Marathon (United States)

PURPOSE: The aim of this study was to determine the distribution of running-related injuries (RRI) and medical conditions (RRMC) among runners in a popular recreational marathon. METHODS: We studied 24,817 runners (11,233 females, 13,584 males) who participated in the 2019 Marine Corps Marathon. The runners were followed for the occurrence of a RRI or RRMC. A RRI or RRMC was defined as any musculoskeletal or medical condition complaint that occurred as a result of participation in the marathon race and required the attention of a medical tent health care provider at an aid station. RRI and RRMC distributions were calculated for body location and injury/condition type. Chi-square analyses and incidence risk ratios (IRR) were used to compare these injury/condition distributions by sex. RESULTS: Overall, 236 RRIs were reported with a significantly higher incidence sustained by females (1.1%) than males (0.8%)(IRR = 1.46, 95%CI: 1.1-1.9; p = 0.002). The most common body locations affected were the foot (0.4%), knee (0.1%), ankle (0.1%) and iliotibial band (0.09%), with females having a significantly greater incidence of foot ([0.5% vs 0.3%] p = 0.04) and hip ([0.1% vs 0.02%] p = 0.01) RRIs. Blisters (0.3%), tendonitis (0.27%) and muscle strains (0.1%) were the most common RRI types; with a significantly higher occurrence of blisters among females than males ([0.4% vs 0.2%] p = 0.02). Similar distributions of fractures were found among females (0.01%) and males (0.02%). Overall, 461 RRMCs were reported with a significantly higher occurrence among males (2.1%) than females (1.5%)(IRR = 1.14, 95%CI: 1.1-1.2; p = 0.001). The most common RRMCs were muscle cramps (0.9%), dizziness (0.7%), nausea/vomiting (0.2%), and fatigue/weakness (0.09%); with males having a significantly greater incidence of muscle cramps ([1.1% vs 0.6%] p = 0.0003) and heat stroke/exhaustion ([0.07% vs 0.02%] p = 0.05). Asthmatic/breathing problems were more common among females than males ([0.1% vs 0.02%] p = 0.005). CONCLUSIONS: Our findings suggest that the occurrence of RRIs and RRMCs in the marathon were low. Participants were most likely to incur a foot RRI (especially females) or experience muscle cramps (particularly males). While the occurrence of heat-related RRMC was very low, they were more common among male runners.

Opioid analgesics are effective pain therapeutics but cause various adverse effects and addiction. For safer pain therapy, biased opioid agonists selectively target distinct m opioid receptor (MOR) conformations, while the potential of biased opioid antagonists has been neglected. Agonists convert a dormant receptor form (MOR-m) to a ligand-free active form (MOR-m*), which mediates MOR signaling. Moreover, MOR-m converts spontaneously to MOR-m* (basal signaling). Persistent upregulation of MOR-m* has been invoked as a hallmark of opioid dependence. Contrasting interactions with both MOR-m and MOR-m* can account for distinct pharmacological characteristics of inverse agonists (naltrexone), neutral antagonists (6b-naltrexol), and mixed opioid agonist-antagonists (buprenorphine). Upon binding to MOR-m*, naltrexone but not 6b-naltrexol suppresses MOR-m*signaling. Naltrexone blocks opioid analgesia non-competitively at MOR-m*with high potency, whereas 6BN must compete with agonists at MOR-m, accounting for ~100-fold lower in vivo potency. Buprenorphine’s bell-shaped dose-response curve may also result from opposing effects on MOR-m and MOR-m*. In contrast, we find that 6b-naltrexol potently prevents dependence, below doses affecting analgesia or causing withdrawal, possibly binding to MOR conformations relevant to opioid dependence. We propose that 6b-naltrexol is a biased opioid antagonist modulating opioid dependence at low doses, opening novel avenues for opioid pain therapy and use management.

ABSTRACTNewborns exposed to prenatal opioids often experience intense postnatal withdrawal after cessation of the opioid, called neonatal opioid withdrawal syndrome (NOWS), with limited pre- and postnatal therapeutic options available. In a prior study in pregnant mice we demonstrated that the peripherally selective neutral opioid antagonist, 6β-naltrexol (6BN), is a promising drug candidate for preventive prenatal treatment of NOWS. Here, we have developed methadone (MTD) treated pregnant guinea pigs as a physiologically more suitable model, enabling detection of robust spontaneous neonatal withdrawal. Prenatal MTD significantly aggravates two classic maternal separation stress behaviors in newborn guinea pigs: calling (vocalizing) and searching (locomotion) - natural attachment behaviors thought to be controlled by the endogenous opioid system. In addition, prenatal MTD significantly increases the levels of plasma cortisol in newborns, showing that cessation of MTD at birth engages the hypothalamic-pituitary-adrenal (HPA) axis. We find that co-administration of 6BN with MTD prevents these withdrawal symptoms in newborn pups with extreme potency (ID50 ∼0.02 mg/kg), at doses unlikely to induce maternal or fetal withdrawal or to interfere with opioid antinociception based on many prior studies. Furthermore, we demonstrate a similarly high potency of 6BN in preventing opioid withdrawal in adult guinea pigs (ID50 = 0.01 mg/kg). This suggests a novel receptor mechanism to account for the selectively high potency of 6BN to suppress opioid dependence as compared to its low potency as a classical opioid antagonist. In conclusion, 6BN is an attractive compound for development of a preventive therapy for NOWS.

On ten top-level Kenyan marathon runners (KA) plus nine European controls (EC, equivalent to KA), we measured maximal oxygen consumption (VO2max) and the energy cost of running (Cr) on track during training camps at moderate altitude, to better understand the KA dominance in the marathon. At each incremental running speed, steady-state oxygen consumption (VO2) was measured by telemetric metabolic cart, and lactate by electro-enzymatic method. The speed requiring VO2 = VO2max provided the maximal aerobic velocity (νmax). The energy cost of running was calculated by dividing net VO2 by the corresponding speed. The speed at lactate threshold (ν(ΘAN)) was computed from individual Lâ(b) versus speed curves. The sustainable VO2max fraction (Fd) at ν(ΘAN) (F(ΘAN)) was computed dividing nu(ΘAN) by νmax. The Fd for the marathon (Fmar) was determined as Fmar = 0.92 F(ΘAN). Overall, VO2max (64.9 ± 5.8 vs. 63.9 ± 3.7 ml kg(-1) min(-1)), νmax (5.55 ± 0.30 vs. 5.41 ± 0.29 m s(-1)) and Cr (3.64 ± 0.28 vs. 3.63 ± 0.31 J kg(-1) m(-1)) resulted the same in KA as in EC. In both groups, Cr increased linearly with the square of speed. F(ΘAN) was 0.896 ± 0.054 in KA and 0.909 ± 0.068 in EC; Fmar was 0.825 ± 0.050 in KA and 0.836 ± 0.062 in EC (NS). Accounting for altitude, running speed predictions from present data are close to actual running performances, if F(ΘAN) instead of Fmar is taken as index of Fd. In conclusion, both KA and EC did not have a very high VO2max, but had extremely high Fd, and low Cr, equal between them. The dominance of KA over EC cannot be explained on energetic grounds.

Abstract To assist oil and gas companies with reporting on non-financial performance, IPIECA and API published the Oil & Gas Industry Guidance on Voluntary Sustainability Reporting in 2005 as a framework for improving the quality and consistency of voluntary sustainability reporting. As societal and stakeholder concerns about energy security, climate change and related issues persist, sustainability reporting in the oil and gas sector continues to play a pivotal role in the way individual companies engage with a broad range of stakeholders on their activities and plans. The Guidance is currently undergoing a major revision to update the framework, refine indicator protocols, and introduce new indicators where needed. A major change incorporated into this revision process is engagement with an expert stakeholder panel to obtain external insight, direction and assistance in improving the Guidance. As a result, the revision involves a substantial re-write of the opening sections of the document to provide greater clarity on key steps in the reporting process, including discussion of strategic priorities for sustainability; value of management systems to help deliver on the business strategy; use of materiality in reporting; the importance of providing context around indicator performance data; and the role of stakeholder engagement in the reporting process. Over the course of the revision process, key objectives have been to deliver guidance that is clear, credible, and consistent with existing reporting guidance. The revised Guidance is on schedule for publication in mid-2010. This paper provides a synopsis of the direction of the revision and the anticipated end product.

A survey of container-breeding mosquitoes was conducted on urban islands (Big Coppitt Key, Rockland Key, Key West, and Stock Island) and rural islands (Big Pine Key, Cudjoe Key, Little Torch Key, No Name Key, Ramrod Key, Saddlebunch Keys, Sugarloaf Key, and Summerland Key) within the Florida Keys. Five mosquito species were collected: Aedes aegypti, Culex nigripalpus, Cx. quinquefasciatus, Cx. salinarius, and Ochlerotatus taeniorhynchus. Plastic buckets, trash cans, and discarded plastic containers most commonly were found to be mosquito breeding sites. Many containers were used by more than 1 mosquito species. More containers holding water were found in the rural areas than in the urban areas. The percentage of wet containers with mosquitoes did not differ between the rural and urban areas.

An analytical method was developed to quantitatively determine the asphaltene content in petroleum crude oils by Fourier transform infrared spectroscopy (FT-IR). Asphaltenes are a solubility class of compounds found in crude oils. They are black to dark brown solids defined by their insolubility in n-alkane solvents. The structure of asphaltene molecules is polynuclear aromatic rings with alkyl side chains and heteroatoms such as nitrogen, oxygen, and sulfur attached. Asphaltenes are known to cause oil well plugging and irreversible catalyst deactivation in refineries. The asphaltene content of 50 crude oils from a wide array of geochemical conditions was determined by the standard n-pentane insolubles method. FT-IR spectra of the 50 crude oils were collected using an attenuated total reflectance cell. A partial least squares model was generated to predict the amount of asphaltenes from 42 of the crude oils. The model was shown to have an R2 value of 0.95 and a standard error of estimate of 0.92 wt %. An independent prediction set of eight crude oils was used to test the validity of the model. The prediction set was shown to have an R2 value of 0.96 and a standard error of prediction of 0.99 wt %. The FT-IR method compares favorably with the current laboratory method in terms of results, is faster, and uses no solvents.

With the boom in jogging, the character of marathon and other long distance races has changed dramatically. A few years ago there were a few races for experienced club athletes who had usually had many years of athletics behind them and did not expect much in the way of facilities let alone medical support. In the past few years the number of races has increased almost logarithmically, reaching a total in 1983 in Great Britain of 136 full marathons (26 miles 385 yards, 42-2 km) with an average field of 1000 runners, but with fields as high as 20 000 in the London Marathon and even more for the Great North Run (half marathon).