Electrostatic and non-electrostatic contributions to the binding free energies of anthracycline antibiotics to DNA

The knowledge about molecular factors driving simple ligand-DNA interactions is still limited. The aim of the present study was to investigate the electrostatic and non-electrostatic contributions to the binding free energies of anthracycline compounds with DNA. Theoretical calculations based on continuum methods (Poisson-Boltzmann and solvent accessible surface area) were performed to estimate the binding free energies of five selected anthracycline ligands (daunomycin, adriamycin, 9-deoxyadriamycin, hydroxyrubicin, and adriamycinone) to DNA. The free energy calculations also took into account the conformational change that DNA undergoes upon ligand binding. This conformational change appeared to be very important for estimating absolute free energies of binding. Our studies revealed that the absolute values of all computed contributions to the binding free energy were quite large compared to the total free energy of binding. However, the sum of these large positive and negative values produced a small negative value of the free energy around -10 kcal/mol. This value is in good agreement with experimental data. Experimental values for relative binding free energies were also reproduced for charged ligands by our calculations. Together, it was found that the driving force for ligand-DNA complex formation is the non-polar interaction between the ligand and DNA even if the ligand is positively charged.     

Genomic merit for reproductive traits. I: Estrous characteristics and fertility in Holstein heifers

Genetic selection of dairy cattle in the United States has included reproductive traits (daughter pregnancy rate, DPR; heifer conception rate, HCR), which is believed to have partly contributed to halting the decline in reproductive performance. The objectives of the current study were to evaluate the association among genomic merit for DPR (GDPR) and HCR (GHCR) with estrous characteristics measured by an automated device. Holstein heifers (n = 1,005) were genotyped at 2 mo of age and were classified into quartiles (Q1 = lowest, Q4 = highest) according to the GDPR and GHCR values of the study population. At 10 to 11 mo of age, heifers were fitted with a collar that recorded activity and rumination and determined the occurrence of estrus according to changes in activity and rumination compared with the individual's baseline values. Estrous characteristics of spontaneous estruses (SPE) and PGF_2α-synchronized estruses (PGSE) were recorded. Heifers had their estrous cycle synchronized with PGF_2α and following detection of estrus received either artificial insemination or embryo transfer according to the herd's genetic selection program. Heifers in Q2 (17.7 ± 0.3 h) of GHCR tended to have longer SPE than heifers in Q4 (16.7 ± 0.3 h). The interaction between GDPR and GHCR was associated with the likelihood of activity peak (0 = no estrus, 100 = maximum activity) ≥80 at SPE because, among heifers in Q3 and Q4 of GHCR, those in Q1 of GDPR were less likely to have an activity peak ≥80. Heifers in Q1 and Q2 of GDPR had reduced hazard of estrus within 7 d of the first PGF_2α treatment compared with heifers in Q4 of GDPR. Heifers in Q1 (16.1 ± 0.4 h) of GDPR had shorter PGSE than heifers in Q2 (17.6 ± 0.4 h) and Q4 (17.4 ± 0.4 h) and tended to have shorter PGSE than heifers in Q3 (17.4 ± 0.4 h). Rumination nadir on the day of PGSE was greater for heifers in Q1 (?30.1 ± 0.9 min/d) of GDPR compared with heifers in Q4 (?33.7 ± 0.9 min/d). Among heifers receiving only artificial insemination, those in Q1 of GHCR (adjusted hazard ratio = 0.65; 95% confidence interval = 0.48–0.88) became pregnant at a slower rate than heifers in Q4. Genomic merit for HCR was negatively associated with SPE but tended to be positively associated with hazard of pregnancy, whereas GDPR was positively associated with PGSE and hazard of estrus. Selection of dairy cattle for DPR and HCR may improve reproductive performance through different pathways, namely estrous characteristics and pregnancy establishment.     

Expansion of core–shell PS/PMMA particles

Structured micrometric polystyrene/poly(methyl methacrylate) particles were obtained by suspension polymerization and their expansion behavior was investigated using n‐pentane as blowing agent. The expanded particles presented two distinct microstructures with an outer region (PMMA‐rich shell) composed by cells of about 10 µm while the center of the particle (PS‐rich core) had much larger cells (50–100 μm). The core–shell particles did not expand at 100°C meaning that the PMMA shell hindered the expansion of the particles. Maximum expansion was dependent on the PMMA concentration and also on the heating temperature and the increase in the PMMA molar mass led to a delay in the onset of the process. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 4521–4527, 2013     

Phytochemical Polyphenol Extraction and Elemental Composition of Vitis labrusca L. Grape Juices Through Optimization of Pectinolytic Activity

Grape juice is a natural source of polyphenols with potential health benefits. The aim of this study was to assess the optimized basis of the pectinolytic activity through a multivariate design for the bioactive enrichment of polyphenols in grape juices and to evaluate the effect of pectinases on the extraction of minerals by ICP-MS and FAAS. Grape juices were treated with pectinases Everzym® Color and Rapidase® Smart at different conditions of enzyme concentration (0.16–1.84 g L^?1), temperature (14.8–83.6?ºC), and incubation time (9.6–110.5 min), and the effect on total phenolics, anthocyanin content, and antioxidant activity of juices were determined by employing a second-order central composite design in combination with response surface methodology. The different conditions showed significant variations in polyphenol levels of grape juices. For both of the enzymes, the increase of temperature and enzyme concentration led to a higher extraction of polyphenols, with a significant effect. Estimated effects depict a good correlation among dependent variables. For Rapidase, the optimized extraction of polyphenols was determined at an enzyme concentration of 1.57 g L^?1 and at a temperature of 54.8?ºC. For Everzym, higher concentrations of polyphenols were obtained at the enzyme concentration of 1.30 g L^?1 at 46.8?ºC. The extraction using the Rapidase enzyme significantly increased the levels of Na, K, Mg, and Fe in grape juices (p?<?0.05). The pectinolytic activity increased the polyphenol and mineral concentrations in grape juices. In addition, the optimal conditions of the pectinolytic treatment comprise a feasible alternative to improve the bioactive potential of grape juices.     

Antimicrobial activity of microencapsulated lemongrass essential oil and the effect of experimental parameters on microcapsules size and morphology

Lemongrass (Cymbopogom citratus) essential oil, known due to its broad-spectrum antimicrobial activity, was microencapsulated by simple coacervation. Poly(vinyl alcohol) (PVA, 78,000 Da and 88 mol% degree of hydrolysis) crosslinked with glutaraldehyde was used as wall-forming polymer. The influence of stirring rate and oil volume fraction on the microcapsule size distribution were evaluated. Sodium dodecil sulphate (SDS) and Poly(vinyl pirrolidone) were tested in order to avoid microcapsules agglomeration during the process. Depending on the experimental conditions, microcapsules in the range of 10 μm to 250 μm were obtained. Microcapsules presenting no agglomeration were obtained when SDS at 0.03 wt.% was used. The composition and the antimicrobial properties of the encapsulated oil were determined, demonstrating that the process of microencapsulation did not deteriorate the encapsulated essential oil.     

Genomic merit for reproductive traits. II: Physiological responses of Holstein heifers

Fertility traits were recently added to the evaluation of genetic merit, allowing for the selection of Holstein cattle with improved reproductive performance. In the current study, we investigated the associations among genomic merit for daughter pregnancy rate (GDPR) and heifer conception rate (GHCR) and physiological responses during proestrus and diestrus. Holstein heifers (n = 99) were classified based on GDPR [high = 3.26 ± 0.76 (1.6 to 5.3), n = 48; low = ?0.17 ± 0.75 (?1.8 to 1.0), n = 51] and GHCR [high = 2.75 ± 0.77 (1.5 to 5.5), n = 49; low = 0.06 ± 0.67 (?2.1 to 1.2), n = 50]. Heifers were fitted with an automated estrous detection device, were treated with PGF_2α for synchronization of estrus, and received either artificial insemination or embryo transfer at detected estrus. Blood was sampled at the time of PGF_2α treatment, within 24 h of the onset of estrus (d 0), and on d 7, 14, 19 ± 2, 28, and 35. Blood samples from all heifers were analyzed for concentrations of estradiol (d 0) and progesterone (on the day of PGF_2α treatment and d 0, 7, and 14). Blood samples from heifers pregnant on d 38 ± 3 were analyzed for concentrations of progesterone (d 0, 7, 14, 19 ± 2, 28, and 35), pregnancy-specific protein B (d 19 ± 2, 28, and 35), and insulin-like growth factor 1 (d 0, 7, 14, 19 ± 2, 28, and 35). Expression of mRNA for interferon-stimulated gene 15 in peripheral leukocytes isolated from blood collected on d 19 ± 2 was determined. Ovaries were scanned by ultrasound daily from d 0 to 4 or until ovulation was detected. Heifers with low GHCR tended to be less likely to be detected in estrus (78.0 vs. 91.8%). Estradiol concentration on d 0 was greater for heifers with high GDPR (4.53 ± 0.23 vs. 3.79 ± 0.23 pg/mL). The ovulatory follicle was larger for heifers with high GDPR (16.28 ± 0.33 vs. 14.55 ± 0.35 mm), whereas heifers with high GHCR tended to have smaller ovulatory follicles (15.00 ± 0.31 vs. 15.83 ± 0.37 mm). Heifers with high GDPR tended to be more likely to ovulate within 96 h of the onset of estrus (90.7 vs. 75.0%). Among heifers pregnant on d 38 ± 3, GDPR and GHCR were not associated with mRNA expression for interferon-stimulated gene 15. Heifers with high GDPR had greater concentration of pregnancy-specific protein B from d 28 to 35 (3.03 ± 0.15 vs. 2.48 ± 0.1 ng/mL). Heifers with high GHCR tended to have greater insulin-like growth factor 1 concentration from d 7 to 35 (108.0 ± 3.2 vs. 97.7 ± 4.2 ng/mL). Our results suggest that selection for Holstein cattle for GDPR may have positive effects on reproductive performance through changes in ovarian follicle development and steroidogenesis. Although selection of Holstein cattle for GHCR may negatively affect estrous expression by affecting ovarian follicle growth, selection for GHCR may improve reproductive performance by altering the somatotropic axis.     

Textural,Color, Hygroscopic,Lipid Oxidation,and Sensory Properties of Cookies Containing Free and Microencapsulated Chia Oil

Encapsulation of chia oil might protect omega-3 and omega-6 from lipid oxidation when producing baked foods. However, the actual gain in stability given by chia oil must be determined. In this work, chia oil or chia oil-loaded microparticles were added to a cookie formulation in order to evaluate the ability of the microcapsules in protecting chia oil from deterioration. Texture, color, water sorption isotherms, and sensorial properties were also evaluated. A hot homogenization technique was used with carnauba wax as an encapsulant, and the freeze-dried microparticles were incorporated into the cookie dough. Principal component analyses were carried out to evaluate lipid oxidation using the medium infrared spectra of the lipid fraction extracted from the baked cookies. It was found that the microencapsulated chia oil was better protected from oxidative deterioration during baking compared to the sample containing non-encapsulated chia oil. Textural analysis showed that chia oil (free and microencapsulated) acted as a coating on the wheat flour particles. Control cookies (no chia oil loaded) presented a more hydrophilic character. In the case of oil-loaded samples (free and microencapsulated), the isosteric heat of sorption behavior indicated an initial swelling step of the food polymers, resulting in the exposure of sorption sites of higher binding energies not previously available, and that this is because of the wheat particles being covered by the chia oil and the solid lipid microparticles. Furthermore, food acceptability did not change when the oil-loaded microparticles were added to the cookie formulation.