1,842 research outputs found

    The effect of estrogen on muscle damage biomarkers following prolonged aerobic exercise in eumenorrheic women

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    This study assessed the influence of estrogen (E 2 ) on muscle damage biomarkers [skeletal muscle - creatine kinase (CK); cardiac muscle - CK-MB] responses to prolonged aerobic exercise. Eumenorrheic women (n=10) who were physically active completed two 60-minute treadmill running sessions at ~60-65% maximal intensity during low E 2 (midfollicular menstrual phase) and high E 2 (midluteal menstrual phase) hormonal conditions. Blood samples were collected prior to exercise (following supine rest), immediately post-, 30 min post-, and 24 hours post-exercise to determine changes in muscle biomarkers. Resting blood samples confirmed appropriate E 2 hormonal levels Total CK concentrations increased following exercise and at 24 hours post-exercise were higher in the midfollicular low E 2 phase (p<0.001). However, CK-MB concentrations were unaffected by E 2 level or exercise (p=0.442) resulting in the ratio of CK-MB to total CK being consistently low in subject responses (i.e., indicative of skeletal muscle damage). Elevated E 2 levels reduce the CK responses of skeletal muscle, but had no effect on CK-MB responses following prolonged aerobic exercise. These findings support earlier work showing elevated E 2 is protective of skeletal muscle from exercise-induced damage associated with prolonged aerobic exercise

    Menstrual cycle phase effects free testosterone responses to prolonged aerobic exercise

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    Research has shown that total testosterone (tT) levels in women increase acutely during a prolonged bout of aerobic exercise. Few studies, however, have considered the impact of the menstrual cycle phase on this response or have looked at the biologically active free testosterone (fT) form responses. Therefore, this study examined the fT concentration response independently and as a percentage (fT%) of tT to prolonged aerobic exercise during phases of the menstrual cycle with low estrogen-progesterone (L-EP; i.e., follicular phase) and high estrogen-progesterone (H-EP; i.e., luteal phase). Ten healthy, recreationally trained, eumennorrheic women (X ± SD: age = 20 ± 2 y, mass = 58.7 ± 8.3 kg, body fat = 22.3 ± 4.9 %, VO2max = 50.7 ± 9.0 ml/kg/min) participated in a laboratory based study and completed a 60-minute treadmill run during the L-EP and H-EP menstrual phases at ~70% of VO2max. Blood was drawn prior to (PRE), immediately after (POST) and following 30 minutes of recovery (30POST) with each 60-minute run. During H-EP, there was a significant increase in fT concentrations from PRE to POST (p < 0.01) while in L-EP fT levels were unchanged; which resulted in fT being significantly higher at H-EP POST versus L-EP POST (p < 0.03). Area-under-the-curve (AUC) responses were calculated, for fT the total AUC was greater in H-EP than L-EP (p < 0.04). There was no significant interaction of fT% between phases and exercise sampling time. There was, however, a main effect for exercise where fT% POST was a greater proportion of tT than at PRE (p < 0.01). In summary, hormonal changes associated with the menstrual cycle impact fT response to a prolonged aerobic exercise bout; specifically, there being higher levels under H-EP conditions. This suggests more biologically active T is available during exercise in this phase. This response may be a function of the higher core temperatures found with H-EP causing greater sex hormone binding protein release of T, or could be a function of greater degrees of glandular production. Further work is warranted to elucidate the mechanism of this occurrence. It is recommended that researchers examining T responses to exercise in women look at both tT and fT forms in order to have an accurate endocrine assessment in women

    Transkingdom Networks: A Systems Biology Approach to Identify Causal Members of Host-Microbiota Interactions

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    Improvements in sequencing technologies and reduced experimental costs have resulted in a vast number of studies generating high-throughput data. Although the number of methods to analyze these "omics" data has also increased, computational complexity and lack of documentation hinder researchers from analyzing their high-throughput data to its true potential. In this chapter we detail our data-driven, transkingdom network (TransNet) analysis protocol to integrate and interrogate multi-omics data. This systems biology approach has allowed us to successfully identify important causal relationships between different taxonomic kingdoms (e.g. mammals and microbes) using diverse types of data

    Molecular diversity of anthracnose pathogen populations associated with UK strawberry production suggests multiple introductions of three different Colletotrichum species.

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    Fragaria × ananassa (common name: strawberry) is a globally cultivated hybrid species belonging to Rosaceae family. Colletotrichum acutatum sensu lato (s.l.) is considered to be the second most economically important pathogen worldwide affecting strawberries. A collection of 148 Colletotrichum spp. isolates including 67 C. acutatum s.l. isolates associated with the phytosanitary history of UK strawberry production were used to characterize multi-locus genetic variation of this pathogen in the UK, relative to additional reference isolates that represent a worldwide sampling of the diversity of the fungus. The evidence indicates that three different species C. nymphaeae, C. godetiae and C. fioriniae are associated with strawberry production in the UK, which correspond to previously designated genetic groups A2, A4 and A3, respectively. Among these species, 12 distinct haplotypes were identified suggesting multiple introductions into the country. A subset of isolates was also used to compare aggressiveness in causing disease on strawberry plants and fruits. Isolates belonging to C. nymphaeae, C. godetiae and C. fioriniae representative of the UK anthracnose pathogen populations showed variation in their aggressiveness. Among the three species, C. nymphaeae and C. fioriniae appeared to be more aggressive compared to C. godetiae. This study highlights the genetic and pathogenic heterogeneity of the C. acutatum s.l. populations introduced into the UK linked to strawberry production
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