Moniliophthora perniciosa Necrosis- and Ethylene-Inducing Protein 2 (MpNep2) as a Metastable Dimer in Solution: Structural and Functional Implications

Understanding how Nep-like proteins (NLPs) behave during the cell cycle and disease progression of plant pathogenic oomycetes, fungi and bacteria is crucial in light of compelling evidence that these proteins play a role in Witches` Broom Disease (WBD) of Theobroma cacao, one of the most important phytopathological problems to afflict the Southern Hemisphere. The crystal structure of MpNep2, a member of the NLP family and the causal agent of WBD, revealed the key elements for its activity. This protein has the ability to refold after heating and was believed to act as a monomer in solution, in contrast to the related homologs MpNep1 and NPP from the oomyceteous fungus Phytophthora parasitica. Here, we identify and characterize a metastable MpNep2 dimer upon over-expression in Escherichia coli using different biochemical and structural approaches. We found using ultra-fast liquid chromatography that the MpNep2 dimer can be dissociated by heating but not by dilution, oxidation or high ionic strength. Small-angle X-ray scattering revealed a possible tail-to-tail interaction between monomers, and nuclear magnetic resonance measurements identified perturbed residues involved in the putative interface of interaction. We also explored the ability of the MpNep2 monomer to refold after heating or chemical denaturation. We observed that MpNep2 has a low stability and cooperative fold that could be an explanation for its structure and activity recovery after stress. These results can provide new insights into the mechanism for MpNep2′s action in dicot plants during the progression of WBD and may open new avenues for the involvement of NLP- oligomeric species in phytopathological disorders.     

Active Surveillance of Hansen's Disease (Leprosy): Importance for Case Finding among Extra-domiciliary Contacts

Hansen''s disease (leprosy) remains an important health problem in Brazil, where 34,894 new cases were diagnosed in 2010, corresponding to 15.3% of the world''s new cases detected in that year. The purpose of this study was to use home visits as a tool for surveillance of Hansen''s disease in a hyperendemic area in Brazil. A total of 258 residences were visited with 719 individuals examined. Of these, 82 individuals had had a previous history of Hansen''s disease, 209 were their household contacts and 428 lived in neighboring residences. Fifteen new Hansen''s disease cases were confirmed, yielding a detection rate of 2.0% of people examined. There was no difference in the detection rate between household and neighbor contacts (p = 0.615). The two groups had the same background in relation to education (p = 0.510), household income (p = 0.582), and the number of people living in the residence (p = 0.188). Spatial analysis showed clustering of newly diagnosed cases and association with residential coordinates of previously diagnosed multibacillary cases. Active case finding is an important tool for Hansen''s disease control in hyperendemic areas, enabling earlier diagnosis, treatment, decrease in disability from Hansen''s disease and potentially less spread of Mycobacterium leprae.     

Draft genome sequence of Bizionia argentinensis, isolated from Antarctic surface water

A psychrotolerant marine bacterial strain, designated JUB59(T), was isolated from Antarctic surface seawater and classified as a new species of the genus Bizionia. Here, we present the first draft genome sequence for this genus, which suggests interesting features such as UV resistance, hydrolytic exoenzymes, and nitrogen metabolism.     

Skeletal mass in adolescent male athletes and nonathletes: relationships with high-impact sports

Dias Quiterio, AL, Canero, EA, Baptista, FM, and Sardinha, LB. Skeletal mass in adolescent male athletes and nonathletes: relationships with high-impact sports. J Strength Cond Res 25(12): 3439-3447, 2011-This study examined the relationships between the practice of different categories of sports (high-impact vs. nonimpact) and bone status in adolescent male athletes and investigated differences from an age-matched control group. A total of 54 adolescent male athletes and 26 adolescent nonathletes were evaluated. Bone mineral density, bone mineral content (BMC), and bone area at the whole-body, limbs, and lumbar spine were determined by dual-energy x-ray absorptiometry, along with total and regional fat-free mass and body fat. The high-impact group included 34 athletes: 9 gymnasts, 18 basketball players, and 7 handball players (age: 15.7 ± 1.6 years; weight: 72.0 ± 15.0 kg; height: 178.5 ± 12.5 cm). The nonimpact group consisted of 20 swimmers (age: 16.4 ± 2.5 years; weight: 66.9 ± 10.4 kg; height: 173.7 ± 10.9 cm). The nonathletic control group included 26 male adolescents (age: 15.9 ± 2.8 years; weight: 64.7 ± 16.3 kg; height: 168.6 ± 15.1 cm). No differences were observed between the nonimpact and the control group in all bone variables, before and after adjustments for maturation level, body weight, and height (p > 0.05). After adjustments for these variables, the high-impact group displayed greater bone mass in most of the measured sites when compared to the other 2 groups (p < 0.001). Subjects in the nonimpact group showed lower values of BMC, particularly in the lower limbs, than both the high-impact and the nonathletic control groups (p < 0.05) after adjustments for maturation, high, and fat-free mass. This study reinforces the positive associations between high-impact physical activities and skeletal health in adolescent boys.     

Efficient genome editing and gene knockout in Setaria viridis with CRISPR/Cas9 directed gene editing by the non-homologous end-joining pathway

The CRISPR/Cas9 system has been used for genome editing in several organisms, including higher plants. This system induces site-specific mutations in the genome based on the nucleotide sequence of engineered guide RNAs. The complex genomes of C4 grasses makes genome editing a challenge in key grass crops like maize (Zea mays), sorghum (Sorghum bicolor), Brachiaria spp., switchgrass (Panicum virgatum), and sugarcane (Saccharum spp.). Setaria viridis is a diploid C4 grass widely used as a model for these C4 crop plants. Here, an optimized CRISPR/Cas9 binary vector that exploits the non-homologous end joining (NHEJ) system was used to knockout a green fluorescent protein (gfp) transgene in S. viridis accession A10.1. Transformation of embryogenic callus by A. tumefaciens generated ten glufosinate-ammonium resistant transgenic events. In the T0 generation, 60% of the events were biallelic mutants in the gfp transgene with no detectable accumulation of GFP protein and without insertions or deletions in predicted off-target sites. The gfp mutations generated by CRISPR/Cas9 were stable and displayed Mendelian segregation in the T1 generation. Altogether, the system described here is a highly efficient genome editing system for S. viridis, an important model plant for functional genomics studies in C4 grasses. Also, this system is a potential tool for improvement of agronomic traits in C4 crop plants with complex genomes.     

Anti-inflammatory and redox-protective activities of citronellal

The anti-inflammatory and redox protective effects of the citronellal (CT) were evaluated using in vivo and in vitro tests. Intraperitoneal (i.p.) administration of CT (50, 100, and 200 mg/kg) inhibited (p < 0.05) the carrageenan-induced leukocyte migration to the peritoneal cavity. Additionally, the carrageenan- and arachidonic acid-induced rat hind paw edema was significantly inhibited (p < 0.05) by i.p. administration of 100 and 200 mg/kg of the compound. When the redox activity was evaluated, CT (200 mg/kg) significantly reduced hepatic lipoperoxidation (p < 0.001), as well as oxidation of plasmatic (p < 0.05) and hepatic (p < 0.01) proteins. The results of the present study support the hypothesis that CT possesses anti-inflammatory and redox protective activities. It is suggested that its effects are associated with the inhibition of the enzymes in the arachidonic acid pathway, which prevent cell migration by inhibiting leukotriene production, edema formation and the increase of reactive oxygen species in tissues. Therefore, CT is of potential benefit to manage inflammatory disorders and correlated damages caused by oxidant agents.     

Sugar metabolism and developmental stages of rubber tree (Hevea brasiliensis L.) seeds

Changes in the concentration of sugars and sucrose metabolism enzymes can characterize the developmental stages of a seed. In recalcitrant species such as Hevea brasiliensis L., little is known about these changes. We aimed to evaluate the three main stages of development of rubber tree seeds – histodifferentiation, cell elongation and accumulation of reserves. The activities of acid and neutral invertases (E.C. 3.2.1.26) and sucrose synthase (EC 2.4.1.13), and the concentrations of reducing sugars (RS), total soluble sugars (TSS) and sucrose (Suc) were determined concomitantly with the histochemical and anatomical evaluation of seed structure. Histodifferentiation in rubber tree seeds occurs up to 75 days after anthesis (DAA). The concentration of RS is high and of Suc is low during seed histodifferentiation, which occurs along with a visible increase in the number of cell divisions. After that period, there is an increase in the concentration of Suc (mg g^?1) and in the number and size of starch granules, and a decrease in the concentration of RS (mg g^?1). At that point, cell elongation occurs. At 135 DAA, there is an inversion in the concentration of these two sugars and an increase in reserve accumulation. Thus, in seeds of the evaluated clone, the period up to 75 DAA is characterized as the histodifferentiation stage, while from that time up to 120 DAA the cell elongation stage takes place. The final stage of seed maturation and reserve accumulation begins at 135 DAA, and the seed, including the embryo, is completely formed at 175 DAA.     

Mauriac syndrome still exists

Background/objectiveMauriac syndrome (MS) is a rare complication of type 1 diabetes mellitus (DM1). It is related to low insulin concentrations and is less common since longer-acting insulins became available. It is characterized by hepatomegaly, growth and puberty delay, and the presence of elevated transaminases and serum lipids. The aim of this study was to describe the patients from a pediatric diabetic population that fulfill the criteria of MS.Materials and methodsA retrospective analysis of the pediatric diabetic population with diagnostic criteria of MS currently followed at Hospital de Braga, was performed.ResultsFrom a population of 91 patients with DM1 18 years, 6 patients with the criteria for MS were identified: 5 girls, and 1 boy. The age at presentation was 13–17 years, with a minimum interval between DM1 diagnosis and MS criteria of 4 years. All the patients were prescribed intensive insulin therapy (median daily insulin dose: 0.88 U/kg). All had a previous history of poor glycemic control before the diagnosis of MS with glycated hemoglobin (HbA1c) between 8.8 and 12.9%. Increase of hepatic enzymes was present in all the patients; 4 of them had associated hepatomegaly. All the girls presented puberty delay and cushingoid features. None of the patients presented short stature and 5 of them presented mixed dyslipidemia.ConclusionsAlthough MS is an ancient entity described in DM1, it still exists, particularly in adolescent females. Being aware of MS is of extreme importance since most of the clinical features are reversible with better glycemic control.     

Bitrophic toxicity of Cry1Ac to Cycloneda sanguinea,a predator in Brazilian cotton

Insect predators are exposed to the Cry1Ac toxin in Bt cotton fields through several pathways. In this study, we investigated the effects of activated Cry1Ac added to a diet on Cycloneda sanguinea (L.) (Coleoptera: Coccinellidae), which is one of the main predators of non‐target pests in Brazilian cotton. Direct bitrophic exposure of C. sanguinea to Cry1Ac was done by feeding beetles with Aphis gossypii (Glover) (Hemiptera: Aphidae) sprayed with 500 μg per ml Cry1Ac solution. Larval and pupal survival, development time, aphid consumption, and adult longevity were recorded daily. Couples within the same experimental treatment were paired and numbers of eggs laid and hatched per female were recorded daily. Net replacement rate was calculated for each female. During development, a C. sanguinea larva consumed on average 1.8 μg of activated Cry1Ac. No significant differences due to Cry1Ac were observed for any of the response variables, except aphid consumption. Larvae receiving Cry1Ac consumed more aphids than larvae receiving distilled water alone. Additional statistical analyses were conducted to evaluate independence of responses, and for the independent responses, a simple meta‐analysis was conducted to test the null hypothesis that all responses were zero. Nearly all of the response variables were statistically independent. Two pairs of responses were not independent, but the associated multivariate tests were not significant. The meta‐analysis suggested that all effects were not different from random variation around zero and no cumulative effects could be detected. Our results indicated that bitrophic exposure to activated Cry1Ac is likely to have little or no adverse ecological effect on C. sanguinea.