Effect of an intense period of competition on race performance and self-reported illness in elite cross-country skiers.

The aim of this study was to determine whether participating in a cross-country skiing stage race (Tour de Ski; TDS) affects subsequent illness incidence, training, and race performance. Self-reported training and illness data from 44 male and female elite cross-country skiers were included. In total, 127 years of data were collected (2-3 seasons per athlete). Illness incidence, training load, and performance in international competitions were calculated for athletes who did and did not participate in TDS. Forty-eight percent of athletes reported becoming ill during or in the days immediately after taking part in TDS vs 16% of athletes who did not participate. In both groups, illness incidence was somewhat lower for female athletes. For male athletes, race performance was significantly worse for 6 weeks following TDS vs 6 weeks before TDS. Furthermore, while female athletes who participated in TDS performed relatively better than controls in Olympics/World Championships, male athletes who participated in TDS typically performed worse in subsequent major championships. Participating in TDS appears to result in ∼ 3-fold increase in risk of illness in this period. Male athletes appear more prone to illness and also see a drop in race performance following TDS, possibly linked to differences in training load before and after the event.

Comparative activity of twelve beta-lactam drugs tested against penicillin-resistant Streptococcus pneumoniae from five medical centers: effects of serum protein and capsular material on potency and spectrum as measured by reference tests.

A total of 152 strains of Streptococcus pneumoniae from diverse geographic areas in the United States and with different levels of penicillin resistance were tested against five broad-spectrum cephalosporins, ampicillin, piperacillin, ticarcillin, and three beta-lactamase inhibitor combinations. Also, the effect of human serum proteins on the activity of selected "third-generation" cephalosporins was examined. The overall rank order of activity among the cephalosporins against penicillin-susceptible strains was: ceftriaxone (MIC90, 0.03 microgram/mL) > cefotaxime > ceftizoxime = cefuroxime > ceftazidime (MIC90, 0.5 microgram/mL). Only cefotaxime and ceftriaxone exhibited significant activity against penicillin-intermediate or -resistant isolates. Ampicillin, piperacillin, and penicillin were generally eight- to 16-fold more potent than ticarcillin and no increase in the effectiveness of these agents was observed with the addition of the beta-lactamase inhibitors (clavulanate, sulbactam, tazobactam). Ceftriaxone potency was significantly decreased (> or = four-fold) by the modest addition of 25% pooled human serum proteins and this change modified the rank order of potency against nonpenicillin-susceptible pneumococci to favor cefotaxime (41% resistant versus 71% for ceftriaxone; MICs at > or = 2 micrograms/mL). Induced high-level capsular production had no measurable effect on the MIC results of tested agents. These results confirm the continued activity advantages of cefotaxime and ceftriaxone against various populations of pneumococci compared to other alternative beta-lactams. The predictive value, however, of the utilized breakpoint concentrations of the cephalosporins, remains in question for pneumococcal infections other than those in the central nervous system and at unaltered, "usual" dosing.