Gender differences in the physiological responses and kinematic behaviour of elite sprint cross-country skiers

Gender differences in performance by elite endurance athletes, including runners, track cyclists and speed skaters, have been shown to be approximately 12%. The present study was designed to examine gender differences in physiological responses and kinematics associated with sprint cross-country skiing. Eight male and eight female elite sprint cross-country skiers, matched for performance, carried out a submaximal test, a test of maximal aerobic capacity (VO2max) and a shorter test of maximal treadmill speed (Vmax) during treadmill roller skiing utilizing the G3 skating technique. The men attained 17% higher speeds during both the VO2max and the Vmax tests (P < 0.05 in both cases), differences that were reduced to 9% upon normalization for fat-free body mass. Furthermore, the men exhibited 14 and 7% higher VO2max relative to total and fat-free body mass, respectively (P < 0.05 in both cases). The gross efficiency was similar for both gender groups. At the same absolute speed, men employed 11% longer cycles at lower rates, and at peak speed, 21% longer cycle lengths (P < 0.05 in all cases). The current study documents approximately 5% larger gender differences in performance and VO2max than those reported for comparable endurance sports. These differences reflect primarily the higher VO2max and lower percentage of body fat in men, since no gender differences in the ability to convert metabolic rate into work rate and speed were observed. With regards to kinematics, the gender difference in performance was explained by cycle length, not by cycle rate

Analysis of a sprint ski race and associated laboratory determinants of world-class performance

This investigation was designed to analyze the time-trial (STT) in an international cross-country skiing sprint skating competition for (1) overall STT performance and relative contributions of time spent in different sections of terrain, (2) work rate and kinematics on uphill terrain, and (3) relationships to physiological and kinematic parameters while treadmill roller ski skating. Total time and times in nine different sections of terrain by 12 world-class male sprint skiers were determined, along with work rate and kinematics for one specific uphill section. In addition, peak oxygen uptake (VO2peak), gross efficiency (GE), peak speed (Vpeak), and kinematics in skating were measured. Times on the last two uphill and two final flat sections were correlated to overall STT performance (r = ~−0.80, P < 0.001). For the selected uphill section, speed was correlated to cycle length (r = −0.75, P < 0.01) and the estimated work rate was approximately 160% of peak aerobic power. VO2peak, GE, Vpeak, and peak cycle length were all correlated to STT performance (r = ~−0.85, P < 0.001). More specifically, VO2peak and GE were correlated to the last two uphill and two final flat section times, whereas Vpeak and peak cycle length were correlated to times in all uphill, flat, and curved sections except for the initial section (r = ~−0.80, P < 0.01). Performances on uphill and flat terrain in the latter part were the most significant determinants of overall STT performance. Peak oxygen uptake, efficiency, peak speed, and peak cycle length were strongly correlated to overall STT performance, as well as to performance in different sections of the race

2019 international consensus on cardiopulmonary resuscitation and emergency cardiovascular care science with treatment recommendations : summary from the basic life support; advanced life support; pediatric life support; neonatal life support; education, implementation, and teams; and first aid task forces

The International Liaison Committee on Resuscitation has initiated a continuous review of new, peer-reviewed, published cardiopulmonary resuscitation science. This is the third annual summary of the International Liaison Committee on Resuscitation International Consensus on Cardiopulmonary Resuscitation and Emergency Cardiovascular Care Science With Treatment Recommendations. It addresses the most recent published resuscitation evidence reviewed by International Liaison Committee on Resuscitation Task Force science experts. This summary addresses the role of cardiac arrest centers and dispatcher-assisted cardiopulmonary resuscitation, the role of extracorporeal cardiopulmonary resuscitation in adults and children, vasopressors in adults, advanced airway interventions in adults and children, targeted temperature management in children after cardiac arrest, initial oxygen concentration during resuscitation of newborns, and interventions for presyncope by first aid providers. Members from 6 International Liaison Committee on Resuscitation task forces have assessed, discussed, and debated the certainty of the evidence on the basis of the Grading of Recommendations, Assessment, Development, and Evaluation criteria, and their statements include consensus treatment recommendations. Insights into the deliberations of the task forces are provided in the Justification and Evidence to Decision Framework Highlights sections. The task forces also listed priority knowledge gaps for further research

Seroprevalence and risk factors of herpes simplex virus type-2 infection among pregnant women in Northeast India

<p>Abstract</p> <p>Background</p> <p>Herpes simplex virus type-2 (HSV-2) is one of the most common sexually transmitted infections that facilitate human immunodeficiency virus (HIV) acquisition by over two fold or more. The development of HSV-2 control methods as a measure to control HIV epidemic in high HSV-2/HIV areas has become a priority. Two out of the six high HIV prevalent states of India are located in the Northeastern region of India. Due to lack of documented HSV-2 studies from this part of the country; there was a need for estimating the seroprevalence and risk factors of HSV-2 infection in this defined population.</p> <p>Methods</p> <p>Pregnant women (n = 1640) aged18 years and above attending antenatal clinics of tertiary referral hospitals in five Northeastern states of India were screened for type specific HSV-2 IgG antibodies. Blood samples were collected from all the participants after conducting interviews. Univariate and multivariate analyses were performed to identify the risk factors associated with HSV-2 seropositivity.</p> <p>Results</p> <p>Overall seroprevalence of HSV-2 infection was 8.7% (142/1640; 95% CI 7.3-10.0) with a highest prevalence of 15.0% (46/307; 95% CI 11.0-19.0) in the state of Arunachal Pradesh. Higher seroprevalence was observed with increasing age (Adj. Odds Ratio [AOR] 1.9 for 22-25 years old, AOR 2.29 for > 29 years old). The risk factors associated with HSV-2 seropositives were multiple sex partners (AOR 2.5, <it>p </it>= 0.04), condom non-user's (AOR 4.7, p <it><</it>0.001), early coitarchal age (age of first intercourse) 'less than 18 years' (AOR 9.6, <it>p = </it>0.04), middle income group (AOR 2.1, <it>p = </it>0.001) compared to low income group and low level of education (AOR 3.7, <it>p = </it>0.02) compared to higher education. HSV-2 seropositivity was higher among Christians (12.6%) compared to Muslims (3.8%). The most frequent clinical symptoms among HSV-2 seropositives were excess vaginal discharge in last one year (53.5%, 76/142) and pelvic pain (26.1%, 37/142). While among subjects with genital ulcers, HSV-2 seroprevalence was 36.8% (7/19).</p> <p>Conclusions</p> <p>Overall seroprevalence of HSV-2 infection among pregnant women of Northeast India is relatively low. The generation of awareness among high risk groups may have played key role to limit the infection. The role of vaccination against HSV-2 in near future and elimination of HSV-2 viral shedding along with genital tract inflammation in high HIV/HSV-2 areas may be an option for initiating successful intervention strategies to reduce the transmission and acquisition of HIV infection in Northeast India.</p

Studying the association between musculoskeletal disorders, quality of life and mental health. A primary care pilot study in rural Crete, Greece

<p>Abstract</p> <p>Background</p> <p>The burden of musculoskeletal disorders (MSD) on the general health and well-being of the population has been documented in various studies. The objective of this study was to explore the association between MSD and the quality of life and mental health of patients and to discuss issues concerning care seeking patterns in rural Greece.</p> <p>Methods</p> <p>Patients registered at one rural Primary Care Centre (PCC) in Crete were invited to complete the Nordic Musculoskeletal Questionnaire (NMQ) for the analysis of musculoskeletal symptoms, together with validated instruments for measuring health related quality of life (SF-36) and mental distress (GHQ-28).</p> <p>Results</p> <p>The prevalence rate of MSD was found to be 71.2%, with low back and knee pain being the most common symptoms. Most conditions significantly impaired the quality of life, especially the physical dimensions of SF-36. Depression was strongly correlated to most MSD (<it>p </it>< 0.001). Multiple logistic analyses revealed that patients who consulted the PCC due to MSD were likely to have more mental distress or impaired physical functioning compared to those who did not.</p> <p>Conclusion</p> <p>Musculoskeletal disorders were common in patients attending the rural PCC of this study and were associated with a poor quality of life and mental distress that affected their consultation behaviour.</p

Increasing Clinical Virulence in Two Decades of the Italian HIV Epidemic

The recent origin and great evolutionary potential of HIV imply that the virulence of the virus might still be changing, which could greatly affect the future of the pandemic. However, previous studies of time trends of HIV virulence have yielded conflicting results. Here we used an established methodology to assess time trends in the severity (virulence) of untreated HIV infections in a large Italian cohort. We characterized clinical virulence by the decline slope of the CD4 count (n = 1423 patients) and the viral setpoint (n = 785 patients) in untreated patients with sufficient data points. We used linear regression models to detect correlations between the date of diagnosis (ranging 1984–2006) and the virulence markers, controlling for gender, exposure category, age, and CD4 count at entry. The decline slope of the CD4 count and the viral setpoint displayed highly significant correlation with the date of diagnosis pointing in the direction of increasing virulence. A detailed analysis of riskgroups revealed that the epidemics of intravenous drug users started with an apparently less virulent virus, but experienced the strongest trend towards steeper CD4 decline among the major exposure categories. While our study did not allow us to exclude the effect of potential time trends in host factors, our findings are consistent with the hypothesis of increasing HIV virulence. Importantly, the use of an established methodology allowed for a comparison with earlier results, which confirmed that genuine differences exist in the time trends of HIV virulence between different epidemics. We thus conclude that there is not a single global trend of HIV virulence, and results obtained in one epidemic cannot be extrapolated to others. Comparison of discordant patterns between riskgroups and epidemics hints at a converging trend, which might indicate that an optimal level of virulence might exist for the virus

Intrauterine environments and breast cancer risk: meta-analysis and systematic review

INTRODUCTION: Various perinatal factors, including birth weight, birth order, maternal age, gestational age, twin status, and parental smoking, have been postulated to affect breast cancer risk in daughters by altering the hormonal environment of the developing fetal mammary glands. Despite ample biologic plausibility, epidemiologic studies to date have yielded conflicting results. We investigated the associations between perinatal factors and subsequent breast cancer risk through meta-analyses. METHODS: We reviewed breast cancer studies published from January 1966 to February 2007 that included data on birth weight, birth order, maternal age, gestational age, twin status, and maternal or paternal smoking. Meta-analyses using random effect models were employed to summarize the results. RESULTS: We found that heavier birth weights were associated with increased breast cancer risk, with studies involving five categories of birth weight identifying odds ratios (ORs) of 1.24 (95% confidence interval [CI] 1.04 to 1.48) for 4,000 g or more and 1.15 (95% CI 1.04 to 1.26) for 3,500 g to 3,999 g, relative to a birth weight of 2,500 to 2,599 g. These studies provided no support for a J-shaped relationship of birthweight to risk. Support for an association with birthweight was also derived from studies based on three birth weight categories (OR 1.15 [95% CI 1.01 to 1.31] for > or =4,000 g relative to or =3,000 g relative to <3,000 g). Women born to older mothers and twins were also at some increased risk, but the results were heterogeneous across studies and publication years. Birth order, prematurity, and maternal smoking were unrelated to breast cancer risk. CONCLUSION: Our findings provide some support for the hypothesis that in utero exposures reflective of higher endogenous hormone levels could affect risk for development of breast cancer in adulthood

Dietary fat and breast cancer risk revisited: a meta-analysis of the published literature

Animal experiments and human ecological studies suggest that dietary fat intake is associated with a risk of breast cancer, but individual-based studies have given contradictory results. We have carried out a meta-analysis of this association to include all papers published up to July 2003. Case-control and cohort studies that examined the association of dietary fat, or fat-containing foods, with risk of breast cancer were identified. A total of 45 risk estimates for total fat intake were obtained. Descriptive data from each study were extracted with an estimate of relative risk and its associated 95% confidence interval (CI), and were analysed using the random effects model of DerSimonian and Laird. The summary relative risk, comparing the highest and lowest levels of intake of total fat, was 1.13 (95% CI: 1.03-1.25). Cohort studies (N=14) had a summary relative risk of 1.11 (95% CI: 0.99-1.25) and case-control studies (N=31) had a relative risk of 1.14 (95% CI 0.99-1.32). Significant summary relative risks were also found for saturated fat (RR, 1.19; 95% CI: 1.06-1.35) and meat intake (RR, 1.17; 95% CI 1.06-1.29). Combined estimates of risk for total and saturated fat intake, and for meat intake, all indicate an association between higher intakes and an increased risk of breast cancer. Case-control and cohort studies gave similar results