Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 16 de 16
Filter
1.
Neuropsychologia ; : 108909, 2024 May 17.
Article in English | MEDLINE | ID: mdl-38762068

ABSTRACT

Current research suggests that menstruating female athletes might be at greater risk of musculoskeletal injury in relation to hormonal changes throughout the menstrual cycle. A separate body of work suggests that spatial cognition might also fluctuate in a similar manner. Changes in spatial cognition could, in theory, be a contributing risk factor for injury, especially in fast-paced sports that require precise, millisecond accuracy in interactions with moving objects in the environment. However, existing theories surrounding causes for increased injury risk in menstruating females largely focus on biomechanical mechanisms, with little consideration of possible cognitive determinants of injury risk. Therefore, the aim of this proof-of-principle study was to explore whether menstruating females exhibit fluctuations in cognitive processes throughout their cycle on a novel sport-oriented cognitive test battery, designed to measure some of the mental processes putatively involved in these sporting situations. A total of 394 participants completed an online cognitive battery, a mood scale and a symptom questionnaire twice, 14 days apart. After exclusions, 248 eligible participants were included in the analyses (mean: 28 ± 6 years) (male = 96, female(menstruating) = 105, female(contraception) = 47). Cycle phase for menstruating females was based on self-reported information. The cognitive battery was designed to measure reaction times, attention, visuospatial functions (including 3D mental rotation) and timing anticipation. Three composite scores were generated using factor analysis with varimax rotation (Errors, Reaction Time, Intra-Individual Variability). Mixed model ANOVAs and repeated measures ANOVAs were performed to test for between and within-subject effects. There was no group difference in reaction times and accuracy between males and females (using contraception and not). However, within subject analyses revealed that regularly menstruating females performed better during menstruation compared to being in any other phase, with faster reaction times (10ms c.ca, p < 0.01), fewer errors (p < 0.05) and lower dispersion intra-individual variability (p < 0.05). In contrast they exhibited slower reaction times (10ms c.ca, p < 0.01) and poorer timing anticipation (p < 0.01) in the luteal phase, and more errors in the predicted ovulatory phase (p < 0.01). Self-reported mood, cognitive and physical symptoms were all worst during menstruation (p < 0.01), and a significant proportion of females felt that their symptoms were negatively affecting their cognitive performance during menstruation on testing day, which was incongruent with their actual performance. These findings suggest that visuospatial and anticipatory processes may fluctuate throughout the menstrual cycle in the general population, with better performance during the menstrual phase and poorer performance during the luteal phase. If these extend to associations between phase-specific cognitive performance and injury incidence, they would support a cognitive theory of determinants of injury risk in cycling female athletes, opening an opportunity to develop mitigation strategies where appropriate.

2.
Sci Rep ; 8(1): 8374, 2018 05 30.
Article in English | MEDLINE | ID: mdl-29849032

ABSTRACT

Alternative management strategies for localised prostate cancer are required to reduce morbidity and overtreatment. The aim of this study was to evaluate the feasibility, safety and acceptability of exercise training (ET) with behavioural support as a primary therapy for low/intermediate risk localised prostate cancer. Men with low/intermediate-risk prostate cancer were randomised to 12 months of ET or usual care with physical activity advice (UCwA) in a multi-site open label RCT. Feasibility included acceptability, recruitment, retention, adherence, adverse events and disease progression. Secondary outcomes included quality of life and cardiovascular health indices. Of the 50 men randomised to ET (n = 25) or UCwA (n = 25), 92% (n = 46) completed 12 month assessments. Three men progressed to invasive therapy (two in UCwA). In the ET group, men completed mean: 140 mins per week for 12 months (95% CI 129,152 mins) (94% of target dose) at 75% Hrmax. Men in the ET group demonstrated improved body mass (mean reduction: 2.0 kg; 95% CI -2.9,-1.1), reduced systolic (mean: 13 mmHg; 95%CI 7,19) and diastolic blood pressure (mean:8 mmHg; 95% CI 5,12) and improved quality of life (EQ.5D mean:13 points; 95% CI 7,18). There were no serious adverse events. ET in men with low/intermediate risk prostate cancer is feasible and acceptable with a low progression rate to radical treatment. Early signals on clinically relevant markers were found which warrant further investigation.


Subject(s)
Exercise , Prostatic Neoplasms/therapy , Aged , Feasibility Studies , Humans , Male , Motivation , Patient Compliance , Prostatic Neoplasms/pathology , Prostatic Neoplasms/psychology , Risk , Treatment Outcome
3.
Br Dent J ; 217(10): 587-90, 2014 Nov.
Article in English | MEDLINE | ID: mdl-25415018

ABSTRACT

While the research base is limited, studies have consistently reported poor oral health in elite athletes since the first report from the 1968 Olympic Games. The finding is consistent both across selected samples attending dental clinics at major competitions and more representative sampling of teams and has led to calls from the International Olympic Committee for more accurate data on oral health. Poor oral health is an important issue directly as it can cause pain, negative effects on appearance and psychosocial effects on confidence and quality of life and may have long-term consequences for treatment burden. Self-reported evidence also suggests an impact on training and performance of athletes. There are many potential challenges to the oral health of athletes including nutritional, oral dehydration, exercise-induced immune suppression, lack of awareness, negative health behaviours and lack of prioritisation. However, in theory, oral diseases are preventable by simple interventions with good evidence of efficacy. The consensus statement aims to raise awareness of the issues of oral health in elite sport and recommends strategies for prevention and health promotion in addition to future research strategies.


Subject(s)
Athletic Performance , Oral Health , Athletes , Health Behavior , Health Promotion , Humans , Nutritional Physiological Phenomena , Oral Health/standards , Oral Hygiene
4.
J Hand Surg Eur Vol ; 39(3): 242-8, 2014 Mar.
Article in English | MEDLINE | ID: mdl-23649012

ABSTRACT

Isolated instability of the index and middle finger carpometacarpal joints is uncommon. An unpublished injury pattern in a consecutive series of 13 elite boxers is described, with mid-term radiological and functional results of two novel surgical treatments. All the boxers (from Australia and the UK) were unable to compete owing to pain and weakness. Four boxers were managed initially by open reduction and temporary K-wire fixation. Nine boxers underwent primary carpometacarpal arthrodesis. All were able to return to their previous level of competition. One boxer who had undergone a soft tissue reconstruction competed at international level but required an arthrodesis because of recurrent symptoms. In elite boxers, simple reduction and wiring may be appropriate for an acute injury causing index or middle finger carpometacarpal joint instability, however, arthrodesis is the treatment of choice when instability and degenerative changes are present.


Subject(s)
Arthrodesis/methods , Boxing/injuries , Carpometacarpal Joints/surgery , Hand Injuries/surgery , Joint Instability/surgery , Adult , Athletic Injuries/surgery , Carpometacarpal Joints/injuries , Hand Injuries/etiology , Humans , Joint Instability/etiology , Male
6.
Br J Sports Med ; 43(13): 1045-8, 2009 Dec.
Article in English | MEDLINE | ID: mdl-19858110

ABSTRACT

OBJECTIVE: Devise and implement evidence-based guidelines for the prevention and management of travellers' diarrhoea (TD), and establish the incidence of TD during an elite sporting trip to India. DESIGN: Literature review and audit. SETTING: Youth Commonwealth Games in India 2008. PARTICIPANTS: All members of the Team England Squad. MAIN OUTCOME MEASURES: Hygiene guidelines included only drinking bottled water, eating hot food and regular hand washing with alcohol gel. Ciprofloxacin was offered to non-athlete team members as prophylaxis but not to athletes due to its possible association with tendon disease. Following implementation of these guidelines, the incidence of travellers' diarrhoea (TD) in the whole squad was 24/122 (20%), compared with 7/14 (50%) on the reconnaissance trip (preguidelines). In those taking prophylactic ciprofloxacin, the incidence was 4/33 (12%), compared with 20/89 (23%) in those not taking ciprofloxacin. No athlete missed their event due to TD. CONCLUSIONS: The incidence of TD was less during the event than on the reconnaissance trip. The relative contribution to this reduction in strict hygiene guidelines as compared with potentially improved catering hygiene arrangements is unknown. Prophylactic ciprofloxacin also reduced the incidence of TD but it is probably not appropriate for use in elite athletes. Rifaximin may be an alternative for this group.


Subject(s)
Athletes , Diarrhea/prevention & control , Adolescent , Anti-Infective Agents/therapeutic use , Ciprofloxacin/therapeutic use , Clinical Protocols , Diarrhea/epidemiology , Diarrhea/ethnology , England/ethnology , Health Promotion/standards , Humans , Hygiene/standards , Incidence , India/epidemiology , Medical Audit , Travel
7.
Br J Sports Med ; 42(3): 207-11, 2008 Mar.
Article in English | MEDLINE | ID: mdl-17717062

ABSTRACT

AIMS: This study sought to confirm the efficacy of using resting 12-lead ECG alongside personal symptom and family history questionnaires and physical examination when screening for diseases with the potential to cause sudden cardiac death in the young. METHODS AND RESULTS: 1074 national and international junior athletes (mean age 15.8 (SD 0.7) years, range 10 to 27) and 1646 physically active schoolchildren (16.1 (SD 2.1) years, range 14 to 20) were screened using personal and family history questionnaires, physical examination and resting 12-lead ECG. Nine participants with a positive diagnosis of a disease associated with sudden cardiac death were identified. None of the participants diagnosed with a disease associated with sudden cardiac death were symptomatic or had a family history of note. CONCLUSION: Family history and personal symptom questionnaires alone are inadequate to identify people with diseases associated with sudden cardiac death. Use of the 12-lead ECG is essential when screening for cardiac pathology in the young.


Subject(s)
Death, Sudden, Cardiac/prevention & control , Electrocardiography/standards , Mass Screening/instrumentation , Adolescent , Adult , Child , Death, Sudden, Cardiac/etiology , Female , Heart Diseases/diagnosis , Humans , Male , Mass Screening/methods , Mass Screening/standards , Medical History Taking , Pedigree , Physical Examination , Surveys and Questionnaires
9.
Article in English | MEDLINE | ID: mdl-16034603

ABSTRACT

To determine whether perching dragonflies visually assess the distance to potential prey items, we presented artificial prey, glass beads suspended from fine wires, to perching dragonflies in the field. We videotaped the responses of freely foraging dragonflies (Libellula luctuosa and Sympetrum vicinum-Odonata, suborder Anisoptera) to beads ranging from 0.5 mm to 8 mm in diameter, recording whether or not the dragonflies took off after the beads, and if so, at what distance. Our results indicated that dragonflies were highly selective for bead size. Furthermore, the smaller Sympetrum preferred beads of smaller size and the larger Libellula preferred larger beads. Each species rejected beads as large or larger than their heads, even when the beads subtended the same visual angles as the smaller, attractive beads. Since bead size cannot be determined without reference to distance, we conclude that dragonflies are able to estimate the distance to potential prey items. The range over which they estimate distance is about 1 m for the larger Libellula and 70 cm for the smaller Sympetrum. The mechanism of distance estimation is unknown, but it probably includes both stereopsis and the motion parallax produced by head movements.


Subject(s)
Distance Perception/physiology , Insecta/physiology , Predatory Behavior/physiology , Size Perception/physiology , Animals , Behavior, Animal , Flight, Animal/physiology , Videotape Recording/methods
10.
J Health Organ Manag ; 19(1): 16-31, 2005.
Article in English | MEDLINE | ID: mdl-15938600

ABSTRACT

PURPOSE: Seeks to explore the brokerage role of facilities manager in hospitals, based on the premise that facilities management (FM) is largely concerned with "strategic brokerage". Strategic brokerage is the term coined by Akhaghi to explain the integration of a wide range of support services to ensure the effective operation of the core business of an organization. DESIGN/METHODOLOGY/APPROACH: The research was conducted in the health service sector using a single case study approach to examine the brokerage potential for FM in a hospital in the Sydney Metropolitan area. A social network analysis technique was used to identify and analyse the communication networks of players in a hospital environment. Two general questions guided the analysis. First, what is the brokerage potential within the FM process? Second, where are the opportunities for brokerage? FINDINGS: The results indicate that identifying relationship linkages between different functional units can create potential brokerage opportunities. ORIGINALITY/VALUE: The proposition is made that viewing FM from a brokerage perspective can add value to the delivery of health-care services.


Subject(s)
Entrepreneurship , Hospital Administration , Hospital Administrators , Interdepartmental Relations , Interprofessional Relations , Negotiating , Organizational Innovation , Cooperative Behavior , Decision Making, Organizational , Health Services Research , Hospital Bed Capacity, 500 and over , Humans , Maintenance and Engineering, Hospital/organization & administration , Materials Management, Hospital/organization & administration , New South Wales , Organizational Case Studies , Professional Role
11.
J Biol Chem ; 256(16): 8705-12, 1981 Aug 25.
Article in English | MEDLINE | ID: mdl-7263679

ABSTRACT

Allylisopropylacetamide is shown to be a suicide substrate for the phenobarbital-inducible cytochromes P-450. In phenobarbital-induced rat liver microsomes about 70% of the cytochrome P-450-mediated N,N-dimethylaniline N-demethylase activity is sensitive to allylisopropylacetamide inactivation; the residual 30% of the N-demethylase activity is incapable of allylisopropylacetamide turnover and insensitive to allylisopropylacetamide inactivation. The partition number for inactivation of the susceptible population of cytochrome P-450 indicates turnover of 201 molecules of allylisopropylacetamide per molecule of P-450 inactivated. A purified phenobarbital-induced isozyme of cytochrome P-450, when reconstituted with purified rat liver cytochrome P-450 reductase, is also inactivated by allylisopropylacetamide in a suicide fashion with a corrected partition ratio of 184 turnovers of allylisopropylacetamide per inactivation event. This partition number is corrected for the competing O2-dependent autoinactivation of cytochrome P-450 which we have previously shown to occur with the purified isozyme (Loosemore, M., Light, D. R., and W#alsh, C. (1980) J. Biol. Chem. 255, 9017-9020). The 201 product molecules of cytochrome P-450-mediated turnover of allylisopropylacetamide in either the microsomal or purified enzyme system are probably the epoxide, are reactive toward alkylation of cellular nucleophiles, and covalently modify protein and exogenous calf thymus DNA molecules.


Subject(s)
Acetamides/pharmacology , Allylisopropylacetamide/pharmacology , Cytochrome P-450 Enzyme System/biosynthesis , Microsomes, Liver/enzymology , Phenobarbital/metabolism , Animals , DNA/metabolism , Enzyme Induction/drug effects , Isoenzymes/biosynthesis , Kinetics , Microsomes, Liver/drug effects , Rats
12.
J Biol Chem ; 255(19): 9017-20, 1980 Oct 10.
Article in English | MEDLINE | ID: mdl-6773957

ABSTRACT

NADPH-dependent turnover of O2, uncoupled from cosubstrate hydroxylation, in a reconstituted phospholipid system containing the cytochrome P-450 isozyme purified from the liver microsomes of phenobarbital-induced rats results in autocatalytic inactivation of this P-450 isozyme. At NADPH concentrations of 1.0 mM, half-times for inactivation are 7 to 9 min and reflect processing of 800 molecules of NADPH/enzyme molecule before an inactivation event occurs. Addition of saturating amounts of N,N-dimethylaniline leads to a 3-fold increase of Vmax of NADPH utilization with 40% of these extra molecules providing electrons for the hydroxylation/N-demethylation sequence. About 2300 turnovers occur over the time period of inactivation, with about 425 product formaldehyde molecules being generated in this interval. This inactivation does not occur in intact microsomes from the livers of phenobarbital-treated rats; however, solubilization of the microsomes or addition of exogenous pure reductase renders the P-450 susceptible to the same autoinactivation.


Subject(s)
Cytochrome P-450 Enzyme System/metabolism , Isoenzymes/metabolism , Microsomes, Liver/enzymology , NADPH-Ferrihemoprotein Reductase/metabolism , Phenobarbital/pharmacology , Allylisopropylacetamide/pharmacology , Animals , Kinetics , Male , Microsomes, Liver/drug effects , Oxidation-Reduction , Rats
13.
Biochemistry ; 19(17): 3990-5, 1980 Aug 19.
Article in English | MEDLINE | ID: mdl-6250581

ABSTRACT

The kinetics of the inactivation of Bacillus cereus beta-lactamase I by 6 beta-bromopenicillanic acid are described. Loss of beta-lactamase activity is accompanied by a decrease in protein fluorescence, by the appearance of a protein-bound chromophore at 326 nm, and by loss of tritium from 6 alpha-[3H]-6 beta-bromopenicillanic acid. It is shown that all of the above changes probably have the same rate-determining step. The inactivation reaction is competitively inhibited by cephalosporin C, a competitive inhibitor of this enzyme, and by covalently bound clavulanic acid, suggesting that 6 beta-bromopenicillanic acid reacts directly with the beta-lactamase active site. It is proposed that this inhibitor reacts initially as a normal substrate and that the rate-determining step of the inactivation is acylation of the enzyme. A rapid irreversible inactivation reaction rather than normal hydrolysis of the acyl-enzyme then follows acylation; 6 beta-bromopenicillanic acid is thus a suicide substrate.


Subject(s)
Bacillus cereus/enzymology , Penicillanic Acid/pharmacology , beta-Lactamase Inhibitors , Hydrogen-Ion Concentration , Kinetics , Spectrometry, Fluorescence , Spectrophotometry, Ultraviolet , Tritium
14.
Proc Natl Acad Sci U S A ; 75(9): 4145-9, 1978 Sep.
Article in English | MEDLINE | ID: mdl-212736

ABSTRACT

6-beta-Bromopenicillanic acid, which arises from the epimerization of 6-alpha-bromopenicillanic acid in aqueous solution or from hydrogenation of 6,6-dibromopenicillanic acid, is a powerful, irreversible, active-site-directed inhibitor of several typical beta-lactamases (penicillinase; penicillin amido-beta-lactamhydrolase, EC 3.5.2.6); 6-alpha-bromopenicillanic acid, being completely inhibited at less than micromolar concentrations through what is probably a 1:1 interaction. The B. licheniformis exoenzyme is similarly susceptible, while the Staphylococcus aureus enzyme and the Escherichia coli (R factor) enzyme are less so; the B. cereus beta-lactamase II is not inhibited. Very high concentrations (greater than or equal to 0.1 M) of benzylpenicillin, a good substrate, are required to significantly reduce the rate of inhibition of B. cereus beta-lactamase I by 6-beta-bromopenicillanic acid.


Subject(s)
Penicillanic Acid/pharmacology , beta-Lactamase Inhibitors , Bacteria/enzymology , Kinetics , Magnetic Resonance Spectroscopy , Structure-Activity Relationship
16.
J Bacteriol ; 92(2): 446-54, 1966 Aug.
Article in English | MEDLINE | ID: mdl-16562134

ABSTRACT

Coggin, Joseph H. (University of Chicago, Chicago, Ill.), Muriel Loosemore, and William R. Martin. Metabolism of 6-mercaptopurine by resistant Escherichia coli cells. J. Bacteriol. 92:446-454. 1966.-6-Mercaptopurine (MP) utilization as a source of purine in MP-sensitive and -resistant cultures of Escherichia coli was investigated. The label of MP-8-C(14) appeared in adenine and guanine of ribonucleic acid and deoxyribonucleic acid in sensitive and resistant cultures. Studies using MP-S(35) further demonstrated that the MP moiety was degraded, as shown by a rapid decrease in radioactivity from cells upon exposure to MP for 20 min. Enzymatic analysis showed that MP was converted to 6-mercaptopurine ribonucleotide (MPRP) by extracts derived from both sensitive and resistant cells. Resistant cell preparations, however, degraded MPRP to inosine monophosphate (IMP) rapidly when compared with analogue degradation by sensitive cells. Inosineguanosine-5'-phosphate pyrophosphorylase from resistant cells did not catalyze the synthesis of IMP from hypoxanthine when the cells were cultured in the presence of MP, but these enzyme preparations actively converted guanine to guanosine monophosphate (GMP). Pyrophosphorylase derived from resistant cells cultured in medium without MP catalyzed the conversion of hypoxanthine to IMP and also guanine to GMP. These observations suggest that inosine-guanosine-5'-phosphate pyrophosphorylase is composed of two distinct enzymes. The mode of resistance to MP in E. coli is related to an enhancement of the enzymatic degradation of MPRP to the pivotal purine intermediate, IMP.

SELECTION OF CITATIONS
SEARCH DETAIL
...