bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of Carbohydrate, Caffeine, and Guarana on Cognitive Performance, Perceived Exertion, and Shooting Performance in High-Level Athletes
Authors: Pomportes Laura , Brisswalter Jeanick , Hays Arnaud , Davranche Karen 
Published: October 2018

Purpose:To investigate the effect of ingesting carbohydrate (CHO), caffeine (CAF), and a guarana complex (GUAc) during a running exercise on cognitive performance, rating of perceived exertion (RPE), and shooting performance in high-level modern pentathlon athletes.Methods:A total of 10 athletes completed 4 counterbalanced sessions within a 2-wk period, corresponding to ingestions of CHO (30 g), GUAc (300 mg), CAF (200 mg), or placebo. The exercise involved a 40-min run on a treadmill at a steady speed, previously determined as a “somewhat hard” exercise (RPE 13). Shooting and cognitive performance (Simon task) were assessed in 3 phases: before exercise and ingestion, before exercise and after half ingestion, and after exercise and full ingestion. Drinks were consumed 40 min (250 mL) and 5 min (125 mL) prior to exercise and after 20 min of running (125 mL). RPE was assessed at 10-min intervals during exercise.Results:There was an interaction between drink and exercise on mean reaction time (P = .01,) and a drink effect on RPE (P = .01,). CHO, CAF, and GUAc enhanced the speed of information processing after exercise (P = .003,P = .004, andP = .04, respectively), but only CAF and GUAc decreased RPE (P = .002 andP = .02, respectively).Conclusion:The results highlight a beneficial effect of nutritional supplements on information processing and RPE. This finding is particularly interesting as decision-making processes are crucial in the performance of many sports.
Training to Compete at Altitude:Natural Altitude or Simulated Live High:Train Low?
Authors: Carr Amelia J. , Garvican-Lewis Laura A. , Vallance Brent S. , Drake Andrew P. , Saunders Philo U. , Humberstone Clare E. , Gore Christopher J. 
Published: October 2018

Purpose: To compare the effects of natural altitude training (NAT) and simulated (SIM) live high:train low altitude training on road-race walking performance (min), as well as treadmill threshold walking speed (km·h−1) at 4 mmol·L−1 and maximal oxygen consumption, at 1380 m. Methods: Twenty-two elite-level male (n = 15) and female (n = 7) race walkers completed 14 d of NAT at 1380 m (n = 7), SIM live high:train low at 3000:600 m (n = 7), or control conditions (600-m altitude; CON, n = 8). All preintervention and postintervention testing procedures were conducted at 1380 m and consisted of an incremental treadmill test, completed prior to a 5 × 2-km road-race walking performance test. Differences between groups were analyzed via mixed-model analysis of variance and magnitude-based inferences, with a substantial change detected with >75% likelihood of exceeding the smallest worthwhile change. Results: The improvement in total performance time for the 5 × 2-km test in NAT was not substantially different from SIM but was substantially greater (85% likely) than CON. The improvement in percentage decrement in the 5 × 2-km performance test in NAT was greater than in both SIM (93% likely) and CON (93% likely). The increase in maximal oxygen consumption was substantially greater (91% likely) in NAT than in SIM. Improvement in threshold walking speed was substantially greater than CON for both SIM (91% likely) and NAT (90% likely). Conclusions: Both NAT and SIM may allow athletes to achieve reasonable acclimation prior to competition at low altitude.
Anaerobic Speed Reserve: A Key Component of Elite Male 800-m Running
Authors: Sandford Gareth N. , Allen Sian V. , Kilding Andrew E. , Ross Angus , Laursen Paul B. 
Published: October 2018

Purpose: In recent years (2011–2016), men’s 800-m championship running performances have required greater speed than previous eras (2000–2009). The “anaerobic speed reserve” (ASR) may be a key differentiator of this performance, but profiles of elite 800-m runners and their relationship to performance time have yet to be determined. Methods: The ASR—determined as the difference between maximal sprint speed (MSS) and predicted maximal aerobic speed (MAS)—of 19 elite 800- and 1500-m runners was assessed using 50-m sprint and 1500-m race performance times. Profiles of 3 athlete subgroups were examined using cluster analysis and the speed reserve ratio (SRR), defined as MSS/MAS. Results: For the same MAS, MSS and ASR showed very large negative (both r = −.74 ± .30, ±90% confidence limits; very likely) relationships with 800-m performance time. In contrast, for the same MSS, ASR and MAS had small negative relationships (both r = −.16 ± .54; possibly) with 800-m performance. ASR, 800-m personal best, and SRR best defined the 3 subgroups along a continuum of 800-m runners, with SRR values as follows: 400–800 m ≥ 1.58, 800 m ≤ 1.57 to ≥ 1.48, and 800–1500 m ≤ 1.47 to ≥ 1.36. Conclusion: MSS had the strongest relationship with 800-m performance, whereby for the same MSS, MAS and ASR showed only small relationships to differences in 800-m time. Furthermore, the findings support the coaching observation of three 800-m subgroups, with the SRR potentially representing a useful and practical tool for identifying an athlete’s 800-m profile. Future investigations should consider the SRR framework and its application for individualized training approaches in this event.
Reliability and Validity of a Novel Trunk-Strength Assessment for High-Performance Sprint Flat-Water Kayakers
Authors: Steeves Darren , Thornley Leo J. , Goreham Joshua A. , Jordan Matthew J. , Landry Scott C. , Fowles Jonathon R. 
Published: October 2018

Purpose: To determine the reliability and validity of a novel trunk maximal isometric force assessment involving 7 different tasks with 200-m times for elite sprint flat-water kayakers. Methods: Ten elite sprint flat-water kayakers performed a series of maximal isometric voluntary contractions (MVCs) on 2 separate days to assess reliability. MVC force was assessed as the participants sat on a modified kayak ergometer and applied their maximal isometric force to a uniaxial load cell during 7 different tasks. The 7 tasks of interest were a seated trunk-forward flexion, bilateral (left and right) rotational pulls, bilateral rotational pushes, and a sport-specific bilateral kayak-stroke simulation. Twenty elite flat-water kayak athletes (10 male and 10 female) participated in the validity portion by completing the series of tasks in conjunction with a 200-m race. Results: MVC force values ranged from 84 to 800 N across all participants and all tasks. The average coefficient of variation of the 7 tasks ranged from 2.4% to 7.7%. Regression analysis showed Pearson correlations ranging from −.84 to −.22 for both absolute and relative values with 200-m performance times. Conclusions: MVC force measured in each task was considered reliable as a small degree of variance between trials was found. The summation of the 7 trunk scores showed very strong correlations with on-water performance, indicating that this assessment is valid for elite sprint kayakers.
Brief Report: Training Load, Salivary Immunoglobulin A, and Illness Incidence in Elite Paratriathletes
Authors: Stephenson Ben T. , Hynes Eleanor , Leicht Christof A. , Tolfrey Keith , Goosey-Tolfrey Victoria L. 
Published: October 2018

Purpose: To gain an exploratory insight into the relation between training load (TL), salivary secretory immunoglobulin A (sIgA), and upper respiratory tract illness (URI) in elite paratriathletes. Methods: Seven paratriathletes were recruited. Athletes provided weekly saliva samples for the measurement of sIgA over 23 consecutive weeks (February to July) and a further 11 consecutive weeks (November to January). sIgA was compared to individuals’ weekly training duration, external TL, and internal TL, using time spent in predetermined heart-rate zones. Correlations were assessed via regression analyses. URI was quantified via weekly self-report symptom questionnaire. Results: There was a significant negative relation between athletes’ individual weekly training duration and sIgA secretion rate (P = .028), with changes in training duration accounting for 12.7% of the variance (quartiles: 0.2%, 19.2%). There was, however, no significant relation between external or internal TL and sIgA parameters (P ≥ .104). There was no significant difference in sIgA when URI was present or not (101% vs 118% healthy median concentration; P ≥ .225); likewise, there was no difference in sIgA when URI occurred within 2 wk of sampling or not (83% vs 125% healthy median concentration; P ≥ .120). Conclusions: Paratriathletes’ weekly training duration significantly affects sIgA secretion rate, yet the authors did not find a relation between external or internal TL and sIgA parameters. Furthermore, it was not possible to detect any link between sIgA and URI occurrence, which throws into question the potential of using sIgA as a monitoring tool for early detection of illness.
Clinical Breathing Mechanics Differ Based on Test and Position
Authors: Horris Hannah , Anderson Barton E. , Bay R. Curtis , Huxel Bliven Kellie C. 
Published: October 2018

Context:Altered diaphragm function is linked to decreased core stabilization, postural changes, and decreased function. Two clinical tests used to assess breathing are the Hi-lo and lateral rib expansion (LRE) tests. It is currently unknown how breathing classification based on these tests differ and how their results are affected by varying test positions.Objective:To compare the results of breathing tests when conducted in varying test positions.Design:Prospective cross-sectional study.Setting:University laboratory.Participants:A total of 50 healthy adults (females 31 and males 29; age 29.3 [4.1] y; height 170.0 [10.4] cm; weight70.7 [15.1] kg).Intervention(s):Hi-lo and LRE tests in supine, seated, standing, and half-kneeling body positions. All tests were recorded and later scored by a single examiner. A generalized estimating equations approach with breathing test and body position as factors was used for analysis. Pairwise comparison with Bonferroni correction was used to adjust for multiple tests. Statistical significance was set atP = .05, 2 tailed.Main Outcome Measures:Hi-lo and LRE tests were scored based on the presence or absence of abdominal excursion, LRE, and superior rib cage migration. Following scoring, results were classified as functional or dysfunctional based on observation of these criteria.Results:A significant breathing test × test position interaction (P < .01) was noted, as well as main effects for test (P < .01) and test position (P < .01). All Hi-lo test positions identified significantly more dysfunctional breathers in positions of increased stability demand (P < .01), except between standing and half-kneeling positions (P = .52). In the LRE test, all positions were similar (P > .99) except for half-kneeling, which was significantly different from all other positions (P < .01).Conclusions:The Hi-lo test and LRE tests assess different breathing mechanics. Clinicians should use these tests in combination to gain a comprehensive understanding of a person’s breathing pattern. The Hi-lo test should be administered in multiple testing positions.
Females Decrease Vertical Ground Reaction Forces Following 4-Week Jump-Landing Feedback Intervention Without Negative Affect on Vertical Jump Performance
Authors: Ericksen Hayley M. , Lefevre Caitlin , Luc-Harkey Brittney A. , Thomas Abbey C. , Gribble Phillip A. , Pietrosimone Brian 
Published: October 2018

Context: High vertical ground reaction force (vGRF) when initiating ground contact during jump landing is one biomechanical factor that may increase risk of anterior cruciate ligament injury. Intervention programs have been developed to decrease vGRF to reduce injury risk, yet generating high forces is still critical for performing dynamic activities such as a vertical jump task. Objective: To evaluate if a jump-landing feedback intervention, cueing a decrease in vGRF, would impair vertical jump performance in a separate task (Vertmax). Design: Randomized controlled trial. Patients (or Other Participants): Forty-eight recreationally active females (feedback: n = 31; 19.63 [1.54] y, 1.6 [0.08] cm, 58.13 [7.84] kg and control: n = 15; 19.6 [1.68] y, 1.64 [0.05] cm, 60.11 [8.36] kg) participated in this study. Intervention: Peak vGRF during a jump landing and Vertmax were recorded at baseline and 4 weeks post. The feedback group participated in 12 sessions over the 4-week period consisting of feedback provided for 6 sets of 6 jumps off a 30-cm box. The control group was instructed to return to the lab 28 days following the baseline measurements. Main Outcome Measures: Change scores (postbaseline) were calculated for peak vGRF and Vertmax. Group differences were evaluated for peak vGRF and Vertmax using a Mann–Whitney U test (P < .05). Results: There were no significant differences between groups at baseline (P > .05). The feedback group (−0.5 [0.3] N/kg) demonstrated a greater decrease in vGRF compared with the control group (0.01 [0.3] N/kg) (t(46) = −5.52, P < .001). There were no significant differences in change in Vertmax between groups (feedback = 0.9 [2.2] cm, control = 0.06 [2.1] cm; t(46) = 0.46, P = .64). Conclusions: While the feedback intervention was effective in decreasing vGRF when landing from a jump, these participants did not demonstrate changes in vertical jump performance when assessed during a different task. Practitioners should consider implementing feedback intervention programs to reduce peak vGRF, without worry of diminished vertical jump performance.
A Novel Extended-Spectrum TEM-Type β-Lactamase (TEM-52) Associated with Decreased Susceptibility to Moxalactam in
Klebsiella pneumoniae
Authors: Poyart Claire , Mugnier Pierre , Quesne Gilles , Berche Patrick , Trieu-Cuot Patrick 
Published: October 2018

ABSTRACT

Klebsiella pneumoniae
NEM865 was isolated from the culture of a stool sample from a patient previously treated with ceftazidime (CAZ). Analysis of this strain by the disk diffusion test revealed synergies between amoxicillin-clavulanate (AMX-CA) and CAZ, AMX-CA and cefotaxime (CTX), AMX-CA and aztreonam (ATM), and more surprisingly, AMX-CA and moxalactam (MOX). Clavulanic acid (CA) decreased the MICs of CAZ, CTX, and MOX, which suggested that NEM865 produced a novel extended-spectrum β-lactamase. Genetic, restriction endonuclease, and Southern blot analyses revealed that the resistance phenotype was due to the presence in NEM865 of a 13.5-kb mobilizable plasmid, designated pNEC865, harboring a Tn
3
-like element. Sequence analysis revealed that the
blaT
gene of pNEC865 differed from
bla
TEM-1
by three mutations leading to the following amino acid substitutions: Glu
104
→Lys, Met
182
→Thr, and Gly
238
→Ser (Ambler numbering). The association of these three mutations has thus far never been described, and the
blaT
gene carried by pNEC865 was therefore designated
bla
TEM-52
. The enzymatic parameters of TEM-52 and TEM-3 were found to be very similar except for those for MOX, for which the affinity of TEM-52 (

K
i

, 0.16 μM) was 10-fold higher than that of TEM-3 (

K
i

, 1.9 μM). Allelic replacement analysis revealed that the combination of Lys
104
, Thr
182
, and Ser
238
was responsible for the increase in the MICs of MOX for the TEM-52 producers.
KY-62, a Polyene Analog of Amphotericin B, for Treatment of Murine Candidiasis
Authors: Graybill John R. , Najvar Laura K. , Fothergill Annette , Hardin Thomas , Rinaldi Michael , Lambros Chris , Regen Steven L. 
Published: October 2018

ABSTRACT

KY-62 is a water-soluble analog of amphotericin B. In vitro testing of five clinical isolates of
Candida albicans
showed KY-62 to have potency similar to that of amphotericin B. KY-62 was administered to mice infected intravenously with
C. albicans
. In vivo, KY-62 was effective in immunocompetent mice, with potency similar to that of amphotericin B. KY-62 was well tolerated up to 30 mg/kg of body weight per dose, an amount that would be lethal with amphotericin B. KY-62 was less effective in mice rendered neutropenic with 5-fluorouracil. The addition of flucytosine had little effect. KY-62 may have potential for clinical development.
Kenyan
Plasmodium falciparum
Field Isolates: Correlation between Pyrimethamine and Chlorcycloguanil Activity In Vitro and Point Mutations in the Dihydrofolate Reductase Domain
Authors: Nzila-Mounda A. , Mberu E. K. , Sibley C. H. , Plowe C. V. , Winstanley P. A. , Watkins W. M. 
Published: October 2018

ABSTRACT

Sixty-nine Kenyan
Plasmodium falciparum
field isolates were tested in vitro against pyrimethamine (PM), chlorcycloguanil (CCG), sulfadoxine (SD), and dapsone (DDS), and their dihydrofolate reductase (DHFR) genotypes were determined. The in vitro data show that CCG is more potent than PM and that DDS is more potent than SD. DHFR genotype is correlated with PM and CCG drug response. Isolates can be classified into three distinct groups based on their 50% inhibitory concentrations (IC
50
s) for PM and CCG (
P
< 0.01) and their DHFR genotypes. The first group consists of wild-type isolates with mean PM and CCG IC
50
s of 3.71 ± 6.94 and 0.24 ± 0.21 nM, respectively. The second group includes parasites which all have mutations at codon 108 alone or also at codons 51 or 59 and represents one homogeneous group for which 25- and 6-fold increases in PM and CCG IC
50
s, respectively, are observed. Parasites with mutations at codons 108, 51, and 59 (triple mutants) form a third distinct group for which nine- and eightfold increases in IC
50
s, respectively, of PM and CCG compared to the second group are observed. Surprisingly, there is a significant decrease (
P
< 0.01) of SD and DDS susceptibility in these triple mutants. Our data show that more than 92% of Kenyan field isolates have undergone at least one point mutation associated with a decrease in PM activity. These findings are of great concern because they may indicate imminent PM-SD failure, and there is no affordable antimalarial drug to replace PM-SD (Fansidar).
In Vitro and In Vivo Inhibition of Murine Gamma Herpesvirus 68 Replication by Selected Antiviral Agents
Authors: Neyts Johan , De Clercq Erik 
Published: October 2018

ABSTRACT

We have evaluated the susceptibility of the murine gamma herpesvirus 68 (MHV-68) to a variety of antiviral agents. The acyclic nucleoside phosphonate analogs cidofovir [(
S
)-1-(3-hydroxy-2-phosphonylmethoxypropyl)cytosine], (
S
)-1-(3-hydroxy-2-phosphonylmethoxypropyl)adenine (HPMPA), and adefovir [9-(2-phosphonylmethoxyethyl)adenine] efficiently inhibited the replication of the virus in Vero cells (50% effective concentrations [EC
50
s], 0.008, 0.06, and 2.2 μg/ml, respectively). Acyclovir, ganciclovir, and brivudin [(
E
)-5-(2-bromovinyl)-2′-deoxyuridine] had equipotent activities (EC
50
s, 1.5 to 8 μg/ml), whereas foscarnet and penciclovir were less effective (EC
50
s, 23 and ≥30 μg/ml, respectively). The novel N-7-substituted nucleoside analog S2242 [7-(1,3-dihydroxy-2-propoxymethyl)purine] inhibited MHV-68 replication by 50% at 0.2 μg/ml. The susceptibilities of MHV-68 and Epstein-Barr virus (EBV) to cidofovir, HPMPA, adefovir, and acyclovir were found to be comparable. However, for penciclovir, ganciclovir, brivudin, and S2242, major differences in the sensitivity of MHV-68 and EBV were observed, suggesting that MHV-68 is not always an optimal surrogate for the study of antiviral strategies for EBV. When evaluated with a model for lethal MHV-68 infections in mice with severe combined immunodeficiency, cidofovir proved to be very efficient in protecting against virus-induced mortality (100% survival at 50 days postinfection), whereas acyclovir, brivudin, and adefovir had little or no effect.
In Vitro Activity of Sanfetrinem and Affinity for the Penicillin-Binding Proteins of
Streptococcus pneumoniae
Authors: Sifaoui Farid , Varon Emmanuelle , Kitzis Marie-Dominique , Gutmann Laurent 
Published: October 2018

ABSTRACT
Against penicillin-susceptible pneumococci, the activity of sanfetrinem was similar to those of penicillin, amoxicillin, cefotaxime, imipenem, and meropenem, while against penicillin-resistant strains, sanfetrinem and the carbapenems exhibited superior activity (MICs at which 90% of strains are inhibited, ≤1 μg/ml). PBP 1a in the penicillin-susceptible strain and PBP 1a and PBP 2b in the more resistant isolates seemed to be the essential penicillin-binding proteins for imipenem and sanfetrinem.
Sequences of Homologous β-Lactamases from Clinical Isolates of
Serratia marcescens
with Different Substrate Specificities
Authors: Matsumura Naoki , Minami Shinzaburo , Mitsuhashi Susumu 
Published: October 2018

ABSTRACT

Genes for two group 1 β-lactamases, SRT-1 and SST-1, were sequenced. These β-lactamases were produced by clinical isolates of
Serratia marcescens
, isolates GN16694 and GN19450, respectively. The resulting enzymes were 96% identical. SRT-1 hydrolyzed oxyimino cephalosporins, but SST-1 hardly hydrolyzed them. At residue 213 in the third motif, which is conserved among group 1 β-lactamases, SRT-1 and SST-1 had Lys and Glu, respectively. By site-directed mutagenesis, the substitution of Glu by Lys at residue 213 in SST-1 resulted in an enzyme that hydrolyzed oxyimino cephalosporins.
Microbiologic Efficacy of Azithromycin and Susceptibilities to Azithromycin of Isolates of
Chlamydia pneumoniae
from Adults and Children with Community-Acquired Pneumonia
Authors: Roblin Patricia M. , Hammerschlag Margaret R. 
Published: October 2018

ABSTRACT

Chlamydia pneumoniae
was eradicated from the nasopharynges of 26 of 33 (78.8%) evaluable children and adults with community-acquired pneumonia who were treated with azithromycin. We tested 55 isolates of
C. pneumoniae
obtained from 46 of these patients against azithromycin. The MIC at which 90% of the isolates were inhibited and the minimal chlamydiacidal concentration at which 90% of strains tested were killed of azithromycin for these isolates were both 0.5 μg/ml. Seven patients remained culture positive after treatment. The MICs of azithromycin for isolates from two patients increased fourfold after therapy. However, all the patients with persistent infection improved clinically. Further studies of treatment of
C. pneumoniae
infection, utilizing culture, are needed both to assess efficacy and to monitor for the possible development of antibiotic resistance.