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1.
Artículo en Inglés | MEDLINE | ID: mdl-36193939

RESUMEN

Summary: The objective of our study was to evaluate the association between the previously described asthma risk factors and the prevalence of asthma in a population of Brazilian adults. A population-based cross-sectional study was conducted using data collected from 7891 patients. All patients in the database > 18 years of age were included. The following variables were collected from the health plan database: age, body mass index, smoking status, alcohol consumption, sedentary lifestyle, heart disease, hypertension, diabetes, and asthma diagnosis. The frequency of the collected variables was compared between patients with or without an asthma diagnosis, and logistic regression was performed. Of our total sample (7891 patients), 150 (1.9%) had asthma. The mean age of patients with asthma was 39.4 years. 1.4% of normal weight patients had the diagnosis of asthma, while 2.4% of overweight and 2.2% of obese patients had the diagnosis. Multivariate analysis demonstrated that a sedentary lifestyle and overweight and obesity were independently associated with asthma prevalence Odds Ratio (OR) (95% confidence interval): (1.61 (1.16-2.22) and 1.25 (1.03-1.52) respectively). Our data provide evidence that some clinical characteristics, such as sedentarism, overweight, and obesity, may be related to the prevalence of asthma in an adult population in southeastern Brazil. Such factors could be modified and better understood through multidisciplinary research and health programs that evaluate the risk factors for asthma in large populations.

2.
J Appl Microbiol ; 127(2): 576-585, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30786116

RESUMEN

AIMS: The objective of this research was to quantify the levels of circulating HspBP1 and anti-HspBP1 IgG in HIV-infected individuals and to correlate them with CD4 T cell counts and viral load, as well as to determine the kinetics of those proteins during acute phase. METHODS AND RESULTS: Sixty serum samples from HIV-positive outpatients, thirty with high viral load and thirty with low viral load were analysed. The HspBP1 and anti-HspBP1 were quantified by ELISA. To investigate the kinetic of HspBP1 and anti-HspBp1 during the acute phase, these proteins and antibodies were quantified in samples of a commercial seroconverting HIV panel. All dosages were compared with the CD4 and CD8 T cell counts and HIV viral load. The results indicated that HIV positive outpatients presented significant increase in HspBP1 and anti-HspBP1 serum levels, compared with uninfected healthy. HspBP1 and anti-HspBP1 were negatively correlated with CD4 counts and CD4:CD8 ratio. In the acute phase, HspBP1 became significantly elevated 15 days after HIV infection. CONCLUSIONS: These results indicate that the quantification of HspBP1 can be associated to others well-established parameters of the HIV progression. SIGNIFICANCE AND IMPACT OF THE STUDY: The discovery that HspBp1 and anti-HspBp1 are associated with progression of HIV infection is new and corroborates to validate the quantification of these proteins as an additional strategy in the management of the HIV infection.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales/sangre , Anticuerpos Antivirales/sangre , Infecciones por VIH/sangre , VIH/inmunología , Adulto , Recuento de Linfocito CD4 , Progresión de la Enfermedad , Femenino , VIH/aislamiento & purificación , Infecciones por VIH/inmunología , Infecciones por VIH/virología , Humanos , Masculino , Persona de Mediana Edad , Carga Viral
3.
Parasite Immunol ; 37(8): 385-93, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25983042

RESUMEN

Leishmaniasis is a vectorborne disease caused by Leishmania protozoa, which is a major health problem and a neglected disease common in many regions of the world. Leishmania is an intracellular parasite transmitted by sand flies that causes clinical manifestations ranging from a severe and potentially fatal disease named visceral leishmaniasis to less severe but in many cases disfiguring diseases that mainly affect the skin or mucosal tissues, known as cutaneous leishmaniasis. Despite the detection of Leishmania parasites in the brain and cerebrospinal fluid of human patients and dogs, epidemiological data, as well as information about the mechanisms of central and peripheral nervous system alterations, are poorly described. This review is focused on the current knowledge about the neurological manifestations and immunopathogenic mechanisms in human patients and animals infected with Leishmania.


Asunto(s)
Enfermedades de los Perros/fisiopatología , Leishmania/parasitología , Leishmaniasis/fisiopatología , Animales , Enfermedades de los Perros/inmunología , Perros , Humanos , Leishmaniasis/inmunología
4.
Actas Urol Esp (Engl Ed) ; 46(2): 78-84, 2022 Mar.
Artículo en Inglés, Español | MEDLINE | ID: mdl-35123885

RESUMEN

INTRODUCTION: Several studies have already shown that changes in the AR gene may be associated with a more aggressive disease phenotype and even castration-resistant prostate cancer. Thus, we investigated cytogenetic and molecular alterations linked to AR. MATERIALS AND METHODS: To evaluate AR methylation, we performed a cytogenetic-molecular analysis using fluorescence in situ hybridization that uses specific probes for the AR gene (Xq11.12) and the X chromosome centromere. For AR activity, we performed a qualitative analysis of human androgen receptor activity. To analyze the expression of AR in PC3 and LNCaP cell lines, we used qPCR assays. RESULTS: In the qPCR assay, we found downregulation of AR in the PC3 cell line compared with the LNCaP. We found the presence of X chromosome polysomy in PC-3 and LNCaP cell lines by FISH assay. In the HUMARA-Q assay, we found two X chromosomes/cell and the activity of both AR in the PC-3 cell line. In LNCaP cells, we found two X chromosomes/cell and methylation of only one AR. CONCLUSION: Castration-resistant prostate cancer phenotype represents a significant challenge in the setting of urological management. The X chromosomes and AR-linked alterations may contribute to a better understanding of the disease. However, further studies should be performed in an attempt to elucidate as much as possible the role of AR in the castration-resistant prostate cancer phenotype.


Asunto(s)
Neoplasias de la Próstata Resistentes a la Castración , Castración , Línea Celular Tumoral , Humanos , Hibridación Fluorescente in Situ , Masculino , Fenotipo , Neoplasias de la Próstata Resistentes a la Castración/genética
5.
Parasite Immunol ; 31(3): 140-6, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19222785

RESUMEN

Leishmaniasis causes high morbidity and mortality in tropical and subtropical areas. Mast cells can be activated by Leishmania or Leishmania products in vitro and in vivo. Several innate immunity mediators, including some released by mast cells, play roles in the outcome of the disease. In this study, we examined whether pharmacological inactivation of mast cells before infection with L. major interferes with the progressive disease in BALB/c mice. The results show that, when mast cells are degranulated before challenge with L. major, susceptible mice become more resistant to infection, as measured by decrease of lesion size and lower parasite loads. Mast cell degranulation reduced IL-4 production. Moreover, mast cells degranulation enhanced mRNA expression for IFN-gamma, inducible nitric oxide, CCL2 and CCL5 in response to infection. Mast cell degranulation also decreased parasite loads in IL-4 KO animals, indicating that mediators other than IL-4 are involved in susceptibility in vivo. Taken together, our results disclose a role for mast cells in the induction of susceptibility to infection. This work contributes to a better understanding of the role of mast cells in Leishmania infection, and suggests a new field of study for strategies to contain the parasite, restricting its dissemination.


Asunto(s)
Degranulación de la Célula , Leishmania major/inmunología , Leishmaniasis Cutánea/inmunología , Mastocitos/fisiología , Animales , Quimiocina CCL2/biosíntesis , Quimiocina CCL5/biosíntesis , Susceptibilidad a Enfermedades , Femenino , Pie/parasitología , Pie/patología , Perfilación de la Expresión Génica , Interferón gamma/biosíntesis , Interleucina-4/biosíntesis , Interleucina-4/deficiencia , Leishmaniasis Cutánea/patología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Óxido Nítrico/biosíntesis
6.
Parasite Immunol ; 30(3): 171-4, 2008 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18251971

RESUMEN

Glutathione (GSH) has an important dual role in parasite-host relationship in Leishmania major infection. Our previous studies showed that both antioxidant systems, glutathione and trypanothione/trypanothione reductase, participate in the protection of Leishmania against the toxic effect of nitrogen-derived reactive species. On the other hand, GSH also is very important to the modulation of the effective immune response, inducting NO production and leishmanicidal activity of macrophages. In the present study, we investigated the role of host GSH during the course of L. major infection, analysing the size of footpad lesions and parasite load from mice treated with two GSH modulators, N-acethyl-l-cysteine (NAC) and buthionine sulphoximine (BSO). Resistant mice treated with BSO, which depletes GSH develop exacerbated lesions, but only harbour higher parasite load in their lesions 2 weeks post-infection. Although the NAC treatment does not affect the footpad lesions development in susceptible BALB/c mice, it significantly reduced the tissue parasitism in the lesions throughout the course of infection. Interestingly, the treatment with BSO did not change the course of L. major infection on susceptible mice when compared with nontreated mice. These results suggest that GSH is an important antioxidant modulator during anti-Leishmania immune response in vivo.


Asunto(s)
Glutatión/antagonistas & inhibidores , Glutatión/inmunología , Leishmania major/inmunología , Leishmaniasis Cutánea/inmunología , Animales , Antimetabolitos/farmacología , Butionina Sulfoximina/farmacología , Pie/parasitología , Pie/patología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL
7.
Neurocirugía (Soc. Luso-Esp. Neurocir.) ; 33(4): 195-198, jul. - ago. 2022. ilus
Artículo en Inglés | IBECS (España) | ID: ibc-204454

RESUMEN

CSF hypotension arises in the context of a leak of CSF which causes negative intracranial pressure. Sacral fractures result from high-energy trauma which are frequently underdiagnosed. A ten-year-old boy presented with hip pain, after a fall. He mobilized both lower limbs, reported no leg pain, irradiation nor lack of sphincter control. The neurological examination was normal. When asked to stand, he began biparietal headache, nausea and vomiting, which improved laying down. CT scan showed an occult intrasacral meningocele; the MRI revealed collections of CSF along the spine, a S3 fracture with potential laceration of the meningocele and opening of a CSF fistula. Our diagnosis was the CSF hypotension, secondary to the fistula opening. The diagnosis was challenging. The child first presented with symptoms of CSF hypotension without evident cause. The discovery of the meningocele led us to hypothesize the opening of a fistula, a rare diagnosis, later confirmed by MRI (AU)


La hipotensión del LCR surge en el contexto de una fuga de dicho líquido que causa presión intracraneal negativa. Las fracturas del sacro son originadas por traumatismos de alta energía que a menudo no se diagnostican. Un niño de diez años acudió con dolor de cadera tras una caída. Podía mover las piernas, no reportando ningún dolor en las mismas, ni irradiación o falta de control del esfínter. El examen neurológico resultó normal. Cuando se le pidió que se pusiera de pie comenzó a sufrir cefalea biparietal, náuseas y vómitos, que mejoraban al tumbarse. La TC mostró un meningocele intrasacro oculto. La RM reveló rastros de LCR a lo largo de la columna, fractura en S3 con laceración potencial del meningocele y apertura de una fístula de LCR. Nuestro diagnóstico fue hipotensión de LCR, secundaria a la apertura de la fístula. El diagnóstico resultó difícil. El niño presentó síntomas de hipotensión del LCR sin causa evidente. El descubrimiento del meningocele nos llevó a conjeturar la apertura de una fístula, un diagnóstico infrecuente que fue confirmado posteriormente mediante RM (AU)


Asunto(s)
Humanos , Masculino , Niño , Meningocele/diagnóstico por imagen , Hipotensión Intracraneal/diagnóstico por imagen , Pérdida de Líquido Cefalorraquídeo/etiología , Fístula/complicaciones , Fístula/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Imagen por Resonancia Magnética
8.
Actas urol. esp ; 46(2): 78-84, mar. 2022. ilus, graf
Artículo en Español | IBECS (España) | ID: ibc-203557

RESUMEN

Introducción Diversos estudios han demostrado que los cambios en el gen RA pueden estar asociados a un fenotipo de enfermedad más agresivo e incluso al cáncer de próstata resistente a la castración. Por este motivo, hemos investigado las alteraciones citogénicas y moleculares asociadas al RA.Materiales y métodos Para evaluar la metilación del RA, realizamos un análisis citogenético-molecular mediante hibridación fluorescente in situ que utiliza sondas específicas para el gen del RA (Xq11.12) y el centrómero del cromosoma X. Respecto a la actividad del RA, realizamos un análisis cualitativo de la actividad del receptor de andrógenos humano. Para analizar la expresión del RA en las líneas celulares PC3 y LNCaP, utilizamos ensayos de qPCR.ResultadosEn el ensayo qPCR, encontramos una regulación a la baja del RA en la línea celular PC3 en comparación con la LNCaP. Hallamos la presencia de polisomía del cromosoma X en las líneas celulares PC-3 y LNCaP mediante el ensayo FISH. En el ensayo HUMARA-Q encontramos la presencia de dos cromosomas X/célula y actividad en ambos RA de la línea celular PC-3. En las células LNCaP hallamos la presencia de dos cromosomas X/célula y la metilación de solo un RA.Conclusión El fenotipo del cáncer de próstata resistente a la castración representa un gran desafio en el tratamiento urológico. Estos cromosomas X y las alteraciones ligadas al RA pueden contribuir a una mejor comprensión de la enfermedad; sin embargo, deben realizarse más estudios para arrojar más luz sobre el papel del RA en el fenotipo del cáncer de próstata resistente a la castración (AU)


Introduction Several studies have already shown that changes in the AR gene may be associated with a more aggressive disease phenotype and even castration-resistant prostate cancer. Thus, we investigated cytogenetic and molecular alterations linked to AR.Materials and methods To evaluate AR methylation, we performed a cytogenetic-molecular analysis using fluorescence in situ hybridization that uses specific probes for the AR gene (Xq11.12) and the X chromosome centromere. For AR activity, we performed a qualitative analysis of human androgen receptor activity. To analyze the expression of AR in PC3 and LNCaP cell lines, we used qPCR assays.ResultsIn the qPCR assay, we found downregulation of AR in the PC3 cell line compared with the LNCaP. We found the presence of X chromosome polysomy in PC-3 and LNCaP cell lines by FISH assay. In the HUMARA-Q assay, we found two X chromosomes/cell and the activity of both AR in the PC-3 cell line. In LNCaP cells, we found two X chromosomes/cell and methylation of only one AR.Conclusion Castration-resistant prostate cancer phenotype represents a significant challenge in the setting of urological management. The X chromosomes and AR-linked alterations may contribute to a better understanding of the disease. However, further studies should be performed in an attempt to elucidate as much as possible the role of AR in the castration-resistant prostate cancer phenotype (AU)


Asunto(s)
Humanos , Masculino , Neoplasias de la Próstata Resistentes a la Castración/genética , Línea Celular Tumoral , Hibridación Fluorescente in Situ , Fenotipo
9.
Braz J Med Biol Res ; 39(3): 355-63, 2006 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-16501815

RESUMEN

Glutathione is the major intracellular antioxidant thiol protecting mammalian cells against oxidative stress induced by oxygen- and nitrogen-derived reactive species. In trypanosomes and leishmanias, trypanothione plays a central role in parasite protection against mammalian host defence systems by recycling trypanothione disulphide by the enzyme trypanothione reductase. Although Kinetoplastida parasites lack glutathione reductase, they maintain significant levels of glutathione. The aim of this study was to use Leishmania donovani trypanothione reductase gene mutant clones and different Leishmania species to examine the role of these two individual thiol systems in the protection mechanism against S-nitroso-N-acetyl-D,L-penicillamine (SNAP), a nitrogen-derived reactive species donor. We found that the resistance to SNAP of different species of Leishmania was inversely correlated with their glutathione concentration but not with their total low-molecular weight thiol content (about 0.18 nmol/10(7) parasites, regardless Leishmania species). The glutathione concentration in L. amazonensis, L. donovani, L. major, and L. braziliensis were 0.12, 0.10, 0.08, and 0.04 nmol/10(7) parasites, respectively. L. amazonensis, that have a higher level of glutathione, were less susceptible to SNAP (30 and 100 microM). The IC50 values of SNAP determined to L. amazonensis, L. donovani, L. major, and L. braziliensis were 207.8, 188.5, 160.9, and 83 microM, respectively. We also observed that L. donovani mutants carrying only one trypanothione reductase allele had a decreased capacity to survive (approximately 40%) in the presence of SNAP (30-150 microM). In conclusion, the present data suggest that both antioxidant systems, glutathione and trypanothione/trypanothione reductase, participate in protection of Leishmania against the toxic effect of nitrogen-derived reactive species.


Asunto(s)
Glutatión/metabolismo , Leishmania/efectos de los fármacos , NADH NADPH Oxidorreductasas/metabolismo , Penicilamina/análogos & derivados , Animales , Fluoresceínas , Leishmania/enzimología , Peso Molecular , NADH NADPH Oxidorreductasas/genética , Ouabaína/análogos & derivados , Penicilamina/toxicidad , Especificidad de la Especie
10.
J Comp Pathol ; 155(2-3): 181-184, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27392423

RESUMEN

A testicular Leydig cell tumour associated with metastatic disease is reported in a dog. An enlarged testis and three cutaneous nodules resected from an 11-year-old golden retriever were submitted for histopathological examination. Both testicular and cutaneous lesions showed identical morphological and cytological changes. Immunohistochemical labelling for expression of inhibin-α and calretinin confirmed the Leydig origin of the cutaneous neoplastic population. Based on the morphological and immunohistochemical findings, a final diagnosis of multiple cutaneous metastasis of a malignant testicular Leydig cell tumour was made.


Asunto(s)
Enfermedades de los Perros/patología , Tumor de Células de Leydig/veterinaria , Neoplasias Testiculares/veterinaria , Animales , Biomarcadores de Tumor/análisis , Perros , Inmunohistoquímica , Masculino , Neoplasias Cutáneas/veterinaria
11.
Vet Immunol Immunopathol ; 79(3-4): 273-84, 2001 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-11389961

RESUMEN

In the present study, we have followed up Leishmania infantum infection in dogs: (1) naturally infected; (2) experimentally infected with amastigotes; and (3) experimentally infected with culture promastigotes. The main objective was to evaluate the differences of the humoral and cellular immune responses of each group. Sera from 12 beagle dogs were analysed for total anti-leishmanial antibodies and IgG1 and IgG2 subclasses by enzyme-linked immunosorbent assay (ELISA). Lymphoproliferation to L. infantum antigen was also performed. All naturally infected animals were symptomatic with a marked humoral response. Dogs inoculated with amastigotes were asymptomotic and presented lower antibody titres than naturally infected. Dogs inoculated with culture promastigotes were asymptomotic with no significant humoral response. Strong proliferative responses to Leishmania antigen was observed in dogs inoculated with promastigotes. In our experimental model, IgG1 antibody levels presented a similar pattern in all infected animals, and IgG2 reactivity was high in naturally infected dogs.


Asunto(s)
Anticuerpos Antiprotozoarios/biosíntesis , Enfermedades de los Perros/inmunología , Inmunoglobulina G/biosíntesis , Leishmania infantum/inmunología , Leishmaniasis Visceral/veterinaria , Animales , Anticuerpos Antiprotozoarios/sangre , Especificidad de Anticuerpos/inmunología , Antígenos de Protozoos/inmunología , Médula Ósea/parasitología , Enfermedades de los Perros/parasitología , Perros , Ensayo de Inmunoadsorción Enzimática/veterinaria , Inmunidad Celular/inmunología , Inmunoglobulina G/clasificación , Inmunoglobulina G/inmunología , Leishmaniasis Visceral/inmunología , Leishmaniasis Visceral/parasitología , Estudios Longitudinales , Ganglios Linfáticos/parasitología , Activación de Linfocitos/inmunología , Piel/parasitología , Estadísticas no Paramétricas
12.
Res Vet Sci ; 95(3): 1134-41, 2013 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-24012348

RESUMEN

In order to improve the understanding of the toxicity of pentavalent antimony (Sb(V)), we investigated the acute effects of meglumine antimoniate (MA) on the oxidative stress in heart, liver, kidney, spleen and brain tissue of mice. Levels of lipoperoxidation and protein carbonylation were measured to evaluate the oxidative status, whereas superoxide dismutase/catalase activity and glutathione levels were recorded to examine the antioxidative status. We observed that MA caused significant protein carbonylation in the heart, spleen and brain tissue. Increased lipoperoxidation was found in the liver and brain tissue. An imbalance between superoxide dismutase and catalase activities could be observed in heart, liver, spleen and brain tissue. Our results suggest that MA causes oxidative stress in several vital organs of mice. This indicates that the production of highly reactive oxygen and nitrogen species induced by MA might be involved in some of its toxic adverse effects.


Asunto(s)
Antiprotozoarios/farmacología , Meglumina/farmacología , Compuestos Organometálicos/farmacología , Estrés Oxidativo/efectos de los fármacos , Animales , Antiprotozoarios/efectos adversos , Encéfalo/efectos de los fármacos , Química Encefálica/efectos de los fármacos , Catalasa/metabolismo , Glutatión/análisis , Corazón/efectos de los fármacos , Riñón/química , Riñón/efectos de los fármacos , Peroxidación de Lípido/efectos de los fármacos , Hígado/química , Hígado/efectos de los fármacos , Meglumina/efectos adversos , Antimoniato de Meglumina , Ratones , Miocardio/química , Compuestos Organometálicos/efectos adversos , Carbonilación Proteica/efectos de los fármacos , Bazo/química , Bazo/efectos de los fármacos , Superóxido Dismutasa/metabolismo
13.
Physiol Behav ; 102(1): 115-20, 2011 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-20888354

RESUMEN

Clinical findings reveal that middle-aged patients are more susceptible to suffer from psychiatric disorders than older ones. However, little is known about the emotional behavior of aging rodents. This study aimed to investigate behavioral alterations in male middle-aged Wistar rats in the open-field (OF) test (at illuminated and dimly light conditions), elevated plus maze (EPM), forced swimming (FST) and inhibitory avoidance task (IA). In the EPM, middle-aged rats displayed reduced percentages of the time spent in and entries into open arms. The ambulatory activity measured in the OF under dimly light conditions was identical among groups. However, under illuminated conditions, a reduction in the number of crossings was detected in older rats, reinforcing that aged animals display a genuine anxiogenic-like phenotype. Additionally, aged rats showed an increase in the immobility time in the FST, and a reduction in the latency to step down the platform in the IA. A negative correlation was found between the immobility time and latency to step down the platform, suggesting a relationship between depressive-behavior and cognitive impairment in old rats. Altogether, male middle-aged rats are more anxious, depressed, and display aversive memory impairments. These observations contribute to investigate biological mechanisms and therapeutic interventions for geriatric anxiety and depression.


Asunto(s)
Ansiedad/psicología , Depresión/psicología , Trastornos de la Memoria/psicología , Factores de Edad , Animales , Reacción de Prevención , Peso Corporal , Modelos Animales de Enfermedad , Inhibición Psicológica , Masculino , Aprendizaje por Laberinto , Actividad Motora , Ratas , Ratas Wistar , Natación
14.
Parasite Immunol ; 20(9): 405-12, 1998 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9767607

RESUMEN

In order to investigate the ability of rat peritoneal eosinophils to produce nitric oxide (NO) induced by cytokines in vitro, these cells were activated with several cytokines (IL-5, IL-8, Rantes, TNF-alpha, IFN-gamma) in association or not with LPS. Under these conditions, we were able to detect nitrite in the incubation medium when the eosinophils were stimulated with IFN-gamma or IL-8 in the presence of LPS. LPS alone also induced nitrite production. Significant levels of nitrite in the medium were already present after 12 h of stimulation and increased steadily within the next 48 h. Regarding NO synthase, its highest activity was achieved at 12 h after IFN-gamma/LPS stimulation. After this peak, the enzymatic activity reduced gradually to control levels 48 h after the stimulation. The simultaneous addition of the NO synthase inhibitor L-NIO (100 microM) to the eosinophil suspension blocked nitrite production and NO synthase activity. On the other hand, neither IL-5, Rantes nor TNF-alpha were able to induce the release of nitrite in the presence or absence of LPS. To evaluate the microbicidal effect of these cells against the Leishmania parasite, eosinophils were infected with Leishmania major. It was observed that these cells were able to produce nitrite and to kill the parasite after activation with LPS/IFN-gamma. Moreover, L-NIO blocked this leishmanicidal activity and the nitrite production. Our results suggest that activated eosinophils release NO which is involved in their microbicidal activity against Leishmania major.


Asunto(s)
Arginina/fisiología , Eosinófilos/inmunología , Eosinófilos/parasitología , Óxido Nítrico/fisiología , Animales , Citocinas/farmacología , Eosinófilos/fisiología , Técnicas In Vitro , Interferón gamma/farmacología , Leishmania major/inmunología , Lipopolisacáridos/farmacología , Óxido Nítrico Sintasa/metabolismo , Cavidad Peritoneal/citología , Ratas , Ratas Wistar , Proteínas Recombinantes
15.
Mem Inst Oswaldo Cruz ; 92 Suppl 2: 233-5, 1997.
Artículo en Inglés | MEDLINE | ID: mdl-9698941

RESUMEN

There are several experimental evidences that nitric oxide (NO) is involved in the microbicidal activity of macrophages against a number of intracellular pathogens including Leishmania major, Trypanozoma cruzi, Toxoplasma gondii. It is also well known that eosinophils (EO) have microbicidal activity against many parasites such as Schistosoma mansoni, Trichinella spiralis, T. cruzi and L. amazonensis. The purpose of this study was to investigate if NO is involved in the microbicidal activity of EO against L. major. Eosinophils harvested from peritoneal cavity of rats released spontaneously after 24 and 48 hr a small amount of nitrite. This release was enhanced by the treatment of cells with IFN-gamma (200 IU/ml). This release was blocked by addition of the NO synthase inhibitor, L-NIO (100 microM) into the culture. To determinate the leishmanicidal activity of eosinophils the parasites were incubated with activated eosinophils with IFN-gamma and the ability of surviving parasites to incorporate [(3)H] thymidine was evaluated. IFN-gamma-activated eosinophils were able to kill L. major and to release high levels of nitrite. The ability to destroy L. major and the release of NO were completely blocked by L-NIO. These results indicate that activated eosinophils release NO which is involved in the microbicidal activity of these cells against L. major.


Asunto(s)
Eosinófilos/fisiología , Leishmania major , Óxido Nítrico/fisiología , Análisis de Varianza , Animales , Antivirales/farmacología , Interferón gamma , Ornitina/análogos & derivados , Ornitina/efectos de los fármacos , Cavidad Peritoneal , Ratas
16.
Parasitology ; 118 ( Pt 6): 559-66, 1999 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10406034

RESUMEN

The aim of this investigation was to examine whether macrophage and Leishmania major glutathione were involved in either host or parasite protection against NO cytotoxicity. Buthionine sulfoximine (BSO), an inhibitor of gamma-glutamylcysteine synthase, caused a complete and irreversible depletion of macrophage glutathione, but only a 20% and reversible decrease in L. major glutathione. Glutathione-depleted macrophages, when activated with IFN-gamma/LPS, released less than 60% of the NO produced by untreated macrophages, resulting in a corresponding decrease in their leishmanicidal activity. BSO-treated macrophages were more susceptible to the cytotoxic effects of the NO donor SNAP. Treatment of macrophages with 1,3-bis(chloroethyl)-1-nitrosourea (BCNU), an inhibitor of glutathione reductase and trypanothione reductase or with Br-Octane, a glutathione-S-transferase substrate, resulted in a transient decrease in glutathione levels and did not increase the susceptibility of the macrophages to SNAP. Treatment of the promastigote forms of L. major with BCNU resulted in an 80% decrease in total glutathione concentration with no concomitant change in viability. However, this treatment rendered the parasites more susceptible to SNAP. Finally, macrophage glutathione protected the internalized L. major from SNAP. Overall, these results demonstrate that glutathione is an essential protective component against NO cytotoxicity on both macrophages and parasites.


Asunto(s)
Glutatión/metabolismo , Leishmania major/metabolismo , Macrófagos Peritoneales/metabolismo , Óxido Nítrico/metabolismo , Animales , Butionina Sulfoximina/farmacología , Carmustina/farmacología , Supervivencia Celular/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Glutatión/efectos de los fármacos , Leishmania major/efectos de los fármacos , Macrófagos Peritoneales/efectos de los fármacos , Macrófagos Peritoneales/parasitología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Óxido Nítrico/antagonistas & inhibidores , Penicilamina/análogos & derivados , Penicilamina/farmacología
17.
Braz. j. med. biol. res ; 39(3): 355-363, Mar. 2006. tab
Artículo en Inglés | LILACS | ID: lil-421363

RESUMEN

Glutathione is the major intracellular antioxidant thiol protecting mammalian cells against oxidative stress induced by oxygen- and nitrogen-derived reactive species. In trypanosomes and leishmanias, trypanothione plays a central role in parasite protection against mammalian host defence systems by recycling trypanothione disulphide by the enzyme trypanothione reductase. Although Kinetoplastida parasites lack glutathione reductase, they maintain significant levels of glutathione. The aim of this study was to use Leishmania donovani trypanothione reductase gene mutant clones and different Leishmania species to examine the role of these two individual thiol systems in the protection mechanism against S-nitroso-N-acetyl-D,L-penicillamine (SNAP), a nitrogen-derived reactive species donor. We found that the resistance to SNAP of different species of Leishmania was inversely correlated with their glutathione concentration but not with their total low-molecular weight thiol content (about 0.18 nmol/10(7) parasites, regardless Leishmania species). The glutathione concentration in L. amazonensis, L. donovani, L. major, and L. braziliensis were 0.12, 0.10, 0.08, and 0.04 nmol/10(7) parasites, respectively. L. amazonensis, that have a higher level of glutathione, were less susceptible to SNAP (30 and 100 µM). The IC50 values of SNAP determined to L. amazonensis, L. donovani, L. major, and L. braziliensis were 207.8, 188.5, 160.9, and 83 µM, respectively. We also observed that L. donovani mutants carrying only one trypanothione reductase allele had a decreased capacity to survive (40 percent) in the presence of SNAP (30-150 µM). In conclusion, the present data suggest that both antioxidant systems, glutathione and trypanothione/trypanothione reductase, participate in protection of Leishmania against the toxic effect of nitrogen-derived reactive species.


Asunto(s)
Animales , Glutatión/metabolismo , Leishmania/efectos de los fármacos , NADH NADPH Oxidorreductasas/metabolismo , Penicilamina/análogos & derivados , Fluoresceínas , Leishmania/enzimología , Peso Molecular , NADH NADPH Oxidorreductasas/genética , Ouabaína/análogos & derivados , Penicilamina/toxicidad , Especificidad de la Especie
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