Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 48
Filtrar
1.
Vaccines (Basel) ; 11(7)2023 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-37514999

RESUMEN

Immune responses after COVID-19 vaccination should be evaluated in different populations around the world. This study compared antibody responses induced by ChAdOx1 nCoV-19, CoronaVac, and BNT162b2 vaccines. Blood samples from vaccinees were collected pre- and post-vaccinations with the second and third doses. The study enrolled 78 vaccinees, of whom 62.8% were women, with the following median ages: 26 years-ChAdOx1 nCoV-19; 40 years-CoronaVac; 30 years-BNT162b2. Serum samples were quantified for anti-RBD IgG and anti-RBD IgA and anti-spike IgG by ELISA. After two vaccine doses, BNT162b2 vaccinees produced higher levels of anti-RBD IgA and IgG, and anti-spike IgG compared to ChAdOx1 nCoV-19 and CoronaVac vaccinees. The third dose booster with BNT162b2 induced higher levels of anti-RBD IgA and IgG, and anti-spike IgG in CoronaVac vaccinees. Individuals who reported a SARS-CoV-2 infection before or during the study had higher anti-RBD IgA and IgG production. In conclusion, two doses of the studied vaccines induced detectable levels of anti-RBD IgA and IgG and anti-spike IgG in vaccinees. The heterologous booster with BNT162b2 increased anti-RBD IgA and IgG and anti-spike IgG levels in CoronaVac vaccinees and anti-RBD IgA levels in ChAdOx1 nCoV-19 vaccinees. Furthermore, SARS-CoV-2 infection induced higher anti-RBD IgA and IgG levels in CoronaVac vaccinees.

2.
Biochim Biophys Acta Biomembr ; 1864(9): 183977, 2022 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-35654148

RESUMEN

Spin label electron paramagnetic resonance (EPR) spectroscopy was used to study the mechanisms of action of ivermectin and curcumin against Leishmania (L.) amazonensis promastigotes. EPR spectra showed that treatment of the parasites with both compounds results in plasma membrane rigidity due to oxidative processes. With the IC50 and EPR measurements for assays using different parasite concentrations, estimations could be made for the membrane-water partition coefficient (KM/W), and the concentration of the compound in the membrane (cm50) and in the aqueous phase (cw50), which inhibits cell growth by 50%. The KM/W values indicated that ivermectin has a greater affinity than curcumin for the parasite membrane. Therefore, the activity of ivermectin was higher for experiments with low cell concentrations, but for concentrations greater than 1.5 × 108 parasites/mL the compounds did not show significantly different results. The cm50 values indicated that the concentration of compound in the membrane leading to growth inhibition or membrane alteration is approximately 1 M for both ivermectin and curcumin. This high membrane concentration suggests that many ivermectin molecules per chlorine channel are needed to cause an increase in chlorine ion influx.


Asunto(s)
Antiprotozoarios , Curcumina , Leishmania mexicana , Leishmania , Antiprotozoarios/química , Antiprotozoarios/farmacología , Membrana Celular/metabolismo , Curcumina/metabolismo , Curcumina/farmacología , Ivermectina/análisis , Ivermectina/metabolismo , Ivermectina/farmacología , Estrés Oxidativo
3.
Clin Lung Cancer ; 23(6): e377-e383, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35660356

RESUMEN

BACKGROUND: EGFRm represent 15% of advanced NSCLC in European patients. LB for molecular profiling offers a non-invasive alternative to tissue. cdPCR is a high-sensitive and low-cost LB to detect molecular alterations. We aimed to describe cdPCR clinical utility for EGFRm detection in advanced NSCLC. METHODS: Prospective blood sample collection in patients with advanced NSCLC harbouring EGFRm either at diagnosis, under response or at PD between January 16 and September 20 at Gustave Roussy. LB was performed by cdPCR (Stilla): sensitizing (exon19; exon21 [p.L858R]) and exon 20 p.T790M resistance EGFRm. We defined high tumour burden (high-TB) as >2 metastatic sites. We analysed EGFRm detection by cdPCR and its correlation with progression-free and overall survival (PFS, OS). RESULTS: A total of 252 blood samples were collected in 140 patients. At baseline (n=25), sensitizing EGFRm were detected in 64% of samples, 88% in patients with high-TB (n=8) and 40% among those with intracranial/intrathoracic isolated lesions (n=5). At PD to tyrosine-kinase inhibitors (TKI) (n=117), detection rate (sensitizing EGFRm) was 56%; 30% in patients with intracranial/thoracic isolated lesions (n=37) vs. 67% in those with high-TB (n=63). At PD to first/second generation TKI (n=81), the p.T790M mutation was found in 22% (18/81); detection rate was 9% for intracranial/thoracic (n=23) vs. 32% for high-TB (n=41) cases. The clearance of EGFRm allelic frequency was correlated with radiological response. The absence of EGFRm detection at TKI-failure was associated with longer OS (39.1 vs. 18.4 months; P=.02). CONCLUSIONS: cdPCR is a sensitive LB for sensitizing and resistance EGFRm detection. cdPCR positivity was more likely observed in systemic PD cases with high-TB. It is a low-cost EGFRm detecting approach to guide treatment in NSCLC, however metastatic profile should be taken into account.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/genética , Receptores ErbB/genética , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Mutación/genética , Reacción en Cadena de la Polimerasa , Estudios Prospectivos , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/uso terapéutico
4.
Toxicol In Vitro ; 79: 105294, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-34896601

RESUMEN

4-hydroxy-2-nonenal (HNE) is a reactive aldehyde produced by cells under conditions of oxidative stress, which has been shown to react with proteins and phosphatidylethanolamine in biological membranes. Using electron paramagnetic resonance (EPR) spectroscopy of a spin label it was demonstrated that 2 h of treatment with HNE causes membrane rigidity in promastigotes of Leishmania (L.) amazonensis, J774.A1 macrophages and erythrocytes. Remarkable fluidity-reducing effects on the parasite membrane were observed at HNE concentrations approximately 4-fold lower than in the case of erythrocyte and macrophage membranes. Autofluorescence of the parasites in PBS suspension (1 × 107 cell/mL) with excitation at 354 nm showed a linear increase of intensity in the range of 400 to 600 nm over 3 h after treatment with 30 µM HNE. Parasite ghosts prepared after this period of HNE treatment showed a high degree of membrane rigidity. Bovine serum albumin (BSA) in PBS treated with HNE for 2 h showed an increase in molecular dynamics and suffered a decrease in its ability to bind a lipid probe. In addition, the antiproliferative activity of L. amazonensis promastigotes, macrophage cytotoxicity and hemolytic potential were assessed for HNE. An IC50 of 24 µM was found, which was a concentration > 10 times lower than the cytotoxic and hemolytic concentrations of HNE. These results indicate that the action of HNE has high selectivity indices for the parasite as opposed to the macrophage and erythrocyte.


Asunto(s)
Aldehídos/farmacología , Eritrocitos/efectos de los fármacos , Leishmania/efectos de los fármacos , Macrófagos/efectos de los fármacos , Aldehídos/toxicidad , Animales , Línea Celular , Membrana Celular/efectos de los fármacos , Espectroscopía de Resonancia por Spin del Electrón , Humanos , Fluidez de la Membrana/efectos de los fármacos , Ratones , Albúmina Sérica Bovina/efectos de los fármacos
5.
Lung Cancer ; 166: 255-264, 2022 04.
Artículo en Inglés | MEDLINE | ID: mdl-34953624

RESUMEN

INTRODUCTION: A phase I open-label multicentre study was initiated to evaluate the association of tremelimumab with gefitinib in EGFR-mutant NSCLC patients who progressed after first-generation EGFR-TKI. Here we provide the efficacy data from the entire cohort. MATERIAL AND METHODS: Patients with advanced EGFR-mutant NSCLC with progression after response to EGFR-TKI were enrolled. Study treatment was gefitinib 250 mg daily and tremelimumab at 3 dose levels: 3, 6 and 10 mg/kg IV Q4W for 6 cycles followed by Q12W until progression or unacceptable toxicity. The primary objective was safety and tolerability, and to establish a RP2D. RESULTS: Between January 2014 and July 2015, 27 patients (21 in the escalating dose cohort and 6 in expansion cohort) received at least one dose of tremelimumab. DLTs occurred in 4 patients: 1 at 3 mg/kg (one grade 3 diarrhoea), 1 at 6 mg/kg (one grade 3 diarrhoea) and 2 at 10 mg/kg (one grade 3 diarrhoea and one grade 3 AST/ALT increase) of tremelimumab. Grade 3 TRAE occurred in 22 patients (81%), most frequently diarrhoea (30%) and ALT/AST increase (15%). Stable disease was the best overall response in 72% patients, with median PFS of 2.2 months (95% CI, 1.8-4.2). All patients discontinued treatment, most frequently due to disease progression (63% of patients). CONCLUSION: The recommended dose of tremelimumab in combination with gefitinib in EGFR-mutant NSCLC patients was 3 mg/kg. The gastrointestinal toxicity and the limited efficacy data prevented further evaluation of this combination. (GEFTREM; clinical trial number NCT02040064).


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Anticuerpos Monoclonales Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/genética , Diarrea/inducido químicamente , Receptores ErbB/genética , Gefitinib/uso terapéutico , Humanos , Neoplasias Pulmonares/inducido químicamente , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Mutación
6.
Acta Trop ; 224: 106146, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34562423

RESUMEN

Coinfection with the human immunodeficiency virus (HIV) and Leishmania impairs immune responses, increases treatment failure and relapse rates in patients with American tegumentary leishmaniasis (ATL), as well as visceral leishmaniasis (VL). There is insufficient data on the treatment, relapse, and secondary prophylaxis in patients coinfected with HIV/Leishmania in Brazil. This study investigated patients with HIV/ATL and HIV/VL to describe the outcome of leishmaniasis in patients assisted at a referral hospital of Brazilian midwestern region. Patients with HIV/ATL (n = 21) mainly presented cutaneous diseases (76.2%) with an overall relapse rate of 28.57% after treatment, whereas HIV/VL (n = 28) patients accounted for 17.5% of the cases. The counts of CD4+ T cells and CD8+ T cells and the CD4+/CD8+ cell ratios at diagnosis or relapses were not significantly different between relapsing and non-relapsing patients. Patients with HIV/ATL or HIV/VL showed high levels of activation markers in CD4+ and CD8+ T cells. The regular use of highly active antiretroviral therapy (HAART) and viral load at the time of diagnosis did not influence the relapse rates. Relapses occurred in 36.4% (4/11) of the patients with HIV/VL receiving secondary prophylaxis and in 5.9% (1/17) of the patients who did not receive secondary prophylaxis (p = 0.06). These data are relevant for the therapeutic management of the patients coinfected with HIV/Leishmania.


Asunto(s)
Coinfección , Infecciones por VIH , Leishmania , Leishmaniasis Visceral , Leishmaniasis , Linfocitos T CD8-positivos , Infecciones por VIH/complicaciones , Infecciones por VIH/tratamiento farmacológico , Humanos , Recurrencia
7.
Cancers (Basel) ; 13(16)2021 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-34439359

RESUMEN

BACKGROUND: Approximately 15% of patients infected by SARS-CoV-2 develop a distress syndrome secondary to a host hyperinflammatory response induced by a cytokine storm. Myelosuppression is associated with a higher risk of infections and mortality. There are data to support methods of management for neutropenia and COVID-19. We present a multicenter experience during the first COVID-19 outbreak in neutropenic cancer patients infected by SARS-CoV-2. METHODS: Clinical retrospective data were collected from neutropenic cancer patients with COVID-19. Comorbidities, tumor type, stage, treatment, neutropenia severity, G-CSF, COVID-19 parameters, and mortality were analyzed. A bivariate analysis of the impact on mortality was carried out. Additionally, we performed a multivariable logistic regression to predict respiratory failure and death. RESULTS: Among the 943 cancer patients screened, 83 patients (11.3%) simultaneously had neutropenia and an infection with COVID-19. The lungs (26%) and breasts (22%) were the primary locations affected, and most patients had advanced disease (67%). In the logistic model, as adjusted covariates, sex, age, treatment (palliative vs. curative), tumor type, and the lowest level of neutrophils were used. A significant effect was obtained for the number of days of G-CSF treatment (OR = 1.4, 95% CI [1,1,03,92], p-value = 0.01). CONCLUSIONS: Our findings suggest that a prolonged G-CSF treatment could be disadvantageous for these cancer patients with infections by COVID-19, with a higher probability of worse outcome.

8.
Eur J Pharm Sci ; 163: 105859, 2021 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-33894283

RESUMEN

Electron paramagnetic resonance (EPR) spectroscopy of spin labels was used to study the interactions of amphotericin B (AmB) with the plasma membrane of Leishmania (L.) amazonensis promastigotes, human erythrocytes and J774.A1 murine macrophages, in comparison with reported and novel data for miltefosine (MIL). One of the objectives of this work is to look for the relationships between the activities of these two drugs in the Leishmania parasite with their changes in the cell membrane. A spin-labeled stearic acid inserted into the cell membranes showed strong interactions with putative AmB/sterol complexes, characterized by reductions in molecular dynamics. The concentration of the drugs in the plasma membrane that reduced the cell population by 50%, and the membrane-water partition coefficient of the drugs, were assessed. These biophysical parameters enabled estimates of possible therapeutic concentrations of these two drugs in the interstitial fluids of the tissues to be made. AmB displayed higher affinity for the plasma membrane of L. amazonensis than for that of the macrophage and erythrocyte, denoting a preference for a membrane that contains ergosterol. AmB also demonstrated higher hemolytic potential than MIL for measurements on erythrocytes in both PBS and whole blood. For MIL, the EPR technique detected membrane changes induced by the drug in the same concentration range that inhibited the growth of parasites, but in the case of AmB, an 8-fold higher concentration of the IC50 was necessary to observe a reduction in membrane fluidity, suggesting a better localized effect of AmB on the membrane. Taken together, the results demonstrate that the antiproliferative and cytotoxic effects of both drugs are associated with changes in cell membranes.


Asunto(s)
Antiprotozoarios , Leishmania , Anfotericina B/farmacología , Animales , Antiprotozoarios/farmacología , Espectroscopía de Resonancia por Spin del Electrón , Eritrocitos , Humanos , Macrófagos , Ratones , Fosforilcolina/análogos & derivados
9.
J Phys Chem B ; 124(45): 10157-10165, 2020 11 12.
Artículo en Inglés | MEDLINE | ID: mdl-33119317

RESUMEN

Electron paramagnetic resonance (EPR) spectroscopy of spin labels was used to study the interactions of amphotericin B (AmB) with the plasma membrane of Leishmania amazonensis promastigotes, erythrocytes, and J774 macrophages. Spin labels embedded into the cell membranes detected strong interactions with putative AmB/sterol complexes that resulted in pronounced changes in the EPR spectra, which can be interpreted as a reduction in membrane fluidity or an increase in the polarity assessed by the spin probe. The EPR spectra of spin-labeled lipids corroborated the findings that AmB does not enter phospholipid membrane-sterol models and probably forms extramembranous aggregates, as predicted by the sterol sponge model. Furthermore, these aggregates were shown to extract the spin probe androstanol from the lipid bilayer. However, in contrast to the results for the model membrane, EPR spectroscopy suggested that AmB easily enters the membranes of the studied cells, implying that the entry process is dependent on interactions with the membrane proteins.


Asunto(s)
Anfotericina B , Leishmania , Anfotericina B/farmacología , Membrana Celular , Espectroscopía de Resonancia por Spin del Electrón , Fluidez de la Membrana , Marcadores de Spin
10.
Eur J Pharm Sci ; 151: 105407, 2020 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-32504805

RESUMEN

A novel chalcone derivative, LQFM064, demonstrated antileishmanial activity against Leishmania (L.) amazonensis, with an IC50 value of ~10 µM for the promastigote form. Electron paramagnetic resonance (EPR) spectroscopy of a spin-labeled stearic acid incorporated in the plasma membrane of L. amazonensis promastigotes revealed that after 2 h of treatment with LQFM064, the parasite showed remarkable reductions in membrane fluidity. The features of the altered EPR spectra were similar to those reported for the erythrocyte membrane, which was suggested to be due to the cross-linking of oxidized hemoglobin with the cytoskeleton spectrin. In comparison to miltefosine (MIL), LQFM064 demonstrated a much lower hemolytic potential against both erythrocytes in PBS and whole blood, less cytotoxicity in J774.A1 macrophages and equivalent ability to kill parasites internalized in J774.A1 macrophages. Measurements of the IC50 values for assays with different cell concentrations enabled the estimation of the membrane-water partition coefficient (KM/W), as well as the concentrations of LQFM064 in membrane (cm50) and aqueous phase (cw50) that reduces the cell population by 50%. From the KM/W and cm50 values it was deduced that LQFM064 has a greater affinity than MIL for the parasite membrane, but the antiproliferative activity of both substances is exerted at a similar concentration in the plasma membrane.


Asunto(s)
Antiprotozoarios , Chalcona , Chalconas , Parásitos , Animales , Antiprotozoarios/farmacología , Chalconas/farmacología , Espectroscopía de Resonancia por Spin del Electrón
11.
PLoS Negl Trop Dis ; 14(2): e0008029, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-32023240

RESUMEN

Interleukin-32 is a novel inflammatory mediator that has been described to be important in the immunopathogenesis and control of infections caused by Leishmania parasites. By performing experiments with primary human cells in vitro, we demonstrate that the expression of IL-32 isoforms is dependent on the time exposed to L. amazonensis and L. braziliensis antigens. Moreover, for the first time we show the functional consequences of three different genetic variations in the IL32 (rs4786370, rs4349147, rs1555001) modulating IL-32γ expression, influencing innate and adaptive cytokine production after Leishmania exposure. Using a Brazilian cohort of 107 American Tegumentary Leishmaniasis patients and a control cohort of 245 healthy individuals, the IL32 rs4786370 genetic variant was associated with protection against ATL, whereas the IL32 rs4349147 was associated with susceptibility to the development of localized cutaneous and mucosal leishmaniasis. These novel insights may help improve therapeutic strategies and lead to benefits for patients suffering from Leishmania infections.


Asunto(s)
Predisposición Genética a la Enfermedad , Variación Genética , Interleucinas/genética , Leishmania/clasificación , Leishmaniasis Cutánea/genética , Adulto , Anciano , Brasil/epidemiología , Citocinas/genética , Citocinas/metabolismo , Femenino , Regulación de la Expresión Génica/inmunología , Humanos , Lectinas Tipo C/genética , Lectinas Tipo C/metabolismo , Leishmaniasis Cutánea/epidemiología , Leishmaniasis Cutánea/inmunología , Leishmaniasis Cutánea/metabolismo , Masculino , Persona de Mediana Edad , Proteína Adaptadora de Señalización NOD2/genética , Proteína Adaptadora de Señalización NOD2/metabolismo , Isoformas de Proteínas , Receptor Toll-Like 4/genética , Receptor Toll-Like 4/metabolismo
12.
Colloids Surf B Biointerfaces ; 183: 110421, 2019 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-31401463

RESUMEN

Using the electron paramagnetic resonance (EPR) of spin-labeled stearic acid and a spin label chemically attached to the membrane proteins, the interaction of miltefosine (MIL) and the ionic surfactants sodium dodecyl sulfate (SDS, anionic), cetyltrimethylammonium chloride (CTAC, cationic) and N-hexadecyl-N,N-dimethyl-3-ammonio-1-propanesulfonate (HPS, zwitterionic) with the plasma membrane of Leishmania (L.) amazonensis promastigotes was studied. The spin-label EPR data indicated that the four compounds studied have the ability to increase the molecular dynamics of membrane proteins to a large extent. Compared to the other compounds, SDS produced the smallest increases in dynamics and demonstrated the lowest antileishmanial activity and cytotoxicity to J774.A1 macrophages. The activities of the other three compounds were not different from each other, but CTAC had a stronger activity against L. amazonensis promastigotes at higher cellular concentrations (> 1 × 109 cells/mL) and was the most effective against L. amazonensis-infected macrophages. However, CTAC was also the most cytotoxic to macrophages. By measuring the IC50/CC50 values for assays of different cell concentrations, we estimated the membrane-water partition coefficient (KM/W) as well as the concentrations in the membrane (cm50) and aqueous phase (cw50) of the compounds at their IC50/CC50. Compared to the other compounds, SDS showed the lowest value of KM/W and the highest value of cm50. In all experiments in this study, the data for the zwitterionic molecules HPS and MIL were not significantly different.


Asunto(s)
Antiprotozoarios/farmacología , Cetrimonio/farmacología , Citotoxinas/farmacología , Leishmania braziliensis/efectos de los fármacos , Compuestos de Amonio Cuaternario/farmacología , Dodecil Sulfato de Sodio/farmacología , Tensoactivos/farmacología , Antiprotozoarios/química , Línea Celular , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Permeabilidad de la Membrana Celular/efectos de los fármacos , Cetrimonio/química , Citotoxinas/química , Espectroscopía de Resonancia por Spin del Electrón , Humanos , Concentración 50 Inhibidora , Leishmania braziliensis/crecimiento & desarrollo , Leishmania braziliensis/metabolismo , Macrófagos/efectos de los fármacos , Macrófagos/parasitología , Simulación de Dinámica Molecular , Fosforilcolina/análogos & derivados , Fosforilcolina/farmacología , Compuestos de Amonio Cuaternario/química , Dodecil Sulfato de Sodio/química , Marcadores de Spin , Ácidos Esteáricos/química , Tensoactivos/química
13.
Parasite Immunol ; 41(5): e12623, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30870579

RESUMEN

Phenotypic and functional aspects of monocytes from Localized Cutaneous Leishmaniasis (LCL) patients were evaluated. The frequencies of monocyte subsets and TLR2/TLR4 expression were evaluated in fresh peripheral blood whereas cytokine production was evaluated in whole blood cell cultures stimulated with TLR agonists or Leishmania braziliensis antigen (Ag). CD16+ monocytes frequency was increased in patients compared with controls. A TLR4 agonist (LPS) induced expression of TNF and IL-10 in monocyte subsets of patients and controls. The CD14+ CD16+ monocytes expressed higher levels of these cytokines than CD14+ CD16- cells. The levels of secreted TNF were higher in whole blood cell cultures from patients than controls after LPS/TLR4 or Ag stimulation. Whereas in controls there was a positive correlation between TNF and IL-10 levels, this was not observed in stimulated cell cultures from patients. The high levels of LPS-induced TNF were associated with the number of lesions and the percentages of CD14hi CD16+ monocytes. The levels of TLR2-induced TNF were also associated with number of lesions. All monocyte subsets from patients expressed higher levels of TLR2 and TLR4 than controls. Data suggest that systemically activated monocytes contribute for an imbalance in pro- and anti-inflammatory cytokine production during LCL, participating in the immunopathogenesis of the disease.


Asunto(s)
Leishmaniasis Cutánea/inmunología , Adulto , Anciano , Citocinas/inmunología , Femenino , Humanos , Interleucina-10/inmunología , Leishmaniasis Cutánea/parasitología , Masculino , Persona de Mediana Edad , Monocitos/inmunología , Adulto Joven
14.
Biochim Biophys Acta Biomembr ; 1861(6): 1049-1056, 2019 06 01.
Artículo en Inglés | MEDLINE | ID: mdl-30890467

RESUMEN

The sesquiterpene nerolidol is a membrane-active compound that has demonstrated antitumor, antibacterial, antifungal and antiparasitic activities. In this study, we used electron paramagnetic resonance (EPR) spectroscopy and biophysical parameters determined via cell culture assays to study the mechanisms underlying the in vitro antileishmanial activity of nerolidol. The EPR spectra of a spin-labeled stearic acid indicated notable interactions of nerolidol with the cell membrane of Leishmania amazonensis amastigotes. The nerolidol IC50 values in L. amazonensis amastigotes and promastigotes were found to depend on the cell concentration used in the assay. This dependence was described by an equation that considers various cell suspension parameters, such as the 50% inhibitory concentrations of nerolidol in the cell membrane (cm50) and the aqueous phase (cw50) and the membrane-water partition coefficient of nerolidol (KM/W). Via cytotoxicity (CC50) and hemolytic potential (HC50) data, these parameters were also determined for nerolidol in macrophages and erythrocytes. With a cw50 of 125 µM, macrophages were less sensitive to nerolidol than amastigotes and promastigotes, which had mean cw50 values of 56 and 74 µM, respectively. The estimated cm50 values of nerolidol for amastigotes and promastigotes and macrophages were between 2.6 and 3.0 M, indicating substantial accumulation of nerolidol in the cell membrane. In addition, the spin-label EPR data indicated that membrane dynamic changes occurred in L. amazonensis amastigotes at concentrations similar to the nerolidol IC50 value.


Asunto(s)
Antineoplásicos/farmacología , Antiprotozoarios/farmacología , Leishmania/efectos de los fármacos , Fluidez de la Membrana/efectos de los fármacos , Sesquiterpenos/farmacología , Animales , Membrana Celular/efectos de los fármacos , Membrana Celular/metabolismo , Espectroscopía de Resonancia por Spin del Electrón , Hemólisis/efectos de los fármacos , Ratones , Ratones Endogámicos BALB C
15.
Free Radic Biol Med ; 129: 35-45, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30196081

RESUMEN

Human leishmaniasis caused by Leishmania (Viannia) braziliensis can be presented as localized cutaneous leishmaniasis (LCL) or mucosal leishmaniasis (ML). Macrophages kill parasites using nitric oxide (NO) and reactive oxygen species (ROS). The aim of this study was to evaluate the ability of parasites obtained from patients with LCL or ML to produce and resist NO or ROS. Promastigotes and amastigotes from LCL or ML isolates produced similar amounts of NO in culture. Promastigotes from ML isolates were more resistant to NO and H2O2 than LCL parasites in a stationary phase, whereas amastigotes from LCL isolates were more resistant to NO. In addition, in the stationary phase, promastigote isolates from patients with ML expressed more thiol-specific antioxidant protein (TSA) than LCL isolates. Therefore it is suggested that infective promastigotes from ML isolates are more resistant to microbicidal mechanisms in the initial phase of infection. Subsequently, amastigotes lose this resistance. This behavior of ML parasites can decrease the number of parasites capable of stimulating the host immune response shortly after the infection establishment.


Asunto(s)
Antiprotozoarios/farmacología , Peróxido de Hidrógeno/farmacología , Leishmania braziliensis/efectos de los fármacos , Estadios del Ciclo de Vida/efectos de los fármacos , Óxido Nítrico/farmacología , Animales , Antioxidantes/química , Antioxidantes/metabolismo , Medios de Cultivo/química , Femenino , Interacciones Huésped-Parásitos , Humanos , Inmunidad Innata , Leishmania braziliensis/crecimiento & desarrollo , Leishmania braziliensis/aislamiento & purificación , Leishmania braziliensis/metabolismo , Leishmaniasis Cutánea Difusa/inmunología , Leishmaniasis Cutánea Difusa/metabolismo , Leishmaniasis Cutánea Difusa/parasitología , Leishmaniasis Mucocutánea/inmunología , Leishmaniasis Mucocutánea/metabolismo , Leishmaniasis Mucocutánea/parasitología , Estadios del Ciclo de Vida/fisiología , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Óxido Nítrico/metabolismo , Donantes de Óxido Nítrico/farmacología , Nitroprusiato/farmacología , Proteínas Protozoarias/genética , Proteínas Protozoarias/metabolismo
16.
Am J Trop Med Hyg ; 99(5): 1165-1169, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30203744

RESUMEN

The disseminated form of leishmaniasis is a serious and rare disease, being diagnosed in 2% of the cutaneous cases registered per year in Brazil. The main characteristic is the appearance of multiple pleomorphic lesions on the cutaneous surface. A 68-year-old male from the rural area of Tocantins, Brazil, presented atypical disseminated cutaneous leishmaniasis (ACL). The clinical course and histopathological and immunological findings presented a mixed pattern that hindered diagnosis and therapeutic management. Molecular typing revealed a mixed infection with Leishmania (V.) guyanensis and Leishmania (L.) amazonensis. Molecular identification of the agents responsible for ACL is important for adequate therapeutic planning, minimizing the possibility of sequellae that impact the quality of life of the patient.


Asunto(s)
Coinfección/diagnóstico , Coinfección/parasitología , Leishmania guyanensis/genética , Leishmania mexicana/genética , Leishmaniasis Cutánea/diagnóstico , Anciano , Anfotericina B/uso terapéutico , Antiprotozoarios/uso terapéutico , Brasil , ADN Protozoario/genética , Técnica del Anticuerpo Fluorescente Indirecta , Humanos , Leishmania guyanensis/aislamiento & purificación , Leishmania mexicana/aislamiento & purificación , Leishmaniasis Cutánea/tratamiento farmacológico , Leishmaniasis Cutánea/parasitología , Masculino , Tipificación Molecular , Población Rural , Piel/parasitología , Piel/patología
17.
Infect Immun ; 86(5)2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29483288

RESUMEN

Visceral leishmaniasis (VL) is a chronic parasitic disease caused by Leishmania infantum in the Americas. During VL, several proinflammatory cytokines are produced in spleen, liver, and bone marrow. However, the role of interleukin-32 (IL-32) has not been explored in this disease. IL-32 can induce production of proinflammatory cytokines in innate immune cells and polarize the adaptive immune response. Herein, we discovered that L. infantum antigens induced expression of mRNA mainly for the IL-32γ isoform but also induced low levels of the IL-32ß transcript in human peripheral blood mononuclear cells. Furthermore, infection of human IL-32γ transgenic mice (IL-32γTg mice) with L. infantum promastigote forms increased IL-32γ expression in the spleen and liver. Interestingly, IL-32γTg mice harbored less parasitism in the spleen and liver than wild-type (WT) mice. In addition, IL-32γTg mice showed increased granuloma formation in the liver compared to WT mice. The protection against VL was associated with increased production of nitric oxide (NO), interferon gamma (IFN-γ), IL-17A, and tumor necrosis factor alpha by splenic cells restimulated ex vivo with L. infantum antigens. In parallel, there was an increase in the number of Th1 and Th17 T cells in the spleens of IL-32γTg mice infected with L. infantum IL-32γ induction of IFN-γ and IL-17A expression was found to be essential for NO production by splenic cells of infected animals. These data indicate that IL-32γ potentiates the Th1/Th17 immune response during experimental VL, thus contributing to the control of L. infantum infection.


Asunto(s)
Inmunidad Innata/inmunología , Inmunidad Innata/fisiología , Interleucinas/inmunología , Interleucinas/fisiología , Leishmania infantum/inmunología , Leishmaniasis Visceral/inmunología , Factores Protectores , Animales , Humanos , Ratones , Ratones Endogámicos BALB C , Ratones Transgénicos , Modelos Animales
18.
Parasitol Res ; 117(2): 419-427, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29270768

RESUMEN

Because of visceral leishmaniasis (VL) urbanization and spreading of the human immunodeficiency virus (HIV) infection to rural areas, coinfection has become more common. Here, we compared the accuracy of Kalazar Detect® (KD), an rK39-based immunochromatographic (IC) test, and OrangeLife® (OL), an rK39 + rK28 IC test, for diagnosing VL in patients coinfected with HIV in an endemic area in Brazil. Seventy-six VL patients and 40 patients with other diseases, of which 31 and 21 patients, respectively, were infected with HIV, were examined. The sensitivity of OL and KD tests was 88.89 and 95.45%, respectively, in patients without HIV. The sensitivity dropped to 67.74 and 61.29%, respectively, in coinfected patients. The decrease in sensitivity was not related to a decrease in the production of Leishmania-specific IgG. Because of the low sensitivity of rk39 test in HIV-infected patients, we suggest that patients with negative rK39 results should undergo further investigation with additional serological tests that are not based only on the rK39 antigen and examination of bone marrow aspirates.


Asunto(s)
Cromatografía de Afinidad/métodos , Infecciones por VIH/complicaciones , Leishmaniasis Visceral/diagnóstico , Adulto , Antígenos de Protozoos/inmunología , Brasil , Coinfección , Femenino , Humanos , Leishmaniasis Visceral/complicaciones , Masculino , Proteínas Protozoarias/inmunología , Sensibilidad y Especificidad
19.
Immunol Invest ; 47(1): 71-88, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29077524

RESUMEN

Parkinson's disease (PD) is an age-related neurodegenerative disease characterized by loss of dopaminergic neurons associated with neuroinflammation. Toll-like receptors (TLRs) are expressed in peripheral blood leukocytes and also in neurons and glial cells mediating inflammation. This study aimed to investigate the peripheral blood leukocyte response to TLR2 and TLR4 agonists in young and elderly PD patients. Two groups of patients with PD were evaluated (≤ 55 years old and ≥ 65 years old), age-matched with healthy controls (n = 26). Severity of PD was evaluated by Unified Parkinson's Disease Rating Scale (UPDRS). Whole blood cultures were stimulated with lipopolysaccharide (LPS), a TLR4 agonist or Pam3Cys (Pam), a TLR2 agonist. Tumor necrosis factor alpha (TNFα) and interleukin 10 (IL-10) were measured by immunoenzimatic assay. 6 h-TNFα production was increased after TLR4 stimulation, mainly in young PD patients, whereas TLR2-induced TNFα and IL-10 levels were decreased in PD patients independent of age (p < 0.05). A reverse correlation between LPS-induced TNFα production and age was observed in PD patients and controls, but TNFα induced by TLR2 agonist was not associated with age of PD patients or controls. TNFα production induced by TLR4 but not by TLR2 was reversely associated with the age at PD onset and disease duration. No associations between UPDRS scores and cytokine levels were detected. In conclusion, TLR4 and TLR2 responses seem to be differentially affected during PD. Data suggest that TLR2 deficiency in periphery is independent of age of the patients, age at PD onset, or PD duration.


Asunto(s)
Factores de Edad , Envejecimiento/inmunología , Enfermedad de Parkinson/inmunología , Receptor Toll-Like 2/metabolismo , Receptor Toll-Like 4/metabolismo , Adulto , Anciano , Células Cultivadas , Humanos , Interleucina-10/metabolismo , Lipopolisacáridos/inmunología , Lipoproteínas/inmunología , Persona de Mediana Edad , Riesgo , Receptor Toll-Like 2/agonistas , Receptor Toll-Like 4/agonistas , Factor de Necrosis Tumoral alfa/metabolismo
20.
Rev Inst Med Trop Sao Paulo ; 59: e91, 2017 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-29267599

RESUMEN

Determination of the epidemiological profile of the American tegumentary leishmaniasis (ATL) and identification of Leishmania species that are prevalent in the State of Tocantins were carried out through a retrospective and descriptive study based on data reported in SINAN, in the period from 2011 to 2015. Molecular techniques such as PCR-RFLP and PCR-G6PD to amplify Leishmania DNA were performed on stored on Giemsa-stained slides from lesion scarifications of ATL patients who were amastigote-positive by the direct microscopic examination. There were 1,434 ATL cases in Tocantins reported in this period. The highest incidence was reported in men aged over 60 years, rural residents, the most affected ethnic group was mixed ethnicity (mixed black and white) and the ones with lower education. The predominant clinical form was cutaneous, being diagnosed mainly by laboratory methods. Pentavalent antimonial was effective in resolving cases. The predominant species found in 271 analyzed samples from 32 municipalities located in 8 different health regions of Tocantins was Leishmania (Viannia) braziliensis. Identifying the epidemiological profile and characterizing the Leishmania spp species on regional level is essential to establish control and prevention behaviors, minimizing the number of cases and treatment resistance, recurrence and evolution to mucosal forms.


Asunto(s)
Leishmania braziliensis/aislamiento & purificación , Leishmaniasis Cutánea/epidemiología , Leishmaniasis Cutánea/parasitología , Adolescente , Adulto , Distribución por Edad , Brasil/epidemiología , Niño , Preescolar , ADN Protozoario , Femenino , Humanos , Lactante , Leishmania braziliensis/genética , Masculino , Persona de Mediana Edad , Reacción en Cadena de la Polimerasa , Polimorfismo de Longitud del Fragmento de Restricción , Prevalencia , Estudios Retrospectivos , Distribución por Sexo , Factores Socioeconómicos , Factores de Tiempo , Adulto Joven
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...