Memory impairment has been associated with chronic Chagas disease (CD), a neglected tropical disease caused by the protozoan parasite Trypanosoma cruzi. In degenerative diseases, memory loss has been ...associated with increased oxidative stress, revealed as enhanced lipid peroxidation, in the cerebral cortex. Benznidazole (Bz), a trypanocidal drug efficient to reduce blood parasite load in the acute and chronic phases of infection, showed controversial effects on heart disease progression, the main clinical manifestation of CD. Here, we evaluated whether C57BL/6 mice infected with the Colombian type I T. cruzi strain present memory deficit assessed by (i) the novel object recognition task, (ii) the open field test and (iii) the aversive shock evoked test, at 120 days post infection (dpi). Next, we tested the effects of Bz therapy (25mg/Kg/day, for 30 consecutive days) on memory evocation, and tried to establish a relation between memory loss, parasite load and oxidative stress in the central nervous system (CNS). At 120 dpi, T. cruzi-infected mice showed memory impairment, compared with age-matched non-infected controls. Bz therapy (from 120 to 150 dpi) hampered the progression of habituation and aversive memory loss and, moreover, reversed memory impairment in object recognition. In vehicle-administered infected mice, neuroinflammation was absent albeit rare perivascular mononuclear cells were found in meninges and choroid plexus. Bz therapy abrogated the infiltration of the CNS by inflammatory cells, and reduced parasite load in hippocampus and cerebral cortex. At 120 and 150 dpi, lipid peroxidation was increased in the hippocampus and cortex tissue extracts. Notably, Bz therapy reduced levels of lipid peroxidation in the cerebral cortex. Therefore, in experimental chronic T. cruzi infection Bz therapy improved memory loss, in association with reduction of parasite load and oxidative stress in the CNS, providing a new perspective to improve the quality of life of Chagas disease patients.
ABSTRACT Although ferruginous materials occur frequently in soils of tropical regions, information about the reversal of the hardening process of these materials is scarce. This study assessed the ...influence of different chemical treatments and periods of immersion on the reversibility of the hardening process of plinthite and petroplinthite in soils of the Araguaia River plain. Soil samples were collected from the plinthic horizons in 0.10 m high and 0.15 m diameter PVC cylinders and divided into subsamples with a rock hammer. Homogeneous petroplinthite samples were also collected and broken into subsamples with a rock hammer. The plinthite and petroplinthite subsamples were subjected to five immersion treatments: distilled water, calcium carbonate solution, sodium hydroxide solution, sodium hydroxide solution + sodium hexametaphosphate, and acidic solution. The subsamples were immersed for 20, 40, 80, and 160 days. The dispersion and stability degrees and compressive strength in these subsamples were assessed. The wet aggregate stability test indicated no impact on the structural stability of plinthite and petroplinthite subsamples subjected to the treatment with different chemical agents, demonstrating the non-reversibility of the hardening process of these materials of the Araguaia River floodplain, under the studied conditions.
ABSTRACT Plinthite and petroplinthite occur frequently in Brazilian soils, but there is little information on the behavior of these materials. The aim of the present study was to assess the effect of ...different drying periods on the hardening and stability of plinthic materials of soils in the floodplain of the Araguaia River and the João Leite stream in Goiás. Soil samples were collected, with the aid of 0.10 m high and 0.15 m diameter PVC cylinders, directly from the plinthic horizons of five profiles of Plintossolos Argilúvicos (Plinthosols). Plinthite and soil matrix subsamples were obtained from these samples. Homogeneous petroplinthite samples were collected from the concretionary horizon of a Plintossolo Pétrico (Plinthosol) profile, and these were separated into subsamples with the aid of a rock hammer. All subsamples were dried in two manners: air drying and drying in a forced ventilation oven for 10, 20, 40, 80, and 160 days. Compressive strength and degree of stability were assessed. The results show a considerable variety of responses to the compressive force applied to the plinthite and petroplinthite samples in the same horizon and among the different profiles examined.
Chronic cardiomyopathy is the main clinical manifestation of Chagas disease (CD), a disease caused by
infection. A hallmark of chronic chagasic cardiomyopathy (CCC) is a fibrogenic inflammation ...mainly composed of CD8
and CD4
T cells and macrophages. CC-chemokine ligands and receptors have been proposed to drive cell migration toward the heart tissue of CD patients. Single nucleotide polymorphisms (SNPs) in CC-chemokine ligand and receptor genes may determine protein expression. Herein, we evaluated the association of SNPs in the CC-chemokines
(rs1024611) and
(rs2107538, rs2280788) and the CCL5/RANTES receptors
(rs3181077, rs1491961, rs3136672) and
(rs1799987) with risk and progression toward CCC. We performed a cross-sectional association study of 406 seropositive patients from endemic areas for CD in the State of Pernambuco, Northeast Brazil. The patients were classified as non-cardiopathic (A,
= 110) or cardiopathic (mild, B1,
= 163; severe, C,
= 133). Serum levels of CCL5 and CCL2/MCP-1 were elevated in CD patients but were neither associated with risk/severity of CCC nor with SNP genotypes. After logistic regression analysis with adjustment for the covariates gender and ethnicity,
-403 (rs2107538) CT heterozygotes (OR = 0.5,
-value = 0.04) and T carriers (OR = 0.5,
-value = 0.01) were associated with protection against CCC. To gain insight into the participation of the CCL5-CCR5/CCR1 axis in CCC, mice were infected with the Colombian
strain. Increased CCL5 concentrations were detected in cardiac tissue. In spleen, frequencies of CCR1
CD8
T cells and CD14
macrophages were decreased, while frequencies of CCR5
cells were increased. Importantly, CCR1
CD14
macrophages were mainly IL-10
, while CCR5
cells were mostly TNF
. CCR5-deficient infected mice presented reduced TNF concentrations and injury in heart tissue. Selective blockade of CCR1 (Met-RANTES therapy) in infected
mice supported a protective role for CCR1 in CCC. Furthermore, parasite antigen stimulation of CD patient blood cells increased the frequency of CCR1
CD8
T cells and CCL5 production. Collectively, our data support that a genetic variant of
and CCR1
cells confer protection against Chagas heart disease, identifying the CCL5-CCR1 axis as a target for immunostimulation.
The severity of chronic chagasic cardiomyopathy (CCC), the most frequent clinical outcome of Chagas disease (CD), has been associated with cytokine-enriched heart tissue inflammation, and high serum ...levels of transforming growth factor (TGFβ), interferon-gamma (IFNγ), and tumour necrosis factor (TNF). Conversely, increased interleukin (IL)-10 serum concentrations have been associated with asymptomatic CD. Cytokines and cytokine-related gene polymorphisms may control cytokine expression and have been proposed to contribute to CCC outcomes.
We evaluated the association of 13 cytokine-related genes (TGFB: rs8179181, rs8105161, rs1800469; IL10: rs1800890, rs1800871, rs1800896; IFNG: rs2430561; TNF: rs1800629; BAT1: rs3853601; LTA: rs909253, rs2239704; TNFR1: rs767455; TNFR2: rs1061624) with risk and progression of CCC.
Four hundred and six seropositive patients from CD endemic areas in the state of Pernambuco, north-eastern Brazil, were classified as non-cardiopathic (A, 110) or cardiopathic (mild, B1, 163; severe, C, 133). We found no evidence of TGFB, IL10, TNF, or TNFR1/2 gene polymorphisms associated with CCC risk or progression. Only BAT1 rs3853601 -22G carriers (B1 vs. C: OR = 0.5; p-value = 0.03) and IFNG rs2430561 +874AT (A vs. C: OR = 0.7; p-value = 0.03; A vs. B1+C: OR = 0.8; p-value = 0.02) showed a significant association with protection from cardiopathy in a logistic regression analysis with adjustment for gender and ethnicity; however, the association disappeared after performing adjustment for multiple testing. A systematic review of TNF rs1800629 -308G>A publications included five studies for meta-analysis (534 CCC and 472 asymptomatic patients) and showed no consensus in pooled odds ratio (OR) estimates for A allele or A carriers (OR = 1.4 and 1.5; p-values = 0.14 and 0.15, respectively). In CD patients, TNF serum levels were increased, but not affected by the TNF rs1800629 -308A allele.
Our data suggest no significant contribution of the analysed gene variants of cytokine-related molecules to development/severity of Chagas' heart disease, reinforcing the idea that parasite/host interplay is critical to CD outcomes.
The objective of this study was to evaluate different materials for field bagging with respect to the physicochemical changes caused in cantaloupe melon fruits. The study was conducted in a protected ...environment in the city of Goiânia, Goiás in Brazil. The experiment consisted of five treatments, with bagging of cantaloupe melon fruits with four materials (newspaper, Kraft paper, NWF, and polyethylene) and a control treatment without bagging, in a randomized block design with five replications of one plant with a fruit each. Fruits were evaluated for physicochemical characteristics. Number of days from bagging to harvest was also recorded and visual aspects of the fruit were observed. The materials as well as the time interval between the bagging and harvest affect physicochemical characteristics such as accumulation of soluble solids and thickness of the green pulp halo and visual aspects of the fruit. This study recommends bagging cantaloupe melons using white non-woven fabric or to not use the technique at all, under the conditions similar to those used in the study. In addition, using polyethylene for the bagging of fruit is not recommended, because this material has a deleterious effect on the characteristics essential for commercialization of melons.
RESUMO: Objetivou-se com este estudo avaliar diferentes materiais para ensacamento a campo quanto às alterações físico-químicas causadas em frutos de meloeiro Cantaloupe. O estudo foi conduzido em ambiente protegido localizado na cidade de Goiânia, Goiás. O experimento foi composto por cinco tratamentos, referentes ao ensacamento de frutos de meloeiro Cantaloupe com quatro materiais (papel jornal, papel Kraft, TNT e polietileno) e um tratamento controle, sem ensacamento, dispostos em blocos casualizados, com cinco repetições, representadas por uma planta com um fruto cada. Os frutos foram avaliados quanto às características físico-químicas. Também foi contabilizado o número de dias desde o ensacamento até a colheita e observados os aspectos visuais dos frutos. Verificou-se que os materiais influenciaram as características relativas ao acúmulo de sólidos solúveis e espessura do halo verde da polpa, o intervalo de tempo entre o ensacamento e a colheita e os aspectos visuais dos frutos. Recomenda-se o ensacamento de melões Cantaloupe com a utilização do TNT ou a não utilização da técnica, em condições semelhantes às do estudo. Em complemento, não é recomendada a utilização do polietileno para o ensacamento dos frutos, uma vez que esse material tem efeito deletério sobre as características essenciais à comercialização.
Chagas disease in the chronic phase may develop into cardiac and/or
digestive forms. The pathogenesis of the disease is not yet clear and
studies have been carried out to elucidate the role of ...parasite
persistence in affected organs. The aim of this study was to detect and
quantify Trypanosoma cruzi in paraffin-embedded tissue samples from
chronic patients using NPCR (nested polymerase chain reaction) and QPCR
(quantitative polymerase chain reaction) methods. These results were
correlated to anatomopathological alterations in the heart and
gastrointestinal tract (GIT). Of the 23 patients studied, 18 presented
the cardiac form and five presented the cardiodigestive form of Chagas
disease. DNA samples were randomly isolated from formalin-fixed
paraffin-embedded sections of heart and GIT tissue of 23 necropsies and
were analyzed through NPCR amplification. T. cruzi DNA was detected by
NPCR in 48/56 (85.7%) heart and 35/42 (83.3%) GIT samples from patients
with the cardiac form. For patients with the cardiodigestive form, NPCR
was positive in 12/14 (85.7%) heart and in 14/14 (100%) GIT samples.
QPCR, with an efficiency of 97.6%, was performed in 13 samples (11 from
cardiac and 2 from cardiodigestive form) identified previously as
positive by NPCR. The number of T. cruzi copies was compared to heart
weight and no statistical significance was observed. Additionally, we
compared the number of copies in different tissues (both heart and GIT)
in six samples from the cardiac form and two samples from the
cardiodigestive form. The parasite load observed was proportionally
higher in heart tissues from patients with the cardiac form. These
results show that the presence of the parasite in tissues is essential
to Chagas disease pathogenesis.
Chagas disease, which is caused by Trypanosoma cruzi, is transmitted primarily by triatomine bugs, although the incidence of new cases has decreased as a result of vector control. In Brazil, most of ...those affected have the chronic form of the disease and are generally elderly individuals who require appropriate clinical follow-up. In this work, we undertook a descriptive study in which 85 patients were interviewed and blood samples were collected for molecular analyses based on the amplification of parasite satellite DNA. The cardiac form of the disease was the most prevalent among the patients and hypertension was the most frequent comorbidity; polypharmacy was detected in 34% of the cases. Serological tests were positive in 95% of cases while 36% were positive in nested-polymerase chain reaction. These findings indicate an increased use of medications and a larger number of age-related diseases in elderly patients with Chagas disease, even in patients with low parasitemia. We conclude that elderly patients with Chagas disease require special attention and that further studies should be done with elderly individuals who carry this disease.
Production diversification is one way to avoid losses due to market variations. Melons are among the species used for this purpose, however, little information is a limiting factor to production ...stimulation. The objective of this study was to estimate and evaluate the economic indicators of muskmelon (Cucumis melo L.) cultivation, defining the most appropriate plant spacing in the planting line. A randomized complete block design was used, with four replications of five treatments corresponding to planting spacing of 15, 25, 35, 45 and 55 cm. From the production data of each treatment, economic indicators related to costs and returns obtained with the melon crop were estimated. For the production of melons in a protected area of 300 m2, a total operating cost of $ 440.02 per production cycle was obtained. This amount was constituted by investments in manual operations, inputs, other expenses and interest of cost, which had a participation of 60.60%, 31.78%, 4.62% and 3.00%. The highest values of the economic indicators and the lower equilibrium and productivity prices were obtained for melons spaced 55 cm. The cultivation of muskmelons spaced 55 cm in the planting lines provides greater economic gains for this culture. This species can be used by farmers as an alternative to crops commonly grown in systems protected environment, but continuing studies should be performed to allow greater financial performance by optimizing the production system.
A cultura do feijoeiro é de grande importância socioeconômica em todas as regiões brasileiras. Seu cultivo, entretanto, ainda está relacionado a técnicas rudimentares que prejudicam a produtividade. ...O emprego de vitaminas contribui para a melhora do desenvolvimento vegetativo e reprodutivo, incrementando as condições fisiológicas das plantas. Assim, o estudo objetivou avaliar os efeitos da aplicação de niacina ou tiamina sobre as características de desenvolvimento vegetativo e produtivo do feijoeiro a partir do tratamento de sementes, conduzido em vasos. Dois experimentos foram conduzidos e, em ambos, os tratamentos foram definidos pela aplicação de Niacina ou Tiamina em cinco diferentes dosagens (0,00; 5,00; 10,00; 15,00 e 20,00 mg kg-1), juntamente com fungicida. Foram avaliadas variáveis ligadas à emergência das plântulas, ao desenvolvimento vegetativo e à produtividade de grãos. Verificou-se que, para o feijoeiro (cv. BRS Estilo), o pré-tratamento de sementes com niacina diminuiu o tempo de emergência das plântulas (20,31%) e estimulou o desenvolvimento dos trifólios (16,21%). A aplicação da tiamina, por sua vez, aumentou a emergência das plântulas na primeira contagem (287,52%), estimulou a taxa de emergência (36,72%) e o índice de velocidade de emergência (65,76%), diminuiu o tempo médio de emergência (19,03) e proporcionou incremento do número de vagens por planta (116,28%), de grãos por planta (122,28%) e da produtividade de grãos (127,50%), quando comparados ao tratamento controle.
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