Role of B lymphocytes in the infarcted mass in patients with acute myocardial infarction

Despite early reperfusion, patients with ST segment elevation myocardial infarction (STEMI) may present large myocardial necrosis and significant impairment of ventricular function. The present study aimed to evaluate the role of subtypes of B lymphocytes and related cytokines in the infarcted mass and left ventricular ejection fraction obtained by cardiac magnetic resonance imaging performed after 30 days of STEMI. This prospective study included 120 subjects with STEMI submitted to pharmacoinvasive strategy. Blood samples were collected in subjects in the first (D1) and 30th (D30) days post STEMI. The amount of CD11b+ B1 lymphocytes (cells/ml) at D1 were related to the infarcted mass (rho = 0.43; P=0.033), measured by cardiac MRI at D30. These B1 cells were associated with CD4+ T lymphocytes at D1 and D30, while B2 classic lymphocytes at day 30 were related to left ventricular ejection fraction (LVEF). Higher titers of circulating IL-4 and IL-10 were observed at D30 versus D1 (P=0.013 and P<0.001, respectively). Titers of IL-6 at D1 were associated with infarcted mass (rho = 0.41, P<0.001) and inversely related to LVEF (rho = −0.38, P<0.001). After multiple linear regression analysis, high-sensitivity troponin T and IL-6 collected at day 1 were independent predictors of infarcted mass and, at day 30, only HDL-C. Regarding LVEF, high-sensitivity troponin T and high-sensitivity C-reactive protein were independent predictors at day 1, and B2 classic lymphocytes, at day 30. In subjects with STEMI, despite early reperfusion, the amount of infarcted mass and ventricular performance were related to inflammatory responses triggered by circulating B lymphocytes.     

Genetic characterization of an elite coffee germplasm assessed by gSSR and EST-SSR markers

Coffee is one of the main agrifood commodities traded worldwide. In 2009, coffee accounted for 6.1% of the value of Brazilian agricultural production, generating a revenue of US$6 billion. Despite the importance of coffee production in Brazil, it is supported by a narrow genetic base, with few accessions. Molecular differentiation and diversity of a coffee breeding program were assessed with gSSR and EST-SSR markers. The study comprised 24 coffee accessions according to their genetic origin: arabica accessions (six traditional genotypes of C. arabica), resistant arabica (six leaf rust-resistant C. arabica genotypes with introgression of Híbrido de Timor), robusta (five C. canephora genotypes), Híbrido de Timor (three C. arabica x C. canephora), triploids (three C. arabica x C. racemosa), and racemosa (one C. racemosa). Allele and polymorphism analysis, AMOVA, the Student t-test, Jaccard's dissimilarity coefficient, cluster analysis, correlation of genetic distances, and discriminant analysis, were performed. EST-SSR markers gave 25 exclusive alleles per genetic group, while gSSR showed 47, which will be useful for differentiating accessions and for fingerprinting varieties. The gSSR markers detected a higher percentage of polymorphism among (35% higher on average) and within (42.9% higher on average) the genetic groups, compared to EST-SSR markers. The highest percentage of polymorphism within the genetic groups was found with gSSR markers for robusta (89.2%) and for resistant arabica (39.5%). It was possible to differentiate all genotypes including the arabica-related accessions. Nevertheless, combined use of gSSR and EST-SSR markers is recommended for coffee molecular characterization, because EST-SSRs can provide complementary information.     

Low Parasite Load Estimated by qPCR in a Cohort of Children Living in Urban Area Endemic for Visceral Leishmaniasis in Brazil

Background

An important issue associated with the control of visceral leishmaniasis is the need to identify and understand the relevance of asymptomatic infection caused by Leishmania infantum. The aim of this study was to follow the course of asymptomatic L. infantum infection in children in an area of Brazil where it is endemic. The children were assessed twice during a 12-month period.

Methodology

In this population study, 1875 children, ranging from 6 months to 7 years of age, were assessed. Blood samples were collected on filter papers via finger prick and tested by ELISA (L. infantum soluble antigen and rk39). Seropositives samples (n = 317) and a number of seronegatives samples (n = 242) were subjected to qPCR. After 12 months, blood samples were collected from a subgroup of 199 children and tested for Leishmania spp. to follow the course of infection.

Principal Findings

At baseline qPCR testing identified 82 positive samples. The prevalence rate, as estimated for 1875 children based on the qPCR results, was 13.9%. The qPCR testing of whole blood samples collected from a cohort of children after 12 months (n = 199) yielded the following results: of the 44 (22.1%) children with positive qPCR results at baseline, only 10 (5.0%) remained positive, and 34 (17.1%) became negative; and of the 155 (77.9%) children with negative qPCR results, 131 (65.8%) remained negative, and 24 (12.1%) became positive at the follow-up measurement. The samples with positive findings at baseline (n = 82) had a mean of 56.5 parasites/mL of blood; and at follow-up the mean positive result was 7.8 parasites/mL.

Conclusions

The peripheral blood of asymptomatic children had a low and fluctuating quantity of Leishmania DNA and a significant decrease in parasitemia at 1-year follow-up. Quantitative PCR enables adequate monitoring of Leishmania infection.     

Post-hatching development of bovine embryos in vitro: the effects of tunnel preparation and gender

The objective of this study was to compare morphological characteristics, kinetics of development, and gene expression of male and female IVP embryos that were cultured until day (D)15 (fertilization = D0), using either phosphate-buffered saline (PBS) or Milli-Q water (MQW) to dilute the agarose gel used for tunnel construction. On D11, embryos (n = 286) were placed in agarose gel tunnels diluted in PBS and MQW. Embryos were evaluated for morphology, and embryo size was recorded on D11, D12.5, D14 and D15. Then, embryos were sexed and used for gene expression analyses (G6PD, GLUT1, GLUT3, PGK1, PLAC8, KRT8, HSF1 and IFNT). The percentage of elongated embryos at D15 was higher (p < 0.05) in the PBS (54%) than in the MQW (42%) gel. However, embryos produced in MQW were bigger (p < 0.05) and had a lower expression of GLUT1 (p = 0.08) than those cultured in PBS. There was a higher proportion of male than female embryos at D15 in both treatments, MQW (65% vs. 35%; p < 0.05) and PBS (67% vs. 33%; p < 0.05); however, embryo size was not significantly different between genders. Moreover, D15 female embryos had greater expression of G6PD (p = 0.05) and KRT8 (p = 0.03) than male embryos. In conclusion, the diluent used for tunnel construction affected embryo development in the post-hatching development (PHD) system, and the use of MQW was the most indicative measure for the evaluation of embryo quality. Male and female embryos cultured from D11 to D15, either in an MQW or PBS agarose gel, demonstrated similar development but different gene expression.     

Synthesis of methoxylated goniothalamin, aza-goniothalamin and γ-pyrones and their in vitro evaluation against human cancer cells

The present work describes the preparation of three novel series of compounds based on the structure of goniothalamin, a natural styryl lactone which has been found to display cytotoxic and antiproliferative activities against a variety of cancer cell lines. A focused library of 29 novel goniothalamin analogues was prepared and evaluated against seven human cancer cell lines. While the γ-pyrones and the aza-goniothalamin analogues were less potent than the lead compound, 2,4-dimethoxy analogue 88 has shown to be more potent in vitro than goniothalamin against all cancer cell lines evaluated. Furthermore, it was more potent than doxorubicin against NCI-ADR/RES, OVCAR-03 and HT-29 while being less toxic to human keratinocytes (HaCat). The 3,5-dimethoxy analogue 90 and 2,4,5-trimethoxy analogue 92 also displayed promising antiproliferative activity when compared to goniothalamin (1). These results provide new elements for the design and synthesis of novel representatives of this family of natural compounds.     

Nitric oxide degradation by potato tuber mitochondria: evidence for the involvement of external NAD(P)H dehydrogenases

The mechanisms of nitric oxide (NO) synthesis in plants have been extensively investigated. NO degradation can be just as important as its synthesis in controlling steady-state levels of NO. Here, we examined NO degradation in mitochondria isolated from potato tubers and the contribution of the respiratory chain to this process. NO degradation was faster in mitochondria energized with NAD(P)H than with succinate or malate. Oxygen consumption and the inner membrane potential were transiently inhibited by NO in NAD(P)H-energized mitochondria, in contrast to the persistent inhibition seen with succinate. NO degradation was abolished by anoxia and superoxide dismutase, which suggested that NO was consumed by its reaction with superoxide anion (O2(-)). Antimycin-A stimulated and myxothiazol prevented NO consumption in succinate- and malate-energized mitochondria. Although favored by antimycin-A, NAD(P)H-mediated NO consumption was not abolished by myxothiazol, indicating that an additional site of O2(-) generation, besides complex III, stimulated NO degradation. Larger amounts of O2(-) were generated in NAD(P)H- compared to succinate- or malate-energized mitochondria. NAD(P)H-mediated NO degradation and O2(-) production were stimulated by free Ca2+ concentration. Together, these results indicate that Ca2+-dependent external NAD(P)H dehydrogenases, in addition to complex III, contribute to O2(-) production that favors NO degradation in potato tuber mitochondria.     

High-density genetic mapping for coffee leaf rust resistance

Coffee leaf rust caused by the fungus Hemileia vastatrix causes considerable economic losses for coffee producers. Although agrochemical products can provide sufficient disease control, the use of resistant cultivars is a safer alternative. This resistance may be constrained by one or a few genetic factors, mainly those found in material originating from interspecific hybrids. In this study, the genetic analysis of an F ₂ population consisting of 224 plants derived from a crossing of Híbrido de Timor UFV 427-15 (resistant) with Catuaí Amarelo IAC 30 (susceptible) showed that a dominant gene confers the resistance of coffee to race II of H. vastatrix. From a genetic map saturated with 25 amplified fragment length polymorphism (AFLP) markers linked to the resistance gene, we developed a high-density genetic map with six sequence-characterized amplified region (SCAR) markers delimiting a chromosomal region of 9.45 cM and flanking the dominant gene at 0.7 and 0.9 cM. This is the first saturated and high-density genetic map obtained from this region containing the resistance gene. The results of this study are of great importance for the introduction of molecular markers for marker-assisted selection; they will also facilitate studies related to the cloning, structure, and function of race-specific genes involved in the resistance of coffee trees to H. vastatrix.