Biomedical subjects

Peter Hamer

Publications and source records attributed to Peter Hamer.

8 recordsLinked to original sources

PubMed2006

Serum epidermal growth factor receptor/HER-2 predicts poor survival in patients with metastatic breast cancer.

BACKGROUND: Epidermal growth factor receptor (EGFR, HER-1, and erbB1) is overexpressed in primary breast cancer and had been identified as a poor prognostic factor. METHODS: Pretreatment serum EGFR levels were quantified by using an enzyme-linked immunoadsorbent assay in a Phase III first-line trial of letrozole and tamoxifen and were correlated with patient outcomes. RESULTS: Serum EGFR levels in a control group of 117 healthy, postmenopausal women measured 64.1 +/- 13.3 ng/mL (mean +/- standard deviation). Using a cutoff EGFR level of 44.1 ng/mL from the control group (5% nonparametric method), 53 of 535 patients (10%) had decreased serum levels of EGFR. Patients with decreased serum EGFR had no significant difference in objective response rate (ORR), clinical benefit rate (CBR), time to progression (TTP), or time to treatment failure (TTF); however, they did have significantly reduced survival compared with patients who had normal serum EGFR levels (median survival, 23.3 months vs. 30.9 months; P = .007). A combined analysis of pretreatment serum EGFR and HER-2 yielded no additional predictive information for ORR, CBR, TTP, or TTF compared to serum HER-2 alone. However, in the current analysis, a subgroup of patients who had decreased serum EGFR and normal serum HER-2 was identified (n = 39 of 535 patients; 7.3%) that had significantly reduced survival compared with patients who had normal serum levels of both EGFR and HER-2 (median survival, 23.5 months vs. 37.1 months; P = .005). In multivariate analysis, a decreased serum EGFR level remained a significant independent prognostic factor for decreased survival (hazards ratio, 1.58; P = .007). CONCLUSIONS: In patients who had metastatic breast cancer, decreased serum EGFR/normal serum HER-2 predicted shorter survival compared with patients who had normal levels of serum EGFR/HER-2. This patient subgroup deserves further study to assess their response to and selection for anti-EGFR-directed therapies.

Adult↗

PubMed2006

Reproducibility of a 6-s maximal cycling sprint test.

The purpose of this study was to examine the reproducibility in measures of power output during a 6-s, maximal cycling sprint test. Eleven healthy, moderately-trained males (mean+/-S.D.; age=19+/-1 year; height=181.5+/-6.2 cm; mass=76.9+/-9.5 kg; peak oxygen uptake 54.9+/-6.1 mL kg(-1)min(-1)) performed a 6-s standing sprint on a front-access cycle ergometer on four separate occasions. Peak power output (PPO) was significantly higher (4.9%; P<0.05) in trial 2 compared with trial 1, whereas there were no significant differences between trials 2, 3 and 4. Similarly, the mean power output (MPO) for trial 2 was higher (5.8%; P<0.05) than in trial 1, but there were no difference across trials 2, 3 and 4. The within-subject coefficient of variation (CV) from trials 2 to 4 was 2.8 and 2.9% for PPO and MPO, respectively, while the CV calculated using data from the third and fourth trial was lower: 1.8 and 2.5% for PPO and MPO, respectively. The results of the study showed that reliable power outputs can be obtained after one familiarization session in subjects unfamiliar with maximal cycling sprint exercise. However, the inclusion of an extra familiarization session ensured more stable power outputs. Therefore, two trials should allow adequate familiarization with the maximal 6-s cycling test.

Adolescent↗

PubMed2006

Activity profile of world-class professional surfers during competition: a case study.

The activity profile of men's competitive surfing was investigated during an international contest. Forty-two male surfers were filmed during 42 elimination heats. Surfers' activities were classified into 1 of 4 distinct categories (paddling, wave riding, stationary, and miscellaneous). The surfers were paddling and stationary 51% (25-70%) and 42% (23-72%) of the total time, respectively. Wave riding accounted for 4% (2-7%) of the total time, whereas miscellaneous activity accounted for the remaining 2% (0.1-6%) of the total time. The frequency (average number of motions in a heat) of each activity was 26 for paddling (15-37); 17 for stationary (10-26); 5 for wave riding (2-8); and 6 for miscellaneous activity (1-13). The mean duration lengths of the activities were 30.1 seconds (1-286 seconds), 37.7 seconds (1-413 seconds), 11.6 seconds (1-44 seconds), and 5 seconds (1- 31 seconds) for paddling, stationary, wave riding, and miscellaneous activities, respectively. Most of the paddling bouts ( approximately 60%) were performed at time intervals of between 1 and 20 seconds. Approximately 50% (50.9%) of the rest intervals were between 1 and 20 seconds in duration. The results showed that surfing is an intermittent activity characterized by a large variability and random distribution of each parameter analyzed. This information can be used to assist in the development of fitness training programs and physiological testing for competitive surfers.

Competitive Behavior↗

PubMed2005

Serum HER-2/neu conversion to positive at the time of disease progression in patients with breast carcinoma on hormone therapy.

BACKGROUND: Prolonged exposure of breast carcinoma cells in vitro to tamoxifen results in tamoxifen resistance. Tamoxifen-resistant cells express increased HER-2/neu mRNA and protein. The objective of this study was to determine whether patients with metastatic or locally advanced breast carcinoma who have negative serum HER-2/neu status at the initiation of first-line hormone therapy with letrozole or tamoxifen convert to positive serum HER-2/neu status at the time of disease progression and to determine whether serum HER-2/neu conversion to positive status is associated with response to therapy and overall survival. METHODS: Serum samples were obtained at baseline and at the time of disease progression from 240 patients who initially had negative serum HER-2/neu status (< 15 ng/mL). A manual microtiter, enzyme-linked immunosorbent assay that was specific for the extracellular domain of the HER-2/neu (c-erbB-2) oncoprotein product was used to quantitate serum levels. RESULTS: Among 240 patients, 61 patients (26%) converted from serum HER-2/neu negative to positive (> 15 ng/mL) at the time of disease progression. Thirty-two of 129 patients (25%) who were treated with tamoxifen and 29 of 111 patients (26%) who were treated with letrozole became converted to positive serum HER-2/neu status at the time of disease progression. The response rate and the time to disease progression on first-line hormone therapy were not affected by serum HER-2/neu conversion. The survival of patients who converted to positive serum HER-2/neu status was significantly shorter compared with the survival of patients who remained negative for serum HER-2/neu. A multivariate analysis revealed that conversion to positive serum HER-2/neu status was an independent prognostic variable for survival. CONCLUSIONS: Conversion to positive serum HER-2/neu status occurred in approximately 25% of patients who received first-line hormone therapy. Conversion to serum HER-2/neu-positive status occurred with equal frequency in antiestrogen and aromatase-inhibitor therapy. The current results showed that serum conversion to HER-2/neu-positive status was an independent risk factor for decreased survival in patients with breast carcinoma.

Antineoplastic Agents, Hormonal↗

PubMed2003

The difficult patient in private practice physiotherapy: a qualitative study.

This qualitative study utilised the nominal group technique to identify a typology of the difficult patient in private practice physiotherapy and to determine strategies physiotherapists use, and would like to improve, when dealing with such patients. The two areas physiotherapists found most difficult to manage were behavioural problems of patients and patient expectations. Few differences were evident regarding ranking of difficult patient attributes between the experienced (n = 19) and less experienced (n = 18) physiotherapists except for the categories of pain and diagnosed psychological problems. While less experienced physiotherapists ranked the pain category highly, experienced physiotherapists did not identify this category. Further, more experienced physiotherapists specifically distinguished between patients with diagnosed psychological problems and patients with psychosocial concerns, while less experienced physiotherapists did not, and placed both these issues into one category. To assist in their interaction with difficult patients, physiotherapists (n = 37) identified that communication skills and behaviour modification techniques were strategies that they would like to learn more about. The results of this qualitative study contribute to the evolving literature relating to physiotherapist-patient interactions and form a useful basis for educational programs directed at improving the therapeutic relationship in private practice physiotherapy.

Attitude of Health Personnel↗

PubMed2003

The physiotherapy experience in private practice: the patients' perspective.

The aim of this study was to identify the qualities of a "good" physiotherapist and to ascertain the characteristics of good and bad experiences in private practice physiotherapy from the patients' perspective. The nominal group technique was implemented with separate groups of patients (n = 26) and revealed that communication ability, professional behaviour and organisational ability, and characteristics of the service provided were the main qualities of a "good" physiotherapist. In particular, communication ability of the physiotherapist was ranked first or second in importance by all groups of patients. Good experiences in physiotherapy were most often attributed to effective communication by the physiotherapist, while bad experiences most often related to dissatisfaction with the service followed by poor physiotherapist communication. Based on the findings from this study, we suggest physiotherapists should actively seek to involve patients in their management. To do this effectively, physiotherapists would benefit from further training in communication skills to ensure that they can successfully adopt a patient-centred approach and to optimise the physiotherapist-patient interaction in private practice physiotherapy.

Adult↗

PubMed2002

Sports injury experiences from the Western Australian Sports Injury Cohort Study.

OBJECTIVE: The Western Australian Sports Injury Study is the first prospective cohort study of sports injuries sustained during community-level sports participation in Australia. METHODS: The players were nonprofessional/non-elite participants of hockey, Australian football, basketball and netball from metropolitan Perth. Players completed a baseline questionnaire relating to their sports injury history, training practices, protective equipment use, demographic profile, general health and lifestyle factors. Sports participation and injury experiences were monitored by monthly telephone surveys over two consecutive five-month winter sporting seasons during 1997 and 1998. RESULTS: Of the 1,512 players recruited into the initial cohort, 966 (i.e. 64%) responded to at least 700% of the callback surveys over the two-year follow-up. Across all sports, the injury incidence rate was 16.1 injuries/ 1,000 exposure hours (both games and training). Injury rates were highest in Australian football and lowest in netball. Lower limb injuries were twice as common as those to the upper limb (67% vs. 31%). Three-quarters of injured players sought treatment from a health care practitioner. CONCLUSIONS AND IMPLICATIONS: This is the first longitudinal study of injuries to community-based sports participants in Australia. Compared with elite sports participants, the risk of injury is relatively low. The results provide valuable direction for the design and conduct of further aetiological studies.

Adolescent↗

PubMed1997

The psychophysical and heart rate relationship between treadmill and deep-water running.

The relationship between ratings of perceived exertion and heart rate attained during submaximal running tests on a treadmill and during deep-water running was investigated in 12 male subjects. Heart rate and rating of perceived exertion scores analysed by analysis of covariance tested the equality of adjusted means and parallelism of the slope of this relationship. No significant difference existed between the slopes of the regression equations established for treadmill running and deep-water running. A paired t-test performed across the adjusted group mean heart rates revealed a significant difference between the two conditions. While the slope of the heart rate to rating of perceived exertion regression equations remained similar, the mean heart rate was 17 beats per minute lower in the deep-water running condition than during the treadmill run.

Journal Article↗