Showing papers by "Michael Gleeson published in 2008"

Salivary IgA as a risk factor for upper respiratory infections in elite professional athletes.

Abstract: The relationship between physiological and psychological stress and immune function is widely recognized; however, there is little evidence to confirm a direct link between depressed immune function and incidence of illness in athletes.Purpose:To examine the relationship between salivary imm

The effect on immunity of long-term intensive training in elite swimmers.

Abstract: The impact of long-term training on systemic and mucosal immunity was assessed prospectively in a cohort of elite swimmers over a 7-month training season in preparation for national championships The results indicated significant suppression (P < 005) of serum IgA, IgG and IgM and salivary IgA concentration in athletes associated with long-term training at an intensive level There was also a trend towards lower IgG2 subclass levels in serum in athletes compared with controls (P = 007) There were no significant changes in numbers or percentages of B or T cell subsets, but there was a significant fall in natural killer (NK) cell numbers and percentages in athletes over the training season (P < 005) After individual training sessions there was a significant decrease in salivary IgA levels for athletes compared with controls (P = 0002) In athletes there was a downward trend in salivary IgA levels over the 7-month training period in both the pre-exercise (P = 006) and post-exercise samples (P = 004) There were no significant trends in salivary IgG levels over the study period in either athletes or controls The only significant change in salivary IgM levels was an increase in detection rate in the pre-competition phase in athletes (P = 003) The study suggests that training of elite athletes at an intensive level over both short- and long-time frames suppresses both systemic and mucosal immunity Protracted immune suppression linked with prolonged training may determine susceptibility to infection, particularly at times of major competitions

Effects of exercise intensity on salivary antimicrobial proteins and markers of stress in active men.

Abstract: In the present study, we assessed the effects of exercise intensity on salivary immunoglobulin A (s-IgA) and salivary lysozyme (s-Lys) and examined how these responses were associated with salivary markers of adrenal activation. Using a randomized design, 10 healthy active men participated in three experimental cycling trials: 50% maximal oxygen uptake (VO2max), 75%VO2max, and an incremental test to exhaustion. The durations of the trials were the same as for a preliminary incremental test to exhaustion (22.3 min, sx = 0.8). Timed, unstimulated saliva samples were collected before exercise, immediately after exercise, and 1 h after exercise. In the incremental exhaustion trial, the secretion rates of both s-IgA and s-Lys were increased. An increase in s-Lys secretion rate was also observed at 75%VO2max. No significant changes in saliva flow rate were observed in any trial. Cycling at 75%VOmax and to exhaustion increased the secretion of alpha-amylase and chromogranin A immediately after exercise; higher cortisol values at 75%VO2max and in the incremental exhaustion trial compared with 50%VO2max were observed 1 h immediately after exercise only. These findings suggest that short-duration, high-intensity exercise increases the secretion rate of s-IgA and s-Lys despite no change in the saliva flow rate. These effects appear to be associated with changes in sympathetic activity and not the hypothalamic - pituitary - adrenal axis.

Caffeine improves physical and cognitive performance during exhaustive exercise

Abstract: Caffeine is thought to act as a central stimulant and to have effects on physical, cognitive, and psychomotor functioning. Purpose: To examine the effects of ingesting a performance bar, containing caffeine, before and during cycling exercise on physical and cognitive performance. Methods: Twenty-four well-trained cyclists consumed the products [a performance bar containing 45 g of carbohydrate and 100 mg of caffeine (CAF), an isocaloric noncaffeine performance bar (CHO), or 300 mL of placebo beverage (BEV)] immediately before performing a 2.5-h exercise at 60% V˙ O2max followed by a time to exhaustion trial (T2EX) at 75% V˙ O2max. Additional products were taken after 55 and 115 min of exercise. Cognitive function measures (computerized Stroop and Rapid Visual Information Processing tests) were performed before exercise and while cycling after 70 and 140 min of exercise and again 5 min after completing the T2EX ride. Results: Participants were significantly faster after CAF when compared with CHO on both the computerized complex information processing tests, particularly after 140 min and after the T2EX ride (P G 0.001). On the BEV trial, performance was significantly slower than after both other treatments (P G 0.0001). There were no speed–accuracy tradeoffs (P 9 0.10). T2EX was longer after CAF consumption compared with both CHO and BEV trials (P G 0.05), and T2EX was longer after CHO than after BEV (P G 0.05). No differences were found in the ratings of perceived exertion, mean heart rate, and relative exercise intensity (%V˙ O2max; P 9 0.05). Conclusion: Caffeine in a performance bar can significantly improve endurance performance and complex cognitive ability during and after exercise. These effects may be salient for sports performance in which concentration plays a major role.

Dosing and Efficacy of Glutamine Supplementation in Human Exercise and Sport Training

Abstract: Some athletes can have high intakes of l-glutamine because of their high energy and protein intakes and also because they consume protein supplements, protein hydrolysates, and free amino acids. Prolonged exercise and periods of heavy training are associated with a decrease in the plasma glutamine concentration and this has been suggested to be a potential cause of the exercise-induced immune impairment and increased susceptibility to infection in athletes. However, several recent glutamine feeding intervention studies indicate that although the plasma glutamine concentration can be kept constant during and after prolonged strenuous exercise, the glutamine supplementation does not prevent the postexercise changes in several aspects of immune function. Although glutamine is essential for lymphocyte proliferation, the plasma glutamine concentration does not fall sufficiently low after exercise to compromise the rate of proliferation. Acute intakes of glutamine of approximately 20-30 g seem to be without ill effect in healthy adult humans and no harm was reported in 1 study in which athletes consumed 28 g glutamine every day for 14 d. Doses of up to 0.65 g/kg body mass of glutamine (in solution or as a suspension) have been reported to be tolerated by patients and did not result in abnormal plasma ammonia levels. However, the suggested reasons for taking glutamine supplements (support for immune system, increased glycogen synthesis, anticatabolic effect) have received little support from well-controlled scientific studies in healthy, well-nourished humans.

Scott-Brown's otorhinolaryngology, head and neck surgery

Abstract: SECTION I: CELL BIOLOGY and ITS APPLICATION (Editor Nick Jones) Molecular biology Genetics Gene therapy Mechanism of anti-cancer drugs Radiotherapy and radio-sensitizers Apoptosis and cell death SECTION II: WOUND HEALING (Editor: Nick Jones) Soft and hard tissue repair Skin flap physiology Biomaterials and their application in ORL SECTION III: IMMUNOLOGY (Editor Nick Jones) Defence mechanisms Allergy: basic mechanisms and tests Evaluation of the immune system Immuno-deficiencies Rheumatological disorders in ORL SECTION IV: MICROBIOLOGY (Editor Nick Jones) Micro-organisms Viruses and antiviral agents Fungi Antimicrobial therapy HIV and AIDS SECTION V: HAEMATOLOGY (Editor Nick Jones) Constituents of blood and blood groups and alternatives to blood transfusion Haemato-oncology Disorders of coagulation and their management SECTION VI: ENDOCRINOLOGY (Editor Nick Jones) The pituitary: anatomy and physiology The pituitary: function tests and imaging The thyroid: anatomy and physiology The thyroid: function tests and imaging The thyroid: non-malignant disease The parathyroid glands: anatomy and physiology The parathyroid glands: function tests and imaging Parathyroid dysfunction: medical and surgical therapy ENT manifestations of endocrine disease SECTION VII: THERAPEUTICS AND PHARMACOKINETICS (Editor Martin Burton) Drug administration and therapeutic monitoring Drug therapy in otology Drug therapy in rhinology Drug therapy in laryngology and head and neck surgery Corticosteroids - systemic and topical SECTION VIII: PERIOPERATIVE MANAGEMENT (Editor Martin Burton) Preparation of the patient for surgery Assessment of the difficult airway Paediatric anaesthesia Anaesthesia for adults Adult intensive and high-dependency care Paediatric intensive care SECTION IX: PAEDIATRIC OTOLARYNGOLOGY (Editor Ray Clarke) Introduction Embryology of the head and neck Genetics of deafness and genetic counselling Speech and language development The paediatric consultation and inpatient care Classification of hearing loss Non-infective conductive hearing loss in children Otitis media with effusion Acute suppurative otitis media Chronic otitis media in childhood Hearing tests Screening and surveillance for hearing loss in pre-school children Management congenital deformities of the external and middle ear Management of the hearing-impaired child Indications and contra-indications for cochlear implantation in children Facial paralysis in childhood The genetics of craniofacial anomalies Cleft palate Nasal obstruction in children Paediatric rhinosinusitis Foreign bodies in the ears, nose and airways Epistaxis in children Tonsils Sleep apnoea in childhood Introduction to airway obstruction Congenital disorders of the larynx, trachea and bronchi Laryngeal stenosis Voice disorders in children Acute laryngeal infections Recurrent respiratory papillomatosis Tracheostomy and care at home Diseases of oesophagus, swallowing disorders and caustic ingestion Branchial cleft disorders, thyroglossal cysts, fistulas, cystic hygroma ENT input for the child with multiple handicaps Salivary gland problems in childhood Tumours of the head and neck in childhood Cervico-facial infections in childhood Medicolegal negligence in paediatric ORL SECTION X: THE EAR, HEARING and BALANCE (Editors George Browning and Linda Luxon) Anatomy of the temporal bone, middle ear and Eustachian tube Form and ultrastructure of the cochlea and its central connections Physics of sound Physiology of hearing The perception of sound Psychoacoustic audiometry Physiological and evoked measurement of hearing Epidemiology of hearing loss in adults Clinical examination of the ears and hearing Conditions of pinna and external auditory canal Perichondritis Other pinna conditions Otitis externa Malignant otitis externa Benign necrotising otits externa Granular myringitis Bullous myringitis Acquired atresia Exostosis Furunculosis Keratosis obturans Acute otitis media in adults Otitis media with effusion in adults Chronic otitis media Definition Pathology Diagnosis Aetiology and epidemiology Healed otitis media Inactive mucosal chronic otitis media Active mucosal chronic otitis media Retractions Cholesteatoma Tuberculosis of the temporal bone Otosclerosis Definition including pathology Diagnosis Aetiology and epidemiology Outcomes Management options Effect of management on outcomes Paget's disease Sensori-neural hearing loss - retrocochlear Trauma to the ear Pinna Foreign bodies in the external auditory canal Tympanic membrane and middle ear trauma Temporal bone trauma Barotrauma Otalgia Age-related sensorineural hearing impairment Definition including pathology Aetiology and epidemiology Natural history Diagnosis Management Noise trauma Definition including pathology Aetiopathology Natural history Diagnosis Prevention and Management Other progressive sensorineural hearing impairments Genetic General disease Ototoxicity Idiopathic sudden sensorineural hearing impairment Tinnitus, paracusis and dysacusis Central auditory dysfunction Hearing aids Cochlear implants Accessory devices Middle ear implants Prevention of hearing loss - social consequences Prevention of hearing loss - scientific principles Anatomy and ultrastructure of the labyrinth and its central connections Physiology of equilibrium Evaluation of balance Pathology of the vestibular system Vertigo - clinical syndromes Vertigo - clinical management and rehabilitation Diseases of the temporal bone Disorders of the facial nerve Medical negligence in otology SECTION XI: THE NOSE and PARANASAL SINUSES (Editor Valerie Lund) Anatomy of the nose and paranasal sinuses