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Biomedical subjects

W R Payne

Publications and source records attributed to W R Payne.

17 recordsLinked to original sources
PubMed2001

A prospective study of injuries in basketball: a total profile and comparison by gender and standard of competition.

The study aimed to determine prospectively a basketball injury profile, including severity of injury, and to compare the injury profile by gender and standard of competition. Trained observers viewed basketball games, noting the occurrence of injuries, and confirmed injuries by questioning all players on site after the game. Injured players completed a questionnaire and the progress of their injury was monitored by telephone interview. A total of 10,393 basketball participations were observed. An overall injury rate was documented of 18.3 per 1,000 participations (24.7 per 1,000 playing hours), and was comparable by gender and standard of competition. Serious injuries (missing one or more weeks of play) occurred at a rate of 2.89/1,000 participations; with the ankle joint the most common serious injury (1.25/1,000 participations), followed by the calf/anterior leg (0.48/1,000 participations) and knee joint (0.29/1,000 participations). The severity of the injury was significantly associated with the body region injured, with more serious injuries incurred to the lower limb than other body regions (p <.05). The severity of the injury incurred was not related to the standard of competition, gender, age, height, number of games played per week, amount of training undertaken, type of injury, or the mechanism of injury (p> .05).

Adult↗
PubMed2001

Ankle injuries in basketball: injury rate and risk factors.

OBJECTIVES: To determine the rate of ankle injury and examine risk factors of ankle injuries in mainly recreational basketball players. METHODS: Injury observers sat courtside to determine the occurrence of ankle injuries in basketball. Ankle injured players and a group of non-injured basketball players completed a questionnaire. RESULTS: A total of 10 393 basketball participations were observed and 40 ankle injuries documented. A group of non-injured players formed the control group (n = 360). The rate of ankle injury was 3.85 per 1000 participations, with almost half (45.9%) missing one week or more of competition and the most common mechanism being landing (45%). Over half (56.8%) of the ankle injured basketball players did not seek professional treatment. Three risk factors for ankle injury were identified: (1) players with a history of ankle injury were almost five times more likely to sustain an ankle injury (odds ratio (OR) 4.94, 95% confidence interval (CI) 1.95 to 12.48); (2) players wearing shoes with air cells in the heel were 4.3 times more likely to injure an ankle than those wearing shoes without air cells (OR 4.34, 95% CI 1.51 to 12.40); (3) players who did not stretch before the game were 2.6 times more likely to injure an ankle than players who did (OR 2.62, 95% CI 1.01 to 6.34). There was also a trend toward ankle tape decreasing the risk of ankle injury in players with a history of ankle injury (p = 0.06). CONCLUSIONS: Ankle injuries occurred at a rate of 3.85 per 1000 participations. The three identified risk factors, and landing, should all be considered when preventive strategies for ankle injuries in basketball are being formulated.

Adult↗
PubMed2000

Compressive and shear force generated in the lumbar spine of female rowers.

Rowers have and accrue greater lumbar spine bone mineral density (BMD) associated with mechanical loading produced during rowing. The aim of this study was to estimate the mechanical loading generated at the lumbar spine (LS) that is apparently providing an osteogenic benefit. The cohort comprised 14 female rowers (average age: 19.7yrs; height: 170.9 cm, weight: 59.5 kg) and 14 female matched controls (average age: 20.9 m yrs; height: 167.5 cm; weight: 58.1 kg). BMD was assessed using the Hologic QDR 2000+ bone densitometer, indicating higher lumbar spine BMD in the rowers compared to the control subjects (1,069 +/- 0.1 vs. 1,027 +/- 0.1 g/cm2). No significant difference existed for BMD at any other site. All rowers performed a six-minute simulated race on a Concept II rowing ergometer. Mechanical loading generated at the lumbar spine during this task was assessed using a two-dimensional model of the spine, enabling the calculation of the compressive and shear forces at L4/L5. The shear force was the joint reaction force perpendicular to the spine at the L4/L5 joint. Peak compressive and shear force at the lumbar spine of the rowers were 2,694 +/- 609 (N) and 660 +/- 117 (N), respectively. Peak compressive force at the LS relative to body weight was 4.6 times body weight. The literature would suggest that forces of this magnitude, generated at the LS during maximal rowing, may be contributing to the site specific higher LS BMD found in the rowers.

Adolescent↗
PubMed1999

The impact of intense training on endogenous estrogen and progesterone concentrations and bone mineral acquisition in adolescent rowers.

The effect of 18 months of training on the ovarian hormone concentrations and bone mineral density (BMD) accrual was assessed longitudinally in 14 adolescent rowers and 10 matched controls, aged 14-15 years. Ovarian hormone levels were assessed by urinary estrone glucuronide (E(1)G) and pregnanediol glucuronide (PdG) excretion rates, classifying the menstrual cycles as ovulatory or anovulatory. Total body (TB), total proximal femur (PF), femoral neck (FN) and lumbar spine (LS) (L2-4) bone mass were measured at baseline and 18 months using dual-energy X-ray densitometry. Results were expressed as bone mineral content (BMC), BMD and bone mineral apparent density (BMAD). Five rowers had anovulatory menstrual cycles compared with zero prevalence for the control subjects. Baseline TB BMD was significantly higher in the ovulatory rowers, with PF BMD, FN BMD and LS BMD similar for all groups. At completion, the LS bone accrual of the ovulatory rowers was significantly greater (BMC 8.1%, BMD 6.2%, BMAD 6.2%) than that of the anovulatory rowers (BMC 1.1%, BMD 3.9%, BMAD 1.6%) and ovulatory controls (BMC 0.5%, BMD 1.1%, BMAD 1.1%). No difference in TB, PF or FN bone accrual was observed among groups. This study demonstrated an osteogenic response to mechanical loading, with the rowers accruing greater bone mass than the controls at the lumbar spine. However, the exercise-induced osteogenic benefits were less when rowing training was associated with low estrogen and progesterone metabolite excretion.

Adolescent↗
PubMed1999

A field study to compare performance of stainless steel research monitoring wells with existing on-farm drinking water wells in measuring pesticide and nitrate concentrations.

Existing drinking water wells are widely used for the collection of ground water samples to evaluate chemical contamination. A well comparison study was conducted to compare pesticide and nitrate-N data from specially designed stainless steel research monitoring wells with data from nearby existing on-farm drinking water wells. Results could help to determine whether adequate information concerning ground water contamination can be obtained from existing drinking water wells for use in making pollutant control decisions. The study was conducted during 1993-1994 in the Little Coharie Watershed, a 158 square mile area located in the coastal plain of eastern North Carolina. Statistical analysis indicated that research monitoring wells provided a greater probability of detecting pesticides in ground water than existing on-farm wells. Atrazine was the most frequently detected pesticide found in all wells, followed in order by fluometuron, carbofuran, metolachlor, alachlor, carbaryl, butylate, chlorothalonil, linuron and simazine. Ninety-seven percent of all wells had observed concentrations of nitrate-N, ranging from 0.1 to 30.1 mg/L. There was not a significant difference between research wells and existing wells for monitoring nitrate-N. Based on results of this study, existing drinking water wells can be used for monitoring nitrate; however, specialized stainless steel monitoring wells should be used for monitoring pesticides in ground water.

Databases, Factual↗
PubMed1999

Prospective decrease in progesterone concentrations in female lightweight rowers during the competition season compared with the off season: a controlled study examining weight loss and intensive exercise.

The purpose of this study was to monitor ovarian hormone function response to intense exercise and body weight changes in female athletes. Ovarian hormone function was evaluated in 12 female lightweight rowers and 10 age-height-weight matched sedentary controls. Ovarian hormone function was assessed during consecutive competition season and off season, by measurement of peak and average alternative day overnight urinary oestrone glucuronide (E1G) and pregnanediol glucuronide (PdG) excretion. Competition season was associated with a 5.8 kg (9.3%) body weight loss in the lightweight rowers. Significantly lower competition season peak and average urinary excretion of PdG were found in the lightweight rowers compared with the controls. Lower competition season peak and average urinary excretion of E1G were also found in the lightweight rowers compared with the controls, but the difference did not reach significance. The number of rowing training hours was a significant determinant of peak PdG excretion in the rowers (R2 = 0.40; p<0.02). The seasonal suppression of PdG excretion was associated with degree of weight loss (R2 = 0.46; p<0.01). The competition related decrease in E1G and PdG excretion for the lightweight rowers was predominantly restored during the off season when exercise intensity and duration were decreased and body weight increased. These results showed a significant (p<0.05) reduction in progesterone metabolite excretion and a non-significant decrease in oestrone metabolite excretion associated with intensive competition season training loads and body weight reduction in female lightweight rowers.

Adolescent↗
PubMed1996

Seasonal variations in the body composition of lightweight rowers.

OBJECTIVE: To monitor the seasonal body composition alterations in 18 lightweight rowers (six females, 12 males) across a rowing season incorporating preseason, early competition, competition, and postseason. METHODS: Subject age was 23.1 (SD 4.5) years, height 170.8 (5.6) cm (female, 23.5 (3.5) years, 180.5 (2.7) cm (male). Body weight, fat mass, and fat-free mass (FFM) were assessed using dual energy x ray absorptiometry (DXA-L Lunar) and skinfold techniques. Weight control techniques were documented before major regattas by a questionnaire. RESULTS: Female body weight was reduced from 61.3 (2.9) to 57.0 (1.1) kg (5.9%), while male body weight was reduced from 75.6 (3.1) to 69.8 (1.6) kg (7.8%) preseason to competition season respectively. These body weight reductions were mirrored by a significant reduction in fat mass as indicated by the sum of skinfolds [female seven sites: 80.9 (8.1) to 68.2 (11.8) mm; male eight sites: 54.2 (8.7) to 41.8 (4.8) mm], percentage body fat [female 22.1 (1.0) to 19.7 (2.4)%; male 10.0 (0.9) to 7.8 (0.8)%], and total fat [female 12.5 (5.2) to 10.9 (1.4) kg; male 7.3 (1.9) to 5.6 (1.8) kg] (DXA). In contrast, no changes were observed in FFM despite a season of intensive rowing training. Seasonal body weight control was achieved through reduced total energy and dietary fat intakes. Acute body weight reductions were achieved by exercise in 73.3% of participants, food restriction in 71.4%, and fluid restrictions in 62.9%. CONCLUSIONS: Seasonal body weight alterations in lightweight rowers are in response to a significant reduction in fat mass. However, the weight restrictions appear to be limiting an increase in FFM which could be beneficial to rowing performance.

Adipose Tissue↗
PubMed1996

A comparison of the injuries sustained by female basketball and netball players.

A prospective and reliable method of injury surveillance was implemented to document a comprehensive injury profile in female basketball and netball. The study further aimed to compare the injury profiles of the two sports. Trained observers viewed basketball and netball games, noting the occurrence of injuries. Injuries were confirmed by questioning all players on site after the game. Injured players completed a questionnaire and the progress of their injury was monitored by telephone interview. A total of 16,162 player participations were observed; 6,972 for basketball and 9,190 for netball. Comparable injury rates were observed for female basketball and netball players; 18.22 and 17.30 injuries per 1,000 participations, respectively. The ankle, hand and knee were the body parts injured most frequently in both sports, whilst head and neck injuries were prevalent in basketball only. Netball players sustained severe injuries at a rate 3.3 times that of female basketball players. The major and severe injuries occurred at an average of one injury in 625 games in female basketball and one in 250 games in netball. The ankle, knee and calf/shin were the body parts most frequently involved in the more serious injuries.

Athletic Injuries↗
PubMed1994

Thermoregulatory response to wearing encapsulated protective clothing during simulated work in various thermal environments.

This investigation assessed the thermoregulatory impact of performing simulated tasks normally encountered during chemical accident clean-up while wearing chemical protection clothing under various representative thermal loads. A Drager 500 (D) suit was worn with a self-contained breathing apparatus (SCBA) external to the suit, while both a Trelleborg Trellchem Super Extra (T) and a James North MZ500 (J) suit required the SCBA to be worn inside the suit. The D suit was unventilated, while the T and S suits were ventilated with the subject's exhaled air. The T suit also was ventilated via a 2 L/min flow of air from the SCBA. Subjects were six firefighters. Each simulation lasted for 30 minutes and involved tasks such as drum rolling, drum carrying, walking, and hose dragging. The trials were conducted at 11.3, 17.1, and 23.8 degrees C WBGT. The overall mean peak heart rate was 128.1 +/- 2.80 breaths/min and was elicited while performing lifting tasks. Nonsignificant differences (p > 0.05) were observed for both the average heart rate and sweat rate. Mean skin temperature, mean body temperature, and temperature within the suit cavity were significantly higher when wearing the D suit compared to wearing T or J suits; differences between the T and J suits were nonsignificant. Suit type did not significantly affect rectal temperature, which also failed to exceed the American Council of Governmental Industrial Hygienists' (ACGIH) standard of 38.0 degrees C.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Rowing performance, fluid balance, and metabolic function following dehydration and rehydration.

Eight international class lightweight rowers were examined to determine the efficacy of rehydrating with water following 24 h of dehydration on body fluid balance, metabolic function, and rowing performance. The rowers performed a maximal rowing trial on a Gjessing rowing ergometer (4200 revs, 3-kg resistance) while euhydrated (ET) and following partial rehydration (RT). Body weight was reduced using exercise together with food and fluid restriction over 24 h and was followed by consumption of 1.5 l of water over 2 h. Body weight decreased 5.16 +/- 0.14% (P < 0.05) and plasma volume decreased 12.5 +/- 1.4% (P < 0.05) after dehydration. Rehydration restored plasma volume by 6.02 +/- 0.62%. Rowing trial time increased significantly from 7.02 +/- 0.17 min for the ET to 7.38 +/- 0.21 min for the RT (P < 0.05). The net plasma lactate accumulation decreased significantly from 8.77 +/- 0.31 mmol.l-1 for the ET to 6.77 +/- 0.24 mmol.l-1 for the RT (P < 0.05). Glycogen content (glycosyl units) of the vastus lateralis decreased by 203.6 +/- 18.6 mmol.kg-1 DW during the ET compared with 139.9 +/- 13.4 mmol.kg-1 DW during the RT (P < 0.05). These results demonstrate that the dehydration/rehydration protocol reduced maximal rowing performance due to lowered plasma volume and decreased muscle glycogen utilization.

Adult↗
PubMed1990

Ectoparasites of ring-necked pheasants in Nebraska.

In 1971, 1983 and 1984, ectoparasites were identified on 61 ring-necked pheasants (Phasianus colchicus) from Nebraska. Birds were collected throughout the state from 11 of 93 counties. Four species of chewing lice (Mallophaga) were collected: Lipeurus maculosus, Goniodes colchici, Lagopoecus colchicus and Amyrsidea megalosoma. One species of analgid mite, Megninia sp. was collected. Apparently, this species is new and undescribed. The four mallophagan species have not been reported from Nebraska.

Animals↗
PubMed1989

Urea production during prolonged swimming.

Male interscholastic swimmers (n = 8) completed a 4572 m training swim in in 62 +/- 1.1 min (means +/- S.E.) with terminal heart rate and blood lactate of 152 +/- 6 beats min-1 and 6.9 +/- 0.89 mM, respectively. Sweat rate (0.48 +/- 0.095 l. h-1) was lower than similar intensity cycling (1.5 +/- 0.13 l. h-1) or running (1.1 +/- 0.14 l. h-1). Post-swim serum urea N (11.6 +/- 0.71 mM) was elevated (P less than 0.05) vs pre-swim (4.6 +/- 0.39 mM). Post-swim urine volume (860 +/- 75 ml 24 h-1) was reduced (P less than 0.07) and resulted in an elevated (P less than 0.05), but delayed (24-84 h), post-exercise urea N excretion. Although the reduced urine and sweat production during the swim undoubtedly contributed to the elevated serum urea, there must be another explanation because together they could only account for 38% of the observed increase. On the basis of the magnitude of serum urea increase, it appears that the swim caused an increase in urea production (amino acid oxidation). The failure to observe larger increases in urinary urea during recovery indicates that either urea excretion following exercise continues for prolonged periods of time (greater than 48 h) or another significant mode of nitrogen excretion exists.

Adolescent↗
PubMed1985

Left ventricular function of the isolated, genetically obese rat's heart.

We sought to determine if left ventricular (LV) function of the heart from the adult, chronically obese animal is impaired. Hearts from 50 wk-old genetically obese female Zucker rats (624 +/- 13 g) and their lean littermate controls (275 +/- 5 g) were isolated during ether anesthesia, supported metabolically by retrograde aortic perfusion (6 ml/min, 35 degrees C) with physiological solution containing suspended canine erythrocytes (hematocrit, 20%), and the ventricles were paced at 180 beats/min. A distensible, fluid-filled balloon was placed in the LV, and pressure-volume (PV) relationships were obtained. The obese and lean end-diastolic PV curves were not different, and therefore the obese and lean LV chamber compliances were similar. Comparison of the systolic PV relationships demonstrated that the obese rat's heart had a greater pressure-generating capability, which probably was a reflection of its increased LV mass (0.96 +/- 0.03 vs. 0.72 +/- 0.02 g). The calculated average meridional (or circumferential) peak systolic wall stress in the LV of the obese rat's heart, however, was significantly reduced compared with control. This diminished ability to develop systolic stress from the same end-diastolic volumes suggests that the hypertrophied LV of the middle-aged obese rat's heart is dilated or that its contractility is depressed, or both.

Animals↗
PubMed1981

The persistence and disappearance by washoff and dryfall of methoxychlor from soybean foliage--a preliminary study.

The persistence and disappearance (washoff or dryfall) of methoxychlor [2,2-bis(p-methoxyphenyl)-1,1,1-trichloroethane] from mature soybean [Glycine max (L.) Merrill] foliage was investigated in a small field plot study under natural rainfall conditions in 1977 and 1978. Residue analyses were conducted using whole plant samples. Methoxychlor washoff rate was 8+/- 4% of the amount on plants (prior to rain) per centimeter of rainfall, regardless of time after application. Total seasonal washoff for 1978 accounted for 33.5% of the applied pesticide; however, 30.5% of the total loss was removed by washoff on the second day after application. Dryfall or dislodgeable residue accounted for less than 1% of the amount applied. The amount of dryfall was significantly greater in plots entered by workers than in those where entry was avoided. More than 19% of the applied methoxychlor was lost as a result of through-fall to the ground during application to the plots. Statistical analyses indicated that within-sample variation for mechanical chopping of plant samples was significantly smaller at the 5% level than for a hand chopping method. Results from this study will be useful in defining research objectives for the development of algorithms to describe the behavior of foliar-applied compounds. Such algorithms are necessary for estimating runoff losses of insecticides to water bodies.

Methoxychlor↗
PubMed1979

Effect of autoanalgesia on CNS enkephalin receptors.

Fear conditioning to foot shock (15 sec/day, 12 days) elicited autoanalgesia in 10 male (Sprague-Dawley) rats, while 17 non-shock control rats exhibited no analgesia as measured by the tail-flick assay. The binding of 3H-leu-enkephalin to synaptosomal preparations isolated from fear conditioned (experimental) and control animals was analyzed. At leu-enkephalin concentrations of 10(-9) M or less, both synaptosomal preparations demonstrated high affinity binding with dissociation constants on the order of 10(-10). Binding of leu-enkephalin could not be displaced by a hundred-fold excess of naloxone at leu-enkephalin concentrations less than 10(-9) M. However, the ability of naloxone to compete with leu-enkephalin for binding sites progressively increased at concentrations greater than 10(-9) M leu-enkephalin. At these ligand concentrations, the competition of naloxone for leu-enkephalin binding sites was more dramatic in the control than in the experimental animals. These data support the existence of two classes of receptors for leu-enkephalin, one of which is not blocked by opiate antagonists. Furthermore, changes in binding capacity associated with autoanalgesia produced by conditioned fear are consistent with the hypothesis of endogenous release of opiate-like peptides in response to stress.

Analgesia↗