Alteration of immune function in women collegiate soccer players and college students

The purpose of this study was to monitor the stress-induced alteration in concentrations of salivary immunoglobulin (S-IgA) and cortisol and the incidence of upper respiratory tract infections (URTI) over the course of a 9-week competitive season in college student-athletes and college students. The subjects consisted of 14 NCAA Division III collegiate female soccer athletes (19.8 ± 1.0 years, mean ± SD) and 14 female college students (22.5 ± 2.6 years). Salivary samples were collected for 9 weeks during a competitive soccer season. S-IgA and cortisol concentrations were determined by enzyme linked immunosorbent assay (ELISA). A training and performance questionnaire was given to the subjects every week, to record the subjects’ session rating of perceived exertion (RPE) for all the training, load, monotony and strain, as well as any injuries or illnesses experienced. The between groups ANOVA procedure for repeated measures showed no changes in salivary concentrations of IgA and cortisol. Chisquare analysis showed that during the 9-week training season injury and illness occurred at a higher rate among the soccer players. There was a significant difference at baseline between soccer and control SIgA levels (p ≤ 0.05). Decreased levels of SIgA and increases in the indices of training (load, strain and monotony) were associated with an increase in the incidence of illness during the 9-week competitive soccer season

The influence of training load, exposure to match play and sleep duration on daily wellbeing measures in youth athletes

This study assessed the influence of training load, exposure to match play and sleep duration on two daily wellbeing measures in youth athletes. Forty-eight youth athletes (age 17.3 ± 0.5 years) completed a daily wellbeing questionnaire (DWB), the Perceived Recovery Status scale (PRS), and provided details on the previous day’s training loads (TL) and self-reported sleep duration (sleep) every day for 13 weeks (n = 2727). Linear mixed models assessed the effect of TL, exposure to match play and sleep on DWB and PRS. An increase in TL had a most likely small effect on muscle soreness (d = −0.43;± 0.10) and PRS (d = −0.37;± 0.09). Match play had a likely small additive effect on muscle soreness (d = −0.26;± 0.09) and PRS (d = −0.25;± 0.08). An increase in sleep had a most likely moderate effect on sleep quality (d = 0.80;± 0.14); a most likely small effect on DWB (d = 0.45;± 0.09) and fatigue (d = 0.42;± 0.11); and a likely small effect on PRS (d = 0.25;± 0.09). All other effects were trivial or did not reach the pre-determined threshold for practical significance. The influence of sleep on multiple DWB subscales and the PRS suggests that practitioners should consider the recovery of an athlete alongside the training stress imposed when considering deviations in wellbeing measures

Dipeptidyl peptidase IV in angiotensin-converting enzyme inhibitor-associated angioedema

Angioedema is a potentially life-threatening adverse effect of angiotensin-converting enzyme inhibitors. Bradykinin and substance P, substrates of angiotensin-converting enzyme, increase vascular permeability and cause tissue edema in animals. Studies indicate that amino-terminal degradation of these peptides, by aminopeptidase P and dipeptidyl peptidase IV, may be impaired in individuals with angiotensin-converting enzyme inhibitor-associated angioedema. This case-control study tested the hypothesis that dipeptidyl peptidase IV activity and antigen are decreased in sera of patients with a history of angiotensin-converting enzyme inhibitor-associated angioedema. Fifty subjects with a history of angiotensin-converting enzyme inhibitor-associated angioedema and 176 angiotensin-converting enzyme inhibitor-exposed control subjects were ascertained. Sera were assayed for angiotensin-converting enzyme activity, aminopeptidase P activity, aminopeptidase N activity, dipeptidyl peptidase IV activity, and antigen and the ex vivo degradation half-lives of bradykinin, des-Arg-bradykinin, and substance P in a subset. The prevalence of smoking was increased and of diabetes decreased in case versus control subjects. Overall, dipeptidyl peptidase IV activity (26.6±7.8 versus 29.6±7.3 nmol/mL per minute; P=0.026) and antigen (465.8±260.8 versus 563.1±208.6 ng/mL; P=0.017) were decreased in sera from individuals with angiotensin-converting enzyme inhibitor-associated angioedema compared with angiotensin-converting enzyme inhibitor-exposed control subjects without angioedema. Dipeptidyl peptidase IV activity (21.5±4.9 versus 29.8±6.7 nmol/mL per minute; P=0.001) and antigen (354.4±124.7 versus 559.8±163.2 ng/mL; P=0.003) were decreased in sera from cases collected during angiotensin-converting enzyme inhibition but not in the absence of angiotensin-converting enzyme inhibition. The degradation half-life of substance P correlated inversely with dipeptidyl peptidase IV antigen during angiotensin-converting enzyme inhibition. Environmental or genetic factors that reduce dipeptidyl peptidase IV activity may predispose individuals to angioedema. © 2008 American Heart Association, Inc.http://deepblue.lib.umich.edu/bitstream/2027.42/192635/2/Dipeptidyl peptidase IV in angiotensin-converting enzyme inhibitor associated angioedema.pdfPublished versio

Practical and Economical Implementation of Online H/D Exchange in LC-MS

Structural elucidation is an integral part of drug discovery and development. In recent years, due to acceleration of the drug discovery and development process, there is a significant need for highly efficient methodologies for structural elucidation. In this work, we devised and standardized a simple and economical online hydrogen–deuterium exchange methodology, which can be used for structure elucidation purposes.Deuterium oxide (D₂O) was infused as a postcolumn addition using the syringe pump at the time of elution of the analyte. The obtained hydrogen/deuterium (H/D) exchange spectrum of the unknown analyte was compared with the nonexchanged spectrum, and the extent of deuterium incorporation was delineated by using an algorithm to deconvolute partial H/D exchange, which confirmed the number of labile hydrogen(s) in the analyte. The procedure was standardized by optimizing flow rates of LC output, D₂O infusion, sheath gas, and auxiliary gas using the model compound sulfasalazine. The robustness of the methodology was demonstrated by performing sensitivity analysis of various parameters such as concentrations of analyte, effect of matrices, concentrations of aqueous mobile phase, and types of LC modifiers. The optimized technique was also applied to chemically diverse analytes and tested on various mass spectrometers. Moreover, utility of the technique was demonstrated in the areas of impurity profiling and metabolite identification, taking pravastatin-lactone and N-oxide desloratidine, as examples

Respiratory inflammation and infections in high‐performance athletes

Upper respiratory illness is the most common reason for non-injury-related presentation to a sports medicine clinic, accounting for 35-65% of illness presentations. Recurrent or persistent respiratory illness can have a negative impact on health and performance of athletes undertaking high levels of strenuous exercise. The cause of upper respiratory symptoms (URS) in athletes can be uncertain but the majority of cases are related to common respiratory viruses, viral reactivation, allergic responses to aeroallergens and exercise-related trauma to the integrity of respiratory epithelial membranes. Bacterial respiratory infections are uncommon in athletes. Undiagnosed or inappropriately treated asthma and/or allergy are common findings in clinical assessments of elite athletes experiencing recurrent URS. High-performance athletes with recurrent episodes of URS should undergo a thorough clinical assessment to exclude underlying treatable conditions of respiratory inflammation. Identifying athletes at risk of recurrent URS is important in order to prescribe preventative clinical, training and lifestyle strategies. Monitoring secretion rates and falling concentrations of salivary IgA can identify athletes at risk of URS. Therapeutic interventions are limited by the uncertainty of the underlying cause of inflammation. Topical anti-inflammatory sprays can be beneficial for some athletes. Dietary supplementation with bovine colostrum, probiotics and selected antioxidants can reduce the incidence or severity of URS in some athletes. Preliminary studies on athletes prone to URS indicate a genetic predisposition to a pro-inflammatory response and a dysregulated anti-inflammatory cytokine response to intense exercise as a possible mechanism of respiratory inflammation. This review focuses on respiratory infections and inflammation in elite/professional athletes