Mitigation of Fatigue Damage in Self-Healing Vascular Materials

The fatigue response of an epoxy matrix containing vasculature for the delivery of liquid healing agents is investigated. The release of a rapidly curing, two-part epoxy healing chemistry into the wake of a propagating crack reduces the rate of crack extension by shielding the crack tip from the full range of applied stress intensity factor. Crack propagation is studied for a variety of loading conditions, with the maximum applied stress intensity factor ranging from 62 to 84% of the quasi-static fracture toughness of the material. At the highest level of applied load, the rate of mechanical damage is so fast that the healing agents do not fully mix and polymerize, and the effect of healing is minimal. The self-healing response is most effective at impeding the slower propagating cracks, with complete crack arrest occurring at the lowest level of applied load, and reductions of 79–84% in the rate of crack extension at intermediate loads.

Cognitive maturation in preterm and term born adolescents

Background: Adolescence is a critical period of brain structural reorganisation and maturation of cognitive abilities. This relatively late developmental reorganisation may be altered in individuals who were born preterm.

Methods: We carried out longitudinal neuropsychological testing in 94 very preterm individuals (VPT; before 33 weeks' gestation) and 44 term born individuals at mean ages of 15.3 years ( adolescence) and 19.5 years (young adulthood).

Results: Full scale, verbal and performance IQ and phonological verbal fluency were significantly lower in the VPT group than the term group at both ages. Repeated measures ANOVA showed only one group by time point interaction for semantic verbal fluency (F= 10.25; df = 107; p = 0.002). Paired- sample t tests showed that semantic verbal fluency increased significantly in the term group over adolescence (t = -5.10; df = 42; p < 0.001), but did not increase in the VPT group (t = 0.141; df = 69; p = 0.889). For verbal IQ, there was a significant interaction between time point and sex (F = 4.48; df = 1; p = 0.036) with paired- sample t tests showing that verbal IQ decreased in males between adolescence and adulthood (t = 3.35; df = 71; p = 0.001), but did not change significantly in females (t = 0.20; df = 52; p = 0.845).

Conclusion: Decrements of intellectual functioning in VPT individuals persist into adulthood. Additionally, there is a deficit in the adolescent maturation of semantic verbal fluency in individuals born VPT.

Effects of very low birthweight on brain structure in adulthood

Very-low-birthweight (VLBW) individuals are at high risk of brain injury in the perinatal period. We wished to determine how such early brain lesions affect brain structure in adulthood. Thirty-two VLBW adults (20 female, 12 male) and, 18 term, normal birthweight sibling control individuals (nine female, nine male) underwent structural MRI at a mean age of 23 years 4 months (range 17 to 33 years; SD 3.4). Images were analyzed using an automated tissue segmentation algorithm in order to estimate whole brain tissue class volumes in native space. Images were then warped to a template image in standard space. There was no significant between-group difference in whole brain, greymatter, white matter, or total cerebral spinal fluid (CSF) volumes. However, lateral ventricular volume was significantly increased by 41% in those with VLBW. The ratio of grey to white matter was also significantly increased (by 10%) in those with VLBW. Group comparison maps showed widespread changes in the distribution of grey and white matter, and relative excess of ventricular CSF, in the brains of VLBW individuals. Increased ventricular volume predicted decreased grey matter in subcortical nuclei and limbic cortical structures, and decreased periventricular white matter. We conclude that these diffuse abnormalities of grey and white matter are a consequence,of the interaction of perinatal brain injury and ongoing neurodevelopmental processes.

Neonatal Ultrasound Results Following Very Preterm Birth Predict Adolescent Behavioral and Cognitive Outcome

This study investigated the association between different neonatal ultrasonographic classifications and adolescent cognitive, educational, and behavioral outcomes following very preterm birth. Participants included a group of 120 adolescents who were born very preterm (33 weeks of gestation), subdivided into three groups according to their neonatal cerebral ultrasound (US) classifications: (a) normal (N = 69), (b) periventricular hemorrhage (PVH, N = 37), and (c) PVH with ventricular dilatation (PVH + DIL, N = 14), and 50 controls. The cognitive functions assessed were full-scale IQ, phonological and semantic verbal fluency, and visual-motor integration. Educational outcomes included reading and spelling; behavioral outcomes were assessed with the Rutter Parents' Scale and the Premorbid Adjustment Scale (PAS). Adolescent outcome scores were compared among the four groups. A main effect for group was observed for full-scale IQ, Rutter Parents' Scale total scores, and PAS total scores, after controlling for gestational age, socioeconomic status and gender, with the PVH + DIL group showing the most impaired scores compared to the other groups. The current results demonstrate that routine neonatal ultrasound classifications are associated with later cognitive and behavioral outcome. Neonatal ultrasounds could aid in the identification of subgroups of children who are at increased risk of neurodevelopmental problems. These at risk subgroups could then be referred to appropriate early intervention services.

Dam Methylation Participates in the Regulation of PmrA/PmrB and RcsC/RcsD/RcsB Two Component Regulatory Systems in Salmonella enterica Serovar Enteritidis

The absence of Dam in Salmonella enterica serovar Enteritidis causes a defect in lipopolysaccharide (LPS) pattern associated to a reduced expression of wzz gene. Wzz is the chain length regulator of the LPS O-antigen. Here we investigated whether Dam regulates wzz gene expression through its two known regulators, PmrA and RcsB. Thus, the expression of rcsB and pmrA was monitored by quantitative real-time RT-PCR and Western blotting using fusions with 3×FLAG tag in wild type (wt) and dam strains of S. Enteritidis. Dam regulated the expression of both rcsB and pmrA genes; nevertheless, the defect in LPS pattern was only related to a diminished expression of RcsB. Interestingly, regulation of wzz in serovar Enteritidis differed from that reported earlier for serovar Typhimurium; RcsB induces wzz expression in both serovars, whereas PmrA induces wzz in S. Typhimurium but represses it in serovar Enteritidis. Moreover, we found that in S. Enteritidis there is an interaction between both wzz regulators: RcsB stimulates the expression of pmrA and PmrA represses the expression of rcsB. Our results would be an example of differential regulation of orthologous genes expression, providing differences in phenotypic traits between closely related bacterial serovars.

Stereoselective disposition of fluoxetine and norfluoxetine during pregnancy and breast-feeding

To compare the disposition of fluoxetine and norfluoxetine enantiomers in the mother, foetus and infant.

Green tea supplementation increases glutathione and plasma antioxidant capacity in adults with the metabolic syndrome

Green tea, a popular polyphenol-containing beverage, has been shown to alleviate clinical features of the metabolic syndrome. However, its effects in endogenous antioxidant biomarkers are not clearly understood. Thus, we tested the hypothesis that green tea supplementation will upregulate antioxidant parameters (enzymatic and nonenzymatic) in adults with the metabolic syndrome. Thirty-five obese participants with the metabolic syndrome were randomly assigned to receive one of the following for 8 weeks: green tea (4 cups per day), control (4 cups water per day), or green tea extract (2 capsules and 4 cups water per day). Blood samples and dietary information were collected at baseline (0 week) and 8 weeks of the study. Circulating carotenoids (a-carotene, ß-carotene, lycopene) and tocopherols (a-tocopherol, ?-tocopherol) and trace elements were measured using high-performance liquid chromatography and inductively coupled plasma mass spectroscopy, respectively. Serum antioxidant enzymes (glutathione peroxidase, glutathione, catalase) and plasma antioxidant capacity were measured spectrophotometrically. Green tea beverage and green tea extract significantly increased plasma antioxidant capacity (1.5 to 2.3 µmol/L and 1.2 to 2.5 µmol/L, respectively; P <.05) and whole blood glutathione (1783 to 2395 µg/g hemoglobin and 1905 to 2751 µg/g hemoglobin, respectively; P <.05) vs controls at 8 weeks. No effects were noted in serum levels of carotenoids and tocopherols and glutathione peroxidase and catalase activities. Green tea extract significantly reduced plasma iron vs baseline (128 to 92 µg/dL, P <.02), whereas copper, zinc, and selenium were not affected. These results support the hypothesis that green tea may provide antioxidant protection in the metabolic syndrome.

Pomegranate polyphenols lower lipid peroxidation in adults with type 2 diabetes but have no effects in healthy volunteers:a pilot study

Aims. To examine the antioxidant and anti-inflammatory effects of pomegranate polyphenols in obese patients with type 2 diabetes (T2DM) (n = 8) and in healthy nondiabetic controls (n = 9). Methods. Participants received 2 capsules of pomegranate polyphenols (POMx, 1 capsule = 753?mg polyphenols) daily for 4 weeks. Blood draws and anthropometrics were performed at baseline and at 4 weeks of the study. Results. Pomegranate polyphenols in healthy controls and in T2DM patients did not significantly affect body weight and blood pressure, glucose and lipids. Among clinical safety profiles, serum electrolytes, renal function tests, and hematological profiles were not significantly affected by POMx supplementation. However, aspartate aminotransferase (AST) showed a significant increase in healthy controls, while alanine aminotransferase (ALT) was significantly decreased in T2DM patients at 4 weeks (P <0.05), though values remained within the normal ranges. Among the biomarkers of lipid oxidation and inflammation, oxidized LDL and serum C-reactive protein (CRP) did not differ at 4 weeks in either group, while pomegranate polyphenols significantly decreased malondialdehyde (MDA) and hydroxynonenal (HNE) only in the diabetic group versus baseline (P <0.05). Conclusions. POMx reduces lipid peroxidation in patients with T2DM, but with no effects in healthy controls, and specifically modulates liver enzymes in diabetic and nondiabetic subjects. Larger clinical trials are merited.

Low-energy cranberry juice decreases lipid oxidation and increases plasma antioxidant capacity in women with metabolic syndrome

Cranberries, high in polyphenols, have been associated with several cardiovascular health benefits, although limited clinical trials have been reported to validate these findings. We tested the hypothesis that commercially available low-energy cranberry juice (Ocean Spray Cranberries, Inc, Lakeville-Middleboro, Mass) will decrease surrogate risk factors of cardiovascular disease, such as lipid oxidation, inflammation, and dyslipidemia, in subjects with metabolic syndrome. In a randomized, double-blind, placebo-controlled trial, participants identified with metabolic syndrome (n = 15-16/group) were assigned to 1 of 2 groups: cranberry juice (480 mL/day) or placebo (480 mL/day) for 8 weeks. Anthropometrics, blood pressure measurements, dietary analyses, and fasting blood draws were conducted at screen and 8 weeks of the study. Cranberry juice significantly increased plasma antioxidant capacity (1.5 ± 0.6 to 2.2 ± 0.4 µmol/L [means ± SD], P <.05) and decreased oxidized low-density lipoprotein and malondialdehyde (120.4 ± 31.0 to 80.4 ± 34.6 U/L and 3.4 ± 1.1 to 1.7 ± 0.7 µmol/L, respectively [means ± SD], P <.05) at 8 weeks vs placebo. However, cranberry juice consumption caused no significant improvements in blood pressure, glucose and lipid profiles, C-reactive protein, and interleukin-6. No changes in these parameters were noted in the placebo group. In conclusion, low-energy cranberry juice (2 cups/day) significantly reduces lipid oxidation and increases plasma antioxidant capacity in women with metabolic syndrome.

Strawberries decrease atherosclerotic markers in subjects with metabolic syndrome

Strawberries have been reported to be potent antioxidants and reduce cardiovascular risk factors, such as elevated blood pressure, hyperglycemia, dyslipidemia, and inflammation in limited studies. We hypothesized that freeze-dried strawberry supplementation will improve blood pressure, impaired glucose, dyslipidemia, or circulating adhesion molecules in obese subjects with metabolic syndrome, thereby lowering cardiovascular risk factors in these subjects. Twenty-seven subjects with metabolic syndrome (2 males and 25 females; body mass index, 37.5 +/- 2.15 kg/m(2); age, 47.0 +/- 3.0 years [means +/- SE]) consumed 4 cups of freeze-dried strawberry beverage (50 g freeze-dried strawberries approximately 3 cups fresh strawberries) or equivalent amounts of fluids (controls, 4 cups of water) daily for 8 weeks in a randomized controlled trial. Anthropometrics and blood pressure measurements, assessment of dietary intakes, and fasting blood draws were conducted at screen and 8 weeks of the study. Strawberry supplementation significantly decreased total and low-density lipoprotein cholesterol (5.8 +/- 0.2 to 5.2 +/- 0.2 mmol/L and 3.5 +/- 0.2 to 3.1 +/- 0.1 mmol/L, respectively [means +/- SE], P <.05) and small low-density lipoprotein particles using nuclear magnetic resonance-determined lipoprotein subclass profile vs controls at 8 weeks (794.6 +/- 94.0 to 681.8 +/- 86.0 nmol/L [means +/- SE], P <.05). Strawberry supplementation further decreased circulating levels of vascular cell adhesion molecule-1 vs controls at 8 weeks (272.7 +/- 17.4 to 223.0 +/- 14.0 ng/mL [means +/- SE], P <.05). Serum glucose, triglycerides, high-density lipoprotein cholesterol, blood pressure, and waist circumference were not affected. Thus, short-term freeze-dried strawberry supplementation improved selected atherosclerotic risk factors, including dyslipidemia and circulating adhesion molecules in subjects with metabolic syndrome, and these results need confirmation in future trials.

Blueberries decrease cardiovascular risk factors in obese men and women with metabolic syndrome

Among all fruits, berries have shown substantial cardio-protective benefits due to their high polyphenol content. However, investigation of their efficacy in improving features of metabolic syndrome and related cardiovascular risk factors in obesity is limited. We examined the effects of blueberry supplementation on features of metabolic syndrome, lipid peroxidation, and inflammation in obese men and women. Forty-eight participants with metabolic syndrome [4 males and 44 females; BMI: 37.8 +/- 2.3 kg/m(2); age: 50.0 +/- 3.0 y (mean +/- SE)] consumed freeze-dried blueberry beverage (50 g freeze-dried blueberries, approximately 350 g fresh blueberries) or equivalent amounts of fluids (controls, 960 mL water) daily for 8 wk in a randomized controlled trial. Anthropometric and blood pressure measurements, assessment of dietary intakes, and fasting blood draws were conducted at screening and at wk 4 and 8 of the study. The decreases in systolic and diastolic blood pressures were greater in the blueberry-supplemented group (- 6 and - 4%, respectively) than in controls (- 1.5 and - 1.2%) (P lt 0.05), whereas the serum glucose concentration and lipid profiles were not affected. The decreases in plasma oxidized LDL and serum malondialdehyde and hydroxynonenal concentrations were greater in the blueberry group (- 28 and - 17%, respectively) than in the control group (- 9 and - 9%) (P lt 0.01). Our study shows blueberries may improve selected features of metabolic syndrome and related cardiovascular risk factors at dietary achievable doses.

Green tea minimally affects biomarkers of inflammation in obese subjects with metabolic syndrome

Green tea (Camellia sinensis) has shown to exert cardioprotective benefits in observational studies. The objective of this clinical trial was to assess the effects of green tea on features of metabolic syndrome and inflammation in obese subjects.