40 research outputs found
Reaction of Brassica species to Sclerotinia sclerotiorum applying inoculation techniques under controlled conditions
Oilseed rape is economically affected by stem rot caused by Sclerotinia sclerotiorum worldwide. Glucosinolates are the specific secondary metabolites of Brassica plants that appear in different profiles of each species. Their hydrolysis products have biocidal activity and may play a role in resistance against plant pathogenic fungi. The resistance of oilseed rape (Brassica napus) cultivars and two other Brassica species (B. nigra and Sinapis alba) was evaluated employing leaf disc inoculation, and oxalic acid and fungal inoculums on leaves of intact plants under controlled conditions. By using leaf disc inoculation, three plant ages were used to compare their reactions against the pathogen. No significant differences between genotypes were observed in this method. However, results demonstrated significant differences in main effects of wounding and plant age. The two intact plant inoculation techniques (oxalic acid and fungal mycelium) resulted in significant differences between genotypes in reaction to the disease. Furthermore, the oxalic acid assay followed the same pattern as fungal inoculations. Among the oilseed rape cultivars, AV-Sapphire and AG-Castle were the most resistant and susceptible genotypes, respectively. Brassica species differed significantly in their reaction to disease, in both wounded and non-wounded leaves with fungal mycelium inoculation and oxalic acid. Overall, non-significant differences between Brassica genotypes showed the unreliability of the leaf disc assay, whereas leaf inoculation of intact plants by means of either oxalic acid or fungal mycelium demonstrated significant differences in lesion size among Brassica cultivars and species
Extracellular alpha/beta-hydrolase from Paenibacillus species shares structural and functional homology to tobacco salicylic acid binding protein 2
An alpha/ beta hydrolase annotated as a putative salicylate esterase within the genome of a species of Paenibacillus previously identified from differential and selective growth on Kraft lignin was structurally and functionally characterised. Feruloyl esterases are key to the degradation of lignin in several bacterial species and although this activity was investigated, no such activity was observed. The crystal structure of the Paenibacillus esterase, here denoted as PnbE, was determined at 1.32 Å resolution, showing high similarity to Nicotiana tabacum salicylic acid binding protein 2 from the protein database. Structural similarities between these two structures across the core domains and key catalytic residues were observed, with superposition of catalytic residues giving an RMSD of 0.5 Å across equivalent Cα atoms. Conversely, the cap domains of PnbE and Nicotiana tabacum SABP2 showed greater divergence with decreased flexibility in the PnbE cap structure. Activity of PnbE as a putative methyl salicylate esterase was supported with binding studies showing affinity for salicylic acid and functional studies showing methyl salicylate esterase activity. We hypothesise that this activity could enrich Paenibacillus sp. within the rhizosphere by increasing salicylic acid concentrations within the soil
Simvastatin effects on androgens, inflammatory mediators, and endogenous pituitary gonadotropins among patients with PCOS undergoing IVF: results from a prospective, randomized, placebo-controlled clinical trial
OBJECTIVE:
To evaluate effects of simvastatin on selected biochemical parameters and reproductive outcome among patients with polycystic ovary syndrome (PCOS) who undergo in vitro fertilization (IVF).
METHODS:
Patients with PCOS were randomized to receive either oral simvastatin, 20 mg/d (n = 32), or placebo (n = 32) in a prospective, double-blind, randomized clinical trial (NCT 005-75601) in parallel with controlled ovarian hyperstimulation for IVF. All patients were determined to be at average risk for cardiovascular disease, based on high-sensitivity C-reactive protein (hsCRP) measurement at entry. After an 8-week treatment interval concluding at periovulatory human chorionic gonadotropin administration, selected clinical and laboratory parameters were measured.
RESULTS:
Mean serum total testosterone level decreased by 25% in the simvastatin group, compared to a 10% reduction in the placebo group (P 0.05). Neither fasting insulin nor quantitative insulin sensitivity check index were significantly impacted by simvastatin (P > 0.05). As expected, total cholesterol was not modified among placebo patients but was significantly reduced after simvastatin (P = 0.001). In addition, hsCRP and vascular cell adhesion protein-1 were both significantly lower after simvastatin therapy compared to controls (P ≤ 0.005 for both). At study completion, no important change in body mass index was observed in either group (P ≥ 0.60). Although oocyte maturation, fertilization, and clinical pregnancy rates were all higher after simvastatin, none of these improvements were statistically significant.
CONCLUSIONS:
This report presents data from the first prospective, randomized, placebo-controlled clinical investigation of simvastatin in the setting of PCOS and IVF. Simvastatin seems to be compatible with gonadotropin therapy for IVF and can offer beneficial endocrine and cardiovascular effects for patients with PCOS who undergo embryo transfer. Although the observed improvements in reproductive function were mild, the reductions in hsCRP and vascular cell adhesion protein-1 after simvastatin treatment were significant, suggesting the need for further clinical trials to clarify simvastatin's impact on reproductive physiology
Periplasmic expression of Pseudomonas fluorescens peroxidase Dyp1B and site-directed mutant Dyp1B enzymes enhances polymeric lignin degradation activity in Pseudomonas putida KT2440
Expression of lignin-oxidising Pseudomonas fluorescens Dyp1B in the periplasm of Pseudomonas putida KT2440, using a tat fusion construct, was found to lead to enhanced whole cell activity for oxidation of DCP and polymeric lignin substrates. Four amino acid residues predicted to lie at the manganese ion binding site of Pseudomonas fluorescens peroxidase Dyp1B were investigated using site-directed mutagenesis. Mutants H127R and S223A showed 2-fold and 4-fold higher kcat for Mn(II) oxidation respectively, and mutant S223A showed 2-fold enhanced production of low molecular weight phenolic products from a polymeric soda lignin. The mutant Pfl Dyp1B genes were expressed as tat fusions to investigate their effect on lignin oxidation by P. putida KT2440
Association between 25-hydroxyvitamin D levels and the carotid intima-media thickness
Background: There are insufficient data on the association between the serum level of vitamin D and the carotid intima-media thickness (CIMT). The aim of this study was to investigate the association between the level of serum 25-hydroxyvitamin D and the CIMT. Methods: This cross-sectional study recruited 341 patients. The level of 25-hydroxyvitamin D was measured with radioimmunoassay, and the CIMT was measured with color Doppler ultrasound. Results: The mean serum level of 25-hydroxyvitamin D was 14.88±14.63 ng/mL in the patients with a significant carotid artery involvement and 17.02±13.56 ng/mL in those without a carotid involvement, with the difference between the 2 groups constituting statistical significance (P=0.034). The prevalence rate of vitamin D deficiency in those with and without a carotid involvement was 88.6 and 74.4; the rate was significantly higher in the former group (P=0.039). Conclusions: Our study confirmed recent suggestions regarding the association between vitamin D deficiency and the progress of atherosclerosis in carotid arteries as CIMT. © 2019, Iranian Heart Association. All rights reserved