in plasma. The median individual concentration ratio of skin to plasma was 1.19 (IQR: 0.79-1.9). In 87% (45/52) of patients, skin exposure was above the suggested EC90 PK target of 10.6 mg/L associated with in vitro susceptibility. Simulations indicated that the residence time of miltefosine in the skin would be more than 2-fold longer than in plasma, estimated by a mean residence time of 604 versus 266 hours, respectively. CONCLUSION: This study provides the first accurate measurements of miltefosine penetration into the skin, demonstrating substantial exposure and prolonged retention of miltefosine within the skin. These findings support the use of miltefosine in cutaneous manifestations of leishmaniasis. In combination with parasitological and clinical data, these results are critical for the future optimization of combination therapies with miltefosine in the treatment of PKDL.


Assuntos
Anfotericina B , Antiprotozoários , Leishmaniose Cutânea , Leishmaniose Visceral , Fosforilcolina , Pele , Humanos , Fosforilcolina/análogos & derivados , Fosforilcolina/farmacocinética , Fosforilcolina/administração & dosagem , Fosforilcolina/uso terapêutico , Antiprotozoários/farmacocinética , Antiprotozoários/administração & dosagem , Antiprotozoários/uso terapêutico , Masculino , Adulto , Leishmaniose Cutânea/tratamento farmacológico , Leishmaniose Cutânea/parasitologia , Feminino , Pele/parasitologia , Leishmaniose Visceral/tratamento farmacológico , Pessoa de Meia-Idade , Adulto Jovem , Anfotericina B/farmacocinética , Anfotericina B/uso terapêutico , Anfotericina B/administração & dosagem , Adolescente , Ásia Meridional
3.
Clin Infect Dis ; 76(3): e1177-e1185, 2023 02 08.
Artigo em Inglês | MEDLINE | ID: mdl-36164254

RESUMO

BACKGROUND: This study aimed to determine whether paromomycin plus miltefosine (PM/MF) is noninferior to sodium stibogluconate plus paromomycin (SSG/PM) for treatment of primary visceral leishmaniasis in eastern Africa. METHODS: An open-label, phase 3, randomized, controlled trial was conducted in adult and pediatric patients at 7 sites in eastern Africa. Patients were randomly assigned to either 20 mg/kg paromomycin plus allometric dose of miltefosine (14 days), or 20 mg/kg sodium stibogluconate plus 15 mg/kg paromomycin (17 days). The primary endpoint was definitive cure after 6 months. RESULTS: Of 439 randomized patients, 424 completed the trial. Definitive cure at 6 months was 91.2% (155 of 170) and 91.8% (156 of 170) in the PM/MF and SSG/PM arms in primary efficacy modified intention-to-treat analysis (difference, 0.6%; 97.5% confidence interval [CI], -6.2 to 7.4), narrowly missing the noninferiority margin of 7%. In the per-protocol analysis, efficacy was 92% (149 of 162) and 91.7% (155 of 169) in the PM/MF and SSG/PM arms (difference, -0.3%; 97.5% CI, -7.0 to 6.5), demonstrating noninferiority. Treatments were well tolerated. Four of 18 serious adverse events were study drug-related, and 1 death was SSG-related. Allometric dosing ensured similar MF exposure in children (<12 years) and adults. CONCLUSIONS: PM/MF and SSG/PM efficacies were similar, and adverse drug reactions were as expected given the drugs safety profiles. With 1 less injection each day, reduced treatment duration, and no risk of SSG-associated life-threatening cardiotoxicity, PM/MF is a more patient-friendly alternative for children and adults with primary visceral leishmaniasis in eastern Africa. CLINICAL TRIALS REGISTRATION: NCT03129646.


Assuntos
Antiprotozoários , Leishmaniose Visceral , Adulto , Humanos , Criança , Paromomicina/efeitos adversos , Antiprotozoários/efeitos adversos , Gluconato de Antimônio e Sódio/efeitos adversos , Leishmaniose Visceral/tratamento farmacológico , Resultado do Tratamento , Quimioterapia Combinada , África Oriental , Fosforilcolina/efeitos adversos
4.
J Antimicrob Chemother ; 78(11): 2702-2714, 2023 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-37726401

RESUMO

OBJECTIVES: To improve visceral leishmaniasis (VL) treatment in Eastern Africa, 14- and 28-day combination regimens of paromomycin plus allometrically dosed miltefosine were evaluated. As the majority of patients affected by VL are children, adequate paediatric exposure to miltefosine and paromomycin is key to ensuring good treatment response. METHODS: Pharmacokinetic data were collected in a multicentre randomized controlled trial in VL patients from Kenya, Sudan, Ethiopia and Uganda. Patients received paromomycin (20 mg/kg/day for 14 days) plus miltefosine (allometric dose for 14 or 28 days). Population pharmacokinetic models were developed. Adequacy of exposure and target attainment of paromomycin and miltefosine were evaluated in children and adults. RESULTS: Data from 265 patients (59% ≤12 years) were available for this pharmacokinetic analysis. Paromomycin exposure was lower in paediatric patients compared with adults [median (IQR) end-of-treatment AUC0-24h 187 (162-203) and 242 (217-328) µg·h/mL, respectively], but were both within the IQR of end-of-treatment exposure in Kenyan and Sudanese adult patients from a previous study. Cumulative miltefosine end-of-treatment exposure in paediatric patients and adults [AUCD0-28 517 (464-552) and 524 (456-567) µg·day/mL, respectively] and target attainment [time above the in vitro susceptibility value EC90 27 (25-28) and 30 (28-32) days, respectively] were comparable to previously observed values in adults. CONCLUSIONS: Paromomycin and miltefosine exposure in this new combination regimen corresponded to the desirable levels of exposure, supporting the implementation of the shortened 14 day combination regimen. Moreover, the lack of a clear exposure-response and exposure-toxicity relationship indicated adequate exposure within the therapeutic range in the studied population, including paediatric patients.


Assuntos
Antiprotozoários , Leishmaniose Visceral , Humanos , Adulto , Criança , Paromomicina/uso terapêutico , Leishmaniose Visceral/tratamento farmacológico , Antiprotozoários/farmacocinética , Quênia , Fosforilcolina/uso terapêutico , Fosforilcolina/farmacocinética , Uganda , Resultado do Tratamento
5.
Clin Infect Dis ; 75(8): 1423-1432, 2022 10 12.
Artigo em Inglês | MEDLINE | ID: mdl-35147680

RESUMO

BACKGROUND: Visceral leishmaniasis (VL) in patients with human immunodeficiency virus (HIV) presents an increasingly important patient cohort in areas where both infections are endemic. Evidence for treatment is sparce, with no high-quality studies from the Indian subcontinent. METHODS: This is a randomized, open-label, parallel-arm, phase 3 trial conducted within a single hospital in Patna, India. One hundred and fifty patients aged ≥18 years with serologically confirmed HIV and parasitologically confirmed VL were randomly allocated to 1 of 2 treatment arms, either a total 40 mg/kg intravenous liposomal amphotericin B (AmBisome; Gilead Pharmaceuticals) administered in 8 equal doses over 24 days or a total 30 mg/kg intravenous AmBisome administered in 6 equal doses given concomitantly with a total 1.4 g oral miltefosine administered through 2 daily doses of 50 mg over 14 days. The primary outcome was intention-to-treat relapse-free survival at day 210, defined as absence of signs and symptoms of VL or, if symptomatic, negative parasitological investigations. RESULTS: Among 243 patients assessed for eligibility, 150 were recruited between 2 January 2017 and 5 April 2018, with no loss to follow-up. Relapse-free survival at day 210 was 85% (64/75; 95% CI, 77-100%) in the monotherapy arm, and 96%, (72/75; 90-100%) in the combination arm. Nineteen percent (28/150) were infected with concurrent tuberculosis, divided equally between arms. Excluding those with concurrent tuberculosis, relapse-free survival at day 210 was 90% (55/61; 82-100%) in the monotherapy and 97% (59/61; 91-100%) in the combination therapy arm. Serious adverse events were uncommon and similar in each arm. CONCLUSIONS: Combination therapy appears to be safe, well tolerated, and effective, and halves treatment duration of current recommendations. CLINICAL TRIALS REGISTRATION: Clinical Trial Registry India (CTRI/2015/05/005807; the protocol is available online at https://osf.io/avz7r).


Assuntos
Antiprotozoários , Coinfecção , Infecções por HIV , Leishmaniose Visceral , Adolescente , Adulto , Anfotericina B , Antiprotozoários/efeitos adversos , Coinfecção/tratamento farmacológico , Quimioterapia Combinada , HIV , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Humanos , Índia , Leishmaniose Visceral/complicações , Leishmaniose Visceral/tratamento farmacológico , Preparações Farmacêuticas , Fosforilcolina/efeitos adversos , Fosforilcolina/análogos & derivados , Recidiva , Resultado do Tratamento
6.
Clin Infect Dis ; 73(5): 775-782, 2021 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-33580234

RESUMO

BACKGROUND: To expedite the development of new oral treatment regimens for visceral leishmaniasis (VL), there is a need for early markers to evaluate treatment response and predict long-term outcomes. METHODS: Data from 3 clinical trials were combined in this study, in which Eastern African VL patients received various antileishmanial therapies. Leishmania kinetoplast DNA was quantified in whole blood with real-time quantitative polymerase chain reaction (qPCR) before, during, and up to 6 months after treatment. The predictive performance of pharmacodynamic parameters for clinical relapse was evaluated using receiver-operating characteristic curves. Clinical trial simulations were performed to determine the power associated with the use of blood parasite load as a surrogate endpoint to predict clinical outcome at 6 months. RESULTS: The absolute parasite density on day 56 after start of treatment was found to be a highly sensitive predictor of relapse within 6 months of follow-up at a cutoff of 20 parasites/mL (area under the curve 0.92, specificity 0.91, sensitivity 0.89). Blood parasite loads correlated well with tissue parasite loads (ρ = 0.80) and with microscopy gradings of bone marrow and spleen aspirate smears. Clinical trial simulations indicated a > 80% power to detect a difference in cure rate between treatment regimens if this difference was high (> 50%) and when minimally 30 patients were included per regimen. CONCLUSIONS: Blood Leishmania parasite load determined by qPCR is a promising early biomarker to predict relapse in VL patients. Once optimized, it might be useful in dose finding studies of new chemical entities.


Assuntos
Leishmaniose Visceral , Parasitos , África Oriental , Animais , Biomarcadores , Humanos , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/tratamento farmacológico , Carga Parasitária
7.
J Antimicrob Chemother ; 76(5): 1258-1268, 2021 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-33677546

RESUMO

BACKGROUND: Despite high HIV co-infection prevalence in Ethiopian visceral leishmaniasis (VL) patients, the adequacy of antileishmanial drug exposure in this population and effect of HIV-VL co-morbidity on pharmacokinetics of antileishmanial and antiretroviral (ARV) drugs is still unknown. METHODS: HIV-VL co-infected patients received the recommended liposomal amphotericin B (LAmB) monotherapy (total dose 40 mg/kg over 24 days) or combination therapy of LAmB (total dose 30 mg/kg over 11 days) plus 28 days 100 mg/day miltefosine, with possibility to extend treatment for another cycle. Miltefosine, total amphotericin B and ARV concentrations were determined in dried blood spots or plasma using LC-MS/MS. RESULTS: Median (IQR) amphotericin B Cmax on Day 1 was 24.6 µg/mL (17.0-34.9 µg/mL), which increased to 40.9 (25.4-53.1) and 33.2 (29.0-46.6) µg/mL on the last day of combination and monotherapy, respectively. Day 28 miltefosine concentration was 18.7 (15.4-22.5) µg/mL. Miltefosine exposure correlated with amphotericin B accumulation. ARV concentrations were generally stable during antileishmanial treatment, although efavirenz Cmin was below the 1 µg/mL therapeutic target for many patients. CONCLUSIONS: This study demonstrates that antileishmanial drug exposure was low in this cohort of HIV co-infected VL patients. Amphotericin B Cmax was 2-fold lower than previously observed in non-VL patients. Miltefosine exposure in HIV-VL co-infected patients was 35% lower compared with adult VL patients in Eastern Africa, only partially explained by a 19% lower dose, possibly warranting a dose adjustment. Adequate drug exposure in these HIV-VL co-infected patients is especially important given the high proportion of relapses.


Assuntos
Antiprotozoários , Infecções por HIV , Leishmaniose Visceral , Preparações Farmacêuticas , Adulto , África Oriental , Antiprotozoários/uso terapêutico , Cromatografia Líquida , Estudos de Coortes , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Humanos , Leishmaniose Visceral/complicações , Leishmaniose Visceral/tratamento farmacológico , Leishmaniose Visceral/epidemiologia , Fosforilcolina/uso terapêutico , Espectrometria de Massas em Tandem , Resultado do Tratamento
8.
Int J Biometeorol ; 65(10): 1695-1705, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33830324

RESUMO

The aim of this study was to estimate, using data mining, which microclimate and behavioral variables affect the behavior of animals to seek shaded or sunny areas. The experiment was carried out between January and May 2016 in an integrated crop-livestock-forest system. In this system, we defined two different areas: shaded and sunny. Microclimatic variables (At, BGt, RH, and WS) were measured in each area on 4 consecutive days per month. With these variables, we determined the bioclimatic indicators (THI, BGHI, HLI, MRT, RTL, and ETI). In addition, we calculated the absolute difference (Δ) by subtracting the value recorded in shaded areas from the value recorded in sunny areas for all microclimatic variables and bioclimatic indicators, except for WS. The behaviors (grazing, ruminating, and other activities), posture (standing or lying), and use of areas (shaded or sunny) of 38 Zebu cattle were recorded on 2 consecutive days per month. The data mining technique was applied for analysis in a classification task. The model correctly classified 76% of the instances with a Kappa statistic of 0.51 after features selection from the database. The ΔBGt was the most important feature in the model to classify the decision of Zebu cattle to seek another area or remain in a determined area. The model was built with seven classification rules, being one simple rule, composed of the interaction between ΔBGt and rumination; and other more complex rules, composed of the interactions among the ΔBGt, WS, and rumination. The preference of Zebu cattle to seek or remain in shaded or sunny areas was influenced by eight features: rumination, drinking water, WS, ΔBGt, MRT in shade, BGHI in sun, ΔBGHI, and HLI in sun.


Assuntos
Microclima , Luz Solar , Animais , Bovinos , Florestas
9.
J Therm Biol ; 97: 102871, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33863435

RESUMO

With the expanding use of thermal assessment techniques in beef cattle, infrared thermography has become a promising tool for assessing the environment for animal thermal comfort. Goals of this study were: (1) to evaluate cattle thermal comfort in agroforestry systems with different shade availability (2) to verify the spatiotemporal variations of infrared temperature inside agroforestry systems, and; (3) to test infrared thermography as a potential tool to assess animal thermal comfort indices in agroforestry systems. A trial was carried out between June 2015 and February 2016, covering Central-Brazil's dry winter and rainy summer seasons, respectively. The experimental area of Embrapa Beef Cattle is located in Campo Grande (Mato Grosso do Sul), coordinates 20°24'53″ S, 54°42'26″ W and 558 m altitude. The 12 ha plot has two agroforestry systems varying shade availability. Traditional Black Globe Temperature and Humidity Index, Heat Load Index and Radiation Thermal Load were determined, from measurements using digital thermo-hygrometers, with datalogger. Surface temperature and humidity of tree canopies and pasture were determined using an infrared thermographic camera. Results show spatiotemporal variations in infrared temperature. This means that the environment inside agroforestry systems is not homogeneously comfortable for cattle, and the system with the lowest shade availability has the greatest heat accumulation area. Weak to strong associations were identified between infrared variables and thermal comfort indices (0.08 = r ≤ 0.75). Positive relationships were also obtained and equally well explained by the Black Globe Temperature and Humidity Index and Heat Load Index (0.55 = R2 ≤ 0.94). We conclude that infrared thermography can be used as a tool to assess thermal comfort indices in agroforestry systems and to determine onset of animal thermal stress from environment and heat body accumulation.


Assuntos
Criação de Animais Domésticos/métodos , Bovinos/fisiologia , Termografia/métodos , Sensação Térmica , Árvores , Animais , Brasil , Florestas , Resposta ao Choque Térmico , Umidade , Raios Infravermelhos , Microclima , Temperatura
10.
J Antimicrob Chemother ; 75(11): 3260-3268, 2020 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-32780098

RESUMO

BACKGROUND: Conventional miltefosine dosing (2.5 mg/kg/day) for treatment of visceral leishmaniasis (VL) is less effective in children than in adults. A higher allometric dose (median 3.2 mg/kg/day) was therefore investigated in paediatric VL patients in Eastern Africa. Results of this trial showed an unforeseen, lower than dose-proportional increase in exposure. Therefore, we performed a pooled model-based analysis of the paediatric data available from both dosing regimens to characterize observed non-linearities in miltefosine pharmacokinetics (PK). METHODS: Fifty-one children with VL were included in this analysis, treated with either a conventional (n = 21) or allometric (n = 30) miltefosine dosing regimen. PK data were analysed using non-linear mixed-effects modelling. RESULTS: A two-compartment model following first-order absorption and linear elimination, with two separate effects on relative oral bioavailability, was found to fit these data best. A 69% lower bioavailability at treatment start was estimated, presumably due to initial malnourishment and malabsorption. Stagnation in miltefosine accumulation in plasma, hampering increased drug exposure, was related to the increase in cumulative dose (mg/kg/day). However, the allometric regimen increased exposure 1.7-fold in the first treatment week and reduced the time to reach the PK target by 17.4%. CONCLUSIONS: Miltefosine PK in children suffering from VL are characterized by dose-dependent non-linearities that obstruct the initially expected exposure levels. Bioavailability appeared to be affected by the cumulative dose, possibly as a consequence of impaired absorption. Despite this, allometric dosing led to a faster target achievement and increased exposure compared with conventional dosing.


Assuntos
Antiprotozoários , Leishmaniose Visceral , Adulto , África Oriental , Antiprotozoários/uso terapêutico , Criança , Humanos , Leishmaniose Visceral/tratamento farmacológico , Fosforilcolina/análogos & derivados , Fosforilcolina/uso terapêutico
11.
Int J Biometeorol ; 64(5): 881-888, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32152728

RESUMO

The objective of this study was to assess the use of infrared thermography as a microclimate-evaluating tool and an estimate of the thermal comfort provided by four types of tree to cattle under grazing conditions in the central region of Brazil. The experiment was conducted at the Embrapa Beef Cattle Company, in Campo Grande, MS, Brazil, from June to August 2015. Evaluations were carried out over four consecutive days, at 1-hour intervals, from 8:00 a.m. to 4:00 p.m. (local time; GMT - 4:00). Infrared thermography images of tree crowns and soil surface underneath them from the shadow projection of four tree species native to the Brazilian cerrado (savannah-like) biome were obtained. The microclimate was assessed by estimation of thermal indices: temperature and humidity index, black globe, and radiation thermal load. The previous was calculated based on records of air temperature, dew point temperature, black globe temperature, air relative humidity, wind speed, and solar radiation. The geometrical settings of the trees were assessed for each tree component. Five thematic groups were formed based on multiple factor analysis that summarizes three synthetic analytical dimensions to explain the total variance among the studied elements and the existing correlations between groups. Positive linear correlations were found between thermography and the temperature measurements, thermal comfort indices, and radiation, suggesting that infrared thermography can be used as a tool for estimating and monitoring the microclimate and thermal comfort, presenting a potential use of measurement in agroforestry systems.


Assuntos
Gado , Termografia , Animais , Brasil , Bovinos , Umidade , Microclima , Temperatura
12.
Clin Microbiol Rev ; 31(4)2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30158301

RESUMO

Research in visceral leishmaniasis in the last decade has been focused on how better to use the existing medicines as monotherapy or in combination. Systematic research by geographical regions has shown that a universal treatment is far from today's reality. Substantial progress has been made in the elimination of kala-azar in South Asia, with a clear strategy on first- and second-line therapy options of single-dose liposomal amphotericin B and a combination of paromomycin and miltefosine, respectively, among other interventions. In Eastern Africa, sodium stibogluconate (SSG) and paromomycin in combination offer an advantage compared to the previous SSG monotherapy, although not exempted of limitations, as this therapy requires 17 days of painful double injections and bears the risk of SSG-related cardiotoxicity. In this region, attempts to improve the combination therapy have been unsuccessful. However, pharmacokinetic studies have led to a better understanding of underlying mechanisms, like the underexposure of children to miltefosine treatment, and an improved regimen using an allometric dosage. Given this global scenario of progress and pitfalls, we here review what steps need to be taken with existing medicines and highlight the urgent need for oral drugs. Furthermore, it should be noted that six candidates belonging to five new chemical classes are reaching phase I, ensuring an optimistic near future.


Assuntos
Antiprotozoários/uso terapêutico , Descoberta de Drogas/tendências , Leishmaniose Visceral/tratamento farmacológico , Pesquisa Biomédica/tendências , Humanos
13.
Trop Anim Health Prod ; 52(5): 2273-2281, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32144659

RESUMO

The aim of this study was to evaluate the impact of increased shadow supply in integrated crop-livestock-forest systems on in vitro embryonic development and physiological parameters related to stress response in Nellore heifers (Bos indicus). For the study, animals (n = 16) were randomly divided into two groups and kept in areas with different afforestation systems, the integrated crop-livestock-forest (ICLF) and the integrated crop-livestock (ICL) system. The microclimate of the ICLF system provided better comfort conditions than ICL. No differences of respiratory rate, rectal temperature, cortisol, T3, T4, oocyte quality, and cleavage rate between the systems were verified. A higher blastocyst rate was observed in the ICLF (p < 0.05). The results demonstrate that Nellore heifers managed in ICLF during summer in Midwest of Brazil showed higher production of in vitro embryos, without typical changes in its physiological parameters. The results observed in the present study indicate that zebu females are able to respond satisfactorily to the intense heat conditions; however, we believe that the long period to which these animals are exposed to these conditions interferes in the oocyte competence and embryo development.


Assuntos
Bovinos/fisiologia , Embrião de Mamíferos/fisiologia , Fertilização in vitro/veterinária , Microclima , Animais , Desenvolvimento Embrionário , Feminino , Temperatura Alta
14.
Clin Infect Dis ; 68(9): 1530-1538, 2019 04 24.
Artigo em Inglês | MEDLINE | ID: mdl-30188978

RESUMO

BACKGROUND: Convenient, safe, and effective treatments for visceral leishmaniasis in Eastern African children are lacking. Miltefosine, the only oral treatment, failed to achieve adequate efficacy, particularly in children, in whom linear dosing (2.5 mg/kg/day for 28 days) resulted in a 59% cure rate, with lower systemic exposure than in adults. METHODS: We conducted a Phase II trial in 30 children with visceral leishmaniasis, aged 4-12 years, to test whether 28 days of allometric miltefosine dosing safely achieves a higher systemic exposure than linear dosing. RESULTS: Miltefosine accumulated during treatment. Median areas under the concentration time curve from days 0-210 and plasma maximum concentration values were slightly higher than those reported previously for children on linear dosing, but not dose-proportionally. Miltefosine exposure at the start of treatment was increased, with higher median plasma concentrations on day 7 (5.88 versus 2.67 µg/mL). Concentration-time curves were less variable, avoiding the low levels of exposure observed with linear dosing. The 210-day cure rate was 90% (95% confidence interval, 73-98%), similar to that previously described in adults. There were 19 treatment-related adverse events (AEs), but none caused treatment discontinuation. There were 2 serious AEs: both were unrelated to treatment and both patients were fully recovered. CONCLUSIONS: Allometric miltefosine dosing achieved increased and less-variable exposure than linear dosing, though not reaching the expected exposure levels. The new dosing regimen safely increased the efficacy of miltefosine for Eastern African children with visceral leishmaniasis. Further development of miltefosine should adopt allometric dosing in pediatric patients. CLINICAL TRIALS REGISTRATION: NCT02431143.


Assuntos
Antiprotozoários/farmacocinética , Leishmaniose Visceral/tratamento farmacológico , Fosforilcolina/análogos & derivados , África Oriental , Antiprotozoários/sangue , Antiprotozoários/farmacologia , Área Sob a Curva , Criança , Pré-Escolar , Esquema de Medicação , Feminino , Humanos , Leishmania donovani/efeitos dos fármacos , Leishmania donovani/crescimento & desenvolvimento , Leishmania donovani/patogenicidade , Leishmaniose Visceral/sangue , Leishmaniose Visceral/parasitologia , Leishmaniose Visceral/patologia , Masculino , Segurança do Paciente , Fosforilcolina/sangue , Fosforilcolina/farmacocinética , Fosforilcolina/farmacologia , Resultado do Tratamento
15.
Artigo em Inglês | MEDLINE | ID: mdl-30509941

RESUMO

This work evaluated a serial blood sampling procedure to enhance the sensitivity of duplex real-time quantitative PCR (qPCR) for baseline detection and quantification of parasitic loads and posttreatment identification of failure in the context of clinical trials for treatment of chronic Chagas disease, namely, DNDi-CH-E1224-001 (ClinicalTrials.gov registration no. NCT01489228) and the MSF-DNDi PCR Sampling Optimization Study (NCT01678599). Patients from Cochabamba (n = 294), Tarija (n = 257), and Aiquile (n = 220) were enrolled. Three serial blood samples were collected at each time point, and qPCR triplicates were tested for each sample. The first two samples were collected during the same day and the third one 7 days later. A patient was considered PCR positive if at least one qPCR replicate was detectable. Cumulative results of multiple samples and qPCR replicates enhanced the proportion of pretreatment sample positivity from 54.8% to 76.2%, 59.5% to 77.8%, and 73.5% to 90.2% in Cochabamba, Tarija, and Aiquile cohorts, respectively. This strategy increased the detection of treatment failure from 72.9% to 91.7%, 77.8% to 88.9%, and 42.9% to 69.1% for E1224 low-, short-, and high-dosage regimens, respectively, and from 4.6% to 15.9% and 9.5% to 32.1% for the benznidazole arm in the DNDi-CH-E1224-001 and MSF-DNDi studies, respectively. The addition of the third blood sample and third qPCR replicate in patients with nondetectable PCR results in the first two samples gave a small, non-statistically significant improvement in qPCR positivity. No change in clinical sensitivity was seen with a blood volume increase from 5 to 10 ml. The monitoring of patients treated with placebo in the DNDi-CH-E1224-001 trial revealed fluctuations in parasitic loads and occasionally nondetectable results. In conclusion, a serial sampling strategy enhanced PCR sensitivity to detecting treatment failure during follow-up and has the potential for improving recruitment capacity in Chagas disease trials, which require an initial positive qPCR result for patient admission.


Assuntos
Doença de Chagas/tratamento farmacológico , DNA de Protozoário/sangue , Monitorização Fisiológica/métodos , Carga Parasitária/métodos , Reação em Cadeia da Polimerase em Tempo Real/métodos , Adolescente , Adulto , Humanos , Pessoa de Meia-Idade , Nitroimidazóis/uso terapêutico , Placebos/administração & dosagem , Tiazóis/uso terapêutico , Resultado do Tratamento , Triazóis/uso terapêutico , Tripanossomicidas/uso terapêutico , Trypanosoma cruzi/efeitos dos fármacos , Adulto Jovem
16.
J Clin Microbiol ; 57(5)2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30787142

RESUMO

Visceral leishmaniasis (VL) is a serious and fatal disease caused by the parasites Leishmania infantum and Leishmania donovani The gold standard diagnostic test for VL is the demonstration of parasites or their DNA in spleen, lymph node, or bone marrow aspirates. Serological tests exist but cannot distinguish active VL from either prior exposure to the parasites or previously treated VL disease. Using mass spectroscopy, we have previously identified three L. infantum protein biomarkers (Li-isd1, Li-txn1, and Li-ntf2) in the urine of VL patients and developed a sensitive and specific urine-based antigen detection assay for the diagnosis of VL that occurs in Brazil (where VL is caused by L. infantum). However, unpublished observations from our laboratory at DetectoGen showed that these biomarkers were detected in only 55% to 60% of VL patients from India and Kenya, where the disease is caused by L. donovani Here, we report the discovery and characterization of two new biomarkers of L. donovani (Ld-mao1 and Ld-ppi1) present in the urine of VL patients from these two countries. Capture enzyme-linked immunosorbent assays using specific rabbit IgG and chicken IgY were developed, and the assays had sensitivities of 44.4% and 28.8% for the detection of Ld-mao1 and Ld-ppi1, respectively. In contrast, a multiplexed assay designed to simultaneously detect all five leishmanial biomarkers markedly increased the assay sensitivity to 82.2%. These results validate the utility of leishmanial protein biomarkers found in the urine of VL patients as powerful tools for the development of an accurate diagnostic test for this disease.


Assuntos
Ensaios de Triagem em Larga Escala/métodos , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/urina , Proteínas de Protozoários/urina , Adolescente , Adulto , Idoso , Anticorpos Antiprotozoários , Biomarcadores/urina , Brasil , Criança , Pré-Escolar , Ensaio de Imunoadsorção Enzimática/métodos , Feminino , Humanos , Índia , Quênia , Leishmania donovani/isolamento & purificação , Leishmania infantum/isolamento & purificação , Leishmaniose Visceral/parasitologia , Masculino , Espectrometria de Massas , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Adulto Jovem
17.
Am J Physiol Cell Physiol ; 314(6): C702-C711, 2018 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-29443552

RESUMO

The renin-angiotensin system (RAS) plays a pivotal role in the pathogenesis of cardiovascular diseases. New members of this system have been characterized and shown to have biologically relevant actions. Alamandine and its receptor MrgD are recently identified components of RAS. In the cardiovascular system, alamandine actions included vasodilation, antihypertensive, and antifibrosis effects. Currently, the actions of alamandine on cardiomyocytes are unknown. Here our goal was twofold: 1) to unravel the signaling molecules activated by the alamandine/MrgD axis in cardiomyocytes; and 2) to evaluate the ability of this axis to prevent angiotensin II (ANG II)-induced hypertrophy. In cardiomyocytes from C57BL/6 mice, alamandine treatment induced an increase in nitric oxide (NO) production, which was blocked by d-Pro7-ANG-(1-7), a MrgD antagonist. This NO rise correlated with increased phosphorylation of AMPK. Alamandine-induced NO production was preserved in Mas-/- myocytes and lost in MrgD-/- cells. Binding of fluorescent-labeled alamandine was observed in wild-type cells, but it was dramatically reduced in MrgD-/- myocytes. We also assessed the consequences of prolonged alamandine exposure to cultured neonatal rat cardiomyocytes (NRCMs) treated with ANG II. Treatment of NRCMs with alamandine prevented ANG II-induced hypertrophy. Moreover, the antihypertrophic actions of alamandine were mediated via MrgD and NO, since they could be prevented by d-Pro7-ANG-(1-7) or inhibitors of NO synthase or AMPK. ß-Alanine, a MrgD agonist, recapitulated alamandine's cardioprotective effects in cardiomyocytes. Our data show that alamandine via MrgD induces AMPK/NO signaling to counterregulate ANG II-induced hypertrophy. These findings highlight the therapeutic potential of the alamandine/MrgD axis in the heart.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Angiotensina II/toxicidade , Cardiomegalia/prevenção & controle , Miócitos Cardíacos/efeitos dos fármacos , Proteínas do Tecido Nervoso/agonistas , Óxido Nítrico/metabolismo , Oligopeptídeos/farmacologia , Receptores Acoplados a Proteínas G/agonistas , Animais , Cardiomegalia/induzido quimicamente , Cardiomegalia/enzimologia , Cardiomegalia/patologia , Células Cultivadas , Ativação Enzimática , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Miócitos Cardíacos/enzimologia , Miócitos Cardíacos/patologia , Proteínas do Tecido Nervoso/metabolismo , Oligopeptídeos/metabolismo , Fosforilação , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas/agonistas , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Ratos Wistar , Receptores Acoplados a Proteínas G/genética , Receptores Acoplados a Proteínas G/metabolismo , Transdução de Sinais/efeitos dos fármacos
18.
Clin Infect Dis ; 66(3): 444-451, 2018 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-29020217

RESUMO

Background: We have conducted a single-arm trial evaluating monthly pentamidine secondary prophylaxis (PSP) to prevent visceral leishmaniasis (VL) relapse in Ethiopian human immunodeficiency virus-infected patients. Outcomes at 12 months of PSP have been previously reported, supporting PSP effectiveness and safety. However, remaining relapse-free after PSP discontinuation is vital. We now report outcomes and associated factors for a period of up to 2.5 years after initiating PSP, including 1-year follow-up after PSP discontinuation. Methods: The trial had 3 phases: (1) 12 months of PSP; (2) a 6-month PSP extension period if CD4 count was ≤200 cells/µL at month 12; and (3) 12-month follow-up after stopping PSP. The probability of relapse and risk factors were calculated using Kaplan-Meier methods and Cox regression analysis. Results: For the 74 patients included, final study outcomes were as follows: 39 (53%) relapse-free, 20 (27%) relapsed, 5 (7%) deaths, 10 (14%) lost to follow-up. The 2-year risk of relapse was 36.9% (95% confidence interval, 23.4%-55.0%) and was highest for those with a history of VL relapse and low baseline CD4 count. Forty-five patients were relapse-free and in follow-up at month 12 of PSP. This included 28 patients with month 12 CD4 counts >200 cells/µL, remaining relapse-free after PSP discontinuation. Among the 17 with month 12 CD4 count <200 cells/µL, 1 relapsed and 3 were lost during the PSP extension period. During 1-year post-PSP follow-up, 2 patients relapsed and 1 was lost to follow-up. No PSP-related serious adverse events were reported during the PSP-extension/post-PSP follow-up period. Conclusions: It seems safe to discontinue PSP at month 12 CD4 counts of >200 cells/µL. The management of those failing to reach this level remains to be defined. Clinical Trials Registration: NCT01360762.


Assuntos
Antiprotozoários/uso terapêutico , Coinfecção/tratamento farmacológico , Infecções por HIV/complicações , Leishmaniose Visceral/tratamento farmacológico , Pentamidina/uso terapêutico , Adulto , Coinfecção/parasitologia , Coinfecção/virologia , Etiópia , Feminino , Infecções por HIV/parasitologia , Humanos , Leishmaniose Visceral/virologia , Masculino , Recidiva , Fatores de Risco , Prevenção Secundária , Fatores de Tempo , Resultado do Tratamento
19.
Artigo em Inglês | MEDLINE | ID: mdl-30275095

RESUMO

Chagas disease (CD) is recognized as one of the major neglected global tropical diseases. Benznidazole (BNZ) is the drug of choice for the treatment of adults, young infants, and newborns with CD. However, the pharmacokinetics (PK) of BNZ have been poorly evaluated in all age groups, with consequent gaps in knowledge about PK-pharmacodynamic relationships in CD. The purpose of this study was to develop and validate a bioanalytical method to quantify BNZ levels in small-volume whole-blood samples collected as dried blood spots (DBS). The analysis was performed using high-performance liquid chromatography-positive electrospray tandem mass spectrometry. PK evaluation in healthy male volunteers was conducted to verify the correlation between DBS and plasma BNZ concentrations. The calibration curve was linear from 50 to 20,000 ng · ml-1 Intra- and interday precision and bias values were less than 14.87% (n = 9) and 9.81% (n = 27), respectively. The recovery rates ranged from 94 to 100% with no matrix effect. There was no hematocrit level effect in a range of 20 to 70%. The PK results obtained from DBS and plasma were comparable (r2 = 0.8295) and equivalent to previously published information on BNZ. BNZ in DBS was stable at room temperature for more than one year. This article describes the first microsampling method for measuring BNZ levels in DBS that has the potential to facilitate broad implementation of PK in clinical trials involving adult and pediatric patients in remote areas and helps to address existing knowledge gaps in the treatment of CD.


Assuntos
Teste em Amostras de Sangue Seco/métodos , Nitroimidazóis/sangue , Espectrometria de Massas em Tandem/métodos , Adolescente , Adulto , Área Sob a Curva , Calibragem , Doença de Chagas/sangue , Doença de Chagas/tratamento farmacológico , Cromatografia Líquida/métodos , Estabilidade de Medicamentos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nitroimidazóis/farmacocinética , Sensibilidade e Especificidade
20.
Mem Inst Oswaldo Cruz ; 113(2): 130-134, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29236927

RESUMO

With this study, the authors hope to alert clinicians regarding the presence of human T-cell lymphotropic virus type 1 and 2 (HTLV-1/-2) infections in patients with viral hepatitis B and C in Brazil. HTLV-1/-2 were detected in 1.3% of hepatitis B virus (HBV)- and 5.3% of hepatitis C virus (HCV)-infected blood samples sent for laboratory viral load measurements. A partial association of human immunodeficiency virus (HIV)-1 and HTLV-1/-2 infection was detected in patients with HCV (HIV+, 27.3%), whereas this association was almost 100% in HBV-infected patients (HIV+, all except one). The high prevalence of HTLV-1/-2 infection among patients with hepatitis C was of concern, as HTLV-1/-2 could change the natural course of subsequent liver disease. The authors suggest including HTLV-1/-2 serology in the battery of tests used when following patients with viral hepatitis in Brazil, regardless of the HIV status.


Assuntos
Infecções por HTLV-I/diagnóstico , Infecções por HTLV-II/diagnóstico , Hepatite B/complicações , Hepatite C/complicações , Brasil/epidemiologia , Infecções por HTLV-I/complicações , Infecções por HTLV-I/epidemiologia , Infecções por HTLV-II/complicações , Infecções por HTLV-II/epidemiologia , Hepatite B/epidemiologia , Hepatite C/epidemiologia , Vírus Linfotrópico T Tipo 1 Humano/isolamento & purificação , Vírus Linfotrópico T Tipo 2 Humano/isolamento & purificação , Humanos , Notificação de Abuso
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