RESUMO
In this research, we present a study on the atomization threshold (ATh) of sessile droplets, analyzing its relationship with the excitation frequency fexc (55-48 kHz), droplet volume Vdrop (1-100 µl), and droplet viscosity µ (1-6 mPaâ s). The investigation focused on the atomization thresholds using ultrasonic excitation of distilled water droplets and water- polyethylene glycol (PEG)-8000 mixtures deposited on vibrating surfaces. The obtained results are compared with previously reported theoretical models. A modification to the model proposed by Alzuaga et al. [Alzuaga, Manceau, and Bastien, J. Sound Vib. 282(1-2), 151-162 (2005)] is suggested to determine the atomization thresholds of sessile droplets, incorporating the atomization droplet size equation proposed by Rajan and Pandit and an empirical constant α to account for the effect of droplet volume in this process. The results show that the relationship between the atomization threshold and viscosity does not fit well with the prediction of Eisenmenger [Acta Acust united Acust. 9(4), 327-340 (1959)] and Pohlman and Stamm [Untersuchung Zum Mechanismus Der Ultraschallvernebelung an Flüssigkeitsoberflächen im Hinblick Auf Technische Anwendungen (Investigation on the Mechanism of Ultrasonic Nebulization on Liquid Surfaces Considering Technical Applications) (VS Verlag für Sozialwissenschaften, Wiesbaden, Germany, 1965)] and Pohlman et al. [Pohlman, Heisler, and Cichos, Ultrasonicc 12(1), 11-15 (1974)] (AThâµ). However, the data tendency aligns with the model proposed by Alzuaga (ATh â µ1/2). The results obtained in this study provide a deeper understanding of the atomization thresholds of sessile droplets through ultrasonic excitation.
RESUMO
Chagas disease is caused by the parasite Trypanosoma cruzi. In humans, it evolves into a chronic disease, eventually resulting in cardiac, digestive, and/or neurological disorders. In the present study, we characterized a novel T. cruzi antigen named Tc323 (TcCLB.504087.20), recognized by a single-chain monoclonal antibody (scFv 6B6) isolated from the B cells of patients with cardiomyopathy related to chronic Chagas disease. Tc323, a ~323 kDa protein, is an uncharacterized protein showing putative quinoprotein alcohol dehydrogenase-like domains. A computational molecular docking study revealed that the scFv 6B6 binds to an internal domain of Tc323. Immunofluorescence microscopy and Western Blot showed that Tc323 is expressed in the main developmental forms of T. cruzi, localized intracellularly and exhibiting a membrane-associated pattern. According to phylogenetic analysis, Tc323 is highly conserved throughout evolution in all the lineages of T. cruzi so far identified, but it is absent in Leishmania spp. and Trypanosoma brucei. Most interestingly, only plasma samples from patients infected with T. cruzi and those with mixed infection with Leishmania spp. reacted against Tc323. Collectively, our findings demonstrate that Tc323 is a promising candidate for the differential serodiagnosis of chronic Chagas disease in areas where T. cruzi and Leishmania spp. infections coexist.
Assuntos
Doença de Chagas , Leishmania , Trypanosoma cruzi , Humanos , Simulação de Acoplamento Molecular , Filogenia , Doença de Chagas/diagnóstico , Anticorpos MonoclonaisRESUMO
Despite the growing importance of the regulatory function of B cells in many infectious diseases, their immunosuppressive role remains elusive in chronic Chagas disease (CCD). Here, we studied the proportion of different B cell subsets and their capacity to secrete IL-10 ex vivo in peripheral blood from patients with or without CCD cardiomyopathy. First, we immunophenotyped peripheral blood mononuclear cells from patients according to the expression of markers CD19, CD24, CD38 and CD27 and we showed an expansion of total B cell and transitional CD24highCD38high B cell subsets in CCD patients with cardiac involvement compared to non-infected donors. Although no differences were observed in the frequency of total IL-10 producing B cells (B10) among the groups, CCD patients with cardiac involvement showed an increased proportion of naïve B10 cells and a tendency to a higher frequency of transitional B10 cells compared to non-infected donors. Our research demonstrates that transitional B cells are greatly expanded in patients with the cardiac form of CCD and these cells retain the ability to secrete IL-10. These findings provide insight into the phenotypic distribution of regulatory B cells in CCD, an important step towards new strategies to prevent cardiomyopathy associated with T. cruzi infection.
Assuntos
Antígenos CD/imunologia , Linfócitos B Reguladores/imunologia , Doença de Chagas/imunologia , Interleucina-10/imunologia , Adulto , Linfócitos B Reguladores/patologia , Doença de Chagas/patologia , Doença Crônica , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
Trypanosoma cruzi cytosolic tryparedoxin peroxidase (c-TXNPx) is a 2-Cys peroxiredoxin (Prx) with an important role in detoxifying host cell oxidative molecules during parasite infection. c-TXNPx is a virulence factor, as its overexpression enhances parasite infectivity and resistance to exogenous oxidation. As Prxs from other organisms possess immunomodulatory properties, we studied the effects of c-TXNPx in the immune response and analysed whether the presence of the peroxidatic cysteine is necessary to mediate these properties. To this end, we used a recombinant c-TXNPx and a mutant version (c-TXNPxC52S) lacking the peroxidatic cysteine. We first analysed the oligomerization profile, oxidation state and peroxidase activity of both proteins by gel filtration, Western blot and enzymatic assay, respectively. To investigate their immunological properties, we analysed the phenotype and functional activity of macrophage and dendritic cells and the T-cell response by flow cytometry after injection into mice. Our results show that c-TXNPx, but not c-TXNPxC52S, induces the recruitment of IL-12/23p40-producing innate antigen-presenting cells and promotes a strong specific Th1 immune response. Finally, we studied the cellular and humoral immune response developed in the context of parasite natural infection and found that only wild-type c-TXNPx induces proliferation and high levels of IFN-γ secretion in PBMC from chronic patients without demonstrable cardiac manifestations. In conclusion, we demonstrate that c-TXNPx possesses pro-inflammatory properties that depend on the presence of peroxidatic cysteine that is essential for peroxidase activity and quaternary structure of the protein and could contribute to rational design of immune-based strategies against Chagas disease.
Assuntos
Doença de Chagas/metabolismo , Citocinas/metabolismo , Mediadores da Inflamação/metabolismo , Ativação Linfocitária , Peroxidases/metabolismo , Proteínas de Protozoários/metabolismo , Células Th1/metabolismo , Trypanosoma cruzi/enzimologia , Imunidade Adaptativa , Adulto , Idoso , Animais , Estudos de Casos e Controles , Proliferação de Células , Células Cultivadas , Doença de Chagas/imunologia , Doença de Chagas/parasitologia , Feminino , Interações Hospedeiro-Parasita , Humanos , Imunidade Inata , Masculino , Camundongos Endogâmicos BALB C , Pessoa de Meia-Idade , Mutação , Peroxidases/genética , Peroxidases/imunologia , Estrutura Quaternária de Proteína , Proteínas de Protozoários/genética , Proteínas de Protozoários/imunologia , Relação Estrutura-Atividade , Células Th1/imunologia , Células Th1/parasitologia , Trypanosoma cruzi/genética , Trypanosoma cruzi/imunologiaRESUMO
ABSTRACT: Physalis ixocarpa Brot. (tomatillo or Husk tomato) is one of the five major vegetables cultivated in Mexico, but its yield in the field is low. However, greenhouse crops and the enhancement in plant density can promote an increase in yield per area. The aim of this research was to evaluate: yield, water consumption and water use efficiency of variety husk tomato 'Diamante'. The experiment was conducted under field and greenhouse conditions, during the two crop cycles (autumn-winter and spring-summer), with different planting densities (1.5, 2 and 3 plants m-2), in complete random blocks and three replications. The yield was influenced by the planting density and environments. In both environments, the planting density, with 3 plants m-2 increased yield 32 %, and 25% in water use efficiency (WUE). In greenhouse increased 32% yield m-2 and the WUE it was 18.1 kg m-3 while in the field was 16.4 kg m-3. Crop cycle spring-summer produced differences of 27% in plant length and 15% in stem diameter, probably due to the temperature that was 4 ºC higher with respect to autumn-winter.
RESUMO: Physalis ixocarpa Brot. (tomatillo ou tomate de cáscara) é um dos cinco principais vegetais cultivados no México, mas seu rendimento no campo é baixo. No entanto, as culturas em estufa e o aumento da densidade das plantas podem promover um aumento no rendimento por área. O objetivo desta pesquisa foi avaliar: rendimento, consumo de água e eficiência no uso da água do tomate de casca de variedade 'Diamante'. O experimento foi conduzido em condições de campo e casa de vegetação, durante os dois ciclos de cultivo (outono-inverno e primavera-verão), com diferentes densidades de plantio (1,5, 2 e 3 plantas m-2), em blocos aleatórios completos e três replicações. O rendimento foi influenciado pela densidade e pelos ambientes de plantio. Nos dois ambientes, a densidade de plantio, com três plantas m-2, aumentou a produtividade em 32% e em 25% na eficiência no uso da água (WUE). Em casa de vegetação aumentou 32% do rendimento m-2 e o WUE foi de 18,1 kg m-3, enquanto no campo foi de 16,4 kg m-3. O ciclo da safra primavera-verão produziu diferenças de 27% no comprimento das plantas e 15% no diâmetro do caule, provavelmente devido à temperatura 4 ºC maior em relação ao outono-inverno.
RESUMO
Physalis ixocarpa Brot. (tomatillo or Husk tomato) is one of the five major vegetables cultivated in Mexico, but its yield in the field is low. However, greenhouse crops and the enhancement in plant density can promote an increase in yield per area. The aim of this research was to evaluate: yield, water consumption and water use efficiency of variety husk tomato Diamante. The experiment was conducted under field and greenhouse conditions, during the two crop cycles (autumn-winter and spring-summer), with different planting densities (1.5, 2 and 3 plants m-2), in complete random blocks and three replications. The yield was influenced by the planting density and environments. In both environments, the planting density, with 3 plants m-2 increased yield 32 %, and 25% in water use efficiency (WUE). In greenhouse increased 32% yield m-2 and the WUE it was 18.1 kg m-3 while in the field was 16.4 kg m-3. Crop cycle spring-summer produced differences of 27% in plant length and 15% in stem diameter, probably due to the temperature that was 4 ºC higher with respect to autumn-winter.(AU)
Physalis ixocarpa Brot. (tomatillo ou tomate de cáscara) é um dos cinco principais vegetais cultivados no México, mas seu rendimento no campo é baixo. No entanto, as culturas em estufa e o aumento da densidade das plantas podem promover um aumento no rendimento por área. O objetivo desta pesquisa foi avaliar: rendimento, consumo de água e eficiência no uso da água do tomate de casca de variedade Diamante. O experimento foi conduzido em condições de campo e casa de vegetação, durante os dois ciclos de cultivo (outono-inverno e primavera-verão), com diferentes densidades de plantio (1,5, 2 e 3 plantas m-2), em blocos aleatórios completos e três replicações. O rendimento foi influenciado pela densidade e pelos ambientes de plantio. Nos dois ambientes, a densidade de plantio, com três plantas m-2, aumentou a produtividade em 32% e em 25% na eficiência no uso da água (WUE). Em casa de vegetação aumentou 32% do rendimento m-2 e o WUE foi de 18,1 kg m-3, enquanto no campo foi de 16,4 kg m-3. O ciclo da safra primavera-verão produziu diferenças de 27% no comprimento das plantas e 15% no diâmetro do caule, provavelmente devido à temperatura 4 ºC maior em relação ao outono-inverno.(AU)
Assuntos
Solanum lycopersicum/crescimento & desenvolvimento , Água/análiseRESUMO
The diversity of chilis in Oaxaca is one of the most extensive in Mexico. Growers select seeds in the traditional manner; information on its quality is unknown. The aim of this research was to compare the physical and physiological quality of seeds and seedlings of three native types to chili (Huacle, De agua and Pasilla) and of the commercial Green pepper as control. Fifteen variables were evaluated in seed and twelve in seedlings. The laboratory experiments were established under a completely randomized design. Means of the variables were compared using the Tukey test (=0.05). Results showed that Pasilla chili had the highest values in seed size and weight, which was 1.44 g heavier than the control and 2.09 to 3.73 g higher than native types. Haucle chili and green pepper had a 90% germination rate, while chili De agua and Pasilla chili had germination rates of 51 and 38%, respectively. Huacle chili had the highest germination rate index (29.89) and seedling vigor index (992.25). The top highest values of number of normal seedlings were obtained in the control and Huacle chili seedlings (72 and 88%); also, the latter had the longest plumule (3.36 cm) and radicle (7.67 cm) values. Both Huacle and Pasilla chili seedlings had larger values in height, stem thickness, number of leaves, leaf area and slenderness index than De agua and Green pepper. Huacle chili had good physical and physiological quality similar to the seeds of the commercial Green pepper.(AU)
Oaxaca é umas das regiões de maior diversidade de espécies de pimentas do México. Os agricultores selecionam sementes da maneira tradicional; informações sobre sua qualidade são desconhecidas. O objetivo desta pesquisa foi comparar a qualidade física e fisiológica de sementes e mudas de três tipos nativos de pimenta (Huacle, De Agua e Pasilla) e pimenta verde comercial como controle. Quinze variáveis foram avaliadas em sementes e doze em mudas. As experiências de laboratório foram estabelecidas sob um delineamento inteiramente casualizado. As médias das variáveis foram comparadas pelo teste de Tukey (=0.05). Os resultados mostraram que o Pasilla apresentou os maiores valores em tamanho e peso de sementes, 1,44 g mais pesado que o controle e 2,09 a 3,73 g maior que os demais tipos de pimenta nativa. A pimenta Huacle e a pimenta verde tiveram 90% de germinação de 90%, enquanto que De Agua e Pasilla foi de 51 e 38%, respectivamente. A pimienta Huacle apresentou os maiores índices de taxa de germinação (29,89) e de vigor de plântulas (992,25). Os maiores valores máximos no número de mudas normais foram obtidos no controle e na pimenta Huacle (72 e 88%). Além disso, este último apresentou os maiores valores de plúmula (3,36 cm) e radícula (7,67 cm). As mudas do Huacle e Pasilla apresentaram maiores valores em altura, espessura do caule, número de folhas, área foliar e índice de esbelto em relação à pimenta, De agua e ao controle. O Huacle apresentou boa qualidade física e fisiológica, semelhante às sementes da pimentão comercial.(AU)
Assuntos
Sementes , Plântula , Capsicum/crescimento & desenvolvimento , Capsicum/fisiologia , Pimenta , GerminaçãoRESUMO
In a pilot study, we showed that the intermittent administration of benznidazole in chronic Chagas disease patients resulted in a low rate of treatment suspension and therapeutic failure, as assessed by quantitative PCR (qPCR) at the end of treatment. Here, a 3-year posttreatment follow-up study of the same cohort of patients is presented. The treatment scheme consisted of 12 doses of benznidazole at 5 mg/kg of body weight/day in two daily doses every 5 days. Parasite load, Trypanosoma cruzi-specific antibodies, and serum chemokine levels were measured prior to treatment and after a median follow-up of 36 months posttreatment by DNA minicircle kinetoplastid and nuclear DNA satellite sequence qPCR methods, conventional serological techniques, a Luminex-based assay with recombinant T. cruzi proteins, and a cytometric bead array. At the end of follow-up, 14 of 17 (82%) patients had negative qPCR findings, whereas three of 17 (18%) had detectable nonquantiï¬able findings by at least one of the qPCR techniques. A decline in parasite-specific antibodies at 12 months posttreatment was confirmed by conventional serological tests and the Luminex assays. Monocyte chemoattractant protein 1 levels increased after treatment, whereas monokine induced by gamma interferon levels decreased. New posttreatment electrocardiographic abnormalities were observed in only one patient who had cardiomyopathy prior to treatment. Together, these data strengthen our previous findings by showing that the intermittent administration of benznidazole results in a low rate of treatment suspension, with treatment efficacy comparable to that of a daily dose of 5 mg/kg for 60 days.
Assuntos
Doença de Chagas , Nitroimidazóis , Tripanossomicidas , Trypanosoma cruzi , Doença de Chagas/tratamento farmacológico , Seguimentos , Humanos , Nitroimidazóis/uso terapêutico , Projetos Piloto , Tripanossomicidas/uso terapêuticoRESUMO
Evaluate the effect of a synbiotic on salivary viscosity and buffer capacity. Materials and Methods: A follow-up one-week study was performed on 24 healthy volunteers in San Luis Potosí, Mexico, during July 2017. Volunteers must have had active tooth decay at the moment of study. All 24 patients were given a Lactiv® probiotic package, advising not to modify usual oral hygiene practices, and were followed up during 6 days. Primary output variable was salivary viscosity while the secondary was salivary buffer capacity. Salivary viscosity was assessed by using an Ostwald Pipette and buffer capacity with bromocresol purple. Results: A total of 8 male patients (33.3%) and 16 females (66.6%) patients were included, with an average age of 10.92 years. All the volunteers completed the study. Comparisons between pre- and post-treatment showed a decrease in salivary viscosity, while buffer capacity was showed to increase. Conclusion: The use of a synbiotic during a short period of time lowered the viscosity of saliva and increased salivary buffer capacity.
Evaluar el efecto de un sinbiótico sobre la viscosidad salival y la capacidad de tampón de la saliva. Materiales and Métodos: Se realizó un estudio de seguimiento de una semana en 24 voluntarios sanos en San Luis Potosí, México, durante julio de 2017. Los voluntarios cursaban caries dental activa en el momento del estudio. Los 24 pacientes recibieron un paquete de probióticos Lactiv®, fueron aconsejados a no modificar las prácticas habituales de higiene oral, y fueron seguidos durante 6 días. La variable primaria fue la viscosidad salival mientras que la secundaria fue la capacidad tampón. La viscosidad salival se evaluó usando una pipeta Ostwald y capacidad tampón con bromocresol púrpura. Resultados: Se incluyeron un total de 8 pacientes varones (33,3%) y 16 mujeres (66,6%), con una edad promedio de 10,92 años. Todos los voluntarios completaron el estudio. Las comparaciones entre el pretratamiento y el postratamiento mostraron una disminución de la viscosidad salival, mientras que se demostró que la capacidad del tampón aumentó. Conclusión: El uso de un sinbiótico durante un corto período de tiempo mostró un efecto sobre la disminución de la viscosidad y el aumento de la capacidad del tampón salival.